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;
160 * Allocate both the target array and offset array at once.
161 * Append an empty entry to catch sectors beyond the end of
164 n_highs = (sector_t *) dm_vcalloc(num + 1, sizeof(struct dm_target) +
169 n_targets = (struct dm_target *) (n_highs + num);
171 memset(n_highs, -1, sizeof(*n_highs) * num);
174 t->num_allocated = num;
176 t->targets = n_targets;
181 int dm_table_create(struct dm_table **result, fmode_t mode,
182 unsigned num_targets, struct mapped_device *md)
184 struct dm_table *t = kzalloc(sizeof(*t), GFP_KERNEL);
189 INIT_LIST_HEAD(&t->devices);
190 INIT_LIST_HEAD(&t->target_callbacks);
193 num_targets = KEYS_PER_NODE;
195 num_targets = dm_round_up(num_targets, KEYS_PER_NODE);
202 if (alloc_targets(t, num_targets)) {
213 static void free_devices(struct list_head *devices, struct mapped_device *md)
215 struct list_head *tmp, *next;
217 list_for_each_safe(tmp, next, devices) {
218 struct dm_dev_internal *dd =
219 list_entry(tmp, struct dm_dev_internal, list);
220 DMWARN("%s: dm_table_destroy: dm_put_device call missing for %s",
221 dm_device_name(md), dd->dm_dev->name);
222 dm_put_table_device(md, dd->dm_dev);
227 void dm_table_destroy(struct dm_table *t)
234 /* free the indexes */
236 vfree(t->index[t->depth - 2]);
238 /* free the targets */
239 for (i = 0; i < t->num_targets; i++) {
240 struct dm_target *tgt = t->targets + i;
245 dm_put_target_type(tgt->type);
250 /* free the device list */
251 free_devices(&t->devices, t->md);
253 dm_free_md_mempools(t->mempools);
259 * See if we've already got a device in the list.
261 static struct dm_dev_internal *find_device(struct list_head *l, dev_t dev)
263 struct dm_dev_internal *dd;
265 list_for_each_entry (dd, l, list)
266 if (dd->dm_dev->bdev->bd_dev == dev)
273 * If possible, this checks an area of a destination device is invalid.
275 static int device_area_is_invalid(struct dm_target *ti, struct dm_dev *dev,
276 sector_t start, sector_t len, void *data)
278 struct request_queue *q;
279 struct queue_limits *limits = data;
280 struct block_device *bdev = dev->bdev;
282 i_size_read(bdev->bd_inode) >> SECTOR_SHIFT;
283 unsigned short logical_block_size_sectors =
284 limits->logical_block_size >> SECTOR_SHIFT;
285 char b[BDEVNAME_SIZE];
288 * Some devices exist without request functions,
289 * such as loop devices not yet bound to backing files.
290 * Forbid the use of such devices.
292 q = bdev_get_queue(bdev);
293 if (!q || !q->make_request_fn) {
294 DMWARN("%s: %s is not yet initialised: "
295 "start=%llu, len=%llu, dev_size=%llu",
296 dm_device_name(ti->table->md), bdevname(bdev, b),
297 (unsigned long long)start,
298 (unsigned long long)len,
299 (unsigned long long)dev_size);
306 if ((start >= dev_size) || (start + len > dev_size)) {
307 DMWARN("%s: %s too small for target: "
308 "start=%llu, len=%llu, dev_size=%llu",
309 dm_device_name(ti->table->md), bdevname(bdev, b),
310 (unsigned long long)start,
311 (unsigned long long)len,
312 (unsigned long long)dev_size);
316 if (logical_block_size_sectors <= 1)
319 if (start & (logical_block_size_sectors - 1)) {
320 DMWARN("%s: start=%llu not aligned to h/w "
321 "logical block size %u of %s",
322 dm_device_name(ti->table->md),
323 (unsigned long long)start,
324 limits->logical_block_size, bdevname(bdev, b));
328 if (len & (logical_block_size_sectors - 1)) {
329 DMWARN("%s: len=%llu not aligned to h/w "
330 "logical block size %u of %s",
331 dm_device_name(ti->table->md),
332 (unsigned long long)len,
333 limits->logical_block_size, bdevname(bdev, b));
341 * This upgrades the mode on an already open dm_dev, being
342 * careful to leave things as they were if we fail to reopen the
343 * device and not to touch the existing bdev field in case
344 * it is accessed concurrently inside dm_table_any_congested().
346 static int upgrade_mode(struct dm_dev_internal *dd, fmode_t new_mode,
347 struct mapped_device *md)
350 struct dm_dev *old_dev, *new_dev;
352 old_dev = dd->dm_dev;
354 r = dm_get_table_device(md, dd->dm_dev->bdev->bd_dev,
355 dd->dm_dev->mode | new_mode, &new_dev);
359 dd->dm_dev = new_dev;
360 dm_put_table_device(md, old_dev);
366 * Add a device to the list, or just increment the usage count if
367 * it's already present.
369 int dm_get_device(struct dm_target *ti, const char *path, fmode_t mode,
370 struct dm_dev **result)
373 dev_t uninitialized_var(dev);
374 struct dm_dev_internal *dd;
375 unsigned int major, minor;
376 struct dm_table *t = ti->table;
381 if (sscanf(path, "%u:%u%c", &major, &minor, &dummy) == 2) {
382 /* Extract the major/minor numbers */
383 dev = MKDEV(major, minor);
384 if (MAJOR(dev) != major || MINOR(dev) != minor)
387 /* convert the path to a device */
388 struct block_device *bdev = lookup_bdev(path);
391 return PTR_ERR(bdev);
396 dd = find_device(&t->devices, dev);
398 dd = kmalloc(sizeof(*dd), GFP_KERNEL);
402 if ((r = dm_get_table_device(t->md, dev, mode, &dd->dm_dev))) {
407 atomic_set(&dd->count, 0);
408 list_add(&dd->list, &t->devices);
410 } else if (dd->dm_dev->mode != (mode | dd->dm_dev->mode)) {
411 r = upgrade_mode(dd, mode, t->md);
415 atomic_inc(&dd->count);
417 *result = dd->dm_dev;
420 EXPORT_SYMBOL(dm_get_device);
422 static int dm_set_device_limits(struct dm_target *ti, struct dm_dev *dev,
423 sector_t start, sector_t len, void *data)
425 struct queue_limits *limits = data;
426 struct block_device *bdev = dev->bdev;
427 struct request_queue *q = bdev_get_queue(bdev);
428 char b[BDEVNAME_SIZE];
431 DMWARN("%s: Cannot set limits for nonexistent device %s",
432 dm_device_name(ti->table->md), bdevname(bdev, b));
436 if (bdev_stack_limits(limits, bdev, start) < 0)
437 DMWARN("%s: adding target device %s caused an alignment inconsistency: "
438 "physical_block_size=%u, logical_block_size=%u, "
439 "alignment_offset=%u, start=%llu",
440 dm_device_name(ti->table->md), bdevname(bdev, b),
441 q->limits.physical_block_size,
442 q->limits.logical_block_size,
443 q->limits.alignment_offset,
444 (unsigned long long) start << SECTOR_SHIFT);
447 * Check if merge fn is supported.
448 * If not we'll force DM to use PAGE_SIZE or
449 * smaller I/O, just to be safe.
451 if (dm_queue_merge_is_compulsory(q) && !ti->type->merge)
452 blk_limits_max_hw_sectors(limits,
453 (unsigned int) (PAGE_SIZE >> 9));
458 * Decrement a device's use count and remove it if necessary.
460 void dm_put_device(struct dm_target *ti, struct dm_dev *d)
463 struct list_head *devices = &ti->table->devices;
464 struct dm_dev_internal *dd;
466 list_for_each_entry(dd, devices, list) {
467 if (dd->dm_dev == d) {
473 DMWARN("%s: device %s not in table devices list",
474 dm_device_name(ti->table->md), d->name);
477 if (atomic_dec_and_test(&dd->count)) {
478 dm_put_table_device(ti->table->md, d);
483 EXPORT_SYMBOL(dm_put_device);
486 * Checks to see if the target joins onto the end of the table.
488 static int adjoin(struct dm_table *table, struct dm_target *ti)
490 struct dm_target *prev;
492 if (!table->num_targets)
495 prev = &table->targets[table->num_targets - 1];
496 return (ti->begin == (prev->begin + prev->len));
500 * Used to dynamically allocate the arg array.
502 * We do first allocation with GFP_NOIO because dm-mpath and dm-thin must
503 * process messages even if some device is suspended. These messages have a
504 * small fixed number of arguments.
506 * On the other hand, dm-switch needs to process bulk data using messages and
507 * excessive use of GFP_NOIO could cause trouble.
509 static char **realloc_argv(unsigned *array_size, char **old_argv)
516 new_size = *array_size * 2;
522 argv = kmalloc(new_size * sizeof(*argv), gfp);
524 memcpy(argv, old_argv, *array_size * sizeof(*argv));
525 *array_size = new_size;
533 * Destructively splits up the argument list to pass to ctr.
535 int dm_split_args(int *argc, char ***argvp, char *input)
537 char *start, *end = input, *out, **argv = NULL;
538 unsigned array_size = 0;
547 argv = realloc_argv(&array_size, argv);
552 /* Skip whitespace */
553 start = skip_spaces(end);
556 break; /* success, we hit the end */
558 /* 'out' is used to remove any back-quotes */
561 /* Everything apart from '\0' can be quoted */
562 if (*end == '\\' && *(end + 1)) {
569 break; /* end of token */
574 /* have we already filled the array ? */
575 if ((*argc + 1) > array_size) {
576 argv = realloc_argv(&array_size, argv);
581 /* we know this is whitespace */
585 /* terminate the string and put it in the array */
596 * Impose necessary and sufficient conditions on a devices's table such
597 * that any incoming bio which respects its logical_block_size can be
598 * processed successfully. If it falls across the boundary between
599 * two or more targets, the size of each piece it gets split into must
600 * be compatible with the logical_block_size of the target processing it.
602 static int validate_hardware_logical_block_alignment(struct dm_table *table,
603 struct queue_limits *limits)
606 * This function uses arithmetic modulo the logical_block_size
607 * (in units of 512-byte sectors).
609 unsigned short device_logical_block_size_sects =
610 limits->logical_block_size >> SECTOR_SHIFT;
613 * Offset of the start of the next table entry, mod logical_block_size.
615 unsigned short next_target_start = 0;
618 * Given an aligned bio that extends beyond the end of a
619 * target, how many sectors must the next target handle?
621 unsigned short remaining = 0;
623 struct dm_target *uninitialized_var(ti);
624 struct queue_limits ti_limits;
628 * Check each entry in the table in turn.
630 while (i < dm_table_get_num_targets(table)) {
631 ti = dm_table_get_target(table, i++);
633 blk_set_stacking_limits(&ti_limits);
635 /* combine all target devices' limits */
636 if (ti->type->iterate_devices)
637 ti->type->iterate_devices(ti, dm_set_device_limits,
641 * If the remaining sectors fall entirely within this
642 * table entry are they compatible with its logical_block_size?
644 if (remaining < ti->len &&
645 remaining & ((ti_limits.logical_block_size >>
650 (unsigned short) ((next_target_start + ti->len) &
651 (device_logical_block_size_sects - 1));
652 remaining = next_target_start ?
653 device_logical_block_size_sects - next_target_start : 0;
657 DMWARN("%s: table line %u (start sect %llu len %llu) "
658 "not aligned to h/w logical block size %u",
659 dm_device_name(table->md), i,
660 (unsigned long long) ti->begin,
661 (unsigned long long) ti->len,
662 limits->logical_block_size);
669 int dm_table_add_target(struct dm_table *t, const char *type,
670 sector_t start, sector_t len, char *params)
672 int r = -EINVAL, argc;
674 struct dm_target *tgt;
677 DMERR("%s: target type %s must appear alone in table",
678 dm_device_name(t->md), t->targets->type->name);
682 BUG_ON(t->num_targets >= t->num_allocated);
684 tgt = t->targets + t->num_targets;
685 memset(tgt, 0, sizeof(*tgt));
688 DMERR("%s: zero-length target", dm_device_name(t->md));
692 tgt->type = dm_get_target_type(type);
694 DMERR("%s: %s: unknown target type", dm_device_name(t->md),
699 if (dm_target_needs_singleton(tgt->type)) {
700 if (t->num_targets) {
701 DMERR("%s: target type %s must appear alone in table",
702 dm_device_name(t->md), type);
708 if (dm_target_always_writeable(tgt->type) && !(t->mode & FMODE_WRITE)) {
709 DMERR("%s: target type %s may not be included in read-only tables",
710 dm_device_name(t->md), type);
714 if (t->immutable_target_type) {
715 if (t->immutable_target_type != tgt->type) {
716 DMERR("%s: immutable target type %s cannot be mixed with other target types",
717 dm_device_name(t->md), t->immutable_target_type->name);
720 } else if (dm_target_is_immutable(tgt->type)) {
721 if (t->num_targets) {
722 DMERR("%s: immutable target type %s cannot be mixed with other target types",
723 dm_device_name(t->md), tgt->type->name);
726 t->immutable_target_type = tgt->type;
732 tgt->error = "Unknown error";
735 * Does this target adjoin the previous one ?
737 if (!adjoin(t, tgt)) {
738 tgt->error = "Gap in table";
743 r = dm_split_args(&argc, &argv, params);
745 tgt->error = "couldn't split parameters (insufficient memory)";
749 r = tgt->type->ctr(tgt, argc, argv);
754 t->highs[t->num_targets++] = tgt->begin + tgt->len - 1;
756 if (!tgt->num_discard_bios && tgt->discards_supported)
757 DMWARN("%s: %s: ignoring discards_supported because num_discard_bios is zero.",
758 dm_device_name(t->md), type);
763 DMERR("%s: %s: %s", dm_device_name(t->md), type, tgt->error);
764 dm_put_target_type(tgt->type);
769 * Target argument parsing helpers.
771 static int validate_next_arg(struct dm_arg *arg, struct dm_arg_set *arg_set,
772 unsigned *value, char **error, unsigned grouped)
774 const char *arg_str = dm_shift_arg(arg_set);
778 (sscanf(arg_str, "%u%c", value, &dummy) != 1) ||
779 (*value < arg->min) ||
780 (*value > arg->max) ||
781 (grouped && arg_set->argc < *value)) {
789 int dm_read_arg(struct dm_arg *arg, struct dm_arg_set *arg_set,
790 unsigned *value, char **error)
792 return validate_next_arg(arg, arg_set, value, error, 0);
794 EXPORT_SYMBOL(dm_read_arg);
796 int dm_read_arg_group(struct dm_arg *arg, struct dm_arg_set *arg_set,
797 unsigned *value, char **error)
799 return validate_next_arg(arg, arg_set, value, error, 1);
801 EXPORT_SYMBOL(dm_read_arg_group);
803 const char *dm_shift_arg(struct dm_arg_set *as)
816 EXPORT_SYMBOL(dm_shift_arg);
818 void dm_consume_args(struct dm_arg_set *as, unsigned num_args)
820 BUG_ON(as->argc < num_args);
821 as->argc -= num_args;
822 as->argv += num_args;
824 EXPORT_SYMBOL(dm_consume_args);
826 static int dm_table_set_type(struct dm_table *t)
829 unsigned bio_based = 0, request_based = 0, hybrid = 0;
830 bool use_blk_mq = false;
831 struct dm_target *tgt;
832 struct dm_dev_internal *dd;
833 struct list_head *devices;
834 unsigned live_md_type = dm_get_md_type(t->md);
836 for (i = 0; i < t->num_targets; i++) {
837 tgt = t->targets + i;
838 if (dm_target_hybrid(tgt))
840 else if (dm_target_request_based(tgt))
845 if (bio_based && request_based) {
846 DMWARN("Inconsistent table: different target types"
847 " can't be mixed up");
852 if (hybrid && !bio_based && !request_based) {
854 * The targets can work either way.
855 * Determine the type from the live device.
856 * Default to bio-based if device is new.
858 if (live_md_type == DM_TYPE_REQUEST_BASED ||
859 live_md_type == DM_TYPE_MQ_REQUEST_BASED)
866 /* We must use this table as bio-based */
867 t->type = DM_TYPE_BIO_BASED;
871 BUG_ON(!request_based); /* No targets in this table */
874 * Request-based dm supports only tables that have a single target now.
875 * To support multiple targets, request splitting support is needed,
876 * and that needs lots of changes in the block-layer.
877 * (e.g. request completion process for partial completion.)
879 if (t->num_targets > 1) {
880 DMWARN("Request-based dm doesn't support multiple targets yet");
884 /* Non-request-stackable devices can't be used for request-based dm */
885 devices = dm_table_get_devices(t);
886 list_for_each_entry(dd, devices, list) {
887 struct request_queue *q = bdev_get_queue(dd->dm_dev->bdev);
889 if (!blk_queue_stackable(q)) {
890 DMERR("table load rejected: including"
891 " non-request-stackable devices");
900 /* verify _all_ devices in the table are blk-mq devices */
901 list_for_each_entry(dd, devices, list)
902 if (!bdev_get_queue(dd->dm_dev->bdev)->mq_ops) {
903 DMERR("table load rejected: not all devices"
904 " are blk-mq request-stackable");
907 t->type = DM_TYPE_MQ_REQUEST_BASED;
909 } else if (hybrid && list_empty(devices) && live_md_type != DM_TYPE_NONE) {
910 /* inherit live MD type */
911 t->type = live_md_type;
914 t->type = DM_TYPE_REQUEST_BASED;
919 unsigned dm_table_get_type(struct dm_table *t)
924 struct target_type *dm_table_get_immutable_target_type(struct dm_table *t)
926 return t->immutable_target_type;
929 bool dm_table_request_based(struct dm_table *t)
931 unsigned table_type = dm_table_get_type(t);
933 return (table_type == DM_TYPE_REQUEST_BASED ||
934 table_type == DM_TYPE_MQ_REQUEST_BASED);
937 bool dm_table_mq_request_based(struct dm_table *t)
939 return dm_table_get_type(t) == DM_TYPE_MQ_REQUEST_BASED;
942 static int dm_table_alloc_md_mempools(struct dm_table *t)
944 unsigned type = dm_table_get_type(t);
945 unsigned per_bio_data_size = 0;
946 struct dm_target *tgt;
949 if (unlikely(type == DM_TYPE_NONE)) {
950 DMWARN("no table type is set, can't allocate mempools");
954 if (type == DM_TYPE_BIO_BASED)
955 for (i = 0; i < t->num_targets; i++) {
956 tgt = t->targets + i;
957 per_bio_data_size = max(per_bio_data_size, tgt->per_bio_data_size);
960 t->mempools = dm_alloc_md_mempools(type, t->integrity_supported, per_bio_data_size);
967 void dm_table_free_md_mempools(struct dm_table *t)
969 dm_free_md_mempools(t->mempools);
973 struct dm_md_mempools *dm_table_get_md_mempools(struct dm_table *t)
978 static int setup_indexes(struct dm_table *t)
981 unsigned int total = 0;
984 /* allocate the space for *all* the indexes */
985 for (i = t->depth - 2; i >= 0; i--) {
986 t->counts[i] = dm_div_up(t->counts[i + 1], CHILDREN_PER_NODE);
987 total += t->counts[i];
990 indexes = (sector_t *) dm_vcalloc(total, (unsigned long) NODE_SIZE);
994 /* set up internal nodes, bottom-up */
995 for (i = t->depth - 2; i >= 0; i--) {
996 t->index[i] = indexes;
997 indexes += (KEYS_PER_NODE * t->counts[i]);
998 setup_btree_index(i, t);
1005 * Builds the btree to index the map.
