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s390/dasd: fix string length handling
[linux-block.git] / drivers / block / null_blk / main.c
CommitLineData
09c434b8 1// SPDX-License-Identifier: GPL-2.0-only
3bf2bd20
SL		 2/*
3 * Add configfs and memory store: Kyungchan Koh <kkc6196@fb.com> and
4 * Shaohua Li <shli@fb.com>
5 */
f2298c04 6#include <linux/module.h>
fc1bc354 7
f2298c04
JA		 8#include <linux/moduleparam.h>
9#include <linux/sched.h>
10#include <linux/fs.h>
f2298c04 11#include <linux/init.h>
6dad38d3 12#include "null_blk.h"
f2298c04 13
db060f54
DLM		 14#undef pr_fmt
15#define pr_fmt(fmt) "null_blk: " fmt
16
5bcd0e0c
SL		 17#define FREE_BATCH 16
18
eff2c4f1
SL		 19#define TICKS_PER_SEC 50ULL
20#define TIMER_INTERVAL (NSEC_PER_SEC / TICKS_PER_SEC)
21
33f782c4 22#ifdef CONFIG_BLK_DEV_NULL_BLK_FAULT_INJECTION
93b57046 23static DECLARE_FAULT_ATTR(null_timeout_attr);
24941b90 24static DECLARE_FAULT_ATTR(null_requeue_attr);
596444e7 25static DECLARE_FAULT_ATTR(null_init_hctx_attr);
33f782c4 26#endif
93b57046 27
eff2c4f1
SL		 28static inline u64 mb_per_tick(int mbps)
29{
30 return (1 << 20) / TICKS_PER_SEC * ((u64) mbps);
31}
f2298c04 32
3bf2bd20
SL		 33/*
34 * Status flags for nullb_device.
35 *
36 * CONFIGURED: Device has been configured and turned on. Cannot reconfigure.
37 * UP: Device is currently on and visible in userspace.
eff2c4f1 38 * THROTTLED: Device is being throttled.
deb78b41 39 * CACHE: Device is using a write-back cache.
3bf2bd20
SL		 40 */
41enum nullb_device_flags {
42 NULLB_DEV_FL_CONFIGURED = 0,
43 NULLB_DEV_FL_UP = 1,
eff2c4f1 44 NULLB_DEV_FL_THROTTLED = 2,
deb78b41 45 NULLB_DEV_FL_CACHE = 3,
3bf2bd20
SL		 46};
47
66231ad3 48#define MAP_SZ ((PAGE_SIZE >> SECTOR_SHIFT) + 2)
5bcd0e0c
SL		 49/*
50 * nullb_page is a page in memory for nullb devices.
51 *
52 * @page: The page holding the data.
53 * @bitmap: The bitmap represents which sector in the page has data.
54 * Each bit represents one block size. For example, sector 8
55 * will use the 7th bit
deb78b41
SL		 56 * The highest 2 bits of bitmap are for special purpose. LOCK means the cache
57 * page is being flushing to storage. FREE means the cache page is freed and
58 * should be skipped from flushing to storage. Please see
59 * null_make_cache_space
5bcd0e0c
SL		 60 */
61struct nullb_page {
62 struct page *page;
66231ad3 63 DECLARE_BITMAP(bitmap, MAP_SZ);
5bcd0e0c 64};
66231ad3
ML		 65#define NULLB_PAGE_LOCK (MAP_SZ - 1)
66#define NULLB_PAGE_FREE (MAP_SZ - 2)
5bcd0e0c 67
f2298c04
JA		 68static LIST_HEAD(nullb_list);
69static struct mutex lock;
70static int null_major;
94bc02e3 71static DEFINE_IDA(nullb_indexes);
82f402fe 72static struct blk_mq_tag_set tag_set;
f2298c04 73
f2298c04
JA		 74enum {
75 NULL_IRQ_NONE = 0,
76 NULL_IRQ_SOFTIRQ = 1,
77 NULL_IRQ_TIMER = 2,
ce2c350b 78};
f2298c04 79
cee1b215
MG		 80static bool g_virt_boundary = false;
81module_param_named(virt_boundary, g_virt_boundary, bool, 0444);
82MODULE_PARM_DESC(virt_boundary, "Require a virtual boundary for the device. Default: False");
83
b3cffc38 84static int g_no_sched;
5657a819 85module_param_named(no_sched, g_no_sched, int, 0444);
b3cffc38 86MODULE_PARM_DESC(no_sched, "No io scheduler");
87
2984c868 88static int g_submit_queues = 1;
5657a819 89module_param_named(submit_queues, g_submit_queues, int, 0444);
f2298c04
JA		 90MODULE_PARM_DESC(submit_queues, "Number of submission queues");
91
0a593fbb
JA		 92static int g_poll_queues = 1;
93module_param_named(poll_queues, g_poll_queues, int, 0444);
94MODULE_PARM_DESC(poll_queues, "Number of IOPOLL submission queues");
95
2984c868 96static int g_home_node = NUMA_NO_NODE;
5657a819 97module_param_named(home_node, g_home_node, int, 0444);
f2298c04
JA		 98MODULE_PARM_DESC(home_node, "Home node for the device");
99
33f782c4 100#ifdef CONFIG_BLK_DEV_NULL_BLK_FAULT_INJECTION
290df92a
DZ		 101/*
102 * For more details about fault injection, please refer to
103 * Documentation/fault-injection/fault-injection.rst.
104 */
93b57046 105static char g_timeout_str[80];
5657a819 106module_param_string(timeout, g_timeout_str, sizeof(g_timeout_str), 0444);
290df92a 107MODULE_PARM_DESC(timeout, "Fault injection. timeout=<interval>,<probability>,<space>,<times>");
24941b90
JA		 108
109static char g_requeue_str[80];
5657a819 110module_param_string(requeue, g_requeue_str, sizeof(g_requeue_str), 0444);
290df92a 111MODULE_PARM_DESC(requeue, "Fault injection. requeue=<interval>,<probability>,<space>,<times>");
596444e7
BVA		 112
113static char g_init_hctx_str[80];
114module_param_string(init_hctx, g_init_hctx_str, sizeof(g_init_hctx_str), 0444);
290df92a 115MODULE_PARM_DESC(init_hctx, "Fault injection to fail hctx init. init_hctx=<interval>,<probability>,<space>,<times>");
33f782c4 116#endif
93b57046 117
2984c868 118static int g_queue_mode = NULL_Q_MQ;
709c8667
MB		 119
120static int null_param_store_val(const char *str, int *val, int min, int max)
121{
122 int ret, new_val;
123
124 ret = kstrtoint(str, 10, &new_val);
125 if (ret)
126 return -EINVAL;
127
128 if (new_val < min || new_val > max)
129 return -EINVAL;
130
131 *val = new_val;
132 return 0;
133}
134
135static int null_set_queue_mode(const char *str, const struct kernel_param *kp)
136{
2984c868 137 return null_param_store_val(str, &g_queue_mode, NULL_Q_BIO, NULL_Q_MQ);
709c8667
MB		 138}
139
9c27847d 140static const struct kernel_param_ops null_queue_mode_param_ops = {
709c8667
MB		 141 .set = null_set_queue_mode,
142 .get = param_get_int,
143};
144
5657a819 145device_param_cb(queue_mode, &null_queue_mode_param_ops, &g_queue_mode, 0444);
54ae81cd 146MODULE_PARM_DESC(queue_mode, "Block interface to use (0=bio,1=rq,2=multiqueue)");
f2298c04 147
2984c868 148static int g_gb = 250;
5657a819 149module_param_named(gb, g_gb, int, 0444);
f2298c04
JA		 150MODULE_PARM_DESC(gb, "Size in GB");
151
2984c868 152static int g_bs = 512;
5657a819 153module_param_named(bs, g_bs, int, 0444);
f2298c04
JA		 154MODULE_PARM_DESC(bs, "Block size (in bytes)");
155
ea17fd35
DLM		 156static int g_max_sectors;
157module_param_named(max_sectors, g_max_sectors, int, 0444);
158MODULE_PARM_DESC(max_sectors, "Maximum size of a command (in 512B sectors)");
159
f7c4ce89 160static unsigned int nr_devices = 1;
701dfc42 161module_param(nr_devices, uint, 0444);
f2298c04
JA		 162MODULE_PARM_DESC(nr_devices, "Number of devices to register");
163
2984c868 164static bool g_blocking;
5657a819 165module_param_named(blocking, g_blocking, bool, 0444);
db5bcf87
JA		 166MODULE_PARM_DESC(blocking, "Register as a blocking blk-mq driver device");
167
82f402fe 168static bool shared_tags;
5657a819 169module_param(shared_tags, bool, 0444);
82f402fe
JA		 170MODULE_PARM_DESC(shared_tags, "Share tag set between devices for blk-mq");
171
0905053b
JG		 172static bool g_shared_tag_bitmap;
173module_param_named(shared_tag_bitmap, g_shared_tag_bitmap, bool, 0444);
174MODULE_PARM_DESC(shared_tag_bitmap, "Use shared tag bitmap for all submission queues for blk-mq");
175
2984c868 176static int g_irqmode = NULL_IRQ_SOFTIRQ;
709c8667
MB		 177
178static int null_set_irqmode(const char *str, const struct kernel_param *kp)
179{
2984c868 180 return null_param_store_val(str, &g_irqmode, NULL_IRQ_NONE,
709c8667
MB		 181 NULL_IRQ_TIMER);
182}
183
9c27847d 184static const struct kernel_param_ops null_irqmode_param_ops = {
709c8667
MB		 185 .set = null_set_irqmode,
186 .get = param_get_int,
187};
188
5657a819 189device_param_cb(irqmode, &null_irqmode_param_ops, &g_irqmode, 0444);
f2298c04
JA		 190MODULE_PARM_DESC(irqmode, "IRQ completion handler. 0-none, 1-softirq, 2-timer");
191
2984c868 192static unsigned long g_completion_nsec = 10000;
5657a819 193module_param_named(completion_nsec, g_completion_nsec, ulong, 0444);
f2298c04
JA		 194MODULE_PARM_DESC(completion_nsec, "Time in ns to complete a request in hardware. Default: 10,000ns");
195
2984c868 196static int g_hw_queue_depth = 64;
5657a819 197module_param_named(hw_queue_depth, g_hw_queue_depth, int, 0444);
f2298c04
JA		 198MODULE_PARM_DESC(hw_queue_depth, "Queue depth for each hardware queue. Default: 64");
199
2984c868 200static bool g_use_per_node_hctx;
5657a819 201module_param_named(use_per_node_hctx, g_use_per_node_hctx, bool, 0444);
20005244 202MODULE_PARM_DESC(use_per_node_hctx, "Use per-node allocation for hardware context queues. Default: false");
f2298c04 203
058efe00
VF		 204static bool g_memory_backed;
205module_param_named(memory_backed, g_memory_backed, bool, 0444);
206MODULE_PARM_DESC(memory_backed, "Create a memory-backed block device. Default: false");
207
208static bool g_discard;
209module_param_named(discard, g_discard, bool, 0444);
210MODULE_PARM_DESC(discard, "Support discard operations (requires memory-backed null_blk device). Default: false");
211
212static unsigned long g_cache_size;
213module_param_named(cache_size, g_cache_size, ulong, 0444);
214MODULE_PARM_DESC(mbps, "Cache size in MiB for memory-backed device. Default: 0 (none)");
215
216static unsigned int g_mbps;
217module_param_named(mbps, g_mbps, uint, 0444);
218MODULE_PARM_DESC(mbps, "Limit maximum bandwidth (in MiB/s). Default: 0 (no limit)");
219
ca4b2a01
MB		 220static bool g_zoned;
221module_param_named(zoned, g_zoned, bool, S_IRUGO);
222MODULE_PARM_DESC(zoned, "Make device as a host-managed zoned block device. Default: false");
223
224static unsigned long g_zone_size = 256;
225module_param_named(zone_size, g_zone_size, ulong, S_IRUGO);
226MODULE_PARM_DESC(zone_size, "Zone size in MB when block device is zoned. Must be power-of-two: Default: 256");
