From 8c5544666c9d88046bfd60aa7d5fea5c6d3d59bd Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Tue, 8 Jan 2019 13:52:31 +0100 Subject: [PATCH] fanotify: Move locking inside get_one_event() get_one_event() has a single caller and that just locks notification_lock around the call. Move locking inside get_one_event() as that will make using ->response field for permission event state easier. Reviewed-by: Amir Goldstein Signed-off-by: Jan Kara --- fs/notify/fanotify/fanotify_user.c | 32 +++++++++++++------------------- 1 file changed, 13 insertions(+), 19 deletions(-) diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c index e47d2a7..121c84f 100644 --- a/fs/notify/fanotify/fanotify_user.c +++ b/fs/notify/fanotify/fanotify_user.c @@ -65,35 +65,32 @@ static int fanotify_event_info_len(struct fanotify_event *event) * Get an fsnotify notification event if one exists and is small * enough to fit in "count". Return an error pointer if the count * is not large enough. - * - * Called with the group->notification_lock held. */ static struct fsnotify_event *get_one_event(struct fsnotify_group *group, size_t count) { size_t event_size = FAN_EVENT_METADATA_LEN; - struct fanotify_event *event; - - assert_spin_locked(&group->notification_lock); + struct fsnotify_event *fsn_event = NULL; pr_debug("%s: group=%p count=%zd\n", __func__, group, count); + spin_lock(&group->notification_lock); if (fsnotify_notify_queue_is_empty(group)) - return NULL; + goto out; if (FAN_GROUP_FLAG(group, FAN_REPORT_FID)) { - event = FANOTIFY_E(fsnotify_peek_first_event(group)); - event_size += fanotify_event_info_len(event); + event_size += fanotify_event_info_len( + FANOTIFY_E(fsnotify_peek_first_event(group))); } - if (event_size > count) - return ERR_PTR(-EINVAL); - - /* - * Held the notification_lock the whole time, so this is the - * same event we peeked above - */ - return fsnotify_remove_first_event(group); + if (event_size > count) { + fsn_event = ERR_PTR(-EINVAL); + goto out; + } + fsn_event = fsnotify_remove_first_event(group); +out: + spin_unlock(&group->notification_lock); + return fsn_event; } static int create_fd(struct fsnotify_group *group, @@ -316,10 +313,7 @@ static ssize_t fanotify_read(struct file *file, char __user *buf, add_wait_queue(&group->notification_waitq, &wait); while (1) { - spin_lock(&group->notification_lock); kevent = get_one_event(group, count); - spin_unlock(&group->notification_lock); - if (IS_ERR(kevent)) { ret = PTR_ERR(kevent); break; -- 2.7.4