Merge initial version of selection I/O feature into develop (#1367)

1 files changed, 581 insertions, 196 deletions

diff --git a/src/H5Dchunk.c b/src/H5Dchunk.c
index e4d8706..8374b17 100644
--- a/src/H5Dchunk.c
+++ b/src/H5Dchunk.c
@@ -59,6 +59,7 @@
 #include "H5Iprivate.h"  /* IDs                      */
 #include "H5MMprivate.h" /* Memory management            */
 #include "H5MFprivate.h" /* File memory management               */
+#include "H5PBprivate.h" /* Page Buffer	                         */
 #include "H5VMprivate.h" /* Vector and array functions        */
 
 /****************/
@@ -70,6 +71,7 @@
 #define H5D_CHUNK_GET_NODE_INFO(map, node)                                                                   \
     (map->use_single ? map->single_chunk_info : (H5D_chunk_info_t *)H5SL_item(node))
 #define H5D_CHUNK_GET_NEXT_NODE(map, node) (map->use_single ? (H5SL_node_t *)NULL : H5SL_next(node))
+#define H5D_CHUNK_GET_NODE_COUNT(map)      (map->use_single ? (size_t)1 : H5SL_count(map->sel_chunks))
 
 /* Sanity check on chunk index types: commonly used by a lot of routines in this file */
 #define H5D_CHUNK_STORAGE_INDEX_CHK(storage)                                                                 \
@@ -261,8 +263,8 @@ typedef struct H5D_chunk_iter_ud_t {
 /* Chunked layout operation callbacks */
 static herr_t H5D__chunk_construct(H5F_t *f, H5D_t *dset);
 static herr_t H5D__chunk_init(H5F_t *f, const H5D_t *dset, hid_t dapl_id);
-static herr_t H5D__chunk_io_init(const H5D_io_info_t *io_info, const H5D_type_info_t *type_info,
-                                 hsize_t nelmts, H5S_t *file_space, H5S_t *mem_space, H5D_chunk_map_t *fm);
+static herr_t H5D__chunk_io_init(H5D_io_info_t *io_info, const H5D_type_info_t *type_info, hsize_t nelmts,
+                                 H5S_t *file_space, H5S_t *mem_space, H5D_chunk_map_t *fm);
 static herr_t H5D__chunk_io_init_selections(const H5D_io_info_t *io_info, const H5D_type_info_t *type_info,
                                             H5D_chunk_map_t *fm);
 static herr_t H5D__chunk_read(H5D_io_info_t *io_info, const H5D_type_info_t *type_info, hsize_t nelmts,
@@ -304,6 +306,7 @@ static herr_t   H5D__chunk_file_cb(void *elem, const H5T_t *type, unsigned ndims
                                    void *fm);
 static herr_t   H5D__chunk_mem_cb(void *elem, const H5T_t *type, unsigned ndims, const hsize_t *coords,
                                   void *fm);
+static htri_t   H5D__chunk_may_use_select_io(const H5D_io_info_t *io_info);
 static unsigned H5D__chunk_hash_val(const H5D_shared_t *shared, const hsize_t *scaled);
 static herr_t   H5D__chunk_flush_entry(const H5D_t *dset, H5D_rdcc_ent_t *ent, hbool_t reset);
 static herr_t   H5D__chunk_cache_evict(const H5D_t *dset, H5D_rdcc_ent_t *ent, hbool_t flush);
@@ -1065,16 +1068,17 @@ H5D__chunk_is_data_cached(const H5D_shared_t *shared_dset)
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5D__chunk_io_init(const H5D_io_info_t *io_info, const H5D_type_info_t *type_info, hsize_t nelmts,
+H5D__chunk_io_init(H5D_io_info_t *io_info, const H5D_type_info_t *type_info, hsize_t nelmts,
                    H5S_t *file_space, H5S_t *mem_space, H5D_chunk_map_t *fm)
 {
     const H5D_t *dataset = io_info->dset;       /* Local pointer to dataset info */
     hssize_t     old_offset[H5O_LAYOUT_NDIMS];  /* Old selection offset */
     htri_t       file_space_normalized = FALSE; /* File dataspace was normalized */
     unsigned     f_ndims;                       /* The number of dimensions of the file's dataspace */
-    int          sm_ndims;            /* The number of dimensions of the memory buffer's dataspace (signed) */
-    unsigned     u;                   /* Local index variable */
-    herr_t       ret_value = SUCCEED; /* Return value        */
+    int          sm_ndims; /* The number of dimensions of the memory buffer's dataspace (signed) */
+    htri_t       use_selection_io = FALSE; /* Whether to use selection I/O */
+    unsigned     u;                        /* Local index variable */
+    herr_t       ret_value = SUCCEED;      /* Return value        */
 
     FUNC_ENTER_STATIC
 
@@ -1128,6 +1132,11 @@ H5D__chunk_io_init(const H5D_io_info_t *io_info, const H5D_type_info_t *type_inf
     if (H5D__chunk_io_init_selections(io_info, type_info, fm) < 0)
         HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "unable to create file and memory chunk selections")
 
+    /* Check if we're performing selection I/O and save the result */
+    if ((use_selection_io = H5D__chunk_may_use_select_io(io_info)) < 0)
+        HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "can't check if selection I/O is possible")
+    io_info->use_select_io = (hbool_t)use_selection_io;
+
 done:
     /* Reset the global dataspace info */
     fm->file_space = NULL;
@@ -2459,6 +2468,78 @@ done:
 } /* end H5D__chunk_cacheable() */
 
