Bring over another batch (hopefully the last) of non-SWMR "normalization"

changes from the revise_chunks branch.

17 files changed, 550 insertions, 369 deletions

diff --git a/src/H5B2.c b/src/H5B2.c
index bce6a9f..af5fae7 100644
--- a/src/H5B2.c
+++ b/src/H5B2.c
@@ -343,11 +343,11 @@ H5B2_update(H5B2_t *bt2, hid_t dxpl_id, void *udata, H5B2_modify_t op, void *op_
     /* Attempt to insert record into B-tree */
     if(hdr->depth > 0) {
         if(H5B2__update_internal(hdr, dxpl_id, hdr->depth, NULL, &hdr->root, &status, H5B2_POS_ROOT, udata, op, op_data) < 0)
-            HGOTO_ERROR(H5E_BTREE, H5E_CANTINSERT, FAIL, "unable to update record in B-tree internal node")
+            HGOTO_ERROR(H5E_BTREE, H5E_CANTUPDATE, FAIL, "unable to update record in B-tree internal node")
     } /* end if */
     else {
         if(H5B2__update_leaf(hdr, dxpl_id, &hdr->root, &status, H5B2_POS_ROOT, udata, op, op_data) < 0)
-            HGOTO_ERROR(H5E_BTREE, H5E_CANTINSERT, FAIL, "unable to update record in B-tree leaf node")
+            HGOTO_ERROR(H5E_BTREE, H5E_CANTUPDATE, FAIL, "unable to update record in B-tree leaf node")
     } /* end else */
 
     /* Sanity check */
diff --git a/src/H5B2int.c b/src/H5B2int.c
index 3bd788c..a8fa59f 100644
--- a/src/H5B2int.c
+++ b/src/H5B2int.c
@@ -1925,7 +1925,7 @@ H5B2__update_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")
 
-        /* Mark the node as dirty if it changed */
+        /* Mark the node as dirty */
         leaf_flags |= H5AC__DIRTIED_FLAG;
 
         /* Indicate that the record was inserted */
diff --git a/src/H5B2pkg.h b/src/H5B2pkg.h
index edac296..6a385d4 100644
--- a/src/H5B2pkg.h
+++ b/src/H5B2pkg.h
@@ -261,8 +261,8 @@ typedef struct H5B2_leaf_cache_ud_t {
 #ifdef H5B2_TESTING
 /* Node information for testing */
 typedef struct H5B2_node_info_test_t {
-    unsigned depth;             /* Depth of node */
-    unsigned nrec;              /* Number of records in node */
+    uint16_t depth;             /* Depth of node */
+    uint16_t nrec;              /* Number of records in node */
 } H5B2_node_info_test_t;
 #endif /* H5B2_TESTING */
 
diff --git a/src/H5Dchunk.c b/src/H5Dchunk.c
index dde83fe..7637339 100644
--- a/src/H5Dchunk.c
+++ b/src/H5Dchunk.c
@@ -4851,7 +4851,6 @@ H5D__chunk_prune_by_extent(H5D_t *dset, hid_t dxpl_id, const hsize_t *old_dim)
      * will never change. */
     chk_store.chunk.scaled = scaled;
     H5D_BUILD_IO_INFO_RD(&chk_io_info, dset, dxpl_cache, dxpl_id, H5AC_rawdata_dxpl_id, &chk_store, NULL);
-    chk_io_info.raw_dxpl_id = H5AC_rawdata_dxpl_id;
 
     /* Compose chunked index info struct */
     idx_info.f = dset->oloc.file;
diff --git a/src/H5EA.c b/src/H5EA.c
index 8a4c5a1..9c3f3e7 100644
--- a/src/H5EA.c
+++ b/src/H5EA.c
@@ -78,6 +78,8 @@ static herr_t
 H5EA__lookup_elmt(const H5EA_t *ea, hid_t dxpl_id, hsize_t idx, hbool_t will_extend,
     unsigned thing_acc, void **thing, uint8_t **thing_elmt_buf,
     hsize_t *thing_elmt_idx, H5EA__unprotect_func_t *thing_unprot_func);
+static H5EA_t *H5EA__new(H5F_t *f, hid_t dxpl_id, haddr_t ea_addr,
+    hbool_t from_open, void *ctx_udata);
 
 
 /*********************/
@@ -116,49 +118,45 @@ H5FL_BLK_DEFINE(ea_native_elmt);
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5EA_create
+ * Function:	H5EA__new
  *
- * Purpose:	Creates a new empty extensible array in the file.
+ * Purpose:	Allocate and initialize a new extensible array wrapper in memory
  *
- * Return:	Pointer to earray wrapper on success
+ * Return:	Pointer to earray wrapper success
  *              NULL on failure
  *
  * Programmer:	Quincey Koziol
- *		koziol@hdfgroup.org
- *		Jun 17 2008
+ *		koziol@lbl.gov
+ *		Oct 10 2016
  *
  *-------------------------------------------------------------------------
  */
-BEGIN_FUNC(PRIV, ERR,
+BEGIN_FUNC(STATIC, ERR,
 H5EA_t *, NULL, NULL,
-H5EA_create(H5F_t *f, hid_t dxpl_id, const H5EA_create_t *cparam, void *ctx_udata))
+H5EA__new(H5F_t *f, hid_t dxpl_id, haddr_t ea_addr, hbool_t from_open, void *ctx_udata))
 
     /* Local variables */
     H5EA_t *ea = NULL;          /* Pointer to new extensible array */
     H5EA_hdr_t *hdr = NULL;     /* The extensible array header information */
-    haddr_t ea_addr;            /* Array header address */
 
     /*
      * Check arguments.
      */
     HDassert(f);
-    HDassert(cparam);
-
-    /* H5EA interface sanity check */
-    HDcompile_assert(H5EA_NUM_CLS_ID == NELMTS(H5EA_client_class_g));
-
-    /* Create extensible array header */
-    if(HADDR_UNDEF == (ea_addr = H5EA__hdr_create(f, dxpl_id, cparam, ctx_udata)))
-	H5E_THROW(H5E_CANTINIT, "can't create extensible array header")
+    HDassert(H5F_addr_defined(ea_addr));
 
     /* Allocate extensible array wrapper */
-    if(NULL == (ea = H5FL_MALLOC(H5EA_t)))
+    if(NULL == (ea = H5FL_CALLOC(H5EA_t)))
 	H5E_THROW(H5E_CANTALLOC, "memory allocation failed for extensible array info")
 
     /* Lock the array header into memory */
-    if(NULL == (hdr = H5EA__hdr_protect(f, dxpl_id, ea_addr, ctx_udata, H5AC__NO_FLAGS_SET)))
+    if(NULL == (hdr = H5EA__hdr_protect(f, dxpl_id, ea_addr, ctx_udata, H5AC__READ_ONLY_FLAG)))
 	H5E_THROW(H5E_CANTPROTECT, "unable to load extensible array header")
 
+    /* Check for pending array deletion */
+    if(from_open && hdr->pending_delete)
+        H5E_THROW(H5E_CANTOPENOBJ, "can't open extensible array pending deletion")
+
     /* Point extensible array wrapper at header and bump it's ref count */
     ea->hdr = hdr;
     if(H5EA__hdr_incr(ea->hdr) < 0)
@@ -182,6 +180,57 @@ CATCH
         if(ea && H5EA_close(ea, dxpl_id) < 0)
             H5E_THROW(H5E_CLOSEERROR, "unable to close extensible array")
 
+END_FUNC(STATIC)  /* end H5EA__new() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5EA_create
+ *
+ * Purpose:	Creates a new empty extensible array in the file.
+ *
+ * Return:	Pointer to earray wrapper on success
+ *              NULL on failure
+ *
+ * Programmer:	Quincey Koziol
+ *		koziol@hdfgroup.org
+ *		Jun 17 2008
+ *
+ *-------------------------------------------------------------------------
+ */
+BEGIN_FUNC(PRIV, ERR,
+H5EA_t *, NULL, NULL,
+H5EA_create(H5F_t *f, hid_t dxpl_id, const H5EA_create_t *cparam, void *ctx_udata))
+
+    /* Local variables */
+    H5EA_t *ea = NULL;          /* Pointer to new extensible array */
+    haddr_t ea_addr;            /* Array header address */
+
+    /*
+     * Check arguments.
+     */
+    HDassert(f);
+    HDassert(cparam);
+
+    /* H5EA interface sanity check */
+    HDcompile_assert(H5EA_NUM_CLS_ID == NELMTS(H5EA_client_class_g));
+
+    /* Create extensible array header */
+    if(HADDR_UNDEF == (ea_addr = H5EA__hdr_create(f, dxpl_id, cparam, ctx_udata)))
+	H5E_THROW(H5E_CANTINIT, "can't create extensible array header")
+
+    /* Allocate and initialize new extensible array wrapper */
+    if(NULL == (ea = H5EA__new(f, dxpl_id, ea_addr, FALSE, ctx_udata)))
+	H5E_THROW(H5E_CANTINIT, "allocation and/or initialization failed for extensible array wrapper")
+
+    /* Set the return value */
+    ret_value = ea;
+
+CATCH
+
+    if(!ret_value)
+        if(ea && H5EA_close(ea, dxpl_id) < 0)
+            H5E_THROW(H5E_CLOSEERROR, "unable to close extensible array")
+
 END_FUNC(PRIV)  /* end H5EA_create() */
 
