From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx3.molgen.mpg.de (mx3.molgen.mpg.de [141.14.17.11]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A50251805E; Sun, 15 Jun 2025 09:21:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=141.14.17.11 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749979290; cv=none; b=MFBNwbX6X2v7ezxyv3M6Qwg2jIL3gGf+J6VwStxTbtjCuZx63WK/CGQW3lGUXExEOfaLJpIFE8D+h54LKh9uk4xKsU+Q4sz5zfmzEZag361d4+fsuqVpsHWkmXSJL9W3okmam4qmrdiTujhHBOaXnrIIitlr45gwNP2kEUloQOQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749979290; c=relaxed/simple; bh=NYRg38DlRuC27rhN7ZN90EJBRZhZEvpPBUvP4s6LemE=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=KOKA1VzNYU3wXMRQWzzFHvUHOQvkaQLSPHJjoYJeEBhjLjgRmRG7ElIEMxbFFNh+ZIf88YhG+2UIChW9jZNsPi9tBnUYrqn/ApULN8vnepfwBdGALV9z5ZA6E4V+P4ObXBWIjZS4M67dObBVBpeAMHVTgmSg+bq2Mk4IbJBhnU0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=molgen.mpg.de; spf=pass smtp.mailfrom=molgen.mpg.de; arc=none smtp.client-ip=141.14.17.11 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=molgen.mpg.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=molgen.mpg.de Received: from [192.168.2.111] (p5b13a758.dip0.t-ipconnect.de [91.19.167.88]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: pmenzel) by mx.molgen.mpg.de (Postfix) with ESMTPSA id 2790D61E64787; Sun, 15 Jun 2025 11:20:33 +0200 (CEST) Message-ID: Date: Sun, 15 Jun 2025 11:20:31 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] md/raid1,raid10: fix IO handle for REQ_NOWAIT To: Zheng Qixing , Zheng Qixing Cc: song@kernel.org, yukuai3@huawei.com, linux-raid@vger.kernel.org, linux-kernel@vger.kernel.org, yi.zhang@huawei.com, yangerkun@huawei.com References: <20250612132141.358202-1-zhengqixing@huaweicloud.com> <34f22e12-62e7-4e0c-9fd2-b4bacd95a4fc@huawei.com> Content-Language: en-US From: Paul Menzel In-Reply-To: <34f22e12-62e7-4e0c-9fd2-b4bacd95a4fc@huawei.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Dear Zheng, Am 14.06.25 um 08:50 schrieb Zheng Qixing: > Please disregard the previous reply email, as it contained garbled text. Thank you for noticing this, and resending. > 在 2025/6/13 16:02, Paul Menzel 写道: >> Am 12.06.25 um 15:21 schrieb Zheng Qixing: >>> From: Zheng Qixing >>> >>> IO with REQ_NOWAIT should not set R1BIO_Uptodate when it fails, >>> and bad blocks should also be cleared when REQ_NOWAIT IO succeeds. >> >> It’d be great if you could add an explanation for the *should*. Why >> should it not be done? >> >> Do you have a reproducer for this? > > If we set R1BIO_Uptodate when IO with REQ_NOWAIT fails, the request will > return a success. Understood. So no command to check for this automatically on a test system. For the explanation, I guess my problem is, that I was not familiar with REQ_NOWAIT, which means that it fails for blocked IO. (If I am correct.) > But actually it should return BLK_STS_IOERR or BLK_STS_AGAIN, right? Sorry, I do not know. Hopefully the maintainers can answer this. >>> Fixes: 9f346f7d4ea7 ("md/raid1,raid10: don't handle IO error for REQ_RAHEAD and REQ_NOWAIT") >>> Signed-off-by: Zheng Qixing >>> --- >>>   drivers/md/raid1.c  | 11 ++++++----- >>>   drivers/md/raid10.c |  9 +++++---- >>>   2 files changed, 11 insertions(+), 9 deletions(-) >>> >>> diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c >>> index 19c5a0ce5a40..a1cddd24b178 100644 >>> --- a/drivers/md/raid1.c >>> +++ b/drivers/md/raid1.c >>> @@ -455,13 +455,13 @@ static void raid1_end_write_request(struct bio *bio) >>>       struct md_rdev *rdev = conf->mirrors[mirror].rdev; >>>       sector_t lo = r1_bio->sector; >>>       sector_t hi = r1_bio->sector + r1_bio->sectors; >>> -    bool ignore_error = !raid1_should_handle_error(bio) || >>> -        (bio->bi_status && bio_op(bio) == REQ_OP_DISCARD); >>> +    bool discard_error = bio->bi_status && bio_op(bio) == REQ_OP_DISCARD; >> >> Excuse my ignorance. What is the difference between ignore and discard? > > REQ_OP_DISCARD is a operation type while REQ_NOWAIT is just a request flag. > > These two can be combined together. IO with REQ_NOWAIT can fail early, even > though the storage medium is fine. So, we better handle this type of > error specially. > > I hope this clarifies your doubts. Sorry about being not clear enough. My question was more about changing the naming of the variable. >>>       /* >>>        * 'one mirror IO has finished' event handler: >>>        */ >>> -    if (bio->bi_status && !ignore_error) { >>> +    if (bio->bi_status && !discard_error && >>> +        raid1_should_handle_error(bio)) { >>>           set_bit(WriteErrorSeen,    &rdev->flags); >>>           if (!test_and_set_bit(WantReplacement, &rdev->flags)) >>>               set_bit(MD_RECOVERY_NEEDED, & >>> @@ -507,12 +507,13 @@ static void raid1_end_write_request(struct bio *bio) >>>            * check this here. >>>            */ >>>           if (test_bit(In_sync, &rdev->flags) && >>> -            !test_bit(Faulty, &rdev->flags)) >>> +            !test_bit(Faulty, &rdev->flags) && >>> +            (!bio->bi_status || discard_error)) >>>               set_bit(R1BIO_Uptodate, &r1_bio->state); >>>             /* Maybe we can clear some bad blocks. */ >>>           if (rdev_has_badblock(rdev, r1_bio->sector, r1_bio->sectors) && >>> -            !ignore_error) { >>> +            !bio->bi_status) { >>>               r1_bio->bios[mirror] = IO_MADE_GOOD; >>>               set_bit(R1BIO_MadeGood, &r1_bio->state); >>>           } >>> diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c >>> index b74780af4c22..1848947b0a6d 100644 >>> --- a/drivers/md/raid10.c >>> +++ b/drivers/md/raid10.c >>> @@ -458,8 +458,8 @@ static void raid10_end_write_request(struct bio *bio) >>>       int slot, repl; >>>       struct md_rdev *rdev = NULL; >>>       struct bio *to_put = NULL; >>> -    bool ignore_error = !raid1_should_handle_error(bio) || >>> -        (bio->bi_status && bio_op(bio) == REQ_OP_DISCARD); >>> +    bool discard_error = bio->bi_status && bio_op(bio) == REQ_OP_DISCARD; >>> +    bool ignore_error = !raid1_should_handle_error(bio) || discard_error; >>>         dev = find_bio_disk(conf, r10_bio, bio, &slot, &repl); >>>   @@ -522,13 +522,14 @@ static void raid10_end_write_request(struct bio *bio) >>>            * check this here. >>>            */ >>>           if (test_bit(In_sync, &rdev->flags) && >>> -            !test_bit(Faulty, &rdev->flags)) >>> +            !test_bit(Faulty, &rdev->flags) && >>> +            (!bio->bi_status || discard_error)) >>>               set_bit(R10BIO_Uptodate, &r10_bio->state); >>>             /* Maybe we can clear some bad blocks. */ >>>           if (rdev_has_badblock(rdev, r10_bio->devs[slot].addr, >>>                         r10_bio->sectors) && >>> -            !ignore_error) { >>> +            !bio->bi_status) { >>>               bio_put(bio); >>>               if (repl) >>>                   r10_bio->devs[slot].repl_bio = IO_MADE_GOOD; Kind regards, Paul PS: As it’s two hunks only connected through REQ_NOWAIT, maybe make it two commits: one for raid1 and one for raid10? Feel free to ignore.