[svn-r21789] Purpose: Fix HDFFV-7833

Description:
When shrinking a chunked dataset, the library fills in the unused parts of
chunks that have been shrunk.  The fill value buffer allocated for this purpose
had a maximum size of 1 MB, but the fill was performed in a single operation.
Therefore, if the amount of unused space in a chunk after being shrunk was
greater than 1 MB, the library would read off the end of the fill value buffer.
Changed the maximum fill buffer size to be equal to the chunk size.

Tested: durandal; jam, koala, heiwa (h5committest)

2 files changed, 122 insertions, 1 deletions

diff --git a/src/H5Dchunk.c b/src/H5Dchunk.c
index 092e1b5..6a05f2d 100644
--- a/src/H5Dchunk.c
+++ b/src/H5Dchunk.c
@@ -3476,6 +3476,7 @@ H5D_chunk_prune_fill(H5D_chunk_it_ud1_t *udata)
     H5S_sel_iter_t chunk_iter;          /* Memory selection iteration info */
     hssize_t    sel_nelmts;             /* Number of elements in selection */
     hsize_t     count[H5O_LAYOUT_NDIMS]; /* Element count of hyperslab */
+    size_t      chunk_size;             /*size of a chunk       */
     void        *chunk;	                /* The file chunk  */
     H5D_chunk_ud_t chk_udata;           /* User data for locking chunk */
     uint32_t    bytes_accessed;         /* Bytes accessed in chunk */
@@ -3485,6 +3486,10 @@ H5D_chunk_prune_fill(H5D_chunk_it_ud1_t *udata)
 
     FUNC_ENTER_NOAPI_NOINIT(H5D_chunk_prune_fill)
 
+    /* Get the chunk's size */
+    HDassert(layout->u.chunk.size > 0);
+    H5_ASSIGN_OVERFLOW(chunk_size, layout->u.chunk.size, uint32_t, size_t);
+
     /* Get the info for the chunk in the file */
     if(H5D_chunk_lookup(dset, io_info->dxpl_id, chunk_offset,
             io_info->store->chunk.index, &chk_udata) < 0)
@@ -3501,7 +3506,7 @@ H5D_chunk_prune_fill(H5D_chunk_it_ud1_t *udata)
         if(H5D_fill_init(&udata->fb_info, NULL, NULL, NULL, NULL, NULL,
                 &dset->shared->dcpl_cache.fill,
                 dset->shared->type, dset->shared->type_id, (size_t)udata->elmts_per_chunk,
-                io_info->dxpl_cache->max_temp_buf, io_info->dxpl_id) < 0)
+                chunk_size, io_info->dxpl_id) < 0)
             HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "can't initialize fill buffer info")
         udata->fb_info_init = TRUE;
     } /* end if */
diff --git a/test/dsets.c b/test/dsets.c
index 959ac43..c83518b 100644
--- a/test/dsets.c
+++ b/test/dsets.c
@@ -8066,6 +8066,121 @@ error:
     return -1;
 } /* end test_chunk_expand() */
 
