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1/*
2 * Copyright (C) 2001, 2002 Sistina Software (UK) Limited.
3 * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
4 *
5 * This file is released under the GPL.
6 */
7
8#include "dm.h"
9#include "dm-uevent.h"
10
11#include <linux/init.h>
12#include <linux/module.h>
13#include <linux/mutex.h>
14#include <linux/moduleparam.h>
15#include <linux/blkpg.h>
16#include <linux/bio.h>
17#include <linux/mempool.h>
18#include <linux/slab.h>
19#include <linux/idr.h>
20#include <linux/hdreg.h>
21#include <linux/delay.h>
22#include <linux/wait.h>
23#include <linux/kthread.h>
24#include <linux/ktime.h>
25#include <linux/elevator.h> /* for rq_end_sector() */
26#include <linux/blk-mq.h>
27#include <linux/pr.h>
28
29#include <trace/events/block.h>
30
31#define DM_MSG_PREFIX "core"
32
33#ifdef CONFIG_PRINTK
34/*
35 * ratelimit state to be used in DMXXX_LIMIT().
36 */
37DEFINE_RATELIMIT_STATE(dm_ratelimit_state,
38 DEFAULT_RATELIMIT_INTERVAL,
39 DEFAULT_RATELIMIT_BURST);
40EXPORT_SYMBOL(dm_ratelimit_state);
41#endif
42
43/*
44 * Cookies are numeric values sent with CHANGE and REMOVE
45 * uevents while resuming, removing or renaming the device.
46 */
47#define DM_COOKIE_ENV_VAR_NAME "DM_COOKIE"
48#define DM_COOKIE_LENGTH 24
49
50static const char *_name = DM_NAME;
51
52static unsigned int major = 0;
53static unsigned int _major = 0;
54
55static DEFINE_IDR(_minor_idr);
56
57static DEFINE_SPINLOCK(_minor_lock);
58
59static void do_deferred_remove(struct work_struct *w);
60
61static DECLARE_WORK(deferred_remove_work, do_deferred_remove);
62
63static struct workqueue_struct *deferred_remove_workqueue;
64
65/*
66 * For bio-based dm.
67 * One of these is allocated per bio.
68 */
69struct dm_io {
70 struct mapped_device *md;
71 int error;
72 atomic_t io_count;
73 struct bio *bio;
74 unsigned long start_time;
75 spinlock_t endio_lock;
76 struct dm_stats_aux stats_aux;
77};
78
79/*
80 * For request-based dm.
81 * One of these is allocated per request.
82 */
83struct dm_rq_target_io {
84 struct mapped_device *md;
85 struct dm_target *ti;
86 struct request *orig, *clone;
87 struct kthread_work work;
88 int error;
89 union map_info info;
90 struct dm_stats_aux stats_aux;
91 unsigned long duration_jiffies;
92 unsigned n_sectors;
93};
94
95/*
96 * For request-based dm - the bio clones we allocate are embedded in these
97 * structs.
98 *
99 * We allocate these with bio_alloc_bioset, using the front_pad parameter when
100 * the bioset is created - this means the bio has to come at the end of the
101 * struct.
102 */
103struct dm_rq_clone_bio_info {
104 struct bio *orig;
105 struct dm_rq_target_io *tio;
106 struct bio clone;
107};
108
109#define MINOR_ALLOCED ((void *)-1)
110
111/*
112 * Bits for the md->flags field.
113 */
114#define DMF_BLOCK_IO_FOR_SUSPEND 0
115#define DMF_SUSPENDED 1
116#define DMF_FROZEN 2
117#define DMF_FREEING 3
118#define DMF_DELETING 4
119#define DMF_NOFLUSH_SUSPENDING 5
120#define DMF_DEFERRED_REMOVE 6
121#define DMF_SUSPENDED_INTERNALLY 7
122
123/*
124 * Work processed by per-device workqueue.
125 */
126struct mapped_device {
127 struct srcu_struct io_barrier;
128 struct mutex suspend_lock;
129
130 /*
131 * The current mapping (struct dm_table *).
132 * Use dm_get_live_table{_fast} or take suspend_lock for
133 * dereference.
134 */
135 void __rcu *map;
136
137 struct list_head table_devices;
138 struct mutex table_devices_lock;
139
140 unsigned long flags;
141
142 struct request_queue *queue;
143 int numa_node_id;
144
145 unsigned type;
146 /* Protect queue and type against concurrent access. */
147 struct mutex type_lock;
148
149 atomic_t holders;
150 atomic_t open_count;
151
152 struct dm_target *immutable_target;
153 struct target_type *immutable_target_type;
154
155 struct gendisk *disk;
156 char name[16];
157
158 void *interface_ptr;
159
160 /*
161 * A list of ios that arrived while we were suspended.
162 */
163 atomic_t pending[2];
164 wait_queue_head_t wait;
165 struct work_struct work;
166 spinlock_t deferred_lock;
167 struct bio_list deferred;
168
169 /*
170 * Event handling.
171 */
172 wait_queue_head_t eventq;
173 atomic_t event_nr;
174 atomic_t uevent_seq;
175 struct list_head uevent_list;
176 spinlock_t uevent_lock; /* Protect access to uevent_list */
177
178 /* the number of internal suspends */
179 unsigned internal_suspend_count;
180
181 /*
182 * Processing queue (flush)
183 */
184 struct workqueue_struct *wq;
185
186 /*
187 * io objects are allocated from here.
188 */
189 mempool_t *io_pool;
190 mempool_t *rq_pool;
191
192 struct bio_set *bs;
193
194 /*
195 * freeze/thaw support require holding onto a super block
196 */
197 struct super_block *frozen_sb;
198
199 /* forced geometry settings */
200 struct hd_geometry geometry;
201
202 struct block_device *bdev;
203
204 /* kobject and completion */
205 struct dm_kobject_holder kobj_holder;
206
207 /* zero-length flush that will be cloned and submitted to targets */
208 struct bio flush_bio;
209
210 struct dm_stats stats;
211
212 struct kthread_worker kworker;
213 struct task_struct *kworker_task;
214
215 /* for request-based merge heuristic in dm_request_fn() */
216 unsigned seq_rq_merge_deadline_usecs;
217 int last_rq_rw;
218 sector_t last_rq_pos;
219 ktime_t last_rq_start_time;
220
221 /* for blk-mq request-based DM support */
222 struct blk_mq_tag_set *tag_set;
223 bool use_blk_mq:1;
224 bool init_tio_pdu:1;
225};
226
227#ifdef CONFIG_DM_MQ_DEFAULT
228static bool use_blk_mq = true;
229#else
230static bool use_blk_mq = false;
231#endif
232
233#define DM_MQ_NR_HW_QUEUES 1
234#define DM_MQ_QUEUE_DEPTH 2048
235#define DM_NUMA_NODE NUMA_NO_NODE
236
237static unsigned dm_mq_nr_hw_queues = DM_MQ_NR_HW_QUEUES;
238static unsigned dm_mq_queue_depth = DM_MQ_QUEUE_DEPTH;
239static int dm_numa_node = DM_NUMA_NODE;
240
241bool dm_use_blk_mq(struct mapped_device *md)
242{
243 return md->use_blk_mq;
244}
245EXPORT_SYMBOL_GPL(dm_use_blk_mq);
246
247/*
248 * For mempools pre-allocation at the table loading time.
249 */
250struct dm_md_mempools {
251 mempool_t *io_pool;
252 mempool_t *rq_pool;
253 struct bio_set *bs;
254};
255
256struct table_device {
257 struct list_head list;
258 atomic_t count;
259 struct dm_dev dm_dev;
260};
261
262#define RESERVED_BIO_BASED_IOS 16
263#define RESERVED_REQUEST_BASED_IOS 256
264#define RESERVED_MAX_IOS 1024
265static struct kmem_cache *_io_cache;
266static struct kmem_cache *_rq_tio_cache;
267static struct kmem_cache *_rq_cache;
268
269/*
270 * Bio-based DM's mempools' reserved IOs set by the user.
271 */
272static unsigned reserved_bio_based_ios = RESERVED_BIO_BASED_IOS;
273
274/*
275 * Request-based DM's mempools' reserved IOs set by the user.
276 */
277static unsigned reserved_rq_based_ios = RESERVED_REQUEST_BASED_IOS;
278
279static int __dm_get_module_param_int(int *module_param, int min, int max)
280{
281 int param = ACCESS_ONCE(*module_param);
282 int modified_param = 0;
283 bool modified = true;
284
285 if (param < min)
286 modified_param = min;
287 else if (param > max)
288 modified_param = max;
289 else
290 modified = false;
291
292 if (modified) {
293 (void)cmpxchg(module_param, param, modified_param);
294 param = modified_param;
295 }
296
297 return param;
298}
299
300static unsigned __dm_get_module_param(unsigned *module_param,
301 unsigned def, unsigned max)
302{
303 unsigned param = ACCESS_ONCE(*module_param);
304 unsigned modified_param = 0;
305
306 if (!param)
307 modified_param = def;
308 else if (param > max)
309 modified_param = max;
310
311 if (modified_param) {
312 (void)cmpxchg(module_param, param, modified_param);
313 param = modified_param;
314 }
315
316 return param;
317}
318
319unsigned dm_get_reserved_bio_based_ios(void)
320{
321 return __dm_get_module_param(&reserved_bio_based_ios,
322 RESERVED_BIO_BASED_IOS, RESERVED_MAX_IOS);
323}
324EXPORT_SYMBOL_GPL(dm_get_reserved_bio_based_ios);
325
326unsigned dm_get_reserved_rq_based_ios(void)
327{
328 return __dm_get_module_param(&reserved_rq_based_ios,
329 RESERVED_REQUEST_BASED_IOS, RESERVED_MAX_IOS);
330}
331EXPORT_SYMBOL_GPL(dm_get_reserved_rq_based_ios);
332
333static unsigned dm_get_blk_mq_nr_hw_queues(void)
334{
335 return __dm_get_module_param(&dm_mq_nr_hw_queues, 1, 32);
336}
337
338static unsigned dm_get_blk_mq_queue_depth(void)
339{
340 return __dm_get_module_param(&dm_mq_queue_depth,
341 DM_MQ_QUEUE_DEPTH, BLK_MQ_MAX_DEPTH);
342}
343
344static unsigned dm_get_numa_node(void)
345{
346 return __dm_get_module_param_int(&dm_numa_node,
347 DM_NUMA_NODE, num_online_nodes() - 1);
348}
349
350static int __init local_init(void)
351{
352 int r = -ENOMEM;
353
354 /* allocate a slab for the dm_ios */
355 _io_cache = KMEM_CACHE(dm_io, 0);
356 if (!_io_cache)
357 return r;
358
359 _rq_tio_cache = KMEM_CACHE(dm_rq_target_io, 0);
360 if (!_rq_tio_cache)
361 goto out_free_io_cache;
362
363 _rq_cache = kmem_cache_create("dm_old_clone_request", sizeof(struct request),
364 __alignof__(struct request), 0, NULL);
365 if (!_rq_cache)
366 goto out_free_rq_tio_cache;
367
368 r = dm_uevent_init();
369 if (r)
370 goto out_free_rq_cache;
371
372 deferred_remove_workqueue = alloc_workqueue("kdmremove", WQ_UNBOUND, 1);
373 if (!deferred_remove_workqueue) {
374 r = -ENOMEM;
375 goto out_uevent_exit;
376 }
377
378 _major = major;
379 r = register_blkdev(_major, _name);
380 if (r < 0)
381 goto out_free_workqueue;
382
383 if (!_major)
384 _major = r;
385
386 return 0;
387
388out_free_workqueue:
389 destroy_workqueue(deferred_remove_workqueue);
390out_uevent_exit:
391 dm_uevent_exit();
392out_free_rq_cache:
393 kmem_cache_destroy(_rq_cache);
394out_free_rq_tio_cache:
395 kmem_cache_destroy(_rq_tio_cache);
396out_free_io_cache:
397 kmem_cache_destroy(_io_cache);
398
399 return r;
400}
401
402static void local_exit(void)
403{
404 flush_scheduled_work();
405 destroy_workqueue(deferred_remove_workqueue);
406
407 kmem_cache_destroy(_rq_cache);
408 kmem_cache_destroy(_rq_tio_cache);
409 kmem_cache_destroy(_io_cache);
410 unregister_blkdev(_major, _name);
411 dm_uevent_exit();
412
413 _major = 0;
414
415 DMINFO("cleaned up");
416}
417
418static int (*_inits[])(void) __initdata = {
419 local_init,
420 dm_target_init,
421 dm_linear_init,
422 dm_stripe_init,
423 dm_io_init,
424 dm_kcopyd_init,
425 dm_interface_init,
426 dm_statistics_init,
427};
428
429static void (*_exits[])(void) = {
430 local_exit,
431 dm_target_exit,
432 dm_linear_exit,
433 dm_stripe_exit,
434 dm_io_exit,
435 dm_kcopyd_exit,
436 dm_interface_exit,
437 dm_statistics_exit,
438};
439
440static int __init dm_init(void)
441{
442 const int count = ARRAY_SIZE(_inits);
443
444 int r, i;
445
446 for (i = 0; i < count; i++) {
447 r = _inits[i]();
448 if (r)
449 goto bad;
450 }
451
452 return 0;
453
454 bad:
455 while (i--)
456 _exits[i]();
457
458 return r;
459}
460
461static void __exit dm_exit(void)
462{
463 int i = ARRAY_SIZE(_exits);
464
465 while (i--)
466 _exits[i]();
467
468 /*
469 * Should be empty by this point.
470 */
471 idr_destroy(&_minor_idr);
472}
473
474/*
475 * Block device functions
476 */
477int dm_deleting_md(struct mapped_device *md)
478{
479 return test_bit(DMF_DELETING, &md->flags);
480}
481
482static int dm_blk_open(struct block_device *bdev, fmode_t mode)
483{
484 struct mapped_device *md;
485
486 spin_lock(&_minor_lock);
487
488 md = bdev->bd_disk->private_data;
489 if (!md)
490 goto out;
491
492 if (test_bit(DMF_FREEING, &md->flags) ||
493 dm_deleting_md(md)) {
494 md = NULL;
495 goto out;
496 }
497
498 dm_get(md);
499 atomic_inc(&md->open_count);
500out:
501 spin_unlock(&_minor_lock);
502
503 return md ? 0 : -ENXIO;
504}
505
506static void dm_blk_close(struct gendisk *disk, fmode_t mode)
507{
508 struct mapped_device *md;
509
510 spin_lock(&_minor_lock);
511
512 md = disk->private_data;
513 if (WARN_ON(!md))
514 goto out;
515
516 if (atomic_dec_and_test(&md->open_count) &&
517 (test_bit(DMF_DEFERRED_REMOVE, &md->flags)))
518 queue_work(deferred_remove_workqueue, &deferred_remove_work);
519
520 dm_put(md);
521out:
522 spin_unlock(&_minor_lock);
523}
524
525int dm_open_count(struct mapped_device *md)
526{
527 return atomic_read(&md->open_count);
528}
529
530/*
531 * Guarantees nothing is using the device before it's deleted.
532 */
533int dm_lock_for_deletion(struct mapped_device *md, bool mark_deferred, bool only_deferred)
534{
535 int r = 0;
536
537 spin_lock(&_minor_lock);
538
539 if (dm_open_count(md)) {
540 r = -EBUSY;
541 if (mark_deferred)
542 set_bit(DMF_DEFERRED_REMOVE, &md->flags);
543 } else if (only_deferred && !test_bit(DMF_DEFERRED_REMOVE, &md->flags))
544 r = -EEXIST;
545 else
546 set_bit(DMF_DELETING, &md->flags);
547
548 spin_unlock(&_minor_lock);
549
550 return r;
551}
552
553int dm_cancel_deferred_remove(struct mapped_device *md)
554{
555 int r = 0;
556
557 spin_lock(&_minor_lock);
558
559 if (test_bit(DMF_DELETING, &md->flags))
560 r = -EBUSY;
561 else
562 clear_bit(DMF_DEFERRED_REMOVE, &md->flags);
563
564 spin_unlock(&_minor_lock);
565
566 return r;
567}
568
569static void do_deferred_remove(struct work_struct *w)
570{
571 dm_deferred_remove();
572}
573
574sector_t dm_get_size(struct mapped_device *md)
575{
576 return get_capacity(md->disk);
577}
578
579struct request_queue *dm_get_md_queue(struct mapped_device *md)
580{
581 return md->queue;
582}
583
584struct dm_stats *dm_get_stats(struct mapped_device *md)
585{
586 return &md->stats;
587}
588
589static int dm_blk_getgeo(struct block_device *bdev, struct hd_geometry *geo)
590{
591 struct mapped_device *md = bdev->bd_disk->private_data;
592
593 return dm_get_geometry(md, geo);
594}
595
596static int dm_grab_bdev_for_ioctl(struct mapped_device *md,
597 struct block_device **bdev,
598 fmode_t *mode)
599{
600 struct dm_target *tgt;
601 struct dm_table *map;
602 int srcu_idx, r;
603
604retry:
605 r = -ENOTTY;
606 map = dm_get_live_table(md, &srcu_idx);
607 if (!map || !dm_table_get_size(map))
608 goto out;
609
610 /* We only support devices that have a single target */
611 if (dm_table_get_num_targets(map) != 1)
612 goto out;
613
614 tgt = dm_table_get_target(map, 0);
615 if (!tgt->type->prepare_ioctl)
616 goto out;
617
618 if (dm_suspended_md(md)) {
619 r = -EAGAIN;
620 goto out;
621 }
622
623 r = tgt->type->prepare_ioctl(tgt, bdev, mode);
624 if (r < 0)
625 goto out;
626
627 bdgrab(*bdev);
628 dm_put_live_table(md, srcu_idx);
629 return r;
630
631out:
632 dm_put_live_table(md, srcu_idx);
633 if (r == -ENOTCONN && !fatal_signal_pending(current)) {
634 msleep(10);
635 goto retry;
636 }
637 return r;
638}
639
640static int dm_blk_ioctl(struct block_device *bdev, fmode_t mode,
641 unsigned int cmd, unsigned long arg)
642{
643 struct mapped_device *md = bdev->bd_disk->private_data;
644 int r;
645
646 r = dm_grab_bdev_for_ioctl(md, &bdev, &mode);
647 if (r < 0)
648 return r;
649
650 if (r > 0) {
651 /*
652 * Target determined this ioctl is being issued against
653 * a logical partition of the parent bdev; so extra
654 * validation is needed.
655 */
656 r = scsi_verify_blk_ioctl(NULL, cmd);
657 if (r)
658 goto out;
659 }
660
661 r = __blkdev_driver_ioctl(bdev, mode, cmd, arg);
662out:
663 bdput(bdev);
664 return r;
665}
666
667static struct dm_io *alloc_io(struct mapped_device *md)
668{
669 return mempool_alloc(md->io_pool, GFP_NOIO);
670}
671
672static void free_io(struct mapped_device *md, struct dm_io *io)
673{
674 mempool_free(io, md->io_pool);
675}
676
677static void free_tio(struct mapped_device *md, struct dm_target_io *tio)
678{
679 bio_put(&tio->clone);
680}
681
682static struct dm_rq_target_io *alloc_old_rq_tio(struct mapped_device *md,
683 gfp_t gfp_mask)
684{
685 return mempool_alloc(md->io_pool, gfp_mask);
686}
687
688static void free_old_rq_tio(struct dm_rq_target_io *tio)
689{
690 mempool_free(tio, tio->md->io_pool);
691}
692
693static struct request *alloc_old_clone_request(struct mapped_device *md,
694 gfp_t gfp_mask)
695{
696 return mempool_alloc(md->rq_pool, gfp_mask);
697}
698
699static void free_old_clone_request(struct mapped_device *md, struct request *rq)
700{
701 mempool_free(rq, md->rq_pool);
702}
703
704static int md_in_flight(struct mapped_device *md)
705{
706 return atomic_read(&md->pending[READ]) +
707 atomic_read(&md->pending[WRITE]);
708}
709
710static void start_io_acct(struct dm_io *io)
711{
712 struct mapped_device *md = io->md;
713 struct bio *bio = io->bio;
714 int cpu;
715 int rw = bio_data_dir(bio);
716
717 io->start_time = jiffies;
718
719 cpu = part_stat_lock();
720 part_round_stats(cpu, &dm_disk(md)->part0);
721 part_stat_unlock();
722 atomic_set(&dm_disk(md)->part0.in_flight[rw],
723 atomic_inc_return(&md->pending[rw]));
724
725 if (unlikely(dm_stats_used(&md->stats)))
726 dm_stats_account_io(&md->stats, bio->bi_rw, bio->bi_iter.bi_sector,
727 bio_sectors(bio), false, 0, &io->stats_aux);
728}
729
730static void end_io_acct(struct dm_io *io)
731{
732 struct mapped_device *md = io->md;
733 struct bio *bio = io->bio;
734 unsigned long duration = jiffies - io->start_time;
735 int pending;
736 int rw = bio_data_dir(bio);
737
738 generic_end_io_acct(rw, &dm_disk(md)->part0, io->start_time);
739
740 if (unlikely(dm_stats_used(&md->stats)))
741 dm_stats_account_io(&md->stats, bio->bi_rw, bio->bi_iter.bi_sector,
742 bio_sectors(bio), true, duration, &io->stats_aux);
743
744 /*
745 * After this is decremented the bio must not be touched if it is
746 * a flush.
747 */
748 pending = atomic_dec_return(&md->pending[rw]);
749 atomic_set(&dm_disk(md)->part0.in_flight[rw], pending);
750 pending += atomic_read(&md->pending[rw^0x1]);
751
752 /* nudge anyone waiting on suspend queue */
753 if (!pending)
754 wake_up(&md->wait);
755}
756
757/*
758 * Add the bio to the list of deferred io.
759 */
760static void queue_io(struct mapped_device *md, struct bio *bio)
761{
762 unsigned long flags;
763
764 spin_lock_irqsave(&md->deferred_lock, flags);
765 bio_list_add(&md->deferred, bio);
766 spin_unlock_irqrestore(&md->deferred_lock, flags);
767 queue_work(md->wq, &md->work);
768}
769
770/*
771 * Everyone (including functions in this file), should use this
772 * function to access the md->map field, and make sure they call
773 * dm_put_live_table() when finished.
774 */
775struct dm_table *dm_get_live_table(struct mapped_device *md, int *srcu_idx) __acquires(md->io_barrier)
776{
777 *srcu_idx = srcu_read_lock(&md->io_barrier);
778
779 return srcu_dereference(md->map, &md->io_barrier);
780}
781
782void dm_put_live_table(struct mapped_device *md, int srcu_idx) __releases(md->io_barrier)
783{
784 srcu_read_unlock(&md->io_barrier, srcu_idx);
785}
786
787void dm_sync_table(struct mapped_device *md)
788{
789 synchronize_srcu(&md->io_barrier);
790 synchronize_rcu_expedited();
791}
792
793/*
794 * A fast alternative to dm_get_live_table/dm_put_live_table.
795 * The caller must not block between these two functions.
796 */
797static struct dm_table *dm_get_live_table_fast(struct mapped_device *md) __acquires(RCU)
798{
799 rcu_read_lock();
800 return rcu_dereference(md->map);
801}
802
803static void dm_put_live_table_fast(struct mapped_device *md) __releases(RCU)
804{
805 rcu_read_unlock();
806}
807
808/*
809 * Open a table device so we can use it as a map destination.
810 */
811static int open_table_device(struct table_device *td, dev_t dev,
812 struct mapped_device *md)
813{
814 static char *_claim_ptr = "I belong to device-mapper";
815 struct block_device *bdev;
816
817 int r;
818
819 BUG_ON(td->dm_dev.bdev);
820
821 bdev = blkdev_get_by_dev(dev, td->dm_dev.mode | FMODE_EXCL, _claim_ptr);
822 if (IS_ERR(bdev))
823 return PTR_ERR(bdev);
824
825 r = bd_link_disk_holder(bdev, dm_disk(md));
826 if (r) {
827 blkdev_put(bdev, td->dm_dev.mode | FMODE_EXCL);
828 return r;
829 }
830
831 td->dm_dev.bdev = bdev;
832 return 0;
833}
834
835/*
836 * Close a table device that we've been using.
837 */
838static void close_table_device(struct table_device *td, struct mapped_device *md)
839{
840 if (!td->dm_dev.bdev)
841 return;
842
843 bd_unlink_disk_holder(td->dm_dev.bdev, dm_disk(md));
844 blkdev_put(td->dm_dev.bdev, td->dm_dev.mode | FMODE_EXCL);
845 td->dm_dev.bdev = NULL;
846}
847
848static struct table_device *find_table_device(struct list_head *l, dev_t dev,
849 fmode_t mode) {
850 struct table_device *td;
851
852 list_for_each_entry(td, l, list)
853 if (td->dm_dev.bdev->bd_dev == dev && td->dm_dev.mode == mode)
854 return td;
855
856 return NULL;
857}
858
859int dm_get_table_device(struct mapped_device *md, dev_t dev, fmode_t mode,
860 struct dm_dev **result) {
861 int r;
862 struct table_device *td;
863
864 mutex_lock(&md->table_devices_lock);
865 td = find_table_device(&md->table_devices, dev, mode);
866 if (!td) {
867 td = kmalloc_node(sizeof(*td), GFP_KERNEL, md->numa_node_id);
868 if (!td) {
869 mutex_unlock(&md->table_devices_lock);
870 return -ENOMEM;
871 }
872
873 td->dm_dev.mode = mode;
874 td->dm_dev.bdev = NULL;
875
876 if ((r = open_table_device(td, dev, md))) {
877 mutex_unlock(&md->table_devices_lock);
878 kfree(td);
879 return r;
880 }
881
882 format_dev_t(td->dm_dev.name, dev);
883
884 atomic_set(&td->count, 0);
885 list_add(&td->list, &md->table_devices);
886 }
887 atomic_inc(&td->count);
888 mutex_unlock(&md->table_devices_lock);
889
890 *result = &td->dm_dev;
891 return 0;
892}
893EXPORT_SYMBOL_GPL(dm_get_table_device);
894
895void dm_put_table_device(struct mapped_device *md, struct dm_dev *d)
896{
897 struct table_device *td = container_of(d, struct table_device, dm_dev);
898
899 mutex_lock(&md->table_devices_lock);
900 if (atomic_dec_and_test(&td->count)) {
901 close_table_device(td, md);
902 list_del(&td->list);
903 kfree(td);
904 }
905 mutex_unlock(&md->table_devices_lock);
906}
907EXPORT_SYMBOL(dm_put_table_device);
908
909static void free_table_devices(struct list_head *devices)
910{
911 struct list_head *tmp, *next;
912
913 list_for_each_safe(tmp, next, devices) {
914 struct table_device *td = list_entry(tmp, struct table_device, list);
915
916 DMWARN("dm_destroy: %s still exists with %d references",
917 td->dm_dev.name, atomic_read(&td->count));
918 kfree(td);
919 }
920}
921
922/*
923 * Get the geometry associated with a dm device
924 */
925int dm_get_geometry(struct mapped_device *md, struct hd_geometry *geo)
926{
927 *geo = md->geometry;
928
929 return 0;
930}
931
932/*
933 * Set the geometry of a device.
934 */
935int dm_set_geometry(struct mapped_device *md, struct hd_geometry *geo)
936{
937 sector_t sz = (sector_t)geo->cylinders * geo->heads * geo->sectors;
938
939 if (geo->start > sz) {
940 DMWARN("Start sector is beyond the geometry limits.");
941 return -EINVAL;
942 }
943
944 md->geometry = *geo;
945
946 return 0;
947}
948
949/*-----------------------------------------------------------------
950 * CRUD START:
951 * A more elegant soln is in the works that uses the queue
952 * merge fn, unfortunately there are a couple of changes to
953 * the block layer that I want to make for this. So in the
954 * interests of getting something for people to use I give
955 * you this clearly demarcated crap.
956 *---------------------------------------------------------------*/
957
958static int __noflush_suspending(struct mapped_device *md)
959{
960 return test_bit(DMF_NOFLUSH_SUSPENDING, &md->flags);
961}
962
963/*
964 * Decrements the number of outstanding ios that a bio has been
965 * cloned into, completing the original io if necc.
966 */
967static void dec_pending(struct dm_io *io, int error)
968{
969 unsigned long flags;
970 int io_error;
971 struct bio *bio;
972 struct mapped_device *md = io->md;
973
974 /* Push-back supersedes any I/O errors */
975 if (unlikely(error)) {
976 spin_lock_irqsave(&io->endio_lock, flags);
977 if (!(io->error > 0 && __noflush_suspending(md)))
978 io->error = error;
979 spin_unlock_irqrestore(&io->endio_lock, flags);
980 }
981
982 if (atomic_dec_and_test(&io->io_count)) {
983 if (io->error == DM_ENDIO_REQUEUE) {
984 /*
985 * Target requested pushing back the I/O.
986 */
987 spin_lock_irqsave(&md->deferred_lock, flags);
988 if (__noflush_suspending(md))
989 bio_list_add_head(&md->deferred, io->bio);
990 else
991 /* noflush suspend was interrupted. */
992 io->error = -EIO;
993 spin_unlock_irqrestore(&md->deferred_lock, flags);
994 }
995
996 io_error = io->error;
997 bio = io->bio;
998 end_io_acct(io);
999 free_io(md, io);
1000
1001 if (io_error == DM_ENDIO_REQUEUE)
1002 return;
1003
1004 if ((bio->bi_rw & REQ_FLUSH) && bio->bi_iter.bi_size) {
1005 /*
1006 * Preflush done for flush with data, reissue
1007 * without REQ_FLUSH.
1008 */
1009 bio->bi_rw &= ~REQ_FLUSH;
1010 queue_io(md, bio);
1011 } else {
1012 /* done with normal IO or empty flush */
1013 trace_block_bio_complete(md->queue, bio, io_error);
1014 bio->bi_error = io_error;
1015 bio_endio(bio);
1016 }
1017 }
1018}
1019
1020static void disable_write_same(struct mapped_device *md)
1021{
1022 struct queue_limits *limits = dm_get_queue_limits(md);
1023
1024 /* device doesn't really support WRITE SAME, disable it */
1025 limits->max_write_same_sectors = 0;
1026}
1027
1028static void clone_endio(struct bio *bio)
1029{
1030 int error = bio->bi_error;
1031 int r = error;
1032 struct dm_target_io *tio = container_of(bio, struct dm_target_io, clone);
1033 struct dm_io *io = tio->io;
1034 struct mapped_device *md = tio->io->md;
1035 dm_endio_fn endio = tio->ti->type->end_io;
1036
1037 if (endio) {
1038 r = endio(tio->ti, bio, error);
1039 if (r < 0 || r == DM_ENDIO_REQUEUE)
1040 /*
1041 * error and requeue request are handled
1042 * in dec_pending().
