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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2001 Sistina Software (UK) Limited.
4 * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
5 *
6 * This file is released under the GPL.
7 */
8
9#include "dm-core.h"
10#include "dm-rq.h"
11
12#include <linux/module.h>
13#include <linux/vmalloc.h>
14#include <linux/blkdev.h>
15#include <linux/blk-integrity.h>
16#include <linux/namei.h>
17#include <linux/ctype.h>
18#include <linux/string.h>
19#include <linux/slab.h>
20#include <linux/interrupt.h>
21#include <linux/mutex.h>
22#include <linux/delay.h>
23#include <linux/atomic.h>
24#include <linux/blk-mq.h>
25#include <linux/mount.h>
26#include <linux/dax.h>
27
28#define DM_MSG_PREFIX "table"
29
30#define NODE_SIZE L1_CACHE_BYTES
31#define KEYS_PER_NODE (NODE_SIZE / sizeof(sector_t))
32#define CHILDREN_PER_NODE (KEYS_PER_NODE + 1)
33
34/*
35 * Similar to ceiling(log_size(n))
36 */
37static unsigned int int_log(unsigned int n, unsigned int base)
38{
39 int result = 0;
40
41 while (n > 1) {
42 n = dm_div_up(n, base);
43 result++;
44 }
45
46 return result;
47}
48
49/*
50 * Calculate the index of the child node of the n'th node k'th key.
51 */
52static inline unsigned int get_child(unsigned int n, unsigned int k)
53{
54 return (n * CHILDREN_PER_NODE) + k;
55}
56
57/*
58 * Return the n'th node of level l from table t.
59 */
60static inline sector_t *get_node(struct dm_table *t,
61 unsigned int l, unsigned int n)
62{
63 return t->index[l] + (n * KEYS_PER_NODE);
64}
65
66/*
67 * Return the highest key that you could lookup from the n'th
68 * node on level l of the btree.
69 */
70static sector_t high(struct dm_table *t, unsigned int l, unsigned int n)
71{
72 for (; l < t->depth - 1; l++)
73 n = get_child(n, CHILDREN_PER_NODE - 1);
74
75 if (n >= t->counts[l])
76 return (sector_t) -1;
77
78 return get_node(t, l, n)[KEYS_PER_NODE - 1];
79}
80
81/*
82 * Fills in a level of the btree based on the highs of the level
83 * below it.
84 */
85static int setup_btree_index(unsigned int l, struct dm_table *t)
86{
87 unsigned int n, k;
88 sector_t *node;
89
90 for (n = 0U; n < t->counts[l]; n++) {
91 node = get_node(t, l, n);
92
93 for (k = 0U; k < KEYS_PER_NODE; k++)
94 node[k] = high(t, l + 1, get_child(n, k));
95 }
96
97 return 0;
98}
99
100/*
101 * highs, and targets are managed as dynamic arrays during a
102 * table load.
103 */
104static int alloc_targets(struct dm_table *t, unsigned int num)
105{
106 sector_t *n_highs;
107 struct dm_target *n_targets;
108
109 /*
110 * Allocate both the target array and offset array at once.
111 */
112 n_highs = kvcalloc(num, sizeof(struct dm_target) + sizeof(sector_t),
113 GFP_KERNEL);
114 if (!n_highs)
115 return -ENOMEM;
116
117 n_targets = (struct dm_target *) (n_highs + num);
118
119 memset(n_highs, -1, sizeof(*n_highs) * num);
120 kvfree(t->highs);
121
122 t->num_allocated = num;
123 t->highs = n_highs;
124 t->targets = n_targets;
125
126 return 0;
127}
128
129int dm_table_create(struct dm_table **result, blk_mode_t mode,
130 unsigned int num_targets, struct mapped_device *md)
131{
132 struct dm_table *t;
133
134 if (num_targets > DM_MAX_TARGETS)
135 return -EOVERFLOW;
136
137 t = kzalloc(sizeof(*t), GFP_KERNEL);
138
139 if (!t)
140 return -ENOMEM;
141
142 INIT_LIST_HEAD(&t->devices);
143 init_rwsem(&t->devices_lock);
144
145 if (!num_targets)
146 num_targets = KEYS_PER_NODE;
147
148 num_targets = dm_round_up(num_targets, KEYS_PER_NODE);
149
150 if (!num_targets) {
151 kfree(t);
152 return -EOVERFLOW;
153 }
154
155 if (alloc_targets(t, num_targets)) {
156 kfree(t);
157 return -ENOMEM;
158 }
159
160 t->type = DM_TYPE_NONE;
161 t->mode = mode;
162 t->md = md;
163 *result = t;
164 return 0;
165}
166
167static void free_devices(struct list_head *devices, struct mapped_device *md)
168{
169 struct list_head *tmp, *next;
170
171 list_for_each_safe(tmp, next, devices) {
172 struct dm_dev_internal *dd =
173 list_entry(tmp, struct dm_dev_internal, list);
174 DMWARN("%s: dm_table_destroy: dm_put_device call missing for %s",
175 dm_device_name(md), dd->dm_dev->name);
176 dm_put_table_device(md, dd->dm_dev);
177 kfree(dd);
178 }
179}
180
181static void dm_table_destroy_crypto_profile(struct dm_table *t);
182
183void dm_table_destroy(struct dm_table *t)
184{
185 if (!t)
186 return;
187
188 /* free the indexes */
189 if (t->depth >= 2)
190 kvfree(t->index[t->depth - 2]);
191
192 /* free the targets */
193 for (unsigned int i = 0; i < t->num_targets; i++) {
194 struct dm_target *ti = dm_table_get_target(t, i);
195
196 if (ti->type->dtr)
197 ti->type->dtr(ti);
198
199 dm_put_target_type(ti->type);
200 }
201
202 kvfree(t->highs);
203
204 /* free the device list */
205 free_devices(&t->devices, t->md);
206
207 dm_free_md_mempools(t->mempools);
208
209 dm_table_destroy_crypto_profile(t);
210
211 kfree(t);
212}
213
214/*
215 * See if we've already got a device in the list.
216 */
217static struct dm_dev_internal *find_device(struct list_head *l, dev_t dev)
218{
219 struct dm_dev_internal *dd;
220
221 list_for_each_entry(dd, l, list)
222 if (dd->dm_dev->bdev->bd_dev == dev)
223 return dd;
224
225 return NULL;
226}
227
228/*
229 * If possible, this checks an area of a destination device is invalid.
230 */
231static int device_area_is_invalid(struct dm_target *ti, struct dm_dev *dev,
232 sector_t start, sector_t len, void *data)
233{
234 struct queue_limits *limits = data;
235 struct block_device *bdev = dev->bdev;
236 sector_t dev_size = bdev_nr_sectors(bdev);
237 unsigned short logical_block_size_sectors =
238 limits->logical_block_size >> SECTOR_SHIFT;
239
240 if (!dev_size)
241 return 0;
242
243 if ((start >= dev_size) || (start + len > dev_size)) {
244 DMERR("%s: %pg too small for target: start=%llu, len=%llu, dev_size=%llu",
245 dm_device_name(ti->table->md), bdev,
246 (unsigned long long)start,
247 (unsigned long long)len,
248 (unsigned long long)dev_size);
249 return 1;
250 }
251
252 /*
253 * If the target is mapped to zoned block device(s), check
254 * that the zones are not partially mapped.
255 */
256 if (bdev_is_zoned(bdev)) {
257 unsigned int zone_sectors = bdev_zone_sectors(bdev);
258
259 if (start & (zone_sectors - 1)) {
260 DMERR("%s: start=%llu not aligned to h/w zone size %u of %pg",
261 dm_device_name(ti->table->md),
262 (unsigned long long)start,
263 zone_sectors, bdev);
264 return 1;
265 }
266
267 /*
268 * Note: The last zone of a zoned block device may be smaller
269 * than other zones. So for a target mapping the end of a
270 * zoned block device with such a zone, len would not be zone
271 * aligned. We do not allow such last smaller zone to be part
272 * of the mapping here to ensure that mappings with multiple
273 * devices do not end up with a smaller zone in the middle of
274 * the sector range.
275 */
276 if (len & (zone_sectors - 1)) {
277 DMERR("%s: len=%llu not aligned to h/w zone size %u of %pg",
278 dm_device_name(ti->table->md),
279 (unsigned long long)len,
280 zone_sectors, bdev);
281 return 1;
282 }
283 }
284
285 if (logical_block_size_sectors <= 1)
286 return 0;
287
288 if (start & (logical_block_size_sectors - 1)) {
289 DMERR("%s: start=%llu not aligned to h/w logical block size %u of %pg",
290 dm_device_name(ti->table->md),
291 (unsigned long long)start,
292 limits->logical_block_size, bdev);
293 return 1;
294 }
295
296 if (len & (logical_block_size_sectors - 1)) {
297 DMERR("%s: len=%llu not aligned to h/w logical block size %u of %pg",
298 dm_device_name(ti->table->md),
299 (unsigned long long)len,
300 limits->logical_block_size, bdev);
301 return 1;
302 }
303
304 return 0;
305}
306
307/*
308 * This upgrades the mode on an already open dm_dev, being
309 * careful to leave things as they were if we fail to reopen the
310 * device and not to touch the existing bdev field in case
311 * it is accessed concurrently.
312 */
313static int upgrade_mode(struct dm_dev_internal *dd, blk_mode_t new_mode,
314 struct mapped_device *md)
315{
316 int r;
317 struct dm_dev *old_dev, *new_dev;
318
319 old_dev = dd->dm_dev;
320
321 r = dm_get_table_device(md, dd->dm_dev->bdev->bd_dev,
322 dd->dm_dev->mode | new_mode, &new_dev);
323 if (r)
324 return r;
325
326 dd->dm_dev = new_dev;
327 dm_put_table_device(md, old_dev);
328
329 return 0;
330}
331
332/*
333 * Add a device to the list, or just increment the usage count if
334 * it's already present.
335 *
336 * Note: the __ref annotation is because this function can call the __init
337 * marked early_lookup_bdev when called during early boot code from dm-init.c.
338 */
339int __ref dm_get_device(struct dm_target *ti, const char *path, blk_mode_t mode,
340 struct dm_dev **result)
341{
342 int r;
343 dev_t dev;
344 unsigned int major, minor;
345 char dummy;
346 struct dm_dev_internal *dd;
347 struct dm_table *t = ti->table;
348
349 BUG_ON(!t);
350
351 if (sscanf(path, "%u:%u%c", &major, &minor, &dummy) == 2) {
352 /* Extract the major/minor numbers */
353 dev = MKDEV(major, minor);
354 if (MAJOR(dev) != major || MINOR(dev) != minor)
355 return -EOVERFLOW;
356 } else {
357 r = lookup_bdev(path, &dev);
358#ifndef MODULE
359 if (r && system_state < SYSTEM_RUNNING)
360 r = early_lookup_bdev(path, &dev);
361#endif
362 if (r)
363 return r;
364 }
365 if (dev == disk_devt(t->md->disk))
366 return -EINVAL;
367
368 down_write(&t->devices_lock);
369
370 dd = find_device(&t->devices, dev);
371 if (!dd) {
372 dd = kmalloc(sizeof(*dd), GFP_KERNEL);
373 if (!dd) {
374 r = -ENOMEM;
375 goto unlock_ret_r;
376 }
377
378 r = dm_get_table_device(t->md, dev, mode, &dd->dm_dev);
379 if (r) {
380 kfree(dd);
381 goto unlock_ret_r;
382 }
383
384 refcount_set(&dd->count, 1);
385 list_add(&dd->list, &t->devices);
386 goto out;
387
388 } else if (dd->dm_dev->mode != (mode | dd->dm_dev->mode)) {
389 r = upgrade_mode(dd, mode, t->md);
390 if (r)
391 goto unlock_ret_r;
392 }
393 refcount_inc(&dd->count);
394out:
395 up_write(&t->devices_lock);
396 *result = dd->dm_dev;
397 return 0;
398
399unlock_ret_r:
400 up_write(&t->devices_lock);
401 return r;
402}
403EXPORT_SYMBOL(dm_get_device);
404
405static int dm_set_device_limits(struct dm_target *ti, struct dm_dev *dev,
406 sector_t start, sector_t len, void *data)
407{
408 struct queue_limits *limits = data;
409 struct block_device *bdev = dev->bdev;
410 struct request_queue *q = bdev_get_queue(bdev);
411
412 if (unlikely(!q)) {
413 DMWARN("%s: Cannot set limits for nonexistent device %pg",
414 dm_device_name(ti->table->md), bdev);
415 return 0;
416 }
417
418 if (blk_stack_limits(limits, &q->limits,
419 get_start_sect(bdev) + start) < 0)
420 DMWARN("%s: adding target device %pg caused an alignment inconsistency: "
421 "physical_block_size=%u, logical_block_size=%u, "
422 "alignment_offset=%u, start=%llu",
423 dm_device_name(ti->table->md), bdev,
424 q->limits.physical_block_size,
425 q->limits.logical_block_size,
426 q->limits.alignment_offset,
427 (unsigned long long) start << SECTOR_SHIFT);
428 return 0;
429}
430
431/*
432 * Decrement a device's use count and remove it if necessary.
433 */
434void dm_put_device(struct dm_target *ti, struct dm_dev *d)
435{
436 int found = 0;
437 struct dm_table *t = ti->table;
438 struct list_head *devices = &t->devices;
439 struct dm_dev_internal *dd;
440
441 down_write(&t->devices_lock);
442
443 list_for_each_entry(dd, devices, list) {
444 if (dd->dm_dev == d) {
445 found = 1;
446 break;
447 }
448 }
449 if (!found) {
450 DMERR("%s: device %s not in table devices list",
451 dm_device_name(t->md), d->name);
452 goto unlock_ret;
453 }
454 if (refcount_dec_and_test(&dd->count)) {
455 dm_put_table_device(t->md, d);
456 list_del(&dd->list);
457 kfree(dd);
458 }
459
460unlock_ret:
461 up_write(&t->devices_lock);
462}
463EXPORT_SYMBOL(dm_put_device);
464
465/*
466 * Checks to see if the target joins onto the end of the table.
467 */
468static int adjoin(struct dm_table *t, struct dm_target *ti)
469{
470 struct dm_target *prev;
471
472 if (!t->num_targets)
473 return !ti->begin;
474
475 prev = &t->targets[t->num_targets - 1];
476 return (ti->begin == (prev->begin + prev->len));
477}
478
479/*
480 * Used to dynamically allocate the arg array.
481 *
482 * We do first allocation with GFP_NOIO because dm-mpath and dm-thin must
483 * process messages even if some device is suspended. These messages have a
484 * small fixed number of arguments.
485 *
486 * On the other hand, dm-switch needs to process bulk data using messages and
487 * excessive use of GFP_NOIO could cause trouble.
