[svn-r22422] Purpose: Add support for SWMR with v2 b-trees

Description:
Adds SWMR support to the v2 b-trees when used as a chunk index.  Because each
node keeps track of the total number of records reachable through each of its
children, nodes must be shadowed every time a descendent record is inserted or
removed.  This implementation prevents this from happening, however, if the node
has already been shadowed since the last time the v2 b-tree header was flushed.
Also modified SWMR test to include v2 b-trees.

Tested: jam, koala, ostrich (h5committest), durandal
  Note: There is a preexisting failure in the ph5diff (-v) test

29 files changed, 2814 insertions, 359 deletions

diff --git a/src/H5Abtree2.c b/src/H5Abtree2.c
index 5a15c20..afaab84 100644
--- a/src/H5Abtree2.c
+++ b/src/H5Abtree2.c
@@ -116,6 +116,8 @@ const H5B2_class_t H5A_BT2_NAME[1]={{  /* B-tree class information */
     H5A_dense_btree2_name_compare,     /* Record comparison callback */
     H5A_dense_btree2_name_encode,      /* Record encoding callback */
     H5A_dense_btree2_name_decode,      /* Record decoding callback */
+    NULL,                              /* Create flush dependency *//*!FIXME write me -NAF */
+    NULL,                              /* Update flush dependency *//*!FIXME write me -NAF */
     H5A_dense_btree2_name_debug,       /* Record debugging callback */
     NULL,                              /* Create debugging context */
     NULL                               /* Destroy debugging context */
@@ -132,6 +134,8 @@ const H5B2_class_t H5A_BT2_CORDER[1]={{ /* B-tree class information */
     H5A_dense_btree2_corder_compare,   /* Record comparison callback */
     H5A_dense_btree2_corder_encode,    /* Record encoding callback */
     H5A_dense_btree2_corder_decode,    /* Record decoding callback */
+    NULL,                              /* Create flush dependency *//*!FIXME write me -NAF */
+    NULL,                              /* Update flush dependency *//*!FIXME write me -NAF */
     H5A_dense_btree2_corder_debug,     /* Record debugging callback */
     NULL,                              /* Create debugging context */
     NULL                               /* Destroy debugging context */
diff --git a/src/H5Adense.c b/src/H5Adense.c
index 4c10255..3005749 100644
--- a/src/H5Adense.c
+++ b/src/H5Adense.c
@@ -126,6 +126,7 @@ typedef struct H5A_bt2_ud_rm_t {
     /* downward */
     H5A_bt2_ud_common_t common;         /* Common info for B-tree user data (must be first) */
     haddr_t corder_bt2_addr;            /* v2 B-tree address of creation order index */
+    void *parent;                       /* Flush dependency parent */
 } H5A_bt2_ud_rm_t;
 
 /*
@@ -140,6 +141,7 @@ typedef struct H5A_bt2_ud_rmbi_t {
     H5HF_t      *shared_fheap;          /* Fractal heap handle for shared messages */
     H5_index_t  idx_type;               /* Index type for operation */
     haddr_t     other_bt2_addr;         /* v2 B-tree address of "other" index */
+    void        *parent;                /* Flush dependency parent */
 } H5A_bt2_ud_rmbi_t;
 
 
@@ -183,7 +185,7 @@ typedef struct H5A_bt2_ud_rmbi_t {
  *-------------------------------------------------------------------------
  */
 herr_t
-H5A_dense_create(H5F_t *f, hid_t dxpl_id, H5O_ainfo_t *ainfo)
+H5A_dense_create(H5F_t *f, hid_t dxpl_id, H5O_ainfo_t *ainfo, void *parent)
 {
     H5HF_create_t fheap_cparam;         /* Fractal heap creation parameters */
     H5B2_create_t bt2_cparam;           /* v2 B-tree creation parameters */
@@ -246,7 +248,7 @@ HDfprintf(stderr, "%s: fheap_id_len = %Zu\n", FUNC, fheap_id_len);
             H5O_FHEAP_ID_LEN;           /* Fractal heap ID */
     bt2_cparam.split_percent = H5A_NAME_BT2_SPLIT_PERC;
     bt2_cparam.merge_percent = H5A_NAME_BT2_MERGE_PERC;
-    if(NULL == (bt2_name = H5B2_create(f, dxpl_id, &bt2_cparam, NULL)))
+    if(NULL == (bt2_name = H5B2_create(f, dxpl_id, &bt2_cparam, NULL, parent)))
         HGOTO_ERROR(H5E_ATTR, H5E_CANTINIT, FAIL, "unable to create v2 B-tree for name index")
 
     /* Retrieve the v2 B-tree's address in the file */
@@ -267,7 +269,7 @@ HDfprintf(stderr, "%s: ainfo->name_bt2_addr = %a\n", FUNC, ainfo->name_bt2_addr)
                 H5O_FHEAP_ID_LEN;       /* Fractal heap ID */
         bt2_cparam.split_percent = H5A_CORDER_BT2_SPLIT_PERC;
         bt2_cparam.merge_percent = H5A_CORDER_BT2_MERGE_PERC;
-        if(NULL == (bt2_corder = H5B2_create(f, dxpl_id, &bt2_cparam, NULL)))
+        if(NULL == (bt2_corder = H5B2_create(f, dxpl_id, &bt2_cparam, NULL, parent)))
             HGOTO_ERROR(H5E_ATTR, H5E_CANTINIT, FAIL, "unable to create v2 B-tree for creation order index")
 
         /* Retrieve the v2 B-tree's address in the file */
@@ -339,7 +341,8 @@ H5A_dense_fnd_cb(const H5A_t *attr, hbool_t *took_ownership, void *_user_attr)
  *-------------------------------------------------------------------------
  */
 H5A_t *
-H5A_dense_open(H5F_t *f, hid_t dxpl_id, const H5O_ainfo_t *ainfo, const char *name)
+H5A_dense_open(H5F_t *f, hid_t dxpl_id, const H5O_ainfo_t *ainfo,
+    const char *name, void *parent)
 {
     H5A_bt2_ud_common_t udata;          /* User data for v2 B-tree modify */
     H5HF_t *fheap = NULL;               /* Fractal heap handle */
@@ -383,7 +386,7 @@ H5A_dense_open(H5F_t *f, hid_t dxpl_id, const H5O_ainfo_t *ainfo, const char *na
     } /* end if */
 
     /* Open the name index v2 B-tree */
-    if(NULL == (bt2_name = H5B2_open(f, dxpl_id, ainfo->name_bt2_addr, NULL)))
+    if(NULL == (bt2_name = H5B2_open(f, dxpl_id, ainfo->name_bt2_addr, NULL, parent)))
         HGOTO_ERROR(H5E_ATTR, H5E_CANTOPENOBJ, NULL, "unable to open v2 B-tree for name index")
 
     /* Create the "udata" information for v2 B-tree record find */
@@ -442,6 +445,7 @@ H5A_dense_insert(H5F_t *f, hid_t dxpl_id, const H5O_ainfo_t *ainfo, H5A_t *attr)
     uint8_t attr_buf[H5A_ATTR_BUF_SIZE]; /* Buffer for serializing message */
     unsigned mesg_flags = 0;            /* Flags for storing message */
     htri_t attr_sharable;               /* Flag indicating attributes are sharable */
+    H5O_t *oh = NULL;                   /* Attribute's object header */
     herr_t ret_value = SUCCEED;         /* Return value */
 
     FUNC_ENTER_NOAPI(FAIL)
@@ -527,8 +531,15 @@ H5A_dense_insert(H5F_t *f, hid_t dxpl_id, const H5O_ainfo_t *ainfo, H5A_t *attr)
             HGOTO_ERROR(H5E_ATTR, H5E_CANTINSERT, FAIL, "unable to insert attribute into fractal heap")
     } /* end else */
 
+    /* Check for SWMR writes to the file */
+    if(H5F_INTENT(f) & H5F_ACC_SWMR_WRITE)
+        /* Pin the attribute's object header */
+        /*!FIXME change to use ohdr proxy once those changes are merged -NAF */
+        if(NULL == (oh = H5O_pin(&attr->oloc, dxpl_id)))
+            HGOTO_ERROR(H5E_ATTR, H5E_CANTPIN, FAIL, "unable to pin attribute object header")
+
     /* Open the name index v2 B-tree */
-    if(NULL == (bt2_name = H5B2_open(f, dxpl_id, ainfo->name_bt2_addr, NULL)))
+    if(NULL == (bt2_name = H5B2_open(f, dxpl_id, ainfo->name_bt2_addr, NULL, oh)))
         HGOTO_ERROR(H5E_ATTR, H5E_CANTOPENOBJ, FAIL, "unable to open v2 B-tree for name index")
 
     /* Create the callback information for v2 B-tree record insertion */
@@ -551,8 +562,9 @@ H5A_dense_insert(H5F_t *f, hid_t dxpl_id, const H5O_ainfo_t *ainfo, H5A_t *attr)
     /* Check if we should create a creation order index v2 B-tree record */
     if(ainfo->index_corder) {
         /* Open the creation order index v2 B-tree */
+        /*!FIXME use ohdr proxy -NAF */
         HDassert(H5F_addr_defined(ainfo->corder_bt2_addr));
-        if(NULL == (bt2_corder = H5B2_open(f, dxpl_id, ainfo->corder_bt2_addr, NULL)))
+        if(NULL == (bt2_corder = H5B2_open(f, dxpl_id, ainfo->corder_bt2_addr, NULL, oh)))
             HGOTO_ERROR(H5E_ATTR, H5E_CANTOPENOBJ, FAIL, "unable to open v2 B-tree for creation order index")
 
         /* Insert the record into the creation order index v2 B-tree */
@@ -562,6 +574,8 @@ H5A_dense_insert(H5F_t *f, hid_t dxpl_id, const H5O_ainfo_t *ainfo, H5A_t *attr)
 
 done:
     /* Release resources */
+    if(oh && H5O_unpin(oh) < 0)
+        HDONE_ERROR(H5E_ATTR, H5E_CANTUNPIN, FAIL, "unable to unpin attribute object header")
     if(shared_fheap && H5HF_close(shared_fheap, dxpl_id) < 0)
         HDONE_ERROR(H5E_ATTR, H5E_CLOSEERROR, FAIL, "can't close fractal heap")
     if(fheap && H5HF_close(fheap, dxpl_id) < 0)
@@ -636,6 +650,7 @@ H5A_dense_write_bt2_cb(void *_record, void *_op_data, hbool_t *changed)
     H5B2_t *bt2_corder = NULL;          /* v2 B-tree handle for creation order index */
     H5WB_t *wb = NULL;                  /* Wrapped buffer for attribute data */
     uint8_t attr_buf[H5A_ATTR_BUF_SIZE]; /* Buffer for serializing attribute */
+    H5O_t *oh = NULL;                   /* Attribute's object header */
     herr_t ret_value = SUCCEED;         /* Return value */
 
     FUNC_ENTER_NOAPI_NOINIT
@@ -659,8 +674,16 @@ H5A_dense_write_bt2_cb(void *_record, void *_op_data, hbool_t *changed)
         if(H5F_addr_defined(op_data->corder_bt2_addr)) {
             H5A_bt2_ud_common_t udata;          /* User data for v2 B-tree modify */
 
+            /* Check for SWMR writes to the file */
+            if(H5F_INTENT(op_data->f) & H5F_ACC_SWMR_WRITE)
+                /* Pin the attribute's object header */
+                /*!FIXME change to use ohdr proxy once those changes are merged -NAF */
+                if(NULL == (oh = H5O_pin(&op_data->attr->oloc, op_data->dxpl_id)))
+                    HGOTO_ERROR(H5E_ATTR, H5E_CANTPIN, FAIL, "unable to pin attribute object header")
+
             /* Open the creation order index v2 B-tree */
-            if(NULL == (bt2_corder = H5B2_open(op_data->f, op_data->dxpl_id, op_data->corder_bt2_addr, NULL)))
+            /*!FIXME use ohdr proxy -NAF */
+            if(NULL == (bt2_corder = H5B2_open(op_data->f, op_data->dxpl_id, op_data->corder_bt2_addr, NULL, oh)))
                 HGOTO_ERROR(H5E_ATTR, H5E_CANTOPENOBJ, FAIL, "unable to open v2 B-tree for creation order index")
 
             /* Create the "udata" information for v2 B-tree record modify */
@@ -721,6 +744,8 @@ H5A_dense_write_bt2_cb(void *_record, void *_op_data, hbool_t *changed)
 
 done:
     /* Release resources */
+    if(oh && H5O_unpin(oh) < 0)
+        HDONE_ERROR(H5E_ATTR, H5E_CANTUNPIN, FAIL, "unable to unpin attribute object header")
     if(bt2_corder && H5B2_close(bt2_corder, op_data->dxpl_id) < 0)
         HDONE_ERROR(H5E_ATTR, H5E_CLOSEERROR, FAIL, "can't close v2 B-tree for creation order index")
     if(wb && H5WB_unwrap(wb) < 0)
@@ -752,6 +777,7 @@ H5A_dense_write(H5F_t *f, hid_t dxpl_id, const H5O_ainfo_t *ainfo, H5A_t *attr)
     H5HF_t *shared_fheap = NULL;        /* Fractal heap handle for shared header messages */
     H5B2_t *bt2_name = NULL;            /* v2 B-tree handle for name index */
     htri_t attr_sharable;               /* Flag indicating attributes are sharable */
+    H5O_t *oh = NULL;                   /* Attribute's object header */
     herr_t ret_value = SUCCEED;         /* Return value */
 
     FUNC_ENTER_NOAPI(FAIL)
@@ -789,8 +815,16 @@ H5A_dense_write(H5F_t *f, hid_t dxpl_id, const H5O_ainfo_t *ainfo, H5A_t *attr)
     if(NULL == (fheap = H5HF_open(f, dxpl_id, ainfo->fheap_addr)))
         HGOTO_ERROR(H5E_ATTR, H5E_CANTOPENOBJ, FAIL, "unable to open fractal heap")
 
+    /* Check for SWMR writes to the file */
+    if(H5F_INTENT(f) & H5F_ACC_SWMR_WRITE)
+        /* Pin the attribute's object header */
+        /*!FIXME change to use ohdr proxy once those changes are merged -NAF */
+        if(NULL == (oh = H5O_pin(&attr->oloc, dxpl_id)))
+            HGOTO_ERROR(H5E_ATTR, H5E_CANTPIN, FAIL, "unable to pin attribute object header")
+
     /* Open the name index v2 B-tree */
-    if(NULL == (bt2_name = H5B2_open(f, dxpl_id, ainfo->name_bt2_addr, NULL)))
+    /*!FIXME use ohdr proxy -NAF */
+    if(NULL == (bt2_name = H5B2_open(f, dxpl_id, ainfo->name_bt2_addr, NULL, oh)))
         HGOTO_ERROR(H5E_ATTR, H5E_CANTOPENOBJ, FAIL, "unable to open v2 B-tree for name index")
 
     /* Create the "udata" information for v2 B-tree record modify */
@@ -819,6 +853,8 @@ H5A_dense_write(H5F_t *f, hid_t dxpl_id, const H5O_ainfo_t *ainfo, H5A_t *attr)
 
 done:
     /* Release resources */
+    if(oh && H5O_unpin(oh) < 0)
+        HDONE_ERROR(H5E_ATTR, H5E_CANTUNPIN, FAIL, "unable to unpin attribute object header")
     if(shared_fheap && H5HF_close(shared_fheap, dxpl_id) < 0)
         HDONE_ERROR(H5E_ATTR, H5E_CLOSEERROR, FAIL, "can't close fractal heap")
     if(fheap && H5HF_close(fheap, dxpl_id) < 0)
@@ -888,8 +924,8 @@ done:
  *-------------------------------------------------------------------------
  */
 herr_t
-H5A_dense_rename(H5F_t *f, hid_t dxpl_id, const H5O_ainfo_t *ainfo, const char *old_name,
-    const char *new_name)
+H5A_dense_rename(H5F_t *f, hid_t dxpl_id, const H5O_ainfo_t *ainfo,
+    const char *old_name, const char *new_name, void *parent)
 {
     H5A_bt2_ud_common_t udata;          /* User data for v2 B-tree modify */
     H5HF_t *fheap = NULL;               /* Fractal heap handle */
@@ -936,7 +972,7 @@ H5A_dense_rename(H5F_t *f, hid_t dxpl_id, const H5O_ainfo_t *ainfo, const char *
         HGOTO_ERROR(H5E_ATTR, H5E_CANTOPENOBJ, FAIL, "unable to open fractal heap")
 
     /* Open the name index v2 B-tree */
-    if(NULL == (bt2_name = H5B2_open(f, dxpl_id, ainfo->name_bt2_addr, NULL)))
+    if(NULL == (bt2_name = H5B2_open(f, dxpl_id, ainfo->name_bt2_addr, NULL, parent)))
         HGOTO_ERROR(H5E_ATTR, H5E_CANTOPENOBJ, FAIL, "unable to open v2 B-tree for name index")
 
     /* Create the "udata" information for v2 B-tree record modify */
@@ -1011,7 +1047,7 @@ H5A_dense_rename(H5F_t *f, hid_t dxpl_id, const H5O_ainfo_t *ainfo, const char *
 	HGOTO_ERROR(H5E_ATTR, H5E_WRITEERROR, FAIL, "error determining if message should be shared")
 
     /* Delete old attribute from dense storage */
-    if(H5A_dense_remove(f, dxpl_id, ainfo, old_name) < 0)
+    if(H5A_dense_remove(f, dxpl_id, ainfo, old_name, parent) < 0)
         HGOTO_ERROR(H5E_ATTR, H5E_CANTDELETE, FAIL, "unable to delete attribute in dense storage")
 
 done:
@@ -1140,8 +1176,9 @@ done:
  *-------------------------------------------------------------------------
  */
 herr_t
-H5A_dense_iterate(H5F_t *f, hid_t dxpl_id, hid_t loc_id, const H5O_ainfo_t *ainfo,
-    H5_index_t idx_type, H5_iter_order_t order, hsize_t skip, hsize_t *last_attr,
+H5A_dense_iterate(H5F_t *f, hid_t dxpl_id, hid_t loc_id,
+    const H5O_ainfo_t *ainfo, H5_index_t idx_type, H5_iter_order_t order,
+    hsize_t skip, void *parent, hsize_t *last_attr,
     const H5A_attr_iter_op_t *attr_op, void *op_data)
 {
     H5HF_t *fheap = NULL;               /* Fractal heap handle */
@@ -1215,7 +1252,7 @@ H5A_dense_iterate(H5F_t *f, hid_t dxpl_id, hid_t loc_id, const H5O_ainfo_t *ainf
         } /* end if */
 
         /* Open the index v2 B-tree */
-        if(NULL == (bt2 = H5B2_open(f, dxpl_id, bt2_addr, NULL)))
+        if(NULL == (bt2 = H5B2_open(f, dxpl_id, bt2_addr, NULL, parent)))
             HGOTO_ERROR(H5E_ATTR, H5E_CANTOPENOBJ, FAIL, "unable to open v2 B-tree for index")
 
         /* Construct the user data for v2 B-tree iterator callback */
@@ -1241,7 +1278,7 @@ H5A_dense_iterate(H5F_t *f, hid_t dxpl_id, hid_t loc_id, const H5O_ainfo_t *ainf
     else {
         /* Build the table of attributes for this object */
         /* (build table using the name index, but sort according to idx_type) */
-        if(H5A_dense_build_table(f, dxpl_id, ainfo, idx_type, order, &atable) < 0)
+        if(H5A_dense_build_table(f, dxpl_id, ainfo, idx_type, order, parent, &atable) < 0)
             HGOTO_ERROR(H5E_ATTR, H5E_CANTGET, FAIL, "error building table of attributes")
 
         /* Iterate over attributes in table */
@@ -1291,7 +1328,7 @@ H5A_dense_remove_bt2_cb(const void *_record, void *_udata)
     /* Check for removing the link from the creation order index */
     if(H5F_addr_defined(udata->corder_bt2_addr)) {
         /* Open the creation order index v2 B-tree */
-        if(NULL == (bt2_corder = H5B2_open(udata->common.f, udata->common.dxpl_id, udata->corder_bt2_addr, NULL)))
+        if(NULL == (bt2_corder = H5B2_open(udata->common.f, udata->common.dxpl_id, udata->corder_bt2_addr, NULL, udata->parent)))
             HGOTO_ERROR(H5E_ATTR, H5E_CANTOPENOBJ, FAIL, "unable to open v2 B-tree for creation order index")
 
         /* Set up the user data for the v2 B-tree 'record remove' callback */
@@ -1342,7 +1379,8 @@ done:
  *-------------------------------------------------------------------------
  */
 herr_t
-H5A_dense_remove(H5F_t *f, hid_t dxpl_id, const H5O_ainfo_t *ainfo, const char *name)
+H5A_dense_remove(H5F_t *f, hid_t dxpl_id, const H5O_ainfo_t *ainfo,
+    const char *name, void *parent)
 {
     H5A_bt2_ud_rm_t udata;              /* User data for v2 B-tree record removal */
     H5HF_t *fheap = NULL;               /* Fractal heap handle */
@@ -1386,7 +1424,7 @@ H5A_dense_remove(H5F_t *f, hid_t dxpl_id, const H5O_ainfo_t *ainfo, const char *
     } /* end if */
 
     /* Open the name index v2 B-tree */
-    if(NULL == (bt2_name = H5B2_open(f, dxpl_id, ainfo->name_bt2_addr, NULL)))
+    if(NULL == (bt2_name = H5B2_open(f, dxpl_id, ainfo->name_bt2_addr, NULL, parent)))
         HGOTO_ERROR(H5E_ATTR, H5E_CANTOPENOBJ, FAIL, "unable to open v2 B-tree for name index")
 
     /* Set up the user data for the v2 B-tree 'record remove' callback */
@@ -1399,6 +1437,7 @@ H5A_dense_remove(H5F_t *f, hid_t dxpl_id, const H5O_ainfo_t *ainfo, const char *
     udata.common.found_op = H5A_dense_fnd_cb;       /* v2 B-tree comparison callback */
     udata.common.found_op_data = &attr_copy;
     udata.corder_bt2_addr = ainfo->corder_bt2_addr;
+    udata.parent = parent;
 
     /* Remove the record from the name index v2 B-tree */
     if(H5B2_remove(bt2_name, dxpl_id, &udata, H5A_dense_remove_bt2_cb, &udata) < 0)
@@ -1500,7 +1539,7 @@ H5A_dense_remove_by_idx_bt2_cb(const void *_record, void *_bt2_udata)
         } /* end else */
 
         /* Open the index v2 B-tree */
-        if(NULL == (bt2 = H5B2_open(bt2_udata->f, bt2_udata->dxpl_id, bt2_udata->other_bt2_addr, NULL)))
+        if(NULL == (bt2 = H5B2_open(bt2_udata->f, bt2_udata->dxpl_id, bt2_udata->other_bt2_addr, NULL, bt2_udata->parent)))
             HGOTO_ERROR(H5E_ATTR, H5E_CANTOPENOBJ, FAIL, "unable to open v2 B-tree for index")
 
         /* Set the common information for the v2 B-tree remove operation */
@@ -1562,7 +1601,7 @@ done:
  */
 herr_t
 H5A_dense_remove_by_idx(H5F_t *f, hid_t dxpl_id, const H5O_ainfo_t *ainfo,
-    H5_index_t idx_type, H5_iter_order_t order, hsize_t n)
+    H5_index_t idx_type, H5_iter_order_t order, hsize_t n, void *parent)
 {
     H5HF_t *fheap = NULL;               /* Fractal heap handle */
     H5HF_t *shared_fheap = NULL;        /* Fractal heap handle for shared header messages */
@@ -1632,7 +1671,7 @@ H5A_dense_remove_by_idx(H5F_t *f, hid_t dxpl_id, const H5O_ainfo_t *ainfo,
         } /* end if */
 
         /* Open the index v2 B-tree */
-        if(NULL == (bt2 = H5B2_open(f, dxpl_id, bt2_addr, NULL)))
+        if(NULL == (bt2 = H5B2_open(f, dxpl_id, bt2_addr, NULL, parent)))
             HGOTO_ERROR(H5E_ATTR, H5E_CANTOPENOBJ, FAIL, "unable to open v2 B-tree for index")
 
         /* Set up the user data for the v2 B-tree 'record remove' callback */
@@ -1642,15 +1681,16 @@ H5A_dense_remove_by_idx(H5F_t *f, hid_t dxpl_id, const H5O_ainfo_t *ainfo,
         udata.shared_fheap = shared_fheap;
         udata.idx_type = idx_type;
         udata.other_bt2_addr = idx_type == H5_INDEX_NAME ? ainfo->corder_bt2_addr : ainfo->name_bt2_addr;
+        udata.parent = parent;
 
         /* Remove the record from the name index v2 B-tree */
-        if(H5B2_remove_by_idx(bt2, dxpl_id, order, n, H5A_dense_remove_by_idx_bt2_cb, &udata) < 0)
+        if(H5B2_remove_by_idx(bt2, dxpl_id, order, n, NULL, H5A_dense_remove_by_idx_bt2_cb, &udata) < 0)
             HGOTO_ERROR(H5E_ATTR, H5E_CANTREMOVE, FAIL, "unable to remove attribute from v2 B-tree index")
     } /* end if */
     else {
         /* Build the table of attributes for this object */
         /* (build table using the name index, but sort according to idx_type) */
-        if(H5A_dense_build_table(f, dxpl_id, ainfo, idx_type, order, &atable) < 0)
+        if(H5A_dense_build_table(f, dxpl_id, ainfo, idx_type, order, parent, &atable) < 0)
             HGOTO_ERROR(H5E_ATTR, H5E_CANTGET, FAIL, "error building table of attributes")
 
         /* Check for skipping too many attributes */
@@ -1658,7 +1698,7 @@ H5A_dense_remove_by_idx(H5F_t *f, hid_t dxpl_id, const H5O_ainfo_t *ainfo,
             HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid index specified")
 
         /* Delete appropriate attribute from dense storage */
-        if(H5A_dense_remove(f, dxpl_id, ainfo, ((atable.attrs[n])->shared)->name) < 0)
+        if(H5A_dense_remove(f, dxpl_id, ainfo, ((atable.attrs[n])->shared)->name, parent) < 0)
             HGOTO_ERROR(H5E_ATTR, H5E_CANTDELETE, FAIL, "unable to delete attribute in dense storage")
     } /* end else */
 
@@ -1692,7 +1732,8 @@ done:
  *-------------------------------------------------------------------------
  */
 htri_t
-H5A_dense_exists(H5F_t *f, hid_t dxpl_id, const H5O_ainfo_t *ainfo, const char *name)
+H5A_dense_exists(H5F_t *f, hid_t dxpl_id, const H5O_ainfo_t *ainfo,
+    const char *name, void *parent)
 {
     H5A_bt2_ud_common_t udata;          /* User data for v2 B-tree modify */
     H5HF_t *fheap = NULL;               /* Fractal heap handle */
@@ -1735,7 +1776,7 @@ H5A_dense_exists(H5F_t *f, hid_t dxpl_id, const H5O_ainfo_t *ainfo, const char *
     } /* end if */
 
     /* Open the name index v2 B-tree */
-    if(NULL == (bt2_name = H5B2_open(f, dxpl_id, ainfo->name_bt2_addr, NULL)))
+    if(NULL == (bt2_name = H5B2_open(f, dxpl_id, ainfo->name_bt2_addr, NULL, parent)))
         HGOTO_ERROR(H5E_ATTR, H5E_CANTOPENOBJ, FAIL, "unable to open v2 B-tree for name index")
 
     /* Create the "udata" information for v2 B-tree record 'find' */
@@ -1846,7 +1887,7 @@ done:
  *-------------------------------------------------------------------------
  */
 herr_t
-H5A_dense_delete(H5F_t *f, hid_t dxpl_id, H5O_ainfo_t *ainfo)
+H5A_dense_delete(H5F_t *f, hid_t dxpl_id, H5O_ainfo_t *ainfo, void *parent)
 {
     H5A_bt2_ud_common_t udata;          /* v2 B-tree user data for deleting attributes */
     H5HF_t *fheap = NULL;               /* Fractal heap handle */
@@ -1876,7 +1917,7 @@ H5A_dense_delete(H5F_t *f, hid_t dxpl_id, H5O_ainfo_t *ainfo)
     udata.found_op_data = NULL;
 
     /* Delete name index v2 B-tree */
-    if(H5B2_delete(f, dxpl_id, ainfo->name_bt2_addr, NULL, H5A_dense_delete_bt2_cb, &udata) < 0)
+    if(H5B2_delete(f, dxpl_id, ainfo->name_bt2_addr, NULL, parent, H5A_dense_delete_bt2_cb, &udata) < 0)
         HGOTO_ERROR(H5E_ATTR, H5E_CANTDELETE, FAIL, "unable to delete v2 B-tree for name index")
     ainfo->name_bt2_addr = HADDR_UNDEF;
 
@@ -1888,7 +1929,7 @@ H5A_dense_delete(H5F_t *f, hid_t dxpl_id, H5O_ainfo_t *ainfo)
     /* Check if we should delete the creation order index v2 B-tree */
     if(H5F_addr_defined(ainfo->corder_bt2_addr)) {
         /* Delete the creation order index, without adjusting the ref. count on the attributes  */
-        if(H5B2_delete(f, dxpl_id, ainfo->corder_bt2_addr, NULL, NULL, NULL) < 0)
+        if(H5B2_delete(f, dxpl_id, ainfo->corder_bt2_addr, NULL, parent, NULL, NULL) < 0)
             HGOTO_ERROR(H5E_ATTR, H5E_CANTDELETE, FAIL, "unable to delete v2 B-tree for creation order index")
         ainfo->corder_bt2_addr = HADDR_UNDEF;
     } /* end if */
diff --git a/src/H5Aint.c b/src/H5Aint.c
index 74c5590..14c2c65 100644
--- a/src/H5Aint.c
+++ b/src/H5Aint.c
@@ -308,7 +308,8 @@ done:
  */
 herr_t
 H5A_dense_build_table(H5F_t *f, hid_t dxpl_id, const H5O_ainfo_t *ainfo,
-    H5_index_t idx_type, H5_iter_order_t order, H5A_attr_table_t *atable)
+    H5_index_t idx_type, H5_iter_order_t order, void *parent,
+    H5A_attr_table_t *atable)
 {
     H5B2_t *bt2_name = NULL;            /* v2 B-tree handle for name index */
     hsize_t nrec;                       /* # of records in v2 B-tree */
@@ -324,7 +325,7 @@ H5A_dense_build_table(H5F_t *f, hid_t dxpl_id, const H5O_ainfo_t *ainfo,
     HDassert(atable);
 
     /* Open the name index v2 B-tree */
-    if(NULL == (bt2_name = H5B2_open(f, dxpl_id, ainfo->name_bt2_addr, NULL)))
+    if(NULL == (bt2_name = H5B2_open(f, dxpl_id, ainfo->name_bt2_addr, NULL, parent)))
         HGOTO_ERROR(H5E_ATTR, H5E_CANTOPENOBJ, FAIL, "unable to open v2 B-tree for name index")
 
     /* Retrieve # of records in "name" B-tree */
@@ -355,7 +356,7 @@ H5A_dense_build_table(H5F_t *f, hid_t dxpl_id, const H5O_ainfo_t *ainfo,
 
         /* Iterate over the links in the group, building a table of the link messages */
         if(H5A_dense_iterate(f, dxpl_id, (hid_t)0, ainfo, H5_INDEX_NAME,
-                H5_ITER_NATIVE, (hsize_t)0, NULL, &attr_op, &udata) < 0)
+                H5_ITER_NATIVE, (hsize_t)0, parent, NULL, &attr_op, &udata) < 0)
             HGOTO_ERROR(H5E_ATTR, H5E_CANTINIT, FAIL, "error building attribute table")
 
         /* Sort attribute table in correct iteration order */
@@ -711,7 +712,8 @@ H5A_get_ainfo(H5F_t *f, hid_t dxpl_id, H5O_t *oh, H5O_ainfo_t *ainfo)
             /* Check if we are using "dense" attribute storage */
             if(H5F_addr_defined(ainfo->fheap_addr)) {
                 /* Open the name index v2 B-tree */
-                if(NULL == (bt2_name = H5B2_open(f, dxpl_id, ainfo->name_bt2_addr, NULL)))
+                /*!FIXME use ohdr proxy -NAF */
+                if(NULL == (bt2_name = H5B2_open(f, dxpl_id, ainfo->name_bt2_addr, NULL, oh)))
                     HGOTO_ERROR(H5E_ATTR, H5E_CANTOPENOBJ, FAIL, "unable to open v2 B-tree for name index")
 
                 /* Retrieve # of records in "name" B-tree */
@@ -1252,7 +1254,7 @@ H5A_dense_post_copy_file_all(const H5O_loc_t *src_oloc, const H5O_ainfo_t *ainfo
 
 
      if(H5A_dense_iterate(src_oloc->file, dxpl_id, (hid_t)0, ainfo_src, H5_INDEX_NAME,
-            H5_ITER_NATIVE, (hsize_t)0, NULL, &attr_op, &udata) < 0)
+            H5_ITER_NATIVE, (hsize_t)0, NULL, NULL, &attr_op, &udata) < 0)
         HGOTO_ERROR(H5E_ATTR, H5E_CANTINIT, FAIL, "error building attribute table")
 
 done:
diff --git a/src/H5Apkg.h b/src/H5Apkg.h
index 26c8dff..c1d0c90 100644
--- a/src/H5Apkg.h
+++ b/src/H5Apkg.h
@@ -200,26 +200,29 @@ H5_DLL htri_t H5A_get_ainfo(H5F_t *f, hid_t dxpl_id, H5O_t *oh, H5O_ainfo_t *ain
 H5_DLL herr_t H5A_set_version(const H5F_t *f, H5A_t *attr);
 
 /* Attribute "dense" storage routines */
-H5_DLL herr_t H5A_dense_create(H5F_t *f, hid_t dxpl_id, H5O_ainfo_t *ainfo);
+H5_DLL herr_t H5A_dense_create(H5F_t *f, hid_t dxpl_id, H5O_ainfo_t *ainfo,
+    void *parent);
 H5_DLL H5A_t *H5A_dense_open(H5F_t *f, hid_t dxpl_id, const H5O_ainfo_t *ainfo,
-    const char *name);
+    const char *name, void *parent);
 H5_DLL herr_t H5A_dense_insert(H5F_t *f, hid_t dxpl_id, const H5O_ainfo_t *ainfo,
     H5A_t *attr);
 H5_DLL herr_t H5A_dense_write(H5F_t *f, hid_t dxpl_id, const H5O_ainfo_t *ainfo,
     H5A_t *attr);
 H5_DLL herr_t H5A_dense_rename(H5F_t *f, hid_t dxpl_id, const H5O_ainfo_t *ainfo,
-    const char *old_name, const char *new_name);
+    const char *old_name, const char *new_name, void *parent);
 H5_DLL herr_t H5A_dense_iterate(H5F_t *f, hid_t dxpl_id, hid_t loc_id,
     const H5O_ainfo_t *ainfo, H5_index_t idx_type, H5_iter_order_t order,
-    hsize_t skip, hsize_t *last_attr, const H5A_attr_iter_op_t *attr_op,
+    hsize_t skip, void *parent, hsize_t *last_attr, const H5A_attr_iter_op_t *attr_op,
     void *op_data);
-H5_DLL herr_t H5A_dense_remove(H5F_t *f, hid_t dxpl_id, const H5O_ainfo_t *ainfo,
-    const char *name);
-H5_DLL herr_t H5A_dense_remove_by_idx(H5F_t *f, hid_t dxpl_id, const H5O_ainfo_t *ainfo,
-    H5_index_t idx_type, H5_iter_order_t order, hsize_t n);
+H5_DLL herr_t H5A_dense_remove(H5F_t *f, hid_t dxpl_id,
+    const H5O_ainfo_t *ainfo, const char *name, void *parent);
+H5_DLL herr_t H5A_dense_remove_by_idx(H5F_t *f, hid_t dxpl_id,
+    const H5O_ainfo_t *ainfo, H5_index_t idx_type, H5_iter_order_t order,
+    hsize_t n, void *parent);
 H5_DLL htri_t H5A_dense_exists(H5F_t *f, hid_t dxpl_id, const H5O_ainfo_t *ainfo,
-    const char *name);
-H5_DLL herr_t H5A_dense_delete(H5F_t *f, hid_t dxpl_id, H5O_ainfo_t *ainfo);
+    const char *name, void *parent);
+H5_DLL herr_t H5A_dense_delete(H5F_t *f, hid_t dxpl_id, H5O_ainfo_t *ainfo,
+    void *parent);
 
 
 /* Attribute table operations */
@@ -227,7 +230,7 @@ H5_DLL herr_t H5A_compact_build_table(H5F_t *f, hid_t dxpl_id, H5O_t *oh,
     H5_index_t idx_type, H5_iter_order_t order, H5A_attr_table_t *atable);
 H5_DLL herr_t H5A_dense_build_table(H5F_t *f, hid_t dxpl_id,
     const H5O_ainfo_t *ainfo, H5_index_t idx_type, H5_iter_order_t order,
-    H5A_attr_table_t *atable);
+    void *parent, H5A_attr_table_t *atable);
 H5_DLL herr_t H5A_attr_iterate_table(const H5A_attr_table_t *atable,
     hsize_t skip, hsize_t *last_attr, hid_t loc_id,
     const H5A_attr_iter_op_t *attr_op, void *op_data);
diff --git a/src/H5B2.c b/src/H5B2.c
index 003f83e..5a77c30 100644
--- a/src/H5B2.c
+++ b/src/H5B2.c
@@ -130,7 +130,8 @@ H5FL_DEFINE_STATIC(H5B2_t);
  *-------------------------------------------------------------------------
  */
 H5B2_t *
-H5B2_create(H5F_t *f, hid_t dxpl_id, const H5B2_create_t *cparam, void *ctx_udata)
+H5B2_create(H5F_t *f, hid_t dxpl_id, const H5B2_create_t *cparam,
+    void *ctx_udata, void *parent)
 {
     H5B2_t	*bt2 = NULL;            /* Pointer to the B-tree */
     H5B2_hdr_t	*hdr = NULL;            /* Pointer to the B-tree header */
@@ -150,7 +151,7 @@ H5B2_create(H5F_t *f, hid_t dxpl_id, const H5B2_create_t *cparam, void *ctx_udat
     HDcompile_assert(H5B2_NUM_BTREE_ID == NELMTS(H5B2_client_class_g));
 
     /* Create shared v2 B-tree header */
-    if(HADDR_UNDEF == (hdr_addr = H5B2_hdr_create(f, dxpl_id, cparam, ctx_udata)))
+    if(HADDR_UNDEF == (hdr_addr = H5B2_hdr_create(f, dxpl_id, cparam, ctx_udata, parent)))
 	HGOTO_ERROR(H5E_BTREE, H5E_CANTINIT, NULL, "can't create v2 B-tree header")
 
     /* Create v2 B-tree wrapper */
@@ -159,6 +160,7 @@ H5B2_create(H5F_t *f, hid_t dxpl_id, const H5B2_create_t *cparam, void *ctx_udat
 
     /* Look up the B-tree header */
     cache_udata.f = f;
+    cache_udata.parent = parent;
     cache_udata.ctx_udata = ctx_udata;
     if(NULL == (hdr = (H5B2_hdr_t *)H5AC_protect(f, dxpl_id, H5AC_BT2_HDR, hdr_addr, &cache_udata, H5AC_WRITE)))
 	HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, NULL, "unable to load B-tree header")
@@ -204,7 +206,7 @@ done:
  *-------------------------------------------------------------------------
  */
 H5B2_t *
-H5B2_open(H5F_t *f, hid_t dxpl_id, haddr_t addr, void *ctx_udata)
+H5B2_open(H5F_t *f, hid_t dxpl_id, haddr_t addr, void *ctx_udata, void *parent)
 {
     H5B2_t	*bt2 = NULL;            /* Pointer to the B-tree */
     H5B2_hdr_t	*hdr = NULL;            /* Pointer to the B-tree header */
@@ -219,6 +221,7 @@ H5B2_open(H5F_t *f, hid_t dxpl_id, haddr_t addr, void *ctx_udata)
 
     /* Look up the B-tree header */
     cache_udata.f = f;
+    cache_udata.parent = parent;
     cache_udata.ctx_udata = ctx_udata;
     if(NULL == (hdr = (H5B2_hdr_t *)H5AC_protect(f, dxpl_id, H5AC_BT2_HDR, addr, &cache_udata, H5AC_READ)))
 	HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, NULL, "unable to load B-tree header")
@@ -291,23 +294,23 @@ H5B2_insert(H5B2_t *bt2, hid_t dxpl_id, void *udata)
     /* Check if the root node is allocated yet */
     if(!H5F_addr_defined(hdr->root.addr)) {
         /* Create root node as leaf node in B-tree */
-        if(H5B2_create_leaf(hdr, dxpl_id, &(hdr->root)) < 0)
+        if(H5B2_create_leaf(hdr, dxpl_id, hdr, &(hdr->root)) < 0)
 	    HGOTO_ERROR(H5E_BTREE, H5E_CANTINIT, FAIL, "unable to create root node")
     } /* end if */
     /* Check if we need to split the root node (equiv. to a 1->2 node split) */
     else if(hdr->root.node_nrec == hdr->node_info[hdr->depth].split_nrec) {
         /* Split root node */
-        if(H5B2_split_root(hdr, dxpl_id) < 0)
+        if(H5B2_split_root(hdr, dxpl_id, udata) < 0)
             HGOTO_ERROR(H5E_BTREE, H5E_CANTSPLIT, FAIL, "unable to split root node")
     } /* end if */
 
     /* Attempt to insert record into B-tree */
     if(hdr->depth > 0) {
-        if(H5B2_insert_internal(hdr, dxpl_id, hdr->depth, NULL, &hdr->root, udata) < 0)
+        if(H5B2_insert_internal(hdr, dxpl_id, hdr->depth, NULL, &hdr->root, hdr, udata) < 0)
             HGOTO_ERROR(H5E_BTREE, H5E_CANTINSERT, FAIL, "unable to insert record into B-tree internal node")
     } /* end if */
     else {
-        if(H5B2_insert_leaf(hdr, dxpl_id, &hdr->root, udata) < 0)
+        if(H5B2_insert_leaf(hdr, dxpl_id, &hdr->root, hdr, udata) < 0)
             HGOTO_ERROR(H5E_BTREE, H5E_CANTINSERT, FAIL, "unable to insert record into B-tree leaf node")
     } /* end else */
 
@@ -389,7 +392,7 @@ H5B2_iterate(H5B2_t *bt2, hid_t dxpl_id, H5B2_operator_t op, void *op_data)
     /* Iterate through records */
     if(hdr->root.node_nrec > 0) {
         /* Iterate through nodes */
-        if((ret_value = H5B2_iterate_node(hdr, dxpl_id, hdr->depth, &hdr->root, op, op_data)) < 0)
+        if((ret_value = H5B2_iterate_node(hdr, dxpl_id, hdr->depth, &hdr->root, hdr, op, op_data)) < 0)
             HERROR(H5E_BTREE, H5E_CANTLIST, "node iteration failed");
     } /* end if */
 
@@ -426,6 +429,7 @@ H5B2_find(H5B2_t *bt2, hid_t dxpl_id, void *udata, H5B2_found_t op,
 {
     H5B2_hdr_t	*hdr;                   /* Pointer to the B-tree header */
     H5B2_node_ptr_t curr_node_ptr;      /* Node pointer info for current node */
+    void        *parent = NULL;         /* Parent of current node */
     unsigned    depth;                  /* Current depth of the tree */
     int         cmp;                    /* Comparison value of records */
     unsigned    idx;                    /* Location of record which matches key */
@@ -445,23 +449,34 @@ H5B2_find(H5B2_t *bt2, hid_t dxpl_id, void *udata, H5B2_found_t op,
     /* Make copy of the root node pointer to start search with */
     curr_node_ptr = hdr->root;
 
-    /* Current depth of the tree */
-    depth = hdr->depth;
-
     /* Check for empty tree */
     if(curr_node_ptr.node_nrec == 0)
         HGOTO_DONE(FALSE)
 
+    /* Current depth of the tree */
+    depth = hdr->depth;
+
+    /* Set initial parent, if doing swmr writes */
+    if(hdr->swmr_write)
+        parent = hdr;
+
     /* Walk down B-tree to find record or leaf node where record is located */
     cmp = -1;
-    while(depth > 0 && cmp != 0) {
+    while(depth > 0) {
         H5B2_internal_t *internal;          /* Pointer to internal node in B-tree */
         H5B2_node_ptr_t next_node_ptr;      /* Node pointer info for next node */
 
         /* Lock B-tree current node */
-        if(NULL == (internal = H5B2_protect_internal(hdr, dxpl_id, curr_node_ptr.addr, curr_node_ptr.node_nrec, depth, H5AC_READ)))
+        if(NULL == (internal = H5B2_protect_internal(hdr, dxpl_id, curr_node_ptr.addr, parent, curr_node_ptr.node_nrec, depth, H5AC_READ)))
             HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to load B-tree internal node")
 
+        /* Unpin parent if necessary */
+        if(parent) {
+            if(parent != hdr && H5AC_unpin_entry(parent) < 0)
+                HGOTO_ERROR(H5E_BTREE, H5E_CANTUNPIN, FAIL, "unable to unpin parent entry")
+            parent = NULL;
+        } /* end if */
+
         /* Locate node pointer for child */
         cmp = H5B2_locate_record(hdr->cls, internal->nrec, hdr->nat_off, internal->int_native, udata, &idx);
         if(cmp > 0)
@@ -472,9 +487,13 @@ H5B2_find(H5B2_t *bt2, hid_t dxpl_id, void *udata, H5B2_found_t op,
             next_node_ptr=internal->node_ptrs[idx];
 
