Onion VFD (#1953)

* Onion VFD feature

* Fixes onion VFD errors with non-sec2 backing store VFDs

* Disables the onion VFD tests w/ ph5diff

* Disables non-sec2 VFDs as onion VFD backing stores

* Committing clang-format changes

* Formatted source

* Typo

* Adds onion VFD tools tests to CMake

* Fixes for v16 API compatibility

* Memset structs to avoid bad frees on errors

* H5Dwrite() calls now use H5T_NATIVE_INT as the memory type vs LE

* Properly decodes checksums on BE machines

* Be more careful about uint64_t to haddr_t/hsize_t conversions

* Another fix for BE data comparison

* Removed double underscores from onion constants

* Replace hard-coded onion header string w/ constant

* Fixes cleanup paths in H5FD__onion_ingest_history()

* Fixed use of size_t revision numbers

* Fix h5dump revision count format string

Co-authored-by: github-actions <41898282+github-actions[bot]@users.noreply.github.com>

3 files changed, 712 insertions, 1 deletions

diff --git a/tools/test/h5dump/CMakeTests.cmake b/tools/test/h5dump/CMakeTests.cmake
index 933aba9..4fa9a8f 100644
--- a/tools/test/h5dump/CMakeTests.cmake
+++ b/tools/test/h5dump/CMakeTests.cmake
@@ -211,6 +211,11 @@
       ${HDF5_TOOLS_DIR}/testfiles/trefer_paramR.ddl
       ${HDF5_TOOLS_DIR}/testfiles/trefer_reg_1dR.ddl
       ${HDF5_TOOLS_DIR}/testfiles/trefer_regR.ddl
+      # Onion VFD files
+      ${HDF5_TOOLS_DIR}/testfiles/tst_onion_objs.ddl
+      ${HDF5_TOOLS_DIR}/testfiles/tst_onion_dset_ext.ddl
+      ${HDF5_TOOLS_DIR}/testfiles/tst_onion_dset_1d.ddl
+      ${HDF5_TOOLS_DIR}/testfiles/tst_onion_revision_count.ddl
   )
   set (HDF5_N_REFERENCE_FILES
       tall-3
@@ -350,7 +355,13 @@
       ${HDF5_TOOLS_DIR}/testfiles/trefer_param.h5
       ${HDF5_TOOLS_DIR}/testfiles/trefer_reg_1d.h5
       ${HDF5_TOOLS_DIR}/testfiles/trefer_reg.h5
-
+      # Onion VFD files
+      ${HDF5_TOOLS_DIR}/testfiles/tst_onion_objs.h5
+      ${HDF5_TOOLS_DIR}/testfiles/tst_onion_objs.h5.onion
+      ${HDF5_TOOLS_DIR}/testfiles/tst_onion_dset_ext.h5
+      ${HDF5_TOOLS_DIR}/testfiles/tst_onion_dset_ext.h5.onion
+      ${HDF5_TOOLS_DIR}/testfiles/tst_onion_dset_1d.h5
+      ${HDF5_TOOLS_DIR}/testfiles/tst_onion_dset_1d.h5.onion
   )
   set (HDF5_ERROR_REFERENCE_TEST_FILES
       ${PROJECT_SOURCE_DIR}/errfiles/filter_fail.err
@@ -1187,6 +1198,13 @@
   ADD_H5_TEST (tCVE_2018_11206_fill_old 1 tCVE_2018_11206_fill_old.h5)
   ADD_H5_TEST (tCVE_2018_11206_fill_new 1 tCVE_2018_11206_fill_new.h5)
 
