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 <asm/atomic.h>
22 #define DM_MSG_PREFIX "table"
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)
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.
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.
38 * When the table is about to be destroyed, we wait for table->holders to
43 struct mapped_device *md;
49 unsigned int counts[MAX_DEPTH]; /* in nodes */
50 sector_t *index[MAX_DEPTH];
52 unsigned int num_targets;
53 unsigned int num_allocated;
55 struct dm_target *targets;
57 unsigned discards_supported:1;
60 * Indicates the rw permissions for the new logical
61 * device. This should be a combination of FMODE_READ
66 /* a list of devices used by this table */
67 struct list_head devices;
69 /* events get handed up using this callback */
70 void (*event_fn)(void *);
73 struct dm_md_mempools *mempools;
75 struct list_head target_callbacks;
79 * Similar to ceiling(log_size(n))
81 static unsigned int int_log(unsigned int n, unsigned int base)
86 n = dm_div_up(n, base);
94 * Calculate the index of the child node of the n'th node k'th key.
96 static inline unsigned int get_child(unsigned int n, unsigned int k)
98 return (n * CHILDREN_PER_NODE) + k;
102 * Return the n'th node of level l from table t.
104 static inline sector_t *get_node(struct dm_table *t,
105 unsigned int l, unsigned int n)
107 return t->index[l] + (n * KEYS_PER_NODE);
111 * Return the highest key that you could lookup from the n'th
112 * node on level l of the btree.
114 static sector_t high(struct dm_table *t, unsigned int l, unsigned int n)
116 for (; l < t->depth - 1; l++)
117 n = get_child(n, CHILDREN_PER_NODE - 1);
119 if (n >= t->counts[l])
120 return (sector_t) - 1;
122 return get_node(t, l, n)[KEYS_PER_NODE - 1];
126 * Fills in a level of the btree based on the highs of the level
129 static int setup_btree_index(unsigned int l, struct dm_table *t)
134 for (n = 0U; n < t->counts[l]; n++) {
135 node = get_node(t, l, n);
137 for (k = 0U; k < KEYS_PER_NODE; k++)
138 node[k] = high(t, l + 1, get_child(n, k));
144 void *dm_vcalloc(unsigned long nmemb, unsigned long elem_size)
150 * Check that we're not going to overflow.
152 if (nmemb > (ULONG_MAX / elem_size))
155 size = nmemb * elem_size;
156 addr = vmalloc(size);
158 memset(addr, 0, size);
164 * highs, and targets are managed as dynamic arrays during a
167 static int alloc_targets(struct dm_table *t, unsigned int num)
170 struct dm_target *n_targets;
171 int n = t->num_targets;
174 * Allocate both the target array and offset array at once.
175 * Append an empty entry to catch sectors beyond the end of
178 n_highs = (sector_t *) dm_vcalloc(num + 1, sizeof(struct dm_target) +
183 n_targets = (struct dm_target *) (n_highs + num);
186 memcpy(n_highs, t->highs, sizeof(*n_highs) * n);
187 memcpy(n_targets, t->targets, sizeof(*n_targets) * n);
190 memset(n_highs + n, -1, sizeof(*n_highs) * (num - n));
193 t->num_allocated = num;
195 t->targets = n_targets;
200 int dm_table_create(struct dm_table **result, fmode_t mode,
201 unsigned num_targets, struct mapped_device *md)
203 struct dm_table *t = kzalloc(sizeof(*t), GFP_KERNEL);
208 INIT_LIST_HEAD(&t->devices);
209 INIT_LIST_HEAD(&t->target_callbacks);
210 atomic_set(&t->holders, 0);
211 t->discards_supported = 1;
214 num_targets = KEYS_PER_NODE;
216 num_targets = dm_round_up(num_targets, KEYS_PER_NODE);
218 if (alloc_targets(t, num_targets)) {
230 static void free_devices(struct list_head *devices)
232 struct list_head *tmp, *next;
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",
243 void dm_table_destroy(struct dm_table *t)
250 while (atomic_read(&t->holders))
254 /* free the indexes */
256 vfree(t->index[t->depth - 2]);
258 /* free the targets */
259 for (i = 0; i < t->num_targets; i++) {
260 struct dm_target *tgt = t->targets + i;
265 dm_put_target_type(tgt->type);
270 /* free the device list */
271 if (t->devices.next != &t->devices)
272 free_devices(&t->devices);
274 dm_free_md_mempools(t->mempools);
279 void dm_table_get(struct dm_table *t)
281 atomic_inc(&t->holders);
284 void dm_table_put(struct dm_table *t)
289 smp_mb__before_atomic_dec();
290 atomic_dec(&t->holders);
294 * Checks to see if we need to extend highs or targets.
296 static inline int check_space(struct dm_table *t)
298 if (t->num_targets >= t->num_allocated)
299 return alloc_targets(t, t->num_allocated * 2);
305 * See if we've already got a device in the list.
307 static struct dm_dev_internal *find_device(struct list_head *l, dev_t dev)
309 struct dm_dev_internal *dd;
311 list_for_each_entry (dd, l, list)
312 if (dd->dm_dev.bdev->bd_dev == dev)
319 * Open a device so we can use it as a map destination.
321 static int open_dev(struct dm_dev_internal *d, dev_t dev,
322 struct mapped_device *md)
324 static char *_claim_ptr = "I belong to device-mapper";
325 struct block_device *bdev;
329 BUG_ON(d->dm_dev.bdev);
331 bdev = blkdev_get_by_dev(dev, d->dm_dev.mode | FMODE_EXCL, _claim_ptr);
333 return PTR_ERR(bdev);
335 r = bd_link_disk_holder(bdev, dm_disk(md));
337 blkdev_put(bdev, d->dm_dev.mode | FMODE_EXCL);
341 d->dm_dev.bdev = bdev;
346 * Close a device that we've been using.
348 static void close_dev(struct dm_dev_internal *d, struct mapped_device *md)
353 blkdev_put(d->dm_dev.bdev, d->dm_dev.mode | FMODE_EXCL);
354 d->dm_dev.bdev = NULL;
358 * If possible, this checks an area of a destination device is invalid.
360 static int device_area_is_invalid(struct dm_target *ti, struct dm_dev *dev,
361 sector_t start, sector_t len, void *data)
363 struct queue_limits *limits = data;
364 struct block_device *bdev = dev->bdev;
366 i_size_read(bdev->bd_inode) >> SECTOR_SHIFT;
367 unsigned short logical_block_size_sectors =
368 limits->logical_block_size >> SECTOR_SHIFT;
369 char b[BDEVNAME_SIZE];
374 if ((start >= dev_size) || (start + len > dev_size)) {
375 DMWARN("%s: %s too small for target: "
376 "start=%llu, len=%llu, dev_size=%llu",
377 dm_device_name(ti->table->md), bdevname(bdev, b),
378 (unsigned long long)start,
379 (unsigned long long)len,
380 (unsigned long long)dev_size);
384 if (logical_block_size_sectors <= 1)
387 if (start & (logical_block_size_sectors - 1)) {
388 DMWARN("%s: start=%llu not aligned to h/w "
389 "logical block size %u of %s",
390 dm_device_name(ti->table->md),
391 (unsigned long long)start,
392 limits->logical_block_size, bdevname(bdev, b));
396 if (len & (logical_block_size_sectors - 1)) {
397 DMWARN("%s: len=%llu not aligned to h/w "
398 "logical block size %u of %s",
399 dm_device_name(ti->table->md),
400 (unsigned long long)len,
401 limits->logical_block_size, bdevname(bdev, b));
409 * This upgrades the mode on an already open dm_dev, being
410 * careful to leave things as they were if we fail to reopen the
411 * device and not to touch the existing bdev field in case
412 * it is accessed concurrently inside dm_table_any_congested().
414 static int upgrade_mode(struct dm_dev_internal *dd, fmode_t new_mode,
415 struct mapped_device *md)
418 struct dm_dev_internal dd_new, dd_old;
420 dd_new = dd_old = *dd;
422 dd_new.dm_dev.mode |= new_mode;
423 dd_new.dm_dev.bdev = NULL;
425 r = open_dev(&dd_new, dd->dm_dev.bdev->bd_dev, md);
429 dd->dm_dev.mode |= new_mode;
430 close_dev(&dd_old, md);
436 * Add a device to the list, or just increment the usage count if
437 * it's already present.
