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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#include "dm-rq.h"
10
11#include <linux/module.h>
12#include <linux/vmalloc.h>
13#include <linux/blkdev.h>
14#include <linux/blk-integrity.h>
15#include <linux/namei.h>
16#include <linux/ctype.h>
17#include <linux/string.h>
18#include <linux/slab.h>
19#include <linux/interrupt.h>
20#include <linux/mutex.h>
21#include <linux/delay.h>
22#include <linux/atomic.h>
23#include <linux/blk-mq.h>
24#include <linux/mount.h>
25#include <linux/dax.h>
26
27#define DM_MSG_PREFIX "table"
28
29#define NODE_SIZE L1_CACHE_BYTES
30#define KEYS_PER_NODE (NODE_SIZE / sizeof(sector_t))
31#define CHILDREN_PER_NODE (KEYS_PER_NODE + 1)
32
33/*
34 * Similar to ceiling(log_size(n))
35 */
36static unsigned int int_log(unsigned int n, unsigned int base)
37{
38 int result = 0;
39
40 while (n > 1) {
41 n = dm_div_up(n, base);
42 result++;
43 }
44
45 return result;
46}
47
48/*
49 * Calculate the index of the child node of the n'th node k'th key.
50 */
51static inline unsigned int get_child(unsigned int n, unsigned int k)
52{
53 return (n * CHILDREN_PER_NODE) + k;
54}
55
56/*
57 * Return the n'th node of level l from table t.
58 */
59static inline sector_t *get_node(struct dm_table *t,
60 unsigned int l, unsigned int n)
61{
62 return t->index[l] + (n * KEYS_PER_NODE);
63}
64
65/*
66 * Return the highest key that you could lookup from the n'th
67 * node on level l of the btree.
68 */
69static sector_t high(struct dm_table *t, unsigned int l, unsigned int n)
70{
71 for (; l < t->depth - 1; l++)
72 n = get_child(n, CHILDREN_PER_NODE - 1);
73
74 if (n >= t->counts[l])
75 return (sector_t) - 1;
76
77 return get_node(t, l, n)[KEYS_PER_NODE - 1];
78}
79
80/*
81 * Fills in a level of the btree based on the highs of the level
82 * below it.
83 */
84static int setup_btree_index(unsigned int l, struct dm_table *t)
85{
86 unsigned int n, k;
87 sector_t *node;
88
89 for (n = 0U; n < t->counts[l]; n++) {
90 node = get_node(t, l, n);
91
92 for (k = 0U; k < KEYS_PER_NODE; k++)
93 node[k] = high(t, l + 1, get_child(n, k));
94 }
95
96 return 0;
97}
98
99/*
100 * highs, and targets are managed as dynamic arrays during a
101 * table load.
102 */
103static int alloc_targets(struct dm_table *t, unsigned int num)
104{
105 sector_t *n_highs;
106 struct dm_target *n_targets;
107
108 /*
109 * Allocate both the target array and offset array at once.
110 */
111 n_highs = kvcalloc(num, sizeof(struct dm_target) + sizeof(sector_t),
112 GFP_KERNEL);
113 if (!n_highs)
114 return -ENOMEM;
115
116 n_targets = (struct dm_target *) (n_highs + num);
117
118 memset(n_highs, -1, sizeof(*n_highs) * num);
119 kvfree(t->highs);
120
121 t->num_allocated = num;
122 t->highs = n_highs;
123 t->targets = n_targets;
124
125 return 0;
126}
127
128int dm_table_create(struct dm_table **result, fmode_t mode,
129 unsigned num_targets, struct mapped_device *md)
130{
131 struct dm_table *t = kzalloc(sizeof(*t), GFP_KERNEL);
132
133 if (!t)
134 return -ENOMEM;
135
136 INIT_LIST_HEAD(&t->devices);
137
138 if (!num_targets)
139 num_targets = KEYS_PER_NODE;
140
141 num_targets = dm_round_up(num_targets, KEYS_PER_NODE);
142
143 if (!num_targets) {
144 kfree(t);
145 return -ENOMEM;
146 }
147
148 if (alloc_targets(t, num_targets)) {
149 kfree(t);
150 return -ENOMEM;
151 }
152
153 t->type = DM_TYPE_NONE;
154 t->mode = mode;
155 t->md = md;
156 *result = t;
157 return 0;
158}
159
160static void free_devices(struct list_head *devices, struct mapped_device *md)
161{
162 struct list_head *tmp, *next;
163
164 list_for_each_safe(tmp, next, devices) {
165 struct dm_dev_internal *dd =
166 list_entry(tmp, struct dm_dev_internal, list);
167 DMWARN("%s: dm_table_destroy: dm_put_device call missing for %s",
168 dm_device_name(md), dd->dm_dev->name);
169 dm_put_table_device(md, dd->dm_dev);
170 kfree(dd);
171 }
172}
173
174static void dm_table_destroy_crypto_profile(struct dm_table *t);
175
176void dm_table_destroy(struct dm_table *t)
177{
178 if (!t)
179 return;
180
181 /* free the indexes */
182 if (t->depth >= 2)
183 kvfree(t->index[t->depth - 2]);
184
185 /* free the targets */
186 for (unsigned int i = 0; i < t->num_targets; i++) {
187 struct dm_target *ti = dm_table_get_target(t, i);
188
189 if (ti->type->dtr)
190 ti->type->dtr(ti);
191
192 dm_put_target_type(ti->type);
193 }
194
195 kvfree(t->highs);
196
197 /* free the device list */
198 free_devices(&t->devices, t->md);
199
200 dm_free_md_mempools(t->mempools);
201
202 dm_table_destroy_crypto_profile(t);
203
204 kfree(t);
205}
206
207/*
208 * See if we've already got a device in the list.
209 */
210static struct dm_dev_internal *find_device(struct list_head *l, dev_t dev)
211{
212 struct dm_dev_internal *dd;
213
214 list_for_each_entry (dd, l, list)
215 if (dd->dm_dev->bdev->bd_dev == dev)
216 return dd;
217
218 return NULL;
219}
220
221/*
222 * If possible, this checks an area of a destination device is invalid.
223 */
224static int device_area_is_invalid(struct dm_target *ti, struct dm_dev *dev,
225 sector_t start, sector_t len, void *data)
226{
227 struct queue_limits *limits = data;
228 struct block_device *bdev = dev->bdev;
229 sector_t dev_size = bdev_nr_sectors(bdev);
230 unsigned short logical_block_size_sectors =
231 limits->logical_block_size >> SECTOR_SHIFT;
232
233 if (!dev_size)
234 return 0;
235
236 if ((start >= dev_size) || (start + len > dev_size)) {
237 DMERR("%s: %pg too small for target: "
238 "start=%llu, len=%llu, dev_size=%llu",
239 dm_device_name(ti->table->md), bdev,
240 (unsigned long long)start,
241 (unsigned long long)len,
242 (unsigned long long)dev_size);
243 return 1;
244 }
245
246 /*
247 * If the target is mapped to zoned block device(s), check
248 * that the zones are not partially mapped.
249 */
250 if (bdev_is_zoned(bdev)) {
251 unsigned int zone_sectors = bdev_zone_sectors(bdev);
252
253 if (start & (zone_sectors - 1)) {
254 DMERR("%s: start=%llu not aligned to h/w zone size %u of %pg",
255 dm_device_name(ti->table->md),
256 (unsigned long long)start,
257 zone_sectors, bdev);
258 return 1;
259 }
260
261 /*
262 * Note: The last zone of a zoned block device may be smaller
263 * than other zones. So for a target mapping the end of a
264 * zoned block device with such a zone, len would not be zone
265 * aligned. We do not allow such last smaller zone to be part
266 * of the mapping here to ensure that mappings with multiple
267 * devices do not end up with a smaller zone in the middle of
268 * the sector range.
269 */
270 if (len & (zone_sectors - 1)) {
271 DMERR("%s: len=%llu not aligned to h/w zone size %u of %pg",
272 dm_device_name(ti->table->md),
273 (unsigned long long)len,
274 zone_sectors, bdev);
275 return 1;
276 }
277 }
278
279 if (logical_block_size_sectors <= 1)
280 return 0;
281
282 if (start & (logical_block_size_sectors - 1)) {
283 DMERR("%s: start=%llu not aligned to h/w "
284 "logical block size %u of %pg",
285 dm_device_name(ti->table->md),
286 (unsigned long long)start,
287 limits->logical_block_size, bdev);
288 return 1;
289 }
290
291 if (len & (logical_block_size_sectors - 1)) {
292 DMERR("%s: len=%llu not aligned to h/w "
293 "logical block size %u of %pg",
294 dm_device_name(ti->table->md),
295 (unsigned long long)len,
296 limits->logical_block_size, bdev);
297 return 1;
298 }
299
300 return 0;
301}
302
303/*
304 * This upgrades the mode on an already open dm_dev, being
305 * careful to leave things as they were if we fail to reopen the
306 * device and not to touch the existing bdev field in case
307 * it is accessed concurrently.
308 */
309static int upgrade_mode(struct dm_dev_internal *dd, fmode_t new_mode,
310 struct mapped_device *md)
311{
312 int r;
313 struct dm_dev *old_dev, *new_dev;
314
315 old_dev = dd->dm_dev;
316
317 r = dm_get_table_device(md, dd->dm_dev->bdev->bd_dev,
318 dd->dm_dev->mode | new_mode, &new_dev);
319 if (r)
320 return r;
321
322 dd->dm_dev = new_dev;
323 dm_put_table_device(md, old_dev);
324
325 return 0;
326}
327
328/*
329 * Convert the path to a device
330 */
331dev_t dm_get_dev_t(const char *path)
332{
333 dev_t dev;
334
335 if (lookup_bdev(path, &dev))
336 dev = name_to_dev_t(path);
337 return dev;
338}
339EXPORT_SYMBOL_GPL(dm_get_dev_t);
340
341/*
342 * Add a device to the list, or just increment the usage count if
343 * it's already present.
344 */
345int dm_get_device(struct dm_target *ti, const char *path, fmode_t mode,
346 struct dm_dev **result)
347{
348 int r;
349 dev_t dev;
350 unsigned int major, minor;
351 char dummy;
352 struct dm_dev_internal *dd;
353 struct dm_table *t = ti->table;
354
355 BUG_ON(!t);
356
357 if (sscanf(path, "%u:%u%c", &major, &minor, &dummy) == 2) {
358 /* Extract the major/minor numbers */
359 dev = MKDEV(major, minor);
360 if (MAJOR(dev) != major || MINOR(dev) != minor)
361 return -EOVERFLOW;
362 } else {
363 dev = dm_get_dev_t(path);
364 if (!dev)
365 return -ENODEV;
366 }
367
368 dd = find_device(&t->devices, dev);
369 if (!dd) {
370 dd = kmalloc(sizeof(*dd), GFP_KERNEL);
371 if (!dd)
372 return -ENOMEM;
373
374 if ((r = dm_get_table_device(t->md, dev, mode, &dd->dm_dev))) {
375 kfree(dd);
376 return r;
377 }
378
379 refcount_set(&dd->count, 1);
380 list_add(&dd->list, &t->devices);
381 goto out;
382
383 } else if (dd->dm_dev->mode != (mode | dd->dm_dev->mode)) {
384 r = upgrade_mode(dd, mode, t->md);
385 if (r)
386 return r;
387 }
388 refcount_inc(&dd->count);
389out:
390 *result = dd->dm_dev;
391 return 0;
392}
393EXPORT_SYMBOL(dm_get_device);
394
395static int dm_set_device_limits(struct dm_target *ti, struct dm_dev *dev,
396 sector_t start, sector_t len, void *data)
397{
398 struct queue_limits *limits = data;
399 struct block_device *bdev = dev->bdev;
400 struct request_queue *q = bdev_get_queue(bdev);
401
402 if (unlikely(!q)) {
403 DMWARN("%s: Cannot set limits for nonexistent device %pg",
404 dm_device_name(ti->table->md), bdev);
405 return 0;
406 }
407
408 if (blk_stack_limits(limits, &q->limits,
409 get_start_sect(bdev) + start) < 0)
410 DMWARN("%s: adding target device %pg caused an alignment inconsistency: "
411 "physical_block_size=%u, logical_block_size=%u, "
412 "alignment_offset=%u, start=%llu",
413 dm_device_name(ti->table->md), bdev,
414 q->limits.physical_block_size,
415 q->limits.logical_block_size,
416 q->limits.alignment_offset,
417 (unsigned long long) start << SECTOR_SHIFT);
418 return 0;
419}
420
421/*
422 * Decrement a device's use count and remove it if necessary.
423 */
424void dm_put_device(struct dm_target *ti, struct dm_dev *d)
425{
426 int found = 0;
427 struct list_head *devices = &ti->table->devices;
428 struct dm_dev_internal *dd;
429
430 list_for_each_entry(dd, devices, list) {
431 if (dd->dm_dev == d) {
432 found = 1;
433 break;
434 }
435 }
436 if (!found) {
437 DMERR("%s: device %s not in table devices list",
438 dm_device_name(ti->table->md), d->name);
439 return;
440 }
441 if (refcount_dec_and_test(&dd->count)) {
442 dm_put_table_device(ti->table->md, d);
443 list_del(&dd->list);
444 kfree(dd);
445 }
446}
447EXPORT_SYMBOL(dm_put_device);
448
449/*
450 * Checks to see if the target joins onto the end of the table.
451 */
452static int adjoin(struct dm_table *t, struct dm_target *ti)
453{
454 struct dm_target *prev;
455
456 if (!t->num_targets)
457 return !ti->begin;
458
459 prev = &t->targets[t->num_targets - 1];
460 return (ti->begin == (prev->begin + prev->len));
461}
462
463/*
464 * Used to dynamically allocate the arg array.
465 *
466 * We do first allocation with GFP_NOIO because dm-mpath and dm-thin must
467 * process messages even if some device is suspended. These messages have a
468 * small fixed number of arguments.
469 *
470 * On the other hand, dm-switch needs to process bulk data using messages and
471 * excessive use of GFP_NOIO could cause trouble.
472 */
473static char **realloc_argv(unsigned *size, char **old_argv)
474{
475 char **argv;
476 unsigned new_size;
477 gfp_t gfp;
478
479 if (*size) {
480 new_size = *size * 2;
481 gfp = GFP_KERNEL;
482 } else {
483 new_size = 8;
484 gfp = GFP_NOIO;
485 }
486 argv = kmalloc_array(new_size, sizeof(*argv), gfp);
487 if (argv && old_argv) {
488 memcpy(argv, old_argv, *size * sizeof(*argv));
489 *size = new_size;
490 }
491
492 kfree(old_argv);
493 return argv;
494}
495
496/*
497 * Destructively splits up the argument list to pass to ctr.
498 */
499int dm_split_args(int *argc, char ***argvp, char *input)
500{
501 char *start, *end = input, *out, **argv = NULL;
502 unsigned array_size = 0;
503
504 *argc = 0;
505
506 if (!input) {
507 *argvp = NULL;
508 return 0;
509 }
510
511 argv = realloc_argv(&array_size, argv);
512 if (!argv)
513 return -ENOMEM;
514
515 while (1) {
516 /* Skip whitespace */
517 start = skip_spaces(end);
518
519 if (!*start)
520 break; /* success, we hit the end */
521
522 /* 'out' is used to remove any back-quotes */
523 end = out = start;
524 while (*end) {
525 /* Everything apart from '\0' can be quoted */
526 if (*end == '\\' && *(end + 1)) {
527 *out++ = *(end + 1);
528 end += 2;
529 continue;
530 }
531
532 if (isspace(*end))
533 break; /* end of token */
534
535 *out++ = *end++;
536 }
537
538 /* have we already filled the array ? */
539 if ((*argc + 1) > array_size) {
540 argv = realloc_argv(&array_size, argv);
541 if (!argv)
542 return -ENOMEM;
543 }
544
545 /* we know this is whitespace */
546 if (*end)
547 end++;
548
549 /* terminate the string and put it in the array */
550 *out = '\0';
551 argv[*argc] = start;
552 (*argc)++;
553 }
554
555 *argvp = argv;
556 return 0;
557}
558
559/*
560 * Impose necessary and sufficient conditions on a devices's table such
561 * that any incoming bio which respects its logical_block_size can be
562 * processed successfully. If it falls across the boundary between
563 * two or more targets, the size of each piece it gets split into must
564 * be compatible with the logical_block_size of the target processing it.
565 */
566static int validate_hardware_logical_block_alignment(struct dm_table *t,
567 struct queue_limits *limits)
568{
569 /*
570 * This function uses arithmetic modulo the logical_block_size
571 * (in units of 512-byte sectors).
572 */
573 unsigned short device_logical_block_size_sects =
574 limits->logical_block_size >> SECTOR_SHIFT;
575
576 /*
577 * Offset of the start of the next table entry, mod logical_block_size.
578 */
579 unsigned short next_target_start = 0;
580
581 /*
582 * Given an aligned bio that extends beyond the end of a
583 * target, how many sectors must the next target handle?
584 */
585 unsigned short remaining = 0;
586
587 struct dm_target *ti;
588 struct queue_limits ti_limits;
589 unsigned int i;
590
591 /*
592 * Check each entry in the table in turn.
593 */
594 for (i = 0; i < t->num_targets; i++) {
595 ti = dm_table_get_target(t, i);
596
597 blk_set_stacking_limits(&ti_limits);
598
599 /* combine all target devices' limits */
600 if (ti->type->iterate_devices)
601 ti->type->iterate_devices(ti, dm_set_device_limits,
602 &ti_limits);
603
604 /*
605 * If the remaining sectors fall entirely within this
606 * table entry are they compatible with its logical_block_size?
607 */
608 if (remaining < ti->len &&
609 remaining & ((ti_limits.logical_block_size >>
610 SECTOR_SHIFT) - 1))
611 break; /* Error */
612
613 next_target_start =
614 (unsigned short) ((next_target_start + ti->len) &
615 (device_logical_block_size_sects - 1));
616 remaining = next_target_start ?
617 device_logical_block_size_sects - next_target_start : 0;
618 }
619
620 if (remaining) {
621 DMERR("%s: table line %u (start sect %llu len %llu) "
622 "not aligned to h/w logical block size %u",
623 dm_device_name(t->md), i,
624 (unsigned long long) ti->begin,
625 (unsigned long long) ti->len,
626 limits->logical_block_size);
627 return -EINVAL;
628 }
629
630 return 0;
631}
632
633int dm_table_add_target(struct dm_table *t, const char *type,
634 sector_t start, sector_t len, char *params)
635{
636 int r = -EINVAL, argc;
637 char **argv;
638 struct dm_target *ti;
639
640 if (t->singleton) {
641 DMERR("%s: target type %s must appear alone in table",
642 dm_device_name(t->md), t->targets->type->name);
643 return -EINVAL;
644 }
645
646 BUG_ON(t->num_targets >= t->num_allocated);
647
648 ti = t->targets + t->num_targets;
649 memset(ti, 0, sizeof(*ti));
650
651 if (!len) {
652 DMERR("%s: zero-length target", dm_device_name(t->md));
653 return -EINVAL;
654 }
655
656 ti->type = dm_get_target_type(type);
657 if (!ti->type) {
658 DMERR("%s: %s: unknown target type", dm_device_name(t->md), type);
659 return -EINVAL;
660 }
661
662 if (dm_target_needs_singleton(ti->type)) {
663 if (t->num_targets) {
664 ti->error = "singleton target type must appear alone in table";
665 goto bad;
666 }
667 t->singleton = true;
668 }
669
670 if (dm_target_always_writeable(ti->type) && !(t->mode & FMODE_WRITE)) {
671 ti->error = "target type may not be included in a read-only table";
672 goto bad;
673 }
674
675 if (t->immutable_target_type) {
676 if (t->immutable_target_type != ti->type) {
677 ti->error = "immutable target type cannot be mixed with other target types";
678 goto bad;
679 }
680 } else if (dm_target_is_immutable(ti->type)) {
681 if (t->num_targets) {
682 ti->error = "immutable target type cannot be mixed with other target types";
683 goto bad;
684 }
685 t->immutable_target_type = ti->type;
686 }
687
688 if (dm_target_has_integrity(ti->type))
689 t->integrity_added = 1;
690
691 ti->table = t;
692 ti->begin = start;
693 ti->len = len;
694 ti->error = "Unknown error";
695
696 /*
697 * Does this target adjoin the previous one ?
698 */
699 if (!adjoin(t, ti)) {
700 ti->error = "Gap in table";
701 goto bad;
702 }
703
704 r = dm_split_args(&argc, &argv, params);
705 if (r) {
706 ti->error = "couldn't split parameters";
707 goto bad;
708 }
709
710 r = ti->type->ctr(ti, argc, argv);
711 kfree(argv);
712 if (r)
713 goto bad;
714
715 t->highs[t->num_targets++] = ti->begin + ti->len - 1;
716
717 if (!ti->num_discard_bios && ti->discards_supported)
718 DMWARN("%s: %s: ignoring discards_supported because num_discard_bios is zero.",
719 dm_device_name(t->md), type);
720
721 if (ti->limit_swap_bios && !static_key_enabled(&swap_bios_enabled.key))
722 static_branch_enable(&swap_bios_enabled);
723
724 return 0;
725
726 bad:
727 DMERR("%s: %s: %s (%pe)", dm_device_name(t->md), type, ti->error, ERR_PTR(r));
728 dm_put_target_type(ti->type);
729 return r;
730}
731
732/*
733 * Target argument parsing helpers.
734 */
735static int validate_next_arg(const struct dm_arg *arg,
736 struct dm_arg_set *arg_set,
737 unsigned *value, char **error, unsigned grouped)
738{
739 const char *arg_str = dm_shift_arg(arg_set);
740 char dummy;
741
742 if (!arg_str ||
743 (sscanf(arg_str, "%u%c", value, &dummy) != 1) ||
744 (*value < arg->min) ||
745 (*value > arg->max) ||
746 (grouped && arg_set->argc < *value)) {
747 *error = arg->error;
748 return -EINVAL;
749 }
750
751 return 0;
752}
753
754int dm_read_arg(const struct dm_arg *arg, struct dm_arg_set *arg_set,
755 unsigned *value, char **error)
756{
757 return validate_next_arg(arg, arg_set, value, error, 0);
758}
759EXPORT_SYMBOL(dm_read_arg);
760
761int dm_read_arg_group(const struct dm_arg *arg, struct dm_arg_set *arg_set,
762 unsigned *value, char **error)
763{
764 return validate_next_arg(arg, arg_set, value, error, 1);
765}
766EXPORT_SYMBOL(dm_read_arg_group);
767
768const char *dm_shift_arg(struct dm_arg_set *as)
769{
770 char *r;
771
772 if (as->argc) {
773 as->argc--;
774 r = *as->argv;
775 as->argv++;
776 return r;
777 }
778
779 return NULL;
780}
781EXPORT_SYMBOL(dm_shift_arg);
782
783void dm_consume_args(struct dm_arg_set *as, unsigned num_args)
784{
785 BUG_ON(as->argc < num_args);
786 as->argc -= num_args;
787 as->argv += num_args;
788}
789EXPORT_SYMBOL(dm_consume_args);
790
791static bool __table_type_bio_based(enum dm_queue_mode table_type)
792{
793 return (table_type == DM_TYPE_BIO_BASED ||
794 table_type == DM_TYPE_DAX_BIO_BASED);
795}
796
797static bool __table_type_request_based(enum dm_queue_mode table_type)
798{
799 return table_type == DM_TYPE_REQUEST_BASED;
800}
801
802void dm_table_set_type(struct dm_table *t, enum dm_queue_mode type)
803{
804 t->type = type;
805}
806EXPORT_SYMBOL_GPL(dm_table_set_type);
807
808/* validate the dax capability of the target device span */
809static int device_not_dax_capable(struct dm_target *ti, struct dm_dev *dev,
810 sector_t start, sector_t len, void *data)
811{
812 if (dev->dax_dev)
813 return false;
814
815 DMDEBUG("%pg: error: dax unsupported by block device", dev->bdev);
816 return true;
817}
818
819/* Check devices support synchronous DAX */
820static int device_not_dax_synchronous_capable(struct dm_target *ti, struct dm_dev *dev,
821 sector_t start, sector_t len, void *data)
822{
823 return !dev->dax_dev || !dax_synchronous(dev->dax_dev);
824}
825
826static bool dm_table_supports_dax(struct dm_table *t,
827 iterate_devices_callout_fn iterate_fn)
828{
829 /* Ensure that all targets support DAX. */
830 for (unsigned int i = 0; i < t->num_targets; i++) {
831 struct dm_target *ti = dm_table_get_target(t, i);
832
833 if (!ti->type->direct_access)
834 return false;
835
836 if (!ti->type->iterate_devices ||
837 ti->type->iterate_devices(ti, iterate_fn, NULL))
838 return false;
839 }
840
841 return true;
842}
843
844static int device_is_rq_stackable(struct dm_target *ti, struct dm_dev *dev,
845 sector_t start, sector_t len, void *data)
846{
847 struct block_device *bdev = dev->bdev;
848 struct request_queue *q = bdev_get_queue(bdev);
849
850 /* request-based cannot stack on partitions! */
851 if (bdev_is_partition(bdev))
852 return false;
853
854 return queue_is_mq(q);
855}
856
857static int dm_table_determine_type(struct dm_table *t)
858{
859 unsigned bio_based = 0, request_based = 0, hybrid = 0;
860 struct dm_target *ti;
861 struct list_head *devices = dm_table_get_devices(t);
862 enum dm_queue_mode live_md_type = dm_get_md_type(t->md);
863
864 if (t->type != DM_TYPE_NONE) {
865 /* target already set the table's type */
866 if (t->type == DM_TYPE_BIO_BASED) {
867 /* possibly upgrade to a variant of bio-based */
868 goto verify_bio_based;
869 }
870 BUG_ON(t->type == DM_TYPE_DAX_BIO_BASED);
871 goto verify_rq_based;
872 }
873
874 for (unsigned int i = 0; i < t->num_targets; i++) {
875 ti = dm_table_get_target(t, i);
876 if (dm_target_hybrid(ti))
877 hybrid = 1;
878 else if (dm_target_request_based(ti))
879 request_based = 1;
880 else
881 bio_based = 1;
882
883 if (bio_based && request_based) {
884 DMERR("Inconsistent table: different target types"
885 " can't be mixed up");
886 return -EINVAL;
887 }
888 }
889
890 if (hybrid && !bio_based && !request_based) {
891 /*
892 * The targets can work either way.
893 * Determine the type from the live device.
894 * Default to bio-based if device is new.
895 */
896 if (__table_type_request_based(live_md_type))
897 request_based = 1;
898 else
899 bio_based = 1;
900 }
901
902 if (bio_based) {
903verify_bio_based:
904 /* We must use this table as bio-based */
905 t->type = DM_TYPE_BIO_BASED;
906 if (dm_table_supports_dax(t, device_not_dax_capable) ||
907 (list_empty(devices) && live_md_type == DM_TYPE_DAX_BIO_BASED)) {
908 t->type = DM_TYPE_DAX_BIO_BASED;
909 }
910 return 0;
911 }
912
913 BUG_ON(!request_based); /* No targets in this table */
914
915 t->type = DM_TYPE_REQUEST_BASED;
916
917verify_rq_based:
918 /*
919 * Request-based dm supports only tables that have a single target now.
920 * To support multiple targets, request splitting support is needed,
921 * and that needs lots of changes in the block-layer.
922 * (e.g. request completion process for partial completion.)