+  # onion VFD tests
+  ADD_H5_TEST (tst_onion_objs 0 --enable-error-stack --vfd-name onion --vfd-info 3 tst_onion_objs.h5)
+  ADD_H5_TEST (tst_onion_dset_ext 0 --enable-error-stack --vfd-name onion --vfd-info 1 tst_onion_dset_ext.h5)
+  ADD_H5_TEST (tst_onion_dset_1d 0 --enable-error-stack --vfd-name onion --vfd-info 1 tst_onion_dset_1d.h5)
+  ADD_H5_TEST (tst_onion_revision_count 0 --enable-error-stack --vfd-name onion --vfd-info revision_count tst_onion_objs.h5)
+
+
 ##############################################################################
 ###    P L U G I N  T E S T S
 ##############################################################################
diff --git a/tools/test/h5dump/h5dumpgentest.c b/tools/test/h5dump/h5dumpgentest.c
index 30e0c46..08f241c 100644
--- a/tools/test/h5dump/h5dumpgentest.c
+++ b/tools/test/h5dump/h5dumpgentest.c
@@ -117,6 +117,13 @@
 #define FILE87     "tintsnodata.h5"
 #define FILE88     "tldouble_scalar.h5"
 #define FILE89     "tfloatsattrs.h5"
+#define FILE90     "tst_onion_dset_1d.h5"
+#define FILE91     "tst_onion_objs.h5"
+#define FILE92     "tst_onion_dset_ext.h5"
+
+#define ONION_TEST_FIXNAME_SIZE 1024
+#define ONION_TEST_PAGE_SIZE    (uint32_t)32
+#define ONE_DIM_SIZE            16
 
 /*-------------------------------------------------------------------------
  * prototypes
@@ -11350,6 +11357,671 @@ error:
     H5E_END_TRY;
 } /* gen_err_attr_dspace() */
 
