linux-master/mm/backing-dev.c

46 	bdi_debug_root = debugfs_create_dir("bdi", NULL);
51 	struct backing_dev_info *bdi = m->private;
52 	struct bdi_writeback *wb = &bdi->wb;
102 		   !list_empty(&bdi->bdi_list), bdi->wb.state);
108 static void bdi_debug_register(struct backing_dev_info *bdi, const char *name)
110 	bdi->debug_dir = debugfs_create_dir(name, bdi_debug_root);
112 	debugfs_create_file("stats", 0444, bdi->debug_dir, bdi,
116 static void bdi_debug_unregister(struct backing_dev_info *bdi)
118 	debugfs_remove_recursive(bdi->debug_dir);
124 static inline void bdi_debug_register(struct backing_dev_info *bdi,
128 static inline void bdi_debug_unregister(struct backing_dev_info *bdi)
137 	struct backing_dev_info *bdi = dev_get_drvdata(dev);
145 	bdi->ra_pages = read_ahead_kb >> (PAGE_SHIFT - 10);
154 	struct backing_dev_info *bdi = dev_get_drvdata(dev);		\
160 BDI_SHOW(read_ahead_kb, K(bdi->ra_pages))
165 	struct backing_dev_info *bdi = dev_get_drvdata(dev);
173 	ret = bdi_set_min_ratio(bdi, ratio);
179 BDI_SHOW(min_ratio, bdi->min_ratio / BDI_RATIO_SCALE)
184 	struct backing_dev_info *bdi = dev_get_drvdata(dev);
192 	ret = bdi_set_min_ratio_no_scale(bdi, ratio);
198 BDI_SHOW(min_ratio_fine, bdi->min_ratio)
203 	struct backing_dev_info *bdi = dev_get_drvdata(dev);
211 	ret = bdi_set_max_ratio(bdi, ratio);
217 BDI_SHOW(max_ratio, bdi->max_ratio / BDI_RATIO_SCALE)
222 	struct backing_dev_info *bdi = dev_get_drvdata(dev);
230 	ret = bdi_set_max_ratio_no_scale(bdi, ratio);
236 BDI_SHOW(max_ratio_fine, bdi->max_ratio)
242 	struct backing_dev_info *bdi = dev_get_drvdata(dev);
244 	return sysfs_emit(buf, "%llu\n", bdi_get_min_bytes(bdi));
250 	struct backing_dev_info *bdi = dev_get_drvdata(dev);
258 	ret = bdi_set_min_bytes(bdi, bytes);
270 	struct backing_dev_info *bdi = dev_get_drvdata(dev);
272 	return sysfs_emit(buf, "%llu\n", bdi_get_max_bytes(bdi));
278 	struct backing_dev_info *bdi = dev_get_drvdata(dev);
286 	ret = bdi_set_max_bytes(bdi, bytes);
307 	struct backing_dev_info *bdi = dev_get_drvdata(dev);
315 	ret = bdi_set_strict_limit(bdi, strict_limit);
325 	struct backing_dev_info *bdi = dev_get_drvdata(dev);
328 			!!(bdi->capabilities & BDI_CAP_STRICTLIMIT));
347 	.name		= "bdi",
388 static int wb_init(struct bdi_writeback *wb, struct backing_dev_info *bdi,
395 	wb->bdi = bdi;
437  * Remove bdi from the global list and shutdown any threads we have running
478  * cgwb_lock protects bdi->cgwb_tree, blkcg->cgwb_list, offline_cgwbs and
479  * memcg->cgwb_list.  bdi->cgwb_tree is also RCU protected.
