linux-user: fixed s390x clone() argument order
[qemu/ar7.git] / block / iscsi.c
blobc0ea0c45439dc5eb590af938079d71060ec42c62
1 /*
2 * QEMU Block driver for iSCSI images
4 * Copyright (c) 2010-2011 Ronnie Sahlberg <ronniesahlberg@gmail.com>
5 * Copyright (c) 2012-2013 Peter Lieven <pl@kamp.de>
7 * Permission is hereby granted, free of charge, to any person obtaining a copy
8 * of this software and associated documentation files (the "Software"), to deal
9 * in the Software without restriction, including without limitation the rights
10 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
11 * copies of the Software, and to permit persons to whom the Software is
12 * furnished to do so, subject to the following conditions:
14 * The above copyright notice and this permission notice shall be included in
15 * all copies or substantial portions of the Software.
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
20 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
22 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
23 * THE SOFTWARE.
26 #include "config-host.h"
28 #include <poll.h>
29 #include <arpa/inet.h>
30 #include "qemu-common.h"
31 #include "qemu/config-file.h"
32 #include "qemu/error-report.h"
33 #include "block/block_int.h"
34 #include "trace.h"
35 #include "block/scsi.h"
36 #include "qemu/iov.h"
37 #include "sysemu/sysemu.h"
38 #include "qmp-commands.h"
40 #include <iscsi/iscsi.h>
41 #include <iscsi/scsi-lowlevel.h>
43 #ifdef __linux__
44 #include <scsi/sg.h>
45 #include <block/scsi.h>
46 #endif
48 typedef struct IscsiLun {
49 struct iscsi_context *iscsi;
50 int lun;
51 enum scsi_inquiry_peripheral_device_type type;
52 int block_size;
53 uint64_t num_blocks;
54 int events;
55 QEMUTimer *nop_timer;
56 uint8_t lbpme;
57 uint8_t lbprz;
58 uint8_t has_write_same;
59 struct scsi_inquiry_logical_block_provisioning lbp;
60 struct scsi_inquiry_block_limits bl;
61 unsigned char *zeroblock;
62 } IscsiLun;
64 typedef struct IscsiTask {
65 int status;
66 int complete;
67 int retries;
68 int do_retry;
69 struct scsi_task *task;
70 Coroutine *co;
71 QEMUBH *bh;
72 } IscsiTask;
74 typedef struct IscsiAIOCB {
75 BlockDriverAIOCB common;
76 QEMUIOVector *qiov;
77 QEMUBH *bh;
78 IscsiLun *iscsilun;
79 struct scsi_task *task;
80 uint8_t *buf;
81 int status;
82 int canceled;
83 int retries;
84 int64_t sector_num;
85 int nb_sectors;
86 #ifdef __linux__
87 sg_io_hdr_t *ioh;
88 #endif
89 } IscsiAIOCB;
91 #define NOP_INTERVAL 5000
92 #define MAX_NOP_FAILURES 3
93 #define ISCSI_CMD_RETRIES 5
95 static void
96 iscsi_bh_cb(void *p)
98 IscsiAIOCB *acb = p;
100 qemu_bh_delete(acb->bh);
102 g_free(acb->buf);
103 acb->buf = NULL;
105 if (acb->canceled == 0) {
106 acb->common.cb(acb->common.opaque, acb->status);
109 if (acb->task != NULL) {
110 scsi_free_scsi_task(acb->task);
111 acb->task = NULL;
114 qemu_aio_release(acb);
117 static void
118 iscsi_schedule_bh(IscsiAIOCB *acb)
120 if (acb->bh) {
121 return;
123 acb->bh = qemu_bh_new(iscsi_bh_cb, acb);
124 qemu_bh_schedule(acb->bh);
127 static void iscsi_co_generic_bh_cb(void *opaque)
129 struct IscsiTask *iTask = opaque;
130 qemu_bh_delete(iTask->bh);
131 qemu_coroutine_enter(iTask->co, NULL);
134 static void
135 iscsi_co_generic_cb(struct iscsi_context *iscsi, int status,
136 void *command_data, void *opaque)
138 struct IscsiTask *iTask = opaque;
139 struct scsi_task *task = command_data;
141 iTask->complete = 1;
142 iTask->status = status;
143 iTask->do_retry = 0;
144 iTask->task = task;
146 if (iTask->retries-- > 0 && status == SCSI_STATUS_CHECK_CONDITION
147 && task->sense.key == SCSI_SENSE_UNIT_ATTENTION) {
148 iTask->do_retry = 1;
149 goto out;
152 if (status != SCSI_STATUS_GOOD) {
153 error_report("iSCSI: Failure. %s", iscsi_get_error(iscsi));
156 out:
157 if (iTask->co) {
158 iTask->bh = qemu_bh_new(iscsi_co_generic_bh_cb, iTask);
159 qemu_bh_schedule(iTask->bh);
163 static void iscsi_co_init_iscsitask(IscsiLun *iscsilun, struct IscsiTask *iTask)
165 *iTask = (struct IscsiTask) {
166 .co = qemu_coroutine_self(),
167 .retries = ISCSI_CMD_RETRIES,
171 static void
172 iscsi_abort_task_cb(struct iscsi_context *iscsi, int status, void *command_data,
173 void *private_data)
175 IscsiAIOCB *acb = private_data;
177 acb->status = -ECANCELED;
178 iscsi_schedule_bh(acb);
181 static void
182 iscsi_aio_cancel(BlockDriverAIOCB *blockacb)
184 IscsiAIOCB *acb = (IscsiAIOCB *)blockacb;
185 IscsiLun *iscsilun = acb->iscsilun;
187 if (acb->status != -EINPROGRESS) {
188 return;
191 acb->canceled = 1;
193 /* send a task mgmt call to the target to cancel the task on the target */
