blob: 3f0d9f1c113ba33409ac52ef86fabddb789eecd0 [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0+
#include <common.h>
#include <fs_internal.h>
#include <log.h>
#include <uuid.h>
#include <memalign.h>
#include "kernel-shared/btrfs_tree.h"
#include "common/rbtree-utils.h"
#include "disk-io.h"
#include "ctree.h"
#include "btrfs.h"
#include "volumes.h"
#include "extent-io.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 (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_blake2(data, len, out);
default:
printf("Unknown csum type %d\n", csum_type);
return -EINVAL;
}
}
/*
* 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 btrfs_check_super(struct btrfs_super_block *sb)
{
u8 result[BTRFS_CSUM_SIZE];
u16 csum_type;
int csum_size;
u8 *metadata_uuid;
if (btrfs_super_magic(sb) != BTRFS_MAGIC)
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);
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)) {
error("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 primary superblock from a block device
* @desc,@part: file descriptor of the device
* @sb: buffer where the superblock is going to be read in
*
* Unlike the btrfs-progs/kernel version, here we ony care about the first
* super block, thus it's much simpler.
*/
int btrfs_read_dev_super(struct blk_desc *desc, struct disk_partition *part,
struct btrfs_super_block *sb)
{
ALLOC_CACHE_ALIGN_BUFFER(char, tmp, BTRFS_SUPER_INFO_SIZE);
struct btrfs_super_block *buf = (struct btrfs_super_block *)tmp;
int ret;
ret = __btrfs_devread(desc, part, tmp, BTRFS_SUPER_INFO_SIZE,
BTRFS_SUPER_INFO_OFFSET);
if (ret < BTRFS_SUPER_INFO_SIZE)
return -EIO;
if (btrfs_super_bytenr(buf) != BTRFS_SUPER_INFO_OFFSET)
return -EIO;
if (btrfs_check_super(buf))
return -EIO;
memcpy(sb, buf, BTRFS_SUPER_INFO_SIZE);
return 0;
}
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);
}
static 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);
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);
}
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;
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->desc || !device->part) {
kfree(multi);
return -EIO;
}
if (read_len > bytes_left)
read_len = bytes_left;
ret = read_extent_from_disk(device->desc, device->part,
multi->stripes[0].physical, eb,
offset, read_len);
kfree(multi);
multi = NULL;
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(&fs_info->extent_cache, eb,
parent_transid, ignore) == 0) {
/*
* 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))
print_tree_block_error(fs_info, eb,
check_tree_block(fs_info, eb));
else
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(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->desc || !device->part) {
ret = -EIO;
goto err;
}
ret = __btrfs_devread(device->desc, device->part, data, *len,
multi->stripes[0].physical);
if (ret != *len)
ret = -EIO;
else
ret = 0;
err:
kfree(multi);
return ret;
}
void btrfs_setup_root(struct btrfs_root *root, struct btrfs_fs_info *fs_info,
u64 objectid)
{
root->node = NULL;
root->track_dirty = 0;
root->fs_info = fs_info;
root->objectid = objectid;
root->last_trans = 0;
root->last_inode_alloc = 0;
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;
}
int btrfs_free_fs_root(struct btrfs_root *root)
{
if (root->node)
free_extent_buffer(root->node);
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));
/* If this root is already an orphan, no need to read */
if (btrfs_root_refs(&root->root_item) == 0) {
ret = -ENOENT;
goto out;
}
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_CHUNK_TREE_OBJECTID)
return fs_info->chunk_root;
if (location->objectid == BTRFS_CSUM_TREE_OBJECTID)
return fs_info->csum_root;
BUG_ON(location->objectid == BTRFS_TREE_RELOC_OBJECTID);
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->chunk_root);
free(fs_info->csum_root);
free(fs_info->super_copy);
free(fs_info);
}
struct btrfs_fs_info *btrfs_new_fs_info(void)
{
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->chunk_root = calloc(1, sizeof(struct btrfs_root));
fs_info->csum_root = calloc(1, sizeof(struct btrfs_root));
fs_info->super_copy = calloc(1, BTRFS_SUPER_INFO_SIZE);
if (!fs_info->tree_root || !fs_info->chunk_root ||
!fs_info->csum_root || !fs_info->super_copy)
goto free_all;
extent_io_tree_init(&fs_info->extent_cache);
fs_info->fs_root_tree = RB_ROOT;
cache_tree_init(&fs_info->mapping_tree.cache_tree);
return fs_info;
free_all:
btrfs_free_fs_info(fs_info);
return NULL;
}
