xref: /qemu/block/iscsi.c (revision cea25275)
1 /*
2  * QEMU Block driver for iSCSI images
3  *
4  * Copyright (c) 2010-2011 Ronnie Sahlberg <ronniesahlberg@gmail.com>
5  * Copyright (c) 2012-2016 Peter Lieven <pl@kamp.de>
6  *
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:
13  *
14  * The above copyright notice and this permission notice shall be included in
15  * all copies or substantial portions of the Software.
16  *
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.
24  */
25 
26 #include "qemu/osdep.h"
27 
28 #include <poll.h>
29 #include <math.h>
30 #include <arpa/inet.h>
31 #include "qemu-common.h"
32 #include "qemu/config-file.h"
33 #include "qemu/error-report.h"
34 #include "qemu/bitops.h"
35 #include "qemu/bitmap.h"
36 #include "block/block_int.h"
37 #include "block/scsi.h"
38 #include "qemu/iov.h"
39 #include "qemu/uuid.h"
40 #include "qmp-commands.h"
41 #include "qapi/qmp/qstring.h"
42 #include "crypto/secret.h"
43 
44 #include <iscsi/iscsi.h>
45 #include <iscsi/scsi-lowlevel.h>
46 
47 #ifdef __linux__
48 #include <scsi/sg.h>
49 #endif
50 
51 typedef struct IscsiLun {
52     struct iscsi_context *iscsi;
53     AioContext *aio_context;
54     int lun;
55     enum scsi_inquiry_peripheral_device_type type;
56     int block_size;
57     uint64_t num_blocks;
58     int events;
59     QEMUTimer *nop_timer;
60     QEMUTimer *event_timer;
61     struct scsi_inquiry_logical_block_provisioning lbp;
62     struct scsi_inquiry_block_limits bl;
63     unsigned char *zeroblock;
64     /* The allocmap tracks which clusters (pages) on the iSCSI target are
65      * allocated and which are not. In case a target returns zeros for
66      * unallocated pages (iscsilun->lprz) we can directly return zeros instead
67      * of reading zeros over the wire if a read request falls within an
68      * unallocated block. As there are 3 possible states we need 2 bitmaps to
69      * track. allocmap_valid keeps track if QEMU's information about a page is
70      * valid. allocmap tracks if a page is allocated or not. In case QEMU has no
71      * valid information about a page the corresponding allocmap entry should be
72      * switched to unallocated as well to force a new lookup of the allocation
73      * status as lookups are generally skipped if a page is suspect to be
74      * allocated. If a iSCSI target is opened with cache.direct = on the
75      * allocmap_valid does not exist turning all cached information invalid so
76      * that a fresh lookup is made for any page even if allocmap entry returns
77      * it's unallocated. */
78     unsigned long *allocmap;
79     unsigned long *allocmap_valid;
80     long allocmap_size;
81     int cluster_sectors;
82     bool use_16_for_rw;
83     bool write_protected;
84     bool lbpme;
85     bool lbprz;
86     bool dpofua;
87     bool has_write_same;
88     bool request_timed_out;
89 } IscsiLun;
90 
91 typedef struct IscsiTask {
92     int status;
93     int complete;
94     int retries;
95     int do_retry;
96     struct scsi_task *task;
97     Coroutine *co;
98     QEMUBH *bh;
99     IscsiLun *iscsilun;
100     QEMUTimer retry_timer;
101     int err_code;
102 } IscsiTask;
103 
104 typedef struct IscsiAIOCB {
105     BlockAIOCB common;
106     QEMUIOVector *qiov;
107     QEMUBH *bh;
108     IscsiLun *iscsilun;
109     struct scsi_task *task;
110     uint8_t *buf;
111     int status;
112     int64_t sector_num;
113     int nb_sectors;
114     int ret;
115 #ifdef __linux__
116     sg_io_hdr_t *ioh;
117 #endif
118 } IscsiAIOCB;
119 
120 /* libiscsi uses time_t so its enough to process events every second */
121 #define EVENT_INTERVAL 1000
122 #define NOP_INTERVAL 5000
123 #define MAX_NOP_FAILURES 3
124 #define ISCSI_CMD_RETRIES ARRAY_SIZE(iscsi_retry_times)
125 static const unsigned iscsi_retry_times[] = {8, 32, 128, 512, 2048, 8192, 32768};
126 
127 /* this threshold is a trade-off knob to choose between
128  * the potential additional overhead of an extra GET_LBA_STATUS request
129  * vs. unnecessarily reading a lot of zero sectors over the wire.
130  * If a read request is greater or equal than ISCSI_CHECKALLOC_THRES
131  * sectors we check the allocation status of the area covered by the
132  * request first if the allocationmap indicates that the area might be
133  * unallocated. */
134 #define ISCSI_CHECKALLOC_THRES 64
135 
136 static void
137 iscsi_bh_cb(void *p)
138 {
139     IscsiAIOCB *acb = p;
140 
141     qemu_bh_delete(acb->bh);
142 
143     g_free(acb->buf);
144     acb->buf = NULL;
145 
146     acb->common.cb(acb->common.opaque, acb->status);
147 
148     if (acb->task != NULL) {
149         scsi_free_scsi_task(acb->task);
150         acb->task = NULL;
151     }
152 
153     qemu_aio_unref(acb);
154 }
155 
156 static void
157 iscsi_schedule_bh(IscsiAIOCB *acb)
158 {
159     if (acb->bh) {
160         return;
161     }
162     acb->bh = aio_bh_new(acb->iscsilun->aio_context, iscsi_bh_cb, acb);
163     qemu_bh_schedule(acb->bh);
164 }
165 
166 static void iscsi_co_generic_bh_cb(void *opaque)
167 {
168     struct IscsiTask *iTask = opaque;
169     iTask->complete = 1;
170     qemu_bh_delete(iTask->bh);
171     qemu_coroutine_enter(iTask->co);
172 }
173 
174 static void iscsi_retry_timer_expired(void *opaque)
175 {
176     struct IscsiTask *iTask = opaque;
177     iTask->complete = 1;
178     if (iTask->co) {
179         qemu_coroutine_enter(iTask->co);
180     }
181 }
182 
183 static inline unsigned exp_random(double mean)
184 {
185     return -mean * log((double)rand() / RAND_MAX);
186 }
187 
188 /* SCSI_SENSE_ASCQ_INVALID_FIELD_IN_PARAMETER_LIST was introduced in
189  * libiscsi 1.10.0, together with other constants we need.  Use it as
190  * a hint that we have to define them ourselves if needed, to keep the
191  * minimum required libiscsi version at 1.9.0.  We use an ASCQ macro for
192  * the test because SCSI_STATUS_* is an enum.
193  *
194  * To guard against future changes where SCSI_SENSE_ASCQ_* also becomes
195  * an enum, check against the LIBISCSI_API_VERSION macro, which was
196  * introduced in 1.11.0.  If it is present, there is no need to define
197  * anything.
198  */
199 #if !defined(SCSI_SENSE_ASCQ_INVALID_FIELD_IN_PARAMETER_LIST) && \
200     !defined(LIBISCSI_API_VERSION)
201 #define SCSI_STATUS_TASK_SET_FULL                          0x28
202 #define SCSI_STATUS_TIMEOUT                                0x0f000002
203 #define SCSI_SENSE_ASCQ_INVALID_FIELD_IN_PARAMETER_LIST    0x2600
204 #define SCSI_SENSE_ASCQ_PARAMETER_LIST_LENGTH_ERROR        0x1a00
205 #endif
206 
207 static int iscsi_translate_sense(struct scsi_sense *sense)
208 {
209     int ret;
210 
211     switch (sense->key) {
212     case SCSI_SENSE_NOT_READY:
213         return -EBUSY;
214     case SCSI_SENSE_DATA_PROTECTION:
215         return -EACCES;
216     case SCSI_SENSE_COMMAND_ABORTED:
217         return -ECANCELED;
218     case SCSI_SENSE_ILLEGAL_REQUEST:
219         /* Parse ASCQ */
220         break;
221     default:
222         return -EIO;
223     }
224     switch (sense->ascq) {
225     case SCSI_SENSE_ASCQ_PARAMETER_LIST_LENGTH_ERROR:
226     case SCSI_SENSE_ASCQ_INVALID_OPERATION_CODE:
227     case SCSI_SENSE_ASCQ_INVALID_FIELD_IN_CDB:
228     case SCSI_SENSE_ASCQ_INVALID_FIELD_IN_PARAMETER_LIST:
229         ret = -EINVAL;
230         break;
231     case SCSI_SENSE_ASCQ_LBA_OUT_OF_RANGE:
232         ret = -ENOSPC;
233         break;
234     case SCSI_SENSE_ASCQ_LOGICAL_UNIT_NOT_SUPPORTED:
235         ret = -ENOTSUP;
236         break;
237     case SCSI_SENSE_ASCQ_MEDIUM_NOT_PRESENT:
238     case SCSI_SENSE_ASCQ_MEDIUM_NOT_PRESENT_TRAY_CLOSED:
239     case SCSI_SENSE_ASCQ_MEDIUM_NOT_PRESENT_TRAY_OPEN:
240         ret = -ENOMEDIUM;
241         break;
242     case SCSI_SENSE_ASCQ_WRITE_PROTECTED:
243         ret = -EACCES;
244         break;
245     default:
246         ret = -EIO;
247         break;
248     }
249     return ret;
250 }
251 
252 static void
253 iscsi_co_generic_cb(struct iscsi_context *iscsi, int status,