501 	struct backing_dev_info *bdi = wb->bdi;
503 	mutex_lock(&wb->bdi->cgwb_release_mutex);
508 	mutex_unlock(&wb->bdi->cgwb_release_mutex);
520 	bdi_put(bdi);
536 	WARN_ON(!radix_tree_delete(&wb->bdi->cgwb_tree, wb->memcg_css->id));
550 static int cgwb_create(struct backing_dev_info *bdi,
567 	wb = radix_tree_lookup(&bdi->cgwb_tree, memcg_css->id);
583 	ret = wb_init(wb, bdi, gfp);
600 	bdi_get(bdi);
603 	 * The root wb determines the registered state of the whole bdi and
610 	if (test_bit(WB_registered, &bdi->wb.state) &&
613 		ret = radix_tree_insert(&bdi->cgwb_tree, memcg_css->id, wb);
615 			list_add_tail_rcu(&wb->bdi_node, &bdi->wb_list);
632 	bdi_put(bdi);
647  * @bdi: target bdi
650  * Try to get the wb for @memcg_css on @bdi.  The returned wb has its
668 struct bdi_writeback *wb_get_lookup(struct backing_dev_info *bdi,
674 		return &bdi->wb;
677 	wb = radix_tree_lookup(&bdi->cgwb_tree, memcg_css->id);
694  * @bdi: target bdi
698  * Try to get the wb for @memcg_css on @bdi.  If it doesn't exist, try to
701 struct bdi_writeback *wb_get_create(struct backing_dev_info *bdi,
710 		wb = wb_get_lookup(bdi, memcg_css);
711 	} while (!wb && !cgwb_create(bdi, memcg_css, gfp));
716 static int cgwb_bdi_init(struct backing_dev_info *bdi)
720 	INIT_RADIX_TREE(&bdi->cgwb_tree, GFP_ATOMIC);
721 	mutex_init(&bdi->cgwb_release_mutex);
722 	init_rwsem(&bdi->wb_switch_rwsem);
724 	ret = wb_init(&bdi->wb, bdi, GFP_KERNEL);
726 		bdi->wb.memcg_css = &root_mem_cgroup->css;
727 		bdi->wb.blkcg_css = blkcg_root_css;
732 static void cgwb_bdi_unregister(struct backing_dev_info *bdi)
738 	WARN_ON(test_bit(WB_registered, &bdi->wb.state));
741 	radix_tree_for_each_slot(slot, &bdi->cgwb_tree, &iter, 0)
745 	mutex_lock(&bdi->cgwb_release_mutex);
747 	while (!list_empty(&bdi->wb_list)) {
748 		wb = list_first_entry(&bdi->wb_list, struct bdi_writeback,
755 	mutex_unlock(&bdi->cgwb_release_mutex);
844 static void cgwb_bdi_register(struct backing_dev_info *bdi)
847 	list_add_tail_rcu(&bdi->wb.bdi_node, &bdi->wb_list);
868 static int cgwb_bdi_init(struct backing_dev_info *bdi)
870 	return wb_init(&bdi->wb, bdi, GFP_KERNEL);
873 static void cgwb_bdi_unregister(struct backing_dev_info *bdi) { }
875 static void cgwb_bdi_register(struct backing_dev_info *bdi)
877 	list_add_tail_rcu(&bdi->wb.bdi_node, &bdi->wb_list);
887 int bdi_init(struct backing_dev_info *bdi)
889 	bdi->dev = NULL;
891 	kref_init(&bdi->refcnt);
892 	bdi->min_ratio = 0;
893 	bdi->max_ratio = 100 * BDI_RATIO_SCALE;
894 	bdi->max_prop_frac = FPROP_FRAC_BASE;
895 	INIT_LIST_HEAD(&bdi->bdi_list);
896 	INIT_LIST_HEAD(&bdi->wb_list);
897 	init_waitqueue_head(&bdi->wb_waitq);
898 	bdi->last_bdp_sleep = jiffies;
900 	return cgwb_bdi_init(bdi);
905 	struct backing_dev_info *bdi;
907 	bdi = kzalloc_node(sizeof(*bdi), GFP_KERNEL, node_id);
