linux-master/mm/backing-dev.c

59 	bdi_debug_root = debugfs_create_dir("bdi", NULL);
87 static void bdi_collect_stats(struct backing_dev_info *bdi,
93 	list_for_each_entry_rcu(wb, &bdi->wb_list, bdi_node) {
103 static void bdi_collect_stats(struct backing_dev_info *bdi,
106 	collect_wb_stats(stats, &bdi->wb);
112 	struct backing_dev_info *bdi = m->private;
122 	bdi_collect_stats(bdi, &stats);
123 	tot_bw = atomic_long_read(&bdi->tot_write_bandwidth);
152 		   !list_empty(&bdi->bdi_list), bdi->wb.state);
195 	struct backing_dev_info *bdi = m->private;
203 	list_for_each_entry_rcu(wb, &bdi->wb_list, bdi_node) {
233 static void bdi_debug_register(struct backing_dev_info *bdi, const char *name)
235 	bdi->debug_dir = debugfs_create_dir(name, bdi_debug_root);
237 	debugfs_create_file("stats", 0444, bdi->debug_dir, bdi,
239 	debugfs_create_file("wb_stats", 0444, bdi->debug_dir, bdi,
243 static void bdi_debug_unregister(struct backing_dev_info *bdi)
245 	debugfs_remove_recursive(bdi->debug_dir);
251 static inline void bdi_debug_register(struct backing_dev_info *bdi,
255 static inline void bdi_debug_unregister(struct backing_dev_info *bdi)
264 	struct backing_dev_info *bdi = dev_get_drvdata(dev);
272 	bdi->ra_pages = read_ahead_kb >> (PAGE_SHIFT - 10);
281 	struct backing_dev_info *bdi = dev_get_drvdata(dev);		\
287 BDI_SHOW(read_ahead_kb, K(bdi->ra_pages))
292 	struct backing_dev_info *bdi = dev_get_drvdata(dev);
300 	ret = bdi_set_min_ratio(bdi, ratio);
306 BDI_SHOW(min_ratio, bdi->min_ratio / BDI_RATIO_SCALE)
311 	struct backing_dev_info *bdi = dev_get_drvdata(dev);
319 	ret = bdi_set_min_ratio_no_scale(bdi, ratio);
325 BDI_SHOW(min_ratio_fine, bdi->min_ratio)
330 	struct backing_dev_info *bdi = dev_get_drvdata(dev);
338 	ret = bdi_set_max_ratio(bdi, ratio);
344 BDI_SHOW(max_ratio, bdi->max_ratio / BDI_RATIO_SCALE)
349 	struct backing_dev_info *bdi = dev_get_drvdata(dev);
357 	ret = bdi_set_max_ratio_no_scale(bdi, ratio);
363 BDI_SHOW(max_ratio_fine, bdi->max_ratio)
369 	struct backing_dev_info *bdi = dev_get_drvdata(dev);
371 	return sysfs_emit(buf, "%llu\n", bdi_get_min_bytes(bdi));
377 	struct backing_dev_info *bdi = dev_get_drvdata(dev);
385 	ret = bdi_set_min_bytes(bdi, bytes);
397 	struct backing_dev_info *bdi = dev_get_drvdata(dev);
399 	return sysfs_emit(buf, "%llu\n", bdi_get_max_bytes(bdi));
405 	struct backing_dev_info *bdi = dev_get_drvdata(dev);
413 	ret = bdi_set_max_bytes(bdi, bytes);
434 	struct backing_dev_info *bdi = dev_get_drvdata(dev);
442 	ret = bdi_set_strict_limit(bdi, strict_limit);
452 	struct backing_dev_info *bdi = dev_get_drvdata(dev);
455 			!!(bdi->capabilities & BDI_CAP_STRICTLIMIT));
474 	.name		= "bdi",
515 static int wb_init(struct bdi_writeback *wb, struct backing_dev_info *bdi,
522 	wb->bdi = bdi;
556  * Remove bdi from the global list and shutdown any threads we have running
592  * cgwb_lock protects bdi->cgwb_tree, blkcg->cgwb_list, offline_cgwbs and
593  * memcg->cgwb_list.  bdi->cgwb_tree is also RCU protected.
