Merge pull request #548 in HDFFV/hdf5 from ~DEROBINS/hdf5_der:compat_feature_flag to develop

* commit '13d3d4bd0e0b799aa9c3a9b45e445d1f52294d47':
  Added feature flag checks for a few other VFDs in test/vfd.c.
  * Added new public H5FDdriver_query() API call. * Changed return type of H5FD_driver_query() to herr_t. * Updated swmr.c to use H5FDdriver_query() instead of the private call. * Added some flags tests to vfd.c.
  * Made H5FD_driver_query() a private function instead of static. * Moved H5FD_driver_query() to H5FDint.c. * Minor typo fixes in H5I.c. * Updated swmr.c to check the VFD feature flags and skip the   retries test when the VFD is not compatible with H5P_DEFAULT.
  Initialized IDs to -1 and minor code tidy.
  Fixed HDFFV-10214: * Updated comments in the library to accurately reflect the semantics   of the H5FD_FEAT_POSIX_COMPAT_HANDLE flag. * Removed the check for the POSIX compatible handle feature flag   when determining if a VFD supports SWMR. Partial work for HDFFV-10197: * Added a new H5FD_FEAT_DEFAULT_VFD_COMPATIBLE feature flag that is   set when a VFD creates output that is compatible with the default   VFD. Will be used in the testing but might also be generally useful   to users.

14 files changed, 292 insertions, 64 deletions

diff --git a/src/H5FD.c b/src/H5FD.c
index dcfaa6d..67cf963 100644
--- a/src/H5FD.c
+++ b/src/H5FD.c
@@ -62,7 +62,6 @@
 /********************/
 static herr_t H5FD_free_cls(H5FD_class_t *cls);
 static int H5FD_query(const H5FD_t *f, unsigned long *flags/*out*/);
-static int H5FD_driver_query(const H5FD_class_t *driver, unsigned long *flags/*out*/);
 
 /*********************/
 /* Package Variables */
@@ -790,7 +789,8 @@ H5FD_open(const char *name, unsigned flags, hid_t fapl_id, haddr_t maxaddr)
 	HGOTO_ERROR(H5E_VFL, H5E_UNSUPPORTED, NULL, "file driver has no `open' method")
 
     /* Query driver flag */
-    H5FD_driver_query(driver, &driver_flags);
+    if(H5FD_driver_query(driver, &driver_flags) < 0)
+        HGOTO_ERROR(H5E_VFL, H5E_BADVALUE, NULL, "can't query VFD flags")
 
     /* Get initial file image info */
     if(H5P_peek(plist, H5F_ACS_FILE_IMAGE_INFO_NAME, &file_image_info) < 0)
@@ -1085,42 +1085,6 @@ H5FD_query(const H5FD_t *f, unsigned long *flags/*out*/)
 
 
 /*-------------------------------------------------------------------------
-* Function:    H5FD_driver_query
-*
-* Purpose: Similar to H5FD_query(), but intended for cases when we don't
-*          have a file available (e.g. before one is opened). Since we
-*          can't use the file to get the driver, the driver is passed in
-*          as a parameter.
-*
-* Return:  Success:    non-negative
-*          Failure:    negative
-*
-* Programmer:  Jacob Gruber
-*              Wednesday, August 17, 2011
-*
-*-------------------------------------------------------------------------
-*/
-static int
-H5FD_driver_query(const H5FD_class_t *driver, unsigned long *flags/*out*/)
-{
-    int ret_value = 0;          /* Return value */
-
-    FUNC_ENTER_NOAPI_NOINIT_NOERR
-
-    HDassert(driver);
-    HDassert(flags);
-
-    /* Check for the driver to query and then query it */
-    if(driver->query)
-        ret_value = (driver->query)(NULL, flags);
-    else 
-        *flags = 0;
-
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5FD_driver_query() */
-
-
-/*-------------------------------------------------------------------------
  * Function:	H5FDalloc
  *
  * Purpose:	Allocates SIZE bytes of memory from the FILE. The memory will
@@ -2076,3 +2040,42 @@ H5FD_set_paged_aggr(H5FD_t *file, hbool_t paged)
 
