From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 5D75A563299; Wed, 9 Sep 2026 13:45:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788961502; cv=none; b=pU6QRaL26MxVpgIY/+xxllrPAHsTlrF3FadWgTOnW2Bypr86lp5vyA8JeRUxboyG0EdRLmfXVRdO1uLDUOP5jSnEdat2Lz+6+lIOhSouBbKvdBsyIS9gr5Xk3GPs520ZxzSCogxSDxn0cVwl36XZ1CWmzvjp3WBwxihKAvD7wTw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788961502; c=relaxed/simple; bh=hyvyFx3Hrp8AftpAe7Lv1fh0M0Fz8ztoCuKn9jiiQXM=; h=MIME-Version:Date:From:To:Cc:Message-Id:In-Reply-To:References: Subject:Content-Type; b=Fh1ABlW460nc7RBAsWXvKR/tMuqTMH59MBYDFPmwgL+qjWBmKE56C76+q+O8vlBBGQU+ETiPwvjPG1KtJqgjFWXnwX+Qz9689DNtwZDTu/9+AqfQshrkV608uIOBj690ztkP6xomHZXYKon3k+5Pky/BUmlUT2qTSdeYwzWvMDQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=k8yedqaJ; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="k8yedqaJ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 829F41F00A3D; Wed, 9 Sep 2026 13:45:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788961501; bh=hyvyFx3Hrp8AftpAe7Lv1fh0M0Fz8ztoCuKn9jiiQXM=; h=Date:From:To:Cc:In-Reply-To:References:Subject; b=k8yedqaJgOTFkjLsyKu1ZDe87lRhmSqEDREp+KgeI8srQL310iFWMVnwntR26otOH eHerCGJ3TBKZrIBFo+PtmgPeDZYPCNbxhktk+G0m9CGpSbk3o7U07D3Q07PyF/W71V psd4jFcXVyY8al92TTahW66EQSIsJtZc6Eetq+XtDN9xW5CCYSnsBaofeQp6G5FhnY oXbpF/NzMhuJn89p9yg9lFnemouI97forL68yBKaWYTIU0pQ/BD41LmTQHCLkgytnR GS3uBF1wzV4xCrhGkkjFnn0nDzYlk0kiLOOvLvcLNit0FKqjS0ReIqJKhYlaHlu6em Bo1z2bcdl5KbQ== Received: from phl-compute-10.internal (phl-compute-10.internal [10.202.2.50]) by mailfauth.phl.internal (Postfix) with ESMTP id 9EC78F40066; Wed, 9 Sep 2026 09:44:59 -0400 (EDT) Received: from phl-imap-15 ([10.202.2.104]) by phl-compute-10.internal (MEProxy); Wed, 09 Sep 2026 09:44:59 -0400 X-ME-Sender: X-ME-Proxy-Cause: dmFkZTG4WUQZMwjYCLD9UlI1qeoOgcX4SggFe6FfyVpgRNu0o1E1aksAGydR67sMY+0OGa RTqopGe06ybSCoNb42xWFYTDl844DaicJ69GlNKqRl7UDGv9EqOxPRoqbL2cBSwbhd2842 LNr+QCzUDKiltbMEt0cdc53YPoLakn+/GOrhbMi0lHTD2Y2rohbkUSvM/Y699QnxO9kEf5 /LQJhWfFwu3fup8DC0wto9X8B8tu3KG/F5tJ027uzrefvdorq/UL+gq/CijU+rrwojygbx g7V6cn/foyjyuZqpjPYnl5XVd8STcA6Q9799FYV15HPJHONG+jG3f4pzMlqohMRsUGGeU6 05NjnjL+fcQF6gLHuAeSejclel8grItfxJhogEe1lRwcOguQYr1S/Y/oTibUnXn+Igfotq ew0M3USENR0IL9usvarajnJwDHyUHKgq5zH4+ceuJMdFS0pM55OWlyQk5BBzxDRvNtKi1m WtQAXL6ZmJb4Wp9vTVbUTznWZ4Z7DmRcGMGhKbJiipUaAFHsX0nDXJWc6IpKUhoO3AdQG+ ecWrls4bPeB/WIiAYDnOxCaecuyg2ukxZDzUILlsFIOmdm4IpVl0Z1O87jlfW1f0GqEBR7 zfhKBWI7/SMUpFvusVfO5Gm2Q+LAhZzFPDNLYNvRzHKAuIFvtnFJzGQ1ZzWA X-ME-Proxy: Feedback-ID: ifa6e4810:Fastmail Received: by mailuser.phl.internal (Postfix, from userid 501) id 792FD7811F4; Wed, 9 Sep 2026 09:44:59 -0400 (EDT) X-Mailer: MessagingEngine.com Webmail Interface Precedence: bulk X-Mailing-List: linux-block@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-ThreadId: AvkNhIlgtVI3 Date: Wed, 09 Sep 2026 09:44:37 -0400 From: "Chuck Lever" To: "David Flynn" Cc: "Mike Snitzer" , linux-nfs@vger.kernel.org, "linux-block@vger.kernel.org" , dm-devel@lists.linux.dev, "Jens Axboe" , "Jeff Layton" Message-Id: <701e1251-bd73-49a9-b8c9-8e299b959df6@app.fastmail.com> In-Reply-To: References: <20260908163232.30774-1-snitzer@kernel.org> <20260908163448.30841-1-snitzer@kernel.org> <20260908163448.30841-5-snitzer@kernel.org> <995a853c-2c54-4bd0-9708-f6e0c1be7fd5@slotpi15m67> Subject: Re: [PATCH 4/4] nfsd: fall back to buffered I/O when a direct write gets -EINVAL Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable On Tue, Sep 8, 2026, at 11:57 PM, David Flynn wrote: > (Sorry in advance if I=E2=80=99m posting this wrong in some way - litt= le new to=20 > posting here=E2=80=A6) > > Totally agree that NFSD must not interpret generic -EINVAL as an=20 > alignment rejection... But, a boundary check would also excludes=20 > geometries that capable storage stacks could write directly. We want=20 > the actual filesystem/block decision to distinguish unsupported=20 > geometry from a real error, while retaining every working zero-copy=20 > case. Fair enough, but that's a filesystem-community question, outside of NFSD's domain. If they can agree to an API contract that NFSD can use, then I don't have a quibble. To make your argument, of course, you will need to provide a real-world use case with an existing in-tree filesystem or device that can demonstrate what you need. In the meantime, I'd like to see the narrow issue that Mike reported addressed in the current code. Fixing the current gate is not fraught with these deeper architectural issues, and the fix should be backported to LTS kernels. --=20 Chuck Lever (Come to NFS bake-a-thon! https://nfsv4bat.org)