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btrfs-progs/cmds/restore.c

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/*
* Copyright (C) 2011 Red Hat. 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 "kerncompat.h"
#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/types.h>
#if BTRFSRESTORE_LZO
#include <lzo/lzoconf.h>
#include <lzo/lzo1x.h>
#endif
#include <zlib.h>
#if BTRFSRESTORE_ZSTD
#include <zstd.h>
#endif
#include <regex.h>
#include <getopt.h>
#include <sys/types.h>
#include <sys/xattr.h>
#include "kernel-shared/ctree.h"
#include "kernel-shared/disk-io.h"
#include "kernel-shared/print-tree.h"
#include "kernel-shared/transaction.h"
#include "kernel-lib/list.h"
#include "kernel-shared/volumes.h"
#include "common/utils.h"
#include "cmds/commands.h"
#include "common/help.h"
#include "common/open-utils.h"
static char fs_name[PATH_MAX];
static char path_name[PATH_MAX];
static char symlink_target[PATH_MAX];
static int get_snaps = 0;
static int restore_metadata = 0;
static int restore_symlinks = 0;
static int ignore_errors = 0;
static int overwrite = 0;
static int get_xattrs = 0;
static int dry_run = 0;
#define LZO_LEN 4
#define lzo1x_worst_compress(x) ((x) + ((x) / 16) + 64 + 3)
static int decompress_zlib(char *inbuf, char *outbuf, u64 compress_len,
u64 decompress_len)
{
z_stream strm;
int ret;
memset(&strm, 0, sizeof(strm));
ret = inflateInit(&strm);
if (ret != Z_OK) {
error("zlib init returned %d", ret);
return -1;
}
strm.avail_in = compress_len;
strm.next_in = (unsigned char *)inbuf;
strm.avail_out = decompress_len;
strm.next_out = (unsigned char *)outbuf;
ret = inflate(&strm, Z_NO_FLUSH);
if (ret != Z_STREAM_END) {
(void)inflateEnd(&strm);
error("zlib inflate failed: %d", ret);
return -1;
}
(void)inflateEnd(&strm);
return 0;
}
static inline size_t read_compress_length(unsigned char *buf)
{
__le32 dlen;
memcpy(&dlen, buf, LZO_LEN);
return le32_to_cpu(dlen);
}
static int decompress_lzo(struct btrfs_root *root, unsigned char *inbuf,
char *outbuf, u64 compress_len, u64 *decompress_len)
{
#if !BTRFSRESTORE_LZO
error("btrfs-restore not compiled with lzo support");
return -1;
#else
size_t new_len;
size_t in_len;
size_t out_len = 0;
size_t tot_len;
size_t tot_in;
int ret;
ret = lzo_init();
if (ret != LZO_E_OK) {
error("lzo init returned %d", ret);
return -1;
}
tot_len = read_compress_length(inbuf);
inbuf += LZO_LEN;
tot_in = LZO_LEN;
while (tot_in < tot_len) {
size_t mod_page;
size_t rem_page;
in_len = read_compress_length(inbuf);
if ((tot_in + LZO_LEN + in_len) > tot_len) {
error("bad compress length %lu",
(unsigned long)in_len);
return -1;
}
inbuf += LZO_LEN;
tot_in += LZO_LEN;
new_len = lzo1x_worst_compress(root->fs_info->sectorsize);
ret = lzo1x_decompress_safe((const unsigned char *)inbuf, in_len,
(unsigned char *)outbuf,
(void *)&new_len, NULL);
if (ret != LZO_E_OK) {
error("lzo decompress failed: %d", ret);
return -1;
}
out_len += new_len;
outbuf += new_len;
inbuf += in_len;
tot_in += in_len;
/*
* If the 4 byte header does not fit to the rest of the page we
* have to move to the next one, unless we read some garbage
*/
mod_page = tot_in % root->fs_info->sectorsize;
rem_page = root->fs_info->sectorsize - mod_page;
if (rem_page < LZO_LEN) {
inbuf += rem_page;
tot_in += rem_page;
}
}
*decompress_len = out_len;
return 0;
#endif
}
static int decompress_zstd(const char *inbuf, char *outbuf, u64 compress_len,
u64 decompress_len)
{
#if !BTRFSRESTORE_ZSTD
error("btrfs not compiled with zstd support");
return -1;
#else
ZSTD_DStream *strm;
size_t zret;
int ret = 0;
ZSTD_inBuffer in = {inbuf, compress_len, 0};
ZSTD_outBuffer out = {outbuf, decompress_len, 0};
strm = ZSTD_createDStream();
if (!strm) {
error("zstd create failed");
return -1;
}
zret = ZSTD_initDStream(strm);
if (ZSTD_isError(zret)) {
error("zstd init failed: %s", ZSTD_getErrorName(zret));
ret = -1;
goto out;
}
zret = ZSTD_decompressStream(strm, &out, &in);
if (ZSTD_isError(zret)) {
error("zstd decompress failed %s\n", ZSTD_getErrorName(zret));
ret = -1;
goto out;
}
if (zret != 0) {
error("zstd frame incomplete");
ret = -1;
goto out;
}
out:
ZSTD_freeDStream(strm);
return ret;
#endif
}
static int decompress(struct btrfs_root *root, char *inbuf, char *outbuf,
u64 compress_len, u64 *decompress_len, int compress)
{
switch (compress) {
case BTRFS_COMPRESS_ZLIB:
return decompress_zlib(inbuf, outbuf, compress_len,
*decompress_len);
case BTRFS_COMPRESS_LZO:
return decompress_lzo(root, (unsigned char *)inbuf, outbuf,
compress_len, decompress_len);
case BTRFS_COMPRESS_ZSTD:
return decompress_zstd(inbuf, outbuf, compress_len,
*decompress_len);
default:
break;
}
error("invalid compression type: %d", compress);
return -1;
}
static int next_leaf(struct btrfs_root *root, struct btrfs_path *path)
{
int slot;
int level = 1;
int offset = 1;
struct extent_buffer *c;
struct extent_buffer *next = NULL;
struct btrfs_fs_info *fs_info = root->fs_info;
again:
for (; level < BTRFS_MAX_LEVEL; level++) {
if (path->nodes[level])
break;
}
if (level >= BTRFS_MAX_LEVEL)
return 1;
slot = path->slots[level] + 1;
while(level < BTRFS_MAX_LEVEL) {
if (!path->nodes[level])
return 1;
slot = path->slots[level] + offset;
c = path->nodes[level];
if (slot >= btrfs_header_nritems(c)) {
level++;
if (level == BTRFS_MAX_LEVEL)
return 1;
offset = 1;
continue;
}
if (path->reada)
reada_for_search(fs_info, path, level, slot, 0);
next = read_node_slot(fs_info, c, slot);
if (extent_buffer_uptodate(next))
break;
offset++;
}
path->slots[level] = slot;
while(1) {
level--;
c = path->nodes[level];
free_extent_buffer(c);
path->nodes[level] = next;
path->slots[level] = 0;
if (!level)
break;
if (path->reada)
reada_for_search(fs_info, path, level, 0, 0);
next = read_node_slot(fs_info, next, 0);
if (!extent_buffer_uptodate(next))
goto again;
}
return 0;
}
static int copy_one_inline(struct btrfs_root *root, int fd,
struct btrfs_path *path, u64 pos)
{
struct extent_buffer *leaf = path->nodes[0];
struct btrfs_file_extent_item *fi;
char buf[4096];
char *outbuf;
u64 ram_size;
ssize_t done;
unsigned long ptr;
int ret;
int len;
int inline_item_len;
int compress;
fi = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_file_extent_item);
ptr = btrfs_file_extent_inline_start(fi);
len = btrfs_file_extent_ram_bytes(leaf, fi);
inline_item_len = btrfs_file_extent_inline_item_len(leaf, path->slots[0]);
read_extent_buffer(leaf, buf, ptr, inline_item_len);
compress = btrfs_file_extent_compression(leaf, fi);
if (compress == BTRFS_COMPRESS_NONE) {
done = pwrite(fd, buf, len, pos);
if (done < len) {
error("short inline write, wanted %d, did %zd: %m",
len, done);
return -1;
}
return 0;
}
ram_size = btrfs_file_extent_ram_bytes(leaf, fi);
outbuf = calloc(1, ram_size);
if (!outbuf) {
error("not enough memory");
return -ENOMEM;
}
ret = decompress(root, buf, outbuf, inline_item_len, &ram_size,
compress);
if (ret) {
free(outbuf);
return ret;
}
done = pwrite(fd, outbuf, ram_size, pos);
free(outbuf);
if (done < ram_size) {
error("short compressed inline write, wanted %llu, did %zd: %m",
ram_size, done);
return -1;
}
return 0;
}
static int copy_one_extent(struct btrfs_root *root, int fd,
struct extent_buffer *leaf,
struct btrfs_file_extent_item *fi, u64 pos)
{
char *inbuf, *outbuf = NULL;
ssize_t done, total = 0;
u64 bytenr;
u64 ram_size;
u64 disk_size;
u64 num_bytes;
u64 length;
u64 size_left;
u64 offset;
u64 cur;
int compress;
int ret;
int mirror_num = 1;
int num_copies;
compress = btrfs_file_extent_compression(leaf, fi);
bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
disk_size = btrfs_file_extent_disk_num_bytes(leaf, fi);
ram_size = btrfs_file_extent_ram_bytes(leaf, fi);
offset = btrfs_file_extent_offset(leaf, fi);
num_bytes = btrfs_file_extent_num_bytes(leaf, fi);
size_left = disk_size;
/* Hole, early exit */
if (disk_size == 0)
return 0;
/* Invalid file extent */
if ((compress == BTRFS_COMPRESS_NONE && offset >= disk_size) ||
offset > ram_size) {
error(
"invalid data extent offset, offset %llu disk_size %llu ram_size %llu",
offset, disk_size, ram_size);
return -EUCLEAN;
}
if (compress == BTRFS_COMPRESS_NONE && offset < disk_size) {
bytenr += offset;
size_left -= offset;
}
pr_verbose(offset ? 1 : 0, "offset is %llu\n", offset);
inbuf = malloc(size_left);
if (!inbuf) {
error("not enough memory");
return -ENOMEM;
}
if (compress != BTRFS_COMPRESS_NONE) {
outbuf = calloc(1, ram_size);
if (!outbuf) {
error("not enough memory");
free(inbuf);
return -ENOMEM;
}
}
num_copies = btrfs_num_copies(root->fs_info, bytenr, disk_size - offset);
again:
cur = bytenr;
while (cur < bytenr + size_left) {
length = bytenr + size_left - cur;
ret = read_data_from_disk(root->fs_info, inbuf + cur - bytenr, cur,
&length, mirror_num);
if (ret < 0) {
mirror_num++;
if (mirror_num > num_copies) {
ret = -1;
error("exhausted mirrors trying to read (%d > %d)",
mirror_num, num_copies);
goto out;
}
fprintf(stderr, "trying another mirror\n");
