From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jens Axboe Subject: Re: [PATCH] Use list_splice for blk_abort_queue Date: Fri, 27 Feb 2009 12:56:27 +0100 Message-ID: <20090227115627.GD6602@kernel.dk> References: <20090227113706.3005518C786@pentland.suse.de> <20090227114057.GC6602@kernel.dk> <49A7D32B.4020100@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from brick.kernel.dk ([93.163.65.50]:33007 "EHLO kernel.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754815AbZB0L43 (ORCPT ); Fri, 27 Feb 2009 06:56:29 -0500 Content-Disposition: inline In-Reply-To: <49A7D32B.4020100@suse.de> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Hannes Reinecke Cc: James Bottomley , linux-scsi@vger.kernel.org On Fri, Feb 27 2009, Hannes Reinecke wrote: > Hi Jens, > > Jens Axboe wrote: >> On Fri, Feb 27 2009, Hannes Reinecke wrote: >>> blk_abort_queue takes the queue_lock with spinlock_irqsave and walks >>> the timer_list with list_for_each_entry_safe. Since a path to a SCSI >>> device just failed, the rport state is FC_PORTSTATE_BLOCKED. This >>> rport state triggers blk_add_timer(), which in turn calls >>> list_add_tail() to move the request to the end of timer_list. Thus, >>> the list_for_each_XXX loop never reaches the end of the timer_list. >>> By using list_splice_init() we're breaking the loop and process only >>> the requests present on the timeout_list when blk_abort_queue() is >>> called. >>> >>> Signed-off-by: Hannes Reinecke >>> Tested-by: Christof Schmitt >>> --- >>> block/blk-timeout.c | 5 ++++- >>> 1 files changed, 4 insertions(+), 1 deletions(-) >>> >>> diff --git a/block/blk-timeout.c b/block/blk-timeout.c >>> index a095353..67bcc3f 100644 >>> --- a/block/blk-timeout.c >>> +++ b/block/blk-timeout.c >>> @@ -209,12 +209,15 @@ void blk_abort_queue(struct request_queue *q) >>> { >>> unsigned long flags; >>> struct request *rq, *tmp; >>> + LIST_HEAD(list); >>> >>> spin_lock_irqsave(q->queue_lock, flags); >>> >>> elv_abort_queue(q); >>> >>> - list_for_each_entry_safe(rq, tmp, &q->timeout_list, timeout_list) >>> + list_splice_init(&q->timeout_list, &list); >>> + >>> + list_for_each_entry_safe(rq, tmp, &list, timeout_list) >>> blk_abort_request(rq); >>> >>> spin_unlock_irqrestore(q->queue_lock, flags); >>> -- >>> 1.5.3.2 >>> >> >> Hannes, this fix has been in mainline for about 10 days. >> > Ah, sorry. Missed that one. > I'm just about to catch up with unread mails, and you said something > about 'the original author should resend the patch'. > Which I did. Yep, I did say that. But after a few days I figured you were probably away or something, so I hacked up a changelog myself and put it in there. It was already tested good and it makes sense. -- Jens Axboe