I have a trivial MPI_F08 program that opens, closes and deletes a file. When the file

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cannot MPI_File_open a one-character filename, deletes external file anyways about ompi HOT 5 OPEN

jeffhammond commented on July 18, 2024

cannot MPI_File_open a one-character filename, deletes external file anyways

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Comments (5)

ggouaillardet commented on July 18, 2024

Thanks Jeff for the report, I will have a look.

I am able to reproduce the issue (with GNU compilers fwiw)
Fun fact: no error if i run in singleton mode and/or use romio

$ mpirun -np 1 ./d
 I am            0  of            1  of WORLD
 filename = "a        "
 open failed
 why? MPI_ERR_OTHER: known error not in list
 close failed
 why? MPI_ERR_FILE: invalid file
 delete failed
 why? MPI_ERR_FILE: invalid file
 filename = "aa       "
 done

$ mpirun -np 1 --mca io ^ompio ./d
 I am            0  of            1  of WORLD
 filename = "a        "
 filename = "aa       "
 done

$ ./d
 I am            0  of            1  of WORLD
 filename = "a        "
 filename = "aa       "
 done

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ggouaillardet commented on July 18, 2024

singleton vs mpirun was fun but unrelated to the root cause.

here is a patch (opal_basename() does not correctly handle single character filename !), I will issue a PR later

diff --git a/opal/util/basename.c b/opal/util/basename.c
index 0a57b07078..ad873f2c7c 100644
--- a/opal/util/basename.c
+++ b/opal/util/basename.c
@@ -77,16 +77,18 @@ char *opal_basename(const char *filename)
 
     /* Remove trailing sep's (note that we already know that strlen > 0) */
     tmp = strdup(filename);
-    for (i = strlen(tmp) - 1; i > 0; --i) {
-        if (sep == tmp[i]) {
-            tmp[i] = '\0';
-        } else {
-            break;
+    if (1 < strlen(tmp)) {
+        for (i = strlen(tmp) - 1; i > 0; --i) {
+            if (sep == tmp[i]) {
+                tmp[i] = '\0';
+            } else {
+                break;
+            }
+        }
+        if (0 == i) {
+            tmp[0] = sep;
+            return tmp;
         }
-    }
-    if (0 == i) {
-        tmp[0] = sep;
-        return tmp;
     }
 
     /* Look for the final sep */