From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from lithops.sigma-star.at ([195.201.40.130]) by casper.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1gKVeb-0004cL-5W for linux-um@lists.infradead.org; Wed, 07 Nov 2018 21:46:26 +0000 From: Richard Weinberger Subject: Re: Summary so far - ubd breakage in 4.20-rc1 Date: Wed, 07 Nov 2018 22:46:13 +0100 Message-ID: <4373302.HifUKF8Eoy@blindfold> In-Reply-To: References: <94397e9b-36a6-92b0-b074-ce3640cee00e@kot-begemot.co.uk> <2067083.opUWeOxqyK@blindfold> MIME-Version: 1.0 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-um" Errors-To: linux-um-bounces+geert=linux-m68k.org@lists.infradead.org To: Jens Axboe Cc: linux-um@lists.infradead.org, Anton Ivanov , hch@lst.de Am Mittwoch, 7. November 2018, 22:16:20 CET schrieb Jens Axboe: > >> Does the below help things? > >> > > > > It does! > > Anton, please give it also a try. > > OK good, it's definitely a bug, and given the symptoms, sounds like > THE bug in this case. Shall I send your fix as patch or do you want to? > >> diff --git a/arch/um/drivers/ubd_kern.c b/arch/um/drivers/ubd_kern.c > >> index 74c002ddc0ce..019bc4828e30 100644 > >> --- a/arch/um/drivers/ubd_kern.c > >> +++ b/arch/um/drivers/ubd_kern.c > >> @@ -1341,11 +1341,14 @@ static int ubd_queue_one_vec(struct blk_mq_hw_ctx *hctx, struct request *req, > >> static blk_status_t ubd_queue_rq(struct blk_mq_hw_ctx *hctx, > >> const struct blk_mq_queue_data *bd) > >> { > >> + struct ubd *ubd_dev = hctx->queue->queuedata; > >> struct request *req = bd->rq; > >> int ret = 0; > >> > >> blk_mq_start_request(req); > >> > >> + spin_lock_irq(&ubd_dev->lock); > >> + > > > > BTW: Why not irq_save/restore? > > You only need the save/restore versions if you're called with > interrupts already disabled (or may be), that's not the case > here. Hence we can use the faster versions. Got it! Thanks, //richard _______________________________________________ linux-um mailing list linux-um@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-um