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btrfs-progs/disk-io.c

2013 lines
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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 "kernel-lib/radix-tree.h"
#include "ctree.h"
#include "disk-io.h"
#include "volumes.h"
#include "transaction.h"
#include "crypto/crc32c.h"
#include "common/utils.h"
#include "print-tree.h"
#include "common/rbtree-utils.h"
#include "common/device-scan.h"
#include "crypto/hash.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 = fs_info->fs_devices;
u32 nodesize = fs_info->nodesize;
bool fsid_match = false;
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;
/* Only leaf can be empty */
if (btrfs_header_nritems(buf) == 0 &&
btrfs_header_level(buf) != 0)
return BTRFS_BAD_NRITEMS;
while (fs_devices) {
/*
* Checking the incompat flag is only valid for the current
* fs. For seed devices it's forbidden to have their uuid
* changed so reading ->fsid in this case is fine
*/
if (fs_devices == fs_info->fs_devices &&
btrfs_fs_incompat(fs_info, METADATA_UUID))
fsid_match = !memcmp_extent_buffer(buf,
fs_devices->metadata_uuid,
btrfs_header_fsid(),
BTRFS_FSID_SIZE);
else
fsid_match = !memcmp_extent_buffer(buf,
fs_devices->fsid,
btrfs_header_fsid(),
BTRFS_FSID_SIZE);
if (fs_info->ignore_fsid_mismatch || fsid_match) {
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];
if (!err)
return;
fprintf(stderr, "bad tree block %llu, ", eb->start);
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->fs_devices->metadata_uuid, 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 > %d\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;
}
}
int btrfs_csum_data(u16 csum_type, const u8 *data, u8 *out, size_t len)
{
memset(out, 0, BTRFS_CSUM_SIZE);
switch (csum_type) {
case BTRFS_CSUM_TYPE_CRC32:
return hash_crc32c(data, len, out);
case BTRFS_CSUM_TYPE_XXHASH:
return hash_xxhash(data, len, out);
case BTRFS_CSUM_TYPE_SHA256:
return hash_sha256(data, len, out);
case BTRFS_CSUM_TYPE_BLAKE2:
return hash_blake2b(data, len, out);
default:
fprintf(stderr, "ERROR: unknown csum type: %d\n", csum_type);
ASSERT(0);
}
return -1;
}
static int __csum_tree_block_size(struct extent_buffer *buf, u16 csum_size,
int verify, int silent, u16 csum_type)
{
u8 result[BTRFS_CSUM_SIZE];
u32 len;
len = buf->len - BTRFS_CSUM_SIZE;
btrfs_csum_data(csum_type, (u8 *)buf->data + BTRFS_CSUM_SIZE,
result, len);
if (verify) {
if (memcmp_extent_buffer(buf, result, 0, csum_size)) {
/* FIXME: format */
if (!silent)
printk("checksum verify failed on %llu found %08X wanted %08X\n",
(unsigned long long)buf->start,
result[0],
buf->data[0]);
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,
u16 csum_type)
{
return __csum_tree_block_size(buf, csum_size, verify, 0, csum_type);
}
int verify_tree_block_csum_silent(struct extent_buffer *buf, u16 csum_size,
u16 csum_type)
{
return __csum_tree_block_size(buf, csum_size, 1, 1, csum_type);
}
int csum_tree_block(struct btrfs_fs_info *fs_info,
struct extent_buffer *buf, int verify)
{
u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
u16 csum_type = btrfs_super_csum_type(fs_info->super_copy);
if (verify && fs_info->suppress_check_block_errors)
return verify_tree_block_csum_silent(buf, csum_size, csum_type);
return csum_tree_block_size(buf, csum_size, verify, csum_type);
}
struct extent_buffer *btrfs_find_tree_block(struct btrfs_fs_info *fs_info,
u64 bytenr, u32 blocksize)
{
return find_extent_buffer(&fs_info->extent_cache,
bytenr, blocksize);
}
struct extent_buffer* btrfs_find_create_tree_block(
struct btrfs_fs_info *fs_info, u64 bytenr)
{
return alloc_extent_buffer(fs_info, bytenr, fs_info->nodesize);
}
void readahead_tree_block(struct btrfs_fs_info *fs_info, u64 bytenr,
u64 parent_transid)
{
struct extent_buffer *eb;
u64 length;
struct btrfs_multi_bio *multi = NULL;
struct btrfs_device *device;
eb = btrfs_find_tree_block(fs_info, bytenr, fs_info->nodesize);
if (!(eb && btrfs_buffer_uptodate(eb, parent_transid)) &&
!btrfs_map_block(fs_info, READ, bytenr, &length, &multi, 0,
NULL)) {
device = multi->stripes[0].dev;
device->total_ios++;
readahead(device->fd, multi->stripes[0].physical,
fs_info->nodesize);
}
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(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, 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(struct btrfs_fs_info *fs_info, u64 bytenr,
u64 parent_transid)
{
int ret;
struct extent_buffer *eb;
u64 best_transid = 0;
u32 sectorsize = fs_info->sectorsize;
int mirror_num = 1;
int good_mirror = 0;
int candidate_mirror = 0;
int num_copies;
int ignore = 0;
/*
* Don't even try to create tree block for unaligned tree block
* bytenr.
