[PATCH] mqueue: nested locking annotation

Fix http://bugzilla.kernel.org/show_bug.cgi?id=8130

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 2 insertions, 1 deletions

diff --git a/ipc/mqueue.c b/ipc/mqueue.c
index 0b5ecbe5f045..554ac368be79 100644
--- a/ipc/mqueue.c
+++ b/ipc/mqueue.c
@@ -731,7 +731,8 @@ asmlinkage long sys_mq_unlink(const char __user *u_name)
         if (IS_ERR(name))
                 return PTR_ERR(name);
 
-        mutex_lock(&mqueue_mnt->mnt_root->d_inode->i_mutex);
+        mutex_lock_nested(&mqueue_mnt->mnt_root->d_inode->i_mutex,
+                        I_MUTEX_PARENT);
         dentry = lookup_one_len(name, mqueue_mnt->mnt_root, strlen(name));
         if (IS_ERR(dentry)) {
                 err = PTR_ERR(dentry);