     FUNC_LEAVE_NOAPI(SUCCEED)
 } /* end H5FD_set_paged_aggr() */
+
+
+/*-------------------------------------------------------------------------
+* Function: H5FDdriver_query
+*
+* Purpose:  Similar to H5FD_query(), but intended for cases when we don't
+*           have a file available (e.g. before one is opened). Since we
+*           can't use the file to get the driver, the driver ID is passed
+*           in as a parameter.
+*
+* Return:   SUCCEED/FAIL
+*
+* Programmer:  Jacob Gruber
+*              Wednesday, August 17, 2011
+*
+*-------------------------------------------------------------------------
+*/
+herr_t
+H5FDdriver_query(hid_t driver_id, unsigned long *flags/*out*/)
+{
+    H5FD_class_t *driver = NULL;            /* Pointer to VFD class struct  */
+    herr_t ret_value = SUCCEED;             /* Return value                 */
+
+    FUNC_ENTER_API(FAIL)
+    H5TRACE2("e", "ix", driver_id, flags);
+
+    if(NULL == flags)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "flags parameter cannot be NULL")
+
+    /* Check for the driver to query and then query it */
+    if (NULL == (driver = (H5FD_class_t *)H5I_object_verify(driver_id, H5I_VFL)))
+        HGOTO_ERROR(H5E_ATOM, H5E_BADATOM, FAIL, "not a VFL ID")
+    if (H5FD_driver_query(driver, flags) < 0)
+        HGOTO_ERROR(H5E_VFL, H5E_BADVALUE, FAIL, "driver flag query failed")
+
+done:
+    FUNC_LEAVE_API(ret_value)
+} /* end H5FDdriver_query() */
+
diff --git a/src/H5FDcore.c b/src/H5FDcore.c
index d100a8b..b980b7e 100644
--- a/src/H5FDcore.c
+++ b/src/H5FDcore.c
@@ -982,9 +982,11 @@ H5FD__core_query(const H5FD_t * _file, unsigned long *flags /* out */)
         *flags |= H5FD_FEAT_ALLOW_FILE_IMAGE;               /* OK to use file image feature with this VFD                       */
         *flags |= H5FD_FEAT_CAN_USE_FILE_IMAGE_CALLBACKS;   /* OK to use file image callbacks with this VFD                     */
 
-        /* If the backing store is open, a POSIX file handle is available */
-        if(file && file->fd >= 0 && file->backing_store)
-            *flags |= H5FD_FEAT_POSIX_COMPAT_HANDLE; /* VFD handle is POSIX I/O call compatible */
+        /* These feature flags are only applicable if the backing store is enabled */
+        if(file && file->fd >= 0 && file->backing_store) {
+            *flags |= H5FD_FEAT_POSIX_COMPAT_HANDLE;        /* get_handle callback returns a POSIX file descriptor              */
+            *flags |= H5FD_FEAT_DEFAULT_VFD_COMPATIBLE;     /* VFD creates a file which can be opened with the default VFD      */
+        }
     } /* end if */
 
     FUNC_LEAVE_NOAPI(SUCCEED)
diff --git a/src/H5FDdirect.c b/src/H5FDdirect.c
index 1487cda..7a4c99c 100644
--- a/src/H5FDdirect.c
+++ b/src/H5FDdirect.c
@@ -698,6 +698,7 @@ H5FD_direct_query(const H5FD_t H5_ATTR_UNUSED * _f, unsigned long *flags /* out
         *flags |= H5FD_FEAT_ACCUMULATE_METADATA;    /* OK to accumulate metadata for faster writes                      */
         *flags |= H5FD_FEAT_DATA_SIEVE;             /* OK to perform data sieving for faster raw data reads & writes    */
         *flags |= H5FD_FEAT_AGGREGATE_SMALLDATA;    /* OK to aggregate "small" raw data allocations                     */
+        *flags |= H5FD_FEAT_DEFAULT_VFD_COMPATIBLE; /* VFD creates a file which can be opened with the default VFD      */
     }
 
     FUNC_LEAVE_NOAPI(SUCCEED)
diff --git a/src/H5FDint.c b/src/H5FDint.c
index bc322d6..52fbc23 100644
--- a/src/H5FDint.c
+++ b/src/H5FDint.c
@@ -433,3 +433,38 @@ done:
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5FD_get_eof() */
 
+
+/*-------------------------------------------------------------------------
+* Function:    H5FD_driver_query
+*
+* Purpose: Similar to H5FD_query(), but intended for cases when we don't
+*          have a file available (e.g. before one is opened). Since we
+*          can't use the file to get the driver, the driver is passed in
+*          as a parameter.
+*
+* Return:  SUCCEED/FAIL
+*
+* Programmer:  Jacob Gruber
+*              Wednesday, August 17, 2011
+*
+*-------------------------------------------------------------------------
+*/
+herr_t
+H5FD_driver_query(const H5FD_class_t *driver, unsigned long *flags/*out*/)
+{
+    herr_t ret_value = SUCCEED;          /* Return value */
+
+    FUNC_ENTER_NOAPI_NOINIT_NOERR
+
+    HDassert(driver);
+    HDassert(flags);
+
+    /* Check for the driver to query and then query it */
+    if(driver->query)
+        ret_value = (driver->query)(NULL, flags);
+    else 
+        *flags = 0;
+
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5FD_driver_query() */
+
diff --git a/src/H5FDlog.c b/src/H5FDlog.c
index 75333c2..7c6bbd4 100644
--- a/src/H5FDlog.c
+++ b/src/H5FDlog.c
@@ -895,8 +895,9 @@ H5FD_log_query(const H5FD_t *_file, unsigned long *flags /* out */)
         *flags |= H5FD_FEAT_ACCUMULATE_METADATA;    /* OK to accumulate metadata for faster writes                      */
         *flags |= H5FD_FEAT_DATA_SIEVE;             /* OK to perform data sieving for faster raw data reads & writes    */
         *flags |= H5FD_FEAT_AGGREGATE_SMALLDATA;    /* OK to aggregate "small" raw data allocations                     */
-        *flags |= H5FD_FEAT_POSIX_COMPAT_HANDLE;    /* VFD handle is POSIX I/O call compatible                          */
+        *flags |= H5FD_FEAT_POSIX_COMPAT_HANDLE;    /* get_handle callback returns a POSIX file descriptor              */
         *flags |= H5FD_FEAT_SUPPORTS_SWMR_IO;       /* VFD supports the single-writer/multiple-readers (SWMR) pattern   */
+        *flags |= H5FD_FEAT_DEFAULT_VFD_COMPATIBLE; /* VFD creates a file which can be opened with the default VFD      */
 