194 iscsi_task_mgmt_abort_task_async(iscsilun->iscsi, acb->task,
195 iscsi_abort_task_cb, acb);
197 while (acb->status == -EINPROGRESS) {
198 qemu_aio_wait();
202 static const AIOCBInfo iscsi_aiocb_info = {
203 .aiocb_size = sizeof(IscsiAIOCB),
204 .cancel = iscsi_aio_cancel,
208 static void iscsi_process_read(void *arg);
209 static void iscsi_process_write(void *arg);
211 static void
212 iscsi_set_events(IscsiLun *iscsilun)
214 struct iscsi_context *iscsi = iscsilun->iscsi;
215 int ev;
217 /* We always register a read handler. */
218 ev = POLLIN;
219 ev |= iscsi_which_events(iscsi);
220 if (ev != iscsilun->events) {
221 qemu_aio_set_fd_handler(iscsi_get_fd(iscsi),
222 iscsi_process_read,
223 (ev & POLLOUT) ? iscsi_process_write : NULL,
224 iscsilun);
228 iscsilun->events = ev;
231 static void
232 iscsi_process_read(void *arg)
234 IscsiLun *iscsilun = arg;
235 struct iscsi_context *iscsi = iscsilun->iscsi;
237 iscsi_service(iscsi, POLLIN);
238 iscsi_set_events(iscsilun);
241 static void
242 iscsi_process_write(void *arg)
244 IscsiLun *iscsilun = arg;
245 struct iscsi_context *iscsi = iscsilun->iscsi;
247 iscsi_service(iscsi, POLLOUT);
248 iscsi_set_events(iscsilun);
251 static int64_t sector_lun2qemu(int64_t sector, IscsiLun *iscsilun)
253 return sector * iscsilun->block_size / BDRV_SECTOR_SIZE;
256 static int64_t sector_qemu2lun(int64_t sector, IscsiLun *iscsilun)
258 return sector * BDRV_SECTOR_SIZE / iscsilun->block_size;
261 static bool is_request_lun_aligned(int64_t sector_num, int nb_sectors,
262 IscsiLun *iscsilun)
264 if ((sector_num * BDRV_SECTOR_SIZE) % iscsilun->block_size ||
265 (nb_sectors * BDRV_SECTOR_SIZE) % iscsilun->block_size) {
266 error_report("iSCSI misaligned request: "
267 "iscsilun->block_size %u, sector_num %" PRIi64
268 ", nb_sectors %d",
269 iscsilun->block_size, sector_num, nb_sectors);
270 return 0;
272 return 1;
275 static int coroutine_fn iscsi_co_writev(BlockDriverState *bs,
276 int64_t sector_num, int nb_sectors,
277 QEMUIOVector *iov)
279 IscsiLun *iscsilun = bs->opaque;
280 struct IscsiTask iTask;
281 uint64_t lba;
282 uint32_t num_sectors;
283 uint8_t *data = NULL;
284 uint8_t *buf = NULL;
286 if (!is_request_lun_aligned(sector_num, nb_sectors, iscsilun)) {
287 return -EINVAL;
290 lba = sector_qemu2lun(sector_num, iscsilun);
291 num_sectors = sector_qemu2lun(nb_sectors, iscsilun);
292 #if !defined(LIBISCSI_FEATURE_IOVECTOR)
293 /* if the iovec only contains one buffer we can pass it directly */
294 if (iov->niov == 1) {
295 data = iov->iov[0].iov_base;
296 } else {
297 size_t size = MIN(nb_sectors * BDRV_SECTOR_SIZE, iov->size);
298 buf = g_malloc(size);
299 qemu_iovec_to_buf(iov, 0, buf, size);
300 data = buf;
302 #endif
303 iscsi_co_init_iscsitask(iscsilun, &iTask);
304 retry:
305 iTask.task = iscsi_write16_task(iscsilun->iscsi, iscsilun->lun, lba,
306 data, num_sectors * iscsilun->block_size,
307 iscsilun->block_size, 0, 0, 0, 0, 0,
308 iscsi_co_generic_cb, &iTask);
309 if (iTask.task == NULL) {
310 g_free(buf);
311 return -EIO;
313 #if defined(LIBISCSI_FEATURE_IOVECTOR)
314 scsi_task_set_iov_out(iTask.task, (struct scsi_iovec *) iov->iov,
315 iov->niov);
316 #endif
317 while (!iTask.complete) {
318 iscsi_set_events(iscsilun);
319 qemu_coroutine_yield();
322 if (iTask.task != NULL) {
323 scsi_free_scsi_task(iTask.task);
324 iTask.task = NULL;
327 if (iTask.do_retry) {
328 goto retry;
331 g_free(buf);
333 if (iTask.status != SCSI_STATUS_GOOD) {
334 return -EIO;
337 return 0;
340 static int coroutine_fn iscsi_co_readv(BlockDriverState *bs,
341 int64_t sector_num, int nb_sectors,
342 QEMUIOVector *iov)
344 IscsiLun *iscsilun = bs->opaque;
345 struct IscsiTask iTask;
346 uint64_t lba;
347 uint32_t num_sectors;
348 #if !defined(LIBISCSI_FEATURE_IOVECTOR)
349 int i;
350 #endif
352 if (!is_request_lun_aligned(sector_num, nb_sectors, iscsilun)) {
353 return -EINVAL;
356 lba = sector_qemu2lun(sector_num, iscsilun);
357 num_sectors = sector_qemu2lun(nb_sectors, iscsilun);
359 iscsi_co_init_iscsitask(iscsilun, &iTask);
360 retry:
361 switch (iscsilun->type) {
362 case TYPE_DISK:
363 iTask.task = iscsi_read16_task(iscsilun->iscsi, iscsilun->lun, lba,
364 num_sectors * iscsilun->block_size,
365 iscsilun->block_size, 0, 0, 0, 0, 0,
366 iscsi_co_generic_cb, &iTask);
367 break;
368 default:
369 iTask.task = iscsi_read10_task(iscsilun->iscsi, iscsilun->lun, lba,
370 num_sectors * iscsilun->block_size,
371 iscsilun->block_size,
372 #if !defined(CONFIG_LIBISCSI_1_4) /* API change from 1.4.0 to 1.5.0 */
373 0, 0, 0, 0, 0,
374 #endif
375 iscsi_co_generic_cb, &iTask);
376 break;
