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