1007 static int dm_table_build_index(struct dm_table *t)
1010 unsigned int leaf_nodes;
1012 /* how many indexes will the btree have ? */
1013 leaf_nodes = dm_div_up(t->num_targets, KEYS_PER_NODE);
1014 t->depth = 1 + int_log(leaf_nodes, CHILDREN_PER_NODE);
1016 /* leaf layer has already been set up */
1017 t->counts[t->depth - 1] = leaf_nodes;
1018 t->index[t->depth - 1] = t->highs;
1021 r = setup_indexes(t);
1027 * Get a disk whose integrity profile reflects the table's profile.
1028 * If %match_all is true, all devices' profiles must match.
1029 * If %match_all is false, all devices must at least have an
1030 * allocated integrity profile; but uninitialized is ok.
1031 * Returns NULL if integrity support was inconsistent or unavailable.
1033 static struct gendisk * dm_table_get_integrity_disk(struct dm_table *t,
1036 struct list_head *devices = dm_table_get_devices(t);
1037 struct dm_dev_internal *dd = NULL;
1038 struct gendisk *prev_disk = NULL, *template_disk = NULL;
1040 list_for_each_entry(dd, devices, list) {
1041 template_disk = dd->dm_dev->bdev->bd_disk;
1042 if (!blk_get_integrity(template_disk))
1044 if (!match_all && !blk_integrity_is_initialized(template_disk))
1045 continue; /* skip uninitialized profiles */
1046 else if (prev_disk &&
1047 blk_integrity_compare(prev_disk, template_disk) < 0)
1049 prev_disk = template_disk;
1052 return template_disk;
1056 DMWARN("%s: integrity not set: %s and %s profile mismatch",
1057 dm_device_name(t->md),
1058 prev_disk->disk_name,
1059 template_disk->disk_name);
1064 * Register the mapped device for blk_integrity support if
1065 * the underlying devices have an integrity profile. But all devices
1066 * may not have matching profiles (checking all devices isn't reliable
1067 * during table load because this table may use other DM device(s) which
1068 * must be resumed before they will have an initialized integity profile).
1069 * Stacked DM devices force a 2 stage integrity profile validation:
1070 * 1 - during load, validate all initialized integrity profiles match
1071 * 2 - during resume, validate all integrity profiles match
1073 static int dm_table_prealloc_integrity(struct dm_table *t, struct mapped_device *md)
1075 struct gendisk *template_disk = NULL;
1077 template_disk = dm_table_get_integrity_disk(t, false);
1081 if (!blk_integrity_is_initialized(dm_disk(md))) {
1082 t->integrity_supported = 1;
1083 return blk_integrity_register(dm_disk(md), NULL);
1087 * If DM device already has an initalized integrity
1088 * profile the new profile should not conflict.
1090 if (blk_integrity_is_initialized(template_disk) &&
1091 blk_integrity_compare(dm_disk(md), template_disk) < 0) {
1092 DMWARN("%s: conflict with existing integrity profile: "
1093 "%s profile mismatch",
1094 dm_device_name(t->md),
1095 template_disk->disk_name);
1099 /* Preserve existing initialized integrity profile */
1100 t->integrity_supported = 1;
1105 * Prepares the table for use by building the indices,
1106 * setting the type, and allocating mempools.
1108 int dm_table_complete(struct dm_table *t)
1112 r = dm_table_set_type(t);
1114 DMERR("unable to set table type");
1118 r = dm_table_build_index(t);
1120 DMERR("unable to build btrees");
1124 r = dm_table_prealloc_integrity(t, t->md);
1126 DMERR("could not register integrity profile.");
1130 r = dm_table_alloc_md_mempools(t);
1132 DMERR("unable to allocate mempools");
1137 static DEFINE_MUTEX(_event_lock);
1138 void dm_table_event_callback(struct dm_table *t,
1139 void (*fn)(void *), void *context)
1141 mutex_lock(&_event_lock);
1143 t->event_context = context;
1144 mutex_unlock(&_event_lock);
1147 void dm_table_event(struct dm_table *t)
1150 * You can no longer call dm_table_event() from interrupt
1151 * context, use a bottom half instead.