1043 */
1044 error = r;
1045 else if (r == DM_ENDIO_INCOMPLETE)
1046 /* The target will handle the io */
1047 return;
1048 else if (r) {
1049 DMWARN("unimplemented target endio return value: %d", r);
1050 BUG();
1051 }
1052 }
1053
1054 if (unlikely(r == -EREMOTEIO && (bio->bi_rw & REQ_WRITE_SAME) &&
1055 !bdev_get_queue(bio->bi_bdev)->limits.max_write_same_sectors))
1056 disable_write_same(md);
1057
1058 free_tio(md, tio);
1059 dec_pending(io, error);
1060}
1061
1062/*
1063 * Partial completion handling for request-based dm
1064 */
1065static void end_clone_bio(struct bio *clone)
1066{
1067 struct dm_rq_clone_bio_info *info =
1068 container_of(clone, struct dm_rq_clone_bio_info, clone);
1069 struct dm_rq_target_io *tio = info->tio;
1070 struct bio *bio = info->orig;
1071 unsigned int nr_bytes = info->orig->bi_iter.bi_size;
1072 int error = clone->bi_error;
1073
1074 bio_put(clone);
1075
1076 if (tio->error)
1077 /*
1078 * An error has already been detected on the request.
1079 * Once error occurred, just let clone->end_io() handle
1080 * the remainder.
1081 */
1082 return;
1083 else if (error) {
1084 /*
1085 * Don't notice the error to the upper layer yet.
1086 * The error handling decision is made by the target driver,
1087 * when the request is completed.
1088 */
1089 tio->error = error;
1090 return;
1091 }
1092
1093 /*
1094 * I/O for the bio successfully completed.
1095 * Notice the data completion to the upper layer.
1096 */
1097
1098 /*
1099 * bios are processed from the head of the list.
1100 * So the completing bio should always be rq->bio.
1101 * If it's not, something wrong is happening.
1102 */
1103 if (tio->orig->bio != bio)
1104 DMERR("bio completion is going in the middle of the request");
1105
1106 /*
1107 * Update the original request.
1108 * Do not use blk_end_request() here, because it may complete
1109 * the original request before the clone, and break the ordering.
1110 */
1111 blk_update_request(tio->orig, 0, nr_bytes);
1112}
1113
1114static struct dm_rq_target_io *tio_from_request(struct request *rq)
1115{
1116 return (rq->q->mq_ops ? blk_mq_rq_to_pdu(rq) : rq->special);
1117}
1118
1119static void rq_end_stats(struct mapped_device *md, struct request *orig)
1120{
1121 if (unlikely(dm_stats_used(&md->stats))) {
1122 struct dm_rq_target_io *tio = tio_from_request(orig);
1123 tio->duration_jiffies = jiffies - tio->duration_jiffies;
1124 dm_stats_account_io(&md->stats, orig->cmd_flags, blk_rq_pos(orig),
1125 tio->n_sectors, true, tio->duration_jiffies,
1126 &tio->stats_aux);
1127 }
1128}
1129
1130/*
1131 * Don't touch any member of the md after calling this function because
1132 * the md may be freed in dm_put() at the end of this function.
1133 * Or do dm_get() before calling this function and dm_put() later.
1134 */
1135static void rq_completed(struct mapped_device *md, int rw, bool run_queue)
1136{
1137 atomic_dec(&md->pending[rw]);
1138
1139 /* nudge anyone waiting on suspend queue */
1140 if (!md_in_flight(md))
1141 wake_up(&md->wait);
1142
1143 /*
1144 * Run this off this callpath, as drivers could invoke end_io while
1145 * inside their request_fn (and holding the queue lock). Calling
1146 * back into ->request_fn() could deadlock attempting to grab the
1147 * queue lock again.
1148 */
1149 if (!md->queue->mq_ops && run_queue)
1150 blk_run_queue_async(md->queue);
1151
1152 /*
1153 * dm_put() must be at the end of this function. See the comment above
1154 */
1155 dm_put(md);
1156}
1157
1158static void free_rq_clone(struct request *clone)
1159{
1160 struct dm_rq_target_io *tio = clone->end_io_data;
1161 struct mapped_device *md = tio->md;
1162
1163 blk_rq_unprep_clone(clone);
1164
1165 if (md->type == DM_TYPE_MQ_REQUEST_BASED)
1166 /* stacked on blk-mq queue(s) */
1167 tio->ti->type->release_clone_rq(clone);
1168 else if (!md->queue->mq_ops)
1169 /* request_fn queue stacked on request_fn queue(s) */
1170 free_old_clone_request(md, clone);
1171
1172 if (!md->queue->mq_ops)
1173 free_old_rq_tio(tio);
1174}
1175
1176/*
1177 * Complete the clone and the original request.
1178 * Must be called without clone's queue lock held,
1179 * see end_clone_request() for more details.
1180 */
1181static void dm_end_request(struct request *clone, int error)
1182{
1183 int rw = rq_data_dir(clone);
1184 struct dm_rq_target_io *tio = clone->end_io_data;
1185 struct mapped_device *md = tio->md;
1186 struct request *rq = tio->orig;
1187
1188 if (rq->cmd_type == REQ_TYPE_BLOCK_PC) {
1189 rq->errors = clone->errors;
1190 rq->resid_len = clone->resid_len;
1191
1192 if (rq->sense)
1193 /*
1194 * We are using the sense buffer of the original
1195 * request.
1196 * So setting the length of the sense data is enough.
1197 */
1198 rq->sense_len = clone->sense_len;
1199 }
1200
1201 free_rq_clone(clone);
1202 rq_end_stats(md, rq);
1203 if (!rq->q->mq_ops)
1204 blk_end_request_all(rq, error);
1205 else
1206 blk_mq_end_request(rq, error);
1207 rq_completed(md, rw, true);
1208}
1209
1210static void dm_unprep_request(struct request *rq)
1211{
1212 struct dm_rq_target_io *tio = tio_from_request(rq);
1213 struct request *clone = tio->clone;
1214
1215 if (!rq->q->mq_ops) {
1216 rq->special = NULL;
1217 rq->cmd_flags &= ~REQ_DONTPREP;
1218 }
1219
1220 if (clone)
1221 free_rq_clone(clone);
1222 else if (!tio->md->queue->mq_ops)
1223 free_old_rq_tio(tio);
1224}
1225
1226/*
1227 * Requeue the original request of a clone.
1228 */
1229static void dm_old_requeue_request(struct request *rq)
1230{
1231 struct request_queue *q = rq->q;
1232 unsigned long flags;
1233
1234 spin_lock_irqsave(q->queue_lock, flags);
1235 blk_requeue_request(q, rq);
1236 blk_run_queue_async(q);
1237 spin_unlock_irqrestore(q->queue_lock, flags);
1238}
1239
1240static void dm_mq_requeue_request(struct request *rq)
1241{
1242 struct request_queue *q = rq->q;
1243 unsigned long flags;
1244
1245 blk_mq_requeue_request(rq);
1246 spin_lock_irqsave(q->queue_lock, flags);
1247 if (!blk_queue_stopped(q))
1248 blk_mq_kick_requeue_list(q);
1249 spin_unlock_irqrestore(q->queue_lock, flags);
1250}
1251
1252static void dm_requeue_original_request(struct mapped_device *md,
1253 struct request *rq)
1254{
1255 int rw = rq_data_dir(rq);
1256
1257 rq_end_stats(md, rq);
1258 dm_unprep_request(rq);
1259
1260 if (!rq->q->mq_ops)
1261 dm_old_requeue_request(rq);
1262 else
1263 dm_mq_requeue_request(rq);
1264
1265 rq_completed(md, rw, false);
1266}
1267
1268static void dm_old_stop_queue(struct request_queue *q)
1269{
1270 unsigned long flags;
1271
1272 spin_lock_irqsave(q->queue_lock, flags);
1273 if (blk_queue_stopped(q)) {
1274 spin_unlock_irqrestore(q->queue_lock, flags);
1275 return;
1276 }
1277
1278 blk_stop_queue(q);
1279 spin_unlock_irqrestore(q->queue_lock, flags);
1280}
1281
1282static void dm_stop_queue(struct request_queue *q)
1283{
1284 if (!q->mq_ops)
1285 dm_old_stop_queue(q);
1286 else
1287 blk_mq_stop_hw_queues(q);
1288}
1289
1290static void dm_old_start_queue(struct request_queue *q)
1291{
1292 unsigned long flags;
1293
1294 spin_lock_irqsave(q->queue_lock, flags);
1295 if (blk_queue_stopped(q))
1296 blk_start_queue(q);
1297 spin_unlock_irqrestore(q->queue_lock, flags);
1298}
1299
1300static void dm_start_queue(struct request_queue *q)
1301{
1302 if (!q->mq_ops)
1303 dm_old_start_queue(q);
1304 else {
1305 blk_mq_start_stopped_hw_queues(q, true);
1306 blk_mq_kick_requeue_list(q);
1307 }
1308}
1309
1310static void dm_done(struct request *clone, int error, bool mapped)
1311{
1312 int r = error;
1313 struct dm_rq_target_io *tio = clone->end_io_data;
1314 dm_request_endio_fn rq_end_io = NULL;
1315
1316 if (tio->ti) {
1317 rq_end_io = tio->ti->type->rq_end_io;
1318
1319 if (mapped && rq_end_io)
1320 r = rq_end_io(tio->ti, clone, error, &tio->info);
1321 }
1322
1323 if (unlikely(r == -EREMOTEIO && (clone->cmd_flags & REQ_WRITE_SAME) &&
1324 !clone->q->limits.max_write_same_sectors))
1325 disable_write_same(tio->md);
1326
1327 if (r <= 0)
1328 /* The target wants to complete the I/O */
1329 dm_end_request(clone, r);
1330 else if (r == DM_ENDIO_INCOMPLETE)
1331 /* The target will handle the I/O */
1332 return;
1333 else if (r == DM_ENDIO_REQUEUE)
1334 /* The target wants to requeue the I/O */
1335 dm_requeue_original_request(tio->md, tio->orig);
1336 else {
1337 DMWARN("unimplemented target endio return value: %d", r);
1338 BUG();
1339 }
1340}
1341
1342/*
1343 * Request completion handler for request-based dm
1344 */
1345static void dm_softirq_done(struct request *rq)
1346{
1347 bool mapped = true;
1348 struct dm_rq_target_io *tio = tio_from_request(rq);
1349 struct request *clone = tio->clone;
1350 int rw;
1351
1352 if (!clone) {
1353 rq_end_stats(tio->md, rq);
1354 rw = rq_data_dir(rq);
1355 if (!rq->q->mq_ops) {
1356 blk_end_request_all(rq, tio->error);
1357 rq_completed(tio->md, rw, false);
1358 free_old_rq_tio(tio);
1359 } else {
1360 blk_mq_end_request(rq, tio->error);
1361 rq_completed(tio->md, rw, false);
1362 }
1363 return;
1364 }
1365
1366 if (rq->cmd_flags & REQ_FAILED)
1367 mapped = false;
1368
1369 dm_done(clone, tio->error, mapped);
1370}
1371
1372/*
1373 * Complete the clone and the original request with the error status
1374 * through softirq context.
1375 */
1376static void dm_complete_request(struct request *rq, int error)
1377{
1378 struct dm_rq_target_io *tio = tio_from_request(rq);
1379
1380 tio->error = error;
1381 if (!rq->q->mq_ops)
1382 blk_complete_request(rq);
1383 else
1384 blk_mq_complete_request(rq, error);
1385}
1386
1387/*
1388 * Complete the not-mapped clone and the original request with the error status
1389 * through softirq context.
1390 * Target's rq_end_io() function isn't called.
1391 * This may be used when the target's map_rq() or clone_and_map_rq() functions fail.
1392 */
1393static void dm_kill_unmapped_request(struct request *rq, int error)
1394{
1395 rq->cmd_flags |= REQ_FAILED;
1396 dm_complete_request(rq, error);
1397}
1398
1399/*
1400 * Called with the clone's queue lock held (in the case of .request_fn)
1401 */
1402static void end_clone_request(struct request *clone, int error)
1403{
1404 struct dm_rq_target_io *tio = clone->end_io_data;
1405
1406 if (!clone->q->mq_ops) {
1407 /*
1408 * For just cleaning up the information of the queue in which
1409 * the clone was dispatched.
1410 * The clone is *NOT* freed actually here because it is alloced
1411 * from dm own mempool (REQ_ALLOCED isn't set).
1412 */
1413 __blk_put_request(clone->q, clone);
1414 }
1415
1416 /*
1417 * Actual request completion is done in a softirq context which doesn't
1418 * hold the clone's queue lock. Otherwise, deadlock could occur because:
1419 * - another request may be submitted by the upper level driver
1420 * of the stacking during the completion
1421 * - the submission which requires queue lock may be done
1422 * against this clone's queue
1423 */
1424 dm_complete_request(tio->orig, error);
1425}
1426
1427/*
1428 * Return maximum size of I/O possible at the supplied sector up to the current
1429 * target boundary.
1430 */
1431static sector_t max_io_len_target_boundary(sector_t sector, struct dm_target *ti)
1432{
1433 sector_t target_offset = dm_target_offset(ti, sector);
1434
1435 return ti->len - target_offset;
1436}
1437
1438static sector_t max_io_len(sector_t sector, struct dm_target *ti)
1439{
1440 sector_t len = max_io_len_target_boundary(sector, ti);
1441 sector_t offset, max_len;
1442
1443 /*
1444 * Does the target need to split even further?
1445 */
1446 if (ti->max_io_len) {
1447 offset = dm_target_offset(ti, sector);
1448 if (unlikely(ti->max_io_len & (ti->max_io_len - 1)))
1449 max_len = sector_div(offset, ti->max_io_len);
1450 else
1451 max_len = offset & (ti->max_io_len - 1);
1452 max_len = ti->max_io_len - max_len;
1453
1454 if (len > max_len)
1455 len = max_len;
1456 }
1457
1458 return len;
1459}
1460
1461int dm_set_target_max_io_len(struct dm_target *ti, sector_t len)
1462{
1463 if (len > UINT_MAX) {
1464 DMERR("Specified maximum size of target IO (%llu) exceeds limit (%u)",
1465 (unsigned long long)len, UINT_MAX);
1466 ti->error = "Maximum size of target IO is too large";
1467 return -EINVAL;
1468 }
1469
1470 ti->max_io_len = (uint32_t) len;
1471
1472 return 0;
1473}
1474EXPORT_SYMBOL_GPL(dm_set_target_max_io_len);
1475
1476/*
1477 * A target may call dm_accept_partial_bio only from the map routine. It is
1478 * allowed for all bio types except REQ_FLUSH.
1479 *
1480 * dm_accept_partial_bio informs the dm that the target only wants to process
1481 * additional n_sectors sectors of the bio and the rest of the data should be
1482 * sent in a next bio.
1483 *
1484 * A diagram that explains the arithmetics:
1485 * +--------------------+---------------+-------+
1486 * | 1 | 2 | 3 |
1487 * +--------------------+---------------+-------+
1488 *
1489 * <-------------- *tio->len_ptr --------------->
1490 * <------- bi_size ------->
1491 * <-- n_sectors -->
1492 *
1493 * Region 1 was already iterated over with bio_advance or similar function.
1494 * (it may be empty if the target doesn't use bio_advance)
1495 * Region 2 is the remaining bio size that the target wants to process.
1496 * (it may be empty if region 1 is non-empty, although there is no reason
1497 * to make it empty)
1498 * The target requires that region 3 is to be sent in the next bio.
1499 *
1500 * If the target wants to receive multiple copies of the bio (via num_*bios, etc),
1501 * the partially processed part (the sum of regions 1+2) must be the same for all
1502 * copies of the bio.
1503 */
1504void dm_accept_partial_bio(struct bio *bio, unsigned n_sectors)
1505{
1506 struct dm_target_io *tio = container_of(bio, struct dm_target_io, clone);
1507 unsigned bi_size = bio->bi_iter.bi_size >> SECTOR_SHIFT;
1508 BUG_ON(bio->bi_rw & REQ_FLUSH);
1509 BUG_ON(bi_size > *tio->len_ptr);
1510 BUG_ON(n_sectors > bi_size);
1511 *tio->len_ptr -= bi_size - n_sectors;
1512 bio->bi_iter.bi_size = n_sectors << SECTOR_SHIFT;
1513}
1514EXPORT_SYMBOL_GPL(dm_accept_partial_bio);
1515
1516static void __map_bio(struct dm_target_io *tio)
1517{
1518 int r;
1519 sector_t sector;
1520 struct mapped_device *md;
1521 struct bio *clone = &tio->clone;
1522 struct dm_target *ti = tio->ti;
1523
1524 clone->bi_end_io = clone_endio;
1525
1526 /*
1527 * Map the clone. If r == 0 we don't need to do
1528 * anything, the target has assumed ownership of
1529 * this io.
1530 */
1531 atomic_inc(&tio->io->io_count);
1532 sector = clone->bi_iter.bi_sector;
1533 r = ti->type->map(ti, clone);
1534 if (r == DM_MAPIO_REMAPPED) {
1535 /* the bio has been remapped so dispatch it */
1536
1537 trace_block_bio_remap(bdev_get_queue(clone->bi_bdev), clone,
1538 tio->io->bio->bi_bdev->bd_dev, sector);
1539
1540 generic_make_request(clone);
1541 } else if (r < 0 || r == DM_MAPIO_REQUEUE) {
1542 /* error the io and bail out, or requeue it if needed */
1543 md = tio->io->md;
1544 dec_pending(tio->io, r);
1545 free_tio(md, tio);
1546 } else if (r != DM_MAPIO_SUBMITTED) {
1547 DMWARN("unimplemented target map return value: %d", r);
1548 BUG();
1549 }
1550}
1551
1552struct clone_info {
1553 struct mapped_device *md;
1554 struct dm_table *map;
1555 struct bio *bio;
1556 struct dm_io *io;
1557 sector_t sector;
1558 unsigned sector_count;
1559};
1560
1561static void bio_setup_sector(struct bio *bio, sector_t sector, unsigned len)
1562{
1563 bio->bi_iter.bi_sector = sector;
1564 bio->bi_iter.bi_size = to_bytes(len);
1565}
1566
1567/*
1568 * Creates a bio that consists of range of complete bvecs.
1569 */
1570static int clone_bio(struct dm_target_io *tio, struct bio *bio,
1571 sector_t sector, unsigned len)
1572{
1573 struct bio *clone = &tio->clone;
1574
1575 __bio_clone_fast(clone, bio);
1576
1577 if (bio_integrity(bio)) {
1578 int r = bio_integrity_clone(clone, bio, GFP_NOIO);
1579 if (r < 0)
1580 return r;
1581 }
1582
1583 bio_advance(clone, to_bytes(sector - clone->bi_iter.bi_sector));
1584 clone->bi_iter.bi_size = to_bytes(len);
1585
1586 if (bio_integrity(bio))
1587 bio_integrity_trim(clone, 0, len);
1588
1589 return 0;
1590}
1591
1592static struct dm_target_io *alloc_tio(struct clone_info *ci,
1593 struct dm_target *ti,
1594 unsigned target_bio_nr)
1595{
1596 struct dm_target_io *tio;
1597 struct bio *clone;
1598
1599 clone = bio_alloc_bioset(GFP_NOIO, 0, ci->md->bs);
1600 tio = container_of(clone, struct dm_target_io, clone);
1601
1602 tio->io = ci->io;
1603 tio->ti = ti;
1604 tio->target_bio_nr = target_bio_nr;
1605
1606 return tio;
1607}
1608
1609static void __clone_and_map_simple_bio(struct clone_info *ci,
1610 struct dm_target *ti,
1611 unsigned target_bio_nr, unsigned *len)
1612{
1613 struct dm_target_io *tio = alloc_tio(ci, ti, target_bio_nr);
1614 struct bio *clone = &tio->clone;
1615
1616 tio->len_ptr = len;
1617
1618 __bio_clone_fast(clone, ci->bio);
1619 if (len)
1620 bio_setup_sector(clone, ci->sector, *len);
1621
1622 __map_bio(tio);
1623}
1624
1625static void __send_duplicate_bios(struct clone_info *ci, struct dm_target *ti,
1626 unsigned num_bios, unsigned *len)
1627{
1628 unsigned target_bio_nr;
1629
1630 for (target_bio_nr = 0; target_bio_nr < num_bios; target_bio_nr++)
1631 __clone_and_map_simple_bio(ci, ti, target_bio_nr, len);
1632}
1633
1634static int __send_empty_flush(struct clone_info *ci)
1635{
1636 unsigned target_nr = 0;
1637 struct dm_target *ti;
1638
1639 BUG_ON(bio_has_data(ci->bio));
1640 while ((ti = dm_table_get_target(ci->map, target_nr++)))
1641 __send_duplicate_bios(ci, ti, ti->num_flush_bios, NULL);
1642
1643 return 0;
1644}
1645
1646static int __clone_and_map_data_bio(struct clone_info *ci, struct dm_target *ti,
1647 sector_t sector, unsigned *len)
1648{
1649 struct bio *bio = ci->bio;
1650 struct dm_target_io *tio;
1651 unsigned target_bio_nr;
1652 unsigned num_target_bios = 1;
1653 int r = 0;
1654
1655 /*
1656 * Does the target want to receive duplicate copies of the bio?
1657 */
1658 if (bio_data_dir(bio) == WRITE && ti->num_write_bios)
1659 num_target_bios = ti->num_write_bios(ti, bio);
1660
1661 for (target_bio_nr = 0; target_bio_nr < num_target_bios; target_bio_nr++) {
1662 tio = alloc_tio(ci, ti, target_bio_nr);
1663 tio->len_ptr = len;
1664 r = clone_bio(tio, bio, sector, *len);
1665 if (r < 0) {
1666 free_tio(ci->md, tio);
1667 break;
1668 }
1669 __map_bio(tio);
1670 }
1671
1672 return r;
1673}
1674
1675typedef unsigned (*get_num_bios_fn)(struct dm_target *ti);
1676
1677static unsigned get_num_discard_bios(struct dm_target *ti)
1678{
1679 return ti->num_discard_bios;
1680}
1681
1682static unsigned get_num_write_same_bios(struct dm_target *ti)
1683{
1684 return ti->num_write_same_bios;
1685}
1686
1687typedef bool (*is_split_required_fn)(struct dm_target *ti);
1688
1689static bool is_split_required_for_discard(struct dm_target *ti)
1690{
1691 return ti->split_discard_bios;
1692}
1693
1694static int __send_changing_extent_only(struct clone_info *ci,
1695 get_num_bios_fn get_num_bios,
1696 is_split_required_fn is_split_required)
1697{
1698 struct dm_target *ti;
1699 unsigned len;
1700 unsigned num_bios;
1701
1702 do {
1703 ti = dm_table_find_target(ci->map, ci->sector);
1704 if (!dm_target_is_valid(ti))
1705 return -EIO;
1706
1707 /*
1708 * Even though the device advertised support for this type of
1709 * request, that does not mean every target supports it, and
1710 * reconfiguration might also have changed that since the
1711 * check was performed.
1712 */
1713 num_bios = get_num_bios ? get_num_bios(ti) : 0;
1714 if (!num_bios)
1715 return -EOPNOTSUPP;
1716
1717 if (is_split_required && !is_split_required(ti))
1718 len = min((sector_t)ci->sector_count, max_io_len_target_boundary(ci->sector, ti));
1719 else
1720 len = min((sector_t)ci->sector_count, max_io_len(ci->sector, ti));
1721
1722 __send_duplicate_bios(ci, ti, num_bios, &len);
1723
1724 ci->sector += len;
1725 } while (ci->sector_count -= len);
1726
1727 return 0;
1728}
1729
1730static int __send_discard(struct clone_info *ci)
1731{
1732 return __send_changing_extent_only(ci, get_num_discard_bios,
1733 is_split_required_for_discard);
1734}
1735
1736static int __send_write_same(struct clone_info *ci)
1737{
1738 return __send_changing_extent_only(ci, get_num_write_same_bios, NULL);
1739}
1740
1741/*
1742 * Select the correct strategy for processing a non-flush bio.
1743 */
1744static int __split_and_process_non_flush(struct clone_info *ci)
1745{
1746 struct bio *bio = ci->bio;
1747 struct dm_target *ti;
1748 unsigned len;
1749 int r;
1750
1751 if (unlikely(bio->bi_rw & REQ_DISCARD))
1752 return __send_discard(ci);
1753 else if (unlikely(bio->bi_rw & REQ_WRITE_SAME))
1754 return __send_write_same(ci);
1755
1756 ti = dm_table_find_target(ci->map, ci->sector);
1757 if (!dm_target_is_valid(ti))
1758 return -EIO;
1759
1760 len = min_t(sector_t, max_io_len(ci->sector, ti), ci->sector_count);
1761
1762 r = __clone_and_map_data_bio(ci, ti, ci->sector, &len);
1763 if (r < 0)
1764 return r;
1765
1766 ci->sector += len;
1767 ci->sector_count -= len;
1768
1769 return 0;
1770}
1771
1772/*
1773 * Entry point to split a bio into clones and submit them to the targets.
1774 */
1775static void __split_and_process_bio(struct mapped_device *md,
1776 struct dm_table *map, struct bio *bio)
1777{
1778 struct clone_info ci;
1779 int error = 0;
1780
1781 if (unlikely(!map)) {
1782 bio_io_error(bio);
1783 return;
1784 }
1785
1786 ci.map = map;
1787 ci.md = md;
1788 ci.io = alloc_io(md);
1789 ci.io->error = 0;
1790 atomic_set(&ci.io->io_count, 1);
1791 ci.io->bio = bio;
1792 ci.io->md = md;
1793 spin_lock_init(&ci.io->endio_lock);
1794 ci.sector = bio->bi_iter.bi_sector;
1795
1796 start_io_acct(ci.io);
1797
1798 if (bio->bi_rw & REQ_FLUSH) {
1799 ci.bio = &ci.md->flush_bio;
1800 ci.sector_count = 0;
1801 error = __send_empty_flush(&ci);
1802 /* dec_pending submits any data associated with flush */
1803 } else {
1804 ci.bio = bio;
1805 ci.sector_count = bio_sectors(bio);
1806 while (ci.sector_count && !error)
1807 error = __split_and_process_non_flush(&ci);
1808 }
1809
1810 /* drop the extra reference count */
1811 dec_pending(ci.io, error);
1812}
1813/*-----------------------------------------------------------------
1814 * CRUD END
1815 *---------------------------------------------------------------*/
1816
1817/*
1818 * The request function that just remaps the bio built up by
1819 * dm_merge_bvec.
1820 */
1821static blk_qc_t dm_make_request(struct request_queue *q, struct bio *bio)
1822{
1823 int rw = bio_data_dir(bio);
1824 struct mapped_device *md = q->queuedata;
1825 int srcu_idx;
1826 struct dm_table *map;
1827
1828 map = dm_get_live_table(md, &srcu_idx);
1829
1830 generic_start_io_acct(rw, bio_sectors(bio), &dm_disk(md)->part0);
1831
1832 /* if we're suspended, we have to queue this io for later */
1833 if (unlikely(test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags))) {
1834 dm_put_live_table(md, srcu_idx);
1835
1836 if (bio_rw(bio) != READA)
1837 queue_io(md, bio);
1838 else
1839 bio_io_error(bio);
1840 return BLK_QC_T_NONE;
1841 }
1842
1843 __split_and_process_bio(md, map, bio);
1844 dm_put_live_table(md, srcu_idx);
1845 return BLK_QC_T_NONE;
1846}
1847
1848int dm_request_based(struct mapped_device *md)
1849{
1850 return blk_queue_stackable(md->queue);
1851}
1852
1853static void dm_dispatch_clone_request(struct request *clone, struct request *rq)
1854{
1855 int r;
1856
1857 if (blk_queue_io_stat(clone->q))
1858 clone->cmd_flags |= REQ_IO_STAT;
1859
1860 clone->start_time = jiffies;
1861 r = blk_insert_cloned_request(clone->q, clone);
1862 if (r)
1863 /* must complete clone in terms of original request */
1864 dm_complete_request(rq, r);
1865}
1866
1867static int dm_rq_bio_constructor(struct bio *bio, struct bio *bio_orig,
1868 void *data)
1869{
1870 struct dm_rq_target_io *tio = data;
1871 struct dm_rq_clone_bio_info *info =
1872 container_of(bio, struct dm_rq_clone_bio_info, clone);
1873
1874 info->orig = bio_orig;
1875 info->tio = tio;
1876 bio->bi_end_io = end_clone_bio;
1877
1878 return 0;
1879}
1880
1881static int setup_clone(struct request *clone, struct request *rq,
1882 struct dm_rq_target_io *tio, gfp_t gfp_mask)
1883{
1884 int r;
1885
1886 r = blk_rq_prep_clone(clone, rq, tio->md->bs, gfp_mask,
1887 dm_rq_bio_constructor, tio);
1888 if (r)
1889 return r;
1890
1891 clone->cmd = rq->cmd;
1892 clone->cmd_len = rq->cmd_len;
1893 clone->sense = rq->sense;
1894 clone->end_io = end_clone_request;
1895 clone->end_io_data = tio;
1896
1897 tio->clone = clone;
1898
1899 return 0;
1900}
1901
1902static struct request *clone_old_rq(struct request *rq, struct mapped_device *md,
1903 struct dm_rq_target_io *tio, gfp_t gfp_mask)
1904{
1905 /*
1906 * Create clone for use with .request_fn request_queue
1907 */
1908 struct request *clone;
1909
1910 clone = alloc_old_clone_request(md, gfp_mask);
1911 if (!clone)
1912 return NULL;
1913
1914 blk_rq_init(NULL, clone);
1915 if (setup_clone(clone, rq, tio, gfp_mask)) {
1916 /* -ENOMEM */
1917 free_old_clone_request(md, clone);
1918 return NULL;
1919 }
1920
1921 return clone;
1922}
1923
1924static void map_tio_request(struct kthread_work *work);
1925
1926static void init_tio(struct dm_rq_target_io *tio, struct request *rq,
1927 struct mapped_device *md)
1928{
1929 tio->md = md;
1930 tio->ti = NULL;
1931 tio->clone = NULL;
1932 tio->orig = rq;
1933 tio->error = 0;
1934 /*
1935 * Avoid initializing info for blk-mq; it passes
1936 * target-specific data through info.ptr
1937 * (see: dm_mq_init_request)
1938 */
1939 if (!md->init_tio_pdu)
1940 memset(&tio->info, 0, sizeof(tio->info));
1941 if (md->kworker_task)
1942 init_kthread_work(&tio->work, map_tio_request);
1943}
1944
1945static struct dm_rq_target_io *dm_old_prep_tio(struct request *rq,
1946 struct mapped_device *md,
1947 gfp_t gfp_mask)
1948{
1949 struct dm_rq_target_io *tio;
1950 int srcu_idx;
1951 struct dm_table *table;
1952
1953 tio = alloc_old_rq_tio(md, gfp_mask);
1954 if (!tio)
1955 return NULL;
1956
1957 init_tio(tio, rq, md);
1958
1959 table = dm_get_live_table(md, &srcu_idx);
1960 /*
1961 * Must clone a request if this .request_fn DM device
1962 * is stacked on .request_fn device(s).
1963 */
1964 if (!dm_table_mq_request_based(table)) {
1965 if (!clone_old_rq(rq, md, tio, gfp_mask)) {
1966 dm_put_live_table(md, srcu_idx);
1967 free_old_rq_tio(tio);
1968 return NULL;
1969 }
1970 }
1971 dm_put_live_table(md, srcu_idx);
1972
1973 return tio;
1974}
1975
1976/*
1977 * Called with the queue lock held.
