2 * Add configfs and memory store: Kyungchan Koh <kkc6196@fb.com> and
3 * Shaohua Li <shli@fb.com>
5 #include <linux/module.h>
7 #include <linux/moduleparam.h>
8 #include <linux/sched.h>
10 #include <linux/blkdev.h>
11 #include <linux/init.h>
12 #include <linux/slab.h>
13 #include <linux/blk-mq.h>
14 #include <linux/hrtimer.h>
15 #include <linux/lightnvm.h>
16 #include <linux/configfs.h>
17 #include <linux/badblocks.h>
19 #define SECTOR_SHIFT 9
20 #define PAGE_SECTORS_SHIFT (PAGE_SHIFT - SECTOR_SHIFT)
21 #define PAGE_SECTORS (1 << PAGE_SECTORS_SHIFT)
22 #define SECTOR_SIZE (1 << SECTOR_SHIFT)
23 #define SECTOR_MASK (PAGE_SECTORS - 1)
27 #define TICKS_PER_SEC 50ULL
28 #define TIMER_INTERVAL (NSEC_PER_SEC / TICKS_PER_SEC)
30 static inline u64
mb_per_tick(int mbps
)
32 return (1 << 20) / TICKS_PER_SEC
* ((u64
) mbps
);
36 struct list_head list
;
37 struct llist_node ll_list
;
38 call_single_data_t csd
;
42 struct nullb_queue
*nq
;
48 unsigned long *tag_map
;
49 wait_queue_head_t wait
;
50 unsigned int queue_depth
;
51 struct nullb_device
*dev
;
53 struct nullb_cmd
*cmds
;
57 * Status flags for nullb_device.
59 * CONFIGURED: Device has been configured and turned on. Cannot reconfigure.
60 * UP: Device is currently on and visible in userspace.
61 * THROTTLED: Device is being throttled.
62 * CACHE: Device is using a write-back cache.
64 enum nullb_device_flags
{
65 NULLB_DEV_FL_CONFIGURED
= 0,
67 NULLB_DEV_FL_THROTTLED
= 2,
68 NULLB_DEV_FL_CACHE
= 3,
72 * nullb_page is a page in memory for nullb devices.
74 * @page: The page holding the data.
75 * @bitmap: The bitmap represents which sector in the page has data.
76 * Each bit represents one block size. For example, sector 8
77 * will use the 7th bit
78 * The highest 2 bits of bitmap are for special purpose. LOCK means the cache
79 * page is being flushing to storage. FREE means the cache page is freed and
80 * should be skipped from flushing to storage. Please see
81 * null_make_cache_space
87 #define NULLB_PAGE_LOCK (sizeof(unsigned long) * 8 - 1)
88 #define NULLB_PAGE_FREE (sizeof(unsigned long) * 8 - 2)
92 struct config_item item
;
93 struct radix_tree_root data
; /* data stored in the disk */
94 struct radix_tree_root cache
; /* disk cache data */
95 unsigned long flags
; /* device flags */
96 unsigned int curr_cache
;
97 struct badblocks badblocks
;
99 unsigned long size
; /* device size in MB */
100 unsigned long completion_nsec
; /* time in ns to complete a request */
101 unsigned long cache_size
; /* disk cache size in MB */
102 unsigned int submit_queues
; /* number of submission queues */
103 unsigned int home_node
; /* home node for the device */
104 unsigned int queue_mode
; /* block interface */
105 unsigned int blocksize
; /* block size */
106 unsigned int irqmode
; /* IRQ completion handler */
107 unsigned int hw_queue_depth
; /* queue depth */
108 unsigned int index
; /* index of the disk, only valid with a disk */
109 unsigned int mbps
; /* Bandwidth throttle cap (in MB/s) */
110 bool use_lightnvm
; /* register as a LightNVM device */
111 bool blocking
; /* blocking blk-mq device */
112 bool use_per_node_hctx
; /* use per-node allocation for hardware context */
113 bool power
; /* power on/off the device */
114 bool memory_backed
; /* if data is stored in memory */
115 bool discard
; /* if support discard */
119 struct nullb_device
*dev
;
120 struct list_head list
;
122 struct request_queue
*q
;
123 struct gendisk
*disk
;
124 struct nvm_dev
*ndev
;
125 struct blk_mq_tag_set
*tag_set
;
126 struct blk_mq_tag_set __tag_set
;
127 unsigned int queue_depth
;
128 atomic_long_t cur_bytes
;
129 struct hrtimer bw_timer
;
130 unsigned long cache_flush_pos
;
133 struct nullb_queue
*queues
;
134 unsigned int nr_queues
;
135 char disk_name
[DISK_NAME_LEN
];
138 static LIST_HEAD(nullb_list
);
139 static struct mutex lock
;
140 static int null_major
;
141 static DEFINE_IDA(nullb_indexes
);
142 static struct kmem_cache
*ppa_cache
;
143 static struct blk_mq_tag_set tag_set
;
147 NULL_IRQ_SOFTIRQ
= 1,
157 static int g_submit_queues
= 1;
158 module_param_named(submit_queues
, g_submit_queues
, int, S_IRUGO
);
159 MODULE_PARM_DESC(submit_queues
, "Number of submission queues");
161 static int g_home_node
= NUMA_NO_NODE
;
162 module_param_named(home_node
, g_home_node
, int, S_IRUGO
);
163 MODULE_PARM_DESC(home_node
, "Home node for the device");
165 static int g_queue_mode
= NULL_Q_MQ
;
167 static int null_param_store_val(const char *str
, int *val
, int min
, int max
)
171 ret
= kstrtoint(str
, 10, &new_val
);
175 if (new_val
< min
|| new_val
> max
)
182 static int null_set_queue_mode(const char *str
, const struct kernel_param
*kp
)
184 return null_param_store_val(str
, &g_queue_mode
, NULL_Q_BIO
, NULL_Q_MQ
);
187 static const struct kernel_param_ops null_queue_mode_param_ops
= {
188 .set
= null_set_queue_mode
,
189 .get
= param_get_int
,
192 device_param_cb(queue_mode
, &null_queue_mode_param_ops
, &g_queue_mode
, S_IRUGO
);
193 MODULE_PARM_DESC(queue_mode
, "Block interface to use (0=bio,1=rq,2=multiqueue)");
195 static int g_gb
= 250;
196 module_param_named(gb
, g_gb
, int, S_IRUGO
);
197 MODULE_PARM_DESC(gb
, "Size in GB");
199 static int g_bs
= 512;
200 module_param_named(bs
, g_bs
, int, S_IRUGO
);
201 MODULE_PARM_DESC(bs
, "Block size (in bytes)");
203 static int nr_devices
= 1;
204 module_param(nr_devices
, int, S_IRUGO
);
205 MODULE_PARM_DESC(nr_devices
, "Number of devices to register");
207 static bool g_use_lightnvm
;
208 module_param_named(use_lightnvm
, g_use_lightnvm
, bool, S_IRUGO
);
209 MODULE_PARM_DESC(use_lightnvm
, "Register as a LightNVM device");
211 static bool g_blocking
;
212 module_param_named(blocking
, g_blocking
, bool, S_IRUGO
);
213 MODULE_PARM_DESC(blocking
, "Register as a blocking blk-mq driver device");
215 static bool shared_tags
;