1153 BUG_ON(in_interrupt());
1155 mutex_lock(&_event_lock);
1157 t->event_fn(t->event_context);
1158 mutex_unlock(&_event_lock);
1160 EXPORT_SYMBOL(dm_table_event);
1162 sector_t dm_table_get_size(struct dm_table *t)
1164 return t->num_targets ? (t->highs[t->num_targets - 1] + 1) : 0;
1166 EXPORT_SYMBOL(dm_table_get_size);
1168 struct dm_target *dm_table_get_target(struct dm_table *t, unsigned int index)
1170 if (index >= t->num_targets)
1173 return t->targets + index;
1177 * Search the btree for the correct target.
1179 * Caller should check returned pointer with dm_target_is_valid()
1180 * to trap I/O beyond end of device.
1182 struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector)
1184 unsigned int l, n = 0, k = 0;
1187 for (l = 0; l < t->depth; l++) {
1188 n = get_child(n, k);
1189 node = get_node(t, l, n);
1191 for (k = 0; k < KEYS_PER_NODE; k++)
1192 if (node[k] >= sector)
1196 return &t->targets[(KEYS_PER_NODE * n) + k];
1199 static int count_device(struct dm_target *ti, struct dm_dev *dev,
1200 sector_t start, sector_t len, void *data)
1202 unsigned *num_devices = data;
1210 * Check whether a table has no data devices attached using each
1211 * target's iterate_devices method.
1212 * Returns false if the result is unknown because a target doesn't
1213 * support iterate_devices.
1215 bool dm_table_has_no_data_devices(struct dm_table *table)
1217 struct dm_target *uninitialized_var(ti);
1218 unsigned i = 0, num_devices = 0;
1220 while (i < dm_table_get_num_targets(table)) {
1221 ti = dm_table_get_target(table, i++);
1223 if (!ti->type->iterate_devices)
1226 ti->type->iterate_devices(ti, count_device, &num_devices);
1235 * Establish the new table's queue_limits and validate them.
1237 int dm_calculate_queue_limits(struct dm_table *table,
1238 struct queue_limits *limits)
1240 struct dm_target *uninitialized_var(ti);
1241 struct queue_limits ti_limits;
1244 blk_set_stacking_limits(limits);
1246 while (i < dm_table_get_num_targets(table)) {
1247 blk_set_stacking_limits(&ti_limits);
1249 ti = dm_table_get_target(table, i++);
1251 if (!ti->type->iterate_devices)
1252 goto combine_limits;
1255 * Combine queue limits of all the devices this target uses.
1257 ti->type->iterate_devices(ti, dm_set_device_limits,
1260 /* Set I/O hints portion of queue limits */
1261 if (ti->type->io_hints)
1262 ti->type->io_hints(ti, &ti_limits);
1265 * Check each device area is consistent with the target's
1266 * overall queue limits.
1268 if (ti->type->iterate_devices(ti, device_area_is_invalid,
1274 * Merge this target's queue limits into the overall limits
1277 if (blk_stack_limits(limits, &ti_limits, 0) < 0)
1278 DMWARN("%s: adding target device "
1279 "(start sect %llu len %llu) "
1280 "caused an alignment inconsistency",
1281 dm_device_name(table->md),
1282 (unsigned long long) ti->begin,
1283 (unsigned long long) ti->len);
1286 return validate_hardware_logical_block_alignment(table, limits);
1290 * Set the integrity profile for this device if all devices used have
1291 * matching profiles. We're quite deep in the resume path but still
1292 * don't know if all devices (particularly DM devices this device
1293 * may be stacked on) have matching profiles. Even if the profiles
1294 * don't match we have no way to fail (to resume) at this point.
1296 static void dm_table_set_integrity(struct dm_table *t)
1298 struct gendisk *template_disk = NULL;
1300 if (!blk_get_integrity(dm_disk(t->md)))
1303 template_disk = dm_table_get_integrity_disk(t, true);
1305 blk_integrity_register(dm_disk(t->md),
1306 blk_get_integrity(template_disk));
1307 else if (blk_integrity_is_initialized(dm_disk(t->md)))
1308 DMWARN("%s: device no longer has a valid integrity profile",
1309 dm_device_name(t->md));
1311 DMWARN("%s: unable to establish an integrity profile",
1312 dm_device_name(t->md));
1315 static int device_flush_capable(struct dm_target *ti, struct dm_dev *dev,
1316 sector_t start, sector_t len, void *data)
1318 unsigned flush = (*(unsigned *)data);
1319 struct request_queue *q = bdev_get_queue(dev->bdev);
1321 return q && (q->flush_flags & flush);
1324 static bool dm_table_supports_flush(struct dm_table *t, unsigned flush)
1326 struct dm_target *ti;
1330 * Require at least one underlying device to support flushes.
1331 * t->devices includes internal dm devices such as mirror logs
1332 * so we need to use iterate_devices here, which targets
1333 * supporting flushes must provide.
1335 while (i < dm_table_get_num_targets(t)) {
1336 ti = dm_table_get_target(t, i++);
1338 if (!ti->num_flush_bios)
1341 if (ti->flush_supported)
1344 if (ti->type->iterate_devices &&
1345 ti->type->iterate_devices(ti, device_flush_capable, &flush))
1352 static bool dm_table_discard_zeroes_data(struct dm_table *t)
1354 struct dm_target *ti;
1357 /* Ensure that all targets supports discard_zeroes_data. */
1358 while (i < dm_table_get_num_targets(t)) {
1359 ti = dm_table_get_target(t, i++);
1361 if (ti->discard_zeroes_data_unsupported)
1368 static int device_is_nonrot(struct dm_target *ti, struct dm_dev *dev,
1369 sector_t start, sector_t len, void *data)
1371 struct request_queue *q = bdev_get_queue(dev->bdev);
1373 return q && blk_queue_nonrot(q);
1376 static int device_is_not_random(struct dm_target *ti, struct dm_dev *dev,
1377 sector_t start, sector_t len, void *data)
1379 struct request_queue *q = bdev_get_queue(dev->bdev);
1381 return q && !blk_queue_add_random(q);
1384 static int queue_supports_sg_merge(struct dm_target *ti, struct dm_dev *dev,
1385 sector_t start, sector_t len, void *data)
1387 struct request_queue *q = bdev_get_queue(dev->bdev);
1389 return q && !test_bit(QUEUE_FLAG_NO_SG_MERGE, &q->queue_flags);
1392 static int queue_supports_sg_gaps(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 && !test_bit(QUEUE_FLAG_SG_GAPS, &q->queue_flags);
1400 static bool dm_table_all_devices_attribute(struct dm_table *t,
1401 iterate_devices_callout_fn func)
1403 struct dm_target *ti;
1406 while (i < dm_table_get_num_targets(t)) {
1407 ti = dm_table_get_target(t, i++);
1409 if (!ti->type->iterate_devices ||
1410 !ti->type->iterate_devices(ti, func, NULL))
1417 static int device_not_write_same_capable(struct dm_target *ti, struct dm_dev *dev,
1418 sector_t start, sector_t len, void *data)
1420 struct request_queue *q = bdev_get_queue(dev->bdev);
1422 return q && !q->limits.max_write_same_sectors;
1425 static bool dm_table_supports_write_same(struct dm_table *t)
1427 struct dm_target *ti;
1430 while (i < dm_table_get_num_targets(t)) {
1431 ti = dm_table_get_target(t, i++);
1433 if (!ti->num_write_same_bios)
1436 if (!ti->type->iterate_devices ||
1437 ti->type->iterate_devices(ti, device_not_write_same_capable, NULL))
1444 static int device_discard_capable(struct dm_target *ti, struct dm_dev *dev,
1445 sector_t start, sector_t len, void *data)
1447 struct request_queue *q = bdev_get_queue(dev->bdev);
1449 return q && blk_queue_discard(q);
1452 static bool dm_table_supports_discards(struct dm_table *t)
1454 struct dm_target *ti;
1458 * Unless any target used by the table set discards_supported,
1459 * require at least one underlying device to support discards.
1460 * t->devices includes internal dm devices such as mirror logs
1461 * so we need to use iterate_devices here, which targets
1462 * supporting discard selectively must provide.
1464 while (i < dm_table_get_num_targets(t)) {
1465 ti = dm_table_get_target(t, i++);
1467 if (!ti->num_discard_bios)
1470 if (ti->discards_supported)
1473 if (ti->type->iterate_devices &&
1474 ti->type->iterate_devices(ti, device_discard_capable, NULL))
1481 void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
1482 struct queue_limits *limits)
1487 * Copy table's limits to the DM device's request_queue
1489 q->limits = *limits;
1491 if (!dm_table_supports_discards(t))
1492 queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, q);
1494 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q);
1496 if (dm_table_supports_flush(t, REQ_FLUSH)) {
1498 if (dm_table_supports_flush(t, REQ_FUA))
1501 blk_queue_flush(q, flush);
1503 if (!dm_table_discard_zeroes_data(t))
1504 q->limits.discard_zeroes_data = 0;
1506 /* Ensure that all underlying devices are non-rotational. */
1507 if (dm_table_all_devices_attribute(t, device_is_nonrot))
1508 queue_flag_set_unlocked(QUEUE_FLAG_NONROT, q);
1510 queue_flag_clear_unlocked(QUEUE_FLAG_NONROT, q);
1512 if (!dm_table_supports_write_same(t))
1513 q->limits.max_write_same_sectors = 0;
1515 if (dm_table_all_devices_attribute(t, queue_supports_sg_merge))
1516 queue_flag_clear_unlocked(QUEUE_FLAG_NO_SG_MERGE, q);
1518 queue_flag_set_unlocked(QUEUE_FLAG_NO_SG_MERGE, q);
1520 if (dm_table_all_devices_attribute(t, queue_supports_sg_gaps))
1521 queue_flag_clear_unlocked(QUEUE_FLAG_SG_GAPS, q);
1523 queue_flag_set_unlocked(QUEUE_FLAG_SG_GAPS, q);
1525 dm_table_set_integrity(t);
1528 * Determine whether or not this queue's I/O timings contribute
1529 * to the entropy pool, Only request-based targets use this.
1530 * Clear QUEUE_FLAG_ADD_RANDOM if any underlying device does not
1533 if (blk_queue_add_random(q) && dm_table_all_devices_attribute(t, device_is_not_random))
1534 queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, q);
1537 * QUEUE_FLAG_STACKABLE must be set after all queue settings are
1538 * visible to other CPUs because, once the flag is set, incoming bios
1539 * are processed by request-based dm, which refers to the queue
1541 * Until the flag set, bios are passed to bio-based dm and queued to
1542 * md->deferred where queue settings are not needed yet.
1543 * Those bios are passed to request-based dm at the resume time.
1546 if (dm_table_request_based(t))
1547 queue_flag_set_unlocked(QUEUE_FLAG_STACKABLE, q);
1550 unsigned int dm_table_get_num_targets(struct dm_table *t)
1552 return t->num_targets;
1555 struct list_head *dm_table_get_devices(struct dm_table *t)
1560 fmode_t dm_table_get_mode(struct dm_table *t)
1564 EXPORT_SYMBOL(dm_table_get_mode);
1572 static void suspend_targets(struct dm_table *t, enum suspend_mode mode)
1574 int i = t->num_targets;
1575 struct dm_target *ti = t->targets;
1580 if (ti->type->presuspend)
1581 ti->type->presuspend(ti);
1583 case PRESUSPEND_UNDO:
1584 if (ti->type->presuspend_undo)
1585 ti->type->presuspend_undo(ti);
1588 if (ti->type->postsuspend)
1589 ti->type->postsuspend(ti);
1596 void dm_table_presuspend_targets(struct dm_table *t)
1601 suspend_targets(t, PRESUSPEND);
1604 void dm_table_presuspend_undo_targets(struct dm_table *t)
1609 suspend_targets(t, PRESUSPEND_UNDO);
1612 void dm_table_postsuspend_targets(struct dm_table *t)
1617 suspend_targets(t, POSTSUSPEND);
1620 int dm_table_resume_targets(struct dm_table *t)
1624 for (i = 0; i < t->num_targets; i++) {
1625 struct dm_target *ti = t->targets + i;
1627 if (!ti->type->preresume)
1630 r = ti->type->preresume(ti);
1632 DMERR("%s: %s: preresume failed, error = %d",
1633 dm_device_name(t->md), ti->type->name, r);
1638 for (i = 0; i < t->num_targets; i++) {
1639 struct dm_target *ti = t->targets + i;
1641 if (ti->type->resume)
1642 ti->type->resume(ti);
1648 void dm_table_add_target_callbacks(struct dm_table *t, struct dm_target_callbacks *cb)
1650 list_add(&cb->list, &t->target_callbacks);
1652 EXPORT_SYMBOL_GPL(dm_table_add_target_callbacks);
1654 int dm_table_any_congested(struct dm_table *t, int bdi_bits)
1656 struct dm_dev_internal *dd;
1657 struct list_head *devices = dm_table_get_devices(t);
1658 struct dm_target_callbacks *cb;
1661 list_for_each_entry(dd, devices, list) {
1662 struct request_queue *q = bdev_get_queue(dd->dm_dev->bdev);
1663 char b[BDEVNAME_SIZE];
1666 r |= bdi_congested(&q->backing_dev_info, bdi_bits);
1668 DMWARN_LIMIT("%s: any_congested: nonexistent device %s",
1669 dm_device_name(t->md),
1670 bdevname(dd->dm_dev->bdev, b));
1673 list_for_each_entry(cb, &t->target_callbacks, list)
1674 if (cb->congested_fn)
1675 r |= cb->congested_fn(cb, bdi_bits);
1680 int dm_table_any_busy_target(struct dm_table *t)
1683 struct dm_target *ti;
1685 for (i = 0; i < t->num_targets; i++) {
1686 ti = t->targets + i;
1687 if (ti->type->busy && ti->type->busy(ti))
1694 struct mapped_device *dm_table_get_md(struct dm_table *t)
1698 EXPORT_SYMBOL(dm_table_get_md);
1700 void dm_table_run_md_queue_async(struct dm_table *t)
1702 struct mapped_device *md;
1703 struct request_queue *queue;
1704 unsigned long flags;
1706 if (!dm_table_request_based(t))
1709 md = dm_table_get_md(t);
1710 queue = dm_get_md_queue(md);
1712 spin_lock_irqsave(queue->queue_lock, flags);
1713 blk_run_queue_async(queue);
1714 spin_unlock_irqrestore(queue->queue_lock, flags);
1717 EXPORT_SYMBOL(dm_table_run_md_queue_async);