230 static void null_del_dev(struct nullb *nullb);
232 static struct nullb *null_find_dev_by_name(const char *name);
337 	if (!dev->nullb)  in nullb_update_nr_hw_queues()
362 	set = dev->nullb->tag_set;  in nullb_update_nr_hw_queues()
444 			null_del_dev(dev->nullb);  in nullb_device_power_store()
581 		null_del_dev(dev->nullb);  in nullb_group_drop_item()
621 static inline int null_cache_active(struct nullb *nullb)  in null_cache_active()  argument
623 	return test_bit(NULLB_DEV_FL_CACHE, &nullb->dev->flags);  in null_cache_active()
815 static void null_free_sector(struct nullb *nullb, sector_t sector,  in null_free_sector()  argument
823 	root = is_cache ? &nullb->dev->cache : &nullb->dev->data;  in null_free_sector()
836 				nullb->dev->curr_cache -= PAGE_SIZE;  in null_free_sector()
841 static struct nullb_page *null_radix_tree_insert(struct nullb *nullb, u64 idx,  in null_radix_tree_insert()  argument
846 	root = is_cache ? &nullb->dev->cache : &nullb->dev->data;  in null_radix_tree_insert()
853 		nullb->dev->curr_cache += PAGE_SIZE;  in null_radix_tree_insert()
887 static struct nullb_page *__null_lookup_page(struct nullb *nullb,  in __null_lookup_page()  argument
898 	root = is_cache ? &nullb->dev->cache : &nullb->dev->data;  in __null_lookup_page()
908 static struct nullb_page *null_lookup_page(struct nullb *nullb,  in null_lookup_page()  argument
914 		page = __null_lookup_page(nullb, sector, for_write, true);  in null_lookup_page()
917 	return __null_lookup_page(nullb, sector, for_write, false);  in null_lookup_page()
920 static struct nullb_page *null_insert_page(struct nullb *nullb,  in null_insert_page()  argument
922 	__releases(&nullb->lock)  in null_insert_page()
923 	__acquires(&nullb->lock)  in null_insert_page()
928 	t_page = null_lookup_page(nullb, sector, true, ignore_cache);  in null_insert_page()
932 	spin_unlock_irq(&nullb->lock);  in null_insert_page()
941 	spin_lock_irq(&nullb->lock);  in null_insert_page()
944 	t_page = null_radix_tree_insert(nullb, idx, t_page, !ignore_cache);  in null_insert_page()
951 	spin_lock_irq(&nullb->lock);  in null_insert_page()
952 	return null_lookup_page(nullb, sector, true, ignore_cache);  in null_insert_page()
955 static int null_flush_cache_page(struct nullb *nullb, struct nullb_page *c_page)  in null_flush_cache_page()  argument
965 	t_page = null_insert_page(nullb, idx << PAGE_SECTORS_SHIFT, true);  in null_flush_cache_page()
971 			ret = radix_tree_delete_item(&nullb->dev->data,  in null_flush_cache_page()
985 			i += (nullb->dev->blocksize >> SECTOR_SHIFT)) {  in null_flush_cache_page()
989 				nullb->dev->blocksize);  in null_flush_cache_page()
997 	ret = radix_tree_delete_item(&nullb->dev->cache, idx, c_page);  in null_flush_cache_page()
999 	nullb->dev->curr_cache -= PAGE_SIZE;  in null_flush_cache_page()
1004 static int null_make_cache_space(struct nullb *nullb, unsigned long n)  in null_make_cache_space()  argument
1011 	if ((nullb->dev->cache_size * 1024 * 1024) >  in null_make_cache_space()
1012 	     nullb->dev->curr_cache + n || nullb->dev->curr_cache == 0)  in null_make_cache_space()
1015 	nr_pages = radix_tree_gang_lookup(&nullb->dev->cache,  in null_make_cache_space()
1016 			(void **)c_pages, nullb->cache_flush_pos, FREE_BATCH);  in null_make_cache_space()
1022 		nullb->cache_flush_pos = c_pages[i]->page->index;  in null_make_cache_space()
1037 		err = null_flush_cache_page(nullb, c_pages[i]);  in null_make_cache_space()
1046 			nullb->cache_flush_pos = 0;  in null_make_cache_space()