488 */
489static char **realloc_argv(unsigned int *size, char **old_argv)
490{
491 char **argv;
492 unsigned int new_size;
493 gfp_t gfp;
494
495 if (*size) {
496 new_size = *size * 2;
497 gfp = GFP_KERNEL;
498 } else {
499 new_size = 8;
500 gfp = GFP_NOIO;
501 }
502 argv = kmalloc_array(new_size, sizeof(*argv), gfp);
503 if (argv && old_argv) {
504 memcpy(argv, old_argv, *size * sizeof(*argv));
505 *size = new_size;
506 }
507
508 kfree(old_argv);
509 return argv;
510}
511
512/*
513 * Destructively splits up the argument list to pass to ctr.
514 */
515int dm_split_args(int *argc, char ***argvp, char *input)
516{
517 char *start, *end = input, *out, **argv = NULL;
518 unsigned int array_size = 0;
519
520 *argc = 0;
521
522 if (!input) {
523 *argvp = NULL;
524 return 0;
525 }
526
527 argv = realloc_argv(&array_size, argv);
528 if (!argv)
529 return -ENOMEM;
530
531 while (1) {
532 /* Skip whitespace */
533 start = skip_spaces(end);
534
535 if (!*start)
536 break; /* success, we hit the end */
537
538 /* 'out' is used to remove any back-quotes */
539 end = out = start;
540 while (*end) {
541 /* Everything apart from '\0' can be quoted */
542 if (*end == '\\' && *(end + 1)) {
543 *out++ = *(end + 1);
544 end += 2;
545 continue;
546 }
547
548 if (isspace(*end))
549 break; /* end of token */
550
551 *out++ = *end++;
552 }
553
554 /* have we already filled the array ? */
555 if ((*argc + 1) > array_size) {
556 argv = realloc_argv(&array_size, argv);
557 if (!argv)
558 return -ENOMEM;
559 }
560
561 /* we know this is whitespace */
562 if (*end)
563 end++;
564
565 /* terminate the string and put it in the array */
566 *out = '\0';
567 argv[*argc] = start;
568 (*argc)++;
569 }
570
571 *argvp = argv;
572 return 0;
573}
574
575/*
576 * Impose necessary and sufficient conditions on a devices's table such
577 * that any incoming bio which respects its logical_block_size can be
578 * processed successfully. If it falls across the boundary between
579 * two or more targets, the size of each piece it gets split into must
580 * be compatible with the logical_block_size of the target processing it.
581 */
582static int validate_hardware_logical_block_alignment(struct dm_table *t,
583 struct queue_limits *limits)
584{
585 /*
586 * This function uses arithmetic modulo the logical_block_size
587 * (in units of 512-byte sectors).
588 */
589 unsigned short device_logical_block_size_sects =
590 limits->logical_block_size >> SECTOR_SHIFT;
591
592 /*
593 * Offset of the start of the next table entry, mod logical_block_size.
594 */
595 unsigned short next_target_start = 0;
596
597 /*
598 * Given an aligned bio that extends beyond the end of a
599 * target, how many sectors must the next target handle?
600 */
601 unsigned short remaining = 0;
602
603 struct dm_target *ti;
604 struct queue_limits ti_limits;
605 unsigned int i;
606
607 /*
608 * Check each entry in the table in turn.
609 */
610 for (i = 0; i < t->num_targets; i++) {
611 ti = dm_table_get_target(t, i);
612
613 blk_set_stacking_limits(&ti_limits);
614
615 /* combine all target devices' limits */
616 if (ti->type->iterate_devices)
617 ti->type->iterate_devices(ti, dm_set_device_limits,
618 &ti_limits);
619
620 /*
621 * If the remaining sectors fall entirely within this
622 * table entry are they compatible with its logical_block_size?
623 */
624 if (remaining < ti->len &&
625 remaining & ((ti_limits.logical_block_size >>
626 SECTOR_SHIFT) - 1))
627 break; /* Error */
628
629 next_target_start =
630 (unsigned short) ((next_target_start + ti->len) &
631 (device_logical_block_size_sects - 1));
632 remaining = next_target_start ?
633 device_logical_block_size_sects - next_target_start : 0;
634 }
635
636 if (remaining) {
637 DMERR("%s: table line %u (start sect %llu len %llu) "
638 "not aligned to h/w logical block size %u",
639 dm_device_name(t->md), i,
640 (unsigned long long) ti->begin,
641 (unsigned long long) ti->len,
642 limits->logical_block_size);
643 return -EINVAL;
644 }
645
646 return 0;
647}
648
649int dm_table_add_target(struct dm_table *t, const char *type,
650 sector_t start, sector_t len, char *params)
651{
652 int r = -EINVAL, argc;
653 char **argv;
654 struct dm_target *ti;
655
656 if (t->singleton) {
657 DMERR("%s: target type %s must appear alone in table",
658 dm_device_name(t->md), t->targets->type->name);
659 return -EINVAL;
660 }
661
662 BUG_ON(t->num_targets >= t->num_allocated);
663
664 ti = t->targets + t->num_targets;
665 memset(ti, 0, sizeof(*ti));
666
667 if (!len) {
668 DMERR("%s: zero-length target", dm_device_name(t->md));
669 return -EINVAL;
670 }
671
672 ti->type = dm_get_target_type(type);
673 if (!ti->type) {
674 DMERR("%s: %s: unknown target type", dm_device_name(t->md), type);
675 return -EINVAL;
676 }
677
678 if (dm_target_needs_singleton(ti->type)) {
679 if (t->num_targets) {
680 ti->error = "singleton target type must appear alone in table";
681 goto bad;
682 }
683 t->singleton = true;
684 }
685
686 if (dm_target_always_writeable(ti->type) &&
687 !(t->mode & BLK_OPEN_WRITE)) {
688 ti->error = "target type may not be included in a read-only table";
689 goto bad;
690 }
691
692 if (t->immutable_target_type) {
693 if (t->immutable_target_type != ti->type) {
694 ti->error = "immutable target type cannot be mixed with other target types";
695 goto bad;
696 }
697 } else if (dm_target_is_immutable(ti->type)) {
698 if (t->num_targets) {
699 ti->error = "immutable target type cannot be mixed with other target types";
700 goto bad;
701 }
702 t->immutable_target_type = ti->type;
703 }
704
705 if (dm_target_has_integrity(ti->type))
706 t->integrity_added = 1;
707
708 ti->table = t;
709 ti->begin = start;
710 ti->len = len;
711 ti->error = "Unknown error";
712
713 /*
714 * Does this target adjoin the previous one ?
715 */
716 if (!adjoin(t, ti)) {
717 ti->error = "Gap in table";
718 goto bad;
719 }
720
721 r = dm_split_args(&argc, &argv, params);
722 if (r) {
723 ti->error = "couldn't split parameters";
724 goto bad;
725 }
726
727 r = ti->type->ctr(ti, argc, argv);
728 kfree(argv);
729 if (r)
730 goto bad;
731
732 t->highs[t->num_targets++] = ti->begin + ti->len - 1;
733
734 if (!ti->num_discard_bios && ti->discards_supported)
735 DMWARN("%s: %s: ignoring discards_supported because num_discard_bios is zero.",
736 dm_device_name(t->md), type);
737
738 if (ti->limit_swap_bios && !static_key_enabled(&swap_bios_enabled.key))
739 static_branch_enable(&swap_bios_enabled);
740
741 return 0;
742
743 bad:
744 DMERR("%s: %s: %s (%pe)", dm_device_name(t->md), type, ti->error, ERR_PTR(r));
745 dm_put_target_type(ti->type);
746 return r;
747}
748
749/*
750 * Target argument parsing helpers.
751 */
752static int validate_next_arg(const struct dm_arg *arg, struct dm_arg_set *arg_set,
753 unsigned int *value, char **error, unsigned int grouped)
754{
755 const char *arg_str = dm_shift_arg(arg_set);
756 char dummy;
757
758 if (!arg_str ||
759 (sscanf(arg_str, "%u%c", value, &dummy) != 1) ||
760 (*value < arg->min) ||
761 (*value > arg->max) ||
762 (grouped && arg_set->argc < *value)) {
763 *error = arg->error;
764 return -EINVAL;
765 }
766
767 return 0;
768}
769
770int dm_read_arg(const struct dm_arg *arg, struct dm_arg_set *arg_set,
771 unsigned int *value, char **error)
772{
773 return validate_next_arg(arg, arg_set, value, error, 0);
774}
775EXPORT_SYMBOL(dm_read_arg);
776
777int dm_read_arg_group(const struct dm_arg *arg, struct dm_arg_set *arg_set,
778 unsigned int *value, char **error)
779{
780 return validate_next_arg(arg, arg_set, value, error, 1);
781}
782EXPORT_SYMBOL(dm_read_arg_group);
783
784const char *dm_shift_arg(struct dm_arg_set *as)
785{
786 char *r;
787
788 if (as->argc) {
789 as->argc--;
790 r = *as->argv;
791 as->argv++;
792 return r;
793 }
794
795 return NULL;
796}
797EXPORT_SYMBOL(dm_shift_arg);
798
799void dm_consume_args(struct dm_arg_set *as, unsigned int num_args)
800{
801 BUG_ON(as->argc < num_args);
802 as->argc -= num_args;
803 as->argv += num_args;
804}
805EXPORT_SYMBOL(dm_consume_args);
806
807static bool __table_type_bio_based(enum dm_queue_mode table_type)
808{
809 return (table_type == DM_TYPE_BIO_BASED ||
810 table_type == DM_TYPE_DAX_BIO_BASED);
811}
812
813static bool __table_type_request_based(enum dm_queue_mode table_type)
814{
815 return table_type == DM_TYPE_REQUEST_BASED;
816}
817
818void dm_table_set_type(struct dm_table *t, enum dm_queue_mode type)
819{
820 t->type = type;
821}
822EXPORT_SYMBOL_GPL(dm_table_set_type);
823
824/* validate the dax capability of the target device span */
825static int device_not_dax_capable(struct dm_target *ti, struct dm_dev *dev,
826 sector_t start, sector_t len, void *data)
827{
828 if (dev->dax_dev)
829 return false;
830
831 DMDEBUG("%pg: error: dax unsupported by block device", dev->bdev);
832 return true;
833}
834
835/* Check devices support synchronous DAX */
836static int device_not_dax_synchronous_capable(struct dm_target *ti, struct dm_dev *dev,
837 sector_t start, sector_t len, void *data)
838{
839 return !dev->dax_dev || !dax_synchronous(dev->dax_dev);
840}
841
842static bool dm_table_supports_dax(struct dm_table *t,
843 iterate_devices_callout_fn iterate_fn)
844{
845 /* Ensure that all targets support DAX. */
846 for (unsigned int i = 0; i < t->num_targets; i++) {
847 struct dm_target *ti = dm_table_get_target(t, i);
848
849 if (!ti->type->direct_access)
850 return false;
851
852 if (dm_target_is_wildcard(ti->type) ||
853 !ti->type->iterate_devices ||
854 ti->type->iterate_devices(ti, iterate_fn, NULL))
855 return false;
856 }
857
858 return true;
859}
860
861static int device_is_rq_stackable(struct dm_target *ti, struct dm_dev *dev,
862 sector_t start, sector_t len, void *data)
863{
864 struct block_device *bdev = dev->bdev;
865 struct request_queue *q = bdev_get_queue(bdev);
866
867 /* request-based cannot stack on partitions! */
868 if (bdev_is_partition(bdev))
869 return false;
870
871 return queue_is_mq(q);
872}
873
874static int dm_table_determine_type(struct dm_table *t)
875{
876 unsigned int bio_based = 0, request_based = 0, hybrid = 0;
877 struct dm_target *ti;
878 struct list_head *devices = dm_table_get_devices(t);
879 enum dm_queue_mode live_md_type = dm_get_md_type(t->md);
880
881 if (t->type != DM_TYPE_NONE) {
882 /* target already set the table's type */
883 if (t->type == DM_TYPE_BIO_BASED) {
884 /* possibly upgrade to a variant of bio-based */
885 goto verify_bio_based;
886 }
887 BUG_ON(t->type == DM_TYPE_DAX_BIO_BASED);
888 goto verify_rq_based;
889 }
890
891 for (unsigned int i = 0; i < t->num_targets; i++) {
892 ti = dm_table_get_target(t, i);
893 if (dm_target_hybrid(ti))
894 hybrid = 1;
895 else if (dm_target_request_based(ti))
896 request_based = 1;
897 else
898 bio_based = 1;
899
900 if (bio_based && request_based) {
901 DMERR("Inconsistent table: different target types can't be mixed up");
902 return -EINVAL;
903 }
904 }
905
906 if (hybrid && !bio_based && !request_based) {
907 /*
908 * The targets can work either way.
909 * Determine the type from the live device.
910 * Default to bio-based if device is new.
911 */
912 if (__table_type_request_based(live_md_type))
913 request_based = 1;
914 else
915 bio_based = 1;
916 }
917
918 if (bio_based) {
919verify_bio_based:
920 /* We must use this table as bio-based */
921 t->type = DM_TYPE_BIO_BASED;
922 if (dm_table_supports_dax(t, device_not_dax_capable) ||
923 (list_empty(devices) && live_md_type == DM_TYPE_DAX_BIO_BASED)) {
924 t->type = DM_TYPE_DAX_BIO_BASED;
925 }
926 return 0;
927 }
928
929 BUG_ON(!request_based); /* No targets in this table */
930
931 t->type = DM_TYPE_REQUEST_BASED;
932
933verify_rq_based:
934 /*
935 * Request-based dm supports only tables that have a single target now.
936 * To support multiple targets, request splitting support is needed,
937 * and that needs lots of changes in the block-layer.
938 * (e.g. request completion process for partial completion.)
