int btrfs_prepare_device(int fd, char *file, int zero_end, u64 *block_count_ret,
u64 max_block_count, int *mixed, int nodiscard)
{
u64 block_count;
u64 bytenr;
struct stat st;
int i, ret;
ret = fstat(fd, &st);
if (ret < 0) {
fprintf(stderr, "unable to stat %s\n", file);
exit(1);
}
block_count = btrfs_device_size(fd, &st);
if (block_count == 0) {
fprintf(stderr, "unable to find %s size\n", file);
exit(1);
}
if (max_block_count)
block_count = min(block_count, max_block_count);
zero_end = 1;
if (block_count < 1024 * 1024 * 1024 && !(*mixed)) {
printf("SMALL VOLUME: forcing mixed metadata/data groups\n");
*mixed = 1;
}
if (!nodiscard) {
/*
* We intentionally ignore errors from the discard ioctl. It is
* not necessary for the mkfs functionality but just an optimization.
*/
discard_blocks(fd, 0, block_count);
}
ret = zero_dev_start(fd);
if (ret) {
fprintf(stderr, "failed to zero device start %d\n", ret);
exit(1);
}
for (i = 0 ; i < BTRFS_SUPER_MIRROR_MAX; i++) {
bytenr = btrfs_sb_offset(i);
if (bytenr >= block_count)
break;
zero_blocks(fd, bytenr, BTRFS_SUPER_INFO_SIZE);
}
if (zero_end) {
ret = zero_dev_end(fd, block_count);
if (ret) {
fprintf(stderr, "failed to zero device end %d\n", ret);
exit(1);
}
}
*block_count_ret = block_count;
return 0;
}
int btrfs_read_dev_super(int fd, struct btrfs_super_block *sb, u64 sb_bytenr)
{
u8 fsid[BTRFS_FSID_SIZE];
int fsid_is_initialized = 0;
struct btrfs_super_block buf;
int i;
int ret;
u64 transid = 0;
u64 bytenr;
if (sb_bytenr != BTRFS_SUPER_INFO_OFFSET) {
ret = pread64(fd, &buf, sizeof(buf), sb_bytenr);
if (ret < sizeof(buf))
return -1;
if (btrfs_super_bytenr(&buf) != sb_bytenr ||
buf.magic != cpu_to_le64(BTRFS_MAGIC))
return -1;
memcpy(sb, &buf, sizeof(*sb));
return 0;
}
for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
bytenr = btrfs_sb_offset(i);
ret = pread64(fd, &buf, sizeof(buf), bytenr);
if (ret < sizeof(buf))
break;
if (btrfs_super_bytenr(&buf) != bytenr )
continue;
/* if magic is NULL, the device was removed */
if (buf.magic == 0 && i == 0)
return -1;
if (buf.magic != cpu_to_le64(BTRFS_MAGIC))
continue;
if (!fsid_is_initialized) {
memcpy(fsid, buf.fsid, sizeof(fsid));
fsid_is_initialized = 1;
} else if (memcmp(fsid, buf.fsid, sizeof(fsid))) {
/*
* the superblocks (the original one and
* its backups) contain data of different
* filesystems -> the super cannot be trusted
*/
continue;
}
if (btrfs_super_generation(&buf) > transid) {
memcpy(sb, &buf, sizeof(*sb));
transid = btrfs_super_generation(&buf);
}
}
return transid > 0 ? 0 : -1;
}
int write_dev_supers(struct btrfs_root *root, struct btrfs_super_block *sb,
struct btrfs_device *device)
{
u64 bytenr;
u32 crc;
int i, ret;
if (root->fs_info->super_bytenr != BTRFS_SUPER_INFO_OFFSET) {
btrfs_set_super_bytenr(sb, root->fs_info->super_bytenr);
crc = ~(u32)0;
crc = btrfs_csum_data(NULL, (char *)sb + BTRFS_CSUM_SIZE, crc,
BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
btrfs_csum_final(crc, (char *)&sb->csum[0]);
/*
* super_copy is BTRFS_SUPER_INFO_SIZE bytes and is
* zero filled, we can use it directly
*/
ret = pwrite64(device->fd, root->fs_info->super_copy,
BTRFS_SUPER_INFO_SIZE,
root->fs_info->super_bytenr);
BUG_ON(ret != BTRFS_SUPER_INFO_SIZE);
return 0;
}
for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
bytenr = btrfs_sb_offset(i);
if (bytenr + BTRFS_SUPER_INFO_SIZE > device->total_bytes)
break;
btrfs_set_super_bytenr(sb, bytenr);
crc = ~(u32)0;
crc = btrfs_csum_data(NULL, (char *)sb + BTRFS_CSUM_SIZE, crc,
BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
btrfs_csum_final(crc, (char *)&sb->csum[0]);
/*
* super_copy is BTRFS_SUPER_INFO_SIZE bytes and is
* zero filled, we can use it directly
*/
ret = pwrite64(device->fd, root->fs_info->super_copy,
BTRFS_SUPER_INFO_SIZE, bytenr);
BUG_ON(ret != BTRFS_SUPER_INFO_SIZE);
}
return 0;
}
int btrfs_prepare_device(int fd, char *file, int zero_end, u64 *block_count_ret)
{
u64 block_count;
u64 bytenr;
struct stat st;
int i, ret;
ret = fstat(fd, &st);
if (ret < 0) {
fprintf(stderr, "unable to stat %s\n", file);
exit(1);
}
block_count = device_size(fd, &st);
if (block_count == 0) {
fprintf(stderr, "unable to find %s size\n", file);
exit(1);
}
zero_end = 1;
if (block_count < 256 * 1024 * 1024) {
fprintf(stderr, "device %s is too small "
"(must be at least 256 MB)\n", file);
exit(1);
}
ret = zero_dev_start(fd);
if (ret) {
fprintf(stderr, "failed to zero device start %d\n", ret);
exit(1);
}
for (i = 0 ; i < BTRFS_SUPER_MIRROR_MAX; i++) {
bytenr = btrfs_sb_offset(i);
if (bytenr >= block_count)
break;
zero_blocks(fd, bytenr, BTRFS_SUPER_INFO_SIZE);
}
if (zero_end) {
ret = zero_dev_end(fd, block_count);
if (ret) {
fprintf(stderr, "failed to zero device end %d\n", ret);
exit(1);
}
}
*block_count_ret = block_count;
return 0;
}
static int hole_includes_sb_mirror(const u64 start, const u64 end)
{
int i;
int ret = 0;
for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
u64 bytenr = btrfs_sb_offset(i);
if (bytenr >= start && bytenr <= end) {
ret = 1;
break;
}
}
return ret;
}
int btrfs_read_dev_super(int fd, struct btrfs_super_block *sb, u64 sb_bytenr)
{
u8 fsid[BTRFS_FSID_SIZE];
struct btrfs_super_block buf;
int i;
int ret;
u64 transid = 0;
u64 bytenr;
if (sb_bytenr != BTRFS_SUPER_INFO_OFFSET) {
ret = pread64(fd, &buf, sizeof(buf), sb_bytenr);
if (ret < sizeof(buf))
return -1;
if (btrfs_super_bytenr(&buf) != sb_bytenr ||
strncmp((char *)(&buf.magic), BTRFS_MAGIC,
sizeof(buf.magic)))
return -1;
memcpy(sb, &buf, sizeof(*sb));
return 0;
}
for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
bytenr = btrfs_sb_offset(i);
ret = pread64(fd, &buf, sizeof(buf), bytenr);
if (ret < sizeof(buf))
break;
if (btrfs_super_bytenr(&buf) != bytenr ||
strncmp((char *)(&buf.magic), BTRFS_MAGIC,
sizeof(buf.magic)))
continue;
if (i == 0)
memcpy(fsid, buf.fsid, sizeof(fsid));
else if (memcmp(fsid, buf.fsid, sizeof(fsid)))
continue;
if (btrfs_super_generation(&buf) > transid) {
memcpy(sb, &buf, sizeof(*sb));
transid = btrfs_super_generation(&buf);
}
}
return transid > 0 ? 0 : -1;
}
int main(int argc, char **argv)
{
int opt;
int all = 0;
int full = 0;
int force = 0;
char *filename;
int fd = -1;
int i;
u64 arg;
u64 sb_bytenr = btrfs_sb_offset(0);
while ((opt = getopt(argc, argv, "fFai:s:")) != -1) {
switch (opt) {
case 'i':
arg = arg_strtou64(optarg);
if (arg >= BTRFS_SUPER_MIRROR_MAX) {
fprintf(stderr,
"Illegal super_mirror %llu\n",
arg);
print_usage();
exit(1);
}
sb_bytenr = btrfs_sb_offset(arg);
break;
case 'a':
all = 1;
break;
case 'f':
full = 1;
break;
case 'F':
force = 1;
break;
case 's':
sb_bytenr = arg_strtou64(optarg);
all = 0;
break;
default:
print_usage();
exit(1);
}
}
set_argv0(argv);
if (check_argc_min(argc - optind, 1)) {
print_usage();
exit(1);
}
for (i = optind; i < argc; i++) {
filename = argv[i];
fd = open(filename, O_RDONLY, 0666);
if (fd < 0) {
fprintf(stderr, "Could not open %s\n", filename);
exit(1);
}
if (all) {
int idx;
for (idx = 0; idx < BTRFS_SUPER_MIRROR_MAX; idx++) {
sb_bytenr = btrfs_sb_offset(idx);
if (load_and_dump_sb(filename, fd,