+/* Structure to collect the onion filepaths in one place. */
+struct onion_filepaths {
+    char *canon;
+    char *onion;
+    char *recovery;
+};
+
+/* Allocate and populate filepaths with h5_fixname'd strings as appropriate.
+ * Should be released with onion_filepaths_destroy() when done.
+ */
+static struct onion_filepaths *
+onion_filepaths_init(const char *basename)
+{
+    struct onion_filepaths *paths = NULL;
+
+    if (NULL == (paths = HDcalloc(1, sizeof(struct onion_filepaths))))
+        goto error;
+
+    if (NULL == (paths->canon = HDstrdup(basename)))
+        goto error;
+
+    if (NULL == (paths->onion = HDmalloc(sizeof(char) * ONION_TEST_FIXNAME_SIZE)))
+        goto error;
+    HDsnprintf(paths->onion, ONION_TEST_FIXNAME_SIZE, "%s.onion", paths->canon);
+
+    if (NULL == (paths->recovery = HDmalloc(sizeof(char) * ONION_TEST_FIXNAME_SIZE)))
+        goto error;
+    HDsnprintf(paths->recovery, ONION_TEST_FIXNAME_SIZE, "%s.onion.recovery", paths->canon);
+
+    return paths;
+
+error:
+    if (paths != NULL) {
+        HDfree(paths->canon);
+        HDfree(paths->onion);
+        HDfree(paths->recovery);
+        HDfree(paths);
+    }
+    return NULL;
+}
+
+static void
+onion_filepaths_destroy(struct onion_filepaths *s)
+{
+    if (s) {
+        HDfree(s->canon);
+        HDfree(s->onion);
+        HDfree(s->recovery);
+        HDfree(s);
+    }
+}
+
+static int
+gent_onion_1d_dset(void)
+{
+    hid_t                   file_id    = H5I_INVALID_HID;
+    hid_t                   file       = H5I_INVALID_HID;
+    hid_t                   space      = H5I_INVALID_HID;
+    hid_t                   dset       = H5I_INVALID_HID;
+    hid_t                   dcpl       = H5I_INVALID_HID;
+    hid_t                   fapl_id    = H5I_INVALID_HID;
+    struct onion_filepaths *paths      = NULL;
+    H5FD_onion_fapl_info_t  onion_info = {
+        H5FD_ONION_FAPL_INFO_VERSION_CURR,
+        H5I_INVALID_HID,               /* backing_fapl_id  */
+        ONION_TEST_PAGE_SIZE,          /* page_size        */
+        H5FD_ONION_STORE_TARGET_ONION, /* store_target     */
+        H5FD_ONION_FAPL_INFO_REVISION_ID_LATEST,
+        0,               /* force_write_open */
+        0,               /* creation flags, was H5FD_ONION_FAPL_INFO_CREATE_FLAG_ENABLE_PAGE_ALIGNMENT */
+        "initial commit" /* comment          */
+    };
+    hsize_t dims[2]    = {1, ONE_DIM_SIZE};
+    hsize_t maxdims[2] = {1, ONE_DIM_SIZE};
+    int     wdata[1][ONE_DIM_SIZE];
+    int     fillval;
+
+    /* Setup */
+    onion_info.backing_fapl_id = H5Pcreate(H5P_FILE_ACCESS);
+
+    if ((fapl_id = H5Pcreate(H5P_FILE_ACCESS)) < 0)
+        goto error;
+    if (H5Pset_fapl_onion(fapl_id, &onion_info) < 0)
+        goto error;
+
+    if ((paths = onion_filepaths_init(FILE90)) == NULL)
+        goto error;
+
+    /*----------------------------------------------------------------------
+     * Create the skeleton file (create the file without Onion VFD)
+     *----------------------------------------------------------------------
+     */
+    /* Initialize data */
+    for (int i = 0; i < ONE_DIM_SIZE; i++)
+        wdata[0][i] = i;
+
+    /* Create a new file using the default properties */
+    if ((file = H5Fcreate(paths->canon, H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT)) < 0)
+        goto error;
+
+    /* Create dataspace with unlimited dimensions */
+    if ((space = H5Screate_simple(2, dims, maxdims)) < 0)
+        goto error;
+
+    /* Create the dataset creation property list */
+    if ((dcpl = H5Pcreate(H5P_DATASET_CREATE)) < 0)
+        goto error;
+
+    /* Set the fill value for the dataset */
+    fillval = 99;
+    if (H5Pset_fill_value(dcpl, H5T_NATIVE_INT, &fillval) < 0)
+        goto error;
+
+    /* Set the allocation time to "early". This way we can be sure
+     * that reading from the dataset immediately after creation will
+     * return the fill value.
+     */
+    if (H5Pset_alloc_time(dcpl, H5D_ALLOC_TIME_EARLY) < 0)
+        goto error;
+
+    /* Create the dataset using the dataset creation property list */
+    if ((dset = H5Dcreate2(file, "DS1", H5T_STD_I32LE, space, H5P_DEFAULT, dcpl, H5P_DEFAULT)) < 0)
+        goto error;
+
+    /* Write the data to the dataset */
+    if (H5Dwrite(dset, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT, wdata[0]) < 0)
+        goto error;
+
+    /* Close and release resources */
+    if (H5Pclose(dcpl) < 0)
+        goto error;
+    if (H5Dclose(dset) < 0)
+        goto error;
+    if (H5Sclose(space) < 0)
+        goto error;
+    if (H5Fclose(file) < 0)
+        goto error;
+
+    /*----------------------------------------------------------------------
+     * First revision: open the file with Onion VFD and change the data
+     *----------------------------------------------------------------------
+     */
+    if ((file_id = H5Fopen(paths->canon, H5F_ACC_RDWR, fapl_id)) < 0)
+        goto error;
+
+    if ((dset = H5Dopen2(file_id, "DS1", H5P_DEFAULT)) < 0)
+        goto error;
+
+    int dset_data[1][ONE_DIM_SIZE];
+    for (int i = 0; i < ONE_DIM_SIZE; i++)
+        dset_data[0][i] = i + ONE_DIM_SIZE;
+
+    if (H5Dwrite(dset, H5T_STD_I32LE, H5S_ALL, H5S_ALL, H5P_DEFAULT, dset_data) < 0)
+        goto error;
+
+    if (H5Dclose(dset) < 0)
+        goto error;
+    if (H5Fclose(file_id) < 0)
+        goto error;
+
