Merge pull request #17 in ~VCHOI/my_third_fork from develop to bugfix/HDFFV-10813-swmr-test-fails-on-jelly-with

* commit '3a504899eef1a66031c6f52623c24bb4e51ca51e':
  Correct name of folder
  Mostly whitespace in testpar, addl changes for tmp dir
  Whitespace cleanup
  Added public H5Sselect_adjust_u and H5Shyper_adjust_s calls.
  Some refactoring prior to implementing new H5P MPI functions. * Macro cleanup and obvious warning fixes in parallel code. * Moved H5FD comm and info dup/free wrapper code to a new H5mpi.c file   and separated it to deal with each MPI type separately.
  Fix compiler warnings with diabled ROS3 and HDFS VFDs. Fix misuse of [HD]strncpy and [HD]snprintf. Minor formatting changes. Fix test cleanup issue with java groups example.
  Changed the directory name left out from the previous commit.
  Changed the name of the temporary directory from 'tmp' to a special name to avoid possible conflicts.
  Fix H5F_get_file_id and H5F__get_file_id to take app_ref parameter
  HDFFV-10879 fix test varname

21 files changed, 1690 insertions, 1202 deletions

diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 17fd949..313d231 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -8,6 +8,7 @@ set (H5_SOURCES
     ${HDF5_SRC_DIR}/H5.c
     ${HDF5_SRC_DIR}/H5checksum.c
     ${HDF5_SRC_DIR}/H5dbg.c
+    ${HDF5_SRC_DIR}/H5mpi.c
     ${HDF5_SRC_DIR}/H5system.c
     ${HDF5_SRC_DIR}/H5timer.c
     ${HDF5_SRC_DIR}/H5trace.c
diff --git a/src/H5ACmpio.c b/src/H5ACmpio.c
index b60b933..e4b81fa 100644
--- a/src/H5ACmpio.c
+++ b/src/H5ACmpio.c
@@ -821,9 +821,8 @@ H5AC__log_cleaned_entry(const H5AC_info_t *entry_ptr)
 {
     H5AC_t             * cache_ptr;
     H5AC_aux_t         * aux_ptr;
-    herr_t               ret_value = SUCCEED;    /* Return value */
 
-    FUNC_ENTER_PACKAGE
+    FUNC_ENTER_PACKAGE_NOERR
 
     /* Sanity check */
     HDassert(entry_ptr);
@@ -853,8 +852,7 @@ H5AC__log_cleaned_entry(const H5AC_info_t *entry_ptr)
     /* Decrement the dirty byte count */
     aux_ptr->dirty_bytes -= entry_ptr->size;
 
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
+    FUNC_LEAVE_NOAPI(SUCCEED)
 } /* H5AC__log_cleaned_entry() */
 
 
diff --git a/src/H5FDhdfs.c b/src/H5FDhdfs.c
index e3e11b2..83d0202 100644
--- a/src/H5FDhdfs.c
+++ b/src/H5FDhdfs.c
@@ -130,6 +130,8 @@ typedef struct {
 
 #endif /* HDFS_STATS */
 
+#ifdef H5_HAVE_LIBHDFS
+
 /* "unique" identifier for `hdfs_t` structures.
  * Randomly generated by unweighted dice rolls.
  */
@@ -143,7 +145,7 @@ typedef struct {
  * Purpose:
  *
  *     Contain/retain information associated with a file hosted on Hadoop
- *     Distributed File System (HDFS). Instantiated and populated via 
+ *     Distributed File System (HDFS). Instantiated and populated via
  *     `H5FD_hdfs_handle_open()` and cleaned up via `H5FD_hdfs_handle_close()`.
  *
  *
@@ -179,14 +181,11 @@ typedef struct {
  */
 typedef struct {
     unsigned long  magic;
-#ifdef H5_HAVE_LIBHDFS
     hdfsFS         filesystem;
     hdfsFileInfo  *fileinfo;
-    hdfsFile       file; 
-#endif
+    hdfsFile       file;
 } hdfs_t;
 
-#ifdef H5_HAVE_LIBHDFS
 
 /*--------------------------------------------------------------------------
  * Function:   H5FD_hdfs_handle_open
@@ -274,7 +273,7 @@ H5FD_hdfs_handle_open(
                     "hdfsGetPathInfo failed")
     }
     handle->file = hdfsOpenFile(
-            handle->filesystem, 
+            handle->filesystem,
             path,
             O_RDONLY,
             stream_buffer_size,
@@ -292,18 +291,18 @@ done:
         /* error; clean up */
         HDassert(handle->magic == HDFS_HDFST_MAGIC);
         handle->magic++;
-        if (handle->file != NULL) { 
+        if (handle->file != NULL) {
             if (FAIL == (hdfsCloseFile(handle->filesystem, handle->file))) {
-                HDONE_ERROR(H5E_VFL, H5E_CANTCLOSEFILE, NULL, 
+                HDONE_ERROR(H5E_VFL, H5E_CANTCLOSEFILE, NULL,
                             "unable to close hdfs file handle")
             }
         }
-        if (handle->fileinfo != NULL) { 
+        if (handle->fileinfo != NULL) {
             hdfsFreeFileInfo(handle->fileinfo, 1);
         }
-        if (handle->filesystem != NULL) { 
+        if (handle->filesystem != NULL) {
             if (FAIL == (hdfsDisconnect(handle->filesystem))) {
-                HDONE_ERROR(H5E_VFL, H5E_CANTCLOSEFILE, NULL, 
+                HDONE_ERROR(H5E_VFL, H5E_CANTCLOSEFILE, NULL,
                             "unable to disconnect from hdfs")
             }
         }
@@ -351,18 +350,18 @@ H5FD_hdfs_handle_close(hdfs_t *handle)
     }
 
     handle->magic++;
-    if (handle->file != NULL) { 
+    if (handle->file != NULL) {
         if (FAIL == (hdfsCloseFile(handle->filesystem, handle->file))) {
-            HDONE_ERROR(H5E_VFL, H5E_CANTCLOSEFILE, FAIL, 
+            HDONE_ERROR(H5E_VFL, H5E_CANTCLOSEFILE, FAIL,
                         "unable to close hdfs file handle")
         }
     }
-    if (handle->fileinfo != NULL) { 
+    if (handle->fileinfo != NULL) {
         hdfsFreeFileInfo(handle->fileinfo, 1);
     }
-    if (handle->filesystem != NULL) { 
+    if (handle->filesystem != NULL) {
         if (FAIL == (hdfsDisconnect(handle->filesystem))) {
-            HDONE_ERROR(H5E_VFL, H5E_CANTCLOSEFILE, FAIL, 
+            HDONE_ERROR(H5E_VFL, H5E_CANTCLOSEFILE, FAIL,
                         "unable to disconnect hdfs file system")
         }
     }
@@ -373,6 +372,7 @@ done:
     FUNC_LEAVE_NOAPI(ret_value)
 
 } /* H5FD_hdfs_close() */
+
 #endif /* H5_HAVE_LIBHDFS */
 
 
@@ -382,9 +382,9 @@ done:
  *
  * Purpose:
  *
- *     H5FD_hdfs_t is a structure used to store all information needed to 
+ *     H5FD_hdfs_t is a structure used to store all information needed to
  *     maintain R/O access to a single HDF5 file in an HDFS file system.
- *     This structure is created when such a file is "opened" and 
+ *     This structure is created when such a file is "opened" and
  *     discarded when it is "closed".
  *
  *
@@ -396,7 +396,7 @@ done:
  *
  * `fa` (H5FD_hdfs_fapl_t)
  *
- *     Instance of `H5FD_hdfs_fapl_t` containing the HDFS configuration data 
+ *     Instance of `H5FD_hdfs_fapl_t` containing the HDFS configuration data
  *     needed to "open" the HDF5 file.
  *
  * `eoa` (haddr_t)
@@ -405,9 +405,9 @@ done:
  *     equal the file size.
  *
  * `hdfs_handle` (hdfs_t *)
- *     
+ *
  *     Instance of HDFS Request handle associated with the target resource.
- *     Responsible for communicating with remote host and presenting file 
+ *     Responsible for communicating with remote host and presenting file
  *     contents as indistinguishable from a file on the local filesystem.
  *
  * *** present only if HDFS_SATS is flagged to enable stats collection ***
@@ -456,10 +456,13 @@ typedef struct H5FD_hdfs_t {
  * ADDR_OVERFLOW:   Checks whether a file address of type `haddr_t'
  *                  is too large to be represented by the second argument
  *                  of the file seek function.
+ *                  Only included if HDFS code should compile.
  *
  */
 #define MAXADDR (((haddr_t)1<<(8*sizeof(HDoff_t)-1))-1)
+#ifdef H5_HAVE_LIBHDFS
 #define ADDR_OVERFLOW(A)    (HADDR_UNDEF==(A) || ((A) & ~(haddr_t)MAXADDR))
+#endif /* H5_HAVE_LIBHDFS */
 
 /* Prototypes */
 static herr_t  H5FD_hdfs_term(void);
@@ -474,13 +477,13 @@ static herr_t  H5FD_hdfs_query(const H5FD_t *_f1, unsigned long *flags);
 static haddr_t H5FD_hdfs_get_eoa(const H5FD_t *_file, H5FD_mem_t type);
 static herr_t  H5FD_hdfs_set_eoa(H5FD_t *_file, H5FD_mem_t type, haddr_t addr);
 static haddr_t H5FD_hdfs_get_eof(const H5FD_t *_file, H5FD_mem_t type);
-static herr_t  H5FD_hdfs_get_handle(H5FD_t *_file, hid_t fapl, 
+static herr_t  H5FD_hdfs_get_handle(H5FD_t *_file, hid_t fapl,
                                     void** file_handle);
-static herr_t  H5FD_hdfs_read(H5FD_t *_file, H5FD_mem_t type, hid_t fapl_id, 
+static herr_t  H5FD_hdfs_read(H5FD_t *_file, H5FD_mem_t type, hid_t fapl_id,
                                haddr_t addr, size_t size, void *buf);
-static herr_t  H5FD_hdfs_write(H5FD_t *_file, H5FD_mem_t type, hid_t fapl_id, 
+static herr_t  H5FD_hdfs_write(H5FD_t *_file, H5FD_mem_t type, hid_t fapl_id,
                                haddr_t addr, size_t size, const void *buf);
-static herr_t  H5FD_hdfs_truncate(H5FD_t *_file, hid_t dxpl_id, 
+static herr_t  H5FD_hdfs_truncate(H5FD_t *_file, hid_t dxpl_id,
                                   hbool_t closing);
 static herr_t  H5FD_hdfs_lock(H5FD_t *_file, hbool_t rw);
 static herr_t  H5FD_hdfs_unlock(H5FD_t *_file);
@@ -521,8 +524,10 @@ static const H5FD_class_t H5FD_hdfs_g = {
     H5FD_FLMAP_DICHOTOMY        /* fl_map               */
 };
 
+#ifdef H5_HAVE_LIBHDFS
 /* Declare a free list to manage the H5FD_hdfs_t struct */
 H5FL_DEFINE_STATIC(H5FD_hdfs_t);
+#endif /* H5_HAVE_LIBHDFS */
 
 
 /*-------------------------------------------------------------------------
@@ -545,7 +550,7 @@ H5FD__init_package(void)
     FUNC_ENTER_STATIC
 
     if (H5FD_hdfs_init() < 0) {
-        HGOTO_ERROR(H5E_VFL, H5E_CANTINIT, FAIL, 
+        HGOTO_ERROR(H5E_VFL, H5E_CANTINIT, FAIL,
                     "unable to initialize hdfs VFD")
     }
 
@@ -643,8 +648,8 @@ H5FD_hdfs_term(void)
  * Function:    H5Pset_fapl_hdfs
  *
  * Purpose:     Modify the file access property list to use the H5FD_HDFS
- *              driver defined in this source file.  All driver specfic 
- *              properties are passed in as a pointer to a suitably 
+ *              driver defined in this source file.  All driver specfic
+ *              properties are passed in as a pointer to a suitably
  *              initialized instance of H5FD_hdfs_fapl_t
  *
  * Return:      SUCCEED/FAIL
@@ -658,7 +663,7 @@ H5FD_hdfs_term(void)
  *-------------------------------------------------------------------------
  */
 herr_t
-H5Pset_fapl_hdfs(hid_t             fapl_id, 
+H5Pset_fapl_hdfs(hid_t             fapl_id,
                  H5FD_hdfs_fapl_t *fa)
 {
     H5P_genplist_t *plist     = NULL; /* Property list pointer */
@@ -674,7 +679,7 @@ H5Pset_fapl_hdfs(hid_t             fapl_id,
 #endif
 
     plist = H5P_object_verify(fapl_id, H5P_FILE_ACCESS);
-    if (plist == NULL) { 
+    if (plist == NULL) {
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, \
                     "not a file access property list")
     }
@@ -699,12 +704,12 @@ done:
  *              contains internally consistant data.  Return SUCCEED if so,
  *              and FAIL otherwise.
  *
- *              Note the difference between internally consistant and 
- *              correct.  As we will have to try to access the target 
+ *              Note the difference between internally consistant and
+ *              correct.  As we will have to try to access the target
  *              object to determine whether the supplied data is correct,
  *              we will settle for internal consistancy at this point
  *
- * Return:      SUCCEED if instance of H5FD_hdfs_fapl_t contains internally 
+ * Return:      SUCCEED if instance of H5FD_hdfs_fapl_t contains internally
  *              consistant data, FAIL otherwise.
  *
  * Programmer:  Jacob Smith
@@ -761,7 +766,7 @@ done:
  *-------------------------------------------------------------------------
  */
 herr_t
-H5Pget_fapl_hdfs(hid_t             fapl_id, 
+H5Pget_fapl_hdfs(hid_t             fapl_id,
                  H5FD_hdfs_fapl_t *fa_out)
 {
     const H5FD_hdfs_fapl_t *fa        = NULL;
@@ -832,7 +837,7 @@ H5FD_hdfs_fapl_get(H5FD_t *_file)
 
     fa = (H5FD_hdfs_fapl_t *)H5MM_calloc(sizeof(H5FD_hdfs_fapl_t));
     if (fa == NULL) {
-        HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, 
+        HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL,
                     "memory allocation failed")
     }
 
@@ -878,7 +883,7 @@ H5FD_hdfs_fapl_copy(const void *_old_fa)
 
     new_fa = (H5FD_hdfs_fapl_t *)H5MM_malloc(sizeof(H5FD_hdfs_fapl_t));
     if (new_fa == NULL) {
-        HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, 
+        HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL,
                     "memory allocation failed")
     }
 
@@ -916,7 +921,7 @@ H5FD_hdfs_fapl_free(void *_fa)
 
     FUNC_ENTER_NOAPI_NOINIT_NOERR
 
-    HDassert(fa != NULL); /* sanity check */ 
+    HDassert(fa != NULL); /* sanity check */
 
     H5MM_xfree(fa);
 
@@ -994,11 +999,11 @@ done:
  *     Create and/or opens a file as an HDF5 file.
  *
  *     Any flag except H5F_ACC_RDONLY will cause an error.
- * 
+ *
  * Return:
  *
- *     Success: A pointer to a new file data structure. 
- *              The public fields will be initialized by the caller, which is 
+ *     Success: A pointer to a new file data structure.
+ *              The public fields will be initialized by the caller, which is
  *              always H5FD_open().
  *
  *     Failure: NULL
@@ -1010,26 +1015,21 @@ done:
  *
  *-------------------------------------------------------------------------
  */
+#ifdef H5_HAVE_LIBHDFS
 static H5FD_t *
 H5FD_hdfs_open(
-        const char *path, 
-        unsigned    flags, 
-        hid_t       fapl_id, 
+        const char *path,
+        unsigned    flags,
+        hid_t       fapl_id,
         haddr_t     maxaddr)
 {
     H5FD_t           *ret_value = NULL;
-#ifdef H5_HAVE_LIBHDFS
     H5FD_hdfs_t      *file      = NULL;
     hdfs_t           *handle    = NULL;
     H5FD_hdfs_fapl_t  fa;
-#endif
 
     FUNC_ENTER_NOAPI_NOINIT
 
-#ifndef H5_HAVE_LIBHDFS
-    HGOTO_ERROR(H5E_VFL, H5E_UNSUPPORTED, NULL,
-                "Illegal open of unsupported virtual file (hdfs)");
-#else
 #if HDFS_DEBUG
     HDfprintf(stdout, "H5FD_hdfs_open() called.\n");
 #endif /* HDFS_DEBUG */
@@ -1078,11 +1078,11 @@ H5FD_hdfs_open(
 
     HDassert(handle->magic == HDFS_HDFST_MAGIC);
 
-    /* create new file struct 
+    /* create new file struct
      */
     file = H5FL_CALLOC(H5FD_hdfs_t);
     if (file == NULL) {
-        HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, 
+        HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL,
                     "unable to allocate file struct")
     }
     file->hdfs_handle = handle;
@@ -1090,33 +1090,53 @@ H5FD_hdfs_open(
 
 #if HDFS_STATS
     if (FAIL == hdfs_reset_stats(file)) {
-        HGOTO_ERROR(H5E_INTERNAL, H5E_UNINITIALIZED, NULL, 
+        HGOTO_ERROR(H5E_INTERNAL, H5E_UNINITIALIZED, NULL,
                     "unable to reset file statistics")
     }
 #endif /* HDFS_STATS */
 
     ret_value = (H5FD_t*)file;
-#endif /* H5_HAVE_LIBHDFS */
 
 done:
-#ifdef H5_HAVE_LIBHDFS
     if (ret_value == NULL) {
-        if (handle != NULL) { 
+        if (handle != NULL) {
             if (FAIL == H5FD_hdfs_handle_close(handle)) {
-                HDONE_ERROR(H5E_VFL, H5E_CANTCLOSEFILE, NULL, 
+                HDONE_ERROR(H5E_VFL, H5E_CANTCLOSEFILE, NULL,
                             "unable to close HDFS file handle")
             }
         }
         if (file != NULL) {
             file = H5FL_FREE(H5FD_hdfs_t, file);
         }
-    } /* if null return value (error) */
-#endif /* H5_HAVE_LIBHDFS */
+    } /* end if null return value (error) */
+
+    FUNC_LEAVE_NOAPI(ret_value)
+
+} /* H5FD_hdfs_open() */
+
+#else /* H5_HAVE_LIBHDFS not defined */
+
+static H5FD_t *
+H5FD_hdfs_open(
+        const char H5_ATTR_UNUSED *path,
+        unsigned   H5_ATTR_UNUSED  flags,
+        hid_t      H5_ATTR_UNUSED  fapl_id,
+        haddr_t    H5_ATTR_UNUSED  maxaddr)
+{
+    H5FD_t           *ret_value = NULL;
+
+    FUNC_ENTER_NOAPI_NOINIT
+
+    HGOTO_ERROR(H5E_VFL, H5E_UNSUPPORTED, NULL,
+                "Illegal open of unsupported virtual file (hdfs)");
 
+done:
     FUNC_LEAVE_NOAPI(ret_value)
 
 } /* H5FD_hdfs_open() */
 
+#endif /* H5_HAVE_LIBHDFS */
+
 #if HDFS_STATS
 
 /*----------------------------------------------------------------------------
@@ -1124,7 +1144,7 @@ done:
  * Function: hdfs_fprint_stats()
  *
  * Purpose:
- * 
+ *
  *     Tabulate and pretty-print statistics for this virtual file.
  *
  *     Should be called upon file close.
@@ -1145,17 +1165,17 @@ done:
  *         - max (largest size read)
  *     2. tabulation of "bins", sepraring reads into exponentially-larger
  *        ranges of size.
- *         - columns for number of reads, total bytes, and average size, with 
+ *         - columns for number of reads, total bytes, and average size, with
  *           separate sub-colums for raw- and metadata reads.
  *         - each row represents one bin, identified by the top of its range
- *     
+ *
  *     Bin ranges can be modified with pound-defines at the top of this file.
  *
  *     Bins without any reads in their bounds are not printed.
  *
  *     An "overflow" bin is also present, to catch "big" reads.
  *
- *     Output for all bins (and range ceiling and average size report) 
+ *     Output for all bins (and range ceiling and average size report)
  *     is divied by powers of 1024. By corollary, four digits before the decimal
  *     is valid.
  *
@@ -1216,36 +1236,6 @@ hdfs_fprint_stats(
                     "hdfs handle has invalid magic")
     }
 
-    /* TODO: See what libhdfs exposes to us. */
-
-#if 0
-    if (file->s3r_handle->purl == NULL) {
-        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL,
-                    "parsed url structure cannot be null")
-    }
-    purl = file->s3r_handle->purl;
-
-    /******************
-     * PRINT FILENAME *
-     ******************/
-
-    HDfprintf(stream, "stats for %s://%s", purl->scheme, purl->host);
-    if (purl->port != NULL && purl->port[0] != '\0') {
-        HDfprintf(stream, ":%s", purl->port);
-    }
-    if (purl->query != NULL && purl->query[0] != '\0') {
-        if (purl->path != NULL && purl->path[0] != '\0') {
-            HDfprintf(stream, "/%s", purl->path);
-        } else {
-            HDfprintf(stream, "/");
-        }
-        HDfprintf(stream, "?%s", purl->query);
-    } else if (purl->path != NULL && purl->path[0] != '\0') {
-        HDfprintf(stream, "/%s", purl->path);
-    }
-    HDfprintf(stream, "\n");
-#endif
-
     /*******************
      * AGGREGATE STATS *
      *******************/
@@ -1254,18 +1244,22 @@ hdfs_fprint_stats(
         const hdfs_statsbin *r = &file->raw[i];
         const hdfs_statsbin *m = &file->meta[i];
 
-        if (m->min < min_meta)  min_meta = m->min;
-        if (r->min < min_raw)   min_raw  = r->min;
-        if (m->max > max_meta)  max_meta = m->max;
-        if (r->max > max_raw)   max_raw  = r->max;
+        if (m->min < min_meta)  { min_meta = m->min; }
+        if (r->min < min_raw)   { min_raw  = r->min; }
+        if (m->max > max_meta)  { max_meta = m->max; }
+        if (r->max > max_raw)   { max_raw  = r->max; }
 
         count_raw  += r->count;
         count_meta += m->count;
         bytes_raw  += r->bytes;
         bytes_meta += m->bytes;
     }
-    if (count_raw  > 0) average_raw  = (double)bytes_raw / (double)count_raw;
-    if (count_meta > 0) average_meta = (double)bytes_meta / (double)count_meta;
+    if (count_raw  > 0) {
+        average_raw  = (double)bytes_raw / (double)count_raw;
+    }
+    if (count_meta > 0) {
+        average_meta = (double)bytes_meta / (double)count_meta;
+    }
 
     /******************
      * PRINT OVERVIEW *
@@ -1342,9 +1336,9 @@ hdfs_fprint_stats(
      * PRINT INDIVIDUAL BIN STATS *
      ******************************/
 
-    HDfprintf(stream, 
+    HDfprintf(stream,
         "BINS             # of reads      total bytes         average size\n");
-    HDfprintf(stream, 
+    HDfprintf(stream,
         "    up-to      meta     raw     meta      raw       meta      raw\n");
 
     for (i = 0; i <= HDFS_STATS_BIN_COUNT; i++) {
@@ -1414,7 +1408,7 @@ hdfs_fprint_stats(
         HDassert(suffix_i < sizeof(suffixes));
 
         HDfprintf(
-                stream, 
+                stream,
                 " %8.3f%c %7d %7d %8.3f%c %8.3f%c %8.3f%c %8.3f%c\n",
                 re_dub, suffixes[suffix_i], /* bin ceiling      */
                 m->count,                   /* metadata reads   */
@@ -1428,7 +1422,6 @@ hdfs_fprint_stats(
 
 done:
     FUNC_LEAVE_NOAPI(ret_value);
-    
 } /* hdfs_fprint_stats */
 #endif /* HDFS_STATS */
 
@@ -1442,7 +1435,7 @@ done:
  *     Close an HDF5 file.
  *
  * Return:
- * 
+ *
  *     SUCCEED/FAIL
  *
  * Programmer: Jacob Smith
@@ -1452,35 +1445,31 @@ done:
  *
  *-------------------------------------------------------------------------
  */
+#ifdef H5_HAVE_LIBHDFS
+
 static herr_t
 H5FD_hdfs_close(H5FD_t *_file)
 {
     herr_t       ret_value = SUCCEED;
-#ifdef H5_HAVE_LIBHDFS
     H5FD_hdfs_t *file      = (H5FD_hdfs_t *)_file;
-#endif
 
     FUNC_ENTER_NOAPI_NOINIT
 
-#ifndef H5_HAVE_LIBHDFS
-    HGOTO_ERROR(H5E_VFL, H5E_CANTCLOSEFILE, FAIL,
-                "Illegal close of unsupported Virtual File (hdfs)")
-#else
 #if HDFS_DEBUG
     HDfprintf(stdout, "H5FD_hdfs_close() called.\n");
 #endif
 
-    /* Sanity checks 
+    /* Sanity checks
      */
     HDassert(file != NULL);
     HDassert(file->hdfs_handle != NULL);
     HDassert(file->hdfs_handle->magic == HDFS_HDFST_MAGIC);
 
-    /* Close the underlying request handle 
+    /* Close the underlying request handle
      */
-    if (file->hdfs_handle != NULL) { 
+    if (file->hdfs_handle != NULL) {
         if (FAIL == H5FD_hdfs_handle_close(file->hdfs_handle)) {
-            HGOTO_ERROR(H5E_VFL, H5E_CANTCLOSEFILE, FAIL, 
+            HGOTO_ERROR(H5E_VFL, H5E_CANTCLOSEFILE, FAIL,
                         "unable to close HDFS file handle")
         }
     }
@@ -1488,21 +1477,37 @@ H5FD_hdfs_close(H5FD_t *_file)
 #if HDFS_STATS
     /* TODO: mechanism to re-target stats printout */
     if (FAIL == hdfs_fprint_stats(stdout, file)) {
-        HGOTO_ERROR(H5E_INTERNAL, H5E_ERROR, FAIL, 
+        HGOTO_ERROR(H5E_INTERNAL, H5E_ERROR, FAIL,
                     "problem while writing file statistics")
     }
 #endif /* HDFS_STATS */
 
-    /* Release the file info 
+    /* Release the file info
      */
     file = H5FL_FREE(H5FD_hdfs_t, file);
-#endif /* H5_HAVE_LIBHDFS */
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5FD_hdfs_close() */
+
+#else /* H5_HAVE_LIBHDFS not defined */
+
+static herr_t
+H5FD_hdfs_close(H5FD_t H5_ATTR_UNUSED *_file)
+{
+    herr_t       ret_value = SUCCEED;
 
+    FUNC_ENTER_NOAPI_NOINIT
+
+    HGOTO_ERROR(H5E_VFL, H5E_CANTCLOSEFILE, FAIL,
+                "Illegal close of unsupported Virtual File (hdfs)")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5FD_hdfs_close() */
 
+#endif /* H5_HAVE_LIBHDFS */
+
 
 /*-------------------------------------------------------------------------
  *
@@ -1527,21 +1532,21 @@ done:
  *
  *-------------------------------------------------------------------------
  */
+#ifdef H5_HAVE_LIBHDFS
+
 static int
-H5FD_hdfs_cmp(const H5FD_t *_f1,
-              const H5FD_t *_f2)
+H5FD_hdfs_cmp(
+        const H5FD_t *_f1,
+        const H5FD_t *_f2)
 {
     int                ret_value = 0;
-#ifdef H5_HAVE_LIBHDFS
     const H5FD_hdfs_t *f1        = (const H5FD_hdfs_t *)_f1;
     const H5FD_hdfs_t *f2        = (const H5FD_hdfs_t *)_f2;
     hdfsFileInfo      *finfo1    = NULL;
     hdfsFileInfo      *finfo2    = NULL;
-#endif /* H5_HAVE_LIBHDFS */
 
     FUNC_ENTER_NOAPI_NOINIT_NOERR
 
-#ifdef H5_HAVE_LIBHDFS
 #if HDFS_DEBUG
     HDfprintf(stdout, "H5FD_hdfs_cmp() called.\n");
 #endif /* HDFS_DEBUG */
@@ -1556,23 +1561,37 @@ H5FD_hdfs_cmp(const H5FD_t *_f1,
     HDassert(finfo1 != NULL);
     HDassert(finfo2 != NULL);
 
-    if (finfo1->mKind        != finfo2->mKind)        HGOTO_DONE(-1);
-    if (finfo1->mName        != finfo2->mName)        HGOTO_DONE(-1);
-    if (finfo1->mLastMod     != finfo2->mLastMod)     HGOTO_DONE(-1);
-    if (finfo1->mSize        != finfo2->mSize)        HGOTO_DONE(-1);
-    if (finfo1->mReplication != finfo2->mReplication) HGOTO_DONE(-1);
-    if (finfo1->mBlockSize   != finfo2->mBlockSize)   HGOTO_DONE(-1);
-    if (strcmp(finfo1->mOwner, finfo2->mOwner))       HGOTO_DONE(-1);
-    if (strcmp(finfo1->mGroup, finfo2->mGroup))       HGOTO_DONE(-1);
-    if (finfo1->mPermissions != finfo2->mPermissions) HGOTO_DONE(-1);
-    if (finfo1->mLastAccess  != finfo2->mLastAccess)  HGOTO_DONE(-1);
-#endif /* H5_HAVE_LIBHDFS */
+    if (finfo1->mKind        != finfo2->mKind)        { HGOTO_DONE(-1); }
+    if (finfo1->mName        != finfo2->mName)        { HGOTO_DONE(-1); }
+    if (finfo1->mLastMod     != finfo2->mLastMod)     { HGOTO_DONE(-1); }
+    if (finfo1->mSize        != finfo2->mSize)        { HGOTO_DONE(-1); }
+    if (finfo1->mReplication != finfo2->mReplication) { HGOTO_DONE(-1); }
+    if (finfo1->mBlockSize   != finfo2->mBlockSize)   { HGOTO_DONE(-1); }
+    if (strcmp(finfo1->mOwner, finfo2->mOwner))       { HGOTO_DONE(-1); }
+    if (strcmp(finfo1->mGroup, finfo2->mGroup))       { HGOTO_DONE(-1); }
+    if (finfo1->mPermissions != finfo2->mPermissions) { HGOTO_DONE(-1); }
+    if (finfo1->mLastAccess  != finfo2->mLastAccess)  { HGOTO_DONE(-1); }
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
+} /* H5FD_hdfs_cmp() */
+
+#else /* H5_HAVE_LIBHDFS not defined */
+
+static int
+H5FD_hdfs_cmp(
+        const H5FD_t H5_ATTR_UNUSED *_f1,
+        const H5FD_t H5_ATTR_UNUSED *_f2)
+{
+    int                ret_value = 0;
 
