btrfs-progs/btrfs-image.c
Danny Kukawka c88c2f52fe btrfs-progs: Handle errors returned from open_ctree
Signed-off-by: Danny Kukawka <danny.kukawka@bisect.de>
Signed-off-by: David Sterba <dsterba@suse.cz>
2013-01-21 18:27:54 +01:00

892 lines
20 KiB
C

/*
* Copyright (C) 2008 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.
*/
#define _XOPEN_SOURCE 500
#define _GNU_SOURCE 1
#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <dirent.h>
#include <zlib.h>
#include "kerncompat.h"
#include "crc32c.h"
#include "ctree.h"
#include "disk-io.h"
#include "transaction.h"
#include "utils.h"
#include "version.h"
#define HEADER_MAGIC 0xbd5c25e27295668bULL
#define MAX_PENDING_SIZE (256 * 1024)
#define BLOCK_SIZE 1024
#define BLOCK_MASK (BLOCK_SIZE - 1)
#define COMPRESS_NONE 0
#define COMPRESS_ZLIB 1
struct meta_cluster_item {
__le64 bytenr;
__le32 size;
} __attribute__ ((__packed__));
struct meta_cluster_header {
__le64 magic;
__le64 bytenr;
__le32 nritems;
u8 compress;
} __attribute__ ((__packed__));
/* cluster header + index items + buffers */
struct meta_cluster {
struct meta_cluster_header header;
struct meta_cluster_item items[];
} __attribute__ ((__packed__));
#define ITEMS_PER_CLUSTER ((BLOCK_SIZE - sizeof(struct meta_cluster)) / \
sizeof(struct meta_cluster_item))
struct async_work {
struct list_head list;
struct list_head ordered;
u64 start;
u64 size;
u8 *buffer;
size_t bufsize;
};
struct metadump_struct {
struct btrfs_root *root;
FILE *out;
struct meta_cluster *cluster;
pthread_t *threads;
size_t num_threads;
pthread_mutex_t mutex;
pthread_cond_t cond;
struct list_head list;
struct list_head ordered;
size_t num_items;
size_t num_ready;
u64 pending_start;
u64 pending_size;
int compress_level;
int done;
};
struct mdrestore_struct {
FILE *in;
FILE *out;
pthread_t *threads;
size_t num_threads;
pthread_mutex_t mutex;
pthread_cond_t cond;
struct list_head list;
size_t num_items;
int compress_method;
int done;
};
static void csum_block(u8 *buf, size_t len)
{
char result[BTRFS_CRC32_SIZE];
u32 crc = ~(u32)0;
crc = crc32c(crc, buf + BTRFS_CSUM_SIZE, len - BTRFS_CSUM_SIZE);
btrfs_csum_final(crc, result);
memcpy(buf, result, BTRFS_CRC32_SIZE);
}
/*
* zero inline extents and csum items
*/
static void zero_items(u8 *dst, struct extent_buffer *src)
{
struct btrfs_file_extent_item *fi;
struct btrfs_item *item;
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++) {
item = btrfs_item_nr(src, i);
btrfs_item_key_to_cpu(src, &key, i);
if (key.type == BTRFS_CSUM_ITEM_KEY) {
size = btrfs_item_size_nr(src, i);
memset(dst + btrfs_leaf_data(src) +
btrfs_item_offset_nr(src, i), 0, size);
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, item);
memset(dst + ptr, 0, size);
}
}
/*
* copy buffer and zero useless data in the buffer
*/
static void copy_buffer(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_leaf_data(src) +
btrfs_item_offset_nr(src, nritems - 1) -
btrfs_item_nr_offset(nritems);
memset(dst + btrfs_item_nr_offset(nritems), 0, size);
zero_items(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 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);
ret = compress2(async->buffer,
(unsigned long *)&async->bufsize,
orig, async->size, md->compress_level);
BUG_ON(ret != Z_OK);
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(HEADER_MAGIC);
header->bytenr = cpu_to_le64(start);
header->nritems = cpu_to_le32(0);
header->compress = md->compress_level > 0 ?
COMPRESS_ZLIB : COMPRESS_NONE;
}
static int metadump_init(struct metadump_struct *md, struct btrfs_root *root,
FILE *out, int num_threads, int compress_level)
{
int i, ret;
memset(md, 0, sizeof(*md));
pthread_cond_init(&md->cond, NULL);
pthread_mutex_init(&md->mutex, NULL);
INIT_LIST_HEAD(&md->list);
INIT_LIST_HEAD(&md->ordered);
md->root = root;
md->out = out;
md->pending_start = (u64)-1;
md->compress_level = compress_level;
md->cluster = calloc(1, BLOCK_SIZE);
if (!md->cluster)
return -ENOMEM;
meta_cluster_init(md, 0);
if (!num_threads)
return 0;
md->num_threads = num_threads;
md->threads = calloc(num_threads, sizeof(pthread_t));
if (!md->threads)
return -ENOMEM;
for (i = 0; i < num_threads; i++) {
ret = pthread_create(md->threads + i, NULL, dump_worker, md);
if (ret)
break;
}
return ret;
}
static void metadump_destroy(struct metadump_struct *md)
{
int i;
pthread_mutex_lock(&md->mutex);
md->done = 1;
pthread_cond_broadcast(&md->cond);
pthread_mutex_unlock(&md->mutex);
for (i = 0; i < md->num_threads; i++)
pthread_join(md->threads[i], NULL);
pthread_cond_destroy(&md->cond);
pthread_mutex_destroy(&md->mutex);
free(md->threads);
free(md->cluster);
}
static int write_zero(FILE *out, size_t size)
{
static char zero[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;
if (list_empty(&md->ordered))
goto out;
/* wait until all buffers are compressed */
while (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);
}
/* 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, BLOCK_SIZE, 1, md->out);
BUG_ON(ret != 1);
/* write buffers */
bytenr += le64_to_cpu(header->bytenr) + 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;
ret = fwrite(async->buffer, async->bufsize, 1, md->out);
BUG_ON(ret != 1);
free(async->buffer);
free(async);
}
/* zero unused space in the last block */
if (bytenr & BLOCK_MASK) {
size_t size = BLOCK_SIZE - (bytenr & BLOCK_MASK);
bytenr += size;
ret = write_zero(md->out, size);
BUG_ON(ret != 1);
}
out:
*next = bytenr;
return 0;
}
static int flush_pending(struct metadump_struct *md, int done)
{
struct async_work *async = NULL;
struct extent_buffer *eb;
u64 blocksize = md->root->nodesize;
u64 start;
u64 size;
size_t offset;
int ret;
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);
offset = 0;
start = async->start;
size = async->size;
while (size > 0) {
eb = read_tree_block(md->root, start, blocksize, 0);
BUG_ON(!eb);
copy_buffer(async->buffer + offset, eb);
free_extent_buffer(eb);
start += blocksize;
offset += blocksize;
size -= blocksize;
}
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);
BUG_ON(ret);
meta_cluster_init(md, start);
}
pthread_mutex_unlock(&md->mutex);
return 0;
}
static int add_metadata(u64 start, u64 size, struct metadump_struct *md)
{
int ret;
if (md->pending_size + size > 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, start, size, 0);
md->pending_size += size;
return 0;
}
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
static int is_tree_block(struct btrfs_root *extent_root,
struct btrfs_path *path, u64 bytenr)
{
struct extent_buffer *leaf;
struct btrfs_key key;
u64 ref_objectid;
int ret;
leaf = path->nodes[0];
