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 struct mapped_device *md;
35 unsigned int counts[MAX_DEPTH]; /* in nodes */
36 sector_t *index[MAX_DEPTH];
38 unsigned int num_targets;
39 unsigned int num_allocated;
41 struct dm_target *targets;
43 struct target_type *immutable_target_type;
44 unsigned integrity_supported:1;
48 * Indicates the rw permissions for the new logical
49 * device. This should be a combination of FMODE_READ
54 /* a list of devices used by this table */
55 struct list_head devices;
57 /* events get handed up using this callback */
58 void (*event_fn)(void *);
61 struct dm_md_mempools *mempools;
63 struct list_head target_callbacks;
67 * Similar to ceiling(log_size(n))
69 static unsigned int int_log(unsigned int n, unsigned int base)
74 n = dm_div_up(n, base);
82 * Calculate the index of the child node of the n'th node k'th key.
84 static inline unsigned int get_child(unsigned int n, unsigned int k)
86 return (n * CHILDREN_PER_NODE) + k;
90 * Return the n'th node of level l from table t.
92 static inline sector_t *get_node(struct dm_table *t,
93 unsigned int l, unsigned int n)
95 return t->index[l] + (n * KEYS_PER_NODE);
99 * Return the highest key that you could lookup from the n'th
100 * node on level l of the btree.
102 static sector_t high(struct dm_table *t, unsigned int l, unsigned int n)
104 for (; l < t->depth - 1; l++)
105 n = get_child(n, CHILDREN_PER_NODE - 1);
107 if (n >= t->counts[l])
108 return (sector_t) - 1;
110 return get_node(t, l, n)[KEYS_PER_NODE - 1];
114 * Fills in a level of the btree based on the highs of the level
117 static int setup_btree_index(unsigned int l, struct dm_table *t)
122 for (n = 0U; n < t->counts[l]; n++) {
123 node = get_node(t, l, n);
125 for (k = 0U; k < KEYS_PER_NODE; k++)
126 node[k] = high(t, l + 1, get_child(n, k));
132 void *dm_vcalloc(unsigned long nmemb, unsigned long elem_size)
138 * Check that we're not going to overflow.
140 if (nmemb > (ULONG_MAX / elem_size))
143 size = nmemb * elem_size;
144 addr = vzalloc(size);
148 EXPORT_SYMBOL(dm_vcalloc);
151 * highs, and targets are managed as dynamic arrays during a
154 static int alloc_targets(struct dm_table *t, unsigned int num)
157 struct dm_target *n_targets;
158 int n = t->num_targets;
161 * Allocate both the target array and offset array at once.
162 * Append an empty entry to catch sectors beyond the end of
165 n_highs = (sector_t *) dm_vcalloc(num + 1, sizeof(struct dm_target) +
170 n_targets = (struct dm_target *) (n_highs + num);
173 memcpy(n_highs, t->highs, sizeof(*n_highs) * n);
174 memcpy(n_targets, t->targets, sizeof(*n_targets) * n);
177 memset(n_highs + n, -1, sizeof(*n_highs) * (num - n));
180 t->num_allocated = num;
182 t->targets = n_targets;
187 int dm_table_create(struct dm_table **result, fmode_t mode,
188 unsigned num_targets, struct mapped_device *md)
190 struct dm_table *t = kzalloc(sizeof(*t), GFP_KERNEL);
195 INIT_LIST_HEAD(&t->devices);
196 INIT_LIST_HEAD(&t->target_callbacks);
199 num_targets = KEYS_PER_NODE;
201 num_targets = dm_round_up(num_targets, KEYS_PER_NODE);
208 if (alloc_targets(t, num_targets)) {
219 static void free_devices(struct list_head *devices)
221 struct list_head *tmp, *next;
223 list_for_each_safe(tmp, next, devices) {
224 struct dm_dev_internal *dd =
225 list_entry(tmp, struct dm_dev_internal, list);
226 DMWARN("dm_table_destroy: dm_put_device call missing for %s",
232 void dm_table_destroy(struct dm_table *t)
239 /* free the indexes */
241 vfree(t->index[t->depth - 2]);
243 /* free the targets */
244 for (i = 0; i < t->num_targets; i++) {
245 struct dm_target *tgt = t->targets + i;
250 dm_put_target_type(tgt->type);
255 /* free the device list */
256 free_devices(&t->devices);
258 dm_free_md_mempools(t->mempools);
264 * Checks to see if we need to extend highs or targets.
266 static inline int check_space(struct dm_table *t)
268 if (t->num_targets >= t->num_allocated)
269 return alloc_targets(t, t->num_allocated * 2);
275 * See if we've already got a device in the list.
277 static struct dm_dev_internal *find_device(struct list_head *l, dev_t dev)
279 struct dm_dev_internal *dd;
281 list_for_each_entry (dd, l, list)
282 if (dd->dm_dev.bdev->bd_dev == dev)
289 * Open a device so we can use it as a map destination.
