From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754654Ab2L1TR6 (ORCPT ); Fri, 28 Dec 2012 14:17:58 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:55108 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754586Ab2L1TRq (ORCPT ); Fri, 28 Dec 2012 14:17:46 -0500 Message-Id: <20121228190358.888854459@decadent.org.uk> User-Agent: quilt/0.60-1 Date: Fri, 28 Dec 2012 20:05:53 +0100 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, NeilBrown , Trond Myklebust , Al Viro Subject: [ 143/173] vfs: d_obtain_alias() needs to use "/" as default name. In-Reply-To: <20121228190330.025298996@decadent.org.uk> X-SA-Exim-Connect-IP: 151.217.219.220 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: NeilBrown commit b911a6bdeef5848c468597d040e3407e0aee04ce upstream. NFS appears to use d_obtain_alias() to create the root dentry rather than d_make_root. This can cause 'prepend_path()' to complain that the root has a weird name if an NFS filesystem is lazily unmounted. e.g. if "/mnt" is an NFS mount then { cd /mnt; umount -l /mnt ; ls -l /proc/self/cwd; } will cause a WARN message like WARNING: at /home/git/linux/fs/dcache.c:2624 prepend_path+0x1d7/0x1e0() ... Root dentry has weird name <> to appear in kernel logs. So change d_obtain_alias() to use "/" rather than "" as the anonymous name. Signed-off-by: NeilBrown Cc: Trond Myklebust Cc: Al Viro Signed-off-by: Andrew Morton Signed-off-by: Al Viro [bwh: Backported to 3.2: use named initialisers instead of QSTR_INIT()] Signed-off-by: Ben Hutchings --- fs/dcache.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/fs/dcache.c +++ b/fs/dcache.c @@ -1492,7 +1492,7 @@ static struct dentry * d_find_any_alias( */ struct dentry *d_obtain_alias(struct inode *inode) { - static const struct qstr anonstring = { .name = "" }; + static const struct qstr anonstring = { .name = "/", .len = 1 }; struct dentry *tmp; struct dentry *res;