1049 			spin_unlock_irq(&nullb->lock);  in null_make_cache_space()
1050 			spin_lock_irq(&nullb->lock);  in null_make_cache_space()
1057 static int copy_to_nullb(struct nullb *nullb, struct page *source,  in copy_to_nullb()  argument
1066 		temp = min_t(size_t, nullb->dev->blocksize, n - count);  in copy_to_nullb()
1068 		if (null_cache_active(nullb) && !is_fua)  in copy_to_nullb()
1069 			null_make_cache_space(nullb, PAGE_SIZE);  in copy_to_nullb()
1072 		t_page = null_insert_page(nullb, sector,  in copy_to_nullb()
1073 			!null_cache_active(nullb) || is_fua);  in copy_to_nullb()
1086 			null_free_sector(nullb, sector, true);  in copy_to_nullb()
1094 static int copy_from_nullb(struct nullb *nullb, struct page *dest,  in copy_from_nullb()  argument
1103 		temp = min_t(size_t, nullb->dev->blocksize, n - count);  in copy_from_nullb()
1106 		t_page = null_lookup_page(nullb, sector, false,  in copy_from_nullb()
1107 			!null_cache_active(nullb));  in copy_from_nullb()
1126 static void nullb_fill_pattern(struct nullb *nullb, struct page *page,  in nullb_fill_pattern()  argument
1139 	struct nullb *nullb = dev->nullb;  in null_handle_discard()  local
1143 	spin_lock_irq(&nullb->lock);  in null_handle_discard()
1146 		null_free_sector(nullb, sector, false);  in null_handle_discard()
1147 		if (null_cache_active(nullb))  in null_handle_discard()
1148 			null_free_sector(nullb, sector, true);  in null_handle_discard()
1152 	spin_unlock_irq(&nullb->lock);  in null_handle_discard()
1157 static int null_handle_flush(struct nullb *nullb)  in null_handle_flush()  argument
1161 	if (!null_cache_active(nullb))  in null_handle_flush()
1164 	spin_lock_irq(&nullb->lock);  in null_handle_flush()
1166 		err = null_make_cache_space(nullb,  in null_handle_flush()
1167 			nullb->dev->cache_size * 1024 * 1024);  in null_handle_flush()
1168 		if (err || nullb->dev->curr_cache == 0)  in null_handle_flush()
1172 	WARN_ON(!radix_tree_empty(&nullb->dev->cache));  in null_handle_flush()
1173 	spin_unlock_irq(&nullb->lock);  in null_handle_flush()
1177 static int null_transfer(struct nullb *nullb, struct page *page,  in null_transfer()  argument
1181 	struct nullb_device *dev = nullb->dev;  in null_transfer()
1187 			valid_len = null_zone_valid_read_len(nullb,  in null_transfer()
1191 			err = copy_from_nullb(nullb, page, off,  in null_transfer()
1198 			nullb_fill_pattern(nullb, page, len, off);  in null_transfer()
1202 		err = copy_to_nullb(nullb, page, off, sector, len, is_fua);  in null_transfer()
1211 	struct nullb *nullb = cmd->nq->dev->nullb;  in null_handle_rq()  local
1218 	spin_lock_irq(&nullb->lock);  in null_handle_rq()
1221 		err = null_transfer(nullb, bvec.bv_page, len, bvec.bv_offset,  in null_handle_rq()
1225 			spin_unlock_irq(&nullb->lock);  in null_handle_rq()
1230 	spin_unlock_irq(&nullb->lock);  in null_handle_rq()
1238 	struct nullb *nullb = cmd->nq->dev->nullb;  in null_handle_bio()  local
1245 	spin_lock_irq(&nullb->lock);  in null_handle_bio()
1248 		err = null_transfer(nullb, bvec.bv_page, len, bvec.bv_offset,  in null_handle_bio()
1252 			spin_unlock_irq(&nullb->lock);  in null_handle_bio()
1257 	spin_unlock_irq(&nullb->lock);  in null_handle_bio()
1261 static void null_stop_queue(struct nullb *nullb)  in null_stop_queue()  argument
1263 	struct request_queue *q = nullb->q;  in null_stop_queue()
1265 	if (nullb->dev->queue_mode == NULL_Q_MQ)  in null_stop_queue()
1269 static void null_restart_queue_async(struct nullb *nullb)  in null_restart_queue_async()  argument