254                         void *command_data, void *opaque)
255 {
256     struct IscsiTask *iTask = opaque;
257     struct scsi_task *task = command_data;
258 
259     iTask->status = status;
260     iTask->do_retry = 0;
261     iTask->task = task;
262 
263     if (status != SCSI_STATUS_GOOD) {
264         if (iTask->retries++ < ISCSI_CMD_RETRIES) {
265             if (status == SCSI_STATUS_CHECK_CONDITION
266                 && task->sense.key == SCSI_SENSE_UNIT_ATTENTION) {
267                 error_report("iSCSI CheckCondition: %s",
268                              iscsi_get_error(iscsi));
269                 iTask->do_retry = 1;
270                 goto out;
271             }
272             if (status == SCSI_STATUS_BUSY ||
273                 status == SCSI_STATUS_TIMEOUT ||
274                 status == SCSI_STATUS_TASK_SET_FULL) {
275                 unsigned retry_time =
276                     exp_random(iscsi_retry_times[iTask->retries - 1]);
277                 if (status == SCSI_STATUS_TIMEOUT) {
278                     /* make sure the request is rescheduled AFTER the
279                      * reconnect is initiated */
280                     retry_time = EVENT_INTERVAL * 2;
281                     iTask->iscsilun->request_timed_out = true;
282                 }
283                 error_report("iSCSI Busy/TaskSetFull/TimeOut"
284                              " (retry #%u in %u ms): %s",
285                              iTask->retries, retry_time,
286                              iscsi_get_error(iscsi));
287                 aio_timer_init(iTask->iscsilun->aio_context,
288                                &iTask->retry_timer, QEMU_CLOCK_REALTIME,
289                                SCALE_MS, iscsi_retry_timer_expired, iTask);
290                 timer_mod(&iTask->retry_timer,
291                           qemu_clock_get_ms(QEMU_CLOCK_REALTIME) + retry_time);
292                 iTask->do_retry = 1;
293                 return;
294             }
295         }
296         iTask->err_code = iscsi_translate_sense(&task->sense);
297         error_report("iSCSI Failure: %s", iscsi_get_error(iscsi));
298     }
299 
300 out:
301     if (iTask->co) {
302         iTask->bh = aio_bh_new(iTask->iscsilun->aio_context,
303                                iscsi_co_generic_bh_cb, iTask);
304         qemu_bh_schedule(iTask->bh);
305     } else {
306         iTask->complete = 1;
307     }
308 }
309 
310 static void iscsi_co_init_iscsitask(IscsiLun *iscsilun, struct IscsiTask *iTask)
311 {
312     *iTask = (struct IscsiTask) {
313         .co         = qemu_coroutine_self(),
314         .iscsilun   = iscsilun,
315     };
316 }
317 
318 static void
319 iscsi_abort_task_cb(struct iscsi_context *iscsi, int status, void *command_data,
320                     void *private_data)
321 {
322     IscsiAIOCB *acb = private_data;
323 
324     acb->status = -ECANCELED;
325     iscsi_schedule_bh(acb);
326 }
327 
328 static void
329 iscsi_aio_cancel(BlockAIOCB *blockacb)
330 {
331     IscsiAIOCB *acb = (IscsiAIOCB *)blockacb;
332     IscsiLun *iscsilun = acb->iscsilun;
333 
334     if (acb->status != -EINPROGRESS) {
335         return;
336     }
337 
338     /* send a task mgmt call to the target to cancel the task on the target */
339     iscsi_task_mgmt_abort_task_async(iscsilun->iscsi, acb->task,
340                                      iscsi_abort_task_cb, acb);
341 
342 }
343 
344 static const AIOCBInfo iscsi_aiocb_info = {
345     .aiocb_size         = sizeof(IscsiAIOCB),
346     .cancel_async       = iscsi_aio_cancel,
347 };
348 
349 
350 static void iscsi_process_read(void *arg);
351 static void iscsi_process_write(void *arg);
352 
353 static void
354 iscsi_set_events(IscsiLun *iscsilun)
355 {
356     struct iscsi_context *iscsi = iscsilun->iscsi;
357     int ev = iscsi_which_events(iscsi);
358 
359     if (ev != iscsilun->events) {