         /* Check for flags that are set by h5repart */
         if(file && file->fam_to_sec2)
diff --git a/src/H5FDmpio.c b/src/H5FDmpio.c
index ace91f8..f594d8e 100644
--- a/src/H5FDmpio.c
+++ b/src/H5FDmpio.c
@@ -1150,10 +1150,11 @@ H5FD_mpio_query(const H5FD_t H5_ATTR_UNUSED *_file, unsigned long *flags /* out
     /* Set the VFL feature flags that this driver supports */
     if(flags) {
         *flags=0;
-        *flags|=H5FD_FEAT_AGGREGATE_METADATA;  /* OK to aggregate metadata allocations */
-        *flags|=H5FD_FEAT_AGGREGATE_SMALLDATA; /* OK to aggregate "small" raw data allocations */
-        *flags|=H5FD_FEAT_HAS_MPI;             /* This driver uses MPI */
-        *flags|=H5FD_FEAT_ALLOCATE_EARLY;      /* Allocate space early instead of late */
+        *flags |= H5FD_FEAT_AGGREGATE_METADATA;     /* OK to aggregate metadata allocations                             */
+        *flags |= H5FD_FEAT_AGGREGATE_SMALLDATA;    /* OK to aggregate "small" raw data allocations                     */
+        *flags |= H5FD_FEAT_HAS_MPI;                /* This driver uses MPI                                             */
+        *flags |= H5FD_FEAT_ALLOCATE_EARLY;         /* Allocate space early instead of late                             */
+        *flags |= H5FD_FEAT_DEFAULT_VFD_COMPATIBLE; /* VFD creates a file which can be opened with the default VFD      */
     } /* end if */
 
     FUNC_LEAVE_NOAPI(SUCCEED)
diff --git a/src/H5FDprivate.h b/src/H5FDprivate.h
index 0fc2135..e758951 100644
--- a/src/H5FDprivate.h
+++ b/src/H5FDprivate.h
@@ -153,6 +153,7 @@ H5_DLL H5FD_t *H5FD_open(const char *name, unsigned flags, hid_t fapl_id,
 		  haddr_t maxaddr);
 H5_DLL herr_t H5FD_close(H5FD_t *file);
 H5_DLL int H5FD_cmp(const H5FD_t *f1, const H5FD_t *f2);
+H5_DLL herr_t H5FD_driver_query(const H5FD_class_t *driver, unsigned long *flags/*out*/);
 H5_DLL haddr_t H5FD_alloc(H5FD_t *file, hid_t dxpl_id, H5FD_mem_t type, 
     struct H5F_t *f, hsize_t size, haddr_t *frag_addr, hsize_t *frag_size);
 H5_DLL herr_t H5FD_free(H5FD_t *file, hid_t dxpl_id, H5FD_mem_t type, struct H5F_t *f,
diff --git a/src/H5FDpublic.h b/src/H5FDpublic.h
index 3032e8a..514d1bf 100644
--- a/src/H5FDpublic.h
+++ b/src/H5FDpublic.h
@@ -250,6 +250,14 @@ typedef enum H5F_mem_t	H5FD_mem_t;
      * This is specifically used for the multi/split driver.
      */
 #define H5FD_FEAT_PAGED_AGGR		0x00004000
+    /*
+     * Defining H5FD_FEAT_DEFAULT_VFD_COMPATIBLE for a VFL driver
+     * that creates a file which is compatible with the default VFD.
+     * Generally, this means that the VFD creates a single file that follows
+     * the canonical HDF5 file format.
+     */
+#define H5FD_FEAT_DEFAULT_VFD_COMPATIBLE        0x00008000
+
 
 /* Forward declaration */
 typedef struct H5FD_t H5FD_t;
@@ -376,6 +384,9 @@ H5_DLL herr_t H5FDtruncate(H5FD_t *file, hid_t dxpl_id, hbool_t closing);
 H5_DLL herr_t H5FDlock(H5FD_t *file, hbool_t rw);
 H5_DLL herr_t H5FDunlock(H5FD_t *file);
 
