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btrfs-progs/disk-io.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 <fcntl.h>
#include <unistd.h>
#include <uuid/uuid.h>
#include "kerncompat.h"
#include "radix-tree.h"
#include "ctree.h"
#include "disk-io.h"
#include "volumes.h"
#include "transaction.h"
#include "crc32c.h"
#include "utils.h"
#include "print-tree.h"
#include "rbtree-utils.h"
/* specified errno for check_tree_block */
#define BTRFS_BAD_BYTENR (-1)
#define BTRFS_BAD_FSID (-2)
#define BTRFS_BAD_LEVEL (-3)
#define BTRFS_BAD_NRITEMS (-4)
/* Calculate max possible nritems for a leaf/node */
static u32 max_nritems(u8 level, u32 nodesize)
{
if (level == 0)
return ((nodesize - sizeof(struct btrfs_header)) /
sizeof(struct btrfs_item));
return ((nodesize - sizeof(struct btrfs_header)) /
sizeof(struct btrfs_key_ptr));
}
static int check_tree_block(struct btrfs_fs_info *fs_info,
struct extent_buffer *buf)
{
struct btrfs_fs_devices *fs_devices;
u32 nodesize = btrfs_super_nodesize(fs_info->super_copy);
int ret = BTRFS_BAD_FSID;
if (buf->start != btrfs_header_bytenr(buf))
return BTRFS_BAD_BYTENR;
if (btrfs_header_level(buf) >= BTRFS_MAX_LEVEL)
return BTRFS_BAD_LEVEL;
if (btrfs_header_nritems(buf) > max_nritems(btrfs_header_level(buf),
nodesize))
return BTRFS_BAD_NRITEMS;
fs_devices = fs_info->fs_devices;
while (fs_devices) {
if (fs_info->ignore_fsid_mismatch ||
!memcmp_extent_buffer(buf, fs_devices->fsid,
btrfs_header_fsid(),
BTRFS_FSID_SIZE)) {
ret = 0;
break;
}
fs_devices = fs_devices->seed;
}
return ret;
}
static void print_tree_block_error(struct btrfs_fs_info *fs_info,
struct extent_buffer *eb,
int err)
{
char fs_uuid[BTRFS_UUID_UNPARSED_SIZE] = {'\0'};
char found_uuid[BTRFS_UUID_UNPARSED_SIZE] = {'\0'};
u8 buf[BTRFS_UUID_SIZE];
switch (err) {
case BTRFS_BAD_FSID:
read_extent_buffer(eb, buf, btrfs_header_fsid(),
BTRFS_UUID_SIZE);
uuid_unparse(buf, found_uuid);
uuid_unparse(fs_info->fsid, fs_uuid);
fprintf(stderr, "fsid mismatch, want=%s, have=%s\n",
fs_uuid, found_uuid);
break;
case BTRFS_BAD_BYTENR:
fprintf(stderr, "bytenr mismatch, want=%llu, have=%llu\n",
eb->start, btrfs_header_bytenr(eb));
break;
case BTRFS_BAD_LEVEL:
fprintf(stderr, "bad level, %u > %u\n",
btrfs_header_level(eb), BTRFS_MAX_LEVEL);
break;
case BTRFS_BAD_NRITEMS:
fprintf(stderr, "invalid nr_items: %u\n",
btrfs_header_nritems(eb));
break;
}
}
u32 btrfs_csum_data(struct btrfs_root *root, char *data, u32 seed, size_t len)
{
return crc32c(seed, data, len);
}
void btrfs_csum_final(u32 crc, char *result)
{
*(__le32 *)result = ~cpu_to_le32(crc);
}
static int __csum_tree_block_size(struct extent_buffer *buf, u16 csum_size,
int verify, int silent)
{
char result[BTRFS_CSUM_SIZE];
u32 len;
u32 crc = ~(u32)0;
len = buf->len - BTRFS_CSUM_SIZE;
crc = crc32c(crc, buf->data + BTRFS_CSUM_SIZE, len);
btrfs_csum_final(crc, result);
if (verify) {
if (memcmp_extent_buffer(buf, result, 0, csum_size)) {
if (!silent)
printk("checksum verify failed on %llu found %08X wanted %08X\n",
(unsigned long long)buf->start,
*((u32 *)result),
*((u32*)(char *)buf->data));
return 1;
}
} else {
write_extent_buffer(buf, result, 0, csum_size);
}
return 0;
}
int csum_tree_block_size(struct extent_buffer *buf, u16 csum_size, int verify)
{
return __csum_tree_block_size(buf, csum_size, verify, 0);
}
int verify_tree_block_csum_silent(struct extent_buffer *buf, u16 csum_size)
{
return __csum_tree_block_size(buf, csum_size, 1, 1);
}
static int csum_tree_block_fs_info(struct btrfs_fs_info *fs_info,
struct extent_buffer *buf, int verify)
{
u16 csum_size =
btrfs_super_csum_size(fs_info->super_copy);
if (verify && fs_info->suppress_check_block_errors)
return verify_tree_block_csum_silent(buf, csum_size);
return csum_tree_block_size(buf, csum_size, verify);
}
int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf,
int verify)
{
return csum_tree_block_fs_info(root->fs_info, buf, verify);
}
struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root,
u64 bytenr, u32 blocksize)
{
return find_extent_buffer(&root->fs_info->extent_cache,
bytenr, blocksize);
}
struct extent_buffer* btrfs_find_create_tree_block(
struct btrfs_fs_info *fs_info, u64 bytenr, u32 blocksize)
{
return alloc_extent_buffer(&fs_info->extent_cache, bytenr, blocksize);
}
void readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize,
u64 parent_transid)
{
struct extent_buffer *eb;
u64 length;
struct btrfs_multi_bio *multi = NULL;
struct btrfs_device *device;
eb = btrfs_find_tree_block(root, bytenr, blocksize);
if (!(eb && btrfs_buffer_uptodate(eb, parent_transid)) &&
!btrfs_map_block(&root->fs_info->mapping_tree, READ,
bytenr, &length, &multi, 0, NULL)) {
device = multi->stripes[0].dev;
device->total_ios++;
blocksize = min(blocksize, (u32)(64 * 1024));
readahead(device->fd, multi->stripes[0].physical, blocksize);
}
free_extent_buffer(eb);
kfree(multi);
}
static int verify_parent_transid(struct extent_io_tree *io_tree,
struct extent_buffer *eb, u64 parent_transid,
int ignore)
{
int ret;
if (!parent_transid || btrfs_header_generation(eb) == parent_transid)
return 0;
if (extent_buffer_uptodate(eb) &&
btrfs_header_generation(eb) == parent_transid) {
ret = 0;
goto out;
}
printk("parent transid verify failed on %llu wanted %llu found %llu\n",
(unsigned long long)eb->start,
(unsigned long long)parent_transid,
(unsigned long long)btrfs_header_generation(eb));
if (ignore) {
eb->flags |= EXTENT_BAD_TRANSID;
printk("Ignoring transid failure\n");
return 0;
}
ret = 1;
out:
clear_extent_buffer_uptodate(io_tree, eb);
return ret;
}
int read_whole_eb(struct btrfs_fs_info *info, struct extent_buffer *eb, int mirror)
{
unsigned long offset = 0;
struct btrfs_multi_bio *multi = NULL;
struct btrfs_device *device;
int ret = 0;
u64 read_len;
unsigned long bytes_left = eb->len;
while (bytes_left) {
read_len = bytes_left;
device = NULL;
if (!info->on_restoring &&
eb->start != BTRFS_SUPER_INFO_OFFSET) {
ret = btrfs_map_block(&info->mapping_tree, READ,
eb->start + offset, &read_len, &multi,
mirror, NULL);
if (ret) {
printk("Couldn't map the block %Lu\n", eb->start + offset);
kfree(multi);
return -EIO;
}
device = multi->stripes[0].dev;
if (device->fd <= 0) {
kfree(multi);
return -EIO;
}
eb->fd = device->fd;
device->total_ios++;
eb->dev_bytenr = multi->stripes[0].physical;
kfree(multi);
multi = NULL;
} else {
/* special case for restore metadump */
list_for_each_entry(device, &info->fs_devices->devices, dev_list) {
if (device->devid == 1)
break;
}
eb->fd = device->fd;
eb->dev_bytenr = eb->start;
device->total_ios++;
}
if (read_len > bytes_left)
read_len = bytes_left;
ret = read_extent_from_disk(eb, offset, read_len);
if (ret)
return -EIO;
offset += read_len;
bytes_left -= read_len;
}
return 0;
}
struct extent_buffer* read_tree_block_fs_info(
struct btrfs_fs_info *fs_info, u64 bytenr, u32 blocksize,
u64 parent_transid)
{
int ret;
struct extent_buffer *eb;
u64 best_transid = 0;
int mirror_num = 0;
int good_mirror = 0;
int num_copies;
int ignore = 0;
eb = btrfs_find_create_tree_block(fs_info, bytenr, blocksize);
if (!eb)
return ERR_PTR(-ENOMEM);
if (btrfs_buffer_uptodate(eb, parent_transid))
return eb;
while (1) {
ret = read_whole_eb(fs_info, eb, mirror_num);
if (ret == 0 && csum_tree_block_fs_info(fs_info, eb, 1) == 0 &&
check_tree_block(fs_info, eb) == 0 &&
verify_parent_transid(eb->tree, eb, parent_transid, ignore)
== 0) {
if (eb->flags & EXTENT_BAD_TRANSID &&
list_empty(&eb->recow)) {
list_add_tail(&eb->recow,
&fs_info->recow_ebs);
eb->refs++;
}
btrfs_set_buffer_uptodate(eb);
return eb;
}
if (ignore) {
if (check_tree_block(fs_info, eb)) {
if (!fs_info->suppress_check_block_errors)
print_tree_block_error(fs_info, eb,
check_tree_block(fs_info, eb));
} else {
if (!fs_info->suppress_check_block_errors)
fprintf(stderr, "Csum didn't match\n");
}
ret = -EIO;
break;
}
num_copies = btrfs_num_copies(&fs_info->mapping_tree,
eb->start, eb->len);
if (num_copies == 1) {
ignore = 1;
continue;
}
if (btrfs_header_generation(eb) > best_transid && mirror_num) {
best_transid = btrfs_header_generation(eb);
good_mirror = mirror_num;
}
mirror_num++;
if (mirror_num > num_copies) {
mirror_num = good_mirror;
ignore = 1;
continue;
}
}
free_extent_buffer(eb);
return ERR_PTR(ret);
}
int read_extent_data(struct btrfs_root *root, char *data,
u64 logical, u64 *len, int mirror)
{
u64 offset = 0;
struct btrfs_multi_bio *multi = NULL;
struct btrfs_fs_info *info = root->fs_info;
struct btrfs_device *device;
int ret = 0;
u64 max_len = *len;
ret = btrfs_map_block(&info->mapping_tree, READ, logical, len,
&multi, mirror, NULL);
if (ret) {
fprintf(stderr, "Couldn't map the block %llu\n",
logical + offset);
goto err;
}
device = multi->stripes[0].dev;
if (device->fd <= 0)
goto err;
if (*len > max_len)
*len = max_len;
ret = pread64(device->fd, data, *len, multi->stripes[0].physical);
if (ret != *len)
ret = -EIO;
else
ret = 0;
err:
kfree(multi);
return ret;
}
int write_and_map_eb(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct extent_buffer *eb)
{
int ret;
int dev_nr;
u64 length;
u64 *raid_map = NULL;
struct btrfs_multi_bio *multi = NULL;
dev_nr = 0;
length = eb->len;
ret = btrfs_map_block(&root->fs_info->mapping_tree, WRITE,
eb->start, &length, &multi, 0, &raid_map);
if (raid_map) {
ret = write_raid56_with_parity(root->fs_info, eb, multi,
length, raid_map);
BUG_ON(ret);
} else while (dev_nr < multi->num_stripes) {
BUG_ON(ret);
eb->fd = multi->stripes[dev_nr].dev->fd;
eb->dev_bytenr = multi->stripes[dev_nr].physical;
multi->stripes[dev_nr].dev->total_ios++;
dev_nr++;
ret = write_extent_to_disk(eb);
BUG_ON(ret);
}
kfree(raid_map);
kfree(multi);
return 0;
}
int write_tree_block(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct extent_buffer *eb)
{
if (check_tree_block(root->fs_info, eb)) {
print_tree_block_error(root->fs_info, eb,
check_tree_block(root->fs_info, eb));
BUG();
}
if (trans && !btrfs_buffer_uptodate(eb, trans->transid))
BUG();
btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
csum_tree_block(root, eb, 0);
return write_and_map_eb(trans, root, eb);
}
int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
u32 stripesize, struct btrfs_root *root,
struct btrfs_fs_info *fs_info, u64 objectid)
{
root->node = NULL;
root->commit_root = NULL;
root->sectorsize = sectorsize;
root->nodesize = nodesize;
root->leafsize = leafsize;
root->stripesize = stripesize;
root->ref_cows = 0;
root->track_dirty = 0;
root->fs_info = fs_info;
root->objectid = objectid;
root->last_trans = 0;
root->highest_inode = 0;
root->last_inode_alloc = 0;
INIT_LIST_HEAD(&root->dirty_list);
INIT_LIST_HEAD(&root->orphan_data_extents);
memset(&root->root_key, 0, sizeof(root->root_key));
memset(&root->root_item, 0, sizeof(root->root_item));
root->root_key.objectid = objectid;
return 0;
}
static int update_cowonly_root(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
int ret;
u64 old_root_bytenr;
struct btrfs_root *tree_root = root->fs_info->tree_root;
btrfs_write_dirty_block_groups(trans, root);
while(1) {
old_root_bytenr = btrfs_root_bytenr(&root->root_item);
if (old_root_bytenr == root->node->start)
break;
btrfs_set_root_bytenr(&root->root_item,
root->node->start);
btrfs_set_root_generation(&root->root_item,
trans->transid);
root->root_item.level = btrfs_header_level(root->node);
ret = btrfs_update_root(trans, tree_root,
&root->root_key,
&root->root_item);
BUG_ON(ret);
btrfs_write_dirty_block_groups(trans, root);
}
return 0;
}
static int commit_tree_roots(struct btrfs_trans_handle *trans,
struct btrfs_fs_info *fs_info)
{
struct btrfs_root *root;
struct list_head *next;
struct extent_buffer *eb;
int ret;
if (fs_info->readonly)
return 0;
eb = fs_info->tree_root->node;
extent_buffer_get(eb);
ret = btrfs_cow_block(trans, fs_info->tree_root, eb, NULL, 0, &eb);
free_extent_buffer(eb);
if (ret)
return ret;
while(!list_empty(&fs_info->dirty_cowonly_roots)) {
next = fs_info->dirty_cowonly_roots.next;
list_del_init(next);
root = list_entry(next, struct btrfs_root, dirty_list);
update_cowonly_root(trans, root);
free_extent_buffer(root->commit_root);
root->commit_root = NULL;
}
return 0;
}
static int __commit_transaction(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
u64 start;
u64 end;
struct extent_buffer *eb;
struct extent_io_tree *tree = &root->fs_info->extent_cache;
int ret;
while(1) {
ret = find_first_extent_bit(tree, 0, &start, &end,
EXTENT_DIRTY);
if (ret)
break;
while(start <= end) {
eb = find_first_extent_buffer(tree, start);
BUG_ON(!eb || eb->start != start);
ret = write_tree_block(trans, root, eb);
BUG_ON(ret);
start += eb->len;
clear_extent_buffer_dirty(eb);
free_extent_buffer(eb);
}
}
return 0;
}
int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
u64 transid = trans->transid;
int ret = 0;
struct btrfs_fs_info *fs_info = root->fs_info;
if (root->commit_root == root->node)
goto commit_tree;
if (root == root->fs_info->tree_root)
goto commit_tree;
if (root == root->fs_info->chunk_root)
goto commit_tree;
free_extent_buffer(root->commit_root);
root->commit_root = NULL;
btrfs_set_root_bytenr(&root->root_item, root->node->start);
btrfs_set_root_generation(&root->root_item, trans->transid);
root->root_item.level = btrfs_header_level(root->node);
ret = btrfs_update_root(trans, root->fs_info->tree_root,
&root->root_key, &root->root_item);
BUG_ON(ret);
commit_tree:
ret = commit_tree_roots(trans, fs_info);
BUG_ON(ret);
ret = __commit_transaction(trans, root);
BUG_ON(ret);
write_ctree_super(trans, root);
btrfs_finish_extent_commit(trans, fs_info->extent_root,
&fs_info->pinned_extents);
btrfs_free_transaction(root, trans);
free_extent_buffer(root->commit_root);
root->commit_root = NULL;
fs_info->running_transaction = NULL;
fs_info->last_trans_committed = transid;
return 0;
}
static int find_and_setup_root(struct btrfs_root *tree_root,
struct btrfs_fs_info *fs_info,
u64 objectid, struct btrfs_root *root)
{
int ret;
u32 blocksize;
u64 generation;
__setup_root(tree_root->nodesize, tree_root->leafsize,
tree_root->sectorsize, tree_root->stripesize,
root, fs_info, objectid);
ret = btrfs_find_last_root(tree_root, objectid,
&root->root_item, &root->root_key);
if (ret)
return ret;
blocksize = root->nodesize;
generation = btrfs_root_generation(&root->root_item);
root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
blocksize, generation);
if (!extent_buffer_uptodate(root->node))
return -EIO;
return 0;
}
static int find_and_setup_log_root(struct btrfs_root *tree_root,
struct btrfs_fs_info *fs_info,
struct btrfs_super_block *disk_super)
{
u32 blocksize;
u64 blocknr = btrfs_super_log_root(disk_super);
struct btrfs_root *log_root = malloc(sizeof(struct btrfs_root));
if (!log_root)
return -ENOMEM;
if (blocknr == 0) {
free(log_root);
return 0;
}
blocksize = tree_root->nodesize;
__setup_root(tree_root->nodesize, tree_root->leafsize,
tree_root->sectorsize, tree_root->stripesize,
log_root, fs_info, BTRFS_TREE_LOG_OBJECTID);
log_root->node = read_tree_block(tree_root, blocknr,
blocksize,
btrfs_super_generation(disk_super) + 1);
fs_info->log_root_tree = log_root;
if (!extent_buffer_uptodate(log_root->node)) {
free_extent_buffer(log_root->node);
free(log_root);
fs_info->log_root_tree = NULL;
return -EIO;
}
return 0;
}
int btrfs_free_fs_root(struct btrfs_root *root)
{
if (root->node)
free_extent_buffer(root->node);
if (root->commit_root)
free_extent_buffer(root->commit_root);
kfree(root);
return 0;
}
static void __free_fs_root(struct rb_node *node)
{
struct btrfs_root *root;
root = container_of(node, struct btrfs_root, rb_node);
btrfs_free_fs_root(root);
}
FREE_RB_BASED_TREE(fs_roots, __free_fs_root);
struct btrfs_root *btrfs_read_fs_root_no_cache(struct btrfs_fs_info *fs_info,
struct btrfs_key *location)
{
struct btrfs_root *root;
struct btrfs_root *tree_root = fs_info->tree_root;
struct btrfs_path *path;
struct extent_buffer *l;
u64 generation;
u32 blocksize;
int ret = 0;
root = calloc(1, sizeof(*root));
if (!root)
return ERR_PTR(-ENOMEM);
if (location->offset == (u64)-1) {
ret = find_and_setup_root(tree_root, fs_info,
location->objectid, root);
if (ret) {
free(root);
return ERR_PTR(ret);
}
goto insert;
}
__setup_root(tree_root->nodesize, tree_root->leafsize,
tree_root->sectorsize, tree_root->stripesize,
root, fs_info, location->objectid);
path = btrfs_alloc_path();
BUG_ON(!path);
ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
if (ret != 0) {
if (ret > 0)
ret = -ENOENT;
goto out;
}
l = path->nodes[0];
read_extent_buffer(l, &root->root_item,