 /*-------------------------------------------------------------------------
+ * Function:    H5D__chunk_may_use_select_io
+ *
+ * Purpose:    A small internal function to if it may be possible to use
+ *             selection I/O.
+ *
+ * Return:    TRUE or FALSE
+ *
+ * Programmer:    Neil Fortner
+ *        4 May 2021
+ *
+ *-------------------------------------------------------------------------
+ */
+static htri_t
+H5D__chunk_may_use_select_io(const H5D_io_info_t *io_info)
+{
+    const H5D_t *dataset   = NULL; /* Local pointer to dataset info */
+    htri_t       ret_value = FAIL; /* Return value */
+
+    FUNC_ENTER_STATIC
+
+    /* Sanity check */
+    HDassert(io_info);
+
+    dataset = io_info->dset;
+    HDassert(dataset);
+
+    /* Don't use selection I/O if it's globally disabled, there is a type
+     * conversion, or if there are filters on the dataset (for now) */
+    if (!H5_use_selection_io_g || io_info->io_ops.single_read != H5D__select_read ||
+        dataset->shared->dcpl_cache.pline.nused > 0)
+        ret_value = FALSE;
+    else {
+        hbool_t page_buf_enabled;
+
+        HDassert(io_info->io_ops.single_write == H5D__select_write);
+
+        /* Check if the page buffer is enabled */
+        if (H5PB_enabled(io_info->f_sh, H5FD_MEM_DRAW, &page_buf_enabled) < 0)
+            HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "can't check if page buffer is enabled")
+        if (page_buf_enabled)
+            ret_value = FALSE;
+        else {
+            /* Check if chunks in this dataset may be cached, if so don't use
+             * selection I/O (for now).  Note that chunks temporarily cached for
+             * the purpose of writing the fill value don't count, since they are
+             * immediately evicted. */
+#ifdef H5_HAVE_PARALLEL
+            /* If MPI based VFD is used and the file is opened for write access,
+             * must bypass the chunk-cache scheme because other MPI processes
+             * could be writing to other elements in the same chunk.
+             */
+            if (io_info->using_mpi_vfd && (H5F_ACC_RDWR & H5F_INTENT(dataset->oloc.file)))
+                ret_value = TRUE;
+            else {
+#endif /* H5_HAVE_PARALLEL */
+                /* Check if the chunk is too large to keep in the cache */
+                H5_CHECK_OVERFLOW(dataset->shared->layout.u.chunk.size, uint32_t, size_t);
+                if ((size_t)dataset->shared->layout.u.chunk.size > dataset->shared->cache.chunk.nbytes_max)
+                    ret_value = TRUE;
+                else
+                    ret_value = FALSE;
+#ifdef H5_HAVE_PARALLEL
+            } /* end else */
+#endif        /* H5_HAVE_PARALLEL */
+        }     /* end else */
+    }         /* end else */
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5D__chunk_may_use_select_io() */
+
+/*-------------------------------------------------------------------------
  * Function:    H5D__chunk_read
  *
  * Purpose:    Read from a chunked dataset.
@@ -2474,16 +2555,17 @@ static herr_t
 H5D__chunk_read(H5D_io_info_t *io_info, const H5D_type_info_t *type_info, hsize_t H5_ATTR_UNUSED nelmts,
                 H5S_t H5_ATTR_UNUSED *file_space, H5S_t H5_ATTR_UNUSED *mem_space, H5D_chunk_map_t *fm)
 {
-    H5SL_node_t * chunk_node;                    /* Current node in chunk skip list */
-    H5D_io_info_t nonexistent_io_info;           /* "nonexistent" I/O info object */
-    H5D_io_info_t ctg_io_info;                   /* Contiguous I/O info object */
-    H5D_storage_t ctg_store;                     /* Chunk storage information as contiguous dataset */
-    H5D_io_info_t cpt_io_info;                   /* Compact I/O info object */
-    H5D_storage_t cpt_store;                     /* Chunk storage information as compact dataset */
-    hbool_t       cpt_dirty;                     /* Temporary placeholder for compact storage "dirty" flag */
-    uint32_t      src_accessed_bytes  = 0;       /* Total accessed size in a chunk */
-    hbool_t       skip_missing_chunks = FALSE;   /* Whether to skip missing chunks */
-    herr_t        ret_value           = SUCCEED; /*return value        */
+    H5SL_node_t * chunk_node;                  /* Current node in chunk skip list */
+    H5D_io_info_t nonexistent_io_info;         /* "nonexistent" I/O info object */
+    uint32_t      src_accessed_bytes  = 0;     /* Total accessed size in a chunk */
+    hbool_t       skip_missing_chunks = FALSE; /* Whether to skip missing chunks */
+    H5S_t **      chunk_mem_spaces    = NULL;  /* Array of chunk memory spaces */
+    H5S_t *       chunk_mem_spaces_static[8];  /* Static buffer for chunk_mem_spaces */
+    H5S_t **      chunk_file_spaces = NULL;    /* Array of chunk file spaces */
+    H5S_t *       chunk_file_spaces_static[8]; /* Static buffer for chunk_file_spaces */
+    haddr_t *     chunk_addrs = NULL;          /* Array of chunk addresses */
+    haddr_t       chunk_addrs_static[8];       /* Static buffer for chunk_addrs */
+    herr_t        ret_value = SUCCEED;         /*return value        */
 
     FUNC_ENTER_STATIC
 
@@ -2497,23 +2579,6 @@ H5D__chunk_read(H5D_io_info_t *io_info, const H5D_type_info_t *type_info, hsize_
     H5MM_memcpy(&nonexistent_io_info, io_info, sizeof(nonexistent_io_info));
     nonexistent_io_info.layout_ops = *H5D_LOPS_NONEXISTENT;
 
-    /* Set up contiguous I/O info object */
-    H5MM_memcpy(&ctg_io_info, io_info, sizeof(ctg_io_info));
-    ctg_io_info.store      = &ctg_store;
-    ctg_io_info.layout_ops = *H5D_LOPS_CONTIG;
-
-    /* Initialize temporary contiguous storage info */
-    H5_CHECKED_ASSIGN(ctg_store.contig.dset_size, hsize_t, io_info->dset->shared->layout.u.chunk.size,
-                      uint32_t);
-
-    /* Set up compact I/O info object */
-    H5MM_memcpy(&cpt_io_info, io_info, sizeof(cpt_io_info));
-    cpt_io_info.store      = &cpt_store;
-    cpt_io_info.layout_ops = *H5D_LOPS_COMPACT;
-
-    /* Initialize temporary compact storage info */
-    cpt_store.compact.dirty = &cpt_dirty;
-
     {
         const H5O_fill_t *fill = &(io_info->dset->shared->dcpl_cache.fill); /* Fill value info */
         H5D_fill_value_t  fill_status;                                      /* Fill value status */
@@ -2531,80 +2596,215 @@ H5D__chunk_read(H5D_io_info_t *io_info, const H5D_type_info_t *type_info, hsize_
             skip_missing_chunks = TRUE;
     }
 