+    FUNC_ENTER_NOAPI_NOINIT_NOERR
+
+    FUNC_LEAVE_NOAPI(ret_value)
 } /* H5FD_hdfs_cmp() */
 
+#endif /* H5_HAVE_LIBHDFS */
+
 
 /*-------------------------------------------------------------------------
  * Function:    H5FD_hdfs_query
@@ -1580,7 +1599,7 @@ done:
  * Purpose:     Set the flags that this VFL driver is capable of supporting.
  *              (listed in H5FDpublic.h)
  *
- *              Note that since the HDFS VFD is read only, most flags 
+ *              Note that since the HDFS VFD is read only, most flags
  *              are irrelevant.
  *
  *              The term "set" is highly misleading...
@@ -1595,7 +1614,7 @@ done:
  */
 static herr_t
 H5FD_hdfs_query(
-        const H5FD_t  H5_ATTR_UNUSED *_file, 
+        const H5FD_t  H5_ATTR_UNUSED *_file,
         unsigned long                *flags) /* out variable */
 {
     FUNC_ENTER_NOAPI_NOINIT_NOERR
@@ -1606,11 +1625,10 @@ H5FD_hdfs_query(
 
     if (flags) {
         *flags = 0;
-        *flags |= H5FD_FEAT_DATA_SIEVE; 
+        *flags |= H5FD_FEAT_DATA_SIEVE;
     }
 
     FUNC_LEAVE_NOAPI(SUCCEED)
-
 } /* H5FD_hdfs_query() */
 
 
@@ -1635,14 +1653,14 @@ H5FD_hdfs_query(
  *
  *-------------------------------------------------------------------------
  */
+#ifdef H5_HAVE_LIBHDFS
+
 static haddr_t
 H5FD_hdfs_get_eoa(
-        const H5FD_t                *_file, 
+        const H5FD_t                *_file,
         H5FD_mem_t   H5_ATTR_UNUSED  type)
 {
-#ifdef H5_HAVE_LIBHDFS
     const H5FD_hdfs_t *file = (const H5FD_hdfs_t *)_file;
-#endif /* H5_HAVE_LIBHDFS */
 
     FUNC_ENTER_NOAPI_NOINIT_NOERR
 
@@ -1650,14 +1668,27 @@ H5FD_hdfs_get_eoa(
     HDfprintf(stdout, "H5FD_hdfs_get_eoa() called.\n");
 #endif
 
-#ifdef H5_HAVE_LIBHDFS
     FUNC_LEAVE_NOAPI(file->eoa)
-#else
-    FUNC_LEAVE_NOAPI(0)
-#endif /* H5_HAVE_LIBHDFS */
+} /* end H5FD_hdfs_get_eoa() */
+
+#else /* H5_HAVE_LIBHDFS not defined */
+
+static haddr_t
+H5FD_hdfs_get_eoa(
+        const H5FD_t H5_ATTR_UNUSED *_file,
+        H5FD_mem_t   H5_ATTR_UNUSED  type)
+{
+    FUNC_ENTER_NOAPI_NOINIT_NOERR
 
+#if HDFS_DEBUG
+    HDfprintf(stdout, "H5FD_hdfs_get_eoa() called.\n");
+#endif
+
+    FUNC_LEAVE_NOAPI(0)
 } /* end H5FD_hdfs_get_eoa() */
 
+#endif /* H5_HAVE_LIBHDFS */
+
 
 /*-------------------------------------------------------------------------
  *
@@ -1678,15 +1709,15 @@ H5FD_hdfs_get_eoa(
  *
  *-------------------------------------------------------------------------
  */
+#ifdef H5_HAVE_LIBHDFS
+
 static herr_t
 H5FD_hdfs_set_eoa(
-        H5FD_t                    *_file, 
-        H5FD_mem_t H5_ATTR_UNUSED  type, 
+        H5FD_t                    *_file,
+        H5FD_mem_t H5_ATTR_UNUSED  type,
         haddr_t                    addr)
 {
-#ifdef H5_HAVE_LIBHDFS
     H5FD_hdfs_t *file = (H5FD_hdfs_t *)_file;
-#endif /* H5_HAVE_LIBHDFS */
 
     FUNC_ENTER_NOAPI_NOINIT_NOERR
 
@@ -1694,16 +1725,30 @@ H5FD_hdfs_set_eoa(
     HDfprintf(stdout, "H5FD_hdfs_set_eoa() called.\n");
 #endif
 
-#ifdef H5_HAVE_LIBHDFS
     file->eoa = addr;
 
     FUNC_LEAVE_NOAPI(SUCCEED)
-#else
-    FUNC_LEAVE_NOAPI(FAIL)
-#endif /* H5_HAVE_LIBHDFS */
+} /* H5FD_hdfs_set_eoa() */
+
+#else /* H5_HAVE_LIBHDFS not defined */
+
+static herr_t
+H5FD_hdfs_set_eoa(
+        H5FD_t     H5_ATTR_UNUSED *_file,
+        H5FD_mem_t H5_ATTR_UNUSED  type,
+        haddr_t    H5_ATTR_UNUSED  addr)
+{
+    FUNC_ENTER_NOAPI_NOINIT_NOERR
 
+#if HDFS_DEBUG
+    HDfprintf(stdout, "H5FD_hdfs_set_eoa() called.\n");
+#endif
+
+    FUNC_LEAVE_NOAPI(FAIL)
 } /* H5FD_hdfs_set_eoa() */
 
+#endif /* H5_HAVE_LIBHDFS */
+
 
 /*-------------------------------------------------------------------------
  *
@@ -1715,7 +1760,7 @@ H5FD_hdfs_set_eoa(
  *
  * Return:
  *
- *     EOF: the first address past the end of the "file", either the 
+ *     EOF: the first address past the end of the "file", either the
  *     filesystem file or the HDF5 file.
  *
  * Programmer: Jacob Smith
@@ -1723,14 +1768,14 @@ H5FD_hdfs_set_eoa(
  *
  *-------------------------------------------------------------------------
  */
+#ifdef H5_HAVE_LIBHDFS
+
 static haddr_t
 H5FD_hdfs_get_eof(
-        const H5FD_t                *_file, 
+        const H5FD_t                *_file,
         H5FD_mem_t   H5_ATTR_UNUSED  type)
 {
-#ifdef H5_HAVE_LIBHDFS
     const H5FD_hdfs_t *file = (const H5FD_hdfs_t *)_file;
-#endif /* H5_HAVE_LIBHDFS */
 
     FUNC_ENTER_NOAPI_NOINIT_NOERR
 
@@ -1738,17 +1783,30 @@ H5FD_hdfs_get_eof(
     HDfprintf(stdout, "H5FD_hdfs_get_eof() called.\n");
 #endif
 
-#ifdef H5_HAVE_LIBHDFS
     HDassert(file->hdfs_handle != NULL);
     HDassert(file->hdfs_handle->magic == HDFS_HDFST_MAGIC);
 
     FUNC_LEAVE_NOAPI((size_t) file->hdfs_handle->fileinfo->mSize)
-#else
-    FUNC_LEAVE_NOAPI((size_t)0)
-#endif /* H5_HAVE_LIBHDFS */
+} /* end H5FD_hdfs_get_eof() */
+
+#else /* H5_HAVE_LIBHDFS not defined */
+
+static haddr_t
+H5FD_hdfs_get_eof(
+        const H5FD_t H5_ATTR_UNUSED *_file,
+        H5FD_mem_t   H5_ATTR_UNUSED  type)
+{
+    FUNC_ENTER_NOAPI_NOINIT_NOERR
 
+#if HDFS_DEBUG
+    HDfprintf(stdout, "H5FD_hdfs_get_eof() called.\n");
+#endif
+
+    FUNC_LEAVE_NOAPI((size_t)0)
 } /* end H5FD_hdfs_get_eof() */
 
+#endif /* H5_HAVE_LIBHDFS */
+
 
 /*-------------------------------------------------------------------------
  *
@@ -1769,16 +1827,16 @@ H5FD_hdfs_get_eof(
  *
  *-------------------------------------------------------------------------
  */
+#ifdef H5_HAVE_LIBHDFS
+
 static herr_t
 H5FD_hdfs_get_handle(
-        H5FD_t                 *_file, 
-        hid_t  H5_ATTR_UNUSED   fapl, 
+        H5FD_t                 *_file,
+        hid_t  H5_ATTR_UNUSED   fapl,
         void                  **file_handle)
 {
     herr_t       ret_value = SUCCEED;
-#ifdef H5_HAVE_LIBHDFS
     H5FD_hdfs_t *file      = (H5FD_hdfs_t *)_file;
-#endif
 
     FUNC_ENTER_NOAPI_NOINIT
 
@@ -1786,29 +1844,48 @@ H5FD_hdfs_get_handle(
     HDfprintf(stdout, "H5FD_hdfs_get_handle() called.\n");
 #endif /* HDFS_DEBUG */
 
-#ifdef H5_HAVE_LIBHDFS
     if (!file_handle) {
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL,
                     "file handle not valid")
     }
 
     *file_handle = file->hdfs_handle;
-#else
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5FD_hdfs_get_handle() */
+
+#else /* H5_HAVE_LIBHDFS not defined */
+
+static herr_t
+H5FD_hdfs_get_handle(
+        H5FD_t H5_ATTR_UNUSED  *_file,
+        hid_t  H5_ATTR_UNUSED   fapl,
+        void   H5_ATTR_UNUSED **file_handle)
+{
+    herr_t       ret_value = SUCCEED;
+
+    FUNC_ENTER_NOAPI_NOINIT
+
+#if HDFS_DEBUG
+    HDfprintf(stdout, "H5FD_hdfs_get_handle() called.\n");
+#endif /* HDFS_DEBUG */
+
     HGOTO_ERROR(H5E_VFL, H5E_UNSUPPORTED, FAIL,
                 "Illegal get-handle of unsupported virtual file (hdfs)");
-#endif /* H5_HAVE_LIBHDFS */
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
-
 } /* end H5FD_hdfs_get_handle() */
 
+#endif /* H5_HAVE_LIBHDFS */
+
 
 /*-------------------------------------------------------------------------
  *
  * Function: H5FD_hdfs_read()
  *
- * Purpose: 
+ * Purpose:
  *
  *     Reads SIZE bytes of data from FILE beginning at address ADDR
  *     into buffer BUF according to data transfer properties in DXPL_ID.
@@ -1828,20 +1905,20 @@ done:
  *
  *-------------------------------------------------------------------------
  */
+#ifdef H5_HAVE_LIBHDFS
+
 static herr_t
 H5FD_hdfs_read(
-        H5FD_t                    *_file, 
-        H5FD_mem_t H5_ATTR_UNUSED  type, 
+        H5FD_t                    *_file,
+        H5FD_mem_t H5_ATTR_UNUSED  type,
         hid_t      H5_ATTR_UNUSED  dxpl_id,
         haddr_t                    addr, /* start offset   */
         size_t                     size, /* length of read */
         void                      *buf)  /* out            */
 {
     herr_t       ret_value = SUCCEED;
-#if H5_HAVE_LIBHDFS
     H5FD_hdfs_t *file      = (H5FD_hdfs_t *)_file;
     size_t       filesize  = 0;
-#endif /* H5_HAVE_LIBHDFS */
 #if HDFS_STATS
     /* working variables for storing stats */
     hdfs_statsbin *bin   = NULL;
@@ -1854,10 +1931,6 @@ H5FD_hdfs_read(
     HDfprintf(stdout, "H5FD_hdfs_read() called.\n");
 #endif /* HDFS_DEBUG */
 
-#ifndef H5_HAVE_LIBHDFS
-    HGOTO_ERROR(H5E_VFL, H5E_UNSUPPORTED, FAIL,
-                "Illegal get-handle of unsupported virtual file (hdfs)");
-#else
     HDassert(file != NULL);
     HDassert(file->hdfs_handle != NULL);
     HDassert(file->hdfs_handle->magic == HDFS_HDFST_MAGIC);
@@ -1894,37 +1967,64 @@ H5FD_hdfs_read(
         ? &file->raw[bin_i]
         : &file->meta[bin_i];
 
-    /* Store collected stats in appropriate bin 
+    /* Store collected stats in appropriate bin
      */
     if (bin->count == 0) {
         bin->min = size;
         bin->max = size;
-    } else {
-        if (size < bin->min) bin->min = size;
-        if (size > bin->max) bin->max = size;
+    }
+    else {
+        if (size < bin->min) { bin->min = size; }
+        if (size > bin->max) { bin->max = size; }
     }
     bin->count++;
     bin->bytes += (unsigned long long)size;
 
 #endif /* HDFS_STATS */
-#endif /* H5_HAVE_LIBHDFS */
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5FD_hdfs_read() */
+
+#else /* H5_HAVE_LIBHDFS not defined */
+
+static herr_t
+H5FD_hdfs_read(
+        H5FD_t     H5_ATTR_UNUSED *_file,
+        H5FD_mem_t H5_ATTR_UNUSED  type,
+        hid_t      H5_ATTR_UNUSED  dxpl_id,
+        haddr_t    H5_ATTR_UNUSED  addr,
+        size_t     H5_ATTR_UNUSED  size,
+        void       H5_ATTR_UNUSED *buf)
+{
+    herr_t       ret_value = SUCCEED;
+
+    FUNC_ENTER_NOAPI_NOINIT
+
+#if HDFS_DEBUG
+    HDfprintf(stdout, "H5FD_hdfs_read() called.\n");
+#endif /* HDFS_DEBUG */
+
+    HGOTO_ERROR(H5E_VFL, H5E_UNSUPPORTED, FAIL,
+                "Illegal get-handle of unsupported virtual file (hdfs)");
 
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5FD_hdfs_read() */
 
+#endif /* H5_HAVE_LIBHDFS */
+
 
 /*-------------------------------------------------------------------------
  *
  * Function: H5FD_hdfs_write()
  *
- * Purpose: 
+ * Purpose:
  *
  *     Write bytes to file.
  *     UNSUPPORTED IN READ-ONLY HDFS VFD.
  *
- * Return: 
+ * Return:
  *
  *     FAIL (Not possible with Read-Only S3 file.)
  *
@@ -1937,11 +2037,11 @@ done:
  */
 static herr_t
 H5FD_hdfs_write(
-        H5FD_t     H5_ATTR_UNUSED *_file, 
-        H5FD_mem_t H5_ATTR_UNUSED  type, 
+        H5FD_t     H5_ATTR_UNUSED *_file,
+        H5FD_mem_t H5_ATTR_UNUSED  type,
         hid_t      H5_ATTR_UNUSED  dxpl_id,
-        haddr_t    H5_ATTR_UNUSED  addr, 
-        size_t     H5_ATTR_UNUSED  size, 
+        haddr_t    H5_ATTR_UNUSED  addr,
+        size_t     H5_ATTR_UNUSED  size,
         const void H5_ATTR_UNUSED *buf)
 {
     herr_t ret_value = FAIL;
@@ -1957,7 +2057,6 @@ H5FD_hdfs_write(
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
-
 } /* H5FD_hdfs_write() */
 
 
@@ -1985,8 +2084,8 @@ done:
  */
 static herr_t
 H5FD_hdfs_truncate(
-        H5FD_t  H5_ATTR_UNUSED *_file, 
-        hid_t   H5_ATTR_UNUSED  dxpl_id, 
+        H5FD_t  H5_ATTR_UNUSED *_file,
+        hid_t   H5_ATTR_UNUSED  dxpl_id,
         hbool_t H5_ATTR_UNUSED  closing)
 {
     herr_t ret_value = SUCCEED;
@@ -2002,7 +2101,6 @@ H5FD_hdfs_truncate(
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
-
 } /* end H5FD_hdfs_truncate() */
 
 
@@ -2031,12 +2129,11 @@ done:
  */
 static herr_t
 H5FD_hdfs_lock(
-        H5FD_t  H5_ATTR_UNUSED *_file, 
+        H5FD_t  H5_ATTR_UNUSED *_file,
         hbool_t H5_ATTR_UNUSED  rw)
 {
     FUNC_ENTER_NOAPI_NOINIT_NOERR
     FUNC_LEAVE_NOAPI(SUCCEED)
-
 } /* end H5FD_hdfs_lock() */
 
 
@@ -2065,6 +2162,5 @@ H5FD_hdfs_unlock(H5FD_t H5_ATTR_UNUSED *_file)
 {
     FUNC_ENTER_NOAPI_NOINIT_NOERR
     FUNC_LEAVE_NOAPI(SUCCEED)
-
 } /* end H5FD_hdfs_unlock() */
 
diff --git a/src/H5FDmpi.c b/src/H5FDmpi.c
index 7d58b7a..b2959a5 100644
--- a/src/H5FDmpi.c
+++ b/src/H5FDmpi.c
@@ -267,115 +267,6 @@ H5FD_mpi_haddr_to_MPIOff(haddr_t addr, MPI_Offset *mpi_off/*out*/)
     FUNC_LEAVE_NOAPI(ret_value)
 }
 
-
-/*-------------------------------------------------------------------------
- * Function:    H5FD_mpi_comm_info_dup
- *
- * Purpose:     Make duplicates of communicator and Info object.
- * 		If the Info object is in fact MPI_INFO_NULL, no duplicate
- * 		is made but the same value assigned to the new Info object
- * 		handle.
- *
- * Return:      Success:	Non-negative.  The new communicator and Info
- * 				object handles are returned via comm_new and
- * 				info_new pointers.
- *
- * 		Failure:	Negative.
- *
- * Programmer:  Albert Cheng
- *              Jan  8, 2003
- *
- * Modifications:
- *-------------------------------------------------------------------------
- */
-herr_t
-H5FD_mpi_comm_info_dup(MPI_Comm comm, MPI_Info info, MPI_Comm *comm_new, MPI_Info *info_new)
-{
-    herr_t	ret_value=SUCCEED;
-    MPI_Comm	comm_dup=MPI_COMM_NULL;
-    MPI_Info	info_dup=MPI_INFO_NULL;
-    int		mpi_code;
-
-    FUNC_ENTER_NOAPI(FAIL)
-
-    /* Check arguments */
-    if (MPI_COMM_NULL == comm)
-	HGOTO_ERROR(H5E_INTERNAL, H5E_BADVALUE, FAIL, "not a valid argument")
-    if (!comm_new || !info_new)
-	HGOTO_ERROR(H5E_INTERNAL, H5E_BADVALUE, FAIL, "bad pointers")
-
-    /* Dup them.  Using temporary variables for error recovery cleanup. */
-    if (MPI_SUCCESS != (mpi_code=MPI_Comm_dup(comm, &comm_dup)))
-	HMPI_GOTO_ERROR(FAIL, "MPI_Comm_dup failed", mpi_code)
-    if (MPI_INFO_NULL != info){
-	if (MPI_SUCCESS != (mpi_code=MPI_Info_dup(info, &info_dup)))
-	    HMPI_GOTO_ERROR(FAIL, "MPI_Info_dup failed", mpi_code)
-    }else{
-	/* No dup, just copy it. */
-	info_dup = info;
-    }
-
-    /* Set MPI_ERRORS_RETURN on comm_dup so that MPI failures are not fatal, 
-       and return codes can be checked and handled. May 23, 2017 FTW */
-    if (MPI_SUCCESS != (mpi_code = MPI_Comm_set_errhandler(comm_dup, MPI_ERRORS_RETURN)))
-        HMPI_GOTO_ERROR(FAIL, "MPI_Errhandler_set failed", mpi_code)
- 
-    /* copy them to the return arguments */
-    *comm_new = comm_dup;
-    *info_new = info_dup;
-
-done:
-    if (FAIL == ret_value){
-	/* need to free anything created here */
-	if (MPI_COMM_NULL != comm_dup)
-	    MPI_Comm_free(&comm_dup);
-	if (MPI_INFO_NULL != info_dup)
-	    MPI_Info_free(&info_dup);
-    }
-
-    FUNC_LEAVE_NOAPI(ret_value)
-}
-
-
-/*-------------------------------------------------------------------------
- * Function:    H5FD_mpi_comm_info_free
- *
- * Purpose:     Free the communicator and Info object.
- * 		If comm or info is in fact MPI_COMM_NULL or MPI_INFO_NULL
- * 		respectively, no action occurs to it.
- *
- * Return:      Success:	Non-negative.  The values the pointers refer
- * 				to will be set to the corresponding NULL
- * 				handles.
- *
- * 		Failure:	Negative.
- *
- * Programmer:  Albert Cheng
- *              Jan  8, 2003
- *
- * Modifications:
- *-------------------------------------------------------------------------
- */
-herr_t
-H5FD_mpi_comm_info_free(MPI_Comm *comm, MPI_Info *info)
-{
-    herr_t      ret_value=SUCCEED;
-
-    FUNC_ENTER_NOAPI(FAIL)
-
-    /* Check arguments */
-    if (!comm || !info)
-	HGOTO_ERROR(H5E_INTERNAL, H5E_BADVALUE, FAIL, "not a valid argument")
-
-    if (MPI_COMM_NULL != *comm)
-	MPI_Comm_free(comm);
-    if (MPI_INFO_NULL != *info)
-	MPI_Info_free(info);
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-}
-
 #ifdef NOT_YET
 
 /*-------------------------------------------------------------------------
diff --git a/src/H5FDmpio.c b/src/H5FDmpio.c
index d5aa170..6ca7aa4 100644
--- a/src/H5FDmpio.c
+++ b/src/H5FDmpio.c
@@ -167,7 +167,7 @@ USAGE
     herr_t H5FD__init_package()
 
 RETURNS
-    Non-negative on success/Negative on failure
+    SUCCEED/FAIL
 
 DESCRIPTION
     Initializes any interface-specific data or routines.  (Just calls
@@ -249,9 +249,9 @@ done:
 
 
 /*---------------------------------------------------------------------------
- * Function:	H5FD__mpio_term
+ * Function:    H5FD__mpio_term
  *
- * Purpose:	Shut down the VFD
+ * Purpose:     Shut down the VFD
  *
  * Returns:     Non-negative on success or negative on failure
  *
@@ -263,7 +263,7 @@ done:
 static herr_t
 H5FD__mpio_term(void)
 {
-    FUNC_ENTER_STATIC
+    FUNC_ENTER_STATIC_NOERR
 
     /* Reset VFL ID */
     H5FD_MPIO_g = 0;
@@ -273,40 +273,40 @@ H5FD__mpio_term(void)
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5Pset_fapl_mpio
+ * Function:    H5Pset_fapl_mpio
  *
- * Purpose:	Store the user supplied MPIO communicator comm and info in
- *		the file access property list FAPL_ID which can then be used
- *		to create and/or open the file.  This function is available
- *		only in the parallel HDF5 library and is not collective.
+ * Purpose:     Store the user supplied MPIO communicator comm and info in
+ *              the file access property list FAPL_ID which can then be used
+ *              to create and/or open the file.  This function is available
+ *              only in the parallel HDF5 library and is not collective.
  *
- *		comm is the MPI communicator to be used for file open as
- *		defined in MPI_FILE_OPEN of MPI-2. This function makes a
- *		duplicate of comm. Any modification to comm after this function
- *		call returns has no effect on the access property list.
+ *              comm is the MPI communicator to be used for file open as
+ *              defined in MPI_FILE_OPEN of MPI-2. This function makes a
+ *              duplicate of comm. Any modification to comm after this function
+ *              call returns has no effect on the access property list.
  *
- *		info is the MPI Info object to be used for file open as
- *		defined in MPI_FILE_OPEN of MPI-2. This function makes a
- *		duplicate of info. Any modification to info after this
- *		function call returns has no effect on the access property
- *		list.
+ *              info is the MPI Info object to be used for file open as
+ *              defined in MPI_FILE_OPEN of MPI-2. This function makes a
+ *              duplicate of info. Any modification to info after this
+ *              function call returns has no effect on the access property
+ *              list.
  *
  *              If fapl_id has previously set comm and info values, they
  *              will be replaced and the old communicator and Info object
  *              are freed.
  *
- * Return:	Success:	Non-negative
- * 		Failure:	Negative
+ * Return:      Success:    Non-negative
+ *              Failure:    Negative
  *
- * Programmer:	Albert Cheng
- *		Feb 3, 1998
+ * Programmer:  Albert Cheng
+ *              Feb 3, 1998
  *
  *-------------------------------------------------------------------------
  */
 herr_t
 H5Pset_fapl_mpio(hid_t fapl_id, MPI_Comm comm, MPI_Info info)
 {
-    H5FD_mpio_fapl_t	fa;
+    H5FD_mpio_fapl_t    fa;
     H5P_genplist_t *plist;      /* Property list pointer */
     herr_t ret_value;
 
@@ -319,7 +319,7 @@ H5Pset_fapl_mpio(hid_t fapl_id, MPI_Comm comm, MPI_Info info)
     if(NULL == (plist = H5P_object_verify(fapl_id, H5P_FILE_ACCESS)))
         HGOTO_ERROR(H5E_PLIST, H5E_BADTYPE, FAIL, "not a file access list")
     if(MPI_COMM_NULL == comm)
-	HGOTO_ERROR(H5E_PLIST, H5E_BADTYPE, FAIL, "not a valid communicator")
+        HGOTO_ERROR(H5E_PLIST, H5E_BADTYPE, FAIL, "not a valid communicator")
 
     /* Initialize driver specific properties */
     HDmemset(&fa, 0, sizeof(H5FD_mpio_fapl_t));
@@ -335,25 +335,25 @@ done:
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5Pget_fapl_mpio
- *
- * Purpose:	If the file access property list is set to the H5FD_MPIO
- *		driver then this function returns duplicates of the MPI
- *		communicator and Info object stored through the comm and
- *		info pointers.  It is the responsibility of the application
- *		to free the returned communicator and Info object.
- *
- * Return:	Success:	Non-negative with the communicator and
- *				Info object returned through the comm and
- *				info arguments if non-null. Since they are
- *				duplicates of the stored objects, future
- *				modifications to the access property list do
- *				not affect them and it is the responsibility
- *				of the application to free them.
- * 		Failure:	Negative
- *
- * Programmer:	Robb Matzke
- *		Thursday, February 26, 1998
+ * Function:    H5Pget_fapl_mpio
+ *
+ * Purpose:     If the file access property list is set to the H5FD_MPIO
+ *              driver then this function returns duplicates of the MPI
+ *              communicator and Info object stored through the comm and
+ *              info pointers.  It is the responsibility of the application
+ *              to free the returned communicator and Info object.
+ *
+ * Return:      Success:    Non-negative with the communicator and
+ *                          Info object returned through the comm and
+ *                          info arguments if non-null. Since they are
+ *                          duplicates of the stored objects, future
+ *                          modifications to the access property list do
+ *                          not affect them and it is the responsibility
+ *                          of the application to free them.
+ *              Failure:    Negative
+ *
+ * Programmer:  Robb Matzke
+ *              Thursday, February 26, 1998
  *
  *-------------------------------------------------------------------------
  */
@@ -362,9 +362,9 @@ H5Pget_fapl_mpio(hid_t fapl_id, MPI_Comm *comm/*out*/, MPI_Info *info/*out*/)
 {
     H5P_genplist_t *plist;      /* Property list pointer */
     const H5FD_mpio_fapl_t *fa;       /* MPIO fapl info */
-    MPI_Comm	comm_tmp = MPI_COMM_NULL;
+    MPI_Comm    comm_tmp = MPI_COMM_NULL;
     hbool_t     comm_copied = FALSE;    /* MPI Comm has been duplicated */
-    int		mpi_code;		/* MPI return code */
+    int         mpi_code;               /* MPI return code */
     herr_t      ret_value = SUCCEED;    /* Return value */
 
     FUNC_ENTER_API(FAIL)
@@ -381,19 +381,19 @@ H5Pget_fapl_mpio(hid_t fapl_id, MPI_Comm *comm/*out*/, MPI_Info *info/*out*/)
     /* Store the duplicated communicator in a temporary variable for error */
     /* recovery in case the INFO duplication fails. */
     if(comm) {
-	if(MPI_SUCCESS != (mpi_code = MPI_Comm_dup(fa->comm, &comm_tmp)))
-	    HMPI_GOTO_ERROR(FAIL, "MPI_Comm_dup failed", mpi_code)
+        if(MPI_SUCCESS != (mpi_code = MPI_Comm_dup(fa->comm, &comm_tmp)))
+            HMPI_GOTO_ERROR(FAIL, "MPI_Comm_dup failed", mpi_code)
         comm_copied = TRUE;
     } /* end if */
 
     if(info) {
-	if(MPI_INFO_NULL != fa->info) {
-	    if(MPI_SUCCESS != (mpi_code = MPI_Info_dup(fa->info, info)))
-		HMPI_GOTO_ERROR(FAIL, "MPI_Info_dup failed", mpi_code)
-	} /* end if */
+        if(MPI_INFO_NULL != fa->info) {
+            if(MPI_SUCCESS != (mpi_code = MPI_Info_dup(fa->info, info)))
+                HMPI_GOTO_ERROR(FAIL, "MPI_Info_dup failed", mpi_code)
+        } /* end if */
         else
-	    /* do not dup it */
-	    *info = MPI_INFO_NULL;
+            /* do not dup it */
+            *info = MPI_INFO_NULL;
     } /* end if */
 