291 static int open_dev(struct dm_dev_internal *d, dev_t dev,
292 struct mapped_device *md)
294 static char *_claim_ptr = "I belong to device-mapper";
295 struct block_device *bdev;
299 BUG_ON(d->dm_dev.bdev);
301 bdev = blkdev_get_by_dev(dev, d->dm_dev.mode | FMODE_EXCL, _claim_ptr);
303 return PTR_ERR(bdev);
305 r = bd_link_disk_holder(bdev, dm_disk(md));
307 blkdev_put(bdev, d->dm_dev.mode | FMODE_EXCL);
311 d->dm_dev.bdev = bdev;
316 * Close a device that we've been using.
318 static void close_dev(struct dm_dev_internal *d, struct mapped_device *md)
323 bd_unlink_disk_holder(d->dm_dev.bdev, dm_disk(md));
324 blkdev_put(d->dm_dev.bdev, d->dm_dev.mode | FMODE_EXCL);
325 d->dm_dev.bdev = NULL;
329 * If possible, this checks an area of a destination device is invalid.
331 static int device_area_is_invalid(struct dm_target *ti, struct dm_dev *dev,
332 sector_t start, sector_t len, void *data)
334 struct request_queue *q;
335 struct queue_limits *limits = data;
336 struct block_device *bdev = dev->bdev;
338 i_size_read(bdev->bd_inode) >> SECTOR_SHIFT;
339 unsigned short logical_block_size_sectors =
340 limits->logical_block_size >> SECTOR_SHIFT;
341 char b[BDEVNAME_SIZE];
344 * Some devices exist without request functions,
345 * such as loop devices not yet bound to backing files.
346 * Forbid the use of such devices.
348 q = bdev_get_queue(bdev);
349 if (!q || !q->make_request_fn) {
350 DMWARN("%s: %s is not yet initialised: "
351 "start=%llu, len=%llu, dev_size=%llu",
352 dm_device_name(ti->table->md), bdevname(bdev, b),
353 (unsigned long long)start,
354 (unsigned long long)len,
355 (unsigned long long)dev_size);
362 if ((start >= dev_size) || (start + len > dev_size)) {
363 DMWARN("%s: %s too small for target: "
364 "start=%llu, len=%llu, dev_size=%llu",
365 dm_device_name(ti->table->md), bdevname(bdev, b),
366 (unsigned long long)start,
367 (unsigned long long)len,
368 (unsigned long long)dev_size);
372 if (logical_block_size_sectors <= 1)
375 if (start & (logical_block_size_sectors - 1)) {
376 DMWARN("%s: start=%llu not aligned to h/w "
377 "logical block size %u of %s",
378 dm_device_name(ti->table->md),
379 (unsigned long long)start,
380 limits->logical_block_size, bdevname(bdev, b));
384 if (len & (logical_block_size_sectors - 1)) {
385 DMWARN("%s: len=%llu not aligned to h/w "
386 "logical block size %u of %s",
387 dm_device_name(ti->table->md),
388 (unsigned long long)len,
389 limits->logical_block_size, bdevname(bdev, b));
397 * This upgrades the mode on an already open dm_dev, being
398 * careful to leave things as they were if we fail to reopen the
399 * device and not to touch the existing bdev field in case
400 * it is accessed concurrently inside dm_table_any_congested().
402 static int upgrade_mode(struct dm_dev_internal *dd, fmode_t new_mode,
403 struct mapped_device *md)
406 struct dm_dev_internal dd_new, dd_old;
408 dd_new = dd_old = *dd;
410 dd_new.dm_dev.mode |= new_mode;
411 dd_new.dm_dev.bdev = NULL;
413 r = open_dev(&dd_new, dd->dm_dev.bdev->bd_dev, md);
417 dd->dm_dev.mode |= new_mode;
418 close_dev(&dd_old, md);
424 * Add a device to the list, or just increment the usage count if
425 * it's already present.
427 int dm_get_device(struct dm_target *ti, const char *path, fmode_t mode,
428 struct dm_dev **result)
431 dev_t uninitialized_var(dev);
432 struct dm_dev_internal *dd;
433 unsigned int major, minor;
434 struct dm_table *t = ti->table;
439 if (sscanf(path, "%u:%u%c", &major, &minor, &dummy) == 2) {
440 /* Extract the major/minor numbers */
441 dev = MKDEV(major, minor);
442 if (MAJOR(dev) != major || MINOR(dev) != minor)
445 /* convert the path to a device */
446 struct block_device *bdev = lookup_bdev(path);
449 return PTR_ERR(bdev);
454 dd = find_device(&t->devices, dev);
456 dd = kmalloc(sizeof(*dd), GFP_KERNEL);
460 dd->dm_dev.mode = mode;
461 dd->dm_dev.bdev = NULL;
463 if ((r = open_dev(dd, dev, t->md))) {
468 format_dev_t(dd->dm_dev.name, dev);
470 atomic_set(&dd->count, 0);
471 list_add(&dd->list, &t->devices);
473 } else if (dd->dm_dev.mode != (mode | dd->dm_dev.mode)) {
474 r = upgrade_mode(dd, mode, t->md);
478 atomic_inc(&dd->count);
480 *result = &dd->dm_dev;
483 EXPORT_SYMBOL(dm_get_device);
485 int dm_set_device_limits(struct dm_target *ti, struct dm_dev *dev,
486 sector_t start, sector_t len, void *data)
488 struct queue_limits *limits = data;
489 struct block_device *bdev = dev->bdev;
490 struct request_queue *q = bdev_get_queue(bdev);
491 char b[BDEVNAME_SIZE];
494 DMWARN("%s: Cannot set limits for nonexistent device %s",
495 dm_device_name(ti->table->md), bdevname(bdev, b));
499 if (bdev_stack_limits(limits, bdev, start) < 0)
500 DMWARN("%s: adding target device %s caused an alignment inconsistency: "
501 "physical_block_size=%u, logical_block_size=%u, "
502 "alignment_offset=%u, start=%llu",
503 dm_device_name(ti->table->md), bdevname(bdev, b),
504 q->limits.physical_block_size,
505 q->limits.logical_block_size,
506 q->limits.alignment_offset,
507 (unsigned long long) start << SECTOR_SHIFT);
510 * Check if merge fn is supported.
511 * If not we'll force DM to use PAGE_SIZE or
512 * smaller I/O, just to be safe.
514 if (dm_queue_merge_is_compulsory(q) && !ti->type->merge)
515 blk_limits_max_hw_sectors(limits,
516 (unsigned int) (PAGE_SIZE >> 9));
519 EXPORT_SYMBOL_GPL(dm_set_device_limits);
522 * Decrement a device's use count and remove it if necessary.
524 void dm_put_device(struct dm_target *ti, struct dm_dev *d)
526 struct dm_dev_internal *dd = container_of(d, struct dm_dev_internal,
529 if (atomic_dec_and_test(&dd->count)) {
530 close_dev(dd, ti->table->md);
535 EXPORT_SYMBOL(dm_put_device);
538 * Checks to see if the target joins onto the end of the table.
540 static int adjoin(struct dm_table *table, struct dm_target *ti)
542 struct dm_target *prev;
544 if (!table->num_targets)
547 prev = &table->targets[table->num_targets - 1];
548 return (ti->begin == (prev->begin + prev->len));
552 * Used to dynamically allocate the arg array.
554 * We do first allocation with GFP_NOIO because dm-mpath and dm-thin must
555 * process messages even if some device is suspended. These messages have a
556 * small fixed number of arguments.
558 * On the other hand, dm-switch needs to process bulk data using messages and
559 * excessive use of GFP_NOIO could cause trouble.
561 static char **realloc_argv(unsigned *array_size, char **old_argv)
568 new_size = *array_size * 2;
574 argv = kmalloc(new_size * sizeof(*argv), gfp);
576 memcpy(argv, old_argv, *array_size * sizeof(*argv));
577 *array_size = new_size;
585 * Destructively splits up the argument list to pass to ctr.
587 int dm_split_args(int *argc, char ***argvp, char *input)
589 char *start, *end = input, *out, **argv = NULL;
590 unsigned array_size = 0;
599 argv = realloc_argv(&array_size, argv);
604 /* Skip whitespace */
605 start = skip_spaces(end);
608 break; /* success, we hit the end */
610 /* 'out' is used to remove any back-quotes */
613 /* Everything apart from '\0' can be quoted */
614 if (*end == '\\' && *(end + 1)) {
621 break; /* end of token */
626 /* have we already filled the array ? */
627 if ((*argc + 1) > array_size) {
628 argv = realloc_argv(&array_size, argv);
633 /* we know this is whitespace */
637 /* terminate the string and put it in the array */
648 * Impose necessary and sufficient conditions on a devices's table such
649 * that any incoming bio which respects its logical_block_size can be
650 * processed successfully. If it falls across the boundary between
651 * two or more targets, the size of each piece it gets split into must
652 * be compatible with the logical_block_size of the target processing it.
654 static int validate_hardware_logical_block_alignment(struct dm_table *table,
655 struct queue_limits *limits)
658 * This function uses arithmetic modulo the logical_block_size
659 * (in units of 512-byte sectors).
661 unsigned short device_logical_block_size_sects =
662 limits->logical_block_size >> SECTOR_SHIFT;
665 * Offset of the start of the next table entry, mod logical_block_size.
667 unsigned short next_target_start = 0;
670 * Given an aligned bio that extends beyond the end of a
671 * target, how many sectors must the next target handle?
673 unsigned short remaining = 0;
675 struct dm_target *uninitialized_var(ti);
676 struct queue_limits ti_limits;
680 * Check each entry in the table in turn.
682 while (i < dm_table_get_num_targets(table)) {
683 ti = dm_table_get_target(table, i++);
685 blk_set_stacking_limits(&ti_limits);
687 /* combine all target devices' limits */
688 if (ti->type->iterate_devices)
689 ti->type->iterate_devices(ti, dm_set_device_limits,
693 * If the remaining sectors fall entirely within this
694 * table entry are they compatible with its logical_block_size?