* Such unaligned tree block will free overlapping extent buffer,
* causing use-after-free bugs for fuzzed images.
*/
if (bytenr < sectorsize || !IS_ALIGNED(bytenr, sectorsize)) {
error("tree block bytenr %llu is not aligned to sectorsize %u",
bytenr, sectorsize);
return ERR_PTR(-EIO);
}
eb = btrfs_find_create_tree_block(fs_info, bytenr);
if (!eb)
return ERR_PTR(-ENOMEM);
if (btrfs_buffer_uptodate(eb, parent_transid))
return eb;
num_copies = btrfs_num_copies(fs_info, eb->start, eb->len);
while (1) {
ret = read_whole_eb(fs_info, eb, mirror_num);
if (ret == 0 && csum_tree_block(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++;
}
/*
* check_tree_block() is less strict to allow btrfs
* check to get raw eb with bad key order and fix it.
* But we still need to try to get a good copy if
* possible, or bad key order can go into tools like
* btrfs ins dump-tree.
*/
if (btrfs_header_level(eb))
ret = btrfs_check_node(fs_info, NULL, eb);
else
ret = btrfs_check_leaf(fs_info, NULL, eb);
if (!ret || candidate_mirror == mirror_num) {
btrfs_set_buffer_uptodate(eb);
return eb;
}
if (candidate_mirror <= 0)
candidate_mirror = mirror_num;
}
if (ignore) {
if (candidate_mirror > 0) {
mirror_num = candidate_mirror;
continue;
}
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;
}
if (num_copies == 1) {
ignore = 1;
continue;
}
if (btrfs_header_generation(eb) > best_transid) {
best_transid = btrfs_header_generation(eb);
good_mirror = mirror_num;
}
mirror_num++;
if (mirror_num > num_copies) {
if (candidate_mirror > 0)
mirror_num = candidate_mirror;
else
mirror_num = good_mirror;
ignore = 1;
continue;
}
}
/*
* We failed to read this tree block, it be should deleted right now
* to avoid stale cache populate the cache.
*/
free_extent_buffer_nocache(eb);
return ERR_PTR(ret);
}
int read_extent_data(struct btrfs_fs_info *fs_info, char *data, u64 logical,
u64 *len, int mirror)
{
u64 offset = 0;
struct btrfs_multi_bio *multi = NULL;
struct btrfs_device *device;
int ret = 0;
u64 max_len = *len;
ret = btrfs_map_block(fs_info, 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 (*len > max_len)
*len = max_len;
if (device->fd < 0) {
ret = -EIO;
goto err;
}
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_fs_info *fs_info, 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(fs_info, WRITE, eb->start, &length,
&multi, 0, &raid_map);
if (raid_map) {
ret = write_raid56_with_parity(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_fs_info *fs_info,
struct extent_buffer *eb)
{
if (check_tree_block(fs_info, eb)) {
print_tree_block_error(fs_info, eb,
check_tree_block(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(fs_info, eb, 0);
return write_and_map_eb(fs_info, eb);
}
void btrfs_setup_root(struct btrfs_root *root, struct btrfs_fs_info *fs_info,
u64 objectid)
{
root->node = NULL;
root->commit_root = NULL;
root->ref_cows = 0;
root->track_dirty = 0;
root->fs_info = fs_info;
root->objectid = objectid;
root->last_trans = 0;
root->last_inode_alloc = 0;
INIT_LIST_HEAD(&root->dirty_list);
INIT_LIST_HEAD(&root->unaligned_extent_recs);
memset(&root->root_key, 0, sizeof(root->root_key));
memset(&root->root_item, 0, sizeof(root->root_item));
root->root_key.objectid = objectid;
}
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;
u64 generation;
btrfs_setup_root(root, fs_info, objectid);
ret = btrfs_find_last_root(tree_root, objectid,
&root->root_item, &root->root_key);
if (ret)
return ret;
generation = btrfs_root_generation(&root->root_item);
root->node = read_tree_block(fs_info,
btrfs_root_bytenr(&root->root_item), 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)
{
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;
}
btrfs_setup_root(log_root, fs_info,
BTRFS_TREE_LOG_OBJECTID);
log_root->node = read_tree_block(fs_info, blocknr,
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;
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;
}
btrfs_setup_root(root, fs_info,
location->objectid);
path = btrfs_alloc_path();
if (!path) {
free(root);
return ERR_PTR(-ENOMEM);
}
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);
root->node = read_tree_block(fs_info,
btrfs_root_bytenr(&root->root_item), 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;
}
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_UUID_TREE_OBJECTID)
return fs_info->uuid_root ? fs_info->uuid_root : ERR_PTR(-ENOENT);
if (location->objectid == BTRFS_QUOTA_TREE_OBJECTID)
return fs_info->quota_enabled ? fs_info->quota_root :
ERR_PTR(-ENOENT);
if (location->objectid == BTRFS_FREE_SPACE_TREE_OBJECTID)
return fs_info->free_space_root ? fs_info->free_space_root :
ERR_PTR(-ENOENT);
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)
{
if (fs_info->quota_root)
free(fs_info->quota_root);
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->free_space_root);
free(fs_info->uuid_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->uuid_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->uuid_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->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,
unsigned int flags)
{
u64 features;
features = btrfs_super_incompat_flags(sb) &
~BTRFS_FEATURE_INCOMPAT_SUPP;
if (features) {
printk("couldn't open because of unsupported "
"option features (%llx).\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);
if (flags & OPEN_CTREE_WRITES) {
if (flags & OPEN_CTREE_INVALIDATE_FST) {
/* Clear the FREE_SPACE_TREE_VALID bit on disk... */
features &= ~BTRFS_FEATURE_COMPAT_RO_FREE_SPACE_TREE_VALID;
btrfs_set_super_compat_ro_flags(sb, features);