227
089565fb
AR		 228static unsigned long g_zone_capacity;
229module_param_named(zone_capacity, g_zone_capacity, ulong, 0444);
230MODULE_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");
231
ea2c18e1
MS		 232static unsigned int g_zone_nr_conv;
233module_param_named(zone_nr_conv, g_zone_nr_conv, uint, 0444);
234MODULE_PARM_DESC(zone_nr_conv, "Number of conventional zones when block device is zoned. Default: 0");
235
dc4d137e
NC		 236static unsigned int g_zone_max_open;
237module_param_named(zone_max_open, g_zone_max_open, uint, 0444);
238MODULE_PARM_DESC(zone_max_open, "Maximum number of open zones when block device is zoned. Default: 0 (no limit)");
239
240static unsigned int g_zone_max_active;
241module_param_named(zone_max_active, g_zone_max_active, uint, 0444);
242MODULE_PARM_DESC(zone_max_active, "Maximum number of active zones when block device is zoned. Default: 0 (no limit)");
243
3bf2bd20
SL		 244static struct nullb_device *null_alloc_dev(void);
245static void null_free_dev(struct nullb_device *dev);
cedcafad
SL		 246static void null_del_dev(struct nullb *nullb);
247static int null_add_dev(struct nullb_device *dev);
49c3b926 248static struct nullb *null_find_dev_by_name(const char *name);
deb78b41 249static void null_free_device_storage(struct nullb_device *dev, bool is_cache);
3bf2bd20
SL		 250
251static inline struct nullb_device *to_nullb_device(struct config_item *item)
252{
bb4c19e0 253 return item ? container_of(to_config_group(item), struct nullb_device, group) : NULL;
3bf2bd20
SL		 254}
255
256static inline ssize_t nullb_device_uint_attr_show(unsigned int val, char *page)
257{
258 return snprintf(page, PAGE_SIZE, "%u\n", val);
259}
260
261static inline ssize_t nullb_device_ulong_attr_show(unsigned long val,
262 char *page)
263{
264 return snprintf(page, PAGE_SIZE, "%lu\n", val);
265}
266
267static inline ssize_t nullb_device_bool_attr_show(bool val, char *page)
268{
269 return snprintf(page, PAGE_SIZE, "%u\n", val);
270}
271
272static ssize_t nullb_device_uint_attr_store(unsigned int *val,
273 const char *page, size_t count)
274{
275 unsigned int tmp;
276 int result;
277
278 result = kstrtouint(page, 0, &tmp);
45919fbf 279 if (result < 0)
3bf2bd20
SL		 280 return result;
281
282 *val = tmp;
283 return count;
284}
285
286static ssize_t nullb_device_ulong_attr_store(unsigned long *val,
287 const char *page, size_t count)
288{
289 int result;
290 unsigned long tmp;
291
292 result = kstrtoul(page, 0, &tmp);
45919fbf 293 if (result < 0)
3bf2bd20
SL		 294 return result;
295
296 *val = tmp;
297 return count;
298}
299
300static ssize_t nullb_device_bool_attr_store(bool *val, const char *page,
301 size_t count)
302{
303 bool tmp;
304 int result;
305
306 result = kstrtobool(page, &tmp);
45919fbf 307 if (result < 0)
3bf2bd20
SL		 308 return result;
309
310 *val = tmp;
311 return count;
312}
313
314/* The following macro should only be used with TYPE = {uint, ulong, bool}. */
ca0a95a6
AM		 315#define NULLB_DEVICE_ATTR(NAME, TYPE, APPLY) \
316static ssize_t \
317nullb_device_##NAME##_show(struct config_item *item, char *page) \
318{ \
319 return nullb_device_##TYPE##_attr_show( \
320 to_nullb_device(item)->NAME, page); \
321} \
322static ssize_t \
323nullb_device_##NAME##_store(struct config_item *item, const char *page, \
324 size_t count) \
325{ \
326 int (*apply_fn)(struct nullb_device *dev, TYPE new_value) = APPLY;\
327 struct nullb_device *dev = to_nullb_device(item); \
b9853b4d 328 TYPE new_value = 0; \
ca0a95a6
AM		 329 int ret; \
330 \
331 ret = nullb_device_##TYPE##_attr_store(&new_value, page, count);\
332 if (ret < 0) \
333 return ret; \
334 if (apply_fn) \
335 ret = apply_fn(dev, new_value); \
336 else if (test_bit(NULLB_DEV_FL_CONFIGURED, &dev->flags)) \
337 ret = -EBUSY; \
338 if (ret < 0) \
339 return ret; \
340 dev->NAME = new_value; \
341 return count; \
342} \
3bf2bd20
SL		 343CONFIGFS_ATTR(nullb_device_, NAME);
344
15dfc662
SK		 345static int nullb_update_nr_hw_queues(struct nullb_device *dev,
346 unsigned int submit_queues,
347 unsigned int poll_queues)
348
45919fbf 349{
45919fbf 350 struct blk_mq_tag_set *set;
15dfc662 351 int ret, nr_hw_queues;
45919fbf 352
15dfc662 353 if (!dev->nullb)
45919fbf
BVA		 354 return 0;
355
15dfc662 356 /*
2bfdbe8b 357 * Make sure at least one submit queue exists.
15dfc662 358 */
2bfdbe8b 359 if (!submit_queues)
15dfc662
SK		 360 return -EINVAL;
361
78b10be2
BVA		 362 /*
363 * Make sure that null_init_hctx() does not access nullb->queues[] past
364 * the end of that array.
365 */
15dfc662 366 if (submit_queues > nr_cpu_ids || poll_queues > g_poll_queues)
78b10be2 367 return -EINVAL;
15dfc662
SK		 368
369 /*
370 * Keep previous and new queue numbers in nullb_device for reference in
371 * the call back function null_map_queues().
372 */
373 dev->prev_submit_queues = dev->submit_queues;
374 dev->prev_poll_queues = dev->poll_queues;
375 dev->submit_queues = submit_queues;
376 dev->poll_queues = poll_queues;
377
378 set = dev->nullb->tag_set;
379 nr_hw_queues = submit_queues + poll_queues;
380 blk_mq_update_nr_hw_queues(set, nr_hw_queues);
381 ret = set->nr_hw_queues == nr_hw_queues ? 0 : -ENOMEM;
382
383 if (ret) {
384 /* on error, revert the queue numbers */
385 dev->submit_queues = dev->prev_submit_queues;
386 dev->poll_queues = dev->prev_poll_queues;
387 }
388
389 return ret;
390}
391
392static int nullb_apply_submit_queues(struct nullb_device *dev,
393 unsigned int submit_queues)
394{
395 return nullb_update_nr_hw_queues(dev, submit_queues, dev->poll_queues);
396}
397
398static int nullb_apply_poll_queues(struct nullb_device *dev,
399 unsigned int poll_queues)
400{
401 return nullb_update_nr_hw_queues(dev, dev->submit_queues, poll_queues);
45919fbf
BVA		 402}
403
404NULLB_DEVICE_ATTR(size, ulong, NULL);
405NULLB_DEVICE_ATTR(completion_nsec, ulong, NULL);
406NULLB_DEVICE_ATTR(submit_queues, uint, nullb_apply_submit_queues);
15dfc662 407NULLB_DEVICE_ATTR(poll_queues, uint, nullb_apply_poll_queues);
45919fbf
BVA		 408NULLB_DEVICE_ATTR(home_node, uint, NULL);
409NULLB_DEVICE_ATTR(queue_mode, uint, NULL);
410NULLB_DEVICE_ATTR(blocksize, uint, NULL);
ea17fd35 411NULLB_DEVICE_ATTR(max_sectors, uint, NULL);
45919fbf
BVA		 412NULLB_DEVICE_ATTR(irqmode, uint, NULL);
413NULLB_DEVICE_ATTR(hw_queue_depth, uint, NULL);
414NULLB_DEVICE_ATTR(index, uint, NULL);
415NULLB_DEVICE_ATTR(blocking, bool, NULL);
416NULLB_DEVICE_ATTR(use_per_node_hctx, bool, NULL);
417NULLB_DEVICE_ATTR(memory_backed, bool, NULL);
418NULLB_DEVICE_ATTR(discard, bool, NULL);
419NULLB_DEVICE_ATTR(mbps, uint, NULL);
420NULLB_DEVICE_ATTR(cache_size, ulong, NULL);
421NULLB_DEVICE_ATTR(zoned, bool, NULL);
422NULLB_DEVICE_ATTR(zone_size, ulong, NULL);
089565fb 423NULLB_DEVICE_ATTR(zone_capacity, ulong, NULL);
45919fbf 424NULLB_DEVICE_ATTR(zone_nr_conv, uint, NULL);
dc4d137e
NC		 425NULLB_DEVICE_ATTR(zone_max_open, uint, NULL);
426NULLB_DEVICE_ATTR(zone_max_active, uint, NULL);
cee1b215 427NULLB_DEVICE_ATTR(virt_boundary, bool, NULL);
7012eef5
VF		 428NULLB_DEVICE_ATTR(no_sched, bool, NULL);
429NULLB_DEVICE_ATTR(shared_tag_bitmap, bool, NULL);
3bf2bd20 430
cedcafad
SL		 431static ssize_t nullb_device_power_show(struct config_item *item, char *page)
432{
433 return nullb_device_bool_attr_show(to_nullb_device(item)->power, page);
434}
435
436static ssize_t nullb_device_power_store(struct config_item *item,
437 const char *page, size_t count)
438{
439 struct nullb_device *dev = to_nullb_device(item);
440 bool newp = false;
441 ssize_t ret;
442
443 ret = nullb_device_bool_attr_store(&newp, page, count);
444 if (ret < 0)
445 return ret;
446
447 if (!dev->power && newp) {
448 if (test_and_set_bit(NULLB_DEV_FL_UP, &dev->flags))
449 return count;
a75110c3
CK		 450 ret = null_add_dev(dev);
451 if (ret) {
cedcafad 452 clear_bit(NULLB_DEV_FL_UP, &dev->flags);
a75110c3 453 return ret;
cedcafad
SL		 454 }
455
456 set_bit(NULLB_DEV_FL_CONFIGURED, &dev->flags);
457 dev->power = newp;
b3c30512 458 } else if (dev->power && !newp) {
7602843f
BL		 459 if (test_and_clear_bit(NULLB_DEV_FL_UP, &dev->flags)) {
460 mutex_lock(&lock);
461 dev->power = newp;
462 null_del_dev(dev->nullb);
463 mutex_unlock(&lock);
464 }
00a8cdb8 465 clear_bit(NULLB_DEV_FL_CONFIGURED, &dev->flags);
cedcafad
SL		 466 }
467
468 return count;
469}
470
471CONFIGFS_ATTR(nullb_device_, power);
472
2f54a613
SL		 473static ssize_t nullb_device_badblocks_show(struct config_item *item, char *page)
474{
475 struct nullb_device *t_dev = to_nullb_device(item);
476
477 return badblocks_show(&t_dev->badblocks, page, 0);
478}
479
480static ssize_t nullb_device_badblocks_store(struct config_item *item,
481 const char *page, size_t count)
482{
483 struct nullb_device *t_dev = to_nullb_device(item);
484 char *orig, *buf, *tmp;
485 u64 start, end;
486 int ret;
487
488 orig = kstrndup(page, count, GFP_KERNEL);
489 if (!orig)
490 return -ENOMEM;
491
492 buf = strstrip(orig);
493
494 ret = -EINVAL;
495 if (buf[0] != '+' && buf[0] != '-')
496 goto out;
497 tmp = strchr(&buf[1], '-');
498 if (!tmp)
499 goto out;
500 *tmp = '\0';
501 ret = kstrtoull(buf + 1, 0, &start);
502 if (ret)
503 goto out;
504 ret = kstrtoull(tmp + 1, 0, &end);
505 if (ret)
506 goto out;
507 ret = -EINVAL;
508 if (start > end)
509 goto out;
510 /* enable badblocks */
511 cmpxchg(&t_dev->badblocks.shift, -1, 0);
512 if (buf[0] == '+')
513 ret = badblocks_set(&t_dev->badblocks, start,
514 end - start + 1, 1);
515 else
516 ret = badblocks_clear(&t_dev->badblocks, start,
517 end - start + 1);
518 if (ret == 0)
519 ret = count;
520out:
521 kfree(orig);
522 return ret;
523}
524CONFIGFS_ATTR(nullb_device_, badblocks);
525
d3a57388
SK		 526static ssize_t nullb_device_zone_readonly_store(struct config_item *item,
527 const char *page, size_t count)
528{
529 struct nullb_device *dev = to_nullb_device(item);
530
531 return zone_cond_store(dev, page, count, BLK_ZONE_COND_READONLY);
532}
533CONFIGFS_ATTR_WO(nullb_device_, zone_readonly);
534
535static ssize_t nullb_device_zone_offline_store(struct config_item *item,
536 const char *page, size_t count)
537{
538 struct nullb_device *dev = to_nullb_device(item);
539
540 return zone_cond_store(dev, page, count, BLK_ZONE_COND_OFFLINE);
541}
542CONFIGFS_ATTR_WO(nullb_device_, zone_offline);
543
3bf2bd20
SL		 544static struct configfs_attribute *nullb_device_attrs[] = {
545 &nullb_device_attr_size,
546 &nullb_device_attr_completion_nsec,
547 &nullb_device_attr_submit_queues,
0a593fbb 548 &nullb_device_attr_poll_queues,
3bf2bd20
SL		 549 &nullb_device_attr_home_node,
550 &nullb_device_attr_queue_mode,
551 &nullb_device_attr_blocksize,
ea17fd35 552 &nullb_device_attr_max_sectors,
3bf2bd20
SL		 553 &nullb_device_attr_irqmode,
554 &nullb_device_attr_hw_queue_depth,
cedcafad 555 &nullb_device_attr_index,
3bf2bd20
SL		 556 &nullb_device_attr_blocking,
557 &nullb_device_attr_use_per_node_hctx,
cedcafad 558 &nullb_device_attr_power,
5bcd0e0c 559 &nullb_device_attr_memory_backed,
306eb6b4 560 &nullb_device_attr_discard,
eff2c4f1 561 &nullb_device_attr_mbps,
deb78b41 562 &nullb_device_attr_cache_size,
2f54a613 563 &nullb_device_attr_badblocks,
ca4b2a01
MB		 564 &nullb_device_attr_zoned,
565 &nullb_device_attr_zone_size,
089565fb 566 &nullb_device_attr_zone_capacity,
ea2c18e1 567 &nullb_device_attr_zone_nr_conv,
dc4d137e
NC		 568 &nullb_device_attr_zone_max_open,
569 &nullb_device_attr_zone_max_active,
d3a57388
SK		 570 &nullb_device_attr_zone_readonly,
571 &nullb_device_attr_zone_offline,
cee1b215 572 &nullb_device_attr_virt_boundary,
7012eef5
VF		 573 &nullb_device_attr_no_sched,
574 &nullb_device_attr_shared_tag_bitmap,
3bf2bd20
SL		 575 NULL,
576};
577
578static void nullb_device_release(struct config_item *item)
579{
5bcd0e0c
SL		 580 struct nullb_device *dev = to_nullb_device(item);
581
deb78b41 582 null_free_device_storage(dev, false);
5bcd0e0c 583 null_free_dev(dev);
3bf2bd20
SL		 584}
585
586static struct configfs_item_operations nullb_device_ops = {
587 .release = nullb_device_release,
588};
589
e1919dff 590static const struct config_item_type nullb_device_type = {
3bf2bd20
SL		 591 .ct_item_ops = &nullb_device_ops,
592 .ct_attrs = nullb_device_attrs,
593 .ct_owner = THIS_MODULE,
594};
595
bb4c19e0
AM		 596#ifdef CONFIG_BLK_DEV_NULL_BLK_FAULT_INJECTION
597
598static void nullb_add_fault_config(struct nullb_device *dev)
599{
600 fault_config_init(&dev->timeout_config, "timeout_inject");
601 fault_config_init(&dev->requeue_config, "requeue_inject");
602 fault_config_init(&dev->init_hctx_fault_config, "init_hctx_fault_inject");
603
604 configfs_add_default_group(&dev->timeout_config.group, &dev->group);
605 configfs_add_default_group(&dev->requeue_config.group, &dev->group);
606 configfs_add_default_group(&dev->init_hctx_fault_config.group, &dev->group);
607}
608
609#else
610
611static void nullb_add_fault_config(struct nullb_device *dev)
612{
613}
614
615#endif
616
3bf2bd20 617static struct
bb4c19e0 618config_group *nullb_group_make_group(struct config_group *group, const char *name)
3bf2bd20
SL		 619{
620 struct nullb_device *dev;
621
49c3b926
DLM		 622 if (null_find_dev_by_name(name))
623 return ERR_PTR(-EEXIST);
624
3bf2bd20
SL		 625 dev = null_alloc_dev();
626 if (!dev)
627 return ERR_PTR(-ENOMEM);
628
bb4c19e0
AM		 629 config_group_init_type_name(&dev->group, name, &nullb_device_type);
630 nullb_add_fault_config(dev);
3bf2bd20 631
bb4c19e0 632 return &dev->group;
3bf2bd20
SL		 633}
634
635static void
636nullb_group_drop_item(struct config_group *group, struct config_item *item)
637{
cedcafad
SL		 638 struct nullb_device *dev = to_nullb_device(item);
639
640 if (test_and_clear_bit(NULLB_DEV_FL_UP, &dev->flags)) {
641 mutex_lock(&lock);
642 dev->power = false;
643 null_del_dev(dev->nullb);
644 mutex_unlock(&lock);
645 }
646
3bf2bd20
SL		 647 config_item_put(item);
648}
649
650static ssize_t memb_group_features_show(struct config_item *item, char *page)
651{
089565fb 652 return snprintf(page, PAGE_SIZE,
7012eef5
VF		 653 "badblocks,blocking,blocksize,cache_size,"
654 "completion_nsec,discard,home_node,hw_queue_depth,"
655 "irqmode,max_sectors,mbps,memory_backed,no_sched,"
656 "poll_queues,power,queue_mode,shared_tag_bitmap,size,"
657 "submit_queues,use_per_node_hctx,virt_boundary,zoned,"
658 "zone_capacity,zone_max_active,zone_max_open,"
d3a57388 659 "zone_nr_conv,zone_offline,zone_readonly,zone_size\n");
3bf2bd20
SL		 660}
661
662CONFIGFS_ATTR_RO(memb_group_, features);
663
664static struct configfs_attribute *nullb_group_attrs[] = {
665 &memb_group_attr_features,
666 NULL,
667};
668
669static struct configfs_group_operations nullb_group_ops = {
bb4c19e0 670 .make_group = nullb_group_make_group,
3bf2bd20
SL		 671 .drop_item = nullb_group_drop_item,
672};
673
e1919dff 674static const struct config_item_type nullb_group_type = {
3bf2bd20
SL		 675 .ct_group_ops = &nullb_group_ops,
676 .ct_attrs = nullb_group_attrs,
677 .ct_owner = THIS_MODULE,
678};
679
680static struct configfs_subsystem nullb_subsys = {
681 .su_group = {
682 .cg_item = {
683 .ci_namebuf = "nullb",
684 .ci_type = &nullb_group_type,
685 },
686 },
687};
688
deb78b41
SL		 689static inline int null_cache_active(struct nullb *nullb)
690{
691 return test_bit(NULLB_DEV_FL_CACHE, &nullb->dev->flags);
692}
693
2984c868
SL		 694static struct nullb_device *null_alloc_dev(void)
695{
696 struct nullb_device *dev;
697
698 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
699 if (!dev)
700 return NULL;
bb4c19e0
AM		 701
702#ifdef CONFIG_BLK_DEV_NULL_BLK_FAULT_INJECTION
703 dev->timeout_config.attr = null_timeout_attr;
704 dev->requeue_config.attr = null_requeue_attr;
705 dev->init_hctx_fault_config.attr = null_init_hctx_attr;
706#endif
707
5bcd0e0c 708 INIT_RADIX_TREE(&dev->data, GFP_ATOMIC);
deb78b41 709 INIT_RADIX_TREE(&dev->cache, GFP_ATOMIC);
2f54a613
SL		 710 if (badblocks_init(&dev->badblocks, 0)) {
711 kfree(dev);
712 return NULL;
713 }
714
2984c868
SL		 715 dev->size = g_gb * 1024;
716 dev->completion_nsec = g_completion_nsec;
717 dev->submit_queues = g_submit_queues;
15dfc662 718 dev->prev_submit_queues = g_submit_queues;
0a593fbb 719 dev->poll_queues = g_poll_queues;
15dfc662 720 dev->prev_poll_queues = g_poll_queues;
2984c868
SL		 721 dev->home_node = g_home_node;
722 dev->queue_mode = g_queue_mode;
723 dev->blocksize = g_bs;
ea17fd35 724 dev->max_sectors = g_max_sectors;
2984c868
SL		 725 dev->irqmode = g_irqmode;
726 dev->hw_queue_depth = g_hw_queue_depth;
2984c868 727 dev->blocking = g_blocking;
058efe00
VF		 728 dev->memory_backed = g_memory_backed;
729 dev->discard = g_discard;
730 dev->cache_size = g_cache_size;
731 dev->mbps = g_mbps;
2984c868 732 dev->use_per_node_hctx = g_use_per_node_hctx;
ca4b2a01
MB		 733 dev->zoned = g_zoned;
734 dev->zone_size = g_zone_size;
089565fb 735 dev->zone_capacity = g_zone_capacity;
ea2c18e1 736 dev->zone_nr_conv = g_zone_nr_conv;
dc4d137e
NC		 737 dev->zone_max_open = g_zone_max_open;
738 dev->zone_max_active = g_zone_max_active;
cee1b215 739 dev->virt_boundary = g_virt_boundary;
7012eef5
VF		 740 dev->no_sched = g_no_sched;
741 dev->shared_tag_bitmap = g_shared_tag_bitmap;
2984c868
SL		 742 return dev;
743}
744
745static void null_free_dev(struct nullb_device *dev)
746{
1addb798
DD		 747 if (!dev)
748 return;
749
d205bde7 750 null_free_zoned_dev(dev);
1addb798 751 badblocks_exit(&dev->badblocks);
2984c868
SL		 752 kfree(dev);
753}
754
f2298c04
JA		 755static void put_tag(struct nullb_queue *nq, unsigned int tag)
756{
757 clear_bit_unlock(tag, nq->tag_map);
758
759 if (waitqueue_active(&nq->wait))
760 wake_up(&nq->wait);
761}
762
763static unsigned int get_tag(struct nullb_queue *nq)
764{
765 unsigned int tag;
766
767 do {
768 tag = find_first_zero_bit(nq->tag_map, nq->queue_depth);
769 if (tag >= nq->queue_depth)
770 return -1U;
771 } while (test_and_set_bit_lock(tag, nq->tag_map));
772
773 return tag;
774}
775
776static void free_cmd(struct nullb_cmd *cmd)
777{
778 put_tag(cmd->nq, cmd->tag);
779}
780
3c395a96
PV		 781static enum hrtimer_restart null_cmd_timer_expired(struct hrtimer *timer);
782
f2298c04
JA		 783static struct nullb_cmd *__alloc_cmd(struct nullb_queue *nq)
784{
785 struct nullb_cmd *cmd;
786 unsigned int tag;
787
788 tag = get_tag(nq);
789 if (tag != -1U) {
790 cmd = &nq->cmds[tag];
791 cmd->tag = tag;
ff770422 792 cmd->error = BLK_STS_OK;
f2298c04 793 cmd->nq = nq;
2984c868 794 if (nq->dev->irqmode == NULL_IRQ_TIMER) {
3c395a96
PV		 795 hrtimer_init(&cmd->timer, CLOCK_MONOTONIC,
796 HRTIMER_MODE_REL);
797 cmd->timer.function = null_cmd_timer_expired;
798 }
f2298c04
JA		 799 return cmd;
800 }
801
802 return NULL;
803}
804
3d3472f3 805static struct nullb_cmd *alloc_cmd(struct nullb_queue *nq, struct bio *bio)
f2298c04
JA		 806{
807 struct nullb_cmd *cmd;
808 DEFINE_WAIT(wait);
809
f2298c04 810 do {
3d3472f3
CK		 811 /*
812 * This avoids multiple return statements, multiple calls to
813 * __alloc_cmd() and a fast path call to prepare_to_wait().
