2 * Copyright (C) 2001 Sistina Software (UK) Limited.
3 * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
5 * This file is released under the GPL.
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>
24 #define DM_MSG_PREFIX "table"
27 #define NODE_SIZE L1_CACHE_BYTES
28 #define KEYS_PER_NODE (NODE_SIZE / sizeof(sector_t))
29 #define CHILDREN_PER_NODE (KEYS_PER_NODE + 1)
32 struct mapped_device *md;
37 unsigned int counts[MAX_DEPTH]; /* in nodes */
38 sector_t *index[MAX_DEPTH];
40 unsigned int num_targets;
41 unsigned int num_allocated;
43 struct dm_target *targets;
45 struct target_type *immutable_target_type;
46 unsigned integrity_supported:1;
50 * Indicates the rw permissions for the new logical
51 * device. This should be a combination of FMODE_READ
56 /* a list of devices used by this table */
57 struct list_head devices;
59 /* events get handed up using this callback */
60 void (*event_fn)(void *);
63 struct dm_md_mempools *mempools;
65 struct list_head target_callbacks;
69 * Similar to ceiling(log_size(n))
71 static unsigned int int_log(unsigned int n, unsigned int base)
76 n = dm_div_up(n, base);
84 * Calculate the index of the child node of the n'th node k'th key.
86 static inline unsigned int get_child(unsigned int n, unsigned int k)
88 return (n * CHILDREN_PER_NODE) + k;
92 * Return the n'th node of level l from table t.
94 static inline sector_t *get_node(struct dm_table *t,
95 unsigned int l, unsigned int n)
97 return t->index[l] + (n * KEYS_PER_NODE);
101 * Return the highest key that you could lookup from the n'th
102 * node on level l of the btree.
104 static sector_t high(struct dm_table *t, unsigned int l, unsigned int n)
106 for (; l < t->depth - 1; l++)
107 n = get_child(n, CHILDREN_PER_NODE - 1);
109 if (n >= t->counts[l])
110 return (sector_t) - 1;
112 return get_node(t, l, n)[KEYS_PER_NODE - 1];
116 * Fills in a level of the btree based on the highs of the level
119 static int setup_btree_index(unsigned int l, struct dm_table *t)
124 for (n = 0U; n < t->counts[l]; n++) {
125 node = get_node(t, l, n);
127 for (k = 0U; k < KEYS_PER_NODE; k++)
128 node[k] = high(t, l + 1, get_child(n, k));
134 void *dm_vcalloc(unsigned long nmemb, unsigned long elem_size)
140 * Check that we're not going to overflow.
142 if (nmemb > (ULONG_MAX / elem_size))
145 size = nmemb * elem_size;
146 addr = vzalloc(size);
150 EXPORT_SYMBOL(dm_vcalloc);
153 * highs, and targets are managed as dynamic arrays during a
156 static int alloc_targets(struct dm_table *t, unsigned int num)
159 struct dm_target *n_targets;
162 * Allocate both the target array and offset array at once.
163 * Append an empty entry to catch sectors beyond the end of
166 n_highs = (sector_t *) dm_vcalloc(num + 1, sizeof(struct dm_target) +
171 n_targets = (struct dm_target *) (n_highs + num);
173 memset(n_highs, -1, sizeof(*n_highs) * num);
176 t->num_allocated = num;
178 t->targets = n_targets;
183 int dm_table_create(struct dm_table **result, fmode_t mode,
184 unsigned num_targets, struct mapped_device *md)
186 struct dm_table *t = kzalloc(sizeof(*t), GFP_KERNEL);
191 INIT_LIST_HEAD(&t->devices);
192 INIT_LIST_HEAD(&t->target_callbacks);
195 num_targets = KEYS_PER_NODE;
197 num_targets = dm_round_up(num_targets, KEYS_PER_NODE);
204 if (alloc_targets(t, num_targets)) {
215 static void free_devices(struct list_head *devices, struct mapped_device *md)
217 struct list_head *tmp, *next;
219 list_for_each_safe(tmp, next, devices) {
220 struct dm_dev_internal *dd =
221 list_entry(tmp, struct dm_dev_internal, list);
222 DMWARN("%s: dm_table_destroy: dm_put_device call missing for %s",
223 dm_device_name(md), dd->dm_dev->name);
224 dm_put_table_device(md, dd->dm_dev);
229 void dm_table_destroy(struct dm_table *t)
236 /* free the indexes */
238 vfree(t->index[t->depth - 2]);
240 /* free the targets */
241 for (i = 0; i < t->num_targets; i++) {
242 struct dm_target *tgt = t->targets + i;
247 dm_put_target_type(tgt->type);
252 /* free the device list */
253 free_devices(&t->devices, t->md);
255 dm_free_md_mempools(t->mempools);
261 * See if we've already got a device in the list.
263 static struct dm_dev_internal *find_device(struct list_head *l, dev_t dev)
265 struct dm_dev_internal *dd;
267 list_for_each_entry (dd, l, list)
268 if (dd->dm_dev->bdev->bd_dev == dev)
275 * If possible, this checks an area of a destination device is invalid.
