From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from va-2-27.ptr.blmpb.com (va-2-27.ptr.blmpb.com [209.127.231.27]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BCC8035AC16 for ; Mon, 27 Jul 2026 03:08:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.127.231.27 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785121685; cv=none; b=UPoEkNpA/FTgZYKl7eW9GvSIBokoE/JBvJIOh/rxU5HQuvILkbwKEkATXdoiUo4l1KUC9gaJFtZrPiIeytIxoROdocV2ukab2s6v9U5GPFKDTeE8s0GPe0n7wdxhDvFB55I40zUxpa6u2lCBAUk5/OEewEVLqTyxsEX0/KsQOoI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785121685; c=relaxed/simple; bh=v6TCFX5vQTg5Be2YWkM9MW3GwTDU0y5p0CvsuvWIqC0=; h=Date:In-Reply-To:Content-Type:To:Subject:Message-Id:Mime-Version: Cc:References:From; b=gaH43QjtS0ItJ2hTASNFl+h2EeiL1WvHrVRPNJN9PHVE5+QfFZI51kVLUPeVCK2jOAh02yY3XuknBcPdYp62g4PumiO+WEnPXVSaHMylbO8W2rWs2Suh07hfb/tP3joeQTnKqhoiyZUSS+tBh3WS1+tEeMmlhJS0qI4o0paMMsI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=fnnas.com; spf=pass smtp.mailfrom=fnnas.com; dkim=pass (2048-bit key) header.d=fnnas-com.20200927.dkim.feishu.cn header.i=@fnnas-com.20200927.dkim.feishu.cn header.b=GtxTmJFz; arc=none smtp.client-ip=209.127.231.27 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=fnnas.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=fnnas.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=fnnas-com.20200927.dkim.feishu.cn header.i=@fnnas-com.20200927.dkim.feishu.cn header.b="GtxTmJFz" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; s=s1; d=fnnas-com.20200927.dkim.feishu.cn; t=1785121678; h=from:subject:mime-version:from:date:message-id:subject:to:cc: reply-to:content-type:mime-version:in-reply-to:message-id; bh=2ZeeXXnxFXCOI5JTt/7J/yxSkqIrDzdjS4zB/M/O+Fw=; b=GtxTmJFzQm3/g2tazN62+Q6PZzvnfsf2lOhmBU7wgK3retRrgOp1y/t09SRMiy7YYtCHKh /y3FImf6v3Ec6ZpKMO03ACx8ZgjzP47lignNuQaZmaeiRYvCY7daa0Kdvs+8fNo06PIXuK 17E2WMvQbyRw5He+51myvok3eISyGsIk2vMZZKF6kfhUoo/pb7yHy92aaGaZmAQjiOE6dy d8zbGMGqIuD1CTcSnxbQ/6bEjFNX0IKMt2KaCT2gFLTbmQe+ZL7fR6ifqCystyGnWVLfKB JVVv0Bs5mMMClqySC+vU2gB5jT8D2fTnau+iB/Cb+kS57VdyH/00P5dDDM7dMQ== Date: Mon, 27 Jul 2026 11:07:53 +0800 X-Original-From: Chen Cheng In-Reply-To: <20260726185640.2222714-1-mykola@meshstor.io> Received: from [192.168.8.80] ([183.34.169.20]) by smtp.feishu.cn with ESMTPS; Mon, 27 Jul 2026 11:07:55 +0800 Content-Transfer-Encoding: quoted-printable User-Agent: Mozilla Thunderbird Content-Type: text/plain; charset=UTF-8 To: "Mykola Marzhan" Subject: Re: [PATCH v7 0/3] md/raid10: fix r10bio width mismatches across reshape Message-Id: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 Cc: , , "Yu Kuai" , "Song Liu" References: <20260711100352.425177-1-chencheng@fnnas.com> <20260726185640.2222714-1-mykola@meshstor.io> From: "Chen Cheng" X-Lms-Return-Path: =E5=9C=A8 2026/7/27 02:56, Mykola Marzhan =E5=86=99=E9=81=93: > Hi Cheng, >=20 > Independent confirmation of the bug this series fixes, in case more > evidence helps it land. >=20 > While running a KASAN campaign against the llbitmap reshape v2 series > (base 55b77337 =E2=80=94 unrelated to your fix) every raid10 grow under I= O hit > both faces of the width mismatch: >=20 > BUG: KASAN: slab-out-of-bounds in free_r10bio+0x97/0x110 > Read of size 8 at addr ffff888149044ec8 by task ksoftirqd/2/28 > free_r10bio+0x97/0x110 > raid10_end_write_request+0x260/0x500 > blk_update_request+0x18b/0x6b0 > Allocated by task 232: > mempool_alloc_noprof+0x108/0x1d0 > raid10_make_request+0x18b/0x1100 >=20 > BUG: KASAN: slab-out-of-bounds in raid10_make_request+0x214/0x1100 > Write of size 192 at addr ffff88814da7aa48 by task fio/460 > __asan_memset+0x23/0x50 > raid10_make_request+0x214/0x1100 >=20 > (192 bytes =3D 6 x sizeof(struct r10dev) memset into a 4-disk > allocation.) >=20 > 456 reports across 5 grow cycles (n2, 4->6 disks, four fio randwrite > jobs) on the plain base kernel. The mempool face matches your 2/3 > exactly: the 256 preallocated r10bios keep the old width, so any > allocation that dips into the reserve after the grow is a guaranteed > OOB write, not just a read. >=20 > The storm is dense enough that raid10 grow under IO is not testable > under KASAN at all right now =E2=80=94 which is how we ran into it, and w= hy > we would like to see this land. >=20 > We plan to run v7 through the same rig and will follow up with the > result. >=20 Hi Mykola: Thanks to let me know that, and welcome to report the result and if you=20 have any idea, welcome to discuss. thanks, Cheng. > Thanks, > Mykola