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 B8FD82EDD53; Fri, 14 Nov 2025 19:47:15 +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=1763149636; cv=none; b=O1f+P8PelD9nTkshXf173r7zOG4VxcyFonQ4q05XAD8DMhPqsnrBF7cHdZszS/oSG3ovPGUpv1In9bIgf7usPBFJitvlGH4q71cIyFj+mZDLG6slAHLihwsGfjsKOR0XWWryjmQoaEfMuttSXNUGaNDghn2df75Vk2l2MaUuPxw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763149636; c=relaxed/simple; bh=REeSO5rMp1YGjY627e4cE9lzZEy2V6tti6RpwKKRYO4=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=MTNjLUi+u/qSHMTTAMfFD8K4Wx7BKSlEhQosqFfgOGeJF8CJLFWAqrVdI7UU25zOExN6k2r6dNfMtOVK5GsbLuKY0SanBFRKxzHAenpZjYqwutETkMcGRkANmeBeHgHuWVxcPKZ5tyBdeWr5qPdjyAlkBjxIGEuGwg2mZDyI96g= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=DxygaeVo; 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="DxygaeVo" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C1033C116B1; Fri, 14 Nov 2025 19:47:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1763149635; bh=REeSO5rMp1YGjY627e4cE9lzZEy2V6tti6RpwKKRYO4=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=DxygaeVo++Am9yVdIn2xmS6RdOu/inN1IV3jHs/i65Il9sH4kXFCXZQRH5PqD9kr7 EEjZxd3IRMWSOQchWHEfgw+idatwGYPzx/gD3u5YjLB1Pt0fG2Pogz1QmjK0o00JkM DrMxy1bSGkJycCGUE+c/nOa8kTJi6YXXNZF7GP2h2ijlzMvK0RwGo6u73krrsINHQT pjI7iap4NoyYLSCxOqlCq/TOw6v5+9tGwYMh8s5ujo+Q+Fl/45AJ5iWazDHDFLKddh 7v9ff2dr2Gf3S9MQ8/+MOVQsoprAYDXpgjpmSCO+YO8o4MXPlDQeYOa9TdZi2Wi+l4 X1LsouQTUgnng== Message-ID: Subject: Re: re-enable IOCB_NOWAIT writes to files From: Jeff Layton To: Christoph Hellwig Cc: Christian Brauner , Al Viro , David Sterba , Jan Kara , Mike Marshall , Martin Brandenburg , Carlos Maiolino , Stefan Roesch , linux-kernel@vger.kernel.org, linux-btrfs@vger.kernel.org, gfs2@lists.linux.dev, io-uring@vger.kernel.org, devel@lists.orangefs.org, linux-unionfs@vger.kernel.org, linux-mtd@lists.infradead.org, linux-xfs@vger.kernel.org, linux-nfs@vger.kernel.org Date: Fri, 14 Nov 2025 14:47:12 -0500 In-Reply-To: <20251114152840.GD30351@lst.de> References: <20251114062642.1524837-1-hch@lst.de> <20251114152840.GD30351@lst.de> Autocrypt: addr=jlayton@kernel.org; prefer-encrypt=mutual; keydata=mQINBE6V0TwBEADXhJg7s8wFDwBMEvn0qyhAnzFLTOCHooMZyx7XO7dAiIhDSi7G1NPxw 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Evolution 3.58.1 (3.58.1-1.fc43) Precedence: bulk X-Mailing-List: linux-unionfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 On Fri, 2025-11-14 at 16:28 +0100, Christoph Hellwig wrote: > On Fri, Nov 14, 2025 at 09:04:58AM -0500, Jeff Layton wrote: > > This all looks pretty reasonable to me. There are a few changelog and > > subject line typos, but the code changes look fine. You can add: >=20 > Please tell me about them so I can fix them.=20 >=20 > > As far as nfsd's usage of FMODE_NOCMTIME, it looks OK to me. That's > > implemented today by the check in file_modified_flags(), which is > > generic and should work across filesystems. >=20 > Nothing requires file_update_time / file_modified_flags are helpers > that a file system may or may not call. I've not done an audit > if everyone actually uses them. FWIW, I turned claude loose on this, and it produced: -------------------------------8<---------------------------------- Findings: =20 = =20 1. coda_file_write_iter (fs/coda/file.c:66-94) =20 = = =20 Location: fs/coda/file.c:86Issue: Manually updates ctime in write_iter operation =20 inode_set_mtime_to_ts(coda_inode, inode_set_ctime_current(coda_inode)); Context: This is a stacking filesystem that delegates writes to a container file via vfs_iter_write(), then manually copies attributes back. However, it bypasses file_update_time() or file_modified(), =20 which means it doesn't handle: =20 - Read-only filesystem checks =20 - Immutable inode checks =20 - S_NOCMTIME flag =20 - i_version updates =20 - Proper dirty marking =20 = =20 2. efivarfs_file_write (fs/efivarfs/file.c:15-77) =20 Location: fs/efivarfs/file.c:66Issue: Manually updates ctime in write operation =20 inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode)); Context: Uses the legacy .write operation (not .write_iter), but still a write path that should use proper timestamp helpers. 3. ocfs2_write_end_nolock (fs/ocfs2/aops.c:1926-2050) Location: fs/ocfs2/aops.c:2024-2026Issue: Manually updates ctime in write_end callback inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode)); di->i_mtime =3D di->i_ctime =3D cpu_to_le64(inode_get_mtime_sec(inode)); di->i_mtime_nsec =3D di->i_ctime_nsec =3D cpu_to_le32(inode_get_mtime_nsec(inode)); Context: This is called from OCFS2's write path. While ocfs2_file_write_iter calls __generic_file_write_iter, the write_end callback manually manages timestamps. This is used both by regular writes and page_mkwrite via __ocfs2_page_mkwrite. 4. ubifs_vm_page_mkwrite (fs/ubifs/file.c:1493-1580) Location: fs/ubifs/file.c:1570Issue: Manually updates ctime in page_mkwrite operation inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode)); Context: UBIFS implements its own timestamp update logic with mctime_update_needed() and manual budgeting for space, bypassing file_update_time(). -------------------------------8<---------------------------------- Only ocfs2 is exportable, so I think we want to convert that one. The others I'm not sure of yet. --=20 Jeff Layton