+
+/*-------------------------------------------------------------------------
+ * Function: test_large_chunk_shrink
+ *
+ * Purpose: Tests support for shrinking a chunk larger than 1 MB by a
+ *              size greater than 1 MB.
+ *
+ * Return:      Success: 0
+ *              Failure: -1
+ *
+ * Programmer:  Neil Fortner
+ *              Monday, November 31, 2011
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+test_large_chunk_shrink(hid_t fapl)
+{
+    char        filename[FILENAME_BUF_SIZE];
+    hid_t       fid = -1;       /* File ID */
+    hid_t       dcpl = -1;      /* Dataset creation property list ID */
+    hid_t       sid = -1;       /* Dataspace ID */
+    hid_t       scalar_sid = -1;/* Scalar dataspace ID */
+    hid_t       dsid = -1;      /* Dataset ID */
+    hsize_t     dim, max_dim, chunk_dim; /* Dataset and chunk dimensions */
+    hsize_t     hs_offset;      /* Hyperslab offset */
+    hsize_t     hs_size;        /* Hyperslab size */
+    unsigned    write_elem, read_elem;  /* Element written/read */
+
+    TESTING("shrinking large chunk");
+
+    h5_fixname(FILENAME[10], fapl, filename, sizeof filename);
+
+    /* Create file */
+    if((fid = H5Fcreate(filename, H5F_ACC_TRUNC, H5P_DEFAULT, fapl)) < 0) FAIL_STACK_ERROR
+
+    /* Create dataset creation property list */
+    if((dcpl = H5Pcreate(H5P_DATASET_CREATE)) < 0) FAIL_STACK_ERROR
+
+    /* Set 2 MB chunk size */
+    chunk_dim = 2 * 1024 * 1024 / sizeof(unsigned);
+    if(H5Pset_chunk(dcpl, 1, &chunk_dim) < 0) FAIL_STACK_ERROR
+
+    /* Create scalar dataspace */
+    if((scalar_sid = H5Screate(H5S_SCALAR)) < 0) FAIL_STACK_ERROR
+
+    /* Create 1-D dataspace */
+    dim = 2 * 1024 * 1024 / sizeof(unsigned);
+    max_dim = H5S_UNLIMITED;
+    if((sid = H5Screate_simple(1, &dim, &max_dim)) < 0) FAIL_STACK_ERROR
+
+    /* Create 2 MB chunked dataset */
+    if((dsid = H5Dcreate2(fid, "dset", H5T_NATIVE_UINT, sid, H5P_DEFAULT, dcpl, H5P_DEFAULT)) < 0)
+        FAIL_STACK_ERROR
+
+    /* Select last element in the dataset */
+    hs_offset = dim - 1;
+    hs_size = 1;
+    if(H5Sselect_hyperslab(sid, H5S_SELECT_SET, &hs_offset, NULL, &hs_size, NULL) < 0) FAIL_STACK_ERROR
+
+    /* Read (unwritten) element from dataset */
+    read_elem = 1;
+    if(H5Dread(dsid, H5T_NATIVE_UINT, scalar_sid, sid, H5P_DEFAULT, &read_elem) < 0) FAIL_STACK_ERROR
+
+    /* Verify unwritten element is fill value (0) */
+    if(read_elem != 0) FAIL_PUTS_ERROR("invalid unwritten element read");
+
+    /* Write element to dataset */
+    write_elem = 2;
+    if(H5Dwrite(dsid, H5T_NATIVE_UINT, scalar_sid, sid, H5P_DEFAULT, &write_elem) < 0) FAIL_STACK_ERROR
+
+    /* Read element from dataset */
+    read_elem = write_elem + 1;
+    if(H5Dread(dsid, H5T_NATIVE_UINT, scalar_sid, sid, H5P_DEFAULT, &read_elem) < 0) FAIL_STACK_ERROR
+
+    /* Verify written element is read in */
+    if(read_elem != write_elem) FAIL_PUTS_ERROR("invalid written element read");
+
+    /* Shrink dataset to 512 KB */
+    dim = 512 * 1024 / sizeof(unsigned);
+    if(H5Dset_extent(dsid, &dim) < 0) FAIL_STACK_ERROR
+
+    /* Expand dataset back to 2MB */
+    dim = 2 * 1024 * 1024 / sizeof(unsigned);
+    if(H5Dset_extent(dsid, &dim) < 0) FAIL_STACK_ERROR
+
+    /* Read element from dataset */
+    read_elem = 1;
+    if(H5Dread(dsid, H5T_NATIVE_UINT, scalar_sid, sid, H5P_DEFAULT, &read_elem) < 0) FAIL_STACK_ERROR
+
+    /* Verify element is now 0 */
+    if(read_elem != 0) FAIL_PUTS_ERROR("invalid element read");
+
+    /* Close everything */
+    if(H5Sclose(sid) < 0) FAIL_STACK_ERROR
+    if(H5Sclose(scalar_sid) < 0) FAIL_STACK_ERROR
+    if(H5Dclose(dsid) < 0) FAIL_STACK_ERROR
+    if(H5Pclose(dcpl) < 0) FAIL_STACK_ERROR
+    if(H5Fclose(fid) < 0) FAIL_STACK_ERROR
+
+    PASSED();
+
+    return 0;
+
+error:
+    H5E_BEGIN_TRY {
+        H5Pclose(dcpl);
+        H5Dclose(dsid);
+        H5Sclose(sid);
+        H5Sclose(scalar_sid);
+        H5Fclose(fid);
+    } H5E_END_TRY;
+    return -1;
+} /* end test_large_chunk_shrink() */
+
 
 /*-------------------------------------------------------------------------
  * Function:	main
@@ -8193,6 +8308,7 @@ main(void)
         nerrors += (test_big_chunks_bypass_cache(my_fapl) < 0   ? 1 : 0);
         nerrors += (test_chunk_expand(my_fapl) < 0		? 1 : 0);
 	nerrors += (test_layout_extend(my_fapl) < 0		? 1 : 0);
+	nerrors += (test_large_chunk_shrink(my_fapl) < 0        ? 1 : 0);
 
         if(H5Fclose(file) < 0)
             goto error;