diff options
Diffstat (limited to 'fs/btrfs/volumes.c')
-rw-r--r-- | fs/btrfs/volumes.c | 872 |
1 files changed, 872 insertions, 0 deletions
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c new file mode 100644 index 0000000000..c671b53426 --- /dev/null +++ b/fs/btrfs/volumes.c @@ -0,0 +1,872 @@ +// SPDX-License-Identifier: GPL-2.0+ +#include <stdlib.h> +#include <common.h> +#include <fs_internal.h> +#include "ctree.h" +#include "disk-io.h" +#include "volumes.h" + +const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = { + [BTRFS_RAID_RAID10] = { + .sub_stripes = 2, + .dev_stripes = 1, + .devs_max = 0, /* 0 == as many as possible */ + .devs_min = 4, + .tolerated_failures = 1, + .devs_increment = 2, + .ncopies = 2, + .nparity = 0, + .raid_name = "raid10", + .bg_flag = BTRFS_BLOCK_GROUP_RAID10, + }, + [BTRFS_RAID_RAID1] = { + .sub_stripes = 1, + .dev_stripes = 1, + .devs_max = 2, + .devs_min = 2, + .tolerated_failures = 1, + .devs_increment = 2, + .ncopies = 2, + .nparity = 0, + .raid_name = "raid1", + .bg_flag = BTRFS_BLOCK_GROUP_RAID1, + }, + [BTRFS_RAID_RAID1C3] = { + .sub_stripes = 1, + .dev_stripes = 1, + .devs_max = 3, + .devs_min = 3, + .tolerated_failures = 2, + .devs_increment = 3, + .ncopies = 3, + .raid_name = "raid1c3", + .bg_flag = BTRFS_BLOCK_GROUP_RAID1C3, + }, + [BTRFS_RAID_RAID1C4] = { + .sub_stripes = 1, + .dev_stripes = 1, + .devs_max = 4, + .devs_min = 4, + .tolerated_failures = 3, + .devs_increment = 4, + .ncopies = 4, + .raid_name = "raid1c4", + .bg_flag = BTRFS_BLOCK_GROUP_RAID1C4, + }, + [BTRFS_RAID_DUP] = { + .sub_stripes = 1, + .dev_stripes = 2, + .devs_max = 1, + .devs_min = 1, + .tolerated_failures = 0, + .devs_increment = 1, + .ncopies = 2, + .nparity = 0, + .raid_name = "dup", + .bg_flag = BTRFS_BLOCK_GROUP_DUP, + }, + [BTRFS_RAID_RAID0] = { + .sub_stripes = 1, + .dev_stripes = 1, + .devs_max = 0, + .devs_min = 2, + .tolerated_failures = 0, + .devs_increment = 1, + .ncopies = 1, + .nparity = 0, + .raid_name = "raid0", + .bg_flag = BTRFS_BLOCK_GROUP_RAID0, + }, + [BTRFS_RAID_SINGLE] = { + .sub_stripes = 1, + .dev_stripes = 1, + .devs_max = 1, + .devs_min = 1, + .tolerated_failures = 0, + .devs_increment = 1, + .ncopies = 1, + .nparity = 0, + .raid_name = "single", + .bg_flag = 0, + }, + [BTRFS_RAID_RAID5] = { + .sub_stripes = 1, + .dev_stripes = 1, + .devs_max = 0, + .devs_min = 2, + .tolerated_failures = 1, + .devs_increment = 1, + .ncopies = 1, + .nparity = 1, + .raid_name = "raid5", + .bg_flag = BTRFS_BLOCK_GROUP_RAID5, + }, + [BTRFS_RAID_RAID6] = { + .sub_stripes = 1, + .dev_stripes = 1, + .devs_max = 0, + .devs_min = 3, + .tolerated_failures = 2, + .devs_increment = 1, + .ncopies = 1, + .nparity = 2, + .raid_name = "raid6", + .bg_flag = BTRFS_BLOCK_GROUP_RAID6, + }, +}; + +struct stripe { + struct btrfs_device *dev; + u64 physical; +}; + +static inline int nr_parity_stripes(struct map_lookup *map) +{ + if (map->type & BTRFS_BLOCK_GROUP_RAID5) + return 1; + else if (map->type & BTRFS_BLOCK_GROUP_RAID6) + return 2; + else + return 0; +} + +static inline int nr_data_stripes(struct map_lookup *map) +{ + return map->num_stripes - nr_parity_stripes(map); +} + +#define is_parity_stripe(x) ( ((x) == BTRFS_RAID5_P_STRIPE) || ((x) == BTRFS_RAID6_Q_STRIPE) ) + +static LIST_HEAD(fs_uuids); + +/* + * Find a device specified by @devid or @uuid in the list of @fs_devices, or + * return NULL. + * + * If devid and uuid are both specified, the match must be exact, otherwise + * only devid is used. + */ +static struct btrfs_device *find_device(struct btrfs_fs_devices *fs_devices, + u64 devid, u8 *uuid) +{ + struct list_head *head = &fs_devices->devices; + struct btrfs_device *dev; + + list_for_each_entry(dev, head, dev_list) { + if (dev->devid == devid && + (!uuid || !memcmp(dev->uuid, uuid, BTRFS_UUID_SIZE))) { + return dev; + } + } + return NULL; +} + +static struct btrfs_fs_devices *find_fsid(u8 *fsid, u8 *metadata_uuid) +{ + struct btrfs_fs_devices *fs_devices; + + list_for_each_entry(fs_devices, &fs_uuids, list) { + if (metadata_uuid && (memcmp(fsid, fs_devices->fsid, + BTRFS_FSID_SIZE) == 0) && + (memcmp(metadata_uuid, fs_devices->metadata_uuid, + BTRFS_FSID_SIZE) == 0)) { + return fs_devices; + } else if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) == 0){ + return fs_devices; + } + } + return NULL; +} + +static int device_list_add(struct btrfs_super_block *disk_super, + u64 devid, struct blk_desc *desc, + struct disk_partition *part, + struct btrfs_fs_devices **fs_devices_ret) +{ + struct btrfs_device *device; + struct btrfs_fs_devices *fs_devices; + u64 found_transid = btrfs_super_generation(disk_super); + bool metadata_uuid = (btrfs_super_incompat_flags(disk_super) & + BTRFS_FEATURE_INCOMPAT_METADATA_UUID); + + if (metadata_uuid) + fs_devices = find_fsid(disk_super->fsid, + disk_super->metadata_uuid); + else + fs_devices = find_fsid(disk_super->fsid, NULL); + + if (!fs_devices) { + fs_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS); + if (!fs_devices) + return -ENOMEM; + INIT_LIST_HEAD(&fs_devices->devices); + list_add(&fs_devices->list, &fs_uuids); + memcpy(fs_devices->fsid, disk_super->fsid, BTRFS_FSID_SIZE); + if (metadata_uuid) + memcpy(fs_devices->metadata_uuid, + disk_super->metadata_uuid, BTRFS_FSID_SIZE); + else + memcpy(fs_devices->metadata_uuid, fs_devices->fsid, + BTRFS_FSID_SIZE); + + fs_devices->latest_devid = devid; + fs_devices->latest_trans = found_transid; + fs_devices->lowest_devid = (u64)-1; + device = NULL; + } else { + device = find_device(fs_devices, devid, + disk_super->dev_item.uuid); + } + if (!device) { + device = kzalloc(sizeof(*device), GFP_NOFS); + if (!device) { + /* we can safely leave the fs_devices entry around */ + return -ENOMEM; + } + device->devid = devid; + device->desc = desc; + device->part = part; + device->generation = found_transid; + memcpy(device->uuid, disk_super->dev_item.uuid, + BTRFS_UUID_SIZE); + device->total_devs = btrfs_super_num_devices(disk_super); + device->super_bytes_used = btrfs_super_bytes_used(disk_super); + device->total_bytes = + btrfs_stack_device_total_bytes(&disk_super->dev_item); + device->bytes_used = + btrfs_stack_device_bytes_used(&disk_super->dev_item); + list_add(&device->dev_list, &fs_devices->devices); + device->fs_devices = fs_devices; + } else if (!device->desc || !device->part) { + /* + * The existing device has newer generation, so this one could + * be a stale one, don't add it. + */ + if (found_transid < device->generation) { + error( + "adding devid %llu gen %llu but found an existing device gen %llu", + device->devid, found_transid, + device->generation); + return -EEXIST; + } else { + device->desc = desc; + device->part = part; + } + } + + + if (found_transid > fs_devices->latest_trans) { + fs_devices->latest_devid = devid; + fs_devices->latest_trans = found_transid; + } + if (fs_devices->lowest_devid > devid) { + fs_devices->lowest_devid = devid; + } + *fs_devices_ret = fs_devices; + return 0; +} + +int btrfs_close_devices(struct btrfs_fs_devices *fs_devices) +{ + struct btrfs_fs_devices *seed_devices; + struct btrfs_device *device; + int ret = 0; + +again: + if (!fs_devices) + return 0; + while (!list_empty(&fs_devices->devices)) { + device = list_entry(fs_devices->devices.next, + struct btrfs_device, dev_list); + list_del(&device->dev_list); + /* free the memory */ + free(device); + } + + seed_devices = fs_devices->seed; + fs_devices->seed = NULL; + if (seed_devices) { + struct btrfs_fs_devices *orig; + + orig = fs_devices; + fs_devices = seed_devices; + list_del(&orig->list); + free(orig); + goto again; + } else { + list_del(&fs_devices->list); + free(fs_devices); + } + + return ret; +} + +void btrfs_close_all_devices(void) +{ + struct btrfs_fs_devices *fs_devices; + + while (!list_empty(&fs_uuids)) { + fs_devices = list_entry(fs_uuids.next, struct btrfs_fs_devices, + list); + btrfs_close_devices(fs_devices); + } +} + +int btrfs_open_devices(struct btrfs_fs_devices *fs_devices) +{ + struct btrfs_device *device; + + list_for_each_entry(device, &fs_devices->devices, dev_list) { + if (!device->desc || !device->part) { + printf("no device found for devid %llu, skip it \n", + device->devid); + continue; + } + } + return 0; +} + +int btrfs_scan_one_device(struct blk_desc *desc, struct disk_partition *part, + struct btrfs_fs_devices **fs_devices_ret, + u64 *total_devs) +{ + struct btrfs_super_block *disk_super; + char buf[BTRFS_SUPER_INFO_SIZE]; + int ret; + u64 devid; + + disk_super = (struct btrfs_super_block *)buf; + ret = btrfs_read_dev_super(desc, part, disk_super); + if (ret < 0) + return -EIO; + devid = btrfs_stack_device_id(&disk_super->dev_item); + if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_METADUMP) + *total_devs = 1; + else + *total_devs = btrfs_super_num_devices(disk_super); + + ret = device_list_add(disk_super, devid, desc, part, fs_devices_ret); + + return ret; +} + +struct btrfs_device *btrfs_find_device(struct btrfs_fs_info *fs_info, u64 devid, + u8 *uuid, u8 *fsid) +{ + struct btrfs_device *device; + struct btrfs_fs_devices *cur_devices; + + cur_devices = fs_info->fs_devices; + while (cur_devices) { + if (!fsid || + !memcmp(cur_devices->metadata_uuid, fsid, BTRFS_FSID_SIZE)) { + device = find_device(cur_devices, devid, uuid); + if (device) + return device; + } + cur_devices = cur_devices->seed; + } + return NULL; +} + +/* + * slot == -1: SYSTEM chunk + * return -EIO on error, otherwise return 0 + */ +int btrfs_check_chunk_valid(struct btrfs_fs_info *fs_info, + struct extent_buffer *leaf, + struct btrfs_chunk *chunk, + int slot, u64 logical) +{ + u64 length; + u64 stripe_len; + u16 num_stripes; + u16 sub_stripes; + u64 type; + u32 chunk_ondisk_size; + u32 sectorsize = fs_info->sectorsize; + + /* + * Basic chunk item size check. Note that btrfs_chunk already contains + * one stripe, so no "==" check. + */ + if (slot >= 0 && + btrfs_item_size_nr(leaf, slot) < sizeof(struct btrfs_chunk)) { + error("invalid chunk item size, have %u expect [%zu, %zu)", + btrfs_item_size_nr(leaf, slot), + sizeof(struct btrfs_chunk), + BTRFS_LEAF_DATA_SIZE(fs_info)); + return -EUCLEAN; + } + length = btrfs_chunk_length(leaf, chunk); + stripe_len = btrfs_chunk_stripe_len(leaf, chunk); + num_stripes = btrfs_chunk_num_stripes(leaf, chunk); + sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk); + type = btrfs_chunk_type(leaf, chunk); + + if (num_stripes == 0) { + error("invalid num_stripes, have %u expect non-zero", + num_stripes); + return -EUCLEAN; + } + if (slot >= 0 && btrfs_chunk_item_size(num_stripes) != + btrfs_item_size_nr(leaf, slot)) { + error("invalid chunk item size, have %u expect %lu", + btrfs_item_size_nr(leaf, slot), + btrfs_chunk_item_size(num_stripes)); + return -EUCLEAN; + } + + /* + * These valid checks may be insufficient to cover every corner cases. + */ + if (!IS_ALIGNED(logical, sectorsize)) { + error("invalid chunk logical %llu", logical); + return -EIO; + } + if (btrfs_chunk_sector_size(leaf, chunk) != sectorsize) { + error("invalid chunk sectorsize %llu", + (unsigned long long)btrfs_chunk_sector_size(leaf, chunk)); + return -EIO; + } + if (!length || !IS_ALIGNED(length, sectorsize)) { + error("invalid chunk length %llu", length); + return -EIO; + } + if (stripe_len != BTRFS_STRIPE_LEN) { + error("invalid chunk stripe length: %llu", stripe_len); + return -EIO; + } + /* Check on chunk item type */ + if (slot == -1 && (type & BTRFS_BLOCK_GROUP_SYSTEM) == 0) { + error("invalid chunk type %llu", type); + return -EIO; + } + if (type & ~(BTRFS_BLOCK_GROUP_TYPE_MASK | + BTRFS_BLOCK_GROUP_PROFILE_MASK)) { + error("unrecognized chunk type: %llu", + ~(BTRFS_BLOCK_GROUP_TYPE_MASK | + BTRFS_BLOCK_GROUP_PROFILE_MASK) & type); + return -EIO; + } + if (!(type & BTRFS_BLOCK_GROUP_TYPE_MASK)) { + error("missing chunk type flag: %llu", type); + return -EIO; + } + if (!(is_power_of_2(type & BTRFS_BLOCK_GROUP_PROFILE_MASK) || + (type & BTRFS_BLOCK_GROUP_PROFILE_MASK) == 0)) { + error("conflicting chunk type detected: %llu", type); + return -EIO; + } + if ((type & BTRFS_BLOCK_GROUP_PROFILE_MASK) && + !is_power_of_2(type & BTRFS_BLOCK_GROUP_PROFILE_MASK)) { + error("conflicting chunk profile detected: %llu", type); + return -EIO; + } + + chunk_ondisk_size = btrfs_chunk_item_size(num_stripes); + /* + * Btrfs_chunk contains at least one stripe, and for sys_chunk + * it can't exceed the system chunk array size + * For normal chunk, it should match its chunk item size. + */ + if (num_stripes < 1 || + (slot == -1 && chunk_ondisk_size > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE) || + (slot >= 0 && chunk_ondisk_size > btrfs_item_size_nr(leaf, slot))) { + error("invalid num_stripes: %u", num_stripes); + return -EIO; + } + /* + * Device number check against profile + */ + if ((type & BTRFS_BLOCK_GROUP_RAID10 && (sub_stripes != 2 || + !IS_ALIGNED(num_stripes, sub_stripes))) || + (type & BTRFS_BLOCK_GROUP_RAID1 && num_stripes < 1) || + (type & BTRFS_BLOCK_GROUP_RAID1C3 && num_stripes < 3) || + (type & BTRFS_BLOCK_GROUP_RAID1C4 && num_stripes < 4) || + (type & BTRFS_BLOCK_GROUP_RAID5 && num_stripes < 2) || + (type & BTRFS_BLOCK_GROUP_RAID6 && num_stripes < 3) || + (type & BTRFS_BLOCK_GROUP_DUP && num_stripes > 2) || + ((type & BTRFS_BLOCK_GROUP_PROFILE_MASK) == 0 && + num_stripes != 1)) { + error("Invalid num_stripes:sub_stripes %u:%u for profile %llu", + num_stripes, sub_stripes, + type & BTRFS_BLOCK_GROUP_PROFILE_MASK); + return -EIO; + } + + return 