     /* Store the copied communicator, now that the Info object has been
@@ -404,33 +404,33 @@ H5Pget_fapl_mpio(hid_t fapl_id, MPI_Comm *comm/*out*/, MPI_Info *info/*out*/)
 
 done:
     if(ret_value < 0)
-	/* need to free anything created here */
-	if(comm_copied)
-	    MPI_Comm_free(&comm_tmp);
+        /* need to free anything created here */
+        if(comm_copied)
+            MPI_Comm_free(&comm_tmp);
 
     FUNC_LEAVE_API(ret_value)
 } /* end H5Pget_fapl_mpio() */
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5Pset_dxpl_mpio
+ * Function:    H5Pset_dxpl_mpio
  *
- * Purpose:	Set the data transfer property list DXPL_ID to use transfer
- *		mode XFER_MODE. The property list can then be used to control
- *		the I/O transfer mode during data I/O operations. The valid
- *		transfer modes are:
+ * Purpose:     Set the data transfer property list DXPL_ID to use transfer
+ *              mode XFER_MODE. The property list can then be used to control
+ *              the I/O transfer mode during data I/O operations. The valid
+ *              transfer modes are:
  *
- * 		H5FD_MPIO_INDEPENDENT:
- *			Use independent I/O access (the default).
+ *              H5FD_MPIO_INDEPENDENT:
+ *                  Use independent I/O access (the default).
  *
- * 		H5FD_MPIO_COLLECTIVE:
- *			Use collective I/O access.
+ *              H5FD_MPIO_COLLECTIVE:
+ *                  Use collective I/O access.
  *
- * Return:	Success:	Non-negative
- * 		Failure:	Negative
+ * Return:      Success:    Non-negative
+ *              Failure:    Negative
  *
- * Programmer:	Albert Cheng
- *		April 2, 1998
+ * Programmer:  Albert Cheng
+ *              April 2, 1998
  *
  *-------------------------------------------------------------------------
  */
@@ -461,18 +461,18 @@ done:
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5Pget_dxpl_mpio
+ * Function:    H5Pget_dxpl_mpio
  *
- * Purpose:	Queries the transfer mode current set in the data transfer
- *		property list DXPL_ID. This is not collective.
+ * Purpose:     Queries the transfer mode current set in the data transfer
+ *              property list DXPL_ID. This is not collective.
  *
- * Return:	Success:	Non-negative, with the transfer mode returned
- *				through the XFER_MODE argument if it is
- *				non-null.
- * 		Failure:	Negative
+ * Return:      Success:    Non-negative, with the transfer mode returned
+ *                          through the XFER_MODE argument if it is
+ *                          non-null.
+ *              Failure:    Negative
  *
- * Programmer:	Albert Cheng
- *		April 2, 1998
+ * Programmer:  Albert Cheng
+ *              April 2, 1998
  *
  *-------------------------------------------------------------------------
  */
@@ -500,21 +500,20 @@ done:
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5Pset_dxpl_mpio_collective_opt
+ * Function:    H5Pset_dxpl_mpio_collective_opt
  *
- * Purpose:	To set a flag to choose linked chunk I/O or multi-chunk I/O
- *		without involving decision-making inside HDF5
+ * Purpose:     To set a flag to choose linked chunk I/O or multi-chunk I/O
+ *              without involving decision-making inside HDF5
  *
- * Note:	The library will do linked chunk I/O or multi-chunk I/O without
- *		involving communications for decision-making process.
- *		The library won't behave as it asks for only when we find
- *		that the low-level MPI-IO package doesn't support this.
+ * Note:        The library will do linked chunk I/O or multi-chunk I/O without
+ *              involving communications for decision-making process.
+ *              The library won't behave as it asks for only when we find
+ *              that the low-level MPI-IO package doesn't support this.
  *
- * Return:	Success:	Non-negative
- * 		Failure:	Negative
+ * Return:      Success:    Non-negative
+ *              Failure:    Negative
  *
- * Programmer:	Kent Yang
- *		? ?, ?
+ * Programmer:  Kent Yang
  *
  *-------------------------------------------------------------------------
  */
@@ -543,21 +542,20 @@ done:
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5Pset_dxpl_mpio_chunk_opt
+ * Function:    H5Pset_dxpl_mpio_chunk_opt
  *
- * Purpose:	To set a flag to choose linked chunk I/O or multi-chunk I/O
- *		without involving decision-making inside HDF5
+ * Purpose:     To set a flag to choose linked chunk I/O or multi-chunk I/O
+ *              without involving decision-making inside HDF5
  *
- * Note:	The library will do linked chunk I/O or multi-chunk I/O without
- *		involving communications for decision-making process.
- *		The library won't behave as it asks for only when we find
- *		that the low-level MPI-IO package doesn't support this.
+ * Note:        The library will do linked chunk I/O or multi-chunk I/O without
+ *              involving communications for decision-making process.
+ *              The library won't behave as it asks for only when we find
+ *              that the low-level MPI-IO package doesn't support this.
  *
- * Return:	Success:	Non-negative
- * 		Failure:	Negative
+ * Return:      Success:    Non-negative
+ *              Failure:    Negative
  *
- * Programmer:	Kent Yang
- *		? ?, ?
+ * Programmer:  Kent Yang
  *
  *-------------------------------------------------------------------------
  */
@@ -586,19 +584,18 @@ done:
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5Pset_dxpl_mpio_chunk_opt_num
+ * Function:    H5Pset_dxpl_mpio_chunk_opt_num
  *
- * Purpose:	To set a threshold for doing linked chunk IO
+ * Purpose:     To set a threshold for doing linked chunk IO
  *
- * Note:	If the number is greater than the threshold set by the user,
- *		the library will do linked chunk I/O; otherwise, I/O will be
- *		done for every chunk.
+ * Note:        If the number is greater than the threshold set by the user,
+ *              the library will do linked chunk I/O; otherwise, I/O will be
+ *              done for every chunk.
  *
- * Return:	Success:	Non-negative
- * 		Failure:	Negative
+ * Return:      Success:    Non-negative
+ *              Failure:    Negative
  *
- * Programmer:	Kent Yang
- *		? ?, ?
+ * Programmer:  Kent Yang
  *
  *-------------------------------------------------------------------------
  */
@@ -627,22 +624,21 @@ done:
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5Pset_dxpl_mpio_chunk_opt_ratio
+ * Function:    H5Pset_dxpl_mpio_chunk_opt_ratio
  *
- * Purpose:	To set a threshold for doing collective I/O for each chunk
+ * Purpose:     To set a threshold for doing collective I/O for each chunk
  *
- * Note:	The library will calculate the percentage of the number of
- *		process holding selections at each chunk. If that percentage
- *		of number of process in the individual chunk is greater than
- *		the threshold set by the user, the library will do collective
- *		chunk I/O for this chunk; otherwise, independent I/O will be
- *		done for this chunk.
+ * Note:        The library will calculate the percentage of the number of
+ *              process holding selections at each chunk. If that percentage
+ *              of number of process in the individual chunk is greater than
+ *              the threshold set by the user, the library will do collective
+ *              chunk I/O for this chunk; otherwise, independent I/O will be
+ *              done for this chunk.
  *
- * Return:	Success:	Non-negative
- * 		Failure:	Negative
+ * Return:      Success:    Non-negative
+ *              Failure:    Negative
  *
- * Programmer:	Kent Yang
- *		? ?, ?
+ * Programmer:  Kent Yang
  *
  *-------------------------------------------------------------------------
  */
@@ -671,16 +667,16 @@ done:
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5FD__mpio_fapl_get
+ * Function:    H5FD__mpio_fapl_get
  *
- * Purpose:	Returns a file access property list which could be used to
- *		create another file the same as this one.
+ * Purpose:     Returns a file access property list which could be used to
+ *              create another file the same as this one.
  *
- * Return:	Success:	Ptr to new file access property list with all
- *				fields copied from the file pointer.
- *		Failure:	NULL
+ * Return:      Success:    Ptr to new file access property list with all
+ *                          fields copied from the file pointer.
+ *              Failure:    NULL
  *
- * Programmer:	Robb Matzke
+ * Programmer:  Robb Matzke
  *              Friday, August 13, 1999
  *
  *-------------------------------------------------------------------------
@@ -688,9 +684,9 @@ done:
 static void *
 H5FD__mpio_fapl_get(H5FD_t *_file)
 {
-    H5FD_mpio_t		*file = (H5FD_mpio_t*)_file;
-    H5FD_mpio_fapl_t	*fa = NULL;
-    void      *ret_value;       /* Return value */
+    H5FD_mpio_t         *file = (H5FD_mpio_t*)_file;
+    H5FD_mpio_fapl_t    *fa = NULL;
+    void                *ret_value = NULL;       /* Return value */
 
     FUNC_ENTER_STATIC
 
@@ -701,28 +697,38 @@ H5FD__mpio_fapl_get(H5FD_t *_file)
     /* Check arguments */
     if(NULL == (fa = (H5FD_mpio_fapl_t *)H5MM_calloc(sizeof(H5FD_mpio_fapl_t))))
         HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed")
+    fa->comm = MPI_COMM_NULL;
+    fa->info = MPI_INFO_NULL;
 
-    /* Duplicate communicator and Info object. */
-    if(FAIL == H5FD_mpi_comm_info_dup(file->comm, file->info, &fa->comm, &fa->info))
-	HGOTO_ERROR(H5E_INTERNAL, H5E_CANTCOPY, NULL, "Communicator/Info duplicate failed")
+    /* Duplicate MPI communicator and info */
+    if(FAIL == H5_mpi_comm_dup(file->comm, &fa->comm))
+        HGOTO_ERROR(H5E_INTERNAL, H5E_CANTCOPY, NULL, "communicator duplicate failed")
+    if(FAIL == H5_mpi_info_dup(file->info, &fa->info))
+        HGOTO_ERROR(H5E_INTERNAL, H5E_CANTCOPY, NULL, "info duplicate failed")
 
     /* Set return value */
     ret_value = fa;
 
 done:
+    /* Clean up badness if we're failing */
+    if(NULL == ret_value && fa) {
+        H5_mpi_comm_free(&fa->comm);
+        H5_mpi_info_free(&fa->info);
+        H5MM_xfree(fa);
+    }
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5FD__mpio_fapl_get() */
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5FD__mpio_fapl_copy
+ * Function:    H5FD__mpio_fapl_copy
  *
- * Purpose:	Copies the mpio-specific file access properties.
+ * Purpose:     Copies the mpio-specific file access properties.
  *
- * Return:	Success:	Ptr to a new property list
- *		Failure:	NULL
+ * Return:      Success:    Ptr to a new property list
+ *              Failure:    NULL
  *
- * Programmer:	Albert Cheng
+ * Programmer:  Albert Cheng
  *              Jan  8, 2003
  *
  *-------------------------------------------------------------------------
@@ -730,9 +736,9 @@ done:
 static void *
 H5FD__mpio_fapl_copy(const void *_old_fa)
 {
-    const H5FD_mpio_fapl_t *old_fa = (const H5FD_mpio_fapl_t*)_old_fa;
-    H5FD_mpio_fapl_t	*new_fa = NULL;
-    void		*ret_value = NULL;
+    const H5FD_mpio_fapl_t  *old_fa = (const H5FD_mpio_fapl_t*)_old_fa;
+    H5FD_mpio_fapl_t        *new_fa = NULL;
+    void                    *ret_value = NULL;
 
     FUNC_ENTER_STATIC
 
@@ -747,18 +753,22 @@ if(H5FD_mpio_Debug[(int)'t'])
     /* Copy the general information */
     H5MM_memcpy(new_fa, old_fa, sizeof(H5FD_mpio_fapl_t));
 
-    /* Duplicate communicator and Info object. */
-    if(H5FD_mpi_comm_info_dup(old_fa->comm, old_fa->info, &new_fa->comm, &new_fa->info) < 0)
-	HGOTO_ERROR(H5E_INTERNAL, H5E_CANTCOPY, NULL, "Communicator/Info duplicate failed")
+    /* Duplicate MPI communicator and info */
+    if(H5_mpi_comm_dup(old_fa->comm, &new_fa->comm) < 0)
+        HGOTO_ERROR(H5E_INTERNAL, H5E_CANTCOPY, NULL, "communicator duplicate failed")
+    if(H5_mpi_info_dup(old_fa->info, &new_fa->info) < 0)
+        HGOTO_ERROR(H5E_INTERNAL, H5E_CANTCOPY, NULL, "info duplicate failed")
 
     /* Set return value */
     ret_value = new_fa;
 
 done:
-    if(NULL == ret_value)
-	/* cleanup */
-	if(new_fa)
-	    H5MM_xfree(new_fa);
+    /* Clean up badness if we're failing */
+    if(NULL == ret_value && new_fa) {
+        H5_mpi_comm_free(&new_fa->comm);
+        H5_mpi_info_free(&new_fa->info);
+        H5MM_xfree(new_fa);
+    }
 
 #ifdef H5FDmpio_DEBUG
 if(H5FD_mpio_Debug[(int)'t'])
@@ -770,14 +780,13 @@ if(H5FD_mpio_Debug[(int)'t'])
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5FD__mpio_fapl_free
+ * Function:    H5FD__mpio_fapl_free
  *
- * Purpose:	Frees the mpio-specific file access properties.
+ * Purpose:     Frees the mpio-specific file access properties.
  *
- * Return:	Success:	0
- *		Failure:	-1
+ * Return:      SUCCEED/FAIL
  *
- * Programmer:	Albert Cheng
+ * Programmer:  Albert Cheng
  *              Jan  8, 2003
  *
  *-------------------------------------------------------------------------
@@ -785,10 +794,9 @@ if(H5FD_mpio_Debug[(int)'t'])
 static herr_t
 H5FD__mpio_fapl_free(void *_fa)
 {
-    H5FD_mpio_fapl_t	*fa = (H5FD_mpio_fapl_t*)_fa;
-    herr_t		ret_value = SUCCEED;
+    H5FD_mpio_fapl_t    *fa = (H5FD_mpio_fapl_t*)_fa;
 
-    FUNC_ENTER_STATIC
+    FUNC_ENTER_STATIC_NOERR
 
 #ifdef H5FDmpio_DEBUG
 if(H5FD_mpio_Debug[(int)'t'])
@@ -800,7 +808,8 @@ if(H5FD_mpio_Debug[(int)'t'])
 
     /* Free the internal communicator and INFO object */
     HDassert(MPI_COMM_NULL != fa->comm);
-    H5FD_mpi_comm_info_free(&fa->comm, &fa->info);
+    H5_mpi_comm_free(&fa->comm);
+    H5_mpi_info_free(&fa->info);
     H5MM_xfree(fa);
 
 #ifdef H5FDmpio_DEBUG
@@ -808,21 +817,19 @@ if(H5FD_mpio_Debug[(int)'t'])
     HDfprintf(stderr, "%s: leaving\n", FUNC);
 #endif
 
-    FUNC_LEAVE_NOAPI(ret_value)
+    FUNC_LEAVE_NOAPI(SUCCEED)
 } /* end H5FD__mpio_fapl_free() */
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5FD_set_mpio_atomicity
- *
- * Purpose:	Sets the atomicity mode
+ * Function:    H5FD_set_mpio_atomicity
  *
- * Return:	Success:	Non-negative
+ * Purpose:     Sets the atomicity mode
  *
- * 		Failure:	Negative
+ * Return:      SUCCEED/FAIL
  *
- * Programmer:	Mohamad Chaarawi
- *		Feb 14, 2012
+ * Programmer:  Mohamad Chaarawi
+ *              Feb 14, 2012
  *
  *-------------------------------------------------------------------------
  */
@@ -838,7 +845,7 @@ H5FD_set_mpio_atomicity(H5FD_t *_file, hbool_t flag)
 
 #ifdef H5FDmpio_DEBUG
     if(H5FD_mpio_Debug[(int)'t'])
-    	HDfprintf(stdout, "%s: Entering\n", FUNC);
+        HDfprintf(stdout, "%s: Entering\n", FUNC);
 #endif
 
     if(FALSE == flag)
@@ -853,7 +860,7 @@ H5FD_set_mpio_atomicity(H5FD_t *_file, hbool_t flag)
 done:
 #ifdef H5FDmpio_DEBUG
     if(H5FD_mpio_Debug[(int)'t'])
-    	HDfprintf(stdout, "%s: Leaving\n", FUNC);
+        HDfprintf(stdout, "%s: Leaving\n", FUNC);
 #endif
 
     FUNC_LEAVE_NOAPI(ret_value)
@@ -861,16 +868,14 @@ done:
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5FD_get_mpio_atomicity
- *
- * Purpose:	Returns the atomicity mode
+ * Function:    H5FD_get_mpio_atomicity
  *
- * Return:	Success:	Non-negative
+ * Purpose:     Returns the atomicity mode
  *
- * 		Failure:	Negative
+ * Return:      SUCCEED/FAIL
  *
- * Programmer:	Mohamad Chaarawi
- *		Feb 14, 2012
+ * Programmer:  Mohamad Chaarawi
+ *              Feb 14, 2012
  *
  *-------------------------------------------------------------------------
  */
@@ -886,7 +891,7 @@ H5FD_get_mpio_atomicity(H5FD_t *_file, hbool_t *flag)
 
 #ifdef H5FDmpio_DEBUG
     if(H5FD_mpio_Debug[(int)'t'])
-    	HDfprintf(stdout, "%s: Entering\n", FUNC);
+        HDfprintf(stdout, "%s: Entering\n", FUNC);
 #endif
 
     /* Get atomicity value */
@@ -901,7 +906,7 @@ H5FD_get_mpio_atomicity(H5FD_t *_file, hbool_t *flag)
 done:
 #ifdef H5FDmpio_DEBUG
     if(H5FD_mpio_Debug[(int)'t'])
-    	HDfprintf(stdout, "%s: Leaving\n", FUNC);
+        HDfprintf(stdout, "%s: Leaving\n", FUNC);
 #endif
 
     FUNC_LEAVE_NOAPI(ret_value)
@@ -912,14 +917,14 @@ done:
  * Function:    H5FD__mpio_open
  *
  * Purpose:     Opens a file with name NAME.  The FLAGS are a bit field with
- *		purpose similar to the second argument of open(2) and which
- *		are defined in H5Fpublic.h. The file access property list
- *		FAPL_ID contains the properties driver properties and MAXADDR
- *		is the largest address which this file will be expected to
- *		access.  This is collective.
+ *              purpose similar to the second argument of open(2) and which
+ *              are defined in H5Fpublic.h. The file access property list
+ *              FAPL_ID contains the properties driver properties and MAXADDR
+ *              is the largest address which this file will be expected to
+ *              access.  This is collective.
  *
- * Return:      Success:        A new file pointer.
- *              Failure:        NULL
+ * Return:      Success:    A new file pointer
+ *              Failure:    NULL
  *
  * Programmer:  Robert Kim Yates
  *              January 30, 1998
@@ -943,30 +948,32 @@ H5FD__mpio_open(const char *name, unsigned flags, hid_t fapl_id,
     H5P_genplist_t *plist;      /* Property list pointer */
     MPI_Comm                    comm_dup = MPI_COMM_NULL;
     MPI_Info                    info_dup = MPI_INFO_NULL;
-    H5FD_t			*ret_value;     /* Return value */
+    H5FD_t			*ret_value = NULL;     /* Return value */
 
     FUNC_ENTER_STATIC
 
 #ifdef H5FDmpio_DEBUG
     if(H5FD_mpio_Debug[(int)'t'])
-    	HDfprintf(stdout, "%s: Entering - name = \"%s\", flags = 0x%x, fapl_id = %d, maxaddr = %lu\n", FUNC, name, flags, (int)fapl_id, (unsigned long)maxaddr);
+        HDfprintf(stdout, "%s: Entering - name = \"%s\", flags = 0x%x, fapl_id = %d, maxaddr = %lu\n", FUNC, name, flags, (int)fapl_id, (unsigned long)maxaddr);
 #endif
 
     /* Obtain a pointer to mpio-specific file access properties */
     if(NULL == (plist = H5P_object_verify(fapl_id, H5P_FILE_ACCESS)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, NULL, "not a file access property list")
     if(H5P_FILE_ACCESS_DEFAULT == fapl_id || H5FD_MPIO != H5P_peek_driver(plist)) {
-	_fa.comm = MPI_COMM_SELF; /*default*/
-	_fa.info = MPI_INFO_NULL; /*default*/
-	fa = &_fa;
+        _fa.comm = MPI_COMM_SELF; /*default*/
+        _fa.info = MPI_INFO_NULL; /*default*/
+        fa = &_fa;
     } /* end if */
     else
         if(NULL == (fa = (const H5FD_mpio_fapl_t *)H5P_peek_driver_info(plist)))
-	    HGOTO_ERROR(H5E_PLIST, H5E_BADVALUE, NULL, "bad VFL driver info")
+            HGOTO_ERROR(H5E_PLIST, H5E_BADVALUE, NULL, "bad VFL driver info")
 
-    /* Duplicate communicator and Info object for use by this file. */
-    if(FAIL == H5FD_mpi_comm_info_dup(fa->comm, fa->info, &comm_dup, &info_dup))
-	HGOTO_ERROR(H5E_INTERNAL, H5E_CANTCOPY, NULL, "Communicator/Info duplicate failed")
+    /* Duplicate MPI communicator and info */
+    if(FAIL == H5_mpi_comm_dup(fa->comm, &comm_dup))
+        HGOTO_ERROR(H5E_INTERNAL, H5E_CANTCOPY, NULL, "communicator duplicate failed")
+    if(FAIL == H5_mpi_info_dup(fa->info, &info_dup))
+        HGOTO_ERROR(H5E_INTERNAL, H5E_CANTCOPY, NULL, "info duplicate failed")
 
     /* convert HDF5 flags to MPI-IO flags */
     /* some combinations are illegal; let MPI-IO figure it out */
@@ -1046,12 +1053,10 @@ done:
     if(ret_value == NULL) {
         if(file_opened)
             MPI_File_close(&fh);
-	if(MPI_COMM_NULL != comm_dup)
-	    MPI_Comm_free(&comm_dup);
-	if(MPI_INFO_NULL != info_dup)
-	    MPI_Info_free(&info_dup);
-	if(file)
-	    H5MM_xfree(file);
+        MPI_Comm_free(&comm_dup);
+        MPI_Info_free(&info_dup);
+        if(file)
+            H5MM_xfree(file);
     } /* end if */
 
 #ifdef H5FDmpio_DEBUG
@@ -1068,8 +1073,7 @@ done:
  *
  * Purpose:     Closes a file.  This is collective.
  *
- * Return:      Success:	Non-negative
- * 		Failure:	Negative
+ * Return:      SUCCEED/FAIL
  *
  * Programmer:  Unknown
  *              January 30, 1998
@@ -1079,15 +1083,15 @@ done:
 static herr_t
 H5FD__mpio_close(H5FD_t *_file)
 {
-    H5FD_mpio_t	*file = (H5FD_mpio_t*)_file;
-    int		mpi_code;	        /* MPI return code */
+    H5FD_mpio_t *file = (H5FD_mpio_t*)_file;
+    int         mpi_code;               /* MPI return code */
     herr_t      ret_value = SUCCEED;    /* Return value */
 
     FUNC_ENTER_STATIC
 
 #ifdef H5FDmpio_DEBUG
     if(H5FD_mpio_Debug[(int)'t'])
-    	HDfprintf(stdout, "%s: Entering\n", FUNC);
+        HDfprintf(stdout, "%s: Entering\n", FUNC);
 #endif
 
     /* Sanity checks */
@@ -1099,13 +1103,14 @@ H5FD__mpio_close(H5FD_t *_file)
         HMPI_GOTO_ERROR(FAIL, "MPI_File_close failed", mpi_code)
 
     /* Clean up other stuff */
-    H5FD_mpi_comm_info_free(&file->comm, &file->info);
+    H5_mpi_comm_free(&file->comm);
+    H5_mpi_info_free(&file->info);
     H5MM_xfree(file);
 
 done:
 #ifdef H5FDmpio_DEBUG
     if(H5FD_mpio_Debug[(int)'t'])
-    	HDfprintf(stdout, "%s: Leaving\n", FUNC);
+        HDfprintf(stdout, "%s: Leaving\n", FUNC);
 #endif
 
     FUNC_LEAVE_NOAPI(ret_value)
@@ -1113,15 +1118,14 @@ done:
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5FD__mpio_query
+ * Function:    H5FD__mpio_query
  *
- * Purpose:	Set the flags that this VFL driver is capable of supporting.
+ * Purpose:     Set the flags that this VFL driver is capable of supporting.
  *              (listed in H5FDpublic.h)
  *
- * Return:	Success:	non-negative
- *		Failure:	negative
+ * Return:      SUCCEED/FAIL
  *
- * Programmer:	Quincey Koziol
+ * Programmer:  Quincey Koziol
  *              Friday, August 25, 2000
  *
  *-------------------------------------------------------------------------
@@ -1129,7 +1133,7 @@ done:
 static herr_t
 H5FD__mpio_query(const H5FD_t H5_ATTR_UNUSED *_file, unsigned long *flags /* out */)
 {
-    FUNC_ENTER_STATIC
+    FUNC_ENTER_STATIC_NOERR
 
     /* Set the VFL feature flags that this driver supports */
     if(flags) {
@@ -1146,16 +1150,16 @@ H5FD__mpio_query(const H5FD_t H5_ATTR_UNUSED *_file, unsigned long *flags /* out
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5FD__mpio_get_eoa
+ * Function:    H5FD__mpio_get_eoa
  *
- * Purpose:	Gets the end-of-address marker for the file. The EOA marker
- *		is the first address past the last byte allocated in the
- *		format address space.
+ * Purpose:     Gets the end-of-address marker for the file. The EOA marker
+ *              is the first address past the last byte allocated in the
+ *              format address space.
  *
- * Return:	Success:	The end-of-address marker.
- *		Failure:	HADDR_UNDEF
+ * Return:      Success:    The end-of-address marker
+ *              Failure:    HADDR_UNDEF
  *
- * Programmer:	Robb Matzke
+ * Programmer:  Robb Matzke
  *              Friday, August  6, 1999
  *
  *-------------------------------------------------------------------------
@@ -1163,9 +1167,9 @@ H5FD__mpio_query(const H5FD_t H5_ATTR_UNUSED *_file, unsigned long *flags /* out
 static haddr_t
 H5FD__mpio_get_eoa(const H5FD_t *_file, H5FD_mem_t H5_ATTR_UNUSED type)
 {
-    const H5FD_mpio_t	*file = (const H5FD_mpio_t*)_file;
+    const H5FD_mpio_t   *file = (const H5FD_mpio_t*)_file;
 
-    FUNC_ENTER_STATIC
+    FUNC_ENTER_STATIC_NOERR
 
     /* Sanity checks */
     HDassert(file);
@@ -1176,16 +1180,15 @@ H5FD__mpio_get_eoa(const H5FD_t *_file, H5FD_mem_t H5_ATTR_UNUSED type)
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5FD__mpio_set_eoa
+ * Function:    H5FD__mpio_set_eoa
  *
- * Purpose:	Set the end-of-address marker for the file. This function is
- *		called shortly after an existing HDF5 file is opened in order
- *		to tell the driver where the end of the HDF5 data is located.
+ * Purpose:     Set the end-of-address marker for the file. This function is
+ *              called shortly after an existing HDF5 file is opened in order
+ *              to tell the driver where the end of the HDF5 data is located.
  *
- * Return:	Success:	0
- *		Failure:	-1
+ * Return:      SUCCEED/FAIL
  *
- * Programmer:	Robb Matzke
+ * Programmer:  Robb Matzke
  *              Friday, August 6, 1999
  *
  *-------------------------------------------------------------------------
@@ -1193,9 +1196,9 @@ H5FD__mpio_get_eoa(const H5FD_t *_file, H5FD_mem_t H5_ATTR_UNUSED type)
 static herr_t
 H5FD__mpio_set_eoa(H5FD_t *_file, H5FD_mem_t H5_ATTR_UNUSED type, haddr_t addr)
 {
-    H5FD_mpio_t	*file = (H5FD_mpio_t*)_file;
+    H5FD_mpio_t *file = (H5FD_mpio_t*)_file;
 
-    FUNC_ENTER_STATIC
+    FUNC_ENTER_STATIC_NOERR
 
     /* Sanity checks */
     HDassert(file);
@@ -1208,27 +1211,27 @@ H5FD__mpio_set_eoa(H5FD_t *_file, H5FD_mem_t H5_ATTR_UNUSED type, haddr_t addr)
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5FD__mpio_get_eof
+ * Function:    H5FD__mpio_get_eof
  *
- * Purpose:	Gets the end-of-file marker for the file. The EOF marker
- *		is the real size of the file.
+ * Purpose:     Gets the end-of-file marker for the file. The EOF marker
+ *              is the real size of the file.
  *
- *		The MPIO driver doesn't bother keeping this field updated
- *		since that's a relatively expensive operation. Fortunately
- *		the library only needs the EOF just after the file is opened
- *		in order to determine whether the file is empty, truncated,
- *		or okay.  Therefore, any MPIO I/O function will set its value
- *		to HADDR_UNDEF which is the error return value of this
- *		function.
+ *              The MPIO driver doesn't bother keeping this field updated
+ *              since that's a relatively expensive operation. Fortunately
+ *              the library only needs the EOF just after the file is opened
+ *              in order to determine whether the file is empty, truncated,
+ *              or okay.  Therefore, any MPIO I/O function will set its value
+ *              to HADDR_UNDEF which is the error return value of this
+ *              function.
  *
  *              Keeping the EOF updated (during write calls) is expensive
  *              because any process may extend the physical end of the
  *              file. -QAK
  *
- * Return:	Success:	The end-of-address marker.
- *		Failure:	HADDR_UNDEF
+ * Return:      Success:    The end-of-file marker
+ *              Failure:    HADDR_UNDEF
  *
- * Programmer:	Robb Matzke
+ * Programmer:  Robb Matzke
  *              Friday, August  6, 1999
  *
  *-------------------------------------------------------------------------
@@ -1236,9 +1239,9 @@ H5FD__mpio_set_eoa(H5FD_t *_file, H5FD_mem_t H5_ATTR_UNUSED type, haddr_t addr)
 static haddr_t
 H5FD__mpio_get_eof(const H5FD_t *_file, H5FD_mem_t H5_ATTR_UNUSED type)
 {
-    const H5FD_mpio_t	*file = (const H5FD_mpio_t*)_file;
+    const H5FD_mpio_t   *file = (const H5FD_mpio_t*)_file;
 
