From patchwork Thu Mar 23 00:36:56 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jan Kara X-Patchwork-Id: 9640301 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 87A12602D6 for ; Thu, 23 Mar 2017 00:37:12 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 79BE125EA6 for ; Thu, 23 Mar 2017 00:37:12 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 6E74E284E8; Thu, 23 Mar 2017 00:37:12 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 13A152842C for ; Thu, 23 Mar 2017 00:37:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754199AbdCWAhL (ORCPT ); Wed, 22 Mar 2017 20:37:11 -0400 Received: from mx2.suse.de ([195.135.220.15]:56939 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752004AbdCWAhJ (ORCPT ); Wed, 22 Mar 2017 20:37:09 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay1.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 840CBAAB9; Thu, 23 Mar 2017 00:37:07 +0000 (UTC) Received: by quack2.suse.cz (Postfix, from userid 1000) id 887311E1182; Thu, 23 Mar 2017 01:37:05 +0100 (CET) From: Jan Kara To: Jens Axboe Cc: linux-block@vger.kernel.org, Christoph Hellwig , Dan Williams , Thiago Jung Bauermann , Tejun Heo , Tahsin Erdogan , Omar Sandoval , Jan Kara Subject: [PATCH 04/10] bdi: Unify bdi->wb_list handling for root wb_writeback Date: Thu, 23 Mar 2017 01:36:56 +0100 Message-Id: <20170323003702.27571-5-jack@suse.cz> X-Mailer: git-send-email 2.10.2 In-Reply-To: <20170323003702.27571-1-jack@suse.cz> References: <20170323003702.27571-1-jack@suse.cz> Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Currently root wb_writeback structure is added to bdi->wb_list in bdi_init() and never removed. That is different from all other wb_writeback structures which get added to the list when created and removed from it before wb_shutdown(). So move list addition of root bdi_writeback to bdi_register() and list removal of all wb_writeback structures to wb_shutdown(). That way a wb_writeback structure is on bdi->wb_list if and only if it can handle writeback and it will make it easier for us to handle shutdown of all wb_writeback structures in bdi_unregister(). Acked-by: Tejun Heo Signed-off-by: Jan Kara --- mm/backing-dev.c | 34 ++++++++++++++++++++++++++++------ 1 file changed, 28 insertions(+), 6 deletions(-) diff --git a/mm/backing-dev.c b/mm/backing-dev.c index 03d4ba27c133..e3d56dba4da8 100644 --- a/mm/backing-dev.c +++ b/mm/backing-dev.c @@ -345,6 +345,8 @@ static int wb_init(struct bdi_writeback *wb, struct backing_dev_info *bdi, return err; } +static void cgwb_remove_from_bdi_list(struct bdi_writeback *wb); + /* * Remove bdi from the global list and shutdown any threads we have running */ @@ -358,6 +360,7 @@ static void wb_shutdown(struct bdi_writeback *wb) } spin_unlock_bh(&wb->work_lock); + cgwb_remove_from_bdi_list(wb); /* * Drain work list and shutdown the delayed_work. !WB_registered * tells wb_workfn() that @wb is dying and its work_list needs to @@ -491,10 +494,6 @@ static void cgwb_release_workfn(struct work_struct *work) release_work); struct backing_dev_info *bdi = wb->bdi; - spin_lock_irq(&cgwb_lock); - list_del_rcu(&wb->bdi_node); - spin_unlock_irq(&cgwb_lock); - wb_shutdown(wb); css_put(wb->memcg_css); @@ -526,6 +525,13 @@ static void cgwb_kill(struct bdi_writeback *wb) percpu_ref_kill(&wb->refcnt); } +static void cgwb_remove_from_bdi_list(struct bdi_writeback *wb) +{ + spin_lock_irq(&cgwb_lock); + list_del_rcu(&wb->bdi_node); + spin_unlock_irq(&cgwb_lock); +} + static int cgwb_create(struct backing_dev_info *bdi, struct cgroup_subsys_state *memcg_css, gfp_t gfp) { @@ -766,6 +772,13 @@ static void cgwb_bdi_exit(struct backing_dev_info *bdi) spin_unlock_irq(&cgwb_lock); } +static void cgwb_bdi_register(struct backing_dev_info *bdi) +{ + spin_lock_irq(&cgwb_lock); + list_add_tail_rcu(&bdi->wb.bdi_node, &bdi->wb_list); + spin_unlock_irq(&cgwb_lock); +} + #else /* CONFIG_CGROUP_WRITEBACK */ static int cgwb_bdi_init(struct backing_dev_info *bdi) @@ -793,6 +806,16 @@ static void cgwb_bdi_exit(struct backing_dev_info *bdi) wb_congested_put(bdi->wb_congested); } +static void cgwb_bdi_register(struct backing_dev_info *bdi) +{ + list_add_tail_rcu(&bdi->wb.bdi_node, &bdi->wb_list); +} + +static void cgwb_remove_from_bdi_list(struct bdi_writeback *wb) +{ + list_del_rcu(&wb->bdi_node); +} + #endif /* CONFIG_CGROUP_WRITEBACK */ int bdi_init(struct backing_dev_info *bdi) @@ -811,8 +834,6 @@ int bdi_init(struct backing_dev_info *bdi) ret = cgwb_bdi_init(bdi); - list_add_tail_rcu(&bdi->wb.bdi_node, &bdi->wb_list); - return ret; } EXPORT_SYMBOL(bdi_init); @@ -848,6 +869,7 @@ int bdi_register(struct backing_dev_info *bdi, struct device *parent, if (IS_ERR(dev)) return PTR_ERR(dev); + cgwb_bdi_register(bdi); bdi->dev = dev; bdi_debug_register(bdi, dev_name(dev));