814 */
f2298c04 815 cmd = __alloc_cmd(nq);
3d3472f3
CK		 816 if (cmd) {
817 cmd->bio = bio;
818 return cmd;
819 }
820 prepare_to_wait(&nq->wait, &wait, TASK_UNINTERRUPTIBLE);
f2298c04 821 io_schedule();
3d3472f3 822 finish_wait(&nq->wait, &wait);
f2298c04 823 } while (1);
f2298c04
JA		 824}
825
826static void end_cmd(struct nullb_cmd *cmd)
827{
2984c868 828 int queue_mode = cmd->nq->dev->queue_mode;
cf8ecc5a 829
ce2c350b
CH		 830 switch (queue_mode) {
831 case NULL_Q_MQ:
5bcd0e0c 832 blk_mq_end_request(cmd->rq, cmd->error);
ce2c350b 833 return;
ce2c350b 834 case NULL_Q_BIO:
5bcd0e0c 835 cmd->bio->bi_status = cmd->error;
4246a0b6 836 bio_endio(cmd->bio);
48cc661e 837 break;
ce2c350b 838 }
f2298c04 839
48cc661e 840 free_cmd(cmd);
cf8ecc5a
AA		 841}
842
843static enum hrtimer_restart null_cmd_timer_expired(struct hrtimer *timer)
844{
845 end_cmd(container_of(timer, struct nullb_cmd, timer));
f2298c04
JA		 846
847 return HRTIMER_NORESTART;
848}
849
850static void null_cmd_end_timer(struct nullb_cmd *cmd)
851{
2984c868 852 ktime_t kt = cmd->nq->dev->completion_nsec;
f2298c04 853
3c395a96 854 hrtimer_start(&cmd->timer, kt, HRTIMER_MODE_REL);
f2298c04
JA		 855}
856
49f66136 857static void null_complete_rq(struct request *rq)
f2298c04 858{
49f66136 859 end_cmd(blk_mq_rq_to_pdu(rq));
f2298c04
JA		 860}
861
c90b6b50 862static struct nullb_page *null_alloc_page(void)
5bcd0e0c
SL		 863{
864 struct nullb_page *t_page;
865
c90b6b50 866 t_page = kmalloc(sizeof(struct nullb_page), GFP_NOIO);
5bcd0e0c 867 if (!t_page)
df00b1d2 868 return NULL;
5bcd0e0c 869
c90b6b50 870 t_page->page = alloc_pages(GFP_NOIO, 0);
df00b1d2
CK		 871 if (!t_page->page) {
872 kfree(t_page);
873 return NULL;
874 }
5bcd0e0c 875
66231ad3 876 memset(t_page->bitmap, 0, sizeof(t_page->bitmap));
5bcd0e0c 877 return t_page;
5bcd0e0c
SL		 878}
879
880static void null_free_page(struct nullb_page *t_page)
881{
66231ad3
ML		 882 __set_bit(NULLB_PAGE_FREE, t_page->bitmap);
883 if (test_bit(NULLB_PAGE_LOCK, t_page->bitmap))
deb78b41 884 return;
5bcd0e0c
SL		 885 __free_page(t_page->page);
886 kfree(t_page);
887}
888
66231ad3
ML		 889static bool null_page_empty(struct nullb_page *page)
890{
891 int size = MAP_SZ - 2;
892
893 return find_first_bit(page->bitmap, size) == size;
894}
895
deb78b41
SL		 896static void null_free_sector(struct nullb *nullb, sector_t sector,
897 bool is_cache)
5bcd0e0c
SL		 898{
899 unsigned int sector_bit;
900 u64 idx;
901 struct nullb_page *t_page, *ret;
902 struct radix_tree_root *root;
903
deb78b41 904 root = is_cache ? &nullb->dev->cache : &nullb->dev->data;
5bcd0e0c
SL		 905 idx = sector >> PAGE_SECTORS_SHIFT;
906 sector_bit = (sector & SECTOR_MASK);
907
908 t_page = radix_tree_lookup(root, idx);
909 if (t_page) {
66231ad3 910 __clear_bit(sector_bit, t_page->bitmap);
5bcd0e0c 911
66231ad3 912 if (null_page_empty(t_page)) {
5bcd0e0c
SL		 913 ret = radix_tree_delete_item(root, idx, t_page);
914 WARN_ON(ret != t_page);
915 null_free_page(ret);
deb78b41
SL		 916 if (is_cache)
917 nullb->dev->curr_cache -= PAGE_SIZE;
5bcd0e0c
SL		 918 }
919 }
920}
921
922static struct nullb_page *null_radix_tree_insert(struct nullb *nullb, u64 idx,
deb78b41 923 struct nullb_page *t_page, bool is_cache)
5bcd0e0c
SL		 924{
925 struct radix_tree_root *root;
926
deb78b41 927 root = is_cache ? &nullb->dev->cache : &nullb->dev->data;
5bcd0e0c
SL		 928
929 if (radix_tree_insert(root, idx, t_page)) {
930 null_free_page(t_page);
931 t_page = radix_tree_lookup(root, idx);
932 WARN_ON(!t_page || t_page->page->index != idx);
deb78b41
SL		 933 } else if (is_cache)
934 nullb->dev->curr_cache += PAGE_SIZE;
5bcd0e0c
SL		 935
936 return t_page;
937}
938
deb78b41 939static void null_free_device_storage(struct nullb_device *dev, bool is_cache)
5bcd0e0c
SL		 940{
941 unsigned long pos = 0;
942 int nr_pages;
943 struct nullb_page *ret, *t_pages[FREE_BATCH];
944 struct radix_tree_root *root;
945
deb78b41 946 root = is_cache ? &dev->cache : &dev->data;
5bcd0e0c
SL		 947
948 do {
949 int i;
950
951 nr_pages = radix_tree_gang_lookup(root,
952 (void **)t_pages, pos, FREE_BATCH);
953
954 for (i = 0; i < nr_pages; i++) {
955 pos = t_pages[i]->page->index;
956 ret = radix_tree_delete_item(root, pos, t_pages[i]);
957 WARN_ON(ret != t_pages[i]);
958 null_free_page(ret);
959 }
960
961 pos++;
962 } while (nr_pages == FREE_BATCH);
deb78b41
SL		 963
964 if (is_cache)
965 dev->curr_cache = 0;
5bcd0e0c
SL		 966}
967
deb78b41
SL		 968static struct nullb_page *__null_lookup_page(struct nullb *nullb,
969 sector_t sector, bool for_write, bool is_cache)
5bcd0e0c
SL		 970{
971 unsigned int sector_bit;
972 u64 idx;
973 struct nullb_page *t_page;
deb78b41 974 struct radix_tree_root *root;
5bcd0e0c
SL		 975
976 idx = sector >> PAGE_SECTORS_SHIFT;
977 sector_bit = (sector & SECTOR_MASK);
978
deb78b41
SL		 979 root = is_cache ? &nullb->dev->cache : &nullb->dev->data;
980 t_page = radix_tree_lookup(root, idx);
5bcd0e0c
SL		 981 WARN_ON(t_page && t_page->page->index != idx);
982
66231ad3 983 if (t_page && (for_write || test_bit(sector_bit, t_page->bitmap)))
5bcd0e0c
SL		 984 return t_page;
985
986 return NULL;
987}
988
deb78b41
SL		 989static struct nullb_page *null_lookup_page(struct nullb *nullb,
990 sector_t sector, bool for_write, bool ignore_cache)
991{
992 struct nullb_page *page = NULL;
993
994 if (!ignore_cache)
995 page = __null_lookup_page(nullb, sector, for_write, true);
996 if (page)
997 return page;
998 return __null_lookup_page(nullb, sector, for_write, false);
999}
1000
5bcd0e0c 1001static struct nullb_page *null_insert_page(struct nullb *nullb,
61884de0
JA		 1002 sector_t sector, bool ignore_cache)
1003 __releases(&nullb->lock)
1004 __acquires(&nullb->lock)
5bcd0e0c
SL		 1005{
1006 u64 idx;
1007 struct nullb_page *t_page;
1008
deb78b41 1009 t_page = null_lookup_page(nullb, sector, true, ignore_cache);
5bcd0e0c
SL		 1010 if (t_page)
1011 return t_page;
1012
1013 spin_unlock_irq(&nullb->lock);
1014
c90b6b50 1015 t_page = null_alloc_page();
5bcd0e0c
SL		 1016 if (!t_page)
1017 goto out_lock;
1018
1019 if (radix_tree_preload(GFP_NOIO))
1020 goto out_freepage;
1021
1022 spin_lock_irq(&nullb->lock);
1023 idx = sector >> PAGE_SECTORS_SHIFT;
1024 t_page->page->index = idx;
deb78b41 1025 t_page = null_radix_tree_insert(nullb, idx, t_page, !ignore_cache);
5bcd0e0c
SL		 1026 radix_tree_preload_end();
1027
1028 return t_page;
1029out_freepage:
1030 null_free_page(t_page);
1031out_lock:
1032 spin_lock_irq(&nullb->lock);
deb78b41
SL		 1033 return null_lookup_page(nullb, sector, true, ignore_cache);
1034}
1035
1036static int null_flush_cache_page(struct nullb *nullb, struct nullb_page *c_page)
1037{
1038 int i;
1039 unsigned int offset;
1040 u64 idx;
1041 struct nullb_page *t_page, *ret;
1042 void *dst, *src;
1043
1044 idx = c_page->page->index;
1045
1046 t_page = null_insert_page(nullb, idx << PAGE_SECTORS_SHIFT, true);
1047
66231ad3
ML		 1048 __clear_bit(NULLB_PAGE_LOCK, c_page->bitmap);
1049 if (test_bit(NULLB_PAGE_FREE, c_page->bitmap)) {
deb78b41 1050 null_free_page(c_page);
66231ad3 1051 if (t_page && null_page_empty(t_page)) {
deb78b41
SL		 1052 ret = radix_tree_delete_item(&nullb->dev->data,
1053 idx, t_page);
1054 null_free_page(t_page);
1055 }
1056 return 0;
1057 }
1058
1059 if (!t_page)
1060 return -ENOMEM;
1061
acc3c879
CK		 1062 src = kmap_local_page(c_page->page);
1063 dst = kmap_local_page(t_page->page);
deb78b41
SL		 1064
1065 for (i = 0; i < PAGE_SECTORS;
1066 i += (nullb->dev->blocksize >> SECTOR_SHIFT)) {
66231ad3 1067 if (test_bit(i, c_page->bitmap)) {
deb78b41
SL		 1068 offset = (i << SECTOR_SHIFT);
1069 memcpy(dst + offset, src + offset,
1070 nullb->dev->blocksize);
66231ad3 1071 __set_bit(i, t_page->bitmap);
deb78b41
SL		 1072 }
1073 }
1074
acc3c879
CK		 1075 kunmap_local(dst);
1076 kunmap_local(src);
deb78b41
SL		 1077
1078 ret = radix_tree_delete_item(&nullb->dev->cache, idx, c_page);
1079 null_free_page(ret);
1080 nullb->dev->curr_cache -= PAGE_SIZE;
1081
1082 return 0;
1083}
1084
1085static int null_make_cache_space(struct nullb *nullb, unsigned long n)
f2298c04 1086{
deb78b41
SL		 1087 int i, err, nr_pages;
1088 struct nullb_page *c_pages[FREE_BATCH];
1089 unsigned long flushed = 0, one_round;
1090
1091again:
1092 if ((nullb->dev->cache_size * 1024 * 1024) >
1093 nullb->dev->curr_cache + n || nullb->dev->curr_cache == 0)
1094 return 0;
1095
1096 nr_pages = radix_tree_gang_lookup(&nullb->dev->cache,
1097 (void **)c_pages, nullb->cache_flush_pos, FREE_BATCH);
1098 /*
1099 * nullb_flush_cache_page could unlock before using the c_pages. To
1100 * avoid race, we don't allow page free
1101 */
1102 for (i = 0; i < nr_pages; i++) {
1103 nullb->cache_flush_pos = c_pages[i]->page->index;
1104 /*
1105 * We found the page which is being flushed to disk by other
1106 * threads
1107 */
66231ad3 1108 if (test_bit(NULLB_PAGE_LOCK, c_pages[i]->bitmap))
deb78b41
SL		 1109 c_pages[i] = NULL;
1110 else
66231ad3 1111 __set_bit(NULLB_PAGE_LOCK, c_pages[i]->bitmap);
deb78b41
SL		 1112 }
1113
1114 one_round = 0;
1115 for (i = 0; i < nr_pages; i++) {
1116 if (c_pages[i] == NULL)
1117 continue;
1118 err = null_flush_cache_page(nullb, c_pages[i]);
1119 if (err)
1120 return err;
1121 one_round++;
1122 }
1123 flushed += one_round << PAGE_SHIFT;
1124
1125 if (n > flushed) {
1126 if (nr_pages == 0)
1127 nullb->cache_flush_pos = 0;
1128 if (one_round == 0) {
1129 /* give other threads a chance */
1130 spin_unlock_irq(&nullb->lock);
1131 spin_lock_irq(&nullb->lock);
1132 }
1133 goto again;
1134 }
1135 return 0;
5bcd0e0c
SL		 1136}
1137
1138static int copy_to_nullb(struct nullb *nullb, struct page *source,
deb78b41 1139 unsigned int off, sector_t sector, size_t n, bool is_fua)
5bcd0e0c
SL		 1140{
1141 size_t temp, count = 0;
1142 unsigned int offset;
1143 struct nullb_page *t_page;
5bcd0e0c
SL		 1144
1145 while (count < n) {
1146 temp = min_t(size_t, nullb->dev->blocksize, n - count);
1147
deb78b41
SL		 1148 if (null_cache_active(nullb) && !is_fua)
1149 null_make_cache_space(nullb, PAGE_SIZE);
1150
5bcd0e0c 1151 offset = (sector & SECTOR_MASK) << SECTOR_SHIFT;
deb78b41
SL		 1152 t_page = null_insert_page(nullb, sector,
1153 !null_cache_active(nullb) || is_fua);
5bcd0e0c
SL		 1154 if (!t_page)
1155 return -ENOSPC;
1156
fbb5615f 1157 memcpy_page(t_page->page, offset, source, off + count, temp);
5bcd0e0c 1158
66231ad3 1159 __set_bit(sector & SECTOR_MASK, t_page->bitmap);
5bcd0e0c 1160
deb78b41
SL		 1161 if (is_fua)
1162 null_free_sector(nullb, sector, true);
1163
5bcd0e0c
SL		 1164 count += temp;
1165 sector += temp >> SECTOR_SHIFT;
1166 }
1167 return 0;
1168}
1169
1170static int copy_from_nullb(struct nullb *nullb, struct page *dest,
1171 unsigned int off, sector_t sector, size_t n)
1172{
1173 size_t temp, count = 0;
1174 unsigned int offset;
1175 struct nullb_page *t_page;
5bcd0e0c
SL		 1176
1177 while (count < n) {
1178 temp = min_t(size_t, nullb->dev->blocksize, n - count);
1179
1180 offset = (sector & SECTOR_MASK) << SECTOR_SHIFT;
deb78b41
SL		 1181 t_page = null_lookup_page(nullb, sector, false,
1182 !null_cache_active(nullb));
5bcd0e0c 1183
fbb5615f
CK		 1184 if (t_page)
1185 memcpy_page(dest, off + count, t_page->page, offset,
1186 temp);
1187 else
1188 zero_user(dest, off + count, temp);
5bcd0e0c
SL		 1189
1190 count += temp;
1191 sector += temp >> SECTOR_SHIFT;
1192 }
1193 return 0;
1194}
1195
dd85b492
AJ		 1196static void nullb_fill_pattern(struct nullb *nullb, struct page *page,
1197 unsigned int len, unsigned int off)
1198{
fbb5615f 1199 memset_page(page, off, 0xff, len);
dd85b492
AJ		 1200}
1201
0ec4d913
DLM		 1202blk_status_t null_handle_discard(struct nullb_device *dev,
1203 sector_t sector, sector_t nr_sectors)
306eb6b4 1204{
49c7089f
DLM		 1205 struct nullb *nullb = dev->nullb;
1206 size_t n = nr_sectors << SECTOR_SHIFT;
306eb6b4
SL		 1207 size_t temp;
1208
1209 spin_lock_irq(&nullb->lock);
1210 while (n > 0) {
49c7089f 1211 temp = min_t(size_t, n, dev->blocksize);
deb78b41
SL		 1212 null_free_sector(nullb, sector, false);
1213 if (null_cache_active(nullb))
1214 null_free_sector(nullb, sector, true);
306eb6b4
SL		 1215 sector += temp >> SECTOR_SHIFT;
1216 n -= temp;
1217 }
1218 spin_unlock_irq(&nullb->lock);
49c7089f
DLM		 1219
1220 return BLK_STS_OK;
306eb6b4
SL		 1221}
1222
deb78b41
SL		 1223static int null_handle_flush(struct nullb *nullb)
1224{
1225 int err;
1226
1227 if (!null_cache_active(nullb))
1228 return 0;
1229
1230 spin_lock_irq(&nullb->lock);
1231 while (true) {
1232 err = null_make_cache_space(nullb,
1233 nullb->dev->cache_size * 1024 * 1024);
1234 if (err || nullb->dev->curr_cache == 0)
1235 break;
1236 }
1237
1238 WARN_ON(!radix_tree_empty(&nullb->dev->cache));
1239 spin_unlock_irq(&nullb->lock);
1240 return err;
1241}
1242
5bcd0e0c 1243static int null_transfer(struct nullb *nullb, struct page *page,
deb78b41
SL		 1244 unsigned int len, unsigned int off, bool is_write, sector_t sector,
1245 bool is_fua)
f2298c04 1246{
dd85b492
AJ		 1247 struct nullb_device *dev = nullb->dev;
1248 unsigned int valid_len = len;
5bcd0e0c
SL		 1249 int err = 0;
1250
1251 if (!is_write) {
dd85b492
AJ		 1252 if (dev->zoned)
1253 valid_len = null_zone_valid_read_len(nullb,
1254 sector, len);
1255
1256 if (valid_len) {
1257 err = copy_from_nullb(nullb, page, off,
1258 sector, valid_len);
1259 off += valid_len;
1260 len -= valid_len;
1261 }
1262
1263 if (len)
1264 nullb_fill_pattern(nullb, page, len, off);
5bcd0e0c
SL		 1265 flush_dcache_page(page);
1266 } else {
1267 flush_dcache_page(page);
deb78b41 1268 err = copy_to_nullb(nullb, page, off, sector, len, is_fua);
5bcd0e0c
SL		 1269 }
1270
1271 return err;
1272}
1273
1274static int null_handle_rq(struct nullb_cmd *cmd)
1275{
1276 struct request *rq = cmd->rq;
1277 struct nullb *nullb = cmd->nq->dev->nullb;
1278 int err;
1279 unsigned int len;
49c7089f 1280 sector_t sector = blk_rq_pos(rq);
5bcd0e0c
SL		 1281 struct req_iterator iter;
1282 struct bio_vec bvec;
1283
5bcd0e0c
SL		 1284 spin_lock_irq(&nullb->lock);
1285 rq_for_each_segment(bvec, rq, iter) {
1286 len = bvec.bv_len;
1287 err = null_transfer(nullb, bvec.bv_page, len, bvec.bv_offset,
deb78b41 1288 op_is_write(req_op(rq)), sector,
2d62e6b0 1289 rq->cmd_flags & REQ_FUA);
5bcd0e0c
SL		 1290 if (err) {
1291 spin_unlock_irq(&nullb->lock);
1292 return err;
1293 }
1294 sector += len >> SECTOR_SHIFT;
1295 }
1296 spin_unlock_irq(&nullb->lock);
1297
1298 return 0;
1299}
1300
1301static int null_handle_bio(struct nullb_cmd *cmd)
1302{
1303 struct bio *bio = cmd->bio;
1304 struct nullb *nullb = cmd->nq->dev->nullb;
1305 int err;
1306 unsigned int len;
49c7089f 1307 sector_t sector = bio->bi_iter.bi_sector;
5bcd0e0c
SL		 1308 struct bio_vec bvec;
1309 struct bvec_iter iter;
1310
5bcd0e0c
SL		 1311 spin_lock_irq(&nullb->lock);
1312 bio_for_each_segment(bvec, bio, iter) {
1313 len = bvec.bv_len;
1314 err = null_transfer(nullb, bvec.bv_page, len, bvec.bv_offset,
deb78b41 1315 op_is_write(bio_op(bio)), sector,
bf7c7a04 1316 bio->bi_opf & REQ_FUA);
5bcd0e0c
SL		 1317 if (err) {
1318 spin_unlock_irq(&nullb->lock);
1319 return err;
1320 }
1321 sector += len >> SECTOR_SHIFT;
1322 }
1323 spin_unlock_irq(&nullb->lock);
1324 return 0;
1325}
1326
eff2c4f1
SL		 1327static void null_stop_queue(struct nullb *nullb)
1328{
1329 struct request_queue *q = nullb->q;
1330
1331 if (nullb->dev->queue_mode == NULL_Q_MQ)
1332 blk_mq_stop_hw_queues(q);
eff2c4f1
SL		 1333}
1334
1335static void null_restart_queue_async(struct nullb *nullb)
1336{
1337 struct request_queue *q = nullb->q;
eff2c4f1
SL		 1338
1339 if (nullb->dev->queue_mode == NULL_Q_MQ)
1340 blk_mq_start_stopped_hw_queues(q, true);
eff2c4f1
SL		 1341}
1342
adb84284
CK		 1343static inline blk_status_t null_handle_throttled(struct nullb_cmd *cmd)
1344{
1345 struct nullb_device *dev = cmd->nq->dev;
1346 struct nullb *nullb = dev->nullb;
1347 blk_status_t sts = BLK_STS_OK;
1348 struct request *rq = cmd->rq;
1349
1350 if (!hrtimer_active(&nullb->bw_timer))
1351 hrtimer_restart(&nullb->bw_timer);
1352
1353 if (atomic_long_sub_return(blk_rq_bytes(rq), &nullb->cur_bytes) < 0) {
1354 null_stop_queue(nullb);
1355 /* race with timer */
1356 if (atomic_long_read(&nullb->cur_bytes) > 0)
1357 null_restart_queue_async(nullb);
1358 /* requeue request */
1359 sts = BLK_STS_DEV_RESOURCE;
1360 }
1361 return sts;
1362}
1363
8f94d1c1
CK		 1364static inline blk_status_t null_handle_badblocks(struct nullb_cmd *cmd,
1365 sector_t sector,
1366 sector_t nr_sectors)
1367{
1368 struct badblocks *bb = &cmd->nq->dev->badblocks;
1369 sector_t first_bad;
1370 int bad_sectors;
1371
1372 if (badblocks_check(bb, sector, nr_sectors, &first_bad, &bad_sectors))
1373 return BLK_STS_IOERR;
1374
1375 return BLK_STS_OK;
1376}
1377
7ea88e22 1378static inline blk_status_t null_handle_memory_backed(struct nullb_cmd *cmd,
ff07a02e 1379 enum req_op op,
49c7089f
DLM		 1380 sector_t sector,
1381 sector_t nr_sectors)
7ea88e22
CK		 1382{
1383 struct nullb_device *dev = cmd->nq->dev;
1384 int err;
1385
49c7089f
DLM		 1386 if (op == REQ_OP_DISCARD)
1387 return null_handle_discard(dev, sector, nr_sectors);
1388
7ea88e22
CK		 1389 if (dev->queue_mode == NULL_Q_BIO)
1390 err = null_handle_bio(cmd);
1391 else
1392 err = null_handle_rq(cmd);
1393
1394 return errno_to_blk_status(err);
1395}
1396
cecbc9ce
BVA		 1397static void nullb_zero_read_cmd_buffer(struct nullb_cmd *cmd)
1398{
1399 struct nullb_device *dev = cmd->nq->dev;
1400 struct bio *bio;
1401
1402 if (dev->memory_backed)
1403 return;
1404
1405 if (dev->queue_mode == NULL_Q_BIO && bio_op(cmd->bio) == REQ_OP_READ) {
1406 zero_fill_bio(cmd->bio);
1407 } else if (req_op(cmd->rq) == REQ_OP_READ) {
1408 __rq_for_each_bio(bio, cmd->rq)
1409 zero_fill_bio(bio);
1410 }
1411}
1412
a3d7d674
CK		 1413static inline void nullb_complete_cmd(struct nullb_cmd *cmd)
1414{
cecbc9ce
BVA		 1415 /*
1416 * Since root privileges are required to configure the null_blk
1417 * driver, it is fine that this driver does not initialize the
1418 * data buffers of read commands. Zero-initialize these buffers
1419 * anyway if KMSAN is enabled to prevent that KMSAN complains
1420 * about null_blk not initializing read data buffers.
1421 */
1422 if (IS_ENABLED(CONFIG_KMSAN))
1423 nullb_zero_read_cmd_buffer(cmd);
1424
a3d7d674
CK		 1425 /* Complete IO by inline, softirq or timer */
1426 switch (cmd->nq->dev->irqmode) {
1427 case NULL_IRQ_SOFTIRQ:
1428 switch (cmd->nq->dev->queue_mode) {
1429 case NULL_Q_MQ:
63f88659 1430 blk_mq_complete_request(cmd->rq);
a3d7d674
CK		 1431 break;
1432 case NULL_Q_BIO:
1433 /*
1434 * XXX: no proper submitting cpu information available.
1435 */
1436 end_cmd(cmd);
1437 break;
1438 }
1439 break;
1440 case NULL_IRQ_NONE:
1441 end_cmd(cmd);
1442 break;
1443 case NULL_IRQ_TIMER:
1444 null_cmd_end_timer(cmd);
1445 break;
1446 }
1447}
1448
ff07a02e
BVA		 1449blk_status_t null_process_cmd(struct nullb_cmd *cmd, enum req_op op,
1450 sector_t sector, unsigned int nr_sectors)
9dd44c7e
DLM		 1451{
1452 struct nullb_device *dev = cmd->nq->dev;
1453 blk_status_t ret;
1454
1455 if (dev->badblocks.shift != -1) {
1456 ret = null_handle_badblocks(cmd, sector, nr_sectors);
1457 if (ret != BLK_STS_OK)
1458 return ret;
1459 }
1460
1461 if (dev->memory_backed)
49c7089f 1462 return null_handle_memory_backed(cmd, op, sector, nr_sectors);
9dd44c7e
DLM		 1463
1464 return BLK_STS_OK;
1465}
1466
d4b186ed 1467static blk_status_t null_handle_cmd(struct nullb_cmd *cmd, sector_t sector,
ff07a02e 1468 sector_t nr_sectors, enum req_op op)
5bcd0e0c
SL		 1469{
1470 struct nullb_device *dev = cmd->nq->dev;
eff2c4f1 1471 struct nullb *nullb = dev->nullb;
adb84284 1472 blk_status_t sts;
5bcd0e0c 1473
eff2c4f1 1474 if (test_bit(NULLB_DEV_FL_THROTTLED, &dev->flags)) {
adb84284
CK		 1475 sts = null_handle_throttled(cmd);
1476 if (sts != BLK_STS_OK)
1477 return sts;
eff2c4f1
SL		 1478 }
1479
d4b186ed
CK		 1480 if (op == REQ_OP_FLUSH) {
1481 cmd->error = errno_to_blk_status(null_handle_flush(nullb));
1482 goto out;
1483 }
d4b186ed 1484
9dd44c7e 1485 if (dev->zoned)
de3510e5 1486 sts = null_process_zoned_cmd(cmd, op, sector, nr_sectors);
9dd44c7e 1487 else
de3510e5
DLM		 1488 sts = null_process_cmd(cmd, op, sector, nr_sectors);
1489
1490 /* Do not overwrite errors (e.g. timeout errors) */
1491 if (cmd->error == BLK_STS_OK)
1492 cmd->error = sts;
fceb5d1b 1493
2f54a613 1494out:
a3d7d674 1495 nullb_complete_cmd(cmd);
5bcd0e0c 1496 return BLK_STS_OK;
f2298c04
JA		 1497}
1498
eff2c4f1
SL		 1499static enum hrtimer_restart nullb_bwtimer_fn(struct hrtimer *timer)
1500{
1501 struct nullb *nullb = container_of(timer, struct nullb, bw_timer);
1502 ktime_t timer_interval = ktime_set(0, TIMER_INTERVAL);
1503 unsigned int mbps = nullb->dev->mbps;
1504
1505 if (atomic_long_read(&nullb->cur_bytes) == mb_per_tick(mbps))
1506 return HRTIMER_NORESTART;
1507
1508 atomic_long_set(&nullb->cur_bytes, mb_per_tick(mbps));
1509 null_restart_queue_async(nullb);
1510
1511 hrtimer_forward_now(&nullb->bw_timer, timer_interval);
1512
1513 return HRTIMER_RESTART;
1514}
1515
1516static void nullb_setup_bwtimer(struct nullb *nullb)
1517{
1518 ktime_t timer_interval = ktime_set(0, TIMER_INTERVAL);
1519
1520 hrtimer_init(&nullb->bw_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1521 nullb->bw_timer.function = nullb_bwtimer_fn;
1522 atomic_long_set(&nullb->cur_bytes, mb_per_tick(nullb->dev->mbps));
1523 hrtimer_start(&nullb->bw_timer, timer_interval, HRTIMER_MODE_REL);
f2298c04
JA		 1524}
1525
1526static struct nullb_queue *nullb_to_queue(struct nullb *nullb)
1527{
1528 int index = 0;
1529
1530 if (nullb->nr_queues != 1)
1531 index = raw_smp_processor_id() / ((nr_cpu_ids + nullb->nr_queues - 1) / nullb->nr_queues);
1532
1533 return &nullb->queues[index];
1534}
1535
3e08773c 1536static void null_submit_bio(struct bio *bio)
f2298c04 1537{
d4b186ed
CK		 1538 sector_t sector = bio->bi_iter.bi_sector;
1539 sector_t nr_sectors = bio_sectors(bio);
309dca30 1540 struct nullb *nullb = bio->bi_bdev->bd_disk->private_data;
f2298c04 1541 struct nullb_queue *nq = nullb_to_queue(nullb);
f2298c04 1542
3d3472f3 1543 null_handle_cmd(alloc_cmd(nq, bio), sector, nr_sectors, bio_op(bio));
f2298c04
JA		 1544}
1545
bb4c19e0
AM		 1546#ifdef CONFIG_BLK_DEV_NULL_BLK_FAULT_INJECTION
1547
1548static bool should_timeout_request(struct request *rq)
1549{
1550 struct nullb_cmd *cmd = blk_mq_rq_to_pdu(rq);
1551 struct nullb_device *dev = cmd->nq->dev;
1552
1553 return should_fail(&dev->timeout_config.attr, 1);
1554}
1555
1556static bool should_requeue_request(struct request *rq)
1557{
1558 struct nullb_cmd *cmd = blk_mq_rq_to_pdu(rq);
1559 struct nullb_device *dev = cmd->nq->dev;
1560
1561 return should_fail(&dev->requeue_config.attr, 1);
1562}
1563
1564static bool should_init_hctx_fail(struct nullb_device *dev)
1565{
1566 return should_fail(&dev->init_hctx_fault_config.attr, 1);
1567}
1568
1569#else
1570
93b57046
JA		 1571static bool should_timeout_request(struct request *rq)
1572{
24941b90
JA		 1573 return false;
1574}
93b57046 1575
24941b90
JA		 1576static bool should_requeue_request(struct request *rq)
1577{
93b57046
JA		 1578 return false;
1579}
1580
bb4c19e0
AM		 1581static bool should_init_hctx_fail(struct nullb_device *dev)
1582{
1583 return false;
1584}
1585
1586#endif
1587
a4e1d0b7 1588static void null_map_queues(struct blk_mq_tag_set *set)
0a593fbb
JA		 1589{
1590 struct nullb *nullb = set->driver_data;
1591 int i, qoff;
15dfc662
SK		 1592 unsigned int submit_queues = g_submit_queues;
1593 unsigned int poll_queues = g_poll_queues;
1594
1595 if (nullb) {
1596 struct nullb_device *dev = nullb->dev;
1597
1598 /*
1599 * Refer nr_hw_queues of the tag set to check if the expected
1600 * number of hardware queues are prepared. If block layer failed
1601 * to prepare them, use previous numbers of submit queues and
1602 * poll queues to map queues.
1603 */
1604 if (set->nr_hw_queues ==
1605 dev->submit_queues + dev->poll_queues) {
1606 submit_queues = dev->submit_queues;
1607 poll_queues = dev->poll_queues;
1608 } else if (set->nr_hw_queues ==
1609 dev->prev_submit_queues + dev->prev_poll_queues) {
1610 submit_queues = dev->prev_submit_queues;
1611 poll_queues = dev->prev_poll_queues;
1612 } else {
1613 pr_warn("tag set has unexpected nr_hw_queues: %d\n",
1614 set->nr_hw_queues);
10b41ea1
BVA		 1615 WARN_ON_ONCE(true);
1616 submit_queues = 1;
1617 poll_queues = 0;
15dfc662
SK		 1618 }
1619 }
0a593fbb
JA		 1620
1621 for (i = 0, qoff = 0; i < set->nr_maps; i++) {
1622 struct blk_mq_queue_map *map = &set->map[i];
1623
1624 switch (i) {
1625 case HCTX_TYPE_DEFAULT:
15dfc662 1626 map->nr_queues = submit_queues;
0a593fbb
JA		 1627 break;
1628 case HCTX_TYPE_READ:
1629 map->nr_queues = 0;
1630 continue;
1631 case HCTX_TYPE_POLL:
15dfc662 1632 map->nr_queues = poll_queues;
0a593fbb
JA		 1633 break;
1634 }
1635 map->queue_offset = qoff;
1636 qoff += map->nr_queues;
1637 blk_mq_map_queues(map);
1638 }
0a593fbb
JA		 1639}
1640
1641static int null_poll(struct blk_mq_hw_ctx *hctx, struct io_comp_batch *iob)
1642{
1643 struct nullb_queue *nq = hctx->driver_data;
1644 LIST_HEAD(list);
1645 int nr = 0;
1646
1647 spin_lock(&nq->poll_lock);
1648 list_splice_init(&nq->poll_list, &list);
1649 spin_unlock(&nq->poll_lock);
1650
1651 while (!list_empty(&list)) {
1652 struct nullb_cmd *cmd;
1653 struct request *req;
1654
1655 req = list_first_entry(&list, struct request, queuelist);
1656 list_del_init(&req->queuelist);
1657 cmd = blk_mq_rq_to_pdu(req);
1658 cmd->error = null_process_cmd(cmd, req_op(req), blk_rq_pos(req),
1659 blk_rq_sectors(req));
c5eafd79 1660 if (!blk_mq_add_to_batch(req, iob, (__force int) cmd->error,
2385ebf3
ML		 1661 blk_mq_end_request_batch))
1662 end_cmd(cmd);
0a593fbb
JA		 1663 nr++;
1664 }
1665
1666 return nr;
1667}
1668
9bdb4833 1669static enum blk_eh_timer_return null_timeout_rq(struct request *rq)
5448aca4 1670{
0a593fbb 1671 struct blk_mq_hw_ctx *hctx = rq->mq_hctx;
de3510e5
DLM		 1672 struct nullb_cmd *cmd = blk_mq_rq_to_pdu(rq);
1673
9c7eddf1 1674 pr_info("rq %p timed out\n", rq);
de3510e5 1675
0a593fbb
JA		 1676 if (hctx->type == HCTX_TYPE_POLL) {
1677 struct nullb_queue *nq = hctx->driver_data;
1678
1679 spin_lock(&nq->poll_lock);
1680 list_del_init(&rq->queuelist);
1681 spin_unlock(&nq->poll_lock);
1682 }
1683
de3510e5
DLM		 1684 /*
1685 * If the device is marked as blocking (i.e. memory backed or zoned
1686 * device), the submission path may be blocked waiting for resources
1687 * and cause real timeouts. For these real timeouts, the submission
1688 * path will complete the request using blk_mq_complete_request().
1689 * Only fake timeouts need to execute blk_mq_complete_request() here.
1690 */
1691 cmd->error = BLK_STS_TIMEOUT;
3e3876d3 1692 if (cmd->fake_timeout || hctx->type == HCTX_TYPE_POLL)
de3510e5 1693 blk_mq_complete_request(rq);
0df0bb08 1694 return BLK_EH_DONE;
5448aca4
JA		 1695}
1696
fc17b653 1697static blk_status_t null_queue_rq(struct blk_mq_hw_ctx *hctx,
b6402014 1698 const struct blk_mq_queue_data *bd)
f2298c04 1699{
b6402014
DLM		 1700 struct request *rq = bd->rq;
1701 struct nullb_cmd *cmd = blk_mq_rq_to_pdu(rq);
2984c868 1702 struct nullb_queue *nq = hctx->driver_data;
b6402014
DLM		 1703 sector_t nr_sectors = blk_rq_sectors(rq);
1704 sector_t sector = blk_rq_pos(rq);
0a593fbb 1705 const bool is_poll = hctx->type == HCTX_TYPE_POLL;
f2298c04 1706
db5bcf87
JA		 1707 might_sleep_if(hctx->flags & BLK_MQ_F_BLOCKING);
1708
0a593fbb 1709 if (!is_poll && nq->dev->irqmode == NULL_IRQ_TIMER) {
3c395a96
PV		 1710 hrtimer_init(&cmd->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1711 cmd->timer.function = null_cmd_timer_expired;
1712 }
b6402014 1713 cmd->rq = rq;
ff770422 1714 cmd->error = BLK_STS_OK;
2984c868 1715 cmd->nq = nq;
b6402014
DLM		 1716 cmd->fake_timeout = should_timeout_request(rq) ||
1717 blk_should_fake_timeout(rq->q);
f2298c04 1718
b6402014 1719 blk_mq_start_request(rq);
e2490073 1720
b6402014 1721 if (should_requeue_request(rq)) {
24941b90
JA		 1722 /*
1723 * Alternate between hitting the core BUSY path, and the
1724 * driver driven requeue path
1725 */
1726 nq->requeue_selection++;
1727 if (nq->requeue_selection & 1)
1728 return BLK_STS_RESOURCE;
b6402014
DLM		 1729 blk_mq_requeue_request(rq, true);
1730 return BLK_STS_OK;
24941b90 1731 }
0a593fbb
JA		 1732
1733 if (is_poll) {
1734 spin_lock(&nq->poll_lock);
b6402014 1735 list_add_tail(&rq->queuelist, &nq->poll_list);
0a593fbb
JA		 1736 spin_unlock(&nq->poll_lock);
1737 return BLK_STS_OK;
1738 }
de3510e5 1739 if (cmd->fake_timeout)
24941b90 1740 return BLK_STS_OK;
93b57046 1741
b6402014 1742 return null_handle_cmd(cmd, sector, nr_sectors, req_op(rq));
f2298c04
JA		 1743}
1744
de65d2d2
MB		 1745static void cleanup_queue(struct nullb_queue *nq)
1746{
eb25ad80 1747 bitmap_free(nq->tag_map);
de65d2d2
MB		 1748 kfree(nq->cmds);
1749}
1750
1751static void cleanup_queues(struct nullb *nullb)
1752{
1753 int i;
1754
1755 for (i = 0; i < nullb->nr_queues; i++)
1756 cleanup_queue(&nullb->queues[i]);
1757
1758 kfree(nullb->queues);
1759}
1760
78b10be2
BVA		 1761static void null_exit_hctx(struct blk_mq_hw_ctx *hctx, unsigned int hctx_idx)
1762{
1763 struct nullb_queue *nq = hctx->driver_data;
1764 struct nullb *nullb = nq->dev->nullb;
1765
1766 nullb->nr_queues--;
1767}
1768
1769static void null_init_queue(struct nullb *nullb, struct nullb_queue *nq)
1770{
1771 init_waitqueue_head(&nq->wait);
1772 nq->queue_depth = nullb->queue_depth;
1773 nq->dev = nullb->dev;
0a593fbb
JA		 1774 INIT_LIST_HEAD(&nq->poll_list);
1775 spin_lock_init(&nq->poll_lock);
78b10be2
BVA		 1776}
1777
1778static int null_init_hctx(struct blk_mq_hw_ctx *hctx, void *driver_data,
1779 unsigned int hctx_idx)
1780{
1781 struct nullb *nullb = hctx->queue->queuedata;
1782 struct nullb_queue *nq;
1783
bb4c19e0 1784 if (should_init_hctx_fail(nullb->dev))
596444e7 1785 return -EFAULT;
596444e7 1786
78b10be2
BVA		 1787 nq = &nullb->queues[hctx_idx];
1788 hctx->driver_data = nq;
1789 null_init_queue(nullb, nq);
1790 nullb->nr_queues++;
1791
1792 return 0;
1793}
1794
1795static const struct blk_mq_ops null_mq_ops = {
1796 .queue_rq = null_queue_rq,
1797 .complete = null_complete_rq,
1798 .timeout = null_timeout_rq,
0a593fbb
JA		 1799 .poll = null_poll,
1800 .map_queues = null_map_queues,
78b10be2
BVA		 1801 .init_hctx = null_init_hctx,
1802 .exit_hctx = null_exit_hctx,
1803};
1804
9ae2d0aa
MB		 1805static void null_del_dev(struct nullb *nullb)
1806{
9b03b713
BVA		 1807 struct nullb_device *dev;
1808
1809 if (!nullb)
1810 return;
1811
1812 dev = nullb->dev;
2984c868 1813
94bc02e3
SL		 1814 ida_simple_remove(&nullb_indexes, nullb->index);
1815
9ae2d0aa
MB		 1816 list_del_init(&nullb->list);
1817
74ede5af 1818 del_gendisk(nullb->disk);
eff2c4f1
SL		 1819
1820 if (test_bit(NULLB_DEV_FL_THROTTLED, &nullb->dev->flags)) {
1821 hrtimer_cancel(&nullb->bw_timer);
1822 atomic_long_set(&nullb->cur_bytes, LONG_MAX);
1823 null_restart_queue_async(nullb);
1824 }
1825
8b9ab626 1826 put_disk(nullb->disk);
2984c868
SL		 1827 if (dev->queue_mode == NULL_Q_MQ &&
1828 nullb->tag_set == &nullb->__tag_set)
82f402fe 1829 blk_mq_free_tag_set(nullb->tag_set);
9ae2d0aa 1830 cleanup_queues(nullb);
deb78b41
SL		 1831 if (null_cache_active(nullb))
1832 null_free_device_storage(nullb->dev, true);
9ae2d0aa 1833 kfree(nullb);
2984c868 1834 dev->nullb = NULL;
9ae2d0aa
MB		 1835}
1836
306eb6b4
SL		 1837static void null_config_discard(struct nullb *nullb)
1838{
1839 if (nullb->dev->discard == false)
1840 return;
1592cd15 1841
49c7089f
DLM		 1842 if (!nullb->dev->memory_backed) {
1843 nullb->dev->discard = false;
1844 pr_info("discard option is ignored without memory backing\n");
1845 return;
1846 }
1847
1592cd15
CK		 1848 if (nullb->dev->zoned) {
1849 nullb->dev->discard = false;
1850 pr_info("discard option is ignored in zoned mode\n");
1851 return;
1852 }
1853
306eb6b4 1854 nullb->q->limits.discard_granularity = nullb->dev->blocksize;
306eb6b4 1855 blk_queue_max_discard_sectors(nullb->q, UINT_MAX >> 9);
9ae2d0aa
MB		 1856}
1857
c62b37d9
CH		 1858static const struct block_device_operations null_bio_ops = {
1859 .owner = THIS_MODULE,
1860 .submit_bio = null_submit_bio,
1861 .report_zones = null_report_zones,
1862};
1863
1864static const struct block_device_operations null_rq_ops = {
e3f89564 1865 .owner = THIS_MODULE,
7fc8fb51 1866 .report_zones = null_report_zones,
f2298c04
JA		 1867};
1868
1869static int setup_commands(struct nullb_queue *nq)
1870{
1871 struct nullb_cmd *cmd;
eb25ad80 1872 int i;
f2298c04 1873
6396bb22 1874 nq->cmds = kcalloc(nq->queue_depth, sizeof(*cmd), GFP_KERNEL);
f2298c04 1875 if (!nq->cmds)
2d263a78 1876 return -ENOMEM;
f2298c04 1877
eb25ad80 1878 nq->tag_map = bitmap_zalloc(nq->queue_depth, GFP_KERNEL);
f2298c04
JA		 1879 if (!nq->tag_map) {
1880 kfree(nq->cmds);
2d263a78 1881 return -ENOMEM;
f2298c04
JA		 1882 }
1883
1884 for (i = 0; i < nq->queue_depth; i++) {
1885 cmd = &nq->cmds[i];
f2298c04
JA		 1886 cmd->tag = -1U;
1887 }
1888
1889 return 0;
1890}
1891
f2298c04
JA		 1892static int setup_queues(struct nullb *nullb)
1893{
0a593fbb
JA		 1894 int nqueues = nr_cpu_ids;
1895
1896 if (g_poll_queues)
1897 nqueues += g_poll_queues;
1898
1899 nullb->queues = kcalloc(nqueues, sizeof(struct nullb_queue),
6396bb22 1900 GFP_KERNEL);
f2298c04 1901 if (!nullb->queues)
2d263a78 1902 return -ENOMEM;
f2298c04 1903
2984c868 1904 nullb->queue_depth = nullb->dev->hw_queue_depth;
2d263a78
MB		 1905 return 0;
1906}
1907
1908static int init_driver_queues(struct nullb *nullb)
1909{
1910 struct nullb_queue *nq;
1911 int i, ret = 0;
f2298c04 1912
2984c868 1913 for (i = 0; i < nullb->dev->submit_queues; i++) {
f2298c04 1914 nq = &nullb->queues[i];
2d263a78
MB		 1915
1916 null_init_queue(nullb, nq);
1917
1918 ret = setup_commands(nq);
1919 if (ret)
31f9690e 1920 return ret;
f2298c04
JA		 1921 nullb->nr_queues++;
1922 }
2d263a78 1923 return 0;
f2298c04
JA		 1924}
1925
9ae2d0aa 1926static int null_gendisk_register(struct nullb *nullb)
f2298c04 1927{
979d5447 1928 sector_t size = ((sector_t)nullb->dev->size * SZ_1M) >> SECTOR_SHIFT;
132226b3 1929 struct gendisk *disk = nullb->disk;
9ae2d0aa 1930
979d5447 1931 set_capacity(disk, size);
9ae2d0aa 1932
9ae2d0aa
MB		 1933 disk->major = null_major;
1934 disk->first_minor = nullb->index;
132226b3 1935 disk->minors = 1;
c62b37d9
CH		 1936 if (queue_is_mq(nullb->q))
1937 disk->fops = &null_rq_ops;
1938 else
1939 disk->fops = &null_bio_ops;
9ae2d0aa 1940 disk->private_data = nullb;
9ae2d0aa
MB		 1941 strncpy(disk->disk_name, nullb->disk_name, DISK_NAME_LEN);
1942
bf505456 1943 if (nullb->dev->zoned) {
d205bde7
DLM		 1944 int ret = null_register_zoned_dev(nullb);
1945
1946 if (ret)
1947 return ret;
bf505456
DLM		 1948 }
1949
10e7123d 1950 return add_disk(disk);
9ae2d0aa
MB		 1951}
1952
2984c868 1953static int null_init_tag_set(struct nullb *nullb, struct blk_mq_tag_set *set)
82f402fe 1954{
7012eef5
VF		 1955 unsigned int flags = BLK_MQ_F_SHOULD_MERGE;
1956 int hw_queues, numa_node;
1957 unsigned int queue_depth;
0a593fbb
JA		 1958 int poll_queues;
1959
7012eef5
VF		 1960 if (nullb) {
1961 hw_queues = nullb->dev->submit_queues;
1962 poll_queues = nullb->dev->poll_queues;
1963 queue_depth = nullb->dev->hw_queue_depth;
1964 numa_node = nullb->dev->home_node;
1965 if (nullb->dev->no_sched)
1966 flags |= BLK_MQ_F_NO_SCHED;
1967 if (nullb->dev->shared_tag_bitmap)
1968 flags |= BLK_MQ_F_TAG_HCTX_SHARED;
1969 if (nullb->dev->blocking)
1970 flags |= BLK_MQ_F_BLOCKING;
1971 } else {
1972 hw_queues = g_submit_queues;
1973 poll_queues = g_poll_queues;
1974 queue_depth = g_hw_queue_depth;
1975 numa_node = g_home_node;
1976 if (g_no_sched)
1977 flags |= BLK_MQ_F_NO_SCHED;
1978 if (g_shared_tag_bitmap)
1979 flags |= BLK_MQ_F_TAG_HCTX_SHARED;
1980 if (g_blocking)
1981 flags |= BLK_MQ_F_BLOCKING;
1982 }
1983
82f402fe 1984 set->ops = &null_mq_ops;
82f402fe 1985 set->cmd_size = sizeof(struct nullb_cmd);
7012eef5 1986 set->flags = flags;
0a593fbb 1987 set->driver_data = nullb;
7012eef5
VF		 1988 set->nr_hw_queues = hw_queues;
1989 set->queue_depth = queue_depth;
1990 set->numa_node = numa_node;
1991 if (poll_queues) {
1992 set->nr_hw_queues += poll_queues;
0a593fbb 1993 set->nr_maps = 3;
7012eef5 1994 } else {
0a593fbb 1995 set->nr_maps = 1;
7012eef5 1996 }
82f402fe
JA		 1997
1998 return blk_mq_alloc_tag_set(set);
1999}
2000
5c4bd1f4 2001static int null_validate_conf(struct nullb_device *dev)
cedcafad 2002{
63f8793e
CK		 2003 if (dev->queue_mode == NULL_Q_RQ) {
2004 pr_err("legacy IO path is no longer available\n");
2005 return -EINVAL;
2006 }
2007
cedcafad
SL		 2008 dev->blocksize = round_down(dev->blocksize, 512);
2009 dev->blocksize = clamp_t(unsigned int, dev->blocksize, 512, 4096);
cedcafad
SL		 2010
2011 if (dev->queue_mode == NULL_Q_MQ && dev->use_per_node_hctx) {
2012 if (dev->submit_queues != nr_online_nodes)
2013 dev->submit_queues = nr_online_nodes;
2014 } else if (dev->submit_queues > nr_cpu_ids)
2015 dev->submit_queues = nr_cpu_ids;
2016 else if (dev->submit_queues == 0)
2017 dev->submit_queues = 1;
15dfc662
SK		 2018 dev->prev_submit_queues = dev->submit_queues;
2019
2020 if (dev->poll_queues > g_poll_queues)
2021 dev->poll_queues = g_poll_queues;
15dfc662 2022 dev->prev_poll_queues = dev->poll_queues;
cedcafad
SL		 2023
2024 dev->queue_mode = min_t(unsigned int, dev->queue_mode, NULL_Q_MQ);
2025 dev->irqmode = min_t(unsigned int, dev->irqmode, NULL_IRQ_TIMER);
5bcd0e0c
SL		 2026
2027 /* Do memory allocation, so set blocking */
2028 if (dev->memory_backed)
2029 dev->blocking = true;
deb78b41
SL		 2030 else /* cache is meaningless */
2031 dev->cache_size = 0;
2032 dev->cache_size = min_t(unsigned long, ULONG_MAX / 1024 / 1024,
2033 dev->cache_size);
eff2c4f1
SL		 2034 dev->mbps = min_t(unsigned int, 1024 * 40, dev->mbps);
2035 /* can not stop a queue */
2036 if (dev->queue_mode == NULL_Q_BIO)
2037 dev->mbps = 0;
5c4bd1f4
DLM		 2038
2039 if (dev->zoned &&
2040 (!dev->zone_size || !is_power_of_2(dev->zone_size))) {
2041 pr_err("zone_size must be power-of-two\n");
2042 return -EINVAL;
2043 }
2044
2045 return 0;
cedcafad
SL		 2046}
2047
33f782c4 2048#ifdef CONFIG_BLK_DEV_NULL_BLK_FAULT_INJECTION
24941b90
JA		 2049static bool __null_setup_fault(struct fault_attr *attr, char *str)
2050{
2051 if (!str[0])
93b57046
JA		 2052 return true;
2053
24941b90 2054 if (!setup_fault_attr(attr, str))
93b57046
JA		 2055 return false;
2056
24941b90
JA		 2057 attr->verbose = 0;
2058 return true;
2059}
2060#endif
2061
2062static bool null_setup_fault(void)
2063{
2064#ifdef CONFIG_BLK_DEV_NULL_BLK_FAULT_INJECTION
2065 if (!__null_setup_fault(&null_timeout_attr, g_timeout_str))
2066 return false;
2067 if (!__null_setup_fault(&null_requeue_attr, g_requeue_str))
2068 return false;
596444e7
BVA		 2069 if (!__null_setup_fault(&null_init_hctx_attr, g_init_hctx_str))
2070 return false;
33f782c4 2071#endif
93b57046
JA		 2072 return true;
2073}
2074
2984c868 2075static int null_add_dev(struct nullb_device *dev)
9ae2d0aa
MB		 2076{
2077 struct nullb *nullb;
dc501dc0 2078 int rv;
f2298c04 2079
5c4bd1f4
DLM		 2080 rv = null_validate_conf(dev);
2081 if (rv)
2082 return rv;
cedcafad 2083
2984c868 2084 nullb = kzalloc_node(sizeof(*nullb), GFP_KERNEL, dev->home_node);
dc501dc0
RE		 2085 if (!nullb) {
2086 rv = -ENOMEM;
24d2f903 2087 goto out;
dc501dc0 2088 }
2984c868
SL		 2089 nullb->dev = dev;
2090 dev->nullb = nullb;
f2298c04
JA		 2091
2092 spin_lock_init(&nullb->lock);
2093
dc501dc0
RE		 2094 rv = setup_queues(nullb);
2095 if (rv)
24d2f903 2096 goto out_free_nullb;
f2298c04 2097
2984c868 2098 if (dev->queue_mode == NULL_Q_MQ) {
82f402fe
JA		 2099 if (shared_tags) {
2100 nullb->tag_set = &tag_set;
2101 rv = 0;
2102 } else {
2103 nullb->tag_set = &nullb->__tag_set;
2984c868 2104 rv = null_init_tag_set(nullb, nullb->tag_set);
82f402fe
JA		 2105 }
2106
dc501dc0 2107 if (rv)
24d2f903
CH		 2108 goto out_cleanup_queues;
2109
5448aca4 2110 nullb->tag_set->timeout = 5 * HZ;
6759b1a2
CH		 2111 nullb->disk = blk_mq_alloc_disk(nullb->tag_set, nullb);
2112 if (IS_ERR(nullb->disk)) {
2113 rv = PTR_ERR(nullb->disk);
24d2f903 2114 goto out_cleanup_tags;
6759b1a2
CH		 2115 }
2116 nullb->q = nullb->disk->queue;
2984c868 2117 } else if (dev->queue_mode == NULL_Q_BIO) {
132226b3
CH		 2118 rv = -ENOMEM;
2119 nullb->disk = blk_alloc_disk(nullb->dev->home_node);
2120 if (!nullb->disk)
24d2f903 2121 goto out_cleanup_queues;
132226b3
CH		 2122
2123 nullb->q = nullb->disk->queue;
31f9690e
JK		 2124 rv = init_driver_queues(nullb);
2125 if (rv)
132226b3 2126 goto out_cleanup_disk;
f2298c04
JA		 2127 }
2128
eff2c4f1
SL		 2129 if (dev->mbps) {
2130 set_bit(NULLB_DEV_FL_THROTTLED, &dev->flags);
2131 nullb_setup_bwtimer(nullb);
2132 }
2133
deb78b41
SL		 2134 if (dev->cache_size > 0) {
2135 set_bit(NULLB_DEV_FL_CACHE, &nullb->dev->flags);
2136 blk_queue_write_cache(nullb->q, true, true);
deb78b41
SL		 2137 }
2138
ca4b2a01 2139 if (dev->zoned) {
d205bde7 2140 rv = null_init_zoned_dev(dev, nullb->q);
ca4b2a01 2141 if (rv)
132226b3 2142 goto out_cleanup_disk;
ca4b2a01
MB		 2143 }
2144
f2298c04 2145 nullb->q->queuedata = nullb;
8b904b5b 2146 blk_queue_flag_set(QUEUE_FLAG_NONROT, nullb->q);
f2298c04 2147
f2298c04 2148 mutex_lock(&lock);
ee452a8d
DC		 2149 rv = ida_simple_get(&nullb_indexes, 0, 0, GFP_KERNEL);
2150 if (rv < 0) {
2151 mutex_unlock(&lock);
2152 goto out_cleanup_zone;
2153 }
2154 nullb->index = rv;
2155 dev->index = rv;
f2298c04
JA		 2156 mutex_unlock(&lock);
2157
2984c868
SL		 2158 blk_queue_logical_block_size(nullb->q, dev->blocksize);
2159 blk_queue_physical_block_size(nullb->q, dev->blocksize);
ea17fd35
DLM		 2160 if (!dev->max_sectors)
2161 dev->max_sectors = queue_max_hw_sectors(nullb->q);
0a26f327 2162 dev->max_sectors = min(dev->max_sectors, BLK_DEF_MAX_SECTORS);
ea17fd35 2163 blk_queue_max_hw_sectors(nullb->q, dev->max_sectors);
f2298c04 2164
cee1b215
MG		 2165 if (dev->virt_boundary)
2166 blk_queue_virt_boundary(nullb->q, PAGE_SIZE - 1);
2167
306eb6b4 2168 null_config_discard(nullb);
f2298c04 2169
bb4c19e0 2170 if (config_item_name(&dev->group.cg_item)) {
49c3b926
DLM		 2171 /* Use configfs dir name as the device name */
2172 snprintf(nullb->disk_name, sizeof(nullb->disk_name),
bb4c19e0 2173 "%s", config_item_name(&dev->group.cg_item));
49c3b926
DLM		 2174 } else {
2175 sprintf(nullb->disk_name, "nullb%d", nullb->index);
2176 }
b2b7e001 2177
74ede5af 2178 rv = null_gendisk_register(nullb);
9ae2d0aa 2179 if (rv)
ee452a8d 2180 goto out_ida_free;
a514379b
MB		 2181
2182 mutex_lock(&lock);
2183 list_add_tail(&nullb->list, &nullb_list);
2184 mutex_unlock(&lock);
3681c85d 2185
db060f54
DLM		 2186 pr_info("disk %s created\n", nullb->disk_name);
2187
f2298c04 2188 return 0;
ee452a8d
DC		 2189
2190out_ida_free:
2191 ida_free(&nullb_indexes, nullb->index);
ca4b2a01 2192out_cleanup_zone:
d205bde7 2193 null_free_zoned_dev(dev);
132226b3 2194out_cleanup_disk:
8b9ab626 2195 put_disk(nullb->disk);
24d2f903 2196out_cleanup_tags:
2984c868 2197 if (dev->queue_mode == NULL_Q_MQ && nullb->tag_set == &nullb->__tag_set)
82f402fe 2198 blk_mq_free_tag_set(nullb->tag_set);
24d2f903
CH		 2199out_cleanup_queues:
2200 cleanup_queues(nullb);
2201out_free_nullb:
2202 kfree(nullb);
2004bfde 2203 dev->nullb = NULL;
24d2f903 2204out:
dc501dc0 2205 return rv;
f2298c04
JA		 2206}
2207
49c3b926
DLM		 2208static struct nullb *null_find_dev_by_name(const char *name)
2209{
2210 struct nullb *nullb = NULL, *nb;
2211
2212 mutex_lock(&lock);
2213 list_for_each_entry(nb, &nullb_list, list) {
2214 if (strcmp(nb->disk_name, name) == 0) {
2215 nullb = nb;
2216 break;
2217 }
2218 }
2219 mutex_unlock(&lock);
2220
2221 return nullb;
2222}
2223
b3a0a73e
DLM		 2224static int null_create_dev(void)
2225{
2226 struct nullb_device *dev;
2227 int ret;
2228
2229 dev = null_alloc_dev();
2230 if (!dev)
2231 return -ENOMEM;
2232
2233 ret = null_add_dev(dev);
2234 if (ret) {
2235 null_free_dev(dev);
2236 return ret;
2237 }
2238
2239 return 0;
2240}
2241
2242static void null_destroy_dev(struct nullb *nullb)
2243{
2244 struct nullb_device *dev = nullb->dev;
2245
2246 null_del_dev(nullb);
8cfb9819 2247 null_free_device_storage(dev, false);
b3a0a73e
DLM		 2248 null_free_dev(dev);
2249}
2250
f2298c04
JA		 2251static int __init null_init(void)
2252{
af096e22 2253 int ret = 0;
f2298c04 2254 unsigned int i;
af096e22 2255 struct nullb *nullb;
f2298c04 2256
2984c868 2257 if (g_bs > PAGE_SIZE) {
9c7eddf1
AA		 2258 pr_warn("invalid block size\n");
2259 pr_warn("defaults block size to %lu\n", PAGE_SIZE);
2984c868 2260 g_bs = PAGE_SIZE;
9967d8ac 2261 }
f2298c04 2262
ea17fd35
DLM		 2263 if (g_max_sectors > BLK_DEF_MAX_SECTORS) {
2264 pr_warn("invalid max sectors\n");
2265 pr_warn("defaults max sectors to %u\n", BLK_DEF_MAX_SECTORS);
2266 g_max_sectors = BLK_DEF_MAX_SECTORS;
2267 }
2268
7ff684a6 2269 if (g_home_node != NUMA_NO_NODE && g_home_node >= nr_online_nodes) {
9c7eddf1 2270 pr_err("invalid home_node value\n");
7ff684a6
JP		 2271 g_home_node = NUMA_NO_NODE;
2272 }
2273
bb4c19e0
AM		 2274 if (!null_setup_fault())
2275 return -EINVAL;
2276
e50b1e32 2277 if (g_queue_mode == NULL_Q_RQ) {
525323d2 2278 pr_err("legacy IO path is no longer available\n");
e50b1e32
JA		 2279 return -EINVAL;
2280 }
525323d2 2281
2984c868
SL		 2282 if (g_queue_mode == NULL_Q_MQ && g_use_per_node_hctx) {
2283 if (g_submit_queues != nr_online_nodes) {
9c7eddf1 2284 pr_warn("submit_queues param is set to %u.\n",
525323d2 2285 nr_online_nodes);
2984c868 2286 g_submit_queues = nr_online_nodes;
fc1bc354 2287 }
525323d2 2288 } else if (g_submit_queues > nr_cpu_ids) {
2984c868 2289 g_submit_queues = nr_cpu_ids;
525323d2 2290 } else if (g_submit_queues <= 0) {
2984c868 2291 g_submit_queues = 1;
525323d2 2292 }
f2298c04 2293
2984c868
SL		 2294 if (g_queue_mode == NULL_Q_MQ && shared_tags) {
2295 ret = null_init_tag_set(NULL, &tag_set);
db2d153d
MG		 2296 if (ret)
2297 return ret;
2298 }
2299
3bf2bd20
SL		 2300 config_group_init(&nullb_subsys.su_group);
2301 mutex_init(&nullb_subsys.su_mutex);
2302
2303 ret = configfs_register_subsystem(&nullb_subsys);
2304 if (ret)
2305 goto err_tagset;
2306
f2298c04
JA		 2307 mutex_init(&lock);
2308
f2298c04 2309 null_major = register_blkdev(0, "nullb");
db2d153d
MG		 2310 if (null_major < 0) {
2311 ret = null_major;
3bf2bd20 2312 goto err_conf;
db2d153d 2313 }
f2298c04
JA		 2314
2315 for (i = 0; i < nr_devices; i++) {
b3a0a73e
DLM		 2316 ret = null_create_dev();
2317 if (ret)
af096e22 2318 goto err_dev;
f2298c04
JA		 2319 }
2320
9c7eddf1 2321 pr_info("module loaded\n");
f2298c04 2322 return 0;
af096e22
MH		 2323
2324err_dev:
2325 while (!list_empty(&nullb_list)) {
2326 nullb = list_entry(nullb_list.next, struct nullb, list);
b3a0a73e 2327 null_destroy_dev(nullb);
af096e22 2328 }
af096e22 2329 unregister_blkdev(null_major, "nullb");
3bf2bd20
SL		 2330err_conf:
2331 configfs_unregister_subsystem(&nullb_subsys);
db2d153d 2332err_tagset:
2984c868 2333 if (g_queue_mode == NULL_Q_MQ && shared_tags)
db2d153d 2334 blk_mq_free_tag_set(&tag_set);
af096e22 2335 return ret;
f2298c04
JA		 2336}
2337
2338static void __exit null_exit(void)
2339{
2340 struct nullb *nullb;
2341
3bf2bd20
SL		 2342 configfs_unregister_subsystem(&nullb_subsys);
2343
f2298c04
JA		 2344 unregister_blkdev(null_major, "nullb");
2345
2346 mutex_lock(&lock);
2347 while (!list_empty(&nullb_list)) {
2348 nullb = list_entry(nullb_list.next, struct nullb, list);
b3a0a73e 2349 null_destroy_dev(nullb);
f2298c04
JA		 2350 }
2351 mutex_unlock(&lock);
6bb9535b 2352
2984c868 2353 if (g_queue_mode == NULL_Q_MQ && shared_tags)
82f402fe 2354 blk_mq_free_tag_set(&tag_set);
f2298c04
JA		 2355}
2356
2357module_init(null_init);
2358module_exit(null_exit);
2359
231b3db1 2360MODULE_AUTHOR("Jens Axboe <axboe@kernel.dk>");
f2298c04 2361MODULE_LICENSE("GPL");
Linux 6.x block layer and io_uring tree(s)