Clang-format of source files

1 files changed, 1831 insertions, 1797 deletions

diff --git a/tools/test/perform/pio_engine.c b/tools/test/perform/pio_engine.c
index cdd698e..4e690d5 100644
--- a/tools/test/perform/pio_engine.c
+++ b/tools/test/perform/pio_engine.c
@@ -36,64 +36,65 @@
 
 #include <mpi.h>
 
-#ifndef MPI_FILE_NULL           /*MPIO may be defined in mpi.h already       */
-#   include <mpio.h>
-#endif  /* !MPI_FILE_NULL */
+#ifndef MPI_FILE_NULL /*MPIO may be defined in mpi.h already       */
+#include <mpio.h>
+#endif /* !MPI_FILE_NULL */
 
 #include "pio_perf.h"
 
 /* Macro definitions */
 
 #if H5_VERS_MAJOR == 1 && H5_VERS_MINOR == 6
-#    define H5DCREATE(fd, name, type, space, dcpl)    H5Dcreate(fd, name, type, space, dcpl)
-#    define H5DOPEN(fd, name)                         H5Dopen(fd, name)
+#define H5DCREATE(fd, name, type, space, dcpl) H5Dcreate(fd, name, type, space, dcpl)
+#define H5DOPEN(fd, name)                      H5Dopen(fd, name)
 #else
-#    define H5DCREATE(fd, name, type, space, dcpl)    H5Dcreate2(fd, name, type, space, H5P_DEFAULT, dcpl, H5P_DEFAULT)
-#    define H5DOPEN(fd, name)                         H5Dopen2(fd, name, H5P_DEFAULT)
+#define H5DCREATE(fd, name, type, space, dcpl)                                                               \
+    H5Dcreate2(fd, name, type, space, H5P_DEFAULT, dcpl, H5P_DEFAULT)
+#define H5DOPEN(fd, name) H5Dopen2(fd, name, H5P_DEFAULT)
 #endif
 
 /* sizes of various items. these sizes won't change during program execution */
 /* The following three must have the same type */
-#define ELMT_H5_TYPE        H5T_NATIVE_UCHAR
+#define ELMT_H5_TYPE H5T_NATIVE_UCHAR
 
-#define GOTOERROR(errcode)  { ret_code = errcode; goto done; }
-#define ERRMSG(mesg) {                                                  \
-    HDfprintf(stderr, "Proc %d: ", pio_mpi_rank_g);                       \
-    HDfprintf(stderr, "*** Assertion failed (%s) at line %4d in %s\n",    \
-        mesg, (int)__LINE__, __FILE__);                             \
-}
+#define GOTOERROR(errcode)                                                                                   \
+    {                                                                                                        \
+        ret_code = errcode;                                                                                  \
+        goto done;                                                                                           \
+    }
+#define ERRMSG(mesg)                                                                                         \
+    {                                                                                                        \
+        HDfprintf(stderr, "Proc %d: ", pio_mpi_rank_g);                                                      \
+        HDfprintf(stderr, "*** Assertion failed (%s) at line %4d in %s\n", mesg, (int)__LINE__, __FILE__);   \
+    }
 
 /* verify: if val is false (0), print mesg. */
-#define VRFY(val, mesg) do {                            \
-    if (!val) {                                         \
-    ERRMSG(mesg);                                   \
-    GOTOERROR(FAIL);                                \
-    }                                                   \
-} while(0)
-
+#define VRFY(val, mesg)                                                                                      \
+    do {                                                                                                     \
+        if (!val) {                                                                                          \
+            ERRMSG(mesg);                                                                                    \
+            GOTOERROR(FAIL);                                                                                 \
+        }                                                                                                    \
+    } while (0)
 
 /* POSIX I/O macros */
 #ifdef H5_HAVE_WIN32_API
 /* Can't link against the library, so this test will use the older, non-Unicode
  * _open() call on Windows.
  */
-#define HDopen(S,F,...)           _open(S, F | _O_BINARY, __VA_ARGS__)
+#define HDopen(S, F, ...) _open(S, F | _O_BINARY, __VA_ARGS__)
 #endif /* H5_HAVE_WIN32_API */
-#define POSIXCREATE(fn)           HDopen(fn, O_CREAT|O_TRUNC|O_RDWR, 0600)
-#define POSIXOPEN(fn, F)          HDopen(fn, F, 0600)
-#define POSIXCLOSE(F)             HDclose(F)
-#define POSIXSEEK(F,L)            HDlseek(F, L, SEEK_SET)
-#define POSIXWRITE(F,B,S)         HDwrite(F,B,S)
-#define POSIXREAD(F,B,S)          HDread(F,B,S)
-
-enum {
-    PIO_CREATE = 1,
-    PIO_WRITE = 2,
-    PIO_READ = 4
-};
+#define POSIXCREATE(fn)     HDopen(fn, O_CREAT | O_TRUNC | O_RDWR, 0600)
+#define POSIXOPEN(fn, F)    HDopen(fn, F, 0600)
+#define POSIXCLOSE(F)       HDclose(F)
+#define POSIXSEEK(F, L)     HDlseek(F, L, SEEK_SET)
+#define POSIXWRITE(F, B, S) HDwrite(F, B, S)
+#define POSIXREAD(F, B, S)  HDread(F, B, S)
+
+enum { PIO_CREATE = 1, PIO_WRITE = 2, PIO_READ = 4 };
 
 /* Global variables */
-static int  clean_file_g = -1;  /*whether to cleanup temporary test     */
+static int clean_file_g = -1; /*whether to cleanup temporary test     */
 /*files. -1 is not defined;             */
 /*0 is no cleanup; 1 is do cleanup      */
 
@@ -104,32 +105,30 @@ static int  clean_file_g = -1;  /*whether to cleanup temporary test     */
  * is about the best guess.
  */
 #ifndef HDF5_PARAPREFIX
-#    define HDF5_PARAPREFIX     ""
-#endif  /* !HDF5_PARAPREFIX */
+#define HDF5_PARAPREFIX ""
+#endif /* !HDF5_PARAPREFIX */
 
 #ifndef MIN
-#   define MIN(a,b) ((a) < (b) ? (a) : (b))
-#endif  /* !MIN */
+#define MIN(a, b) ((a) < (b) ? (a) : (b))
+#endif /* !MIN */
 
 /* the different types of file descriptors we can expect */
 typedef union _file_descr {
-    int         posixfd;    /* POSIX file handle*/
-    MPI_File    mpifd;      /* MPI file         */
-    hid_t       h5fd;       /* HDF5 file        */
+    int      posixfd; /* POSIX file handle*/
+    MPI_File mpifd;   /* MPI file         */
+    hid_t    h5fd;    /* HDF5 file        */
 } file_descr;
 
 /* local functions */
-static char  *pio_create_filename(iotype iot, const char *base_name,
-    char *fullname, size_t size);
-static herr_t do_write(results *res, file_descr *fd, parameters *parms,
-    long ndsets, off_t nelmts, size_t buf_size, void *buffer);
-static herr_t do_read(results *res, file_descr *fd, parameters *parms,
-    long ndsets, off_t nelmts, size_t buf_size, void *buffer /*out*/);
-static herr_t do_fopen(parameters *param, char *fname, file_descr *fd /*out*/,
-    int flags);
+static char * pio_create_filename(iotype iot, const char *base_name, char *fullname, size_t size);
+static herr_t do_write(results *res, file_descr *fd, parameters *parms, long ndsets, off_t nelmts,
+                       size_t buf_size, void *buffer);
+static herr_t do_read(results *res, file_descr *fd, parameters *parms, long ndsets, off_t nelmts,
+                      size_t buf_size, void *buffer /*out*/);
+static herr_t do_fopen(parameters *param, char *fname, file_descr *fd /*out*/, int flags);
 static herr_t do_fclose(iotype iot, file_descr *fd);
-static void do_cleanupfile(iotype iot, char *fname);
-static off_t sqrto(off_t);
+static void   do_cleanupfile(iotype iot, char *fname);
+static off_t  sqrto(off_t);
 
 /*
  * Function:        do_pio
@@ -139,32 +138,32 @@ static off_t sqrto(off_t);
  * Modifications:
  *  Added 2D testing (Christian Chilan, 10. August 2005)
  */
-    results
+results
 do_pio(parameters param)
 {
     /* return codes */
-    herr_t      ret_code = 0;   /*return code                           */
-    results     res;
-
-    file_descr  fd;
-    iotype      iot;
-
-    char        fname[FILENAME_MAX];
-    long    nf;
-    long        ndsets;
-    off_t       nbytes;         /*number of bytes per dataset  */
-    off_t   snbytes;    /*general dataset size          */
-                                /*for 1D, it is the actual dataset size */
-                                /*for 2D, it is the size of a side of the dataset square */
-    char        *buffer = NULL; /*data buffer pointer           */
-    size_t      buf_size;       /*general buffer size in bytes     */
-                                /*for 1D, it is the actual buffer size */
-                                /*for 2D, it is the length of the buffer rectangle */
-    size_t      blk_size;       /*data block size in bytes      */
-    size_t  bsize;      /*actual buffer size            */
+    herr_t  ret_code = 0; /*return code                           */
+    results res;
+
+    file_descr fd;
+    iotype     iot;
+
+    char  fname[FILENAME_MAX];
+    long  nf;
+    long  ndsets;
+    off_t nbytes;         /*number of bytes per dataset  */
+    off_t snbytes;        /*general dataset size          */
+                          /*for 1D, it is the actual dataset size */
+                          /*for 2D, it is the size of a side of the dataset square */
+    char * buffer = NULL; /*data buffer pointer           */
+    size_t buf_size;      /*general buffer size in bytes     */
+                          /*for 1D, it is the actual buffer size */
+                          /*for 2D, it is the length of the buffer rectangle */
+    size_t blk_size;      /*data block size in bytes      */
+    size_t bsize;         /*actual buffer size            */
 
     /* HDF5 variables */
-    herr_t          hrc;        /*HDF5 return code              */
+    herr_t hrc; /*HDF5 return code              */
 
     /* Sanity check parameters */
 
@@ -173,7 +172,7 @@ do_pio(parameters param)
 
     switch (iot) {
         case MPIO:
-            fd.mpifd = MPI_FILE_NULL;
+            fd.mpifd   = MPI_FILE_NULL;
             res.timers = io_time_new(MPI_CLOCK);
             break;
         case POSIXIO:
@@ -181,7 +180,7 @@ do_pio(parameters param)
             res.timers = io_time_new(MPI_CLOCK);
             break;
         case PHDF5:
-            fd.h5fd = -1;
+            fd.h5fd    = -1;
             res.timers = io_time_new(MPI_CLOCK);
             break;
         default:
@@ -190,168 +189,158 @@ do_pio(parameters param)
             GOTOERROR(FAIL);
     }
 
-    ndsets = param.num_dsets;       /* number of datasets per file          */
-    nbytes = param.num_bytes;       /* number of bytes per dataset          */
+    ndsets   = param.num_dsets; /* number of datasets per file          */
+    nbytes   = param.num_bytes; /* number of bytes per dataset          */
     buf_size = param.buf_size;
     blk_size = param.blk_size;
 
-    if (!param.dim2d){
+    if (!param.dim2d) {
         snbytes = nbytes;   /* General dataset size     */
-        bsize = buf_size;   /* Actual buffer size       */
+        bsize   = buf_size; /* Actual buffer size       */
     }
     else {
-        snbytes = sqrto(nbytes);  /* General dataset size     */
-        bsize = buf_size * blk_size;    /* Actual buffer size       */
+        snbytes = sqrto(nbytes);       /* General dataset size     */
+        bsize   = buf_size * blk_size; /* Actual buffer size       */
     }
 
-    if (param.num_files < 0 ) {
-    HDfprintf(stderr,
-        "number of files must be >= 0 (%ld)\n",
-        param.num_files);
-    GOTOERROR(FAIL);
+    if (param.num_files < 0) {
+        HDfprintf(stderr, "number of files must be >= 0 (%ld)\n", param.num_files);
+        GOTOERROR(FAIL);
     }
 
-    if (ndsets < 0 ) {
-    HDfprintf(stderr,
-        "number of datasets per file must be >= 0 (%ld)\n",
-        ndsets);
-    GOTOERROR(FAIL);
+    if (ndsets < 0) {
+        HDfprintf(stderr, "number of datasets per file must be >= 0 (%ld)\n", ndsets);
+        GOTOERROR(FAIL);
     }
 
-    if (param.num_procs <= 0 ) {
-    HDfprintf(stderr,
-        "maximum number of process to use must be > 0 (%d)\n",
-        param.num_procs);
-    GOTOERROR(FAIL);
+    if (param.num_procs <= 0) {
+        HDfprintf(stderr, "maximum number of process to use must be > 0 (%d)\n", param.num_procs);
+        GOTOERROR(FAIL);
     }
 
     /* Validate transfer buffer size & block size*/
-    if(blk_size<=0) {
-    HDfprintf(stderr,
-        "Transfer block size (%zu) must be > 0\n", blk_size);
-    GOTOERROR(FAIL);
-    }
-    if(buf_size<=0) {
-    HDfprintf(stderr,
-        "Transfer buffer size (%zu) must be > 0\n", buf_size);
-    GOTOERROR(FAIL);
+    if (blk_size <= 0) {
+        HDfprintf(stderr, "Transfer block size (%zu) must be > 0\n", blk_size);
+        GOTOERROR(FAIL);
     }
-    if ((buf_size % blk_size) != 0){
-    HDfprintf(stderr,
-        "Transfer buffer size (%zu) must be a multiple of the "
-        "interleaved I/O block size (%zu)\n",
-        buf_size, blk_size);
-    GOTOERROR(FAIL);
+    if (buf_size <= 0) {
+        HDfprintf(stderr, "Transfer buffer size (%zu) must be > 0\n", buf_size);
+        GOTOERROR(FAIL);
     }
-    if((snbytes%pio_mpi_nprocs_g)!=0) {
-    HDfprintf(stderr,
-              "Dataset size (%" H5_PRINTF_LL_WIDTH "d) must be a multiple of the "
-              "number of processes (%d)\n",
-              (long long)snbytes, pio_mpi_nprocs_g);
-    GOTOERROR(FAIL);
+    if ((buf_size % blk_size) != 0) {
+        HDfprintf(stderr,
+                  "Transfer buffer size (%zu) must be a multiple of the "
+                  "interleaved I/O block size (%zu)\n",
+                  buf_size, blk_size);
+        GOTOERROR(FAIL);
     }
-
-    if (!param.dim2d){
-        if(((size_t)(snbytes/pio_mpi_nprocs_g)%buf_size)!=0) {
+    if ((snbytes % pio_mpi_nprocs_g) != 0) {
         HDfprintf(stderr,
-            "Dataset size/process (%" H5_PRINTF_LL_WIDTH "d) must be a multiple of the "
-            "trasfer buffer size (%zu)\n",
-            (long long)(snbytes/pio_mpi_nprocs_g), buf_size);
+                  "Dataset size (%" H5_PRINTF_LL_WIDTH "d) must be a multiple of the "
+                  "number of processes (%d)\n",
+                  (long long)snbytes, pio_mpi_nprocs_g);
         GOTOERROR(FAIL);
+    }
+
+    if (!param.dim2d) {
+        if (((size_t)(snbytes / pio_mpi_nprocs_g) % buf_size) != 0) {
+            HDfprintf(stderr,
+                      "Dataset size/process (%" H5_PRINTF_LL_WIDTH "d) must be a multiple of the "
+                      "trasfer buffer size (%zu)\n",
+                      (long long)(snbytes / pio_mpi_nprocs_g), buf_size);
+            GOTOERROR(FAIL);
         }
     }
     else {
-        if(((size_t)snbytes%buf_size)!=0) {
-        HDfprintf(stderr,
-            "Dataset side size (%" H5_PRINTF_LL_WIDTH "d) must be a multiple of the "
-            "trasfer buffer size (%zu)\n",
-            (long long)snbytes, buf_size);
-        GOTOERROR(FAIL);
+        if (((size_t)snbytes % buf_size) != 0) {
+            HDfprintf(stderr,
+                      "Dataset side size (%" H5_PRINTF_LL_WIDTH "d) must be a multiple of the "
+                      "trasfer buffer size (%zu)\n",
+                      (long long)snbytes, buf_size);
+            GOTOERROR(FAIL);
         }
     }
 
     /* Allocate transfer buffer */
-    if ((buffer = malloc(bsize)) == NULL){
-    HDfprintf(stderr, "malloc for transfer buffer size (%zu) failed\n",
-        bsize);
-    GOTOERROR(FAIL);
+    if ((buffer = malloc(bsize)) == NULL) {
+        HDfprintf(stderr, "malloc for transfer buffer size (%zu) failed\n", bsize);
+        GOTOERROR(FAIL);
     }
 
     if (pio_debug_level >= 4) {
-    int myrank;
+        int myrank;
 
-    MPI_Comm_rank(pio_comm_g, &myrank);
+        MPI_Comm_rank(pio_comm_g, &myrank);
 
-    /* output all of the times for all iterations */
-    if (myrank == 0)
-        HDfprintf(output, "Timer details:\n");
+        /* output all of the times for all iterations */
+        if (myrank == 0)
+            HDfprintf(output, "Timer details:\n");
     }
 
     for (nf = 1; nf <= param.num_files; nf++) {
-    /*
-     * Write performance measurement
-     */
-    /* Open file for write */
-    char base_name[256];
+        /*
+         * Write performance measurement
+         */
+        /* Open file for write */
+        char base_name[256];
 
-    HDsprintf(base_name, "#pio_tmp_%lu", nf);
-    pio_create_filename(iot, base_name, fname, sizeof(fname));
-    if (pio_debug_level > 0)
-        HDfprintf(output, "rank %d: data filename=%s\n",
-            pio_mpi_rank_g, fname);
+        HDsprintf(base_name, "#pio_tmp_%lu", nf);
+        pio_create_filename(iot, base_name, fname, sizeof(fname));
+        if (pio_debug_level > 0)
+            HDfprintf(output, "rank %d: data filename=%s\n", pio_mpi_rank_g, fname);
 
-    /* Need barrier to make sure everyone starts at the same time */
-    MPI_Barrier(pio_comm_g);
+        /* Need barrier to make sure everyone starts at the same time */
+        MPI_Barrier(pio_comm_g);
 
-    io_time_set(res.timers, HDF5_GROSS_WRITE_FIXED_DIMS, TSTART);
-    hrc = do_fopen(&param, fname, &fd, PIO_CREATE | PIO_WRITE);
+        io_time_set(res.timers, HDF5_GROSS_WRITE_FIXED_DIMS, TSTART);
+        hrc = do_fopen(&param, fname, &fd, PIO_CREATE | PIO_WRITE);
 
-    VRFY((hrc == SUCCESS), "do_fopen failed");
+        VRFY((hrc == SUCCESS), "do_fopen failed");
 
-    io_time_set(res.timers, HDF5_FINE_WRITE_FIXED_DIMS, TSTART);
-    hrc = do_write(&res, &fd, &param, ndsets, nbytes, buf_size, buffer);
-    io_time_set(res.timers, HDF5_FINE_WRITE_FIXED_DIMS, TSTOP);
+        io_time_set(res.timers, HDF5_FINE_WRITE_FIXED_DIMS, TSTART);
+        hrc = do_write(&res, &fd, &param, ndsets, nbytes, buf_size, buffer);
+        io_time_set(res.timers, HDF5_FINE_WRITE_FIXED_DIMS, TSTOP);
 
-    VRFY((hrc == SUCCESS), "do_write failed");
+        VRFY((hrc == SUCCESS), "do_write failed");
 
-    /* Close file for write */
-    hrc = do_fclose(iot, &fd);
+        /* Close file for write */
+        hrc = do_fclose(iot, &fd);
 
-    io_time_set(res.timers, HDF5_GROSS_WRITE_FIXED_DIMS, TSTOP);
-    VRFY((hrc == SUCCESS), "do_fclose failed");
+        io_time_set(res.timers, HDF5_GROSS_WRITE_FIXED_DIMS, TSTOP);
+        VRFY((hrc == SUCCESS), "do_fclose failed");
 
-    if (!param.h5_write_only) {
-        /*
-         * Read performance measurement
-         */
-        /* Need barrier to make sure everyone is done writing and has
-         * closed the file.  Also to make sure everyone starts reading
-         * at the same time.
-         */
-        MPI_Barrier(pio_comm_g);
+        if (!param.h5_write_only) {
+            /*
+             * Read performance measurement
+             */
+            /* Need barrier to make sure everyone is done writing and has
+             * closed the file.  Also to make sure everyone starts reading
+             * at the same time.
+             */
+            MPI_Barrier(pio_comm_g);
 
-        /* Open file for read */
-        io_time_set(res.timers, HDF5_GROSS_READ_FIXED_DIMS, TSTART);
-        hrc = do_fopen(&param, fname, &fd, PIO_READ);
+            /* Open file for read */
+            io_time_set(res.timers, HDF5_GROSS_READ_FIXED_DIMS, TSTART);
+            hrc = do_fopen(&param, fname, &fd, PIO_READ);
 
-        VRFY((hrc == SUCCESS), "do_fopen failed");
+            VRFY((hrc == SUCCESS), "do_fopen failed");
 
-        io_time_set(res.timers, HDF5_FINE_READ_FIXED_DIMS, TSTART);
-        hrc = do_read(&res, &fd, &param, ndsets, nbytes, buf_size, buffer);
-        io_time_set(res.timers, HDF5_FINE_READ_FIXED_DIMS, TSTOP);
-        VRFY((hrc == SUCCESS), "do_read failed");
+            io_time_set(res.timers, HDF5_FINE_READ_FIXED_DIMS, TSTART);
+            hrc = do_read(&res, &fd, &param, ndsets, nbytes, buf_size, buffer);
+            io_time_set(res.timers, HDF5_FINE_READ_FIXED_DIMS, TSTOP);
+            VRFY((hrc == SUCCESS), "do_read failed");
 
-        /* Close file for read */
-        hrc = do_fclose(iot, &fd);
+            /* Close file for read */
+            hrc = do_fclose(iot, &fd);
 
-        io_time_set(res.timers, HDF5_GROSS_READ_FIXED_DIMS, TSTOP);
-        VRFY((hrc == SUCCESS), "do_fclose failed");
-    }
+            io_time_set(res.timers, HDF5_GROSS_READ_FIXED_DIMS, TSTOP);
+            VRFY((hrc == SUCCESS), "do_fclose failed");
+        }
 
-    /* Need barrier to make sure everyone is done with the file */
-    /* before it may be removed by do_cleanupfile */
-    MPI_Barrier(pio_comm_g);
-    do_cleanupfile(iot, fname);
+        /* Need barrier to make sure everyone is done with the file */
+        /* before it may be removed by do_cleanupfile */
+        MPI_Barrier(pio_comm_g);
+        do_cleanupfile(iot, fname);
     }
 
 done:
@@ -378,7 +367,7 @@ done:
     }
 
     /* release generic resources */
-    if(buffer)
+    if (buffer)
         HDfree(buffer);
     res.ret_code = ret_code;
     return res;
@@ -394,12 +383,12 @@ done:
  * Programmer:  Bill Wendling, 21. November 2001
  * Modifications:
  */
-    static char *
+static char *
 pio_create_filename(iotype iot, const char *base_name, char *fullname, size_t size)
 {
     const char *prefix, *suffix = "";
-    char *ptr, last = '\0';
-    size_t i, j;
+    char *      ptr, last       = '\0';
+    size_t      i, j;
 
     if (!base_name || !fullname || size < 1)
         return NULL;
@@ -426,7 +415,7 @@ pio_create_filename(iotype iot, const char *base_name, char *fullname, size_t si
 #ifdef HDF5_PARAPREFIX
     if (!prefix)
         prefix = HDF5_PARAPREFIX;
-#endif  /* HDF5_PARAPREFIX */
+#endif /* HDF5_PARAPREFIX */
 
     /* Prepend the prefix value to the base name */
     if (prefix && *prefix) {
@@ -435,12 +424,12 @@ pio_create_filename(iotype iot, const char *base_name, char *fullname, size_t si
          * directory instead. */
         register char *user, *login, *subdir;
 
-        user = HDgetenv("USER");
-        login = HDgetenv("LOGIN");
+        user   = HDgetenv("USER");
+        login  = HDgetenv("LOGIN");
         subdir = (user ? user : login);
 
         if (subdir) {
-            for (i = 0; i < size-1 && prefix[i]; i++)
+            for (i = 0; i < size - 1 && prefix[i]; i++)
                 fullname[i] = prefix[i];
 
             fullname[i++] = '/';
@@ -461,7 +450,7 @@ pio_create_filename(iotype iot, const char *base_name, char *fullname, size_t si
 
             if (HDstat(fullname, &buf) < 0)
                 /* The directory doesn't exist just yet */
-                if (HDmkdir(fullname, (mode_t) 0755) < 0 && errno != EEXIST) {
+                if (HDmkdir(fullname, (mode_t)0755) < 0 && errno != EEXIST) {
                     /* We couldn't make the "/tmp/${USER,LOGIN}" subdirectory.
                      * Default to PREFIX's original prefix value. */
                     HDstrcpy(fullname, prefix);
@@ -510,62 +499,62 @@ pio_create_filename(iotype iot, const char *base_name, char *fullname, size_t si
  * Modifications:
  *  Added 2D testing (Christian Chilan, 10. August 2005)
  */
-    static herr_t
-do_write(results *res, file_descr *fd, parameters *parms, long ndsets,
-    off_t nbytes, size_t buf_size, void *buffer)
+static herr_t
+do_write(results *res, file_descr *fd, parameters *parms, long ndsets, off_t nbytes, size_t buf_size,
+         void *buffer)
 {
-    int         ret_code = SUCCESS;
-    int         rc;             /*routine return code                   */
-    long        ndset;
-    size_t      blk_size;       /* The block size to subdivide the xfer buffer into */
-    off_t       nbytes_xfer;    /* Total number of bytes transferred so far */
-    size_t      nbytes_xfer_advance; /* Number of bytes transferred in a single I/O operation */
-    size_t      nbytes_toxfer;  /* Number of bytes to transfer a particular time */
-    char        dname[64];
-    off_t       dset_offset=0;  /*dataset offset in a file              */
-    off_t       bytes_begin[2];    /*first elmt this process transfer      */
-    off_t       bytes_count;    /*number of elmts this process transfer */
-    off_t       snbytes=0;  /*size of a side of the dataset square  */
-    unsigned char *buf_p;       /* Current buffer pointer               */
+    int            ret_code = SUCCESS;
+    int            rc; /*routine return code                   */
+    long           ndset;
+    size_t         blk_size;            /* The block size to subdivide the xfer buffer into */
+    off_t          nbytes_xfer;         /* Total number of bytes transferred so far */
+    size_t         nbytes_xfer_advance; /* Number of bytes transferred in a single I/O operation */
+    size_t         nbytes_toxfer;       /* Number of bytes to transfer a particular time */
+    char           dname[64];
+    off_t          dset_offset = 0; /*dataset offset in a file              */
+    off_t          bytes_begin[2];  /*first elmt this process transfer      */
+    off_t          bytes_count;     /*number of elmts this process transfer */
+    off_t          snbytes = 0;     /*size of a side of the dataset square  */
+    unsigned char *buf_p;           /* Current buffer pointer               */
 
     /* POSIX variables */
-    off_t       file_offset;    /* File offset of the next transfer     */
-    off_t       file_offset_advance;    /* File offset advance after each I/O operation */
-    off_t       posix_file_offset;    /* Base file offset of the next transfer      */
+    off_t file_offset;         /* File offset of the next transfer     */
+    off_t file_offset_advance; /* File offset advance after each I/O operation */
+    off_t posix_file_offset;   /* Base file offset of the next transfer      */
 
     /* MPI variables */
-    MPI_Offset  mpi_file_offset;    /* Base file offset of the next transfer*/
-    MPI_Offset  mpi_offset;         /* Offset in MPI file                   */
-    MPI_Offset  mpi_offset_advance; /* Offset advance after each I/O operation */
-    MPI_Datatype mpi_file_type;     /* MPI derived type for 1D file            */
-    MPI_Datatype mpi_blk_type;      /* MPI derived type for 1D buffer          */
-    MPI_Datatype mpi_cont_type;     /* MPI derived type for 2D contiguous file */
-    MPI_Datatype mpi_partial_buffer_cont;       /* MPI derived type for partial 2D contiguous buffer */
-    MPI_Datatype mpi_inter_type;    /* MPI derived type for 2D interleaved file  */
-    MPI_Datatype mpi_partial_buffer_inter;      /* MPI derived type for partial 2D interleaved buffer */
-    MPI_Datatype mpi_full_buffer;       /* MPI derived type for 2D full buffer */
-    MPI_Datatype mpi_full_chunk;        /* MPI derived type for 2D full chunk */
-    MPI_Datatype mpi_chunk_inter_type;  /* MPI derived type for 2D chunk interleaved file */
-    MPI_Datatype mpi_collective_type;   /* Generic MPI derived type for 2D collective access */
-    MPI_Status  mpi_status;
-    int         mrc;                /* MPI return code                      */
+    MPI_Offset   mpi_file_offset;          /* Base file offset of the next transfer*/
+    MPI_Offset   mpi_offset;               /* Offset in MPI file                   */
+    MPI_Offset   mpi_offset_advance;       /* Offset advance after each I/O operation */
+    MPI_Datatype mpi_file_type;            /* MPI derived type for 1D file            */
+    MPI_Datatype mpi_blk_type;             /* MPI derived type for 1D buffer          */
+    MPI_Datatype mpi_cont_type;            /* MPI derived type for 2D contiguous file */
+    MPI_Datatype mpi_partial_buffer_cont;  /* MPI derived type for partial 2D contiguous buffer */
+    MPI_Datatype mpi_inter_type;           /* MPI derived type for 2D interleaved file  */
+    MPI_Datatype mpi_partial_buffer_inter; /* MPI derived type for partial 2D interleaved buffer */
+    MPI_Datatype mpi_full_buffer;          /* MPI derived type for 2D full buffer */
+    MPI_Datatype mpi_full_chunk;           /* MPI derived type for 2D full chunk */
+    MPI_Datatype mpi_chunk_inter_type;     /* MPI derived type for 2D chunk interleaved file */
+    MPI_Datatype mpi_collective_type;      /* Generic MPI derived type for 2D collective access */
+    MPI_Status   mpi_status;
+    int          mrc; /* MPI return code                      */
 
     /* HDF5 variables */
-    herr_t      hrc;                    /*HDF5 return code              */
-    hsize_t     h5dims[2];              /*dataset dim sizes             */
-    hid_t       h5dset_space_id = H5I_INVALID_HID;   /*dataset space ID              */
-    hid_t       h5mem_space_id = H5I_INVALID_HID;    /*memory dataspace ID           */
-    hid_t       h5ds_id = H5I_INVALID_HID;           /*dataset handle                */
-    hsize_t     h5block[2];     /*dataspace selection           */
-    hsize_t     h5stride[2];
-    hsize_t     h5count[2];
-    hsize_t     h5start[2];
-    hssize_t    h5offset[2];            /* Selection offset within dataspace */
-    hid_t       h5dcpl = H5I_INVALID_HID;            /* Dataset creation property list */
-    hid_t       h5dxpl = H5I_INVALID_HID;            /* Dataset transfer property list */
+    herr_t   hrc;                               /*HDF5 return code              */
+    hsize_t  h5dims[2];                         /*dataset dim sizes             */
+    hid_t    h5dset_space_id = H5I_INVALID_HID; /*dataset space ID              */
+    hid_t    h5mem_space_id  = H5I_INVALID_HID; /*memory dataspace ID           */
+    hid_t    h5ds_id         = H5I_INVALID_HID; /*dataset handle                */
+    hsize_t  h5block[2];                        /*dataspace selection           */
+    hsize_t  h5stride[2];
+    hsize_t  h5count[2];
+    hsize_t  h5start[2];
+    hssize_t h5offset[2];              /* Selection offset within dataspace */
+    hid_t    h5dcpl = H5I_INVALID_HID; /* Dataset creation property list */
+    hid_t    h5dxpl = H5I_INVALID_HID; /* Dataset transfer property list */
 
     /* Get the parameters from the parameter block */
-    blk_size=parms->blk_size;
+    blk_size = parms->blk_size;
 
     /* There are two kinds of transfer patterns, contiguous and interleaved.
      * Let 0,1,2,...,n be data accessed by process 0,1,2,...,n
@@ -578,20 +567,20 @@ do_write(results *res, file_descr *fd, parameters *parms, long ndsets,
      */
 
     /* 1D dataspace */
-    if (!parms->dim2d){
+    if (!parms->dim2d) {
         /* Contiguous Pattern: */
         if (!parms->interleaved) {
-            bytes_begin[0] = (off_t)(((double)nbytes*pio_mpi_rank_g)/pio_mpi_nprocs_g);
+            bytes_begin[0] = (off_t)(((double)nbytes * pio_mpi_rank_g) / pio_mpi_nprocs_g);
         } /* end if */
         /* Interleaved Pattern: */
         else {
-            bytes_begin[0] = (off_t)(blk_size*(size_t)pio_mpi_rank_g);
+            bytes_begin[0] = (off_t)(blk_size * (size_t)pio_mpi_rank_g);
         } /* end else */
 
         /* Prepare buffer for verifying data */
         if (parms->verify)
-            memset(buffer,pio_mpi_rank_g+1,buf_size);
-    }/* end if */
+            memset(buffer, pio_mpi_rank_g + 1, buf_size);
+    } /* end if */
     /* 2D dataspace */
     else {
         /* nbytes is always the number of bytes per dataset (1D or 2D). If the
@@ -601,25 +590,24 @@ do_write(results *res, file_descr *fd, parameters *parms, long ndsets,
 
         /* Contiguous Pattern: */
         if (!parms->interleaved) {
-            bytes_begin[0] = (off_t)((double)snbytes*pio_mpi_rank_g / pio_mpi_nprocs_g);
+            bytes_begin[0] = (off_t)((double)snbytes * pio_mpi_rank_g / pio_mpi_nprocs_g);
             bytes_begin[1] = 0;
         } /* end if */
         /* Interleaved Pattern: */
         else {
             bytes_begin[0] = 0;
 
-            if(!parms->h5_use_chunks || parms->io_type==PHDF5)
-                bytes_begin[1] = (off_t)(blk_size*(size_t)pio_mpi_rank_g);
+            if (!parms->h5_use_chunks || parms->io_type == PHDF5)
+                bytes_begin[1] = (off_t)(blk_size * (size_t)pio_mpi_rank_g);
             else
-                bytes_begin[1] = (off_t)(blk_size*blk_size*(size_t)pio_mpi_rank_g);
+                bytes_begin[1] = (off_t)(blk_size * blk_size * (size_t)pio_mpi_rank_g);
         } /* end else */
 
         /* Prepare buffer for verifying data */
         if (parms->verify)
-            HDmemset(buffer,pio_mpi_rank_g+1,buf_size*blk_size);
+            HDmemset(buffer, pio_mpi_rank_g + 1, buf_size * blk_size);
     } /* end else */
 
-
     /* Calculate the total number of bytes (bytes_count) to be
      * transferred by this process. It may be different for different
      * transfer pattern due to rounding to integral values.
@@ -630,861 +618,887 @@ do_write(results *res, file_descr *fd, parameters *parms, long ndsets,
      * This way, it eliminates any rounding errors.
      * (This is tricky, don't mess with the formula, rounding errors
      * can easily get introduced) */
-    bytes_count = (off_t)(((double)nbytes*(pio_mpi_rank_g+1)) / pio_mpi_nprocs_g)
-    - (off_t)(((double)nbytes*pio_mpi_rank_g) / pio_mpi_nprocs_g);
+    bytes_count = (off_t)(((double)nbytes * (pio_mpi_rank_g + 1)) / pio_mpi_nprocs_g) -
+                  (off_t)(((double)nbytes * pio_mpi_rank_g) / pio_mpi_nprocs_g);
 
     /* debug */
     if (pio_debug_level >= 4) {
         HDprint_rank(output);
         if (!parms->dim2d) {
-        HDfprintf(output, "Debug(do_write): "
-            "buf_size=%zu, bytes_begin=%" H5_PRINTF_LL_WIDTH "d, bytes_count=%" H5_PRINTF_LL_WIDTH "d\n",
-            buf_size, (long long)bytes_begin[0],
-            (long long)bytes_count);
-        } else {
-        HDfprintf(output, "Debug(do_write): "
-            "linear buf_size=%zu, bytes_begin=(%" H5_PRINTF_LL_WIDTH "d,%" H5_PRINTF_LL_WIDTH "d), bytes_count=%" H5_PRINTF_LL_WIDTH "d\n",
-            buf_size*blk_size, (long long)bytes_begin[0],
-            (long long)bytes_begin[1], (long long)bytes_count);
+            HDfprintf(output,
+                      "Debug(do_write): "
+                      "buf_size=%zu, bytes_begin=%" H5_PRINTF_LL_WIDTH "d, bytes_count=%" H5_PRINTF_LL_WIDTH
+                      "d\n",
+                      buf_size, (long long)bytes_begin[0], (long long)bytes_count);
+        }
+        else {
+            HDfprintf(output,
+                      "Debug(do_write): "
+                      "linear buf_size=%zu, bytes_begin=(%" H5_PRINTF_LL_WIDTH "d,%" H5_PRINTF_LL_WIDTH
+                      "d), bytes_count=%" H5_PRINTF_LL_WIDTH "d\n",
+                      buf_size * blk_size, (long long)bytes_begin[0], (long long)bytes_begin[1],
+                      (long long)bytes_count);
         }
     }
 
     /* I/O Access specific setup */
     switch (parms->io_type) {
-    case POSIXIO:
-        /* No extra setup */
-        break;
-
-    case MPIO: /* MPI-I/O setup */
-        /* 1D dataspace */
-        if (!parms->dim2d){
-            /* Build block's derived type */
-            mrc = MPI_Type_contiguous((int)blk_size,
-                MPI_BYTE, &mpi_blk_type);
-            VRFY((mrc==MPI_SUCCESS), "MPIO_TYPE_CREATE");
-
-            /* Build file's derived type */
-            mrc = MPI_Type_vector((int)(buf_size/blk_size), (int)1,
-                (int)pio_mpi_nprocs_g, mpi_blk_type, &mpi_file_type);
-            VRFY((mrc==MPI_SUCCESS), "MPIO_TYPE_CREATE");
-
-            /* Commit file type */
-            mrc = MPI_Type_commit( &mpi_file_type );
-            VRFY((mrc==MPI_SUCCESS), "MPIO_TYPE_COMMIT");
-
-            /* Commit buffer type */
-            mrc = MPI_Type_commit( &mpi_blk_type );
-            VRFY((mrc==MPI_SUCCESS), "MPIO_TYPE_COMMIT");
-        } /* end if */
-        /* 2D dataspace */
-        else {
-            /* Build partial buffer derived type for contiguous access */
-
-            mrc = MPI_Type_contiguous((int)buf_size, MPI_BYTE,
-                &mpi_partial_buffer_cont);
-            VRFY((mrc==MPI_SUCCESS), "MPIO_TYPE_CREATE");
-
-            /* Commit partial buffer derived type */
-            mrc = MPI_Type_commit(&mpi_partial_buffer_cont);
-            VRFY((mrc==MPI_SUCCESS), "MPIO_TYPE_COMMIT");
-
-            /* Build contiguous file's derived type */
-            mrc = MPI_Type_vector((int)blk_size, (int)1, (int)((size_t)snbytes/buf_size),
-                mpi_partial_buffer_cont, &mpi_cont_type);
-            VRFY((mrc==MPI_SUCCESS), "MPIO_TYPE_CREATE");
-
-            /* Commit contiguous file type */
-            mrc = MPI_Type_commit(&mpi_cont_type);
-            VRFY((mrc==MPI_SUCCESS), "MPIO_TYPE_COMMIT");
-
-            /* Build partial buffer derived type for interleaved access */
-            mrc = MPI_Type_contiguous((int)blk_size, MPI_BYTE,
-                &mpi_partial_buffer_inter);
-            VRFY((mrc==MPI_SUCCESS), "MPIO_TYPE_CREATE");
-
-            /* Commit partial buffer derived type */
-            mrc = MPI_Type_commit(&mpi_partial_buffer_inter);
-            VRFY((mrc==MPI_SUCCESS), "MPIO_TYPE_COMMIT");
-
-            /* Build interleaved file's derived type */
-            mrc = MPI_Type_vector((int)buf_size, (int)1, (int)((size_t)snbytes/blk_size),
-                mpi_partial_buffer_inter, &mpi_inter_type);
-            VRFY((mrc==MPI_SUCCESS), "MPIO_TYPE_CREATE");
-
-            /* Commit interleaved file type */
-            mrc = MPI_Type_commit(&mpi_inter_type);
-            VRFY((mrc==MPI_SUCCESS), "MPIO_TYPE_COMMIT");
-
-            /* Build full buffer derived type */
-            mrc = MPI_Type_contiguous((int)(blk_size*buf_size), MPI_BYTE,
-                &mpi_full_buffer);
-            VRFY((mrc==MPI_SUCCESS), "MPIO_TYPE_CREATE");
-
-            /* Commit full buffer derived type */
-            mrc = MPI_Type_commit(&mpi_full_buffer);
-            VRFY((mrc==MPI_SUCCESS), "MPIO_TYPE_COMMIT");
-
-            /* Build full chunk derived type */
-            mrc = MPI_Type_contiguous((int)(blk_size*blk_size), MPI_BYTE,
-                &mpi_full_chunk);
-            VRFY((mrc==MPI_SUCCESS), "MPIO_TYPE_CREATE");
-
-            /* Commit full chunk derived type */
-            mrc = MPI_Type_commit(&mpi_full_chunk);
-            VRFY((mrc==MPI_SUCCESS), "MPIO_TYPE_COMMIT");
-
-            /* Build chunk interleaved file's derived type */
-            mrc = MPI_Type_vector((int)(buf_size/blk_size), (int)1, (int)((size_t)snbytes/blk_size),
-                mpi_full_chunk, &mpi_chunk_inter_type);
-            VRFY((mrc==MPI_SUCCESS), "MPIO_TYPE_CREATE");
-
-            /* Commit chunk interleaved file type */
-            mrc = MPI_Type_commit(&mpi_chunk_inter_type);
-            VRFY((mrc==MPI_SUCCESS), "MPIO_TYPE_COMMIT");
-
-        } /* end else */
-        break;
-
-    case PHDF5: /* HDF5 setup */
-        /* 1D dataspace */
-        if (!parms->dim2d){
-            if(nbytes>0) {
-                /* define a contiguous dataset of nbytes native bytes */
-                h5dims[0] = (hsize_t)nbytes;
-                h5dset_space_id = H5Screate_simple(1, h5dims, NULL);
-                VRFY((h5dset_space_id >= 0), "H5Screate_simple");
-
-                /* Set up the file dset space id to select the pattern to access */
-                if (!parms->interleaved){
-                /* Contiguous pattern */
-                h5start[0] = (hsize_t)bytes_begin[0];
-                h5stride[0] = h5block[0] = blk_size;
-                h5count[0] = buf_size/blk_size;
-                } /* end if */
-                else {
-                /* Interleaved access pattern */
-                /* Skip offset over blocks of other processes */
-                h5start[0] = (hsize_t)bytes_begin[0];
-                h5stride[0] = blk_size*(size_t)pio_mpi_nprocs_g;
-                h5block[0] = blk_size;
-                h5count[0] = buf_size/blk_size;
-                } /* end else */
-                hrc = H5Sselect_hyperslab(h5dset_space_id, H5S_SELECT_SET,
-                    h5start, h5stride, h5count, h5block);
-                VRFY((hrc >= 0), "H5Sselect_hyperslab");
-            } /* end if */
-            else {
-                h5dset_space_id = H5Screate(H5S_SCALAR);
-                VRFY((h5dset_space_id >= 0), "H5Screate");
-            } /* end else */
-
-            /* Create the memory dataspace that corresponds to the xfer buffer */
-            if(buf_size>0) {
-                h5dims[0] = buf_size;
-                h5mem_space_id = H5Screate_simple(1, h5dims, NULL);
-                VRFY((h5mem_space_id >= 0), "H5Screate_simple");
-            } /* end if */
-            else {
-                h5mem_space_id = H5Screate(H5S_SCALAR);
-                VRFY((h5mem_space_id >= 0), "H5Screate");
-            } /* end else */
-        } /* end if */
-        /* 2D dataspace */
-        else {
-            if(nbytes>0) {
-                /* define a contiguous dataset of nbytes native bytes */
-                h5dims[0] = (hsize_t)snbytes;
-                h5dims[1] = (hsize_t)snbytes;
-                h5dset_space_id = H5Screate_simple(2, h5dims, NULL);
-                VRFY((h5dset_space_id >= 0), "H5Screate_simple");
-
-                /* Set up the file dset space id to select the pattern to access */
-                if (!parms->interleaved){
-                /* Contiguous pattern */
-                h5start[0] = (hsize_t)bytes_begin[0];
-                h5start[1] = (hsize_t)bytes_begin[1];
-                h5stride[0] = 1;
-                h5stride[1] = h5block[0] = h5block[1] = blk_size;
-                h5count[0] = 1;
-                h5count[1] = buf_size/blk_size;
-                } /* end if */
-                else {
-                /* Interleaved access pattern */
-                /* Skip offset over blocks of other processes */
-                h5start[0] = (hsize_t)bytes_begin[0];
-                h5start[1] = (hsize_t)bytes_begin[1];
-                h5stride[0] = blk_size;
-                h5stride[1] = blk_size*(size_t)pio_mpi_nprocs_g;
-                h5block[0] = h5block[1] = blk_size;
-                h5count[0] = buf_size/blk_size;
-                h5count[1] = 1;
-                } /* end else */
-                hrc = H5Sselect_hyperslab(h5dset_space_id, H5S_SELECT_SET,
-                    h5start, h5stride, h5count, h5block);
-                VRFY((hrc >= 0), "H5Sselect_hyperslab");
-            } /* end if */
-            else {
-                h5dset_space_id = H5Screate(H5S_SCALAR);
-                VRFY((h5dset_space_id >= 0), "H5Screate");
-            } /* end else */
+        case POSIXIO:
+            /* No extra setup */
+            break;
 
-            /* Create the memory dataspace that corresponds to the xfer buffer */
-            if(buf_size>0) {
-                if (!parms->interleaved){
-                h5dims[0] = blk_size;
-                h5dims[1] = buf_size;
-                }else{
-                h5dims[0] = buf_size;
-                h5dims[1] = blk_size;
-                }
-                h5mem_space_id = H5Screate_simple(2, h5dims, NULL);
-                VRFY((h5mem_space_id >= 0), "H5Screate_simple");
+        case MPIO: /* MPI-I/O setup */
+            /* 1D dataspace */
+            if (!parms->dim2d) {
+                /* Build block's derived type */
+                mrc = MPI_Type_contiguous((int)blk_size, MPI_BYTE, &mpi_blk_type);
+                VRFY((mrc == MPI_SUCCESS), "MPIO_TYPE_CREATE");
+
+                /* Build file's derived type */
+                mrc = MPI_Type_vector((int)(buf_size / blk_size), (int)1, (int)pio_mpi_nprocs_g, mpi_blk_type,
+                                      &mpi_file_type);
+                VRFY((mrc == MPI_SUCCESS), "MPIO_TYPE_CREATE");
+
+                /* Commit file type */
+                mrc = MPI_Type_commit(&mpi_file_type);
+                VRFY((mrc == MPI_SUCCESS), "MPIO_TYPE_COMMIT");
+
+                /* Commit buffer type */
+                mrc = MPI_Type_commit(&mpi_blk_type);
+                VRFY((mrc == MPI_SUCCESS), "MPIO_TYPE_COMMIT");
             } /* end if */
+            /* 2D dataspace */
             else {
-                h5mem_space_id = H5Screate(H5S_SCALAR);
-                VRFY((h5mem_space_id >= 0), "H5Screate");
-            } /* end else */
-        } /* end else */
+                /* Build partial buffer derived type for contiguous access */
 
-        /* Create the dataset transfer property list */
-        h5dxpl = H5Pcreate(H5P_DATASET_XFER);
-        if (h5dxpl < 0) {
-        HDfprintf(stderr, "HDF5 Property List Create failed\n");
-        GOTOERROR(FAIL);
-        }
+                mrc = MPI_Type_contiguous((int)buf_size, MPI_BYTE, &mpi_partial_buffer_cont);
+                VRFY((mrc == MPI_SUCCESS), "MPIO_TYPE_CREATE");
 
-        /* Change to collective I/O, if asked */
-        if(parms->collective) {
-            hrc = H5Pset_dxpl_mpio(h5dxpl, H5FD_MPIO_COLLECTIVE);
-            if (hrc < 0) {
-                HDfprintf(stderr, "HDF5 Property List Set failed\n");
-                GOTOERROR(FAIL);
-            } /* end if */
-        } /* end if */
-        break;
-
-    default:
-        break;
-    } /* end switch */
+                /* Commit partial buffer derived type */
+                mrc = MPI_Type_commit(&mpi_partial_buffer_cont);
+                VRFY((mrc == MPI_SUCCESS), "MPIO_TYPE_COMMIT");
 
-    for (ndset = 1; ndset <= ndsets; ++ndset) {
+                /* Build contiguous file's derived type */
+                mrc = MPI_Type_vector((int)blk_size, (int)1, (int)((size_t)snbytes / buf_size),
+                                      mpi_partial_buffer_cont, &mpi_cont_type);
+                VRFY((mrc == MPI_SUCCESS), "MPIO_TYPE_CREATE");
 
