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btrfs-progs/volumes.c

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/*
* Copyright (C) 2007 Oracle. All rights reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License v2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public
* License along with this program; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 021110-1307, USA.
*/
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <uuid/uuid.h>
#include <fcntl.h>
#include <unistd.h>
#include "ctree.h"
#include "disk-io.h"
#include "transaction.h"
#include "print-tree.h"
#include "volumes.h"
#include "utils.h"
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);
static struct btrfs_device *__find_device(struct list_head *head, u64 devid,
u8 *uuid)
{
struct btrfs_device *dev;
struct list_head *cur;
list_for_each(cur, head) {
dev = list_entry(cur, struct btrfs_device, dev_list);
if (dev->devid == devid &&
!memcmp(dev->uuid, uuid, BTRFS_UUID_SIZE)) {
return dev;
}
}
return NULL;
}
static struct btrfs_fs_devices *find_fsid(u8 *fsid)
{
struct list_head *cur;
struct btrfs_fs_devices *fs_devices;
list_for_each(cur, &fs_uuids) {
fs_devices = list_entry(cur, struct btrfs_fs_devices, list);
if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) == 0)
return fs_devices;
}
return NULL;
}
static int device_list_add(const char *path,
struct btrfs_super_block *disk_super,
u64 devid, 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);
fs_devices = find_fsid(disk_super->fsid);
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);
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->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->fd = -1;
device->devid = devid;
device->generation = found_transid;
memcpy(device->uuid, disk_super->dev_item.uuid,
BTRFS_UUID_SIZE);
device->name = kstrdup(path, GFP_NOFS);
if (!device->name) {
kfree(device);
return -ENOMEM;
}
device->label = kstrdup(disk_super->label, GFP_NOFS);
if (!device->label) {
kfree(device->name);
kfree(device);
return -ENOMEM;
}
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->name || strcmp(device->name, path)) {
char *name = strdup(path);
if (!name)
return -ENOMEM;
kfree(device->name);
device->name = name;
}
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);
if (device->fd != -1) {
if (fsync(device->fd) == -1) {
warning("fsync on device %llu failed: %s",
device->devid, strerror(errno));
ret = -errno;
}
if (posix_fadvise(device->fd, 0, 0, POSIX_FADV_DONTNEED))
fprintf(stderr, "Warning, could not drop caches\n");
close(device->fd);
device->fd = -1;
}
device->writeable = 0;
list_del(&device->dev_list);
/* free the memory */
free(device->name);
free(device->label);
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, int flags)
{
int fd;
struct list_head *head = &fs_devices->devices;
struct list_head *cur;
struct btrfs_device *device;
int ret;
list_for_each(cur, head) {
device = list_entry(cur, struct btrfs_device, dev_list);
if (!device->name) {
printk("no name for device %llu, skip it now\n", device->devid);
continue;
}
fd = open(device->name, flags);
if (fd < 0) {
ret = -errno;
error("cannot open device '%s': %s", device->name,
strerror(errno));
goto fail;
}
if (posix_fadvise(fd, 0, 0, POSIX_FADV_DONTNEED))
fprintf(stderr, "Warning, could not drop caches\n");
if (device->devid == fs_devices->latest_devid)
fs_devices->latest_bdev = fd;
if (device->devid == fs_devices->lowest_devid)
fs_devices->lowest_bdev = fd;
device->fd = fd;
if (flags & O_RDWR)
device->writeable = 1;
}
return 0;
fail:
btrfs_close_devices(fs_devices);
return ret;
}
int btrfs_scan_one_device(int fd, const char *path,
struct btrfs_fs_devices **fs_devices_ret,
u64 *total_devs, u64 super_offset, unsigned sbflags)
{
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(fd, disk_super, super_offset, sbflags);
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(path, disk_super, devid, fs_devices_ret);
return ret;
}
/*
* find_free_dev_extent_start - find free space in the specified device
* @device: the device which we search the free space in
* @num_bytes: the size of the free space that we need
* @search_start: the position from which to begin the search
* @start: store the start of the free space.
* @len: the size of the free space. that we find, or the size
* of the max free space if we don't find suitable free space
*
* this uses a pretty simple search, the expectation is that it is
* called very infrequently and that a given device has a small number
* of extents
*
* @start is used to store the start of the free space if we find. But if we
* don't find suitable free space, it will be used to store the start position
* of the max free space.
*
* @len is used to store the size of the free space that we find.
* But if we don't find suitable free space, it is used to store the size of
* the max free space.
*/
static int find_free_dev_extent_start(struct btrfs_trans_handle *trans,
struct btrfs_device *device, u64 num_bytes,
u64 search_start, u64 *start, u64 *len)
{
struct btrfs_key key;
struct btrfs_root *root = device->dev_root;
struct btrfs_dev_extent *dev_extent;
struct btrfs_path *path;
u64 hole_size;
u64 max_hole_start;
u64 max_hole_size;
u64 extent_end;
u64 search_end = device->total_bytes;
int ret;
int slot;
struct extent_buffer *l;
u64 min_search_start;
/*
* We don't want to overwrite the superblock on the drive nor any area
* used by the boot loader (grub for example), so we make sure to start
* at an offset of at least 1MB.
*/
min_search_start = max(root->fs_info->alloc_start, (u64)SZ_1M);
search_start = max(search_start, min_search_start);
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
max_hole_start = search_start;
max_hole_size = 0;
if (search_start >= search_end) {
ret = -ENOSPC;
goto out;
}
path->reada = 2;
key.objectid = device->devid;
key.offset = search_start;
key.type = BTRFS_DEV_EXTENT_KEY;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
goto out;
if (ret > 0) {
ret = btrfs_previous_item(root, path, key.objectid, key.type);
if (ret < 0)
goto out;
}
while (1) {
l = path->nodes[0];
slot = path->slots[0];
if (slot >= btrfs_header_nritems(l)) {
ret = btrfs_next_leaf(root, path);
if (ret == 0)
continue;
if (ret < 0)
goto out;
break;
}
btrfs_item_key_to_cpu(l, &key, slot);
if (key.objectid < device->devid)
goto next;
if (key.objectid > device->devid)
break;
if (key.type != BTRFS_DEV_EXTENT_KEY)
goto next;
if (key.offset > search_start) {
hole_size = key.offset - search_start;
/*
* Have to check before we set max_hole_start, otherwise
* we could end up sending back this offset anyway.
*/
if (hole_size > max_hole_size) {
max_hole_start = search_start;
max_hole_size = hole_size;
}
/*
* If this free space is greater than which we need,
* it must be the max free space that we have found
* until now, so max_hole_start must point to the start
* of this free space and the length of this free space
* is stored in max_hole_size. Thus, we return
* max_hole_start and max_hole_size and go back to the
* caller.
*/
if (hole_size >= num_bytes) {
ret = 0;
goto out;
}
}
dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
extent_end = key.offset + btrfs_dev_extent_length(l,
dev_extent);
if (extent_end > search_start)
search_start = extent_end;
next:
path->slots[0]++;
cond_resched();
}
/*
* At this point, search_start should be the end of
* allocated dev extents, and when shrinking the device,
* search_end may be smaller than search_start.
*/
if (search_end > search_start) {
hole_size = search_end - search_start;
if (hole_size > max_hole_size) {
max_hole_start = search_start;
max_hole_size = hole_size;
}
}
/* See above. */
if (max_hole_size < num_bytes)
ret = -ENOSPC;
else
ret = 0;
out:
btrfs_free_path(path);
*start = max_hole_start;
if (len)
*len = max_hole_size;
return ret;
}
int find_free_dev_extent(struct btrfs_trans_handle *trans,
struct btrfs_device *device, u64 num_bytes,
u64 *start)
{
/* FIXME use last free of some kind */
return find_free_dev_extent_start(trans, device,
num_bytes, 0, start, NULL);
}
static int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans,
struct btrfs_device *device,
u64 chunk_tree, u64 chunk_objectid,
u64 chunk_offset,
u64 num_bytes, u64 *start, int convert)
{
int ret;
struct btrfs_path *path;
struct btrfs_root *root = device->dev_root;
struct btrfs_dev_extent *extent;
struct extent_buffer *leaf;
struct btrfs_key key;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
/*
* For convert case, just skip search free dev_extent, as caller
* is responsible to make sure it's free.
*/
if (!convert) {
ret = find_free_dev_extent(trans, device, num_bytes,
start);
if (ret)
goto err;
}
key.objectid = device->devid;
key.offset = *start;
key.type = BTRFS_DEV_EXTENT_KEY;
ret = btrfs_insert_empty_item(trans, root, path, &key,
sizeof(*extent));
BUG_ON(ret);
leaf = path->nodes[0];
extent = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_dev_extent);
btrfs_set_dev_extent_chunk_tree(leaf, extent, chunk_tree);
btrfs_set_dev_extent_chunk_objectid(leaf, extent, chunk_objectid);
btrfs_set_dev_extent_chunk_offset(leaf, extent, chunk_offset);
write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
(unsigned long)btrfs_dev_extent_chunk_tree_uuid(extent),
BTRFS_UUID_SIZE);
btrfs_set_dev_extent_length(leaf, extent, num_bytes);
btrfs_mark_buffer_dirty(leaf);
err:
btrfs_free_path(path);
return ret;
}
static int find_next_chunk(struct btrfs_root *root, u64 objectid, u64 *offset)
{
struct btrfs_path *path;
int ret;
struct btrfs_key key;
struct btrfs_chunk *chunk;
struct btrfs_key found_key;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
key.objectid = objectid;
key.offset = (u64)-1;
key.type = BTRFS_CHUNK_ITEM_KEY;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
goto error;
BUG_ON(ret == 0);
ret = btrfs_previous_item(root, path, 0, BTRFS_CHUNK_ITEM_KEY);
if (ret) {
*offset = 0;
} else {
btrfs_item_key_to_cpu(path->nodes[0], &found_key,
path->slots[0]);
if (found_key.objectid != objectid)
*offset = 0;
else {
chunk = btrfs_item_ptr(path->nodes[0], path->slots[0],
struct btrfs_chunk);
*offset = found_key.offset +
btrfs_chunk_length(path->nodes[0], chunk);
}
}
ret = 0;
error:
btrfs_free_path(path);
return ret;
}
static int find_next_devid(struct btrfs_root *root, struct btrfs_path *path,
u64 *objectid)
{
int ret;
struct btrfs_key key;
struct btrfs_key found_key;
key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
key.type = BTRFS_DEV_ITEM_KEY;
key.offset = (u64)-1;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
goto error;
BUG_ON(ret == 0);
ret = btrfs_previous_item(root, path, BTRFS_DEV_ITEMS_OBJECTID,
BTRFS_DEV_ITEM_KEY);
if (ret) {
*objectid = 1;
} else {
btrfs_item_key_to_cpu(path->nodes[0], &found_key,
path->slots[0]);
*objectid = found_key.offset + 1;
}
ret = 0;
error:
btrfs_release_path(path);
return ret;
}
/*
* the device information is stored in the chunk root
* the btrfs_device struct should be fully filled in
*/
int btrfs_add_device(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_device *device)
{
int ret;
struct btrfs_path *path;
struct btrfs_dev_item *dev_item;
struct extent_buffer *leaf;
struct btrfs_key key;
unsigned long ptr;
u64 free_devid = 0;
root = root->fs_info->chunk_root;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
ret = find_next_devid(root, path, &free_devid);
if (ret)
goto out;
key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
key.type = BTRFS_DEV_ITEM_KEY;
key.offset = free_devid;
ret = btrfs_insert_empty_item(trans, root, path, &key,
sizeof(*dev_item));
if (ret)
goto out;
leaf = path->nodes[0];
dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
device->devid = free_devid;
btrfs_set_device_id(leaf, dev_item, device->devid);
btrfs_set_device_generation(leaf, dev_item, 0);
btrfs_set_device_type(leaf, dev_item, device->type);
btrfs_set_device_io_align(leaf, dev_item, device->io_align);
btrfs_set_device_io_width(leaf, dev_item, device->io_width);
btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
btrfs_set_device_total_bytes(leaf, dev_item, device->total_bytes);
btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
btrfs_set_device_group(leaf, dev_item, 0);
btrfs_set_device_seek_speed(leaf, dev_item, 0);
btrfs_set_device_bandwidth(leaf, dev_item, 0);
btrfs_set_device_start_offset(leaf, dev_item, 0);
ptr = (unsigned long)btrfs_device_uuid(dev_item);
write_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
ptr = (unsigned long)btrfs_device_fsid(dev_item);
write_extent_buffer(leaf, root->fs_info->fsid, ptr, BTRFS_UUID_SIZE);
btrfs_mark_buffer_dirty(leaf);
ret = 0;
out:
btrfs_free_path(path);
return ret;
}
int btrfs_update_device(struct btrfs_trans_handle *trans,
struct btrfs_device *device)
{
int ret;
struct btrfs_path *path;
struct btrfs_root *root;
struct btrfs_dev_item *dev_item;
struct extent_buffer *leaf;
struct btrfs_key key;
root = device->dev_root->fs_info->chunk_root;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
key.type = BTRFS_DEV_ITEM_KEY;
key.offset = device->devid;
ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
if (ret < 0)
goto out;
if (ret > 0) {
ret = -ENOENT;
goto out;
}
leaf = path->nodes[0];
dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
btrfs_set_device_id(leaf, dev_item, device->devid);
btrfs_set_device_type(leaf, dev_item, device->type);
btrfs_set_device_io_align(leaf, dev_item, device->io_align);
btrfs_set_device_io_width(leaf, dev_item, device->io_width);
btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
btrfs_set_device_total_bytes(leaf, dev_item, device->total_bytes);
btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
btrfs_mark_buffer_dirty(leaf);
out:
btrfs_free_path(path);
return ret;
}
int btrfs_add_system_chunk(struct btrfs_root *root,
struct btrfs_key *key,
struct btrfs_chunk *chunk, int item_size)
{
struct btrfs_super_block *super_copy = root->fs_info->super_copy;
struct btrfs_disk_key disk_key;
u32 array_size;
u8 *ptr;
array_size = btrfs_super_sys_array_size(super_copy);
if (array_size + item_size + sizeof(disk_key)
> BTRFS_SYSTEM_CHUNK_ARRAY_SIZE)
return -EFBIG;
ptr = super_copy->sys_chunk_array + array_size;
btrfs_cpu_key_to_disk(&disk_key, key);
memcpy(ptr, &disk_key, sizeof(disk_key));
ptr += sizeof(disk_key);
memcpy(ptr, chunk, item_size);
item_size += sizeof(disk_key);
btrfs_set_super_sys_array_size(super_copy, array_size + item_size);
return 0;
}
static u64 chunk_bytes_by_type(u64 type, u64 calc_size, int num_stripes,
int sub_stripes)
{
if (type & (BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_DUP))
return calc_size;
else if (type & BTRFS_BLOCK_GROUP_RAID10)
return calc_size * (num_stripes / sub_stripes);
else if (type & BTRFS_BLOCK_GROUP_RAID5)
return calc_size * (num_stripes - 1);
else if (type & BTRFS_BLOCK_GROUP_RAID6)
return calc_size * (num_stripes - 2);
else
return calc_size * num_stripes;
}
static u32 find_raid56_stripe_len(u32 data_devices, u32 dev_stripe_target)
{
/* TODO, add a way to store the preferred stripe size */
return BTRFS_STRIPE_LEN;
}
/*
* btrfs_device_avail_bytes - count bytes available for alloc_chunk
*
* It is not equal to "device->total_bytes - device->bytes_used".
* We do not allocate any chunk in 1M at beginning of device, and not
* allowed to allocate any chunk before alloc_start if it is specified.
* So search holes from max(1M, alloc_start) to device->total_bytes.
*/
static int btrfs_device_avail_bytes(struct btrfs_trans_handle *trans,
struct btrfs_device *device,
u64 *avail_bytes)
{
struct btrfs_path *path;
struct btrfs_root *root = device->dev_root;
struct btrfs_key key;
struct btrfs_dev_extent *dev_extent = NULL;
struct extent_buffer *l;
u64 search_start = root->fs_info->alloc_start;
u64 search_end = device->total_bytes;
u64 extent_end = 0;
u64 free_bytes = 0;
int ret;
int slot = 0;
search_start = max(BTRFS_BLOCK_RESERVED_1M_FOR_SUPER, search_start);
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
key.objectid = device->devid;
key.offset = root->fs_info->alloc_start;
key.type = BTRFS_DEV_EXTENT_KEY;
path->reada = 2;
ret = btrfs_search_slot(trans, root, &key, path, 0, 0);
if (ret < 0)
goto error;
ret = btrfs_previous_item(root, path, 0, key.type);
if (ret < 0)
goto error;
while (1) {
l = path->nodes[0];
slot = path->slots[0];
if (slot >= btrfs_header_nritems(l)) {
ret = btrfs_next_leaf(root, path);
if (ret == 0)
continue;
if (ret < 0)
goto error;
break;
}
btrfs_item_key_to_cpu(l, &key, slot);
if (key.objectid < device->devid)
goto next;
if (key.objectid > device->devid)
break;
if (key.type != BTRFS_DEV_EXTENT_KEY)
goto next;
if (key.offset > search_end)
break;
if (key.offset > search_start)
free_bytes += key.offset - search_start;
dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
extent_end = key.offset + btrfs_dev_extent_length(l,
dev_extent);
if (extent_end > search_start)
search_start = extent_end;
if (search_start > search_end)
break;
next:
path->slots[0]++;
cond_resched();
}
if (search_start < search_end)
free_bytes += search_end - search_start;
*avail_bytes = free_bytes;
ret = 0;
error:
btrfs_free_path(path);
return ret;
}
#define BTRFS_MAX_DEVS(r) ((BTRFS_LEAF_DATA_SIZE(r) \
- sizeof(struct btrfs_item) \
- sizeof(struct btrfs_chunk)) \
/ sizeof(struct btrfs_stripe) + 1)
#define BTRFS_MAX_DEVS_SYS_CHUNK ((BTRFS_SYSTEM_CHUNK_ARRAY_SIZE \
- 2 * sizeof(struct btrfs_disk_key) \
- 2 * sizeof(struct btrfs_chunk)) \
/ sizeof(struct btrfs_stripe) + 1)
int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
struct btrfs_root *extent_root, u64 *start,
u64 *num_bytes, u64 type)
{
u64 dev_offset;
struct btrfs_fs_info *info = extent_root->fs_info;
struct btrfs_root *chunk_root = info->chunk_root;
struct btrfs_stripe *stripes;
struct btrfs_device *device = NULL;
struct btrfs_chunk *chunk;
struct list_head private_devs;
struct list_head *dev_list = &info->fs_devices->devices;
struct list_head *cur;
struct map_lookup *map;
int min_stripe_size = SZ_1M;
u64 calc_size = SZ_8M;
u64 min_free;
u64 max_chunk_size = 4 * calc_size;
u64 avail = 0;
u64 max_avail = 0;
u64 percent_max;
int num_stripes = 1;
int max_stripes = 0;
int min_stripes = 1;
int sub_stripes = 0;
int looped = 0;
int ret;
int index;
int stripe_len = BTRFS_STRIPE_LEN;
struct btrfs_key key;
u64 offset;
if (list_empty(dev_list)) {
return -ENOSPC;
}
if (type & (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1 |
BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6 |
BTRFS_BLOCK_GROUP_RAID10 |
BTRFS_BLOCK_GROUP_DUP)) {
if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
calc_size = SZ_8M;
max_chunk_size = calc_size * 2;
min_stripe_size = SZ_1M;
max_stripes = BTRFS_MAX_DEVS_SYS_CHUNK;
} else if (type & BTRFS_BLOCK_GROUP_DATA) {
calc_size = SZ_1G;
max_chunk_size = 10 * calc_size;
min_stripe_size = SZ_64M;
max_stripes = BTRFS_MAX_DEVS(chunk_root);
} else if (type & BTRFS_BLOCK_GROUP_METADATA) {
calc_size = SZ_1G;
max_chunk_size = 4 * calc_size;
min_stripe_size = SZ_32M;
max_stripes = BTRFS_MAX_DEVS(chunk_root);
}
}
if (type & BTRFS_BLOCK_GROUP_RAID1) {
num_stripes = min_t(u64, 2,
btrfs_super_num_devices(info->super_copy));
if (num_stripes < 2)
return -ENOSPC;
min_stripes = 2;
}
if (type & BTRFS_BLOCK_GROUP_DUP) {
num_stripes = 2;
min_stripes = 2;
}
if (type & (BTRFS_BLOCK_GROUP_RAID0)) {
num_stripes = btrfs_super_num_devices(info->super_copy);
if (num_stripes > max_stripes)
num_stripes = max_stripes;
min_stripes = 2;
}
if (type & (BTRFS_BLOCK_GROUP_RAID10)) {
num_stripes = btrfs_super_num_devices(info->super_copy);
if (num_stripes > max_stripes)
num_stripes = max_stripes;
if (num_stripes < 4)
return -ENOSPC;
num_stripes &= ~(u32)1;
sub_stripes = 2;
min_stripes = 4;
}
if (type & (BTRFS_BLOCK_GROUP_RAID5)) {
num_stripes = btrfs_super_num_devices(info->super_copy);
if (num_stripes > max_stripes)
num_stripes = max_stripes;
if (num_stripes < 2)
return -ENOSPC;
min_stripes = 2;
stripe_len = find_raid56_stripe_len(num_stripes - 1,
btrfs_super_stripesize(info->super_copy));
}
if (type & (BTRFS_BLOCK_GROUP_RAID6)) {
num_stripes = btrfs_super_num_devices(info->super_copy);
if (num_stripes > max_stripes)
num_stripes = max_stripes;
if (num_stripes < 3)
return -ENOSPC;
min_stripes = 3;
stripe_len = find_raid56_stripe_len(num_stripes - 2,
btrfs_super_stripesize(info->super_copy));
}
/* we don't want a chunk larger than 10% of the FS */
percent_max = div_factor(btrfs_super_total_bytes(info->super_copy), 1);
max_chunk_size = min(percent_max, max_chunk_size);
again:
if (chunk_bytes_by_type(type, calc_size, num_stripes, sub_stripes) >
max_chunk_size) {
calc_size = max_chunk_size;
calc_size /= num_stripes;
calc_size /= stripe_len;
calc_size *= stripe_len;
}
/* we don't want tiny stripes */
calc_size = max_t(u64, calc_size, min_stripe_size);
calc_size /= stripe_len;
calc_size *= stripe_len;
INIT_LIST_HEAD(&private_devs);
cur = dev_list->next;
index = 0;
if (type & BTRFS_BLOCK_GROUP_DUP)
min_free = calc_size * 2;
else
min_free = calc_size;
/* build a private list of devices we will allocate from */
while(index < num_stripes) {
device = list_entry(cur, struct btrfs_device, dev_list);
ret = btrfs_device_avail_bytes(trans, device, &avail);
if (ret)
return ret;
cur = cur->next;
if (avail >= min_free) {
list_move_tail(&device->dev_list, &private_devs);
index++;
if (type & BTRFS_BLOCK_GROUP_DUP)
index++;
} else if (avail > max_avail)
max_avail = avail;
if (cur == dev_list)
break;
}
if (index < num_stripes) {
list_splice(&private_devs, dev_list);
if (index >= min_stripes) {
num_stripes = index;
if (type & (BTRFS_BLOCK_GROUP_RAID10)) {
num_stripes /= sub_stripes;
num_stripes *= sub_stripes;
}
looped = 1;
goto again;
}
if (!looped && max_avail > 0) {
looped = 1;
calc_size = max_avail;
goto again;
}
return -ENOSPC;
}
ret = find_next_chunk(chunk_root, BTRFS_FIRST_CHUNK_TREE_OBJECTID,
&offset);
if (ret)
return ret;
key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
key.type = BTRFS_CHUNK_ITEM_KEY;
key.offset = offset;
chunk = kmalloc(btrfs_chunk_item_size(num_stripes), GFP_NOFS);
if (!chunk)
return -ENOMEM;
map = kmalloc(btrfs_map_lookup_size(num_stripes), GFP_NOFS);
if (!map) {
kfree(chunk);
return -ENOMEM;
}
stripes = &chunk->stripe;
*num_bytes = chunk_bytes_by_type(type, calc_size,
num_stripes, sub_stripes);
index = 0;
while(index < num_stripes) {
struct btrfs_stripe *stripe;
BUG_ON(list_empty(&private_devs));
cur = private_devs.next;
device = list_entry(cur, struct btrfs_device, dev_list);
/* loop over this device again if we're doing a dup group */
if (!(type & BTRFS_BLOCK_GROUP_DUP) ||
(index == num_stripes - 1))
list_move_tail(&device->dev_list, dev_list);
ret = btrfs_alloc_dev_extent(trans, device,
info->chunk_root->root_key.objectid,
BTRFS_FIRST_CHUNK_TREE_OBJECTID, key.offset,
calc_size, &dev_offset, 0);
BUG_ON(ret);
device->bytes_used += calc_size;
ret = btrfs_update_device(trans, device);
BUG_ON(ret);
map->stripes[index].dev = device;
map->stripes[index].physical = dev_offset;
stripe = stripes + index;
btrfs_set_stack_stripe_devid(stripe, device->devid);
btrfs_set_stack_stripe_offset(stripe, dev_offset);
memcpy(stripe->dev_uuid, device->uuid, BTRFS_UUID_SIZE);
index++;
}
BUG_ON(!list_empty(&private_devs));
/* key was set above */
btrfs_set_stack_chunk_length(chunk, *num_bytes);
btrfs_set_stack_chunk_owner(chunk, extent_root->root_key.objectid);
btrfs_set_stack_chunk_stripe_len(chunk, stripe_len);
btrfs_set_stack_chunk_type(chunk, type);
btrfs_set_stack_chunk_num_stripes(chunk, num_stripes);
btrfs_set_stack_chunk_io_align(chunk, stripe_len);
btrfs_set_stack_chunk_io_width(chunk, stripe_len);
btrfs_set_stack_chunk_sector_size(chunk, extent_root->sectorsize);
btrfs_set_stack_chunk_sub_stripes(chunk, sub_stripes);
map->sector_size = extent_root->sectorsize;
map->stripe_len = stripe_len;
map->io_align = stripe_len;
map->io_width = stripe_len;
map->type = type;
map->num_stripes = num_stripes;
map->sub_stripes = sub_stripes;
ret = btrfs_insert_item(trans, chunk_root, &key, chunk,
btrfs_chunk_item_size(num_stripes));
BUG_ON(ret);
*start = key.offset;;
map->ce.start = key.offset;
map->ce.size = *num_bytes;
ret = insert_cache_extent(&info->mapping_tree.cache_tree, &map->ce);
BUG_ON(ret);
if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
ret = btrfs_add_system_chunk(chunk_root, &key,
chunk, btrfs_chunk_item_size(num_stripes));
BUG_ON(ret);
}
kfree(chunk);
return ret;
}
/*
* Alloc a DATA chunk with SINGLE profile.
*
* If 'convert' is set, it will alloc a chunk with 1:1 mapping
* (btrfs logical bytenr == on-disk bytenr)
* For that case, caller must make sure the chunk and dev_extent are not
* occupied.
*/
int btrfs_alloc_data_chunk(struct btrfs_trans_handle *trans,
struct btrfs_root *extent_root, u64 *start,
u64 num_bytes, u64 type, int convert)
{
u64 dev_offset;
struct btrfs_fs_info *info = extent_root->fs_info;
struct btrfs_root *chunk_root = info->chunk_root;
struct btrfs_stripe *stripes;
struct btrfs_device *device = NULL;
struct btrfs_chunk *chunk;
struct list_head *dev_list = &info->fs_devices->devices;
struct list_head *cur;
struct map_lookup *map;
u64 calc_size = SZ_8M;
int num_stripes = 1;
int sub_stripes = 0;
int ret;
int index;
int stripe_len = BTRFS_STRIPE_LEN;
struct btrfs_key key;
key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
key.type = BTRFS_CHUNK_ITEM_KEY;
if (convert) {
if (*start != round_down(*start, extent_root->sectorsize)) {
error("DATA chunk start not sectorsize aligned: %llu",
(unsigned long long)*start);
return -EINVAL;
}
key.offset = *start;
dev_offset = *start;
} else {
u64 tmp;
ret = find_next_chunk(chunk_root,
BTRFS_FIRST_CHUNK_TREE_OBJECTID,
&tmp);
key.offset = tmp;
if (ret)
return ret;
}
chunk = kmalloc(btrfs_chunk_item_size(num_stripes), GFP_NOFS);
if (!chunk)
return -ENOMEM;
map = kmalloc(btrfs_map_lookup_size(num_stripes), GFP_NOFS);
if (!map) {
kfree(chunk);
return -ENOMEM;
}
stripes = &chunk->stripe;
calc_size = num_bytes;
index = 0;
cur = dev_list->next;
device = list_entry(cur, struct btrfs_device, dev_list);
while (index < num_stripes) {
struct btrfs_stripe *stripe;
ret = btrfs_alloc_dev_extent(trans, device,
info->chunk_root->root_key.objectid,
BTRFS_FIRST_CHUNK_TREE_OBJECTID, key.offset,
calc_size, &dev_offset, convert);
BUG_ON(ret);
device->bytes_used += calc_size;
ret = btrfs_update_device(trans, device);
BUG_ON(ret);
map->stripes[index].dev = device;
map->stripes[index].physical = dev_offset;
stripe = stripes + index;
btrfs_set_stack_stripe_devid(stripe, device->devid);
btrfs_set_stack_stripe_offset(stripe, dev_offset);
memcpy(stripe->dev_uuid, device->uuid, BTRFS_UUID_SIZE);
index++;
}
/* key was set above */
btrfs_set_stack_chunk_length(chunk, num_bytes);
btrfs_set_stack_chunk_owner(chunk, extent_root->root_key.objectid);
btrfs_set_stack_chunk_stripe_len(chunk, stripe_len);
btrfs_set_stack_chunk_type(chunk, type);
btrfs_set_stack_chunk_num_stripes(chunk, num_stripes);
btrfs_set_stack_chunk_io_align(chunk, stripe_len);
btrfs_set_stack_chunk_io_width(chunk, stripe_len);
btrfs_set_stack_chunk_sector_size(chunk, extent_root->sectorsize);
btrfs_set_stack_chunk_sub_stripes(chunk, sub_stripes);
map->sector_size = extent_root->sectorsize;
map->stripe_len = stripe_len;
map->io_align = stripe_len;
map->io_width = stripe_len;
map->type = type;
map->num_stripes = num_stripes;
map->sub_stripes = sub_stripes;
ret = btrfs_insert_item(trans, chunk_root, &key, chunk,
btrfs_chunk_item_size(num_stripes));
BUG_ON(ret);
if (!convert)
*start = key.offset;
map->ce.start = key.offset;
map->ce.size = num_bytes;
ret = insert_cache_extent(&info->mapping_tree.cache_tree, &map->ce);
BUG_ON(ret);
kfree(chunk);
return ret;
}
int btrfs_num_copies(struct btrfs_mapping_tree *map_tree, u64 logical, u64 len)
{
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))
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_mapping_tree *map_tree, u64 *logical,
u64 *size, u64 type)
{
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;
}
}
return -ENOENT;
}
int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree,
u64 chunk_start, u64 physical, u64 devid,
u64 **logical, int *naddrs, int *stripe_len)
{
struct cache_extent *ce;
struct map_lookup *map;
u64 *buf;
u64 bytenr;
u64 length;
u64 stripe_nr;
u64 rmap_len;
int i, j, nr = 0;
ce = search_cache_extent(&map_tree->cache_tree, chunk_start);
BUG_ON(!ce);
map = container_of(ce, struct map_lookup, ce);
length = ce->size;
rmap_len = map->stripe_len;
if (map->type & BTRFS_BLOCK_GROUP_RAID10)
length = ce->size / (map->num_stripes / map->sub_stripes);
else if (map->type & BTRFS_BLOCK_GROUP_RAID0)
length = ce->size / map->num_stripes;
else if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
BTRFS_BLOCK_GROUP_RAID6)) {
length = ce->size / nr_data_stripes(map);
rmap_len = map->stripe_len * nr_data_stripes(map);
}
buf = kzalloc(sizeof(u64) * map->num_stripes, GFP_NOFS);
for (i = 0; i < map->num_stripes; i++) {
if (devid && map->stripes[i].dev->devid != devid)
continue;
if (map->stripes[i].physical > physical ||
map->stripes[i].physical + length <= physical)
continue;
stripe_nr = (physical - map->stripes[i].physical) /
map->stripe_len;
if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
stripe_nr = (stripe_nr * map->num_stripes + i) /
map->sub_stripes;
} else if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
stripe_nr = stripe_nr * map->num_stripes + i;
} /* else if RAID[56], multiply by nr_data_stripes().
