blob: 6e741f19a732e6156b0e1fd834bc9f2dfbc08f68 [file] [log] [blame]
rjw1f884582022-01-06 17:20:42 +08001/*
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-core.h"
9#include "dm-rq.h"
10#include "dm-uevent.h"
11
12#include <linux/init.h>
13#include <linux/module.h>
14#include <linux/mutex.h>
15#include <linux/sched/mm.h>
16#include <linux/sched/signal.h>
17#include <linux/blkpg.h>
18#include <linux/bio.h>
19#include <linux/mempool.h>
20#include <linux/dax.h>
21#include <linux/slab.h>
22#include <linux/idr.h>
23#include <linux/uio.h>
24#include <linux/hdreg.h>
25#include <linux/delay.h>
26#include <linux/wait.h>
27#include <linux/pr.h>
28
29#define DM_MSG_PREFIX "core"
30
31/*
32 * Cookies are numeric values sent with CHANGE and REMOVE
33 * uevents while resuming, removing or renaming the device.
34 */
35#define DM_COOKIE_ENV_VAR_NAME "DM_COOKIE"
36#define DM_COOKIE_LENGTH 24
37
38static const char *_name = DM_NAME;
39
40static unsigned int major = 0;
41static unsigned int _major = 0;
42
43static DEFINE_IDR(_minor_idr);
44
45static DEFINE_SPINLOCK(_minor_lock);
46
47static void do_deferred_remove(struct work_struct *w);
48
49static DECLARE_WORK(deferred_remove_work, do_deferred_remove);
50
51static struct workqueue_struct *deferred_remove_workqueue;
52
53atomic_t dm_global_event_nr = ATOMIC_INIT(0);
54DECLARE_WAIT_QUEUE_HEAD(dm_global_eventq);
55
56void dm_issue_global_event(void)
57{
58 atomic_inc(&dm_global_event_nr);
59 wake_up(&dm_global_eventq);
60}
61
62/*
63 * One of these is allocated per bio.
64 */
65struct dm_io {
66 struct mapped_device *md;
67 blk_status_t status;
68 atomic_t io_count;
69 struct bio *bio;
70 unsigned long start_time;
71 spinlock_t endio_lock;
72 struct dm_stats_aux stats_aux;
73};
74
75#define MINOR_ALLOCED ((void *)-1)
76
77/*
78 * Bits for the md->flags field.
79 */
80#define DMF_BLOCK_IO_FOR_SUSPEND 0
81#define DMF_SUSPENDED 1
82#define DMF_FROZEN 2
83#define DMF_FREEING 3
84#define DMF_DELETING 4
85#define DMF_NOFLUSH_SUSPENDING 5
86#define DMF_DEFERRED_REMOVE 6
87#define DMF_SUSPENDED_INTERNALLY 7
88
89#define DM_NUMA_NODE NUMA_NO_NODE
90static int dm_numa_node = DM_NUMA_NODE;
91
92/*
93 * For mempools pre-allocation at the table loading time.
94 */
95struct dm_md_mempools {
96 mempool_t *io_pool;
97 struct bio_set *bs;
98};
99
100struct table_device {
101 struct list_head list;
102 atomic_t count;
103 struct dm_dev dm_dev;
104};
105
106static struct kmem_cache *_io_cache;
107static struct kmem_cache *_rq_tio_cache;
108static struct kmem_cache *_rq_cache;
109
110/*
111 * Bio-based DM's mempools' reserved IOs set by the user.
112 */
113#define RESERVED_BIO_BASED_IOS 16
114static unsigned reserved_bio_based_ios = RESERVED_BIO_BASED_IOS;
115
116static int __dm_get_module_param_int(int *module_param, int min, int max)
117{
118 int param = ACCESS_ONCE(*module_param);
119 int modified_param = 0;
120 bool modified = true;
121
122 if (param < min)
123 modified_param = min;
124 else if (param > max)
125 modified_param = max;
126 else
127 modified = false;
128
129 if (modified) {
130 (void)cmpxchg(module_param, param, modified_param);
131 param = modified_param;
132 }
133
134 return param;
135}
136
137unsigned __dm_get_module_param(unsigned *module_param,
138 unsigned def, unsigned max)
139{
140 unsigned param = ACCESS_ONCE(*module_param);
141 unsigned modified_param = 0;
142
143 if (!param)
144 modified_param = def;
145 else if (param > max)
146 modified_param = max;
147
148 if (modified_param) {
149 (void)cmpxchg(module_param, param, modified_param);
150 param = modified_param;
151 }
152
153 return param;
154}
155
156unsigned dm_get_reserved_bio_based_ios(void)
157{
158 return __dm_get_module_param(&reserved_bio_based_ios,
159 RESERVED_BIO_BASED_IOS, DM_RESERVED_MAX_IOS);
160}
161EXPORT_SYMBOL_GPL(dm_get_reserved_bio_based_ios);
162
163static unsigned dm_get_numa_node(void)
164{
165 return __dm_get_module_param_int(&dm_numa_node,
166 DM_NUMA_NODE, num_online_nodes() - 1);
167}
168
169static int __init local_init(void)
170{
171 int r = -ENOMEM;
172
173 /* allocate a slab for the dm_ios */
174 _io_cache = KMEM_CACHE(dm_io, 0);
175 if (!_io_cache)
176 return r;
177
178 _rq_tio_cache = KMEM_CACHE(dm_rq_target_io, 0);
179 if (!_rq_tio_cache)
180 goto out_free_io_cache;
181
182 _rq_cache = kmem_cache_create("dm_old_clone_request", sizeof(struct request),
183 __alignof__(struct request), 0, NULL);
184 if (!_rq_cache)
185 goto out_free_rq_tio_cache;
186
187 r = dm_uevent_init();
188 if (r)
189 goto out_free_rq_cache;
190
191 deferred_remove_workqueue = alloc_workqueue("kdmremove", WQ_UNBOUND, 1);
192 if (!deferred_remove_workqueue) {
193 r = -ENOMEM;
194 goto out_uevent_exit;
195 }
196
197 _major = major;
198 r = register_blkdev(_major, _name);
199 if (r < 0)
200 goto out_free_workqueue;
201
202 if (!_major)
203 _major = r;
204
205 return 0;
206
207out_free_workqueue:
208 destroy_workqueue(deferred_remove_workqueue);
209out_uevent_exit:
210 dm_uevent_exit();
211out_free_rq_cache:
212 kmem_cache_destroy(_rq_cache);
213out_free_rq_tio_cache:
214 kmem_cache_destroy(_rq_tio_cache);
215out_free_io_cache:
216 kmem_cache_destroy(_io_cache);
217
218 return r;
219}
220
221static void local_exit(void)
222{
223 flush_scheduled_work();
224 destroy_workqueue(deferred_remove_workqueue);
225
226 kmem_cache_destroy(_rq_cache);
227 kmem_cache_destroy(_rq_tio_cache);
228 kmem_cache_destroy(_io_cache);
229 unregister_blkdev(_major, _name);
230 dm_uevent_exit();
231
232 _major = 0;
233
234 DMINFO("cleaned up");
235}
236
237static int (*_inits[])(void) __initdata = {
238 local_init,
239 dm_target_init,
240 dm_linear_init,
241 dm_stripe_init,
242 dm_io_init,
243 dm_kcopyd_init,
244 dm_interface_init,
245 dm_statistics_init,
246};
247
248static void (*_exits[])(void) = {
249 local_exit,
250 dm_target_exit,
251 dm_linear_exit,
252 dm_stripe_exit,
253 dm_io_exit,
254 dm_kcopyd_exit,
255 dm_interface_exit,
256 dm_statistics_exit,
257};
258
259static int __init dm_init(void)
260{
261 const int count = ARRAY_SIZE(_inits);
262
263 int r, i;
264
265 for (i = 0; i < count; i++) {
266 r = _inits[i]();
267 if (r)
268 goto bad;
269 }
270
271 return 0;
272
273 bad:
274 while (i--)
275 _exits[i]();
276
277 return r;
278}
279
280static void __exit dm_exit(void)
281{
282 int i = ARRAY_SIZE(_exits);
283
284 while (i--)
285 _exits[i]();
286
287 /*
288 * Should be empty by this point.
289 */
290 idr_destroy(&_minor_idr);
291}
292
293/*
294 * Block device functions
295 */
296int dm_deleting_md(struct mapped_device *md)
297{
298 return test_bit(DMF_DELETING, &md->flags);
299}
300
301static int dm_blk_open(struct block_device *bdev, fmode_t mode)
302{
303 struct mapped_device *md;
304
305 spin_lock(&_minor_lock);
306
307 md = bdev->bd_disk->private_data;
308 if (!md)
309 goto out;
310
311 if (test_bit(DMF_FREEING, &md->flags) ||
312 dm_deleting_md(md)) {
313 md = NULL;
314 goto out;
315 }
316
317 dm_get(md);
318 atomic_inc(&md->open_count);
319out:
320 spin_unlock(&_minor_lock);
321
322 return md ? 0 : -ENXIO;
323}
324
325static void dm_blk_close(struct gendisk *disk, fmode_t mode)
326{
327 struct mapped_device *md;
328
329 spin_lock(&_minor_lock);
330
331 md = disk->private_data;
332 if (WARN_ON(!md))
333 goto out;
334
335 if (atomic_dec_and_test(&md->open_count) &&
336 (test_bit(DMF_DEFERRED_REMOVE, &md->flags)))
337 queue_work(deferred_remove_workqueue, &deferred_remove_work);
338
339 dm_put(md);
340out:
341 spin_unlock(&_minor_lock);
342}
343
344int dm_open_count(struct mapped_device *md)
345{
346 return atomic_read(&md->open_count);
347}
348
349/*
350 * Guarantees nothing is using the device before it's deleted.
351 */
352int dm_lock_for_deletion(struct mapped_device *md, bool mark_deferred, bool only_deferred)
353{
354 int r = 0;
355
356 spin_lock(&_minor_lock);
357
358 if (dm_open_count(md)) {
359 r = -EBUSY;
360 if (mark_deferred)
361 set_bit(DMF_DEFERRED_REMOVE, &md->flags);
362 } else if (only_deferred && !test_bit(DMF_DEFERRED_REMOVE, &md->flags))
363 r = -EEXIST;
364 else
365 set_bit(DMF_DELETING, &md->flags);
366
367 spin_unlock(&_minor_lock);
368
369 return r;
370}
371
372int dm_cancel_deferred_remove(struct mapped_device *md)
373{
374 int r = 0;
375
376 spin_lock(&_minor_lock);
377
378 if (test_bit(DMF_DELETING, &md->flags))
379 r = -EBUSY;
380 else
381 clear_bit(DMF_DEFERRED_REMOVE, &md->flags);
382
383 spin_unlock(&_minor_lock);
384
385 return r;
386}
387
388static void do_deferred_remove(struct work_struct *w)
389{
390 dm_deferred_remove();
391}
392
393sector_t dm_get_size(struct mapped_device *md)
394{
395 return get_capacity(md->disk);
396}
397
398struct request_queue *dm_get_md_queue(struct mapped_device *md)
399{
400 return md->queue;
401}
402
403struct dm_stats *dm_get_stats(struct mapped_device *md)
404{
405 return &md->stats;
406}
407
408static int dm_blk_getgeo(struct block_device *bdev, struct hd_geometry *geo)
409{
410 struct mapped_device *md = bdev->bd_disk->private_data;
411
412 return dm_get_geometry(md, geo);
413}
414
415static int dm_grab_bdev_for_ioctl(struct mapped_device *md,
416 struct block_device **bdev,
417 fmode_t *mode)
418{
419 struct dm_target *tgt;
420 struct dm_table *map;
421 int srcu_idx, r;
422
423retry:
424 r = -ENOTTY;
425 map = dm_get_live_table(md, &srcu_idx);
426 if (!map || !dm_table_get_size(map))
427 goto out;
428
429 /* We only support devices that have a single target */
430 if (dm_table_get_num_targets(map) != 1)
431 goto out;
432
433 tgt = dm_table_get_target(map, 0);
434 if (!tgt->type->prepare_ioctl)
435 goto out;
436
437 if (dm_suspended_md(md)) {
438 r = -EAGAIN;
439 goto out;
440 }
441
442 r = tgt->type->prepare_ioctl(tgt, bdev, mode);
443 if (r < 0)
444 goto out;
445
446 bdgrab(*bdev);
447 dm_put_live_table(md, srcu_idx);
448 return r;
449
450out:
451 dm_put_live_table(md, srcu_idx);
452 if (r == -ENOTCONN && !fatal_signal_pending(current)) {
453 msleep(10);
454 goto retry;
455 }
456 return r;
457}
458
459static int dm_blk_ioctl(struct block_device *bdev, fmode_t mode,
460 unsigned int cmd, unsigned long arg)
461{
462 struct mapped_device *md = bdev->bd_disk->private_data;
463 int r;
464
465 r = dm_grab_bdev_for_ioctl(md, &bdev, &mode);
466 if (r < 0)
467 return r;
468
469 if (r > 0) {
470 /*
471 * Target determined this ioctl is being issued against a
472 * subset of the parent bdev; require extra privileges.