static int setup_root_or_create_block(struct btrfs_fs_info *fs_info,
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) {
error("could not setup %s tree", str);
return -EIO;
}
return 0;
}
static int get_default_subvolume(struct btrfs_fs_info *fs_info,
struct btrfs_key *key_ret)
{
struct btrfs_root *root = fs_info->tree_root;
struct btrfs_dir_item *dir_item;
struct btrfs_path path;
int ret = 0;
btrfs_init_path(&path);
dir_item = btrfs_lookup_dir_item(NULL, root, &path,
BTRFS_ROOT_TREE_DIR_OBJECTID,
"default", 7, 0);
if (IS_ERR(dir_item)) {
ret = PTR_ERR(dir_item);
goto out;
}
btrfs_dir_item_key_to_cpu(path.nodes[0], dir_item, key_ret);
out:
btrfs_release_path(&path);
return ret;
}
int btrfs_setup_all_roots(struct btrfs_fs_info *fs_info)
{
struct btrfs_super_block *sb = fs_info->super_copy;
struct btrfs_root *root;
struct btrfs_key key;
u64 root_tree_bytenr;
u64 generation;
int ret;
root = fs_info->tree_root;
btrfs_setup_root(root, fs_info, BTRFS_ROOT_TREE_OBJECTID);
generation = btrfs_super_generation(sb);
root_tree_bytenr = btrfs_super_root(sb);
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, fs_info->csum_root,
BTRFS_CSUM_TREE_OBJECTID, "csum");
if (ret)
return ret;
fs_info->csum_root->track_dirty = 1;
fs_info->last_trans_committed = generation;
ret = get_default_subvolume(fs_info, &key);
if (ret) {
/*
* The default dir item isn't there. Linux kernel behaviour is
* to silently use the top-level subvolume in this case.
*/
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->csum_root)
free_extent_buffer(fs_info->csum_root->node);
if (fs_info->tree_root)
free_extent_buffer(fs_info->tree_root->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)
{
free_mapping_cache_tree(&fs_info->mapping_tree.cache_tree);
extent_io_tree_cleanup(&fs_info->extent_cache);
}
static int btrfs_scan_fs_devices(struct blk_desc *desc,
struct disk_partition *part,
struct btrfs_fs_devices **fs_devices)
{
u64 total_devs;
int ret;
if (round_up(BTRFS_SUPER_INFO_SIZE + BTRFS_SUPER_INFO_OFFSET,
desc->blksz) > (part->size << desc->log2blksz)) {
log_debug("superblock end %u is larger than device size " LBAFU,
BTRFS_SUPER_INFO_SIZE + BTRFS_SUPER_INFO_OFFSET,
part->size << desc->log2blksz);
return -EINVAL;
}
ret = btrfs_scan_one_device(desc, part, fs_devices, &total_devs);
if (ret) {
/*
* Avoid showing this when probing for a possible Btrfs
*
* fprintf(stderr, "No valid Btrfs found\n");
*/
return ret;
}
return 0;
}
int btrfs_check_fs_compatibility(struct btrfs_super_block *sb)
{
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 -ENOTSUPP;
}
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);
}
return 0;
}
static int btrfs_setup_chunk_tree_and_device_map(struct btrfs_fs_info *fs_info)
{
struct btrfs_super_block *sb = fs_info->super_copy;
u64 chunk_root_bytenr;
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);
chunk_root_bytenr = btrfs_super_chunk_root(sb);
fs_info->chunk_root->node = read_tree_block(fs_info,
chunk_root_bytenr,
generation);
if (!extent_buffer_uptodate(fs_info->chunk_root->node)) {
error("cannot read chunk root");
return -EIO;
}
ret = btrfs_read_chunk_tree(fs_info);
if (ret) {
fprintf(stderr, "Couldn't read chunk tree\n");
return ret;
}
return 0;
}
struct btrfs_fs_info *open_ctree_fs_info(struct blk_desc *desc,
struct disk_partition *part)
{
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;
fs_info = btrfs_new_fs_info();
if (!fs_info) {
fprintf(stderr, "Failed to allocate memory for fs_info\n");
return NULL;
}
ret = btrfs_scan_fs_devices(desc, part, &fs_devices);
if (ret)
goto out;
fs_info->fs_devices = fs_devices;
ret = btrfs_open_devices(fs_devices);
if (ret)
goto out;
disk_super = fs_info->super_copy;
ret = btrfs_read_dev_super(desc, part, disk_super);
if (ret) {
debug("No valid btrfs found\n");
goto out_devices;
}
if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_CHANGING_FSID) {
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);
if (ret)
goto out_devices;
ret = btrfs_setup_chunk_tree_and_device_map(fs_info);
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);
if (ret)
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;
}
int close_ctree_fs_info(struct btrfs_fs_info *fs_info)
{
int ret;
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);
return ret;
}
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->fs_info->extent_cache, buf,
parent_transid, 1);
return !ret;
}
int btrfs_set_buffer_uptodate(struct extent_buffer *eb)
{
return set_extent_buffer_uptodate(eb);
}