1978 */
1979static int dm_old_prep_fn(struct request_queue *q, struct request *rq)
1980{
1981 struct mapped_device *md = q->queuedata;
1982 struct dm_rq_target_io *tio;
1983
1984 if (unlikely(rq->special)) {
1985 DMWARN("Already has something in rq->special.");
1986 return BLKPREP_KILL;
1987 }
1988
1989 tio = dm_old_prep_tio(rq, md, GFP_ATOMIC);
1990 if (!tio)
1991 return BLKPREP_DEFER;
1992
1993 rq->special = tio;
1994 rq->cmd_flags |= REQ_DONTPREP;
1995
1996 return BLKPREP_OK;
1997}
1998
1999/*
2000 * Returns:
2001 * 0 : the request has been processed
2002 * DM_MAPIO_REQUEUE : the original request needs to be requeued
2003 * < 0 : the request was completed due to failure
2004 */
2005static int map_request(struct dm_rq_target_io *tio, struct request *rq,
2006 struct mapped_device *md)
2007{
2008 int r;
2009 struct dm_target *ti = tio->ti;
2010 struct request *clone = NULL;
2011
2012 if (tio->clone) {
2013 clone = tio->clone;
2014 r = ti->type->map_rq(ti, clone, &tio->info);
2015 } else {
2016 r = ti->type->clone_and_map_rq(ti, rq, &tio->info, &clone);
2017 if (r < 0) {
2018 /* The target wants to complete the I/O */
2019 dm_kill_unmapped_request(rq, r);
2020 return r;
2021 }
2022 if (r != DM_MAPIO_REMAPPED)
2023 return r;
2024 if (setup_clone(clone, rq, tio, GFP_ATOMIC)) {
2025 /* -ENOMEM */
2026 ti->type->release_clone_rq(clone);
2027 return DM_MAPIO_REQUEUE;
2028 }
2029 }
2030
2031 switch (r) {
2032 case DM_MAPIO_SUBMITTED:
2033 /* The target has taken the I/O to submit by itself later */
2034 break;
2035 case DM_MAPIO_REMAPPED:
2036 /* The target has remapped the I/O so dispatch it */
2037 trace_block_rq_remap(clone->q, clone, disk_devt(dm_disk(md)),
2038 blk_rq_pos(rq));
2039 dm_dispatch_clone_request(clone, rq);
2040 break;
2041 case DM_MAPIO_REQUEUE:
2042 /* The target wants to requeue the I/O */
2043 dm_requeue_original_request(md, tio->orig);
2044 break;
2045 default:
2046 if (r > 0) {
2047 DMWARN("unimplemented target map return value: %d", r);
2048 BUG();
2049 }
2050
2051 /* The target wants to complete the I/O */
2052 dm_kill_unmapped_request(rq, r);
2053 return r;
2054 }
2055
2056 return 0;
2057}
2058
2059static void map_tio_request(struct kthread_work *work)
2060{
2061 struct dm_rq_target_io *tio = container_of(work, struct dm_rq_target_io, work);
2062 struct request *rq = tio->orig;
2063 struct mapped_device *md = tio->md;
2064
2065 if (map_request(tio, rq, md) == DM_MAPIO_REQUEUE)
2066 dm_requeue_original_request(md, rq);
2067}
2068
2069static void dm_start_request(struct mapped_device *md, struct request *orig)
2070{
2071 if (!orig->q->mq_ops)
2072 blk_start_request(orig);
2073 else
2074 blk_mq_start_request(orig);
2075 atomic_inc(&md->pending[rq_data_dir(orig)]);
2076
2077 if (md->seq_rq_merge_deadline_usecs) {
2078 md->last_rq_pos = rq_end_sector(orig);
2079 md->last_rq_rw = rq_data_dir(orig);
2080 md->last_rq_start_time = ktime_get();
2081 }
2082
2083 if (unlikely(dm_stats_used(&md->stats))) {
2084 struct dm_rq_target_io *tio = tio_from_request(orig);
2085 tio->duration_jiffies = jiffies;
2086 tio->n_sectors = blk_rq_sectors(orig);
2087 dm_stats_account_io(&md->stats, orig->cmd_flags, blk_rq_pos(orig),
2088 tio->n_sectors, false, 0, &tio->stats_aux);
2089 }
2090
2091 /*
2092 * Hold the md reference here for the in-flight I/O.
2093 * We can't rely on the reference count by device opener,
2094 * because the device may be closed during the request completion
2095 * when all bios are completed.
2096 * See the comment in rq_completed() too.
2097 */
2098 dm_get(md);
2099}
2100
2101#define MAX_SEQ_RQ_MERGE_DEADLINE_USECS 100000
2102
2103ssize_t dm_attr_rq_based_seq_io_merge_deadline_show(struct mapped_device *md, char *buf)
2104{
2105 return sprintf(buf, "%u\n", md->seq_rq_merge_deadline_usecs);
2106}
2107
2108ssize_t dm_attr_rq_based_seq_io_merge_deadline_store(struct mapped_device *md,
2109 const char *buf, size_t count)
2110{
2111 unsigned deadline;
2112
2113 if (!dm_request_based(md) || md->use_blk_mq)
2114 return count;
2115
2116 if (kstrtouint(buf, 10, &deadline))
2117 return -EINVAL;
2118
2119 if (deadline > MAX_SEQ_RQ_MERGE_DEADLINE_USECS)
2120 deadline = MAX_SEQ_RQ_MERGE_DEADLINE_USECS;
2121
2122 md->seq_rq_merge_deadline_usecs = deadline;
2123
2124 return count;
2125}
2126
2127static bool dm_request_peeked_before_merge_deadline(struct mapped_device *md)
2128{
2129 ktime_t kt_deadline;
2130
2131 if (!md->seq_rq_merge_deadline_usecs)
2132 return false;
2133
2134 kt_deadline = ns_to_ktime((u64)md->seq_rq_merge_deadline_usecs * NSEC_PER_USEC);
2135 kt_deadline = ktime_add_safe(md->last_rq_start_time, kt_deadline);
2136
2137 return !ktime_after(ktime_get(), kt_deadline);
2138}
2139
2140/*
2141 * q->request_fn for request-based dm.
2142 * Called with the queue lock held.
2143 */
2144static void dm_request_fn(struct request_queue *q)
2145{
2146 struct mapped_device *md = q->queuedata;
2147 struct dm_target *ti = md->immutable_target;
2148 struct request *rq;
2149 struct dm_rq_target_io *tio;
2150 sector_t pos = 0;
2151
2152 if (unlikely(!ti)) {
2153 int srcu_idx;
2154 struct dm_table *map = dm_get_live_table(md, &srcu_idx);
2155
2156 ti = dm_table_find_target(map, pos);
2157 dm_put_live_table(md, srcu_idx);
2158 }
2159
2160 /*
2161 * For suspend, check blk_queue_stopped() and increment
2162 * ->pending within a single queue_lock not to increment the
2163 * number of in-flight I/Os after the queue is stopped in
2164 * dm_suspend().
2165 */
2166 while (!blk_queue_stopped(q)) {
2167 rq = blk_peek_request(q);
2168 if (!rq)
2169 return;
2170
2171 /* always use block 0 to find the target for flushes for now */
2172 pos = 0;
2173 if (!(rq->cmd_flags & REQ_FLUSH))
2174 pos = blk_rq_pos(rq);
2175
2176 if ((dm_request_peeked_before_merge_deadline(md) &&
2177 md_in_flight(md) && rq->bio && rq->bio->bi_vcnt == 1 &&
2178 md->last_rq_pos == pos && md->last_rq_rw == rq_data_dir(rq)) ||
2179 (ti->type->busy && ti->type->busy(ti))) {
2180 blk_delay_queue(q, HZ / 100);
2181 return;
2182 }
2183
2184 dm_start_request(md, rq);
2185
2186 tio = tio_from_request(rq);
2187 /* Establish tio->ti before queuing work (map_tio_request) */
2188 tio->ti = ti;
2189 queue_kthread_work(&md->kworker, &tio->work);
2190 BUG_ON(!irqs_disabled());
2191 }
2192}
2193
2194static int dm_any_congested(void *congested_data, int bdi_bits)
2195{
2196 int r = bdi_bits;
2197 struct mapped_device *md = congested_data;
2198 struct dm_table *map;
2199
2200 if (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) {
2201 if (dm_request_based(md)) {
2202 /*
2203 * With request-based DM we only need to check the
2204 * top-level queue for congestion.
2205 */
2206 r = md->queue->backing_dev_info.wb.state & bdi_bits;
2207 } else {
2208 map = dm_get_live_table_fast(md);
2209 if (map)
2210 r = dm_table_any_congested(map, bdi_bits);
2211 dm_put_live_table_fast(md);
2212 }
2213 }
2214
2215 return r;
2216}
2217
2218/*-----------------------------------------------------------------
2219 * An IDR is used to keep track of allocated minor numbers.
2220 *---------------------------------------------------------------*/
2221static void free_minor(int minor)
2222{
2223 spin_lock(&_minor_lock);
2224 idr_remove(&_minor_idr, minor);
2225 spin_unlock(&_minor_lock);
2226}
2227
2228/*
2229 * See if the device with a specific minor # is free.
2230 */
2231static int specific_minor(int minor)
2232{
2233 int r;
2234
2235 if (minor >= (1 << MINORBITS))
2236 return -EINVAL;
2237
2238 idr_preload(GFP_KERNEL);
2239 spin_lock(&_minor_lock);
2240
2241 r = idr_alloc(&_minor_idr, MINOR_ALLOCED, minor, minor + 1, GFP_NOWAIT);
2242
2243 spin_unlock(&_minor_lock);
2244 idr_preload_end();
2245 if (r < 0)
2246 return r == -ENOSPC ? -EBUSY : r;
2247 return 0;
2248}
2249
2250static int next_free_minor(int *minor)
2251{
2252 int r;
2253
2254 idr_preload(GFP_KERNEL);
2255 spin_lock(&_minor_lock);
2256
2257 r = idr_alloc(&_minor_idr, MINOR_ALLOCED, 0, 1 << MINORBITS, GFP_NOWAIT);
2258
2259 spin_unlock(&_minor_lock);
2260 idr_preload_end();
2261 if (r < 0)
2262 return r;
2263 *minor = r;
2264 return 0;
2265}
2266
2267static const struct block_device_operations dm_blk_dops;
2268
2269static void dm_wq_work(struct work_struct *work);
2270
2271static void dm_init_md_queue(struct mapped_device *md)
2272{
2273 /*
2274 * Request-based dm devices cannot be stacked on top of bio-based dm
2275 * devices. The type of this dm device may not have been decided yet.
2276 * The type is decided at the first table loading time.
2277 * To prevent problematic device stacking, clear the queue flag
2278 * for request stacking support until then.
2279 *
2280 * This queue is new, so no concurrency on the queue_flags.
2281 */
2282 queue_flag_clear_unlocked(QUEUE_FLAG_STACKABLE, md->queue);
2283
2284 /*
2285 * Initialize data that will only be used by a non-blk-mq DM queue
2286 * - must do so here (in alloc_dev callchain) before queue is used
2287 */
2288 md->queue->queuedata = md;
2289 md->queue->backing_dev_info.congested_data = md;
2290}
2291
2292static void dm_init_normal_md_queue(struct mapped_device *md)
2293{
2294 md->use_blk_mq = false;
2295 dm_init_md_queue(md);
2296
2297 /*
2298 * Initialize aspects of queue that aren't relevant for blk-mq
2299 */
2300 md->queue->backing_dev_info.congested_fn = dm_any_congested;
2301 blk_queue_bounce_limit(md->queue, BLK_BOUNCE_ANY);
2302}
2303
2304static void cleanup_mapped_device(struct mapped_device *md)
2305{
2306 if (md->wq)
2307 destroy_workqueue(md->wq);
2308 if (md->kworker_task)
2309 kthread_stop(md->kworker_task);
2310 mempool_destroy(md->io_pool);
2311 mempool_destroy(md->rq_pool);
2312 if (md->bs)
2313 bioset_free(md->bs);
2314
2315 cleanup_srcu_struct(&md->io_barrier);
2316
2317 if (md->disk) {
2318 spin_lock(&_minor_lock);
2319 md->disk->private_data = NULL;
2320 spin_unlock(&_minor_lock);
2321 del_gendisk(md->disk);
2322 put_disk(md->disk);
2323 }
2324
2325 if (md->queue)
2326 blk_cleanup_queue(md->queue);
2327
2328 if (md->bdev) {
2329 bdput(md->bdev);
2330 md->bdev = NULL;
2331 }
2332}
2333
2334/*
2335 * Allocate and initialise a blank device with a given minor.
2336 */
2337static struct mapped_device *alloc_dev(int minor)
2338{
2339 int r, numa_node_id = dm_get_numa_node();
2340 struct mapped_device *md;
2341 void *old_md;
2342
2343 md = kzalloc_node(sizeof(*md), GFP_KERNEL, numa_node_id);
2344 if (!md) {
2345 DMWARN("unable to allocate device, out of memory.");
2346 return NULL;
2347 }
2348
2349 if (!try_module_get(THIS_MODULE))
2350 goto bad_module_get;
2351
2352 /* get a minor number for the dev */
2353 if (minor == DM_ANY_MINOR)
2354 r = next_free_minor(&minor);
2355 else
2356 r = specific_minor(minor);
2357 if (r < 0)
2358 goto bad_minor;
2359
2360 r = init_srcu_struct(&md->io_barrier);
2361 if (r < 0)
2362 goto bad_io_barrier;
2363
2364 md->numa_node_id = numa_node_id;
2365 md->use_blk_mq = use_blk_mq;
2366 md->init_tio_pdu = false;
2367 md->type = DM_TYPE_NONE;
2368 mutex_init(&md->suspend_lock);
2369 mutex_init(&md->type_lock);
2370 mutex_init(&md->table_devices_lock);
2371 spin_lock_init(&md->deferred_lock);
2372 atomic_set(&md->holders, 1);
2373 atomic_set(&md->open_count, 0);
2374 atomic_set(&md->event_nr, 0);
2375 atomic_set(&md->uevent_seq, 0);
2376 INIT_LIST_HEAD(&md->uevent_list);
2377 INIT_LIST_HEAD(&md->table_devices);
2378 spin_lock_init(&md->uevent_lock);
2379
2380 md->queue = blk_alloc_queue_node(GFP_KERNEL, numa_node_id);
2381 if (!md->queue)
2382 goto bad;
2383
2384 dm_init_md_queue(md);
2385
2386 md->disk = alloc_disk_node(1, numa_node_id);
2387 if (!md->disk)
2388 goto bad;
2389
2390 atomic_set(&md->pending[0], 0);
2391 atomic_set(&md->pending[1], 0);
2392 init_waitqueue_head(&md->wait);
2393 INIT_WORK(&md->work, dm_wq_work);
2394 init_waitqueue_head(&md->eventq);
2395 init_completion(&md->kobj_holder.completion);
2396 md->kworker_task = NULL;
2397
2398 md->disk->major = _major;
2399 md->disk->first_minor = minor;
2400 md->disk->fops = &dm_blk_dops;
2401 md->disk->queue = md->queue;
2402 md->disk->private_data = md;
2403 sprintf(md->disk->disk_name, "dm-%d", minor);
2404 add_disk(md->disk);
2405 format_dev_t(md->name, MKDEV(_major, minor));
2406
2407 md->wq = alloc_workqueue("kdmflush", WQ_MEM_RECLAIM, 0);
2408 if (!md->wq)
2409 goto bad;
2410
2411 md->bdev = bdget_disk(md->disk, 0);
2412 if (!md->bdev)
2413 goto bad;
2414
2415 bio_init(&md->flush_bio);
2416 md->flush_bio.bi_bdev = md->bdev;
2417 md->flush_bio.bi_rw = WRITE_FLUSH;
2418
2419 dm_stats_init(&md->stats);
2420
2421 /* Populate the mapping, nobody knows we exist yet */
2422 spin_lock(&_minor_lock);
2423 old_md = idr_replace(&_minor_idr, md, minor);
2424 spin_unlock(&_minor_lock);
2425
2426 BUG_ON(old_md != MINOR_ALLOCED);
2427
2428 return md;
2429
2430bad:
2431 cleanup_mapped_device(md);
2432bad_io_barrier:
2433 free_minor(minor);
2434bad_minor:
2435 module_put(THIS_MODULE);
2436bad_module_get:
2437 kfree(md);
2438 return NULL;
2439}
2440
2441static void unlock_fs(struct mapped_device *md);
2442
2443static void free_dev(struct mapped_device *md)
2444{
2445 int minor = MINOR(disk_devt(md->disk));
2446
2447 unlock_fs(md);
2448
2449 cleanup_mapped_device(md);
2450 if (md->tag_set) {
2451 blk_mq_free_tag_set(md->tag_set);
2452 kfree(md->tag_set);
2453 }
2454
2455 free_table_devices(&md->table_devices);
2456 dm_stats_cleanup(&md->stats);
2457 free_minor(minor);
2458
2459 module_put(THIS_MODULE);
2460 kfree(md);
2461}
2462
2463static void __bind_mempools(struct mapped_device *md, struct dm_table *t)
2464{
2465 struct dm_md_mempools *p = dm_table_get_md_mempools(t);
2466
2467 if (md->bs) {
2468 /* The md already has necessary mempools. */
2469 if (dm_table_get_type(t) == DM_TYPE_BIO_BASED) {
2470 /*
2471 * Reload bioset because front_pad may have changed
2472 * because a different table was loaded.
2473 */
2474 bioset_free(md->bs);
2475 md->bs = p->bs;
2476 p->bs = NULL;
2477 }
2478 /*
2479 * There's no need to reload with request-based dm
2480 * because the size of front_pad doesn't change.
2481 * Note for future: If you are to reload bioset,
2482 * prep-ed requests in the queue may refer
2483 * to bio from the old bioset, so you must walk
2484 * through the queue to unprep.
2485 */
2486 goto out;
2487 }
2488
2489 BUG_ON(!p || md->io_pool || md->rq_pool || md->bs);
2490
2491 md->io_pool = p->io_pool;
2492 p->io_pool = NULL;
2493 md->rq_pool = p->rq_pool;
2494 p->rq_pool = NULL;
2495 md->bs = p->bs;
2496 p->bs = NULL;
2497
2498out:
2499 /* mempool bind completed, no longer need any mempools in the table */
2500 dm_table_free_md_mempools(t);
2501}
2502
2503/*
2504 * Bind a table to the device.
2505 */
2506static void event_callback(void *context)
2507{
2508 unsigned long flags;
2509 LIST_HEAD(uevents);
2510 struct mapped_device *md = (struct mapped_device *) context;
2511
2512 spin_lock_irqsave(&md->uevent_lock, flags);
2513 list_splice_init(&md->uevent_list, &uevents);
2514 spin_unlock_irqrestore(&md->uevent_lock, flags);
2515
2516 dm_send_uevents(&uevents, &disk_to_dev(md->disk)->kobj);
2517
2518 atomic_inc(&md->event_nr);
2519 wake_up(&md->eventq);
2520}
2521
2522/*
2523 * Protected by md->suspend_lock obtained by dm_swap_table().
2524 */
2525static void __set_size(struct mapped_device *md, sector_t size)
2526{
2527 set_capacity(md->disk, size);
2528
2529 i_size_write(md->bdev->bd_inode, (loff_t)size << SECTOR_SHIFT);
2530}
2531
2532/*
2533 * Returns old map, which caller must destroy.
2534 */
2535static struct dm_table *__bind(struct mapped_device *md, struct dm_table *t,
2536 struct queue_limits *limits)
2537{
2538 struct dm_table *old_map;
2539 struct request_queue *q = md->queue;
2540 sector_t size;
2541
2542 size = dm_table_get_size(t);
2543
2544 /*
2545 * Wipe any geometry if the size of the table changed.
2546 */
2547 if (size != dm_get_size(md))
2548 memset(&md->geometry, 0, sizeof(md->geometry));
2549
2550 __set_size(md, size);
2551
2552 dm_table_event_callback(t, event_callback, md);
2553
2554 /*
2555 * The queue hasn't been stopped yet, if the old table type wasn't
2556 * for request-based during suspension. So stop it to prevent
2557 * I/O mapping before resume.
2558 * This must be done before setting the queue restrictions,
2559 * because request-based dm may be run just after the setting.
2560 */
2561 if (dm_table_request_based(t)) {
2562 dm_stop_queue(q);
2563 /*
2564 * Leverage the fact that request-based DM targets are
2565 * immutable singletons and establish md->immutable_target
2566 * - used to optimize both dm_request_fn and dm_mq_queue_rq
2567 */
2568 md->immutable_target = dm_table_get_immutable_target(t);
2569 }
2570
2571 __bind_mempools(md, t);
2572
2573 old_map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock));
2574 rcu_assign_pointer(md->map, (void *)t);
2575 md->immutable_target_type = dm_table_get_immutable_target_type(t);
2576
2577 dm_table_set_restrictions(t, q, limits);
2578 if (old_map)
2579 dm_sync_table(md);
2580
2581 return old_map;
2582}
2583
2584/*
2585 * Returns unbound table for the caller to free.
2586 */
2587static struct dm_table *__unbind(struct mapped_device *md)
2588{
2589 struct dm_table *map = rcu_dereference_protected(md->map, 1);
2590
2591 if (!map)
2592 return NULL;
2593
2594 dm_table_event_callback(map, NULL, NULL);
2595 RCU_INIT_POINTER(md->map, NULL);
2596 dm_sync_table(md);
2597
2598 return map;
2599}
2600
2601/*
2602 * Constructor for a new device.
2603 */
2604int dm_create(int minor, struct mapped_device **result)
2605{
2606 struct mapped_device *md;
2607
2608 md = alloc_dev(minor);
2609 if (!md)
2610 return -ENXIO;
2611
2612 dm_sysfs_init(md);
2613
2614 *result = md;
2615 return 0;
2616}
2617
2618/*
2619 * Functions to manage md->type.
2620 * All are required to hold md->type_lock.
2621 */
2622void dm_lock_md_type(struct mapped_device *md)
2623{
2624 mutex_lock(&md->type_lock);
2625}
2626
2627void dm_unlock_md_type(struct mapped_device *md)
2628{
2629 mutex_unlock(&md->type_lock);
2630}
2631
2632void dm_set_md_type(struct mapped_device *md, unsigned type)
2633{
2634 BUG_ON(!mutex_is_locked(&md->type_lock));
2635 md->type = type;
2636}
2637
2638unsigned dm_get_md_type(struct mapped_device *md)
2639{
2640 return md->type;
2641}
2642
2643struct target_type *dm_get_immutable_target_type(struct mapped_device *md)
2644{
2645 return md->immutable_target_type;
2646}
2647
2648/*
2649 * The queue_limits are only valid as long as you have a reference
2650 * count on 'md'.
2651 */
2652struct queue_limits *dm_get_queue_limits(struct mapped_device *md)
2653{
2654 BUG_ON(!atomic_read(&md->holders));
2655 return &md->queue->limits;
2656}
2657EXPORT_SYMBOL_GPL(dm_get_queue_limits);
2658
2659static void dm_old_init_rq_based_worker_thread(struct mapped_device *md)
2660{
2661 /* Initialize the request-based DM worker thread */
2662 init_kthread_worker(&md->kworker);
2663 md->kworker_task = kthread_run(kthread_worker_fn, &md->kworker,
2664 "kdmwork-%s", dm_device_name(md));
2665}
2666
2667/*
2668 * Fully initialize a .request_fn request-based queue.
2669 */
2670static int dm_old_init_request_queue(struct mapped_device *md)
2671{
2672 /* Fully initialize the queue */
2673 if (!blk_init_allocated_queue(md->queue, dm_request_fn, NULL))
2674 return -EINVAL;
2675
2676 /* disable dm_request_fn's merge heuristic by default */
2677 md->seq_rq_merge_deadline_usecs = 0;
2678
2679 dm_init_normal_md_queue(md);
2680 blk_queue_softirq_done(md->queue, dm_softirq_done);
2681 blk_queue_prep_rq(md->queue, dm_old_prep_fn);
2682
2683 dm_old_init_rq_based_worker_thread(md);
2684
2685 elv_register_queue(md->queue);
2686
2687 return 0;
2688}
2689
2690static int dm_mq_init_request(void *data, struct request *rq,
2691 unsigned int hctx_idx, unsigned int request_idx,
2692 unsigned int numa_node)
2693{
2694 struct mapped_device *md = data;
2695 struct dm_rq_target_io *tio = blk_mq_rq_to_pdu(rq);
2696
2697 /*
2698 * Must initialize md member of tio, otherwise it won't
2699 * be available in dm_mq_queue_rq.
2700 */
2701 tio->md = md;
2702
2703 if (md->init_tio_pdu) {
2704 /* target-specific per-io data is immediately after the tio */
2705 tio->info.ptr = tio + 1;
2706 }
2707
2708 return 0;
2709}
2710
2711static int dm_mq_queue_rq(struct blk_mq_hw_ctx *hctx,
2712 const struct blk_mq_queue_data *bd)
2713{
2714 struct request *rq = bd->rq;
2715 struct dm_rq_target_io *tio = blk_mq_rq_to_pdu(rq);
2716 struct mapped_device *md = tio->md;
2717 struct dm_target *ti = md->immutable_target;
2718
2719 if (unlikely(!ti)) {
2720 int srcu_idx;
2721 struct dm_table *map = dm_get_live_table(md, &srcu_idx);
2722
2723 ti = dm_table_find_target(map, 0);
2724 dm_put_live_table(md, srcu_idx);
2725 }
2726
2727 if (ti->type->busy && ti->type->busy(ti))
2728 return BLK_MQ_RQ_QUEUE_BUSY;
2729
2730 dm_start_request(md, rq);
2731
2732 /* Init tio using md established in .init_request */
2733 init_tio(tio, rq, md);
2734
2735 /*
2736 * Establish tio->ti before queuing work (map_tio_request)
2737 * or making direct call to map_request().
2738 */
2739 tio->ti = ti;
2740
2741 /* Direct call is fine since .queue_rq allows allocations */
2742 if (map_request(tio, rq, md) == DM_MAPIO_REQUEUE) {
2743 /* Undo dm_start_request() before requeuing */
2744 rq_end_stats(md, rq);
2745 rq_completed(md, rq_data_dir(rq), false);
2746 return BLK_MQ_RQ_QUEUE_BUSY;
2747 }
2748
2749 return BLK_MQ_RQ_QUEUE_OK;
2750}
2751
2752static struct blk_mq_ops dm_mq_ops = {
2753 .queue_rq = dm_mq_queue_rq,
2754 .map_queue = blk_mq_map_queue,
2755 .complete = dm_softirq_done,
2756 .init_request = dm_mq_init_request,
2757};
2758
2759static int dm_mq_init_request_queue(struct mapped_device *md,
2760 struct dm_target *immutable_tgt)
2761{
2762 struct request_queue *q;
2763 int err;
2764
2765 if (dm_get_md_type(md) == DM_TYPE_REQUEST_BASED) {
2766 DMERR("request-based dm-mq may only be stacked on blk-mq device(s)");
2767 return -EINVAL;
2768 }
2769
2770 md->tag_set = kzalloc_node(sizeof(struct blk_mq_tag_set), GFP_KERNEL, md->numa_node_id);
2771 if (!md->tag_set)
2772 return -ENOMEM;
2773
2774 md->tag_set->ops = &dm_mq_ops;
2775 md->tag_set->queue_depth = dm_get_blk_mq_queue_depth();
2776 md->tag_set->numa_node = md->numa_node_id;
2777 md->tag_set->flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_SG_MERGE;
2778 md->tag_set->nr_hw_queues = dm_get_blk_mq_nr_hw_queues();
2779 md->tag_set->driver_data = md;
2780
2781 md->tag_set->cmd_size = sizeof(struct dm_rq_target_io);
2782 if (immutable_tgt && immutable_tgt->per_io_data_size) {
2783 /* any target-specific per-io data is immediately after the tio */
2784 md->tag_set->cmd_size += immutable_tgt->per_io_data_size;
2785 md->init_tio_pdu = true;
2786 }
2787
2788 err = blk_mq_alloc_tag_set(md->tag_set);
2789 if (err)
2790 goto out_kfree_tag_set;
2791
2792 q = blk_mq_init_allocated_queue(md->tag_set, md->queue);
2793 if (IS_ERR(q)) {
2794 err = PTR_ERR(q);
2795 goto out_tag_set;
2796 }
2797 dm_init_md_queue(md);
2798
2799 /* backfill 'mq' sysfs registration normally done in blk_register_queue */
2800 blk_mq_register_disk(md->disk);
2801
2802 return 0;
2803
2804out_tag_set:
2805 blk_mq_free_tag_set(md->tag_set);
2806out_kfree_tag_set:
2807 kfree(md->tag_set);
2808
2809 return err;
2810}
2811
2812static unsigned filter_md_type(unsigned type, struct mapped_device *md)
2813{
2814 if (type == DM_TYPE_BIO_BASED)
2815 return type;
2816
2817 return !md->use_blk_mq ? DM_TYPE_REQUEST_BASED : DM_TYPE_MQ_REQUEST_BASED;
2818}
2819
2820/*
2821 * Setup the DM device's queue based on md's type
2822 */
2823int dm_setup_md_queue(struct mapped_device *md, struct dm_table *t)
2824{
2825 int r;
2826 unsigned md_type = filter_md_type(dm_get_md_type(md), md);
2827
2828 switch (md_type) {
2829 case DM_TYPE_REQUEST_BASED:
2830 r = dm_old_init_request_queue(md);
2831 if (r) {
2832 DMERR("Cannot initialize queue for request-based mapped device");
2833 return r;
2834 }
2835 break;
2836 case DM_TYPE_MQ_REQUEST_BASED:
2837 r = dm_mq_init_request_queue(md, dm_table_get_immutable_target(t));
2838 if (r) {
2839 DMERR("Cannot initialize queue for request-based dm-mq mapped device");
2840 return r;
2841 }
2842 break;
2843 case DM_TYPE_BIO_BASED:
2844 dm_init_normal_md_queue(md);
2845 blk_queue_make_request(md->queue, dm_make_request);
2846 /*
2847 * DM handles splitting bios as needed. Free the bio_split bioset
2848 * since it won't be used (saves 1 process per bio-based DM device).
2849 */
2850 bioset_free(md->queue->bio_split);
2851 md->queue->bio_split = NULL;
2852 break;
2853 }
2854
2855 return 0;
2856}
2857
2858struct mapped_device *dm_get_md(dev_t dev)
2859{
2860 struct mapped_device *md;
2861 unsigned minor = MINOR(dev);
2862
2863 if (MAJOR(dev) != _major || minor >= (1 << MINORBITS))
2864 return NULL;
2865
2866 spin_lock(&_minor_lock);
2867
2868 md = idr_find(&_minor_idr, minor);
2869 if (md) {
2870 if ((md == MINOR_ALLOCED ||
2871 (MINOR(disk_devt(dm_disk(md))) != minor) ||
2872 dm_deleting_md(md) ||
2873 test_bit(DMF_FREEING, &md->flags))) {
2874 md = NULL;
2875 goto out;
2876 }
2877 dm_get(md);
2878 }
2879
2880out:
2881 spin_unlock(&_minor_lock);
2882
2883 return md;
2884}
2885EXPORT_SYMBOL_GPL(dm_get_md);
2886
2887void *dm_get_mdptr(struct mapped_device *md)
2888{
2889 return md->interface_ptr;
2890}
2891
2892void dm_set_mdptr(struct mapped_device *md, void *ptr)
2893{
2894 md->interface_ptr = ptr;
2895}
2896
2897void dm_get(struct mapped_device *md)
2898{
2899 atomic_inc(&md->holders);
2900 BUG_ON(test_bit(DMF_FREEING, &md->flags));
2901}
2902
2903int dm_hold(struct mapped_device *md)
2904{
2905 spin_lock(&_minor_lock);
2906 if (test_bit(DMF_FREEING, &md->flags)) {
2907 spin_unlock(&_minor_lock);
2908 return -EBUSY;
2909 }
2910 dm_get(md);
2911 spin_unlock(&_minor_lock);
2912 return 0;
2913}
2914EXPORT_SYMBOL_GPL(dm_hold);
2915
2916const char *dm_device_name(struct mapped_device *md)
2917{
2918 return md->name;
2919}
2920EXPORT_SYMBOL_GPL(dm_device_name);
2921
2922static void __dm_destroy(struct mapped_device *md, bool wait)
2923{
2924 struct dm_table *map;
2925 int srcu_idx;
2926
2927 might_sleep();
2928
2929 spin_lock(&_minor_lock);
2930 idr_replace(&_minor_idr, MINOR_ALLOCED, MINOR(disk_devt(dm_disk(md))));
2931 set_bit(DMF_FREEING, &md->flags);
2932 spin_unlock(&_minor_lock);
2933
2934 if (dm_request_based(md) && md->kworker_task)
2935 flush_kthread_worker(&md->kworker);
2936
2937 /*
2938 * Take suspend_lock so that presuspend and postsuspend methods
2939 * do not race with internal suspend.
2940 */
2941 mutex_lock(&md->suspend_lock);
2942 map = dm_get_live_table(md, &srcu_idx);
2943 if (!dm_suspended_md(md)) {
2944 dm_table_presuspend_targets(map);
2945 dm_table_postsuspend_targets(map);
2946 }
2947 /* dm_put_live_table must be before msleep, otherwise deadlock is possible */
2948 dm_put_live_table(md, srcu_idx);
2949 mutex_unlock(&md->suspend_lock);
2950
2951 /*
2952 * Rare, but there may be I/O requests still going to complete,
2953 * for example. Wait for all references to disappear.
2954 * No one should increment the reference count of the mapped_device,
2955 * after the mapped_device state becomes DMF_FREEING.
2956 */
2957 if (wait)
2958 while (atomic_read(&md->holders))
2959 msleep(1);
2960 else if (atomic_read(&md->holders))
2961 DMWARN("%s: Forcibly removing mapped_device still in use! (%d users)",
2962 dm_device_name(md), atomic_read(&md->holders));
2963
2964 dm_sysfs_exit(md);
2965 dm_table_destroy(__unbind(md));
2966 free_dev(md);
2967}
2968
2969void dm_destroy(struct mapped_device *md)
2970{
2971 __dm_destroy(md, true);
2972}
2973
2974void dm_destroy_immediate(struct mapped_device *md)
2975{
2976 __dm_destroy(md, false);
2977}
2978
2979void dm_put(struct mapped_device *md)
2980{
2981 atomic_dec(&md->holders);
2982}
2983EXPORT_SYMBOL_GPL(dm_put);
2984
2985static int dm_wait_for_completion(struct mapped_device *md, int interruptible)
2986{
2987 int r = 0;
2988 DECLARE_WAITQUEUE(wait, current);
2989
2990 add_wait_queue(&md->wait, &wait);
2991
2992 while (1) {
2993 set_current_state(interruptible);
2994
2995 if (!md_in_flight(md))
2996 break;
2997
2998 if (interruptible == TASK_INTERRUPTIBLE &&
2999 signal_pending(current)) {
3000 r = -EINTR;
3001 break;
3002 }
3003
3004 io_schedule();
3005 }
3006 set_current_state(TASK_RUNNING);
3007
3008 remove_wait_queue(&md->wait, &wait);
3009
3010 return r;
3011}
3012
3013/*
3014 * Process the deferred bios
3015 */
3016static void dm_wq_work(struct work_struct *work)
3017{
3018 struct mapped_device *md = container_of(work, struct mapped_device,
3019 work);
3020 struct bio *c;
3021 int srcu_idx;
3022 struct dm_table *map;
3023
3024 map = dm_get_live_table(md, &srcu_idx);
3025
3026 while (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) {
3027 spin_lock_irq(&md->deferred_lock);
3028 c = bio_list_pop(&md->deferred);
3029 spin_unlock_irq(&md->deferred_lock);
3030
3031 if (!c)
3032 break;
3033
3034 if (dm_request_based(md))
3035 generic_make_request(c);
3036 else
3037 __split_and_process_bio(md, map, c);
3038 }
3039
3040 dm_put_live_table(md, srcu_idx);
3041}
3042
3043static void dm_queue_flush(struct mapped_device *md)
3044{
3045 clear_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags);
3046 smp_mb__after_atomic();
3047 queue_work(md->wq, &md->work);
3048}
3049
3050/*
3051 * Swap in a new table, returning the old one for the caller to destroy.
3052 */
3053struct dm_table *dm_swap_table(struct mapped_device *md, struct dm_table *table)
3054{
3055 struct dm_table *live_map = NULL, *map = ERR_PTR(-EINVAL);
3056 struct queue_limits limits;
3057 int r;
3058
3059 mutex_lock(&md->suspend_lock);
3060
3061 /* device must be suspended */
3062 if (!dm_suspended_md(md))
3063 goto out;
3064
3065 /*
3066 * If the new table has no data devices, retain the existing limits.
3067 * This helps multipath with queue_if_no_path if all paths disappear,
3068 * then new I/O is queued based on these limits, and then some paths
3069 * reappear.
3070 */
3071 if (dm_table_has_no_data_devices(table)) {
3072 live_map = dm_get_live_table_fast(md);
3073 if (live_map)
3074 limits = md->queue->limits;
3075 dm_put_live_table_fast(md);
3076 }
3077
3078 if (!live_map) {
3079 r = dm_calculate_queue_limits(table, &limits);
3080 if (r) {
3081 map = ERR_PTR(r);
3082 goto out;
3083 }
3084 }
3085
3086 map = __bind(md, table, &limits);
3087
3088out:
3089 mutex_unlock(&md->suspend_lock);
3090 return map;
3091}
3092
3093/*
3094 * Functions to lock and unlock any filesystem running on the
3095 * device.
3096 */
3097static int lock_fs(struct mapped_device *md)
3098{
3099 int r;
3100
3101 WARN_ON(md->frozen_sb);
3102
3103 md->frozen_sb = freeze_bdev(md->bdev);
3104 if (IS_ERR(md->frozen_sb)) {
3105 r = PTR_ERR(md->frozen_sb);
3106 md->frozen_sb = NULL;
3107 return r;
3108 }
3109
3110 set_bit(DMF_FROZEN, &md->flags);
3111
3112 return 0;
3113}
3114
3115static void unlock_fs(struct mapped_device *md)
3116{
3117 if (!test_bit(DMF_FROZEN, &md->flags))
3118 return;
3119
3120 thaw_bdev(md->bdev, md->frozen_sb);
3121 md->frozen_sb = NULL;
3122 clear_bit(DMF_FROZEN, &md->flags);
3123}
3124
3125/*
3126 * If __dm_suspend returns 0, the device is completely quiescent
3127 * now. There is no request-processing activity. All new requests
3128 * are being added to md->deferred list.
3129 *
3130 * Caller must hold md->suspend_lock
3131 */
3132static int __dm_suspend(struct mapped_device *md, struct dm_table *map,
3133 unsigned suspend_flags, int interruptible)
3134{
3135 bool do_lockfs = suspend_flags & DM_SUSPEND_LOCKFS_FLAG;
3136 bool noflush = suspend_flags & DM_SUSPEND_NOFLUSH_FLAG;
3137 int r;
3138
3139 /*
3140 * DMF_NOFLUSH_SUSPENDING must be set before presuspend.
3141 * This flag is cleared before dm_suspend returns.
3142 */
3143 if (noflush)
3144 set_bit(DMF_NOFLUSH_SUSPENDING, &md->flags);
3145
3146 /*
3147 * This gets reverted if there's an error later and the targets
3148 * provide the .presuspend_undo hook.
3149 */
3150 dm_table_presuspend_targets(map);
3151
3152 /*
3153 * Flush I/O to the device.
3154 * Any I/O submitted after lock_fs() may not be flushed.
3155 * noflush takes precedence over do_lockfs.
3156 * (lock_fs() flushes I/Os and waits for them to complete.)
3157 */
3158 if (!noflush && do_lockfs) {
3159 r = lock_fs(md);
3160 if (r) {
3161 dm_table_presuspend_undo_targets(map);
3162 return r;
3163 }
3164 }
3165
3166 /*
3167 * Here we must make sure that no processes are submitting requests
3168 * to target drivers i.e. no one may be executing
3169 * __split_and_process_bio. This is called from dm_request and
3170 * dm_wq_work.
3171 *
3172 * To get all processes out of __split_and_process_bio in dm_request,
3173 * we take the write lock. To prevent any process from reentering
3174 * __split_and_process_bio from dm_request and quiesce the thread
3175 * (dm_wq_work), we set BMF_BLOCK_IO_FOR_SUSPEND and call
3176 * flush_workqueue(md->wq).
3177 */
3178 set_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags);
3179 if (map)
3180 synchronize_srcu(&md->io_barrier);
3181
3182 /*
3183 * Stop md->queue before flushing md->wq in case request-based
3184 * dm defers requests to md->wq from md->queue.
3185 */
3186 if (dm_request_based(md)) {
3187 dm_stop_queue(md->queue);
3188 if (md->kworker_task)
3189 flush_kthread_worker(&md->kworker);
3190 }
3191
3192 flush_workqueue(md->wq);
3193
3194 /*
3195 * At this point no more requests are entering target request routines.
3196 * We call dm_wait_for_completion to wait for all existing requests
3197 * to finish.
3198 */
3199 r = dm_wait_for_completion(md, interruptible);
3200
3201 if (noflush)
3202 clear_bit(DMF_NOFLUSH_SUSPENDING, &md->flags);
3203 if (map)
3204 synchronize_srcu(&md->io_barrier);
3205
3206 /* were we interrupted ? */
3207 if (r < 0) {
3208 dm_queue_flush(md);
3209
3210 if (dm_request_based(md))
3211 dm_start_queue(md->queue);
3212
3213 unlock_fs(md);
3214 dm_table_presuspend_undo_targets(map);
3215 /* pushback list is already flushed, so skip flush */
3216 }
3217
3218 return r;
3219}
3220
3221/*
3222 * We need to be able to change a mapping table under a mounted
3223 * filesystem. For example we might want to move some data in
3224 * the background. Before the table can be swapped with
3225 * dm_bind_table, dm_suspend must be called to flush any in
3226 * flight bios and ensure that any further io gets deferred.
3227 */
3228/*
3229 * Suspend mechanism in request-based dm.
3230 *
3231 * 1. Flush all I/Os by lock_fs() if needed.
3232 * 2. Stop dispatching any I/O by stopping the request_queue.
3233 * 3. Wait for all in-flight I/Os to be completed or requeued.
3234 *
3235 * To abort suspend, start the request_queue.
3236 */
3237int dm_suspend(struct mapped_device *md, unsigned suspend_flags)
3238{
3239 struct dm_table *map = NULL;
3240 int r = 0;
3241
3242retry:
3243 mutex_lock_nested(&md->suspend_lock, SINGLE_DEPTH_NESTING);
3244
3245 if (dm_suspended_md(md)) {
3246 r = -EINVAL;
3247 goto out_unlock;
3248 }
3249
3250 if (dm_suspended_internally_md(md)) {
3251 /* already internally suspended, wait for internal resume */
3252 mutex_unlock(&md->suspend_lock);
3253 r = wait_on_bit(&md->flags, DMF_SUSPENDED_INTERNALLY, TASK_INTERRUPTIBLE);
3254 if (r)
3255 return r;
3256 goto retry;
3257 }
3258
3259 map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock));
3260
3261 r = __dm_suspend(md, map, suspend_flags, TASK_INTERRUPTIBLE);
3262 if (r)
3263 goto out_unlock;
3264
3265 set_bit(DMF_SUSPENDED, &md->flags);
3266
3267 dm_table_postsuspend_targets(map);
3268
3269out_unlock:
3270 mutex_unlock(&md->suspend_lock);
3271 return r;
3272}
3273
3274static int __dm_resume(struct mapped_device *md, struct dm_table *map)
3275{
3276 if (map) {
3277 int r = dm_table_resume_targets(map);
3278 if (r)
3279 return r;
3280 }
3281
3282 dm_queue_flush(md);
3283
3284 /*
3285 * Flushing deferred I/Os must be done after targets are resumed
3286 * so that mapping of targets can work correctly.
3287 * Request-based dm is queueing the deferred I/Os in its request_queue.
3288 */
3289 if (dm_request_based(md))
3290 dm_start_queue(md->queue);
3291
3292 unlock_fs(md);
3293
3294 return 0;
3295}
3296
3297int dm_resume(struct mapped_device *md)
3298{
3299 int r = -EINVAL;
3300 struct dm_table *map = NULL;
3301
3302retry:
3303 mutex_lock_nested(&md->suspend_lock, SINGLE_DEPTH_NESTING);
3304
3305 if (!dm_suspended_md(md))
3306 goto out;
3307
3308 if (dm_suspended_internally_md(md)) {
3309 /* already internally suspended, wait for internal resume */
3310 mutex_unlock(&md->suspend_lock);
3311 r = wait_on_bit(&md->flags, DMF_SUSPENDED_INTERNALLY, TASK_INTERRUPTIBLE);
3312 if (r)
3313 return r;
3314 goto retry;
3315 }
3316
3317 map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock));
3318 if (!map || !dm_table_get_size(map))
3319 goto out;
3320
3321 r = __dm_resume(md, map);
3322 if (r)
3323 goto out;
3324
3325 clear_bit(DMF_SUSPENDED, &md->flags);
3326
3327 r = 0;
3328out:
3329 mutex_unlock(&md->suspend_lock);
3330
3331 return r;
3332}
3333
3334/*
3335 * Internal suspend/resume works like userspace-driven suspend. It waits
3336 * until all bios finish and prevents issuing new bios to the target drivers.
3337 * It may be used only from the kernel.
3338 */
3339
3340static void __dm_internal_suspend(struct mapped_device *md, unsigned suspend_flags)
3341{
3342 struct dm_table *map = NULL;
3343
3344 if (md->internal_suspend_count++)
3345 return; /* nested internal suspend */
3346
3347 if (dm_suspended_md(md)) {
3348 set_bit(DMF_SUSPENDED_INTERNALLY, &md->flags);
3349 return; /* nest suspend */
3350 }
3351
3352 map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock));
3353
3354 /*
3355 * Using TASK_UNINTERRUPTIBLE because only NOFLUSH internal suspend is
3356 * supported. Properly supporting a TASK_INTERRUPTIBLE internal suspend
3357 * would require changing .presuspend to return an error -- avoid this
3358 * until there is a need for more elaborate variants of internal suspend.
3359 */
3360 (void) __dm_suspend(md, map, suspend_flags, TASK_UNINTERRUPTIBLE);
3361
3362 set_bit(DMF_SUSPENDED_INTERNALLY, &md->flags);
3363
3364 dm_table_postsuspend_targets(map);
3365}
3366
3367static void __dm_internal_resume(struct mapped_device *md)
3368{
3369 BUG_ON(!md->internal_suspend_count);
3370
3371 if (--md->internal_suspend_count)
3372 return; /* resume from nested internal suspend */
3373
3374 if (dm_suspended_md(md))
3375 goto done; /* resume from nested suspend */
3376
3377 /*
3378 * NOTE: existing callers don't need to call dm_table_resume_targets
3379 * (which may fail -- so best to avoid it for now by passing NULL map)
3380 */
3381 (void) __dm_resume(md, NULL);
3382
3383done:
3384 clear_bit(DMF_SUSPENDED_INTERNALLY, &md->flags);
3385 smp_mb__after_atomic();
3386 wake_up_bit(&md->flags, DMF_SUSPENDED_INTERNALLY);
3387}
3388
3389void dm_internal_suspend_noflush(struct mapped_device *md)
3390{
3391 mutex_lock(&md->suspend_lock);
3392 __dm_internal_suspend(md, DM_SUSPEND_NOFLUSH_FLAG);
3393 mutex_unlock(&md->suspend_lock);
3394}
3395EXPORT_SYMBOL_GPL(dm_internal_suspend_noflush);
3396
3397void dm_internal_resume(struct mapped_device *md)
3398{
3399 mutex_lock(&md->suspend_lock);
3400 __dm_internal_resume(md);
3401 mutex_unlock(&md->suspend_lock);
3402}
3403EXPORT_SYMBOL_GPL(dm_internal_resume);
3404
3405/*
3406 * Fast variants of internal suspend/resume hold md->suspend_lock,
3407 * which prevents interaction with userspace-driven suspend.
3408 */
3409
3410void dm_internal_suspend_fast(struct mapped_device *md)
3411{
3412 mutex_lock(&md->suspend_lock);
3413 if (dm_suspended_md(md) || dm_suspended_internally_md(md))
3414 return;
3415
3416 set_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags);
3417 synchronize_srcu(&md->io_barrier);
3418 flush_workqueue(md->wq);
3419 dm_wait_for_completion(md, TASK_UNINTERRUPTIBLE);
3420}
3421EXPORT_SYMBOL_GPL(dm_internal_suspend_fast);
3422
3423void dm_internal_resume_fast(struct mapped_device *md)
3424{
3425 if (dm_suspended_md(md) || dm_suspended_internally_md(md))
3426 goto done;
3427
3428 dm_queue_flush(md);
3429
3430done:
3431 mutex_unlock(&md->suspend_lock);
3432}
3433EXPORT_SYMBOL_GPL(dm_internal_resume_fast);
3434
3435/*-----------------------------------------------------------------
3436 * Event notification.
3437 *---------------------------------------------------------------*/
3438int dm_kobject_uevent(struct mapped_device *md, enum kobject_action action,
3439 unsigned cookie)
3440{
3441 char udev_cookie[DM_COOKIE_LENGTH];
3442 char *envp[] = { udev_cookie, NULL };
3443
3444 if (!cookie)
3445 return kobject_uevent(&disk_to_dev(md->disk)->kobj, action);
3446 else {
3447 snprintf(udev_cookie, DM_COOKIE_LENGTH, "%s=%u",
3448 DM_COOKIE_ENV_VAR_NAME, cookie);
3449 return kobject_uevent_env(&disk_to_dev(md->disk)->kobj,
3450 action, envp);
3451 }
3452}
3453
3454uint32_t dm_next_uevent_seq(struct mapped_device *md)
3455{
3456 return atomic_add_return(1, &md->uevent_seq);
3457}
3458
3459uint32_t dm_get_event_nr(struct mapped_device *md)
3460{
3461 return atomic_read(&md->event_nr);
3462}
3463
3464int dm_wait_event(struct mapped_device *md, int event_nr)
3465{
3466 return wait_event_interruptible(md->eventq,
3467 (event_nr != atomic_read(&md->event_nr)));
3468}
3469
3470void dm_uevent_add(struct mapped_device *md, struct list_head *elist)
3471{
3472 unsigned long flags;
3473
3474 spin_lock_irqsave(&md->uevent_lock, flags);
3475 list_add(elist, &md->uevent_list);
3476 spin_unlock_irqrestore(&md->uevent_lock, flags);
3477}
3478
3479/*
3480 * The gendisk is only valid as long as you have a reference
3481 * count on 'md'.
3482 */
3483struct gendisk *dm_disk(struct mapped_device *md)
3484{
3485 return md->disk;
3486}
3487EXPORT_SYMBOL_GPL(dm_disk);
3488
3489struct kobject *dm_kobject(struct mapped_device *md)
3490{
3491 return &md->kobj_holder.kobj;
3492}
3493
3494struct mapped_device *dm_get_from_kobject(struct kobject *kobj)
3495{
3496 struct mapped_device *md;
3497
3498 md = container_of(kobj, struct mapped_device, kobj_holder.kobj);
3499
3500 if (test_bit(DMF_FREEING, &md->flags) ||
3501 dm_deleting_md(md))
3502 return NULL;
3503
3504 dm_get(md);
3505 return md;
3506}
3507
3508int dm_suspended_md(struct mapped_device *md)
3509{
3510 return test_bit(DMF_SUSPENDED, &md->flags);
3511}
3512
3513int dm_suspended_internally_md(struct mapped_device *md)
3514{
3515 return test_bit(DMF_SUSPENDED_INTERNALLY, &md->flags);
3516}
3517
3518int dm_test_deferred_remove_flag(struct mapped_device *md)
3519{
3520 return test_bit(DMF_DEFERRED_REMOVE, &md->flags);
3521}
3522
3523int dm_suspended(struct dm_target *ti)
3524{
3525 return dm_suspended_md(dm_table_get_md(ti->table));
3526}
3527EXPORT_SYMBOL_GPL(dm_suspended);
3528
3529int dm_noflush_suspending(struct dm_target *ti)
3530{
3531 return __noflush_suspending(dm_table_get_md(ti->table));
3532}
3533EXPORT_SYMBOL_GPL(dm_noflush_suspending);
3534
3535struct dm_md_mempools *dm_alloc_md_mempools(struct mapped_device *md, unsigned type,
3536 unsigned integrity, unsigned per_io_data_size)
3537{
3538 struct dm_md_mempools *pools = kzalloc_node(sizeof(*pools), GFP_KERNEL, md->numa_node_id);
3539 struct kmem_cache *cachep = NULL;
3540 unsigned int pool_size = 0;
3541 unsigned int front_pad;
3542
3543 if (!pools)
3544 return NULL;
3545
3546 type = filter_md_type(type, md);
3547
3548 switch (type) {
3549 case DM_TYPE_BIO_BASED:
3550 cachep = _io_cache;
3551 pool_size = dm_get_reserved_bio_based_ios();
3552 front_pad = roundup(per_io_data_size, __alignof__(struct dm_target_io)) + offsetof(struct dm_target_io, clone);
3553 break;
3554 case DM_TYPE_REQUEST_BASED:
3555 cachep = _rq_tio_cache;
3556 pool_size = dm_get_reserved_rq_based_ios();
3557 pools->rq_pool = mempool_create_slab_pool(pool_size, _rq_cache);
3558 if (!pools->rq_pool)
3559 goto out;
3560 /* fall through to setup remaining rq-based pools */
3561 case DM_TYPE_MQ_REQUEST_BASED:
3562 if (!pool_size)
3563 pool_size = dm_get_reserved_rq_based_ios();
3564 front_pad = offsetof(struct dm_rq_clone_bio_info, clone);
3565 /* per_io_data_size is used for blk-mq pdu at queue allocation */
3566 break;
3567 default:
3568 BUG();
3569 }
3570
3571 if (cachep) {
3572 pools->io_pool = mempool_create_slab_pool(pool_size, cachep);
3573 if (!pools->io_pool)
3574 goto out;
3575 }
3576
3577 pools->bs = bioset_create_nobvec(pool_size, front_pad);
3578 if (!pools->bs)
3579 goto out;
3580
3581 if (integrity && bioset_integrity_create(pools->bs, pool_size))
3582 goto out;
3583
3584 return pools;
3585
3586out:
3587 dm_free_md_mempools(pools);
3588
3589 return NULL;
3590}
3591
3592void dm_free_md_mempools(struct dm_md_mempools *pools)
3593{
3594 if (!pools)
3595 return;
3596
3597 mempool_destroy(pools->io_pool);
3598 mempool_destroy(pools->rq_pool);
3599
3600 if (pools->bs)
3601 bioset_free(pools->bs);
3602
3603 kfree(pools);
3604}
3605
3606static int dm_pr_register(struct block_device *bdev, u64 old_key, u64 new_key,
3607 u32 flags)
3608{
3609 struct mapped_device *md = bdev->bd_disk->private_data;
3610 const struct pr_ops *ops;
3611 fmode_t mode;
3612 int r;
3613
3614 r = dm_grab_bdev_for_ioctl(md, &bdev, &mode);
3615 if (r < 0)
3616 return r;
3617
3618 ops = bdev->bd_disk->fops->pr_ops;
3619 if (ops && ops->pr_register)
3620 r = ops->pr_register(bdev, old_key, new_key, flags);
3621 else
3622 r = -EOPNOTSUPP;
3623
3624 bdput(bdev);
3625 return r;
3626}
3627
3628static int dm_pr_reserve(struct block_device *bdev, u64 key, enum pr_type type,
3629 u32 flags)
3630{
3631 struct mapped_device *md = bdev->bd_disk->private_data;
3632 const struct pr_ops *ops;
3633 fmode_t mode;
3634 int r;
3635
3636 r = dm_grab_bdev_for_ioctl(md, &bdev, &mode);
3637 if (r < 0)
3638 return r;
3639
3640 ops = bdev->bd_disk->fops->pr_ops;
3641 if (ops && ops->pr_reserve)
3642 r = ops->pr_reserve(bdev, key, type, flags);
3643 else
3644 r = -EOPNOTSUPP;
3645
3646 bdput(bdev);
3647 return r;
3648}
3649
3650static int dm_pr_release(struct block_device *bdev, u64 key, enum pr_type type)
3651{
3652 struct mapped_device *md = bdev->bd_disk->private_data;
3653 const struct pr_ops *ops;
3654 fmode_t mode;
3655 int r;
3656
3657 r = dm_grab_bdev_for_ioctl(md, &bdev, &mode);
3658 if (r < 0)
3659 return r;
3660
3661 ops = bdev->bd_disk->fops->pr_ops;
3662 if (ops && ops->pr_release)
3663 r = ops->pr_release(bdev, key, type);
3664 else
3665 r = -EOPNOTSUPP;
3666
3667 bdput(bdev);
3668 return r;
3669}
3670
3671static int dm_pr_preempt(struct block_device *bdev, u64 old_key, u64 new_key,
3672 enum pr_type type, bool abort)
3673{
3674 struct mapped_device *md = bdev->bd_disk->private_data;
3675 const struct pr_ops *ops;
3676 fmode_t mode;
3677 int r;
3678
3679 r = dm_grab_bdev_for_ioctl(md, &bdev, &mode);
3680 if (r < 0)
3681 return r;
3682
3683 ops = bdev->bd_disk->fops->pr_ops;
3684 if (ops && ops->pr_preempt)
3685 r = ops->pr_preempt(bdev, old_key, new_key, type, abort);
3686 else
3687 r = -EOPNOTSUPP;
3688
3689 bdput(bdev);
3690 return r;
3691}
3692
3693static int dm_pr_clear(struct block_device *bdev, u64 key)
3694{
3695 struct mapped_device *md = bdev->bd_disk->private_data;
3696 const struct pr_ops *ops;
3697 fmode_t mode;
3698 int r;
3699
3700 r = dm_grab_bdev_for_ioctl(md, &bdev, &mode);
3701 if (r < 0)
3702 return r;
3703
3704 ops = bdev->bd_disk->fops->pr_ops;
3705 if (ops && ops->pr_clear)
3706 r = ops->pr_clear(bdev, key);
3707 else
3708 r = -EOPNOTSUPP;
3709
3710 bdput(bdev);
3711 return r;
3712}
3713
3714static const struct pr_ops dm_pr_ops = {
3715 .pr_register = dm_pr_register,
3716 .pr_reserve = dm_pr_reserve,
3717 .pr_release = dm_pr_release,
3718 .pr_preempt = dm_pr_preempt,
3719 .pr_clear = dm_pr_clear,
3720};
3721
3722static const struct block_device_operations dm_blk_dops = {
3723 .open = dm_blk_open,
3724 .release = dm_blk_close,
3725 .ioctl = dm_blk_ioctl,
3726 .getgeo = dm_blk_getgeo,
3727 .pr_ops = &dm_pr_ops,
3728 .owner = THIS_MODULE
3729};
3730
3731/*
3732 * module hooks
3733 */
3734module_init(dm_init);
3735module_exit(dm_exit);
3736
3737module_param(major, uint, 0);
3738MODULE_PARM_DESC(major, "The major number of the device mapper");
3739
3740module_param(reserved_bio_based_ios, uint, S_IRUGO | S_IWUSR);
3741MODULE_PARM_DESC(reserved_bio_based_ios, "Reserved IOs in bio-based mempools");
3742
3743module_param(reserved_rq_based_ios, uint, S_IRUGO | S_IWUSR);
3744MODULE_PARM_DESC(reserved_rq_based_ios, "Reserved IOs in request-based mempools");
3745
3746module_param(use_blk_mq, bool, S_IRUGO | S_IWUSR);
3747MODULE_PARM_DESC(use_blk_mq, "Use block multiqueue for request-based DM devices");
3748
3749module_param(dm_mq_nr_hw_queues, uint, S_IRUGO | S_IWUSR);
3750MODULE_PARM_DESC(dm_mq_nr_hw_queues, "Number of hardware queues for request-based dm-mq devices");
3751
3752module_param(dm_mq_queue_depth, uint, S_IRUGO | S_IWUSR);
3753MODULE_PARM_DESC(dm_mq_queue_depth, "Queue depth for request-based dm-mq devices");
3754
3755module_param(dm_numa_node, int, S_IRUGO | S_IWUSR);
3756MODULE_PARM_DESC(dm_numa_node, "NUMA node for DM device memory allocations");
3757
3758MODULE_DESCRIPTION(DM_NAME " driver");
3759MODULE_AUTHOR("Joe Thornber <dm-devel@redhat.com>");
3760MODULE_LICENSE("GPL");
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2001, 2002 Sistina Software (UK) Limited.
4 * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
5 *
6 * This file is released under the GPL.
7 */
8
9#include "dm-core.h"
10#include "dm-rq.h"
11#include "dm-uevent.h"
12#include "dm-ima.h"
13
14#include <linux/bio-integrity.h>
15#include <linux/init.h>
16#include <linux/module.h>
17#include <linux/mutex.h>
18#include <linux/sched/mm.h>
19#include <linux/sched/signal.h>
20#include <linux/blkpg.h>
21#include <linux/bio.h>
22#include <linux/mempool.h>
23#include <linux/dax.h>
24#include <linux/slab.h>
25#include <linux/idr.h>
26#include <linux/uio.h>
27#include <linux/hdreg.h>
28#include <linux/delay.h>
29#include <linux/wait.h>
30#include <linux/pr.h>
31#include <linux/refcount.h>
32#include <linux/part_stat.h>
33#include <linux/blk-crypto.h>
34#include <linux/blk-crypto-profile.h>
35
36#define DM_MSG_PREFIX "core"
37
38/*
39 * Cookies are numeric values sent with CHANGE and REMOVE
40 * uevents while resuming, removing or renaming the device.
41 */
42#define DM_COOKIE_ENV_VAR_NAME "DM_COOKIE"
43#define DM_COOKIE_LENGTH 24
44
45/*
46 * For REQ_POLLED fs bio, this flag is set if we link mapped underlying
47 * dm_io into one list, and reuse bio->bi_private as the list head. Before
48 * ending this fs bio, we will recover its ->bi_private.
49 */
50#define REQ_DM_POLL_LIST REQ_DRV
51
52static const char *_name = DM_NAME;
53
54static unsigned int major;
55static unsigned int _major;
56
57static DEFINE_IDR(_minor_idr);
58
59static DEFINE_SPINLOCK(_minor_lock);
60
61static void do_deferred_remove(struct work_struct *w);
62
63static DECLARE_WORK(deferred_remove_work, do_deferred_remove);
64
65static struct workqueue_struct *deferred_remove_workqueue;
66
67atomic_t dm_global_event_nr = ATOMIC_INIT(0);
68DECLARE_WAIT_QUEUE_HEAD(dm_global_eventq);
69
70void dm_issue_global_event(void)
71{
72 atomic_inc(&dm_global_event_nr);
73 wake_up(&dm_global_eventq);
74}
75
76DEFINE_STATIC_KEY_FALSE(stats_enabled);
77DEFINE_STATIC_KEY_FALSE(swap_bios_enabled);
78DEFINE_STATIC_KEY_FALSE(zoned_enabled);
79
80/*
81 * One of these is allocated (on-stack) per original bio.
82 */
83struct clone_info {
84 struct dm_table *map;
85 struct bio *bio;
86 struct dm_io *io;
87 sector_t sector;
88 unsigned int sector_count;
89 bool is_abnormal_io:1;
90 bool submit_as_polled:1;
91};
92
93static inline struct dm_target_io *clone_to_tio(struct bio *clone)
94{
95 return container_of(clone, struct dm_target_io, clone);
96}
97
98void *dm_per_bio_data(struct bio *bio, size_t data_size)
99{
100 if (!dm_tio_flagged(clone_to_tio(bio), DM_TIO_INSIDE_DM_IO))
101 return (char *)bio - DM_TARGET_IO_BIO_OFFSET - data_size;
102 return (char *)bio - DM_IO_BIO_OFFSET - data_size;
103}
104EXPORT_SYMBOL_GPL(dm_per_bio_data);
105
106struct bio *dm_bio_from_per_bio_data(void *data, size_t data_size)
107{
108 struct dm_io *io = (struct dm_io *)((char *)data + data_size);
109
110 if (io->magic == DM_IO_MAGIC)
111 return (struct bio *)((char *)io + DM_IO_BIO_OFFSET);
112 BUG_ON(io->magic != DM_TIO_MAGIC);
113 return (struct bio *)((char *)io + DM_TARGET_IO_BIO_OFFSET);
114}
115EXPORT_SYMBOL_GPL(dm_bio_from_per_bio_data);
116
117unsigned int dm_bio_get_target_bio_nr(const struct bio *bio)
118{
119 return container_of(bio, struct dm_target_io, clone)->target_bio_nr;
120}
121EXPORT_SYMBOL_GPL(dm_bio_get_target_bio_nr);
122
123#define MINOR_ALLOCED ((void *)-1)
124
125#define DM_NUMA_NODE NUMA_NO_NODE
126static int dm_numa_node = DM_NUMA_NODE;
127
128#define DEFAULT_SWAP_BIOS (8 * 1048576 / PAGE_SIZE)
129static int swap_bios = DEFAULT_SWAP_BIOS;
130static int get_swap_bios(void)
131{
132 int latch = READ_ONCE(swap_bios);
133
134 if (unlikely(latch <= 0))
135 latch = DEFAULT_SWAP_BIOS;
136 return latch;
137}
138
139struct table_device {
140 struct list_head list;
141 refcount_t count;
142 struct dm_dev dm_dev;
143};
144
145/*
146 * Bio-based DM's mempools' reserved IOs set by the user.
147 */
148#define RESERVED_BIO_BASED_IOS 16
149static unsigned int reserved_bio_based_ios = RESERVED_BIO_BASED_IOS;
150
151static int __dm_get_module_param_int(int *module_param, int min, int max)
152{
153 int param = READ_ONCE(*module_param);
154 int modified_param = 0;
155 bool modified = true;
156
157 if (param < min)
158 modified_param = min;
159 else if (param > max)
160 modified_param = max;
161 else
162 modified = false;
163
164 if (modified) {
165 (void)cmpxchg(module_param, param, modified_param);
166 param = modified_param;
167 }
168
169 return param;
170}
171
172unsigned int __dm_get_module_param(unsigned int *module_param, unsigned int def, unsigned int max)
173{
174 unsigned int param = READ_ONCE(*module_param);
175 unsigned int modified_param = 0;
176
177 if (!param)
178 modified_param = def;
179 else if (param > max)
180 modified_param = max;
181
182 if (modified_param) {
183 (void)cmpxchg(module_param, param, modified_param);
184 param = modified_param;
185 }
186
187 return param;
188}
189
190unsigned int dm_get_reserved_bio_based_ios(void)
191{
192 return __dm_get_module_param(&reserved_bio_based_ios,
193 RESERVED_BIO_BASED_IOS, DM_RESERVED_MAX_IOS);
194}
195EXPORT_SYMBOL_GPL(dm_get_reserved_bio_based_ios);
196
197static unsigned int dm_get_numa_node(void)
198{
199 return __dm_get_module_param_int(&dm_numa_node,
200 DM_NUMA_NODE, num_online_nodes() - 1);
201}
202
203static int __init local_init(void)
204{
205 int r;
206
207 r = dm_uevent_init();
208 if (r)
209 return r;
210
211 deferred_remove_workqueue = alloc_ordered_workqueue("kdmremove", 0);
212 if (!deferred_remove_workqueue) {
213 r = -ENOMEM;
214 goto out_uevent_exit;
215 }
216
217 _major = major;
218 r = register_blkdev(_major, _name);
219 if (r < 0)
220 goto out_free_workqueue;
221
222 if (!_major)
223 _major = r;
224
225 return 0;
226
227out_free_workqueue:
228 destroy_workqueue(deferred_remove_workqueue);
229out_uevent_exit:
230 dm_uevent_exit();
231
232 return r;
233}
234
235static void local_exit(void)
236{
237 destroy_workqueue(deferred_remove_workqueue);
238
239 unregister_blkdev(_major, _name);
240 dm_uevent_exit();
241
242 _major = 0;
243
244 DMINFO("cleaned up");
245}
246
247static int (*_inits[])(void) __initdata = {
248 local_init,
249 dm_target_init,
250 dm_linear_init,
251 dm_stripe_init,
252 dm_io_init,
253 dm_kcopyd_init,
254 dm_interface_init,
255 dm_statistics_init,
256};
257
258static void (*_exits[])(void) = {
259 local_exit,
260 dm_target_exit,
261 dm_linear_exit,
262 dm_stripe_exit,
263 dm_io_exit,
264 dm_kcopyd_exit,
265 dm_interface_exit,
266 dm_statistics_exit,
267};
268
269static int __init dm_init(void)
270{
271 const int count = ARRAY_SIZE(_inits);
272 int r, i;
273
274#if (IS_ENABLED(CONFIG_IMA) && !IS_ENABLED(CONFIG_IMA_DISABLE_HTABLE))
275 DMWARN("CONFIG_IMA_DISABLE_HTABLE is disabled."
276 " Duplicate IMA measurements will not be recorded in the IMA log.");
277#endif
278
279 for (i = 0; i < count; i++) {
280 r = _inits[i]();
281 if (r)
282 goto bad;
283 }
284
285 return 0;
286bad:
287 while (i--)
288 _exits[i]();
289
290 return r;
291}
292
293static void __exit dm_exit(void)
294{
295 int i = ARRAY_SIZE(_exits);
296
297 while (i--)
298 _exits[i]();
299
300 /*
301 * Should be empty by this point.
302 */
303 idr_destroy(&_minor_idr);
304}
305
306/*
307 * Block device functions
308 */
309int dm_deleting_md(struct mapped_device *md)
310{
311 return test_bit(DMF_DELETING, &md->flags);
312}
313
314static int dm_blk_open(struct gendisk *disk, blk_mode_t mode)
315{
316 struct mapped_device *md;
317
318 spin_lock(&_minor_lock);
319
320 md = disk->private_data;
321 if (!md)
322 goto out;
323
324 if (test_bit(DMF_FREEING, &md->flags) ||
325 dm_deleting_md(md)) {
326 md = NULL;
327 goto out;
328 }
329
330 dm_get(md);
331 atomic_inc(&md->open_count);
332out:
333 spin_unlock(&_minor_lock);
334
335 return md ? 0 : -ENXIO;
336}
337
338static void dm_blk_close(struct gendisk *disk)
339{
340 struct mapped_device *md;
341
342 spin_lock(&_minor_lock);
343
344 md = disk->private_data;
345 if (WARN_ON(!md))
346 goto out;
347
348 if (atomic_dec_and_test(&md->open_count) &&
349 (test_bit(DMF_DEFERRED_REMOVE, &md->flags)))
350 queue_work(deferred_remove_workqueue, &deferred_remove_work);
351
352 dm_put(md);
353out:
354 spin_unlock(&_minor_lock);
355}
356
357int dm_open_count(struct mapped_device *md)
358{
359 return atomic_read(&md->open_count);
360}
361
362/*
363 * Guarantees nothing is using the device before it's deleted.
364 */
365int dm_lock_for_deletion(struct mapped_device *md, bool mark_deferred, bool only_deferred)
366{
367 int r = 0;
368
369 spin_lock(&_minor_lock);
370
371 if (dm_open_count(md)) {
372 r = -EBUSY;
373 if (mark_deferred)
374 set_bit(DMF_DEFERRED_REMOVE, &md->flags);
375 } else if (only_deferred && !test_bit(DMF_DEFERRED_REMOVE, &md->flags))
376 r = -EEXIST;
377 else
378 set_bit(DMF_DELETING, &md->flags);
379
380 spin_unlock(&_minor_lock);
381
382 return r;
383}
384
385int dm_cancel_deferred_remove(struct mapped_device *md)
386{
387 int r = 0;
388
389 spin_lock(&_minor_lock);
390
391 if (test_bit(DMF_DELETING, &md->flags))
392 r = -EBUSY;
393 else
394 clear_bit(DMF_DEFERRED_REMOVE, &md->flags);
395
396 spin_unlock(&_minor_lock);
397
398 return r;
399}
400
401static void do_deferred_remove(struct work_struct *w)
402{
403 dm_deferred_remove();
404}
405
406static int dm_blk_getgeo(struct block_device *bdev, struct hd_geometry *geo)
407{
408 struct mapped_device *md = bdev->bd_disk->private_data;
409
410 return dm_get_geometry(md, geo);
411}
412
413static int dm_prepare_ioctl(struct mapped_device *md, int *srcu_idx,
414 struct block_device **bdev)
415{
416 struct dm_target *ti;
417 struct dm_table *map;
418 int r;
419
420retry:
421 r = -ENOTTY;
422 map = dm_get_live_table(md, srcu_idx);
423 if (!map || !dm_table_get_size(map))
424 return r;
425
426 /* We only support devices that have a single target */
427 if (map->num_targets != 1)
428 return r;
429
430 ti = dm_table_get_target(map, 0);
431 if (!ti->type->prepare_ioctl)
432 return r;
433
434 if (dm_suspended_md(md))
435 return -EAGAIN;
436
437 r = ti->type->prepare_ioctl(ti, bdev);
438 if (r == -ENOTCONN && !fatal_signal_pending(current)) {
439 dm_put_live_table(md, *srcu_idx);
440 fsleep(10000);
441 goto retry;
442 }
443
444 return r;
445}
446
447static void dm_unprepare_ioctl(struct mapped_device *md, int srcu_idx)
448{
449 dm_put_live_table(md, srcu_idx);
450}
451
452static int dm_blk_ioctl(struct block_device *bdev, blk_mode_t mode,
453 unsigned int cmd, unsigned long arg)
454{
455 struct mapped_device *md = bdev->bd_disk->private_data;
456 int r, srcu_idx;
457
458 r = dm_prepare_ioctl(md, &srcu_idx, &bdev);
459 if (r < 0)
460 goto out;
461
462 if (r > 0) {
463 /*
464 * Target determined this ioctl is being issued against a
465 * subset of the parent bdev; require extra privileges.
466 */
467 if (!capable(CAP_SYS_RAWIO)) {
468 DMDEBUG_LIMIT(
469 "%s: sending ioctl %x to DM device without required privilege.",
470 current->comm, cmd);
471 r = -ENOIOCTLCMD;
472 goto out;
473 }
474 }
475
476 if (!bdev->bd_disk->fops->ioctl)
477 r = -ENOTTY;
478 else
479 r = bdev->bd_disk->fops->ioctl(bdev, mode, cmd, arg);
480out:
481 dm_unprepare_ioctl(md, srcu_idx);
482 return r;
483}
484
485u64 dm_start_time_ns_from_clone(struct bio *bio)
486{
487 return jiffies_to_nsecs(clone_to_tio(bio)->io->start_time);
488}
489EXPORT_SYMBOL_GPL(dm_start_time_ns_from_clone);
490
491static inline bool bio_is_flush_with_data(struct bio *bio)
492{
493 return ((bio->bi_opf & REQ_PREFLUSH) && bio->bi_iter.bi_size);
494}
495
496static inline unsigned int dm_io_sectors(struct dm_io *io, struct bio *bio)
497{
498 /*
499 * If REQ_PREFLUSH set, don't account payload, it will be
500 * submitted (and accounted) after this flush completes.
501 */
502 if (bio_is_flush_with_data(bio))
503 return 0;
504 if (unlikely(dm_io_flagged(io, DM_IO_WAS_SPLIT)))
505 return io->sectors;
506 return bio_sectors(bio);
507}
508
509static void dm_io_acct(struct dm_io *io, bool end)
510{
511 struct bio *bio = io->orig_bio;
512
513 if (dm_io_flagged(io, DM_IO_BLK_STAT)) {
514 if (!end)
515 bdev_start_io_acct(bio->bi_bdev, bio_op(bio),
516 io->start_time);
517 else
518 bdev_end_io_acct(bio->bi_bdev, bio_op(bio),
519 dm_io_sectors(io, bio),
520 io->start_time);
521 }
522
523 if (static_branch_unlikely(&stats_enabled) &&
524 unlikely(dm_stats_used(&io->md->stats))) {
525 sector_t sector;
526
527 if (unlikely(dm_io_flagged(io, DM_IO_WAS_SPLIT)))
528 sector = bio_end_sector(bio) - io->sector_offset;
529 else
530 sector = bio->bi_iter.bi_sector;
531
532 dm_stats_account_io(&io->md->stats, bio_data_dir(bio),
533 sector, dm_io_sectors(io, bio),
534 end, io->start_time, &io->stats_aux);
535 }
536}
537
538static void __dm_start_io_acct(struct dm_io *io)
539{
540 dm_io_acct(io, false);
541}
542
543static void dm_start_io_acct(struct dm_io *io, struct bio *clone)
544{
545 /*
546 * Ensure IO accounting is only ever started once.
547 */
548 if (dm_io_flagged(io, DM_IO_ACCOUNTED))
549 return;
550
551 /* Expect no possibility for race unless DM_TIO_IS_DUPLICATE_BIO. */
552 if (!clone || likely(dm_tio_is_normal(clone_to_tio(clone)))) {
553 dm_io_set_flag(io, DM_IO_ACCOUNTED);
554 } else {
555 unsigned long flags;
556 /* Can afford locking given DM_TIO_IS_DUPLICATE_BIO */
557 spin_lock_irqsave(&io->lock, flags);
558 if (dm_io_flagged(io, DM_IO_ACCOUNTED)) {
559 spin_unlock_irqrestore(&io->lock, flags);
560 return;
561 }
562 dm_io_set_flag(io, DM_IO_ACCOUNTED);
563 spin_unlock_irqrestore(&io->lock, flags);
564 }
565
566 __dm_start_io_acct(io);
567}
568
569static void dm_end_io_acct(struct dm_io *io)
570{
571 dm_io_acct(io, true);
572}
573
574static struct dm_io *alloc_io(struct mapped_device *md, struct bio *bio, gfp_t gfp_mask)
575{
576 struct dm_io *io;
577 struct dm_target_io *tio;
578 struct bio *clone;
579
580 clone = bio_alloc_clone(NULL, bio, gfp_mask, &md->mempools->io_bs);
581 if (unlikely(!clone))
582 return NULL;
583 tio = clone_to_tio(clone);
584 tio->flags = 0;
585 dm_tio_set_flag(tio, DM_TIO_INSIDE_DM_IO);
586 tio->io = NULL;
587
588 io = container_of(tio, struct dm_io, tio);
589 io->magic = DM_IO_MAGIC;
590 io->status = BLK_STS_OK;
591
592 /* one ref is for submission, the other is for completion */
593 atomic_set(&io->io_count, 2);
594 this_cpu_inc(*md->pending_io);
595 io->orig_bio = bio;
596 io->md = md;
597 spin_lock_init(&io->lock);
598 io->start_time = jiffies;
599 io->flags = 0;
600 if (blk_queue_io_stat(md->queue))
601 dm_io_set_flag(io, DM_IO_BLK_STAT);
602
603 if (static_branch_unlikely(&stats_enabled) &&
604 unlikely(dm_stats_used(&md->stats)))
605 dm_stats_record_start(&md->stats, &io->stats_aux);
606
607 return io;
608}
609
610static void free_io(struct dm_io *io)
611{
612 bio_put(&io->tio.clone);
613}
614
615static struct bio *alloc_tio(struct clone_info *ci, struct dm_target *ti,
616 unsigned int target_bio_nr, unsigned int *len, gfp_t gfp_mask)
617{
618 struct mapped_device *md = ci->io->md;
619 struct dm_target_io *tio;
620 struct bio *clone;
621
622 if (!ci->io->tio.io) {
623 /* the dm_target_io embedded in ci->io is available */
624 tio = &ci->io->tio;
625 /* alloc_io() already initialized embedded clone */
626 clone = &tio->clone;
627 } else {
628 clone = bio_alloc_clone(NULL, ci->bio, gfp_mask,
629 &md->mempools->bs);
630 if (!clone)
631 return NULL;
632
633 /* REQ_DM_POLL_LIST shouldn't be inherited */
634 clone->bi_opf &= ~REQ_DM_POLL_LIST;
635
636 tio = clone_to_tio(clone);
637 tio->flags = 0; /* also clears DM_TIO_INSIDE_DM_IO */
638 }
639
640 tio->magic = DM_TIO_MAGIC;
641 tio->io = ci->io;
642 tio->ti = ti;
643 tio->target_bio_nr = target_bio_nr;
644 tio->len_ptr = len;
645 tio->old_sector = 0;
646
647 /* Set default bdev, but target must bio_set_dev() before issuing IO */
648 clone->bi_bdev = md->disk->part0;
649 if (likely(ti != NULL) && unlikely(ti->needs_bio_set_dev))
650 bio_set_dev(clone, md->disk->part0);
651
652 if (len) {
653 clone->bi_iter.bi_size = to_bytes(*len);
654 if (bio_integrity(clone))
655 bio_integrity_trim(clone);
656 }
657
658 return clone;
659}
660
661static void free_tio(struct bio *clone)
662{
663 if (dm_tio_flagged(clone_to_tio(clone), DM_TIO_INSIDE_DM_IO))
664 return;
665 bio_put(clone);
666}
667
668/*
669 * Add the bio to the list of deferred io.
670 */
671static void queue_io(struct mapped_device *md, struct bio *bio)
672{
673 unsigned long flags;
674
675 spin_lock_irqsave(&md->deferred_lock, flags);
676 bio_list_add(&md->deferred, bio);
677 spin_unlock_irqrestore(&md->deferred_lock, flags);
678 queue_work(md->wq, &md->work);
679}
680
681/*
682 * Everyone (including functions in this file), should use this
683 * function to access the md->map field, and make sure they call
684 * dm_put_live_table() when finished.
685 */
686struct dm_table *dm_get_live_table(struct mapped_device *md,
687 int *srcu_idx) __acquires(md->io_barrier)
688{
689 *srcu_idx = srcu_read_lock(&md->io_barrier);
690
691 return srcu_dereference(md->map, &md->io_barrier);
692}
693
694void dm_put_live_table(struct mapped_device *md,
695 int srcu_idx) __releases(md->io_barrier)
696{
697 srcu_read_unlock(&md->io_barrier, srcu_idx);
698}
699
700void dm_sync_table(struct mapped_device *md)
701{
702 synchronize_srcu(&md->io_barrier);
703 synchronize_rcu_expedited();
704}
705
706/*
707 * A fast alternative to dm_get_live_table/dm_put_live_table.
708 * The caller must not block between these two functions.
709 */
710static struct dm_table *dm_get_live_table_fast(struct mapped_device *md) __acquires(RCU)
711{
712 rcu_read_lock();
713 return rcu_dereference(md->map);
714}
715
716static void dm_put_live_table_fast(struct mapped_device *md) __releases(RCU)
717{
718 rcu_read_unlock();
719}
720
721static char *_dm_claim_ptr = "I belong to device-mapper";
722
723/*
724 * Open a table device so we can use it as a map destination.
725 */
726static struct table_device *open_table_device(struct mapped_device *md,
727 dev_t dev, blk_mode_t mode)
728{
729 struct table_device *td;
730 struct file *bdev_file;
731 struct block_device *bdev;
732 u64 part_off;
733 int r;
734
735 td = kmalloc_node(sizeof(*td), GFP_KERNEL, md->numa_node_id);
736 if (!td)
737 return ERR_PTR(-ENOMEM);
738 refcount_set(&td->count, 1);
739
740 bdev_file = bdev_file_open_by_dev(dev, mode, _dm_claim_ptr, NULL);
741 if (IS_ERR(bdev_file)) {
742 r = PTR_ERR(bdev_file);
743 goto out_free_td;
744 }
745
746 bdev = file_bdev(bdev_file);
747
748 /*
749 * We can be called before the dm disk is added. In that case we can't
750 * register the holder relation here. It will be done once add_disk was
751 * called.
752 */
753 if (md->disk->slave_dir) {
754 r = bd_link_disk_holder(bdev, md->disk);
755 if (r)
756 goto out_blkdev_put;
757 }
758
759 td->dm_dev.mode = mode;
760 td->dm_dev.bdev = bdev;
761 td->dm_dev.bdev_file = bdev_file;
762 td->dm_dev.dax_dev = fs_dax_get_by_bdev(bdev, &part_off,
763 NULL, NULL);
764 format_dev_t(td->dm_dev.name, dev);
765 list_add(&td->list, &md->table_devices);
766 return td;
767
768out_blkdev_put:
769 __fput_sync(bdev_file);
770out_free_td:
771 kfree(td);
772 return ERR_PTR(r);
773}
774
775/*
776 * Close a table device that we've been using.
777 */
778static void close_table_device(struct table_device *td, struct mapped_device *md)
779{
780 if (md->disk->slave_dir)
781 bd_unlink_disk_holder(td->dm_dev.bdev, md->disk);
782
783 /* Leverage async fput() if DMF_DEFERRED_REMOVE set */
784 if (unlikely(test_bit(DMF_DEFERRED_REMOVE, &md->flags)))
785 fput(td->dm_dev.bdev_file);
786 else
787 __fput_sync(td->dm_dev.bdev_file);
788
789 put_dax(td->dm_dev.dax_dev);
790 list_del(&td->list);
791 kfree(td);
792}
793
794static struct table_device *find_table_device(struct list_head *l, dev_t dev,
795 blk_mode_t mode)
796{
797 struct table_device *td;
798
799 list_for_each_entry(td, l, list)
800 if (td->dm_dev.bdev->bd_dev == dev && td->dm_dev.mode == mode)
801 return td;
802
803 return NULL;
804}
805
806int dm_get_table_device(struct mapped_device *md, dev_t dev, blk_mode_t mode,
807 struct dm_dev **result)
808{
809 struct table_device *td;
810
811 mutex_lock(&md->table_devices_lock);
812 td = find_table_device(&md->table_devices, dev, mode);
813 if (!td) {
814 td = open_table_device(md, dev, mode);
815 if (IS_ERR(td)) {
816 mutex_unlock(&md->table_devices_lock);
817 return PTR_ERR(td);
818 }
819 } else {
820 refcount_inc(&td->count);
821 }
822 mutex_unlock(&md->table_devices_lock);
823
824 *result = &td->dm_dev;
825 return 0;
826}
827
828void dm_put_table_device(struct mapped_device *md, struct dm_dev *d)
829{
830 struct table_device *td = container_of(d, struct table_device, dm_dev);
831
832 mutex_lock(&md->table_devices_lock);
833 if (refcount_dec_and_test(&td->count))
834 close_table_device(td, md);
835 mutex_unlock(&md->table_devices_lock);
836}
837
838/*
839 * Get the geometry associated with a dm device
840 */
841int dm_get_geometry(struct mapped_device *md, struct hd_geometry *geo)
842{
843 *geo = md->geometry;
844
845 return 0;
846}
847
848/*
849 * Set the geometry of a device.
850 */
851int dm_set_geometry(struct mapped_device *md, struct hd_geometry *geo)
852{
853 sector_t sz = (sector_t)geo->cylinders * geo->heads * geo->sectors;
854
855 if (geo->start > sz) {
856 DMERR("Start sector is beyond the geometry limits.");
857 return -EINVAL;
858 }
859
860 md->geometry = *geo;
861
862 return 0;
863}
864
865static int __noflush_suspending(struct mapped_device *md)
866{
867 return test_bit(DMF_NOFLUSH_SUSPENDING, &md->flags);
868}
869
870static void dm_requeue_add_io(struct dm_io *io, bool first_stage)
871{
872 struct mapped_device *md = io->md;
873
874 if (first_stage) {
875 struct dm_io *next = md->requeue_list;
876
877 md->requeue_list = io;
878 io->next = next;
879 } else {
880 bio_list_add_head(&md->deferred, io->orig_bio);
881 }
882}
883
884static void dm_kick_requeue(struct mapped_device *md, bool first_stage)
885{
886 if (first_stage)
887 queue_work(md->wq, &md->requeue_work);
888 else
889 queue_work(md->wq, &md->work);
890}
891
892/*
893 * Return true if the dm_io's original bio is requeued.
894 * io->status is updated with error if requeue disallowed.
895 */
896static bool dm_handle_requeue(struct dm_io *io, bool first_stage)
897{
898 struct bio *bio = io->orig_bio;
899 bool handle_requeue = (io->status == BLK_STS_DM_REQUEUE);
900 bool handle_polled_eagain = ((io->status == BLK_STS_AGAIN) &&
901 (bio->bi_opf & REQ_POLLED));
902 struct mapped_device *md = io->md;
903 bool requeued = false;
904
905 if (handle_requeue || handle_polled_eagain) {
906 unsigned long flags;
907
908 if (bio->bi_opf & REQ_POLLED) {
909 /*
910 * Upper layer won't help us poll split bio
911 * (io->orig_bio may only reflect a subset of the
912 * pre-split original) so clear REQ_POLLED.
913 */
914 bio_clear_polled(bio);
915 }
916
917 /*
918 * Target requested pushing back the I/O or
919 * polled IO hit BLK_STS_AGAIN.
920 */
921 spin_lock_irqsave(&md->deferred_lock, flags);
922 if ((__noflush_suspending(md) &&
923 !WARN_ON_ONCE(dm_is_zone_write(md, bio))) ||
924 handle_polled_eagain || first_stage) {
925 dm_requeue_add_io(io, first_stage);
926 requeued = true;
927 } else {
928 /*
929 * noflush suspend was interrupted or this is
930 * a write to a zoned target.
931 */
932 io->status = BLK_STS_IOERR;
933 }
934 spin_unlock_irqrestore(&md->deferred_lock, flags);
935 }
936
937 if (requeued)
938 dm_kick_requeue(md, first_stage);
939
940 return requeued;
941}
942
943static void __dm_io_complete(struct dm_io *io, bool first_stage)
944{
945 struct bio *bio = io->orig_bio;
946 struct mapped_device *md = io->md;
947 blk_status_t io_error;
948 bool requeued;
949
950 requeued = dm_handle_requeue(io, first_stage);
951 if (requeued && first_stage)
952 return;
953
954 io_error = io->status;
955 if (dm_io_flagged(io, DM_IO_ACCOUNTED))
956 dm_end_io_acct(io);
957 else if (!io_error) {
958 /*
959 * Must handle target that DM_MAPIO_SUBMITTED only to
960 * then bio_endio() rather than dm_submit_bio_remap()
961 */
962 __dm_start_io_acct(io);
963 dm_end_io_acct(io);
964 }
965 free_io(io);
966 smp_wmb();
967 this_cpu_dec(*md->pending_io);
968
969 /* nudge anyone waiting on suspend queue */
970 if (unlikely(wq_has_sleeper(&md->wait)))
971 wake_up(&md->wait);
972
973 /* Return early if the original bio was requeued */
974 if (requeued)
975 return;
976
977 if (bio_is_flush_with_data(bio)) {
978 /*
979 * Preflush done for flush with data, reissue
980 * without REQ_PREFLUSH.
981 */
982 bio->bi_opf &= ~REQ_PREFLUSH;
983 queue_io(md, bio);
984 } else {
985 /* done with normal IO or empty flush */
986 if (io_error)
987 bio->bi_status = io_error;
988 bio_endio(bio);
989 }
990}
991
992static void dm_wq_requeue_work(struct work_struct *work)
993{
994 struct mapped_device *md = container_of(work, struct mapped_device,
995 requeue_work);
996 unsigned long flags;
997 struct dm_io *io;
998
999 /* reuse deferred lock to simplify dm_handle_requeue */
1000 spin_lock_irqsave(&md->deferred_lock, flags);
1001 io = md->requeue_list;
1002 md->requeue_list = NULL;
1003 spin_unlock_irqrestore(&md->deferred_lock, flags);
1004
1005 while (io) {
1006 struct dm_io *next = io->next;
1007
1008 dm_io_rewind(io, &md->disk->bio_split);
1009
1010 io->next = NULL;
1011 __dm_io_complete(io, false);
1012 io = next;
1013 cond_resched();
1014 }
1015}
1016
1017/*
1018 * Two staged requeue:
1019 *
1020 * 1) io->orig_bio points to the real original bio, and the part mapped to
1021 * this io must be requeued, instead of other parts of the original bio.
1022 *
1023 * 2) io->orig_bio points to new cloned bio which matches the requeued dm_io.
1024 */
1025static void dm_io_complete(struct dm_io *io)
1026{
1027 bool first_requeue;
1028
1029 /*
1030 * Only dm_io that has been split needs two stage requeue, otherwise
1031 * we may run into long bio clone chain during suspend and OOM could
1032 * be triggered.
1033 *
1034 * Also flush data dm_io won't be marked as DM_IO_WAS_SPLIT, so they
1035 * also aren't handled via the first stage requeue.
1036 */
1037 if (dm_io_flagged(io, DM_IO_WAS_SPLIT))
1038 first_requeue = true;
1039 else
1040 first_requeue = false;
1041
1042 __dm_io_complete(io, first_requeue);
1043}
1044
1045/*
1046 * Decrements the number of outstanding ios that a bio has been
1047 * cloned into, completing the original io if necc.
