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|
// 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);
}
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