1271 	struct request_queue *q = nullb->q;  in null_restart_queue_async()
1273 	if (nullb->dev->queue_mode == NULL_Q_MQ)  in null_restart_queue_async()
1280 	struct nullb *nullb = dev->nullb;  in null_handle_throttled()  local
1284 	if (!hrtimer_active(&nullb->bw_timer))  in null_handle_throttled()
1285 		hrtimer_restart(&nullb->bw_timer);  in null_handle_throttled()
1287 	if (atomic_long_sub_return(blk_rq_bytes(rq), &nullb->cur_bytes) < 0) {  in null_handle_throttled()
1288 		null_stop_queue(nullb);  in null_handle_throttled()
1290 		if (atomic_long_read(&nullb->cur_bytes) > 0)  in null_handle_throttled()
1291 			null_restart_queue_async(nullb);  in null_handle_throttled()
1407 	struct nullb *nullb = dev->nullb;  in null_handle_cmd()  local
1417 		cmd->error = errno_to_blk_status(null_handle_flush(nullb));  in null_handle_cmd()
1437 	struct nullb *nullb = container_of(timer, struct nullb, bw_timer);  in nullb_bwtimer_fn()  local
1439 	unsigned int mbps = nullb->dev->mbps;  in nullb_bwtimer_fn()
1441 	if (atomic_long_read(&nullb->cur_bytes) == mb_per_tick(mbps))  in nullb_bwtimer_fn()
1444 	atomic_long_set(&nullb->cur_bytes, mb_per_tick(mbps));  in nullb_bwtimer_fn()
1445 	null_restart_queue_async(nullb);  in nullb_bwtimer_fn()
1447 	hrtimer_forward_now(&nullb->bw_timer, timer_interval);  in nullb_bwtimer_fn()
1452 static void nullb_setup_bwtimer(struct nullb *nullb)  in nullb_setup_bwtimer()  argument
1456 	hrtimer_init(&nullb->bw_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);  in nullb_setup_bwtimer()
1457 	nullb->bw_timer.function = nullb_bwtimer_fn;  in nullb_setup_bwtimer()
1458 	atomic_long_set(&nullb->cur_bytes, mb_per_tick(nullb->dev->mbps));  in nullb_setup_bwtimer()
1459 	hrtimer_start(&nullb->bw_timer, timer_interval, HRTIMER_MODE_REL);  in nullb_setup_bwtimer()
1462 static struct nullb_queue *nullb_to_queue(struct nullb *nullb)  in nullb_to_queue()  argument
1466 	if (nullb->nr_queues != 1)  in nullb_to_queue()
1467 		index = raw_smp_processor_id() / ((nr_cpu_ids + nullb->nr_queues - 1) / nullb->nr_queues);  in nullb_to_queue()
1469 	return &nullb->queues[index];  in nullb_to_queue()
1476 	struct nullb *nullb = bio->bi_bdev->bd_disk->private_data;  in null_submit_bio()  local
1477 	struct nullb_queue *nq = nullb_to_queue(nullb);  in null_submit_bio()
1502 	struct nullb *nullb = set->driver_data;  in null_map_queues()  local
1507 	if (nullb) {  in null_map_queues()
1508 		struct nullb_device *dev = nullb->dev;  in null_map_queues()
1663 static void cleanup_queues(struct nullb *nullb)  in cleanup_queues()  argument
1667 	for (i = 0; i < nullb->nr_queues; i++)  in cleanup_queues()
1668 		cleanup_queue(&nullb->queues[i]);  in cleanup_queues()
1670 	kfree(nullb->queues);  in cleanup_queues()
1676 	struct nullb *nullb = nq->dev->nullb;  in null_exit_hctx()  local
1678 	nullb->nr_queues--;  in null_exit_hctx()
1681 static void null_init_queue(struct nullb *nullb, struct nullb_queue *nq)  in null_init_queue()  argument
1684 	nq->queue_depth = nullb->queue_depth;  in null_init_queue()
1685 	nq->dev = nullb->dev;  in null_init_queue()
1693 	struct nullb *nullb = hctx->queue->queuedata;  in null_init_hctx()  local
1701 	nq = &nullb->queues[hctx_idx];  in null_init_hctx()
1703 	null_init_queue(nullb, nq);  in null_init_hctx()
1704 	nullb->nr_queues++;  in null_init_hctx()
1719 static void null_del_dev(struct nullb *nullb)  in null_del_dev()  argument
1723 	if (!nullb)  in null_del_dev()
1726 	dev = nullb->dev;  in null_del_dev()
1728 	ida_simple_remove(&nullb_indexes, nullb->index);  in null_del_dev()
