The patch titled epoll: clean up ep_modify has been removed from the -mm tree. Its filename was epoll-clean-up-ep_modify.patch This patch was dropped because it was merged into mainline or a subsystem tree The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ Subject: epoll: clean up ep_modify From: Tony Battersby <tonyb@xxxxxxxxxxxxxxx> ep_modify() doesn't need to set event.data from within the ep->lock spinlock as the comment suggests. The only place event.data is used is ep_send_events_proc(), and this is protected by ep->mtx instead of ep->lock. Also update the comment for mutex_lock() at the top of ep_scan_ready_list(), which mentions epoll_ctl(EPOLL_CTL_DEL) but not epoll_ctl(EPOLL_CTL_MOD). ep_modify() can also use spin_lock_irq() instead of spin_lock_irqsave(). Signed-off-by: Tony Battersby <tonyb@xxxxxxxxxxxxxxx> Acked-by: Davide Libenzi <davidel@xxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- fs/eventpoll.c | 19 +++++++------------ 1 file changed, 7 insertions(+), 12 deletions(-) diff -puN fs/eventpoll.c~epoll-clean-up-ep_modify fs/eventpoll.c --- a/fs/eventpoll.c~epoll-clean-up-ep_modify +++ a/fs/eventpoll.c @@ -435,7 +435,7 @@ static int ep_scan_ready_list(struct eve /* * We need to lock this because we could be hit by - * eventpoll_release_file() and epoll_ctl(EPOLL_CTL_DEL). + * eventpoll_release_file() and epoll_ctl(). */ mutex_lock(&ep->mtx); @@ -972,15 +972,14 @@ static int ep_modify(struct eventpoll *e { int pwake = 0; unsigned int revents; - unsigned long flags; /* - * Set the new event interest mask before calling f_op->poll(), otherwise - * a potential race might occur. In fact if we do this operation inside - * the lock, an event might happen between the f_op->poll() call and the - * new event set registering. + * Set the new event interest mask before calling f_op->poll(); + * otherwise we might miss an event that happens between the + * f_op->poll() call and the new event set registering. */ epi->event.events = event->events; + epi->event.data = event->data; /* protected by mtx */ /* * Get current event bits. We can safely use the file* here because @@ -988,16 +987,12 @@ static int ep_modify(struct eventpoll *e */ revents = epi->ffd.file->f_op->poll(epi->ffd.file, NULL); - spin_lock_irqsave(&ep->lock, flags); - - /* Copy the data member from inside the lock */ - epi->event.data = event->data; - /* * If the item is "hot" and it is not registered inside the ready * list, push it inside. */ if (revents & event->events) { + spin_lock_irq(&ep->lock); if (!ep_is_linked(&epi->rdllink)) { list_add_tail(&epi->rdllink, &ep->rdllist); @@ -1007,8 +1002,8 @@ static int ep_modify(struct eventpoll *e if (waitqueue_active(&ep->poll_wait)) pwake++; } + spin_unlock_irq(&ep->lock); } - spin_unlock_irqrestore(&ep->lock, flags); /* We have to call this outside the lock */ if (pwake) _ Patches currently in -mm which might be from tonyb@xxxxxxxxxxxxxxx are origin.patch vfs-improve-comment-describing-fget_light.patch make-shm_get_stat-more-robust.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