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authorWinston Wen <wentao@uniontech.com>2024-03-05 09:18:04 +0300
committerJan Kara <jack@suse.cz>2024-03-07 14:59:51 +0300
commit0045fb1bab4eaa8f415c2fd76020bf7b2a3be47a (patch)
tree4e73396cdf45dc8e271d51dcd2217ae4d1acba7d /fs/notify
parent8c2c2549fb32f2e6dd247cfed2e23cf8456dd458 (diff)
downloadlinux-0045fb1bab4eaa8f415c2fd76020bf7b2a3be47a.tar.xz
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/1518774280-38090-1-git-send-email-t.vivek@samsung.com/ [2] https://lore.kernel.org/lkml/c1bb16b7-9eee-9cea-2c96-a512d8b3b9c7@nwra.com/ [3] https://lore.kernel.org/linux-fsdevel/20190213145443.26836-1-jack@suse.cz/ [4] https://lore.kernel.org/linux-fsdevel/d0031e3a-f050-0832-fa59-928a80ffd44b@nwra.com/ [5] https://lore.kernel.org/linux-fsdevel/20190221105558.GA20921@quack2.suse.cz/ [6] https://lore.kernel.org/lkml/20220822114649.055452969@infradead.org/ [7] https://lore.kernel.org/lkml/20230908-avoid-spurious-freezer-wakeups-v4-0-6155aa3dafae@quicinc.com/ Signed-off-by: Winston Wen <wentao@uniontech.com> Signed-off-by: Jan Kara <jack@suse.cz> Message-Id: <BD33543C483B89AB+20240305061804.1186796-1-wentao@uniontech.com>
Diffstat (limited to 'fs/notify')
-rw-r--r--fs/notify/fanotify/fanotify.c6
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);