360         aio_set_fd_handler(iscsilun->aio_context, iscsi_get_fd(iscsi),
361                            false,
362                            (ev & POLLIN) ? iscsi_process_read : NULL,
363                            (ev & POLLOUT) ? iscsi_process_write : NULL,
364                            iscsilun);
365         iscsilun->events = ev;
366     }
367 }
368 
369 static void iscsi_timed_check_events(void *opaque)
370 {
371     IscsiLun *iscsilun = opaque;
372 
373     /* check for timed out requests */
374     iscsi_service(iscsilun->iscsi, 0);
375 
376     if (iscsilun->request_timed_out) {
377         iscsilun->request_timed_out = false;
378         iscsi_reconnect(iscsilun->iscsi);
379     }
380 
381     /* newer versions of libiscsi may return zero events. Ensure we are able
382      * to return to service once this situation changes. */
383     iscsi_set_events(iscsilun);
384 
385     timer_mod(iscsilun->event_timer,
386               qemu_clock_get_ms(QEMU_CLOCK_REALTIME) + EVENT_INTERVAL);
387 }
388 
389 static void
390 iscsi_process_read(void *arg)
391 {
392     IscsiLun *iscsilun = arg;
393     struct iscsi_context *iscsi = iscsilun->iscsi;
394 
395     iscsi_service(iscsi, POLLIN);
396     iscsi_set_events(iscsilun);
397 }
398 
399 static void
400 iscsi_process_write(void *arg)
401 {
402     IscsiLun *iscsilun = arg;
403     struct iscsi_context *iscsi = iscsilun->iscsi;
404 
405     iscsi_service(iscsi, POLLOUT);
406     iscsi_set_events(iscsilun);
407 }
408 
409 static int64_t sector_lun2qemu(int64_t sector, IscsiLun *iscsilun)
410 {
411     return sector * iscsilun->block_size / BDRV_SECTOR_SIZE;
412 }
413 
414 static int64_t sector_qemu2lun(int64_t sector, IscsiLun *iscsilun)
415 {
416     return sector * BDRV_SECTOR_SIZE / iscsilun->block_size;
417 }
418 
419 static bool is_byte_request_lun_aligned(int64_t offset, int count,
420                                         IscsiLun *iscsilun)
421 {
422     if (offset % iscsilun->block_size || count % iscsilun->block_size) {
423         error_report("iSCSI misaligned request: "
424                      "iscsilun->block_size %u, offset %" PRIi64
425                      ", count %d",
426                      iscsilun->block_size, offset, count);
427         return false;
428     }
429     return true;
430 }
431 
432 static bool is_sector_request_lun_aligned(int64_t sector_num, int nb_sectors,
433                                           IscsiLun *iscsilun)
434 {
435     assert(nb_sectors <= BDRV_REQUEST_MAX_SECTORS);
436     return is_byte_request_lun_aligned(sector_num << BDRV_SECTOR_BITS,
437                                        nb_sectors << BDRV_SECTOR_BITS,
438                                        iscsilun);
439 }
440 
441 static void iscsi_allocmap_free(IscsiLun *iscsilun)
442 {
443     g_free(iscsilun->allocmap);
444     g_free(iscsilun->allocmap_valid);
445     iscsilun->allocmap = NULL;
446     iscsilun->allocmap_valid = NULL;
447 }
448 
449 
450 static int iscsi_allocmap_init(IscsiLun *iscsilun, int open_flags)
451 {
452     iscsi_allocmap_free(iscsilun);
453 
454     iscsilun->allocmap_size =
455         DIV_ROUND_UP(sector_lun2qemu(iscsilun->num_blocks, iscsilun),
456                      iscsilun->cluster_sectors);
457 
458     iscsilun->allocmap = bitmap_try_new(iscsilun->allocmap_size);
459     if (!iscsilun->allocmap) {
460         return -ENOMEM;
461     }
462 
463     if (open_flags & BDRV_O_NOCACHE) {
464         /* in case that cache.direct = on all allocmap entries are
465          * treated as invalid to force a relookup of the block
466          * status on every read request */
467         return 0;
468     }
469 
470     iscsilun->allocmap_valid = bitmap_try_new(iscsilun->allocmap_size);
471     if (!iscsilun->allocmap_valid) {
472         /* if we are under memory pressure free the allocmap as well */
473         iscsi_allocmap_free(iscsilun);
474         return -ENOMEM;
475     }