+/* Allows querying a VFD ID for features before the file is opened */
+H5_DLL herr_t H5FDdriver_query(hid_t driver_id, unsigned long *flags/*out*/);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/src/H5FDsec2.c b/src/H5FDsec2.c
index 26913e2..b6385fb 100644
--- a/src/H5FDsec2.c
+++ b/src/H5FDsec2.c
@@ -527,8 +527,9 @@ H5FD_sec2_query(const H5FD_t *_file, unsigned long *flags /* out */)
         *flags |= H5FD_FEAT_ACCUMULATE_METADATA;    /* OK to accumulate metadata for faster writes                      */
         *flags |= H5FD_FEAT_DATA_SIEVE;             /* OK to perform data sieving for faster raw data reads & writes    */
         *flags |= H5FD_FEAT_AGGREGATE_SMALLDATA;    /* OK to aggregate "small" raw data allocations                     */
-        *flags |= H5FD_FEAT_POSIX_COMPAT_HANDLE;    /* VFD handle is POSIX I/O call compatible                          */
+        *flags |= H5FD_FEAT_POSIX_COMPAT_HANDLE;    /* get_handle callback returns a POSIX file descriptor              */
         *flags |= H5FD_FEAT_SUPPORTS_SWMR_IO;       /* VFD supports the single-writer/multiple-readers (SWMR) pattern   */
+        *flags |= H5FD_FEAT_DEFAULT_VFD_COMPATIBLE; /* VFD creates a file which can be opened with the default VFD      */
 
         /* Check for flags that are set by h5repart */
         if(file && file->fam_to_sec2)
diff --git a/src/H5FDstdio.c b/src/H5FDstdio.c
index 5023af3..861c6a6 100644
--- a/src/H5FDstdio.c
+++ b/src/H5FDstdio.c
@@ -555,10 +555,11 @@ H5FD_stdio_query(const H5FD_t *_f, unsigned long /*OUT*/ *flags)
      */
     if(flags) {
         *flags = 0;
-        *flags|=H5FD_FEAT_AGGREGATE_METADATA; /* OK to aggregate metadata allocations */
-        *flags|=H5FD_FEAT_ACCUMULATE_METADATA; /* OK to accumulate metadata for faster writes */
-        *flags|=H5FD_FEAT_DATA_SIEVE;       /* OK to perform data sieving for faster raw data reads & writes */
-        *flags|=H5FD_FEAT_AGGREGATE_SMALLDATA; /* OK to aggregate "small" raw data allocations */
+        *flags |= H5FD_FEAT_AGGREGATE_METADATA;     /* OK to aggregate metadata allocations                             */
+        *flags |= H5FD_FEAT_ACCUMULATE_METADATA;    /* OK to accumulate metadata for faster writes                      */
+        *flags |= H5FD_FEAT_DATA_SIEVE;             /* OK to perform data sieving for faster raw data reads & writes    */
+        *flags |= H5FD_FEAT_AGGREGATE_SMALLDATA;    /* OK to aggregate "small" raw data allocations                     */
+        *flags |= H5FD_FEAT_DEFAULT_VFD_COMPATIBLE; /* VFD creates a file which can be opened with the default VFD      */
     }
 
     return 0;
diff --git a/src/H5Fint.c b/src/H5Fint.c
index fe532b2..e52d539 100644
--- a/src/H5Fint.c
+++ b/src/H5Fint.c
@@ -715,10 +715,6 @@ H5F_new(H5F_file_t *shared, unsigned flags, hid_t fcpl_id, hid_t fapl_id, H5FD_t
         if(!H5F_HAS_FEATURE(f, H5FD_FEAT_SUPPORTS_SWMR_IO) && (H5F_INTENT(f) & (H5F_ACC_SWMR_WRITE | H5F_ACC_SWMR_READ)))
             HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, NULL, "must use a SWMR-compatible VFD when SWMR is specified")
 
-        /* Require a POSIX compatible VFD to use SWMR feature */
-        /* (It's reasonable to try to expand this to other VFDs eventually -QAK) */
-        if(!H5F_HAS_FEATURE(f, H5FD_FEAT_POSIX_COMPAT_HANDLE) && (H5F_INTENT(f) & (H5F_ACC_SWMR_WRITE | H5F_ACC_SWMR_READ)))
-            HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, NULL, "must use POSIX compatible VFD with SWMR write access")
         if(H5FD_get_fs_type_map(lf, f->shared->fs_type_map) < 0)
             HGOTO_ERROR(H5E_FILE, H5E_CANTGET, NULL, "can't get free space type mapping from VFD")
         if(H5MF_init_merge_flags(f) < 0)
diff --git a/src/H5I.c b/src/H5I.c
index ce4ecdc..42edf58 100644
--- a/src/H5I.c
+++ b/src/H5I.c
@@ -888,7 +888,7 @@ H5I_subst(hid_t id, const void *new_object)
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
-} /* end if */
+} /* end H5I_subst() */
 
