From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 D31B41F94A; Mon, 14 Jul 2025 16:04:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752509041; cv=none; b=S/Hgn+XBeOmdUT6hlHlXuhInI/hYGYG9G/rTA5cfjjhDv1R3EFl6LRLz+cLEoaiBgnVZXXPpYSX/d4AFUd1rbSZf1xPvUQPbQFSVfs9fA19uavZ9nVkYxjeF6zOqJc2/NpKhryiGcacsqZ+NJKoACHSDF/9Q8I5jp3g+qGTTcvk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752509041; c=relaxed/simple; bh=AHdmcwDk69P0bsuDXUAUbKZgYi6IjvT1mhl/qsg2pFw=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=cqHtHnqDefufDQS3NMCLuynGtjGVn7PorfXSL+DqiI1F1IG6DnT3eDU9FY8zgkAHMZqRR4iEcDmow53dfKhn6Xm2eIh+F8eSAE0QxtlFN65/T/qNkYAQ8xJI42MJFIqcXQuK3Q+A093jMU7vwHQTcJK8r702d923HlWZ1giXvuI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=G/0Zk/Dl; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="G/0Zk/Dl" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 52AA6C4CEF0; Mon, 14 Jul 2025 16:04:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1752509041; bh=AHdmcwDk69P0bsuDXUAUbKZgYi6IjvT1mhl/qsg2pFw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=G/0Zk/DlO4/RGceMRxhdRCcVamfcty52cZZds5h1ZtTGD1N/s0qVnZzVVIKATF5ZN fcnomUp7Nkq/zyNgKumD3M1G+Ba7iz7qM4ukSEeQB75MYfTZoKNX0vcb2QdXttFS2L yEtEAIY1YMM8L4JsLctZ7G8gMSB5Wy1ElbNlTRaLV1zsdR5pwSWVatXFVbLKiEffB7 2avLGgmbKkY6WRDjGX5P50O45SlosYxfPpw8BB3BI3NPNRmirTrqANymHNgHm7sm7F J44cYxkml4vMF/IHRcuS6CF2UwQF5rjPTCMuiXqUU9w7o5umLg8GnMKhjtrTJ9GzeW RknHjdOMVGf4Q== Date: Mon, 14 Jul 2025 09:04:00 -0700 From: "Darrick J. Wong" To: Christoph Hellwig Cc: Theodore Ts'o , John Garry , linux-fsdevel@vger.kernel.org, linux-xfs@vger.kernel.org, linux-block@vger.kernel.org, linux-nvme@lists.infradead.org Subject: Re: Do we need an opt-in for file systems use of hw atomic writes? Message-ID: <20250714160400.GK2672049@frogsfrogsfrogs> References: <20250714131713.GA8742@lst.de> <20250714132407.GC41071@mit.edu> <20250714133014.GA10090@lst.de> Precedence: bulk X-Mailing-List: linux-block@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250714133014.GA10090@lst.de> On Mon, Jul 14, 2025 at 03:30:14PM +0200, Christoph Hellwig wrote: > On Mon, Jul 14, 2025 at 09:24:07AM -0400, Theodore Ts'o wrote: > > > Is is just me, or would it be a good idea to require an explicit > > > opt-in to user hardware atomics? > > > > How common do we think broken atomics implementations; is this > > something that we could solve using a blacklist of broken devices? > > I don't know. But cheap consumer SSDs can basically exhibit any > brokenness you can imagine. And claiming to support atomics basically > just means filling out a single field in identify with a non-zero > value. So my hopes of only seeing it in a few devices is low, > moreover we will only notice it was broken when people lost data. Do you want to handle it the same way as we do discard-zeroes-data and have a quirks list of devices we trust? Though I can hardly talk, knowing the severe limitations of allowlists vs. product managers trying to win benchmarks with custom firmware. :( --D