473 */
474 if (!capable(CAP_SYS_RAWIO)) {
475 DMWARN_LIMIT(
476 "%s: sending ioctl %x to DM device without required privilege.",
477 current->comm, cmd);
478 r = -ENOIOCTLCMD;
479 goto out;
480 }
481 }
482
483 r = __blkdev_driver_ioctl(bdev, mode, cmd, arg);
484out:
485 bdput(bdev);
486 return r;
487}
488
489static struct dm_io *alloc_io(struct mapped_device *md)
490{
491 return mempool_alloc(md->io_pool, GFP_NOIO);
492}
493
494static void free_io(struct mapped_device *md, struct dm_io *io)
495{
496 mempool_free(io, md->io_pool);
497}
498
499static void free_tio(struct dm_target_io *tio)
500{
501 bio_put(&tio->clone);
502}
503
504int md_in_flight(struct mapped_device *md)
505{
506 return atomic_read(&md->pending[READ]) +
507 atomic_read(&md->pending[WRITE]);
508}
509
510static void start_io_acct(struct dm_io *io)
511{
512 struct mapped_device *md = io->md;
513 struct bio *bio = io->bio;
514 int cpu;
515 int rw = bio_data_dir(bio);
516
517 io->start_time = jiffies;
518
519 cpu = part_stat_lock();
520 part_round_stats(md->queue, cpu, &dm_disk(md)->part0);
521 part_stat_unlock();
522 atomic_set(&dm_disk(md)->part0.in_flight[rw],
523 atomic_inc_return(&md->pending[rw]));
524
525 if (unlikely(dm_stats_used(&md->stats)))
526 dm_stats_account_io(&md->stats, bio_data_dir(bio),
527 bio->bi_iter.bi_sector, bio_sectors(bio),
528 false, 0, &io->stats_aux);
529}
530
531static void end_io_acct(struct dm_io *io)
532{
533 struct mapped_device *md = io->md;
534 struct bio *bio = io->bio;
535 unsigned long duration = jiffies - io->start_time;
536 int pending;
537 int rw = bio_data_dir(bio);
538
539 generic_end_io_acct(md->queue, rw, &dm_disk(md)->part0, io->start_time);
540
541 if (unlikely(dm_stats_used(&md->stats)))
542 dm_stats_account_io(&md->stats, bio_data_dir(bio),
543 bio->bi_iter.bi_sector, bio_sectors(bio),
544 true, duration, &io->stats_aux);
545
546 /*
547 * After this is decremented the bio must not be touched if it is
548 * a flush.
549 */
550 pending = atomic_dec_return(&md->pending[rw]);
551 atomic_set(&dm_disk(md)->part0.in_flight[rw], pending);
552 pending += atomic_read(&md->pending[rw^0x1]);
553
554 /* nudge anyone waiting on suspend queue */
555 if (!pending)
556 wake_up(&md->wait);
557}
558
559/*
560 * Add the bio to the list of deferred io.
561 */
562static void queue_io(struct mapped_device *md, struct bio *bio)
563{
564 unsigned long flags;
565
566 spin_lock_irqsave(&md->deferred_lock, flags);
567 bio_list_add(&md->deferred, bio);
568 spin_unlock_irqrestore(&md->deferred_lock, flags);
569 queue_work(md->wq, &md->work);
570}
571
572/*
573 * Everyone (including functions in this file), should use this
574 * function to access the md->map field, and make sure they call
575 * dm_put_live_table() when finished.
576 */
577struct dm_table *dm_get_live_table(struct mapped_device *md, int *srcu_idx) __acquires(md->io_barrier)
578{
579 *srcu_idx = srcu_read_lock(&md->io_barrier);
580
581 return srcu_dereference(md->map, &md->io_barrier);
582}
583
584void dm_put_live_table(struct mapped_device *md, int srcu_idx) __releases(md->io_barrier)
585{
586 srcu_read_unlock(&md->io_barrier, srcu_idx);
587}
588
589void dm_sync_table(struct mapped_device *md)
590{
591 synchronize_srcu(&md->io_barrier);
592 synchronize_rcu_expedited();
593}
594
595/*
596 * A fast alternative to dm_get_live_table/dm_put_live_table.
597 * The caller must not block between these two functions.
598 */
599static struct dm_table *dm_get_live_table_fast(struct mapped_device *md) __acquires(RCU)
600{
601 rcu_read_lock();
602 return rcu_dereference(md->map);
603}
604
605static void dm_put_live_table_fast(struct mapped_device *md) __releases(RCU)
606{
607 rcu_read_unlock();
608}
609
610/*
611 * Open a table device so we can use it as a map destination.
612 */
613static int open_table_device(struct table_device *td, dev_t dev,
614 struct mapped_device *md)
615{
616 static char *_claim_ptr = "I belong to device-mapper";
617 struct block_device *bdev;
618
619 int r;
620
621 BUG_ON(td->dm_dev.bdev);
622
623 bdev = blkdev_get_by_dev(dev, td->dm_dev.mode | FMODE_EXCL, _claim_ptr);
624 if (IS_ERR(bdev))
625 return PTR_ERR(bdev);
626
627 r = bd_link_disk_holder(bdev, dm_disk(md));
628 if (r) {
629 blkdev_put(bdev, td->dm_dev.mode | FMODE_EXCL);
630 return r;
631 }
632
633 td->dm_dev.bdev = bdev;
634 td->dm_dev.dax_dev = dax_get_by_host(bdev->bd_disk->disk_name);
635 return 0;
636}
637
638/*
639 * Close a table device that we've been using.
640 */
641static void close_table_device(struct table_device *td, struct mapped_device *md)
642{
643 if (!td->dm_dev.bdev)
644 return;
645
646 bd_unlink_disk_holder(td->dm_dev.bdev, dm_disk(md));
647 blkdev_put(td->dm_dev.bdev, td->dm_dev.mode | FMODE_EXCL);
648 put_dax(td->dm_dev.dax_dev);
649 td->dm_dev.bdev = NULL;
650 td->dm_dev.dax_dev = NULL;
651}
652
653static struct table_device *find_table_device(struct list_head *l, dev_t dev,
654 fmode_t mode) {
655 struct table_device *td;
656
657 list_for_each_entry(td, l, list)
658 if (td->dm_dev.bdev->bd_dev == dev && td->dm_dev.mode == mode)
659 return td;
660
661 return NULL;
662}
663
664int dm_get_table_device(struct mapped_device *md, dev_t dev, fmode_t mode,
665 struct dm_dev **result) {
666 int r;
667 struct table_device *td;
668
669 mutex_lock(&md->table_devices_lock);
670 td = find_table_device(&md->table_devices, dev, mode);
671 if (!td) {
672 td = kmalloc_node(sizeof(*td), GFP_KERNEL, md->numa_node_id);
673 if (!td) {
674 mutex_unlock(&md->table_devices_lock);
675 return -ENOMEM;
676 }
677
678 td->dm_dev.mode = mode;
679 td->dm_dev.bdev = NULL;
680
681 if ((r = open_table_device(td, dev, md))) {
682 mutex_unlock(&md->table_devices_lock);
683 kfree(td);
684 return r;
685 }
686
687 format_dev_t(td->dm_dev.name, dev);
688
689 atomic_set(&td->count, 0);
690 list_add(&td->list, &md->table_devices);
691 }
692 atomic_inc(&td->count);
693 mutex_unlock(&md->table_devices_lock);
694
695 *result = &td->dm_dev;
696 return 0;
697}
698EXPORT_SYMBOL_GPL(dm_get_table_device);
699
700void dm_put_table_device(struct mapped_device *md, struct dm_dev *d)
701{
702 struct table_device *td = container_of(d, struct table_device, dm_dev);
703
704 mutex_lock(&md->table_devices_lock);
705 if (atomic_dec_and_test(&td->count)) {
706 close_table_device(td, md);
707 list_del(&td->list);
708 kfree(td);
709 }
710 mutex_unlock(&md->table_devices_lock);
711}
712EXPORT_SYMBOL(dm_put_table_device);
713
714static void free_table_devices(struct list_head *devices)
715{
716 struct list_head *tmp, *next;
717
718 list_for_each_safe(tmp, next, devices) {
719 struct table_device *td = list_entry(tmp, struct table_device, list);
720
721 DMWARN("dm_destroy: %s still exists with %d references",
722 td->dm_dev.name, atomic_read(&td->count));
723 kfree(td);
724 }
725}
726
727/*
728 * Get the geometry associated with a dm device
729 */
730int dm_get_geometry(struct mapped_device *md, struct hd_geometry *geo)
731{
732 *geo = md->geometry;
733
734 return 0;
735}
736
737/*
738 * Set the geometry of a device.
739 */
740int dm_set_geometry(struct mapped_device *md, struct hd_geometry *geo)
741{
742 sector_t sz = (sector_t)geo->cylinders * geo->heads * geo->sectors;
743
744 if (geo->start > sz) {
745 DMWARN("Start sector is beyond the geometry limits.");
746 return -EINVAL;
747 }
748
749 md->geometry = *geo;
750
751 return 0;
752}
753
754/*-----------------------------------------------------------------
755 * CRUD START:
756 * A more elegant soln is in the works that uses the queue
757 * merge fn, unfortunately there are a couple of changes to
758 * the block layer that I want to make for this. So in the
759 * interests of getting something for people to use I give
760 * you this clearly demarcated crap.
761 *---------------------------------------------------------------*/
762
763static int __noflush_suspending(struct mapped_device *md)
764{
765 return test_bit(DMF_NOFLUSH_SUSPENDING, &md->flags);
766}
767
768/*
769 * Decrements the number of outstanding ios that a bio has been
770 * cloned into, completing the original io if necc.
771 */
772static void dec_pending(struct dm_io *io, blk_status_t error)
773{
774 unsigned long flags;
775 blk_status_t io_error;
776 struct bio *bio;
777 struct mapped_device *md = io->md;
778
779 /* Push-back supersedes any I/O errors */
780 if (unlikely(error)) {
781 spin_lock_irqsave(&io->endio_lock, flags);
782 if (!(io->status == BLK_STS_DM_REQUEUE &&
783 __noflush_suspending(md)))
784 io->status = error;
785 spin_unlock_irqrestore(&io->endio_lock, flags);
786 }
787
788 if (atomic_dec_and_test(&io->io_count)) {
789 if (io->status == BLK_STS_DM_REQUEUE) {
790 /*
791 * Target requested pushing back the I/O.
792 */
793 spin_lock_irqsave(&md->deferred_lock, flags);
794 if (__noflush_suspending(md))
795 bio_list_add_head(&md->deferred, io->bio);
796 else
797 /* noflush suspend was interrupted. */
798 io->status = BLK_STS_IOERR;
799 spin_unlock_irqrestore(&md->deferred_lock, flags);
800 }
801
802 io_error = io->status;
803 bio = io->bio;
804 end_io_acct(io);
805 free_io(md, io);
806
807 if (io_error == BLK_STS_DM_REQUEUE)
808 return;
809
810 if ((bio->bi_opf & REQ_PREFLUSH) && bio->bi_iter.bi_size) {
811 /*
812 * Preflush done for flush with data, reissue
813 * without REQ_PREFLUSH.