 
 /*-------------------------------------------------------------------------
@@ -920,7 +920,7 @@ H5I_object(hid_t id)
     } /* end if */
 
     FUNC_LEAVE_NOAPI(ret_value)
-} /* end if */
+} /* end H5I_object() */
 
 
 /*-------------------------------------------------------------------------
diff --git a/test/swmr.c b/test/swmr.c
index 399a9ec..3b1bd09 100644
--- a/test/swmr.c
+++ b/test/swmr.c
@@ -116,16 +116,37 @@ static int test_multiple_same(hid_t in_fapl, hbool_t new_format);
 static int
 test_metadata_read_attempts(hid_t in_fapl)
 {
-    hid_t fapl;             /* File access property list */
-    hid_t file_fapl;            /* The file's access property list */
-    hid_t fid, fid1, fid2;          /* File IDs */
-    unsigned attempts;          /* The # of read attempts */
-    char filename[NAME_BUF_SIZE];       /* File name */
-    herr_t ret;                 /* Generic return value */
+    hid_t fapl = -1;                        /* File access property list            */
+    hid_t file_fapl = -1;                   /* The file's access property list      */
+    hid_t fid = -1, fid1 = -1, fid2 = -1;   /* File IDs                             */
+    hid_t driver_id = -1;                   /* ID for this VFD                      */
+    unsigned long driver_flags = 0;         /* VFD feature flags                    */
+    hbool_t compat_w_default_vfd;           /* current VFD compat w/ H5P_DEFAULT?   */
+    unsigned attempts;                      /* The # of read attempts               */
+    char filename[NAME_BUF_SIZE];           /* File name                            */
+    herr_t ret;                             /* Generic return value                 */
 
     /* Output message about test being performed */
     TESTING("H5Pget/set_metadata_read_attempts()");
 
+    /* Check if the driver is compatible with the default VFD.
+     * Most of the tests will attempt to create and open files with both the
+     * VFD specified in the passed-in fapl and the default VFD. Since this
+     * will clearly not work with VFDs that are not compatible with the default
+     * fapl (e.g.: split/multi), we just skip this entire test.
+     */
+    if ((driver_id = H5Pget_driver(in_fapl)) < 0)
+        FAIL_STACK_ERROR
+    if (H5FDdriver_query(driver_id, &driver_flags) < 0)
+        FAIL_STACK_ERROR
+    compat_w_default_vfd = (driver_flags & H5FD_FEAT_DEFAULT_VFD_COMPATIBLE) ? TRUE : FALSE;
+
+    if (!compat_w_default_vfd) {
+        SKIPPED()
+        HDputs("    The current VFD is not compatible with the default VFD.");
+        return 0;
+    }
+
     /* Get a copy of the parameter fapl */
     if((fapl = H5Pcopy(in_fapl)) < 0)
         FAIL_STACK_ERROR
diff --git a/test/vfd.c b/test/vfd.c
index 1932d2c..f8e5761 100644
--- a/test/vfd.c
+++ b/test/vfd.c
@@ -86,6 +86,8 @@ test_sec2(void)
     hid_t       fid = -1;                   /* file ID                      */
     hid_t       fapl_id = -1;               /* file access property list ID */
     hid_t       fapl_id_out = -1;           /* from H5Fget_access_plist     */
+    hid_t       driver_id = -1;             /* ID for this VFD              */
+    unsigned long driver_flags = 0;         /* VFD feature flags            */
     char        filename[1024];             /* filename                     */
     void        *os_file_handle = NULL;     /* OS file handle               */
     hsize_t     file_size;                  /* file size                    */
@@ -99,6 +101,28 @@ test_sec2(void)
         TEST_ERROR;
     h5_fixname(FILENAME[0], fapl_id, filename, sizeof(filename));
 
+    /* Check that the VFD feature flags are correct */
+    if ((driver_id = H5Pget_driver(fapl_id)) < 0)
+        TEST_ERROR
+    if (H5FDdriver_query(driver_id, &driver_flags) < 0)
+        TEST_ERROR
+    if(!(driver_flags & H5FD_FEAT_AGGREGATE_METADATA))      TEST_ERROR
+    if(!(driver_flags & H5FD_FEAT_ACCUMULATE_METADATA))     TEST_ERROR
+    if(!(driver_flags & H5FD_FEAT_DATA_SIEVE))              TEST_ERROR
+    if(!(driver_flags & H5FD_FEAT_AGGREGATE_SMALLDATA))     TEST_ERROR
+    if(!(driver_flags & H5FD_FEAT_POSIX_COMPAT_HANDLE))     TEST_ERROR
+    if(!(driver_flags & H5FD_FEAT_SUPPORTS_SWMR_IO))        TEST_ERROR
+    if(!(driver_flags & H5FD_FEAT_DEFAULT_VFD_COMPATIBLE))  TEST_ERROR
+    /* Check for extra flags not accounted for above */
+    if(driver_flags != (H5FD_FEAT_AGGREGATE_METADATA
+                        | H5FD_FEAT_ACCUMULATE_METADATA
+                        | H5FD_FEAT_DATA_SIEVE
+                        | H5FD_FEAT_AGGREGATE_SMALLDATA
+                        | H5FD_FEAT_POSIX_COMPAT_HANDLE
+                        | H5FD_FEAT_SUPPORTS_SWMR_IO
+                        | H5FD_FEAT_DEFAULT_VFD_COMPATIBLE))
+        TEST_ERROR
+
     if((fid = H5Fcreate(filename, H5F_ACC_TRUNC, H5P_DEFAULT, fapl_id)) < 0)
         TEST_ERROR;
 