923 */
924 if (t->num_targets > 1) {
925 DMERR("request-based DM doesn't support multiple targets");
926 return -EINVAL;
927 }
928
929 if (list_empty(devices)) {
930 int srcu_idx;
931 struct dm_table *live_table = dm_get_live_table(t->md, &srcu_idx);
932
933 /* inherit live table's type */
934 if (live_table)
935 t->type = live_table->type;
936 dm_put_live_table(t->md, srcu_idx);
937 return 0;
938 }
939
940 ti = dm_table_get_immutable_target(t);
941 if (!ti) {
942 DMERR("table load rejected: immutable target is required");
943 return -EINVAL;
944 } else if (ti->max_io_len) {
945 DMERR("table load rejected: immutable target that splits IO is not supported");
946 return -EINVAL;
947 }
948
949 /* Non-request-stackable devices can't be used for request-based dm */
950 if (!ti->type->iterate_devices ||
951 !ti->type->iterate_devices(ti, device_is_rq_stackable, NULL)) {
952 DMERR("table load rejected: including non-request-stackable devices");
953 return -EINVAL;
954 }
955
956 return 0;
957}
958
959enum dm_queue_mode dm_table_get_type(struct dm_table *t)
960{
961 return t->type;
962}
963
964struct target_type *dm_table_get_immutable_target_type(struct dm_table *t)
965{
966 return t->immutable_target_type;
967}
968
969struct dm_target *dm_table_get_immutable_target(struct dm_table *t)
970{
971 /* Immutable target is implicitly a singleton */
972 if (t->num_targets > 1 ||
973 !dm_target_is_immutable(t->targets[0].type))
974 return NULL;
975
976 return t->targets;
977}
978
979struct dm_target *dm_table_get_wildcard_target(struct dm_table *t)
980{
981 for (unsigned int i = 0; i < t->num_targets; i++) {
982 struct dm_target *ti = dm_table_get_target(t, i);
983
984 if (dm_target_is_wildcard(ti->type))
985 return ti;
986 }
987
988 return NULL;
989}
990
991bool dm_table_bio_based(struct dm_table *t)
992{
993 return __table_type_bio_based(dm_table_get_type(t));
994}
995
996bool dm_table_request_based(struct dm_table *t)
997{
998 return __table_type_request_based(dm_table_get_type(t));
999}
1000
1001static bool dm_table_supports_poll(struct dm_table *t);
1002
1003static int dm_table_alloc_md_mempools(struct dm_table *t, struct mapped_device *md)
1004{
1005 enum dm_queue_mode type = dm_table_get_type(t);
1006 unsigned int per_io_data_size = 0, front_pad, io_front_pad;
1007 unsigned int min_pool_size = 0, pool_size;
1008 struct dm_md_mempools *pools;
1009
1010 if (unlikely(type == DM_TYPE_NONE)) {
1011 DMERR("no table type is set, can't allocate mempools");
1012 return -EINVAL;
1013 }
1014
1015 pools = kzalloc_node(sizeof(*pools), GFP_KERNEL, md->numa_node_id);
1016 if (!pools)
1017 return -ENOMEM;
1018
1019 if (type == DM_TYPE_REQUEST_BASED) {
1020 pool_size = dm_get_reserved_rq_based_ios();
1021 front_pad = offsetof(struct dm_rq_clone_bio_info, clone);
1022 goto init_bs;
1023 }
1024
1025 for (unsigned int i = 0; i < t->num_targets; i++) {
1026 struct dm_target *ti = dm_table_get_target(t, i);
1027
1028 per_io_data_size = max(per_io_data_size, ti->per_io_data_size);
1029 min_pool_size = max(min_pool_size, ti->num_flush_bios);
1030 }
1031 pool_size = max(dm_get_reserved_bio_based_ios(), min_pool_size);
1032 front_pad = roundup(per_io_data_size,
1033 __alignof__(struct dm_target_io)) + DM_TARGET_IO_BIO_OFFSET;
1034
1035 io_front_pad = roundup(per_io_data_size,
1036 __alignof__(struct dm_io)) + DM_IO_BIO_OFFSET;
1037 if (bioset_init(&pools->io_bs, pool_size, io_front_pad,
1038 dm_table_supports_poll(t) ? BIOSET_PERCPU_CACHE : 0))
1039 goto out_free_pools;
1040 if (t->integrity_supported &&
1041 bioset_integrity_create(&pools->io_bs, pool_size))
1042 goto out_free_pools;
1043init_bs:
1044 if (bioset_init(&pools->bs, pool_size, front_pad, 0))
1045 goto out_free_pools;
1046 if (t->integrity_supported &&
1047 bioset_integrity_create(&pools->bs, pool_size))
1048 goto out_free_pools;
1049
1050 t->mempools = pools;
1051 return 0;
1052
1053out_free_pools:
1054 dm_free_md_mempools(pools);
1055 return -ENOMEM;
1056}
1057
1058static int setup_indexes(struct dm_table *t)
1059{
1060 int i;
1061 unsigned int total = 0;
1062 sector_t *indexes;
1063
1064 /* allocate the space for *all* the indexes */
1065 for (i = t->depth - 2; i >= 0; i--) {
1066 t->counts[i] = dm_div_up(t->counts[i + 1], CHILDREN_PER_NODE);
1067 total += t->counts[i];
1068 }
1069
1070 indexes = kvcalloc(total, NODE_SIZE, GFP_KERNEL);
1071 if (!indexes)
1072 return -ENOMEM;
1073
1074 /* set up internal nodes, bottom-up */
1075 for (i = t->depth - 2; i >= 0; i--) {
1076 t->index[i] = indexes;
1077 indexes += (KEYS_PER_NODE * t->counts[i]);
1078 setup_btree_index(i, t);
1079 }
1080
1081 return 0;
1082}
1083
1084/*
1085 * Builds the btree to index the map.
1086 */
1087static int dm_table_build_index(struct dm_table *t)
1088{
1089 int r = 0;
1090 unsigned int leaf_nodes;
1091
1092 /* how many indexes will the btree have ? */
1093 leaf_nodes = dm_div_up(t->num_targets, KEYS_PER_NODE);
1094 t->depth = 1 + int_log(leaf_nodes, CHILDREN_PER_NODE);
1095
1096 /* leaf layer has already been set up */
1097 t->counts[t->depth - 1] = leaf_nodes;
1098 t->index[t->depth - 1] = t->highs;
1099
1100 if (t->depth >= 2)
1101 r = setup_indexes(t);
1102
1103 return r;
1104}
1105
1106static bool integrity_profile_exists(struct gendisk *disk)
1107{
1108 return !!blk_get_integrity(disk);
1109}
1110
1111/*
1112 * Get a disk whose integrity profile reflects the table's profile.
1113 * Returns NULL if integrity support was inconsistent or unavailable.
1114 */
1115static struct gendisk *dm_table_get_integrity_disk(struct dm_table *t)
1116{
1117 struct list_head *devices = dm_table_get_devices(t);
1118 struct dm_dev_internal *dd = NULL;
1119 struct gendisk *prev_disk = NULL, *template_disk = NULL;
1120
1121 for (unsigned int i = 0; i < t->num_targets; i++) {
1122 struct dm_target *ti = dm_table_get_target(t, i);
1123
1124 if (!dm_target_passes_integrity(ti->type))
1125 goto no_integrity;
1126 }
1127
1128 list_for_each_entry(dd, devices, list) {
1129 template_disk = dd->dm_dev->bdev->bd_disk;
1130 if (!integrity_profile_exists(template_disk))
1131 goto no_integrity;
1132 else if (prev_disk &&
1133 blk_integrity_compare(prev_disk, template_disk) < 0)
1134 goto no_integrity;
1135 prev_disk = template_disk;
1136 }
1137
1138 return template_disk;
1139
1140no_integrity:
1141 if (prev_disk)
1142 DMWARN("%s: integrity not set: %s and %s profile mismatch",
1143 dm_device_name(t->md),
1144 prev_disk->disk_name,
1145 template_disk->disk_name);
1146 return NULL;
1147}
1148
1149/*
1150 * Register the mapped device for blk_integrity support if the
1151 * underlying devices have an integrity profile. But all devices may
1152 * not have matching profiles (checking all devices isn't reliable
1153 * during table load because this table may use other DM device(s) which
1154 * must be resumed before they will have an initialized integity
1155 * profile). Consequently, stacked DM devices force a 2 stage integrity
1156 * profile validation: First pass during table load, final pass during
1157 * resume.
1158 */
1159static int dm_table_register_integrity(struct dm_table *t)
1160{
1161 struct mapped_device *md = t->md;
1162 struct gendisk *template_disk = NULL;
1163
1164 /* If target handles integrity itself do not register it here. */
1165 if (t->integrity_added)
1166 return 0;
1167
1168 template_disk = dm_table_get_integrity_disk(t);
1169 if (!template_disk)
1170 return 0;
1171
1172 if (!integrity_profile_exists(dm_disk(md))) {
1173 t->integrity_supported = true;
1174 /*
1175 * Register integrity profile during table load; we can do
1176 * this because the final profile must match during resume.
1177 */
1178 blk_integrity_register(dm_disk(md),
1179 blk_get_integrity(template_disk));
1180 return 0;
1181 }
1182
1183 /*
1184 * If DM device already has an initialized integrity
1185 * profile the new profile should not conflict.
1186 */
1187 if (blk_integrity_compare(dm_disk(md), template_disk) < 0) {
1188 DMERR("%s: conflict with existing integrity profile: "
1189 "%s profile mismatch",
1190 dm_device_name(t->md),
1191 template_disk->disk_name);
1192 return 1;
1193 }
1194
1195 /* Preserve existing integrity profile */
1196 t->integrity_supported = true;
1197 return 0;
1198}
1199
1200#ifdef CONFIG_BLK_INLINE_ENCRYPTION
1201
1202struct dm_crypto_profile {
1203 struct blk_crypto_profile profile;
1204 struct mapped_device *md;
1205};
1206
1207struct dm_keyslot_evict_args {
1208 const struct blk_crypto_key *key;
1209 int err;
1210};
1211
1212static int dm_keyslot_evict_callback(struct dm_target *ti, struct dm_dev *dev,
1213 sector_t start, sector_t len, void *data)
1214{
1215 struct dm_keyslot_evict_args *args = data;
1216 int err;
1217
1218 err = blk_crypto_evict_key(dev->bdev, args->key);
1219 if (!args->err)
1220 args->err = err;
1221 /* Always try to evict the key from all devices. */
1222 return 0;
1223}
1224
1225/*
1226 * When an inline encryption key is evicted from a device-mapper device, evict
1227 * it from all the underlying devices.
1228 */
1229static int dm_keyslot_evict(struct blk_crypto_profile *profile,
1230 const struct blk_crypto_key *key, unsigned int slot)
1231{
1232 struct mapped_device *md =
1233 container_of(profile, struct dm_crypto_profile, profile)->md;
1234 struct dm_keyslot_evict_args args = { key };
1235 struct dm_table *t;
1236 int srcu_idx;
1237
1238 t = dm_get_live_table(md, &srcu_idx);
1239 if (!t)
1240 return 0;
1241
1242 for (unsigned int i = 0; i < t->num_targets; i++) {
1243 struct dm_target *ti = dm_table_get_target(t, i);
1244
1245 if (!ti->type->iterate_devices)
1246 continue;
1247 ti->type->iterate_devices(ti, dm_keyslot_evict_callback, &args);
1248 }
1249
1250 dm_put_live_table(md, srcu_idx);
1251 return args.err;
1252}
1253
1254static int
1255device_intersect_crypto_capabilities(struct dm_target *ti, struct dm_dev *dev,
1256 sector_t start, sector_t len, void *data)
1257{
1258 struct blk_crypto_profile *parent = data;
1259 struct blk_crypto_profile *child =
1260 bdev_get_queue(dev->bdev)->crypto_profile;
1261
1262 blk_crypto_intersect_capabilities(parent, child);
1263 return 0;
1264}
1265
1266void dm_destroy_crypto_profile(struct blk_crypto_profile *profile)
1267{
1268 struct dm_crypto_profile *dmcp = container_of(profile,
1269 struct dm_crypto_profile,
1270 profile);
1271
1272 if (!profile)
1273 return;
1274
1275 blk_crypto_profile_destroy(profile);
1276 kfree(dmcp);
1277}
1278
1279static void dm_table_destroy_crypto_profile(struct dm_table *t)
1280{
1281 dm_destroy_crypto_profile(t->crypto_profile);
1282 t->crypto_profile = NULL;
1283}
1284
1285/*
1286 * Constructs and initializes t->crypto_profile with a crypto profile that
1287 * represents the common set of crypto capabilities of the devices described by
1288 * the dm_table. However, if the constructed crypto profile doesn't support all
1289 * crypto capabilities that are supported by the current mapped_device, it
1290 * returns an error instead, since we don't support removing crypto capabilities
1291 * on table changes. Finally, if the constructed crypto profile is "empty" (has
1292 * no crypto capabilities at all), it just sets t->crypto_profile to NULL.
1293 */
1294static int dm_table_construct_crypto_profile(struct dm_table *t)
1295{
1296 struct dm_crypto_profile *dmcp;
1297 struct blk_crypto_profile *profile;
1298 unsigned int i;
1299 bool empty_profile = true;
1300
1301 dmcp = kmalloc(sizeof(*dmcp), GFP_KERNEL);
1302 if (!dmcp)
1303 return -ENOMEM;
1304 dmcp->md = t->md;
1305
1306 profile = &dmcp->profile;
1307 blk_crypto_profile_init(profile, 0);
1308 profile->ll_ops.keyslot_evict = dm_keyslot_evict;
1309 profile->max_dun_bytes_supported = UINT_MAX;
1310 memset(profile->modes_supported, 0xFF,
1311 sizeof(profile->modes_supported));
1312
1313 for (i = 0; i < t->num_targets; i++) {
1314 struct dm_target *ti = dm_table_get_target(t, i);
1315
1316 if (!dm_target_passes_crypto(ti->type)) {
1317 blk_crypto_intersect_capabilities(profile, NULL);
1318 break;
1319 }
1320 if (!ti->type->iterate_devices)
1321 continue;
1322 ti->type->iterate_devices(ti,
1323 device_intersect_crypto_capabilities,
1324 profile);
1325 }
1326
1327 if (t->md->queue &&
1328 !blk_crypto_has_capabilities(profile,
1329 t->md->queue->crypto_profile)) {
1330 DMERR("Inline encryption capabilities of new DM table were more restrictive than the old table's. This is not supported!");
1331 dm_destroy_crypto_profile(profile);
1332 return -EINVAL;
1333 }
1334
1335 /*
1336 * If the new profile doesn't actually support any crypto capabilities,
1337 * we may as well represent it with a NULL profile.
1338 */
1339 for (i = 0; i < ARRAY_SIZE(profile->modes_supported); i++) {
1340 if (profile->modes_supported[i]) {
1341 empty_profile = false;
1342 break;
1343 }
1344 }
1345
1346 if (empty_profile) {
1347 dm_destroy_crypto_profile(profile);
1348 profile = NULL;
1349 }
1350
1351 /*
1352 * t->crypto_profile is only set temporarily while the table is being
1353 * set up, and it gets set to NULL after the profile has been
1354 * transferred to the request_queue.
1355 */
1356 t->crypto_profile = profile;
1357
1358 return 0;
1359}
1360
1361static void dm_update_crypto_profile(struct request_queue *q,
1362 struct dm_table *t)
1363{
1364 if (!t->crypto_profile)
1365 return;
1366
1367 /* Make the crypto profile less restrictive. */
1368 if (!q->crypto_profile) {
1369 blk_crypto_register(t->crypto_profile, q);
1370 } else {
1371 blk_crypto_update_capabilities(q->crypto_profile,
1372 t->crypto_profile);
1373 dm_destroy_crypto_profile(t->crypto_profile);
1374 }
1375 t->crypto_profile = NULL;
1376}
1377
1378#else /* CONFIG_BLK_INLINE_ENCRYPTION */
1379
1380static int dm_table_construct_crypto_profile(struct dm_table *t)
1381{
1382 return 0;
1383}
1384
1385void dm_destroy_crypto_profile(struct blk_crypto_profile *profile)
1386{
1387}
1388
1389static void dm_table_destroy_crypto_profile(struct dm_table *t)
1390{
1391}
1392
1393static void dm_update_crypto_profile(struct request_queue *q,
1394 struct dm_table *t)
1395{
1396}
1397
1398#endif /* !CONFIG_BLK_INLINE_ENCRYPTION */
1399
1400/*
1401 * Prepares the table for use by building the indices,
1402 * setting the type, and allocating mempools.
1403 */
1404int dm_table_complete(struct dm_table *t)
1405{
1406 int r;
1407
1408 r = dm_table_determine_type(t);
1409 if (r) {
1410 DMERR("unable to determine table type");
1411 return r;
1412 }
1413
1414 r = dm_table_build_index(t);
1415 if (r) {
1416 DMERR("unable to build btrees");
1417 return r;
1418 }
1419
1420 r = dm_table_register_integrity(t);
1421 if (r) {
1422 DMERR("could not register integrity profile.");
1423 return r;
1424 }
1425
1426 r = dm_table_construct_crypto_profile(t);
1427 if (r) {
1428 DMERR("could not construct crypto profile.");
1429 return r;
1430 }
1431
1432 r = dm_table_alloc_md_mempools(t, t->md);
1433 if (r)
1434 DMERR("unable to allocate mempools");
1435
1436 return r;
1437}
1438
1439static DEFINE_MUTEX(_event_lock);
1440void dm_table_event_callback(struct dm_table *t,
1441 void (*fn)(void *), void *context)
1442{
1443 mutex_lock(&_event_lock);
1444 t->event_fn = fn;
1445 t->event_context = context;
1446 mutex_unlock(&_event_lock);
1447}
1448
1449void dm_table_event(struct dm_table *t)
1450{
1451 mutex_lock(&_event_lock);
1452 if (t->event_fn)
1453 t->event_fn(t->event_context);
1454 mutex_unlock(&_event_lock);
1455}
1456EXPORT_SYMBOL(dm_table_event);
1457
1458inline sector_t dm_table_get_size(struct dm_table *t)
1459{
1460 return t->num_targets ? (t->highs[t->num_targets - 1] + 1) : 0;
1461}
1462EXPORT_SYMBOL(dm_table_get_size);
1463
1464/*
1465 * Search the btree for the correct target.
1466 *
1467 * Caller should check returned pointer for NULL
1468 * to trap I/O beyond end of device.
1469 */
1470struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector)
1471{
1472 unsigned int l, n = 0, k = 0;
1473 sector_t *node;
1474
1475 if (unlikely(sector >= dm_table_get_size(t)))
1476 return NULL;
1477
1478 for (l = 0; l < t->depth; l++) {
1479 n = get_child(n, k);
1480 node = get_node(t, l, n);
1481
1482 for (k = 0; k < KEYS_PER_NODE; k++)
1483 if (node[k] >= sector)
1484 break;
1485 }
1486
1487 return &t->targets[(KEYS_PER_NODE * n) + k];
1488}
1489
1490static int device_not_poll_capable(struct dm_target *ti, struct dm_dev *dev,
1491 sector_t start, sector_t len, void *data)
1492{
1493 struct request_queue *q = bdev_get_queue(dev->bdev);
1494
1495 return !test_bit(QUEUE_FLAG_POLL, &q->queue_flags);
1496}
1497
1498/*
1499 * type->iterate_devices() should be called when the sanity check needs to
1500 * iterate and check all underlying data devices. iterate_devices() will
1501 * iterate all underlying data devices until it encounters a non-zero return
1502 * code, returned by whether the input iterate_devices_callout_fn, or
1503 * iterate_devices() itself internally.
1504 *
1505 * For some target type (e.g. dm-stripe), one call of iterate_devices() may
1506 * iterate multiple underlying devices internally, in which case a non-zero
1507 * return code returned by iterate_devices_callout_fn will stop the iteration
1508 * in advance.
1509 *
1510 * Cases requiring _any_ underlying device supporting some kind of attribute,
1511 * should use the iteration structure like dm_table_any_dev_attr(), or call
1512 * it directly. @func should handle semantics of positive examples, e.g.
1513 * capable of something.
1514 *
1515 * Cases requiring _all_ underlying devices supporting some kind of attribute,
1516 * should use the iteration structure like dm_table_supports_nowait() or
1517 * dm_table_supports_discards(). Or introduce dm_table_all_devs_attr() that
1518 * uses an @anti_func that handle semantics of counter examples, e.g. not
1519 * capable of something. So: return !dm_table_any_dev_attr(t, anti_func, data);
1520 */
1521static bool dm_table_any_dev_attr(struct dm_table *t,
1522 iterate_devices_callout_fn func, void *data)
1523{
1524 for (unsigned int i = 0; i < t->num_targets; i++) {
1525 struct dm_target *ti = dm_table_get_target(t, i);
1526
1527 if (ti->type->iterate_devices &&
1528 ti->type->iterate_devices(ti, func, data))
1529 return true;
1530 }
1531
1532 return false;
1533}
1534
1535static int count_device(struct dm_target *ti, struct dm_dev *dev,
1536 sector_t start, sector_t len, void *data)
1537{
1538 unsigned *num_devices = data;
1539
1540 (*num_devices)++;
1541
1542 return 0;
1543}
1544
1545static bool dm_table_supports_poll(struct dm_table *t)
1546{
1547 for (unsigned int i = 0; i < t->num_targets; i++) {
1548 struct dm_target *ti = dm_table_get_target(t, i);
1549
1550 if (!ti->type->iterate_devices ||
1551 ti->type->iterate_devices(ti, device_not_poll_capable, NULL))
1552 return false;
1553 }
1554
1555 return true;
1556}
1557
1558/*
1559 * Check whether a table has no data devices attached using each
1560 * target's iterate_devices method.
1561 * Returns false if the result is unknown because a target doesn't
1562 * support iterate_devices.
1563 */
1564bool dm_table_has_no_data_devices(struct dm_table *t)
1565{
1566 for (unsigned int i = 0; i < t->num_targets; i++) {
1567 struct dm_target *ti = dm_table_get_target(t, i);
1568 unsigned num_devices = 0;
1569
1570 if (!ti->type->iterate_devices)
1571 return false;
1572
1573 ti->type->iterate_devices(ti, count_device, &num_devices);
1574 if (num_devices)
1575 return false;
1576 }
1577
1578 return true;
1579}
1580
1581static int device_not_zoned_model(struct dm_target *ti, struct dm_dev *dev,
1582 sector_t start, sector_t len, void *data)
1583{
1584 struct request_queue *q = bdev_get_queue(dev->bdev);
1585 enum blk_zoned_model *zoned_model = data;
1586
1587 return blk_queue_zoned_model(q) != *zoned_model;
1588}
1589
1590/*
1591 * Check the device zoned model based on the target feature flag. If the target
1592 * has the DM_TARGET_ZONED_HM feature flag set, host-managed zoned devices are
1593 * also accepted but all devices must have the same zoned model. If the target
1594 * has the DM_TARGET_MIXED_ZONED_MODEL feature set, the devices can have any
1595 * zoned model with all zoned devices having the same zone size.
1596 */
1597static bool dm_table_supports_zoned_model(struct dm_table *t,
1598 enum blk_zoned_model zoned_model)
1599{
1600 for (unsigned int i = 0; i < t->num_targets; i++) {
1601 struct dm_target *ti = dm_table_get_target(t, i);
1602
1603 if (dm_target_supports_zoned_hm(ti->type)) {
1604 if (!ti->type->iterate_devices ||
1605 ti->type->iterate_devices(ti, device_not_zoned_model,
1606 &zoned_model))
1607 return false;
1608 } else if (!dm_target_supports_mixed_zoned_model(ti->type)) {
1609 if (zoned_model == BLK_ZONED_HM)
1610 return false;
1611 }
1612 }
1613
1614 return true;
1615}
1616
1617static int device_not_matches_zone_sectors(struct dm_target *ti, struct dm_dev *dev,
1618 sector_t start, sector_t len, void *data)
1619{
1620 unsigned int *zone_sectors = data;
1621
1622 if (!bdev_is_zoned(dev->bdev))
1623 return 0;
1624 return bdev_zone_sectors(dev->bdev) != *zone_sectors;
1625}
1626
1627/*
1628 * Check consistency of zoned model and zone sectors across all targets. For
1629 * zone sectors, if the destination device is a zoned block device, it shall
1630 * have the specified zone_sectors.
1631 */
1632static int validate_hardware_zoned_model(struct dm_table *t,
1633 enum blk_zoned_model zoned_model,
1634 unsigned int zone_sectors)
1635{
1636 if (zoned_model == BLK_ZONED_NONE)
1637 return 0;
1638
1639 if (!dm_table_supports_zoned_model(t, zoned_model)) {
1640 DMERR("%s: zoned model is not consistent across all devices",
1641 dm_device_name(t->md));
1642 return -EINVAL;
1643 }
1644
1645 /* Check zone size validity and compatibility */
1646 if (!zone_sectors || !is_power_of_2(zone_sectors))
1647 return -EINVAL;
1648
1649 if (dm_table_any_dev_attr(t, device_not_matches_zone_sectors, &zone_sectors)) {
1650 DMERR("%s: zone sectors is not consistent across all zoned devices",
1651 dm_device_name(t->md));
1652 return -EINVAL;
1653 }
1654
1655 return 0;
1656}
1657
1658/*
1659 * Establish the new table's queue_limits and validate them.
1660 */
1661int dm_calculate_queue_limits(struct dm_table *t,
1662 struct queue_limits *limits)
1663{
1664 struct queue_limits ti_limits;
1665 enum blk_zoned_model zoned_model = BLK_ZONED_NONE;
1666 unsigned int zone_sectors = 0;
1667
1668 blk_set_stacking_limits(limits);
1669
1670 for (unsigned int i = 0; i < t->num_targets; i++) {
1671 struct dm_target *ti = dm_table_get_target(t, i);
1672
1673 blk_set_stacking_limits(&ti_limits);
1674
1675 if (!ti->type->iterate_devices)
1676 goto combine_limits;
1677
1678 /*
1679 * Combine queue limits of all the devices this target uses.
1680 */
1681 ti->type->iterate_devices(ti, dm_set_device_limits,
1682 &ti_limits);
1683
1684 if (zoned_model == BLK_ZONED_NONE && ti_limits.zoned != BLK_ZONED_NONE) {
1685 /*
1686 * After stacking all limits, validate all devices
1687 * in table support this zoned model and zone sectors.
1688 */
1689 zoned_model = ti_limits.zoned;
1690 zone_sectors = ti_limits.chunk_sectors;
1691 }
1692
1693 /* Set I/O hints portion of queue limits */
1694 if (ti->type->io_hints)
1695 ti->type->io_hints(ti, &ti_limits);
1696
1697 /*
1698 * Check each device area is consistent with the target's
1699 * overall queue limits.
1700 */
1701 if (ti->type->iterate_devices(ti, device_area_is_invalid,
1702 &ti_limits))
1703 return -EINVAL;
1704
1705combine_limits:
1706 /*
1707 * Merge this target's queue limits into the overall limits
1708 * for the table.
1709 */
1710 if (blk_stack_limits(limits, &ti_limits, 0) < 0)
1711 DMWARN("%s: adding target device "
1712 "(start sect %llu len %llu) "
1713 "caused an alignment inconsistency",
1714 dm_device_name(t->md),
1715 (unsigned long long) ti->begin,
1716 (unsigned long long) ti->len);
1717 }
1718
1719 /*
1720 * Verify that the zoned model and zone sectors, as determined before
1721 * any .io_hints override, are the same across all devices in the table.
1722 * - this is especially relevant if .io_hints is emulating a disk-managed
1723 * zoned model (aka BLK_ZONED_NONE) on host-managed zoned block devices.
1724 * BUT...
1725 */
1726 if (limits->zoned != BLK_ZONED_NONE) {
1727 /*
1728 * ...IF the above limits stacking determined a zoned model
1729 * validate that all of the table's devices conform to it.
1730 */
1731 zoned_model = limits->zoned;
1732 zone_sectors = limits->chunk_sectors;
1733 }
1734 if (validate_hardware_zoned_model(t, zoned_model, zone_sectors))
1735 return -EINVAL;
1736
1737 return validate_hardware_logical_block_alignment(t, limits);
1738}
1739
1740/*
1741 * Verify that all devices have an integrity profile that matches the
1742 * DM device's registered integrity profile. If the profiles don't
1743 * match then unregister the DM device's integrity profile.
1744 */
1745static void dm_table_verify_integrity(struct dm_table *t)
1746{
1747 struct gendisk *template_disk = NULL;
1748
1749 if (t->integrity_added)
1750 return;
1751
1752 if (t->integrity_supported) {
1753 /*
1754 * Verify that the original integrity profile
1755 * matches all the devices in this table.
1756 */
1757 template_disk = dm_table_get_integrity_disk(t);
1758 if (template_disk &&
1759 blk_integrity_compare(dm_disk(t->md), template_disk) >= 0)
1760 return;
1761 }
1762
1763 if (integrity_profile_exists(dm_disk(t->md))) {
1764 DMWARN("%s: unable to establish an integrity profile",
1765 dm_device_name(t->md));
1766 blk_integrity_unregister(dm_disk(t->md));
1767 }
1768}
1769
1770static int device_flush_capable(struct dm_target *ti, struct dm_dev *dev,
1771 sector_t start, sector_t len, void *data)
1772{
1773 unsigned long flush = (unsigned long) data;
1774 struct request_queue *q = bdev_get_queue(dev->bdev);
1775
1776 return (q->queue_flags & flush);
1777}
1778
1779static bool dm_table_supports_flush(struct dm_table *t, unsigned long flush)
1780{
1781 /*
1782 * Require at least one underlying device to support flushes.
1783 * t->devices includes internal dm devices such as mirror logs
1784 * so we need to use iterate_devices here, which targets
1785 * supporting flushes must provide.
1786 */
1787 for (unsigned int i = 0; i < t->num_targets; i++) {
1788 struct dm_target *ti = dm_table_get_target(t, i);
1789
1790 if (!ti->num_flush_bios)
1791 continue;
1792
1793 if (ti->flush_supported)
1794 return true;
1795
1796 if (ti->type->iterate_devices &&
1797 ti->type->iterate_devices(ti, device_flush_capable, (void *) flush))
1798 return true;
1799 }
1800
1801 return false;
1802}
1803
1804static int device_dax_write_cache_enabled(struct dm_target *ti,
1805 struct dm_dev *dev, sector_t start,
1806 sector_t len, void *data)
1807{
1808 struct dax_device *dax_dev = dev->dax_dev;
1809
1810 if (!dax_dev)
1811 return false;
1812
1813 if (dax_write_cache_enabled(dax_dev))
1814 return true;
1815 return false;
1816}
1817
1818static int device_is_rotational(struct dm_target *ti, struct dm_dev *dev,
1819 sector_t start, sector_t len, void *data)
1820{
1821 return !bdev_nonrot(dev->bdev);
1822}
1823
1824static int device_is_not_random(struct dm_target *ti, struct dm_dev *dev,
1825 sector_t start, sector_t len, void *data)
1826{
1827 struct request_queue *q = bdev_get_queue(dev->bdev);
1828
1829 return !blk_queue_add_random(q);
1830}
1831
1832static int device_not_write_zeroes_capable(struct dm_target *ti, struct dm_dev *dev,
1833 sector_t start, sector_t len, void *data)
1834{
1835 struct request_queue *q = bdev_get_queue(dev->bdev);
1836
1837 return !q->limits.max_write_zeroes_sectors;
1838}
1839
1840static bool dm_table_supports_write_zeroes(struct dm_table *t)
1841{
1842 for (unsigned int i = 0; i < t->num_targets; i++) {
1843 struct dm_target *ti = dm_table_get_target(t, i);
1844
1845 if (!ti->num_write_zeroes_bios)
1846 return false;
1847
1848 if (!ti->type->iterate_devices ||
1849 ti->type->iterate_devices(ti, device_not_write_zeroes_capable, NULL))
1850 return false;
1851 }
1852
1853 return true;
1854}
1855
1856static int device_not_nowait_capable(struct dm_target *ti, struct dm_dev *dev,
1857 sector_t start, sector_t len, void *data)
1858{
1859 return !bdev_nowait(dev->bdev);
1860}
1861
1862static bool dm_table_supports_nowait(struct dm_table *t)
1863{
1864 for (unsigned int i = 0; i < t->num_targets; i++) {
1865 struct dm_target *ti = dm_table_get_target(t, i);
1866
1867 if (!dm_target_supports_nowait(ti->type))
1868 return false;
1869
1870 if (!ti->type->iterate_devices ||
1871 ti->type->iterate_devices(ti, device_not_nowait_capable, NULL))
1872 return false;
1873 }
1874
1875 return true;
1876}
1877
1878static int device_not_discard_capable(struct dm_target *ti, struct dm_dev *dev,
1879 sector_t start, sector_t len, void *data)
1880{
1881 return !bdev_max_discard_sectors(dev->bdev);
1882}
1883
1884static bool dm_table_supports_discards(struct dm_table *t)
1885{
1886 for (unsigned int i = 0; i < t->num_targets; i++) {
1887 struct dm_target *ti = dm_table_get_target(t, i);
1888
1889 if (!ti->num_discard_bios)
1890 return false;
1891
1892 /*
1893 * Either the target provides discard support (as implied by setting
1894 * 'discards_supported') or it relies on _all_ data devices having
1895 * discard support.