939 */
940 if (t->num_targets > 1) {
941 DMERR("request-based DM doesn't support multiple targets");
942 return -EINVAL;
943 }
944
945 if (list_empty(devices)) {
946 int srcu_idx;
947 struct dm_table *live_table = dm_get_live_table(t->md, &srcu_idx);
948
949 /* inherit live table's type */
950 if (live_table)
951 t->type = live_table->type;
952 dm_put_live_table(t->md, srcu_idx);
953 return 0;
954 }
955
956 ti = dm_table_get_immutable_target(t);
957 if (!ti) {
958 DMERR("table load rejected: immutable target is required");
959 return -EINVAL;
960 } else if (ti->max_io_len) {
961 DMERR("table load rejected: immutable target that splits IO is not supported");
962 return -EINVAL;
963 }
964
965 /* Non-request-stackable devices can't be used for request-based dm */
966 if (!ti->type->iterate_devices ||
967 !ti->type->iterate_devices(ti, device_is_rq_stackable, NULL)) {
968 DMERR("table load rejected: including non-request-stackable devices");
969 return -EINVAL;
970 }
971
972 return 0;
973}
974
975enum dm_queue_mode dm_table_get_type(struct dm_table *t)
976{
977 return t->type;
978}
979
980struct target_type *dm_table_get_immutable_target_type(struct dm_table *t)
981{
982 return t->immutable_target_type;
983}
984
985struct dm_target *dm_table_get_immutable_target(struct dm_table *t)
986{
987 /* Immutable target is implicitly a singleton */
988 if (t->num_targets > 1 ||
989 !dm_target_is_immutable(t->targets[0].type))
990 return NULL;
991
992 return t->targets;
993}
994
995struct dm_target *dm_table_get_wildcard_target(struct dm_table *t)
996{
997 for (unsigned int i = 0; i < t->num_targets; i++) {
998 struct dm_target *ti = dm_table_get_target(t, i);
999
1000 if (dm_target_is_wildcard(ti->type))
1001 return ti;
1002 }
1003
1004 return NULL;
1005}
1006
1007bool dm_table_bio_based(struct dm_table *t)
1008{
1009 return __table_type_bio_based(dm_table_get_type(t));
1010}
1011
1012bool dm_table_request_based(struct dm_table *t)
1013{
1014 return __table_type_request_based(dm_table_get_type(t));
1015}
1016
1017static bool dm_table_supports_poll(struct dm_table *t);
1018
1019static int dm_table_alloc_md_mempools(struct dm_table *t, struct mapped_device *md)
1020{
1021 enum dm_queue_mode type = dm_table_get_type(t);
1022 unsigned int per_io_data_size = 0, front_pad, io_front_pad;
1023 unsigned int min_pool_size = 0, pool_size;
1024 struct dm_md_mempools *pools;
1025
1026 if (unlikely(type == DM_TYPE_NONE)) {
1027 DMERR("no table type is set, can't allocate mempools");
1028 return -EINVAL;
1029 }
1030
1031 pools = kzalloc_node(sizeof(*pools), GFP_KERNEL, md->numa_node_id);
1032 if (!pools)
1033 return -ENOMEM;
1034
1035 if (type == DM_TYPE_REQUEST_BASED) {
1036 pool_size = dm_get_reserved_rq_based_ios();
1037 front_pad = offsetof(struct dm_rq_clone_bio_info, clone);
1038 goto init_bs;
1039 }
1040
1041 for (unsigned int i = 0; i < t->num_targets; i++) {
1042 struct dm_target *ti = dm_table_get_target(t, i);
1043
1044 per_io_data_size = max(per_io_data_size, ti->per_io_data_size);
1045 min_pool_size = max(min_pool_size, ti->num_flush_bios);
1046 }
1047 pool_size = max(dm_get_reserved_bio_based_ios(), min_pool_size);
1048 front_pad = roundup(per_io_data_size,
1049 __alignof__(struct dm_target_io)) + DM_TARGET_IO_BIO_OFFSET;
1050
1051 io_front_pad = roundup(per_io_data_size,
1052 __alignof__(struct dm_io)) + DM_IO_BIO_OFFSET;
1053 if (bioset_init(&pools->io_bs, pool_size, io_front_pad,
1054 dm_table_supports_poll(t) ? BIOSET_PERCPU_CACHE : 0))
1055 goto out_free_pools;
1056 if (t->integrity_supported &&
1057 bioset_integrity_create(&pools->io_bs, pool_size))
1058 goto out_free_pools;
1059init_bs:
1060 if (bioset_init(&pools->bs, pool_size, front_pad, 0))
1061 goto out_free_pools;
1062 if (t->integrity_supported &&
1063 bioset_integrity_create(&pools->bs, pool_size))
1064 goto out_free_pools;
1065
1066 t->mempools = pools;
1067 return 0;
1068
1069out_free_pools:
1070 dm_free_md_mempools(pools);
1071 return -ENOMEM;
1072}
1073
1074static int setup_indexes(struct dm_table *t)
1075{
1076 int i;
1077 unsigned int total = 0;
1078 sector_t *indexes;
1079
1080 /* allocate the space for *all* the indexes */
1081 for (i = t->depth - 2; i >= 0; i--) {
1082 t->counts[i] = dm_div_up(t->counts[i + 1], CHILDREN_PER_NODE);
1083 total += t->counts[i];
1084 }
1085
1086 indexes = kvcalloc(total, NODE_SIZE, GFP_KERNEL);
1087 if (!indexes)
1088 return -ENOMEM;
1089
1090 /* set up internal nodes, bottom-up */
1091 for (i = t->depth - 2; i >= 0; i--) {
1092 t->index[i] = indexes;
1093 indexes += (KEYS_PER_NODE * t->counts[i]);
1094 setup_btree_index(i, t);
1095 }
1096
1097 return 0;
1098}
1099
1100/*
1101 * Builds the btree to index the map.
1102 */
1103static int dm_table_build_index(struct dm_table *t)
1104{
1105 int r = 0;
1106 unsigned int leaf_nodes;
1107
1108 /* how many indexes will the btree have ? */
1109 leaf_nodes = dm_div_up(t->num_targets, KEYS_PER_NODE);
1110 t->depth = 1 + int_log(leaf_nodes, CHILDREN_PER_NODE);
1111
1112 /* leaf layer has already been set up */
1113 t->counts[t->depth - 1] = leaf_nodes;
1114 t->index[t->depth - 1] = t->highs;
1115
1116 if (t->depth >= 2)
1117 r = setup_indexes(t);
1118
1119 return r;
1120}
1121
1122static bool integrity_profile_exists(struct gendisk *disk)
1123{
1124 return !!blk_get_integrity(disk);
1125}
1126
1127/*
1128 * Get a disk whose integrity profile reflects the table's profile.
1129 * Returns NULL if integrity support was inconsistent or unavailable.
1130 */
1131static struct gendisk *dm_table_get_integrity_disk(struct dm_table *t)
1132{
1133 struct list_head *devices = dm_table_get_devices(t);
1134 struct dm_dev_internal *dd = NULL;
1135 struct gendisk *prev_disk = NULL, *template_disk = NULL;
1136
1137 for (unsigned int i = 0; i < t->num_targets; i++) {
1138 struct dm_target *ti = dm_table_get_target(t, i);
1139
1140 if (!dm_target_passes_integrity(ti->type))
1141 goto no_integrity;
1142 }
1143
1144 list_for_each_entry(dd, devices, list) {
1145 template_disk = dd->dm_dev->bdev->bd_disk;
1146 if (!integrity_profile_exists(template_disk))
1147 goto no_integrity;
1148 else if (prev_disk &&
1149 blk_integrity_compare(prev_disk, template_disk) < 0)
1150 goto no_integrity;
1151 prev_disk = template_disk;
1152 }
1153
1154 return template_disk;
1155
1156no_integrity:
1157 if (prev_disk)
1158 DMWARN("%s: integrity not set: %s and %s profile mismatch",
1159 dm_device_name(t->md),
1160 prev_disk->disk_name,
1161 template_disk->disk_name);
1162 return NULL;
1163}
1164
1165/*
1166 * Register the mapped device for blk_integrity support if the
1167 * underlying devices have an integrity profile. But all devices may
1168 * not have matching profiles (checking all devices isn't reliable
1169 * during table load because this table may use other DM device(s) which
1170 * must be resumed before they will have an initialized integity
1171 * profile). Consequently, stacked DM devices force a 2 stage integrity
1172 * profile validation: First pass during table load, final pass during
1173 * resume.
1174 */
1175static int dm_table_register_integrity(struct dm_table *t)
1176{
1177 struct mapped_device *md = t->md;
1178 struct gendisk *template_disk = NULL;
1179
1180 /* If target handles integrity itself do not register it here. */
1181 if (t->integrity_added)
1182 return 0;
1183
1184 template_disk = dm_table_get_integrity_disk(t);
1185 if (!template_disk)
1186 return 0;
1187
1188 if (!integrity_profile_exists(dm_disk(md))) {
1189 t->integrity_supported = true;
1190 /*
1191 * Register integrity profile during table load; we can do
1192 * this because the final profile must match during resume.
1193 */
1194 blk_integrity_register(dm_disk(md),
1195 blk_get_integrity(template_disk));
1196 return 0;
1197 }
1198
1199 /*
1200 * If DM device already has an initialized integrity
1201 * profile the new profile should not conflict.
1202 */
1203 if (blk_integrity_compare(dm_disk(md), template_disk) < 0) {
1204 DMERR("%s: conflict with existing integrity profile: %s profile mismatch",
1205 dm_device_name(t->md),
1206 template_disk->disk_name);
1207 return 1;
1208 }
1209
1210 /* Preserve existing integrity profile */
1211 t->integrity_supported = true;
1212 return 0;
1213}
1214
1215#ifdef CONFIG_BLK_INLINE_ENCRYPTION
1216
1217struct dm_crypto_profile {
1218 struct blk_crypto_profile profile;
1219 struct mapped_device *md;
1220};
1221
1222static int dm_keyslot_evict_callback(struct dm_target *ti, struct dm_dev *dev,
1223 sector_t start, sector_t len, void *data)
1224{
1225 const struct blk_crypto_key *key = data;
1226
1227 blk_crypto_evict_key(dev->bdev, key);
1228 return 0;
1229}
1230
1231/*
1232 * When an inline encryption key is evicted from a device-mapper device, evict
1233 * it from all the underlying devices.
1234 */
1235static int dm_keyslot_evict(struct blk_crypto_profile *profile,
1236 const struct blk_crypto_key *key, unsigned int slot)
1237{
1238 struct mapped_device *md =
1239 container_of(profile, struct dm_crypto_profile, profile)->md;
1240 struct dm_table *t;
1241 int srcu_idx;
1242
1243 t = dm_get_live_table(md, &srcu_idx);
1244 if (!t)
1245 return 0;
1246
1247 for (unsigned int i = 0; i < t->num_targets; i++) {
1248 struct dm_target *ti = dm_table_get_target(t, i);
1249
1250 if (!ti->type->iterate_devices)
1251 continue;
1252 ti->type->iterate_devices(ti, dm_keyslot_evict_callback,
1253 (void *)key);
1254 }
1255
1256 dm_put_live_table(md, srcu_idx);
1257 return 0;
1258}
1259
1260static int
1261device_intersect_crypto_capabilities(struct dm_target *ti, struct dm_dev *dev,
1262 sector_t start, sector_t len, void *data)
1263{
1264 struct blk_crypto_profile *parent = data;
1265 struct blk_crypto_profile *child =
1266 bdev_get_queue(dev->bdev)->crypto_profile;
1267
1268 blk_crypto_intersect_capabilities(parent, child);
1269 return 0;
1270}
1271
1272void dm_destroy_crypto_profile(struct blk_crypto_profile *profile)
1273{
1274 struct dm_crypto_profile *dmcp = container_of(profile,
1275 struct dm_crypto_profile,
1276 profile);
1277
1278 if (!profile)
1279 return;
1280
1281 blk_crypto_profile_destroy(profile);
1282 kfree(dmcp);
1283}
1284
1285static void dm_table_destroy_crypto_profile(struct dm_table *t)
1286{
1287 dm_destroy_crypto_profile(t->crypto_profile);
1288 t->crypto_profile = NULL;
1289}
1290
1291/*
1292 * Constructs and initializes t->crypto_profile with a crypto profile that
1293 * represents the common set of crypto capabilities of the devices described by
1294 * the dm_table. However, if the constructed crypto profile doesn't support all
1295 * crypto capabilities that are supported by the current mapped_device, it
1296 * returns an error instead, since we don't support removing crypto capabilities
1297 * on table changes. Finally, if the constructed crypto profile is "empty" (has
1298 * no crypto capabilities at all), it just sets t->crypto_profile to NULL.
1299 */
1300static int dm_table_construct_crypto_profile(struct dm_table *t)
1301{
1302 struct dm_crypto_profile *dmcp;
1303 struct blk_crypto_profile *profile;
1304 unsigned int i;
1305 bool empty_profile = true;
1306
1307 dmcp = kmalloc(sizeof(*dmcp), GFP_KERNEL);
1308 if (!dmcp)
1309 return -ENOMEM;
1310 dmcp->md = t->md;
1311
1312 profile = &dmcp->profile;
1313 blk_crypto_profile_init(profile, 0);
1314 profile->ll_ops.keyslot_evict = dm_keyslot_evict;
1315 profile->max_dun_bytes_supported = UINT_MAX;
1316 memset(profile->modes_supported, 0xFF,
1317 sizeof(profile->modes_supported));
1318
1319 for (i = 0; i < t->num_targets; i++) {
1320 struct dm_target *ti = dm_table_get_target(t, i);
1321
1322 if (!dm_target_passes_crypto(ti->type)) {
1323 blk_crypto_intersect_capabilities(profile, NULL);
1324 break;
1325 }
1326 if (!ti->type->iterate_devices)
1327 continue;
1328 ti->type->iterate_devices(ti,
1329 device_intersect_crypto_capabilities,
1330 profile);
1331 }
1332
1333 if (t->md->queue &&
1334 !blk_crypto_has_capabilities(profile,
1335 t->md->queue->crypto_profile)) {
1336 DMERR("Inline encryption capabilities of new DM table were more restrictive than the old table's. This is not supported!");
1337 dm_destroy_crypto_profile(profile);
1338 return -EINVAL;
1339 }
1340
1341 /*
1342 * If the new profile doesn't actually support any crypto capabilities,
1343 * we may as well represent it with a NULL profile.
1344 */
1345 for (i = 0; i < ARRAY_SIZE(profile->modes_supported); i++) {
1346 if (profile->modes_supported[i]) {
1347 empty_profile = false;
1348 break;
1349 }
1350 }
1351
1352 if (empty_profile) {
1353 dm_destroy_crypto_profile(profile);
1354 profile = NULL;
1355 }
1356
1357 /*
1358 * t->crypto_profile is only set temporarily while the table is being
1359 * set up, and it gets set to NULL after the profile has been
1360 * transferred to the request_queue.
1361 */
1362 t->crypto_profile = profile;
1363
1364 return 0;
1365}
1366
1367static void dm_update_crypto_profile(struct request_queue *q,
1368 struct dm_table *t)
1369{
1370 if (!t->crypto_profile)
1371 return;
1372
1373 /* Make the crypto profile less restrictive. */
1374 if (!q->crypto_profile) {
1375 blk_crypto_register(t->crypto_profile, q);
1376 } else {
1377 blk_crypto_update_capabilities(q->crypto_profile,
1378 t->crypto_profile);
1379 dm_destroy_crypto_profile(t->crypto_profile);
1380 }
1381 t->crypto_profile = NULL;
1382}
1383
1384#else /* CONFIG_BLK_INLINE_ENCRYPTION */
1385
1386static int dm_table_construct_crypto_profile(struct dm_table *t)
1387{
1388 return 0;
1389}
1390
1391void dm_destroy_crypto_profile(struct blk_crypto_profile *profile)
1392{
1393}
1394
1395static void dm_table_destroy_crypto_profile(struct dm_table *t)
1396{
1397}
1398
1399static void dm_update_crypto_profile(struct request_queue *q,
1400 struct dm_table *t)
1401{
1402}
1403
1404#endif /* !CONFIG_BLK_INLINE_ENCRYPTION */
1405
1406/*
1407 * Prepares the table for use by building the indices,
1408 * setting the type, and allocating mempools.