+    /*----------------------------------------------------------------------
+     * Second revision: open the file with Onion VFD and change the data
+     *----------------------------------------------------------------------
+     */
+    if ((file_id = H5Fopen(paths->canon, H5F_ACC_RDWR, fapl_id)) < 0)
+        goto error;
+
+    if ((dset = H5Dopen2(file_id, "DS1", H5P_DEFAULT)) < 0)
+        goto error;
+
+    for (int i = 0; i < ONE_DIM_SIZE; i++)
+        dset_data[0][i] = i + 2048;
+
+    if (H5Dwrite(dset, H5T_STD_I32LE, H5S_ALL, H5S_ALL, H5P_DEFAULT, dset_data) < 0)
+        goto error;
+
+    /* CLEANUP */
+    if (H5Dclose(dset) < 0)
+        goto error;
+    dset = H5I_INVALID_HID;
+    if (H5Fclose(file_id) < 0)
+        goto error;
+    file_id = H5I_INVALID_HID;
+
+    /*----------------------------------------------------------------------
+     * Third revision: open the file with Onion VFD and change the data
+     *----------------------------------------------------------------------
+     */
+    if ((file_id = H5Fopen(paths->canon, H5F_ACC_RDWR, fapl_id)) < 0)
+        goto error;
+
+    if ((dset = H5Dopen2(file_id, "DS1", H5P_DEFAULT)) < 0)
+        goto error;
+
+    for (int i = 0; i < ONE_DIM_SIZE; i += 20)
+        dset_data[0][i] = i + 3072;
+
+    if (H5Dwrite(dset, H5T_STD_I32LE, H5S_ALL, H5S_ALL, H5P_DEFAULT, dset_data) < 0)
+        goto error;
+
+    /* CLEANUP */
+    if (H5Dclose(dset) < 0)
+        goto error;
+    if (H5Fclose(file_id) < 0)
+        goto error;
+    if (H5Pclose(fapl_id) < 0)
+        goto error;
+    if (H5Pclose(onion_info.backing_fapl_id) < 0)
+        goto error;
+
+    onion_filepaths_destroy(paths);
+
+    return 0;
+
+error:
+    H5E_BEGIN_TRY
+    {
+        H5Pclose(onion_info.backing_fapl_id);
+        H5Pclose(fapl_id);
+        H5Dclose(dset);
+        H5Sclose(space);
+        H5Fclose(file_id);
+    }
+    H5E_END_TRY;
+
+    return -1;
+} /* gent_onion_1d_dset */
+
+static int
+gent_onion_create_delete_objects(void)
+{
+    struct onion_filepaths *paths = NULL;
+
+    H5FD_onion_fapl_info_t onion_info = {
+        H5FD_ONION_FAPL_INFO_VERSION_CURR,
+        H5I_INVALID_HID,               /* backing_fapl_id  */
+        ONION_TEST_PAGE_SIZE,          /* page_size        */
+        H5FD_ONION_STORE_TARGET_ONION, /* store_target     */
+        H5FD_ONION_FAPL_INFO_REVISION_ID_LATEST,
+        0,               /* force_write_open */
+        0,               /* creation flags, was H5FD_ONION_FAPL_INFO_CREATE_FLAG_ENABLE_PAGE_ALIGNMENT */
+        "initial commit" /* comment          */
+    };
+
+    hid_t fapl_id       = H5I_INVALID_HID;
+    hid_t group_id      = H5I_INVALID_HID;
+    hid_t attr_space_id = H5I_INVALID_HID;
+    hid_t attr_id       = H5I_INVALID_HID;
+    hid_t file          = H5I_INVALID_HID;
+    hid_t space         = H5I_INVALID_HID;
+    hid_t dset          = H5I_INVALID_HID;
+    hid_t dcpl          = H5I_INVALID_HID;
+
+    hsize_t attr_dim[1] = {4};
+    hsize_t dims[2]     = {4, 4};
+    hsize_t maxdims[2]  = {H5S_UNLIMITED, H5S_UNLIMITED};
+    hsize_t chunk[2]    = {4, 4};
+    int     wdata[4][4];
+
+    int fillval;
+
+    /* Set up */
+    if ((onion_info.backing_fapl_id = H5Pcreate(H5P_FILE_ACCESS)) < 0)
+        goto error;
+    if ((fapl_id = H5Pcreate(H5P_FILE_ACCESS)) < 0)
+        goto error;
+    if (H5Pset_fapl_onion(fapl_id, &onion_info) < 0)
+        goto error;
+
+    if ((paths = onion_filepaths_init(FILE91)) == NULL)
+        goto error;
+
+    /*----------------------------------------------------------------------
+     * Create the skeleton file (create the file without Onion VFD)
+     *----------------------------------------------------------------------
+     */
+
+    /*
+     * Initialize data.
+     */
+    for (int i = 0; i < 4; i++)
+        for (int j = 0; j < 4; j++)
+            wdata[i][j] = i + j;
+
+    /*
+     * Create a new file using the default properties.
+     */
+    if ((file = H5Fcreate(paths->canon, H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT)) < 0)
+        goto error;
+
+    /*
+     * Create dataspace with unlimited dimensions.
+     */
+    if ((space = H5Screate_simple(2, dims, maxdims)) < 0)
+        goto error;
+
+    /*
+     * Create the dataset creation property list, and set the chunk
+     * size.
+     */
+    if ((dcpl = H5Pcreate(H5P_DATASET_CREATE)) < 0)
+        goto error;
+    if (H5Pset_chunk(dcpl, 2, chunk) < 0)
+        goto error;
+
+    /*
+     * Set the fill value for the dataset.
+     */
+    fillval = 99;
+    if (H5Pset_fill_value(dcpl, H5T_NATIVE_INT, &fillval) < 0)
+        goto error;
+
+    /*
+     * Set the allocation time to "early".  This way we can be sure
+     * that reading from the dataset immediately after creation will
+     * return the fill value.
+     */
+    if (H5Pset_alloc_time(dcpl, H5D_ALLOC_TIME_EARLY) < 0)
+        goto error;
+
+    /*
+     * Create the dataset using the dataset creation property list.
+     */
+    if ((dset = H5Dcreate2(file, "DS1", H5T_STD_I32LE, space, H5P_DEFAULT, dcpl, H5P_DEFAULT)) < 0)
+        goto error;
+
+    /*
+     * Write the data to the dataset.
+     */
+    if (H5Dwrite(dset, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT, wdata) < 0)
+        goto error;
+
+    if (H5Dclose(dset) < 0)
+        goto error;
+    if (H5Fclose(file) < 0)
+        goto error;