-    FUNC_ENTER_STATIC
+    FUNC_ENTER_STATIC_NOERR
 
     /* Sanity checks */
     HDassert(file);
@@ -1253,7 +1256,7 @@ H5FD__mpio_get_eof(const H5FD_t *_file, H5FD_mem_t H5_ATTR_UNUSED type)
  *
  * Purpose:        Returns the file handle of MPIO file driver.
  *
- * Returns:        Non-negative if succeed or negative if fails.
+ * Returns:        SUCCEED/FAIL
  *
  * Programmer:     Raymond Lu
  *                 Sept. 16, 2002
@@ -1283,13 +1286,11 @@ done:
  *
  * Purpose:        Returns the file info of MPIO file driver.
  *
- * Returns:        Non-negative if succeed or negative if fails.
+ * Returns:        SUCCEED/FAIL
  *
  * Programmer:     John Mainzer
  *                 April 4, 2017
  *
- * Modifications:
- *
  *-------------------------------------------------------------------------
 */
 static herr_t
@@ -1312,23 +1313,23 @@ done:
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5FD__mpio_read
+ * Function:    H5FD__mpio_read
  *
- * Purpose:	Reads SIZE bytes of data from FILE beginning at address ADDR
- *		into buffer BUF according to data transfer properties in
- *		DXPL_ID using potentially complex file and buffer types to
- *		effect the transfer.
+ * Purpose:     Reads SIZE bytes of data from FILE beginning at address ADDR
+ *              into buffer BUF according to data transfer properties in
+ *              DXPL_ID using potentially complex file and buffer types to
+ *              effect the transfer.
  *
- *		Reading past the end of the MPI file returns zeros instead of
- *		failing.  MPI is able to coalesce requests from different
- *		processes (collective or independent).
+ *              Reading past the end of the MPI file returns zeros instead of
+ *              failing.  MPI is able to coalesce requests from different
+ *              processes (collective or independent).
  *
- * Return:	Success:	Zero. Result is stored in caller-supplied
- *				buffer BUF.
+ * Return:      Success:    SUCCEED. Result is stored in caller-supplied
+ *                          buffer BUF.
  *
- *		Failure:	-1, Contents of buffer BUF are undefined.
+ *              Failure:    FAIL. Contents of buffer BUF are undefined.
  *
- * Programmer:	rky, 1998-01-30
+ * Programmer:  rky, 1998-01-30
  *
  *-------------------------------------------------------------------------
  */
@@ -1531,22 +1532,22 @@ done:
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5FD__mpio_write
+ * Function:    H5FD__mpio_write
  *
- * Purpose:	Writes SIZE bytes of data to FILE beginning at address ADDR
- *		from buffer BUF according to data transfer properties in
- *		DXPL_ID using potentially complex file and buffer types to
- *		effect the transfer.
+ * Purpose:     Writes SIZE bytes of data to FILE beginning at address ADDR
+ *              from buffer BUF according to data transfer properties in
+ *              DXPL_ID using potentially complex file and buffer types to
+ *              effect the transfer.
  *
- *		MPI is able to coalesce requests from different processes
- *		(collective and independent).
+ *              MPI is able to coalesce requests from different processes
+ *              (collective and independent).
  *
- * Return:	Success:	Zero. USE_TYPES and OLD_USE_TYPES in the
- *				access params are altered.
- *		Failure:	-1, USE_TYPES and OLD_USE_TYPES in the
- *				access params may be altered.
+ * Return:      Success:    SUCCEED. USE_TYPES and OLD_USE_TYPES in the
+ *                          access params are altered.
+ *              Failure:    FAIL. USE_TYPES and OLD_USE_TYPES in the
+ *                          access params may be altered.
  *
- * Programmer:	Robert Kim Yates
+ * Programmer:  Robert Kim Yates
  *              January 30, 1998
  *
  *-------------------------------------------------------------------------
@@ -1555,13 +1556,13 @@ static herr_t
 H5FD__mpio_write(H5FD_t *_file, H5FD_mem_t type, hid_t H5_ATTR_UNUSED dxpl_id,
     haddr_t addr, size_t size, const void *buf)
 {
-    H5FD_mpio_t			*file = (H5FD_mpio_t*)_file;
-    MPI_Offset 		 	mpi_off;
-    MPI_Status  		mpi_stat;       /* Status from I/O operation */
-    MPI_Datatype		buf_type = MPI_BYTE;      /* MPI description of the selection in memory */
-    int			        mpi_code;	/* MPI return code */
+    H5FD_mpio_t                 *file = (H5FD_mpio_t*)_file;
+    MPI_Offset                  mpi_off;
+    MPI_Status                  mpi_stat;       /* Status from I/O operation */
+    MPI_Datatype                buf_type = MPI_BYTE;      /* MPI description of the selection in memory */
+    int                         mpi_code;   /* MPI return code */
 #if MPI_VERSION >= 3
-    MPI_Count         		bytes_written;
+    MPI_Count                   bytes_written;
     MPI_Count                   type_size;      /* MPI datatype used for I/O's size */
     MPI_Count                   io_size;        /* Actual number of bytes requested */
 #else
@@ -1570,15 +1571,15 @@ H5FD__mpio_write(H5FD_t *_file, H5FD_mem_t type, hid_t H5_ATTR_UNUSED dxpl_id,
     int                         io_size;        /* Actual number of bytes requested */
 #endif
     int                         size_i;
-    hbool_t			use_view_this_time = FALSE;
+    hbool_t                     use_view_this_time = FALSE;
     H5FD_mpio_xfer_t            xfer_mode;   /* I/O transfer mode */
-    herr_t              	ret_value = SUCCEED;
+    herr_t                      ret_value = SUCCEED;
 
     FUNC_ENTER_STATIC
 
 #ifdef H5FDmpio_DEBUG
     if(H5FD_mpio_Debug[(int)'t'])
-    	HDfprintf(stdout, "%s: Entering\n", FUNC);
+        HDfprintf(stdout, "%s: Entering\n", FUNC);
 #endif
 
     /* Sanity checks */
@@ -1615,7 +1616,7 @@ H5FD__mpio_write(H5FD_t *_file, H5FD_mem_t type, hid_t H5_ATTR_UNUSED dxpl_id,
      * could mean "use MPI_BYTE" by convention).
      */
     if(xfer_mode == H5FD_MPIO_COLLECTIVE) {
-        MPI_Datatype		file_type;
+        MPI_Datatype    file_type;
 
         /* Remember that views are used */
         use_view_this_time = TRUE;
@@ -1713,7 +1714,7 @@ H5FD__mpio_write(H5FD_t *_file, H5FD_mem_t type, hid_t H5_ATTR_UNUSED dxpl_id,
 done:
 #ifdef H5FDmpio_DEBUG
     if(H5FD_mpio_Debug[(int)'t'])
-    	HDfprintf(stdout, "%s: Leaving, proc %d: ret_value = %d\n", FUNC, file->mpi_rank, ret_value );
+        HDfprintf(stdout, "%s: Leaving, proc %d: ret_value = %d\n", FUNC, file->mpi_rank, ret_value );
 #endif
 
     FUNC_LEAVE_NOAPI(ret_value)
@@ -1725,9 +1726,7 @@ done:
  *
  * Purpose:     Makes sure that all data is on disk.  This is collective.
  *
- * Return:      Success:	Non-negative
- *
- * 		Failure:	Negative
+ * Return:      SUCCEED/FAIL
  *
  * Programmer:  Robb Matzke
  *              January 30, 1998
@@ -1737,15 +1736,15 @@ done:
 static herr_t
 H5FD__mpio_flush(H5FD_t *_file, hid_t H5_ATTR_UNUSED dxpl_id, hbool_t closing)
 {
-    H5FD_mpio_t		*file = (H5FD_mpio_t*)_file;
-    int			mpi_code;	/* mpi return code */
-    herr_t              ret_value = SUCCEED;
+    H5FD_mpio_t     *file = (H5FD_mpio_t*)_file;
+    int             mpi_code;   /* mpi return code */
+    herr_t          ret_value = SUCCEED;
 
     FUNC_ENTER_STATIC
 
 #ifdef H5FDmpio_DEBUG
     if(H5FD_mpio_Debug[(int)'t'])
-    	HDfprintf(stdout, "%s: Entering\n", FUNC);
+        HDfprintf(stdout, "%s: Entering\n", FUNC);
 #endif
 
     /* Sanity checks */
@@ -1760,7 +1759,7 @@ H5FD__mpio_flush(H5FD_t *_file, hid_t H5_ATTR_UNUSED dxpl_id, hbool_t closing)
 done:
 #ifdef H5FDmpio_DEBUG
     if(H5FD_mpio_Debug[(int)'t'])
-    	HDfprintf(stdout, "%s: Leaving\n", FUNC);
+        HDfprintf(stdout, "%s: Leaving\n", FUNC);
 #endif
 
     FUNC_LEAVE_NOAPI(ret_value)
@@ -1782,8 +1781,7 @@ done:
  *              only call MPI_File_set_size() if this value disagrees 
  *              with the current eoa.
  *
- * Return:      Success:	Non-negative
- * 		Failure:	Negative
+ * Return:      SUCCEED/FAIL
  *
  * Programmer:  Quincey Koziol
  *              January 31, 2008
@@ -1793,14 +1791,14 @@ done:
 static herr_t
 H5FD__mpio_truncate(H5FD_t *_file, hid_t H5_ATTR_UNUSED dxpl_id, hbool_t H5_ATTR_UNUSED closing)
 {
-    H5FD_mpio_t	*file = (H5FD_mpio_t*)_file;
+    H5FD_mpio_t *file = (H5FD_mpio_t*)_file;
     herr_t      ret_value = SUCCEED;
 
     FUNC_ENTER_STATIC
 
 #ifdef H5FDmpio_DEBUG
     if(H5FD_mpio_Debug[(int)'t'])
-    	HDfprintf(stdout, "%s: Entering\n", FUNC);
+        HDfprintf(stdout, "%s: Entering\n", FUNC);
 #endif
 
     /* Sanity checks */
@@ -1869,7 +1867,7 @@ H5FD__mpio_truncate(H5FD_t *_file, hid_t H5_ATTR_UNUSED dxpl_id, hbool_t H5_ATTR
 done:
 #ifdef H5FDmpio_DEBUG
     if(H5FD_mpio_Debug[(int)'t'])
-    	HDfprintf(stdout, "%s: Leaving\n", FUNC);
+        HDfprintf(stdout, "%s: Leaving\n", FUNC);
 #endif
 
     FUNC_LEAVE_NOAPI(ret_value)
@@ -1877,14 +1875,14 @@ done:
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5FD__mpio_mpi_rank
+ * Function:    H5FD__mpio_mpi_rank
  *
- * Purpose:	Returns the MPI rank for a process
+ * Purpose:     Returns the MPI rank for a process
  *
- * Return:	Success: non-negative
- *		Failure: negative
+ * Return:      Success: non-negative
+ *              Failure: negative
  *
- * Programmer:	Quincey Koziol
+ * Programmer:  Quincey Koziol
  *              Thursday, May 16, 2002
  *
  *-------------------------------------------------------------------------
@@ -1892,9 +1890,9 @@ done:
 static int
 H5FD__mpio_mpi_rank(const H5FD_t *_file)
 {
-    const H5FD_mpio_t	*file = (const H5FD_mpio_t*)_file;
+    const H5FD_mpio_t   *file = (const H5FD_mpio_t*)_file;
 
-    FUNC_ENTER_STATIC
+    FUNC_ENTER_STATIC_NOERR
 
     /* Sanity checks */
     HDassert(file);
@@ -1905,14 +1903,14 @@ H5FD__mpio_mpi_rank(const H5FD_t *_file)
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5FD__mpio_mpi_size
+ * Function:    H5FD__mpio_mpi_size
  *
- * Purpose:	Returns the number of MPI processes
+ * Purpose:     Returns the number of MPI processes
  *
- * Return:	Success: non-negative
- *		Failure: negative
+ * Return:      Success: non-negative
+ *              Failure: negative
  *
- * Programmer:	Quincey Koziol
+ * Programmer:  Quincey Koziol
  *              Thursday, May 16, 2002
  *
  *-------------------------------------------------------------------------
@@ -1920,9 +1918,9 @@ H5FD__mpio_mpi_rank(const H5FD_t *_file)
 static int
 H5FD__mpio_mpi_size(const H5FD_t *_file)
 {
-    const H5FD_mpio_t	*file = (const H5FD_mpio_t*)_file;
+    const H5FD_mpio_t   *file = (const H5FD_mpio_t*)_file;
 
-    FUNC_ENTER_STATIC
+    FUNC_ENTER_STATIC_NOERR
 
     /* Sanity checks */
     HDassert(file);
@@ -1933,15 +1931,14 @@ H5FD__mpio_mpi_size(const H5FD_t *_file)
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5FD__mpio_communicator
- *
- * Purpose:	Returns the MPI communicator for the file.
+ * Function:    H5FD__mpio_communicator
  *
- * Return:	Success:	The communicator
+ * Purpose:     Returns the MPI communicator for the file.
  *
- *		Failure:	NULL
+ * Return:      Success:    The communicator
+ *              Failure:    Can't fail
  *
- * Programmer:	Robb Matzke
+ * Programmer:  Robb Matzke
  *              Monday, August  9, 1999
  *
  *-------------------------------------------------------------------------
@@ -1949,9 +1946,9 @@ H5FD__mpio_mpi_size(const H5FD_t *_file)
 static MPI_Comm
 H5FD__mpio_communicator(const H5FD_t *_file)
 {
-    const H5FD_mpio_t	*file = (const H5FD_mpio_t*)_file;
+    const H5FD_mpio_t   *file = (const H5FD_mpio_t*)_file;
 
-    FUNC_ENTER_STATIC
+    FUNC_ENTER_STATIC_NOERR
 
     /* Sanity checks */
     HDassert(file);
@@ -1971,8 +1968,6 @@ H5FD__mpio_communicator(const H5FD_t *_file)
  * Programmer:     John Mainzer
  *                 April 4, 2017
  *
- * Modifications:
- *
  *-------------------------------------------------------------------------
 */
 static herr_t
diff --git a/src/H5FDprivate.h b/src/H5FDprivate.h
index c79d676..0db66af 100644
--- a/src/H5FDprivate.h
+++ b/src/H5FDprivate.h
@@ -160,9 +160,6 @@ H5_DLL herr_t H5FD_set_paged_aggr(H5FD_t *file, hbool_t paged);
 /* General routines */
 H5_DLL haddr_t H5FD_mpi_MPIOff_to_haddr(MPI_Offset mpi_off);
 H5_DLL herr_t H5FD_mpi_haddr_to_MPIOff(haddr_t addr, MPI_Offset *mpi_off/*out*/);
-H5_DLL herr_t H5FD_mpi_comm_info_dup(MPI_Comm comm, MPI_Info info,
-				MPI_Comm *comm_new, MPI_Info *info_new);
-H5_DLL herr_t H5FD_mpi_comm_info_free(MPI_Comm *comm, MPI_Info *info);
 #ifdef NOT_YET
 H5_DLL herr_t H5FD_mpio_wait_for_left_neighbor(H5FD_t *file);
 H5_DLL herr_t H5FD_mpio_signal_right_neighbor(H5FD_t *file);
diff --git a/src/H5FDros3.c b/src/H5FDros3.c
index 86642aa..18f1f91 100644
--- a/src/H5FDros3.c
+++ b/src/H5FDros3.c
@@ -11,12 +11,12 @@
  * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
 /*
- * Read-Only S3 Virtual File Driver (VFD)                                   
+ * Read-Only S3 Virtual File Driver (VFD)
  *
  * Programmer: Jacob Smith <jake.smith@hdfgroup.org>
  *             2017-10-13
  *
- * Purpose: 
+ * Purpose:
  *
  *     Provide read-only access to files hosted on Amazon's S3 service.
  *     Relies on "s3comms" utility layer to implement the AWS REST API.
@@ -137,9 +137,9 @@ typedef struct {
  *
  * Purpose:
  *
- *     H5FD_ros3_t is a structure used to store all information needed to 
+ *     H5FD_ros3_t is a structure used to store all information needed to
  *     maintain R/O access to a single HDF5 file that has been stored as a
- *     S3 object.  This structure is created when such a file is "opened" and 
+ *     S3 object.  This structure is created when such a file is "opened" and
  *     discarded when it is "closed".
  *
  *     Presents an S3 object as a file to the HDF5 library.
@@ -154,7 +154,7 @@ typedef struct {
  *
  * `fa` (H5FD_ros3_fapl_t)
  *
- *     Instance of `H5FD_ros3_fapl_t` containing the S3 configuration data 
+ *     Instance of `H5FD_ros3_fapl_t` containing the S3 configuration data
  *     needed to "open" the HDF5 file.
  *
  * `eoa` (haddr_t)
@@ -163,9 +163,9 @@ typedef struct {
  *     equal the file size.
  *
  * `s3r_handle` (s3r_t *)
- *     
+ *
  *     Instance of S3 Request handle associated with the target resource.
- *     Responsible for communicating with remote host and presenting file 
+ *     Responsible for communicating with remote host and presenting file
  *     contents as indistinguishable from a file on the local filesystem.
  *
  * *** present only if ROS3_SATS is flagged to enable stats collection ***
@@ -211,10 +211,13 @@ typedef struct H5FD_ros3_t {
  * ADDR_OVERFLOW:   Checks whether a file address of type `haddr_t'
  *                  is too large to be represented by the second argument
  *                  of the file seek function.
+ *                  Only included if it may be used -- ROS3 VFD is enabled.
  *
  */
 #define MAXADDR (((haddr_t)1<<(8*sizeof(HDoff_t)-1))-1)
+#ifdef H5_HAVE_ROS3_VFD
 #define ADDR_OVERFLOW(A)    (HADDR_UNDEF==(A) || ((A) & ~(haddr_t)MAXADDR))
+#endif /* H5_HAVE_ROS3_VFD */
 
 /* Prototypes */
 static herr_t  H5FD_ros3_term(void);
@@ -229,13 +232,13 @@ static herr_t  H5FD_ros3_query(const H5FD_t *_f1, unsigned long *flags);
 static haddr_t H5FD_ros3_get_eoa(const H5FD_t *_file, H5FD_mem_t type);
 static herr_t  H5FD_ros3_set_eoa(H5FD_t *_file, H5FD_mem_t type, haddr_t addr);
 static haddr_t H5FD_ros3_get_eof(const H5FD_t *_file, H5FD_mem_t type);
-static herr_t  H5FD_ros3_get_handle(H5FD_t *_file, hid_t fapl, 
+static herr_t  H5FD_ros3_get_handle(H5FD_t *_file, hid_t fapl,
                                     void** file_handle);
-static herr_t  H5FD_ros3_read(H5FD_t *_file, H5FD_mem_t type, hid_t fapl_id, 
+static herr_t  H5FD_ros3_read(H5FD_t *_file, H5FD_mem_t type, hid_t fapl_id,
                                haddr_t addr, size_t size, void *buf);
-static herr_t  H5FD_ros3_write(H5FD_t *_file, H5FD_mem_t type, hid_t fapl_id, 
+static herr_t  H5FD_ros3_write(H5FD_t *_file, H5FD_mem_t type, hid_t fapl_id,
                                haddr_t addr, size_t size, const void *buf);
-static herr_t  H5FD_ros3_truncate(H5FD_t *_file, hid_t dxpl_id, 
+static herr_t  H5FD_ros3_truncate(H5FD_t *_file, hid_t dxpl_id,
                                   hbool_t closing);
 static herr_t  H5FD_ros3_lock(H5FD_t *_file, hbool_t rw);
 static herr_t  H5FD_ros3_unlock(H5FD_t *_file);
@@ -276,8 +279,10 @@ static const H5FD_class_t H5FD_ros3_g = {
     H5FD_FLMAP_DICHOTOMY        /* fl_map               */
 };
 
+#ifdef H5_HAVE_ROS3_VFD
 /* Declare a free list to manage the H5FD_ros3_t struct */
 H5FL_DEFINE_STATIC(H5FD_ros3_t);
+#endif /* H5_HAVE_ROS3_VFD */
 
 
 /*-------------------------------------------------------------------------
@@ -300,14 +305,14 @@ H5FD__init_package(void)
     FUNC_ENTER_STATIC
 
     if (H5FD_ros3_init() < 0) {
-        HGOTO_ERROR(H5E_VFL, H5E_CANTINIT, FAIL, 
+        HGOTO_ERROR(H5E_VFL, H5E_CANTINIT, FAIL,
                     "unable to initialize ros3 VFD")
     }
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
 
-} /* H5FD__init_package() */
+} /* end H5FD__init_package() */
 
 
 /*-------------------------------------------------------------------------
@@ -330,7 +335,7 @@ done:
 hid_t
 H5FD_ros3_init(void)
 {
-    hid_t ret_value = H5I_INVALID_HID; /* Return value */
+    hid_t ret_value = H5I_INVALID_HID;
 
     FUNC_ENTER_NOAPI(FAIL)
 
@@ -388,6 +393,7 @@ H5FD_ros3_term(void)
     H5FD_ROS3_g = 0;
 
     FUNC_LEAVE_NOAPI(SUCCEED)
+
 } /* end H5FD_ros3_term() */
 
 
@@ -395,8 +401,8 @@ H5FD_ros3_term(void)
  * Function:    H5Pset_fapl_ros3
  *
  * Purpose:     Modify the file access property list to use the H5FD_ROS3
- *              driver defined in this source file.  All driver specfic 
- *              properties are passed in as a pointer to a suitably 
+ *              driver defined in this source file.  All driver specfic
+ *              properties are passed in as a pointer to a suitably
  *              initialized instance of H5FD_ros3_fapl_t
  *
  * Return:      SUCCEED/FAIL
@@ -407,14 +413,12 @@ H5FD_ros3_term(void)
  *-------------------------------------------------------------------------
  */
 herr_t
-H5Pset_fapl_ros3(hid_t             fapl_id, 
+H5Pset_fapl_ros3(hid_t             fapl_id,
                  H5FD_ros3_fapl_t *fa)
 {
     H5P_genplist_t *plist     = NULL; /* Property list pointer */
     herr_t          ret_value = FAIL;
 
-
-
     FUNC_ENTER_API(FAIL)
     H5TRACE2("e", "i*x", fapl_id, fa);
 
@@ -425,21 +429,21 @@ H5Pset_fapl_ros3(hid_t             fapl_id,
 #endif
 
     plist = H5P_object_verify(fapl_id, H5P_FILE_ACCESS);
-    if (plist == NULL) { 
+    if (plist == NULL) {
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, \
                     "not a file access property list")
     }
 
-    if (FAIL == H5FD_ros3_validate_config(fa))
+    if (FAIL == H5FD_ros3_validate_config(fa)) {
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid ros3 config")
+    }
 
     ret_value = H5P_set_driver(plist, H5FD_ROS3, (void *)fa);
 
 done:
-
     FUNC_LEAVE_API(ret_value)
 
-} /* H5Pset_fapl_ros3() */
+} /* end H5Pset_fapl_ros3() */
 
 
 /*-------------------------------------------------------------------------
@@ -449,12 +453,12 @@ done:
  *              contains internally consistant data.  Return SUCCEED if so,
  *              and FAIL otherwise.
  *
- *              Note the difference between internally consistant and 
- *              correct.  As we will have to try to access the target 
+ *              Note the difference between internally consistant and
+ *              correct.  As we will have to try to access the target
  *              object to determine whether the supplied data is correct,
  *              we will settle for internal consistancy at this point
  *
- * Return:      SUCCEED if instance of H5FD_ros3_fapl_t contains internally 
+ * Return:      SUCCEED if instance of H5FD_ros3_fapl_t contains internally
  *              consistant data, FAIL otherwise.
  *
  * Programmer:  Jacob Smith
@@ -494,7 +498,7 @@ H5FD_ros3_validate_config(const H5FD_ros3_fapl_t * fa)
 done:
     FUNC_LEAVE_NOAPI(ret_value)
 
-} /* H5FD_ros3_validate_config() */
+} /* end H5FD_ros3_validate_config() */
 
 
 /*-------------------------------------------------------------------------
@@ -515,12 +519,12 @@ done:
  *-------------------------------------------------------------------------
  */
 herr_t
-H5Pget_fapl_ros3(hid_t             fapl_id, 
+H5Pget_fapl_ros3(hid_t             fapl_id,
                  H5FD_ros3_fapl_t *fa_out)
 {
-    const H5FD_ros3_fapl_t *fa;
-    H5P_genplist_t         *plist     = NULL;    /* Property list pointer */
-    herr_t                  ret_value = SUCCEED; /* Return value */
+    const H5FD_ros3_fapl_t *fa        = NULL;
+    H5P_genplist_t         *plist     = NULL;
+    herr_t                  ret_value = SUCCEED;
 
     FUNC_ENTER_API(FAIL)
     H5TRACE2("e", "i*x", fapl_id, fa_out);
@@ -529,8 +533,9 @@ H5Pget_fapl_ros3(hid_t             fapl_id,
     HDfprintf(stdout, "H5Pget_fapl_ros3() called.\n");
 #endif
 
-    if (fa_out == NULL)
+    if (fa_out == NULL) {
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "fa_out is NULL")
+    }
 
     plist = H5P_object_verify(fapl_id, H5P_FILE_ACCESS);
     if (plist == NULL) {
@@ -552,7 +557,7 @@ H5Pget_fapl_ros3(hid_t             fapl_id,
 done:
     FUNC_LEAVE_API(ret_value)
 
-} /* H5Pget_fapl_ros3() */
+} /* end H5Pget_fapl_ros3() */
 
 
 /*-------------------------------------------------------------------------
@@ -583,7 +588,7 @@ H5FD_ros3_fapl_get(H5FD_t *_file)
 
     fa = (H5FD_ros3_fapl_t *)H5MM_calloc(sizeof(H5FD_ros3_fapl_t));
     if (fa == NULL) {
-        HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, 
+        HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL,
                     "memory allocation failed")
     }
 
@@ -595,12 +600,13 @@ H5FD_ros3_fapl_get(H5FD_t *_file)
 
 done:
     if (ret_value == NULL) {
-        if (fa != NULL)
-            H5MM_xfree(fa); 
+        if (fa != NULL) {
+            H5MM_xfree(fa);
+        }
     }
     FUNC_LEAVE_NOAPI(ret_value)
 
-} /* H5FD_ros3_fapl_get() */
+} /* end H5FD_ros3_fapl_get() */
 
 
 /*-------------------------------------------------------------------------
@@ -624,13 +630,13 @@ H5FD_ros3_fapl_copy(const void *_old_fa)
 {
     const H5FD_ros3_fapl_t *old_fa    = (const H5FD_ros3_fapl_t*)_old_fa;
     H5FD_ros3_fapl_t       *new_fa    = NULL;
-    void                   *ret_value = NULL;     /* Return value */
+    void                   *ret_value = NULL;
 
     FUNC_ENTER_NOAPI_NOINIT
 
     new_fa = (H5FD_ros3_fapl_t *)H5MM_malloc(sizeof(H5FD_ros3_fapl_t));
     if (new_fa == NULL) {
-        HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, 
+        HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL,
                     "memory allocation failed");
     }
 
@@ -639,12 +645,13 @@ H5FD_ros3_fapl_copy(const void *_old_fa)
 
 done:
     if (ret_value == NULL) {
-        if (new_fa != NULL)
+        if (new_fa != NULL) {
             H5MM_xfree(new_fa);
+        }
     }
     FUNC_LEAVE_NOAPI(ret_value)
 
-} /* H5FD_ros3_fapl_copy() */
+} /* end H5FD_ros3_fapl_copy() */
 
 
 /*-------------------------------------------------------------------------
@@ -668,13 +675,13 @@ H5FD_ros3_fapl_free(void *_fa)
 
     FUNC_ENTER_NOAPI_NOINIT_NOERR
 
-    HDassert(fa != NULL); /* sanity check */ 
+    HDassert(fa != NULL); /* sanity check */
 
     H5MM_xfree(fa);
 
     FUNC_LEAVE_NOAPI(SUCCEED)
 
-} /* H5FD_ros3_fapl_free() */
+} /* end H5FD_ros3_fapl_free() */
 
 #if ROS3_STATS
 
@@ -707,7 +714,6 @@ ros3_reset_stats(H5FD_ros3_t *file)
     unsigned i         = 0;
     herr_t   ret_value = SUCCEED;
 
-
     FUNC_ENTER_NOAPI_NOINIT
 
 #if ROS3_DEBUG
@@ -734,7 +740,8 @@ ros3_reset_stats(H5FD_ros3_t *file)
 done:
     FUNC_LEAVE_NOAPI(ret_value);
 
-} /* ros3_reset_stats */
+} /* end ros3_reset_stats() */
+
 #endif /* ROS3_STATS */
 
