@@ -273,7 +273,7 @@ sysdep_routines += xstatconv internal_statvfs internal_statvfs64 \
sysdep_headers += bits/fcntl-linux.h
-tests += tst-fallocate tst-fallocate64
+tests += tst-fallocate tst-fallocate64 tst-o_path-locks
endif
ifeq ($(subdir),elf)
new file mode 100644
@@ -0,0 +1,100 @@
+/* Test that closing O_PATH descriptors does not release POSIX advisory locks.
+ Copyright (C) 2020 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <https://www.gnu.org/licenses/>. */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <support/check.h>
+#include <support/namespace.h>
+#include <support/support.h>
+#include <support/temp_file.h>
+#include <support/xunistd.h>
+
+/* The subprocess writes the errno value of the lock operation
+ here. */
+static int *shared_errno;
+
+/* The path of the temporary file which is locked. */
+static char *path;
+
+/* Try to obtain an exclusive lock on the file at path. */
+static void
+subprocess (void *closure)
+{
+ int fd = xopen (path, O_RDWR, 0);
+ struct flock64 lock = { .l_type = F_WRLCK, };
+ int ret = fcntl64 (fd, F_SETLK, &lock);
+ if (ret == 0)
+ *shared_errno = 0;
+ else
+ *shared_errno = errno;
+ xclose (fd);
+}
+
+/* Return true if the file at path is currently locked, false if
+ not. */
+static bool
+probe_lock (void)
+{
+ *shared_errno = -1;
+ support_isolate_in_subprocess (subprocess, NULL);
+ if (*shared_errno == 0)
+ /* Lock was aquired by the subprocess, so this process has not
+ locked it. */
+ return false;
+ else
+ {
+ /* POSIX allows both EACCES and EAGAIN. Linux use EACCES. */
+ TEST_COMPARE (*shared_errno, EAGAIN);
+ return true;
+ }
+}
+
+static int
+do_test (void)
+{
+ shared_errno = support_shared_allocate (sizeof (*shared_errno));
+ int fd = create_temp_file ("tst-o_path-locks-", &path);
+
+ /* The file is not locked initially. */
+ TEST_VERIFY (!probe_lock ());
+
+ struct flock64 lock = { .l_type = F_WRLCK, };
+ TEST_COMPARE (fcntl64 (fd, F_SETLK, &lock), 0);
+
+ /* The lock has been acquired. */
+ TEST_VERIFY (probe_lock ());
+
+ /* Closing the same file via a different descriptor releases the
+ lock. */
+ xclose (xopen (path, O_RDONLY, 0));
+ TEST_VERIFY (!probe_lock ());
+
+ /* But not if it is an O_PATH descriptor. */
+ TEST_COMPARE (fcntl64 (fd, F_SETLK, &lock), 0);
+ xclose (xopen (path, O_PATH, 0));
+ TEST_VERIFY (probe_lock ());
+
+ xclose (fd);
+ free (path);
+ support_shared_free (shared_errno);
+ return 0;
+}
+
+#include <support/test-driver.c>