This is a long-standing issue that uninterruptible sleep in fanotify could make system hibernation fail if the usperspace server gets frozen before the process waiting for the response (as reported e.g. [1][2]). A few years ago, there was an attempt to switch to interruptible sleep while waiting [3], but that would lead to EINTR returns from open(2) and break userspace [4], so it's been changed to only killable [5]. And the core freezer logic had been rewritten [6][7] in v6.1, allowing freezing in uninterrupted sleep, so we can solve this problem now. [1] https://lore.kernel.org/lkml/1518774280-38090-1-git-send-email-t.vivek@xxxxxxxxxxx/ [2] https://lore.kernel.org/lkml/c1bb16b7-9eee-9cea-2c96-a512d8b3b9c7@xxxxxxxx/ [3] https://lore.kernel.org/linux-fsdevel/20190213145443.26836-1-jack@xxxxxxx/ [4] https://lore.kernel.org/linux-fsdevel/d0031e3a-f050-0832-fa59-928a80ffd44b@xxxxxxxx/ [5] https://lore.kernel.org/linux-fsdevel/20190221105558.GA20921@xxxxxxxxxxxxxx/ [6] https://lore.kernel.org/lkml/20220822114649.055452969@xxxxxxxxxxxxx/ [7] https://lore.kernel.org/lkml/20230908-avoid-spurious-freezer-wakeups-v4-0-6155aa3dafae@xxxxxxxxxxx/ Signed-off-by: Winston Wen <wentao@xxxxxxxxxxxxx> --- fs/notify/fanotify/fanotify.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c index 1e4def21811e..285beaf5bc09 100644 --- a/fs/notify/fanotify/fanotify.c +++ b/fs/notify/fanotify/fanotify.c @@ -228,8 +228,10 @@ static int fanotify_get_response(struct fsnotify_group *group, pr_debug("%s: group=%p event=%p\n", __func__, group, event); - ret = wait_event_killable(group->fanotify_data.access_waitq, - event->state == FAN_EVENT_ANSWERED); + ret = wait_event_state(group->fanotify_data.access_waitq, + event->state == FAN_EVENT_ANSWERED, + TASK_KILLABLE|TASK_FREEZABLE); + /* Signal pending? */ if (ret < 0) { spin_lock(&group->notification_lock); -- 2.43.0