216 module_param(shared_tags
, bool, S_IRUGO
);
217 MODULE_PARM_DESC(shared_tags
, "Share tag set between devices for blk-mq");
219 static int g_irqmode
= NULL_IRQ_SOFTIRQ
;
221 static int null_set_irqmode(const char *str
, const struct kernel_param
*kp
)
223 return null_param_store_val(str
, &g_irqmode
, NULL_IRQ_NONE
,
227 static const struct kernel_param_ops null_irqmode_param_ops
= {
228 .set
= null_set_irqmode
,
229 .get
= param_get_int
,
232 device_param_cb(irqmode
, &null_irqmode_param_ops
, &g_irqmode
, S_IRUGO
);
233 MODULE_PARM_DESC(irqmode
, "IRQ completion handler. 0-none, 1-softirq, 2-timer");
235 static unsigned long g_completion_nsec
= 10000;
236 module_param_named(completion_nsec
, g_completion_nsec
, ulong
, S_IRUGO
);
237 MODULE_PARM_DESC(completion_nsec
, "Time in ns to complete a request in hardware. Default: 10,000ns");
239 static int g_hw_queue_depth
= 64;
240 module_param_named(hw_queue_depth
, g_hw_queue_depth
, int, S_IRUGO
);
241 MODULE_PARM_DESC(hw_queue_depth
, "Queue depth for each hardware queue. Default: 64");
243 static bool g_use_per_node_hctx
;
244 module_param_named(use_per_node_hctx
, g_use_per_node_hctx
, bool, S_IRUGO
);
245 MODULE_PARM_DESC(use_per_node_hctx
, "Use per-node allocation for hardware context queues. Default: false");
247 static struct nullb_device
*null_alloc_dev(void);
248 static void null_free_dev(struct nullb_device
*dev
);
249 static void null_del_dev(struct nullb
*nullb
);
250 static int null_add_dev(struct nullb_device
*dev
);
251 static void null_free_device_storage(struct nullb_device
*dev
, bool is_cache
);
253 static inline struct nullb_device
*to_nullb_device(struct config_item
*item
)
255 return item
? container_of(item
, struct nullb_device
, item
) : NULL
;
258 static inline ssize_t
nullb_device_uint_attr_show(unsigned int val
, char *page
)
260 return snprintf(page
, PAGE_SIZE
, "%u\n", val
);
263 static inline ssize_t
nullb_device_ulong_attr_show(unsigned long val
,
266 return snprintf(page
, PAGE_SIZE
, "%lu\n", val
);
269 static inline ssize_t
nullb_device_bool_attr_show(bool val
, char *page
)
271 return snprintf(page
, PAGE_SIZE
, "%u\n", val
);
274 static ssize_t
nullb_device_uint_attr_store(unsigned int *val
,
275 const char *page
, size_t count
)
280 result
= kstrtouint(page
, 0, &tmp
);
288 static ssize_t
nullb_device_ulong_attr_store(unsigned long *val
,
289 const char *page
, size_t count
)
294 result
= kstrtoul(page
, 0, &tmp
);
302 static ssize_t
nullb_device_bool_attr_store(bool *val
, const char *page
,
308 result
= kstrtobool(page
, &tmp
);
316 /* The following macro should only be used with TYPE = {uint, ulong, bool}. */
317 #define NULLB_DEVICE_ATTR(NAME, TYPE) \
319 nullb_device_##NAME##_show(struct config_item *item, char *page) \
321 return nullb_device_##TYPE##_attr_show( \
322 to_nullb_device(item)->NAME, page); \
325 nullb_device_##NAME##_store(struct config_item *item, const char *page, \
328 if (test_bit(NULLB_DEV_FL_CONFIGURED, &to_nullb_device(item)->flags)) \
330 return nullb_device_##TYPE##_attr_store( \
331 &to_nullb_device(item)->NAME, page, count); \
333 CONFIGFS_ATTR(nullb_device_, NAME);
335 NULLB_DEVICE_ATTR(size
, ulong
);
336 NULLB_DEVICE_ATTR(completion_nsec
, ulong
);
337 NULLB_DEVICE_ATTR(submit_queues
, uint
);
338 NULLB_DEVICE_ATTR(home_node
, uint
);
339 NULLB_DEVICE_ATTR(queue_mode
, uint
);
340 NULLB_DEVICE_ATTR(blocksize
, uint
);
341 NULLB_DEVICE_ATTR(irqmode
, uint
);
342 NULLB_DEVICE_ATTR(hw_queue_depth
, uint
);
343 NULLB_DEVICE_ATTR(index
, uint
);
344 NULLB_DEVICE_ATTR(use_lightnvm
, bool);
345 NULLB_DEVICE_ATTR(blocking
, bool);
346 NULLB_DEVICE_ATTR(use_per_node_hctx
, bool);
347 NULLB_DEVICE_ATTR(memory_backed
, bool);
348 NULLB_DEVICE_ATTR(discard
, bool);
349 NULLB_DEVICE_ATTR(mbps
, uint
);
350 NULLB_DEVICE_ATTR(cache_size
, ulong
);
352 static ssize_t
nullb_device_power_show(struct config_item
*item
, char *page
)
354 return nullb_device_bool_attr_show(to_nullb_device(item
)->power
, page
);
357 static ssize_t
nullb_device_power_store(struct config_item
*item
,
358 const char *page
, size_t count
)
360 struct nullb_device
*dev
= to_nullb_device(item
);
364 ret
= nullb_device_bool_attr_store(&newp
, page
, count
);
368 if (!dev
->power
&& newp
) {
369 if (test_and_set_bit(NULLB_DEV_FL_UP
, &dev
->flags
))
371 if (null_add_dev(dev
)) {
372 clear_bit(NULLB_DEV_FL_UP
, &dev
->flags
);
376 set_bit(NULLB_DEV_FL_CONFIGURED
, &dev
->flags
);
378 } else if (dev
->power
&& !newp
) {
381 null_del_dev(dev
->nullb
);
383 clear_bit(NULLB_DEV_FL_UP
, &dev
->flags
);
389 CONFIGFS_ATTR(nullb_device_
, power
);
391 static ssize_t
nullb_device_badblocks_show(struct config_item
*item
, char *page
)
393 struct nullb_device
*t_dev
= to_nullb_device(item
);
395 return badblocks_show(&t_dev
->badblocks
, page
, 0);
398 static ssize_t
nullb_device_badblocks_store(struct config_item
*item
,
399 const char *page
, size_t count
)
401 struct nullb_device
*t_dev
= to_nullb_device(item
);
402 char *orig
, *buf
, *tmp
;
406 orig
= kstrndup(page
, count
, GFP_KERNEL
);
410 buf
= strstrip(orig
);
413 if (buf
[0] != '+' && buf
[0] != '-')
415 tmp
= strchr(&buf
[1], '-');
419 ret
= kstrtoull(buf
+ 1, 0, &start
);
422 ret
= kstrtoull(tmp
+ 1, 0, &end
);
428 /* enable badblocks */
429 cmpxchg(&t_dev
->badblocks
.shift
, -1, 0);
431 ret
= badblocks_set(&t_dev
->badblocks
, start
,
434 ret
= badblocks_clear(&t_dev
->badblocks
, start
,
442 CONFIGFS_ATTR(nullb_device_
, badblocks
);
444 static struct configfs_attribute
*nullb_device_attrs
[] = {
445 &nullb_device_attr_size
,
446 &nullb_device_attr_completion_nsec
,
447 &nullb_device_attr_submit_queues
,
448 &nullb_device_attr_home_node
,
449 &nullb_device_attr_queue_mode
,
450 &nullb_device_attr_blocksize
,
451 &nullb_device_attr_irqmode
,
452 &nullb_device_attr_hw_queue_depth
,