-    /* Calculate dataset offset within a file */
+                /* Commit contiguous file type */
+                mrc = MPI_Type_commit(&mpi_cont_type);
+                VRFY((mrc == MPI_SUCCESS), "MPIO_TYPE_COMMIT");
 
-    /* create dataset */
-    switch (parms->io_type) {
-        case POSIXIO:
-        case MPIO:
-            /* both posix and mpi io just need dataset offset in file*/
-            dset_offset = (ndset - 1) * nbytes;
-            break;
+                /* Build partial buffer derived type for interleaved access */
+                mrc = MPI_Type_contiguous((int)blk_size, MPI_BYTE, &mpi_partial_buffer_inter);
+                VRFY((mrc == MPI_SUCCESS), "MPIO_TYPE_CREATE");
 
-        case PHDF5:
-            h5dcpl = H5Pcreate(H5P_DATASET_CREATE);
-            if (h5dcpl < 0) {
-                HDfprintf(stderr, "HDF5 Property List Create failed\n");
-                GOTOERROR(FAIL);
-            }
-            /* 1D dataspace */
-            if (!parms->dim2d){
-                /* Make the dataset chunked if asked */
-                if(parms->h5_use_chunks) {
-                /* Set the chunk size to be the same as the buffer size */
-                h5dims[0] = blk_size;
-                hrc = H5Pset_chunk(h5dcpl, 1, h5dims);
-                if (hrc < 0) {
-                    HDfprintf(stderr, "HDF5 Property List Set failed\n");
-                    GOTOERROR(FAIL);
-                } /* end if */
-                } /* end if */
-            }/* end if */
-            else{
-                /* 2D dataspace */
-                if(parms->h5_use_chunks) {
-                /* Set the chunk size to be the same as the block size */
-                h5dims[0] = blk_size;
-                h5dims[1] = blk_size;
-                hrc = H5Pset_chunk(h5dcpl, 2, h5dims);
-                if (hrc < 0) {
-                    HDfprintf(stderr, "HDF5 Property List Set failed\n");
-                    GOTOERROR(FAIL);
-                } /* end if */
-                } /* end if */
-            }/* end else */
+                /* Commit partial buffer derived type */
+                mrc = MPI_Type_commit(&mpi_partial_buffer_inter);
+                VRFY((mrc == MPI_SUCCESS), "MPIO_TYPE_COMMIT");
 
-            HDsprintf(dname, "Dataset_%ld", ndset);
-            h5ds_id = H5DCREATE(fd->h5fd, dname, ELMT_H5_TYPE,
-                h5dset_space_id, h5dcpl);
+                /* Build interleaved file's derived type */
+                mrc = MPI_Type_vector((int)buf_size, (int)1, (int)((size_t)snbytes / blk_size),
+                                      mpi_partial_buffer_inter, &mpi_inter_type);
+                VRFY((mrc == MPI_SUCCESS), "MPIO_TYPE_CREATE");
 
-            if (h5ds_id < 0) {
-                HDfprintf(stderr, "HDF5 Dataset Create failed\n");
-                GOTOERROR(FAIL);
-            }
+                /* Commit interleaved file type */
+                mrc = MPI_Type_commit(&mpi_inter_type);
+                VRFY((mrc == MPI_SUCCESS), "MPIO_TYPE_COMMIT");
 
-            hrc = H5Pclose(h5dcpl);
-            /* verifying the close of the dcpl */
-            if (hrc < 0) {
-                HDfprintf(stderr, "HDF5 Property List Close failed\n");
-                GOTOERROR(FAIL);
-            }
-            break;
+                /* Build full buffer derived type */
+                mrc = MPI_Type_contiguous((int)(blk_size * buf_size), MPI_BYTE, &mpi_full_buffer);
+                VRFY((mrc == MPI_SUCCESS), "MPIO_TYPE_CREATE");
 
-        default:
-            break;
-    }
+                /* Commit full buffer derived type */
+                mrc = MPI_Type_commit(&mpi_full_buffer);
+                VRFY((mrc == MPI_SUCCESS), "MPIO_TYPE_COMMIT");
 
-    /* The task is to transfer bytes_count bytes, starting at
-     * bytes_begin position, using transfer buffer of buf_size bytes.
-     * If interleaved, select buf_size at a time, in round robin
-     * fashion, according to number of process. Otherwise, select
-     * all bytes_count in contiguous.
-     */
-    nbytes_xfer = 0 ;
+                /* Build full chunk derived type */
+                mrc = MPI_Type_contiguous((int)(blk_size * blk_size), MPI_BYTE, &mpi_full_chunk);
+                VRFY((mrc == MPI_SUCCESS), "MPIO_TYPE_CREATE");
 
-    /* 1D dataspace */
-    if (!parms->dim2d){
-        /* Set base file offset for all I/O patterns and POSIX access */
-        posix_file_offset = dset_offset + bytes_begin[0];
+                /* Commit full chunk derived type */
+                mrc = MPI_Type_commit(&mpi_full_chunk);
+                VRFY((mrc == MPI_SUCCESS), "MPIO_TYPE_COMMIT");
 
-        /* Set base file offset for all I/O patterns and MPI access */
-        mpi_file_offset = (MPI_Offset)(dset_offset + bytes_begin[0]);
-    } /* end if */
-    else {
-        /* Set base file offset for all I/O patterns and POSIX access */
-        posix_file_offset=dset_offset + bytes_begin[0]*snbytes+
-        bytes_begin[1];
+                /* Build chunk interleaved file's derived type */
+                mrc = MPI_Type_vector((int)(buf_size / blk_size), (int)1, (int)((size_t)snbytes / blk_size),
+                                      mpi_full_chunk, &mpi_chunk_inter_type);
+                VRFY((mrc == MPI_SUCCESS), "MPIO_TYPE_CREATE");
 
-        /* Set base file offset for all I/O patterns and MPI access */
-        mpi_file_offset=(MPI_Offset)(dset_offset + bytes_begin[0]*snbytes+
-            bytes_begin[1]);
-    } /* end else */
+                /* Commit chunk interleaved file type */
+                mrc = MPI_Type_commit(&mpi_chunk_inter_type);
+                VRFY((mrc == MPI_SUCCESS), "MPIO_TYPE_COMMIT");
 
-    /* Start "raw data" write timer */
-    io_time_set(res->timers, HDF5_RAW_WRITE_FIXED_DIMS, TSTART);
+            } /* end else */
+            break;
 
-    while (nbytes_xfer < bytes_count){
-        /* Write */
-        /* Calculate offset of write within a dataset/file */
-        switch (parms->io_type) {
-        case POSIXIO:
+        case PHDF5: /* HDF5 setup */
             /* 1D dataspace */
-            if (!parms->dim2d){
-                /* Contiguous pattern */
-                if (!parms->interleaved) {
-                    /* Compute file offset */
-                    file_offset = posix_file_offset + (off_t)nbytes_xfer;
-
-                    /* only care if seek returns error */
-                    rc = POSIXSEEK(fd->posixfd, file_offset) < 0 ? -1 : 0;
-                    VRFY((rc==0), "POSIXSEEK");
-
-                    /* check if all bytes are written */
-                    rc = ((ssize_t)buf_size ==
-                        POSIXWRITE(fd->posixfd, buffer, buf_size));
-                    VRFY((rc != 0), "POSIXWRITE");
-
-                    /* Advance global offset in dataset */
-                    nbytes_xfer+=(ssize_t)buf_size;
+            if (!parms->dim2d) {
+                if (nbytes > 0) {
+                    /* define a contiguous dataset of nbytes native bytes */
+                    h5dims[0]       = (hsize_t)nbytes;
+                    h5dset_space_id = H5Screate_simple(1, h5dims, NULL);
+                    VRFY((h5dset_space_id >= 0), "H5Screate_simple");
+
+                    /* Set up the file dset space id to select the pattern to access */
+                    if (!parms->interleaved) {
+                        /* Contiguous pattern */
+                        h5start[0]  = (hsize_t)bytes_begin[0];
+                        h5stride[0] = h5block[0] = blk_size;
+                        h5count[0]               = buf_size / blk_size;
+                    } /* end if */
+                    else {
+                        /* Interleaved access pattern */
+                        /* Skip offset over blocks of other processes */
+                        h5start[0]  = (hsize_t)bytes_begin[0];
+                        h5stride[0] = blk_size * (size_t)pio_mpi_nprocs_g;
+                        h5block[0]  = blk_size;
+                        h5count[0]  = buf_size / blk_size;
+                    } /* end else */
+                    hrc = H5Sselect_hyperslab(h5dset_space_id, H5S_SELECT_SET, h5start, h5stride, h5count,
+                                              h5block);
+                    VRFY((hrc >= 0), "H5Sselect_hyperslab");
                 } /* end if */
-                /* Interleaved access pattern */
                 else {
-                    /* Set the base of user's buffer */
-                    buf_p=(unsigned char *)buffer;
-
-                    /* Set the number of bytes to transfer this time */
-                    nbytes_toxfer = buf_size;
-
-                    /* Loop over the buffers to write */
-                    while(nbytes_toxfer>0) {
-                        /* Skip offset over blocks of other processes */
-                        file_offset = posix_file_offset +
-                            (off_t)(nbytes_xfer*pio_mpi_nprocs_g);
-
-                        /* only care if seek returns error */
-                        rc = POSIXSEEK(fd->posixfd, file_offset) < 0 ? -1 : 0;
-                        VRFY((rc==0), "POSIXSEEK");
-
-                        /* check if all bytes are written */
-                        rc = ((ssize_t)blk_size ==
-                            POSIXWRITE(fd->posixfd, buf_p, blk_size));
-                        VRFY((rc != 0), "POSIXWRITE");
-
-                        /* Advance location in buffer */
-                        buf_p+=blk_size;
-
-                        /* Advance global offset in dataset */
-                        nbytes_xfer+=(ssize_t)blk_size;
+                    h5dset_space_id = H5Screate(H5S_SCALAR);
+                    VRFY((h5dset_space_id >= 0), "H5Screate");
+                } /* end else */
 
-                        /* Decrement number of bytes left this time */
-                        nbytes_toxfer-=blk_size;
-                    } /* end while */
+                /* Create the memory dataspace that corresponds to the xfer buffer */
+                if (buf_size > 0) {
+                    h5dims[0]      = buf_size;
+                    h5mem_space_id = H5Screate_simple(1, h5dims, NULL);
+                    VRFY((h5mem_space_id >= 0), "H5Screate_simple");
+                } /* end if */
+                else {
+                    h5mem_space_id = H5Screate(H5S_SCALAR);
+                    VRFY((h5mem_space_id >= 0), "H5Screate");
                 } /* end else */
-            } /* end if */
+            }     /* end if */
             /* 2D dataspace */
             else {
-                /* Contiguous storage */
-                if (!parms->h5_use_chunks) {
-                    /* Contiguous access pattern */
+                if (nbytes > 0) {
+                    /* define a contiguous dataset of nbytes native bytes */
+                    h5dims[0]       = (hsize_t)snbytes;
+                    h5dims[1]       = (hsize_t)snbytes;
+                    h5dset_space_id = H5Screate_simple(2, h5dims, NULL);
+                    VRFY((h5dset_space_id >= 0), "H5Screate_simple");
+
+                    /* Set up the file dset space id to select the pattern to access */
                     if (!parms->interleaved) {
-                        /* Compute file offset */
-                        file_offset=posix_file_offset+(off_t)((((size_t)nbytes_xfer/blk_size)
-                            /(size_t)snbytes)*(blk_size*(size_t)snbytes)+(((size_t)nbytes_xfer/blk_size)%(size_t)snbytes));
-
-                        /* Number of bytes to be transferred per I/O operation */
-                        nbytes_xfer_advance = buf_size;
-
-                        /* Global offset advance after each I/O operation */
-                        file_offset_advance = (off_t)snbytes;
+                        /* Contiguous pattern */
+                        h5start[0]  = (hsize_t)bytes_begin[0];
+                        h5start[1]  = (hsize_t)bytes_begin[1];
+                        h5stride[0] = 1;
+                        h5stride[1] = h5block[0] = h5block[1] = blk_size;
+                        h5count[0]                            = 1;
+                        h5count[1]                            = buf_size / blk_size;
                     } /* end if */
-                    /* Interleaved access pattern */
                     else {
-                        /* Compute file offset */
-                        file_offset=posix_file_offset+(off_t)(((((size_t)nbytes_xfer/buf_size)
-                            *(size_t)pio_mpi_nprocs_g)/(size_t)snbytes)*(buf_size*(size_t)snbytes)
-                            +(((size_t)nbytes_xfer/buf_size)*(size_t)pio_mpi_nprocs_g)%(size_t)snbytes);
-
-                        /* Number of bytes to be transferred per I/O operation */
-                        nbytes_xfer_advance = blk_size;
-
-                        /* Global offset advance after each I/O operation */
-                        file_offset_advance = (off_t)snbytes;
+                        /* Interleaved access pattern */
+                        /* Skip offset over blocks of other processes */
+                        h5start[0]  = (hsize_t)bytes_begin[0];
+                        h5start[1]  = (hsize_t)bytes_begin[1];
+                        h5stride[0] = blk_size;
+                        h5stride[1] = blk_size * (size_t)pio_mpi_nprocs_g;
+                        h5block[0] = h5block[1] = blk_size;
+                        h5count[0]              = buf_size / blk_size;
+                        h5count[1]              = 1;
                     } /* end else */
+                    hrc = H5Sselect_hyperslab(h5dset_space_id, H5S_SELECT_SET, h5start, h5stride, h5count,
+                                              h5block);
+                    VRFY((hrc >= 0), "H5Sselect_hyperslab");
                 } /* end if */
-                /* Chunked storage */
                 else {
-                    /*Contiguous access pattern */
-                    if (!parms->interleaved) {
-                        /* Compute file offset */
-                        file_offset=posix_file_offset+(off_t)nbytes_xfer;
-
-                        /* Number of bytes to be transferred per I/O operation */
-                        nbytes_xfer_advance = blk_size * buf_size;
+                    h5dset_space_id = H5Screate(H5S_SCALAR);
+                    VRFY((h5dset_space_id >= 0), "H5Screate");
+                } /* end else */
 
-                        /* Global offset advance after each I/O operation */
-                        file_offset_advance = 0;
-                    } /* end if */
-                    /*Interleaved access pattern */
+                /* Create the memory dataspace that corresponds to the xfer buffer */
+                if (buf_size > 0) {
+                    if (!parms->interleaved) {
+                        h5dims[0] = blk_size;
+                        h5dims[1] = buf_size;
+                    }
                     else {
-                        /* Compute file offset */
-                        /* Before simplification */
-                        /* file_offset=posix_file_offset+(off_t)((nbytes_xfer/(buf_size/blk_size)
-                        *pio_mpi_nprocs_g)/(snbytes/blk_size*(blk_size*blk_size))*(buf_size/blk_size
-                        *snbytes/blk_size*(blk_size*blk_size))+((nbytes_xfer/(buf_size/blk_size))
-                        *pio_mpi_nprocs_g)%(snbytes/blk_size*(blk_size*blk_size))); */
-
-                        file_offset=posix_file_offset+(off_t)((((size_t)nbytes_xfer/(buf_size/blk_size)
-                        *(size_t)pio_mpi_nprocs_g)/((size_t)snbytes*blk_size))*(buf_size*(size_t)snbytes)+(((size_t)nbytes_xfer/(buf_size/blk_size))
-                        *(size_t)pio_mpi_nprocs_g)%((size_t)snbytes*blk_size));
-
-                        /* Number of bytes to be transferred per I/O operation */
-                        nbytes_xfer_advance = blk_size * blk_size;
-
-                        /* Global offset advance after each I/O operation */
-                        /* file_offset_advance = (off_t)(snbytes/blk_size*(blk_size*blk_size)); */
-                        file_offset_advance = (off_t)snbytes*(off_t)blk_size;
-                    } /* end else */
+                        h5dims[0] = buf_size;
+                        h5dims[1] = blk_size;
+                    }
+                    h5mem_space_id = H5Screate_simple(2, h5dims, NULL);
+                    VRFY((h5mem_space_id >= 0), "H5Screate_simple");
+                } /* end if */
+                else {
+                    h5mem_space_id = H5Screate(H5S_SCALAR);
+                    VRFY((h5mem_space_id >= 0), "H5Screate");
                 } /* end else */
+            }     /* end else */
+
+            /* Create the dataset transfer property list */
+            h5dxpl = H5Pcreate(H5P_DATASET_XFER);
+            if (h5dxpl < 0) {
+                HDfprintf(stderr, "HDF5 Property List Create failed\n");
+                GOTOERROR(FAIL);
+            }
 
-                /* Common code for file access */
+            /* Change to collective I/O, if asked */
+            if (parms->collective) {
+                hrc = H5Pset_dxpl_mpio(h5dxpl, H5FD_MPIO_COLLECTIVE);
+                if (hrc < 0) {
+                    HDfprintf(stderr, "HDF5 Property List Set failed\n");
+                    GOTOERROR(FAIL);
+                } /* end if */
+            }     /* end if */
+            break;
 
-                /* Set the base of user's buffer */
-                buf_p = (unsigned char *)buffer;
+        default:
+            break;
+    } /* end switch */
 
-                /* Set the number of bytes to transfer this time */
-                nbytes_toxfer = buf_size*blk_size;
+    for (ndset = 1; ndset <= ndsets; ++ndset) {
 
-                /* Loop over portions of the buffer to write */
-                while(nbytes_toxfer>0){
-                    /* only care if seek returns error */
-                    rc = POSIXSEEK(fd->posixfd, file_offset) < 0 ? -1 : 0;
-                    VRFY((rc==0), "POSIXSEEK");
+        /* Calculate dataset offset within a file */
 
-                    /* check if all bytes are written */
-                    rc = ((ssize_t)nbytes_xfer_advance ==
-                        POSIXWRITE(fd->posixfd, buf_p, nbytes_xfer_advance));
-                    VRFY((rc != 0), "POSIXWRITE");
+        /* create dataset */
+        switch (parms->io_type) {
+            case POSIXIO:
+            case MPIO:
+                /* both posix and mpi io just need dataset offset in file*/
+                dset_offset = (ndset - 1) * nbytes;
+                break;
 
-                    /* Advance location in buffer */
-                    buf_p+=nbytes_xfer_advance;
+            case PHDF5:
+                h5dcpl = H5Pcreate(H5P_DATASET_CREATE);
+                if (h5dcpl < 0) {
+                    HDfprintf(stderr, "HDF5 Property List Create failed\n");
+                    GOTOERROR(FAIL);
+                }
+                /* 1D dataspace */
+                if (!parms->dim2d) {
+                    /* Make the dataset chunked if asked */
+                    if (parms->h5_use_chunks) {
+                        /* Set the chunk size to be the same as the buffer size */
+                        h5dims[0] = blk_size;
+                        hrc       = H5Pset_chunk(h5dcpl, 1, h5dims);
+                        if (hrc < 0) {
+                            HDfprintf(stderr, "HDF5 Property List Set failed\n");
+                            GOTOERROR(FAIL);
+                        } /* end if */
+                    }     /* end if */
+                }         /* end if */
+                else {
+                    /* 2D dataspace */
+                    if (parms->h5_use_chunks) {
+                        /* Set the chunk size to be the same as the block size */
+                        h5dims[0] = blk_size;
+                        h5dims[1] = blk_size;
+                        hrc       = H5Pset_chunk(h5dcpl, 2, h5dims);
+                        if (hrc < 0) {
+                            HDfprintf(stderr, "HDF5 Property List Set failed\n");
+                            GOTOERROR(FAIL);
+                        } /* end if */
+                    }     /* end if */
+                }         /* end else */
+
+                HDsprintf(dname, "Dataset_%ld", ndset);
+                h5ds_id = H5DCREATE(fd->h5fd, dname, ELMT_H5_TYPE, h5dset_space_id, h5dcpl);
+
+                if (h5ds_id < 0) {
+                    HDfprintf(stderr, "HDF5 Dataset Create failed\n");
+                    GOTOERROR(FAIL);
+                }
 
-                    /* Advance global offset in dataset */
-                    nbytes_xfer+=(ssize_t)nbytes_xfer_advance;
+                hrc = H5Pclose(h5dcpl);
+                /* verifying the close of the dcpl */
+                if (hrc < 0) {
+                    HDfprintf(stderr, "HDF5 Property List Close failed\n");
+                    GOTOERROR(FAIL);
+                }
+                break;
 
-                    /* Decrement number of bytes left this time */
-                    nbytes_toxfer-=nbytes_xfer_advance;
+            default:
+                break;
+        }
 
-                    /* Partially advance file offset */
-                    file_offset+=file_offset_advance;
-                } /* end while */
+        /* The task is to transfer bytes_count bytes, starting at
+         * bytes_begin position, using transfer buffer of buf_size bytes.
+         * If interleaved, select buf_size at a time, in round robin
+         * fashion, according to number of process. Otherwise, select
+         * all bytes_count in contiguous.
+         */
+        nbytes_xfer = 0;
 
-            } /* end else */
+        /* 1D dataspace */
+        if (!parms->dim2d) {
+            /* Set base file offset for all I/O patterns and POSIX access */
+            posix_file_offset = dset_offset + bytes_begin[0];
 
-            break;
+            /* Set base file offset for all I/O patterns and MPI access */
+            mpi_file_offset = (MPI_Offset)(dset_offset + bytes_begin[0]);
+        } /* end if */
+        else {
+            /* Set base file offset for all I/O patterns and POSIX access */
+            posix_file_offset = dset_offset + bytes_begin[0] * snbytes + bytes_begin[1];
 