while (1) {
struct btrfs_extent_ref_v0 *ref_item;
path->slots[0]++;
if (path->slots[0] >= btrfs_header_nritems(leaf)) {
ret = btrfs_next_leaf(extent_root, path);
BUG_ON(ret < 0);
if (ret > 0)
break;
leaf = path->nodes[0];
}
btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
if (key.objectid != bytenr)
break;
if (key.type != BTRFS_EXTENT_REF_V0_KEY)
continue;
ref_item = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_extent_ref_v0);
ref_objectid = btrfs_ref_objectid_v0(leaf, ref_item);
if (ref_objectid < BTRFS_FIRST_FREE_OBJECTID)
return 1;
break;
}
return 0;
}
#endif
static int create_metadump(const char *input, FILE *out, int num_threads,
int compress_level)
{
struct btrfs_root *root;
struct btrfs_root *extent_root;
struct btrfs_path *path;
struct extent_buffer *leaf;
struct btrfs_extent_item *ei;
struct btrfs_key key;
struct metadump_struct metadump;
u64 bytenr;
u64 num_bytes;
int ret;
root = open_ctree(input, 0, 0);
if (!root) {
fprintf(stderr, "Open ctree failed\n");
exit(1);
}
BUG_ON(root->nodesize != root->leafsize);
ret = metadump_init(&metadump, root, out, num_threads,
compress_level);
BUG_ON(ret);
ret = add_metadata(BTRFS_SUPER_INFO_OFFSET, 4096, &metadump);
BUG_ON(ret);
extent_root = root->fs_info->extent_root;
path = btrfs_alloc_path();
bytenr = BTRFS_SUPER_INFO_OFFSET + 4096;
key.objectid = bytenr;
key.type = BTRFS_EXTENT_ITEM_KEY;
key.offset = 0;
ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
BUG_ON(ret < 0);
while (1) {
leaf = path->nodes[0];
if (path->slots[0] >= btrfs_header_nritems(leaf)) {
ret = btrfs_next_leaf(extent_root, path);
BUG_ON(ret < 0);
if (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) {
path->slots[0]++;
continue;
}
bytenr = key.objectid;
num_bytes = key.offset;
if (btrfs_item_size_nr(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) {
ret = add_metadata(bytenr, num_bytes,
&metadump);
BUG_ON(ret);
}
} else {
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
if (is_tree_block(extent_root, path, bytenr)) {
ret = add_metadata(bytenr, num_bytes,
&metadump);
BUG_ON(ret);
}
#else
BUG_ON(1);
#endif
}
bytenr += num_bytes;
}
ret = flush_pending(&metadump, 1);
BUG_ON(ret);
metadump_destroy(&metadump);
btrfs_free_path(path);
ret = close_ctree(root);
return 0;
}
static void update_super(u8 *buffer)
{
struct btrfs_super_block *super = (struct btrfs_super_block *)buffer;
struct btrfs_chunk *chunk;
struct btrfs_disk_key *key;
u32 sectorsize = btrfs_super_sectorsize(super);
u64 flags = btrfs_super_flags(super);
flags |= BTRFS_SUPER_FLAG_METADUMP;
btrfs_set_super_flags(super, flags);
key = (struct btrfs_disk_key *)(super->sys_chunk_array);
chunk = (struct btrfs_chunk *)(super->sys_chunk_array +
sizeof(struct btrfs_disk_key));
btrfs_set_disk_key_objectid(key, BTRFS_FIRST_CHUNK_TREE_OBJECTID);
btrfs_set_disk_key_type(key, BTRFS_CHUNK_ITEM_KEY);
btrfs_set_disk_key_offset(key, 0);
btrfs_set_stack_chunk_length(chunk, (u64)-1);
btrfs_set_stack_chunk_owner(chunk, BTRFS_EXTENT_TREE_OBJECTID);
btrfs_set_stack_chunk_stripe_len(chunk, 64 * 1024);
btrfs_set_stack_chunk_type(chunk, BTRFS_BLOCK_GROUP_SYSTEM);
btrfs_set_stack_chunk_io_align(chunk, sectorsize);