continue;
}
cur += length;
}
if (compress == BTRFS_COMPRESS_NONE) {
while (total < num_bytes) {
done = pwrite(fd, inbuf+total, num_bytes-total,
pos+total);
if (done < 0) {
ret = -1;
error("cannot write data: %d %m", errno);
goto out;
}
total += done;
}
ret = 0;
goto out;
}
ret = decompress(root, inbuf, outbuf, disk_size, &ram_size, compress);
if (ret) {
mirror_num++;
if (mirror_num > num_copies) {
ret = -1;
goto out;
}
fprintf(stderr,
"trying another mirror due to decompression error\n");
goto again;
}
while (total < num_bytes) {
done = pwrite(fd, outbuf + offset + total,
num_bytes - total,
pos + total);
if (done < 0) {
ret = -1;
goto out;
}
total += done;
}
out:
free(inbuf);
free(outbuf);
return ret;
}
static int set_file_xattrs(struct btrfs_root *root, u64 inode,
int fd, const char *file_name)
{
struct btrfs_key key;
struct btrfs_path path;
struct extent_buffer *leaf;
struct btrfs_dir_item *di;
u32 name_len = 0;
u32 data_len = 0;
u32 len = 0;
u32 cur, total_len;
char *name = NULL;
char *data = NULL;
int ret = 0;
btrfs_init_path(&path);
key.objectid = inode;
key.type = BTRFS_XATTR_ITEM_KEY;
key.offset = 0;
ret = btrfs_search_slot(NULL, root, &key, &path, 0, 0);
if (ret < 0)
goto out;
leaf = path.nodes[0];
while (1) {
if (path.slots[0] >= btrfs_header_nritems(leaf)) {
do {
ret = next_leaf(root, &path);
if (ret < 0) {
error("searching for extended attributes: %d",
ret);
goto out;
} else if (ret) {
/* No more leaves to search */
ret = 0;
goto out;
}
leaf = path.nodes[0];
} while (!leaf);
continue;
}
btrfs_item_key_to_cpu(leaf, &key, path.slots[0]);
if (key.type != BTRFS_XATTR_ITEM_KEY || key.objectid != inode)
break;
cur = 0;
total_len = btrfs_item_size(leaf, path.slots[0]);
di = btrfs_item_ptr(leaf, path.slots[0],
struct btrfs_dir_item);
while (cur < total_len) {
len = btrfs_dir_name_len(leaf, di);
if (len > name_len) {
free(name);
name = (char *) malloc(len + 1);
if (!name) {
ret = -ENOMEM;
goto out;
}
}
read_extent_buffer(leaf, name,
(unsigned long)(di + 1), len);
name[len] = '\0';
name_len = len;
len = btrfs_dir_data_len(leaf, di);
if (len > data_len) {
free(data);
data = (char *) malloc(len);
if (!data) {
ret = -ENOMEM;
goto out;
}
}
read_extent_buffer(leaf, data,
(unsigned long)(di + 1) + name_len,
len);
data_len = len;
if (fsetxattr(fd, name, data, data_len, 0))
error("setting extended attribute %s on file %s: %m",
name, file_name);
len = sizeof(*di) + name_len + data_len;
cur += len;
di = (struct btrfs_dir_item *)((char *)di + len);
}
path.slots[0]++;
}
ret = 0;
out:
btrfs_release_path(&path);
free(name);
free(data);
return ret;
}
static int copy_metadata(struct btrfs_root *root, int fd,
struct btrfs_key *key)
{
struct btrfs_path path;
struct btrfs_inode_item *inode_item;
int ret;
btrfs_init_path(&path);
ret = btrfs_lookup_inode(NULL, root, &path, key, 0);
if (ret == 0) {
struct btrfs_timespec *bts;
struct timespec times[2];
inode_item = btrfs_item_ptr(path.nodes[0], path.slots[0],
struct btrfs_inode_item);
ret = fchown(fd, btrfs_inode_uid(path.nodes[0], inode_item),
btrfs_inode_gid(path.nodes[0], inode_item));
if (ret) {
error("failed to change owner: %m");
goto out;
}
ret = fchmod(fd, btrfs_inode_mode(path.nodes[0], inode_item));
if (ret) {
error("failed to change mode: %m");
goto out;
}
bts = btrfs_inode_atime(inode_item);
times[0].tv_sec = btrfs_timespec_sec(path.nodes[0], bts);
times[0].tv_nsec = btrfs_timespec_nsec(path.nodes[0], bts);
bts = btrfs_inode_mtime(inode_item);
times[1].tv_sec = btrfs_timespec_sec(path.nodes[0], bts);
times[1].tv_nsec = btrfs_timespec_nsec(path.nodes[0], bts);
ret = futimens(fd, times);
if (ret) {
error("failed to set times: %m");
goto out;
}
}
out:
btrfs_release_path(&path);
return ret;
}
static int copy_file(struct btrfs_root *root, int fd, struct btrfs_key *key,
const char *file)
{
struct extent_buffer *leaf;
struct btrfs_path path;
struct btrfs_file_extent_item *fi;
struct btrfs_inode_item *inode_item;
struct btrfs_timespec *bts;
struct btrfs_key found_key;
int ret;
int extent_type;
int compression;
u64 found_size = 0;
struct timespec times[2];
int times_ok = 0;
btrfs_init_path(&path);
ret = btrfs_lookup_inode(NULL, root, &path, key, 0);
if (ret == 0) {
inode_item = btrfs_item_ptr(path.nodes[0], path.slots[0],
struct btrfs_inode_item);
found_size = btrfs_inode_size(path.nodes[0], inode_item);
if (restore_metadata) {
/*
* Change the ownership and mode now, set times when
* copyout is finished.