/* ... and ignore the free space tree bit. */
features &= ~BTRFS_FEATURE_COMPAT_RO_FREE_SPACE_TREE;
}
if (features & ~BTRFS_FEATURE_COMPAT_RO_SUPP) {
printk("couldn't open RDWR because of unsupported "
"option features (0x%llx)\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,
unsigned flags,
struct btrfs_root *info_root,
u64 objectid, char *str)
{
struct btrfs_root *root = fs_info->tree_root;
int ret;
ret = find_and_setup_root(root, fs_info, objectid, info_root);
if (ret) {
if (!(flags & OPEN_CTREE_PARTIAL)) {
error("could not setup %s tree", str);
return -EIO;
}
warning("could not setup %s tree, skipping it", str);
/*
* 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);
if (!info_root->node)
return -ENOMEM;
clear_extent_buffer_uptodate(info_root->node);
}
return 0;
}
int btrfs_setup_all_roots(struct btrfs_fs_info *fs_info, u64 root_tree_bytenr,
unsigned flags)
{
struct btrfs_super_block *sb = fs_info->super_copy;
struct btrfs_root *root;
struct btrfs_key key;
u64 generation;
int ret;
root = fs_info->tree_root;
btrfs_setup_root(root, fs_info, BTRFS_ROOT_TREE_OBJECTID);
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(fs_info, root_tree_bytenr, 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_UUID_TREE_OBJECTID,
fs_info->uuid_root);
if (ret) {
free(fs_info->uuid_root);
fs_info->uuid_root = NULL;
} else {
fs_info->uuid_root->track_dirty = 1;
}
ret = find_and_setup_root(root, fs_info, BTRFS_QUOTA_TREE_OBJECTID,
fs_info->quota_root);
if (ret) {
free(fs_info->quota_root);
fs_info->quota_root = NULL;
} else {
fs_info->quota_enabled = 1;
}
if (btrfs_fs_compat_ro(fs_info, 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)) {
ret = btrfs_read_block_groups(fs_info);
/*
* If we don't find any blockgroups (ENOENT) we're either
* restoring or creating the filesystem, where it's expected,
* anything else is error
*/
if (ret < 0 && ret != -ENOENT) {
errno = -ret;
error("failed to read block groups: %m");
return ret;
}
}
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);
if (fs_info->uuid_root)
free_extent_buffer(fs_info->uuid_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->extent_ins);
}
int btrfs_scan_fs_devices(int fd, const char *path,
struct btrfs_fs_devices **fs_devices,
u64 sb_bytenr, unsigned sbflags,
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) {
error("superblock bytenr %llu is larger than device size %llu",
(unsigned long long)sb_bytenr,
(unsigned long long)dev_size);
return -EINVAL;
}
ret = btrfs_scan_one_device(fd, path, fs_devices,
&total_devs, sb_bytenr, sbflags);
if (ret) {
fprintf(stderr, "No valid Btrfs found on %s\n", path);
return ret;
}
if (!skip_devices && total_devs != 1) {
ret = btrfs_scan_devices();
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;
u64 generation;
int ret;
btrfs_setup_root(fs_info->chunk_root, fs_info,
BTRFS_CHUNK_TREE_OBJECTID);
ret = btrfs_read_sys_array(fs_info);
if (ret)
return ret;
generation = btrfs_super_chunk_root_generation(sb);
if (chunk_root_bytenr && !IS_ALIGNED(chunk_root_bytenr,
fs_info->sectorsize)) {
warning("chunk_root_bytenr %llu is unaligned to %u, ignore it",
chunk_root_bytenr, fs_info->sectorsize);
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_bytenr,
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);
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,
unsigned 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;
unsigned sbflags = SBREAD_DEFAULT;
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;
if ((flags & OPEN_CTREE_RECOVER_SUPER)
&& (flags & OPEN_CTREE_TEMPORARY_SUPER)) {
fprintf(stderr,
"cannot open a filesystem with temporary super block for recovery");
goto out;
}
if (flags & OPEN_CTREE_TEMPORARY_SUPER)
sbflags = SBREAD_TEMPORARY;
if (flags & OPEN_CTREE_IGNORE_FSID_MISMATCH)
