1/*
2 * Copyright (C) 2001 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
10#include <linux/module.h>
11#include <linux/vmalloc.h>
12#include <linux/blkdev.h>
13#include <linux/namei.h>
14#include <linux/ctype.h>
15#include <linux/string.h>
16#include <linux/slab.h>
17#include <linux/interrupt.h>
18#include <linux/mutex.h>
19#include <linux/delay.h>
20#include <linux/atomic.h>
21#include <linux/blk-mq.h>
22#include <linux/mount.h>
23#include <linux/dax.h>
24
25#define DM_MSG_PREFIX "table"
26
27#define MAX_DEPTH 16
28#define NODE_SIZE L1_CACHE_BYTES
29#define KEYS_PER_NODE (NODE_SIZE / sizeof(sector_t))
30#define CHILDREN_PER_NODE (KEYS_PER_NODE + 1)
31
32struct dm_table {
33 struct mapped_device *md;
34 enum dm_queue_mode type;
35
36 /* btree table */
37 unsigned int depth;
38 unsigned int counts[MAX_DEPTH]; /* in nodes */
39 sector_t *index[MAX_DEPTH];
40
41 unsigned int num_targets;
42 unsigned int num_allocated;
43 sector_t *highs;
44 struct dm_target *targets;
45
46 struct target_type *immutable_target_type;
47
48 bool integrity_supported:1;
49 bool singleton:1;
50 unsigned integrity_added:1;
51
52 /*
53 * Indicates the rw permissions for the new logical
54 * device. This should be a combination of FMODE_READ
55 * and FMODE_WRITE.
56 */
57 fmode_t mode;
58
59 /* a list of devices used by this table */
60 struct list_head devices;
61
62 /* events get handed up using this callback */
63 void (*event_fn)(void *);
64 void *event_context;
65
66 struct dm_md_mempools *mempools;
67
68 struct list_head target_callbacks;
69};
70
71/*
72 * Similar to ceiling(log_size(n))
73 */
74static unsigned int int_log(unsigned int n, unsigned int base)
75{
76 int result = 0;
77
78 while (n > 1) {
79 n = dm_div_up(n, base);
80 result++;
81 }
82
83 return result;
84}
85
86/*
87 * Calculate the index of the child node of the n'th node k'th key.
88 */
89static inline unsigned int get_child(unsigned int n, unsigned int k)
90{
91 return (n * CHILDREN_PER_NODE) + k;
92}
93
94/*
95 * Return the n'th node of level l from table t.
96 */
97static inline sector_t *get_node(struct dm_table *t,
98 unsigned int l, unsigned int n)
99{
100 return t->index[l] + (n * KEYS_PER_NODE);
101}
102
103/*
104 * Return the highest key that you could lookup from the n'th
105 * node on level l of the btree.
106 */
107static sector_t high(struct dm_table *t, unsigned int l, unsigned int n)
108{
109 for (; l < t->depth - 1; l++)
110 n = get_child(n, CHILDREN_PER_NODE - 1);
111
112 if (n >= t->counts[l])
113 return (sector_t) - 1;
114
115 return get_node(t, l, n)[KEYS_PER_NODE - 1];
116}
117
118/*
119 * Fills in a level of the btree based on the highs of the level
120 * below it.
121 */
122static int setup_btree_index(unsigned int l, struct dm_table *t)
123{
124 unsigned int n, k;
125 sector_t *node;
126
127 for (n = 0U; n < t->counts[l]; n++) {
128 node = get_node(t, l, n);
129
130 for (k = 0U; k < KEYS_PER_NODE; k++)
131 node[k] = high(t, l + 1, get_child(n, k));
132 }
133
134 return 0;
135}
136
137void *dm_vcalloc(unsigned long nmemb, unsigned long elem_size)
138{
139 unsigned long size;
140 void *addr;
141
142 /*
143 * Check that we're not going to overflow.
144 */
145 if (nmemb > (ULONG_MAX / elem_size))
146 return NULL;
147
148 size = nmemb * elem_size;
149 addr = vzalloc(size);
150
151 return addr;
152}
153EXPORT_SYMBOL(dm_vcalloc);
154
155/*
156 * highs, and targets are managed as dynamic arrays during a
157 * table load.
158 */
159static int alloc_targets(struct dm_table *t, unsigned int num)
160{
161 sector_t *n_highs;
162 struct dm_target *n_targets;
163
164 /*
165 * Allocate both the target array and offset array at once.
166 * Append an empty entry to catch sectors beyond the end of
167 * the device.
168 */
169 n_highs = (sector_t *) dm_vcalloc(num + 1, sizeof(struct dm_target) +
170 sizeof(sector_t));
171 if (!n_highs)
172 return -ENOMEM;
173
174 n_targets = (struct dm_target *) (n_highs + num);
175
176 memset(n_highs, -1, sizeof(*n_highs) * num);
177 vfree(t->highs);
178
179 t->num_allocated = num;
180 t->highs = n_highs;
181 t->targets = n_targets;
182
183 return 0;
184}
185
186int dm_table_create(struct dm_table **result, fmode_t mode,
187 unsigned num_targets, struct mapped_device *md)
188{
189 struct dm_table *t = kzalloc(sizeof(*t), GFP_KERNEL);
190
191 if (!t)
192 return -ENOMEM;
193
194 INIT_LIST_HEAD(&t->devices);
195 INIT_LIST_HEAD(&t->target_callbacks);
196
197 if (!num_targets)
198 num_targets = KEYS_PER_NODE;
199
200 num_targets = dm_round_up(num_targets, KEYS_PER_NODE);
201
202 if (!num_targets) {
203 kfree(t);
204 return -ENOMEM;
205 }
206
207 if (alloc_targets(t, num_targets)) {
208 kfree(t);
209 return -ENOMEM;
210 }
211
212 t->type = DM_TYPE_NONE;
213 t->mode = mode;
214 t->md = md;
215 *result = t;
216 return 0;
217}
218
219static void free_devices(struct list_head *devices, struct mapped_device *md)
220{
221 struct list_head *tmp, *next;
222
223 list_for_each_safe(tmp, next, devices) {
224 struct dm_dev_internal *dd =
225 list_entry(tmp, struct dm_dev_internal, list);
226 DMWARN("%s: dm_table_destroy: dm_put_device call missing for %s",
227 dm_device_name(md), dd->dm_dev->name);
228 dm_put_table_device(md, dd->dm_dev);
229 kfree(dd);
230 }
231}
232
233void dm_table_destroy(struct dm_table *t)
234{
235 unsigned int i;
236
237 if (!t)
238 return;
239
240 /* free the indexes */
241 if (t->depth >= 2)
242 vfree(t->index[t->depth - 2]);
243
244 /* free the targets */
245 for (i = 0; i < t->num_targets; i++) {
246 struct dm_target *tgt = t->targets + i;
247
248 if (tgt->type->dtr)
249 tgt->type->dtr(tgt);
250
251 dm_put_target_type(tgt->type);
252 }
253
254 vfree(t->highs);
255
256 /* free the device list */
257 free_devices(&t->devices, t->md);
258
259 dm_free_md_mempools(t->mempools);
260
261 kfree(t);
262}
263
264/*
265 * See if we've already got a device in the list.
266 */
267static struct dm_dev_internal *find_device(struct list_head *l, dev_t dev)
268{
269 struct dm_dev_internal *dd;
270
271 list_for_each_entry (dd, l, list)
272 if (dd->dm_dev->bdev->bd_dev == dev)
273 return dd;
274
275 return NULL;
276}
277
278/*
279 * If possible, this checks an area of a destination device is invalid.
280 */
281static int device_area_is_invalid(struct dm_target *ti, struct dm_dev *dev,
282 sector_t start, sector_t len, void *data)
283{
284 struct request_queue *q;
285 struct queue_limits *limits = data;
286 struct block_device *bdev = dev->bdev;
287 sector_t dev_size =
288 i_size_read(bdev->bd_inode) >> SECTOR_SHIFT;
289 unsigned short logical_block_size_sectors =
290 limits->logical_block_size >> SECTOR_SHIFT;
291 char b[BDEVNAME_SIZE];
292
293 /*
294 * Some devices exist without request functions,
295 * such as loop devices not yet bound to backing files.
296 * Forbid the use of such devices.
297 */
298 q = bdev_get_queue(bdev);
299 if (!q || !q->make_request_fn) {
300 DMWARN("%s: %s is not yet initialised: "
301 "start=%llu, len=%llu, dev_size=%llu",
302 dm_device_name(ti->table->md), bdevname(bdev, b),
303 (unsigned long long)start,
304 (unsigned long long)len,
305 (unsigned long long)dev_size);
306 return 1;
307 }
308
309 if (!dev_size)
310 return 0;
311
312 if ((start >= dev_size) || (start + len > dev_size)) {
313 DMWARN("%s: %s too small for target: "
314 "start=%llu, len=%llu, dev_size=%llu",
315 dm_device_name(ti->table->md), bdevname(bdev, b),
316 (unsigned long long)start,
317 (unsigned long long)len,
318 (unsigned long long)dev_size);
319 return 1;
320 }
321
322 /*
323 * If the target is mapped to zoned block device(s), check
324 * that the zones are not partially mapped.
325 */
326 if (bdev_zoned_model(bdev) != BLK_ZONED_NONE) {
327 unsigned int zone_sectors = bdev_zone_sectors(bdev);
328
329 if (start & (zone_sectors - 1)) {
330 DMWARN("%s: start=%llu not aligned to h/w zone size %u of %s",
331 dm_device_name(ti->table->md),
332 (unsigned long long)start,
333 zone_sectors, bdevname(bdev, b));
334 return 1;
335 }
336
337 /*
338 * Note: The last zone of a zoned block device may be smaller
339 * than other zones. So for a target mapping the end of a
340 * zoned block device with such a zone, len would not be zone
341 * aligned. We do not allow such last smaller zone to be part
342 * of the mapping here to ensure that mappings with multiple
343 * devices do not end up with a smaller zone in the middle of
344 * the sector range.
345 */
346 if (len & (zone_sectors - 1)) {
347 DMWARN("%s: len=%llu not aligned to h/w zone size %u of %s",
348 dm_device_name(ti->table->md),
349 (unsigned long long)len,
350 zone_sectors, bdevname(bdev, b));
351 return 1;
352 }
353 }
354
355 if (logical_block_size_sectors <= 1)
356 return 0;
357
358 if (start & (logical_block_size_sectors - 1)) {
359 DMWARN("%s: start=%llu not aligned to h/w "
360 "logical block size %u of %s",
361 dm_device_name(ti->table->md),
362 (unsigned long long)start,
363 limits->logical_block_size, bdevname(bdev, b));
364 return 1;
365 }
366
367 if (len & (logical_block_size_sectors - 1)) {
368 DMWARN("%s: len=%llu not aligned to h/w "
369 "logical block size %u of %s",
370 dm_device_name(ti->table->md),
371 (unsigned long long)len,
372 limits->logical_block_size, bdevname(bdev, b));
373 return 1;
374 }
375
376 return 0;
377}
378
379/*
380 * This upgrades the mode on an already open dm_dev, being
381 * careful to leave things as they were if we fail to reopen the
382 * device and not to touch the existing bdev field in case
383 * it is accessed concurrently inside dm_table_any_congested().
384 */
385static int upgrade_mode(struct dm_dev_internal *dd, fmode_t new_mode,
386 struct mapped_device *md)
387{
388 int r;
389 struct dm_dev *old_dev, *new_dev;
390
391 old_dev = dd->dm_dev;
392
393 r = dm_get_table_device(md, dd->dm_dev->bdev->bd_dev,
394 dd->dm_dev->mode | new_mode, &new_dev);
395 if (r)
396 return r;
397
398 dd->dm_dev = new_dev;
399 dm_put_table_device(md, old_dev);
400
401 return 0;
402}
403
404/*
405 * Convert the path to a device
406 */
407dev_t dm_get_dev_t(const char *path)
408{
409 dev_t dev;
410 struct block_device *bdev;
411
412 bdev = lookup_bdev(path);
413 if (IS_ERR(bdev))
414 dev = name_to_dev_t(path);
415 else {
416 dev = bdev->bd_dev;
417 bdput(bdev);
418 }
419
420 return dev;
421}
422EXPORT_SYMBOL_GPL(dm_get_dev_t);
423
424/*
425 * Add a device to the list, or just increment the usage count if
426 * it's already present.
427 */
428int dm_get_device(struct dm_target *ti, const char *path, fmode_t mode,
429 struct dm_dev **result)
430{
431 int r;
432 dev_t dev;
433 struct dm_dev_internal *dd;
434 struct dm_table *t = ti->table;
435
436 BUG_ON(!t);
437
438 dev = dm_get_dev_t(path);
439 if (!dev)
440 return -ENODEV;
441
442 dd = find_device(&t->devices, dev);
443 if (!dd) {
444 dd = kmalloc(sizeof(*dd), GFP_KERNEL);
445 if (!dd)
446 return -ENOMEM;
447
448 if ((r = dm_get_table_device(t->md, dev, mode, &dd->dm_dev))) {
449 kfree(dd);
450 return r;
451 }
452
453 refcount_set(&dd->count, 1);
454 list_add(&dd->list, &t->devices);
455 goto out;
456
457 } else if (dd->dm_dev->mode != (mode | dd->dm_dev->mode)) {
458 r = upgrade_mode(dd, mode, t->md);
459 if (r)
460 return r;
461 }
462 refcount_inc(&dd->count);
463out:
464 *result = dd->dm_dev;
465 return 0;
466}
467EXPORT_SYMBOL(dm_get_device);
468
469static int dm_set_device_limits(struct dm_target *ti, struct dm_dev *dev,
470 sector_t start, sector_t len, void *data)
471{
472 struct queue_limits *limits = data;
473 struct block_device *bdev = dev->bdev;
474 struct request_queue *q = bdev_get_queue(bdev);
475 char b[BDEVNAME_SIZE];
476
477 if (unlikely(!q)) {
478 DMWARN("%s: Cannot set limits for nonexistent device %s",
479 dm_device_name(ti->table->md), bdevname(bdev, b));
480 return 0;
481 }
482
483 if (bdev_stack_limits(limits, bdev, start) < 0)
484 DMWARN("%s: adding target device %s caused an alignment inconsistency: "
485 "physical_block_size=%u, logical_block_size=%u, "
486 "alignment_offset=%u, start=%llu",
487 dm_device_name(ti->table->md), bdevname(bdev, b),
488 q->limits.physical_block_size,
489 q->limits.logical_block_size,
490 q->limits.alignment_offset,
491 (unsigned long long) start << SECTOR_SHIFT);
492
493 limits->zoned = blk_queue_zoned_model(q);
494
495 return 0;
496}
497
498/*
499 * Decrement a device's use count and remove it if necessary.
500 */
501void dm_put_device(struct dm_target *ti, struct dm_dev *d)
502{
503 int found = 0;
504 struct list_head *devices = &ti->table->devices;
505 struct dm_dev_internal *dd;
506
507 list_for_each_entry(dd, devices, list) {
508 if (dd->dm_dev == d) {
509 found = 1;
510 break;
511 }
512 }
513 if (!found) {
514 DMWARN("%s: device %s not in table devices list",
515 dm_device_name(ti->table->md), d->name);
516 return;
517 }
518 if (refcount_dec_and_test(&dd->count)) {
519 dm_put_table_device(ti->table->md, d);
520 list_del(&dd->list);
521 kfree(dd);
522 }
523}
524EXPORT_SYMBOL(dm_put_device);
525
526/*
527 * Checks to see if the target joins onto the end of the table.
528 */
529static int adjoin(struct dm_table *table, struct dm_target *ti)
530{
531 struct dm_target *prev;
532
533 if (!table->num_targets)
534 return !ti->begin;
535
536 prev = &table->targets[table->num_targets - 1];
537 return (ti->begin == (prev->begin + prev->len));
538}
539
540/*
541 * Used to dynamically allocate the arg array.
542 *
543 * We do first allocation with GFP_NOIO because dm-mpath and dm-thin must
544 * process messages even if some device is suspended. These messages have a
545 * small fixed number of arguments.
546 *
547 * On the other hand, dm-switch needs to process bulk data using messages and
548 * excessive use of GFP_NOIO could cause trouble.