* Alternatively, just use rmap_len below instead of
* map->stripe_len */
bytenr = ce->start + stripe_nr * rmap_len;
for (j = 0; j < nr; j++) {
if (buf[j] == bytenr)
break;
}
if (j == nr)
buf[nr++] = bytenr;
}
*logical = buf;
*naddrs = nr;
*stripe_len = rmap_len;
return 0;
}
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_mapping_tree *map_tree, int rw,
u64 logical, u64 *length,
struct btrfs_multi_bio **multi_ret, int mirror_num,
u64 **raid_map_ret)
{
return __btrfs_map_block(map_tree, rw, logical, length, NULL,
multi_ret, mirror_num, raid_map_ret);
}
int __btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
u64 logical, u64 *length, u64 *type,
struct btrfs_multi_bio **multi_ret, int mirror_num,
u64 **raid_map_ret)
{
struct cache_extent *ce;
struct map_lookup *map;
u64 offset;
u64 stripe_offset;
u64 stripe_nr;
u64 *raid_map = NULL;
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_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_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) {
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;
}
struct btrfs_device *btrfs_find_device(struct btrfs_root *root, u64 devid,
u8 *uuid, u8 *fsid)
{
struct btrfs_device *device;
struct btrfs_fs_devices *cur_devices;
cur_devices = root->fs_info->fs_devices;
while (cur_devices) {
if (!fsid ||
(!memcmp(cur_devices->fsid, fsid, BTRFS_UUID_SIZE) ||
root->fs_info->ignore_fsid_mismatch)) {
device = __find_device(&cur_devices->devices,
devid, uuid);
if (device)
return device;
}
cur_devices = cur_devices->seed;
}
return NULL;
}
struct btrfs_device *
btrfs_find_device_by_devid(struct btrfs_fs_devices *fs_devices,
u64 devid, int instance)
{
struct list_head *head = &fs_devices->devices;
struct btrfs_device *dev;
int num_found = 0;
list_for_each_entry(dev, head, dev_list) {
if (dev->devid == devid && num_found++ == instance)
return dev;
}
return NULL;
}
int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset)
{
struct cache_extent *ce;
struct map_lookup *map;
struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
int readonly = 0;
int i;
/*
* During chunk recovering, we may fail to find block group's
* corresponding chunk, we will rebuild it later
*/
ce = search_cache_extent(&map_tree->cache_tree, chunk_offset);
if (!root->fs_info->is_chunk_recover)
BUG_ON(!ce);
else
return 0;
map = container_of(ce, struct map_lookup, ce);
for (i = 0; i < map->num_stripes; i++) {
if (!map->stripes[i].dev->writeable) {
readonly = 1;
break;
}
}
return readonly;
}
static struct btrfs_device *fill_missing_device(u64 devid)
{
struct btrfs_device *device;
device = kzalloc(sizeof(*device), GFP_NOFS);
device->devid = devid;
device->fd = -1;
return device;
}
/*
* slot == -1: SYSTEM chunk
* return -EIO on error, otherwise return 0
*/
int btrfs_check_chunk_valid(struct btrfs_root *root,
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;
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);
/*
* These valid checks may be insufficient to cover every corner cases.
*/
if (!IS_ALIGNED(logical, root->sectorsize)) {
error("invalid chunk logical %llu", logical);
return -EIO;
}
if (btrfs_chunk_sector_size(leaf, chunk) != root->sectorsize) {
error("invalid chunk sectorsize %llu",
(unsigned long long)btrfs_chunk_sector_size(leaf, chunk));
return -EIO;
}
if (!length || !IS_ALIGNED(length, root->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;
}
/*
* 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 && sizeof(struct btrfs_stripe) * num_stripes >
BTRFS_SYSTEM_CHUNK_ARRAY_SIZE) ||
(slot >= 0 && sizeof(struct btrfs_stripe) * (num_stripes - 1) >
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 == 0) ||
(type & BTRFS_BLOCK_GROUP_RAID1 && num_stripes < 1) ||
(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;
}
/*
* Slot is used to verify the chunk item is valid
*
* For sys chunk in superblock, pass -1 to indicate sys chunk.
*/
static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
struct extent_buffer *leaf,
struct btrfs_chunk *chunk, int slot)
{
struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
struct map_lookup *map;
struct cache_extent *ce;
u64 logical;
u64 length;
u64 devid;
u8 uuid[BTRFS_UUID_SIZE];
int num_stripes;
int ret;
int i;
logical = key->offset;
length = btrfs_chunk_length(leaf, chunk);
num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
/* Validation check */
ret = btrfs_check_chunk_valid(root, leaf, chunk, slot, logical);
if (ret) {
error("%s checksums match, but it has an invalid chunk, %s",
(slot == -1) ? "Superblock" : "Metadata",
(slot == -1) ? "try btrfsck --repair -s <superblock> ie, 0,1,2" : "");
return ret;
}
ce = search_cache_extent(&map_tree->cache_tree, logical);
/* already mapped? */
if (ce && ce->start <= logical && ce->start + ce->size > logical) {
return 0;
}
map = kmalloc(btrfs_map_lookup_size(num_stripes), GFP_NOFS);
if (!map)
return -ENOMEM;
map->ce.start = logical;
map->ce.size = length;
map->num_stripes = num_stripes;
map->io_width = btrfs_chunk_io_width(leaf, chunk);
map->io_align = btrfs_chunk_io_align(leaf, chunk);
map->sector_size = btrfs_chunk_sector_size(leaf, chunk);
map->stripe_len = btrfs_chunk_stripe_len(leaf, chunk);
map->type = btrfs_chunk_type(leaf, chunk);
map->sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk);
for (i = 0; i < num_stripes; i++) {
map->stripes[i].physical =
btrfs_stripe_offset_nr(leaf, chunk, i);
devid = btrfs_stripe_devid_nr(leaf, chunk, i);
