Merge "bdi: Do not wait for cgwbs release in bdi_unregister()" (072c521e) · Commits · e / devices / android_kernel_fairphone_FP3

include/linux/backing-dev-defs.h

+0 −1

Original line number	Diff line number	Diff line
		@@ -161,7 +161,6 @@ struct backing_dev_info {
		#ifdef CONFIG_CGROUP_WRITEBACK
		struct radix_tree_root cgwb_tree; /* radix tree of active cgroup wbs */
		struct rb_root cgwb_congested_tree; /* their congested states */
		atomic_t usage_cnt; /* counts both cgwbs and cgwb_contested's */
		#else
		struct bdi_writeback_congested *wb_congested;
		#endif

mm/backing-dev.c

+1 −21

Original line number	Diff line number	Diff line
		@@ -405,11 +405,9 @@ static void wb_exit(struct bdi_writeback *wb)
		/*
		* cgwb_lock protects bdi->cgwb_tree, bdi->cgwb_congested_tree,
		* blkcg->cgwb_list, and memcg->cgwb_list. bdi->cgwb_tree is also RCU
		* protected. cgwb_release_wait is used to wait for the completion of cgwb
		* releases from bdi destruction path.
		* protected.
		*/
		static DEFINE_SPINLOCK(cgwb_lock);
		static DECLARE_WAIT_QUEUE_HEAD(cgwb_release_wait);

		/**
		* wb_congested_get_create - get or create a wb_congested
		@@ -504,7 +502,6 @@ static void cgwb_release_workfn(struct work_struct *work)
		{
		struct bdi_writeback *wb = container_of(work, struct bdi_writeback,
		release_work);
		struct backing_dev_info *bdi = wb->bdi;

		wb_shutdown(wb);

		@@ -515,9 +512,6 @@ static void cgwb_release_workfn(struct work_struct *work)
		percpu_ref_exit(&wb->refcnt);
		wb_exit(wb);
		kfree_rcu(wb, rcu);

		if (atomic_dec_and_test(&bdi->usage_cnt))
		wake_up_all(&cgwb_release_wait);
		}

		static void cgwb_release(struct percpu_ref *refcnt)
		@@ -607,7 +601,6 @@ static int cgwb_create(struct backing_dev_info *bdi,
		/* we might have raced another instance of this function */
		ret = radix_tree_insert(&bdi->cgwb_tree, memcg_css->id, wb);
		if (!ret) {
		atomic_inc(&bdi->usage_cnt);
		list_add_tail_rcu(&wb->bdi_node, &bdi->wb_list);
		list_add(&wb->memcg_node, memcg_cgwb_list);
		list_add(&wb->blkcg_node, blkcg_cgwb_list);
		@@ -697,7 +690,6 @@ static int cgwb_bdi_init(struct backing_dev_info *bdi)

		INIT_RADIX_TREE(&bdi->cgwb_tree, GFP_ATOMIC);
		bdi->cgwb_congested_tree = RB_ROOT;
		atomic_set(&bdi->usage_cnt, 1);

		ret = wb_init(&bdi->wb, bdi, 1, GFP_KERNEL);
		if (!ret) {
		@@ -727,18 +719,6 @@ static void cgwb_bdi_destroy(struct backing_dev_info *bdi)
		spin_lock_irq(&cgwb_lock);
		}
		spin_unlock_irq(&cgwb_lock);

		/*
		* All cgwb's must be shutdown and released before returning. Drain
		* the usage counter to wait for all cgwb's ever created on @bdi.
		*/
		atomic_dec(&bdi->usage_cnt);
		wait_event(cgwb_release_wait, !atomic_read(&bdi->usage_cnt));
		/*
		* Grab back our reference so that we hold it when @bdi gets
		* re-registered.
		*/
		atomic_inc(&bdi->usage_cnt);
		}

		/**