sbflags |= SBREAD_IGNORE_FSID_MISMATCH;
ret = btrfs_scan_fs_devices(fp, path, &fs_devices, sb_bytenr, sbflags,
(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, SBREAD_RECOVER);
else
ret = btrfs_read_dev_super(fp, disk_super, sb_bytenr,
sbflags);
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;
}
ASSERT(!memcmp(disk_super->fsid, fs_devices->fsid, BTRFS_FSID_SIZE));
if (btrfs_fs_incompat(fs_info, METADATA_UUID))
ASSERT(!memcmp(disk_super->metadata_uuid,
fs_devices->metadata_uuid, BTRFS_FSID_SIZE));
fs_info->sectorsize = btrfs_super_sectorsize(disk_super);
fs_info->nodesize = btrfs_super_nodesize(disk_super);
fs_info->stripesize = btrfs_super_stripesize(disk_super);
ret = btrfs_check_fs_compatibility(fs_info->super_copy, flags);
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,
unsigned flags)
{
int fp;
int ret;
struct btrfs_fs_info *info;
int oflags = O_RDWR;
struct stat st;
ret = stat(filename, &st);
if (ret < 0) {
error("cannot stat '%s': %m", filename);
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);
if (fp < 0) {
error("cannot open '%s': %m", filename);
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,
unsigned 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,
unsigned flags)
{
struct btrfs_fs_info *info;
/* This flags may not return fs_info with any valid root */
if (flags & OPEN_CTREE_IGNORE_CHUNK_TREE_ERROR) {
error("invalid open_ctree flags: 0x%llx",
(unsigned long long)flags);
return NULL;
}
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
*/
int btrfs_check_super(struct btrfs_super_block *sb, unsigned sbflags)
{
u8 result[BTRFS_CSUM_SIZE];
u16 csum_type;
int csum_size;
u8 *metadata_uuid;
if (btrfs_super_magic(sb) != BTRFS_MAGIC) {
if (btrfs_super_magic(sb) == BTRFS_MAGIC_TEMPORARY) {
if (!(sbflags & SBREAD_TEMPORARY)) {
error("superblock magic doesn't match");
return -EIO;
}
}
}
csum_type = btrfs_super_csum_type(sb);
if (csum_type >= btrfs_super_num_csums()) {
error("unsupported checksum algorithm %u", csum_type);
return -EIO;
}
csum_size = btrfs_super_csum_size(sb);
btrfs_csum_data(csum_type, (u8 *)sb + BTRFS_CSUM_SIZE,
result, BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
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)
&& (btrfs_super_stripesize(sb) != btrfs_super_sectorsize(sb))) {
error("invalid stripesize %u", btrfs_super_stripesize(sb));
goto error_out;
}
if (btrfs_super_incompat_flags(sb) & BTRFS_FEATURE_INCOMPAT_METADATA_UUID)
metadata_uuid = sb->metadata_uuid;
else
metadata_uuid = sb->fsid;
if (memcmp(metadata_uuid, sb->dev_item.fsid, BTRFS_FSID_SIZE) != 0) {
char fsid[BTRFS_UUID_UNPARSED_SIZE];
char dev_fsid[BTRFS_UUID_UNPARSED_SIZE];
uuid_unparse(sb->metadata_uuid, fsid);
uuid_unparse(sb->dev_item.fsid, dev_fsid);
if (sbflags & SBREAD_IGNORE_FSID_MISMATCH) {
warning("ignored: dev_item fsid mismatch: %s != %s",
dev_fsid, fsid);
} else {
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 < %zu",
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;
}
/*
* btrfs_read_dev_super - read a valid superblock from a block device
* @fd: file descriptor of the device
* @sb: buffer where the superblock is going to be read in
* @sb_bytenr: offset of the particular superblock copy we want
* @sbflags: flags controlling how the superblock is read
*
* This function is used by various btrfs commands to obtain a valid superblock.
*
* It's mode of operation is controlled by the @sb_bytenr and @sbdflags
* parameters. If SBREAD_RECOVER flag is set and @sb_bytenr is
* BTRFS_SUPER_INFO_OFFSET then the function reads all 3 superblock copies and
* returns the newest one. If SBREAD_RECOVER is not set then only a single
* copy is read, which one is decided by @sb_bytenr. If @sb_bytenr !=
* BTRFS_SUPER_INFO_OFFSET then the @sbflags is effectively ignored and only a
* single copy is read.
