From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 6F351606A333 for ; Wed, 11 Nov 2026 14:56:55 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 981A16B05B7; Wed, 11 Nov 2026 09:56:54 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 9593F6B05B8; Wed, 11 Nov 2026 09:56:54 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 896E06B05B9; Wed, 11 Nov 2026 09:56:54 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id 664016B05B7 for ; Wed, 11 Nov 2026 09:56:54 -0500 (EST) Received: from smtpin13.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 6CF61A7BFE for ; Wed, 11 Nov 2026 14:56:52 +0000 (UTC) X-FDA: 85423140264.13.2CAA598 Received: from verein.lst.de (verein.lst.de [213.95.11.211]) by imf30.hostedemail.com (Postfix) with ESMTP id B318C8000B for ; Wed, 11 Nov 2026 14:56:50 +0000 (UTC) Authentication-Results: imf30.hostedemail.com; dkim=none; dmarc=pass (policy=none) header.from=lst.de; spf=pass (imf30.hostedemail.com: domain of hch@lst.de designates 213.95.11.211 as permitted sender) smtp.mailfrom=hch@lst.de ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1794409010; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=uTScRtTvc50Ly2VnPZ+IRL7zVmHRGtRnjIEMUslXOU4=; b=BAunDrQVzjrFX7ruZzO1JmTaQf2FAU5IzY1qia2dSwO36sAYPSZT8tyXRoWRN6LxWmTMH2 kpUQ6UWAl5o/q6hjTY463Em5Xq+EghrM8jm824nJ+gL0YyXup5otld9bpgP7QkMVFNgzX1 yU4f6CEN6Cjr09jTSD5hDMGugOijVd4= ARC-Authentication-Results: i=1; imf30.hostedemail.com; dkim=none; dmarc=pass (policy=none) header.from=lst.de; spf=pass (imf30.hostedemail.com: domain of hch@lst.de designates 213.95.11.211 as permitted sender) smtp.mailfrom=hch@lst.de ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1794409010; b=5nDCNB0wi98XCDCdTIuqiC05BJNr8qdnNOUbc2cgEg4eSfyIGNfSa0oRVx/9Ierh5Doy64 BQrfjWFYBg9WgqZOnFTuaH2IEcAxEEt3XX9KxHeoplx98iJV6KfuWGRev9vijEllgkkZFp ybWxeNpNkloFr6c9sQ9Mt99shaWlA1I= Received: by verein.lst.de (Postfix, from userid 2407) id BF2AF68D09; Wed, 11 Nov 2026 15:56:47 +0100 (CET) Date: Wed, 11 Nov 2026 15:56:47 +0100 From: Christoph Hellwig To: Christian Brauner Cc: linux-fsdevel@vger.kernel.org, Jann Horn , Chris Mason , Josef Bacik , Christoph Hellwig , linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org, Alexander Viro , Jan Kara , linux-scsi@vger.kernel.org, target-devel@vger.kernel.org, driver-core@lists.linux.dev, linux-mm@kvack.org, bpf@vger.kernel.org, linux-security-module@vger.kernel.org, selinux@vger.kernel.org, apparmor@lists.ubuntu.com, linux-nfs@vger.kernel.org, netdev@vger.kernel.org, fuse-devel@lists.linux.dev, linux-efi@vger.kernel.org, xen-devel@lists.xenproject.org, ocfs2-devel@lists.linux.dev, linux-s390@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-usb@vger.kernel.org, Amir Goldstein , linux-erofs@lists.ozlabs.org, linux-kselftest@vger.kernel.org Subject: Re: [PATCH RFC 03/41] target: fileio: check that the backing file supports ->{read,write}_iter Message-ID: <20261111145647.GC9996@lst.de> References: <20261110-work-loop-pseudo-v1-0-4c998976c6c7@kernel.org> <20261110-work-loop-pseudo-v1-3-4c998976c6c7@kernel.org> X-Archived-By: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20261110-work-loop-pseudo-v1-3-4c998976c6c7@kernel.org> User-Agent: Mutt/1.5.17 (2007-11-01) X-Rspam-User: X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: B318C8000B X-Spam-Status: No, score=-10.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, SPF_HELO_PASS,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=4.0.1 X-Stat-Signature: nokggyxyotyj6qxrmenewzxab9fb466w X-HE-Tag: 1794409010-373097 X-HE-Meta: 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 CW7osW5v nCHbM4/JQk579CRmZwUZ+l++gZDpsgT1NdLOQDuprgB/f44USkzFP6swbUavAChDJs3nrnay/tTS4POqLtECu44zlG1mXsc6z+dpi3yY+wdqVxqt7btU/hRXWtCMBtMWF8tFQqB6QM8T/dss= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 On Tue, Nov 10, 2026 at 10:14:19AM +0100, Christian Brauner wrote: > With fd_async_io=1 the fileio backend calls ->read_iter() and > ->write_iter() of the backing file directly. The synchronous path goes > through vfs_iter_read() and vfs_iter_write() which check for them but > the aio path doesn't. So a backing file without them calls a NULL > pointer on its first I/O. > > Refuse such files when configuring the device. On the synchronous path > every read or write that needed the missing method failed with EINVAL > anyway. Looks good: Reviewed-by: Christoph Hellwig