[PATCH] fs: synchronize_rcu when unregister_filesystem success not failure

[Milton Miller <miltonm@bga.com>]

While checking unregister_filesystem for saftey vs extra calls for
"ext4: register ext2 and ext3 alias after ext4" I realized that
the synchronize_rcu() was called on the error path but not on
the success path.

Should we call it in both?
Cc: stable (2.6.38)
Signed-off-by: Milton Miller <miltonm@bga.com>

Index: work.git/fs/filesystems.c
===================================================================
--- work.git.orig/fs/filesystems.c	2011-04-14 10:06:44.360068116 -0500
+++ work.git/fs/filesystems.c	2011-04-14 10:08:41.880061794 -0500
@@ -110,14 +110,13 @@ int unregister_filesystem(struct file_sy
 			*tmp = fs->next;
 			fs->next = NULL;
 			write_unlock(&file_systems_lock);
+			synchronize_rcu();
 			return 0;
 		}
 		tmp = &(*tmp)->next;
 	}
 	write_unlock(&file_systems_lock);
 
-	synchronize_rcu();
-
 	return -EINVAL;
 }