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 4CE2225CC45; Mon, 5 May 2025 14:57:19 +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=1746457040; cv=none; b=Zp6toI5v3PGwUbsjYO1k9bNcXzMK0ORPuf19M1CF9k9mtRjl5q6qvi8kB6uXSafgASMO5VEUrjvu3CoszjTWfaZk9apErgmpvNRJ1FcWafZygSWJIz+8RgOWm3Jt0/mKD24lAnJ2tcMlLUX4hyQZ4Q1EEy+cXe4tWYIGWMDJAI8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746457040; c=relaxed/simple; bh=YXBLGFfCSiNERP2l1252Bbo0ChipWii3oYahuv6UgPE=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=rCkzAq9GW4baaSABq5sW7uTi/N7Yxv44UCY8UVLSo7atTlsiSjKNTdYHYeAhDKIlGMyXVHc21tyRdAHuyrqgHOLHCu5gaIQ1ktbAie1hgEGU1SeSFvtWejVlRhlwytz1d6BMpEQL+e5uVh0JvpEeOhtOKzw17vU5/uyqbIJBrLs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=JtFi3GOY; 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="JtFi3GOY" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A901EC4CEF5; Mon, 5 May 2025 14:57:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1746457039; bh=YXBLGFfCSiNERP2l1252Bbo0ChipWii3oYahuv6UgPE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=JtFi3GOYrH9nID2fxqmQJ+ntSD0GsUSivANnY/Zb6ZyHy+PYAQdMO3iSo/ltbEfzb qGWCVLZK/6y2TAfZmJYHuBd3/ZusBqvMXPJIqOrJVjUQwkPhaoORldgdhuXap7B4bV 3ORdDdVcC2dKLfcouK+oH2uQhUD9/T3vrZOZBsiu2+wDUkT0HtRxfC/vSeGGyYekD+ YStS4KlSDbxpa2BANmOQFghQj2M5jyaRBbCv+LEF35Wz0M3+GLrYzQfzRY/giA4r2M nwRfDZ9qEJPk5qSc6ojndkZb8eJMEnwemQemXw5iw1UkHd3M277b9Q/T4emOKvjXiN +rbd8qxR5hMbA== Date: Mon, 5 May 2025 07:57:19 -0700 From: "Darrick J. Wong" To: Christoph Hellwig Cc: Catherine Hoang , linux-xfs@vger.kernel.org, fstests@vger.kernel.org Subject: Re: [PATCH v5] generic: add a test for atomic writes Message-ID: <20250505145719.GY25675@frogsfrogsfrogs> References: <20250410042317.82487-1-catherine.hoang@oracle.com> <20250502193942.GP25675@frogsfrogsfrogs> Precedence: bulk X-Mailing-List: linux-xfs@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: On Sun, May 04, 2025 at 10:37:07PM -0700, Christoph Hellwig wrote: > On Fri, May 02, 2025 at 12:39:42PM -0700, Darrick J. Wong wrote: > > Me neither. We can't write 512b blocks to the rt device obviously, but > > I think the whole point of the separate "sector" size is that's the > > maximum size that the fs knows it can write to the device without > > tearing. > > The sector size is really the minimum addressable unit. > > > Maybe there's a way out of this: the only metadata on the realtime > > volume is the rt superblock, whose size is a full fsblock. Perhaps we > > could set/validate the block size of the rt dev with the fsblock size > > instead? > > We still allow subsector dio to the rt device, so this would be a bit > of a sketchy change. I don't understand the 'subsector' in this sentence -- we allow sub-fsblock dio, but not sub-LBA dio, right? So the only thing we need to validate for the rt device is that fsblock >= lbasize to avoid confusing the pagecache when it does IO, as well as user programs that aren't expecting such things. --D