814 */
815 bio->bi_opf &= ~REQ_PREFLUSH;
816 queue_io(md, bio);
817 } else {
818 /* done with normal IO or empty flush */
819 if (io_error)
820 bio->bi_status = io_error;
821 bio_endio(bio);
822 }
823 }
824}
825
826void disable_write_same(struct mapped_device *md)
827{
828 struct queue_limits *limits = dm_get_queue_limits(md);
829
830 /* device doesn't really support WRITE SAME, disable it */
831 limits->max_write_same_sectors = 0;
832}
833
834void disable_write_zeroes(struct mapped_device *md)
835{
836 struct queue_limits *limits = dm_get_queue_limits(md);
837
838 /* device doesn't really support WRITE ZEROES, disable it */
839 limits->max_write_zeroes_sectors = 0;
840}
841
842static void clone_endio(struct bio *bio)
843{
844 blk_status_t error = bio->bi_status;
845 struct dm_target_io *tio = container_of(bio, struct dm_target_io, clone);
846 struct dm_io *io = tio->io;
847 struct mapped_device *md = tio->io->md;
848 dm_endio_fn endio = tio->ti->type->end_io;
849
850 if (unlikely(error == BLK_STS_TARGET)) {
851 if (bio_op(bio) == REQ_OP_WRITE_SAME &&
852 !bio->bi_disk->queue->limits.max_write_same_sectors)
853 disable_write_same(md);
854 if (bio_op(bio) == REQ_OP_WRITE_ZEROES &&
855 !bio->bi_disk->queue->limits.max_write_zeroes_sectors)
856 disable_write_zeroes(md);
857 }
858
859 if (endio) {
860 int r = endio(tio->ti, bio, &error);
861 switch (r) {
862 case DM_ENDIO_REQUEUE:
863 error = BLK_STS_DM_REQUEUE;
864 /*FALLTHRU*/
865 case DM_ENDIO_DONE:
866 break;
867 case DM_ENDIO_INCOMPLETE:
868 /* The target will handle the io */
869 return;
870 default:
871 DMWARN("unimplemented target endio return value: %d", r);
872 BUG();
873 }
874 }
875
876 free_tio(tio);
877 dec_pending(io, error);
878}
879
880/*
881 * Return maximum size of I/O possible at the supplied sector up to the current
882 * target boundary.
883 */
884static sector_t max_io_len_target_boundary(sector_t sector, struct dm_target *ti)
885{
886 sector_t target_offset = dm_target_offset(ti, sector);
887
888 return ti->len - target_offset;
889}
890
891static sector_t max_io_len(sector_t sector, struct dm_target *ti)
892{
893 sector_t len = max_io_len_target_boundary(sector, ti);
894 sector_t offset, max_len;
895
896 /*
897 * Does the target need to split even further?
898 */
899 if (ti->max_io_len) {
900 offset = dm_target_offset(ti, sector);
901 if (unlikely(ti->max_io_len & (ti->max_io_len - 1)))
902 max_len = sector_div(offset, ti->max_io_len);
903 else
904 max_len = offset & (ti->max_io_len - 1);
905 max_len = ti->max_io_len - max_len;
906
907 if (len > max_len)
908 len = max_len;
909 }
910
911 return len;
912}
913
914int dm_set_target_max_io_len(struct dm_target *ti, sector_t len)
915{
916 if (len > UINT_MAX) {
917 DMERR("Specified maximum size of target IO (%llu) exceeds limit (%u)",
918 (unsigned long long)len, UINT_MAX);
919 ti->error = "Maximum size of target IO is too large";
920 return -EINVAL;
921 }
922
923 ti->max_io_len = (uint32_t) len;
924
925 return 0;
926}
927EXPORT_SYMBOL_GPL(dm_set_target_max_io_len);
928
929static struct dm_target *dm_dax_get_live_target(struct mapped_device *md,
930 sector_t sector, int *srcu_idx)
931{
932 struct dm_table *map;
933 struct dm_target *ti;
934
935 map = dm_get_live_table(md, srcu_idx);
936 if (!map)
937 return NULL;
938
939 ti = dm_table_find_target(map, sector);
940 if (!dm_target_is_valid(ti))
941 return NULL;
942
943 return ti;
944}
945
946static long dm_dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff,
947 long nr_pages, void **kaddr, pfn_t *pfn)
948{
949 struct mapped_device *md = dax_get_private(dax_dev);
950 sector_t sector = pgoff * PAGE_SECTORS;
951 struct dm_target *ti;
952 long len, ret = -EIO;
953 int srcu_idx;
954
955 ti = dm_dax_get_live_target(md, sector, &srcu_idx);
956
957 if (!ti)
958 goto out;
959 if (!ti->type->direct_access)
960 goto out;
961 len = max_io_len(sector, ti) / PAGE_SECTORS;
962 if (len < 1)
963 goto out;
964 nr_pages = min(len, nr_pages);
965 ret = ti->type->direct_access(ti, pgoff, nr_pages, kaddr, pfn);
966
967 out:
968 dm_put_live_table(md, srcu_idx);
969
970 return ret;
971}
972
973static size_t dm_dax_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff,
974 void *addr, size_t bytes, struct iov_iter *i)
975{
976 struct mapped_device *md = dax_get_private(dax_dev);
977 sector_t sector = pgoff * PAGE_SECTORS;
978 struct dm_target *ti;
979 long ret = 0;
980 int srcu_idx;
981
982 ti = dm_dax_get_live_target(md, sector, &srcu_idx);
983
984 if (!ti)
985 goto out;
986 if (!ti->type->dax_copy_from_iter) {
987 ret = copy_from_iter(addr, bytes, i);
988 goto out;
989 }
990 ret = ti->type->dax_copy_from_iter(ti, pgoff, addr, bytes, i);
991 out:
992 dm_put_live_table(md, srcu_idx);
993
994 return ret;
995}
996
997/*
998 * A target may call dm_accept_partial_bio only from the map routine. It is
999 * allowed for all bio types except REQ_PREFLUSH.
1000 *
1001 * dm_accept_partial_bio informs the dm that the target only wants to process
1002 * additional n_sectors sectors of the bio and the rest of the data should be
1003 * sent in a next bio.
1004 *
1005 * A diagram that explains the arithmetics:
1006 * +--------------------+---------------+-------+
1007 * | 1 | 2 | 3 |
1008 * +--------------------+---------------+-------+
1009 *
1010 * <-------------- *tio->len_ptr --------------->
1011 * <------- bi_size ------->
1012 * <-- n_sectors -->
1013 *
1014 * Region 1 was already iterated over with bio_advance or similar function.
1015 * (it may be empty if the target doesn't use bio_advance)
1016 * Region 2 is the remaining bio size that the target wants to process.
1017 * (it may be empty if region 1 is non-empty, although there is no reason
1018 * to make it empty)
1019 * The target requires that region 3 is to be sent in the next bio.
1020 *
1021 * If the target wants to receive multiple copies of the bio (via num_*bios, etc),
1022 * the partially processed part (the sum of regions 1+2) must be the same for all
1023 * copies of the bio.
1024 */
1025void dm_accept_partial_bio(struct bio *bio, unsigned n_sectors)
1026{
1027 struct dm_target_io *tio = container_of(bio, struct dm_target_io, clone);
1028 unsigned bi_size = bio->bi_iter.bi_size >> SECTOR_SHIFT;
1029 BUG_ON(bio->bi_opf & REQ_PREFLUSH);
1030 BUG_ON(bi_size > *tio->len_ptr);
1031 BUG_ON(n_sectors > bi_size);
1032 *tio->len_ptr -= bi_size - n_sectors;
1033 bio->bi_iter.bi_size = n_sectors << SECTOR_SHIFT;
1034}
1035EXPORT_SYMBOL_GPL(dm_accept_partial_bio);
1036
1037/*
1038 * The zone descriptors obtained with a zone report indicate zone positions
1039 * within the target backing device, regardless of that device is a partition
1040 * and regardless of the target mapping start sector on the device or partition.
1041 * The zone descriptors start sector and write pointer position must be adjusted
1042 * to match their relative position within the dm device.
1043 * A target may call dm_remap_zone_report() after completion of a
1044 * REQ_OP_ZONE_REPORT bio to remap the zone descriptors obtained from the
1045 * backing device.
1046 */
1047void dm_remap_zone_report(struct dm_target *ti, struct bio *bio, sector_t start)
1048{
1049#ifdef CONFIG_BLK_DEV_ZONED
1050 struct dm_target_io *tio = container_of(bio, struct dm_target_io, clone);
1051 struct bio *report_bio = tio->io->bio;
1052 struct blk_zone_report_hdr *hdr = NULL;
1053 struct blk_zone *zone;
1054 unsigned int nr_rep = 0;
1055 unsigned int ofst;
1056 sector_t part_offset;
1057 struct bio_vec bvec;
1058 struct bvec_iter iter;
1059 void *addr;
1060
1061 if (bio->bi_status)
1062 return;
1063
1064 /*
1065 * bio sector was incremented by the request size on completion. Taking
1066 * into account the original request sector, the target start offset on
1067 * the backing device and the target mapping offset (ti->begin), the
1068 * start sector of the backing device. The partition offset is always 0
1069 * if the target uses a whole device.
1070 */
1071 part_offset = bio->bi_iter.bi_sector + ti->begin - (start + bio_end_sector(report_bio));
1072
1073 /*
1074 * Remap the start sector of the reported zones. For sequential zones,
1075 * also remap the write pointer position.
1076 */
1077 bio_for_each_segment(bvec, report_bio, iter) {
1078 addr = kmap_atomic(bvec.bv_page);
1079
1080 /* Remember the report header in the first page */
1081 if (!hdr) {
1082 hdr = addr;
1083 ofst = sizeof(struct blk_zone_report_hdr);
1084 } else
1085 ofst = 0;
1086
1087 /* Set zones start sector */
1088 while (hdr->nr_zones && ofst < bvec.bv_len) {
1089 zone = addr + ofst;
1090 zone->start -= part_offset;
1091 if (zone->start >= start + ti->len) {
1092 hdr->nr_zones = 0;
1093 break;
1094 }
1095 zone->start = zone->start + ti->begin - start;
1096 if (zone->type != BLK_ZONE_TYPE_CONVENTIONAL) {
1097 if (zone->cond == BLK_ZONE_COND_FULL)
1098 zone->wp = zone->start + zone->len;
1099 else if (zone->cond == BLK_ZONE_COND_EMPTY)
1100 zone->wp = zone->start;
1101 else
1102 zone->wp = zone->wp + ti->begin - start - part_offset;
1103 }
1104 ofst += sizeof(struct blk_zone);
1105 hdr->nr_zones--;
1106 nr_rep++;
1107 }
1108
1109 if (addr != hdr)
1110 kunmap_atomic(addr);
1111
1112 if (!hdr->nr_zones)
1113 break;
1114 }
1115
1116 if (hdr) {
1117 hdr->nr_zones = nr_rep;
1118 kunmap_atomic(hdr);
1119 }
1120
1121 bio_advance(report_bio, report_bio->bi_iter.bi_size);
1122
1123#else /* !CONFIG_BLK_DEV_ZONED */
1124 bio->bi_status = BLK_STS_NOTSUPP;
1125#endif
1126}
1127EXPORT_SYMBOL_GPL(dm_remap_zone_report);
1128
1129/*
1130 * Flush current->bio_list when the target map method blocks.
1131 * This fixes deadlocks in snapshot and possibly in other targets.
1132 */
1133struct dm_offload {
1134 struct blk_plug plug;
1135 struct blk_plug_cb cb;
1136};
1137
1138static void flush_current_bio_list(struct blk_plug_cb *cb, bool from_schedule)
1139{
1140 struct dm_offload *o = container_of(cb, struct dm_offload, cb);
1141 struct bio_list list;
1142 struct bio *bio;
1143 int i;
1144
1145 INIT_LIST_HEAD(&o->cb.list);
1146
1147 if (unlikely(!current->bio_list))
1148 return;
1149
1150 for (i = 0; i < 2; i++) {
1151 list = current->bio_list[i];
1152 bio_list_init(&current->bio_list[i]);
1153
1154 while ((bio = bio_list_pop(&list))) {
1155 struct bio_set *bs = bio->bi_pool;
1156 if (unlikely(!bs) || bs == fs_bio_set ||
1157 !bs->rescue_workqueue) {
1158 bio_list_add(&current->bio_list[i], bio);
1159 continue;
1160 }
1161
1162 spin_lock(&bs->rescue_lock);
1163 bio_list_add(&bs->rescue_list, bio);
1164 queue_work(bs->rescue_workqueue, &bs->rescue_work);
1165 spin_unlock(&bs->rescue_lock);
1166 }
1167 }
1168}
1169
1170static void dm_offload_start(struct dm_offload *o)
1171{
1172 blk_start_plug(&o->plug);
1173 o->cb.callback = flush_current_bio_list;
1174 list_add(&o->cb.list, &current->plug->cb_list);
1175}
1176
1177static void dm_offload_end(struct dm_offload *o)
1178{
1179 list_del(&o->cb.list);
1180 blk_finish_plug(&o->plug);
1181}
1182
1183static void __map_bio(struct dm_target_io *tio)
1184{
1185 int r;
1186 sector_t sector;
1187 struct dm_offload o;
1188 struct bio *clone = &tio->clone;
1189 struct dm_target *ti = tio->ti;
1190
1191 clone->bi_end_io = clone_endio;
1192
1193 /*
1194 * Map the clone. If r == 0 we don't need to do
1195 * anything, the target has assumed ownership of
1196 * this io.