 
@@ -747,10 +754,10 @@ done:
  *     Create and/or opens a file as an HDF5 file.
  *
  *     Any flag except H5F_ACC_RDONLY will cause an error.
- * 
+ *
  *     Name (as received from `H5FD_open()`) must conform to web url:
  *         NAME   :: HTTP "://" DOMAIN [PORT] ["/" [URI] [QUERY] ]
- *         HTTP   :: "http" [ "s" ] 
+ *         HTTP   :: "http" [ "s" ]
  *         DOMAIN :: e.g., "mybucket.host.org"
  *         PORT   :: ":" <number> (e.g., ":9000" )
  *         URI    :: <string> (e.g., "path/to/resource.hd5" )
@@ -758,8 +765,8 @@ done:
  *
  * Return:
  *
- *     Success: A pointer to a new file data structure. 
- *              The public fields will be initialized by the caller, which is 
+ *     Success: A pointer to a new file data structure.
+ *              The public fields will be initialized by the caller, which is
  *              always H5FD_open().
  *
  *     Failure: NULL
@@ -771,32 +778,31 @@ done:
  *
  *-------------------------------------------------------------------------
  */
+#ifdef H5_HAVE_ROS3_VFD
+
 static H5FD_t *
-H5FD_ros3_open(const char *url, 
-               unsigned    flags, 
-               hid_t       fapl_id, 
-               haddr_t     maxaddr)
+H5FD_ros3_open(
+        const char *url,
+        unsigned    flags,
+        hid_t       fapl_id,
+        haddr_t     maxaddr)
 {
-#ifdef H5_HAVE_ROS3_VFD
     H5FD_ros3_t      *file      = NULL;
     struct tm        *now       = NULL;
     char              iso8601now[ISO8601_SIZE];
     unsigned char     signing_key[SHA256_DIGEST_LENGTH];
     s3r_t            *handle    = NULL;
     H5FD_ros3_fapl_t  fa;
-#endif
     H5FD_t           *ret_value = NULL;
 
 
 
     FUNC_ENTER_NOAPI_NOINIT
-#ifdef H5_HAVE_ROS3_VFD
 
 #if ROS3_DEBUG
     HDfprintf(stdout, "H5FD_ros3_open() called.\n");
 #endif
 
-
     /* Sanity check on file offsets */
     HDcompile_assert(sizeof(HDoff_t) >= sizeof(size_t));
 
@@ -837,7 +843,7 @@ H5FD_ros3_open(const char *url,
         if (FAIL == H5FD_s3comms_signing_key(signing_key,
                                              (const char *)fa.secret_key,
                                              (const char *)fa.aws_region,
-                                             (const char *)iso8601now) ) 
+                                             (const char *)iso8601now) )
         {
             HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, NULL,
                         "problem while computing signing key")
@@ -854,17 +860,17 @@ H5FD_ros3_open(const char *url,
 
     if (handle == NULL) {
         /* If we want to check CURL's say on the matter in a controlled
-         * fashion, this is the place to do it, but would need to make a 
+         * fashion, this is the place to do it, but would need to make a
          * few minor changes to s3comms `s3r_t` and `s3r_read()`.
-         */ 
+         */
         HGOTO_ERROR(H5E_VFL, H5E_CANTOPENFILE, NULL, "could not open");
     }
 
-    /* create new file struct 
+    /* create new file struct
      */
     file = H5FL_CALLOC(H5FD_ros3_t);
     if (file == NULL) {
-        HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, 
+        HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL,
                     "unable to allocate file struct")
     }
 
@@ -873,7 +879,7 @@ H5FD_ros3_open(const char *url,
 
 #if ROS3_STATS
     if (FAIL == ros3_reset_stats(file)) {
-        HGOTO_ERROR(H5E_INTERNAL, H5E_UNINITIALIZED, NULL, 
+        HGOTO_ERROR(H5E_INTERNAL, H5E_UNINITIALIZED, NULL,
                     "unable to reset file statistics")
     }
 #endif /* ROS3_STATS */
@@ -882,9 +888,9 @@ H5FD_ros3_open(const char *url,
 
 done:
     if (ret_value == NULL) {
-        if (handle != NULL) { 
+        if (handle != NULL) {
             if (FAIL == H5FD_s3comms_s3r_close(handle)) {
-                HDONE_ERROR(H5E_VFL, H5E_CANTCLOSEFILE, NULL, 
+                HDONE_ERROR(H5E_VFL, H5E_CANTCLOSEFILE, NULL,
                             "unable to close s3 file handle")
             }
         }
@@ -892,13 +898,28 @@ done:
             file = H5FL_FREE(H5FD_ros3_t, file);
         }
         curl_global_cleanup(); /* early cleanup because open failed */
-    } /* if null return value (error) */
-#endif /* H5_HAVE_ROS3_VFD */
+    } /* end if null return value (error) */
 
     FUNC_LEAVE_NOAPI(ret_value)
 
+} /* end H5FD_ros3_open() */
+
+#else /* H5_HAVE_ROS3_VFD not defined */
+
+static H5FD_t *
+H5FD_ros3_open(
+        const char H5_ATTR_UNUSED *url,
+        unsigned   H5_ATTR_UNUSED  flags,
+        hid_t      H5_ATTR_UNUSED  fapl_id,
+        haddr_t    H5_ATTR_UNUSED  maxaddr)
+{
+    H5FD_t *ret_value = NULL;
+    FUNC_ENTER_NOAPI_NOINIT_NOERR
+    FUNC_LEAVE_NOAPI(ret_value)
 } /* H5FD_ros3_open() */
 
+#endif /* H5_HAVE_ROS3_VFD */
+
 #if ROS3_STATS
 
 /*----------------------------------------------------------------------------
@@ -906,7 +927,7 @@ done:
  * Function: ros3_fprint_stats()
  *
  * Purpose:
- * 
+ *
  *     Tabulate and pretty-print statistics for this virtual file.
  *
  *     Should be called upon file close.
@@ -927,17 +948,17 @@ done:
  *         - max (largest size read)
  *     2. tabulation of "bins", sepraring reads into exponentially-larger
  *        ranges of size.
- *         - columns for number of reads, total bytes, and average size, with 
+ *         - columns for number of reads, total bytes, and average size, with
  *           separate sub-colums for raw- and metadata reads.
  *         - each row represents one bin, identified by the top of its range
- *     
+ *
  *     Bin ranges can be modified with pound-defines at the top of this file.
  *
  *     Bins without any reads in their bounds are not printed.
  *
  *     An "overflow" bin is also present, to catch "big" reads.
  *
- *     Output for all bins (and range ceiling and average size report) 
+ *     Output for all bins (and range ceiling and average size report)
  *     is divied by powers of 1024. By corollary, four digits before the decimal
  *     is valid.
  *
@@ -1050,7 +1071,7 @@ ros3_fprint_stats(FILE              *stream,
     HDfprintf(stream, "TOTAL BYTES: %llu  (%llu meta, %llu raw)\n",
               bytes_raw + bytes_meta, bytes_meta, bytes_raw);
 
-    if (count_raw + count_meta == 0) 
+    if (count_raw + count_meta == 0)
         goto done;
 
     /*************************
@@ -1109,9 +1130,9 @@ ros3_fprint_stats(FILE              *stream,
      * PRINT INDIVIDUAL BIN STATS *
      ******************************/
 
-    HDfprintf(stream, 
+    HDfprintf(stream,
         "BINS             # of reads      total bytes         average size\n");
-    HDfprintf(stream, 
+    HDfprintf(stream,
         "    up-to      meta     raw     meta      raw       meta      raw\n");
 
     for (i = 0; i <= ROS3_STATS_BIN_COUNT; i++) {
@@ -1129,7 +1150,7 @@ ros3_fprint_stats(FILE              *stream,
 
         m = &file->meta[i];
         r = &file->raw[i];
-        if (r->count == 0 && m->count == 0) 
+        if (r->count == 0 && m->count == 0)
             continue;
 
         range_end = ros3_stats_boundaries[i];
@@ -1172,7 +1193,7 @@ ros3_fprint_stats(FILE              *stream,
             re_dub /= 1024.0;
         HDassert(suffix_i < sizeof(suffixes));
 
-        HDfprintf(stream, 
+        HDfprintf(stream,
                   " %8.3f%c %7d %7d %8.3f%c %8.3f%c %8.3f%c %8.3f%c\n",
                   re_dub, suffixes[suffix_i], /* bin ceiling      */
                   m->count,                   /* metadata reads   */
@@ -1187,7 +1208,7 @@ ros3_fprint_stats(FILE              *stream,
 
 done:
     FUNC_LEAVE_NOAPI(ret_value);
-    
+
 } /* ros3_fprint_stats */
 #endif /* ROS3_STATS */
 
@@ -1201,7 +1222,7 @@ done:
  *     Close an HDF5 file.
  *
  * Return:
- * 
+ *
  *     SUCCEED/FAIL
  *
  * Programmer: Jacob Smith
@@ -1211,57 +1232,63 @@ done:
  *
  *-------------------------------------------------------------------------
  */
+#ifdef H5_HAVE_ROS3_VFD
+
 static herr_t
-H5FD_ros3_close(H5FD_t *_file)
+H5FD_ros3_close(H5FD_t H5_ATTR_UNUSED *_file)
 {
-#ifdef H5_HAVE_ROS3_VFD
     H5FD_ros3_t *file      = (H5FD_ros3_t *)_file;
     herr_t       ret_value = SUCCEED;
-#else
-    herr_t       ret_value = FAIL;
-#endif
-
-
 
     FUNC_ENTER_NOAPI_NOINIT
-#ifdef H5_HAVE_ROS3_VFD
 
 #if ROS3_DEBUG
     HDfprintf(stdout, "H5FD_ros3_close() called.\n");
 #endif
 
-    /* Sanity checks 
+    /* Sanity checks
      */
     HDassert(file != NULL);
     HDassert(file->s3r_handle != NULL);
 
-    /* Close the underlying request handle 
+    /* Close the underlying request handle
      */
     if (FAIL == H5FD_s3comms_s3r_close(file->s3r_handle)) {
-        HGOTO_ERROR(H5E_VFL, H5E_CANTCLOSEFILE, FAIL, 
+        HGOTO_ERROR(H5E_VFL, H5E_CANTCLOSEFILE, FAIL,
                     "unable to close S3 request handle")
     }
 
 #if ROS3_STATS
     /* TODO: mechanism to re-target stats printout */
-    if (FAIL == ros3_fprint_stats(stdout, file)) {
-        HGOTO_ERROR(H5E_INTERNAL, H5E_ERROR, FAIL, 
+    if (ros3_fprint_stats(stdout, file) == FAIL) {
+        HGOTO_ERROR(H5E_INTERNAL, H5E_ERROR, FAIL,
                     "problem while writing file statistics")
     }
 #endif /* ROS3_STATS */
 
-    /* Release the file info 
+    /* Release the file info
      */
     file = H5FL_FREE(H5FD_ros3_t, file);
 
 done:
     curl_global_cleanup(); /* cleanup to answer init on open */
-#endif /* H5_HAVE_ROS3_VFD */
 
     FUNC_LEAVE_NOAPI(ret_value)
 
 } /* end H5FD_ros3_close() */
 
+#else /* H5_HAVE_ROS3_VFD not defined */
+
+static herr_t
+H5FD_ros3_close(H5FD_t H5_ATTR_UNUSED *_file)
+{
+    herr_t ret_value = FAIL;
+    FUNC_ENTER_NOAPI_NOINIT_NOERR
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5FD_ros3_close() */
+
+#endif /* H5_HAVE_ROS3_VFD */
+
 
 /*-------------------------------------------------------------------------
  *
@@ -1269,7 +1296,7 @@ done:
  *
  * Purpose:
  *
- *     Compares two files belonging to this driver using an arbitrary 
+ *     Compares two files belonging to this driver using an arbitrary
  *     (but consistent) ordering:
  *
  *     + url scheme
@@ -1284,7 +1311,7 @@ done:
  *     tl;dr -> check URL, check crentials
  *
  * Return:
- *      
+ *
  *     - Equivalent:      0
  *     - Not Equivalent: -1
  *
@@ -1300,22 +1327,20 @@ done:
  *
  *-------------------------------------------------------------------------
  */
+#ifdef H5_HAVE_ROS3_VFD
+
 static int
-H5FD_ros3_cmp(const H5FD_t *_f1,
-              const H5FD_t *_f2)
+H5FD_ros3_cmp(
+        const H5FD_t *_f1,
+        const H5FD_t *_f2)
 {
-#ifdef H5_HAVE_ROS3_VFD
     const H5FD_ros3_t  *f1        = (const H5FD_ros3_t *)_f1;
     const H5FD_ros3_t  *f2        = (const H5FD_ros3_t *)_f2;
     const parsed_url_t *purl1     = NULL;
     const parsed_url_t *purl2     = NULL;
-#endif
     int                 ret_value = 0;
 
-
-
     FUNC_ENTER_NOAPI_NOINIT_NOERR
-#ifdef H5_HAVE_ROS3_VFD
 
 #if ROS3_DEBUG
     HDfprintf(stdout, "H5FD_ros3_cmp() called.\n");
@@ -1334,71 +1359,124 @@ H5FD_ros3_cmp(const H5FD_t *_f1,
     HDassert(purl2->host != NULL);
 
     /* URL: SCHEME */
-    if (HDstrcmp(purl1->scheme, purl2->scheme)) HGOTO_DONE(-1);
+    if (HDstrcmp(purl1->scheme, purl2->scheme)) {
+        HGOTO_DONE(-1);
+    }
 
     /* URL: HOST */
-    if (HDstrcmp(purl1->host, purl2->host)) HGOTO_DONE(-1);
+    if (HDstrcmp(purl1->host, purl2->host)) {
+        HGOTO_DONE(-1);
+    }
 
     /* URL: PORT */
     if (purl1->port && purl2->port) {
-        if (HDstrcmp(purl1->port, purl2->port)) HGOTO_DONE(-1);
-    } else if (purl1->port) {
+        if (HDstrcmp(purl1->port, purl2->port)) {
+            HGOTO_DONE(-1);
+        }
+    }
+    else
+    if (purl1->port) {
         HGOTO_DONE(-1);
-    } else if (purl2->port) {
+    }
+    else
+    if (purl2->port) {
         HGOTO_DONE(-1);
     }
 
     /* URL: PATH */
     if (purl1->path && purl2->path) {
-        if (HDstrcmp(purl1->path, purl2->path)) HGOTO_DONE(-1);
-    } else if (purl1->path && !purl2->path) {
+        if (HDstrcmp(purl1->path, purl2->path)) {
+            HGOTO_DONE(-1);
+        }
+    }
+    else
+    if (purl1->path && !purl2->path) {
         HGOTO_DONE(-1);
-    } else if (purl2->path && !purl1->path) {
+    }
+    else
+    if (purl2->path && !purl1->path) {
         HGOTO_DONE(-1);
     }
 
     /* URL: QUERY */
     if (purl1->query && purl2->query) {
-        if (HDstrcmp(purl1->query, purl2->query)) HGOTO_DONE(-1);
-    } else if (purl1->query && !purl2->query) {
+        if (HDstrcmp(purl1->query, purl2->query)) {
+            HGOTO_DONE(-1);
+        }
+    }
+    else
+    if (purl1->query && !purl2->query) {
         HGOTO_DONE(-1);
-    } else if (purl2->query && !purl1->query) {
+    }
+    else
+    if (purl2->query && !purl1->query) {
         HGOTO_DONE(-1);
     }
 
     /* FAPL: AWS_REGION */
     if (f1->fa.aws_region[0] != '\0' && f1->fa.aws_region[0] != '\0') {
-        if (HDstrcmp(f1->fa.aws_region, f2->fa.aws_region)) HGOTO_DONE(-1);
-    } else if (f1->fa.aws_region[0] != '\0') {
+        if (HDstrcmp(f1->fa.aws_region, f2->fa.aws_region)) {
+            HGOTO_DONE(-1);
+        }
+    }
+    else
+    if (f1->fa.aws_region[0] != '\0') {
         HGOTO_DONE(-1);
-    } else if (f2->fa.aws_region[0] != '\0') {
+    }
+    else
+    if (f2->fa.aws_region[0] != '\0') {
         HGOTO_DONE(-1);
     }
 
     /* FAPL: SECRET_ID */
     if (f1->fa.secret_id[0] != '\0' && f1->fa.secret_id[0] != '\0') {
-        if (HDstrcmp(f1->fa.secret_id, f2->fa.secret_id)) HGOTO_DONE(-1);
-    } else if (f1->fa.secret_id[0] != '\0') {
+        if (HDstrcmp(f1->fa.secret_id, f2->fa.secret_id)) {
+            HGOTO_DONE(-1);
+        }
+    }
+    else
+    if (f1->fa.secret_id[0] != '\0') {
         HGOTO_DONE(-1);
-    } else if (f2->fa.secret_id[0] != '\0') {
+    }
+    else
+    if (f2->fa.secret_id[0] != '\0') {
         HGOTO_DONE(-1);
     }
 
     /* FAPL: SECRET_KEY */
     if (f1->fa.secret_key[0] != '\0' && f1->fa.secret_key[0] != '\0') {
-        if (HDstrcmp(f1->fa.secret_key, f2->fa.secret_key)) HGOTO_DONE(-1);
-    } else if (f1->fa.secret_key[0] != '\0') {
+        if (HDstrcmp(f1->fa.secret_key, f2->fa.secret_key)) {
+            HGOTO_DONE(-1);
+        }
+    }
+    else
+    if (f1->fa.secret_key[0] != '\0') {
         HGOTO_DONE(-1);
-    } else if (f2->fa.secret_key[0] != '\0') {
+    }
+    else
+    if (f2->fa.secret_key[0] != '\0') {
         HGOTO_DONE(-1);
     }
-#endif /* H5_HAVE_ROS3_VFD */
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
 
 } /* H5FD_ros3_cmp() */
 
+#else /* H5_HAVE_ROS3_VFD not defined */
+
+static int
+H5FD_ros3_cmp(
+        const H5FD_t H5_ATTR_UNUSED *_f1,
+        const H5FD_t H5_ATTR_UNUSED *_f2)
+{
+    int                 ret_value = 0;
+    FUNC_ENTER_NOAPI_NOINIT_NOERR
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5FD_ros3_cmp() */
+
+#endif /* H5_HAVE_ROS3_VFD */
+
 
 /*-------------------------------------------------------------------------
  * Function:    H5FD_ros3_query
@@ -1406,7 +1484,7 @@ done:
  * Purpose:     Set the flags that this VFL driver is capable of supporting.
  *              (listed in H5FDpublic.h)
  *
- *              Note that since the ROS3 VFD is read only, most flags 
+ *              Note that since the ROS3 VFD is read only, most flags
  *              are irrelevant.
  *
  *              The term "set" is highly misleading...
@@ -1420,7 +1498,7 @@ done:
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5FD_ros3_query(const H5FD_t H5_ATTR_UNUSED *_file, 
+H5FD_ros3_query(const H5FD_t H5_ATTR_UNUSED *_file,
                 unsigned long *flags /* out */)
 {
     FUNC_ENTER_NOAPI_NOINIT_NOERR
@@ -1433,7 +1511,7 @@ H5FD_ros3_query(const H5FD_t H5_ATTR_UNUSED *_file,
     if (flags) {
         *flags = 0;
         /* OK to perform data sieving for faster raw data reads & writes */
-        *flags |= H5FD_FEAT_DATA_SIEVE; 
+        *flags |= H5FD_FEAT_DATA_SIEVE;
     } /* end if */
 
     FUNC_LEAVE_NOAPI(SUCCEED)
@@ -1463,7 +1541,7 @@ H5FD_ros3_query(const H5FD_t H5_ATTR_UNUSED *_file,
  *-------------------------------------------------------------------------
  */
 static haddr_t
-H5FD_ros3_get_eoa(const H5FD_t                *_file, 
+H5FD_ros3_get_eoa(const H5FD_t                *_file,
                   H5FD_mem_t   H5_ATTR_UNUSED  type)
 {
     const H5FD_ros3_t *file = (const H5FD_ros3_t *)_file;
@@ -1499,8 +1577,8 @@ H5FD_ros3_get_eoa(const H5FD_t                *_file,
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5FD_ros3_set_eoa(H5FD_t                    *_file, 
-                  H5FD_mem_t H5_ATTR_UNUSED  type, 
+H5FD_ros3_set_eoa(H5FD_t                    *_file,
+                  H5FD_mem_t H5_ATTR_UNUSED  type,
                   haddr_t                    addr)
 {
     H5FD_ros3_t *file = (H5FD_ros3_t *)_file;
@@ -1528,7 +1606,7 @@ H5FD_ros3_set_eoa(H5FD_t                    *_file,
  *
  * Return:
  *
- *     EOF: the first address past the end of the "file", either the 
+ *     EOF: the first address past the end of the "file", either the
  *     filesystem file or the HDF5 file.
  *
  * Programmer: Jacob Smith
@@ -1537,7 +1615,7 @@ H5FD_ros3_set_eoa(H5FD_t                    *_file,
  *-------------------------------------------------------------------------
  */
 static haddr_t
-H5FD_ros3_get_eof(const H5FD_t                *_file, 
+H5FD_ros3_get_eof(const H5FD_t                *_file,
                   H5FD_mem_t   H5_ATTR_UNUSED  type)
 {
     const H5FD_ros3_t *file = (const H5FD_ros3_t *)_file;
@@ -1573,8 +1651,8 @@ H5FD_ros3_get_eof(const H5FD_t                *_file,
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5FD_ros3_get_handle(H5FD_t                *_file, 
-                     hid_t H5_ATTR_UNUSED   fapl, 
+H5FD_ros3_get_handle(H5FD_t                *_file,
+                     hid_t H5_ATTR_UNUSED   fapl,
                      void                 **file_handle)
 {
     H5FD_ros3_t *file      = (H5FD_ros3_t *)_file;
@@ -1586,8 +1664,9 @@ H5FD_ros3_get_handle(H5FD_t                *_file,
     HDfprintf(stdout, "H5FD_ros3_get_handle() called.\n");
 #endif
 
-    if(!file_handle)
+    if (!file_handle) {
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "file handle not valid")
+    }
 
     *file_handle = file->s3r_handle;
 
@@ -1601,7 +1680,7 @@ done:
  *
  * Function: H5FD_ros3_read()
  *
- * Purpose: 
+ * Purpose
  *
  *     Reads SIZE bytes of data from FILE beginning at address ADDR
  *     into buffer BUF according to data transfer properties in DXPL_ID.
@@ -1622,8 +1701,8 @@ done:
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5FD_ros3_read(H5FD_t                    *_file, 
-               H5FD_mem_t H5_ATTR_UNUSED  type, 
+H5FD_ros3_read(H5FD_t                    *_file,
+               H5FD_mem_t H5_ATTR_UNUSED  type,
                hid_t      H5_ATTR_UNUSED  dxpl_id,
                haddr_t                    addr, /* start offset   */
                size_t                     size, /* length of read */
@@ -1631,13 +1710,13 @@ H5FD_ros3_read(H5FD_t                    *_file,
 {
     H5FD_ros3_t *file      = (H5FD_ros3_t *)_file;
     size_t       filesize  = 0;
-    herr_t       ret_value = SUCCEED;                  /* Return value */
+    herr_t       ret_value = SUCCEED;
 #if ROS3_STATS
     /* working variables for storing stats */
     ros3_statsbin *bin   = NULL;
     unsigned       bin_i = 0;
 #endif /* ROS3_STATS */
-    
+
 
     FUNC_ENTER_NOAPI_NOINIT
 
@@ -1655,7 +1734,7 @@ H5FD_ros3_read(H5FD_t                    *_file,
         HGOTO_ERROR(H5E_ARGS, H5E_OVERFLOW, FAIL, "range exceeds file address")
     }
 
-    if (FAIL == H5FD_s3comms_s3r_read(file->s3r_handle, addr, size, buf) ) {
+    if (H5FD_s3comms_s3r_read(file->s3r_handle, addr, size, buf) == FAIL) {
         HGOTO_ERROR(H5E_VFL, H5E_READERROR, FAIL, "unable to execute read")
     }
 
@@ -1664,30 +1743,33 @@ H5FD_ros3_read(H5FD_t                    *_file,
     /* Find which "bin" this read fits in. Can be "overflow" bin.
      */
     for (bin_i = 0; bin_i < ROS3_STATS_BIN_COUNT; bin_i++) {
-        if ((unsigned long long)size < ros3_stats_boundaries[bin_i])
+        if ((unsigned long long)size < ros3_stats_boundaries[bin_i]) {
             break;
+        }
     }
     bin = (type == H5FD_MEM_DRAW)
         ? &file->raw[bin_i]
         : &file->meta[bin_i];
 
-    /* Store collected stats in appropriate bin 
+    /* Store collected stats in appropriate bin
      */
     if (bin->count == 0) {
         bin->min = size;
         bin->max = size;
-    } else {
-        if (size < bin->min) 
+    }
+    else {
+        if (size < bin->min) {
             bin->min = size;
-        if (size > bin->max)
+        }
+        if (size > bin->max) {
             bin->max = size;
+        }
     }
     bin->count++;
     bin->bytes += (unsigned long long)size;
 
 #endif /* ROS3_STATS */
 
-
 done:
     FUNC_LEAVE_NOAPI(ret_value)
 
@@ -1698,12 +1780,12 @@ done:
  *
  * Function: H5FD_ros3_write()
  *
- * Purpose: 
+ * Purpose:
  *
  *     Write bytes to file.
  *     UNSUPPORTED IN READ-ONLY ROS3 VFD.
  *
- * Return: 
+ * Return:
  *
  *     FAIL (Not possible with Read-Only S3 file.)
  *
@@ -1715,11 +1797,11 @@ done:
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5FD_ros3_write(H5FD_t     H5_ATTR_UNUSED *_file, 
-                H5FD_mem_t H5_ATTR_UNUSED  type, 
+H5FD_ros3_write(H5FD_t     H5_ATTR_UNUSED *_file,
+                H5FD_mem_t H5_ATTR_UNUSED  type,
                 hid_t      H5_ATTR_UNUSED  dxpl_id,
-                haddr_t    H5_ATTR_UNUSED  addr, 
-                size_t     H5_ATTR_UNUSED  size, 
+                haddr_t    H5_ATTR_UNUSED  addr,
+                size_t     H5_ATTR_UNUSED  size,
                 const void H5_ATTR_UNUSED *buf)
 {
     herr_t ret_value = FAIL;
@@ -1762,8 +1844,8 @@ done:
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5FD_ros3_truncate(H5FD_t  H5_ATTR_UNUSED *_file, 
-                   hid_t   H5_ATTR_UNUSED  dxpl_id, 
+H5FD_ros3_truncate(H5FD_t  H5_ATTR_UNUSED *_file,
+                   hid_t   H5_ATTR_UNUSED  dxpl_id,
                    hbool_t H5_ATTR_UNUSED  closing)
 {
     herr_t ret_value = SUCCEED;
@@ -1807,7 +1889,7 @@ done:
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5FD_ros3_lock(H5FD_t  H5_ATTR_UNUSED *_file, 
+H5FD_ros3_lock(H5FD_t  H5_ATTR_UNUSED *_file,
                hbool_t H5_ATTR_UNUSED  rw)
 {
     FUNC_ENTER_NOAPI_NOINIT_NOERR
diff --git a/src/H5FDs3comms.c b/src/H5FDs3comms.c
index 8c0515d..42b281f 100644
--- a/src/H5FDs3comms.c
+++ b/src/H5FDs3comms.c
@@ -11,7 +11,7 @@
  * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
 /*****************************************************************************
- * Read-Only S3 Virtual File Driver (VFD)                                   
+ * Read-Only S3 Virtual File Driver (VFD)
  *
  * Source for S3 Communications module
  *
@@ -51,6 +51,8 @@
  */
 #define S3COMMS_DEBUG 0
 
+#ifdef H5_HAVE_ROS3_VFD
+
 /* manipulate verbosity of CURL output
  * operates separately from S3COMMS_DEBUG
  *
@@ -65,6 +67,8 @@
  */
 #define S3COMMS_MAX_RANGE_STRING_SIZE 128
 
+#endif /* H5_HAVE_ROS3_VFD */
+
 /******************/
 /* Local Typedefs */
 /******************/
@@ -111,7 +115,7 @@ herr_t H5FD_s3comms_s3r_getsize(s3r_t *handle);
 /* Functions */
 /*************/
 
-
+
 /*----------------------------------------------------------------------------
  *
  * Function: curlwritecallback()
@@ -147,8 +151,9 @@ curlwritecallback(char   *ptr,
     size_t                 product = (size * nmemb);
     size_t                 written = 0;
 
-    if (sds->magic != S3COMMS_CALLBACK_DATASTRUCT_MAGIC)
+    if (sds->magic != S3COMMS_CALLBACK_DATASTRUCT_MAGIC) {
         return written;
+    }
 
     if (size > 0) {
         HDmemcpy(&(sds->data[sds->size]), ptr, product);
@@ -158,9 +163,9 @@ curlwritecallback(char   *ptr,
 
     return written;
 
-} /* curlwritecallback */
-
+} /* end curlwritecallback() */
 
+
 /*----------------------------------------------------------------------------
  *
  * Function: H5FD_s3comms_hrb_node_set()
@@ -223,9 +228,10 @@ curlwritecallback(char   *ptr,
  *----------------------------------------------------------------------------
  */
 herr_t
-H5FD_s3comms_hrb_node_set(hrb_node_t **L,
-                          const char  *name,
-                          const char  *value)
+H5FD_s3comms_hrb_node_set(
+        hrb_node_t **L,
+        const char  *name,
+        const char  *value)
 {
     size_t      i          = 0;
     char       *valuecpy   = NULL;
@@ -238,8 +244,6 @@ H5FD_s3comms_hrb_node_set(hrb_node_t **L,
     hbool_t     is_looking = TRUE;
     herr_t      ret_value  = SUCCEED;
 