-    /* Iterate through nodes in chunk skip list */
-    chunk_node = H5D_CHUNK_GET_FIRST_NODE(fm);
-    while (chunk_node) {
-        H5D_chunk_info_t *chunk_info; /* Chunk information */
-        H5D_chunk_ud_t    udata;      /* Chunk index pass-through    */
+    /* Different blocks depending on whether we're using selection I/O */
+    if (io_info->use_select_io) {
+        size_t num_chunks;
+        size_t element_sizes[2] = {type_info->dst_type_size, 0};
+        void * bufs[2]          = {io_info->u.rbuf, NULL};
+
+        /* Cache number of chunks */
+        num_chunks = H5D_CHUNK_GET_NODE_COUNT(fm);
+
+        /* Allocate arrays of dataspaces and offsets for use with selection I/O,
+         * or point to static buffers */
+        HDassert(sizeof(chunk_mem_spaces_static) / sizeof(chunk_mem_spaces_static[0]) ==
+                 sizeof(chunk_file_spaces_static) / sizeof(chunk_file_spaces_static[0]));
+        HDassert(sizeof(chunk_mem_spaces_static) / sizeof(chunk_mem_spaces_static[0]) ==
+                 sizeof(chunk_addrs_static) / sizeof(chunk_addrs_static[0]));
+        if (num_chunks > (sizeof(chunk_mem_spaces_static) / sizeof(chunk_mem_spaces_static[0]))) {
+            if (NULL == (chunk_mem_spaces = H5MM_malloc(num_chunks * sizeof(H5S_t *))))
+                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTALLOC, FAIL,
+                            "memory allocation failed for memory space list")
+            if (NULL == (chunk_file_spaces = H5MM_malloc(num_chunks * sizeof(H5S_t *))))
+                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTALLOC, FAIL, "memory allocation failed for file space list")
+            if (NULL == (chunk_addrs = H5MM_malloc(num_chunks * sizeof(haddr_t))))
+                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTALLOC, FAIL,
+                            "memory allocation failed for chunk address list")
+        } /* end if */
+        else {
+            chunk_mem_spaces  = chunk_mem_spaces_static;
+            chunk_file_spaces = chunk_file_spaces_static;
+            chunk_addrs       = chunk_addrs_static;
+        } /* end else */
 
-        /* Get the actual chunk information from the skip list node */
-        chunk_info = H5D_CHUNK_GET_NODE_INFO(fm, chunk_node);
+        /* Reset num_chunks */
+        num_chunks = 0;
 
-        /* Get the info for the chunk in the file */
-        if (H5D__chunk_lookup(io_info->dset, chunk_info->scaled, &udata) < 0)
-            HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "error looking up chunk address")
+        /* Iterate through nodes in chunk skip list */
+        chunk_node = H5D_CHUNK_GET_FIRST_NODE(fm);
+        while (chunk_node) {
+            H5D_chunk_info_t *chunk_info; /* Chunk information */
+            H5D_chunk_ud_t    udata;      /* Chunk index pass-through    */
 
-        /* Sanity check */
-        HDassert((H5F_addr_defined(udata.chunk_block.offset) && udata.chunk_block.length > 0) ||
-                 (!H5F_addr_defined(udata.chunk_block.offset) && udata.chunk_block.length == 0));
+            /* Get the actual chunk information from the skip list node */
+            chunk_info = H5D_CHUNK_GET_NODE_INFO(fm, chunk_node);
 
-        /* Check for non-existent chunk & skip it if appropriate */
-        if (H5F_addr_defined(udata.chunk_block.offset) || UINT_MAX != udata.idx_hint ||
-            !skip_missing_chunks) {
-            H5D_io_info_t *chk_io_info;  /* Pointer to I/O info object for this chunk */
-            void *         chunk = NULL; /* Pointer to locked chunk buffer */
-            htri_t         cacheable;    /* Whether the chunk is cacheable */
+            /* Get the info for the chunk in the file */
+            if (H5D__chunk_lookup(io_info->dset, chunk_info->scaled, &udata) < 0)
+                HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "error looking up chunk address")
 
-            /* Set chunk's [scaled] coordinates */
-            io_info->store->chunk.scaled = chunk_info->scaled;
+            /* There should be no chunks cached */
+            HDassert(UINT_MAX == udata.idx_hint);
 
-            /* Determine if we should use the chunk cache */
-            if ((cacheable = H5D__chunk_cacheable(io_info, udata.chunk_block.offset, FALSE)) < 0)
-                HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "can't tell if chunk is cacheable")
-            if (cacheable) {
-                /* Load the chunk into cache and lock it. */
+            /* Sanity check */
+            HDassert((H5F_addr_defined(udata.chunk_block.offset) && udata.chunk_block.length > 0) ||
+                     (!H5F_addr_defined(udata.chunk_block.offset) && udata.chunk_block.length == 0));
+
+            /* Check for non-existent chunk & skip it if appropriate */
+            if (H5F_addr_defined(udata.chunk_block.offset)) {
+                /* Add chunk to list for selection I/O */
+                chunk_mem_spaces[num_chunks]  = chunk_info->mspace;
+                chunk_file_spaces[num_chunks] = chunk_info->fspace;
+                chunk_addrs[num_chunks]       = udata.chunk_block.offset;
+                num_chunks++;
+            } /* end if */
+            else if (!skip_missing_chunks) {
+                /* Perform the actual read operation from the nonexistent chunk
+                 */
+                if ((io_info->io_ops.single_read)(&nonexistent_io_info, type_info,
+                                                  (hsize_t)chunk_info->chunk_points, chunk_info->fspace,
+                                                  chunk_info->mspace) < 0)
+                    HGOTO_ERROR(H5E_DATASET, H5E_READERROR, FAIL, "chunked read failed")
+            } /* end if */
 
-                /* Compute # of bytes accessed in chunk */
-                H5_CHECK_OVERFLOW(type_info->src_type_size, /*From:*/ size_t, /*To:*/ uint32_t);
-                src_accessed_bytes = chunk_info->chunk_points * (uint32_t)type_info->src_type_size;
+            /* Advance to next chunk in list */
+            chunk_node = H5D_CHUNK_GET_NEXT_NODE(fm, chunk_node);
+        } /* end while */
 
