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mkfs: Zero 2MB at the start and end of the device 

But, on sparc, don't zero the first 1k.
Chris Mason 2008-02-15 11:19:26 -05:00 committed by David Woodhouse
parent d284c1d890
commit 0c6513b1d1
1 changed files with 51 additions and 6 deletions
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57
mkfs.c
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@ -67,6 +67,43 @@ static u64 parse_size(char *s)
return atol(s) * mult;
}
static int zero_blocks(int fd, off_t start, size_t len)
{
char *buf = malloc(len);
int ret = 0;
ssize_t written;
if (!buf)
return -ENOMEM;
memset(buf, 0, len);
written = pwrite(fd, buf, len, start);
if (written != len)
ret = -EIO;
free(buf);
return ret;
}
static int zero_dev_start(int fd)
{
off_t start = 0;
size_t len = 2 * 1024 * 1024;
#ifdef __sparc__
/* don't overwrite the disk labels on sparc */
start = 1024;
len -= 1024;
#endif
return zero_blocks(fd, start, len);
}
static int zero_dev_end(int fd, u64 dev_size)
{
size_t len = 2 * 1024 * 1024;
off_t start = dev_size - len;
return zero_blocks(fd, start, len);
}
static int make_root_dir(int fd) {
struct btrfs_root *root;
struct btrfs_trans_handle *trans;
@ -143,7 +180,7 @@ int main(int ac, char **av)
u32 nodesize = 16 * 1024;
u32 stripesize = 4096;
u64 blocks[4];
char *buf = malloc(sectorsize);
int zero_end = 0;
while(1) {
int c;
@ -201,6 +238,7 @@ int main(int ac, char **av)
fprintf(stderr, "unable to find %s size\n", file);
exit(1);
}
zero_end = 1;
}
block_count /= sectorsize;
block_count *= sectorsize;
@ -209,16 +247,23 @@ int main(int ac, char **av)
fprintf(stderr, "device %s is too small\n", file);
exit(1);
}
memset(buf, 0, sectorsize);
for(i = 0; i < 64; i++) {
ret = write(fd, buf, sectorsize);
if (ret != sectorsize) {
fprintf(stderr, "unable to zero fill device\n");
ret = zero_dev_start(fd);
if (ret) {
fprintf(stderr, "failed to zero device start %d\n", ret);
exit(1);
}
if (zero_end) {
ret = zero_dev_end(fd, block_count);
if (ret) {
fprintf(stderr, "failed to zero device end %d\n", ret);
exit(1);
}
}
for (i = 0; i < 4; i++)
blocks[i] = BTRFS_SUPER_INFO_OFFSET + leafsize * i;
ret = make_btrfs(fd, blocks, block_count, nodesize, leafsize,
sectorsize, stripesize);
if (ret) {