+
+    /*----------------------------------------------------------------------
+     * First revision: open the file with Onion VFD and add a dataset (DS2) to the file
+     *----------------------------------------------------------------------
+     */
+    if ((file = H5Fopen(paths->canon, H5F_ACC_RDWR, fapl_id)) < 0)
+        goto error;
+
+    /*
+     * Create the dataset using the dataset creation property list.
+     */
+    if ((dset = H5Dcreate2(file, "DS2", H5T_STD_I32LE, space, H5P_DEFAULT, dcpl, H5P_DEFAULT)) < 0)
+        goto error;
+
+    /*
+     * Write the data to the dataset.
+     */
+    if (H5Dwrite(dset, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT, wdata) < 0)
+        goto error;
+
+    if (H5Dclose(dset) < 0)
+        goto error;
+    dset = H5I_INVALID_HID;
+    if (H5Fclose(file) < 0)
+        goto error;
+    file = H5I_INVALID_HID;
+
+    /*----------------------------------------------------------------------
+     * Second revision: open the file with Onion VFD and remove the dataset (DS2),
+     * which was added during the first revision.
+     *----------------------------------------------------------------------
+     */
+    if ((file = H5Fopen(paths->canon, H5F_ACC_RDWR, fapl_id)) < 0)
+        goto error;
+
+    if (H5Ldelete(file, "DS2", H5P_DEFAULT) < 0)
+        goto error;
+
+    if (H5Fclose(file) < 0)
+        goto error;
+    file = H5I_INVALID_HID;
+
+    /*----------------------------------------------------------------------
+     * Third revision: open the file with Onion VFD and add an attribute to the file
+     *----------------------------------------------------------------------
+     */
+    if ((file = H5Fopen(paths->canon, H5F_ACC_RDWR, fapl_id)) < 0)
+        goto error;
+
+    /* Create dataspace for attribute */
+    attr_space_id = H5Screate_simple(1, attr_dim, NULL);
+
+    if ((attr_id =
+             H5Acreate2(file, "file_attribute", H5T_STD_I32LE, attr_space_id, H5P_DEFAULT, H5P_DEFAULT)) < 0)
+        goto error;
+
+    if (H5Sclose(attr_space_id) < 0)
+        goto error;
+    if (H5Aclose(attr_id) < 0)
+        goto error;
+    if (H5Fclose(file) < 0)
+        goto error;
+    file = H5I_INVALID_HID;
+
+    /*----------------------------------------------------------------------
+     * Fourth revision: open the file with Onion VFD and delete the attribute
+     *----------------------------------------------------------------------
+     */
+    if ((file = H5Fopen(paths->canon, H5F_ACC_RDWR, fapl_id)) < 0)
+        goto error;
+
+    if (H5Adelete(file, "file_attribute") < 0)
+        goto error;
+
+    if (H5Fclose(file) < 0)
+        goto error;
+    file = H5I_INVALID_HID;
+
+    /*----------------------------------------------------------------------
+     * Fifth revision: open the file with Onion VFD and add a group to the file
+     *----------------------------------------------------------------------
+     */
+    if ((file = H5Fopen(paths->canon, H5F_ACC_RDWR, fapl_id)) < 0)
+        goto error;
+
+    if ((group_id = H5Gcreate2(file, "new_group", H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT)) < 0)
+        goto error;
+
+    if (H5Gclose(group_id) < 0)
+        goto error;
+    if (H5Fclose(file) < 0)
+        goto error;
+    file = H5I_INVALID_HID;
+
+    /*----------------------------------------------------------------------
+     * Sixth revision: open the file with Onion VFD and delete the newly added group
+     *----------------------------------------------------------------------
+     */
+    if ((file = H5Fopen(paths->canon, H5F_ACC_RDWR, fapl_id)) < 0)
+        goto error;
+
+    if (H5Ldelete(file, "new_group", H5P_DEFAULT) < 0)
+        goto error;
+
+    if (H5Fclose(file) < 0)
+        goto error;
+    file = H5I_INVALID_HID;
+
+    /*
+     * Close and release resources.
+     */
+    if (H5Pclose(onion_info.backing_fapl_id) < 0)
+        goto error;
+    if (H5Pclose(fapl_id) < 0)
+        goto error;
+    if (H5Pclose(dcpl) < 0)
+        goto error;
+    if (H5Sclose(space) < 0)
+        goto error;
+
+    onion_filepaths_destroy(paths);
+
+    return 0;
+error:
+
+    if (paths != NULL) {
+        HDremove(paths->canon);
+        HDremove(paths->onion);
+        HDremove(paths->recovery);
+        onion_filepaths_destroy(paths);
+    }
+
+    if (dset != H5I_INVALID_HID)
+        (void)H5Dclose(dset);
+    if (file != H5I_INVALID_HID)
+        (void)H5Fclose(file);
+    if (fapl_id != H5I_INVALID_HID)
+        (void)H5Pclose(fapl_id);
+    if (onion_info.backing_fapl_id != H5I_INVALID_HID)
+        H5Pclose(onion_info.backing_fapl_id);
+
+    return -1;
+} /* gent_onion_create_delete_objects */
+
+static int
+gent_onion_dset_extension(void)
+{
+    hid_t                   fapl_id    = H5I_INVALID_HID;
+    hid_t                   file       = H5I_INVALID_HID;
+    hid_t                   space      = H5I_INVALID_HID;
+    hid_t                   dset_space = H5I_INVALID_HID;
+    hid_t                   dset       = H5I_INVALID_HID;
+    hid_t                   dcpl       = H5I_INVALID_HID;
+    struct onion_filepaths *paths      = NULL;
+    H5FD_onion_fapl_info_t  onion_info = {
+        H5FD_ONION_FAPL_INFO_VERSION_CURR,
+        H5I_INVALID_HID,               /* backing_fapl_id  */
+        ONION_TEST_PAGE_SIZE,          /* page_size        */
