| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Shaohua Li | 4590 | 41.73% | 9 | 6.16% |
| Jens Axboe | 2682 | 24.38% | 17 | 11.64% |
| Matias Björling | 614 | 5.58% | 13 | 8.90% |
| Damien Le Moal | 576 | 5.24% | 11 | 7.53% |
| Bart Van Assche | 434 | 3.95% | 11 | 7.53% |
| Chaitanya Kulkarni | 423 | 3.85% | 12 | 8.22% |
| Shin'ichiro Kawasaki | 346 | 3.15% | 2 | 1.37% |
| Christoph Hellwig | 248 | 2.25% | 20 | 13.70% |
| Vincent Fu | 246 | 2.24% | 2 | 1.37% |
| Ajay Joshi | 101 | 0.92% | 1 | 0.68% |
| Ming Lei | 87 | 0.79% | 7 | 4.79% |
| Max Gurtovoy | 83 | 0.75% | 2 | 1.37% |
| Niklas Svensson (Niklas Cassel) | 64 | 0.58% | 1 | 0.68% |
| Paolo Valente | 44 | 0.40% | 1 | 0.68% |
| Dan Carpenter | 37 | 0.34% | 1 | 0.68% |
| Arianna Avanzini | 35 | 0.32% | 2 | 1.37% |
| Aravind Ramesh | 32 | 0.29% | 1 | 0.68% |
| Masato Suzuki | 30 | 0.27% | 1 | 0.68% |
| Minfei Huang | 29 | 0.26% | 1 | 0.68% |
| weiping zhang | 29 | 0.26% | 3 | 2.05% |
| Joe Perches | 28 | 0.25% | 1 | 0.68% |
| Dongli Zhang | 26 | 0.24% | 1 | 0.68% |
| Arnd Bergmann | 26 | 0.24% | 1 | 0.68% |
| Robert Elliott | 26 | 0.24% | 1 | 0.68% |
| John Garry | 21 | 0.19% | 1 | 0.68% |
| Raghavendra K T | 20 | 0.18% | 1 | 0.68% |
| John Pittman | 20 | 0.18% | 1 | 0.68% |
| Bob Liu | 14 | 0.13% | 1 | 0.68% |
| David Disseldorp | 14 | 0.13% | 1 | 0.68% |
| Alexey Dobriyan | 12 | 0.11% | 1 | 0.68% |
| Jan Kara | 11 | 0.10% | 1 | 0.68% |
| Mike Snitzer | 10 | 0.09% | 2 | 1.37% |
| Liu Bo | 10 | 0.09% | 1 | 0.68% |
| André Almeida | 9 | 0.08% | 3 | 2.05% |
| Christophe Jaillet | 5 | 0.05% | 1 | 0.68% |
| Kees Cook | 4 | 0.04% | 1 | 0.68% |
| Luis R. Rodriguez | 3 | 0.03% | 2 | 1.37% |
| Wei Yongjun | 2 | 0.02% | 1 | 0.68% |
| Bhumika Goyal | 2 | 0.02% | 1 | 0.68% |
| Heinz Mauelshagen | 2 | 0.02% | 1 | 0.68% |
| Hou Pu | 2 | 0.02% | 1 | 0.68% |
| Thomas Gleixner | 1 | 0.01% | 1 | 0.68% |
| Eric Biggers | 1 | 0.01% | 1 | 0.68% |
| Colin Ian King | 1 | 0.01% | 1 | 0.68% |
| Total | 11000 | 146 |
// SPDX-License-Identifier: GPL-2.0-only /* * Add configfs and memory store: Kyungchan Koh <kkc6196@fb.com> and * Shaohua Li <shli@fb.com> */ #include <linux/module.h> #include <linux/moduleparam.h> #include <linux/sched.h> #include <linux/fs.h> #include <linux/init.h> #include "null_blk.h" #undef pr_fmt #define pr_fmt(fmt) "null_blk: " fmt #define FREE_BATCH 16 #define TICKS_PER_SEC 50ULL #define TIMER_INTERVAL (NSEC_PER_SEC / TICKS_PER_SEC) #ifdef CONFIG_BLK_DEV_NULL_BLK_FAULT_INJECTION static DECLARE_FAULT_ATTR(null_timeout_attr); static DECLARE_FAULT_ATTR(null_requeue_attr); static DECLARE_FAULT_ATTR(null_init_hctx_attr); #endif static inline u64 mb_per_tick(int mbps) { return (1 << 20) / TICKS_PER_SEC * ((u64) mbps); } /* * Status flags for nullb_device. * * CONFIGURED: Device has been configured and turned on. Cannot reconfigure. * UP: Device is currently on and visible in userspace. * THROTTLED: Device is being throttled. * CACHE: Device is using a write-back cache. */ enum nullb_device_flags { NULLB_DEV_FL_CONFIGURED = 0, NULLB_DEV_FL_UP = 1, NULLB_DEV_FL_THROTTLED = 2, NULLB_DEV_FL_CACHE = 3, }; #define MAP_SZ ((PAGE_SIZE >> SECTOR_SHIFT) + 2) /* * nullb_page is a page in memory for nullb devices. * * @page: The page holding the data. * @bitmap: The bitmap represents which sector in the page has data. * Each bit represents one block size. For example, sector 8 * will use the 7th bit * The highest 2 bits of bitmap are for special purpose. LOCK means the cache * page is being flushing to storage. FREE means the cache page is freed and * should be skipped from flushing to storage. Please see * null_make_cache_space */ struct nullb_page { struct page *page; DECLARE_BITMAP(bitmap, MAP_SZ); }; #define NULLB_PAGE_LOCK (MAP_SZ - 1) #define NULLB_PAGE_FREE (MAP_SZ - 2) static LIST_HEAD(nullb_list); static struct mutex lock; static int null_major; static DEFINE_IDA(nullb_indexes); static struct blk_mq_tag_set tag_set; enum { NULL_IRQ_NONE = 0, NULL_IRQ_SOFTIRQ = 1, NULL_IRQ_TIMER = 2, }; static bool g_virt_boundary = false; module_param_named(virt_boundary, g_virt_boundary, bool, 0444); MODULE_PARM_DESC(virt_boundary, "Require a virtual boundary for the device. Default: False"); static int g_no_sched; module_param_named(no_sched, g_no_sched, int, 0444); MODULE_PARM_DESC(no_sched, "No io scheduler"); static int g_submit_queues = 1; module_param_named(submit_queues, g_submit_queues, int, 0444); MODULE_PARM_DESC(submit_queues, "Number of submission queues"); static int g_poll_queues = 1; module_param_named(poll_queues, g_poll_queues, int, 0444); MODULE_PARM_DESC(poll_queues, "Number of IOPOLL submission queues"); static int g_home_node = NUMA_NO_NODE; module_param_named(home_node, g_home_node, int, 0444); MODULE_PARM_DESC(home_node, "Home node for the device"); #ifdef CONFIG_BLK_DEV_NULL_BLK_FAULT_INJECTION /* * For more details about fault injection, please refer to * Documentation/fault-injection/fault-injection.rst. */ static char g_timeout_str[80]; module_param_string(timeout, g_timeout_str, sizeof(g_timeout_str), 0444); MODULE_PARM_DESC(timeout, "Fault injection. timeout=<interval>,<probability>,<space>,<times>"); static char g_requeue_str[80]; module_param_string(requeue, g_requeue_str, sizeof(g_requeue_str), 0444); MODULE_PARM_DESC(requeue, "Fault injection. requeue=<interval>,<probability>,<space>,<times>"); static char g_init_hctx_str[80]; module_param_string(init_hctx, g_init_hctx_str, sizeof(g_init_hctx_str), 0444); MODULE_PARM_DESC(init_hctx, "Fault injection to fail hctx init. init_hctx=<interval>,<probability>,<space>,<times>"); #endif static int g_queue_mode = NULL_Q_MQ; static int null_param_store_val(const char *str, int *val, int min, int max) { int ret, new_val; ret = kstrtoint(str, 10, &new_val); if (ret) return -EINVAL; if (new_val < min || new_val > max) return -EINVAL; *val = new_val; return 0; } static int null_set_queue_mode(const char *str, const struct kernel_param *kp) { return null_param_store_val(str, &g_queue_mode, NULL_Q_BIO, NULL_Q_MQ); } static const struct kernel_param_ops null_queue_mode_param_ops = { .set = null_set_queue_mode, .get = param_get_int, }; device_param_cb(queue_mode, &null_queue_mode_param_ops, &g_queue_mode, 0444); MODULE_PARM_DESC(queue_mode, "Block interface to use (0=bio,1=rq,2=multiqueue)"); static int g_gb = 250; module_param_named(gb, g_gb, int, 0444); MODULE_PARM_DESC(gb, "Size in GB"); static int g_bs = 512; module_param_named(bs, g_bs, int, 0444); MODULE_PARM_DESC(bs, "Block size (in bytes)"); static int g_max_sectors; module_param_named(max_sectors, g_max_sectors, int, 0444); MODULE_PARM_DESC(max_sectors, "Maximum size of a command (in 512B sectors)"); static unsigned int nr_devices = 1; module_param(nr_devices, uint, 0444); MODULE_PARM_DESC(nr_devices, "Number of devices to register"); static bool g_blocking; module_param_named(blocking, g_blocking, bool, 0444); MODULE_PARM_DESC(blocking, "Register as a blocking blk-mq driver device"); static bool shared_tags; module_param(shared_tags, bool, 0444); MODULE_PARM_DESC(shared_tags, "Share tag set between devices for blk-mq"); static bool g_shared_tag_bitmap; module_param_named(shared_tag_bitmap, g_shared_tag_bitmap, bool, 0444); MODULE_PARM_DESC(shared_tag_bitmap, "Use shared tag bitmap for all submission queues for blk-mq"); static int g_irqmode = NULL_IRQ_SOFTIRQ; static int null_set_irqmode(const char *str, const struct kernel_param *kp) { return null_param_store_val(str, &g_irqmode, NULL_IRQ_NONE, NULL_IRQ_TIMER); } static const struct kernel_param_ops null_irqmode_param_ops = { .set = null_set_irqmode, .get = param_get_int, }; device_param_cb(irqmode, &null_irqmode_param_ops, &g_irqmode, 0444); MODULE_PARM_DESC(irqmode, "IRQ completion handler. 