*/
ret = fchown(fd, btrfs_inode_uid(path.nodes[0], inode_item),
btrfs_inode_gid(path.nodes[0], inode_item));
if (ret && !ignore_errors)
goto out;
ret = fchmod(fd, btrfs_inode_mode(path.nodes[0], inode_item));
if (ret && !ignore_errors)
goto out;
bts = btrfs_inode_atime(inode_item);
times[0].tv_sec = btrfs_timespec_sec(path.nodes[0], bts);
times[0].tv_nsec = btrfs_timespec_nsec(path.nodes[0], bts);
bts = btrfs_inode_mtime(inode_item);
times[1].tv_sec = btrfs_timespec_sec(path.nodes[0], bts);
times[1].tv_nsec = btrfs_timespec_nsec(path.nodes[0], bts);
times_ok = 1;
}
}
btrfs_release_path(&path);
key->offset = 0;
key->type = BTRFS_EXTENT_DATA_KEY;
ret = btrfs_search_slot(NULL, root, key, &path, 0, 0);
if (ret < 0) {
error("searching extent data returned %d", ret);
goto out;
}
leaf = path.nodes[0];
while (!leaf) {
ret = next_leaf(root, &path);
if (ret < 0) {
error("cannot get next leaf: %d", ret);
goto out;
} else if (ret > 0) {
/* No more leaves to search */
ret = 0;
goto out;
}
leaf = path.nodes[0];
}
while (1) {
if (path.slots[0] >= btrfs_header_nritems(leaf)) {
do {
ret = next_leaf(root, &path);
if (ret < 0) {
error("search to next leaf failed: %d", ret);
goto out;
} else if (ret) {
/* No more leaves to search */
btrfs_release_path(&path);
goto set_size;
}
leaf = path.nodes[0];
} while (!leaf);
continue;
}
btrfs_item_key_to_cpu(leaf, &found_key, path.slots[0]);
if (found_key.objectid != key->objectid)
break;
if (found_key.type != key->type)
break;
fi = btrfs_item_ptr(leaf, path.slots[0],
struct btrfs_file_extent_item);
extent_type = btrfs_file_extent_type(leaf, fi);
compression = btrfs_file_extent_compression(leaf, fi);
if (compression >= BTRFS_COMPRESS_LAST) {
warning("compression type %d not supported",
compression);
ret = -1;
goto out;
}
if (extent_type == BTRFS_FILE_EXTENT_PREALLOC)
goto next;
if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
ret = copy_one_inline(root, fd, &path, found_key.offset);
if (ret)
goto out;
} else if (extent_type == BTRFS_FILE_EXTENT_REG) {
ret = copy_one_extent(root, fd, leaf, fi,
found_key.offset);
if (ret)
goto out;
} else {
warning("weird extent type %d", extent_type);
}
next:
path.slots[0]++;
}
btrfs_release_path(&path);
set_size:
if (found_size) {
ret = ftruncate(fd, (loff_t)found_size);
if (ret)
return ret;
}
if (get_xattrs) {
ret = set_file_xattrs(root, key->objectid, fd, file);
if (ret)
return ret;
}
if (restore_metadata && times_ok) {
ret = futimens(fd, times);
if (ret)
return ret;
}
return 0;
out:
btrfs_release_path(&path);
return ret;
}
/*
* returns:
* 0 if the file exists and should be skipped.
* 1 if the file does NOT exist
* 2 if the file exists but is OK to overwrite
*/
static int overwrite_ok(const char * path)
{
static int warn = 0;
struct stat st;
int ret;
/* don't be fooled by symlinks */
ret = fstatat(AT_FDCWD, path_name, &st, AT_SYMLINK_NOFOLLOW);
if (!ret) {
if (overwrite)
return 2;
if (!warn) {
pr_verbose(-1, "Skipping existing file %s\n", path);
pr_verbose(-1, "If you wish to overwrite use -o\n");
} else {
pr_verbose(1, "Skipping existing file %s\n", path);
}
warn = 1;
return 0;
}
return 1;
}
static int copy_symlink(struct btrfs_root *root, struct btrfs_key *key,
const char *file)
{
struct btrfs_path path;
struct extent_buffer *leaf;
struct btrfs_file_extent_item *extent_item;
struct btrfs_inode_item *inode_item;
u32 len;
u32 name_offset;
int ret;
struct btrfs_timespec *bts;
struct timespec times[2];
ret = overwrite_ok(path_name);
if (ret == 0)
return 0; /* skip this file */
/* symlink() can't overwrite, so unlink first */
if (ret == 2) {
ret = unlink(path_name);
if (ret) {
error("failed to unlink '%s' for overwrite: %m", path_name);
return ret;
}
}
btrfs_init_path(&path);
key->type = BTRFS_EXTENT_DATA_KEY;
key->offset = 0;
ret = btrfs_search_slot(NULL, root, key, &path, 0, 0);
if (ret < 0)
goto out;
leaf = path.nodes[0];
if (!leaf) {
error("failed to get leaf for symlink '%s'", file);
ret = -1;
goto out;
}
extent_item = btrfs_item_ptr(leaf, path.slots[0],
struct btrfs_file_extent_item);
len = btrfs_file_extent_inline_item_len(leaf, path.slots[0]);
if (len >= PATH_MAX) {
error("symlink '%s' target length %d is longer than PATH_MAX",
fs_name, len);
ret = -1;
goto out;
}
name_offset = (unsigned long) extent_item
+ offsetof(struct btrfs_file_extent_item, disk_bytenr);
read_extent_buffer(leaf, symlink_target, name_offset, len);
symlink_target[len] = 0;
if (!dry_run) {
ret = symlink(symlink_target, path_name);
if (ret < 0) {
error("failed to restore symlink '%s': %m", path_name);
goto out;
}
}
if (bconf.verbose >= 2)
printf("SYMLINK: '%s' => '%s'\n", path_name, symlink_target);
ret = 0;
if (!restore_metadata)
goto out;
/*
* Symlink metadata operates differently than files/directories, so do
* our own work here.
*/
key->type = BTRFS_INODE_ITEM_KEY;
key->offset = 0;
btrfs_release_path(&path);
ret = btrfs_lookup_inode(NULL, root, &path, key, 0);
if (ret) {
error("failed to lookup inode for '%s'", file);
goto out;
}
inode_item = btrfs_item_ptr(path.nodes[0], path.slots[0],
struct btrfs_inode_item);
ret = fchownat(AT_FDCWD, file, btrfs_inode_uid(path.nodes[0], inode_item),
btrfs_inode_gid(path.nodes[0], inode_item),
AT_SYMLINK_NOFOLLOW);
if (ret) {
error("failed to change owner of '%s': %m", file);
goto out;
}
bts = btrfs_inode_atime(inode_item);
times[0].tv_sec = btrfs_timespec_sec(path.nodes[0], bts);
times[0].tv_nsec = btrfs_timespec_nsec(path.nodes[0], bts);
bts = btrfs_inode_mtime(inode_item);
times[1].tv_sec = btrfs_timespec_sec(path.nodes[0], bts);
times[1].tv_nsec = btrfs_timespec_nsec(path.nodes[0], bts);
ret = utimensat(AT_FDCWD, file, times, AT_SYMLINK_NOFOLLOW);
if (ret)
error("failed to set times for '%s': %m", file);
out:
btrfs_release_path(&path);
return ret;
}
static int search_dir(struct btrfs_root *root, struct btrfs_key *key,
const char *output_rootdir, const char *in_dir,
const regex_t *mreg)
{
struct btrfs_path path;
struct extent_buffer *leaf;
struct btrfs_dir_item *dir_item;
struct btrfs_key found_key, location;
char filename[BTRFS_NAME_LEN + 1];
unsigned long name_ptr;
int name_len;
int ret = 0;
int fd;
u8 type;
btrfs_init_path(&path);
key->offset = 0;
key->type = BTRFS_DIR_INDEX_KEY;
ret = btrfs_search_slot(NULL, root, key, &path, 0, 0);
if (ret < 0) {
error("search for next directory entry failed: %d", ret);
goto out;
}
ret = 0;
leaf = path.nodes[0];
while (!leaf) {
pr_verbose(2,
"No leaf after search, looking for the next leaf\n");
ret = next_leaf(root, &path);
if (ret < 0) {
error("search for next leaf failed: %d", ret);
goto out;
} else if (ret > 0) {
/* No more leaves to search */
pr_verbose(1,
"Reached the end of the tree looking for the directory\n");
ret = 0;
goto out;
}
leaf = path.nodes[0];
}
while (leaf) {
if (path.slots[0] >= btrfs_header_nritems(leaf)) {
do {
ret = next_leaf(root, &path);
if (ret < 0) {
error("search for next leaf failed: %d", ret);
goto out;
} else if (ret > 0) {
/* No more leaves to search */
pr_verbose(1,
"Reached the end of the tree searching the directory\n");
ret = 0;
goto out;
}
leaf = path.nodes[0];
} while (!leaf);
continue;
}
btrfs_item_key_to_cpu(leaf, &found_key, path.slots[0]);
if (found_key.objectid != key->objectid) {
pr_verbose(2, "Found objectid=%llu, key=%llu\n",
found_key.objectid, key->objectid);
break;
}
if (found_key.type != key->type) {
pr_verbose(2, "Found type=%u, want=%u\n",
found_key.type, key->type);
break;
}
dir_item = btrfs_item_ptr(leaf, path.slots[0],
struct btrfs_dir_item);
name_ptr = (unsigned long)(dir_item + 1);
name_len = btrfs_dir_name_len(leaf, dir_item);
read_extent_buffer(leaf, filename, name_ptr, name_len);
filename[name_len] = '\0';
type = btrfs_dir_type(leaf, dir_item);
btrfs_dir_item_key_to_cpu(leaf, dir_item, &location);
/* full path from root of btrfs being restored */
snprintf(fs_name, PATH_MAX, "%s/%s", in_dir, filename);
if (mreg && REG_NOMATCH == regexec(mreg, fs_name, 0, NULL, 0))
goto next;
/* full path from system root */
snprintf(path_name, PATH_MAX, "%s%s", output_rootdir, fs_name);
/*
* Restore directories, files, symlinks and metadata.