sb_bytenr, full, force)) {
close(fd);
exit(1);
}
putchar('\n');
}
} else {
load_and_dump_sb(filename, fd, sb_bytenr, full, force);
putchar('\n');
}
close(fd);
}
exit(0);
}
int cmd_inspect_dump_super(int argc, char **argv)
{
int all = 0;
int full = 0;
int force = 0;
char *filename;
int fd = -1;
int i;
int ret = 0;
u64 arg;
u64 sb_bytenr = btrfs_sb_offset(0);
while (1) {
int c;
enum { GETOPT_VAL_BYTENR = 257 };
static const struct option long_options[] = {
{"all", no_argument, NULL, 'a'},
{"bytenr", required_argument, NULL, GETOPT_VAL_BYTENR },
{"full", no_argument, NULL, 'f'},
{"force", no_argument, NULL, 'F'},
{"super", required_argument, NULL, 's' },
{NULL, 0, NULL, 0}
};
c = getopt_long(argc, argv, "fFai:s:", long_options, NULL);
if (c < 0)
break;
switch (c) {
case 'i':
warning(
"option -i is deprecated, please use -s or --super");
arg = arg_strtou64(optarg);
if (arg >= BTRFS_SUPER_MIRROR_MAX) {
error("super mirror too big: %llu >= %d",
arg, BTRFS_SUPER_MIRROR_MAX);
return 1;
}
sb_bytenr = btrfs_sb_offset(arg);
break;
case 'a':
all = 1;
break;
case 'f':
full = 1;
break;
case 'F':
force = 1;
break;
case 's':
arg = arg_strtou64(optarg);
if (BTRFS_SUPER_MIRROR_MAX <= arg) {
warning(
"deprecated use of -s <bytenr> with %llu, assuming --bytenr",
(unsigned long long)arg);
sb_bytenr = arg;
} else {
sb_bytenr = btrfs_sb_offset(arg);
}
all = 0;
break;
case GETOPT_VAL_BYTENR:
arg = arg_strtou64(optarg);
sb_bytenr = arg;
all = 0;
break;
default:
usage_unknown_option(cmd_inspect_dump_super_usage, argv);
}
}
if (check_argc_min(argc - optind, 1))
return 1;
for (i = optind; i < argc; i++) {
filename = argv[i];
fd = open(filename, O_RDONLY);
if (fd < 0) {
error("cannot open %s: %m", filename);
ret = 1;
goto out;
}
if (all) {
int idx;
for (idx = 0; idx < BTRFS_SUPER_MIRROR_MAX; idx++) {
sb_bytenr = btrfs_sb_offset(idx);
if (load_and_dump_sb(filename, fd,
sb_bytenr, full, force)) {
close(fd);
ret = 1;
goto out;
}
putchar('\n');
}
} else {
load_and_dump_sb(filename, fd, sb_bytenr, full, force);
putchar('\n');
}
close(fd);
}
out:
return ret;
}
int main(int ac, char **av)
{
struct btrfs_root *root;
int ret;
u64 num = 0;
u64 bytenr = 0;
while(1) {
int c;
c = getopt(ac, av, "s:");
if (c < 0)
break;
switch(c) {
case 's':
num = arg_strtou64(optarg);
if (num >= BTRFS_SUPER_MIRROR_MAX) {
fprintf(stderr,
"ERROR: super mirror should be less than: %d\n",
BTRFS_SUPER_MIRROR_MAX);
exit(1);
}
bytenr = btrfs_sb_offset(((int)num));
break;
default:
print_usage();
}
}
set_argv0(av);
ac = ac - optind;
if (check_argc_exact(ac, 1))
print_usage();
if (bytenr == 0) {
fprintf(stderr, "Please select the super copy with -s\n");
print_usage();
}
radix_tree_init();
if((ret = check_mounted(av[optind])) < 0) {
fprintf(stderr, "Could not check mount status: %s\n", strerror(-ret));
return ret;
} else if(ret) {
fprintf(stderr, "%s is currently mounted. Aborting.\n", av[optind]);
return -EBUSY;
}
root = open_ctree(av[optind], bytenr, 1);
if (!root) {
fprintf(stderr, "Open ctree failed\n");
return 1;
}
/* make the super writing code think we've read the first super */
root->fs_info->super_bytenr = BTRFS_SUPER_INFO_OFFSET;
ret = write_all_supers(root);
/* we don't close the ctree or anything, because we don't want a real
* transaction commit. We just want the super copy we pulled off the
* disk to overwrite all the other copies
*/
printf("using SB copy %llu, bytenr %llu\n", (unsigned long long)num,
(unsigned long long)bytenr);
close_ctree(root);
btrfs_close_all_devices();
return ret;
}