908 	if (!bdi)
911 	if (bdi_init(bdi)) {
912 		kfree(bdi);
915 	bdi->capabilities = BDI_CAP_WRITEBACK | BDI_CAP_WRITEBACK_ACCT;
916 	bdi->ra_pages = VM_READAHEAD_PAGES;
917 	bdi->io_pages = VM_READAHEAD_PAGES;
918 	timer_setup(&bdi->laptop_mode_wb_timer, laptop_mode_timer_fn, 0);
919 	return bdi;
927 	struct backing_dev_info *bdi;
933 		bdi = rb_entry(parent, struct backing_dev_info, rb_node);
935 		if (bdi->id > id)
937 		else if (bdi->id < id)
949  * bdi_get_by_id - lookup and get bdi from its id
950  * @id: bdi id to lookup
952  * Find bdi matching @id and get it.  Returns NULL if the matching bdi
957 	struct backing_dev_info *bdi = NULL;
963 		bdi = rb_entry(*p, struct backing_dev_info, rb_node);
964 		bdi_get(bdi);
968 	return bdi;
971 int bdi_register_va(struct backing_dev_info *bdi, const char *fmt, va_list args)
976 	if (bdi->dev)	/* The driver needs to use separate queues per device */
979 	vsnprintf(bdi->dev_name, sizeof(bdi->dev_name), fmt, args);
980 	dev = device_create(&bdi_class, NULL, MKDEV(0, 0), bdi, bdi->dev_name);
984 	cgwb_bdi_register(bdi);
985 	bdi->dev = dev;
987 	bdi_debug_register(bdi, dev_name(dev));
988 	set_bit(WB_registered, &bdi->wb.state);
992 	bdi->id = ++bdi_id_cursor;
994 	p = bdi_lookup_rb_node(bdi->id, &parent);
995 	rb_link_node(&bdi->rb_node, parent, p);
996 	rb_insert_color(&bdi->rb_node, &bdi_tree);
998 	list_add_tail_rcu(&bdi->bdi_list, &bdi_list);
1002 	trace_writeback_bdi_register(bdi);
1006 int bdi_register(struct backing_dev_info *bdi, const char *fmt, ...)
1012 	ret = bdi_register_va(bdi, fmt, args);
1018 void bdi_set_owner(struct backing_dev_info *bdi, struct device *owner)
1020 	WARN_ON_ONCE(bdi->owner);
1021 	bdi->owner = owner;
1026  * Remove bdi from bdi_list, and ensure that it is no longer visible
1028 static void bdi_remove_from_list(struct backing_dev_info *bdi)
1031 	rb_erase(&bdi->rb_node, &bdi_tree);
1032 	list_del_rcu(&bdi->bdi_list);
1038 void bdi_unregister(struct backing_dev_info *bdi)
1040 	del_timer_sync(&bdi->laptop_mode_wb_timer);
1043 	bdi_remove_from_list(bdi);
1044 	wb_shutdown(&bdi->wb);
1045 	cgwb_bdi_unregister(bdi);
1051 	if (bdi->min_ratio)
1052 		bdi_set_min_ratio(bdi, 0);
1054 	if (bdi->dev) {
1055 		bdi_debug_unregister(bdi);
1056 		device_unregister(bdi->dev);
1057 		bdi->dev = NULL;
1060 	if (bdi->owner) {
1061 		put_device(bdi->owner);
1062 		bdi->owner = NULL;
1069 	struct backing_dev_info *bdi =
1072 	WARN_ON_ONCE(test_bit(WB_registered, &bdi->wb.state));
1073 	WARN_ON_ONCE(bdi->dev);
1074 	wb_exit(&bdi->wb);
1075 	kfree(bdi);
1078 void bdi_put(struct backing_dev_info *bdi)
1080 	kref_put(&bdi->refcnt, release_bdi);
1094 		return I_BDEV(inode)->bd_disk->bdi;
1100 const char *bdi_dev_name(struct backing_dev_info *bdi)
1102 	if (!bdi || !bdi->dev)
1104 	return bdi->dev_name;