1048 */
1049static inline void __dm_io_dec_pending(struct dm_io *io)
1050{
1051 if (atomic_dec_and_test(&io->io_count))
1052 dm_io_complete(io);
1053}
1054
1055static void dm_io_set_error(struct dm_io *io, blk_status_t error)
1056{
1057 unsigned long flags;
1058
1059 /* Push-back supersedes any I/O errors */
1060 spin_lock_irqsave(&io->lock, flags);
1061 if (!(io->status == BLK_STS_DM_REQUEUE &&
1062 __noflush_suspending(io->md))) {
1063 io->status = error;
1064 }
1065 spin_unlock_irqrestore(&io->lock, flags);
1066}
1067
1068static void dm_io_dec_pending(struct dm_io *io, blk_status_t error)
1069{
1070 if (unlikely(error))
1071 dm_io_set_error(io, error);
1072
1073 __dm_io_dec_pending(io);
1074}
1075
1076/*
1077 * The queue_limits are only valid as long as you have a reference
1078 * count on 'md'. But _not_ imposing verification to avoid atomic_read(),
1079 */
1080static inline struct queue_limits *dm_get_queue_limits(struct mapped_device *md)
1081{
1082 return &md->queue->limits;
1083}
1084
1085void disable_discard(struct mapped_device *md)
1086{
1087 struct queue_limits *limits = dm_get_queue_limits(md);
1088
1089 /* device doesn't really support DISCARD, disable it */
1090 limits->max_hw_discard_sectors = 0;
1091}
1092
1093void disable_write_zeroes(struct mapped_device *md)
1094{
1095 struct queue_limits *limits = dm_get_queue_limits(md);
1096
1097 /* device doesn't really support WRITE ZEROES, disable it */
1098 limits->max_write_zeroes_sectors = 0;
1099}
1100
1101static bool swap_bios_limit(struct dm_target *ti, struct bio *bio)
1102{
1103 return unlikely((bio->bi_opf & REQ_SWAP) != 0) && unlikely(ti->limit_swap_bios);
1104}
1105
1106static void clone_endio(struct bio *bio)
1107{
1108 blk_status_t error = bio->bi_status;
1109 struct dm_target_io *tio = clone_to_tio(bio);
1110 struct dm_target *ti = tio->ti;
1111 dm_endio_fn endio = likely(ti != NULL) ? ti->type->end_io : NULL;
1112 struct dm_io *io = tio->io;
1113 struct mapped_device *md = io->md;
1114
1115 if (unlikely(error == BLK_STS_TARGET)) {
1116 if (bio_op(bio) == REQ_OP_DISCARD &&
1117 !bdev_max_discard_sectors(bio->bi_bdev))
1118 disable_discard(md);
1119 else if (bio_op(bio) == REQ_OP_WRITE_ZEROES &&
1120 !bdev_write_zeroes_sectors(bio->bi_bdev))
1121 disable_write_zeroes(md);
1122 }
1123
1124 if (static_branch_unlikely(&zoned_enabled) &&
1125 unlikely(bdev_is_zoned(bio->bi_bdev)))
1126 dm_zone_endio(io, bio);
1127
1128 if (endio) {
1129 int r = endio(ti, bio, &error);
1130
1131 switch (r) {
1132 case DM_ENDIO_REQUEUE:
1133 if (static_branch_unlikely(&zoned_enabled)) {
1134 /*
1135 * Requeuing writes to a sequential zone of a zoned
1136 * target will break the sequential write pattern:
1137 * fail such IO.
1138 */
1139 if (WARN_ON_ONCE(dm_is_zone_write(md, bio)))
1140 error = BLK_STS_IOERR;
1141 else
1142 error = BLK_STS_DM_REQUEUE;
1143 } else
1144 error = BLK_STS_DM_REQUEUE;
1145 fallthrough;
1146 case DM_ENDIO_DONE:
1147 break;
1148 case DM_ENDIO_INCOMPLETE:
1149 /* The target will handle the io */
1150 return;
1151 default:
1152 DMCRIT("unimplemented target endio return value: %d", r);
1153 BUG();
1154 }
1155 }
1156
1157 if (static_branch_unlikely(&swap_bios_enabled) &&
1158 likely(ti != NULL) && unlikely(swap_bios_limit(ti, bio)))
1159 up(&md->swap_bios_semaphore);
1160
1161 free_tio(bio);
1162 dm_io_dec_pending(io, error);
1163}
1164
1165/*
1166 * Return maximum size of I/O possible at the supplied sector up to the current
1167 * target boundary.
1168 */
1169static inline sector_t max_io_len_target_boundary(struct dm_target *ti,
1170 sector_t target_offset)
1171{
1172 return ti->len - target_offset;
1173}
1174
1175static sector_t __max_io_len(struct dm_target *ti, sector_t sector,
1176 unsigned int max_granularity,
1177 unsigned int max_sectors)
1178{
1179 sector_t target_offset = dm_target_offset(ti, sector);
1180 sector_t len = max_io_len_target_boundary(ti, target_offset);
1181
1182 /*
1183 * Does the target need to split IO even further?
1184 * - varied (per target) IO splitting is a tenet of DM; this
1185 * explains why stacked chunk_sectors based splitting via
1186 * bio_split_to_limits() isn't possible here.
1187 */
1188 if (!max_granularity)
1189 return len;
1190 return min_t(sector_t, len,
1191 min(max_sectors ? : queue_max_sectors(ti->table->md->queue),
1192 blk_boundary_sectors_left(target_offset, max_granularity)));
1193}
1194
1195static inline sector_t max_io_len(struct dm_target *ti, sector_t sector)
1196{
1197 return __max_io_len(ti, sector, ti->max_io_len, 0);
1198}
1199
1200int dm_set_target_max_io_len(struct dm_target *ti, sector_t len)
1201{
1202 if (len > UINT_MAX) {
1203 DMERR("Specified maximum size of target IO (%llu) exceeds limit (%u)",
1204 (unsigned long long)len, UINT_MAX);
1205 ti->error = "Maximum size of target IO is too large";
1206 return -EINVAL;
1207 }
1208
1209 ti->max_io_len = (uint32_t) len;
1210
1211 return 0;
1212}
1213EXPORT_SYMBOL_GPL(dm_set_target_max_io_len);
1214
1215static struct dm_target *dm_dax_get_live_target(struct mapped_device *md,
1216 sector_t sector, int *srcu_idx)
1217 __acquires(md->io_barrier)
1218{
1219 struct dm_table *map;
1220 struct dm_target *ti;
1221
1222 map = dm_get_live_table(md, srcu_idx);
1223 if (!map)
1224 return NULL;
1225
1226 ti = dm_table_find_target(map, sector);
1227 if (!ti)
1228 return NULL;
1229
1230 return ti;
1231}
1232
1233static long dm_dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff,
1234 long nr_pages, enum dax_access_mode mode, void **kaddr,
1235 pfn_t *pfn)
1236{
1237 struct mapped_device *md = dax_get_private(dax_dev);
1238 sector_t sector = pgoff * PAGE_SECTORS;
1239 struct dm_target *ti;
1240 long len, ret = -EIO;
1241 int srcu_idx;
1242
1243 ti = dm_dax_get_live_target(md, sector, &srcu_idx);
1244
1245 if (!ti)
1246 goto out;
1247 if (!ti->type->direct_access)
1248 goto out;
1249 len = max_io_len(ti, sector) / PAGE_SECTORS;
1250 if (len < 1)
1251 goto out;
1252 nr_pages = min(len, nr_pages);
1253 ret = ti->type->direct_access(ti, pgoff, nr_pages, mode, kaddr, pfn);
1254
1255 out:
1256 dm_put_live_table(md, srcu_idx);
1257
1258 return ret;
1259}
1260
1261static int dm_dax_zero_page_range(struct dax_device *dax_dev, pgoff_t pgoff,
1262 size_t nr_pages)
1263{
1264 struct mapped_device *md = dax_get_private(dax_dev);
1265 sector_t sector = pgoff * PAGE_SECTORS;
1266 struct dm_target *ti;
1267 int ret = -EIO;
1268 int srcu_idx;
1269
1270 ti = dm_dax_get_live_target(md, sector, &srcu_idx);
1271
1272 if (!ti)
1273 goto out;
1274 if (WARN_ON(!ti->type->dax_zero_page_range)) {
1275 /*
1276 * ->zero_page_range() is mandatory dax operation. If we are
1277 * here, something is wrong.
1278 */
1279 goto out;
1280 }
1281 ret = ti->type->dax_zero_page_range(ti, pgoff, nr_pages);
1282 out:
1283 dm_put_live_table(md, srcu_idx);
1284
1285 return ret;
1286}
1287
1288static size_t dm_dax_recovery_write(struct dax_device *dax_dev, pgoff_t pgoff,
1289 void *addr, size_t bytes, struct iov_iter *i)
1290{
1291 struct mapped_device *md = dax_get_private(dax_dev);
1292 sector_t sector = pgoff * PAGE_SECTORS;
1293 struct dm_target *ti;
1294 int srcu_idx;
1295 long ret = 0;
1296
1297 ti = dm_dax_get_live_target(md, sector, &srcu_idx);
1298 if (!ti || !ti->type->dax_recovery_write)
1299 goto out;
1300
1301 ret = ti->type->dax_recovery_write(ti, pgoff, addr, bytes, i);
1302out:
1303 dm_put_live_table(md, srcu_idx);
1304 return ret;
1305}
1306
1307/*
1308 * A target may call dm_accept_partial_bio only from the map routine. It is
1309 * allowed for all bio types except REQ_PREFLUSH, REQ_OP_ZONE_* zone management
1310 * operations, REQ_OP_ZONE_APPEND (zone append writes) and any bio serviced by
1311 * __send_duplicate_bios().
1312 *
1313 * dm_accept_partial_bio informs the dm that the target only wants to process
1314 * additional n_sectors sectors of the bio and the rest of the data should be
1315 * sent in a next bio.
1316 *
1317 * A diagram that explains the arithmetics:
1318 * +--------------------+---------------+-------+
1319 * | 1 | 2 | 3 |
1320 * +--------------------+---------------+-------+
1321 *
1322 * <-------------- *tio->len_ptr --------------->
1323 * <----- bio_sectors ----->
1324 * <-- n_sectors -->
1325 *
1326 * Region 1 was already iterated over with bio_advance or similar function.
1327 * (it may be empty if the target doesn't use bio_advance)
1328 * Region 2 is the remaining bio size that the target wants to process.
1329 * (it may be empty if region 1 is non-empty, although there is no reason
1330 * to make it empty)
1331 * The target requires that region 3 is to be sent in the next bio.
1332 *
1333 * If the target wants to receive multiple copies of the bio (via num_*bios, etc),
1334 * the partially processed part (the sum of regions 1+2) must be the same for all
1335 * copies of the bio.
1336 */
1337void dm_accept_partial_bio(struct bio *bio, unsigned int n_sectors)
1338{
1339 struct dm_target_io *tio = clone_to_tio(bio);
1340 struct dm_io *io = tio->io;
1341 unsigned int bio_sectors = bio_sectors(bio);
1342
1343 BUG_ON(dm_tio_flagged(tio, DM_TIO_IS_DUPLICATE_BIO));
1344 BUG_ON(op_is_zone_mgmt(bio_op(bio)));
1345 BUG_ON(bio_op(bio) == REQ_OP_ZONE_APPEND);
1346 BUG_ON(bio_sectors > *tio->len_ptr);
1347 BUG_ON(n_sectors > bio_sectors);
1348
1349 *tio->len_ptr -= bio_sectors - n_sectors;
1350 bio->bi_iter.bi_size = n_sectors << SECTOR_SHIFT;
1351
1352 /*
1353 * __split_and_process_bio() may have already saved mapped part
1354 * for accounting but it is being reduced so update accordingly.
1355 */
1356 dm_io_set_flag(io, DM_IO_WAS_SPLIT);
1357 io->sectors = n_sectors;
1358 io->sector_offset = bio_sectors(io->orig_bio);
1359}
1360EXPORT_SYMBOL_GPL(dm_accept_partial_bio);
1361
1362/*
1363 * @clone: clone bio that DM core passed to target's .map function
1364 * @tgt_clone: clone of @clone bio that target needs submitted
1365 *
1366 * Targets should use this interface to submit bios they take
1367 * ownership of when returning DM_MAPIO_SUBMITTED.
1368 *
1369 * Target should also enable ti->accounts_remapped_io
1370 */
1371void dm_submit_bio_remap(struct bio *clone, struct bio *tgt_clone)
1372{
1373 struct dm_target_io *tio = clone_to_tio(clone);
1374 struct dm_io *io = tio->io;
1375
1376 /* establish bio that will get submitted */
1377 if (!tgt_clone)
1378 tgt_clone = clone;
1379
1380 /*
1381 * Account io->origin_bio to DM dev on behalf of target
1382 * that took ownership of IO with DM_MAPIO_SUBMITTED.
1383 */
1384 dm_start_io_acct(io, clone);
1385
1386 trace_block_bio_remap(tgt_clone, disk_devt(io->md->disk),
1387 tio->old_sector);
1388 submit_bio_noacct(tgt_clone);
1389}
1390EXPORT_SYMBOL_GPL(dm_submit_bio_remap);
1391
1392static noinline void __set_swap_bios_limit(struct mapped_device *md, int latch)
1393{
1394 mutex_lock(&md->swap_bios_lock);
1395 while (latch < md->swap_bios) {
1396 cond_resched();
1397 down(&md->swap_bios_semaphore);
1398 md->swap_bios--;
1399 }
1400 while (latch > md->swap_bios) {
1401 cond_resched();
1402 up(&md->swap_bios_semaphore);
1403 md->swap_bios++;
1404 }
1405 mutex_unlock(&md->swap_bios_lock);
1406}
1407
1408static void __map_bio(struct bio *clone)
1409{
1410 struct dm_target_io *tio = clone_to_tio(clone);
1411 struct dm_target *ti = tio->ti;
1412 struct dm_io *io = tio->io;
1413 struct mapped_device *md = io->md;
1414 int r;
1415
1416 clone->bi_end_io = clone_endio;
1417
1418 /*
1419 * Map the clone.
1420 */
1421 tio->old_sector = clone->bi_iter.bi_sector;
1422
1423 if (static_branch_unlikely(&swap_bios_enabled) &&
1424 unlikely(swap_bios_limit(ti, clone))) {
1425 int latch = get_swap_bios();
1426
1427 if (unlikely(latch != md->swap_bios))
1428 __set_swap_bios_limit(md, latch);
1429 down(&md->swap_bios_semaphore);
1430 }
1431
1432 if (likely(ti->type->map == linear_map))
1433 r = linear_map(ti, clone);
1434 else if (ti->type->map == stripe_map)
1435 r = stripe_map(ti, clone);
1436 else
1437 r = ti->type->map(ti, clone);
1438
1439 switch (r) {
1440 case DM_MAPIO_SUBMITTED:
1441 /* target has assumed ownership of this io */
1442 if (!ti->accounts_remapped_io)
1443 dm_start_io_acct(io, clone);
1444 break;
1445 case DM_MAPIO_REMAPPED:
1446 dm_submit_bio_remap(clone, NULL);
1447 break;
1448 case DM_MAPIO_KILL:
1449 case DM_MAPIO_REQUEUE:
1450 if (static_branch_unlikely(&swap_bios_enabled) &&
1451 unlikely(swap_bios_limit(ti, clone)))
1452 up(&md->swap_bios_semaphore);
1453 free_tio(clone);
1454 if (r == DM_MAPIO_KILL)
1455 dm_io_dec_pending(io, BLK_STS_IOERR);
1456 else
1457 dm_io_dec_pending(io, BLK_STS_DM_REQUEUE);
1458 break;
1459 default:
1460 DMCRIT("unimplemented target map return value: %d", r);
1461 BUG();
1462 }
1463}
1464
1465static void setup_split_accounting(struct clone_info *ci, unsigned int len)
1466{
1467 struct dm_io *io = ci->io;
1468
1469 if (ci->sector_count > len) {
1470 /*
1471 * Split needed, save the mapped part for accounting.
1472 * NOTE: dm_accept_partial_bio() will update accordingly.
1473 */
1474 dm_io_set_flag(io, DM_IO_WAS_SPLIT);
1475 io->sectors = len;
1476 io->sector_offset = bio_sectors(ci->bio);
1477 }
1478}
1479
1480static void alloc_multiple_bios(struct bio_list *blist, struct clone_info *ci,
1481 struct dm_target *ti, unsigned int num_bios,
1482 unsigned *len, gfp_t gfp_flag)
1483{
1484 struct bio *bio;
1485 int try = (gfp_flag & GFP_NOWAIT) ? 0 : 1;
1486
1487 for (; try < 2; try++) {
1488 int bio_nr;
1489
1490 if (try && num_bios > 1)
1491 mutex_lock(&ci->io->md->table_devices_lock);
1492 for (bio_nr = 0; bio_nr < num_bios; bio_nr++) {
1493 bio = alloc_tio(ci, ti, bio_nr, len,
1494 try ? GFP_NOIO : GFP_NOWAIT);
1495 if (!bio)
1496 break;
1497
1498 bio_list_add(blist, bio);
1499 }
1500 if (try && num_bios > 1)
1501 mutex_unlock(&ci->io->md->table_devices_lock);
1502 if (bio_nr == num_bios)
1503 return;
1504
1505 while ((bio = bio_list_pop(blist)))
1506 free_tio(bio);
1507 }
1508}
1509
1510static unsigned int __send_duplicate_bios(struct clone_info *ci, struct dm_target *ti,
1511 unsigned int num_bios, unsigned int *len,
1512 gfp_t gfp_flag)
1513{
1514 struct bio_list blist = BIO_EMPTY_LIST;
1515 struct bio *clone;
1516 unsigned int ret = 0;
1517
1518 if (WARN_ON_ONCE(num_bios == 0)) /* num_bios = 0 is a bug in caller */
1519 return 0;
1520
1521 /* dm_accept_partial_bio() is not supported with shared tio->len_ptr */
1522 if (len)
1523 setup_split_accounting(ci, *len);
1524
1525 /*
1526 * Using alloc_multiple_bios(), even if num_bios is 1, to consistently
1527 * support allocating using GFP_NOWAIT with GFP_NOIO fallback.
1528 */
1529 alloc_multiple_bios(&blist, ci, ti, num_bios, len, gfp_flag);
1530 while ((clone = bio_list_pop(&blist))) {
1531 if (num_bios > 1)
1532 dm_tio_set_flag(clone_to_tio(clone), DM_TIO_IS_DUPLICATE_BIO);
1533 __map_bio(clone);
1534 ret += 1;
1535 }
1536
1537 return ret;
1538}
1539
1540static void __send_empty_flush(struct clone_info *ci)
1541{
1542 struct dm_table *t = ci->map;
1543 struct bio flush_bio;
1544
1545 /*
1546 * Use an on-stack bio for this, it's safe since we don't
1547 * need to reference it after submit. It's just used as
1548 * the basis for the clone(s).
1549 */
1550 bio_init(&flush_bio, ci->io->md->disk->part0, NULL, 0,
1551 REQ_OP_WRITE | REQ_PREFLUSH | REQ_SYNC);
1552
1553 ci->bio = &flush_bio;
1554 ci->sector_count = 0;
1555 ci->io->tio.clone.bi_iter.bi_size = 0;
1556
1557 if (!t->flush_bypasses_map) {
1558 for (unsigned int i = 0; i < t->num_targets; i++) {
1559 unsigned int bios;
1560 struct dm_target *ti = dm_table_get_target(t, i);
1561
1562 if (unlikely(ti->num_flush_bios == 0))
1563 continue;
1564
1565 atomic_add(ti->num_flush_bios, &ci->io->io_count);
1566 bios = __send_duplicate_bios(ci, ti, ti->num_flush_bios,
1567 NULL, GFP_NOWAIT);
1568 atomic_sub(ti->num_flush_bios - bios, &ci->io->io_count);
1569 }
1570 } else {
1571 /*
1572 * Note that there's no need to grab t->devices_lock here
1573 * because the targets that support flush optimization don't
1574 * modify the list of devices.
1575 */
1576 struct list_head *devices = dm_table_get_devices(t);
1577 unsigned int len = 0;
1578 struct dm_dev_internal *dd;
1579 list_for_each_entry(dd, devices, list) {
1580 struct bio *clone;
1581 /*
1582 * Note that the structure dm_target_io is not
1583 * associated with any target (because the device may be
1584 * used by multiple targets), so we set tio->ti = NULL.
1585 * We must check for NULL in the I/O processing path, to
1586 * avoid NULL pointer dereference.
1587 */
1588 clone = alloc_tio(ci, NULL, 0, &len, GFP_NOIO);
1589 atomic_add(1, &ci->io->io_count);
1590 bio_set_dev(clone, dd->dm_dev->bdev);
1591 clone->bi_end_io = clone_endio;
1592 dm_submit_bio_remap(clone, NULL);
1593 }
1594 }
1595
1596 /*
1597 * alloc_io() takes one extra reference for submission, so the
1598 * reference won't reach 0 without the following subtraction
1599 */
1600 atomic_sub(1, &ci->io->io_count);
1601
1602 bio_uninit(ci->bio);
1603}
1604
1605static void __send_abnormal_io(struct clone_info *ci, struct dm_target *ti,
1606 unsigned int num_bios, unsigned int max_granularity,
1607 unsigned int max_sectors)
1608{
1609 unsigned int len, bios;
1610
1611 len = min_t(sector_t, ci->sector_count,
1612 __max_io_len(ti, ci->sector, max_granularity, max_sectors));
1613
1614 atomic_add(num_bios, &ci->io->io_count);
1615 bios = __send_duplicate_bios(ci, ti, num_bios, &len, GFP_NOIO);
1616 /*
1617 * alloc_io() takes one extra reference for submission, so the
1618 * reference won't reach 0 without the following (+1) subtraction
1619 */
1620 atomic_sub(num_bios - bios + 1, &ci->io->io_count);
1621
1622 ci->sector += len;
1623 ci->sector_count -= len;
1624}
1625
1626static bool is_abnormal_io(struct bio *bio)
1627{
1628 switch (bio_op(bio)) {
1629 case REQ_OP_READ:
1630 case REQ_OP_WRITE:
1631 case REQ_OP_FLUSH:
1632 return false;
1633 case REQ_OP_DISCARD:
1634 case REQ_OP_SECURE_ERASE:
1635 case REQ_OP_WRITE_ZEROES:
1636 case REQ_OP_ZONE_RESET_ALL:
1637 return true;
1638 default:
1639 return false;
1640 }
1641}
1642
1643static blk_status_t __process_abnormal_io(struct clone_info *ci,
1644 struct dm_target *ti)
1645{
1646 unsigned int num_bios = 0;
1647 unsigned int max_granularity = 0;
1648 unsigned int max_sectors = 0;
1649 struct queue_limits *limits = dm_get_queue_limits(ti->table->md);
1650
1651 switch (bio_op(ci->bio)) {
1652 case REQ_OP_DISCARD:
1653 num_bios = ti->num_discard_bios;
1654 max_sectors = limits->max_discard_sectors;
1655 if (ti->max_discard_granularity)
1656 max_granularity = max_sectors;
1657 break;
1658 case REQ_OP_SECURE_ERASE:
1659 num_bios = ti->num_secure_erase_bios;
1660 max_sectors = limits->max_secure_erase_sectors;
1661 break;
1662 case REQ_OP_WRITE_ZEROES:
1663 num_bios = ti->num_write_zeroes_bios;
1664 max_sectors = limits->max_write_zeroes_sectors;
1665 break;
1666 default:
1667 break;
1668 }
1669
1670 /*
1671 * Even though the device advertised support for this type of
1672 * request, that does not mean every target supports it, and
1673 * reconfiguration might also have changed that since the
1674 * check was performed.
1675 */
1676 if (unlikely(!num_bios))
1677 return BLK_STS_NOTSUPP;
1678
1679 __send_abnormal_io(ci, ti, num_bios, max_granularity, max_sectors);
1680
1681 return BLK_STS_OK;
1682}
1683
1684/*
1685 * Reuse ->bi_private as dm_io list head for storing all dm_io instances
1686 * associated with this bio, and this bio's bi_private needs to be
1687 * stored in dm_io->data before the reuse.
1688 *
1689 * bio->bi_private is owned by fs or upper layer, so block layer won't
1690 * touch it after splitting. Meantime it won't be changed by anyone after
1691 * bio is submitted. So this reuse is safe.
1692 */
1693static inline struct dm_io **dm_poll_list_head(struct bio *bio)
1694{
1695 return (struct dm_io **)&bio->bi_private;
1696}
1697
1698static void dm_queue_poll_io(struct bio *bio, struct dm_io *io)
1699{
1700 struct dm_io **head = dm_poll_list_head(bio);
1701
1702 if (!(bio->bi_opf & REQ_DM_POLL_LIST)) {
1703 bio->bi_opf |= REQ_DM_POLL_LIST;
1704 /*
1705 * Save .bi_private into dm_io, so that we can reuse
1706 * .bi_private as dm_io list head for storing dm_io list
1707 */
1708 io->data = bio->bi_private;
1709
1710 /* tell block layer to poll for completion */
1711 bio->bi_cookie = ~BLK_QC_T_NONE;
1712
1713 io->next = NULL;
1714 } else {
1715 /*
1716 * bio recursed due to split, reuse original poll list,
1717 * and save bio->bi_private too.
1718 */
1719 io->data = (*head)->data;
1720 io->next = *head;
1721 }
1722
1723 *head = io;
1724}
1725
1726/*
1727 * Select the correct strategy for processing a non-flush bio.
1728 */
1729static blk_status_t __split_and_process_bio(struct clone_info *ci)
1730{
1731 struct bio *clone;
1732 struct dm_target *ti;
1733 unsigned int len;
1734
1735 ti = dm_table_find_target(ci->map, ci->sector);
1736 if (unlikely(!ti))
1737 return BLK_STS_IOERR;
1738
1739 if (unlikely(ci->is_abnormal_io))
1740 return __process_abnormal_io(ci, ti);
1741
1742 /*
1743 * Only support bio polling for normal IO, and the target io is
1744 * exactly inside the dm_io instance (verified in dm_poll_dm_io)
1745 */
1746 ci->submit_as_polled = !!(ci->bio->bi_opf & REQ_POLLED);
1747
1748 len = min_t(sector_t, max_io_len(ti, ci->sector), ci->sector_count);
1749 setup_split_accounting(ci, len);
1750
1751 if (unlikely(ci->bio->bi_opf & REQ_NOWAIT)) {
1752 if (unlikely(!dm_target_supports_nowait(ti->type)))
1753 return BLK_STS_NOTSUPP;
1754
1755 clone = alloc_tio(ci, ti, 0, &len, GFP_NOWAIT);
1756 if (unlikely(!clone))
1757 return BLK_STS_AGAIN;
1758 } else {
1759 clone = alloc_tio(ci, ti, 0, &len, GFP_NOIO);
1760 }
1761 __map_bio(clone);
1762
1763 ci->sector += len;
1764 ci->sector_count -= len;
1765
1766 return BLK_STS_OK;
1767}
1768
1769static void init_clone_info(struct clone_info *ci, struct dm_io *io,
1770 struct dm_table *map, struct bio *bio, bool is_abnormal)
1771{
1772 ci->map = map;
1773 ci->io = io;
1774 ci->bio = bio;
1775 ci->is_abnormal_io = is_abnormal;
1776 ci->submit_as_polled = false;
1777 ci->sector = bio->bi_iter.bi_sector;
1778 ci->sector_count = bio_sectors(bio);
1779
1780 /* Shouldn't happen but sector_count was being set to 0 so... */
1781 if (static_branch_unlikely(&zoned_enabled) &&
1782 WARN_ON_ONCE(op_is_zone_mgmt(bio_op(bio)) && ci->sector_count))
1783 ci->sector_count = 0;
1784}
1785
1786#ifdef CONFIG_BLK_DEV_ZONED
1787static inline bool dm_zone_bio_needs_split(struct mapped_device *md,
1788 struct bio *bio)
1789{
1790 /*
1791 * For mapped device that need zone append emulation, we must
1792 * split any large BIO that straddles zone boundaries.
1793 */
1794 return dm_emulate_zone_append(md) && bio_straddles_zones(bio) &&
1795 !bio_flagged(bio, BIO_ZONE_WRITE_PLUGGING);
1796}
1797static inline bool dm_zone_plug_bio(struct mapped_device *md, struct bio *bio)
1798{
1799 return dm_emulate_zone_append(md) && blk_zone_plug_bio(bio, 0);
1800}
1801
1802static blk_status_t __send_zone_reset_all_emulated(struct clone_info *ci,
1803 struct dm_target *ti)
1804{
1805 struct bio_list blist = BIO_EMPTY_LIST;
1806 struct mapped_device *md = ci->io->md;
1807 unsigned int zone_sectors = md->disk->queue->limits.chunk_sectors;
1808 unsigned long *need_reset;
1809 unsigned int i, nr_zones, nr_reset;
1810 unsigned int num_bios = 0;
1811 blk_status_t sts = BLK_STS_OK;
1812 sector_t sector = ti->begin;
1813 struct bio *clone;
1814 int ret;
1815
1816 nr_zones = ti->len >> ilog2(zone_sectors);
1817 need_reset = bitmap_zalloc(nr_zones, GFP_NOIO);
1818 if (!need_reset)
1819 return BLK_STS_RESOURCE;
1820
1821 ret = dm_zone_get_reset_bitmap(md, ci->map, ti->begin,
1822 nr_zones, need_reset);
1823 if (ret) {
1824 sts = BLK_STS_IOERR;
1825 goto free_bitmap;
1826 }
1827
1828 /* If we have no zone to reset, we are done. */
1829 nr_reset = bitmap_weight(need_reset, nr_zones);
1830 if (!nr_reset)
1831 goto free_bitmap;
1832
1833 atomic_add(nr_zones, &ci->io->io_count);
1834
1835 for (i = 0; i < nr_zones; i++) {
1836
1837 if (!test_bit(i, need_reset)) {
1838 sector += zone_sectors;
1839 continue;
1840 }
1841
1842 if (bio_list_empty(&blist)) {
1843 /* This may take a while, so be nice to others */
1844 if (num_bios)
1845 cond_resched();
1846
1847 /*
1848 * We may need to reset thousands of zones, so let's
1849 * not go crazy with the clone allocation.
1850 */
1851 alloc_multiple_bios(&blist, ci, ti, min(nr_reset, 32),
1852 NULL, GFP_NOIO);
1853 }
1854
1855 /* Get a clone and change it to a regular reset operation. */
1856 clone = bio_list_pop(&blist);
1857 clone->bi_opf &= ~REQ_OP_MASK;
1858 clone->bi_opf |= REQ_OP_ZONE_RESET | REQ_SYNC;
1859 clone->bi_iter.bi_sector = sector;
1860 clone->bi_iter.bi_size = 0;
1861 __map_bio(clone);
1862
1863 sector += zone_sectors;
1864 num_bios++;
1865 nr_reset--;
1866 }
1867
1868 WARN_ON_ONCE(!bio_list_empty(&blist));
1869 atomic_sub(nr_zones - num_bios, &ci->io->io_count);
1870 ci->sector_count = 0;
1871
1872free_bitmap:
1873 bitmap_free(need_reset);
1874
1875 return sts;
1876}
1877
1878static void __send_zone_reset_all_native(struct clone_info *ci,
1879 struct dm_target *ti)
1880{
1881 unsigned int bios;
1882
1883 atomic_add(1, &ci->io->io_count);
1884 bios = __send_duplicate_bios(ci, ti, 1, NULL, GFP_NOIO);
1885 atomic_sub(1 - bios, &ci->io->io_count);
1886
1887 ci->sector_count = 0;
1888}
1889
1890static blk_status_t __send_zone_reset_all(struct clone_info *ci)
1891{
1892 struct dm_table *t = ci->map;
1893 blk_status_t sts = BLK_STS_OK;
1894
1895 for (unsigned int i = 0; i < t->num_targets; i++) {
1896 struct dm_target *ti = dm_table_get_target(t, i);
1897
1898 if (ti->zone_reset_all_supported) {
1899 __send_zone_reset_all_native(ci, ti);
1900 continue;
1901 }
1902
1903 sts = __send_zone_reset_all_emulated(ci, ti);
1904 if (sts != BLK_STS_OK)
1905 break;
1906 }
1907
1908 /* Release the reference that alloc_io() took for submission. */
1909 atomic_sub(1, &ci->io->io_count);
1910
1911 return sts;
1912}
1913
1914#else
1915static inline bool dm_zone_bio_needs_split(struct mapped_device *md,
1916 struct bio *bio)
1917{
1918 return false;
1919}
1920static inline bool dm_zone_plug_bio(struct mapped_device *md, struct bio *bio)
1921{
1922 return false;
1923}
1924static blk_status_t __send_zone_reset_all(struct clone_info *ci)
1925{
1926 return BLK_STS_NOTSUPP;
1927}
1928#endif
1929
1930/*
1931 * Entry point to split a bio into clones and submit them to the targets.
