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>
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 struct target_type *immutable_target_type;
58 unsigned integrity_supported:1;
62 * Indicates the rw permissions for the new logical
63 * device. This should be a combination of FMODE_READ
68 /* a list of devices used by this table */
69 struct list_head devices;
71 /* events get handed up using this callback */
72 void (*event_fn)(void *);
75 struct dm_md_mempools *mempools;
77 struct list_head target_callbacks;
81 * Similar to ceiling(log_size(n))
83 static unsigned int int_log(unsigned int n, unsigned int base)
88 n = dm_div_up(n, base);
96 * Calculate the index of the child node of the n'th node k'th key.
98 static inline unsigned int get_child(unsigned int n, unsigned int k)
100 return (n * CHILDREN_PER_NODE) + k;
104 * Return the n'th node of level l from table t.
106 static inline sector_t *get_node(struct dm_table *t,
107 unsigned int l, unsigned int n)
109 return t->index[l] + (n * KEYS_PER_NODE);
113 * Return the highest key that you could lookup from the n'th
114 * node on level l of the btree.
116 static sector_t high(struct dm_table *t, unsigned int l, unsigned int n)
118 for (; l < t->depth - 1; l++)
119 n = get_child(n, CHILDREN_PER_NODE - 1);
121 if (n >= t->counts[l])
122 return (sector_t) - 1;
124 return get_node(t, l, n)[KEYS_PER_NODE - 1];
128 * Fills in a level of the btree based on the highs of the level
131 static int setup_btree_index(unsigned int l, struct dm_table *t)
136 for (n = 0U; n < t->counts[l]; n++) {
137 node = get_node(t, l, n);
139 for (k = 0U; k < KEYS_PER_NODE; k++)
140 node[k] = high(t, l + 1, get_child(n, k));
146 void *dm_vcalloc(unsigned long nmemb, unsigned long elem_size)
152 * Check that we're not going to overflow.
154 if (nmemb > (ULONG_MAX / elem_size))
157 size = nmemb * elem_size;
158 addr = vzalloc(size);
162 EXPORT_SYMBOL(dm_vcalloc);
165 * highs, and targets are managed as dynamic arrays during a
168 static int alloc_targets(struct dm_table *t, unsigned int num)
171 struct dm_target *n_targets;
172 int n = t->num_targets;
175 * Allocate both the target array and offset array at once.
176 * Append an empty entry to catch sectors beyond the end of
179 n_highs = (sector_t *) dm_vcalloc(num + 1, sizeof(struct dm_target) +
184 n_targets = (struct dm_target *) (n_highs + num);
187 memcpy(n_highs, t->highs, sizeof(*n_highs) * n);
188 memcpy(n_targets, t->targets, sizeof(*n_targets) * n);
191 memset(n_highs + n, -1, sizeof(*n_highs) * (num - n));
194 t->num_allocated = num;
196 t->targets = n_targets;
201 int dm_table_create(struct dm_table **result, fmode_t mode,
202 unsigned num_targets, struct mapped_device *md)
204 struct dm_table *t = kzalloc(sizeof(*t), GFP_KERNEL);
209 INIT_LIST_HEAD(&t->devices);
210 INIT_LIST_HEAD(&t->target_callbacks);
211 atomic_set(&t->holders, 0);
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 free_devices(&t->devices);
273 dm_free_md_mempools(t->mempools);
278 void dm_table_get(struct dm_table *t)
280 atomic_inc(&t->holders);
282 EXPORT_SYMBOL(dm_table_get);
284 void dm_table_put(struct dm_table *t)
289 smp_mb__before_atomic_dec();
290 atomic_dec(&t->holders);
292 EXPORT_SYMBOL(dm_table_put);
295 * Checks to see if we need to extend highs or targets.
297 static inline int check_space(struct dm_table *t)
299 if (t->num_targets >= t->num_allocated)
300 return alloc_targets(t, t->num_allocated * 2);
306 * See if we've already got a device in the list.
308 static struct dm_dev_internal *find_device(struct list_head *l, dev_t dev)
310 struct dm_dev_internal *dd;
312 list_for_each_entry (dd, l, list)
313 if (dd->dm_dev.bdev->bd_dev == dev)
320 * Open a device so we can use it as a map destination.
