Commit-ID: e23738a7300a7591a57a22f47b813fd1b53ec404 Gitweb: http://git.kernel.org/tip/e23738a7300a7591a57a22f47b813fd1b53ec404 Author: Peter Zijlstra <[email protected]> AuthorDate: Wed, 24 Sep 2014 10:18:50 +0200 Committer: Ingo Molnar <[email protected]> CommitDate: Tue, 28 Oct 2014 10:55:37 +0100
sched, inotify: Deal with nested sleeps inotify_read is a wait loop with sleeps in. Wait loops rely on task_struct::state and sleeps do too, since that's the only means of actually sleeping. Therefore the nested sleeps destroy the wait loop state and the wait loop breaks the sleep functions that assume TASK_RUNNING (mutex_lock). Fix this by using the new woken_wake_function and wait_woken() stuff, which registers wakeups in wait and thereby allows shrinking the task_state::state changes to the actual sleep part. Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Al Viro <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: Robert Love <[email protected]> Cc: Eric Paris <[email protected]> Cc: John McCutchan <[email protected]> Cc: Robert Love <[email protected]> Cc: Oleg Nesterov <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]> --- fs/notify/inotify/inotify_user.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/fs/notify/inotify/inotify_user.c b/fs/notify/inotify/inotify_user.c index daf7665..283aa31 100644 --- a/fs/notify/inotify/inotify_user.c +++ b/fs/notify/inotify/inotify_user.c @@ -227,14 +227,13 @@ static ssize_t inotify_read(struct file *file, char __user *buf, struct fsnotify_event *kevent; char __user *start; int ret; - DEFINE_WAIT(wait); + DEFINE_WAIT_FUNC(wait, woken_wake_function); start = buf; group = file->private_data; + add_wait_queue(&group->notification_waitq, &wait); while (1) { - prepare_to_wait(&group->notification_waitq, &wait, TASK_INTERRUPTIBLE); - mutex_lock(&group->notification_mutex); kevent = get_one_event(group, count); mutex_unlock(&group->notification_mutex); @@ -264,10 +263,10 @@ static ssize_t inotify_read(struct file *file, char __user *buf, if (start != buf) break; - schedule(); + wait_woken(&wait, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT); } + remove_wait_queue(&group->notification_waitq, &wait); - finish_wait(&group->notification_waitq, &wait); if (start != buf && ret != -EFAULT) ret = buf - start; return ret; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