 
@@ -205,7 +254,6 @@ H5EA_open(H5F_t *f, hid_t dxpl_id, haddr_t ea_addr, void *ctx_udata))
 
     /* Local variables */
     H5EA_t *ea = NULL;          /* Pointer to new extensible array wrapper */
-    H5EA_hdr_t *hdr = NULL;     /* The extensible array header information */
 
     /*
      * Check arguments.
@@ -213,37 +261,15 @@ H5EA_open(H5F_t *f, hid_t dxpl_id, haddr_t ea_addr, void *ctx_udata))
     HDassert(f);
     HDassert(H5F_addr_defined(ea_addr));
 
-    /* Load the array header into memory */
-    if(NULL == (hdr = H5EA__hdr_protect(f, dxpl_id, ea_addr, ctx_udata, H5AC__READ_ONLY_FLAG)))
-        H5E_THROW(H5E_CANTPROTECT, "unable to load extensible array header, address = %llu", (unsigned long long)ea_addr)
-
-    /* Check for pending array deletion */
-    if(hdr->pending_delete)
-        H5E_THROW(H5E_CANTOPENOBJ, "can't open extensible array pending deletion")
-
-    /* Create fractal heap info */
-    if(NULL == (ea = H5FL_MALLOC(H5EA_t)))
-        H5E_THROW(H5E_CANTALLOC, "memory allocation failed for extensible array info")
-
-    /* Point extensible array wrapper at header */
-    ea->hdr = hdr;
-    if(H5EA__hdr_incr(ea->hdr) < 0)
-        H5E_THROW(H5E_CANTINC, "can't increment reference count on shared array header")
-
-    /* Increment # of files using this array header */
-    if(H5EA__hdr_fuse_incr(ea->hdr) < 0)
-        H5E_THROW(H5E_CANTINC, "can't increment file reference count on shared array header")
-
-    /* Set file pointer for this array open context */
-    ea->f = f;
+    /* Allocate and initialize new extensible array wrapper */
+    if(NULL == (ea = H5EA__new(f, dxpl_id, ea_addr, TRUE, ctx_udata)))
+	H5E_THROW(H5E_CANTINIT, "allocation and/or initialization failed for extensible array wrapper")
 
     /* Set the return value */
     ret_value = ea;
 
 CATCH
 
-    if(hdr && H5EA__hdr_unprotect(hdr, dxpl_id, H5AC__NO_FLAGS_SET) < 0)
-        H5E_THROW(H5E_CANTUNPROTECT, "unable to release extensible array header")
     if(!ret_value)
         if(ea && H5EA_close(ea, dxpl_id) < 0)
             H5E_THROW(H5E_CLOSEERROR, "unable to close extensible array")
@@ -818,26 +844,28 @@ H5EA_close(H5EA_t *ea, hid_t dxpl_id))
      */
     HDassert(ea);
 
-    /* Decrement file reference & check if this is the last open extensible array using the shared array header */
-    if(0 == H5EA__hdr_fuse_decr(ea->hdr)) {
-        /* Set the shared array header's file context for this operation */
-        ea->hdr->f = ea->f;
-
-        /* Shut down anything that can't be put in the header's 'flush' callback */
-
-        /* Check for pending array deletion */
-        if(ea->hdr->pending_delete) {
-            /* Set local info, so array deletion can occur after decrementing the
-             *  header's ref count
-             */
-            pending_delete = TRUE;
-            ea_addr = ea->hdr->addr;
+    /* Close the header, if it was set */
+    if(ea->hdr) {
+        /* Decrement file reference & check if this is the last open extensible array using the shared array header */
+        if(0 == H5EA__hdr_fuse_decr(ea->hdr)) {
+            /* Set the shared array header's file context for this operation */
+            ea->hdr->f = ea->f;
+
+            /* Shut down anything that can't be put in the header's 'flush' callback */
+
+            /* Check for pending array deletion */
+            if(ea->hdr->pending_delete) {
+                /* Set local info, so array deletion can occur after decrementing the
+                 *  header's ref count
+                 */
+                pending_delete = TRUE;
+                ea_addr = ea->hdr->addr;
+            } /* end if */
         } /* end if */
-    } /* end if */
 
-    /* Check for pending array deletion */
-    if(pending_delete) {
-        H5EA_hdr_t *hdr;            /* Another pointer to extensible array header */
+        /* Check for pending array deletion */
+        if(pending_delete) {
+            H5EA_hdr_t *hdr;            /* Another pointer to extensible array header */
 
 #ifndef NDEBUG
 {
@@ -854,33 +882,34 @@ H5EA_close(H5EA_t *ea, hid_t dxpl_id))
 }
 #endif /* NDEBUG */
 
-        /* Lock the array header into memory */
-        /* (OK to pass in NULL for callback context, since we know the header must be in the cache) */
-        if(NULL == (hdr = H5EA__hdr_protect(ea->f, dxpl_id, ea_addr, NULL, H5AC__NO_FLAGS_SET)))
-            H5E_THROW(H5E_CANTLOAD, "unable to load extensible array header")
+            /* Lock the array header into memory */
+            /* (OK to pass in NULL for callback context, since we know the header must be in the cache) */
+            if(NULL == (hdr = H5EA__hdr_protect(ea->f, dxpl_id, ea_addr, NULL, H5AC__NO_FLAGS_SET)))
+                H5E_THROW(H5E_CANTLOAD, "unable to load extensible array header")
 
-        /* Set the shared array header's file context for this operation */
-        hdr->f = ea->f;
+            /* Set the shared array header's file context for this operation */
+            hdr->f = ea->f;
 
-        /* Decrement the reference count on the array header */
-        /* (don't put in H5EA_hdr_fuse_decr() as the array header may be evicted
-         *  immediately -QAK)
-         */
-        if(H5EA__hdr_decr(ea->hdr) < 0)
-            H5E_THROW(H5E_CANTDEC, "can't decrement reference count on shared array header")
+            /* Decrement the reference count on the array header */
+            /* (don't put in H5EA_hdr_fuse_decr() as the array header may be evicted
+             *  immediately -QAK)
+             */
+            if(H5EA__hdr_decr(ea->hdr) < 0)
+                H5E_THROW(H5E_CANTDEC, "can't decrement reference count on shared array header")
 
-        /* Delete array, starting with header (unprotects header) */
-        if(H5EA__hdr_delete(hdr, dxpl_id) < 0)
-            H5E_THROW(H5E_CANTDELETE, "unable to delete extensible array")
+            /* Delete array, starting with header (unprotects header) */
+            if(H5EA__hdr_delete(hdr, dxpl_id) < 0)
+                H5E_THROW(H5E_CANTDELETE, "unable to delete extensible array")
+        } /* end if */
+        else {
+            /* Decrement the reference count on the array header */
+            /* (don't put in H5EA_hdr_fuse_decr() as the array header may be evicted
+             *  immediately -QAK)
+             */
+            if(H5EA__hdr_decr(ea->hdr) < 0)
+                H5E_THROW(H5E_CANTDEC, "can't decrement reference count on shared array header")
+        } /* end else */
     } /* end if */
-    else {
-        /* Decrement the reference count on the array header */
-        /* (don't put in H5EA_hdr_fuse_decr() as the array header may be evicted
-         *  immediately -QAK)
-         */
-        if(H5EA__hdr_decr(ea->hdr) < 0)
-            H5E_THROW(H5E_CANTDEC, "can't decrement reference count on shared array header")
-    } /* end else */
 
     /* Release the extensible array wrapper */
     ea = (H5EA_t *)H5FL_FREE(H5EA_t, ea);
diff --git a/src/H5EAcache.c b/src/H5EAcache.c
index 4210b07..b7846e9 100644
--- a/src/H5EAcache.c
+++ b/src/H5EAcache.c
@@ -893,7 +893,11 @@ H5EA__cache_iblock_notify(H5AC_notify_action_t action, void *_thing))
             break;
 
         default:
+#ifdef NDEBUG
             H5E_THROW(H5E_BADVALUE, "unknown action from metadata cache")
+#else /* NDEBUG */
+            HDassert(0 && "Unknown action?!?");
+#endif /* NDEBUG */
     } /* end switch */
 
 CATCH
@@ -955,7 +959,6 @@ H5EA__cache_sblock_get_initial_load_size(void *_udata, size_t *image_len))
     /* Check arguments */
     HDassert(udata);
     HDassert(udata->hdr);
-    HDassert(udata->parent);
     HDassert(udata->sblk_idx > 0);
     HDassert(H5F_addr_defined(udata->sblk_addr));
     HDassert(image_len);
@@ -1293,7 +1296,11 @@ H5EA__cache_sblock_notify(H5AC_notify_action_t action, void *_thing))
             break;
 
         default:
+#ifdef NDEBUG
             H5E_THROW(H5E_BADVALUE, "unknown action from metadata cache")
+#else /* NDEBUG */
+            HDassert(0 && "Unknown action?!?");
+#endif /* NDEBUG */
     } /* end switch */
 