-        case MPIO:
-            /* 1D dataspace */
-            if (!parms->dim2d){
-                /* Independent file access */
-                if(!parms->collective) {
-                    /* Contiguous pattern */
-                    if (!parms->interleaved){
-                        /* Compute offset in file */
-                        mpi_offset = mpi_file_offset +
-                            nbytes_xfer;
-
-                        /* Perform independent write */
-                        mrc = MPI_File_write_at(fd->mpifd, mpi_offset, buffer,
-                            (int)(buf_size/blk_size), mpi_blk_type,
-                            &mpi_status);
-                        VRFY((mrc==MPI_SUCCESS), "MPIO_WRITE");
-
-                        /* Advance global offset in dataset */
-                        nbytes_xfer+=(ssize_t)buf_size;
-                    } /* end if */
-                    /* Interleaved access pattern */
+            /* Set base file offset for all I/O patterns and MPI access */
+            mpi_file_offset = (MPI_Offset)(dset_offset + bytes_begin[0] * snbytes + bytes_begin[1]);
+        } /* end else */
+
+        /* Start "raw data" write timer */
+        io_time_set(res->timers, HDF5_RAW_WRITE_FIXED_DIMS, TSTART);
+
+        while (nbytes_xfer < bytes_count) {
+            /* Write */
+            /* Calculate offset of write within a dataset/file */
+            switch (parms->io_type) {
+                case POSIXIO:
+                    /* 1D dataspace */
+                    if (!parms->dim2d) {
+                        /* Contiguous pattern */
+                        if (!parms->interleaved) {
+                            /* Compute file offset */
+                            file_offset = posix_file_offset + (off_t)nbytes_xfer;
+
+                            /* only care if seek returns error */
+                            rc = POSIXSEEK(fd->posixfd, file_offset) < 0 ? -1 : 0;
+                            VRFY((rc == 0), "POSIXSEEK");
+
+                            /* check if all bytes are written */
+                            rc = ((ssize_t)buf_size == POSIXWRITE(fd->posixfd, buffer, buf_size));
+                            VRFY((rc != 0), "POSIXWRITE");
+
+                            /* Advance global offset in dataset */
+                            nbytes_xfer += (ssize_t)buf_size;
+                        } /* end if */
+                        /* Interleaved access pattern */
+                        else {
+                            /* Set the base of user's buffer */
+                            buf_p = (unsigned char *)buffer;
+
+                            /* Set the number of bytes to transfer this time */
+                            nbytes_toxfer = buf_size;
+
+                            /* Loop over the buffers to write */
+                            while (nbytes_toxfer > 0) {
+                                /* Skip offset over blocks of other processes */
+                                file_offset = posix_file_offset + (off_t)(nbytes_xfer * pio_mpi_nprocs_g);
+
+                                /* only care if seek returns error */
+                                rc = POSIXSEEK(fd->posixfd, file_offset) < 0 ? -1 : 0;
+                                VRFY((rc == 0), "POSIXSEEK");
+
+                                /* check if all bytes are written */
+                                rc = ((ssize_t)blk_size == POSIXWRITE(fd->posixfd, buf_p, blk_size));
+                                VRFY((rc != 0), "POSIXWRITE");
+
+                                /* Advance location in buffer */
+                                buf_p += blk_size;
+
+                                /* Advance global offset in dataset */
+                                nbytes_xfer += (ssize_t)blk_size;
+
+                                /* Decrement number of bytes left this time */
+                                nbytes_toxfer -= blk_size;
+                            } /* end while */
+                        }     /* end else */
+                    }         /* end if */
+                    /* 2D dataspace */
                     else {
+                        /* Contiguous storage */
+                        if (!parms->h5_use_chunks) {
+                            /* Contiguous access pattern */
+                            if (!parms->interleaved) {
+                                /* Compute file offset */
+                                file_offset = posix_file_offset +
+                                              (off_t)((((size_t)nbytes_xfer / blk_size) / (size_t)snbytes) *
+                                                          (blk_size * (size_t)snbytes) +
+                                                      (((size_t)nbytes_xfer / blk_size) % (size_t)snbytes));
+
+                                /* Number of bytes to be transferred per I/O operation */
+                                nbytes_xfer_advance = buf_size;
+
+                                /* Global offset advance after each I/O operation */
+                                file_offset_advance = (off_t)snbytes;
+                            } /* end if */
+                            /* Interleaved access pattern */
+                            else {
+                                /* Compute file offset */
+                                file_offset =
+                                    posix_file_offset +
+                                    (off_t)(((((size_t)nbytes_xfer / buf_size) * (size_t)pio_mpi_nprocs_g) /
+                                             (size_t)snbytes) *
+                                                (buf_size * (size_t)snbytes) +
+                                            (((size_t)nbytes_xfer / buf_size) * (size_t)pio_mpi_nprocs_g) %
+                                                (size_t)snbytes);
+
+                                /* Number of bytes to be transferred per I/O operation */
+                                nbytes_xfer_advance = blk_size;
+
+                                /* Global offset advance after each I/O operation */
+                                file_offset_advance = (off_t)snbytes;
+                            } /* end else */
+                        }     /* end if */
+                        /* Chunked storage */
+                        else {
+                            /*Contiguous access pattern */
+                            if (!parms->interleaved) {
+                                /* Compute file offset */
+                                file_offset = posix_file_offset + (off_t)nbytes_xfer;
+
+                                /* Number of bytes to be transferred per I/O operation */
+                                nbytes_xfer_advance = blk_size * buf_size;
+
+                                /* Global offset advance after each I/O operation */
+                                file_offset_advance = 0;
+                            } /* end if */
+                            /*Interleaved access pattern */
+                            else {
+                                /* Compute file offset */
+                                /* Before simplification */
+                                /* file_offset=posix_file_offset+(off_t)((nbytes_xfer/(buf_size/blk_size)
+                                 *pio_mpi_nprocs_g)/(snbytes/blk_size*(blk_size*blk_size))*(buf_size/blk_size
+                                 *snbytes/blk_size*(blk_size*blk_size))+((nbytes_xfer/(buf_size/blk_size))
+                                 *pio_mpi_nprocs_g)%(snbytes/blk_size*(blk_size*blk_size))); */
+
+                                file_offset = posix_file_offset +
+                                              (off_t)((((size_t)nbytes_xfer / (buf_size / blk_size) *
+                                                        (size_t)pio_mpi_nprocs_g) /
+                                                       ((size_t)snbytes * blk_size)) *
+                                                          (buf_size * (size_t)snbytes) +
+                                                      (((size_t)nbytes_xfer / (buf_size / blk_size)) *
+                                                       (size_t)pio_mpi_nprocs_g) %
+                                                          ((size_t)snbytes * blk_size));
+
+                                /* Number of bytes to be transferred per I/O operation */
+                                nbytes_xfer_advance = blk_size * blk_size;
+
+                                /* Global offset advance after each I/O operation */
+                                /* file_offset_advance = (off_t)(snbytes/blk_size*(blk_size*blk_size)); */
+                                file_offset_advance = (off_t)snbytes * (off_t)blk_size;
+                            } /* end else */
+                        }     /* end else */
+
+                        /* Common code for file access */
+
                         /* Set the base of user's buffer */
-                        buf_p=(unsigned char *)buffer;
+                        buf_p = (unsigned char *)buffer;
 
                         /* Set the number of bytes to transfer this time */
-                        nbytes_toxfer = buf_size;
+                        nbytes_toxfer = buf_size * blk_size;
 
-                        /* Loop over the buffers to write */
-                        while(nbytes_toxfer>0) {
-                            /* Skip offset over blocks of other processes */
-                            mpi_offset = mpi_file_offset +
-                            (nbytes_xfer*pio_mpi_nprocs_g);
+                        /* Loop over portions of the buffer to write */
+                        while (nbytes_toxfer > 0) {
+                            /* only care if seek returns error */
+                            rc = POSIXSEEK(fd->posixfd, file_offset) < 0 ? -1 : 0;
+                            VRFY((rc == 0), "POSIXSEEK");
 
-                            /* Perform independent write */
-                            mrc = MPI_File_write_at(fd->mpifd, mpi_offset, buf_p,
-                                (int)1, mpi_blk_type, &mpi_status);
-                            VRFY((mrc==MPI_SUCCESS), "MPIO_WRITE");
+                            /* check if all bytes are written */
+                            rc = ((ssize_t)nbytes_xfer_advance ==
+                                  POSIXWRITE(fd->posixfd, buf_p, nbytes_xfer_advance));
+                            VRFY((rc != 0), "POSIXWRITE");
 
                             /* Advance location in buffer */
-                            buf_p+=blk_size;
+                            buf_p += nbytes_xfer_advance;
 
                             /* Advance global offset in dataset */
-                            nbytes_xfer+=(ssize_t)blk_size;
+                            nbytes_xfer += (ssize_t)nbytes_xfer_advance;
 
                             /* Decrement number of bytes left this time */
-                            nbytes_toxfer-=blk_size;
-                        } /* end while */
-                    } /* end else */
-                } /* end if */
-                /* Collective file access */
-                else {
-                    /* Contiguous access pattern */
-                    if (!parms->interleaved){
-                        /* Compute offset in file */
-                        mpi_offset = mpi_file_offset +
-                            nbytes_xfer;
-
-                        /* Perform independent write */
-                        mrc = MPI_File_write_at_all(fd->mpifd, mpi_offset, buffer,
-                            (int)(buf_size/blk_size), mpi_blk_type, &mpi_status);
-                        VRFY((mrc==MPI_SUCCESS), "MPIO_WRITE");
-
-                        /* Advance global offset in dataset */
-                        nbytes_xfer+=(ssize_t)buf_size;
-                    } /* end if */
-                    /* Interleaved access pattern */
-                    else {
-                        /* Compute offset in file */
-                        mpi_offset = mpi_file_offset +
-                            (nbytes_xfer*pio_mpi_nprocs_g);
-
-                        /* Set the file view */
-                        mrc = MPI_File_set_view(fd->mpifd, mpi_offset, mpi_blk_type,
-                            mpi_file_type, (char*)"native",  h5_io_info_g);
-                        VRFY((mrc==MPI_SUCCESS), "MPIO_VIEW");
-
-                        /* Perform write */
-                        mrc = MPI_File_write_at_all(fd->mpifd, 0, buffer,
-                            (int)(buf_size/blk_size), mpi_blk_type, &mpi_status);
-                        VRFY((mrc==MPI_SUCCESS), "MPIO_WRITE");
-
-                        /* Advance global offset in dataset */
-                        nbytes_xfer+=(ssize_t)buf_size;
-                    } /* end else */
-                } /* end else */
-            } /* end if */
-            /* 2D dataspace */
-            else {
-                /* Contiguous storage */
-                if (!parms->h5_use_chunks) {
-                    /* Contiguous access pattern */
-                    if (!parms->interleaved) {
-                        /* Compute offset in file */
-                        mpi_offset=mpi_file_offset+(MPI_Offset)((((size_t)nbytes_xfer/blk_size)/(size_t)snbytes)*
-                            (blk_size*(size_t)snbytes))+(MPI_Offset)(((size_t)nbytes_xfer/blk_size)%(size_t)snbytes);
+                            nbytes_toxfer -= nbytes_xfer_advance;
 
-                        /* Number of bytes to be transferred per I/O operation */
-                        nbytes_xfer_advance = buf_size;
+                            /* Partially advance file offset */
+                            file_offset += file_offset_advance;
+                        } /* end while */
 
-                        /* Global offset advance after each I/O operation */
-                        mpi_offset_advance = snbytes;
+                    } /* end else */
 
-                        /* MPI type to be used for collective access */
-                        mpi_collective_type = mpi_cont_type;
-                    } /* end if */
-                    /* Interleaved access pattern */
+                    break;
+
+                case MPIO:
+                    /* 1D dataspace */
+                    if (!parms->dim2d) {
+                        /* Independent file access */
+                        if (!parms->collective) {
+                            /* Contiguous pattern */
+                            if (!parms->interleaved) {
+                                /* Compute offset in file */
+                                mpi_offset = mpi_file_offset + nbytes_xfer;
+
+                                /* Perform independent write */
+                                mrc =
+                                    MPI_File_write_at(fd->mpifd, mpi_offset, buffer,
+                                                      (int)(buf_size / blk_size), mpi_blk_type, &mpi_status);
+                                VRFY((mrc == MPI_SUCCESS), "MPIO_WRITE");
+
+                                /* Advance global offset in dataset */
+                                nbytes_xfer += (ssize_t)buf_size;
+                            } /* end if */
+                            /* Interleaved access pattern */
+                            else {
+                                /* Set the base of user's buffer */
+                                buf_p = (unsigned char *)buffer;
+
+                                /* Set the number of bytes to transfer this time */
+                                nbytes_toxfer = buf_size;
+
+                                /* Loop over the buffers to write */
+                                while (nbytes_toxfer > 0) {
+                                    /* Skip offset over blocks of other processes */
+                                    mpi_offset = mpi_file_offset + (nbytes_xfer * pio_mpi_nprocs_g);
+
+                                    /* Perform independent write */
+                                    mrc = MPI_File_write_at(fd->mpifd, mpi_offset, buf_p, (int)1,
+                                                            mpi_blk_type, &mpi_status);
+                                    VRFY((mrc == MPI_SUCCESS), "MPIO_WRITE");
+
+                                    /* Advance location in buffer */
+                                    buf_p += blk_size;
+
+                                    /* Advance global offset in dataset */
+                                    nbytes_xfer += (ssize_t)blk_size;
+
+                                    /* Decrement number of bytes left this time */
+                                    nbytes_toxfer -= blk_size;
+                                } /* end while */
+                            }     /* end else */
+                        }         /* end if */
+                        /* Collective file access */
+                        else {
+                            /* Contiguous access pattern */
+                            if (!parms->interleaved) {
+                                /* Compute offset in file */
+                                mpi_offset = mpi_file_offset + nbytes_xfer;
+
+                                /* Perform independent write */
+                                mrc = MPI_File_write_at_all(fd->mpifd, mpi_offset, buffer,
+                                                            (int)(buf_size / blk_size), mpi_blk_type,
+                                                            &mpi_status);
+                                VRFY((mrc == MPI_SUCCESS), "MPIO_WRITE");
+
+                                /* Advance global offset in dataset */
+                                nbytes_xfer += (ssize_t)buf_size;
+                            } /* end if */
+                            /* Interleaved access pattern */
+                            else {
+                                /* Compute offset in file */
+                                mpi_offset = mpi_file_offset + (nbytes_xfer * pio_mpi_nprocs_g);
+
+                                /* Set the file view */
+                                mrc = MPI_File_set_view(fd->mpifd, mpi_offset, mpi_blk_type, mpi_file_type,
+                                                        (char *)"native", h5_io_info_g);
+                                VRFY((mrc == MPI_SUCCESS), "MPIO_VIEW");
+
+                                /* Perform write */
+                                mrc = MPI_File_write_at_all(fd->mpifd, 0, buffer, (int)(buf_size / blk_size),
+                                                            mpi_blk_type, &mpi_status);
+                                VRFY((mrc == MPI_SUCCESS), "MPIO_WRITE");
+
+                                /* Advance global offset in dataset */
+                                nbytes_xfer += (ssize_t)buf_size;
+                            } /* end else */
+                        }     /* end else */
+                    }         /* end if */
+                    /* 2D dataspace */
                     else {
-                        /* Compute offset in file */
-                        mpi_offset=mpi_file_offset+(MPI_Offset)(((((size_t)nbytes_xfer/buf_size)*(size_t)pio_mpi_nprocs_g)/(size_t)snbytes)*
-                            (buf_size*(size_t)snbytes))+(MPI_Offset)((((size_t)nbytes_xfer/buf_size)*(size_t)pio_mpi_nprocs_g)%(size_t)snbytes);
+                        /* Contiguous storage */
+                        if (!parms->h5_use_chunks) {
+                            /* Contiguous access pattern */
+                            if (!parms->interleaved) {
+                                /* Compute offset in file */
+                                mpi_offset =
+                                    mpi_file_offset +
+                                    (MPI_Offset)((((size_t)nbytes_xfer / blk_size) / (size_t)snbytes) *
+                                                 (blk_size * (size_t)snbytes)) +
+                                    (MPI_Offset)(((size_t)nbytes_xfer / blk_size) % (size_t)snbytes);
+
+                                /* Number of bytes to be transferred per I/O operation */
+                                nbytes_xfer_advance = buf_size;
+
+                                /* Global offset advance after each I/O operation */
+                                mpi_offset_advance = snbytes;
+
+                                /* MPI type to be used for collective access */
+                                mpi_collective_type = mpi_cont_type;
+                            } /* end if */
+                            /* Interleaved access pattern */
+                            else {
+                                /* Compute offset in file */
+                                mpi_offset =
+                                    mpi_file_offset +
+                                    (MPI_Offset)(
+                                        ((((size_t)nbytes_xfer / buf_size) * (size_t)pio_mpi_nprocs_g) /
+                                         (size_t)snbytes) *
+                                        (buf_size * (size_t)snbytes)) +
+                                    (MPI_Offset)(
+                                        (((size_t)nbytes_xfer / buf_size) * (size_t)pio_mpi_nprocs_g) %
+                                        (size_t)snbytes);
+
+                                /* Number of bytes to be transferred per I/O operation */
+                                nbytes_xfer_advance = blk_size;
+
+                                /* Global offset advance after each I/O operation */
+                                mpi_offset_advance = snbytes;
+
+                                /* MPI type to be used for collective access */
+                                mpi_collective_type = mpi_inter_type;
+                            } /* end else */
+                        }     /* end if */
+                        /* Chunked storage */
+                        else {
+                            /*Contiguous access pattern */
+                            if (!parms->interleaved) {
+                                /* Compute offset in file */
+                                mpi_offset = mpi_file_offset + nbytes_xfer;
+
+                                /* Number of bytes to be transferred per I/O operation */
+                                nbytes_xfer_advance = blk_size * buf_size;
+
+                                /* Global offset advance after each I/O operation */
+                                mpi_offset_advance = 0;
+
+                                /* MPI type to be used for collective access */
+                                mpi_collective_type = mpi_full_buffer;
+                            } /* end if */
+                            /*Interleaved access pattern */
+                            else {
+                                /* Compute offset in file */
+                                /* Before simplification */
+                                /* mpi_offset=mpi_file_offset+(nbytes_xfer/(buf_size/blk_size)
+                                    *pio_mpi_nprocs_g)/(snbytes/blk_size*(blk_size*blk_size))*
+                                    (buf_size/blk_size*snbytes/blk_size*(blk_size*blk_size))+
+                                    ((nbytes_xfer/(buf_size/blk_size))*pio_mpi_nprocs_g)%(snbytes
+                                    /blk_size*(blk_size*blk_size)); */
+                                mpi_offset = mpi_file_offset +
+                                             (MPI_Offset)((((size_t)nbytes_xfer / (buf_size / blk_size) *
+                                                            (size_t)pio_mpi_nprocs_g) /
+                                                           ((size_t)snbytes * blk_size)) *
+                                                          (buf_size * (size_t)snbytes)) +
+                                             (MPI_Offset)((((size_t)nbytes_xfer / (buf_size / blk_size)) *
+                                                           (size_t)pio_mpi_nprocs_g) %
+                                                          ((size_t)snbytes * blk_size));
+
+                                /* Number of bytes to be transferred per I/O operation */
+                                nbytes_xfer_advance = blk_size * blk_size;
+
+                                /* Global offset advance after each I/O operation */
+                                /* mpi_offset_advance = (MPI_Offset)(snbytes/blk_size*(blk_size*blk_size)); */
+                                mpi_offset_advance = (MPI_Offset)((size_t)snbytes * blk_size);
+
+                                /* MPI type to be used for collective access */
+                                mpi_collective_type = mpi_chunk_inter_type;
+                            } /* end else */
+                        }     /* end else */
+
+                        /* Common code for independent file access */
+                        if (!parms->collective) {
+                            /* Set the base of user's buffer */
+                            buf_p = (unsigned char *)buffer;
+
+                            /* Set the number of bytes to transfer this time */
+                            nbytes_toxfer = buf_size * blk_size;
+
+                            /* Loop over portions of the buffer to write */
+                            while (nbytes_toxfer > 0) {
+                                /* Perform independent write */
+                                mrc = MPI_File_write_at(fd->mpifd, mpi_offset, buf_p,
+                                                        (int)nbytes_xfer_advance, MPI_BYTE, &mpi_status);
+                                VRFY((mrc == MPI_SUCCESS), "MPIO_WRITE");
+
+                                /* Advance location in buffer */
+                                buf_p += nbytes_xfer_advance;
+
+                                /* Advance global offset in dataset */
+                                nbytes_xfer += (ssize_t)nbytes_xfer_advance;
+
+                                /* Decrement number of bytes left this time */
+                                nbytes_toxfer -= nbytes_xfer_advance;
+
+                                /* Partially advance global offset in dataset */
+                                mpi_offset += mpi_offset_advance;
+                            } /* end while */
+                        }     /* end if */
+
+                        /* Common code for collective file access */
+                        else {
+                            /* Set the file view */
+                            mrc = MPI_File_set_view(fd->mpifd, mpi_offset, MPI_BYTE, mpi_collective_type,
+                                                    (char *)"native", h5_io_info_g);
+                            VRFY((mrc == MPI_SUCCESS), "MPIO_VIEW");
+
+                            /* Perform write */
+                            MPI_File_write_at_all(fd->mpifd, 0, buffer, (int)(buf_size * blk_size), MPI_BYTE,
+                                                  &mpi_status);
+                            VRFY((mrc == MPI_SUCCESS), "MPIO_WRITE");
 
-                        /* Number of bytes to be transferred per I/O operation */
-                        nbytes_xfer_advance = blk_size;
-
-                        /* Global offset advance after each I/O operation */
-                        mpi_offset_advance = snbytes;
+                            /* Advance global offset in dataset */
+                            nbytes_xfer += (off_t)buf_size * (off_t)blk_size;
+                        } /* end else */
 
-                        /* MPI type to be used for collective access */
-                        mpi_collective_type = mpi_inter_type;
                     } /* end else */
-                } /* end if */
-                /* Chunked storage */
-                else {
-                    /*Contiguous access pattern */
-                    if (!parms->interleaved) {
-                        /* Compute offset in file */
-                        mpi_offset=mpi_file_offset+nbytes_xfer;
-
-                        /* Number of bytes to be transferred per I/O operation */
-                        nbytes_xfer_advance = blk_size * buf_size;
 
-                        /* Global offset advance after each I/O operation */
-                        mpi_offset_advance = 0;
-
-                        /* MPI type to be used for collective access */
-                        mpi_collective_type = mpi_full_buffer;
+                    break;
+
+                case PHDF5:
+                    /* 1D dataspace */
+                    if (!parms->dim2d) {
+                        /* Set up the file dset space id to move the selection to process */
+                        if (!parms->interleaved) {
+                            /* Contiguous pattern */
+                            h5offset[0] = nbytes_xfer;
+                        } /* end if */
+                        else {
+                            /* Interleaved access pattern */
+                            /* Skip offset over blocks of other processes */
+                            h5offset[0] = (nbytes_xfer * pio_mpi_nprocs_g);
+                        } /* end else */
+                        hrc = H5Soffset_simple(h5dset_space_id, h5offset);
+                        VRFY((hrc >= 0), "H5Soffset_simple");
+
+                        /* Write the buffer out */
+                        hrc =
+                            H5Dwrite(h5ds_id, ELMT_H5_TYPE, h5mem_space_id, h5dset_space_id, h5dxpl, buffer);
+                        VRFY((hrc >= 0), "H5Dwrite");
+
+                        /* Increment number of bytes transferred */
+                        nbytes_xfer += (ssize_t)buf_size;
                     } /* end if */
-                    /*Interleaved access pattern */
+                    /* 2D dataspace */
                     else {
-                        /* Compute offset in file */
-                        /* Before simplification */
-                        /* mpi_offset=mpi_file_offset+(nbytes_xfer/(buf_size/blk_size)
-                            *pio_mpi_nprocs_g)/(snbytes/blk_size*(blk_size*blk_size))*
-                            (buf_size/blk_size*snbytes/blk_size*(blk_size*blk_size))+
-                            ((nbytes_xfer/(buf_size/blk_size))*pio_mpi_nprocs_g)%(snbytes
-                            /blk_size*(blk_size*blk_size)); */
-                        mpi_offset=mpi_file_offset+(MPI_Offset)((((size_t)nbytes_xfer/(buf_size/blk_size)
-                            *(size_t)pio_mpi_nprocs_g)/((size_t)snbytes*blk_size))*(buf_size*(size_t)snbytes))
-                            +(MPI_Offset)((((size_t)nbytes_xfer/(buf_size/blk_size))*(size_t)pio_mpi_nprocs_g)%((size_t)snbytes*blk_size));
-
-                        /* Number of bytes to be transferred per I/O operation */
-                        nbytes_xfer_advance = blk_size * blk_size;
-
-                        /* Global offset advance after each I/O operation */
-                        /* mpi_offset_advance = (MPI_Offset)(snbytes/blk_size*(blk_size*blk_size)); */
-                        mpi_offset_advance = (MPI_Offset)((size_t)snbytes*blk_size);
-
-                        /* MPI type to be used for collective access */
-                        mpi_collective_type = mpi_chunk_inter_type;
-                    } /* end else */
-                } /* end else */
-
-                /* Common code for independent file access */
-                if (!parms->collective) {
-                    /* Set the base of user's buffer */
-                    buf_p = (unsigned char *)buffer;
-
-                    /* Set the number of bytes to transfer this time */
-                    nbytes_toxfer = buf_size * blk_size;
-
-                    /* Loop over portions of the buffer to write */
-                    while(nbytes_toxfer>0){
-                        /* Perform independent write */
-                        mrc = MPI_File_write_at(fd->mpifd, mpi_offset, buf_p,
-                            (int)nbytes_xfer_advance, MPI_BYTE, &mpi_status);
-                        VRFY((mrc==MPI_SUCCESS), "MPIO_WRITE");
-
-                        /* Advance location in buffer */
-                        buf_p+=nbytes_xfer_advance;
-
-                        /* Advance global offset in dataset */
-                        nbytes_xfer+=(ssize_t)nbytes_xfer_advance;
-
-                        /* Decrement number of bytes left this time */
-                        nbytes_toxfer-=nbytes_xfer_advance;
-
-                        /* Partially advance global offset in dataset */
-                        mpi_offset+=mpi_offset_advance;
-                    } /* end while */
-                } /* end if */
-
-                /* Common code for collective file access */
-                else {
-                    /* Set the file view */
-                    mrc = MPI_File_set_view(fd->mpifd, mpi_offset, MPI_BYTE,
-                        mpi_collective_type, (char *)"native", h5_io_info_g);
-                    VRFY((mrc==MPI_SUCCESS), "MPIO_VIEW");
-
-                    /* Perform write */
-                    MPI_File_write_at_all(fd->mpifd, 0, buffer,(int)(buf_size*blk_size),
-                        MPI_BYTE, &mpi_status);
-                    VRFY((mrc==MPI_SUCCESS), "MPIO_WRITE");
-
-                    /* Advance global offset in dataset */
-                    nbytes_xfer+=(off_t)buf_size*(off_t)blk_size;
-                } /* end else */
-
-            } /* end else */
-
-            break;
-
-        case PHDF5:
-            /* 1D dataspace */
-            if (!parms->dim2d){
-            /* Set up the file dset space id to move the selection to process */
-            if (!parms->interleaved){
-                /* Contiguous pattern */
-                h5offset[0] = nbytes_xfer;
-            } /* end if */
-            else {
-                /* Interleaved access pattern */
-                /* Skip offset over blocks of other processes */
-                h5offset[0] = (nbytes_xfer*pio_mpi_nprocs_g);
-            } /* end else */
-            hrc = H5Soffset_simple(h5dset_space_id, h5offset);
-            VRFY((hrc >= 0), "H5Soffset_simple");
-
-            /* Write the buffer out */
-            hrc = H5Dwrite(h5ds_id, ELMT_H5_TYPE, h5mem_space_id,
-                h5dset_space_id, h5dxpl, buffer);
-            VRFY((hrc >= 0), "H5Dwrite");
-
-            /* Increment number of bytes transferred */
-            nbytes_xfer += (ssize_t)buf_size;
-            } /* end if */
-            /* 2D dataspace */
-            else {
-            /* Set up the file dset space id to move the selection to process */
-            if (!parms->interleaved){
-                /* Contiguous pattern */
-                h5offset[0] = (hssize_t)(((size_t)nbytes_xfer/((size_t)snbytes*blk_size))*blk_size);
-                h5offset[1] = (hssize_t)(((size_t)nbytes_xfer%((size_t)snbytes*blk_size))/blk_size);
-
-            } /* end if */
-            else {
-                /* Interleaved access pattern */
-                /* Skip offset over blocks of other processes */
-                h5offset[0] = (hssize_t)((((size_t)nbytes_xfer*(size_t)pio_mpi_nprocs_g)/((size_t)snbytes*buf_size))*buf_size);
-                h5offset[1] = (hssize_t)((((size_t)nbytes_xfer*(size_t)pio_mpi_nprocs_g)%((size_t)snbytes*buf_size))/buf_size);
+                        /* Set up the file dset space id to move the selection to process */
+                        if (!parms->interleaved) {
+                            /* Contiguous pattern */
+                            h5offset[0] =
+                                (hssize_t)(((size_t)nbytes_xfer / ((size_t)snbytes * blk_size)) * blk_size);
+                            h5offset[1] =
+                                (hssize_t)(((size_t)nbytes_xfer % ((size_t)snbytes * blk_size)) / blk_size);
+
+                        } /* end if */
+                        else {
+                            /* Interleaved access pattern */
+                            /* Skip offset over blocks of other processes */
+                            h5offset[0] = (hssize_t)((((size_t)nbytes_xfer * (size_t)pio_mpi_nprocs_g) /
+                                                      ((size_t)snbytes * buf_size)) *
+                                                     buf_size);
+                            h5offset[1] = (hssize_t)((((size_t)nbytes_xfer * (size_t)pio_mpi_nprocs_g) %
+                                                      ((size_t)snbytes * buf_size)) /
+                                                     buf_size);
 
-            } /* end else */
-            hrc = H5Soffset_simple(h5dset_space_id, h5offset);
-            VRFY((hrc >= 0), "H5Soffset_simple");
+                        } /* end else */
+                        hrc = H5Soffset_simple(h5dset_space_id, h5offset);
+                        VRFY((hrc >= 0), "H5Soffset_simple");
 
-            /* Write the buffer out */
-            hrc = H5Dwrite(h5ds_id, ELMT_H5_TYPE, h5mem_space_id,
-                h5dset_space_id, h5dxpl, buffer);
-            VRFY((hrc >= 0), "H5Dwrite");
+                        /* Write the buffer out */
+                        hrc =
+                            H5Dwrite(h5ds_id, ELMT_H5_TYPE, h5mem_space_id, h5dset_space_id, h5dxpl, buffer);
+                        VRFY((hrc >= 0), "H5Dwrite");
 
-            /* Increment number of bytes transferred */
-            nbytes_xfer += (off_t)buf_size*(off_t)blk_size;
+                        /* Increment number of bytes transferred */
+                        nbytes_xfer += (off_t)buf_size * (off_t)blk_size;
 
-            } /* end else */
+                    } /* end else */
 
-            break;
+                    break;
 
-        default:
-            break;
-        } /* switch (parms->io_type) */
-    } /* end while */
+                default:
+                    break;
+            } /* switch (parms->io_type) */
+        }     /* end while */
 
-    /* Stop "raw data" write timer */
-    io_time_set(res->timers, HDF5_RAW_WRITE_FIXED_DIMS, TSTOP);
+        /* Stop "raw data" write timer */
+        io_time_set(res->timers, HDF5_RAW_WRITE_FIXED_DIMS, TSTOP);
 
-    /* Calculate write time */
+        /* Calculate write time */
 
-    /* Close dataset. Only HDF5 needs to do an explicit close. */
-    if (parms->io_type == PHDF5) {
-        hrc = H5Dclose(h5ds_id);
+        /* Close dataset. Only HDF5 needs to do an explicit close. */
+        if (parms->io_type == PHDF5) {
+            hrc = H5Dclose(h5ds_id);
 
-        if (hrc < 0) {
-        HDfprintf(stderr, "HDF5 Dataset Close failed\n");
-        GOTOERROR(FAIL);
-        }
+            if (hrc < 0) {
+                HDfprintf(stderr, "HDF5 Dataset Close failed\n");
+                GOTOERROR(FAIL);
+            }
 
-        h5ds_id = H5I_INVALID_HID;
-    } /* end if */
-    } /* end for */
+            h5ds_id = H5I_INVALID_HID;
+        } /* end if */
+    }     /* end for */
 
 done:
     /* release MPI-I/O objects */
     if (parms->io_type == MPIO) {
         /* 1D dataspace */
-        if (!parms->dim2d){
+        if (!parms->dim2d) {
             /* Free file type */
-            mrc = MPI_Type_free( &mpi_file_type );
-            VRFY((mrc==MPI_SUCCESS), "MPIO_TYPE_FREE");
+            mrc = MPI_Type_free(&mpi_file_type);
+            VRFY((mrc == MPI_SUCCESS), "MPIO_TYPE_FREE");
 
             /* Free buffer type */
-            mrc = MPI_Type_free( &mpi_blk_type );
-            VRFY((mrc==MPI_SUCCESS), "MPIO_TYPE_FREE");
+            mrc = MPI_Type_free(&mpi_blk_type);
+            VRFY((mrc == MPI_SUCCESS), "MPIO_TYPE_FREE");
         } /* end if */
         /* 2D dataspace */
         else {
             /* Free partial buffer type for contiguous access */
-            mrc = MPI_Type_free( &mpi_partial_buffer_cont );
-            VRFY((mrc==MPI_SUCCESS), "MPIO_TYPE_FREE");
+            mrc = MPI_Type_free(&mpi_partial_buffer_cont);
+            VRFY((mrc == MPI_SUCCESS), "MPIO_TYPE_FREE");
 
             /* Free contiguous file type */
-            mrc = MPI_Type_free( &mpi_cont_type );
-            VRFY((mrc==MPI_SUCCESS), "MPIO_TYPE_FREE");
+            mrc = MPI_Type_free(&mpi_cont_type);
+            VRFY((mrc == MPI_SUCCESS), "MPIO_TYPE_FREE");
 
             /* Free partial buffer type for interleaved access */
-            mrc = MPI_Type_free( &mpi_partial_buffer_inter );
-            VRFY((mrc==MPI_SUCCESS), "MPIO_TYPE_FREE");
+            mrc = MPI_Type_free(&mpi_partial_buffer_inter);
+            VRFY((mrc == MPI_SUCCESS), "MPIO_TYPE_FREE");
 
             /* Free interleaved file type */
-            mrc = MPI_Type_free( &mpi_inter_type );
-            VRFY((mrc==MPI_SUCCESS), "MPIO_TYPE_FREE");
+            mrc = MPI_Type_free(&mpi_inter_type);
+            VRFY((mrc == MPI_SUCCESS), "MPIO_TYPE_FREE");
 
             /* Free full buffer type */
             mrc = MPI_Type_free(&mpi_full_buffer);
-            VRFY((mrc==MPI_SUCCESS), "MPIO_TYPE_FREE");
+            VRFY((mrc == MPI_SUCCESS), "MPIO_TYPE_FREE");
 
             /* Free full chunk type */
             mrc = MPI_Type_free(&mpi_full_chunk);
-            VRFY((mrc==MPI_SUCCESS), "MPIO_TYPE_FREE");
+            VRFY((mrc == MPI_SUCCESS), "MPIO_TYPE_FREE");
 
             /* Free chunk interleaved file type */
             mrc = MPI_Type_free(&mpi_chunk_inter_type);
-            VRFY((mrc==MPI_SUCCESS), "MPIO_TYPE_FREE");
+            VRFY((mrc == MPI_SUCCESS), "MPIO_TYPE_FREE");
         } /* end else */
-    } /* end if */
+    }     /* end if */
 
     /* release HDF5 objects */
     if (h5dset_space_id != -1) {
-    hrc = H5Sclose(h5dset_space_id);
-    if (hrc < 0){
-        HDfprintf(stderr, "HDF5 Dataset Space Close failed\n");
-        ret_code = FAIL;
-    } else {
-        h5dset_space_id = H5I_INVALID_HID;
-    }
+        hrc = H5Sclose(h5dset_space_id);
+        if (hrc < 0) {
+            HDfprintf(stderr, "HDF5 Dataset Space Close failed\n");
+            ret_code = FAIL;
+        }
+        else {
+            h5dset_space_id = H5I_INVALID_HID;
+        }
     }
 
     if (h5mem_space_id != -1) {
-    hrc = H5Sclose(h5mem_space_id);
-    if (hrc < 0) {
-        HDfprintf(stderr, "HDF5 Memory Space Close failed\n");
-        ret_code = FAIL;
-    } else {
-        h5mem_space_id = H5I_INVALID_HID;
-    }
+        hrc = H5Sclose(h5mem_space_id);
+        if (hrc < 0) {
+            HDfprintf(stderr, "HDF5 Memory Space Close failed\n");
+            ret_code = FAIL;
+        }
+        else {
+            h5mem_space_id = H5I_INVALID_HID;
+        }
     }
 
     if (h5dxpl != -1) {
-    hrc = H5Pclose(h5dxpl);
-    if (hrc < 0) {
-        HDfprintf(stderr, "HDF5 Dataset Transfer Property List Close failed\n");
-        ret_code = FAIL;
-    } else {
-        h5dxpl = H5I_INVALID_HID;
-    }
+        hrc = H5Pclose(h5dxpl);
+        if (hrc < 0) {
+            HDfprintf(stderr, "HDF5 Dataset Transfer Property List Close failed\n");
+            ret_code = FAIL;
+        }
+        else {
+            h5dxpl = H5I_INVALID_HID;
+        }
     }
 
     return ret_code;
@@ -1505,62 +1519,62 @@ sqrto(off_t x)
  * Modifications:
  *  Added 2D testing (Christian Chilan, 10. August 2005)
  */
-    static herr_t
-do_read(results *res, file_descr *fd, parameters *parms, long ndsets,
-    off_t nbytes, size_t buf_size, void *buffer /*out*/)
+static herr_t
+do_read(results *res, file_descr *fd, parameters *parms, long ndsets, off_t nbytes, size_t buf_size,
+        void *buffer /*out*/)
 {
-    int         ret_code = SUCCESS;
-    int         rc;             /*routine return code                   */
-    long        ndset;
-    size_t      blk_size;       /* The block size to subdivide the xfer buffer into */
-    size_t      bsize;          /* Size of the actual buffer */
-    off_t       nbytes_xfer;    /* Total number of bytes transferred so far */
-    size_t      nbytes_xfer_advance; /* Number of bytes transferred in a single I/O operation */
-    size_t      nbytes_toxfer;  /* Number of bytes to transfer a particular time */
-    char        dname[64];
-    off_t       dset_offset=0;  /*dataset offset in a file              */
-    off_t       bytes_begin[2];    /*first elmt this process transfer      */
-    off_t       bytes_count;    /*number of elmts this process transfer */
-    off_t       snbytes=0;      /*size of a side of the dataset square */
-    unsigned char *buf_p;       /* Current buffer pointer               */
+    int            ret_code = SUCCESS;
+    int            rc; /*routine return code                   */
+    long           ndset;
+    size_t         blk_size;            /* The block size to subdivide the xfer buffer into */
+    size_t         bsize;               /* Size of the actual buffer */
+    off_t          nbytes_xfer;         /* Total number of bytes transferred so far */
+    size_t         nbytes_xfer_advance; /* Number of bytes transferred in a single I/O operation */
+    size_t         nbytes_toxfer;       /* Number of bytes to transfer a particular time */
+    char           dname[64];
+    off_t          dset_offset = 0; /*dataset offset in a file              */
+    off_t          bytes_begin[2];  /*first elmt this process transfer      */
+    off_t          bytes_count;     /*number of elmts this process transfer */
+    off_t          snbytes = 0;     /*size of a side of the dataset square */
+    unsigned char *buf_p;           /* Current buffer pointer               */
 
     /* POSIX variables */
-    off_t       file_offset;    /* File offset of the next transfer    */
-    off_t       file_offset_advance; /* File offset advance after each I/O operation */
-    off_t       posix_file_offset;    /* Base file offset of the next transfer      */
+    off_t file_offset;         /* File offset of the next transfer    */
+    off_t file_offset_advance; /* File offset advance after each I/O operation */
+    off_t posix_file_offset;   /* Base file offset of the next transfer      */
 
     /* MPI variables */
-    MPI_Offset  mpi_file_offset;/* Base file offset of the next transfer*/
-    MPI_Offset  mpi_offset;     /* Offset in MPI file                   */
-    MPI_Offset  mpi_offset_advance; /* Offset advance after each I/O operation */
-    MPI_Datatype mpi_file_type; /* MPI derived type for 1D file            */
-    MPI_Datatype mpi_blk_type;  /* MPI derived type for 1D buffer          */
-    MPI_Datatype mpi_cont_type; /* MPI derived type for 2D contiguous file */
-    MPI_Datatype mpi_partial_buffer_cont;       /* MPI derived type for partial 2D contiguous buffer */
-    MPI_Datatype mpi_inter_type;    /* MPI derived type for 2D interleaved file  */
-    MPI_Datatype mpi_partial_buffer_inter;      /* MPI derived type for partial 2D interleaved buffer */
-    MPI_Datatype mpi_full_buffer;       /* MPI derived type for 2D full buffer */
-    MPI_Datatype mpi_full_chunk;        /* MPI derived type for 2D full chunk */
-    MPI_Datatype mpi_chunk_inter_type;  /* MPI derived type for 2D chunk interleaved file */
-    MPI_Datatype mpi_collective_type;   /* Generic MPI derived type for 2D collective access */
-    MPI_Status  mpi_status;
-    int         mrc;            /* MPI return code                      */
+    MPI_Offset   mpi_file_offset;          /* Base file offset of the next transfer*/
+    MPI_Offset   mpi_offset;               /* Offset in MPI file                   */
+    MPI_Offset   mpi_offset_advance;       /* Offset advance after each I/O operation */
+    MPI_Datatype mpi_file_type;            /* MPI derived type for 1D file            */
+    MPI_Datatype mpi_blk_type;             /* MPI derived type for 1D buffer          */
+    MPI_Datatype mpi_cont_type;            /* MPI derived type for 2D contiguous file */
+    MPI_Datatype mpi_partial_buffer_cont;  /* MPI derived type for partial 2D contiguous buffer */
+    MPI_Datatype mpi_inter_type;           /* MPI derived type for 2D interleaved file  */
+    MPI_Datatype mpi_partial_buffer_inter; /* MPI derived type for partial 2D interleaved buffer */
+    MPI_Datatype mpi_full_buffer;          /* MPI derived type for 2D full buffer */
+    MPI_Datatype mpi_full_chunk;           /* MPI derived type for 2D full chunk */
+    MPI_Datatype mpi_chunk_inter_type;     /* MPI derived type for 2D chunk interleaved file */
+    MPI_Datatype mpi_collective_type;      /* Generic MPI derived type for 2D collective access */
+    MPI_Status   mpi_status;
+    int          mrc; /* MPI return code                      */
 
     /* HDF5 variables */
-    herr_t      hrc;                    /*HDF5 return code              */
-    hsize_t     h5dims[2];              /*dataset dim sizes             */
-    hid_t       h5dset_space_id = H5I_INVALID_HID;   /*dataset space ID              */
-    hid_t       h5mem_space_id = H5I_INVALID_HID;    /*memory dataspace ID           */
-    hid_t       h5ds_id = H5I_INVALID_HID;           /*dataset handle                */
-    hsize_t h5block[2];     /*dataspace selection           */
-    hsize_t h5stride[2];
-    hsize_t h5count[2];
-    hsize_t h5start[2];
-    hssize_t    h5offset[2];            /* Selection offset within dataspace */
-    hid_t       h5dxpl = H5I_INVALID_HID;            /* Dataset transfer property list */
+    herr_t   hrc;                               /*HDF5 return code              */
+    hsize_t  h5dims[2];                         /*dataset dim sizes             */
+    hid_t    h5dset_space_id = H5I_INVALID_HID; /*dataset space ID              */
+    hid_t    h5mem_space_id  = H5I_INVALID_HID; /*memory dataspace ID           */
+    hid_t    h5ds_id         = H5I_INVALID_HID; /*dataset handle                */
+    hsize_t  h5block[2];                        /*dataspace selection           */
+    hsize_t  h5stride[2];
+    hsize_t  h5count[2];
+    hsize_t  h5start[2];
+    hssize_t h5offset[2];              /* Selection offset within dataspace */
+    hid_t    h5dxpl = H5I_INVALID_HID; /* Dataset transfer property list */
 
     /* Get the parameters from the parameter block */
-    blk_size=parms->blk_size;
+    blk_size = parms->blk_size;
 
     /* There are two kinds of transfer patterns, contiguous and interleaved.
      * Let 0,1,2,...,n be data accessed by process 0,1,2,...,n
@@ -1573,17 +1587,17 @@ do_read(results *res, file_descr *fd, parameters *parms, long ndsets,
      */
 
     /* 1D dataspace */
-    if (!parms->dim2d){
+    if (!parms->dim2d) {
         bsize = buf_size;
         /* Contiguous Pattern: */
         if (!parms->interleaved) {
-             bytes_begin[0] = (off_t)(((double)nbytes*pio_mpi_rank_g)/pio_mpi_nprocs_g);
+            bytes_begin[0] = (off_t)(((double)nbytes * pio_mpi_rank_g) / pio_mpi_nprocs_g);
         } /* end if */
         /* Interleaved Pattern: */
         else {
-            bytes_begin[0] = (off_t)blk_size*(off_t)pio_mpi_rank_g;
+            bytes_begin[0] = (off_t)blk_size * (off_t)pio_mpi_rank_g;
         } /* end else */
-    }/* end if */
+    }     /* end if */
     /* 2D dataspace */
     else {
         /* nbytes is always the number of bytes per dataset (1D or 2D). If the
@@ -1595,19 +1609,19 @@ do_read(results *res, file_descr *fd, parameters *parms, long ndsets,
 
         /* Contiguous Pattern: */
         if (!parms->interleaved) {
-            bytes_begin[0] = (off_t)((double)snbytes*pio_mpi_rank_g / pio_mpi_nprocs_g);
+            bytes_begin[0] = (off_t)((double)snbytes * pio_mpi_rank_g / pio_mpi_nprocs_g);
             bytes_begin[1] = 0;
         } /* end if */
         /* Interleaved Pattern: */
         else {
             bytes_begin[0] = 0;
 
-            if (!parms->h5_use_chunks || parms->io_type==PHDF5)
-                bytes_begin[1] = (off_t)blk_size*(off_t)pio_mpi_rank_g;
+            if (!parms->h5_use_chunks || parms->io_type == PHDF5)
+                bytes_begin[1] = (off_t)blk_size * (off_t)pio_mpi_rank_g;
             else
-                bytes_begin[1] = (off_t)blk_size*(off_t)blk_size*(off_t)pio_mpi_rank_g;
+                bytes_begin[1] = (off_t)blk_size * (off_t)blk_size * (off_t)pio_mpi_rank_g;
         } /* end else */
-    } /* end else */
+    }     /* end else */
 
     /* Calculate the total number of bytes (bytes_count) to be
      * transferred by this process. It may be different for different
@@ -1619,842 +1633,865 @@ do_read(results *res, file_descr *fd, parameters *parms, long ndsets,
      * This way, it eliminates any rounding errors.
      * (This is tricky, don't mess with the formula, rounding errors
      * can easily get introduced) */
-    bytes_count = (off_t)(((double)nbytes*(pio_mpi_rank_g+1)) / pio_mpi_nprocs_g)
-    - (off_t)(((double)nbytes*pio_mpi_rank_g) / pio_mpi_nprocs_g);
+    bytes_count = (off_t)(((double)nbytes * (pio_mpi_rank_g + 1)) / pio_mpi_nprocs_g) -
+                  (off_t)(((double)nbytes * pio_mpi_rank_g) / pio_mpi_nprocs_g);
 
     /* debug */
     if (pio_debug_level >= 4) {
         HDprint_rank(output);
         if (!parms->dim2d) {
-        HDfprintf(output, "Debug(do_write): "
-            "buf_size=%zu, bytes_begin=%" H5_PRINTF_LL_WIDTH "d, bytes_count=%" H5_PRINTF_LL_WIDTH "d\n",
-            buf_size, (long long)bytes_begin[0],
-            (long long)bytes_count);
-        } else {
-        HDfprintf(output, "Debug(do_write): "
-            "linear buf_size=%zu, bytes_begin=(%" H5_PRINTF_LL_WIDTH "d,%" H5_PRINTF_LL_WIDTH "d), bytes_count=%" H5_PRINTF_LL_WIDTH "d\n",
-            buf_size*blk_size, (long long)bytes_begin[0],
-            (long long)bytes_begin[1], (long long)bytes_count);
+            HDfprintf(output,
+                      "Debug(do_write): "
+                      "buf_size=%zu, bytes_begin=%" H5_PRINTF_LL_WIDTH "d, bytes_count=%" H5_PRINTF_LL_WIDTH
+                      "d\n",
+                      buf_size, (long long)bytes_begin[0], (long long)bytes_count);
+        }
+        else {
+            HDfprintf(output,
+                      "Debug(do_write): "
+                      "linear buf_size=%zu, bytes_begin=(%" H5_PRINTF_LL_WIDTH "d,%" H5_PRINTF_LL_WIDTH
+                      "d), bytes_count=%" H5_PRINTF_LL_WIDTH "d\n",
+                      buf_size * blk_size, (long long)bytes_begin[0], (long long)bytes_begin[1],
+                      (long long)bytes_count);
         }
     }
 