439 static int __table_get_device(struct dm_table *t, struct dm_target *ti,
440 const char *path, fmode_t mode, struct dm_dev **result)
443 dev_t uninitialized_var(dev);
444 struct dm_dev_internal *dd;
445 unsigned int major, minor;
449 if (sscanf(path, "%u:%u", &major, &minor) == 2) {
450 /* Extract the major/minor numbers */
451 dev = MKDEV(major, minor);
452 if (MAJOR(dev) != major || MINOR(dev) != minor)
455 /* convert the path to a device */
456 struct block_device *bdev = lookup_bdev(path);
459 return PTR_ERR(bdev);
464 dd = find_device(&t->devices, dev);
466 dd = kmalloc(sizeof(*dd), GFP_KERNEL);
470 dd->dm_dev.mode = mode;
471 dd->dm_dev.bdev = NULL;
473 if ((r = open_dev(dd, dev, t->md))) {
478 format_dev_t(dd->dm_dev.name, dev);
480 atomic_set(&dd->count, 0);
481 list_add(&dd->list, &t->devices);
483 } else if (dd->dm_dev.mode != (mode | dd->dm_dev.mode)) {
484 r = upgrade_mode(dd, mode, t->md);
488 atomic_inc(&dd->count);
490 *result = &dd->dm_dev;
494 int dm_set_device_limits(struct dm_target *ti, struct dm_dev *dev,
495 sector_t start, sector_t len, void *data)
497 struct queue_limits *limits = data;
498 struct block_device *bdev = dev->bdev;
499 struct request_queue *q = bdev_get_queue(bdev);
500 char b[BDEVNAME_SIZE];
503 DMWARN("%s: Cannot set limits for nonexistent device %s",
504 dm_device_name(ti->table->md), bdevname(bdev, b));
508 if (bdev_stack_limits(limits, bdev, start) < 0)
509 DMWARN("%s: adding target device %s caused an alignment inconsistency: "
510 "physical_block_size=%u, logical_block_size=%u, "
511 "alignment_offset=%u, start=%llu",
512 dm_device_name(ti->table->md), bdevname(bdev, b),
513 q->limits.physical_block_size,
514 q->limits.logical_block_size,
515 q->limits.alignment_offset,
516 (unsigned long long) start << SECTOR_SHIFT);
519 * Check if merge fn is supported.
520 * If not we'll force DM to use PAGE_SIZE or
521 * smaller I/O, just to be safe.
524 if (q->merge_bvec_fn && !ti->type->merge)
525 blk_limits_max_hw_sectors(limits,
526 (unsigned int) (PAGE_SIZE >> 9));
529 EXPORT_SYMBOL_GPL(dm_set_device_limits);
531 int dm_get_device(struct dm_target *ti, const char *path, fmode_t mode,
532 struct dm_dev **result)
534 return __table_get_device(ti->table, ti, path, mode, result);
539 * Decrement a devices use count and remove it if necessary.
541 void dm_put_device(struct dm_target *ti, struct dm_dev *d)
543 struct dm_dev_internal *dd = container_of(d, struct dm_dev_internal,
546 if (atomic_dec_and_test(&dd->count)) {
547 close_dev(dd, ti->table->md);
554 * Checks to see if the target joins onto the end of the table.
556 static int adjoin(struct dm_table *table, struct dm_target *ti)
558 struct dm_target *prev;
560 if (!table->num_targets)
563 prev = &table->targets[table->num_targets - 1];
564 return (ti->begin == (prev->begin + prev->len));
568 * Used to dynamically allocate the arg array.
570 static char **realloc_argv(unsigned *array_size, char **old_argv)
575 new_size = *array_size ? *array_size * 2 : 64;
576 argv = kmalloc(new_size * sizeof(*argv), GFP_KERNEL);
578 memcpy(argv, old_argv, *array_size * sizeof(*argv));
579 *array_size = new_size;
587 * Destructively splits up the argument list to pass to ctr.
589 int dm_split_args(int *argc, char ***argvp, char *input)
591 char *start, *end = input, *out, **argv = NULL;
592 unsigned array_size = 0;
601 argv = realloc_argv(&array_size, argv);
606 /* Skip whitespace */
607 start = skip_spaces(end);
610 break; /* success, we hit the end */
612 /* 'out' is used to remove any back-quotes */
615 /* Everything apart from '\0' can be quoted */
616 if (*end == '\\' && *(end + 1)) {
623 break; /* end of token */
628 /* have we already filled the array ? */
629 if ((*argc + 1) > array_size) {
630 argv = realloc_argv(&array_size, argv);
635 /* we know this is whitespace */
639 /* terminate the string and put it in the array */
650 * Impose necessary and sufficient conditions on a devices's table such
651 * that any incoming bio which respects its logical_block_size can be
652 * processed successfully. If it falls across the boundary between
653 * two or more targets, the size of each piece it gets split into must
654 * be compatible with the logical_block_size of the target processing it.