*/
int btrfs_read_dev_super(int fd, struct btrfs_super_block *sb, u64 sb_bytenr,
unsigned sbflags)
{
u8 fsid[BTRFS_FSID_SIZE];
u8 metadata_uuid[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 = sbflags & SBREAD_RECOVER ? BTRFS_SUPER_MIRROR_MAX : 1;
u64 transid = 0;
bool metadata_uuid_set = false;
u64 bytenr;
if (sb_bytenr != BTRFS_SUPER_INFO_OFFSET) {
ret = pread64(fd, buf, BTRFS_SUPER_INFO_SIZE, sb_bytenr);
/* real error */
if (ret < 0)
return -errno;
/* Not large enough sb, return -ENOENT instead of normal -EIO */
if (ret < BTRFS_SUPER_INFO_SIZE)
return -ENOENT;
if (btrfs_super_bytenr(buf) != sb_bytenr)
return -EIO;
ret = btrfs_check_super(buf, sbflags);
if (ret < 0)
return ret;
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 (btrfs_check_super(buf, sbflags))
continue;
if (!fsid_is_initialized) {
if (btrfs_super_incompat_flags(buf) &
BTRFS_FEATURE_INCOMPAT_METADATA_UUID) {
metadata_uuid_set = true;
memcpy(metadata_uuid, buf->metadata_uuid,
sizeof(metadata_uuid));
}
memcpy(fsid, buf->fsid, sizeof(fsid));
fsid_is_initialized = 1;
} else if (memcmp(fsid, buf->fsid, sizeof(fsid)) ||
(metadata_uuid_set && memcmp(metadata_uuid,
buf->metadata_uuid,
sizeof(metadata_uuid)))) {
/*
* 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_fs_info *fs_info,
struct btrfs_super_block *sb,
struct btrfs_device *device)
{
u64 bytenr;
u8 result[BTRFS_CSUM_SIZE];
int i, ret;
u16 csum_type = btrfs_super_csum_type(sb);
/*
* We need to write super block after all metadata written.
* This is the equivalent of kernel pre-flush for FUA.
*/
ret = fsync(device->fd);
if (ret < 0) {
error(
"failed to write super block for devid %llu: flush error: %m",
device->devid);
return -errno;
}
if (fs_info->super_bytenr != BTRFS_SUPER_INFO_OFFSET) {
btrfs_set_super_bytenr(sb, fs_info->super_bytenr);
btrfs_csum_data(csum_type, (u8 *)sb + BTRFS_CSUM_SIZE, result,
BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
memcpy(&sb->csum[0], result, BTRFS_CSUM_SIZE);
/*
* super_copy is BTRFS_SUPER_INFO_SIZE bytes and is
* zero filled, we can use it directly
*/
ret = pwrite64(device->fd, fs_info->super_copy,
BTRFS_SUPER_INFO_SIZE,
fs_info->super_bytenr);
if (ret != BTRFS_SUPER_INFO_SIZE) {
errno = EIO;
error(
"failed to write super block for devid %llu: write error: %m",
device->devid);
return -EIO;
}
ret = fsync(device->fd);
if (ret < 0) {
error(
"failed to write super block for devid %llu: flush error: %m",
device->devid);
return -errno;
}
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);
btrfs_csum_data(csum_type, (u8 *)sb + BTRFS_CSUM_SIZE, result,
BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
memcpy(&sb->csum[0], result, BTRFS_CSUM_SIZE);
/*
* super_copy is BTRFS_SUPER_INFO_SIZE bytes and is
* zero filled, we can use it directly
*/
ret = pwrite64(device->fd, fs_info->super_copy,
BTRFS_SUPER_INFO_SIZE, bytenr);
if (ret != BTRFS_SUPER_INFO_SIZE) {
errno = EIO;
error(
"failed to write super block for devid %llu: write error: %m",
device->devid);
return -errno;
}
/*
* Flush after the primary sb write, this is the equivalent of
* kernel post-flush for FUA write.
*/
if (i == 0) {
ret = fsync(device->fd);
if (ret < 0) {
error(
"failed to write super block for devid %llu: flush error: %m",
device->devid);
return -errno;
}
}
}
return 0;
}
/*
* copy all the root pointers into the super backup array.
