v4.19.13 snapshot.
diff --git a/drivers/md/dm-thin-metadata.c b/drivers/md/dm-thin-metadata.c
new file mode 100644
index 0000000..20b0776
--- /dev/null
+++ b/drivers/md/dm-thin-metadata.c
@@ -0,0 +1,2043 @@
+/*
+ * Copyright (C) 2011-2012 Red Hat, Inc.
+ *
+ * This file is released under the GPL.
+ */
+
+#include "dm-thin-metadata.h"
+#include "persistent-data/dm-btree.h"
+#include "persistent-data/dm-space-map.h"
+#include "persistent-data/dm-space-map-disk.h"
+#include "persistent-data/dm-transaction-manager.h"
+
+#include <linux/list.h>
+#include <linux/device-mapper.h>
+#include <linux/workqueue.h>
+
+/*--------------------------------------------------------------------------
+ * As far as the metadata goes, there is:
+ *
+ * - A superblock in block zero, taking up fewer than 512 bytes for
+ * atomic writes.
+ *
+ * - A space map managing the metadata blocks.
+ *
+ * - A space map managing the data blocks.
+ *
+ * - A btree mapping our internal thin dev ids onto struct disk_device_details.
+ *
+ * - A hierarchical btree, with 2 levels which effectively maps (thin
+ * dev id, virtual block) -> block_time. Block time is a 64-bit
+ * field holding the time in the low 24 bits, and block in the top 48
+ * bits.
+ *
+ * BTrees consist solely of btree_nodes, that fill a block. Some are
+ * internal nodes, as such their values are a __le64 pointing to other
+ * nodes. Leaf nodes can store data of any reasonable size (ie. much
+ * smaller than the block size). The nodes consist of the header,
+ * followed by an array of keys, followed by an array of values. We have
+ * to binary search on the keys so they're all held together to help the
+ * cpu cache.
+ *
+ * Space maps have 2 btrees:
+ *
+ * - One maps a uint64_t onto a struct index_entry. Which points to a
+ * bitmap block, and has some details about how many free entries there
+ * are etc.
+ *
+ * - The bitmap blocks have a header (for the checksum). Then the rest
+ * of the block is pairs of bits. With the meaning being:
+ *
+ * 0 - ref count is 0
+ * 1 - ref count is 1
+ * 2 - ref count is 2
+ * 3 - ref count is higher than 2
+ *
+ * - If the count is higher than 2 then the ref count is entered in a
+ * second btree that directly maps the block_address to a uint32_t ref
+ * count.
+ *
+ * The space map metadata variant doesn't have a bitmaps btree. Instead
+ * it has one single blocks worth of index_entries. This avoids
+ * recursive issues with the bitmap btree needing to allocate space in
+ * order to insert. With a small data block size such as 64k the
+ * metadata support data devices that are hundreds of terrabytes.
+ *
+ * The space maps allocate space linearly from front to back. Space that
+ * is freed in a transaction is never recycled within that transaction.
+ * To try and avoid fragmenting _free_ space the allocator always goes
+ * back and fills in gaps.
+ *
+ * All metadata io is in THIN_METADATA_BLOCK_SIZE sized/aligned chunks
+ * from the block manager.
+ *--------------------------------------------------------------------------*/
+
+#define DM_MSG_PREFIX "thin metadata"
+
+#define THIN_SUPERBLOCK_MAGIC 27022010
+#define THIN_SUPERBLOCK_LOCATION 0
+#define THIN_VERSION 2
+#define SECTOR_TO_BLOCK_SHIFT 3
+
+/*
+ * For btree insert:
+ * 3 for btree insert +
+ * 2 for btree lookup used within space map
+ * For btree remove:
+ * 2 for shadow spine +
+ * 4 for rebalance 3 child node
+ */
+#define THIN_MAX_CONCURRENT_LOCKS 6
+
+/* This should be plenty */
+#define SPACE_MAP_ROOT_SIZE 128
+
+/*
+ * Little endian on-disk superblock and device details.
+ */
+struct thin_disk_superblock {
+ __le32 csum; /* Checksum of superblock except for this field. */
+ __le32 flags;
+ __le64 blocknr; /* This block number, dm_block_t. */
+
+ __u8 uuid[16];
+ __le64 magic;
+ __le32 version;
+ __le32 time;
+
+ __le64 trans_id;
+
+ /*
+ * Root held by userspace transactions.
+ */
+ __le64 held_root;
+
+ __u8 data_space_map_root[SPACE_MAP_ROOT_SIZE];
+ __u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE];
+
+ /*
+ * 2-level btree mapping (dev_id, (dev block, time)) -> data block
+ */
+ __le64 data_mapping_root;
+
+ /*
+ * Device detail root mapping dev_id -> device_details
+ */
+ __le64 device_details_root;
+
+ __le32 data_block_size; /* In 512-byte sectors. */
+
+ __le32 metadata_block_size; /* In 512-byte sectors. */
+ __le64 metadata_nr_blocks;
+
+ __le32 compat_flags;
+ __le32 compat_ro_flags;
+ __le32 incompat_flags;
+} __packed;
+
+struct disk_device_details {
+ __le64 mapped_blocks;
+ __le64 transaction_id; /* When created. */
+ __le32 creation_time;
+ __le32 snapshotted_time;
+} __packed;
+
+struct dm_pool_metadata {
+ struct hlist_node hash;
+
+ struct block_device *bdev;
+ struct dm_block_manager *bm;
+ struct dm_space_map *metadata_sm;
+ struct dm_space_map *data_sm;
+ struct dm_transaction_manager *tm;
+ struct dm_transaction_manager *nb_tm;
+
+ /*
+ * Two-level btree.
+ * First level holds thin_dev_t.
+ * Second level holds mappings.
+ */
+ struct dm_btree_info info;
+
+ /*
+ * Non-blocking version of the above.
+ */
+ struct dm_btree_info nb_info;
+
+ /*
+ * Just the top level for deleting whole devices.
+ */
+ struct dm_btree_info tl_info;
+
+ /*
+ * Just the bottom level for creating new devices.
+ */
+ struct dm_btree_info bl_info;
+
+ /*
+ * Describes the device details btree.
+ */
+ struct dm_btree_info details_info;
+
+ struct rw_semaphore root_lock;
+ uint32_t time;
+ dm_block_t root;
+ dm_block_t details_root;
+ struct list_head thin_devices;
+ uint64_t trans_id;
+ unsigned long flags;
+ sector_t data_block_size;
+
+ /*
+ * We reserve a section of the metadata for commit overhead.
+ * All reported space does *not* include this.
+ */
+ dm_block_t metadata_reserve;
+
+ /*
+ * Set if a transaction has to be aborted but the attempt to roll back
+ * to the previous (good) transaction failed. The only pool metadata
+ * operation possible in this state is the closing of the device.
+ */
+ bool fail_io:1;
+
+ /*
+ * Reading the space map roots can fail, so we read it into these
+ * buffers before the superblock is locked and updated.