656 static int validate_hardware_logical_block_alignment(struct dm_table *table,
657 struct queue_limits *limits)
660 * This function uses arithmetic modulo the logical_block_size
661 * (in units of 512-byte sectors).
663 unsigned short device_logical_block_size_sects =
664 limits->logical_block_size >> SECTOR_SHIFT;
667 * Offset of the start of the next table entry, mod logical_block_size.
669 unsigned short next_target_start = 0;
672 * Given an aligned bio that extends beyond the end of a
673 * target, how many sectors must the next target handle?
675 unsigned short remaining = 0;
677 struct dm_target *uninitialized_var(ti);
678 struct queue_limits ti_limits;
682 * Check each entry in the table in turn.
684 while (i < dm_table_get_num_targets(table)) {
685 ti = dm_table_get_target(table, i++);
687 blk_set_default_limits(&ti_limits);
689 /* combine all target devices' limits */
690 if (ti->type->iterate_devices)
691 ti->type->iterate_devices(ti, dm_set_device_limits,
695 * If the remaining sectors fall entirely within this
696 * table entry are they compatible with its logical_block_size?
698 if (remaining < ti->len &&
699 remaining & ((ti_limits.logical_block_size >>
704 (unsigned short) ((next_target_start + ti->len) &
705 (device_logical_block_size_sects - 1));
706 remaining = next_target_start ?
707 device_logical_block_size_sects - next_target_start : 0;
711 DMWARN("%s: table line %u (start sect %llu len %llu) "
712 "not aligned to h/w logical block size %u",
713 dm_device_name(table->md), i,
714 (unsigned long long) ti->begin,
715 (unsigned long long) ti->len,
716 limits->logical_block_size);
723 int dm_table_add_target(struct dm_table *t, const char *type,
724 sector_t start, sector_t len, char *params)
726 int r = -EINVAL, argc;
728 struct dm_target *tgt;
730 if ((r = check_space(t)))
733 tgt = t->targets + t->num_targets;
734 memset(tgt, 0, sizeof(*tgt));
737 DMERR("%s: zero-length target", dm_device_name(t->md));
741 tgt->type = dm_get_target_type(type);
743 DMERR("%s: %s: unknown target type", dm_device_name(t->md),
751 tgt->error = "Unknown error";
754 * Does this target adjoin the previous one ?
756 if (!adjoin(t, tgt)) {
757 tgt->error = "Gap in table";
762 r = dm_split_args(&argc, &argv, params);
764 tgt->error = "couldn't split parameters (insufficient memory)";
768 r = tgt->type->ctr(tgt, argc, argv);
773 t->highs[t->num_targets++] = tgt->begin + tgt->len - 1;
775 if (!tgt->num_discard_requests)
776 t->discards_supported = 0;
781 DMERR("%s: %s: %s", dm_device_name(t->md), type, tgt->error);
782 dm_put_target_type(tgt->type);
786 static int dm_table_set_type(struct dm_table *t)
789 unsigned bio_based = 0, request_based = 0;
790 struct dm_target *tgt;
791 struct dm_dev_internal *dd;
792 struct list_head *devices;
794 for (i = 0; i < t->num_targets; i++) {
795 tgt = t->targets + i;
796 if (dm_target_request_based(tgt))
801 if (bio_based && request_based) {
802 DMWARN("Inconsistent table: different target types"
803 " can't be mixed up");
809 /* We must use this table as bio-based */
810 t->type = DM_TYPE_BIO_BASED;
814 BUG_ON(!request_based); /* No targets in this table */
816 /* Non-request-stackable devices can't be used for request-based dm */
817 devices = dm_table_get_devices(t);
818 list_for_each_entry(dd, devices, list) {
819 if (!blk_queue_stackable(bdev_get_queue(dd->dm_dev.bdev))) {
820 DMWARN("table load rejected: including"
821 " non-request-stackable devices");
827 * Request-based dm supports only tables that have a single target now.