* this will bump the backup pointer by one when it is
* done
*/
static void backup_super_roots(struct btrfs_fs_info *info)
{
struct btrfs_root_backup *root_backup;
int next_backup;
int last_backup;
last_backup = find_best_backup_root(info->super_copy);
next_backup = (last_backup + 1) % BTRFS_NUM_BACKUP_ROOTS;
/* just overwrite the last backup if we're at the same generation */
root_backup = info->super_copy->super_roots + last_backup;
if (btrfs_backup_tree_root_gen(root_backup) ==
btrfs_header_generation(info->tree_root->node))
next_backup = last_backup;
root_backup = info->super_copy->super_roots + next_backup;
/*
* make sure all of our padding and empty slots get zero filled
* regardless of which ones we use today
*/
memset(root_backup, 0, sizeof(*root_backup));
btrfs_set_backup_tree_root(root_backup, info->tree_root->node->start);
btrfs_set_backup_tree_root_gen(root_backup,
btrfs_header_generation(info->tree_root->node));
btrfs_set_backup_tree_root_level(root_backup,
btrfs_header_level(info->tree_root->node));
btrfs_set_backup_chunk_root(root_backup, info->chunk_root->node->start);
btrfs_set_backup_chunk_root_gen(root_backup,
btrfs_header_generation(info->chunk_root->node));
btrfs_set_backup_chunk_root_level(root_backup,
btrfs_header_level(info->chunk_root->node));
btrfs_set_backup_extent_root(root_backup, info->extent_root->node->start);
btrfs_set_backup_extent_root_gen(root_backup,
btrfs_header_generation(info->extent_root->node));
btrfs_set_backup_extent_root_level(root_backup,
btrfs_header_level(info->extent_root->node));
/*
* we might commit during log recovery, which happens before we set
* the fs_root. Make sure it is valid before we fill it in.
*/
if (info->fs_root && info->fs_root->node) {
btrfs_set_backup_fs_root(root_backup,
info->fs_root->node->start);
btrfs_set_backup_fs_root_gen(root_backup,
btrfs_header_generation(info->fs_root->node));
btrfs_set_backup_fs_root_level(root_backup,
btrfs_header_level(info->fs_root->node));
}
btrfs_set_backup_dev_root(root_backup, info->dev_root->node->start);
btrfs_set_backup_dev_root_gen(root_backup,
btrfs_header_generation(info->dev_root->node));
btrfs_set_backup_dev_root_level(root_backup,
btrfs_header_level(info->dev_root->node));
btrfs_set_backup_csum_root(root_backup, info->csum_root->node->start);
btrfs_set_backup_csum_root_gen(root_backup,
btrfs_header_generation(info->csum_root->node));
btrfs_set_backup_csum_root_level(root_backup,
btrfs_header_level(info->csum_root->node));
btrfs_set_backup_total_bytes(root_backup,
btrfs_super_total_bytes(info->super_copy));
btrfs_set_backup_bytes_used(root_backup,
btrfs_super_bytes_used(info->super_copy));
btrfs_set_backup_num_devices(root_backup,
btrfs_super_num_devices(info->super_copy));
};
int write_all_supers(struct btrfs_fs_info *fs_info)
{
struct list_head *head = &fs_info->fs_devices->devices;
struct btrfs_device *dev;
struct btrfs_super_block *sb;
struct btrfs_dev_item *dev_item;
int ret;
u64 flags;
backup_super_roots(fs_info);
sb = fs_info->super_copy;
dev_item = &sb->dev_item;
list_for_each_entry(dev, head, 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, fs_info->fs_devices->metadata_uuid,
BTRFS_FSID_SIZE);
flags = btrfs_super_flags(sb);
btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN);
ret = write_dev_supers(fs_info, sb, dev);
if (ret < 0)
return ret;
}
return 0;
}
int write_ctree_super(struct btrfs_trans_handle *trans)
{
int ret;
struct btrfs_fs_info *fs_info = trans->fs_info;
struct btrfs_root *tree_root = fs_info->tree_root;
struct btrfs_root *chunk_root = fs_info->chunk_root;
if (fs_info->readonly)
return 0;
btrfs_set_super_generation(fs_info->super_copy,
