Merge pull request #4518 from edgargabriel/topic/disable-amode-overwrite

io/ompio: add a new option to disable amode overwriting

ompi/mca/common/ompio/common_ompio_file_open.c

@@ -112,10 +112,12 @@ int mca_common_ompio_file_open (ompi_communicator_t *comm,
 
     /* This fix is needed for data seiving to work with
        two-phase collective I/O */
-     if ((amode & MPI_MODE_WRONLY)){
-       amode -= MPI_MODE_WRONLY;
-       amode += MPI_MODE_RDWR;
-     }
+    if ( mca_io_ompio_overwrite_amode ) {
+        if ((amode & MPI_MODE_WRONLY)){
+            amode -= MPI_MODE_WRONLY;
+            amode += MPI_MODE_RDWR;
+        }
+    }
      /*--------------------------------------------------*/
 
 

ompi/mca/fcoll/two_phase/fcoll_two_phase_file_write_all.c

@@ -239,7 +239,6 @@ mca_fcoll_two_phase_file_write_all (mca_io_ompio_file_t *fh,
         two_phase_num_io_procs = fh->f_size;
     }
 
-
 #if DEBUG_ON
     printf("Number of aggregators : %ld\n", two_phase_num_io_procs);
 #endif
@@ -1074,6 +1073,18 @@ static int two_phase_exchage_data(mca_io_ompio_file_t *fh,
 		fh->f_io_array[0].length = size;
 		fh->f_io_array[0].memory_address = write_buf;
 		if (fh->f_num_of_io_entries){
+                    if ( fh->f_amode & MPI_MODE_WRONLY &&
+                         !mca_io_ompio_overwrite_amode ){
+                        if ( 0 == fh->f_rank ) {
+                            printf("\n File not opened in RDWR mode, can not continue."
+                                   "\n To resolve this problem, you can either \n"
+                                   "  a. open the file with MPI_MODE_RDWR instead of MPI_MODE_WRONLY\n"
+                                   "  b. ensure that the mca parameter mca_io_ompio_amode_overwrite is set to 1\n"
+                                   "  c. use an fcoll component that does not use data sieving (e.g. dynamic)\n");
+                        }
+                        ret = MPI_ERR_FILE;
+                        goto exit;
+                    }
 		    if ( 0 >  fh->f_fbtl->fbtl_preadv (fh)) {
 			opal_output(1, "READ FAILED\n");
                         ret = OMPI_ERROR;

ompi/mca/io/ompio/io_ompio.h

@@ -51,6 +51,7 @@ extern int mca_io_ompio_sharedfp_lazy_open;
 extern int mca_io_ompio_grouping_option;
 extern int mca_io_ompio_max_aggregators_ratio;
 extern int mca_io_ompio_aggregators_cutoff_threshold;
+extern int mca_io_ompio_overwrite_amode;
 
 OMPI_DECLSPEC extern int mca_io_ompio_coll_timing_info;
 

ompi/mca/io/ompio/io_ompio_component.c

@@ -41,6 +41,7 @@ int mca_io_ompio_coll_timing_info = 0;
 int mca_io_ompio_sharedfp_lazy_open = 0;
 int mca_io_ompio_max_aggregators_ratio=8;
 int mca_io_ompio_aggregators_cutoff_threshold=3;
+int mca_io_ompio_overwrite_amode = 1;
 
 int mca_io_ompio_grouping_option=5;
 
@@ -242,6 +243,16 @@ static int register_component(void)
                                            MCA_BASE_VAR_SCOPE_READONLY,
                                            &mca_io_ompio_aggregators_cutoff_threshold);
 
+    mca_io_ompio_overwrite_amode = 1;
+    (void) mca_base_component_var_register(&mca_io_ompio_component.io_version,
+                                           "overwrite_amode",
+                                           "Overwrite WRONLY amode to RDWR to enable data sieving "
+                                           "1: allow overwrite (default) "
+                                           "0: do not overwrite amode provided by application ",
+                                           MCA_BASE_VAR_TYPE_INT, NULL, 0, 0,
+                                           OPAL_INFO_LVL_9,
+                                           MCA_BASE_VAR_SCOPE_READONLY,
+                                           &mca_io_ompio_overwrite_amode);
 
     return OMPI_SUCCESS;
 }