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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
22#define DM_MSG_PREFIX "table"
23
24#define MAX_DEPTH 16
25#define NODE_SIZE L1_CACHE_BYTES
26#define KEYS_PER_NODE (NODE_SIZE / sizeof(sector_t))
27#define CHILDREN_PER_NODE (KEYS_PER_NODE + 1)
28
29/*
30 * The table has always exactly one reference from either mapped_device->map
31 * or hash_cell->new_map. This reference is not counted in table->holders.
32 * A pair of dm_create_table/dm_destroy_table functions is used for table
33 * creation/destruction.
34 *
35 * Temporary references from the other code increase table->holders. A pair
36 * of dm_table_get/dm_table_put functions is used to manipulate it.
37 *
38 * When the table is about to be destroyed, we wait for table->holders to
39 * drop to zero.
40 */
41
42struct dm_table {
43 struct mapped_device *md;
44 atomic_t holders;
45 unsigned type;
46
47 /* btree table */
48 unsigned int depth;
49 unsigned int counts[MAX_DEPTH]; /* in nodes */
50 sector_t *index[MAX_DEPTH];
51
52 unsigned int num_targets;
53 unsigned int num_allocated;
54 sector_t *highs;
55 struct dm_target *targets;
56
57 struct target_type *immutable_target_type;
58 unsigned integrity_supported:1;
59 unsigned singleton:1;
60
61 /*
62 * Indicates the rw permissions for the new logical
63 * device. This should be a combination of FMODE_READ
64 * and FMODE_WRITE.
65 */
66 fmode_t mode;
67
68 /* a list of devices used by this table */
69 struct list_head devices;
70
71 /* events get handed up using this callback */
72 void (*event_fn)(void *);
73 void *event_context;
74
75 struct dm_md_mempools *mempools;
76
77 struct list_head target_callbacks;
78};
79
80/*
81 * Similar to ceiling(log_size(n))
82 */
83static unsigned int int_log(unsigned int n, unsigned int base)
84{
85 int result = 0;
86
87 while (n > 1) {
88 n = dm_div_up(n, base);
89 result++;
90 }
91
92 return result;
93}
94
95/*
96 * Calculate the index of the child node of the n'th node k'th key.
97 */
98static inline unsigned int get_child(unsigned int n, unsigned int k)
99{
100 return (n * CHILDREN_PER_NODE) + k;
101}
102
103/*
104 * Return the n'th node of level l from table t.
105 */
106static inline sector_t *get_node(struct dm_table *t,
107 unsigned int l, unsigned int n)
108{
109 return t->index[l] + (n * KEYS_PER_NODE);
110}
111
112/*
113 * Return the highest key that you could lookup from the n'th
114 * node on level l of the btree.
115 */
116static sector_t high(struct dm_table *t, unsigned int l, unsigned int n)
117{
118 for (; l < t->depth - 1; l++)
119 n = get_child(n, CHILDREN_PER_NODE - 1);
120
121 if (n >= t->counts[l])
122 return (sector_t) - 1;
123
124 return get_node(t, l, n)[KEYS_PER_NODE - 1];
125}
126
127/*
128 * Fills in a level of the btree based on the highs of the level
129 * below it.
130 */
131static int setup_btree_index(unsigned int l, struct dm_table *t)
132{
133 unsigned int n, k;
134 sector_t *node;
135
136 for (n = 0U; n < t->counts[l]; n++) {
137 node = get_node(t, l, n);
138
139 for (k = 0U; k < KEYS_PER_NODE; k++)
140 node[k] = high(t, l + 1, get_child(n, k));
141 }
142
143 return 0;
144}
145
146void *dm_vcalloc(unsigned long nmemb, unsigned long elem_size)
147{
148 unsigned long size;
149 void *addr;
150
151 /*
152 * Check that we're not going to overflow.
153 */
154 if (nmemb > (ULONG_MAX / elem_size))
155 return NULL;
156
157 size = nmemb * elem_size;
158 addr = vzalloc(size);
159
160 return addr;
161}
162EXPORT_SYMBOL(dm_vcalloc);
163
164/*
165 * highs, and targets are managed as dynamic arrays during a
166 * table load.
167 */
168static int alloc_targets(struct dm_table *t, unsigned int num)
169{
170 sector_t *n_highs;
171 struct dm_target *n_targets;
172 int n = t->num_targets;
173
174 /*
175 * Allocate both the target array and offset array at once.
176 * Append an empty entry to catch sectors beyond the end of
177 * the device.
178 */
179 n_highs = (sector_t *) dm_vcalloc(num + 1, sizeof(struct dm_target) +
180 sizeof(sector_t));
181 if (!n_highs)
182 return -ENOMEM;
183
184 n_targets = (struct dm_target *) (n_highs + num);
185
186 if (n) {
187 memcpy(n_highs, t->highs, sizeof(*n_highs) * n);
188 memcpy(n_targets, t->targets, sizeof(*n_targets) * n);
189 }
190
191 memset(n_highs + n, -1, sizeof(*n_highs) * (num - n));
192 vfree(t->highs);
193
194 t->num_allocated = num;
195 t->highs = n_highs;
196 t->targets = n_targets;
197
198 return 0;
199}
200
201int dm_table_create(struct dm_table **result, fmode_t mode,
202 unsigned num_targets, struct mapped_device *md)
203{
204 struct dm_table *t = kzalloc(sizeof(*t), GFP_KERNEL);
205
206 if (!t)
207 return -ENOMEM;
208
209 INIT_LIST_HEAD(&t->devices);
210 INIT_LIST_HEAD(&t->target_callbacks);
211 atomic_set(&t->holders, 0);
212
213 if (!num_targets)
214 num_targets = KEYS_PER_NODE;
215
216 num_targets = dm_round_up(num_targets, KEYS_PER_NODE);
217
218 if (alloc_targets(t, num_targets)) {
219 kfree(t);
220 t = NULL;
221 return -ENOMEM;
222 }
223
224 t->mode = mode;
225 t->md = md;
226 *result = t;
227 return 0;
228}
229
230static void free_devices(struct list_head *devices)
231{
232 struct list_head *tmp, *next;
233
234 list_for_each_safe(tmp, next, devices) {
235 struct dm_dev_internal *dd =
236 list_entry(tmp, struct dm_dev_internal, list);
237 DMWARN("dm_table_destroy: dm_put_device call missing for %s",
238 dd->dm_dev.name);
239 kfree(dd);
240 }
241}
242
243void dm_table_destroy(struct dm_table *t)
244{
245 unsigned int i;
246
247 if (!t)
248 return;
249
250 while (atomic_read(&t->holders))
251 msleep(1);
252 smp_mb();
253
254 /* free the indexes */
255 if (t->depth >= 2)
256 vfree(t->index[t->depth - 2]);
257
258 /* free the targets */
259 for (i = 0; i < t->num_targets; i++) {
260 struct dm_target *tgt = t->targets + i;
261
262 if (tgt->type->dtr)
263 tgt->type->dtr(tgt);
264
265 dm_put_target_type(tgt->type);
266 }
267
268 vfree(t->highs);
269
270 /* free the device list */
271 free_devices(&t->devices);
272
273 dm_free_md_mempools(t->mempools);
274
275 kfree(t);
276}
277
278void dm_table_get(struct dm_table *t)
279{
280 atomic_inc(&t->holders);
281}
282EXPORT_SYMBOL(dm_table_get);
283
284void dm_table_put(struct dm_table *t)
285{
286 if (!t)
287 return;
288
289 smp_mb__before_atomic_dec();
290 atomic_dec(&t->holders);
291}
292EXPORT_SYMBOL(dm_table_put);
293
294/*
295 * Checks to see if we need to extend highs or targets.
