Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757736Ab0BLEwg (ORCPT ); Thu, 11 Feb 2010 23:52:36 -0500 Received: from TYO201.gate.nec.co.jp ([202.32.8.193]:51892 "EHLO tyo201.gate.nec.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756035Ab0BLEwd (ORCPT ); Thu, 11 Feb 2010 23:52:33 -0500 Message-ID: <4B74DE40.5030401@ce.jp.nec.com> Date: Fri, 12 Feb 2010 13:51:12 +0900 From: "Jun'ichi Nomura" User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.5) Gecko/20091209 Fedora/3.0-4.fc12 Thunderbird/3.0 MIME-Version: 1.0 To: Andrew Morton , Al Viro CC: Valdis.Kletnieks@vt.edu, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-s390@vger.kernel.org, linux-next@vger.kernel.org, Heiko Carstens Subject: Re: mmotm 2010-02-10 - BUG at fs/dcache.c:677! References: <201002110043.o1B0hKxW008835@imap1.linux-foundation.org> <8576.1265942657@localhost> <20100211191427.6ff9aec6.akpm@linux-foundation.org> In-Reply-To: <20100211191427.6ff9aec6.akpm@linux-foundation.org> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2215 Lines: 57 (02/12/10 12:14), Andrew Morton wrote: > On Thu, 11 Feb 2010 21:44:17 -0500 Valdis.Kletnieks@vt.edu wrote: > >> On Wed, 10 Feb 2010 16:17:41 PST, akpm@linux-foundation.org said: >>> The mm-of-the-moment snapshot 2010-02-10-16-17 has been uploaded to >>> >>> http://userweb.kernel.org/~akpm/mmotm/ >> >> Hit this at shutdown. ext4 filesystems. Brought it up to single-user >> mode, then 'shutdown -h now'. >> >> [ 58.311786] ------------[ cut here ]------------ >> [ 58.312261] kernel BUG at fs/dcache.c:677! ... > Yeah, Sachin reported that against linux-next too (I think - need to > check the exact line numbers): > http://permalink.gmane.org/gmane.linux.file-systems/38148 > > It seems to have been met with shrugs thus far. According to the Sachin's report: > While running hackbench against today's next-20100208 (9056d31..) > on a s390 box, came across following BUG. ... > Did not observe this with next-20100205. Also there doesn't seem to be > any patches applied to this code after the last release. So not > sure what could have caused this. Corresponding code is : So the bug seems introduced between next-20100205 and next-20100208. Isn't this change missing the equivalent of "dput(old)"? In patch-v2.6.33-rc7-next-20100208: > diff --git a/fs/namei.c b/fs/namei.c > index 94a5e60..a056dad 100644 > --- a/fs/namei.c > +++ b/fs/namei.c > @@ -689,33 +689,17 @@ static __always_inline void follow_dotdot(struct nameidata *nd) ... > - spin_lock(&dcache_lock); > if (nd->path.dentry != nd->path.mnt->mnt_root) { > - nd->path.dentry = dget(nd->path.dentry->d_parent); > - spin_unlock(&dcache_lock); > - dput(old); > + /* rare case of legitimate dget_parent()... */ > + nd->path.dentry = dget_parent(nd->path.dentry); > break; > } -- Jun'ichi Nomura, NEC Corporation -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/