fsnotify: fsnotify_add_notify_event should return an event
Rather than the horrific void ** argument and such just to pass the
fanotify_merge event back to the caller of fsnotify_add_notify_event() have
those things return an event if it was different than the event suggusted to
be added.
Signed-off-by: Eric Paris <eparis@redhat.com>
diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c
index bbcfccd..f3c40c0 100644
--- a/fs/notify/fanotify/fanotify.c
+++ b/fs/notify/fanotify/fanotify.c
@@ -30,65 +30,58 @@
return false;
}
-/* Note, if we return an event in *arg that a reference is being held... */
-static int fanotify_merge(struct list_head *list,
- struct fsnotify_event *event,
- void **arg)
+/* and the list better be locked by something too! */
+static struct fsnotify_event *fanotify_merge(struct list_head *list,
+ struct fsnotify_event *event)
{
struct fsnotify_event_holder *test_holder;
- struct fsnotify_event *test_event;
+ struct fsnotify_event *test_event = NULL;
struct fsnotify_event *new_event;
- struct fsnotify_event **return_event = (struct fsnotify_event **)arg;
- int ret = 0;
pr_debug("%s: list=%p event=%p\n", __func__, list, event);
- *return_event = NULL;
-
- /* and the list better be locked by something too! */
list_for_each_entry_reverse(test_holder, list, event_list) {
- test_event = test_holder->event;
- if (should_merge(test_event, event)) {
- fsnotify_get_event(test_event);
- *return_event = test_event;
-
- ret = -EEXIST;
- /* if they are exactly the same we are done */
- if (test_event->mask == event->mask)
- goto out;
-
- /*
- * if the refcnt == 1 this is the only queue
- * for this event and so we can update the mask
- * in place.
- */
- if (atomic_read(&test_event->refcnt) == 1) {
- test_event->mask |= event->mask;
- goto out;
- }
-
- /* can't allocate memory, merge was no possible */
- new_event = fsnotify_clone_event(test_event);
- if (unlikely(!new_event)) {
- ret = 0;
- goto out;
- }
-
- /* we didn't return the test_event, so drop that ref */
- fsnotify_put_event(test_event);
- /* the reference we return on new_event is from clone */
- *return_event = new_event;
-
- /* build new event and replace it on the list */
- new_event->mask = (test_event->mask | event->mask);
- fsnotify_replace_event(test_holder, new_event);
-
+ if (should_merge(test_holder->event, event)) {
+ test_event = test_holder->event;
break;
}
}
-out:
- return ret;
+
+ if (!test_event)
+ return NULL;
+
+ fsnotify_get_event(test_event);
+
+ /* if they are exactly the same we are done */
+ if (test_event->mask == event->mask)
+ return test_event;
+
+ /*
+ * if the refcnt == 2 this is the only queue
+ * for this event and so we can update the mask
+ * in place.
+ */
+ if (atomic_read(&test_event->refcnt) == 2) {
+ test_event->mask |= event->mask;
+ return test_event;
+ }
+
+ new_event = fsnotify_clone_event(test_event);
+
+ /* done with test_event */
+ fsnotify_put_event(test_event);
+
+ /* couldn't allocate memory, merge was not possible */
+ if (unlikely(!new_event))
+ return ERR_PTR(-ENOMEM);
+
+ /* build new event and replace it on the list */
+ new_event->mask = (test_event->mask | event->mask);
+ fsnotify_replace_event(test_holder, new_event);
+
+ /* we hold a reference on new_event from clone_event */
+ return new_event;
}
#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
@@ -123,7 +116,7 @@
static int fanotify_handle_event(struct fsnotify_group *group, struct fsnotify_event *event)
{
- int ret;
+ int ret = 0;
struct fsnotify_event *notify_event = NULL;
BUILD_BUG_ON(FAN_ACCESS != FS_ACCESS);
@@ -138,13 +131,9 @@
pr_debug("%s: group=%p event=%p\n", __func__, group, event);
- ret = fsnotify_add_notify_event(group, event, NULL, fanotify_merge,
- (void **)¬ify_event);
- /* -EEXIST means this event was merged with another, not that it was an error */
- if (ret == -EEXIST)
- ret = 0;
- if (ret)
- goto out;
+ notify_event = fsnotify_add_notify_event(group, event, NULL, fanotify_merge);
+ if (IS_ERR(notify_event))
+ return PTR_ERR(notify_event);
#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
if (event->mask & FAN_ALL_PERM_EVENTS) {
@@ -155,9 +144,9 @@
}
#endif
-out:
if (notify_event)
fsnotify_put_event(notify_event);
+
return ret;
}