[PATCH v8 4/8] writeback, cgroup: switch to rcu_work API in inode_switch_wbs()
From: Roman Gushchin <hidden>
Date: 2021-06-08 01:31:43
Also in:
cgroups, linux-fsdevel, lkml
Subsystem:
filesystems (vfs and infrastructure), the rest · Maintainers:
Alexander Viro, Christian Brauner, Linus Torvalds
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 <redacted> Reviewed-by: Jan Kara <jack@suse.cz> Acked-by: Tejun Heo <tj@kernel.org> Acked-by: Dennis Zhou <dennis@kernel.org> --- 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; - 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(struct backing_dev_info *bdi) 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 @@ static void inode_switch_wbs_work_fn(struct work_struct *work) 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 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; out_free:
--
2.31.1