 CATCH
@@ -1355,7 +1362,6 @@ H5EA__cache_dblock_get_initial_load_size(void *_udata, size_t *image_len))
     /* Check arguments */
     HDassert(udata);
     HDassert(udata->hdr);
-    HDassert(udata->parent);
     HDassert(udata->nelmts > 0);
     HDassert(image_len);
 
@@ -1694,7 +1700,11 @@ H5EA__cache_dblock_notify(H5AC_notify_action_t action, void *_thing))
             break;
 
         default:
+#ifdef NDEBUG
             H5E_THROW(H5E_BADVALUE, "unknown action from metadata cache")
+#else /* NDEBUG */
+            HDassert(0 && "Unknown action?!?");
+#endif /* NDEBUG */
     } /* end switch */
 
 CATCH
@@ -1802,7 +1812,6 @@ H5EA__cache_dblk_page_get_initial_load_size(void *_udata, size_t *image_len))
     /* Check arguments */
     HDassert(udata);
     HDassert(udata->hdr);
-    HDassert(udata->parent);
     HDassert(image_len);
 
     /* Set the image length size */
@@ -2063,7 +2072,11 @@ H5EA__cache_dblk_page_notify(H5AC_notify_action_t action, void *_thing))
             break;
 
         default:
+#ifdef NDEBUG
             H5E_THROW(H5E_BADVALUE, "unknown action from metadata cache")
+#else /* NDEBUG */
+            HDassert(0 && "Unknown action?!?");
+#endif /* NDEBUG */
     } /* end switch */
 
 CATCH
diff --git a/src/H5F.c b/src/H5F.c
index c70f813..d2d002a 100644
--- a/src/H5F.c
+++ b/src/H5F.c
@@ -1367,6 +1367,103 @@ done:
 
 
 /*-------------------------------------------------------------------------
+ * Function:    H5Fget_metadata_read_retry_info
+ *
+ * Purpose:     To retrieve the collection of read retries for metadata items with checksum.
+ *
+ * Return:      Success:        non-negative on success
+ *              Failure:        Negative
+ *
+ * Programmer:  Vailin Choi; October 2013
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5Fget_metadata_read_retry_info(hid_t file_id, H5F_retry_info_t *info)
+{
+    H5F_t    	*file;           	/* File object for file ID */
+    unsigned 	i, j;			/* Local index variable */
+    size_t	tot_size;		/* Size of each retries[i] */
+    herr_t   	ret_value = SUCCEED;   	/* Return value */
+
+    FUNC_ENTER_API(FAIL)
+    H5TRACE2("e", "i*x", file_id, info);
+
+    /* Check args */
+    if(!info)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no info struct")
+
+    /* Get the file pointer */
+    if(NULL == (file = (H5F_t *)H5I_object_verify(file_id, H5I_FILE)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "not a file ID")
+
+    /* Copy the # of bins for "retries" array */
+    info->nbins = file->shared->retries_nbins;
+
+    /* Initialize the array of "retries" */
+    HDmemset(info->retries, 0, sizeof(info->retries));
+
+    /* Return if there are no bins -- no retries */
+    if(!info->nbins) 
+	HGOTO_DONE(SUCCEED);
+
+    /* Calculate size for each retries[i] */
+    tot_size = info->nbins * sizeof(uint32_t);
+
+    /* Map and copy information to info's retries for metadata items with tracking for read retries */
+    j = 0;
+    for(i = 0; i < H5AC_NTYPES; i++) {
+        switch(i) {
+            case H5AC_OHDR_ID:
+            case H5AC_OHDR_CHK_ID:
+            case H5AC_BT2_HDR_ID:
+            case H5AC_BT2_INT_ID:
+            case H5AC_BT2_LEAF_ID:
+            case H5AC_FHEAP_HDR_ID:
+            case H5AC_FHEAP_DBLOCK_ID:
+            case H5AC_FHEAP_IBLOCK_ID:
+            case H5AC_FSPACE_HDR_ID:
+            case H5AC_FSPACE_SINFO_ID:
+            case H5AC_SOHM_TABLE_ID:
+            case H5AC_SOHM_LIST_ID:
+            case H5AC_EARRAY_HDR_ID:
+            case H5AC_EARRAY_IBLOCK_ID:
+            case H5AC_EARRAY_SBLOCK_ID:
+            case H5AC_EARRAY_DBLOCK_ID:
+            case H5AC_EARRAY_DBLK_PAGE_ID:
+            case H5AC_FARRAY_HDR_ID:
+            case H5AC_FARRAY_DBLOCK_ID:
+            case H5AC_FARRAY_DBLK_PAGE_ID:
+            case H5AC_SUPERBLOCK_ID:
+                HDassert(j < H5F_NUM_METADATA_READ_RETRY_TYPES);
+                if(file->shared->retries[i] != NULL) {
+                    /* Allocate memory for retries[i]
+                     *
+                     * This memory should be released by the user with
+                     * the H5free_memory() call.
+                     */
+                    if(NULL == (info->retries[j] = (uint32_t *)H5MM_malloc(tot_size)))
+                        HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed")
+
+                    /* Copy the information */
+                    HDmemcpy(info->retries[j], file->shared->retries[i], tot_size);
+                } /* end if */
+
+                /* Increment location in info->retries[] array */
+                j++;
+                break;
+
+            default:
+                break;
+        } /* end switch */
+    } /* end for */
+
+done:
+    FUNC_LEAVE_API(ret_value)
+} /* end H5Fget_metadata_read_retry_info() */
+
+
+/*-------------------------------------------------------------------------
  * Function:    H5Fget_free_sections
  *
  * Purpose:     To get free-space section information for free-space manager with
diff --git a/src/H5FA.c b/src/H5FA.c
index 4435af0..c6c2e1b 100644
--- a/src/H5FA.c
+++ b/src/H5FA.c
@@ -64,6 +64,8 @@
 /********************/
 /* Local Prototypes */
 /********************/
+static H5FA_t *H5FA__new(H5F_t *f, hid_t dxpl_id, haddr_t fa_addr,
+    hbool_t from_open, void *ctx_udata);
 
 
 /*********************/
@@ -103,51 +105,44 @@ H5FL_BLK_DEFINE(fa_native_elmt);
 
 
 /*-------------------------------------------------------------------------
- * Function:    H5FA_create
+ * Function:	H5FA__new
  *
- * Purpose:     Creates a new fixed array (header) in the file.
+ * Purpose:	Allocate and initialize a new fixe array wrapper in memory
  *
- * Return:      Pointer to fixed array wrapper on success
+ * Return:	Pointer to farray wrapper success
  *              NULL on failure
  *
- * Programmer:  Vailin Choi
- *              Thursday, April 30, 2009
+ * Programmer:	Quincey Koziol
+ *		koziol@lbl.gov
+ *		Oct 17 2016
  *
  *-------------------------------------------------------------------------
  */
-BEGIN_FUNC(PRIV, ERR,
+BEGIN_FUNC(STATIC, ERR,
 H5FA_t *, NULL, NULL,
-H5FA_create(H5F_t *f, hid_t dxpl_id, const H5FA_create_t *cparam, void *ctx_udata))
+H5FA__new(H5F_t *f, hid_t dxpl_id, haddr_t fa_addr, hbool_t from_open, void *ctx_udata))
 
     /* Local variables */
     H5FA_t *fa = NULL;          /* Pointer to new fixed array */
     H5FA_hdr_t *hdr = NULL;     /* The fixed array header information */
-    haddr_t fa_addr;            /* Fixed Array header address */
-
-#ifdef H5FA_DEBUG
-HDfprintf(stderr, "%s: Called\n", FUNC);
-#endif /* H5FA_DEBUG */
 
     /*
      * Check arguments.
      */
     HDassert(f);
-    HDassert(cparam);
-
-    /* H5FA interface sanity check */
-    HDcompile_assert(H5FA_NUM_CLS_ID == NELMTS(H5FA_client_class_g));
-
-    /* Create fixed array header */
-    if(HADDR_UNDEF == (fa_addr = H5FA__hdr_create(f, dxpl_id, cparam, ctx_udata)))
-        H5E_THROW(H5E_CANTINIT, "can't create fixed array header")
+    HDassert(H5F_addr_defined(fa_addr));
 
     /* Allocate fixed array wrapper */
-    if(NULL == (fa = H5FL_MALLOC(H5FA_t)))
-        H5E_THROW(H5E_CANTALLOC, "memory allocation failed for fixed array info")
+    if(NULL == (fa = H5FL_CALLOC(H5FA_t)))
+	H5E_THROW(H5E_CANTALLOC, "memory allocation failed for fixed array info")
 
     /* Lock the array header into memory */
-    if(NULL == (hdr = H5FA__hdr_protect(f, dxpl_id, fa_addr, ctx_udata, H5AC__NO_FLAGS_SET)))
-        H5E_THROW(H5E_CANTPROTECT, "unable to load fixed array header")
+    if(NULL == (hdr = H5FA__hdr_protect(f, dxpl_id, fa_addr, ctx_udata, H5AC__READ_ONLY_FLAG)))
+	H5E_THROW(H5E_CANTPROTECT, "unable to load fixed array header")
+
+    /* Check for pending array deletion */
+    if(from_open && hdr->pending_delete)
+        H5E_THROW(H5E_CANTOPENOBJ, "can't open fixed array pending deletion")
 