btrfs_item_ptr_offset(l, path->slots[0]),
sizeof(root->root_item));
memcpy(&root->root_key, location, sizeof(*location));
ret = 0;
out:
btrfs_free_path(path);
if (ret) {
free(root);
return ERR_PTR(ret);
}
generation = btrfs_root_generation(&root->root_item);
blocksize = root->nodesize;
root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
blocksize, generation);
if (!extent_buffer_uptodate(root->node)) {
free(root);
return ERR_PTR(-EIO);
}
insert:
root->ref_cows = 1;
return root;
}
static int btrfs_fs_roots_compare_objectids(struct rb_node *node,
void *data)
{
u64 objectid = *((u64 *)data);
struct btrfs_root *root;
root = rb_entry(node, struct btrfs_root, rb_node);
if (objectid > root->objectid)
return 1;
else if (objectid < root->objectid)
return -1;
else
return 0;
}
static int btrfs_fs_roots_compare_roots(struct rb_node *node1,
struct rb_node *node2)
{
struct btrfs_root *root;
root = rb_entry(node2, struct btrfs_root, rb_node);
return btrfs_fs_roots_compare_objectids(node1, (void *)&root->objectid);
}
struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
struct btrfs_key *location)
{
struct btrfs_root *root;
struct rb_node *node;
int ret;
u64 objectid = location->objectid;
if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
return fs_info->tree_root;
if (location->objectid == BTRFS_EXTENT_TREE_OBJECTID)
return fs_info->extent_root;
if (location->objectid == BTRFS_CHUNK_TREE_OBJECTID)
return fs_info->chunk_root;
if (location->objectid == BTRFS_DEV_TREE_OBJECTID)
return fs_info->dev_root;
if (location->objectid == BTRFS_CSUM_TREE_OBJECTID)
return fs_info->csum_root;
if (location->objectid == BTRFS_QUOTA_TREE_OBJECTID)
return fs_info->quota_root;
BUG_ON(location->objectid == BTRFS_TREE_RELOC_OBJECTID ||
location->offset != (u64)-1);
node = rb_search(&fs_info->fs_root_tree, (void *)&objectid,
btrfs_fs_roots_compare_objectids, NULL);
if (node)
return container_of(node, struct btrfs_root, rb_node);
root = btrfs_read_fs_root_no_cache(fs_info, location);
if (IS_ERR(root))
return root;
ret = rb_insert(&fs_info->fs_root_tree, &root->rb_node,
btrfs_fs_roots_compare_roots);
BUG_ON(ret);
return root;
}
void btrfs_free_fs_info(struct btrfs_fs_info *fs_info)
{
free(fs_info->tree_root);
free(fs_info->extent_root);
free(fs_info->chunk_root);
free(fs_info->dev_root);
free(fs_info->csum_root);
free(fs_info->quota_root);
free(fs_info->free_space_root);
free(fs_info->super_copy);
free(fs_info->log_root_tree);
free(fs_info);
}
struct btrfs_fs_info *btrfs_new_fs_info(int writable, u64 sb_bytenr)
{
struct btrfs_fs_info *fs_info;
fs_info = calloc(1, sizeof(struct btrfs_fs_info));
if (!fs_info)
return NULL;
fs_info->tree_root = calloc(1, sizeof(struct btrfs_root));
fs_info->extent_root = calloc(1, sizeof(struct btrfs_root));
fs_info->chunk_root = calloc(1, sizeof(struct btrfs_root));
fs_info->dev_root = calloc(1, sizeof(struct btrfs_root));
fs_info->csum_root = calloc(1, sizeof(struct btrfs_root));
fs_info->quota_root = calloc(1, sizeof(struct btrfs_root));
fs_info->free_space_root = calloc(1, sizeof(struct btrfs_root));
fs_info->super_copy = calloc(1, BTRFS_SUPER_INFO_SIZE);
if (!fs_info->tree_root || !fs_info->extent_root ||
!fs_info->chunk_root || !fs_info->dev_root ||
!fs_info->csum_root || !fs_info->quota_root ||
!fs_info->free_space_root || !fs_info->super_copy)
goto free_all;
extent_io_tree_init(&fs_info->extent_cache);
extent_io_tree_init(&fs_info->free_space_cache);
extent_io_tree_init(&fs_info->block_group_cache);
extent_io_tree_init(&fs_info->pinned_extents);
extent_io_tree_init(&fs_info->pending_del);
extent_io_tree_init(&fs_info->extent_ins);
fs_info->excluded_extents = NULL;
fs_info->fs_root_tree = RB_ROOT;
cache_tree_init(&fs_info->mapping_tree.cache_tree);
mutex_init(&fs_info->fs_mutex);
INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
INIT_LIST_HEAD(&fs_info->space_info);
INIT_LIST_HEAD(&fs_info->recow_ebs);
if (!writable)
fs_info->readonly = 1;
fs_info->super_bytenr = sb_bytenr;
fs_info->data_alloc_profile = (u64)-1;
fs_info->metadata_alloc_profile = (u64)-1;
fs_info->system_alloc_profile = fs_info->metadata_alloc_profile;
return fs_info;
free_all:
btrfs_free_fs_info(fs_info);
return NULL;
}
int btrfs_check_fs_compatibility(struct btrfs_super_block *sb, int writable)
{
u64 features;
features = btrfs_super_incompat_flags(sb) &
~BTRFS_FEATURE_INCOMPAT_SUPP;
if (features) {
printk("couldn't open because of unsupported "
"option features (%Lx).\n",
(unsigned long long)features);
return -ENOTSUP;
}
features = btrfs_super_incompat_flags(sb);
if (!(features & BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF)) {
features |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF;
btrfs_set_super_incompat_flags(sb, features);
}
features = btrfs_super_compat_ro_flags(sb) &
~BTRFS_FEATURE_COMPAT_RO_SUPP;
if (writable && features) {
printk("couldn't open RDWR because of unsupported "
"option features (%Lx).\n",
(unsigned long long)features);
return -ENOTSUP;
}
return 0;
}
static int find_best_backup_root(struct btrfs_super_block *super)
{
struct btrfs_root_backup *backup;
u64 orig_gen = btrfs_super_generation(super);
u64 gen = 0;
int best_index = 0;
int i;
for (i = 0; i < BTRFS_NUM_BACKUP_ROOTS; i++) {
backup = super->super_roots + i;
if (btrfs_backup_tree_root_gen(backup) != orig_gen &&
btrfs_backup_tree_root_gen(backup) > gen) {
best_index = i;
gen = btrfs_backup_tree_root_gen(backup);
}
}
return best_index;
}
static int setup_root_or_create_block(struct btrfs_fs_info *fs_info,