476 
477     return 0;
478 }
479 
480 static void
481 iscsi_allocmap_update(IscsiLun *iscsilun, int64_t sector_num,
482                       int nb_sectors, bool allocated, bool valid)
483 {
484     int64_t cl_num_expanded, nb_cls_expanded, cl_num_shrunk, nb_cls_shrunk;
485 
486     if (iscsilun->allocmap == NULL) {
487         return;
488     }
489     /* expand to entirely contain all affected clusters */
490     cl_num_expanded = sector_num / iscsilun->cluster_sectors;
491     nb_cls_expanded = DIV_ROUND_UP(sector_num + nb_sectors,
492                                    iscsilun->cluster_sectors) - cl_num_expanded;
493     /* shrink to touch only completely contained clusters */
494     cl_num_shrunk = DIV_ROUND_UP(sector_num, iscsilun->cluster_sectors);
495     nb_cls_shrunk = (sector_num + nb_sectors) / iscsilun->cluster_sectors
496                       - cl_num_shrunk;
497     if (allocated) {
498         bitmap_set(iscsilun->allocmap, cl_num_expanded, nb_cls_expanded);
499     } else {
500         bitmap_clear(iscsilun->allocmap, cl_num_shrunk, nb_cls_shrunk);
501     }
502 
503     if (iscsilun->allocmap_valid == NULL) {
504         return;
505     }
506     if (valid) {
507         bitmap_set(iscsilun->allocmap_valid, cl_num_shrunk, nb_cls_shrunk);
508     } else {
509         bitmap_clear(iscsilun->allocmap_valid, cl_num_expanded,
510                      nb_cls_expanded);
511     }
512 }
513 
514 static void
515 iscsi_allocmap_set_allocated(IscsiLun *iscsilun, int64_t sector_num,
516                              int nb_sectors)
517 {
518     iscsi_allocmap_update(iscsilun, sector_num, nb_sectors, true, true);
519 }
520 
521 static void
522 iscsi_allocmap_set_unallocated(IscsiLun *iscsilun, int64_t sector_num,
523                                int nb_sectors)
524 {
525     /* Note: if cache.direct=on the fifth argument to iscsi_allocmap_update
526      * is ignored, so this will in effect be an iscsi_allocmap_set_invalid.
527      */
528     iscsi_allocmap_update(iscsilun, sector_num, nb_sectors, false, true);
529 }
530 
531 static void iscsi_allocmap_set_invalid(IscsiLun *iscsilun, int64_t sector_num,
532                                        int nb_sectors)
533 {
534     iscsi_allocmap_update(iscsilun, sector_num, nb_sectors, false, false);
535 }
536 
537 static void iscsi_allocmap_invalidate(IscsiLun *iscsilun)
538 {
539     if (iscsilun->allocmap) {
540         bitmap_zero(iscsilun->allocmap, iscsilun->allocmap_size);
541     }
542     if (iscsilun->allocmap_valid) {
543         bitmap_zero(iscsilun->allocmap_valid, iscsilun->allocmap_size);
544     }
545 }
546 
547 static inline bool
548 iscsi_allocmap_is_allocated(IscsiLun *iscsilun, int64_t sector_num,
549                             int nb_sectors)
550 {
551     unsigned long size;
552     if (iscsilun->allocmap == NULL) {
553         return true;
554     }
555     size = DIV_ROUND_UP(sector_num + nb_sectors, iscsilun->cluster_sectors);
556     return !(find_next_bit(iscsilun->allocmap, size,
557                            sector_num / iscsilun->cluster_sectors) == size);
558 }
559 
560 static inline bool iscsi_allocmap_is_valid(IscsiLun *iscsilun,
561                                            int64_t sector_num, int nb_sectors)
562 {
563     unsigned long size;
564     if (iscsilun->allocmap_valid == NULL) {
565         return false;
566     }
567     size = DIV_ROUND_UP(sector_num + nb_sectors, iscsilun->cluster_sectors);
568     return (find_next_zero_bit(iscsilun->allocmap_valid, size,
569                                sector_num / iscsilun->cluster_sectors) == size);
570 }
571 
572 static int coroutine_fn
573 iscsi_co_writev_flags(BlockDriverState *bs, int64_t sector_num, int nb_sectors,
574                       QEMUIOVector *iov, int flags)
575 {
576     IscsiLun *iscsilun = bs->opaque;
577     struct IscsiTask iTask;
578     uint64_t lba;
579     uint32_t num_sectors;