-
-
     FUNC_ENTER_NOAPI_NOINIT
 
 #if S3COMMS_DEBUG
@@ -247,8 +251,9 @@ H5FD_s3comms_hrb_node_set(hrb_node_t **L,
     HDprintf("NAME: %s\n", name);
     HDprintf("VALUE: %s\n", value);
     HDprintf("LIST:\n->");
-    for (node_ptr = (*L); node_ptr != NULL; node_ptr = node_ptr->next)
+    for (node_ptr = (*L); node_ptr != NULL; node_ptr = node_ptr->next) {
         HDfprintf(stdout, "{%s}\n->", node_ptr->cat);
+    }
     HDprintf("(null)\n");
     fflush(stdout);
     node_ptr = NULL;
@@ -281,34 +286,37 @@ H5FD_s3comms_hrb_node_set(hrb_node_t **L,
      * copies
      */
     if (value != NULL) {
-        size_t valuelen   = HDstrlen(value);
-        size_t catlen     = namelen + valuelen + 2; /* HDstrlen(": ") -> +2 */
-        int    sprint_ret = 0;
+        int    ret      = 0;
+        size_t valuelen = HDstrlen(value);
+        size_t catlen   = namelen + valuelen + 2; /* +2 from ": " */
+        size_t catwrite = catlen + 3; /* 3 not 1 to quiet compiler warning */
+
 
         namecpy = (char *)H5MM_malloc(sizeof(char) * (namelen + 1));
         if (namecpy == NULL) {
             HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL,
                         "cannot make space for name copy.\n");
         }
-        HDmemcpy(namecpy, name, namelen + 1);
+        HDmemcpy(namecpy, name, (namelen + 1));
 
         valuecpy = (char *)H5MM_malloc(sizeof(char) * (valuelen + 1));
         if (valuecpy == NULL) {
             HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL,
                         "cannot make space for value copy.\n");
         }
-        HDmemcpy(valuecpy, value, valuelen + 1);
+        HDmemcpy(valuecpy, value, (valuelen + 1));
 
-        nvcat = (char *)H5MM_malloc(sizeof(char) * (catlen + 1));
+        nvcat = (char *)H5MM_malloc(sizeof(char) * catwrite);
         if (nvcat == NULL) {
             HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL,
                         "cannot make space for concatenated string.\n");
         }
-        sprint_ret = HDsnprintf(nvcat, (catlen + 1), "%s: %s", name, value);
-        if (sprint_ret <= 0)
+        ret = HDsnprintf(nvcat, catwrite, "%s: %s", name, value);
+        if (ret < 0 || (size_t)ret > catlen) {
             HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL,
-                        "error while concatenating `%s: %s", name, value);
-        HDassert( catlen == (size_t)sprint_ret );
+                        "cannot concatenate `%s: %s", name, value);
+        }
+        HDassert( catlen == HDstrlen(nvcat) );
 
         /* create new_node, should we need it
          */
@@ -334,7 +342,8 @@ H5FD_s3comms_hrb_node_set(hrb_node_t **L,
         if (value == NULL) {
             HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL,
                         "trying to remove node from empty list");
-        } else {
+        }
+        else {
 #if S3COMMS_DEBUG
 HDprintf("CREATE NEW\n"); fflush(stdout);
 #endif
@@ -406,7 +415,8 @@ HDprintf("FREEING POINTER\n"); fflush(stdout);
 HDprintf("FREEING WORKING LOWERNAME\n"); fflush(stdout);
 #endif
             H5MM_xfree(lowername); lowername = NULL;
-        } else {
+        }
+        else {
 #if S3COMMS_DEBUG
 HDprintf("MODIFY HEAD\n"); fflush(stdout);
 #endif
@@ -428,14 +438,17 @@ HDprintf("MODIFY HEAD\n"); fflush(stdout);
             H5MM_xfree(new_node);
             new_node  = NULL;
         }
-    } else if (strcmp(lowername, node_ptr->lowername) < 0) {
+    }
+    else
+    if (strcmp(lowername, node_ptr->lowername) < 0) {
 
         is_looking = FALSE;
 
         if (value == NULL) {
             HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL,
                         "trying to remove a node 'before' head");
-        } else {
+        }
+        else {
 #if S3COMMS_DEBUG
 HDprintf("PREPEND NEW HEAD\n"); fflush(stdout);
 #endif
@@ -464,7 +477,8 @@ HDprintf("PREPEND NEW HEAD\n"); fflush(stdout);
             if (value == NULL) {
                 HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL,
                             "trying to remove absent node");
-            } else {
+            }
+            else {
 #if S3COMMS_DEBUG
 HDprintf("APPEND A NODE\n"); fflush(stdout);
 #endif
@@ -479,14 +493,17 @@ HDprintf("APPEND A NODE\n"); fflush(stdout);
                 new_node->cat       = nvcat;
                 node_ptr->next      = new_node;
             }
-        } else if (strcmp(lowername, node_ptr->next->lowername) < 0) {
+        }
+        else
+        if (strcmp(lowername, node_ptr->next->lowername) < 0) {
 
             is_looking = FALSE;
 
             if (value == NULL) {
                 HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL,
                             "trying to remove absent node");
-            } else {
+            }
+            else {
 #if S3COMMS_DEBUG
 HDprintf("INSERT A NODE\n"); fflush(stdout);
 #endif
@@ -502,7 +519,9 @@ HDprintf("INSERT A NODE\n"); fflush(stdout);
                 new_node->next      = node_ptr->next;
                 node_ptr->next      = new_node;
             }
-        } else if (strcmp(lowername, node_ptr->next->lowername) == 0) {
+        }
+        else
+        if (strcmp(lowername, node_ptr->next->lowername) == 0) {
 
             is_looking = FALSE;
 
@@ -528,7 +547,8 @@ HDprintf("REMOVE A NODE\n"); fflush(stdout);
 
                 H5MM_xfree(lowername);
                 lowername = NULL;
-            } else {
+            }
+            else {
 #if S3COMMS_DEBUG
 HDprintf("MODIFY A NODE\n"); fflush(stdout);
 #endif
@@ -552,23 +572,24 @@ HDprintf("MODIFY A NODE\n"); fflush(stdout);
                 node_ptr->value = valuecpy;
                 node_ptr->cat   = nvcat;
             }
-        } else {
+        }
+        else {
             /****************
              * KEEP LOOKING *
              ****************/
 
              node_ptr = node_ptr->next;
         }
-    }
+    } /* end while is_looking */
 
 done:
     if (ret_value == FAIL) {
         /* clean up
          */
-        if (nvcat     != NULL) H5MM_xfree(nvcat);
-        if (namecpy   != NULL) H5MM_xfree(namecpy);
-        if (lowername != NULL) H5MM_xfree(lowername);
-        if (valuecpy  != NULL) H5MM_xfree(valuecpy);
+        if (nvcat     != NULL) { H5MM_xfree(nvcat); }
+        if (namecpy   != NULL) { H5MM_xfree(namecpy); }
+        if (lowername != NULL) { H5MM_xfree(lowername); }
+        if (valuecpy  != NULL) { H5MM_xfree(valuecpy); }
         if (new_node  != NULL) {
             HDassert( new_node->magic == S3COMMS_HRB_NODE_MAGIC );
             new_node->magic += 1ul;
@@ -577,11 +598,9 @@ done:
     }
 
     FUNC_LEAVE_NOAPI(ret_value);
+} /* end H5FD_s3comms_hrb_node_set() */
 
-} /* H5FD_s3comms_hrb_node_set */
-
-
-
+
 /*----------------------------------------------------------------------------
  *
  * Function: H5FD_s3comms_hrb_destroy()
@@ -637,8 +656,6 @@ H5FD_s3comms_hrb_destroy(hrb_t **_buf)
     hrb_t  *buf       = NULL;
     herr_t  ret_value = SUCCEED;
 
-
-
     FUNC_ENTER_NOAPI_NOINIT
 
 #if S3COMMS_DEBUG
@@ -658,12 +675,11 @@ H5FD_s3comms_hrb_destroy(hrb_t **_buf)
         buf->magic += 1ul;
         H5MM_xfree(buf);
         *_buf = NULL;
-    }
+    } /* end if `_buf` has some value */
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
-
-} /* H5FD_s3comms_hrb_destroy */
+} /* end H5FD_s3comms_hrb_destroy() */
 
 
 /*----------------------------------------------------------------------------
@@ -728,8 +744,6 @@ H5FD_s3comms_hrb_init_request(const char *_verb,
     char   *vrsn      = NULL;
     size_t  vrsnlen   = 0;
 
-
-
     FUNC_ENTER_NOAPI_NOINIT
 
 #if S3COMMS_DEBUG
@@ -743,11 +757,13 @@ H5FD_s3comms_hrb_init_request(const char *_verb,
 
     /* populate valid NULLs with defaults
      */
-    if (_verb == NULL)
+    if (_verb == NULL) {
         _verb = "GET";
+    }
 
-    if (_http_version == NULL)
+    if (_http_version == NULL) {
         _http_version = "HTTP/1.1";
+    }
 
     /* malloc space for and prepare structure
      */
@@ -765,28 +781,26 @@ H5FD_s3comms_hrb_init_request(const char *_verb,
 
     /* malloc and copy strings for the structure
      */
+    reslen = HDstrlen(_resource);
+
     if (_resource[0] == '/') {
-        reslen = HDstrlen(_resource) + 1;
-        res = (char *)H5MM_malloc(sizeof(char) * reslen);
+        res = (char *)H5MM_malloc(sizeof(char) * (reslen+1));
         if (res == NULL) {
             HGOTO_ERROR(H5E_ARGS, H5E_CANTALLOC, NULL,
                         "no space for resource string");
         }
-        HDstrncpy(res, _resource, reslen);
-    } else {
-        int sprint_ret = 0;
-        reslen = HDstrlen(_resource) + 2;
-        res = (char *)H5MM_malloc(sizeof(char) * reslen);
+        HDmemcpy(res, _resource, (reslen+1));
+    }
+    else {
+        res = (char *)H5MM_malloc(sizeof(char) * (reslen+2));
         if (res == NULL) {
             HGOTO_ERROR(H5E_ARGS, H5E_CANTALLOC, NULL,
-                        "no space for resource string");
+                    "no space for resource string");
         }
-        sprint_ret = HDsnprintf(res, reslen, "/%s", _resource);
-        if (sprint_ret <= 0)
-            HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, NULL,
-                        "errro while appending resource string %s", _resource);
-        HDassert( (reslen - 1) == (size_t)sprint_ret );
-    } /* start resource string with '/' */
+        *res = '/';
+        HDmemcpy((&res[1]), _resource, (reslen+1));
+        HDassert( (reslen+1) == HDstrlen(res) );
+    } /* end if (else resource string not starting with '/') */
 
     verblen = HDstrlen(_verb) + 1;
     verb = (char *)H5MM_malloc(sizeof(char) * verblen);
@@ -815,7 +829,6 @@ H5FD_s3comms_hrb_init_request(const char *_verb,
     ret_value = request;
 
 done:
-
     /* if there is an error, clean up after ourselves
      */
     if (ret_value == NULL) {
@@ -826,8 +839,7 @@ done:
     }
 
     FUNC_LEAVE_NOAPI(ret_value)
-
-} /* H5FD_s3comms_hrb_init_request */
+} /* end H5FD_s3comms_hrb_init_request() */
 
 
 
@@ -835,7 +847,60 @@ done:
  * S3R FUNCTIONS
  ****************************************************************************/
 
+#ifndef H5_HAVE_ROS3_VFD
+/* No-op, auto-fail, unused-variable implementations if ROS3 is not enabled */
+
+herr_t
+H5FD_s3comms_s3r_close(s3r_t H5_ATTR_UNUSED *handle)
+{
+    herr_t ret_value = SUCCEED;
+    FUNC_ENTER_NOAPI_NOINIT_NOERR
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5FD_s3comms_s3r_close() */
+
+size_t
+H5FD_s3comms_s3r_get_filesize(s3r_t H5_ATTR_UNUSED *handle)
+{
+    size_t ret_value = 0;
+    FUNC_ENTER_NOAPI_NOINIT_NOERR
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5FD_s3comms_s3r_get_filesize() */
+
+herr_t
+H5FD_s3comms_s3r_getsize(s3r_t H5_ATTR_UNUSED *handle)
+{
+    herr_t ret_value = FAIL;
+    FUNC_ENTER_NOAPI_NOINIT_NOERR
+    FUNC_LEAVE_NOAPI(ret_value);
+} /* end H5FD_s3comms_s3r_getsize() */
+
+s3r_t *
+H5FD_s3comms_s3r_open(
+        const char          H5_ATTR_UNUSED *url,
+        const char          H5_ATTR_UNUSED *region,
+        const char          H5_ATTR_UNUSED *id,
+        const unsigned char H5_ATTR_UNUSED *signing_key)
+{
+    s3r_t        *ret_value = NULL;
+    FUNC_ENTER_NOAPI_NOINIT_NOERR
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5FD_s3comms_s3r_open() */
 
+herr_t
+H5FD_s3comms_s3r_read(
+        s3r_t   H5_ATTR_UNUSED *handle,
+        haddr_t H5_ATTR_UNUSED  offset,
+        size_t  H5_ATTR_UNUSED  len,
+        void    H5_ATTR_UNUSED *dest)
+{
+    herr_t ret_value = FAIL;
+    FUNC_ENTER_NOAPI_NOINIT_NOERR
+    FUNC_LEAVE_NOAPI(ret_value);
+} /* end H5FD_s3comms_s3r_read() */
+
+#else
+
+
 /*----------------------------------------------------------------------------
  *
  * Function: H5FD_s3comms_s3r_close()
@@ -876,11 +941,8 @@ H5FD_s3comms_s3r_close(s3r_t *handle)
 {
     herr_t ret_value = SUCCEED;
 
-
-
     FUNC_ENTER_NOAPI_NOINIT
 
-#ifdef H5_HAVE_ROS3_VFD
 #if S3COMMS_DEBUG
     HDfprintf(stdout, "called H5FD_s3comms_s3r_close.\n");
 #endif
@@ -910,14 +972,11 @@ H5FD_s3comms_s3r_close(s3r_t *handle)
 
     H5MM_xfree(handle);
 
-#endif /* H5_HAVE_ROS3_VFD */
-
 done:
     FUNC_LEAVE_NOAPI(ret_value)
-
 } /* H5FD_s3comms_s3r_close */
 
-
+
 /*----------------------------------------------------------------------------
  *
  * Function: H5FD_s3comms_s3r_get_filesize()
@@ -941,22 +1000,20 @@ done:
  *----------------------------------------------------------------------------
  */
 size_t
-H5FD_s3comms_s3r_get_filesize(s3r_t *handle) {
-
+H5FD_s3comms_s3r_get_filesize(s3r_t *handle)
+{
     size_t ret_value = 0;
 
     FUNC_ENTER_NOAPI_NOINIT_NOERR
 
-#ifdef H5_HAVE_ROS3_VFD
-    if (handle != NULL)
+    if (handle != NULL) {
         ret_value = handle->filesize;
-#endif /* H5_HAVE_ROS3_VFD */
+    }
 
     FUNC_LEAVE_NOAPI(ret_value)
-
 } /* H5FD_s3comms_s3r_get_filesize */
 
-
+
 /*----------------------------------------------------------------------------
  *
  * Function: H5FD_s3comms_s3r_getsize()
@@ -1143,7 +1200,7 @@ H5FD_s3comms_s3r_getsize(s3r_t *handle)
         HGOTO_ERROR(H5E_ARGS, H5E_OVERFLOW, FAIL, "content_length overflows size_t\n");
     }
 
-    if (content_length == 0 ||    
+    if (content_length == 0 ||
         errno          == ERANGE) /* errno set by strtoumax*/
     {
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL,
@@ -1187,7 +1244,7 @@ done:
 
 } /* H5FD_s3comms_s3r_getsize */
 
-
+
 /*----------------------------------------------------------------------------
  *
  * Function: H5FD_s3comms_s3r_open()
@@ -1463,7 +1520,7 @@ done:
 
 } /* H5FD_s3comms_s3r_open */
 
-
+
 /*----------------------------------------------------------------------------
  *
  * Function: H5FD_s3comms_s3r_read()
@@ -1621,7 +1678,7 @@ H5FD_s3comms_s3r_read(s3r_t   *handle,
 
     if (len > 0) {
         rangebytesstr = (char *)H5MM_malloc(sizeof(char) * \
-                                            S3COMMS_MAX_RANGE_STRING_SIZE );
+                                            (S3COMMS_MAX_RANGE_STRING_SIZE+1) );
         if (rangebytesstr == NULL) {
             HGOTO_ERROR(H5E_ARGS, H5E_CANTALLOC, FAIL,
                         "could not malloc range format string.\n");
@@ -1631,12 +1688,12 @@ H5FD_s3comms_s3r_read(s3r_t   *handle,
                        "bytes="H5_PRINTF_HADDR_FMT"-"H5_PRINTF_HADDR_FMT,
                        offset,
                        offset + len - 1);
-        if (ret == 0 || ret >= S3COMMS_MAX_RANGE_STRING_SIZE)
+        if (ret <= 0 || ret >= S3COMMS_MAX_RANGE_STRING_SIZE)
             HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL,
                         "unable to format HTTP Range value");
     } else if (offset > 0) {
         rangebytesstr = (char *)H5MM_malloc(sizeof(char) * \
-                                            S3COMMS_MAX_RANGE_STRING_SIZE);
+                                            (S3COMMS_MAX_RANGE_STRING_SIZE+1));
         if (rangebytesstr == NULL) {
             HGOTO_ERROR(H5E_ARGS, H5E_CANTALLOC, FAIL,
                         "could not malloc range format string.\n");
@@ -1645,7 +1702,7 @@ H5FD_s3comms_s3r_read(s3r_t   *handle,
                        (S3COMMS_MAX_RANGE_STRING_SIZE),
                       "bytes="H5_PRINTF_HADDR_FMT"-",
                       offset);
-        if (ret == 0 || ret >= S3COMMS_MAX_RANGE_STRING_SIZE)
+        if (ret <= 0 || ret >= S3COMMS_MAX_RANGE_STRING_SIZE)
             HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL,
                         "unable to format HTTP Range value");
     }
@@ -1679,7 +1736,7 @@ H5FD_s3comms_s3r_read(s3r_t   *handle,
     } else {
         /* authenticate request
          */
-        char authorization[512];
+        char authorization[512+1];
             /*   512 := approximate max length...
              *    67 <len("AWS4-HMAC-SHA256 Credential=///s3/aws4_request,"
              *           "SignedHeaders=,Signature=")>
@@ -1689,10 +1746,10 @@ H5FD_s3comms_s3r_read(s3r_t   *handle,
              * +  20 <max? len(region)>
              * + 128 <max? len(signed_headers)>
              */
-        char buffer1[512]; /* -> Canonical Request -> Signature */
-        char buffer2[256]; /* -> String To Sign -> Credential */
+        char buffer1[512+1]; /* -> Canonical Request -> Signature */
+        char buffer2[256+1]; /* -> String To Sign -> Credential */
         char iso8601now[ISO8601_SIZE];
-        char signed_headers[48];
+        char signed_headers[48+1];
             /* should be large enough for nominal listing:
              * "host;range;x-amz-content-sha256;x-amz-date"
              * + '\0', with "range;" possibly absent
@@ -1821,8 +1878,11 @@ H5FD_s3comms_s3r_read(s3r_t   *handle,
         /**** COMPUTE AUTHORIZATION ****/
 
         if (FAIL ==      /* buffer1 -> canonical request */
-            H5FD_s3comms_aws_canonical_request(buffer1,
+            H5FD_s3comms_aws_canonical_request(
+                    buffer1,
+                    512,
                     signed_headers,
+                    48,
                     request) )
         {
             HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL,
@@ -1858,23 +1918,25 @@ H5FD_s3comms_s3r_read(s3r_t   *handle,
             HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL,
                         "unable to format aws4 credential string");
 
-        ret = HDsnprintf(authorization,
+        ret = HDsnprintf(
+                authorization,
                 512,
                 "AWS4-HMAC-SHA256 Credential=%s,SignedHeaders=%s,Signature=%s",
                 buffer2,
                 signed_headers,
                 buffer1);
-        if (ret == 0 || ret >= 512)
+        if (ret <= 0 || ret >= 512) {
             HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL,
                         "unable to format aws4 authorization string");
+        }
 
         /* append authorization header to http request buffer
          */
-        if (FAIL ==
-            H5FD_s3comms_hrb_node_set(
-                    &headers,
-                    "Authorization",
-                    (const char *)authorization) )
+        if (H5FD_s3comms_hrb_node_set(
+                &headers,
+                "Authorization",
+                (const char *)authorization)
+            == FAIL)
         {
             HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL,
                         "unable to set Authorization header")
@@ -1914,17 +1976,18 @@ H5FD_s3comms_s3r_read(s3r_t   *handle,
 
         /* finally, set http headers in curl handle
          */
-        if (CURLE_OK !=
-            curl_easy_setopt(curlh,
-                             CURLOPT_HTTPHEADER,
-                             curlheaders) )
+        if (curl_easy_setopt(
+                curlh,
+                CURLOPT_HTTPHEADER,
+                curlheaders)
+           != CURLE_OK)
         {
             HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL,
                         "error while setting CURL option "
                         "(CURLOPT_HTTPHEADER). (placeholder flags)");
         }
 
-    } /* if should authenticate (info provided) */
+    } /* end if should authenticate (info provided) */
 
     /*******************
      * PERFORM REQUEST *
@@ -1983,14 +2046,16 @@ H5FD_s3comms_s3r_read(s3r_t   *handle,
         HDfprintf(stderr, "CHECKING FOR BUFFER OVERFLOW\n");
         if (sds == NULL) {
             HDfprintf(stderr, "sds is NULL!\n");
-        } else {
+        }
+        else {
             HDfprintf(stderr, "sds: 0x%lx\n", (long long)sds);
             HDfprintf(stderr, "sds->size: %d\n", (int)sds->size);
             if (len > sds->size) {
                 HDfprintf(stderr, "buffer overwrite\n");
             }
         }
-    } else {
+    }
+    else {
         HDfprintf(stderr, "performed on entire file\n");
     }
 #endif
@@ -2028,29 +2093,30 @@ done:
 
     if (curlh != NULL) {
         /* clear any Range */
-        if (CURLE_OK != curl_easy_setopt(curlh, CURLOPT_RANGE, NULL) )
+        if (CURLE_OK != curl_easy_setopt(curlh, CURLOPT_RANGE, NULL) ) {
                 HDONE_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL,
                             "cannot unset CURLOPT_RANGE")
+        }
 
         /* clear headers */
-        if (CURLE_OK != curl_easy_setopt(curlh, CURLOPT_HTTPHEADER, NULL) )
+        if (CURLE_OK != curl_easy_setopt(curlh, CURLOPT_HTTPHEADER, NULL) ) {
                 HDONE_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL,
                             "cannot unset CURLOPT_HTTPHEADER")
+        }
     }
 
 #endif /* H5_HAVE_ROS3_VFD */
 
     FUNC_LEAVE_NOAPI(ret_value);
-
 } /* H5FD_s3comms_s3r_read */
 
-
+#endif /* H5_HAVE_ROS3_VFD */
 
 /****************************************************************************
  * MISCELLANEOUS FUNCTIONS
  ****************************************************************************/
 
-
+
 /*----------------------------------------------------------------------------
  *
  * Function: gmnow()
@@ -2079,14 +2145,14 @@ gmnow(void)
     struct tm *ret_value = NULL;
 
     /* Doctor assert, checks against error in time() */
-    if ( (time_t)(-1) != time(now_ptr) )
+    if ( (time_t)(-1) != time(now_ptr) ) {
         ret_value = gmtime(now_ptr);
+    }
 
     HDassert( ret_value != NULL );
 
     return ret_value;
-
-} /* gmnow */
+} /* end gmnow() */
 
 
 /*----------------------------------------------------------------------------
@@ -2131,16 +2197,23 @@ gmnow(void)
  *----------------------------------------------------------------------------
  */
 herr_t
-H5FD_s3comms_aws_canonical_request(char  *canonical_request_dest,
-                                   char  *signed_headers_dest,
-                                   hrb_t *http_request)
+H5FD_s3comms_aws_canonical_request(
+        char  *canonical_request_dest,
+        int    _cr_size,
+        char  *signed_headers_dest,
+        int    _sh_size,
+        hrb_t *http_request)
 {
     hrb_node_t *node         = NULL;
     const char *query_params = ""; /* unused at present */
     herr_t      ret_value    = SUCCEED;
-    int         ret          = 0; /* return value of HDsnprintf */
-    size_t      len          = 0; /* working string length variable */
-    char        tmpstr[256];
+    int         ret          = 0;
+    size_t      cr_size      = (size_t)_cr_size;
+    size_t      sh_size      = (size_t)_sh_size;
+    size_t      cr_len       = 0; /* working length of canonical request str */
+    size_t      sh_len       = 0; /* working length of signed headers str */
+    char        tmpstr[256+1];
+    tmpstr[256]              = 0; /* terminating NULL */
 
     /* "query params" refers to the optional element in the URL, e.g.
      *     http://bucket.aws.com/myfile.txt?max-keys=2&prefix=J
@@ -2152,8 +2225,6 @@ H5FD_s3comms_aws_canonical_request(char  *canonical_request_dest,
      * VFD use-cases.
      */
 
-
-
     FUNC_ENTER_NOAPI_NOINIT
 
 #if S3COMMS_DEBUG
@@ -2178,55 +2249,71 @@ H5FD_s3comms_aws_canonical_request(char  *canonical_request_dest,
 
     /* HTTP verb, resource path, and query string lines
      */
-    len = (HDstrlen(http_request->verb) +
+    cr_len = (HDstrlen(http_request->verb) +
           HDstrlen(http_request->resource) +
           HDstrlen(query_params) +
-          3 );
-    ret = HDsnprintf(canonical_request_dest,
-                   len + 1,
-                   "%s\n%s\n%s\n",
-                   http_request->verb,
-                   http_request->resource,
-                   query_params);
-    if (ret == 0 || (size_t)ret > len)
+          (size_t)3); /* three newline chars */
+    if (cr_len >= cr_size) {
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL,
+                    "not enough space in canonical request");
+    }
+    ret = HDsnprintf( /* TODO: compiler warning */
+            canonical_request_dest,
+            (cr_size-1),
+            "%s\n%s\n%s\n",
+            http_request->verb,
+            http_request->resource,
+            query_params);
+    if (ret < 0 || (size_t)ret >= cr_size) {
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL,
                     "unable to compose canonical request first line");
+    }
 
     /* write in canonical headers, building signed headers concurrently
      */
-    node = http_request->first_header; /* assumed at first sorted */
+    node = http_request->first_header; /* assumed sorted */
     while (node != NULL) {
-        size_t join_len  = 0; /* string len of joined header-value */
-
-        HDassert( node->magic == S3COMMS_HRB_NODE_MAGIC );
-
-        len = HDstrlen(node->lowername);
-        join_len = HDstrlen(node->value) + len + 2; /* +2 <- ":\n" */
-        ret = HDsnprintf(tmpstr,
-                       join_len + 1, /* +1 for null terminator */
-                       "%s:%s\n",
-                       node->lowername,
-                       node->value);
-        if (ret == 0 || (size_t)ret > join_len)
+
+        HDassert(node->magic == S3COMMS_HRB_NODE_MAGIC);
+
+        ret = HDsnprintf(
+                tmpstr,
+                256,
+                "%s:%s\n",
+                node->lowername,
+                node->value);
+        if (ret < 0 || ret >= 256) {
             HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL,
                         "unable to concatenate HTTP header %s:%s",
                          node->lowername,
                          node->value);
+        }
+        cr_len += HDstrlen(tmpstr);
+        if (cr_len + 1 > cr_size) {
+            HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL,
+                        "not enough space in canonical request");
+        }
         strcat(canonical_request_dest, tmpstr);
 
-        len += 1; /* semicolon */
-        ret = HDsnprintf(tmpstr,
-                       len + 1,
-                       "%s;",
-                       node->lowername);
-        if (ret == 0 || (size_t)ret > len)
+        ret = HDsnprintf(
+                tmpstr,
+                256,
+                "%s;",
+                node->lowername);
+        if (ret < 0 || ret >= 256) {
             HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL,
-                        "unable to append signed header %s",
+                        "unable to append semicolon to lowername %s",
                         node->lowername);
+        }
+        sh_len += HDstrlen(tmpstr);
+        if (sh_len + 1 > sh_size) {
+            HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL,
+                        "not enough space in signed headers");
+        }
         strcat(signed_headers_dest, tmpstr);
 
         node = node->next;
-    }
+    } /* end while node is not NULL */
 
     /* remove tailing ';' from signed headers sequence
      */
@@ -2243,10 +2330,9 @@ H5FD_s3comms_aws_canonical_request(char  *canonical_request_dest,
 
 done:
     FUNC_LEAVE_NOAPI(ret_value);
+} /* end H5FD_s3comms_aws_canonical_request() */
 
-} /* H5FD_s3comms_aws_canonical_request */
-
-
+
 /*----------------------------------------------------------------------------
  *
  * Function: H5FD_s3comms_bytes_to_hex()
@@ -2293,16 +2379,15 @@ done:
  *----------------------------------------------------------------------------
  */
 herr_t
-H5FD_s3comms_bytes_to_hex(char                *dest,
-                          const unsigned char *msg,
-                          size_t               msg_len,
-                          hbool_t              lowercase)
+H5FD_s3comms_bytes_to_hex(
+        char                *dest,
+        const unsigned char *msg,
+        size_t               msg_len,
+        hbool_t              lowercase)
 {
     size_t i         = 0;
     herr_t ret_value = SUCCEED;
 
-
-
     FUNC_ENTER_NOAPI_NOINIT
 
 #if S3COMMS_DEBUG
@@ -2319,24 +2404,23 @@ H5FD_s3comms_bytes_to_hex(char                *dest,
     }
 
     for (i = 0; i < msg_len; i++) {
-        int chars_written =
-                HDsnprintf(&(dest[i * 2]),
-                         3, /* 'X', 'X', '\n' */
-                         (lowercase == TRUE) ? "%02x"
-                                             : "%02X",
-                         msg[i]);
-        if (chars_written != 2)
+        int chars_written = HDsnprintf(&(dest[i * 2]),
+                3, /* 'X', 'X', '\n' */
+                (lowercase == TRUE) ? "%02x" : "%02X",
+                msg[i]);
+        if (chars_written != 2) {
             HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL,
                         "problem while writing hex chars for %c",
                         msg[i]);
+        }
     }
 
 done:
     FUNC_LEAVE_NOAPI(ret_value);
 
