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 5375320298D; Thu, 22 Jan 2026 18:04:26 +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=1769105067; cv=none; b=M86Woi1zwOpMHN9ZgbpuxYDGXJSVvcL9kATlq9iWrKirIAib5VflXrIJrw4er+XoqiF/WGttYV/ePbAHcAaTo1FAyn/GdyhmDCzoQuC3VkNMOFeCd4siaHJ3k7SUjsTvSrrR0Ab9KD7ZoIntimDo6/vCCZXzY69untz3K0TDW98= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769105067; c=relaxed/simple; bh=NRcfnBfc/uf0Kgun1SB8oAWnZ++/lrKR1XlM4gal20k=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=KhaqKhDjSZqSAE1N+x9KnyyqY/OHZMkt+NMPaDRXeglaxAt6hor/7VxrvIYIVEAWTwdyciuzFrkFmD79WoJEHFKJ7rtPhCSQxwZo346a675PoqzhQymbbxZiZI8n/6VkAQ9S+ormo5+fmh2M6QvvHIYP8NaV7Iq7+e35QQoiq/4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=QODMgOqS; 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="QODMgOqS" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9EB5EC116C6; Thu, 22 Jan 2026 18:04:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1769105064; bh=NRcfnBfc/uf0Kgun1SB8oAWnZ++/lrKR1XlM4gal20k=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=QODMgOqS1CoZDHQRoxAeZjfHZa3GlQYfTY58ZEkbbhrCLMNmT9uxNd6/sUzXluz0e PDln5IwNp7FCRmz5DQ+hIUhBD1fWzHcvvBsc55i+Iw5ebXOH3bIa3M4aw4VHEDQnfQ +NrPQ0ns+gHf9SDaf2GBJVEaldp7mj84kPGCBjYC1NzwbUJe2HmAznz+kr7hRVFm2x 9J2pe0g9wvkOoLkaYtJTzIrSnR2xPzOtJnjK+GLXPMJuHV1VpMLF9Wl+6nnysCpDLZ LwkFVClSK5ZIZy3SlrXy1GJgEoKQ7UXVb0mgE7mBsY8QflczEBsCrno6zevpOLbEhD 7Y3d7TOkTpUSA== Date: Thu, 22 Jan 2026 10:04:24 -0800 From: "Darrick J. Wong" To: Christoph Hellwig Cc: Jens Axboe , Christian Brauner , Carlos Maiolino , "Martin K. Petersen" , Anuj Gupta , Kanchan Joshi , linux-block@vger.kernel.org, nvdimm@lists.linux.dev, linux-fsdevel@vger.kernel.org, linux-xfs@vger.kernel.org Subject: Re: [PATCH 11/15] iomap: allow file systems to hook into buffered read bio submission Message-ID: <20260122180424.GC5945@frogsfrogsfrogs> References: <20260121064339.206019-1-hch@lst.de> <20260121064339.206019-12-hch@lst.de> <20260122004933.GO5945@frogsfrogsfrogs> <20260122060114.GB24006@lst.de> Precedence: bulk X-Mailing-List: linux-fsdevel@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: <20260122060114.GB24006@lst.de> On Thu, Jan 22, 2026 at 07:01:14AM +0100, Christoph Hellwig wrote: > On Wed, Jan 21, 2026 at 04:49:33PM -0800, Darrick J. Wong wrote: > > > verifying data checksums. Allow file systems to hook into submission > > > of the bio to allow for this processing by replacing the direct > > > submit_bio call in iomap_read_alloc_bio with a call into ->submit_read > > > and exporting iomap_read_alloc_bio. Also add a new field to > > > struct iomap_read_folio_ctx to track the file logic offset of the current > > > read context. > > > > Basically you're enabling filesystems to know what's the offset of a > > read bio that iomap is about to start? > > Yes. > > > I guess that enables btrfs to > > stash that info somewhere so that when the bio completes, it can go look > > up the checksum or something, and compare? > > Yes, where something in this series is the ioend that the bio is embedded > into. > > > Or for PI the filesystem can do the PI validation itself and if that > > fails, decide if it's going to do something evil like ask another > > replica to try reading the information? > > Yeah. If your file system can do it. Nothing in this series does > that, though. and at this point we're never going to circle back to that project either. :/ In the meantime I think I've understood this patch well enough to say Reviewed-by: "Darrick J. Wong" --D