696 if (remaining < ti->len &&
697 remaining & ((ti_limits.logical_block_size >>
702 (unsigned short) ((next_target_start + ti->len) &
703 (device_logical_block_size_sects - 1));
704 remaining = next_target_start ?
705 device_logical_block_size_sects - next_target_start : 0;
709 DMWARN("%s: table line %u (start sect %llu len %llu) "
710 "not aligned to h/w logical block size %u",
711 dm_device_name(table->md), i,
712 (unsigned long long) ti->begin,
713 (unsigned long long) ti->len,
714 limits->logical_block_size);
721 int dm_table_add_target(struct dm_table *t, const char *type,
722 sector_t start, sector_t len, char *params)
724 int r = -EINVAL, argc;
726 struct dm_target *tgt;
729 DMERR("%s: target type %s must appear alone in table",
730 dm_device_name(t->md), t->targets->type->name);
734 if ((r = check_space(t)))
737 tgt = t->targets + t->num_targets;
738 memset(tgt, 0, sizeof(*tgt));
741 DMERR("%s: zero-length target", dm_device_name(t->md));
745 tgt->type = dm_get_target_type(type);
747 DMERR("%s: %s: unknown target type", dm_device_name(t->md),
752 if (dm_target_needs_singleton(tgt->type)) {
753 if (t->num_targets) {
754 DMERR("%s: target type %s must appear alone in table",
755 dm_device_name(t->md), type);
761 if (dm_target_always_writeable(tgt->type) && !(t->mode & FMODE_WRITE)) {
762 DMERR("%s: target type %s may not be included in read-only tables",
763 dm_device_name(t->md), type);
767 if (t->immutable_target_type) {
768 if (t->immutable_target_type != tgt->type) {
769 DMERR("%s: immutable target type %s cannot be mixed with other target types",
770 dm_device_name(t->md), t->immutable_target_type->name);
773 } else if (dm_target_is_immutable(tgt->type)) {
774 if (t->num_targets) {
775 DMERR("%s: immutable target type %s cannot be mixed with other target types",
776 dm_device_name(t->md), tgt->type->name);
779 t->immutable_target_type = tgt->type;
785 tgt->error = "Unknown error";
788 * Does this target adjoin the previous one ?
790 if (!adjoin(t, tgt)) {
791 tgt->error = "Gap in table";
796 r = dm_split_args(&argc, &argv, params);
798 tgt->error = "couldn't split parameters (insufficient memory)";
802 r = tgt->type->ctr(tgt, argc, argv);
807 t->highs[t->num_targets++] = tgt->begin + tgt->len - 1;
809 if (!tgt->num_discard_bios && tgt->discards_supported)
810 DMWARN("%s: %s: ignoring discards_supported because num_discard_bios is zero.",
811 dm_device_name(t->md), type);
816 DMERR("%s: %s: %s", dm_device_name(t->md), type, tgt->error);
817 dm_put_target_type(tgt->type);
822 * Target argument parsing helpers.
824 static int validate_next_arg(struct dm_arg *arg, struct dm_arg_set *arg_set,
825 unsigned *value, char **error, unsigned grouped)
827 const char *arg_str = dm_shift_arg(arg_set);
831 (sscanf(arg_str, "%u%c", value, &dummy) != 1) ||
832 (*value < arg->min) ||
833 (*value > arg->max) ||
834 (grouped && arg_set->argc < *value)) {
842 int dm_read_arg(struct dm_arg *arg, struct dm_arg_set *arg_set,
843 unsigned *value, char **error)
845 return validate_next_arg(arg, arg_set, value, error, 0);
847 EXPORT_SYMBOL(dm_read_arg);
849 int dm_read_arg_group(struct dm_arg *arg, struct dm_arg_set *arg_set,
850 unsigned *value, char **error)
852 return validate_next_arg(arg, arg_set, value, error, 1);
854 EXPORT_SYMBOL(dm_read_arg_group);
856 const char *dm_shift_arg(struct dm_arg_set *as)
869 EXPORT_SYMBOL(dm_shift_arg);
871 void dm_consume_args(struct dm_arg_set *as, unsigned num_args)
873 BUG_ON(as->argc < num_args);
874 as->argc -= num_args;
875 as->argv += num_args;
877 EXPORT_SYMBOL(dm_consume_args);
879 static int dm_table_set_type(struct dm_table *t)
882 unsigned bio_based = 0, request_based = 0, hybrid = 0;
883 struct dm_target *tgt;
884 struct dm_dev_internal *dd;
885 struct list_head *devices;
886 unsigned live_md_type;
888 for (i = 0; i < t->num_targets; i++) {
889 tgt = t->targets + i;
890 if (dm_target_hybrid(tgt))
892 else if (dm_target_request_based(tgt))
897 if (bio_based && request_based) {
898 DMWARN("Inconsistent table: different target types"
899 " can't be mixed up");
904 if (hybrid && !bio_based && !request_based) {
906 * The targets can work either way.