*/
if (type == BTRFS_FT_REG_FILE) {
if (!overwrite_ok(path_name))
goto next;
pr_verbose(1, "Restoring %s\n", path_name);
if (dry_run)
goto next;
fd = open(path_name, O_CREAT|O_WRONLY, 0644);
if (fd < 0) {
error("creating '%s' failed: %m", path_name);
if (ignore_errors)
goto next;
ret = -1;
goto out;
}
ret = copy_file(root, fd, &location, path_name);
close(fd);
if (ret) {
error("copying data for %s failed", path_name);
if (ignore_errors)
goto next;
goto out;
}
} else if (type == BTRFS_FT_DIR) {
struct btrfs_root *search_root = root;
char *dir = strdup(fs_name);
if (!dir) {
error("ran out of memory");
ret = -ENOMEM;
goto out;
}
if (location.type == BTRFS_ROOT_ITEM_KEY) {
/*
* If we are a snapshot and this is the index
* object to ourselves just skip it.
*/
if (location.objectid ==
root->root_key.objectid) {
free(dir);
goto next;
}
location.offset = (u64)-1;
search_root = btrfs_read_fs_root(root->fs_info,
&location);
if (IS_ERR(search_root)) {
free(dir);
error("reading subvolume %s failed: %lu",
path_name, PTR_ERR(search_root));
if (ignore_errors)
goto next;
ret = PTR_ERR(search_root);
goto out;
}
/*
* A subvolume will have a key.offset of 0, a
* snapshot will have key.offset of a transid.
*/
if (search_root->root_key.offset != 0 &&
get_snaps == 0) {
free(dir);
printf("Skipping snapshot %s\n", filename);
goto next;
}
location.objectid = BTRFS_FIRST_FREE_OBJECTID;
}
pr_verbose(1, "Restoring %s\n", path_name);
errno = 0;
if (dry_run)
ret = 0;
else
ret = mkdir(path_name, 0755);
if (ret && errno != EEXIST) {
free(dir);
error("failed mkdir %s: %m", path_name);
if (ignore_errors)
goto next;
ret = -1;
goto out;
}
ret = search_dir(search_root, &location,
output_rootdir, dir, mreg);
free(dir);
if (ret) {
error("searching directory %s failed: %d",
path_name, ret);
if (ignore_errors)
goto next;
goto out;
}
} else if (type == BTRFS_FT_SYMLINK) {
if (restore_symlinks)
ret = copy_symlink(root, &location, path_name);
if (ret < 0) {
if (ignore_errors)
goto next;
btrfs_release_path(&path);
return ret;
}
}
next:
path.slots[0]++;
}
if (restore_metadata) {
snprintf(path_name, PATH_MAX, "%s%s", output_rootdir, in_dir);
fd = open(path_name, O_RDONLY);
if (fd < 0) {
error("failed to access '%s' to restore metadata: %m",
path_name);
if (!ignore_errors) {
ret = -1;
goto out;
}
} else {
/*
* Set owner/mode/time on the directory as well
*/
key->type = BTRFS_INODE_ITEM_KEY;
ret = copy_metadata(root, fd, key);
close(fd);
if (ret && !ignore_errors)
goto out;
}
}
pr_verbose(1, "Done searching %s\n", in_dir);
out:
btrfs_release_path(&path);
return ret;
}
static int do_list_roots(struct btrfs_root *root)
{
struct btrfs_key key;
struct btrfs_key found_key;
struct btrfs_disk_key disk_key;
struct btrfs_path path;
struct extent_buffer *leaf;
struct btrfs_root_item ri;
unsigned long offset;
int slot;
int ret;
root = root->fs_info->tree_root;
btrfs_init_path(&path);
key.offset = 0;
key.objectid = 0;
key.type = BTRFS_ROOT_ITEM_KEY;
ret = btrfs_search_slot(NULL, root, &key, &path, 0, 0);
if (ret < 0) {
error("failed search next root item: %d", ret);
btrfs_release_path(&path);
return -1;
}
leaf = path.nodes[0];
while (1) {
slot = path.slots[0];
if (slot >= btrfs_header_nritems(leaf)) {
ret = btrfs_next_leaf(root, &path);
if (ret)
break;
leaf = path.nodes[0];
slot = path.slots[0];
}
btrfs_item_key(leaf, &disk_key, slot);
btrfs_disk_key_to_cpu(&found_key, &disk_key);
if (found_key.type != BTRFS_ROOT_ITEM_KEY) {
path.slots[0]++;
continue;
}
offset = btrfs_item_ptr_offset(leaf, slot);
read_extent_buffer(leaf, &ri, offset, sizeof(ri));
printf(" tree ");
btrfs_print_key(&disk_key);
printf(" %llu level %d\n", btrfs_root_bytenr(&ri),
btrfs_root_level(&ri));
path.slots[0]++;
}
btrfs_release_path(&path);
return 0;
}
static struct btrfs_root *open_fs(const char *dev, u64 root_location,
int super_mirror, int list_roots)
{
struct btrfs_fs_info *fs_info = NULL;
struct btrfs_root *root = NULL;
struct open_ctree_flags ocf = { 0 };
u64 bytenr;
int i;
for (i = super_mirror; i < BTRFS_SUPER_MIRROR_MAX; i++) {
bytenr = btrfs_sb_offset(i);
/*
* Restore won't allocate extent and doesn't care anything
* in extent tree. Skip block group item search will allow
* restore to be executed on heavily damaged fs.