+        H5FD_ONION_STORE_TARGET_ONION, /* store_target     */
+        H5FD_ONION_FAPL_INFO_REVISION_ID_LATEST,
+        0,               /* force_write_open */
+        0,               /* creation flags, was H5FD_ONION_FAPL_INFO_CREATE_FLAG_ENABLE_PAGE_ALIGNMENT */
+        "initial commit" /* comment          */
+    };
+    hsize_t dims[2]    = {4, 4};
+    hsize_t maxdims[2] = {H5S_UNLIMITED, H5S_UNLIMITED};
+    hsize_t chunk[2]   = {4, 4};
+    hsize_t size[2];
+    hsize_t offset[2];
+    int     wdata[4][4]; /* Write buffer */
+    int     fillval;
+
+    /* Setup */
+    if ((onion_info.backing_fapl_id = H5Pcreate(H5P_FILE_ACCESS)) < 0)
+        goto error;
+    if ((fapl_id = H5Pcreate(H5P_FILE_ACCESS)) < 0)
+        goto error;
+
+    if (H5Pset_fapl_onion(fapl_id, &onion_info) < 0)
+        goto error;
+
+    if ((paths = onion_filepaths_init(FILE92)) == NULL)
+        goto error;
+
+    /*----------------------------------------------------------------------
+     * Create the skeleton file (create the file without Onion VFD)
+     *----------------------------------------------------------------------
+     */
+    /* Initialize data */
+    for (int i = 0; i < 4; i++)
+        for (int j = 0; j < 4; j++)
+            wdata[i][j] = i + j;
+
+    /* Create a new file using the default properties */
+    if ((file = H5Fcreate(paths->canon, H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT)) < 0)
+        goto error;
+
+    /* Create dataspace with unlimited dimensions */
+    if ((space = H5Screate_simple(2, dims, maxdims)) < 0)
+        goto error;
+
+    /* Create the dataset creation property list, and set the chunk
+     * size.
+     */
+    if ((dcpl = H5Pcreate(H5P_DATASET_CREATE)) < 0)
+        goto error;
+    if (H5Pset_chunk(dcpl, 2, chunk) < 0)
+        goto error;
+
+    /* Set the fill value for the dataset */
+    fillval = 99;
+    if (H5Pset_fill_value(dcpl, H5T_NATIVE_INT, &fillval) < 0)
+        goto error;
+
+    /* Set the allocation time to "early". This way we can be sure
+     * that reading from the dataset immediately after creation will
+     * return the fill value.
+     */
+    if (H5Pset_alloc_time(dcpl, H5D_ALLOC_TIME_EARLY) < 0)
+        goto error;
+
+    /* Create the dataset using the dataset creation property list */
+    if ((dset = H5Dcreate2(file, "DS1", H5T_STD_I32LE, space, H5P_DEFAULT, dcpl, H5P_DEFAULT)) < 0)
+        goto error;
+
+    /* Write the data to the dataset */
+    if (H5Dwrite(dset, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT, wdata) < 0)
+        goto error;
+
+    if (H5Dclose(dset) < 0)
+        goto error;
+    if (H5Fclose(file) < 0)
+        goto error;
+
+    /*----------------------------------------------------------------------
+     * First revision: open the file with Onion VFD and extend the dataset
+     *----------------------------------------------------------------------
+     */
+    if ((file = H5Fopen(paths->canon, H5F_ACC_RDWR, fapl_id)) < 0)
+        goto error;
+
+    /* Open the dataset */
+    if ((dset = H5Dopen2(file, "DS1", H5P_DEFAULT)) < 0)
+        goto error;
+
+    /* Extend the dataset and double the rows */
+    size[0] = 2 * dims[0];
+    size[1] = dims[1];
+    if (H5Dset_extent(dset, size) < 0)
+        goto error;
+
+    if ((dset_space = H5Dget_space(dset)) < 0)
+        goto error;
+
+    offset[0] = dims[0];
+    offset[1] = 0;
+    if (H5Sselect_hyperslab(dset_space, H5S_SELECT_SET, offset, NULL, dims, NULL) < 0)
+        goto error;
+
+    /* Write the data to the dataset. */
+    if (H5Dwrite(dset, H5T_NATIVE_INT, space, dset_space, H5P_DEFAULT, wdata) < 0)
+        goto error;
+
+    if (H5Sclose(dset_space) < 0)
+        goto error;
+
+    if (H5Dclose(dset) < 0)
+        goto error;
+    dset = H5I_INVALID_HID;
+    if (H5Fclose(file) < 0)
+        goto error;
+    file = H5I_INVALID_HID;
+
+    /*----------------------------------------------------------------------
+     * Second revision: open the file with Onion VFD and shrink the dataset
+     *----------------------------------------------------------------------
+     */
+    if ((file = H5Fopen(paths->canon, H5F_ACC_RDWR, fapl_id)) < 0)
+        goto error;
+
+    /* Open the dataset */
+    if ((dset = H5Dopen2(file, "DS1", H5P_DEFAULT)) < 0)
+        goto error;
+
+    /* Extend the dataset and shrink back the size */
+    if (H5Dset_extent(dset, dims) < 0)
+        goto error;
+
+    if (H5Dclose(dset) < 0)
+        goto error;
+    dset = H5I_INVALID_HID;
+    if (H5Fclose(file) < 0)
+        goto error;
+    file = H5I_INVALID_HID;
+
+    /* Close and release resources. */
+    if (H5Pclose(onion_info.backing_fapl_id) < 0)
+        goto error;
+    if (H5Pclose(fapl_id) < 0)
+        goto error;
+    if (H5Pclose(dcpl) < 0)
+        goto error;
+    if (H5Sclose(space) < 0)
+        goto error;
+
+    onion_filepaths_destroy(paths);
+
+    return 0;
+error:
+
+    if (paths != NULL) {
+        HDremove(paths->canon);
+        HDremove(paths->onion);
+        HDremove(paths->recovery);
+        onion_filepaths_destroy(paths);
+    }
+
+    H5E_BEGIN_TRY
+    {
+        H5Dclose(dset);
+        H5Fclose(file);
+        H5Pclose(fapl_id);
+        H5Pclose(onion_info.backing_fapl_id);
+    }
+    H5E_END_TRY;
+
+    return -1;
+} /* gent_onion_dset_extension */
+
 int
 main(void)
 {
@@ -11449,5 +12121,10 @@ main(void)
 