549 */
550static char **realloc_argv(unsigned *size, char **old_argv)
551{
552 char **argv;
553 unsigned new_size;
554 gfp_t gfp;
555
556 if (*size) {
557 new_size = *size * 2;
558 gfp = GFP_KERNEL;
559 } else {
560 new_size = 8;
561 gfp = GFP_NOIO;
562 }
563 argv = kmalloc_array(new_size, sizeof(*argv), gfp);
564 if (argv) {
565 memcpy(argv, old_argv, *size * sizeof(*argv));
566 *size = new_size;
567 }
568
569 kfree(old_argv);
570 return argv;
571}
572
573/*
574 * Destructively splits up the argument list to pass to ctr.
575 */
576int dm_split_args(int *argc, char ***argvp, char *input)
577{
578 char *start, *end = input, *out, **argv = NULL;
579 unsigned array_size = 0;
580
581 *argc = 0;
582
583 if (!input) {
584 *argvp = NULL;
585 return 0;
586 }
587
588 argv = realloc_argv(&array_size, argv);
589 if (!argv)
590 return -ENOMEM;
591
592 while (1) {
593 /* Skip whitespace */
594 start = skip_spaces(end);
595
596 if (!*start)
597 break; /* success, we hit the end */
598
599 /* 'out' is used to remove any back-quotes */
600 end = out = start;
601 while (*end) {
602 /* Everything apart from '\0' can be quoted */
603 if (*end == '\\' && *(end + 1)) {
604 *out++ = *(end + 1);
605 end += 2;
606 continue;
607 }
608
609 if (isspace(*end))
610 break; /* end of token */
611
612 *out++ = *end++;
613 }
614
615 /* have we already filled the array ? */
616 if ((*argc + 1) > array_size) {
617 argv = realloc_argv(&array_size, argv);
618 if (!argv)
619 return -ENOMEM;
620 }
621
622 /* we know this is whitespace */
623 if (*end)
624 end++;
625
626 /* terminate the string and put it in the array */
627 *out = '\0';
628 argv[*argc] = start;
629 (*argc)++;
630 }
631
632 *argvp = argv;
633 return 0;
634}
635
636/*
637 * Impose necessary and sufficient conditions on a devices's table such
638 * that any incoming bio which respects its logical_block_size can be
639 * processed successfully. If it falls across the boundary between
640 * two or more targets, the size of each piece it gets split into must
641 * be compatible with the logical_block_size of the target processing it.
642 */
643static int validate_hardware_logical_block_alignment(struct dm_table *table,
644 struct queue_limits *limits)
645{
646 /*
647 * This function uses arithmetic modulo the logical_block_size
648 * (in units of 512-byte sectors).
649 */
650 unsigned short device_logical_block_size_sects =
651 limits->logical_block_size >> SECTOR_SHIFT;
652
653 /*
654 * Offset of the start of the next table entry, mod logical_block_size.
655 */
656 unsigned short next_target_start = 0;
657
658 /*
659 * Given an aligned bio that extends beyond the end of a
660 * target, how many sectors must the next target handle?
661 */
662 unsigned short remaining = 0;
663
664 struct dm_target *uninitialized_var(ti);
665 struct queue_limits ti_limits;
666 unsigned i;
667
668 /*
669 * Check each entry in the table in turn.
670 */
671 for (i = 0; i < dm_table_get_num_targets(table); i++) {
672 ti = dm_table_get_target(table, i);
673
674 blk_set_stacking_limits(&ti_limits);
675
676 /* combine all target devices' limits */
677 if (ti->type->iterate_devices)
678 ti->type->iterate_devices(ti, dm_set_device_limits,
679 &ti_limits);
680
681 /*
682 * If the remaining sectors fall entirely within this
683 * table entry are they compatible with its logical_block_size?
684 */
685 if (remaining < ti->len &&
686 remaining & ((ti_limits.logical_block_size >>
687 SECTOR_SHIFT) - 1))
688 break; /* Error */
689
690 next_target_start =
691 (unsigned short) ((next_target_start + ti->len) &
692 (device_logical_block_size_sects - 1));
693 remaining = next_target_start ?
694 device_logical_block_size_sects - next_target_start : 0;
695 }
696
697 if (remaining) {
698 DMWARN("%s: table line %u (start sect %llu len %llu) "
699 "not aligned to h/w logical block size %u",
700 dm_device_name(table->md), i,
701 (unsigned long long) ti->begin,
702 (unsigned long long) ti->len,
703 limits->logical_block_size);
704 return -EINVAL;
705 }
706
707 return 0;
708}
709
710int dm_table_add_target(struct dm_table *t, const char *type,
711 sector_t start, sector_t len, char *params)
712{
713 int r = -EINVAL, argc;
714 char **argv;
715 struct dm_target *tgt;
716
717 if (t->singleton) {
718 DMERR("%s: target type %s must appear alone in table",
719 dm_device_name(t->md), t->targets->type->name);
720 return -EINVAL;
721 }
722
723 BUG_ON(t->num_targets >= t->num_allocated);
724
725 tgt = t->targets + t->num_targets;
726 memset(tgt, 0, sizeof(*tgt));
727
728 if (!len) {
729 DMERR("%s: zero-length target", dm_device_name(t->md));
730 return -EINVAL;
731 }
732
733 tgt->type = dm_get_target_type(type);
734 if (!tgt->type) {
735 DMERR("%s: %s: unknown target type", dm_device_name(t->md), type);
736 return -EINVAL;
737 }
738
739 if (dm_target_needs_singleton(tgt->type)) {
740 if (t->num_targets) {
741 tgt->error = "singleton target type must appear alone in table";
742 goto bad;
743 }
744 t->singleton = true;
745 }
746
747 if (dm_target_always_writeable(tgt->type) && !(t->mode & FMODE_WRITE)) {
748 tgt->error = "target type may not be included in a read-only table";
749 goto bad;
750 }
751
752 if (t->immutable_target_type) {
753 if (t->immutable_target_type != tgt->type) {
754 tgt->error = "immutable target type cannot be mixed with other target types";
755 goto bad;
756 }
757 } else if (dm_target_is_immutable(tgt->type)) {
758 if (t->num_targets) {
759 tgt->error = "immutable target type cannot be mixed with other target types";
760 goto bad;
761 }
762 t->immutable_target_type = tgt->type;
763 }
764
765 if (dm_target_has_integrity(tgt->type))
766 t->integrity_added = 1;
767
768 tgt->table = t;
769 tgt->begin = start;
770 tgt->len = len;
771 tgt->error = "Unknown error";
772
773 /*
774 * Does this target adjoin the previous one ?
775 */
776 if (!adjoin(t, tgt)) {
777 tgt->error = "Gap in table";
778 goto bad;
779 }
780
781 r = dm_split_args(&argc, &argv, params);
782 if (r) {
783 tgt->error = "couldn't split parameters (insufficient memory)";
784 goto bad;
785 }
786
787 r = tgt->type->ctr(tgt, argc, argv);
788 kfree(argv);
789 if (r)
790 goto bad;
791
792 t->highs[t->num_targets++] = tgt->begin + tgt->len - 1;
793
794 if (!tgt->num_discard_bios && tgt->discards_supported)
795 DMWARN("%s: %s: ignoring discards_supported because num_discard_bios is zero.",
796 dm_device_name(t->md), type);
797
798 return 0;
799
800 bad:
801 DMERR("%s: %s: %s", dm_device_name(t->md), type, tgt->error);
802 dm_put_target_type(tgt->type);
803 return r;
804}
805
806/*
807 * Target argument parsing helpers.