0-none, 1-softirq, 2-timer"); static unsigned long g_completion_nsec = 10000; module_param_named(completion_nsec, g_completion_nsec, ulong, 0444); MODULE_PARM_DESC(completion_nsec, "Time in ns to complete a request in hardware. Default: 10,000ns"); static int g_hw_queue_depth = 64; module_param_named(hw_queue_depth, g_hw_queue_depth, int, 0444); MODULE_PARM_DESC(hw_queue_depth, "Queue depth for each hardware queue. Default: 64"); static bool g_use_per_node_hctx; module_param_named(use_per_node_hctx, g_use_per_node_hctx, bool, 0444); MODULE_PARM_DESC(use_per_node_hctx, "Use per-node allocation for hardware context queues. Default: false"); static bool g_memory_backed; module_param_named(memory_backed, g_memory_backed, bool, 0444); MODULE_PARM_DESC(memory_backed, "Create a memory-backed block device. Default: false"); static bool g_discard; module_param_named(discard, g_discard, bool, 0444); MODULE_PARM_DESC(discard, "Support discard operations (requires memory-backed null_blk device). Default: false"); static unsigned long g_cache_size; module_param_named(cache_size, g_cache_size, ulong, 0444); MODULE_PARM_DESC(mbps, "Cache size in MiB for memory-backed device. Default: 0 (none)"); static unsigned int g_mbps; module_param_named(mbps, g_mbps, uint, 0444); MODULE_PARM_DESC(mbps, "Limit maximum bandwidth (in MiB/s). Default: 0 (no limit)"); static bool g_zoned; module_param_named(zoned, g_zoned, bool, S_IRUGO); MODULE_PARM_DESC(zoned, "Make device as a host-managed zoned block device. Default: false"); static unsigned long g_zone_size = 256; module_param_named(zone_size, g_zone_size, ulong, S_IRUGO); MODULE_PARM_DESC(zone_size, "Zone size in MB when block device is zoned. Must be power-of-two: Default: 256"); static unsigned long g_zone_capacity; module_param_named(zone_capacity, g_zone_capacity, ulong, 0444); MODULE_PARM_DESC(zone_capacity, "Zone capacity in MB when block device is zoned. Can be less than or equal to zone size. Default: Zone size"); static unsigned int g_zone_nr_conv; module_param_named(zone_nr_conv, g_zone_nr_conv, uint, 0444); MODULE_PARM_DESC(zone_nr_conv, "Number of conventional zones when block device is zoned. Default: 0"); static unsigned int g_zone_max_open; module_param_named(zone_max_open, g_zone_max_open, uint, 0444); MODULE_PARM_DESC(zone_max_open, "Maximum number of open zones when block device is zoned. Default: 0 (no limit)"); static unsigned int g_zone_max_active; module_param_named(zone_max_active, g_zone_max_active, uint, 0444); MODULE_PARM_DESC(zone_max_active, "Maximum number of active zones when block device is zoned. Default: 0 (no limit)"); static struct nullb_device *null_alloc_dev(void); static void null_free_dev(struct nullb_device *dev); static void null_del_dev(struct nullb *nullb); static int null_add_dev(struct nullb_device *dev); static struct nullb *null_find_dev_by_name(const char *name); static void null_free_device_storage(struct nullb_device *dev, bool is_cache); static inline struct nullb_device *to_nullb_device(struct config_item *item) { return item ? container_of(item, struct nullb_device, item) : NULL; } static inline ssize_t nullb_device_uint_attr_show(unsigned int val, char *page) { return snprintf(page, PAGE_SIZE, "%u\n", val); } static inline ssize_t nullb_device_ulong_attr_show(unsigned long val, char *page) { return snprintf(page, PAGE_SIZE, "%lu\n", val); } static inline ssize_t nullb_device_bool_attr_show(bool val, char *page) { return snprintf(page, PAGE_SIZE, "%u\n", val); } static ssize_t nullb_device_uint_attr_store(unsigned int *val, const char *page, size_t count) { unsigned int tmp; int result; result = kstrtouint(page, 0, &tmp); if (result < 0) return result; *val = tmp; return count; } static ssize_t nullb_device_ulong_attr_store(unsigned long *val, const char *page, size_t count) { int result; unsigned long tmp; result = kstrtoul(page, 0, &tmp); if (result < 0) return result; *val = tmp; return count; } static ssize_t nullb_device_bool_attr_store(bool *val, const char *page, size_t count) { bool tmp; int result; result = kstrtobool(page, &tmp); if (result < 0) return result; *val = tmp; return count; } /* The following macro should only be used with TYPE = {uint, ulong, bool}. */ #define NULLB_DEVICE_ATTR(NAME, TYPE, APPLY) \ static ssize_t \ nullb_device_##NAME##_show(struct config_item *item, char *page) \ { \ return nullb_device_##TYPE##_attr_show( \ to_nullb_device(item)->NAME, page); \ } \ static ssize_t \ nullb_device_##NAME##_store(struct config_item *item, const char *page, \ size_t count) \ { \ int (*apply_fn)(struct nullb_device *dev, TYPE new_value) = APPLY;\ struct nullb_device *dev = to_nullb_device(item); \ TYPE new_value = 0; \ int ret; \ \ ret = nullb_device_##TYPE##_attr_store(&new_value, page, count);\ if (ret < 0) \ return ret; \ if (apply_fn) \ ret = apply_fn(dev, new_value); \ else if (test_bit(NULLB_DEV_FL_CONFIGURED, &dev->flags)) \ ret = -EBUSY; \ if (ret < 0) \ return ret; \ dev->NAME = new_value; \ return count; \ } \ CONFIGFS_ATTR(nullb_device_, NAME); static int nullb_update_nr_hw_queues(struct nullb_device *dev, unsigned int submit_queues, unsigned int poll_queues) { struct blk_mq_tag_set *set; int ret, nr_hw_queues; if (!dev->nullb) return 0; /* * Make sure at least one submit queue exists. */ if (!submit_queues) return -EINVAL; /* * Make sure that null_init_hctx() does not access nullb->queues[] past * the end of that array. */ if (submit_queues > nr_cpu_ids || poll_queues > g_poll_queues) return -EINVAL; /* * Keep previous and new queue numbers in nullb_device for reference in * the call back function null_map_queues(). */ dev->prev_submit_queues = dev->submit_queues; dev->prev_poll_queues = dev->poll_queues; dev->submit_queues = submit_queues; dev->poll_queues = poll_queues; set = dev->nullb->tag_set; nr_hw_queues = submit_queues + poll_queues; blk_mq_update_nr_hw_queues(set, nr_hw_queues); ret = set->nr_hw_queues == nr_hw_queues ? 