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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 "kernel-lib/radix-tree.h"
#include "ctree.h"
#include "disk-io.h"
#include "volumes.h"
#include "transaction.h"
#include "kernel-lib/crc32c.h"
#include "common/utils.h"
#include "print-tree.h"
#include "common/rbtree-utils.h"
#include "common/device-scan.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 > %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(char *data, u8 *seed, size_t len)
{
return crc32c(*(u32*)seed, data, len);
}
void btrfs_csum_final(u32 crc, u8 *result)
{
put_unaligned_le32(~crc, result);
}
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;
u32 crc = ~(u32)0;
len = buf->len - BTRFS_CSUM_SIZE;
crc = btrfs_csum_data(buf->data + BTRFS_CSUM_SIZE, (u8 *)&crc, 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,
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 (%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);
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 (%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,
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) {
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);
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->tree_root);
/*
* 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 != -ENOENT)
return -EIO;
}
key.objectid = BTRFS_FS_TREE_OBJECTID;
key.type = BTRFS_ROOT_ITEM_KEY;