     /* Point fixed array wrapper at header and bump it's ref count */
     fa->hdr = hdr;
@@ -172,6 +167,56 @@ CATCH
         if(fa && H5FA_close(fa, dxpl_id) < 0)
             H5E_THROW(H5E_CLOSEERROR, "unable to close fixed array")
 
+END_FUNC(STATIC)  /* end H5FA__new() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5FA_create
+ *
+ * Purpose:     Creates a new fixed array (header) in the file.
+ *
+ * Return:      Pointer to fixed array wrapper on success
+ *              NULL on failure
+ *
+ * Programmer:  Vailin Choi
+ *              Thursday, April 30, 2009
+ *
+ *-------------------------------------------------------------------------
+ */
+BEGIN_FUNC(PRIV, ERR,
+H5FA_t *, NULL, NULL,
+H5FA_create(H5F_t *f, hid_t dxpl_id, const H5FA_create_t *cparam, void *ctx_udata))
+
+    /* Local variables */
+    H5FA_t *fa = NULL;          /* Pointer to new fixed array */
+    haddr_t fa_addr;            /* Fixed array header address */
+
+    /*
+     * Check arguments.
+     */
+    HDassert(f);
+    HDassert(cparam);
+
+    /* H5FA interface sanity check */
+    HDcompile_assert(H5FA_NUM_CLS_ID == NELMTS(H5FA_client_class_g));
+
+    /* Create fixed array header */
+    if(HADDR_UNDEF == (fa_addr = H5FA__hdr_create(f, dxpl_id, cparam, ctx_udata)))
+        H5E_THROW(H5E_CANTINIT, "can't create fixed array header")
+
+    /* Allocate and initialize new fixed array wrapper */
+    if(NULL == (fa = H5FA__new(f, dxpl_id, fa_addr, FALSE, ctx_udata)))
+	H5E_THROW(H5E_CANTINIT, "allocation and/or initialization failed for fixed array wrapper")
+
+    /* Set the return value */
+    ret_value = fa;
+
+CATCH
+
+    if(!ret_value)
+        if(fa && H5FA_close(fa, dxpl_id) < 0)
+            H5E_THROW(H5E_CLOSEERROR, "unable to close fixed array")
+
 END_FUNC(PRIV)  /* end H5FA_create() */
 
 
@@ -194,7 +239,6 @@ H5FA_open(H5F_t *f, hid_t dxpl_id, haddr_t fa_addr, void *ctx_udata))
 
     /* Local variables */
     H5FA_t *fa = NULL;          /* Pointer to new fixed array wrapper */
-    H5FA_hdr_t *hdr = NULL;     /* The fixed array header information */
 
     /*
      * Check arguments.
@@ -202,40 +246,15 @@ H5FA_open(H5F_t *f, hid_t dxpl_id, haddr_t fa_addr, void *ctx_udata))
     HDassert(f);
     HDassert(H5F_addr_defined(fa_addr));
 
-    /* Load the array header into memory */
-#ifdef H5FA_DEBUG
-HDfprintf(stderr, "%s: fa_addr = %a\n", FUNC, fa_addr);
-#endif /* H5FA_DEBUG */
-    if(NULL == (hdr = H5FA__hdr_protect(f, dxpl_id, fa_addr, ctx_udata, H5AC__READ_ONLY_FLAG)))
-        H5E_THROW(H5E_CANTPROTECT, "unable to load fixed array header, address = %llu", (unsigned long long)fa_addr)
-
-    /* Check for pending array deletion */
-    if(hdr->pending_delete)
-        H5E_THROW(H5E_CANTOPENOBJ, "can't open fixed array pending deletion")
-
-    /* Create fixed array info */
-    if(NULL == (fa = H5FL_MALLOC(H5FA_t)))
-        H5E_THROW(H5E_CANTALLOC, "memory allocation failed for fixed array info")
-
-    /* Point fixed array wrapper at header */
-    fa->hdr = hdr;
-    if(H5FA__hdr_incr(fa->hdr) < 0)
-        H5E_THROW(H5E_CANTINC, "can't increment reference count on shared array header")
-
-    /* Increment # of files using this array header */
-    if(H5FA__hdr_fuse_incr(fa->hdr) < 0)
-        H5E_THROW(H5E_CANTINC, "can't increment file reference count on shared array header")
-
-    /* Set file pointer for this array open context */
-    fa->f = f;
+    /* Allocate and initialize new fixed array wrapper */
+    if(NULL == (fa = H5FA__new(f, dxpl_id, fa_addr, TRUE, ctx_udata)))
+	H5E_THROW(H5E_CANTINIT, "allocation and/or initialization failed for fixed array wrapper")
 
     /* Set the return value */
     ret_value = fa;
 
 CATCH
 
-    if(hdr && H5FA__hdr_unprotect(hdr, dxpl_id, H5AC__NO_FLAGS_SET) < 0)
-        H5E_THROW(H5E_CANTUNPROTECT, "unable to release fixed array header")
     if(!ret_value)
         if(fa && H5FA_close(fa, dxpl_id) < 0)
             H5E_THROW(H5E_CLOSEERROR, "unable to close fixed array")
@@ -534,26 +553,28 @@ H5FA_close(H5FA_t *fa, hid_t dxpl_id))
      */
     HDassert(fa);
 
-    /* Decrement file reference & check if this is the last open fixed array using the shared array header */
-    if(0 == H5FA__hdr_fuse_decr(fa->hdr)) {
-        /* Set the shared array header's file context for this operation */
-        fa->hdr->f = fa->f;
-
-        /* Shut down anything that can't be put in the header's 'flush' callback */
-
-        /* Check for pending array deletion */
-        if(fa->hdr->pending_delete) {
-            /* Set local info, so array deletion can occur after decrementing the
-             *  header's ref count
-             */
-            pending_delete = TRUE;
-            fa_addr = fa->hdr->addr;
+    /* Close the header, if it was set */
+    if(fa->hdr) {
+        /* Decrement file reference & check if this is the last open fixed array using the shared array header */
+        if(0 == H5FA__hdr_fuse_decr(fa->hdr)) {
+            /* Set the shared array header's file context for this operation */
+            fa->hdr->f = fa->f;
+
+            /* Shut down anything that can't be put in the header's 'flush' callback */
+
+            /* Check for pending array deletion */
+            if(fa->hdr->pending_delete) {
+                /* Set local info, so array deletion can occur after decrementing the
+                 *  header's ref count
+                 */
+                pending_delete = TRUE;
+                fa_addr = fa->hdr->addr;
+            } /* end if */
         } /* end if */
-    } /* end if */
 
-    /* Check for pending array deletion */
-    if(pending_delete) {
-        H5FA_hdr_t *hdr;            /* Another pointer to fixed array header */
+        /* Check for pending array deletion */
+        if(pending_delete) {
+            H5FA_hdr_t *hdr;            /* Another pointer to fixed array header */
 
 #ifndef NDEBUG
 {
@@ -570,33 +591,34 @@ H5FA_close(H5FA_t *fa, hid_t dxpl_id))
 }
 #endif /* NDEBUG */
 
-        /* Lock the array header into memory */
-        /* (OK to pass in NULL for callback context, since we know the header must be in the cache) */
-        if(NULL == (hdr = H5FA__hdr_protect(fa->f, dxpl_id, fa_addr, NULL, H5AC__NO_FLAGS_SET)))
-            H5E_THROW(H5E_CANTLOAD, "unable to load fixed array header")
+            /* Lock the array header into memory */
+            /* (OK to pass in NULL for callback context, since we know the header must be in the cache) */
+            if(NULL == (hdr = H5FA__hdr_protect(fa->f, dxpl_id, fa_addr, NULL, H5AC__NO_FLAGS_SET)))
+                H5E_THROW(H5E_CANTLOAD, "unable to load fixed array header")
 
-        /* Set the shared array header's file context for this operation */
-        hdr->f = fa->f;
+            /* Set the shared array header's file context for this operation */
+            hdr->f = fa->f;
 
-        /* Decrement the reference count on the array header */
-        /* (don't put in H5FA_hdr_fuse_decr() as the array header may be evicted
-         *  immediately -QAK)
-         */
-        if(H5FA__hdr_decr(fa->hdr) < 0)
-            H5E_THROW(H5E_CANTDEC, "can't decrement reference count on shared array header")
+            /* Decrement the reference count on the array header */
+            /* (don't put in H5FA_hdr_fuse_decr() as the array header may be evicted
+             *  immediately -QAK)
+             */
+            if(H5FA__hdr_decr(fa->hdr) < 0)
+                H5E_THROW(H5E_CANTDEC, "can't decrement reference count on shared array header")
 
