Re: [PATCH] vfs: make real_lookup do dentry revalidation with i_mutex held

[Christoph Hellwig <hch@infradead.org>]

Keeping i_mutes over do_revalidate seem fine from a first glance, but
can you please do it without rearranging the whole code?

Something like the tiny untested patch below should archive the same
thing:


Index: linux-2.6/fs/namei.c
===================================================================
--- linux-2.6.orig/fs/namei.c	2009-03-17 09:15:53.430978739 +0100
+++ linux-2.6/fs/namei.c	2009-03-17 09:16:19.553981306 +0100
@@ -512,12 +512,12 @@ out_unlock:
 	 * Uhhuh! Nasty case: the cache was re-populated while
 	 * we waited on the semaphore. Need to revalidate.
 	 */
-	mutex_unlock(&dir->i_mutex);
 	if (result->d_op && result->d_op->d_revalidate) {
 		result = do_revalidate(result, nd);
 		if (!result)
 			result = ERR_PTR(-ENOENT);
 	}
+	mutex_unlock(&dir->i_mutex);
 	return result;
 }