@@ -174,6 +198,8 @@ test_core(void)
     hid_t       fid = -1;                   /* file ID                      */
     hid_t       fapl_id = -1;               /* file access property list ID */
     hid_t       fapl_id_out = -1;           /* from H5Fget_access_plist     */
+    hid_t       driver_id = -1;             /* ID for this VFD              */
+    unsigned long driver_flags = 0;         /* VFD feature flags            */
     hid_t       did = -1;                   /* dataset ID                   */
     hid_t       sid = -1;                   /* dataspace ID                 */
     char        filename[1024];             /* filename                     */
@@ -208,9 +234,34 @@ test_core(void)
     if(HDaccess(filename, F_OK) != -1)
         if(HDremove(filename) < 0)
             FAIL_PUTS_ERROR("unable to remove backing store file");
+
     /* Create and close file w/ backing store off */
     if(H5Pset_fapl_core(fapl_id, (size_t)CORE_INCREMENT, FALSE) < 0)
         TEST_ERROR;
+
+    /* Check that the VFD feature flags are correct.
+     * Note that the H5FDdriver_query() API call does not require a file
+     * so backing-store related flags will not be returned here.
+     */
+    if ((driver_id = H5Pget_driver(fapl_id)) < 0)
+        TEST_ERROR
+    if (H5FDdriver_query(driver_id, &driver_flags) < 0)
+        TEST_ERROR
+    if(!(driver_flags & H5FD_FEAT_AGGREGATE_METADATA))              TEST_ERROR
+    if(!(driver_flags & H5FD_FEAT_ACCUMULATE_METADATA))             TEST_ERROR
+    if(!(driver_flags & H5FD_FEAT_DATA_SIEVE))                      TEST_ERROR
+    if(!(driver_flags & H5FD_FEAT_AGGREGATE_SMALLDATA))             TEST_ERROR
+    if(!(driver_flags & H5FD_FEAT_ALLOW_FILE_IMAGE))                TEST_ERROR
+    if(!(driver_flags & H5FD_FEAT_CAN_USE_FILE_IMAGE_CALLBACKS))    TEST_ERROR
+    /* Check for extra flags not accounted for above */
+    if(driver_flags != (H5FD_FEAT_AGGREGATE_METADATA
+                        | H5FD_FEAT_ACCUMULATE_METADATA
+                        | H5FD_FEAT_DATA_SIEVE
+                        | H5FD_FEAT_AGGREGATE_SMALLDATA
+                        | H5FD_FEAT_ALLOW_FILE_IMAGE 
+                        | H5FD_FEAT_CAN_USE_FILE_IMAGE_CALLBACKS))
+        TEST_ERROR
+
     if((fid = H5Fcreate(filename, H5F_ACC_TRUNC, H5P_DEFAULT, fapl_id)) < 0)
         TEST_ERROR;
     if(H5Fclose(fid) < 0)
@@ -219,7 +270,6 @@ test_core(void)
     if(HDaccess(filename, F_OK) != -1)
         FAIL_PUTS_ERROR("file created when backing store set to FALSE");
 
-
     /************************************************************************
      * Check basic core VFD operation and properties. This is done with the
      * backing store on so a file will be created for later use.
@@ -795,6 +845,8 @@ test_family(void)
 {
     hid_t       file=-1, fapl=-1, fapl2=-1, space=-1, dset=-1;
     hid_t       access_fapl = -1;
+    hid_t       driver_id = -1;             /* ID for this VFD              */
+    unsigned long driver_flags = 0;         /* VFD feature flags            */
     char        filename[1024];
     char        dname[]="dataset";
     unsigned int i, j;
@@ -812,6 +864,22 @@ test_family(void)
         TEST_ERROR;
     h5_fixname(FILENAME[2], fapl, filename, sizeof(filename));
 