+ */
+ __u8 data_space_map_root[SPACE_MAP_ROOT_SIZE];
+ __u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE];
+};
+
+struct dm_thin_device {
+ struct list_head list;
+ struct dm_pool_metadata *pmd;
+ dm_thin_id id;
+
+ int open_count;
+ bool changed:1;
+ bool aborted_with_changes:1;
+ uint64_t mapped_blocks;
+ uint64_t transaction_id;
+ uint32_t creation_time;
+ uint32_t snapshotted_time;
+};
+
+/*----------------------------------------------------------------
+ * superblock validator
+ *--------------------------------------------------------------*/
+
+#define SUPERBLOCK_CSUM_XOR 160774
+
+static void sb_prepare_for_write(struct dm_block_validator *v,
+ struct dm_block *b,
+ size_t block_size)
+{
+ struct thin_disk_superblock *disk_super = dm_block_data(b);
+
+ disk_super->blocknr = cpu_to_le64(dm_block_location(b));
+ disk_super->csum = cpu_to_le32(dm_bm_checksum(&disk_super->flags,
+ block_size - sizeof(__le32),
+ SUPERBLOCK_CSUM_XOR));
+}
+
+static int sb_check(struct dm_block_validator *v,
+ struct dm_block *b,
+ size_t block_size)
+{
+ struct thin_disk_superblock *disk_super = dm_block_data(b);
+ __le32 csum_le;
+
+ if (dm_block_location(b) != le64_to_cpu(disk_super->blocknr)) {
+ DMERR("sb_check failed: blocknr %llu: "
+ "wanted %llu", le64_to_cpu(disk_super->blocknr),
+ (unsigned long long)dm_block_location(b));
+ return -ENOTBLK;
+ }
+
+ if (le64_to_cpu(disk_super->magic) != THIN_SUPERBLOCK_MAGIC) {
+ DMERR("sb_check failed: magic %llu: "
+ "wanted %llu", le64_to_cpu(disk_super->magic),
+ (unsigned long long)THIN_SUPERBLOCK_MAGIC);
+ return -EILSEQ;
+ }
+
+ csum_le = cpu_to_le32(dm_bm_checksum(&disk_super->flags,
+ block_size - sizeof(__le32),
+ SUPERBLOCK_CSUM_XOR));
+ if (csum_le != disk_super->csum) {
+ DMERR("sb_check failed: csum %u: wanted %u",
+ le32_to_cpu(csum_le), le32_to_cpu(disk_super->csum));
+ return -EILSEQ;
+ }
+
+ return 0;
+}
+
+static struct dm_block_validator sb_validator = {
+ .name = "superblock",
+ .prepare_for_write = sb_prepare_for_write,
+ .check = sb_check
+};
+
+/*----------------------------------------------------------------
+ * Methods for the btree value types
+ *--------------------------------------------------------------*/
+
+static uint64_t pack_block_time(dm_block_t b, uint32_t t)
+{
+ return (b << 24) | t;
+}
+
+static void unpack_block_time(uint64_t v, dm_block_t *b, uint32_t *t)
+{
+ *b = v >> 24;
+ *t = v & ((1 << 24) - 1);
+}
+
+static void data_block_inc(void *context, const void *value_le)
+{
+ struct dm_space_map *sm = context;
+ __le64 v_le;
+ uint64_t b;
+ uint32_t t;
+
+ memcpy(&v_le, value_le, sizeof(v_le));
+ unpack_block_time(le64_to_cpu(v_le), &b, &t);
+ dm_sm_inc_block(sm, b);
+}
+
+static void data_block_dec(void *context, const void *value_le)
+{
+ struct dm_space_map *sm = context;
+ __le64 v_le;
+ uint64_t b;
+ uint32_t t;
+
+ memcpy(&v_le, value_le, sizeof(v_le));
+ unpack_block_time(le64_to_cpu(v_le), &b, &t);
+ dm_sm_dec_block(sm, b);
+}
+
+static int data_block_equal(void *context, const void *value1_le, const void *value2_le)
+{
+ __le64 v1_le, v2_le;
+ uint64_t b1, b2;
+ uint32_t t;
+
+ memcpy(&v1_le, value1_le, sizeof(v1_le));
+ memcpy(&v2_le, value2_le, sizeof(v2_le));
+ unpack_block_time(le64_to_cpu(v1_le), &b1, &t);
+ unpack_block_time(le64_to_cpu(v2_le), &b2, &t);
+
+ return b1 == b2;
+}
+
+static void subtree_inc(void *context, const void *value)
+{
+ struct dm_btree_info *info = context;
+ __le64 root_le;
+ uint64_t root;
+
+ memcpy(&root_le, value, sizeof(root_le));
+ root = le64_to_cpu(root_le);
+ dm_tm_inc(info->tm, root);
+}
+
+static void subtree_dec(void *context, const void *value)
+{
+ struct dm_btree_info *info = context;
+ __le64 root_le;
+ uint64_t root;
+
+ memcpy(&root_le, value, sizeof(root_le));
+ root = le64_to_cpu(root_le);
+ if (dm_btree_del(info, root))
+ DMERR("btree delete failed");
+}
+
+static int subtree_equal(void *context, const void *value1_le, const void *value2_le)
+{
+ __le64 v1_le, v2_le;
+ memcpy(&v1_le, value1_le, sizeof(v1_le));
+ memcpy(&v2_le, value2_le, sizeof(v2_le));
+
+ return v1_le == v2_le;
+}
+
+/*----------------------------------------------------------------*/
+
+static int superblock_lock_zero(struct dm_pool_metadata *pmd,
+ struct dm_block **sblock)
+{
+ return dm_bm_write_lock_zero(pmd->bm, THIN_SUPERBLOCK_LOCATION,
+ &sb_validator, sblock);
+}
+
+static int superblock_lock(struct dm_pool_metadata *pmd,
+ struct dm_block **sblock)
+{
+ return dm_bm_write_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION,
+ &sb_validator, sblock);
+}
+
+static int __superblock_all_zeroes(struct dm_block_manager *bm, int *result)
+{
+ int r;
+ unsigned i;
+ struct dm_block *b;
+ __le64 *data_le, zero = cpu_to_le64(0);
+ unsigned block_size = dm_bm_block_size(bm) / sizeof(__le64);
+
+ /*
+ * We can't use a validator here - it may be all zeroes.
+ */
+ r = dm_bm_read_lock(bm, THIN_SUPERBLOCK_LOCATION, NULL, &b);
+ if (r)
+ return r;
+
+ data_le = dm_block_data(b);
+ *result = 1;
+ for (i = 0; i < block_size; i++) {
+ if (data_le[i] != zero) {
+ *result = 0;
+ break;
+ }
+ }
+
+ dm_bm_unlock(b);
+
+ return 0;
+}
+
+static void __setup_btree_details(struct dm_pool_metadata *pmd)
+{
+ pmd->info.tm = pmd->tm;
+ pmd->info.levels = 2;
+ pmd->info.value_type.context = pmd->data_sm;
+ pmd->info.value_type.size = sizeof(__le64);
+ pmd->info.value_type.inc = data_block_inc;
+ pmd->info.value_type.dec = data_block_dec;
+ pmd->info.value_type.equal = data_block_equal;
+
+ memcpy(&pmd->nb_info, &pmd->info, sizeof(pmd->nb_info));
+ pmd->nb_info.tm = pmd->nb_tm;
+
+ pmd->tl_info.tm = pmd->tm;
+ pmd->tl_info.levels = 1;
+ pmd->tl_info.value_type.context = &pmd->bl_info;
+ pmd->tl_info.value_type.size = sizeof(__le64);
+ pmd->tl_info.value_type.inc = subtree_inc;
+ pmd->tl_info.value_type.dec = subtree_dec;
+ pmd->tl_info.value_type.equal = subtree_equal;
+
+ pmd->bl_info.tm = pmd->tm;
+ pmd->bl_info.levels = 1;
+ pmd->bl_info.value_type.context = pmd->data_sm;
+ pmd->bl_info.value_type.size = sizeof(__le64);
+ pmd->bl_info.value_type.inc = data_block_inc;
+ pmd->bl_info.value_type.dec = data_block_dec;
+ pmd->bl_info.value_type.equal = data_block_equal;
+
+ pmd->details_info.tm = pmd->tm;
+ pmd->details_info.levels = 1;
+ pmd->details_info.value_type.context = NULL;
+ pmd->details_info.value_type.size = sizeof(struct disk_device_details);
+ pmd->details_info.value_type.inc = NULL;
+ pmd->details_info.value_type.dec = NULL;
+ pmd->details_info.value_type.equal = NULL;
+}
+
+static int save_sm_roots(struct dm_pool_metadata *pmd)
+{
+ int r;
+ size_t len;
+
+ r = dm_sm_root_size(pmd->metadata_sm, &len);
+ if (r < 0)
+ return r;
+