-                /* Lock the chunk into the cache */
-                if (NULL == (chunk = H5D__chunk_lock(io_info, &udata, FALSE, FALSE)))
-                    HGOTO_ERROR(H5E_IO, H5E_READERROR, FAIL, "unable to read raw data chunk")
+        /* Issue selection I/O call (we can skip the page buffer because we've
+         * already verified it won't be used, and the metadata accumulator
+         * because this is raw data) */
+        if (H5F_shared_select_read(H5F_SHARED(io_info->dset->oloc.file), H5FD_MEM_DRAW, (uint32_t)num_chunks,
+                                   chunk_mem_spaces, chunk_file_spaces, chunk_addrs, element_sizes, bufs) < 0)
+            HGOTO_ERROR(H5E_DATASET, H5E_READERROR, FAIL, "chunk selection read failed")
+
+        /* Clean up memory */
+        if (chunk_mem_spaces != chunk_mem_spaces_static) {
+            HDassert(chunk_mem_spaces);
+            HDassert(chunk_file_spaces != chunk_file_spaces_static);
+            HDassert(chunk_addrs != chunk_addrs_static);
+            H5MM_free(chunk_mem_spaces);
+            chunk_mem_spaces = NULL;
+            H5MM_free(chunk_file_spaces);
+            chunk_file_spaces = NULL;
+            H5MM_free(chunk_addrs);
+            chunk_addrs = NULL;
+        } /* end if */
+    }     /* end if */
+    else {
+        H5D_io_info_t ctg_io_info; /* Contiguous I/O info object */
+        H5D_storage_t ctg_store;   /* Chunk storage information as contiguous dataset */
+        H5D_io_info_t cpt_io_info; /* Compact I/O info object */
+        H5D_storage_t cpt_store;   /* Chunk storage information as compact dataset */
+        hbool_t       cpt_dirty;   /* Temporary placeholder for compact storage "dirty" flag */
+
+        /* Set up contiguous I/O info object */
+        H5MM_memcpy(&ctg_io_info, io_info, sizeof(ctg_io_info));
+        ctg_io_info.store      = &ctg_store;
+        ctg_io_info.layout_ops = *H5D_LOPS_CONTIG;
+
+        /* Initialize temporary contiguous storage info */
+        H5_CHECKED_ASSIGN(ctg_store.contig.dset_size, hsize_t, io_info->dset->shared->layout.u.chunk.size,
+                          uint32_t);
+
+        /* Set up compact I/O info object */
+        H5MM_memcpy(&cpt_io_info, io_info, sizeof(cpt_io_info));
+        cpt_io_info.store      = &cpt_store;
+        cpt_io_info.layout_ops = *H5D_LOPS_COMPACT;
+
+        /* Initialize temporary compact storage info */
+        cpt_store.compact.dirty = &cpt_dirty;
+
+        /* Iterate through nodes in chunk skip list */
+        chunk_node = H5D_CHUNK_GET_FIRST_NODE(fm);
+        while (chunk_node) {
+            H5D_chunk_info_t *chunk_info; /* Chunk information */
+            H5D_chunk_ud_t    udata;      /* Chunk index pass-through    */
+            htri_t            cacheable;  /* Whether the chunk is cacheable */
+
+            /* Get the actual chunk information from the skip list node */
+            chunk_info = H5D_CHUNK_GET_NODE_INFO(fm, chunk_node);
+
+            /* Get the info for the chunk in the file */
+            if (H5D__chunk_lookup(io_info->dset, chunk_info->scaled, &udata) < 0)
+                HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "error looking up chunk address")
 
-                /* Set up the storage buffer information for this chunk */
-                cpt_store.compact.buf = chunk;
+            /* Sanity check */
+            HDassert((H5F_addr_defined(udata.chunk_block.offset) && udata.chunk_block.length > 0) ||
+                     (!H5F_addr_defined(udata.chunk_block.offset) && udata.chunk_block.length == 0));
 
-                /* Point I/O info at contiguous I/O info for this chunk */
-                chk_io_info = &cpt_io_info;
-            } /* end if */
-            else if (H5F_addr_defined(udata.chunk_block.offset)) {
-                /* Set up the storage address information for this chunk */
-                ctg_store.contig.dset_addr = udata.chunk_block.offset;
+            /* Check for non-existent chunk & skip it if appropriate */
+            if (H5F_addr_defined(udata.chunk_block.offset) || UINT_MAX != udata.idx_hint ||
+                !skip_missing_chunks) {
+                H5D_io_info_t *chk_io_info;  /* Pointer to I/O info object for this chunk */
+                void *         chunk = NULL; /* Pointer to locked chunk buffer */
 
-                /* Point I/O info at temporary I/O info for this chunk */
-                chk_io_info = &ctg_io_info;
-            } /* end else if */
-            else {
-                /* Point I/O info at "nonexistent" I/O info for this chunk */
-                chk_io_info = &nonexistent_io_info;
-            } /* end else */
+                /* Set chunk's [scaled] coordinates */
+                io_info->store->chunk.scaled = chunk_info->scaled;
 
-            /* Perform the actual read operation */
-            if ((io_info->io_ops.single_read)(chk_io_info, type_info, (hsize_t)chunk_info->chunk_points,
-                                              chunk_info->fspace, chunk_info->mspace) < 0)
-                HGOTO_ERROR(H5E_DATASET, H5E_READERROR, FAIL, "chunked read failed")
+                /* Determine if we should use the chunk cache */
+                if ((cacheable = H5D__chunk_cacheable(io_info, udata.chunk_block.offset, FALSE)) < 0)
+                    HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "can't tell if chunk is cacheable")
+                if (cacheable) {
+                    /* Load the chunk into cache and lock it. */
 
-            /* Release the cache lock on the chunk. */
-            if (chunk && H5D__chunk_unlock(io_info, &udata, FALSE, chunk, src_accessed_bytes) < 0)
-                HGOTO_ERROR(H5E_IO, H5E_READERROR, FAIL, "unable to unlock raw data chunk")
-        } /* end if */
+                    /* Compute # of bytes accessed in chunk */
+                    H5_CHECK_OVERFLOW(type_info->src_type_size, /*From:*/ size_t, /*To:*/ uint32_t);
+                    src_accessed_bytes = chunk_info->chunk_points * (uint32_t)type_info->src_type_size;
 
-        /* Advance to next chunk in list */
-        chunk_node = H5D_CHUNK_GET_NEXT_NODE(fm, chunk_node);
-    } /* end while */
+                    /* Lock the chunk into the cache */
+                    if (NULL == (chunk = H5D__chunk_lock(io_info, &udata, FALSE, FALSE)))
+                        HGOTO_ERROR(H5E_IO, H5E_READERROR, FAIL, "unable to read raw data chunk")
+
+                    /* Set up the storage buffer information for this chunk */
+                    cpt_store.compact.buf = chunk;
+
+                    /* Point I/O info at contiguous I/O info for this chunk */
+                    chk_io_info = &cpt_io_info;
+                } /* end if */
+                else if (H5F_addr_defined(udata.chunk_block.offset)) {
+                    /* Set up the storage address information for this chunk */
+                    ctg_store.contig.dset_addr = udata.chunk_block.offset;
+
+                    /* Point I/O info at temporary I/O info for this chunk */
+                    chk_io_info = &ctg_io_info;
+                } /* end else if */
+                else {
+                    /* Point I/O info at "nonexistent" I/O info for this chunk */
+                    chk_io_info = &nonexistent_io_info;
+                } /* end else */
+
+                /* Perform the actual read operation */
+                if ((io_info->io_ops.single_read)(chk_io_info, type_info, (hsize_t)chunk_info->chunk_points,
+                                                  chunk_info->fspace, chunk_info->mspace) < 0)
+                    HGOTO_ERROR(H5E_DATASET, H5E_READERROR, FAIL, "chunked read failed")
+
+                /* Release the cache lock on the chunk. */
+                if (chunk && H5D__chunk_unlock(io_info, &udata, FALSE, chunk, src_accessed_bytes) < 0)
+                    HGOTO_ERROR(H5E_IO, H5E_READERROR, FAIL, "unable to unlock raw data chunk")
+            } /* end if */
+
+            /* Advance to next chunk in list */
+            chunk_node = H5D_CHUNK_GET_NEXT_NODE(fm, chunk_node);
+        } /* end while */
+    }     /* end else */
 