enum btrfs_open_ctree_flags flags,
struct btrfs_root *info_root,
u64 objectid, char *str)
{
struct btrfs_super_block *sb = fs_info->super_copy;
struct btrfs_root *root = fs_info->tree_root;
u32 nodesize = btrfs_super_nodesize(sb);
int ret;
ret = find_and_setup_root(root, fs_info, objectid, info_root);
if (ret) {
printk("Couldn't setup %s tree\n", str);
if (!(flags & OPEN_CTREE_PARTIAL))
return -EIO;
/*
* Need a blank node here just so we don't screw up in the
* million of places that assume a root has a valid ->node
*/
info_root->node =
btrfs_find_create_tree_block(fs_info, 0, nodesize);
if (!info_root->node)
return -ENOMEM;
clear_extent_buffer_uptodate(NULL, info_root->node);
}
return 0;
}
int btrfs_setup_all_roots(struct btrfs_fs_info *fs_info, u64 root_tree_bytenr,
enum btrfs_open_ctree_flags flags)
{
struct btrfs_super_block *sb = fs_info->super_copy;
struct btrfs_root *root;
struct btrfs_key key;
u32 sectorsize;
u32 nodesize;
u32 leafsize;
u32 stripesize;
u64 generation;
u32 blocksize;
int ret;
nodesize = btrfs_super_nodesize(sb);
leafsize = btrfs_super_leafsize(sb);
sectorsize = btrfs_super_sectorsize(sb);
stripesize = btrfs_super_stripesize(sb);
root = fs_info->tree_root;
__setup_root(nodesize, leafsize, sectorsize, stripesize,
root, fs_info, BTRFS_ROOT_TREE_OBJECTID);
blocksize = root->nodesize;
generation = btrfs_super_generation(sb);
if (!root_tree_bytenr && !(flags & OPEN_CTREE_BACKUP_ROOT)) {
root_tree_bytenr = btrfs_super_root(sb);
} else if (flags & OPEN_CTREE_BACKUP_ROOT) {
struct btrfs_root_backup *backup;
int index = find_best_backup_root(sb);
if (index >= BTRFS_NUM_BACKUP_ROOTS) {
fprintf(stderr, "Invalid backup root number\n");
return -EIO;
}
backup = fs_info->super_copy->super_roots + index;
root_tree_bytenr = btrfs_backup_tree_root(backup);
generation = btrfs_backup_tree_root_gen(backup);
}
root->node = read_tree_block(root, root_tree_bytenr, blocksize,
generation);
if (!extent_buffer_uptodate(root->node)) {
fprintf(stderr, "Couldn't read tree root\n");
return -EIO;
}
ret = setup_root_or_create_block(fs_info, flags, fs_info->extent_root,
BTRFS_EXTENT_TREE_OBJECTID, "extent");
if (ret)
return ret;
fs_info->extent_root->track_dirty = 1;
ret = find_and_setup_root(root, fs_info, BTRFS_DEV_TREE_OBJECTID,
fs_info->dev_root);
if (ret) {
printk("Couldn't setup device tree\n");
return -EIO;
}
fs_info->dev_root->track_dirty = 1;
ret = setup_root_or_create_block(fs_info, flags, fs_info->csum_root,
BTRFS_CSUM_TREE_OBJECTID, "csum");
if (ret)
return ret;
fs_info->csum_root->track_dirty = 1;
ret = find_and_setup_root(root, fs_info, BTRFS_QUOTA_TREE_OBJECTID,
fs_info->quota_root);
if (ret == 0)
fs_info->quota_enabled = 1;
if (btrfs_fs_compat_ro(fs_info, BTRFS_FEATURE_COMPAT_RO_FREE_SPACE_TREE)) {
ret = find_and_setup_root(root, fs_info, BTRFS_FREE_SPACE_TREE_OBJECTID,
fs_info->free_space_root);
if (ret) {
printk("Couldn't read free space tree\n");
return -EIO;
}
fs_info->free_space_root->track_dirty = 1;
}
ret = find_and_setup_log_root(root, fs_info, sb);
if (ret) {
printk("Couldn't setup log root tree\n");
if (!(flags & OPEN_CTREE_PARTIAL))
return -EIO;
}
fs_info->generation = generation;
fs_info->last_trans_committed = generation;
if (extent_buffer_uptodate(fs_info->extent_root->node) &&
!(flags & OPEN_CTREE_NO_BLOCK_GROUPS))
btrfs_read_block_groups(fs_info->tree_root);
key.objectid = BTRFS_FS_TREE_OBJECTID;
key.type = BTRFS_ROOT_ITEM_KEY;
key.offset = (u64)-1;
fs_info->fs_root = btrfs_read_fs_root(fs_info, &key);
if (IS_ERR(fs_info->fs_root))
return -EIO;
return 0;
}
void btrfs_release_all_roots(struct btrfs_fs_info *fs_info)
{
if (fs_info->free_space_root)
free_extent_buffer(fs_info->free_space_root->node);
if (fs_info->quota_root)
free_extent_buffer(fs_info->quota_root->node);
if (fs_info->csum_root)
free_extent_buffer(fs_info->csum_root->node);
if (fs_info->dev_root)
free_extent_buffer(fs_info->dev_root->node);
if (fs_info->extent_root)
free_extent_buffer(fs_info->extent_root->node);
if (fs_info->tree_root)
free_extent_buffer(fs_info->tree_root->node);
if (fs_info->log_root_tree)
free_extent_buffer(fs_info->log_root_tree->node);
if (fs_info->chunk_root)
free_extent_buffer(fs_info->chunk_root->node);
}
static void free_map_lookup(struct cache_extent *ce)
{
struct map_lookup *map;
map = container_of(ce, struct map_lookup, ce);
kfree(map);
}
FREE_EXTENT_CACHE_BASED_TREE(mapping_cache, free_map_lookup);
void btrfs_cleanup_all_caches(struct btrfs_fs_info *fs_info)
{
while (!list_empty(&fs_info->recow_ebs)) {
struct extent_buffer *eb;
eb = list_first_entry(&fs_info->recow_ebs,
struct extent_buffer, recow);
list_del_init(&eb->recow);
free_extent_buffer(eb);
}
free_mapping_cache_tree(&fs_info->mapping_tree.cache_tree);
extent_io_tree_cleanup(&fs_info->extent_cache);
extent_io_tree_cleanup(&fs_info->free_space_cache);
extent_io_tree_cleanup(&fs_info->block_group_cache);
extent_io_tree_cleanup(&fs_info->pinned_extents);
extent_io_tree_cleanup(&fs_info->pending_del);
extent_io_tree_cleanup(&fs_info->extent_ins);
}
int btrfs_scan_fs_devices(int fd, const char *path,
struct btrfs_fs_devices **fs_devices,
u64 sb_bytenr, int super_recover,
int skip_devices)
{
u64 total_devs;
u64 dev_size;
off_t seek_ret;
int ret;
if (!sb_bytenr)
sb_bytenr = BTRFS_SUPER_INFO_OFFSET;
seek_ret = lseek(fd, 0, SEEK_END);
if (seek_ret < 0)
return -errno;
dev_size = seek_ret;
lseek(fd, 0, SEEK_SET);
if (sb_bytenr > dev_size) {