808 */
809static int validate_next_arg(const struct dm_arg *arg,
810 struct dm_arg_set *arg_set,
811 unsigned *value, char **error, unsigned grouped)
812{
813 const char *arg_str = dm_shift_arg(arg_set);
814 char dummy;
815
816 if (!arg_str ||
817 (sscanf(arg_str, "%u%c", value, &dummy) != 1) ||
818 (*value < arg->min) ||
819 (*value > arg->max) ||
820 (grouped && arg_set->argc < *value)) {
821 *error = arg->error;
822 return -EINVAL;
823 }
824
825 return 0;
826}
827
828int dm_read_arg(const struct dm_arg *arg, struct dm_arg_set *arg_set,
829 unsigned *value, char **error)
830{
831 return validate_next_arg(arg, arg_set, value, error, 0);
832}
833EXPORT_SYMBOL(dm_read_arg);
834
835int dm_read_arg_group(const struct dm_arg *arg, struct dm_arg_set *arg_set,
836 unsigned *value, char **error)
837{
838 return validate_next_arg(arg, arg_set, value, error, 1);
839}
840EXPORT_SYMBOL(dm_read_arg_group);
841
842const char *dm_shift_arg(struct dm_arg_set *as)
843{
844 char *r;
845
846 if (as->argc) {
847 as->argc--;
848 r = *as->argv;
849 as->argv++;
850 return r;
851 }
852
853 return NULL;
854}
855EXPORT_SYMBOL(dm_shift_arg);
856
857void dm_consume_args(struct dm_arg_set *as, unsigned num_args)
858{
859 BUG_ON(as->argc < num_args);
860 as->argc -= num_args;
861 as->argv += num_args;
862}
863EXPORT_SYMBOL(dm_consume_args);
864
865static bool __table_type_bio_based(enum dm_queue_mode table_type)
866{
867 return (table_type == DM_TYPE_BIO_BASED ||
868 table_type == DM_TYPE_DAX_BIO_BASED ||
869 table_type == DM_TYPE_NVME_BIO_BASED);
870}
871
872static bool __table_type_request_based(enum dm_queue_mode table_type)
873{
874 return table_type == DM_TYPE_REQUEST_BASED;
875}
876
877void dm_table_set_type(struct dm_table *t, enum dm_queue_mode type)
878{
879 t->type = type;
880}
881EXPORT_SYMBOL_GPL(dm_table_set_type);
882
883static int device_supports_dax(struct dm_target *ti, struct dm_dev *dev,
884 sector_t start, sector_t len, void *data)
885{
886 return bdev_dax_supported(dev->bdev, PAGE_SIZE);
887}
888
889static bool dm_table_supports_dax(struct dm_table *t)
890{
891 struct dm_target *ti;
892 unsigned i;
893
894 /* Ensure that all targets support DAX. */
895 for (i = 0; i < dm_table_get_num_targets(t); i++) {
896 ti = dm_table_get_target(t, i);
897
898 if (!ti->type->direct_access)
899 return false;
900
901 if (!ti->type->iterate_devices ||
902 !ti->type->iterate_devices(ti, device_supports_dax, NULL))
903 return false;
904 }
905
906 return true;
907}
908
909static bool dm_table_does_not_support_partial_completion(struct dm_table *t);
910
911struct verify_rq_based_data {
912 unsigned sq_count;
913 unsigned mq_count;
914};
915
916static int device_is_rq_based(struct dm_target *ti, struct dm_dev *dev,
917 sector_t start, sector_t len, void *data)
918{
919 struct request_queue *q = bdev_get_queue(dev->bdev);
920 struct verify_rq_based_data *v = data;
921
922 if (queue_is_mq(q))
923 v->mq_count++;
924 else
925 v->sq_count++;
926
927 return queue_is_mq(q);
928}
929
930static int dm_table_determine_type(struct dm_table *t)
931{
932 unsigned i;
933 unsigned bio_based = 0, request_based = 0, hybrid = 0;
934 struct verify_rq_based_data v = {.sq_count = 0, .mq_count = 0};
935 struct dm_target *tgt;
936 struct list_head *devices = dm_table_get_devices(t);
937 enum dm_queue_mode live_md_type = dm_get_md_type(t->md);
938
939 if (t->type != DM_TYPE_NONE) {
940 /* target already set the table's type */
941 if (t->type == DM_TYPE_BIO_BASED) {
942 /* possibly upgrade to a variant of bio-based */
943 goto verify_bio_based;
944 }
945 BUG_ON(t->type == DM_TYPE_DAX_BIO_BASED);
946 BUG_ON(t->type == DM_TYPE_NVME_BIO_BASED);
947 goto verify_rq_based;
948 }
949
950 for (i = 0; i < t->num_targets; i++) {
951 tgt = t->targets + i;
952 if (dm_target_hybrid(tgt))
953 hybrid = 1;
954 else if (dm_target_request_based(tgt))
955 request_based = 1;
956 else
957 bio_based = 1;
958
959 if (bio_based && request_based) {
960 DMERR("Inconsistent table: different target types"
961 " can't be mixed up");
962 return -EINVAL;
963 }
964 }
965
966 if (hybrid && !bio_based && !request_based) {
967 /*
968 * The targets can work either way.
969 * Determine the type from the live device.
970 * Default to bio-based if device is new.
971 */
972 if (__table_type_request_based(live_md_type))
973 request_based = 1;
974 else
975 bio_based = 1;
976 }
977
978 if (bio_based) {
979verify_bio_based:
980 /* We must use this table as bio-based */
981 t->type = DM_TYPE_BIO_BASED;
982 if (dm_table_supports_dax(t) ||
983 (list_empty(devices) && live_md_type == DM_TYPE_DAX_BIO_BASED)) {
984 t->type = DM_TYPE_DAX_BIO_BASED;
985 } else {
986 /* Check if upgrading to NVMe bio-based is valid or required */
987 tgt = dm_table_get_immutable_target(t);
988 if (tgt && !tgt->max_io_len && dm_table_does_not_support_partial_completion(t)) {
989 t->type = DM_TYPE_NVME_BIO_BASED;
990 goto verify_rq_based; /* must be stacked directly on NVMe (blk-mq) */
991 } else if (list_empty(devices) && live_md_type == DM_TYPE_NVME_BIO_BASED) {
992 t->type = DM_TYPE_NVME_BIO_BASED;
993 }
994 }
995 return 0;
996 }
997
998 BUG_ON(!request_based); /* No targets in this table */
999
1000 t->type = DM_TYPE_REQUEST_BASED;
1001
1002verify_rq_based:
1003 /*
1004 * Request-based dm supports only tables that have a single target now.
1005 * To support multiple targets, request splitting support is needed,
1006 * and that needs lots of changes in the block-layer.
1007 * (e.g. request completion process for partial completion.)
1008 */
1009 if (t->num_targets > 1) {
1010 DMERR("%s DM doesn't support multiple targets",
1011 t->type == DM_TYPE_NVME_BIO_BASED ? "nvme bio-based" : "request-based");
1012 return -EINVAL;
1013 }
1014
1015 if (list_empty(devices)) {
1016 int srcu_idx;
1017 struct dm_table *live_table = dm_get_live_table(t->md, &srcu_idx);
1018
1019 /* inherit live table's type */
1020 if (live_table)
1021 t->type = live_table->type;
1022 dm_put_live_table(t->md, srcu_idx);
1023 return 0;
1024 }
1025
1026 tgt = dm_table_get_immutable_target(t);
1027 if (!tgt) {
1028 DMERR("table load rejected: immutable target is required");
1029 return -EINVAL;
1030 } else if (tgt->max_io_len) {
1031 DMERR("table load rejected: immutable target that splits IO is not supported");
1032 return -EINVAL;
1033 }
1034
1035 /* Non-request-stackable devices can't be used for request-based dm */
1036 if (!tgt->type->iterate_devices ||
1037 !tgt->type->iterate_devices(tgt, device_is_rq_based, &v)) {
1038 DMERR("table load rejected: including non-request-stackable devices");
1039 return -EINVAL;
1040 }
1041 if (v.sq_count > 0) {
1042 DMERR("table load rejected: not all devices are blk-mq request-stackable");
1043 return -EINVAL;
1044 }
1045
1046 return 0;
1047}
1048
1049enum dm_queue_mode dm_table_get_type(struct dm_table *t)
1050{
1051 return t->type;
1052}
1053
1054struct target_type *dm_table_get_immutable_target_type(struct dm_table *t)
1055{
1056 return t->immutable_target_type;
1057}
1058
1059struct dm_target *dm_table_get_immutable_target(struct dm_table *t)
1060{
1061 /* Immutable target is implicitly a singleton */
1062 if (t->num_targets > 1 ||
1063 !dm_target_is_immutable(t->targets[0].type))
1064 return NULL;
1065
1066 return t->targets;
1067}
1068
1069struct dm_target *dm_table_get_wildcard_target(struct dm_table *t)
1070{
1071 struct dm_target *ti;
1072 unsigned i;
1073
1074 for (i = 0; i < dm_table_get_num_targets(t); i++) {
1075 ti = dm_table_get_target(t, i);
1076 if (dm_target_is_wildcard(ti->type))
1077 return ti;
1078 }
1079
1080 return NULL;
1081}
1082
1083bool dm_table_bio_based(struct dm_table *t)
1084{
1085 return __table_type_bio_based(dm_table_get_type(t));
1086}
1087
1088bool dm_table_request_based(struct dm_table *t)
1089{
1090 return __table_type_request_based(dm_table_get_type(t));
1091}
1092
1093static int dm_table_alloc_md_mempools(struct dm_table *t, struct mapped_device *md)
1094{
1095 enum dm_queue_mode type = dm_table_get_type(t);
1096 unsigned per_io_data_size = 0;
1097 unsigned min_pool_size = 0;
1098 struct dm_target *ti;
1099 unsigned i;
1100
1101 if (unlikely(type == DM_TYPE_NONE)) {
1102 DMWARN("no table type is set, can't allocate mempools");
1103 return -EINVAL;
1104 }
1105
1106 if (__table_type_bio_based(type))
1107 for (i = 0; i < t->num_targets; i++) {
1108 ti = t->targets + i;
1109 per_io_data_size = max(per_io_data_size, ti->per_io_data_size);
1110 min_pool_size = max(min_pool_size, ti->num_flush_bios);
1111 }
1112
1113 t->mempools = dm_alloc_md_mempools(md, type, t->integrity_supported,
1114 per_io_data_size, min_pool_size);
1115 if (!t->mempools)
1116 return -ENOMEM;
1117
1118 return 0;
1119}
1120
1121void dm_table_free_md_mempools(struct dm_table *t)
1122{
1123 dm_free_md_mempools(t->mempools);
1124 t->mempools = NULL;
1125}
1126
1127struct dm_md_mempools *dm_table_get_md_mempools(struct dm_table *t)
1128{
1129 return t->mempools;
1130}
1131
1132static int setup_indexes(struct dm_table *t)
1133{
1134 int i;
1135 unsigned int total = 0;
1136 sector_t *indexes;
1137
1138 /* allocate the space for *all* the indexes */
1139 for (i = t->depth - 2; i >= 0; i--) {
1140 t->counts[i] = dm_div_up(t->counts[i + 1], CHILDREN_PER_NODE);
1141 total += t->counts[i];
1142 }
1143
1144 indexes = (sector_t *) dm_vcalloc(total, (unsigned long) NODE_SIZE);
1145 if (!indexes)
1146 return -ENOMEM;
1147
1148 /* set up internal nodes, bottom-up */
1149 for (i = t->depth - 2; i >= 0; i--) {
1150 t->index[i] = indexes;
1151 indexes += (KEYS_PER_NODE * t->counts[i]);
1152 setup_btree_index(i, t);
1153 }
1154
1155 return 0;
1156}
1157
1158/*
1159 * Builds the btree to index the map.