277 static int device_area_is_invalid(struct dm_target *ti, struct dm_dev *dev,
278 sector_t start, sector_t len, void *data)
280 struct request_queue *q;
281 struct queue_limits *limits = data;
282 struct block_device *bdev = dev->bdev;
284 i_size_read(bdev->bd_inode) >> SECTOR_SHIFT;
285 unsigned short logical_block_size_sectors =
286 limits->logical_block_size >> SECTOR_SHIFT;
287 char b[BDEVNAME_SIZE];
290 * Some devices exist without request functions,
291 * such as loop devices not yet bound to backing files.
292 * Forbid the use of such devices.
294 q = bdev_get_queue(bdev);
295 if (!q || !q->make_request_fn) {
296 DMWARN("%s: %s is not yet initialised: "
297 "start=%llu, len=%llu, dev_size=%llu",
298 dm_device_name(ti->table->md), bdevname(bdev, b),
299 (unsigned long long)start,
300 (unsigned long long)len,
301 (unsigned long long)dev_size);
308 if ((start >= dev_size) || (start + len > dev_size)) {
309 DMWARN("%s: %s too small for target: "
310 "start=%llu, len=%llu, dev_size=%llu",
311 dm_device_name(ti->table->md), bdevname(bdev, b),
312 (unsigned long long)start,
313 (unsigned long long)len,
314 (unsigned long long)dev_size);
318 if (logical_block_size_sectors <= 1)
321 if (start & (logical_block_size_sectors - 1)) {
322 DMWARN("%s: start=%llu not aligned to h/w "
323 "logical block size %u of %s",
324 dm_device_name(ti->table->md),
325 (unsigned long long)start,
326 limits->logical_block_size, bdevname(bdev, b));
330 if (len & (logical_block_size_sectors - 1)) {
331 DMWARN("%s: len=%llu not aligned to h/w "
332 "logical block size %u of %s",
333 dm_device_name(ti->table->md),
334 (unsigned long long)len,
335 limits->logical_block_size, bdevname(bdev, b));
343 * This upgrades the mode on an already open dm_dev, being
344 * careful to leave things as they were if we fail to reopen the
345 * device and not to touch the existing bdev field in case
346 * it is accessed concurrently inside dm_table_any_congested().
348 static int upgrade_mode(struct dm_dev_internal *dd, fmode_t new_mode,
349 struct mapped_device *md)
352 struct dm_dev *old_dev, *new_dev;
354 old_dev = dd->dm_dev;
356 r = dm_get_table_device(md, dd->dm_dev->bdev->bd_dev,
357 dd->dm_dev->mode | new_mode, &new_dev);
361 dd->dm_dev = new_dev;
362 dm_put_table_device(md, old_dev);
368 * Add a device to the list, or just increment the usage count if
369 * it's already present.
371 int dm_get_device(struct dm_target *ti, const char *path, fmode_t mode,
372 struct dm_dev **result)
375 dev_t uninitialized_var(dev);
376 struct dm_dev_internal *dd;
377 struct dm_table *t = ti->table;
378 struct block_device *bdev;
382 /* convert the path to a device */
383 bdev = lookup_bdev(path);
385 dev = name_to_dev_t(path);
393 dd = find_device(&t->devices, dev);
395 dd = kmalloc(sizeof(*dd), GFP_KERNEL);
399 if ((r = dm_get_table_device(t->md, dev, mode, &dd->dm_dev))) {
404 atomic_set(&dd->count, 0);
405 list_add(&dd->list, &t->devices);
407 } else if (dd->dm_dev->mode != (mode | dd->dm_dev->mode)) {
408 r = upgrade_mode(dd, mode, t->md);
412 atomic_inc(&dd->count);
414 *result = dd->dm_dev;
417 EXPORT_SYMBOL(dm_get_device);
419 static int dm_set_device_limits(struct dm_target *ti, struct dm_dev *dev,
420 sector_t start, sector_t len, void *data)
422 struct queue_limits *limits = data;
423 struct block_device *bdev = dev->bdev;
424 struct request_queue *q = bdev_get_queue(bdev);
425 char b[BDEVNAME_SIZE];
428 DMWARN("%s: Cannot set limits for nonexistent device %s",
429 dm_device_name(ti->table->md), bdevname(bdev, b));
433 if (bdev_stack_limits(limits, bdev, start) < 0)
434 DMWARN("%s: adding target device %s caused an alignment inconsistency: "
435 "physical_block_size=%u, logical_block_size=%u, "
436 "alignment_offset=%u, start=%llu",
437 dm_device_name(ti->table->md), bdevname(bdev, b),
438 q->limits.physical_block_size,
439 q->limits.logical_block_size,
440 q->limits.alignment_offset,
441 (unsigned long long) start << SECTOR_SHIFT);
447 * Decrement a device's use count and remove it if necessary.