fprintf(stderr, "Superblock bytenr is larger than device size\n");
return -EINVAL;
}
ret = btrfs_scan_one_device(fd, path, fs_devices,
&total_devs, sb_bytenr, super_recover);
if (ret) {
fprintf(stderr, "No valid Btrfs found on %s\n", path);
return ret;
}
if (!skip_devices && total_devs != 1) {
ret = btrfs_scan_lblkid();
if (ret)
return ret;
}
return 0;
}
int btrfs_setup_chunk_tree_and_device_map(struct btrfs_fs_info *fs_info,
u64 chunk_root_bytenr)
{
struct btrfs_super_block *sb = fs_info->super_copy;
u32 sectorsize;
u32 nodesize;
u32 leafsize;
u32 blocksize;
u32 stripesize;
u64 generation;
int ret;
nodesize = btrfs_super_nodesize(sb);
leafsize = btrfs_super_leafsize(sb);
sectorsize = btrfs_super_sectorsize(sb);
stripesize = btrfs_super_stripesize(sb);
__setup_root(nodesize, leafsize, sectorsize, stripesize,
fs_info->chunk_root, fs_info, BTRFS_CHUNK_TREE_OBJECTID);
ret = btrfs_read_sys_array(fs_info->chunk_root);
if (ret)
return ret;
blocksize = fs_info->chunk_root->nodesize;
generation = btrfs_super_chunk_root_generation(sb);
if (chunk_root_bytenr && !IS_ALIGNED(chunk_root_bytenr,
btrfs_super_sectorsize(sb))) {
warning("chunk_root_bytenr %llu is unaligned to %u, ignore it",
chunk_root_bytenr, btrfs_super_sectorsize(sb));
chunk_root_bytenr = 0;
}
if (!chunk_root_bytenr)
chunk_root_bytenr = btrfs_super_chunk_root(sb);
else
generation = 0;
fs_info->chunk_root->node = read_tree_block(fs_info->chunk_root,
chunk_root_bytenr,
blocksize, generation);
if (!extent_buffer_uptodate(fs_info->chunk_root->node)) {
if (fs_info->ignore_chunk_tree_error) {
warning("cannot read chunk root, continue anyway");
fs_info->chunk_root = NULL;
return 0;
} else {
error("cannot read chunk root");
return -EIO;
}
}
if (!(btrfs_super_flags(sb) & BTRFS_SUPER_FLAG_METADUMP)) {
ret = btrfs_read_chunk_tree(fs_info->chunk_root);
if (ret) {
fprintf(stderr, "Couldn't read chunk tree\n");
return ret;
}
}
return 0;
}
static struct btrfs_fs_info *__open_ctree_fd(int fp, const char *path,
u64 sb_bytenr,
u64 root_tree_bytenr,
u64 chunk_root_bytenr,
enum btrfs_open_ctree_flags flags)
{
struct btrfs_fs_info *fs_info;
struct btrfs_super_block *disk_super;
struct btrfs_fs_devices *fs_devices = NULL;
struct extent_buffer *eb;
int ret;
int oflags;
if (sb_bytenr == 0)
sb_bytenr = BTRFS_SUPER_INFO_OFFSET;
/* try to drop all the caches */
if (posix_fadvise(fp, 0, 0, POSIX_FADV_DONTNEED))
fprintf(stderr, "Warning, could not drop caches\n");
fs_info = btrfs_new_fs_info(flags & OPEN_CTREE_WRITES, sb_bytenr);
if (!fs_info) {
fprintf(stderr, "Failed to allocate memory for fs_info\n");
return NULL;
}
if (flags & OPEN_CTREE_RESTORE)
fs_info->on_restoring = 1;
if (flags & OPEN_CTREE_SUPPRESS_CHECK_BLOCK_ERRORS)
fs_info->suppress_check_block_errors = 1;
if (flags & OPEN_CTREE_IGNORE_FSID_MISMATCH)
fs_info->ignore_fsid_mismatch = 1;
if (flags & OPEN_CTREE_IGNORE_CHUNK_TREE_ERROR)
fs_info->ignore_chunk_tree_error = 1;
ret = btrfs_scan_fs_devices(fp, path, &fs_devices, sb_bytenr,
(flags & OPEN_CTREE_RECOVER_SUPER),
(flags & OPEN_CTREE_NO_DEVICES));
if (ret)
goto out;
fs_info->fs_devices = fs_devices;
if (flags & OPEN_CTREE_WRITES)
oflags = O_RDWR;
else
oflags = O_RDONLY;
if (flags & OPEN_CTREE_EXCLUSIVE)
oflags |= O_EXCL;
ret = btrfs_open_devices(fs_devices, oflags);
if (ret)
goto out;
disk_super = fs_info->super_copy;
if (flags & OPEN_CTREE_RECOVER_SUPER)
ret = btrfs_read_dev_super(fs_devices->latest_bdev,
disk_super, sb_bytenr, 1);
else
ret = btrfs_read_dev_super(fp, disk_super, sb_bytenr, 0);
if (ret) {
printk("No valid btrfs found\n");
goto out_devices;
}
if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_CHANGING_FSID &&
!fs_info->ignore_fsid_mismatch) {
fprintf(stderr, "ERROR: Filesystem UUID change in progress\n");
goto out_devices;
}
memcpy(fs_info->fsid, &disk_super->fsid, BTRFS_FSID_SIZE);
ret = btrfs_check_fs_compatibility(fs_info->super_copy,
flags & OPEN_CTREE_WRITES);
if (ret)
goto out_devices;
ret = btrfs_setup_chunk_tree_and_device_map(fs_info, chunk_root_bytenr);
if (ret)
goto out_chunk;
/* Chunk tree root is unable to read, return directly */
if (!fs_info->chunk_root)
return fs_info;
eb = fs_info->chunk_root->node;
read_extent_buffer(eb, fs_info->chunk_tree_uuid,
btrfs_header_chunk_tree_uuid(eb),
BTRFS_UUID_SIZE);
ret = btrfs_setup_all_roots(fs_info, root_tree_bytenr, flags);
if (ret && !(flags & __OPEN_CTREE_RETURN_CHUNK_ROOT) &&
!fs_info->ignore_chunk_tree_error)
goto out_chunk;
return fs_info;
out_chunk:
btrfs_release_all_roots(fs_info);
btrfs_cleanup_all_caches(fs_info);
out_devices:
btrfs_close_devices(fs_devices);
out:
btrfs_free_fs_info(fs_info);
return NULL;
}
struct btrfs_fs_info *open_ctree_fs_info(const char *filename,
u64 sb_bytenr, u64 root_tree_bytenr,
u64 chunk_root_bytenr,
enum btrfs_open_ctree_flags flags)
{
int fp;
int ret;
struct btrfs_fs_info *info;
int oflags = O_CREAT | O_RDWR;
struct stat st;
ret = stat(filename, &st);
if (ret < 0) {
error("cannot stat '%s': %s", filename, strerror(errno));
return NULL;
}
if (!(((st.st_mode & S_IFMT) == S_IFREG) || ((st.st_mode & S_IFMT) == S_IFBLK))) {
error("not a regular file or block device: %s", filename);
return NULL;
}
if (!(flags & OPEN_CTREE_WRITES))
oflags = O_RDONLY;
fp = open(filename, oflags, 0600);
if (fp < 0) {
error("cannot open '%s': %s", filename, strerror(errno));
return NULL;
}
info = __open_ctree_fd(fp, filename, sb_bytenr, root_tree_bytenr,
chunk_root_bytenr, flags);
close(fp);
return info;
}
struct btrfs_root *open_ctree(const char *filename, u64 sb_bytenr,
enum btrfs_open_ctree_flags flags)
{
struct btrfs_fs_info *info;
/* This flags may not return fs_info with any valid root */
BUG_ON(flags & OPEN_CTREE_IGNORE_CHUNK_TREE_ERROR);
info = open_ctree_fs_info(filename, sb_bytenr, 0, 0, flags);
if (!info)
return NULL;
if (flags & __OPEN_CTREE_RETURN_CHUNK_ROOT)
return info->chunk_root;
return info->fs_root;
}
struct btrfs_root *open_ctree_fd(int fp, const char *path, u64 sb_bytenr,
enum btrfs_open_ctree_flags flags)
{
struct btrfs_fs_info *info;
/* This flags may not return fs_info with any valid root */
BUG_ON(flags & OPEN_CTREE_IGNORE_CHUNK_TREE_ERROR);
info = __open_ctree_fd(fp, path, sb_bytenr, 0, 0, flags);
if (!info)
return NULL;
if (flags & __OPEN_CTREE_RETURN_CHUNK_ROOT)
return info->chunk_root;
return info->fs_root;
}
/*
* Check if the super is valid:
* - nodesize/sectorsize - minimum, maximum, alignment
* - tree block starts - alignment
* - number of devices - something sane
* - sys array size - maximum
*/
static int check_super(struct btrfs_super_block *sb)
{
char result[BTRFS_CSUM_SIZE];
u32 crc;
u16 csum_type;
int csum_size;
if (btrfs_super_magic(sb) != BTRFS_MAGIC) {
error("superblock magic doesn't match");
return -EIO;
}
csum_type = btrfs_super_csum_type(sb);
if (csum_type >= ARRAY_SIZE(btrfs_csum_sizes)) {
error("unsupported checksum algorithm %u\n", csum_type);
return -EIO;
}
csum_size = btrfs_csum_sizes[csum_type];
crc = ~(u32)0;
crc = btrfs_csum_data(NULL, (char *)sb + BTRFS_CSUM_SIZE, crc,
BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
btrfs_csum_final(crc, result);
if (memcmp(result, sb->csum, csum_size)) {
error("superblock checksum mismatch");
return -EIO;
}
if (btrfs_super_root_level(sb) >= BTRFS_MAX_LEVEL) {
error("tree_root level too big: %d >= %d",
btrfs_super_root_level(sb), BTRFS_MAX_LEVEL);
goto error_out;
}
if (btrfs_super_chunk_root_level(sb) >= BTRFS_MAX_LEVEL) {
error("chunk_root level too big: %d >= %d",
btrfs_super_chunk_root_level(sb), BTRFS_MAX_LEVEL);
goto error_out;
}
if (btrfs_super_log_root_level(sb) >= BTRFS_MAX_LEVEL) {
error("log_root level too big: %d >= %d",
btrfs_super_log_root_level(sb), BTRFS_MAX_LEVEL);
goto error_out;
}
if (!IS_ALIGNED(btrfs_super_root(sb), 4096)) {
error("tree_root block unaligned: %llu", btrfs_super_root(sb));
goto error_out;
}
if (!IS_ALIGNED(btrfs_super_chunk_root(sb), 4096)) {
error("chunk_root block unaligned: %llu",
btrfs_super_chunk_root(sb));
goto error_out;
}
if (!IS_ALIGNED(btrfs_super_log_root(sb), 4096)) {
error("log_root block unaligned: %llu",
btrfs_super_log_root(sb));
goto error_out;
}
if (btrfs_super_nodesize(sb) < 4096) {
error("nodesize too small: %u < 4096",
btrfs_super_nodesize(sb));
goto error_out;
}
if (!IS_ALIGNED(btrfs_super_nodesize(sb), 4096)) {
error("nodesize unaligned: %u", btrfs_super_nodesize(sb));
goto error_out;
}
if (btrfs_super_sectorsize(sb) < 4096) {
error("sectorsize too small: %u < 4096",
btrfs_super_sectorsize(sb));
goto error_out;
}
if (!IS_ALIGNED(btrfs_super_sectorsize(sb), 4096)) {
error("sectorsize unaligned: %u", btrfs_super_sectorsize(sb));
goto error_out;
}
if (btrfs_super_total_bytes(sb) == 0) {
error("invalid total_bytes 0");
goto error_out;
}
if (btrfs_super_bytes_used(sb) < 6 * btrfs_super_nodesize(sb)) {
error("invalid bytes_used %llu", btrfs_super_bytes_used(sb));
goto error_out;
}
if (btrfs_super_stripesize(sb) != 4096) {
error("invalid stripesize %u", btrfs_super_stripesize(sb));
goto error_out;
}
if (memcmp(sb->fsid, sb->dev_item.fsid, BTRFS_UUID_SIZE) != 0) {
char fsid[BTRFS_UUID_UNPARSED_SIZE];
char dev_fsid[BTRFS_UUID_UNPARSED_SIZE];
uuid_unparse(sb->fsid, fsid);
uuid_unparse(sb->dev_item.fsid, dev_fsid);
error("dev_item UUID does not match fsid: %s != %s",
dev_fsid, fsid);
goto error_out;
}
/*
* Hint to catch really bogus numbers, bitflips or so
*/
if (btrfs_super_num_devices(sb) > (1UL << 31)) {
warning("suspicious number of devices: %llu",
btrfs_super_num_devices(sb));
}
if (btrfs_super_num_devices(sb) == 0) {
error("number of devices is 0");
goto error_out;
}
/*
* Obvious sys_chunk_array corruptions, it must hold at least one key
* and one chunk
*/
if (btrfs_super_sys_array_size(sb) > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE) {
error("system chunk array too big %u > %u",
btrfs_super_sys_array_size(sb),
BTRFS_SYSTEM_CHUNK_ARRAY_SIZE);
goto error_out;
}
if (btrfs_super_sys_array_size(sb) < sizeof(struct btrfs_disk_key)
+ sizeof(struct btrfs_chunk)) {
error("system chunk array too small %u < %lu",
btrfs_super_sys_array_size(sb),
sizeof(struct btrfs_disk_key) +
sizeof(struct btrfs_chunk));
goto error_out;
}
return 0;
error_out:
error("superblock checksum matches but it has invalid members");
return -EIO;
}
int btrfs_read_dev_super(int fd, struct btrfs_super_block *sb, u64 sb_bytenr,
int super_recover)
{
u8 fsid[BTRFS_FSID_SIZE];
int fsid_is_initialized = 0;
char tmp[BTRFS_SUPER_INFO_SIZE];
struct btrfs_super_block *buf = (struct btrfs_super_block *)tmp;
int i;
int ret;
int max_super = super_recover ? BTRFS_SUPER_MIRROR_MAX : 1;
u64 transid = 0;
u64 bytenr;
if (sb_bytenr != BTRFS_SUPER_INFO_OFFSET) {
ret = pread64(fd, buf, BTRFS_SUPER_INFO_SIZE, sb_bytenr);
if (ret < BTRFS_SUPER_INFO_SIZE)
return -1;
if (btrfs_super_bytenr(buf) != sb_bytenr)
return -1;
if (check_super(buf))
return -1;
memcpy(sb, buf, BTRFS_SUPER_INFO_SIZE);
return 0;
}
/*
* we would like to check all the supers, but that would make
* a btrfs mount succeed after a mkfs from a different FS.
