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