+ r = dm_sm_copy_root(pmd->metadata_sm, &pmd->metadata_space_map_root, len);
+ if (r < 0)
+ return r;
+
+ r = dm_sm_root_size(pmd->data_sm, &len);
+ if (r < 0)
+ return r;
+
+ return dm_sm_copy_root(pmd->data_sm, &pmd->data_space_map_root, len);
+}
+
+static void copy_sm_roots(struct dm_pool_metadata *pmd,
+ struct thin_disk_superblock *disk)
+{
+ memcpy(&disk->metadata_space_map_root,
+ &pmd->metadata_space_map_root,
+ sizeof(pmd->metadata_space_map_root));
+
+ memcpy(&disk->data_space_map_root,
+ &pmd->data_space_map_root,
+ sizeof(pmd->data_space_map_root));
+}
+
+static int __write_initial_superblock(struct dm_pool_metadata *pmd)
+{
+ int r;
+ struct dm_block *sblock;
+ struct thin_disk_superblock *disk_super;
+ sector_t bdev_size = i_size_read(pmd->bdev->bd_inode) >> SECTOR_SHIFT;
+
+ if (bdev_size > THIN_METADATA_MAX_SECTORS)
+ bdev_size = THIN_METADATA_MAX_SECTORS;
+
+ r = dm_sm_commit(pmd->data_sm);
+ if (r < 0)
+ return r;
+
+ r = dm_tm_pre_commit(pmd->tm);
+ if (r < 0)
+ return r;
+
+ r = save_sm_roots(pmd);
+ if (r < 0)
+ return r;
+
+ r = superblock_lock_zero(pmd, &sblock);
+ if (r)
+ return r;
+
+ disk_super = dm_block_data(sblock);
+ disk_super->flags = 0;
+ memset(disk_super->uuid, 0, sizeof(disk_super->uuid));
+ disk_super->magic = cpu_to_le64(THIN_SUPERBLOCK_MAGIC);
+ disk_super->version = cpu_to_le32(THIN_VERSION);
+ disk_super->time = 0;
+ disk_super->trans_id = 0;
+ disk_super->held_root = 0;
+
+ copy_sm_roots(pmd, disk_super);
+
+ disk_super->data_mapping_root = cpu_to_le64(pmd->root);
+ disk_super->device_details_root = cpu_to_le64(pmd->details_root);
+ disk_super->metadata_block_size = cpu_to_le32(THIN_METADATA_BLOCK_SIZE);
+ disk_super->metadata_nr_blocks = cpu_to_le64(bdev_size >> SECTOR_TO_BLOCK_SHIFT);
+ disk_super->data_block_size = cpu_to_le32(pmd->data_block_size);
+
+ return dm_tm_commit(pmd->tm, sblock);
+}
+
+static int __format_metadata(struct dm_pool_metadata *pmd)
+{
+ int r;
+
+ r = dm_tm_create_with_sm(pmd->bm, THIN_SUPERBLOCK_LOCATION,
+ &pmd->tm, &pmd->metadata_sm);
+ if (r < 0) {
+ DMERR("tm_create_with_sm failed");
+ return r;
+ }
+
+ pmd->data_sm = dm_sm_disk_create(pmd->tm, 0);
+ if (IS_ERR(pmd->data_sm)) {
+ DMERR("sm_disk_create failed");
+ r = PTR_ERR(pmd->data_sm);
+ goto bad_cleanup_tm;
+ }
+
+ pmd->nb_tm = dm_tm_create_non_blocking_clone(pmd->tm);
+ if (!pmd->nb_tm) {
+ DMERR("could not create non-blocking clone tm");
+ r = -ENOMEM;
+ goto bad_cleanup_data_sm;
+ }
+
+ __setup_btree_details(pmd);
+
+ r = dm_btree_empty(&pmd->info, &pmd->root);
+ if (r < 0)
+ goto bad_cleanup_nb_tm;
+
+ r = dm_btree_empty(&pmd->details_info, &pmd->details_root);
+ if (r < 0) {
+ DMERR("couldn't create devices root");
+ goto bad_cleanup_nb_tm;
+ }
+
+ r = __write_initial_superblock(pmd);
+ if (r)
+ goto bad_cleanup_nb_tm;
+
+ return 0;
+
+bad_cleanup_nb_tm:
+ dm_tm_destroy(pmd->nb_tm);
+bad_cleanup_data_sm:
+ dm_sm_destroy(pmd->data_sm);
+bad_cleanup_tm:
+ dm_tm_destroy(pmd->tm);
+ dm_sm_destroy(pmd->metadata_sm);
+
+ return r;
+}
+
+static int __check_incompat_features(struct thin_disk_superblock *disk_super,
+ struct dm_pool_metadata *pmd)
+{
+ uint32_t features;
+
+ features = le32_to_cpu(disk_super->incompat_flags) & ~THIN_FEATURE_INCOMPAT_SUPP;
+ if (features) {
+ DMERR("could not access metadata due to unsupported optional features (%lx).",
+ (unsigned long)features);
+ return -EINVAL;
+ }
+
+ /*
+ * Check for read-only metadata to skip the following RDWR checks.
+ */
+ if (get_disk_ro(pmd->bdev->bd_disk))
+ return 0;
+
+ features = le32_to_cpu(disk_super->compat_ro_flags) & ~THIN_FEATURE_COMPAT_RO_SUPP;
+ if (features) {
+ DMERR("could not access metadata RDWR due to unsupported optional features (%lx).",
+ (unsigned long)features);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int __open_metadata(struct dm_pool_metadata *pmd)
+{
+ int r;
+ struct dm_block *sblock;
+ struct thin_disk_superblock *disk_super;
+
+ r = dm_bm_read_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION,
+ &sb_validator, &sblock);
+ if (r < 0) {
+ DMERR("couldn't read superblock");
+ return r;
+ }
+
+ disk_super = dm_block_data(sblock);
+
+ /* Verify the data block size hasn't changed */
+ if (le32_to_cpu(disk_super->data_block_size) != pmd->data_block_size) {
+ DMERR("changing the data block size (from %u to %llu) is not supported",
+ le32_to_cpu(disk_super->data_block_size),
+ (unsigned long long)pmd->data_block_size);
+ r = -EINVAL;
+ goto bad_unlock_sblock;
+ }
+
+ r = __check_incompat_features(disk_super, pmd);
+ if (r < 0)
+ goto bad_unlock_sblock;
+
+ r = dm_tm_open_with_sm(pmd->bm, THIN_SUPERBLOCK_LOCATION,
+ disk_super->metadata_space_map_root,
+ sizeof(disk_super->metadata_space_map_root),
+ &pmd->tm, &pmd->metadata_sm);
+ if (r < 0) {
+ DMERR("tm_open_with_sm failed");
+ goto bad_unlock_sblock;
+ }
+
+ pmd->data_sm = dm_sm_disk_open(pmd->tm, disk_super->data_space_map_root,
+ sizeof(disk_super->data_space_map_root));
+ if (IS_ERR(pmd->data_sm)) {
+ DMERR("sm_disk_open failed");
+ r = PTR_ERR(pmd->data_sm);
+ goto bad_cleanup_tm;
+ }
+
+ pmd->nb_tm = dm_tm_create_non_blocking_clone(pmd->tm);
+ if (!pmd->nb_tm) {
+ DMERR("could not create non-blocking clone tm");
+ r = -ENOMEM;
+ goto bad_cleanup_data_sm;
+ }
+
+ __setup_btree_details(pmd);
+ dm_bm_unlock(sblock);
+
+ return 0;
+
+bad_cleanup_data_sm:
+ dm_sm_destroy(pmd->data_sm);
+bad_cleanup_tm:
+ dm_tm_destroy(pmd->tm);
+ dm_sm_destroy(pmd->metadata_sm);
+bad_unlock_sblock:
+ dm_bm_unlock(sblock);
+
+ return r;
+}
+
+static int __open_or_format_metadata(struct dm_pool_metadata *pmd, bool format_device)
+{
+ int r, unformatted;
+
+ r = __superblock_all_zeroes(pmd->bm, &unformatted);
+ if (r)
+ return r;
+
+ if (unformatted)
+ return format_device ? __format_metadata(pmd) : -EPERM;
+
+ return __open_metadata(pmd);
+}
+
+static int __create_persistent_data_objects(struct dm_pool_metadata *pmd, bool format_device)
+{
+ int r;
+
+ pmd->bm = dm_block_manager_create(pmd->bdev, THIN_METADATA_BLOCK_SIZE << SECTOR_SHIFT,
+ THIN_MAX_CONCURRENT_LOCKS);
+ if (IS_ERR(pmd->bm)) {
+ DMERR("could not create block manager");
+ return PTR_ERR(pmd->bm);
+ }
+
+ r = __open_or_format_metadata(pmd, format_device);
+ if (r)
+ dm_block_manager_destroy(pmd->bm);
+
+ return r;
+}
+
+static void __destroy_persistent_data_objects(struct dm_pool_metadata *pmd)
+{
+ dm_sm_destroy(pmd->data_sm);
+ dm_sm_destroy(pmd->metadata_sm);
+ dm_tm_destroy(pmd->nb_tm);
+ dm_tm_destroy(pmd->tm);
+ dm_block_manager_destroy(pmd->bm);
+}
+
+static int __begin_transaction(struct dm_pool_metadata *pmd)
+{
+ int r;
+ struct thin_disk_superblock *disk_super;
+ struct dm_block *sblock;
+
+ /*
+ * We re-read the superblock every time. Shouldn't need to do this
+ * really.