378 if (iTask.task == NULL) {
379 return -EIO;
381 #if defined(LIBISCSI_FEATURE_IOVECTOR)
382 scsi_task_set_iov_in(iTask.task, (struct scsi_iovec *) iov->iov, iov->niov);
383 #else
384 for (i = 0; i < iov->niov; i++) {
385 scsi_task_add_data_in_buffer(iTask.task,
386 iov->iov[i].iov_len,
387 iov->iov[i].iov_base);
389 #endif
391 while (!iTask.complete) {
392 iscsi_set_events(iscsilun);
393 qemu_coroutine_yield();
396 if (iTask.task != NULL) {
397 scsi_free_scsi_task(iTask.task);
398 iTask.task = NULL;
401 if (iTask.do_retry) {
402 goto retry;
405 if (iTask.status != SCSI_STATUS_GOOD) {
406 return -EIO;
409 return 0;
412 static int coroutine_fn iscsi_co_flush(BlockDriverState *bs)
414 IscsiLun *iscsilun = bs->opaque;
415 struct IscsiTask iTask;
417 iscsi_co_init_iscsitask(iscsilun, &iTask);
419 retry:
420 if (iscsi_synchronizecache10_task(iscsilun->iscsi, iscsilun->lun, 0, 0, 0,
421 0, iscsi_co_generic_cb, &iTask) == NULL) {
422 return -EIO;
425 while (!iTask.complete) {
426 iscsi_set_events(iscsilun);
427 qemu_coroutine_yield();
430 if (iTask.task != NULL) {
431 scsi_free_scsi_task(iTask.task);
432 iTask.task = NULL;
435 if (iTask.do_retry) {
436 goto retry;
439 if (iTask.status != SCSI_STATUS_GOOD) {
440 return -EIO;
443 return 0;
446 #ifdef __linux__
447 static void
448 iscsi_aio_ioctl_cb(struct iscsi_context *iscsi, int status,
449 void *command_data, void *opaque)
451 IscsiAIOCB *acb = opaque;
453 g_free(acb->buf);
454 acb->buf = NULL;
456 if (acb->canceled != 0) {
457 return;
460 acb->status = 0;
461 if (status < 0) {
462 error_report("Failed to ioctl(SG_IO) to iSCSI lun. %s",
463 iscsi_get_error(iscsi));
464 acb->status = -EIO;
467 acb->ioh->driver_status = 0;
468 acb->ioh->host_status = 0;
469 acb->ioh->resid = 0;
471 #define SG_ERR_DRIVER_SENSE 0x08
473 if (status == SCSI_STATUS_CHECK_CONDITION && acb->task->datain.size >= 2) {
474 int ss;
476 acb->ioh->driver_status |= SG_ERR_DRIVER_SENSE;
478 acb->ioh->sb_len_wr = acb->task->datain.size - 2;
479 ss = (acb->ioh->mx_sb_len >= acb->ioh->sb_len_wr) ?
480 acb->ioh->mx_sb_len : acb->ioh->sb_len_wr;
481 memcpy(acb->ioh->sbp, &acb->task->datain.data[2], ss);
484 iscsi_schedule_bh(acb);
487 static BlockDriverAIOCB *iscsi_aio_ioctl(BlockDriverState *bs,
488 unsigned long int req, void *buf,
489 BlockDriverCompletionFunc *cb, void *opaque)
491 IscsiLun *iscsilun = bs->opaque;
492 struct iscsi_context *iscsi = iscsilun->iscsi;
493 struct iscsi_data data;
494 IscsiAIOCB *acb;
496 assert(req == SG_IO);
498 acb = qemu_aio_get(&iscsi_aiocb_info, bs, cb, opaque);
500 acb->iscsilun = iscsilun;
501 acb->canceled = 0;
502 acb->bh = NULL;
503 acb->status = -EINPROGRESS;
504 acb->buf = NULL;
505 acb->ioh = buf;
507 acb->task = malloc(sizeof(struct scsi_task));
508 if (acb->task == NULL) {
509 error_report("iSCSI: Failed to allocate task for scsi command. %s",
510 iscsi_get_error(iscsi));
511 qemu_aio_release(acb);
512 return NULL;
514 memset(acb->task, 0, sizeof(struct scsi_task));
516 switch (acb->ioh->dxfer_direction) {
517 case SG_DXFER_TO_DEV:
518 acb->task->xfer_dir = SCSI_XFER_WRITE;
519 break;
520 case SG_DXFER_FROM_DEV:
521 acb->task->xfer_dir = SCSI_XFER_READ;
522 break;
523 default:
524 acb->task->xfer_dir = SCSI_XFER_NONE;
525 break;
528 acb->task->cdb_size = acb->ioh->cmd_len;
529 memcpy(&acb->task->cdb[0], acb->ioh->cmdp, acb->ioh->cmd_len);
530 acb->task->expxferlen = acb->ioh->dxfer_len;
532 data.size = 0;
533 if (acb->task->xfer_dir == SCSI_XFER_WRITE) {
534 if (acb->ioh->iovec_count == 0) {
535 data.data = acb->ioh->dxferp;
536 data.size = acb->ioh->dxfer_len;
537 } else {
538 #if defined(LIBISCSI_FEATURE_IOVECTOR)
539 scsi_task_set_iov_out(acb->task,
540 (struct scsi_iovec *) acb->ioh->dxferp,
541 acb->ioh->iovec_count);
542 #else
543 struct iovec *iov = (struct iovec *)acb->ioh->dxferp;
545 acb->buf = g_malloc(acb->ioh->dxfer_len);
546 data.data = acb->buf;
547 data.size = iov_to_buf(iov, acb->ioh->iovec_count, 0,
548 acb->buf, acb->ioh->dxfer_len);
549 #endif
553 if (iscsi_scsi_command_async(iscsi, iscsilun->lun, acb->task,
554 iscsi_aio_ioctl_cb,
555 (data.size > 0) ? &data : NULL,
556 acb) != 0) {
557 scsi_free_scsi_task(acb->task);
558 qemu_aio_release(acb);
559 return NULL;
562 /* tell libiscsi to read straight into the buffer we got from ioctl */
563 if (acb->task->xfer_dir == SCSI_XFER_READ) {
564 if (acb->ioh->iovec_count == 0) {
565 scsi_task_add_data_in_buffer(acb->task,
566 acb->ioh->dxfer_len,
567 acb->ioh->dxferp);
568 } else {
569 #if defined(LIBISCSI_FEATURE_IOVECTOR)
570 scsi_task_set_iov_in(acb->task,
571 (struct scsi_iovec *) acb->ioh->dxferp,
