#include <sys/param.h>
#include <sys/stat.h>
#include <sys/disk.h>
#include <sys/disklabel.h>
#include <sys/ioctl.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <err.h>
#include <errno.h>
#include <stdbool.h>
static bool secure = false;
static bool zeroout = false;
static char *zeros = NULL;
static unsigned ttywidth = 80;
#define FDISCARD_VERSION 20240113u
static void __dead
usage(const char* msg)
{
FILE *out = stdout;
int rv = 0;
if (msg) {
out = stderr;
rv = 1;
fprintf(out, "%s", msg);
}
fprintf(out, "Usage: blkdiscard [-hnRsVvz] [-l length] "
"[-m chunk_bytes]\n"
" [-o first_byte] <file>\n");
exit(rv);
}
static void __dead
version(void)
{
printf("NetBSD blkdiscard %u\n", FDISCARD_VERSION);
exit(0);
}
static void
write_one(int fd, off_t discard_size, off_t first_byte)
{
if (secure)
;
else if (zeroout) {
if (pwrite(fd, zeros, discard_size, first_byte) != discard_size)
err(1, "pwrite");
} else if (fdiscard(fd, first_byte, discard_size) != 0)
err(1, "fdiscard");
}
int
main(int argc, char *argv[])
{
off_t first_byte = 0, end_offset = 0;
off_t max_per_call = 32 * 1024 * 1024;
off_t discard_size;
off_t size = 0;
off_t length = 0;
int64_t val;
int i;
bool verbose = false;
struct stat sb;
bool norun = strcmp(getprogname(), "blkdiscard") != 0;
while ((i = getopt(argc, argv, "f:hl:m:no:p:RsvVz")) != -1) {
switch (i) {
case 'l':
if (dehumanize_number(optarg, &val) == -1 || val < 0)
usage("bad -s\n");
length = val;
break;
case 'm':
case 'p':
if (dehumanize_number(optarg, &val) == -1 || val < 0)
usage("bad -m\n");
max_per_call = val;
break;
case 'f':
case 'o':
if (dehumanize_number(optarg, &val) == -1 || val < 0)
usage("bad -f\n");
first_byte = val;
break;
case 'n':
norun = true;
break;
case 'R':
norun = false;
break;
case 's':
secure = true;
break;
case 'V':
version();
case 'v':
verbose = true;
break;
case 'z':
zeroout = true;
break;
case 'h':
usage(NULL);
default:
usage("bad options\n");
}
}
argc -= optind;
argv += optind;
if (secure)
usage("blkdiscard: secure erase not yet implemented\n");
if (zeroout) {
zeros = calloc(1, max_per_call);
if (!zeros)
errx(1, "Unable to allocate %lld bytes for zeros",
(long long)max_per_call);
}
if (length)
end_offset = first_byte + length;
if (argc != 1)
usage("not one arg left\n");
char *name = argv[0];
int fd = open(name, O_RDWR);
if (fd < 0)
err(1, "open on %s", name);
if (size == 0) {
struct dkwedge_info dkw;
if (ioctl(fd, DIOCGWEDGEINFO, &dkw) == 0) {
size = dkw.dkw_size * DEV_BSIZE;
if (verbose)
printf("%s: wedge size is %lld\n", name,
(long long)size);
}
}
if (size == 0 && fstat(fd, &sb) != -1) {
struct disklabel dl;
if (ioctl(fd, DIOCGDINFO, &dl) != -1) {
unsigned part = DISKPART(sb.st_rdev);
size = (uint64_t)dl.d_partitions[part].p_size *
dl.d_secsize;
if (verbose)
printf("%s: partition %u disklabel size is"
" %lld\n", name, part, (long long)size);
}
if (size == 0) {
size = sb.st_size;
if (verbose)
printf("%s: stat size is %lld\n", name,
(long long)size);
}
}
if (size == 0) {
fprintf(stderr, "unable to determine size.\n");
exit(1);
}
size -= first_byte;
if (end_offset) {
if (end_offset > size) {
fprintf(stderr, "end_offset %lld > size %lld\n",
(long long)end_offset, (long long)size);
usage("");
}
size = end_offset;
}
if (verbose) {
struct winsize winsize;
printf("%sgoing to %s on %s from byte %lld for "
"%lld bytes, %lld at a time\n",
norun ? "not " : "",
secure ? "secure erase" :
zeroout ? "zero out" : "fdiscard(2)",
name, (long long)first_byte, (long long)size,
(long long)max_per_call);
if (ioctl(fileno(stdout), TIOCGWINSZ, &winsize) != -1 &&
winsize.ws_col > 1)
ttywidth = winsize.ws_col - 1;
}
unsigned loop = 0;
while (size > 0) {
if (size > max_per_call)
discard_size = max_per_call;
else
discard_size = size;
if (!norun)
write_one(fd, discard_size, first_byte);
first_byte += discard_size;
size -= discard_size;
if (verbose) {
printf(".");
fflush(stdout);
if (++loop >= ttywidth) {
loop = 0;
printf("\n");
}
}
}
if (loop != 0)
printf("\n");
if (close(fd) != 0)
warnx("close failed: %s", strerror(errno));
return 0;
}