322 static int open_dev(struct dm_dev_internal *d, dev_t dev,
323 struct mapped_device *md)
325 static char *_claim_ptr = "I belong to device-mapper";
326 struct block_device *bdev;
330 BUG_ON(d->dm_dev.bdev);
332 bdev = blkdev_get_by_dev(dev, d->dm_dev.mode | FMODE_EXCL, _claim_ptr);
334 return PTR_ERR(bdev);
336 r = bd_link_disk_holder(bdev, dm_disk(md));
338 blkdev_put(bdev, d->dm_dev.mode | FMODE_EXCL);
342 d->dm_dev.bdev = bdev;
347 * Close a device that we've been using.
349 static void close_dev(struct dm_dev_internal *d, struct mapped_device *md)
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;
360 * If possible, this checks an area of a destination device is invalid.
362 static int device_area_is_invalid(struct dm_target *ti, struct dm_dev *dev,
363 sector_t start, sector_t len, void *data)
365 struct request_queue *q;
366 struct queue_limits *limits = data;
367 struct block_device *bdev = dev->bdev;
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];
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.
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);
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);
403 if (logical_block_size_sectors <= 1)
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));
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));
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().
433 static int upgrade_mode(struct dm_dev_internal *dd, fmode_t new_mode,
434 struct mapped_device *md)
437 struct dm_dev_internal dd_new, dd_old;
439 dd_new = dd_old = *dd;
441 dd_new.dm_dev.mode |= new_mode;
442 dd_new.dm_dev.bdev = NULL;
444 r = open_dev(&dd_new, dd->dm_dev.bdev->bd_dev, md);
448 dd->dm_dev.mode |= new_mode;
449 close_dev(&dd_old, md);
455 * Add a device to the list, or just increment the usage count if
456 * it's already present.
458 int dm_get_device(struct dm_target *ti, const char *path, fmode_t mode,
459 struct dm_dev **result)
462 dev_t uninitialized_var(dev);
463 struct dm_dev_internal *dd;
464 unsigned int major, minor;
465 struct dm_table *t = ti->table;
469 if (sscanf(path, "%u:%u", &major, &minor) == 2) {
470 /* Extract the major/minor numbers */
471 dev = MKDEV(major, minor);
472 if (MAJOR(dev) != major || MINOR(dev) != minor)
475 /* convert the path to a device */
476 struct block_device *bdev = lookup_bdev(path);
479 return PTR_ERR(bdev);
484 dd = find_device(&t->devices, dev);
486 dd = kmalloc(sizeof(*dd), GFP_KERNEL);
490 dd->dm_dev.mode = mode;
491 dd->dm_dev.bdev = NULL;
493 if ((r = open_dev(dd, dev, t->md))) {
498 format_dev_t(dd->dm_dev.name, dev);
500 atomic_set(&dd->count, 0);
501 list_add(&dd->list, &t->devices);
503 } else if (dd->dm_dev.mode != (mode | dd->dm_dev.mode)) {
504 r = upgrade_mode(dd, mode, t->md);
508 atomic_inc(&dd->count);
510 *result = &dd->dm_dev;
513 EXPORT_SYMBOL(dm_get_device);
515 int dm_set_device_limits(struct dm_target *ti, struct dm_dev *dev,
516 sector_t start, sector_t len, void *data)
518 struct queue_limits *limits = data;
519 struct block_device *bdev = dev->bdev;
520 struct request_queue *q = bdev_get_queue(bdev);
521 char b[BDEVNAME_SIZE];
524 DMWARN("%s: Cannot set limits for nonexistent device %s",
525 dm_device_name(ti->table->md), bdevname(bdev, b));
529 if (bdev_stack_limits(limits, bdev, start) < 0)
530 DMWARN("%s: adding target device %s caused an alignment inconsistency: "
531 "physical_block_size=%u, logical_block_size=%u, "
532 "alignment_offset=%u, start=%llu",
533 dm_device_name(ti->table->md), bdevname(bdev, b),
534 q->limits.physical_block_size,
535 q->limits.logical_block_size,
536 q->limits.alignment_offset,
537 (unsigned long long) start << SECTOR_SHIFT);
540 * Check if merge fn is supported.
541 * If not we'll force DM to use PAGE_SIZE or
542 * smaller I/O, just to be safe.