1160 */
1161static int dm_table_build_index(struct dm_table *t)
1162{
1163 int r = 0;
1164 unsigned int leaf_nodes;
1165
1166 /* how many indexes will the btree have ? */
1167 leaf_nodes = dm_div_up(t->num_targets, KEYS_PER_NODE);
1168 t->depth = 1 + int_log(leaf_nodes, CHILDREN_PER_NODE);
1169
1170 /* leaf layer has already been set up */
1171 t->counts[t->depth - 1] = leaf_nodes;
1172 t->index[t->depth - 1] = t->highs;
1173
1174 if (t->depth >= 2)
1175 r = setup_indexes(t);
1176
1177 return r;
1178}
1179
1180static bool integrity_profile_exists(struct gendisk *disk)
1181{
1182 return !!blk_get_integrity(disk);
1183}
1184
1185/*
1186 * Get a disk whose integrity profile reflects the table's profile.
1187 * Returns NULL if integrity support was inconsistent or unavailable.
1188 */
1189static struct gendisk * dm_table_get_integrity_disk(struct dm_table *t)
1190{
1191 struct list_head *devices = dm_table_get_devices(t);
1192 struct dm_dev_internal *dd = NULL;
1193 struct gendisk *prev_disk = NULL, *template_disk = NULL;
1194 unsigned i;
1195
1196 for (i = 0; i < dm_table_get_num_targets(t); i++) {
1197 struct dm_target *ti = dm_table_get_target(t, i);
1198 if (!dm_target_passes_integrity(ti->type))
1199 goto no_integrity;
1200 }
1201
1202 list_for_each_entry(dd, devices, list) {
1203 template_disk = dd->dm_dev->bdev->bd_disk;
1204 if (!integrity_profile_exists(template_disk))
1205 goto no_integrity;
1206 else if (prev_disk &&
1207 blk_integrity_compare(prev_disk, template_disk) < 0)
1208 goto no_integrity;
1209 prev_disk = template_disk;
1210 }
1211
1212 return template_disk;
1213
1214no_integrity:
1215 if (prev_disk)
1216 DMWARN("%s: integrity not set: %s and %s profile mismatch",
1217 dm_device_name(t->md),
1218 prev_disk->disk_name,
1219 template_disk->disk_name);
1220 return NULL;
1221}
1222
1223/*
1224 * Register the mapped device for blk_integrity support if the
1225 * underlying devices have an integrity profile. But all devices may
1226 * not have matching profiles (checking all devices isn't reliable
1227 * during table load because this table may use other DM device(s) which
1228 * must be resumed before they will have an initialized integity
1229 * profile). Consequently, stacked DM devices force a 2 stage integrity
1230 * profile validation: First pass during table load, final pass during
1231 * resume.
1232 */
1233static int dm_table_register_integrity(struct dm_table *t)
1234{
1235 struct mapped_device *md = t->md;
1236 struct gendisk *template_disk = NULL;
1237
1238 /* If target handles integrity itself do not register it here. */
1239 if (t->integrity_added)
1240 return 0;
1241
1242 template_disk = dm_table_get_integrity_disk(t);
1243 if (!template_disk)
1244 return 0;
1245
1246 if (!integrity_profile_exists(dm_disk(md))) {
1247 t->integrity_supported = true;
1248 /*
1249 * Register integrity profile during table load; we can do
1250 * this because the final profile must match during resume.
1251 */
1252 blk_integrity_register(dm_disk(md),
1253 blk_get_integrity(template_disk));
1254 return 0;
1255 }
1256
1257 /*
1258 * If DM device already has an initialized integrity
1259 * profile the new profile should not conflict.
1260 */
1261 if (blk_integrity_compare(dm_disk(md), template_disk) < 0) {
1262 DMWARN("%s: conflict with existing integrity profile: "
1263 "%s profile mismatch",
1264 dm_device_name(t->md),
1265 template_disk->disk_name);
1266 return 1;
1267 }
1268
1269 /* Preserve existing integrity profile */
1270 t->integrity_supported = true;
1271 return 0;
1272}
1273
1274/*
1275 * Prepares the table for use by building the indices,
1276 * setting the type, and allocating mempools.
1277 */
1278int dm_table_complete(struct dm_table *t)
1279{
1280 int r;
1281
1282 r = dm_table_determine_type(t);
1283 if (r) {
1284 DMERR("unable to determine table type");
1285 return r;
1286 }
1287
1288 r = dm_table_build_index(t);
1289 if (r) {
1290 DMERR("unable to build btrees");
1291 return r;
1292 }
1293
1294 r = dm_table_register_integrity(t);
1295 if (r) {
1296 DMERR("could not register integrity profile.");
1297 return r;
1298 }
1299
1300 r = dm_table_alloc_md_mempools(t, t->md);
1301 if (r)
1302 DMERR("unable to allocate mempools");
1303
1304 return r;
1305}
1306
1307static DEFINE_MUTEX(_event_lock);
1308void dm_table_event_callback(struct dm_table *t,
1309 void (*fn)(void *), void *context)
1310{
1311 mutex_lock(&_event_lock);
1312 t->event_fn = fn;
1313 t->event_context = context;
1314 mutex_unlock(&_event_lock);
1315}
1316
1317void dm_table_event(struct dm_table *t)
1318{
1319 /*
1320 * You can no longer call dm_table_event() from interrupt
1321 * context, use a bottom half instead.
1322 */
1323 BUG_ON(in_interrupt());
1324
1325 mutex_lock(&_event_lock);
1326 if (t->event_fn)
1327 t->event_fn(t->event_context);
1328 mutex_unlock(&_event_lock);
1329}
1330EXPORT_SYMBOL(dm_table_event);
1331
1332sector_t dm_table_get_size(struct dm_table *t)
1333{
1334 return t->num_targets ? (t->highs[t->num_targets - 1] + 1) : 0;
1335}
1336EXPORT_SYMBOL(dm_table_get_size);
1337
1338struct dm_target *dm_table_get_target(struct dm_table *t, unsigned int index)
1339{
1340 if (index >= t->num_targets)
1341 return NULL;
1342
1343 return t->targets + index;
1344}
1345
1346/*
1347 * Search the btree for the correct target.