1409 */
1410int dm_table_complete(struct dm_table *t)
1411{
1412 int r;
1413
1414 r = dm_table_determine_type(t);
1415 if (r) {
1416 DMERR("unable to determine table type");
1417 return r;
1418 }
1419
1420 r = dm_table_build_index(t);
1421 if (r) {
1422 DMERR("unable to build btrees");
1423 return r;
1424 }
1425
1426 r = dm_table_register_integrity(t);
1427 if (r) {
1428 DMERR("could not register integrity profile.");
1429 return r;
1430 }
1431
1432 r = dm_table_construct_crypto_profile(t);
1433 if (r) {
1434 DMERR("could not construct crypto profile.");
1435 return r;
1436 }
1437
1438 r = dm_table_alloc_md_mempools(t, t->md);
1439 if (r)
1440 DMERR("unable to allocate mempools");
1441
1442 return r;
1443}
1444
1445static DEFINE_MUTEX(_event_lock);
1446void dm_table_event_callback(struct dm_table *t,
1447 void (*fn)(void *), void *context)
1448{
1449 mutex_lock(&_event_lock);
1450 t->event_fn = fn;
1451 t->event_context = context;
1452 mutex_unlock(&_event_lock);
1453}
1454
1455void dm_table_event(struct dm_table *t)
1456{
1457 mutex_lock(&_event_lock);
1458 if (t->event_fn)
1459 t->event_fn(t->event_context);
1460 mutex_unlock(&_event_lock);
1461}
1462EXPORT_SYMBOL(dm_table_event);
1463
1464inline sector_t dm_table_get_size(struct dm_table *t)
1465{
1466 return t->num_targets ? (t->highs[t->num_targets - 1] + 1) : 0;
1467}
1468EXPORT_SYMBOL(dm_table_get_size);
1469
1470/*
1471 * Search the btree for the correct target.
1472 *
1473 * Caller should check returned pointer for NULL
1474 * to trap I/O beyond end of device.
1475 */
1476struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector)
1477{
1478 unsigned int l, n = 0, k = 0;
1479 sector_t *node;
1480
1481 if (unlikely(sector >= dm_table_get_size(t)))
1482 return NULL;
1483
1484 for (l = 0; l < t->depth; l++) {
1485 n = get_child(n, k);
1486 node = get_node(t, l, n);
1487
1488 for (k = 0; k < KEYS_PER_NODE; k++)
1489 if (node[k] >= sector)
1490 break;
1491 }
1492
1493 return &t->targets[(KEYS_PER_NODE * n) + k];
1494}
1495
1496static int device_not_poll_capable(struct dm_target *ti, struct dm_dev *dev,
1497 sector_t start, sector_t len, void *data)
1498{
1499 struct request_queue *q = bdev_get_queue(dev->bdev);
1500
1501 return !test_bit(QUEUE_FLAG_POLL, &q->queue_flags);
1502}
1503
1504/*
1505 * type->iterate_devices() should be called when the sanity check needs to
1506 * iterate and check all underlying data devices. iterate_devices() will
1507 * iterate all underlying data devices until it encounters a non-zero return
1508 * code, returned by whether the input iterate_devices_callout_fn, or
1509 * iterate_devices() itself internally.
1510 *
1511 * For some target type (e.g. dm-stripe), one call of iterate_devices() may
1512 * iterate multiple underlying devices internally, in which case a non-zero
1513 * return code returned by iterate_devices_callout_fn will stop the iteration
1514 * in advance.
1515 *
1516 * Cases requiring _any_ underlying device supporting some kind of attribute,
1517 * should use the iteration structure like dm_table_any_dev_attr(), or call
1518 * it directly. @func should handle semantics of positive examples, e.g.
1519 * capable of something.
1520 *
1521 * Cases requiring _all_ underlying devices supporting some kind of attribute,
1522 * should use the iteration structure like dm_table_supports_nowait() or
1523 * dm_table_supports_discards(). Or introduce dm_table_all_devs_attr() that
1524 * uses an @anti_func that handle semantics of counter examples, e.g. not
1525 * capable of something. So: return !dm_table_any_dev_attr(t, anti_func, data);
1526 */
1527static bool dm_table_any_dev_attr(struct dm_table *t,
1528 iterate_devices_callout_fn func, void *data)
1529{
1530 for (unsigned int i = 0; i < t->num_targets; i++) {
1531 struct dm_target *ti = dm_table_get_target(t, i);
1532
1533 if (ti->type->iterate_devices &&
1534 ti->type->iterate_devices(ti, func, data))
1535 return true;
1536 }
1537
1538 return false;
1539}
1540
1541static int count_device(struct dm_target *ti, struct dm_dev *dev,
1542 sector_t start, sector_t len, void *data)
1543{
1544 unsigned int *num_devices = data;
1545
1546 (*num_devices)++;
1547
1548 return 0;
1549}
1550
1551static bool dm_table_supports_poll(struct dm_table *t)
1552{
1553 for (unsigned int i = 0; i < t->num_targets; i++) {
1554 struct dm_target *ti = dm_table_get_target(t, i);
1555
1556 if (!ti->type->iterate_devices ||
1557 ti->type->iterate_devices(ti, device_not_poll_capable, NULL))
1558 return false;
1559 }
1560
1561 return true;
1562}
1563
1564/*
1565 * Check whether a table has no data devices attached using each
1566 * target's iterate_devices method.
1567 * Returns false if the result is unknown because a target doesn't
1568 * support iterate_devices.
1569 */
1570bool dm_table_has_no_data_devices(struct dm_table *t)
1571{
1572 for (unsigned int i = 0; i < t->num_targets; i++) {
1573 struct dm_target *ti = dm_table_get_target(t, i);
1574 unsigned int num_devices = 0;
1575
1576 if (!ti->type->iterate_devices)
1577 return false;
1578
1579 ti->type->iterate_devices(ti, count_device, &num_devices);
1580 if (num_devices)
1581 return false;
1582 }
1583
1584 return true;
1585}
1586
1587static int device_not_zoned(struct dm_target *ti, struct dm_dev *dev,
1588 sector_t start, sector_t len, void *data)
1589{
1590 bool *zoned = data;
1591
1592 return bdev_is_zoned(dev->bdev) != *zoned;
1593}
1594
1595static int device_is_zoned_model(struct dm_target *ti, struct dm_dev *dev,
1596 sector_t start, sector_t len, void *data)
1597{
1598 return bdev_is_zoned(dev->bdev);
1599}
1600
1601/*
1602 * Check the device zoned model based on the target feature flag. If the target
1603 * has the DM_TARGET_ZONED_HM feature flag set, host-managed zoned devices are
1604 * also accepted but all devices must have the same zoned model. If the target
1605 * has the DM_TARGET_MIXED_ZONED_MODEL feature set, the devices can have any
1606 * zoned model with all zoned devices having the same zone size.
1607 */
1608static bool dm_table_supports_zoned(struct dm_table *t, bool zoned)
1609{
1610 for (unsigned int i = 0; i < t->num_targets; i++) {
1611 struct dm_target *ti = dm_table_get_target(t, i);
1612
1613 /*
1614 * For the wildcard target (dm-error), if we do not have a
1615 * backing device, we must always return false. If we have a
1616 * backing device, the result must depend on checking zoned
1617 * model, like for any other target. So for this, check directly
1618 * if the target backing device is zoned as we get "false" when
1619 * dm-error was set without a backing device.
1620 */
1621 if (dm_target_is_wildcard(ti->type) &&
1622 !ti->type->iterate_devices(ti, device_is_zoned_model, NULL))
1623 return false;
1624
1625 if (dm_target_supports_zoned_hm(ti->type)) {
1626 if (!ti->type->iterate_devices ||
1627 ti->type->iterate_devices(ti, device_not_zoned,
1628 &zoned))
1629 return false;
1630 } else if (!dm_target_supports_mixed_zoned_model(ti->type)) {
1631 if (zoned)
1632 return false;
1633 }
1634 }
1635
1636 return true;
1637}
1638
1639static int device_not_matches_zone_sectors(struct dm_target *ti, struct dm_dev *dev,
1640 sector_t start, sector_t len, void *data)
1641{
1642 unsigned int *zone_sectors = data;
1643
1644 if (!bdev_is_zoned(dev->bdev))
1645 return 0;
1646 return bdev_zone_sectors(dev->bdev) != *zone_sectors;
1647}
1648
1649/*
1650 * Check consistency of zoned model and zone sectors across all targets. For
1651 * zone sectors, if the destination device is a zoned block device, it shall
1652 * have the specified zone_sectors.
1653 */
1654static int validate_hardware_zoned(struct dm_table *t, bool zoned,
1655 unsigned int zone_sectors)
1656{
1657 if (!zoned)
1658 return 0;
1659
1660 if (!dm_table_supports_zoned(t, zoned)) {
1661 DMERR("%s: zoned model is not consistent across all devices",
1662 dm_device_name(t->md));
1663 return -EINVAL;
1664 }
1665
1666 /* Check zone size validity and compatibility */
1667 if (!zone_sectors || !is_power_of_2(zone_sectors))
1668 return -EINVAL;
1669
1670 if (dm_table_any_dev_attr(t, device_not_matches_zone_sectors, &zone_sectors)) {
1671 DMERR("%s: zone sectors is not consistent across all zoned devices",
1672 dm_device_name(t->md));
1673 return -EINVAL;
1674 }
1675
1676 return 0;
1677}
1678
1679/*
1680 * Establish the new table's queue_limits and validate them.
1681 */
1682int dm_calculate_queue_limits(struct dm_table *t,
1683 struct queue_limits *limits)
1684{
1685 struct queue_limits ti_limits;
1686 unsigned int zone_sectors = 0;
1687 bool zoned = false;
1688
1689 blk_set_stacking_limits(limits);
1690
1691 for (unsigned int i = 0; i < t->num_targets; i++) {
1692 struct dm_target *ti = dm_table_get_target(t, i);
1693
1694 blk_set_stacking_limits(&ti_limits);
1695
1696 if (!ti->type->iterate_devices) {
1697 /* Set I/O hints portion of queue limits */
1698 if (ti->type->io_hints)
1699 ti->type->io_hints(ti, &ti_limits);
1700 goto combine_limits;
1701 }
1702
1703 /*
1704 * Combine queue limits of all the devices this target uses.
1705 */
1706 ti->type->iterate_devices(ti, dm_set_device_limits,
1707 &ti_limits);
1708
1709 if (!zoned && ti_limits.zoned) {
1710 /*
1711 * After stacking all limits, validate all devices
1712 * in table support this zoned model and zone sectors.
1713 */
1714 zoned = ti_limits.zoned;
1715 zone_sectors = ti_limits.chunk_sectors;
1716 }
1717
1718 /* Set I/O hints portion of queue limits */
1719 if (ti->type->io_hints)
1720 ti->type->io_hints(ti, &ti_limits);
1721
1722 /*
1723 * Check each device area is consistent with the target's
1724 * overall queue limits.
1725 */
1726 if (ti->type->iterate_devices(ti, device_area_is_invalid,
1727 &ti_limits))
1728 return -EINVAL;
1729
1730combine_limits:
1731 /*
1732 * Merge this target's queue limits into the overall limits
1733 * for the table.
1734 */
1735 if (blk_stack_limits(limits, &ti_limits, 0) < 0)
1736 DMWARN("%s: adding target device (start sect %llu len %llu) "
1737 "caused an alignment inconsistency",
1738 dm_device_name(t->md),
1739 (unsigned long long) ti->begin,
1740 (unsigned long long) ti->len);
1741 }
1742
1743 /*
1744 * Verify that the zoned model and zone sectors, as determined before
1745 * any .io_hints override, are the same across all devices in the table.
1746 * - this is especially relevant if .io_hints is emulating a disk-managed
1747 * zoned model on host-managed zoned block devices.
1748 * BUT...
1749 */
1750 if (limits->zoned) {
1751 /*
1752 * ...IF the above limits stacking determined a zoned model
1753 * validate that all of the table's devices conform to it.
1754 */
1755 zoned = limits->zoned;
1756 zone_sectors = limits->chunk_sectors;
1757 }
1758 if (validate_hardware_zoned(t, zoned, zone_sectors))
1759 return -EINVAL;
1760
1761 return validate_hardware_logical_block_alignment(t, limits);
1762}
1763
1764/*
1765 * Verify that all devices have an integrity profile that matches the
1766 * DM device's registered integrity profile. If the profiles don't
1767 * match then unregister the DM device's integrity profile.
1768 */
1769static void dm_table_verify_integrity(struct dm_table *t)
1770{
1771 struct gendisk *template_disk = NULL;
1772
1773 if (t->integrity_added)
1774 return;
1775
1776 if (t->integrity_supported) {
1777 /*
1778 * Verify that the original integrity profile
1779 * matches all the devices in this table.
1780 */
1781 template_disk = dm_table_get_integrity_disk(t);
1782 if (template_disk &&
1783 blk_integrity_compare(dm_disk(t->md), template_disk) >= 0)
1784 return;
1785 }
1786
1787 if (integrity_profile_exists(dm_disk(t->md))) {
1788 DMWARN("%s: unable to establish an integrity profile",
1789 dm_device_name(t->md));
1790 blk_integrity_unregister(dm_disk(t->md));
1791 }
1792}
1793
1794static int device_flush_capable(struct dm_target *ti, struct dm_dev *dev,
1795 sector_t start, sector_t len, void *data)
1796{
1797 unsigned long flush = (unsigned long) data;
1798 struct request_queue *q = bdev_get_queue(dev->bdev);
1799
1800 return (q->queue_flags & flush);
1801}
1802
1803static bool dm_table_supports_flush(struct dm_table *t, unsigned long flush)
1804{
1805 /*
1806 * Require at least one underlying device to support flushes.
1807 * t->devices includes internal dm devices such as mirror logs
1808 * so we need to use iterate_devices here, which targets
1809 * supporting flushes must provide.
1810 */
1811 for (unsigned int i = 0; i < t->num_targets; i++) {
1812 struct dm_target *ti = dm_table_get_target(t, i);
1813
1814 if (!ti->num_flush_bios)
1815 continue;
1816
1817 if (ti->flush_supported)
1818 return true;
1819
1820 if (ti->type->iterate_devices &&
1821 ti->type->iterate_devices(ti, device_flush_capable, (void *) flush))
1822 return true;
1823 }
1824
1825 return false;
1826}
1827
1828static int device_dax_write_cache_enabled(struct dm_target *ti,
1829 struct dm_dev *dev, sector_t start,
1830 sector_t len, void *data)
1831{
1832 struct dax_device *dax_dev = dev->dax_dev;
1833
1834 if (!dax_dev)
1835 return false;
1836
1837 if (dax_write_cache_enabled(dax_dev))
1838 return true;
1839 return false;
1840}
1841
1842static int device_is_rotational(struct dm_target *ti, struct dm_dev *dev,
1843 sector_t start, sector_t len, void *data)
1844{
1845 return !bdev_nonrot(dev->bdev);
1846}
1847
1848static int device_is_not_random(struct dm_target *ti, struct dm_dev *dev,
1849 sector_t start, sector_t len, void *data)
1850{
1851 struct request_queue *q = bdev_get_queue(dev->bdev);
1852
1853 return !blk_queue_add_random(q);
1854}
1855
1856static int device_not_write_zeroes_capable(struct dm_target *ti, struct dm_dev *dev,
1857 sector_t start, sector_t len, void *data)
1858{
1859 struct request_queue *q = bdev_get_queue(dev->bdev);
1860
1861 return !q->limits.max_write_zeroes_sectors;
1862}
1863
1864static bool dm_table_supports_write_zeroes(struct dm_table *t)
1865{
1866 for (unsigned int i = 0; i < t->num_targets; i++) {
1867 struct dm_target *ti = dm_table_get_target(t, i);
1868
1869 if (!ti->num_write_zeroes_bios)
1870 return false;
1871
1872 if (!ti->type->iterate_devices ||
1873 ti->type->iterate_devices(ti, device_not_write_zeroes_capable, NULL))
1874 return false;
1875 }
1876
1877 return true;
1878}
1879
1880static int device_not_nowait_capable(struct dm_target *ti, struct dm_dev *dev,
1881 sector_t start, sector_t len, void *data)
1882{
1883 return !bdev_nowait(dev->bdev);
1884}
1885
1886static bool dm_table_supports_nowait(struct dm_table *t)
1887{
1888 for (unsigned int i = 0; i < t->num_targets; i++) {
1889 struct dm_target *ti = dm_table_get_target(t, i);
1890
1891 if (!dm_target_supports_nowait(ti->type))
1892 return false;
1893
1894 if (!ti->type->iterate_devices ||
1895 ti->type->iterate_devices(ti, device_not_nowait_capable, NULL))
1896 return false;
1897 }
1898
1899 return true;
1900}
1901
1902static int device_not_discard_capable(struct dm_target *ti, struct dm_dev *dev,
1903 sector_t start, sector_t len, void *data)
1904{
1905 return !bdev_max_discard_sectors(dev->bdev);
1906}
1907
1908static bool dm_table_supports_discards(struct dm_table *t)
1909{
1910 for (unsigned int i = 0; i < t->num_targets; i++) {
1911 struct dm_target *ti = dm_table_get_target(t, i);
1912
1913 if (!ti->num_discard_bios)
1914 return false;
1915
1916 /*
1917 * Either the target provides discard support (as implied by setting
1918 * 'discards_supported') or it relies on _all_ data devices having
1919 * discard support.
1920 */
1921 if (!ti->discards_supported &&
1922 (!ti->type->iterate_devices ||
1923 ti->type->iterate_devices(ti, device_not_discard_capable, NULL)))
1924 return false;
1925 }
1926
1927 return true;
1928}
1929
1930static int device_not_secure_erase_capable(struct dm_target *ti,
1931 struct dm_dev *dev, sector_t start,
1932 sector_t len, void *data)
1933{
1934 return !bdev_max_secure_erase_sectors(dev->bdev);
1935}
1936
1937static bool dm_table_supports_secure_erase(struct dm_table *t)
1938{
1939 for (unsigned int i = 0; i < t->num_targets; i++) {
1940 struct dm_target *ti = dm_table_get_target(t, i);
1941
1942 if (!ti->num_secure_erase_bios)
1943 return false;
1944
1945 if (!ti->type->iterate_devices ||
1946 ti->type->iterate_devices(ti, device_not_secure_erase_capable, NULL))
1947 return false;
1948 }
1949
1950 return true;
1951}
1952
1953static int device_requires_stable_pages(struct dm_target *ti,
1954 struct dm_dev *dev, sector_t start,
1955 sector_t len, void *data)
1956{
1957 return bdev_stable_writes(dev->bdev);
1958}
1959
1960int dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
1961 struct queue_limits *limits)
1962{
1963 bool wc = false, fua = false;
1964 int r;
1965
1966 /*
1967 * Copy table's limits to the DM device's request_queue
1968 */
1969 q->limits = *limits;
1970
1971 if (dm_table_supports_nowait(t))
1972 blk_queue_flag_set(QUEUE_FLAG_NOWAIT, q);
1973 else
1974 blk_queue_flag_clear(QUEUE_FLAG_NOWAIT, q);
1975
1976 if (!dm_table_supports_discards(t)) {
1977 q->limits.max_discard_sectors = 0;
1978 q->limits.max_hw_discard_sectors = 0;
1979 q->limits.discard_granularity = 0;
1980 q->limits.discard_alignment = 0;
1981 q->limits.discard_misaligned = 0;
1982 }
1983
1984 if (!dm_table_supports_secure_erase(t))
1985 q->limits.max_secure_erase_sectors = 0;
1986
1987 if (dm_table_supports_flush(t, (1UL << QUEUE_FLAG_WC))) {
1988 wc = true;
1989 if (dm_table_supports_flush(t, (1UL << QUEUE_FLAG_FUA)))
1990 fua = true;
1991 }
1992 blk_queue_write_cache(q, wc, fua);
1993
1994 if (dm_table_supports_dax(t, device_not_dax_capable)) {
1995 blk_queue_flag_set(QUEUE_FLAG_DAX, q);
1996 if (dm_table_supports_dax(t, device_not_dax_synchronous_capable))
1997 set_dax_synchronous(t->md->dax_dev);
1998 } else
1999 blk_queue_flag_clear(QUEUE_FLAG_DAX, q);
2000
2001 if (dm_table_any_dev_attr(t, device_dax_write_cache_enabled, NULL))
2002 dax_write_cache(t->md->dax_dev, true);
2003
2004 /* Ensure that all underlying devices are non-rotational. */
2005 if (dm_table_any_dev_attr(t, device_is_rotational, NULL))
2006 blk_queue_flag_clear(QUEUE_FLAG_NONROT, q);
2007 else
2008 blk_queue_flag_set(QUEUE_FLAG_NONROT, q);
2009
2010 if (!dm_table_supports_write_zeroes(t))
2011 q->limits.max_write_zeroes_sectors = 0;
2012
2013 dm_table_verify_integrity(t);
2014
2015 /*
2016 * Some devices don't use blk_integrity but still want stable pages
2017 * because they do their own checksumming.
2018 * If any underlying device requires stable pages, a table must require
2019 * them as well. Only targets that support iterate_devices are considered:
2020 * don't want error, zero, etc to require stable pages.
2021 */
2022 if (dm_table_any_dev_attr(t, device_requires_stable_pages, NULL))
2023 blk_queue_flag_set(QUEUE_FLAG_STABLE_WRITES, q);
2024 else
2025 blk_queue_flag_clear(QUEUE_FLAG_STABLE_WRITES, q);
2026
2027 /*
2028 * Determine whether or not this queue's I/O timings contribute
2029 * to the entropy pool, Only request-based targets use this.
2030 * Clear QUEUE_FLAG_ADD_RANDOM if any underlying device does not
2031 * have it set.
2032 */
2033 if (blk_queue_add_random(q) &&
2034 dm_table_any_dev_attr(t, device_is_not_random, NULL))
2035 blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, q);
2036
2037 /*
2038 * For a zoned target, setup the zones related queue attributes
2039 * and resources necessary for zone append emulation if necessary.
2040 */
2041 if (blk_queue_is_zoned(q)) {
2042 r = dm_set_zones_restrictions(t, q);
2043 if (r)
2044 return r;
2045 if (!static_key_enabled(&zoned_enabled.key))
2046 static_branch_enable(&zoned_enabled);
2047 }
2048
2049 dm_update_crypto_profile(q, t);
2050 disk_update_readahead(t->md->disk);
2051
2052 /*
2053 * Check for request-based device is left to
2054 * dm_mq_init_request_queue()->blk_mq_init_allocated_queue().
2055 *
2056 * For bio-based device, only set QUEUE_FLAG_POLL when all
2057 * underlying devices supporting polling.
2058 */
2059 if (__table_type_bio_based(t->type)) {
2060 if (dm_table_supports_poll(t))
2061 blk_queue_flag_set(QUEUE_FLAG_POLL, q);
2062 else
2063 blk_queue_flag_clear(QUEUE_FLAG_POLL, q);
2064 }
2065
2066 return 0;
2067}
2068
2069struct list_head *dm_table_get_devices(struct dm_table *t)
2070{
2071 return &t->devices;
2072}
2073
2074blk_mode_t dm_table_get_mode(struct dm_table *t)
2075{
2076 return t->mode;
2077}
2078EXPORT_SYMBOL(dm_table_get_mode);
2079
2080enum suspend_mode {
2081 PRESUSPEND,
2082 PRESUSPEND_UNDO,
2083 POSTSUSPEND,
2084};
2085
2086static void suspend_targets(struct dm_table *t, enum suspend_mode mode)
2087{
2088 lockdep_assert_held(&t->md->suspend_lock);
2089
2090 for (unsigned int i = 0; i < t->num_targets; i++) {
2091 struct dm_target *ti = dm_table_get_target(t, i);
2092
2093 switch (mode) {
2094 case PRESUSPEND:
2095 if (ti->type->presuspend)
2096 ti->type->presuspend(ti);
2097 break;
2098 case PRESUSPEND_UNDO:
2099 if (ti->type->presuspend_undo)
2100 ti->type->presuspend_undo(ti);
2101 break;
2102 case POSTSUSPEND:
2103 if (ti->type->postsuspend)
2104 ti->type->postsuspend(ti);
2105 break;
2106 }
2107 }
2108}
2109
2110void dm_table_presuspend_targets(struct dm_table *t)
2111{
2112 if (!t)
2113 return;
2114
2115 suspend_targets(t, PRESUSPEND);
2116}
2117
2118void dm_table_presuspend_undo_targets(struct dm_table *t)
2119{
2120 if (!t)
2121 return;
2122
2123 suspend_targets(t, PRESUSPEND_UNDO);
2124}
2125
2126void dm_table_postsuspend_targets(struct dm_table *t)
2127{
2128 if (!t)
2129 return;
2130
2131 suspend_targets(t, POSTSUSPEND);
2132}
2133
2134int dm_table_resume_targets(struct dm_table *t)
2135{
2136 unsigned int i;
2137 int r = 0;
2138
2139 lockdep_assert_held(&t->md->suspend_lock);
2140
2141 for (i = 0; i < t->num_targets; i++) {
2142 struct dm_target *ti = dm_table_get_target(t, i);
2143
2144 if (!ti->type->preresume)
2145 continue;
2146
2147 r = ti->type->preresume(ti);
2148 if (r) {
2149 DMERR("%s: %s: preresume failed, error = %d",
2150 dm_device_name(t->md), ti->type->name, r);
2151 return r;
2152 }
2153 }
2154
2155 for (i = 0; i < t->num_targets; i++) {
2156 struct dm_target *ti = dm_table_get_target(t, i);
2157
2158 if (ti->type->resume)
2159 ti->type->resume(ti);
2160 }
2161
2162 return 0;
2163}
2164
2165struct mapped_device *dm_table_get_md(struct dm_table *t)
2166{
2167 return t->md;
2168}
2169EXPORT_SYMBOL(dm_table_get_md);
2170
2171const char *dm_table_device_name(struct dm_table *t)
2172{
2173 return dm_device_name(t->md);
2174}
2175EXPORT_SYMBOL_GPL(dm_table_device_name);
2176
2177void dm_table_run_md_queue_async(struct dm_table *t)
2178{
2179 if (!dm_table_request_based(t))
2180 return;
2181
2182 if (t->md->queue)
2183 blk_mq_run_hw_queues(t->md->queue, true);
2184}
2185EXPORT_SYMBOL(dm_table_run_md_queue_async);
2186
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
29/*
30 * The table has always exactly one reference from either mapped_device->map
31 * or hash_cell->new_map. This reference is not counted in table->holders.
32 * A pair of dm_create_table/dm_destroy_table functions is used for table
33 * creation/destruction.
34 *
35 * Temporary references from the other code increase table->holders. A pair
36 * of dm_table_get/dm_table_put functions is used to manipulate it.
37 *
38 * When the table is about to be destroyed, we wait for table->holders to
39 * drop to zero.
40 */
41
42struct dm_table {
43 struct mapped_device *md;
44 atomic_t holders;
45 unsigned type;
46
47 /* btree table */
48 unsigned int depth;
49 unsigned int counts[MAX_DEPTH]; /* in nodes */
50 sector_t *index[MAX_DEPTH];
51
52 unsigned int num_targets;
53 unsigned int num_allocated;
54 sector_t *highs;
55 struct dm_target *targets;
56
57 struct target_type *immutable_target_type;
58 unsigned integrity_supported:1;
59 unsigned singleton:1;
60
61 /*
62 * Indicates the rw permissions for the new logical
63 * device. This should be a combination of FMODE_READ
64 * and FMODE_WRITE.
65 */
66 fmode_t mode;
67
68 /* a list of devices used by this table */
69 struct list_head devices;
70
71 /* events get handed up using this callback */
72 void (*event_fn)(void *);
73 void *event_context;
74
75 struct dm_md_mempools *mempools;
76
77 struct list_head target_callbacks;
78};
79
80/*
81 * Similar to ceiling(log_size(n))
82 */
83static unsigned int int_log(unsigned int n, unsigned int base)
84{
85 int result = 0;
86
87 while (n > 1) {
88 n = dm_div_up(n, base);
89 result++;
90 }
91
92 return result;
93}
94
95/*
96 * Calculate the index of the child node of the n'th node k'th key.
97 */
98static inline unsigned int get_child(unsigned int n, unsigned int k)
99{
100 return (n * CHILDREN_PER_NODE) + k;
101}
102
103/*
104 * Return the n'th node of level l from table t.
105 */
106static inline sector_t *get_node(struct dm_table *t,
107 unsigned int l, unsigned int n)
108{
109 return t->index[l] + (n * KEYS_PER_NODE);
110}
111
112/*
113 * Return the highest key that you could lookup from the n'th
114 * node on level l of the btree.
115 */
116static sector_t high(struct dm_table *t, unsigned int l, unsigned int n)
117{
118 for (; l < t->depth - 1; l++)
119 n = get_child(n, CHILDREN_PER_NODE - 1);
120
121 if (n >= t->counts[l])
122 return (sector_t) - 1;
123
124 return get_node(t, l, n)[KEYS_PER_NODE - 1];
125}
126
127/*
128 * Fills in a level of the btree based on the highs of the level
129 * below it.
130 */
131static int setup_btree_index(unsigned int l, struct dm_table *t)
132{
133 unsigned int n, k;
134 sector_t *node;
135
136 for (n = 0U; n < t->counts[l]; n++) {
137 node = get_node(t, l, n);
138
139 for (k = 0U; k < KEYS_PER_NODE; k++)
140 node[k] = high(t, l + 1, get_child(n, k));
141 }
142
143 return 0;
144}
145
146void *dm_vcalloc(unsigned long nmemb, unsigned long elem_size)
147{
148 unsigned long size;
149 void *addr;
150
151 /*
152 * Check that we're not going to overflow.
