From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 552F6C83F12 for ; Mon, 28 Aug 2023 13:56:44 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 647D48E0019; Mon, 28 Aug 2023 09:56:43 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 5F7BB8E000E; Mon, 28 Aug 2023 09:56:43 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 4C06F8E0019; Mon, 28 Aug 2023 09:56:43 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id 367B38E000E for ; Mon, 28 Aug 2023 09:56:43 -0400 (EDT) Received: from smtpin10.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id EB6CBA028A for ; Mon, 28 Aug 2023 13:56:42 +0000 (UTC) X-FDA: 81173663844.10.C68804F Received: from zeniv.linux.org.uk (zeniv.linux.org.uk [62.89.141.173]) by imf07.hostedemail.com (Postfix) with ESMTP id E4B7F4001E for ; Mon, 28 Aug 2023 13:56:40 +0000 (UTC) Authentication-Results: imf07.hostedemail.com; dkim=pass header.d=linux.org.uk header.s=zeniv-20220401 header.b=AIKhRmdL; spf=none (imf07.hostedemail.com: domain of viro@ftp.linux.org.uk has no SPF policy when checking 62.89.141.173) smtp.mailfrom=viro@ftp.linux.org.uk; dmarc=pass (policy=none) header.from=zeniv.linux.org.uk ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1693231001; h=from:from:sender: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:dkim-signature; bh=PJ90BdA+8s3qX5y6y0ylNyYbaZuzc0FQ7tGvCVtNYPo=; b=1A5BTpmRTN10GfF6UyHzE28SosQxhEHMmSlqA6CtV42u0n3J2fhsBTkU4veXstsL4eVfGC urpjFpFgi0MW0+KEVuwipfNolYZzem3ZKeJwBDZUU2vrXWaiDaXteLdg3SSbHZvXmZamyr DoRifTNoV5m9Sk7cg/e6joq6PvLliao= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1693231001; a=rsa-sha256; cv=none; b=1/02AhfWPgHnGfbu/oEBCaEO+MNZWQ/nwycndc0GTZtHJ8vmYMwSIcp3qpHeeoxkBdWFlD GswMYi/OMHb5pZnPeImIxO3fhB7fqU+q+ZlAPebkbpPVDEbyoeBQdgYtFxXT25RpSao330 EQ5jyBnVAyvFQFgWOgcD3iY8aMSu/98= ARC-Authentication-Results: i=1; imf07.hostedemail.com; dkim=pass header.d=linux.org.uk header.s=zeniv-20220401 header.b=AIKhRmdL; spf=none (imf07.hostedemail.com: domain of viro@ftp.linux.org.uk has no SPF policy when checking 62.89.141.173) smtp.mailfrom=viro@ftp.linux.org.uk; dmarc=pass (policy=none) header.from=zeniv.linux.org.uk DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=linux.org.uk; s=zeniv-20220401; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=PJ90BdA+8s3qX5y6y0ylNyYbaZuzc0FQ7tGvCVtNYPo=; b=AIKhRmdLChvBh1g3+s6EW46CKf MEbR4fH1pD3IzHz8haDpscNiqgIT1MwygtaGsg0/mJ22nTUE6hhMTmMaXMPK2UFki637fwtT5IR5e NpCkU9lVELANCdo3c4h02AUyKpTFJGcO2Yf8AdjY5H7ThMDg0k1adrBbq/dNvtWwWnE3JjBJPdXc+ ZymQQTBtlnb8KZghvPVKQ32cCYcqGFspsFg4ARKclGMJ6roXU/fBsxC40PaksuQ+i2Lrun7tK4Cxw NodllbY3kB+LQ2ImYXlQY7RelX2cS+RJORhfHJhRq6XyXuEQGqfPM8/oHIO2kXnO0q6TWo/qN/Di3 04k9P7lQ==; Received: from viro by zeniv.linux.org.uk with local (Exim 4.96 #2 (Red Hat Linux)) id 1qacj1-001ZTg-1Q; Mon, 28 Aug 2023 13:56:15 +0000 Date: Mon, 28 Aug 2023 14:56:15 +0100 From: Al Viro To: Christoph Hellwig