907 * Determine the type from the live device.
908 * Default to bio-based if device is new.
910 live_md_type = dm_get_md_type(t->md);
911 if (live_md_type == DM_TYPE_REQUEST_BASED)
918 /* We must use this table as bio-based */
919 t->type = DM_TYPE_BIO_BASED;
923 BUG_ON(!request_based); /* No targets in this table */
925 /* Non-request-stackable devices can't be used for request-based dm */
926 devices = dm_table_get_devices(t);
927 list_for_each_entry(dd, devices, list) {
928 if (!blk_queue_stackable(bdev_get_queue(dd->dm_dev.bdev))) {
929 DMWARN("table load rejected: including"
930 " non-request-stackable devices");
936 * Request-based dm supports only tables that have a single target now.
937 * To support multiple targets, request splitting support is needed,
938 * and that needs lots of changes in the block-layer.
939 * (e.g. request completion process for partial completion.)
941 if (t->num_targets > 1) {
942 DMWARN("Request-based dm doesn't support multiple targets yet");
946 t->type = DM_TYPE_REQUEST_BASED;
951 unsigned dm_table_get_type(struct dm_table *t)
956 struct target_type *dm_table_get_immutable_target_type(struct dm_table *t)
958 return t->immutable_target_type;
961 bool dm_table_request_based(struct dm_table *t)
963 return dm_table_get_type(t) == DM_TYPE_REQUEST_BASED;
966 int dm_table_alloc_md_mempools(struct dm_table *t)
968 unsigned type = dm_table_get_type(t);
969 unsigned per_bio_data_size = 0;
970 struct dm_target *tgt;
973 if (unlikely(type == DM_TYPE_NONE)) {
974 DMWARN("no table type is set, can't allocate mempools");
978 if (type == DM_TYPE_BIO_BASED)
979 for (i = 0; i < t->num_targets; i++) {
980 tgt = t->targets + i;
981 per_bio_data_size = max(per_bio_data_size, tgt->per_bio_data_size);
984 t->mempools = dm_alloc_md_mempools(type, t->integrity_supported, per_bio_data_size);
991 void dm_table_free_md_mempools(struct dm_table *t)
993 dm_free_md_mempools(t->mempools);
997 struct dm_md_mempools *dm_table_get_md_mempools(struct dm_table *t)
1002 static int setup_indexes(struct dm_table *t)
1005 unsigned int total = 0;
1008 /* allocate the space for *all* the indexes */
1009 for (i = t->depth - 2; i >= 0; i--) {
1010 t->counts[i] = dm_div_up(t->counts[i + 1], CHILDREN_PER_NODE);
1011 total += t->counts[i];
1014 indexes = (sector_t *) dm_vcalloc(total, (unsigned long) NODE_SIZE);
1018 /* set up internal nodes, bottom-up */
1019 for (i = t->depth - 2; i >= 0; i--) {
1020 t->index[i] = indexes;
1021 indexes += (KEYS_PER_NODE * t->counts[i]);
1022 setup_btree_index(i, t);
1029 * Builds the btree to index the map.
1031 static int dm_table_build_index(struct dm_table *t)
1034 unsigned int leaf_nodes;
1036 /* how many indexes will the btree have ? */
1037 leaf_nodes = dm_div_up(t->num_targets, KEYS_PER_NODE);
1038 t->depth = 1 + int_log(leaf_nodes, CHILDREN_PER_NODE);
1040 /* leaf layer has already been set up */
1041 t->counts[t->depth - 1] = leaf_nodes;
1042 t->index[t->depth - 1] = t->highs;
1045 r = setup_indexes(t);
1051 * Get a disk whose integrity profile reflects the table's profile.
1052 * If %match_all is true, all devices' profiles must match.
1053 * If %match_all is false, all devices must at least have an
1054 * allocated integrity profile; but uninitialized is ok.
1055 * Returns NULL if integrity support was inconsistent or unavailable.
1057 static struct gendisk * dm_table_get_integrity_disk(struct dm_table *t,
1060 struct list_head *devices = dm_table_get_devices(t);
1061 struct dm_dev_internal *dd = NULL;
1062 struct gendisk *prev_disk = NULL, *template_disk = NULL;
1064 list_for_each_entry(dd, devices, list) {
1065 template_disk = dd->dm_dev.bdev->bd_disk;
1066 if (!blk_get_integrity(template_disk))
1068 if (!match_all && !blk_integrity_is_initialized(template_disk))
1069 continue; /* skip uninitialized profiles */
1070 else if (prev_disk &&
1071 blk_integrity_compare(prev_disk, template_disk) < 0)
1073 prev_disk = template_disk;
1076 return template_disk;
1080 DMWARN("%s: integrity not set: %s and %s profile mismatch",
1081 dm_device_name(t->md),
1082 prev_disk->disk_name,
1083 template_disk->disk_name);
1088 * Register the mapped device for blk_integrity support if
1089 * the underlying devices have an integrity profile. But all devices
1090 * may not have matching profiles (checking all devices isn't reliable
1091 * during table load because this table may use other DM device(s) which
1092 * must be resumed before they will have an initialized integity profile).