0; +} + +/* + * Get stripe length from chunk item and its stripe items + * + * Caller should only call this function after validating the chunk item + * by using btrfs_check_chunk_valid(). + */ +u64 btrfs_stripe_length(struct btrfs_fs_info *fs_info, + struct extent_buffer *leaf, + struct btrfs_chunk *chunk) +{ + u64 stripe_len; + u64 chunk_len; + u32 num_stripes = btrfs_chunk_num_stripes(leaf, chunk); + u64 profile = btrfs_chunk_type(leaf, chunk) & + BTRFS_BLOCK_GROUP_PROFILE_MASK; + + chunk_len = btrfs_chunk_length(leaf, chunk); + + switch (profile) { + case 0: /* Single profile */ + case BTRFS_BLOCK_GROUP_RAID1: + case BTRFS_BLOCK_GROUP_RAID1C3: + case BTRFS_BLOCK_GROUP_RAID1C4: + case BTRFS_BLOCK_GROUP_DUP: + stripe_len = chunk_len; + break; + case BTRFS_BLOCK_GROUP_RAID0: + stripe_len = chunk_len / num_stripes; + break; + case BTRFS_BLOCK_GROUP_RAID5: + stripe_len = chunk_len / (num_stripes - 1); + break; + case BTRFS_BLOCK_GROUP_RAID6: + stripe_len = chunk_len / (num_stripes - 2); + break; + case BTRFS_BLOCK_GROUP_RAID10: + stripe_len = chunk_len / (num_stripes / + btrfs_chunk_sub_stripes(leaf, chunk)); + break; + default: + /* Invalid chunk profile found */ + BUG_ON(1); + } + return stripe_len; +} + +int btrfs_num_copies(struct btrfs_fs_info *fs_info, u64 logical, u64 len) +{ + struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree; + struct cache_extent *ce; + struct map_lookup *map; + int ret; + + ce = search_cache_extent(&map_tree->cache_tree, logical); + if (!ce) { + fprintf(stderr, "No mapping for %llu-%llu\n", + (unsigned long long)logical, + (unsigned long long)logical+len); + return 1; + } + if (ce->start > logical || ce->start + ce->size < logical) { + fprintf(stderr, "Invalid mapping for %llu-%llu, got " + "%llu-%llu\n", (unsigned long long)logical, + (unsigned long long)logical+len, + (unsigned long long)ce->start, + (unsigned long long)ce->start + ce->size); + return 1; + } + map = container_of(ce, struct map_lookup, ce); + + if (map->type & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1 | + BTRFS_BLOCK_GROUP_RAID1C3 | BTRFS_BLOCK_GROUP_RAID1C4)) + ret = map->num_stripes; + else if (map->type & BTRFS_BLOCK_GROUP_RAID10) + ret = map->sub_stripes; + else if (map->type & BTRFS_BLOCK_GROUP_RAID5) + ret = 2; + else if (map->type & BTRFS_BLOCK_GROUP_RAID6) + ret = 3; + else + ret = 1; + return ret; +} + +int btrfs_next_bg(struct btrfs_fs_info *fs_info, u64 *logical, + u64 *size, u64 type) +{ + struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree; + struct cache_extent *ce; + struct map_lookup *map; + u64 cur = *logical; + + ce = search_cache_extent(&map_tree->cache_tree, cur); + + while (ce) { + /* + * only jump to next bg if our cur is not 0 + * As the initial logical for btrfs_next_bg() is 0, and + * if we jump to next bg, we skipped a valid bg. + */ + if (cur) { + ce = next_cache_extent(ce); + if (!ce) + return -ENOENT; + } + + cur = ce->start; + map = container_of(ce, struct map_lookup, ce); + if (map->type & type) { + *logical = ce->start; + *size = ce->size; + return 0; + } + if (!cur) + ce = next_cache_extent(ce); + } + + return -ENOENT; +} + +static inline int parity_smaller(u64 a, u64 b) +{ + return a > b; +} + +/* Bubble-sort the stripe set to put the parity/syndrome stripes last */ +static void sort_parity_stripes(struct btrfs_multi_bio *bbio, u64 *raid_map) +{ + struct btrfs_bio_stripe s; + int i; + u64 l; + int again = 1; + + while (again) { + again = 0; + for (i = 0; i < bbio->num_stripes - 1; i++) { + if (parity_smaller(raid_map[i], raid_map[i+1])) { + s = bbio->stripes[i]; + l = raid_map[i]; + bbio->stripes[i] = bbio->stripes[i+1]; + raid_map[i] = raid_map[i+1]; + bbio->stripes[i+1] = s; + raid_map[i+1] = l; + again = 1; + } + } + } +} + +int __btrfs_map_block(struct btrfs_fs_info *fs_info, int rw, + u64 logical, u64 *length, u64 *type, + struct btrfs_multi_bio **multi_ret, int mirror_num, + u64 **raid_map_ret) +{ + struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree; + struct cache_extent *ce; + struct map_lookup *map; + u64 offset; + u64 stripe_offset; + u64 *raid_map = NULL; + int stripe_nr; + int stripes_allocated = 8; + int stripes_required = 1; + int stripe_index; + int i; + struct btrfs_multi_bio *multi = NULL; + + if (multi_ret && rw == READ) { + stripes_allocated = 1; + } +again: + ce = search_cache_extent(&map_tree->cache_tree, logical); + if (!ce) { + kfree(multi); + *length = (u64)-1; + return -ENOENT; + } + if (ce->start > logical) { + kfree(multi); + *length = ce->start - logical; + return -ENOENT; + } + + if (multi_ret) { + multi = kzalloc(btrfs_multi_bio_size(stripes_allocated), + GFP_NOFS); + if (!multi) + return -ENOMEM; + } + map = container_of(ce, struct map_lookup, ce); + offset = logical - ce->start; + + if (rw == WRITE) { + if (map->type & (BTRFS_BLOCK_GROUP_RAID1 | + BTRFS_BLOCK_GROUP_RAID1C3 | + BTRFS_BLOCK_GROUP_RAID1C4 | + BTRFS_BLOCK_GROUP_DUP)) { + stripes_required = map->num_stripes; + } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) { + stripes_required = map->sub_stripes; + } + } + if (map->type & (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6) + && multi_ret && ((rw & WRITE) || mirror_num > 1) && raid_map_ret) { + /* RAID[56] write or recovery. Return all stripes */ + stripes_required = map->num_stripes; + + /* Only allocate the map if we've already got a large enough multi_ret */ + if (stripes_allocated >= stripes_required) { + raid_map = kmalloc(sizeof(u64) * map->num_stripes, GFP_NOFS); + if (!raid_map) { + kfree(multi); + return -ENOMEM; + } + } + } + + /* if our multi bio struct is too small, back off and try again */ + if (multi_ret && stripes_allocated < stripes_required) { + stripes_allocated = stripes_required; + kfree(multi); + multi = NULL; + goto again; + } + stripe_nr = offset; + /* + * stripe_nr counts the total number of stripes we have to stride + * to get to this block + */ + stripe_nr = stripe_nr / map->stripe_len; + + stripe_offset = stripe_nr * map->stripe_len; + BUG_ON(offset < stripe_offset); + + /* stripe_offset is the offset of this block in its stripe*/ + stripe_offset = offset - stripe_offset; + + if (map->type & (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1 | + BTRFS_BLOCK_GROUP_RAID1C3 | BTRFS_BLOCK_GROUP_RAID1C4 | + BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6 | + BTRFS_BLOCK_GROUP_RAID10 | + BTRFS_BLOCK_GROUP_DUP)) { + /* we limit the length of each bio to what fits in a stripe */ + *length = min_t(u64, ce->size - offset, + map->stripe_len - stripe_offset); + } else { + *length = ce->size - offset; + } + + if (!multi_ret) + goto out; + + multi->num_stripes = 1; + stripe_index = 0; + if (map->type & (BTRFS_BLOCK_GROUP_RAID1 | + BTRFS_BLOCK_GROUP_RAID1C3 | + BTRFS_BLOCK_GROUP_RAID1C4)) { + if (rw == WRITE) + multi->num_stripes = map->num_stripes; + else if (mirror_num) + stripe_index = mirror_num - 1; + else + stripe_index = stripe_nr % map->num_stripes; + } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) { + int factor = map->num_stripes / map->sub_stripes; + + stripe_index = stripe_nr % factor; + stripe_index *= map->sub_stripes; + + if (rw == WRITE) + multi->num_stripes = map->sub_stripes; + else if (mirror_num) + stripe_index += mirror_num - 1; + + stripe_nr = stripe_nr / factor; + } else if (map->type & BTRFS_BLOCK_GROUP_DUP) { + if (rw == WRITE) + multi->num_stripes = map->num_stripes; + else if (mirror_num) + stripe_index = mirror_num - 1; + } else if (map->type & (BTRFS_BLOCK_GROUP_RAID5 | + BTRFS_BLOCK_GROUP_RAID6)) { + + if (raid_map) { + int rot; + u64 tmp; + u64 raid56_full_stripe_start; + u64 full_stripe_len = nr_data_stripes(map) * map->stripe_len; + + /* + * align the start of our data stripe in the logical + * address space + */ + raid56_full_stripe_start = offset / full_stripe_len; + raid56_full_stripe_start *= full_stripe_len; + + /* get the data stripe number */ + stripe_nr = raid56_full_stripe_start / map->stripe_len; + stripe_nr = stripe_nr / nr_data_stripes(map); + + /* Work out the disk rotation on this stripe-set */ + rot = stripe_nr % map->num_stripes; + + /* Fill in the logical address of each stripe */ + tmp = stripe_nr * nr_data_stripes(map); + + for (i = 0; i < nr_data_stripes(map); i++) + raid_map[(i+rot) % map->num_stripes] = + ce->start + (tmp + i) * map->stripe_len; + + raid_map[(i+rot) % map->num_stripes] = BTRFS_RAID5_P_STRIPE; + if (map->type & BTRFS_BLOCK_GROUP_RAID6) + raid_map[(i+rot+1) % map->num_stripes] = BTRFS_RAID6_Q_STRIPE; + + *length = map->stripe_len; + stripe_index = 0; + stripe_offset = 0; + multi->num_stripes = map->num_stripes; + } else { + stripe_index = stripe_nr % nr_data_stripes(map); + stripe_nr = stripe_nr / nr_data_stripes(map); + + /* + * Mirror #0 or #1 means the original data block. + * Mirror #2 is RAID5 parity block. + * Mirror #3 is RAID6 Q block. + */ + if (mirror_num > 1) + stripe_index = nr_data_stripes(map) + mirror_num - 2; + + /* We distribute the parity blocks across stripes */ + stripe_index = (stripe_nr + stripe_index) % map->num_stripes; + } + } else { + /* + * after this do_div call, stripe_nr is the number of stripes + * on this device we have to walk to find the data, and + * stripe_index is the number of our device in the stripe array + */ + stripe_index = stripe_nr % map->num_stripes; + stripe_nr = stripe_nr / map->num_stripes; + } + BUG_ON(stripe_index >= map->num_stripes); + + for (i = 0; i < multi->num_stripes; i++) { + multi->stripes[i].physical = + map->stripes[stripe_index].physical + stripe_offset + + stripe_nr * map->stripe_len; + multi->stripes[i].dev = map->stripes[stripe_index].dev; + stripe_index++; + } + *multi_ret = multi; + + if (type) + *type = map->type; + + if (raid_map) { + sort_parity_stripes(multi, raid_map); + *raid_map_ret = raid_map; + } +out: + return 0; +} + +int btrfs_map_block(struct btrfs_fs_info *fs_info, int rw, + u64 logical, u64 *length, + struct btrfs_multi_bio **multi_ret, int mirror_num, + u64 **raid_map_ret) +{ + return __btrfs_map_block(fs_info, rw, logical, length, NULL, + multi_ret, mirror_num, raid_map_ret); +} |