1348 *
1349 * Caller should check returned pointer with dm_target_is_valid()
1350 * to trap I/O beyond end of device.
1351 */
1352struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector)
1353{
1354 unsigned int l, n = 0, k = 0;
1355 sector_t *node;
1356
1357 for (l = 0; l < t->depth; l++) {
1358 n = get_child(n, k);
1359 node = get_node(t, l, n);
1360
1361 for (k = 0; k < KEYS_PER_NODE; k++)
1362 if (node[k] >= sector)
1363 break;
1364 }
1365
1366 return &t->targets[(KEYS_PER_NODE * n) + k];
1367}
1368
1369static int count_device(struct dm_target *ti, struct dm_dev *dev,
1370 sector_t start, sector_t len, void *data)
1371{
1372 unsigned *num_devices = data;
1373
1374 (*num_devices)++;
1375
1376 return 0;
1377}
1378
1379/*
1380 * Check whether a table has no data devices attached using each
1381 * target's iterate_devices method.
1382 * Returns false if the result is unknown because a target doesn't
1383 * support iterate_devices.
1384 */
1385bool dm_table_has_no_data_devices(struct dm_table *table)
1386{
1387 struct dm_target *ti;
1388 unsigned i, num_devices;
1389
1390 for (i = 0; i < dm_table_get_num_targets(table); i++) {
1391 ti = dm_table_get_target(table, i);
1392
1393 if (!ti->type->iterate_devices)
1394 return false;
1395
1396 num_devices = 0;
1397 ti->type->iterate_devices(ti, count_device, &num_devices);
1398 if (num_devices)
1399 return false;
1400 }
1401
1402 return true;
1403}
1404
1405static int device_is_zoned_model(struct dm_target *ti, struct dm_dev *dev,
1406 sector_t start, sector_t len, void *data)
1407{
1408 struct request_queue *q = bdev_get_queue(dev->bdev);
1409 enum blk_zoned_model *zoned_model = data;
1410
1411 return q && blk_queue_zoned_model(q) == *zoned_model;
1412}
1413
1414static bool dm_table_supports_zoned_model(struct dm_table *t,
1415 enum blk_zoned_model zoned_model)
1416{
1417 struct dm_target *ti;
1418 unsigned i;
1419
1420 for (i = 0; i < dm_table_get_num_targets(t); i++) {
1421 ti = dm_table_get_target(t, i);
1422
1423 if (zoned_model == BLK_ZONED_HM &&
1424 !dm_target_supports_zoned_hm(ti->type))
1425 return false;
1426
1427 if (!ti->type->iterate_devices ||
1428 !ti->type->iterate_devices(ti, device_is_zoned_model, &zoned_model))
1429 return false;
1430 }
1431
1432 return true;
1433}
1434
1435static int device_matches_zone_sectors(struct dm_target *ti, struct dm_dev *dev,
1436 sector_t start, sector_t len, void *data)
1437{
1438 struct request_queue *q = bdev_get_queue(dev->bdev);
1439 unsigned int *zone_sectors = data;
1440
1441 return q && blk_queue_zone_sectors(q) == *zone_sectors;
1442}
1443
1444static bool dm_table_matches_zone_sectors(struct dm_table *t,
1445 unsigned int zone_sectors)
1446{
1447 struct dm_target *ti;
1448 unsigned i;
1449
1450 for (i = 0; i < dm_table_get_num_targets(t); i++) {
1451 ti = dm_table_get_target(t, i);
1452
1453 if (!ti->type->iterate_devices ||
1454 !ti->type->iterate_devices(ti, device_matches_zone_sectors, &zone_sectors))
1455 return false;
1456 }
1457
1458 return true;
1459}
1460
1461static int validate_hardware_zoned_model(struct dm_table *table,
1462 enum blk_zoned_model zoned_model,
1463 unsigned int zone_sectors)
1464{
1465 if (zoned_model == BLK_ZONED_NONE)
1466 return 0;
1467
1468 if (!dm_table_supports_zoned_model(table, zoned_model)) {
1469 DMERR("%s: zoned model is not consistent across all devices",
1470 dm_device_name(table->md));
1471 return -EINVAL;
1472 }
1473
1474 /* Check zone size validity and compatibility */
1475 if (!zone_sectors || !is_power_of_2(zone_sectors))
1476 return -EINVAL;
1477
1478 if (!dm_table_matches_zone_sectors(table, zone_sectors)) {
1479 DMERR("%s: zone sectors is not consistent across all devices",
1480 dm_device_name(table->md));
1481 return -EINVAL;
1482 }
1483
1484 return 0;
1485}
1486
1487/*
1488 * Establish the new table's queue_limits and validate them.
1489 */
1490int dm_calculate_queue_limits(struct dm_table *table,
1491 struct queue_limits *limits)
1492{
1493 struct dm_target *ti;
1494 struct queue_limits ti_limits;
1495 unsigned i;
1496 enum blk_zoned_model zoned_model = BLK_ZONED_NONE;
1497 unsigned int zone_sectors = 0;
1498
1499 blk_set_stacking_limits(limits);
1500
1501 for (i = 0; i < dm_table_get_num_targets(table); i++) {
1502 blk_set_stacking_limits(&ti_limits);
1503
1504 ti = dm_table_get_target(table, i);
1505
1506 if (!ti->type->iterate_devices)
1507 goto combine_limits;
1508
1509 /*
1510 * Combine queue limits of all the devices this target uses.
1511 */
1512 ti->type->iterate_devices(ti, dm_set_device_limits,
1513 &ti_limits);
1514
1515 if (zoned_model == BLK_ZONED_NONE && ti_limits.zoned != BLK_ZONED_NONE) {
1516 /*
1517 * After stacking all limits, validate all devices
1518 * in table support this zoned model and zone sectors.
1519 */
1520 zoned_model = ti_limits.zoned;
1521 zone_sectors = ti_limits.chunk_sectors;
1522 }
1523
1524 /* Set I/O hints portion of queue limits */
1525 if (ti->type->io_hints)
1526 ti->type->io_hints(ti, &ti_limits);
1527
1528 /*
1529 * Check each device area is consistent with the target's
1530 * overall queue limits.
1531 */
1532 if (ti->type->iterate_devices(ti, device_area_is_invalid,
1533 &ti_limits))
1534 return -EINVAL;
1535
1536combine_limits:
1537 /*
1538 * Merge this target's queue limits into the overall limits
1539 * for the table.
1540 */
1541 if (blk_stack_limits(limits, &ti_limits, 0) < 0)
1542 DMWARN("%s: adding target device "
1543 "(start sect %llu len %llu) "
1544 "caused an alignment inconsistency",
1545 dm_device_name(table->md),
1546 (unsigned long long) ti->begin,
1547 (unsigned long long) ti->len);
1548
1549 /*
1550 * FIXME: this should likely be moved to blk_stack_limits(), would
1551 * also eliminate limits->zoned stacking hack in dm_set_device_limits()
1552 */
1553 if (limits->zoned == BLK_ZONED_NONE && ti_limits.zoned != BLK_ZONED_NONE) {
1554 /*
1555 * By default, the stacked limits zoned model is set to
1556 * BLK_ZONED_NONE in blk_set_stacking_limits(). Update
1557 * this model using the first target model reported
1558 * that is not BLK_ZONED_NONE. This will be either the
1559 * first target device zoned model or the model reported
1560 * by the target .io_hints.
1561 */
1562 limits->zoned = ti_limits.zoned;
1563 }
1564 }
1565
1566 /*
1567 * Verify that the zoned model and zone sectors, as determined before
1568 * any .io_hints override, are the same across all devices in the table.
1569 * - this is especially relevant if .io_hints is emulating a disk-managed
1570 * zoned model (aka BLK_ZONED_NONE) on host-managed zoned block devices.
1571 * BUT...
1572 */
1573 if (limits->zoned != BLK_ZONED_NONE) {
1574 /*
1575 * ...IF the above limits stacking determined a zoned model
1576 * validate that all of the table's devices conform to it.