1730 	list_del_init(&nullb->list);  in null_del_dev()
1732 	del_gendisk(nullb->disk);  in null_del_dev()
1734 	if (test_bit(NULLB_DEV_FL_THROTTLED, &nullb->dev->flags)) {  in null_del_dev()
1735 		hrtimer_cancel(&nullb->bw_timer);  in null_del_dev()
1736 		atomic_long_set(&nullb->cur_bytes, LONG_MAX);  in null_del_dev()
1737 		null_restart_queue_async(nullb);  in null_del_dev()
1740 	blk_cleanup_disk(nullb->disk);  in null_del_dev()
1742 	    nullb->tag_set == &nullb->__tag_set)  in null_del_dev()
1743 		blk_mq_free_tag_set(nullb->tag_set);  in null_del_dev()
1744 	cleanup_queues(nullb);  in null_del_dev()
1745 	if (null_cache_active(nullb))  in null_del_dev()
1746 		null_free_device_storage(nullb->dev, true);  in null_del_dev()
1747 	kfree(nullb);  in null_del_dev()
1748 	dev->nullb = NULL;  in null_del_dev()
1751 static void null_config_discard(struct nullb *nullb)  in null_config_discard()  argument
1753 	if (nullb->dev->discard == false)  in null_config_discard()
1756 	if (!nullb->dev->memory_backed) {  in null_config_discard()
1757 		nullb->dev->discard = false;  in null_config_discard()
1762 	if (nullb->dev->zoned) {  in null_config_discard()
1763 		nullb->dev->discard = false;  in null_config_discard()
1768 	nullb->q->limits.discard_granularity = nullb->dev->blocksize;  in null_config_discard()
1769 	blk_queue_max_discard_sectors(nullb->q, UINT_MAX >> 9);  in null_config_discard()
1807 static int setup_queues(struct nullb *nullb)  in setup_queues()  argument
1814 	nullb->queues = kcalloc(nqueues, sizeof(struct nullb_queue),  in setup_queues()
1816 	if (!nullb->queues)  in setup_queues()
1819 	nullb->queue_depth = nullb->dev->hw_queue_depth;  in setup_queues()
1823 static int init_driver_queues(struct nullb *nullb)  in init_driver_queues()  argument
1828 	for (i = 0; i < nullb->dev->submit_queues; i++) {  in init_driver_queues()
1829 		nq = &nullb->queues[i];  in init_driver_queues()
1831 		null_init_queue(nullb, nq);  in init_driver_queues()
1836 		nullb->nr_queues++;  in init_driver_queues()
1841 static int null_gendisk_register(struct nullb *nullb)  in null_gendisk_register()  argument
1843 	sector_t size = ((sector_t)nullb->dev->size * SZ_1M) >> SECTOR_SHIFT;  in null_gendisk_register()
1844 	struct gendisk *disk = nullb->disk;  in null_gendisk_register()
1849 	disk->first_minor	= nullb->index;  in null_gendisk_register()
1851 	if (queue_is_mq(nullb->q))  in null_gendisk_register()
1855 	disk->private_data	= nullb;  in null_gendisk_register()
1856 	strncpy(disk->disk_name, nullb->disk_name, DISK_NAME_LEN);  in null_gendisk_register()
1858 	if (nullb->dev->zoned) {  in null_gendisk_register()
1859 		int ret = null_register_zoned_dev(nullb);  in null_gendisk_register()
1868 static int null_init_tag_set(struct nullb *nullb, struct blk_mq_tag_set *set)  in null_init_tag_set()  argument
1873 	set->nr_hw_queues = nullb ? nullb->dev->submit_queues :  in null_init_tag_set()
1875 	poll_queues = nullb ? nullb->dev->poll_queues : g_poll_queues;  in null_init_tag_set()
1878 	set->queue_depth = nullb ? nullb->dev->hw_queue_depth :  in null_init_tag_set()
1880 	set->numa_node = nullb ? nullb->dev->home_node : g_home_node;  in null_init_tag_set()
1887 	set->driver_data = nullb;  in null_init_tag_set()
1893 	if ((nullb && nullb->dev->blocking) || g_blocking)  in null_init_tag_set()
1970 	struct nullb *nullb;  in null_add_dev()  local
1977 	nullb = kzalloc_node(sizeof(*nullb), GFP_KERNEL, dev->home_node);  in null_add_dev()
