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btrfs-progs/image/image-create.c

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/*
* 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 "kerncompat.h"
#include <errno.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include <pthread.h>
#include <zlib.h>
#include "kernel-lib/list.h"
#include "kernel-lib/rbtree.h"
#include "kernel-lib/rbtree_types.h"
#include "kernel-shared/accessors.h"
#include "kernel-shared/extent-io-tree.h"
#include "kernel-shared/extent_io.h"
#include "kernel-shared/uapi/btrfs_tree.h"
#include "kernel-shared/ctree.h"
#include "kernel-shared/file-item.h"
#include "kernel-shared/disk-io.h"
#include "kernel-shared/volumes.h"
#include "kernel-shared/tree-checker.h"
#include "common/internal.h"
#include "common/messages.h"
#include "image/sanitize.h"
#include "image/metadump.h"
#include "image/common.h"
static void *dump_worker(void *data)
{
struct metadump_struct *md = (struct metadump_struct *)data;
struct async_work *async;
int ret;
while (1) {
pthread_mutex_lock(&md->mutex);
while (list_empty(&md->list)) {
if (md->done) {
pthread_mutex_unlock(&md->mutex);
goto out;
}
pthread_cond_wait(&md->cond, &md->mutex);
}
async = list_entry(md->list.next, struct async_work, list);
list_del_init(&async->list);
pthread_mutex_unlock(&md->mutex);
if (md->compress_level > 0) {
u8 *orig = async->buffer;
async->bufsize = compressBound(async->size);
async->buffer = malloc(async->bufsize);
if (!async->buffer) {
error_msg(ERROR_MSG_MEMORY, "async buffer");
pthread_mutex_lock(&md->mutex);
if (!md->error)
md->error = -ENOMEM;
pthread_mutex_unlock(&md->mutex);
pthread_exit(NULL);
}
ret = compress2(async->buffer,
(unsigned long *)&async->bufsize,
orig, async->size, md->compress_level);
if (ret != Z_OK)
async->error = 1;
free(orig);
}
pthread_mutex_lock(&md->mutex);
md->num_ready++;
pthread_mutex_unlock(&md->mutex);
}
out:
pthread_exit(NULL);
}
static void meta_cluster_init(struct metadump_struct *md, u64 start)
{
struct meta_cluster_header *header;
md->num_items = 0;
md->num_ready = 0;
header = &md->cluster.header;
header->magic = cpu_to_le64(current_version->magic_cpu);
header->bytenr = cpu_to_le64(start);
header->nritems = cpu_to_le32(0);
header->compress = md->compress_level > 0 ?
COMPRESS_ZLIB : COMPRESS_NONE;
}
static void metadump_destroy(struct metadump_struct *md, int num_threads)
{
int i;
struct rb_node *n;
pthread_mutex_lock(&md->mutex);
md->done = 1;
pthread_cond_broadcast(&md->cond);
pthread_mutex_unlock(&md->mutex);
for (i = 0; i < num_threads; i++)
pthread_join(md->threads[i], NULL);
pthread_cond_destroy(&md->cond);
pthread_mutex_destroy(&md->mutex);
while ((n = rb_first(&md->name_tree))) {
struct name *name;
name = rb_entry(n, struct name, n);
rb_erase(n, &md->name_tree);
free(name->val);
free(name->sub);
free(name);
}
extent_io_tree_release(&md->seen);
}
static int metadump_init(struct metadump_struct *md, struct btrfs_root *root,
FILE *out, int num_threads, int compress_level,
bool dump_data, enum sanitize_mode sanitize_names)
{
int i, ret = 0;
/* We need larger item/cluster limit for data extents */
if (dump_data)
current_version = &dump_versions[1];
memset(md, 0, sizeof(*md));
INIT_LIST_HEAD(&md->list);
INIT_LIST_HEAD(&md->ordered);
extent_io_tree_init(NULL, &md->seen, 0);
md->root = root;
md->out = out;
md->pending_start = (u64)-1;
md->compress_level = compress_level;
md->sanitize_names = sanitize_names;
md->name_tree.rb_node = NULL;
md->num_threads = num_threads;
pthread_cond_init(&md->cond, NULL);
pthread_mutex_init(&md->mutex, NULL);
meta_cluster_init(md, 0);
if (!num_threads)
return 0;
for (i = 0; i < num_threads; i++) {
ret = pthread_create(md->threads + i, NULL, dump_worker, md);
if (ret)
break;
}
if (ret)
metadump_destroy(md, i + 1);
return ret;
}
static int read_data_extent(struct metadump_struct *md,
struct async_work *async)
{
struct btrfs_root *root = md->root;
struct btrfs_fs_info *fs_info = root->fs_info;
u64 bytes_left = async->size;
u64 logical = async->start;
u64 offset = 0;
u64 read_len;
int num_copies;
int cur_mirror;
int ret;
num_copies = btrfs_num_copies(root->fs_info, logical, bytes_left);
/* Try our best to read data, just like read_tree_block() */
for (cur_mirror = 1; cur_mirror <= num_copies; cur_mirror++) {
while (bytes_left) {
read_len = bytes_left;
ret = read_data_from_disk(fs_info,
(char *)(async->buffer + offset),
logical, &read_len, cur_mirror);
if (ret < 0)
break;
offset += read_len;
logical += read_len;
bytes_left -= read_len;
}
}
if (bytes_left)
return -EIO;
return 0;
}
static int get_dev_fd(struct btrfs_root *root)
{
struct btrfs_device *dev;
dev = list_first_entry(&root->fs_info->fs_devices->devices,
struct btrfs_device, dev_list);
return dev->fd;
}
static int write_zero(FILE *out, size_t size)
{
static char zero[IMAGE_BLOCK_SIZE];
return fwrite(zero, size, 1, out);
}
static int write_buffers(struct metadump_struct *md, u64 *next)
{
struct meta_cluster_header *header = &md->cluster.header;
struct meta_cluster_item *item;
struct async_work *async;
u64 bytenr = 0;
u32 nritems = 0;
int ret;
int err = 0;
if (list_empty(&md->ordered))
goto out;
/* wait until all buffers are compressed */
while (!err && md->num_items > md->num_ready) {
struct timespec ts = {
.tv_sec = 0,
.tv_nsec = 10000000,
};
pthread_mutex_unlock(&md->mutex);
nanosleep(&ts, NULL);
pthread_mutex_lock(&md->mutex);
err = md->error;
}
if (err) {
errno = -err;
error("one of the threads failed: %m");
goto out;
}
/* setup and write index block */
list_for_each_entry(async, &md->ordered, ordered) {
item = &md->cluster.items[nritems];
item->bytenr = cpu_to_le64(async->start);
item->size = cpu_to_le32(async->bufsize);
nritems++;
}
header->nritems = cpu_to_le32(nritems);
ret = fwrite(&md->cluster, IMAGE_BLOCK_SIZE, 1, md->out);
if (ret != 1) {
error("unable to write out cluster: %m");
return -errno;
}
/* write buffers */
bytenr += le64_to_cpu(header->bytenr) + IMAGE_BLOCK_SIZE;
while (!list_empty(&md->ordered)) {
async = list_entry(md->ordered.next, struct async_work,
ordered);
list_del_init(&async->ordered);
bytenr += async->bufsize;
if (!err)
ret = fwrite(async->buffer, async->bufsize, 1,
md->out);
if (ret != 1) {
error("unable to write out cluster: %m");
err = -errno;
ret = 0;
}
free(async->buffer);
free(async);
}
/* zero unused space in the last block */
if (!err && bytenr & IMAGE_BLOCK_MASK) {
size_t size = IMAGE_BLOCK_SIZE - (bytenr & IMAGE_BLOCK_MASK);
bytenr += size;
ret = write_zero(md->out, size);
if (ret != 1) {
error("unable to zero out buffer: %m");
err = -errno;
}
}
out:
*next = bytenr;
return err;
}
static bool has_name(struct btrfs_key *key)
{
switch (key->type) {
case BTRFS_DIR_ITEM_KEY:
case BTRFS_DIR_INDEX_KEY:
case BTRFS_INODE_REF_KEY:
case BTRFS_INODE_EXTREF_KEY:
case BTRFS_XATTR_ITEM_KEY:
return true;
default:
break;
}
return false;
}
/*
* zero inline extents and csum items
*/
static void zero_items(struct metadump_struct *md, u8 *dst,
struct extent_buffer *src)
{
struct btrfs_file_extent_item *fi;
struct btrfs_key key;
u32 nritems = btrfs_header_nritems(src);
size_t size;
unsigned long ptr;
int i, extent_type;
for (i = 0; i < nritems; i++) {
btrfs_item_key_to_cpu(src, &key, i);
if (key.type == BTRFS_CSUM_ITEM_KEY) {
size = btrfs_item_size(src, i);
memset(dst + btrfs_item_nr_offset(src, 0) +
btrfs_item_offset(src, i), 0, size);
continue;
}
if (md->sanitize_names && has_name(&key)) {
sanitize_name(md->sanitize_names, &md->name_tree, dst,
src, &key, i);
continue;
}
if (key.type != BTRFS_EXTENT_DATA_KEY)
continue;
fi = btrfs_item_ptr(src, i, struct btrfs_file_extent_item);
extent_type = btrfs_file_extent_type(src, fi);
if (extent_type != BTRFS_FILE_EXTENT_INLINE)
continue;
ptr = btrfs_file_extent_inline_start(fi);
size = btrfs_file_extent_inline_item_len(src, i);
memset(dst + ptr, 0, size);
}
}
/*
* copy buffer and zero useless data in the buffer
*/
static void copy_buffer(struct metadump_struct *md, u8 *dst, struct extent_buffer *src)
{
int level;
size_t size;
u32 nritems;
memcpy(dst, src->data, src->len);
if (src->start == BTRFS_SUPER_INFO_OFFSET)
return;
level = btrfs_header_level(src);
nritems = btrfs_header_nritems(src);
if (nritems == 0) {
size = sizeof(struct btrfs_header);
memset(dst + size, 0, src->len - size);
} else if (level == 0) {
size = btrfs_item_nr_offset(src, 0) +
btrfs_item_offset(src, nritems - 1) -
btrfs_item_nr_offset(src, nritems);
memset(dst + btrfs_item_nr_offset(src, nritems), 0, size);
zero_items(md, dst, src);
} else {
size = offsetof(struct btrfs_node, ptrs) +
sizeof(struct btrfs_key_ptr) * nritems;
memset(dst + size, 0, src->len - size);
}
csum_block(dst, src->len);
}
static int flush_pending(struct metadump_struct *md, int done)
{
struct async_work *async = NULL;
struct extent_buffer *eb;
u64 start = 0;
u64 size;
size_t offset;
int ret = 0;
if (md->pending_size) {
async = calloc(1, sizeof(*async));
if (!async)
return -ENOMEM;
async->start = md->pending_start;
async->size = md->pending_size;
async->bufsize = async->size;
async->buffer = malloc(async->bufsize);
if (!async->buffer) {
free(async);
return -ENOMEM;
}
offset = 0;
start = async->start;
size = async->size;
if (md->data) {
ret = read_data_extent(md, async);
if (ret) {
free(async->buffer);
free(async);
return ret;
}
}
/*
* Balance can make the mapping not cover the super block, so
* just copy directly from one of the devices.
*/
if (start == BTRFS_SUPER_INFO_OFFSET) {
int fd = get_dev_fd(md->root);
ret = pread(fd, async->buffer, size, start);
if (ret < size) {
free(async->buffer);
free(async);
error("unable to read superblock at %llu: %m", start);
return -errno;
}
size = 0;
ret = 0;
}
while (!md->data && size > 0) {
struct btrfs_tree_parent_check check = { 0 };
u64 this_read = min((u64)md->root->fs_info->nodesize,
size);
eb = read_tree_block(md->root->fs_info, start, &check);
if (!extent_buffer_uptodate(eb)) {
free(async->buffer);
free(async);
error("unable to read metadata block %llu", start);
return -EIO;
}
copy_buffer(md, async->buffer + offset, eb);
free_extent_buffer(eb);
start += this_read;
offset += this_read;
size -= this_read;
}
md->pending_start = (u64)-1;
md->pending_size = 0;
} else if (!done) {
return 0;
}
pthread_mutex_lock(&md->mutex);
if (async) {
list_add_tail(&async->ordered, &md->ordered);
md->num_items++;
if (md->compress_level > 0) {
list_add_tail(&async->list, &md->list);
pthread_cond_signal(&md->cond);
} else {
md->num_ready++;
}
}
if (md->num_items >= ITEMS_PER_CLUSTER || done) {
ret = write_buffers(md, &start);
if (ret) {
errno = -ret;
error("unable to write buffers: %m");
} else {
meta_cluster_init(md, start);
}
}
pthread_mutex_unlock(&md->mutex);
return ret;
}
static int add_extent(u64 start, u64 size, struct metadump_struct *md,
int data)
{
int ret;
if (md->data != data ||
md->pending_size + size > current_version->max_pending_size ||
md->pending_start + md->pending_size != start) {
ret = flush_pending(md, 0);
if (ret)
return ret;
md->pending_start = start;
}
readahead_tree_block(md->root->fs_info, start, 0);
md->pending_size += size;
md->data = data;
return 0;
}
static int copy_tree_blocks(struct btrfs_root *root, struct extent_buffer *eb,
struct metadump_struct *metadump, int root_tree)
{
struct extent_buffer *tmp;
struct btrfs_root_item *ri;
struct btrfs_key key;
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_tree_parent_check check = { 0 };
u64 bytenr;
int level;
int nritems = 0;
int i = 0;
int ret;
bytenr = btrfs_header_bytenr(eb);
if (test_range_bit(&metadump->seen, bytenr,
bytenr + fs_info->nodesize - 1, EXTENT_DIRTY, 1,
NULL))
return 0;
set_extent_dirty(&metadump->seen, bytenr,
bytenr + fs_info->nodesize - 1, GFP_NOFS);
ret = add_extent(btrfs_header_bytenr(eb), fs_info->nodesize,
metadump, 0);
if (ret) {
error("unable to add metadata block %llu: %d",
btrfs_header_bytenr(eb), ret);
return ret;
}
if (btrfs_header_level(eb) == 0 && !root_tree)
return 0;
level = btrfs_header_level(eb);
nritems = btrfs_header_nritems(eb);
for (i = 0; i < nritems; i++) {
if (level == 0) {
btrfs_item_key_to_cpu(eb, &key, i);
if (key.type != BTRFS_ROOT_ITEM_KEY)
continue;
ri = btrfs_item_ptr(eb, i, struct btrfs_root_item);
bytenr = btrfs_disk_root_bytenr(eb, ri);
tmp = read_tree_block(fs_info, bytenr, &check);
if (!extent_buffer_uptodate(tmp)) {
error("unable to read log root block");
return -EIO;
}
ret = copy_tree_blocks(root, tmp, metadump, 0);
free_extent_buffer(tmp);
if (ret)
return ret;
} else {
bytenr = btrfs_node_blockptr(eb, i);
tmp = read_tree_block(fs_info, bytenr, &check);
if (!extent_buffer_uptodate(tmp)) {
error("unable to read log root block");
return -EIO;
}
ret = copy_tree_blocks(root, tmp, metadump, root_tree);
free_extent_buffer(tmp);
if (ret)
return ret;
}
}
return 0;
}
static int copy_log_trees(struct btrfs_root *root,
struct metadump_struct *metadump)
{
u64 blocknr = btrfs_super_log_root(root->fs_info->super_copy);
if (blocknr == 0)
return 0;
if (!root->fs_info->log_root_tree ||
!root->fs_info->log_root_tree->node) {
error("unable to copy tree log, it has not been setup");
return -EIO;
}
return copy_tree_blocks(root, root->fs_info->log_root_tree->node,
metadump, 1);
}
static int copy_space_cache(struct btrfs_root *root,
struct metadump_struct *metadump,
struct btrfs_path *path)
{
struct extent_buffer *leaf;
struct btrfs_file_extent_item *fi;
struct btrfs_key key;
u64 bytenr, num_bytes;
int ret;
root = root->fs_info->tree_root;
key.objectid = 0;
key.type = BTRFS_EXTENT_DATA_KEY;
key.offset = 0;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0) {
error("free space inode not found: %d", ret);
return ret;
}
leaf = path->nodes[0];
while (1) {
if (path->slots[0] >= btrfs_header_nritems(leaf)) {
ret = btrfs_next_leaf(root, path);
if (ret < 0) {
error("cannot go to next leaf %d", ret);
return ret;
}
if (ret > 0)
break;
leaf = path->nodes[0];
}
btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
if (key.type != BTRFS_EXTENT_DATA_KEY) {
path->slots[0]++;
continue;
}
fi = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_file_extent_item);
if (btrfs_file_extent_type(leaf, fi) !=
BTRFS_FILE_EXTENT_REG) {
path->slots[0]++;
continue;
}
bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
ret = add_extent(bytenr, num_bytes, metadump, 1);
if (ret) {
error("unable to add space cache blocks %d", ret);
btrfs_release_path(path);
return ret;
}
path->slots[0]++;
}
return 0;
}
static int copy_from_extent_tree(struct metadump_struct *metadump,
struct btrfs_path *path, bool dump_data)
{
struct btrfs_root *extent_root;
struct extent_buffer *leaf;
struct btrfs_extent_item *ei;
struct btrfs_key key;
u64 bytenr;
u64 num_bytes;
int ret;
extent_root = btrfs_extent_root(metadump->root->fs_info, 0);
bytenr = BTRFS_SUPER_INFO_OFFSET + BTRFS_SUPER_INFO_SIZE;
key.objectid = bytenr;
key.type = BTRFS_EXTENT_ITEM_KEY;
key.offset = 0;
ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
if (ret < 0) {
error("extent root not found: %d", ret);
return ret;
}
ret = 0;
leaf = path->nodes[0];
while (1) {
if (path->slots[0] >= btrfs_header_nritems(leaf)) {
ret = btrfs_next_leaf(extent_root, path);
if (ret < 0) {
error("cannot go to next leaf %d", ret);
break;
}
if (ret > 0) {
ret = 0;
break;
}
leaf = path->nodes[0];
}
btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
if (key.objectid < bytenr ||
(key.type != BTRFS_EXTENT_ITEM_KEY &&
key.type != BTRFS_METADATA_ITEM_KEY)) {
path->slots[0]++;
continue;
}
bytenr = key.objectid;
if (key.type == BTRFS_METADATA_ITEM_KEY) {
num_bytes = extent_root->fs_info->nodesize;
} else {
num_bytes = key.offset;
}
if (num_bytes == 0) {
error("extent length 0 at bytenr %llu key type %d",
bytenr, key.type);
ret = -EIO;
break;
}
if (btrfs_item_size(leaf, path->slots[0]) >= sizeof(*ei)) {
ei = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_extent_item);
if (btrfs_extent_flags(leaf, ei) &
BTRFS_EXTENT_FLAG_TREE_BLOCK ||
(dump_data && (btrfs_extent_flags(leaf, ei) &
BTRFS_EXTENT_FLAG_DATA))) {
bool is_data;
is_data = btrfs_extent_flags(leaf, ei) &
BTRFS_EXTENT_FLAG_DATA;
ret = add_extent(bytenr, num_bytes, metadump,
is_data);
if (ret) {
error("unable to add block %llu: %d",
bytenr, ret);
break;
}
}
} else {
error(
"either extent tree is corrupted or deprecated extent ref format");
ret = -EIO;
break;
}
bytenr += num_bytes;
}
btrfs_release_path(path);
return ret;
}
int create_metadump(const char *input, FILE *out, int num_threads,
int compress_level, enum sanitize_mode sanitize,
int walk_trees, bool dump_data)
{
struct btrfs_root *root;
struct btrfs_path path = { 0 };
struct metadump_struct metadump;
int ret;
int err = 0;
root = open_ctree(input, 0, OPEN_CTREE_ALLOW_TRANSID_MISMATCH |
OPEN_CTREE_SKIP_LEAF_ITEM_CHECKS);
if (!root) {
error("open ctree failed");
return -EIO;
}
ret = metadump_init(&metadump, root, out, num_threads,
compress_level, dump_data, sanitize);
if (ret) {
error("failed to initialize metadump: %d", ret);
close_ctree(root);
return ret;
}
ret = add_extent(BTRFS_SUPER_INFO_OFFSET, BTRFS_SUPER_INFO_SIZE,
&metadump, 0);
if (ret) {
error("unable to add metadata: %d", ret);
err = ret;
goto out;
}
if (walk_trees) {
ret = copy_tree_blocks(root, root->fs_info->chunk_root->node,
&metadump, 1);
if (ret) {
err = ret;
goto out;
}
ret = copy_tree_blocks(root, root->fs_info->tree_root->node,
&metadump, 1);
if (ret) {
err = ret;
goto out;
}
} else {
ret = copy_from_extent_tree(&metadump, &path, dump_data);
if (ret) {
err = ret;
goto out;
}
}
ret = copy_log_trees(root, &metadump);
if (ret) {
err = ret;
goto out;
}
ret = copy_space_cache(root, &metadump, &path);
out:
ret = flush_pending(&metadump, 1);
if (ret) {
if (!err)
err = ret;
error("failed to flush pending data: %d", ret);
}
metadump_destroy(&metadump, num_threads);
btrfs_release_path(&path);
ret = close_ctree(root);
return err ? err : ret;
}
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