1577 */
1578 zoned_model = limits->zoned;
1579 zone_sectors = limits->chunk_sectors;
1580 }
1581 if (validate_hardware_zoned_model(table, zoned_model, zone_sectors))
1582 return -EINVAL;
1583
1584 return validate_hardware_logical_block_alignment(table, limits);
1585}
1586
1587/*
1588 * Verify that all devices have an integrity profile that matches the
1589 * DM device's registered integrity profile. If the profiles don't
1590 * match then unregister the DM device's integrity profile.
1591 */
1592static void dm_table_verify_integrity(struct dm_table *t)
1593{
1594 struct gendisk *template_disk = NULL;
1595
1596 if (t->integrity_added)
1597 return;
1598
1599 if (t->integrity_supported) {
1600 /*
1601 * Verify that the original integrity profile
1602 * matches all the devices in this table.
1603 */
1604 template_disk = dm_table_get_integrity_disk(t);
1605 if (template_disk &&
1606 blk_integrity_compare(dm_disk(t->md), template_disk) >= 0)
1607 return;
1608 }
1609
1610 if (integrity_profile_exists(dm_disk(t->md))) {
1611 DMWARN("%s: unable to establish an integrity profile",
1612 dm_device_name(t->md));
1613 blk_integrity_unregister(dm_disk(t->md));
1614 }
1615}
1616
1617static int device_flush_capable(struct dm_target *ti, struct dm_dev *dev,
1618 sector_t start, sector_t len, void *data)
1619{
1620 unsigned long flush = (unsigned long) data;
1621 struct request_queue *q = bdev_get_queue(dev->bdev);
1622
1623 return q && (q->queue_flags & flush);
1624}
1625
1626static bool dm_table_supports_flush(struct dm_table *t, unsigned long flush)
1627{
1628 struct dm_target *ti;
1629 unsigned i;
1630
1631 /*
1632 * Require at least one underlying device to support flushes.
1633 * t->devices includes internal dm devices such as mirror logs
1634 * so we need to use iterate_devices here, which targets
1635 * supporting flushes must provide.
1636 */
1637 for (i = 0; i < dm_table_get_num_targets(t); i++) {
1638 ti = dm_table_get_target(t, i);
1639
1640 if (!ti->num_flush_bios)
1641 continue;
1642
1643 if (ti->flush_supported)
1644 return true;
1645
1646 if (ti->type->iterate_devices &&
1647 ti->type->iterate_devices(ti, device_flush_capable, (void *) flush))
1648 return true;
1649 }
1650
1651 return false;
1652}
1653
1654static int device_dax_write_cache_enabled(struct dm_target *ti,
1655 struct dm_dev *dev, sector_t start,
1656 sector_t len, void *data)
1657{
1658 struct dax_device *dax_dev = dev->dax_dev;
1659
1660 if (!dax_dev)
1661 return false;
1662
1663 if (dax_write_cache_enabled(dax_dev))
1664 return true;
1665 return false;
1666}
1667
1668static int dm_table_supports_dax_write_cache(struct dm_table *t)
1669{
1670 struct dm_target *ti;
1671 unsigned i;
1672
1673 for (i = 0; i < dm_table_get_num_targets(t); i++) {
1674 ti = dm_table_get_target(t, i);
1675
1676 if (ti->type->iterate_devices &&
1677 ti->type->iterate_devices(ti,
1678 device_dax_write_cache_enabled, NULL))
1679 return true;
1680 }
1681
1682 return false;
1683}
1684
1685static int device_is_nonrot(struct dm_target *ti, struct dm_dev *dev,
1686 sector_t start, sector_t len, void *data)
1687{
1688 struct request_queue *q = bdev_get_queue(dev->bdev);
1689
1690 return q && blk_queue_nonrot(q);
1691}
1692
1693static int device_is_not_random(struct dm_target *ti, struct dm_dev *dev,
1694 sector_t start, sector_t len, void *data)
1695{
1696 struct request_queue *q = bdev_get_queue(dev->bdev);
1697
1698 return q && !blk_queue_add_random(q);
1699}
1700
1701static bool dm_table_all_devices_attribute(struct dm_table *t,
1702 iterate_devices_callout_fn func)
1703{
1704 struct dm_target *ti;
1705 unsigned i;
1706
1707 for (i = 0; i < dm_table_get_num_targets(t); i++) {
1708 ti = dm_table_get_target(t, i);
1709
1710 if (!ti->type->iterate_devices ||
1711 !ti->type->iterate_devices(ti, func, NULL))
1712 return false;
1713 }
1714
1715 return true;
1716}
1717
1718static int device_no_partial_completion(struct dm_target *ti, struct dm_dev *dev,
1719 sector_t start, sector_t len, void *data)
1720{
1721 char b[BDEVNAME_SIZE];
1722
1723 /* For now, NVMe devices are the only devices of this class */
1724 return (strncmp(bdevname(dev->bdev, b), "nvme", 4) == 0);
1725}
1726
1727static bool dm_table_does_not_support_partial_completion(struct dm_table *t)
1728{
1729 return dm_table_all_devices_attribute(t, device_no_partial_completion);
1730}
1731
1732static int device_not_write_same_capable(struct dm_target *ti, struct dm_dev *dev,
1733 sector_t start, sector_t len, void *data)
1734{
1735 struct request_queue *q = bdev_get_queue(dev->bdev);
1736
1737 return q && !q->limits.max_write_same_sectors;
1738}
1739
1740static bool dm_table_supports_write_same(struct dm_table *t)
1741{
1742 struct dm_target *ti;
1743 unsigned i;
1744
1745 for (i = 0; i < dm_table_get_num_targets(t); i++) {
1746 ti = dm_table_get_target(t, i);
1747
1748 if (!ti->num_write_same_bios)
1749 return false;
1750
1751 if (!ti->type->iterate_devices ||
1752 ti->type->iterate_devices(ti, device_not_write_same_capable, NULL))
1753 return false;
1754 }
1755
1756 return true;
1757}
1758
1759static int device_not_write_zeroes_capable(struct dm_target *ti, struct dm_dev *dev,
1760 sector_t start, sector_t len, void *data)
1761{
1762 struct request_queue *q = bdev_get_queue(dev->bdev);
1763
1764 return q && !q->limits.max_write_zeroes_sectors;
1765}
1766
1767static bool dm_table_supports_write_zeroes(struct dm_table *t)
1768{
1769 struct dm_target *ti;
1770 unsigned i = 0;
1771
1772 while (i < dm_table_get_num_targets(t)) {
1773 ti = dm_table_get_target(t, i++);
1774
1775 if (!ti->num_write_zeroes_bios)
1776 return false;
1777
1778 if (!ti->type->iterate_devices ||
1779 ti->type->iterate_devices(ti, device_not_write_zeroes_capable, NULL))
1780 return false;
1781 }
1782
1783 return true;
1784}
1785
1786static int device_not_discard_capable(struct dm_target *ti, struct dm_dev *dev,
1787 sector_t start, sector_t len, void *data)
1788{
1789 struct request_queue *q = bdev_get_queue(dev->bdev);
1790
1791 return q && !blk_queue_discard(q);
1792}
1793
1794static bool dm_table_supports_discards(struct dm_table *t)
1795{
1796 struct dm_target *ti;
1797 unsigned i;
1798
1799 for (i = 0; i < dm_table_get_num_targets(t); i++) {
1800 ti = dm_table_get_target(t, i);
1801
1802 if (!ti->num_discard_bios)
1803 return false;
1804
1805 /*
1806 * Either the target provides discard support (as implied by setting
1807 * 'discards_supported') or it relies on _all_ data devices having
1808 * discard support.
