* Re: [PATCH 0/2] cifs: CIFS_ENUMERATE_SNAPSHOTS fixes
[not found] ` <20170503153909.5783-1-ddiss-l3A5Bk7waGM@public.gmane.org>
` (2 preceding siblings ...)
2017-05-03 16:18 ` [PATCH 0/2] cifs: CIFS_ENUMERATE_SNAPSHOTS fixes Steve French
@ 2017-05-05 13:47 ` David Disseldorp
3 siblings, 0 replies; 5+ messages in thread
From: David Disseldorp @ 2017-05-05 13:47 UTC (permalink / raw)
To: linux-cifs-u79uwXL29TY76Z2rM5mHXA
On Wed, 3 May 2017 17:39:07 +0200, David Disseldorp wrote:
> A couple of one line fixes for the new CIFS_ENUMERATE_SNAPSHOTS
> functionality.
>
> fs/cifs/ioctl.c | 2 ++
> fs/cifs/smb2ops.c | 1 +
> 2 files changed, 3 insertions(+)
FWIW, below is the xfstests based reproducer that I used to trip the
CIFS_ENUMERATE_SNAPSHOTS and CIFS_IOC_GET_MNT_INFO bugs. It can be
run against file and dir paths on a cifs.ko mount.
As discussed with Steve, it'd probably make sense to add some sort of
xfs_io like helper to cifs-utils, to avoid polluting xfstests with
these things (cloner could also go).
Cheers, David
>From 4df1ea0e254b9b394a49606f82717302bb7fadbc Mon Sep 17 00:00:00 2001
From: David Disseldorp <ddiss-l3A5Bk7waGM@public.gmane.org>
Date: Fri, 5 May 2017 13:22:39 +0200
Subject: [PATCH] src/shot: cifs snapshot ioctl helper
Signed-off-by: David Disseldorp <ddiss-l3A5Bk7waGM@public.gmane.org>
---
src/Makefile | 2 +-
src/shot.c | 188 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 189 insertions(+), 1 deletion(-)
create mode 100644 src/shot.c
diff --git a/src/Makefile b/src/Makefile
index f1338ca9..6378e076 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 shot
SUBDIRS =
diff --git a/src/shot.c b/src/shot.c
new file mode 100644
index 00000000..f668cd62
--- /dev/null
+++ b/src/shot.c
@@ -0,0 +1,188 @@
+/*
+ * cifs.ko snapshot access utility
+ *
+ * Copyright (C) 2017 SUSE Linux GmbH. 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.
+ */
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/ioctl.h>
+#include <sys/vfs.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <errno.h>
+#include <linux/magic.h>
+#include <linux/limits.h>
+#ifdef HAVE_CIFS_IOCTL_H
+#include <cifs/ioctl.h>
+#else
+
+struct smb_snapshot_array {
+ uint32_t number_of_snapshots;
+ uint32_t number_of_snapshots_returned;
+ uint32_t snapshot_array_size;
+ /* snapshots[]; */
+};
+
+struct smb_mnt_fs_info {
+ uint32_t version; /* 0001 */
+ uint16_t protocol_id;
+ uint16_t tcon_flags;
+ uint32_t vol_serial_number;
+ uint32_t vol_create_time;
+ uint32_t share_caps;
+ uint32_t share_flags;
+ uint32_t sector_flags;
+ uint32_t optimal_sector_size;
+ uint32_t max_bytes_chunk;
+ uint32_t fs_attributes;
+ uint32_t max_path_component;
+ uint32_t device_type;
+ uint32_t device_characteristics;
+ uint32_t maximal_access;
+ uint64_t cifs_posix_caps;
+};
+
+#define CIFS_IOCTL_MAGIC 0xCF
+#define CIFS_IOC_GET_MNT_INFO _IOR(CIFS_IOCTL_MAGIC, 5, struct smb_mnt_fs_info)
+#define CIFS_ENUMERATE_SNAPSHOTS _IOR(CIFS_IOCTL_MAGIC, 6, struct smb_snapshot_array)
+
+#endif
+
+#ifndef CIFS_MAGIC_NUMBER
+#define CIFS_MAGIC_NUMBER 0xFE534D42
+#endif
+
+#define SNAPS_MAX 10
+
+static void
+usage(char *name, const char *msg)
+{
+ printf("Fatal: %s\n"
+ "Usage:\n"
+ "%s [options] <path>\n",
+ msg, name);
+ _exit(1);
+}
+
+static int
+shot_enum_path_cifs(int enum_fd)
+{
+ struct {
+ struct smb_snapshot_array hdr;
+ char snap_name[SNAPS_MAX][PATH_MAX];
+ } snaps;
+ struct smb_mnt_fs_info mnt_info;
+ int ret;
+
+ memset(&mnt_info, 0, sizeof(mnt_info));
+ ret = ioctl(enum_fd, CIFS_IOC_GET_MNT_INFO, &mnt_info);
+ if (ret != 0) {
+ ret = errno;
+ printf("failed to get mount info: %s\n", strerror(ret));
+ return ret;
+ }
+
+ memset(&snaps, 0, sizeof(snaps));
+ ret = ioctl(enum_fd, CIFS_ENUMERATE_SNAPSHOTS, &snaps);
+ if (ret != 0) {
+ ret = errno;
+ printf("failed to enum snaps: %s\n", strerror(ret));
+ }
+ return ret;
+}
+
+static int
+shot_check_fs_support(int enum_fd)
+{
+ int ret;
+ struct statfs sfs;
+
+ ret = fstatfs(enum_fd, &sfs);
+ if (ret != 0) {
+ printf("failed to stat source FS\n");
+ return errno;
+ }
+
+ if (sfs.f_type != CIFS_MAGIC_NUMBER) {
+ printf("unsupported source FS 0x%x\n",
+ (unsigned int)sfs.f_type);
+ return ENOTSUP;
+ }
+
+ return 0;
+}
+
+int
+main(int argc, char **argv)
+{
+ char *enum_path;
+ int enum_fd;
+ int ret;
+ int opt;
+
+ while ((opt = getopt(argc, argv, "")) != -1) {
+ switch (opt) {
+ default:
+ usage(argv[0], "invalid argument");
+ }
+ }
+
+ /* should be exactly one args left */
+ if (optind != argc - 1)
+ usage(argv[0], "missing mandatory path");
+
+ enum_path = (char *)strdup(argv[optind++]);
+ if (enum_path == NULL) {
+ ret = ENOMEM;
+ printf("no memory\n");
+ goto err_out;
+ }
+
+ enum_fd = open(enum_path, O_RDONLY);
+ if (enum_fd == -1) {
+ ret = errno;
+ printf("failed to open %s: %s\n", enum_path, strerror(errno));
+ goto err_path_free;
+ }
+
+ ret = shot_check_fs_support(enum_fd);
+ if (ret != 0) {
+ goto err_fd_close;
+ }
+
+ ret = shot_enum_path_cifs(enum_fd);
+ if (ret != 0) {
+ goto err_fd_close;
+ }
+
+ ret = 0;
+err_fd_close:
+ if (close(enum_fd)) {
+ ret |= errno;
+ printf("failed to close fd: %s\n", strerror(errno));
+ }
+err_path_free:
+ free(enum_path);
+err_out:
+ return ret;
+}
--
2.12.0
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