544 if (dm_queue_merge_is_compulsory(q) && !ti->type->merge)
545 blk_limits_max_hw_sectors(limits,
546 (unsigned int) (PAGE_SIZE >> 9));
549 EXPORT_SYMBOL_GPL(dm_set_device_limits);
552 * Decrement a device's use count and remove it if necessary.
554 void dm_put_device(struct dm_target *ti, struct dm_dev *d)
556 struct dm_dev_internal *dd = container_of(d, struct dm_dev_internal,
559 if (atomic_dec_and_test(&dd->count)) {
560 close_dev(dd, ti->table->md);
565 EXPORT_SYMBOL(dm_put_device);
568 * Checks to see if the target joins onto the end of the table.
570 static int adjoin(struct dm_table *table, struct dm_target *ti)
572 struct dm_target *prev;
574 if (!table->num_targets)
577 prev = &table->targets[table->num_targets - 1];
578 return (ti->begin == (prev->begin + prev->len));
582 * Used to dynamically allocate the arg array.
584 static char **realloc_argv(unsigned *array_size, char **old_argv)
589 new_size = *array_size ? *array_size * 2 : 64;
590 argv = kmalloc(new_size * sizeof(*argv), GFP_KERNEL);
592 memcpy(argv, old_argv, *array_size * sizeof(*argv));
593 *array_size = new_size;
601 * Destructively splits up the argument list to pass to ctr.
603 int dm_split_args(int *argc, char ***argvp, char *input)
605 char *start, *end = input, *out, **argv = NULL;
606 unsigned array_size = 0;
615 argv = realloc_argv(&array_size, argv);
620 /* Skip whitespace */
621 start = skip_spaces(end);
624 break; /* success, we hit the end */
626 /* 'out' is used to remove any back-quotes */
629 /* Everything apart from '\0' can be quoted */
630 if (*end == '\\' && *(end + 1)) {
637 break; /* end of token */
642 /* have we already filled the array ? */
643 if ((*argc + 1) > array_size) {
644 argv = realloc_argv(&array_size, argv);
649 /* we know this is whitespace */
653 /* terminate the string and put it in the array */
664 * Impose necessary and sufficient conditions on a devices's table such
665 * that any incoming bio which respects its logical_block_size can be
666 * processed successfully. If it falls across the boundary between
667 * two or more targets, the size of each piece it gets split into must
668 * be compatible with the logical_block_size of the target processing it.
670 static int validate_hardware_logical_block_alignment(struct dm_table *table,
671 struct queue_limits *limits)
674 * This function uses arithmetic modulo the logical_block_size
675 * (in units of 512-byte sectors).
677 unsigned short device_logical_block_size_sects =
678 limits->logical_block_size >> SECTOR_SHIFT;
681 * Offset of the start of the next table entry, mod logical_block_size.
683 unsigned short next_target_start = 0;
686 * Given an aligned bio that extends beyond the end of a
687 * target, how many sectors must the next target handle?
689 unsigned short remaining = 0;
691 struct dm_target *uninitialized_var(ti);
692 struct queue_limits ti_limits;
696 * Check each entry in the table in turn.
698 while (i < dm_table_get_num_targets(table)) {
699 ti = dm_table_get_target(table, i++);
701 blk_set_stacking_limits(&ti_limits);
703 /* combine all target devices' limits */
704 if (ti->type->iterate_devices)
705 ti->type->iterate_devices(ti, dm_set_device_limits,
709 * If the remaining sectors fall entirely within this
710 * table entry are they compatible with its logical_block_size?
712 if (remaining < ti->len &&
713 remaining & ((ti_limits.logical_block_size >>
718 (unsigned short) ((next_target_start + ti->len) &
719 (device_logical_block_size_sects - 1));
720 remaining = next_target_start ?
721 device_logical_block_size_sects - next_target_start : 0;
725 DMWARN("%s: table line %u (start sect %llu len %llu) "
726 "not aligned to h/w logical block size %u",
727 dm_device_name(table->md), i,
728 (unsigned long long) ti->begin,
729 (unsigned long long) ti->len,
730 limits->logical_block_size);
737 int dm_table_add_target(struct dm_table *t, const char *type,
738 sector_t start, sector_t len, char *params)
740 int r = -EINVAL, argc;
742 struct dm_target *tgt;
745 DMERR("%s: target type %s must appear alone in table",
746 dm_device_name(t->md), t->targets->type->name);
750 if ((r = check_space(t)))
753 tgt = t->targets + t->num_targets;
754 memset(tgt, 0, sizeof(*tgt));
757 DMERR("%s: zero-length target", dm_device_name(t->md));
761 tgt->type = dm_get_target_type(type);
763 DMERR("%s: %s: unknown target type", dm_device_name(t->md),
768 if (dm_target_needs_singleton(tgt->type)) {
769 if (t->num_targets) {
770 DMERR("%s: target type %s must appear alone in table",
771 dm_device_name(t->md), type);
777 if (dm_target_always_writeable(tgt->type) && !(t->mode & FMODE_WRITE)) {
778 DMERR("%s: target type %s may not be included in read-only tables",
779 dm_device_name(t->md), type);
783 if (t->immutable_target_type) {
784 if (t->immutable_target_type != tgt->type) {
785 DMERR("%s: immutable target type %s cannot be mixed with other target types",
786 dm_device_name(t->md), t->immutable_target_type->name);
789 } else if (dm_target_is_immutable(tgt->type)) {
790 if (t->num_targets) {
791 DMERR("%s: immutable target type %s cannot be mixed with other target types",
792 dm_device_name(t->md), tgt->type->name);
795 t->immutable_target_type = tgt->type;
801 tgt->error = "Unknown error";
804 * Does this target adjoin the previous one ?
806 if (!adjoin(t, tgt)) {
807 tgt->error = "Gap in table";
812 r = dm_split_args(&argc, &argv, params);
814 tgt->error = "couldn't split parameters (insufficient memory)";
818 r = tgt->type->ctr(tgt, argc, argv);
823 t->highs[t->num_targets++] = tgt->begin + tgt->len - 1;
825 if (!tgt->num_discard_requests && tgt->discards_supported)
826 DMWARN("%s: %s: ignoring discards_supported because num_discard_requests is zero.",
827 dm_device_name(t->md), type);
832 DMERR("%s: %s: %s", dm_device_name(t->md), type, tgt->error);
833 dm_put_target_type(tgt->type);
838 * Target argument parsing helpers.
840 static int validate_next_arg(struct dm_arg *arg, struct dm_arg_set *arg_set,
841 unsigned *value, char **error, unsigned grouped)
843 const char *arg_str = dm_shift_arg(arg_set);
846 (sscanf(arg_str, "%u", value) != 1) ||
847 (*value < arg->min) ||
848 (*value > arg->max) ||
849 (grouped && arg_set->argc < *value)) {
857 int dm_read_arg(struct dm_arg *arg, struct dm_arg_set *arg_set,
858 unsigned *value, char **error)
860 return validate_next_arg(arg, arg_set, value, error, 0);
862 EXPORT_SYMBOL(dm_read_arg);
864 int dm_read_arg_group(struct dm_arg *arg, struct dm_arg_set *arg_set,
865 unsigned *value, char **error)
867 return validate_next_arg(arg, arg_set, value, error, 1);
869 EXPORT_SYMBOL(dm_read_arg_group);
871 const char *dm_shift_arg(struct dm_arg_set *as)
884 EXPORT_SYMBOL(dm_shift_arg);
886 void dm_consume_args(struct dm_arg_set *as, unsigned num_args)
888 BUG_ON(as->argc < num_args);
889 as->argc -= num_args;
890 as->argv += num_args;
892 EXPORT_SYMBOL(dm_consume_args);
894 static int dm_table_set_type(struct dm_table *t)
897 unsigned bio_based = 0, request_based = 0;
898 struct dm_target *tgt;
899 struct dm_dev_internal *dd;
900 struct list_head *devices;
902 for (i = 0; i < t->num_targets; i++) {
903 tgt = t->targets + i;
904 if (dm_target_request_based(tgt))
909 if (bio_based && request_based) {
910 DMWARN("Inconsistent table: different target types"
911 " can't be mixed up");
917 /* We must use this table as bio-based */
918 t->type = DM_TYPE_BIO_BASED;
922 BUG_ON(!request_based); /* No targets in this table */
924 /* Non-request-stackable devices can't be used for request-based dm */
925 devices = dm_table_get_devices(t);
926 list_for_each_entry(dd, devices, list) {
927 if (!blk_queue_stackable(bdev_get_queue(dd->dm_dev.bdev))) {
928 DMWARN("table load rejected: including"
929 " non-request-stackable devices");
935 * Request-based dm supports only tables that have a single target now.
936 * To support multiple targets, request splitting support is needed,
937 * and that needs lots of changes in the block-layer.
938 * (e.g. request completion process for partial completion.)
940 if (t->num_targets > 1) {
941 DMWARN("Request-based dm doesn't support multiple targets yet");
945 t->type = DM_TYPE_REQUEST_BASED;
950 unsigned dm_table_get_type(struct dm_table *t)
955 struct target_type *dm_table_get_immutable_target_type(struct dm_table *t)
957 return t->immutable_target_type;
960 bool dm_table_request_based(struct dm_table *t)
962 return dm_table_get_type(t) == DM_TYPE_REQUEST_BASED;
965 int dm_table_alloc_md_mempools(struct dm_table *t)
967 unsigned type = dm_table_get_type(t);
969 if (unlikely(type == DM_TYPE_NONE)) {
970 DMWARN("no table type is set, can't allocate mempools");
974 t->mempools = dm_alloc_md_mempools(type, t->integrity_supported);
981 void dm_table_free_md_mempools(struct dm_table *t)
983 dm_free_md_mempools(t->mempools);
987 struct dm_md_mempools *dm_table_get_md_mempools(struct dm_table *t)
992 static int setup_indexes(struct dm_table *t)
995 unsigned int total = 0;
998 /* allocate the space for *all* the indexes */
999 for (i = t->depth - 2; i >= 0; i--) {
1000 t->counts[i] = dm_div_up(t->counts[i + 1], CHILDREN_PER_NODE);
1001 total += t->counts[i];
1004 indexes = (sector_t *) dm_vcalloc(total, (unsigned long) NODE_SIZE);
1008 /* set up internal nodes, bottom-up */
1009 for (i = t->depth - 2; i >= 0; i--) {
1010 t->index[i] = indexes;
1011 indexes += (KEYS_PER_NODE * t->counts[i]);
1012 setup_btree_index(i, t);
1019 * Builds the btree to index the map.
1021 static int dm_table_build_index(struct dm_table *t)
1024 unsigned int leaf_nodes;
1026 /* how many indexes will the btree have ? */
1027 leaf_nodes = dm_div_up(t->num_targets, KEYS_PER_NODE);
1028 t->depth = 1 + int_log(leaf_nodes, CHILDREN_PER_NODE);
1030 /* leaf layer has already been set up */
1031 t->counts[t->depth - 1] = leaf_nodes;
1032 t->index[t->depth - 1] = t->highs;
1035 r = setup_indexes(t);
1041 * Get a disk whose integrity profile reflects the table's profile.
1042 * If %match_all is true, all devices' profiles must match.
1043 * If %match_all is false, all devices must at least have an
1044 * allocated integrity profile; but uninitialized is ok.
1045 * Returns NULL if integrity support was inconsistent or unavailable.
1047 static struct gendisk * dm_table_get_integrity_disk(struct dm_table *t,
1050 struct list_head *devices = dm_table_get_devices(t);
1051 struct dm_dev_internal *dd = NULL;
1052 struct gendisk *prev_disk = NULL, *template_disk = NULL;
1054 list_for_each_entry(dd, devices, list) {
1055 template_disk = dd->dm_dev.bdev->bd_disk;
1056 if (!blk_get_integrity(template_disk))
1058 if (!match_all && !blk_integrity_is_initialized(template_disk))
1059 continue; /* skip uninitialized profiles */
1060 else if (prev_disk &&
1061 blk_integrity_compare(prev_disk, template_disk) < 0)
1063 prev_disk = template_disk;
1066 return template_disk;
1070 DMWARN("%s: integrity not set: %s and %s profile mismatch",
1071 dm_device_name(t->md),
1072 prev_disk->disk_name,
1073 template_disk->disk_name);
1078 * Register the mapped device for blk_integrity support if
1079 * the underlying devices have an integrity profile. But all devices
1080 * may not have matching profiles (checking all devices isn't reliable
1081 * during table load because this table may use other DM device(s) which
1082 * must be resumed before they will have an initialized integity profile).
