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libiscsi/utils/iscsi-discard.c
Duncan Overbruck 2e4231d1d8 use PRIu64 printf format for uint64_t
2026-02-04 20:12:19 +01:00

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/*
Copyright (C) 2023 by zhenwei pi <pizhenwei@bytedance.com>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
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, see <http://www.gnu.org/licenses/>.
*/
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <inttypes.h>
#include <string.h>
#include <poll.h>
#include <getopt.h>
#include "iscsi.h"
#include "scsi-lowlevel.h"
#define MIN(a, b) (((a) < (b)) ? (a) : (b))
const char *initiator = "iqn.2007-10.com.github:sahlberg:libiscsi:iscsi-discard";
/* query unmap/write zero max blocks */
static uint64_t inquiry_max_blocks(struct iscsi_context *iscsi, int lun, int zeroout)
{
struct scsi_task *task;
int full_size;
struct scsi_inquiry_block_limits *inq;
uint64_t max_blocks = 0;
/* See how big this inquiry data is */
task = iscsi_inquiry_sync(iscsi, lun, 1, SCSI_INQUIRY_PAGECODE_BLOCK_LIMITS, 64);
if (task == NULL || task->status != SCSI_STATUS_GOOD) {
fprintf(stderr, "Inquiry command failed : %s\n", iscsi_get_error(iscsi));
exit(EIO);
}
full_size = scsi_datain_getfullsize(task);
if (full_size > task->datain.size) {
scsi_free_scsi_task(task);
/* we need more data for the full list */
if ((task = iscsi_inquiry_sync(iscsi, lun, 1, SCSI_INQUIRY_PAGECODE_BLOCK_LIMITS, full_size)) == NULL) {
fprintf(stderr, "Inquiry command failed : %s\n", iscsi_get_error(iscsi));
exit(EIO);
}
}
inq = scsi_datain_unmarshall(task);
if (inq == NULL) {
fprintf(stderr, "failed to unmarshall inquiry datain blob\n");
exit(EIO);
}
if (zeroout) {
/* A MAXIMUM WRITE SAME LENGTH field set to zero indicates
that the device server does not report a limit on the number
of logical blocks that may be requested for a single
WRITE SAME command */
max_blocks = inq->max_ws_len;
if (!max_blocks)
max_blocks = (uint64_t)-1ULL;
} else {
/* A MAXIMUM UNMAP LBA COUNT field set to 0000_0000h indicates
that the device server does not implement the UNMAP command */
max_blocks = inq->max_unmap;
}
scsi_free_scsi_task(task);
return max_blocks;
}
void print_help(void)
{
fprintf(stderr, "Usage: iscsi_readcapacity16 [OPTION...] <iscsi-url>\n");
fprintf(stderr, " -i, --initiator-name=iqn-name Initiatorname to use\n");
fprintf(stderr, " -o, --offset "
"Byte offset into the target from which to start discarding. "
"The provided value must be aligned to the target sector size. "
"The default value is zero.\n");
fprintf(stderr, " -l, --length "
"The number of bytes to discard (counting from the starting point). "
"The provided value must be aligned to the target sector size. "
"If the specified value extends past the end of the device, "
"iscsi-discard will stop at the device size boundary. "
"The default value extends to the end of the device.\n");
fprintf(stderr, " -z, --zeroout "
"Zero-fill rather than discard.\n");
fprintf(stderr, " -d, --debug=integer debug level (0=disabled)\n");
fprintf(stderr, "\n");
fprintf(stderr, "Help options:\n");
fprintf(stderr, " -?, --help Show this help message\n");
fprintf(stderr, "\n");
fprintf(stderr, "iSCSI URL format : %s\n", ISCSI_URL_SYNTAX);
fprintf(stderr, "\n");
fprintf(stderr, "<host> is either of:\n");
fprintf(stderr, " \"hostname\" iscsi.example\n");
fprintf(stderr, " \"ipv4-address\" 10.1.1.27\n");
fprintf(stderr, " \"ipv6-address\" [fce0::1]\n");
exit(0);
}
int main(int argc, char *argv[])
{
struct iscsi_context *iscsi;
char *url = NULL;
struct iscsi_url *iscsi_url = NULL;
int debug = 0, zeroout = 0;
int option_index, c;
unsigned int block_length;
uint64_t offset = 0, length = 0, capacity, lba, blocks, max_blocks;
struct scsi_task *task;
struct scsi_readcapacity16 *rc16;
int ret = EINVAL;
static struct option long_options[] = {
{"offset", required_argument, NULL, 'o'},
{"length", required_argument, NULL, 'l'},
{"zeroout", no_argument, NULL, 'z'},
{"debug", required_argument, NULL, 'd'},
{"help", no_argument, NULL, 'h'},
{"initiator-name", required_argument, NULL, 'i'},
{0, 0, 0, 0}
};
while ((c = getopt_long(argc, argv, "o:l:zd:i:h?", long_options,
&option_index)) != -1) {
switch (c) {
case 'o':
offset = strtoll(optarg, NULL, 0);
break;
case 'l':
length = strtoll(optarg, NULL, 0);
break;
case 'z':
zeroout = 1;
break;
case 'd':
debug = strtol(optarg, NULL, 0);
break;
case 'i':
initiator = optarg;
break;
case 'h':
case '?':
print_help();
break;
default:
fprintf(stderr, "Unrecognized option '%c'\n\n", c);
print_help();
break;
}
}
iscsi = iscsi_create_context(initiator);
if (iscsi == NULL) {
fprintf(stderr, "Failed to create context\n");
exit(EINVAL);
}
if (debug > 0) {
iscsi_set_log_fn(iscsi, iscsi_log_to_stderr);
iscsi_set_log_level(iscsi, debug);
}
if (argv[optind] != NULL) {
url = strdup(argv[optind]);
}
if (url == NULL) {
fprintf(stderr, "You must specify the URL\n");
print_help();
}
iscsi_url = iscsi_parse_full_url(iscsi, url);
free(url);
if (iscsi_url == NULL) {
fprintf(stderr, "Failed to parse URL: %s\n",
iscsi_get_error(iscsi));
exit(EINVAL);
}
iscsi_set_session_type(iscsi, ISCSI_SESSION_NORMAL);
iscsi_set_header_digest(iscsi, ISCSI_HEADER_DIGEST_NONE_CRC32C);
if (iscsi_full_connect_sync(iscsi, iscsi_url->portal, iscsi_url->lun) != 0) {
fprintf(stderr, "Login Failed. %s\n", iscsi_get_error(iscsi));
goto out;
}
task = iscsi_readcapacity16_sync(iscsi, iscsi_url->lun);
if (task == NULL || task->status != SCSI_STATUS_GOOD) {
fprintf(stderr,"Failed to send readcapacity command\n");
goto out;
}
rc16 = scsi_datain_unmarshall(task);
if (rc16 == NULL) {
fprintf(stderr,"Failed to unmarshall readcapacity16 data\n");
goto out;
}
block_length = rc16->block_length;
if (offset & (block_length - 1)) {
fprintf(stderr,"Unaligned offset of %u\n", block_length);
goto free_task;
}
capacity = block_length * (rc16->returned_lba + 1);
if (offset > capacity) {
fprintf(stderr,"Offset(%" PRIu64 ") exceeds capacity(%" PRIu64 ")\n", offset, capacity);
goto free_task;
}
if (!length || (offset + length > capacity)) {
length = block_length * (rc16->returned_lba + 1) - offset;
}
/* free readcapacity16 task */
scsi_free_scsi_task(task);
max_blocks = inquiry_max_blocks(iscsi, iscsi_url->lun, zeroout);
if (!max_blocks) {
fprintf(stderr, "Operation not supported\n");
exit(EOPNOTSUPP);
}
lba = offset / block_length;
blocks = length / block_length;
for (uint64_t endlba = lba + blocks; lba < endlba; ) {
uint64_t towrite = MIN(max_blocks, endlba - lba);
if (zeroout) {
static void *zerobuf;
if (!zerobuf) {
zerobuf = calloc(block_length, 1);
assert(zerobuf);
}
task = iscsi_writesame16_sync(iscsi, iscsi_url->lun, lba, zerobuf,
block_length, towrite, 0, 0, 0, 0);
if (task == NULL || task->status != SCSI_STATUS_GOOD) {
fprintf(stderr,"Failed to execute writesame16 command\n");
goto out;
}
} else {
struct unmap_list list;
list.lba = lba;
list.num = towrite;
task = iscsi_unmap_sync(iscsi, iscsi_url->lun, 0, 0, &list, 1);
if (task == NULL || task->status != SCSI_STATUS_GOOD) {
fprintf(stderr,"Failed to execute unmap command\n");
goto out;
}
}
lba += towrite;
scsi_free_scsi_task(task);
}
ret = 0;
goto out;
free_task:
scsi_free_scsi_task(task);
out:
iscsi_destroy_url(iscsi_url);
iscsi_logout_sync(iscsi);
iscsi_destroy_context(iscsi);
return ret;
}
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