615 	struct backing_dev_info *bdi = wb->bdi;
617 	mutex_lock(&wb->bdi->cgwb_release_mutex);
622 	mutex_unlock(&wb->bdi->cgwb_release_mutex);
634 	bdi_put(bdi);
650 	WARN_ON(!radix_tree_delete(&wb->bdi->cgwb_tree, wb->memcg_css->id));
664 static int cgwb_create(struct backing_dev_info *bdi,
681 	wb = radix_tree_lookup(&bdi->cgwb_tree, memcg_css->id);
697 	ret = wb_init(wb, bdi, gfp);
714 	bdi_get(bdi);
717 	 * The root wb determines the registered state of the whole bdi and
724 	if (test_bit(WB_registered, &bdi->wb.state) &&
727 		ret = radix_tree_insert(&bdi->cgwb_tree, memcg_css->id, wb);
729 			list_add_tail_rcu(&wb->bdi_node, &bdi->wb_list);
746 	bdi_put(bdi);
761  * @bdi: target bdi
764  * Try to get the wb for @memcg_css on @bdi.  The returned wb has its
782 struct bdi_writeback *wb_get_lookup(struct backing_dev_info *bdi,
788 		return &bdi->wb;
791 	wb = radix_tree_lookup(&bdi->cgwb_tree, memcg_css->id);
808  * @bdi: target bdi
812  * Try to get the wb for @memcg_css on @bdi.  If it doesn't exist, try to
815 struct bdi_writeback *wb_get_create(struct backing_dev_info *bdi,
824 		wb = wb_get_lookup(bdi, memcg_css);
825 	} while (!wb && !cgwb_create(bdi, memcg_css, gfp));
830 static int cgwb_bdi_init(struct backing_dev_info *bdi)
834 	INIT_RADIX_TREE(&bdi->cgwb_tree, GFP_ATOMIC);
835 	mutex_init(&bdi->cgwb_release_mutex);
836 	init_rwsem(&bdi->wb_switch_rwsem);
838 	ret = wb_init(&bdi->wb, bdi, GFP_KERNEL);
840 		bdi->wb.memcg_css = &root_mem_cgroup->css;
841 		bdi->wb.blkcg_css = blkcg_root_css;
846 static void cgwb_bdi_unregister(struct backing_dev_info *bdi)
852 	WARN_ON(test_bit(WB_registered, &bdi->wb.state));
855 	radix_tree_for_each_slot(slot, &bdi->cgwb_tree, &iter, 0)
859 	mutex_lock(&bdi->cgwb_release_mutex);
861 	while (!list_empty(&bdi->wb_list)) {
862 		wb = list_first_entry(&bdi->wb_list, struct bdi_writeback,
869 	mutex_unlock(&bdi->cgwb_release_mutex);
958 static void cgwb_bdi_register(struct backing_dev_info *bdi)
961 	list_add_tail_rcu(&bdi->wb.bdi_node, &bdi->wb_list);
982 static int cgwb_bdi_init(struct backing_dev_info *bdi)
984 	return wb_init(&bdi->wb, bdi, GFP_KERNEL);
987 static void cgwb_bdi_unregister(struct backing_dev_info *bdi) { }
989 static void cgwb_bdi_register(struct backing_dev_info *bdi)
991 	list_add_tail_rcu(&bdi->wb.bdi_node, &bdi->wb_list);
1001 int bdi_init(struct backing_dev_info *bdi)
1003 	bdi->dev = NULL;
1005 	kref_init(&bdi->refcnt);
1006 	bdi->min_ratio = 0;
1007 	bdi->max_ratio = 100 * BDI_RATIO_SCALE;
1008 	bdi->max_prop_frac = FPROP_FRAC_BASE;
1009 	INIT_LIST_HEAD(&bdi->bdi_list);
1010 	INIT_LIST_HEAD(&bdi->wb_list);
1011 	init_waitqueue_head(&bdi->wb_waitq);
1012 	bdi->last_bdp_sleep = jiffies;
1014 	return cgwb_bdi_init(bdi);
1019 	struct backing_dev_info *bdi;
1021 	bdi = kzalloc_node(sizeof(*bdi), GFP_KERNEL, node_id);