580     bool fua = flags & BDRV_REQ_FUA;
581 
582     if (fua) {
583         assert(iscsilun->dpofua);
584     }
585     if (!is_sector_request_lun_aligned(sector_num, nb_sectors, iscsilun)) {
586         return -EINVAL;
587     }
588 
589     if (bs->bl.max_transfer) {
590         assert(nb_sectors << BDRV_SECTOR_BITS <= bs->bl.max_transfer);
591     }
592 
593     lba = sector_qemu2lun(sector_num, iscsilun);
594     num_sectors = sector_qemu2lun(nb_sectors, iscsilun);
595     iscsi_co_init_iscsitask(iscsilun, &iTask);
596 retry:
597     if (iscsilun->use_16_for_rw) {
598         iTask.task = iscsi_write16_task(iscsilun->iscsi, iscsilun->lun, lba,
599                                         NULL, num_sectors * iscsilun->block_size,
600                                         iscsilun->block_size, 0, 0, fua, 0, 0,
601                                         iscsi_co_generic_cb, &iTask);
602     } else {
603         iTask.task = iscsi_write10_task(iscsilun->iscsi, iscsilun->lun, lba,
604                                         NULL, num_sectors * iscsilun->block_size,
605                                         iscsilun->block_size, 0, 0, fua, 0, 0,
606                                         iscsi_co_generic_cb, &iTask);
607     }
608     if (iTask.task == NULL) {
609         return -ENOMEM;
610     }
611     scsi_task_set_iov_out(iTask.task, (struct scsi_iovec *) iov->iov,
612                           iov->niov);
613     while (!iTask.complete) {
614         iscsi_set_events(iscsilun);
615         qemu_coroutine_yield();
616     }
617 
618     if (iTask.task != NULL) {
619         scsi_free_scsi_task(iTask.task);
620         iTask.task = NULL;
621     }
622 
623     if (iTask.do_retry) {
624         iTask.complete = 0;
625         goto retry;
626     }
627 
628     if (iTask.status != SCSI_STATUS_GOOD) {
629         iscsi_allocmap_set_invalid(iscsilun, sector_num, nb_sectors);
630         return iTask.err_code;
631     }
632 
633     iscsi_allocmap_set_allocated(iscsilun, sector_num, nb_sectors);
634 
635     return 0;
636 }
637 
638 
639 
640 static int64_t coroutine_fn iscsi_co_get_block_status(BlockDriverState *bs,
641                                                   int64_t sector_num,
642                                                   int nb_sectors, int *pnum,
643                                                   BlockDriverState **file)
644 {
645     IscsiLun *iscsilun = bs->opaque;
646     struct scsi_get_lba_status *lbas = NULL;
647     struct scsi_lba_status_descriptor *lbasd = NULL;
648     struct IscsiTask iTask;
649     int64_t ret;
650 
651     iscsi_co_init_iscsitask(iscsilun, &iTask);
652 
653     if (!is_sector_request_lun_aligned(sector_num, nb_sectors, iscsilun)) {
654         ret = -EINVAL;
655         goto out;
656     }
657 
658     /* default to all sectors allocated */
659     ret = BDRV_BLOCK_DATA;
660     ret |= (sector_num << BDRV_SECTOR_BITS) | BDRV_BLOCK_OFFSET_VALID;
661     *pnum = nb_sectors;
662 
663     /* LUN does not support logical block provisioning */
664     if (!iscsilun->lbpme) {
665         goto out;
666     }
667 
668 retry:
669     if (iscsi_get_lba_status_task(iscsilun->iscsi, iscsilun->lun,
670                                   sector_qemu2lun(sector_num, iscsilun),
671                                   8 + 16, iscsi_co_generic_cb,
672                                   &iTask) == NULL) {
673         ret = -ENOMEM;
674         goto out;
675     }
676 
677     while (!iTask.complete) {
678         iscsi_set_events(iscsilun);
679         qemu_coroutine_yield();
680     }
681 
682     if (iTask.do_retry) {
683         if (iTask.task != NULL) {
684             scsi_free_scsi_task(iTask.task);
685             iTask.task = NULL;
686         }
687         iTask.complete = 0;
688         goto retry;
689     }
690 
691     if (iTask.status != SCSI_STATUS_GOOD) {
692         /* in case the get_lba_status_callout fails (i.e.