1093 * Stacked DM devices force a 2 stage integrity profile validation:
1094 * 1 - during load, validate all initialized integrity profiles match
1095 * 2 - during resume, validate all integrity profiles match
1097 static int dm_table_prealloc_integrity(struct dm_table *t, struct mapped_device *md)
1099 struct gendisk *template_disk = NULL;
1101 template_disk = dm_table_get_integrity_disk(t, false);
1105 if (!blk_integrity_is_initialized(dm_disk(md))) {
1106 t->integrity_supported = 1;
1107 return blk_integrity_register(dm_disk(md), NULL);
1111 * If DM device already has an initalized integrity
1112 * profile the new profile should not conflict.
1114 if (blk_integrity_is_initialized(template_disk) &&
1115 blk_integrity_compare(dm_disk(md), template_disk) < 0) {
1116 DMWARN("%s: conflict with existing integrity profile: "
1117 "%s profile mismatch",
1118 dm_device_name(t->md),
1119 template_disk->disk_name);
1123 /* Preserve existing initialized integrity profile */
1124 t->integrity_supported = 1;
1129 * Prepares the table for use by building the indices,
1130 * setting the type, and allocating mempools.
1132 int dm_table_complete(struct dm_table *t)
1136 r = dm_table_set_type(t);
1138 DMERR("unable to set table type");
1142 r = dm_table_build_index(t);
1144 DMERR("unable to build btrees");
1148 r = dm_table_prealloc_integrity(t, t->md);
1150 DMERR("could not register integrity profile.");
1154 r = dm_table_alloc_md_mempools(t);
1156 DMERR("unable to allocate mempools");
1161 static DEFINE_MUTEX(_event_lock);
1162 void dm_table_event_callback(struct dm_table *t,
1163 void (*fn)(void *), void *context)
1165 mutex_lock(&_event_lock);
1167 t->event_context = context;
1168 mutex_unlock(&_event_lock);
1171 void dm_table_event(struct dm_table *t)
1174 * You can no longer call dm_table_event() from interrupt
1175 * context, use a bottom half instead.
1177 BUG_ON(in_interrupt());
1179 mutex_lock(&_event_lock);
1181 t->event_fn(t->event_context);
1182 mutex_unlock(&_event_lock);
1184 EXPORT_SYMBOL(dm_table_event);
1186 sector_t dm_table_get_size(struct dm_table *t)
1188 return t->num_targets ? (t->highs[t->num_targets - 1] + 1) : 0;
1190 EXPORT_SYMBOL(dm_table_get_size);
1192 struct dm_target *dm_table_get_target(struct dm_table *t, unsigned int index)
1194 if (index >= t->num_targets)
1197 return t->targets + index;
1201 * Search the btree for the correct target.
1203 * Caller should check returned pointer with dm_target_is_valid()
1204 * to trap I/O beyond end of device.
1206 struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector)
1208 unsigned int l, n = 0, k = 0;
1211 for (l = 0; l < t->depth; l++) {
1212 n = get_child(n, k);
1213 node = get_node(t, l, n);
1215 for (k = 0; k < KEYS_PER_NODE; k++)
1216 if (node[k] >= sector)
1220 return &t->targets[(KEYS_PER_NODE * n) + k];
1223 static int count_device(struct dm_target *ti, struct dm_dev *dev,
1224 sector_t start, sector_t len, void *data)
1226 unsigned *num_devices = data;
1234 * Check whether a table has no data devices attached using each
1235 * target's iterate_devices method.
1236 * Returns false if the result is unknown because a target doesn't
1237 * support iterate_devices.
1239 bool dm_table_has_no_data_devices(struct dm_table *table)
1241 struct dm_target *uninitialized_var(ti);
1242 unsigned i = 0, num_devices = 0;
1244 while (i < dm_table_get_num_targets(table)) {
1245 ti = dm_table_get_target(table, i++);
1247 if (!ti->type->iterate_devices)
1250 ti->type->iterate_devices(ti, count_device, &num_devices);
1259 * Establish the new table's queue_limits and validate them.
1261 int dm_calculate_queue_limits(struct dm_table *table,
1262 struct queue_limits *limits)
1264 struct dm_target *uninitialized_var(ti);
1265 struct queue_limits ti_limits;
1268 blk_set_stacking_limits(limits);
1270 while (i < dm_table_get_num_targets(table)) {
1271 blk_set_stacking_limits(&ti_limits);
1273 ti = dm_table_get_target(table, i++);
1275 if (!ti->type->iterate_devices)
1276 goto combine_limits;
1279 * Combine queue limits of all the devices this target uses.
1281 ti->type->iterate_devices(ti, dm_set_device_limits,
1284 /* Set I/O hints portion of queue limits */
1285 if (ti->type->io_hints)
1286 ti->type->io_hints(ti, &ti_limits);
1289 * Check each device area is consistent with the target's
1290 * overall queue limits.