1896 */
1897 if (!ti->discards_supported &&
1898 (!ti->type->iterate_devices ||
1899 ti->type->iterate_devices(ti, device_not_discard_capable, NULL)))
1900 return false;
1901 }
1902
1903 return true;
1904}
1905
1906static int device_not_secure_erase_capable(struct dm_target *ti,
1907 struct dm_dev *dev, sector_t start,
1908 sector_t len, void *data)
1909{
1910 return !bdev_max_secure_erase_sectors(dev->bdev);
1911}
1912
1913static bool dm_table_supports_secure_erase(struct dm_table *t)
1914{
1915 for (unsigned int i = 0; i < t->num_targets; i++) {
1916 struct dm_target *ti = dm_table_get_target(t, i);
1917
1918 if (!ti->num_secure_erase_bios)
1919 return false;
1920
1921 if (!ti->type->iterate_devices ||
1922 ti->type->iterate_devices(ti, device_not_secure_erase_capable, NULL))
1923 return false;
1924 }
1925
1926 return true;
1927}
1928
1929static int device_requires_stable_pages(struct dm_target *ti,
1930 struct dm_dev *dev, sector_t start,
1931 sector_t len, void *data)
1932{
1933 return bdev_stable_writes(dev->bdev);
1934}
1935
1936int dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
1937 struct queue_limits *limits)
1938{
1939 bool wc = false, fua = false;
1940 int r;
1941
1942 /*
1943 * Copy table's limits to the DM device's request_queue
1944 */
1945 q->limits = *limits;
1946
1947 if (dm_table_supports_nowait(t))
1948 blk_queue_flag_set(QUEUE_FLAG_NOWAIT, q);
1949 else
1950 blk_queue_flag_clear(QUEUE_FLAG_NOWAIT, q);
1951
1952 if (!dm_table_supports_discards(t)) {
1953 q->limits.max_discard_sectors = 0;
1954 q->limits.max_hw_discard_sectors = 0;
1955 q->limits.discard_granularity = 0;
1956 q->limits.discard_alignment = 0;
1957 q->limits.discard_misaligned = 0;
1958 }
1959
1960 if (!dm_table_supports_secure_erase(t))
1961 q->limits.max_secure_erase_sectors = 0;
1962
1963 if (dm_table_supports_flush(t, (1UL << QUEUE_FLAG_WC))) {
1964 wc = true;
1965 if (dm_table_supports_flush(t, (1UL << QUEUE_FLAG_FUA)))
1966 fua = true;
1967 }
1968 blk_queue_write_cache(q, wc, fua);
1969
1970 if (dm_table_supports_dax(t, device_not_dax_capable)) {
1971 blk_queue_flag_set(QUEUE_FLAG_DAX, q);
1972 if (dm_table_supports_dax(t, device_not_dax_synchronous_capable))
1973 set_dax_synchronous(t->md->dax_dev);
1974 }
1975 else
1976 blk_queue_flag_clear(QUEUE_FLAG_DAX, q);
1977
1978 if (dm_table_any_dev_attr(t, device_dax_write_cache_enabled, NULL))
1979 dax_write_cache(t->md->dax_dev, true);
1980
1981 /* Ensure that all underlying devices are non-rotational. */
1982 if (dm_table_any_dev_attr(t, device_is_rotational, NULL))
1983 blk_queue_flag_clear(QUEUE_FLAG_NONROT, q);
1984 else
1985 blk_queue_flag_set(QUEUE_FLAG_NONROT, q);
1986
1987 if (!dm_table_supports_write_zeroes(t))
1988 q->limits.max_write_zeroes_sectors = 0;
1989
1990 dm_table_verify_integrity(t);
1991
1992 /*
1993 * Some devices don't use blk_integrity but still want stable pages
1994 * because they do their own checksumming.
1995 * If any underlying device requires stable pages, a table must require
1996 * them as well. Only targets that support iterate_devices are considered:
1997 * don't want error, zero, etc to require stable pages.
1998 */
1999 if (dm_table_any_dev_attr(t, device_requires_stable_pages, NULL))
2000 blk_queue_flag_set(QUEUE_FLAG_STABLE_WRITES, q);
2001 else
2002 blk_queue_flag_clear(QUEUE_FLAG_STABLE_WRITES, q);
2003
2004 /*
2005 * Determine whether or not this queue's I/O timings contribute
2006 * to the entropy pool, Only request-based targets use this.
2007 * Clear QUEUE_FLAG_ADD_RANDOM if any underlying device does not
2008 * have it set.
2009 */
2010 if (blk_queue_add_random(q) &&
2011 dm_table_any_dev_attr(t, device_is_not_random, NULL))
2012 blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, q);
2013
2014 /*
2015 * For a zoned target, setup the zones related queue attributes
2016 * and resources necessary for zone append emulation if necessary.
2017 */
2018 if (blk_queue_is_zoned(q)) {
2019 r = dm_set_zones_restrictions(t, q);
2020 if (r)
2021 return r;
2022 if (!static_key_enabled(&zoned_enabled.key))
2023 static_branch_enable(&zoned_enabled);
2024 }
2025
2026 dm_update_crypto_profile(q, t);
2027 disk_update_readahead(t->md->disk);
2028
2029 /*
2030 * Check for request-based device is left to
2031 * dm_mq_init_request_queue()->blk_mq_init_allocated_queue().
2032 *
2033 * For bio-based device, only set QUEUE_FLAG_POLL when all
2034 * underlying devices supporting polling.
2035 */
2036 if (__table_type_bio_based(t->type)) {
2037 if (dm_table_supports_poll(t))
2038 blk_queue_flag_set(QUEUE_FLAG_POLL, q);
2039 else
2040 blk_queue_flag_clear(QUEUE_FLAG_POLL, q);
2041 }
2042
2043 return 0;
2044}
2045
2046struct list_head *dm_table_get_devices(struct dm_table *t)
2047{
2048 return &t->devices;
2049}
2050
2051fmode_t dm_table_get_mode(struct dm_table *t)
2052{
2053 return t->mode;
2054}
2055EXPORT_SYMBOL(dm_table_get_mode);
2056
2057enum suspend_mode {
2058 PRESUSPEND,
2059 PRESUSPEND_UNDO,
2060 POSTSUSPEND,
2061};
2062
2063static void suspend_targets(struct dm_table *t, enum suspend_mode mode)
2064{
2065 lockdep_assert_held(&t->md->suspend_lock);
2066
2067 for (unsigned int i = 0; i < t->num_targets; i++) {
2068 struct dm_target *ti = dm_table_get_target(t, i);
2069
2070 switch (mode) {
2071 case PRESUSPEND:
2072 if (ti->type->presuspend)
2073 ti->type->presuspend(ti);
2074 break;
2075 case PRESUSPEND_UNDO:
2076 if (ti->type->presuspend_undo)
2077 ti->type->presuspend_undo(ti);
2078 break;
2079 case POSTSUSPEND:
2080 if (ti->type->postsuspend)
2081 ti->type->postsuspend(ti);
2082 break;
2083 }
2084 }
2085}
2086
2087void dm_table_presuspend_targets(struct dm_table *t)
2088{
2089 if (!t)
2090 return;
2091
2092 suspend_targets(t, PRESUSPEND);
2093}
2094
2095void dm_table_presuspend_undo_targets(struct dm_table *t)
2096{
2097 if (!t)
2098 return;
2099
2100 suspend_targets(t, PRESUSPEND_UNDO);
2101}
2102
2103void dm_table_postsuspend_targets(struct dm_table *t)
2104{
2105 if (!t)
2106 return;
2107
2108 suspend_targets(t, POSTSUSPEND);
2109}
2110
2111int dm_table_resume_targets(struct dm_table *t)
2112{
2113 unsigned int i;
2114 int r = 0;
2115
2116 lockdep_assert_held(&t->md->suspend_lock);
2117
2118 for (i = 0; i < t->num_targets; i++) {
2119 struct dm_target *ti = dm_table_get_target(t, i);
2120
2121 if (!ti->type->preresume)
2122 continue;
2123
2124 r = ti->type->preresume(ti);
2125 if (r) {
2126 DMERR("%s: %s: preresume failed, error = %d",
2127 dm_device_name(t->md), ti->type->name, r);
2128 return r;
2129 }
2130 }
2131
2132 for (i = 0; i < t->num_targets; i++) {
2133 struct dm_target *ti = dm_table_get_target(t, i);
2134
2135 if (ti->type->resume)
2136 ti->type->resume(ti);
2137 }
2138
2139 return 0;
2140}
2141
2142struct mapped_device *dm_table_get_md(struct dm_table *t)
2143{
2144 return t->md;
2145}
2146EXPORT_SYMBOL(dm_table_get_md);
2147
2148const char *dm_table_device_name(struct dm_table *t)
2149{
2150 return dm_device_name(t->md);
2151}
2152EXPORT_SYMBOL_GPL(dm_table_device_name);
2153
2154void dm_table_run_md_queue_async(struct dm_table *t)
2155{
2156 if (!dm_table_request_based(t))
2157 return;
2158
2159 if (t->md->queue)
2160 blk_mq_run_hw_queues(t->md->queue, true);
2161}
2162EXPORT_SYMBOL(dm_table_run_md_queue_async);
2163
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.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
22#define DM_MSG_PREFIX "table"
23
24#define MAX_DEPTH 16
25#define NODE_SIZE L1_CACHE_BYTES
26#define KEYS_PER_NODE (NODE_SIZE / sizeof(sector_t))
27#define CHILDREN_PER_NODE (KEYS_PER_NODE + 1)
28
29struct dm_table {
30 struct mapped_device *md;
31 unsigned type;
32
33 /* btree table */
34 unsigned int depth;
35 unsigned int counts[MAX_DEPTH]; /* in nodes */
36 sector_t *index[MAX_DEPTH];
37
38 unsigned int num_targets;
39 unsigned int num_allocated;
40 sector_t *highs;
41 struct dm_target *targets;
42
43 struct target_type *immutable_target_type;
44 unsigned integrity_supported:1;
45 unsigned singleton:1;
46
47 /*
48 * Indicates the rw permissions for the new logical
49 * device. This should be a combination of FMODE_READ
50 * and FMODE_WRITE.
51 */
52 fmode_t mode;
53
54 /* a list of devices used by this table */
55 struct list_head devices;
56
57 /* events get handed up using this callback */
58 void (*event_fn)(void *);
59 void *event_context;
60
61 struct dm_md_mempools *mempools;
62
63 struct list_head target_callbacks;
64};
65
66/*
67 * Similar to ceiling(log_size(n))
68 */
69static unsigned int int_log(unsigned int n, unsigned int base)
70{
71 int result = 0;
72
73 while (n > 1) {
74 n = dm_div_up(n, base);
75 result++;
76 }
77
78 return result;
79}
80
81/*
82 * Calculate the index of the child node of the n'th node k'th key.
83 */
84static inline unsigned int get_child(unsigned int n, unsigned int k)
85{
86 return (n * CHILDREN_PER_NODE) + k;
87}
88
89/*
90 * Return the n'th node of level l from table t.
91 */
92static inline sector_t *get_node(struct dm_table *t,
93 unsigned int l, unsigned int n)
94{
95 return t->index[l] + (n * KEYS_PER_NODE);
96}
97
98/*
99 * Return the highest key that you could lookup from the n'th
100 * node on level l of the btree.
101 */
102static sector_t high(struct dm_table *t, unsigned int l, unsigned int n)
103{
104 for (; l < t->depth - 1; l++)
105 n = get_child(n, CHILDREN_PER_NODE - 1);
106
107 if (n >= t->counts[l])
108 return (sector_t) - 1;
109
110 return get_node(t, l, n)[KEYS_PER_NODE - 1];
111}
112
113/*
114 * Fills in a level of the btree based on the highs of the level
115 * below it.
116 */
117static int setup_btree_index(unsigned int l, struct dm_table *t)
118{
119 unsigned int n, k;
120 sector_t *node;
121
122 for (n = 0U; n < t->counts[l]; n++) {
123 node = get_node(t, l, n);
124
125 for (k = 0U; k < KEYS_PER_NODE; k++)
126 node[k] = high(t, l + 1, get_child(n, k));
127 }
128
129 return 0;
130}
131
132void *dm_vcalloc(unsigned long nmemb, unsigned long elem_size)
133{
134 unsigned long size;
135 void *addr;
136
137 /*
138 * Check that we're not going to overflow.
139 */
140 if (nmemb > (ULONG_MAX / elem_size))
141 return NULL;
142
143 size = nmemb * elem_size;
144 addr = vzalloc(size);
145
146 return addr;
147}
148EXPORT_SYMBOL(dm_vcalloc);
149
150/*
151 * highs, and targets are managed as dynamic arrays during a
152 * table load.
153 */
154static int alloc_targets(struct dm_table *t, unsigned int num)
155{
156 sector_t *n_highs;
157 struct dm_target *n_targets;
158
159 /*
160 * Allocate both the target array and offset array at once.
161 * Append an empty entry to catch sectors beyond the end of
162 * the device.