1932 */
1933static void dm_split_and_process_bio(struct mapped_device *md,
1934 struct dm_table *map, struct bio *bio)
1935{
1936 struct clone_info ci;
1937 struct dm_io *io;
1938 blk_status_t error = BLK_STS_OK;
1939 bool is_abnormal, need_split;
1940
1941 is_abnormal = is_abnormal_io(bio);
1942 if (static_branch_unlikely(&zoned_enabled)) {
1943 /* Special case REQ_OP_ZONE_RESET_ALL as it cannot be split. */
1944 need_split = (bio_op(bio) != REQ_OP_ZONE_RESET_ALL) &&
1945 (is_abnormal || dm_zone_bio_needs_split(md, bio));
1946 } else {
1947 need_split = is_abnormal;
1948 }
1949
1950 if (unlikely(need_split)) {
1951 /*
1952 * Use bio_split_to_limits() for abnormal IO (e.g. discard, etc)
1953 * otherwise associated queue_limits won't be imposed.
1954 * Also split the BIO for mapped devices needing zone append
1955 * emulation to ensure that the BIO does not cross zone
1956 * boundaries.
1957 */
1958 bio = bio_split_to_limits(bio);
1959 if (!bio)
1960 return;
1961 }
1962
1963 /*
1964 * Use the block layer zone write plugging for mapped devices that
1965 * need zone append emulation (e.g. dm-crypt).
1966 */
1967 if (static_branch_unlikely(&zoned_enabled) && dm_zone_plug_bio(md, bio))
1968 return;
1969
1970 /* Only support nowait for normal IO */
1971 if (unlikely(bio->bi_opf & REQ_NOWAIT) && !is_abnormal) {
1972 io = alloc_io(md, bio, GFP_NOWAIT);
1973 if (unlikely(!io)) {
1974 /* Unable to do anything without dm_io. */
1975 bio_wouldblock_error(bio);
1976 return;
1977 }
1978 } else {
1979 io = alloc_io(md, bio, GFP_NOIO);
1980 }
1981 init_clone_info(&ci, io, map, bio, is_abnormal);
1982
1983 if (bio->bi_opf & REQ_PREFLUSH) {
1984 __send_empty_flush(&ci);
1985 /* dm_io_complete submits any data associated with flush */
1986 goto out;
1987 }
1988
1989 if (static_branch_unlikely(&zoned_enabled) &&
1990 (bio_op(bio) == REQ_OP_ZONE_RESET_ALL)) {
1991 error = __send_zone_reset_all(&ci);
1992 goto out;
1993 }
1994
1995 error = __split_and_process_bio(&ci);
1996 if (error || !ci.sector_count)
1997 goto out;
1998 /*
1999 * Remainder must be passed to submit_bio_noacct() so it gets handled
2000 * *after* bios already submitted have been completely processed.
2001 */
2002 bio_trim(bio, io->sectors, ci.sector_count);
2003 trace_block_split(bio, bio->bi_iter.bi_sector);
2004 bio_inc_remaining(bio);
2005 submit_bio_noacct(bio);
2006out:
2007 /*
2008 * Drop the extra reference count for non-POLLED bio, and hold one
2009 * reference for POLLED bio, which will be released in dm_poll_bio
2010 *
2011 * Add every dm_io instance into the dm_io list head which is stored
2012 * in bio->bi_private, so that dm_poll_bio can poll them all.
2013 */
2014 if (error || !ci.submit_as_polled) {
2015 /*
2016 * In case of submission failure, the extra reference for
2017 * submitting io isn't consumed yet
2018 */
2019 if (error)
2020 atomic_dec(&io->io_count);
2021 dm_io_dec_pending(io, error);
2022 } else
2023 dm_queue_poll_io(bio, io);
2024}
2025
2026static void dm_submit_bio(struct bio *bio)
2027{
2028 struct mapped_device *md = bio->bi_bdev->bd_disk->private_data;
2029 int srcu_idx;
2030 struct dm_table *map;
2031
2032 map = dm_get_live_table(md, &srcu_idx);
2033 if (unlikely(!map)) {
2034 DMERR_LIMIT("%s: mapping table unavailable, erroring io",
2035 dm_device_name(md));
2036 bio_io_error(bio);
2037 goto out;
2038 }
2039
2040 /* If suspended, queue this IO for later */
2041 if (unlikely(test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags))) {
2042 if (bio->bi_opf & REQ_NOWAIT)
2043 bio_wouldblock_error(bio);
2044 else if (bio->bi_opf & REQ_RAHEAD)
2045 bio_io_error(bio);
2046 else
2047 queue_io(md, bio);
2048 goto out;
2049 }
2050
2051 dm_split_and_process_bio(md, map, bio);
2052out:
2053 dm_put_live_table(md, srcu_idx);
2054}
2055
2056static bool dm_poll_dm_io(struct dm_io *io, struct io_comp_batch *iob,
2057 unsigned int flags)
2058{
2059 WARN_ON_ONCE(!dm_tio_is_normal(&io->tio));
2060
2061 /* don't poll if the mapped io is done */
2062 if (atomic_read(&io->io_count) > 1)
2063 bio_poll(&io->tio.clone, iob, flags);
2064
2065 /* bio_poll holds the last reference */
2066 return atomic_read(&io->io_count) == 1;
2067}
2068
2069static int dm_poll_bio(struct bio *bio, struct io_comp_batch *iob,
2070 unsigned int flags)
2071{
2072 struct dm_io **head = dm_poll_list_head(bio);
2073 struct dm_io *list = *head;
2074 struct dm_io *tmp = NULL;
2075 struct dm_io *curr, *next;
2076
2077 /* Only poll normal bio which was marked as REQ_DM_POLL_LIST */
2078 if (!(bio->bi_opf & REQ_DM_POLL_LIST))
2079 return 0;
2080
2081 WARN_ON_ONCE(!list);
2082
2083 /*
2084 * Restore .bi_private before possibly completing dm_io.
2085 *
2086 * bio_poll() is only possible once @bio has been completely
2087 * submitted via submit_bio_noacct()'s depth-first submission.
2088 * So there is no dm_queue_poll_io() race associated with
2089 * clearing REQ_DM_POLL_LIST here.
2090 */
2091 bio->bi_opf &= ~REQ_DM_POLL_LIST;
2092 bio->bi_private = list->data;
2093
2094 for (curr = list, next = curr->next; curr; curr = next, next =
2095 curr ? curr->next : NULL) {
2096 if (dm_poll_dm_io(curr, iob, flags)) {
2097 /*
2098 * clone_endio() has already occurred, so no
2099 * error handling is needed here.
2100 */
2101 __dm_io_dec_pending(curr);
2102 } else {
2103 curr->next = tmp;
2104 tmp = curr;
2105 }
2106 }
2107
2108 /* Not done? */
2109 if (tmp) {
2110 bio->bi_opf |= REQ_DM_POLL_LIST;
2111 /* Reset bio->bi_private to dm_io list head */
2112 *head = tmp;
2113 return 0;
2114 }
2115 return 1;
2116}
2117
2118/*
2119 *---------------------------------------------------------------
2120 * An IDR is used to keep track of allocated minor numbers.
2121 *---------------------------------------------------------------
2122 */
2123static void free_minor(int minor)
2124{
2125 spin_lock(&_minor_lock);
2126 idr_remove(&_minor_idr, minor);
2127 spin_unlock(&_minor_lock);
2128}
2129
2130/*
2131 * See if the device with a specific minor # is free.
2132 */
2133static int specific_minor(int minor)
2134{
2135 int r;
2136
2137 if (minor >= (1 << MINORBITS))
2138 return -EINVAL;
2139
2140 idr_preload(GFP_KERNEL);
2141 spin_lock(&_minor_lock);
2142
2143 r = idr_alloc(&_minor_idr, MINOR_ALLOCED, minor, minor + 1, GFP_NOWAIT);
2144
2145 spin_unlock(&_minor_lock);
2146 idr_preload_end();
2147 if (r < 0)
2148 return r == -ENOSPC ? -EBUSY : r;
2149 return 0;
2150}
2151
2152static int next_free_minor(int *minor)
2153{
2154 int r;
2155
2156 idr_preload(GFP_KERNEL);
2157 spin_lock(&_minor_lock);
2158
2159 r = idr_alloc(&_minor_idr, MINOR_ALLOCED, 0, 1 << MINORBITS, GFP_NOWAIT);
2160
2161 spin_unlock(&_minor_lock);
2162 idr_preload_end();
2163 if (r < 0)
2164 return r;
2165 *minor = r;
2166 return 0;
2167}
2168
2169static const struct block_device_operations dm_blk_dops;
2170static const struct block_device_operations dm_rq_blk_dops;
2171static const struct dax_operations dm_dax_ops;
2172
2173static void dm_wq_work(struct work_struct *work);
2174
2175#ifdef CONFIG_BLK_INLINE_ENCRYPTION
2176static void dm_queue_destroy_crypto_profile(struct request_queue *q)
2177{
2178 dm_destroy_crypto_profile(q->crypto_profile);
2179}
2180
2181#else /* CONFIG_BLK_INLINE_ENCRYPTION */
2182
2183static inline void dm_queue_destroy_crypto_profile(struct request_queue *q)
2184{
2185}
2186#endif /* !CONFIG_BLK_INLINE_ENCRYPTION */
2187
2188static void cleanup_mapped_device(struct mapped_device *md)
2189{
2190 if (md->wq)
2191 destroy_workqueue(md->wq);
2192 dm_free_md_mempools(md->mempools);
2193
2194 if (md->dax_dev) {
2195 dax_remove_host(md->disk);
2196 kill_dax(md->dax_dev);
2197 put_dax(md->dax_dev);
2198 md->dax_dev = NULL;
2199 }
2200
2201 if (md->disk) {
2202 spin_lock(&_minor_lock);
2203 md->disk->private_data = NULL;
2204 spin_unlock(&_minor_lock);
2205 if (dm_get_md_type(md) != DM_TYPE_NONE) {
2206 struct table_device *td;
2207
2208 dm_sysfs_exit(md);
2209 list_for_each_entry(td, &md->table_devices, list) {
2210 bd_unlink_disk_holder(td->dm_dev.bdev,
2211 md->disk);
2212 }
2213
2214 /*
2215 * Hold lock to make sure del_gendisk() won't concurrent
2216 * with open/close_table_device().
2217 */
2218 mutex_lock(&md->table_devices_lock);
2219 del_gendisk(md->disk);
2220 mutex_unlock(&md->table_devices_lock);
2221 }
2222 dm_queue_destroy_crypto_profile(md->queue);
2223 put_disk(md->disk);
2224 }
2225
2226 if (md->pending_io) {
2227 free_percpu(md->pending_io);
2228 md->pending_io = NULL;
2229 }
2230
2231 cleanup_srcu_struct(&md->io_barrier);
2232
2233 mutex_destroy(&md->suspend_lock);
2234 mutex_destroy(&md->type_lock);
2235 mutex_destroy(&md->table_devices_lock);
2236 mutex_destroy(&md->swap_bios_lock);
2237
2238 dm_mq_cleanup_mapped_device(md);
2239}
2240
2241/*
2242 * Allocate and initialise a blank device with a given minor.
2243 */
2244static struct mapped_device *alloc_dev(int minor)
2245{
2246 int r, numa_node_id = dm_get_numa_node();
2247 struct dax_device *dax_dev;
2248 struct mapped_device *md;
2249 void *old_md;
2250
2251 md = kvzalloc_node(sizeof(*md), GFP_KERNEL, numa_node_id);
2252 if (!md) {
2253 DMERR("unable to allocate device, out of memory.");
2254 return NULL;
2255 }
2256
2257 if (!try_module_get(THIS_MODULE))
2258 goto bad_module_get;
2259
2260 /* get a minor number for the dev */
2261 if (minor == DM_ANY_MINOR)
2262 r = next_free_minor(&minor);
2263 else
2264 r = specific_minor(minor);
2265 if (r < 0)
2266 goto bad_minor;
2267
2268 r = init_srcu_struct(&md->io_barrier);
2269 if (r < 0)
2270 goto bad_io_barrier;
2271
2272 md->numa_node_id = numa_node_id;
2273 md->init_tio_pdu = false;
2274 md->type = DM_TYPE_NONE;
2275 mutex_init(&md->suspend_lock);
2276 mutex_init(&md->type_lock);
2277 mutex_init(&md->table_devices_lock);
2278 spin_lock_init(&md->deferred_lock);
2279 atomic_set(&md->holders, 1);
2280 atomic_set(&md->open_count, 0);
2281 atomic_set(&md->event_nr, 0);
2282 atomic_set(&md->uevent_seq, 0);
2283 INIT_LIST_HEAD(&md->uevent_list);
2284 INIT_LIST_HEAD(&md->table_devices);
2285 spin_lock_init(&md->uevent_lock);
2286
2287 /*
2288 * default to bio-based until DM table is loaded and md->type
2289 * established. If request-based table is loaded: blk-mq will
2290 * override accordingly.
2291 */
2292 md->disk = blk_alloc_disk(NULL, md->numa_node_id);
2293 if (IS_ERR(md->disk)) {
2294 md->disk = NULL;
2295 goto bad;
2296 }
2297 md->queue = md->disk->queue;
2298
2299 init_waitqueue_head(&md->wait);
2300 INIT_WORK(&md->work, dm_wq_work);
2301 INIT_WORK(&md->requeue_work, dm_wq_requeue_work);
2302 init_waitqueue_head(&md->eventq);
2303 init_completion(&md->kobj_holder.completion);
2304
2305 md->requeue_list = NULL;
2306 md->swap_bios = get_swap_bios();
2307 sema_init(&md->swap_bios_semaphore, md->swap_bios);
2308 mutex_init(&md->swap_bios_lock);
2309
2310 md->disk->major = _major;
2311 md->disk->first_minor = minor;
2312 md->disk->minors = 1;
2313 md->disk->flags |= GENHD_FL_NO_PART;
2314 md->disk->fops = &dm_blk_dops;
2315 md->disk->private_data = md;
2316 sprintf(md->disk->disk_name, "dm-%d", minor);
2317
2318 dax_dev = alloc_dax(md, &dm_dax_ops);
2319 if (IS_ERR(dax_dev)) {
2320 if (PTR_ERR(dax_dev) != -EOPNOTSUPP)
2321 goto bad;
2322 } else {
2323 set_dax_nocache(dax_dev);
2324 set_dax_nomc(dax_dev);
2325 md->dax_dev = dax_dev;
2326 if (dax_add_host(dax_dev, md->disk))
2327 goto bad;
2328 }
2329
2330 format_dev_t(md->name, MKDEV(_major, minor));
2331
2332 md->wq = alloc_workqueue("kdmflush/%s", WQ_MEM_RECLAIM, 0, md->name);
2333 if (!md->wq)
2334 goto bad;
2335
2336 md->pending_io = alloc_percpu(unsigned long);
2337 if (!md->pending_io)
2338 goto bad;
2339
2340 r = dm_stats_init(&md->stats);
2341 if (r < 0)
2342 goto bad;
2343
2344 /* Populate the mapping, nobody knows we exist yet */
2345 spin_lock(&_minor_lock);
2346 old_md = idr_replace(&_minor_idr, md, minor);
2347 spin_unlock(&_minor_lock);
2348
2349 BUG_ON(old_md != MINOR_ALLOCED);
2350
2351 return md;
2352
2353bad:
2354 cleanup_mapped_device(md);
2355bad_io_barrier:
2356 free_minor(minor);
2357bad_minor:
2358 module_put(THIS_MODULE);
2359bad_module_get:
2360 kvfree(md);
2361 return NULL;
2362}
2363
2364static void unlock_fs(struct mapped_device *md);
2365
2366static void free_dev(struct mapped_device *md)
2367{
2368 int minor = MINOR(disk_devt(md->disk));
2369
2370 unlock_fs(md);
2371
2372 cleanup_mapped_device(md);
2373
2374 WARN_ON_ONCE(!list_empty(&md->table_devices));
2375 dm_stats_cleanup(&md->stats);
2376 free_minor(minor);
2377
2378 module_put(THIS_MODULE);
2379 kvfree(md);
2380}
2381
2382/*
2383 * Bind a table to the device.
2384 */
2385static void event_callback(void *context)
2386{
2387 unsigned long flags;
2388 LIST_HEAD(uevents);
2389 struct mapped_device *md = context;
2390
2391 spin_lock_irqsave(&md->uevent_lock, flags);
2392 list_splice_init(&md->uevent_list, &uevents);
2393 spin_unlock_irqrestore(&md->uevent_lock, flags);
2394
2395 dm_send_uevents(&uevents, &disk_to_dev(md->disk)->kobj);
2396
2397 atomic_inc(&md->event_nr);
2398 wake_up(&md->eventq);
2399 dm_issue_global_event();
2400}
2401
2402/*
2403 * Returns old map, which caller must destroy.
2404 */
2405static struct dm_table *__bind(struct mapped_device *md, struct dm_table *t,
2406 struct queue_limits *limits)
2407{
2408 struct dm_table *old_map;
2409 sector_t size;
2410 int ret;
2411
2412 lockdep_assert_held(&md->suspend_lock);
2413
2414 size = dm_table_get_size(t);
2415
2416 /*
2417 * Wipe any geometry if the size of the table changed.
2418 */
2419 if (size != dm_get_size(md))
2420 memset(&md->geometry, 0, sizeof(md->geometry));
2421
2422 set_capacity(md->disk, size);
2423
2424 dm_table_event_callback(t, event_callback, md);
2425
2426 if (dm_table_request_based(t)) {
2427 /*
2428 * Leverage the fact that request-based DM targets are
2429 * immutable singletons - used to optimize dm_mq_queue_rq.
2430 */
2431 md->immutable_target = dm_table_get_immutable_target(t);
2432
2433 /*
2434 * There is no need to reload with request-based dm because the
2435 * size of front_pad doesn't change.
2436 *
2437 * Note for future: If you are to reload bioset, prep-ed
2438 * requests in the queue may refer to bio from the old bioset,
2439 * so you must walk through the queue to unprep.
2440 */
2441 if (!md->mempools) {
2442 md->mempools = t->mempools;
2443 t->mempools = NULL;
2444 }
2445 } else {
2446 /*
2447 * The md may already have mempools that need changing.
2448 * If so, reload bioset because front_pad may have changed
2449 * because a different table was loaded.
2450 */
2451 dm_free_md_mempools(md->mempools);
2452 md->mempools = t->mempools;
2453 t->mempools = NULL;
2454 }
2455
2456 ret = dm_table_set_restrictions(t, md->queue, limits);
2457 if (ret) {
2458 old_map = ERR_PTR(ret);
2459 goto out;
2460 }
2461
2462 old_map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock));
2463 rcu_assign_pointer(md->map, (void *)t);
2464 md->immutable_target_type = dm_table_get_immutable_target_type(t);
2465
2466 if (old_map)
2467 dm_sync_table(md);
2468out:
2469 return old_map;
2470}
2471
2472/*
2473 * Returns unbound table for the caller to free.
2474 */
2475static struct dm_table *__unbind(struct mapped_device *md)
2476{
2477 struct dm_table *map = rcu_dereference_protected(md->map, 1);
2478
2479 if (!map)
2480 return NULL;
2481
2482 dm_table_event_callback(map, NULL, NULL);
2483 RCU_INIT_POINTER(md->map, NULL);
2484 dm_sync_table(md);
2485
2486 return map;
2487}
2488
2489/*
2490 * Constructor for a new device.
2491 */
2492int dm_create(int minor, struct mapped_device **result)
2493{
2494 struct mapped_device *md;
2495
2496 md = alloc_dev(minor);
2497 if (!md)
2498 return -ENXIO;
2499
2500 dm_ima_reset_data(md);
2501
2502 *result = md;
2503 return 0;
2504}
2505
2506/*
2507 * Functions to manage md->type.
2508 * All are required to hold md->type_lock.
2509 */
2510void dm_lock_md_type(struct mapped_device *md)
2511{
2512 mutex_lock(&md->type_lock);
2513}
2514
2515void dm_unlock_md_type(struct mapped_device *md)
2516{
2517 mutex_unlock(&md->type_lock);
2518}
2519
2520enum dm_queue_mode dm_get_md_type(struct mapped_device *md)
2521{
2522 return md->type;
2523}
2524
2525struct target_type *dm_get_immutable_target_type(struct mapped_device *md)
2526{
2527 return md->immutable_target_type;
2528}
2529
2530/*
2531 * Setup the DM device's queue based on md's type
2532 */
2533int dm_setup_md_queue(struct mapped_device *md, struct dm_table *t)
2534{
2535 enum dm_queue_mode type = dm_table_get_type(t);
2536 struct queue_limits limits;
2537 struct table_device *td;
2538 int r;
2539
2540 WARN_ON_ONCE(type == DM_TYPE_NONE);
2541
2542 if (type == DM_TYPE_REQUEST_BASED) {
2543 md->disk->fops = &dm_rq_blk_dops;
2544 r = dm_mq_init_request_queue(md, t);
2545 if (r) {
2546 DMERR("Cannot initialize queue for request-based dm mapped device");
2547 return r;
2548 }
2549 }
2550
2551 r = dm_calculate_queue_limits(t, &limits);
2552 if (r) {
2553 DMERR("Cannot calculate initial queue limits");
2554 return r;
2555 }
2556 r = dm_table_set_restrictions(t, md->queue, &limits);
2557 if (r)
2558 return r;
2559
2560 /*
2561 * Hold lock to make sure add_disk() and del_gendisk() won't concurrent
2562 * with open_table_device() and close_table_device().
2563 */
2564 mutex_lock(&md->table_devices_lock);
2565 r = add_disk(md->disk);
2566 mutex_unlock(&md->table_devices_lock);
2567 if (r)
2568 return r;
2569
2570 /*
2571 * Register the holder relationship for devices added before the disk
2572 * was live.
2573 */
2574 list_for_each_entry(td, &md->table_devices, list) {
2575 r = bd_link_disk_holder(td->dm_dev.bdev, md->disk);
2576 if (r)
2577 goto out_undo_holders;
2578 }
2579
2580 r = dm_sysfs_init(md);
2581 if (r)
2582 goto out_undo_holders;
2583
2584 md->type = type;
2585 return 0;
2586
2587out_undo_holders:
2588 list_for_each_entry_continue_reverse(td, &md->table_devices, list)
2589 bd_unlink_disk_holder(td->dm_dev.bdev, md->disk);
2590 mutex_lock(&md->table_devices_lock);
2591 del_gendisk(md->disk);
2592 mutex_unlock(&md->table_devices_lock);
2593 return r;
2594}
2595
2596struct mapped_device *dm_get_md(dev_t dev)
2597{
2598 struct mapped_device *md;
2599 unsigned int minor = MINOR(dev);
2600
2601 if (MAJOR(dev) != _major || minor >= (1 << MINORBITS))
2602 return NULL;
2603
2604 spin_lock(&_minor_lock);
2605
2606 md = idr_find(&_minor_idr, minor);
2607 if (!md || md == MINOR_ALLOCED || (MINOR(disk_devt(dm_disk(md))) != minor) ||
2608 test_bit(DMF_FREEING, &md->flags) || dm_deleting_md(md)) {
2609 md = NULL;
2610 goto out;
2611 }
2612 dm_get(md);
2613out:
2614 spin_unlock(&_minor_lock);
2615
2616 return md;
2617}
2618EXPORT_SYMBOL_GPL(dm_get_md);
2619
2620void *dm_get_mdptr(struct mapped_device *md)
2621{
2622 return md->interface_ptr;
2623}
2624
2625void dm_set_mdptr(struct mapped_device *md, void *ptr)
2626{
2627 md->interface_ptr = ptr;
2628}
2629
2630void dm_get(struct mapped_device *md)
2631{
2632 atomic_inc(&md->holders);
2633 BUG_ON(test_bit(DMF_FREEING, &md->flags));
2634}
2635
2636int dm_hold(struct mapped_device *md)
2637{
2638 spin_lock(&_minor_lock);
2639 if (test_bit(DMF_FREEING, &md->flags)) {
2640 spin_unlock(&_minor_lock);
2641 return -EBUSY;
2642 }
2643 dm_get(md);
2644 spin_unlock(&_minor_lock);
2645 return 0;
2646}
2647EXPORT_SYMBOL_GPL(dm_hold);
2648
2649const char *dm_device_name(struct mapped_device *md)
2650{
2651 return md->name;
2652}
2653EXPORT_SYMBOL_GPL(dm_device_name);
2654
2655static void __dm_destroy(struct mapped_device *md, bool wait)
2656{
2657 struct dm_table *map;
2658 int srcu_idx;
2659
2660 might_sleep();
2661
2662 spin_lock(&_minor_lock);
2663 idr_replace(&_minor_idr, MINOR_ALLOCED, MINOR(disk_devt(dm_disk(md))));
2664 set_bit(DMF_FREEING, &md->flags);
2665 spin_unlock(&_minor_lock);
2666
2667 blk_mark_disk_dead(md->disk);
2668
2669 /*
2670 * Take suspend_lock so that presuspend and postsuspend methods
2671 * do not race with internal suspend.
2672 */
2673 mutex_lock(&md->suspend_lock);
2674 map = dm_get_live_table(md, &srcu_idx);
2675 if (!dm_suspended_md(md)) {
2676 dm_table_presuspend_targets(map);
2677 set_bit(DMF_SUSPENDED, &md->flags);
2678 set_bit(DMF_POST_SUSPENDING, &md->flags);
2679 dm_table_postsuspend_targets(map);
2680 }
2681 /* dm_put_live_table must be before fsleep, otherwise deadlock is possible */
2682 dm_put_live_table(md, srcu_idx);
2683 mutex_unlock(&md->suspend_lock);
2684
2685 /*
2686 * Rare, but there may be I/O requests still going to complete,
2687 * for example. Wait for all references to disappear.
2688 * No one should increment the reference count of the mapped_device,
2689 * after the mapped_device state becomes DMF_FREEING.
2690 */
2691 if (wait)
2692 while (atomic_read(&md->holders))
2693 fsleep(1000);
2694 else if (atomic_read(&md->holders))
2695 DMWARN("%s: Forcibly removing mapped_device still in use! (%d users)",
2696 dm_device_name(md), atomic_read(&md->holders));
2697
2698 dm_table_destroy(__unbind(md));
2699 free_dev(md);
2700}
2701
2702void dm_destroy(struct mapped_device *md)
2703{
2704 __dm_destroy(md, true);
2705}
2706
2707void dm_destroy_immediate(struct mapped_device *md)
2708{
2709 __dm_destroy(md, false);
2710}
2711
2712void dm_put(struct mapped_device *md)
2713{
2714 atomic_dec(&md->holders);
2715}
2716EXPORT_SYMBOL_GPL(dm_put);
2717
2718static bool dm_in_flight_bios(struct mapped_device *md)
2719{
2720 int cpu;
2721 unsigned long sum = 0;
2722
2723 for_each_possible_cpu(cpu)
2724 sum += *per_cpu_ptr(md->pending_io, cpu);
2725
2726 return sum != 0;
2727}
2728
2729static int dm_wait_for_bios_completion(struct mapped_device *md, unsigned int task_state)
2730{
2731 int r = 0;
2732 DEFINE_WAIT(wait);
2733
2734 while (true) {
2735 prepare_to_wait(&md->wait, &wait, task_state);
2736
2737 if (!dm_in_flight_bios(md))
2738 break;
2739
2740 if (signal_pending_state(task_state, current)) {
2741 r = -ERESTARTSYS;
2742 break;
2743 }
2744
2745 io_schedule();
2746 }
2747 finish_wait(&md->wait, &wait);
2748
2749 smp_rmb();
2750
2751 return r;
2752}
2753
2754static int dm_wait_for_completion(struct mapped_device *md, unsigned int task_state)
2755{
2756 int r = 0;
2757
2758 if (!queue_is_mq(md->queue))
2759 return dm_wait_for_bios_completion(md, task_state);
2760
2761 while (true) {
2762 if (!blk_mq_queue_inflight(md->queue))
2763 break;
2764
2765 if (signal_pending_state(task_state, current)) {
2766 r = -ERESTARTSYS;
2767 break;
2768 }
2769
2770 fsleep(5000);
2771 }
2772
2773 return r;
2774}
2775
2776/*
2777 * Process the deferred bios
2778 */
2779static void dm_wq_work(struct work_struct *work)
2780{
2781 struct mapped_device *md = container_of(work, struct mapped_device, work);
2782 struct bio *bio;
2783
2784 while (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) {
2785 spin_lock_irq(&md->deferred_lock);
2786 bio = bio_list_pop(&md->deferred);
2787 spin_unlock_irq(&md->deferred_lock);
2788
2789 if (!bio)
2790 break;
2791
2792 submit_bio_noacct(bio);
2793 cond_resched();
2794 }
2795}
2796
2797static void dm_queue_flush(struct mapped_device *md)
2798{
2799 clear_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags);
2800 smp_mb__after_atomic();
2801 queue_work(md->wq, &md->work);
2802}
2803
2804/*
2805 * Swap in a new table, returning the old one for the caller to destroy.
2806 */
2807struct dm_table *dm_swap_table(struct mapped_device *md, struct dm_table *table)
2808{
2809 struct dm_table *live_map = NULL, *map = ERR_PTR(-EINVAL);
2810 struct queue_limits limits;
2811 int r;
2812
2813 mutex_lock(&md->suspend_lock);
2814
2815 /* device must be suspended */
2816 if (!dm_suspended_md(md))
2817 goto out;
2818
2819 /*
2820 * If the new table has no data devices, retain the existing limits.
2821 * This helps multipath with queue_if_no_path if all paths disappear,
2822 * then new I/O is queued based on these limits, and then some paths
2823 * reappear.
2824 */
2825 if (dm_table_has_no_data_devices(table)) {
2826 live_map = dm_get_live_table_fast(md);
2827 if (live_map)
2828 limits = md->queue->limits;
2829 dm_put_live_table_fast(md);
2830 }
2831
2832 if (!live_map) {
2833 r = dm_calculate_queue_limits(table, &limits);
2834 if (r) {
2835 map = ERR_PTR(r);
2836 goto out;
2837 }
2838 }
2839
2840 map = __bind(md, table, &limits);
2841 dm_issue_global_event();
2842
2843out:
2844 mutex_unlock(&md->suspend_lock);
2845 return map;
2846}
2847
2848/*
2849 * Functions to lock and unlock any filesystem running on the
2850 * device.