-        /* Delete array, starting with header (unprotects header) */
-        if(H5FA__hdr_delete(hdr, dxpl_id) < 0)
-            H5E_THROW(H5E_CANTDELETE, "unable to delete fixed array")
+            /* Delete array, starting with header (unprotects header) */
+            if(H5FA__hdr_delete(hdr, dxpl_id) < 0)
+                H5E_THROW(H5E_CANTDELETE, "unable to delete fixed array")
+        } /* end if */
+        else {
+            /* Decrement the reference count on the array header */
+            /* (don't put in H5FA_hdr_fuse_decr() as the array header may be evicted
+             *  immediately -QAK)
+             */
+            if(H5FA__hdr_decr(fa->hdr) < 0)
+                H5E_THROW(H5E_CANTDEC, "can't decrement reference count on shared array header")
+        } /* end else */
     } /* end if */
-    else {
-        /* Decrement the reference count on the array header */
-        /* (don't put in H5FA_hdr_fuse_decr() as the array header may be evicted
-         *  immediately -QAK)
-         */
-        if(H5FA__hdr_decr(fa->hdr) < 0)
-            H5E_THROW(H5E_CANTDEC, "can't decrement reference count on shared array header")
-    } /* end else */
 
     /* Release the fixed array wrapper */
     fa = H5FL_FREE(H5FA_t, fa);
diff --git a/src/H5FAhdr.c b/src/H5FAhdr.c
index d844f06..d6e32dc 100644
--- a/src/H5FAhdr.c
+++ b/src/H5FAhdr.c
@@ -119,6 +119,7 @@ H5FA__hdr_alloc(H5F_t *f))
     ret_value = hdr;
 
 CATCH
+
     if(!ret_value)
         if(hdr && H5FA__hdr_dest(hdr) < 0)
             H5E_THROW(H5E_CANTFREE, "unable to destroy fixed array header")
@@ -225,6 +226,7 @@ H5FA__hdr_create(H5F_t *f, hid_t dxpl_id, const H5FA_create_t *cparam,
     ret_value = hdr->addr;
 
 CATCH
+
     if(!H5F_addr_defined(ret_value))
         if(hdr) {
             /* Release header's disk space */
diff --git a/src/H5FDcore.c b/src/H5FDcore.c
index f29e231..9090679 100644
--- a/src/H5FDcore.c
+++ b/src/H5FDcore.c
@@ -1479,23 +1479,31 @@ done:
 static herr_t
 H5FD_core_lock(H5FD_t *_file, hbool_t rw)
 {
-    H5FD_core_t *file = (H5FD_core_t*)_file;	/* VFD file struct */
-    int lock;					/* The type of lock */
-    herr_t ret_value = SUCCEED;                 /* Return value */
+    H5FD_core_t *file = (H5FD_core_t*)_file;    /* VFD file struct          */
+    int lock_flags;                             /* file locking flags       */
+    herr_t ret_value = SUCCEED;                 /* Return value             */
 
     FUNC_ENTER_NOAPI_NOINIT
 
     HDassert(file);
+
+    /* Only set the lock if there is a file descriptor. If no file
+     * descriptor, this is a no-op.
+     */
     if(file->fd >= 0) {
 
-	/* Determine the type of lock */
-	lock = rw ? LOCK_EX : LOCK_SH;
-    
-	/* Place the lock with non-blocking */
-	if(HDflock(file->fd, lock | LOCK_NB) < 0)
-	    HSYS_GOTO_ERROR(H5E_FILE, H5E_BADFILE, FAIL, "unable to flock file")
-    }
-    /* Otherwise a noop */
+        /* Set exclusive or shared lock based on rw status */
+        lock_flags = rw ? LOCK_EX : LOCK_SH;
+
+        /* Place a non-blocking lock on the file */
+        if(HDflock(file->fd, lock_flags | LOCK_NB) < 0) {
+            if(ENOSYS == errno)
+                HSYS_GOTO_ERROR(H5E_FILE, H5E_BADFILE, FAIL, "file locking disabled on this file system (use HDF5_USE_FILE_LOCKING environment variable to override)")
+            else
+                HSYS_GOTO_ERROR(H5E_FILE, H5E_BADFILE, FAIL, "unable to lock file")
+        } /* end if */
+
+    } /* end if */
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
@@ -1525,11 +1533,16 @@ H5FD_core_unlock(H5FD_t *_file)
 
     if(file->fd >= 0) {
 
-	if(HDflock(file->fd, LOCK_UN) < 0)
-	    HSYS_GOTO_ERROR(H5E_FILE, H5E_BADFILE, FAIL, "unable to flock (unlock) file")
-    }
-    /* Otherwise a noop */
+        if(HDflock(file->fd, LOCK_UN) < 0) {
+            if(ENOSYS == errno)
+                HSYS_GOTO_ERROR(H5E_FILE, H5E_BADFILE, FAIL, "file locking disabled on this file system (use HDF5_USE_FILE_LOCKING environment variable to override)")
+            else
+                HSYS_GOTO_ERROR(H5E_FILE, H5E_BADFILE, FAIL, "unable to unlock file")
+        } /* end if */
+
+    } /* end if */
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5FD_core_unlock() */
+
diff --git a/src/H5FDfamily.c b/src/H5FDfamily.c
index 7ec8751..f0d4dba 100644
--- a/src/H5FDfamily.c
+++ b/src/H5FDfamily.c
@@ -1339,33 +1339,37 @@ done:
 static herr_t
 H5FD_family_lock(H5FD_t *_file, hbool_t rw)
 {
-    H5FD_family_t *file = (H5FD_family_t *)_file;   	/* VFD file struct */
-    unsigned	u, i;      	/* Local index variable */
-    herr_t ret_value = SUCCEED;	/* Return value */
+    H5FD_family_t *file = (H5FD_family_t *)_file;   /* VFD file struct */
+    unsigned u;                         /* Local index variable */
+    herr_t ret_value = SUCCEED;	        /* Return value */
 
     FUNC_ENTER_NOAPI_NOINIT
 
     /* Place the lock on all the member files */
-    for(u = 0; u < file->nmembs; u++) {
-        if(file->memb[u]) {
+    for(u = 0; u < file->nmembs; u++)
+        if(file->memb[u])
             if(H5FD_lock(file->memb[u], rw) < 0)
-		break;
-        } /* end if */
-    } /* end for */
+                break;
 
-    if(u < file->nmembs) { /* Try to unlock the member files done before */
-	for(i = 0; i < u; i++) {
-	    if(H5FD_unlock(file->memb[i]) < 0)
-		/* Push error, but keep going*/
-		HDONE_ERROR(H5E_IO, H5E_CANTUNLOCK, FAIL, "unable to unlock member files")
-	}
-	HGOTO_ERROR(H5E_IO, H5E_CANTLOCK, FAIL, "unable to lock member files")
+    /* If one of the locks failed, try to unlock the locked member files
+     * in an attempt to return to a fully unlocked state.
+     */
+    if(u < file->nmembs) {
+        unsigned v;                         /* Local index variable */
+
+        for(v = 0; v < v; v++) {
+            if(H5FD_unlock(file->memb[v]) < 0)
+                /* Push error, but keep going */
+                HDONE_ERROR(H5E_IO, H5E_CANTUNLOCK, FAIL, "unable to unlock member files")
+        } /* end for */
+        HGOTO_ERROR(H5E_IO, H5E_CANTLOCK, FAIL, "unable to lock member files")
     } /* end if */
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5FD_family_lock() */
 
+
 /*-------------------------------------------------------------------------
  * Function:    H5FD_family_unlock
  *
@@ -1381,19 +1385,18 @@ static herr_t
 H5FD_family_unlock(H5FD_t *_file)
 {
     H5FD_family_t *file = (H5FD_family_t *)_file;   	/* VFD file struct */
-    unsigned	u;      	/* Local index variable */
-    herr_t ret_value = SUCCEED;	/* Return value */
+    unsigned	u;                                      /* Local index variable */
+    herr_t ret_value = SUCCEED;                         /* Return value */
 
     FUNC_ENTER_NOAPI_NOINIT
 
     /* Remove the lock on the member files */
-    for(u = 0; u < file->nmembs; u++) {
-        if(file->memb[u]) {
+    for(u = 0; u < file->nmembs; u++)
+        if(file->memb[u])
             if(H5FD_unlock(file->memb[u]) < 0)
-		HGOTO_ERROR(H5E_IO, H5E_CANTUNLOCK, FAIL, "unable to unlock member files")
-        } /* end if */
-    } /* end for */
+                HGOTO_ERROR(H5E_IO, H5E_CANTUNLOCK, FAIL, "unable to unlock member files")
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5FD_family_unlock() */
+
diff --git a/src/H5FDlog.c b/src/H5FDlog.c
index 9f5dfa5..a2891cb 100644
--- a/src/H5FDlog.c
+++ b/src/H5FDlog.c
@@ -1567,15 +1567,7 @@ static herr_t
 H5FD_log_truncate(H5FD_t *_file, hid_t H5_ATTR_UNUSED dxpl_id, hbool_t H5_ATTR_UNUSED closing)
 {
     H5FD_log_t  *file = (H5FD_log_t *)_file;
-#ifdef H5_HAVE_WIN32_API
-        LARGE_INTEGER   li;         /* 64-bit (union) integer for SetFilePointer() call */
-        DWORD           dwPtrLow;   /* Low-order pointer bits from SetFilePointer()
-                                     * Only used as an error code here.
-                                     */
-        DWORD           dwError;    /* DWORD error code from GetLastError() */
-        BOOL            bError;     /* Boolean error flag */
-#endif /* H5_HAVE_WIN32_API */
-herr_t      ret_value = SUCCEED;                /* Return value */
+    herr_t      ret_value = SUCCEED;                /* Return value */
 