* So, we need to add a special mount option to scan for
* later supers, using BTRFS_SUPER_MIRROR_MAX instead
*/
for (i = 0; i < max_super; i++) {
bytenr = btrfs_sb_offset(i);
ret = pread64(fd, buf, BTRFS_SUPER_INFO_SIZE, bytenr);
if (ret < BTRFS_SUPER_INFO_SIZE)
break;
if (btrfs_super_bytenr(buf) != bytenr )
continue;
/* if magic is NULL, the device was removed */
if (btrfs_super_magic(buf) == 0 && i == 0)
break;
if (check_super(buf))
continue;
if (!fsid_is_initialized) {
memcpy(fsid, buf->fsid, sizeof(fsid));
fsid_is_initialized = 1;
} else if (memcmp(fsid, buf->fsid, sizeof(fsid))) {
/*
* the superblocks (the original one and
* its backups) contain data of different
* filesystems -> the super cannot be trusted
*/
continue;
}
if (btrfs_super_generation(buf) > transid) {
memcpy(sb, buf, BTRFS_SUPER_INFO_SIZE);
transid = btrfs_super_generation(buf);
}
}
return transid > 0 ? 0 : -1;
}
static int write_dev_supers(struct btrfs_root *root,
struct btrfs_super_block *sb,
struct btrfs_device *device)
{
u64 bytenr;
u32 crc;
int i, ret;
if (root->fs_info->super_bytenr != BTRFS_SUPER_INFO_OFFSET) {
btrfs_set_super_bytenr(sb, root->fs_info->super_bytenr);
crc = ~(u32)0;
crc = btrfs_csum_data(NULL, (char *)sb + BTRFS_CSUM_SIZE, crc,
BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
btrfs_csum_final(crc, (char *)&sb->csum[0]);
/*
* super_copy is BTRFS_SUPER_INFO_SIZE bytes and is
* zero filled, we can use it directly
*/
ret = pwrite64(device->fd, root->fs_info->super_copy,
BTRFS_SUPER_INFO_SIZE,
root->fs_info->super_bytenr);
if (ret != BTRFS_SUPER_INFO_SIZE)
goto write_err;
return 0;
}
for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
bytenr = btrfs_sb_offset(i);
if (bytenr + BTRFS_SUPER_INFO_SIZE > device->total_bytes)
break;
btrfs_set_super_bytenr(sb, bytenr);
crc = ~(u32)0;
crc = btrfs_csum_data(NULL, (char *)sb + BTRFS_CSUM_SIZE, crc,
BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
btrfs_csum_final(crc, (char *)&sb->csum[0]);
/*
* super_copy is BTRFS_SUPER_INFO_SIZE bytes and is
* zero filled, we can use it directly
*/
ret = pwrite64(device->fd, root->fs_info->super_copy,
BTRFS_SUPER_INFO_SIZE, bytenr);
if (ret != BTRFS_SUPER_INFO_SIZE)
goto write_err;
}
return 0;
write_err:
if (ret > 0)
fprintf(stderr, "WARNING: failed to write all sb data\n");
else
fprintf(stderr, "WARNING: failed to write sb: %s\n",
strerror(errno));
return ret;
}
int write_all_supers(struct btrfs_root *root)
{
struct list_head *cur;
struct list_head *head = &root->fs_info->fs_devices->devices;
struct btrfs_device *dev;
struct btrfs_super_block *sb;
struct btrfs_dev_item *dev_item;
int ret;
u64 flags;
sb = root->fs_info->super_copy;
dev_item = &sb->dev_item;
list_for_each(cur, head) {
dev = list_entry(cur, struct btrfs_device, dev_list);
if (!dev->writeable)
continue;
btrfs_set_stack_device_generation(dev_item, 0);
btrfs_set_stack_device_type(dev_item, dev->type);
btrfs_set_stack_device_id(dev_item, dev->devid);
btrfs_set_stack_device_total_bytes(dev_item, dev->total_bytes);
btrfs_set_stack_device_bytes_used(dev_item, dev->bytes_used);
btrfs_set_stack_device_io_align(dev_item, dev->io_align);
btrfs_set_stack_device_io_width(dev_item, dev->io_width);
btrfs_set_stack_device_sector_size(dev_item, dev->sector_size);
memcpy(dev_item->uuid, dev->uuid, BTRFS_UUID_SIZE);
memcpy(dev_item->fsid, dev->fs_devices->fsid, BTRFS_UUID_SIZE);
flags = btrfs_super_flags(sb);
btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN);
ret = write_dev_supers(root, sb, dev);
BUG_ON(ret);
}
return 0;
}
int write_ctree_super(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
int ret;
struct btrfs_root *tree_root = root->fs_info->tree_root;
struct btrfs_root *chunk_root = root->fs_info->chunk_root;
if (root->fs_info->readonly)
return 0;
btrfs_set_super_generation(root->fs_info->super_copy,
trans->transid);
btrfs_set_super_root(root->fs_info->super_copy,
tree_root->node->start);
btrfs_set_super_root_level(root->fs_info->super_copy,
btrfs_header_level(tree_root->node));
btrfs_set_super_chunk_root(root->fs_info->super_copy,
chunk_root->node->start);
btrfs_set_super_chunk_root_level(root->fs_info->super_copy,
btrfs_header_level(chunk_root->node));
btrfs_set_super_chunk_root_generation(root->fs_info->super_copy,
btrfs_header_generation(chunk_root->node));
ret = write_all_supers(root);
if (ret)
fprintf(stderr, "failed to write new super block err %d\n", ret);
return ret;
}
int close_ctree_fs_info(struct btrfs_fs_info *fs_info)
{
int ret;
struct btrfs_trans_handle *trans;
struct btrfs_root *root = fs_info->tree_root;
if (fs_info->last_trans_committed !=
fs_info->generation) {
BUG_ON(!root);
trans = btrfs_start_transaction(root, 1);
btrfs_commit_transaction(trans, root);
trans = btrfs_start_transaction(root, 1);
ret = commit_tree_roots(trans, fs_info);
BUG_ON(ret);
ret = __commit_transaction(trans, root);
BUG_ON(ret);
write_ctree_super(trans, root);
btrfs_free_transaction(root, trans);
}
btrfs_free_block_groups(fs_info);
free_fs_roots_tree(&fs_info->fs_root_tree);
btrfs_release_all_roots(fs_info);
btrfs_close_devices(fs_info->fs_devices);
btrfs_cleanup_all_caches(fs_info);
btrfs_free_fs_info(fs_info);
return 0;
}
int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
struct extent_buffer *eb)
{
return clear_extent_buffer_dirty(eb);
}
int wait_on_tree_block_writeback(struct btrfs_root *root,
struct extent_buffer *eb)
{
return 0;
}
void btrfs_mark_buffer_dirty(struct extent_buffer *eb)
{
set_extent_buffer_dirty(eb);
}
int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid)
{
int ret;
ret = extent_buffer_uptodate(buf);
if (!ret)
return ret;
ret = verify_parent_transid(buf->tree, buf, parent_transid, 1);
return !ret;
}
int btrfs_set_buffer_uptodate(struct extent_buffer *eb)
{
return set_extent_buffer_uptodate(eb);
}
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