             /* Unlock current node */
-            if(H5AC_unprotect(hdr->f, dxpl_id, H5AC_BT2_INT, curr_node_ptr.addr, internal, H5AC__NO_FLAGS_SET) < 0)
+            if(H5AC_unprotect(hdr->f, dxpl_id, H5AC_BT2_INT, curr_node_ptr.addr, internal, hdr->swmr_write ? H5AC__PIN_ENTRY_FLAG : H5AC__NO_FLAGS_SET) < 0)
                 HGOTO_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, FAIL, "unable to release B-tree node")
 
+            /* Keep track of parent if necessary */
+            if(hdr->swmr_write)
+                parent = internal;
+
             /* Set pointer to next node to load */
             curr_node_ptr = next_node_ptr;
         } /* end if */
@@ -504,9 +523,16 @@ H5B2_find(H5B2_t *bt2, hid_t dxpl_id, void *udata, H5B2_found_t op,
         H5B2_leaf_t *leaf;          /* Pointer to leaf node in B-tree */
 
         /* Lock B-tree leaf node */
-        if(NULL == (leaf = H5B2_protect_leaf(hdr, dxpl_id, curr_node_ptr.addr, curr_node_ptr.node_nrec, H5AC_READ)))
+        if(NULL == (leaf = H5B2_protect_leaf(hdr, dxpl_id, curr_node_ptr.addr, parent, curr_node_ptr.node_nrec, H5AC_READ)))
             HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree leaf node")
 
+        /* Unpin parent if necessary */
+        if(parent) {
+            if(parent != hdr && H5AC_unpin_entry(parent) < 0)
+                HGOTO_ERROR(H5E_BTREE, H5E_CANTUNPIN, FAIL, "unable to unpin parent entry")
+            parent = NULL;
+        } /* end if */
+
         /* Locate record */
         cmp = H5B2_locate_record(hdr->cls, leaf->nrec, hdr->nat_off, leaf->leaf_native, udata, &idx);
 
@@ -535,6 +561,12 @@ H5B2_find(H5B2_t *bt2, hid_t dxpl_id, void *udata, H5B2_found_t op,
     } /* end block */
 
 done:
+    if(parent) {
+        HDassert(ret_value < 0);
+        if(parent != hdr && H5AC_unpin_entry(parent) < 0)
+            HDONE_ERROR(H5E_BTREE, H5E_CANTUNPIN, FAIL, "unable to unpin parent entry")
+    } /* end if */
+
     FUNC_LEAVE_NOAPI(ret_value)
 } /* H5B2_find() */
 
@@ -563,6 +595,7 @@ H5B2_index(H5B2_t *bt2, hid_t dxpl_id, H5_iter_order_t order, hsize_t idx,
 {
     H5B2_hdr_t	*hdr;                   /* Pointer to the B-tree header */
     H5B2_node_ptr_t curr_node_ptr;      /* Node pointer info for current node */
+    void        *parent = NULL;         /* Parent of current node */
     unsigned    depth;                  /* Current depth of the tree */
     herr_t	ret_value = SUCCEED;    /* Return value */
 
@@ -581,9 +614,6 @@ H5B2_index(H5B2_t *bt2, hid_t dxpl_id, H5_iter_order_t order, hsize_t idx,
     /* Make copy of the root node pointer to start search with */
     curr_node_ptr = hdr->root;
 
-    /* Current depth of the tree */
-    depth = hdr->depth;
-
     /* Check for empty tree */
     if(curr_node_ptr.node_nrec == 0)
         HGOTO_ERROR(H5E_BTREE, H5E_NOTFOUND, FAIL, "B-tree has no records")
@@ -592,6 +622,13 @@ H5B2_index(H5B2_t *bt2, hid_t dxpl_id, H5_iter_order_t order, hsize_t idx,
     if(idx >= curr_node_ptr.all_nrec)
         HGOTO_ERROR(H5E_BTREE, H5E_NOTFOUND, FAIL, "B-tree doesn't have that many records")
 
+    /* Current depth of the tree */
+    depth = hdr->depth;
+
+    /* Set initial parent, if doing swmr writes */
+    if(hdr->swmr_write)
+        parent = hdr;
+
     /* Check for reverse indexing and map requested index to appropriate forward index */
     if(order == H5_ITER_DEC)
         idx = curr_node_ptr.all_nrec - (idx + 1);
@@ -603,9 +640,16 @@ H5B2_index(H5B2_t *bt2, hid_t dxpl_id, H5_iter_order_t order, hsize_t idx,
         unsigned u;                         /* Local index variable */
 
         /* Lock B-tree current node */
-        if(NULL == (internal = H5B2_protect_internal(hdr, dxpl_id, curr_node_ptr.addr, curr_node_ptr.node_nrec, depth, H5AC_READ)))
+        if(NULL == (internal = H5B2_protect_internal(hdr, dxpl_id, curr_node_ptr.addr, parent, curr_node_ptr.node_nrec, depth, H5AC_READ)))
             HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to load B-tree internal node")
 
+        /* Unpin parent if necessary */
+        if(parent) {
+            if(parent != hdr && H5AC_unpin_entry(parent) < 0)
+                HGOTO_ERROR(H5E_BTREE, H5E_CANTUNPIN, FAIL, "unable to unpin parent entry")
+            parent = NULL;
+        } /* end if */
+
         /* Search for record with correct index */
         for(u = 0; u < internal->nrec; u++) {
             /* Check if record is in child node */
@@ -614,9 +658,13 @@ H5B2_index(H5B2_t *bt2, hid_t dxpl_id, H5_iter_order_t order, hsize_t idx,
                 next_node_ptr = internal->node_ptrs[u];
 
                 /* Unlock current node */
-                if(H5AC_unprotect(hdr->f, dxpl_id, H5AC_BT2_INT, curr_node_ptr.addr, internal, H5AC__NO_FLAGS_SET) < 0)
+                if(H5AC_unprotect(hdr->f, dxpl_id, H5AC_BT2_INT, curr_node_ptr.addr, internal, hdr->swmr_write ? H5AC__PIN_ENTRY_FLAG : H5AC__NO_FLAGS_SET) < 0)
                     HGOTO_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, FAIL, "unable to release B-tree node")
 
+                /* Keep track of parent if necessary */
+                if(hdr->swmr_write)
+                    parent = internal;
+
                 /* Set pointer to next node to load */
                 curr_node_ptr = next_node_ptr;
 
@@ -656,9 +704,13 @@ H5B2_index(H5B2_t *bt2, hid_t dxpl_id, H5_iter_order_t order, hsize_t idx,
                 next_node_ptr = internal->node_ptrs[u];
 
                 /* Unlock current node */
-                if(H5AC_unprotect(hdr->f, dxpl_id, H5AC_BT2_INT, curr_node_ptr.addr, internal, H5AC__NO_FLAGS_SET) < 0)
+                if(H5AC_unprotect(hdr->f, dxpl_id, H5AC_BT2_INT, curr_node_ptr.addr, internal, hdr->swmr_write ? H5AC__PIN_ENTRY_FLAG : H5AC__NO_FLAGS_SET) < 0)
                     HGOTO_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, FAIL, "unable to release B-tree node")
 
+                /* Keep track of parent if necessary */
+                if(hdr->swmr_write)
+                    parent = internal;
+
                 /* Set pointer to next node to load */
                 curr_node_ptr = next_node_ptr;
             } /* end if */
@@ -675,9 +727,16 @@ H5B2_index(H5B2_t *bt2, hid_t dxpl_id, H5_iter_order_t order, hsize_t idx,
         H5B2_leaf_t *leaf;          /* Pointer to leaf node in B-tree */
 
         /* Lock B-tree leaf node */
-        if(NULL == (leaf = H5B2_protect_leaf(hdr, dxpl_id, curr_node_ptr.addr, curr_node_ptr.node_nrec, H5AC_READ)))
+        if(NULL == (leaf = H5B2_protect_leaf(hdr, dxpl_id, curr_node_ptr.addr, parent, curr_node_ptr.node_nrec, H5AC_READ)))
             HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree leaf node")
 
+        /* Unpin parent if necessary */
+        if(parent) {
+            if(parent != hdr && H5AC_unpin_entry(parent) < 0)
+                HGOTO_ERROR(H5E_BTREE, H5E_CANTUNPIN, FAIL, "unable to unpin parent entry")
+            parent = NULL;
+        } /* end if */
+
         /* Sanity check index */
         HDassert(idx < leaf->nrec);
 
@@ -696,6 +755,12 @@ H5B2_index(H5B2_t *bt2, hid_t dxpl_id, H5_iter_order_t order, hsize_t idx,
     } /* end block */
 
 done:
+    if(parent) {
+        HDassert(ret_value < 0);
+        if(parent != hdr && H5AC_unpin_entry(parent) < 0)
+            HDONE_ERROR(H5E_BTREE, H5E_CANTUNPIN, FAIL, "unable to unpin parent entry")
+    } /* end if */
+
     FUNC_LEAVE_NOAPI(ret_value)
 } /* H5B2_index() */
 
@@ -739,8 +804,9 @@ H5B2_remove(H5B2_t *bt2, hid_t dxpl_id, void *udata, H5B2_remove_t op,
     if(hdr->depth > 0) {
         hbool_t depth_decreased = FALSE;  /* Flag to indicate whether the depth of the B-tree decreased */
 
-        if(H5B2_remove_internal(hdr, dxpl_id, &depth_decreased, NULL, hdr->depth,
-                &(hdr->cache_info), NULL, &hdr->root, udata, op, op_data) < 0)
+        if(H5B2_remove_internal(hdr, dxpl_id, &depth_decreased, NULL, NULL,
+                hdr->depth, &(hdr->cache_info), NULL, &hdr->root, udata, op,
+                op_data) < 0)
             HGOTO_ERROR(H5E_BTREE, H5E_CANTDELETE, FAIL, "unable to remove record from B-tree internal node")
 
         /* Check for decreasing the depth of the B-tree */
@@ -758,7 +824,7 @@ H5B2_remove(H5B2_t *bt2, hid_t dxpl_id, void *udata, H5B2_remove_t op,
         } /* end for */
     } /* end if */
     else {
-        if(H5B2_remove_leaf(hdr, dxpl_id, &hdr->root, udata, op, op_data) < 0)
+        if(H5B2_remove_leaf(hdr, dxpl_id, &hdr->root, hdr, udata, op, op_data) < 0)
             HGOTO_ERROR(H5E_BTREE, H5E_CANTDELETE, FAIL, "unable to remove record from B-tree leaf node")
     } /* end else */
 
@@ -779,6 +845,12 @@ done:
  *
  * Purpose:	Removes the n'th record from a B-tree.
  *
+ *              The 'udata' parameter is only used to pass through to the
+ *              crt_flush_dep and upd_flush_dep callbacks, so it only
+ *              needs to contain enough information for those (if any - it
+ *              can be NULL).  Specifically, it does not need to identify
+ *              the specific record to search for.
+ *
  * Return:	Non-negative on success/Negative on failure
  *
  * Programmer:	Quincey Koziol
@@ -789,7 +861,7 @@ done:
  */
 herr_t
 H5B2_remove_by_idx(H5B2_t *bt2, hid_t dxpl_id, H5_iter_order_t order,
-    hsize_t idx, H5B2_remove_t op, void *op_data)
+    hsize_t idx, void *udata, H5B2_remove_t op, void *op_data)
 {
     H5B2_hdr_t	*hdr;                   /* Pointer to the B-tree header */
     herr_t	ret_value = SUCCEED;    /* Return value */
@@ -821,8 +893,9 @@ H5B2_remove_by_idx(H5B2_t *bt2, hid_t dxpl_id, H5_iter_order_t order,
     if(hdr->depth > 0) {
         hbool_t depth_decreased = FALSE;  /* Flag to indicate whether the depth of the B-tree decreased */
 
-        if(H5B2_remove_internal_by_idx(hdr, dxpl_id, &depth_decreased, NULL, hdr->depth,
-                &(hdr->cache_info), NULL, &hdr->root, idx, op, op_data) < 0)
+        if(H5B2_remove_internal_by_idx(hdr, dxpl_id, &depth_decreased, NULL,
+                NULL, hdr->depth, &(hdr->cache_info), NULL, &hdr->root, idx,
+                udata, op, op_data) < 0)
             HGOTO_ERROR(H5E_BTREE, H5E_CANTDELETE, FAIL, "unable to remove record from B-tree internal node")
 
         /* Check for decreasing the depth of the B-tree */
@@ -840,7 +913,7 @@ H5B2_remove_by_idx(H5B2_t *bt2, hid_t dxpl_id, H5_iter_order_t order,
         } /* end for */
     } /* end if */
     else {
-        if(H5B2_remove_leaf_by_idx(hdr, dxpl_id, &hdr->root, (unsigned)idx, op, op_data) < 0)
+        if(H5B2_remove_leaf_by_idx(hdr, dxpl_id, &hdr->root, hdr, (unsigned)idx, op, op_data) < 0)
             HGOTO_ERROR(H5E_BTREE, H5E_CANTDELETE, FAIL, "unable to remove record from B-tree leaf node")
     } /* end else */
 
@@ -935,11 +1008,11 @@ H5B2_neighbor(H5B2_t *bt2, hid_t dxpl_id, H5B2_compare_t range, void *udata,
 
     /* Attempt to find neighbor record in B-tree */
     if(hdr->depth > 0) {
-        if(H5B2_neighbor_internal(hdr, dxpl_id, hdr->depth, &hdr->root, NULL, range, udata, op, op_data) < 0)
+        if(H5B2_neighbor_internal(hdr, dxpl_id, hdr->depth, &hdr->root, NULL, range, hdr, udata, op, op_data) < 0)
             HGOTO_ERROR(H5E_BTREE, H5E_NOTFOUND, FAIL, "unable to find neighbor record in B-tree internal node")
     } /* end if */
     else {
-        if(H5B2_neighbor_leaf(hdr, dxpl_id, &hdr->root, NULL, range, udata, op, op_data) < 0)
+        if(H5B2_neighbor_leaf(hdr, dxpl_id, &hdr->root, NULL, range, hdr, udata, op, op_data) < 0)
             HGOTO_ERROR(H5E_BTREE, H5E_NOTFOUND, FAIL, "unable to find neighbor record in B-tree leaf node")
     } /* end else */
 
@@ -974,6 +1047,7 @@ H5B2_modify(H5B2_t *bt2, hid_t dxpl_id, void *udata, H5B2_modify_t op,
 {
     H5B2_hdr_t	*hdr;                   /* Pointer to the B-tree header */
     H5B2_node_ptr_t curr_node_ptr;      /* Node pointer info for current node */
+    void        *parent = NULL;         /* Parent of current node */
     unsigned    depth;                  /* Current depth of the tree */
     int         cmp;                    /* Comparison value of records */
     unsigned    idx;                    /* Location of record which matches key */
@@ -994,24 +1068,35 @@ H5B2_modify(H5B2_t *bt2, hid_t dxpl_id, void *udata, H5B2_modify_t op,
     /* Make copy of the root node pointer to start search with */
     curr_node_ptr = hdr->root;
 
-    /* Current depth of the tree */
-    depth = hdr->depth;
-
     /* Check for empty tree */
     if(0 == curr_node_ptr.node_nrec)
         HGOTO_ERROR(H5E_BTREE, H5E_NOTFOUND, FAIL, "B-tree has no records")
 
+    /* Current depth of the tree */
+    depth = hdr->depth;
+
+    /* Set initial parent, if doing swmr writes */
+    if(hdr->swmr_write)
+        parent = hdr;
+
     /* Walk down B-tree to find record or leaf node where record is located */
     cmp = -1;
-    while(depth > 0 && cmp != 0) {
+    while(depth > 0) {
         unsigned internal_flags = H5AC__NO_FLAGS_SET;
         H5B2_internal_t *internal;          /* Pointer to internal node in B-tree */
         H5B2_node_ptr_t next_node_ptr;      /* Node pointer info for next node */
 
         /* Lock B-tree current node */
-        if(NULL == (internal = H5B2_protect_internal(hdr, dxpl_id, curr_node_ptr.addr, curr_node_ptr.node_nrec, depth, H5AC_WRITE)))
+        if(NULL == (internal = H5B2_protect_internal(hdr, dxpl_id, curr_node_ptr.addr, parent, curr_node_ptr.node_nrec, depth, H5AC_WRITE)))
             HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to load B-tree internal node")
 
+        /* Unpin parent if necessary */
+        if(parent) {
+            if(parent != hdr && H5AC_unpin_entry(parent) < 0)
+                HGOTO_ERROR(H5E_BTREE, H5E_CANTUNPIN, FAIL, "unable to unpin parent entry")
+            parent = NULL;
+        } /* end if */
+
         /* Locate node pointer for child */
         cmp = H5B2_locate_record(hdr->cls, internal->nrec, hdr->nat_off, internal->int_native, udata, &idx);
         if(cmp > 0)
@@ -1022,9 +1107,13 @@ H5B2_modify(H5B2_t *bt2, hid_t dxpl_id, void *udata, H5B2_modify_t op,
             next_node_ptr = internal->node_ptrs[idx];
 
             /* Unlock current node */
-            if(H5AC_unprotect(hdr->f, dxpl_id, H5AC_BT2_INT, curr_node_ptr.addr, internal, H5AC__NO_FLAGS_SET) < 0)
+            if(H5AC_unprotect(hdr->f, dxpl_id, H5AC_BT2_INT, curr_node_ptr.addr, internal, hdr->swmr_write ? H5AC__PIN_ENTRY_FLAG : H5AC__NO_FLAGS_SET) < 0)
                 HGOTO_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, FAIL, "unable to release B-tree node")
 
+            /* Keep track of parent if necessary */
+            if(hdr->swmr_write)
+                parent = internal;
+
             /* Set pointer to next node to load */
             curr_node_ptr = next_node_ptr;
         } /* end if */
@@ -1063,9 +1152,16 @@ H5B2_modify(H5B2_t *bt2, hid_t dxpl_id, void *udata, H5B2_modify_t op,
         hbool_t changed = FALSE;/* Whether the 'modify' callback changed the record */
 
         /* Lock B-tree leaf node */
-        if(NULL == (leaf = H5B2_protect_leaf(hdr, dxpl_id, curr_node_ptr.addr, curr_node_ptr.node_nrec, H5AC_WRITE)))
+        if(NULL == (leaf = H5B2_protect_leaf(hdr, dxpl_id, curr_node_ptr.addr, parent, curr_node_ptr.node_nrec, H5AC_WRITE)))
             HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree leaf node")
 
+        /* Unpin parent if necessary */
+        if(parent) {
+            if(parent != hdr && H5AC_unpin_entry(parent) < 0)
+                HGOTO_ERROR(H5E_BTREE, H5E_CANTUNPIN, FAIL, "unable to unpin parent entry")
+            parent = NULL;
+        } /* end if */
+
         /* Locate record */
         cmp = H5B2_locate_record(hdr->cls, leaf->nrec, hdr->nat_off, leaf->leaf_native, udata, &idx);
 
@@ -1107,6 +1203,12 @@ H5B2_modify(H5B2_t *bt2, hid_t dxpl_id, void *udata, H5B2_modify_t op,
     }
 
 done:
+    if(parent) {
+        HDassert(ret_value < 0);
+        if(parent != hdr && H5AC_unpin_entry(parent) < 0)
+            HDONE_ERROR(H5E_BTREE, H5E_CANTUNPIN, FAIL, "unable to unpin parent entry")
+    } /* end if */
+
     FUNC_LEAVE_NOAPI(ret_value)
 } /* H5B2_modify() */
 
@@ -1235,7 +1337,7 @@ done:
  */
 herr_t
 H5B2_delete(H5F_t *f, hid_t dxpl_id, haddr_t addr, void *ctx_udata,
-    H5B2_remove_t op, void *op_data)
+    void *parent, H5B2_remove_t op, void *op_data)
 {
     H5B2_hdr_t	*hdr = NULL;            /* Pointer to the B-tree header */
     H5B2_hdr_cache_ud_t cache_udata;    /* User-data for callback */
@@ -1252,6 +1354,7 @@ H5B2_delete(H5F_t *f, hid_t dxpl_id, haddr_t addr, void *ctx_udata,
 HDfprintf(stderr, "%s: addr = %a\n", FUNC, addr);
 #endif /* QAK */
     cache_udata.f = f;
+    cache_udata.parent = parent;
     cache_udata.ctx_udata = ctx_udata;
     if(NULL == (hdr = (H5B2_hdr_t *)H5AC_protect(f, dxpl_id, H5AC_BT2_HDR, addr, &cache_udata, H5AC_WRITE)))
         HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect v2 B-tree header")
@@ -1281,3 +1384,293 @@ done:
     FUNC_LEAVE_NOAPI(ret_value)
 } /* H5B2_delete() */
 
+
+/*-------------------------------------------------------------------------
+ * Function:    H5B2_support
+ *
+ * Purpose:     Add a flush dependency between the b-tree child object (as
+ *              the flush dependency child) and the b-tree node containing
+ *              the address of that child.  If the child has not yet been
+ *              inserted, does nothing.
+ *
+ * Return:      TRUE if flush dependency created
+ *              FALSE if child is not in b-tree
+ *              Negative on failure
+ *
+ * Programmer:  Neil Fortner
+ *              May 11 2012
+ *
+ *-------------------------------------------------------------------------
+ */
+htri_t
+H5B2_support(H5B2_t *bt2, hid_t dxpl_id, void *udata, void *child)
+{
+    H5B2_hdr_t  *hdr;                   /* Pointer to the B-tree header */
+    H5B2_node_ptr_t curr_node_ptr;      /* Node pointer info for current node */
+    void        *parent = NULL;         /* Parent of current node */
+    unsigned    depth;                  /* Current depth of the tree */
+    int         cmp;                    /* Comparison value of records */
+    unsigned    idx;                    /* Location of record which matches key */
+    htri_t      ret_value = FALSE;      /* Return value */
+
+    FUNC_ENTER_NOAPI(FAIL)
+
+    /* Check arguments. */
+    HDassert(bt2);
+    HDassert(child);
+
+    /* Set the shared v2 B-tree header's file context for this operation */
+    bt2->hdr->f = bt2->f;
+
+    /* Get the v2 B-tree header */
+    hdr = bt2->hdr;
+
+    /* Make copy of the root node pointer to start search with */
+    curr_node_ptr = hdr->root;
+
+    /* Check for empty tree */
+    if(curr_node_ptr.node_nrec == 0)
+        HGOTO_DONE(FALSE)
+
+    /* Current depth of the tree */
+    depth = hdr->depth;
+
+    /* This should only be called if swmr_write is on */
+    HDassert(hdr->swmr_write);
+
+    /* Set initial parent */
+    parent = hdr;
+
+    /* Walk down B-tree to find record or leaf node where record is located */
+    while(depth > 0) {
+        H5B2_internal_t *internal;          /* Pointer to internal node in B-tree */
+        H5B2_node_ptr_t next_node_ptr;      /* Node pointer info for next node */
+
+        /* Lock B-tree current node */
+        if(NULL == (internal = H5B2_protect_internal(hdr, dxpl_id, curr_node_ptr.addr, parent, curr_node_ptr.node_nrec, depth, H5AC_READ)))
+            HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to load B-tree internal node")
+
+        /* Unpin parent if necessary */
+        if(parent != hdr && H5AC_unpin_entry(parent) < 0)
+            HGOTO_ERROR(H5E_BTREE, H5E_CANTUNPIN, FAIL, "unable to unpin parent entry")
+        parent = NULL;
+
+        /* Locate node pointer for child */
+        cmp = H5B2_locate_record(hdr->cls, internal->nrec, hdr->nat_off, internal->int_native, udata, &idx);
+        if(cmp > 0)
+            idx++;
+
+        if(cmp != 0) {
+            /* Get node pointer for next node to search */
+            next_node_ptr=internal->node_ptrs[idx];
+
+            /* Unlock current node */
+            if(H5AC_unprotect(hdr->f, dxpl_id, H5AC_BT2_INT, curr_node_ptr.addr, internal, H5AC__PIN_ENTRY_FLAG) < 0)
+                HGOTO_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, FAIL, "unable to release B-tree node")
+
+            /* Keep track of parent */
+            parent = internal;
+
+            /* Set pointer to next node to load */
+            curr_node_ptr = next_node_ptr;
+        } /* end if */
+        else {
+            /* Add flush dependency on child */
+            if(H5AC_create_flush_dependency(internal, child) < 0)
+                HGOTO_ERROR(H5E_BTREE, H5E_CANTDEPEND, FAIL, "unable to create flush dependency")
+
+            /* Unlock current node */
+            if(H5AC_unprotect(hdr->f, dxpl_id, H5AC_BT2_INT, curr_node_ptr.addr, internal, H5AC__NO_FLAGS_SET) < 0)
+                HGOTO_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, FAIL, "unable to release B-tree node")
+
+            /* Indicate record supported */
+            HGOTO_DONE(TRUE)
+        } /* end else */
+
+        /* Decrement depth we're at in B-tree */
+        depth--;
+    } /* end while */
+
+    {
+        H5B2_leaf_t *leaf;          /* Pointer to leaf node in B-tree */
+
+        /* Lock B-tree leaf node */
+        if(NULL == (leaf = H5B2_protect_leaf(hdr, dxpl_id, curr_node_ptr.addr, parent, curr_node_ptr.node_nrec, H5AC_READ)))
+            HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree leaf node")
+
+        /* Unpin parent if necessary */
+        if(parent != hdr && H5AC_unpin_entry(parent) < 0)
+            HGOTO_ERROR(H5E_BTREE, H5E_CANTUNPIN, FAIL, "unable to unpin parent entry")
+        parent = NULL;
+
+        /* Locate record */
+        cmp = H5B2_locate_record(hdr->cls, leaf->nrec, hdr->nat_off, leaf->leaf_native, udata, &idx);
+
+        if(cmp == 0) {
+            /* Add flush dependency on child */
+            if(H5AC_create_flush_dependency(leaf, child) < 0)
+                HGOTO_ERROR(H5E_BTREE, H5E_CANTDEPEND, FAIL, "unable to create flush dependency")
+
+            /* Indicate child was supported */
+            ret_value = TRUE;
+        } /* end if */
+
+        /* Unlock current node */
+        if(H5AC_unprotect(hdr->f, dxpl_id, H5AC_BT2_LEAF, curr_node_ptr.addr, leaf, H5AC__NO_FLAGS_SET) < 0)
+            HGOTO_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, FAIL, "unable to release B-tree node")
+    } /* end block */
+
+done:
+    if(parent) {
+        HDassert(ret_value < 0);
+        if(parent != hdr && H5AC_unpin_entry(parent) < 0)
+            HDONE_ERROR(H5E_BTREE, H5E_CANTUNPIN, FAIL, "unable to unpin parent entry")
+    } /* end if */
+
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5B2_support() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5B2_unsupport
+ *
+ * Purpose:     Destroy a flush dependency between the b-tree child object
+ *              and the b-tree node containing the address of that child.
+ *              This dependency *must* have been created earlier either by
+ *              a call to H5B_support() or by the client (presumably via
+ *              the create_flush_dep() callback on insertion).
+ *
+ * Return:      Non-negative on success/Negative on failure
+ *
+ * Programmer:  Neil Fortner
+ *              May 14 2012
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5B2_unsupport(H5B2_t *bt2, hid_t dxpl_id, void *udata, void *child)
+{
+    H5B2_hdr_t  *hdr;                   /* Pointer to the B-tree header */
+    H5B2_node_ptr_t curr_node_ptr;      /* Node pointer info for current node */
+    void        *parent = NULL;         /* Parent of current node */
+    unsigned    depth;                  /* Current depth of the tree */
+    int         cmp;                    /* Comparison value of records */
+    unsigned    idx;                    /* Location of record which matches key */
+    htri_t      ret_value = SUCCEED;    /* Return value */
+
+    FUNC_ENTER_NOAPI(FAIL)
+
+    /* Check arguments. */
+    HDassert(bt2);
+    HDassert(child);
+
+    /* Set the shared v2 B-tree header's file context for this operation */
+    bt2->hdr->f = bt2->f;
+
+    /* Get the v2 B-tree header */
+    hdr = bt2->hdr;
+
+    /* Make copy of the root node pointer to start search with */
+    curr_node_ptr = hdr->root;
+
+    /* Check for empty tree */
+    if(curr_node_ptr.node_nrec == 0)
+        HGOTO_ERROR(H5E_BTREE, H5E_NOTFOUND, FAIL, "B-tree is empty")
+
+    /* Current depth of the tree */
+    depth = hdr->depth;
+
+    /* This should only be called if swmr_write is on */
+    HDassert(hdr->swmr_write);
+
+    /* Set initial parent */
+    parent = hdr;
+
+    /* Walk down B-tree to find record or leaf node where record is located */
+    while(depth > 0) {
+        H5B2_internal_t *internal;          /* Pointer to internal node in B-tree */
+        H5B2_node_ptr_t next_node_ptr;      /* Node pointer info for next node */
+
+        /* Lock B-tree current node */
+        if(NULL == (internal = H5B2_protect_internal(hdr, dxpl_id, curr_node_ptr.addr, parent, curr_node_ptr.node_nrec, depth, H5AC_READ)))
+            HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to load B-tree internal node")
+
+        /* Unpin parent if necessary */
+        if(parent != hdr && H5AC_unpin_entry(parent) < 0)
+            HGOTO_ERROR(H5E_BTREE, H5E_CANTUNPIN, FAIL, "unable to unpin parent entry")
+        parent = NULL;
+
+        /* Locate node pointer for child */
+        cmp = H5B2_locate_record(hdr->cls, internal->nrec, hdr->nat_off, internal->int_native, udata, &idx);
+        if(cmp > 0)
+            idx++;
+
+        if(cmp != 0) {
+            /* Get node pointer for next node to search */
+            next_node_ptr=internal->node_ptrs[idx];
+
+            /* Unlock current node */
+            if(H5AC_unprotect(hdr->f, dxpl_id, H5AC_BT2_INT, curr_node_ptr.addr, internal, H5AC__PIN_ENTRY_FLAG) < 0)
+                HGOTO_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, FAIL, "unable to release B-tree node")
+
+            /* Keep track of parent */
+            parent = internal;
+
+            /* Set pointer to next node to load */
+            curr_node_ptr = next_node_ptr;
+        } /* end if */
+        else {
+            /* Remove flush dependency on child */
+            if(H5AC_destroy_flush_dependency(internal, child) < 0)
+                HGOTO_ERROR(H5E_BTREE, H5E_CANTDEPEND, FAIL, "unable to create flush dependency")
+
+            /* Unlock current node */
+            if(H5AC_unprotect(hdr->f, dxpl_id, H5AC_BT2_INT, curr_node_ptr.addr, internal, H5AC__NO_FLAGS_SET) < 0)
+                HGOTO_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, FAIL, "unable to release B-tree node")
+
+            /* No need to continue */
+            HGOTO_DONE(SUCCEED)
+        } /* end else */
+
+        /* Decrement depth we're at in B-tree */
+        depth--;
+    } /* end while */
+
+    {
+        H5B2_leaf_t *leaf;          /* Pointer to leaf node in B-tree */
+
+        /* Lock B-tree leaf node */
+        if(NULL == (leaf = H5B2_protect_leaf(hdr, dxpl_id, curr_node_ptr.addr, parent, curr_node_ptr.node_nrec, H5AC_READ)))
+            HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree leaf node")
+
+        /* Unpin parent if necessary */
+        if(parent != hdr && H5AC_unpin_entry(parent) < 0)
+            HGOTO_ERROR(H5E_BTREE, H5E_CANTUNPIN, FAIL, "unable to unpin parent entry")
+        parent = NULL;
+
+        /* Locate record */
+        cmp = H5B2_locate_record(hdr->cls, leaf->nrec, hdr->nat_off, leaf->leaf_native, udata, &idx);
+
+        if(cmp == 0) {
+            /* Add flush dependency on child */
+            if(H5AC_destroy_flush_dependency(leaf, child) < 0)
+                HGOTO_ERROR(H5E_BTREE, H5E_CANTDEPEND, FAIL, "unable to create flush dependency")
+        } /* end if */
+        else
+            HGOTO_ERROR(H5E_BTREE, H5E_NOTFOUND, FAIL, "node not found in B-tree")
+
+        /* Unlock current node */
+        if(H5AC_unprotect(hdr->f, dxpl_id, H5AC_BT2_LEAF, curr_node_ptr.addr, leaf, H5AC__NO_FLAGS_SET) < 0)
+            HGOTO_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, FAIL, "unable to release B-tree node")
+    } /* end block */
+
+done:
+    if(parent) {
+        HDassert(ret_value < 0);
+        if(parent != hdr && H5AC_unpin_entry(parent) < 0)
+            HDONE_ERROR(H5E_BTREE, H5E_CANTUNPIN, FAIL, "unable to unpin parent entry")
+    } /* end if */
+
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5B2_unsupport() */
+
diff --git a/src/H5B2cache.c b/src/H5B2cache.c
index 2ee4ef7..96faa13 100644
--- a/src/H5B2cache.c
+++ b/src/H5B2cache.c
@@ -73,16 +73,19 @@ static H5B2_hdr_t *H5B2_cache_hdr_load(H5F_t *f, hid_t dxpl_id, haddr_t addr, vo
 static herr_t H5B2_cache_hdr_flush(H5F_t *f, hid_t dxpl_id, hbool_t destroy, haddr_t addr, H5B2_hdr_t *hdr, unsigned UNUSED * flags_ptr);
 static herr_t H5B2_cache_hdr_dest(H5F_t *f, H5B2_hdr_t *hdr);
 static herr_t H5B2_cache_hdr_clear(H5F_t *f, H5B2_hdr_t *hdr, hbool_t destroy);
+static herr_t H5B2_cache_hdr_notify(H5AC_notify_action_t action, H5B2_hdr_t *hdr);
 static herr_t H5B2_cache_hdr_size(const H5F_t *f, const H5B2_hdr_t *hdr, size_t *size_ptr);
 static H5B2_internal_t *H5B2_cache_internal_load(H5F_t *f, hid_t dxpl_id, haddr_t addr, void *udata);
 static herr_t H5B2_cache_internal_flush(H5F_t *f, hid_t dxpl_id, hbool_t destroy, haddr_t addr, H5B2_internal_t *i, unsigned UNUSED * flags_ptr);
 static herr_t H5B2_cache_internal_dest(H5F_t *f, H5B2_internal_t *internal);
 static herr_t H5B2_cache_internal_clear(H5F_t *f, H5B2_internal_t *i, hbool_t destroy);
+static herr_t H5B2_cache_internal_notify(H5AC_notify_action_t action, H5B2_internal_t *internal);
 static herr_t H5B2_cache_internal_size(const H5F_t *f, const H5B2_internal_t *i, size_t *size_ptr);
 static H5B2_leaf_t *H5B2_cache_leaf_load(H5F_t *f, hid_t dxpl_id, haddr_t addr, void *udata);
 static herr_t H5B2_cache_leaf_flush(H5F_t *f, hid_t dxpl_id, hbool_t destroy, haddr_t addr, H5B2_leaf_t *l, unsigned UNUSED * flags_ptr);
 static herr_t H5B2_cache_leaf_dest(H5F_t *f, H5B2_leaf_t *leaf);
 static herr_t H5B2_cache_leaf_clear(H5F_t *f, H5B2_leaf_t *l, hbool_t destroy);
+static herr_t H5B2_cache_leaf_notify(H5AC_notify_action_t action, H5B2_leaf_t *leaf);
 static herr_t H5B2_cache_leaf_size(const H5F_t *f, const H5B2_leaf_t *l, size_t *size_ptr);
 
 
@@ -97,7 +100,7 @@ const H5AC_class_t H5AC_BT2_HDR[1] = {{
     (H5AC_flush_func_t)H5B2_cache_hdr_flush,
     (H5AC_dest_func_t)H5B2_cache_hdr_dest,
     (H5AC_clear_func_t)H5B2_cache_hdr_clear,
-    (H5AC_notify_func_t)NULL,
+    (H5AC_notify_func_t)H5B2_cache_hdr_notify,
     (H5AC_size_func_t)H5B2_cache_hdr_size,
 }};
 
@@ -108,7 +111,7 @@ const H5AC_class_t H5AC_BT2_INT[1] = {{
     (H5AC_flush_func_t)H5B2_cache_internal_flush,
     (H5AC_dest_func_t)H5B2_cache_internal_dest,
     (H5AC_clear_func_t)H5B2_cache_internal_clear,
-    (H5AC_notify_func_t)NULL,
+    (H5AC_notify_func_t)H5B2_cache_internal_notify,
     (H5AC_size_func_t)H5B2_cache_internal_size,
 }};
 
@@ -119,7 +122,7 @@ const H5AC_class_t H5AC_BT2_LEAF[1] = {{
     (H5AC_flush_func_t)H5B2_cache_leaf_flush,
     (H5AC_dest_func_t)H5B2_cache_leaf_dest,
     (H5AC_clear_func_t)H5B2_cache_leaf_clear,
-    (H5AC_notify_func_t)NULL,
+    (H5AC_notify_func_t)H5B2_cache_leaf_notify,
     (H5AC_size_func_t)H5B2_cache_leaf_size,
 }};
 
@@ -238,7 +241,7 @@ H5B2_cache_hdr_load(H5F_t *f, hid_t dxpl_id, haddr_t addr, void *_udata)
 
     /* Initialize B-tree header info */
     cparam.cls = H5B2_client_class_g[id];
-    if(H5B2_hdr_init(hdr, &cparam, udata->ctx_udata, depth) < 0)
+    if(H5B2_hdr_init(hdr, &cparam, udata->ctx_udata, udata->parent, depth) < 0)
 	HGOTO_ERROR(H5E_BTREE, H5E_CANTINIT, NULL, "can't initialize B-tree header info")
 
     /* Set the B-tree header's address */
@@ -348,6 +351,23 @@ H5B2_cache_hdr_flush(H5F_t *f, hid_t dxpl_id, hbool_t destroy, haddr_t addr,
 	    HGOTO_ERROR(H5E_BTREE, H5E_CANTFLUSH, FAIL, "unable to save B-tree header to disk")
 
 	hdr->cache_info.is_dirty = FALSE;
+
+	/* Clear shadowed node lists, as the header has been flushed and all
+	 * nodes must be shadowed again (if doing SWMR writes).  Note that this
+	 * algorithm does one extra iteration at the end, as the last node's
+	 * shadowed_next pointer points to itself. */
+	while(hdr->shadowed_internal) {
+            H5B2_internal_t *next = hdr->shadowed_internal->shadowed_next;
+
+            hdr->shadowed_internal->shadowed_next = NULL;
+            hdr->shadowed_internal = next;
+        } /* end while */
+        while(hdr->shadowed_leaf) {
+            H5B2_leaf_t *next = hdr->shadowed_leaf->shadowed_next;
+
+            hdr->shadowed_leaf->shadowed_next = NULL;
+            hdr->shadowed_leaf = next;
+        } /* end while */
     } /* end if */
 
     if(destroy)
@@ -445,6 +465,61 @@ done:
 
 
 /*-------------------------------------------------------------------------
+ * Function:    H5B2_cache_hdr_notify
+ *
+ * Purpose:     Handle cache action notifications
+ *
+ * Return:      Non-negative on success/Negative on failure
+ *
+ * Programmer:  Neil Fortner
+ *              nfortne2@hdfgroup.org
+ *              Apr 24 2012
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5B2_cache_hdr_notify(H5AC_notify_action_t action, H5B2_hdr_t *hdr)
+{
+    herr_t              ret_value = SUCCEED;
+
+    FUNC_ENTER_NOAPI_NOINIT
+
+    /*
+     * Check arguments.
+     */
+    HDassert(hdr);
+
+    /* Check if the file was opened with SWMR-write access */
+    if(hdr->swmr_write) {
+        HDassert(hdr->parent);
+        switch(action) {
+            case H5AC_NOTIFY_ACTION_AFTER_INSERT:
+                /* Create flush dependency on parent */
+                if(H5AC_create_flush_dependency(hdr->parent, hdr) < 0)
+                    HGOTO_ERROR(H5E_BTREE, H5E_CANTDEPEND, FAIL, "unable to create flush dependency")
+                break;
+
+            case H5AC_NOTIFY_ACTION_BEFORE_EVICT:
+                /* Destroy flush dependency on parent */
+                if(H5AC_destroy_flush_dependency(hdr->parent, hdr) < 0)
+                    HGOTO_ERROR(H5E_BTREE, H5E_CANTUNDEPEND, FAIL, "unable to destroy flush dependency")
+                break;
+
+            default:
+#ifdef NDEBUG
+                HGOTO_ERROR(H5E_BTREE, H5E_BADVALUE, FAIL, "unknown action from metadata cache")
+#else /* NDEBUG */
+                HDassert(0 && "Unknown action?!?");
+#endif /* NDEBUG */
+        } /* end switch */
+    } /* end if */
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5B2_cache_hdr_notify() */
+
+
+/*-------------------------------------------------------------------------
  * Function:	H5B2_cache_hdr_size
  *
  * Purpose:	Compute the size in bytes of a B-tree header
@@ -523,6 +598,7 @@ H5B2_cache_internal_load(H5F_t *f, hid_t dxpl_id, haddr_t addr, void *_udata)
 
     /* Share B-tree information */
     internal->hdr = udata->hdr;
+    internal->parent = udata->parent;
 
     /* Read header from disk */
     if(H5F_block_read(f, H5FD_MEM_BTREE, addr, udata->hdr->node_size, dxpl_id, udata->hdr->page) < 0)
@@ -787,6 +863,61 @@ done:
 
 
 /*-------------------------------------------------------------------------
+ * Function:    H5B2_cache_internal_notify
+ *
+ * Purpose:     Handle cache action notifications
+ *
+ * Return:      Non-negative on success/Negative on failure
+ *
+ * Programmer:  Neil Fortner
+ *              nfortne2@hdfgroup.org
+ *              Apr 25 2012
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5B2_cache_internal_notify(H5AC_notify_action_t action, H5B2_internal_t *internal)
+{
+    herr_t              ret_value = SUCCEED;
+
+    FUNC_ENTER_NOAPI_NOINIT
+
+    /*
+     * Check arguments.
+     */
+    HDassert(internal);
+
+    /* Check if the file was opened with SWMR-write access */
+    if(internal->hdr->swmr_write) {
+        HDassert(internal->parent);
+        switch(action) {
+            case H5AC_NOTIFY_ACTION_AFTER_INSERT:
+                /* Create flush dependency on parent */
+                if(H5AC_create_flush_dependency(internal->parent, internal) < 0)
+                    HGOTO_ERROR(H5E_BTREE, H5E_CANTDEPEND, FAIL, "unable to create flush dependency")
+                break;
+
+            case H5AC_NOTIFY_ACTION_BEFORE_EVICT:
+                /* Destroy flush dependency on parent */
+                if(H5AC_destroy_flush_dependency(internal->parent, internal) < 0)
+                    HGOTO_ERROR(H5E_BTREE, H5E_CANTUNDEPEND, FAIL, "unable to destroy flush dependency")
+                break;
+
+            default:
+#ifdef NDEBUG
+                HGOTO_ERROR(H5E_BTREE, H5E_BADVALUE, FAIL, "unknown action from metadata cache")
+#else /* NDEBUG */
+                HDassert(0 && "Unknown action?!?");
+#endif /* NDEBUG */
+        } /* end switch */
+    } /* end if */
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5B2_cache_internal_notify() */
+
+
+/*-------------------------------------------------------------------------
  * Function:	H5B2_cache_internal_size
  *
  * Purpose:	Compute the size in bytes of a B-tree internal node
@@ -865,6 +996,7 @@ H5B2_cache_leaf_load(H5F_t UNUSED *f, hid_t dxpl_id, haddr_t addr, void *_udata)
 
     /* Share B-tree header information */
     leaf->hdr = udata->hdr;
+    leaf->parent = udata->parent;
 
     /* Read header from disk */
     if(H5F_block_read(udata->f, H5FD_MEM_BTREE, addr, udata->hdr->node_size, dxpl_id, udata->hdr->page) < 0)
@@ -1095,6 +1227,61 @@ done:
 
 
 /*-------------------------------------------------------------------------
+ * Function:    H5B2_cache_leaf_notify
+ *
+ * Purpose:     Handle cache action notifications
+ *
+ * Return:      Non-negative on success/Negative on failure
+ *
+ * Programmer:  Neil Fortner
+ *              nfortne2@hdfgroup.org
+ *              Apr 25 2012
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5B2_cache_leaf_notify(H5AC_notify_action_t action, H5B2_leaf_t *leaf)
+{
+    herr_t              ret_value = SUCCEED;
+
+    FUNC_ENTER_NOAPI_NOINIT
+
+    /*
+     * Check arguments.
+     */
+    HDassert(leaf);
+
+    /* Check if the file was opened with SWMR-write access */
+    if(leaf->hdr->swmr_write) {
+        HDassert(leaf->parent);
+        switch(action) {
+            case H5AC_NOTIFY_ACTION_AFTER_INSERT:
+                /* Create flush dependency on parent */
+                if(H5AC_create_flush_dependency(leaf->parent, leaf) < 0)
+                    HGOTO_ERROR(H5E_BTREE, H5E_CANTDEPEND, FAIL, "unable to create flush dependency")
+                break;
+
+            case H5AC_NOTIFY_ACTION_BEFORE_EVICT:
+                /* Destroy flush dependency on parent */
+                if(H5AC_destroy_flush_dependency(leaf->parent, leaf) < 0)
+                    HGOTO_ERROR(H5E_BTREE, H5E_CANTUNDEPEND, FAIL, "unable to destroy flush dependency")
+                break;
+
+            default:
+#ifdef NDEBUG
+                HGOTO_ERROR(H5E_BTREE, H5E_BADVALUE, FAIL, "unknown action from metadata cache")
+#else /* NDEBUG */
+                HDassert(0 && "Unknown action?!?");
+#endif /* NDEBUG */
+        } /* end switch */
+    } /* end if */
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5B2_cache_leaf_notify() */
+
+
+/*-------------------------------------------------------------------------
  * Function:	H5B2_cache_leaf_size
  *
  * Purpose:	Compute the size in bytes of a B-tree leaf node
diff --git a/src/H5B2dbg.c b/src/H5B2dbg.c
index 3e5d55a..06c1195 100644
--- a/src/H5B2dbg.c
+++ b/src/H5B2dbg.c
@@ -124,6 +124,7 @@ H5B2_hdr_debug(H5F_t *f, hid_t dxpl_id, haddr_t addr, FILE *stream, int indent,
      */
     cache_udata.f = f;
     cache_udata.ctx_udata = dbg_ctx;
+    cache_udata.parent = NULL;
     if(NULL == (hdr = (H5B2_hdr_t *)H5AC_protect(f, dxpl_id, H5AC_BT2_HDR, addr, &cache_udata, H5AC_READ)))
 	HGOTO_ERROR(H5E_BTREE, H5E_CANTLOAD, FAIL, "unable to load B-tree header")
 
@@ -242,6 +243,7 @@ H5B2_int_debug(H5F_t *f, hid_t dxpl_id, haddr_t addr, FILE *stream, int indent,
      */
     cache_udata.f = f;
     cache_udata.ctx_udata = dbg_ctx;
+    cache_udata.parent = NULL;
     if(NULL == (hdr = (H5B2_hdr_t *)H5AC_protect(f, dxpl_id, H5AC_BT2_HDR, hdr_addr, &cache_udata, H5AC_READ)))
 	HGOTO_ERROR(H5E_BTREE, H5E_CANTLOAD, FAIL, "unable to load B-tree header")
 
@@ -251,7 +253,7 @@ H5B2_int_debug(H5F_t *f, hid_t dxpl_id, haddr_t addr, FILE *stream, int indent,
     /*
      * Load the B-tree internal node
      */
-    if(NULL == (internal = H5B2_protect_internal(hdr, dxpl_id, addr, nrec, depth, H5AC_READ)))
+    if(NULL == (internal = H5B2_protect_internal(hdr, dxpl_id, addr, NULL, nrec, depth, H5AC_READ)))
 	HGOTO_ERROR(H5E_BTREE, H5E_CANTLOAD, FAIL, "unable to load B-tree internal node")
 
     /* Print opening message */
@@ -374,6 +376,7 @@ H5B2_leaf_debug(H5F_t *f, hid_t dxpl_id, haddr_t addr, FILE *stream, int indent,
      */
     cache_udata.f = f;
     cache_udata.ctx_udata = dbg_ctx;
+    cache_udata.parent = NULL;
     if(NULL == (hdr = (H5B2_hdr_t *)H5AC_protect(f, dxpl_id, H5AC_BT2_HDR, hdr_addr, &cache_udata, H5AC_READ)))
 	HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree header")
 
@@ -383,7 +386,7 @@ H5B2_leaf_debug(H5F_t *f, hid_t dxpl_id, haddr_t addr, FILE *stream, int indent,
     /*
      * Load the B-tree leaf node
      */
-    if(NULL == (leaf = H5B2_protect_leaf(hdr, dxpl_id, addr, nrec, H5AC_READ)))
+    if(NULL == (leaf = H5B2_protect_leaf(hdr, dxpl_id, addr, NULL, nrec, H5AC_READ)))
 	HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree leaf node")
 
     /* Print opening message */
diff --git a/src/H5B2hdr.c b/src/H5B2hdr.c
index b73c29a..54842ff 100644
--- a/src/H5B2hdr.c
+++ b/src/H5B2hdr.c
@@ -108,7 +108,7 @@ H5FL_SEQ_DEFINE(H5B2_node_info_t);
  */
 herr_t
 H5B2_hdr_init(H5B2_hdr_t *hdr, const H5B2_create_t *cparam, void *ctx_udata,
-    uint16_t depth)
+    void *parent, uint16_t depth)
 {
     size_t sz_max_nrec;                 /* Temporary variable for range checking */
     unsigned u_max_nrec_size;           /* Temporary variable for range checking */
@@ -132,6 +132,7 @@ H5B2_hdr_init(H5B2_hdr_t *hdr, const H5B2_create_t *cparam, void *ctx_udata,
     HDassert(cparam->merge_percent < (cparam->split_percent / 2));
 
     /* Initialize basic information */
+    hdr->parent = parent;
     hdr->rc = 0;
     hdr->pending_delete = FALSE;
 
@@ -207,6 +208,12 @@ HDmemset(hdr->page, 0, hdr->node_size);
         } /* end for */
     } /* end if */
 
+    /* Determine if we are doing SWMR writes.  Only enable for data chunks for
+     * now. */
+    hdr->swmr_write = (H5F_INTENT(hdr->f) & H5F_ACC_SWMR_WRITE) > 0
+            && (hdr->cls->id == H5B2_CDSET_ID
+            || hdr->cls->id == H5B2_CDSET_FILT_ID);
+
     /* Create the callback context, if the callback exists */
     if(hdr->cls->crt_context) {
         if(NULL == (hdr->cb_ctx = (*hdr->cls->crt_context)(ctx_udata)))
@@ -283,7 +290,7 @@ done:
  */
 haddr_t
 H5B2_hdr_create(H5F_t *f, hid_t dxpl_id, const H5B2_create_t *cparam,
-    void *ctx_udata)
+    void *ctx_udata, void *parent)
 {
     H5B2_hdr_t *hdr = NULL;     /* The new v2 B-tree header information */
     haddr_t ret_value;          /* Return value */
@@ -301,7 +308,7 @@ H5B2_hdr_create(H5F_t *f, hid_t dxpl_id, const H5B2_create_t *cparam,
 	HGOTO_ERROR(H5E_BTREE, H5E_CANTALLOC, HADDR_UNDEF, "allocation failed for B-tree header")
 
     /* Initialize shared B-tree info */
-    if(H5B2_hdr_init(hdr, cparam, ctx_udata, (uint16_t)0) < 0)
+    if(H5B2_hdr_init(hdr, cparam, ctx_udata, parent, (uint16_t)0) < 0)
 	HGOTO_ERROR(H5E_BTREE, H5E_CANTINIT, HADDR_UNDEF, "can't create shared B-tree info")
 
     /* Allocate space for the header on disk */
@@ -590,7 +597,7 @@ H5B2_hdr_delete(H5B2_hdr_t *hdr, hid_t dxpl_id)
 
     /* Delete all nodes in B-tree */
     if(H5F_addr_defined(hdr->root.addr))
-        if(H5B2_delete_node(hdr, dxpl_id, hdr->depth, &hdr->root, hdr->remove_op, hdr->remove_op_data) < 0)
+        if(H5B2_delete_node(hdr, dxpl_id, hdr->depth, &hdr->root, hdr, hdr->remove_op, hdr->remove_op_data) < 0)
             HGOTO_ERROR(H5E_BTREE, H5E_CANTDELETE, FAIL, "unable to delete B-tree nodes")
 
     /* Indicate that the heap header should be deleted & file space freed */
diff --git a/src/H5B2int.c b/src/H5B2int.c
index 4355174..e6d359a 100644
--- a/src/H5B2int.c
+++ b/src/H5B2int.c
@@ -61,24 +61,32 @@
 /********************/
 
 /* Helper functions */
-static herr_t H5B2_create_internal(H5B2_hdr_t *hdr, hid_t dxpl_id,
+static herr_t H5B2_create_internal(H5B2_hdr_t *hdr, hid_t dxpl_id, void *parent,
     H5B2_node_ptr_t *node_ptr, unsigned depth);
 static herr_t H5B2_split1(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth,
     H5B2_node_ptr_t *curr_node_ptr, unsigned *parent_cache_info_flags_ptr,
-    H5B2_internal_t *internal, unsigned *internal_flags_ptr, unsigned idx);
+    H5B2_internal_t *internal, unsigned *internal_flags_ptr, unsigned idx,
+    void *udata);
 static herr_t H5B2_redistribute2(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth,
-    H5B2_internal_t *internal, unsigned idx);
+    H5B2_internal_t *internal, unsigned idx, void *udata);
 static herr_t H5B2_redistribute3(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth,
-    H5B2_internal_t *internal, unsigned *internal_flags_ptr, unsigned idx);
+    H5B2_internal_t *internal, unsigned *internal_flags_ptr, unsigned idx,
+    void *udata);
 static herr_t H5B2_merge2(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth,
     H5B2_node_ptr_t *curr_node_ptr, unsigned *parent_cache_info_flags_ptr,
-    H5B2_internal_t *internal, unsigned *internal_flags_ptr, unsigned idx);
+    H5B2_internal_t *internal, unsigned *internal_flags_ptr, unsigned idx,
+    void *udata);
 static herr_t H5B2_merge3(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth,
     H5B2_node_ptr_t *curr_node_ptr, unsigned *parent_cache_info_flags_ptr,
-    H5B2_internal_t *internal, unsigned *internal_flags_ptr, unsigned idx);
+    H5B2_internal_t *internal, unsigned *internal_flags_ptr, unsigned idx,
+    void *udata);
 static herr_t H5B2_swap_leaf(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth,
-    H5B2_internal_t *internal, unsigned *internal_flags_ptr,
-    unsigned idx, void *swap_loc);
+    H5B2_internal_t *internal, unsigned *internal_flags_ptr, unsigned idx,
+    void *swap_loc, void *swap_parent, void *udata);
+static herr_t H5B2_shadow_internal(H5B2_hdr_t *hdr, hid_t dxpl_id,
+    unsigned depth, H5B2_node_ptr_t *curr_node_ptr, H5B2_internal_t **internal);
+static herr_t H5B2_shadow_leaf(H5B2_hdr_t *hdr, hid_t dxpl_id,
+    H5B2_node_ptr_t *curr_node_ptr, H5B2_leaf_t **leaf);
 #ifdef H5B2_DEBUG
 static herr_t H5B2_assert_leaf(const H5B2_hdr_t *hdr, const H5B2_leaf_t *leaf);
 static herr_t H5B2_assert_leaf2(const H5B2_hdr_t *hdr, const H5B2_leaf_t *leaf, const H5B2_leaf_t *leaf2);
@@ -172,19 +180,24 @@ H5B2_locate_record(const H5B2_class_t *type, unsigned nrec, size_t *rec_off,
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5B2_split1(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth, H5B2_node_ptr_t *curr_node_ptr,
-    unsigned *parent_cache_info_flags_ptr, H5B2_internal_t *internal,
-    unsigned *internal_flags_ptr, unsigned idx)
+H5B2_split1(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth,
+    H5B2_node_ptr_t *curr_node_ptr, unsigned *parent_cache_info_flags_ptr,
+    H5B2_internal_t *internal, unsigned *internal_flags_ptr, unsigned idx,
+    void *udata)
 {
     const H5AC_class_t *child_class;    /* Pointer to child node's class info */
     haddr_t left_addr, right_addr;      /* Addresses of left & right child nodes */
     void *left_child = NULL, *right_child = NULL;     /* Pointers to child nodes */
+    const H5AC_class_t *grandchild_class; /* Pointer to grandchild node's class info */
+    haddr_t grandchild_addr;            /* Grandchild address */
+    void *grandchild = NULL;            /* Pointer to grandchild node */
     uint16_t *left_nrec, *right_nrec;   /* Pointers to child # of records */
     uint8_t *left_native, *right_native;/* Pointers to childs' native records */
     H5B2_node_ptr_t *left_node_ptrs = NULL, *right_node_ptrs = NULL;/* Pointers to childs' node pointer info */
     uint16_t mid_record;                /* Index of "middle" record in current node */
     uint16_t old_node_nrec;             /* Number of records in internal node split */
     unsigned left_child_flags = H5AC__NO_FLAGS_SET, right_child_flags = H5AC__NO_FLAGS_SET;     /* Flags for unprotecting child nodes */
+    unsigned u;                         /* Local index variable */
     herr_t ret_value = SUCCEED;         /* Return value */
 
     FUNC_ENTER_NOAPI_NOINIT
@@ -206,7 +219,7 @@ H5B2_split1(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth, H5B2_node_ptr_t *cur
 
         /* Create new internal node */
         internal->node_ptrs[idx + 1].all_nrec = internal->node_ptrs[idx + 1].node_nrec = 0;
-        if(H5B2_create_internal(hdr, dxpl_id, &(internal->node_ptrs[idx + 1]), (depth - 1)) < 0)
+        if(H5B2_create_internal(hdr, dxpl_id, internal, &(internal->node_ptrs[idx + 1]), (depth - 1)) < 0)
 	    HGOTO_ERROR(H5E_BTREE, H5E_CANTINIT, FAIL, "unable to create new internal node")
 
         /* Setup information for unlocking child nodes */
@@ -214,12 +227,19 @@ H5B2_split1(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth, H5B2_node_ptr_t *cur
         left_addr = internal->node_ptrs[idx].addr;
         right_addr = internal->node_ptrs[idx + 1].addr;
 
-        /* Protect both leafs */
-        if(NULL == (left_int = H5B2_protect_internal(hdr, dxpl_id, left_addr, internal->node_ptrs[idx].node_nrec, (depth - 1), H5AC_WRITE)))
+        /* Protect both leaves */
+        if(NULL == (left_int = H5B2_protect_internal(hdr, dxpl_id, left_addr, internal, internal->node_ptrs[idx].node_nrec, (depth - 1), H5AC_WRITE)))
             HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree internal node")
-        if(NULL == (right_int = H5B2_protect_internal(hdr, dxpl_id, right_addr, internal->node_ptrs[idx + 1].node_nrec, (depth - 1), H5AC_WRITE)))
+        if(NULL == (right_int = H5B2_protect_internal(hdr, dxpl_id, right_addr, internal, internal->node_ptrs[idx + 1].node_nrec, (depth - 1), H5AC_WRITE)))
             HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree internal node")
 
+        /* Shadow the left node if doing SWMR writes */
+        if(hdr->swmr_write) {
+            if(H5B2_shadow_internal(hdr, dxpl_id, (depth - 1), &(internal->node_ptrs[idx]), &left_int) < 0)
+                HGOTO_ERROR(H5E_BTREE, H5E_CANTCOPY, FAIL, "unable to shadow internal node")
+            left_addr = internal->node_ptrs[idx].addr;
+        } /* end if */
+
         /* More setup for child nodes */
         left_child = left_int;
         right_child = right_int;
@@ -235,7 +255,7 @@ H5B2_split1(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth, H5B2_node_ptr_t *cur
 
         /* Create new leaf node */
         internal->node_ptrs[idx + 1].all_nrec = internal->node_ptrs[idx + 1].node_nrec = 0;
-        if(H5B2_create_leaf(hdr, dxpl_id, &(internal->node_ptrs[idx + 1])) < 0)
+        if(H5B2_create_leaf(hdr, dxpl_id, internal, &(internal->node_ptrs[idx + 1])) < 0)
 	    HGOTO_ERROR(H5E_BTREE, H5E_CANTINIT, FAIL, "unable to create new leaf node")
 
         /* Setup information for unlocking child nodes */
@@ -243,12 +263,19 @@ H5B2_split1(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth, H5B2_node_ptr_t *cur
         left_addr = internal->node_ptrs[idx].addr;
         right_addr = internal->node_ptrs[idx + 1].addr;
 
-        /* Protect both leafs */
-        if(NULL == (left_leaf = H5B2_protect_leaf(hdr, dxpl_id, left_addr, internal->node_ptrs[idx].node_nrec, H5AC_WRITE)))
+        /* Protect both leaves */
+        if(NULL == (left_leaf = H5B2_protect_leaf(hdr, dxpl_id, left_addr, internal, internal->node_ptrs[idx].node_nrec, H5AC_WRITE)))
             HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree leaf node")
-        if(NULL == (right_leaf = H5B2_protect_leaf(hdr, dxpl_id, right_addr, internal->node_ptrs[idx + 1].node_nrec, H5AC_WRITE)))
+        if(NULL == (right_leaf = H5B2_protect_leaf(hdr, dxpl_id, right_addr, internal, internal->node_ptrs[idx + 1].node_nrec, H5AC_WRITE)))
             HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree leaf node")
 
+        /* Shadow the left node if doing SWMR writes */
+        if(hdr->swmr_write) {
+            if(H5B2_shadow_leaf(hdr, dxpl_id, &(internal->node_ptrs[idx]), &left_leaf) < 0)
+                HGOTO_ERROR(H5E_BTREE, H5E_CANTCOPY, FAIL, "unable to shadow internal node")
+            left_addr = internal->node_ptrs[idx].addr;
+        } /* end if */
+
         /* More setup for child nodes */
         left_child = left_leaf;
         right_child = right_leaf;
@@ -287,7 +314,6 @@ H5B2_split1(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth, H5B2_node_ptr_t *cur
 
     /* Determine total number of records in new child nodes */
     if(depth > 1) {
-        unsigned u;             /* Local index variable */
         hsize_t new_left_all_nrec;     /* New total number of records in left child */
         hsize_t new_right_all_nrec;    /* New total number of records in right child */
 
@@ -321,6 +347,76 @@ H5B2_split1(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth, H5B2_node_ptr_t *cur
     if(parent_cache_info_flags_ptr)
         *parent_cache_info_flags_ptr |= H5AC__DIRTIED_FLAG;
 
+    /* Update flush dependencies */
+    if(hdr->swmr_write) {
+        /* Update dependencies on records */
+        if(hdr->cls->upd_flush_dep) {
+            /* Update right child's records */
+            for(u = 0; u < *right_nrec; u++)
+                if(hdr->cls->upd_flush_dep(H5B2_NAT_NREC(right_native, hdr, u), udata, left_child, right_child) < 0)
+                    HGOTO_ERROR(H5E_BTREE, H5E_CANTDEPEND, FAIL, "unable to update flush dependency")
+
+            /* Update the middle record */
+            if(hdr->cls->upd_flush_dep(H5B2_INT_NREC(internal, hdr, idx), udata, left_child, internal) < 0)
+                HGOTO_ERROR(H5E_BTREE, H5E_CANTDEPEND, FAIL, "unable to update flush dependency")
+        } /* end if */
+
+        /* Update node pointers */
+        if(depth > 1) {
+            /* Loop over grandchildren */
+            for(u = 0; u < (*right_nrec + (unsigned)1); u++) {
+                hbool_t update_deps = FALSE;    /* Whether to update flush dependencies */
+
+                grandchild_addr = right_node_ptrs[u].addr;
+                if(depth > 2) {
+                    H5B2_internal_t *grandchild_int = NULL;
+
+                    /* Protect grandchild */
+                    if(NULL == (grandchild_int = H5B2_protect_internal(hdr, dxpl_id, grandchild_addr, right_child, right_node_ptrs[u].node_nrec, (depth - 2), H5AC_WRITE)))
+                        HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree internal node")
+                    grandchild_class = H5AC_BT2_INT;
+                    grandchild = grandchild_int;
+
+                    if(grandchild_int->parent == left_child) {
+                        grandchild_int->parent = right_child;
+                        update_deps = TRUE;
+                    } /* end if */
+                    else
+                        HDassert(grandchild_int->parent == right_child);
+                } /* end if */
+                else {
+                    H5B2_leaf_t *grandchild_leaf = NULL;
+
+                    /* Protect grandchild */
+                    if(NULL == (grandchild_leaf = H5B2_protect_leaf(hdr, dxpl_id, grandchild_addr, right_child, right_node_ptrs[u].node_nrec, H5AC_WRITE)))
+                        HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree leaf node")
+                    grandchild_class = H5AC_BT2_LEAF;
+                    grandchild = grandchild_leaf;
+
+                    if(grandchild_leaf->parent == left_child) {
+                        grandchild_leaf->parent = right_child;
+                        update_deps = TRUE;
+                    } /* end if */
+                    else
+                        HDassert(grandchild_leaf->parent == right_child);
+                } /* end else */
+
+                /* Update flush dependencies if necessary */
+                if(update_deps) {
+                    if(H5AC_destroy_flush_dependency(left_child, grandchild) < 0)
+                        HGOTO_ERROR(H5E_BTREE, H5E_CANTUNDEPEND, FAIL, "unable to destroy flush dependency")
+                    if(H5AC_create_flush_dependency(right_child, grandchild) < 0)
+                        HGOTO_ERROR(H5E_BTREE, H5E_CANTDEPEND, FAIL, "unable to create flush dependency")
+                } /* end if */
+
+                /* Unprotect the grandchild */
+                if(H5AC_unprotect(hdr->f, dxpl_id, grandchild_class, right_node_ptrs[u].addr, grandchild, H5AC__NO_FLAGS_SET) < 0)
+                    HGOTO_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, FAIL, "unable to release B-tree node")
+                grandchild = NULL;
+            } /* end for */
+        } /* end if */
+    } /* end if */
+
 #ifdef H5B2_DEBUG
     H5B2_assert_internal((hsize_t)0, hdr, internal);
     if(depth > 1) {
@@ -340,6 +436,17 @@ done:
     if(right_child && H5AC_unprotect(hdr->f, dxpl_id, child_class, right_addr, right_child, right_child_flags) < 0)
         HDONE_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, FAIL, "unable to release B-tree leaf node")
 
+    /* Release grandchild node if protected (only on error) */
+    if(grandchild && H5AC_unprotect(hdr->f, dxpl_id, grandchild_class, left_node_ptrs[u].addr, grandchild, H5AC__NO_FLAGS_SET) < 0)
+        HGOTO_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, FAIL, "unable to release B-tree node")
+
+    /* Unprotect the grandchild on error */
+    if(grandchild) {
+        HDassert(ret_value < 0);
+        if(H5AC_unprotect(hdr->f, dxpl_id, grandchild_class, grandchild_addr, grandchild, H5AC__NO_FLAGS_SET) < 0)
+            HGOTO_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, FAIL, "unable to release B-tree node")
+    } /* end if */
+
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5B2_split1 */
 
@@ -359,7 +466,7 @@ done:
  *-------------------------------------------------------------------------
  */
 herr_t
-H5B2_split_root(H5B2_hdr_t *hdr, hid_t dxpl_id)
+H5B2_split_root(H5B2_hdr_t *hdr, hid_t dxpl_id, void *udata)
 {
     H5B2_internal_t *new_root = NULL;   /* Pointer to new root node */
     unsigned new_root_flags = H5AC__NO_FLAGS_SET;   /* Cache flags for new root node */
@@ -399,18 +506,18 @@ H5B2_split_root(H5B2_hdr_t *hdr, hid_t dxpl_id)
 
     /* Create new internal node to use as root */
     hdr->root.node_nrec = 0;
-    if(H5B2_create_internal(hdr, dxpl_id, &(hdr->root), hdr->depth) < 0)
+    if(H5B2_create_internal(hdr, dxpl_id, hdr, &(hdr->root), hdr->depth) < 0)
         HGOTO_ERROR(H5E_BTREE, H5E_CANTINIT, FAIL, "unable to create new internal node")
 
     /* Protect new root node */
-    if(NULL == (new_root = H5B2_protect_internal(hdr, dxpl_id, hdr->root.addr, hdr->root.node_nrec, hdr->depth, H5AC_WRITE)))
+    if(NULL == (new_root = H5B2_protect_internal(hdr, dxpl_id, hdr->root.addr, hdr, hdr->root.node_nrec, hdr->depth, H5AC_WRITE)))
         HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree internal node")
 
     /* Set first node pointer in root node to old root node pointer info */
     new_root->node_ptrs[0] = old_root_ptr;
 
     /* Split original root node */
-    if(H5B2_split1(hdr, dxpl_id, hdr->depth, &(hdr->root), NULL, new_root, &new_root_flags, 0) < 0)
+    if(H5B2_split1(hdr, dxpl_id, hdr->depth, &(hdr->root), NULL, new_root, &new_root_flags, 0, udata) < 0)
         HGOTO_ERROR(H5E_BTREE, H5E_CANTSPLIT, FAIL, "unable to split old root node")
 
 done:
@@ -438,16 +545,20 @@ done:
  */
 static herr_t
 H5B2_redistribute2(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth,
-    H5B2_internal_t *internal, unsigned idx)
+    H5B2_internal_t *internal, unsigned idx, void *udata)
 {
     const H5AC_class_t *child_class;    /* Pointer to child node's class info */
     haddr_t left_addr, right_addr;      /* Addresses of left & right child nodes */
     void *left_child = NULL, *right_child = NULL;     /* Pointers to child nodes */
+    const H5AC_class_t *grandchild_class; /* Pointer to grandchild node's class info */
+    haddr_t grandchild_addr;            /* Grandchild address */
+    void *grandchild = NULL;            /* Pointer to grandchild node */
     uint16_t *left_nrec, *right_nrec;   /* Pointers to child # of records */
     uint8_t *left_native, *right_native;    /* Pointers to childs' native records */
     H5B2_node_ptr_t *left_node_ptrs = NULL, *right_node_ptrs = NULL;/* Pointers to childs' node pointer info */
     hssize_t left_moved_nrec = 0, right_moved_nrec = 0; /* Number of records moved, for internal redistrib */
     unsigned left_child_flags = H5AC__NO_FLAGS_SET, right_child_flags = H5AC__NO_FLAGS_SET;     /* Flags for unprotecting child nodes */
+    unsigned u;                         /* Local index variable */
     herr_t ret_value = SUCCEED;           /* Return value */
 
     FUNC_ENTER_NOAPI_NOINIT
@@ -467,11 +578,21 @@ H5B2_redistribute2(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth,
         right_addr = internal->node_ptrs[idx + 1].addr;
 
         /* Lock left & right B-tree child nodes */
-        if(NULL == (left_internal = H5B2_protect_internal(hdr, dxpl_id, left_addr, internal->node_ptrs[idx].node_nrec, (depth - 1), H5AC_WRITE)))
+        if(NULL == (left_internal = H5B2_protect_internal(hdr, dxpl_id, left_addr, internal, internal->node_ptrs[idx].node_nrec, (depth - 1), H5AC_WRITE)))
             HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree leaf node")
-        if(NULL == (right_internal = H5B2_protect_internal(hdr, dxpl_id, right_addr, internal->node_ptrs[idx + 1].node_nrec, (depth - 1), H5AC_WRITE)))
+        if(NULL == (right_internal = H5B2_protect_internal(hdr, dxpl_id, right_addr, internal, internal->node_ptrs[idx + 1].node_nrec, (depth - 1), H5AC_WRITE)))
             HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree leaf node")
 
+        /* Shadow both nodes if doing SWMR writes */
+        if(hdr->swmr_write) {
+            if(H5B2_shadow_internal(hdr, dxpl_id, (depth - 1), &(internal->node_ptrs[idx]), &left_internal) < 0)
+                HGOTO_ERROR(H5E_BTREE, H5E_CANTCOPY, FAIL, "unable to shadow internal node")
+            if(H5B2_shadow_internal(hdr, dxpl_id, (depth - 1), &(internal->node_ptrs[idx + 1]), &right_internal) < 0)
+                HGOTO_ERROR(H5E_BTREE, H5E_CANTCOPY, FAIL, "unable to shadow internal node")
+            left_addr = internal->node_ptrs[idx].addr;
+            right_addr = internal->node_ptrs[idx + 1].addr;
+        } /* end if */
+
         /* More setup for child nodes */
         left_child = left_internal;
         right_child = right_internal;
@@ -492,11 +613,21 @@ H5B2_redistribute2(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth,
         right_addr = internal->node_ptrs[idx + 1].addr;
 
         /* Lock left & right B-tree child nodes */
-        if(NULL == (left_leaf = H5B2_protect_leaf(hdr, dxpl_id, left_addr, internal->node_ptrs[idx].node_nrec, H5AC_WRITE)))
+        if(NULL == (left_leaf = H5B2_protect_leaf(hdr, dxpl_id, left_addr, internal, internal->node_ptrs[idx].node_nrec, H5AC_WRITE)))
             HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree leaf node")
-        if(NULL == (right_leaf = H5B2_protect_leaf(hdr, dxpl_id, right_addr, internal->node_ptrs[idx + 1].node_nrec, H5AC_WRITE)))
+        if(NULL == (right_leaf = H5B2_protect_leaf(hdr, dxpl_id, right_addr, internal, internal->node_ptrs[idx + 1].node_nrec, H5AC_WRITE)))
             HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree leaf node")
 
+        /* Shadow both nodes if doing SWMR writes */
+        if(hdr->swmr_write) {
+            if(H5B2_shadow_leaf(hdr, dxpl_id, &(internal->node_ptrs[idx]), &left_leaf) < 0)
+                HGOTO_ERROR(H5E_BTREE, H5E_CANTCOPY, FAIL, "unable to shadow leaf node")
+            if(H5B2_shadow_leaf(hdr, dxpl_id, &(internal->node_ptrs[idx + 1]), &right_leaf) < 0)
+                HGOTO_ERROR(H5E_BTREE, H5E_CANTCOPY, FAIL, "unable to shadow leaf node")
+            left_addr = internal->node_ptrs[idx].addr;
+            right_addr = internal->node_ptrs[idx + 1].addr;
+        } /* end if */
+
         /* More setup for child nodes */
         left_child = left_leaf;
         right_child = right_leaf;
@@ -541,7 +672,6 @@ H5B2_redistribute2(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth,
         /* Handle node pointers, if we have an internal node */
         if(depth > 1) {
             hsize_t moved_nrec = move_nrec;   /* Total number of records moved, for internal redistrib */
-            unsigned u;             /* Local index variable */
 
             /* Count the number of records being moved */
             for(u = 0; u < move_nrec; u++)
@@ -556,6 +686,80 @@ H5B2_redistribute2(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth,
             HDmemmove(&(right_node_ptrs[0]), &(right_node_ptrs[move_nrec]), sizeof(H5B2_node_ptr_t) * (new_right_nrec + (unsigned)1));
         } /* end if */
 
+        /* Update flush dependencies */
+        if(hdr->swmr_write) {
+            /* Update dependencies on records */
+            if(hdr->cls->upd_flush_dep) {
+                /* Update the old middle record */
+                if(hdr->cls->upd_flush_dep(H5B2_NAT_NREC(left_native, hdr, *left_nrec), udata, internal, left_child) < 0)
+                    HGOTO_ERROR(H5E_BTREE, H5E_CANTDEPEND, FAIL, "unable to update flush dependency")
+
+                /* Update left child's records moved from right child */
+                for(u = (*left_nrec + (unsigned)1); u < *left_nrec + move_nrec; u++)
+                    if(hdr->cls->upd_flush_dep(H5B2_NAT_NREC(left_native, hdr, u), udata, right_child, left_child) < 0)
+                        HGOTO_ERROR(H5E_BTREE, H5E_CANTDEPEND, FAIL, "unable to update flush dependency")
+
+                /* Update the new middle record */
+                if(hdr->cls->upd_flush_dep(H5B2_INT_NREC(internal, hdr, idx), udata, right_child, internal) < 0)
+                    HGOTO_ERROR(H5E_BTREE, H5E_CANTDEPEND, FAIL, "unable to update flush dependency")
+            } /* end if */
+
+            /* Update node pointers */
+            if(depth > 1) {
+                /* Loop over grandchildren */
+                for(u = (*left_nrec + (unsigned)1); u < (*left_nrec + (unsigned)move_nrec + (unsigned)1); u++) {
+                    hbool_t update_deps = FALSE;    /* Whether to update flush dependencies */
+
+                    grandchild_addr = left_node_ptrs[u].addr;
+                    if(depth > 2) {
+                        H5B2_internal_t *grandchild_int = NULL;
+
+                        /* Protect grandchild */
+                        if(NULL == (grandchild_int = H5B2_protect_internal(hdr, dxpl_id, grandchild_addr, left_child, left_node_ptrs[u].node_nrec, (depth - 2), H5AC_WRITE)))
+                            HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree internal node")
+                        grandchild_class = H5AC_BT2_INT;
+                        grandchild = grandchild_int;
+
+                        if(grandchild_int->parent == right_child) {
+                            grandchild_int->parent = left_child;
+                            update_deps = TRUE;
+                        } /* end if */
+                        else
+                            HDassert(grandchild_int->parent == left_child);
+                    } /* end if */
+                    else {
+                        H5B2_leaf_t *grandchild_leaf = NULL;
+
+                        /* Protect grandchild */
+                        if(NULL == (grandchild_leaf = H5B2_protect_leaf(hdr, dxpl_id, grandchild_addr, left_child, left_node_ptrs[u].node_nrec, H5AC_WRITE)))
+                            HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree leaf node")
+                        grandchild_class = H5AC_BT2_LEAF;
+                        grandchild = grandchild_leaf;
+
+                        if(grandchild_leaf->parent == right_child) {
+                            grandchild_leaf->parent = left_child;
+                            update_deps = TRUE;
+                        } /* end if */
+                        else
+                            HDassert(grandchild_leaf->parent == left_child);
+                    } /* end else */
+
+                    /* Update flush dependencies if necessary */
+                    if(update_deps) {
+                        if(H5AC_destroy_flush_dependency(right_child, grandchild) < 0)
+                            HGOTO_ERROR(H5E_BTREE, H5E_CANTUNDEPEND, FAIL, "unable to destroy flush dependency")
+                        if(H5AC_create_flush_dependency(left_child, grandchild) < 0)
+                            HGOTO_ERROR(H5E_BTREE, H5E_CANTDEPEND, FAIL, "unable to create flush dependency")
+                    } /* end if */
+
+                    /* Unprotect the grandchild */
+                    if(H5AC_unprotect(hdr->f, dxpl_id, grandchild_class, left_node_ptrs[u].addr, grandchild, H5AC__NO_FLAGS_SET) < 0)
+                        HGOTO_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, FAIL, "unable to release B-tree node")
+                    grandchild = NULL;
+                } /* end for */
+            } /* end if */
+        } /* end if */
+
         /* Update number of records in child nodes */
         *left_nrec = (uint16_t)(*left_nrec + move_nrec);
         *right_nrec = new_right_nrec;
@@ -570,6 +774,8 @@ H5B2_redistribute2(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth,
         uint16_t new_left_nrec = (uint16_t)(*left_nrec + *right_nrec) / 2;    /* New number of records for left child */
         uint16_t move_nrec = (uint16_t)(*left_nrec - new_left_nrec);        /* Number of records to move from left node to right */
 
+        HDassert(*left_nrec > *right_nrec);
+
         /* Slide records in right node up */
         HDmemmove(H5B2_NAT_NREC(right_native, hdr, move_nrec),
                 H5B2_NAT_NREC(right_native, hdr, 0),
@@ -588,7 +794,6 @@ H5B2_redistribute2(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth,
         /* Handle node pointers, if we have an internal node */
         if(depth > 1) {
             hsize_t moved_nrec = move_nrec;   /* Total number of records moved, for internal redistrib */
-            unsigned u;             /* Local index variable */
 
             /* Slide node pointers in right node up */
             HDmemmove(&(right_node_ptrs[move_nrec]), &(right_node_ptrs[0]), sizeof(H5B2_node_ptr_t) * (size_t)(*right_nrec + 1));
@@ -603,6 +808,80 @@ H5B2_redistribute2(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth,
             H5_ASSIGN_OVERFLOW(/* To: */ right_moved_nrec, /* From: */ moved_nrec, /* From: */ hsize_t, /* To: */ hssize_t)
         } /* end if */
 
+        /* Update flush dependencies */
+        if(hdr->swmr_write) {
+            /* Update dependencies on records */
+            if(hdr->cls->upd_flush_dep) {
+                /* Update the old middle record */
+                if(hdr->cls->upd_flush_dep(H5B2_NAT_NREC(right_native, hdr, (move_nrec - 1)), udata, internal, right_child) < 0)
+                    HGOTO_ERROR(H5E_BTREE, H5E_CANTDEPEND, FAIL, "unable to update flush dependency")
+
+                /* Update right child's records moved from left child */
+                for(u = 0; u < (unsigned)(move_nrec - 1); u++)
+                    if(hdr->cls->upd_flush_dep(H5B2_NAT_NREC(right_native, hdr, u), udata, left_child, right_child) < 0)
+                        HGOTO_ERROR(H5E_BTREE, H5E_CANTDEPEND, FAIL, "unable to update flush dependency")
+
+                /* Update the new middle record */
+                if(hdr->cls->upd_flush_dep(H5B2_INT_NREC(internal, hdr, idx), udata, left_child, internal) < 0)
+                    HGOTO_ERROR(H5E_BTREE, H5E_CANTDEPEND, FAIL, "unable to update flush dependency")
+            } /* end if */
+
+            /* Update node pointers */
+            if(depth > 1) {
+                /* Loop over grandchildren */
+                for(u = 0; u < move_nrec; u++) {
+                    hbool_t update_deps = FALSE;    /* Whether to update flush dependencies */
+
+                    grandchild_addr = right_node_ptrs[u].addr;
+                    if(depth > 2) {
+                        H5B2_internal_t *grandchild_int = NULL;
+
+                        /* Protect grandchild */
+                        if(NULL == (grandchild_int = H5B2_protect_internal(hdr, dxpl_id, grandchild_addr, right_child, right_node_ptrs[u].node_nrec, (depth - 2), H5AC_WRITE)))
+                            HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree internal node")
+                        grandchild_class = H5AC_BT2_INT;
+                        grandchild = grandchild_int;
+
+                        if(grandchild_int->parent == left_child) {
+                            grandchild_int->parent = right_child;
+                            update_deps = TRUE;
+                        } /* end if */
+                        else
+                            HDassert(grandchild_int->parent == right_child);
+                    } /* end if */
+                    else {
+                        H5B2_leaf_t *grandchild_leaf = NULL;
+
+                        /* Protect grandchild */
+                        if(NULL == (grandchild_leaf = H5B2_protect_leaf(hdr, dxpl_id, grandchild_addr, right_child, right_node_ptrs[u].node_nrec, H5AC_WRITE)))
+                            HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree leaf node")
+                        grandchild_class = H5AC_BT2_LEAF;
+                        grandchild = grandchild_leaf;
+
+                        if(grandchild_leaf->parent == left_child) {
+                            grandchild_leaf->parent = right_child;
+                            update_deps = TRUE;
+                        } /* end if */
+                        else
+                            HDassert(grandchild_leaf->parent == right_child);
+                    } /* end else */
+
+                    /* Update flush dependencies if necessary */
+                    if(update_deps) {
+                        if(H5AC_destroy_flush_dependency(left_child, grandchild) < 0)
+                            HGOTO_ERROR(H5E_BTREE, H5E_CANTUNDEPEND, FAIL, "unable to destroy flush dependency")
+                        if(H5AC_create_flush_dependency(right_child, grandchild) < 0)
+                            HGOTO_ERROR(H5E_BTREE, H5E_CANTDEPEND, FAIL, "unable to create flush dependency")
+                    } /* end if */
+
+                    /* Unprotect the grandchild */
+                    if(H5AC_unprotect(hdr->f, dxpl_id, grandchild_class, right_node_ptrs[u].addr, grandchild, H5AC__NO_FLAGS_SET) < 0)
+                        HGOTO_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, FAIL, "unable to release B-tree node")
+                    grandchild = NULL;
+                } /* end for */
+            } /* end if */
+        } /* end if */
+
         /* Update number of records in child nodes */
         *left_nrec = new_left_nrec;
         *right_nrec = (uint16_t)(*right_nrec + move_nrec);
@@ -645,6 +924,17 @@ done:
     if(right_child && H5AC_unprotect(hdr->f, dxpl_id, child_class, right_addr, right_child, right_child_flags) < 0)
         HDONE_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, FAIL, "unable to release B-tree child node")
 
+    /* Release grandchild node if protected (only on error) */
+    if(grandchild && H5AC_unprotect(hdr->f, dxpl_id, grandchild_class, left_node_ptrs[u].addr, grandchild, H5AC__NO_FLAGS_SET) < 0)
+        HGOTO_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, FAIL, "unable to release B-tree node")
+
+    /* Unprotect the grandchild on error */
+    if(grandchild) {
+        HDassert(ret_value < 0);
+        if(H5AC_unprotect(hdr->f, dxpl_id, grandchild_class, grandchild_addr, grandchild, H5AC__NO_FLAGS_SET) < 0)
+            HGOTO_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, FAIL, "unable to release B-tree node")
+    } /* end if */
+
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5B2_redistribute2 */
 
@@ -665,7 +955,8 @@ done:
  */
 static herr_t
 H5B2_redistribute3(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth,
-    H5B2_internal_t *internal, unsigned *internal_flags_ptr, unsigned idx)
+    H5B2_internal_t *internal, unsigned *internal_flags_ptr, unsigned idx,
+    void *udata)
 {
     H5B2_node_ptr_t *left_node_ptrs = NULL, *right_node_ptrs = NULL; /* Pointers to childs' node pointer info */
     H5B2_node_ptr_t *middle_node_ptrs = NULL; /* Pointers to childs' node pointer info */
@@ -674,6 +965,9 @@ H5B2_redistribute3(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth,
     haddr_t middle_addr;                /* Address of middle child node */
     void *left_child = NULL, *right_child = NULL;     /* Pointers to child nodes */
     void *middle_child = NULL;          /* Pointers to middle child node */
+    const H5AC_class_t *grandchild_class; /* Pointer to grandchild node's class info */
+    haddr_t grandchild_addr;            /* Grandchild address */
+    void *grandchild = NULL;            /* Pointer to grandchild node */
     uint16_t *left_nrec, *right_nrec;   /* Pointers to child # of records */
     uint16_t *middle_nrec;              /* Pointers to middle child # of records */
     uint8_t *left_native, *right_native;    /* Pointers to childs' native records */
@@ -682,6 +976,7 @@ H5B2_redistribute3(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth,
     hssize_t middle_moved_nrec = 0;     /* Number of records moved, for internal split */
     unsigned left_child_flags = H5AC__NO_FLAGS_SET, right_child_flags = H5AC__NO_FLAGS_SET;     /* Flags for unprotecting child nodes */
     unsigned middle_child_flags = H5AC__NO_FLAGS_SET;     /* Flags for unprotecting child nodes */
+    unsigned u;                         /* Local index variable */
     herr_t ret_value = SUCCEED;         /* Return value */
 
     FUNC_ENTER_NOAPI_NOINIT
@@ -704,13 +999,26 @@ H5B2_redistribute3(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth,
         right_addr = internal->node_ptrs[idx + 1].addr;
 
         /* Lock B-tree child nodes */
-        if(NULL == (left_internal = H5B2_protect_internal(hdr, dxpl_id, left_addr, internal->node_ptrs[idx - 1].node_nrec, (depth - 1), H5AC_WRITE)))
+        if(NULL == (left_internal = H5B2_protect_internal(hdr, dxpl_id, left_addr, internal, internal->node_ptrs[idx - 1].node_nrec, (depth - 1), H5AC_WRITE)))
             HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree internal node")
-        if(NULL == (middle_internal = H5B2_protect_internal(hdr, dxpl_id, middle_addr, internal->node_ptrs[idx].node_nrec, (depth - 1), H5AC_WRITE)))
+        if(NULL == (middle_internal = H5B2_protect_internal(hdr, dxpl_id, middle_addr, internal, internal->node_ptrs[idx].node_nrec, (depth - 1), H5AC_WRITE)))
             HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree internal node")
-        if(NULL == (right_internal = H5B2_protect_internal(hdr, dxpl_id, right_addr, internal->node_ptrs[idx + 1].node_nrec, (depth - 1), H5AC_WRITE)))
+        if(NULL == (right_internal = H5B2_protect_internal(hdr, dxpl_id, right_addr, internal, internal->node_ptrs[idx + 1].node_nrec, (depth - 1), H5AC_WRITE)))
             HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree internal node")
 
+        /* Shadow all nodes if doing SWMR writes */
+        if(hdr->swmr_write) {
+            if(H5B2_shadow_internal(hdr, dxpl_id, (depth - 1), &(internal->node_ptrs[idx - 1]), &left_internal) < 0)
+                HGOTO_ERROR(H5E_BTREE, H5E_CANTCOPY, FAIL, "unable to shadow internal node")
+            if(H5B2_shadow_internal(hdr, dxpl_id, (depth - 1), &(internal->node_ptrs[idx]), &middle_internal) < 0)
+                HGOTO_ERROR(H5E_BTREE, H5E_CANTCOPY, FAIL, "unable to shadow internal node")
+            if(H5B2_shadow_internal(hdr, dxpl_id, (depth - 1), &(internal->node_ptrs[idx + 1]), &right_internal) < 0)
+                HGOTO_ERROR(H5E_BTREE, H5E_CANTCOPY, FAIL, "unable to shadow internal node")
+            left_addr = internal->node_ptrs[idx - 1].addr;
+            middle_addr = internal->node_ptrs[idx].addr;
+            right_addr = internal->node_ptrs[idx + 1].addr;
+        } /* end if */
+
         /* More setup for child nodes */
         left_child = left_internal;
         middle_child = middle_internal;
@@ -737,13 +1045,26 @@ H5B2_redistribute3(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth,
         right_addr = internal->node_ptrs[idx + 1].addr;
 