*/
ocf.filename = dev;
ocf.sb_bytenr = bytenr;
ocf.root_tree_bytenr = root_location;
ocf.flags = OPEN_CTREE_PARTIAL | OPEN_CTREE_NO_BLOCK_GROUPS |
OPEN_CTREE_ALLOW_TRANSID_MISMATCH;
fs_info = open_ctree_fs_info(&ocf);
if (fs_info)
break;
fprintf(stderr, "Could not open root, trying backup super\n");
}
if (!fs_info)
return NULL;
/*
* All we really need to succeed is reading the chunk tree, everything
* else we can do by hand, since we only need to read the tree root and
* the fs_root.
*/
if (!extent_buffer_uptodate(fs_info->tree_root->node)) {
u64 generation;
root = fs_info->tree_root;
if (!root_location)
root_location = btrfs_super_root(fs_info->super_copy);
generation = btrfs_super_generation(fs_info->super_copy);
root->node = read_tree_block(fs_info, root_location,
generation);
if (!extent_buffer_uptodate(root->node)) {
error("opening tree root failed");
close_ctree(root);
return NULL;
}
}
if (!list_roots && !fs_info->fs_root) {
struct btrfs_key key;
key.objectid = BTRFS_FS_TREE_OBJECTID;
key.type = BTRFS_ROOT_ITEM_KEY;
key.offset = (u64)-1;
fs_info->fs_root = btrfs_read_fs_root_no_cache(fs_info, &key);
if (IS_ERR(fs_info->fs_root)) {
error("could not read fs root: %ld", PTR_ERR(fs_info->fs_root));
close_ctree(fs_info->tree_root);
return NULL;
}
}
if (list_roots && do_list_roots(fs_info->tree_root)) {
close_ctree(fs_info->tree_root);
return NULL;
}
return fs_info->fs_root;
}
static int find_first_dir(struct btrfs_root *root, u64 *objectid)
{
struct btrfs_path path;
struct btrfs_key found_key;
struct btrfs_key key;
int ret = -1;
int i;
btrfs_init_path(&path);
key.objectid = 0;
key.type = BTRFS_DIR_INDEX_KEY;
key.offset = 0;
ret = btrfs_search_slot(NULL, root, &key, &path, 0, 0);
if (ret < 0) {
error("searching next directory entry failed: %d", ret);
goto out;
}
if (!path.nodes[0]) {
error("no leaf when looking for directory");
goto out;
}
again:
for (i = path.slots[0];
i < btrfs_header_nritems(path.nodes[0]); i++) {
btrfs_item_key_to_cpu(path.nodes[0], &found_key, i);
if (found_key.type != key.type)
continue;
printf("Using objectid %llu for first dir\n",
found_key.objectid);
*objectid = found_key.objectid;
ret = 0;
goto out;
}
do {
ret = next_leaf(root, &path);
if (ret < 0) {
error("search for next leaf failed: %d", ret);
goto out;
} else if (ret > 0) {
error("no more leaves to search");
goto out;
}
} while (!path.nodes[0]);
if (path.nodes[0])
goto again;
printf("Couldn't find a dir index item\n");
out:
btrfs_release_path(&path);
return ret;
}
static const char * const cmd_restore_usage[] = {
"btrfs restore [options] <device> <path>\n"
"btrfs restore [options] -l <device>",
"Try to restore files from a damaged filesystem (unmounted)",
"",
" control:",
" -D|--dry-run dry run (only list files that would be recovered)",
" -i|--ignore-errors ignore errors",
" -o|--overwrite overwrite",
" restoration:",
" -m|--metadata restore owner, mode and times",
" -S|--symlink restore symbolic links",
" -s|--snapshots get snapshots",
" -x|--xattr restore extended attributes",
" filtering:",
" --path-regex <regex>",
" restore only filenames matching regex,",
" you have to use following syntax (possibly quoted):",
" ^/(|home(|/username(|/Desktop(|/.*))))$",
" -c ignore case (--path-regex only)",
" analysis:",
" -d find dir",
" -l|--list-roots list tree roots",
" alternate starting point:",
" -f <bytenr> filesystem location",
" -r|--root <rootid> root objectid",
" -t <bytenr> tree location",
" -u|--super <mirror> super mirror",
" other:",
" -v|--verbose deprecated, alias for global -v option",
HELPINFO_INSERT_GLOBALS,
HELPINFO_INSERT_VERBOSE,
"",
"Compression support: zlib"
#if BTRFSRESTORE_LZO
", lzo"
#endif
#if BTRFSRESTORE_ZSTD
", zstd"
#endif
,
NULL
};
static int cmd_restore(const struct cmd_struct *cmd, int argc, char **argv)
{
struct btrfs_root *root;
struct btrfs_key key;
char dir_name[PATH_MAX];
u64 tree_location = 0;
u64 fs_location = 0;
u64 root_objectid = 0;
int len;
int ret;
int super_mirror = 0;
int find_dir = 0;