449 void dm_put_device(struct dm_target *ti, struct dm_dev *d)
452 struct list_head *devices = &ti->table->devices;
453 struct dm_dev_internal *dd;
455 list_for_each_entry(dd, devices, list) {
456 if (dd->dm_dev == d) {
462 DMWARN("%s: device %s not in table devices list",
463 dm_device_name(ti->table->md), d->name);
466 if (atomic_dec_and_test(&dd->count)) {
467 dm_put_table_device(ti->table->md, d);
472 EXPORT_SYMBOL(dm_put_device);
475 * Checks to see if the target joins onto the end of the table.
477 static int adjoin(struct dm_table *table, struct dm_target *ti)
479 struct dm_target *prev;
481 if (!table->num_targets)
484 prev = &table->targets[table->num_targets - 1];
485 return (ti->begin == (prev->begin + prev->len));
489 * Used to dynamically allocate the arg array.
491 * We do first allocation with GFP_NOIO because dm-mpath and dm-thin must
492 * process messages even if some device is suspended. These messages have a
493 * small fixed number of arguments.
495 * On the other hand, dm-switch needs to process bulk data using messages and
496 * excessive use of GFP_NOIO could cause trouble.
498 static char **realloc_argv(unsigned *array_size, char **old_argv)
505 new_size = *array_size * 2;
511 argv = kmalloc(new_size * sizeof(*argv), gfp);
513 memcpy(argv, old_argv, *array_size * sizeof(*argv));
514 *array_size = new_size;
522 * Destructively splits up the argument list to pass to ctr.
524 int dm_split_args(int *argc, char ***argvp, char *input)
526 char *start, *end = input, *out, **argv = NULL;
527 unsigned array_size = 0;
536 argv = realloc_argv(&array_size, argv);
541 /* Skip whitespace */
542 start = skip_spaces(end);
545 break; /* success, we hit the end */
547 /* 'out' is used to remove any back-quotes */
550 /* Everything apart from '\0' can be quoted */
551 if (*end == '\\' && *(end + 1)) {
558 break; /* end of token */
563 /* have we already filled the array ? */
564 if ((*argc + 1) > array_size) {
565 argv = realloc_argv(&array_size, argv);
570 /* we know this is whitespace */
574 /* terminate the string and put it in the array */
585 * Impose necessary and sufficient conditions on a devices's table such
586 * that any incoming bio which respects its logical_block_size can be
587 * processed successfully. If it falls across the boundary between
588 * two or more targets, the size of each piece it gets split into must
589 * be compatible with the logical_block_size of the target processing it.
591 static int validate_hardware_logical_block_alignment(struct dm_table *table,
592 struct queue_limits *limits)
595 * This function uses arithmetic modulo the logical_block_size
596 * (in units of 512-byte sectors).
598 unsigned short device_logical_block_size_sects =
599 limits->logical_block_size >> SECTOR_SHIFT;
602 * Offset of the start of the next table entry, mod logical_block_size.
604 unsigned short next_target_start = 0;
607 * Given an aligned bio that extends beyond the end of a
608 * target, how many sectors must the next target handle?
610 unsigned short remaining = 0;
612 struct dm_target *uninitialized_var(ti);
613 struct queue_limits ti_limits;
617 * Check each entry in the table in turn.
619 while (i < dm_table_get_num_targets(table)) {
620 ti = dm_table_get_target(table, i++);
622 blk_set_stacking_limits(&ti_limits);
624 /* combine all target devices' limits */
625 if (ti->type->iterate_devices)
626 ti->type->iterate_devices(ti, dm_set_device_limits,
630 * If the remaining sectors fall entirely within this
631 * table entry are they compatible with its logical_block_size?
633 if (remaining < ti->len &&
634 remaining & ((ti_limits.logical_block_size >>
639 (unsigned short) ((next_target_start + ti->len) &
640 (device_logical_block_size_sects - 1));
641 remaining = next_target_start ?
642 device_logical_block_size_sects - next_target_start : 0;
646 DMWARN("%s: table line %u (start sect %llu len %llu) "
647 "not aligned to h/w logical block size %u",
648 dm_device_name(table->md), i,
649 (unsigned long long) ti->begin,
650 (unsigned long long) ti->len,
651 limits->logical_block_size);
658 int dm_table_add_target(struct dm_table *t, const char *type,
659 sector_t start, sector_t len, char *params)
661 int r = -EINVAL, argc;
663 struct dm_target *tgt;
666 DMERR("%s: target type %s must appear alone in table",
667 dm_device_name(t->md), t->targets->type->name);
671 BUG_ON(t->num_targets >= t->num_allocated);
673 tgt = t->targets + t->num_targets;
674 memset(tgt, 0, sizeof(*tgt));
677 DMERR("%s: zero-length target", dm_device_name(t->md));
681 tgt->type = dm_get_target_type(type);
683 DMERR("%s: %s: unknown target type", dm_device_name(t->md),
688 if (dm_target_needs_singleton(tgt->type)) {
689 if (t->num_targets) {
690 DMERR("%s: target type %s must appear alone in table",
691 dm_device_name(t->md), type);
697 if (dm_target_always_writeable(tgt->type) && !(t->mode & FMODE_WRITE)) {
698 DMERR("%s: target type %s may not be included in read-only tables",
699 dm_device_name(t->md), type);
703 if (t->immutable_target_type) {
704 if (t->immutable_target_type != tgt->type) {
705 DMERR("%s: immutable target type %s cannot be mixed with other target types",
706 dm_device_name(t->md), t->immutable_target_type->name);
709 } else if (dm_target_is_immutable(tgt->type)) {
710 if (t->num_targets) {
711 DMERR("%s: immutable target type %s cannot be mixed with other target types",
712 dm_device_name(t->md), tgt->type->name);
715 t->immutable_target_type = tgt->type;
721 tgt->error = "Unknown error";
724 * Does this target adjoin the previous one ?
