diff options
| author | Winston Wen <[email protected]> | 2024-03-05 14:18:04 +0800 |
|---|---|---|
| committer | Jan Kara <[email protected]> | 2024-03-07 12:59:51 +0100 |
| commit | 0045fb1bab4eaa8f415c2fd76020bf7b2a3be47a (patch) | |
| tree | 4e73396cdf45dc8e271d51dcd2217ae4d1acba7d | |
| parent | 8c2c2549fb32f2e6dd247cfed2e23cf8456dd458 (diff) | |
fanotify: allow freeze when waiting response for permission events
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/[email protected]/
[2] https://lore.kernel.org/lkml/[email protected]/
[3] https://lore.kernel.org/linux-fsdevel/[email protected]/
[4] https://lore.kernel.org/linux-fsdevel/[email protected]/
[5] https://lore.kernel.org/linux-fsdevel/[email protected]/
[6] https://lore.kernel.org/lkml/[email protected]/
[7] https://lore.kernel.org/lkml/20230908-avoid-spurious-freezer-wakeups-v4-0-6155aa3dafae@quicinc.com/
Signed-off-by: Winston Wen <[email protected]>
Signed-off-by: Jan Kara <[email protected]>
Message-Id: <[email protected]>
| -rw-r--r-- | fs/notify/fanotify/fanotify.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c index 1e4def21811e..224bccaab4cc 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); |