+ */
+ r = dm_bm_read_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION,
+ &sb_validator, &sblock);
+ if (r)
+ return r;
+
+ disk_super = dm_block_data(sblock);
+ pmd->time = le32_to_cpu(disk_super->time);
+ pmd->root = le64_to_cpu(disk_super->data_mapping_root);
+ pmd->details_root = le64_to_cpu(disk_super->device_details_root);
+ pmd->trans_id = le64_to_cpu(disk_super->trans_id);
+ pmd->flags = le32_to_cpu(disk_super->flags);
+ pmd->data_block_size = le32_to_cpu(disk_super->data_block_size);
+
+ dm_bm_unlock(sblock);
+ return 0;
+}
+
+static int __write_changed_details(struct dm_pool_metadata *pmd)
+{
+ int r;
+ struct dm_thin_device *td, *tmp;
+ struct disk_device_details details;
+ uint64_t key;
+
+ list_for_each_entry_safe(td, tmp, &pmd->thin_devices, list) {
+ if (!td->changed)
+ continue;
+
+ key = td->id;
+
+ details.mapped_blocks = cpu_to_le64(td->mapped_blocks);
+ details.transaction_id = cpu_to_le64(td->transaction_id);
+ details.creation_time = cpu_to_le32(td->creation_time);
+ details.snapshotted_time = cpu_to_le32(td->snapshotted_time);
+ __dm_bless_for_disk(&details);
+
+ r = dm_btree_insert(&pmd->details_info, pmd->details_root,
+ &key, &details, &pmd->details_root);
+ if (r)
+ return r;
+
+ if (td->open_count)
+ td->changed = 0;
+ else {
+ list_del(&td->list);
+ kfree(td);
+ }
+ }
+
+ return 0;
+}
+
+static int __commit_transaction(struct dm_pool_metadata *pmd)
+{
+ int r;
+ struct thin_disk_superblock *disk_super;
+ struct dm_block *sblock;
+
+ /*
+ * We need to know if the thin_disk_superblock exceeds a 512-byte sector.
+ */
+ BUILD_BUG_ON(sizeof(struct thin_disk_superblock) > 512);
+
+ r = __write_changed_details(pmd);
+ if (r < 0)
+ return r;
+
+ r = dm_sm_commit(pmd->data_sm);
+ if (r < 0)
+ return r;
+
+ r = dm_tm_pre_commit(pmd->tm);
+ if (r < 0)
+ return r;
+
+ r = save_sm_roots(pmd);
+ if (r < 0)
+ return r;
+
+ r = superblock_lock(pmd, &sblock);
+ if (r)
+ return r;
+
+ disk_super = dm_block_data(sblock);
+ disk_super->time = cpu_to_le32(pmd->time);
+ disk_super->data_mapping_root = cpu_to_le64(pmd->root);
+ disk_super->device_details_root = cpu_to_le64(pmd->details_root);
+ disk_super->trans_id = cpu_to_le64(pmd->trans_id);
+ disk_super->flags = cpu_to_le32(pmd->flags);
+
+ copy_sm_roots(pmd, disk_super);
+
+ return dm_tm_commit(pmd->tm, sblock);
+}
+
+static void __set_metadata_reserve(struct dm_pool_metadata *pmd)
+{
+ int r;
+ dm_block_t total;
+ dm_block_t max_blocks = 4096; /* 16M */
+
+ r = dm_sm_get_nr_blocks(pmd->metadata_sm, &total);
+ if (r) {
+ DMERR("could not get size of metadata device");
+ pmd->metadata_reserve = max_blocks;
+ } else
+ pmd->metadata_reserve = min(max_blocks, div_u64(total, 10));
+}
+
+struct dm_pool_metadata *dm_pool_metadata_open(struct block_device *bdev,
+ sector_t data_block_size,
+ bool format_device)
+{
+ int r;
+ struct dm_pool_metadata *pmd;
+
+ pmd = kmalloc(sizeof(*pmd), GFP_KERNEL);
+ if (!pmd) {
+ DMERR("could not allocate metadata struct");
+ return ERR_PTR(-ENOMEM);
+ }
+
+ init_rwsem(&pmd->root_lock);
+ pmd->time = 0;
+ INIT_LIST_HEAD(&pmd->thin_devices);
+ pmd->fail_io = false;
+ pmd->bdev = bdev;
+ pmd->data_block_size = data_block_size;
+
+ r = __create_persistent_data_objects(pmd, format_device);
+ if (r) {
+ kfree(pmd);
+ return ERR_PTR(r);
+ }
+
+ r = __begin_transaction(pmd);
+ if (r < 0) {
+ if (dm_pool_metadata_close(pmd) < 0)
+ DMWARN("%s: dm_pool_metadata_close() failed.", __func__);
+ return ERR_PTR(r);
+ }
+
+ __set_metadata_reserve(pmd);
+
+ return pmd;
+}
+
+int dm_pool_metadata_close(struct dm_pool_metadata *pmd)
+{
+ int r;
+ unsigned open_devices = 0;
+ struct dm_thin_device *td, *tmp;
+
+ down_read(&pmd->root_lock);
+ list_for_each_entry_safe(td, tmp, &pmd->thin_devices, list) {
+ if (td->open_count)
+ open_devices++;
+ else {
+ list_del(&td->list);
+ kfree(td);
+ }
+ }
+ up_read(&pmd->root_lock);
+
+ if (open_devices) {
+ DMERR("attempt to close pmd when %u device(s) are still open",
+ open_devices);
+ return -EBUSY;
+ }
+
+ if (!dm_bm_is_read_only(pmd->bm) && !pmd->fail_io) {
+ r = __commit_transaction(pmd);
+ if (r < 0)
+ DMWARN("%s: __commit_transaction() failed, error = %d",
+ __func__, r);
+ }
+
+ if (!pmd->fail_io)
+ __destroy_persistent_data_objects(pmd);
+
+ kfree(pmd);
+ return 0;
+}
+
+/*
+ * __open_device: Returns @td corresponding to device with id @dev,
+ * creating it if @create is set and incrementing @td->open_count.
+ * On failure, @td is undefined.
+ */
+static int __open_device(struct dm_pool_metadata *pmd,
+ dm_thin_id dev, int create,
+ struct dm_thin_device **td)
+{
+ int r, changed = 0;
+ struct dm_thin_device *td2;
+ uint64_t key = dev;
+ struct disk_device_details details_le;
+
+ /*
+ * If the device is already open, return it.
+ */
+ list_for_each_entry(td2, &pmd->thin_devices, list)
+ if (td2->id == dev) {
+ /*
+ * May not create an already-open device.
+ */
+ if (create)
+ return -EEXIST;
+
+ td2->open_count++;
+ *td = td2;
+ return 0;
+ }
+
+ /*
+ * Check the device exists.
+ */
+ r = dm_btree_lookup(&pmd->details_info, pmd->details_root,
+ &key, &details_le);
+ if (r) {
+ if (r != -ENODATA || !create)
+ return r;
+
+ /*
+ * Create new device.