163 */
164 n_highs = (sector_t *) dm_vcalloc(num + 1, sizeof(struct dm_target) +
165 sizeof(sector_t));
166 if (!n_highs)
167 return -ENOMEM;
168
169 n_targets = (struct dm_target *) (n_highs + num);
170
171 memset(n_highs, -1, sizeof(*n_highs) * num);
172 vfree(t->highs);
173
174 t->num_allocated = num;
175 t->highs = n_highs;
176 t->targets = n_targets;
177
178 return 0;
179}
180
181int dm_table_create(struct dm_table **result, fmode_t mode,
182 unsigned num_targets, struct mapped_device *md)
183{
184 struct dm_table *t = kzalloc(sizeof(*t), GFP_KERNEL);
185
186 if (!t)
187 return -ENOMEM;
188
189 INIT_LIST_HEAD(&t->devices);
190 INIT_LIST_HEAD(&t->target_callbacks);
191
192 if (!num_targets)
193 num_targets = KEYS_PER_NODE;
194
195 num_targets = dm_round_up(num_targets, KEYS_PER_NODE);
196
197 if (!num_targets) {
198 kfree(t);
199 return -ENOMEM;
200 }
201
202 if (alloc_targets(t, num_targets)) {
203 kfree(t);
204 return -ENOMEM;
205 }
206
207 t->mode = mode;
208 t->md = md;
209 *result = t;
210 return 0;
211}
212
213static void free_devices(struct list_head *devices)
214{
215 struct list_head *tmp, *next;
216
217 list_for_each_safe(tmp, next, devices) {
218 struct dm_dev_internal *dd =
219 list_entry(tmp, struct dm_dev_internal, list);
220 DMWARN("dm_table_destroy: dm_put_device call missing for %s",
221 dd->dm_dev.name);
222 kfree(dd);
223 }
224}
225
226void dm_table_destroy(struct dm_table *t)
227{
228 unsigned int i;
229
230 if (!t)
231 return;
232
233 /* free the indexes */
234 if (t->depth >= 2)
235 vfree(t->index[t->depth - 2]);
236
237 /* free the targets */
238 for (i = 0; i < t->num_targets; i++) {
239 struct dm_target *tgt = t->targets + i;
240
241 if (tgt->type->dtr)
242 tgt->type->dtr(tgt);
243
244 dm_put_target_type(tgt->type);
245 }
246
247 vfree(t->highs);
248
249 /* free the device list */
250 free_devices(&t->devices);
251
252 dm_free_md_mempools(t->mempools);
253
254 kfree(t);
255}
256
257/*
258 * See if we've already got a device in the list.
259 */
260static struct dm_dev_internal *find_device(struct list_head *l, dev_t dev)
261{
262 struct dm_dev_internal *dd;
263
264 list_for_each_entry (dd, l, list)
265 if (dd->dm_dev.bdev->bd_dev == dev)
266 return dd;
267
268 return NULL;
269}
270
271/*
272 * Open a device so we can use it as a map destination.
273 */
274static int open_dev(struct dm_dev_internal *d, dev_t dev,
275 struct mapped_device *md)
276{
277 static char *_claim_ptr = "I belong to device-mapper";
278 struct block_device *bdev;
279
280 int r;
281
282 BUG_ON(d->dm_dev.bdev);
283
284 bdev = blkdev_get_by_dev(dev, d->dm_dev.mode | FMODE_EXCL, _claim_ptr);
285 if (IS_ERR(bdev))
286 return PTR_ERR(bdev);
287
288 r = bd_link_disk_holder(bdev, dm_disk(md));
289 if (r) {
290 blkdev_put(bdev, d->dm_dev.mode | FMODE_EXCL);
291 return r;
292 }
293
294 d->dm_dev.bdev = bdev;
295 return 0;
296}
297
298/*
299 * Close a device that we've been using.
300 */
301static void close_dev(struct dm_dev_internal *d, struct mapped_device *md)
302{
303 if (!d->dm_dev.bdev)
304 return;
305
306 bd_unlink_disk_holder(d->dm_dev.bdev, dm_disk(md));
307 blkdev_put(d->dm_dev.bdev, d->dm_dev.mode | FMODE_EXCL);
308 d->dm_dev.bdev = NULL;
309}
310
311/*
312 * If possible, this checks an area of a destination device is invalid.
313 */
314static int device_area_is_invalid(struct dm_target *ti, struct dm_dev *dev,
315 sector_t start, sector_t len, void *data)
316{
317 struct request_queue *q;
318 struct queue_limits *limits = data;
319 struct block_device *bdev = dev->bdev;
320 sector_t dev_size =
321 i_size_read(bdev->bd_inode) >> SECTOR_SHIFT;
322 unsigned short logical_block_size_sectors =
323 limits->logical_block_size >> SECTOR_SHIFT;
324 char b[BDEVNAME_SIZE];
325
326 /*
327 * Some devices exist without request functions,
328 * such as loop devices not yet bound to backing files.
329 * Forbid the use of such devices.
330 */
331 q = bdev_get_queue(bdev);
332 if (!q || !q->make_request_fn) {
333 DMWARN("%s: %s is not yet initialised: "
334 "start=%llu, len=%llu, dev_size=%llu",
335 dm_device_name(ti->table->md), bdevname(bdev, b),
336 (unsigned long long)start,
337 (unsigned long long)len,
338 (unsigned long long)dev_size);
339 return 1;
340 }
341
342 if (!dev_size)
343 return 0;
344
345 if ((start >= dev_size) || (start + len > dev_size)) {
346 DMWARN("%s: %s too small for target: "
347 "start=%llu, len=%llu, dev_size=%llu",
348 dm_device_name(ti->table->md), bdevname(bdev, b),
349 (unsigned long long)start,
350 (unsigned long long)len,
351 (unsigned long long)dev_size);
352 return 1;
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_internal dd_new, dd_old;
390
391 dd_new = dd_old = *dd;
392
393 dd_new.dm_dev.mode |= new_mode;
394 dd_new.dm_dev.bdev = NULL;
395
396 r = open_dev(&dd_new, dd->dm_dev.bdev->bd_dev, md);
397 if (r)
398 return r;
399
400 dd->dm_dev.mode |= new_mode;
401 close_dev(&dd_old, md);
402
403 return 0;
404}
405
406/*
407 * Add a device to the list, or just increment the usage count if
408 * it's already present.
409 */
410int dm_get_device(struct dm_target *ti, const char *path, fmode_t mode,
411 struct dm_dev **result)
412{
413 int r;
414 dev_t uninitialized_var(dev);
415 struct dm_dev_internal *dd;
416 unsigned int major, minor;
417 struct dm_table *t = ti->table;
418 char dummy;
419
420 BUG_ON(!t);
421
422 if (sscanf(path, "%u:%u%c", &major, &minor, &dummy) == 2) {
423 /* Extract the major/minor numbers */
424 dev = MKDEV(major, minor);
425 if (MAJOR(dev) != major || MINOR(dev) != minor)
426 return -EOVERFLOW;
427 } else {
428 /* convert the path to a device */
429 struct block_device *bdev = lookup_bdev(path);
430
431 if (IS_ERR(bdev))
432 return PTR_ERR(bdev);
433 dev = bdev->bd_dev;
434 bdput(bdev);
435 }
436
437 dd = find_device(&t->devices, dev);
438 if (!dd) {
439 dd = kmalloc(sizeof(*dd), GFP_KERNEL);
440 if (!dd)
441 return -ENOMEM;
442
443 dd->dm_dev.mode = mode;
444 dd->dm_dev.bdev = NULL;
445
446 if ((r = open_dev(dd, dev, t->md))) {
447 kfree(dd);
448 return r;
449 }
450
451 format_dev_t(dd->dm_dev.name, dev);
452
453 atomic_set(&dd->count, 0);
454 list_add(&dd->list, &t->devices);
455
456 } else if (dd->dm_dev.mode != (mode | dd->dm_dev.mode)) {
457 r = upgrade_mode(dd, mode, t->md);
458 if (r)
459 return r;
460 }
461 atomic_inc(&dd->count);
462
463 *result = &dd->dm_dev;
464 return 0;
465}
466EXPORT_SYMBOL(dm_get_device);
467
468int dm_set_device_limits(struct dm_target *ti, struct dm_dev *dev,
469 sector_t start, sector_t len, void *data)
470{
471 struct queue_limits *limits = data;
472 struct block_device *bdev = dev->bdev;
473 struct request_queue *q = bdev_get_queue(bdev);
474 char b[BDEVNAME_SIZE];
475
476 if (unlikely(!q)) {
477 DMWARN("%s: Cannot set limits for nonexistent device %s",
478 dm_device_name(ti->table->md), bdevname(bdev, b));
479 return 0;
480 }
481
482 if (bdev_stack_limits(limits, bdev, start) < 0)
483 DMWARN("%s: adding target device %s caused an alignment inconsistency: "
484 "physical_block_size=%u, logical_block_size=%u, "
485 "alignment_offset=%u, start=%llu",
486 dm_device_name(ti->table->md), bdevname(bdev, b),
487 q->limits.physical_block_size,
488 q->limits.logical_block_size,
489 q->limits.alignment_offset,
490 (unsigned long long) start << SECTOR_SHIFT);
491
492 /*
493 * Check if merge fn is supported.
494 * If not we'll force DM to use PAGE_SIZE or
495 * smaller I/O, just to be safe.
496 */
497 if (dm_queue_merge_is_compulsory(q) && !ti->type->merge)
498 blk_limits_max_hw_sectors(limits,
499 (unsigned int) (PAGE_SIZE >> 9));
500 return 0;
501}
502EXPORT_SYMBOL_GPL(dm_set_device_limits);
503
504/*
505 * Decrement a device's use count and remove it if necessary.
506 */
507void dm_put_device(struct dm_target *ti, struct dm_dev *d)
508{
509 struct dm_dev_internal *dd = container_of(d, struct dm_dev_internal,
510 dm_dev);
511
512 if (atomic_dec_and_test(&dd->count)) {
513 close_dev(dd, ti->table->md);
514 list_del(&dd->list);
515 kfree(dd);
516 }
517}
518EXPORT_SYMBOL(dm_put_device);
519
520/*
521 * Checks to see if the target joins onto the end of the table.
522 */
523static int adjoin(struct dm_table *table, struct dm_target *ti)
524{
525 struct dm_target *prev;
526
527 if (!table->num_targets)
528 return !ti->begin;
529
530 prev = &table->targets[table->num_targets - 1];
531 return (ti->begin == (prev->begin + prev->len));
532}
533
534/*
535 * Used to dynamically allocate the arg array.
536 *
537 * We do first allocation with GFP_NOIO because dm-mpath and dm-thin must
538 * process messages even if some device is suspended. These messages have a
539 * small fixed number of arguments.
540 *
541 * On the other hand, dm-switch needs to process bulk data using messages and
542 * excessive use of GFP_NOIO could cause trouble.
543 */
544static char **realloc_argv(unsigned *array_size, char **old_argv)
545{
546 char **argv;
547 unsigned new_size;
548 gfp_t gfp;
549
550 if (*array_size) {
551 new_size = *array_size * 2;
552 gfp = GFP_KERNEL;
553 } else {
554 new_size = 8;
555 gfp = GFP_NOIO;
556 }
557 argv = kmalloc(new_size * sizeof(*argv), gfp);
558 if (argv) {
559 memcpy(argv, old_argv, *array_size * sizeof(*argv));
560 *array_size = new_size;
561 }
562
563 kfree(old_argv);
564 return argv;
565}
566
567/*
568 * Destructively splits up the argument list to pass to ctr.
569 */
570int dm_split_args(int *argc, char ***argvp, char *input)
571{
572 char *start, *end = input, *out, **argv = NULL;
573 unsigned array_size = 0;
574
575 *argc = 0;
576
577 if (!input) {
578 *argvp = NULL;
579 return 0;
580 }
581
582 argv = realloc_argv(&array_size, argv);
583 if (!argv)
584 return -ENOMEM;
585
586 while (1) {
587 /* Skip whitespace */
588 start = skip_spaces(end);
589
590 if (!*start)
591 break; /* success, we hit the end */
592
593 /* 'out' is used to remove any back-quotes */
594 end = out = start;
595 while (*end) {
596 /* Everything apart from '\0' can be quoted */
597 if (*end == '\\' && *(end + 1)) {
598 *out++ = *(end + 1);
599 end += 2;
600 continue;
601 }
602
603 if (isspace(*end))
604 break; /* end of token */
605
606 *out++ = *end++;
607 }
608
609 /* have we already filled the array ? */
610 if ((*argc + 1) > array_size) {
611 argv = realloc_argv(&array_size, argv);
612 if (!argv)
613 return -ENOMEM;
614 }
615
616 /* we know this is whitespace */
617 if (*end)
618 end++;
619
620 /* terminate the string and put it in the array */
621 *out = '\0';
622 argv[*argc] = start;
623 (*argc)++;
624 }
625
626 *argvp = argv;
627 return 0;
628}
629
630/*
631 * Impose necessary and sufficient conditions on a devices's table such
632 * that any incoming bio which respects its logical_block_size can be
633 * processed successfully. If it falls across the boundary between
634 * two or more targets, the size of each piece it gets split into must
635 * be compatible with the logical_block_size of the target processing it.
636 */
637static int validate_hardware_logical_block_alignment(struct dm_table *table,
638 struct queue_limits *limits)
639{
640 /*
641 * This function uses arithmetic modulo the logical_block_size
642 * (in units of 512-byte sectors).
643 */
644 unsigned short device_logical_block_size_sects =
645 limits->logical_block_size >> SECTOR_SHIFT;
646
647 /*
648 * Offset of the start of the next table entry, mod logical_block_size.
649 */
650 unsigned short next_target_start = 0;
651
652 /*
653 * Given an aligned bio that extends beyond the end of a
654 * target, how many sectors must the next target handle?
655 */
656 unsigned short remaining = 0;
657
658 struct dm_target *uninitialized_var(ti);
659 struct queue_limits ti_limits;
660 unsigned i = 0;
661
662 /*
663 * Check each entry in the table in turn.
664 */
665 while (i < dm_table_get_num_targets(table)) {
666 ti = dm_table_get_target(table, i++);
667
668 blk_set_stacking_limits(&ti_limits);
669
670 /* combine all target devices' limits */
671 if (ti->type->iterate_devices)
672 ti->type->iterate_devices(ti, dm_set_device_limits,
673 &ti_limits);
674
675 /*
676 * If the remaining sectors fall entirely within this
677 * table entry are they compatible with its logical_block_size?
678 */
679 if (remaining < ti->len &&
680 remaining & ((ti_limits.logical_block_size >>
681 SECTOR_SHIFT) - 1))
682 break; /* Error */
683
684 next_target_start =
685 (unsigned short) ((next_target_start + ti->len) &
686 (device_logical_block_size_sects - 1));
687 remaining = next_target_start ?
688 device_logical_block_size_sects - next_target_start : 0;
689 }
690
691 if (remaining) {
692 DMWARN("%s: table line %u (start sect %llu len %llu) "
693 "not aligned to h/w logical block size %u",
694 dm_device_name(table->md), i,
695 (unsigned long long) ti->begin,
696 (unsigned long long) ti->len,
697 limits->logical_block_size);
698 return -EINVAL;
699 }
700
701 return 0;
702}
703
704int dm_table_add_target(struct dm_table *t, const char *type,
705 sector_t start, sector_t len, char *params)
706{
707 int r = -EINVAL, argc;
708 char **argv;
709 struct dm_target *tgt;
710
711 if (t->singleton) {
712 DMERR("%s: target type %s must appear alone in table",
713 dm_device_name(t->md), t->targets->type->name);
714 return -EINVAL;
715 }
716
717 BUG_ON(t->num_targets >= t->num_allocated);
718
719 tgt = t->targets + t->num_targets;
720 memset(tgt, 0, sizeof(*tgt));
721
722 if (!len) {
723 DMERR("%s: zero-length target", dm_device_name(t->md));
724 return -EINVAL;
725 }
726
727 tgt->type = dm_get_target_type(type);
728 if (!tgt->type) {
729 DMERR("%s: %s: unknown target type", dm_device_name(t->md),
730 type);
731 return -EINVAL;
732 }
733
734 if (dm_target_needs_singleton(tgt->type)) {
735 if (t->num_targets) {
736 DMERR("%s: target type %s must appear alone in table",
737 dm_device_name(t->md), type);
738 return -EINVAL;
739 }
740 t->singleton = 1;
741 }
742
743 if (dm_target_always_writeable(tgt->type) && !(t->mode & FMODE_WRITE)) {
744 DMERR("%s: target type %s may not be included in read-only tables",
745 dm_device_name(t->md), type);
746 return -EINVAL;
747 }
748
749 if (t->immutable_target_type) {
750 if (t->immutable_target_type != tgt->type) {
751 DMERR("%s: immutable target type %s cannot be mixed with other target types",
752 dm_device_name(t->md), t->immutable_target_type->name);
753 return -EINVAL;
754 }
755 } else if (dm_target_is_immutable(tgt->type)) {
756 if (t->num_targets) {
757 DMERR("%s: immutable target type %s cannot be mixed with other target types",
758 dm_device_name(t->md), tgt->type->name);
759 return -EINVAL;
760 }
761 t->immutable_target_type = tgt->type;
762 }
763
764 tgt->table = t;
765 tgt->begin = start;
766 tgt->len = len;
767 tgt->error = "Unknown error";
768
769 /*
770 * Does this target adjoin the previous one ?