int list_roots = 0;
const char *match_regstr = NULL;
int match_cflags = REG_EXTENDED | REG_NOSUB | REG_NEWLINE;
regex_t match_reg, *mreg = NULL;
char reg_err[256];
optind = 0;
while (1) {
int opt;
enum { GETOPT_VAL_PATH_REGEX = 256 };
static const struct option long_options[] = {
{ "path-regex", required_argument, NULL,
GETOPT_VAL_PATH_REGEX },
{ "dry-run", no_argument, NULL, 'D'},
{ "metadata", no_argument, NULL, 'm'},
{ "symlinks", no_argument, NULL, 'S'},
{ "snapshots", no_argument, NULL, 's'},
{ "xattr", no_argument, NULL, 'x'},
{ "verbose", no_argument, NULL, 'v'},
{ "ignore-errors", no_argument, NULL, 'i'},
{ "overwrite", no_argument, NULL, 'o'},
{ "super", required_argument, NULL, 'u'},
{ "root", required_argument, NULL, 'r'},
{ "list-roots", no_argument, NULL, 'l'},
{ NULL, 0, NULL, 0}
};
opt = getopt_long(argc, argv, "sSxviot:u:dmf:r:lDc", long_options,
NULL);
if (opt < 0)
break;
switch (opt) {
case 's':
get_snaps = 1;
break;
case 'v':
bconf_be_verbose();
break;
case 'i':
ignore_errors = 1;
break;
case 'o':
overwrite = 1;
break;
case 't':
tree_location = arg_strtou64(optarg);
break;
case 'f':
fs_location = arg_strtou64(optarg);
break;
case 'u':
super_mirror = arg_strtou64(optarg);
if (super_mirror >= BTRFS_SUPER_MIRROR_MAX) {
error("super mirror %d not valid",
super_mirror);
exit(1);
}
break;
case 'd':
find_dir = 1;
break;
case 'r':
root_objectid = arg_strtou64(optarg);
if (!is_fstree(root_objectid)) {
error("objectid %llu is not a valid fs/file tree",
root_objectid);
exit(1);
}
break;
case 'l':
list_roots = 1;
break;
case 'm':
restore_metadata = 1;
break;
case 'S':
restore_symlinks = 1;
break;
case 'D':
dry_run = 1;
break;
case 'c':
match_cflags |= REG_ICASE;
break;
case GETOPT_VAL_PATH_REGEX:
match_regstr = optarg;
break;
case 'x':
get_xattrs = 1;
break;
default:
usage_unknown_option(cmd, argv);
}
}
if (!list_roots && check_argc_min(argc - optind, 2))
usage(cmd);
else if (list_roots && check_argc_min(argc - optind, 1))
usage(cmd);
if (fs_location && root_objectid) {
error("can't use -f and -r at the same time");
return 1;
}
if ((ret = check_mounted(argv[optind])) < 0) {
errno = -ret;
error("could not check mount status: %m");
return 1;
} else if (ret) {
error("%s is currently mounted, cannot continue", argv[optind]);
return 1;
}
root = open_fs(argv[optind], tree_location, super_mirror, list_roots);
if (root == NULL)
return 1;
if (list_roots)
goto out;
if (fs_location != 0) {
free_extent_buffer(root->node);
root->node = read_tree_block(root->fs_info, fs_location, 0);
if (!extent_buffer_uptodate(root->node)) {
error("failed to read fs location");
ret = 1;
goto out;
}
}
memset(path_name, 0, PATH_MAX);
if (strlen(argv[optind + 1]) >= PATH_MAX) {
error("path '%s' too long", argv[optind + 1]);
ret = 1;
goto out;
}
strncpy(dir_name, argv[optind + 1], sizeof dir_name);
dir_name[sizeof dir_name - 1] = 0;
/* Strip the trailing / on the dir name */
len = strlen(dir_name);
while (len && dir_name[--len] == '/') {
dir_name[len] = '\0';
}
if (root_objectid != 0) {
struct btrfs_root *orig_root = root;
key.objectid = root_objectid;
key.type = BTRFS_ROOT_ITEM_KEY;
key.offset = (u64)-1;
root = btrfs_read_fs_root(orig_root->fs_info, &key);
if (IS_ERR(root)) {
errno = -PTR_ERR(root);
error("failed to read root %llu: %m", root_objectid);
root = orig_root;
ret = 1;
goto out;
}
key.type = 0;
key.offset = 0;
}
if (find_dir) {
ret = find_first_dir(root, &key.objectid);
if (ret)
goto out;
} else {
key.objectid = BTRFS_FIRST_FREE_OBJECTID;
}
if (match_regstr) {
ret = regcomp(&match_reg, match_regstr, match_cflags);
if (ret) {
regerror(ret, &match_reg, reg_err, sizeof(reg_err));
error("regex compilation failed: %s", reg_err);
goto out;
}
mreg = &match_reg;
}
if (dry_run)
printf("This is a dry-run, no files are going to be restored\n");
ret = search_dir(root, &key, dir_name, "", mreg);
out:
if (mreg)
regfree(mreg);
close_ctree(root);
return !!ret;
}
DEFINE_SIMPLE_COMMAND(restore, "restore");
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