+ */
+ changed = 1;
+ details_le.mapped_blocks = 0;
+ details_le.transaction_id = cpu_to_le64(pmd->trans_id);
+ details_le.creation_time = cpu_to_le32(pmd->time);
+ details_le.snapshotted_time = cpu_to_le32(pmd->time);
+ }
+
+ *td = kmalloc(sizeof(**td), GFP_NOIO);
+ if (!*td)
+ return -ENOMEM;
+
+ (*td)->pmd = pmd;
+ (*td)->id = dev;
+ (*td)->open_count = 1;
+ (*td)->changed = changed;
+ (*td)->aborted_with_changes = false;
+ (*td)->mapped_blocks = le64_to_cpu(details_le.mapped_blocks);
+ (*td)->transaction_id = le64_to_cpu(details_le.transaction_id);
+ (*td)->creation_time = le32_to_cpu(details_le.creation_time);
+ (*td)->snapshotted_time = le32_to_cpu(details_le.snapshotted_time);
+
+ list_add(&(*td)->list, &pmd->thin_devices);
+
+ return 0;
+}
+
+static void __close_device(struct dm_thin_device *td)
+{
+ --td->open_count;
+}
+
+static int __create_thin(struct dm_pool_metadata *pmd,
+ dm_thin_id dev)
+{
+ int r;
+ dm_block_t dev_root;
+ uint64_t key = dev;
+ struct disk_device_details details_le;
+ struct dm_thin_device *td;
+ __le64 value;
+
+ r = dm_btree_lookup(&pmd->details_info, pmd->details_root,
+ &key, &details_le);
+ if (!r)
+ return -EEXIST;
+
+ /*
+ * Create an empty btree for the mappings.
+ */
+ r = dm_btree_empty(&pmd->bl_info, &dev_root);
+ if (r)
+ return r;
+
+ /*
+ * Insert it into the main mapping tree.
+ */
+ value = cpu_to_le64(dev_root);
+ __dm_bless_for_disk(&value);
+ r = dm_btree_insert(&pmd->tl_info, pmd->root, &key, &value, &pmd->root);
+ if (r) {
+ dm_btree_del(&pmd->bl_info, dev_root);
+ return r;
+ }
+
+ r = __open_device(pmd, dev, 1, &td);
+ if (r) {
+ dm_btree_remove(&pmd->tl_info, pmd->root, &key, &pmd->root);
+ dm_btree_del(&pmd->bl_info, dev_root);
+ return r;
+ }
+ __close_device(td);
+
+ return r;
+}
+
+int dm_pool_create_thin(struct dm_pool_metadata *pmd, dm_thin_id dev)
+{
+ int r = -EINVAL;
+
+ down_write(&pmd->root_lock);
+ if (!pmd->fail_io)
+ r = __create_thin(pmd, dev);
+ up_write(&pmd->root_lock);
+
+ return r;
+}
+
+static int __set_snapshot_details(struct dm_pool_metadata *pmd,
+ struct dm_thin_device *snap,
+ dm_thin_id origin, uint32_t time)
+{
+ int r;
+ struct dm_thin_device *td;
+
+ r = __open_device(pmd, origin, 0, &td);
+ if (r)
+ return r;
+
+ td->changed = 1;
+ td->snapshotted_time = time;
+
+ snap->mapped_blocks = td->mapped_blocks;
+ snap->snapshotted_time = time;
+ __close_device(td);
+
+ return 0;
+}
+
+static int __create_snap(struct dm_pool_metadata *pmd,
+ dm_thin_id dev, dm_thin_id origin)
+{
+ int r;
+ dm_block_t origin_root;
+ uint64_t key = origin, dev_key = dev;
+ struct dm_thin_device *td;
+ struct disk_device_details details_le;
+ __le64 value;
+
+ /* check this device is unused */
+ r = dm_btree_lookup(&pmd->details_info, pmd->details_root,
+ &dev_key, &details_le);
+ if (!r)
+ return -EEXIST;
+
+ /* find the mapping tree for the origin */
+ r = dm_btree_lookup(&pmd->tl_info, pmd->root, &key, &value);
+ if (r)
+ return r;
+ origin_root = le64_to_cpu(value);
+
+ /* clone the origin, an inc will do */
+ dm_tm_inc(pmd->tm, origin_root);
+
+ /* insert into the main mapping tree */
+ value = cpu_to_le64(origin_root);
+ __dm_bless_for_disk(&value);
+ key = dev;
+ r = dm_btree_insert(&pmd->tl_info, pmd->root, &key, &value, &pmd->root);
+ if (r) {
+ dm_tm_dec(pmd->tm, origin_root);
+ return r;
+ }
+
+ pmd->time++;
+
+ r = __open_device(pmd, dev, 1, &td);
+ if (r)
+ goto bad;
+
+ r = __set_snapshot_details(pmd, td, origin, pmd->time);
+ __close_device(td);
+
+ if (r)
+ goto bad;
+
+ return 0;
+
+bad:
+ dm_btree_remove(&pmd->tl_info, pmd->root, &key, &pmd->root);
+ dm_btree_remove(&pmd->details_info, pmd->details_root,
+ &key, &pmd->details_root);
+ return r;
+}
+
+int dm_pool_create_snap(struct dm_pool_metadata *pmd,
+ dm_thin_id dev,
+ dm_thin_id origin)
+{
+ int r = -EINVAL;
+
+ down_write(&pmd->root_lock);
+ if (!pmd->fail_io)
+ r = __create_snap(pmd, dev, origin);
+ up_write(&pmd->root_lock);
+
+ return r;
+}
+
+static int __delete_device(struct dm_pool_metadata *pmd, dm_thin_id dev)
+{
+ int r;
+ uint64_t key = dev;
+ struct dm_thin_device *td;
+
+ /* TODO: failure should mark the transaction invalid */
+ r = __open_device(pmd, dev, 0, &td);
+ if (r)
+ return r;
+
+ if (td->open_count > 1) {
+ __close_device(td);
+ return -EBUSY;
+ }
+
+ list_del(&td->list);
+ kfree(td);
+ r = dm_btree_remove(&pmd->details_info, pmd->details_root,
+ &key, &pmd->details_root);
+ if (r)
+ return r;
+
+ r = dm_btree_remove(&pmd->tl_info, pmd->root, &key, &pmd->root);
+ if (r)
+ return r;
+
+ return 0;
+}
+
+int dm_pool_delete_thin_device(struct dm_pool_metadata *pmd,
+ dm_thin_id dev)
+{
+ int r = -EINVAL;
+
+ down_write(&pmd->root_lock);
+ if (!pmd->fail_io)
+ r = __delete_device(pmd, dev);
+ up_write(&pmd->root_lock);
+
+ return r;
+}
+
+int dm_pool_set_metadata_transaction_id(struct dm_pool_metadata *pmd,
+ uint64_t current_id,
+ uint64_t new_id)
+{
+ int r = -EINVAL;
+
+ down_write(&pmd->root_lock);
+
+ if (pmd->fail_io)
+ goto out;
+
+ if (pmd->trans_id != current_id) {
+ DMERR("mismatched transaction id");
+ goto out;
+ }
+
+ pmd->trans_id = new_id;
+ r = 0;
+
+out:
+ up_write(&pmd->root_lock);
+
+ return r;
+}
+
+int dm_pool_get_metadata_transaction_id(struct dm_pool_metadata *pmd,
+ uint64_t *result)
+{
+ int r = -EINVAL;
+
+ down_read(&pmd->root_lock);
+ if (!pmd->fail_io) {
+ *result = pmd->trans_id;
+ r = 0;
+ }
+ up_read(&pmd->root_lock);
+
+ return r;
+}
+
+static int __reserve_metadata_snap(struct dm_pool_metadata *pmd)
+{
+ int r, inc;
+ struct thin_disk_superblock *disk_super;
+ struct dm_block *copy, *sblock;
+ dm_block_t held_root;
+
+ /*
+ * We commit to ensure the btree roots which we increment in a
+ * moment are up to date.
+ */
+ __commit_transaction(pmd);
+
+ /*
+ * Copy the superblock.