828 * To support multiple targets, request splitting support is needed,
829 * and that needs lots of changes in the block-layer.
830 * (e.g. request completion process for partial completion.)
832 if (t->num_targets > 1) {
833 DMWARN("Request-based dm doesn't support multiple targets yet");
837 t->type = DM_TYPE_REQUEST_BASED;
842 unsigned dm_table_get_type(struct dm_table *t)
847 bool dm_table_request_based(struct dm_table *t)
849 return dm_table_get_type(t) == DM_TYPE_REQUEST_BASED;
852 int dm_table_alloc_md_mempools(struct dm_table *t)
854 unsigned type = dm_table_get_type(t);
856 if (unlikely(type == DM_TYPE_NONE)) {
857 DMWARN("no table type is set, can't allocate mempools");
861 t->mempools = dm_alloc_md_mempools(type);
868 void dm_table_free_md_mempools(struct dm_table *t)
870 dm_free_md_mempools(t->mempools);
874 struct dm_md_mempools *dm_table_get_md_mempools(struct dm_table *t)
879 static int setup_indexes(struct dm_table *t)
882 unsigned int total = 0;
885 /* allocate the space for *all* the indexes */
886 for (i = t->depth - 2; i >= 0; i--) {
887 t->counts[i] = dm_div_up(t->counts[i + 1], CHILDREN_PER_NODE);
888 total += t->counts[i];
891 indexes = (sector_t *) dm_vcalloc(total, (unsigned long) NODE_SIZE);
895 /* set up internal nodes, bottom-up */
896 for (i = t->depth - 2; i >= 0; i--) {
897 t->index[i] = indexes;
898 indexes += (KEYS_PER_NODE * t->counts[i]);
899 setup_btree_index(i, t);
906 * Builds the btree to index the map.
908 static int dm_table_build_index(struct dm_table *t)
911 unsigned int leaf_nodes;
913 /* how many indexes will the btree have ? */
914 leaf_nodes = dm_div_up(t->num_targets, KEYS_PER_NODE);
915 t->depth = 1 + int_log(leaf_nodes, CHILDREN_PER_NODE);
917 /* leaf layer has already been set up */
918 t->counts[t->depth - 1] = leaf_nodes;
919 t->index[t->depth - 1] = t->highs;
922 r = setup_indexes(t);
928 * Register the mapped device for blk_integrity support if
929 * the underlying devices support it.
931 static int dm_table_prealloc_integrity(struct dm_table *t, struct mapped_device *md)
933 struct list_head *devices = dm_table_get_devices(t);
934 struct dm_dev_internal *dd;
936 list_for_each_entry(dd, devices, list)
937 if (bdev_get_integrity(dd->dm_dev.bdev))
938 return blk_integrity_register(dm_disk(md), NULL);
944 * Prepares the table for use by building the indices,
945 * setting the type, and allocating mempools.
947 int dm_table_complete(struct dm_table *t)
951 r = dm_table_set_type(t);
953 DMERR("unable to set table type");
957 r = dm_table_build_index(t);
959 DMERR("unable to build btrees");
963 r = dm_table_prealloc_integrity(t, t->md);
965 DMERR("could not register integrity profile.");
969 r = dm_table_alloc_md_mempools(t);
971 DMERR("unable to allocate mempools");
976 static DEFINE_MUTEX(_event_lock);
977 void dm_table_event_callback(struct dm_table *t,
978 void (*fn)(void *), void *context)
980 mutex_lock(&_event_lock);
982 t->event_context = context;
983 mutex_unlock(&_event_lock);
986 void dm_table_event(struct dm_table *t)
989 * You can no longer call dm_table_event() from interrupt
990 * context, use a bottom half instead.
992 BUG_ON(in_interrupt());
994 mutex_lock(&_event_lock);
996 t->event_fn(t->event_context);
997 mutex_unlock(&_event_lock);
1000 sector_t dm_table_get_size(struct dm_table *t)
1002 return t->num_targets ? (t->highs[t->num_targets - 1] + 1) : 0;
1005 struct dm_target *dm_table_get_target(struct dm_table *t, unsigned int index)
1007 if (index >= t->num_targets)
1010 return t->targets + index;
1014 * Search the btree for the correct target.