btrfs_set_stack_chunk_io_width(chunk, sectorsize);
btrfs_set_stack_chunk_sector_size(chunk, sectorsize);
btrfs_set_stack_chunk_num_stripes(chunk, 1);
btrfs_set_stack_chunk_sub_stripes(chunk, 0);
chunk->stripe.devid = super->dev_item.devid;
chunk->stripe.offset = cpu_to_le64(0);
memcpy(chunk->stripe.dev_uuid, super->dev_item.uuid, BTRFS_UUID_SIZE);
btrfs_set_super_sys_array_size(super, sizeof(*key) + sizeof(*chunk));
csum_block(buffer, 4096);
}
static void *restore_worker(void *data)
{
struct mdrestore_struct *mdres = (struct mdrestore_struct *)data;
struct async_work *async;
size_t size;
u8 *buffer;
u8 *outbuf;
int outfd;
int ret;
outfd = fileno(mdres->out);
buffer = malloc(MAX_PENDING_SIZE * 2);
BUG_ON(!buffer);
while (1) {
pthread_mutex_lock(&mdres->mutex);
while (list_empty(&mdres->list)) {
if (mdres->done) {
pthread_mutex_unlock(&mdres->mutex);
goto out;
}
pthread_cond_wait(&mdres->cond, &mdres->mutex);
}
async = list_entry(mdres->list.next, struct async_work, list);
list_del_init(&async->list);
pthread_mutex_unlock(&mdres->mutex);
if (mdres->compress_method == COMPRESS_ZLIB) {
size = MAX_PENDING_SIZE * 2;
ret = uncompress(buffer, (unsigned long *)&size,
async->buffer, async->bufsize);
BUG_ON(ret != Z_OK);
outbuf = buffer;
} else {
outbuf = async->buffer;
size = async->bufsize;
}
if (async->start == BTRFS_SUPER_INFO_OFFSET)
update_super(outbuf);
ret = pwrite64(outfd, outbuf, size, async->start);
BUG_ON(ret != size);
pthread_mutex_lock(&mdres->mutex);
mdres->num_items--;
pthread_mutex_unlock(&mdres->mutex);
free(async->buffer);
free(async);
}
out:
free(buffer);
pthread_exit(NULL);
}
static int mdresotre_init(struct mdrestore_struct *mdres,
FILE *in, FILE *out, int num_threads)
{
int i, ret = 0;
memset(mdres, 0, sizeof(*mdres));
pthread_cond_init(&mdres->cond, NULL);
pthread_mutex_init(&mdres->mutex, NULL);
INIT_LIST_HEAD(&mdres->list);
mdres->in = in;
mdres->out = out;
if (!num_threads)
return 0;
mdres->num_threads = num_threads;
mdres->threads = calloc(num_threads, sizeof(pthread_t));
if (!mdres->threads)
return -ENOMEM;
for (i = 0; i < num_threads; i++) {
ret = pthread_create(mdres->threads + i, NULL, restore_worker,
mdres);
if (ret)
break;
}
return ret;
}
static void mdresotre_destroy(struct mdrestore_struct *mdres)
{
int i;
pthread_mutex_lock(&mdres->mutex);
mdres->done = 1;
pthread_cond_broadcast(&mdres->cond);
pthread_mutex_unlock(&mdres->mutex);
for (i = 0; i < mdres->num_threads; i++)
pthread_join(mdres->threads[i], NULL);
pthread_cond_destroy(&mdres->cond);
pthread_mutex_destroy(&mdres->mutex);
free(mdres->threads);
}
static int add_cluster(struct meta_cluster *cluster,
struct mdrestore_struct *mdres, u64 *next)
{
struct meta_cluster_item *item;
struct meta_cluster_header *header = &cluster->header;
struct async_work *async;
u64 bytenr;
u32 i, nritems;
int ret;
BUG_ON(mdres->num_items);
mdres->compress_method = header->compress;
bytenr = le64_to_cpu(header->bytenr) + BLOCK_SIZE;
nritems = le32_to_cpu(header->nritems);
for (i = 0; i < nritems; i++) {
item = &cluster->items[i];
async = calloc(1, sizeof(*async));
async->start = le64_to_cpu(item->bytenr);