read_extent_buffer(leaf, uuid, (unsigned long)
btrfs_stripe_dev_uuid_nr(chunk, i),
BTRFS_UUID_SIZE);
map->stripes[i].dev = btrfs_find_device(root, devid, uuid,
NULL);
if (!map->stripes[i].dev) {
map->stripes[i].dev = fill_missing_device(devid);
printf("warning, device %llu is missing\n",
(unsigned long long)devid);
list_add(&map->stripes[i].dev->dev_list,
&root->fs_info->fs_devices->devices);
}
}
ret = insert_cache_extent(&map_tree->cache_tree, &map->ce);
BUG_ON(ret);
return 0;
}
static int fill_device_from_item(struct extent_buffer *leaf,
struct btrfs_dev_item *dev_item,
struct btrfs_device *device)
{
unsigned long ptr;
device->devid = btrfs_device_id(leaf, dev_item);
device->total_bytes = btrfs_device_total_bytes(leaf, dev_item);
device->bytes_used = btrfs_device_bytes_used(leaf, dev_item);
device->type = btrfs_device_type(leaf, dev_item);
device->io_align = btrfs_device_io_align(leaf, dev_item);
device->io_width = btrfs_device_io_width(leaf, dev_item);
device->sector_size = btrfs_device_sector_size(leaf, dev_item);
ptr = (unsigned long)btrfs_device_uuid(dev_item);
read_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
return 0;
}
static int open_seed_devices(struct btrfs_root *root, u8 *fsid)
{
struct btrfs_fs_devices *fs_devices;
int ret;
fs_devices = root->fs_info->fs_devices->seed;
while (fs_devices) {
if (!memcmp(fs_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
ret = 0;
goto out;
}
fs_devices = fs_devices->seed;
}
fs_devices = find_fsid(fsid);
if (!fs_devices) {
/* missing all seed devices */
fs_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
if (!fs_devices) {
ret = -ENOMEM;
goto out;
}
INIT_LIST_HEAD(&fs_devices->devices);
list_add(&fs_devices->list, &fs_uuids);
memcpy(fs_devices->fsid, fsid, BTRFS_FSID_SIZE);
}
ret = btrfs_open_devices(fs_devices, O_RDONLY);
if (ret)
goto out;
fs_devices->seed = root->fs_info->fs_devices->seed;
root->fs_info->fs_devices->seed = fs_devices;
out:
return ret;
}
static int read_one_dev(struct btrfs_root *root,
struct extent_buffer *leaf,
struct btrfs_dev_item *dev_item)
{
struct btrfs_device *device;
u64 devid;
int ret = 0;
u8 fs_uuid[BTRFS_UUID_SIZE];
u8 dev_uuid[BTRFS_UUID_SIZE];
devid = btrfs_device_id(leaf, dev_item);
read_extent_buffer(leaf, dev_uuid,
(unsigned long)btrfs_device_uuid(dev_item),
BTRFS_UUID_SIZE);
read_extent_buffer(leaf, fs_uuid,
(unsigned long)btrfs_device_fsid(dev_item),
BTRFS_UUID_SIZE);
if (memcmp(fs_uuid, root->fs_info->fsid, BTRFS_UUID_SIZE)) {
ret = open_seed_devices(root, fs_uuid);
if (ret)
return ret;
}
device = btrfs_find_device(root, devid, dev_uuid, fs_uuid);
if (!device) {
device = kzalloc(sizeof(*device), GFP_NOFS);
if (!device)
return -ENOMEM;
device->fd = -1;
list_add(&device->dev_list,
&root->fs_info->fs_devices->devices);
}
fill_device_from_item(leaf, dev_item, device);
device->dev_root = root->fs_info->dev_root;
return ret;
}
int btrfs_read_sys_array(struct btrfs_root *root)
{
struct btrfs_super_block *super_copy = root->fs_info->super_copy;
struct extent_buffer *sb;
struct btrfs_disk_key *disk_key;
struct btrfs_chunk *chunk;
u8 *array_ptr;
unsigned long sb_array_offset;
int ret = 0;
u32 num_stripes;
u32 array_size;
u32 len = 0;
u32 cur_offset;
struct btrfs_key key;
sb = btrfs_find_create_tree_block(root->fs_info,
BTRFS_SUPER_INFO_OFFSET,
BTRFS_SUPER_INFO_SIZE);
if (!sb)
return -ENOMEM;
btrfs_set_buffer_uptodate(sb);
write_extent_buffer(sb, super_copy, 0, sizeof(*super_copy));
array_size = btrfs_super_sys_array_size(super_copy);
array_ptr = super_copy->sys_chunk_array;
sb_array_offset = offsetof(struct btrfs_super_block, sys_chunk_array);
cur_offset = 0;
while (cur_offset < array_size) {
disk_key = (struct btrfs_disk_key *)array_ptr;
len = sizeof(*disk_key);
if (cur_offset + len > array_size)
goto out_short_read;
btrfs_disk_key_to_cpu(&key, disk_key);
array_ptr += len;
sb_array_offset += len;
cur_offset += len;
if (key.type == BTRFS_CHUNK_ITEM_KEY) {
chunk = (struct btrfs_chunk *)sb_array_offset;
/*
* At least one btrfs_chunk with one stripe must be
* present, exact stripe count check comes afterwards
*/
len = btrfs_chunk_item_size(1);
if (cur_offset + len > array_size)
goto out_short_read;
num_stripes = btrfs_chunk_num_stripes(sb, chunk);
if (!num_stripes) {
printk(
"ERROR: invalid number of stripes %u in sys_array at offset %u\n",
num_stripes, cur_offset);
ret = -EIO;
break;
}
len = btrfs_chunk_item_size(num_stripes);
if (cur_offset + len > array_size)
goto out_short_read;
ret = read_one_chunk(root, &key, sb, chunk, -1);
if (ret)
break;
} else {
printk(
"ERROR: unexpected item type %u in sys_array at offset %u\n",
(u32)key.type, cur_offset);
ret = -EIO;
break;
}
array_ptr += len;
sb_array_offset += len;
cur_offset += len;
}
free_extent_buffer(sb);
return ret;
out_short_read:
printk("ERROR: sys_array too short to read %u bytes at offset %u\n",
len, cur_offset);
free_extent_buffer(sb);
return -EIO;
}
int btrfs_read_chunk_tree(struct btrfs_root *root)
{
struct btrfs_path *path;
struct extent_buffer *leaf;
struct btrfs_key key;
struct btrfs_key found_key;
int ret;
int slot;
root = root->fs_info->chunk_root;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
/*
* Read all device items, and then all the chunk items. All
* device items are found before any chunk item (their object id
* is smaller than the lowest possible object id for a chunk
* item - BTRFS_FIRST_CHUNK_TREE_OBJECTID).