296 */
297static inline int check_space(struct dm_table *t)
298{
299 if (t->num_targets >= t->num_allocated)
300 return alloc_targets(t, t->num_allocated * 2);
301
302 return 0;
303}
304
305/*
306 * See if we've already got a device in the list.
307 */
308static struct dm_dev_internal *find_device(struct list_head *l, dev_t dev)
309{
310 struct dm_dev_internal *dd;
311
312 list_for_each_entry (dd, l, list)
313 if (dd->dm_dev.bdev->bd_dev == dev)
314 return dd;
315
316 return NULL;
317}
318
319/*
320 * Open a device so we can use it as a map destination.
321 */
322static int open_dev(struct dm_dev_internal *d, dev_t dev,
323 struct mapped_device *md)
324{
325 static char *_claim_ptr = "I belong to device-mapper";
326 struct block_device *bdev;
327
328 int r;
329
330 BUG_ON(d->dm_dev.bdev);
331
332 bdev = blkdev_get_by_dev(dev, d->dm_dev.mode | FMODE_EXCL, _claim_ptr);
333 if (IS_ERR(bdev))
334 return PTR_ERR(bdev);
335
336 r = bd_link_disk_holder(bdev, dm_disk(md));
337 if (r) {
338 blkdev_put(bdev, d->dm_dev.mode | FMODE_EXCL);
339 return r;
340 }
341
342 d->dm_dev.bdev = bdev;
343 return 0;
344}
345
346/*
347 * Close a device that we've been using.
348 */
349static void close_dev(struct dm_dev_internal *d, struct mapped_device *md)
350{
351 if (!d->dm_dev.bdev)
352 return;
353
354 bd_unlink_disk_holder(d->dm_dev.bdev, dm_disk(md));
355 blkdev_put(d->dm_dev.bdev, d->dm_dev.mode | FMODE_EXCL);
356 d->dm_dev.bdev = NULL;
357}
358
359/*
360 * If possible, this checks an area of a destination device is invalid.
361 */
362static int device_area_is_invalid(struct dm_target *ti, struct dm_dev *dev,
363 sector_t start, sector_t len, void *data)
364{
365 struct request_queue *q;
366 struct queue_limits *limits = data;
367 struct block_device *bdev = dev->bdev;
368 sector_t dev_size =
369 i_size_read(bdev->bd_inode) >> SECTOR_SHIFT;
370 unsigned short logical_block_size_sectors =
371 limits->logical_block_size >> SECTOR_SHIFT;
372 char b[BDEVNAME_SIZE];
373
374 /*
375 * Some devices exist without request functions,
376 * such as loop devices not yet bound to backing files.
377 * Forbid the use of such devices.
378 */
379 q = bdev_get_queue(bdev);
380 if (!q || !q->make_request_fn) {
381 DMWARN("%s: %s is not yet initialised: "
382 "start=%llu, len=%llu, dev_size=%llu",
383 dm_device_name(ti->table->md), bdevname(bdev, b),
384 (unsigned long long)start,
385 (unsigned long long)len,
386 (unsigned long long)dev_size);
387 return 1;
388 }
389
390 if (!dev_size)
391 return 0;
392
393 if ((start >= dev_size) || (start + len > dev_size)) {
394 DMWARN("%s: %s too small for target: "
395 "start=%llu, len=%llu, dev_size=%llu",
396 dm_device_name(ti->table->md), bdevname(bdev, b),
397 (unsigned long long)start,
398 (unsigned long long)len,
399 (unsigned long long)dev_size);
400 return 1;
401 }
402
403 if (logical_block_size_sectors <= 1)
404 return 0;
405
406 if (start & (logical_block_size_sectors - 1)) {
407 DMWARN("%s: start=%llu not aligned to h/w "
408 "logical block size %u of %s",
409 dm_device_name(ti->table->md),
410 (unsigned long long)start,
411 limits->logical_block_size, bdevname(bdev, b));
412 return 1;
413 }
414
415 if (len & (logical_block_size_sectors - 1)) {
416 DMWARN("%s: len=%llu not aligned to h/w "
417 "logical block size %u of %s",
418 dm_device_name(ti->table->md),
419 (unsigned long long)len,
420 limits->logical_block_size, bdevname(bdev, b));
421 return 1;
422 }
423
424 return 0;
425}
426
427/*
428 * This upgrades the mode on an already open dm_dev, being
429 * careful to leave things as they were if we fail to reopen the
430 * device and not to touch the existing bdev field in case
431 * it is accessed concurrently inside dm_table_any_congested().
432 */
433static int upgrade_mode(struct dm_dev_internal *dd, fmode_t new_mode,
434 struct mapped_device *md)
435{
436 int r;
437 struct dm_dev_internal dd_new, dd_old;
438
439 dd_new = dd_old = *dd;
440
441 dd_new.dm_dev.mode |= new_mode;
442 dd_new.dm_dev.bdev = NULL;
443
444 r = open_dev(&dd_new, dd->dm_dev.bdev->bd_dev, md);
445 if (r)
446 return r;
447
448 dd->dm_dev.mode |= new_mode;
449 close_dev(&dd_old, md);
450
451 return 0;
452}
453
454/*
455 * Add a device to the list, or just increment the usage count if
456 * it's already present.
457 */
458int dm_get_device(struct dm_target *ti, const char *path, fmode_t mode,
459 struct dm_dev **result)
460{
461 int r;
462 dev_t uninitialized_var(dev);
463 struct dm_dev_internal *dd;
464 unsigned int major, minor;
465 struct dm_table *t = ti->table;
466 char dummy;
467
468 BUG_ON(!t);
469
470 if (sscanf(path, "%u:%u%c", &major, &minor, &dummy) == 2) {
471 /* Extract the major/minor numbers */
472 dev = MKDEV(major, minor);
473 if (MAJOR(dev) != major || MINOR(dev) != minor)
474 return -EOVERFLOW;
475 } else {
476 /* convert the path to a device */
477 struct block_device *bdev = lookup_bdev(path);
478
479 if (IS_ERR(bdev))
480 return PTR_ERR(bdev);
481 dev = bdev->bd_dev;
482 bdput(bdev);
483 }
484
485 dd = find_device(&t->devices, dev);
486 if (!dd) {
487 dd = kmalloc(sizeof(*dd), GFP_KERNEL);
488 if (!dd)
489 return -ENOMEM;
490
491 dd->dm_dev.mode = mode;
492 dd->dm_dev.bdev = NULL;
493
494 if ((r = open_dev(dd, dev, t->md))) {
495 kfree(dd);
496 return r;
497 }
498
499 format_dev_t(dd->dm_dev.name, dev);
500
501 atomic_set(&dd->count, 0);
502 list_add(&dd->list, &t->devices);
503
504 } else if (dd->dm_dev.mode != (mode | dd->dm_dev.mode)) {
505 r = upgrade_mode(dd, mode, t->md);
506 if (r)
507 return r;
508 }
509 atomic_inc(&dd->count);
510
511 *result = &dd->dm_dev;
512 return 0;
513}
514EXPORT_SYMBOL(dm_get_device);
515
516int dm_set_device_limits(struct dm_target *ti, struct dm_dev *dev,
517 sector_t start, sector_t len, void *data)
518{
519 struct queue_limits *limits = data;
520 struct block_device *bdev = dev->bdev;
521 struct request_queue *q = bdev_get_queue(bdev);
522 char b[BDEVNAME_SIZE];
523
524 if (unlikely(!q)) {
525 DMWARN("%s: Cannot set limits for nonexistent device %s",
526 dm_device_name(ti->table->md), bdevname(bdev, b));
527 return 0;
528 }
529
530 if (bdev_stack_limits(limits, bdev, start) < 0)
531 DMWARN("%s: adding target device %s caused an alignment inconsistency: "
532 "physical_block_size=%u, logical_block_size=%u, "
533 "alignment_offset=%u, start=%llu",
534 dm_device_name(ti->table->md), bdevname(bdev, b),
535 q->limits.physical_block_size,
536 q->limits.logical_block_size,
537 q->limits.alignment_offset,
538 (unsigned long long) start << SECTOR_SHIFT);
539
540 /*
541 * Check if merge fn is supported.
542 * If not we'll force DM to use PAGE_SIZE or
543 * smaller I/O, just to be safe.
544 */
545 if (dm_queue_merge_is_compulsory(q) && !ti->type->merge)
546 blk_limits_max_hw_sectors(limits,
547 (unsigned int) (PAGE_SIZE >> 9));
548 return 0;
549}
550EXPORT_SYMBOL_GPL(dm_set_device_limits);
551
552/*
553 * Decrement a device's use count and remove it if necessary.
554 */
555void dm_put_device(struct dm_target *ti, struct dm_dev *d)
556{
557 struct dm_dev_internal *dd = container_of(d, struct dm_dev_internal,
558 dm_dev);
559
560 if (atomic_dec_and_test(&dd->count)) {
561 close_dev(dd, ti->table->md);
562 list_del(&dd->list);
563 kfree(dd);
564 }
565}
566EXPORT_SYMBOL(dm_put_device);
567
568/*
569 * Checks to see if the target joins onto the end of the table.
570 */
571static int adjoin(struct dm_table *table, struct dm_target *ti)
572{
573 struct dm_target *prev;
574
575 if (!table->num_targets)
576 return !ti->begin;
577
578 prev = &table->targets[table->num_targets - 1];
579 return (ti->begin == (prev->begin + prev->len));
580}
581
582/*
583 * Used to dynamically allocate the arg array.
584 */
585static char **realloc_argv(unsigned *array_size, char **old_argv)
586{
587 char **argv;
588 unsigned new_size;
589
590 new_size = *array_size ? *array_size * 2 : 64;
591 argv = kmalloc(new_size * sizeof(*argv), GFP_KERNEL);
592 if (argv) {
593 memcpy(argv, old_argv, *array_size * sizeof(*argv));
594 *array_size = new_size;
595 }
596
597 kfree(old_argv);
598 return argv;
599}
600
601/*
602 * Destructively splits up the argument list to pass to ctr.
603 */
604int dm_split_args(int *argc, char ***argvp, char *input)
605{
606 char *start, *end = input, *out, **argv = NULL;
607 unsigned array_size = 0;
608
609 *argc = 0;
610
611 if (!input) {
612 *argvp = NULL;
613 return 0;
614 }
615
616 argv = realloc_argv(&array_size, argv);
617 if (!argv)
618 return -ENOMEM;
619
620 while (1) {
621 /* Skip whitespace */
622 start = skip_spaces(end);
623
624 if (!*start)
625 break; /* success, we hit the end */
626
627 /* 'out' is used to remove any back-quotes */
628 end = out = start;
629 while (*end) {
630 /* Everything apart from '\0' can be quoted */
631 if (*end == '\\' && *(end + 1)) {
632 *out++ = *(end + 1);
633 end += 2;
634 continue;
635 }
636
637 if (isspace(*end))
638 break; /* end of token */
639
640 *out++ = *end++;
641 }
642
643 /* have we already filled the array ? */
644 if ((*argc + 1) > array_size) {
645 argv = realloc_argv(&array_size, argv);
646 if (!argv)
647 return -ENOMEM;
648 }
649
650 /* we know this is whitespace */
651 if (*end)
652 end++;
653
654 /* terminate the string and put it in the array */
655 *out = '\0';
656 argv[*argc] = start;
657 (*argc)++;
658 }
659
660 *argvp = argv;
661 return 0;
662}
663
664/*
665 * Impose necessary and sufficient conditions on a devices's table such
666 * that any incoming bio which respects its logical_block_size can be
667 * processed successfully. If it falls across the boundary between
668 * two or more targets, the size of each piece it gets split into must
669 * be compatible with the logical_block_size of the target processing it.
670 */
671static int validate_hardware_logical_block_alignment(struct dm_table *table,
672 struct queue_limits *limits)
673{
674 /*
675 * This function uses arithmetic modulo the logical_block_size
676 * (in units of 512-byte sectors).
677 */
678 unsigned short device_logical_block_size_sects =
679 limits->logical_block_size >> SECTOR_SHIFT;
680
681 /*
682 * Offset of the start of the next table entry, mod logical_block_size.
683 */
684 unsigned short next_target_start = 0;
685
686 /*
687 * Given an aligned bio that extends beyond the end of a
688 * target, how many sectors must the next target handle?
689 */
690 unsigned short remaining = 0;
691
692 struct dm_target *uninitialized_var(ti);
693 struct queue_limits ti_limits;
694 unsigned i = 0;
695
696 /*
697 * Check each entry in the table in turn.
698 */
699 while (i < dm_table_get_num_targets(table)) {
700 ti = dm_table_get_target(table, i++);
701
702 blk_set_stacking_limits(&ti_limits);
703
704 /* combine all target devices' limits */
705 if (ti->type->iterate_devices)
706 ti->type->iterate_devices(ti, dm_set_device_limits,
707 &ti_limits);
708
709 /*
710 * If the remaining sectors fall entirely within this
711 * table entry are they compatible with its logical_block_size?
712 */
713 if (remaining < ti->len &&
714 remaining & ((ti_limits.logical_block_size >>
715 SECTOR_SHIFT) - 1))
716 break; /* Error */
717
718 next_target_start =
719 (unsigned short) ((next_target_start + ti->len) &
720 (device_logical_block_size_sects - 1));
721 remaining = next_target_start ?
722 device_logical_block_size_sects - next_target_start : 0;
723 }
724
725 if (remaining) {
726 DMWARN("%s: table line %u (start sect %llu len %llu) "
727 "not aligned to h/w logical block size %u",
728 dm_device_name(table->md), i,
729 (unsigned long long) ti->begin,
730 (unsigned long long) ti->len,
731 limits->logical_block_size);
732 return -EINVAL;
733 }
734
735 return 0;
736}
737
738int dm_table_add_target(struct dm_table *t, const char *type,
739 sector_t start, sector_t len, char *params)
740{
741 int r = -EINVAL, argc;
742 char **argv;
743 struct dm_target *tgt;
744
745 if (t->singleton) {
746 DMERR("%s: target type %s must appear alone in table",
747 dm_device_name(t->md), t->targets->type->name);
748 return -EINVAL;
749 }
750
751 if ((r = check_space(t)))
752 return r;
753
754 tgt = t->targets + t->num_targets;
755 memset(tgt, 0, sizeof(*tgt));
756
757 if (!len) {
758 DMERR("%s: zero-length target", dm_device_name(t->md));
759 return -EINVAL;
760 }
761
762 tgt->type = dm_get_target_type(type);
763 if (!tgt->type) {
764 DMERR("%s: %s: unknown target type", dm_device_name(t->md),
765 type);
766 return -EINVAL;
767 }
768
769 if (dm_target_needs_singleton(tgt->type)) {
770 if (t->num_targets) {
771 DMERR("%s: target type %s must appear alone in table",
772 dm_device_name(t->md), type);
773 return -EINVAL;
774 }
775 t->singleton = 1;
776 }
777
778 if (dm_target_always_writeable(tgt->type) && !(t->mode & FMODE_WRITE)) {
779 DMERR("%s: target type %s may not be included in read-only tables",
780 dm_device_name(t->md), type);
781 return -EINVAL;
782 }
783
784 if (t->immutable_target_type) {
785 if (t->immutable_target_type != tgt->type) {
786 DMERR("%s: immutable target type %s cannot be mixed with other target types",
787 dm_device_name(t->md), t->immutable_target_type->name);
788 return -EINVAL;
789 }
790 } else if (dm_target_is_immutable(tgt->type)) {
791 if (t->num_targets) {
792 DMERR("%s: immutable target type %s cannot be mixed with other target types",
793 dm_device_name(t->md), tgt->type->name);
794 return -EINVAL;
795 }
796 t->immutable_target_type = tgt->type;
797 }
798
799 tgt->table = t;
800 tgt->begin = start;
801 tgt->len = len;
802 tgt->error = "Unknown error";
803
804 /*
805 * Does this target adjoin the previous one ?
806 */
807 if (!adjoin(t, tgt)) {
808 tgt->error = "Gap in table";
809 r = -EINVAL;
810 goto bad;
811 }
812
813 r = dm_split_args(&argc, &argv, params);
814 if (r) {
815 tgt->error = "couldn't split parameters (insufficient memory)";
816 goto bad;
817 }
818
819 r = tgt->type->ctr(tgt, argc, argv);
820 kfree(argv);
821 if (r)
822 goto bad;
823
824 t->highs[t->num_targets++] = tgt->begin + tgt->len - 1;
825
826 if (!tgt->num_discard_requests && tgt->discards_supported)
827 DMWARN("%s: %s: ignoring discards_supported because num_discard_requests is zero.",
828 dm_device_name(t->md), type);
829
830 return 0;
831
832 bad:
833 DMERR("%s: %s: %s", dm_device_name(t->md), type, tgt->error);
834 dm_put_target_type(tgt->type);
835 return r;
836}
837
838/*
839 * Target argument parsing helpers.