+ */
+ dm_sm_inc_block(pmd->metadata_sm, THIN_SUPERBLOCK_LOCATION);
+ r = dm_tm_shadow_block(pmd->tm, THIN_SUPERBLOCK_LOCATION,
+ &sb_validator, ©, &inc);
+ if (r)
+ return r;
+
+ BUG_ON(!inc);
+
+ held_root = dm_block_location(copy);
+ disk_super = dm_block_data(copy);
+
+ if (le64_to_cpu(disk_super->held_root)) {
+ DMWARN("Pool metadata snapshot already exists: release this before taking another.");
+
+ dm_tm_dec(pmd->tm, held_root);
+ dm_tm_unlock(pmd->tm, copy);
+ return -EBUSY;
+ }
+
+ /*
+ * Wipe the spacemap since we're not publishing this.
+ */
+ memset(&disk_super->data_space_map_root, 0,
+ sizeof(disk_super->data_space_map_root));
+ memset(&disk_super->metadata_space_map_root, 0,
+ sizeof(disk_super->metadata_space_map_root));
+
+ /*
+ * Increment the data structures that need to be preserved.
+ */
+ dm_tm_inc(pmd->tm, le64_to_cpu(disk_super->data_mapping_root));
+ dm_tm_inc(pmd->tm, le64_to_cpu(disk_super->device_details_root));
+ dm_tm_unlock(pmd->tm, copy);
+
+ /*
+ * Write the held root into the superblock.
+ */
+ r = superblock_lock(pmd, &sblock);
+ if (r) {
+ dm_tm_dec(pmd->tm, held_root);
+ return r;
+ }
+
+ disk_super = dm_block_data(sblock);
+ disk_super->held_root = cpu_to_le64(held_root);
+ dm_bm_unlock(sblock);
+ return 0;
+}
+
+int dm_pool_reserve_metadata_snap(struct dm_pool_metadata *pmd)
+{
+ int r = -EINVAL;
+
+ down_write(&pmd->root_lock);
+ if (!pmd->fail_io)
+ r = __reserve_metadata_snap(pmd);
+ up_write(&pmd->root_lock);
+
+ return r;
+}
+
+static int __release_metadata_snap(struct dm_pool_metadata *pmd)
+{
+ int r;
+ struct thin_disk_superblock *disk_super;
+ struct dm_block *sblock, *copy;
+ dm_block_t held_root;
+
+ r = superblock_lock(pmd, &sblock);
+ if (r)
+ return r;
+
+ disk_super = dm_block_data(sblock);
+ held_root = le64_to_cpu(disk_super->held_root);
+ disk_super->held_root = cpu_to_le64(0);
+
+ dm_bm_unlock(sblock);
+
+ if (!held_root) {
+ DMWARN("No pool metadata snapshot found: nothing to release.");
+ return -EINVAL;
+ }
+
+ r = dm_tm_read_lock(pmd->tm, held_root, &sb_validator, ©);
+ if (r)
+ return r;
+
+ disk_super = dm_block_data(copy);
+ dm_btree_del(&pmd->info, le64_to_cpu(disk_super->data_mapping_root));
+ dm_btree_del(&pmd->details_info, le64_to_cpu(disk_super->device_details_root));
+ dm_sm_dec_block(pmd->metadata_sm, held_root);
+
+ dm_tm_unlock(pmd->tm, copy);
+
+ return 0;
+}
+
+int dm_pool_release_metadata_snap(struct dm_pool_metadata *pmd)
+{
+ int r = -EINVAL;
+
+ down_write(&pmd->root_lock);
+ if (!pmd->fail_io)
+ r = __release_metadata_snap(pmd);
+ up_write(&pmd->root_lock);
+
+ return r;
+}
+
+static int __get_metadata_snap(struct dm_pool_metadata *pmd,
+ dm_block_t *result)
+{
+ int r;
+ struct thin_disk_superblock *disk_super;
+ struct dm_block *sblock;
+
+ r = dm_bm_read_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION,
+ &sb_validator, &sblock);
+ if (r)
+ return r;
+
+ disk_super = dm_block_data(sblock);
+ *result = le64_to_cpu(disk_super->held_root);
+
+ dm_bm_unlock(sblock);
+
+ return 0;
+}
+
+int dm_pool_get_metadata_snap(struct dm_pool_metadata *pmd,
+ dm_block_t *result)
+{
+ int r = -EINVAL;
+
+ down_read(&pmd->root_lock);
+ if (!pmd->fail_io)
+ r = __get_metadata_snap(pmd, result);
+ up_read(&pmd->root_lock);
+
+ return r;
+}
+
+int dm_pool_open_thin_device(struct dm_pool_metadata *pmd, dm_thin_id dev,
+ struct dm_thin_device **td)
+{
+ int r = -EINVAL;
+
+ down_write(&pmd->root_lock);
+ if (!pmd->fail_io)
+ r = __open_device(pmd, dev, 0, td);
+ up_write(&pmd->root_lock);
+
+ return r;
+}
+
+int dm_pool_close_thin_device(struct dm_thin_device *td)
+{
+ down_write(&td->pmd->root_lock);
+ __close_device(td);
+ up_write(&td->pmd->root_lock);
+
+ return 0;
+}
+
+dm_thin_id dm_thin_dev_id(struct dm_thin_device *td)
+{
+ return td->id;
+}
+
+/*
+ * Check whether @time (of block creation) is older than @td's last snapshot.
+ * If so then the associated block is shared with the last snapshot device.
+ * Any block on a device created *after* the device last got snapshotted is
+ * necessarily not shared.
+ */
+static bool __snapshotted_since(struct dm_thin_device *td, uint32_t time)
+{
+ return td->snapshotted_time > time;
+}
+
+static void unpack_lookup_result(struct dm_thin_device *td, __le64 value,
+ struct dm_thin_lookup_result *result)
+{
+ uint64_t block_time = 0;
+ dm_block_t exception_block;
+ uint32_t exception_time;
+
+ block_time = le64_to_cpu(value);
+ unpack_block_time(block_time, &exception_block, &exception_time);
+ result->block = exception_block;
+ result->shared = __snapshotted_since(td, exception_time);
+}
+
+static int __find_block(struct dm_thin_device *td, dm_block_t block,
+ int can_issue_io, struct dm_thin_lookup_result *result)
+{
+ int r;
+ __le64 value;
+ struct dm_pool_metadata *pmd = td->pmd;
+ dm_block_t keys[2] = { td->id, block };
+ struct dm_btree_info *info;
+
+ if (can_issue_io) {
+ info = &pmd->info;
+ } else
+ info = &pmd->nb_info;
+
+ r = dm_btree_lookup(info, pmd->root, keys, &value);
+ if (!r)
+ unpack_lookup_result(td, value, result);
+
+ return r;
+}
+
+int dm_thin_find_block(struct dm_thin_device *td, dm_block_t block,
+ int can_issue_io, struct dm_thin_lookup_result *result)
+{
+ int r;
+ struct dm_pool_metadata *pmd = td->pmd;
+
+ down_read(&pmd->root_lock);
+ if (pmd->fail_io) {
+ up_read(&pmd->root_lock);
+ return -EINVAL;
+ }
+
+ r = __find_block(td, block, can_issue_io, result);
+
+ up_read(&pmd->root_lock);
+ return r;
+}
+
+static int __find_next_mapped_block(struct dm_thin_device *td, dm_block_t block,
+ dm_block_t *vblock,
+ struct dm_thin_lookup_result *result)
+{
+ int r;
+ __le64 value;
+ struct dm_pool_metadata *pmd = td->pmd;
+ dm_block_t keys[2] = { td->id, block };
+
+ r = dm_btree_lookup_next(&pmd->info, pmd->root, keys, vblock, &value);
+ if (!r)
+ unpack_lookup_result(td, value, result);
+
+ return r;
+}
+
+static int __find_mapped_range(struct dm_thin_device *td,
+ dm_block_t begin, dm_block_t end,
+ dm_block_t *thin_begin, dm_block_t *thin_end,
+ dm_block_t *pool_begin, bool *maybe_shared)
+{
+ int r;