453 &nullb_device_attr_index
,
454 &nullb_device_attr_use_lightnvm
,
455 &nullb_device_attr_blocking
,
456 &nullb_device_attr_use_per_node_hctx
,
457 &nullb_device_attr_power
,
458 &nullb_device_attr_memory_backed
,
459 &nullb_device_attr_discard
,
460 &nullb_device_attr_mbps
,
461 &nullb_device_attr_cache_size
,
462 &nullb_device_attr_badblocks
,
466 static void nullb_device_release(struct config_item
*item
)
468 struct nullb_device
*dev
= to_nullb_device(item
);
470 badblocks_exit(&dev
->badblocks
);
471 null_free_device_storage(dev
, false);
475 static struct configfs_item_operations nullb_device_ops
= {
476 .release
= nullb_device_release
,
479 static struct config_item_type nullb_device_type
= {
480 .ct_item_ops
= &nullb_device_ops
,
481 .ct_attrs
= nullb_device_attrs
,
482 .ct_owner
= THIS_MODULE
,
486 config_item
*nullb_group_make_item(struct config_group
*group
, const char *name
)
488 struct nullb_device
*dev
;
490 dev
= null_alloc_dev();
492 return ERR_PTR(-ENOMEM
);
494 config_item_init_type_name(&dev
->item
, name
, &nullb_device_type
);
500 nullb_group_drop_item(struct config_group
*group
, struct config_item
*item
)
502 struct nullb_device
*dev
= to_nullb_device(item
);
504 if (test_and_clear_bit(NULLB_DEV_FL_UP
, &dev
->flags
)) {
507 null_del_dev(dev
->nullb
);
511 config_item_put(item
);
514 static ssize_t
memb_group_features_show(struct config_item
*item
, char *page
)
516 return snprintf(page
, PAGE_SIZE
, "memory_backed,discard,bandwidth,cache,badblocks\n");
519 CONFIGFS_ATTR_RO(memb_group_
, features
);
521 static struct configfs_attribute
*nullb_group_attrs
[] = {
522 &memb_group_attr_features
,
526 static struct configfs_group_operations nullb_group_ops
= {
527 .make_item
= nullb_group_make_item
,
528 .drop_item
= nullb_group_drop_item
,
531 static struct config_item_type nullb_group_type
= {
532 .ct_group_ops
= &nullb_group_ops
,
533 .ct_attrs
= nullb_group_attrs
,
534 .ct_owner
= THIS_MODULE
,
537 static struct configfs_subsystem nullb_subsys
= {
540 .ci_namebuf
= "nullb",
541 .ci_type
= &nullb_group_type
,
546 static inline int null_cache_active(struct nullb
*nullb
)
548 return test_bit(NULLB_DEV_FL_CACHE
, &nullb
->dev
->flags
);
551 static struct nullb_device
*null_alloc_dev(void)
553 struct nullb_device
*dev
;
555 dev
= kzalloc(sizeof(*dev
), GFP_KERNEL
);
558 INIT_RADIX_TREE(&dev
->data
, GFP_ATOMIC
);
559 INIT_RADIX_TREE(&dev
->cache
, GFP_ATOMIC
);
560 if (badblocks_init(&dev
->badblocks
, 0)) {
565 dev
->size
= g_gb
* 1024;
566 dev
->completion_nsec
= g_completion_nsec
;
567 dev
->submit_queues
= g_submit_queues
;
568 dev
->home_node
= g_home_node
;
569 dev
->queue_mode
= g_queue_mode
;
570 dev
->blocksize
= g_bs
;
571 dev
->irqmode
= g_irqmode
;
572 dev
->hw_queue_depth
= g_hw_queue_depth
;
573 dev
->use_lightnvm
= g_use_lightnvm
;
574 dev
->blocking
= g_blocking
;
575 dev
->use_per_node_hctx
= g_use_per_node_hctx
;
579 static void null_free_dev(struct nullb_device
*dev
)
584 static void put_tag(struct nullb_queue
*nq
, unsigned int tag
)
586 clear_bit_unlock(tag
, nq
->tag_map
);
588 if (waitqueue_active(&nq
->wait
))
592 static unsigned int get_tag(struct nullb_queue
*nq
)
597 tag
= find_first_zero_bit(nq
->tag_map
, nq
->queue_depth
);
598 if (tag
>= nq
->queue_depth
)
600 } while (test_and_set_bit_lock(tag
, nq
->tag_map
));
605 static void free_cmd(struct nullb_cmd
*cmd
)
607 put_tag(cmd
->nq
, cmd
->tag
);
610 static enum hrtimer_restart
null_cmd_timer_expired(struct hrtimer
*timer
);
612 static struct nullb_cmd
*__alloc_cmd(struct nullb_queue
*nq
)
614 struct nullb_cmd
*cmd
;
619 cmd
= &nq
->cmds
[tag
];
622 if (nq
->dev
->irqmode
== NULL_IRQ_TIMER
) {
623 hrtimer_init(&cmd
->timer
, CLOCK_MONOTONIC
,
625 cmd
->timer
.function
= null_cmd_timer_expired
;
633 static struct nullb_cmd
*alloc_cmd(struct nullb_queue
*nq
, int can_wait
)
635 struct nullb_cmd
*cmd
;
638 cmd
= __alloc_cmd(nq
);
639 if (cmd
|| !can_wait
)
643 prepare_to_wait(&nq
->wait
, &wait
, TASK_UNINTERRUPTIBLE
);
644 cmd
= __alloc_cmd(nq
);
651 finish_wait(&nq
->wait
, &wait
);
655 static void end_cmd(struct nullb_cmd
*cmd
)
657 struct request_queue
*q
= NULL
;
658 int queue_mode
= cmd
->nq
->dev
->queue_mode
;
663 switch (queue_mode
) {
665 blk_mq_end_request(cmd
->rq
, cmd
->error
);
668 INIT_LIST_HEAD(&cmd
->rq
->queuelist
);
669 blk_end_request_all(cmd
->rq
, cmd
->error
);
672 cmd
->bio
->bi_status
= cmd
->error
;
679 /* Restart queue if needed, as we are freeing a tag */
680 if (queue_mode
== NULL_Q_RQ
&& blk_queue_stopped(q
)) {
683 spin_lock_irqsave(q
->queue_lock
, flags
);
684 blk_start_queue_async(q
);
685 spin_unlock_irqrestore(q
->queue_lock
, flags
);
689 static enum hrtimer_restart
null_cmd_timer_expired(struct hrtimer
*timer
)
691 end_cmd(container_of(timer
, struct nullb_cmd
, timer
));
693 return HRTIMER_NORESTART
;
696 static void null_cmd_end_timer(struct nullb_cmd
*cmd
)
698 ktime_t kt
= cmd
->nq
->dev
->completion_nsec
;
700 hrtimer_start(&cmd
->timer
, kt
, HRTIMER_MODE_REL
);
703 static void null_softirq_done_fn(struct request
*rq
)
705 struct nullb
*nullb
= rq
->q
->queuedata
;
707 if (nullb
->dev
->queue_mode
== NULL_Q_MQ
)
708 end_cmd(blk_mq_rq_to_pdu(rq
));
710 end_cmd(rq
->special
);
713 static struct nullb_page
*null_alloc_page(gfp_t gfp_flags
)
715 struct nullb_page
*t_page
;
717 t_page
= kmalloc(sizeof(struct nullb_page
), gfp_flags
);
721 t_page
->page
= alloc_pages(gfp_flags
, 0);
733 static void null_free_page(struct nullb_page
*t_page
)
735 __set_bit(NULLB_PAGE_FREE
, &t_page
->bitmap
);
736 if (test_bit(NULLB_PAGE_LOCK
, &t_page
->bitmap
))
738 __free_page(t_page
->page
);
742 static void null_free_sector(struct nullb
*nullb
, sector_t sector
,
745 unsigned int sector_bit
;
747 struct nullb_page
*t_page
, *ret
;
748 struct radix_tree_root
*root
;
750 root
= is_cache
? &nullb
->dev
->cache
: &nullb
->dev
->data
;
751 idx
= sector
>> PAGE_SECTORS_SHIFT
;
752 sector_bit
= (sector
& SECTOR_MASK
);
754 t_page
= radix_tree_lookup(root
, idx
);
756 __clear_bit(sector_bit
, &t_page
->bitmap
);
758 if (!t_page
->bitmap
) {
759 ret
= radix_tree_delete_item(root
, idx
, t_page
);
760 WARN_ON(ret
!= t_page
);
763 nullb
->dev
->curr_cache
-= PAGE_SIZE
;
768 static struct nullb_page
*null_radix_tree_insert(struct nullb
*nullb
, u64 idx
,
769 struct nullb_page
*t_page
, bool is_cache
)
771 struct radix_tree_root
*root
;
773 root
= is_cache
? &nullb
->dev
->cache
: &nullb
->dev
->data
;
775 if (radix_tree_insert(root
, idx
, t_page
)) {
776 null_free_page(t_page
);
777 t_page
= radix_tree_lookup(root
, idx
);
778 WARN_ON(!t_page
|| t_page
->page
->index
!= idx
);
780 nullb
->dev
->curr_cache
+= PAGE_SIZE
;
785 static void null_free_device_storage(struct nullb_device
*dev
, bool is_cache
)
787 unsigned long pos
= 0;
789 struct nullb_page
*ret
, *t_pages
[FREE_BATCH
];
790 struct radix_tree_root
*root
;
792 root
= is_cache
? &dev
->cache
: &dev
->data
;
797 nr_pages
= radix_tree_gang_lookup(root
,
798 (void **)t_pages
, pos
, FREE_BATCH
);
800 for (i
= 0; i
< nr_pages
; i
++) {
801 pos
= t_pages
[i
]->page
->index
;
802 ret
= radix_tree_delete_item(root
, pos
, t_pages
[i
]);
803 WARN_ON(ret
!= t_pages
[i
]);
808 } while (nr_pages
== FREE_BATCH
);
814 static struct nullb_page
*__null_lookup_page(struct nullb
*nullb
,
815 sector_t sector
, bool for_write
, bool is_cache
)
817 unsigned int sector_bit
;
819 struct nullb_page
*t_page
;
820 struct radix_tree_root
*root
;
822 idx
= sector
>> PAGE_SECTORS_SHIFT
;
823 sector_bit
= (sector
& SECTOR_MASK
);
825 root
= is_cache
? &nullb
->dev
->cache
: &nullb
->dev
->data
;
826 t_page
= radix_tree_lookup(root
, idx
);
827 WARN_ON(t_page
&& t_page
->page
->index
!= idx
);
829 if (t_page
&& (for_write
|| test_bit(sector_bit
, &t_page
->bitmap
)))
835 static struct nullb_page
*null_lookup_page(struct nullb
*nullb
,
836 sector_t sector
, bool for_write
, bool ignore_cache
)
838 struct nullb_page
*page
= NULL
;
841 page
= __null_lookup_page(nullb
, sector
, for_write
, true);
844 return __null_lookup_page(nullb
, sector
, for_write
, false);
847 static struct nullb_page
*null_insert_page(struct nullb
*nullb
,
848 sector_t sector
, bool ignore_cache
)
851 struct nullb_page
*t_page
;
853 t_page
= null_lookup_page(nullb
, sector
, true, ignore_cache
);
857 spin_unlock_irq(&nullb
->lock
);
859 t_page
= null_alloc_page(GFP_NOIO
);
863 if (radix_tree_preload(GFP_NOIO
))
866 spin_lock_irq(&nullb
->lock
);
867 idx
= sector
>> PAGE_SECTORS_SHIFT
;
868 t_page
->page
->index
= idx
;
869 t_page
= null_radix_tree_insert(nullb
, idx
, t_page
, !ignore_cache
);
870 radix_tree_preload_end();
874 null_free_page(t_page
);
876 spin_lock_irq(&nullb
->lock
);
877 return null_lookup_page(nullb
, sector
, true, ignore_cache
);
880 static int null_flush_cache_page(struct nullb
*nullb
, struct nullb_page
*c_page
)
885 struct nullb_page
*t_page
, *ret
;
888 idx
= c_page
->page
->index
;
890 t_page
= null_insert_page(nullb
, idx
<< PAGE_SECTORS_SHIFT
, true);
892 __clear_bit(NULLB_PAGE_LOCK
, &c_page
->bitmap
);
893 if (test_bit(NULLB_PAGE_FREE
, &c_page
->bitmap
)) {
894 null_free_page(c_page
);
895 if (t_page
&& t_page
->bitmap
== 0) {
896 ret
= radix_tree_delete_item(&nullb
->dev
->data
,
898 null_free_page(t_page
);
906 src
= kmap_atomic(c_page
->page
);
907 dst
= kmap_atomic(t_page
->page
);
909 for (i
= 0; i
< PAGE_SECTORS
;
910 i
+= (nullb
->dev
->blocksize
>> SECTOR_SHIFT
)) {
911 if (test_bit(i
, &c_page
->bitmap
)) {
912 offset
= (i
<< SECTOR_SHIFT
);
913 memcpy(dst
+ offset
, src
+ offset
,
914 nullb
->dev
->blocksize
);
915 __set_bit(i
, &t_page
->bitmap
);
922 ret
= radix_tree_delete_item(&nullb
->dev
->cache
, idx
, c_page
);
924 nullb
->dev
->curr_cache
-= PAGE_SIZE
;
929 static int null_make_cache_space(struct nullb
*nullb
, unsigned long n
)
931 int i
, err
, nr_pages
;
932 struct nullb_page
*c_pages
[FREE_BATCH
];
933 unsigned long flushed
= 0, one_round
;
936 if ((nullb
->dev
->cache_size
* 1024 * 1024) >
937 nullb
->dev
->curr_cache
+ n
|| nullb
->dev
->curr_cache
== 0)
940 nr_pages
= radix_tree_gang_lookup(&nullb
->dev
->cache
,
941 (void **)c_pages
, nullb
->cache_flush_pos
, FREE_BATCH
);
943 * nullb_flush_cache_page could unlock before using the c_pages. To
944 * avoid race, we don't allow page free
946 for (i
= 0; i
< nr_pages
; i
++) {
947 nullb
->cache_flush_pos
= c_pages
[i
]->page
->index
;
949 * We found the page which is being flushed to disk by other
952 if (test_bit(NULLB_PAGE_LOCK
, &c_pages
[i
]->bitmap
))
955 __set_bit(NULLB_PAGE_LOCK
, &c_pages
[i
]->bitmap
);
959 for (i
= 0; i
< nr_pages
; i
++) {
960 if (c_pages
[i
] == NULL
)
962 err
= null_flush_cache_page(nullb
, c_pages
[i
]);
967 flushed
+= one_round
<< PAGE_SHIFT
;
971 nullb
->cache_flush_pos
= 0;
972 if (one_round
== 0) {
973 /* give other threads a chance */
974 spin_unlock_irq(&nullb
->lock
);
975 spin_lock_irq(&nullb
->lock
);
982 static int copy_to_nullb(struct nullb
*nullb
, struct page
*source
,
983 unsigned int off
, sector_t sector
, size_t n
, bool is_fua
)
985 size_t temp
, count
= 0;
987 struct nullb_page
*t_page
;
991 temp
= min_t(size_t, nullb
->dev
->blocksize
, n
- count
);
993 if (null_cache_active(nullb
) && !is_fua
)
994 null_make_cache_space(nullb
, PAGE_SIZE
);
996 offset
= (sector
& SECTOR_MASK
) << SECTOR_SHIFT
;
997 t_page
= null_insert_page(nullb
, sector
,
998 !null_cache_active(nullb
) || is_fua
);
1002 src
= kmap_atomic(source
);
1003 dst
= kmap_atomic(t_page
->page
);
1004 memcpy(dst
+ offset
, src
+ off
+ count
, temp
);
1008 __set_bit(sector
& SECTOR_MASK
, &t_page
->bitmap
);
1011 null_free_sector(nullb
, sector
, true);
1014 sector
+= temp
>> SECTOR_SHIFT
;
1019 static int copy_from_nullb(struct nullb
*nullb
, struct page
*dest
,
1020 unsigned int off
, sector_t sector
, size_t n
)
1022 size_t temp
, count
= 0;
1023 unsigned int offset
;
1024 struct nullb_page
*t_page
;
1028 temp
= min_t(size_t, nullb
->dev
->blocksize
, n
- count
);
1030 offset
= (sector
& SECTOR_MASK
) << SECTOR_SHIFT
;
1031 t_page
= null_lookup_page(nullb
, sector
, false,
1032 !null_cache_active(nullb
));
1034 dst
= kmap_atomic(dest
);
1036 memset(dst
+ off
+ count
, 0, temp
);
1039 src
= kmap_atomic(t_page
->page
);
1040 memcpy(dst
+ off
+ count
, src
+ offset
, temp
);
1046 sector
+= temp
>> SECTOR_SHIFT
;
1051 static void null_handle_discard(struct nullb
*nullb
, sector_t sector
, size_t n
)
1055 spin_lock_irq(&nullb
->lock
);
1057 temp
= min_t(size_t, n
, nullb
->dev
->blocksize
);
1058 null_free_sector(nullb
, sector
, false);
1059 if (null_cache_active(nullb
))
1060 null_free_sector(nullb
, sector
, true);
1061 sector
+= temp
>> SECTOR_SHIFT
;
1064 spin_unlock_irq(&nullb
->lock
);
1067 static int null_handle_flush(struct nullb
*nullb
)
1071 if (!null_cache_active(nullb
))
1074 spin_lock_irq(&nullb
->lock
);
1076 err
= null_make_cache_space(nullb
,
1077 nullb
->dev
->cache_size
* 1024 * 1024);
1078 if (err
|| nullb
->dev
->curr_cache
== 0)
1082 WARN_ON(!radix_tree_empty(&nullb
->dev
->cache
));
1083 spin_unlock_irq(&nullb
->lock
);
1087 static int null_transfer(struct nullb
*nullb
, struct page
*page
,
1088 unsigned int len
, unsigned int off
, bool is_write
, sector_t sector
,
1094 err
= copy_from_nullb(nullb
, page
, off
, sector
, len
);
1095 flush_dcache_page(page
);
1097 flush_dcache_page(page
);
1098 err
= copy_to_nullb(nullb
, page
, off
, sector
, len
, is_fua
);
1104 static int null_handle_rq(struct nullb_cmd
*cmd
)
1106 struct request
*rq
= cmd
->rq
;
1107 struct nullb
*nullb
= cmd
->nq
->dev
->nullb
;
1111 struct req_iterator iter
;
1112 struct bio_vec bvec
;
1114 sector
= blk_rq_pos(rq
);
1116 if (req_op(rq
) == REQ_OP_DISCARD
) {
1117 null_handle_discard(nullb
, sector
, blk_rq_bytes(rq
));
1121 spin_lock_irq(&nullb
->lock
);
1122 rq_for_each_segment(bvec
, rq
, iter
) {
1124 err
= null_transfer(nullb
, bvec
.bv_page
, len
, bvec
.bv_offset
,
1125 op_is_write(req_op(rq
)), sector
,
1126 req_op(rq
) & REQ_FUA
);
1128 spin_unlock_irq(&nullb
->lock
);
1131 sector
+= len
>> SECTOR_SHIFT
;
1133 spin_unlock_irq(&nullb
->lock
);
1138 static int null_handle_bio(struct nullb_cmd
*cmd
)
1140 struct bio
*bio
= cmd
->bio
;
1141 struct nullb
*nullb
= cmd
->nq
->dev
->nullb
;
1145 struct bio_vec bvec
;
1146 struct bvec_iter iter
;
1148 sector
= bio
->bi_iter
.bi_sector
;
1150 if (bio_op(bio
) == REQ_OP_DISCARD
) {
1151 null_handle_discard(nullb
, sector
,
1152 bio_sectors(bio
) << SECTOR_SHIFT
);
1156 spin_lock_irq(&nullb
->lock
);
1157 bio_for_each_segment(bvec
, bio
, iter
) {
1159 err
= null_transfer(nullb
, bvec
.bv_page
, len
, bvec
.bv_offset
,
1160 op_is_write(bio_op(bio
)), sector
,
1161 bio_op(bio
) & REQ_FUA
);
1163 spin_unlock_irq(&nullb
->lock
);
1166 sector
+= len
>> SECTOR_SHIFT
;
1168 spin_unlock_irq(&nullb
->lock
);
1172 static void null_stop_queue(struct nullb
*nullb
)
1174 struct request_queue
*q
= nullb
->q
;
1176 if (nullb
->dev
->queue_mode
== NULL_Q_MQ
)
1177 blk_mq_stop_hw_queues(q
);
1179 spin_lock_irq(q
->queue_lock
);
1181 spin_unlock_irq(q
->queue_lock
);
1185 static void null_restart_queue_async(struct nullb
*nullb
)
1187 struct request_queue
*q
= nullb
->q
;
1188 unsigned long flags
;
1190 if (nullb
->dev
->queue_mode
== NULL_Q_MQ
)
1191 blk_mq_start_stopped_hw_queues(q
, true);
1193 spin_lock_irqsave(q
->queue_lock
, flags
);
1194 blk_start_queue_async(q
);
1195 spin_unlock_irqrestore(q
->queue_lock
, flags
);
1199 static blk_status_t
null_handle_cmd(struct nullb_cmd
*cmd
)
1201 struct nullb_device
*dev
= cmd
->nq
->dev
;
1202 struct nullb
*nullb
= dev
->nullb
;
1205 if (test_bit(NULLB_DEV_FL_THROTTLED
, &dev
->flags
)) {
1206 struct request
*rq
= cmd
->rq
;
1208 if (!hrtimer_active(&nullb
->bw_timer
))
1209 hrtimer_restart(&nullb
->bw_timer
);
1211 if (atomic_long_sub_return(blk_rq_bytes(rq
),
1212 &nullb
->cur_bytes
) < 0) {
1213 null_stop_queue(nullb
);
1214 /* race with timer */
1215 if (atomic_long_read(&nullb
->cur_bytes
) > 0)
1216 null_restart_queue_async(nullb
);
1217 if (dev
->queue_mode
== NULL_Q_RQ
) {
1218 struct request_queue
*q
= nullb
->q
;
1220 spin_lock_irq(q
->queue_lock
);
1221 rq
->rq_flags
|= RQF_DONTPREP
;
1222 blk_requeue_request(q
, rq
);
1223 spin_unlock_irq(q
->queue_lock
);
1226 /* requeue request */
1227 return BLK_STS_RESOURCE
;
1231 if (nullb
->dev
->badblocks
.shift
!= -1) {
1233 sector_t sector
, size
, first_bad
;
1234 bool is_flush
= true;
1236 if (dev
->queue_mode
== NULL_Q_BIO
&&
1237 bio_op(cmd
->bio
) != REQ_OP_FLUSH
) {
1239 sector
= cmd
->bio
->bi_iter
.bi_sector
;
1240 size
= bio_sectors(cmd
->bio
);
1242 if (dev
->queue_mode
!= NULL_Q_BIO
&&
1243 req_op(cmd
->rq
) != REQ_OP_FLUSH
) {
1245 sector
= blk_rq_pos(cmd
->rq
);
1246 size
= blk_rq_sectors(cmd
->rq
);
1248 if (!is_flush
&& badblocks_check(&nullb
->dev
->badblocks
, sector
,
1249 size
, &first_bad
, &bad_sectors
)) {
1250 cmd
->error
= BLK_STS_IOERR
;
1255 if (dev
->memory_backed
) {
1256 if (dev
->queue_mode
== NULL_Q_BIO
) {
1257 if (bio_op(cmd
->bio
) == REQ_OP_FLUSH
)
1258 err
= null_handle_flush(nullb
);
1260 err
= null_handle_bio(cmd
);
1262 if (req_op(cmd
->rq
) == REQ_OP_FLUSH
)
1263 err
= null_handle_flush(nullb
);
1265 err
= null_handle_rq(cmd
);
1268 cmd
->error
= errno_to_blk_status(err
);
1270 /* Complete IO by inline, softirq or timer */
1271 switch (dev
->irqmode
) {
1272 case NULL_IRQ_SOFTIRQ
:
1273 switch (dev
->queue_mode
) {
1275 blk_mq_complete_request(cmd
->rq
);
1278 blk_complete_request(cmd
->rq
);
1282 * XXX: no proper submitting cpu information available.
