Bluetooth: Use macro for L2CAP hint mask on receiving config request

[pandora-kernel.git] / fs / pipe.c

diff --git a/fs/pipe.c b/fs/pipe.c
index 4af7aa5..13414ec 100644 (file)
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -37,6 +37,42 @@
  * -- Manfred Spraul <manfred@colorfullife.com> 2002-05-09
  */
 
+static void pipe_lock_nested(struct pipe_inode_info *pipe, int subclass)
+{
+       if (pipe->inode)
+               mutex_lock_nested(&pipe->inode->i_mutex, subclass);
+}
+
+void pipe_lock(struct pipe_inode_info *pipe)
+{
+       /*
+        * pipe_lock() nests non-pipe inode locks (for writing to a file)
+        */
+       pipe_lock_nested(pipe, I_MUTEX_PARENT);
+}
+EXPORT_SYMBOL(pipe_lock);
+
+void pipe_unlock(struct pipe_inode_info *pipe)
+{
+       if (pipe->inode)
+               mutex_unlock(&pipe->inode->i_mutex);
+}
+EXPORT_SYMBOL(pipe_unlock);
+
+void pipe_double_lock(struct pipe_inode_info *pipe1,
+                     struct pipe_inode_info *pipe2)
+{
+       BUG_ON(pipe1 == pipe2);
+
+       if (pipe1 < pipe2) {
+               pipe_lock_nested(pipe1, I_MUTEX_PARENT);
+               pipe_lock_nested(pipe2, I_MUTEX_CHILD);
+       } else {
+               pipe_lock_nested(pipe2, I_MUTEX_CHILD);
+               pipe_lock_nested(pipe1, I_MUTEX_PARENT);
+       }
+}
+
 /* Drop the inode semaphore and wait for a pipe event, atomically */
 void pipe_wait(struct pipe_inode_info *pipe)
 {
@@ -47,12 +83,10 @@ void pipe_wait(struct pipe_inode_info *pipe)
         * is considered a noninteractive wait:
         */
        prepare_to_wait(&pipe->wait, &wait, TASK_INTERRUPTIBLE);
-       if (pipe->inode)
-               mutex_unlock(&pipe->inode->i_mutex);
+       pipe_unlock(pipe);
        schedule();
        finish_wait(&pipe->wait, &wait);
-       if (pipe->inode)
-               mutex_lock(&pipe->inode->i_mutex);
+       pipe_lock(pipe);
 }
 
 static int