1083 * Stacked DM devices force a 2 stage integrity profile validation:
1084 * 1 - during load, validate all initialized integrity profiles match
1085 * 2 - during resume, validate all integrity profiles match
1087 static int dm_table_prealloc_integrity(struct dm_table *t, struct mapped_device *md)
1089 struct gendisk *template_disk = NULL;
1091 template_disk = dm_table_get_integrity_disk(t, false);
1095 if (!blk_integrity_is_initialized(dm_disk(md))) {
1096 t->integrity_supported = 1;
1097 return blk_integrity_register(dm_disk(md), NULL);
1101 * If DM device already has an initalized integrity
1102 * profile the new profile should not conflict.
1104 if (blk_integrity_is_initialized(template_disk) &&
1105 blk_integrity_compare(dm_disk(md), template_disk) < 0) {
1106 DMWARN("%s: conflict with existing integrity profile: "
1107 "%s profile mismatch",
1108 dm_device_name(t->md),
1109 template_disk->disk_name);
1113 /* Preserve existing initialized integrity profile */
1114 t->integrity_supported = 1;
1119 * Prepares the table for use by building the indices,
1120 * setting the type, and allocating mempools.
1122 int dm_table_complete(struct dm_table *t)
1126 r = dm_table_set_type(t);
1128 DMERR("unable to set table type");
1132 r = dm_table_build_index(t);
1134 DMERR("unable to build btrees");
1138 r = dm_table_prealloc_integrity(t, t->md);
1140 DMERR("could not register integrity profile.");
1144 r = dm_table_alloc_md_mempools(t);
1146 DMERR("unable to allocate mempools");
1151 static DEFINE_MUTEX(_event_lock);
1152 void dm_table_event_callback(struct dm_table *t,
1153 void (*fn)(void *), void *context)
1155 mutex_lock(&_event_lock);
1157 t->event_context = context;
1158 mutex_unlock(&_event_lock);
1161 void dm_table_event(struct dm_table *t)
1164 * You can no longer call dm_table_event() from interrupt
1165 * context, use a bottom half instead.
1167 BUG_ON(in_interrupt());
1169 mutex_lock(&_event_lock);
1171 t->event_fn(t->event_context);
1172 mutex_unlock(&_event_lock);
1174 EXPORT_SYMBOL(dm_table_event);
1176 sector_t dm_table_get_size(struct dm_table *t)
1178 return t->num_targets ? (t->highs[t->num_targets - 1] + 1) : 0;
1180 EXPORT_SYMBOL(dm_table_get_size);
1182 struct dm_target *dm_table_get_target(struct dm_table *t, unsigned int index)
1184 if (index >= t->num_targets)
1187 return t->targets + index;
1191 * Search the btree for the correct target.
1193 * Caller should check returned pointer with dm_target_is_valid()
1194 * to trap I/O beyond end of device.
1196 struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector)
1198 unsigned int l, n = 0, k = 0;
1201 for (l = 0; l < t->depth; l++) {
1202 n = get_child(n, k);
1203 node = get_node(t, l, n);
1205 for (k = 0; k < KEYS_PER_NODE; k++)
1206 if (node[k] >= sector)
1210 return &t->targets[(KEYS_PER_NODE * n) + k];
1214 * Establish the new table's queue_limits and validate them.
1216 int dm_calculate_queue_limits(struct dm_table *table,
1217 struct queue_limits *limits)
1219 struct dm_target *uninitialized_var(ti);
1220 struct queue_limits ti_limits;
1223 blk_set_stacking_limits(limits);
1225 while (i < dm_table_get_num_targets(table)) {
1226 blk_set_stacking_limits(&ti_limits);
1228 ti = dm_table_get_target(table, i++);
1230 if (!ti->type->iterate_devices)
1231 goto combine_limits;
1234 * Combine queue limits of all the devices this target uses.
1236 ti->type->iterate_devices(ti, dm_set_device_limits,
1239 /* Set I/O hints portion of queue limits */
1240 if (ti->type->io_hints)
1241 ti->type->io_hints(ti, &ti_limits);
1244 * Check each device area is consistent with the target's
1245 * overall queue limits.