         /* Lock B-tree child nodes */
-        if(NULL == (left_leaf = H5B2_protect_leaf(hdr, dxpl_id, left_addr, internal->node_ptrs[idx - 1].node_nrec, H5AC_WRITE)))
+        if(NULL == (left_leaf = H5B2_protect_leaf(hdr, dxpl_id, left_addr, internal, internal->node_ptrs[idx - 1].node_nrec, H5AC_WRITE)))
             HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree leaf node")
-        if(NULL == (middle_leaf = H5B2_protect_leaf(hdr, dxpl_id, middle_addr, internal->node_ptrs[idx].node_nrec, H5AC_WRITE)))
+        if(NULL == (middle_leaf = H5B2_protect_leaf(hdr, dxpl_id, middle_addr, internal, internal->node_ptrs[idx].node_nrec, H5AC_WRITE)))
             HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree leaf node")
-        if(NULL == (right_leaf = H5B2_protect_leaf(hdr, dxpl_id, right_addr, internal->node_ptrs[idx + 1].node_nrec, H5AC_WRITE)))
+        if(NULL == (right_leaf = H5B2_protect_leaf(hdr, dxpl_id, right_addr, internal, internal->node_ptrs[idx + 1].node_nrec, H5AC_WRITE)))
             HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree leaf node")
 
+        /* Shadow all nodes if doing SWMR writes */
+        if(hdr->swmr_write) {
+            if(H5B2_shadow_leaf(hdr, dxpl_id, &(internal->node_ptrs[idx - 1]), &left_leaf) < 0)
+                HGOTO_ERROR(H5E_BTREE, H5E_CANTCOPY, FAIL, "unable to shadow leaf node")
+            if(H5B2_shadow_leaf(hdr, dxpl_id, &(internal->node_ptrs[idx]), &middle_leaf) < 0)
+                HGOTO_ERROR(H5E_BTREE, H5E_CANTCOPY, FAIL, "unable to shadow leaf node")
+            if(H5B2_shadow_leaf(hdr, dxpl_id, &(internal->node_ptrs[idx + 1]), &right_leaf) < 0)
+                HGOTO_ERROR(H5E_BTREE, H5E_CANTCOPY, FAIL, "unable to shadow leaf node")
+            left_addr = internal->node_ptrs[idx - 1].addr;
+            middle_addr = internal->node_ptrs[idx].addr;
+            right_addr = internal->node_ptrs[idx + 1].addr;
+        } /* end if */
+
         /* More setup for child nodes */
         left_child = left_leaf;
         middle_child = middle_leaf;
@@ -793,7 +1114,6 @@ H5B2_redistribute3(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth,
             if(depth > 1) {
                 hsize_t moved_nrec;         /* Total number of records moved, for internal redistrib */
                 unsigned move_nptrs;    /* Number of node pointers to move */
-                unsigned u;             /* Local index variable */
 
                 /* Move middle node pointers into left node */
                 move_nptrs = (unsigned)(new_left_nrec - *left_nrec);
@@ -809,6 +1129,80 @@ H5B2_redistribute3(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth,
                 HDmemmove(&(middle_node_ptrs[0]), &(middle_node_ptrs[move_nptrs]), sizeof(H5B2_node_ptr_t) * ((*middle_nrec - move_nptrs) + 1));
             } /* end if */
 
+            /* Update flush dependencies */
+            if(hdr->swmr_write) {
+                /* Update dependencies on records */
+                if(hdr->cls->upd_flush_dep) {
+                    /* Update the old parent record */
+                    if(hdr->cls->upd_flush_dep(H5B2_NAT_NREC(left_native, hdr, *left_nrec), udata, internal, left_child) < 0)
+                        HGOTO_ERROR(H5E_BTREE, H5E_CANTDEPEND, FAIL, "unable to update flush dependency")
+
+                    /* Update left child's records moved from middle child */
+                    for(u = (*left_nrec + (unsigned)1); u < *left_nrec + (unsigned)moved_middle_nrec; u++)
+                        if(hdr->cls->upd_flush_dep(H5B2_NAT_NREC(left_native, hdr, u), udata, middle_child, left_child) < 0)
+                            HGOTO_ERROR(H5E_BTREE, H5E_CANTDEPEND, FAIL, "unable to update flush dependency")
+
+                    /* Update the new parent record */
+                    if(hdr->cls->upd_flush_dep(H5B2_INT_NREC(internal, hdr, idx - 1), udata, middle_child, internal) < 0)
+                        HGOTO_ERROR(H5E_BTREE, H5E_CANTDEPEND, FAIL, "unable to update flush dependency")
+                } /* end if */
+
+                /* Update node pointers */
+                if(depth > 1) {
+                    /* Loop over grandchildren */
+                    for(u = (*left_nrec + (unsigned)1); u < (*left_nrec + (unsigned)moved_middle_nrec + 1); u++) {
+                        hbool_t update_deps = FALSE;    /* Whether to update flush dependencies */
+
+                        grandchild_addr = left_node_ptrs[u].addr;
+                        if(depth > 2) {
+                            H5B2_internal_t *grandchild_int = NULL;
+
+                            /* Protect grandchild */
+                            if(NULL == (grandchild_int = H5B2_protect_internal(hdr, dxpl_id, grandchild_addr, left_child, left_node_ptrs[u].node_nrec, (depth - 2), H5AC_WRITE)))
+                                HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree internal node")
+                            grandchild_class = H5AC_BT2_INT;
+                            grandchild = grandchild_int;
+
+                            if(grandchild_int->parent == middle_child) {
+                                grandchild_int->parent = left_child;
+                                update_deps = TRUE;
+                            } /* end if */
+                            else
+                                HDassert(grandchild_int->parent == left_child);
+                        } /* end if */
+                        else {
+                            H5B2_leaf_t *grandchild_leaf = NULL;
+
+                            /* Protect grandchild */
+                            if(NULL == (grandchild_leaf = H5B2_protect_leaf(hdr, dxpl_id, grandchild_addr, left_child, left_node_ptrs[u].node_nrec, H5AC_WRITE)))
+                                HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree leaf node")
+                            grandchild_class = H5AC_BT2_LEAF;
+                            grandchild = grandchild_leaf;
+
+                            if(grandchild_leaf->parent == middle_child) {
+                                grandchild_leaf->parent = left_child;
+                                update_deps = TRUE;
+                            } /* end if */
+                            else
+                                HDassert(grandchild_leaf->parent == left_child);
+                        } /* end else */
+
+                        /* Update flush dependencies if necessary */
+                        if(update_deps) {
+                            if(H5AC_destroy_flush_dependency(middle_child, grandchild) < 0)
+                                HGOTO_ERROR(H5E_BTREE, H5E_CANTUNDEPEND, FAIL, "unable to destroy flush dependency")
+                            if(H5AC_create_flush_dependency(left_child, grandchild) < 0)
+                                HGOTO_ERROR(H5E_BTREE, H5E_CANTDEPEND, FAIL, "unable to create flush dependency")
+                        } /* end if */
+
+                        /* Unprotect the grandchild */
+                        if(H5AC_unprotect(hdr->f, dxpl_id, grandchild_class, left_node_ptrs[u].addr, grandchild, H5AC__NO_FLAGS_SET) < 0)
+                            HGOTO_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, FAIL, "unable to release B-tree node")
+                        grandchild = NULL;
+                    } /* end for */
+                } /* end if */
+            } /* end if */
+
             /* Update the current number of records in middle node */
             curr_middle_nrec = (uint16_t)(curr_middle_nrec - moved_middle_nrec);
 
@@ -837,7 +1231,6 @@ H5B2_redistribute3(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth,
             /* Move node pointers also if this is an internal node */
             if(depth > 1) {
                 hsize_t moved_nrec;         /* Total number of records moved, for internal redistrib */
-                unsigned u;             /* Local index variable */
 
                 /* Slide the node pointers in right node up */
                 HDmemmove(&(right_node_ptrs[right_nrec_move]), &(right_node_ptrs[0]), sizeof(H5B2_node_ptr_t) * (size_t)(*right_nrec + 1));
@@ -852,6 +1245,80 @@ H5B2_redistribute3(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth,
                 middle_moved_nrec -= (hssize_t)(moved_nrec + right_nrec_move);
             } /* end if */
 
+            /* Update flush dependencies */
+            if(hdr->swmr_write) {
+                /* Update dependencies on records */
+                if(hdr->cls->upd_flush_dep) {
+                    /* Update the old parent record */
+                    if(hdr->cls->upd_flush_dep(H5B2_NAT_NREC(right_native, hdr, (right_nrec_move - 1)), udata, internal, right_child) < 0)
+                        HGOTO_ERROR(H5E_BTREE, H5E_CANTDEPEND, FAIL, "unable to update flush dependency")
+
+                    /* Update right child's records moved from middle child */
+                    for(u = 0; u < (right_nrec_move - 1); u++)
+                        if(hdr->cls->upd_flush_dep(H5B2_NAT_NREC(right_native, hdr, u), udata, middle_child, right_child) < 0)
+                            HGOTO_ERROR(H5E_BTREE, H5E_CANTDEPEND, FAIL, "unable to update flush dependency")
+
+                    /* Update the new parent record */
+                    if(hdr->cls->upd_flush_dep(H5B2_INT_NREC(internal, hdr, idx), udata, middle_child, internal) < 0)
+                        HGOTO_ERROR(H5E_BTREE, H5E_CANTDEPEND, FAIL, "unable to update flush dependency")
+                } /* end if */
+
+                /* Update node pointers */
+                if(depth > 1) {
+                    /* Loop over grandchildren */
+                    for(u = 0; u < right_nrec_move; u++) {
+                        hbool_t update_deps = FALSE;    /* Whether to update flush dependencies */
+
+                        grandchild_addr = right_node_ptrs[u].addr;
+                        if(depth > 2) {
+                            H5B2_internal_t *grandchild_int = NULL;
+
+                            /* Protect grandchild */
+                            if(NULL == (grandchild_int = H5B2_protect_internal(hdr, dxpl_id, grandchild_addr, right_child, right_node_ptrs[u].node_nrec, (depth - 2), H5AC_WRITE)))
+                                HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree internal node")
+                            grandchild_class = H5AC_BT2_INT;
+                            grandchild = grandchild_int;
+
+                            if(grandchild_int->parent == middle_child) {
+                                grandchild_int->parent = right_child;
+                                update_deps = TRUE;
+                            } /* end if */
+                            else
+                                HDassert(grandchild_int->parent == right_child);
+                        } /* end if */
+                        else {
+                            H5B2_leaf_t *grandchild_leaf = NULL;
+
+                            /* Protect grandchild */
+                            if(NULL == (grandchild_leaf = H5B2_protect_leaf(hdr, dxpl_id, grandchild_addr, right_child, right_node_ptrs[u].node_nrec, H5AC_WRITE)))
+                                HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree leaf node")
+                            grandchild_class = H5AC_BT2_LEAF;
+                            grandchild = grandchild_leaf;
+
+                            if(grandchild_leaf->parent == middle_child) {
+                                grandchild_leaf->parent = right_child;
+                                update_deps = TRUE;
+                            } /* end if */
+                            else
+                                HDassert(grandchild_leaf->parent == right_child);
+                        } /* end else */
+
+                        /* Update flush dependencies if necessary */
+                        if(update_deps) {
+                            if(H5AC_destroy_flush_dependency(middle_child, grandchild) < 0)
+                                HGOTO_ERROR(H5E_BTREE, H5E_CANTUNDEPEND, FAIL, "unable to destroy flush dependency")
+                            if(H5AC_create_flush_dependency(right_child, grandchild) < 0)
+                                HGOTO_ERROR(H5E_BTREE, H5E_CANTDEPEND, FAIL, "unable to create flush dependency")
+                        } /* end if */
+
+                        /* Unprotect the grandchild */
+                        if(H5AC_unprotect(hdr->f, dxpl_id, grandchild_class, right_node_ptrs[u].addr, grandchild, H5AC__NO_FLAGS_SET) < 0)
+                            HGOTO_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, FAIL, "unable to release B-tree node")
+                        grandchild = NULL;
+                    } /* end for */
+                } /* end if */
+            } /* end if */
+
             /* Update the current number of records in middle node */
             curr_middle_nrec = (uint16_t)(curr_middle_nrec - right_nrec_move);
 
@@ -880,7 +1347,6 @@ H5B2_redistribute3(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth,
             /* Move node pointers also if this is an internal node */
             if(depth > 1) {
                 hsize_t moved_nrec;         /* Total number of records moved, for internal redistrib */
-                unsigned u;             /* Local index variable */
 
                 /* Slide the node pointers in middle node up */
                 HDmemmove(&(middle_node_ptrs[left_nrec_move]), &(middle_node_ptrs[0]), sizeof(H5B2_node_ptr_t) * (size_t)(curr_middle_nrec + 1));
@@ -895,6 +1361,80 @@ H5B2_redistribute3(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth,
                 middle_moved_nrec += (hssize_t)(moved_nrec + left_nrec_move);
             } /* end if */
 
+            /* Update flush dependencies */
+            if(hdr->swmr_write) {
+                /* Update dependencies on records */
+                if(hdr->cls->upd_flush_dep) {
+                    /* Update the old parent record */
+                    if(hdr->cls->upd_flush_dep(H5B2_NAT_NREC(middle_native, hdr, (left_nrec_move - 1)), udata, internal, middle_child) < 0)
+                        HGOTO_ERROR(H5E_BTREE, H5E_CANTDEPEND, FAIL, "unable to update flush dependency")
+
+                    /* Update middle child's records moved from left child */
+                    for(u = 0; u < (left_nrec_move - 1); u++)
+                        if(hdr->cls->upd_flush_dep(H5B2_NAT_NREC(middle_native, hdr, u), udata, left_child, middle_child) < 0)
+                            HGOTO_ERROR(H5E_BTREE, H5E_CANTDEPEND, FAIL, "unable to update flush dependency")
+
+                    /* Update the new parent record */
+                    if(hdr->cls->upd_flush_dep(H5B2_INT_NREC(internal, hdr, idx - 1), udata, left_child, internal) < 0)
+                        HGOTO_ERROR(H5E_BTREE, H5E_CANTDEPEND, FAIL, "unable to update flush dependency")
+                } /* end if */
+
+                /* Update node pointers */
+                if(depth > 1) {
+                    /* Loop over grandchildren */
+                    for(u = 0; u < left_nrec_move; u++) {
+                        hbool_t update_deps = FALSE;    /* Whether to update flush dependencies */
+
+                        grandchild_addr = middle_node_ptrs[u].addr;
+                        if(depth > 2) {
+                            H5B2_internal_t *grandchild_int = NULL;
+
+                            /* Protect grandchild */
+                            if(NULL == (grandchild_int = H5B2_protect_internal(hdr, dxpl_id, grandchild_addr, middle_child, middle_node_ptrs[u].node_nrec, (depth - 2), H5AC_WRITE)))
+                                HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree internal node")
+                            grandchild_class = H5AC_BT2_INT;
+                            grandchild = grandchild_int;
+
+                            if(grandchild_int->parent == left_child) {
+                                grandchild_int->parent = middle_child;
+                                update_deps = TRUE;
+                            } /* end if */
+                            else
+                                HDassert(grandchild_int->parent == middle_child);
+                        } /* end if */
+                        else {
+                            H5B2_leaf_t *grandchild_leaf = NULL;
+
+                            /* Protect grandchild */
+                            if(NULL == (grandchild_leaf = H5B2_protect_leaf(hdr, dxpl_id, grandchild_addr, middle_child, middle_node_ptrs[u].node_nrec, H5AC_WRITE)))
+                                HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree leaf node")
+                            grandchild_class = H5AC_BT2_LEAF;
+                            grandchild = grandchild_leaf;
+
+                            if(grandchild_leaf->parent == left_child) {
+                                grandchild_leaf->parent = middle_child;
+                                update_deps = TRUE;
+                            } /* end if */
+                            else
+                                HDassert(grandchild_leaf->parent == middle_child);
+                        } /* end for */
+
+                        /* Update flush dependencies if necessary */
+                        if(update_deps) {
+                            if(H5AC_destroy_flush_dependency(left_child, grandchild) < 0)
+                                HGOTO_ERROR(H5E_BTREE, H5E_CANTUNDEPEND, FAIL, "unable to destroy flush dependency")
+                            if(H5AC_create_flush_dependency(middle_child, grandchild) < 0)
+                                HGOTO_ERROR(H5E_BTREE, H5E_CANTDEPEND, FAIL, "unable to create flush dependency")
+                        } /* end else */
+
+                        /* Unprotect the grandchild */
+                        if(H5AC_unprotect(hdr->f, dxpl_id, grandchild_class, middle_node_ptrs[u].addr, grandchild, H5AC__NO_FLAGS_SET) < 0)
+                            HGOTO_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, FAIL, "unable to release B-tree node")
+                        grandchild = NULL;
+                    } /* end for */
+                } /* end if */
+            } /* end if */
+
             /* Update the current number of records in middle node */
             curr_middle_nrec = (uint16_t)(curr_middle_nrec + left_nrec_move);
 
@@ -922,7 +1462,6 @@ H5B2_redistribute3(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth,
             /* Move node pointers also if this is an internal node */
             if(depth > 1) {
                 hsize_t moved_nrec;         /* Total number of records moved, for internal redistrib */
-                unsigned u;             /* Local index variable */
 
                 /* Move right node pointers into middle node */
                 HDmemcpy(&(middle_node_ptrs[curr_middle_nrec + 1]), &(right_node_ptrs[0]), sizeof(H5B2_node_ptr_t) * right_nrec_move);
@@ -937,6 +1476,80 @@ H5B2_redistribute3(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth,
                 HDmemmove(&(right_node_ptrs[0]), &(right_node_ptrs[right_nrec_move]), sizeof(H5B2_node_ptr_t) * (size_t)(new_right_nrec + 1));
             } /* end if */
 
+            /* Update flush dependencies */
+            if(hdr->swmr_write) {
+                /* Update dependencies on records */
+                if(hdr->cls->upd_flush_dep) {
+                    /* Update the old parent record */
+                    if(hdr->cls->upd_flush_dep(H5B2_NAT_NREC(middle_native, hdr, curr_middle_nrec), udata, internal, middle_child) < 0)
+                        HGOTO_ERROR(H5E_BTREE, H5E_CANTDEPEND, FAIL, "unable to update flush dependency")
+
+                    /* Update middle child's records moved from right child */
+                    for(u = (curr_middle_nrec + (unsigned)1); u < curr_middle_nrec + right_nrec_move; u++)
+                        if(hdr->cls->upd_flush_dep(H5B2_NAT_NREC(middle_native, hdr, u), udata, right_child, middle_child) < 0)
+                            HGOTO_ERROR(H5E_BTREE, H5E_CANTDEPEND, FAIL, "unable to update flush dependency")
+
+                    /* Update the new parent record */
+                    if(hdr->cls->upd_flush_dep(H5B2_INT_NREC(internal, hdr, idx), udata, right_child, internal) < 0)
+                        HGOTO_ERROR(H5E_BTREE, H5E_CANTDEPEND, FAIL, "unable to update flush dependency")
+                } /* end if */
+
+                /* Update node pointers */
+                if(depth > 1) {
+                    /* Loop over grandchildren */
+                    for(u = (curr_middle_nrec + (unsigned)1); u < (curr_middle_nrec + right_nrec_move + 1); u++) {
+                        hbool_t update_deps = FALSE;    /* Whether to update flush dependencies */
+
+                        grandchild_addr = middle_node_ptrs[u].addr;
+                        if(depth > 2) {
+                            H5B2_internal_t *grandchild_int = NULL;
+
+                            /* Protect grandchild */
+                            if(NULL == (grandchild_int = H5B2_protect_internal(hdr, dxpl_id, grandchild_addr, middle_child, middle_node_ptrs[u].node_nrec, (depth - 2), H5AC_WRITE)))
+                                HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree internal node")
+                            grandchild_class = H5AC_BT2_INT;
+                            grandchild = grandchild_int;
+
+                            if(grandchild_int->parent == right_child) {
+                                grandchild_int->parent = middle_child;
+                                update_deps = TRUE;
+                            } /* end if */
+                            else
+                                HDassert(grandchild_int->parent == middle_child);
+                        } /* end if */
+                        else {
+                            H5B2_leaf_t *grandchild_leaf = NULL;
+
+                            /* Protect grandchild */
+                            if(NULL == (grandchild_leaf = H5B2_protect_leaf(hdr, dxpl_id, grandchild_addr, middle_child, middle_node_ptrs[u].node_nrec, H5AC_WRITE)))
+                                HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree leaf node")
+                            grandchild_class = H5AC_BT2_LEAF;
+                            grandchild = grandchild_leaf;
+
+                            if(grandchild_leaf->parent == right_child) {
+                                grandchild_leaf->parent = middle_child;
+                                update_deps = TRUE;
+                            } /* end if */
+                            else
+                                HDassert(grandchild_leaf->parent == middle_child);
+                        } /* end else */
+
+                        /* Update flush dependencies if necessary */
+                        if(update_deps) {
+                            if(H5AC_destroy_flush_dependency(right_child, grandchild) < 0)
+                                HGOTO_ERROR(H5E_BTREE, H5E_CANTUNDEPEND, FAIL, "unable to destroy flush dependency")
+                            if(H5AC_create_flush_dependency(middle_child, grandchild) < 0)
+                                HGOTO_ERROR(H5E_BTREE, H5E_CANTDEPEND, FAIL, "unable to create flush dependency")
+                        } /* end if */
+
+                        /* Unprotect the grandchild */
+                        if(H5AC_unprotect(hdr->f, dxpl_id, grandchild_class, middle_node_ptrs[u].addr, grandchild, H5AC__NO_FLAGS_SET) < 0)
+                            HGOTO_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, FAIL, "unable to release B-tree node")
+                        grandchild = NULL;
+                    } /* end for */
+                } /* end if */
+            } /* end if */
+
             /* Mark nodes as dirty */
             middle_child_flags |= H5AC__DIRTIED_FLAG;
             right_child_flags |= H5AC__DIRTIED_FLAG;
@@ -1032,6 +1645,13 @@ done:
     if(right_child && H5AC_unprotect(hdr->f, dxpl_id, child_class, right_addr, right_child, right_child_flags) < 0)
         HDONE_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, FAIL, "unable to release B-tree child node")
 
+    /* Unprotect the grandchild on error */
+    if(grandchild) {
+        HDassert(ret_value < 0);
+        if(H5AC_unprotect(hdr->f, dxpl_id, grandchild_class, grandchild_addr, grandchild, H5AC__NO_FLAGS_SET) < 0)
+            HGOTO_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, FAIL, "unable to release B-tree node")
+    } /* end if */
+
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5B2_redistribute3 */
 
@@ -1054,15 +1674,20 @@ done:
 static herr_t
 H5B2_merge2(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth,
     H5B2_node_ptr_t *curr_node_ptr, unsigned *parent_cache_info_flags_ptr,
-    H5B2_internal_t *internal, unsigned *internal_flags_ptr, unsigned idx)
+    H5B2_internal_t *internal, unsigned *internal_flags_ptr, unsigned idx,
+    void *udata)
 {
     const H5AC_class_t *child_class;    /* Pointer to child node's class info */
     haddr_t left_addr, right_addr;      /* Addresses of left & right child nodes */
     void *left_child = NULL, *right_child = NULL;     /* Pointers to left & right child nodes */
+    const H5AC_class_t *grandchild_class; /* Pointer to grandchild node's class info */
+    haddr_t grandchild_addr;            /* Grandchild address */
+    void *grandchild = NULL;            /* Pointer to grandchild node */
     uint16_t *left_nrec, *right_nrec;   /* Pointers to left & right child # of records */
     uint8_t *left_native, *right_native;    /* Pointers to left & right children's native records */
     H5B2_node_ptr_t *left_node_ptrs = NULL, *right_node_ptrs = NULL;/* Pointers to childs' node pointer info */
     unsigned left_child_flags = H5AC__NO_FLAGS_SET, right_child_flags = H5AC__NO_FLAGS_SET;     /* Flags for unprotecting child nodes */
+    unsigned u;                         /* Local index variable */
     herr_t ret_value = SUCCEED;         /* Return value */
 
     FUNC_ENTER_NOAPI_NOINIT
@@ -1084,11 +1709,18 @@ H5B2_merge2(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth,
         right_addr = internal->node_ptrs[idx + 1].addr;
 
         /* Lock left & right B-tree child nodes */
-        if(NULL == (left_internal = H5B2_protect_internal(hdr, dxpl_id, left_addr, internal->node_ptrs[idx].node_nrec, (depth - 1), H5AC_WRITE)))
+        if(NULL == (left_internal = H5B2_protect_internal(hdr, dxpl_id, left_addr, internal, internal->node_ptrs[idx].node_nrec, (depth - 1), H5AC_WRITE)))
             HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree internal node")
-        if(NULL == (right_internal = H5B2_protect_internal(hdr, dxpl_id, right_addr, internal->node_ptrs[idx + 1].node_nrec, (depth - 1), H5AC_WRITE)))
+        if(NULL == (right_internal = H5B2_protect_internal(hdr, dxpl_id, right_addr, internal, internal->node_ptrs[idx + 1].node_nrec, (depth - 1), H5AC_WRITE)))
             HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree internal node")
 
+        /* Shadow the left node if doing SWMR writes */
+        if(hdr->swmr_write) {
+            if(H5B2_shadow_internal(hdr, dxpl_id, (depth - 1), &(internal->node_ptrs[idx]), &left_internal) < 0)
+                HGOTO_ERROR(H5E_BTREE, H5E_CANTCOPY, FAIL, "unable to shadow internal node")
+            left_addr = internal->node_ptrs[idx].addr;
+        } /* end if */
+
         /* More setup for accessing child node information */
         left_child = left_internal;
         right_child = right_internal;
@@ -1109,11 +1741,18 @@ H5B2_merge2(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth,
         right_addr = internal->node_ptrs[idx + 1].addr;
 
         /* Lock left & right B-tree child nodes */
-        if(NULL == (left_leaf = H5B2_protect_leaf(hdr, dxpl_id, left_addr, internal->node_ptrs[idx].node_nrec, H5AC_WRITE)))
+        if(NULL == (left_leaf = H5B2_protect_leaf(hdr, dxpl_id, left_addr, internal, internal->node_ptrs[idx].node_nrec, H5AC_WRITE)))
             HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree leaf node")
-        if(NULL == (right_leaf = H5B2_protect_leaf(hdr, dxpl_id, right_addr, internal->node_ptrs[idx + 1].node_nrec, H5AC_WRITE)))
+        if(NULL == (right_leaf = H5B2_protect_leaf(hdr, dxpl_id, right_addr, internal, internal->node_ptrs[idx + 1].node_nrec, H5AC_WRITE)))
             HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree leaf node")
 
+        /* Shadow the left node if doing SWMR writes */
+        if(hdr->swmr_write) {
+            if(H5B2_shadow_leaf(hdr, dxpl_id, &(internal->node_ptrs[idx]), &left_leaf) < 0)
+                HGOTO_ERROR(H5E_BTREE, H5E_CANTCOPY, FAIL, "unable to shadow leaf node")
+            left_addr = internal->node_ptrs[idx].addr;
+        } /* end if */
+
         /* More setup for accessing child node information */
         left_child = left_leaf;
         right_child = right_leaf;
@@ -1135,12 +1774,84 @@ H5B2_merge2(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth,
         if(depth > 1)
             HDmemcpy(&(left_node_ptrs[*left_nrec + 1]), &(right_node_ptrs[0]), sizeof(H5B2_node_ptr_t) * (size_t)(*right_nrec + 1));
 
+        /* Update flush dependencies */
+        if(hdr->swmr_write) {
+            /* Update dependencies on records */
+            if(hdr->cls->upd_flush_dep) {
+                /* Update the old parent record */
+                if(hdr->cls->upd_flush_dep(H5B2_NAT_NREC(left_native, hdr, *left_nrec), udata, internal, left_child) < 0)
+                    HGOTO_ERROR(H5E_BTREE, H5E_CANTDEPEND, FAIL, "unable to update flush dependency")
+
+                /* Update records moved from right child */
+                for(u = (*left_nrec + (unsigned)1); u < (*left_nrec + (unsigned)*right_nrec + (unsigned)1); u++)
+                    if(hdr->cls->upd_flush_dep(H5B2_NAT_NREC(left_native, hdr, u), udata, right_child, left_child) < 0)
+                        HGOTO_ERROR(H5E_BTREE, H5E_CANTDEPEND, FAIL, "unable to update flush dependency")
+            } /* end if */
+
+            /* Update node pointers */
+            if(depth > 1) {
+                /* Loop over grandchildren */
+                for(u = (*left_nrec + (unsigned)1); u < (*left_nrec + (unsigned)*right_nrec + (unsigned)2); u++) {
+                    hbool_t update_deps = FALSE;    /* Whether to update flush dependencies */
+
+                    grandchild_addr = left_node_ptrs[u].addr;
+                    if(depth > 2) {
+                        H5B2_internal_t *grandchild_int = NULL;
+
+                        /* Protect grandchild */
+                        if(NULL == (grandchild_int = H5B2_protect_internal(hdr, dxpl_id, grandchild_addr, left_child, left_node_ptrs[u].node_nrec, (depth - 2), H5AC_WRITE)))
+                            HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree internal node")
+                        grandchild_class = H5AC_BT2_INT;
+                        grandchild = grandchild_int;
+
+                        if(grandchild_int->parent == right_child) {
+                            grandchild_int->parent = left_child;
+                            update_deps = TRUE;
+                        } /* end if */
+                        else
+                            HDassert(grandchild_int->parent == left_child);
+                    } /* end if */
+                    else {
+                        H5B2_leaf_t *grandchild_leaf = NULL;
+
+                        /* Protect grandchild */
+                        if(NULL == (grandchild_leaf = H5B2_protect_leaf(hdr, dxpl_id, grandchild_addr, left_child, left_node_ptrs[u].node_nrec, H5AC_WRITE)))
+                            HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree leaf node")
+                        grandchild_class = H5AC_BT2_LEAF;
+                        grandchild = grandchild_leaf;
+
+                        if(grandchild_leaf->parent == right_child) {
+                            grandchild_leaf->parent = left_child;
+                            update_deps = TRUE;
+                        } /* end if */
+                        else
+                            HDassert(grandchild_leaf->parent == left_child);
+                    } /* end else */
+
+                    /* Update flush dependencies if necessary */
+                    if(update_deps) {
+                        if(H5AC_destroy_flush_dependency(right_child, grandchild) < 0)
+                            HGOTO_ERROR(H5E_BTREE, H5E_CANTUNDEPEND, FAIL, "unable to destroy flush dependency")
+                        if(H5AC_create_flush_dependency(left_child, grandchild) < 0)
+                            HGOTO_ERROR(H5E_BTREE, H5E_CANTDEPEND, FAIL, "unable to create flush dependency")
+                    } /* end if */
+
+                    /* Unprotect the grandchild */
+                    if(H5AC_unprotect(hdr->f, dxpl_id, grandchild_class, left_node_ptrs[u].addr, grandchild, H5AC__NO_FLAGS_SET) < 0)
+                        HGOTO_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, FAIL, "unable to release B-tree node")
+                    grandchild = NULL;
+                } /* end for */
+            } /* end if */
+        } /* end if */
+
         /* Update # of records in left node */
         *left_nrec = (uint16_t)(*left_nrec + *right_nrec + 1);
 
         /* Mark nodes as dirty */
         left_child_flags |= H5AC__DIRTIED_FLAG;
-        right_child_flags |= H5AC__DIRTIED_FLAG | H5AC__DELETED_FLAG | H5AC__FREE_FILE_SPACE_FLAG;
+        right_child_flags |= H5AC__DELETED_FLAG;
+        if(!(hdr->swmr_write))
+            right_child_flags |= H5AC__DIRTIED_FLAG | H5AC__FREE_FILE_SPACE_FLAG;
     } /* end block */
 
     /* Update # of records in child nodes */
@@ -1185,6 +1896,13 @@ done:
     if(right_child && H5AC_unprotect(hdr->f, dxpl_id, child_class, right_addr, right_child, right_child_flags) < 0)
         HDONE_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, FAIL, "unable to release B-tree child node")
 
+    /* Unprotect the grandchild on error */
+    if(grandchild) {
+        HDassert(ret_value < 0);
+        if(H5AC_unprotect(hdr->f, dxpl_id, grandchild_class, grandchild_addr, grandchild, H5AC__NO_FLAGS_SET) < 0)
+            HGOTO_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, FAIL, "unable to release B-tree node")
+    } /* end if */
+
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5B2_merge2() */
 
@@ -1207,13 +1925,17 @@ done:
 static herr_t
 H5B2_merge3(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth,
     H5B2_node_ptr_t *curr_node_ptr, unsigned *parent_cache_info_flags_ptr,
-    H5B2_internal_t *internal, unsigned *internal_flags_ptr, unsigned idx)
+    H5B2_internal_t *internal, unsigned *internal_flags_ptr, unsigned idx,
+    void *udata)
 {
     const H5AC_class_t *child_class;    /* Pointer to child node's class info */
     haddr_t left_addr, right_addr;      /* Addresses of left & right child nodes */
     haddr_t middle_addr;                /* Address of middle child node */
     void *left_child = NULL, *right_child = NULL;     /* Pointers to left & right child nodes */
     void *middle_child = NULL;          /* Pointer to middle child node */
+    const H5AC_class_t *grandchild_class; /* Pointer to grandchild node's class info */
+    haddr_t grandchild_addr;            /* Grandchild address */
+    void *grandchild = NULL;            /* Pointer to grandchild node */
     uint16_t *left_nrec, *right_nrec;   /* Pointers to left & right child # of records */
     uint16_t *middle_nrec;              /* Pointer to middle child # of records */
     uint8_t *left_native, *right_native;    /* Pointers to left & right children's native records */
@@ -1223,6 +1945,7 @@ H5B2_merge3(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth,
     hsize_t middle_moved_nrec;          /* Number of records moved, for internal split */
     unsigned left_child_flags = H5AC__NO_FLAGS_SET, right_child_flags = H5AC__NO_FLAGS_SET;     /* Flags for unprotecting child nodes */
     unsigned middle_child_flags = H5AC__NO_FLAGS_SET;     /* Flags for unprotecting child nodes */
+    unsigned u;                         /* Local index variable */
     herr_t ret_value = SUCCEED;         /* Return value */
 
     FUNC_ENTER_NOAPI_NOINIT
@@ -1246,13 +1969,23 @@ H5B2_merge3(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth,
         right_addr = internal->node_ptrs[idx + 1].addr;
 
         /* Lock B-tree child nodes */
-        if(NULL == (left_internal = H5B2_protect_internal(hdr, dxpl_id, left_addr, internal->node_ptrs[idx - 1].node_nrec, (depth - 1), H5AC_WRITE)))
+        if(NULL == (left_internal = H5B2_protect_internal(hdr, dxpl_id, left_addr, internal, internal->node_ptrs[idx - 1].node_nrec, (depth - 1), H5AC_WRITE)))
             HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree internal node")
-        if(NULL == (middle_internal = H5B2_protect_internal(hdr, dxpl_id, middle_addr, internal->node_ptrs[idx].node_nrec, (depth - 1), H5AC_WRITE)))
+        if(NULL == (middle_internal = H5B2_protect_internal(hdr, dxpl_id, middle_addr, internal, internal->node_ptrs[idx].node_nrec, (depth - 1), H5AC_WRITE)))
             HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree internal node")
-        if(NULL == (right_internal = H5B2_protect_internal(hdr, dxpl_id, right_addr, internal->node_ptrs[idx + 1].node_nrec, (depth - 1), H5AC_WRITE)))
+        if(NULL == (right_internal = H5B2_protect_internal(hdr, dxpl_id, right_addr, internal, internal->node_ptrs[idx + 1].node_nrec, (depth - 1), H5AC_WRITE)))
             HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree internal node")
 
+        /* Shadow left and middle nodes if doing SWMR writes */
+        if(hdr->swmr_write) {
+            if(H5B2_shadow_internal(hdr, dxpl_id, (depth - 1), &(internal->node_ptrs[idx - 1]), &left_internal) < 0)
+                HGOTO_ERROR(H5E_BTREE, H5E_CANTCOPY, FAIL, "unable to shadow internal node")
+            if(H5B2_shadow_internal(hdr, dxpl_id, (depth - 1), &(internal->node_ptrs[idx]), &middle_internal) < 0)
+                HGOTO_ERROR(H5E_BTREE, H5E_CANTCOPY, FAIL, "unable to shadow internal node")
+            left_addr = internal->node_ptrs[idx - 1].addr;
+            middle_addr = internal->node_ptrs[idx].addr;
+        } /* end if */
+
         /* More setup for accessing child node information */
         left_child = left_internal;
         middle_child = middle_internal;
@@ -1279,13 +2012,23 @@ H5B2_merge3(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth,
         right_addr = internal->node_ptrs[idx + 1].addr;
 
         /* Lock B-tree child nodes */
-        if(NULL == (left_leaf = H5B2_protect_leaf(hdr, dxpl_id, left_addr, internal->node_ptrs[idx - 1].node_nrec, H5AC_WRITE)))
+        if(NULL == (left_leaf = H5B2_protect_leaf(hdr, dxpl_id, left_addr, internal, internal->node_ptrs[idx - 1].node_nrec, H5AC_WRITE)))
             HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree leaf node")
-        if(NULL == (middle_leaf = H5B2_protect_leaf(hdr, dxpl_id, middle_addr, internal->node_ptrs[idx].node_nrec, H5AC_WRITE)))
+        if(NULL == (middle_leaf = H5B2_protect_leaf(hdr, dxpl_id, middle_addr, internal, internal->node_ptrs[idx].node_nrec, H5AC_WRITE)))
             HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree leaf node")
-        if(NULL == (right_leaf = H5B2_protect_leaf(hdr, dxpl_id, right_addr, internal->node_ptrs[idx + 1].node_nrec, H5AC_WRITE)))
+        if(NULL == (right_leaf = H5B2_protect_leaf(hdr, dxpl_id, right_addr, internal, internal->node_ptrs[idx + 1].node_nrec, H5AC_WRITE)))
             HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree leaf node")
 
+        /* Shadow left and middle nodes if doing SWMR writes */
+        if(hdr->swmr_write) {
+            if(H5B2_shadow_leaf(hdr, dxpl_id, &(internal->node_ptrs[idx - 1]), &left_leaf) < 0)
+                HGOTO_ERROR(H5E_BTREE, H5E_CANTCOPY, FAIL, "unable to shadow leaf node")
+            if(H5B2_shadow_leaf(hdr, dxpl_id, &(internal->node_ptrs[idx]), &middle_leaf) < 0)
+                HGOTO_ERROR(H5E_BTREE, H5E_CANTCOPY, FAIL, "unable to shadow leaf node")
+            left_addr = internal->node_ptrs[idx - 1].addr;
+            middle_addr = internal->node_ptrs[idx].addr;
+        } /* end if */
+
         /* More setup for accessing child node information */
         left_child = left_leaf;
         middle_child = middle_leaf;
@@ -1320,7 +2063,6 @@ H5B2_merge3(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth,
 
         /* Move node pointers also if this is an internal node */
         if(depth > 1) {
-            unsigned u;         /* Local index variable */
 
             /* Copy node pointers from middle node into left node */
             HDmemcpy(&(left_node_ptrs[*left_nrec + 1]), &(middle_node_ptrs[0]), sizeof(H5B2_node_ptr_t) * middle_nrec_move);
@@ -1333,6 +2075,80 @@ H5B2_merge3(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth,
             HDmemmove(&(middle_node_ptrs[0]), &(middle_node_ptrs[middle_nrec_move]), sizeof(H5B2_node_ptr_t) * (size_t)((unsigned)(*middle_nrec + 1) - middle_nrec_move));
         } /* end if */
 
+        /* Update flush dependencies */
+        if(hdr->swmr_write) {
+            /* Update dependencies on records */
+            if(hdr->cls->upd_flush_dep) {
+                /* Update the old parent record */
+                if(hdr->cls->upd_flush_dep(H5B2_NAT_NREC(left_native, hdr, *left_nrec), udata, internal, left_child) < 0)
+                    HGOTO_ERROR(H5E_BTREE, H5E_CANTDEPEND, FAIL, "unable to update flush dependency")
+
+                /* Update records moved from middle child */
+                for(u = (*left_nrec + (unsigned)1); u < (*left_nrec + (unsigned)middle_nrec_move); u++)
+                    if(hdr->cls->upd_flush_dep(H5B2_NAT_NREC(left_native, hdr, u), udata, middle_child, left_child) < 0)
+                        HGOTO_ERROR(H5E_BTREE, H5E_CANTDEPEND, FAIL, "unable to update flush dependency")
+
+                /* Update the new parent record */
+                if(hdr->cls->upd_flush_dep(H5B2_INT_NREC(internal, hdr, idx), udata, middle_child, internal) < 0)
+                    HGOTO_ERROR(H5E_BTREE, H5E_CANTDEPEND, FAIL, "unable to update flush dependency")
+            } /* end if */
+
+            /* Update node pointers */
+            if(depth > 1) {
+                /* Loop over grandchildren */
+                for(u = (*left_nrec + (unsigned)1); u < (*left_nrec + (unsigned)middle_nrec_move + (unsigned)1); u++) {
+                    hbool_t update_deps = FALSE;    /* Whether to update flush dependencies */
+
+                    grandchild_addr = left_node_ptrs[u].addr;
+                    if(depth > 2) {
+                        H5B2_internal_t *grandchild_int = NULL;
+
+                        /* Protect grandchild */
+                        if(NULL == (grandchild_int = H5B2_protect_internal(hdr, dxpl_id, grandchild_addr, left_child, left_node_ptrs[u].node_nrec, (depth - 2), H5AC_WRITE)))
+                            HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree internal node")
+                        grandchild_class = H5AC_BT2_INT;
+                        grandchild = grandchild_int;
+
+                        if(grandchild_int->parent == middle_child) {
+                            grandchild_int->parent = left_child;
+                            update_deps = TRUE;
+                        } /* end if */
+                        else
+                            HDassert(grandchild_int->parent == left_child);
+                    } /* end if */
+                    else {
+                        H5B2_leaf_t *grandchild_leaf = NULL;
+
+                        /* Protect grandchild */
+                        if(NULL == (grandchild_leaf = H5B2_protect_leaf(hdr, dxpl_id, grandchild_addr, left_child, left_node_ptrs[u].node_nrec, H5AC_WRITE)))
+                            HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree leaf node")
+                        grandchild_class = H5AC_BT2_LEAF;
+                        grandchild = grandchild_leaf;
+
+                        if(grandchild_leaf->parent == middle_child) {
+                            grandchild_leaf->parent = left_child;
+                            update_deps = TRUE;
+                        } /* end if */
+                        else
+                            HDassert(grandchild_leaf->parent == left_child);
+                    } /* end else */
+
+                    /* Update flush dependencies if necessary */
+                    if(update_deps) {
+                        if(H5AC_destroy_flush_dependency(middle_child, grandchild) < 0)
+                            HGOTO_ERROR(H5E_BTREE, H5E_CANTUNDEPEND, FAIL, "unable to destroy flush dependency")
+                        if(H5AC_create_flush_dependency(left_child, grandchild) < 0)
+                            HGOTO_ERROR(H5E_BTREE, H5E_CANTDEPEND, FAIL, "unable to create flush dependency")
+                    } /* end if */
+
+                    /* Unprotect the grandchild */
+                    if(H5AC_unprotect(hdr->f, dxpl_id, grandchild_class, left_node_ptrs[u].addr, grandchild, H5AC__NO_FLAGS_SET) < 0)
+                        HGOTO_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, FAIL, "unable to release B-tree node")
+                    grandchild = NULL;
+                } /* end for */
+            } /* end if */
+        } /* end if */
+
         /* Update # of records in left & middle nodes */
         *left_nrec = (uint16_t)(*left_nrec + middle_nrec_move);
         *middle_nrec = (uint16_t)(*middle_nrec - middle_nrec_move);
@@ -1355,12 +2171,84 @@ H5B2_merge3(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth,
             /* Copy node pointers from right node into middle node */
             HDmemcpy(&(middle_node_ptrs[*middle_nrec + 1]), &(right_node_ptrs[0]), sizeof(H5B2_node_ptr_t) * (size_t)(*right_nrec + 1));
 