153 */
154 if (nmemb > (ULONG_MAX / elem_size))
155 return NULL;
156
157 size = nmemb * elem_size;
158 addr = vzalloc(size);
159
160 return addr;
161}
162EXPORT_SYMBOL(dm_vcalloc);
163
164/*
165 * highs, and targets are managed as dynamic arrays during a
166 * table load.
167 */
168static int alloc_targets(struct dm_table *t, unsigned int num)
169{
170 sector_t *n_highs;
171 struct dm_target *n_targets;
172 int n = t->num_targets;
173
174 /*
175 * Allocate both the target array and offset array at once.
176 * Append an empty entry to catch sectors beyond the end of
177 * the device.
178 */
179 n_highs = (sector_t *) dm_vcalloc(num + 1, sizeof(struct dm_target) +
180 sizeof(sector_t));
181 if (!n_highs)
182 return -ENOMEM;
183
184 n_targets = (struct dm_target *) (n_highs + num);
185
186 if (n) {
187 memcpy(n_highs, t->highs, sizeof(*n_highs) * n);
188 memcpy(n_targets, t->targets, sizeof(*n_targets) * n);
189 }
190
191 memset(n_highs + n, -1, sizeof(*n_highs) * (num - n));
192 vfree(t->highs);
193
194 t->num_allocated = num;
195 t->highs = n_highs;
196 t->targets = n_targets;
197
198 return 0;
199}
200
201int dm_table_create(struct dm_table **result, fmode_t mode,
202 unsigned num_targets, struct mapped_device *md)
203{
204 struct dm_table *t = kzalloc(sizeof(*t), GFP_KERNEL);
205
206 if (!t)
207 return -ENOMEM;
208
209 INIT_LIST_HEAD(&t->devices);
210 INIT_LIST_HEAD(&t->target_callbacks);
211 atomic_set(&t->holders, 0);
212
213 if (!num_targets)
214 num_targets = KEYS_PER_NODE;
215
216 num_targets = dm_round_up(num_targets, KEYS_PER_NODE);
217
218 if (alloc_targets(t, num_targets)) {
219 kfree(t);
220 t = NULL;
221 return -ENOMEM;
222 }
223
224 t->mode = mode;
225 t->md = md;
226 *result = t;
227 return 0;
228}
229
230static void free_devices(struct list_head *devices)
231{
232 struct list_head *tmp, *next;
233
234 list_for_each_safe(tmp, next, devices) {
235 struct dm_dev_internal *dd =
236 list_entry(tmp, struct dm_dev_internal, list);
237 DMWARN("dm_table_destroy: dm_put_device call missing for %s",
238 dd->dm_dev.name);
239 kfree(dd);
240 }
241}
242
243void dm_table_destroy(struct dm_table *t)
244{
245 unsigned int i;
246
247 if (!t)
248 return;
249
250 while (atomic_read(&t->holders))
251 msleep(1);
252 smp_mb();
253
254 /* free the indexes */
255 if (t->depth >= 2)
256 vfree(t->index[t->depth - 2]);
257
258 /* free the targets */
259 for (i = 0; i < t->num_targets; i++) {
260 struct dm_target *tgt = t->targets + i;
261
262 if (tgt->type->dtr)
263 tgt->type->dtr(tgt);
264
265 dm_put_target_type(tgt->type);
266 }
267
268 vfree(t->highs);
269
270 /* free the device list */
271 free_devices(&t->devices);
272
273 dm_free_md_mempools(t->mempools);
274
275 kfree(t);
276}
277
278void dm_table_get(struct dm_table *t)
279{
280 atomic_inc(&t->holders);
281}
282EXPORT_SYMBOL(dm_table_get);
283
284void dm_table_put(struct dm_table *t)
285{
286 if (!t)
287 return;
288
289 smp_mb__before_atomic_dec();
290 atomic_dec(&t->holders);
291}
292EXPORT_SYMBOL(dm_table_put);
293
294/*
295 * Checks to see if we need to extend highs or targets.
296 */
297static inline int check_space(struct dm_table *t)
298{
299 if (t->num_targets >= t->num_allocated)
300 return alloc_targets(t, t->num_allocated * 2);
301
302 return 0;
303}
304
305/*
306 * See if we've already got a device in the list.
307 */
308static struct dm_dev_internal *find_device(struct list_head *l, dev_t dev)
309{
310 struct dm_dev_internal *dd;
311
312 list_for_each_entry (dd, l, list)
313 if (dd->dm_dev.bdev->bd_dev == dev)
314 return dd;
315
316 return NULL;
317}
318
319/*
320 * Open a device so we can use it as a map destination.
321 */
322static int open_dev(struct dm_dev_internal *d, dev_t dev,
323 struct mapped_device *md)
324{
325 static char *_claim_ptr = "I belong to device-mapper";
326 struct block_device *bdev;
327
328 int r;
329
330 BUG_ON(d->dm_dev.bdev);
331
332 bdev = blkdev_get_by_dev(dev, d->dm_dev.mode | FMODE_EXCL, _claim_ptr);
333 if (IS_ERR(bdev))
334 return PTR_ERR(bdev);
335
336 r = bd_link_disk_holder(bdev, dm_disk(md));
337 if (r) {
338 blkdev_put(bdev, d->dm_dev.mode | FMODE_EXCL);
339 return r;
340 }
341
342 d->dm_dev.bdev = bdev;
343 return 0;
344}
345
346/*
347 * Close a device that we've been using.
348 */
349static void close_dev(struct dm_dev_internal *d, struct mapped_device *md)
350{
351 if (!d->dm_dev.bdev)
352 return;
353
354 bd_unlink_disk_holder(d->dm_dev.bdev, dm_disk(md));
355 blkdev_put(d->dm_dev.bdev, d->dm_dev.mode | FMODE_EXCL);
356 d->dm_dev.bdev = NULL;
357}
358
359/*
360 * If possible, this checks an area of a destination device is invalid.
361 */
362static int device_area_is_invalid(struct dm_target *ti, struct dm_dev *dev,
363 sector_t start, sector_t len, void *data)
364{
365 struct request_queue *q;
366 struct queue_limits *limits = data;
367 struct block_device *bdev = dev->bdev;
368 sector_t dev_size =
369 i_size_read(bdev->bd_inode) >> SECTOR_SHIFT;
370 unsigned short logical_block_size_sectors =
371 limits->logical_block_size >> SECTOR_SHIFT;
372 char b[BDEVNAME_SIZE];
373
374 /*
375 * Some devices exist without request functions,
376 * such as loop devices not yet bound to backing files.
377 * Forbid the use of such devices.
378 */
379 q = bdev_get_queue(bdev);
380 if (!q || !q->make_request_fn) {
381 DMWARN("%s: %s is not yet initialised: "
382 "start=%llu, len=%llu, dev_size=%llu",
383 dm_device_name(ti->table->md), bdevname(bdev, b),
384 (unsigned long long)start,
385 (unsigned long long)len,
386 (unsigned long long)dev_size);
387 return 1;
388 }
389
390 if (!dev_size)
391 return 0;
392
393 if ((start >= dev_size) || (start + len > dev_size)) {
394 DMWARN("%s: %s too small for target: "
395 "start=%llu, len=%llu, dev_size=%llu",
396 dm_device_name(ti->table->md), bdevname(bdev, b),
397 (unsigned long long)start,
398 (unsigned long long)len,
399 (unsigned long long)dev_size);
400 return 1;
401 }
402
403 if (logical_block_size_sectors <= 1)
404 return 0;
405
406 if (start & (logical_block_size_sectors - 1)) {
407 DMWARN("%s: start=%llu not aligned to h/w "
408 "logical block size %u of %s",
409 dm_device_name(ti->table->md),
410 (unsigned long long)start,
411 limits->logical_block_size, bdevname(bdev, b));
412 return 1;
413 }
414
415 if (len & (logical_block_size_sectors - 1)) {
416 DMWARN("%s: len=%llu not aligned to h/w "
417 "logical block size %u of %s",
418 dm_device_name(ti->table->md),
419 (unsigned long long)len,
420 limits->logical_block_size, bdevname(bdev, b));
421 return 1;
422 }
423
424 return 0;
425}
426
427/*
428 * This upgrades the mode on an already open dm_dev, being
429 * careful to leave things as they were if we fail to reopen the
430 * device and not to touch the existing bdev field in case
431 * it is accessed concurrently inside dm_table_any_congested().
432 */
433static int upgrade_mode(struct dm_dev_internal *dd, fmode_t new_mode,
434 struct mapped_device *md)
435{
436 int r;
437 struct dm_dev_internal dd_new, dd_old;
438
439 dd_new = dd_old = *dd;
440
441 dd_new.dm_dev.mode |= new_mode;
442 dd_new.dm_dev.bdev = NULL;
443
444 r = open_dev(&dd_new, dd->dm_dev.bdev->bd_dev, md);
445 if (r)
446 return r;
447
448 dd->dm_dev.mode |= new_mode;
449 close_dev(&dd_old, md);
450
451 return 0;
452}
453
454/*
455 * Add a device to the list, or just increment the usage count if
456 * it's already present.
457 */
458int dm_get_device(struct dm_target *ti, const char *path, fmode_t mode,
459 struct dm_dev **result)
460{
461 int r;
462 dev_t uninitialized_var(dev);
463 struct dm_dev_internal *dd;
464 unsigned int major, minor;
465 struct dm_table *t = ti->table;
466 char dummy;
467
468 BUG_ON(!t);
469
470 if (sscanf(path, "%u:%u%c", &major, &minor, &dummy) == 2) {
471 /* Extract the major/minor numbers */
472 dev = MKDEV(major, minor);
473 if (MAJOR(dev) != major || MINOR(dev) != minor)
474 return -EOVERFLOW;
475 } else {
476 /* convert the path to a device */
477 struct block_device *bdev = lookup_bdev(path);
478
479 if (IS_ERR(bdev))
480 return PTR_ERR(bdev);
481 dev = bdev->bd_dev;
482 bdput(bdev);
483 }
484
485 dd = find_device(&t->devices, dev);
486 if (!dd) {
487 dd = kmalloc(sizeof(*dd), GFP_KERNEL);
488 if (!dd)
489 return -ENOMEM;
490
491 dd->dm_dev.mode = mode;
492 dd->dm_dev.bdev = NULL;
493
494 if ((r = open_dev(dd, dev, t->md))) {
495 kfree(dd);
496 return r;
497 }
498
499 format_dev_t(dd->dm_dev.name, dev);
500
501 atomic_set(&dd->count, 0);
502 list_add(&dd->list, &t->devices);
503
504 } else if (dd->dm_dev.mode != (mode | dd->dm_dev.mode)) {
505 r = upgrade_mode(dd, mode, t->md);
506 if (r)
507 return r;
508 }
509 atomic_inc(&dd->count);
510
511 *result = &dd->dm_dev;
512 return 0;
513}
514EXPORT_SYMBOL(dm_get_device);
515
516int dm_set_device_limits(struct dm_target *ti, struct dm_dev *dev,
517 sector_t start, sector_t len, void *data)
518{
519 struct queue_limits *limits = data;
520 struct block_device *bdev = dev->bdev;
521 struct request_queue *q = bdev_get_queue(bdev);
522 char b[BDEVNAME_SIZE];
523
524 if (unlikely(!q)) {
525 DMWARN("%s: Cannot set limits for nonexistent device %s",
526 dm_device_name(ti->table->md), bdevname(bdev, b));
527 return 0;
528 }
529
530 if (bdev_stack_limits(limits, bdev, start) < 0)
531 DMWARN("%s: adding target device %s caused an alignment inconsistency: "
532 "physical_block_size=%u, logical_block_size=%u, "
533 "alignment_offset=%u, start=%llu",
534 dm_device_name(ti->table->md), bdevname(bdev, b),
535 q->limits.physical_block_size,
536 q->limits.logical_block_size,
537 q->limits.alignment_offset,
538 (unsigned long long) start << SECTOR_SHIFT);
539
540 /*
541 * Check if merge fn is supported.
542 * If not we'll force DM to use PAGE_SIZE or
543 * smaller I/O, just to be safe.
544 */
545 if (dm_queue_merge_is_compulsory(q) && !ti->type->merge)
546 blk_limits_max_hw_sectors(limits,
547 (unsigned int) (PAGE_SIZE >> 9));
548 return 0;
549}
550EXPORT_SYMBOL_GPL(dm_set_device_limits);
551
552/*
553 * Decrement a device's use count and remove it if necessary.
554 */
555void dm_put_device(struct dm_target *ti, struct dm_dev *d)
556{
557 struct dm_dev_internal *dd = container_of(d, struct dm_dev_internal,
558 dm_dev);
559
560 if (atomic_dec_and_test(&dd->count)) {
561 close_dev(dd, ti->table->md);
562 list_del(&dd->list);
563 kfree(dd);
564 }
565}
566EXPORT_SYMBOL(dm_put_device);
567
568/*
569 * Checks to see if the target joins onto the end of the table.
570 */
571static int adjoin(struct dm_table *table, struct dm_target *ti)
572{
573 struct dm_target *prev;
574
575 if (!table->num_targets)
576 return !ti->begin;
577
578 prev = &table->targets[table->num_targets - 1];
579 return (ti->begin == (prev->begin + prev->len));
580}
581
582/*
583 * Used to dynamically allocate the arg array.
584 */
585static char **realloc_argv(unsigned *array_size, char **old_argv)
586{
587 char **argv;
588 unsigned new_size;
589
590 new_size = *array_size ? *array_size * 2 : 64;
591 argv = kmalloc(new_size * sizeof(*argv), GFP_KERNEL);
592 if (argv) {
593 memcpy(argv, old_argv, *array_size * sizeof(*argv));
594 *array_size = new_size;
595 }
596
597 kfree(old_argv);
598 return argv;
599}
600
601/*
602 * Destructively splits up the argument list to pass to ctr.
603 */
604int dm_split_args(int *argc, char ***argvp, char *input)
605{
606 char *start, *end = input, *out, **argv = NULL;
607 unsigned array_size = 0;
608
609 *argc = 0;
610
611 if (!input) {
612 *argvp = NULL;
613 return 0;
614 }
615
616 argv = realloc_argv(&array_size, argv);
617 if (!argv)
618 return -ENOMEM;
619
620 while (1) {
621 /* Skip whitespace */
622 start = skip_spaces(end);
623
624 if (!*start)
625 break; /* success, we hit the end */
626
627 /* 'out' is used to remove any back-quotes */
628 end = out = start;
629 while (*end) {
630 /* Everything apart from '\0' can be quoted */
631 if (*end == '\\' && *(end + 1)) {
632 *out++ = *(end + 1);
633 end += 2;
634 continue;
635 }
636
637 if (isspace(*end))
638 break; /* end of token */
639
640 *out++ = *end++;
641 }
642
643 /* have we already filled the array ? */
644 if ((*argc + 1) > array_size) {
645 argv = realloc_argv(&array_size, argv);
646 if (!argv)
647 return -ENOMEM;
648 }
649
650 /* we know this is whitespace */
651 if (*end)
652 end++;
653
654 /* terminate the string and put it in the array */
655 *out = '\0';
656 argv[*argc] = start;
657 (*argc)++;
658 }
659
660 *argvp = argv;
661 return 0;
662}
663
664/*
665 * Impose necessary and sufficient conditions on a devices's table such
666 * that any incoming bio which respects its logical_block_size can be
667 * processed successfully. If it falls across the boundary between
668 * two or more targets, the size of each piece it gets split into must
669 * be compatible with the logical_block_size of the target processing it.