693          * because the device is busy or the cmd is not
694          * supported) we pretend all blocks are allocated
695          * for backwards compatibility */
696         goto out;
697     }
698 
699     lbas = scsi_datain_unmarshall(iTask.task);
700     if (lbas == NULL) {
701         ret = -EIO;
702         goto out;
703     }
704 
705     lbasd = &lbas->descriptors[0];
706 
707     if (sector_qemu2lun(sector_num, iscsilun) != lbasd->lba) {
708         ret = -EIO;
709         goto out;
710     }
711 
712     *pnum = sector_lun2qemu(lbasd->num_blocks, iscsilun);
713 
714     if (lbasd->provisioning == SCSI_PROVISIONING_TYPE_DEALLOCATED ||
715         lbasd->provisioning == SCSI_PROVISIONING_TYPE_ANCHORED) {
716         ret &= ~BDRV_BLOCK_DATA;
717         if (iscsilun->lbprz) {
718             ret |= BDRV_BLOCK_ZERO;
719         }
720     }
721 
722     if (ret & BDRV_BLOCK_ZERO) {
723         iscsi_allocmap_set_unallocated(iscsilun, sector_num, *pnum);
724     } else {
725         iscsi_allocmap_set_allocated(iscsilun, sector_num, *pnum);
726     }
727 
728     if (*pnum > nb_sectors) {
729         *pnum = nb_sectors;
730     }
731 out:
732     if (iTask.task != NULL) {
733         scsi_free_scsi_task(iTask.task);
734     }
735     if (ret > 0 && ret & BDRV_BLOCK_OFFSET_VALID) {
736         *file = bs;
737     }
738     return ret;
739 }
740 
741 static int coroutine_fn iscsi_co_readv(BlockDriverState *bs,
742                                        int64_t sector_num, int nb_sectors,
743                                        QEMUIOVector *iov)
744 {
745     IscsiLun *iscsilun = bs->opaque;
746     struct IscsiTask iTask;
747     uint64_t lba;
748     uint32_t num_sectors;
749 
750     if (!is_sector_request_lun_aligned(sector_num, nb_sectors, iscsilun)) {
751         return -EINVAL;
752     }
753 
754     if (bs->bl.max_transfer) {
755         assert(nb_sectors << BDRV_SECTOR_BITS <= bs->bl.max_transfer);
756     }
757 
758     /* if cache.direct is off and we have a valid entry in our allocation map
759      * we can skip checking the block status and directly return zeroes if
760      * the request falls within an unallocated area */
761     if (iscsi_allocmap_is_valid(iscsilun, sector_num, nb_sectors) &&
762         !iscsi_allocmap_is_allocated(iscsilun, sector_num, nb_sectors)) {
763             qemu_iovec_memset(iov, 0, 0x00, iov->size);
764             return 0;
765     }
766 
767     if (nb_sectors >= ISCSI_CHECKALLOC_THRES &&
768         !iscsi_allocmap_is_valid(iscsilun, sector_num, nb_sectors) &&
769         !iscsi_allocmap_is_allocated(iscsilun, sector_num, nb_sectors)) {
770         int pnum;
771         BlockDriverState *file;
772         /* check the block status from the beginning of the cluster
773          * containing the start sector */
774         int64_t ret = iscsi_co_get_block_status(bs,
775                           sector_num - sector_num % iscsilun->cluster_sectors,
776                           BDRV_REQUEST_MAX_SECTORS, &pnum, &file);
777         if (ret < 0) {
778             return ret;
779         }
780         /* if the whole request falls into an unallocated area we can avoid
781          * to read and directly return zeroes instead */
782         if (ret & BDRV_BLOCK_ZERO &&
783             pnum >= nb_sectors + sector_num % iscsilun->cluster_sectors) {
784             qemu_iovec_memset(iov, 0, 0x00, iov->size);
785             return 0;
786         }
787     }
788 
789     lba = sector_qemu2lun(sector_num, iscsilun);
790     num_sectors = sector_qemu2lun(nb_sectors, iscsilun);
791 
792     iscsi_co_init_iscsitask(iscsilun, &iTask);
793 retry:
794     if (iscsilun->use_16_for_rw) {