     /* I/O Access specific setup */
     switch (parms->io_type) {
-    case POSIXIO:
-        /* No extra setup */
-        break;
-
-    case MPIO: /* MPI-I/O setup */
-        /* 1D dataspace */
-        if (!parms->dim2d){
-            /* Build block's derived type */
-            mrc = MPI_Type_contiguous((int)blk_size,
-                MPI_BYTE, &mpi_blk_type);
-            VRFY((mrc==MPI_SUCCESS), "MPIO_TYPE_CREATE");
-
-            /* Build file's derived type */
-            mrc = MPI_Type_vector((int)(buf_size/blk_size), (int)1,
-                (int)pio_mpi_nprocs_g, mpi_blk_type, &mpi_file_type);
-            VRFY((mrc==MPI_SUCCESS), "MPIO_TYPE_CREATE");
-
-            /* Commit file type */
-            mrc = MPI_Type_commit( &mpi_file_type );
-            VRFY((mrc==MPI_SUCCESS), "MPIO_TYPE_COMMIT");
-
-            /* Commit buffer type */
-            mrc = MPI_Type_commit( &mpi_blk_type );
-            VRFY((mrc==MPI_SUCCESS), "MPIO_TYPE_COMMIT");
-        } /* end if */
-        /* 2D dataspace */
-        else {
-            /* Build partial buffer derived type for contiguous access */
-            mrc = MPI_Type_contiguous((int)buf_size, MPI_BYTE,
-                &mpi_partial_buffer_cont);
-            VRFY((mrc==MPI_SUCCESS), "MPIO_TYPE_CREATE");
-
-            /* Commit partial buffer derived type */
-            mrc = MPI_Type_commit(&mpi_partial_buffer_cont);
-            VRFY((mrc==MPI_SUCCESS), "MPIO_TYPE_COMMIT");
-
-            /* Build contiguous file's derived type */
-            mrc = MPI_Type_vector((int)blk_size, (int)1, (int)((size_t)snbytes/buf_size),
-                mpi_partial_buffer_cont, &mpi_cont_type);
-            VRFY((mrc==MPI_SUCCESS), "MPIO_TYPE_CREATE");
-
-            /* Commit contiguous file type */
-            mrc = MPI_Type_commit(&mpi_cont_type);
-            VRFY((mrc==MPI_SUCCESS), "MPIO_TYPE_COMMIT");
-
-            /* Build partial buffer derived type for interleaved access */
-            mrc = MPI_Type_contiguous((int)blk_size, MPI_BYTE,
-                &mpi_partial_buffer_inter);
-            VRFY((mrc==MPI_SUCCESS), "MPIO_TYPE_CREATE");
-
-            /* Commit partial buffer derived type */
-            mrc = MPI_Type_commit(&mpi_partial_buffer_inter);
-            VRFY((mrc==MPI_SUCCESS), "MPIO_TYPE_COMMIT");
-
-            /* Build interleaved file's derived type */
-            mrc = MPI_Type_vector((int)buf_size, (int)1, (int)((size_t)snbytes/blk_size),
-                mpi_partial_buffer_inter, &mpi_inter_type);
-            VRFY((mrc==MPI_SUCCESS), "MPIO_TYPE_CREATE");
-
-            /* Commit interleaved file type */
-            mrc = MPI_Type_commit(&mpi_inter_type);
-            VRFY((mrc==MPI_SUCCESS), "MPIO_TYPE_COMMIT");
-
-            /* Build full buffer derived type */
-            mrc = MPI_Type_contiguous((int)(blk_size*buf_size), MPI_BYTE,
-                &mpi_full_buffer);
-            VRFY((mrc==MPI_SUCCESS), "MPIO_TYPE_CREATE");
-
-            /* Commit full buffer derived type */
-            mrc = MPI_Type_commit(&mpi_full_buffer);
-            VRFY((mrc==MPI_SUCCESS), "MPIO_TYPE_COMMIT");
-
-            /* Build full chunk derived type */
-            mrc = MPI_Type_contiguous((int)(blk_size*blk_size), MPI_BYTE,
-                &mpi_full_chunk);
-            VRFY((mrc==MPI_SUCCESS), "MPIO_TYPE_CREATE");
-
-            /* Commit full chunk derived type */
-            mrc = MPI_Type_commit(&mpi_full_chunk);
-            VRFY((mrc==MPI_SUCCESS), "MPIO_TYPE_COMMIT");
-
-            /* Build chunk interleaved file's derived type */
-            mrc = MPI_Type_vector((int)(buf_size/blk_size), (int)1, (int)((size_t)snbytes/blk_size),
-                mpi_full_chunk, &mpi_chunk_inter_type);
-            VRFY((mrc==MPI_SUCCESS), "MPIO_TYPE_CREATE");
-
-            /* Commit chunk interleaved file type */
-            mrc = MPI_Type_commit(&mpi_chunk_inter_type);
-            VRFY((mrc==MPI_SUCCESS), "MPIO_TYPE_COMMIT");
-        } /* end else */
-        break;
-
-    case PHDF5: /* HDF5 setup */
-        /* 1D dataspace */
-        if (!parms->dim2d){
-        if(nbytes>0) {
-            /* define a contiguous dataset of nbytes native bytes */
-            h5dims[0] = (hsize_t)nbytes;
-            h5dset_space_id = H5Screate_simple(1, h5dims, NULL);
-            VRFY((h5dset_space_id >= 0), "H5Screate_simple");
-
-            /* Set up the file dset space id to select the pattern to access */
-            if (!parms->interleaved){
-            /* Contiguous pattern */
-            h5start[0] = (hsize_t)bytes_begin[0];
-            h5stride[0] = h5block[0] = blk_size;
-            h5count[0] = buf_size/blk_size;
-            } /* end if */
-            else {
-            /* Interleaved access pattern */
-            /* Skip offset over blocks of other processes */
-            h5start[0] = (hsize_t)bytes_begin[0];
-            h5stride[0] = blk_size*(size_t)pio_mpi_nprocs_g;
-            h5block[0] = blk_size;
-            h5count[0] = buf_size/blk_size;
-            } /* end else */
-            hrc = H5Sselect_hyperslab(h5dset_space_id, H5S_SELECT_SET,
-                h5start, h5stride, h5count, h5block);
-            VRFY((hrc >= 0), "H5Sselect_hyperslab");
-        } /* end if */
-        else {
-            h5dset_space_id = H5Screate(H5S_SCALAR);
-            VRFY((h5dset_space_id >= 0), "H5Screate");
-        } /* end else */
+        case POSIXIO:
+            /* No extra setup */
+            break;
 
-        /* Create the memory dataspace that corresponds to the xfer buffer */
-        if(buf_size>0) {
-            h5dims[0] = buf_size;
-            h5mem_space_id = H5Screate_simple(1, h5dims, NULL);
-            VRFY((h5mem_space_id >= 0), "H5Screate_simple");
-        } /* end if */
-        else {
-            h5mem_space_id = H5Screate(H5S_SCALAR);
-            VRFY((h5mem_space_id >= 0), "H5Screate");
-        } /* end else */
-        } /* end if */
-        /* 2D dataspace */
-        else {
-        if(nbytes>0) {
-            /* define a contiguous dataset of nbytes native bytes */
-            h5dims[0] = (hsize_t)snbytes;
-            h5dims[1] = (hsize_t)snbytes;
-            h5dset_space_id = H5Screate_simple(2, h5dims, NULL);
-            VRFY((h5dset_space_id >= 0), "H5Screate_simple");
-
-            /* Set up the file dset space id to select the pattern to access */
-            if (!parms->interleaved){
-            /* Contiguous pattern */
-            h5start[0] = (hsize_t)bytes_begin[0];
-            h5start[1] = (hsize_t)bytes_begin[1];
-            h5stride[0] = 1;
-            h5stride[1] = h5block[0] = h5block[1] = blk_size;
-            h5count[0] = 1;
-            h5count[1] = buf_size/blk_size;
+        case MPIO: /* MPI-I/O setup */
+            /* 1D dataspace */
+            if (!parms->dim2d) {
+                /* Build block's derived type */
+                mrc = MPI_Type_contiguous((int)blk_size, MPI_BYTE, &mpi_blk_type);
+                VRFY((mrc == MPI_SUCCESS), "MPIO_TYPE_CREATE");
+
+                /* Build file's derived type */
+                mrc = MPI_Type_vector((int)(buf_size / blk_size), (int)1, (int)pio_mpi_nprocs_g, mpi_blk_type,
+                                      &mpi_file_type);
+                VRFY((mrc == MPI_SUCCESS), "MPIO_TYPE_CREATE");
+
+                /* Commit file type */
+                mrc = MPI_Type_commit(&mpi_file_type);
+                VRFY((mrc == MPI_SUCCESS), "MPIO_TYPE_COMMIT");
+
+                /* Commit buffer type */
+                mrc = MPI_Type_commit(&mpi_blk_type);
+                VRFY((mrc == MPI_SUCCESS), "MPIO_TYPE_COMMIT");
             } /* end if */
+            /* 2D dataspace */
             else {
-            /* Interleaved access pattern */
-            /* Skip offset over blocks of other processes */
-            h5start[0] = (hsize_t)bytes_begin[0];
-            h5start[1] = (hsize_t)bytes_begin[1];
-            h5stride[0] = blk_size;
-            h5stride[1] = blk_size*(size_t)pio_mpi_nprocs_g;
-            h5block[0] = h5block[1] = blk_size;
-            h5count[0] = buf_size/blk_size;
-            h5count[1] = 1;
+                /* Build partial buffer derived type for contiguous access */
+                mrc = MPI_Type_contiguous((int)buf_size, MPI_BYTE, &mpi_partial_buffer_cont);
+                VRFY((mrc == MPI_SUCCESS), "MPIO_TYPE_CREATE");
+
+                /* Commit partial buffer derived type */
+                mrc = MPI_Type_commit(&mpi_partial_buffer_cont);
+                VRFY((mrc == MPI_SUCCESS), "MPIO_TYPE_COMMIT");
+
+                /* Build contiguous file's derived type */
+                mrc = MPI_Type_vector((int)blk_size, (int)1, (int)((size_t)snbytes / buf_size),
+                                      mpi_partial_buffer_cont, &mpi_cont_type);
+                VRFY((mrc == MPI_SUCCESS), "MPIO_TYPE_CREATE");
+
+                /* Commit contiguous file type */
+                mrc = MPI_Type_commit(&mpi_cont_type);
+                VRFY((mrc == MPI_SUCCESS), "MPIO_TYPE_COMMIT");
+
+                /* Build partial buffer derived type for interleaved access */
+                mrc = MPI_Type_contiguous((int)blk_size, MPI_BYTE, &mpi_partial_buffer_inter);
+                VRFY((mrc == MPI_SUCCESS), "MPIO_TYPE_CREATE");
+
+                /* Commit partial buffer derived type */
+                mrc = MPI_Type_commit(&mpi_partial_buffer_inter);
+                VRFY((mrc == MPI_SUCCESS), "MPIO_TYPE_COMMIT");
+
+                /* Build interleaved file's derived type */
+                mrc = MPI_Type_vector((int)buf_size, (int)1, (int)((size_t)snbytes / blk_size),
+                                      mpi_partial_buffer_inter, &mpi_inter_type);
+                VRFY((mrc == MPI_SUCCESS), "MPIO_TYPE_CREATE");
+
+                /* Commit interleaved file type */
+                mrc = MPI_Type_commit(&mpi_inter_type);
+                VRFY((mrc == MPI_SUCCESS), "MPIO_TYPE_COMMIT");
+
+                /* Build full buffer derived type */
+                mrc = MPI_Type_contiguous((int)(blk_size * buf_size), MPI_BYTE, &mpi_full_buffer);
+                VRFY((mrc == MPI_SUCCESS), "MPIO_TYPE_CREATE");
+
+                /* Commit full buffer derived type */
+                mrc = MPI_Type_commit(&mpi_full_buffer);
+                VRFY((mrc == MPI_SUCCESS), "MPIO_TYPE_COMMIT");
+
+                /* Build full chunk derived type */
+                mrc = MPI_Type_contiguous((int)(blk_size * blk_size), MPI_BYTE, &mpi_full_chunk);
+                VRFY((mrc == MPI_SUCCESS), "MPIO_TYPE_CREATE");
+
+                /* Commit full chunk derived type */
+                mrc = MPI_Type_commit(&mpi_full_chunk);
+                VRFY((mrc == MPI_SUCCESS), "MPIO_TYPE_COMMIT");
+
+                /* Build chunk interleaved file's derived type */
+                mrc = MPI_Type_vector((int)(buf_size / blk_size), (int)1, (int)((size_t)snbytes / blk_size),
+                                      mpi_full_chunk, &mpi_chunk_inter_type);
+                VRFY((mrc == MPI_SUCCESS), "MPIO_TYPE_CREATE");
+
+                /* Commit chunk interleaved file type */
+                mrc = MPI_Type_commit(&mpi_chunk_inter_type);
+                VRFY((mrc == MPI_SUCCESS), "MPIO_TYPE_COMMIT");
             } /* end else */
-            hrc = H5Sselect_hyperslab(h5dset_space_id, H5S_SELECT_SET,
-                h5start, h5stride, h5count, h5block);
-            VRFY((hrc >= 0), "H5Sselect_hyperslab");
-        } /* end if */
-        else {
-            h5dset_space_id = H5Screate(H5S_SCALAR);
-            VRFY((h5dset_space_id >= 0), "H5Screate");
-        } /* end else */
-
-        /* Create the memory dataspace that corresponds to the xfer buffer */
-        if(buf_size>0) {
-            if (!parms->interleaved){
-            h5dims[0] = blk_size;
-            h5dims[1] = buf_size;
-            }else{
-            h5dims[0] = buf_size;
-            h5dims[1] = blk_size;
-            }
-            h5mem_space_id = H5Screate_simple(2, h5dims, NULL);
-            VRFY((h5mem_space_id >= 0), "H5Screate_simple");
-        } /* end if */
-        else {
-            h5mem_space_id = H5Screate(H5S_SCALAR);
-            VRFY((h5mem_space_id >= 0), "H5Screate");
-        } /* end else */
-        } /* end else */
-
-        /* Create the dataset transfer property list */
-        h5dxpl = H5Pcreate(H5P_DATASET_XFER);
-        if (h5dxpl < 0) {
-            HDfprintf(stderr, "HDF5 Property List Create failed\n");
-            GOTOERROR(FAIL);
-        }
-
-        /* Change to collective I/O, if asked */
-        if(parms->collective) {
-            hrc = H5Pset_dxpl_mpio(h5dxpl, H5FD_MPIO_COLLECTIVE);
-            if (hrc < 0) {
-                HDfprintf(stderr, "HDF5 Property List Set failed\n");
-                GOTOERROR(FAIL);
-            } /* end if */
-        } /* end if */
-        break;
-
-    default:
-        break;
-    } /* end switch */
-
-    for (ndset = 1; ndset <= ndsets; ++ndset) {
-
-    /* Calculate dataset offset within a file */
-
-    /* create dataset */
-    switch (parms->io_type) {
-        case POSIXIO:
-        case MPIO:
-            /* both posix and mpi io just need dataset offset in file*/
-            dset_offset = (ndset - 1) * nbytes;
             break;
 
-        case PHDF5:
-            HDsprintf(dname, "Dataset_%ld", ndset);
-            h5ds_id = H5DOPEN(fd->h5fd, dname);
-            if (h5ds_id < 0) {
-                HDfprintf(stderr, "HDF5 Dataset open failed\n");
-                GOTOERROR(FAIL);
-            }
-            break;
-
-        default:
-            break;
-    }
-
-    /* The task is to transfer bytes_count bytes, starting at
-     * bytes_begin position, using transfer buffer of buf_size bytes.
-     * If interleaved, select buf_size at a time, in round robin
-     * fashion, according to number of process. Otherwise, select
-     * all bytes_count in contiguous.
-     */
-    nbytes_xfer = 0 ;
-
-    /* 1D dataspace */
-    if (!parms->dim2d){
-        /* Set base file offset for all I/O patterns and POSIX access */
-        posix_file_offset = dset_offset + bytes_begin[0];
-
-        /* Set base file offset for all I/O patterns and MPI access */
-        mpi_file_offset = (MPI_Offset)(dset_offset + bytes_begin[0]);
-    } /* end if */
-    else {
-        /* Set base file offset for all I/O patterns and POSIX access */
-        posix_file_offset=dset_offset + bytes_begin[0]*snbytes+
-        bytes_begin[1];
-
-        /* Set base file offset for all I/O patterns and MPI access */
-        mpi_file_offset=(MPI_Offset)(dset_offset + bytes_begin[0]*snbytes+
-            bytes_begin[1]);
-    } /* end else */
-
-    /* Start "raw data" read timer */
-    io_time_set(res->timers, HDF5_RAW_READ_FIXED_DIMS, TSTART);
-
-    while (nbytes_xfer < bytes_count){
-        /* Read */
-        /* Calculate offset of read within a dataset/file */
-        switch (parms->io_type) {
-        case POSIXIO:
+        case PHDF5: /* HDF5 setup */
             /* 1D dataspace */
-            if (!parms->dim2d){
-                /* Contiguous pattern */
-                if (!parms->interleaved) {
-                    /* Compute file offset */
-                    file_offset = posix_file_offset + (off_t)nbytes_xfer;
-
-                    /* only care if seek returns error */
-                    rc = POSIXSEEK(fd->posixfd, file_offset) < 0 ? -1 : 0;
-                    VRFY((rc==0), "POSIXSEEK");
-
-                    /* check if all bytes are read */
-                    rc = ((ssize_t)buf_size ==
-                        POSIXREAD(fd->posixfd, buffer, buf_size));
-                    VRFY((rc != 0), "POSIXREAD");
-
-                    /* Advance global offset in dataset */
-                    nbytes_xfer+=(off_t)buf_size;
+            if (!parms->dim2d) {
+                if (nbytes > 0) {
+                    /* define a contiguous dataset of nbytes native bytes */
+                    h5dims[0]       = (hsize_t)nbytes;
+                    h5dset_space_id = H5Screate_simple(1, h5dims, NULL);
+                    VRFY((h5dset_space_id >= 0), "H5Screate_simple");
+
+                    /* Set up the file dset space id to select the pattern to access */
+                    if (!parms->interleaved) {
+                        /* Contiguous pattern */
+                        h5start[0]  = (hsize_t)bytes_begin[0];
+                        h5stride[0] = h5block[0] = blk_size;
+                        h5count[0]               = buf_size / blk_size;
+                    } /* end if */
+                    else {
+                        /* Interleaved access pattern */
+                        /* Skip offset over blocks of other processes */
+                        h5start[0]  = (hsize_t)bytes_begin[0];
+                        h5stride[0] = blk_size * (size_t)pio_mpi_nprocs_g;
+                        h5block[0]  = blk_size;
+                        h5count[0]  = buf_size / blk_size;
+                    } /* end else */
+                    hrc = H5Sselect_hyperslab(h5dset_space_id, H5S_SELECT_SET, h5start, h5stride, h5count,
+                                              h5block);
+                    VRFY((hrc >= 0), "H5Sselect_hyperslab");
                 } /* end if */
-                /* Interleaved access pattern */
                 else {
-                    /* Set the base of user's buffer */
-                    buf_p=(unsigned char *)buffer;
-
-                    /* Set the number of bytes to transfer this time */
-                    nbytes_toxfer = buf_size;
-
-                    /* Loop over the buffers to read */
-                    while(nbytes_toxfer>0) {
-                    /* Skip offset over blocks of other processes */
-                    file_offset = posix_file_offset +
-                        (off_t)(nbytes_xfer*pio_mpi_nprocs_g);
-
-                    /* only care if seek returns error */
-                    rc = POSIXSEEK(fd->posixfd, file_offset) < 0 ? -1 : 0;
-                    VRFY((rc==0), "POSIXSEEK");
-
-                    /* check if all bytes are read */
-                    rc = ((ssize_t)blk_size ==
-                        POSIXREAD(fd->posixfd, buf_p, blk_size));
-                    VRFY((rc != 0), "POSIXREAD");
-
-                    /* Advance location in buffer */
-                    buf_p+=blk_size;
-
-                    /* Advance global offset in dataset */
-                    nbytes_xfer+=(off_t)blk_size;
+                    h5dset_space_id = H5Screate(H5S_SCALAR);
+                    VRFY((h5dset_space_id >= 0), "H5Screate");
+                } /* end else */
 
-                    /* Decrement number of bytes left this time */
-                    nbytes_toxfer-=blk_size;
-                    } /* end while */
+                /* Create the memory dataspace that corresponds to the xfer buffer */
+                if (buf_size > 0) {
+                    h5dims[0]      = buf_size;
+                    h5mem_space_id = H5Screate_simple(1, h5dims, NULL);
+                    VRFY((h5mem_space_id >= 0), "H5Screate_simple");
+                } /* end if */
+                else {
+                    h5mem_space_id = H5Screate(H5S_SCALAR);
+                    VRFY((h5mem_space_id >= 0), "H5Screate");
                 } /* end else */
-            } /* end if */
+            }     /* end if */
             /* 2D dataspace */
             else {
-                /* Contiguous storage */
-                if (!parms->h5_use_chunks) {
-                    /* Contiguous access pattern */
+                if (nbytes > 0) {
+                    /* define a contiguous dataset of nbytes native bytes */
+                    h5dims[0]       = (hsize_t)snbytes;
+                    h5dims[1]       = (hsize_t)snbytes;
+                    h5dset_space_id = H5Screate_simple(2, h5dims, NULL);
+                    VRFY((h5dset_space_id >= 0), "H5Screate_simple");
+
+                    /* Set up the file dset space id to select the pattern to access */
                     if (!parms->interleaved) {
-                        /* Compute file offset */
-                        file_offset=posix_file_offset+(off_t)((((size_t)nbytes_xfer/blk_size)
-                            /(size_t)snbytes)*(blk_size*(size_t)snbytes)+(((size_t)nbytes_xfer/blk_size)%(size_t)snbytes));
-
-                        /* Number of bytes to be transferred per I/O operation */
-                        nbytes_xfer_advance = buf_size;
-
-                        /* Global offset advance after each I/O operation */
-                        file_offset_advance = (off_t)snbytes;
+                        /* Contiguous pattern */
+                        h5start[0]  = (hsize_t)bytes_begin[0];
+                        h5start[1]  = (hsize_t)bytes_begin[1];
+                        h5stride[0] = 1;
+                        h5stride[1] = h5block[0] = h5block[1] = blk_size;
+                        h5count[0]                            = 1;
+                        h5count[1]                            = buf_size / blk_size;
                     } /* end if */
-                    /* Interleaved access pattern */
                     else {
-                        /* Compute file offset */
-                        file_offset=posix_file_offset+(off_t)(((((size_t)nbytes_xfer/buf_size)
-                            *(size_t)pio_mpi_nprocs_g)/(size_t)snbytes)*(buf_size*(size_t)snbytes)
-                            +(((size_t)nbytes_xfer/buf_size)*(size_t)pio_mpi_nprocs_g)%(size_t)snbytes);
-
-                        /* Number of bytes to be transferred per I/O operation */
-                        nbytes_xfer_advance = blk_size;
-
-                        /* Global offset advance after each I/O operation */
-                        file_offset_advance = (off_t)snbytes;
+                        /* Interleaved access pattern */
+                        /* Skip offset over blocks of other processes */
+                        h5start[0]  = (hsize_t)bytes_begin[0];
+                        h5start[1]  = (hsize_t)bytes_begin[1];
+                        h5stride[0] = blk_size;
+                        h5stride[1] = blk_size * (size_t)pio_mpi_nprocs_g;
+                        h5block[0] = h5block[1] = blk_size;
+                        h5count[0]              = buf_size / blk_size;
+                        h5count[1]              = 1;
                     } /* end else */
+                    hrc = H5Sselect_hyperslab(h5dset_space_id, H5S_SELECT_SET, h5start, h5stride, h5count,
+                                              h5block);
+                    VRFY((hrc >= 0), "H5Sselect_hyperslab");
                 } /* end if */
-                /* Chunked storage */
                 else {
-                    /*Contiguous access pattern */
-                    if (!parms->interleaved) {
-                        /* Compute file offset */
-                        file_offset=posix_file_offset+(off_t)nbytes_xfer;
-
-                        /* Number of bytes to be transferred per I/O operation */
-                        nbytes_xfer_advance = blk_size * buf_size;
+                    h5dset_space_id = H5Screate(H5S_SCALAR);
+                    VRFY((h5dset_space_id >= 0), "H5Screate");
+                } /* end else */
 
-                        /* Global offset advance after each I/O operation */
-                        file_offset_advance = 0;
-                    } /* end if */
-                    /*Interleaved access pattern */
+                /* Create the memory dataspace that corresponds to the xfer buffer */
+                if (buf_size > 0) {
+                    if (!parms->interleaved) {
+                        h5dims[0] = blk_size;
+                        h5dims[1] = buf_size;
+                    }
                     else {
-                        /* Compute file offset */
-                        /* Before simplification */
-                        /* file_offset=posix_file_offset+(off_t)((nbytes_xfer/(buf_size/blk_size)
-                        *pio_mpi_nprocs_g)/(snbytes/blk_size*(blk_size*blk_size))*(buf_size/blk_size
-                        *snbytes/blk_size*(blk_size*blk_size))+((nbytes_xfer/(buf_size/blk_size))
-                        *pio_mpi_nprocs_g)%(snbytes/blk_size*(blk_size*blk_size))); */
-
-                        file_offset=posix_file_offset+(off_t)((((size_t)nbytes_xfer/(buf_size/blk_size)
-                        *(size_t)pio_mpi_nprocs_g)/((size_t)snbytes*blk_size))*(buf_size*(size_t)snbytes)+(((size_t)nbytes_xfer/(buf_size/blk_size))
-                        *(size_t)pio_mpi_nprocs_g)%((size_t)snbytes*blk_size));
-
-                        /* Number of bytes to be transferred per I/O operation */
-                        nbytes_xfer_advance = blk_size * blk_size;
-
-                        /* Global offset advance after each I/O operation */
-                        /* file_offset_advance = (off_t)(snbytes/blk_size*(blk_size*blk_size)); */
-                        file_offset_advance = (off_t)((size_t)snbytes*blk_size);
-                    } /* end else */
+                        h5dims[0] = buf_size;
+                        h5dims[1] = blk_size;
+                    }
+                    h5mem_space_id = H5Screate_simple(2, h5dims, NULL);
+                    VRFY((h5mem_space_id >= 0), "H5Screate_simple");
+                } /* end if */
+                else {
+                    h5mem_space_id = H5Screate(H5S_SCALAR);
+                    VRFY((h5mem_space_id >= 0), "H5Screate");
                 } /* end else */
+            }     /* end else */
+
+            /* Create the dataset transfer property list */
+            h5dxpl = H5Pcreate(H5P_DATASET_XFER);
+            if (h5dxpl < 0) {
+                HDfprintf(stderr, "HDF5 Property List Create failed\n");
+                GOTOERROR(FAIL);
+            }
 
-                /* Common code for file access */
+            /* Change to collective I/O, if asked */
+            if (parms->collective) {
+                hrc = H5Pset_dxpl_mpio(h5dxpl, H5FD_MPIO_COLLECTIVE);
+                if (hrc < 0) {
+                    HDfprintf(stderr, "HDF5 Property List Set failed\n");
+                    GOTOERROR(FAIL);
+                } /* end if */
+            }     /* end if */
+            break;
 
-                /* Set the base of user's buffer */
-                buf_p = (unsigned char *)buffer;
+        default:
+            break;
+    } /* end switch */
 
-                /* Set the number of bytes to transfer this time */
-                nbytes_toxfer = buf_size*blk_size;
+    for (ndset = 1; ndset <= ndsets; ++ndset) {
 