2851 */
2852static int lock_fs(struct mapped_device *md)
2853{
2854 int r;
2855
2856 WARN_ON(test_bit(DMF_FROZEN, &md->flags));
2857
2858 r = bdev_freeze(md->disk->part0);
2859 if (!r)
2860 set_bit(DMF_FROZEN, &md->flags);
2861 return r;
2862}
2863
2864static void unlock_fs(struct mapped_device *md)
2865{
2866 if (!test_bit(DMF_FROZEN, &md->flags))
2867 return;
2868 bdev_thaw(md->disk->part0);
2869 clear_bit(DMF_FROZEN, &md->flags);
2870}
2871
2872/*
2873 * @suspend_flags: DM_SUSPEND_LOCKFS_FLAG and/or DM_SUSPEND_NOFLUSH_FLAG
2874 * @task_state: e.g. TASK_INTERRUPTIBLE or TASK_UNINTERRUPTIBLE
2875 * @dmf_suspended_flag: DMF_SUSPENDED or DMF_SUSPENDED_INTERNALLY
2876 *
2877 * If __dm_suspend returns 0, the device is completely quiescent
2878 * now. There is no request-processing activity. All new requests
2879 * are being added to md->deferred list.
2880 */
2881static int __dm_suspend(struct mapped_device *md, struct dm_table *map,
2882 unsigned int suspend_flags, unsigned int task_state,
2883 int dmf_suspended_flag)
2884{
2885 bool do_lockfs = suspend_flags & DM_SUSPEND_LOCKFS_FLAG;
2886 bool noflush = suspend_flags & DM_SUSPEND_NOFLUSH_FLAG;
2887 int r;
2888
2889 lockdep_assert_held(&md->suspend_lock);
2890
2891 /*
2892 * DMF_NOFLUSH_SUSPENDING must be set before presuspend.
2893 * This flag is cleared before dm_suspend returns.
2894 */
2895 if (noflush)
2896 set_bit(DMF_NOFLUSH_SUSPENDING, &md->flags);
2897 else
2898 DMDEBUG("%s: suspending with flush", dm_device_name(md));
2899
2900 /*
2901 * This gets reverted if there's an error later and the targets
2902 * provide the .presuspend_undo hook.
2903 */
2904 dm_table_presuspend_targets(map);
2905
2906 /*
2907 * Flush I/O to the device.
2908 * Any I/O submitted after lock_fs() may not be flushed.
2909 * noflush takes precedence over do_lockfs.
2910 * (lock_fs() flushes I/Os and waits for them to complete.)
2911 */
2912 if (!noflush && do_lockfs) {
2913 r = lock_fs(md);
2914 if (r) {
2915 dm_table_presuspend_undo_targets(map);
2916 return r;
2917 }
2918 }
2919
2920 /*
2921 * Here we must make sure that no processes are submitting requests
2922 * to target drivers i.e. no one may be executing
2923 * dm_split_and_process_bio from dm_submit_bio.
2924 *
2925 * To get all processes out of dm_split_and_process_bio in dm_submit_bio,
2926 * we take the write lock. To prevent any process from reentering
2927 * dm_split_and_process_bio from dm_submit_bio and quiesce the thread
2928 * (dm_wq_work), we set DMF_BLOCK_IO_FOR_SUSPEND and call
2929 * flush_workqueue(md->wq).
2930 */
2931 set_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags);
2932 if (map)
2933 synchronize_srcu(&md->io_barrier);
2934
2935 /*
2936 * Stop md->queue before flushing md->wq in case request-based
2937 * dm defers requests to md->wq from md->queue.
2938 */
2939 if (dm_request_based(md))
2940 dm_stop_queue(md->queue);
2941
2942 flush_workqueue(md->wq);
2943
2944 /*
2945 * At this point no more requests are entering target request routines.
2946 * We call dm_wait_for_completion to wait for all existing requests
2947 * to finish.
2948 */
2949 r = dm_wait_for_completion(md, task_state);
2950 if (!r)
2951 set_bit(dmf_suspended_flag, &md->flags);
2952
2953 if (noflush)
2954 clear_bit(DMF_NOFLUSH_SUSPENDING, &md->flags);
2955 if (map)
2956 synchronize_srcu(&md->io_barrier);
2957
2958 /* were we interrupted ? */
2959 if (r < 0) {
2960 dm_queue_flush(md);
2961
2962 if (dm_request_based(md))
2963 dm_start_queue(md->queue);
2964
2965 unlock_fs(md);
2966 dm_table_presuspend_undo_targets(map);
2967 /* pushback list is already flushed, so skip flush */
2968 }
2969
2970 return r;
2971}
2972
2973/*
2974 * We need to be able to change a mapping table under a mounted
2975 * filesystem. For example we might want to move some data in
2976 * the background. Before the table can be swapped with
2977 * dm_bind_table, dm_suspend must be called to flush any in
2978 * flight bios and ensure that any further io gets deferred.
2979 */
2980/*
2981 * Suspend mechanism in request-based dm.
2982 *
2983 * 1. Flush all I/Os by lock_fs() if needed.
2984 * 2. Stop dispatching any I/O by stopping the request_queue.
2985 * 3. Wait for all in-flight I/Os to be completed or requeued.
2986 *
2987 * To abort suspend, start the request_queue.
2988 */
2989int dm_suspend(struct mapped_device *md, unsigned int suspend_flags)
2990{
2991 struct dm_table *map = NULL;
2992 int r = 0;
2993
2994retry:
2995 mutex_lock_nested(&md->suspend_lock, SINGLE_DEPTH_NESTING);
2996
2997 if (dm_suspended_md(md)) {
2998 r = -EINVAL;
2999 goto out_unlock;
3000 }
3001
3002 if (dm_suspended_internally_md(md)) {
3003 /* already internally suspended, wait for internal resume */
3004 mutex_unlock(&md->suspend_lock);
3005 r = wait_on_bit(&md->flags, DMF_SUSPENDED_INTERNALLY, TASK_INTERRUPTIBLE);
3006 if (r)
3007 return r;
3008 goto retry;
3009 }
3010
3011 map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock));
3012 if (!map) {
3013 /* avoid deadlock with fs/namespace.c:do_mount() */
3014 suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG;
3015 }
3016
3017 r = __dm_suspend(md, map, suspend_flags, TASK_INTERRUPTIBLE, DMF_SUSPENDED);
3018 if (r)
3019 goto out_unlock;
3020
3021 set_bit(DMF_POST_SUSPENDING, &md->flags);
3022 dm_table_postsuspend_targets(map);
3023 clear_bit(DMF_POST_SUSPENDING, &md->flags);
3024
3025out_unlock:
3026 mutex_unlock(&md->suspend_lock);
3027 return r;
3028}
3029
3030static int __dm_resume(struct mapped_device *md, struct dm_table *map)
3031{
3032 if (map) {
3033 int r = dm_table_resume_targets(map);
3034
3035 if (r)
3036 return r;
3037 }
3038
3039 dm_queue_flush(md);
3040
3041 /*
3042 * Flushing deferred I/Os must be done after targets are resumed
3043 * so that mapping of targets can work correctly.
3044 * Request-based dm is queueing the deferred I/Os in its request_queue.
3045 */
3046 if (dm_request_based(md))
3047 dm_start_queue(md->queue);
3048
3049 unlock_fs(md);
3050
3051 return 0;
3052}
3053
3054int dm_resume(struct mapped_device *md)
3055{
3056 int r;
3057 struct dm_table *map = NULL;
3058
3059retry:
3060 r = -EINVAL;
3061 mutex_lock_nested(&md->suspend_lock, SINGLE_DEPTH_NESTING);
3062
3063 if (!dm_suspended_md(md))
3064 goto out;
3065
3066 if (dm_suspended_internally_md(md)) {
3067 /* already internally suspended, wait for internal resume */
3068 mutex_unlock(&md->suspend_lock);
3069 r = wait_on_bit(&md->flags, DMF_SUSPENDED_INTERNALLY, TASK_INTERRUPTIBLE);
3070 if (r)
3071 return r;
3072 goto retry;
3073 }
3074
3075 map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock));
3076 if (!map || !dm_table_get_size(map))
3077 goto out;
3078
3079 r = __dm_resume(md, map);
3080 if (r)
3081 goto out;
3082
3083 clear_bit(DMF_SUSPENDED, &md->flags);
3084out:
3085 mutex_unlock(&md->suspend_lock);
3086
3087 return r;
3088}
3089
3090/*
3091 * Internal suspend/resume works like userspace-driven suspend. It waits
3092 * until all bios finish and prevents issuing new bios to the target drivers.
3093 * It may be used only from the kernel.
3094 */
3095
3096static void __dm_internal_suspend(struct mapped_device *md, unsigned int suspend_flags)
3097{
3098 struct dm_table *map = NULL;
3099
3100 lockdep_assert_held(&md->suspend_lock);
3101
3102 if (md->internal_suspend_count++)
3103 return; /* nested internal suspend */
3104
3105 if (dm_suspended_md(md)) {
3106 set_bit(DMF_SUSPENDED_INTERNALLY, &md->flags);
3107 return; /* nest suspend */
3108 }
3109
3110 map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock));
3111
3112 /*
3113 * Using TASK_UNINTERRUPTIBLE because only NOFLUSH internal suspend is
3114 * supported. Properly supporting a TASK_INTERRUPTIBLE internal suspend
3115 * would require changing .presuspend to return an error -- avoid this
3116 * until there is a need for more elaborate variants of internal suspend.
3117 */
3118 (void) __dm_suspend(md, map, suspend_flags, TASK_UNINTERRUPTIBLE,
3119 DMF_SUSPENDED_INTERNALLY);
3120
3121 set_bit(DMF_POST_SUSPENDING, &md->flags);
3122 dm_table_postsuspend_targets(map);
3123 clear_bit(DMF_POST_SUSPENDING, &md->flags);
3124}
3125
3126static void __dm_internal_resume(struct mapped_device *md)
3127{
3128 int r;
3129 struct dm_table *map;
3130
3131 BUG_ON(!md->internal_suspend_count);
3132
3133 if (--md->internal_suspend_count)
3134 return; /* resume from nested internal suspend */
3135
3136 if (dm_suspended_md(md))
3137 goto done; /* resume from nested suspend */
3138
3139 map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock));
3140 r = __dm_resume(md, map);
3141 if (r) {
3142 /*
3143 * If a preresume method of some target failed, we are in a
3144 * tricky situation. We can't return an error to the caller. We
3145 * can't fake success because then the "resume" and
3146 * "postsuspend" methods would not be paired correctly, and it
3147 * would break various targets, for example it would cause list
3148 * corruption in the "origin" target.
3149 *
3150 * So, we fake normal suspend here, to make sure that the
3151 * "resume" and "postsuspend" methods will be paired correctly.
3152 */
3153 DMERR("Preresume method failed: %d", r);
3154 set_bit(DMF_SUSPENDED, &md->flags);
3155 }
3156done:
3157 clear_bit(DMF_SUSPENDED_INTERNALLY, &md->flags);
3158 smp_mb__after_atomic();
3159 wake_up_bit(&md->flags, DMF_SUSPENDED_INTERNALLY);
3160}
3161
3162void dm_internal_suspend_noflush(struct mapped_device *md)
3163{
3164 mutex_lock(&md->suspend_lock);
3165 __dm_internal_suspend(md, DM_SUSPEND_NOFLUSH_FLAG);
3166 mutex_unlock(&md->suspend_lock);
3167}
3168EXPORT_SYMBOL_GPL(dm_internal_suspend_noflush);
3169
3170void dm_internal_resume(struct mapped_device *md)
3171{
3172 mutex_lock(&md->suspend_lock);
3173 __dm_internal_resume(md);
3174 mutex_unlock(&md->suspend_lock);
3175}
3176EXPORT_SYMBOL_GPL(dm_internal_resume);
3177
3178/*
3179 * Fast variants of internal suspend/resume hold md->suspend_lock,
3180 * which prevents interaction with userspace-driven suspend.
3181 */
3182
3183void dm_internal_suspend_fast(struct mapped_device *md)
3184{
3185 mutex_lock(&md->suspend_lock);
3186 if (dm_suspended_md(md) || dm_suspended_internally_md(md))
3187 return;
3188
3189 set_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags);
3190 synchronize_srcu(&md->io_barrier);
3191 flush_workqueue(md->wq);
3192 dm_wait_for_completion(md, TASK_UNINTERRUPTIBLE);
3193}
3194EXPORT_SYMBOL_GPL(dm_internal_suspend_fast);
3195
3196void dm_internal_resume_fast(struct mapped_device *md)
3197{
3198 if (dm_suspended_md(md) || dm_suspended_internally_md(md))
3199 goto done;
3200
3201 dm_queue_flush(md);
3202
3203done:
3204 mutex_unlock(&md->suspend_lock);
3205}
3206EXPORT_SYMBOL_GPL(dm_internal_resume_fast);
3207
3208/*
3209 *---------------------------------------------------------------
3210 * Event notification.
3211 *---------------------------------------------------------------
3212 */
3213int dm_kobject_uevent(struct mapped_device *md, enum kobject_action action,
3214 unsigned int cookie, bool need_resize_uevent)
3215{
3216 int r;
3217 unsigned int noio_flag;
3218 char udev_cookie[DM_COOKIE_LENGTH];
3219 char *envp[3] = { NULL, NULL, NULL };
3220 char **envpp = envp;
3221 if (cookie) {
3222 snprintf(udev_cookie, DM_COOKIE_LENGTH, "%s=%u",
3223 DM_COOKIE_ENV_VAR_NAME, cookie);
3224 *envpp++ = udev_cookie;
3225 }
3226 if (need_resize_uevent) {
3227 *envpp++ = "RESIZE=1";
3228 }
3229
3230 noio_flag = memalloc_noio_save();
3231
3232 r = kobject_uevent_env(&disk_to_dev(md->disk)->kobj, action, envp);
3233
3234 memalloc_noio_restore(noio_flag);
3235
3236 return r;
3237}
3238
3239uint32_t dm_next_uevent_seq(struct mapped_device *md)
3240{
3241 return atomic_add_return(1, &md->uevent_seq);
3242}
3243
3244uint32_t dm_get_event_nr(struct mapped_device *md)
3245{
3246 return atomic_read(&md->event_nr);
3247}
3248
3249int dm_wait_event(struct mapped_device *md, int event_nr)
3250{
3251 return wait_event_interruptible(md->eventq,
3252 (event_nr != atomic_read(&md->event_nr)));
3253}
3254
3255void dm_uevent_add(struct mapped_device *md, struct list_head *elist)
3256{
3257 unsigned long flags;
3258
3259 spin_lock_irqsave(&md->uevent_lock, flags);
3260 list_add(elist, &md->uevent_list);
3261 spin_unlock_irqrestore(&md->uevent_lock, flags);
3262}
3263
3264/*
3265 * The gendisk is only valid as long as you have a reference
3266 * count on 'md'.
3267 */
3268struct gendisk *dm_disk(struct mapped_device *md)
3269{
3270 return md->disk;
3271}
3272EXPORT_SYMBOL_GPL(dm_disk);
3273
3274struct kobject *dm_kobject(struct mapped_device *md)
3275{
3276 return &md->kobj_holder.kobj;
3277}
3278
3279struct mapped_device *dm_get_from_kobject(struct kobject *kobj)
3280{
3281 struct mapped_device *md;
3282
3283 md = container_of(kobj, struct mapped_device, kobj_holder.kobj);
3284
3285 spin_lock(&_minor_lock);
3286 if (test_bit(DMF_FREEING, &md->flags) || dm_deleting_md(md)) {
3287 md = NULL;
3288 goto out;
3289 }
3290 dm_get(md);
3291out:
3292 spin_unlock(&_minor_lock);
3293
3294 return md;
3295}
3296
3297int dm_suspended_md(struct mapped_device *md)
3298{
3299 return test_bit(DMF_SUSPENDED, &md->flags);
3300}
3301
3302static int dm_post_suspending_md(struct mapped_device *md)
3303{
3304 return test_bit(DMF_POST_SUSPENDING, &md->flags);
3305}
3306
3307int dm_suspended_internally_md(struct mapped_device *md)
3308{
3309 return test_bit(DMF_SUSPENDED_INTERNALLY, &md->flags);
3310}
3311
3312int dm_test_deferred_remove_flag(struct mapped_device *md)
3313{
3314 return test_bit(DMF_DEFERRED_REMOVE, &md->flags);
3315}
3316
3317int dm_suspended(struct dm_target *ti)
3318{
3319 return dm_suspended_md(ti->table->md);
3320}
3321EXPORT_SYMBOL_GPL(dm_suspended);
3322
3323int dm_post_suspending(struct dm_target *ti)
3324{
3325 return dm_post_suspending_md(ti->table->md);
3326}
3327EXPORT_SYMBOL_GPL(dm_post_suspending);
3328
3329int dm_noflush_suspending(struct dm_target *ti)
3330{
3331 return __noflush_suspending(ti->table->md);
3332}
3333EXPORT_SYMBOL_GPL(dm_noflush_suspending);
3334
3335void dm_free_md_mempools(struct dm_md_mempools *pools)
3336{
3337 if (!pools)
3338 return;
3339
3340 bioset_exit(&pools->bs);
3341 bioset_exit(&pools->io_bs);
3342
3343 kfree(pools);
3344}
3345
3346struct dm_blkdev_id {
3347 u8 *id;
3348 enum blk_unique_id type;
3349};
3350
3351static int __dm_get_unique_id(struct dm_target *ti, struct dm_dev *dev,
3352 sector_t start, sector_t len, void *data)
3353{
3354 struct dm_blkdev_id *dm_id = data;
3355 const struct block_device_operations *fops = dev->bdev->bd_disk->fops;
3356
3357 if (!fops->get_unique_id)
3358 return 0;
3359
3360 return fops->get_unique_id(dev->bdev->bd_disk, dm_id->id, dm_id->type);
3361}
3362
3363/*
3364 * Allow access to get_unique_id() for the first device returning a
3365 * non-zero result. Reasonable use expects all devices to have the
3366 * same unique id.
3367 */
3368static int dm_blk_get_unique_id(struct gendisk *disk, u8 *id,
3369 enum blk_unique_id type)
3370{
3371 struct mapped_device *md = disk->private_data;
3372 struct dm_table *table;
3373 struct dm_target *ti;
3374 int ret = 0, srcu_idx;
3375
3376 struct dm_blkdev_id dm_id = {
3377 .id = id,
3378 .type = type,
3379 };
3380
3381 table = dm_get_live_table(md, &srcu_idx);
3382 if (!table || !dm_table_get_size(table))
3383 goto out;
3384
3385 /* We only support devices that have a single target */
3386 if (table->num_targets != 1)
3387 goto out;
3388 ti = dm_table_get_target(table, 0);
3389
3390 if (!ti->type->iterate_devices)
3391 goto out;
3392
3393 ret = ti->type->iterate_devices(ti, __dm_get_unique_id, &dm_id);
3394out:
3395 dm_put_live_table(md, srcu_idx);
3396 return ret;
3397}
3398
3399struct dm_pr {
3400 u64 old_key;
3401 u64 new_key;
3402 u32 flags;
3403 bool abort;
3404 bool fail_early;
3405 int ret;
3406 enum pr_type type;
3407 struct pr_keys *read_keys;
3408 struct pr_held_reservation *rsv;
3409};
3410
3411static int dm_call_pr(struct block_device *bdev, iterate_devices_callout_fn fn,
3412 struct dm_pr *pr)
3413{
3414 struct mapped_device *md = bdev->bd_disk->private_data;
3415 struct dm_table *table;
3416 struct dm_target *ti;
3417 int ret = -ENOTTY, srcu_idx;
3418
3419 table = dm_get_live_table(md, &srcu_idx);
3420 if (!table || !dm_table_get_size(table))
3421 goto out;
3422
3423 /* We only support devices that have a single target */
3424 if (table->num_targets != 1)
3425 goto out;
3426 ti = dm_table_get_target(table, 0);
3427
3428 if (dm_suspended_md(md)) {
3429 ret = -EAGAIN;
3430 goto out;
3431 }
3432
3433 ret = -EINVAL;
3434 if (!ti->type->iterate_devices)
3435 goto out;
3436
3437 ti->type->iterate_devices(ti, fn, pr);
3438 ret = 0;
3439out:
3440 dm_put_live_table(md, srcu_idx);
3441 return ret;
3442}
3443
3444/*
3445 * For register / unregister we need to manually call out to every path.
3446 */
3447static int __dm_pr_register(struct dm_target *ti, struct dm_dev *dev,
3448 sector_t start, sector_t len, void *data)
3449{
3450 struct dm_pr *pr = data;
3451 const struct pr_ops *ops = dev->bdev->bd_disk->fops->pr_ops;
3452 int ret;
3453
3454 if (!ops || !ops->pr_register) {
3455 pr->ret = -EOPNOTSUPP;
3456 return -1;
3457 }
3458
3459 ret = ops->pr_register(dev->bdev, pr->old_key, pr->new_key, pr->flags);
3460 if (!ret)
3461 return 0;
3462
3463 if (!pr->ret)
3464 pr->ret = ret;
3465
3466 if (pr->fail_early)
3467 return -1;
3468
3469 return 0;
3470}
3471
3472static int dm_pr_register(struct block_device *bdev, u64 old_key, u64 new_key,
3473 u32 flags)
3474{
3475 struct dm_pr pr = {
3476 .old_key = old_key,
3477 .new_key = new_key,
3478 .flags = flags,
3479 .fail_early = true,
3480 .ret = 0,
3481 };
3482 int ret;
3483
3484 ret = dm_call_pr(bdev, __dm_pr_register, &pr);
3485 if (ret) {
3486 /* Didn't even get to register a path */
3487 return ret;
3488 }
3489
3490 if (!pr.ret)
3491 return 0;
3492 ret = pr.ret;
3493
3494 if (!new_key)
3495 return ret;
3496
3497 /* unregister all paths if we failed to register any path */
3498 pr.old_key = new_key;
3499 pr.new_key = 0;
3500 pr.flags = 0;
3501 pr.fail_early = false;
3502 (void) dm_call_pr(bdev, __dm_pr_register, &pr);
3503 return ret;
3504}
3505
3506
3507static int __dm_pr_reserve(struct dm_target *ti, struct dm_dev *dev,
3508 sector_t start, sector_t len, void *data)
3509{
3510 struct dm_pr *pr = data;
3511 const struct pr_ops *ops = dev->bdev->bd_disk->fops->pr_ops;
3512
3513 if (!ops || !ops->pr_reserve) {
3514 pr->ret = -EOPNOTSUPP;
3515 return -1;
3516 }
3517
3518 pr->ret = ops->pr_reserve(dev->bdev, pr->old_key, pr->type, pr->flags);
3519 if (!pr->ret)
3520 return -1;
3521
3522 return 0;
3523}
3524
3525static int dm_pr_reserve(struct block_device *bdev, u64 key, enum pr_type type,
3526 u32 flags)
3527{
3528 struct dm_pr pr = {
3529 .old_key = key,
3530 .flags = flags,
3531 .type = type,
3532 .fail_early = false,
3533 .ret = 0,
3534 };
3535 int ret;
3536
3537 ret = dm_call_pr(bdev, __dm_pr_reserve, &pr);
3538 if (ret)
3539 return ret;
3540
3541 return pr.ret;
3542}
3543
3544/*
3545 * If there is a non-All Registrants type of reservation, the release must be
3546 * sent down the holding path. For the cases where there is no reservation or
3547 * the path is not the holder the device will also return success, so we must
3548 * try each path to make sure we got the correct path.
3549 */
3550static int __dm_pr_release(struct dm_target *ti, struct dm_dev *dev,
3551 sector_t start, sector_t len, void *data)
3552{
3553 struct dm_pr *pr = data;
3554 const struct pr_ops *ops = dev->bdev->bd_disk->fops->pr_ops;
3555
3556 if (!ops || !ops->pr_release) {
3557 pr->ret = -EOPNOTSUPP;
3558 return -1;
3559 }
3560
3561 pr->ret = ops->pr_release(dev->bdev, pr->old_key, pr->type);
3562 if (pr->ret)
3563 return -1;
3564
3565 return 0;
3566}
3567
3568static int dm_pr_release(struct block_device *bdev, u64 key, enum pr_type type)
3569{
3570 struct dm_pr pr = {
3571 .old_key = key,
3572 .type = type,
3573 .fail_early = false,
3574 };
3575 int ret;
3576
3577 ret = dm_call_pr(bdev, __dm_pr_release, &pr);
3578 if (ret)
3579 return ret;
3580
3581 return pr.ret;
3582}
3583
3584static int __dm_pr_preempt(struct dm_target *ti, struct dm_dev *dev,
3585 sector_t start, sector_t len, void *data)
3586{
3587 struct dm_pr *pr = data;
3588 const struct pr_ops *ops = dev->bdev->bd_disk->fops->pr_ops;
3589
3590 if (!ops || !ops->pr_preempt) {
3591 pr->ret = -EOPNOTSUPP;
3592 return -1;
3593 }
3594
3595 pr->ret = ops->pr_preempt(dev->bdev, pr->old_key, pr->new_key, pr->type,
3596 pr->abort);
3597 if (!pr->ret)
3598 return -1;
3599
3600 return 0;
3601}
3602
3603static int dm_pr_preempt(struct block_device *bdev, u64 old_key, u64 new_key,
3604 enum pr_type type, bool abort)
3605{
3606 struct dm_pr pr = {
3607 .new_key = new_key,
3608 .old_key = old_key,
3609 .type = type,
3610 .fail_early = false,
3611 };
3612 int ret;
3613
3614 ret = dm_call_pr(bdev, __dm_pr_preempt, &pr);
3615 if (ret)
3616 return ret;
3617
3618 return pr.ret;
3619}
3620
3621static int dm_pr_clear(struct block_device *bdev, u64 key)
3622{
3623 struct mapped_device *md = bdev->bd_disk->private_data;
3624 const struct pr_ops *ops;
3625 int r, srcu_idx;
3626
3627 r = dm_prepare_ioctl(md, &srcu_idx, &bdev);
3628 if (r < 0)
3629 goto out;
3630
3631 ops = bdev->bd_disk->fops->pr_ops;
3632 if (ops && ops->pr_clear)
3633 r = ops->pr_clear(bdev, key);
3634 else
3635 r = -EOPNOTSUPP;
3636out:
3637 dm_unprepare_ioctl(md, srcu_idx);
3638 return r;
3639}
3640
3641static int __dm_pr_read_keys(struct dm_target *ti, struct dm_dev *dev,
3642 sector_t start, sector_t len, void *data)
3643{
3644 struct dm_pr *pr = data;
3645 const struct pr_ops *ops = dev->bdev->bd_disk->fops->pr_ops;
3646
3647 if (!ops || !ops->pr_read_keys) {
3648 pr->ret = -EOPNOTSUPP;
3649 return -1;
3650 }
3651
3652 pr->ret = ops->pr_read_keys(dev->bdev, pr->read_keys);
3653 if (!pr->ret)
3654 return -1;
3655
3656 return 0;
3657}
3658
3659static int dm_pr_read_keys(struct block_device *bdev, struct pr_keys *keys)
3660{
3661 struct dm_pr pr = {
3662 .read_keys = keys,
3663 };
3664 int ret;
3665
3666 ret = dm_call_pr(bdev, __dm_pr_read_keys, &pr);
3667 if (ret)
3668 return ret;
3669
3670 return pr.ret;
3671}
3672
3673static int __dm_pr_read_reservation(struct dm_target *ti, struct dm_dev *dev,
3674 sector_t start, sector_t len, void *data)
3675{
3676 struct dm_pr *pr = data;
3677 const struct pr_ops *ops = dev->bdev->bd_disk->fops->pr_ops;
3678
3679 if (!ops || !ops->pr_read_reservation) {
3680 pr->ret = -EOPNOTSUPP;
3681 return -1;
3682 }
3683
3684 pr->ret = ops->pr_read_reservation(dev->bdev, pr->rsv);
3685 if (!pr->ret)
3686 return -1;
3687
3688 return 0;
3689}
3690
3691static int dm_pr_read_reservation(struct block_device *bdev,
3692 struct pr_held_reservation *rsv)
3693{
3694 struct dm_pr pr = {
3695 .rsv = rsv,
3696 };
3697 int ret;
3698
3699 ret = dm_call_pr(bdev, __dm_pr_read_reservation, &pr);
3700 if (ret)
3701 return ret;
3702
3703 return pr.ret;
3704}
3705
3706static const struct pr_ops dm_pr_ops = {
3707 .pr_register = dm_pr_register,
3708 .pr_reserve = dm_pr_reserve,
3709 .pr_release = dm_pr_release,
3710 .pr_preempt = dm_pr_preempt,
3711 .pr_clear = dm_pr_clear,
3712 .pr_read_keys = dm_pr_read_keys,
3713 .pr_read_reservation = dm_pr_read_reservation,
3714};
3715
3716static const struct block_device_operations dm_blk_dops = {
3717 .submit_bio = dm_submit_bio,
3718 .poll_bio = dm_poll_bio,
3719 .open = dm_blk_open,
3720 .release = dm_blk_close,
3721 .ioctl = dm_blk_ioctl,
3722 .getgeo = dm_blk_getgeo,
3723 .report_zones = dm_blk_report_zones,
3724 .get_unique_id = dm_blk_get_unique_id,
3725 .pr_ops = &dm_pr_ops,
3726 .owner = THIS_MODULE
3727};
3728
3729static const struct block_device_operations dm_rq_blk_dops = {
3730 .open = dm_blk_open,
3731 .release = dm_blk_close,
3732 .ioctl = dm_blk_ioctl,
3733 .getgeo = dm_blk_getgeo,
3734 .get_unique_id = dm_blk_get_unique_id,
3735 .pr_ops = &dm_pr_ops,
3736 .owner = THIS_MODULE
3737};
3738
3739static const struct dax_operations dm_dax_ops = {
3740 .direct_access = dm_dax_direct_access,
3741 .zero_page_range = dm_dax_zero_page_range,
3742 .recovery_write = dm_dax_recovery_write,
3743};
3744
3745/*
3746 * module hooks
3747 */
3748module_init(dm_init);
3749module_exit(dm_exit);
3750
3751module_param(major, uint, 0);
3752MODULE_PARM_DESC(major, "The major number of the device mapper");
3753
3754module_param(reserved_bio_based_ios, uint, 0644);
3755MODULE_PARM_DESC(reserved_bio_based_ios, "Reserved IOs in bio-based mempools");
3756
3757module_param(dm_numa_node, int, 0644);
3758MODULE_PARM_DESC(dm_numa_node, "NUMA node for DM device memory allocations");
3759
3760module_param(swap_bios, int, 0644);
3761MODULE_PARM_DESC(swap_bios, "Maximum allowed inflight swap IOs");
3762
3763MODULE_DESCRIPTION(DM_NAME " driver");
3764MODULE_AUTHOR("Joe Thornber <dm-devel@lists.linux.dev>");
3765MODULE_LICENSE("GPL");