     gent_err_attr_dspace();
 
+    /* Generate the files for testing Onion VFD */
+    gent_onion_1d_dset();
+    gent_onion_create_delete_objects();
+    gent_onion_dset_extension();
+
     return 0;
 }
diff --git a/tools/test/h5dump/testh5dump.sh.in b/tools/test/h5dump/testh5dump.sh.in
index f9f3734..ce7f643 100644
--- a/tools/test/h5dump/testh5dump.sh.in
+++ b/tools/test/h5dump/testh5dump.sh.in
@@ -184,6 +184,12 @@ $SRC_H5DUMP_TESTFILES/tvms.h5
 $SRC_H5DUMP_TESTFILES/err_attr_dspace.h5
 $SRC_H5DUMP_TESTFILES/tCVE_2018_11206_fill_old.h5
 $SRC_H5DUMP_TESTFILES/tCVE_2018_11206_fill_new.h5
+$SRC_H5DUMP_TESTFILES/tst_onion_objs.h5
+$SRC_H5DUMP_TESTFILES/tst_onion_objs.h5.onion
+$SRC_H5DUMP_TESTFILES/tst_onion_dset_ext.h5
+$SRC_H5DUMP_TESTFILES/tst_onion_dset_ext.h5.onion
+$SRC_H5DUMP_TESTFILES/tst_onion_dset_1d.h5
+$SRC_H5DUMP_TESTFILES/tst_onion_dset_1d.h5.onion
 "
 