572 acb->ioh->iovec_count);
573 #else
574 int i;
575 for (i = 0; i < acb->ioh->iovec_count; i++) {
576 struct iovec *iov = (struct iovec *)acb->ioh->dxferp;
578 scsi_task_add_data_in_buffer(acb->task,
579 iov[i].iov_len,
580 iov[i].iov_base);
582 #endif
586 iscsi_set_events(iscsilun);
588 return &acb->common;
592 static void ioctl_cb(void *opaque, int status)
594 int *p_status = opaque;
595 *p_status = status;
598 static int iscsi_ioctl(BlockDriverState *bs, unsigned long int req, void *buf)
600 IscsiLun *iscsilun = bs->opaque;
601 int status;
603 switch (req) {
604 case SG_GET_VERSION_NUM:
605 *(int *)buf = 30000;
606 break;
607 case SG_GET_SCSI_ID:
608 ((struct sg_scsi_id *)buf)->scsi_type = iscsilun->type;
609 break;
610 case SG_IO:
611 status = -EINPROGRESS;
612 iscsi_aio_ioctl(bs, req, buf, ioctl_cb, &status);
614 while (status == -EINPROGRESS) {
615 qemu_aio_wait();
618 return 0;
619 default:
620 return -1;
622 return 0;
624 #endif
626 static int64_t
627 iscsi_getlength(BlockDriverState *bs)
629 IscsiLun *iscsilun = bs->opaque;
630 int64_t len;
632 len = iscsilun->num_blocks;
633 len *= iscsilun->block_size;
635 return len;
638 #if defined(LIBISCSI_FEATURE_IOVECTOR)
640 static int64_t coroutine_fn iscsi_co_get_block_status(BlockDriverState *bs,
641 int64_t sector_num,
642 int nb_sectors, int *pnum)
644 IscsiLun *iscsilun = bs->opaque;
645 struct scsi_get_lba_status *lbas = NULL;
646 struct scsi_lba_status_descriptor *lbasd = NULL;
647 struct IscsiTask iTask;
648 int64_t ret;
650 iscsi_co_init_iscsitask(iscsilun, &iTask);
652 if (!is_request_lun_aligned(sector_num, nb_sectors, iscsilun)) {
653 ret = -EINVAL;
654 goto out;
657 /* default to all sectors allocated */
658 ret = BDRV_BLOCK_DATA;
659 ret |= (sector_num << BDRV_SECTOR_BITS) | BDRV_BLOCK_OFFSET_VALID;
660 *pnum = nb_sectors;
662 /* LUN does not support logical block provisioning */
663 if (iscsilun->lbpme == 0) {
664 goto out;
667 retry:
668 if (iscsi_get_lba_status_task(iscsilun->iscsi, iscsilun->lun,
669 sector_qemu2lun(sector_num, iscsilun),
670 8 + 16, iscsi_co_generic_cb,
671 &iTask) == NULL) {
672 ret = -EIO;
673 goto out;
676 while (!iTask.complete) {
677 iscsi_set_events(iscsilun);
678 qemu_coroutine_yield();
681 if (iTask.do_retry) {
682 if (iTask.task != NULL) {
683 scsi_free_scsi_task(iTask.task);
684 iTask.task = NULL;
686 goto retry;
689 if (iTask.status != SCSI_STATUS_GOOD) {
690 /* in case the get_lba_status_callout fails (i.e.
691 * because the device is busy or the cmd is not
692 * supported) we pretend all blocks are allocated
693 * for backwards compatibility */
694 goto out;
697 lbas = scsi_datain_unmarshall(iTask.task);
698 if (lbas == NULL) {
699 ret = -EIO;
700 goto out;
703 lbasd = &lbas->descriptors[0];
705 if (sector_qemu2lun(sector_num, iscsilun) != lbasd->lba) {
706 ret = -EIO;
707 goto out;
710 *pnum = sector_lun2qemu(lbasd->num_blocks, iscsilun);
711 if (*pnum > nb_sectors) {
712 *pnum = nb_sectors;
715 if (lbasd->provisioning == SCSI_PROVISIONING_TYPE_DEALLOCATED ||
716 lbasd->provisioning == SCSI_PROVISIONING_TYPE_ANCHORED) {
717 ret &= ~BDRV_BLOCK_DATA;
718 if (iscsilun->lbprz) {
719 ret |= BDRV_BLOCK_ZERO;
723 out:
724 if (iTask.task != NULL) {
725 scsi_free_scsi_task(iTask.task);
727 return ret;
730 #endif /* LIBISCSI_FEATURE_IOVECTOR */
732 static int
733 coroutine_fn iscsi_co_discard(BlockDriverState *bs, int64_t sector_num,
734 int nb_sectors)
736 IscsiLun *iscsilun = bs->opaque;
737 struct IscsiTask iTask;
738 struct unmap_list list;
740 if (!is_request_lun_aligned(sector_num, nb_sectors, iscsilun)) {
741 return -EINVAL;
744 if (!iscsilun->lbp.lbpu) {
745 /* UNMAP is not supported by the target */
746 return 0;
749 list.lba = sector_qemu2lun(sector_num, iscsilun);
750 list.num = sector_qemu2lun(nb_sectors, iscsilun);
752 iscsi_co_init_iscsitask(iscsilun, &iTask);
753 retry:
754 if (iscsi_unmap_task(iscsilun->iscsi, iscsilun->lun, 0, 0, &list, 1,
755 iscsi_co_generic_cb, &iTask) == NULL) {
756 return -EIO;
759 while (!iTask.complete) {
760 iscsi_set_events(iscsilun);
761 qemu_coroutine_yield();
764 if (iTask.task != NULL) {
765 scsi_free_scsi_task(iTask.task);
766 iTask.task = NULL;
769 if (iTask.do_retry) {
770 goto retry;
773 if (iTask.status == SCSI_STATUS_CHECK_CONDITION) {
774 /* the target might fail with a check condition if it
775 is not happy with the alignment of the UNMAP request
776 we silently fail in this case */
777 return 0;
780 if (iTask.status != SCSI_STATUS_GOOD) {
781 return -EIO;
784 return 0;
787 #if defined(SCSI_SENSE_ASCQ_CAPACITY_DATA_HAS_CHANGED)
789 static int
790 coroutine_fn iscsi_co_write_zeroes(BlockDriverState *bs, int64_t sector_num,
791 int nb_sectors, BdrvRequestFlags flags)
793 IscsiLun *iscsilun = bs->opaque;
794 struct IscsiTask iTask;
795 uint64_t lba;
796 uint32_t nb_blocks;
798 if (!is_request_lun_aligned(sector_num, nb_sectors, iscsilun)) {
799 return -EINVAL;
802 if (!(flags & BDRV_REQ_MAY_UNMAP) && !iscsilun->has_write_same) {
803 /* WRITE SAME without UNMAP is not supported by the target */
804 return -ENOTSUP;
807 if ((flags & BDRV_REQ_MAY_UNMAP) && !iscsilun->lbp.lbpws) {
808 /* WRITE SAME with UNMAP is not supported by the target */
809 return -ENOTSUP;
812 lba = sector_qemu2lun(sector_num, iscsilun);
813 nb_blocks = sector_qemu2lun(nb_sectors, iscsilun);
815 if (iscsilun->zeroblock == NULL) {
816 iscsilun->zeroblock = g_malloc0(iscsilun->block_size);
819 iscsi_co_init_iscsitask(iscsilun, &iTask);
820 retry:
821 if (iscsi_writesame16_task(iscsilun->iscsi, iscsilun->lun, lba,
822 iscsilun->zeroblock, iscsilun->block_size,
823 nb_blocks, 0, !!(flags & BDRV_REQ_MAY_UNMAP),
824 0, 0, iscsi_co_generic_cb, &iTask) == NULL) {
825 return -EIO;
828 while (!iTask.complete) {
829 iscsi_set_events(iscsilun);
830 qemu_coroutine_yield();
833 if (iTask.task != NULL) {
834 scsi_free_scsi_task(iTask.task);
835 iTask.task = NULL;
838 if (iTask.do_retry) {
839 goto retry;
842 if (iTask.status != SCSI_STATUS_GOOD) {
843 if (iTask.status == SCSI_STATUS_CHECK_CONDITION &&
844 iTask.task->sense.key == SCSI_SENSE_ILLEGAL_REQUEST &&
845 iTask.task->sense.ascq == SCSI_SENSE_ASCQ_INVALID_OPERATION_CODE) {
846 /* WRITE SAME is not supported by the target */
847 iscsilun->has_write_same = false;
848 return -ENOTSUP;
851 return -EIO;
854 return 0;
857 #endif /* SCSI_SENSE_ASCQ_CAPACITY_DATA_HAS_CHANGED */
859 static int parse_chap(struct iscsi_context *iscsi, const char *target)
861 QemuOptsList *list;
862 QemuOpts *opts;
863 const char *user = NULL;
864 const char *password = NULL;
866 list = qemu_find_opts("iscsi");
867 if (!list) {
868 return 0;
871 opts = qemu_opts_find(list, target);
872 if (opts == NULL) {
873 opts = QTAILQ_FIRST(&list->head);
874 if (!opts) {
875 return 0;
879 user = qemu_opt_get(opts, "user");
880 if (!user) {
881 return 0;
884 password = qemu_opt_get(opts, "password");
885 if (!password) {
886 error_report("CHAP username specified but no password was given");
887 return -1;
890 if (iscsi_set_initiator_username_pwd(iscsi, user, password)) {
891 error_report("Failed to set initiator username and password");
892 return -1;
895 return 0;
898 static void parse_header_digest(struct iscsi_context *iscsi, const char *target)
900 QemuOptsList *list;
901 QemuOpts *opts;
902 const char *digest = NULL;
904 list = qemu_find_opts("iscsi");
905 if (!list) {
906 return;
909 opts = qemu_opts_find(list, target);
910 if (opts == NULL) {
911 opts = QTAILQ_FIRST(&list->head);
912 if (!opts) {
913 return;
917 digest = qemu_opt_get(opts, "header-digest");
918 if (!digest) {
919 return;
922 if (!strcmp(digest, "CRC32C")) {
923 iscsi_set_header_digest(iscsi, ISCSI_HEADER_DIGEST_CRC32C);
924 } else if (!strcmp(digest, "NONE")) {
925 iscsi_set_header_digest(iscsi, ISCSI_HEADER_DIGEST_NONE);
926 } else if (!strcmp(digest, "CRC32C-NONE")) {
927 iscsi_set_header_digest(iscsi, ISCSI_HEADER_DIGEST_CRC32C_NONE);
928 } else if (!strcmp(digest, "NONE-CRC32C")) {
929 iscsi_set_header_digest(iscsi, ISCSI_HEADER_DIGEST_NONE_CRC32C);
930 } else {
931 error_report("Invalid header-digest setting : %s", digest);
935 static char *parse_initiator_name(const char *target)
937 QemuOptsList *list;
938 QemuOpts *opts;
939 const char *name;
940 char *iscsi_name;
941 UuidInfo *uuid_info;
943 list = qemu_find_opts("iscsi");
944 if (list) {
945 opts = qemu_opts_find(list, target);
946 if (!opts) {
947 opts = QTAILQ_FIRST(&list->head);
949 if (opts) {
950 name = qemu_opt_get(opts, "initiator-name");
951 if (name) {
952 return g_strdup(name);
957 uuid_info = qmp_query_uuid(NULL);
958 if (strcmp(uuid_info->UUID, UUID_NONE) == 0) {
959 name = qemu_get_vm_name();
960 } else {
961 name = uuid_info->UUID;
963 iscsi_name = g_strdup_printf("iqn.2008-11.org.linux-kvm%s%s",
964 name ? ":" : "", name ? name : "");
965 qapi_free_UuidInfo(uuid_info);
966 return iscsi_name;
969 #if defined(LIBISCSI_FEATURE_NOP_COUNTER)
970 static void iscsi_nop_timed_event(void *opaque)
972 IscsiLun *iscsilun = opaque;
974 if (iscsi_get_nops_in_flight(iscsilun->iscsi) > MAX_NOP_FAILURES) {
975 error_report("iSCSI: NOP timeout. Reconnecting...");
976 iscsi_reconnect(iscsilun->iscsi);
979 if (iscsi_nop_out_async(iscsilun->iscsi, NULL, NULL, 0, NULL) != 0) {
980 error_report("iSCSI: failed to sent NOP-Out. Disabling NOP messages.");
981 return;
984 timer_mod(iscsilun->nop_timer, qemu_clock_get_ms(QEMU_CLOCK_REALTIME) + NOP_INTERVAL);
985 iscsi_set_events(iscsilun);
987 #endif
989 static int iscsi_readcapacity_sync(IscsiLun *iscsilun)
991 struct scsi_task *task = NULL;
992 struct scsi_readcapacity10 *rc10 = NULL;
993 struct scsi_readcapacity16 *rc16 = NULL;
994 int ret = 0;
995 int retries = ISCSI_CMD_RETRIES;
997 do {
998 if (task != NULL) {
999 scsi_free_scsi_task(task);
1000 task = NULL;
1003 switch (iscsilun->type) {
1004 case TYPE_DISK:
1005 task = iscsi_readcapacity16_sync(iscsilun->iscsi, iscsilun->lun);
1006 if (task != NULL && task->status == SCSI_STATUS_GOOD) {
1007 rc16 = scsi_datain_unmarshall(task);
1008 if (rc16 == NULL) {
1009 error_report("iSCSI: Failed to unmarshall readcapacity16 data.");
1010 ret = -EINVAL;
1011 } else {
1012 iscsilun->block_size = rc16->block_length;
1013 iscsilun->num_blocks = rc16->returned_lba + 1;
1014 iscsilun->lbpme = rc16->lbpme;
1015 iscsilun->lbprz = rc16->lbprz;
1018 break;
1019 case TYPE_ROM:
1020 task = iscsi_readcapacity10_sync(iscsilun->iscsi, iscsilun->lun, 0, 0);
1021 if (task != NULL && task->status == SCSI_STATUS_GOOD) {
1022 rc10 = scsi_datain_unmarshall(task);
1023 if (rc10 == NULL) {
1024 error_report("iSCSI: Failed to unmarshall readcapacity10 data.");
1025 ret = -EINVAL;
1026 } else {
1027 iscsilun->block_size = rc10->block_size;
1028 if (rc10->lba == 0) {
1029 /* blank disk loaded */
1030 iscsilun->num_blocks = 0;
1031 } else {
1032 iscsilun->num_blocks = rc10->lba + 1;
1036 break;
1037 default:
1038 return 0;
1040 } while (task != NULL && task->status == SCSI_STATUS_CHECK_CONDITION
1041 && task->sense.key == SCSI_SENSE_UNIT_ATTENTION
1042 && retries-- > 0);
1044 if (task == NULL || task->status != SCSI_STATUS_GOOD) {
1045 error_report("iSCSI: failed to send readcapacity10 command.");
1046 ret = -EINVAL;
1048 if (task) {
1049 scsi_free_scsi_task(task);
1051 return ret;
1054 /* TODO Convert to fine grained options */
1055 static QemuOptsList runtime_opts = {
1056 .name = "iscsi",
1057 .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
1058 .desc = {
1060 .name = "filename",
1061 .type = QEMU_OPT_STRING,
1062 .help = "URL to the iscsi image",
1064 { /* end of list */ }
1068 static struct scsi_task *iscsi_do_inquiry(struct iscsi_context *iscsi,
1069 int lun, int evpd, int pc) {
1070 int full_size;
1071 struct scsi_task *task = NULL;
1072 task = iscsi_inquiry_sync(iscsi, lun, evpd, pc, 64);
1073 if (task == NULL || task->status != SCSI_STATUS_GOOD) {
1074 goto fail;
1076 full_size = scsi_datain_getfullsize(task);
1077 if (full_size > task->datain.size) {
1078 scsi_free_scsi_task(task);
1080 /* we need more data for the full list */
1081 task = iscsi_inquiry_sync(iscsi, lun, evpd, pc, full_size);
1082 if (task == NULL || task->status != SCSI_STATUS_GOOD) {
1083 goto fail;
1087 return task;
1089 fail:
1090 error_report("iSCSI: Inquiry command failed : %s",
1091 iscsi_get_error(iscsi));
1092 if (task) {
1093 scsi_free_scsi_task(task);
1094 return NULL;
1096 return NULL;
1100 * We support iscsi url's on the form
1101 * iscsi://[<username>%<password>@]<host>[:<port>]/<targetname>/<lun>
1103 static int iscsi_open(BlockDriverState *bs, QDict *options, int flags,
1104 Error **errp)
1106 IscsiLun *iscsilun = bs->opaque;
1107 struct iscsi_context *iscsi = NULL;
1108 struct iscsi_url *iscsi_url = NULL;
1109 struct scsi_task *task = NULL;
1110 struct scsi_inquiry_standard *inq = NULL;
1111 char *initiator_name = NULL;
1112 QemuOpts *opts;
1113 Error *local_err = NULL;
1114 const char *filename;
1115 int ret;
1117 if ((BDRV_SECTOR_SIZE % 512) != 0) {
1118 error_report("iSCSI: Invalid BDRV_SECTOR_SIZE. "
1119 "BDRV_SECTOR_SIZE(%lld) is not a multiple "
1120 "of 512", BDRV_SECTOR_SIZE);
1121 return -EINVAL;
1124 opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
1125 qemu_opts_absorb_qdict(opts, options, &local_err);
1126 if (error_is_set(&local_err)) {
1127 qerror_report_err(local_err);
1128 error_free(local_err);
1129 ret = -EINVAL;
1130 goto out;
1133 filename = qemu_opt_get(opts, "filename");
1136 iscsi_url = iscsi_parse_full_url(iscsi, filename);
1137 if (iscsi_url == NULL) {
1138 error_report("Failed to parse URL : %s", filename);
1139 ret = -EINVAL;
1140 goto out;
1143 memset(iscsilun, 0, sizeof(IscsiLun));
1145 initiator_name = parse_initiator_name(iscsi_url->target);
1147 iscsi = iscsi_create_context(initiator_name);
1148 if (iscsi == NULL) {
1149 error_report("iSCSI: Failed to create iSCSI context.");
1150 ret = -ENOMEM;
1151 goto out;
1154 if (iscsi_set_targetname(iscsi, iscsi_url->target)) {
1155 error_report("iSCSI: Failed to set target name.");
1156 ret = -EINVAL;
1157 goto out;
1160 if (iscsi_url->user != NULL) {
1161 ret = iscsi_set_initiator_username_pwd(iscsi, iscsi_url->user,
1162 iscsi_url->passwd);
1163 if (ret != 0) {
1164 error_report("Failed to set initiator username and password");
1165 ret = -EINVAL;
1166 goto out;
1170 /* check if we got CHAP username/password via the options */
1171 if (parse_chap(iscsi, iscsi_url->target) != 0) {
1172 error_report("iSCSI: Failed to set CHAP user/password");
1173 ret = -EINVAL;
1174 goto out;
1177 if (iscsi_set_session_type(iscsi, ISCSI_SESSION_NORMAL) != 0) {
1178 error_report("iSCSI: Failed to set session type to normal.");
1179 ret = -EINVAL;
1180 goto out;
1183 iscsi_set_header_digest(iscsi, ISCSI_HEADER_DIGEST_NONE_CRC32C);
1185 /* check if we got HEADER_DIGEST via the options */
1186 parse_header_digest(iscsi, iscsi_url->target);
1188 if (iscsi_full_connect_sync(iscsi, iscsi_url->portal, iscsi_url->lun) != 0) {
1189 error_report("iSCSI: Failed to connect to LUN : %s",
1190 iscsi_get_error(iscsi));
1191 ret = -EINVAL;
1192 goto out;
1195 iscsilun->iscsi = iscsi;
1196 iscsilun->lun = iscsi_url->lun;
1198 task = iscsi_inquiry_sync(iscsi, iscsilun->lun, 0, 0, 36);
1200 if (task == NULL || task->status != SCSI_STATUS_GOOD) {
1201 error_report("iSCSI: failed to send inquiry command.");
1202 ret = -EINVAL;
1203 goto out;
1206 inq = scsi_datain_unmarshall(task);
1207 if (inq == NULL) {
1208 error_report("iSCSI: Failed to unmarshall inquiry data.");
1209 ret = -EINVAL;
1210 goto out;
1213 iscsilun->type = inq->periperal_device_type;
1214 iscsilun->has_write_same = true;
1216 if ((ret = iscsi_readcapacity_sync(iscsilun)) != 0) {
1217 goto out;
1219 bs->total_sectors = sector_lun2qemu(iscsilun->num_blocks, iscsilun);
1221 /* Medium changer or tape. We dont have any emulation for this so this must
1222 * be sg ioctl compatible. We force it to be sg, otherwise qemu will try
1223 * to read from the device to guess the image format.
1225 if (iscsilun->type == TYPE_MEDIUM_CHANGER ||
1226 iscsilun->type == TYPE_TAPE) {
1227 bs->sg = 1;
1230 if (iscsilun->lbpme) {
1231 struct scsi_inquiry_logical_block_provisioning *inq_lbp;
1232 task = iscsi_do_inquiry(iscsilun->iscsi, iscsilun->lun, 1,
1233 SCSI_INQUIRY_PAGECODE_LOGICAL_BLOCK_PROVISIONING);
1234 if (task == NULL) {
1235 ret = -EINVAL;
1236 goto out;
1238 inq_lbp = scsi_datain_unmarshall(task);
1239 if (inq_lbp == NULL) {
1240 error_report("iSCSI: failed to unmarshall inquiry datain blob");
1241 ret = -EINVAL;
1242 goto out;
1244 memcpy(&iscsilun->lbp, inq_lbp,
1245 sizeof(struct scsi_inquiry_logical_block_provisioning));
1246 scsi_free_scsi_task(task);
1247 task = NULL;
1250 if (iscsilun->lbp.lbpu || iscsilun->lbp.lbpws) {
1251 struct scsi_inquiry_block_limits *inq_bl;
1252 task = iscsi_do_inquiry(iscsilun->iscsi, iscsilun->lun, 1,
1253 SCSI_INQUIRY_PAGECODE_BLOCK_LIMITS);
1254 if (task == NULL) {
1255 ret = -EINVAL;
1256 goto out;
1258 inq_bl = scsi_datain_unmarshall(task);
1259 if (inq_bl == NULL) {
1260 error_report("iSCSI: failed to unmarshall inquiry datain blob");
1261 ret = -EINVAL;
1262 goto out;
1264 memcpy(&iscsilun->bl, inq_bl,
1265 sizeof(struct scsi_inquiry_block_limits));
1266 scsi_free_scsi_task(task);
1267 task = NULL;
1269 if (iscsilun->bl.max_unmap < 0xffffffff) {
1270 bs->bl.max_discard = sector_lun2qemu(iscsilun->bl.max_unmap,
1271 iscsilun);
1273 bs->bl.discard_alignment = sector_lun2qemu(iscsilun->bl.opt_unmap_gran,
1274 iscsilun);
1276 if (iscsilun->bl.max_ws_len < 0xffffffff) {
1277 bs->bl.max_write_zeroes = sector_lun2qemu(iscsilun->bl.max_ws_len,
1278 iscsilun);
1280 bs->bl.write_zeroes_alignment = sector_lun2qemu(iscsilun->bl.opt_unmap_gran,
1281 iscsilun);
1283 bs->bl.opt_transfer_length = sector_lun2qemu(iscsilun->bl.opt_xfer_len,
1284 iscsilun);
1287 #if defined(LIBISCSI_FEATURE_NOP_COUNTER)
1288 /* Set up a timer for sending out iSCSI NOPs */
1289 iscsilun->nop_timer = timer_new_ms(QEMU_CLOCK_REALTIME, iscsi_nop_timed_event, iscsilun);
1290 timer_mod(iscsilun->nop_timer, qemu_clock_get_ms(QEMU_CLOCK_REALTIME) + NOP_INTERVAL);
1291 #endif
1293 out:
1294 qemu_opts_del(opts);
1295 if (initiator_name != NULL) {
1296 g_free(initiator_name);
1298 if (iscsi_url != NULL) {
1299 iscsi_destroy_url(iscsi_url);
1301 if (task != NULL) {
1302 scsi_free_scsi_task(task);
1305 if (ret) {
1306 if (iscsi != NULL) {
1307 iscsi_destroy_context(iscsi);
1309 memset(iscsilun, 0, sizeof(IscsiLun));
1311 return ret;
1314 static void iscsi_close(BlockDriverState *bs)
1316 IscsiLun *iscsilun = bs->opaque;
1317 struct iscsi_context *iscsi = iscsilun->iscsi;
1319 if (iscsilun->nop_timer) {
1320 timer_del(iscsilun->nop_timer);
1321 timer_free(iscsilun->nop_timer);
1323 qemu_aio_set_fd_handler(iscsi_get_fd(iscsi), NULL, NULL, NULL);
1324 iscsi_destroy_context(iscsi);
1325 g_free(iscsilun->zeroblock);
1326 memset(iscsilun, 0, sizeof(IscsiLun));
1329 static int iscsi_truncate(BlockDriverState *bs, int64_t offset)
1331 IscsiLun *iscsilun = bs->opaque;
1332 int ret = 0;
1334 if (iscsilun->type != TYPE_DISK) {
1335 return -ENOTSUP;
1338 if ((ret = iscsi_readcapacity_sync(iscsilun)) != 0) {
1339 return ret;
1342 if (offset > iscsi_getlength(bs)) {
1343 return -EINVAL;
1346 return 0;
1349 static int iscsi_create(const char *filename, QEMUOptionParameter *options,
1350 Error **errp)
1352 int ret = 0;
1353 int64_t total_size = 0;
1354 BlockDriverState *bs;
1355 IscsiLun *iscsilun = NULL;
1356 QDict *bs_options;
1358 bs = bdrv_new("");
1360 /* Read out options */
1361 while (options && options->name) {
1362 if (!strcmp(options->name, "size")) {
1363 total_size = options->value.n / BDRV_SECTOR_SIZE;
1365 options++;
1368 bs->opaque = g_malloc0(sizeof(struct IscsiLun));
1369 iscsilun = bs->opaque;
1371 bs_options = qdict_new();
1372 qdict_put(bs_options, "filename", qstring_from_str(filename));
1373 ret = iscsi_open(bs, bs_options, 0, NULL);
1374 QDECREF(bs_options);
1376 if (ret != 0) {
1377 goto out;
1379 if (iscsilun->nop_timer) {
1380 timer_del(iscsilun->nop_timer);
1381 timer_free(iscsilun->nop_timer);
1383 if (iscsilun->type != TYPE_DISK) {
1384 ret = -ENODEV;
1385 goto out;
1387 if (bs->total_sectors < total_size) {
1388 ret = -ENOSPC;
1389 goto out;
1392 ret = 0;
1393 out:
1394 if (iscsilun->iscsi != NULL) {
1395 iscsi_destroy_context(iscsilun->iscsi);
1397 g_free(bs->opaque);
1398 bs->opaque = NULL;
1399 bdrv_unref(bs);
1400 return ret;
1403 static int iscsi_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
1405 IscsiLun *iscsilun = bs->opaque;
1406 bdi->unallocated_blocks_are_zero = !!iscsilun->lbprz;
1407 bdi->can_write_zeroes_with_unmap = iscsilun->lbprz && iscsilun->lbp.lbpws;
1408 /* Guess the internal cluster (page) size of the iscsi target by the means
1409 * of opt_unmap_gran. Transfer the unmap granularity only if it has a
1410 * reasonable size for bdi->cluster_size */
1411 if (iscsilun->bl.opt_unmap_gran * iscsilun->block_size >= 64 * 1024 &&
1412 iscsilun->bl.opt_unmap_gran * iscsilun->block_size <= 16 * 1024 * 1024) {
1413 bdi->cluster_size = iscsilun->bl.opt_unmap_gran * iscsilun->block_size;
1415 return 0;
1418 static QEMUOptionParameter iscsi_create_options[] = {
1420 .name = BLOCK_OPT_SIZE,
1421 .type = OPT_SIZE,
1422 .help = "Virtual disk size"
1424 { NULL }
1427 static BlockDriver bdrv_iscsi = {
1428 .format_name = "iscsi",
1429 .protocol_name = "iscsi",
1431 .instance_size = sizeof(IscsiLun),
1432 .bdrv_needs_filename = true,
1433 .bdrv_file_open = iscsi_open,
1434 .bdrv_close = iscsi_close,
1435 .bdrv_create = iscsi_create,
1436 .create_options = iscsi_create_options,
1438 .bdrv_getlength = iscsi_getlength,
1439 .bdrv_get_info = iscsi_get_info,
1440 .bdrv_truncate = iscsi_truncate,
1442 #if defined(LIBISCSI_FEATURE_IOVECTOR)
1443 .bdrv_co_get_block_status = iscsi_co_get_block_status,
1444 #endif
1445 .bdrv_co_discard = iscsi_co_discard,
1446 #if defined(SCSI_SENSE_ASCQ_CAPACITY_DATA_HAS_CHANGED)
1447 .bdrv_co_write_zeroes = iscsi_co_write_zeroes,
1448 #endif
1449 .bdrv_co_readv = iscsi_co_readv,
1450 .bdrv_co_writev = iscsi_co_writev,
1451 .bdrv_co_flush_to_disk = iscsi_co_flush,
1453 #ifdef __linux__
1454 .bdrv_ioctl = iscsi_ioctl,
1455 .bdrv_aio_ioctl = iscsi_aio_ioctl,
1456 #endif
1459 static QemuOptsList qemu_iscsi_opts = {
1460 .name = "iscsi",
1461 .head = QTAILQ_HEAD_INITIALIZER(qemu_iscsi_opts.head),
1462 .desc = {
1464 .name = "user",
1465 .type = QEMU_OPT_STRING,
1466 .help = "username for CHAP authentication to target",
1468 .name = "password",
1469 .type = QEMU_OPT_STRING,
1470 .help = "password for CHAP authentication to target",
1472 .name = "header-digest",
1473 .type = QEMU_OPT_STRING,
1474 .help = "HeaderDigest setting. "
1475 "{CRC32C|CRC32C-NONE|NONE-CRC32C|NONE}",
1477 .name = "initiator-name",
1478 .type = QEMU_OPT_STRING,
1479 .help = "Initiator iqn name to use when connecting",
1481 { /* end of list */ }
1485 static void iscsi_block_init(void)
1487 bdrv_register(&bdrv_iscsi);
1488 qemu_add_opts(&qemu_iscsi_opts);
1491 block_init(iscsi_block_init);