pipe: don't use ->i_mutex

now it can be done - put mutex into pipe_inode_info, use it instead
of ->i_mutex

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 3 insertions, 2 deletions

diff --git a/fs/pipe.c b/fs/pipe.c
index abaa9234d27b..d4b97e4e37c5 100644
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -56,7 +56,7 @@ unsigned int pipe_min_size = PAGE_SIZE;
 static void pipe_lock_nested(struct pipe_inode_info *pipe, int subclass)
 {
 	if (pipe->inode)
-		mutex_lock_nested(&pipe->inode->i_mutex, subclass);
+		mutex_lock_nested(&pipe->mutex, subclass);
 }
 
 void pipe_lock(struct pipe_inode_info *pipe)
@@ -71,7 +71,7 @@ EXPORT_SYMBOL(pipe_lock);
 void pipe_unlock(struct pipe_inode_info *pipe)
 {
 	if (pipe->inode)
-		mutex_unlock(&pipe->inode->i_mutex);
+		mutex_unlock(&pipe->mutex);
 }
 EXPORT_SYMBOL(pipe_unlock);
 
@@ -777,6 +777,7 @@ struct pipe_inode_info * alloc_pipe_info(struct inode *inode)
 			pipe->r_counter = pipe->w_counter = 1;
 			pipe->inode = inode;
 			pipe->buffers = PIPE_DEF_BUFFERS;
+			mutex_init(&pipe->mutex);
 			return pipe;
 		}
 		kfree(pipe);