 LIST_OTHER_TEST_FILES="
@@ -372,6 +378,10 @@ $SRC_H5DUMP_TESTFILES/h5dump-help.txt
 $SRC_H5DUMP_TESTFILES/out3.h5import
 $SRC_H5DUMP_TESTFILES/tbinregR.exp
 $SRC_H5DUMP_TESTFILES/err_attr_dspace.ddl
+$SRC_H5DUMP_TESTFILES/tst_onion_objs.ddl
+$SRC_H5DUMP_TESTFILES/tst_onion_dset_ext.ddl
+$SRC_H5DUMP_TESTFILES/tst_onion_dset_1d.ddl
+$SRC_H5DUMP_TESTFILES/tst_onion_revision_count.ddl
 "
 
 LIST_ERROR_TEST_FILES="
@@ -1486,6 +1496,12 @@ TOOLTEST err_attr_dspace.ddl err_attr_dspace.h5
 TOOLTEST_FAIL tCVE_2018_11206_fill_old.h5
 TOOLTEST_FAIL tCVE_2018_11206_fill_new.h5
 
+# test Onion VFD
+TOOLTEST tst_onion_objs.ddl --enable-error-stack --vfd-name onion --vfd-info 3 tst_onion_objs.h5
+TOOLTEST tst_onion_dset_ext.ddl --enable-error-stack --vfd-name onion --vfd-info 1 tst_onion_dset_ext.h5
+TOOLTEST tst_onion_dset_1d.ddl --enable-error-stack --vfd-name onion --vfd-info 1 tst_onion_dset_1d.h5
+TOOLTEST tst_onion_revision_count.ddl --enable-error-stack --vfd-name onion --vfd-info revision_count tst_onion_objs.h5
+
 # Clean up temporary files/directories
 CLEAN_TESTFILES_AND_TESTDIR