1197 */
1198 atomic_inc(&tio->io->io_count);
1199 sector = clone->bi_iter.bi_sector;
1200
1201 dm_offload_start(&o);
1202 r = ti->type->map(ti, clone);
1203 dm_offload_end(&o);
1204
1205 switch (r) {
1206 case DM_MAPIO_SUBMITTED:
1207 break;
1208 case DM_MAPIO_REMAPPED:
1209 /* the bio has been remapped so dispatch it */
1210 trace_block_bio_remap(clone->bi_disk->queue, clone,
1211 bio_dev(tio->io->bio), sector);
1212 generic_make_request(clone);
1213 break;
1214 case DM_MAPIO_KILL:
1215 dec_pending(tio->io, BLK_STS_IOERR);
1216 free_tio(tio);
1217 break;
1218 case DM_MAPIO_REQUEUE:
1219 dec_pending(tio->io, BLK_STS_DM_REQUEUE);
1220 free_tio(tio);
1221 break;
1222 default:
1223 DMWARN("unimplemented target map return value: %d", r);
1224 BUG();
1225 }
1226}
1227
1228struct clone_info {
1229 struct mapped_device *md;
1230 struct dm_table *map;
1231 struct bio *bio;
1232 struct dm_io *io;
1233 sector_t sector;
1234 unsigned sector_count;
1235};
1236
1237static void bio_setup_sector(struct bio *bio, sector_t sector, unsigned len)
1238{
1239 bio->bi_iter.bi_sector = sector;
1240 bio->bi_iter.bi_size = to_bytes(len);
1241}
1242
1243/*
1244 * Creates a bio that consists of range of complete bvecs.
1245 */
1246static int clone_bio(struct dm_target_io *tio, struct bio *bio,
1247 sector_t sector, unsigned len)
1248{
1249 struct bio *clone = &tio->clone;
1250
1251 __bio_clone_fast(clone, bio);
1252
1253 if (unlikely(bio_integrity(bio) != NULL)) {
1254 int r;
1255
1256 if (unlikely(!dm_target_has_integrity(tio->ti->type) &&
1257 !dm_target_passes_integrity(tio->ti->type))) {
1258 DMWARN("%s: the target %s doesn't support integrity data.",
1259 dm_device_name(tio->io->md),
1260 tio->ti->type->name);
1261 return -EIO;
1262 }
1263
1264 r = bio_integrity_clone(clone, bio, GFP_NOIO);
1265 if (r < 0)
1266 return r;
1267 }
1268
1269 if (bio_op(bio) != REQ_OP_ZONE_REPORT)
1270 bio_advance(clone, to_bytes(sector - clone->bi_iter.bi_sector));
1271 clone->bi_iter.bi_size = to_bytes(len);
1272
1273 if (unlikely(bio_integrity(bio) != NULL))
1274 bio_integrity_trim(clone);
1275
1276 return 0;
1277}
1278
1279static struct dm_target_io *alloc_tio(struct clone_info *ci,
1280 struct dm_target *ti,
1281 unsigned target_bio_nr)
1282{
1283 struct dm_target_io *tio;
1284 struct bio *clone;
1285
1286 clone = bio_alloc_bioset(GFP_NOIO, 0, ci->md->bs);
1287 tio = container_of(clone, struct dm_target_io, clone);
1288
1289 tio->io = ci->io;
1290 tio->ti = ti;
1291 tio->target_bio_nr = target_bio_nr;
1292
1293 return tio;
1294}
1295
1296static void __clone_and_map_simple_bio(struct clone_info *ci,
1297 struct dm_target *ti,
1298 unsigned target_bio_nr, unsigned *len)
1299{
1300 struct dm_target_io *tio = alloc_tio(ci, ti, target_bio_nr);
1301 struct bio *clone = &tio->clone;
1302
1303 tio->len_ptr = len;
1304
1305 __bio_clone_fast(clone, ci->bio);
1306 if (len)
1307 bio_setup_sector(clone, ci->sector, *len);
1308
1309 __map_bio(tio);
1310}
1311
1312static void __send_duplicate_bios(struct clone_info *ci, struct dm_target *ti,
1313 unsigned num_bios, unsigned *len)
1314{
1315 unsigned target_bio_nr;
1316
1317 for (target_bio_nr = 0; target_bio_nr < num_bios; target_bio_nr++)
1318 __clone_and_map_simple_bio(ci, ti, target_bio_nr, len);
1319}
1320
1321static int __send_empty_flush(struct clone_info *ci)
1322{
1323 unsigned target_nr = 0;
1324 struct dm_target *ti;
1325
1326 BUG_ON(bio_has_data(ci->bio));
1327 while ((ti = dm_table_get_target(ci->map, target_nr++)))
1328 __send_duplicate_bios(ci, ti, ti->num_flush_bios, NULL);
1329
1330 return 0;
1331}
1332
1333static int __clone_and_map_data_bio(struct clone_info *ci, struct dm_target *ti,
1334 sector_t sector, unsigned *len)
1335{
1336 struct bio *bio = ci->bio;
1337 struct dm_target_io *tio;
1338 unsigned target_bio_nr;
1339 unsigned num_target_bios = 1;
1340 int r = 0;
1341
1342 /*
1343 * Does the target want to receive duplicate copies of the bio?
1344 */
1345 if (bio_data_dir(bio) == WRITE && ti->num_write_bios)
1346 num_target_bios = ti->num_write_bios(ti, bio);
1347
1348 for (target_bio_nr = 0; target_bio_nr < num_target_bios; target_bio_nr++) {
1349 tio = alloc_tio(ci, ti, target_bio_nr);
1350 tio->len_ptr = len;
1351 r = clone_bio(tio, bio, sector, *len);
1352 if (r < 0) {
1353 free_tio(tio);
1354 break;
1355 }
1356 __map_bio(tio);
1357 }
1358
1359 return r;
1360}
1361
1362typedef unsigned (*get_num_bios_fn)(struct dm_target *ti);
1363
1364static unsigned get_num_discard_bios(struct dm_target *ti)
1365{
1366 return ti->num_discard_bios;
1367}
1368
1369static unsigned get_num_write_same_bios(struct dm_target *ti)
1370{
1371 return ti->num_write_same_bios;
1372}
1373
1374static unsigned get_num_write_zeroes_bios(struct dm_target *ti)
1375{
1376 return ti->num_write_zeroes_bios;
1377}
1378
1379typedef bool (*is_split_required_fn)(struct dm_target *ti);
1380
1381static bool is_split_required_for_discard(struct dm_target *ti)
1382{
1383 return ti->split_discard_bios;
1384}
1385
1386static int __send_changing_extent_only(struct clone_info *ci,
1387 get_num_bios_fn get_num_bios,
1388 is_split_required_fn is_split_required)
1389{
1390 struct dm_target *ti;
1391 unsigned len;
1392 unsigned num_bios;
1393
1394 do {
1395 ti = dm_table_find_target(ci->map, ci->sector);
1396 if (!dm_target_is_valid(ti))
1397 return -EIO;
1398
1399 /*
1400 * Even though the device advertised support for this type of
1401 * request, that does not mean every target supports it, and
1402 * reconfiguration might also have changed that since the
1403 * check was performed.
1404 */
1405 num_bios = get_num_bios ? get_num_bios(ti) : 0;
1406 if (!num_bios)
1407 return -EOPNOTSUPP;
1408
1409 if (is_split_required && !is_split_required(ti))
1410 len = min((sector_t)ci->sector_count, max_io_len_target_boundary(ci->sector, ti));
1411 else
1412 len = min((sector_t)ci->sector_count, max_io_len(ci->sector, ti));
1413
1414 __send_duplicate_bios(ci, ti, num_bios, &len);
1415
1416 ci->sector += len;
1417 } while (ci->sector_count -= len);
1418
1419 return 0;
1420}
1421
1422static int __send_discard(struct clone_info *ci)
1423{
1424 return __send_changing_extent_only(ci, get_num_discard_bios,
1425 is_split_required_for_discard);
1426}
1427
1428static int __send_write_same(struct clone_info *ci)
1429{
1430 return __send_changing_extent_only(ci, get_num_write_same_bios, NULL);
1431}
1432
1433static int __send_write_zeroes(struct clone_info *ci)
1434{
1435 return __send_changing_extent_only(ci, get_num_write_zeroes_bios, NULL);
1436}
1437
1438/*
1439 * Select the correct strategy for processing a non-flush bio.
1440 */
1441static int __split_and_process_non_flush(struct clone_info *ci)
1442{
1443 struct bio *bio = ci->bio;
1444 struct dm_target *ti;
1445 unsigned len;
1446 int r;
1447
1448 if (unlikely(bio_op(bio) == REQ_OP_DISCARD))
1449 return __send_discard(ci);
1450 else if (unlikely(bio_op(bio) == REQ_OP_WRITE_SAME))
1451 return __send_write_same(ci);
1452 else if (unlikely(bio_op(bio) == REQ_OP_WRITE_ZEROES))
1453 return __send_write_zeroes(ci);
1454
1455 ti = dm_table_find_target(ci->map, ci->sector);
1456 if (!dm_target_is_valid(ti))
1457 return -EIO;
1458
1459 if (bio_op(bio) == REQ_OP_ZONE_REPORT)
1460 len = ci->sector_count;
1461 else
1462 len = min_t(sector_t, max_io_len(ci->sector, ti),
1463 ci->sector_count);
1464
1465 r = __clone_and_map_data_bio(ci, ti, ci->sector, &len);
1466 if (r < 0)
1467 return r;
1468
1469 ci->sector += len;
1470 ci->sector_count -= len;
1471
1472 return 0;
1473}
1474
1475/*
1476 * Entry point to split a bio into clones and submit them to the targets.
1477 */
1478static void __split_and_process_bio(struct mapped_device *md,
1479 struct dm_table *map, struct bio *bio)
1480{
1481 struct clone_info ci;
1482 int error = 0;
1483
1484 if (unlikely(!map)) {
1485 bio_io_error(bio);
1486 return;
1487 }
1488
1489 ci.map = map;
1490 ci.md = md;
1491 ci.io = alloc_io(md);
1492 ci.io->status = 0;
1493 atomic_set(&ci.io->io_count, 1);
1494 ci.io->bio = bio;
1495 ci.io->md = md;
1496 spin_lock_init(&ci.io->endio_lock);
1497 ci.sector = bio->bi_iter.bi_sector;
1498
1499 start_io_acct(ci.io);
1500
1501 if (bio->bi_opf & REQ_PREFLUSH) {
1502 ci.bio = &ci.md->flush_bio;
1503 ci.sector_count = 0;
1504 error = __send_empty_flush(&ci);
1505 /* dec_pending submits any data associated with flush */
1506 } else if (bio_op(bio) == REQ_OP_ZONE_RESET) {
1507 ci.bio = bio;
1508 ci.sector_count = 0;
1509 error = __split_and_process_non_flush(&ci);
1510 } else {
1511 ci.bio = bio;
1512 ci.sector_count = bio_sectors(bio);
1513 while (ci.sector_count && !error)
1514 error = __split_and_process_non_flush(&ci);
1515 }
1516
1517 /* drop the extra reference count */
1518 dec_pending(ci.io, errno_to_blk_status(error));
1519}
1520/*-----------------------------------------------------------------
1521 * CRUD END
1522 *---------------------------------------------------------------*/
1523
1524/*
1525 * The request function that just remaps the bio built up by
1526 * dm_merge_bvec.
1527 */
1528static blk_qc_t dm_make_request(struct request_queue *q, struct bio *bio)
1529{
1530 int rw = bio_data_dir(bio);
1531 struct mapped_device *md = q->queuedata;
1532 int srcu_idx;
1533 struct dm_table *map;
1534
1535 map = dm_get_live_table(md, &srcu_idx);
1536
1537 generic_start_io_acct(q, rw, bio_sectors(bio), &dm_disk(md)->part0);
1538
1539 /* if we're suspended, we have to queue this io for later */
1540 if (unlikely(test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags))) {
1541 dm_put_live_table(md, srcu_idx);
1542
1543 if (!(bio->bi_opf & REQ_RAHEAD))
1544 queue_io(md, bio);
1545 else
1546 bio_io_error(bio);
1547 return BLK_QC_T_NONE;
1548 }
1549
1550 __split_and_process_bio(md, map, bio);
1551 dm_put_live_table(md, srcu_idx);
1552 return BLK_QC_T_NONE;
1553}
1554
1555static int dm_any_congested(void *congested_data, int bdi_bits)
1556{
1557 int r = bdi_bits;
1558 struct mapped_device *md = congested_data;
1559 struct dm_table *map;
1560
1561 if (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) {
1562 if (dm_request_based(md)) {
1563 /*
1564 * With request-based DM we only need to check the
1565 * top-level queue for congestion.
