The patch titled Subject: epoll: lock ep->mtx in ep_free to silence lockdep has been removed from the -mm tree. Its filename was epoll-lock-ep-mtx-in-ep_free-to-silence-lockdep.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ From: Eric Wong <normalperson@xxxxxxxx> Subject: epoll: lock ep->mtx in ep_free to silence lockdep Technically we do not need to hold ep->mtx during ep_free since we are certain there are no other users of ep at that point. However, lockdep complains with a "suspicious rcu_dereference_check() usage!" message; so lock the mutex before ep_remove to silence the warning. Signed-off-by: Eric Wong <normalperson@xxxxxxxx> Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx> Cc: Arve Hjønnevåg <arve@xxxxxxxxxxx> Cc: Davide Libenzi <davidel@xxxxxxxxxxxxxxx> Cc: Eric Dumazet <eric.dumazet@xxxxxxxxx> Cc: NeilBrown <neilb@xxxxxxx>, Cc: Rafael J. Wysocki <rjw@xxxxxxx> Cc: Oleg Nesterov <oleg@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- fs/eventpoll.c | 4 ++++ 1 file changed, 4 insertions(+) diff -puN fs/eventpoll.c~epoll-lock-ep-mtx-in-ep_free-to-silence-lockdep fs/eventpoll.c --- a/fs/eventpoll.c~epoll-lock-ep-mtx-in-ep_free-to-silence-lockdep +++ a/fs/eventpoll.c @@ -745,11 +745,15 @@ static void ep_free(struct eventpoll *ep * point we are sure no poll callbacks will be lingering around, and also by * holding "epmutex" we can be sure that no file cleanup code will hit * us during this operation. So we can avoid the lock on "ep->lock". + * We do not need to lock ep->mtx, either, we only do it to prevent + * a lockdep warning. */ + mutex_lock(&ep->mtx); while ((rbp = rb_first(&ep->rbr)) != NULL) { epi = rb_entry(rbp, struct epitem, rbn); ep_remove(ep, epi); } + mutex_unlock(&ep->mtx); mutex_unlock(&epmutex); mutex_destroy(&ep->mtx); _ Patches currently in -mm which might be from normalperson@xxxxxxxx are origin.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html