From mboxrd@z Thu Jan 1 00:00:00 1970 From: Roman Gushchin Subject: [PATCH v8 4/8] writeback, cgroup: switch to rcu_work API in inode_switch_wbs() Date: Mon, 7 Jun 2021 18:31:19 -0700 Message-ID: <20210608013123.1088882-5-guro@fb.com> References: <20210608013123.1088882-1-guro@fb.com> Mime-Version: 1.0 Content-Transfer-Encoding: quoted-printable Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding : content-type; s=facebook; bh=VOS/cMlJuOP4R8dV3BlKjWy3sUpbjMUwJr4NHNPxER8=; b=UoOInWK62It3F5fZMJ6KYCjtLeW0WB0HC8bX83PE451a4VGo+dcN8KfOEr5xP0d7BaaN AKpYqquQkL+DZtfKVfCqRCL73NkIa3TPJoaHSNQKRBNT+sI36+8twRbmZVX7NaVX9ZiP Ri0kQqbmMo1LdF7OKkyMG09q9jK3zJ/FRCo= In-Reply-To: <20210608013123.1088882-1-guro@fb.com> List-ID: Content-Type: text/plain; charset="us-ascii" To: Jan Kara , Tejun Heo Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Alexander Viro , Dennis Zhou , Dave Chinner , cgroups@vger.kernel.org, Roman Gushchin 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. Signed-off-by: Roman Gushchin Reviewed-by: Jan Kara Acked-by: Tejun Heo Acked-by: Dennis Zhou --- fs/fs-writeback.c | 18 ++++-------------- 1 file changed, 4 insertions(+), 14 deletions(-) diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index e2cc860a001b..96974e13a203 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -335,8 +335,7 @@ struct inode_switch_wbs_context { struct inode *inode; struct bdi_writeback *new_wb; =20 - struct rcu_head rcu_head; - struct work_struct work; + struct rcu_work work; }; =20 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(struct backi= ng_dev_info *bdi) static void inode_switch_wbs_work_fn(struct work_struct *work) { struct inode_switch_wbs_context *isw =3D - container_of(work, struct inode_switch_wbs_context, work); + container_of(to_rcu_work(work), struct inode_switch_wbs_context, work)= ; struct inode *inode =3D isw->inode; struct backing_dev_info *bdi =3D inode_to_bdi(inode); struct address_space *mapping =3D inode->i_mapping; @@ -469,16 +468,6 @@ static void inode_switch_wbs_work_fn(struct work_str= uct *work) atomic_dec(&isw_nr_in_flight); } =20 -static void inode_switch_wbs_rcu_fn(struct rcu_head *rcu_head) -{ - struct inode_switch_wbs_context *isw =3D 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 inode *inode, int= new_wb_id) * 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; =20 out_free: --=20 2.31.1