fs: btrfs: Crossport volumes.[ch] from btrfs-progs
This patch crossports volumes.[ch] from btrfs-progs, including:
- btrfs_map_block()
The core mechanism to map btrfs logical address to physical address.
This version includes multi-device support, along with RAID56 support.
- btrfs_scan_one_device()
This is the function to register one btrfs device to the list.
This is the main part of the multi-device btrfs assembling process.
Although we're not going to support multiple devices until U-Boot
allows us to scan one device without actually opening it.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Marek Behún <marek.behun@nic.cz>
[trini: Use %zu in a debug print to avoid warning]
Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
new file mode 100644
index 0000000..c671b53
--- /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);
+}