-                /* Loop over portions of the buffer to read */
-                while(nbytes_toxfer>0){
-                    /* only care if seek returns error */
-                    rc = POSIXSEEK(fd->posixfd, file_offset) < 0 ? -1 : 0;
-                    VRFY((rc==0), "POSIXSEEK");
+        /* Calculate dataset offset within a file */
 
-                    /* check if all bytes are read */
-                    rc = ((ssize_t)nbytes_xfer_advance ==
-                        POSIXREAD(fd->posixfd, buf_p, nbytes_xfer_advance));
-                    VRFY((rc != 0), "POSIXREAD");
+        /* create dataset */
+        switch (parms->io_type) {
+            case POSIXIO:
+            case MPIO:
+                /* both posix and mpi io just need dataset offset in file*/
+                dset_offset = (ndset - 1) * nbytes;
+                break;
 
-                    /* Advance location in buffer */
-                    buf_p+=nbytes_xfer_advance;
+            case PHDF5:
+                HDsprintf(dname, "Dataset_%ld", ndset);
+                h5ds_id = H5DOPEN(fd->h5fd, dname);
+                if (h5ds_id < 0) {
+                    HDfprintf(stderr, "HDF5 Dataset open failed\n");
+                    GOTOERROR(FAIL);
+                }
+                break;
 
-                    /* Advance global offset in dataset */
-                    nbytes_xfer+=(off_t)nbytes_xfer_advance;
+            default:
+                break;
+        }
 
-                    /* Decrement number of bytes left this time */
-                    nbytes_toxfer-=nbytes_xfer_advance;
+        /* The task is to transfer bytes_count bytes, starting at
+         * bytes_begin position, using transfer buffer of buf_size bytes.
+         * If interleaved, select buf_size at a time, in round robin
+         * fashion, according to number of process. Otherwise, select
+         * all bytes_count in contiguous.
+         */
+        nbytes_xfer = 0;
 
-                    /* Partially advance file offset */
-                    file_offset+=file_offset_advance;
-                } /* end while */
+        /* 1D dataspace */
+        if (!parms->dim2d) {
+            /* Set base file offset for all I/O patterns and POSIX access */
+            posix_file_offset = dset_offset + bytes_begin[0];
 
-            } /* end else */
-            break;
+            /* Set base file offset for all I/O patterns and MPI access */
+            mpi_file_offset = (MPI_Offset)(dset_offset + bytes_begin[0]);
+        } /* end if */
+        else {
+            /* Set base file offset for all I/O patterns and POSIX access */
+            posix_file_offset = dset_offset + bytes_begin[0] * snbytes + bytes_begin[1];
 
-        case MPIO:
-            /* 1D dataspace */
-            if (!parms->dim2d){
-                /* Independent file access */
-                if(!parms->collective) {
-                    /* Contiguous pattern */
-                    if (!parms->interleaved){
-                        /* Compute offset in file */
-                        mpi_offset = mpi_file_offset +
-                            nbytes_xfer;
-
-                        /* Perform independent read */
-                        mrc = MPI_File_read_at(fd->mpifd, mpi_offset, buffer,
-                            (int)(buf_size/blk_size), mpi_blk_type,
-                            &mpi_status);
-                        VRFY((mrc==MPI_SUCCESS), "MPIO_READ");
-
-                        /* Advance global offset in dataset */
-                        nbytes_xfer+=(off_t)buf_size;
-                    } /* end if */
-                    /* Interleaved access pattern */
+            /* Set base file offset for all I/O patterns and MPI access */
+            mpi_file_offset = (MPI_Offset)(dset_offset + bytes_begin[0] * snbytes + bytes_begin[1]);
+        } /* end else */
+
+        /* Start "raw data" read timer */
+        io_time_set(res->timers, HDF5_RAW_READ_FIXED_DIMS, TSTART);
+
+        while (nbytes_xfer < bytes_count) {
+            /* Read */
+            /* Calculate offset of read within a dataset/file */
+            switch (parms->io_type) {
+                case POSIXIO:
+                    /* 1D dataspace */
+                    if (!parms->dim2d) {
+                        /* Contiguous pattern */
+                        if (!parms->interleaved) {
+                            /* Compute file offset */
+                            file_offset = posix_file_offset + (off_t)nbytes_xfer;
+
+                            /* only care if seek returns error */
+                            rc = POSIXSEEK(fd->posixfd, file_offset) < 0 ? -1 : 0;
+                            VRFY((rc == 0), "POSIXSEEK");
+
+                            /* check if all bytes are read */
+                            rc = ((ssize_t)buf_size == POSIXREAD(fd->posixfd, buffer, buf_size));
+                            VRFY((rc != 0), "POSIXREAD");
+
+                            /* Advance global offset in dataset */
+                            nbytes_xfer += (off_t)buf_size;
+                        } /* end if */
+                        /* Interleaved access pattern */
+                        else {
+                            /* Set the base of user's buffer */
+                            buf_p = (unsigned char *)buffer;
+
+                            /* Set the number of bytes to transfer this time */
+                            nbytes_toxfer = buf_size;
+
+                            /* Loop over the buffers to read */
+                            while (nbytes_toxfer > 0) {
+                                /* Skip offset over blocks of other processes */
+                                file_offset = posix_file_offset + (off_t)(nbytes_xfer * pio_mpi_nprocs_g);
+
+                                /* only care if seek returns error */
+                                rc = POSIXSEEK(fd->posixfd, file_offset) < 0 ? -1 : 0;
+                                VRFY((rc == 0), "POSIXSEEK");
+
+                                /* check if all bytes are read */
+                                rc = ((ssize_t)blk_size == POSIXREAD(fd->posixfd, buf_p, blk_size));
+                                VRFY((rc != 0), "POSIXREAD");
+
+                                /* Advance location in buffer */
+                                buf_p += blk_size;
+
+                                /* Advance global offset in dataset */
+                                nbytes_xfer += (off_t)blk_size;
+
+                                /* Decrement number of bytes left this time */
+                                nbytes_toxfer -= blk_size;
+                            } /* end while */
+                        }     /* end else */
+                    }         /* end if */
+                    /* 2D dataspace */
                     else {
+                        /* Contiguous storage */
+                        if (!parms->h5_use_chunks) {
+                            /* Contiguous access pattern */
+                            if (!parms->interleaved) {
+                                /* Compute file offset */
+                                file_offset = posix_file_offset +
+                                              (off_t)((((size_t)nbytes_xfer / blk_size) / (size_t)snbytes) *
+                                                          (blk_size * (size_t)snbytes) +
+                                                      (((size_t)nbytes_xfer / blk_size) % (size_t)snbytes));
+
+                                /* Number of bytes to be transferred per I/O operation */
+                                nbytes_xfer_advance = buf_size;
+
+                                /* Global offset advance after each I/O operation */
+                                file_offset_advance = (off_t)snbytes;
+                            } /* end if */
+                            /* Interleaved access pattern */
+                            else {
+                                /* Compute file offset */
+                                file_offset =
+                                    posix_file_offset +
+                                    (off_t)(((((size_t)nbytes_xfer / buf_size) * (size_t)pio_mpi_nprocs_g) /
+                                             (size_t)snbytes) *
+                                                (buf_size * (size_t)snbytes) +
+                                            (((size_t)nbytes_xfer / buf_size) * (size_t)pio_mpi_nprocs_g) %
+                                                (size_t)snbytes);
+
+                                /* Number of bytes to be transferred per I/O operation */
+                                nbytes_xfer_advance = blk_size;
+
+                                /* Global offset advance after each I/O operation */
+                                file_offset_advance = (off_t)snbytes;
+                            } /* end else */
+                        }     /* end if */
+                        /* Chunked storage */
+                        else {
+                            /*Contiguous access pattern */
+                            if (!parms->interleaved) {
+                                /* Compute file offset */
+                                file_offset = posix_file_offset + (off_t)nbytes_xfer;
+
+                                /* Number of bytes to be transferred per I/O operation */
+                                nbytes_xfer_advance = blk_size * buf_size;
+
+                                /* Global offset advance after each I/O operation */
+                                file_offset_advance = 0;
+                            } /* end if */
+                            /*Interleaved access pattern */
+                            else {
+                                /* Compute file offset */
+                                /* Before simplification */
+                                /* file_offset=posix_file_offset+(off_t)((nbytes_xfer/(buf_size/blk_size)
+                                 *pio_mpi_nprocs_g)/(snbytes/blk_size*(blk_size*blk_size))*(buf_size/blk_size
+                                 *snbytes/blk_size*(blk_size*blk_size))+((nbytes_xfer/(buf_size/blk_size))
+                                 *pio_mpi_nprocs_g)%(snbytes/blk_size*(blk_size*blk_size))); */
+
+                                file_offset = posix_file_offset +
+                                              (off_t)((((size_t)nbytes_xfer / (buf_size / blk_size) *
+                                                        (size_t)pio_mpi_nprocs_g) /
+                                                       ((size_t)snbytes * blk_size)) *
+                                                          (buf_size * (size_t)snbytes) +
+                                                      (((size_t)nbytes_xfer / (buf_size / blk_size)) *
+                                                       (size_t)pio_mpi_nprocs_g) %
+                                                          ((size_t)snbytes * blk_size));
+
+                                /* Number of bytes to be transferred per I/O operation */
+                                nbytes_xfer_advance = blk_size * blk_size;
+
+                                /* Global offset advance after each I/O operation */
+                                /* file_offset_advance = (off_t)(snbytes/blk_size*(blk_size*blk_size)); */
+                                file_offset_advance = (off_t)((size_t)snbytes * blk_size);
+                            } /* end else */
+                        }     /* end else */
+
+                        /* Common code for file access */
+
                         /* Set the base of user's buffer */
-                        buf_p=(unsigned char *)buffer;
+                        buf_p = (unsigned char *)buffer;
 
                         /* Set the number of bytes to transfer this time */
-                        nbytes_toxfer = buf_size;
+                        nbytes_toxfer = buf_size * blk_size;
 
-                        /* Loop over the buffers to read */
-                        while(nbytes_toxfer>0) {
-                            /* Skip offset over blocks of other processes */
-                            mpi_offset = mpi_file_offset +
-                            (nbytes_xfer*pio_mpi_nprocs_g);
+                        /* Loop over portions of the buffer to read */
+                        while (nbytes_toxfer > 0) {
+                            /* only care if seek returns error */
+                            rc = POSIXSEEK(fd->posixfd, file_offset) < 0 ? -1 : 0;
+                            VRFY((rc == 0), "POSIXSEEK");
 
-                            /* Perform independent read */
-                            mrc = MPI_File_read_at(fd->mpifd, mpi_offset, buf_p,
-                                (int)1, mpi_blk_type, &mpi_status);
-                            VRFY((mrc==MPI_SUCCESS), "MPIO_READ");
+                            /* check if all bytes are read */
+                            rc = ((ssize_t)nbytes_xfer_advance ==
+                                  POSIXREAD(fd->posixfd, buf_p, nbytes_xfer_advance));
+                            VRFY((rc != 0), "POSIXREAD");
 
                             /* Advance location in buffer */
-                            buf_p+=blk_size;
+                            buf_p += nbytes_xfer_advance;
 
                             /* Advance global offset in dataset */
-                            nbytes_xfer+=(off_t)blk_size;
+                            nbytes_xfer += (off_t)nbytes_xfer_advance;
 
                             /* Decrement number of bytes left this time */
-                            nbytes_toxfer-=blk_size;
-                        } /* end while */
-                    } /* end else */
-                } /* end if */
-                /* Collective file access */
-                else {
-                    /* Contiguous access pattern */
-                    if (!parms->interleaved){
-                        /* Compute offset in file */
-                        mpi_offset = mpi_file_offset +
-                            nbytes_xfer;
-
-                        /* Perform collective read */
-                        mrc = MPI_File_read_at_all(fd->mpifd, mpi_offset, buffer,
-                            (int)(buf_size/blk_size), mpi_blk_type, &mpi_status);
-                        VRFY((mrc==MPI_SUCCESS), "MPIO_READ");
-
-                        /* Advance global offset in dataset */
-                        nbytes_xfer+=(off_t)buf_size;
-                    } /* end if */
-                    /* Interleaved access pattern */
-                    else {
-                        /* Compute offset in file */
-                        mpi_offset = mpi_file_offset +
-                            (nbytes_xfer*pio_mpi_nprocs_g);
-
-                        /* Set the file view */
-                        mrc = MPI_File_set_view(fd->mpifd, mpi_offset, mpi_blk_type,
-                            mpi_file_type, (char*)"native",  h5_io_info_g);
-                        VRFY((mrc==MPI_SUCCESS), "MPIO_VIEW");
-
-                        /* Perform collective read */
-                        mrc = MPI_File_read_at_all(fd->mpifd, 0, buffer,
-                            (int)(buf_size/blk_size), mpi_blk_type, &mpi_status);
-                        VRFY((mrc==MPI_SUCCESS), "MPIO_READ");
-
-                        /* Advance global offset in dataset */
-                        nbytes_xfer+=(off_t)buf_size;
-                    } /* end else */
-                } /* end else */
-            } /* end if */
-            /* 2D dataspace */
-            else {
-                /* Contiguous storage */
-                if (!parms->h5_use_chunks) {
-                    /* Contiguous access pattern */
-                    if (!parms->interleaved) {
-                        /* Compute offset in file */
-                        mpi_offset=mpi_file_offset+(MPI_Offset)((((size_t)nbytes_xfer/blk_size)/(size_t)snbytes)*
-                            (blk_size*(size_t)snbytes))+(MPI_Offset)(((size_t)nbytes_xfer/blk_size)%(size_t)snbytes);
-
-                        /* Number of bytes to be transferred per I/O operation */
-                        nbytes_xfer_advance = buf_size;
+                            nbytes_toxfer -= nbytes_xfer_advance;
 
-                        /* Global offset advance after each I/O operation */
-                        mpi_offset_advance = snbytes;
+                            /* Partially advance file offset */
+                            file_offset += file_offset_advance;
+                        } /* end while */
 
-                        /* MPI type to be used for collective access */
-                        mpi_collective_type = mpi_cont_type;
-                    } /* end if */
-                    /* Interleaved access pattern */
+                    } /* end else */
+                    break;
+
+                case MPIO:
+                    /* 1D dataspace */
+                    if (!parms->dim2d) {
+                        /* Independent file access */
+                        if (!parms->collective) {
+                            /* Contiguous pattern */
+                            if (!parms->interleaved) {
+                                /* Compute offset in file */
+                                mpi_offset = mpi_file_offset + nbytes_xfer;
+
+                                /* Perform independent read */
+                                mrc = MPI_File_read_at(fd->mpifd, mpi_offset, buffer,
+                                                       (int)(buf_size / blk_size), mpi_blk_type, &mpi_status);
+                                VRFY((mrc == MPI_SUCCESS), "MPIO_READ");
+
+                                /* Advance global offset in dataset */
+                                nbytes_xfer += (off_t)buf_size;
+                            } /* end if */
+                            /* Interleaved access pattern */
+                            else {
+                                /* Set the base of user's buffer */
+                                buf_p = (unsigned char *)buffer;
+
+                                /* Set the number of bytes to transfer this time */
+                                nbytes_toxfer = buf_size;
+
+                                /* Loop over the buffers to read */
+                                while (nbytes_toxfer > 0) {
+                                    /* Skip offset over blocks of other processes */
+                                    mpi_offset = mpi_file_offset + (nbytes_xfer * pio_mpi_nprocs_g);
+
+                                    /* Perform independent read */
+                                    mrc = MPI_File_read_at(fd->mpifd, mpi_offset, buf_p, (int)1, mpi_blk_type,
+                                                           &mpi_status);
+                                    VRFY((mrc == MPI_SUCCESS), "MPIO_READ");
+
+                                    /* Advance location in buffer */
+                                    buf_p += blk_size;
+
+                                    /* Advance global offset in dataset */
+                                    nbytes_xfer += (off_t)blk_size;
+
+                                    /* Decrement number of bytes left this time */
+                                    nbytes_toxfer -= blk_size;
+                                } /* end while */
+                            }     /* end else */
+                        }         /* end if */
+                        /* Collective file access */
+                        else {
+                            /* Contiguous access pattern */
+                            if (!parms->interleaved) {
+                                /* Compute offset in file */
+                                mpi_offset = mpi_file_offset + nbytes_xfer;
+
+                                /* Perform collective read */
+                                mrc = MPI_File_read_at_all(fd->mpifd, mpi_offset, buffer,
+                                                           (int)(buf_size / blk_size), mpi_blk_type,
+                                                           &mpi_status);
+                                VRFY((mrc == MPI_SUCCESS), "MPIO_READ");
+
+                                /* Advance global offset in dataset */
+                                nbytes_xfer += (off_t)buf_size;
+                            } /* end if */
+                            /* Interleaved access pattern */
+                            else {
+                                /* Compute offset in file */
+                                mpi_offset = mpi_file_offset + (nbytes_xfer * pio_mpi_nprocs_g);
+
+                                /* Set the file view */
+                                mrc = MPI_File_set_view(fd->mpifd, mpi_offset, mpi_blk_type, mpi_file_type,
+                                                        (char *)"native", h5_io_info_g);
+                                VRFY((mrc == MPI_SUCCESS), "MPIO_VIEW");
+
+                                /* Perform collective read */
+                                mrc = MPI_File_read_at_all(fd->mpifd, 0, buffer, (int)(buf_size / blk_size),
+                                                           mpi_blk_type, &mpi_status);
+                                VRFY((mrc == MPI_SUCCESS), "MPIO_READ");
+
+                                /* Advance global offset in dataset */
+                                nbytes_xfer += (off_t)buf_size;
+                            } /* end else */
+                        }     /* end else */
+                    }         /* end if */
+                    /* 2D dataspace */
                     else {
-                        /* Compute offset in file */
-                        mpi_offset=mpi_file_offset+(MPI_Offset)(((((size_t)nbytes_xfer/buf_size)*(size_t)pio_mpi_nprocs_g)/(size_t)snbytes)*
-                            (buf_size*(size_t)snbytes))+(MPI_Offset)((((size_t)nbytes_xfer/buf_size)*(size_t)pio_mpi_nprocs_g)%(size_t)snbytes);
-
-                        /* Number of bytes to be transferred per I/O operation */
-                        nbytes_xfer_advance = blk_size;
+                        /* Contiguous storage */
+                        if (!parms->h5_use_chunks) {
+                            /* Contiguous access pattern */
+                            if (!parms->interleaved) {
+                                /* Compute offset in file */
+                                mpi_offset =
+                                    mpi_file_offset +
+                                    (MPI_Offset)((((size_t)nbytes_xfer / blk_size) / (size_t)snbytes) *
+                                                 (blk_size * (size_t)snbytes)) +
+                                    (MPI_Offset)(((size_t)nbytes_xfer / blk_size) % (size_t)snbytes);
+
+                                /* Number of bytes to be transferred per I/O operation */
+                                nbytes_xfer_advance = buf_size;
+
+                                /* Global offset advance after each I/O operation */
+                                mpi_offset_advance = snbytes;
+
+                                /* MPI type to be used for collective access */
+                                mpi_collective_type = mpi_cont_type;
+                            } /* end if */
+                            /* Interleaved access pattern */
+                            else {
+                                /* Compute offset in file */
+                                mpi_offset =
+                                    mpi_file_offset +
+                                    (MPI_Offset)(
+                                        ((((size_t)nbytes_xfer / buf_size) * (size_t)pio_mpi_nprocs_g) /
+                                         (size_t)snbytes) *
+                                        (buf_size * (size_t)snbytes)) +
+                                    (MPI_Offset)(
+                                        (((size_t)nbytes_xfer / buf_size) * (size_t)pio_mpi_nprocs_g) %
+                                        (size_t)snbytes);
+
+                                /* Number of bytes to be transferred per I/O operation */
+                                nbytes_xfer_advance = blk_size;
+
+                                /* Global offset advance after each I/O operation */
+                                mpi_offset_advance = snbytes;
+
+                                /* MPI type to be used for collective access */
+                                mpi_collective_type = mpi_inter_type;
+                            } /* end else */
+                        }     /* end if */
+                        /* Chunked storage */
+                        else {
+                            /*Contiguous access pattern */
+                            if (!parms->interleaved) {
+                                /* Compute offset in file */
+                                mpi_offset = mpi_file_offset + nbytes_xfer;
+
+                                /* Number of bytes to be transferred per I/O operation */
+                                nbytes_xfer_advance = blk_size * buf_size;
+
+                                /* Global offset advance after each I/O operation */
+                                mpi_offset_advance = 0;
+
+                                /* MPI type to be used for collective access */
+                                mpi_collective_type = mpi_full_buffer;
+                            } /* end if */
+                            /*Interleaved access pattern */
+                            else {
+                                /* Compute offset in file */
+                                /* Before simplification */
+                                /* mpi_offset=mpi_file_offset+(nbytes_xfer/(buf_size/blk_size)
+                                    *pio_mpi_nprocs_g)/(snbytes/blk_size*(blk_size*blk_size))*
+                                    (buf_size/blk_size*snbytes/blk_size*(blk_size*blk_size))+
+                                    ((nbytes_xfer/(buf_size/blk_size))*pio_mpi_nprocs_g)%(snbytes
+                                    /blk_size*(blk_size*blk_size)); */
+                                mpi_offset = mpi_file_offset +
+                                             (MPI_Offset)((((size_t)nbytes_xfer / (buf_size / blk_size) *
+                                                            (size_t)pio_mpi_nprocs_g) /
+                                                           ((size_t)snbytes * blk_size)) *
+                                                          (buf_size * (size_t)snbytes)) +
+                                             (MPI_Offset)((((size_t)nbytes_xfer / (buf_size / blk_size)) *
+                                                           (size_t)pio_mpi_nprocs_g) %
+                                                          ((size_t)snbytes * blk_size));
+
+                                /* Number of bytes to be transferred per I/O operation */
+                                nbytes_xfer_advance = blk_size * blk_size;
+
+                                /* Global offset advance after each I/O operation */
+                                /* mpi_offset_advance = (MPI_Offset)(snbytes/blk_size*(blk_size*blk_size)); */
+                                mpi_offset_advance = (MPI_Offset)((size_t)snbytes * blk_size);
+
+                                /* MPI type to be used for collective access */
+                                mpi_collective_type = mpi_chunk_inter_type;
+                            } /* end else */
+                        }     /* end else */
+
+                        /* Common code for independent file access */
+                        if (!parms->collective) {
+                            /* Set the base of user's buffer */
+                            buf_p = (unsigned char *)buffer;
+
+                            /* Set the number of bytes to transfer this time */
+                            nbytes_toxfer = buf_size * blk_size;
+
+                            /* Loop over portions of the buffer to read */
+                            while (nbytes_toxfer > 0) {
+                                /* Perform independent read */
+                                mrc = MPI_File_read_at(fd->mpifd, mpi_offset, buf_p, (int)nbytes_xfer_advance,
+                                                       MPI_BYTE, &mpi_status);
+                                VRFY((mrc == MPI_SUCCESS), "MPIO_READ");
+
+                                /* Advance location in buffer */
+                                buf_p += nbytes_xfer_advance;
+
+                                /* Advance global offset in dataset */
+                                nbytes_xfer += (off_t)nbytes_xfer_advance;
+
+                                /* Decrement number of bytes left this time */
+                                nbytes_toxfer -= nbytes_xfer_advance;
+
+                                /* Partially advance global offset in dataset */
+                                mpi_offset += mpi_offset_advance;
+                            } /* end while */
+                        }     /* end if */
+
+                        /* Common code for collective file access */
+                        else {
+                            /* Set the file view */
+                            mrc = MPI_File_set_view(fd->mpifd, mpi_offset, MPI_BYTE, mpi_collective_type,
+                                                    (char *)"native", h5_io_info_g);
+                            VRFY((mrc == MPI_SUCCESS), "MPIO_VIEW");
+
+                            /* Perform read */
+                            MPI_File_read_at_all(fd->mpifd, 0, buffer, (int)(buf_size * blk_size), MPI_BYTE,
+                                                 &mpi_status);
+                            VRFY((mrc == MPI_SUCCESS), "MPIO_READ");
 
-                        /* Global offset advance after each I/O operation */
-                        mpi_offset_advance = snbytes;
+                            /* Advance global offset in dataset */
+                            nbytes_xfer += (off_t)buf_size * (off_t)blk_size;
+                        } /* end else */
 
