On Mon, Aug 11, 2014 at 4:37 PM, David Howells <dhowells@xxxxxxxxxx> wrote: > In the for-loop in the middle, if you ascend any levels at all, how are you > protected from racing with copy-ups taking place on those more rootwards > dentries? > > I can see ovl_copy_up_one() using lock_rename() on the workdir and upperdir, > but there's no relevant lock on the overlayfs fs. Locking upperdir should be enough protection. Lets say we have a race: A: copy_up(a/b/c/d) B: copy_up(a/b/e/f) Both ascend to "b" and try to lock "a". The one that wins the lock acquisition will do the copy-up, the other one will just skip it once it gets the lock. Thanks, Miklos -- 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