1022 	if (!bdi)
1025 	if (bdi_init(bdi)) {
1026 		kfree(bdi);
1029 	bdi->capabilities = BDI_CAP_WRITEBACK | BDI_CAP_WRITEBACK_ACCT;
1030 	bdi->ra_pages = VM_READAHEAD_PAGES;
1031 	bdi->io_pages = VM_READAHEAD_PAGES;
1032 	timer_setup(&bdi->laptop_mode_wb_timer, laptop_mode_timer_fn, 0);
1033 	return bdi;
1041 	struct backing_dev_info *bdi;
1047 		bdi = rb_entry(parent, struct backing_dev_info, rb_node);
1049 		if (bdi->id > id)
1051 		else if (bdi->id < id)
1063  * bdi_get_by_id - lookup and get bdi from its id
1064  * @id: bdi id to lookup
1066  * Find bdi matching @id and get it.  Returns NULL if the matching bdi
1071 	struct backing_dev_info *bdi = NULL;
1077 		bdi = rb_entry(*p, struct backing_dev_info, rb_node);
1078 		bdi_get(bdi);
1082 	return bdi;
1085 int bdi_register_va(struct backing_dev_info *bdi, const char *fmt, va_list args)
1090 	if (bdi->dev)	/* The driver needs to use separate queues per device */
1093 	vsnprintf(bdi->dev_name, sizeof(bdi->dev_name), fmt, args);
1094 	dev = device_create(&bdi_class, NULL, MKDEV(0, 0), bdi, bdi->dev_name);
1098 	cgwb_bdi_register(bdi);
1099 	bdi->dev = dev;
1101 	bdi_debug_register(bdi, dev_name(dev));
1102 	set_bit(WB_registered, &bdi->wb.state);
1106 	bdi->id = ++bdi_id_cursor;
1108 	p = bdi_lookup_rb_node(bdi->id, &parent);
1109 	rb_link_node(&bdi->rb_node, parent, p);
1110 	rb_insert_color(&bdi->rb_node, &bdi_tree);
1112 	list_add_tail_rcu(&bdi->bdi_list, &bdi_list);
1116 	trace_writeback_bdi_register(bdi);
1120 int bdi_register(struct backing_dev_info *bdi, const char *fmt, ...)
1126 	ret = bdi_register_va(bdi, fmt, args);
1132 void bdi_set_owner(struct backing_dev_info *bdi, struct device *owner)
1134 	WARN_ON_ONCE(bdi->owner);
1135 	bdi->owner = owner;
1140  * Remove bdi from bdi_list, and ensure that it is no longer visible
1142 static void bdi_remove_from_list(struct backing_dev_info *bdi)
1145 	rb_erase(&bdi->rb_node, &bdi_tree);
1146 	list_del_rcu(&bdi->bdi_list);
1152 void bdi_unregister(struct backing_dev_info *bdi)
1154 	del_timer_sync(&bdi->laptop_mode_wb_timer);
1157 	bdi_remove_from_list(bdi);
1158 	wb_shutdown(&bdi->wb);
1159 	cgwb_bdi_unregister(bdi);
1165 	if (bdi->min_ratio)
1166 		bdi_set_min_ratio(bdi, 0);
1168 	if (bdi->dev) {
1169 		bdi_debug_unregister(bdi);
1170 		device_unregister(bdi->dev);
1171 		bdi->dev = NULL;
1174 	if (bdi->owner) {
1175 		put_device(bdi->owner);
1176 		bdi->owner = NULL;
1183 	struct backing_dev_info *bdi =
1186 	WARN_ON_ONCE(test_bit(WB_registered, &bdi->wb.state));
1187 	WARN_ON_ONCE(bdi->dev);
1188 	wb_exit(&bdi->wb);
1189 	kfree(bdi);
1192 void bdi_put(struct backing_dev_info *bdi)
1194 	kref_put(&bdi->refcnt, release_bdi);
1208 		return I_BDEV(inode)->bd_disk->bdi;
1214 const char *bdi_dev_name(struct backing_dev_info *bdi)
1216 	if (!bdi || !bdi->dev)
1218 	return bdi->dev_name;