1247 if (ti->type->iterate_devices(ti, device_area_is_invalid,
1253 * Merge this target's queue limits into the overall limits
1256 if (blk_stack_limits(limits, &ti_limits, 0) < 0)
1257 DMWARN("%s: adding target device "
1258 "(start sect %llu len %llu) "
1259 "caused an alignment inconsistency",
1260 dm_device_name(table->md),
1261 (unsigned long long) ti->begin,
1262 (unsigned long long) ti->len);
1265 return validate_hardware_logical_block_alignment(table, limits);
1269 * Set the integrity profile for this device if all devices used have
1270 * matching profiles. We're quite deep in the resume path but still
1271 * don't know if all devices (particularly DM devices this device
1272 * may be stacked on) have matching profiles. Even if the profiles
1273 * don't match we have no way to fail (to resume) at this point.
1275 static void dm_table_set_integrity(struct dm_table *t)
1277 struct gendisk *template_disk = NULL;
1279 if (!blk_get_integrity(dm_disk(t->md)))
1282 template_disk = dm_table_get_integrity_disk(t, true);
1284 blk_integrity_register(dm_disk(t->md),
1285 blk_get_integrity(template_disk));
1286 else if (blk_integrity_is_initialized(dm_disk(t->md)))
1287 DMWARN("%s: device no longer has a valid integrity profile",
1288 dm_device_name(t->md));
1290 DMWARN("%s: unable to establish an integrity profile",
1291 dm_device_name(t->md));
1294 static int device_flush_capable(struct dm_target *ti, struct dm_dev *dev,
1295 sector_t start, sector_t len, void *data)
1297 unsigned flush = (*(unsigned *)data);
1298 struct request_queue *q = bdev_get_queue(dev->bdev);
1300 return q && (q->flush_flags & flush);
1303 static bool dm_table_supports_flush(struct dm_table *t, unsigned flush)
1305 struct dm_target *ti;
1309 * Require at least one underlying device to support flushes.
1310 * t->devices includes internal dm devices such as mirror logs
1311 * so we need to use iterate_devices here, which targets
1312 * supporting flushes must provide.
1314 while (i < dm_table_get_num_targets(t)) {
1315 ti = dm_table_get_target(t, i++);
1317 if (!ti->num_flush_requests)
1320 if (ti->type->iterate_devices &&
1321 ti->type->iterate_devices(ti, device_flush_capable, &flush))
1328 static bool dm_table_discard_zeroes_data(struct dm_table *t)
1330 struct dm_target *ti;
1333 /* Ensure that all targets supports discard_zeroes_data. */
1334 while (i < dm_table_get_num_targets(t)) {
1335 ti = dm_table_get_target(t, i++);
1337 if (ti->discard_zeroes_data_unsupported)
1344 static int device_is_nonrot(struct dm_target *ti, struct dm_dev *dev,
1345 sector_t start, sector_t len, void *data)
1347 struct request_queue *q = bdev_get_queue(dev->bdev);
1349 return q && blk_queue_nonrot(q);
1352 static bool dm_table_is_nonrot(struct dm_table *t)
1354 struct dm_target *ti;
1357 /* Ensure that all underlying device are non-rotational. */
1358 while (i < dm_table_get_num_targets(t)) {
1359 ti = dm_table_get_target(t, i++);
1361 if (!ti->type->iterate_devices ||
1362 !ti->type->iterate_devices(ti, device_is_nonrot, NULL))
1369 void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
1370 struct queue_limits *limits)
1375 * Copy table's limits to the DM device's request_queue
1377 q->limits = *limits;
1379 if (!dm_table_supports_discards(t))
1380 queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, q);
1382 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q);
1384 if (dm_table_supports_flush(t, REQ_FLUSH)) {
1386 if (dm_table_supports_flush(t, REQ_FUA))
1389 blk_queue_flush(q, flush);
1391 if (!dm_table_discard_zeroes_data(t))
1392 q->limits.discard_zeroes_data = 0;
1394 if (dm_table_is_nonrot(t))
1395 queue_flag_set_unlocked(QUEUE_FLAG_NONROT, q);
1397 queue_flag_clear_unlocked(QUEUE_FLAG_NONROT, q);
1399 dm_table_set_integrity(t);
1402 * QUEUE_FLAG_STACKABLE must be set after all queue settings are
1403 * visible to other CPUs because, once the flag is set, incoming bios
1404 * are processed by request-based dm, which refers to the queue
1406 * Until the flag set, bios are passed to bio-based dm and queued to
1407 * md->deferred where queue settings are not needed yet.
