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_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;
}