From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 5201433C191 for ; Fri, 9 Jan 2026 14:05:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767967534; cv=none; b=SAiRJxP3g/2ibWk5hO3BYN285DRN3QnPb/VXchltrzRn4DWEnHws9XSsCGNbImPwMzhx4mUGtY0f50iYTv+zaryygqLajHArRSup37ioxhvp8MiQWXfnUyToc176sy0CB12ITJvBZoA2KfBTqdGWGOegU3pQgdb/GVKbpcjMYBg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767967534; c=relaxed/simple; bh=1sdUxxxMj6Te9VUMe441yvD/bJT+sFEfb52bL1MG9Ac=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=JewvNjEbCVNF4d1ilHP0Cd2xW4QXbGDPqvwrSjn4jqjUHBi6Z4AeP9aPdraNorf2BLDYrYxsiHHHDLg2F2fbeneKMW5jIDqKWc7xseo8NgFcatBxv4qnqZIwaFiX4qSw6taeA/BtT4952502huHPUfaTknJsk2BbYc4DF28icmU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=fiqpzWaT; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="fiqpzWaT" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1767967532; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=b3VglsdfHUODaL3LC/M2IqYKAkFnhhVnuDB4v1OmwBk=; b=fiqpzWaT8E5pDBU7Kb0U6U8UY/QuqXm4lxQfO8GT2qvRpd6jXMiv5kL/1Svo+v3jvmOykK ML1MEoeEPIurvK1VnfnFPyph4/IayPmeA1As3x2+Kg7dUwE8+67z1RAh/AzKMEePYAhdh9 HmKa574ShBfj13gs2DciqyYgXjSEqCE= Received: from mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-592-O2MSAqv5NfuaIoXzaYFNQQ-1; Fri, 09 Jan 2026 09:05:29 -0500 X-MC-Unique: O2MSAqv5NfuaIoXzaYFNQQ-1 X-Mimecast-MFC-AGG-ID: O2MSAqv5NfuaIoXzaYFNQQ_1767967527 Received: from mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.93]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id AA4EC19560B7; Fri, 9 Jan 2026 14:05:26 +0000 (UTC) Received: from fedora (unknown [10.72.116.172]) by mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 763D31800995; Fri, 9 Jan 2026 14:05:17 +0000 (UTC) Date: Fri, 9 Jan 2026 22:05:12 +0800 From: Ming Lei To: Venkat Rao Bagalkote Cc: Christoph Hellwig , linux-block@vger.kernel.org, linux-scsi@vger.kernel.org, Jens Axboe , James.Bottomley@hansenpartnership.com, leonro@nvidia.com, kch@nvidia.com, LKML , Madhavan Srinivasan , riteshh@linux.ibm.com, ojaswin@linux.ibm.com Subject: Re: [next-20260108]kernel BUG at drivers/scsi/scsi_lib.c:1173! Message-ID: References: <9687cf2b-1f32-44e1-b58d-2492dc6e7185@linux.ibm.com> <7382f235-3e42-4b77-b18d-c38661816301@linux.ibm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.93 On Fri, Jan 09, 2026 at 07:26:01PM +0530, Venkat Rao Bagalkote wrote: > > On 09/01/26 6:28 pm, Ming Lei wrote: > > On Fri, Jan 09, 2026 at 05:51:15PM +0530, Venkat Rao Bagalkote wrote: > > > On 09/01/26 5:25 pm, Ming Lei wrote: > > > > On Fri, Jan 09, 2026 at 05:14:36PM +0530, Venkat Rao Bagalkote wrote: > > > > > On 09/01/26 12:19 pm, Ming Lei wrote: > > > > > > On Thu, Jan 08, 2026 at 09:56:39PM -0800, Christoph Hellwig wrote: > > > > > > > I've seen the same when running xfstests on xfs, and bisected it to: > > > > > > > > > > > > > > commit ee623c892aa59003fca173de0041abc2ccc2c72d > > > > > > > Author: Ming Lei > > > > > > > Date: Wed Dec 31 11:00:55 2025 +0800 > > > > > > > > > > > > > > block: use bvec iterator helper for bio_may_need_split() > > > > > > > > > > > > > Hi Christoph and Venkat Rao Bagalkote, > > > > > > > > > > > > Unfortunately I can't duplicate the issue in my environment, can you test > > > > > > the following patch? > > > > > > > > > > > > diff --git a/block/blk.h b/block/blk.h > > > > > > index 98f4dfd4ec75..980eef1f5690 100644 > > > > > > --- a/block/blk.h > > > > > > +++ b/block/blk.h > > > > > > @@ -380,7 +380,7 @@ static inline bool bio_may_need_split(struct bio *bio, > > > > > > return true; > > > > > > bv = __bvec_iter_bvec(bio->bi_io_vec, bio->bi_iter); > > > > > > - if (bio->bi_iter.bi_size > bv->bv_len) > > > > > > + if (bio->bi_iter.bi_size > bv->bv_len - bio->bi_iter.bi_bvec_done) > > > > > > return true; > > > > > > return bv->bv_len + bv->bv_offset > lim->max_fast_segment_size; > > > > > > } > > > > > Hello Ming, > > > > > > > > > > > > > > > This is not helping. I am hitting this issue, during kernel build itself. > > > > Can you confirm if it can fix the blktests ext4/056 first? > > > > > > > > If kernel building is running over new patched kernel, please provide the > > > > dmesg log. And if it is reproduciable, can you confirm if it can be fixed > > > > by reverting ee623c892aa59003 (block: use bvec iterator helper for bio_may_need_split())? > > > > > > Unfortunately, even with revert, build fails. > > > > > > > > > > > > commit c64b2ee9cddcb31546c8622ef018d344544a9388 (HEAD) > > > Author: Super User > > > Date:   Fri Jan 9 06:51:19 2026 -0600 > > > > > >     Revert "block: use bvec iterator helper for bio_may_need_split()" > > > > > >     This reverts commit ee623c892aa59003fca173de0041abc2ccc2c72d. > > OK, then your issue isn't related with the above change. > > > > Can you reproduce & collect dmesg log with the bad sg/rq/bio/bvec info by > > applying the attached debug patch? > > > > Also if possible, please collect your scsi queue's limit info before > > reproducing the issue: > > > > (cd /sys/block/$SD/queue && find . -type f -exec grep -aH . {} \;) > > Hello Ming, > > After applying the patch shared via attachment also, I see build failure. > > I have attached the kernel config file. > > > git diff > diff --git a/block/blk-mq-dma.c b/block/blk-mq-dma.c > index 752060d7261c..33c1b6a0a738 100644 > --- a/block/blk-mq-dma.c > +++ b/block/blk-mq-dma.c > @@ -4,8 +4,75 @@ >   */ >  #include >  #include > +#include >  #include "blk.h" Hi Venkat, Thanks for your test. But you didn't apply the whole debug patch in the following link: https://lore.kernel.org/linux-block/aWD7j3NR_m6EyZv1@fedora/ otherwise something like "=== __blk_rq_map_sg DEBUG DUMP ===" will be dumped in dmesg log. > > make -j 48 -s && make modules_install && make install > [ 5625.770436] ------------[ cut here ]------------ > [ 5625.770476] WARNING: block/blk-mq-dma.c:309 at If the whole debug patch is applied correctly, the above line number should have become 378 instead of original 309. Please re-apply the debug patch & reproduce again. Thanks, Ming