+    /* Check that the VFD feature flags are correct */
+    if ((driver_id = H5Pget_driver(fapl)) < 0)
+        TEST_ERROR
+    if (H5FDdriver_query(driver_id, &driver_flags) < 0)
+        TEST_ERROR
+    if(!(driver_flags & H5FD_FEAT_AGGREGATE_METADATA))      TEST_ERROR
+    if(!(driver_flags & H5FD_FEAT_ACCUMULATE_METADATA))     TEST_ERROR
+    if(!(driver_flags & H5FD_FEAT_DATA_SIEVE))              TEST_ERROR
+    if(!(driver_flags & H5FD_FEAT_AGGREGATE_SMALLDATA))     TEST_ERROR
+    /* Check for extra flags not accounted for above */
+    if(driver_flags != (H5FD_FEAT_AGGREGATE_METADATA
+                        | H5FD_FEAT_ACCUMULATE_METADATA
+                        | H5FD_FEAT_DATA_SIEVE
+                        | H5FD_FEAT_AGGREGATE_SMALLDATA))
+        TEST_ERROR
+
     if((file=H5Fcreate(filename, H5F_ACC_TRUNC, H5P_DEFAULT, fapl)) < 0)
         TEST_ERROR;
 
@@ -1096,6 +1164,8 @@ test_multi(void)
     hid_t       file=-1, fapl=-1, fapl2=-1, dset=-1, space=-1;
     hid_t       root=-1, attr=-1, aspace=-1, atype=-1;
     hid_t       access_fapl = -1;
+    hid_t       driver_id = -1;             /* ID for this VFD              */
+    unsigned long driver_flags = 0;         /* VFD feature flags            */
     char        filename[1024];
     int         *fhandle2=NULL, *fhandle=NULL;
     hsize_t     file_size;
@@ -1152,6 +1222,22 @@ test_multi(void)
         TEST_ERROR;
     h5_fixname(FILENAME[4], fapl, filename, sizeof filename);
 
+    /* Check that the VFD feature flags are correct */
+    if ((driver_id = H5Pget_driver(fapl)) < 0)
+        TEST_ERROR
+    if (H5FDdriver_query(driver_id, &driver_flags) < 0)
+        TEST_ERROR
+    if(!(driver_flags & H5FD_FEAT_DATA_SIEVE))              TEST_ERROR
+    if(!(driver_flags & H5FD_FEAT_AGGREGATE_SMALLDATA))     TEST_ERROR
+    if(!(driver_flags & H5FD_FEAT_USE_ALLOC_SIZE))          TEST_ERROR
+    if(!(driver_flags & H5FD_FEAT_PAGED_AGGR))              TEST_ERROR
+    /* Check for extra flags not accounted for above */
+    if(driver_flags != (H5FD_FEAT_DATA_SIEVE
+                        | H5FD_FEAT_AGGREGATE_SMALLDATA
+                        | H5FD_FEAT_USE_ALLOC_SIZE
+                        | H5FD_FEAT_PAGED_AGGR))
+        TEST_ERROR
+
     if((file=H5Fcreate(filename, H5F_ACC_TRUNC, H5P_DEFAULT, fapl)) < 0)
         TEST_ERROR;
 
@@ -1484,6 +1570,8 @@ test_log(void)
     hid_t        file            = -1;
     hid_t        fapl            = -1;
     hid_t        access_fapl     = -1;
+    hid_t       driver_id = -1;             /* ID for this VFD              */
+    unsigned long driver_flags = 0;         /* VFD feature flags            */
     char         filename[1024];
     int          *fhandle        = NULL;
     hsize_t      file_size       = 0;
@@ -1499,6 +1587,28 @@ test_log(void)
         TEST_ERROR;
     h5_fixname(FILENAME[6], fapl, filename, sizeof filename);
 
+    /* Check that the VFD feature flags are correct */
+    if ((driver_id = H5Pget_driver(fapl)) < 0)
+        TEST_ERROR
+    if (H5FDdriver_query(driver_id, &driver_flags) < 0)
+        TEST_ERROR
+    if(!(driver_flags & H5FD_FEAT_AGGREGATE_METADATA))      TEST_ERROR
+    if(!(driver_flags & H5FD_FEAT_ACCUMULATE_METADATA))     TEST_ERROR
+    if(!(driver_flags & H5FD_FEAT_DATA_SIEVE))              TEST_ERROR
+    if(!(driver_flags & H5FD_FEAT_AGGREGATE_SMALLDATA))     TEST_ERROR
+    if(!(driver_flags & H5FD_FEAT_POSIX_COMPAT_HANDLE))     TEST_ERROR
+    if(!(driver_flags & H5FD_FEAT_SUPPORTS_SWMR_IO))        TEST_ERROR
+    if(!(driver_flags & H5FD_FEAT_DEFAULT_VFD_COMPATIBLE))  TEST_ERROR
+    /* Check for extra flags not accounted for above */
+    if(driver_flags != (H5FD_FEAT_AGGREGATE_METADATA
+                        | H5FD_FEAT_ACCUMULATE_METADATA
+                        | H5FD_FEAT_DATA_SIEVE
+                        | H5FD_FEAT_AGGREGATE_SMALLDATA
+                        | H5FD_FEAT_POSIX_COMPAT_HANDLE
+                        | H5FD_FEAT_SUPPORTS_SWMR_IO
+                        | H5FD_FEAT_DEFAULT_VFD_COMPATIBLE))
+        TEST_ERROR
+
     /* Create the test file */
     if((file = H5Fcreate(filename, H5F_ACC_TRUNC, H5P_DEFAULT, fapl)) < 0)
         TEST_ERROR;
@@ -1571,6 +1681,8 @@ test_stdio(void)
     hid_t        file            = -1;
     hid_t        fapl            = -1;
     hid_t        access_fapl     = -1;
+    hid_t       driver_id = -1;             /* ID for this VFD              */
+    unsigned long driver_flags = 0;         /* VFD feature flags            */
     char         filename[1024];
     FILE         *fhandle        = NULL;
     hsize_t      file_size       = 0;
@@ -1584,6 +1696,24 @@ test_stdio(void)
         TEST_ERROR;
     h5_fixname(FILENAME[7], fapl, filename, sizeof filename);
 