 done:
+    /* Cleanup on failure */
+    if (ret_value < 0) {
+        if (chunk_mem_spaces != chunk_mem_spaces_static)
+            chunk_mem_spaces = H5MM_xfree(chunk_mem_spaces);
+        if (chunk_file_spaces != chunk_file_spaces_static)
+            chunk_file_spaces = H5MM_xfree(chunk_file_spaces);
+        if (chunk_addrs != chunk_addrs_static)
+            chunk_addrs = H5MM_xfree(chunk_addrs);
+    } /* end if */
+
+    /* Make sure we cleaned up */
+    HDassert(!chunk_mem_spaces || chunk_mem_spaces == chunk_mem_spaces_static);
+    HDassert(!chunk_file_spaces || chunk_file_spaces == chunk_file_spaces_static);
+    HDassert(!chunk_addrs || chunk_addrs == chunk_addrs_static);
+
     FUNC_LEAVE_NOAPI(ret_value)
 } /* H5D__chunk_read() */
 
@@ -2624,14 +2824,20 @@ static herr_t
 H5D__chunk_write(H5D_io_info_t *io_info, const H5D_type_info_t *type_info, hsize_t H5_ATTR_UNUSED nelmts,
                  H5S_t H5_ATTR_UNUSED *file_space, H5S_t H5_ATTR_UNUSED *mem_space, H5D_chunk_map_t *fm)
 {
-    H5SL_node_t * chunk_node;                   /* Current node in chunk skip list */
-    H5D_io_info_t ctg_io_info;                  /* Contiguous I/O info object */
-    H5D_storage_t ctg_store;                    /* Chunk storage information as contiguous dataset */
-    H5D_io_info_t cpt_io_info;                  /* Compact I/O info object */
-    H5D_storage_t cpt_store;                    /* Chunk storage information as compact dataset */
-    hbool_t       cpt_dirty;                    /* Temporary placeholder for compact storage "dirty" flag */
-    uint32_t      dst_accessed_bytes = 0;       /* Total accessed size in a chunk */
-    herr_t        ret_value          = SUCCEED; /* Return value        */
+    H5SL_node_t * chunk_node;                  /* Current node in chunk skip list */
+    H5D_io_info_t ctg_io_info;                 /* Contiguous I/O info object */
+    H5D_storage_t ctg_store;                   /* Chunk storage information as contiguous dataset */
+    H5D_io_info_t cpt_io_info;                 /* Compact I/O info object */
+    H5D_storage_t cpt_store;                   /* Chunk storage information as compact dataset */
+    hbool_t       cpt_dirty;                   /* Temporary placeholder for compact storage "dirty" flag */
+    uint32_t      dst_accessed_bytes = 0;      /* Total accessed size in a chunk */
+    H5S_t **      chunk_mem_spaces   = NULL;   /* Array of chunk memory spaces */
+    H5S_t *       chunk_mem_spaces_static[8];  /* Static buffer for chunk_mem_spaces */
+    H5S_t **      chunk_file_spaces = NULL;    /* Array of chunk file spaces */
+    H5S_t *       chunk_file_spaces_static[8]; /* Static buffer for chunk_file_spaces */
+    haddr_t *     chunk_addrs = NULL;          /* Array of chunk addresses */
+    haddr_t       chunk_addrs_static[8];       /* Static buffer for chunk_addrs */
+    herr_t        ret_value = SUCCEED;         /* Return value        */
 
     FUNC_ENTER_STATIC
 
@@ -2658,116 +2864,295 @@ H5D__chunk_write(H5D_io_info_t *io_info, const H5D_type_info_t *type_info, hsize
     /* Initialize temporary compact storage info */
     cpt_store.compact.dirty = &cpt_dirty;
 
-    /* Iterate through nodes in chunk skip list */
-    chunk_node = H5D_CHUNK_GET_FIRST_NODE(fm);
-    while (chunk_node) {
-        H5D_chunk_info_t * chunk_info;          /* Chunk information */
-        H5D_chk_idx_info_t idx_info;            /* Chunked index info */
-        H5D_io_info_t *    chk_io_info;         /* Pointer to I/O info object for this chunk */
-        void *             chunk;               /* Pointer to locked chunk buffer */
-        H5D_chunk_ud_t     udata;               /* Index pass-through    */
-        htri_t             cacheable;           /* Whether the chunk is cacheable */
-        hbool_t            need_insert = FALSE; /* Whether the chunk needs to be inserted into the index */
+    /* Different blocks depending on whether we're using selection I/O */
+    if (io_info->use_select_io) {
+        size_t      num_chunks;
+        size_t      element_sizes[2] = {type_info->dst_type_size, 0};
+        const void *bufs[2]          = {io_info->u.wbuf, NULL};
+
+        /* Cache number of chunks */
+        num_chunks = H5D_CHUNK_GET_NODE_COUNT(fm);
+
+        /* Allocate arrays of dataspaces and offsets for use with selection I/O,
+         * or point to static buffers */
+        HDassert(sizeof(chunk_mem_spaces_static) / sizeof(chunk_mem_spaces_static[0]) ==
+                 sizeof(chunk_file_spaces_static) / sizeof(chunk_file_spaces_static[0]));
+        HDassert(sizeof(chunk_mem_spaces_static) / sizeof(chunk_mem_spaces_static[0]) ==
+                 sizeof(chunk_addrs_static) / sizeof(chunk_addrs_static[0]));
+        if (num_chunks > (sizeof(chunk_mem_spaces_static) / sizeof(chunk_mem_spaces_static[0]))) {
+            if (NULL == (chunk_mem_spaces = H5MM_malloc(num_chunks * sizeof(H5S_t *))))
+                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTALLOC, FAIL,
+                            "memory allocation failed for memory space list")
+            if (NULL == (chunk_file_spaces = H5MM_malloc(num_chunks * sizeof(H5S_t *))))
+                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTALLOC, FAIL, "memory allocation failed for file space list")
+            if (NULL == (chunk_addrs = H5MM_malloc(num_chunks * sizeof(haddr_t))))
+                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTALLOC, FAIL,
+                            "memory allocation failed for chunk address list")
+        } /* end if */
+        else {
+            chunk_mem_spaces  = chunk_mem_spaces_static;
+            chunk_file_spaces = chunk_file_spaces_static;
+            chunk_addrs       = chunk_addrs_static;
+        } /* end else */
 