0 : -ENOMEM; if (ret) { /* on error, revert the queue numbers */ dev->submit_queues = dev->prev_submit_queues; dev->poll_queues = dev->prev_poll_queues; } return ret; } static int nullb_apply_submit_queues(struct nullb_device *dev, unsigned int submit_queues) { return nullb_update_nr_hw_queues(dev, submit_queues, dev->poll_queues); } static int nullb_apply_poll_queues(struct nullb_device *dev, unsigned int poll_queues) { return nullb_update_nr_hw_queues(dev, dev->submit_queues, poll_queues); } NULLB_DEVICE_ATTR(size, ulong, NULL); NULLB_DEVICE_ATTR(completion_nsec, ulong, NULL); NULLB_DEVICE_ATTR(submit_queues, uint, nullb_apply_submit_queues); NULLB_DEVICE_ATTR(poll_queues, uint, nullb_apply_poll_queues); NULLB_DEVICE_ATTR(home_node, uint, NULL); NULLB_DEVICE_ATTR(queue_mode, uint, NULL); NULLB_DEVICE_ATTR(blocksize, uint, NULL); NULLB_DEVICE_ATTR(max_sectors, uint, NULL); NULLB_DEVICE_ATTR(irqmode, uint, NULL); NULLB_DEVICE_ATTR(hw_queue_depth, uint, NULL); NULLB_DEVICE_ATTR(index, uint, NULL); NULLB_DEVICE_ATTR(blocking, bool, NULL); NULLB_DEVICE_ATTR(use_per_node_hctx, bool, NULL); NULLB_DEVICE_ATTR(memory_backed, bool, NULL); NULLB_DEVICE_ATTR(discard, bool, NULL); NULLB_DEVICE_ATTR(mbps, uint, NULL); NULLB_DEVICE_ATTR(cache_size, ulong, NULL); NULLB_DEVICE_ATTR(zoned, bool, NULL); NULLB_DEVICE_ATTR(zone_size, ulong, NULL); NULLB_DEVICE_ATTR(zone_capacity, ulong, NULL); NULLB_DEVICE_ATTR(zone_nr_conv, uint, NULL); NULLB_DEVICE_ATTR(zone_max_open, uint, NULL); NULLB_DEVICE_ATTR(zone_max_active, uint, NULL); NULLB_DEVICE_ATTR(virt_boundary, bool, NULL); NULLB_DEVICE_ATTR(no_sched, bool, NULL); NULLB_DEVICE_ATTR(shared_tag_bitmap, bool, NULL); static ssize_t nullb_device_power_show(struct config_item *item, char *page) { return nullb_device_bool_attr_show(to_nullb_device(item)->power, page); } static ssize_t nullb_device_power_store(struct config_item *item, const char *page, size_t count) { struct nullb_device *dev = to_nullb_device(item); bool newp = false; ssize_t ret; ret = nullb_device_bool_attr_store(&newp, page, count); if (ret < 0) return ret; if (!dev->power && newp) { if (test_and_set_bit(NULLB_DEV_FL_UP, &dev->flags)) return count; ret = null_add_dev(dev); if (ret) { clear_bit(NULLB_DEV_FL_UP, &dev->flags); return ret; } set_bit(NULLB_DEV_FL_CONFIGURED, &dev->flags); dev->power = newp; } else if (dev->power && !newp) { if (test_and_clear_bit(NULLB_DEV_FL_UP, &dev->flags)) { mutex_lock(&lock); dev->power = newp; null_del_dev(dev->nullb); mutex_unlock(&lock); } clear_bit(NULLB_DEV_FL_CONFIGURED, &dev->flags); } return count; } CONFIGFS_ATTR(nullb_device_, power); static ssize_t nullb_device_badblocks_show(struct config_item *item, char *page) { struct nullb_device *t_dev = to_nullb_device(item); return badblocks_show(&t_dev->badblocks, page, 0); } static ssize_t nullb_device_badblocks_store(struct config_item *item, const char *page, size_t count) { struct nullb_device *t_dev = to_nullb_device(item); char *orig, *buf, *tmp; u64 start, end; int ret; orig = kstrndup(page, count, GFP_KERNEL); if (!orig) return -ENOMEM; buf = strstrip(orig); ret = -EINVAL; if (buf[0] != '+' && buf[0] != '-') goto out; tmp = strchr(&buf[1], '-'); if (!tmp) goto out; *tmp = '\0'; ret = kstrtoull(buf + 1, 0, &start); if (ret) goto out; ret = kstrtoull(tmp + 1, 0, &end); if (ret) goto out; ret = -EINVAL; if (start > end) goto out; /* enable badblocks */ cmpxchg(&t_dev->badblocks.shift, -1, 0); if (buf[0] == '+') ret = badblocks_set(&t_dev->badblocks, start, end - start + 1, 1); else ret = badblocks_clear(&t_dev->badblocks, start, end - start + 1); if (ret == 0) ret = count; out: kfree(orig); return ret; } CONFIGFS_ATTR(nullb_device_, badblocks); static ssize_t nullb_device_zone_readonly_store(struct config_item *item, const char *page, size_t count) { struct nullb_device *dev = to_nullb_device(item); return zone_cond_store(dev, page, count, BLK_ZONE_COND_READONLY); } CONFIGFS_ATTR_WO(nullb_device_, zone_readonly); static ssize_t nullb_device_zone_offline_store(struct config_item *item, const char *page, size_t count) { struct nullb_device *dev = to_nullb_device(item); return zone_cond_store(dev, page, count, BLK_ZONE_COND_OFFLINE); } CONFIGFS_ATTR_WO(nullb_device_, zone_offline); static struct configfs_attribute *nullb_device_attrs[] = { &nullb_device_attr_size, &nullb_device_attr_completion_nsec, &nullb_device_attr_submit_queues, &nullb_device_attr_poll_queues, &nullb_device_attr_home_node, &nullb_device_attr_queue_mode, &nullb_device_attr_blocksize, &nullb_device_attr_max_sectors, &nullb_device_attr_irqmode, &nullb_device_attr_hw_queue_depth, &nullb_device_attr_index, &nullb_device_attr_blocking, &nullb_device_attr_use_per_node_hctx, &nullb_device_attr_power, &nullb_device_attr_memory_backed, &nullb_device_attr_discard, &nullb_device_attr_mbps, &nullb_device_attr_cache_size, &nullb_device_attr_badblocks, &nullb_device_attr_zoned, &nullb_device_attr_zone_size, &nullb_device_attr_zone_capacity, &nullb_device_attr_zone_nr_conv, &nullb_device_attr_zone_max_open, &nullb_device_attr_zone_max_active, &nullb_device_attr_zone_readonly, &nullb_device_attr_zone_offline, &nullb_device_attr_virt_boundary, &nullb_device_attr_no_sched, &nullb_device_attr_shared_tag_bitmap, NULL, }; static void nullb_device_release(struct config_item *item) { struct nullb_device *dev = to_nullb_device(item); null_free_device_storage(dev, false); null_free_dev(dev); } static struct configfs_item_operations nullb_device_ops = { .release = nullb_device_release, }; static const struct config_item_type nullb_device_type = { .ct_item_ops = &nullb_device_ops, .ct_attrs = nullb_device_attrs, .ct_owner = THIS_MODULE, }; static struct config_item *nullb_group_make_item(struct config_group *group, const char *name) { struct nullb_device *dev; if (null_find_dev_by_name(name)) return ERR_PTR(-EEXIST); dev = null_alloc_dev(); if (!dev) return ERR_PTR(-ENOMEM); config_item_init_type_name(&dev->item, name, &nullb_device_type); return &dev->item; } static void nullb_group_drop_item(struct config_group *group, struct config_item *item) { struct nullb_device *dev = to_nullb_device(item); if (test_and_clear_bit(NULLB_DEV_FL_UP, &dev->flags)) { mutex_lock(&lock); dev->power = false; null_del_dev(dev->nullb); mutex_unlock(&lock); } config_item_put(item); } static ssize_t memb_group_features_show(struct config_item *item, char *page) { return snprintf(page, PAGE_SIZE, "badblocks,blocking,blocksize,cache_size," "completion_nsec,discard,home_node,hw_queue_depth," "irqmode,max_sectors,mbps,memory_backed,no_sched," "poll_queues,power,queue_mode,shared_tag_bitmap,size," "submit_queues,use_per_node_hctx,virt_boundary,zoned," "zone_capacity,zone_max_active,zone_max_open," "zone_nr_conv,zone_offline,zone_readonly,zone_size\n"); } CONFIGFS_ATTR_RO(memb_group_, features); static struct configfs_attribute *nullb_group_attrs[] = { &memb_group_attr_features, NULL, }; static struct configfs_group_operations nullb_group_ops = { .make_item = nullb_group_make_item, .drop_item = nullb_group_drop_item, }; static const struct config_item_type nullb_group_type = { .ct_group_ops = &nullb_group_ops, .ct_attrs = nullb_group_attrs, .ct_owner = THIS_MODULE, }; static struct configfs_subsystem nullb_subsys = { .su_group = { .cg_item = { .ci_namebuf = "nullb", .ci_type = &nullb_group_type, }, }, }; static inline int null_cache_active(struct nullb *nullb) { return test_bit(NULLB_DEV_FL_CACHE, &nullb->dev->flags); } static struct nullb_device *null_alloc_dev(void) { struct nullb_device *dev; dev = kzalloc(sizeof(*dev), GFP_KERNEL); if (!dev) return NULL; INIT_RADIX_TREE(&dev->data, GFP_ATOMIC); INIT_RADIX_TREE(&dev->cache, GFP_ATOMIC); if (badblocks_init(&dev->badblocks, 0)) { kfree(dev); return NULL; } dev->size = g_gb * 1024; dev->completion_nsec = g_completion_nsec; dev->submit_queues = g_submit_queues; dev->prev_submit_queues = g_submit_queues; dev->poll_queues = g_poll_queues; dev->prev_poll_queues = g_poll_queues; dev->home_node = g_home_node; dev->queue_mode = g_queue_mode; dev->blocksize = g_bs; dev->max_sectors = g_max_sectors; dev->irqmode = g_irqmode; dev->hw_queue_depth = g_hw_queue_depth; dev->blocking = g_blocking; dev->memory_backed = g_memory_backed; dev->discard = g_discard; dev->cache_size = g_cache_size; dev->mbps = g_mbps; dev->use_per_node_hctx = g_use_per_node_hctx; dev->zoned = g_zoned; dev->zone_size = g_zone_size; dev->zone_capacity = g_zone_capacity; dev->zone_nr_conv = g_zone_nr_conv; dev->zone_max_open = g_zone_max_open; dev->zone_max_active = g_zone_max_active; dev->virt_boundary = g_virt_boundary; dev->no_sched = g_no_sched; dev->shared_tag_bitmap = g_shared_tag_bitmap; return dev; } static void null_free_dev(struct nullb_device *dev) { if (!dev) return; null_free_zoned_dev(dev); badblocks_exit(&dev->badblocks); kfree(dev); } static void put_tag(struct nullb_queue *nq, unsigned int tag) { clear_bit_unlock(tag, nq->tag_map); if (waitqueue_active(&nq->wait)) wake_up(&nq->wait); } static unsigned int get_tag(struct nullb_queue *nq) { unsigned int tag; do { tag = find_first_zero_bit(nq->tag_map, nq->queue_depth); if (tag >= nq->queue_depth) return -1U; } while (test_and_set_bit_lock(tag, nq->tag_map)); return tag; } static void free_cmd(struct nullb_cmd *cmd) { put_tag(cmd->nq, cmd->tag); } static enum hrtimer_restart null_cmd_timer_expired(struct hrtimer *timer); static struct nullb_cmd *__alloc_cmd(struct nullb_queue *nq) { struct nullb_cmd *cmd; unsigned int tag; tag = get_tag(nq); if (tag != -1U) { cmd = &nq->cmds[tag]; cmd->tag = tag; cmd->error = BLK_STS_OK; cmd->nq = nq; if (nq->dev->irqmode == NULL_IRQ_TIMER) { hrtimer_init(&cmd->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); cmd->timer.function = null_cmd_timer_expired; } return cmd; } return NULL; } static struct nullb_cmd *alloc_cmd(struct nullb_queue *nq, struct bio *bio) { struct nullb_cmd *cmd; DEFINE_WAIT(wait); do { /* * This avoids multiple return statements, multiple calls to * __alloc_cmd() and a fast path call to prepare_to_wait(). */ cmd = __alloc_cmd(nq); if (cmd) { cmd->bio = bio; return cmd; } prepare_to_wait(&nq->wait, &wait, TASK_UNINTERRUPTIBLE); io_schedule(); finish_wait(&nq->wait, &wait); } while (1); } static void end_cmd(struct nullb_cmd *cmd) { int queue_mode = cmd->nq->dev->queue_mode; switch (queue_mode) { case NULL_Q_MQ: blk_mq_end_request(cmd->rq, cmd->error); return; case NULL_Q_BIO: cmd->bio->bi_status = cmd->error; bio_endio(cmd->bio); break; } free_cmd(cmd); } static enum hrtimer_restart null_cmd_timer_expired(struct hrtimer *timer) { end_cmd(container_of(timer, struct nullb_cmd, timer)); return HRTIMER_NORESTART; } static void null_cmd_end_timer(struct nullb_cmd *cmd) { ktime_t kt = cmd->nq->dev->completion_nsec; hrtimer_start(&cmd->timer, kt, HRTIMER_MODE_REL); } static void null_complete_rq(struct request *rq) { end_cmd(blk_mq_rq_to_pdu(rq)); } static struct nullb_page *null_alloc_page(void) { struct nullb_page *t_page; t_page = kmalloc(sizeof(struct nullb_page), GFP_NOIO); if (!t_page) return NULL; t_page->page = alloc_pages(GFP_NOIO, 0); if (!t_page->page) { kfree(t_page); return NULL; } memset(t_page->bitmap, 0, sizeof(t_page->bitmap)); return t_page; } static void null_free_page(struct nullb_page *t_page) { __set_bit(NULLB_PAGE_FREE, t_page->bitmap); if (test_bit(NULLB_PAGE_LOCK, t_page->bitmap)) return; __free_page(t_page->page); kfree(t_page); } static bool null_page_empty(struct nullb_page *page) { int size = MAP_SZ - 2; return find_first_bit(page->bitmap, size) == size; } static void null_free_sector(struct nullb *nullb, sector_t sector, bool is_cache) { unsigned int sector_bit; u64 idx; struct nullb_page *t_page, *ret; struct radix_tree_root *root; root = is_cache ? &nullb->dev->cache : &nullb->dev->data; idx = sector >> PAGE_SECTORS_SHIFT; sector_bit = (sector & SECTOR_MASK); t_page = radix_tree_lookup(root, idx); if (t_page) { __clear_bit(sector_bit, t_page->bitmap); if (null_page_empty(t_page)) { ret = radix_tree_delete_item(root, idx, t_page); WARN_ON(ret != t_page); null_free_page(ret); if (is_cache) nullb->dev->curr_cache -= PAGE_SIZE; } } } static struct nullb_page *null_radix_tree_insert(struct nullb *nullb, u64 idx, struct nullb_page *t_page, bool is_cache) { struct radix_tree_root *root; root = is_cache ? &nullb->dev->cache : &nullb->dev->data; if (radix_tree_insert(root, idx, t_page)) { null_free_page(t_page); t_page = radix_tree_lookup(root, idx); WARN_ON(!t_page || t_page->page->index != idx); } else if (is_cache) nullb->dev->curr_cache += PAGE_SIZE; return t_page; } static void null_free_device_storage(struct nullb_device *dev, bool is_cache) { unsigned long pos = 0; int nr_pages; struct nullb_page *ret, *t_pages[FREE_BATCH]; struct radix_tree_root *root; root = is_cache ? &dev->cache : &dev->data; do { int i; nr_pages = radix_tree_gang_lookup(root, (void **)t_pages, pos, FREE_BATCH); for (i = 0; i < nr_pages; i++) { pos = t_pages[i]->page->index; ret = radix_tree_delete_item(root, pos, t_pages[i]); WARN_ON(ret != t_pages[i]); null_free_page(ret); } pos++; } while (nr_pages == FREE_BATCH); if (is_cache) dev->curr_cache = 0; } static struct nullb_page *__null_lookup_page(struct nullb *nullb, sector_t sector, bool for_write, bool is_cache) { unsigned int sector_bit; u64 idx; struct nullb_page *t_page; struct radix_tree_root *root; idx = sector >> PAGE_SECTORS_SHIFT; sector_bit = (sector & SECTOR_MASK); root = is_cache ? &nullb->dev->cache : &nullb->dev->data; t_page = radix_tree_lookup(root, idx); WARN_ON(t_page && t_page->page->index != idx); if (t_page && (for_write || test_bit(sector_bit, t_page->bitmap))) return t_page; return NULL; } static struct nullb_page *null_lookup_page(struct nullb *nullb, sector_t sector, bool for_write, bool ignore_cache) { struct nullb_page *page = NULL; if (!ignore_cache) page = __null_lookup_page(nullb, sector, for_write, true); if (page) return page; return __null_lookup_page(nullb, sector, for_write, false); } static struct nullb_page *null_insert_page(struct nullb *nullb, sector_t sector, bool ignore_cache) __releases(&nullb->lock) __acquires(&nullb->lock) { u64 idx; struct nullb_page *t_page; t_page = null_lookup_page(nullb, sector, true, ignore_cache); if (t_page) return t_page; spin_unlock_irq(&nullb->lock); t_page = null_alloc_page(); if (!t_page) goto out_lock; if (radix_tree_preload(GFP_NOIO)) goto out_freepage; spin_lock_irq(&nullb->lock); idx = sector >> PAGE_SECTORS_SHIFT; t_page->page->index = idx; t_page = null_radix_tree_insert(nullb, idx, t_page, !ignore_cache); radix_tree_preload_end(); return t_page; out_freepage: null_free_page(t_page); out_lock: spin_lock_irq(&nullb->lock); return null_lookup_page(nullb, sector, true, ignore_cache); } static int null_flush_cache_page(struct nullb *nullb, struct nullb_page *c_page) { int i; unsigned int offset; u64 idx; struct nullb_page *t_page, *ret; void *dst, *src; idx = c_page->page->index; t_page = null_insert_page(nullb, idx << PAGE_SECTORS_SHIFT, true); __clear_bit(NULLB_PAGE_LOCK, c_page->bitmap); if (test_bit(NULLB_PAGE_FREE, c_page->bitmap)) { null_free_page(c_page); if (t_page && null_page_empty(t_page)) { ret = radix_tree_delete_item(&nullb->dev->data, idx, t_page); null_free_page(t_page); } return 0; } if (!t_page) return -ENOMEM; src = kmap_atomic(c_page->page); dst = kmap_atomic(t_page->page); for (i = 0; i < PAGE_SECTORS; i += (nullb->dev->blocksize >> SECTOR_SHIFT)) { if (test_bit(i, c_page->bitmap)) { offset = (i << SECTOR_SHIFT); memcpy(dst + offset, src + offset, nullb->dev->blocksize); __set_bit(i, t_page->bitmap); } } kunmap_atomic(dst); kunmap_atomic(src); ret = radix_tree_delete_item(&nullb->dev->cache, idx, c_page); null_free_page(ret); nullb->dev->curr_cache -= PAGE_SIZE; return 0; } static int null_make_cache_space(struct nullb *nullb, unsigned long n) { int i, err, nr_pages; struct nullb_page *c_pages[FREE_BATCH]; unsigned long flushed = 0, one_round; again: if ((nullb->dev->cache_size * 1024 * 1024) > nullb->dev->curr_cache + n || nullb->dev->curr_cache == 0) return 0; nr_pages = radix_tree_gang_lookup(&nullb->dev->cache, (void **)c_pages, nullb->cache_flush_pos, FREE_BATCH); /* * nullb_flush_cache_page could unlock before using the c_pages. To * avoid race, we don't allow page free */ for (i = 0; i < nr_pages; i++) { nullb->cache_flush_pos = c_pages[i]->page->index; /* * We found the page which is being flushed to disk by other * threads */ if (test_bit(NULLB_PAGE_LOCK, c_pages[i]->bitmap)) c_pages[i] = NULL; else __set_bit(NULLB_PAGE_LOCK, c_pages[i]->bitmap); } one_round = 0; for (i = 0; i < nr_pages; i++) { if (c_pages[i] == NULL) continue; err = null_flush_cache_page(nullb, c_pages[i]); if (err) return err; one_round++; } flushed += one_round << PAGE_SHIFT; if (n > flushed) { if (nr_pages == 0) nullb->cache_flush_pos = 0; if (one_round == 0) { /* give other threads a chance */ spin_unlock_irq(&nullb->lock); spin_lock_irq(&nullb->lock); } goto again; } return 0; } static int copy_to_nullb(struct nullb *nullb, struct page *source, unsigned int off, sector_t sector, size_t n, bool is_fua) { size_t temp, count = 0; unsigned int offset; struct nullb_page *t_page; void *dst, *src; while (count < n) { temp = min_t(size_t, nullb->dev->blocksize, n - count); if (null_cache_active(nullb) && !is_fua) null_make_cache_space(nullb, PAGE_SIZE); offset = (sector & SECTOR_MASK) << SECTOR_SHIFT; t_page = null_insert_page(nullb, sector, !null_cache_active(nullb) || is_fua); if (!t_page) return -ENOSPC; src = kmap_atomic(source); dst = kmap_atomic(t_page->page); memcpy(dst + offset, src + off + count, temp); kunmap_atomic(dst); kunmap_atomic(src); __set_bit(sector & SECTOR_MASK, t_page->bitmap); if (is_fua) null_free_sector(nullb, sector, true); count += temp; sector += temp >> SECTOR_SHIFT; } return 0; } static int copy_from_nullb(struct nullb *nullb, struct page *dest, unsigned int off, sector_t sector, size_t n) { size_t temp, count = 0; unsigned int offset; struct nullb_page *t_page; void *dst, *src; while (count < n) { temp = min_t(size_t, nullb->dev->blocksize, n - count); offset = (sector & SECTOR_MASK) << SECTOR_SHIFT; t_page = null_lookup_page(nullb, sector, false, !null_cache_active(nullb)); dst = kmap_atomic(dest); if (!t_page) { memset(dst + off + count, 0, temp); goto next; } src = kmap_atomic(t_page->page); memcpy(dst + off + count, src + offset, temp); kunmap_atomic(src); next: kunmap_atomic(dst); count += temp; sector += temp >> SECTOR_SHIFT; } return 0; } static void nullb_fill_pattern(struct nullb *nullb, struct page *page, unsigned int len, unsigned int off) { void *dst; dst = kmap_atomic(page); memset(dst + off, 0xFF, len); kunmap_atomic(dst); } blk_status_t null_handle_discard(struct nullb_device *dev, sector_t sector, sector_t nr_sectors) { struct nullb *nullb = dev->nullb; size_t n = nr_sectors << SECTOR_SHIFT; size_t temp; spin_lock_irq(&nullb->lock); while (n > 0) { temp = min_t(size_t, n, dev->blocksize); null_free_sector(nullb, sector, false); if (null_cache_active(nullb)) null_free_sector(nullb, sector, true); sector += temp >> SECTOR_SHIFT; n -= temp; } spin_unlock_irq(&nullb->lock); return BLK_STS_OK; } static int null_handle_flush(struct nullb *nullb) { int err; if (!null_cache_active(nullb)) return 0; spin_lock_irq(&nullb->lock); while (true) { err = null_make_cache_space(nullb, nullb->dev->cache_size * 1024 * 1024); if (err || nullb->dev->curr_cache == 0) break; } WARN_ON(!radix_tree_empty(&nullb->dev->cache)); spin_unlock_irq(&nullb->lock); return err; } static int null_transfer(struct nullb *nullb, struct page *page, unsigned int len, unsigned int off, bool is_write, sector_t sector, bool is_fua) { struct nullb_device *dev = nullb->dev; unsigned int valid_len = len; int err = 0; if (!is_write) { if (dev->zoned) valid_len = null_zone_valid_read_len(nullb, sector, len); if (valid_len) { err = copy_from_nullb(nullb, page, off, sector, valid_len); off += valid_len; len -= valid_len; } if (len) nullb_fill_pattern(nullb, page, len, off); flush_dcache_page(page); } else { flush_dcache_page(page); err = copy_to_nullb(nullb, page, off, sector, len, is_fua); } return err; } static int null_handle_rq(struct nullb_cmd *cmd) { struct request *rq = cmd->rq; struct nullb *nullb = cmd->nq->dev->nullb; int err; unsigned int len; sector_t sector = blk_rq_pos(rq); struct req_iterator iter; struct bio_vec bvec; spin_lock_irq(&nullb->lock); rq_for_each_segment(bvec, rq, iter) { len = bvec.bv_len; err = null_transfer(nullb, bvec.bv_page, len, bvec.bv_offset, op_is_write(req_op(rq)), sector, rq->cmd_flags & REQ_FUA); if (err) { spin_unlock_irq(&nullb->lock); return err; } sector += len >> SECTOR_SHIFT; } spin_unlock_irq(&nullb->lock); return 0; } static int null_handle_bio(struct nullb_cmd *cmd) { struct bio *bio = cmd->bio; struct nullb *nullb = cmd->nq->dev->nullb; int err; unsigned int len; sector_t sector = bio->bi_iter.bi_sector; struct bio_vec bvec; struct bvec_iter iter; spin_lock_irq(&nullb->lock); bio_for_each_segment(bvec, bio, iter) { len = bvec.bv_len; err = null_transfer(nullb, bvec.bv_page, len, bvec.bv_offset, op_is_write(bio_op(bio)), sector, bio->bi_opf & REQ_FUA); if (err) { spin_unlock_irq(&nullb->lock); return err; } sector += len >> SECTOR_SHIFT; } spin_unlock_irq(&nullb->lock); return 0; } static void null_stop_queue(struct nullb *nullb) { struct request_queue *q = nullb->q; if (nullb->dev->queue_mode == NULL_Q_MQ) blk_mq_stop_hw_queues(q); } static void null_restart_queue_async(struct nullb *nullb) { struct request_queue *q = nullb->q; if (nullb->dev->queue_mode == NULL_Q_MQ) blk_mq_start_stopped_hw_queues(q, true); } static inline blk_status_t null_handle_throttled(struct nullb_cmd *cmd) { struct nullb_device *dev = cmd->nq->dev; struct nullb *nullb = dev->nullb; blk_status_t sts = BLK_STS_OK; struct request *rq = cmd->rq; if (!hrtimer_active(&nullb->bw_timer)) hrtimer_restart(&nullb->bw_timer); if (atomic_long_sub_return(blk_rq_bytes(rq), &nullb->cur_bytes) < 0) { null_stop_queue(nullb); /* race with timer */ if (atomic_long_read(&nullb->cur_bytes) > 0) null_restart_queue_async(nullb); /* requeue request */ sts = BLK_STS_DEV_RESOURCE; } return sts; } static inline blk_status_t null_handle_badblocks(struct nullb_cmd *cmd, sector_t sector, sector_t nr_sectors) { struct badblocks *bb = &cmd->nq->dev->badblocks; sector_t first_bad; int bad_sectors; if (badblocks_check(bb, sector, nr_sectors, &first_bad, &bad_sectors)) return BLK_STS_IOERR; return BLK_STS_OK; } static inline blk_status_t null_handle_memory_backed(struct nullb_cmd *cmd, enum req_op op, sector_t sector, sector_t nr_sectors) { struct nullb_device *dev = cmd->nq->dev; int err; if (op == REQ_OP_DISCARD) return null_handle_discard(dev, sector, nr_sectors); if (dev->queue_mode == NULL_Q_BIO) err = null_handle_bio(cmd); else err = null_handle_rq(cmd); return errno_to_blk_status(err); } static void nullb_zero_read_cmd_buffer(struct nullb_cmd *cmd) { struct nullb_device *dev = cmd->nq->dev; struct bio *bio; if (dev->memory_backed) return; if (dev->queue_mode == NULL_Q_BIO && bio_op(cmd->bio) == REQ_OP_READ) { zero_fill_bio(cmd->bio); } else if (req_op(cmd->rq) == REQ_OP_READ) { __rq_for_each_bio(bio, cmd->rq) zero_fill_bio(bio); } } static inline void nullb_complete_cmd(struct nullb_cmd *cmd) { /* * Since root privileges are required to configure the null_blk * driver, it is fine that this driver does not initialize the * data buffers of read commands. Zero-initialize these buffers * anyway if KMSAN is enabled to prevent that KMSAN complains * about null_blk not initializing read data buffers. */ if (IS_ENABLED(CONFIG_KMSAN)) nullb_zero_read_cmd_buffer(cmd); /* Complete IO by inline, softirq or timer */ switch (cmd->nq->dev->irqmode) { case NULL_IRQ_SOFTIRQ: switch (cmd->nq->dev->queue_mode) { case NULL_Q_MQ: if (likely(!blk_should_fake_timeout(cmd->rq->q))) blk_mq_complete_request(cmd->rq); break; case NULL_Q_BIO: /* * XXX: no proper submitting cpu information available. */ end_cmd(cmd); break; } break; case NULL_IRQ_NONE: end_cmd(cmd); break; case NULL_IRQ_TIMER: null_cmd_end_timer(cmd); break; } } blk_status_t null_process_cmd(struct nullb_cmd *cmd, enum req_op op, sector_t sector, unsigned int nr_sectors) { struct nullb_device *dev = cmd->nq->dev; blk_status_t ret; if (dev->badblocks.shift != -1) { ret = null_handle_badblocks(cmd, sector, nr_sectors); if (ret != BLK_STS_OK) return ret; } if (dev->memory_backed) return null_handle_memory_backed(cmd, op, sector, nr_sectors); return BLK_STS_OK; } static blk_status_t null_handle_cmd(struct nullb_cmd *cmd, sector_t sector, sector_t nr_sectors, enum req_op op) { struct nullb_device *dev = cmd->nq->dev; struct nullb *nullb = dev->nullb; blk_status_t sts; if (test_bit(NULLB_DEV_FL_THROTTLED, &dev->flags)) { sts = null_handle_throttled(cmd); if (sts != BLK_STS_OK) return sts; } if (op == REQ_OP_FLUSH) { cmd->error = errno_to_blk_status(null_handle_flush(nullb)); goto out; } if (dev->zoned) sts = null_process_zoned_cmd(cmd, op, sector, nr_sectors); else sts = null_process_cmd(cmd, op, sector, nr_sectors); /* Do not overwrite errors (e.g. timeout errors) */ if (cmd->error == BLK_STS_OK) cmd->error = sts; out: nullb_complete_cmd(cmd); return BLK_STS_OK; } static enum hrtimer_restart nullb_bwtimer_fn(struct hrtimer *timer) { struct nullb *nullb = container_of(timer, struct nullb, bw_timer); ktime_t timer_interval = ktime_set(0, TIMER_INTERVAL); unsigned int mbps = nullb->dev->mbps; if (atomic_long_read(&nullb->cur_bytes) == mb_per_tick(mbps)) return HRTIMER_NORESTART; atomic_long_set(&nullb->cur_bytes, mb_per_tick(mbps)); null_restart_queue_async(nullb); hrtimer_forward_now(&nullb->bw_timer, timer_interval); return HRTIMER_RESTART; } static void nullb_setup_bwtimer(struct nullb *nullb) { ktime_t timer_interval = ktime_set(0, TIMER_INTERVAL); hrtimer_init(&nullb->bw_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); nullb->bw_timer.function = nullb_bwtimer_fn; atomic_long_set(&nullb->cur_bytes, mb_per_tick(nullb->dev->mbps)); hrtimer_start(&nullb->bw_timer, timer_interval, HRTIMER_MODE_REL); } static struct nullb_queue *nullb_to_queue(struct nullb *nullb) { int index = 0; if (nullb->nr_queues != 1) index = raw_smp_processor_id() / ((nr_cpu_ids + nullb->nr_queues - 1) / nullb->nr_queues); return &nullb->queues[index]; } static void null_submit_bio(struct bio *bio) { sector_t sector = bio->bi_iter.bi_sector; sector_t nr_sectors = bio_sectors(bio); struct nullb *nullb = bio->bi_bdev->bd_disk->private_data; struct nullb_queue *nq = nullb_to_queue(nullb); null_handle_cmd(alloc_cmd(nq, bio), sector, nr_sectors, bio_op(bio)); } static bool should_timeout_request(struct request *rq) { #ifdef CONFIG_BLK_DEV_NULL_BLK_FAULT_INJECTION if (g_timeout_str[0]) return should_fail(&null_timeout_attr, 1); #endif return false; } static bool should_requeue_request(struct request *rq) { #ifdef CONFIG_BLK_DEV_NULL_BLK_FAULT_INJECTION if (g_requeue_str[0]) return should_fail(&null_requeue_attr, 1); #endif return false; } static void null_map_queues(struct blk_mq_tag_set *set) { struct nullb *nullb = set->driver_data; int i, qoff; unsigned int submit_queues = g_submit_queues; unsigned int poll_queues = g_poll_queues; if (nullb) { struct nullb_device *dev = nullb->dev; /* * Refer nr_hw_queues of the tag set to check if the expected * number of hardware queues are prepared. If block layer failed * to prepare them, use previous numbers of submit queues and * poll queues to map queues. */ if (set->nr_hw_queues == dev->submit_queues + dev->poll_queues) { submit_queues = dev->submit_queues; poll_queues = dev->poll_queues; } else if (set->nr_hw_queues == dev->prev_submit_queues + dev->prev_poll_queues) { submit_queues = dev->prev_submit_queues; poll_queues = dev->prev_poll_queues; } else { pr_warn("tag set has unexpected nr_hw_queues: %d\n", set->nr_hw_queues); WARN_ON_ONCE(true); submit_queues = 1; poll_queues = 0; } } for (i = 0, qoff = 0; i < set->nr_maps; i++) { struct blk_mq_queue_map *map = &set->map[i]; switch (i) { case HCTX_TYPE_DEFAULT: map->nr_queues = submit_queues; break; case HCTX_TYPE_READ: map->nr_queues = 0; continue; case HCTX_TYPE_POLL: map->nr_queues = poll_queues; break; } map->queue_offset = qoff; qoff += map->nr_queues; blk_mq_map_queues(map); } } static int null_poll(struct blk_mq_hw_ctx *hctx, struct io_comp_batch *iob) { struct nullb_queue *nq = hctx->driver_data; LIST_HEAD(list); int nr = 0; spin_lock(&nq->poll_lock); list_splice_init(&nq->poll_list, &list); spin_unlock(&nq->poll_lock); while (!list_empty(&list)) { struct nullb_cmd *cmd; struct request *req; req = list_first_entry(&list, struct request, queuelist); list_del_init(&req->queuelist); cmd = blk_mq_rq_to_pdu(req); cmd->error = null_process_cmd(cmd, req_op(req), blk_rq_pos(req), blk_rq_sectors(req)); if (!blk_mq_add_to_batch(req, iob, (__force int) cmd->error, blk_mq_end_request_batch)) end_cmd(cmd); nr++; } return nr; } static enum blk_eh_timer_return null_timeout_rq(struct request *rq) { struct blk_mq_hw_ctx *hctx = rq->mq_hctx; struct nullb_cmd *cmd = blk_mq_rq_to_pdu(rq); pr_info("rq %p timed out\n", rq); if (hctx->type == HCTX_TYPE_POLL) { struct nullb_queue *nq = hctx->driver_data; spin_lock(&nq->poll_lock); list_del_init(&rq->queuelist); spin_unlock(&nq->poll_lock); } /* * If the device is marked as blocking (i.e. memory backed or zoned * device), the submission path may be blocked waiting for resources * and cause real timeouts. For these real timeouts, the submission * path will complete the request using blk_mq_complete_request(). * Only fake timeouts need to execute blk_mq_complete_request() here. */ cmd->error = BLK_STS_TIMEOUT; if (cmd->fake_timeout || hctx->type == HCTX_TYPE_POLL) blk_mq_complete_request(rq); return BLK_EH_DONE; } static blk_status_t null_queue_rq(struct blk_mq_hw_ctx *hctx, const struct blk_mq_queue_data *bd) { struct nullb_cmd *cmd = blk_mq_rq_to_pdu(bd->rq); struct nullb_queue *nq = hctx->driver_data; sector_t nr_sectors = blk_rq_sectors(bd->rq); sector_t sector = blk_rq_pos(bd->rq); const bool is_poll = hctx->type == HCTX_TYPE_POLL; might_sleep_if(hctx->flags & BLK_MQ_F_BLOCKING); if (!is_poll && nq->dev->irqmode == NULL_IRQ_TIMER) { hrtimer_init(&cmd->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); cmd->timer.function = null_cmd_timer_expired; } cmd->rq = bd->rq; cmd->error = BLK_STS_OK; cmd->nq = nq; cmd->fake_timeout = should_timeout_request(bd->rq); blk_mq_start_request(bd->rq); if (should_requeue_request(bd->rq)) { /* * Alternate between hitting the core BUSY path, and the * driver driven requeue path */ nq->requeue_selection++; if (nq->requeue_selection & 1) return BLK_STS_RESOURCE; else { blk_mq_requeue_request(bd->rq, true); return BLK_STS_OK; } } if (is_poll) { spin_lock(&nq->poll_lock); list_add_tail(&bd->rq->queuelist, &nq->poll_list); spin_unlock(&nq->poll_lock); return BLK_STS_OK; } if (cmd->fake_timeout) return BLK_STS_OK; return null_handle_cmd(cmd, sector, nr_sectors, req_op(bd->rq)); } static void cleanup_queue(struct nullb_queue *nq) { bitmap_free(nq->tag_map); kfree(nq->cmds); } static void cleanup_queues(struct nullb *nullb) { int i; for (i = 0; i < nullb->nr_queues; i++) cleanup_queue(&nullb->queues[i]); kfree(nullb->queues); } static void null_exit_hctx(struct blk_mq_hw_ctx *hctx, unsigned int hctx_idx) { struct nullb_queue *nq = hctx->driver_data; struct nullb *nullb = nq->dev->nullb; nullb->nr_queues--; } static void null_init_queue(struct nullb *nullb, struct nullb_queue *nq) { init_waitqueue_head(&nq->wait); nq->queue_depth = nullb->queue_depth; nq->dev = nullb->dev; INIT_LIST_HEAD(&nq->poll_list); spin_lock_init(&nq->poll_lock); } static int null_init_hctx(struct blk_mq_hw_ctx *hctx, void *driver_data, unsigned int hctx_idx) { struct nullb *nullb = hctx->queue->queuedata; struct nullb_queue *nq; #ifdef CONFIG_BLK_DEV_NULL_BLK_FAULT_INJECTION if (g_init_hctx_str[0] && should_fail(&null_init_hctx_attr, 1)) return -EFAULT; #endif nq = &nullb->queues[hctx_idx]; hctx->driver_data = nq; null_init_queue(nullb, nq); nullb->nr_queues++; return 0; } static const struct blk_mq_ops null_mq_ops = { .queue_rq = null_queue_rq, .complete = null_complete_rq, .timeout = null_timeout_rq, .poll = null_poll, .map_queues = null_map_queues, .init_hctx = null_init_hctx, .exit_hctx = null_exit_hctx, }; static void null_del_dev(struct nullb *nullb) { struct nullb_device *dev; if (!nullb) return; dev = nullb->dev; ida_simple_remove(&nullb_indexes, nullb->index); list_del_init(&nullb->list); del_gendisk(nullb->disk); if (test_bit(NULLB_DEV_FL_THROTTLED, &nullb->dev->flags)) { hrtimer_cancel(&nullb->bw_timer); atomic_long_set(&nullb->cur_bytes, LONG_MAX); null_restart_queue_async(nullb); } put_disk(nullb->disk); if (dev->queue_mode == NULL_Q_MQ && nullb->tag_set == &nullb->__tag_set) blk_mq_free_tag_set(nullb->tag_set); cleanup_queues(nullb); if (null_cache_active(nullb)) null_free_device_storage(nullb->dev, true); kfree(nullb); dev->nullb = NULL; } static void null_config_discard(struct nullb *nullb) { if (nullb->dev->discard == false) return; if (!nullb->dev->memory_backed) { nullb->dev->discard = false; pr_info("discard option is ignored without memory backing\n"); return; } if (nullb->dev->zoned) { nullb->dev->discard = false; pr_info("discard option is ignored in zoned mode\n"); return; } nullb->q->limits.discard_granularity = nullb->dev->blocksize; blk_queue_max_discard_sectors(nullb->q, UINT_MAX >> 9); } static const struct block_device_operations null_bio_ops = { .owner = THIS_MODULE, .submit_bio = null_submit_bio, .report_zones = null_report_zones, }; static const struct block_device_operations null_rq_ops = { .owner = THIS_MODULE, .report_zones = null_report_zones, }; static int setup_commands(struct nullb_queue *nq) { struct nullb_cmd *cmd; int i; nq->cmds = kcalloc(nq->queue_depth, sizeof(*cmd), GFP_KERNEL); if (!nq->cmds) return -ENOMEM; nq->tag_map = bitmap_zalloc(nq->queue_depth, GFP_KERNEL); if (!nq->tag_map) { kfree(nq->cmds); return -ENOMEM; } for (i = 0; i < nq->queue_depth; i++) { cmd = &nq->cmds[i]; cmd->tag = -1U; } return 0; } static int setup_queues(struct nullb *nullb) { int nqueues = nr_cpu_ids; if (g_poll_queues) nqueues += g_poll_queues; nullb->queues = kcalloc(nqueues, sizeof(struct nullb_queue), GFP_KERNEL); if (!nullb->queues) return -ENOMEM; nullb->queue_depth = nullb->dev->hw_queue_depth; return 0; } static int init_driver_queues(struct nullb *nullb) { struct nullb_queue *nq; int i, ret = 0; for (i = 0; i < nullb->dev->submit_queues; i++) { nq = &nullb->queues[i]; null_init_queue(nullb, nq); ret = setup_commands(nq); if (ret) return ret; nullb->nr_queues++; } return 0; } static int null_gendisk_register(struct nullb *nullb) { sector_t size = ((sector_t)nullb->dev->size * SZ_1M) >> SECTOR_SHIFT; struct gendisk *disk = nullb->disk; set_capacity(disk, size); disk->major = null_major; disk->first_minor = nullb->index; disk->minors = 1; if (queue_is_mq(nullb->q)) disk->fops = &null_rq_ops; else disk->fops = &null_bio_ops; disk->private_data = nullb; strncpy(disk->disk_name, nullb->disk_name, DISK_NAME_LEN); if (nullb->dev->zoned) { int ret = null_register_zoned_dev(nullb); if (ret) return ret; } return add_disk(disk); } static int null_init_tag_set(struct nullb *nullb, struct blk_mq_tag_set *set) { unsigned int flags = BLK_MQ_F_SHOULD_MERGE; int hw_queues, numa_node; unsigned int queue_depth; int poll_queues; if (nullb) { hw_queues = nullb->dev->submit_queues; poll_queues = nullb->dev->poll_queues; queue_depth = nullb->dev->hw_queue_depth; numa_node = nullb->dev->home_node; if (nullb->dev->no_sched) flags |= BLK_MQ_F_NO_SCHED; if (nullb->dev->shared_tag_bitmap) flags |= BLK_MQ_F_TAG_HCTX_SHARED; if (nullb->dev->blocking) flags |= BLK_MQ_F_BLOCKING; } else { hw_queues = g_submit_queues; poll_queues = g_poll_queues; queue_depth = g_hw_queue_depth; numa_node = g_home_node; if (g_no_sched) flags |= BLK_MQ_F_NO_SCHED; if (g_shared_tag_bitmap) flags |= BLK_MQ_F_TAG_HCTX_SHARED; if (g_blocking) flags |= BLK_MQ_F_BLOCKING; } set->ops = &null_mq_ops; set->cmd_size = sizeof(struct nullb_cmd); set->flags = flags; set->driver_data = nullb; set->nr_hw_queues = hw_queues; set->queue_depth = queue_depth; set->numa_node = numa_node; if (poll_queues) { set->nr_hw_queues += poll_queues; set->nr_maps = 3; } else { set->nr_maps = 1; } return blk_mq_alloc_tag_set(set); } static int null_validate_conf(struct nullb_device *dev) { dev->blocksize = round_down(dev->blocksize, 512); dev->blocksize = clamp_t(unsigned int, dev->blocksize, 512, 4096); if (dev->queue_mode == NULL_Q_MQ && dev->use_per_node_hctx) { if (dev->submit_queues != nr_online_nodes) dev->submit_queues = nr_online_nodes; } else if (dev->submit_queues > nr_cpu_ids) dev->submit_queues = nr_cpu_ids; else if (dev->submit_queues == 0) dev->submit_queues = 1; dev->prev_submit_queues = dev->submit_queues; if (dev->poll_queues > g_poll_queues) dev->poll_queues = g_poll_queues; dev->prev_poll_queues = dev->poll_queues; dev->queue_mode = min_t(unsigned int, dev->queue_mode, NULL_Q_MQ); dev->irqmode = min_t(unsigned int, dev->irqmode, NULL_IRQ_TIMER); /* Do memory allocation, so set blocking */ if (dev->memory_backed) dev->blocking = true; else /* cache is meaningless */ dev->cache_size = 0; dev->cache_size = min_t(unsigned long, ULONG_MAX / 1024 / 1024, dev->cache_size); dev->mbps = min_t(unsigned int, 1024 * 40, dev->mbps); /* can not stop a queue */ if (dev->queue_mode == NULL_Q_BIO) dev->mbps = 0; if (dev->zoned && (!dev->zone_size || !is_power_of_2(dev->zone_size))) { pr_err("zone_size must be power-of-two\n"); return -EINVAL; } return 0; } #ifdef CONFIG_BLK_DEV_NULL_BLK_FAULT_INJECTION static bool __null_setup_fault(struct fault_attr *attr, char *str) { if (!str[0]) return true; if (!setup_fault_attr(attr, str)) return false; attr->verbose = 0; return true; } #endif static bool null_setup_fault(void) { #ifdef CONFIG_BLK_DEV_NULL_BLK_FAULT_INJECTION if (!__null_setup_fault(&null_timeout_attr, g_timeout_str)) return false; if (!__null_setup_fault(&null_requeue_attr, g_requeue_str)) return false; if (!__null_setup_fault(&null_init_hctx_attr, g_init_hctx_str)) return false; #endif return true; } static int null_add_dev(struct nullb_device *dev) { struct nullb *nullb; int rv; rv = null_validate_conf(dev); if (rv) return rv; nullb = kzalloc_node(sizeof(*nullb), GFP_KERNEL, dev->home_node); if (!nullb) { rv = -ENOMEM; goto out; } nullb->dev = dev; dev->nullb = nullb; spin_lock_init(&nullb->lock); rv = setup_queues(nullb); if (rv) goto out_free_nullb; if (dev->queue_mode == NULL_Q_MQ) { if (shared_tags) { nullb->tag_set = &tag_set; rv = 0; } else { nullb->tag_set = &nullb->__tag_set; rv = null_init_tag_set(nullb, nullb->tag_set); } if (rv) goto out_cleanup_queues; if (!null_setup_fault()) goto out_cleanup_tags; nullb->tag_set->timeout = 5 * HZ; nullb->disk = blk_mq_alloc_disk(nullb->tag_set, nullb); if (IS_ERR(nullb->disk)) { rv = PTR_ERR(nullb->disk); goto out_cleanup_tags; } nullb->q = nullb->disk->queue; } else if (dev->queue_mode == NULL_Q_BIO) { rv = -ENOMEM; nullb->disk = blk_alloc_disk(nullb->dev->home_node); if (!nullb->disk) goto out_cleanup_queues; nullb->q = nullb->disk->queue; rv = init_driver_queues(nullb); if (rv) goto out_cleanup_disk; } if (dev->mbps) { set_bit(NULLB_DEV_FL_THROTTLED, &dev->flags); nullb_setup_bwtimer(nullb); } if (dev->cache_size > 0) { set_bit(NULLB_DEV_FL_CACHE, &nullb->dev->flags); blk_queue_write_cache(nullb->q, true, true); } if (dev->zoned) { rv = null_init_zoned_dev(dev, nullb->q); if (rv) goto out_cleanup_disk; } nullb->q->queuedata = nullb; blk_queue_flag_set(QUEUE_FLAG_NONROT, nullb->q); blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, nullb->q); mutex_lock(&lock); rv = ida_simple_get(&nullb_indexes, 0, 0, GFP_KERNEL); if (rv < 0) { mutex_unlock(&lock); goto out_cleanup_zone; } nullb->index = rv; dev->index = rv; mutex_unlock(&lock); blk_queue_logical_block_size(nullb->q, dev->blocksize); blk_queue_physical_block_size(nullb->q, dev->blocksize); if (!dev->max_sectors) dev->max_sectors = queue_max_hw_sectors(nullb->q); dev->max_sectors = min_t(unsigned int, dev->max_sectors, BLK_DEF_MAX_SECTORS); blk_queue_max_hw_sectors(nullb->q, dev->max_sectors); if (dev->virt_boundary) blk_queue_virt_boundary(nullb->q, PAGE_SIZE - 1); null_config_discard(nullb); if (config_item_name(&dev->item)) { /* Use configfs dir name as the device name */ snprintf(nullb->disk_name, sizeof(nullb->disk_name), "%s", config_item_name(&dev->item)); } else { sprintf(nullb->disk_name, "nullb%d", nullb->index); } rv = null_gendisk_register(nullb); if (rv) goto out_ida_free; mutex_lock(&lock); list_add_tail(&nullb->list, &nullb_list); mutex_unlock(&lock); pr_info("disk %s created\n", nullb->disk_name); return 0; out_ida_free: ida_free(&nullb_indexes, nullb->index); out_cleanup_zone: null_free_zoned_dev(dev); out_cleanup_disk: put_disk(nullb->disk); out_cleanup_tags: if (dev->queue_mode == NULL_Q_MQ && nullb->tag_set == &nullb->__tag_set) blk_mq_free_tag_set(nullb->tag_set); out_cleanup_queues: cleanup_queues(nullb); out_free_nullb: kfree(nullb); dev->nullb = NULL; out: return rv; } static struct nullb *null_find_dev_by_name(const char *name) { struct nullb *nullb = NULL, *nb; mutex_lock(&lock); list_for_each_entry(nb, &nullb_list, list) { if (strcmp(nb->disk_name, name) == 0) { nullb = nb; break; } } mutex_unlock(&lock); return nullb; } static int null_create_dev(void) { struct nullb_device *dev; int ret; dev = null_alloc_dev(); if (!dev) return -ENOMEM; ret = null_add_dev(dev); if (ret) { null_free_dev(dev); return ret; } return 0; } static void null_destroy_dev(struct nullb *nullb) { struct nullb_device *dev = nullb->dev; null_del_dev(nullb); null_free_dev(dev); } static int __init null_init(void) { int ret = 0; unsigned int i; struct nullb *nullb; if (g_bs > PAGE_SIZE) { pr_warn("invalid block size\n"); pr_warn("defaults block size to %lu\n", PAGE_SIZE); g_bs = PAGE_SIZE; } if (g_max_sectors > BLK_DEF_MAX_SECTORS) { pr_warn("invalid max sectors\n"); pr_warn("defaults max sectors to %u\n", BLK_DEF_MAX_SECTORS); g_max_sectors = BLK_DEF_MAX_SECTORS; } if (g_home_node != NUMA_NO_NODE && g_home_node >= nr_online_nodes) { pr_err("invalid home_node value\n"); g_home_node = NUMA_NO_NODE; } if (g_queue_mode == NULL_Q_RQ) { pr_err("legacy IO path is no longer available\n"); return -EINVAL; } if (g_queue_mode == NULL_Q_MQ && g_use_per_node_hctx) { if (g_submit_queues != nr_online_nodes) { pr_warn("submit_queues param is set to %u.\n", nr_online_nodes); g_submit_queues = nr_online_nodes; } } else if (g_submit_queues > nr_cpu_ids) { g_submit_queues = nr_cpu_ids; } else if (g_submit_queues <= 0) { g_submit_queues = 1; } if (g_queue_mode == NULL_Q_MQ && shared_tags) { ret = null_init_tag_set(NULL, &tag_set); if (ret) return ret; } config_group_init(&nullb_subsys.su_group); mutex_init(&nullb_subsys.su_mutex); ret = configfs_register_subsystem(&nullb_subsys); if (ret) goto err_tagset; mutex_init(&lock); null_major = register_blkdev(0, "nullb"); if (null_major < 0) { ret = null_major; goto err_conf; } for (i = 0; i < nr_devices; i++) { ret = null_create_dev(); if (ret) goto err_dev; } pr_info("module loaded\n"); return 0; err_dev: while (!list_empty(&nullb_list)) { nullb = list_entry(nullb_list.next, struct nullb, list); null_destroy_dev(nullb); } unregister_blkdev(null_major, "nullb"); err_conf: configfs_unregister_subsystem(&nullb_subsys); err_tagset: if (g_queue_mode == NULL_Q_MQ && shared_tags) blk_mq_free_tag_set(&tag_set); return ret; } static void __exit null_exit(void) { struct nullb *nullb; configfs_unregister_subsystem(&nullb_subsys); unregister_blkdev(null_major, "nullb"); mutex_lock(&lock); while (!list_empty(&nullb_list)) { nullb = list_entry(nullb_list.next, struct nullb, list); null_destroy_dev(nullb); } mutex_unlock(&lock); if (g_queue_mode == NULL_Q_MQ && shared_tags) blk_mq_free_tag_set(&tag_set); } module_init(null_init); module_exit(null_exit); MODULE_AUTHOR("Jens Axboe <axboe@kernel.dk>"); MODULE_LICENSE("GPL");
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