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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Copyright (C) 2011-2012 Red Hat, Inc.4 *5 * This file is released under the GPL.6 */7 8#include "dm-thin-metadata.h"9#include "persistent-data/dm-btree.h"10#include "persistent-data/dm-space-map.h"11#include "persistent-data/dm-space-map-disk.h"12#include "persistent-data/dm-transaction-manager.h"13 14#include <linux/list.h>15#include <linux/device-mapper.h>16#include <linux/workqueue.h>17 18/*19 *--------------------------------------------------------------------------20 * As far as the metadata goes, there is:21 *22 * - A superblock in block zero, taking up fewer than 512 bytes for23 * atomic writes.24 *25 * - A space map managing the metadata blocks.26 *27 * - A space map managing the data blocks.28 *29 * - A btree mapping our internal thin dev ids onto struct disk_device_details.30 *31 * - A hierarchical btree, with 2 levels which effectively maps (thin32 * dev id, virtual block) -> block_time. Block time is a 64-bit33 * field holding the time in the low 24 bits, and block in the top 4034 * bits.35 *36 * BTrees consist solely of btree_nodes, that fill a block. Some are37 * internal nodes, as such their values are a __le64 pointing to other38 * nodes. Leaf nodes can store data of any reasonable size (ie. much39 * smaller than the block size). The nodes consist of the header,40 * followed by an array of keys, followed by an array of values. We have41 * to binary search on the keys so they're all held together to help the42 * cpu cache.43 *44 * Space maps have 2 btrees:45 *46 * - One maps a uint64_t onto a struct index_entry. Which points to a47 * bitmap block, and has some details about how many free entries there48 * are etc.49 *50 * - The bitmap blocks have a header (for the checksum). Then the rest51 * of the block is pairs of bits. With the meaning being:52 *53 * 0 - ref count is 054 * 1 - ref count is 155 * 2 - ref count is 256 * 3 - ref count is higher than 257 *58 * - If the count is higher than 2 then the ref count is entered in a59 * second btree that directly maps the block_address to a uint32_t ref60 * count.61 *62 * The space map metadata variant doesn't have a bitmaps btree. Instead63 * it has one single blocks worth of index_entries. This avoids64 * recursive issues with the bitmap btree needing to allocate space in65 * order to insert. With a small data block size such as 64k the66 * metadata support data devices that are hundreds of terrabytes.67 *68 * The space maps allocate space linearly from front to back. Space that69 * is freed in a transaction is never recycled within that transaction.70 * To try and avoid fragmenting _free_ space the allocator always goes71 * back and fills in gaps.72 *73 * All metadata io is in THIN_METADATA_BLOCK_SIZE sized/aligned chunks74 * from the block manager.75 *--------------------------------------------------------------------------76 */77 78#define DM_MSG_PREFIX "thin metadata"79 80#define THIN_SUPERBLOCK_MAGIC 2702201081#define THIN_SUPERBLOCK_LOCATION 082#define THIN_VERSION 283#define SECTOR_TO_BLOCK_SHIFT 384 85/*86 * For btree insert:87 * 3 for btree insert +88 * 2 for btree lookup used within space map89 * For btree remove:90 * 2 for shadow spine +91 * 4 for rebalance 3 child node92 */93#define THIN_MAX_CONCURRENT_LOCKS 694 95/* This should be plenty */96#define SPACE_MAP_ROOT_SIZE 12897 98/*99 * Little endian on-disk superblock and device details.100 */101struct thin_disk_superblock {102 __le32 csum; /* Checksum of superblock except for this field. */103 __le32 flags;104 __le64 blocknr; /* This block number, dm_block_t. */105 106 __u8 uuid[16];107 __le64 magic;108 __le32 version;109 __le32 time;110 111 __le64 trans_id;112 113 /*114 * Root held by userspace transactions.115 */116 __le64 held_root;117 118 __u8 data_space_map_root[SPACE_MAP_ROOT_SIZE];119 __u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE];120 121 /*122 * 2-level btree mapping (dev_id, (dev block, time)) -> data block123 */124 __le64 data_mapping_root;125 126 /*127 * Device detail root mapping dev_id -> device_details128 */129 __le64 device_details_root;130 131 __le32 data_block_size; /* In 512-byte sectors. */132 133 __le32 metadata_block_size; /* In 512-byte sectors. */134 __le64 metadata_nr_blocks;135 136 __le32 compat_flags;137 __le32 compat_ro_flags;138 __le32 incompat_flags;139} __packed;140 141struct disk_device_details {142 __le64 mapped_blocks;143 __le64 transaction_id; /* When created. */144 __le32 creation_time;145 __le32 snapshotted_time;146} __packed;147 148struct dm_pool_metadata {149 struct hlist_node hash;150 151 struct block_device *bdev;152 struct dm_block_manager *bm;153 struct dm_space_map *metadata_sm;154 struct dm_space_map *data_sm;155 struct dm_transaction_manager *tm;156 struct dm_transaction_manager *nb_tm;157 158 /*159 * Two-level btree.160 * First level holds thin_dev_t.161 * Second level holds mappings.162 */163 struct dm_btree_info info;164 165 /*166 * Non-blocking version of the above.167 */168 struct dm_btree_info nb_info;169 170 /*171 * Just the top level for deleting whole devices.172 */173 struct dm_btree_info tl_info;174 175 /*176 * Just the bottom level for creating new devices.177 */178 struct dm_btree_info bl_info;179 180 /*181 * Describes the device details btree.182 */183 struct dm_btree_info details_info;184 185 struct rw_semaphore root_lock;186 uint32_t time;187 dm_block_t root;188 dm_block_t details_root;189 struct list_head thin_devices;190 uint64_t trans_id;191 unsigned long flags;192 sector_t data_block_size;193 194 /*195 * Pre-commit callback.196 *197 * This allows the thin provisioning target to run a callback before198 * the metadata are committed.199 */200 dm_pool_pre_commit_fn pre_commit_fn;201 void *pre_commit_context;202 203 /*204 * We reserve a section of the metadata for commit overhead.205 * All reported space does *not* include this.206 */207 dm_block_t metadata_reserve;208 209 /*210 * Set if a transaction has to be aborted but the attempt to roll back211 * to the previous (good) transaction failed. The only pool metadata212 * operation possible in this state is the closing of the device.213 */214 bool fail_io:1;215 216 /*217 * Set once a thin-pool has been accessed through one of the interfaces218 * that imply the pool is in-service (e.g. thin devices created/deleted,219 * thin-pool message, metadata snapshots, etc).220 */221 bool in_service:1;222 223 /*224 * Reading the space map roots can fail, so we read it into these225 * buffers before the superblock is locked and updated.226 */227 __u8 data_space_map_root[SPACE_MAP_ROOT_SIZE];228 __u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE];229};230 231struct dm_thin_device {232 struct list_head list;233 struct dm_pool_metadata *pmd;234 dm_thin_id id;235 236 int open_count;237 bool changed:1;238 bool aborted_with_changes:1;239 uint64_t mapped_blocks;240 uint64_t transaction_id;241 uint32_t creation_time;242 uint32_t snapshotted_time;243};244 245/*246 *--------------------------------------------------------------247 * superblock validator248 *--------------------------------------------------------------249 */250#define SUPERBLOCK_CSUM_XOR 160774251 252static void sb_prepare_for_write(const struct dm_block_validator *v,253 struct dm_block *b,254 size_t block_size)255{256 struct thin_disk_superblock *disk_super = dm_block_data(b);257 258 disk_super->blocknr = cpu_to_le64(dm_block_location(b));259 disk_super->csum = cpu_to_le32(dm_bm_checksum(&disk_super->flags,260 block_size - sizeof(__le32),261 SUPERBLOCK_CSUM_XOR));262}263 264static int sb_check(const struct dm_block_validator *v,265 struct dm_block *b,266 size_t block_size)267{268 struct thin_disk_superblock *disk_super = dm_block_data(b);269 __le32 csum_le;270 271 if (dm_block_location(b) != le64_to_cpu(disk_super->blocknr)) {272 DMERR("%s failed: blocknr %llu: wanted %llu",273 __func__, le64_to_cpu(disk_super->blocknr),274 (unsigned long long)dm_block_location(b));275 return -ENOTBLK;276 }277 278 if (le64_to_cpu(disk_super->magic) != THIN_SUPERBLOCK_MAGIC) {279 DMERR("%s failed: magic %llu: wanted %llu",280 __func__, le64_to_cpu(disk_super->magic),281 (unsigned long long)THIN_SUPERBLOCK_MAGIC);282 return -EILSEQ;283 }284 285 csum_le = cpu_to_le32(dm_bm_checksum(&disk_super->flags,286 block_size - sizeof(__le32),287 SUPERBLOCK_CSUM_XOR));288 if (csum_le != disk_super->csum) {289 DMERR("%s failed: csum %u: wanted %u",290 __func__, le32_to_cpu(csum_le), le32_to_cpu(disk_super->csum));291 return -EILSEQ;292 }293 294 return 0;295}296 297static const struct dm_block_validator sb_validator = {298 .name = "superblock",299 .prepare_for_write = sb_prepare_for_write,300 .check = sb_check301};302 303/*304 *--------------------------------------------------------------305 * Methods for the btree value types306 *--------------------------------------------------------------307 */308static uint64_t pack_block_time(dm_block_t b, uint32_t t)309{310 return (b << 24) | t;311}312 313static void unpack_block_time(uint64_t v, dm_block_t *b, uint32_t *t)314{315 *b = v >> 24;316 *t = v & ((1 << 24) - 1);317}318 319/*320 * It's more efficient to call dm_sm_{inc,dec}_blocks as few times as321 * possible. 'with_runs' reads contiguous runs of blocks, and calls the322 * given sm function.323 */324typedef int (*run_fn)(struct dm_space_map *, dm_block_t, dm_block_t);325 326static void with_runs(struct dm_space_map *sm, const __le64 *value_le, unsigned int count, run_fn fn)327{328 uint64_t b, begin, end;329 uint32_t t;330 bool in_run = false;331 unsigned int i;332 333 for (i = 0; i < count; i++, value_le++) {334 /* We know value_le is 8 byte aligned */335 unpack_block_time(le64_to_cpu(*value_le), &b, &t);336 337 if (in_run) {338 if (b == end) {339 end++;340 } else {341 fn(sm, begin, end);342 begin = b;343 end = b + 1;344 }345 } else {346 in_run = true;347 begin = b;348 end = b + 1;349 }350 }351 352 if (in_run)353 fn(sm, begin, end);354}355 356static void data_block_inc(void *context, const void *value_le, unsigned int count)357{358 with_runs((struct dm_space_map *) context,359 (const __le64 *) value_le, count, dm_sm_inc_blocks);360}361 362static void data_block_dec(void *context, const void *value_le, unsigned int count)363{364 with_runs((struct dm_space_map *) context,365 (const __le64 *) value_le, count, dm_sm_dec_blocks);366}367 368static int data_block_equal(void *context, const void *value1_le, const void *value2_le)369{370 __le64 v1_le, v2_le;371 uint64_t b1, b2;372 uint32_t t;373 374 memcpy(&v1_le, value1_le, sizeof(v1_le));375 memcpy(&v2_le, value2_le, sizeof(v2_le));376 unpack_block_time(le64_to_cpu(v1_le), &b1, &t);377 unpack_block_time(le64_to_cpu(v2_le), &b2, &t);378 379 return b1 == b2;380}381 382static void subtree_inc(void *context, const void *value, unsigned int count)383{384 struct dm_btree_info *info = context;385 const __le64 *root_le = value;386 unsigned int i;387 388 for (i = 0; i < count; i++, root_le++)389 dm_tm_inc(info->tm, le64_to_cpu(*root_le));390}391 392static void subtree_dec(void *context, const void *value, unsigned int count)393{394 struct dm_btree_info *info = context;395 const __le64 *root_le = value;396 unsigned int i;397 398 for (i = 0; i < count; i++, root_le++)399 if (dm_btree_del(info, le64_to_cpu(*root_le)))400 DMERR("btree delete failed");401}402 403static int subtree_equal(void *context, const void *value1_le, const void *value2_le)404{405 __le64 v1_le, v2_le;406 407 memcpy(&v1_le, value1_le, sizeof(v1_le));408 memcpy(&v2_le, value2_le, sizeof(v2_le));409 410 return v1_le == v2_le;411}412 413/*----------------------------------------------------------------*/414 415/*416 * Variant that is used for in-core only changes or code that417 * shouldn't put the pool in service on its own (e.g. commit).418 */419static inline void pmd_write_lock_in_core(struct dm_pool_metadata *pmd)420 __acquires(pmd->root_lock)421{422 down_write(&pmd->root_lock);423}424 425static inline void pmd_write_lock(struct dm_pool_metadata *pmd)426{427 pmd_write_lock_in_core(pmd);428 if (unlikely(!pmd->in_service))429 pmd->in_service = true;430}431 432static inline void pmd_write_unlock(struct dm_pool_metadata *pmd)433 __releases(pmd->root_lock)434{435 up_write(&pmd->root_lock);436}437 438/*----------------------------------------------------------------*/439 440static int superblock_lock_zero(struct dm_pool_metadata *pmd,441 struct dm_block **sblock)442{443 return dm_bm_write_lock_zero(pmd->bm, THIN_SUPERBLOCK_LOCATION,444 &sb_validator, sblock);445}446 447static int superblock_lock(struct dm_pool_metadata *pmd,448 struct dm_block **sblock)449{450 return dm_bm_write_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION,451 &sb_validator, sblock);452}453 454static int __superblock_all_zeroes(struct dm_block_manager *bm, int *result)455{456 int r;457 unsigned int i;458 struct dm_block *b;459 __le64 *data_le, zero = cpu_to_le64(0);460 unsigned int block_size = dm_bm_block_size(bm) / sizeof(__le64);461 462 /*463 * We can't use a validator here - it may be all zeroes.464 */465 r = dm_bm_read_lock(bm, THIN_SUPERBLOCK_LOCATION, NULL, &b);466 if (r)467 return r;468 469 data_le = dm_block_data(b);470 *result = 1;471 for (i = 0; i < block_size; i++) {472 if (data_le[i] != zero) {473 *result = 0;474 break;475 }476 }477 478 dm_bm_unlock(b);479 480 return 0;481}482 483static void __setup_btree_details(struct dm_pool_metadata *pmd)484{485 pmd->info.tm = pmd->tm;486 pmd->info.levels = 2;487 pmd->info.value_type.context = pmd->data_sm;488 pmd->info.value_type.size = sizeof(__le64);489 pmd->info.value_type.inc = data_block_inc;490 pmd->info.value_type.dec = data_block_dec;491 pmd->info.value_type.equal = data_block_equal;492 493 memcpy(&pmd->nb_info, &pmd->info, sizeof(pmd->nb_info));494 pmd->nb_info.tm = pmd->nb_tm;495 496 pmd->tl_info.tm = pmd->tm;497 pmd->tl_info.levels = 1;498 pmd->tl_info.value_type.context = &pmd->bl_info;499 pmd->tl_info.value_type.size = sizeof(__le64);500 pmd->tl_info.value_type.inc = subtree_inc;501 pmd->tl_info.value_type.dec = subtree_dec;502 pmd->tl_info.value_type.equal = subtree_equal;503 504 pmd->bl_info.tm = pmd->tm;505 pmd->bl_info.levels = 1;506 pmd->bl_info.value_type.context = pmd->data_sm;507 pmd->bl_info.value_type.size = sizeof(__le64);508 pmd->bl_info.value_type.inc = data_block_inc;509 pmd->bl_info.value_type.dec = data_block_dec;510 pmd->bl_info.value_type.equal = data_block_equal;511 512 pmd->details_info.tm = pmd->tm;513 pmd->details_info.levels = 1;514 pmd->details_info.value_type.context = NULL;515 pmd->details_info.value_type.size = sizeof(struct disk_device_details);516 pmd->details_info.value_type.inc = NULL;517 pmd->details_info.value_type.dec = NULL;518 pmd->details_info.value_type.equal = NULL;519}520 521static int save_sm_roots(struct dm_pool_metadata *pmd)522{523 int r;524 size_t len;525 526 r = dm_sm_root_size(pmd->metadata_sm, &len);527 if (r < 0)528 return r;529 530 r = dm_sm_copy_root(pmd->metadata_sm, &pmd->metadata_space_map_root, len);531 if (r < 0)532 return r;533 534 r = dm_sm_root_size(pmd->data_sm, &len);535 if (r < 0)536 return r;537 538 return dm_sm_copy_root(pmd->data_sm, &pmd->data_space_map_root, len);539}540 541static void copy_sm_roots(struct dm_pool_metadata *pmd,542 struct thin_disk_superblock *disk)543{544 memcpy(&disk->metadata_space_map_root,545 &pmd->metadata_space_map_root,546 sizeof(pmd->metadata_space_map_root));547 548 memcpy(&disk->data_space_map_root,549 &pmd->data_space_map_root,550 sizeof(pmd->data_space_map_root));551}552 553static int __write_initial_superblock(struct dm_pool_metadata *pmd)554{555 int r;556 struct dm_block *sblock;557 struct thin_disk_superblock *disk_super;558 sector_t bdev_size = bdev_nr_sectors(pmd->bdev);559 560 if (bdev_size > THIN_METADATA_MAX_SECTORS)561 bdev_size = THIN_METADATA_MAX_SECTORS;562 563 r = dm_sm_commit(pmd->data_sm);564 if (r < 0)565 return r;566 567 r = dm_tm_pre_commit(pmd->tm);568 if (r < 0)569 return r;570 571 r = save_sm_roots(pmd);572 if (r < 0)573 return r;574 575 r = superblock_lock_zero(pmd, &sblock);576 if (r)577 return r;578 579 disk_super = dm_block_data(sblock);580 disk_super->flags = 0;581 memset(disk_super->uuid, 0, sizeof(disk_super->uuid));582 disk_super->magic = cpu_to_le64(THIN_SUPERBLOCK_MAGIC);583 disk_super->version = cpu_to_le32(THIN_VERSION);584 disk_super->time = 0;585 disk_super->trans_id = 0;586 disk_super->held_root = 0;587 588 copy_sm_roots(pmd, disk_super);589 590 disk_super->data_mapping_root = cpu_to_le64(pmd->root);591 disk_super->device_details_root = cpu_to_le64(pmd->details_root);592 disk_super->metadata_block_size = cpu_to_le32(THIN_METADATA_BLOCK_SIZE);593 disk_super->metadata_nr_blocks = cpu_to_le64(bdev_size >> SECTOR_TO_BLOCK_SHIFT);594 disk_super->data_block_size = cpu_to_le32(pmd->data_block_size);595 596 return dm_tm_commit(pmd->tm, sblock);597}598 599static int __format_metadata(struct dm_pool_metadata *pmd)600{601 int r;602 603 r = dm_tm_create_with_sm(pmd->bm, THIN_SUPERBLOCK_LOCATION,604 &pmd->tm, &pmd->metadata_sm);605 if (r < 0) {606 pmd->tm = NULL;607 pmd->metadata_sm = NULL;608 DMERR("tm_create_with_sm failed");609 return r;610 }611 612 pmd->data_sm = dm_sm_disk_create(pmd->tm, 0);613 if (IS_ERR(pmd->data_sm)) {614 DMERR("sm_disk_create failed");615 r = PTR_ERR(pmd->data_sm);616 pmd->data_sm = NULL;617 goto bad_cleanup_tm;618 }619 620 pmd->nb_tm = dm_tm_create_non_blocking_clone(pmd->tm);621 if (!pmd->nb_tm) {622 DMERR("could not create non-blocking clone tm");623 r = -ENOMEM;624 goto bad_cleanup_data_sm;625 }626 627 __setup_btree_details(pmd);628 629 r = dm_btree_empty(&pmd->info, &pmd->root);630 if (r < 0)631 goto bad_cleanup_nb_tm;632 633 r = dm_btree_empty(&pmd->details_info, &pmd->details_root);634 if (r < 0) {635 DMERR("couldn't create devices root");636 goto bad_cleanup_nb_tm;637 }638 639 r = __write_initial_superblock(pmd);640 if (r)641 goto bad_cleanup_nb_tm;642 643 return 0;644 645bad_cleanup_nb_tm:646 dm_tm_destroy(pmd->nb_tm);647 pmd->nb_tm = NULL;648bad_cleanup_data_sm:649 dm_sm_destroy(pmd->data_sm);650 pmd->data_sm = NULL;651bad_cleanup_tm:652 dm_tm_destroy(pmd->tm);653 pmd->tm = NULL;654 dm_sm_destroy(pmd->metadata_sm);655 pmd->metadata_sm = NULL;656 657 return r;658}659 660static int __check_incompat_features(struct thin_disk_superblock *disk_super,661 struct dm_pool_metadata *pmd)662{663 uint32_t features;664 665 features = le32_to_cpu(disk_super->incompat_flags) & ~THIN_FEATURE_INCOMPAT_SUPP;666 if (features) {667 DMERR("could not access metadata due to unsupported optional features (%lx).",668 (unsigned long)features);669 return -EINVAL;670 }671 672 /*673 * Check for read-only metadata to skip the following RDWR checks.674 */675 if (bdev_read_only(pmd->bdev))676 return 0;677 678 features = le32_to_cpu(disk_super->compat_ro_flags) & ~THIN_FEATURE_COMPAT_RO_SUPP;679 if (features) {680 DMERR("could not access metadata RDWR due to unsupported optional features (%lx).",681 (unsigned long)features);682 return -EINVAL;683 }684 685 return 0;686}687 688static int __open_metadata(struct dm_pool_metadata *pmd)689{690 int r;691 struct dm_block *sblock;692 struct thin_disk_superblock *disk_super;693 694 r = dm_bm_read_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION,695 &sb_validator, &sblock);696 if (r < 0) {697 DMERR("couldn't read superblock");698 return r;699 }700 701 disk_super = dm_block_data(sblock);702 703 /* Verify the data block size hasn't changed */704 if (le32_to_cpu(disk_super->data_block_size) != pmd->data_block_size) {705 DMERR("changing the data block size (from %u to %llu) is not supported",706 le32_to_cpu(disk_super->data_block_size),707 (unsigned long long)pmd->data_block_size);708 r = -EINVAL;709 goto bad_unlock_sblock;710 }711 712 r = __check_incompat_features(disk_super, pmd);713 if (r < 0)714 goto bad_unlock_sblock;715 716 r = dm_tm_open_with_sm(pmd->bm, THIN_SUPERBLOCK_LOCATION,717 disk_super->metadata_space_map_root,718 sizeof(disk_super->metadata_space_map_root),719 &pmd->tm, &pmd->metadata_sm);720 if (r < 0) {721 pmd->tm = NULL;722 pmd->metadata_sm = NULL;723 DMERR("tm_open_with_sm failed");724 goto bad_unlock_sblock;725 }726 727 pmd->data_sm = dm_sm_disk_open(pmd->tm, disk_super->data_space_map_root,728 sizeof(disk_super->data_space_map_root));729 if (IS_ERR(pmd->data_sm)) {730 DMERR("sm_disk_open failed");731 r = PTR_ERR(pmd->data_sm);732 pmd->data_sm = NULL;733 goto bad_cleanup_tm;734 }735 736 pmd->nb_tm = dm_tm_create_non_blocking_clone(pmd->tm);737 if (!pmd->nb_tm) {738 DMERR("could not create non-blocking clone tm");739 r = -ENOMEM;740 goto bad_cleanup_data_sm;741 }742 743 /*744 * For pool metadata opening process, root setting is redundant745 * because it will be set again in __begin_transaction(). But dm746 * pool aborting process really needs to get last transaction's747 * root to avoid accessing broken btree.748 */749 pmd->root = le64_to_cpu(disk_super->data_mapping_root);750 pmd->details_root = le64_to_cpu(disk_super->device_details_root);751 752 __setup_btree_details(pmd);753 dm_bm_unlock(sblock);754 755 return 0;756 757bad_cleanup_data_sm:758 dm_sm_destroy(pmd->data_sm);759 pmd->data_sm = NULL;760bad_cleanup_tm:761 dm_tm_destroy(pmd->tm);762 pmd->tm = NULL;763 dm_sm_destroy(pmd->metadata_sm);764 pmd->metadata_sm = NULL;765bad_unlock_sblock:766 dm_bm_unlock(sblock);767 768 return r;769}770 771static int __open_or_format_metadata(struct dm_pool_metadata *pmd, bool format_device)772{773 int r, unformatted;774 775 r = __superblock_all_zeroes(pmd->bm, &unformatted);776 if (r)777 return r;778 779 if (unformatted)780 return format_device ? __format_metadata(pmd) : -EPERM;781 782 return __open_metadata(pmd);783}784 785static int __create_persistent_data_objects(struct dm_pool_metadata *pmd, bool format_device)786{787 int r;788 789 pmd->bm = dm_block_manager_create(pmd->bdev, THIN_METADATA_BLOCK_SIZE << SECTOR_SHIFT,790 THIN_MAX_CONCURRENT_LOCKS);791 if (IS_ERR(pmd->bm)) {792 DMERR("could not create block manager");793 r = PTR_ERR(pmd->bm);794 pmd->bm = NULL;795 return r;796 }797 798 r = __open_or_format_metadata(pmd, format_device);799 if (r) {800 dm_block_manager_destroy(pmd->bm);801 pmd->bm = NULL;802 }803 804 return r;805}806 807static void __destroy_persistent_data_objects(struct dm_pool_metadata *pmd,808 bool destroy_bm)809{810 dm_sm_destroy(pmd->data_sm);811 pmd->data_sm = NULL;812 dm_sm_destroy(pmd->metadata_sm);813 pmd->metadata_sm = NULL;814 dm_tm_destroy(pmd->nb_tm);815 pmd->nb_tm = NULL;816 dm_tm_destroy(pmd->tm);817 pmd->tm = NULL;818 if (destroy_bm)819 dm_block_manager_destroy(pmd->bm);820}821 822static int __begin_transaction(struct dm_pool_metadata *pmd)823{824 int r;825 struct thin_disk_superblock *disk_super;826 struct dm_block *sblock;827 828 /*829 * We re-read the superblock every time. Shouldn't need to do this830 * really.831 */832 r = dm_bm_read_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION,833 &sb_validator, &sblock);834 if (r)835 return r;836 837 disk_super = dm_block_data(sblock);838 pmd->time = le32_to_cpu(disk_super->time);839 pmd->root = le64_to_cpu(disk_super->data_mapping_root);840 pmd->details_root = le64_to_cpu(disk_super->device_details_root);841 pmd->trans_id = le64_to_cpu(disk_super->trans_id);842 pmd->flags = le32_to_cpu(disk_super->flags);843 pmd->data_block_size = le32_to_cpu(disk_super->data_block_size);844 845 dm_bm_unlock(sblock);846 return 0;847}848 849static int __write_changed_details(struct dm_pool_metadata *pmd)850{851 int r;852 struct dm_thin_device *td, *tmp;853 struct disk_device_details details;854 uint64_t key;855 856 list_for_each_entry_safe(td, tmp, &pmd->thin_devices, list) {857 if (!td->changed)858 continue;859 860 key = td->id;861 862 details.mapped_blocks = cpu_to_le64(td->mapped_blocks);863 details.transaction_id = cpu_to_le64(td->transaction_id);864 details.creation_time = cpu_to_le32(td->creation_time);865 details.snapshotted_time = cpu_to_le32(td->snapshotted_time);866 __dm_bless_for_disk(&details);867 868 r = dm_btree_insert(&pmd->details_info, pmd->details_root,869 &key, &details, &pmd->details_root);870 if (r)871 return r;872 873 if (td->open_count)874 td->changed = false;875 else {876 list_del(&td->list);877 kfree(td);878 }879 }880 881 return 0;882}883 884static int __commit_transaction(struct dm_pool_metadata *pmd)885{886 int r;887 struct thin_disk_superblock *disk_super;888 struct dm_block *sblock;889 890 /*891 * We need to know if the thin_disk_superblock exceeds a 512-byte sector.892 */893 BUILD_BUG_ON(sizeof(struct thin_disk_superblock) > 512);894 BUG_ON(!rwsem_is_locked(&pmd->root_lock));895 896 if (unlikely(!pmd->in_service))897 return 0;898 899 if (pmd->pre_commit_fn) {900 r = pmd->pre_commit_fn(pmd->pre_commit_context);901 if (r < 0) {902 DMERR("pre-commit callback failed");903 return r;904 }905 }906 907 r = __write_changed_details(pmd);908 if (r < 0)909 return r;910 911 r = dm_sm_commit(pmd->data_sm);912 if (r < 0)913 return r;914 915 r = dm_tm_pre_commit(pmd->tm);916 if (r < 0)917 return r;918 919 r = save_sm_roots(pmd);920 if (r < 0)921 return r;922 923 r = superblock_lock(pmd, &sblock);924 if (r)925 return r;926 927 disk_super = dm_block_data(sblock);928 disk_super->time = cpu_to_le32(pmd->time);929 disk_super->data_mapping_root = cpu_to_le64(pmd->root);930 disk_super->device_details_root = cpu_to_le64(pmd->details_root);931 disk_super->trans_id = cpu_to_le64(pmd->trans_id);932 disk_super->flags = cpu_to_le32(pmd->flags);933 934 copy_sm_roots(pmd, disk_super);935 936 return dm_tm_commit(pmd->tm, sblock);937}938 939static void __set_metadata_reserve(struct dm_pool_metadata *pmd)940{941 int r;942 dm_block_t total;943 dm_block_t max_blocks = 4096; /* 16M */944 945 r = dm_sm_get_nr_blocks(pmd->metadata_sm, &total);946 if (r) {947 DMERR("could not get size of metadata device");948 pmd->metadata_reserve = max_blocks;949 } else950 pmd->metadata_reserve = min(max_blocks, div_u64(total, 10));951}952 953struct dm_pool_metadata *dm_pool_metadata_open(struct block_device *bdev,954 sector_t data_block_size,955 bool format_device)956{957 int r;958 struct dm_pool_metadata *pmd;959 960 pmd = kmalloc(sizeof(*pmd), GFP_KERNEL);961 if (!pmd) {962 DMERR("could not allocate metadata struct");963 return ERR_PTR(-ENOMEM);964 }965 966 init_rwsem(&pmd->root_lock);967 pmd->time = 0;968 INIT_LIST_HEAD(&pmd->thin_devices);969 pmd->fail_io = false;970 pmd->in_service = false;971 pmd->bdev = bdev;972 pmd->data_block_size = data_block_size;973 pmd->pre_commit_fn = NULL;974 pmd->pre_commit_context = NULL;975 976 r = __create_persistent_data_objects(pmd, format_device);977 if (r) {978 kfree(pmd);979 return ERR_PTR(r);980 }981 982 r = __begin_transaction(pmd);983 if (r < 0) {984 if (dm_pool_metadata_close(pmd) < 0)985 DMWARN("%s: dm_pool_metadata_close() failed.", __func__);986 return ERR_PTR(r);987 }988 989 __set_metadata_reserve(pmd);990 991 return pmd;992}993 994int dm_pool_metadata_close(struct dm_pool_metadata *pmd)995{996 int r;997 unsigned int open_devices = 0;998 struct dm_thin_device *td, *tmp;999 1000 down_read(&pmd->root_lock);1001 list_for_each_entry_safe(td, tmp, &pmd->thin_devices, list) {1002 if (td->open_count)1003 open_devices++;1004 else {1005 list_del(&td->list);1006 kfree(td);1007 }1008 }1009 up_read(&pmd->root_lock);1010 1011 if (open_devices) {1012 DMERR("attempt to close pmd when %u device(s) are still open",1013 open_devices);1014 return -EBUSY;1015 }1016 1017 pmd_write_lock_in_core(pmd);1018 if (!pmd->fail_io && !dm_bm_is_read_only(pmd->bm)) {1019 r = __commit_transaction(pmd);1020 if (r < 0)1021 DMWARN("%s: __commit_transaction() failed, error = %d",1022 __func__, r);1023 }1024 pmd_write_unlock(pmd);1025 __destroy_persistent_data_objects(pmd, true);1026 1027 kfree(pmd);1028 return 0;1029}1030 1031/*1032 * __open_device: Returns @td corresponding to device with id @dev,1033 * creating it if @create is set and incrementing @td->open_count.1034 * On failure, @td is undefined.1035 */1036static int __open_device(struct dm_pool_metadata *pmd,1037 dm_thin_id dev, int create,1038 struct dm_thin_device **td)1039{1040 int r, changed = 0;1041 struct dm_thin_device *td2;1042 uint64_t key = dev;1043 struct disk_device_details details_le;1044 1045 /*1046 * If the device is already open, return it.1047 */1048 list_for_each_entry(td2, &pmd->thin_devices, list)1049 if (td2->id == dev) {1050 /*1051 * May not create an already-open device.1052 */1053 if (create)1054 return -EEXIST;1055 1056 td2->open_count++;1057 *td = td2;1058 return 0;1059 }1060 1061 /*1062 * Check the device exists.1063 */1064 r = dm_btree_lookup(&pmd->details_info, pmd->details_root,1065 &key, &details_le);1066 if (r) {1067 if (r != -ENODATA || !create)1068 return r;1069 1070 /*1071 * Create new device.1072 */1073 changed = 1;1074 details_le.mapped_blocks = 0;1075 details_le.transaction_id = cpu_to_le64(pmd->trans_id);1076 details_le.creation_time = cpu_to_le32(pmd->time);1077 details_le.snapshotted_time = cpu_to_le32(pmd->time);1078 }1079 1080 *td = kmalloc(sizeof(**td), GFP_NOIO);1081 if (!*td)1082 return -ENOMEM;1083 1084 (*td)->pmd = pmd;1085 (*td)->id = dev;1086 (*td)->open_count = 1;1087 (*td)->changed = changed;1088 (*td)->aborted_with_changes = false;1089 (*td)->mapped_blocks = le64_to_cpu(details_le.mapped_blocks);1090 (*td)->transaction_id = le64_to_cpu(details_le.transaction_id);1091 (*td)->creation_time = le32_to_cpu(details_le.creation_time);1092 (*td)->snapshotted_time = le32_to_cpu(details_le.snapshotted_time);1093 1094 list_add(&(*td)->list, &pmd->thin_devices);1095 1096 return 0;1097}1098 1099static void __close_device(struct dm_thin_device *td)1100{1101 --td->open_count;1102}1103 1104static int __create_thin(struct dm_pool_metadata *pmd,1105 dm_thin_id dev)1106{1107 int r;1108 dm_block_t dev_root;1109 uint64_t key = dev;1110 struct dm_thin_device *td;1111 __le64 value;1112 1113 r = dm_btree_lookup(&pmd->details_info, pmd->details_root,1114 &key, NULL);1115 if (!r)1116 return -EEXIST;1117 1118 /*1119 * Create an empty btree for the mappings.1120 */1121 r = dm_btree_empty(&pmd->bl_info, &dev_root);1122 if (r)1123 return r;1124 1125 /*1126 * Insert it into the main mapping tree.1127 */1128 value = cpu_to_le64(dev_root);1129 __dm_bless_for_disk(&value);1130 r = dm_btree_insert(&pmd->tl_info, pmd->root, &key, &value, &pmd->root);1131 if (r) {1132 dm_btree_del(&pmd->bl_info, dev_root);1133 return r;1134 }1135 1136 r = __open_device(pmd, dev, 1, &td);1137 if (r) {1138 dm_btree_remove(&pmd->tl_info, pmd->root, &key, &pmd->root);1139 dm_btree_del(&pmd->bl_info, dev_root);1140 return r;1141 }1142 __close_device(td);1143 1144 return r;1145}1146 1147int dm_pool_create_thin(struct dm_pool_metadata *pmd, dm_thin_id dev)1148{1149 int r = -EINVAL;1150 1151 pmd_write_lock(pmd);1152 if (!pmd->fail_io)1153 r = __create_thin(pmd, dev);1154 pmd_write_unlock(pmd);1155 1156 return r;1157}1158 1159static int __set_snapshot_details(struct dm_pool_metadata *pmd,1160 struct dm_thin_device *snap,1161 dm_thin_id origin, uint32_t time)1162{1163 int r;1164 struct dm_thin_device *td;1165 1166 r = __open_device(pmd, origin, 0, &td);1167 if (r)1168 return r;1169 1170 td->changed = true;1171 td->snapshotted_time = time;1172 1173 snap->mapped_blocks = td->mapped_blocks;1174 snap->snapshotted_time = time;1175 __close_device(td);1176 1177 return 0;1178}1179 1180static int __create_snap(struct dm_pool_metadata *pmd,1181 dm_thin_id dev, dm_thin_id origin)1182{1183 int r;1184 dm_block_t origin_root;1185 uint64_t key = origin, dev_key = dev;1186 struct dm_thin_device *td;1187 __le64 value;1188 1189 /* check this device is unused */1190 r = dm_btree_lookup(&pmd->details_info, pmd->details_root,1191 &dev_key, NULL);1192 if (!r)1193 return -EEXIST;1194 1195 /* find the mapping tree for the origin */1196 r = dm_btree_lookup(&pmd->tl_info, pmd->root, &key, &value);1197 if (r)1198 return r;1199 origin_root = le64_to_cpu(value);1200 1201 /* clone the origin, an inc will do */1202 dm_tm_inc(pmd->tm, origin_root);1203 1204 /* insert into the main mapping tree */1205 value = cpu_to_le64(origin_root);1206 __dm_bless_for_disk(&value);1207 key = dev;1208 r = dm_btree_insert(&pmd->tl_info, pmd->root, &key, &value, &pmd->root);1209 if (r) {1210 dm_tm_dec(pmd->tm, origin_root);1211 return r;1212 }1213 1214 pmd->time++;1215 1216 r = __open_device(pmd, dev, 1, &td);1217 if (r)1218 goto bad;1219 1220 r = __set_snapshot_details(pmd, td, origin, pmd->time);1221 __close_device(td);1222 1223 if (r)1224 goto bad;1225 1226 return 0;1227 1228bad:1229 dm_btree_remove(&pmd->tl_info, pmd->root, &key, &pmd->root);1230 dm_btree_remove(&pmd->details_info, pmd->details_root,1231 &key, &pmd->details_root);1232 return r;1233}1234 1235int dm_pool_create_snap(struct dm_pool_metadata *pmd,1236 dm_thin_id dev,1237 dm_thin_id origin)1238{1239 int r = -EINVAL;1240 1241 pmd_write_lock(pmd);1242 if (!pmd->fail_io)1243 r = __create_snap(pmd, dev, origin);1244 pmd_write_unlock(pmd);1245 1246 return r;1247}1248 1249static int __delete_device(struct dm_pool_metadata *pmd, dm_thin_id dev)1250{1251 int r;1252 uint64_t key = dev;1253 struct dm_thin_device *td;1254 1255 /* TODO: failure should mark the transaction invalid */1256 r = __open_device(pmd, dev, 0, &td);1257 if (r)1258 return r;1259 1260 if (td->open_count > 1) {1261 __close_device(td);1262 return -EBUSY;1263 }1264 1265 list_del(&td->list);1266 kfree(td);1267 r = dm_btree_remove(&pmd->details_info, pmd->details_root,1268 &key, &pmd->details_root);1269 if (r)1270 return r;1271 1272 r = dm_btree_remove(&pmd->tl_info, pmd->root, &key, &pmd->root);1273 if (r)1274 return r;1275 1276 return 0;1277}1278 1279int dm_pool_delete_thin_device(struct dm_pool_metadata *pmd,1280 dm_thin_id dev)1281{1282 int r = -EINVAL;1283 1284 pmd_write_lock(pmd);1285 if (!pmd->fail_io)1286 r = __delete_device(pmd, dev);1287 pmd_write_unlock(pmd);1288 1289 return r;1290}1291 1292int dm_pool_set_metadata_transaction_id(struct dm_pool_metadata *pmd,1293 uint64_t current_id,1294 uint64_t new_id)1295{1296 int r = -EINVAL;1297 1298 pmd_write_lock(pmd);1299 1300 if (pmd->fail_io)1301 goto out;1302 1303 if (pmd->trans_id != current_id) {1304 DMERR("mismatched transaction id");1305 goto out;1306 }1307 1308 pmd->trans_id = new_id;1309 r = 0;1310 1311out:1312 pmd_write_unlock(pmd);1313 1314 return r;1315}1316 1317int dm_pool_get_metadata_transaction_id(struct dm_pool_metadata *pmd,1318 uint64_t *result)1319{1320 int r = -EINVAL;1321 1322 down_read(&pmd->root_lock);1323 if (!pmd->fail_io) {1324 *result = pmd->trans_id;1325 r = 0;1326 }1327 up_read(&pmd->root_lock);1328 1329 return r;1330}1331 1332static int __reserve_metadata_snap(struct dm_pool_metadata *pmd)1333{1334 int r, inc;1335 struct thin_disk_superblock *disk_super;1336 struct dm_block *copy, *sblock;1337 dm_block_t held_root;1338 1339 /*1340 * We commit to ensure the btree roots which we increment in a1341 * moment are up to date.1342 */1343 r = __commit_transaction(pmd);1344 if (r < 0) {1345 DMWARN("%s: __commit_transaction() failed, error = %d",1346 __func__, r);1347 return r;1348 }1349 1350 /*1351 * Copy the superblock.1352 */1353 dm_sm_inc_block(pmd->metadata_sm, THIN_SUPERBLOCK_LOCATION);1354 r = dm_tm_shadow_block(pmd->tm, THIN_SUPERBLOCK_LOCATION,1355 &sb_validator, ©, &inc);1356 if (r)1357 return r;1358 1359 BUG_ON(!inc);1360 1361 held_root = dm_block_location(copy);1362 disk_super = dm_block_data(copy);1363 1364 if (le64_to_cpu(disk_super->held_root)) {1365 DMWARN("Pool metadata snapshot already exists: release this before taking another.");1366 1367 dm_tm_dec(pmd->tm, held_root);1368 dm_tm_unlock(pmd->tm, copy);1369 return -EBUSY;1370 }1371 1372 /*1373 * Wipe the spacemap since we're not publishing this.1374 */1375 memset(&disk_super->data_space_map_root, 0,1376 sizeof(disk_super->data_space_map_root));1377 memset(&disk_super->metadata_space_map_root, 0,1378 sizeof(disk_super->metadata_space_map_root));1379 1380 /*1381 * Increment the data structures that need to be preserved.1382 */1383 dm_tm_inc(pmd->tm, le64_to_cpu(disk_super->data_mapping_root));1384 dm_tm_inc(pmd->tm, le64_to_cpu(disk_super->device_details_root));1385 dm_tm_unlock(pmd->tm, copy);1386 1387 /*1388 * Write the held root into the superblock.1389 */1390 r = superblock_lock(pmd, &sblock);1391 if (r) {1392 dm_tm_dec(pmd->tm, held_root);1393 return r;1394 }1395 1396 disk_super = dm_block_data(sblock);1397 disk_super->held_root = cpu_to_le64(held_root);1398 dm_bm_unlock(sblock);1399 return 0;1400}1401 1402int dm_pool_reserve_metadata_snap(struct dm_pool_metadata *pmd)1403{1404 int r = -EINVAL;1405 1406 pmd_write_lock(pmd);1407 if (!pmd->fail_io)1408 r = __reserve_metadata_snap(pmd);1409 pmd_write_unlock(pmd);1410 1411 return r;1412}1413 1414static int __release_metadata_snap(struct dm_pool_metadata *pmd)1415{1416 int r;1417 struct thin_disk_superblock *disk_super;1418 struct dm_block *sblock, *copy;1419 dm_block_t held_root;1420 1421 r = superblock_lock(pmd, &sblock);1422 if (r)1423 return r;1424 1425 disk_super = dm_block_data(sblock);1426 held_root = le64_to_cpu(disk_super->held_root);1427 disk_super->held_root = cpu_to_le64(0);1428 1429 dm_bm_unlock(sblock);1430 1431 if (!held_root) {1432 DMWARN("No pool metadata snapshot found: nothing to release.");1433 return -EINVAL;1434 }1435 1436 r = dm_tm_read_lock(pmd->tm, held_root, &sb_validator, ©);1437 if (r)1438 return r;1439 1440 disk_super = dm_block_data(copy);1441 dm_btree_del(&pmd->info, le64_to_cpu(disk_super->data_mapping_root));1442 dm_btree_del(&pmd->details_info, le64_to_cpu(disk_super->device_details_root));1443 dm_sm_dec_block(pmd->metadata_sm, held_root);1444 1445 dm_tm_unlock(pmd->tm, copy);1446 1447 return 0;1448}1449 1450int dm_pool_release_metadata_snap(struct dm_pool_metadata *pmd)1451{1452 int r = -EINVAL;1453 1454 pmd_write_lock(pmd);1455 if (!pmd->fail_io)1456 r = __release_metadata_snap(pmd);1457 pmd_write_unlock(pmd);1458 1459 return r;1460}1461 1462static int __get_metadata_snap(struct dm_pool_metadata *pmd,1463 dm_block_t *result)1464{1465 int r;1466 struct thin_disk_superblock *disk_super;1467 struct dm_block *sblock;1468 1469 r = dm_bm_read_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION,1470 &sb_validator, &sblock);1471 if (r)1472 return r;1473 1474 disk_super = dm_block_data(sblock);1475 *result = le64_to_cpu(disk_super->held_root);1476 1477 dm_bm_unlock(sblock);1478 1479 return 0;1480}1481 1482int dm_pool_get_metadata_snap(struct dm_pool_metadata *pmd,1483 dm_block_t *result)1484{1485 int r = -EINVAL;1486 1487 down_read(&pmd->root_lock);1488 if (!pmd->fail_io)1489 r = __get_metadata_snap(pmd, result);1490 up_read(&pmd->root_lock);1491 1492 return r;1493}1494 1495int dm_pool_open_thin_device(struct dm_pool_metadata *pmd, dm_thin_id dev,1496 struct dm_thin_device **td)1497{1498 int r = -EINVAL;1499 1500 pmd_write_lock_in_core(pmd);1501 if (!pmd->fail_io)1502 r = __open_device(pmd, dev, 0, td);1503 pmd_write_unlock(pmd);1504 1505 return r;1506}1507 1508int dm_pool_close_thin_device(struct dm_thin_device *td)1509{1510 pmd_write_lock_in_core(td->pmd);1511 __close_device(td);1512 pmd_write_unlock(td->pmd);1513 1514 return 0;1515}1516 1517dm_thin_id dm_thin_dev_id(struct dm_thin_device *td)1518{1519 return td->id;1520}1521 1522/*1523 * Check whether @time (of block creation) is older than @td's last snapshot.1524 * If so then the associated block is shared with the last snapshot device.1525 * Any block on a device created *after* the device last got snapshotted is1526 * necessarily not shared.1527 */1528static bool __snapshotted_since(struct dm_thin_device *td, uint32_t time)1529{1530 return td->snapshotted_time > time;1531}1532 1533static void unpack_lookup_result(struct dm_thin_device *td, __le64 value,1534 struct dm_thin_lookup_result *result)1535{1536 uint64_t block_time = 0;1537 dm_block_t exception_block;1538 uint32_t exception_time;1539 1540 block_time = le64_to_cpu(value);1541 unpack_block_time(block_time, &exception_block, &exception_time);1542 result->block = exception_block;1543 result->shared = __snapshotted_since(td, exception_time);1544}1545 1546static int __find_block(struct dm_thin_device *td, dm_block_t block,1547 int can_issue_io, struct dm_thin_lookup_result *result)1548{1549 int r;1550 __le64 value;1551 struct dm_pool_metadata *pmd = td->pmd;1552 dm_block_t keys[2] = { td->id, block };1553 struct dm_btree_info *info;1554 1555 if (can_issue_io)1556 info = &pmd->info;1557 else1558 info = &pmd->nb_info;1559 1560 r = dm_btree_lookup(info, pmd->root, keys, &value);1561 if (!r)1562 unpack_lookup_result(td, value, result);1563 1564 return r;1565}1566 1567int dm_thin_find_block(struct dm_thin_device *td, dm_block_t block,1568 int can_issue_io, struct dm_thin_lookup_result *result)1569{1570 int r;1571 struct dm_pool_metadata *pmd = td->pmd;1572 1573 down_read(&pmd->root_lock);1574 if (pmd->fail_io) {1575 up_read(&pmd->root_lock);1576 return -EINVAL;1577 }1578 1579 r = __find_block(td, block, can_issue_io, result);1580 1581 up_read(&pmd->root_lock);1582 return r;1583}1584 1585static int __find_next_mapped_block(struct dm_thin_device *td, dm_block_t block,1586 dm_block_t *vblock,1587 struct dm_thin_lookup_result *result)1588{1589 int r;1590 __le64 value;1591 struct dm_pool_metadata *pmd = td->pmd;1592 dm_block_t keys[2] = { td->id, block };1593 1594 r = dm_btree_lookup_next(&pmd->info, pmd->root, keys, vblock, &value);1595 if (!r)1596 unpack_lookup_result(td, value, result);1597 1598 return r;1599}1600 1601static int __find_mapped_range(struct dm_thin_device *td,1602 dm_block_t begin, dm_block_t end,1603 dm_block_t *thin_begin, dm_block_t *thin_end,1604 dm_block_t *pool_begin, bool *maybe_shared)1605{1606 int r;1607 dm_block_t pool_end;1608 struct dm_thin_lookup_result lookup;1609 1610 if (end < begin)1611 return -ENODATA;1612 1613 r = __find_next_mapped_block(td, begin, &begin, &lookup);1614 if (r)1615 return r;1616 1617 if (begin >= end)1618 return -ENODATA;1619 1620 *thin_begin = begin;1621 *pool_begin = lookup.block;1622 *maybe_shared = lookup.shared;1623 1624 begin++;1625 pool_end = *pool_begin + 1;1626 while (begin != end) {1627 r = __find_block(td, begin, true, &lookup);1628 if (r) {1629 if (r == -ENODATA)1630 break;1631 1632 return r;1633 }1634 1635 if ((lookup.block != pool_end) ||1636 (lookup.shared != *maybe_shared))1637 break;1638 1639 pool_end++;1640 begin++;1641 }1642 1643 *thin_end = begin;1644 return 0;1645}1646 1647int dm_thin_find_mapped_range(struct dm_thin_device *td,1648 dm_block_t begin, dm_block_t end,1649 dm_block_t *thin_begin, dm_block_t *thin_end,1650 dm_block_t *pool_begin, bool *maybe_shared)1651{1652 int r = -EINVAL;1653 struct dm_pool_metadata *pmd = td->pmd;1654 1655 down_read(&pmd->root_lock);1656 if (!pmd->fail_io) {1657 r = __find_mapped_range(td, begin, end, thin_begin, thin_end,1658 pool_begin, maybe_shared);1659 }1660 up_read(&pmd->root_lock);1661 1662 return r;1663}1664 1665static int __insert(struct dm_thin_device *td, dm_block_t block,1666 dm_block_t data_block)1667{1668 int r, inserted;1669 __le64 value;1670 struct dm_pool_metadata *pmd = td->pmd;1671 dm_block_t keys[2] = { td->id, block };1672 1673 value = cpu_to_le64(pack_block_time(data_block, pmd->time));1674 __dm_bless_for_disk(&value);1675 1676 r = dm_btree_insert_notify(&pmd->info, pmd->root, keys, &value,1677 &pmd->root, &inserted);1678 if (r)1679 return r;1680 1681 td->changed = true;1682 if (inserted)1683 td->mapped_blocks++;1684 1685 return 0;1686}1687 1688int dm_thin_insert_block(struct dm_thin_device *td, dm_block_t block,1689 dm_block_t data_block)1690{1691 int r = -EINVAL;1692 1693 pmd_write_lock(td->pmd);1694 if (!td->pmd->fail_io)1695 r = __insert(td, block, data_block);1696 pmd_write_unlock(td->pmd);1697 1698 return r;1699}1700 1701static int __remove_range(struct dm_thin_device *td, dm_block_t begin, dm_block_t end)1702{1703 int r;1704 unsigned int count, total_count = 0;1705 struct dm_pool_metadata *pmd = td->pmd;1706 dm_block_t keys[1] = { td->id };1707 __le64 value;1708 dm_block_t mapping_root;1709 1710 /*1711 * Find the mapping tree1712 */1713 r = dm_btree_lookup(&pmd->tl_info, pmd->root, keys, &value);1714 if (r)1715 return r;1716 1717 /*1718 * Remove from the mapping tree, taking care to inc the1719 * ref count so it doesn't get deleted.1720 */1721 mapping_root = le64_to_cpu(value);1722 dm_tm_inc(pmd->tm, mapping_root);1723 r = dm_btree_remove(&pmd->tl_info, pmd->root, keys, &pmd->root);1724 if (r)1725 return r;1726 1727 /*1728 * Remove leaves stops at the first unmapped entry, so we have to1729 * loop round finding mapped ranges.1730 */1731 while (begin < end) {1732 r = dm_btree_lookup_next(&pmd->bl_info, mapping_root, &begin, &begin, &value);1733 if (r == -ENODATA)1734 break;1735 1736 if (r)1737 return r;1738 1739 if (begin >= end)1740 break;1741 1742 r = dm_btree_remove_leaves(&pmd->bl_info, mapping_root, &begin, end, &mapping_root, &count);1743 if (r)1744 return r;1745 1746 total_count += count;1747 }1748 1749 td->mapped_blocks -= total_count;1750 td->changed = true;1751 1752 /*1753 * Reinsert the mapping tree.1754 */1755 value = cpu_to_le64(mapping_root);1756 __dm_bless_for_disk(&value);1757 return dm_btree_insert(&pmd->tl_info, pmd->root, keys, &value, &pmd->root);1758}1759 1760int dm_thin_remove_range(struct dm_thin_device *td,1761 dm_block_t begin, dm_block_t end)1762{1763 int r = -EINVAL;1764 1765 pmd_write_lock(td->pmd);1766 if (!td->pmd->fail_io)1767 r = __remove_range(td, begin, end);1768 pmd_write_unlock(td->pmd);1769 1770 return r;1771}1772 1773int dm_pool_block_is_shared(struct dm_pool_metadata *pmd, dm_block_t b, bool *result)1774{1775 int r = -EINVAL;1776 uint32_t ref_count;1777 1778 down_read(&pmd->root_lock);1779 if (!pmd->fail_io) {1780 r = dm_sm_get_count(pmd->data_sm, b, &ref_count);1781 if (!r)1782 *result = (ref_count > 1);1783 }1784 up_read(&pmd->root_lock);1785 1786 return r;1787}1788 1789int dm_pool_inc_data_range(struct dm_pool_metadata *pmd, dm_block_t b, dm_block_t e)1790{1791 int r = -EINVAL;1792 1793 pmd_write_lock(pmd);1794 if (!pmd->fail_io)1795 r = dm_sm_inc_blocks(pmd->data_sm, b, e);1796 pmd_write_unlock(pmd);1797 1798 return r;1799}1800 1801int dm_pool_dec_data_range(struct dm_pool_metadata *pmd, dm_block_t b, dm_block_t e)1802{1803 int r = -EINVAL;1804 1805 pmd_write_lock(pmd);1806 if (!pmd->fail_io)1807 r = dm_sm_dec_blocks(pmd->data_sm, b, e);1808 pmd_write_unlock(pmd);1809 1810 return r;1811}1812 1813bool dm_thin_changed_this_transaction(struct dm_thin_device *td)1814{1815 int r;1816 1817 down_read(&td->pmd->root_lock);1818 r = td->changed;1819 up_read(&td->pmd->root_lock);1820 1821 return r;1822}1823 1824bool dm_pool_changed_this_transaction(struct dm_pool_metadata *pmd)1825{1826 bool r = false;1827 struct dm_thin_device *td, *tmp;1828 1829 down_read(&pmd->root_lock);1830 list_for_each_entry_safe(td, tmp, &pmd->thin_devices, list) {1831 if (td->changed) {1832 r = td->changed;1833 break;1834 }1835 }1836 up_read(&pmd->root_lock);1837 1838 return r;1839}1840 1841bool dm_thin_aborted_changes(struct dm_thin_device *td)1842{1843 bool r;1844 1845 down_read(&td->pmd->root_lock);1846 r = td->aborted_with_changes;1847 up_read(&td->pmd->root_lock);1848 1849 return r;1850}1851 1852int dm_pool_alloc_data_block(struct dm_pool_metadata *pmd, dm_block_t *result)1853{1854 int r = -EINVAL;1855 1856 pmd_write_lock(pmd);1857 if (!pmd->fail_io)1858 r = dm_sm_new_block(pmd->data_sm, result);1859 pmd_write_unlock(pmd);1860 1861 return r;1862}1863 1864int dm_pool_commit_metadata(struct dm_pool_metadata *pmd)1865{1866 int r = -EINVAL;1867 1868 /*1869 * Care is taken to not have commit be what1870 * triggers putting the thin-pool in-service.1871 */1872 pmd_write_lock_in_core(pmd);1873 if (pmd->fail_io)1874 goto out;1875 1876 r = __commit_transaction(pmd);1877 if (r < 0)1878 goto out;1879 1880 /*1881 * Open the next transaction.1882 */1883 r = __begin_transaction(pmd);1884out:1885 pmd_write_unlock(pmd);1886 return r;1887}1888 1889static void __set_abort_with_changes_flags(struct dm_pool_metadata *pmd)1890{1891 struct dm_thin_device *td;1892 1893 list_for_each_entry(td, &pmd->thin_devices, list)1894 td->aborted_with_changes = td->changed;1895}1896 1897int dm_pool_abort_metadata(struct dm_pool_metadata *pmd)1898{1899 int r = -EINVAL;1900 1901 /* fail_io is double-checked with pmd->root_lock held below */1902 if (unlikely(pmd->fail_io))1903 return r;1904 1905 pmd_write_lock(pmd);1906 if (pmd->fail_io) {1907 pmd_write_unlock(pmd);1908 return r;1909 }1910 __set_abort_with_changes_flags(pmd);1911 1912 /* destroy data_sm/metadata_sm/nb_tm/tm */1913 __destroy_persistent_data_objects(pmd, false);1914 1915 /* reset bm */1916 dm_block_manager_reset(pmd->bm);1917 1918 /* rebuild data_sm/metadata_sm/nb_tm/tm */1919 r = __open_or_format_metadata(pmd, false);1920 if (r)1921 pmd->fail_io = true;1922 pmd_write_unlock(pmd);1923 return r;1924}1925 1926int dm_pool_get_free_block_count(struct dm_pool_metadata *pmd, dm_block_t *result)1927{1928 int r = -EINVAL;1929 1930 down_read(&pmd->root_lock);1931 if (!pmd->fail_io)1932 r = dm_sm_get_nr_free(pmd->data_sm, result);1933 up_read(&pmd->root_lock);1934 1935 return r;1936}1937 1938int dm_pool_get_free_metadata_block_count(struct dm_pool_metadata *pmd,1939 dm_block_t *result)1940{1941 int r = -EINVAL;1942 1943 down_read(&pmd->root_lock);1944 if (!pmd->fail_io)1945 r = dm_sm_get_nr_free(pmd->metadata_sm, result);1946 1947 if (!r) {1948 if (*result < pmd->metadata_reserve)1949 *result = 0;1950 else1951 *result -= pmd->metadata_reserve;1952 }1953 up_read(&pmd->root_lock);1954 1955 return r;1956}1957 1958int dm_pool_get_metadata_dev_size(struct dm_pool_metadata *pmd,1959 dm_block_t *result)1960{1961 int r = -EINVAL;1962 1963 down_read(&pmd->root_lock);1964 if (!pmd->fail_io)1965 r = dm_sm_get_nr_blocks(pmd->metadata_sm, result);1966 up_read(&pmd->root_lock);1967 1968 return r;1969}1970 1971int dm_pool_get_data_dev_size(struct dm_pool_metadata *pmd, dm_block_t *result)1972{1973 int r = -EINVAL;1974 1975 down_read(&pmd->root_lock);1976 if (!pmd->fail_io)1977 r = dm_sm_get_nr_blocks(pmd->data_sm, result);1978 up_read(&pmd->root_lock);1979 1980 return r;1981}1982 1983int dm_thin_get_mapped_count(struct dm_thin_device *td, dm_block_t *result)1984{1985 int r = -EINVAL;1986 struct dm_pool_metadata *pmd = td->pmd;1987 1988 down_read(&pmd->root_lock);1989 if (!pmd->fail_io) {1990 *result = td->mapped_blocks;1991 r = 0;1992 }1993 up_read(&pmd->root_lock);1994 1995 return r;1996}1997 1998static int __highest_block(struct dm_thin_device *td, dm_block_t *result)1999{2000 int r;2001 __le64 value_le;2002 dm_block_t thin_root;2003 struct dm_pool_metadata *pmd = td->pmd;2004 2005 r = dm_btree_lookup(&pmd->tl_info, pmd->root, &td->id, &value_le);2006 if (r)2007 return r;2008 2009 thin_root = le64_to_cpu(value_le);2010 2011 return dm_btree_find_highest_key(&pmd->bl_info, thin_root, result);2012}2013 2014int dm_thin_get_highest_mapped_block(struct dm_thin_device *td,2015 dm_block_t *result)2016{2017 int r = -EINVAL;2018 struct dm_pool_metadata *pmd = td->pmd;2019 2020 down_read(&pmd->root_lock);2021 if (!pmd->fail_io)2022 r = __highest_block(td, result);2023 up_read(&pmd->root_lock);2024 2025 return r;2026}2027 2028static int __resize_space_map(struct dm_space_map *sm, dm_block_t new_count)2029{2030 int r;2031 dm_block_t old_count;2032 2033 r = dm_sm_get_nr_blocks(sm, &old_count);2034 if (r)2035 return r;2036 2037 if (new_count == old_count)2038 return 0;2039 2040 if (new_count < old_count) {2041 DMERR("cannot reduce size of space map");2042 return -EINVAL;2043 }2044 2045 return dm_sm_extend(sm, new_count - old_count);2046}2047 2048int dm_pool_resize_data_dev(struct dm_pool_metadata *pmd, dm_block_t new_count)2049{2050 int r = -EINVAL;2051 2052 pmd_write_lock(pmd);2053 if (!pmd->fail_io)2054 r = __resize_space_map(pmd->data_sm, new_count);2055 pmd_write_unlock(pmd);2056 2057 return r;2058}2059 2060int dm_pool_resize_metadata_dev(struct dm_pool_metadata *pmd, dm_block_t new_count)2061{2062 int r = -EINVAL;2063 2064 pmd_write_lock(pmd);2065 if (!pmd->fail_io) {2066 r = __resize_space_map(pmd->metadata_sm, new_count);2067 if (!r)2068 __set_metadata_reserve(pmd);2069 }2070 pmd_write_unlock(pmd);2071 2072 return r;2073}2074 2075void dm_pool_metadata_read_only(struct dm_pool_metadata *pmd)2076{2077 pmd_write_lock_in_core(pmd);2078 dm_bm_set_read_only(pmd->bm);2079 pmd_write_unlock(pmd);2080}2081 2082void dm_pool_metadata_read_write(struct dm_pool_metadata *pmd)2083{2084 pmd_write_lock_in_core(pmd);2085 dm_bm_set_read_write(pmd->bm);2086 pmd_write_unlock(pmd);2087}2088 2089int dm_pool_register_metadata_threshold(struct dm_pool_metadata *pmd,2090 dm_block_t threshold,2091 dm_sm_threshold_fn fn,2092 void *context)2093{2094 int r = -EINVAL;2095 2096 pmd_write_lock_in_core(pmd);2097 if (!pmd->fail_io) {2098 r = dm_sm_register_threshold_callback(pmd->metadata_sm,2099 threshold, fn, context);2100 }2101 pmd_write_unlock(pmd);2102 2103 return r;2104}2105 2106void dm_pool_register_pre_commit_callback(struct dm_pool_metadata *pmd,2107 dm_pool_pre_commit_fn fn,2108 void *context)2109{2110 pmd_write_lock_in_core(pmd);2111 pmd->pre_commit_fn = fn;2112 pmd->pre_commit_context = context;2113 pmd_write_unlock(pmd);2114}2115 2116int dm_pool_metadata_set_needs_check(struct dm_pool_metadata *pmd)2117{2118 int r = -EINVAL;2119 struct dm_block *sblock;2120 struct thin_disk_superblock *disk_super;2121 2122 pmd_write_lock(pmd);2123 if (pmd->fail_io)2124 goto out;2125 2126 pmd->flags |= THIN_METADATA_NEEDS_CHECK_FLAG;2127 2128 r = superblock_lock(pmd, &sblock);2129 if (r) {2130 DMERR("couldn't lock superblock");2131 goto out;2132 }2133 2134 disk_super = dm_block_data(sblock);2135 disk_super->flags = cpu_to_le32(pmd->flags);2136 2137 dm_bm_unlock(sblock);2138out:2139 pmd_write_unlock(pmd);2140 return r;2141}2142 2143bool dm_pool_metadata_needs_check(struct dm_pool_metadata *pmd)2144{2145 bool needs_check;2146 2147 down_read(&pmd->root_lock);2148 needs_check = pmd->flags & THIN_METADATA_NEEDS_CHECK_FLAG;2149 up_read(&pmd->root_lock);2150 2151 return needs_check;2152}2153 2154void dm_pool_issue_prefetches(struct dm_pool_metadata *pmd)2155{2156 down_read(&pmd->root_lock);2157 if (!pmd->fail_io)2158 dm_tm_issue_prefetches(pmd->tm);2159 up_read(&pmd->root_lock);2160}2161