From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-11.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C6D7BC433DB for ; Wed, 3 Feb 2021 22:07:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8184660234 for ; Wed, 3 Feb 2021 22:07:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232704AbhBCWHj (ORCPT ); Wed, 3 Feb 2021 17:07:39 -0500 Received: from mail.kernel.org ([198.145.29.99]:45980 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233054AbhBCWHb (ORCPT ); Wed, 3 Feb 2021 17:07:31 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 5C94764F7E; Wed, 3 Feb 2021 22:06:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1612390007; bh=UEWOIc7PN2IjGCBOFwALkVTAoKa3FvEWV2NY+0mKd9w=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=ZB4OsQUA1qZ1utmg/wOPBGQp5sqbCBTZQjMu8JPSn7QeAd0Nkc7ILmw+zJuLBMC3b ZpEx1m6woyZVxdbc0jZy1pXl6z8YODXJMcS/8see8/U0xXHzVReUEErdGqhI07s0Ni A+ZyS/CxHr4ImRUa04vs1eje1SKB5GMxJzX+rbOM= Date: Wed, 3 Feb 2021 23:06:45 +0100 From: Greg Kroah-Hartman To: Andres Freund Cc: io-uring@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org, Bijan Mottahedeh , Sasha Levin Subject: Re: [PATCH 5.4 103/142] Revert "block: end bio with BLK_STS_AGAIN in case of non-mq devs and REQ_NOWAIT" Message-ID: References: <20200601174037.904070960@linuxfoundation.org> <20200601174048.647302799@linuxfoundation.org> <20210203123729.3pfsakawrkoh6qpu@alap3.anarazel.de> <20210203212826.6esa5orgnworwel6@alap3.anarazel.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210203212826.6esa5orgnworwel6@alap3.anarazel.de> Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org On Wed, Feb 03, 2021 at 01:28:26PM -0800, Andres Freund wrote: > Hi, > > On 2021-02-03 14:03:09 +0100, Greg Kroah-Hartman wrote: > > > On v5.4.43-101-gbba91cdba612 this fails with > > > fio: io_u error on file /mnt/t2/test.0.0: Input/output error: write offset=0, buflen=4096 > > > fio: pid=734, err=5/file:io_u.c:1834, func=io_u error, error=Input/output error > > > > > > whereas previously it worked. libaio still works... > > > > > > I haven't checked which major kernel version fixed this again, but I did > > > verify that it's still broken in 5.4.94 and that 5.10.9 works. > > > > > > I would suspect it's > > > > > > commit 4503b7676a2e0abe69c2f2c0d8b03aec53f2f048 > > > Author: Jens Axboe > > > Date: 2020-06-01 10:00:27 -0600 > > > > > > io_uring: catch -EIO from buffered issue request failure > > > > > > -EIO bubbles up like -EAGAIN if we fail to allocate a request at the > > > lower level. Play it safe and treat it like -EAGAIN in terms of sync > > > retry, to avoid passing back an errant -EIO. > > > > > > Catch some of these early for block based file, as non-mq devices > > > generally do not support NOWAIT. That saves us some overhead by > > > not first trying, then retrying from async context. We can go straight > > > to async punt instead. > > > > > > Signed-off-by: Jens Axboe > > > > > > > > > which isn't in stable/linux-5.4.y > > > > Can you test that if the above commit is added, all works well again? > > It doesn't apply cleanly, I'll try to resolve the conflict. However, I > assume that the revert was for a concrete reason - but I can't quite > figure out what b0beb28097fa04177b3769f4bb7a0d0d9c4ae76e was concretely > solving, and whether reverting the revert in 5.4 would re-introduce a > different problem. > > commit b0beb28097fa04177b3769f4bb7a0d0d9c4ae76e (tag: block-5.7-2020-05-29, linux-block/block-5.7) > Author: Jens Axboe > Date: 2020-05-28 13:19:29 -0600 > > Revert "block: end bio with BLK_STS_AGAIN in case of non-mq devs and REQ_NOWAIT" > > This reverts commit c58c1f83436b501d45d4050fd1296d71a9760bcb. > > io_uring does do the right thing for this case, and we're still returning > -EAGAIN to userspace for the cases we don't support. Revert this change > to avoid doing endless spins of resubmits. > > Cc: stable@vger.kernel.org # v5.6 > Reported-by: Bijan Mottahedeh > Signed-off-by: Jens Axboe > > I suspect it just wasn't aimed at 5.4, and that's that, but I'm not > sure. In which case presumably reverting > bba91cdba612fbce4f8575c5d94d2b146fb83ea3 would be the right fix, not > backporting 4503b7676a2e0abe69c2f2c0d8b03aec53f2f048 et al. Ok, can you send a revert patch for this? But it would be good to get Jens to weigh in on this... thanks, greg k-h