On Tue, Apr 06, 2021 at 02:15:01PM +0000, Al Viro wrote: > I'm referring to the fact that your diff is with an already modified path_lookupat() > _and_ those modifications have managed to introduce a bug your patch reverts. > No terminate_walk() paired with that path_init() failure, i.e. path_init() is > responsible for cleanups on its (many) failure exits... I can't tell without seeing the variant your diff is against, but at a guess it had a non-trivial amount of trouble with missed rcu_read_unlock() in cases when path_init() fails after having done rcu_read_lock(). For trivial testcase, consider passing -1 for dfd, so that it would fail with -EBADF. Or passing 0 for dfd and "blah" for name (assuming your stdin is not a directory). Sure, you could handle those in path_init() (or delay grabbing rcu_read_lock() in there, spreading it in a bunch of branches), but duplicated cleanup logics for a bunch of failure exits is asking for trouble.