1566 */
1567 r = md->queue->backing_dev_info->wb.state & bdi_bits;
1568 } else {
1569 map = dm_get_live_table_fast(md);
1570 if (map)
1571 r = dm_table_any_congested(map, bdi_bits);
1572 dm_put_live_table_fast(md);
1573 }
1574 }
1575
1576 return r;
1577}
1578
1579/*-----------------------------------------------------------------
1580 * An IDR is used to keep track of allocated minor numbers.
1581 *---------------------------------------------------------------*/
1582static void free_minor(int minor)
1583{
1584 spin_lock(&_minor_lock);
1585 idr_remove(&_minor_idr, minor);
1586 spin_unlock(&_minor_lock);
1587}
1588
1589/*
1590 * See if the device with a specific minor # is free.
1591 */
1592static int specific_minor(int minor)
1593{
1594 int r;
1595
1596 if (minor >= (1 << MINORBITS))
1597 return -EINVAL;
1598
1599 idr_preload(GFP_KERNEL);
1600 spin_lock(&_minor_lock);
1601
1602 r = idr_alloc(&_minor_idr, MINOR_ALLOCED, minor, minor + 1, GFP_NOWAIT);
1603
1604 spin_unlock(&_minor_lock);
1605 idr_preload_end();
1606 if (r < 0)
1607 return r == -ENOSPC ? -EBUSY : r;
1608 return 0;
1609}
1610
1611static int next_free_minor(int *minor)
1612{
1613 int r;
1614
1615 idr_preload(GFP_KERNEL);
1616 spin_lock(&_minor_lock);
1617
1618 r = idr_alloc(&_minor_idr, MINOR_ALLOCED, 0, 1 << MINORBITS, GFP_NOWAIT);
1619
1620 spin_unlock(&_minor_lock);
1621 idr_preload_end();
1622 if (r < 0)
1623 return r;
1624 *minor = r;
1625 return 0;
1626}
1627
1628static const struct block_device_operations dm_blk_dops;
1629static const struct dax_operations dm_dax_ops;
1630
1631static void dm_wq_work(struct work_struct *work);
1632
1633void dm_init_md_queue(struct mapped_device *md)
1634{
1635 /*
1636 * Request-based dm devices cannot be stacked on top of bio-based dm
1637 * devices. The type of this dm device may not have been decided yet.
1638 * The type is decided at the first table loading time.
1639 * To prevent problematic device stacking, clear the queue flag
1640 * for request stacking support until then.
1641 *
1642 * This queue is new, so no concurrency on the queue_flags.
1643 */
1644 queue_flag_clear_unlocked(QUEUE_FLAG_STACKABLE, md->queue);
1645
1646 /*
1647 * Initialize data that will only be used by a non-blk-mq DM queue
1648 * - must do so here (in alloc_dev callchain) before queue is used
1649 */
1650 md->queue->queuedata = md;
1651}
1652
1653void dm_init_normal_md_queue(struct mapped_device *md)
1654{
1655 md->use_blk_mq = false;
1656 dm_init_md_queue(md);
1657
1658 /*
1659 * Initialize aspects of queue that aren't relevant for blk-mq
1660 */
1661 md->queue->backing_dev_info->congested_data = md;
1662 md->queue->backing_dev_info->congested_fn = dm_any_congested;
1663}
1664
1665static void cleanup_mapped_device(struct mapped_device *md)
1666{
1667 if (md->wq)
1668 destroy_workqueue(md->wq);
1669 if (md->kworker_task)
1670 kthread_stop(md->kworker_task);
1671 mempool_destroy(md->io_pool);
1672 if (md->bs)
1673 bioset_free(md->bs);
1674
1675 if (md->dax_dev) {
1676 kill_dax(md->dax_dev);
1677 put_dax(md->dax_dev);
1678 md->dax_dev = NULL;
1679 }
1680
1681 if (md->disk) {
1682 spin_lock(&_minor_lock);
1683 md->disk->private_data = NULL;
1684 spin_unlock(&_minor_lock);
1685 del_gendisk(md->disk);
1686 put_disk(md->disk);
1687 }
1688
1689 if (md->queue)
1690 blk_cleanup_queue(md->queue);
1691
1692 cleanup_srcu_struct(&md->io_barrier);
1693
1694 if (md->bdev) {
1695 bdput(md->bdev);
1696 md->bdev = NULL;
1697 }
1698
1699 dm_mq_cleanup_mapped_device(md);
1700}
1701
1702/*
1703 * Allocate and initialise a blank device with a given minor.
1704 */
1705static struct mapped_device *alloc_dev(int minor)
1706{
1707 int r, numa_node_id = dm_get_numa_node();
1708 struct dax_device *dax_dev;
1709 struct mapped_device *md;
1710 void *old_md;
1711
1712 md = kvzalloc_node(sizeof(*md), GFP_KERNEL, numa_node_id);
1713 if (!md) {
1714 DMWARN("unable to allocate device, out of memory.");
1715 return NULL;
1716 }
1717
1718 if (!try_module_get(THIS_MODULE))
1719 goto bad_module_get;
1720
1721 /* get a minor number for the dev */
1722 if (minor == DM_ANY_MINOR)
1723 r = next_free_minor(&minor);
1724 else
1725 r = specific_minor(minor);
1726 if (r < 0)
1727 goto bad_minor;
1728
1729 r = init_srcu_struct(&md->io_barrier);
1730 if (r < 0)
1731 goto bad_io_barrier;
1732
1733 md->numa_node_id = numa_node_id;
1734 md->use_blk_mq = dm_use_blk_mq_default();
1735 md->init_tio_pdu = false;
1736 md->type = DM_TYPE_NONE;
1737 mutex_init(&md->suspend_lock);
1738 mutex_init(&md->type_lock);
1739 mutex_init(&md->table_devices_lock);
1740 spin_lock_init(&md->deferred_lock);
1741 atomic_set(&md->holders, 1);
1742 atomic_set(&md->open_count, 0);
1743 atomic_set(&md->event_nr, 0);
1744 atomic_set(&md->uevent_seq, 0);
1745 INIT_LIST_HEAD(&md->uevent_list);
1746 INIT_LIST_HEAD(&md->table_devices);
1747 spin_lock_init(&md->uevent_lock);
1748
1749 md->queue = blk_alloc_queue_node(GFP_KERNEL, numa_node_id);
1750 if (!md->queue)
1751 goto bad;
1752
1753 dm_init_md_queue(md);
1754 /*
1755 * default to bio-based required ->make_request_fn until DM
1756 * table is loaded and md->type established. If request-based
1757 * table is loaded: blk-mq will override accordingly.
1758 */
1759 blk_queue_make_request(md->queue, dm_make_request);
1760
1761 md->disk = alloc_disk_node(1, numa_node_id);
1762 if (!md->disk)
1763 goto bad;
1764
1765 atomic_set(&md->pending[0], 0);
1766 atomic_set(&md->pending[1], 0);
1767 init_waitqueue_head(&md->wait);
1768 INIT_WORK(&md->work, dm_wq_work);
1769 init_waitqueue_head(&md->eventq);
1770 init_completion(&md->kobj_holder.completion);
1771 md->kworker_task = NULL;
1772
1773 md->disk->major = _major;
1774 md->disk->first_minor = minor;
1775 md->disk->fops = &dm_blk_dops;
1776 md->disk->queue = md->queue;
1777 md->disk->private_data = md;
1778 sprintf(md->disk->disk_name, "dm-%d", minor);
1779
1780 dax_dev = alloc_dax(md, md->disk->disk_name, &dm_dax_ops);
1781 if (!dax_dev)
1782 goto bad;
1783 md->dax_dev = dax_dev;
1784
1785 add_disk(md->disk);
1786 format_dev_t(md->name, MKDEV(_major, minor));
1787
1788 md->wq = alloc_workqueue("kdmflush", WQ_MEM_RECLAIM, 0);
1789 if (!md->wq)
1790 goto bad;
1791
1792 md->bdev = bdget_disk(md->disk, 0);
1793 if (!md->bdev)
1794 goto bad;
1795
1796 bio_init(&md->flush_bio, NULL, 0);
1797 bio_set_dev(&md->flush_bio, md->bdev);
1798 md->flush_bio.bi_opf = REQ_OP_WRITE | REQ_PREFLUSH | REQ_SYNC;
1799
1800 dm_stats_init(&md->stats);
1801
1802 /* Populate the mapping, nobody knows we exist yet */
1803 spin_lock(&_minor_lock);
1804 old_md = idr_replace(&_minor_idr, md, minor);
1805 spin_unlock(&_minor_lock);
1806
1807 BUG_ON(old_md != MINOR_ALLOCED);
1808
1809 return md;
1810
1811bad:
1812 cleanup_mapped_device(md);
1813bad_io_barrier:
1814 free_minor(minor);
1815bad_minor:
1816 module_put(THIS_MODULE);
1817bad_module_get:
1818 kvfree(md);
1819 return NULL;
1820}
1821
1822static void unlock_fs(struct mapped_device *md);
1823
1824static void free_dev(struct mapped_device *md)
1825{
1826 int minor = MINOR(disk_devt(md->disk));
1827
1828 unlock_fs(md);
1829
1830 cleanup_mapped_device(md);
1831
1832 free_table_devices(&md->table_devices);
1833 dm_stats_cleanup(&md->stats);
1834 free_minor(minor);
1835
1836 module_put(THIS_MODULE);
1837 kvfree(md);
1838}
1839
1840static void __bind_mempools(struct mapped_device *md, struct dm_table *t)
1841{
1842 struct dm_md_mempools *p = dm_table_get_md_mempools(t);
1843
1844 if (md->bs) {
1845 /* The md already has necessary mempools. */
1846 if (dm_table_bio_based(t)) {
1847 /*
1848 * Reload bioset because front_pad may have changed
1849 * because a different table was loaded.
1850 */
1851 bioset_free(md->bs);
1852 md->bs = p->bs;
1853 p->bs = NULL;
1854 }
1855 /*
1856 * There's no need to reload with request-based dm
1857 * because the size of front_pad doesn't change.
1858 * Note for future: If you are to reload bioset,
1859 * prep-ed requests in the queue may refer
1860 * to bio from the old bioset, so you must walk
1861 * through the queue to unprep.
1862 */
1863 goto out;
1864 }
1865
1866 BUG_ON(!p || md->io_pool || md->bs);
1867
1868 md->io_pool = p->io_pool;
1869 p->io_pool = NULL;
1870 md->bs = p->bs;
1871 p->bs = NULL;
1872
1873out:
1874 /* mempool bind completed, no longer need any mempools in the table */
1875 dm_table_free_md_mempools(t);
1876}
1877
1878/*
1879 * Bind a table to the device.
1880 */
1881static void event_callback(void *context)
1882{
1883 unsigned long flags;
1884 LIST_HEAD(uevents);
1885 struct mapped_device *md = (struct mapped_device *) context;
1886
1887 spin_lock_irqsave(&md->uevent_lock, flags);
1888 list_splice_init(&md->uevent_list, &uevents);
1889 spin_unlock_irqrestore(&md->uevent_lock, flags);
1890
1891 dm_send_uevents(&uevents, &disk_to_dev(md->disk)->kobj);
1892
1893 atomic_inc(&md->event_nr);
1894 wake_up(&md->eventq);
1895 dm_issue_global_event();
1896}
1897
1898/*
1899 * Protected by md->suspend_lock obtained by dm_swap_table().
1900 */
1901static void __set_size(struct mapped_device *md, sector_t size)
1902{
1903 lockdep_assert_held(&md->suspend_lock);
1904
1905 set_capacity(md->disk, size);
1906
1907 i_size_write(md->bdev->bd_inode, (loff_t)size << SECTOR_SHIFT);
1908}
1909
1910/*
1911 * Returns old map, which caller must destroy.
