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 68E2228C5A3; Mon, 3 Nov 2025 18:26:13 +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=1762194373; cv=none; b=aYI1S3ePWDxM/uCZcKC24SZIKX3xpjp2lGtdpQ9eFux4EPG1Tsav76lj/DT5WIiG9UEnmDRUc6UI0XxURxictKh/R1HdfjNx6aDrsgTQctoosp0NUw0uhAWrLTl83VM3UjGSKv8UW4GIJSp0nSjQFx2meZBAzbj8QWjPVgeO07I= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762194373; c=relaxed/simple; bh=sRSZoD69PFGuks85RFT1srPpiVwKNmQT4VB9C/IpXzY=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=STCdiAA4GxlhsCa3Wzv6wibP+f22ZnXJp8HPhulAaP+GuQ2CkZRHKbmpW8NX1NYKN0jfeNW/cISmMCj9X6nSHqsW29lFPQqqgLgvLmFaoeMjUTli6bD2kcaymKzgWGz6SXZJka6ojP3idfYNs8WfY23wfsyiK5OxhygIc7zrCbg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=G2ZihU4a; 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="G2ZihU4a" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5E46FC4CEE7; Mon, 3 Nov 2025 18:26:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1762194372; bh=sRSZoD69PFGuks85RFT1srPpiVwKNmQT4VB9C/IpXzY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=G2ZihU4a88IT22zwpS3yuXfwvIiDBx6cfn1WYWQSDZ0xh3tIib40apeN4lEUDlsX3 ToplXbMzIQHKdhYoYnpUJZY/X28X0853r/1gcExjQpT6+M03Qr/r8fq66Ubpt005QI lEjPlDHCiWHCcaiKGVayPuOCEAb9Iowqqse2T5SDi99SFOl/49Kw3MRC5npoWHbNF1 9Fg7pNPHEoJt1z8Jv/UZY4TDEv7S/ZdciooTlybikXQR+dzkZgLQv5AE6AjGZSnjBX MhrhZq1pmf460cWqCHWDF15Z0zLANqmVOwVSO3MDzXgnt60931PdYq3Kup5Ke3jGVg 8O/C1FWGJ7oNw== Date: Mon, 3 Nov 2025 11:26:10 -0700 From: Keith Busch To: Eric Biggers Cc: Christoph Hellwig , Carlos Llamas , Keith Busch , linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-xfs@vger.kernel.org, linux-ext4@vger.kernel.org, axboe@kernel.dk, Hannes Reinecke , "Martin K. Petersen" Subject: Re: [PATCHv4 5/8] iomap: simplify direct io validity check Message-ID: References: <20250827141258.63501-6-kbusch@meta.com> <20251028225648.GA1639650@google.com> <20251028230350.GB1639650@google.com> <20251029070618.GA29697@lst.de> <20251030174015.GC1624@sol> <20251031091820.GA9508@lst.de> <20251103181031.GI1735@sol> 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: <20251103181031.GI1735@sol> On Mon, Nov 03, 2025 at 10:10:31AM -0800, Eric Biggers wrote: > On Fri, Oct 31, 2025 at 10:18:20AM +0100, Christoph Hellwig wrote: > > > > xfstests just started exercising this and we're getting lots of interesting > > reports (for the non-fscrypt case). > > Great to hear that it's starting to be tested. But it's concerning that > it's just happening now, 3 years after the patches went in, and is also > still finding lots of bugs. It's hard for me to understand how it was > ready, or even useful, in the first place. I've been using these memory alignment capabilities in production for quite some time without issue on real hardware, and it's proven very useful at reducing memory and cpu utilization because that's really how the data alignment comes into the services responisble for running the disk io, and the alignment is outside the service's control. Christoph is testing different use cases with check summing and finding much of the infrastructure wasn't ready to accept the more arbitrary memory offsets and lengths. Finding it now is more of an indication that those two use cases haven't overlapped.