+        /* Update flush dependencies */
+        if(hdr->swmr_write) {
+            /* Update dependencies on records */
+            if(hdr->cls->upd_flush_dep) {
+                /* Update the old parent record */
+                if(hdr->cls->upd_flush_dep(H5B2_NAT_NREC(middle_native, hdr, *middle_nrec), udata, internal, middle_child) < 0)
+                    HGOTO_ERROR(H5E_BTREE, H5E_CANTDEPEND, FAIL, "unable to update flush dependency")
+
+                /* Update records moved from right child */
+                for(u = (*middle_nrec + (unsigned)1); u < (*middle_nrec + (unsigned)*right_nrec + (unsigned)1); u++)
+                    if(hdr->cls->upd_flush_dep(H5B2_NAT_NREC(left_native, hdr, u), udata, right_child, middle_child) < 0)
+                        HGOTO_ERROR(H5E_BTREE, H5E_CANTDEPEND, FAIL, "unable to update flush dependency")
+            } /* end if */
+
+            /* Update node pointers */
+            if(depth > 1) {
+                /* Loop over grandchildren */
+                for(u = (*middle_nrec + (unsigned)1); u < (*middle_nrec + (unsigned)*right_nrec + (unsigned)2); u++) {
+                    hbool_t update_deps = FALSE;    /* Whether to update flush dependencies */
+
+                    grandchild_addr = middle_node_ptrs[u].addr;
+                    if(depth > 2) {
+                        H5B2_internal_t *grandchild_int = NULL;
+
+                        /* Protect grandchild */
+                        if(NULL == (grandchild_int = H5B2_protect_internal(hdr, dxpl_id, grandchild_addr, middle_child, middle_node_ptrs[u].node_nrec, (depth - 2), H5AC_WRITE)))
+                            HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree internal node")
+                        grandchild_class = H5AC_BT2_INT;
+                        grandchild = grandchild_int;
+
+                        if(grandchild_int->parent == right_child) {
+                            grandchild_int->parent = middle_child;
+                            update_deps = TRUE;
+                        } /* end if */
+                        else
+                            HDassert(grandchild_int->parent == middle_child);
+                    } /* end if */
+                    else {
+                        H5B2_leaf_t *grandchild_leaf = NULL;
+
+                        /* Protect grandchild */
+                        if(NULL == (grandchild_leaf = H5B2_protect_leaf(hdr, dxpl_id, grandchild_addr, middle_child, middle_node_ptrs[u].node_nrec, H5AC_WRITE)))
+                            HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree leaf node")
+                        grandchild_class = H5AC_BT2_LEAF;
+                        grandchild = grandchild_leaf;
+
+                        if(grandchild_leaf->parent == right_child) {
+                            grandchild_leaf->parent = middle_child;
+                            update_deps = TRUE;
+                        } /* end if */
+                        else
+                            HDassert(grandchild_leaf->parent == middle_child);
+                    } /* end else */
+
+                    /* Update flush dependencies if necessary */
+                    if(update_deps) {
+                        if(H5AC_destroy_flush_dependency(right_child, grandchild) < 0)
+                            HGOTO_ERROR(H5E_BTREE, H5E_CANTUNDEPEND, FAIL, "unable to destroy flush dependency")
+                        if(H5AC_create_flush_dependency(middle_child, grandchild) < 0)
+                            HGOTO_ERROR(H5E_BTREE, H5E_CANTDEPEND, FAIL, "unable to create flush dependency")
+                    } /* end if */
+
+                    /* Unprotect the grandchild */
+                    if(H5AC_unprotect(hdr->f, dxpl_id, grandchild_class, middle_node_ptrs[u].addr, grandchild, H5AC__NO_FLAGS_SET) < 0)
+                        HGOTO_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, FAIL, "unable to release B-tree node")
+                    grandchild = NULL;
+                } /* end for */
+            } /* end if */
+        } /* end if */
+
         /* Update # of records in middle node */
         *middle_nrec = (uint16_t)(*middle_nrec + (*right_nrec + 1));
 
         /* Mark nodes as dirty */
         middle_child_flags |= H5AC__DIRTIED_FLAG;
-        right_child_flags |= H5AC__DIRTIED_FLAG | H5AC__DELETED_FLAG | H5AC__FREE_FILE_SPACE_FLAG;
+        right_child_flags |= H5AC__DELETED_FLAG;
+        if(!(hdr->swmr_write))
+            right_child_flags |= H5AC__DIRTIED_FLAG | H5AC__FREE_FILE_SPACE_FLAG;
     } /* end block */
 
     /* Update # of records in child nodes */
@@ -1413,6 +2301,13 @@ done:
     if(right_child && H5AC_unprotect(hdr->f, dxpl_id, child_class, right_addr, right_child, right_child_flags) < 0)
         HDONE_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, FAIL, "unable to release B-tree child node")
 
+    /* Unprotect the grandchild on error */
+    if(grandchild) {
+        HDassert(ret_value < 0);
+        if(H5AC_unprotect(hdr->f, dxpl_id, grandchild_class, grandchild_addr, grandchild, H5AC__NO_FLAGS_SET) < 0)
+            HGOTO_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, FAIL, "unable to release B-tree node")
+    } /* end if */
+
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5B2_merge3() */
 
@@ -1435,7 +2330,7 @@ done:
 static herr_t
 H5B2_swap_leaf(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth,
     H5B2_internal_t *internal, unsigned *internal_flags_ptr,
-    unsigned idx, void *swap_loc)
+    unsigned idx, void *swap_loc, void *swap_parent, void *udata)
 {
     const H5AC_class_t *child_class;    /* Pointer to child node's class info */
     haddr_t child_addr;                 /* Address of child node */
@@ -1460,7 +2355,7 @@ H5B2_swap_leaf(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth,
         child_addr = internal->node_ptrs[idx].addr;
 
         /* Lock B-tree child nodes */
-        if(NULL == (child_internal = H5B2_protect_internal(hdr, dxpl_id, child_addr, internal->node_ptrs[idx].node_nrec, (depth - 1), H5AC_WRITE)))
+        if(NULL == (child_internal = H5B2_protect_internal(hdr, dxpl_id, child_addr, internal, internal->node_ptrs[idx].node_nrec, (depth - 1), H5AC_WRITE)))
             HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree internal node")
 
         /* More setup for accessing child node information */
@@ -1475,7 +2370,7 @@ H5B2_swap_leaf(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth,
         child_addr = internal->node_ptrs[idx].addr;
 
         /* Lock B-tree child node */
-        if(NULL == (child_leaf = H5B2_protect_leaf(hdr, dxpl_id, child_addr, internal->node_ptrs[idx].node_nrec, H5AC_WRITE)))
+        if(NULL == (child_leaf = H5B2_protect_leaf(hdr, dxpl_id, child_addr, internal, internal->node_ptrs[idx].node_nrec, H5AC_WRITE)))
             HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree leaf node")
 
         /* More setup for accessing child node information */
@@ -1488,6 +2383,14 @@ H5B2_swap_leaf(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth,
     HDmemcpy(H5B2_NAT_NREC(child_native, hdr, 0), swap_loc, hdr->cls->nrec_size);
     HDmemcpy(swap_loc, hdr->page, hdr->cls->nrec_size);
 
+    /* Update flush dependencies */
+    if(hdr->swmr_write && hdr->cls->upd_flush_dep) {
+        if(hdr->cls->upd_flush_dep(H5B2_NAT_NREC(child_native, hdr, 0), udata, swap_parent, child) < 0)
+            HGOTO_ERROR(H5E_BTREE, H5E_CANTDEPEND, FAIL, "unable to update flush dependency")
+        if(hdr->cls->upd_flush_dep(swap_loc, udata, child, swap_parent) < 0)
+            HGOTO_ERROR(H5E_BTREE, H5E_CANTDEPEND, FAIL, "unable to update flush dependency")
+    } /* end if */
+
     /* Mark parent as dirty */
     *internal_flags_ptr |= H5AC__DIRTIED_FLAG;
 
@@ -1523,7 +2426,7 @@ done:
  */
 herr_t
 H5B2_insert_leaf(H5B2_hdr_t *hdr, hid_t dxpl_id, H5B2_node_ptr_t *curr_node_ptr,
-    void *udata)
+    void *parent, void *udata)
 {
     H5B2_leaf_t *leaf;                  /* Pointer to leaf node */
     int         cmp;                    /* Comparison value of records */
@@ -1538,9 +2441,14 @@ H5B2_insert_leaf(H5B2_hdr_t *hdr, hid_t dxpl_id, H5B2_node_ptr_t *curr_node_ptr,
     HDassert(H5F_addr_defined(curr_node_ptr->addr));
 
     /* Lock current B-tree node */
-    if(NULL == (leaf = H5B2_protect_leaf(hdr, dxpl_id, curr_node_ptr->addr, curr_node_ptr->node_nrec, H5AC_WRITE)))
+    if(NULL == (leaf = H5B2_protect_leaf(hdr, dxpl_id, curr_node_ptr->addr, parent, curr_node_ptr->node_nrec, H5AC_WRITE)))
         HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree leaf node")
 
+    /* Shadow the node if doing SWMR writes */
+    if(hdr->swmr_write)
+        if(H5B2_shadow_leaf(hdr, dxpl_id, curr_node_ptr, &leaf) < 0)
+            HGOTO_ERROR(H5E_BTREE, H5E_CANTCOPY, FAIL, "unable to shadow leaf node")
+
     /* Must have a leaf node with enough space to insert a record now */
     HDassert(curr_node_ptr->node_nrec < hdr->node_info[0].max_nrec);
 
@@ -1567,6 +2475,11 @@ H5B2_insert_leaf(H5B2_hdr_t *hdr, hid_t dxpl_id, H5B2_node_ptr_t *curr_node_ptr,
     if((hdr->cls->store)(H5B2_LEAF_NREC(leaf, hdr, idx), udata) < 0)
         HGOTO_ERROR(H5E_BTREE, H5E_CANTINSERT, FAIL, "unable to insert record into leaf node")
 
+    /* Set up flush dependency on child client object, if appropriate */
+    if(hdr->swmr_write && hdr->cls->crt_flush_dep)
+        if((hdr->cls->crt_flush_dep)(H5B2_LEAF_NREC(leaf, hdr, idx), udata, leaf) < 0)
+            HGOTO_ERROR(H5E_BTREE, H5E_CANTDEPEND, FAIL, "unable to create flush dependency")
+
     /* Update record count for node pointer to current node */
     curr_node_ptr->all_nrec++;
     curr_node_ptr->node_nrec++;
@@ -1577,7 +2490,7 @@ H5B2_insert_leaf(H5B2_hdr_t *hdr, hid_t dxpl_id, H5B2_node_ptr_t *curr_node_ptr,
 done:
     /* Release the B-tree leaf node (marked as dirty) */
     if(leaf && H5AC_unprotect(hdr->f, dxpl_id, H5AC_BT2_LEAF, curr_node_ptr->addr, leaf, H5AC__DIRTIED_FLAG) < 0)
-        HDONE_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, FAIL, "unable to release leaf B-tree node")
+        HDONE_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, FAIL, "unable to release leaf B-tree node")\
 
     FUNC_LEAVE_NOAPI(ret_value)
 } /* H5B2_insert_leaf() */
@@ -1599,9 +2512,9 @@ done:
 herr_t
 H5B2_insert_internal(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth,
     unsigned *parent_cache_info_flags_ptr, H5B2_node_ptr_t *curr_node_ptr,
-    void *udata)
+    void *parent, void *udata)
 {
-    H5B2_internal_t *internal;          /* Pointer to internal node */
+    H5B2_internal_t *internal = NULL;   /* Pointer to internal node */
     unsigned internal_flags = H5AC__NO_FLAGS_SET;
     unsigned    idx;                    /* Location of record which matches key */
     herr_t	ret_value = SUCCEED;    /* Return value */
@@ -1615,10 +2528,15 @@ H5B2_insert_internal(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth,
     HDassert(H5F_addr_defined(curr_node_ptr->addr));
 
     /* Lock current B-tree node */
-    if(NULL == (internal = H5B2_protect_internal(hdr, dxpl_id, curr_node_ptr->addr, curr_node_ptr->node_nrec, depth, H5AC_WRITE)))
+    if(NULL == (internal = H5B2_protect_internal(hdr, dxpl_id, curr_node_ptr->addr, parent, curr_node_ptr->node_nrec, depth, H5AC_WRITE)))
         HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree internal node")
 
-/* Split or redistribute child node pointers, if necessary */
+    /* Shadow the node if doing SWMR writes */
+    if(hdr->swmr_write)
+        if(H5B2_shadow_internal(hdr, dxpl_id, depth, curr_node_ptr, &internal) < 0)
+            HGOTO_ERROR(H5E_BTREE, H5E_CANTCOPY, FAIL, "unable to shadow internal node")
+
+    /* Split or redistribute child node pointers, if necessary */
     {
         int         cmp;        /* Comparison value of records */
         unsigned retries;       /* Number of times to attempt redistribution */
@@ -1646,35 +2564,35 @@ H5B2_insert_internal(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth,
             /* Attempt to redistribute records among children */
             if(idx == 0) {    /* Left-most child */
                 if(retries > 0 && (internal->node_ptrs[idx + 1].node_nrec < split_nrec)) {
-                    if(H5B2_redistribute2(hdr, dxpl_id, depth, internal, idx) < 0)
+                    if(H5B2_redistribute2(hdr, dxpl_id, depth, internal, idx, udata) < 0)
                         HGOTO_ERROR(H5E_BTREE, H5E_CANTREDISTRIBUTE, FAIL, "unable to redistribute child node records")
                 } /* end if */
                 else {
                     if(H5B2_split1(hdr, dxpl_id, depth, curr_node_ptr,
-                           parent_cache_info_flags_ptr, internal, &internal_flags, idx) < 0)
+                           parent_cache_info_flags_ptr, internal, &internal_flags, idx, udata) < 0)
                         HGOTO_ERROR(H5E_BTREE, H5E_CANTSPLIT, FAIL, "unable to split child node")
                 } /* end else */
             } /* end if */
             else if(idx == internal->nrec) { /* Right-most child */
                 if(retries > 0 && (internal->node_ptrs[idx - 1].node_nrec < split_nrec)) {
-                    if(H5B2_redistribute2(hdr, dxpl_id, depth, internal, (idx - 1)) < 0)
+                    if(H5B2_redistribute2(hdr, dxpl_id, depth, internal, (idx - 1), udata) < 0)
                         HGOTO_ERROR(H5E_BTREE, H5E_CANTREDISTRIBUTE, FAIL, "unable to redistribute child node records")
                 } /* end if */
                 else {
                     if(H5B2_split1(hdr, dxpl_id, depth, curr_node_ptr,
-                           parent_cache_info_flags_ptr, internal, &internal_flags, idx) < 0)
+                           parent_cache_info_flags_ptr, internal, &internal_flags, idx, udata) < 0)
                         HGOTO_ERROR(H5E_BTREE, H5E_CANTSPLIT, FAIL, "unable to split child node")
                 } /* end else */
             } /* end if */
             else { /* Middle child */
                 if(retries > 0 && ((internal->node_ptrs[idx + 1].node_nrec < split_nrec) ||
                             (internal->node_ptrs[idx - 1].node_nrec < split_nrec))) {
-                    if(H5B2_redistribute3(hdr, dxpl_id, depth, internal, &internal_flags, idx) < 0)
+                    if(H5B2_redistribute3(hdr, dxpl_id, depth, internal, &internal_flags, idx, udata) < 0)
                         HGOTO_ERROR(H5E_BTREE, H5E_CANTREDISTRIBUTE, FAIL, "unable to redistribute child node records")
                 } /* end if */
                 else {
                     if(H5B2_split1(hdr, dxpl_id, depth, curr_node_ptr,
-                           parent_cache_info_flags_ptr, internal, &internal_flags, idx) < 0)
+                           parent_cache_info_flags_ptr, internal, &internal_flags, idx, udata) < 0)
                         HGOTO_ERROR(H5E_BTREE, H5E_CANTSPLIT, FAIL, "unable to split child node")
                 } /* end else */
             } /* end else */
@@ -1693,11 +2611,11 @@ H5B2_insert_internal(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth,
 
     /* Attempt to insert node */
     if(depth > 1) {
-        if(H5B2_insert_internal(hdr, dxpl_id, (depth - 1), &internal_flags, &internal->node_ptrs[idx], udata) < 0)
+        if(H5B2_insert_internal(hdr, dxpl_id, (depth - 1), &internal_flags, &internal->node_ptrs[idx], internal, udata) < 0)
             HGOTO_ERROR(H5E_BTREE, H5E_CANTINSERT, FAIL, "unable to insert record into B-tree internal node")
     } /* end if */
     else {
-        if(H5B2_insert_leaf(hdr, dxpl_id, &internal->node_ptrs[idx], udata) < 0)
+        if(H5B2_insert_leaf(hdr, dxpl_id, &internal->node_ptrs[idx], internal, udata) < 0)
             HGOTO_ERROR(H5E_BTREE, H5E_CANTINSERT, FAIL, "unable to insert record into B-tree leaf node")
     } /* end else */
 
@@ -1731,7 +2649,7 @@ done:
  *-------------------------------------------------------------------------
  */
 herr_t
-H5B2_create_leaf(H5B2_hdr_t *hdr, hid_t dxpl_id, H5B2_node_ptr_t *node_ptr)
+H5B2_create_leaf(H5B2_hdr_t *hdr, hid_t dxpl_id, void *parent, H5B2_node_ptr_t *node_ptr)
 {
     H5B2_leaf_t *leaf = NULL;           /* Pointer to new leaf node created */
     herr_t ret_value = SUCCEED;         /* Return value */
@@ -1766,6 +2684,12 @@ HDmemset(leaf->leaf_native, 0, hdr->cls->nrec_size * hdr->node_info[0].max_nrec)
     /* Set number of records */
     leaf->nrec = 0;
 
+    /* Set parent */
+    leaf->parent = parent;
+
+    /* Set shadowed list next pointer */
+    leaf->shadowed_next = NULL;
+
     /* Allocate space on disk for the leaf */
     if(HADDR_UNDEF == (node_ptr->addr = H5MF_alloc(hdr->f, H5FD_MEM_BTREE, dxpl_id, (hsize_t)hdr->node_size)))
 	HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "file allocation failed for B-tree leaf node")
@@ -1799,8 +2723,8 @@ done:
  *-------------------------------------------------------------------------
  */
 H5B2_leaf_t *
-H5B2_protect_leaf(H5B2_hdr_t *hdr, hid_t dxpl_id, haddr_t addr, unsigned nrec,
-    H5AC_protect_t rw)
+H5B2_protect_leaf(H5B2_hdr_t *hdr, hid_t dxpl_id, haddr_t addr, void *parent,
+    unsigned nrec, H5AC_protect_t rw)
 {
     H5B2_leaf_cache_ud_t udata;         /* User-data for callback */
     H5B2_leaf_t *ret_value;             /* Return value */
@@ -1814,6 +2738,7 @@ H5B2_protect_leaf(H5B2_hdr_t *hdr, hid_t dxpl_id, haddr_t addr, unsigned nrec,
     /* Set up user data for callback */
     udata.f = hdr->f;
     udata.hdr = hdr;
+    udata.parent = parent;
     H5_ASSIGN_OVERFLOW(/* To: */ udata.nrec, /* From: */ nrec, /* From: */ unsigned, /* To: */ uint16_t)
 
     /* Protect the leaf node */
@@ -1840,8 +2765,8 @@ done:
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5B2_create_internal(H5B2_hdr_t *hdr, hid_t dxpl_id, H5B2_node_ptr_t *node_ptr,
-    unsigned depth)
+H5B2_create_internal(H5B2_hdr_t *hdr, hid_t dxpl_id, void *parent,
+    H5B2_node_ptr_t *node_ptr, unsigned depth)
 {
     H5B2_internal_t *internal = NULL;   /* Pointer to new internal node created */
     herr_t	ret_value = SUCCEED;    /* Return value */
@@ -1885,6 +2810,12 @@ HDmemset(internal->node_ptrs, 0, sizeof(H5B2_node_ptr_t) * (hdr->node_info[depth
     internal->nrec = 0;
     internal->depth = (uint16_t)depth;
 
+    /* Set parent */
+    internal->parent = parent;
+
+    /* Set shadowed list next pointer */
+    internal->shadowed_next = NULL;
+
     /* Allocate space on disk for the internal node */
     if(HADDR_UNDEF == (node_ptr->addr = H5MF_alloc(hdr->f, H5FD_MEM_BTREE, dxpl_id, (hsize_t)hdr->node_size)))
 	HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "file allocation failed for B-tree internal node")
@@ -1919,7 +2850,7 @@ done:
  */
 H5B2_internal_t *
 H5B2_protect_internal(H5B2_hdr_t *hdr, hid_t dxpl_id, haddr_t addr,
-    unsigned nrec, unsigned depth, H5AC_protect_t rw)
+    void *parent, unsigned nrec, unsigned depth, H5AC_protect_t rw)
 {
     H5B2_internal_cache_ud_t udata;     /* User data to pass through to cache 'deserialize' callback */
     H5B2_internal_t *ret_value;         /* Return value */
@@ -1934,6 +2865,7 @@ H5B2_protect_internal(H5B2_hdr_t *hdr, hid_t dxpl_id, haddr_t addr,
     /* Set up user data for callback */
     udata.f = hdr->f;
     udata.hdr = hdr;
+    udata.parent = parent;
     H5_ASSIGN_OVERFLOW(/* To: */ udata.nrec, /* From: */ nrec, /* From: */ unsigned, /* To: */ uint16_t)
     H5_ASSIGN_OVERFLOW(/* To: */ udata.depth, /* From: */ depth, /* From: */ unsigned, /* To: */ uint16_t)
 
@@ -1965,13 +2897,15 @@ done:
  */
 herr_t
 H5B2_iterate_node(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth,
-    const H5B2_node_ptr_t *curr_node, H5B2_operator_t op, void *op_data)
+    const H5B2_node_ptr_t *curr_node, void *parent, H5B2_operator_t op,
+    void *op_data)
 {
     const H5AC_class_t *curr_node_class = NULL; /* Pointer to current node's class info */
     void *node = NULL;                  /* Pointers to current node */
     uint8_t *node_native;               /* Pointers to node's native records */
     uint8_t *native = NULL;             /* Pointers to copy of node's native records */
     H5B2_node_ptr_t *node_ptrs = NULL;  /* Pointers to node's node pointers */
+    hbool_t node_pinned = FALSE;        /* Whether node is pinned */
     unsigned u;                         /* Local index */
     herr_t ret_value = H5_ITER_CONT;    /* Iterator return value */
 
@@ -1987,7 +2921,7 @@ H5B2_iterate_node(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth,
         H5B2_internal_t *internal;     /* Pointer to internal node */
 
         /* Lock the current B-tree node */
-        if(NULL == (internal = H5B2_protect_internal(hdr, dxpl_id, curr_node->addr, curr_node->node_nrec, depth, H5AC_READ)))
+        if(NULL == (internal = H5B2_protect_internal(hdr, dxpl_id, curr_node->addr, parent, curr_node->node_nrec, depth, H5AC_READ)))
             HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree internal node")
 
         /* Set up information about current node */
@@ -2006,7 +2940,7 @@ H5B2_iterate_node(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth,
         H5B2_leaf_t *leaf;             /* Pointer to leaf node */
 
         /* Lock the current B-tree node */
-        if(NULL == (leaf = H5B2_protect_leaf(hdr, dxpl_id, curr_node->addr, curr_node->node_nrec, H5AC_READ)))
+        if(NULL == (leaf = H5B2_protect_leaf(hdr, dxpl_id, curr_node->addr, parent, curr_node->node_nrec, H5AC_READ)))
             HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree leaf node")
 
         /* Set up information about current node */
@@ -2023,15 +2957,18 @@ H5B2_iterate_node(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth,
     HDmemcpy(native, node_native, (hdr->cls->nrec_size * curr_node->node_nrec));
 
     /* Unlock the node */
-    if(H5AC_unprotect(hdr->f, dxpl_id, curr_node_class, curr_node->addr, node, H5AC__NO_FLAGS_SET) < 0)
+    if(H5AC_unprotect(hdr->f, dxpl_id, curr_node_class, curr_node->addr, node, hdr->swmr_write ? H5AC__PIN_ENTRY_FLAG : H5AC__NO_FLAGS_SET) < 0)
         HGOTO_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, FAIL, "unable to release B-tree node")
-    node = NULL;
+    if(hdr->swmr_write)
+        node_pinned = TRUE;
+    else
+        node = NULL;
 
     /* Iterate through records, in order */
     for(u = 0; u < curr_node->node_nrec && !ret_value; u++) {
         /* Descend into child node, if current node is an internal node */
         if(depth > 0) {
-            if((ret_value = H5B2_iterate_node(hdr, dxpl_id, (depth - 1), &(node_ptrs[u]), op, op_data)) < 0)
+            if((ret_value = H5B2_iterate_node(hdr, dxpl_id, (depth - 1), &(node_ptrs[u]), node, op, op_data)) < 0)
                 HERROR(H5E_BTREE, H5E_CANTLIST, "node iteration failed");
         } /* end if */
 
@@ -2044,11 +2981,15 @@ H5B2_iterate_node(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth,
 
     /* Descend into last child node, if current node is an internal node */
     if(!ret_value && depth > 0) {
-        if((ret_value = H5B2_iterate_node(hdr, dxpl_id, (depth - 1), &(node_ptrs[u]), op, op_data)) < 0)
+        if((ret_value = H5B2_iterate_node(hdr, dxpl_id, (depth - 1), &(node_ptrs[u]), node, op, op_data)) < 0)
             HERROR(H5E_BTREE, H5E_CANTLIST, "node iteration failed");
     } /* end if */
 
 done:
+    /* Unpin the node if it was pinned */
+    if(node_pinned && H5AC_unpin_entry(node) < 0)
+        HDONE_ERROR(H5E_BTREE, H5E_CANTUNPIN, FAIL, "can't unpin node")
+
     /* Release the node pointers & native records, if they were copied */
     if(node_ptrs)
         node_ptrs = (H5B2_node_ptr_t *)H5FL_FAC_FREE(hdr->node_info[depth].node_ptr_fac, node_ptrs);
@@ -2074,7 +3015,7 @@ done:
  */
 herr_t
 H5B2_remove_leaf(H5B2_hdr_t *hdr, hid_t dxpl_id, H5B2_node_ptr_t *curr_node_ptr,
-    void *udata, H5B2_remove_t op, void *op_data)
+    void *parent, void *udata, H5B2_remove_t op, void *op_data)
 {
     H5B2_leaf_t *leaf;                  /* Pointer to leaf node */
     haddr_t     leaf_addr = HADDR_UNDEF;  /* Leaf address on disk */
@@ -2091,7 +3032,7 @@ H5B2_remove_leaf(H5B2_hdr_t *hdr, hid_t dxpl_id, H5B2_node_ptr_t *curr_node_ptr,
 
     /* Lock current B-tree node */
     leaf_addr = curr_node_ptr->addr;
-    if(NULL == (leaf = H5B2_protect_leaf(hdr, dxpl_id, leaf_addr, curr_node_ptr->node_nrec, H5AC_WRITE)))
+    if(NULL == (leaf = H5B2_protect_leaf(hdr, dxpl_id, leaf_addr, parent, curr_node_ptr->node_nrec, H5AC_WRITE)))
         HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree leaf node")
 
     /* Sanity check number of records */
@@ -2110,17 +3051,26 @@ H5B2_remove_leaf(H5B2_hdr_t *hdr, hid_t dxpl_id, H5B2_node_ptr_t *curr_node_ptr,
     /* Update number of records in node */
     leaf->nrec--;
 
-    /* Mark leaf node as dirty also */
-    leaf_flags |= H5AC__DIRTIED_FLAG;
-
     if(leaf->nrec > 0) {
+        /* Shadow the node if doing SWMR writes */
+        if(hdr->swmr_write) {
+            if(H5B2_shadow_leaf(hdr, dxpl_id, curr_node_ptr, &leaf) < 0)
+                HGOTO_ERROR(H5E_BTREE, H5E_CANTCOPY, FAIL, "unable to shadow leaf node")
+            leaf_addr = curr_node_ptr->addr;
+        } /* end if */
+
         /* Pack record out of leaf */
         if(idx < leaf->nrec)
             HDmemmove(H5B2_LEAF_NREC(leaf, hdr, idx), H5B2_LEAF_NREC(leaf, hdr, (idx + 1)), hdr->cls->nrec_size * (leaf->nrec - idx));
+
+        /* Mark leaf node as dirty also */
+        leaf_flags |= H5AC__DIRTIED_FLAG;
     } /* end if */
     else {
         /* Let the cache know that the object is deleted */
-        leaf_flags |= H5AC__DELETED_FLAG | H5AC__FREE_FILE_SPACE_FLAG;
+        leaf_flags |= H5AC__DELETED_FLAG;
+        if(!hdr->swmr_write)
+            leaf_flags |= H5AC__DIRTIED_FLAG | H5AC__FREE_FILE_SPACE_FLAG;
 
         /* Reset address of parent node pointer */
         curr_node_ptr->addr = HADDR_UNDEF;
@@ -2153,7 +3103,7 @@ done:
  */
 herr_t
 H5B2_remove_internal(H5B2_hdr_t *hdr, hid_t dxpl_id, hbool_t *depth_decreased,
-    void *swap_loc, unsigned depth, H5AC_info_t *parent_cache_info,
+    void *swap_loc, void *swap_parent, unsigned depth, H5AC_info_t *parent_cache_info,
     unsigned *parent_cache_info_flags_ptr, H5B2_node_ptr_t *curr_node_ptr,
     void *udata, H5B2_remove_t op, void *op_data)
 {
@@ -2161,6 +3111,8 @@ H5B2_remove_internal(H5B2_hdr_t *hdr, hid_t dxpl_id, hbool_t *depth_decreased,
     unsigned *new_cache_info_flags_ptr = NULL;
     H5B2_node_ptr_t *new_node_ptr;      /* Pointer to new node pointer */
     H5B2_internal_t *internal;          /* Pointer to internal node */
+    const H5AC_class_t *new_root_class; /* Pointer to new root node's class info */
+    void *new_root = NULL;              /* Pointer to new root node (if old root collapsed) */
     unsigned internal_flags = H5AC__NO_FLAGS_SET;
     haddr_t internal_addr;              /* Address of internal node */
     size_t      merge_nrec;             /* Number of records to merge node at */
@@ -2178,7 +3130,7 @@ H5B2_remove_internal(H5B2_hdr_t *hdr, hid_t dxpl_id, hbool_t *depth_decreased,
 
     /* Lock current B-tree node */
     internal_addr = curr_node_ptr->addr;
-    if(NULL == (internal = H5B2_protect_internal(hdr, dxpl_id, internal_addr, curr_node_ptr->node_nrec, depth, H5AC_WRITE)))
+    if(NULL == (internal = H5B2_protect_internal(hdr, dxpl_id, internal_addr, parent_cache_info, curr_node_ptr->node_nrec, depth, H5AC_WRITE)))
         HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree internal node")
 
     /* Determine the correct number of records to merge at */
@@ -2191,16 +3143,71 @@ H5B2_remove_internal(H5B2_hdr_t *hdr, hid_t dxpl_id, hbool_t *depth_decreased,
 
         /* Merge children of root node */
         if(H5B2_merge2(hdr, dxpl_id, depth, curr_node_ptr,
-                parent_cache_info_flags_ptr, internal, &internal_flags, 0) < 0)
+                parent_cache_info_flags_ptr, internal, &internal_flags, 0,
+                udata) < 0)
             HGOTO_ERROR(H5E_BTREE, H5E_CANTSPLIT, FAIL, "unable to merge child node")
 
         /* Let the cache know that the object is deleted */
-        internal_flags |= H5AC__DELETED_FLAG | H5AC__FREE_FILE_SPACE_FLAG;
+        internal_flags |= H5AC__DELETED_FLAG;
+        if(!hdr->swmr_write)
+            internal_flags |= H5AC__FREE_FILE_SPACE_FLAG;
 
         /* Reset information in header's root node pointer */
         curr_node_ptr->addr = internal->node_ptrs[0].addr;
         curr_node_ptr->node_nrec = internal->node_ptrs[0].node_nrec;
 
+        /* Update flush dependencies */
+        if(hdr->swmr_write) {
+            hbool_t update_dep = FALSE; /* Whether to update root flush dependency */
+
+            /* Update hdr to root dependency */
+            if(depth > 1) {
+                H5B2_internal_t *new_root_int = NULL;
+
+                /* Protect new root */
+                if(NULL == (new_root_int = H5B2_protect_internal(hdr, dxpl_id, curr_node_ptr->addr, hdr, curr_node_ptr->node_nrec, (depth - 1), H5AC_WRITE)))
+                    HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree internal node")
+                new_root_class = H5AC_BT2_INT;
+                new_root = new_root_int;
+
+                if(new_root_int->parent == internal) {
+                    new_root_int->parent = hdr;
+                    update_dep = TRUE;
+                } /* end if */
+                else
+                    HDassert(new_root_int->parent == hdr);
+            } /* end if */
+            else {
+                H5B2_leaf_t *new_root_leaf = NULL;
+
+                /* Protect new root */
+                if(NULL == (new_root_leaf = H5B2_protect_leaf(hdr, dxpl_id, curr_node_ptr->addr, hdr, curr_node_ptr->node_nrec, H5AC_WRITE)))
+                    HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree leaf node")
+                new_root_class = H5AC_BT2_LEAF;
+                new_root = new_root_leaf;
+
+                if(new_root_leaf->parent == internal) {
+                    new_root_leaf->parent = hdr;
+                    update_dep = TRUE;
+                } /* end if */
+                else
+                    HDassert(new_root_leaf->parent == hdr);
+            } /* end else */
+
+            /* Update flush dependency if necessary */
+            if(update_dep) {
+                if(H5AC_destroy_flush_dependency(internal, new_root) < 0)
+                    HGOTO_ERROR(H5E_BTREE, H5E_CANTUNDEPEND, FAIL, "unable to destroy flush dependency")
+                if(H5AC_create_flush_dependency(hdr, new_root) < 0)
+                    HGOTO_ERROR(H5E_BTREE, H5E_CANTDEPEND, FAIL, "unable to create flush dependency")
+            } /* end if */
+
+            /* Unprotect the new root */
+            if(H5AC_unprotect(hdr->f, dxpl_id, new_root_class, curr_node_ptr->addr, new_root, H5AC__NO_FLAGS_SET) < 0)
+                HGOTO_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, FAIL, "unable to release B-tree node")
+            new_root = NULL;
+        } /* end if */
+
         /* Indicate that the level of the B-tree decreased */
         *depth_decreased = TRUE;
 
@@ -2218,6 +3225,13 @@ H5B2_remove_internal(H5B2_hdr_t *hdr, hid_t dxpl_id, hbool_t *depth_decreased,
         int cmp = 0;            /* Comparison value of records */
         unsigned retries;       /* Number of times to attempt redistribution */
 
+        /* Shadow the node if doing SWMR writes */
+        if(hdr->swmr_write) {
+            if(H5B2_shadow_internal(hdr, dxpl_id, depth, curr_node_ptr, &internal) < 0)
+                HGOTO_ERROR(H5E_BTREE, H5E_CANTCOPY, FAIL, "unable to shadow internal node")
+            internal_addr = curr_node_ptr->addr;
+        } /* end if */
+
         /* Locate node pointer for child */
         if(swap_loc)
             idx = 0;
@@ -2246,35 +3260,38 @@ H5B2_remove_internal(H5B2_hdr_t *hdr, hid_t dxpl_id, hbool_t *depth_decreased,
              */
             if(idx == 0) {    /* Left-most child */
                 if(retries > 0 && (internal->node_ptrs[idx + 1].node_nrec > merge_nrec)) {
-                    if(H5B2_redistribute2(hdr, dxpl_id, depth, internal, idx) < 0)
+                    if(H5B2_redistribute2(hdr, dxpl_id, depth, internal, idx, udata) < 0)
                         HGOTO_ERROR(H5E_BTREE, H5E_CANTREDISTRIBUTE, FAIL, "unable to redistribute child node records")
                 } /* end if */
                 else {
                     if(H5B2_merge2(hdr, dxpl_id, depth, curr_node_ptr,
-                           parent_cache_info_flags_ptr, internal, &internal_flags, idx) < 0)
+                           parent_cache_info_flags_ptr, internal,
+                           &internal_flags, idx, udata) < 0)
                         HGOTO_ERROR(H5E_BTREE, H5E_CANTSPLIT, FAIL, "unable to merge child node")
                 } /* end else */
             } /* end if */
             else if(idx == internal->nrec) { /* Right-most child */
                 if(retries > 0 && (internal->node_ptrs[idx - 1].node_nrec > merge_nrec)) {
-                    if(H5B2_redistribute2(hdr, dxpl_id, depth, internal, (idx - 1)) < 0)
+                    if(H5B2_redistribute2(hdr, dxpl_id, depth, internal, (idx - 1), udata) < 0)
                         HGOTO_ERROR(H5E_BTREE, H5E_CANTREDISTRIBUTE, FAIL, "unable to redistribute child node records")
                 } /* end if */
                 else {
                     if(H5B2_merge2(hdr, dxpl_id, depth, curr_node_ptr,
-                           parent_cache_info_flags_ptr, internal, &internal_flags, (idx - 1)) < 0)
+                           parent_cache_info_flags_ptr, internal,
+                           &internal_flags, (idx - 1), udata) < 0)
                         HGOTO_ERROR(H5E_BTREE, H5E_CANTSPLIT, FAIL, "unable to merge child node")
                 } /* end else */
             } /* end if */
             else { /* Middle child */
                 if(retries > 0 && ((internal->node_ptrs[idx + 1].node_nrec > merge_nrec) ||
                             (internal->node_ptrs[idx - 1].node_nrec > merge_nrec))) {
-                    if(H5B2_redistribute3(hdr, dxpl_id, depth, internal, &internal_flags, idx) < 0)
+                    if(H5B2_redistribute3(hdr, dxpl_id, depth, internal, &internal_flags, idx, udata) < 0)
                         HGOTO_ERROR(H5E_BTREE, H5E_CANTREDISTRIBUTE, FAIL, "unable to redistribute child node records")
                 } /* end if */
                 else {
                     if(H5B2_merge3(hdr, dxpl_id, depth, curr_node_ptr,
-                           parent_cache_info_flags_ptr, internal, &internal_flags, idx) < 0)
+                           parent_cache_info_flags_ptr, internal,
+                           &internal_flags, idx, udata) < 0)
                         HGOTO_ERROR(H5E_BTREE, H5E_CANTSPLIT, FAIL, "unable to merge child node")
                 } /* end else */
             } /* end else */
@@ -2294,12 +3311,14 @@ H5B2_remove_internal(H5B2_hdr_t *hdr, hid_t dxpl_id, hbool_t *depth_decreased,
         } /* end while */
 
         /* Handle deleting a record from an internal node */
-        if(!swap_loc && cmp == 0)
+        if(!swap_loc && cmp == 0) {
             swap_loc = H5B2_INT_NREC(internal, hdr, idx - 1);
+            swap_parent = internal;
+        }
 
         /* Swap record to delete with record from leaf, if we are the last internal node */
         if(swap_loc && depth == 1)
-            if(H5B2_swap_leaf(hdr, dxpl_id, depth, internal, &internal_flags, idx, swap_loc) < 0)
+            if(H5B2_swap_leaf(hdr, dxpl_id, depth, internal, &internal_flags, idx, swap_loc, swap_parent, udata) < 0)
                 HGOTO_ERROR(H5E_BTREE, H5E_CANTSWAP, FAIL, "Can't swap records in B-tree")
 
         /* Set pointers for advancing to child node */
@@ -2310,12 +3329,12 @@ H5B2_remove_internal(H5B2_hdr_t *hdr, hid_t dxpl_id, hbool_t *depth_decreased,
 
     /* Attempt to remove record from child node */
     if(depth > 1) {
-        if(H5B2_remove_internal(hdr, dxpl_id, depth_decreased, swap_loc, depth - 1,
+        if(H5B2_remove_internal(hdr, dxpl_id, depth_decreased, swap_loc, swap_parent, depth - 1,
                 new_cache_info, new_cache_info_flags_ptr, new_node_ptr, udata, op, op_data) < 0)
             HGOTO_ERROR(H5E_BTREE, H5E_CANTDELETE, FAIL, "unable to remove record from B-tree internal node")
     } /* end if */
     else {
-        if(H5B2_remove_leaf(hdr, dxpl_id, new_node_ptr, udata, op, op_data) < 0)
+        if(H5B2_remove_leaf(hdr, dxpl_id, new_node_ptr, new_cache_info, udata, op, op_data) < 0)
             HGOTO_ERROR(H5E_BTREE, H5E_CANTDELETE, FAIL, "unable to remove record from B-tree leaf node")
     } /* end else */
 
@@ -2324,7 +3343,8 @@ H5B2_remove_internal(H5B2_hdr_t *hdr, hid_t dxpl_id, hbool_t *depth_decreased,
         new_node_ptr->all_nrec--;
 
     /* Mark node as dirty */
-    internal_flags |= H5AC__DIRTIED_FLAG;
+    if(!(hdr->swmr_write && collapsed_root))
+        internal_flags |= H5AC__DIRTIED_FLAG;
 
 #ifdef H5B2_DEBUG
     H5B2_assert_internal((!collapsed_root ? (curr_node_ptr->all_nrec - 1) : new_node_ptr->all_nrec), hdr, internal);
@@ -2335,6 +3355,13 @@ done:
     if(internal && H5AC_unprotect(hdr->f, dxpl_id, H5AC_BT2_INT, internal_addr, internal, internal_flags) < 0)
         HDONE_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, FAIL, "unable to release internal B-tree node")
 
+    /* Release the new root's child on error */
+    if(new_root) {
+        HDassert(ret_value < 0);
+        if(H5AC_unprotect(hdr->f, dxpl_id, new_root_class, curr_node_ptr->addr, new_root, H5AC__NO_FLAGS_SET) < 0)
+            HDONE_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, FAIL, "unable to release B-tree node")
+    } /* end if */
+
     FUNC_LEAVE_NOAPI(ret_value)
 } /* H5B2_remove_internal() */
 
@@ -2355,8 +3382,8 @@ done:
  */
 herr_t
 H5B2_remove_leaf_by_idx(H5B2_hdr_t *hdr, hid_t dxpl_id,
-    H5B2_node_ptr_t *curr_node_ptr, unsigned idx, H5B2_remove_t op,
-    void *op_data)
+    H5B2_node_ptr_t *curr_node_ptr, void *parent, unsigned idx,
+    H5B2_remove_t op, void *op_data)
 {
     H5B2_leaf_t *leaf;                  /* Pointer to leaf node */
     haddr_t     leaf_addr = HADDR_UNDEF;  /* Leaf address on disk */
@@ -2372,7 +3399,7 @@ H5B2_remove_leaf_by_idx(H5B2_hdr_t *hdr, hid_t dxpl_id,
 
     /* Lock B-tree leaf node */
     leaf_addr = curr_node_ptr->addr;
-    if(NULL == (leaf = H5B2_protect_leaf(hdr, dxpl_id, leaf_addr, curr_node_ptr->node_nrec, H5AC_WRITE)))
+    if(NULL == (leaf = H5B2_protect_leaf(hdr, dxpl_id, leaf_addr, parent, curr_node_ptr->node_nrec, H5AC_WRITE)))
         HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree leaf node")
 
     /* Sanity check number of records */
@@ -2388,17 +3415,26 @@ H5B2_remove_leaf_by_idx(H5B2_hdr_t *hdr, hid_t dxpl_id,
     /* Update number of records in node */
     leaf->nrec--;
 
-    /* Mark leaf node as dirty also */
-    leaf_flags |= H5AC__DIRTIED_FLAG;
-
     if(leaf->nrec > 0) {
+        /* Shadow the node if doing SWMR writes */
+        if(hdr->swmr_write) {
+            if(H5B2_shadow_leaf(hdr, dxpl_id, curr_node_ptr, &leaf) < 0)
+                HGOTO_ERROR(H5E_BTREE, H5E_CANTCOPY, FAIL, "unable to shadow leaf node")
+            leaf_addr = curr_node_ptr->addr;
+        } /* end if */
+
         /* Pack record out of leaf */
         if(idx < leaf->nrec)
             HDmemmove(H5B2_LEAF_NREC(leaf, hdr, idx), H5B2_LEAF_NREC(leaf, hdr, (idx + 1)), hdr->cls->nrec_size * (leaf->nrec - idx));
+
+        /* Mark leaf node as dirty also */
+        leaf_flags |= H5AC__DIRTIED_FLAG;
     } /* end if */
     else {
         /* Let the cache know that the object is deleted */
-        leaf_flags |= H5AC__DELETED_FLAG | H5AC__FREE_FILE_SPACE_FLAG;
+        leaf_flags |= H5AC__DELETED_FLAG;
+        if(!hdr->swmr_write)
+            leaf_flags |= H5AC__DIRTIED_FLAG | H5AC__FREE_FILE_SPACE_FLAG;
 
         /* Reset address of parent node pointer */
         curr_node_ptr->addr = HADDR_UNDEF;
@@ -2432,14 +3468,16 @@ done:
  */
 herr_t
 H5B2_remove_internal_by_idx(H5B2_hdr_t *hdr, hid_t dxpl_id,
-    hbool_t *depth_decreased, void *swap_loc, unsigned depth,
+    hbool_t *depth_decreased, void *swap_loc, void *swap_parent, unsigned depth,
     H5AC_info_t *parent_cache_info, unsigned *parent_cache_info_flags_ptr,
-    H5B2_node_ptr_t *curr_node_ptr, hsize_t n, H5B2_remove_t op,
+    H5B2_node_ptr_t *curr_node_ptr, hsize_t n, void *udata, H5B2_remove_t op,
     void *op_data)
 {
     H5AC_info_t *new_cache_info;        /* Pointer to new cache info */
     unsigned *new_cache_info_flags_ptr = NULL;
     H5B2_node_ptr_t *new_node_ptr;      /* Pointer to new node pointer */
+    const H5AC_class_t *new_root_class; /* Pointer to new root node's class info */
+    void *new_root = NULL;              /* Pointer to new root node (if old root collapsed) */
     H5B2_internal_t *internal;          /* Pointer to internal node */
     unsigned internal_flags = H5AC__NO_FLAGS_SET;
     haddr_t internal_addr;              /* Address of internal node */
@@ -2458,7 +3496,7 @@ H5B2_remove_internal_by_idx(H5B2_hdr_t *hdr, hid_t dxpl_id,
 
     /* Lock current B-tree node */
     internal_addr = curr_node_ptr->addr;
-    if(NULL == (internal = H5B2_protect_internal(hdr, dxpl_id, internal_addr, curr_node_ptr->node_nrec, depth, H5AC_WRITE)))
+    if(NULL == (internal = H5B2_protect_internal(hdr, dxpl_id, internal_addr, parent_cache_info, curr_node_ptr->node_nrec, depth, H5AC_WRITE)))
         HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree internal node")
     HDassert(internal->nrec == curr_node_ptr->node_nrec);
     HDassert(depth == hdr->depth || internal->nrec > 1);
@@ -2474,16 +3512,71 @@ H5B2_remove_internal_by_idx(H5B2_hdr_t *hdr, hid_t dxpl_id,
 