1912 */
1913static struct dm_table *__bind(struct mapped_device *md, struct dm_table *t,
1914 struct queue_limits *limits)
1915{
1916 struct dm_table *old_map;
1917 struct request_queue *q = md->queue;
1918 sector_t size;
1919
1920 lockdep_assert_held(&md->suspend_lock);
1921
1922 size = dm_table_get_size(t);
1923
1924 /*
1925 * Wipe any geometry if the size of the table changed.
1926 */
1927 if (size != dm_get_size(md))
1928 memset(&md->geometry, 0, sizeof(md->geometry));
1929
1930 __set_size(md, size);
1931
1932 dm_table_event_callback(t, event_callback, md);
1933
1934 /*
1935 * The queue hasn't been stopped yet, if the old table type wasn't
1936 * for request-based during suspension. So stop it to prevent
1937 * I/O mapping before resume.
1938 * This must be done before setting the queue restrictions,
1939 * because request-based dm may be run just after the setting.
1940 */
1941 if (dm_table_request_based(t)) {
1942 dm_stop_queue(q);
1943 /*
1944 * Leverage the fact that request-based DM targets are
1945 * immutable singletons and establish md->immutable_target
1946 * - used to optimize both dm_request_fn and dm_mq_queue_rq
1947 */
1948 md->immutable_target = dm_table_get_immutable_target(t);
1949 }
1950
1951 __bind_mempools(md, t);
1952
1953 old_map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock));
1954 rcu_assign_pointer(md->map, (void *)t);
1955 md->immutable_target_type = dm_table_get_immutable_target_type(t);
1956
1957 dm_table_set_restrictions(t, q, limits);
1958 if (old_map)
1959 dm_sync_table(md);
1960
1961 return old_map;
1962}
1963
1964/*
1965 * Returns unbound table for the caller to free.
1966 */
1967static struct dm_table *__unbind(struct mapped_device *md)
1968{
1969 struct dm_table *map = rcu_dereference_protected(md->map, 1);
1970
1971 if (!map)
1972 return NULL;
1973
1974 dm_table_event_callback(map, NULL, NULL);
1975 RCU_INIT_POINTER(md->map, NULL);
1976 dm_sync_table(md);
1977
1978 return map;
1979}
1980
1981/*
1982 * Constructor for a new device.
1983 */
1984int dm_create(int minor, struct mapped_device **result)
1985{
1986 struct mapped_device *md;
1987
1988 md = alloc_dev(minor);
1989 if (!md)
1990 return -ENXIO;
1991
1992 dm_sysfs_init(md);
1993
1994 *result = md;
1995 return 0;
1996}
1997
1998/*
1999 * Functions to manage md->type.
2000 * All are required to hold md->type_lock.
2001 */
2002void dm_lock_md_type(struct mapped_device *md)
2003{
2004 mutex_lock(&md->type_lock);
2005}
2006
2007void dm_unlock_md_type(struct mapped_device *md)
2008{
2009 mutex_unlock(&md->type_lock);
2010}
2011
2012void dm_set_md_type(struct mapped_device *md, enum dm_queue_mode type)
2013{
2014 BUG_ON(!mutex_is_locked(&md->type_lock));
2015 md->type = type;
2016}
2017
2018enum dm_queue_mode dm_get_md_type(struct mapped_device *md)
2019{
2020 return md->type;
2021}
2022
2023struct target_type *dm_get_immutable_target_type(struct mapped_device *md)
2024{
2025 return md->immutable_target_type;
2026}
2027
2028/*
2029 * The queue_limits are only valid as long as you have a reference
2030 * count on 'md'.
2031 */
2032struct queue_limits *dm_get_queue_limits(struct mapped_device *md)
2033{
2034 BUG_ON(!atomic_read(&md->holders));
2035 return &md->queue->limits;
2036}
2037EXPORT_SYMBOL_GPL(dm_get_queue_limits);
2038
2039/*
2040 * Setup the DM device's queue based on md's type
2041 */
2042int dm_setup_md_queue(struct mapped_device *md, struct dm_table *t)
2043{
2044 int r;
2045 enum dm_queue_mode type = dm_get_md_type(md);
2046
2047 switch (type) {
2048 case DM_TYPE_REQUEST_BASED:
2049 r = dm_old_init_request_queue(md, t);
2050 if (r) {
2051 DMERR("Cannot initialize queue for request-based mapped device");
2052 return r;
2053 }
2054 break;
2055 case DM_TYPE_MQ_REQUEST_BASED:
2056 r = dm_mq_init_request_queue(md, t);
2057 if (r) {
2058 DMERR("Cannot initialize queue for request-based dm-mq mapped device");
2059 return r;
2060 }
2061 break;
2062 case DM_TYPE_BIO_BASED:
2063 case DM_TYPE_DAX_BIO_BASED:
2064 dm_init_normal_md_queue(md);
2065 /*
2066 * DM handles splitting bios as needed. Free the bio_split bioset
2067 * since it won't be used (saves 1 process per bio-based DM device).
2068 */
2069 bioset_free(md->queue->bio_split);
2070 md->queue->bio_split = NULL;
2071 break;
2072 case DM_TYPE_NONE:
2073 WARN_ON_ONCE(true);
2074 break;
2075 }
2076
2077 return 0;
2078}
2079
2080struct mapped_device *dm_get_md(dev_t dev)
2081{
2082 struct mapped_device *md;
2083 unsigned minor = MINOR(dev);
2084
2085 if (MAJOR(dev) != _major || minor >= (1 << MINORBITS))
2086 return NULL;
2087
2088 spin_lock(&_minor_lock);
2089
2090 md = idr_find(&_minor_idr, minor);
2091 if (md) {
2092 if ((md == MINOR_ALLOCED ||
2093 (MINOR(disk_devt(dm_disk(md))) != minor) ||
2094 dm_deleting_md(md) ||
2095 test_bit(DMF_FREEING, &md->flags))) {
2096 md = NULL;
2097 goto out;
2098 }
2099 dm_get(md);
2100 }
2101
2102out:
2103 spin_unlock(&_minor_lock);
2104
2105 return md;
2106}
2107EXPORT_SYMBOL_GPL(dm_get_md);
2108
2109void *dm_get_mdptr(struct mapped_device *md)
2110{
2111 return md->interface_ptr;
2112}
2113
2114void dm_set_mdptr(struct mapped_device *md, void *ptr)
2115{
2116 md->interface_ptr = ptr;
2117}
2118
2119void dm_get(struct mapped_device *md)
2120{
2121 atomic_inc(&md->holders);
2122 BUG_ON(test_bit(DMF_FREEING, &md->flags));
2123}
2124
2125int dm_hold(struct mapped_device *md)
2126{
2127 spin_lock(&_minor_lock);
2128 if (test_bit(DMF_FREEING, &md->flags)) {
2129 spin_unlock(&_minor_lock);
2130 return -EBUSY;
2131 }
2132 dm_get(md);
2133 spin_unlock(&_minor_lock);
2134 return 0;
2135}
2136EXPORT_SYMBOL_GPL(dm_hold);
2137
2138const char *dm_device_name(struct mapped_device *md)
2139{
2140 return md->name;
2141}
2142EXPORT_SYMBOL_GPL(dm_device_name);
2143
2144static void __dm_destroy(struct mapped_device *md, bool wait)
2145{
2146 struct request_queue *q = dm_get_md_queue(md);
2147 struct dm_table *map;
2148 int srcu_idx;
2149
2150 might_sleep();
2151
2152 spin_lock(&_minor_lock);
2153 idr_replace(&_minor_idr, MINOR_ALLOCED, MINOR(disk_devt(dm_disk(md))));
2154 set_bit(DMF_FREEING, &md->flags);
2155 spin_unlock(&_minor_lock);
2156
2157 blk_set_queue_dying(q);
2158
2159 if (dm_request_based(md) && md->kworker_task)
2160 kthread_flush_worker(&md->kworker);
2161
2162 /*
2163 * Take suspend_lock so that presuspend and postsuspend methods
2164 * do not race with internal suspend.
2165 */
2166 mutex_lock(&md->suspend_lock);
2167 map = dm_get_live_table(md, &srcu_idx);
2168 if (!dm_suspended_md(md)) {
2169 dm_table_presuspend_targets(map);
2170 dm_table_postsuspend_targets(map);
2171 }
2172 /* dm_put_live_table must be before msleep, otherwise deadlock is possible */
2173 dm_put_live_table(md, srcu_idx);
2174 mutex_unlock(&md->suspend_lock);
2175
2176 /*
2177 * Rare, but there may be I/O requests still going to complete,
2178 * for example. Wait for all references to disappear.
2179 * No one should increment the reference count of the mapped_device,
2180 * after the mapped_device state becomes DMF_FREEING.
2181 */
2182 if (wait)
2183 while (atomic_read(&md->holders))
2184 msleep(1);
2185 else if (atomic_read(&md->holders))
2186 DMWARN("%s: Forcibly removing mapped_device still in use! (%d users)",
2187 dm_device_name(md), atomic_read(&md->holders));
2188
2189 dm_sysfs_exit(md);
2190 dm_table_destroy(__unbind(md));
2191 free_dev(md);
2192}
2193
2194void dm_destroy(struct mapped_device *md)
2195{
2196 __dm_destroy(md, true);
2197}
2198
2199void dm_destroy_immediate(struct mapped_device *md)
2200{
2201 __dm_destroy(md, false);
2202}
2203
2204void dm_put(struct mapped_device *md)
2205{
2206 atomic_dec(&md->holders);
2207}
2208EXPORT_SYMBOL_GPL(dm_put);
2209
2210static int dm_wait_for_completion(struct mapped_device *md, long task_state)
2211{
2212 int r = 0;
2213 DEFINE_WAIT(wait);
2214
2215 while (1) {
2216 prepare_to_wait(&md->wait, &wait, task_state);
2217
2218 if (!md_in_flight(md))
2219 break;
2220
2221 if (signal_pending_state(task_state, current)) {
2222 r = -EINTR;
2223 break;
2224 }
2225
2226 io_schedule();
2227 }
2228 finish_wait(&md->wait, &wait);
2229
2230 return r;
2231}
2232
2233/*
2234 * Process the deferred bios
2235 */
2236static void dm_wq_work(struct work_struct *work)
2237{
2238 struct mapped_device *md = container_of(work, struct mapped_device,
2239 work);
2240 struct bio *c;
2241 int srcu_idx;
2242 struct dm_table *map;
2243
2244 map = dm_get_live_table(md, &srcu_idx);
2245
2246 while (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) {
2247 spin_lock_irq(&md->deferred_lock);
2248 c = bio_list_pop(&md->deferred);
2249 spin_unlock_irq(&md->deferred_lock);
2250
2251 if (!c)
2252 break;
2253
2254 if (dm_request_based(md))
2255 generic_make_request(c);
2256 else
2257 __split_and_process_bio(md, map, c);
2258 }
2259
2260 dm_put_live_table(md, srcu_idx);
2261}
2262
2263static void dm_queue_flush(struct mapped_device *md)
2264{
2265 clear_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags);
2266 smp_mb__after_atomic();
2267 queue_work(md->wq, &md->work);
2268}
2269
2270/*
2271 * Swap in a new table, returning the old one for the caller to destroy.
2272 */
2273struct dm_table *dm_swap_table(struct mapped_device *md, struct dm_table *table)
2274{
2275 struct dm_table *live_map = NULL, *map = ERR_PTR(-EINVAL);
2276 struct queue_limits limits;
2277 int r;
2278
2279 mutex_lock(&md->suspend_lock);
2280
2281 /* device must be suspended */
2282 if (!dm_suspended_md(md))
2283 goto out;
2284
2285 /*
2286 * If the new table has no data devices, retain the existing limits.
2287 * This helps multipath with queue_if_no_path if all paths disappear,
2288 * then new I/O is queued based on these limits, and then some paths
2289 * reappear.
2290 */
2291 if (dm_table_has_no_data_devices(table)) {
2292 live_map = dm_get_live_table_fast(md);
2293 if (live_map)
2294 limits = md->queue->limits;
2295 dm_put_live_table_fast(md);
2296 }
2297
2298 if (!live_map) {
2299 r = dm_calculate_queue_limits(table, &limits);
2300 if (r) {
2301 map = ERR_PTR(r);
2302 goto out;
2303 }
2304 }
2305
2306 map = __bind(md, table, &limits);
2307 dm_issue_global_event();
2308
2309out:
2310 mutex_unlock(&md->suspend_lock);
2311 return map;
2312}
2313
2314/*
2315 * Functions to lock and unlock any filesystem running on the
2316 * device.