-} /* H5FD_s3comms_bytes_to_hex */
-
+} /* end H5FD_s3comms_bytes_to_hex() */
 
+
 /*----------------------------------------------------------------------------
  *
  * Function: H5FD_s3comms_free_purl()
@@ -2369,19 +2453,19 @@ H5FD_s3comms_free_purl(parsed_url_t *purl)
 
     if (purl != NULL) {
         HDassert( purl->magic == S3COMMS_PARSED_URL_MAGIC );
-        if (purl->scheme != NULL) H5MM_xfree(purl->scheme);
-        if (purl->host   != NULL) H5MM_xfree(purl->host);
-        if (purl->port   != NULL) H5MM_xfree(purl->port);
-        if (purl->path   != NULL) H5MM_xfree(purl->path);
-        if (purl->query  != NULL) H5MM_xfree(purl->query);
+        if (purl->scheme != NULL) { H5MM_xfree(purl->scheme); }
+        if (purl->host   != NULL) { H5MM_xfree(purl->host); }
+        if (purl->port   != NULL) { H5MM_xfree(purl->port); }
+        if (purl->path   != NULL) { H5MM_xfree(purl->path); }
+        if (purl->query  != NULL) { H5MM_xfree(purl->query); }
         purl->magic += 1ul;
         H5MM_xfree(purl);
     }
 
     FUNC_LEAVE_NOAPI(SUCCEED)
-} /* H5FD_s3comms_free_purl */
-
+} /* end H5FD_s3comms_free_purl() */
 
+
 /*----------------------------------------------------------------------------
  *
  * Function: H5FD_s3comms_HMAC_SHA256()
@@ -2424,27 +2508,22 @@ H5FD_s3comms_free_purl(parsed_url_t *purl)
  *
  *----------------------------------------------------------------------------
  */
+#ifdef H5_HAVE_ROS3_VFD
+
 herr_t
-H5FD_s3comms_HMAC_SHA256(const unsigned char *key,
-                         size_t               key_len,
-                         const char          *msg,
-                         size_t               msg_len,
-                         char                *dest)
+H5FD_s3comms_HMAC_SHA256(
+        const unsigned char *key,
+        size_t               key_len,
+        const char          *msg,
+        size_t               msg_len,
+        char                *dest)
 {
-#ifdef H5_HAVE_ROS3_VFD
     unsigned char md[SHA256_DIGEST_LENGTH];
     unsigned int  md_len    = SHA256_DIGEST_LENGTH;
     herr_t        ret_value = SUCCEED;
-#else
-    herr_t        ret_value = FAIL;
-#endif /* H5_HAVE_ROS3_VFD */
-
-
 
     FUNC_ENTER_NOAPI_NOINIT
 
-#ifdef H5_HAVE_ROS3_VFD
-
 #if S3COMMS_DEBUG
     HDfprintf(stdout, "called H5FD_s3comms_HMAC_SHA256.\n");
 #endif
@@ -2462,24 +2541,39 @@ H5FD_s3comms_HMAC_SHA256(const unsigned char *key,
          md,
          &md_len);
 
-    if (FAIL ==
-        H5FD_s3comms_bytes_to_hex(dest,
-                                  (const unsigned char *)md,
-                                  (size_t)md_len,
-                                  true))
+    if (H5FD_s3comms_bytes_to_hex(
+            dest,
+            (const unsigned char *)md,
+            (size_t)md_len,
+            true)
+        == FAIL)
     {
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL,
                     "could not convert to hex string.");
     }
 
-#endif /* H5_HAVE_ROS3_VFD */
-
 done:
     FUNC_LEAVE_NOAPI(ret_value);
-
 } /* H5FD_s3comms_HMAC_SHA256 */
 
+#else /* H5_HAVE_ROS3_VFD not defined */
+
+herr_t
+H5FD_s3comms_HMAC_SHA256(
+        const unsigned char H5_ATTR_UNUSED *key,
+        size_t              H5_ATTR_UNUSED  key_len,
+        const char          H5_ATTR_UNUSED *msg,
+        size_t              H5_ATTR_UNUSED  msg_len,
+        char                H5_ATTR_UNUSED *dest)
+{
+    herr_t ret_value = FAIL;
+    FUNC_ENTER_NOAPI_NOINIT_NOERR
+    FUNC_LEAVE_NOAPI(ret_value);
+} /* end H5FD_s3comms_HMAC_SHA256() */
+
+#endif /* H5_HAVE_ROS3_VFD */
 
+
 /*-----------------------------------------------------------------------------
  *
  * Function: H5FD__s3comms_load_aws_creds_from_file()
@@ -2565,85 +2659,98 @@ H5FD__s3comms_load_aws_creds_from_file(
 #endif
 
     /* format target line for start of profile */
-    if (32 < HDsnprintf(profile_line, 32, "[%s]", profile_name))
+    if (32 < HDsnprintf(profile_line, 32, "[%s]", profile_name)) {
         HGOTO_ERROR(H5E_ARGS, H5E_CANTCOPY, FAIL,
                     "unable to format profile label")
+    }
 
     /* look for start of profile */
     do {
         /* clear buffer */
-        for (buffer_i=0; buffer_i < 128; buffer_i++) buffer[buffer_i] = 0;
+        for (buffer_i=0; buffer_i < 128; buffer_i++) {
+            buffer[buffer_i] = 0;
+        }
 
         line_buffer = fgets(line_buffer, 128, file);
-        if (line_buffer == NULL) /* reached end of file */
+        if (line_buffer == NULL) { /* reached end of file */
             goto done;
+        }
     } while (strncmp(line_buffer, profile_line, HDstrlen(profile_line)));
 
     /* extract credentials from lines */
     do {
-        size_t      setting_name_len = 0;
-        const char *setting_name     = NULL;
-        char        line_prefix[128];
-
         /* clear buffer */
-        for (buffer_i=0; buffer_i < 128; buffer_i++) buffer[buffer_i] = 0;
+        for (buffer_i=0; buffer_i < 128; buffer_i++) {
+             buffer[buffer_i] = 0;
+        }
 
         /* collect a line from file */
         line_buffer = fgets(line_buffer, 128, file);
-        if (line_buffer == NULL)
+        if (line_buffer == NULL) {
             goto done; /* end of file */
+        }
 
         /* loop over names to see if line looks like assignment */
         for (setting_i = 0; setting_i < setting_count; setting_i++) {
+            size_t      setting_name_len = 0;
+            const char *setting_name     = NULL;
+            char        line_prefix[128];
+
             setting_name = setting_names[setting_i];
             setting_name_len = HDstrlen(setting_name);
-            if (128 < HDsnprintf(
-                    line_prefix,
-                    setting_name_len+2,
-                    "%s=",
-                    setting_name))
+            if (HDsnprintf(line_prefix, 128, "%s=", setting_name) < 0) {
                 HGOTO_ERROR(H5E_ARGS, H5E_CANTCOPY, FAIL,
                             "unable to format line prefix")
+            }
 
             /* found a matching name? */
             if (!HDstrncmp(line_buffer, line_prefix, setting_name_len + 1)) {
                 found_setting = 1;
 
                 /* skip NULL destination buffer */
-                if (setting_pointers[setting_i] == NULL)
+                if (setting_pointers[setting_i] == NULL) {
                    break;
+                }
 
                 /* advance to end of name in string */
                 do {
                     line_buffer++;
                 } while (*line_buffer != 0 && *line_buffer != '=');
 
-                if (*line_buffer == 0 || *(line_buffer+1) == 0)
+                if (*line_buffer == 0 || *(line_buffer+1) == 0) {
                     HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL,
                                 "incomplete assignment in file")
+                }
                 line_buffer++; /* was pointing at '='; advance */
 
                 /* copy line buffer into out pointer */
-                HDstrncpy(setting_pointers[setting_i], (const char *)line_buffer,
-                        HDstrlen(line_buffer));
+                if (HDstrncpy(
+                        setting_pointers[setting_i],
+                        (const char *)line_buffer,
+                        HDstrlen(line_buffer))
+                    == NULL)
+                {
+                    HGOTO_ERROR(H5E_ARGS, H5E_CANTCOPY, FAIL,
+                                "unable to copy line into pointer")
+                }
 
                 /* "trim" tailing whitespace by replacing with null terminator*/
                 buffer_i = 0;
-                while (!isspace(setting_pointers[setting_i][buffer_i]))
+                while (!isspace(setting_pointers[setting_i][buffer_i])) {
                     buffer_i++;
+                }
                 setting_pointers[setting_i][buffer_i] = '\0';
 
                 break; /* have read setting; don't compare with others */
-            }
-        }
+            } /* end if possible name match */
+        } /* end for each setting name */
     } while (found_setting);
 
 done:
     FUNC_LEAVE_NOAPI(ret_value);
+} /* end H5FD__s3comms_load_aws_creds_from_file() */
 
-} /* H5FD__s3comms_load_aws_creds_from_file */
-
-
+
 /*----------------------------------------------------------------------------
  *
  * Function: H5FD_s3comms_load_aws_profile()
@@ -2688,6 +2795,7 @@ H5FD_s3comms_load_aws_profile(const char *profile_name,
     FILE *credfile = NULL;
     char awspath[117];
     char filepath[128];
+    int  ret = 0;
 
     FUNC_ENTER_NOAPI_NOINIT
 
@@ -2696,47 +2804,61 @@ H5FD_s3comms_load_aws_profile(const char *profile_name,
 #endif
 
     /* TODO: Windows and other path gotchas */
-    if (117 < HDsnprintf(awspath, 117, "%s/.aws/", getenv("HOME")))
+    ret = HDsnprintf(awspath, 117, "%s/.aws/", getenv("HOME")) ;
+    if (ret < 0 || (size_t)ret >= 117) {
         HGOTO_ERROR(H5E_ARGS, H5E_CANTCOPY, FAIL,
                     "unable to format home-aws path")
-    if (128 < HDsnprintf(filepath, 128, "%s%s", awspath, "credentials"))
+    }
+    ret = HDsnprintf(filepath, 128, "%s%s", awspath, "credentials");
+    if (ret < 0 || (size_t)ret >= 128) {
         HGOTO_ERROR(H5E_ARGS, H5E_CANTCOPY, FAIL,
                     "unable to format credentials path")
+    }
 
     credfile = fopen(filepath, "r");
     if (credfile != NULL) {
-        if (FAIL == H5FD__s3comms_load_aws_creds_from_file(
+        if (H5FD__s3comms_load_aws_creds_from_file(
                 credfile,
                 profile_name,
                 key_id_out,
                 secret_access_key_out,
-                aws_region_out))
+                aws_region_out)
+            == FAIL)
+        {
             HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL,
                         "unable to load from aws credentials")
-        if (EOF == fclose(credfile))
+        }
+        if (fclose(credfile) == EOF) {
             HGOTO_ERROR(H5E_FILE, H5E_CANTCLOSEFILE, FAIL,
                         "unable to close credentials file")
+        }
         credfile = NULL;
-    }
+    } /* end if credential file opened */
 
-    if (128 < HDsnprintf(filepath, 128, "%s%s", awspath, "config"))
+    ret = HDsnprintf(filepath, 128, "%s%s", awspath, "config");
+    if (ret < 0 || (size_t)ret >= 128) {
         HGOTO_ERROR(H5E_ARGS, H5E_CANTCOPY, FAIL,
                     "unable to format config path")
+    }
     credfile = fopen(filepath, "r");
     if (credfile != NULL) {
-        if (FAIL == H5FD__s3comms_load_aws_creds_from_file(
+        if (H5FD__s3comms_load_aws_creds_from_file(
                 credfile,
                 profile_name,
                 (*key_id_out == 0) ? key_id_out : NULL,
                 (*secret_access_key_out == 0) ? secret_access_key_out : NULL,
-                (*aws_region_out == 0) ? aws_region_out : NULL))
+                (*aws_region_out == 0) ? aws_region_out : NULL)
+            == FAIL)
+        {
             HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL,
                         "unable to load from aws config")
-        if (EOF == fclose(credfile))
+        }
+        if (fclose(credfile) == EOF) {
             HGOTO_ERROR(H5E_FILE, H5E_CANTCLOSEFILE, FAIL,
                         "unable to close config file")
+        }
         credfile = NULL;
-    }
+    } /* end if credential file opened */
 
     /* fail if not all three settings were loaded */
     if (*key_id_out == 0 ||
@@ -2748,16 +2870,15 @@ H5FD_s3comms_load_aws_profile(const char *profile_name,
 
 done:
     if (credfile != NULL) {
-        if (EOF == fclose(credfile))
+        if (fclose(credfile) == EOF) {
             HDONE_ERROR(H5E_ARGS, H5E_ARGS, FAIL,
                         "problem error-closing aws configuration file")
+        }
     }
-
     FUNC_LEAVE_NOAPI(ret_value);
+} /* end H5FD_s3comms_load_aws_profile() */
 
-} /* H5FD_s3comms_load_aws_profile */
-
-
+
 /*----------------------------------------------------------------------------
  *
  * Function: H5FD_s3comms_nlowercase()
@@ -2787,9 +2908,10 @@ done:
  *----------------------------------------------------------------------------
  */
 herr_t
-H5FD_s3comms_nlowercase(char       *dest,
-                        const char *s,
-                        size_t      len)
+H5FD_s3comms_nlowercase(
+        char       *dest,
+        const char *s,
+        size_t      len)
 {
     herr_t ret_value = SUCCEED;
 
@@ -2814,10 +2936,9 @@ H5FD_s3comms_nlowercase(char       *dest,
 
 done:
     FUNC_LEAVE_NOAPI(ret_value);
+} /* end H5FD_s3comms_nlowercase() */
 
-} /* H5FD_s3comms_nlowercase */
-
-
+
 /*----------------------------------------------------------------------------
  *
  * Function: H5FD_s3comms_parse_url()
@@ -2852,8 +2973,9 @@ done:
  *----------------------------------------------------------------------------
  */
 herr_t
-H5FD_s3comms_parse_url(const char    *str,
-                       parsed_url_t **_purl)
+H5FD_s3comms_parse_url(
+        const char    *str,
+        parsed_url_t **_purl)
 {
     parsed_url_t *purl         = NULL; /* pointer to new structure */
     const char   *tmpstr       = NULL; /* working pointer in string */
@@ -2863,8 +2985,6 @@ H5FD_s3comms_parse_url(const char    *str,
     unsigned int  i            = 0;
     herr_t        ret_value    = FAIL;
 
-
-
     FUNC_ENTER_NOAPI_NOINIT;
 
 #if S3COMMS_DEBUG
@@ -2946,7 +3066,8 @@ H5FD_s3comms_parse_url(const char    *str,
             tmpstr++;
         }
         tmpstr++;
-    } else {
+    } /* end if (IPv6) */
+    else {
         while (0 != *tmpstr) {
             if (':' == *tmpstr ||
                 '/' == *tmpstr ||
@@ -2956,12 +3077,14 @@ H5FD_s3comms_parse_url(const char    *str,
             }
             tmpstr++;
         }
-    } /* if IPv4 or IPv6 */
+    } /* end else (IPv4) */
     len = tmpstr - curstr;
     if (len == 0) {
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL,
                     "HOST substring cannot be empty");
-    } else if (len > urllen) {
+    }
+    else
+    if (len > urllen) {
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL,
                     "problem with length of HOST substring");
     }
@@ -2990,7 +3113,9 @@ H5FD_s3comms_parse_url(const char    *str,
         if (len == 0) {
             HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL,
                         "PORT element cannot be empty");
-        } else if (len > urllen) {
+        }
+        else
+        if (len > urllen) {
             HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL,
                         "problem with length of PORT substring");
         }
@@ -3005,12 +3130,12 @@ H5FD_s3comms_parse_url(const char    *str,
          */
         purl->port = (char *)H5MM_malloc(sizeof(char) * (size_t)(len + 1));
         if (purl->port == NULL) { /* cannot malloc */
-                HGOTO_ERROR(H5E_ARGS, H5E_CANTALLOC, FAIL,
-                            "can't allocate space for PORT");
+            HGOTO_ERROR(H5E_ARGS, H5E_CANTALLOC, FAIL,
+                        "can't allocate space for PORT");
         }
         (void)HDstrncpy(purl->port, curstr, (size_t)len);
         purl->port[len] = 0;
-    } /* if PORT element */
+    } /* end if PORT element */
 
     /*************
      * READ PATH *
@@ -3040,7 +3165,7 @@ H5FD_s3comms_parse_url(const char    *str,
             (void)HDstrncpy(purl->path, curstr, (size_t)len);
             purl->path[len] = 0;
         }
-    } /* if PATH element */
+    } /* end if PATH element */
 
     /**************
      * READ QUERY *
@@ -3067,9 +3192,7 @@ H5FD_s3comms_parse_url(const char    *str,
         } /* cannot malloc path pointer */
         (void)HDstrncpy(purl->query, curstr, (size_t)len);
         purl->query[len] = 0;
-    } /* if QUERY exists */
-
-
+    } /* end if QUERY exists */
 
     *_purl = purl;
     ret_value =  SUCCEED;
@@ -3079,10 +3202,9 @@ done:
         H5FD_s3comms_free_purl(purl);
     }
     FUNC_LEAVE_NOAPI(ret_value);
+} /* end H5FD_s3comms_parse_url() */
 
-} /* H5FD_s3comms_parse_url */
-
-
+
 /*----------------------------------------------------------------------------
  *
  * Function: H5FD_s3comms_percent_encode_char()
@@ -3129,15 +3251,12 @@ done:
  *----------------------------------------------------------------------------
  */
 herr_t
-H5FD_s3comms_percent_encode_char(char                *repr,
-                                 const unsigned char  c,
-                                 size_t              *repr_len)
+H5FD_s3comms_percent_encode_char(
+        char                *repr,
+        const unsigned char  c,
+        size_t              *repr_len)
 {
-    unsigned int        acc           = 0;
     unsigned int        i             = 0;
-    unsigned int        k             = 0;
-    unsigned int        stack[4]      = {0, 0, 0, 0};
-    unsigned int        stack_size    = 0;
     int                 chars_written = 0;
     herr_t              ret_value     = SUCCEED;
 #if S3COMMS_DEBUG
@@ -3145,8 +3264,6 @@ H5FD_s3comms_percent_encode_char(char                *repr,
     unsigned char       hex[3]        = {0, 0, 0};
 #endif
 
-
-
     FUNC_ENTER_NOAPI_NOINIT
 
 #if S3COMMS_DEBUG
@@ -3172,13 +3289,19 @@ H5FD_s3comms_percent_encode_char(char                *repr,
 #endif
         *repr_len = 3;
         chars_written = HDsnprintf(repr, 4, "%%%02X", c);
-        if (chars_written != 3)
+        if (chars_written < 0) {
             HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL,
                         "cannot write char %c",
                         c);
-    } else {
+        }
+    } /* end if single-byte unicode char */
+    else {
         /* multi-byte, multi-percent representation
          */
+        unsigned int acc        = 0; /* byte accumulator */
+        unsigned int k          = 0; /* uint character representation */
+        unsigned int stack_size = 0;
+        unsigned char stack[4]  = {0, 0, 0, 0};
 #if S3COMMS_DEBUG
         HDfprintf(stdout, "    MULTI-BYTE\n");
 #endif
@@ -3191,21 +3314,22 @@ H5FD_s3comms_percent_encode_char(char                *repr,
             acc = k;
             acc >>= 6; /* cull least */
             acc <<= 6; /* six bits   */
-            stack[stack_size++] = k - acc; /* max six-bit number */
+            stack[stack_size++] = (unsigned char)(k - acc);
             k = acc >> 6;
         } while (k > 0);
 
-        /* now have "stack" of two to four six-bit numbers
-         * to be put into UTF-8 byte fields
+        /* `stack` now has two to four six-bit 'numbers' to be put into
+         * UTF-8 byte fields.
          */
 
 #if S3COMMS_DEBUG
         HDfprintf(stdout, "    STACK:\n    {\n");
         for (i = 0; i < stack_size; i++) {
-            H5FD_s3comms_bytes_to_hex((char *)hex,
-                                      (unsigned char *)(&stack[i]),
-                                      1,
-                                      FALSE);
+            H5FD_s3comms_bytes_to_hex(
+                    (char *)hex,
+                    (&stack[i]),
+                    1,
+                    FALSE);
             hex[2] = 0;
             HDfprintf(stdout, "      %s,\n", hex);
         }
@@ -3218,15 +3342,20 @@ H5FD_s3comms_percent_encode_char(char                *repr,
 
         /* prepend 11[1[1]]0 to first byte */
         /* 110xxxxx, 1110xxxx, or 11110xxx */
-        acc = 0xC0; /* 2^7 + 2^6 -> 11000000 */
-        acc += (stack_size > 2) ? 0x20 : 0;
-        acc += (stack_size > 3) ? 0x10 : 0;
-        stack_size -= 1;
-        chars_written = HDsnprintf(repr, 4, "%%%02X", acc + stack[stack_size]);
-        if (chars_written != 3)
+        acc = 0xC0;                         /* 0x11000000 */
+        acc += (stack_size > 2) ? 0x20 : 0; /* 0x00100000 */
+        acc += (stack_size > 3) ? 0x10 : 0; /* 0x00010000 */
+        stack_size--;
+        chars_written = HDsnprintf(
+                repr,
+                4,
+                "%%%02X",
+                (unsigned char)(acc + stack[stack_size]));
+        if (chars_written < 0) {
             HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL,
                         "cannot write char %c",
                         c);
+        }
         *repr_len += 3;
 
         /************************
@@ -3235,25 +3364,27 @@ H5FD_s3comms_percent_encode_char(char                *repr,
 
         /* 10xxxxxx */
         for (i = 0; i < stack_size; i++) {
-            chars_written = HDsnprintf(&repr[i*3 + 3],
-                                     4,
-                                     "%%%02X",
-                                     128 + stack[stack_size - 1 - i]);
-            if (chars_written != 3)
+            chars_written = HDsnprintf(
+                    &repr[i*3 + 3],
+                    4,
+                    "%%%02X",
+                    (unsigned char)(0x80 + stack[stack_size - 1 - i]));
+            if (chars_written < 0) {
                 HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL,
                             "cannot write char %c",
                             c);
+            }
             *repr_len += 3;
-        }
-    }
+        } /* end for each continuation byte */
+    } /* end else (multi-byte) */
+
     *(repr + *repr_len) = '\0';
 
 done:
     FUNC_LEAVE_NOAPI(ret_value);
-
 } /* H5FD_s3comms_percent_encode_char */
 
-
+
 /*----------------------------------------------------------------------------
  *
  * Function: H5FD_s3comms_signing_key()
@@ -3301,13 +3432,15 @@ done:
  *
  *----------------------------------------------------------------------------
  */
+#ifdef H5_HAVE_ROS3_VFD
+
 herr_t
-H5FD_s3comms_signing_key(unsigned char *md,
-                         const char    *secret,
-                         const char    *region,
-                         const char    *iso8601now)
+H5FD_s3comms_signing_key(
+        unsigned char *md,
+        const char    *secret,
+        const char    *region,
+        const char    *iso8601now)
 {
-#ifdef H5_HAVE_ROS3_VFD
     char          *AWS4_secret     = NULL;
     size_t         AWS4_secret_len = 0;
     unsigned char  datekey[SHA256_DIGEST_LENGTH];
@@ -3315,16 +3448,9 @@ H5FD_s3comms_signing_key(unsigned char *md,
     unsigned char  dateregionservicekey[SHA256_DIGEST_LENGTH];
     int            ret             = 0; /* return value of HDsnprintf */
     herr_t         ret_value       = SUCCEED;
-#else
-    herr_t         ret_value       = SUCCEED;
-#endif /* H5_HAVE_ROS3_VFD */
-
-
 
     FUNC_ENTER_NOAPI_NOINIT
 
-#ifdef H5_HAVE_ROS3_VFD
-
 #if S3COMMS_DEBUG
     HDfprintf(stdout, "called H5FD_s3comms_signing_key.\n");
 #endif
@@ -3356,10 +3482,11 @@ H5FD_s3comms_signing_key(unsigned char *md,
     /* prepend "AWS4" to start of the secret key
      */
     ret = HDsnprintf(AWS4_secret, AWS4_secret_len,"%s%s", "AWS4", secret);
-    if ((size_t)ret != (AWS4_secret_len - 1))
+    if ((size_t)ret != (AWS4_secret_len - 1)) {
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL,
                     "problem writing AWS4+secret `%s`",
                     secret);
+    }
 
     /* hash_func, key, len(key), msg, len(msg), digest_dest, digest_len_dest
      * we know digest length, so ignore via NULL
@@ -3396,13 +3523,26 @@ H5FD_s3comms_signing_key(unsigned char *md,
 done:
     H5MM_xfree(AWS4_secret);
 
-#endif /* H5_HAVE_ROS3_VFD */
-
     FUNC_LEAVE_NOAPI(ret_value);
+} /* end H5FD_s3comms_signing_key() */
+
+#else /* H5_HAVE_ROS3_VFD not defined */
 
-} /* H5FD_s3comms_signing_key */
+herr_t
+H5FD_s3comms_signing_key(
+        unsigned char H5_ATTR_UNUSED *md,
+        const char    H5_ATTR_UNUSED *secret,
+        const char    H5_ATTR_UNUSED *region,
+        const char    H5_ATTR_UNUSED *iso8601now)
+{
+    herr_t ret_value = SUCCEED;
+    FUNC_ENTER_NOAPI_NOINIT_NOERR;
+    FUNC_LEAVE_NOAPI(ret_value);
+} /* end H5FD_s3comms_signing_key() */
 
+#endif /* H5_HAVE_ROS3_VFD */
 
+
 /*----------------------------------------------------------------------------
  *
  * Function: H5FD_s3comms_tostringtosign()
@@ -3450,13 +3590,14 @@ done:
  *
  *----------------------------------------------------------------------------
  */
+#ifdef H5_HAVE_ROS3_VFD
 herr_t
-H5FD_s3comms_tostringtosign(char       *dest,
-                            const char *req,
-                            const char *now,
-                            const char *region)
+H5FD_s3comms_tostringtosign(
+        char       *dest,
+        const char *req,
+        const char *now,
+        const char *region)
 {
-#ifdef H5_HAVE_ROS3_VFD
     unsigned char checksum[SHA256_DIGEST_LENGTH * 2 + 1];
     size_t        d         = 0;
     char          day[9];
@@ -3465,15 +3606,9 @@ H5FD_s3comms_tostringtosign(char       *dest,
     int           ret       = 0; /* HDsnprintf return value */
     herr_t        ret_value = SUCCEED;
     char          tmp[128];
-#else
-    herr_t        ret_value = FAIL;
-#endif /* H5_HAVE_ROS3_VFD */
-
 
     FUNC_ENTER_NOAPI_NOINIT
 
-#ifdef H5_HAVE_ROS3_VFD
-
 #if S3COMMS_DEBUG
     HDfprintf(stdout, "called H5FD_s3comms_tostringtosign.\n");
 #endif
@@ -3495,8 +3630,6 @@ H5FD_s3comms_tostringtosign(char       *dest,
                     "Region cannot be NULL.\n")
     }
 
-
-
     for (i = 0; i < 128; i++) {
         tmp[i] = '\0';
     }
@@ -3507,11 +3640,10 @@ H5FD_s3comms_tostringtosign(char       *dest,
     HDstrncpy(day, now, 8);
     day[8] = '\0';
     ret = HDsnprintf(tmp, 127, "%s/%s/s3/aws4_request", day, region);
-    if (ret <= 0 || ret >= 127)
+    if (ret <= 0 || ret >= 127) {
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL,
                     "problem adding day and region to string")
-
-
+    }
 
     HDmemcpy((dest + d), "AWS4-HMAC-SHA256\n", 17);
     d = 17;
@@ -3528,11 +3660,12 @@ H5FD_s3comms_tostringtosign(char       *dest,
            HDstrlen(req),
            checksum);
 
-    if (FAIL ==
-        H5FD_s3comms_bytes_to_hex(hexsum,
-                                  (const unsigned char *)checksum,
-                                  SHA256_DIGEST_LENGTH,
-                                  true))
+    if (H5FD_s3comms_bytes_to_hex(
+            hexsum,
+            (const unsigned char *)checksum,
+            SHA256_DIGEST_LENGTH,
+            true)
+        == FAIL)
     {
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL,
                     "could not create hex string");
@@ -3544,14 +3677,27 @@ H5FD_s3comms_tostringtosign(char       *dest,
 
     dest[d] = '\0';
 
-#endif /* H5_HAVE_ROS3_VFD */
-
 done:
     FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5ros3_tostringtosign() */
+
+#else /* H5_HAVE_ROS3_VFD not defined */
 
-} /* H5ros3_tostringtosign */
+herr_t
+H5FD_s3comms_tostringtosign(
+        char       H5_ATTR_UNUSED *dest,
+        const char H5_ATTR_UNUSED *req,
+        const char H5_ATTR_UNUSED *now,
+        const char H5_ATTR_UNUSED *region)
+{
+    herr_t        ret_value = FAIL;
+    FUNC_ENTER_NOAPI_NOINIT_NOERR
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5ros3_tostringtosign() */
 
+#endif /* H5_HAVE_ROS3_VFD */
 
+
 /*----------------------------------------------------------------------------
  *
  * Function: H5FD_s3comms_trim()
@@ -3594,9 +3740,7 @@ H5FD_s3comms_trim(char   *dest,
                   size_t  s_len,
                   size_t *n_written)
 {
-    herr_t               ret_value = SUCCEED;
-
-
+    herr_t ret_value = SUCCEED;
 
     FUNC_ENTER_NOAPI_NOINIT
 
@@ -3612,8 +3756,6 @@ H5FD_s3comms_trim(char   *dest,
         s_len = 0;
     }
 
-
-
     if (s_len > 0) {
         /* Find first non-whitespace character from start;
          * reduce total length per character.
@@ -3645,10 +3787,9 @@ H5FD_s3comms_trim(char   *dest,
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5FD_s3comms_trim() */
 