async->bufsize = le32_to_cpu(item->size);
async->buffer = malloc(async->bufsize);
ret = fread(async->buffer, async->bufsize, 1, mdres->in);
BUG_ON(ret != 1);
bytenr += async->bufsize;
pthread_mutex_lock(&mdres->mutex);
list_add_tail(&async->list, &mdres->list);
mdres->num_items++;
pthread_cond_signal(&mdres->cond);
pthread_mutex_unlock(&mdres->mutex);
}
if (bytenr & BLOCK_MASK) {
char buffer[BLOCK_MASK];
size_t size = BLOCK_SIZE - (bytenr & BLOCK_MASK);
bytenr += size;
ret = fread(buffer, size, 1, mdres->in);
BUG_ON(ret != 1);
}
*next = bytenr;
return 0;
}
static int wait_for_worker(struct mdrestore_struct *mdres)
{
pthread_mutex_lock(&mdres->mutex);
while (mdres->num_items > 0) {
struct timespec ts = {
.tv_sec = 0,
.tv_nsec = 10000000,
};
pthread_mutex_unlock(&mdres->mutex);
nanosleep(&ts, NULL);
pthread_mutex_lock(&mdres->mutex);
}
pthread_mutex_unlock(&mdres->mutex);
return 0;
}
static int restore_metadump(const char *input, FILE *out, int num_threads)
{
struct meta_cluster *cluster;
struct meta_cluster_header *header;
struct mdrestore_struct mdrestore;
u64 bytenr = 0;
FILE *in;
int ret;
if (!strcmp(input, "-")) {
in = stdin;
} else {
in = fopen(input, "r");
if (!in) {
perror("unable to open metadump image");
return 1;
}
}
cluster = malloc(BLOCK_SIZE);
BUG_ON(!cluster);
ret = mdresotre_init(&mdrestore, in, out, num_threads);
BUG_ON(ret);
while (1) {
ret = fread(cluster, BLOCK_SIZE, 1, in);
if (!ret)
break;
header = &cluster->header;
if (le64_to_cpu(header->magic) != HEADER_MAGIC ||
le64_to_cpu(header->bytenr) != bytenr) {
fprintf(stderr, "bad header in metadump image\n");
return 1;
}
ret = add_cluster(cluster, &mdrestore, &bytenr);
BUG_ON(ret);
wait_for_worker(&mdrestore);
}
mdresotre_destroy(&mdrestore);
free(cluster);
if (in != stdin)
fclose(in);
return ret;
}
static void print_usage(void)
{
fprintf(stderr, "usage: btrfs-image [options] source target\n");
fprintf(stderr, "\t-r \trestore metadump image\n");
fprintf(stderr, "\t-c value\tcompression level (0 ~ 9)\n");
fprintf(stderr, "\t-t value\tnumber of threads (1 ~ 32)\n");
exit(1);
}
int main(int argc, char *argv[])
{
char *source;
char *target;
int num_threads = 0;
int compress_level = 0;
int create = 1;
int ret;
FILE *out;
while (1) {
int c = getopt(argc, argv, "rc:t:");
if (c < 0)
break;
switch (c) {
case 'r':
create = 0;
break;
case 't':
num_threads = atoi(optarg);
if (num_threads <= 0 || num_threads > 32)
print_usage();
break;
case 'c':
compress_level = atoi(optarg);
if (compress_level < 0 || compress_level > 9)
print_usage();
break;
default:
print_usage();
}
}
argc = argc - optind;
if (argc != 2)
print_usage();
source = argv[optind];
target = argv[optind + 1];
if (create && !strcmp(target, "-")) {
out = stdout;
} else {
out = fopen(target, "w+");
if (!out) {
perror("unable to create target file");
exit(1);
}
}
if (num_threads == 0 && compress_level > 0) {
num_threads = sysconf(_SC_NPROCESSORS_ONLN);
if (num_threads <= 0)
num_threads = 1;
}
if (create)
ret = create_metadump(source, out, num_threads,
compress_level);
else
ret = restore_metadump(source, out, 1);
if (out == stdout)
fflush(out);
else
fclose(out);
exit(ret);
}