Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264915AbUISWv6 (ORCPT ); Sun, 19 Sep 2004 18:51:58 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264917AbUISWv6 (ORCPT ); Sun, 19 Sep 2004 18:51:58 -0400 Received: from pat.uio.no ([129.240.130.16]:1741 "EHLO pat.uio.no") by vger.kernel.org with ESMTP id S264915AbUISWvy (ORCPT ); Sun, 19 Sep 2004 18:51:54 -0400 Subject: Re: 2.6.9-rc2 hangs in posix_locks_deadlock From: Trond Myklebust To: "Vladimir B. Savkin" Cc: linux-kernel@vger.kernel.org In-Reply-To: <20040919203619.GA8618@tentacle.sectorb.msk.ru> References: <20040919160342.GA26409@tentacle.sectorb.msk.ru> <20040919200527.GA7184@tentacle.sectorb.msk.ru> <1095625531.7860.59.camel@lade.trondhjem.org> <20040919203619.GA8618@tentacle.sectorb.msk.ru> Content-Type: multipart/mixed; boundary="=-XlP7KfIK53H8lakgmCtB" Message-Id: <1095634303.7860.122.camel@lade.trondhjem.org> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.4.6 Date: Sun, 19 Sep 2004 15:51:43 -0700 X-MailScanner-Information: This message has been scanned for viruses/spam. Contact postmaster@uio.no if you have questions about this scanning X-UiO-MailScanner: No virus found X-UiO-Spam-info: not spam, SpamAssassin (score=0, required 12) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2597 Lines: 75 --=-XlP7KfIK53H8lakgmCtB Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable P=E5 su , 19/09/2004 klokka 13:36, skreiv Vladimir B. Savkin: > On Sun, Sep 19, 2004 at 01:32:08PM -0700, Trond Myklebust wrote: > > P? su , 19/09/2004 klokka 13:05, skreiv Vladimir B. Savkin: > > > >=20 > > > > Today I managed to see the output of Alt+SysRq+P on the > > > > hanged box and write down call trace (from screen, so it is incompl= ete). > > > >=20 > > > > EIP (c015da89) was in function posix_locks_deadlock, > > > > and the call trace was: > > > > __posix_lock_file > > > > fcntl_setlk Hmm... It appears that it is indeed possible for both leases and flocks to be on the global "blocked_list", so the appended check is *not* redundant. Since flocks in particular do not initialize fl_owner, I suspect that you might be seeing wierd loops that were previously being avoided due to the ->fl_pid checks... Cheers, Trond --=-XlP7KfIK53H8lakgmCtB Content-Disposition: inline; filename=fix_posix_locks_deadlock.dif Content-Type: text/plain; name=fix_posix_locks_deadlock.dif; charset=iso-8859-1 Content-Transfer-Encoding: 7bit [PATCH] fix posix_locks_deadlock(). "blocked_list" may contain both leases and flock locks. Since the latter in particular do not initialize the fl_owner field, we have to beware not to call posix_same_owner() on them. Signed-off-by: Trond Myklebust --- locks.c | 7 +++---- 1 files changed, 3 insertions(+), 4 deletions(-) Index: linux-2.6.9-rc2-up/fs/locks.c =================================================================== --- linux-2.6.9-rc2-up.orig/fs/locks.c 2004-09-19 13:55:33.680258334 -0700 +++ linux-2.6.9-rc2-up/fs/locks.c 2004-09-19 15:37:32.595634679 -0700 @@ -634,14 +634,13 @@ int posix_locks_deadlock(struct file_lock *caller_fl, struct file_lock *block_fl) { - struct list_head *tmp; + struct file_lock *fl; next_task: if (posix_same_owner(caller_fl, block_fl)) return 1; - list_for_each(tmp, &blocked_list) { - struct file_lock *fl = list_entry(tmp, struct file_lock, fl_link); - if (posix_same_owner(fl, block_fl)) { + list_for_each_entry(fl, &blocked_list, fl_link) { + if (IS_POSIX(fl) && posix_same_owner(fl, block_fl)) { fl = fl->fl_next; block_fl = fl; goto next_task; --=-XlP7KfIK53H8lakgmCtB-- - 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/