     FUNC_ENTER_NOAPI_NOINIT
 
@@ -1586,6 +1578,14 @@ herr_t      ret_value = SUCCEED;                /* Return value */
 #ifdef H5_HAVE_GETTIMEOFDAY
         struct timeval timeval_start, timeval_stop;
 #endif /* H5_HAVE_GETTIMEOFDAY */
+#ifdef H5_HAVE_WIN32_API
+        LARGE_INTEGER   li;         /* 64-bit (union) integer for SetFilePointer() call */
+        DWORD           dwPtrLow;   /* Low-order pointer bits from SetFilePointer()
+                                     * Only used as an error code here.
+                                     */
+        DWORD           dwError;    /* DWORD error code from GetLastError() */
+        BOOL            bError;     /* Boolean error flag */
+#endif /* H5_HAVE_WIN32_API */
 
 #ifdef H5_HAVE_GETTIMEOFDAY
         if(file->fa.flags & H5FD_LOG_TIME_TRUNCATE)
@@ -1677,21 +1677,25 @@ done:
 static herr_t
 H5FD_log_lock(H5FD_t *_file, hbool_t rw)
 {
-    H5FD_log_t	*file = (H5FD_log_t *)_file;
-    int lock;
-    herr_t ret_value = SUCCEED;                 /* Return value */
+    H5FD_log_t	*file = (H5FD_log_t *)_file;    /* VFD file struct          */
+    int lock_flags;                             /* file locking flags       */
+    herr_t ret_value = SUCCEED;                 /* Return value             */
 
     FUNC_ENTER_NOAPI_NOINIT
 
     /* Sanity check */
     HDassert(file);
 
-    /* Determine the type of lock */
-    lock = rw ? LOCK_EX : LOCK_SH;
+    /* Set exclusive or shared lock based on rw status */
+    lock_flags = rw ? LOCK_EX : LOCK_SH;
 
-    /* Place the lock with non-blocking */
-    if(HDflock(file->fd, lock | LOCK_NB) < 0)
-        HSYS_GOTO_ERROR(H5E_FILE, H5E_BADFILE, FAIL, "unable to flock file")
+    /* Place a non-blocking lock on the file */
+    if(HDflock(file->fd, lock_flags | LOCK_NB) < 0) {
+        if(ENOSYS == errno)
+            HSYS_GOTO_ERROR(H5E_FILE, H5E_BADFILE, FAIL, "file locking disabled on this file system (use HDF5_USE_FILE_LOCKING environment variable to override)")
+        else
+            HSYS_GOTO_ERROR(H5E_FILE, H5E_BADFILE, FAIL, "unable to lock file")
+    } /* end if */
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
@@ -1712,15 +1716,19 @@ done:
 static herr_t
 H5FD_log_unlock(H5FD_t *_file)
 {
-    H5FD_log_t  *file = (H5FD_log_t *)_file;       /* VFD file struct */
-    herr_t ret_value = SUCCEED;                         /* Return value */
+    H5FD_log_t  *file = (H5FD_log_t *)_file;    /* VFD file struct          */
+    herr_t ret_value = SUCCEED;                 /* Return value             */
 
     FUNC_ENTER_NOAPI_NOINIT
 
     HDassert(file);
 
-    if(HDflock(file->fd, LOCK_UN) < 0)
-        HSYS_GOTO_ERROR(H5E_FILE, H5E_BADFILE, FAIL, "unable to flock (unlock) file")
+    if(HDflock(file->fd, LOCK_UN) < 0) {
+        if(ENOSYS == errno)
+            HSYS_GOTO_ERROR(H5E_FILE, H5E_BADFILE, FAIL, "file locking disabled on this file system (use HDF5_USE_FILE_LOCKING environment variable to override)")
+        else
+            HSYS_GOTO_ERROR(H5E_FILE, H5E_BADFILE, FAIL, "unable to unlock file")
+    } /* end if */
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
diff --git a/src/H5FDsec2.c b/src/H5FDsec2.c
index bb8f004..04a0790 100644
--- a/src/H5FDsec2.c
+++ b/src/H5FDsec2.c
@@ -922,20 +922,24 @@ done:
 static herr_t
 H5FD_sec2_lock(H5FD_t *_file, hbool_t rw)
 {
-    H5FD_sec2_t *file = (H5FD_sec2_t *)_file;	/* VFD file struct */
-    int lock;					/* The type of lock */
-    herr_t ret_value = SUCCEED;                 /* Return value */
+    H5FD_sec2_t *file = (H5FD_sec2_t *)_file;   /* VFD file struct          */
+    int lock_flags;                             /* file locking flags       */
+    herr_t ret_value = SUCCEED;                 /* Return value             */
 
     FUNC_ENTER_NOAPI_NOINIT
 
     HDassert(file);
 
-    /* Determine the type of lock */
-    lock = rw ? LOCK_EX : LOCK_SH;
-    
-    /* Place the lock with non-blocking */
-    if(HDflock(file->fd, lock | LOCK_NB) < 0)
-        HSYS_GOTO_ERROR(H5E_FILE, H5E_BADFILE, FAIL, "unable to flock file")
+    /* Set exclusive or shared lock based on rw status */
+    lock_flags = rw ? LOCK_EX : LOCK_SH;
+
+    /* Place a non-blocking lock on the file */
+    if(HDflock(file->fd, lock_flags | LOCK_NB) < 0) {
+        if(ENOSYS == errno)
+            HSYS_GOTO_ERROR(H5E_FILE, H5E_BADFILE, FAIL, "file locking disabled on this file system (use HDF5_USE_FILE_LOCKING environment variable to override)")
+        else
+            HSYS_GOTO_ERROR(H5E_FILE, H5E_BADFILE, FAIL, "unable to lock file")
+    } /* end if */
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
@@ -956,15 +960,19 @@ done:
 static herr_t
 H5FD_sec2_unlock(H5FD_t *_file)
 {
-    H5FD_sec2_t *file = (H5FD_sec2_t *)_file;	/* VFD file struct */
-    herr_t ret_value = SUCCEED;                 /* Return value */
+    H5FD_sec2_t *file = (H5FD_sec2_t *)_file;   /* VFD file struct          */
+    herr_t ret_value = SUCCEED;                 /* Return value             */
 
     FUNC_ENTER_NOAPI_NOINIT
 
     HDassert(file);
 
-    if(HDflock(file->fd, LOCK_UN) < 0)
-        HSYS_GOTO_ERROR(H5E_FILE, H5E_BADFILE, FAIL, "unable to flock (unlock) file")
+    if(HDflock(file->fd, LOCK_UN) < 0) {
+        if(ENOSYS == errno)
+            HSYS_GOTO_ERROR(H5E_FILE, H5E_BADFILE, FAIL, "file locking disabled on this file system (use HDF5_USE_FILE_LOCKING environment variable to override)")
+        else
+            HSYS_GOTO_ERROR(H5E_FILE, H5E_BADFILE, FAIL, "unable to unlock file")
+    } /* end if */
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
diff --git a/src/H5FDstdio.c b/src/H5FDstdio.c
index 0168ff4..7056f7f 100644
--- a/src/H5FDstdio.c
+++ b/src/H5FDstdio.c
@@ -24,6 +24,7 @@
  *          and is not intended for production use!
  */
 #include <assert.h>
+#include <errno.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -1078,8 +1079,8 @@ H5FD_stdio_truncate(H5FD_t *_file, hid_t /*UNUSED*/ dxpl_id,
  * Function:    H5FD_stdio_lock
  *
  * Purpose:     Lock a file via flock
- *
  *              NOTE: This function is a no-op if flock() is not present.
+ *
  * Errors:
  *    IO    FCNTL    flock failed.
  *
@@ -1093,21 +1094,27 @@ static herr_t
 H5FD_stdio_lock(H5FD_t *_file, hbool_t rw)
 {
 #ifdef H5_HAVE_FLOCK
-    H5FD_stdio_t  *file = (H5FD_stdio_t*)_file;
-    int lock;                                   	/* The type of lock */
-    static const char *func = "H5FD_stdio_lock";  	/* Function Name for error reporting */
+    H5FD_stdio_t  *file = (H5FD_stdio_t*)_file;     /* VFD file struct                      */
+    int lock_flags;                                 /* file locking flags                   */
+    static const char *func = "H5FD_stdio_lock";  	/* Function Name for error reporting    */
 
     /* Clear the error stack */
     H5Eclear2(H5E_DEFAULT);
 
     assert(file);
 
-    /* Determine the type of lock */
-    lock = rw ? LOCK_EX : LOCK_SH;
+    /* Set exclusive or shared lock based on rw status */
+    lock_flags = rw ? LOCK_EX : LOCK_SH;
 