         /* Merge children of root node */
         if(H5B2_merge2(hdr, dxpl_id, depth, curr_node_ptr,
-                parent_cache_info_flags_ptr, internal, &internal_flags, 0) < 0)
+                parent_cache_info_flags_ptr, internal, &internal_flags, 0,
+                udata) < 0)
             HGOTO_ERROR(H5E_BTREE, H5E_CANTSPLIT, FAIL, "unable to merge child node")
 
         /* Let the cache know that the object is deleted */
-        internal_flags |= H5AC__DELETED_FLAG | H5AC__FREE_FILE_SPACE_FLAG;
+        internal_flags |= H5AC__DELETED_FLAG;
+        if(!hdr->swmr_write)
+            internal_flags |= H5AC__FREE_FILE_SPACE_FLAG;
 
         /* Reset information in header's root node pointer */
         curr_node_ptr->addr = internal->node_ptrs[0].addr;
         curr_node_ptr->node_nrec = internal->node_ptrs[0].node_nrec;
 
+        /* Update flush dependencies */
+        if(hdr->swmr_write) {
+            hbool_t update_dep = FALSE; /* Whether to update root flush dependency */
+
+            /* Update hdr to root dependency */
+            if(depth > 1) {
+                H5B2_internal_t *new_root_int = NULL;
+
+                /* Protect new root */
+                if(NULL == (new_root_int = H5B2_protect_internal(hdr, dxpl_id, curr_node_ptr->addr, hdr, curr_node_ptr->node_nrec, (depth - 1), H5AC_WRITE)))
+                    HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree internal node")
+                new_root_class = H5AC_BT2_INT;
+                new_root = new_root_int;
+
+                if(new_root_int->parent == internal) {
+                    new_root_int->parent = hdr;
+                    update_dep = TRUE;
+                } /* end if */
+                else
+                    HDassert(new_root_int->parent == hdr);
+            } /* end if */
+            else {
+                H5B2_leaf_t *new_root_leaf = NULL;
+
+                /* Protect new root */
+                if(NULL == (new_root_leaf = H5B2_protect_leaf(hdr, dxpl_id, curr_node_ptr->addr, hdr, curr_node_ptr->node_nrec, H5AC_WRITE)))
+                    HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree leaf node")
+                new_root_class = H5AC_BT2_LEAF;
+                new_root = new_root_leaf;
+
+                if(new_root_leaf->parent == internal) {
+                    new_root_leaf->parent = hdr;
+                    update_dep = TRUE;
+                } /* end if */
+                else
+                    HDassert(new_root_leaf->parent == hdr);
+            } /* end else */
+
+            /* Update flush dependency if necessary */
+            if(update_dep) {
+                if(H5AC_destroy_flush_dependency(internal, new_root) < 0)
+                    HGOTO_ERROR(H5E_BTREE, H5E_CANTUNDEPEND, FAIL, "unable to destroy flush dependency")
+                if(H5AC_create_flush_dependency(hdr, new_root) < 0)
+                    HGOTO_ERROR(H5E_BTREE, H5E_CANTDEPEND, FAIL, "unable to create flush dependency")
+            } /* end if */
+
+            /* Unprotect the new root */
+            if(H5AC_unprotect(hdr->f, dxpl_id, new_root_class, curr_node_ptr->addr, new_root, H5AC__NO_FLAGS_SET) < 0)
+                HGOTO_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, FAIL, "unable to release B-tree node")
+            new_root = NULL;
+        } /* end if */
+
         /* Indicate that the level of the B-tree decreased */
         *depth_decreased = TRUE;
 
@@ -2502,6 +3595,13 @@ H5B2_remove_internal_by_idx(H5B2_hdr_t *hdr, hid_t dxpl_id,
         hbool_t found = FALSE;  /* Comparison value of records */
         unsigned retries;       /* Number of times to attempt redistribution */
 
+        /* Shadow the node if doing SWMR writes */
+        if(hdr->swmr_write && !collapsed_root) {
+            if(H5B2_shadow_internal(hdr, dxpl_id, depth, curr_node_ptr, &internal) < 0)
+                HGOTO_ERROR(H5E_BTREE, H5E_CANTCOPY, FAIL, "unable to shadow internal node")
+            internal_addr = curr_node_ptr->addr;
+        } /* end if */
+
         /* Locate node pointer for child */
         if(swap_loc)
             idx = 0;
@@ -2552,35 +3652,38 @@ H5B2_remove_internal_by_idx(H5B2_hdr_t *hdr, hid_t dxpl_id,
              */
             if(idx == 0) {    /* Left-most child */
                 if(retries > 0 && (internal->node_ptrs[idx + 1].node_nrec > merge_nrec)) {
-                    if(H5B2_redistribute2(hdr, dxpl_id, depth, internal, idx) < 0)
+                    if(H5B2_redistribute2(hdr, dxpl_id, depth, internal, idx, udata) < 0)
                         HGOTO_ERROR(H5E_BTREE, H5E_CANTREDISTRIBUTE, FAIL, "unable to redistribute child node records")
                 } /* end if */
                 else {
                     if(H5B2_merge2(hdr, dxpl_id, depth, curr_node_ptr,
-                           parent_cache_info_flags_ptr, internal, &internal_flags, idx) < 0)
+                           parent_cache_info_flags_ptr, internal,
+                           &internal_flags, idx, udata) < 0)
                         HGOTO_ERROR(H5E_BTREE, H5E_CANTSPLIT, FAIL, "unable to merge child node")
                 } /* end else */
             } /* end if */
             else if(idx == internal->nrec) { /* Right-most child */
                 if(retries > 0 && (internal->node_ptrs[idx - 1].node_nrec > merge_nrec)) {
-                    if(H5B2_redistribute2(hdr, dxpl_id, depth, internal, (idx - 1)) < 0)
+                    if(H5B2_redistribute2(hdr, dxpl_id, depth, internal, (idx - 1), udata) < 0)
                         HGOTO_ERROR(H5E_BTREE, H5E_CANTREDISTRIBUTE, FAIL, "unable to redistribute child node records")
                 } /* end if */
                 else {
                     if(H5B2_merge2(hdr, dxpl_id, depth, curr_node_ptr,
-                           parent_cache_info_flags_ptr, internal, &internal_flags, (idx - 1)) < 0)
+                           parent_cache_info_flags_ptr, internal,
+                           &internal_flags, (idx - 1), udata) < 0)
                         HGOTO_ERROR(H5E_BTREE, H5E_CANTSPLIT, FAIL, "unable to merge child node")
                 } /* end else */
             } /* end if */
             else { /* Middle child */
                 if(retries > 0 && ((internal->node_ptrs[idx + 1].node_nrec > merge_nrec) ||
                             (internal->node_ptrs[idx - 1].node_nrec > merge_nrec))) {
-                    if(H5B2_redistribute3(hdr, dxpl_id, depth, internal, &internal_flags, idx) < 0)
+                    if(H5B2_redistribute3(hdr, dxpl_id, depth, internal, &internal_flags, idx, udata) < 0)
                         HGOTO_ERROR(H5E_BTREE, H5E_CANTREDISTRIBUTE, FAIL, "unable to redistribute child node records")
                 } /* end if */
                 else {
                     if(H5B2_merge3(hdr, dxpl_id, depth, curr_node_ptr,
-                           parent_cache_info_flags_ptr, internal, &internal_flags, idx) < 0)
+                           parent_cache_info_flags_ptr, internal,
+                           &internal_flags, idx, udata) < 0)
                         HGOTO_ERROR(H5E_BTREE, H5E_CANTSPLIT, FAIL, "unable to merge child node")
                 } /* end else */
             } /* end else */
@@ -2629,12 +3732,14 @@ H5B2_remove_internal_by_idx(H5B2_hdr_t *hdr, hid_t dxpl_id,
         } /* end while */
 
         /* Handle deleting a record from an internal node */
-        if(!swap_loc && found)
+        if(!swap_loc && found) {
             swap_loc = H5B2_INT_NREC(internal, hdr, idx - 1);
+            swap_parent = internal;
+        }
 
         /* Swap record to delete with record from leaf, if we are the last internal node */
         if(swap_loc && depth == 1)
-            if(H5B2_swap_leaf(hdr, dxpl_id, depth, internal, &internal_flags, idx, swap_loc) < 0)
+            if(H5B2_swap_leaf(hdr, dxpl_id, depth, internal, &internal_flags, idx, swap_loc, swap_parent, udata) < 0)
                 HGOTO_ERROR(H5E_BTREE, H5E_CANTSWAP, FAIL, "can't swap records in B-tree")
 
         /* Set pointers for advancing to child node */
@@ -2645,12 +3750,12 @@ H5B2_remove_internal_by_idx(H5B2_hdr_t *hdr, hid_t dxpl_id,
 
     /* Attempt to remove record from child node */
     if(depth > 1) {
-        if(H5B2_remove_internal_by_idx(hdr, dxpl_id, depth_decreased, swap_loc, depth - 1,
-                new_cache_info, new_cache_info_flags_ptr, new_node_ptr, n, op, op_data) < 0)
+        if(H5B2_remove_internal_by_idx(hdr, dxpl_id, depth_decreased, swap_loc, swap_parent, depth - 1,
+                new_cache_info, new_cache_info_flags_ptr, new_node_ptr, n, udata, op, op_data) < 0)
             HGOTO_ERROR(H5E_BTREE, H5E_CANTDELETE, FAIL, "unable to remove record from B-tree internal node")
     } /* end if */
     else {
-        if(H5B2_remove_leaf_by_idx(hdr, dxpl_id, new_node_ptr, (unsigned)n, op, op_data) < 0)
+        if(H5B2_remove_leaf_by_idx(hdr, dxpl_id, new_node_ptr, new_cache_info, (unsigned)n, op, op_data) < 0)
             HGOTO_ERROR(H5E_BTREE, H5E_CANTDELETE, FAIL, "unable to remove record from B-tree leaf node")
     } /* end else */
 
@@ -2659,7 +3764,8 @@ H5B2_remove_internal_by_idx(H5B2_hdr_t *hdr, hid_t dxpl_id,
         new_node_ptr->all_nrec--;
 
     /* Mark node as dirty */
-    internal_flags |= H5AC__DIRTIED_FLAG;
+    if(!(hdr->swmr_write && collapsed_root))
+        internal_flags |= H5AC__DIRTIED_FLAG;
 
 #ifdef H5B2_DEBUG
     H5B2_assert_internal((!collapsed_root ? (curr_node_ptr->all_nrec - 1) : new_node_ptr->all_nrec), hdr, internal);
@@ -2670,6 +3776,13 @@ done:
     if(internal && H5AC_unprotect(hdr->f, dxpl_id, H5AC_BT2_INT, internal_addr, internal, internal_flags) < 0)
         HDONE_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, FAIL, "unable to release internal B-tree node")
 
+    /* Release the new root's child on error */
+    if(new_root) {
+        HDassert(ret_value < 0);
+        if(H5AC_unprotect(hdr->f, dxpl_id, new_root_class, curr_node_ptr->addr, new_root, H5AC__NO_FLAGS_SET) < 0)
+            HDONE_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, FAIL, "unable to release B-tree node")
+    } /* end if */
+
     FUNC_LEAVE_NOAPI(ret_value)
 } /* H5B2_remove_internal_by_idx() */
 
@@ -2702,7 +3815,7 @@ done:
  */
 herr_t
 H5B2_neighbor_leaf(H5B2_hdr_t *hdr, hid_t dxpl_id, H5B2_node_ptr_t *curr_node_ptr,
-    void *neighbor_loc, H5B2_compare_t comp, void *udata, H5B2_found_t op,
+    void *neighbor_loc, H5B2_compare_t comp, void *parent, void *udata, H5B2_found_t op,
     void *op_data)
 {
     H5B2_leaf_t *leaf;                  /* Pointer to leaf node */
@@ -2719,7 +3832,7 @@ H5B2_neighbor_leaf(H5B2_hdr_t *hdr, hid_t dxpl_id, H5B2_node_ptr_t *curr_node_pt
     HDassert(op);
 
     /* Lock current B-tree node */
-    if(NULL == (leaf = H5B2_protect_leaf(hdr, dxpl_id, curr_node_ptr->addr, curr_node_ptr->node_nrec, H5AC_READ)))
+    if(NULL == (leaf = H5B2_protect_leaf(hdr, dxpl_id, curr_node_ptr->addr, parent, curr_node_ptr->node_nrec, H5AC_READ)))
         HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree leaf node")
 
     /* Locate node pointer for child */
@@ -2789,7 +3902,7 @@ done:
 herr_t
 H5B2_neighbor_internal(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth,
     H5B2_node_ptr_t *curr_node_ptr, void *neighbor_loc, H5B2_compare_t comp,
-    void *udata, H5B2_found_t op, void *op_data)
+    void *parent, void *udata, H5B2_found_t op, void *op_data)
 {
     H5B2_internal_t *internal;          /* Pointer to internal node */
     unsigned    idx;                    /* Location of record which matches key */
@@ -2806,7 +3919,7 @@ H5B2_neighbor_internal(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth,
     HDassert(op);
 
     /* Lock current B-tree node */
-    if(NULL == (internal = H5B2_protect_internal(hdr, dxpl_id, curr_node_ptr->addr, curr_node_ptr->node_nrec, depth, H5AC_READ)))
+    if(NULL == (internal = H5B2_protect_internal(hdr, dxpl_id, curr_node_ptr->addr, parent, curr_node_ptr->node_nrec, depth, H5AC_READ)))
         HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree internal node")
 
     /* Locate node pointer for child */
@@ -2828,11 +3941,11 @@ H5B2_neighbor_internal(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth,
 
     /* Attempt to find neighboring record */
     if(depth > 1) {
-        if(H5B2_neighbor_internal(hdr, dxpl_id, depth - 1, &internal->node_ptrs[idx], neighbor_loc, comp, udata, op, op_data) < 0)
+        if(H5B2_neighbor_internal(hdr, dxpl_id, depth - 1, &internal->node_ptrs[idx], neighbor_loc, comp, internal, udata, op, op_data) < 0)
             HGOTO_ERROR(H5E_BTREE, H5E_NOTFOUND, FAIL, "unable to find neighbor record in B-tree internal node")
     } /* end if */
     else {
-        if(H5B2_neighbor_leaf(hdr, dxpl_id, &internal->node_ptrs[idx], neighbor_loc, comp, udata, op, op_data) < 0)
+        if(H5B2_neighbor_leaf(hdr, dxpl_id, &internal->node_ptrs[idx], neighbor_loc, comp, internal, udata, op, op_data) < 0)
             HGOTO_ERROR(H5E_BTREE, H5E_NOTFOUND, FAIL, "unable to find neighbor record in B-tree leaf node")
     } /* end else */
 
@@ -2861,7 +3974,8 @@ done:
  */
 herr_t
 H5B2_delete_node(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth,
-    const H5B2_node_ptr_t *curr_node, H5B2_remove_t op, void *op_data)
+    const H5B2_node_ptr_t *curr_node, void *parent, H5B2_remove_t op,
+    void *op_data)
 {
     const H5AC_class_t *curr_node_class = NULL; /* Pointer to current node's class info */
     void *node = NULL;                  /* Pointers to current node */
@@ -2879,7 +3993,7 @@ H5B2_delete_node(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth,
         unsigned u;                    /* Local index */
 
         /* Lock the current B-tree node */
-        if(NULL == (internal = H5B2_protect_internal(hdr, dxpl_id, curr_node->addr, curr_node->node_nrec, depth, H5AC_WRITE)))
+        if(NULL == (internal = H5B2_protect_internal(hdr, dxpl_id, curr_node->addr, parent, curr_node->node_nrec, depth, H5AC_WRITE)))
             HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree internal node")
 
         /* Set up information about current node */
@@ -2889,14 +4003,14 @@ H5B2_delete_node(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth,
 
         /* Descend into children */
         for(u = 0; u < internal->nrec + (unsigned)1; u++)
-            if(H5B2_delete_node(hdr, dxpl_id, (depth - 1), &(internal->node_ptrs[u]), op, op_data) < 0)
+            if(H5B2_delete_node(hdr, dxpl_id, (depth - 1), &(internal->node_ptrs[u]), internal, op, op_data) < 0)
                 HGOTO_ERROR(H5E_BTREE, H5E_CANTLIST, FAIL, "node descent failed")
     } /* end if */
     else {
         H5B2_leaf_t *leaf;             /* Pointer to leaf node */
 
         /* Lock the current B-tree node */
-        if(NULL == (leaf = H5B2_protect_leaf(hdr, dxpl_id, curr_node->addr, curr_node->node_nrec, H5AC_WRITE)))
+        if(NULL == (leaf = H5B2_protect_leaf(hdr, dxpl_id, curr_node->addr, parent, curr_node->node_nrec, H5AC_WRITE)))
             HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree leaf node")
 
         /* Set up information about current node */
@@ -2919,7 +4033,7 @@ H5B2_delete_node(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth,
 
 done:
     /* Unlock & delete current node */
-    if(node && H5AC_unprotect(hdr->f, dxpl_id, curr_node_class, curr_node->addr, node, H5AC__DELETED_FLAG | H5AC__FREE_FILE_SPACE_FLAG) < 0)
+    if(node && H5AC_unprotect(hdr->f, dxpl_id, curr_node_class, curr_node->addr, node, H5AC__DELETED_FLAG | (hdr->swmr_write ? 0 : H5AC__FREE_FILE_SPACE_FLAG)) < 0)
         HDONE_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, FAIL, "unable to release B-tree node")
 
     FUNC_LEAVE_NOAPI(ret_value)
@@ -2941,7 +4055,7 @@ done:
  */
 herr_t
 H5B2_node_size(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth,
-    const H5B2_node_ptr_t *curr_node, hsize_t *btree_size)
+    const H5B2_node_ptr_t *curr_node, void *parent, hsize_t *btree_size)
 {
     H5B2_internal_t 	*internal = NULL;     	/* Pointer to internal node */
     herr_t 		ret_value = SUCCEED;  	/* Iterator return value */
@@ -2955,7 +4069,7 @@ H5B2_node_size(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth,
     HDassert(depth > 0);
 
     /* Lock the current B-tree node */
-    if(NULL == (internal = H5B2_protect_internal(hdr, dxpl_id, curr_node->addr, curr_node->node_nrec, depth, H5AC_READ)))
+    if(NULL == (internal = H5B2_protect_internal(hdr, dxpl_id, curr_node->addr, parent, curr_node->node_nrec, depth, H5AC_READ)))
         HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree internal node")
 
     /* Recursively descend into child nodes, if we are above the "twig" level in the B-tree */
@@ -2964,7 +4078,7 @@ H5B2_node_size(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth,
 
         /* Descend into children */
         for(u = 0; u < internal->nrec + (unsigned)1; u++)
-            if(H5B2_node_size(hdr, dxpl_id, (depth - 1), &(internal->node_ptrs[u]), btree_size) < 0)
+            if(H5B2_node_size(hdr, dxpl_id, (depth - 1), &(internal->node_ptrs[u]), internal, btree_size) < 0)
                 HGOTO_ERROR(H5E_BTREE, H5E_CANTLIST, FAIL, "node iteration failed")
     } /* end if */
     else /* depth is 1: count all the leaf nodes from this node */
@@ -3066,6 +4180,193 @@ done:
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5B2_leaf_free() */
 
+
+/*-------------------------------------------------------------------------
+ * Function:    H5B2_shadow_internal
+ *
+ * Purpose:     fnord
+ *
+ * Return:      Non-negative on success/Negative on failure
+ *
+ * Programmer:  Neil Fortner
+ *              Apr 27 2012
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5B2_shadow_internal(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth,
+    H5B2_node_ptr_t *curr_node_ptr, H5B2_internal_t **internal)
+{
+    hbool_t node_pinned = FALSE;
+    hbool_t node_protected = TRUE;
+    haddr_t new_node_addr;              /* Address to move node to */
+    herr_t ret_value = SUCCEED;         /* Return value */
+
+    FUNC_ENTER_NOAPI_NOINIT
+
+    /*
+     * Check arguments.
+     */
+    HDassert(hdr);
+    HDassert(depth > 0);
+    HDassert(curr_node_ptr);
+    HDassert(H5F_addr_defined(curr_node_ptr->addr));
+    HDassert(internal);
+    HDassert(*internal);
+    HDassert(hdr->swmr_write);
+
+    /* We only need to shadow the node if it has not been shadowed since the
+     * last time the header was flushed, as otherwise it will be unreachable by
+     * the readers so there will be no need to shadow.  To check if it has been
+     * shadowed, check if it is on the shadowed node list.  shadowed_next will
+     * be equal to internal if this node is at the head, so it can be used to
+     * determine if this node is in the list. */
+    if(!(*internal)->shadowed_next) {
+        /*
+         * We must clone the old node so readers with an out-of-date version of
+         * the parent can still see the correct number of children, via the
+         * shadowed node.  Remove it from cache but do not mark it free on disk.
+         */
+        /* Allocate space for the cloned node */
+        if(HADDR_UNDEF == (new_node_addr = H5MF_alloc(hdr->f, H5FD_MEM_BTREE, dxpl_id, (hsize_t)hdr->node_size)))
+            HGOTO_ERROR(H5E_BTREE, H5E_CANTALLOC, FAIL, "unable to allocate file space to move B-tree node")
+
+        /* Pin old entry so it is not flushed when we unprotect */
+        if(H5AC_pin_protected_entry(*internal) < 0)
+            HGOTO_ERROR(H5E_BTREE, H5E_CANTPIN, FAIL, "unable to pin old B-tree node")
+        node_pinned = TRUE;
+
+        /* Unprotect node so we can move it.  Do not mark it dirty yet so it is
+         * not flushed to the old location (however unlikely). */
+        if(H5AC_unprotect(hdr->f, dxpl_id, H5AC_BT2_INT, curr_node_ptr->addr, *internal, H5AC__NO_FLAGS_SET) < 0)
+            HGOTO_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, FAIL, "unable to release old B-tree node")
+        node_protected = FALSE;
+
+        /* Move the location of the old child on the disk */
+        if(H5AC_move_entry(hdr->f, H5AC_BT2_INT, curr_node_ptr->addr, new_node_addr) < 0)
+            HGOTO_ERROR(H5E_BTREE, H5E_CANTMOVE, FAIL, "unable to move B-tree node")
+        curr_node_ptr->addr = new_node_addr;
+
+        /* Re-protect node at new address.  Should have the same location in
+         * memory. */
+        if(*internal != H5B2_protect_internal(hdr, dxpl_id, curr_node_ptr->addr, (*internal)->parent, curr_node_ptr->node_nrec, depth, H5AC_WRITE))
+            HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree internal node")
+        node_protected = TRUE;
+
+        /* Add node to shadowed node list */
+        if(hdr->shadowed_internal)
+            (*internal)->shadowed_next = hdr->shadowed_internal;
+        else
+            (*internal)->shadowed_next = *internal;
+        hdr->shadowed_internal = *internal;
+    } /* end if */
+
+done:
+    if(node_pinned)
+        if(H5AC_unpin_entry(*internal) < 0)
+            HDONE_ERROR(H5E_BTREE, H5E_CANTUNPIN, FAIL, "unable to unpin internal B-tree node")
+
+    if(!node_protected) {
+        HDassert(ret_value < 0);
+        *internal = NULL;
+    } /* end if */
+
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5B2_shadow_internal() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5B2_shadow_leaf
+ *
+ * Purpose:     fnord
+ *
+ * Return:      Non-negative on success/Negative on failure
+ *
+ * Programmer:  Neil Fortner
+ *              Apr 27 2012
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5B2_shadow_leaf(H5B2_hdr_t *hdr, hid_t dxpl_id,
+    H5B2_node_ptr_t *curr_node_ptr, H5B2_leaf_t **leaf)
+{
+    hbool_t node_pinned = FALSE;
+    hbool_t node_protected = TRUE;
+    haddr_t new_node_addr;              /* Address to move node to */
+    herr_t ret_value = SUCCEED;         /* Return value */
+
+    FUNC_ENTER_NOAPI_NOINIT
+
+    /*
+     * Check arguments.
+     */
+    HDassert(hdr);
+    HDassert(curr_node_ptr);
+    HDassert(H5F_addr_defined(curr_node_ptr->addr));
+    HDassert(leaf);
+    HDassert(*leaf);
+    HDassert(hdr->swmr_write);
+
+    /* We only need to shadow the node if it has not been shadowed since the
+     * last time the header was flushed, as otherwise it will be unreachable by
+     * the readers so there will be no need to shadow.  To check if it has been
+     * shadowed, check if it is on the shadowed node list.  shadowed_next will
+     * be equal to leaf if this node is at the head, so it can be used to
+     * determine if this node is in the list. */
+    if(!(*leaf)->shadowed_next) {
+        /*
+        * We must clone the old node so readers with an out-of-date version of
+        * the parent can still see the correct number of children, via the
+        * shadowed node.  Remove it from cache but do not mark it free on disk.
+        */
+        /* Allocate space for the cloned node */
+        if(HADDR_UNDEF == (new_node_addr = H5MF_alloc(hdr->f, H5FD_MEM_BTREE, dxpl_id, (hsize_t)hdr->node_size)))
+            HGOTO_ERROR(H5E_BTREE, H5E_CANTALLOC, FAIL, "unable to allocate file space to move B-tree node")
+
+        /* Pin old entry so it is not flushed when we unprotect */
+        if(H5AC_pin_protected_entry(*leaf) < 0)
+            HGOTO_ERROR(H5E_BTREE, H5E_CANTPIN, FAIL, "unable to pin old B-tree node")
+        node_pinned = TRUE;
+
+        /* Unprotect node so we can move it.  Do not mark it dirty yet so it is
+        * not flushed to the old location (however unlikely). */
+        if(H5AC_unprotect(hdr->f, dxpl_id, H5AC_BT2_LEAF, curr_node_ptr->addr, *leaf, H5AC__NO_FLAGS_SET) < 0)
+            HGOTO_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, FAIL, "unable to release old B-tree node")
+        node_protected = FALSE;
+
+        /* Move the location of the old child on the disk */
+        if(H5AC_move_entry(hdr->f, H5AC_BT2_LEAF, curr_node_ptr->addr, new_node_addr) < 0)
+            HGOTO_ERROR(H5E_BTREE, H5E_CANTMOVE, FAIL, "unable to move B-tree node")
+        curr_node_ptr->addr = new_node_addr;
+
+        /* Re-protect node at new address.  Should have the same location in
+         * memory. */
+        if(*leaf != H5B2_protect_leaf(hdr, dxpl_id, curr_node_ptr->addr, (*leaf)->parent, curr_node_ptr->node_nrec, H5AC_WRITE))
+            HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree leaf node")
+        node_protected = TRUE;
+
+        /* Add node to shadowed node list */
+        if(hdr->shadowed_leaf)
+            (*leaf)->shadowed_next = hdr->shadowed_leaf;
+        else
+            (*leaf)->shadowed_next = *leaf;
+        hdr->shadowed_leaf = *leaf;
+    } /* end if */
+
+done:
+    if(node_pinned)
+        if(H5AC_unpin_entry(*leaf) < 0)
+            HDONE_ERROR(H5E_BTREE, H5E_CANTUNPIN, FAIL, "unable to unpin leaf B-tree node")
+
+    if(!node_protected) {
+        HDassert(ret_value < 0);
+        *leaf = NULL;
+    } /* end if */
+
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5B2_shadow_leaf() */
+
 #ifdef H5B2_DEBUG
 
 /*-------------------------------------------------------------------------
diff --git a/src/H5B2pkg.h b/src/H5B2pkg.h
index b820853..96ef54f 100644
--- a/src/H5B2pkg.h
+++ b/src/H5B2pkg.h
@@ -160,6 +160,7 @@ typedef struct H5B2_hdr_t {
 
     /* Shared internal data structures (not stored) */
     H5F_t       *f;             /* Pointer to the file that the B-tree is in */
+    void        *parent;        /* Flush dependency parent */
     haddr_t     addr;           /* Address of B-tree header in the file */
     size_t      hdr_size;       /* Size of the B-tree header on disk */
     size_t      rc;             /* Reference count of nodes using this header */
@@ -172,6 +173,9 @@ typedef struct H5B2_hdr_t {
     uint8_t	*page;	        /* Common disk page for I/O */
     size_t      *nat_off;       /* Array of offsets of native records */
     H5B2_node_info_t *node_info; /* Table of node info structs for current depth of B-tree */
+    hbool_t     swmr_write;     /* Whether we are doing SWMR writes */
+    struct H5B2_leaf_t *shadowed_leaf; /* Linked list of shadowed leaf nodes */
+    struct H5B2_internal_t *shadowed_internal; /* Linked list of shadowed internal nodes */
 
     /* Client information (not stored) */
     const H5B2_class_t *cls;	/* Class of B-tree client */
@@ -185,8 +189,10 @@ typedef struct H5B2_leaf_t {
 
     /* Internal B-tree information */
     H5B2_hdr_t	*hdr;		/* Pointer to the [pinned] v2 B-tree header   */
+    void        *parent;        /* Flush dependency parent                    */
     uint8_t     *leaf_native;   /* Pointer to native records                  */
     uint16_t    nrec;           /* Number of records in node                  */
+    struct H5B2_leaf_t *shadowed_next; /* Next node in shadowed list          */
 } H5B2_leaf_t;
 
 /* B-tree internal node information */
@@ -196,10 +202,12 @@ typedef struct H5B2_internal_t {
 
     /* Internal B-tree information */
     H5B2_hdr_t	*hdr;		/* Pointer to the [pinned] v2 B-tree header   */
+    void        *parent;        /* Flush dependency parent                    */
     uint8_t     *int_native;    /* Pointer to native records                  */
     H5B2_node_ptr_t *node_ptrs; /* Pointer to node pointers                   */
     uint16_t    nrec;           /* Number of records in node                  */
     uint16_t    depth;          /* Depth of this node in the B-tree           */
+    struct H5B2_internal_t *shadowed_next; /* Next node in shadowed list      */
 } H5B2_internal_t;
 
 /* v2 B-tree */
@@ -211,6 +219,7 @@ struct H5B2_t {
 /* Callback info for loading a free space header into the cache */
 typedef struct H5B2_hdr_cache_ud_t {
     H5F_t *f;                   /* File that v2 b-tree header is within */
+    void *parent;               /* Flush dependency parent */
     void *ctx_udata;            /* User-data for protecting */
 } H5B2_hdr_cache_ud_t;
 
@@ -218,6 +227,7 @@ typedef struct H5B2_hdr_cache_ud_t {
 typedef struct H5B2_internal_cache_ud_t {
     H5F_t *f;                   /* File that v2 b-tree header is within */
     H5B2_hdr_t *hdr;            /* v2 B-tree header */
+    void *parent;               /* Flush dependency parent */
     unsigned nrec;              /* Number of records in node to load */
     unsigned depth;             /* Depth of node to load */
 } H5B2_internal_cache_ud_t;
@@ -226,6 +236,7 @@ typedef struct H5B2_internal_cache_ud_t {
 typedef struct H5B2_leaf_cache_ud_t {
     H5F_t *f;                   /* File that v2 b-tree header is within */
     H5B2_hdr_t *hdr;            /* v2 B-tree header */
+    void *parent;               /* Flush dependency parent */
     unsigned nrec;              /* Number of records in node to load */
 } H5B2_leaf_cache_ud_t;
 
@@ -273,9 +284,9 @@ extern const H5B2_class_t *const H5B2_client_class_g[H5B2_NUM_BTREE_ID];
 /* Routines for managing B-tree header info */
 H5_DLL H5B2_hdr_t *H5B2_hdr_alloc(H5F_t *f);
 H5_DLL haddr_t H5B2_hdr_create(H5F_t *f, hid_t dxpl_id,
-    const H5B2_create_t *cparam, void *ctx_udata);
+    const H5B2_create_t *cparam, void *ctx_udata, void *parent);
 H5_DLL herr_t H5B2_hdr_init(H5B2_hdr_t *hdr, const H5B2_create_t *cparam,
-    void *ctx_udata, uint16_t depth);
+    void *ctx_udata, void *parent, uint16_t depth);
 H5_DLL herr_t H5B2_hdr_incr(H5B2_hdr_t *hdr);
 H5_DLL herr_t H5B2_hdr_decr(H5B2_hdr_t *hdr);
 H5_DLL herr_t H5B2_hdr_fuse_incr(H5B2_hdr_t *hdr);
@@ -285,15 +296,15 @@ H5_DLL herr_t H5B2_hdr_delete(H5B2_hdr_t *hdr, hid_t dxpl_id);
 
 /* Routines for operating on leaf nodes */
 H5B2_leaf_t *H5B2_protect_leaf(H5B2_hdr_t *hdr, hid_t dxpl_id, haddr_t addr,
-    unsigned nrec, H5AC_protect_t rw);
+    void *parent, unsigned nrec, H5AC_protect_t rw);
 
 /* Routines for operating on internal nodes */
 H5_DLL H5B2_internal_t *H5B2_protect_internal(H5B2_hdr_t *hdr, hid_t dxpl_id,
-    haddr_t addr, unsigned nrec, unsigned depth, H5AC_protect_t rw);
+    haddr_t addr, void *parent, unsigned nrec, unsigned depth, H5AC_protect_t rw);
 
 /* Routines for allocating nodes */
-H5_DLL herr_t H5B2_split_root(H5B2_hdr_t *hdr, hid_t dxpl_id);
-H5_DLL herr_t H5B2_create_leaf(H5B2_hdr_t *hdr, hid_t dxpl_id,
+H5_DLL herr_t H5B2_split_root(H5B2_hdr_t *hdr, hid_t dxpl_id, void *udata);
+H5_DLL herr_t H5B2_create_leaf(H5B2_hdr_t *hdr, hid_t dxpl_id, void *parent,
     H5B2_node_ptr_t *node_ptr);
 
 /* Routines for releasing structures */
@@ -304,45 +315,50 @@ H5_DLL herr_t H5B2_internal_free(H5B2_internal_t *i);
 /* Routines for inserting records */
 H5_DLL herr_t H5B2_insert_internal(H5B2_hdr_t *hdr, hid_t dxpl_id,
     unsigned depth, unsigned *parent_cache_info_flags_ptr,
-    H5B2_node_ptr_t *curr_node_ptr, void *udata);
+    H5B2_node_ptr_t *curr_node_ptr, void *parent, void *udata);
 H5_DLL herr_t H5B2_insert_leaf(H5B2_hdr_t *hdr, hid_t dxpl_id,
-    H5B2_node_ptr_t *curr_node_ptr, void *udata);
+    H5B2_node_ptr_t *curr_node_ptr, void *parent, void *udata);
 
 /* Routines for iterating over nodes/records */
 H5_DLL herr_t H5B2_iterate_node(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth,
-    const H5B2_node_ptr_t *curr_node, H5B2_operator_t op, void *op_data);
+    const H5B2_node_ptr_t *curr_node, void *parent, H5B2_operator_t op, void *op_data);
 H5_DLL herr_t H5B2_node_size(H5B2_hdr_t *hdr, hid_t dxpl_id,
-    unsigned depth, const H5B2_node_ptr_t *curr_node, hsize_t *op_data);
+    unsigned depth, const H5B2_node_ptr_t *curr_node, void *parent,
+    hsize_t *op_data);
 
 /* Routines for locating records */
 H5_DLL int H5B2_locate_record(const H5B2_class_t *type, unsigned nrec,
     size_t *rec_off, const uint8_t *native, const void *udata, unsigned *idx);
 H5_DLL herr_t H5B2_neighbor_internal(H5B2_hdr_t *hdr, hid_t dxpl_id,
     unsigned depth, H5B2_node_ptr_t *curr_node_ptr, void *neighbor_loc,
-    H5B2_compare_t comp, void *udata, H5B2_found_t op, void *op_data);
+    H5B2_compare_t comp, void *parent, void *udata, H5B2_found_t op,
+    void *op_data);
 H5_DLL herr_t H5B2_neighbor_leaf(H5B2_hdr_t *hdr, hid_t dxpl_id,
-    H5B2_node_ptr_t *curr_node_ptr, void *neighbor_loc,
-    H5B2_compare_t comp, void *udata, H5B2_found_t op, void *op_data);
+    H5B2_node_ptr_t *curr_node_ptr, void *neighbor_loc, H5B2_compare_t comp,
+    void *parent, void *udata, H5B2_found_t op, void *op_data);
 
 /* Routines for removing records */
 H5_DLL herr_t H5B2_remove_internal(H5B2_hdr_t *hdr, hid_t dxpl_id,
-    hbool_t *depth_decreased, void *swap_loc, unsigned depth, H5AC_info_t *parent_cache_info,
-    hbool_t * parent_cache_info_dirtied_ptr, H5B2_node_ptr_t *curr_node_ptr, void *udata,
-    H5B2_remove_t op, void *op_data);
-H5_DLL herr_t H5B2_remove_leaf(H5B2_hdr_t *hdr, hid_t dxpl_id,
+    hbool_t *depth_decreased, void *swap_loc, void *swap_parent, unsigned depth,
+    H5AC_info_t *parent_cache_info, hbool_t * parent_cache_info_dirtied_ptr,
     H5B2_node_ptr_t *curr_node_ptr, void *udata, H5B2_remove_t op,
     void *op_data);
+H5_DLL herr_t H5B2_remove_leaf(H5B2_hdr_t *hdr, hid_t dxpl_id,
+    H5B2_node_ptr_t *curr_node_ptr, void *parent, void *udata, H5B2_remove_t op,
+    void *op_data);
 H5_DLL herr_t H5B2_remove_internal_by_idx(H5B2_hdr_t *hdr, hid_t dxpl_id,
-    hbool_t *depth_decreased, void *swap_loc, unsigned depth, H5AC_info_t *parent_cache_info,
-    hbool_t * parent_cache_info_dirtied_ptr, H5B2_node_ptr_t *curr_node_ptr, hsize_t idx,
-    H5B2_remove_t op, void *op_data);
-H5_DLL herr_t H5B2_remove_leaf_by_idx(H5B2_hdr_t *hdr, hid_t dxpl_id,
-    H5B2_node_ptr_t *curr_node_ptr, unsigned idx, H5B2_remove_t op,
+    hbool_t *depth_decreased, void *swap_loc, void *swap_parent, unsigned depth,
+    H5AC_info_t *parent_cache_info, hbool_t * parent_cache_info_dirtied_ptr,
+    H5B2_node_ptr_t *curr_node_ptr, hsize_t idx, void *udata, H5B2_remove_t op,
     void *op_data);
+H5_DLL herr_t H5B2_remove_leaf_by_idx(H5B2_hdr_t *hdr, hid_t dxpl_id,
+    H5B2_node_ptr_t *curr_node_ptr, void *parent, unsigned idx,
+    H5B2_remove_t op, void *op_data);
 
 /* Routines for deleting nodes */
 H5_DLL herr_t H5B2_delete_node(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth,
-    const H5B2_node_ptr_t *curr_node, H5B2_remove_t op, void *op_data);
+    const H5B2_node_ptr_t *curr_node, void *parent, H5B2_remove_t op,
+    void *op_data);
 
 /* Debugging routines for dumping file structures */
 H5_DLL herr_t H5B2_hdr_debug(H5F_t *f, hid_t dxpl_id, haddr_t addr,
diff --git a/src/H5B2private.h b/src/H5B2private.h
index 8ec9954..7ec0019 100644
--- a/src/H5B2private.h
+++ b/src/H5B2private.h
@@ -94,6 +94,8 @@ struct H5B2_class_t {
     herr_t (*compare)(const void *rec1, const void *rec2); 		/* Compare two native records */
     herr_t (*encode)(uint8_t *raw, const void *record, void *ctx);  	/* Encode record from native form to disk storage form */
     herr_t (*decode)(const uint8_t *raw, void *record, void *ctx);  	/* Decode record from disk storage form to native form */
+    herr_t (*crt_flush_dep)(void *record, void *udata, void *parent);   /* Create a flush dependency with record as child */
+    herr_t (*upd_flush_dep)(void *record, void *udata, void *old_parent, void *new_parent); /* Update a flush dependency with record as child */
     herr_t (*debug)(FILE *stream, const H5F_t *f, hid_t dxpl_id,    	/* Print a record for debugging */
         int indent, int fwidth, const void *record, const void *ctx);
     void *(*crt_dbg_ctx)(H5F_t *f, hid_t dxpl_id, haddr_t obj_addr); 	/* Create debugging context */
@@ -128,8 +130,9 @@ typedef struct H5B2_t H5B2_t;
 /* Library-private Function Prototypes */
 /***************************************/
 H5_DLL H5B2_t *H5B2_create(H5F_t *f, hid_t dxpl_id, const H5B2_create_t *cparam,
-    void *ctx_udata);
-H5_DLL H5B2_t *H5B2_open(H5F_t *f, hid_t dxpl_id, haddr_t addr, void *ctx_udata);
+    void *ctx_udata, void *parent);
+H5_DLL H5B2_t *H5B2_open(H5F_t *f, hid_t dxpl_id, haddr_t addr, void *ctx_udata,
+    void *parent);
 H5_DLL herr_t H5B2_get_addr(const H5B2_t *bt2, haddr_t *addr/*out*/);
 H5_DLL herr_t H5B2_insert(H5B2_t *bt2, hid_t dxpl_id, void *udata);
 H5_DLL herr_t H5B2_iterate(H5B2_t *bt2, hid_t dxpl_id, H5B2_operator_t op,
@@ -145,13 +148,18 @@ H5_DLL herr_t H5B2_modify(H5B2_t *bt2, hid_t dxpl_id, void *udata,
 H5_DLL herr_t H5B2_remove(H5B2_t *b2, hid_t dxpl_id, void *udata,
     H5B2_remove_t op, void *op_data);
 H5_DLL herr_t H5B2_remove_by_idx(H5B2_t *bt2, hid_t dxpl_id,
-    H5_iter_order_t order, hsize_t idx, H5B2_remove_t op, void *op_data);
+    H5_iter_order_t order, hsize_t idx, void *udata, H5B2_remove_t op,
+    void *op_data);
 H5_DLL herr_t H5B2_get_nrec(const H5B2_t *bt2, hsize_t *nrec);
 H5_DLL herr_t H5B2_size(H5B2_t *bt2, hid_t dxpl_id,
     hsize_t *btree_size);
 H5_DLL herr_t H5B2_close(H5B2_t *bt2, hid_t dxpl_id);
 H5_DLL herr_t H5B2_delete(H5F_t *f, hid_t dxpl_id, haddr_t addr,
-    void *ctx_udata, H5B2_remove_t op, void *op_data);
+    void *ctx_udata, void *parent, H5B2_remove_t op, void *op_data);
+H5_DLL htri_t H5B2_support(H5B2_t *bt2, hid_t dxpl_id, void *udata,
+    void *child);
+H5_DLL herr_t H5B2_unsupport(H5B2_t *bt2, hid_t dxpl_id, void *udata,
+    void *child);
 
 /* Statistics routines */
 H5_DLL herr_t H5B2_stat_info(H5B2_t *bt2, H5B2_stat_t *info);
diff --git a/src/H5B2stat.c b/src/H5B2stat.c
index a8f1fbd..05e81ed 100644
--- a/src/H5B2stat.c
+++ b/src/H5B2stat.c
@@ -140,7 +140,7 @@ H5B2_size(H5B2_t *bt2, hid_t dxpl_id, hsize_t *btree_size)
             *btree_size += hdr->node_size;
         else
             /* Iterate through nodes */
-            if(H5B2_node_size(hdr, dxpl_id, hdr->depth, &hdr->root, btree_size) < 0)
+            if(H5B2_node_size(hdr, dxpl_id, hdr->depth, &hdr->root, hdr, btree_size) < 0)
                 HGOTO_ERROR(H5E_BTREE, H5E_CANTLIST, FAIL, "node iteration failed")
     } /* end if */
 
diff --git a/src/H5B2test.c b/src/H5B2test.c
index 8507d6e..06736e7 100644
--- a/src/H5B2test.c
+++ b/src/H5B2test.c
@@ -86,6 +86,8 @@ const H5B2_class_t H5B2_TEST[1]={{   /* B-tree class information */
     H5B2_test_compare,          /* Record comparison callback */
     H5B2_test_encode,           /* Record encoding callback */
     H5B2_test_decode,           /* Record decoding callback */
+    NULL,                       /* Create flush dependency */
+    NULL,                       /* Update flush dependency */
     H5B2_test_debug,            /* Record debugging callback */
     H5B2_test_crt_dbg_context,  /* Create debugging context */
     H5B2_test_dst_context       /* Destroy debugging context */
@@ -397,6 +399,7 @@ H5B2_get_node_info_test(H5B2_t *bt2, hid_t dxpl_id, void *udata,
 {
     H5B2_hdr_t	*hdr;                   /* Pointer to the B-tree header */
     H5B2_node_ptr_t curr_node_ptr;      /* Node pointer info for current node */
+    void        *parent = NULL;         /* Parent of current node */
     unsigned    depth;                  /* Current depth of the tree */
     int         cmp;                    /* Comparison value of records */
     unsigned    idx;                    /* Location of record which matches key */
@@ -416,6 +419,10 @@ H5B2_get_node_info_test(H5B2_t *bt2, hid_t dxpl_id, void *udata,
     /* Make copy of the root node pointer to start search with */
     curr_node_ptr = hdr->root;
 
+        /* Set initial parent, if doing swmr writes */
+    if(hdr->swmr_write)
+        parent = hdr;
+
     /* Current depth of the tree */
     depth = hdr->depth;
 
@@ -430,9 +437,16 @@ H5B2_get_node_info_test(H5B2_t *bt2, hid_t dxpl_id, void *udata,
         H5B2_node_ptr_t next_node_ptr;      /* Node pointer info for next node */
 
         /* Lock B-tree current node */
-        if(NULL == (internal = H5B2_protect_internal(hdr, dxpl_id, curr_node_ptr.addr, curr_node_ptr.node_nrec, depth, H5AC_READ)))
+        if(NULL == (internal = H5B2_protect_internal(hdr, dxpl_id, curr_node_ptr.addr, parent, curr_node_ptr.node_nrec, depth, H5AC_READ)))
             HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to load B-tree internal node")
 
+        /* Unpin parent if necessary */
+        if(parent) {
+            if(parent != hdr && H5AC_unpin_entry(parent) < 0)
+                HGOTO_ERROR(H5E_BTREE, H5E_CANTUNPIN, FAIL, "unable to unpin parent entry")
+            parent = NULL;
+        } /* end if */
+
         /* Locate node pointer for child */
         cmp = H5B2_locate_record(hdr->cls, internal->nrec, hdr->nat_off, internal->int_native, udata, &idx);
         if(cmp > 0)
@@ -443,9 +457,13 @@ H5B2_get_node_info_test(H5B2_t *bt2, hid_t dxpl_id, void *udata,
             next_node_ptr = internal->node_ptrs[idx];
 
             /* Unlock current node */
-            if(H5AC_unprotect(hdr->f, dxpl_id, H5AC_BT2_INT, curr_node_ptr.addr, internal, H5AC__NO_FLAGS_SET) < 0)
+            if(H5AC_unprotect(hdr->f, dxpl_id, H5AC_BT2_INT, curr_node_ptr.addr, internal, hdr->swmr_write ? H5AC__PIN_ENTRY_FLAG : H5AC__NO_FLAGS_SET) < 0)
                 HGOTO_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, FAIL, "unable to release B-tree node")
 
+            /* Keep track of parent if necessary */
+            if(hdr->swmr_write)
+                parent = internal;
+
             /* Set pointer to next node to load */
             curr_node_ptr = next_node_ptr;
         } /* end if */
@@ -470,9 +488,16 @@ H5B2_get_node_info_test(H5B2_t *bt2, hid_t dxpl_id, void *udata,
         H5B2_leaf_t *leaf;          /* Pointer to leaf node in B-tree */
 
         /* Lock B-tree leaf node */
-        if(NULL == (leaf = H5B2_protect_leaf(hdr, dxpl_id, curr_node_ptr.addr, curr_node_ptr.node_nrec, H5AC_READ)))
+        if(NULL == (leaf = H5B2_protect_leaf(hdr, dxpl_id, curr_node_ptr.addr, parent, curr_node_ptr.node_nrec, H5AC_READ)))
             HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree leaf node")
 
+        /* Unpin parent if necessary */
+        if(parent) {
+            if(parent != hdr && H5AC_unpin_entry(parent) < 0)
+                HGOTO_ERROR(H5E_BTREE, H5E_CANTUNPIN, FAIL, "unable to unpin parent entry")
+            parent = NULL;
+        } /* end if */
+
         /* Locate record */
         cmp = H5B2_locate_record(hdr->cls, leaf->nrec, hdr->nat_off, leaf->leaf_native, udata, &idx);
 
@@ -490,6 +515,12 @@ H5B2_get_node_info_test(H5B2_t *bt2, hid_t dxpl_id, void *udata,
     ninfo->nrec = curr_node_ptr.node_nrec;
 
 done:
+    if(parent) {
+        HDassert(ret_value < 0);
+        if(parent != hdr && H5AC_unpin_entry(parent) < 0)
+            HDONE_ERROR(H5E_BTREE, H5E_CANTUNPIN, FAIL, "unable to unpin parent entry")
+    } /* end if */
+
     FUNC_LEAVE_NOAPI(ret_value)
 } /* H5B2_get_node_info_test() */
 
diff --git a/src/H5Bprivate.h b/src/H5Bprivate.h
index a7b303d..1d371a3 100644
--- a/src/H5Bprivate.h
+++ b/src/H5Bprivate.h
@@ -141,8 +141,8 @@ typedef struct H5B_class_t {
     herr_t	(*debug_key)(FILE*, int, int, const void*, const void*);
 
     /* flush dependency functions */
-    herr_t      (*create_flush_dep)(void*, void *, void *);
-    herr_t      (*update_flush_dep)(void*, void *, void *, void*);
+    herr_t      (*create_flush_dep)(void*, void*, void*);
+    herr_t      (*update_flush_dep)(void*, void*, void*, void*);
 } H5B_class_t;
 
 /* Information about B-tree */
diff --git a/src/H5Dbtree2.c b/src/H5Dbtree2.c
index e2a5ca1..27119fc 100644
--- a/src/H5Dbtree2.c
+++ b/src/H5Dbtree2.c
@@ -94,6 +94,10 @@ typedef struct H5D_bt2_it_ud_t {
 typedef struct H5D_bt2_find_ud_t {
     void *rec;    	/* The record to search for */
     unsigned ndims;	/* Number of dimensions for the chunked dataset */
+    const H5O_layout_chunk_t *layout; /* Chunk layout description */
+    const struct H5D_rdcc_t *rdcc; /* Chunk cache.  Only necessary if the index
+                                    * may be modified, and if any chunks in the
+                                    * dset may be cached */
 } H5D_bt2_find_ud_t;
 
 
@@ -112,6 +116,9 @@ static herr_t H5D_bt2_store(void *native, const void *udata);
 static herr_t H5D_bt2_compare(const void *rec1, const void *rec2);
 static herr_t H5D_bt2_encode(uint8_t *raw, const void *native, void *ctx);
 static herr_t H5D_bt2_decode(const uint8_t *raw, void *native, void *ctx);
+static herr_t H5D_bt2_crt_flush_dep(void *_record, void *_udata, void *parent);
+static herr_t H5D_bt2_upd_flush_dep(void *_record, void *_udata,
+    void *old_parent, void *new_parent);
 static herr_t H5D_bt2_debug(FILE *stream, const H5F_t *f, hid_t dxpl_id,
     int indent, int fwidth, const void *record, const void *u_ctx);
 
@@ -120,6 +127,10 @@ static herr_t H5D_bt2_filt_store(void *native, const void *udata);
 static herr_t H5D_bt2_filt_compare(const void *rec1, const void *rec2);
 static herr_t H5D_bt2_filt_encode(uint8_t *raw, const void *native, void *ctx);
 static herr_t H5D_bt2_filt_decode(const uint8_t *raw, void *native, void *ctx);
+static herr_t H5D_bt2_filt_crt_flush_dep(void *_record, void *_udata,
+    void *parent);
+static herr_t H5D_bt2_filt_upd_flush_dep(void *_record, void *_udata,
+    void *old_parent, void *new_parent);
 static herr_t H5D_bt2_filt_debug(FILE *stream, const H5F_t *f, hid_t dxpl_id,
     int indent, int fwidth, const void *record, const void *u_ctx);
 
@@ -144,6 +155,8 @@ static herr_t H5D_bt2_filt_remove_cb(const void *nrecord, void *_udata);
 static herr_t H5D_bt2_mod_filt_cb(void *_record, void *_op_data, hbool_t *changed);
 
 /* Chunked layout indexing callbacks for v2 B-tree indexing */
+static herr_t H5D_bt2_idx_init(const H5D_chk_idx_info_t *idx_info,
+    const H5S_t *space, haddr_t dset_ohdr_addr);
 static herr_t H5D_bt2_idx_create(const H5D_chk_idx_info_t *idx_info);
 static hbool_t H5D_bt2_idx_is_space_alloc(const H5O_storage_chunk_t *storage);
 static herr_t H5D_bt2_idx_insert(const H5D_chk_idx_info_t *idx_info,
@@ -161,6 +174,10 @@ static herr_t H5D_bt2_idx_copy_shutdown(H5O_storage_chunk_t *storage_src,
     H5O_storage_chunk_t *storage_dst, hid_t dxpl_id);
 static herr_t H5D_bt2_idx_size(const H5D_chk_idx_info_t *idx_info, hsize_t *size);
 static herr_t H5D_bt2_idx_reset(H5O_storage_chunk_t *storage, hbool_t reset_addr);
+static htri_t H5D_bt2_idx_support(const H5D_chk_idx_info_t *idx_info,
+    H5D_chunk_ud_t *udata, H5AC_info_t *child_entry);
+static herr_t H5D_bt2_idx_unsupport(const H5D_chk_idx_info_t *idx_info,
+    H5D_chunk_ud_t *udata, H5AC_info_t *child_entry);
 static herr_t H5D_bt2_idx_dump(const H5O_storage_chunk_t *storage,
     FILE *stream);
 static herr_t H5D_bt2_idx_dest(const H5D_chk_idx_info_t *idx_info);
@@ -172,8 +189,8 @@ static herr_t H5D_bt2_idx_dest(const H5D_chk_idx_info_t *idx_info);
 
 /* Chunked dataset I/O ops for v2 B-tree indexing */
 const H5D_chunk_ops_t H5D_COPS_BT2[1] = {{
-    FALSE,
-    NULL, 
+    TRUE,
+    H5D_bt2_idx_init, 
     H5D_bt2_idx_create,
     H5D_bt2_idx_is_space_alloc,
     H5D_bt2_idx_insert,
@@ -186,8 +203,8 @@ const H5D_chunk_ops_t H5D_COPS_BT2[1] = {{
     H5D_bt2_idx_copy_shutdown,
     H5D_bt2_idx_size,
     H5D_bt2_idx_reset,
-    NULL,
-    NULL,
+    H5D_bt2_idx_support,
+    H5D_bt2_idx_unsupport,
     H5D_bt2_idx_dump, 
     H5D_bt2_idx_dest 
 }};
@@ -208,6 +225,8 @@ const H5B2_class_t H5D_BT2[1] = {{  	/* B-tree class information */
     H5D_bt2_compare,   		/* Record comparison callback */
     H5D_bt2_encode,    		/* Record encoding callback */
     H5D_bt2_decode,    		/* Record decoding callback */
+    H5D_bt2_crt_flush_dep,      /* Create flush dependency */
+    H5D_bt2_upd_flush_dep,      /* Update flush dependency */
     H5D_bt2_debug,  		/* Record debugging callback */
     H5D_bt2_crt_dbg_context,  	/* Create debugging context */
     H5D_bt2_dst_dbg_context      /* Destroy debugging context */
@@ -224,6 +243,8 @@ const H5B2_class_t H5D_BT2_FILT[1] = {{	/* B-tree class information */
     H5D_bt2_filt_compare,      	/* Record comparison callback */
     H5D_bt2_filt_encode,       	/* Record encoding callback */
     H5D_bt2_filt_decode,       	/* Record decoding callback */
+    H5D_bt2_filt_crt_flush_dep, /* Create flush dependency */
+    H5D_bt2_filt_upd_flush_dep, /* Update flush dependency */
     H5D_bt2_filt_debug,        	/* Record debugging callback */
     H5D_bt2_crt_dbg_context,   	/* Create debugging context */
     H5D_bt2_dst_dbg_context   	/* Destroy debugging context */
@@ -450,6 +471,89 @@ H5D_bt2_decode(const uint8_t *raw, void *_record, void *_ctx)
 
 
 /*-------------------------------------------------------------------------
+ * Function:    H5D_bt2_crt_flush_dep
+ *
+ * Purpose:     Creates a flush dependency between the specified chunk
+ *              (child) and parent.
+ *
+ * Return:      Success:        0
+ *              Failure:        FAIL
+ *
+ * Programmer:  Neil Fortner
+ *              Tuesday, May 1, 2012
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5D_bt2_crt_flush_dep(void *_record, void *_udata, void *parent)
+{
+    H5D_bt2_rec_t *record = (H5D_bt2_rec_t *)_record;   /* The native record */
+    const H5D_bt2_find_ud_t *udata = (const H5D_bt2_find_ud_t *)_udata; /* User data */
+    int         ret_value = SUCCEED;
+
+    FUNC_ENTER_NOAPI_NOINIT
+
+    HDassert(record);
+    HDassert(udata);
+    HDassert(udata->layout->ndims > 0 && udata->layout->ndims <= H5O_LAYOUT_NDIMS);
+    HDassert(parent);
+
+    /* If there is no rdcc, then there are no cached chunks to create
+     * dependencies on.  This should only happen when copying */
+    if(udata->rdcc)
+        /* Delegate to chunk routine */
+        if(H5D_chunk_create_flush_dep(udata->rdcc, udata->layout, record->offset, parent) < 0)
+            HGOTO_ERROR(H5E_DATASET, H5E_CANTDEPEND, FAIL, "unable to create flush dependency")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5D_bt2_crt_flush_dep() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5D_bt2_upd_flush_dep
+ *
+ * Purpose:     Updates the flush dependency of the specified chunk from
+ *              old_parent to new_parent, but only if the current parent
+ *              is cached.  If the chunk is not cached, does nothing.
+ *
+ * Return:      Success:        0
+ *              Failure:        FAIL
+ *
+ * Programmer:  Neil Fortner
+ *              Tuesday, May 1, 2012
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5D_bt2_upd_flush_dep(void *_record, void *_udata, void *old_parent,
+    void *new_parent)
+{
+    H5D_bt2_rec_t *record = (H5D_bt2_rec_t *)_record;   /* The native record */
+    const H5D_bt2_find_ud_t *udata = (const H5D_bt2_find_ud_t *)_udata; /* User data */
+    int         ret_value = SUCCEED;
+
+    FUNC_ENTER_NOAPI_NOINIT
+
+    HDassert(record);
+    HDassert(udata);
+    HDassert(udata->layout->ndims > 0 && udata->layout->ndims <= H5O_LAYOUT_NDIMS);
+    HDassert(old_parent);
+    HDassert(new_parent);
+
+    /* If there is no rdcc, then there are no cached chunks to update
+     * dependencies.  This should only happen when copying */
+    if(udata->rdcc)
+        /* Delegate to chunk routine */
+        if(H5D_chunk_update_flush_dep(udata->rdcc, udata->layout, record->offset, old_parent, new_parent) < 0)
+            HGOTO_ERROR(H5E_DATASET, H5E_CANTDEPEND, FAIL, "unable to update flush dependency")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5D_bt2_upd_flush_dep() */
+
+
+/*-------------------------------------------------------------------------
  * Function:	H5D_bt2_debug
  *
  * Purpose:	Debug native form of record (non-filtered)
@@ -617,6 +721,89 @@ H5D_bt2_filt_decode(const uint8_t *raw, void *_record, void *_ctx)
 
 
 /*-------------------------------------------------------------------------
+ * Function:    H5D_bt2_filt_crt_flush_dep
+ *
+ * Purpose:     Creates a flush dependency between the specified chunk
+ *              (child) and parent.
+ *
+ * Return:      Success:        0
+ *              Failure:        FAIL
+ *
+ * Programmer:  Neil Fortner
+ *              Tuesday, May 1, 2012
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5D_bt2_filt_crt_flush_dep(void *_record, void *_udata, void *parent)
+{
+    H5D_bt2_filt_rec_t *record = (H5D_bt2_filt_rec_t *)_record; /* The native record */
+    const H5D_bt2_find_ud_t *udata = (const H5D_bt2_find_ud_t *)_udata; /* User data */
+    int         ret_value = SUCCEED;
+
+    FUNC_ENTER_NOAPI_NOINIT
+
+    HDassert(record);
+    HDassert(udata);
+    HDassert(udata->layout->ndims > 0 && udata->layout->ndims <= H5O_LAYOUT_NDIMS);
+    HDassert(parent);
+
+    /* If there is no rdcc, then there are no cached chunks to create
+     * dependencies on.  This should only happen when copying */
+    if(udata->rdcc)
+        /* Delegate to chunk routine */
+        if(H5D_chunk_create_flush_dep(udata->rdcc, udata->layout, record->offset, parent) < 0)
+            HGOTO_ERROR(H5E_DATASET, H5E_CANTDEPEND, FAIL, "unable to create flush dependency")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5D_bt2_filt_crt_flush_dep() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5D_bt2_filt_upd_flush_dep
+ *
+ * Purpose:     Updates the flush dependency of the specified chunk from
+ *              old_parent to new_parent, but only if the current parent
+ *              is cached.  If the chunk is not cached, does nothing.
+ *
+ * Return:      Success:        0
+ *              Failure:        FAIL
+ *
+ * Programmer:  Neil Fortner
+ *              Tuesday, May 1, 2012
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5D_bt2_filt_upd_flush_dep(void *_record, void *_udata, void *old_parent,
+    void *new_parent)
+{
+    H5D_bt2_filt_rec_t *record = (H5D_bt2_filt_rec_t *)_record; /* The native record */
+    const H5D_bt2_find_ud_t *udata = (const H5D_bt2_find_ud_t *)_udata; /* User data */
+    int         ret_value = SUCCEED;
+
+    FUNC_ENTER_NOAPI_NOINIT
+
+    HDassert(record);
+    HDassert(udata);
+    HDassert(udata->layout->ndims > 0 && udata->layout->ndims <= H5O_LAYOUT_NDIMS);
+    HDassert(old_parent);
+    HDassert(new_parent);
+
+    /* If there is no rdcc, then there are no cached chunks to update
+     * dependencies.  This should only happen when copying */
+    if(udata->rdcc)
+        /* Delegate to chunk routine */
+        if(H5D_chunk_update_flush_dep(udata->rdcc, udata->layout, record->offset, old_parent, new_parent) < 0)
+            HGOTO_ERROR(H5E_DATASET, H5E_CANTDEPEND, FAIL, "unable to update flush dependency")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5D_btree_filt_upd_flush_dep() */
+
+
+/*-------------------------------------------------------------------------
  * Function:	H5D_bt2_filt_debug
  *
  * Purpose:	Debug native form of record (filterd)
@@ -758,6 +945,33 @@ H5D_bt2_dst_dbg_context(void *_u_ctx)
 
 
 /*-------------------------------------------------------------------------
+ * Function:    H5D_bt2_idx_init
+ *
+ * Purpose:     Initialize the indexing information for a dataset.
+ *
+ * Return:      Non-negative on success/Negative on failure
+ *
+ * Programmer:  Neil Fortner
+ *              Wednensday, May 23, 2012
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5D_bt2_idx_init(const H5D_chk_idx_info_t UNUSED *idx_info,
+    const H5S_t UNUSED *space, haddr_t dset_ohdr_addr)
+{
+    FUNC_ENTER_NOAPI_NOINIT_NOERR
+
+    /* Check args */
+    HDassert(H5F_addr_defined(dset_ohdr_addr));
+
+    idx_info->storage->u.btree2.dset_ohdr_addr = dset_ohdr_addr;
+
+    FUNC_LEAVE_NOAPI(SUCCEED)
+} /* end H5D_bt2_idx_init() */
+
+
+/*-------------------------------------------------------------------------
  * Function:	H5D_bt2_idx_open()
  *
  * Purpose:	Opens an existing v2 B-tree.
@@ -778,6 +992,8 @@ static herr_t
 H5D_bt2_idx_open(const H5D_chk_idx_info_t *idx_info)
 {
     H5D_bt2_ctx_ud_t u_ctx;	/* user data for creating context */
+    H5O_loc_t oloc;             /* Temporary object header location for dataset */
+    H5O_t *oh = NULL;           /* Dataset's object header */
     herr_t ret_value = SUCCEED; /* Return value */
 
     FUNC_ENTER_NOAPI_NOINIT
@@ -797,11 +1013,27 @@ H5D_bt2_idx_open(const H5D_chk_idx_info_t *idx_info)
     u_ctx.ndims = idx_info->layout->ndims - 1;
     u_ctx.chunk_size = idx_info->layout->size;
 
+    /* Check for SWMR writes to the file */
+    if(H5F_INTENT(idx_info->f) & H5F_ACC_SWMR_WRITE) {
+        /* Set up object header location for dataset */
+        H5O_loc_reset(&oloc);
+        oloc.file = idx_info->f;
+        oloc.addr = idx_info->storage->u.btree.dset_ohdr_addr;
+
+        /* Pin the dataset's object header */
+        /*!FIXME change to use ohdr proxy once those changes are merged -NAF */
+        if(NULL == (oh = H5O_pin(&oloc, idx_info->dxpl_id)))
+            HGOTO_ERROR(H5E_DATASET, H5E_CANTPIN, FAIL, "unable to pin dataset object header")
+    } /* end if */
+
     /* Open v2 B-tree for the chunk index */
-    if(NULL == (idx_info->storage->u.btree2.bt2 = H5B2_open(idx_info->f, idx_info->dxpl_id, idx_info->storage->idx_addr , &u_ctx)))
+    if(NULL == (idx_info->storage->u.btree2.bt2 = H5B2_open(idx_info->f, idx_info->dxpl_id, idx_info->storage->idx_addr , &u_ctx, oh)))
 	HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "can't open v2 B-tree for tracking chunked dataset")
 
 done:
+    if(oh && H5O_unpin(oh) < 0)
+        HDONE_ERROR(H5E_DATASET, H5E_CANTUNPIN, FAIL, "unable to unpin dataset object header")
+
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5D_bt2_idx_open() */
 
@@ -822,6 +1054,8 @@ H5D_bt2_idx_create(const H5D_chk_idx_info_t *idx_info)
 {
     H5B2_create_t bt2_cparam;           /* v2 B-tree creation parameters */
     H5D_bt2_ctx_ud_t u_ctx;		/* data for context call */
+    H5O_loc_t oloc;                     /* Temporary object header location for dataset */
+    H5O_t *oh = NULL;                   /* Dataset's object header */
     herr_t ret_value = SUCCEED;         /* Return value */
 
     FUNC_ENTER_NOAPI_NOINIT
@@ -833,7 +1067,7 @@ H5D_bt2_idx_create(const H5D_chk_idx_info_t *idx_info)
     HDassert(idx_info->layout);
     HDassert(idx_info->storage);
     HDassert(!H5F_addr_defined(idx_info->storage->idx_addr));
-    
+
     bt2_cparam.rrec_size = H5F_SIZEOF_ADDR(idx_info->f)	/* Address of chunk */
 		  + (idx_info->layout->ndims - 1) * 8;	/* # of dimensions x 64-bit chunk offsets */
 
@@ -863,8 +1097,21 @@ H5D_bt2_idx_create(const H5D_chk_idx_info_t *idx_info)
     u_ctx.ndims = idx_info->layout->ndims - 1;
     u_ctx.chunk_size = idx_info->layout->size;
 
+    /* Check for SWMR writes to the file */
+    if(H5F_INTENT(idx_info->f) & H5F_ACC_SWMR_WRITE) {
+        /* Set up object header location for dataset */
+        H5O_loc_reset(&oloc);
+        oloc.file = idx_info->f;
+        oloc.addr = idx_info->storage->u.btree.dset_ohdr_addr;
+
+        /* Pin the dataset's object header */
+        /*!FIXME change to use ohdr proxy once those changes are merged -NAF */
+        if(NULL == (oh = H5O_pin(&oloc, idx_info->dxpl_id)))
+            HGOTO_ERROR(H5E_DATASET, H5E_CANTPIN, FAIL, "unable to pin dataset object header")
+    } /* end if */
+
     /* Create the v2 B-tree for the chunked dataset */
-    if(NULL == (idx_info->storage->u.btree2.bt2 = H5B2_create(idx_info->f, idx_info->dxpl_id, &bt2_cparam, &u_ctx)))
+    if(NULL == (idx_info->storage->u.btree2.bt2 = H5B2_create(idx_info->f, idx_info->dxpl_id, &bt2_cparam, &u_ctx, oh)))
         HGOTO_ERROR(H5E_DATASET, H5E_CANTCREATE, FAIL, "can't create v2 B-tree for tracking chunked dataset")
 
     /* Retrieve the v2 B-tree's address in the file */
@@ -872,6 +1119,9 @@ H5D_bt2_idx_create(const H5D_chk_idx_info_t *idx_info)
         HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "can't get v2 B-tree address for tracking chunked dataset")
 
 done:
+    if(oh && H5O_unpin(oh) < 0)
+        HDONE_ERROR(H5E_DATASET, H5E_CANTUNPIN, FAIL, "unable to unpin dataset object header")
+
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5D_bt2_idx_create() */
 
@@ -1015,6 +1265,8 @@ H5D_bt2_idx_insert(const H5D_chk_idx_info_t *idx_info, H5D_chunk_ud_t *udata)
 	/* Prepare user data for compare callback */
 	bt2_udata.rec = &rec;
 	bt2_udata.ndims = idx_info->layout->ndims - 1;
+	bt2_udata.layout = idx_info->layout;
+	bt2_udata.rdcc = udata->common.rdcc;
 
 	/* Try to find the chunked record */
 	if(H5B2_find(bt2, idx_info->dxpl_id, &bt2_udata, H5D_bt2_filt_found_cb, &found_rec) < 0)
@@ -1027,10 +1279,12 @@ H5D_bt2_idx_insert(const H5D_chk_idx_info_t *idx_info, H5D_chunk_ud_t *udata)
 
             /* Check for chunk being same size */
             if(udata->nbytes != found_rec.nbytes) {
-		/* Free the original chunk */
-		H5_CHECK_OVERFLOW(found_rec.nbytes, uint32_t, hsize_t);
-		if(H5MF_xfree(idx_info->f, H5FD_MEM_DRAW, idx_info->dxpl_id, found_rec.addr, (hsize_t)found_rec.nbytes) < 0)
-                    HGOTO_ERROR(H5E_DATASET, H5E_CANTFREE, FAIL, "unable to free chunk")
+		/* Free the original chunk if not doing SWMR writes */
+		if(!(H5F_INTENT(idx_info->f) & H5F_ACC_SWMR_WRITE)) {
+                    H5_CHECK_OVERFLOW(found_rec.nbytes, uint32_t, hsize_t);
+                    if(H5MF_xfree(idx_info->f, H5FD_MEM_DRAW, idx_info->dxpl_id, found_rec.addr, (hsize_t)found_rec.nbytes) < 0)
+                        HGOTO_ERROR(H5E_DATASET, H5E_CANTFREE, FAIL, "unable to free chunk")
+                } /* end if */
 
 		/* Allocate a new chunk */
 		H5_CHECK_OVERFLOW(udata->nbytes, uint32_t, hsize_t);
@@ -1071,6 +1325,8 @@ H5D_bt2_idx_insert(const H5D_chk_idx_info_t *idx_info, H5D_chunk_ud_t *udata)
 	/* Prepare user data for compare callback */
 	bt2_udata.rec = &rec;
 	bt2_udata.ndims = idx_info->layout->ndims - 1;
+        bt2_udata.layout = idx_info->layout;
+        bt2_udata.rdcc = udata->common.rdcc;
 
 	for(u = 0; u < (idx_info->layout->ndims - 1); u++)
 	    rec.offset[u] = udata->common.offset[u];
@@ -1203,6 +1459,8 @@ H5D_bt2_idx_get_addr(const H5D_chk_idx_info_t *idx_info, H5D_chunk_ud_t *udata)
 	/* Prepare user data for compare callback */
 	bt2_udata.rec = &search_rec;
 	bt2_udata.ndims = idx_info->layout->ndims - 1;
+        bt2_udata.layout = idx_info->layout;
+        bt2_udata.rdcc = udata->common.rdcc;
 
 	/* Go get chunk information from v2 B-tree */
 	if(H5B2_find(bt2, idx_info->dxpl_id, &bt2_udata, H5D_bt2_filt_found_cb, &found_rec) < 0)
@@ -1227,6 +1485,8 @@ H5D_bt2_idx_get_addr(const H5D_chk_idx_info_t *idx_info, H5D_chunk_ud_t *udata)
 	/* Prepare user data for compare callback */
 	bt2_udata.rec = &search_rec;
 	bt2_udata.ndims = idx_info->layout->ndims - 1;
+        bt2_udata.layout = idx_info->layout;
+        bt2_udata.rdcc = udata->common.rdcc;
 
 	/* Go get chunk information from v2 B-tree */
 	if(H5B2_find(bt2, idx_info->dxpl_id, &bt2_udata, H5D_bt2_found_cb, &found_rec) < 0)
@@ -1481,8 +1741,10 @@ H5D_bt2_idx_remove(const H5D_chk_idx_info_t *idx_info, H5D_chunk_common_ud_t *ud
 
 	bt2_udata.rec = &search_rec;
 	bt2_udata.ndims = idx_info->layout->ndims - 1;
+        bt2_udata.layout = idx_info->layout;
+        bt2_udata.rdcc = udata->rdcc;
 
-	if(H5B2_remove(bt2, idx_info->dxpl_id, &bt2_udata, H5D_bt2_filt_remove_cb, &remove_udata) < 0)
+	if(H5B2_remove(bt2, idx_info->dxpl_id, &bt2_udata, (H5F_INTENT(idx_info->f) & H5F_ACC_SWMR_WRITE) ? NULL : H5D_bt2_filt_remove_cb, &remove_udata) < 0)
 	    HGOTO_ERROR(H5E_DATASET, H5E_CANTREMOVE, FAIL, "can't remove object from B-tree")
     } /* end if */
     else { /* non-filtered chunk */
@@ -1496,8 +1758,10 @@ H5D_bt2_idx_remove(const H5D_chk_idx_info_t *idx_info, H5D_chunk_common_ud_t *ud
 
 	bt2_udata.rec = &search_rec;
 	bt2_udata.ndims = idx_info->layout->ndims - 1;
+        bt2_udata.layout = idx_info->layout;
+        bt2_udata.rdcc = udata->rdcc;
 
-	if(H5B2_remove(bt2, idx_info->dxpl_id, &bt2_udata, H5D_bt2_remove_cb, &remove_udata) < 0)
+	if(H5B2_remove(bt2, idx_info->dxpl_id, &bt2_udata, (H5F_INTENT(idx_info->f) & H5F_ACC_SWMR_WRITE) ? NULL : H5D_bt2_remove_cb, &remove_udata) < 0)
 	    HGOTO_ERROR(H5E_DATASET, H5E_CANTREMOVE, FAIL, "can't remove object from B-tree")
     } /* end else */
 
@@ -1532,6 +1796,8 @@ H5D_bt2_idx_delete(const H5D_chk_idx_info_t *idx_info)
     H5D_bt2_remove_ud_t remove_udata;	/* User data for removal callback */
     H5B2_remove_t remove_op;		/* The removal callback */
     H5D_bt2_ctx_ud_t u_ctx;		/* data for context call */
+    H5O_loc_t oloc;                     /* Temporary object header location for dataset */
+    H5O_t *oh = NULL;                   /* Dataset's object header */
     herr_t ret_value = SUCCEED;     	/* Return value */
 
     FUNC_ENTER_NOAPI_NOINIT
@@ -1554,22 +1820,43 @@ H5D_bt2_idx_delete(const H5D_chk_idx_info_t *idx_info)
 	remove_udata.f = idx_info->f;
 	remove_udata.dxpl_id = idx_info->dxpl_id;
 
-	if(idx_info->pline->nused > 0) /* filtered */
-            remove_op = H5D_bt2_filt_remove_cb;
-        else { /* non-filtered */
-            remove_op = H5D_bt2_remove_cb;
-            remove_udata.unfilt_size = idx_info->layout->size;
-        }
+	/* Set remove operation.  Do not remove chunks in SWMR_WRITE mode */
+        if(H5F_INTENT(idx_info->f) & H5F_ACC_SWMR_WRITE)
+            remove_op = NULL;
+        else {
+            if(idx_info->pline->nused > 0) /* filtered */
+                remove_op = H5D_bt2_filt_remove_cb;
+            else { /* non-filtered */
+                remove_op = H5D_bt2_remove_cb;
+                remove_udata.unfilt_size = idx_info->layout->size;
+            } /* end else */
+        } /* end else */
+
+        /* Check for SWMR writes to the file */
+        if(H5F_INTENT(idx_info->f) & H5F_ACC_SWMR_WRITE) {
+            /* Set up object header location for dataset */
+            H5O_loc_reset(&oloc);
+            oloc.file = idx_info->f;
+            oloc.addr = idx_info->storage->u.btree.dset_ohdr_addr;
+
+            /* Pin the dataset's object header */
+            /*!FIXME change to use ohdr proxy once those changes are merged -NAF */
+            if(NULL == (oh = H5O_pin(&oloc, idx_info->dxpl_id)))
+                HGOTO_ERROR(H5E_DATASET, H5E_CANTPIN, FAIL, "unable to pin dataset object header")
+        } /* end if */
 
 	/* Delete the v2 B-tree */
 	/*(space in the file for each object is freed in the 'remove' callback) */
-	if(H5B2_delete(idx_info->f, idx_info->dxpl_id, idx_info->storage->idx_addr, &u_ctx, remove_op, &remove_udata) < 0)
+	if(H5B2_delete(idx_info->f, idx_info->dxpl_id, idx_info->storage->idx_addr, &u_ctx, oh, remove_op, &remove_udata) < 0)
 	    HGOTO_ERROR(H5E_DATASET, H5E_CANTDELETE, FAIL, "can't delete v2 B-tree")
 
 	idx_info->storage->idx_addr = HADDR_UNDEF;
     } /* end if */
 
 done:
+    if(oh && H5O_unpin(oh) < 0)
+        HDONE_ERROR(H5E_DATASET, H5E_CANTUNPIN, FAIL, "unable to unpin dataset object header")
+
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5D_bt2_idx_delete() */
 
@@ -1621,7 +1908,7 @@ H5D_bt2_idx_copy_setup(const H5D_chk_idx_info_t *idx_info_src,
     if(H5D_bt2_idx_create(idx_info_dst) < 0)
         HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "unable to initialize chunked storage")
     HDassert(H5F_addr_defined(idx_info_dst->storage->idx_addr));
-    
+
     /* Reset metadata tag */
     H5_END_TAG(FAIL);
 
@@ -1747,6 +2034,146 @@ H5D_bt2_idx_reset(H5O_storage_chunk_t *storage, hbool_t reset_addr)
 
 
 /*-------------------------------------------------------------------------
+ * Function:    H5D_bt2_idx_support
+ *
+ * Purpose:     Create a dependency between a chunk [proxy] and the index
+ *              metadata that contains the record for the chunk.
+ *
+ * Return:      Non-negative on success/Negative on failure
+ *
+ * Programmer:  Neil Fortner
+ *              Monday, May 14, 2012
+ *
+ *-------------------------------------------------------------------------
+ */
+static htri_t
+H5D_bt2_idx_support(const H5D_chk_idx_info_t *idx_info, H5D_chunk_ud_t *udata,
+    H5AC_info_t *child_entry)
+{
+    H5D_bt2_find_ud_t bt2_udata;        /* User data for v2 B-tree calls */
+    unsigned u;                         /* Local index variable */
+    htri_t ret_value;                   /* Return value */
+
+    FUNC_ENTER_NOAPI_NOINIT
+
+    /* Check args */
+    HDassert(idx_info);
+    HDassert(idx_info->f);
+    HDassert(idx_info->pline);
+    HDassert(idx_info->layout);
+    HDassert(idx_info->storage);
+    HDassert(H5F_addr_defined(idx_info->storage->idx_addr));
+    HDassert(udata);
+    HDassert(child_entry);
+    HDassert(H5F_INTENT(idx_info->f) & H5F_ACC_SWMR_WRITE);
+
+    if(idx_info->pline->nused > 0) { /* filtered chunk */
+        H5D_bt2_filt_rec_t   search_rec;        /* Record for searching for object */
+
+        /* Set the chunk offset to be searched for */
+        for(u = 0; u < (idx_info->layout->ndims - 1); u++)
+            search_rec.offset[u] = udata->common.offset[u];
+
+        /* Prepare user data for support callback */
+        bt2_udata.rec = &search_rec;
+        bt2_udata.ndims = idx_info->layout->ndims - 1;
+        bt2_udata.layout = idx_info->layout;
+        bt2_udata.rdcc = udata->common.rdcc;
+    } /* end if */
+    else { /* non-filtered chunk */
+        H5D_bt2_rec_t   search_rec;     /* Record for searching for object */
+
+        /* Set the chunk offset to be searched for */
+        for(u = 0; u < (idx_info->layout->ndims - 1); u++)
+            search_rec.offset[u] = udata->common.offset[u];
+
+        /* Prepare user data for support callback */
+        bt2_udata.rec = &search_rec;
+        bt2_udata.ndims = idx_info->layout->ndims - 1;
+        bt2_udata.layout = idx_info->layout;
+        bt2_udata.rdcc = udata->common.rdcc;
+    } /* end else */
+
+    /* Add the flush dependency on the chunk */
+    if((ret_value = H5B2_support(idx_info->storage->u.btree2.bt2, idx_info->dxpl_id, &bt2_udata, child_entry)) < 0)
+        HGOTO_ERROR(H5E_DATASET, H5E_CANTDEPEND, FAIL, "unable to create flush dependency on b-tree array metadata")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5D_bt2_idx_support() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5D_bt2_idx_unsupport
+ *
+ * Purpose:     Destroy a dependency between a chunk [proxy] and the index
+ *              metadata that contains the record for the chunk.
+ *
+ * Return:      Non-negative on success/Negative on failure
+ *
+ * Programmer:  Neil Fortner
+ *              Monday, May 14, 2012
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5D_bt2_idx_unsupport(const H5D_chk_idx_info_t *idx_info, H5D_chunk_ud_t *udata,
+    H5AC_info_t *child_entry)
+{
+    H5D_bt2_find_ud_t bt2_udata;        /* User data for v2 B-tree calls */
+    unsigned u;                         /* Local index variable */
+    herr_t ret_value;                   /* Return value */
+
+    FUNC_ENTER_NOAPI_NOINIT
+
+    /* Check args */
+    HDassert(idx_info);
+    HDassert(idx_info->f);
+    HDassert(idx_info->pline);
+    HDassert(idx_info->layout);
+    HDassert(idx_info->storage);
+    HDassert(H5F_addr_defined(idx_info->storage->idx_addr));
+    HDassert(udata);
+    HDassert(child_entry);
+    HDassert(H5F_INTENT(idx_info->f) & H5F_ACC_SWMR_WRITE);
+
+    if(idx_info->pline->nused > 0) { /* filtered chunk */
+        H5D_bt2_filt_rec_t   search_rec;        /* Record for searching for object */
+
+        /* Set the chunk offset to be searched for */
+        for(u = 0; u < (idx_info->layout->ndims - 1); u++)
+            search_rec.offset[u] = udata->common.offset[u];
+
+        /* Prepare user data for support callback */
+        bt2_udata.rec = &search_rec;
+        bt2_udata.ndims = idx_info->layout->ndims - 1;
+        bt2_udata.layout = idx_info->layout;
+        bt2_udata.rdcc = udata->common.rdcc;
+    } /* end if */
+    else { /* non-filtered chunk */
+        H5D_bt2_rec_t   search_rec;     /* Record for searching for object */
+
+        /* Set the chunk offset to be searched for */
+        for(u = 0; u < (idx_info->layout->ndims - 1); u++)
+            search_rec.offset[u] = udata->common.offset[u];
+
+        /* Prepare user data for support callback */
+        bt2_udata.rec = &search_rec;
+        bt2_udata.ndims = idx_info->layout->ndims - 1;
+        bt2_udata.layout = idx_info->layout;
+        bt2_udata.rdcc = udata->common.rdcc;
+    } /* end else */
+
+    /* Add the flush dependency on the chunk */
+    if((ret_value = H5B2_unsupport(idx_info->storage->u.btree2.bt2, idx_info->dxpl_id, &bt2_udata, child_entry)) < 0)
+        HGOTO_ERROR(H5E_DATASET, H5E_CANTUNDEPEND, FAIL, "unable to destroy flush dependency on b-tree array metadata")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5D_bt2_idx_unsupport() */
+
+
+/*-------------------------------------------------------------------------
  * Function:	H5D_bt2_idx_dump
  *
  * Purpose:	Dump indexing information to a stream.
diff --git a/src/H5Gbtree2.c b/src/H5Gbtree2.c
index a917eb4..5a0fd80 100644
--- a/src/H5Gbtree2.c
+++ b/src/H5Gbtree2.c
@@ -114,6 +114,8 @@ const H5B2_class_t H5G_BT2_NAME[1]={{   /* B-tree class information */
     H5G_dense_btree2_name_compare,      /* Record comparison callback */
     H5G_dense_btree2_name_encode,       /* Record encoding callback */
     H5G_dense_btree2_name_decode,       /* Record decoding callback */
+    NULL,                               /* Create flush dependency */
+    NULL,                               /* Update flush dependency */
     H5G_dense_btree2_name_debug,        /* Record debugging callback */
     NULL,                               /* Create debugging context */
     NULL                                /* Destroy debugging context */
@@ -130,6 +132,8 @@ const H5B2_class_t H5G_BT2_CORDER[1]={{ /* B-tree class information */
     H5G_dense_btree2_corder_compare,    /* Record comparison callback */
     H5G_dense_btree2_corder_encode,     /* Record encoding callback */
     H5G_dense_btree2_corder_decode,     /* Record decoding callback */
+    NULL,                               /* Create flush dependency */
+    NULL,                               /* Update flush dependency */
     H5G_dense_btree2_corder_debug,      /* Record debugging callback */
     NULL,                               /* Create debugging context */
     NULL                                /* Destroy debugging context */
diff --git a/src/H5Gdense.c b/src/H5Gdense.c
index 841b4d3..e919507 100644
--- a/src/H5Gdense.c
+++ b/src/H5Gdense.c
@@ -326,7 +326,7 @@ HDfprintf(stderr, "%s: fheap_id_len = %Zu\n", FUNC, fheap_id_len);
             fheap_id_len;               /* Fractal heap ID */
     bt2_cparam.split_percent = H5G_NAME_BT2_SPLIT_PERC;
     bt2_cparam.merge_percent = H5G_NAME_BT2_MERGE_PERC;
-    if(NULL == (bt2_name = H5B2_create(f, dxpl_id, &bt2_cparam, NULL)))
+    if(NULL == (bt2_name = H5B2_create(f, dxpl_id, &bt2_cparam, NULL, NULL)))
         HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to create v2 B-tree for name index")
 
     /* Retrieve the v2 B-tree's address in the file */
@@ -346,7 +346,7 @@ HDfprintf(stderr, "%s: linfo->name_bt2_addr = %a\n", FUNC, linfo->name_bt2_addr)
                 fheap_id_len;           /* Fractal heap ID */
         bt2_cparam.split_percent = H5G_CORDER_BT2_SPLIT_PERC;
         bt2_cparam.merge_percent = H5G_CORDER_BT2_MERGE_PERC;
-        if(NULL == (bt2_corder = H5B2_create(f, dxpl_id, &bt2_cparam, NULL)))
+        if(NULL == (bt2_corder = H5B2_create(f, dxpl_id, &bt2_cparam, NULL, NULL)))
             HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to create v2 B-tree for creation order index")
 
         /* Retrieve the v2 B-tree's address in the file */
@@ -438,7 +438,7 @@ HDfprintf(stderr, "%s: HDstrlen(lnk->name) = %Zu, link_size = %Zu\n", FUNC, HDst
         HGOTO_ERROR(H5E_SYM, H5E_CANTINSERT, FAIL, "unable to insert link into fractal heap")
 
     /* Open the name index v2 B-tree */
-    if(NULL == (bt2_name = H5B2_open(f, dxpl_id, linfo->name_bt2_addr, NULL)))
+    if(NULL == (bt2_name = H5B2_open(f, dxpl_id, linfo->name_bt2_addr, NULL, NULL)))
         HGOTO_ERROR(H5E_SYM, H5E_CANTOPENOBJ, FAIL, "unable to open v2 B-tree for name index")
 
     /* Create the callback information for v2 B-tree record insertion */
@@ -460,7 +460,7 @@ HDfprintf(stderr, "%s: HDstrlen(lnk->name) = %Zu, link_size = %Zu\n", FUNC, HDst
     if(linfo->index_corder) {
         /* Open the creation order index v2 B-tree */
         HDassert(H5F_addr_defined(linfo->corder_bt2_addr));
-        if(NULL == (bt2_corder = H5B2_open(f, dxpl_id, linfo->corder_bt2_addr, NULL)))
+        if(NULL == (bt2_corder = H5B2_open(f, dxpl_id, linfo->corder_bt2_addr, NULL, NULL)))
             HGOTO_ERROR(H5E_SYM, H5E_CANTOPENOBJ, FAIL, "unable to open v2 B-tree for creation order index")
 
         /* Insert the record into the creation order index v2 B-tree */
@@ -557,7 +557,7 @@ H5G__dense_lookup(H5F_t *f, hid_t dxpl_id, const H5O_linfo_t *linfo,
         HGOTO_ERROR(H5E_SYM, H5E_CANTOPENOBJ, FAIL, "unable to open fractal heap")
 
     /* Open the name index v2 B-tree */
-    if(NULL == (bt2_name = H5B2_open(f, dxpl_id, linfo->name_bt2_addr, NULL)))
+    if(NULL == (bt2_name = H5B2_open(f, dxpl_id, linfo->name_bt2_addr, NULL, NULL)))
         HGOTO_ERROR(H5E_SYM, H5E_CANTOPENOBJ, FAIL, "unable to open v2 B-tree for name index")
 
     /* Construct the user data for v2 B-tree callback */
@@ -733,7 +733,7 @@ H5G__dense_lookup_by_idx(H5F_t *f, hid_t dxpl_id, const H5O_linfo_t *linfo,
             HGOTO_ERROR(H5E_SYM, H5E_CANTOPENOBJ, FAIL, "unable to open fractal heap")
 