Cc: Matthew Wilcox , Jens Axboe , Xiubo Li , Ilya Dryomov , Christian Brauner , Theodore Ts'o , Jaegeuk Kim , Chao Yu , Miklos Szeredi , Andreas Gruenbacher , "Darrick J. Wong" , Trond Myklebust , Anna Schumaker , Damien Le Moal , Andrew Morton , linux-block@vger.kernel.org, ceph-devel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, cluster-devel@redhat.com, linux-xfs@vger.kernel.org, linux-nfs@vger.kernel.org, linux-mm@kvack.org, Hannes Reinecke Subject: Re: [PATCH 03/12] filemap: update ki_pos in generic_perform_write Message-ID: <20230828135615.GW3390869@ZenIV> References: <20230601145904.1385409-1-hch@lst.de> <20230601145904.1385409-4-hch@lst.de> <20230827194122.GA325446@ZenIV> <20230827214518.GU3390869@ZenIV> <20230828123259.GB11084@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230828123259.GB11084@lst.de> X-Stat-Signature: fygxjaiz74mfbc3r3gatnfpcb6oxqqh5 X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: E4B7F4001E X-Rspam-User: X-HE-Tag: 1693231000-341617 X-HE-Meta: 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 X+M1iriy CWj+Iy4I0ejlyYWByIa8rJHmfrCXKJFqGfXmcb7uAk5+nP7W75B7QONI/94JwLVPqN0rJgJpTbeZnFsSdAo+tA6qWyqQY1MtERbjeeFl3BIV1V6ztFcYk5mNIvqlUZDriFJf601/RU/Rtk9jzoYHzLEDCoQYiZbph5xP9NxKUusnRdrytlj0xs3OdTBizkYJTC3UoYoEDDH6e8RMgW4PmLdhrsJMok67fEys4tKtbcly6hRft9ZladwafFnJOtX1Y2NhYXBXyU4bnT2AtD6C90jZrabKHnUrSAGxor8Piw5qyPgl6Kl6mz6N/yS90COY5Z1+ay134PctqjvI84Add38QxghjXDG72Mn+sgeirj33jvj7qYYcsWKfZ7blgSVgX5OJcVrJY1527G12GKFrq/Ssy8XP+n3EG7uc+7WA3MTW858QlAaPTRDwLQZ9R9RgC5MOG4+Vu4DyjIV6eS7ESDe1Y4v2KV2NHlzqxSgdwki4LyQQ= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Mon, Aug 28, 2023 at 02:32:59PM +0200, Christoph Hellwig wrote: > On Sun, Aug 27, 2023 at 10:45:18PM +0100, Al Viro wrote: > > IOW, I suspect that the right thing to do would be something along the lines > > of > > The idea looks sensible to me, but we'll also need to do it for the > filemap_write_and_wait_range failure case. Huh? That's precisely where this patch is doing that... That function in mainline is if (unlikely(buffered_written < 0)) { if (direct_written) return direct_written; return buffered_written; } /* * We need to ensure that the page cache pages are written to disk and * invalidated to preserve the expected O_DIRECT semantics. */ err = filemap_write_and_wait_range(mapping, pos, end); if (err < 0) { /* * We don't know how much we wrote, so just return the number of * bytes which were direct-written */ if (direct_written) return direct_written; return err; } invalidate_mapping_pages(mapping, pos >> PAGE_SHIFT, end >> PAGE_SHIFT); return direct_written + buffered_written; The first failure exit does not need any work - the caller had not bumped ->ki_pos; the second one (after that 'if (err < 0) {' line) does and that's where the patch upthread adds iocb->ki_pos -= buffered_written. Or am I completely misparsing what you've written?