771 */
772 if (!adjoin(t, tgt)) {
773 tgt->error = "Gap in table";
774 r = -EINVAL;
775 goto bad;
776 }
777
778 r = dm_split_args(&argc, &argv, params);
779 if (r) {
780 tgt->error = "couldn't split parameters (insufficient memory)";
781 goto bad;
782 }
783
784 r = tgt->type->ctr(tgt, argc, argv);
785 kfree(argv);
786 if (r)
787 goto bad;
788
789 t->highs[t->num_targets++] = tgt->begin + tgt->len - 1;
790
791 if (!tgt->num_discard_bios && tgt->discards_supported)
792 DMWARN("%s: %s: ignoring discards_supported because num_discard_bios is zero.",
793 dm_device_name(t->md), type);
794
795 return 0;
796
797 bad:
798 DMERR("%s: %s: %s", dm_device_name(t->md), type, tgt->error);
799 dm_put_target_type(tgt->type);
800 return r;
801}
802
803/*
804 * Target argument parsing helpers.
805 */
806static int validate_next_arg(struct dm_arg *arg, struct dm_arg_set *arg_set,
807 unsigned *value, char **error, unsigned grouped)
808{
809 const char *arg_str = dm_shift_arg(arg_set);
810 char dummy;
811
812 if (!arg_str ||
813 (sscanf(arg_str, "%u%c", value, &dummy) != 1) ||
814 (*value < arg->min) ||
815 (*value > arg->max) ||
816 (grouped && arg_set->argc < *value)) {
817 *error = arg->error;
818 return -EINVAL;
819 }
820
821 return 0;
822}
823
824int dm_read_arg(struct dm_arg *arg, struct dm_arg_set *arg_set,
825 unsigned *value, char **error)
826{
827 return validate_next_arg(arg, arg_set, value, error, 0);
828}
829EXPORT_SYMBOL(dm_read_arg);
830
831int dm_read_arg_group(struct dm_arg *arg, struct dm_arg_set *arg_set,
832 unsigned *value, char **error)
833{
834 return validate_next_arg(arg, arg_set, value, error, 1);
835}
836EXPORT_SYMBOL(dm_read_arg_group);
837
838const char *dm_shift_arg(struct dm_arg_set *as)
839{
840 char *r;
841
842 if (as->argc) {
843 as->argc--;
844 r = *as->argv;
845 as->argv++;
846 return r;
847 }
848
849 return NULL;
850}
851EXPORT_SYMBOL(dm_shift_arg);
852
853void dm_consume_args(struct dm_arg_set *as, unsigned num_args)
854{
855 BUG_ON(as->argc < num_args);
856 as->argc -= num_args;
857 as->argv += num_args;
858}
859EXPORT_SYMBOL(dm_consume_args);
860
861static int dm_table_set_type(struct dm_table *t)
862{
863 unsigned i;
864 unsigned bio_based = 0, request_based = 0, hybrid = 0;
865 struct dm_target *tgt;
866 struct dm_dev_internal *dd;
867 struct list_head *devices;
868 unsigned live_md_type;
869
870 for (i = 0; i < t->num_targets; i++) {
871 tgt = t->targets + i;
872 if (dm_target_hybrid(tgt))
873 hybrid = 1;
874 else if (dm_target_request_based(tgt))
875 request_based = 1;
876 else
877 bio_based = 1;
878
879 if (bio_based && request_based) {
880 DMWARN("Inconsistent table: different target types"
881 " can't be mixed up");
882 return -EINVAL;
883 }
884 }
885
886 if (hybrid && !bio_based && !request_based) {
887 /*
888 * The targets can work either way.
889 * Determine the type from the live device.
890 * Default to bio-based if device is new.
891 */
892 live_md_type = dm_get_md_type(t->md);
893 if (live_md_type == DM_TYPE_REQUEST_BASED)
894 request_based = 1;
895 else
896 bio_based = 1;
897 }
898
899 if (bio_based) {
900 /* We must use this table as bio-based */
901 t->type = DM_TYPE_BIO_BASED;
902 return 0;
903 }
904
905 BUG_ON(!request_based); /* No targets in this table */
906
907 /* Non-request-stackable devices can't be used for request-based dm */
908 devices = dm_table_get_devices(t);
909 list_for_each_entry(dd, devices, list) {
910 if (!blk_queue_stackable(bdev_get_queue(dd->dm_dev.bdev))) {
911 DMWARN("table load rejected: including"
912 " non-request-stackable devices");
913 return -EINVAL;
914 }
915 }
916
917 /*
918 * Request-based dm supports only tables that have a single target now.
919 * To support multiple targets, request splitting support is needed,
920 * and that needs lots of changes in the block-layer.
921 * (e.g. request completion process for partial completion.)
922 */
923 if (t->num_targets > 1) {
924 DMWARN("Request-based dm doesn't support multiple targets yet");
925 return -EINVAL;
926 }
927
928 t->type = DM_TYPE_REQUEST_BASED;
929
930 return 0;
931}
932
933unsigned dm_table_get_type(struct dm_table *t)
934{
935 return t->type;
936}
937
938struct target_type *dm_table_get_immutable_target_type(struct dm_table *t)
939{
940 return t->immutable_target_type;
941}
942
943bool dm_table_request_based(struct dm_table *t)
944{
945 return dm_table_get_type(t) == DM_TYPE_REQUEST_BASED;
946}
947
948static int dm_table_alloc_md_mempools(struct dm_table *t)
949{
950 unsigned type = dm_table_get_type(t);
951 unsigned per_bio_data_size = 0;
952 struct dm_target *tgt;
953 unsigned i;
954
955 if (unlikely(type == DM_TYPE_NONE)) {
956 DMWARN("no table type is set, can't allocate mempools");
957 return -EINVAL;
958 }
959
960 if (type == DM_TYPE_BIO_BASED)
961 for (i = 0; i < t->num_targets; i++) {
962 tgt = t->targets + i;
963 per_bio_data_size = max(per_bio_data_size, tgt->per_bio_data_size);
964 }
965
966 t->mempools = dm_alloc_md_mempools(type, t->integrity_supported, per_bio_data_size);
967 if (!t->mempools)
968 return -ENOMEM;
969
970 return 0;
971}
972
973void dm_table_free_md_mempools(struct dm_table *t)
974{
975 dm_free_md_mempools(t->mempools);
976 t->mempools = NULL;
977}
978
979struct dm_md_mempools *dm_table_get_md_mempools(struct dm_table *t)
980{
981 return t->mempools;
982}
983
984static int setup_indexes(struct dm_table *t)
985{
986 int i;
987 unsigned int total = 0;
988 sector_t *indexes;
989
990 /* allocate the space for *all* the indexes */
991 for (i = t->depth - 2; i >= 0; i--) {
992 t->counts[i] = dm_div_up(t->counts[i + 1], CHILDREN_PER_NODE);
993 total += t->counts[i];
994 }
995
996 indexes = (sector_t *) dm_vcalloc(total, (unsigned long) NODE_SIZE);
997 if (!indexes)
998 return -ENOMEM;
999
1000 /* set up internal nodes, bottom-up */
1001 for (i = t->depth - 2; i >= 0; i--) {
1002 t->index[i] = indexes;
1003 indexes += (KEYS_PER_NODE * t->counts[i]);
1004 setup_btree_index(i, t);
1005 }
1006
1007 return 0;
1008}
1009
1010/*
1011 * Builds the btree to index the map.
1012 */
1013static int dm_table_build_index(struct dm_table *t)
1014{
1015 int r = 0;
1016 unsigned int leaf_nodes;
1017
1018 /* how many indexes will the btree have ? */
1019 leaf_nodes = dm_div_up(t->num_targets, KEYS_PER_NODE);
1020 t->depth = 1 + int_log(leaf_nodes, CHILDREN_PER_NODE);
1021
1022 /* leaf layer has already been set up */
1023 t->counts[t->depth - 1] = leaf_nodes;
1024 t->index[t->depth - 1] = t->highs;
1025
1026 if (t->depth >= 2)
1027 r = setup_indexes(t);
1028
1029 return r;
1030}
1031
1032/*
1033 * Get a disk whose integrity profile reflects the table's profile.
1034 * If %match_all is true, all devices' profiles must match.
1035 * If %match_all is false, all devices must at least have an
1036 * allocated integrity profile; but uninitialized is ok.
1037 * Returns NULL if integrity support was inconsistent or unavailable.
1038 */
1039static struct gendisk * dm_table_get_integrity_disk(struct dm_table *t,
1040 bool match_all)
1041{
1042 struct list_head *devices = dm_table_get_devices(t);
1043 struct dm_dev_internal *dd = NULL;
1044 struct gendisk *prev_disk = NULL, *template_disk = NULL;
1045
1046 list_for_each_entry(dd, devices, list) {
1047 template_disk = dd->dm_dev.bdev->bd_disk;
1048 if (!blk_get_integrity(template_disk))
1049 goto no_integrity;
1050 if (!match_all && !blk_integrity_is_initialized(template_disk))
1051 continue; /* skip uninitialized profiles */
1052 else if (prev_disk &&
1053 blk_integrity_compare(prev_disk, template_disk) < 0)
1054 goto no_integrity;
1055 prev_disk = template_disk;
1056 }
1057
1058 return template_disk;
1059
1060no_integrity:
1061 if (prev_disk)
1062 DMWARN("%s: integrity not set: %s and %s profile mismatch",
1063 dm_device_name(t->md),
1064 prev_disk->disk_name,
1065 template_disk->disk_name);
1066 return NULL;
1067}
1068
1069/*
1070 * Register the mapped device for blk_integrity support if
1071 * the underlying devices have an integrity profile. But all devices
1072 * may not have matching profiles (checking all devices isn't reliable
1073 * during table load because this table may use other DM device(s) which
1074 * must be resumed before they will have an initialized integity profile).
1075 * Stacked DM devices force a 2 stage integrity profile validation:
1076 * 1 - during load, validate all initialized integrity profiles match
1077 * 2 - during resume, validate all integrity profiles match
1078 */
1079static int dm_table_prealloc_integrity(struct dm_table *t, struct mapped_device *md)
1080{
1081 struct gendisk *template_disk = NULL;
1082
1083 template_disk = dm_table_get_integrity_disk(t, false);
1084 if (!template_disk)
1085 return 0;
1086
1087 if (!blk_integrity_is_initialized(dm_disk(md))) {
1088 t->integrity_supported = 1;
1089 return blk_integrity_register(dm_disk(md), NULL);
1090 }
1091
1092 /*
1093 * If DM device already has an initalized integrity
1094 * profile the new profile should not conflict.
1095 */
1096 if (blk_integrity_is_initialized(template_disk) &&
1097 blk_integrity_compare(dm_disk(md), template_disk) < 0) {
1098 DMWARN("%s: conflict with existing integrity profile: "
1099 "%s profile mismatch",
1100 dm_device_name(t->md),
1101 template_disk->disk_name);
1102 return 1;
1103 }
1104
1105 /* Preserve existing initialized integrity profile */
1106 t->integrity_supported = 1;
1107 return 0;
1108}
1109
1110/*
1111 * Prepares the table for use by building the indices,
1112 * setting the type, and allocating mempools.
1113 */
1114int dm_table_complete(struct dm_table *t)
1115{
1116 int r;
1117
1118 r = dm_table_set_type(t);
1119 if (r) {
1120 DMERR("unable to set table type");
1121 return r;
1122 }
1123
1124 r = dm_table_build_index(t);
1125 if (r) {
1126 DMERR("unable to build btrees");
1127 return r;
1128 }
1129
1130 r = dm_table_prealloc_integrity(t, t->md);
1131 if (r) {
1132 DMERR("could not register integrity profile.");
1133 return r;
1134 }
1135
1136 r = dm_table_alloc_md_mempools(t);
1137 if (r)
1138 DMERR("unable to allocate mempools");
1139
1140 return r;
1141}
1142
1143static DEFINE_MUTEX(_event_lock);
1144void dm_table_event_callback(struct dm_table *t,
1145 void (*fn)(void *), void *context)
1146{
1147 mutex_lock(&_event_lock);
1148 t->event_fn = fn;
1149 t->event_context = context;
1150 mutex_unlock(&_event_lock);
1151}
1152
1153void dm_table_event(struct dm_table *t)
1154{
1155 /*
1156 * You can no longer call dm_table_event() from interrupt
1157 * context, use a bottom half instead.
1158 */
1159 BUG_ON(in_interrupt());
1160
1161 mutex_lock(&_event_lock);
1162 if (t->event_fn)
1163 t->event_fn(t->event_context);
1164 mutex_unlock(&_event_lock);
1165}
1166EXPORT_SYMBOL(dm_table_event);
1167
1168sector_t dm_table_get_size(struct dm_table *t)
1169{
1170 return t->num_targets ? (t->highs[t->num_targets - 1] + 1) : 0;
1171}
1172EXPORT_SYMBOL(dm_table_get_size);
1173
1174struct dm_target *dm_table_get_target(struct dm_table *t, unsigned int index)
1175{
1176 if (index >= t->num_targets)
1177 return NULL;
1178
1179 return t->targets + index;
1180}
1181
1182/*
1183 * Search the btree for the correct target.
1184 *
1185 * Caller should check returned pointer with dm_target_is_valid()
1186 * to trap I/O beyond end of device.
1187 */
1188struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector)
1189{
1190 unsigned int l, n = 0, k = 0;
1191 sector_t *node;
1192
1193 for (l = 0; l < t->depth; l++) {
1194 n = get_child(n, k);
1195 node = get_node(t, l, n);
1196
1197 for (k = 0; k < KEYS_PER_NODE; k++)
1198 if (node[k] >= sector)
1199 break;
1200 }
1201
1202 return &t->targets[(KEYS_PER_NODE * n) + k];
1203}
1204
1205static int count_device(struct dm_target *ti, struct dm_dev *dev,
1206 sector_t start, sector_t len, void *data)
1207{
1208 unsigned *num_devices = data;
1209
1210 (*num_devices)++;
1211
1212 return 0;
1213}
1214
1215/*
1216 * Check whether a table has no data devices attached using each
1217 * target's iterate_devices method.
