f2fs: should fail mount when trying to recover data on read-only dev

If device is read-only, we should not proceed data recovery.
But, if the previous checkpoint was done by normal clean shutdown, it's safe to
proceed the recovery, since there will be no data to be recovered.

Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index bfeab3c81a48f7440414d4a1703b42dcff7d852a..1e92c2ea6bc159da01796fe14992946dd7e532c7 100644 (file)
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -1149,6 +1149,15 @@ try_onemore:
 
        /* recover fsynced data */
        if (!test_opt(sbi, DISABLE_ROLL_FORWARD)) {
+               /*
+                * mount should be failed, when device has readonly mode, and
+                * previous checkpoint was not done by clean system shutdown.
+                */
+               if (bdev_read_only(sb->s_bdev) &&
+                               !is_set_ckpt_flags(sbi->ckpt, CP_UMOUNT_FLAG)) {
+                       err = -EROFS;
+                       goto free_kobj;
+               }
                err = recover_fsync_data(sbi);
                if (err) {
                        f2fs_msg(sb, KERN_ERR,