Merge branch 'for-linus' of git://git.infradead.org/users/eparis/notify

* 'for-linus' of git://git.infradead.org/users/eparis/notify:
  inotify: inotify_destroy_mark_entry could get called twice

3 files changed, 8 insertions, 29 deletions

diff --git a/fs/notify/inotify/inotify.h b/fs/notify/inotify/inotify.h
index ea2605a58b8a..f234f3a4c8ca 100644
--- a/fs/notify/inotify/inotify.h
+++ b/fs/notify/inotify/inotify.h
@@ -15,7 +15,8 @@ struct inotify_inode_mark_entry {
         int wd;
 };
 
-extern void inotify_destroy_mark_entry(struct fsnotify_mark_entry *entry, struct fsnotify_group *group);
+extern void inotify_ignored_and_remove_idr(struct fsnotify_mark_entry *entry,
+                                           struct fsnotify_group *group);
 extern void inotify_free_event_priv(struct fsnotify_event_private_data *event_priv);
 
 extern const struct fsnotify_ops inotify_fsnotify_ops;
diff --git a/fs/notify/inotify/inotify_fsnotify.c b/fs/notify/inotify/inotify_fsnotify.c
index 7ef75b83247e..47cd258fd24d 100644
--- a/fs/notify/inotify/inotify_fsnotify.c
+++ b/fs/notify/inotify/inotify_fsnotify.c
@@ -81,7 +81,7 @@ static int inotify_handle_event(struct fsnotify_group *group, struct fsnotify_ev
 
 static void inotify_freeing_mark(struct fsnotify_mark_entry *entry, struct fsnotify_group *group)
 {
-        inotify_destroy_mark_entry(entry, group);
+        inotify_ignored_and_remove_idr(entry, group);
 }
 
 static bool inotify_should_send_event(struct fsnotify_group *group, struct inode *inode, __u32 mask)
diff --git a/fs/notify/inotify/inotify_user.c b/fs/notify/inotify/inotify_user.c
index 982a412ac5bc..ff231ad23895 100644
--- a/fs/notify/inotify/inotify_user.c
+++ b/fs/notify/inotify/inotify_user.c
@@ -363,39 +363,17 @@ static int inotify_find_inode(const char __user *dirname, struct path *path, uns
 }
 
 /*
- * When, for whatever reason, inotify is done with a mark (or what used to be a
- * watch) we need to remove that watch from the idr and we need to send IN_IGNORED
- * for the given wd.
- *
- * There is a bit of recursion here.  The loop looks like:
- *      inotify_destroy_mark_entry -> fsnotify_destroy_mark_by_entry ->
- *      inotify_freeing_mark -> inotify_destory_mark_entry -> restart
- * But the loop is broken in 2 places.  fsnotify_destroy_mark_by_entry sets
- * entry->group = NULL before the call to inotify_freeing_mark, so the if (egroup)
- * test below will not call back to fsnotify again.  But even if that test wasn't
- * there this would still be safe since fsnotify_destroy_mark_by_entry() is
- * safe from recursion.
+ * Send IN_IGNORED for this wd, remove this wd from the idr, and drop the
+ * internal reference help on the mark because it is in the idr.
  */
-void inotify_destroy_mark_entry(struct fsnotify_mark_entry *entry, struct fsnotify_group *group)
+void inotify_ignored_and_remove_idr(struct fsnotify_mark_entry *entry,
+                                    struct fsnotify_group *group)
 {
         struct inotify_inode_mark_entry *ientry;
         struct inotify_event_private_data *event_priv;
         struct fsnotify_event_private_data *fsn_event_priv;
-        struct fsnotify_group *egroup;
         struct idr *idr;
 
-        spin_lock(&entry->lock);
-        egroup = entry->group;
-
-        /* if egroup we aren't really done and something might still send events
-         * for this inode, on the callback we'll send the IN_IGNORED */
-        if (egroup) {
-                spin_unlock(&entry->lock);
-                fsnotify_destroy_mark_by_entry(entry);
-                return;
-        }
-        spin_unlock(&entry->lock);
-
         ientry = container_of(entry, struct inotify_inode_mark_entry, fsn_entry);
 
         event_priv = kmem_cache_alloc(event_priv_cachep, GFP_KERNEL);
@@ -699,7 +677,7 @@ SYSCALL_DEFINE2(inotify_rm_watch, int, fd, __s32, wd)
         fsnotify_get_mark(entry);
         spin_unlock(&group->inotify_data.idr_lock);
 
-        inotify_destroy_mark_entry(entry, group);
+        fsnotify_destroy_mark_by_entry(entry);
         fsnotify_put_mark(entry);
 
 out: