From patchwork Tue Jun 29 02:35:50 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Morton X-Patchwork-Id: 12348969 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5D781C11F68 for ; Tue, 29 Jun 2021 02:35:53 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 1636D61D04 for ; Tue, 29 Jun 2021 02:35:53 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1636D61D04 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 6C5818D00A6; Mon, 28 Jun 2021 22:35:52 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 69CE08D008F; Mon, 28 Jun 2021 22:35:52 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 58BC58D00A6; Mon, 28 Jun 2021 22:35:52 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0077.hostedemail.com [216.40.44.77]) by kanga.kvack.org (Postfix) with ESMTP id 31BA18D008F for ; Mon, 28 Jun 2021 22:35:52 -0400 (EDT) Received: from smtpin36.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 29363181AEF1D for ; Tue, 29 Jun 2021 02:35:52 +0000 (UTC) X-FDA: 78305196144.36.48862C9 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf25.hostedemail.com (Postfix) with ESMTP id DCDF96000154 for ; Tue, 29 Jun 2021 02:35:51 +0000 (UTC) Received: by mail.kernel.org (Postfix) with ESMTPSA id BEE0061D06; Tue, 29 Jun 2021 02:35:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1624934151; bh=VGav/tkE0QI1l9HkDfafC24jxBHD9yXTvlcCS3ak+EU=; h=Date:From:To:Subject:In-Reply-To:From; b=affyLGktyJybK8PrumwQLX6BBN81aG1BRzPOQ3QKhDh110rSAcThRXi9S1s57uooO ay/9APEyE/pLXezHxYSvzCAMMLDIuEK+YciB7/91oMcNltopcLsy4WxSLMzgLHS1I6 oUOmn2uXhcItCXOU4OFUblM4XyogKlzQhTPWHK4k= Date: Mon, 28 Jun 2021 19:35:50 -0700 From: Andrew Morton To: akpm@linux-foundation.org, axboe@kernel.dk, dchinner@redhat.com, dennis@kernel.org, guro@fb.com, jack@suse.com, jack@suse.cz, linux-mm@kvack.org, mm-commits@vger.kernel.org, tj@kernel.org, torvalds@linux-foundation.org, viro@zeniv.linux.org.uk Subject: [patch 049/192] writeback, cgroup: switch to rcu_work API in inode_switch_wbs() Message-ID: <20210629023550.CRUufnTAT%akpm@linux-foundation.org> In-Reply-To: <20210628193256.008961950a714730751c1423@linux-foundation.org> User-Agent: s-nail v14.8.16 Authentication-Results: imf25.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=affyLGkt; spf=pass (imf25.hostedemail.com: domain of akpm@linux-foundation.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org; dmarc=none X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: DCDF96000154 X-Stat-Signature: dfwsuxug4miwnd3kb8b68dkuz1ao3e1d X-HE-Tag: 1624934151-74595 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: From: Roman Gushchin Subject: writeback, cgroup: switch to rcu_work API in inode_switch_wbs() Inode's wb switching requires two steps divided by an RCU grace period. It's currently implemented as an RCU callback inode_switch_wbs_rcu_fn(), which schedules inode_switch_wbs_work_fn() as a work. Switching to the rcu_work API allows to do the same in a cleaner and slightly shorter form. Link: https://lkml.kernel.org/r/20210608230225.2078447-5-guro@fb.com Signed-off-by: Roman Gushchin Reviewed-by: Jan Kara Acked-by: Tejun Heo Acked-by: Dennis Zhou Cc: Alexander Viro Cc: Dave Chinner Cc: Jan Kara Cc: Jens Axboe Signed-off-by: Andrew Morton --- fs/fs-writeback.c | 18 ++++-------------- 1 file changed, 4 insertions(+), 14 deletions(-) --- a/fs/fs-writeback.c~writeback-cgroup-switch-to-rcu_work-api-in-inode_switch_wbs +++ a/fs/fs-writeback.c @@ -335,8 +335,7 @@ struct inode_switch_wbs_context { struct inode *inode; struct bdi_writeback *new_wb; - struct rcu_head rcu_head; - struct work_struct work; + struct rcu_work work; }; static void bdi_down_write_wb_switch_rwsem(struct backing_dev_info *bdi) @@ -352,7 +351,7 @@ static void bdi_up_write_wb_switch_rwsem static void inode_switch_wbs_work_fn(struct work_struct *work) { struct inode_switch_wbs_context *isw = - container_of(work, struct inode_switch_wbs_context, work); + container_of(to_rcu_work(work), struct inode_switch_wbs_context, work); struct inode *inode = isw->inode; struct backing_dev_info *bdi = inode_to_bdi(inode); struct address_space *mapping = inode->i_mapping; @@ -469,16 +468,6 @@ skip_switch: atomic_dec(&isw_nr_in_flight); } -static void inode_switch_wbs_rcu_fn(struct rcu_head *rcu_head) -{ - struct inode_switch_wbs_context *isw = container_of(rcu_head, - struct inode_switch_wbs_context, rcu_head); - - /* needs to grab bh-unsafe locks, bounce to work item */ - INIT_WORK(&isw->work, inode_switch_wbs_work_fn); - queue_work(isw_wq, &isw->work); -} - /** * inode_switch_wbs - change the wb association of an inode * @inode: target inode @@ -536,7 +525,8 @@ static void inode_switch_wbs(struct inod * lock so that stat transfer can synchronize against them. * Let's continue after I_WB_SWITCH is guaranteed to be visible. */ - call_rcu(&isw->rcu_head, inode_switch_wbs_rcu_fn); + INIT_RCU_WORK(&isw->work, inode_switch_wbs_work_fn); + queue_rcu_work(isw_wq, &isw->work); return; out_free: