From: Mark Fasheh <mark.fasheh@oracle.com>
Date: Fri, 20 Oct 2006 21:55:54 +0000 (-0700)
Subject: configfs: mutex_lock_nested() fix
X-Git-Tag: v2.6.20-rc1~34^2~40^2~4^2~7
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=55ed16029d597622db8121270e687373b5e31722;p=linux-2.6

configfs: mutex_lock_nested() fix

configfs_unregister_subsystem() nests a pair of inode i_mutex acquisitions,
and thus needs annotation via mutex_lock_nested().

Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
---

diff --git a/fs/configfs/dir.c b/fs/configfs/dir.c
index 8a3b6a1a6a..452cfd1e78 100644
--- a/fs/configfs/dir.c
+++ b/fs/configfs/dir.c
@@ -1176,8 +1176,9 @@ void configfs_unregister_subsystem(struct configfs_subsystem *subsys)
 		return;
 	}
 
-	mutex_lock(&configfs_sb->s_root->d_inode->i_mutex);
-	mutex_lock(&dentry->d_inode->i_mutex);
+	mutex_lock_nested(&configfs_sb->s_root->d_inode->i_mutex,
+			  I_MUTEX_PARENT);
+	mutex_lock_nested(&dentry->d_inode->i_mutex, I_MUTEX_CHILD);
 	if (configfs_detach_prep(dentry)) {
 		printk(KERN_ERR "configfs: Tried to unregister non-empty subsystem!\n");
 	}