1291 case NULL_IRQ_TIMER
:
1292 null_cmd_end_timer(cmd
);
1298 static enum hrtimer_restart
nullb_bwtimer_fn(struct hrtimer
*timer
)
1300 struct nullb
*nullb
= container_of(timer
, struct nullb
, bw_timer
);
1301 ktime_t timer_interval
= ktime_set(0, TIMER_INTERVAL
);
1302 unsigned int mbps
= nullb
->dev
->mbps
;
1304 if (atomic_long_read(&nullb
->cur_bytes
) == mb_per_tick(mbps
))
1305 return HRTIMER_NORESTART
;
1307 atomic_long_set(&nullb
->cur_bytes
, mb_per_tick(mbps
));
1308 null_restart_queue_async(nullb
);
1310 hrtimer_forward_now(&nullb
->bw_timer
, timer_interval
);
1312 return HRTIMER_RESTART
;
1315 static void nullb_setup_bwtimer(struct nullb
*nullb
)
1317 ktime_t timer_interval
= ktime_set(0, TIMER_INTERVAL
);
1319 hrtimer_init(&nullb
->bw_timer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL
);
1320 nullb
->bw_timer
.function
= nullb_bwtimer_fn
;
1321 atomic_long_set(&nullb
->cur_bytes
, mb_per_tick(nullb
->dev
->mbps
));
1322 hrtimer_start(&nullb
->bw_timer
, timer_interval
, HRTIMER_MODE_REL
);
1325 static struct nullb_queue
*nullb_to_queue(struct nullb
*nullb
)
1329 if (nullb
->nr_queues
!= 1)
1330 index
= raw_smp_processor_id() / ((nr_cpu_ids
+ nullb
->nr_queues
- 1) / nullb
->nr_queues
);
1332 return &nullb
->queues
[index
];
1335 static blk_qc_t
null_queue_bio(struct request_queue
*q
, struct bio
*bio
)
1337 struct nullb
*nullb
= q
->queuedata
;
1338 struct nullb_queue
*nq
= nullb_to_queue(nullb
);
1339 struct nullb_cmd
*cmd
;
1341 cmd
= alloc_cmd(nq
, 1);
1344 null_handle_cmd(cmd
);
1345 return BLK_QC_T_NONE
;
1348 static int null_rq_prep_fn(struct request_queue
*q
, struct request
*req
)
1350 struct nullb
*nullb
= q
->queuedata
;
1351 struct nullb_queue
*nq
= nullb_to_queue(nullb
);
1352 struct nullb_cmd
*cmd
;
1354 cmd
= alloc_cmd(nq
, 0);
1362 return BLKPREP_DEFER
;
1365 static void null_request_fn(struct request_queue
*q
)
1369 while ((rq
= blk_fetch_request(q
)) != NULL
) {
1370 struct nullb_cmd
*cmd
= rq
->special
;
1372 spin_unlock_irq(q
->queue_lock
);
1373 null_handle_cmd(cmd
);
1374 spin_lock_irq(q
->queue_lock
);
1378 static blk_status_t
null_queue_rq(struct blk_mq_hw_ctx
*hctx
,
1379 const struct blk_mq_queue_data
*bd
)
1381 struct nullb_cmd
*cmd
= blk_mq_rq_to_pdu(bd
->rq
);
1382 struct nullb_queue
*nq
= hctx
->driver_data
;
1384 might_sleep_if(hctx
->flags
& BLK_MQ_F_BLOCKING
);
1386 if (nq
->dev
->irqmode
== NULL_IRQ_TIMER
) {
1387 hrtimer_init(&cmd
->timer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL
);
1388 cmd
->timer
.function
= null_cmd_timer_expired
;
1393 blk_mq_start_request(bd
->rq
);
1395 return null_handle_cmd(cmd
);
1398 static const struct blk_mq_ops null_mq_ops
= {
1399 .queue_rq
= null_queue_rq
,
1400 .complete
= null_softirq_done_fn
,
1403 static void cleanup_queue(struct nullb_queue
*nq
)
1409 static void cleanup_queues(struct nullb
*nullb
)
1413 for (i
= 0; i
< nullb
->nr_queues
; i
++)
1414 cleanup_queue(&nullb
->queues
[i
]);
1416 kfree(nullb
->queues
);
1421 static void null_lnvm_end_io(struct request
*rq
, blk_status_t status
)
1423 struct nvm_rq
*rqd
= rq
->end_io_data
;
1425 /* XXX: lighnvm core seems to expect NVM_RSP_* values here.. */
1426 rqd
->error
= status
? -EIO
: 0;
1429 blk_put_request(rq
);
1432 static int null_lnvm_submit_io(struct nvm_dev
*dev
, struct nvm_rq
*rqd
)
1434 struct request_queue
*q
= dev
->q
;
1436 struct bio
*bio
= rqd
->bio
;
1438 rq
= blk_mq_alloc_request(q
,
1439 op_is_write(bio_op(bio
)) ? REQ_OP_DRV_OUT
: REQ_OP_DRV_IN
, 0);
1443 blk_init_request_from_bio(rq
, bio
);
1445 rq
->end_io_data
= rqd
;
1447 blk_execute_rq_nowait(q
, NULL
, rq
, 0, null_lnvm_end_io
);
1452 static int null_lnvm_id(struct nvm_dev
*dev
, struct nvm_id
*id
)
1454 struct nullb
*nullb
= dev
->q
->queuedata
;
1455 sector_t size
= (sector_t
)nullb
->dev
->size
* 1024 * 1024ULL;
1457 struct nvm_id_group
*grp
;
1464 id
->ppaf
.blk_offset
= 0;
1465 id
->ppaf
.blk_len
= 16;
1466 id
->ppaf
.pg_offset
= 16;
1467 id
->ppaf
.pg_len
= 16;
1468 id
->ppaf
.sect_offset
= 32;
1469 id
->ppaf
.sect_len
= 8;
1470 id
->ppaf
.pln_offset
= 40;
1471 id
->ppaf
.pln_len
= 8;
1472 id
->ppaf
.lun_offset
= 48;
1473 id
->ppaf
.lun_len
= 8;
1474 id
->ppaf
.ch_offset
= 56;
1475 id
->ppaf
.ch_len
= 8;
1477 sector_div(size
, nullb
->dev
->blocksize
); /* convert size to pages */
1478 size
>>= 8; /* concert size to pgs pr blk */
1486 grp
->num_lun
= size
+ 1;
1487 sector_div(blksize
, grp
->num_lun
);
1488 grp
->num_blk
= blksize
;
1491 grp
->fpg_sz
= nullb
->dev
->blocksize
;
1492 grp
->csecs
= nullb
->dev
->blocksize
;
1497 grp
->tbet
= 1500000;
1498 grp
->tbem
= 1500000;
1499 grp
->mpos
= 0x010101; /* single plane rwe */
1500 grp
->cpar
= nullb
->dev
->hw_queue_depth
;
1505 static void *null_lnvm_create_dma_pool(struct nvm_dev
*dev
, char *name
)
1507 mempool_t
*virtmem_pool
;
1509 virtmem_pool
= mempool_create_slab_pool(64, ppa_cache
);
1510 if (!virtmem_pool
) {
1511 pr_err("null_blk: Unable to create virtual memory pool\n");
1515 return virtmem_pool
;
1518 static void null_lnvm_destroy_dma_pool(void *pool
)
1520 mempool_destroy(pool
);
1523 static void *null_lnvm_dev_dma_alloc(struct nvm_dev
*dev
, void *pool
,
1524 gfp_t mem_flags
, dma_addr_t
*dma_handler
)
1526 return mempool_alloc(pool
, mem_flags
);
1529 static void null_lnvm_dev_dma_free(void *pool
, void *entry
,
1530 dma_addr_t dma_handler
)
1532 mempool_free(entry
, pool
);
1535 static struct nvm_dev_ops null_lnvm_dev_ops
= {
1536 .identity
= null_lnvm_id
,
1537 .submit_io
= null_lnvm_submit_io
,
1539 .create_dma_pool
= null_lnvm_create_dma_pool
,
1540 .destroy_dma_pool
= null_lnvm_destroy_dma_pool
,
1541 .dev_dma_alloc
= null_lnvm_dev_dma_alloc
,
1542 .dev_dma_free
= null_lnvm_dev_dma_free
,
1544 /* Simulate nvme protocol restriction */
1545 .max_phys_sect
= 64,
1548 static int null_nvm_register(struct nullb
*nullb
)
1550 struct nvm_dev
*dev
;
1553 dev
= nvm_alloc_dev(0);
1558 memcpy(dev
->name
, nullb
->disk_name
, DISK_NAME_LEN
);
1559 dev
->ops
= &null_lnvm_dev_ops
;
1561 rv
= nvm_register(dev
);
1570 static void null_nvm_unregister(struct nullb
*nullb
)
1572 nvm_unregister(nullb
->ndev
);
1575 static int null_nvm_register(struct nullb
*nullb
)
1577 pr_err("null_blk: CONFIG_NVM needs to be enabled for LightNVM\n");
1580 static void null_nvm_unregister(struct nullb
*nullb
) {}
1581 #endif /* CONFIG_NVM */
1583 static void null_del_dev(struct nullb
*nullb
)
1585 struct nullb_device
*dev
= nullb
->dev
;
1587 ida_simple_remove(&nullb_indexes
, nullb
->index
);
1589 list_del_init(&nullb
->list
);
1591 if (dev
->use_lightnvm
)
1592 null_nvm_unregister(nullb
);
1594 del_gendisk(nullb
->disk
);
1596 if (test_bit(NULLB_DEV_FL_THROTTLED
, &nullb
->dev
->flags
)) {
1597 hrtimer_cancel(&nullb
->bw_timer
);
1598 atomic_long_set(&nullb
->cur_bytes
, LONG_MAX
);
1599 null_restart_queue_async(nullb
);
1602 blk_cleanup_queue(nullb
->q
);
1603 if (dev
->queue_mode
== NULL_Q_MQ
&&
1604 nullb
->tag_set
== &nullb
->__tag_set
)
1605 blk_mq_free_tag_set(nullb
->tag_set
);
1606 if (!dev
->use_lightnvm
)
1607 put_disk(nullb
->disk
);
1608 cleanup_queues(nullb
);
1609 if (null_cache_active(nullb
))
1610 null_free_device_storage(nullb
->dev
, true);
1615 static void null_config_discard(struct nullb
*nullb
)
1617 if (nullb
->dev
->discard
== false)
1619 nullb
->q
->limits
.discard_granularity
= nullb
->dev
->blocksize
;
1620 nullb
->q
->limits
.discard_alignment
= nullb
->dev
->blocksize
;
1621 blk_queue_max_discard_sectors(nullb
->q
, UINT_MAX
>> 9);
1622 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD
, nullb
->q
);
1625 static int null_open(struct block_device
*bdev
, fmode_t mode
)
1630 static void null_release(struct gendisk
*disk
, fmode_t mode
)
1634 static const struct block_device_operations null_fops
= {
1635 .owner
= THIS_MODULE
,
1637 .release
= null_release
,
1640 static void null_init_queue(struct nullb
*nullb
, struct nullb_queue
*nq
)
1645 init_waitqueue_head(&nq
->wait
);
1646 nq
->queue_depth
= nullb
->queue_depth
;
1647 nq
->dev
= nullb
->dev
;
1650 static void null_init_queues(struct nullb
*nullb
)
1652 struct request_queue
*q
= nullb
->q
;
1653 struct blk_mq_hw_ctx
*hctx
;
1654 struct nullb_queue
*nq
;
1657 queue_for_each_hw_ctx(q
, hctx
, i
) {
1658 if (!hctx
->nr_ctx
|| !hctx
->tags
)
1660 nq
= &nullb
->queues
[i
];
1661 hctx
->driver_data
= nq
;
1662 null_init_queue(nullb
, nq
);
1667 static int setup_commands(struct nullb_queue
*nq
)
1669 struct nullb_cmd
*cmd
;
1672 nq
->cmds
= kzalloc(nq
->queue_depth
* sizeof(*cmd
), GFP_KERNEL
);
1676 tag_size
= ALIGN(nq
->queue_depth
, BITS_PER_LONG
) / BITS_PER_LONG
;
1677 nq
->tag_map
= kzalloc(tag_size
* sizeof(unsigned long), GFP_KERNEL
);
1683 for (i
= 0; i
< nq
->queue_depth
; i
++) {
1685 INIT_LIST_HEAD(&cmd
->list
);
1686 cmd
->ll_list
.next
= NULL
;
1693 static int setup_queues(struct nullb
*nullb
)
1695 nullb
->queues
= kzalloc(nullb
->dev
->submit_queues
*
1696 sizeof(struct nullb_queue
), GFP_KERNEL
);
1700 nullb
->nr_queues
= 0;
1701 nullb
->queue_depth
= nullb
->dev
->hw_queue_depth
;
1706 static int init_driver_queues(struct nullb
*nullb
)
1708 struct nullb_queue
*nq
;
1711 for (i
= 0; i
< nullb
->dev
->submit_queues
; i
++) {
1712 nq
= &nullb
->queues
[i
];
1714 null_init_queue(nullb
, nq
);
1716 ret
= setup_commands(nq
);
1724 static int null_gendisk_register(struct nullb
*nullb
)
1726 struct gendisk
*disk
;
1729 disk
= nullb
->disk
= alloc_disk_node(1, nullb
->dev
->home_node
);
1732 size
= (sector_t
)nullb
->dev
->size
* 1024 * 1024ULL;
1733 set_capacity(disk
, size
>> 9);
1735 disk
->flags
|= GENHD_FL_EXT_DEVT
| GENHD_FL_SUPPRESS_PARTITION_INFO
;
1736 disk
->major
= null_major
;
1737 disk
->first_minor
= nullb
->index
;
1738 disk
->fops
= &null_fops
;
1739 disk
->private_data
= nullb
;
1740 disk
->queue
= nullb
->q
;
1741 strncpy(disk
->disk_name
, nullb
->disk_name
, DISK_NAME_LEN
);
1747 static int null_init_tag_set(struct nullb
*nullb
, struct blk_mq_tag_set
*set
)
1749 set
->ops
= &null_mq_ops
;
1750 set
->nr_hw_queues
= nullb
? nullb
->dev
->submit_queues
:
1752 set
->queue_depth
= nullb
? nullb
->dev
->hw_queue_depth
:
1754 set
->numa_node
= nullb
? nullb
->dev
->home_node
: g_home_node
;
1755 set
->cmd_size
= sizeof(struct nullb_cmd
);
1756 set
->flags
= BLK_MQ_F_SHOULD_MERGE
;
1757 set
->driver_data
= NULL
;
1759 if ((nullb
&& nullb
->dev
->blocking
) || g_blocking
)
1760 set
->flags
|= BLK_MQ_F_BLOCKING
;
1762 return blk_mq_alloc_tag_set(set
);
1765 static void null_validate_conf(struct nullb_device
*dev
)
1767 dev
->blocksize
= round_down(dev
->blocksize
, 512);
1768 dev
->blocksize
= clamp_t(unsigned int, dev
->blocksize
, 512, 4096);
1769 if (dev
->use_lightnvm
&& dev
->blocksize
!= 4096)
1770 dev
->blocksize
= 4096;
1772 if (dev
->use_lightnvm
&& dev
->queue_mode
!= NULL_Q_MQ
)
1773 dev
->queue_mode
= NULL_Q_MQ
;
1775 if (dev
->queue_mode
== NULL_Q_MQ
&& dev
->use_per_node_hctx
) {
1776 if (dev
->submit_queues
!= nr_online_nodes
)
1777 dev
->submit_queues
= nr_online_nodes
;
1778 } else if (dev
->submit_queues
> nr_cpu_ids
)
1779 dev
->submit_queues
= nr_cpu_ids
;
1780 else if (dev
->submit_queues
== 0)
1781 dev
->submit_queues
= 1;
1783 dev
->queue_mode
= min_t(unsigned int, dev
->queue_mode
, NULL_Q_MQ
);
1784 dev
->irqmode
= min_t(unsigned int, dev
->irqmode
, NULL_IRQ_TIMER
);
1786 /* Do memory allocation, so set blocking */
1787 if (dev
->memory_backed
)
1788 dev
->blocking
= true;
1789 else /* cache is meaningless */
1790 dev
->cache_size
= 0;
1791 dev
->cache_size
= min_t(unsigned long, ULONG_MAX
/ 1024 / 1024,
1793 dev
->mbps
= min_t(unsigned int, 1024 * 40, dev
->mbps
);
1794 /* can not stop a queue */
1795 if (dev
->queue_mode
== NULL_Q_BIO
)
1799 static int null_add_dev(struct nullb_device
*dev
)
1801 struct nullb
*nullb
;
1804 null_validate_conf(dev
);
1806 nullb
= kzalloc_node(sizeof(*nullb
), GFP_KERNEL
, dev
->home_node
);
1814 spin_lock_init(&nullb
->lock
);
1816 rv
= setup_queues(nullb
);
1818 goto out_free_nullb
;
1820 if (dev
->queue_mode
== NULL_Q_MQ
) {
1822 nullb
->tag_set
= &tag_set
;
1825 nullb
->tag_set
= &nullb
->__tag_set
;
1826 rv
= null_init_tag_set(nullb
, nullb
->tag_set
);
1830 goto out_cleanup_queues
;
1832 nullb
->q
= blk_mq_init_queue(nullb
->tag_set
);
1833 if (IS_ERR(nullb
->q
)) {
1835 goto out_cleanup_tags
;
1837 null_init_queues(nullb
);
1838 } else if (dev
->queue_mode
== NULL_Q_BIO
) {
1839 nullb
->q
= blk_alloc_queue_node(GFP_KERNEL
, dev
->home_node
);
1842 goto out_cleanup_queues
;
1844 blk_queue_make_request(nullb
->q
, null_queue_bio
);
1845 rv
= init_driver_queues(nullb
);
1847 goto out_cleanup_blk_queue
;
1849 nullb
->q
= blk_init_queue_node(null_request_fn
, &nullb
->lock
,
1853 goto out_cleanup_queues
;
1855 blk_queue_prep_rq(nullb
->q
, null_rq_prep_fn
);
1856 blk_queue_softirq_done(nullb
->q
, null_softirq_done_fn
);
1857 rv
= init_driver_queues(nullb
);
1859 goto out_cleanup_blk_queue
;
1863 set_bit(NULLB_DEV_FL_THROTTLED
, &dev
->flags
);
1864 nullb_setup_bwtimer(nullb
);
1867 if (dev
->cache_size
> 0) {
1868 set_bit(NULLB_DEV_FL_CACHE
, &nullb
->dev
->flags
);
1869 blk_queue_write_cache(nullb
->q
, true, true);
1870 blk_queue_flush_queueable(nullb
->q
, true);
1873 nullb
->q
->queuedata
= nullb
;
1874 queue_flag_set_unlocked(QUEUE_FLAG_NONROT
, nullb
->q
);
1875 queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM
, nullb
->q
);
1878 nullb
->index
= ida_simple_get(&nullb_indexes
, 0, 0, GFP_KERNEL
);
1879 dev
->index
= nullb
->index
;
1880 mutex_unlock(&lock
);
1882 blk_queue_logical_block_size(nullb
->q
, dev
->blocksize
);
1883 blk_queue_physical_block_size(nullb
->q
, dev
->blocksize
);
1885 null_config_discard(nullb
);
1887 sprintf(nullb
->disk_name
, "nullb%d", nullb
->index
);
1889 if (dev
->use_lightnvm
)
1890 rv
= null_nvm_register(nullb
);
1892 rv
= null_gendisk_register(nullb
);
1895 goto out_cleanup_blk_queue
;
1898 list_add_tail(&nullb
->list
, &nullb_list
);
1899 mutex_unlock(&lock
);
1902 out_cleanup_blk_queue
:
1903 blk_cleanup_queue(nullb
->q
);
1905 if (dev
->queue_mode
== NULL_Q_MQ
&& nullb
->tag_set
== &nullb
->__tag_set
)
1906 blk_mq_free_tag_set(nullb
->tag_set
);
1908 cleanup_queues(nullb
);
1915 static int __init
null_init(void)
1919 struct nullb
*nullb
;
1920 struct nullb_device
*dev
;
1922 /* check for nullb_page.bitmap */
1923 if (sizeof(unsigned long) * 8 - 2 < (PAGE_SIZE
>> SECTOR_SHIFT
))
1926 if (g_bs
> PAGE_SIZE
) {
1927 pr_warn("null_blk: invalid block size\n");
1928 pr_warn("null_blk: defaults block size to %lu\n", PAGE_SIZE
);
1932 if (g_use_lightnvm
&& g_bs
!= 4096) {
1933 pr_warn("null_blk: LightNVM only supports 4k block size\n");
1934 pr_warn("null_blk: defaults block size to 4k\n");
1938 if (g_use_lightnvm
&& g_queue_mode
!= NULL_Q_MQ
) {
1939 pr_warn("null_blk: LightNVM only supported for blk-mq\n");
1940 pr_warn("null_blk: defaults queue mode to blk-mq\n");
1941 g_queue_mode
= NULL_Q_MQ
;
1944 if (g_queue_mode
== NULL_Q_MQ
&& g_use_per_node_hctx
) {
1945 if (g_submit_queues
!= nr_online_nodes
) {
1946 pr_warn("null_blk: submit_queues param is set to %u.\n",
1948 g_submit_queues
= nr_online_nodes
;
1950 } else if (g_submit_queues
> nr_cpu_ids
)
1951 g_submit_queues
= nr_cpu_ids
;
1952 else if (g_submit_queues
<= 0)
1953 g_submit_queues
= 1;
1955 if (g_queue_mode
== NULL_Q_MQ
&& shared_tags
) {
1956 ret
= null_init_tag_set(NULL
, &tag_set
);
1961 config_group_init(&nullb_subsys
.su_group
);
1962 mutex_init(&nullb_subsys
.su_mutex
);
1964 ret
= configfs_register_subsystem(&nullb_subsys
);
1970 null_major
= register_blkdev(0, "nullb");
1971 if (null_major
< 0) {
1976 if (g_use_lightnvm
) {
1977 ppa_cache
= kmem_cache_create("ppa_cache", 64 * sizeof(u64
),
1980 pr_err("null_blk: unable to create ppa cache\n");
1986 for (i
= 0; i
< nr_devices
; i
++) {
1987 dev
= null_alloc_dev();
1990 ret
= null_add_dev(dev
);
1997 pr_info("null: module loaded\n");
2001 while (!list_empty(&nullb_list
)) {
2002 nullb
= list_entry(nullb_list
.next
, struct nullb
, list
);
2004 null_del_dev(nullb
);
2007 kmem_cache_destroy(ppa_cache
);
2009 unregister_blkdev(null_major
, "nullb");
2011 configfs_unregister_subsystem(&nullb_subsys
);
2013 if (g_queue_mode
== NULL_Q_MQ
&& shared_tags
)
2014 blk_mq_free_tag_set(&tag_set
);
2018 static void __exit
null_exit(void)
2020 struct nullb
*nullb
;
2022 configfs_unregister_subsystem(&nullb_subsys
);
2024 unregister_blkdev(null_major
, "nullb");
2027 while (!list_empty(&nullb_list
)) {
2028 struct nullb_device
*dev
;
2030 nullb
= list_entry(nullb_list
.next
, struct nullb
, list
);
2032 null_del_dev(nullb
);
2035 mutex_unlock(&lock
);
2037 if (g_queue_mode
== NULL_Q_MQ
&& shared_tags
)
2038 blk_mq_free_tag_set(&tag_set
);
2040 kmem_cache_destroy(ppa_cache
);
2043 module_init(null_init
);
2044 module_exit(null_exit
);
2046 MODULE_AUTHOR("Jens Axboe <axboe@kernel.dk>");
2047 MODULE_LICENSE("GPL");