+ dm_block_t pool_end;
+ struct dm_thin_lookup_result lookup;
+
+ if (end < begin)
+ return -ENODATA;
+
+ r = __find_next_mapped_block(td, begin, &begin, &lookup);
+ if (r)
+ return r;
+
+ if (begin >= end)
+ return -ENODATA;
+
+ *thin_begin = begin;
+ *pool_begin = lookup.block;
+ *maybe_shared = lookup.shared;
+
+ begin++;
+ pool_end = *pool_begin + 1;
+ while (begin != end) {
+ r = __find_block(td, begin, true, &lookup);
+ if (r) {
+ if (r == -ENODATA)
+ break;
+ else
+ return r;
+ }
+
+ if ((lookup.block != pool_end) ||
+ (lookup.shared != *maybe_shared))
+ break;
+
+ pool_end++;
+ begin++;
+ }
+
+ *thin_end = begin;
+ return 0;
+}
+
+int dm_thin_find_mapped_range(struct dm_thin_device *td,
+ dm_block_t begin, dm_block_t end,
+ dm_block_t *thin_begin, dm_block_t *thin_end,
+ dm_block_t *pool_begin, bool *maybe_shared)
+{
+ int r = -EINVAL;
+ struct dm_pool_metadata *pmd = td->pmd;
+
+ down_read(&pmd->root_lock);
+ if (!pmd->fail_io) {
+ r = __find_mapped_range(td, begin, end, thin_begin, thin_end,
+ pool_begin, maybe_shared);
+ }
+ up_read(&pmd->root_lock);
+
+ return r;
+}
+
+static int __insert(struct dm_thin_device *td, dm_block_t block,
+ dm_block_t data_block)
+{
+ int r, inserted;
+ __le64 value;
+ struct dm_pool_metadata *pmd = td->pmd;
+ dm_block_t keys[2] = { td->id, block };
+
+ value = cpu_to_le64(pack_block_time(data_block, pmd->time));
+ __dm_bless_for_disk(&value);
+
+ r = dm_btree_insert_notify(&pmd->info, pmd->root, keys, &value,
+ &pmd->root, &inserted);
+ if (r)
+ return r;
+
+ td->changed = 1;
+ if (inserted)
+ td->mapped_blocks++;
+
+ return 0;
+}
+
+int dm_thin_insert_block(struct dm_thin_device *td, dm_block_t block,
+ dm_block_t data_block)
+{
+ int r = -EINVAL;
+
+ down_write(&td->pmd->root_lock);
+ if (!td->pmd->fail_io)
+ r = __insert(td, block, data_block);
+ up_write(&td->pmd->root_lock);
+
+ return r;
+}
+
+static int __remove(struct dm_thin_device *td, dm_block_t block)
+{
+ int r;
+ struct dm_pool_metadata *pmd = td->pmd;
+ dm_block_t keys[2] = { td->id, block };
+
+ r = dm_btree_remove(&pmd->info, pmd->root, keys, &pmd->root);
+ if (r)
+ return r;
+
+ td->mapped_blocks--;
+ td->changed = 1;
+
+ return 0;
+}
+
+static int __remove_range(struct dm_thin_device *td, dm_block_t begin, dm_block_t end)
+{
+ int r;
+ unsigned count, total_count = 0;
+ struct dm_pool_metadata *pmd = td->pmd;
+ dm_block_t keys[1] = { td->id };
+ __le64 value;
+ dm_block_t mapping_root;
+
+ /*
+ * Find the mapping tree
+ */
+ r = dm_btree_lookup(&pmd->tl_info, pmd->root, keys, &value);
+ if (r)
+ return r;
+
+ /*
+ * Remove from the mapping tree, taking care to inc the
+ * ref count so it doesn't get deleted.
+ */
+ mapping_root = le64_to_cpu(value);
+ dm_tm_inc(pmd->tm, mapping_root);
+ r = dm_btree_remove(&pmd->tl_info, pmd->root, keys, &pmd->root);
+ if (r)
+ return r;
+
+ /*
+ * Remove leaves stops at the first unmapped entry, so we have to
+ * loop round finding mapped ranges.
+ */
+ while (begin < end) {
+ r = dm_btree_lookup_next(&pmd->bl_info, mapping_root, &begin, &begin, &value);
+ if (r == -ENODATA)
+ break;
+
+ if (r)
+ return r;
+
+ if (begin >= end)
+ break;
+
+ r = dm_btree_remove_leaves(&pmd->bl_info, mapping_root, &begin, end, &mapping_root, &count);
+ if (r)
+ return r;
+
+ total_count += count;
+ }
+
+ td->mapped_blocks -= total_count;
+ td->changed = 1;
+
+ /*
+ * Reinsert the mapping tree.
+ */
+ value = cpu_to_le64(mapping_root);
+ __dm_bless_for_disk(&value);
+ return dm_btree_insert(&pmd->tl_info, pmd->root, keys, &value, &pmd->root);
+}
+
+int dm_thin_remove_block(struct dm_thin_device *td, dm_block_t block)
+{
+ int r = -EINVAL;
+
+ down_write(&td->pmd->root_lock);
+ if (!td->pmd->fail_io)
+ r = __remove(td, block);
+ up_write(&td->pmd->root_lock);
+
+ return r;
+}
+
+int dm_thin_remove_range(struct dm_thin_device *td,
+ dm_block_t begin, dm_block_t end)
+{
+ int r = -EINVAL;
+
+ down_write(&td->pmd->root_lock);
+ if (!td->pmd->fail_io)
+ r = __remove_range(td, begin, end);
+ up_write(&td->pmd->root_lock);
+
+ return r;
+}
+
+int dm_pool_block_is_used(struct dm_pool_metadata *pmd, dm_block_t b, bool *result)
+{
+ int r;
+ uint32_t ref_count;
+
+ down_read(&pmd->root_lock);
+ r = dm_sm_get_count(pmd->data_sm, b, &ref_count);
+ if (!r)
+ *result = (ref_count != 0);
+ up_read(&pmd->root_lock);
+
+ return r;
+}
+
+int dm_pool_inc_data_range(struct dm_pool_metadata *pmd, dm_block_t b, dm_block_t e)
+{
+ int r = 0;
+
+ down_write(&pmd->root_lock);
+ for (; b != e; b++) {
+ r = dm_sm_inc_block(pmd->data_sm, b);
+ if (r)
+ break;
+ }
+ up_write(&pmd->root_lock);
+
+ return r;
+}
+
+int dm_pool_dec_data_range(struct dm_pool_metadata *pmd, dm_block_t b, dm_block_t e)
+{
+ int r = 0;
+
+ down_write(&pmd->root_lock);
+ for (; b != e; b++) {
+ r = dm_sm_dec_block(pmd->data_sm, b);
+ if (r)
+ break;
+ }
+ up_write(&pmd->root_lock);
+
+ return r;
+}
+
+bool dm_thin_changed_this_transaction(struct dm_thin_device *td)
+{
+ int r;
+
+ down_read(&td->pmd->root_lock);
+ r = td->changed;
+ up_read(&td->pmd->root_lock);
+
+ return r;
+}
+
+bool dm_pool_changed_this_transaction(struct dm_pool_metadata *pmd)
+{
+ bool r = false;
+ struct dm_thin_device *td, *tmp;
+
+ down_read(&pmd->root_lock);
+ list_for_each_entry_safe(td, tmp, &pmd->thin_devices, list) {
+ if (td->changed) {
+ r = td->changed;
+ break;
+ }
+ }
+ up_read(&pmd->root_lock);
+
+ return r;
+}
+
+bool dm_thin_aborted_changes(struct dm_thin_device *td)
+{
+ bool r;
+
+ down_read(&td->pmd->root_lock);
+ r = td->aborted_with_changes;
+ up_read(&td->pmd->root_lock);
+
+ return r;
+}
+
+int dm_pool_alloc_data_block(struct dm_pool_metadata *pmd, dm_block_t *result)
+{
+ int r = -EINVAL;
+
+ down_write(&pmd->root_lock);
+ if (!pmd->fail_io)
+ r = dm_sm_new_block(pmd->data_sm, result);
+ up_write(&pmd->root_lock);
+
+ return r;
+}
+
+int dm_pool_commit_metadata(struct dm_pool_metadata *pmd)
+{
+ int r = -EINVAL;
+
+ down_write(&pmd->root_lock);
+ if (pmd->fail_io)
+ goto out;
+
+ r = __commit_transaction(pmd);
+ if (r <= 0)
+ goto out;
+
+ /*
+ * Open the next transaction.
