Commit e8cb72b3 authored by Jan Kara's avatar Jan Kara Committed by Jens Axboe

bdi: Unify bdi->wb_list handling for root wb_writeback

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: default avatarTejun Heo <tj@kernel.org>
Signed-off-by: default avatarJan Kara <jack@suse.cz>
Signed-off-by: default avatarJens Axboe <axboe@fb.com>
parent 810df54a
...@@ -345,6 +345,8 @@ static int wb_init(struct bdi_writeback *wb, struct backing_dev_info *bdi, ...@@ -345,6 +345,8 @@ static int wb_init(struct bdi_writeback *wb, struct backing_dev_info *bdi,
return err; 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 * 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) ...@@ -358,6 +360,7 @@ static void wb_shutdown(struct bdi_writeback *wb)
} }
spin_unlock_bh(&wb->work_lock); spin_unlock_bh(&wb->work_lock);
cgwb_remove_from_bdi_list(wb);
/* /*
* Drain work list and shutdown the delayed_work. !WB_registered * Drain work list and shutdown the delayed_work. !WB_registered
* tells wb_workfn() that @wb is dying and its work_list needs to * 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) ...@@ -491,10 +494,6 @@ static void cgwb_release_workfn(struct work_struct *work)
release_work); release_work);
struct backing_dev_info *bdi = wb->bdi; 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); wb_shutdown(wb);
css_put(wb->memcg_css); css_put(wb->memcg_css);
...@@ -526,6 +525,13 @@ static void cgwb_kill(struct bdi_writeback *wb) ...@@ -526,6 +525,13 @@ static void cgwb_kill(struct bdi_writeback *wb)
percpu_ref_kill(&wb->refcnt); 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, static int cgwb_create(struct backing_dev_info *bdi,
struct cgroup_subsys_state *memcg_css, gfp_t gfp) struct cgroup_subsys_state *memcg_css, gfp_t gfp)
{ {
...@@ -766,6 +772,13 @@ static void cgwb_bdi_exit(struct backing_dev_info *bdi) ...@@ -766,6 +772,13 @@ static void cgwb_bdi_exit(struct backing_dev_info *bdi)
spin_unlock_irq(&cgwb_lock); 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 */ #else /* CONFIG_CGROUP_WRITEBACK */
static int cgwb_bdi_init(struct backing_dev_info *bdi) static int cgwb_bdi_init(struct backing_dev_info *bdi)
...@@ -793,6 +806,16 @@ static void cgwb_bdi_exit(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); 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 */ #endif /* CONFIG_CGROUP_WRITEBACK */
int bdi_init(struct backing_dev_info *bdi) int bdi_init(struct backing_dev_info *bdi)
...@@ -811,8 +834,6 @@ 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); ret = cgwb_bdi_init(bdi);
list_add_tail_rcu(&bdi->wb.bdi_node, &bdi->wb_list);
return ret; return ret;
} }
EXPORT_SYMBOL(bdi_init); EXPORT_SYMBOL(bdi_init);
...@@ -848,6 +869,7 @@ int bdi_register(struct backing_dev_info *bdi, struct device *parent, ...@@ -848,6 +869,7 @@ int bdi_register(struct backing_dev_info *bdi, struct device *parent,
if (IS_ERR(dev)) if (IS_ERR(dev))
return PTR_ERR(dev); return PTR_ERR(dev);
cgwb_bdi_register(bdi);
bdi->dev = dev; bdi->dev = dev;
bdi_debug_register(bdi, dev_name(dev)); bdi_debug_register(bdi, dev_name(dev));
......
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