+    /* Check that the VFD feature flags are correct */
+    if ((driver_id = H5Pget_driver(fapl)) < 0)
+        TEST_ERROR
+    if (H5FDdriver_query(driver_id, &driver_flags) < 0)
+        TEST_ERROR
+    if(!(driver_flags & H5FD_FEAT_AGGREGATE_METADATA))      TEST_ERROR
+    if(!(driver_flags & H5FD_FEAT_ACCUMULATE_METADATA))     TEST_ERROR
+    if(!(driver_flags & H5FD_FEAT_DATA_SIEVE))              TEST_ERROR
+    if(!(driver_flags & H5FD_FEAT_AGGREGATE_SMALLDATA))     TEST_ERROR
+    if(!(driver_flags & H5FD_FEAT_DEFAULT_VFD_COMPATIBLE))  TEST_ERROR
+    /* Check for extra flags not accounted for above */
+    if(driver_flags != (H5FD_FEAT_AGGREGATE_METADATA
+                        | H5FD_FEAT_ACCUMULATE_METADATA
+                        | H5FD_FEAT_DATA_SIEVE
+                        | H5FD_FEAT_AGGREGATE_SMALLDATA
+                        | H5FD_FEAT_DEFAULT_VFD_COMPATIBLE))
+        TEST_ERROR
+
     if((file = H5Fcreate(filename, H5F_ACC_TRUNC, H5P_DEFAULT, fapl)) < 0)
         TEST_ERROR;
 
@@ -1658,6 +1788,8 @@ test_windows(void)
     hid_t        file            = -1;
     hid_t        fapl            = -1;
     hid_t        access_fapl     = -1;
+    hid_t       driver_id = -1;             /* ID for this VFD              */
+    unsigned long driver_flags = 0;         /* VFD feature flags            */
     char         filename[1024];
     int          *fhandle        = NULL;
     hsize_t      file_size       = 0;
@@ -1680,6 +1812,28 @@ test_windows(void)
         TEST_ERROR;
     h5_fixname(FILENAME[8], fapl, filename, sizeof filename);
 
+    /* Check that the VFD feature flags are correct */
+    if ((driver_id = H5Pget_driver(fapl_id)) < 0)
+        TEST_ERROR
+    if (H5FDdriver_query(driver_id, &driver_flags) < 0)
+        TEST_ERROR
+    if(!(driver_flags & H5FD_FEAT_AGGREGATE_METADATA))      TEST_ERROR
+    if(!(driver_flags & H5FD_FEAT_ACCUMULATE_METADATA))     TEST_ERROR
+    if(!(driver_flags & H5FD_FEAT_DATA_SIEVE))              TEST_ERROR
+    if(!(driver_flags & H5FD_FEAT_AGGREGATE_SMALLDATA))     TEST_ERROR
+    if(!(driver_flags & H5FD_FEAT_POSIX_COMPAT_HANDLE))     TEST_ERROR
+    if(!(driver_flags & H5FD_FEAT_SUPPORTS_SWMR_IO))        TEST_ERROR
+    if(!(driver_flags & H5FD_FEAT_DEFAULT_VFD_COMPATIBLE))  TEST_ERROR
+    /* Check for extra flags not accounted for above */
+    if(driver_flags != (H5FD_FEAT_AGGREGATE_METADATA
+                        | H5FD_FEAT_ACCUMULATE_METADATA
+                        | H5FD_FEAT_DATA_SIEVE
+                        | H5FD_FEAT_AGGREGATE_SMALLDATA
+                        | H5FD_FEAT_POSIX_COMPAT_HANDLE
+                        | H5FD_FEAT_SUPPORTS_SWMR_IO
+                        | H5FD_FEAT_DEFAULT_VFD_COMPATIBLE))
+        TEST_ERROR
+
     if((file = H5Fcreate(filename, H5F_ACC_TRUNC, H5P_DEFAULT, fapl)) < 0)
         TEST_ERROR;