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 <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>

diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
index e47d2a7..121c84f 100644 (file)
--- 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;