1016 * Caller should check returned pointer with dm_target_is_valid()
1017 * to trap I/O beyond end of device.
1019 struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector)
1021 unsigned int l, n = 0, k = 0;
1024 for (l = 0; l < t->depth; l++) {
1025 n = get_child(n, k);
1026 node = get_node(t, l, n);
1028 for (k = 0; k < KEYS_PER_NODE; k++)
1029 if (node[k] >= sector)
1033 return &t->targets[(KEYS_PER_NODE * n) + k];
1037 * Establish the new table's queue_limits and validate them.
1039 int dm_calculate_queue_limits(struct dm_table *table,
1040 struct queue_limits *limits)
1042 struct dm_target *uninitialized_var(ti);
1043 struct queue_limits ti_limits;
1046 blk_set_default_limits(limits);
1048 while (i < dm_table_get_num_targets(table)) {
1049 blk_set_default_limits(&ti_limits);
1051 ti = dm_table_get_target(table, i++);
1053 if (!ti->type->iterate_devices)
1054 goto combine_limits;
1057 * Combine queue limits of all the devices this target uses.
1059 ti->type->iterate_devices(ti, dm_set_device_limits,
1062 /* Set I/O hints portion of queue limits */
1063 if (ti->type->io_hints)
1064 ti->type->io_hints(ti, &ti_limits);
1067 * Check each device area is consistent with the target's
1068 * overall queue limits.
1070 if (ti->type->iterate_devices(ti, device_area_is_invalid,
1076 * Merge this target's queue limits into the overall limits
1079 if (blk_stack_limits(limits, &ti_limits, 0) < 0)
1080 DMWARN("%s: adding target device "
1081 "(start sect %llu len %llu) "
1082 "caused an alignment inconsistency",
1083 dm_device_name(table->md),
1084 (unsigned long long) ti->begin,
1085 (unsigned long long) ti->len);
1088 return validate_hardware_logical_block_alignment(table, limits);
1092 * Set the integrity profile for this device if all devices used have
1093 * matching profiles.
1095 static void dm_table_set_integrity(struct dm_table *t)
1097 struct list_head *devices = dm_table_get_devices(t);
1098 struct dm_dev_internal *prev = NULL, *dd = NULL;
1100 if (!blk_get_integrity(dm_disk(t->md)))
1103 list_for_each_entry(dd, devices, list) {
1105 blk_integrity_compare(prev->dm_dev.bdev->bd_disk,
1106 dd->dm_dev.bdev->bd_disk) < 0) {
1107 DMWARN("%s: integrity not set: %s and %s mismatch",
1108 dm_device_name(t->md),
1109 prev->dm_dev.bdev->bd_disk->disk_name,
1110 dd->dm_dev.bdev->bd_disk->disk_name);
1116 if (!prev || !bdev_get_integrity(prev->dm_dev.bdev))
1119 blk_integrity_register(dm_disk(t->md),
1120 bdev_get_integrity(prev->dm_dev.bdev));
1125 blk_integrity_register(dm_disk(t->md), NULL);
1130 void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
1131 struct queue_limits *limits)
1134 * Copy table's limits to the DM device's request_queue
1136 q->limits = *limits;
1138 if (!dm_table_supports_discards(t))
1139 queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, q);
1141 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q);
1143 dm_table_set_integrity(t);
1146 * QUEUE_FLAG_STACKABLE must be set after all queue settings are
1147 * visible to other CPUs because, once the flag is set, incoming bios
1148 * are processed by request-based dm, which refers to the queue
1150 * Until the flag set, bios are passed to bio-based dm and queued to
1151 * md->deferred where queue settings are not needed yet.
1152 * Those bios are passed to request-based dm at the resume time.