-        /* Get the actual chunk information from the skip list node */
-        chunk_info = H5D_CHUNK_GET_NODE_INFO(fm, chunk_node);
+        /* Reset num_chunks */
+        num_chunks = 0;
 
-        /* Look up the chunk */
-        if (H5D__chunk_lookup(io_info->dset, chunk_info->scaled, &udata) < 0)
-            HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "error looking up chunk address")
+        /* Iterate through nodes in chunk skip list */
+        chunk_node = H5D_CHUNK_GET_FIRST_NODE(fm);
+        while (chunk_node) {
+            H5D_chunk_info_t * chunk_info; /* Chunk information */
+            H5D_chk_idx_info_t idx_info;   /* Chunked index info */
+            H5D_chunk_ud_t     udata;      /* Index pass-through    */
+            htri_t             cacheable;  /* Whether the chunk is cacheable */
+            hbool_t need_insert = FALSE;   /* Whether the chunk needs to be inserted into the index */
 
-        /* Sanity check */
-        HDassert((H5F_addr_defined(udata.chunk_block.offset) && udata.chunk_block.length > 0) ||
-                 (!H5F_addr_defined(udata.chunk_block.offset) && udata.chunk_block.length == 0));
-
-        /* Set chunk's [scaled] coordinates */
-        io_info->store->chunk.scaled = chunk_info->scaled;
-
-        /* Determine if we should use the chunk cache */
-        if ((cacheable = H5D__chunk_cacheable(io_info, udata.chunk_block.offset, TRUE)) < 0)
-            HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "can't tell if chunk is cacheable")
-        if (cacheable) {
-            /* Load the chunk into cache.  But if the whole chunk is written,
-             * simply allocate space instead of load the chunk. */
-            hbool_t entire_chunk = TRUE; /* Whether whole chunk is selected */
-
-            /* Compute # of bytes accessed in chunk */
-            H5_CHECK_OVERFLOW(type_info->dst_type_size, /*From:*/ size_t, /*To:*/ uint32_t);
-            dst_accessed_bytes = chunk_info->chunk_points * (uint32_t)type_info->dst_type_size;
-
-            /* Determine if we will access all the data in the chunk */
-            if (dst_accessed_bytes != ctg_store.contig.dset_size ||
-                (chunk_info->chunk_points * type_info->src_type_size) != ctg_store.contig.dset_size ||
-                fm->fsel_type == H5S_SEL_POINTS)
-                entire_chunk = FALSE;
-
-            /* Lock the chunk into the cache */
-            if (NULL == (chunk = H5D__chunk_lock(io_info, &udata, entire_chunk, FALSE)))
-                HGOTO_ERROR(H5E_IO, H5E_READERROR, FAIL, "unable to read raw data chunk")
-
-            /* Set up the storage buffer information for this chunk */
-            cpt_store.compact.buf = chunk;
-
-            /* Point I/O info at main I/O info for this chunk */
-            chk_io_info = &cpt_io_info;
+            /* Get the actual chunk information from the skip list node */
+            chunk_info = H5D_CHUNK_GET_NODE_INFO(fm, chunk_node);
+
+            /* Get the info for the chunk in the file */
+            if (H5D__chunk_lookup(io_info->dset, chunk_info->scaled, &udata) < 0)
+                HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "error looking up chunk address")
+
+            /* There should be no chunks cached */
+            HDassert(UINT_MAX == udata.idx_hint);
+
+            /* Sanity check */
+            HDassert((H5F_addr_defined(udata.chunk_block.offset) && udata.chunk_block.length > 0) ||
+                     (!H5F_addr_defined(udata.chunk_block.offset) && udata.chunk_block.length == 0));
+
+            /* Set chunk's [scaled] coordinates */
+            io_info->store->chunk.scaled = chunk_info->scaled;
+
+            /* Determine if we should use the chunk cache */
+            if ((cacheable = H5D__chunk_cacheable(io_info, udata.chunk_block.offset, TRUE)) < 0)
+                HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "can't tell if chunk is cacheable")
+            if (cacheable) {
+                /* Load the chunk into cache.  But if the whole chunk is written,
+                 * simply allocate space instead of load the chunk. */
+                void *  chunk;               /* Pointer to locked chunk buffer */
+                hbool_t entire_chunk = TRUE; /* Whether whole chunk is selected */
+
+                /* Compute # of bytes accessed in chunk */
+                H5_CHECK_OVERFLOW(type_info->dst_type_size, /*From:*/ size_t, /*To:*/ uint32_t);
+                dst_accessed_bytes = chunk_info->chunk_points * (uint32_t)type_info->dst_type_size;
+
+                /* Determine if we will access all the data in the chunk */
+                if (dst_accessed_bytes != ctg_store.contig.dset_size ||
+                    (chunk_info->chunk_points * type_info->src_type_size) != ctg_store.contig.dset_size ||
+                    fm->fsel_type == H5S_SEL_POINTS)
+                    entire_chunk = FALSE;
+
+                /* Lock the chunk into the cache */
+                if (NULL == (chunk = H5D__chunk_lock(io_info, &udata, entire_chunk, FALSE)))
+                    HGOTO_ERROR(H5E_IO, H5E_READERROR, FAIL, "unable to read raw data chunk")
+
+                /* Set up the storage buffer information for this chunk */
+                cpt_store.compact.buf = chunk;
+
+                /* Perform the actual write operation */
+                if ((io_info->io_ops.single_write)(&cpt_io_info, type_info, (hsize_t)chunk_info->chunk_points,
+                                                   chunk_info->fspace, chunk_info->mspace) < 0)
+                    HGOTO_ERROR(H5E_DATASET, H5E_READERROR, FAIL, "chunked write failed")
+
+                /* Release the cache lock on the chunk */
+                if (H5D__chunk_unlock(io_info, &udata, TRUE, chunk, dst_accessed_bytes) < 0)
+                    HGOTO_ERROR(H5E_IO, H5E_READERROR, FAIL, "unable to unlock raw data chunk")
+            } /* end if */
+            else {
+                /* If the chunk hasn't been allocated on disk, do so now. */
+                if (!H5F_addr_defined(udata.chunk_block.offset)) {
+                    /* Compose chunked index info struct */
+                    idx_info.f       = io_info->dset->oloc.file;
+                    idx_info.pline   = &(io_info->dset->shared->dcpl_cache.pline);
+                    idx_info.layout  = &(io_info->dset->shared->layout.u.chunk);
+                    idx_info.storage = &(io_info->dset->shared->layout.storage.u.chunk);
+
+                    /* Set up the size of chunk for user data */
+                    udata.chunk_block.length = io_info->dset->shared->layout.u.chunk.size;
+
+                    /* Allocate the chunk */
+                    if (H5D__chunk_file_alloc(&idx_info, NULL, &udata.chunk_block, &need_insert,
+                                              chunk_info->scaled) < 0)
+                        HGOTO_ERROR(H5E_DATASET, H5E_CANTINSERT, FAIL,
+                                    "unable to insert/resize chunk on chunk level")
+
+                    /* Make sure the address of the chunk is returned. */
+                    if (!H5F_addr_defined(udata.chunk_block.offset))
+                        HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "chunk address isn't defined")
+
+                    /* Cache the new chunk information */
+                    H5D__chunk_cinfo_cache_update(&io_info->dset->shared->cache.chunk.last, &udata);
+
+                    /* Insert chunk into index */
+                    if (need_insert && io_info->dset->shared->layout.storage.u.chunk.ops->insert)
+                        if ((io_info->dset->shared->layout.storage.u.chunk.ops->insert)(&idx_info, &udata,
+                                                                                        NULL) < 0)
