1 files changed, 58 insertions, 0 deletions
diff --git a/test/h5test.c b/test/h5test.c
index 33af30d..dbd1a90 100644
--- a/test/h5test.c
+++ b/test/h5test.c
@@ -2267,3 +2267,61 @@ done:
         HDfree(dup_buf);
     return ret_value;
 } /* end h5_duplicate_file_by_bytes() */
+
+/*-------------------------------------------------------------------------
+ * Function:    h5_check_if_file_locking_enabled
+ *
+ * Purpose:     Checks if file locking is enabled on this file system.
+ *
+ * Return:      SUCCEED/FAIL
+ *              are_enabled will be FALSE if file locking is disabled on
+ *              the file system of if there were errors.
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+h5_check_if_file_locking_enabled(hbool_t *is_enabled)
+{
+    const char *filename = "locking_test_file";
+    int         pmode    = O_RDWR | O_CREAT | O_TRUNC;
+    int         fd       = -1;
+
+    *is_enabled = TRUE;
+
+    if ((fd = HDopen(filename, pmode, H5_POSIX_CREATE_MODE_RW)) < 0)
+        goto error;
+
+    /* Test HDflock() to see if it works */
+    if (HDflock(fd, LOCK_EX | LOCK_NB) < 0) {
+        if (ENOSYS == errno) {
+            /* When errno is set to ENOSYS, the file system does not support
+             * locking, so ignore it. This is most frequently used on
+             * Lustre. If we also want to check for disabled NFS locks
+             * we'll need to check for ENOLCK, too. That isn't done by
+             * default here since that could also represent an actual
+             * error condition.
+             */
+            errno       = 0;
+            *is_enabled = FALSE;
+        }
+        else
+            goto error;
+    }
+    if (HDflock(fd, LOCK_UN) < 0)
+        goto error;
+
+    if (HDclose(fd) < 0)
+        goto error;
+    if (HDremove(filename) < 0)
+        goto error;
+
+    return SUCCEED;
+
+error:
+    *is_enabled = FALSE;
+    if (fd > -1) {
+        HDclose(fd);
+        HDremove(filename);
+    }
+    return FAIL;
+} /* end h5_check_if_file_locking_enabled() */