From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx0a-00364e01.pphosted.com (mx0a-00364e01.pphosted.com [148.163.135.74]) (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 108A735C1B2 for ; Wed, 23 Sep 2026 23:39:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=148.163.135.74 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790206746; cv=none; b=aRuewrunbaM/kQplFGxfe09NKC9JWl2diMsMFEfTS7EA+oSrh3wmzwlX5DyuK15OgtGf6Muspc6aLpXSYGP02jmHnlaGKhW48+1qnqOZOPMdHfpsGFnik/eJ8Ovr6wJ2SxQCgG4EnTx8nN0Eb8min+dIjg7JdGgRm71Bsj8veao= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790206746; c=relaxed/simple; bh=K3YyBaWo543pXNN5qq+I3FP7iBd5+S3J6soaWlcoDfA=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=Lh88i16Gw2sWvxeh8/hSERk/TNsm3/Ly7d2O9s9HdKFPcC4zBWYkIO7Ja3i4K3OpEm8Jxx8HbZG6+PYhlndp9oTZ37j/dGtvwcz+O3+E1vR0QdUvdc8KifP+XE/wHKeL5hHS6AwgGVQrgLFkMqhWnls+8mV5GO/UE6TtbueR8Aw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=columbia.edu; spf=pass smtp.mailfrom=columbia.edu; dkim=pass (2048-bit key) header.d=columbia.edu header.i=@columbia.edu header.b=hLztHIDR; dkim=pass (2048-bit key) header.d=columbia.edu header.i=@columbia.edu header.b=LCHy3tMh; arc=none smtp.client-ip=148.163.135.74 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=columbia.edu Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=columbia.edu Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=columbia.edu header.i=@columbia.edu header.b="hLztHIDR"; dkim=pass (2048-bit key) header.d=columbia.edu header.i=@columbia.edu header.b="LCHy3tMh" Received: from pps.filterd (m0167069.ppops.net [127.0.0.1]) by mx0a-00364e01.pphosted.com (8.18.1.11/8.18.1.11) with ESMTP id 68NNEDpK047002 for ; Wed, 23 Sep 2026 19:39:04 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=columbia.edu; h= cc:content-transfer-encoding:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to; s=pps01; bh=vK7o meZPmtdnE0KTnf60DcGTqHv0vNuINGT1nP6QP54=; b=hLztHIDRpVz/vKYKc0rl QKrD16ths0N5dqHrCem5e+EQL9IuSt0fqM22d65lCGvuXtM7Hvzl67AWqHVab/nB hAeepXwjTm8qUGuB5vIoAgW/T8gAzjF+Tt66hugUCVo045JJiG2yoeenlnS8XrMD Ayb6u+ENX1sV3bsOWsfVGL89eY6OrvjUirMLrwam62QWNmlhrOPBkudiTYj3+9rD sqWDAhNeQYKewpPcNcC30KQrdIackUvGt0/4TptOiJuO3SFzpsy37QnTCEzQWtpP p6cfRZhJ84rWESFb5KjgyXA4WKnRxFswOoMPE2HjsFGqTlXDef0P/FSR8UCe85Hu RQ== Received: from mail-pj1-f70.google.com (mail-pj1-f70.google.com [209.85.216.70]) by mx0a-00364e01.pphosted.com (PPS) with ESMTPS id 4gvhrem35s-1 (version=TLSv1.3 cipher=TLS_AES_128_GCM_SHA256 bits=128 verify=NOT) for ; Wed, 23 Sep 2026 19:39:04 -0400 (EDT) Received: by mail-pj1-f70.google.com with SMTP id 98e67ed59e1d1-38e54b6556aso1390915a91.2 for ; Wed, 23 Sep 2026 16:39:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=columbia.edu; s=lionmail; t=1790206743; x=1790811543; darn=vger.kernel.org; h=content-transfer-encoding:content-type:in-reply-to:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:from:to:cc:subject:date:message-id:reply-to :content-type; bh=vK7omeZPmtdnE0KTnf60DcGTqHv0vNuINGT1nP6QP54=; b=LCHy3tMhf4MYPrjFXKqKuIkYoNPNkfGDZiTy2NPgDkVt89j3j+MuKZqD5eq+GqiYEO swCB3DXmFp4HR5E5PpoBbuukdnDMxNXQQ86J4J9GYJ7g4ZjnMWQu2QbCRXcn6RBa0lVD r1rRTjHUPOLNtXd9vlrMyblRp69fhPPv+qQdVYwYg8XqqJ1IY6MhaihDOeHS2NjEzVrn GwibLeML5DZz9h4+Wt2WYELN7ZsbG7K795O/mUMLEzBFvziJYQv3hLHZje2YPPR1ax1R 2ytZSssu7G1I4pnTVa1NIPfOzuq4kYjdbPvfaQ4gWyrKZroMdGVUaSlWFaHvXJSx+egM aENA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1790206743; x=1790811543; h=content-transfer-encoding:content-type:in-reply-to:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to:content-type; bh=vK7omeZPmtdnE0KTnf60DcGTqHv0vNuINGT1nP6QP54=; b=nNBrsOdJO6p66hnwkJ5dPXQspc0xnlNspvmm/IYM2H9hRbTv+6aLezHC7/M2SfIha+ rZMjvzT4hVOX0mEDfBWIjBfdBXP61y/SU6kw+aKfjpwlufOZex8Sa7CFDqsxutNl8Fr1 Dni3bVI6Uf3oE2BHOF7WdreuHim9EPzhRQ2zYSXYsMqJqyy2zPZcxo1c9/eUi3Cv4rVd QrnlyZam+jZjLupNwEGpz3LjYzuEAgy8wC6LorO5M3tnM38OJwo4Pp1/0VVj+k99tRok pzF3iMTRMXOFcQp5EpPbHS82xGqSiKZvyR4D75mvYwKl6IPekPDd6IDJ2jHjN3fYUJhj Vojg== X-Forwarded-Encrypted: i=1; AKwUvBx62ZIE+ShWtXne4lL1cKD0lZKG131cq9u18Fy+wQ2AoXssb36RfKHy32S2SsoRp8Nt1mdmNQrt56H2VUQ=@vger.kernel.org X-Gm-Message-State: AFuF++kvaZxiLa2A+uaD3kFAaVDKtHmLkP84VOqOzn28y00eyPlAfd71 ele9Q1E//SjQzc5ZlShmLa7dxHLRejyrzV5pnE3SZiGd3jK/CMBcWRoU44J+g1Ff56Q7jIPCxD1 4WutLeHFRBAvm7uWgzRVHrf0jwT2W8XZG0NgoDuLrIAwbcTPbNkSMLLQdyeC4HA== X-Gm-Gg: AYBFou34ZgRGoBSGNN6d4esJTsekm++bSw5bbhCBg3A/oxDoqN1Kqc3ApCVsYwMYvsI 5YuzNYy8nbvtA/3B91G3Z89yapCMvFtodf/gmTT8YtOACqXahzMd7v1oTHgcb9hf3PbaC6TEzVq uedvYIpyMtgL6Du+DAYUV0DC5l7US119DAQcdzcM9dJ6NNIXLHKlzmBSgRCM52EKBqhviqJsklg Yi1ILX2rjuzJvmDMzAKvZsC6xI+g+5QYkrDJOMypH0q/RlYBffOIamPbhDvaU3mL2lPHTTF0s3M PMbxi/XASedRk9KD4vjNOKZSdZt5Q9iEwLJPm2ZavugGTuvjLTYaQ1iVH0BYuVF9JQPF4SdTSH1 zBT02J+eXIzZSifoueVEfndgNZCKQmr2C6hkdHcnAnaQI1yZAsA== X-Received: by 2002:a17:90b:270d:b0:39e:6c6a:4b6b with SMTP id 98e67ed59e1d1-3a098e006d2mr535113a91.53.1790206743526; Wed, 23 Sep 2026 16:39:03 -0700 (PDT) X-Received: by 2002:a17:90b:270d:b0:39e:6c6a:4b6b with SMTP id 98e67ed59e1d1-3a098e006d2mr535099a91.53.1790206743134; Wed, 23 Sep 2026 16:39:03 -0700 (PDT) Received: from [172.16.0.184] (RED-LION-HO.car2.Seattle1.Level3.net. [4.53.155.98]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-3a0974ec711sm1248285a91.6.2026.09.23.16.39.02 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 23 Sep 2026 16:39:02 -0700 (PDT) Message-ID: <4e25b2c3-7030-4084-8202-beeea9f9e026@columbia.edu> Date: Wed, 23 Sep 2026 16:39:01 -0700 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 v4 6/8] block: don't fall back to buffered I/O for atomic writes To: John Garry , Jens Axboe , Christoph Hellwig , Johannes Thumshirn , Luis Chamberlain , Hannes Reinecke , "Matthew Wilcox (Oracle)" , Christian Brauner , "Darrick J. Wong" , Keith Busch , "Martin K. Petersen" Cc: Shin'ichiro Kawasaki , linux-block@vger.kernel.org, linux-kernel@vger.kernel.org References: <20260921-blkdev-fixes-v4-0-e2801f71ede9@columbia.edu> <20260921-blkdev-fixes-v4-6-e2801f71ede9@columbia.edu> Content-Language: en-US From: Tal Zussman In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Proofpoint-ORIG-GUID: l8kjk3voN_vtWLRxMCLipmN5-pWCaKFm X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwOTIzMDA5NyBTYWx0ZWRfX56rh0J7X78Er BU7HWQF2qoFxhIKfl9Eknh7hOYqaLaETXxiQNz2v1R9GTZEgdvlPQPlZMTPcV39o+o3G6xI2Uhg wvqc04Dm5m4lDbkT1EXqb65xgicFUMPh1muekI7TGxgh7IlsxlhRRGbR5RvoIBq6VXzAhvuKVpJ PDMYVAJppWBw9CVvlVNqwwyhy7sW8fKCkyClYm417Tw1VBNzl/CZdHG6fr0RiP0RiVqkgn7rfZS WgHN1CebnE7mHL2gkPVkycDPUSZdtj1A494DKhD/clvPJBIbT2rN2Z/rnTGOcjt6gVM6fFpfRf6 ME2DFnpU4xyftNPypIF7dgSWygT1KDSgEg3AbjVaOwPqkdpGCdg4ZqgL2pzMrsCY8lLOaqVpQb5 nKNPn/+9nqHXw9DKfRWu0I/RhNIoudQi8HpuUHvoK3dsJN5W0KID30EkTs2h7ujgfvn2Ub1UqDV +Fz9WhpKWQEvEdmU5jw== X-Proofpoint-Spam-Info: AW1haW4tMjYwOTIzMDA5NyBTYWx0ZWRfX95UTKJRoGYxU RvDeTNAjQ9LanghF8A6FemTInmycCMkZ02uGhJC0wSW6pzGUt1Ff+F9DYwTiCJeFQYfKb3hfMLB ZqVisiP/DtnyTZuRwrUsQtKK3F+9HO9CqYGQa0NNAq1zXWfPXOQn X-Authority-Analysis: v=2.4 cv=J/A/fwnS c=1 sm=1 tr=0 ts=6ab46318 cx=c_pps a=0uOsjrqzRL749jD1oC5vDA==:117 a=6aZ3Ysb2zzbY2sELL/OBJw==:17 a=IkcTkHD0fZMA:10 a=VdqzKS8jKosA:10 a=x7bEGLp0ZPQA:10 a=A0y_DWxS2BwA:10 a=VkNPw1HP01LnGYTKEx00:22 a=Da8U98TiO7q1upZEImrf:22 a=JR4YdQiviy7OQf72WyZ1:22 a=HS0_KwlRLz3-zwHAltEA:9 a=QEXdDO2ut3YA:10 a=mQ_c8vxmzFEMiUWkPHU9:22 X-Proofpoint-GUID: l8kjk3voN_vtWLRxMCLipmN5-pWCaKFm X-Proofpoint-Virus-Version: vendor=nai engine=6900 definitions=11914 signatures=596817 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 impostorscore=10 malwarescore=0 phishscore=0 suspectscore=0 lowpriorityscore=10 bulkscore=10 spamscore=0 clxscore=1015 adultscore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2609040000 definitions=main-2609230097 On 9/22/26 6:05 AM, John Garry wrote: > On 9/22/26 03:54, Tal Zussman wrote: > > Note that I still think that you can add an IOCB_ATOMIC check in > iomap_file_buffered_write() (until it does handle IOCB_ATOMIC). > Will do! > Reviewed-by: John Garry > Thanks! >> --- >> block/fops.c | 5 +++-- >> 1 file changed, 3 insertions(+), 2 deletions(-) >> >> diff --git a/block/fops.c b/block/fops.c >> index 90777e8a9a6c..7f23778f6b81 100644 >> --- a/block/fops.c >> +++ b/block/fops.c >> @@ -766,10 +766,11 @@ static ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from) >> if (iocb->ki_flags & IOCB_DIRECT) { >> ret = blkdev_direct_write(iocb, from); >> if (ret >= 0 && iov_iter_count(from)) { >> - if (iocb->ki_flags & IOCB_NOWAIT) { >> + if (iocb->ki_flags & (IOCB_NOWAIT | IOCB_ATOMIC)) { >> /* >> * The buffered fallback blocks on i_rwsem and >> - * on writeback of the data it copied: return >> + * on writeback of the data it copied, and >> + * can't provide torn-write protection: return >> * the short direct write instead and let the >> * caller retry. >> */ >> >