[PATCH 1/4] src/open_by_handle: helper to test open_by_handle_at() syscall

Amir Goldstein
2017-04-18T18:17:19Z

This is a clone of src/stale_handle.c test that uses generic
open_by_handle_at() syscall instead of the xfs specific ioctl.

No test is using this helper yet.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
---
src/Makefile | 2 +-
src/open_by_handle.c | 145 +++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 146 insertions(+), 1 deletion(-)
create mode 100644 src/open_by_handle.c

diff --git a/src/Makefile b/src/Makefile
index e62d7a9..6b38e77 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -22,7 +22,7 @@ LINUX_TARGETS = xfsctl bstat t_mtab getdevicesize preallo_rw_pattern_reader \
seek_copy_test t_readdir_1 t_readdir_2 fsync-tester nsexec cloner \
renameat2 t_getcwd e4compact test-nextquota punch-alternating \
attr-list-by-handle-cursor-test listxattr dio-interleaved t_dir_type \
- dio-invalidate-cache stat_test
+ dio-invalidate-cache stat_test open_by_handle

SUBDIRS =

diff --git a/src/open_by_handle.c b/src/open_by_handle.c
new file mode 100644
index 0000000..8f04865
--- /dev/null
+++ b/src/open_by_handle.c
@@ -0,0 +1,145 @@
+/*
+ * open_by_handle.c - attempt to create a file handle and open it
+ * with open_by_handle_at() syscall
+ *
+ * Copyright (C) 2017 CTERA Networks. All Rights Reserved.
+ * Author: Amir Goldstein <amir73il@gmail.com>
+ *
+ * from:
+ * stale_handle.c
+ *
+ * Copyright (C) 2010 Red Hat, Inc. All Rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#define TEST_UTIME
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <errno.h>
+#include <linux/limits.h>
+
+#define NUMFILES 1024
+
+struct handle {
+ struct file_handle fh;
+ unsigned char fid[MAX_HANDLE_SZ];
+} handle[NUMFILES];
+
+int main(int argc, char **argv)
+{
+ int i;
+ int fd;
+ int ret;
+ int failed = 0;
+ char fname[PATH_MAX];
+ char *test_dir;
+ int mount_fd, mount_id;
+
+ if (argc != 2) {
+ fprintf(stderr, "usage: open_by_handle <test_dir>\n");
+ return EXIT_FAILURE;
+ }
+
+ test_dir = argv[1];
+ mount_fd = open(test_dir, O_RDONLY|O_DIRECTORY);
+ if (mount_fd < 0) {
+ perror("open test_dir");
+ return EXIT_FAILURE;
+ }
+
+ /*
+ * create a large number of files to force allocation of new inode
+ * chunks on disk.
+ */
+ for (i=0; i < NUMFILES; i++) {
+ sprintf(fname, "%s/file%06d", test_dir, i);
+ fd = open(fname, O_RDWR | O_CREAT | O_TRUNC, 0644);
+ if (fd < 0) {
+ printf("Warning (%s,%d), open(%s) failed.\n", __FILE__, __LINE__, fname);
+ perror(fname);
+ return EXIT_FAILURE;
+ }
+ close(fd);
+ }
+
+ /* sync to get the new inodes to hit the disk */
+ sync();
+
+ /* create the handles */
+ for (i=0; i < NUMFILES; i++) {
+ sprintf(fname, "%s/file%06d", test_dir, i);
+ handle[i].fh.handle_bytes = MAX_HANDLE_SZ;
+ ret = name_to_handle_at(AT_FDCWD, fname, &handle[i].fh, &mount_id, 0);
+ if (ret < 0) {
+ perror("name_to_handle");
+ return EXIT_FAILURE;
+ }
+ }
+
+ /* unlink the files */
+ for (i=0; i < NUMFILES; i++) {
+ sprintf(fname, "%s/file%06d", test_dir, i);
+ ret = unlink(fname);
+ if (ret < 0) {
+ perror("unlink");
+ return EXIT_FAILURE;
+ }
+ }
+
+ /* sync to get log forced for unlink transactions to hit the disk */
+ sync();
+
+ /* sync once more FTW */
+ sync();
+
+ /*
+ * now drop the caches so that unlinked inodes are reclaimed and
+ * buftarg page cache is emptied so that the inode cluster has to be
+ * fetched from disk again for the open_by_handle() call.
+ */
+ ret = system("echo 3 > /proc/sys/vm/drop_caches");
+ if (ret < 0) {
+ perror("drop_caches");
+ return EXIT_FAILURE;
+ }
+
+ /*
+ * now try to open the files by the stored handles. Expecting ENOENT
+ * for all of them.
+ */
+ for (i=0; i < NUMFILES; i++) {
+ errno = 0;
+ fd = open_by_handle_at(mount_fd, &handle[i].fh, O_RDWR);
+ if (fd < 0 && (errno == ENOENT || errno == ESTALE)) {
+ continue;
+ }
+ if (fd >= 0) {
+ printf("open_by_handle(%d) opened an unlinked file!\n", i);
+ close(fd);
+ } else
+ printf("open_by_handle(%d) returned %d incorrectly on an unlinked file!\n", i, errno);
+ failed++;
+ }
+ if (failed)
+ return EXIT_FAILURE;
+ return EXIT_SUCCESS;
+}
--
2.7.4