1218 * Returns false if the result is unknown because a target doesn't
1219 * support iterate_devices.
1220 */
1221bool dm_table_has_no_data_devices(struct dm_table *table)
1222{
1223 struct dm_target *uninitialized_var(ti);
1224 unsigned i = 0, num_devices = 0;
1225
1226 while (i < dm_table_get_num_targets(table)) {
1227 ti = dm_table_get_target(table, i++);
1228
1229 if (!ti->type->iterate_devices)
1230 return false;
1231
1232 ti->type->iterate_devices(ti, count_device, &num_devices);
1233 if (num_devices)
1234 return false;
1235 }
1236
1237 return true;
1238}
1239
1240/*
1241 * Establish the new table's queue_limits and validate them.
1242 */
1243int dm_calculate_queue_limits(struct dm_table *table,
1244 struct queue_limits *limits)
1245{
1246 struct dm_target *uninitialized_var(ti);
1247 struct queue_limits ti_limits;
1248 unsigned i = 0;
1249
1250 blk_set_stacking_limits(limits);
1251
1252 while (i < dm_table_get_num_targets(table)) {
1253 blk_set_stacking_limits(&ti_limits);
1254
1255 ti = dm_table_get_target(table, i++);
1256
1257 if (!ti->type->iterate_devices)
1258 goto combine_limits;
1259
1260 /*
1261 * Combine queue limits of all the devices this target uses.
1262 */
1263 ti->type->iterate_devices(ti, dm_set_device_limits,
1264 &ti_limits);
1265
1266 /* Set I/O hints portion of queue limits */
1267 if (ti->type->io_hints)
1268 ti->type->io_hints(ti, &ti_limits);
1269
1270 /*
1271 * Check each device area is consistent with the target's
1272 * overall queue limits.
1273 */
1274 if (ti->type->iterate_devices(ti, device_area_is_invalid,
1275 &ti_limits))
1276 return -EINVAL;
1277
1278combine_limits:
1279 /*
1280 * Merge this target's queue limits into the overall limits
1281 * for the table.
1282 */
1283 if (blk_stack_limits(limits, &ti_limits, 0) < 0)
1284 DMWARN("%s: adding target device "
1285 "(start sect %llu len %llu) "
1286 "caused an alignment inconsistency",
1287 dm_device_name(table->md),
1288 (unsigned long long) ti->begin,
1289 (unsigned long long) ti->len);
1290 }
1291
1292 return validate_hardware_logical_block_alignment(table, limits);
1293}
1294
1295/*
1296 * Set the integrity profile for this device if all devices used have
1297 * matching profiles. We're quite deep in the resume path but still
1298 * don't know if all devices (particularly DM devices this device
1299 * may be stacked on) have matching profiles. Even if the profiles
1300 * don't match we have no way to fail (to resume) at this point.
1301 */
1302static void dm_table_set_integrity(struct dm_table *t)
1303{
1304 struct gendisk *template_disk = NULL;
1305
1306 if (!blk_get_integrity(dm_disk(t->md)))
1307 return;
1308
1309 template_disk = dm_table_get_integrity_disk(t, true);
1310 if (template_disk)
1311 blk_integrity_register(dm_disk(t->md),
1312 blk_get_integrity(template_disk));
1313 else if (blk_integrity_is_initialized(dm_disk(t->md)))
1314 DMWARN("%s: device no longer has a valid integrity profile",
1315 dm_device_name(t->md));
1316 else
1317 DMWARN("%s: unable to establish an integrity profile",
1318 dm_device_name(t->md));
1319}
1320
1321static int device_flush_capable(struct dm_target *ti, struct dm_dev *dev,
1322 sector_t start, sector_t len, void *data)
1323{
1324 unsigned flush = (*(unsigned *)data);
1325 struct request_queue *q = bdev_get_queue(dev->bdev);
1326
1327 return q && (q->flush_flags & flush);
1328}
1329
1330static bool dm_table_supports_flush(struct dm_table *t, unsigned flush)
1331{
1332 struct dm_target *ti;
1333 unsigned i = 0;
1334
1335 /*
1336 * Require at least one underlying device to support flushes.
1337 * t->devices includes internal dm devices such as mirror logs
1338 * so we need to use iterate_devices here, which targets
1339 * supporting flushes must provide.
1340 */
1341 while (i < dm_table_get_num_targets(t)) {
1342 ti = dm_table_get_target(t, i++);
1343
1344 if (!ti->num_flush_bios)
1345 continue;
1346
1347 if (ti->flush_supported)
1348 return 1;
1349
1350 if (ti->type->iterate_devices &&
1351 ti->type->iterate_devices(ti, device_flush_capable, &flush))
1352 return 1;
1353 }
1354
1355 return 0;
1356}
1357
1358static bool dm_table_discard_zeroes_data(struct dm_table *t)
1359{
1360 struct dm_target *ti;
1361 unsigned i = 0;
1362
1363 /* Ensure that all targets supports discard_zeroes_data. */
1364 while (i < dm_table_get_num_targets(t)) {
1365 ti = dm_table_get_target(t, i++);
1366
1367 if (ti->discard_zeroes_data_unsupported)
1368 return 0;
1369 }
1370
1371 return 1;
1372}
1373
1374static int device_is_nonrot(struct dm_target *ti, struct dm_dev *dev,
1375 sector_t start, sector_t len, void *data)
1376{
1377 struct request_queue *q = bdev_get_queue(dev->bdev);
1378
1379 return q && blk_queue_nonrot(q);
1380}
1381
1382static int device_is_not_random(struct dm_target *ti, struct dm_dev *dev,
1383 sector_t start, sector_t len, void *data)
1384{
1385 struct request_queue *q = bdev_get_queue(dev->bdev);
1386
1387 return q && !blk_queue_add_random(q);
1388}
1389
1390static bool dm_table_all_devices_attribute(struct dm_table *t,
1391 iterate_devices_callout_fn func)
1392{
1393 struct dm_target *ti;
1394 unsigned i = 0;
1395
1396 while (i < dm_table_get_num_targets(t)) {
1397 ti = dm_table_get_target(t, i++);
1398
1399 if (!ti->type->iterate_devices ||
1400 !ti->type->iterate_devices(ti, func, NULL))
1401 return 0;
1402 }
1403
1404 return 1;
1405}
1406
1407static int device_not_write_same_capable(struct dm_target *ti, struct dm_dev *dev,
1408 sector_t start, sector_t len, void *data)
1409{
1410 struct request_queue *q = bdev_get_queue(dev->bdev);
1411
1412 return q && !q->limits.max_write_same_sectors;
1413}
1414
1415static bool dm_table_supports_write_same(struct dm_table *t)
1416{
1417 struct dm_target *ti;
1418 unsigned i = 0;
1419
1420 while (i < dm_table_get_num_targets(t)) {
1421 ti = dm_table_get_target(t, i++);
1422
1423 if (!ti->num_write_same_bios)
1424 return false;
1425
1426 if (!ti->type->iterate_devices ||
1427 ti->type->iterate_devices(ti, device_not_write_same_capable, NULL))
1428 return false;
1429 }
1430
1431 return true;
1432}
1433
1434void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
1435 struct queue_limits *limits)
1436{
1437 unsigned flush = 0;
1438
1439 /*
1440 * Copy table's limits to the DM device's request_queue
1441 */
1442 q->limits = *limits;
1443
1444 if (!dm_table_supports_discards(t))
1445 queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, q);
1446 else
1447 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q);
1448
1449 if (dm_table_supports_flush(t, REQ_FLUSH)) {
1450 flush |= REQ_FLUSH;
1451 if (dm_table_supports_flush(t, REQ_FUA))
1452 flush |= REQ_FUA;
1453 }
1454 blk_queue_flush(q, flush);
1455
1456 if (!dm_table_discard_zeroes_data(t))
1457 q->limits.discard_zeroes_data = 0;
1458
1459 /* Ensure that all underlying devices are non-rotational. */
1460 if (dm_table_all_devices_attribute(t, device_is_nonrot))
1461 queue_flag_set_unlocked(QUEUE_FLAG_NONROT, q);
1462 else
1463 queue_flag_clear_unlocked(QUEUE_FLAG_NONROT, q);
1464
1465 if (!dm_table_supports_write_same(t))
1466 q->limits.max_write_same_sectors = 0;
1467
1468 dm_table_set_integrity(t);
1469
1470 /*
1471 * Determine whether or not this queue's I/O timings contribute
1472 * to the entropy pool, Only request-based targets use this.
1473 * Clear QUEUE_FLAG_ADD_RANDOM if any underlying device does not
1474 * have it set.
1475 */
1476 if (blk_queue_add_random(q) && dm_table_all_devices_attribute(t, device_is_not_random))
1477 queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, q);
1478
1479 /*
1480 * QUEUE_FLAG_STACKABLE must be set after all queue settings are
1481 * visible to other CPUs because, once the flag is set, incoming bios
1482 * are processed by request-based dm, which refers to the queue
1483 * settings.
1484 * Until the flag set, bios are passed to bio-based dm and queued to
1485 * md->deferred where queue settings are not needed yet.
1486 * Those bios are passed to request-based dm at the resume time.
1487 */
1488 smp_mb();
1489 if (dm_table_request_based(t))
1490 queue_flag_set_unlocked(QUEUE_FLAG_STACKABLE, q);
1491}
1492
1493unsigned int dm_table_get_num_targets(struct dm_table *t)
1494{
1495 return t->num_targets;
1496}
1497
1498struct list_head *dm_table_get_devices(struct dm_table *t)
1499{
1500 return &t->devices;
1501}
1502
1503fmode_t dm_table_get_mode(struct dm_table *t)
1504{
1505 return t->mode;
1506}
1507EXPORT_SYMBOL(dm_table_get_mode);
1508
1509static void suspend_targets(struct dm_table *t, unsigned postsuspend)
1510{
1511 int i = t->num_targets;
1512 struct dm_target *ti = t->targets;
1513
1514 while (i--) {
1515 if (postsuspend) {
1516 if (ti->type->postsuspend)
1517 ti->type->postsuspend(ti);
1518 } else if (ti->type->presuspend)
1519 ti->type->presuspend(ti);
1520
1521 ti++;
1522 }
1523}
1524
1525void dm_table_presuspend_targets(struct dm_table *t)
1526{
1527 if (!t)
1528 return;
1529
1530 suspend_targets(t, 0);
1531}
1532
1533void dm_table_postsuspend_targets(struct dm_table *t)
1534{
1535 if (!t)
1536 return;
1537
1538 suspend_targets(t, 1);
1539}
1540
1541int dm_table_resume_targets(struct dm_table *t)
1542{
1543 int i, r = 0;
1544
1545 for (i = 0; i < t->num_targets; i++) {
1546 struct dm_target *ti = t->targets + i;
1547
1548 if (!ti->type->preresume)
1549 continue;
1550
1551 r = ti->type->preresume(ti);
1552 if (r) {
1553 DMERR("%s: %s: preresume failed, error = %d",
1554 dm_device_name(t->md), ti->type->name, r);
1555 return r;
1556 }
1557 }
1558
1559 for (i = 0; i < t->num_targets; i++) {
1560 struct dm_target *ti = t->targets + i;
1561
1562 if (ti->type->resume)
1563 ti->type->resume(ti);
1564 }
1565
1566 return 0;
1567}
1568
1569void dm_table_add_target_callbacks(struct dm_table *t, struct dm_target_callbacks *cb)
1570{
1571 list_add(&cb->list, &t->target_callbacks);
1572}
1573EXPORT_SYMBOL_GPL(dm_table_add_target_callbacks);
1574
1575int dm_table_any_congested(struct dm_table *t, int bdi_bits)
1576{
1577 struct dm_dev_internal *dd;
1578 struct list_head *devices = dm_table_get_devices(t);
1579 struct dm_target_callbacks *cb;
1580 int r = 0;
1581
1582 list_for_each_entry(dd, devices, list) {
1583 struct request_queue *q = bdev_get_queue(dd->dm_dev.bdev);
1584 char b[BDEVNAME_SIZE];
1585
1586 if (likely(q))
1587 r |= bdi_congested(&q->backing_dev_info, bdi_bits);
1588 else
1589 DMWARN_LIMIT("%s: any_congested: nonexistent device %s",
1590 dm_device_name(t->md),
1591 bdevname(dd->dm_dev.bdev, b));
1592 }
1593
1594 list_for_each_entry(cb, &t->target_callbacks, list)
1595 if (cb->congested_fn)
1596 r |= cb->congested_fn(cb, bdi_bits);
1597
1598 return r;
1599}
1600
1601int dm_table_any_busy_target(struct dm_table *t)
1602{
1603 unsigned i;
1604 struct dm_target *ti;
1605
1606 for (i = 0; i < t->num_targets; i++) {
1607 ti = t->targets + i;
1608 if (ti->type->busy && ti->type->busy(ti))
1609 return 1;
1610 }
1611
1612 return 0;
1613}
1614
1615struct mapped_device *dm_table_get_md(struct dm_table *t)
1616{
1617 return t->md;
1618}
1619EXPORT_SYMBOL(dm_table_get_md);
1620
1621void dm_table_run_md_queue_async(struct dm_table *t)
1622{
1623 struct mapped_device *md;
1624 struct request_queue *queue;
1625 unsigned long flags;
1626
1627 if (!dm_table_request_based(t))
1628 return;
1629
1630 md = dm_table_get_md(t);
1631 queue = dm_get_md_queue(md);
1632 if (queue) {
1633 spin_lock_irqsave(queue->queue_lock, flags);
1634 blk_run_queue_async(queue);
1635 spin_unlock_irqrestore(queue->queue_lock, flags);
1636 }
1637}
1638EXPORT_SYMBOL(dm_table_run_md_queue_async);
1639
1640static int device_discard_capable(struct dm_target *ti, struct dm_dev *dev,
1641 sector_t start, sector_t len, void *data)
1642{
1643 struct request_queue *q = bdev_get_queue(dev->bdev);
1644
1645 return q && blk_queue_discard(q);
1646}
1647
1648bool dm_table_supports_discards(struct dm_table *t)
1649{
1650 struct dm_target *ti;
1651 unsigned i = 0;
1652
1653 /*
1654 * Unless any target used by the table set discards_supported,
1655 * require at least one underlying device to support discards.
1656 * t->devices includes internal dm devices such as mirror logs
1657 * so we need to use iterate_devices here, which targets
1658 * supporting discard selectively must provide.
1659 */
1660 while (i < dm_table_get_num_targets(t)) {
1661 ti = dm_table_get_target(t, i++);
1662
1663 if (!ti->num_discard_bios)
1664 continue;
1665
1666 if (ti->discards_supported)
1667 return 1;
1668
1669 if (ti->type->iterate_devices &&
1670 ti->type->iterate_devices(ti, device_discard_capable, NULL))
1671 return 1;
1672 }
1673
1674 return 0;
1675}