1292 if (ti->type->iterate_devices(ti, device_area_is_invalid,
1298 * Merge this target's queue limits into the overall limits
1301 if (blk_stack_limits(limits, &ti_limits, 0) < 0)
1302 DMWARN("%s: adding target device "
1303 "(start sect %llu len %llu) "
1304 "caused an alignment inconsistency",
1305 dm_device_name(table->md),
1306 (unsigned long long) ti->begin,
1307 (unsigned long long) ti->len);
1310 return validate_hardware_logical_block_alignment(table, limits);
1314 * Set the integrity profile for this device if all devices used have
1315 * matching profiles. We're quite deep in the resume path but still
1316 * don't know if all devices (particularly DM devices this device
1317 * may be stacked on) have matching profiles. Even if the profiles
1318 * don't match we have no way to fail (to resume) at this point.
1320 static void dm_table_set_integrity(struct dm_table *t)
1322 struct gendisk *template_disk = NULL;
1324 if (!blk_get_integrity(dm_disk(t->md)))
1327 template_disk = dm_table_get_integrity_disk(t, true);
1329 blk_integrity_register(dm_disk(t->md),
1330 blk_get_integrity(template_disk));
1331 else if (blk_integrity_is_initialized(dm_disk(t->md)))
1332 DMWARN("%s: device no longer has a valid integrity profile",
1333 dm_device_name(t->md));
1335 DMWARN("%s: unable to establish an integrity profile",
1336 dm_device_name(t->md));
1339 static int device_flush_capable(struct dm_target *ti, struct dm_dev *dev,
1340 sector_t start, sector_t len, void *data)
1342 unsigned flush = (*(unsigned *)data);
1343 struct request_queue *q = bdev_get_queue(dev->bdev);
1345 return q && (q->flush_flags & flush);
1348 static bool dm_table_supports_flush(struct dm_table *t, unsigned flush)
1350 struct dm_target *ti;
1354 * Require at least one underlying device to support flushes.
1355 * t->devices includes internal dm devices such as mirror logs
1356 * so we need to use iterate_devices here, which targets
1357 * supporting flushes must provide.
1359 while (i < dm_table_get_num_targets(t)) {
1360 ti = dm_table_get_target(t, i++);
1362 if (!ti->num_flush_bios)
1365 if (ti->flush_supported)
1368 if (ti->type->iterate_devices &&
1369 ti->type->iterate_devices(ti, device_flush_capable, &flush))
1376 static bool dm_table_discard_zeroes_data(struct dm_table *t)
1378 struct dm_target *ti;
1381 /* Ensure that all targets supports discard_zeroes_data. */
1382 while (i < dm_table_get_num_targets(t)) {
1383 ti = dm_table_get_target(t, i++);
1385 if (ti->discard_zeroes_data_unsupported)
1392 static int device_is_nonrot(struct dm_target *ti, struct dm_dev *dev,
1393 sector_t start, sector_t len, void *data)
1395 struct request_queue *q = bdev_get_queue(dev->bdev);
1397 return q && blk_queue_nonrot(q);
1400 static int device_is_not_random(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 && !blk_queue_add_random(q);
1408 static bool dm_table_all_devices_attribute(struct dm_table *t,
1409 iterate_devices_callout_fn func)
1411 struct dm_target *ti;
1414 while (i < dm_table_get_num_targets(t)) {
1415 ti = dm_table_get_target(t, i++);
1417 if (!ti->type->iterate_devices ||
1418 !ti->type->iterate_devices(ti, func, NULL))
1425 static int device_not_write_same_capable(struct dm_target *ti, struct dm_dev *dev,
1426 sector_t start, sector_t len, void *data)
1428 struct request_queue *q = bdev_get_queue(dev->bdev);
1430 return q && !q->limits.max_write_same_sectors;
1433 static bool dm_table_supports_write_same(struct dm_table *t)
1435 struct dm_target *ti;
1438 while (i < dm_table_get_num_targets(t)) {
1439 ti = dm_table_get_target(t, i++);
1441 if (!ti->num_write_same_bios)
1444 if (!ti->type->iterate_devices ||
1445 ti->type->iterate_devices(ti, device_not_write_same_capable, NULL))
1452 void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
1453 struct queue_limits *limits)
1458 * Copy table's limits to the DM device's request_queue
1460 q->limits = *limits;
1462 if (!dm_table_supports_discards(t))
1463 queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, q);
1465 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q);
1467 if (dm_table_supports_flush(t, REQ_FLUSH)) {
1469 if (dm_table_supports_flush(t, REQ_FUA))
1472 blk_queue_flush(q, flush);
1474 if (!dm_table_discard_zeroes_data(t))
1475 q->limits.discard_zeroes_data = 0;
1477 /* Ensure that all underlying devices are non-rotational. */
1478 if (dm_table_all_devices_attribute(t, device_is_nonrot))
1479 queue_flag_set_unlocked(QUEUE_FLAG_NONROT, q);
1481 queue_flag_clear_unlocked(QUEUE_FLAG_NONROT, q);
1483 if (!dm_table_supports_write_same(t))
1484 q->limits.max_write_same_sectors = 0;
1486 dm_table_set_integrity(t);
1489 * Determine whether or not this queue's I/O timings contribute
1490 * to the entropy pool, Only request-based targets use this.