trans->transid);
btrfs_set_super_root(fs_info->super_copy,
tree_root->node->start);
btrfs_set_super_root_level(fs_info->super_copy,
btrfs_header_level(tree_root->node));
btrfs_set_super_chunk_root(fs_info->super_copy,
chunk_root->node->start);
btrfs_set_super_chunk_root_level(fs_info->super_copy,
btrfs_header_level(chunk_root->node));
btrfs_set_super_chunk_root_generation(fs_info->super_copy,
btrfs_header_generation(chunk_root->node));
ret = write_all_supers(fs_info);
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;
int err = 0;
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);
if (IS_ERR(trans)) {
err = PTR_ERR(trans);
goto skip_commit;
}
btrfs_commit_transaction(trans, root);
trans = btrfs_start_transaction(root, 1);
BUG_ON(IS_ERR(trans));
ret = commit_tree_roots(trans, fs_info);
BUG_ON(ret);
ret = __commit_transaction(trans, root);
BUG_ON(ret);
ret = write_ctree_super(trans);
kfree(trans);
if (ret) {
err = ret;
goto skip_commit;
}
}
if (fs_info->finalize_on_close) {
btrfs_set_super_magic(fs_info->super_copy, BTRFS_MAGIC);
root->fs_info->finalize_on_close = 0;
ret = write_all_supers(fs_info);
if (ret)
fprintf(stderr,
"failed to write new super block err %d\n", ret);
}
skip_commit:
btrfs_free_block_groups(fs_info);
free_fs_roots_tree(&fs_info->fs_root_tree);
btrfs_release_all_roots(fs_info);
ret = btrfs_close_devices(fs_info->fs_devices);
btrfs_cleanup_all_caches(fs_info);
btrfs_free_fs_info(fs_info);
if (!err)
err = ret;
return err;
}
int clean_tree_block(struct extent_buffer *eb)
{
return clear_extent_buffer_dirty(eb);
}
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);
}
struct btrfs_root *btrfs_create_tree(struct btrfs_trans_handle *trans,
struct btrfs_fs_info *fs_info,
u64 objectid)
{
struct extent_buffer *leaf;
struct btrfs_root *tree_root = fs_info->tree_root;
struct btrfs_root *root;
struct btrfs_key key;
int ret = 0;
root = kzalloc(sizeof(*root), GFP_KERNEL);
if (!root)
return ERR_PTR(-ENOMEM);
btrfs_setup_root(root, fs_info, objectid);
root->root_key.objectid = objectid;
root->root_key.type = BTRFS_ROOT_ITEM_KEY;
root->root_key.offset = 0;
leaf = btrfs_alloc_free_block(trans, root, fs_info->nodesize, objectid,
NULL, 0, 0, 0);
if (IS_ERR(leaf)) {
ret = PTR_ERR(leaf);
leaf = NULL;
goto fail;
}
memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header));
btrfs_set_header_bytenr(leaf, leaf->start);
btrfs_set_header_generation(leaf, trans->transid);
btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
btrfs_set_header_owner(leaf, objectid);
root->node = leaf;
write_extent_buffer(leaf, fs_info->fs_devices->metadata_uuid,
btrfs_header_fsid(), BTRFS_FSID_SIZE);
write_extent_buffer(leaf, fs_info->chunk_tree_uuid,
btrfs_header_chunk_tree_uuid(leaf),
BTRFS_UUID_SIZE);
btrfs_mark_buffer_dirty(leaf);
extent_buffer_get(root->node);
root->commit_root = root->node;
root->track_dirty = 1;
root->root_item.flags = 0;
root->root_item.byte_limit = 0;
btrfs_set_root_bytenr(&root->root_item, leaf->start);
btrfs_set_root_generation(&root->root_item, trans->transid);
btrfs_set_root_level(&root->root_item, 0);
btrfs_set_root_refs(&root->root_item, 1);
btrfs_set_root_used(&root->root_item, leaf->len);
btrfs_set_root_last_snapshot(&root->root_item, 0);
btrfs_set_root_dirid(&root->root_item, 0);
memset(root->root_item.uuid, 0, BTRFS_UUID_SIZE);
root->root_item.drop_level = 0;
key.objectid = objectid;
key.type = BTRFS_ROOT_ITEM_KEY;
key.offset = 0;
ret = btrfs_insert_root(trans, tree_root, &key, &root->root_item);
if (ret)
goto fail;
return root;
fail:
if (leaf)
free_extent_buffer(leaf);
kfree(root);
return ERR_PTR(ret);
}
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