From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj1-f52.google.com (mail-pj1-f52.google.com [209.85.216.52]) (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 6541E364E96 for ; Fri, 21 Aug 2026 20:49:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.52 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787345366; cv=none; b=aptpryUp8rWCMs7J6PA1ZbqOEkYlTaib10/xc0f6gdx1+wWMRAf7GSPlx6YvE3sQ+6YlVcOQ38jCbGCMToDnbqGpaVuXtSEb7AjKRjgTaiVnP+IcSWxTKAPKRJ9sDZKvAKXTAolGU90RB481YBgg+SbxFT8MnNFl64vA3e/PKIE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787345366; c=relaxed/simple; bh=kqSSIILac7u1pKPNOUJ/EuEid7Kx/XiiY4lOm0AmR9M=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=D84cr3R21dHleTv1OZXpxgf3kERjPYnQywBnFW5HNVKkwa0B28KT7VmhUDuFtTXPnQVQkCTKxBMF529kOmELE1LVcGuRM1N5LijEoX0jDKclyD7EMWFa0sp72GHNSRMmaYylFeMB5CQKs5NLyF1vAG/1AWnDnMZAtQHmPzxGofE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=anthonyvardaro.com; spf=none smtp.mailfrom=anthonyvardaro.com; dkim=pass (2048-bit key) header.d=anthonyvardaro-com.20251104.gappssmtp.com header.i=@anthonyvardaro-com.20251104.gappssmtp.com header.b=pxNlgQO9; arc=none smtp.client-ip=209.85.216.52 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=anthonyvardaro.com Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=anthonyvardaro.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=anthonyvardaro-com.20251104.gappssmtp.com header.i=@anthonyvardaro-com.20251104.gappssmtp.com header.b="pxNlgQO9" Received: by mail-pj1-f52.google.com with SMTP id 98e67ed59e1d1-39266382df6so1182576a91.3 for ; Fri, 21 Aug 2026 13:49:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=anthonyvardaro-com.20251104.gappssmtp.com; s=20251104; t=1787345365; x=1787950165; darn=vger.kernel.org; h=content-transfer-encoding:content-type:mime-version:references :in-reply-to:message-id:date:subject:cc:to:from:from:to:cc:subject :date:message-id:reply-to:content-type; bh=kqSSIILac7u1pKPNOUJ/EuEid7Kx/XiiY4lOm0AmR9M=; b=pxNlgQO9mm++xzF4oXrefkBI65NmRj4cE0PEedeGWceXW7ZZqIwefKR8zJTqWW49pU vivmGkd3PuuoukiW21eRFTEM7xAUsAQt0Ej2guG4g3I7iUHnprHcwz5wKp1fSZ0GHW5z xGC7EXSYdCBIO2gkBV/eOcrggfcIHRgDw5dNp3rmTldysedffpxbUKAvqm72xFMBJO0o Fue3GwRV1Ag9amZ7js9v93rD8a1zIkdAPa4mhXIPCdy2YclpWWExTvsafOwo7AYPn0FF CvlNUtZXMvQhFOEweheJZFbgY7F2to6+7n8juJbTlHhkJeufngmMyA/3UZIpJBUkkoC6 wd5g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1787345365; x=1787950165; h=content-transfer-encoding:content-type:mime-version:references :in-reply-to:message-id:date:subject:cc:to:from:x-gm-gg :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=kqSSIILac7u1pKPNOUJ/EuEid7Kx/XiiY4lOm0AmR9M=; b=WxltSI+X/gUHZEZYqefjlk512Pqik4BGxn+3gbjD4UN5evZ86P18vsqrfYvlncuiy4 mD8QoKRY+/ilHS4C3ySa3NOPQwUARvgUlQAzay7Xhhn4+mU5ohqlFrziUbv9jQeAbGlx U82zyJP+gycqmu48aFsUKdH6IfAeVysmCr5teet238hrk6YoFy2APYST+h2xJdgYmw8a Fq6O9Rjpa43/m06K9QVos6IzAAB6DDoomHlm/VkEhGHOv+MD4yEI7w6oQsh3dzrPTBpS 3WKLhTU6wLygK92DPAERsGf6v2ilPa9NfKlgy8oUtL3/Mzt23Nx+faSTX+FOKZXZEYLo +xpw== X-Forwarded-Encrypted: i=1; AHgh+RqIXnV3Ig91pTM7ZYqjoMNjGoG99Ib2rVU1myv0c6OluK3wIhlrot31mKB1Hae4sU74exvVwizYtrnmYfA=@vger.kernel.org X-Gm-Message-State: AFuF++lIsP+2Ipm4xID8DornnHr36DHB1660V2koVrie2yLGSbVDMIQL JJEuzO4XHjWOnzJWTrwRtQ4DxIjhOoDKNrFGyH1aHRmw7PRBTozyFCJ6HiM649c94F/Y29TMnMk 6fSRSgJE= X-Gm-Gg: AR+sD134ocbezxfUehG7CYOYkCcEUs0kc2hNTZ/Ac8/9rrNgzr+ynzxdlfNehQedrOV Q7yws8WJo6xnOXx8fvBu1Yl8eHE+1WhChXdEGyoVsr66nVYEDMZCHt+yuwlY8uk9W8kAnk9OV8s YJv9XO+ugNG5I7MrIShDBTpZgQW+IOKmSaoiJhz+DpmJ5SXQPCQ9Xg8a8BF0N7cie+efIwcaL3p NQwtfT7yrqK49ztp7iveMIneHM2fwlMiC+gCvcjKW7Q73YPnynMVAYzPZpDCQBsP/hy1ApTmWUR 53Cr7QHDWRiqo5E4dyM/sbWJDh66wavgBCI0gLSOr7HvJ0vjaI3px5qfSqJxkcPwhc91hK64e7c VnwPp3yDiQ2+c3anH+YdGeVPQf9yrgOo/r6GSHbWIPvBTddjJYFB8HSg4hIJnY9R5Zx1I6B43dV HcrtMx5Jq4d5rTQRmiytw2dgSfKneWGlcO4YMnzECmBtXXW+gUXdHb5kP/LT1NvT0YN6lzIQU62 emn7WrhT25s87DHLbO/hA5LPpovSCgfcs9zLLs4HCRHnm8HwgeltX6WWUZdq5XnB2mQ0HJdRdyz lxPY1g1dW2pHfAeH3HjiYdQjBWlFhzClnEpNlq/2+OZk9Pj8bJw= X-Received: by 2002:a17:90b:6cb:b0:366:3517:1aa2 with SMTP id 98e67ed59e1d1-395c2f13243mr17933317a91.0.1787345364660; Fri, 21 Aug 2026 13:49:24 -0700 (PDT) Received: from coder-vardaro-vardaro-2-0.tail2dda0.ts.net (ec2-16-145-69-213.us-west-2.compute.amazonaws.com. [16.145.69.213]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-395e4b2af01sm101253a91.14.2026.08.21.13.49.23 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 21 Aug 2026 13:49:24 -0700 (PDT) From: "Anthony Vardaro (Anthropic)" To: "Darrick J. Wong" Cc: "Anthony Vardaro (Anthropic)" , Carlos Maiolino , linux-xfs@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH] xfs: revalidate cached COW fork mappings during writeback Date: Fri, 21 Aug 2026 20:48:43 +0000 Message-ID: <20260821204843.3223395-1-me@anthonyvardaro.com> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260820161123.GH6072@frogsfrogsfrogs> References: <20260820-b4-xfs-cow-wb-revalidate-v1-1-8a19080799ea@anthonyvardaro.com> <20260820161123.GH6072@frogsfrogsfrogs> 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=utf-8 Content-Transfer-Encoding: 8bit On Thu, Aug 20, 2026 at 09:11:23AM -0700, Darrick J. Wong wrote: > The buffered write path has similar data/cow fork sequence counter > revalidation code, so would it be a better idea to adapt the writeback > path to sample the sequence counter via xfs_iomap_inode_sequence in > xfs_map_blocks, and re-check that in xfs_imap_valid()? > > I weakly hinted at this a few years ago when we were adapting the > buffered write path, see [1]. > > [1] https://lore.kernel.org/linux-xfs/Y2mcOCpKiDb4nf1X@magnolia/ I think that's reasonable. It's mostly deletion since xfs_bmapi_convert_one_delalloc() already fills wpc->iomap.validity_cookie. I'd still like 1/2 to stay the small private cow_seq check so it can go to older stable trees, which don't have validity_cookie or xfs_iomap_inode_sequence(). So for v2 I'll send two patches: 1/2 for this fix, Cc stable; 2/2 samples xfs_iomap_inode_sequence() in xfs_map_blocks(), compares the cookie in xfs_imap_valid(), and removes data_seq/cow_seq, with the cost measured again. Anthony