726 if (!adjoin(t, tgt)) {
727 tgt->error = "Gap in table";
732 r = dm_split_args(&argc, &argv, params);
734 tgt->error = "couldn't split parameters (insufficient memory)";
738 r = tgt->type->ctr(tgt, argc, argv);
743 t->highs[t->num_targets++] = tgt->begin + tgt->len - 1;
745 if (!tgt->num_discard_bios && tgt->discards_supported)
746 DMWARN("%s: %s: ignoring discards_supported because num_discard_bios is zero.",
747 dm_device_name(t->md), type);
752 DMERR("%s: %s: %s", dm_device_name(t->md), type, tgt->error);
753 dm_put_target_type(tgt->type);
758 * Target argument parsing helpers.
760 static int validate_next_arg(struct dm_arg *arg, struct dm_arg_set *arg_set,
761 unsigned *value, char **error, unsigned grouped)
763 const char *arg_str = dm_shift_arg(arg_set);
767 (sscanf(arg_str, "%u%c", value, &dummy) != 1) ||
768 (*value < arg->min) ||
769 (*value > arg->max) ||
770 (grouped && arg_set->argc < *value)) {
778 int dm_read_arg(struct dm_arg *arg, struct dm_arg_set *arg_set,
779 unsigned *value, char **error)
781 return validate_next_arg(arg, arg_set, value, error, 0);
783 EXPORT_SYMBOL(dm_read_arg);
785 int dm_read_arg_group(struct dm_arg *arg, struct dm_arg_set *arg_set,
786 unsigned *value, char **error)
788 return validate_next_arg(arg, arg_set, value, error, 1);
790 EXPORT_SYMBOL(dm_read_arg_group);
792 const char *dm_shift_arg(struct dm_arg_set *as)
805 EXPORT_SYMBOL(dm_shift_arg);
807 void dm_consume_args(struct dm_arg_set *as, unsigned num_args)
809 BUG_ON(as->argc < num_args);
810 as->argc -= num_args;
811 as->argv += num_args;
813 EXPORT_SYMBOL(dm_consume_args);
815 static bool __table_type_request_based(unsigned table_type)
817 return (table_type == DM_TYPE_REQUEST_BASED ||
818 table_type == DM_TYPE_MQ_REQUEST_BASED);
821 static int dm_table_set_type(struct dm_table *t)
824 unsigned bio_based = 0, request_based = 0, hybrid = 0;
825 bool use_blk_mq = false;
826 struct dm_target *tgt;
827 struct dm_dev_internal *dd;
828 struct list_head *devices;
829 unsigned live_md_type = dm_get_md_type(t->md);
831 for (i = 0; i < t->num_targets; i++) {
832 tgt = t->targets + i;
833 if (dm_target_hybrid(tgt))
835 else if (dm_target_request_based(tgt))
840 if (bio_based && request_based) {
841 DMWARN("Inconsistent table: different target types"
842 " can't be mixed up");
847 if (hybrid && !bio_based && !request_based) {
849 * The targets can work either way.
850 * Determine the type from the live device.
851 * Default to bio-based if device is new.
853 if (__table_type_request_based(live_md_type))
860 /* We must use this table as bio-based */
861 t->type = DM_TYPE_BIO_BASED;
865 BUG_ON(!request_based); /* No targets in this table */
868 * Request-based dm supports only tables that have a single target now.
869 * To support multiple targets, request splitting support is needed,
870 * and that needs lots of changes in the block-layer.
871 * (e.g. request completion process for partial completion.)
873 if (t->num_targets > 1) {
874 DMWARN("Request-based dm doesn't support multiple targets yet");
878 /* Non-request-stackable devices can't be used for request-based dm */
879 devices = dm_table_get_devices(t);
880 list_for_each_entry(dd, devices, list) {
881 struct request_queue *q = bdev_get_queue(dd->dm_dev->bdev);
883 if (!blk_queue_stackable(q)) {
884 DMERR("table load rejected: including"
885 " non-request-stackable devices");
894 /* verify _all_ devices in the table are blk-mq devices */
895 list_for_each_entry(dd, devices, list)
896 if (!bdev_get_queue(dd->dm_dev->bdev)->mq_ops) {
897 DMERR("table load rejected: not all devices"
898 " are blk-mq request-stackable");
901 t->type = DM_TYPE_MQ_REQUEST_BASED;
903 } else if (list_empty(devices) && __table_type_request_based(live_md_type)) {
904 /* inherit live MD type */
905 t->type = live_md_type;
908 t->type = DM_TYPE_REQUEST_BASED;
913 unsigned dm_table_get_type(struct dm_table *t)
918 struct target_type *dm_table_get_immutable_target_type(struct dm_table *t)
920 return t->immutable_target_type;
923 bool dm_table_request_based(struct dm_table *t)
925 return __table_type_request_based(dm_table_get_type(t));
928 bool dm_table_mq_request_based(struct dm_table *t)
930 return dm_table_get_type(t) == DM_TYPE_MQ_REQUEST_BASED;
933 static int dm_table_alloc_md_mempools(struct dm_table *t, struct mapped_device *md)
935 unsigned type = dm_table_get_type(t);
936 unsigned per_bio_data_size = 0;
937 struct dm_target *tgt;
940 if (unlikely(type == DM_TYPE_NONE)) {
941 DMWARN("no table type is set, can't allocate mempools");
945 if (type == DM_TYPE_BIO_BASED)
946 for (i = 0; i < t->num_targets; i++) {
947 tgt = t->targets + i;
948 per_bio_data_size = max(per_bio_data_size, tgt->per_bio_data_size);
951 t->mempools = dm_alloc_md_mempools(md, type, t->integrity_supported, per_bio_data_size);
958 void dm_table_free_md_mempools(struct dm_table *t)
960 dm_free_md_mempools(t->mempools);
964 struct dm_md_mempools *dm_table_get_md_mempools(struct dm_table *t)
969 static int setup_indexes(struct dm_table *t)
972 unsigned int total = 0;
975 /* allocate the space for *all* the indexes */
976 for (i = t->depth - 2; i >= 0; i--) {
977 t->counts[i] = dm_div_up(t->counts[i + 1], CHILDREN_PER_NODE);
978 total += t->counts[i];
981 indexes = (sector_t *) dm_vcalloc(total, (unsigned long) NODE_SIZE);
985 /* set up internal nodes, bottom-up */
986 for (i = t->depth - 2; i >= 0; i--) {
987 t->index[i] = indexes;
988 indexes += (KEYS_PER_NODE * t->counts[i]);
989 setup_btree_index(i, t);
996 * Builds the btree to index the map.
998 static int dm_table_build_index(struct dm_table *t)
1001 unsigned int leaf_nodes;
1003 /* how many indexes will the btree have ? */
1004 leaf_nodes = dm_div_up(t->num_targets, KEYS_PER_NODE);
1005 t->depth = 1 + int_log(leaf_nodes, CHILDREN_PER_NODE);
1007 /* leaf layer has already been set up */
1008 t->counts[t->depth - 1] = leaf_nodes;
1009 t->index[t->depth - 1] = t->highs;
1012 r = setup_indexes(t);
1018 * Get a disk whose integrity profile reflects the table's profile.
1019 * If %match_all is true, all devices' profiles must match.
1020 * If %match_all is false, all devices must at least have an
1021 * allocated integrity profile; but uninitialized is ok.
1022 * Returns NULL if integrity support was inconsistent or unavailable.
1024 static struct gendisk * dm_table_get_integrity_disk(struct dm_table *t,
1027 struct list_head *devices = dm_table_get_devices(t);
1028 struct dm_dev_internal *dd = NULL;
1029 struct gendisk *prev_disk = NULL, *template_disk = NULL;
1031 list_for_each_entry(dd, devices, list) {
1032 template_disk = dd->dm_dev->bdev->bd_disk;
1033 if (!blk_get_integrity(template_disk))
1035 if (!match_all && !blk_integrity_is_initialized(template_disk))
1036 continue; /* skip uninitialized profiles */
1037 else if (prev_disk &&
1038 blk_integrity_compare(prev_disk, template_disk) < 0)
1040 prev_disk = template_disk;
1043 return template_disk;
1047 DMWARN("%s: integrity not set: %s and %s profile mismatch",
1048 dm_device_name(t->md),
1049 prev_disk->disk_name,
1050 template_disk->disk_name);
1055 * Register the mapped device for blk_integrity support if
1056 * the underlying devices have an integrity profile. But all devices
1057 * may not have matching profiles (checking all devices isn't reliable
1058 * during table load because this table may use other DM device(s) which
1059 * must be resumed before they will have an initialized integity profile).
1060 * Stacked DM devices force a 2 stage integrity profile validation:
1061 * 1 - during load, validate all initialized integrity profiles match
1062 * 2 - during resume, validate all integrity profiles match
1064 static int dm_table_prealloc_integrity(struct dm_table *t, struct mapped_device *md)
1066 struct gendisk *template_disk = NULL;
1068 template_disk = dm_table_get_integrity_disk(t, false);
1072 if (!blk_integrity_is_initialized(dm_disk(md))) {
1073 t->integrity_supported = 1;
1074 return blk_integrity_register(dm_disk(md), NULL);
1078 * If DM device already has an initalized integrity
1079 * profile the new profile should not conflict.
1081 if (blk_integrity_is_initialized(template_disk) &&
1082 blk_integrity_compare(dm_disk(md), template_disk) < 0) {
1083 DMWARN("%s: conflict with existing integrity profile: "
1084 "%s profile mismatch",
1085 dm_device_name(t->md),
1086 template_disk->disk_name);
1090 /* Preserve existing initialized integrity profile */
1091 t->integrity_supported = 1;
1096 * Prepares the table for use by building the indices,
1097 * setting the type, and allocating mempools.
1099 int dm_table_complete(struct dm_table *t)
1103 r = dm_table_set_type(t);
1105 DMERR("unable to set table type");
1109 r = dm_table_build_index(t);
1111 DMERR("unable to build btrees");
1115 r = dm_table_prealloc_integrity(t, t->md);
1117 DMERR("could not register integrity profile.");
1121 r = dm_table_alloc_md_mempools(t, t->md);
1123 DMERR("unable to allocate mempools");
1128 static DEFINE_MUTEX(_event_lock);
1129 void dm_table_event_callback(struct dm_table *t,
1130 void (*fn)(void *), void *context)
1132 mutex_lock(&_event_lock);
1134 t->event_context = context;
1135 mutex_unlock(&_event_lock);
1138 void dm_table_event(struct dm_table *t)
1141 * You can no longer call dm_table_event() from interrupt
1142 * context, use a bottom half instead.
1144 BUG_ON(in_interrupt());
1146 mutex_lock(&_event_lock);
1148 t->event_fn(t->event_context);
1149 mutex_unlock(&_event_lock);
1151 EXPORT_SYMBOL(dm_table_event);
1153 sector_t dm_table_get_size(struct dm_table *t)
1155 return t->num_targets ? (t->highs[t->num_targets - 1] + 1) : 0;
1157 EXPORT_SYMBOL(dm_table_get_size);
1159 struct dm_target *dm_table_get_target(struct dm_table *t, unsigned int index)
1161 if (index >= t->num_targets)
1164 return t->targets + index;
1168 * Search the btree for the correct target.
1170 * Caller should check returned pointer with dm_target_is_valid()
1171 * to trap I/O beyond end of device.
1173 struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector)
1175 unsigned int l, n = 0, k = 0;
1178 for (l = 0; l < t->depth; l++) {
1179 n = get_child(n, k);
1180 node = get_node(t, l, n);
1182 for (k = 0; k < KEYS_PER_NODE; k++)
1183 if (node[k] >= sector)
1187 return &t->targets[(KEYS_PER_NODE * n) + k];
1190 static int count_device(struct dm_target *ti, struct dm_dev *dev,
1191 sector_t start, sector_t len, void *data)
1193 unsigned *num_devices = data;
1201 * Check whether a table has no data devices attached using each
1202 * target's iterate_devices method.
1203 * Returns false if the result is unknown because a target doesn't
1204 * support iterate_devices.
1206 bool dm_table_has_no_data_devices(struct dm_table *table)
1208 struct dm_target *uninitialized_var(ti);
1209 unsigned i = 0, num_devices = 0;
1211 while (i < dm_table_get_num_targets(table)) {
1212 ti = dm_table_get_target(table, i++);
1214 if (!ti->type->iterate_devices)
1217 ti->type->iterate_devices(ti, count_device, &num_devices);
1226 * Establish the new table's queue_limits and validate them.
1228 int dm_calculate_queue_limits(struct dm_table *table,
1229 struct queue_limits *limits)
1231 struct dm_target *uninitialized_var(ti);
1232 struct queue_limits ti_limits;
1235 blk_set_stacking_limits(limits);
1237 while (i < dm_table_get_num_targets(table)) {
1238 blk_set_stacking_limits(&ti_limits);
1240 ti = dm_table_get_target(table, i++);
1242 if (!ti->type->iterate_devices)
1243 goto combine_limits;
1246 * Combine queue limits of all the devices this target uses.
1248 ti->type->iterate_devices(ti, dm_set_device_limits,
1251 /* Set I/O hints portion of queue limits */
1252 if (ti->type->io_hints)
1253 ti->type->io_hints(ti, &ti_limits);
1256 * Check each device area is consistent with the target's
1257 * overall queue limits.
1259 if (ti->type->iterate_devices(ti, device_area_is_invalid,
1265 * Merge this target's queue limits into the overall limits
1268 if (blk_stack_limits(limits, &ti_limits, 0) < 0)
1269 DMWARN("%s: adding target device "
1270 "(start sect %llu len %llu) "
1271 "caused an alignment inconsistency",
1272 dm_device_name(table->md),
1273 (unsigned long long) ti->begin,
1274 (unsigned long long) ti->len);
1277 return validate_hardware_logical_block_alignment(table, limits);
1281 * Set the integrity profile for this device if all devices used have
1282 * matching profiles. We're quite deep in the resume path but still
1283 * don't know if all devices (particularly DM devices this device
1284 * may be stacked on) have matching profiles. Even if the profiles
1285 * don't match we have no way to fail (to resume) at this point.
1287 static void dm_table_set_integrity(struct dm_table *t)
1289 struct gendisk *template_disk = NULL;
1291 if (!blk_get_integrity(dm_disk(t->md)))
1294 template_disk = dm_table_get_integrity_disk(t, true);
1296 blk_integrity_register(dm_disk(t->md),
1297 blk_get_integrity(template_disk));
1298 else if (blk_integrity_is_initialized(dm_disk(t->md)))
1299 DMWARN("%s: device no longer has a valid integrity profile",
1300 dm_device_name(t->md));
1302 DMWARN("%s: unable to establish an integrity profile",
1303 dm_device_name(t->md));
1306 static int device_flush_capable(struct dm_target *ti, struct dm_dev *dev,
1307 sector_t start, sector_t len, void *data)
1309 unsigned flush = (*(unsigned *)data);
1310 struct request_queue *q = bdev_get_queue(dev->bdev);
1312 return q && (q->flush_flags & flush);
1315 static bool dm_table_supports_flush(struct dm_table *t, unsigned flush)
1317 struct dm_target *ti;
1321 * Require at least one underlying device to support flushes.
1322 * t->devices includes internal dm devices such as mirror logs
1323 * so we need to use iterate_devices here, which targets
1324 * supporting flushes must provide.
1326 while (i < dm_table_get_num_targets(t)) {
1327 ti = dm_table_get_target(t, i++);
1329 if (!ti->num_flush_bios)
1332 if (ti->flush_supported)
1335 if (ti->type->iterate_devices &&
1336 ti->type->iterate_devices(ti, device_flush_capable, &flush))
1343 static bool dm_table_discard_zeroes_data(struct dm_table *t)
1345 struct dm_target *ti;
1348 /* Ensure that all targets supports discard_zeroes_data. */
1349 while (i < dm_table_get_num_targets(t)) {
1350 ti = dm_table_get_target(t, i++);
1352 if (ti->discard_zeroes_data_unsupported)
1359 static int device_is_nonrot(struct dm_target *ti, struct dm_dev *dev,
1360 sector_t start, sector_t len, void *data)
1362 struct request_queue *q = bdev_get_queue(dev->bdev);
1364 return q && blk_queue_nonrot(q);
1367 static int device_is_not_random(struct dm_target *ti, struct dm_dev *dev,
1368 sector_t start, sector_t len, void *data)
1370 struct request_queue *q = bdev_get_queue(dev->bdev);
1372 return q && !blk_queue_add_random(q);
1375 static int queue_supports_sg_merge(struct dm_target *ti, struct dm_dev *dev,
1376 sector_t start, sector_t len, void *data)
1378 struct request_queue *q = bdev_get_queue(dev->bdev);
1380 return q && !test_bit(QUEUE_FLAG_NO_SG_MERGE, &q->queue_flags);
1383 static bool dm_table_all_devices_attribute(struct dm_table *t,
1384 iterate_devices_callout_fn func)
1386 struct dm_target *ti;
1389 while (i < dm_table_get_num_targets(t)) {
1390 ti = dm_table_get_target(t, i++);
1392 if (!ti->type->iterate_devices ||
1393 !ti->type->iterate_devices(ti, func, NULL))
1400 static int device_not_write_same_capable(struct dm_target *ti, struct dm_dev *dev,
1401 sector_t start, sector_t len, void *data)
1403 struct request_queue *q = bdev_get_queue(dev->bdev);
1405 return q && !q->limits.max_write_same_sectors;
1408 static bool dm_table_supports_write_same(struct dm_table *t)
1410 struct dm_target *ti;
1413 while (i < dm_table_get_num_targets(t)) {
1414 ti = dm_table_get_target(t, i++);
1416 if (!ti->num_write_same_bios)
1419 if (!ti->type->iterate_devices ||
1420 ti->type->iterate_devices(ti, device_not_write_same_capable, NULL))
1427 static int device_discard_capable(struct dm_target *ti, struct dm_dev *dev,
1428 sector_t start, sector_t len, void *data)
1430 struct request_queue *q = bdev_get_queue(dev->bdev);
1432 return q && blk_queue_discard(q);
1435 static bool dm_table_supports_discards(struct dm_table *t)
1437 struct dm_target *ti;
1441 * Unless any target used by the table set discards_supported,
1442 * require at least one underlying device to support discards.
1443 * t->devices includes internal dm devices such as mirror logs
1444 * so we need to use iterate_devices here, which targets
1445 * supporting discard selectively must provide.
1447 while (i < dm_table_get_num_targets(t)) {
1448 ti = dm_table_get_target(t, i++);
1450 if (!ti->num_discard_bios)
1453 if (ti->discards_supported)
1456 if (ti->type->iterate_devices &&
1457 ti->type->iterate_devices(ti, device_discard_capable, NULL))
1464 void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
1465 struct queue_limits *limits)
1470 * Copy table's limits to the DM device's request_queue
1472 q->limits = *limits;
1474 if (!dm_table_supports_discards(t))
1475 queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, q);
1477 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q);
1479 if (dm_table_supports_flush(t, REQ_FLUSH)) {
1481 if (dm_table_supports_flush(t, REQ_FUA))
1484 blk_queue_flush(q, flush);
1486 if (!dm_table_discard_zeroes_data(t))
1487 q->limits.discard_zeroes_data = 0;
1489 /* Ensure that all underlying devices are non-rotational. */
1490 if (dm_table_all_devices_attribute(t, device_is_nonrot))
1491 queue_flag_set_unlocked(QUEUE_FLAG_NONROT, q);
1493 queue_flag_clear_unlocked(QUEUE_FLAG_NONROT, q);
1495 if (!dm_table_supports_write_same(t))
1496 q->limits.max_write_same_sectors = 0;
1498 if (dm_table_all_devices_attribute(t, queue_supports_sg_merge))
1499 queue_flag_clear_unlocked(QUEUE_FLAG_NO_SG_MERGE, q);
1501 queue_flag_set_unlocked(QUEUE_FLAG_NO_SG_MERGE, q);
1503 dm_table_set_integrity(t);
1506 * Determine whether or not this queue's I/O timings contribute
1507 * to the entropy pool, Only request-based targets use this.
1508 * Clear QUEUE_FLAG_ADD_RANDOM if any underlying device does not
1511 if (blk_queue_add_random(q) && dm_table_all_devices_attribute(t, device_is_not_random))
1512 queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, q);
1515 * QUEUE_FLAG_STACKABLE must be set after all queue settings are
1516 * visible to other CPUs because, once the flag is set, incoming bios
1517 * are processed by request-based dm, which refers to the queue
1519 * Until the flag set, bios are passed to bio-based dm and queued to
1520 * md->deferred where queue settings are not needed yet.
1521 * Those bios are passed to request-based dm at the resume time.
1524 if (dm_table_request_based(t))
1525 queue_flag_set_unlocked(QUEUE_FLAG_STACKABLE, q);
1528 unsigned int dm_table_get_num_targets(struct dm_table *t)
1530 return t->num_targets;
1533 struct list_head *dm_table_get_devices(struct dm_table *t)
1538 fmode_t dm_table_get_mode(struct dm_table *t)
1542 EXPORT_SYMBOL(dm_table_get_mode);
1550 static void suspend_targets(struct dm_table *t, enum suspend_mode mode)
1552 int i = t->num_targets;
1553 struct dm_target *ti = t->targets;
1558 if (ti->type->presuspend)
1559 ti->type->presuspend(ti);
1561 case PRESUSPEND_UNDO:
1562 if (ti->type->presuspend_undo)
1563 ti->type->presuspend_undo(ti);
1566 if (ti->type->postsuspend)
1567 ti->type->postsuspend(ti);
1574 void dm_table_presuspend_targets(struct dm_table *t)
1579 suspend_targets(t, PRESUSPEND);
1582 void dm_table_presuspend_undo_targets(struct dm_table *t)
1587 suspend_targets(t, PRESUSPEND_UNDO);
1590 void dm_table_postsuspend_targets(struct dm_table *t)
1595 suspend_targets(t, POSTSUSPEND);
1598 int dm_table_resume_targets(struct dm_table *t)
1602 for (i = 0; i < t->num_targets; i++) {
1603 struct dm_target *ti = t->targets + i;
1605 if (!ti->type->preresume)
1608 r = ti->type->preresume(ti);
1610 DMERR("%s: %s: preresume failed, error = %d",
1611 dm_device_name(t->md), ti->type->name, r);
1616 for (i = 0; i < t->num_targets; i++) {
1617 struct dm_target *ti = t->targets + i;
1619 if (ti->type->resume)
1620 ti->type->resume(ti);
1626 void dm_table_add_target_callbacks(struct dm_table *t, struct dm_target_callbacks *cb)
1628 list_add(&cb->list, &t->target_callbacks);
1630 EXPORT_SYMBOL_GPL(dm_table_add_target_callbacks);
1632 int dm_table_any_congested(struct dm_table *t, int bdi_bits)
1634 struct dm_dev_internal *dd;
1635 struct list_head *devices = dm_table_get_devices(t);
1636 struct dm_target_callbacks *cb;
1639 list_for_each_entry(dd, devices, list) {
1640 struct request_queue *q = bdev_get_queue(dd->dm_dev->bdev);
1641 char b[BDEVNAME_SIZE];
1644 r |= bdi_congested(&q->backing_dev_info, bdi_bits);
1646 DMWARN_LIMIT("%s: any_congested: nonexistent device %s",
1647 dm_device_name(t->md),
1648 bdevname(dd->dm_dev->bdev, b));
1651 list_for_each_entry(cb, &t->target_callbacks, list)
1652 if (cb->congested_fn)
1653 r |= cb->congested_fn(cb, bdi_bits);
1658 struct mapped_device *dm_table_get_md(struct dm_table *t)
1662 EXPORT_SYMBOL(dm_table_get_md);
1664 void dm_table_run_md_queue_async(struct dm_table *t)
1666 struct mapped_device *md;
1667 struct request_queue *queue;
1668 unsigned long flags;
1670 if (!dm_table_request_based(t))
1673 md = dm_table_get_md(t);
1674 queue = dm_get_md_queue(md);
1677 blk_mq_run_hw_queues(queue, true);
1679 spin_lock_irqsave(queue->queue_lock, flags);
1680 blk_run_queue_async(queue);
1681 spin_unlock_irqrestore(queue->queue_lock, flags);
1685 EXPORT_SYMBOL(dm_table_run_md_queue_async);