1155 if (dm_table_request_based(t))
1156 queue_flag_set_unlocked(QUEUE_FLAG_STACKABLE, q);
1159 unsigned int dm_table_get_num_targets(struct dm_table *t)
1161 return t->num_targets;
1164 struct list_head *dm_table_get_devices(struct dm_table *t)
1169 fmode_t dm_table_get_mode(struct dm_table *t)
1174 static void suspend_targets(struct dm_table *t, unsigned postsuspend)
1176 int i = t->num_targets;
1177 struct dm_target *ti = t->targets;
1181 if (ti->type->postsuspend)
1182 ti->type->postsuspend(ti);
1183 } else if (ti->type->presuspend)
1184 ti->type->presuspend(ti);
1190 void dm_table_presuspend_targets(struct dm_table *t)
1195 suspend_targets(t, 0);
1198 void dm_table_postsuspend_targets(struct dm_table *t)
1203 suspend_targets(t, 1);
1206 int dm_table_resume_targets(struct dm_table *t)
1210 for (i = 0; i < t->num_targets; i++) {
1211 struct dm_target *ti = t->targets + i;
1213 if (!ti->type->preresume)
1216 r = ti->type->preresume(ti);
1221 for (i = 0; i < t->num_targets; i++) {
1222 struct dm_target *ti = t->targets + i;
1224 if (ti->type->resume)
1225 ti->type->resume(ti);
1231 void dm_table_add_target_callbacks(struct dm_table *t, struct dm_target_callbacks *cb)
1233 list_add(&cb->list, &t->target_callbacks);
1235 EXPORT_SYMBOL_GPL(dm_table_add_target_callbacks);
1237 int dm_table_any_congested(struct dm_table *t, int bdi_bits)
1239 struct dm_dev_internal *dd;
1240 struct list_head *devices = dm_table_get_devices(t);
1241 struct dm_target_callbacks *cb;
1244 list_for_each_entry(dd, devices, list) {
1245 struct request_queue *q = bdev_get_queue(dd->dm_dev.bdev);
1246 char b[BDEVNAME_SIZE];
1249 r |= bdi_congested(&q->backing_dev_info, bdi_bits);
1251 DMWARN_LIMIT("%s: any_congested: nonexistent device %s",
1252 dm_device_name(t->md),
1253 bdevname(dd->dm_dev.bdev, b));
1256 list_for_each_entry(cb, &t->target_callbacks, list)
1257 if (cb->congested_fn)
1258 r |= cb->congested_fn(cb, bdi_bits);
1263 int dm_table_any_busy_target(struct dm_table *t)
1266 struct dm_target *ti;
1268 for (i = 0; i < t->num_targets; i++) {
1269 ti = t->targets + i;
1270 if (ti->type->busy && ti->type->busy(ti))
1277 void dm_table_unplug_all(struct dm_table *t)
1279 struct dm_dev_internal *dd;
1280 struct list_head *devices = dm_table_get_devices(t);
1281 struct dm_target_callbacks *cb;
1283 list_for_each_entry(dd, devices, list) {
1284 struct request_queue *q = bdev_get_queue(dd->dm_dev.bdev);
1285 char b[BDEVNAME_SIZE];
1290 DMWARN_LIMIT("%s: Cannot unplug nonexistent device %s",
1291 dm_device_name(t->md),
1292 bdevname(dd->dm_dev.bdev, b));
1295 list_for_each_entry(cb, &t->target_callbacks, list)
1300 struct mapped_device *dm_table_get_md(struct dm_table *t)
1305 static int device_discard_capable(struct dm_target *ti, struct dm_dev *dev,
1306 sector_t start, sector_t len, void *data)
1308 struct request_queue *q = bdev_get_queue(dev->bdev);
1310 return q && blk_queue_discard(q);
1313 bool dm_table_supports_discards(struct dm_table *t)
1315 struct dm_target *ti;
1318 if (!t->discards_supported)
1322 * Ensure that at least one underlying device supports discards.
1323 * t->devices includes internal dm devices such as mirror logs
1324 * so we need to use iterate_devices here, which targets
1325 * supporting discard must provide.
1327 while (i < dm_table_get_num_targets(t)) {
1328 ti = dm_table_get_target(t, i++);
1330 if (ti->type->iterate_devices &&
1331 ti->type->iterate_devices(ti, device_discard_capable, NULL))
1338 EXPORT_SYMBOL(dm_vcalloc);
1339 EXPORT_SYMBOL(dm_get_device);
1340 EXPORT_SYMBOL(dm_put_device);
1341 EXPORT_SYMBOL(dm_table_event);
1342 EXPORT_SYMBOL(dm_table_get_size);
1343 EXPORT_SYMBOL(dm_table_get_mode);
1344 EXPORT_SYMBOL(dm_table_get_md);
1345 EXPORT_SYMBOL(dm_table_put);
1346 EXPORT_SYMBOL(dm_table_get);
1347 EXPORT_SYMBOL(dm_table_unplug_all);