2317 */
2318static int lock_fs(struct mapped_device *md)
2319{
2320 int r;
2321
2322 WARN_ON(md->frozen_sb);
2323
2324 md->frozen_sb = freeze_bdev(md->bdev);
2325 if (IS_ERR(md->frozen_sb)) {
2326 r = PTR_ERR(md->frozen_sb);
2327 md->frozen_sb = NULL;
2328 return r;
2329 }
2330
2331 set_bit(DMF_FROZEN, &md->flags);
2332
2333 return 0;
2334}
2335
2336static void unlock_fs(struct mapped_device *md)
2337{
2338 if (!test_bit(DMF_FROZEN, &md->flags))
2339 return;
2340
2341 thaw_bdev(md->bdev, md->frozen_sb);
2342 md->frozen_sb = NULL;
2343 clear_bit(DMF_FROZEN, &md->flags);
2344}
2345
2346/*
2347 * @suspend_flags: DM_SUSPEND_LOCKFS_FLAG and/or DM_SUSPEND_NOFLUSH_FLAG
2348 * @task_state: e.g. TASK_INTERRUPTIBLE or TASK_UNINTERRUPTIBLE
2349 * @dmf_suspended_flag: DMF_SUSPENDED or DMF_SUSPENDED_INTERNALLY
2350 *
2351 * If __dm_suspend returns 0, the device is completely quiescent
2352 * now. There is no request-processing activity. All new requests
2353 * are being added to md->deferred list.
2354 */
2355static int __dm_suspend(struct mapped_device *md, struct dm_table *map,
2356 unsigned suspend_flags, long task_state,
2357 int dmf_suspended_flag)
2358{
2359 bool do_lockfs = suspend_flags & DM_SUSPEND_LOCKFS_FLAG;
2360 bool noflush = suspend_flags & DM_SUSPEND_NOFLUSH_FLAG;
2361 int r;
2362
2363 lockdep_assert_held(&md->suspend_lock);
2364
2365 /*
2366 * DMF_NOFLUSH_SUSPENDING must be set before presuspend.
2367 * This flag is cleared before dm_suspend returns.
2368 */
2369 if (noflush)
2370 set_bit(DMF_NOFLUSH_SUSPENDING, &md->flags);
2371 else
2372 pr_debug("%s: suspending with flush\n", dm_device_name(md));
2373
2374 /*
2375 * This gets reverted if there's an error later and the targets
2376 * provide the .presuspend_undo hook.
2377 */
2378 dm_table_presuspend_targets(map);
2379
2380 /*
2381 * Flush I/O to the device.
2382 * Any I/O submitted after lock_fs() may not be flushed.
2383 * noflush takes precedence over do_lockfs.
2384 * (lock_fs() flushes I/Os and waits for them to complete.)
2385 */
2386 if (!noflush && do_lockfs) {
2387 r = lock_fs(md);
2388 if (r) {
2389 dm_table_presuspend_undo_targets(map);
2390 return r;
2391 }
2392 }
2393
2394 /*
2395 * Here we must make sure that no processes are submitting requests
2396 * to target drivers i.e. no one may be executing
2397 * __split_and_process_bio. This is called from dm_request and
2398 * dm_wq_work.
2399 *
2400 * To get all processes out of __split_and_process_bio in dm_request,
2401 * we take the write lock. To prevent any process from reentering
2402 * __split_and_process_bio from dm_request and quiesce the thread
2403 * (dm_wq_work), we set BMF_BLOCK_IO_FOR_SUSPEND and call
2404 * flush_workqueue(md->wq).
2405 */
2406 set_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags);
2407 if (map)
2408 synchronize_srcu(&md->io_barrier);
2409
2410 /*
2411 * Stop md->queue before flushing md->wq in case request-based
2412 * dm defers requests to md->wq from md->queue.
2413 */
2414 if (dm_request_based(md)) {
2415 dm_stop_queue(md->queue);
2416 if (md->kworker_task)
2417 kthread_flush_worker(&md->kworker);
2418 }
2419
2420 flush_workqueue(md->wq);
2421
2422 /*
2423 * At this point no more requests are entering target request routines.
2424 * We call dm_wait_for_completion to wait for all existing requests
2425 * to finish.
2426 */
2427 r = dm_wait_for_completion(md, task_state);
2428 if (!r)
2429 set_bit(dmf_suspended_flag, &md->flags);
2430
2431 if (noflush)
2432 clear_bit(DMF_NOFLUSH_SUSPENDING, &md->flags);
2433 if (map)
2434 synchronize_srcu(&md->io_barrier);
2435
2436 /* were we interrupted ? */
2437 if (r < 0) {
2438 dm_queue_flush(md);
2439
2440 if (dm_request_based(md))
2441 dm_start_queue(md->queue);
2442
2443 unlock_fs(md);
2444 dm_table_presuspend_undo_targets(map);
2445 /* pushback list is already flushed, so skip flush */
2446 }
2447
2448 return r;
2449}
2450
2451/*
2452 * We need to be able to change a mapping table under a mounted
2453 * filesystem. For example we might want to move some data in
2454 * the background. Before the table can be swapped with
2455 * dm_bind_table, dm_suspend must be called to flush any in
2456 * flight bios and ensure that any further io gets deferred.
2457 */
2458/*
2459 * Suspend mechanism in request-based dm.
2460 *
2461 * 1. Flush all I/Os by lock_fs() if needed.
2462 * 2. Stop dispatching any I/O by stopping the request_queue.
2463 * 3. Wait for all in-flight I/Os to be completed or requeued.
2464 *
2465 * To abort suspend, start the request_queue.
2466 */
2467int dm_suspend(struct mapped_device *md, unsigned suspend_flags)
2468{
2469 struct dm_table *map = NULL;
2470 int r = 0;
2471
2472retry:
2473 mutex_lock_nested(&md->suspend_lock, SINGLE_DEPTH_NESTING);
2474
2475 if (dm_suspended_md(md)) {
2476 r = -EINVAL;
2477 goto out_unlock;
2478 }
2479
2480 if (dm_suspended_internally_md(md)) {
2481 /* already internally suspended, wait for internal resume */
2482 mutex_unlock(&md->suspend_lock);
2483 r = wait_on_bit(&md->flags, DMF_SUSPENDED_INTERNALLY, TASK_INTERRUPTIBLE);
2484 if (r)
2485 return r;
2486 goto retry;
2487 }
2488
2489 map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock));
2490
2491 r = __dm_suspend(md, map, suspend_flags, TASK_INTERRUPTIBLE, DMF_SUSPENDED);
2492 if (r)
2493 goto out_unlock;
2494
2495 dm_table_postsuspend_targets(map);
2496
2497out_unlock:
2498 mutex_unlock(&md->suspend_lock);
2499 return r;
2500}
2501
2502static int __dm_resume(struct mapped_device *md, struct dm_table *map)
2503{
2504 if (map) {
2505 int r = dm_table_resume_targets(map);
2506 if (r)
2507 return r;
2508 }
2509
2510 dm_queue_flush(md);
2511
2512 /*
2513 * Flushing deferred I/Os must be done after targets are resumed
2514 * so that mapping of targets can work correctly.
2515 * Request-based dm is queueing the deferred I/Os in its request_queue.
2516 */
2517 if (dm_request_based(md))
2518 dm_start_queue(md->queue);
2519
2520 unlock_fs(md);
2521
2522 return 0;
2523}
2524
2525int dm_resume(struct mapped_device *md)
2526{
2527 int r;
2528 struct dm_table *map = NULL;
2529
2530retry:
2531 r = -EINVAL;
2532 mutex_lock_nested(&md->suspend_lock, SINGLE_DEPTH_NESTING);
2533
2534 if (!dm_suspended_md(md))
2535 goto out;
2536
2537 if (dm_suspended_internally_md(md)) {
2538 /* already internally suspended, wait for internal resume */
2539 mutex_unlock(&md->suspend_lock);
2540 r = wait_on_bit(&md->flags, DMF_SUSPENDED_INTERNALLY, TASK_INTERRUPTIBLE);
2541 if (r)
2542 return r;
2543 goto retry;
2544 }
2545
2546 map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock));
2547 if (!map || !dm_table_get_size(map))
2548 goto out;
2549
2550 r = __dm_resume(md, map);
2551 if (r)
2552 goto out;
2553
2554 clear_bit(DMF_SUSPENDED, &md->flags);
2555out:
2556 mutex_unlock(&md->suspend_lock);
2557
2558 return r;
2559}
2560
2561/*
2562 * Internal suspend/resume works like userspace-driven suspend. It waits
2563 * until all bios finish and prevents issuing new bios to the target drivers.
2564 * It may be used only from the kernel.
2565 */
2566
2567static void __dm_internal_suspend(struct mapped_device *md, unsigned suspend_flags)
2568{
2569 struct dm_table *map = NULL;
2570
2571 lockdep_assert_held(&md->suspend_lock);
2572
2573 if (md->internal_suspend_count++)
2574 return; /* nested internal suspend */
2575
2576 if (dm_suspended_md(md)) {
2577 set_bit(DMF_SUSPENDED_INTERNALLY, &md->flags);
2578 return; /* nest suspend */
2579 }
2580
2581 map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock));
2582
2583 /*
2584 * Using TASK_UNINTERRUPTIBLE because only NOFLUSH internal suspend is
2585 * supported. Properly supporting a TASK_INTERRUPTIBLE internal suspend
2586 * would require changing .presuspend to return an error -- avoid this
2587 * until there is a need for more elaborate variants of internal suspend.
2588 */
2589 (void) __dm_suspend(md, map, suspend_flags, TASK_UNINTERRUPTIBLE,
2590 DMF_SUSPENDED_INTERNALLY);
2591
2592 dm_table_postsuspend_targets(map);
2593}
2594
2595static void __dm_internal_resume(struct mapped_device *md)
2596{
2597 BUG_ON(!md->internal_suspend_count);
2598
2599 if (--md->internal_suspend_count)
2600 return; /* resume from nested internal suspend */
2601
2602 if (dm_suspended_md(md))
2603 goto done; /* resume from nested suspend */
2604
2605 /*
2606 * NOTE: existing callers don't need to call dm_table_resume_targets
2607 * (which may fail -- so best to avoid it for now by passing NULL map)
2608 */
2609 (void) __dm_resume(md, NULL);
2610
2611done:
2612 clear_bit(DMF_SUSPENDED_INTERNALLY, &md->flags);
2613 smp_mb__after_atomic();
2614 wake_up_bit(&md->flags, DMF_SUSPENDED_INTERNALLY);
2615}
2616
2617void dm_internal_suspend_noflush(struct mapped_device *md)
2618{
2619 mutex_lock(&md->suspend_lock);
2620 __dm_internal_suspend(md, DM_SUSPEND_NOFLUSH_FLAG);
2621 mutex_unlock(&md->suspend_lock);
2622}
2623EXPORT_SYMBOL_GPL(dm_internal_suspend_noflush);
2624
2625void dm_internal_resume(struct mapped_device *md)
2626{
2627 mutex_lock(&md->suspend_lock);
2628 __dm_internal_resume(md);
2629 mutex_unlock(&md->suspend_lock);
2630}
2631EXPORT_SYMBOL_GPL(dm_internal_resume);
2632
2633/*
2634 * Fast variants of internal suspend/resume hold md->suspend_lock,
2635 * which prevents interaction with userspace-driven suspend.
2636 */
2637
2638void dm_internal_suspend_fast(struct mapped_device *md)
2639{
2640 mutex_lock(&md->suspend_lock);
2641 if (dm_suspended_md(md) || dm_suspended_internally_md(md))
2642 return;
2643
2644 set_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags);
2645 synchronize_srcu(&md->io_barrier);
2646 flush_workqueue(md->wq);
2647 dm_wait_for_completion(md, TASK_UNINTERRUPTIBLE);
2648}
2649EXPORT_SYMBOL_GPL(dm_internal_suspend_fast);
2650
2651void dm_internal_resume_fast(struct mapped_device *md)
2652{
2653 if (dm_suspended_md(md) || dm_suspended_internally_md(md))
2654 goto done;
2655
2656 dm_queue_flush(md);
2657
2658done:
2659 mutex_unlock(&md->suspend_lock);
2660}
2661EXPORT_SYMBOL_GPL(dm_internal_resume_fast);
2662
2663/*-----------------------------------------------------------------
2664 * Event notification.
