Upgrade to 4.4.50-rt62

[kvmfornfv.git] / kernel / fs / notify / fanotify / fanotify_user.c

diff --git a/kernel/fs/notify/fanotify/fanotify_user.c b/kernel/fs/notify/fanotify/fanotify_user.c
index 8e8e6bc..a643138 100644 (file)
--- a/kernel/fs/notify/fanotify/fanotify_user.c
+++ b/kernel/fs/notify/fanotify/fanotify_user.c
@@ -358,16 +358,20 @@ static int fanotify_release(struct inode *ignored, struct file *file)
 
 #ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
        struct fanotify_perm_event_info *event, *next;
+       struct fsnotify_event *fsn_event;
 
        /*
-        * There may be still new events arriving in the notification queue
-        * but since userspace cannot use fanotify fd anymore, no event can
-        * enter or leave access_list by now.
+        * Stop new events from arriving in the notification queue. since
+        * userspace cannot use fanotify fd anymore, no event can enter or
+        * leave access_list by now either.
         */
-       spin_lock(&group->fanotify_data.access_lock);
-
-       atomic_inc(&group->fanotify_data.bypass_perm);
+       fsnotify_group_stop_queueing(group);
 
+       /*
+        * Process all permission events on access_list and notification queue
+        * and simulate reply from userspace.
+        */
+       spin_lock(&group->fanotify_data.access_lock);
        list_for_each_entry_safe(event, next, &group->fanotify_data.access_list,
                                 fae.fse.list) {
                pr_debug("%s: found group=%p event=%p\n", __func__, group,
@@ -379,12 +383,21 @@ static int fanotify_release(struct inode *ignored, struct file *file)
        spin_unlock(&group->fanotify_data.access_lock);
 
        /*
-        * Since bypass_perm is set, newly queued events will not wait for
-        * access response. Wake up the already sleeping ones now.
-        * synchronize_srcu() in fsnotify_destroy_group() will wait for all
-        * processes sleeping in fanotify_handle_event() waiting for access
-        * response and thus also for all permission events to be freed.
+        * Destroy all non-permission events. For permission events just
+        * dequeue them and set the response. They will be freed once the
+        * response is consumed and fanotify_get_response() returns.
         */
+       mutex_lock(&group->notification_mutex);
+       while (!fsnotify_notify_queue_is_empty(group)) {
+               fsn_event = fsnotify_remove_first_event(group);
+               if (!(fsn_event->mask & FAN_ALL_PERM_EVENTS))
+                       fsnotify_destroy_event(group, fsn_event);
+               else
+                       FANOTIFY_PE(fsn_event)->response = FAN_ALLOW;
+       }
+       mutex_unlock(&group->notification_mutex);
+
+       /* Response for all permission events it set, wakeup waiters */
        wake_up(&group->fanotify_data.access_waitq);
 #endif
 
@@ -755,7 +768,6 @@ SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags)
        spin_lock_init(&group->fanotify_data.access_lock);
        init_waitqueue_head(&group->fanotify_data.access_waitq);
        INIT_LIST_HEAD(&group->fanotify_data.access_list);
-       atomic_set(&group->fanotify_data.bypass_perm, 0);
 #endif
        switch (flags & FAN_ALL_CLASS_BITS) {
        case FAN_CLASS_NOTIF: