fanotify: Release SRCU lock when waiting for userspace response

[mirror_ubuntu-artful-kernel.git] / fs / notify / fanotify / fanotify.c

diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c
index ec80a51cbb3dae03915af1867729a28d3963336f..461c21ebebebc31af119e2400086036a8a1fa26a 100644 (file)
--- a/fs/notify/fanotify/fanotify.c
+++ b/fs/notify/fanotify/fanotify.c
@@ -57,14 +57,26 @@ static int fanotify_merge(struct list_head *list, struct fsnotify_event *event)
 
 #ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
 static int fanotify_get_response(struct fsnotify_group *group,
-                                struct fanotify_perm_event_info *event)
+                                struct fanotify_perm_event_info *event,
+                                struct fsnotify_iter_info *iter_info)
 {
        int ret;
 
        pr_debug("%s: group=%p event=%p\n", __func__, group, event);
 
+       /*
+        * fsnotify_prepare_user_wait() fails if we race with mark deletion.
+        * Just let the operation pass in that case.
+        */
+       if (!fsnotify_prepare_user_wait(iter_info)) {
+               event->response = FAN_ALLOW;
+               goto out;
+       }
+
        wait_event(group->fanotify_data.access_waitq, event->response);
 
+       fsnotify_finish_user_wait(iter_info);
+out:
        /* userspace responded, convert to something usable */
        switch (event->response) {
        case FAN_ALLOW:
@@ -216,7 +228,8 @@ static int fanotify_handle_event(struct fsnotify_group *group,
 
 #ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
        if (mask & FAN_ALL_PERM_EVENTS) {
-               ret = fanotify_get_response(group, FANOTIFY_PE(fsn_event));
+               ret = fanotify_get_response(group, FANOTIFY_PE(fsn_event),
+                                           iter_info);
                fsnotify_destroy_event(group, fsn_event);
        }
 #endif