*/
key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
key.offset = 0;
key.type = 0;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
goto error;
while(1) {
leaf = path->nodes[0];
slot = path->slots[0];
if (slot >= btrfs_header_nritems(leaf)) {
ret = btrfs_next_leaf(root, path);
if (ret == 0)
continue;
if (ret < 0)
goto error;
break;
}
btrfs_item_key_to_cpu(leaf, &found_key, slot);
if (found_key.type == BTRFS_DEV_ITEM_KEY) {
struct btrfs_dev_item *dev_item;
dev_item = btrfs_item_ptr(leaf, slot,
struct btrfs_dev_item);
ret = read_one_dev(root, leaf, dev_item);
BUG_ON(ret);
} else if (found_key.type == BTRFS_CHUNK_ITEM_KEY) {
struct btrfs_chunk *chunk;
chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
ret = read_one_chunk(root, &found_key, leaf, chunk,
slot);
BUG_ON(ret);
}
path->slots[0]++;
}
ret = 0;
error:
btrfs_free_path(path);
return ret;
}
struct list_head *btrfs_scanned_uuids(void)
{
return &fs_uuids;
}
static int rmw_eb(struct btrfs_fs_info *info,
struct extent_buffer *eb, struct extent_buffer *orig_eb)
{
int ret;
unsigned long orig_off = 0;
unsigned long dest_off = 0;
unsigned long copy_len = eb->len;
ret = read_whole_eb(info, eb, 0);
if (ret)
return ret;
if (eb->start + eb->len <= orig_eb->start ||
eb->start >= orig_eb->start + orig_eb->len)
return 0;
/*
* | ----- orig_eb ------- |
* | ----- stripe ------- |
* | ----- orig_eb ------- |
* | ----- orig_eb ------- |
*/
if (eb->start > orig_eb->start)
orig_off = eb->start - orig_eb->start;
if (orig_eb->start > eb->start)
dest_off = orig_eb->start - eb->start;
if (copy_len > orig_eb->len - orig_off)
copy_len = orig_eb->len - orig_off;
if (copy_len > eb->len - dest_off)
copy_len = eb->len - dest_off;
memcpy(eb->data + dest_off, orig_eb->data + orig_off, copy_len);
return 0;
}
static int split_eb_for_raid56(struct btrfs_fs_info *info,
struct extent_buffer *orig_eb,
struct extent_buffer **ebs,
u64 stripe_len, u64 *raid_map,
int num_stripes)
{
struct extent_buffer **tmp_ebs;
u64 start = orig_eb->start;
u64 this_eb_start;
int i;
int ret = 0;
tmp_ebs = calloc(num_stripes, sizeof(*tmp_ebs));
if (!tmp_ebs)
return -ENOMEM;
/* Alloc memory in a row for data stripes */
for (i = 0; i < num_stripes; i++) {
if (raid_map[i] >= BTRFS_RAID5_P_STRIPE)
break;
tmp_ebs[i] = calloc(1, sizeof(**tmp_ebs) + stripe_len);
if (!tmp_ebs[i]) {
ret = -ENOMEM;
goto clean_up;
}
}
for (i = 0; i < num_stripes; i++) {
struct extent_buffer *eb = tmp_ebs[i];
if (raid_map[i] >= BTRFS_RAID5_P_STRIPE)
break;
eb->start = raid_map[i];
eb->len = stripe_len;
eb->refs = 1;
eb->flags = 0;
eb->fd = -1;
eb->dev_bytenr = (u64)-1;
this_eb_start = raid_map[i];
if (start > this_eb_start ||
start + orig_eb->len < this_eb_start + stripe_len) {
ret = rmw_eb(info, eb, orig_eb);
if (ret)
goto clean_up;
} else {
memcpy(eb->data, orig_eb->data + eb->start - start,
stripe_len);
}
ebs[i] = eb;
}
free(tmp_ebs);
return ret;
clean_up:
for (i = 0; i < num_stripes; i++)
free(tmp_ebs[i]);
free(tmp_ebs);
return ret;
}
int write_raid56_with_parity(struct btrfs_fs_info *info,
struct extent_buffer *eb,
struct btrfs_multi_bio *multi,
u64 stripe_len, u64 *raid_map)
{
struct extent_buffer **ebs, *p_eb = NULL, *q_eb = NULL;
int i;
int ret;
int alloc_size = eb->len;
void **pointers;
ebs = malloc(sizeof(*ebs) * multi->num_stripes);
pointers = malloc(sizeof(*pointers) * multi->num_stripes);
if (!ebs || !pointers) {
free(ebs);
free(pointers);
return -ENOMEM;
}
if (stripe_len > alloc_size)
alloc_size = stripe_len;
ret = split_eb_for_raid56(info, eb, ebs, stripe_len, raid_map,
multi->num_stripes);
if (ret)
goto out;
for (i = 0; i < multi->num_stripes; i++) {
struct extent_buffer *new_eb;
if (raid_map[i] < BTRFS_RAID5_P_STRIPE) {
ebs[i]->dev_bytenr = multi->stripes[i].physical;
ebs[i]->fd = multi->stripes[i].dev->fd;
multi->stripes[i].dev->total_ios++;
if (ebs[i]->start != raid_map[i]) {
ret = -EINVAL;
goto out_free_split;
}
continue;
}
new_eb = malloc(sizeof(*eb) + alloc_size);
if (!new_eb) {
ret = -ENOMEM;
goto out_free_split;
}
new_eb->dev_bytenr = multi->stripes[i].physical;
new_eb->fd = multi->stripes[i].dev->fd;
multi->stripes[i].dev->total_ios++;
new_eb->len = stripe_len;
if (raid_map[i] == BTRFS_RAID5_P_STRIPE)
p_eb = new_eb;
else if (raid_map[i] == BTRFS_RAID6_Q_STRIPE)
q_eb = new_eb;
}
if (q_eb) {
ebs[multi->num_stripes - 2] = p_eb;
ebs[multi->num_stripes - 1] = q_eb;
for (i = 0; i < multi->num_stripes; i++)
pointers[i] = ebs[i]->data;
raid6_gen_syndrome(multi->num_stripes, stripe_len, pointers);
} else {
ebs[multi->num_stripes - 1] = p_eb;
for (i = 0; i < multi->num_stripes; i++)
pointers[i] = ebs[i]->data;
ret = raid5_gen_result(multi->num_stripes, stripe_len,
multi->num_stripes - 1, pointers);
if (ret < 0)
goto out_free_split;
}
for (i = 0; i < multi->num_stripes; i++) {
ret = write_extent_to_disk(ebs[i]);
if (ret < 0)
goto out_free_split;
}
out_free_split:
for (i = 0; i < multi->num_stripes; i++) {
if (ebs[i] != eb)
free(ebs[i]);
}
out:
free(ebs);
free(pointers);
return ret;
}
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