From: Denis V. Lunev <den@openvz.org>
Date: Mon, 11 Aug 2008 08:02:34 +0000 (+0400)
Subject: nfs: BUG_ON in nfs_follow_mountpoint
X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=44d5759d3fdad660f000ef319f0ec33a6ac6ae28;p=deliverable%2Flinux.git

nfs: BUG_ON in nfs_follow_mountpoint

Unfortunately, BUG_ON(IS_ROOT(dentry)) can happen inside
nfs_follow_mountpoint with NFS running Fedora 8 using a
specific setup.
https://bugzilla.redhat.com/show_bug.cgi?id=458622

So, the situation should be handled on NFS client gracefully.

Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Trond Myklebust <Trond.Myklebust@netapp.com>
CC: J. Bruce Fields <bfields@fieldses.org>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
---

diff --git a/fs/nfs/namespace.c b/fs/nfs/namespace.c
index d398775a3af5..64a288ee046d 100644
--- a/fs/nfs/namespace.c
+++ b/fs/nfs/namespace.c
@@ -105,7 +105,10 @@ static void * nfs_follow_mountpoint(struct dentry *dentry, struct nameidata *nd)
 
 	dprintk("--> nfs_follow_mountpoint()\n");
 
-	BUG_ON(IS_ROOT(dentry));
+	err = -ESTALE;
+	if (IS_ROOT(dentry))
+		goto out_err;
+
 	dprintk("%s: enter\n", __func__);
 	dput(nd->path.dentry);
 	nd->path.dentry = dget(dentry);