Ocfs2 devel - Jul 2008 - [PATCH 7/7] fs/ocfs2/file.c: Release mutex in error handling code

From: Julia Lawall <julia at diku.dk>

The mutex is released on a successful return, so it would seem that it
should be released on an error return as well.

The semantic patch finds this problem is as follows:
(http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@@
expression l;
@@

mutex_lock(l);
... when != mutex_unlock(l)
    when any
    when strict
(
if (...) { ... when != mutex_unlock(l)
+   mutex_unlock(l);
    return ...;
}
|
mutex_unlock(l);
)
// </smpl>

Signed-off-by: Julia Lawall <julia at diku.dk>

---
diff -u -p a/fs/ocfs2/file.c b/fs/ocfs2/file.c
--- a/fs/ocfs2/file.c
+++ b/fs/ocfs2/file.c
@@ -1766,8 +1766,8 @@ out_inode_unlock:
 out_rw_unlock:
 	ocfs2_rw_unlock(inode, 1);
 
-	mutex_unlock(&inode->i_mutex);
 out:
+	mutex_unlock(&inode->i_mutex);
 	return ret;
 }

On Mon, Jul 21, 2008 at 09:59:15AM +0200, Julia Lawall
wrote:
> From: Julia Lawall <julia at diku.dk>
> 
> The mutex is released on a successful return, so it would seem that it
> should be released on an error return as well.
	This patch looks right to me.  Mark?

Joel


-- 

"If you are ever in doubt as to whether or not to kiss a pretty girl, 
 give her the benefit of the doubt"
                                        -Thomas Carlyle

Joel Becker
Principal Software Developer
Oracle
E-mail: joel.becker at oracle.com
Phone: (650) 506-8127