[svn-r414] Problem:

    Parallel File open has a racing condition if file already exists.
    Some processes see file exists, then truncate it (some system
    by remove and create).  Some processes does not see the file
    exist, then attempt to just create it.  Inconsistency.
Solution:
    Instead of opening the file with COMM_SELF (which results in
    racing condition in routine that calls it), open it with the
    communicator in access_parms.  (This assumes this access call
    must be called collectively.)
Platform tested:
    O2K.

1 files changed, 25 insertions, 14 deletions

diff --git a/src/H5Fmpio.c b/src/H5Fmpio.c
index 7b28698..4f6c275 100644
--- a/src/H5Fmpio.c
+++ b/src/H5Fmpio.c
@@ -116,6 +116,9 @@ ino_t mpio_inode_num = 0;      /* fake "inode" number */
  *		resulting in trashing the file.  It also runs the (very small)
  *		risk of having two unrelated names be seen as the same file.
  *
+ *		Must call this routine collectively since it collectively
+ *		calls MPI_File_open with the communicator in access_parms.
+ *
  * Return:      Success:        TRUE or FALSE.  If TRUE, then KEY is
  *                              initialized with data that makes this file
  *                              unique (same value as H5F_low_open).
@@ -130,6 +133,12 @@ ino_t mpio_inode_num = 0;      /* fake "inode" number */
  * 	Robb Matzke, 18 Feb 1998
  *	Added the ACCESS_PARMS argument.
  *
+ * 	June 9, 1998	Albert Cheng
+ *	Instead of opening the file with COMM_SELF (which results in
+ *	racing condition in routine that calls it), open it with the
+ *	communicator in access_parms.  (This assumes this access call
+ *	must be called collectively.)
+ *
  *-------------------------------------------------------------------------
  */
 static hbool_t
@@ -143,39 +152,41 @@ H5F_mpio_access(const char *name, const H5F_access_t *access_parms, int mode,
 
     FUNC_ENTER(H5F_mpio_access, FAIL);
 #ifdef H5F_MPIO_DEBUG
-    fprintf(stdout, "Entering H5F_mpio_access name=%s mode=%x\n", name, mode );
+    fprintf(stdout, "Entering H5F_mpio_access name=%s mode=0x%x\n", name, mode );
 #endif
+    assert(access_parms->driver == H5F_LOW_MPIO);
 
     /* The only way to get this info in MPI-IO is to try to open the file */
     /* (though particular implementations of MPI-IO may allow other ways) */
-
     switch (mode) {
 	case F_OK: mpi_mode = MPI_MODE_RDONLY;
-			   /* to see if it exists, first try to open for read */
+		   /* to see if it exists, first try to open for read */
 		   break;
 	case R_OK: mpi_mode = MPI_MODE_RDONLY;
 		   break;
 	case W_OK: mpi_mode = MPI_MODE_WRONLY;
 		   break;
 	default:   HRETURN_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL,
-                          "invalid mode parameter");
+				 "invalid mode parameter");
     }
 
     /* (char*) name is okay since MPI_File_open will not change it. */
-    mpierr = MPI_File_open( MPI_COMM_SELF, (char*) name, mpi_mode, MPI_INFO_NULL, &fh );
+    mpierr = MPI_File_open(access_parms->u.mpio.comm, (char*) name,
+			   mpi_mode, access_parms->u.mpio.info, &fh );
     if (mpierr == MPI_SUCCESS) {
 	mpierr = MPI_File_close( &fh );
-    	if (mpierr != MPI_SUCCESS)
-	    HRETURN_ERROR(H5E_IO, H5E_CLOSEERROR, FAIL, "MPI_File_close failed");
+	if (mpierr != MPI_SUCCESS)
+	    HRETURN_ERROR(H5E_IO, H5E_MPI, FAIL, "MPI_File_close failed");
 	ret_val = TRUE;
     } else if (mode == F_OK) {
 	/* to see if it exists, this time try to open for write */
-	mpierr = MPI_File_open( MPI_COMM_SELF, (char*)name, MPI_MODE_WRONLY,
-				MPI_INFO_NULL, &fh );
+	mpierr = MPI_File_open(access_parms->u.mpio.comm, (char*)name,
+			       MPI_MODE_WRONLY, access_parms->u.mpio.info,
+			       &fh );
 	if (mpierr == MPI_SUCCESS) {
 	    mpierr = MPI_File_close( &fh );
 	    if (mpierr != MPI_SUCCESS)
-		HRETURN_ERROR(H5E_IO, H5E_CLOSEERROR, FAIL, "MPI_File_close failed");
+		HRETURN_ERROR(H5E_IO, H5E_MPI, FAIL, "MPI_File_close failed");
 	    ret_val = TRUE;
 	}
     }
@@ -187,9 +198,9 @@ H5F_mpio_access(const char *name, const H5F_access_t *access_parms, int mode,
     }
 
 #ifdef H5F_MPIO_DEBUG
-    if (key)
+    if (key && (ret_val==TRUE))
     	fprintf(stdout,
-	    "Leaving H5F_mpio_access ret_val=%d key->dev=%x key->ino=%d\n",
+	    "Leaving H5F_mpio_access ret_val=%d key->dev=0x%x key->ino=%d\n",
 	    ret_val, key->dev, key->ino );
     else
     	fprintf(stdout,
@@ -238,7 +249,7 @@ H5F_mpio_open(const char *name, const H5F_access_t *access_parms, uintn flags,
 
     FUNC_ENTER(H5F_mpio_open, NULL);
 #ifdef H5F_MPIO_DEBUG
-    fprintf(stdout, "Entering H5F_mpio_open name=%s flags=%x\n", name, flags );
+    fprintf(stdout, "Entering H5F_mpio_open name=%s flags=0x%x\n", name, flags );
 #endif
 
     /* convert HDF5 flags to MPI-IO flags */
@@ -291,7 +302,7 @@ H5F_mpio_open(const char *name, const H5F_access_t *access_parms, uintn flags,
 #ifdef H5F_MPIO_DEBUG
     if (key)
     	fprintf(stdout,
-	    "Leaving H5F_mpio_open key->dev=%x key->ino=%d\n",
+	    "Leaving H5F_mpio_open key->dev=0x%x key->ino=%d\n",
 	    key->dev, key->ino );
     else
     	fprintf(stdout,