1978 	if (!nullb) {  in null_add_dev()
1982 	nullb->dev = dev;  in null_add_dev()
1983 	dev->nullb = nullb;  in null_add_dev()
1985 	spin_lock_init(&nullb->lock);  in null_add_dev()
1987 	rv = setup_queues(nullb);  in null_add_dev()
1993 			nullb->tag_set = &tag_set;  in null_add_dev()
1996 			nullb->tag_set = &nullb->__tag_set;  in null_add_dev()
1997 			rv = null_init_tag_set(nullb, nullb->tag_set);  in null_add_dev()
2006 		nullb->tag_set->timeout = 5 * HZ;  in null_add_dev()
2007 		nullb->disk = blk_mq_alloc_disk(nullb->tag_set, nullb);  in null_add_dev()
2008 		if (IS_ERR(nullb->disk)) {  in null_add_dev()
2009 			rv = PTR_ERR(nullb->disk);  in null_add_dev()
2012 		nullb->q = nullb->disk->queue;  in null_add_dev()
2015 		nullb->disk = blk_alloc_disk(nullb->dev->home_node);  in null_add_dev()
2016 		if (!nullb->disk)  in null_add_dev()
2019 		nullb->q = nullb->disk->queue;  in null_add_dev()
2020 		rv = init_driver_queues(nullb);  in null_add_dev()
2027 		nullb_setup_bwtimer(nullb);  in null_add_dev()
2031 		set_bit(NULLB_DEV_FL_CACHE, &nullb->dev->flags);  in null_add_dev()
2032 		blk_queue_write_cache(nullb->q, true, true);  in null_add_dev()
2036 		rv = null_init_zoned_dev(dev, nullb->q);  in null_add_dev()
2041 	nullb->q->queuedata = nullb;  in null_add_dev()
2042 	blk_queue_flag_set(QUEUE_FLAG_NONROT, nullb->q);  in null_add_dev()
2043 	blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, nullb->q);  in null_add_dev()
2051 	nullb->index = rv;  in null_add_dev()
2055 	blk_queue_logical_block_size(nullb->q, dev->blocksize);  in null_add_dev()
2056 	blk_queue_physical_block_size(nullb->q, dev->blocksize);  in null_add_dev()
2058 		dev->max_sectors = queue_max_hw_sectors(nullb->q);  in null_add_dev()
2061 	blk_queue_max_hw_sectors(nullb->q, dev->max_sectors);  in null_add_dev()
2064 		blk_queue_virt_boundary(nullb->q, PAGE_SIZE - 1);  in null_add_dev()
2066 	null_config_discard(nullb);  in null_add_dev()
2070 		snprintf(nullb->disk_name, sizeof(nullb->disk_name),  in null_add_dev()
2073 		sprintf(nullb->disk_name, "nullb%d", nullb->index);  in null_add_dev()
2076 	rv = null_gendisk_register(nullb);  in null_add_dev()
2081 	list_add_tail(&nullb->list, &nullb_list);  in null_add_dev()
2084 	pr_info("disk %s created\n", nullb->disk_name);  in null_add_dev()
2089 	ida_free(&nullb_indexes, nullb->index);  in null_add_dev()
2093 	blk_cleanup_disk(nullb->disk);  in null_add_dev()
2095 	if (dev->queue_mode == NULL_Q_MQ && nullb->tag_set == &nullb->__tag_set)  in null_add_dev()
2096 		blk_mq_free_tag_set(nullb->tag_set);  in null_add_dev()
2098 	cleanup_queues(nullb);  in null_add_dev()
2100 	kfree(nullb);  in null_add_dev()
2101 	dev->nullb = NULL;  in null_add_dev()
2106 static struct nullb *null_find_dev_by_name(const char *name)  in null_find_dev_by_name()
2108 	struct nullb *nullb = NULL, *nb;  in null_find_dev_by_name()  local
2113 			nullb = nb;  in null_find_dev_by_name()
2119 	return nullb;  in null_find_dev_by_name()
2140 static void null_destroy_dev(struct nullb *nullb)  in null_destroy_dev()  argument
2142 	struct nullb_device *dev = nullb->dev;  in null_destroy_dev()
2144 	null_del_dev(nullb);  in null_destroy_dev()
2152 	struct nullb *nullb;  in null_init()  local
2220 		nullb = list_entry(nullb_list.next, struct nullb, list);  in null_init()
2221 		null_destroy_dev(nullb);  in null_init()
2234 	struct nullb *nullb;  in null_exit()  local
2242 		nullb = list_entry(nullb_list.next, struct nullb, list);  in null_exit()
2243 		null_destroy_dev(nullb);  in null_exit()