         /* Open the index v2 B-tree */
-        if(NULL == (bt2 = H5B2_open(f, dxpl_id, bt2_addr, NULL)))
+        if(NULL == (bt2 = H5B2_open(f, dxpl_id, bt2_addr, NULL, NULL)))
             HGOTO_ERROR(H5E_SYM, H5E_CANTOPENOBJ, FAIL, "unable to open v2 B-tree for index")
 
         /* Construct the user data for v2 B-tree callback */
@@ -1042,7 +1042,7 @@ H5G__dense_iterate(H5F_t *f, hid_t dxpl_id, const H5O_linfo_t *linfo,
             HGOTO_ERROR(H5E_SYM, H5E_CANTOPENOBJ, FAIL, "unable to open fractal heap")
 
         /* Open the index v2 B-tree */
-        if(NULL == (bt2 = H5B2_open(f, dxpl_id, bt2_addr, NULL)))
+        if(NULL == (bt2 = H5B2_open(f, dxpl_id, bt2_addr, NULL, NULL)))
             HGOTO_ERROR(H5E_SYM, H5E_CANTOPENOBJ, FAIL, "unable to open v2 B-tree for index")
 
         /* Construct the user data for v2 B-tree iterator callback */
@@ -1244,7 +1244,7 @@ H5G__dense_get_name_by_idx(H5F_t *f, hid_t dxpl_id, H5O_linfo_t *linfo,
             HGOTO_ERROR(H5E_SYM, H5E_CANTOPENOBJ, FAIL, "unable to open fractal heap")
 
         /* Open the index v2 B-tree */
-        if(NULL == (bt2 = H5B2_open(f, dxpl_id, bt2_addr, NULL)))
+        if(NULL == (bt2 = H5B2_open(f, dxpl_id, bt2_addr, NULL, NULL)))
             HGOTO_ERROR(H5E_SYM, H5E_CANTOPENOBJ, FAIL, "unable to open v2 B-tree for index")
 
         /* Set up the user data for the v2 B-tree 'record remove' callback */
@@ -1326,7 +1326,7 @@ H5G_dense_remove_fh_cb(const void *obj, size_t UNUSED obj_len, void *_udata)
         H5G_bt2_ud_common_t bt2_udata;         /* Info for B-tree callbacks */
 
         /* Open the creation order index v2 B-tree */
-        if(NULL == (bt2 = H5B2_open(udata->f, udata->dxpl_id, udata->corder_bt2_addr, NULL)))
+        if(NULL == (bt2 = H5B2_open(udata->f, udata->dxpl_id, udata->corder_bt2_addr, NULL, NULL)))
             HGOTO_ERROR(H5E_SYM, H5E_CANTOPENOBJ, FAIL, "unable to open v2 B-tree for creation order index")
 
         /* Set up the user data for the v2 B-tree 'record remove' callback */
@@ -1440,7 +1440,7 @@ H5G__dense_remove(H5F_t *f, hid_t dxpl_id, const H5O_linfo_t *linfo,
         HGOTO_ERROR(H5E_SYM, H5E_CANTOPENOBJ, FAIL, "unable to open fractal heap")
 
     /* Open the name index v2 B-tree */
-    if(NULL == (bt2 = H5B2_open(f, dxpl_id, linfo->name_bt2_addr, NULL)))
+    if(NULL == (bt2 = H5B2_open(f, dxpl_id, linfo->name_bt2_addr, NULL, NULL)))
         HGOTO_ERROR(H5E_SYM, H5E_CANTOPENOBJ, FAIL, "unable to open v2 B-tree for name index")
 
     /* Set up the user data for the v2 B-tree 'record remove' callback */
@@ -1577,7 +1577,7 @@ H5G_dense_remove_by_idx_bt2_cb(const void *_record, void *_bt2_udata)
         } /* end else */
 
         /* Open the index v2 B-tree */
-        if(NULL == (bt2 = H5B2_open(bt2_udata->f, bt2_udata->dxpl_id, bt2_udata->other_bt2_addr, NULL)))
+        if(NULL == (bt2 = H5B2_open(bt2_udata->f, bt2_udata->dxpl_id, bt2_udata->other_bt2_addr, NULL, NULL)))
             HGOTO_ERROR(H5E_SYM, H5E_CANTOPENOBJ, FAIL, "unable to open v2 B-tree for 'other' index")
 
         /* Set the common information for the v2 B-tree remove operation */
@@ -1682,7 +1682,7 @@ H5G__dense_remove_by_idx(H5F_t *f, hid_t dxpl_id, const H5O_linfo_t *linfo,
             HGOTO_ERROR(H5E_SYM, H5E_CANTOPENOBJ, FAIL, "unable to open fractal heap")
 
         /* Open the index v2 B-tree */
-        if(NULL == (bt2 = H5B2_open(f, dxpl_id, bt2_addr, NULL)))
+        if(NULL == (bt2 = H5B2_open(f, dxpl_id, bt2_addr, NULL, NULL)))
             HGOTO_ERROR(H5E_SYM, H5E_CANTOPENOBJ, FAIL, "unable to open v2 B-tree for index")
 
         /* Set up the user data for the v2 B-tree 'remove by index' callback */
@@ -1694,7 +1694,7 @@ H5G__dense_remove_by_idx(H5F_t *f, hid_t dxpl_id, const H5O_linfo_t *linfo,
         udata.grp_full_path_r = grp_full_path_r;
 
         /* Remove the record from the name index v2 B-tree */
-        if(H5B2_remove_by_idx(bt2, dxpl_id, order, n, H5G_dense_remove_by_idx_bt2_cb, &udata) < 0)
+        if(H5B2_remove_by_idx(bt2, dxpl_id, order, n, NULL, H5G_dense_remove_by_idx_bt2_cb, &udata) < 0)
             HGOTO_ERROR(H5E_SYM, H5E_CANTREMOVE, FAIL, "unable to remove link from indexed v2 B-tree")
     } /* end if */
     else {      /* Otherwise, we need to build a table of the links and sort it */
@@ -1776,7 +1776,7 @@ H5G__dense_delete(H5F_t *f, hid_t dxpl_id, H5O_linfo_t *linfo, hbool_t adj_link)
         udata.replace_names = FALSE;
 
         /* Delete the name index, adjusting the ref. count on links removed */
-        if(H5B2_delete(f, dxpl_id, linfo->name_bt2_addr, NULL, H5G_dense_remove_bt2_cb, &udata) < 0)
+        if(H5B2_delete(f, dxpl_id, linfo->name_bt2_addr, NULL, NULL, H5G_dense_remove_bt2_cb, &udata) < 0)
             HGOTO_ERROR(H5E_SYM, H5E_CANTDELETE, FAIL, "unable to delete v2 B-tree for name index")
 
         /* Close the fractal heap */
@@ -1785,7 +1785,7 @@ H5G__dense_delete(H5F_t *f, hid_t dxpl_id, H5O_linfo_t *linfo, hbool_t adj_link)
     } /* end if */
     else {
         /* Delete the name index, without adjusting the ref. count on the links  */
-        if(H5B2_delete(f, dxpl_id, linfo->name_bt2_addr, NULL, NULL, NULL) < 0)
+        if(H5B2_delete(f, dxpl_id, linfo->name_bt2_addr, NULL, NULL, NULL, NULL) < 0)
             HGOTO_ERROR(H5E_SYM, H5E_CANTDELETE, FAIL, "unable to delete v2 B-tree for name index")
     } /* end else */
     linfo->name_bt2_addr = HADDR_UNDEF;
@@ -1794,7 +1794,7 @@ H5G__dense_delete(H5F_t *f, hid_t dxpl_id, H5O_linfo_t *linfo, hbool_t adj_link)
     if(linfo->index_corder) {
         /* Delete the creation order index, without adjusting the ref. count on the links  */
         HDassert(H5F_addr_defined(linfo->corder_bt2_addr));
-        if(H5B2_delete(f, dxpl_id, linfo->corder_bt2_addr, NULL, NULL, NULL) < 0)
+        if(H5B2_delete(f, dxpl_id, linfo->corder_bt2_addr, NULL, NULL, NULL, NULL) < 0)
             HGOTO_ERROR(H5E_SYM, H5E_CANTDELETE, FAIL, "unable to delete v2 B-tree for creation order index")
         linfo->corder_bt2_addr = HADDR_UNDEF;
     } /* end if */
diff --git a/src/H5Gobj.c b/src/H5Gobj.c
index 021f4e1..08091a3 100644
--- a/src/H5Gobj.c
+++ b/src/H5Gobj.c
@@ -342,7 +342,7 @@ H5G__obj_get_linfo(const H5O_loc_t *grp_oloc, H5O_linfo_t *linfo, hid_t dxpl_id)
             /* Check if we are using "dense" link storage */
             if(H5F_addr_defined(linfo->fheap_addr)) {
                 /* Open the name index v2 B-tree */
-                if(NULL == (bt2_name = H5B2_open(grp_oloc->file, dxpl_id, linfo->name_bt2_addr, NULL)))
+                if(NULL == (bt2_name = H5B2_open(grp_oloc->file, dxpl_id, linfo->name_bt2_addr, NULL, NULL)))
                     HGOTO_ERROR(H5E_SYM, H5E_CANTOPENOBJ, FAIL, "unable to open v2 B-tree for name index")
 
                 /* Retrieve # of records in "name" B-tree */
diff --git a/src/H5Goh.c b/src/H5Goh.c
index c6115db..9e8d496 100644
--- a/src/H5Goh.c
+++ b/src/H5Goh.c
@@ -361,7 +361,7 @@ H5O_group_bh_info(H5F_t *f, hid_t dxpl_id, H5O_t *oh, H5_ih_info_t *bh_info)
         /* Check if name index available */
         if(H5F_addr_defined(linfo.name_bt2_addr)) {
             /* Open the name index v2 B-tree */
-            if(NULL == (bt2_name = H5B2_open(f, dxpl_id, linfo.name_bt2_addr, NULL)))
+            if(NULL == (bt2_name = H5B2_open(f, dxpl_id, linfo.name_bt2_addr, NULL, NULL)))
                 HGOTO_ERROR(H5E_SYM, H5E_CANTOPENOBJ, FAIL, "unable to open v2 B-tree for name index")
 
             /* Get name index B-tree size */
@@ -372,7 +372,7 @@ H5O_group_bh_info(H5F_t *f, hid_t dxpl_id, H5O_t *oh, H5_ih_info_t *bh_info)
         /* Check if creation order index available */
 	if(H5F_addr_defined(linfo.corder_bt2_addr)) {
             /* Open the creation order index v2 B-tree */
-            if(NULL == (bt2_corder = H5B2_open(f, dxpl_id, linfo.corder_bt2_addr, NULL)))
+            if(NULL == (bt2_corder = H5B2_open(f, dxpl_id, linfo.corder_bt2_addr, NULL, NULL)))
                 HGOTO_ERROR(H5E_SYM, H5E_CANTOPENOBJ, FAIL, "unable to open v2 B-tree for creation order index")
 
             /* Get creation order index B-tree size */
diff --git a/src/H5Gtest.c b/src/H5Gtest.c
index dfdefda..4d41409 100644
--- a/src/H5Gtest.c
+++ b/src/H5Gtest.c
@@ -408,7 +408,7 @@ H5G__new_dense_info_test(hid_t gid, hsize_t *name_count, hsize_t *corder_count)
         HGOTO_DONE(FAIL)
 
     /* Open the name index v2 B-tree */
-    if(NULL == (bt2_name = H5B2_open(grp->oloc.file, H5AC_dxpl_id, linfo.name_bt2_addr, NULL)))
+    if(NULL == (bt2_name = H5B2_open(grp->oloc.file, H5AC_dxpl_id, linfo.name_bt2_addr, NULL, NULL)))
         HGOTO_ERROR(H5E_SYM, H5E_CANTOPENOBJ, FAIL, "unable to open v2 B-tree for name index")
 
     /* Retrieve # of records in name index */
@@ -418,7 +418,7 @@ H5G__new_dense_info_test(hid_t gid, hsize_t *name_count, hsize_t *corder_count)
     /* Check if there is a creation order index */
     if(H5F_addr_defined(linfo.corder_bt2_addr)) {
         /* Open the creation order index v2 B-tree */
-        if(NULL == (bt2_corder = H5B2_open(grp->oloc.file, H5AC_dxpl_id, linfo.corder_bt2_addr, NULL)))
+        if(NULL == (bt2_corder = H5B2_open(grp->oloc.file, H5AC_dxpl_id, linfo.corder_bt2_addr, NULL, NULL)))
             HGOTO_ERROR(H5E_SYM, H5E_CANTOPENOBJ, FAIL, "unable to open v2 B-tree for creation order index")
 
         /* Retrieve # of records in creation order index */
diff --git a/src/H5HFbtree2.c b/src/H5HFbtree2.c
index 34b74d7..345412f 100644
--- a/src/H5HFbtree2.c
+++ b/src/H5HFbtree2.c
@@ -122,6 +122,8 @@ const H5B2_class_t H5HF_HUGE_BT2_INDIR[1]={{ /* B-tree class information */
     H5HF_huge_bt2_indir_compare,            /* Record comparison callback */
     H5HF_huge_bt2_indir_encode,             /* Record encoding callback */
     H5HF_huge_bt2_indir_decode,             /* Record decoding callback */
+    NULL,                                   /* Create flush dependency */
+    NULL,                                   /* Update flush dependency */
     H5HF_huge_bt2_indir_debug,              /* Record debugging callback */
     H5HF_huge_bt2_crt_dbg_context,          /* Create debugging context */
     H5HF_huge_bt2_dst_context               /* Destroy debugging context */
@@ -138,6 +140,8 @@ const H5B2_class_t H5HF_HUGE_BT2_FILT_INDIR[1]={{ /* B-tree class information */
     H5HF_huge_bt2_filt_indir_compare,       /* Record comparison callback */
     H5HF_huge_bt2_filt_indir_encode,        /* Record encoding callback */
     H5HF_huge_bt2_filt_indir_decode,        /* Record decoding callback */
+    NULL,                                   /* Create flush dependency */
+    NULL,                                   /* Update flush dependency */
     H5HF_huge_bt2_filt_indir_debug,         /* Record debugging callback */
     H5HF_huge_bt2_crt_dbg_context,          /* Create debugging context */
     H5HF_huge_bt2_dst_context               /* Destroy debugging context */
@@ -154,6 +158,8 @@ const H5B2_class_t H5HF_HUGE_BT2_DIR[1]={{  /* B-tree class information */
     H5HF_huge_bt2_dir_compare,              /* Record comparison callback */
     H5HF_huge_bt2_dir_encode,               /* Record encoding callback */
     H5HF_huge_bt2_dir_decode,               /* Record decoding callback */
+    NULL,                                   /* Create flush dependency */
+    NULL,                                   /* Update flush dependency */
     H5HF_huge_bt2_dir_debug,                /* Record debugging callback */
     H5HF_huge_bt2_crt_dbg_context,          /* Create debugging context */
     H5HF_huge_bt2_dst_context               /* Destroy debugging context */
@@ -170,6 +176,8 @@ const H5B2_class_t H5HF_HUGE_BT2_FILT_DIR[1]={{ /* B-tree class information */
     H5HF_huge_bt2_filt_dir_compare,         /* Record comparison callback */
     H5HF_huge_bt2_filt_dir_encode,          /* Record encoding callback */
     H5HF_huge_bt2_filt_dir_decode,          /* Record decoding callback */
+    NULL,                                   /* Create flush dependency */
+    NULL,                                   /* Update flush dependency */
     H5HF_huge_bt2_filt_dir_debug,           /* Record debugging callback */
     H5HF_huge_bt2_crt_dbg_context,          /* Create debugging context */
     H5HF_huge_bt2_dst_context               /* Destroy debugging context */
diff --git a/src/H5HFhuge.c b/src/H5HFhuge.c
index 6f0b48e..786c850 100644
--- a/src/H5HFhuge.c
+++ b/src/H5HFhuge.c
@@ -157,7 +157,7 @@ H5HF_huge_bt2_create(H5HF_hdr_t *hdr, hid_t dxpl_id)
     bt2_cparam.merge_percent = H5HF_HUGE_BT2_MERGE_PERC;
 
     /* Create v2 B-tree for tracking 'huge' objects */
-    if(NULL == (hdr->huge_bt2 = H5B2_create(hdr->f, dxpl_id, &bt2_cparam, hdr->f)))
+    if(NULL == (hdr->huge_bt2 = H5B2_create(hdr->f, dxpl_id, &bt2_cparam, hdr->f, NULL)))
         HGOTO_ERROR(H5E_HEAP, H5E_CANTCREATE, FAIL, "can't create v2 B-tree for tracking 'huge' heap objects")
 
     /* Retrieve the v2 B-tree's address in the file */
@@ -339,7 +339,7 @@ HDfprintf(stderr, "%s: obj_size = %Zu\n", FUNC, obj_size);
         /* Check if v2 B-tree is open yet */
         if(NULL == hdr->huge_bt2) {
             /* Open existing v2 B-tree */
-            if(NULL == (hdr->huge_bt2 = H5B2_open(hdr->f, dxpl_id, hdr->huge_bt2_addr, hdr->f)))
+            if(NULL == (hdr->huge_bt2 = H5B2_open(hdr->f, dxpl_id, hdr->huge_bt2_addr, hdr->f, NULL)))
                 HGOTO_ERROR(H5E_HEAP, H5E_CANTOPENOBJ, FAIL, "unable to open v2 B-tree for tracking 'huge' heap objects")
         } /* end if */
     } /* end else */
@@ -545,7 +545,7 @@ H5HF_huge_get_obj_len(H5HF_hdr_t *hdr, hid_t dxpl_id, const uint8_t *id,
         /* Check if v2 B-tree is open yet */
         if(NULL == hdr->huge_bt2) {
             /* Open existing v2 B-tree */
-            if(NULL == (hdr->huge_bt2 = H5B2_open(hdr->f, dxpl_id, hdr->huge_bt2_addr, hdr->f)))
+            if(NULL == (hdr->huge_bt2 = H5B2_open(hdr->f, dxpl_id, hdr->huge_bt2_addr, hdr->f, NULL)))
                 HGOTO_ERROR(H5E_HEAP, H5E_CANTOPENOBJ, FAIL, "unable to open v2 B-tree for tracking 'huge' heap objects")
         } /* end if */
 
@@ -636,7 +636,7 @@ H5HF_huge_op_real(H5HF_hdr_t *hdr, hid_t dxpl_id, const uint8_t *id,
         /* Check if v2 B-tree is open yet */
         if(NULL == hdr->huge_bt2) {
             /* Open existing v2 B-tree */
-            if(NULL == (hdr->huge_bt2 = H5B2_open(hdr->f, dxpl_id, hdr->huge_bt2_addr, hdr->f)))
+            if(NULL == (hdr->huge_bt2 = H5B2_open(hdr->f, dxpl_id, hdr->huge_bt2_addr, hdr->f, NULL)))
                 HGOTO_ERROR(H5E_HEAP, H5E_CANTOPENOBJ, FAIL, "unable to open v2 B-tree for tracking 'huge' heap objects")
         } /* end if */
 
@@ -784,7 +784,7 @@ H5HF_huge_write(H5HF_hdr_t *hdr, hid_t dxpl_id, const uint8_t *id,
         /* Check if v2 B-tree is open yet */
         if(NULL == hdr->huge_bt2) {
             /* Open existing v2 B-tree */
-            if(NULL == (hdr->huge_bt2 = H5B2_open(hdr->f, dxpl_id, hdr->huge_bt2_addr, hdr->f)))
+            if(NULL == (hdr->huge_bt2 = H5B2_open(hdr->f, dxpl_id, hdr->huge_bt2_addr, hdr->f, NULL)))
                 HGOTO_ERROR(H5E_HEAP, H5E_CANTOPENOBJ, FAIL, "unable to open v2 B-tree for tracking 'huge' heap objects")
         } /* end if */
 
@@ -914,7 +914,7 @@ H5HF_huge_remove(H5HF_hdr_t *hdr, hid_t dxpl_id, const uint8_t *id)
     /* Check if v2 B-tree is open yet */
     if(NULL == hdr->huge_bt2) {
         /* Open existing v2 B-tree */
-        if(NULL == (hdr->huge_bt2 = H5B2_open(hdr->f, dxpl_id, hdr->huge_bt2_addr, hdr->f)))
+        if(NULL == (hdr->huge_bt2 = H5B2_open(hdr->f, dxpl_id, hdr->huge_bt2_addr, hdr->f, NULL)))
             HGOTO_ERROR(H5E_HEAP, H5E_CANTOPENOBJ, FAIL, "unable to open v2 B-tree for tracking 'huge' heap objects")
     } /* end if */
 
@@ -1037,7 +1037,7 @@ H5HF_huge_term(H5HF_hdr_t *hdr, hid_t dxpl_id)
 
         /* Delete the v2 B-tree */
         /* (any v2 B-tree class will work here) */
-        if(H5B2_delete(hdr->f, dxpl_id, hdr->huge_bt2_addr, hdr->f, NULL, NULL) < 0)
+        if(H5B2_delete(hdr->f, dxpl_id, hdr->huge_bt2_addr, hdr->f, NULL, NULL, NULL) < 0)
             HGOTO_ERROR(H5E_HEAP, H5E_CANTDELETE, FAIL, "can't delete v2 B-tree")
 
         /* Reset the information about 'huge' objects in the file */
@@ -1105,7 +1105,7 @@ H5HF_huge_delete(H5HF_hdr_t *hdr, hid_t dxpl_id)
     } /* end else */
 
     /* Delete the v2 B-tree */
-    if(H5B2_delete(hdr->f, dxpl_id, hdr->huge_bt2_addr, hdr->f, op, &udata) < 0)
+    if(H5B2_delete(hdr->f, dxpl_id, hdr->huge_bt2_addr, hdr->f, NULL, op, &udata) < 0)
         HGOTO_ERROR(H5E_HEAP, H5E_CANTDELETE, FAIL, "can't delete v2 B-tree")
 
 done:
diff --git a/src/H5HFstat.c b/src/H5HFstat.c
index b0e1987..802a332 100644
--- a/src/H5HFstat.c
+++ b/src/H5HFstat.c
@@ -155,7 +155,7 @@ H5HF_size(const H5HF_t *fh, hid_t dxpl_id, hsize_t *heap_size)
     /* Check for B-tree storage of huge objects in fractal heap */
     if(H5F_addr_defined(hdr->huge_bt2_addr)) {
         /* Open the huge object index v2 B-tree */
-        if(NULL == (bt2 = H5B2_open(hdr->f, dxpl_id, hdr->huge_bt2_addr, hdr->f)))
+        if(NULL == (bt2 = H5B2_open(hdr->f, dxpl_id, hdr->huge_bt2_addr, hdr->f, NULL)))
             HGOTO_ERROR(H5E_HEAP, H5E_CANTOPENOBJ, FAIL, "unable to open v2 B-tree for tracking 'huge' objects")
 
         /* Get the B-tree storage */
diff --git a/src/H5Oainfo.c b/src/H5Oainfo.c
index b207ea2..b6aa4fc 100644
--- a/src/H5Oainfo.c
+++ b/src/H5Oainfo.c
@@ -333,7 +333,7 @@ H5O_ainfo_free(void *mesg)
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5O_ainfo_delete(H5F_t *f, hid_t dxpl_id, H5O_t UNUSED *open_oh, void *_mesg)
+H5O_ainfo_delete(H5F_t *f, hid_t dxpl_id, H5O_t *open_oh, void *_mesg)
 {
     H5O_ainfo_t *ainfo = (H5O_ainfo_t *)_mesg;
     herr_t ret_value = SUCCEED;   /* Return value */
@@ -346,7 +346,8 @@ H5O_ainfo_delete(H5F_t *f, hid_t dxpl_id, H5O_t UNUSED *open_oh, void *_mesg)
 
     /* If the object is using "dense" attribute storage, delete it */
     if(H5F_addr_defined(ainfo->fheap_addr))
-        if(H5A_dense_delete(f, dxpl_id, ainfo) < 0)
+        /*!FIXME use ohdr proxy -NAF */
+        if(H5A_dense_delete(f, dxpl_id, ainfo, open_oh) < 0)
             HGOTO_ERROR(H5E_OHDR, H5E_CANTFREE, FAIL, "unable to free dense attribute storage")
 
 done:
@@ -427,12 +428,14 @@ H5O_ainfo_copy_file(H5F_t *file_src, void *mesg_src, H5F_t *file_dst,
     *ainfo_dst = *ainfo_src;
 
     if(H5F_addr_defined(ainfo_src->fheap_addr)) {
-        /* copy dense attribute */
-        
+        /* Prepare to copy dense attributes - actual copy in post_copy */
+
         /* Set copied metadata tag */
         H5_BEGIN_TAG(dxpl_id, H5AC__COPIED_TAG, NULL);
 
-        if(H5A_dense_create(file_dst, dxpl_id, ainfo_dst) < 0)
+        /*!FIXME Must pass something for the parent, once we have a way to
+         * depend on an object being copied (ohdr proxy?) -NAF */
+        if(H5A_dense_create(file_dst, dxpl_id, ainfo_dst, NULL) < 0)
             HGOTO_ERROR(H5E_OHDR, H5E_CANTINIT, NULL, "unable to create dense storage for attributes")
 
         /* Reset metadata tag */
diff --git a/src/H5Oattribute.c b/src/H5Oattribute.c
index 30ec732..9370aa9 100644
--- a/src/H5Oattribute.c
+++ b/src/H5Oattribute.c
@@ -280,7 +280,8 @@ H5O_attr_create(const H5O_loc_t *loc, hid_t dxpl_id, H5A_t *attr)
                 H5O_mesg_operator_t op;         /* Wrapper for operator */
 
                 /* Create dense storage for attributes */
-                if(H5A_dense_create(loc->file, dxpl_id, &ainfo) < 0)
+                /*!FIXME use ohdr proxy -NAF */
+                if(H5A_dense_create(loc->file, dxpl_id, &ainfo, oh) < 0)
                     HGOTO_ERROR(H5E_OHDR, H5E_CANTINIT, FAIL, "unable to create dense storage for attributes")
 
                 /* Set up user data for callback */
@@ -507,7 +508,8 @@ H5O_attr_open_by_name(const H5O_loc_t *loc, const char *name, hid_t dxpl_id)
         /* Check for attributes in dense storage */
         if(H5F_addr_defined(ainfo.fheap_addr)) {
             /* Open attribute with dense storage */
-            if(NULL == (opened_attr = H5A_dense_open(loc->file, dxpl_id, &ainfo, name)))
+            /*!FIXME use ohdr proxy -NAF */
+            if(NULL == (opened_attr = H5A_dense_open(loc->file, dxpl_id, &ainfo, name, oh)))
                 HGOTO_ERROR(H5E_ATTR, H5E_CANTOPENOBJ, NULL, "can't open attribute")
         } /* end if */
         else {
@@ -1205,7 +1207,7 @@ H5O_attr_rename(const H5O_loc_t *loc, hid_t dxpl_id, const char *old_name,
     /* Check for attributes stored densely */
     if(H5F_addr_defined(ainfo.fheap_addr)) {
         /* Rename the attribute data in dense storage */
-        if(H5A_dense_rename(loc->file, dxpl_id, &ainfo, old_name, new_name) < 0)
+        if(H5A_dense_rename(loc->file, dxpl_id, &ainfo, old_name, new_name, oh) < 0)
             HGOTO_ERROR(H5E_ATTR, H5E_CANTUPDATE, FAIL, "error updating attribute")
     } /* end if */
     else {
@@ -1306,7 +1308,8 @@ H5O_attr_iterate_real(hid_t loc_id, const H5O_loc_t *loc, hid_t dxpl_id,
         oh = NULL;
 
         /* Iterate over attributes in dense storage */
-        if((ret_value = H5A_dense_iterate(loc->file, dxpl_id, loc_id, &ainfo, idx_type, order, skip, last_attr, attr_op, op_data)) < 0)
+        /*!FIXME use ohdr proxy -NAF */
+        if((ret_value = H5A_dense_iterate(loc->file, dxpl_id, loc_id, &ainfo, idx_type, order, skip, oh, last_attr, attr_op, op_data)) < 0)
             HERROR(H5E_ATTR, H5E_BADITER, "error iterating over attributes");
     } /* end if */
     else {
@@ -1420,7 +1423,8 @@ H5O_attr_remove_update(const H5O_loc_t *loc, H5O_t *oh, H5O_ainfo_t *ainfo,
         size_t u;                       /* Local index */
 
         /* Build the table of attributes for this object */
-        if(H5A_dense_build_table(loc->file, dxpl_id, ainfo, H5_INDEX_NAME, H5_ITER_NATIVE, &atable) < 0)
+        /*!FIXME use ohdr proxy -NAF */
+        if(H5A_dense_build_table(loc->file, dxpl_id, ainfo, H5_INDEX_NAME, H5_ITER_NATIVE, oh, &atable) < 0)
             HGOTO_ERROR(H5E_ATTR, H5E_CANTINIT, FAIL, "error building attribute table")
 
         /* Inspect attributes in table for ones that can't be converted back
@@ -1475,7 +1479,8 @@ H5O_attr_remove_update(const H5O_loc_t *loc, H5O_t *oh, H5O_ainfo_t *ainfo,
             } /* end for */
 
             /* Remove the dense storage */
-            if(H5A_dense_delete(loc->file, dxpl_id, ainfo) < 0)
+            /*!FIXME use ohdr proxy -NAF */
+            if(H5A_dense_delete(loc->file, dxpl_id, ainfo, oh) < 0)
                 HGOTO_ERROR(H5E_ATTR, H5E_CANTDELETE, FAIL, "unable to delete dense attribute storage")
         } /* end if */
     } /* end if */
@@ -1591,7 +1596,8 @@ H5O_attr_remove(const H5O_loc_t *loc, const char *name, hid_t dxpl_id)
     /* Check for attributes stored densely */
     if(H5F_addr_defined(ainfo.fheap_addr)) {
         /* Delete attribute from dense storage */
-        if(H5A_dense_remove(loc->file, dxpl_id, &ainfo, name) < 0)
+        /*!FIXME use ohdr proxy -NAF */
+        if(H5A_dense_remove(loc->file, dxpl_id, &ainfo, name, oh) < 0)
             HGOTO_ERROR(H5E_ATTR, H5E_CANTDELETE, FAIL, "unable to delete attribute in dense storage")
     } /* end if */
     else {
@@ -1675,7 +1681,8 @@ H5O_attr_remove_by_idx(const H5O_loc_t *loc, H5_index_t idx_type,
     /* Check for attributes stored densely */
     if(H5F_addr_defined(ainfo.fheap_addr)) {
         /* Delete attribute from dense storage */
-        if(H5A_dense_remove_by_idx(loc->file, dxpl_id, &ainfo, idx_type, order, n) < 0)
+        /*!FIXME use ohdr proxy -NAF */
+        if(H5A_dense_remove_by_idx(loc->file, dxpl_id, &ainfo, idx_type, order, n, oh) < 0)
             HGOTO_ERROR(H5E_ATTR, H5E_CANTDELETE, FAIL, "unable to delete attribute in dense storage")
     } /* end if */
     else {
@@ -1860,7 +1867,8 @@ H5O_attr_exists(const H5O_loc_t *loc, const char *name, hid_t dxpl_id)
     /* Check for attributes stored densely */
     if(H5F_addr_defined(ainfo.fheap_addr)) {
         /* Check if attribute exists in dense storage */
-        if((ret_value = H5A_dense_exists(loc->file, dxpl_id, &ainfo, name)) < 0)
+        /*!FIXME use ohdr proxy -NAF */
+        if((ret_value = H5A_dense_exists(loc->file, dxpl_id, &ainfo, name, oh)) < 0)
             HGOTO_ERROR(H5E_ATTR, H5E_BADITER, FAIL, "error checking for existence of attribute")
     } /* end if */
     else {
@@ -1928,8 +1936,9 @@ H5O_attr_bh_info(H5F_t *f, hid_t dxpl_id, H5O_t *oh, H5_ih_info_t *bh_info)
         else if(ainfo_exists > 0) {
             /* Check if name index available */
             if(H5F_addr_defined(ainfo.name_bt2_addr)) {
+                /*!FIXME use ohdr proxy -NAF */
                 /* Open the name index v2 B-tree */
-                if(NULL == (bt2_name = H5B2_open(f, dxpl_id, ainfo.name_bt2_addr, NULL)))
+                if(NULL == (bt2_name = H5B2_open(f, dxpl_id, ainfo.name_bt2_addr, NULL, oh)))
                     HGOTO_ERROR(H5E_ATTR, H5E_CANTOPENOBJ, FAIL, "unable to open v2 B-tree for name index")
 
                 /* Get name index B-tree size */
@@ -1939,8 +1948,9 @@ H5O_attr_bh_info(H5F_t *f, hid_t dxpl_id, H5O_t *oh, H5_ih_info_t *bh_info)
 
             /* Check if creation order index available */
             if(H5F_addr_defined(ainfo.corder_bt2_addr)) {
+                /*!FIXME use ohdr proxy -NAF */
                 /* Open the creation order index v2 B-tree */
-                if(NULL == (bt2_corder = H5B2_open(f, dxpl_id, ainfo.corder_bt2_addr, NULL)))
+                if(NULL == (bt2_corder = H5B2_open(f, dxpl_id, ainfo.corder_bt2_addr, NULL, oh)))
                     HGOTO_ERROR(H5E_ATTR, H5E_CANTOPENOBJ, FAIL, "unable to open v2 B-tree for creation order index")
 
                 /* Get creation order index B-tree size */
diff --git a/src/H5Oprivate.h b/src/H5Oprivate.h
index 36ba8a4..66744f3 100644
--- a/src/H5Oprivate.h
+++ b/src/H5Oprivate.h
@@ -437,7 +437,8 @@ typedef struct H5O_storage_chunk_earray_t {
 struct H5B2_t;                          /* Defined in H5B2pkg.h          */
 
 typedef struct H5O_storage_chunk_bt2_t {
-    struct H5B2_t *bt2;
+    haddr_t     dset_ohdr_addr;         /* File address dataset's object header */
+    struct H5B2_t *bt2;                 /* Pointer to b-tree 2 struct */
 } H5O_storage_chunk_bt2_t;
 
 typedef struct H5O_storage_chunk_t {
diff --git a/src/H5Otest.c b/src/H5Otest.c
index ca1b426..a056068 100644
--- a/src/H5Otest.c
+++ b/src/H5Otest.c
@@ -193,12 +193,13 @@ H5O_is_attr_empty_test(hid_t oid)
             if(H5F_addr_defined(ainfo.fheap_addr)) {
                 /* Check for any messages in object header */
                 HDassert(nattrs == 0);
-            
+
                 /* Set metadata tag in dxpl_id */
                 H5_BEGIN_TAG(H5AC_ind_dxpl_id, loc->addr, FAIL);
 
                 /* Open the name index v2 B-tree */
-                if(NULL == (bt2_name = H5B2_open(loc->file, H5AC_ind_dxpl_id, ainfo.name_bt2_addr, NULL)))
+                /*!FIXME use ohdr proxy -NAF */
+                if(NULL == (bt2_name = H5B2_open(loc->file, H5AC_ind_dxpl_id, ainfo.name_bt2_addr, NULL, oh)))
                     HGOTO_ERROR(H5E_OHDR, H5E_CANTOPENOBJ, FAIL, "unable to open v2 B-tree for name index")
 
                 /* Reset metadata tag in dxpl_id */
@@ -291,7 +292,8 @@ H5O_num_attrs_test(hid_t oid, hsize_t *nattrs)
             H5_BEGIN_TAG(H5AC_ind_dxpl_id, loc->addr, FAIL);
 
             /* Open the name index v2 B-tree */
-            if(NULL == (bt2_name = H5B2_open(loc->file, H5AC_ind_dxpl_id, ainfo.name_bt2_addr, NULL)))
+                /*!FIXME use ohdr proxy -NAF */
+            if(NULL == (bt2_name = H5B2_open(loc->file, H5AC_ind_dxpl_id, ainfo.name_bt2_addr, NULL, oh)))
                 HGOTO_ERROR(H5E_OHDR, H5E_CANTOPENOBJ, FAIL, "unable to open v2 B-tree for name index")
 
             /* Reset metadata tag in dxpl_id */
@@ -379,7 +381,8 @@ H5O_attr_dense_info_test(hid_t oid, hsize_t *name_count, hsize_t *corder_count)
         HGOTO_DONE(FAIL)
 
     /* Open the name index v2 B-tree */
-    if(NULL == (bt2_name = H5B2_open(loc->file, H5AC_ind_dxpl_id, ainfo.name_bt2_addr, NULL)))
+    /*!FIXME use ohdr proxy -NAF */
+    if(NULL == (bt2_name = H5B2_open(loc->file, H5AC_ind_dxpl_id, ainfo.name_bt2_addr, NULL, oh)))
         HGOTO_ERROR(H5E_OHDR, H5E_CANTOPENOBJ, FAIL, "unable to open v2 B-tree for name index")
 
     /* Retrieve # of records in name index */
@@ -389,7 +392,8 @@ H5O_attr_dense_info_test(hid_t oid, hsize_t *name_count, hsize_t *corder_count)
     /* Check if there is a creation order index */
     if(H5F_addr_defined(ainfo.corder_bt2_addr)) {
         /* Open the creation order index v2 B-tree */
-        if(NULL == (bt2_corder = H5B2_open(loc->file, H5AC_ind_dxpl_id, ainfo.corder_bt2_addr, NULL)))
+        /*!FIXME use ohdr proxy -NAF */
+        if(NULL == (bt2_corder = H5B2_open(loc->file, H5AC_ind_dxpl_id, ainfo.corder_bt2_addr, NULL, oh)))
             HGOTO_ERROR(H5E_OHDR, H5E_CANTOPENOBJ, FAIL, "unable to open v2 B-tree for creation order index")
 
         /* Retrieve # of records in creation order index */
diff --git a/src/H5SM.c b/src/H5SM.c
index 62efb50..c71d6e5 100644
--- a/src/H5SM.c
+++ b/src/H5SM.c
@@ -481,7 +481,7 @@ H5SM_create_index(H5F_t *f, H5SM_index_header_t *header, hid_t dxpl_id)
         bt2_cparam.rrec_size = (uint32_t)H5SM_SOHM_ENTRY_SIZE(f);
         bt2_cparam.split_percent = H5SM_B2_SPLIT_PERCENT;
         bt2_cparam.merge_percent = H5SM_B2_MERGE_PERCENT;
-        if(NULL == (bt2 = H5B2_create(f, dxpl_id, &bt2_cparam, f)))
+        if(NULL == (bt2 = H5B2_create(f, dxpl_id, &bt2_cparam, f, NULL)))
             HGOTO_ERROR(H5E_SOHM, H5E_CANTCREATE, FAIL, "B-tree creation failed for SOHM index")
 
         /* Retrieve the v2 B-tree's address in the file */
@@ -581,7 +581,7 @@ H5SM_delete_index(H5F_t *f, H5SM_index_header_t *header, hid_t dxpl_id,
         HDassert(header->index_type == H5SM_BTREE);
 
         /* Delete the B-tree. */
-        if(H5B2_delete(f, dxpl_id, header->index_addr, f, NULL, NULL) < 0)
+        if(H5B2_delete(f, dxpl_id, header->index_addr, f, NULL, NULL, NULL) < 0)
             HGOTO_ERROR(H5E_SOHM, H5E_CANTDELETE, FAIL, "unable to delete B-tree")
 
         /* Revert to list unless B-trees can have zero records */
@@ -724,7 +724,7 @@ H5SM_convert_list_to_btree(H5F_t *f, H5SM_index_header_t *header,
     bt2_cparam.rrec_size = (uint32_t)H5SM_SOHM_ENTRY_SIZE(f);
     bt2_cparam.split_percent = H5SM_B2_SPLIT_PERCENT;
     bt2_cparam.merge_percent = H5SM_B2_MERGE_PERCENT;
-    if(NULL == (bt2 = H5B2_create(f, dxpl_id, &bt2_cparam, f)))
+    if(NULL == (bt2 = H5B2_create(f, dxpl_id, &bt2_cparam, f, NULL)))
         HGOTO_ERROR(H5E_SOHM, H5E_CANTCREATE, FAIL, "B-tree creation failed for SOHM index")
 
     /* Retrieve the v2 B-tree's address in the file */
@@ -837,7 +837,7 @@ H5SM_convert_btree_to_list(H5F_t * f, H5SM_index_header_t * header, hid_t dxpl_i
     /* Delete the B-tree and have messages copy themselves to the
      * list as they're deleted
      */
-    if(H5B2_delete(f, dxpl_id, btree_addr, f, H5SM_bt2_convert_to_list_op, list) < 0)
+    if(H5B2_delete(f, dxpl_id, btree_addr, f, NULL, H5SM_bt2_convert_to_list_op, list) < 0)
         HGOTO_ERROR(H5E_SOHM, H5E_CANTDELETE, FAIL, "unable to delete B-tree")
 
 done:
@@ -1320,7 +1320,7 @@ H5SM_write_mesg(H5F_t *f, hid_t dxpl_id, H5O_t *open_oh,
         HDassert(header->index_type == H5SM_BTREE);
 
         /* Open the index v2 B-tree */
-        if(NULL == (bt2 = H5B2_open(f, dxpl_id, header->index_addr, f)))
+        if(NULL == (bt2 = H5B2_open(f, dxpl_id, header->index_addr, f, NULL)))
             HGOTO_ERROR(H5E_SOHM, H5E_CANTOPENOBJ, FAIL, "unable to open v2 B-tree for SOHM index")
 
         if(defer) {
@@ -1448,7 +1448,7 @@ H5SM_write_mesg(H5F_t *f, hid_t dxpl_id, H5O_t *open_oh,
 
                 /* Open the index v2 B-tree, if it isn't already */
                 if(NULL == bt2) {
-                    if(NULL == (bt2 = H5B2_open(f, dxpl_id, header->index_addr, f)))
+                    if(NULL == (bt2 = H5B2_open(f, dxpl_id, header->index_addr, f, NULL)))
                         HGOTO_ERROR(H5E_SOHM, H5E_CANTOPENOBJ, FAIL, "unable to open v2 B-tree for SOHM index")
                 } /* end if */
 
@@ -1817,7 +1817,7 @@ H5SM_delete_from_index(H5F_t *f, hid_t dxpl_id, H5O_t *open_oh,
         HDassert(header->index_type == H5SM_BTREE);
 
         /* Open the index v2 B-tree */
-        if(NULL == (bt2 = H5B2_open(f, dxpl_id, header->index_addr, f)))
+        if(NULL == (bt2 = H5B2_open(f, dxpl_id, header->index_addr, f, NULL)))
             HGOTO_ERROR(H5E_SOHM, H5E_CANTOPENOBJ, FAIL, "unable to open v2 B-tree for SOHM index")
 
         /* If this returns failure, it means that the message wasn't found.
@@ -1847,7 +1847,7 @@ H5SM_delete_from_index(H5F_t *f, hid_t dxpl_id, H5O_t *open_oh,
         else {
             /* Open the index v2 B-tree, if it isn't already */
             if(NULL == bt2) {
-                if(NULL == (bt2 = H5B2_open(f, dxpl_id, header->index_addr, f)))
+                if(NULL == (bt2 = H5B2_open(f, dxpl_id, header->index_addr, f, NULL)))
                     HGOTO_ERROR(H5E_SOHM, H5E_CANTOPENOBJ, FAIL, "unable to open v2 B-tree for SOHM index")
             } /* end if */
 
@@ -2189,7 +2189,7 @@ H5SM_get_refcount(H5F_t *f, hid_t dxpl_id, unsigned type_id,
         HDassert(header->index_type == H5SM_BTREE);
 
         /* Open the index v2 B-tree */
-        if(NULL == (bt2 = H5B2_open(f, dxpl_id, header->index_addr, f)))
+        if(NULL == (bt2 = H5B2_open(f, dxpl_id, header->index_addr, f, NULL)))
             HGOTO_ERROR(H5E_SOHM, H5E_CANTOPENOBJ, FAIL, "unable to open v2 B-tree for SOHM index")
 
         /* Look up the message in the v2 B-tree */
@@ -2705,7 +2705,7 @@ H5SM_ih_size(H5F_t *f, hid_t dxpl_id, hsize_t *hdr_size, H5_ih_info_t *ih_info)
 	if(table->indexes[u].index_type == H5SM_BTREE) {
 	    if(H5F_addr_defined(table->indexes[u].index_addr)) {
                 /* Open the index v2 B-tree */
-                if(NULL == (bt2 = H5B2_open(f, dxpl_id, table->indexes[u].index_addr, f)))
+                if(NULL == (bt2 = H5B2_open(f, dxpl_id, table->indexes[u].index_addr, f, NULL)))
                     HGOTO_ERROR(H5E_SOHM, H5E_CANTOPENOBJ, FAIL, "unable to open v2 B-tree for SOHM index")
 
 		if(H5B2_size(bt2, dxpl_id, &(ih_info->index_size)) < 0)
diff --git a/src/H5SMbtree2.c b/src/H5SMbtree2.c
index daa1e4f..62b45f0 100644
--- a/src/H5SMbtree2.c
+++ b/src/H5SMbtree2.c
@@ -67,6 +67,8 @@ const H5B2_class_t H5SM_INDEX[1]={{   /* B-tree class information */
     H5SM_message_compare,             /* Record comparison callback */
     H5SM_message_encode,              /* Record encoding callback */
     H5SM_message_decode,              /* Record decoding callback */
+    NULL,                             /* Create flush dependency */
+    NULL,                             /* Update flush dependency */
     H5SM_bt2_debug,                   /* Record debugging callback */
     H5SM_bt2_crt_dbg_context,	      /* Create debugging context */
     H5SM_bt2_dst_context 	      /* Destroy debugging context */