+ */
+ r = __begin_transaction(pmd);
+out:
+ up_write(&pmd->root_lock);
+ return r;
+}
+
+static void __set_abort_with_changes_flags(struct dm_pool_metadata *pmd)
+{
+ struct dm_thin_device *td;
+
+ list_for_each_entry(td, &pmd->thin_devices, list)
+ td->aborted_with_changes = td->changed;
+}
+
+int dm_pool_abort_metadata(struct dm_pool_metadata *pmd)
+{
+ int r = -EINVAL;
+
+ down_write(&pmd->root_lock);
+ if (pmd->fail_io)
+ goto out;
+
+ __set_abort_with_changes_flags(pmd);
+ __destroy_persistent_data_objects(pmd);
+ r = __create_persistent_data_objects(pmd, false);
+ if (r)
+ pmd->fail_io = true;
+
+out:
+ up_write(&pmd->root_lock);
+
+ return r;
+}
+
+int dm_pool_get_free_block_count(struct dm_pool_metadata *pmd, dm_block_t *result)
+{
+ int r = -EINVAL;
+
+ down_read(&pmd->root_lock);
+ if (!pmd->fail_io)
+ r = dm_sm_get_nr_free(pmd->data_sm, result);
+ up_read(&pmd->root_lock);
+
+ return r;
+}
+
+int dm_pool_get_free_metadata_block_count(struct dm_pool_metadata *pmd,
+ dm_block_t *result)
+{
+ int r = -EINVAL;
+
+ down_read(&pmd->root_lock);
+ if (!pmd->fail_io)
+ r = dm_sm_get_nr_free(pmd->metadata_sm, result);
+
+ if (!r) {
+ if (*result < pmd->metadata_reserve)
+ *result = 0;
+ else
+ *result -= pmd->metadata_reserve;
+ }
+ up_read(&pmd->root_lock);
+
+ return r;
+}
+
+int dm_pool_get_metadata_dev_size(struct dm_pool_metadata *pmd,
+ dm_block_t *result)
+{
+ int r = -EINVAL;
+
+ down_read(&pmd->root_lock);
+ if (!pmd->fail_io)
+ r = dm_sm_get_nr_blocks(pmd->metadata_sm, result);
+ up_read(&pmd->root_lock);
+
+ return r;
+}
+
+int dm_pool_get_data_dev_size(struct dm_pool_metadata *pmd, dm_block_t *result)
+{
+ int r = -EINVAL;
+
+ down_read(&pmd->root_lock);
+ if (!pmd->fail_io)
+ r = dm_sm_get_nr_blocks(pmd->data_sm, result);
+ up_read(&pmd->root_lock);
+
+ return r;
+}
+
+int dm_thin_get_mapped_count(struct dm_thin_device *td, dm_block_t *result)
+{
+ int r = -EINVAL;
+ struct dm_pool_metadata *pmd = td->pmd;
+
+ down_read(&pmd->root_lock);
+ if (!pmd->fail_io) {
+ *result = td->mapped_blocks;
+ r = 0;
+ }
+ up_read(&pmd->root_lock);
+
+ return r;
+}
+
+static int __highest_block(struct dm_thin_device *td, dm_block_t *result)
+{
+ int r;
+ __le64 value_le;
+ dm_block_t thin_root;
+ struct dm_pool_metadata *pmd = td->pmd;
+
+ r = dm_btree_lookup(&pmd->tl_info, pmd->root, &td->id, &value_le);
+ if (r)
+ return r;
+
+ thin_root = le64_to_cpu(value_le);
+
+ return dm_btree_find_highest_key(&pmd->bl_info, thin_root, result);
+}
+
+int dm_thin_get_highest_mapped_block(struct dm_thin_device *td,
+ dm_block_t *result)
+{
+ int r = -EINVAL;
+ struct dm_pool_metadata *pmd = td->pmd;
+
+ down_read(&pmd->root_lock);
+ if (!pmd->fail_io)
+ r = __highest_block(td, result);
+ up_read(&pmd->root_lock);
+
+ return r;
+}
+
+static int __resize_space_map(struct dm_space_map *sm, dm_block_t new_count)
+{
+ int r;
+ dm_block_t old_count;
+
+ r = dm_sm_get_nr_blocks(sm, &old_count);
+ if (r)
+ return r;
+
+ if (new_count == old_count)
+ return 0;
+
+ if (new_count < old_count) {
+ DMERR("cannot reduce size of space map");
+ return -EINVAL;
+ }
+
+ return dm_sm_extend(sm, new_count - old_count);
+}
+
+int dm_pool_resize_data_dev(struct dm_pool_metadata *pmd, dm_block_t new_count)
+{
+ int r = -EINVAL;
+
+ down_write(&pmd->root_lock);
+ if (!pmd->fail_io)
+ r = __resize_space_map(pmd->data_sm, new_count);
+ up_write(&pmd->root_lock);
+
+ return r;
+}
+
+int dm_pool_resize_metadata_dev(struct dm_pool_metadata *pmd, dm_block_t new_count)
+{
+ int r = -EINVAL;
+
+ down_write(&pmd->root_lock);
+ if (!pmd->fail_io) {
+ r = __resize_space_map(pmd->metadata_sm, new_count);
+ if (!r)
+ __set_metadata_reserve(pmd);
+ }
+ up_write(&pmd->root_lock);
+
+ return r;
+}
+
+void dm_pool_metadata_read_only(struct dm_pool_metadata *pmd)
+{
+ down_write(&pmd->root_lock);
+ dm_bm_set_read_only(pmd->bm);
+ up_write(&pmd->root_lock);
+}
+
+void dm_pool_metadata_read_write(struct dm_pool_metadata *pmd)
+{
+ down_write(&pmd->root_lock);
+ dm_bm_set_read_write(pmd->bm);
+ up_write(&pmd->root_lock);
+}
+
+int dm_pool_register_metadata_threshold(struct dm_pool_metadata *pmd,
+ dm_block_t threshold,
+ dm_sm_threshold_fn fn,
+ void *context)
+{
+ int r;
+
+ down_write(&pmd->root_lock);
+ r = dm_sm_register_threshold_callback(pmd->metadata_sm, threshold, fn, context);
+ up_write(&pmd->root_lock);
+
+ return r;
+}
+
+int dm_pool_metadata_set_needs_check(struct dm_pool_metadata *pmd)
+{
+ int r;
+ struct dm_block *sblock;
+ struct thin_disk_superblock *disk_super;
+
+ down_write(&pmd->root_lock);
+ pmd->flags |= THIN_METADATA_NEEDS_CHECK_FLAG;
+
+ r = superblock_lock(pmd, &sblock);
+ if (r) {
+ DMERR("couldn't read superblock");
+ goto out;
+ }
+
+ disk_super = dm_block_data(sblock);
+ disk_super->flags = cpu_to_le32(pmd->flags);
+
+ dm_bm_unlock(sblock);
+out:
+ up_write(&pmd->root_lock);
+ return r;
+}
+
+bool dm_pool_metadata_needs_check(struct dm_pool_metadata *pmd)
+{
+ bool needs_check;
+
+ down_read(&pmd->root_lock);
+ needs_check = pmd->flags & THIN_METADATA_NEEDS_CHECK_FLAG;
+ up_read(&pmd->root_lock);
+
+ return needs_check;
+}
+
+void dm_pool_issue_prefetches(struct dm_pool_metadata *pmd)
+{
+ down_read(&pmd->root_lock);
+ if (!pmd->fail_io)
+ dm_tm_issue_prefetches(pmd->tm);
+ up_read(&pmd->root_lock);
+}