670 */
671static int validate_hardware_logical_block_alignment(struct dm_table *table,
672 struct queue_limits *limits)
673{
674 /*
675 * This function uses arithmetic modulo the logical_block_size
676 * (in units of 512-byte sectors).
677 */
678 unsigned short device_logical_block_size_sects =
679 limits->logical_block_size >> SECTOR_SHIFT;
680
681 /*
682 * Offset of the start of the next table entry, mod logical_block_size.
683 */
684 unsigned short next_target_start = 0;
685
686 /*
687 * Given an aligned bio that extends beyond the end of a
688 * target, how many sectors must the next target handle?
689 */
690 unsigned short remaining = 0;
691
692 struct dm_target *uninitialized_var(ti);
693 struct queue_limits ti_limits;
694 unsigned i = 0;
695
696 /*
697 * Check each entry in the table in turn.
698 */
699 while (i < dm_table_get_num_targets(table)) {
700 ti = dm_table_get_target(table, i++);
701
702 blk_set_stacking_limits(&ti_limits);
703
704 /* combine all target devices' limits */
705 if (ti->type->iterate_devices)
706 ti->type->iterate_devices(ti, dm_set_device_limits,
707 &ti_limits);
708
709 /*
710 * If the remaining sectors fall entirely within this
711 * table entry are they compatible with its logical_block_size?
712 */
713 if (remaining < ti->len &&
714 remaining & ((ti_limits.logical_block_size >>
715 SECTOR_SHIFT) - 1))
716 break; /* Error */
717
718 next_target_start =
719 (unsigned short) ((next_target_start + ti->len) &
720 (device_logical_block_size_sects - 1));
721 remaining = next_target_start ?
722 device_logical_block_size_sects - next_target_start : 0;
723 }
724
725 if (remaining) {
726 DMWARN("%s: table line %u (start sect %llu len %llu) "
727 "not aligned to h/w logical block size %u",
728 dm_device_name(table->md), i,
729 (unsigned long long) ti->begin,
730 (unsigned long long) ti->len,
731 limits->logical_block_size);
732 return -EINVAL;
733 }
734
735 return 0;
736}
737
738int dm_table_add_target(struct dm_table *t, const char *type,
739 sector_t start, sector_t len, char *params)
740{
741 int r = -EINVAL, argc;
742 char **argv;
743 struct dm_target *tgt;
744
745 if (t->singleton) {
746 DMERR("%s: target type %s must appear alone in table",
747 dm_device_name(t->md), t->targets->type->name);
748 return -EINVAL;
749 }
750
751 if ((r = check_space(t)))
752 return r;
753
754 tgt = t->targets + t->num_targets;
755 memset(tgt, 0, sizeof(*tgt));
756
757 if (!len) {
758 DMERR("%s: zero-length target", dm_device_name(t->md));
759 return -EINVAL;
760 }
761
762 tgt->type = dm_get_target_type(type);
763 if (!tgt->type) {
764 DMERR("%s: %s: unknown target type", dm_device_name(t->md),
765 type);
766 return -EINVAL;
767 }
768
769 if (dm_target_needs_singleton(tgt->type)) {
770 if (t->num_targets) {
771 DMERR("%s: target type %s must appear alone in table",
772 dm_device_name(t->md), type);
773 return -EINVAL;
774 }
775 t->singleton = 1;
776 }
777
778 if (dm_target_always_writeable(tgt->type) && !(t->mode & FMODE_WRITE)) {
779 DMERR("%s: target type %s may not be included in read-only tables",
780 dm_device_name(t->md), type);
781 return -EINVAL;
782 }
783
784 if (t->immutable_target_type) {
785 if (t->immutable_target_type != tgt->type) {
786 DMERR("%s: immutable target type %s cannot be mixed with other target types",
787 dm_device_name(t->md), t->immutable_target_type->name);
788 return -EINVAL;
789 }
790 } else if (dm_target_is_immutable(tgt->type)) {
791 if (t->num_targets) {
792 DMERR("%s: immutable target type %s cannot be mixed with other target types",
793 dm_device_name(t->md), tgt->type->name);
794 return -EINVAL;
795 }
796 t->immutable_target_type = tgt->type;
797 }
798
799 tgt->table = t;
800 tgt->begin = start;
801 tgt->len = len;
802 tgt->error = "Unknown error";
803
804 /*
805 * Does this target adjoin the previous one ?
806 */
807 if (!adjoin(t, tgt)) {
808 tgt->error = "Gap in table";
809 r = -EINVAL;
810 goto bad;
811 }
812
813 r = dm_split_args(&argc, &argv, params);
814 if (r) {
815 tgt->error = "couldn't split parameters (insufficient memory)";
816 goto bad;
817 }
818
819 r = tgt->type->ctr(tgt, argc, argv);
820 kfree(argv);
821 if (r)
822 goto bad;
823
824 t->highs[t->num_targets++] = tgt->begin + tgt->len - 1;
825
826 if (!tgt->num_discard_requests && tgt->discards_supported)
827 DMWARN("%s: %s: ignoring discards_supported because num_discard_requests is zero.",
828 dm_device_name(t->md), type);
829
830 return 0;
831
832 bad:
833 DMERR("%s: %s: %s", dm_device_name(t->md), type, tgt->error);
834 dm_put_target_type(tgt->type);
835 return r;
836}
837
838/*
839 * Target argument parsing helpers.
840 */
841static int validate_next_arg(struct dm_arg *arg, struct dm_arg_set *arg_set,
842 unsigned *value, char **error, unsigned grouped)
843{
844 const char *arg_str = dm_shift_arg(arg_set);
845 char dummy;
846
847 if (!arg_str ||
848 (sscanf(arg_str, "%u%c", value, &dummy) != 1) ||
849 (*value < arg->min) ||
850 (*value > arg->max) ||
851 (grouped && arg_set->argc < *value)) {
852 *error = arg->error;
853 return -EINVAL;
854 }
855
856 return 0;
857}
858
859int dm_read_arg(struct dm_arg *arg, struct dm_arg_set *arg_set,
860 unsigned *value, char **error)
861{
862 return validate_next_arg(arg, arg_set, value, error, 0);
863}
864EXPORT_SYMBOL(dm_read_arg);
865
866int dm_read_arg_group(struct dm_arg *arg, struct dm_arg_set *arg_set,
867 unsigned *value, char **error)
868{
869 return validate_next_arg(arg, arg_set, value, error, 1);
870}
871EXPORT_SYMBOL(dm_read_arg_group);
872
873const char *dm_shift_arg(struct dm_arg_set *as)
874{
875 char *r;
876
877 if (as->argc) {
878 as->argc--;
879 r = *as->argv;
880 as->argv++;
881 return r;
882 }
883
884 return NULL;
885}
886EXPORT_SYMBOL(dm_shift_arg);
887
888void dm_consume_args(struct dm_arg_set *as, unsigned num_args)
889{
890 BUG_ON(as->argc < num_args);
891 as->argc -= num_args;
892 as->argv += num_args;
893}
894EXPORT_SYMBOL(dm_consume_args);
895
896static int dm_table_set_type(struct dm_table *t)
897{
898 unsigned i;
899 unsigned bio_based = 0, request_based = 0;
900 struct dm_target *tgt;
901 struct dm_dev_internal *dd;
902 struct list_head *devices;
903
904 for (i = 0; i < t->num_targets; i++) {
905 tgt = t->targets + i;
906 if (dm_target_request_based(tgt))
907 request_based = 1;
908 else
909 bio_based = 1;
910
911 if (bio_based && request_based) {
912 DMWARN("Inconsistent table: different target types"
913 " can't be mixed up");
914 return -EINVAL;
915 }
916 }
917
918 if (bio_based) {
919 /* We must use this table as bio-based */
920 t->type = DM_TYPE_BIO_BASED;
921 return 0;
922 }
923
924 BUG_ON(!request_based); /* No targets in this table */
925
926 /* Non-request-stackable devices can't be used for request-based dm */
927 devices = dm_table_get_devices(t);
928 list_for_each_entry(dd, devices, list) {
929 if (!blk_queue_stackable(bdev_get_queue(dd->dm_dev.bdev))) {
930 DMWARN("table load rejected: including"
931 " non-request-stackable devices");
932 return -EINVAL;
933 }
934 }
935
936 /*
937 * Request-based dm supports only tables that have a single target now.
938 * To support multiple targets, request splitting support is needed,
939 * and that needs lots of changes in the block-layer.
940 * (e.g. request completion process for partial completion.)
941 */
942 if (t->num_targets > 1) {
943 DMWARN("Request-based dm doesn't support multiple targets yet");
944 return -EINVAL;
945 }
946
947 t->type = DM_TYPE_REQUEST_BASED;
948
949 return 0;
950}
951
952unsigned dm_table_get_type(struct dm_table *t)
953{
954 return t->type;
955}
956
957struct target_type *dm_table_get_immutable_target_type(struct dm_table *t)
958{
959 return t->immutable_target_type;
960}
961
962bool dm_table_request_based(struct dm_table *t)
963{
964 return dm_table_get_type(t) == DM_TYPE_REQUEST_BASED;
965}
966
967int dm_table_alloc_md_mempools(struct dm_table *t)
968{
969 unsigned type = dm_table_get_type(t);
970
971 if (unlikely(type == DM_TYPE_NONE)) {
972 DMWARN("no table type is set, can't allocate mempools");
973 return -EINVAL;
974 }
975
976 t->mempools = dm_alloc_md_mempools(type, t->integrity_supported);
977 if (!t->mempools)
978 return -ENOMEM;
979
980 return 0;
981}
982
983void dm_table_free_md_mempools(struct dm_table *t)
984{
985 dm_free_md_mempools(t->mempools);
986 t->mempools = NULL;
987}
988
989struct dm_md_mempools *dm_table_get_md_mempools(struct dm_table *t)
990{
991 return t->mempools;
992}
993
994static int setup_indexes(struct dm_table *t)
995{
996 int i;
997 unsigned int total = 0;
998 sector_t *indexes;
999
1000 /* allocate the space for *all* the indexes */
1001 for (i = t->depth - 2; i >= 0; i--) {
1002 t->counts[i] = dm_div_up(t->counts[i + 1], CHILDREN_PER_NODE);
1003 total += t->counts[i];
1004 }
1005
1006 indexes = (sector_t *) dm_vcalloc(total, (unsigned long) NODE_SIZE);
1007 if (!indexes)
1008 return -ENOMEM;
1009
1010 /* set up internal nodes, bottom-up */
1011 for (i = t->depth - 2; i >= 0; i--) {
1012 t->index[i] = indexes;
1013 indexes += (KEYS_PER_NODE * t->counts[i]);
1014 setup_btree_index(i, t);
1015 }
1016
1017 return 0;
1018}
1019
1020/*
1021 * Builds the btree to index the map.
1022 */
1023static int dm_table_build_index(struct dm_table *t)
1024{
1025 int r = 0;
1026 unsigned int leaf_nodes;
1027
1028 /* how many indexes will the btree have ? */
1029 leaf_nodes = dm_div_up(t->num_targets, KEYS_PER_NODE);
1030 t->depth = 1 + int_log(leaf_nodes, CHILDREN_PER_NODE);
1031
1032 /* leaf layer has already been set up */
1033 t->counts[t->depth - 1] = leaf_nodes;
1034 t->index[t->depth - 1] = t->highs;
1035
1036 if (t->depth >= 2)
1037 r = setup_indexes(t);
1038
1039 return r;
1040}
1041
1042/*
1043 * Get a disk whose integrity profile reflects the table's profile.
1044 * If %match_all is true, all devices' profiles must match.
1045 * If %match_all is false, all devices must at least have an
1046 * allocated integrity profile; but uninitialized is ok.
1047 * Returns NULL if integrity support was inconsistent or unavailable.
1048 */
1049static struct gendisk * dm_table_get_integrity_disk(struct dm_table *t,
1050 bool match_all)
1051{
1052 struct list_head *devices = dm_table_get_devices(t);
1053 struct dm_dev_internal *dd = NULL;
1054 struct gendisk *prev_disk = NULL, *template_disk = NULL;
1055
1056 list_for_each_entry(dd, devices, list) {
1057 template_disk = dd->dm_dev.bdev->bd_disk;
1058 if (!blk_get_integrity(template_disk))
1059 goto no_integrity;
1060 if (!match_all && !blk_integrity_is_initialized(template_disk))
1061 continue; /* skip uninitialized profiles */
1062 else if (prev_disk &&
1063 blk_integrity_compare(prev_disk, template_disk) < 0)
1064 goto no_integrity;
1065 prev_disk = template_disk;
1066 }
1067
1068 return template_disk;
1069
1070no_integrity:
1071 if (prev_disk)
1072 DMWARN("%s: integrity not set: %s and %s profile mismatch",
1073 dm_device_name(t->md),
1074 prev_disk->disk_name,
1075 template_disk->disk_name);
1076 return NULL;
1077}
1078
1079/*
1080 * Register the mapped device for blk_integrity support if
1081 * the underlying devices have an integrity profile. But all devices
1082 * may not have matching profiles (checking all devices isn't reliable
1083 * during table load because this table may use other DM device(s) which
1084 * must be resumed before they will have an initialized integity profile).
1085 * Stacked DM devices force a 2 stage integrity profile validation:
1086 * 1 - during load, validate all initialized integrity profiles match
1087 * 2 - during resume, validate all integrity profiles match
1088 */
1089static int dm_table_prealloc_integrity(struct dm_table *t, struct mapped_device *md)
1090{
1091 struct gendisk *template_disk = NULL;
1092
1093 template_disk = dm_table_get_integrity_disk(t, false);
1094 if (!template_disk)
1095 return 0;
1096
1097 if (!blk_integrity_is_initialized(dm_disk(md))) {
1098 t->integrity_supported = 1;
1099 return blk_integrity_register(dm_disk(md), NULL);
1100 }
1101
1102 /*
1103 * If DM device already has an initalized integrity
1104 * profile the new profile should not conflict.
1105 */
1106 if (blk_integrity_is_initialized(template_disk) &&
1107 blk_integrity_compare(dm_disk(md), template_disk) < 0) {
1108 DMWARN("%s: conflict with existing integrity profile: "
1109 "%s profile mismatch",
1110 dm_device_name(t->md),
1111 template_disk->disk_name);
1112 return 1;
1113 }
1114
1115 /* Preserve existing initialized integrity profile */
1116 t->integrity_supported = 1;
1117 return 0;
1118}
1119
1120/*
1121 * Prepares the table for use by building the indices,
1122 * setting the type, and allocating mempools.
