LU-7057 utils: use stronger flags when opening volatile files

[fs/lustre-release.git] / lustre / utils / liblustreapi.c

diff --git a/lustre/utils/liblustreapi.c b/lustre/utils/liblustreapi.c
index 5cab621..ff8e58d 100644 (file)
--- a/lustre/utils/liblustreapi.c
+++ b/lustre/utils/liblustreapi.c
@@ -4628,26 +4628,30 @@ int llapi_create_volatile_idx(char *directory, int idx, int open_flags)
 {
        char    file_path[PATH_MAX];
        char    filename[PATH_MAX];
+       int     saved_errno = errno;
        int     fd;
        int     rnumber;
        int     rc;
 
-       rnumber = random();
-       if (idx == -1)
-               snprintf(filename, sizeof(filename),
-                        LUSTRE_VOLATILE_HDR"::%.4X", rnumber);
-       else
-               snprintf(filename, sizeof(filename),
-                        LUSTRE_VOLATILE_HDR":%.4X:%.4X", idx, rnumber);
+       do {
+               rnumber = random();
+               if (idx == -1)
+                       snprintf(filename, sizeof(filename),
+                                LUSTRE_VOLATILE_HDR"::%.4X", rnumber);
+               else
+                       snprintf(filename, sizeof(filename),
+                                LUSTRE_VOLATILE_HDR":%.4X:%.4X", idx, rnumber);
+
+               rc = snprintf(file_path, sizeof(file_path),
+                             "%s/%s", directory, filename);
+               if (rc >= sizeof(file_path))
+                       return -E2BIG;
 
-       rc = snprintf(file_path, sizeof(file_path),
-                     "%s/%s", directory, filename);
-       if (rc >= sizeof(file_path))
-               return -E2BIG;
+               fd = open(file_path,
+                         O_RDWR | O_CREAT | O_EXCL | O_NOFOLLOW | open_flags,
+                         S_IRUSR | S_IWUSR);
+       } while (fd < 0 && errno == EEXIST);
 
-       fd = open(file_path,
-                 O_RDWR | O_CREAT | O_EXCL | O_NOFOLLOW | open_flags,
-                 S_IRUSR | S_IWUSR);
        if (fd < 0) {
                llapi_error(LLAPI_MSG_ERROR, errno,
                            "Cannot create volatile file '%s' in '%s'",
@@ -4655,10 +4659,17 @@ int llapi_create_volatile_idx(char *directory, int idx, int open_flags)
                            directory);
                return -errno;
        }
-       /* unlink file in case this wasn't a Lustre filesystem, and the
-        * magic volatile filename wasn't handled as intended.  The effect
-        * is the same. */
-       unlink(file_path);
+
+       /* Unlink file in case this wasn't a Lustre filesystem and the
+        * magic volatile filename wasn't handled as intended. The
+        * effect is the same. If volatile open was supported then we
+        * expect unlink() to return -ENOENT. */
+       (void)unlink(file_path);
+
+       /* Since we are returning successfully we restore errno (and
+        * mask out possible EEXIST from open() and ENOENT from
+        * unlink(). */
+       errno = saved_errno;
 
        return fd;
 }