1491 * Clear QUEUE_FLAG_ADD_RANDOM if any underlying device does not
1494 if (blk_queue_add_random(q) && dm_table_all_devices_attribute(t, device_is_not_random))
1495 queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, q);
1498 * QUEUE_FLAG_STACKABLE must be set after all queue settings are
1499 * visible to other CPUs because, once the flag is set, incoming bios
1500 * are processed by request-based dm, which refers to the queue
1502 * Until the flag set, bios are passed to bio-based dm and queued to
1503 * md->deferred where queue settings are not needed yet.
1504 * Those bios are passed to request-based dm at the resume time.
1507 if (dm_table_request_based(t))
1508 queue_flag_set_unlocked(QUEUE_FLAG_STACKABLE, q);
1511 unsigned int dm_table_get_num_targets(struct dm_table *t)
1513 return t->num_targets;
1516 struct list_head *dm_table_get_devices(struct dm_table *t)
1521 fmode_t dm_table_get_mode(struct dm_table *t)
1525 EXPORT_SYMBOL(dm_table_get_mode);
1527 static void suspend_targets(struct dm_table *t, unsigned postsuspend)
1529 int i = t->num_targets;
1530 struct dm_target *ti = t->targets;
1534 if (ti->type->postsuspend)
1535 ti->type->postsuspend(ti);
1536 } else if (ti->type->presuspend)
1537 ti->type->presuspend(ti);
1543 void dm_table_presuspend_targets(struct dm_table *t)
1548 suspend_targets(t, 0);
1551 void dm_table_postsuspend_targets(struct dm_table *t)
1556 suspend_targets(t, 1);
1559 int dm_table_resume_targets(struct dm_table *t)
1563 for (i = 0; i < t->num_targets; i++) {
1564 struct dm_target *ti = t->targets + i;
1566 if (!ti->type->preresume)
1569 r = ti->type->preresume(ti);
1571 DMERR("%s: %s: preresume failed, error = %d",
1572 dm_device_name(t->md), ti->type->name, r);
1577 for (i = 0; i < t->num_targets; i++) {
1578 struct dm_target *ti = t->targets + i;
1580 if (ti->type->resume)
1581 ti->type->resume(ti);
1587 void dm_table_add_target_callbacks(struct dm_table *t, struct dm_target_callbacks *cb)
1589 list_add(&cb->list, &t->target_callbacks);
1591 EXPORT_SYMBOL_GPL(dm_table_add_target_callbacks);
1593 int dm_table_any_congested(struct dm_table *t, int bdi_bits)
1595 struct dm_dev_internal *dd;
1596 struct list_head *devices = dm_table_get_devices(t);
1597 struct dm_target_callbacks *cb;
1600 list_for_each_entry(dd, devices, list) {
1601 struct request_queue *q = bdev_get_queue(dd->dm_dev.bdev);
1602 char b[BDEVNAME_SIZE];
1605 r |= bdi_congested(&q->backing_dev_info, bdi_bits);
1607 DMWARN_LIMIT("%s: any_congested: nonexistent device %s",
1608 dm_device_name(t->md),
1609 bdevname(dd->dm_dev.bdev, b));
1612 list_for_each_entry(cb, &t->target_callbacks, list)
1613 if (cb->congested_fn)
1614 r |= cb->congested_fn(cb, bdi_bits);
1619 int dm_table_any_busy_target(struct dm_table *t)
1622 struct dm_target *ti;
1624 for (i = 0; i < t->num_targets; i++) {
1625 ti = t->targets + i;
1626 if (ti->type->busy && ti->type->busy(ti))
1633 struct mapped_device *dm_table_get_md(struct dm_table *t)
1637 EXPORT_SYMBOL(dm_table_get_md);
1639 static int device_discard_capable(struct dm_target *ti, struct dm_dev *dev,
1640 sector_t start, sector_t len, void *data)
1642 struct request_queue *q = bdev_get_queue(dev->bdev);
1644 return q && blk_queue_discard(q);
1647 bool dm_table_supports_discards(struct dm_table *t)
1649 struct dm_target *ti;
1653 * Unless any target used by the table set discards_supported,
1654 * require at least one underlying device to support discards.
1655 * t->devices includes internal dm devices such as mirror logs
1656 * so we need to use iterate_devices here, which targets
1657 * supporting discard selectively must provide.
1659 while (i < dm_table_get_num_targets(t)) {
1660 ti = dm_table_get_target(t, i++);
1662 if (!ti->num_discard_bios)
1665 if (ti->discards_supported)
1668 if (ti->type->iterate_devices &&
1669 ti->type->iterate_devices(ti, device_discard_capable, NULL))