2665 *---------------------------------------------------------------*/
2666int dm_kobject_uevent(struct mapped_device *md, enum kobject_action action,
2667 unsigned cookie)
2668{
2669 int r;
2670 unsigned noio_flag;
2671 char udev_cookie[DM_COOKIE_LENGTH];
2672 char *envp[] = { udev_cookie, NULL };
2673
2674 noio_flag = memalloc_noio_save();
2675
2676 if (!cookie)
2677 r = kobject_uevent(&disk_to_dev(md->disk)->kobj, action);
2678 else {
2679 snprintf(udev_cookie, DM_COOKIE_LENGTH, "%s=%u",
2680 DM_COOKIE_ENV_VAR_NAME, cookie);
2681 r = kobject_uevent_env(&disk_to_dev(md->disk)->kobj,
2682 action, envp);
2683 }
2684
2685 memalloc_noio_restore(noio_flag);
2686
2687 return r;
2688}
2689
2690uint32_t dm_next_uevent_seq(struct mapped_device *md)
2691{
2692 return atomic_add_return(1, &md->uevent_seq);
2693}
2694
2695uint32_t dm_get_event_nr(struct mapped_device *md)
2696{
2697 return atomic_read(&md->event_nr);
2698}
2699
2700int dm_wait_event(struct mapped_device *md, int event_nr)
2701{
2702 return wait_event_interruptible(md->eventq,
2703 (event_nr != atomic_read(&md->event_nr)));
2704}
2705
2706void dm_uevent_add(struct mapped_device *md, struct list_head *elist)
2707{
2708 unsigned long flags;
2709
2710 spin_lock_irqsave(&md->uevent_lock, flags);
2711 list_add(elist, &md->uevent_list);
2712 spin_unlock_irqrestore(&md->uevent_lock, flags);
2713}
2714
2715/*
2716 * The gendisk is only valid as long as you have a reference
2717 * count on 'md'.
2718 */
2719struct gendisk *dm_disk(struct mapped_device *md)
2720{
2721 return md->disk;
2722}
2723EXPORT_SYMBOL_GPL(dm_disk);
2724
2725struct kobject *dm_kobject(struct mapped_device *md)
2726{
2727 return &md->kobj_holder.kobj;
2728}
2729
2730struct mapped_device *dm_get_from_kobject(struct kobject *kobj)
2731{
2732 struct mapped_device *md;
2733
2734 md = container_of(kobj, struct mapped_device, kobj_holder.kobj);
2735
2736 spin_lock(&_minor_lock);
2737 if (test_bit(DMF_FREEING, &md->flags) || dm_deleting_md(md)) {
2738 md = NULL;
2739 goto out;
2740 }
2741 dm_get(md);
2742out:
2743 spin_unlock(&_minor_lock);
2744
2745 return md;
2746}
2747
2748int dm_suspended_md(struct mapped_device *md)
2749{
2750 return test_bit(DMF_SUSPENDED, &md->flags);
2751}
2752
2753int dm_suspended_internally_md(struct mapped_device *md)
2754{
2755 return test_bit(DMF_SUSPENDED_INTERNALLY, &md->flags);
2756}
2757
2758int dm_test_deferred_remove_flag(struct mapped_device *md)
2759{
2760 return test_bit(DMF_DEFERRED_REMOVE, &md->flags);
2761}
2762
2763int dm_suspended(struct dm_target *ti)
2764{
2765 return dm_suspended_md(dm_table_get_md(ti->table));
2766}
2767EXPORT_SYMBOL_GPL(dm_suspended);
2768
2769int dm_noflush_suspending(struct dm_target *ti)
2770{
2771 return __noflush_suspending(dm_table_get_md(ti->table));
2772}
2773EXPORT_SYMBOL_GPL(dm_noflush_suspending);
2774
2775struct dm_md_mempools *dm_alloc_md_mempools(struct mapped_device *md, enum dm_queue_mode type,
2776 unsigned integrity, unsigned per_io_data_size)
2777{
2778 struct dm_md_mempools *pools = kzalloc_node(sizeof(*pools), GFP_KERNEL, md->numa_node_id);
2779 unsigned int pool_size = 0;
2780 unsigned int front_pad;
2781
2782 if (!pools)
2783 return NULL;
2784
2785 switch (type) {
2786 case DM_TYPE_BIO_BASED:
2787 case DM_TYPE_DAX_BIO_BASED:
2788 pool_size = dm_get_reserved_bio_based_ios();
2789 front_pad = roundup(per_io_data_size, __alignof__(struct dm_target_io)) + offsetof(struct dm_target_io, clone);
2790
2791 pools->io_pool = mempool_create_slab_pool(pool_size, _io_cache);
2792 if (!pools->io_pool)
2793 goto out;
2794 break;
2795 case DM_TYPE_REQUEST_BASED:
2796 case DM_TYPE_MQ_REQUEST_BASED:
2797 pool_size = dm_get_reserved_rq_based_ios();
2798 front_pad = offsetof(struct dm_rq_clone_bio_info, clone);
2799 /* per_io_data_size is used for blk-mq pdu at queue allocation */
2800 break;
2801 default:
2802 BUG();
2803 }
2804
2805 pools->bs = bioset_create(pool_size, front_pad, BIOSET_NEED_RESCUER);
2806 if (!pools->bs)
2807 goto out;
2808
2809 if (integrity && bioset_integrity_create(pools->bs, pool_size))
2810 goto out;
2811
2812 return pools;
2813
2814out:
2815 dm_free_md_mempools(pools);
2816
2817 return NULL;
2818}
2819
2820void dm_free_md_mempools(struct dm_md_mempools *pools)
2821{
2822 if (!pools)
2823 return;
2824
2825 mempool_destroy(pools->io_pool);
2826
2827 if (pools->bs)
2828 bioset_free(pools->bs);
2829
2830 kfree(pools);
2831}
2832
2833struct dm_pr {
2834 u64 old_key;
2835 u64 new_key;
2836 u32 flags;
2837 bool fail_early;
2838};
2839
2840static int dm_call_pr(struct block_device *bdev, iterate_devices_callout_fn fn,
2841 void *data)
2842{
2843 struct mapped_device *md = bdev->bd_disk->private_data;
2844 struct dm_table *table;
2845 struct dm_target *ti;
2846 int ret = -ENOTTY, srcu_idx;
2847
2848 table = dm_get_live_table(md, &srcu_idx);
2849 if (!table || !dm_table_get_size(table))
2850 goto out;
2851
2852 /* We only support devices that have a single target */
2853 if (dm_table_get_num_targets(table) != 1)
2854 goto out;
2855 ti = dm_table_get_target(table, 0);
2856
2857 ret = -EINVAL;
2858 if (!ti->type->iterate_devices)
2859 goto out;
2860
2861 ret = ti->type->iterate_devices(ti, fn, data);
2862out:
2863 dm_put_live_table(md, srcu_idx);
2864 return ret;
2865}
2866
2867/*
2868 * For register / unregister we need to manually call out to every path.
2869 */
2870static int __dm_pr_register(struct dm_target *ti, struct dm_dev *dev,
2871 sector_t start, sector_t len, void *data)
2872{
2873 struct dm_pr *pr = data;
2874 const struct pr_ops *ops = dev->bdev->bd_disk->fops->pr_ops;
2875
2876 if (!ops || !ops->pr_register)
2877 return -EOPNOTSUPP;
2878 return ops->pr_register(dev->bdev, pr->old_key, pr->new_key, pr->flags);
2879}
2880
2881static int dm_pr_register(struct block_device *bdev, u64 old_key, u64 new_key,
2882 u32 flags)
2883{
2884 struct dm_pr pr = {
2885 .old_key = old_key,
2886 .new_key = new_key,
2887 .flags = flags,
2888 .fail_early = true,
2889 };
2890 int ret;
2891
2892 ret = dm_call_pr(bdev, __dm_pr_register, &pr);
2893 if (ret && new_key) {
2894 /* unregister all paths if we failed to register any path */
2895 pr.old_key = new_key;
2896 pr.new_key = 0;
2897 pr.flags = 0;
2898 pr.fail_early = false;
2899 dm_call_pr(bdev, __dm_pr_register, &pr);
2900 }
2901
2902 return ret;
2903}
2904
2905static int dm_pr_reserve(struct block_device *bdev, u64 key, enum pr_type type,
2906 u32 flags)
2907{
2908 struct mapped_device *md = bdev->bd_disk->private_data;
2909 const struct pr_ops *ops;
2910 fmode_t mode;
2911 int r;
2912
2913 r = dm_grab_bdev_for_ioctl(md, &bdev, &mode);
2914 if (r < 0)
2915 return r;
2916
2917 ops = bdev->bd_disk->fops->pr_ops;
2918 if (ops && ops->pr_reserve)
2919 r = ops->pr_reserve(bdev, key, type, flags);
2920 else
2921 r = -EOPNOTSUPP;
2922
2923 bdput(bdev);
2924 return r;
2925}
2926
2927static int dm_pr_release(struct block_device *bdev, u64 key, enum pr_type type)
2928{
2929 struct mapped_device *md = bdev->bd_disk->private_data;
2930 const struct pr_ops *ops;
2931 fmode_t mode;
2932 int r;
2933
2934 r = dm_grab_bdev_for_ioctl(md, &bdev, &mode);
2935 if (r < 0)
2936 return r;
2937
2938 ops = bdev->bd_disk->fops->pr_ops;
2939 if (ops && ops->pr_release)
2940 r = ops->pr_release(bdev, key, type);
2941 else
2942 r = -EOPNOTSUPP;
2943
2944 bdput(bdev);
2945 return r;
2946}
2947
2948static int dm_pr_preempt(struct block_device *bdev, u64 old_key, u64 new_key,
2949 enum pr_type type, bool abort)
2950{
2951 struct mapped_device *md = bdev->bd_disk->private_data;
2952 const struct pr_ops *ops;
2953 fmode_t mode;
2954 int r;
2955
2956 r = dm_grab_bdev_for_ioctl(md, &bdev, &mode);
2957 if (r < 0)
2958 return r;
2959
2960 ops = bdev->bd_disk->fops->pr_ops;
2961 if (ops && ops->pr_preempt)
2962 r = ops->pr_preempt(bdev, old_key, new_key, type, abort);
2963 else
2964 r = -EOPNOTSUPP;
2965
2966 bdput(bdev);
2967 return r;
2968}
2969
2970static int dm_pr_clear(struct block_device *bdev, u64 key)
2971{
2972 struct mapped_device *md = bdev->bd_disk->private_data;
2973 const struct pr_ops *ops;
2974 fmode_t mode;
2975 int r;
2976
2977 r = dm_grab_bdev_for_ioctl(md, &bdev, &mode);
2978 if (r < 0)
2979 return r;
2980
2981 ops = bdev->bd_disk->fops->pr_ops;
2982 if (ops && ops->pr_clear)
2983 r = ops->pr_clear(bdev, key);
2984 else
2985 r = -EOPNOTSUPP;
2986
2987 bdput(bdev);
2988 return r;
2989}
2990
2991static const struct pr_ops dm_pr_ops = {
2992 .pr_register = dm_pr_register,
2993 .pr_reserve = dm_pr_reserve,
2994 .pr_release = dm_pr_release,
2995 .pr_preempt = dm_pr_preempt,
2996 .pr_clear = dm_pr_clear,
2997};
2998
2999static const struct block_device_operations dm_blk_dops = {
3000 .open = dm_blk_open,
3001 .release = dm_blk_close,
3002 .ioctl = dm_blk_ioctl,
3003 .getgeo = dm_blk_getgeo,
3004 .pr_ops = &dm_pr_ops,
3005 .owner = THIS_MODULE
3006};
3007
3008static const struct dax_operations dm_dax_ops = {
3009 .direct_access = dm_dax_direct_access,
3010 .copy_from_iter = dm_dax_copy_from_iter,
3011};
3012
3013/*
3014 * module hooks
3015 */
3016module_init(dm_init);
3017module_exit(dm_exit);
3018
3019module_param(major, uint, 0);
3020MODULE_PARM_DESC(major, "The major number of the device mapper");
3021
3022module_param(reserved_bio_based_ios, uint, S_IRUGO | S_IWUSR);
3023MODULE_PARM_DESC(reserved_bio_based_ios, "Reserved IOs in bio-based mempools");
3024
3025module_param(dm_numa_node, int, S_IRUGO | S_IWUSR);
3026MODULE_PARM_DESC(dm_numa_node, "NUMA node for DM device memory allocations");
3027
3028MODULE_DESCRIPTION(DM_NAME " driver");
3029MODULE_AUTHOR("Joe Thornber <dm-devel@redhat.com>");
3030MODULE_LICENSE("GPL");