1408 * Those bios are passed to request-based dm at the resume time.
1411 if (dm_table_request_based(t))
1412 queue_flag_set_unlocked(QUEUE_FLAG_STACKABLE, q);
1415 unsigned int dm_table_get_num_targets(struct dm_table *t)
1417 return t->num_targets;
1420 struct list_head *dm_table_get_devices(struct dm_table *t)
1425 fmode_t dm_table_get_mode(struct dm_table *t)
1429 EXPORT_SYMBOL(dm_table_get_mode);
1431 static void suspend_targets(struct dm_table *t, unsigned postsuspend)
1433 int i = t->num_targets;
1434 struct dm_target *ti = t->targets;
1438 if (ti->type->postsuspend)
1439 ti->type->postsuspend(ti);
1440 } else if (ti->type->presuspend)
1441 ti->type->presuspend(ti);
1447 void dm_table_presuspend_targets(struct dm_table *t)
1452 suspend_targets(t, 0);
1455 void dm_table_postsuspend_targets(struct dm_table *t)
1460 suspend_targets(t, 1);
1463 int dm_table_resume_targets(struct dm_table *t)
1467 for (i = 0; i < t->num_targets; i++) {
1468 struct dm_target *ti = t->targets + i;
1470 if (!ti->type->preresume)
1473 r = ti->type->preresume(ti);
1478 for (i = 0; i < t->num_targets; i++) {
1479 struct dm_target *ti = t->targets + i;
1481 if (ti->type->resume)
1482 ti->type->resume(ti);
1488 void dm_table_add_target_callbacks(struct dm_table *t, struct dm_target_callbacks *cb)
1490 list_add(&cb->list, &t->target_callbacks);
1492 EXPORT_SYMBOL_GPL(dm_table_add_target_callbacks);
1494 int dm_table_any_congested(struct dm_table *t, int bdi_bits)
1496 struct dm_dev_internal *dd;
1497 struct list_head *devices = dm_table_get_devices(t);
1498 struct dm_target_callbacks *cb;
1501 list_for_each_entry(dd, devices, list) {
1502 struct request_queue *q = bdev_get_queue(dd->dm_dev.bdev);
1503 char b[BDEVNAME_SIZE];
1506 r |= bdi_congested(&q->backing_dev_info, bdi_bits);
1508 DMWARN_LIMIT("%s: any_congested: nonexistent device %s",
1509 dm_device_name(t->md),
1510 bdevname(dd->dm_dev.bdev, b));
1513 list_for_each_entry(cb, &t->target_callbacks, list)
1514 if (cb->congested_fn)
1515 r |= cb->congested_fn(cb, bdi_bits);
1520 int dm_table_any_busy_target(struct dm_table *t)
1523 struct dm_target *ti;
1525 for (i = 0; i < t->num_targets; i++) {
1526 ti = t->targets + i;
1527 if (ti->type->busy && ti->type->busy(ti))
1534 struct mapped_device *dm_table_get_md(struct dm_table *t)
1538 EXPORT_SYMBOL(dm_table_get_md);
1540 static int device_discard_capable(struct dm_target *ti, struct dm_dev *dev,
1541 sector_t start, sector_t len, void *data)
1543 struct request_queue *q = bdev_get_queue(dev->bdev);
1545 return q && blk_queue_discard(q);
1548 bool dm_table_supports_discards(struct dm_table *t)
1550 struct dm_target *ti;
1554 * Unless any target used by the table set discards_supported,
1555 * require at least one underlying device to support discards.
1556 * t->devices includes internal dm devices such as mirror logs
1557 * so we need to use iterate_devices here, which targets
1558 * supporting discard selectively must provide.
1560 while (i < dm_table_get_num_targets(t)) {
1561 ti = dm_table_get_target(t, i++);
1563 if (!ti->num_discard_requests)
1566 if (ti->discards_supported)
1569 if (ti->type->iterate_devices &&
1570 ti->type->iterate_devices(ti, device_discard_capable, NULL))