1809 */
1810 if (!ti->discards_supported &&
1811 (!ti->type->iterate_devices ||
1812 ti->type->iterate_devices(ti, device_not_discard_capable, NULL)))
1813 return false;
1814 }
1815
1816 return true;
1817}
1818
1819static int device_not_secure_erase_capable(struct dm_target *ti,
1820 struct dm_dev *dev, sector_t start,
1821 sector_t len, void *data)
1822{
1823 struct request_queue *q = bdev_get_queue(dev->bdev);
1824
1825 return q && !blk_queue_secure_erase(q);
1826}
1827
1828static bool dm_table_supports_secure_erase(struct dm_table *t)
1829{
1830 struct dm_target *ti;
1831 unsigned int i;
1832
1833 for (i = 0; i < dm_table_get_num_targets(t); i++) {
1834 ti = dm_table_get_target(t, i);
1835
1836 if (!ti->num_secure_erase_bios)
1837 return false;
1838
1839 if (!ti->type->iterate_devices ||
1840 ti->type->iterate_devices(ti, device_not_secure_erase_capable, NULL))
1841 return false;
1842 }
1843
1844 return true;
1845}
1846
1847void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
1848 struct queue_limits *limits)
1849{
1850 bool wc = false, fua = false;
1851
1852 /*
1853 * Copy table's limits to the DM device's request_queue
1854 */
1855 q->limits = *limits;
1856
1857 if (!dm_table_supports_discards(t)) {
1858 blk_queue_flag_clear(QUEUE_FLAG_DISCARD, q);
1859 /* Must also clear discard limits... */
1860 q->limits.max_discard_sectors = 0;
1861 q->limits.max_hw_discard_sectors = 0;
1862 q->limits.discard_granularity = 0;
1863 q->limits.discard_alignment = 0;
1864 q->limits.discard_misaligned = 0;
1865 } else
1866 blk_queue_flag_set(QUEUE_FLAG_DISCARD, q);
1867
1868 if (dm_table_supports_secure_erase(t))
1869 blk_queue_flag_set(QUEUE_FLAG_SECERASE, q);
1870
1871 if (dm_table_supports_flush(t, (1UL << QUEUE_FLAG_WC))) {
1872 wc = true;
1873 if (dm_table_supports_flush(t, (1UL << QUEUE_FLAG_FUA)))
1874 fua = true;
1875 }
1876 blk_queue_write_cache(q, wc, fua);
1877
1878 if (dm_table_supports_dax(t))
1879 blk_queue_flag_set(QUEUE_FLAG_DAX, q);
1880 else
1881 blk_queue_flag_clear(QUEUE_FLAG_DAX, q);
1882
1883 if (dm_table_supports_dax_write_cache(t))
1884 dax_write_cache(t->md->dax_dev, true);
1885
1886 /* Ensure that all underlying devices are non-rotational. */
1887 if (dm_table_all_devices_attribute(t, device_is_nonrot))
1888 blk_queue_flag_set(QUEUE_FLAG_NONROT, q);
1889 else
1890 blk_queue_flag_clear(QUEUE_FLAG_NONROT, q);
1891
1892 if (!dm_table_supports_write_same(t))
1893 q->limits.max_write_same_sectors = 0;
1894 if (!dm_table_supports_write_zeroes(t))
1895 q->limits.max_write_zeroes_sectors = 0;
1896
1897 dm_table_verify_integrity(t);
1898
1899 /*
1900 * Determine whether or not this queue's I/O timings contribute
1901 * to the entropy pool, Only request-based targets use this.
1902 * Clear QUEUE_FLAG_ADD_RANDOM if any underlying device does not
1903 * have it set.
1904 */
1905 if (blk_queue_add_random(q) && dm_table_all_devices_attribute(t, device_is_not_random))
1906 blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, q);
1907
1908 /*
1909 * For a zoned target, the number of zones should be updated for the
1910 * correct value to be exposed in sysfs queue/nr_zones. For a BIO based
1911 * target, this is all that is needed. For a request based target, the
1912 * queue zone bitmaps must also be updated.
1913 * Use blk_revalidate_disk_zones() to handle this.
1914 */
1915 if (blk_queue_is_zoned(q))
1916 blk_revalidate_disk_zones(t->md->disk);
1917
1918 /* Allow reads to exceed readahead limits */
1919 q->backing_dev_info->io_pages = limits->max_sectors >> (PAGE_SHIFT - 9);
1920}
1921
1922unsigned int dm_table_get_num_targets(struct dm_table *t)
1923{
1924 return t->num_targets;
1925}
1926
1927struct list_head *dm_table_get_devices(struct dm_table *t)
1928{
1929 return &t->devices;
1930}
1931
1932fmode_t dm_table_get_mode(struct dm_table *t)
1933{
1934 return t->mode;
1935}
1936EXPORT_SYMBOL(dm_table_get_mode);
1937
1938enum suspend_mode {
1939 PRESUSPEND,
1940 PRESUSPEND_UNDO,
1941 POSTSUSPEND,
1942};
1943
1944static void suspend_targets(struct dm_table *t, enum suspend_mode mode)
1945{
1946 int i = t->num_targets;
1947 struct dm_target *ti = t->targets;
1948
1949 lockdep_assert_held(&t->md->suspend_lock);
1950
1951 while (i--) {
1952 switch (mode) {
1953 case PRESUSPEND:
1954 if (ti->type->presuspend)
1955 ti->type->presuspend(ti);
1956 break;
1957 case PRESUSPEND_UNDO:
1958 if (ti->type->presuspend_undo)
1959 ti->type->presuspend_undo(ti);
1960 break;
1961 case POSTSUSPEND:
1962 if (ti->type->postsuspend)
1963 ti->type->postsuspend(ti);
1964 break;
1965 }
1966 ti++;
1967 }
1968}
1969
1970void dm_table_presuspend_targets(struct dm_table *t)
1971{
1972 if (!t)
1973 return;
1974
1975 suspend_targets(t, PRESUSPEND);
1976}
1977
1978void dm_table_presuspend_undo_targets(struct dm_table *t)
1979{
1980 if (!t)
1981 return;
1982
1983 suspend_targets(t, PRESUSPEND_UNDO);
1984}
1985
1986void dm_table_postsuspend_targets(struct dm_table *t)
1987{
1988 if (!t)
1989 return;
1990
1991 suspend_targets(t, POSTSUSPEND);
1992}
1993
1994int dm_table_resume_targets(struct dm_table *t)
1995{
1996 int i, r = 0;
1997
1998 lockdep_assert_held(&t->md->suspend_lock);
1999
2000 for (i = 0; i < t->num_targets; i++) {
2001 struct dm_target *ti = t->targets + i;
2002
2003 if (!ti->type->preresume)
2004 continue;
2005
2006 r = ti->type->preresume(ti);
2007 if (r) {
2008 DMERR("%s: %s: preresume failed, error = %d",
2009 dm_device_name(t->md), ti->type->name, r);
2010 return r;
2011 }
2012 }
2013
2014 for (i = 0; i < t->num_targets; i++) {
2015 struct dm_target *ti = t->targets + i;
2016
2017 if (ti->type->resume)
2018 ti->type->resume(ti);
2019 }
2020
2021 return 0;
2022}
2023
2024void dm_table_add_target_callbacks(struct dm_table *t, struct dm_target_callbacks *cb)
2025{
2026 list_add(&cb->list, &t->target_callbacks);
2027}
2028EXPORT_SYMBOL_GPL(dm_table_add_target_callbacks);
2029
2030int dm_table_any_congested(struct dm_table *t, int bdi_bits)
2031{
2032 struct dm_dev_internal *dd;
2033 struct list_head *devices = dm_table_get_devices(t);
2034 struct dm_target_callbacks *cb;
2035 int r = 0;
2036
2037 list_for_each_entry(dd, devices, list) {
2038 struct request_queue *q = bdev_get_queue(dd->dm_dev->bdev);
2039 char b[BDEVNAME_SIZE];
2040
2041 if (likely(q))
2042 r |= bdi_congested(q->backing_dev_info, bdi_bits);
2043 else
2044 DMWARN_LIMIT("%s: any_congested: nonexistent device %s",
2045 dm_device_name(t->md),
2046 bdevname(dd->dm_dev->bdev, b));
2047 }
2048
2049 list_for_each_entry(cb, &t->target_callbacks, list)
2050 if (cb->congested_fn)
2051 r |= cb->congested_fn(cb, bdi_bits);
2052
2053 return r;
2054}
2055
2056struct mapped_device *dm_table_get_md(struct dm_table *t)
2057{
2058 return t->md;
2059}
2060EXPORT_SYMBOL(dm_table_get_md);
2061
2062const char *dm_table_device_name(struct dm_table *t)
2063{
2064 return dm_device_name(t->md);
2065}
2066EXPORT_SYMBOL_GPL(dm_table_device_name);
2067
2068void dm_table_run_md_queue_async(struct dm_table *t)
2069{
2070 struct mapped_device *md;
2071 struct request_queue *queue;
2072
2073 if (!dm_table_request_based(t))
2074 return;
2075
2076 md = dm_table_get_md(t);
2077 queue = dm_get_md_queue(md);
2078 if (queue)
2079 blk_mq_run_hw_queues(queue, true);
2080}
2081EXPORT_SYMBOL(dm_table_run_md_queue_async);
2082
2083