+                            HGOTO_ERROR(H5E_DATASET, H5E_CANTINSERT, FAIL,
+                                        "unable to insert chunk addr into index")
+                } /* end if */
+
+                /* Add chunk to list for selection I/O */
+                chunk_mem_spaces[num_chunks]  = chunk_info->mspace;
+                chunk_file_spaces[num_chunks] = chunk_info->fspace;
+                chunk_addrs[num_chunks]       = udata.chunk_block.offset;
+                num_chunks++;
+            } /* end else */
+
+            /* Advance to next chunk in list */
+            chunk_node = H5D_CHUNK_GET_NEXT_NODE(fm, chunk_node);
+        } /* end while */
+
+        /* Issue selection I/O call (we can skip the page buffer because we've
+         * already verified it won't be used, and the metadata accumulator
+         * because this is raw data) */
+        if (H5F_shared_select_write(H5F_SHARED(io_info->dset->oloc.file), H5FD_MEM_DRAW, (uint32_t)num_chunks,
+                                    chunk_mem_spaces, chunk_file_spaces, chunk_addrs, element_sizes,
+                                    bufs) < 0)
+            HGOTO_ERROR(H5E_DATASET, H5E_READERROR, FAIL, "chunk selection read failed")
+
+        /* Clean up memory */
+        if (chunk_mem_spaces != chunk_mem_spaces_static) {
+            HDassert(chunk_mem_spaces);
+            HDassert(chunk_file_spaces != chunk_file_spaces_static);
+            HDassert(chunk_addrs != chunk_addrs_static);
+            H5MM_free(chunk_mem_spaces);
+            chunk_mem_spaces = NULL;
+            H5MM_free(chunk_file_spaces);
+            chunk_file_spaces = NULL;
+            H5MM_free(chunk_addrs);
+            chunk_addrs = NULL;
         } /* end if */
-        else {
-            /* If the chunk hasn't been allocated on disk, do so now. */
-            if (!H5F_addr_defined(udata.chunk_block.offset)) {
-                /* Compose chunked index info struct */
-                idx_info.f       = io_info->dset->oloc.file;
-                idx_info.pline   = &(io_info->dset->shared->dcpl_cache.pline);
-                idx_info.layout  = &(io_info->dset->shared->layout.u.chunk);
-                idx_info.storage = &(io_info->dset->shared->layout.storage.u.chunk);
-
-                /* Set up the size of chunk for user data */
-                udata.chunk_block.length = io_info->dset->shared->layout.u.chunk.size;
-
-                /* Allocate the chunk */
-                if (H5D__chunk_file_alloc(&idx_info, NULL, &udata.chunk_block, &need_insert,
-                                          chunk_info->scaled) < 0)
-                    HGOTO_ERROR(H5E_DATASET, H5E_CANTINSERT, FAIL,
-                                "unable to insert/resize chunk on chunk level")
-
-                /* Make sure the address of the chunk is returned. */
-                if (!H5F_addr_defined(udata.chunk_block.offset))
-                    HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "chunk address isn't defined")
-
-                /* Cache the new chunk information */
-                H5D__chunk_cinfo_cache_update(&io_info->dset->shared->cache.chunk.last, &udata);
+    }     /* end if */
+    else {
+        /* Iterate through nodes in chunk skip list */
+        chunk_node = H5D_CHUNK_GET_FIRST_NODE(fm);
+        while (chunk_node) {
+            H5D_chunk_info_t * chunk_info;  /* Chunk information */
+            H5D_chk_idx_info_t idx_info;    /* Chunked index info */
+            H5D_io_info_t *    chk_io_info; /* Pointer to I/O info object for this chunk */
+            void *             chunk;       /* Pointer to locked chunk buffer */
+            H5D_chunk_ud_t     udata;       /* Index pass-through    */
+            htri_t             cacheable;   /* Whether the chunk is cacheable */
+            hbool_t need_insert = FALSE;    /* Whether the chunk needs to be inserted into the index */
+
+            /* Get the actual chunk information from the skip list node */
+            chunk_info = H5D_CHUNK_GET_NODE_INFO(fm, chunk_node);
+
+            /* Look up the chunk */
+            if (H5D__chunk_lookup(io_info->dset, chunk_info->scaled, &udata) < 0)
+                HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "error looking up chunk address")
+
+            /* Sanity check */
+            HDassert((H5F_addr_defined(udata.chunk_block.offset) && udata.chunk_block.length > 0) ||
+                     (!H5F_addr_defined(udata.chunk_block.offset) && udata.chunk_block.length == 0));
+
+            /* Set chunk's [scaled] coordinates */
+            io_info->store->chunk.scaled = chunk_info->scaled;
+
+            /* Determine if we should use the chunk cache */
+            if ((cacheable = H5D__chunk_cacheable(io_info, udata.chunk_block.offset, TRUE)) < 0)
+                HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "can't tell if chunk is cacheable")
+            if (cacheable) {
+                /* Load the chunk into cache.  But if the whole chunk is written,
+                 * simply allocate space instead of load the chunk. */
+                hbool_t entire_chunk = TRUE; /* Whether whole chunk is selected */
+
+                /* Compute # of bytes accessed in chunk */
+                H5_CHECK_OVERFLOW(type_info->dst_type_size, /*From:*/ size_t, /*To:*/ uint32_t);
+                dst_accessed_bytes = chunk_info->chunk_points * (uint32_t)type_info->dst_type_size;
+
+                /* Determine if we will access all the data in the chunk */
+                if (dst_accessed_bytes != ctg_store.contig.dset_size ||
+                    (chunk_info->chunk_points * type_info->src_type_size) != ctg_store.contig.dset_size ||
+                    fm->fsel_type == H5S_SEL_POINTS)
+                    entire_chunk = FALSE;
+
+                /* Lock the chunk into the cache */
+                if (NULL == (chunk = H5D__chunk_lock(io_info, &udata, entire_chunk, FALSE)))
+                    HGOTO_ERROR(H5E_IO, H5E_READERROR, FAIL, "unable to read raw data chunk")
+
+                /* Set up the storage buffer information for this chunk */
+                cpt_store.compact.buf = chunk;
+
+                /* Point I/O info at main I/O info for this chunk */
+                chk_io_info = &cpt_io_info;
             } /* end if */
+            else {
+                /* If the chunk hasn't been allocated on disk, do so now. */
+                if (!H5F_addr_defined(udata.chunk_block.offset)) {
+                    /* Compose chunked index info struct */
+                    idx_info.f       = io_info->dset->oloc.file;
+                    idx_info.pline   = &(io_info->dset->shared->dcpl_cache.pline);
+                    idx_info.layout  = &(io_info->dset->shared->layout.u.chunk);
+                    idx_info.storage = &(io_info->dset->shared->layout.storage.u.chunk);
+
+                    /* Set up the size of chunk for user data */
+                    udata.chunk_block.length = io_info->dset->shared->layout.u.chunk.size;
+
+                    /* Allocate the chunk */
+                    if (H5D__chunk_file_alloc(&idx_info, NULL, &udata.chunk_block, &need_insert,
+                                              chunk_info->scaled) < 0)
+                        HGOTO_ERROR(H5E_DATASET, H5E_CANTINSERT, FAIL,
+                                    "unable to insert/resize chunk on chunk level")
+
+                    /* Make sure the address of the chunk is returned. */
+                    if (!H5F_addr_defined(udata.chunk_block.offset))
+                        HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "chunk address isn't defined")
+
+                    /* Cache the new chunk information */
+                    H5D__chunk_cinfo_cache_update(&io_info->dset->shared->cache.chunk.last, &udata);
+                } /* end if */
 
-            /* Set up the storage address information for this chunk */
-            ctg_store.contig.dset_addr = udata.chunk_block.offset;
+                /* Set up the storage address information for this chunk */
+                ctg_store.contig.dset_addr = udata.chunk_block.offset;
 
-            /* No chunk cached */
-            chunk = NULL;
+                /* No chunk cached */
+                chunk = NULL;
 
-            /* Point I/O info at temporary I/O info for this chunk */
-            chk_io_info = &ctg_io_info;
-        } /* end else */
+                /* Point I/O info at temporary I/O info for this chunk */
+                chk_io_info = &ctg_io_info;
+            } /* end else */
 
-        /* Perform the actual write operation */
-        if ((io_info->io_ops.single_write)(chk_io_info, type_info, (hsize_t)chunk_info->chunk_points,
-                                           chunk_info->fspace, chunk_info->mspace) < 0)
-            HGOTO_ERROR(H5E_DATASET, H5E_READERROR, FAIL, "chunked write failed")
+            /* Perform the actual write operation */
+            if ((io_info->io_ops.single_write)(chk_io_info, type_info, (hsize_t)chunk_info->chunk_points,
+                                               chunk_info->fspace, chunk_info->mspace) < 0)
+                HGOTO_ERROR(H5E_DATASET, H5E_READERROR, FAIL, "chunked write failed")
 
-        /* Release the cache lock on the chunk, or insert chunk into index. */
-        if (chunk) {
-            if (H5D__chunk_unlock(io_info, &udata, TRUE, chunk, dst_accessed_bytes) < 0)
-                HGOTO_ERROR(H5E_IO, H5E_READERROR, FAIL, "unable to unlock raw data chunk")
-        } /* end if */
-        else {
-            if (need_insert && io_info->dset->shared->layout.storage.u.chunk.ops->insert)
-                if ((io_info->dset->shared->layout.storage.u.chunk.ops->insert)(&idx_info, &udata, NULL) < 0)
-                    HGOTO_ERROR(H5E_DATASET, H5E_CANTINSERT, FAIL, "unable to insert chunk addr into index")
-        } /* end else */
+            /* Release the cache lock on the chunk, or insert chunk into index. */
+            if (chunk) {
+                if (H5D__chunk_unlock(io_info, &udata, TRUE, chunk, dst_accessed_bytes) < 0)
+                    HGOTO_ERROR(H5E_IO, H5E_READERROR, FAIL, "unable to unlock raw data chunk")
+            } /* end if */
+            else {
+                if (need_insert && io_info->dset->shared->layout.storage.u.chunk.ops->insert)
+                    if ((io_info->dset->shared->layout.storage.u.chunk.ops->insert)(&idx_info, &udata, NULL) <
+                        0)
+                        HGOTO_ERROR(H5E_DATASET, H5E_CANTINSERT, FAIL,
+                                    "unable to insert chunk addr into index")
+            } /* end else */
 
-        /* Advance to next chunk in list */
-        chunk_node = H5D_CHUNK_GET_NEXT_NODE(fm, chunk_node);
-    } /* end while */
+            /* Advance to next chunk in list */
+            chunk_node = H5D_CHUNK_GET_NEXT_NODE(fm, chunk_node);
+        } /* end while */
+    }     /* end else */
 
 done:
+    /* Cleanup on failure */
+    if (ret_value < 0) {
+        if (chunk_mem_spaces != chunk_mem_spaces_static)
+            chunk_mem_spaces = H5MM_xfree(chunk_mem_spaces);
+        if (chunk_file_spaces != chunk_file_spaces_static)
+            chunk_file_spaces = H5MM_xfree(chunk_file_spaces);
+        if (chunk_addrs != chunk_addrs_static)
+            chunk_addrs = H5MM_xfree(chunk_addrs);
+    } /* end if */
+
+    /* Make sure we cleaned up */
+    HDassert(!chunk_mem_spaces || chunk_mem_spaces == chunk_mem_spaces_static);
+    HDassert(!chunk_file_spaces || chunk_file_spaces == chunk_file_spaces_static);
+    HDassert(!chunk_addrs || chunk_addrs == chunk_addrs_static);
+
     FUNC_LEAVE_NOAPI(ret_value)
 } /* H5D__chunk_write() */