-    /* Place the lock with non-blocking */
-    if(flock(file->fd, lock | LOCK_NB) < 0)
-        H5Epush_ret(func, H5E_ERR_CLS, H5E_IO, H5E_FCNTL, "flock failed", -1)
+    /* Place a non-blocking lock on the file */
+    if(flock(file->fd, lock_flags | LOCK_NB) < 0) {
+        if(ENOSYS == errno)
+            H5Epush_ret(func, H5E_ERR_CLS, H5E_IO, H5E_FCNTL, "file locking disabled on this file system (use HDF5_USE_FILE_LOCKING environment variable to override)", -1)
+        else
+            H5Epush_ret(func, H5E_ERR_CLS, H5E_IO, H5E_FCNTL, "file lock failed", -1)
+    } /* end if */
+
+    /* Flush the stream */
     if(fflush(file->fp) < 0)
         H5Epush_ret(func, H5E_ERR_CLS, H5E_IO, H5E_WRITEERROR, "fflush failed", -1)
 
@@ -1117,16 +1124,15 @@ H5FD_stdio_lock(H5FD_t *_file, hbool_t rw)
 } /* end H5FD_stdio_lock() */
 
 /*-------------------------------------------------------------------------
- * Function:  H5F_stdio_unlock
- *
- * Purpose:  Unlock a file via flock
+ * Function:    H5F_stdio_unlock
  *
+ * Purpose:     Unlock a file via flock
+ *              NOTE: This function is a no-op if flock() is not present.
  *
- *           NOTE: This function is a no-op if flock() is not present.
  * Errors:
  *    IO    FCNTL    flock failed.
  *
- * Return:  Non-negative on success/Negative on failure
+ * Return:      Non-negative on success/Negative on failure
  *
  * Programmer:  Vailin Choi; March 2015
  *
@@ -1136,18 +1142,25 @@ static herr_t
 H5FD_stdio_unlock(H5FD_t *_file)
 {
 #ifdef H5_HAVE_FLOCK
-    H5FD_stdio_t  *file = (H5FD_stdio_t*)_file;
-    static const char *func = "H5FD_stdio_unlock";  	/* Function Name for error reporting */
+    H5FD_stdio_t  *file = (H5FD_stdio_t*)_file;         /* VFD file struct                      */
+    static const char *func = "H5FD_stdio_unlock";  	/* Function Name for error reporting    */
 
     /* Clear the error stack */
     H5Eclear2(H5E_DEFAULT);
 
     assert(file);
 
+    /* Flush the stream */
     if(fflush(file->fp) < 0)
         H5Epush_ret(func, H5E_ERR_CLS, H5E_IO, H5E_WRITEERROR, "fflush failed", -1)
-    if(flock(file->fd, LOCK_UN) < 0)
-        H5Epush_ret(func, H5E_ERR_CLS, H5E_IO, H5E_FCNTL, "flock (unlock) failed", -1)
+
+    /* Place a non-blocking lock on the file */
+    if(flock(file->fd, LOCK_UN) < 0) {
+        if(ENOSYS == errno)
+            H5Epush_ret(func, H5E_ERR_CLS, H5E_IO, H5E_FCNTL, "file locking disabled on this file system (use HDF5_USE_FILE_LOCKING environment variable to override)", -1)
+        else
+            H5Epush_ret(func, H5E_ERR_CLS, H5E_IO, H5E_FCNTL, "file unlock failed", -1)
+    } /* end if */
 
 #endif /* H5_HAVE_FLOCK */
 
diff --git a/src/H5Fint.c b/src/H5Fint.c
index dbaf3cc..152148d 100644
--- a/src/H5Fint.c
+++ b/src/H5Fint.c
@@ -171,6 +171,8 @@ H5F_get_access_plist(H5F_t *f, hbool_t app_ref)
         latest_format = TRUE;
     if(H5P_set(new_plist, H5F_ACS_LATEST_FORMAT_NAME, &latest_format) < 0)
         HGOTO_ERROR(H5E_PLIST, H5E_CANTSET, FAIL, "can't set 'latest format' flag")
+    if(H5P_set(new_plist, H5F_ACS_METADATA_READ_ATTEMPTS_NAME, &(f->shared->read_attempts)) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTSET, FAIL, "can't set 'read attempts ' flag")
     if(H5P_set(new_plist, H5F_ACS_OBJECT_FLUSH_CB_NAME, &(f->shared->object_flush)) < 0)
         HGOTO_ERROR(H5E_PLIST, H5E_CANTSET, FAIL, "can't set object flush callback")
 
@@ -998,6 +1000,8 @@ H5F_open(const char *name, unsigned flags, hid_t fcpl_id, hid_t fapl_id,
     H5F_close_degree_t  fc_degree;          /*file close degree             */
     hbool_t             evict_on_close;     /* evict on close value from plist  */
     H5F_t              *ret_value = NULL;   /*actual return value           */
+    char               *lock_env_var = NULL;/*env var pointer               */
+    hbool_t             use_file_locking;   /*read from env var             */
 
     FUNC_ENTER_NOAPI(NULL)
 
@@ -1012,6 +1016,16 @@ H5F_open(const char *name, unsigned flags, hid_t fcpl_id, hid_t fapl_id,
     if(NULL == (drvr = H5FD_get_class(fapl_id)))
         HGOTO_ERROR(H5E_FILE, H5E_CANTGET, NULL, "unable to retrieve VFL class")
 
+    /* Check the environment variable that determines if we care
+     * about file locking. File locking should be used unless explicitly
+     * disabled.
+     */
+    lock_env_var = HDgetenv("HDF5_USE_FILE_LOCKING");
+    if(lock_env_var && !HDstrcmp(lock_env_var, "FALSE"))
+        use_file_locking = FALSE;
+    else
+        use_file_locking = TRUE;    
+
     /*
      * Opening a file is a two step process. First we try to open the
      * file in a way which doesn't affect its state (like not truncating
@@ -1024,52 +1038,52 @@ H5F_open(const char *name, unsigned flags, hid_t fcpl_id, hid_t fapl_id,
      * way for us to detect it here anyway).
      */
     if(drvr->cmp)
-	tent_flags = flags & ~(H5F_ACC_CREAT|H5F_ACC_TRUNC|H5F_ACC_EXCL);
+        tent_flags = flags & ~(H5F_ACC_CREAT|H5F_ACC_TRUNC|H5F_ACC_EXCL);
     else
-	tent_flags = flags;
+        tent_flags = flags;
 
     if(NULL == (lf = H5FD_open(name, tent_flags, fapl_id, HADDR_UNDEF))) {
-	if(tent_flags == flags) {
+        if(tent_flags == flags) {
 #ifndef H5_USING_MEMCHECKER
             time_t mytime = HDtime(NULL);
 
-	    HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL, "unable to open file: time = %s, name = '%s', tent_flags = %x", HDctime(&mytime), name, tent_flags)
+            HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL, "unable to open file: time = %s, name = '%s', tent_flags = %x", HDctime(&mytime), name, tent_flags)
 #else /* H5_USING_MEMCHECKER */
-	    HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL, "unable to open file: name = '%s', tent_flags = %x", name, tent_flags)
+            HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL, "unable to open file: name = '%s', tent_flags = %x", name, tent_flags)
 #endif /* H5_USING_MEMCHECKER */
         } /* end if */
         H5E_clear_stack(NULL);
-	tent_flags = flags;
-	if(NULL == (lf = H5FD_open(name, tent_flags, fapl_id, HADDR_UNDEF))) {
+        tent_flags = flags;
+        if(NULL == (lf = H5FD_open(name, tent_flags, fapl_id, HADDR_UNDEF))) {
 #ifndef H5_USING_MEMCHECKER
             time_t mytime = HDtime(NULL);
 
-	    HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL, "unable to open file: time = %s, name = '%s', tent_flags = %x", HDctime(&mytime), name, tent_flags)
+            HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL, "unable to open file: time = %s, name = '%s', tent_flags = %x", HDctime(&mytime), name, tent_flags)
 #else /* H5_USING_MEMCHECKER */
-	    HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL, "unable to open file: name = '%s', tent_flags = %x", name, tent_flags)
+            HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL, "unable to open file: name = '%s', tent_flags = %x", name, tent_flags)
 #endif /* H5_USING_MEMCHECKER */
         } /* end if */
     } /* end if */
 
     /* Is the file already open? */
     if((shared = H5F_sfile_search(lf)) != NULL) {
-	/*
-	 * The file is already open, so use that one instead of the one we
-	 * just opened. We only one one H5FD_t* per file so one doesn't
-	 * confuse the other.  But fail if this request was to truncate the
-	 * file (since we can't do that while the file is open), or if the
-	 * request was to create a non-existent file (since the file already
-	 * exists), or if the new request adds write access (since the
-	 * readers don't expect the file to change under them).
-	 */
-	if(H5FD_close(lf) < 0)
-	    HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL, "unable to close low-level file info")
-	if(flags & H5F_ACC_TRUNC)
-	    HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL, "unable to truncate a file which is already open")
-	if(flags & H5F_ACC_EXCL)
-	    HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL, "file exists")
-	if((flags & H5F_ACC_RDWR) && 0 == (shared->flags & H5F_ACC_RDWR))
-	    HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL, "file is already open for read-only")
+        /*
+         * The file is already open, so use that one instead of the one we
+         * just opened. We only one one H5FD_t* per file so one doesn't
+         * confuse the other.  But fail if this request was to truncate the
+         * file (since we can't do that while the file is open), or if the
+         * request was to create a non-existent file (since the file already
+         * exists), or if the new request adds write access (since the
+         * readers don't expect the file to change under them).
+         */
+        if(H5FD_close(lf) < 0)
+            HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL, "unable to close low-level file info")
+        if(flags & H5F_ACC_TRUNC)
+            HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL, "unable to truncate a file which is already open")
+        if(flags & H5F_ACC_EXCL)
+            HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL, "file exists")
+        if((flags & H5F_ACC_RDWR) && 0 == (shared->flags & H5F_ACC_RDWR))
+            HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL, "file is already open for read-only")
 