-} /* H5FD_s3comms_trim */
-
-
+
 /*----------------------------------------------------------------------------
  *
  * Function: H5FD_s3comms_uriencode()
@@ -3698,11 +3839,12 @@ done:
  *----------------------------------------------------------------------------
  */
 herr_t
-H5FD_s3comms_uriencode(char       *dest,
-                       const char *s,
-                       size_t      s_len,
-                       hbool_t     encode_slash,
-                       size_t     *n_written)
+H5FD_s3comms_uriencode(
+        char       *dest,
+        const char *s,
+        size_t      s_len,
+        hbool_t     encode_slash,
+        size_t     *n_written)
 {
     char   c         = 0;
     size_t dest_off  = 0;
@@ -3712,20 +3854,20 @@ H5FD_s3comms_uriencode(char       *dest,
     herr_t ret_value = SUCCEED;
     size_t s_off     = 0;
 
-
-
     FUNC_ENTER_NOAPI_NOINIT
 
 #if S3COMMS_DEBUG
     HDfprintf(stdout, "H5FD_s3comms_uriencode called.\n");
 #endif
 
-    if (s == NULL)
+    if (s == NULL) {
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL,
                     "source string cannot be NULL");
-    if (dest == NULL)
+    }
+    if (dest == NULL) {
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL,
                     "destination cannot be NULL");
+    }
 
     /* Write characters to destination, converting to percent-encoded
      * "hex-utf-8" strings if necessary.
@@ -3741,12 +3883,14 @@ H5FD_s3comms_uriencode(char       *dest,
             (c == '/' && encode_slash == FALSE))
         {
             dest[dest_off++] = c;
-        } else {
+        }
+        else {
             hex_off = 0;
-            if (FAIL ==
-                H5FD_s3comms_percent_encode_char(hex_buffer,
-                                                 (const unsigned char)c,
-                                                 &hex_len))
+            if (H5FD_s3comms_percent_encode_char(
+                    hex_buffer,
+                    (const unsigned char)c,
+                    &hex_len)
+                == FAIL)
             {
                 hex_buffer[0] = c;
                 hex_buffer[1] = 0;
@@ -3758,8 +3902,8 @@ H5FD_s3comms_uriencode(char       *dest,
             for (hex_off = 0; hex_off < hex_len; hex_off++) {
                 dest[dest_off++] = hex_buffer[hex_off];
             }
-        }
-    }
+        } /* end else (not a regular character) */
+    } /* end for each character */
 
     if (dest_off < s_len)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL,
@@ -3769,7 +3913,6 @@ H5FD_s3comms_uriencode(char       *dest,
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
-
 } /* H5FD_s3comms_uriencode */
 
 
diff --git a/src/H5FDs3comms.h b/src/H5FDs3comms.h
index 93a5a81..16f6a8b 100644
--- a/src/H5FDs3comms.h
+++ b/src/H5FDs3comms.h
@@ -577,7 +577,9 @@ H5_DLL herr_t H5FD_s3comms_s3r_read(s3r_t   *handle,
 H5_DLL struct tm * gmnow(void);
 
 herr_t H5FD_s3comms_aws_canonical_request(char  *canonical_request_dest,
+                                          int    cr_size,
                                           char  *signed_headers_dest,
+                                          int    sh_size,
                                           hrb_t *http_request);
 
 H5_DLL herr_t H5FD_s3comms_bytes_to_hex(char                *dest,
diff --git a/src/H5Fint.c b/src/H5Fint.c
index 77b0cef..6aec40c 100644
--- a/src/H5Fint.c
+++ b/src/H5Fint.c
@@ -3647,7 +3647,7 @@ done:
  *-------------------------------------------------------------------------
  */
 hid_t
-H5F__get_file_id(H5F_t *file)
+H5F__get_file_id(H5F_t *file, hbool_t app_ref)
 {
     hid_t file_id = H5I_INVALID_HID;    /* File ID */
     hid_t ret_value = H5I_INVALID_HID;  /* Return value */
@@ -3660,13 +3660,13 @@ H5F__get_file_id(H5F_t *file)
 
     /* If the ID does not exist, register it with the VOL connector */
     if(H5I_INVALID_HID == file_id) {
-        if((file_id = H5VL_wrap_register(H5I_FILE, file, TRUE)) < 0)
+        if((file_id = H5VL_wrap_register(H5I_FILE, file, app_ref)) < 0)
             HGOTO_ERROR(H5E_FILE, H5E_CANTREGISTER, H5I_INVALID_HID, "unable to atomize file handle")
         file->id_exists = TRUE;
     } /* end if */
     else {
         /* Increment ref count on existing ID */
-        if(H5I_inc_ref(file_id, TRUE) < 0)
+        if(H5I_inc_ref(file_id, app_ref) < 0)
             HGOTO_ERROR(H5E_FILE, H5E_CANTSET, H5I_INVALID_HID, "incrementing file ID failed")
     } /* end else */
 
@@ -3690,7 +3690,7 @@ done:
  *-------------------------------------------------------------------------
  */
 hid_t
-H5F_get_file_id(hid_t obj_id, H5I_type_t type)
+H5F_get_file_id(hid_t obj_id, H5I_type_t type, hbool_t app_ref)
 {
     H5VL_object_t  *vol_obj;                    /* File info */
     hid_t           file_id = H5I_INVALID_HID;  /* File ID for object */
@@ -3703,7 +3703,7 @@ H5F_get_file_id(hid_t obj_id, H5I_type_t type)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "invalid identifier")
 
     /* Get the file through the VOL */
-    if(H5VL_file_optional(vol_obj, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, H5VL_NATIVE_FILE_GET_FILE_ID, (int)type, &file_id) < 0)
+    if(H5VL_file_optional(vol_obj, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, H5VL_NATIVE_FILE_GET_FILE_ID, (int)type, (int)app_ref, &file_id) < 0)
         HGOTO_ERROR(H5E_FILE, H5E_CANTINIT, H5I_INVALID_HID, "unable to get file ID")
     if(H5I_INVALID_HID == file_id)
         HGOTO_ERROR(H5E_FILE, H5E_CANTINIT, H5I_INVALID_HID, "unable to get the file ID through the VOL")
diff --git a/src/H5Fmpi.c b/src/H5Fmpi.c
index 5bbd717..12bcbc0 100644
--- a/src/H5Fmpi.c
+++ b/src/H5Fmpi.c
@@ -90,14 +90,14 @@ herr_t
 H5F_get_mpi_handle(const H5F_t *f, MPI_File **f_handle)
 {
     herr_t ret_value = SUCCEED;
-    hid_t fapl = -1;
+    hid_t fapl_id = H5I_INVALID_HID;
 
     FUNC_ENTER_NOAPI(FAIL)
 
     HDassert(f && f->shared);
 
     /* Dispatch to driver */
-    if ((ret_value = H5FD_get_vfd_handle(f->shared->lf, fapl, (void **)f_handle)) < 0)
+    if ((ret_value = H5FD_get_vfd_handle(f->shared->lf, fapl_id, (void **)f_handle)) < 0)
         HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "can't get mpi file handle")
 
 done:
@@ -106,33 +106,31 @@ done:
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5F_mpi_get_rank
+ * Function:    H5F_mpi_get_rank
  *
- * Purpose:	Retrieves the rank of an MPI process.
+ * Purpose:     Retrieves the rank of an MPI process.
  *
- * Return:	Success:	The rank (non-negative)
+ * Return:      Success:    The rank (non-negative)
  *
- *		Failure:	Negative
+ *              Failure:    Negative
  *
- * Programmer:	Quincey Koziol
+ * Programmer:  Quincey Koziol
  *              Friday, January 30, 2004
  *
- * Modifications:
- *
  *-------------------------------------------------------------------------
  */
 int
 H5F_mpi_get_rank(const H5F_t *f)
 {
-    int	ret_value;
+    int ret_value = -1;
 
-    FUNC_ENTER_NOAPI(FAIL)
+    FUNC_ENTER_NOAPI((-1))
 
     HDassert(f && f->shared);
 
     /* Dispatch to driver */
-    if ((ret_value=H5FD_mpi_get_rank(f->shared->lf)) < 0)
-        HGOTO_ERROR(H5E_VFL, H5E_CANTGET, FAIL, "driver get_rank request failed")
+    if ((ret_value = H5FD_mpi_get_rank(f->shared->lf)) < 0)
+        HGOTO_ERROR(H5E_VFL, H5E_CANTGET, (-1), "driver get_rank request failed")
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
@@ -140,32 +138,30 @@ done:
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5F_mpi_get_comm
+ * Function:    H5F_mpi_get_comm
  *
- * Purpose:	Retrieves the file's communicator
+ * Purpose:     Retrieves the file's communicator
  *
- * Return:	Success:	The communicator (non-negative)
+ * Return:      Success:    The communicator (non-negative)
  *
- *		Failure:	Negative
+ *              Failure:    Negative
  *
- * Programmer:	Quincey Koziol
+ * Programmer:  Quincey Koziol
  *              Friday, January 30, 2004
  *
- * Modifications:
- *
  *-------------------------------------------------------------------------
  */
 MPI_Comm
 H5F_mpi_get_comm(const H5F_t *f)
 {
-    MPI_Comm	ret_value;
+    MPI_Comm    ret_value = MPI_COMM_NULL;
 
     FUNC_ENTER_NOAPI(MPI_COMM_NULL)
 
     HDassert(f && f->shared);
 
     /* Dispatch to driver */
-    if ((ret_value=H5FD_mpi_get_comm(f->shared->lf))==MPI_COMM_NULL)
+    if ((ret_value = H5FD_mpi_get_comm(f->shared->lf)) == MPI_COMM_NULL)
         HGOTO_ERROR(H5E_VFL, H5E_CANTGET, MPI_COMM_NULL, "driver get_comm request failed")
 
 done:
@@ -185,22 +181,20 @@ done:
  * Programmer:  John Mainzer
  *              Friday, May 6, 2005
  *
- * Modifications:
- *
  *-------------------------------------------------------------------------
  */
 int
 H5F_mpi_get_size(const H5F_t *f)
 {
-    int ret_value;
+    int ret_value = -1;
 
-    FUNC_ENTER_NOAPI(FAIL)
+    FUNC_ENTER_NOAPI((-1))
 
     HDassert(f && f->shared);
 
     /* Dispatch to driver */
-    if ((ret_value=H5FD_mpi_get_size(f->shared->lf)) < 0)
-        HGOTO_ERROR(H5E_VFL, H5E_CANTGET, FAIL, "driver get_size request failed")
+    if ((ret_value = H5FD_mpi_get_size(f->shared->lf)) < 0)
+        HGOTO_ERROR(H5E_VFL, H5E_CANTGET, (-1), "driver get_size request failed")
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
@@ -208,16 +202,16 @@ done:
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5Fset_mpi_atomicity
+ * Function:    H5Fset_mpi_atomicity
  *
- * Purpose:	Sets the atomicity mode
+ * Purpose:     Sets the atomicity mode
  *
- * Return:	Success:	Non-negative
+ * Return:      Success:    Non-negative
  *
- * 		Failure:	Negative
+ *              Failure:    Negative
  *
- * Programmer:	Mohamad Chaarawi
- *		Feb 14, 2012
+ * Programmer:  Mohamad Chaarawi
+ *              Feb 14, 2012
  *
  *-------------------------------------------------------------------------
  */
@@ -248,16 +242,16 @@ done:
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5Fget_mpi_atomicity
+ * Function:    H5Fget_mpi_atomicity
  *
- * Purpose:	Returns the atomicity mode
+ * Purpose:     Returns the atomicity mode
  *
- * Return:	Success:	Non-negative
+ * Return:      Success:    Non-negative
  *
- * 		Failure:	Negative
+ *              Failure:    Negative
  *
- * Programmer:	Mohamad Chaarawi
- *		Feb 14, 2012
+ * Programmer:  Mohamad Chaarawi
+ *              Feb 14, 2012
  *
  *-------------------------------------------------------------------------
  */
@@ -288,18 +282,18 @@ done:
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5F_mpi_retrieve_comm
+ * Function:    H5F_mpi_retrieve_comm
  *
- * Purpose:	Retrieves an MPI communicator from the file the location ID 
+ * Purpose:     Retrieves an MPI communicator from the file the location ID 
  *              is in. If the loc_id is invalid, the fapl_id is used to 
  *              retrieve the communicator.
  *
- * Return:	Success:	Non-negative
+ * Return:      Success:    Non-negative
  *
- * 		Failure:	Negative
+ *              Failure:    Negative
  *
- * Programmer:	Mohamad Chaarawi
- *		Feb 14, 2012
+ * Programmer:  Mohamad Chaarawi
+ *              Feb 14, 2012
  *
  *-------------------------------------------------------------------------
  */
diff --git a/src/H5Fpkg.h b/src/H5Fpkg.h
index 1dd07c1..dbf68c3 100644
--- a/src/H5Fpkg.h
+++ b/src/H5Fpkg.h
@@ -408,7 +408,7 @@ H5_DLL herr_t H5F__start_swmr_write(H5F_t *f);
 H5_DLL herr_t H5F__close(H5F_t *f);
 H5_DLL herr_t H5F__set_libver_bounds(H5F_t *f, H5F_libver_t low, H5F_libver_t high);
 H5_DLL H5F_t *H5F__get_file(void *obj, H5I_type_t type);
-H5_DLL hid_t H5F__get_file_id(H5F_t *file);
+H5_DLL hid_t H5F__get_file_id(H5F_t *file, hbool_t app_ref);
 
 /* File mount related routines */
 H5_DLL herr_t H5F__mount(H5G_loc_t *loc, const char *name, H5F_t *child, hid_t plist_id);
diff --git a/src/H5Fprivate.h b/src/H5Fprivate.h
index a8ac158..838fa28 100644
--- a/src/H5Fprivate.h
+++ b/src/H5Fprivate.h
@@ -718,7 +718,7 @@ typedef enum H5F_prefix_open_t {
 /* Private functions */
 H5_DLL H5F_t *H5F_open(const char *name, unsigned flags, hid_t fcpl_id, hid_t fapl_id);
 H5_DLL herr_t H5F_try_close(H5F_t *f, hbool_t *was_closed/*out*/);
-H5_DLL hid_t H5F_get_file_id(hid_t obj_id, H5I_type_t id_type);
+H5_DLL hid_t H5F_get_file_id(hid_t obj_id, H5I_type_t id_type, hbool_t app_ref);
 
 /* Functions that retrieve values from the file struct */
 H5_DLL H5F_libver_t H5F_get_low_bound(const H5F_t *f);
diff --git a/src/H5I.c b/src/H5I.c
index a2275de..ab68e38 100644
--- a/src/H5I.c
+++ b/src/H5I.c
@@ -2219,7 +2219,7 @@ H5Iget_file_id(hid_t obj_id)
 
     /* Call internal function */
     if (H5I_FILE == type || H5I_DATATYPE == type || H5I_GROUP == type || H5I_DATASET == type || H5I_ATTR == type) {
-        if ((ret_value = H5F_get_file_id(obj_id, type)) < 0)
+        if ((ret_value = H5F_get_file_id(obj_id, type, TRUE)) < 0)
             HGOTO_ERROR(H5E_ATOM, H5E_CANTGET, H5I_INVALID_HID, "can't retrieve file ID")
     } /* end if */
     else
diff --git a/src/H5Shyper.c b/src/H5Shyper.c
index 492cd9e..153f4be 100644
--- a/src/H5Shyper.c
+++ b/src/H5Shyper.c
@@ -7025,6 +7025,47 @@ done:
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5S_hyper_adjust_s() */
 
+/*--------------------------------------------------------------------------
+ NAME
+    H5Shyper_adjust_s
+ PURPOSE
+    Adjust a hyperslab selection by subtracting an offset
+ USAGE
+    herr_t H5Shyper_adjust_s(space_id,offset)
+        hid_t space_id;         IN: ID of the dataspace to adjust
+        const hssize_t *offset; IN: Offset to subtract
+ RETURNS
+    Non-negative on success, negative on failure
+ DESCRIPTION
+    Moves a hyperslab selection by subtracting an offset from it.
+ GLOBAL VARIABLES
+ COMMENTS, BUGS, ASSUMPTIONS
+ EXAMPLES
+ REVISION LOG
+--------------------------------------------------------------------------*/
+herr_t
+H5Shyper_adjust_s(hid_t space_id, const hssize_t *offset)
+{
+    H5S_t *space;
+    herr_t ret_value = SUCCEED;         /* Return value */
+
+    FUNC_ENTER_API(FAIL)
+    H5TRACE2("e", "i*Hs", space_id, offset);
+
+    if(NULL == (space = (H5S_t *)H5I_object_verify(space_id, H5I_DATASPACE)))
+        HGOTO_ERROR(H5E_DATASPACE, H5E_BADTYPE, FAIL, "not a dataspace")
+    if(H5S_GET_SELECT_TYPE(space) != H5S_SEL_HYPERSLABS)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a hyperslab selection")
+    if(NULL == offset)
+        HGOTO_ERROR(H5E_DATASPACE, H5E_BADTYPE, FAIL, "NULL offset pointer")
+
+    if(H5S_hyper_adjust_s(space, offset) < 0)
+        HGOTO_ERROR(H5E_DATASPACE, H5E_CANTSET, FAIL, "can't adjust selection")
+
+done:
+    FUNC_LEAVE_API(ret_value)
+} /* end H5Shyper_adjust_s() */
+
 
 /*--------------------------------------------------------------------------
  NAME
diff --git a/src/H5Spublic.h b/src/H5Spublic.h
index 9e76b4b..a04f3c1 100644
--- a/src/H5Spublic.h
+++ b/src/H5Spublic.h
@@ -143,6 +143,7 @@ H5_DLL H5S_sel_type H5Sget_select_type(hid_t spaceid);
 H5_DLL hssize_t H5Sget_select_npoints(hid_t spaceid);
 H5_DLL herr_t H5Sselect_copy(hid_t dst_id, hid_t src_id);
 H5_DLL htri_t H5Sselect_valid(hid_t spaceid);
+H5_DLL herr_t H5Sselect_adjust_u(hid_t spaceid, const hsize_t *offset);
 H5_DLL herr_t H5Sget_select_bounds(hid_t spaceid, hsize_t start[],
     hsize_t end[]);
 H5_DLL htri_t H5Sselect_shape_same(hid_t space1_id, hid_t space2_id);
@@ -170,6 +171,7 @@ H5_DLL htri_t H5Sget_regular_hyperslab(hid_t spaceid, hsize_t start[],
 H5_DLL hssize_t H5Sget_select_hyper_nblocks(hid_t spaceid);
 H5_DLL herr_t H5Sget_select_hyper_blocklist(hid_t spaceid, hsize_t startblock,
     hsize_t numblocks, hsize_t buf[/*numblocks*/]);
+H5_DLL herr_t H5Shyper_adjust_s(hid_t space_id, const hssize_t *offset);
 
 /* Operations on dataspace selection iterators */
 H5_DLL hid_t H5Ssel_iter_create(hid_t spaceid, size_t elmt_size, unsigned flags);
diff --git a/src/H5Sselect.c b/src/H5Sselect.c
index e632b11..1a13f2c 100644
--- a/src/H5Sselect.c
+++ b/src/H5Sselect.c
@@ -971,6 +971,45 @@ H5S_select_adjust_u(H5S_t *space, const hsize_t *offset)
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5S_select_adjust_u() */
 
+/*--------------------------------------------------------------------------
+ NAME
+    H5Sselect_adjust_u
+ PURPOSE
+    Adjust a selection by subtracting an offset
+ USAGE
+    herr_t H5Sselect_adjust_u(space_id, offset)
+        hid_t space_id;        IN: ID of dataspace to adjust
+        const hsize_t *offset; IN: Offset to subtract
+ RETURNS
+    Non-negative on success, negative on failure
+ DESCRIPTION
+    Moves a selection by subtracting an offset from it.
+ GLOBAL VARIABLES
+ COMMENTS, BUGS, ASSUMPTIONS
+ EXAMPLES
+ REVISION LOG
+--------------------------------------------------------------------------*/
+herr_t
+H5Sselect_adjust_u(hid_t space_id, const hsize_t *offset)
+{
+    H5S_t *space;
+    herr_t ret_value = SUCCEED;         /* Return value */
+
+    FUNC_ENTER_API(FAIL)
+    H5TRACE2("e", "i*h", space_id, offset);
+
+    if(NULL == (space = (H5S_t *)H5I_object_verify(space_id, H5I_DATASPACE)))
+        HGOTO_ERROR(H5E_DATASPACE, H5E_BADTYPE, FAIL, "not a dataspace")
+    if(NULL == offset)
+        HGOTO_ERROR(H5E_DATASPACE, H5E_BADTYPE, FAIL, "NULL offset pointer")
+
+    if(H5S_select_adjust_u(space, offset) < 0)
+        HGOTO_ERROR(H5E_DATASPACE, H5E_CANTSET, FAIL, "can't adjust selection");
+
+done:
+    FUNC_LEAVE_API(ret_value)
+} /* end H5Sselect_adjust_u() */
+
 
 /*--------------------------------------------------------------------------
  NAME
diff --git a/src/H5VLnative_file.c b/src/H5VLnative_file.c
index eeaade6..0ac70e3 100644
--- a/src/H5VLnative_file.c
+++ b/src/H5VLnative_file.c
@@ -562,11 +562,12 @@ H5VL__native_file_optional(void *obj, hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR
         case H5VL_NATIVE_FILE_GET_FILE_ID:
             {
                 H5I_type_t  type = (H5I_type_t)HDva_arg(arguments, int); /* enum work-around */
+                hbool_t     app_ref = (hbool_t)HDva_arg(arguments, int);
                 hid_t      *file_id = HDva_arg(arguments, hid_t *);
 
                 if(NULL == (f = H5F__get_file(obj, type)))
                     HGOTO_ERROR(H5E_FILE, H5E_BADTYPE, FAIL, "not a file or file object")
-                if((*file_id = H5F__get_file_id(f)) < 0)
+                if((*file_id = H5F__get_file_id(f, app_ref)) < 0)
                     HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "can't get file ID")
                 break;
             }
diff --git a/src/H5mpi.c b/src/H5mpi.c
new file mode 100644
index 0000000..ea6b33f
--- /dev/null
+++ b/src/H5mpi.c
@@ -0,0 +1,198 @@
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ * Copyright by The HDF Group.                                               *
+ * Copyright by the Board of Trustees of the University of Illinois.         *
+ * All rights reserved.                                                      *
+ *                                                                           *
+ * This file is part of HDF5.  The full HDF5 copyright notice, including     *
+ * terms governing use, modification, and redistribution, is contained in    *
+ * the COPYING file, which can be found at the root of the source code       *
+ * distribution tree, or in https://support.hdfgroup.org/ftp/HDF5/releases.  *
+ * If you do not have access to either file, you may request a copy from     *
+ * help@hdfgroup.org.                                                        *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+/*
+ * Purpose:     Common MPI routines
+ *
+ */
+
+
+#include "H5private.h"          /* Generic Functions                        */
+#include "H5CXprivate.h"        /* API Contexts                             */
+#include "H5Eprivate.h"         /* Error handling                           */
+#include "H5Fprivate.h"         /* File access                              */
+#include "H5FDprivate.h"        /* File drivers                             */
+#include "H5FDmpi.h"            /* Common MPI file driver                   */
+#include "H5Pprivate.h"         /* Property lists                           */
+
+#ifdef H5_HAVE_PARALLEL
+
+/*-------------------------------------------------------------------------
+ * Function:    H5_mpi_comm_dup
+ *
+ * Purpose:     Duplicate an MPI communicator.
+ *
+ *              The new communicator is returned via the comm_new pointer.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5_mpi_comm_dup(MPI_Comm comm, MPI_Comm *comm_new)
+{
+    herr_t      ret_value = SUCCEED;
+    MPI_Comm    comm_dup = MPI_COMM_NULL;
+    int         mpi_code;
+
+    FUNC_ENTER_NOAPI(FAIL)
+
+    /* Check arguments */
+    if (!comm_new)
+        HGOTO_ERROR(H5E_INTERNAL, H5E_BADVALUE, FAIL, "comm_new cannot be NULL")
+    if (MPI_COMM_NULL == comm)
+        HGOTO_ERROR(H5E_INTERNAL, H5E_BADVALUE, FAIL, "can't duplicate MPI_COMM_NULL")
+
+    /* Duplicate the MPI communicator */
+    if (MPI_SUCCESS != (mpi_code = MPI_Comm_dup(comm, &comm_dup)))
+        HMPI_GOTO_ERROR(FAIL, "MPI_Comm_dup failed", mpi_code)
+
+    /* Set MPI_ERRORS_RETURN on comm_dup so that MPI failures are not fatal, 
+     * and return codes can be checked and handled.
+     */
+    if (MPI_SUCCESS != (mpi_code = MPI_Comm_set_errhandler(comm_dup, MPI_ERRORS_RETURN)))
+        HMPI_GOTO_ERROR(FAIL, "MPI_Errhandler_set failed", mpi_code)
+ 
+    /* Copy the new communicator to the return argument */
+    *comm_new = comm_dup;
+
+done:
+    if (FAIL == ret_value) {
+        /* need to free anything created here */
+        if (MPI_COMM_NULL != comm_dup)
+            MPI_Comm_free(&comm_dup);
+    }
+
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5_mpi_comm_dup() */ 
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5_mpi_info_dup
+ *
+ * Purpose:     Duplicate an MPI info.
+ *
+ *              If the info object is MPI_INFO_NULL, no duplicate
+ *              is made but the same value assigned to the new info object
+ *              handle.
+ *
+ *              The new info is returned via the info_new pointer.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5_mpi_info_dup(MPI_Info info, MPI_Info *info_new)
+{
+    herr_t      ret_value = SUCCEED;
+    MPI_Info    info_dup = MPI_INFO_NULL;
+    int         mpi_code;
+
+    FUNC_ENTER_NOAPI(FAIL)
+
+    /* Check arguments */
+    if (!info_new)
+        HGOTO_ERROR(H5E_INTERNAL, H5E_BADVALUE, FAIL, "info_new cannot be NULL")
+
+    /* Duplicate the MPI info */
+    if (info == MPI_INFO_NULL) {
+        /* Don't duplicate MPI_INFO_NULL. Just copy it. */
+        info_dup = info;
+    }
+    else {
+        /* Duplicate the info */
+        if (MPI_SUCCESS != (mpi_code = MPI_Info_dup(info, &info_dup)))
+            HMPI_GOTO_ERROR(FAIL, "MPI_Info_dup failed", mpi_code)
+    }
+
+    /* Copy the new info to the return argument */
+    *info_new = info_dup;
+
+done:
+    if (FAIL == ret_value) {
+        /* need to free anything created here */
+        if (MPI_INFO_NULL != info_dup)
+            MPI_Info_free(&info_dup);
+    }
+
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5_mpi_info_dup() */ 
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5_mpi_comm_free
+ *
+ * Purpose:     Free an MPI communicator.
+ *
+ *              If comm is MPI_COMM_NULL this call does nothing.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5_mpi_comm_free(MPI_Comm *comm)
+{
+    herr_t      ret_value = SUCCEED;
+
+    FUNC_ENTER_NOAPI(FAIL)
+
+    /* Check arguments */
+    if (!comm)
+        HGOTO_ERROR(H5E_INTERNAL, H5E_BADVALUE, FAIL, "comm pointer cannot be NULL")
+
+    /* Free the communicator */
+    if (MPI_COMM_NULL != *comm)
+        MPI_Comm_free(comm);
+
+    *comm = MPI_COMM_NULL;
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* End H5_mpi_comm_free() */
+
+/*-------------------------------------------------------------------------
+ * Function:    H5_mpi_info_free
+ *
+ * Purpose:     Free the MPI info.
+ *
+ *              If info is MPI_INFO_NULL this call does nothing.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5_mpi_info_free(MPI_Info *info)
+{
+    herr_t      ret_value = SUCCEED;
+
+    FUNC_ENTER_NOAPI(FAIL)
+
+    /* Check arguments */
+    if (!info)
+        HGOTO_ERROR(H5E_INTERNAL, H5E_BADVALUE, FAIL, "info pointer cannot be NULL")
+
+    /* Free the info */
+    if (MPI_INFO_NULL != *info)
+        MPI_Info_free(info);
+
+    *info = MPI_INFO_NULL;
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* End H5_mpi_info_free() */
+
+#endif /* H5_HAVE_PARALLEL */
+
diff --git a/src/H5private.h b/src/H5private.h
index 537e860..18b52a0 100644
--- a/src/H5private.h
+++ b/src/H5private.h
@@ -2668,6 +2668,14 @@ H5_DLL double H5_get_time(void);
 H5_DLL herr_t   H5_build_extpath(const char *name, char **extpath /*out*/);
 H5_DLL herr_t   H5_combine_path(const char *path1, const char *path2, char **full_name /*out*/);
 
+#ifdef H5_HAVE_PARALLEL
+/* Generic MPI functions */
+H5_DLL herr_t   H5_mpi_comm_dup(MPI_Comm comm, MPI_Comm *comm_new);
+H5_DLL herr_t   H5_mpi_info_dup(MPI_Info info, MPI_Info *info_new);
+H5_DLL herr_t   H5_mpi_comm_free(MPI_Comm *comm);
+H5_DLL herr_t   H5_mpi_info_free(MPI_Info *info);
+#endif /* H5_HAVE_PARALLEL */
+
 /* Functions for debugging */
 H5_DLL herr_t H5_buffer_dump(FILE *stream, int indent, const uint8_t *buf,
     const uint8_t *marker, size_t buf_offset, size_t buf_size);
diff --git a/src/Makefile.am b/src/Makefile.am
index 1e6578e..1e1273c 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -126,7 +126,7 @@ libhdf5_la_SOURCES= H5.c H5checksum.c H5dbg.c H5system.c H5timer.c H5trace.c \
 
 # Only compile parallel sources if necessary
 if BUILD_PARALLEL_CONDITIONAL
-    libhdf5_la_SOURCES += H5ACmpio.c H5Cmpio.c H5Dmpio.c H5Fmpi.c H5FDmpi.c H5FDmpio.c H5Smpio.c
+    libhdf5_la_SOURCES += H5mpi.c H5ACmpio.c H5Cmpio.c H5Dmpio.c H5Fmpi.c H5FDmpi.c H5FDmpio.c H5Smpio.c
 endif
 
 # Only compile the direct VFD if necessary