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 C868DC46CD2 for ; Tue, 30 Jan 2024 21:50:21 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 4105F6B0082; Tue, 30 Jan 2024 16:50:21 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 3BFC86B0083; Tue, 30 Jan 2024 16:50:21 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 2873F6B0085; Tue, 30 Jan 2024 16:50:21 -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 190A96B0082 for ; Tue, 30 Jan 2024 16:50:21 -0500 (EST) Received: from smtpin16.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id DD2ED1403AF for ; Tue, 30 Jan 2024 21:50:20 +0000 (UTC) X-FDA: 81737321400.16.80A7A0B Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.223.130]) by imf07.hostedemail.com (Postfix) with ESMTP id 9AC4C4001D for ; Tue, 30 Jan 2024 21:50:18 +0000 (UTC) Authentication-Results: imf07.hostedemail.com; dkim=pass header.d=suse.cz header.s=susede2_rsa header.b="ax/R6xWL"; dkim=pass header.d=suse.cz header.s=susede2_ed25519 header.b=wBvBemPg; dkim=pass header.d=suse.cz header.s=susede2_rsa header.b="ax/R6xWL"; dkim=pass header.d=suse.cz header.s=susede2_ed25519 header.b=wBvBemPg; dmarc=none; spf=pass (imf07.hostedemail.com: domain of jack@suse.cz designates 195.135.223.130 as permitted sender) smtp.mailfrom=jack@suse.cz ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1706651418; 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:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=R6BGLwQfV4ZTDY8KhVPKQs2ZMupmIejtEZwLRmq2W/Q=; b=wxVIIAIMDUZU0fq4dCGHgfDM/xeVD/kh9be1fMjJ8faYMCWXJ/fVgkPNX/t/ypDGCwGZoy kG/RkVfXr+HiVdWrze/Ms9VnfFDlTrEREyy/SoyVdn32i1sd7GhpzVhpyIengfgpHd49y/ FoDpqG2RnY2kOIcaOfez+eQG62g2YJc= ARC-Authentication-Results: i=1; imf07.hostedemail.com; dkim=pass header.d=suse.cz header.s=susede2_rsa header.b="ax/R6xWL"; dkim=pass header.d=suse.cz header.s=susede2_ed25519 header.b=wBvBemPg; dkim=pass header.d=suse.cz header.s=susede2_rsa header.b="ax/R6xWL"; dkim=pass header.d=suse.cz header.s=susede2_ed25519 header.b=wBvBemPg; dmarc=none; spf=pass (imf07.hostedemail.com: domain of jack@suse.cz designates 195.135.223.130 as permitted sender) smtp.mailfrom=jack@suse.cz ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1706651419; a=rsa-sha256; cv=none; b=x/l0CvnUn/xvmufempnY10g0pvCQR6nAnCY6cdxDwS8U5eAxCbPK/0N75T/q9jtF8OPhdL emmbuCseiZM95E6cBBRdS7EcDK0X4hydh3ROS/ndE0PzDP6Jo58j9I15ijyMxJNjGB0xmd TsXhZj0CZzkEP5uXVXl+bWFlCdc6BV8= Received: from imap2.dmz-prg2.suse.org (imap2.dmz-prg2.suse.org [10.150.64.98]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id C0FB521D08; Tue, 30 Jan 2024 21:50:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1706651416; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=R6BGLwQfV4ZTDY8KhVPKQs2ZMupmIejtEZwLRmq2W/Q=; b=ax/R6xWLZiZ+LLZIot0FIJap/K3XocOIEdWYTAgipJY3DbamIVrdTZvBRU6mhXqSxRWyEk uiUMzteWYYRhSd+pbEMGzqh4bwVP5nO3XbD+X83ph8lWoHnIfHgNQHYtiRrVL988xpL2BK E+SGzRjhfugHG18/12sn6pD4chdu+v8= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1706651416; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=R6BGLwQfV4ZTDY8KhVPKQs2ZMupmIejtEZwLRmq2W/Q=; b=wBvBemPgd4P/xuIZtaQYVn+AQruP/OcHBtLyY+zEf5+yRDftUFexYI6LrsGJlhP9dep7VK NS8LhV9VcMMwG6Cg== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1706651416; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=R6BGLwQfV4ZTDY8KhVPKQs2ZMupmIejtEZwLRmq2W/Q=; b=ax/R6xWLZiZ+LLZIot0FIJap/K3XocOIEdWYTAgipJY3DbamIVrdTZvBRU6mhXqSxRWyEk uiUMzteWYYRhSd+pbEMGzqh4bwVP5nO3XbD+X83ph8lWoHnIfHgNQHYtiRrVL988xpL2BK E+SGzRjhfugHG18/12sn6pD4chdu+v8= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1706651416; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=R6BGLwQfV4ZTDY8KhVPKQs2ZMupmIejtEZwLRmq2W/Q=; b=wBvBemPgd4P/xuIZtaQYVn+AQruP/OcHBtLyY+zEf5+yRDftUFexYI6LrsGJlhP9dep7VK NS8LhV9VcMMwG6Cg== Received: from imap2.dmz-prg2.suse.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by imap2.dmz-prg2.suse.org (Postfix) with ESMTPS id AE46C13462; Tue, 30 Jan 2024 21:50:16 +0000 (UTC) Received: from dovecot-director2.suse.de ([10.150.64.162]) by imap2.dmz-prg2.suse.org with ESMTPSA id jdmDKhhvuWWxHAAAn2gu4w (envelope-from ); Tue, 30 Jan 2024 21:50:16 +0000 Received: by quack3.suse.cz (Postfix, from userid 1000) id 1E75FA07F9; Tue, 30 Jan 2024 22:50:16 +0100 (CET) Date: Tue, 30 Jan 2024 22:50:16 +0100 From: Jan Kara To: Christoph Hellwig Cc: Jan Kara , linux-mm@kvack.org, Matthew Wilcox , Jan Kara , David Howells , Brian Foster , Christian Brauner , "Darrick J. Wong" , linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 19/19] writeback: simplify writeback iteration Message-ID: <20240130215016.npofgza5nmoxuw6m@quack3> References: <20240125085758.2393327-1-hch@lst.de> <20240125085758.2393327-20-hch@lst.de> <20240130104605.2i6mmdncuhwwwfin@quack3> <20240130141601.GA31330@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20240130141601.GA31330@lst.de> X-Rspamd-Queue-Id: 9AC4C4001D X-Rspam-User: X-Rspamd-Server: rspam04 X-Stat-Signature: h7omg3hdgb9m64jcehxxhife641dnbh4 X-HE-Tag: 1706651418-758978 X-HE-Meta: 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 ncF7umYe KbEki8uWCc/g7yIFukWLE6TDA/XEOheLASkmQChW1eWUQPXgCWVRc3nXr3D/Fr7Xuql4a88+vz94OlXQi7mgXiwHHd+u38lRelDAIV71ZLAdMaK6G3zddUwZFWvmqXY/KHxzNuS8ZYWMD2TySMrCsfa2TAPM5x0aM7Ba+fjxC7QVJJCkP3FUanYi58vJ0i69+uHwNkt4UYlBJUwz6rpW0NJB42wzeGKvRNUFHk2majOIX2bR8X9kLjo+bHR74hqtajMskjKP35cJdZcClOUsbMtGGMUsKCDkVbRN5 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: List-Subscribe: List-Unsubscribe: On Tue 30-01-24 15:16:01, Christoph Hellwig wrote: > On Tue, Jan 30, 2024 at 11:46:05AM +0100, Jan Kara wrote: > > Looking at it now I'm thinking whether we would not be better off to > > completely dump the 'error' argument of writeback_iter() / > > writeback_iter_next() and just make all .writepage implementations set > > wbc->err directly. But that means touching all the ~20 writepage > > implementations we still have... > > Heh. I actually had an earlier version that looked at wbc->err in > the ->writepages callers. But it felt a bit too ugly. OK. > > > + */ > > > + if (wbc->sync_mode == WB_SYNC_NONE && > > > + (wbc->err || wbc->nr_to_write <= 0)) > > > + goto finish; > > > > I think it would be a bit more comprehensible if we replace the goto with: > > folio_batch_release(&wbc->fbatch); > > if (wbc->range_cyclic) > > mapping->writeback_index = > > folio->index + folio_nr_pages(folio); > > *error = wbc->err; > > return NULL; > > I agree that keeping the logic on when to break and when to set the > writeback_index is good, but duplicating the batch release and error > assignment seems a bit suboptimal. Let me know what you think of the > alternatŃ–ve variant below. Well, batch release needs to be only here because if writeback_get_folio() returns NULL, the batch has been already released by it. So what would be duplicated is only the error assignment. But I'm fine with the version in the following email and actually somewhat prefer it compared the yet another variant you've sent. Honza -- Jan Kara SUSE Labs, CR