         /* Allocate new "high-level" file struct */
         if((file = H5F_new(shared, flags, fcpl_id, fapl_id, NULL)) == NULL)
@@ -1089,8 +1103,19 @@ H5F_open(const char *name, unsigned flags, hid_t fcpl_id, hid_t fapl_id,
             if(NULL == (lf = H5FD_open(name, flags, fapl_id, HADDR_UNDEF)))
                 HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL, "unable to open file")
         } /* end if */
+
+        /* Place an advisory lock on the file */
+        if(use_file_locking)
+            if(H5FD_lock(lf, (hbool_t)((flags & H5F_ACC_RDWR) ? TRUE : FALSE)) < 0) {
+                /* Locking failed - Closing will remove the lock */                
+                if(H5FD_close(lf) < 0) 
+                    HDONE_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL, "unable to close low-level file info")
+                HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL, "unable to lock the file")
+            } /* end if */
+
+        /* Create the 'top' file structure */
         if(NULL == (file = H5F_new(NULL, flags, fcpl_id, fapl_id, lf)))
-            HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL, "unable to create new file object")
+            HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL, "unable to initialize file structure")
     } /* end else */
 
     /* Retain the name the file was opened with */
@@ -1121,15 +1146,16 @@ H5F_open(const char *name, unsigned flags, hid_t fcpl_id, hid_t fapl_id,
          */
         if(H5G_mkroot(file, dxpl_id, TRUE) < 0)
             HGOTO_ERROR(H5E_FILE, H5E_CANTINIT, NULL, "unable to create/open root group")
-    } else if (1 == shared->nrefs) {
+    } /* end if */
+    else if (1 == shared->nrefs) {
 
-	/* Read the superblock if it hasn't been read before. */
+        /* Read the superblock if it hasn't been read before. */
         if(H5F__super_read(file, dxpl_id, TRUE) < 0)
-	    HGOTO_ERROR(H5E_FILE, H5E_READERROR, NULL, "unable to read superblock")
+            HGOTO_ERROR(H5E_FILE, H5E_READERROR, NULL, "unable to read superblock")
 
-	/* Open the root group */
-	if(H5G_mkroot(file, dxpl_id, FALSE) < 0)
-	    HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL, "unable to read root group")
+        /* Open the root group */
+        if(H5G_mkroot(file, dxpl_id, FALSE) < 0)
+            HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL, "unable to read root group")
     } /* end if */
 
     /* Get the file access property list, for future queries */
@@ -1150,7 +1176,8 @@ H5F_open(const char *name, unsigned flags, hid_t fcpl_id, hid_t fapl_id,
             shared->fc_degree = lf->cls->fc_degree;
         else
             shared->fc_degree = fc_degree;
-    } else if(shared->nrefs > 1) {
+    } /* end if */
+    else if(shared->nrefs > 1) {
         if(fc_degree == H5F_CLOSE_DEFAULT && shared->fc_degree != lf->cls->fc_degree)
             HGOTO_ERROR(H5E_FILE, H5E_CANTINIT, NULL, "file close degree doesn't match")
         if(fc_degree != H5F_CLOSE_DEFAULT && fc_degree != shared->fc_degree)
@@ -1174,19 +1201,19 @@ H5F_open(const char *name, unsigned flags, hid_t fcpl_id, hid_t fapl_id,
 
     /* Formulate the absolute path for later search of target file for external links */
     if(H5_build_extpath(name, &file->extpath) < 0)
-	HGOTO_ERROR(H5E_FILE, H5E_CANTINIT, NULL, "unable to build extpath")
+        HGOTO_ERROR(H5E_FILE, H5E_CANTINIT, NULL, "unable to build extpath")
 
     /* Formulate the actual file name, after following symlinks, etc. */
     if(H5F_build_actual_name(file, a_plist, name, &file->actual_name) < 0)
-	HGOTO_ERROR(H5E_FILE, H5E_CANTINIT, NULL, "unable to build actual name")
+        HGOTO_ERROR(H5E_FILE, H5E_CANTINIT, NULL, "unable to build actual name")
 
     /* Success */
     ret_value = file;
 
 done:
     if(!ret_value && file)
-	if(H5F_dest(file, dxpl_id, FALSE) < 0)
-	    HDONE_ERROR(H5E_FILE, H5E_CANTCLOSEFILE, NULL, "problems closing file")
+        if(H5F_dest(file, dxpl_id, FALSE) < 0)
+            HDONE_ERROR(H5E_FILE, H5E_CANTCLOSEFILE, NULL, "problems closing file")
 
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5F_open() */
diff --git a/src/H5Zscaleoffset.c b/src/H5Zscaleoffset.c
index 91a6c00..1cca9b1 100644
--- a/src/H5Zscaleoffset.c
+++ b/src/H5Zscaleoffset.c
@@ -667,58 +667,6 @@ H5Z_class2_t H5Z_SCALEOFFSET[1] = {{
       H5Z_scaleoffset_modify_4(i, type, pow_fun, buf, d_nelmts, min, D_val)                     \
 }
 
-/* Include our own rounding routine and alias it to the stdc macros, if they
- *      aren't available.
- */
-#if !(defined(H5_HAVE_LLROUND) && defined(H5_HAVE_LLROUNDF) && defined(H5_HAVE_LROUND) && defined(H5_HAVE_LROUNDF) && defined(H5_HAVE_ROUND) && defined(H5_HAVE_ROUNDF))
-/* Round a floating-point value to the nearest integer value 4/19/05 */
-/* rounding to the bigger absolute value if val is in the middle,
- 0.5 -> 1, -0.5 ->-1
-5/9/05, KY */
-static double
-H5Z__scaleoffset_rnd(double val)
-{
-    double u_val, l_val;
-
-    u_val = HDceil(val);
-    l_val = HDfloor(val);
-
-    if(val > 0) {
-        if((u_val - val) <= (val - l_val))
-            return u_val;
-        else
-            return l_val;
-    } /* end if */
-    else {
-        if((val - l_val) <= (u_val - val))
-            return l_val;
-        else
-            return u_val;
-    }
-} /* H5Z__scaleoffset_rnd() */
-
-/* Alias rounding macros to routine above, if not defined */
-#if !defined(H5_HAVE_LLROUND)
-#define llround(x) H5Z__scaleoffset_rnd(x)
-#endif /* !defined(H5_HAVE_LLROUND) */
-#if !defined(H5_HAVE_LLROUNDF)
-#define llroundf(x) H5Z__scaleoffset_rnd(x)
-#endif /* !defined(H5_HAVE_LLROUNDF) */
-#if !defined(H5_HAVE_LROUND)
-#define lround(x) H5Z__scaleoffset_rnd(x)
-#endif /* !defined(H5_HAVE_LROUND) */
-#if !defined(H5_HAVE_LROUNDF)
-#define lroundf(x) H5Z__scaleoffset_rnd(x)
-#endif /* !defined(H5_HAVE_LROUNDF) */
-#if !defined(H5_HAVE_ROUND)
-#define round(x) H5Z__scaleoffset_rnd(x)
-#endif /* !defined(H5_HAVE_ROUND) */
-#if !defined(H5_HAVE_ROUNDF)
-#define roundf(x) H5Z__scaleoffset_rnd(x)
-#endif /* !defined(H5_HAVE_ROUNDF) */
-
-#endif /* !(defined(H5_HAVE_LLROUND) && defined(H5_HAVE_LLROUNDF) && defined(H5_HAVE_LROUND) && defined(H5_HAVE_LROUNDF) && defined(H5_HAVE_ROUND) && defined(H5_HAVE_ROUNDF)) */
-
 
 /*-------------------------------------------------------------------------
  * Function:	H5Z_can_apply_scaleoffset
diff --git a/test/ohdr.c b/test/ohdr.c
index e613a98..1478c5c 100644
--- a/test/ohdr.c
+++ b/test/ohdr.c
@@ -609,9 +609,8 @@ main(void)
     H5F_t	*f = NULL;
     char	filename[1024];
     H5O_hdr_info_t hdr_info;            /* Object info */
-    H5O_loc_t	oh_loc, oh_loc2;        /* Object header locations */
+    H5O_loc_t	oh_loc;                 /* Object header locations */
     time_t	time_new, ro;
-    int         chunkno;                /* Chunk index for message */
     int		i;                      /* Local index variable */
     unsigned    b;                      /* Index for "new format" loop */
     herr_t      ret;                    /* Generic return value */