840 */
841static int validate_next_arg(struct dm_arg *arg, struct dm_arg_set *arg_set,
842 unsigned *value, char **error, unsigned grouped)
843{
844 const char *arg_str = dm_shift_arg(arg_set);
845 char dummy;
846
847 if (!arg_str ||
848 (sscanf(arg_str, "%u%c", value, &dummy) != 1) ||
849 (*value < arg->min) ||
850 (*value > arg->max) ||
851 (grouped && arg_set->argc < *value)) {
852 *error = arg->error;
853 return -EINVAL;
854 }
855
856 return 0;
857}
858
859int dm_read_arg(struct dm_arg *arg, struct dm_arg_set *arg_set,
860 unsigned *value, char **error)
861{
862 return validate_next_arg(arg, arg_set, value, error, 0);
863}
864EXPORT_SYMBOL(dm_read_arg);
865
866int dm_read_arg_group(struct dm_arg *arg, struct dm_arg_set *arg_set,
867 unsigned *value, char **error)
868{
869 return validate_next_arg(arg, arg_set, value, error, 1);
870}
871EXPORT_SYMBOL(dm_read_arg_group);
872
873const char *dm_shift_arg(struct dm_arg_set *as)
874{
875 char *r;
876
877 if (as->argc) {
878 as->argc--;
879 r = *as->argv;
880 as->argv++;
881 return r;
882 }
883
884 return NULL;
885}
886EXPORT_SYMBOL(dm_shift_arg);
887
888void dm_consume_args(struct dm_arg_set *as, unsigned num_args)
889{
890 BUG_ON(as->argc < num_args);
891 as->argc -= num_args;
892 as->argv += num_args;
893}
894EXPORT_SYMBOL(dm_consume_args);
895
896static int dm_table_set_type(struct dm_table *t)
897{
898 unsigned i;
899 unsigned bio_based = 0, request_based = 0;
900 struct dm_target *tgt;
901 struct dm_dev_internal *dd;
902 struct list_head *devices;
903
904 for (i = 0; i < t->num_targets; i++) {
905 tgt = t->targets + i;
906 if (dm_target_request_based(tgt))
907 request_based = 1;
908 else
909 bio_based = 1;
910
911 if (bio_based && request_based) {
912 DMWARN("Inconsistent table: different target types"
913 " can't be mixed up");
914 return -EINVAL;
915 }
916 }
917
918 if (bio_based) {
919 /* We must use this table as bio-based */
920 t->type = DM_TYPE_BIO_BASED;
921 return 0;
922 }
923
924 BUG_ON(!request_based); /* No targets in this table */
925
926 /* Non-request-stackable devices can't be used for request-based dm */
927 devices = dm_table_get_devices(t);
928 list_for_each_entry(dd, devices, list) {
929 if (!blk_queue_stackable(bdev_get_queue(dd->dm_dev.bdev))) {
930 DMWARN("table load rejected: including"
931 " non-request-stackable devices");
932 return -EINVAL;
933 }
934 }
935
936 /*
937 * Request-based dm supports only tables that have a single target now.
938 * To support multiple targets, request splitting support is needed,
939 * and that needs lots of changes in the block-layer.
940 * (e.g. request completion process for partial completion.)
941 */
942 if (t->num_targets > 1) {
943 DMWARN("Request-based dm doesn't support multiple targets yet");
944 return -EINVAL;
945 }
946
947 t->type = DM_TYPE_REQUEST_BASED;
948
949 return 0;
950}
951
952unsigned dm_table_get_type(struct dm_table *t)
953{
954 return t->type;
955}
956
957struct target_type *dm_table_get_immutable_target_type(struct dm_table *t)
958{
959 return t->immutable_target_type;
960}
961
962bool dm_table_request_based(struct dm_table *t)
963{
964 return dm_table_get_type(t) == DM_TYPE_REQUEST_BASED;
965}
966
967int dm_table_alloc_md_mempools(struct dm_table *t)
968{
969 unsigned type = dm_table_get_type(t);
970
971 if (unlikely(type == DM_TYPE_NONE)) {
972 DMWARN("no table type is set, can't allocate mempools");
973 return -EINVAL;
974 }
975
976 t->mempools = dm_alloc_md_mempools(type, t->integrity_supported);
977 if (!t->mempools)
978 return -ENOMEM;
979
980 return 0;
981}
982
983void dm_table_free_md_mempools(struct dm_table *t)
984{
985 dm_free_md_mempools(t->mempools);
986 t->mempools = NULL;
987}
988
989struct dm_md_mempools *dm_table_get_md_mempools(struct dm_table *t)
990{
991 return t->mempools;
992}
993
994static int setup_indexes(struct dm_table *t)
995{
996 int i;
997 unsigned int total = 0;
998 sector_t *indexes;
999
1000 /* allocate the space for *all* the indexes */
1001 for (i = t->depth - 2; i >= 0; i--) {
1002 t->counts[i] = dm_div_up(t->counts[i + 1], CHILDREN_PER_NODE);
1003 total += t->counts[i];
1004 }
1005
1006 indexes = (sector_t *) dm_vcalloc(total, (unsigned long) NODE_SIZE);
1007 if (!indexes)
1008 return -ENOMEM;
1009
1010 /* set up internal nodes, bottom-up */
1011 for (i = t->depth - 2; i >= 0; i--) {
1012 t->index[i] = indexes;
1013 indexes += (KEYS_PER_NODE * t->counts[i]);
1014 setup_btree_index(i, t);
1015 }
1016
1017 return 0;
1018}
1019
1020/*
1021 * Builds the btree to index the map.
1022 */
1023static int dm_table_build_index(struct dm_table *t)
1024{
1025 int r = 0;
1026 unsigned int leaf_nodes;
1027
1028 /* how many indexes will the btree have ? */
1029 leaf_nodes = dm_div_up(t->num_targets, KEYS_PER_NODE);
1030 t->depth = 1 + int_log(leaf_nodes, CHILDREN_PER_NODE);
1031
1032 /* leaf layer has already been set up */
1033 t->counts[t->depth - 1] = leaf_nodes;
1034 t->index[t->depth - 1] = t->highs;
1035
1036 if (t->depth >= 2)
1037 r = setup_indexes(t);
1038
1039 return r;
1040}
1041
1042/*
1043 * Get a disk whose integrity profile reflects the table's profile.
1044 * If %match_all is true, all devices' profiles must match.
1045 * If %match_all is false, all devices must at least have an
1046 * allocated integrity profile; but uninitialized is ok.
1047 * Returns NULL if integrity support was inconsistent or unavailable.
1048 */
1049static struct gendisk * dm_table_get_integrity_disk(struct dm_table *t,
1050 bool match_all)
1051{
1052 struct list_head *devices = dm_table_get_devices(t);
1053 struct dm_dev_internal *dd = NULL;
1054 struct gendisk *prev_disk = NULL, *template_disk = NULL;
1055
1056 list_for_each_entry(dd, devices, list) {
1057 template_disk = dd->dm_dev.bdev->bd_disk;
1058 if (!blk_get_integrity(template_disk))
1059 goto no_integrity;
1060 if (!match_all && !blk_integrity_is_initialized(template_disk))
1061 continue; /* skip uninitialized profiles */
1062 else if (prev_disk &&
1063 blk_integrity_compare(prev_disk, template_disk) < 0)
1064 goto no_integrity;
1065 prev_disk = template_disk;
1066 }
1067
1068 return template_disk;
1069
1070no_integrity:
1071 if (prev_disk)
1072 DMWARN("%s: integrity not set: %s and %s profile mismatch",
1073 dm_device_name(t->md),
1074 prev_disk->disk_name,
1075 template_disk->disk_name);
1076 return NULL;
1077}
1078
1079/*
1080 * Register the mapped device for blk_integrity support if
1081 * the underlying devices have an integrity profile. But all devices
1082 * may not have matching profiles (checking all devices isn't reliable
1083 * during table load because this table may use other DM device(s) which
1084 * must be resumed before they will have an initialized integity profile).
1085 * Stacked DM devices force a 2 stage integrity profile validation:
1086 * 1 - during load, validate all initialized integrity profiles match
1087 * 2 - during resume, validate all integrity profiles match
1088 */
1089static int dm_table_prealloc_integrity(struct dm_table *t, struct mapped_device *md)
1090{
1091 struct gendisk *template_disk = NULL;
1092
1093 template_disk = dm_table_get_integrity_disk(t, false);
1094 if (!template_disk)
1095 return 0;
1096
1097 if (!blk_integrity_is_initialized(dm_disk(md))) {
1098 t->integrity_supported = 1;
1099 return blk_integrity_register(dm_disk(md), NULL);
1100 }
1101
1102 /*
1103 * If DM device already has an initalized integrity
1104 * profile the new profile should not conflict.
1105 */
1106 if (blk_integrity_is_initialized(template_disk) &&
1107 blk_integrity_compare(dm_disk(md), template_disk) < 0) {
1108 DMWARN("%s: conflict with existing integrity profile: "
1109 "%s profile mismatch",
1110 dm_device_name(t->md),
1111 template_disk->disk_name);
1112 return 1;
1113 }
1114
1115 /* Preserve existing initialized integrity profile */
1116 t->integrity_supported = 1;
1117 return 0;
1118}
1119
1120/*
1121 * Prepares the table for use by building the indices,
1122 * setting the type, and allocating mempools.
1123 */
1124int dm_table_complete(struct dm_table *t)
1125{
1126 int r;
1127
1128 r = dm_table_set_type(t);
1129 if (r) {
1130 DMERR("unable to set table type");
1131 return r;
1132 }
1133
1134 r = dm_table_build_index(t);
1135 if (r) {
1136 DMERR("unable to build btrees");
1137 return r;
1138 }
1139
1140 r = dm_table_prealloc_integrity(t, t->md);
1141 if (r) {
1142 DMERR("could not register integrity profile.");
1143 return r;
1144 }
1145
1146 r = dm_table_alloc_md_mempools(t);
1147 if (r)
1148 DMERR("unable to allocate mempools");
1149
1150 return r;
1151}
1152
1153static DEFINE_MUTEX(_event_lock);
1154void dm_table_event_callback(struct dm_table *t,
1155 void (*fn)(void *), void *context)
1156{
1157 mutex_lock(&_event_lock);
1158 t->event_fn = fn;
1159 t->event_context = context;
1160 mutex_unlock(&_event_lock);
1161}
1162
1163void dm_table_event(struct dm_table *t)
1164{
1165 /*
1166 * You can no longer call dm_table_event() from interrupt
1167 * context, use a bottom half instead.
1168 */
1169 BUG_ON(in_interrupt());
1170
1171 mutex_lock(&_event_lock);
1172 if (t->event_fn)
1173 t->event_fn(t->event_context);
1174 mutex_unlock(&_event_lock);
1175}
1176EXPORT_SYMBOL(dm_table_event);
1177
1178sector_t dm_table_get_size(struct dm_table *t)
1179{
1180 return t->num_targets ? (t->highs[t->num_targets - 1] + 1) : 0;
1181}
1182EXPORT_SYMBOL(dm_table_get_size);
1183
1184struct dm_target *dm_table_get_target(struct dm_table *t, unsigned int index)
1185{
1186 if (index >= t->num_targets)
1187 return NULL;
1188
1189 return t->targets + index;
1190}
1191
1192/*
1193 * Search the btree for the correct target.
1194 *
1195 * Caller should check returned pointer with dm_target_is_valid()
1196 * to trap I/O beyond end of device.
1197 */
1198struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector)
1199{
1200 unsigned int l, n = 0, k = 0;
1201 sector_t *node;
1202
1203 for (l = 0; l < t->depth; l++) {
1204 n = get_child(n, k);
1205 node = get_node(t, l, n);
1206
1207 for (k = 0; k < KEYS_PER_NODE; k++)
1208 if (node[k] >= sector)
1209 break;
1210 }
1211
1212 return &t->targets[(KEYS_PER_NODE * n) + k];
1213}
1214
1215/*
1216 * Establish the new table's queue_limits and validate them.
1217 */
1218int dm_calculate_queue_limits(struct dm_table *table,
1219 struct queue_limits *limits)
1220{
1221 struct dm_target *uninitialized_var(ti);
1222 struct queue_limits ti_limits;
1223 unsigned i = 0;
1224
1225 blk_set_stacking_limits(limits);
1226
1227 while (i < dm_table_get_num_targets(table)) {
1228 blk_set_stacking_limits(&ti_limits);
1229
1230 ti = dm_table_get_target(table, i++);
1231
1232 if (!ti->type->iterate_devices)
1233 goto combine_limits;
1234
1235 /*
1236 * Combine queue limits of all the devices this target uses.
1237 */
1238 ti->type->iterate_devices(ti, dm_set_device_limits,
1239 &ti_limits);
1240
1241 /* Set I/O hints portion of queue limits */
1242 if (ti->type->io_hints)
1243 ti->type->io_hints(ti, &ti_limits);
1244
1245 /*
1246 * Check each device area is consistent with the target's
1247 * overall queue limits.
1248 */
1249 if (ti->type->iterate_devices(ti, device_area_is_invalid,
1250 &ti_limits))
1251 return -EINVAL;
1252
1253combine_limits:
1254 /*
1255 * Merge this target's queue limits into the overall limits
1256 * for the table.
1257 */
1258 if (blk_stack_limits(limits, &ti_limits, 0) < 0)
1259 DMWARN("%s: adding target device "
1260 "(start sect %llu len %llu) "
1261 "caused an alignment inconsistency",
1262 dm_device_name(table->md),
1263 (unsigned long long) ti->begin,
1264 (unsigned long long) ti->len);
1265 }
1266
1267 return validate_hardware_logical_block_alignment(table, limits);
1268}
1269
1270/*
1271 * Set the integrity profile for this device if all devices used have
1272 * matching profiles. We're quite deep in the resume path but still
1273 * don't know if all devices (particularly DM devices this device
1274 * may be stacked on) have matching profiles. Even if the profiles
1275 * don't match we have no way to fail (to resume) at this point.
1276 */
1277static void dm_table_set_integrity(struct dm_table *t)
1278{
1279 struct gendisk *template_disk = NULL;
1280
1281 if (!blk_get_integrity(dm_disk(t->md)))
1282 return;
1283
1284 template_disk = dm_table_get_integrity_disk(t, true);
1285 if (template_disk)
1286 blk_integrity_register(dm_disk(t->md),
1287 blk_get_integrity(template_disk));
1288 else if (blk_integrity_is_initialized(dm_disk(t->md)))
1289 DMWARN("%s: device no longer has a valid integrity profile",
1290 dm_device_name(t->md));
1291 else
1292 DMWARN("%s: unable to establish an integrity profile",
1293 dm_device_name(t->md));
1294}
1295
1296static int device_flush_capable(struct dm_target *ti, struct dm_dev *dev,
1297 sector_t start, sector_t len, void *data)
1298{
1299 unsigned flush = (*(unsigned *)data);
1300 struct request_queue *q = bdev_get_queue(dev->bdev);
1301
1302 return q && (q->flush_flags & flush);
1303}
1304
1305static bool dm_table_supports_flush(struct dm_table *t, unsigned flush)
1306{
1307 struct dm_target *ti;
1308 unsigned i = 0;
1309
1310 /*
1311 * Require at least one underlying device to support flushes.
1312 * t->devices includes internal dm devices such as mirror logs
1313 * so we need to use iterate_devices here, which targets
1314 * supporting flushes must provide.
1315 */
1316 while (i < dm_table_get_num_targets(t)) {
1317 ti = dm_table_get_target(t, i++);
1318
1319 if (!ti->num_flush_requests)
1320 continue;
1321
1322 if (ti->type->iterate_devices &&
1323 ti->type->iterate_devices(ti, device_flush_capable, &flush))
1324 return 1;
1325 }
1326
1327 return 0;
1328}
1329
1330static bool dm_table_discard_zeroes_data(struct dm_table *t)
1331{
1332 struct dm_target *ti;
1333 unsigned i = 0;
1334
1335 /* Ensure that all targets supports discard_zeroes_data. */
1336 while (i < dm_table_get_num_targets(t)) {
1337 ti = dm_table_get_target(t, i++);
1338
1339 if (ti->discard_zeroes_data_unsupported)
1340 return 0;
1341 }
1342
1343 return 1;
1344}
1345
1346static int device_is_nonrot(struct dm_target *ti, struct dm_dev *dev,
1347 sector_t start, sector_t len, void *data)
1348{
1349 struct request_queue *q = bdev_get_queue(dev->bdev);
1350
1351 return q && blk_queue_nonrot(q);
1352}
1353
1354static int device_is_not_random(struct dm_target *ti, struct dm_dev *dev,
1355 sector_t start, sector_t len, void *data)
1356{
1357 struct request_queue *q = bdev_get_queue(dev->bdev);
1358
1359 return q && !blk_queue_add_random(q);
1360}
1361
1362static bool dm_table_all_devices_attribute(struct dm_table *t,
1363 iterate_devices_callout_fn func)
1364{
1365 struct dm_target *ti;
1366 unsigned i = 0;
1367
1368 while (i < dm_table_get_num_targets(t)) {
1369 ti = dm_table_get_target(t, i++);
1370
1371 if (!ti->type->iterate_devices ||
1372 !ti->type->iterate_devices(ti, func, NULL))
1373 return 0;
1374 }
1375
1376 return 1;
1377}
1378
1379void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
1380 struct queue_limits *limits)
1381{
1382 unsigned flush = 0;
1383
1384 /*
1385 * Copy table's limits to the DM device's request_queue
1386 */
1387 q->limits = *limits;
1388
1389 if (!dm_table_supports_discards(t))
1390 queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, q);
1391 else
1392 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q);
1393
1394 if (dm_table_supports_flush(t, REQ_FLUSH)) {
1395 flush |= REQ_FLUSH;
1396 if (dm_table_supports_flush(t, REQ_FUA))
1397 flush |= REQ_FUA;
1398 }
1399 blk_queue_flush(q, flush);
1400
1401 if (!dm_table_discard_zeroes_data(t))
1402 q->limits.discard_zeroes_data = 0;
1403
1404 /* Ensure that all underlying devices are non-rotational. */
1405 if (dm_table_all_devices_attribute(t, device_is_nonrot))
1406 queue_flag_set_unlocked(QUEUE_FLAG_NONROT, q);
1407 else
1408 queue_flag_clear_unlocked(QUEUE_FLAG_NONROT, q);
1409
1410 dm_table_set_integrity(t);
1411
1412 /*
1413 * Determine whether or not this queue's I/O timings contribute
1414 * to the entropy pool, Only request-based targets use this.
1415 * Clear QUEUE_FLAG_ADD_RANDOM if any underlying device does not
1416 * have it set.
1417 */
1418 if (blk_queue_add_random(q) && dm_table_all_devices_attribute(t, device_is_not_random))
1419 queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, q);
1420
1421 /*
1422 * QUEUE_FLAG_STACKABLE must be set after all queue settings are
1423 * visible to other CPUs because, once the flag is set, incoming bios
1424 * are processed by request-based dm, which refers to the queue
1425 * settings.
1426 * Until the flag set, bios are passed to bio-based dm and queued to
1427 * md->deferred where queue settings are not needed yet.
1428 * Those bios are passed to request-based dm at the resume time.
1429 */
1430 smp_mb();
1431 if (dm_table_request_based(t))
1432 queue_flag_set_unlocked(QUEUE_FLAG_STACKABLE, q);
1433}
1434
1435unsigned int dm_table_get_num_targets(struct dm_table *t)
1436{
1437 return t->num_targets;
1438}
1439
1440struct list_head *dm_table_get_devices(struct dm_table *t)
1441{
1442 return &t->devices;
1443}
1444
1445fmode_t dm_table_get_mode(struct dm_table *t)
1446{
1447 return t->mode;
1448}
1449EXPORT_SYMBOL(dm_table_get_mode);
1450
1451static void suspend_targets(struct dm_table *t, unsigned postsuspend)
1452{
1453 int i = t->num_targets;
1454 struct dm_target *ti = t->targets;
1455
1456 while (i--) {
1457 if (postsuspend) {
1458 if (ti->type->postsuspend)
1459 ti->type->postsuspend(ti);
1460 } else if (ti->type->presuspend)
1461 ti->type->presuspend(ti);
1462
1463 ti++;
1464 }
1465}
1466
1467void dm_table_presuspend_targets(struct dm_table *t)
1468{
1469 if (!t)
1470 return;
1471
1472 suspend_targets(t, 0);
1473}
1474
1475void dm_table_postsuspend_targets(struct dm_table *t)
1476{
1477 if (!t)
1478 return;
1479
1480 suspend_targets(t, 1);
1481}
1482
1483int dm_table_resume_targets(struct dm_table *t)
1484{
1485 int i, r = 0;
1486
1487 for (i = 0; i < t->num_targets; i++) {
1488 struct dm_target *ti = t->targets + i;
1489
1490 if (!ti->type->preresume)
1491 continue;
1492
1493 r = ti->type->preresume(ti);
1494 if (r)
1495 return r;
1496 }
1497
1498 for (i = 0; i < t->num_targets; i++) {
1499 struct dm_target *ti = t->targets + i;
1500
1501 if (ti->type->resume)
1502 ti->type->resume(ti);
1503 }
1504
1505 return 0;
1506}
1507
1508void dm_table_add_target_callbacks(struct dm_table *t, struct dm_target_callbacks *cb)
1509{
1510 list_add(&cb->list, &t->target_callbacks);
1511}
1512EXPORT_SYMBOL_GPL(dm_table_add_target_callbacks);
1513
1514int dm_table_any_congested(struct dm_table *t, int bdi_bits)
1515{
1516 struct dm_dev_internal *dd;
1517 struct list_head *devices = dm_table_get_devices(t);
1518 struct dm_target_callbacks *cb;
1519 int r = 0;
1520
1521 list_for_each_entry(dd, devices, list) {
1522 struct request_queue *q = bdev_get_queue(dd->dm_dev.bdev);
1523 char b[BDEVNAME_SIZE];
1524
1525 if (likely(q))
1526 r |= bdi_congested(&q->backing_dev_info, bdi_bits);
1527 else
1528 DMWARN_LIMIT("%s: any_congested: nonexistent device %s",
1529 dm_device_name(t->md),
1530 bdevname(dd->dm_dev.bdev, b));
1531 }
1532
1533 list_for_each_entry(cb, &t->target_callbacks, list)
1534 if (cb->congested_fn)
1535 r |= cb->congested_fn(cb, bdi_bits);
1536
1537 return r;
1538}
1539
1540int dm_table_any_busy_target(struct dm_table *t)
1541{
1542 unsigned i;
1543 struct dm_target *ti;
1544
1545 for (i = 0; i < t->num_targets; i++) {
1546 ti = t->targets + i;
1547 if (ti->type->busy && ti->type->busy(ti))
1548 return 1;
1549 }
1550
1551 return 0;
1552}
1553
1554struct mapped_device *dm_table_get_md(struct dm_table *t)
1555{
1556 return t->md;
1557}
1558EXPORT_SYMBOL(dm_table_get_md);
1559
1560static int device_discard_capable(struct dm_target *ti, struct dm_dev *dev,
1561 sector_t start, sector_t len, void *data)
1562{
1563 struct request_queue *q = bdev_get_queue(dev->bdev);
1564
1565 return q && blk_queue_discard(q);
1566}
1567
1568bool dm_table_supports_discards(struct dm_table *t)
1569{
1570 struct dm_target *ti;
1571 unsigned i = 0;
1572
1573 /*
1574 * Unless any target used by the table set discards_supported,
1575 * require at least one underlying device to support discards.
1576 * t->devices includes internal dm devices such as mirror logs
1577 * so we need to use iterate_devices here, which targets
1578 * supporting discard selectively must provide.
1579 */
1580 while (i < dm_table_get_num_targets(t)) {
1581 ti = dm_table_get_target(t, i++);
1582
1583 if (!ti->num_discard_requests)
1584 continue;
1585
1586 if (ti->discards_supported)
1587 return 1;
1588
1589 if (ti->type->iterate_devices &&
1590 ti->type->iterate_devices(ti, device_discard_capable, NULL))
1591 return 1;
1592 }
1593
1594 return 0;
1595}
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