1123 */
1124int dm_table_complete(struct dm_table *t)
1125{
1126 int r;
1127
1128 r = dm_table_set_type(t);
1129 if (r) {
1130 DMERR("unable to set table type");
1131 return r;
1132 }
1133
1134 r = dm_table_build_index(t);
1135 if (r) {
1136 DMERR("unable to build btrees");
1137 return r;
1138 }
1139
1140 r = dm_table_prealloc_integrity(t, t->md);
1141 if (r) {
1142 DMERR("could not register integrity profile.");
1143 return r;
1144 }
1145
1146 r = dm_table_alloc_md_mempools(t);
1147 if (r)
1148 DMERR("unable to allocate mempools");
1149
1150 return r;
1151}
1152
1153static DEFINE_MUTEX(_event_lock);
1154void dm_table_event_callback(struct dm_table *t,
1155 void (*fn)(void *), void *context)
1156{
1157 mutex_lock(&_event_lock);
1158 t->event_fn = fn;
1159 t->event_context = context;
1160 mutex_unlock(&_event_lock);
1161}
1162
1163void dm_table_event(struct dm_table *t)
1164{
1165 /*
1166 * You can no longer call dm_table_event() from interrupt
1167 * context, use a bottom half instead.
1168 */
1169 BUG_ON(in_interrupt());
1170
1171 mutex_lock(&_event_lock);
1172 if (t->event_fn)
1173 t->event_fn(t->event_context);
1174 mutex_unlock(&_event_lock);
1175}
1176EXPORT_SYMBOL(dm_table_event);
1177
1178sector_t dm_table_get_size(struct dm_table *t)
1179{
1180 return t->num_targets ? (t->highs[t->num_targets - 1] + 1) : 0;
1181}
1182EXPORT_SYMBOL(dm_table_get_size);
1183
1184struct dm_target *dm_table_get_target(struct dm_table *t, unsigned int index)
1185{
1186 if (index >= t->num_targets)
1187 return NULL;
1188
1189 return t->targets + index;
1190}
1191
1192/*
1193 * Search the btree for the correct target.
1194 *
1195 * Caller should check returned pointer with dm_target_is_valid()
1196 * to trap I/O beyond end of device.
1197 */
1198struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector)
1199{
1200 unsigned int l, n = 0, k = 0;
1201 sector_t *node;
1202
1203 for (l = 0; l < t->depth; l++) {
1204 n = get_child(n, k);
1205 node = get_node(t, l, n);
1206
1207 for (k = 0; k < KEYS_PER_NODE; k++)
1208 if (node[k] >= sector)
1209 break;
1210 }
1211
1212 return &t->targets[(KEYS_PER_NODE * n) + k];
1213}
1214
1215/*
1216 * Establish the new table's queue_limits and validate them.
1217 */
1218int dm_calculate_queue_limits(struct dm_table *table,
1219 struct queue_limits *limits)
1220{
1221 struct dm_target *uninitialized_var(ti);
1222 struct queue_limits ti_limits;
1223 unsigned i = 0;
1224
1225 blk_set_stacking_limits(limits);
1226
1227 while (i < dm_table_get_num_targets(table)) {
1228 blk_set_stacking_limits(&ti_limits);
1229
1230 ti = dm_table_get_target(table, i++);
1231
1232 if (!ti->type->iterate_devices)
1233 goto combine_limits;
1234
1235 /*
1236 * Combine queue limits of all the devices this target uses.
1237 */
1238 ti->type->iterate_devices(ti, dm_set_device_limits,
1239 &ti_limits);
1240
1241 /* Set I/O hints portion of queue limits */
1242 if (ti->type->io_hints)
1243 ti->type->io_hints(ti, &ti_limits);
1244
1245 /*
1246 * Check each device area is consistent with the target's
1247 * overall queue limits.
1248 */
1249 if (ti->type->iterate_devices(ti, device_area_is_invalid,
1250 &ti_limits))
1251 return -EINVAL;
1252
1253combine_limits:
1254 /*
1255 * Merge this target's queue limits into the overall limits
1256 * for the table.
1257 */
1258 if (blk_stack_limits(limits, &ti_limits, 0) < 0)
1259 DMWARN("%s: adding target device "
1260 "(start sect %llu len %llu) "
1261 "caused an alignment inconsistency",
1262 dm_device_name(table->md),
1263 (unsigned long long) ti->begin,
1264 (unsigned long long) ti->len);
1265 }
1266
1267 return validate_hardware_logical_block_alignment(table, limits);
1268}
1269
1270/*
1271 * Set the integrity profile for this device if all devices used have
1272 * matching profiles. We're quite deep in the resume path but still
1273 * don't know if all devices (particularly DM devices this device
1274 * may be stacked on) have matching profiles. Even if the profiles
1275 * don't match we have no way to fail (to resume) at this point.
1276 */
1277static void dm_table_set_integrity(struct dm_table *t)
1278{
1279 struct gendisk *template_disk = NULL;
1280
1281 if (!blk_get_integrity(dm_disk(t->md)))
1282 return;
1283
1284 template_disk = dm_table_get_integrity_disk(t, true);
1285 if (template_disk)
1286 blk_integrity_register(dm_disk(t->md),
1287 blk_get_integrity(template_disk));
1288 else if (blk_integrity_is_initialized(dm_disk(t->md)))
1289 DMWARN("%s: device no longer has a valid integrity profile",
1290 dm_device_name(t->md));
1291 else
1292 DMWARN("%s: unable to establish an integrity profile",
1293 dm_device_name(t->md));
1294}
1295
1296static int device_flush_capable(struct dm_target *ti, struct dm_dev *dev,
1297 sector_t start, sector_t len, void *data)
1298{
1299 unsigned flush = (*(unsigned *)data);
1300 struct request_queue *q = bdev_get_queue(dev->bdev);
1301
1302 return q && (q->flush_flags & flush);
1303}
1304
1305static bool dm_table_supports_flush(struct dm_table *t, unsigned flush)
1306{
1307 struct dm_target *ti;
1308 unsigned i = 0;
1309
1310 /*
1311 * Require at least one underlying device to support flushes.
1312 * t->devices includes internal dm devices such as mirror logs
1313 * so we need to use iterate_devices here, which targets
1314 * supporting flushes must provide.
1315 */
1316 while (i < dm_table_get_num_targets(t)) {
1317 ti = dm_table_get_target(t, i++);
1318
1319 if (!ti->num_flush_requests)
1320 continue;
1321
1322 if (ti->type->iterate_devices &&
1323 ti->type->iterate_devices(ti, device_flush_capable, &flush))
1324 return 1;
1325 }
1326
1327 return 0;
1328}
1329
1330static bool dm_table_discard_zeroes_data(struct dm_table *t)
1331{
1332 struct dm_target *ti;
1333 unsigned i = 0;
1334
1335 /* Ensure that all targets supports discard_zeroes_data. */
1336 while (i < dm_table_get_num_targets(t)) {
1337 ti = dm_table_get_target(t, i++);
1338
1339 if (ti->discard_zeroes_data_unsupported)
1340 return 0;
1341 }
1342
1343 return 1;
1344}
1345
1346static int device_is_nonrot(struct dm_target *ti, struct dm_dev *dev,
1347 sector_t start, sector_t len, void *data)
1348{
1349 struct request_queue *q = bdev_get_queue(dev->bdev);
1350
1351 return q && blk_queue_nonrot(q);
1352}
1353
1354static int device_is_not_random(struct dm_target *ti, struct dm_dev *dev,
1355 sector_t start, sector_t len, void *data)
1356{
1357 struct request_queue *q = bdev_get_queue(dev->bdev);
1358
1359 return q && !blk_queue_add_random(q);
1360}
1361
1362static bool dm_table_all_devices_attribute(struct dm_table *t,
1363 iterate_devices_callout_fn func)
1364{
1365 struct dm_target *ti;
1366 unsigned i = 0;
1367
1368 while (i < dm_table_get_num_targets(t)) {
1369 ti = dm_table_get_target(t, i++);
1370
1371 if (!ti->type->iterate_devices ||
1372 !ti->type->iterate_devices(ti, func, NULL))
1373 return 0;
1374 }
1375
1376 return 1;
1377}
1378
1379void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
1380 struct queue_limits *limits)
1381{
1382 unsigned flush = 0;
1383
1384 /*
1385 * Copy table's limits to the DM device's request_queue
1386 */
1387 q->limits = *limits;
1388
1389 if (!dm_table_supports_discards(t))
1390 queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, q);
1391 else
1392 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q);
1393
1394 if (dm_table_supports_flush(t, REQ_FLUSH)) {
1395 flush |= REQ_FLUSH;
1396 if (dm_table_supports_flush(t, REQ_FUA))
1397 flush |= REQ_FUA;
1398 }
1399 blk_queue_flush(q, flush);
1400
1401 if (!dm_table_discard_zeroes_data(t))
1402 q->limits.discard_zeroes_data = 0;
1403
1404 /* Ensure that all underlying devices are non-rotational. */
1405 if (dm_table_all_devices_attribute(t, device_is_nonrot))
1406 queue_flag_set_unlocked(QUEUE_FLAG_NONROT, q);
1407 else
1408 queue_flag_clear_unlocked(QUEUE_FLAG_NONROT, q);
1409
1410 dm_table_set_integrity(t);
1411
1412 /*
1413 * Determine whether or not this queue's I/O timings contribute
1414 * to the entropy pool, Only request-based targets use this.
1415 * Clear QUEUE_FLAG_ADD_RANDOM if any underlying device does not
1416 * have it set.
1417 */
1418 if (blk_queue_add_random(q) && dm_table_all_devices_attribute(t, device_is_not_random))
1419 queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, q);
1420
1421 /*
1422 * QUEUE_FLAG_STACKABLE must be set after all queue settings are
1423 * visible to other CPUs because, once the flag is set, incoming bios
1424 * are processed by request-based dm, which refers to the queue
1425 * settings.
1426 * Until the flag set, bios are passed to bio-based dm and queued to
1427 * md->deferred where queue settings are not needed yet.
1428 * Those bios are passed to request-based dm at the resume time.
1429 */
1430 smp_mb();
1431 if (dm_table_request_based(t))
1432 queue_flag_set_unlocked(QUEUE_FLAG_STACKABLE, q);
1433}
1434
1435unsigned int dm_table_get_num_targets(struct dm_table *t)
1436{
1437 return t->num_targets;
1438}
1439
1440struct list_head *dm_table_get_devices(struct dm_table *t)
1441{
1442 return &t->devices;
1443}
1444
1445fmode_t dm_table_get_mode(struct dm_table *t)
1446{
1447 return t->mode;
1448}
1449EXPORT_SYMBOL(dm_table_get_mode);
1450
1451static void suspend_targets(struct dm_table *t, unsigned postsuspend)
1452{
1453 int i = t->num_targets;
1454 struct dm_target *ti = t->targets;
1455
1456 while (i--) {
1457 if (postsuspend) {
1458 if (ti->type->postsuspend)
1459 ti->type->postsuspend(ti);
1460 } else if (ti->type->presuspend)
1461 ti->type->presuspend(ti);
1462
1463 ti++;
1464 }
1465}
1466
1467void dm_table_presuspend_targets(struct dm_table *t)
1468{
1469 if (!t)
1470 return;
1471
1472 suspend_targets(t, 0);
1473}
1474
1475void dm_table_postsuspend_targets(struct dm_table *t)
1476{
1477 if (!t)
1478 return;
1479
1480 suspend_targets(t, 1);
1481}
1482
1483int dm_table_resume_targets(struct dm_table *t)
1484{
1485 int i, r = 0;
1486
1487 for (i = 0; i < t->num_targets; i++) {
1488 struct dm_target *ti = t->targets + i;
1489
1490 if (!ti->type->preresume)
1491 continue;
1492
1493 r = ti->type->preresume(ti);
1494 if (r)
1495 return r;
1496 }
1497
1498 for (i = 0; i < t->num_targets; i++) {
1499 struct dm_target *ti = t->targets + i;
1500
1501 if (ti->type->resume)
1502 ti->type->resume(ti);
1503 }
1504
1505 return 0;
1506}
1507
1508void dm_table_add_target_callbacks(struct dm_table *t, struct dm_target_callbacks *cb)
1509{
1510 list_add(&cb->list, &t->target_callbacks);
1511}
1512EXPORT_SYMBOL_GPL(dm_table_add_target_callbacks);
1513
1514int dm_table_any_congested(struct dm_table *t, int bdi_bits)
1515{
1516 struct dm_dev_internal *dd;
1517 struct list_head *devices = dm_table_get_devices(t);
1518 struct dm_target_callbacks *cb;
1519 int r = 0;
1520
1521 list_for_each_entry(dd, devices, list) {
1522 struct request_queue *q = bdev_get_queue(dd->dm_dev.bdev);
1523 char b[BDEVNAME_SIZE];
1524
1525 if (likely(q))
1526 r |= bdi_congested(&q->backing_dev_info, bdi_bits);
1527 else
1528 DMWARN_LIMIT("%s: any_congested: nonexistent device %s",
1529 dm_device_name(t->md),
1530 bdevname(dd->dm_dev.bdev, b));
1531 }
1532
1533 list_for_each_entry(cb, &t->target_callbacks, list)
1534 if (cb->congested_fn)
1535 r |= cb->congested_fn(cb, bdi_bits);
1536
1537 return r;
1538}
1539
1540int dm_table_any_busy_target(struct dm_table *t)
1541{
1542 unsigned i;
1543 struct dm_target *ti;
1544
1545 for (i = 0; i < t->num_targets; i++) {
1546 ti = t->targets + i;
1547 if (ti->type->busy && ti->type->busy(ti))
1548 return 1;
1549 }
1550
1551 return 0;
1552}
1553
1554struct mapped_device *dm_table_get_md(struct dm_table *t)
1555{
1556 return t->md;
1557}
1558EXPORT_SYMBOL(dm_table_get_md);
1559
1560static int device_discard_capable(struct dm_target *ti, struct dm_dev *dev,
1561 sector_t start, sector_t len, void *data)
1562{
1563 struct request_queue *q = bdev_get_queue(dev->bdev);
1564
1565 return q && blk_queue_discard(q);
1566}
1567
1568bool dm_table_supports_discards(struct dm_table *t)
1569{
1570 struct dm_target *ti;
1571 unsigned i = 0;
1572
1573 /*
1574 * Unless any target used by the table set discards_supported,
1575 * require at least one underlying device to support discards.
1576 * t->devices includes internal dm devices such as mirror logs
1577 * so we need to use iterate_devices here, which targets
1578 * supporting discard selectively must provide.
1579 */
1580 while (i < dm_table_get_num_targets(t)) {
1581 ti = dm_table_get_target(t, i++);
1582
1583 if (!ti->num_discard_requests)
1584 continue;
1585
1586 if (ti->discards_supported)
1587 return 1;
1588
1589 if (ti->type->iterate_devices &&
1590 ti->type->iterate_devices(ti, device_discard_capable, NULL))
1591 return 1;
1592 }
1593
1594 return 0;
1595}