fs: invalidate sb->s_bdev on remount,ro Fixes a problem reported by "Jorge Boncompte [DTI2]" <jorge@xxxxxxxx> who is trying to snapshot a minix filesystem image. Signed-off-by: Nick Piggin <npiggin@xxxxxxx> --- fs/super.c | 8 ++++++++ 1 file changed, 8 insertions(+) Index: linux-2.6/fs/super.c =================================================================== --- linux-2.6.orig/fs/super.c +++ linux-2.6/fs/super.c @@ -647,6 +647,14 @@ int do_remount_sb(struct super_block *sb acct_auto_close(sb); shrink_dcache_sb(sb); fsync_super(sb); + /* Some filesystems modify their metadata via some other path + than the bdev buffer cache (eg. use a private mapping, or + directories in pagecache, etc). Also file data modifications + go via their own mappings. So If we try to mount readonly + then copy the filesystem from bdev, we could get stale data, + so invalidate it to give a best effort at coherency. */ + if (flags & MS_RDONLY && sb->s_bdev) + invalidate_bdev(sb->s_bdev); /* If we are remounting RDONLY and current sb is read/write, make sure there are no rw files opened */ -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