-                        /* MPI type to be used for collective access */
-                        mpi_collective_type = mpi_inter_type;
                     } /* end else */
-                } /* end if */
-                /* Chunked storage */
-                else {
-                    /*Contiguous access pattern */
-                    if (!parms->interleaved) {
-                        /* Compute offset in file */
-                        mpi_offset=mpi_file_offset+nbytes_xfer;
-
-                        /* Number of bytes to be transferred per I/O operation */
-                        nbytes_xfer_advance = blk_size * buf_size;
+                    break;
+
+                case PHDF5:
+                    /* 1D dataspace */
+                    if (!parms->dim2d) {
+                        /* Set up the file dset space id to move the selection to process */
+                        if (!parms->interleaved) {
+                            /* Contiguous pattern */
+                            h5offset[0] = nbytes_xfer;
+                        } /* end if */
+                        else {
+                            /* Interleaved access pattern */
+                            /* Skip offset over blocks of other processes */
+                            h5offset[0] = (nbytes_xfer * pio_mpi_nprocs_g);
+                        } /* end else */
+                        hrc = H5Soffset_simple(h5dset_space_id, h5offset);
+                        VRFY((hrc >= 0), "H5Soffset_simple");
 
-                        /* Global offset advance after each I/O operation */
-                        mpi_offset_advance = 0;
+                        /* Read the buffer in */
+                        hrc = H5Dread(h5ds_id, ELMT_H5_TYPE, h5mem_space_id, h5dset_space_id, h5dxpl, buffer);
+                        VRFY((hrc >= 0), "H5Dread");
 
-                        /* MPI type to be used for collective access */
-                        mpi_collective_type = mpi_full_buffer;
+                        /* Increment number of bytes transferred */
+                        nbytes_xfer += (off_t)buf_size;
                     } /* end if */
-                    /*Interleaved access pattern */
+                    /* 2D dataspace */
                     else {
-                        /* Compute offset in file */
-                        /* Before simplification */
-                        /* mpi_offset=mpi_file_offset+(nbytes_xfer/(buf_size/blk_size)
-                            *pio_mpi_nprocs_g)/(snbytes/blk_size*(blk_size*blk_size))*
-                            (buf_size/blk_size*snbytes/blk_size*(blk_size*blk_size))+
-                            ((nbytes_xfer/(buf_size/blk_size))*pio_mpi_nprocs_g)%(snbytes
-                            /blk_size*(blk_size*blk_size)); */
-                        mpi_offset=mpi_file_offset+(MPI_Offset)((((size_t)nbytes_xfer/(buf_size/blk_size)
-                            *(size_t)pio_mpi_nprocs_g)/((size_t)snbytes*blk_size))*(buf_size*(size_t)snbytes))
-                            +(MPI_Offset)((((size_t)nbytes_xfer/(buf_size/blk_size))*(size_t)pio_mpi_nprocs_g)%((size_t)snbytes*blk_size));
-
-                        /* Number of bytes to be transferred per I/O operation */
-                        nbytes_xfer_advance = blk_size * blk_size;
-
-                        /* Global offset advance after each I/O operation */
-                        /* mpi_offset_advance = (MPI_Offset)(snbytes/blk_size*(blk_size*blk_size)); */
-                        mpi_offset_advance = (MPI_Offset)((size_t)snbytes*blk_size);
-
-                        /* MPI type to be used for collective access */
-                        mpi_collective_type = mpi_chunk_inter_type;
-                    } /* end else */
-                } /* end else */
-
-                /* Common code for independent file access */
-                if (!parms->collective) {
-                    /* Set the base of user's buffer */
-                    buf_p = (unsigned char *)buffer;
-
-                    /* Set the number of bytes to transfer this time */
-                    nbytes_toxfer = buf_size * blk_size;
-
-                    /* Loop over portions of the buffer to read */
-                    while(nbytes_toxfer>0){
-                        /* Perform independent read */
-                        mrc = MPI_File_read_at(fd->mpifd, mpi_offset, buf_p,
-                            (int)nbytes_xfer_advance, MPI_BYTE, &mpi_status);
-                        VRFY((mrc==MPI_SUCCESS), "MPIO_READ");
+                        /* Set up the file dset space id to move the selection to process */
+                        if (!parms->interleaved) {
+                            /* Contiguous pattern */
+                            h5offset[0] =
+                                (hssize_t)(((size_t)nbytes_xfer / ((size_t)snbytes * blk_size)) * blk_size);
+                            h5offset[1] =
+                                (hssize_t)(((size_t)nbytes_xfer % ((size_t)snbytes * blk_size)) / blk_size);
+                        } /* end if */
+                        else {
+                            /* Interleaved access pattern */
+                            /* Skip offset over blocks of other processes */
+                            h5offset[0] = (hssize_t)((((size_t)nbytes_xfer * (size_t)pio_mpi_nprocs_g) /
+                                                      ((size_t)snbytes * buf_size)) *
+                                                     buf_size);
+                            h5offset[1] = (hssize_t)((((size_t)nbytes_xfer * (size_t)pio_mpi_nprocs_g) %
+                                                      ((size_t)snbytes * buf_size)) /
+                                                     buf_size);
 
-                        /* Advance location in buffer */
-                        buf_p+=nbytes_xfer_advance;
+                        } /* end else */
+                        hrc = H5Soffset_simple(h5dset_space_id, h5offset);
+                        VRFY((hrc >= 0), "H5Soffset_simple");
 
-                        /* Advance global offset in dataset */
-                        nbytes_xfer+=(off_t)nbytes_xfer_advance;
+                        /* Write the buffer out */
+                        hrc = H5Dread(h5ds_id, ELMT_H5_TYPE, h5mem_space_id, h5dset_space_id, h5dxpl, buffer);
+                        VRFY((hrc >= 0), "H5Dread");
 
-                        /* Decrement number of bytes left this time */
-                        nbytes_toxfer-=nbytes_xfer_advance;
+                        /* Increment number of bytes transferred */
+                        nbytes_xfer += (off_t)buf_size * (off_t)blk_size;
 
-                        /* Partially advance global offset in dataset */
-                        mpi_offset+=mpi_offset_advance;
-                    } /* end while */
+                    } /* end else */
+                    break;
+
+                default:
+                    break;
+            } /* switch (parms->io_type) */
+
+            /* Verify raw data, if asked */
+            if (parms->verify) {
+                /* Verify data read */
+                unsigned char *ucharptr = (unsigned char *)buffer;
+                size_t         i;
+                int            nerror = 0;
+
+                for (i = 0; i < bsize; ++i) {
+                    if (*ucharptr++ != pio_mpi_rank_g + 1) {
+                        if (++nerror < 20) {
+                            /* report at most 20 errors */
+                            HDprint_rank(output);
+                            HDfprintf(output,
+                                      "read data error, expected (%d), "
+                                      "got (%d)\n",
+                                      pio_mpi_rank_g + 1, (int)*(ucharptr - 1));
+                        } /* end if */
+                    }     /* end if */
+                }         /* end for */
+                if (nerror >= 20) {
+                    HDprint_rank(output);
+                    HDfprintf(output, "...");
+                    HDfprintf(output, "total read data errors=%d\n", nerror);
                 } /* end if */
+            }     /* if (parms->verify) */
 
-                /* Common code for collective file access */
-                else {
-                    /* Set the file view */
-                    mrc = MPI_File_set_view(fd->mpifd, mpi_offset, MPI_BYTE,
-                        mpi_collective_type, (char *)"native", h5_io_info_g);
-                    VRFY((mrc==MPI_SUCCESS), "MPIO_VIEW");
-
-                    /* Perform read */
-                    MPI_File_read_at_all(fd->mpifd, 0, buffer,(int)(buf_size*blk_size),
-                        MPI_BYTE, &mpi_status);
-                    VRFY((mrc==MPI_SUCCESS), "MPIO_READ");
-
-                    /* Advance global offset in dataset */
-                    nbytes_xfer+=(off_t)buf_size*(off_t)blk_size;
-                } /* end else */
+        } /* end while */
 
-            } /* end else */
-            break;
+        /* Stop "raw data" read timer */
+        io_time_set(res->timers, HDF5_RAW_READ_FIXED_DIMS, TSTOP);
 
-        case PHDF5:
-            /* 1D dataspace */
-            if (!parms->dim2d){
-            /* Set up the file dset space id to move the selection to process */
-            if (!parms->interleaved){
-                /* Contiguous pattern */
-                h5offset[0] = nbytes_xfer;
-            } /* end if */
-            else {
-                /* Interleaved access pattern */
-                /* Skip offset over blocks of other processes */
-                h5offset[0] = (nbytes_xfer*pio_mpi_nprocs_g);
-            } /* end else */
-            hrc = H5Soffset_simple(h5dset_space_id, h5offset);
-            VRFY((hrc >= 0), "H5Soffset_simple");
-
-            /* Read the buffer in */
-            hrc = H5Dread(h5ds_id, ELMT_H5_TYPE, h5mem_space_id,
-                h5dset_space_id, h5dxpl, buffer);
-            VRFY((hrc >= 0), "H5Dread");
+        /* Calculate read time */
 
-            /* Increment number of bytes transferred */
-            nbytes_xfer += (off_t)buf_size;
-            } /* end if */
-            /* 2D dataspace */
-            else {
-            /* Set up the file dset space id to move the selection to process */
-            if (!parms->interleaved){
-                /* Contiguous pattern */
-                h5offset[0] = (hssize_t)(((size_t)nbytes_xfer/((size_t)snbytes*blk_size))*blk_size);
-                h5offset[1] = (hssize_t)(((size_t)nbytes_xfer%((size_t)snbytes*blk_size))/blk_size);
-            } /* end if */
-            else {
-                /* Interleaved access pattern */
-                /* Skip offset over blocks of other processes */
-                h5offset[0] = (hssize_t)((((size_t)nbytes_xfer*(size_t)pio_mpi_nprocs_g)/((size_t)snbytes*buf_size))*buf_size);
-                h5offset[1] = (hssize_t)((((size_t)nbytes_xfer*(size_t)pio_mpi_nprocs_g)%((size_t)snbytes*buf_size))/buf_size);
+        /* Close dataset. Only HDF5 needs to do an explicit close. */
+        if (parms->io_type == PHDF5) {
+            hrc = H5Dclose(h5ds_id);
 
-            } /* end else */
-            hrc = H5Soffset_simple(h5dset_space_id, h5offset);
-            VRFY((hrc >= 0), "H5Soffset_simple");
-
-            /* Write the buffer out */
-            hrc = H5Dread(h5ds_id, ELMT_H5_TYPE, h5mem_space_id,
-                h5dset_space_id, h5dxpl, buffer);
-            VRFY((hrc >= 0), "H5Dread");
-
-            /* Increment number of bytes transferred */
-            nbytes_xfer += (off_t)buf_size*(off_t)blk_size;
-
-            } /* end else */
-            break;
+            if (hrc < 0) {
+                HDfprintf(stderr, "HDF5 Dataset Close failed\n");
+                GOTOERROR(FAIL);
+            }
 
-        default:
-            break;
-        } /* switch (parms->io_type) */
-
-        /* Verify raw data, if asked */
-        if (parms->verify) {
-        /* Verify data read */
-        unsigned char *ucharptr = (unsigned char *)buffer;
-        size_t i;
-        int nerror=0;
-
-        for (i = 0; i < bsize; ++i){
-            if (*ucharptr++ != pio_mpi_rank_g+1) {
-            if (++nerror < 20){
-                /* report at most 20 errors */
-                HDprint_rank(output);
-                HDfprintf(output, "read data error, expected (%d), "
-                    "got (%d)\n",
-                    pio_mpi_rank_g+1,
-                    (int)*(ucharptr-1));
-            } /* end if */
-            } /* end if */
-        } /* end for */
-        if (nerror >= 20) {
-            HDprint_rank(output);
-            HDfprintf(output, "...");
-            HDfprintf(output, "total read data errors=%d\n",
-                nerror);
+            h5ds_id = H5I_INVALID_HID;
         } /* end if */
-        }   /* if (parms->verify) */
-
-    } /* end while */
-
-    /* Stop "raw data" read timer */
-    io_time_set(res->timers, HDF5_RAW_READ_FIXED_DIMS, TSTOP);
-
-    /* Calculate read time */
-
-    /* Close dataset. Only HDF5 needs to do an explicit close. */
-    if (parms->io_type == PHDF5) {
-        hrc = H5Dclose(h5ds_id);
-
-        if (hrc < 0) {
-        HDfprintf(stderr, "HDF5 Dataset Close failed\n");
-        GOTOERROR(FAIL);
-        }
-
-        h5ds_id = H5I_INVALID_HID;
-    } /* end if */
-    } /* end for */
+    }     /* end for */
 
 done:
     /* release MPI-I/O objects */
     if (parms->io_type == MPIO) {
         /* 1D dataspace */
-        if (!parms->dim2d){
+        if (!parms->dim2d) {
             /* Free file type */
-            mrc = MPI_Type_free( &mpi_file_type );
-            VRFY((mrc==MPI_SUCCESS), "MPIO_TYPE_FREE");
+            mrc = MPI_Type_free(&mpi_file_type);
+            VRFY((mrc == MPI_SUCCESS), "MPIO_TYPE_FREE");
 
             /* Free buffer type */
-            mrc = MPI_Type_free( &mpi_blk_type );
-            VRFY((mrc==MPI_SUCCESS), "MPIO_TYPE_FREE");
+            mrc = MPI_Type_free(&mpi_blk_type);
+            VRFY((mrc == MPI_SUCCESS), "MPIO_TYPE_FREE");
         } /* end if */
         /* 2D dataspace */
         else {
             /* Free partial buffer type for contiguous access */
-            mrc = MPI_Type_free( &mpi_partial_buffer_cont );
-            VRFY((mrc==MPI_SUCCESS), "MPIO_TYPE_FREE");
+            mrc = MPI_Type_free(&mpi_partial_buffer_cont);
+            VRFY((mrc == MPI_SUCCESS), "MPIO_TYPE_FREE");
 
             /* Free contiguous file type */
-            mrc = MPI_Type_free( &mpi_cont_type );
-            VRFY((mrc==MPI_SUCCESS), "MPIO_TYPE_FREE");
+            mrc = MPI_Type_free(&mpi_cont_type);
+            VRFY((mrc == MPI_SUCCESS), "MPIO_TYPE_FREE");
 
             /* Free partial buffer type for interleaved access */
-            mrc = MPI_Type_free( &mpi_partial_buffer_inter );
-            VRFY((mrc==MPI_SUCCESS), "MPIO_TYPE_FREE");
+            mrc = MPI_Type_free(&mpi_partial_buffer_inter);
+            VRFY((mrc == MPI_SUCCESS), "MPIO_TYPE_FREE");
 
             /* Free interleaved file type */
-            mrc = MPI_Type_free( &mpi_inter_type );
-            VRFY((mrc==MPI_SUCCESS), "MPIO_TYPE_FREE");
+            mrc = MPI_Type_free(&mpi_inter_type);
+            VRFY((mrc == MPI_SUCCESS), "MPIO_TYPE_FREE");
 
             /* Free full buffer type */
             mrc = MPI_Type_free(&mpi_full_buffer);
-            VRFY((mrc==MPI_SUCCESS), "MPIO_TYPE_FREE");
+            VRFY((mrc == MPI_SUCCESS), "MPIO_TYPE_FREE");
 
             /* Free full chunk type */
             mrc = MPI_Type_free(&mpi_full_chunk);
-            VRFY((mrc==MPI_SUCCESS), "MPIO_TYPE_FREE");
+            VRFY((mrc == MPI_SUCCESS), "MPIO_TYPE_FREE");
 
             /* Free chunk interleaved file type */
             mrc = MPI_Type_free(&mpi_chunk_inter_type);
-            VRFY((mrc==MPI_SUCCESS), "MPIO_TYPE_FREE");
+            VRFY((mrc == MPI_SUCCESS), "MPIO_TYPE_FREE");
         } /* end else */
-    } /* end if */
+    }     /* end if */
 
     /* release HDF5 objects */
     if (h5dset_space_id != -1) {
-    hrc = H5Sclose(h5dset_space_id);
-    if (hrc < 0){
-        HDfprintf(stderr, "HDF5 Dataset Space Close failed\n");
-        ret_code = FAIL;
-    } else {
-        h5dset_space_id = H5I_INVALID_HID;
-    }
+        hrc = H5Sclose(h5dset_space_id);
+        if (hrc < 0) {
+            HDfprintf(stderr, "HDF5 Dataset Space Close failed\n");
+            ret_code = FAIL;
+        }
+        else {
+            h5dset_space_id = H5I_INVALID_HID;
+        }
     }
 
     if (h5mem_space_id != -1) {
-    hrc = H5Sclose(h5mem_space_id);
-    if (hrc < 0) {
-        HDfprintf(stderr, "HDF5 Memory Space Close failed\n");
-        ret_code = FAIL;
-    } else {
-        h5mem_space_id = H5I_INVALID_HID;
-    }
+        hrc = H5Sclose(h5mem_space_id);
+        if (hrc < 0) {
+            HDfprintf(stderr, "HDF5 Memory Space Close failed\n");
+            ret_code = FAIL;
+        }
+        else {
+            h5mem_space_id = H5I_INVALID_HID;
+        }
     }
 
     if (h5dxpl != -1) {
-    hrc = H5Pclose(h5dxpl);
-    if (hrc < 0) {
-        HDfprintf(stderr, "HDF5 Dataset Transfer Property List Close failed\n");
-        ret_code = FAIL;
-    } else {
-        h5dxpl = H5I_INVALID_HID;
-    }
+        hrc = H5Pclose(h5dxpl);
+        if (hrc < 0) {
+            HDfprintf(stderr, "HDF5 Dataset Transfer Property List Close failed\n");
+            ret_code = FAIL;
+        }
+        else {
+            h5dxpl = H5I_INVALID_HID;
+        }
     }
 
     return ret_code;
@@ -2467,11 +2504,11 @@ done:
  * Programmer:  Albert Cheng, Bill Wendling, 2001/12/13
  * Modifications:
  */
-    static herr_t
+static herr_t
 do_fopen(parameters *param, char *fname, file_descr *fd /*out*/, int flags)
 {
-    int ret_code = SUCCESS, mrc;
-    hid_t acc_tpl = H5I_INVALID_HID;         /* file access templates */
+    int   ret_code = SUCCESS, mrc;
+    hid_t acc_tpl  = H5I_INVALID_HID; /* file access templates */
 
     switch (param->io_type) {
         case POSIXIO:
@@ -2480,12 +2517,11 @@ do_fopen(parameters *param, char *fname, file_descr *fd /*out*/, int flags)
             else
                 fd->posixfd = POSIXOPEN(fname, O_RDONLY);
 
-            if (fd->posixfd < 0 ) {
+            if (fd->posixfd < 0) {
                 HDfprintf(stderr, "POSIX File Open failed(%s)\n", fname);
                 GOTOERROR(FAIL);
             }
 
-
             /* The perils of POSIX I/O in a parallel environment. The problem is:
              *
              *      - Process n opens a file with truncation and then starts
@@ -2501,8 +2537,8 @@ do_fopen(parameters *param, char *fname, file_descr *fd /*out*/, int flags)
         case MPIO:
             if (flags & (PIO_CREATE | PIO_WRITE)) {
                 MPI_File_delete(fname, h5_io_info_g);
-                mrc = MPI_File_open(pio_comm_g, fname, MPI_MODE_CREATE | MPI_MODE_RDWR,
-                    h5_io_info_g, &fd->mpifd);
+                mrc = MPI_File_open(pio_comm_g, fname, MPI_MODE_CREATE | MPI_MODE_RDWR, h5_io_info_g,
+                                    &fd->mpifd);
 
                 if (mrc != MPI_SUCCESS) {
                     HDfprintf(stderr, "MPI File Open failed(%s)\n", fname);
@@ -2516,7 +2552,8 @@ do_fopen(parameters *param, char *fname, file_descr *fd /*out*/, int flags)
                     HDfprintf(stderr, "MPI_File_set_size failed\n");
                     GOTOERROR(FAIL);
                 }
-            } else {
+            }
+            else {
                 mrc = MPI_File_open(pio_comm_g, fname, MPI_MODE_RDONLY, h5_io_info_g, &fd->mpifd);
                 if (mrc != MPI_SUCCESS) {
                     HDfprintf(stderr, "MPI File Open failed(%s)\n", fname);
@@ -2577,17 +2614,17 @@ done:
  * Programmer:  Albert Cheng, Bill Wendling, 2001/12/13
  * Modifications:
  */
-    static herr_t
+static herr_t
 do_fclose(iotype iot, file_descr *fd /*out*/)
 {
     herr_t ret_code = SUCCESS, hrc;
-    int mrc = 0, rc = 0;
+    int    mrc = 0, rc = 0;
 
     switch (iot) {
         case POSIXIO:
             rc = POSIXCLOSE(fd->posixfd);
 
-            if (rc != 0){
+            if (rc != 0) {
                 HDfprintf(stderr, "POSIX File Close failed\n");
                 GOTOERROR(FAIL);
             }
@@ -2598,7 +2635,7 @@ do_fclose(iotype iot, file_descr *fd /*out*/)
         case MPIO:
             mrc = MPI_File_close(&fd->mpifd);
 
-            if (mrc != MPI_SUCCESS){
+            if (mrc != MPI_SUCCESS) {
                 HDfprintf(stderr, "MPI File close failed\n");
                 GOTOERROR(FAIL);
             }
@@ -2625,7 +2662,6 @@ done:
     return ret_code;
 }
 
-
 /*
  * Function:    do_fclose
  * Purpose:     Cleanup temporary file unless HDF5_NOCLEANUP is set.
@@ -2635,17 +2671,17 @@ done:
  * Programmer:  Albert Cheng 2001/12/12
  * Modifications:
  */
-    static void
+static void
 do_cleanupfile(iotype iot, char *fname)
 {
     if (pio_mpi_rank_g != 0)
-    return;
+        return;
 
     if (clean_file_g == -1)
-    clean_file_g = (getenv("HDF5_NOCLEANUP")==NULL) ? 1 : 0;
+        clean_file_g = (getenv("HDF5_NOCLEANUP") == NULL) ? 1 : 0;
 
-    if (clean_file_g){
-        switch (iot){
+    if (clean_file_g) {
+        switch (iot) {
             case POSIXIO:
                 HDremove(fname);
                 break;
@@ -2663,51 +2699,49 @@ do_cleanupfile(iotype iot, char *fname)
 /* instrument the MPI_File_wrirte_xxx and read_xxx calls to measure
  * pure time spent in MPI_File code.
  */
-int MPI_File_read_at(MPI_File fh, MPI_Offset offset, void *buf,
-    int count, MPI_Datatype datatype, MPI_Status *status)
+int
+MPI_File_read_at(MPI_File fh, MPI_Offset offset, void *buf, int count, MPI_Datatype datatype,
+                 MPI_Status *status)
 {
     int err;
     io_time_set(timer_g, HDF5_MPI_READ, TSTART);
-    err=PMPI_File_read_at(fh, offset, buf, count, datatype, status);
+    err = PMPI_File_read_at(fh, offset, buf, count, datatype, status);
     io_time_set(timer_g, HDF5_MPI_READ, TSTOP);
     return err;
 }
 
-
-int MPI_File_read_at_all(MPI_File fh, MPI_Offset offset, void *buf,
-    int count, MPI_Datatype datatype, MPI_Status *status)
+int
+MPI_File_read_at_all(MPI_File fh, MPI_Offset offset, void *buf, int count, MPI_Datatype datatype,
+                     MPI_Status *status)
 {
     int err;
     io_time_set(timer_g, HDF5_MPI_READ, TSTART);
-    err=PMPI_File_read_at_all(fh, offset, buf, count, datatype, status);
+    err = PMPI_File_read_at_all(fh, offset, buf, count, datatype, status);
     io_time_set(timer_g, HDF5_MPI_READ, TSTOP);
     return err;
 }
 
-int MPI_File_write_at(MPI_File fh, MPI_Offset offset, void *buf,
-    int count, MPI_Datatype datatype, MPI_Status *status)
+int
+MPI_File_write_at(MPI_File fh, MPI_Offset offset, void *buf, int count, MPI_Datatype datatype,
+                  MPI_Status *status)
 {
     int err;
     io_time_set(timer_g, HDF5_MPI_WRITE, TSTART);
-    err=PMPI_File_write_at(fh, offset, buf, count, datatype, status);
+    err = PMPI_File_write_at(fh, offset, buf, count, datatype, status);
     io_time_set(timer_g, HDF5_MPI_WRITE, TSTOP);
     return err;
 }
 
-int MPI_File_write_at_all(MPI_File fh, MPI_Offset offset, void *buf,
-    int count, MPI_Datatype datatype, MPI_Status *status)
+int
+MPI_File_write_at_all(MPI_File fh, MPI_Offset offset, void *buf, int count, MPI_Datatype datatype,
+                      MPI_Status *status)
 {
     int err;
     io_time_set(timer_g, HDF5_MPI_WRITE, TSTART);
-    err=PMPI_File_write_at_all(fh, offset, buf, count, datatype, status);
+    err = PMPI_File_write_at_all(fh, offset, buf, count, datatype, status);
     io_time_set(timer_g, HDF5_MPI_WRITE, TSTOP);
     return err;
 }
 
-#endif  /* TIME_MPI */
+#endif /* TIME_MPI */
 #endif /* H5_HAVE_PARALLEL */
-
-
-
-
-