795         iTask.task = iscsi_read16_task(iscsilun->iscsi, iscsilun->lun, lba,
796                                        num_sectors * iscsilun->block_size,
797                                        iscsilun->block_size, 0, 0, 0, 0, 0,
798                                        iscsi_co_generic_cb, &iTask);
799     } else {
800         iTask.task = iscsi_read10_task(iscsilun->iscsi, iscsilun->lun, lba,
801                                        num_sectors * iscsilun->block_size,
802                                        iscsilun->block_size,
803                                        0, 0, 0, 0, 0,
804                                        iscsi_co_generic_cb, &iTask);
805     }
806     if (iTask.task == NULL) {
807         return -ENOMEM;
808     }
809     scsi_task_set_iov_in(iTask.task, (struct scsi_iovec *) iov->iov, iov->niov);
810 
811     while (!iTask.complete) {
812         iscsi_set_events(iscsilun);
813         qemu_coroutine_yield();
814     }
815 
816     if (iTask.task != NULL) {
817         scsi_free_scsi_task(iTask.task);
818         iTask.task = NULL;
819     }
820 
821     if (iTask.do_retry) {
822         iTask.complete = 0;
823         goto retry;
824     }
825 
826     if (iTask.status != SCSI_STATUS_GOOD) {
827         return iTask.err_code;
828     }
829 
830     return 0;
831 }
832 
833 static int coroutine_fn iscsi_co_flush(BlockDriverState *bs)
834 {
835     IscsiLun *iscsilun = bs->opaque;
836     struct IscsiTask iTask;
837 
838     iscsi_co_init_iscsitask(iscsilun, &iTask);
839 retry:
840     if (iscsi_synchronizecache10_task(iscsilun->iscsi, iscsilun->lun, 0, 0, 0,
841                                       0, iscsi_co_generic_cb, &iTask) == NULL) {
842         return -ENOMEM;
843     }
844 
845     while (!iTask.complete) {
846         iscsi_set_events(iscsilun);
847         qemu_coroutine_yield();
848     }
849 
850     if (iTask.task != NULL) {
851         scsi_free_scsi_task(iTask.task);
852         iTask.task = NULL;
853     }
854 
855     if (iTask.do_retry) {
856         iTask.complete = 0;
857         goto retry;
858     }
859 
860     if (iTask.status != SCSI_STATUS_GOOD) {
861         return iTask.err_code;
862     }
863 
864     return 0;
865 }
866 
867 #ifdef __linux__
868 static void
869 iscsi_aio_ioctl_cb(struct iscsi_context *iscsi, int status,
870                      void *command_data, void *opaque)
871 {
872     IscsiAIOCB *acb = opaque;
873 
874     g_free(acb->buf);
875     acb->buf = NULL;
876 
877     acb->status = 0;
878     if (status < 0) {
879         error_report("Failed to ioctl(SG_IO) to iSCSI lun. %s",
880                      iscsi_get_error(iscsi));
881         acb->status = iscsi_translate_sense(&acb->task->sense);
882     }
883 
884     acb->ioh->driver_status = 0;
885     acb->ioh->host_status   = 0;
886     acb->ioh->resid         = 0;
887     acb->ioh->status        = status;
888 
889 #define SG_ERR_DRIVER_SENSE    0x08
890 
891     if (status == SCSI_STATUS_CHECK_CONDITION && acb->task->datain.size >= 2) {
892         int ss;
893 
894         acb->ioh->driver_status |= SG_ERR_DRIVER_SENSE;
895 
896         acb->ioh->sb_len_wr = acb->task->datain.size - 2;
897         ss = (acb->ioh->mx_sb_len >= acb->ioh->sb_len_wr) ?
898              acb->ioh->mx_sb_len : acb->ioh->sb_len_wr;
899         memcpy(acb->ioh->sbp, &acb->task->datain.data[2], ss);
900     }
901 
902     iscsi_schedule_bh(acb);
903 }
904 
905 static void iscsi_ioctl_bh_completion(void *opaque)
906 {
907     IscsiAIOCB *acb = opaque;
908 
909     qemu_bh_delete(acb->bh);
910     acb->common.cb(acb->common.opaque, acb->ret);
911     qemu_aio_unref(acb);
912 }
913 
914 static void iscsi_ioctl_handle_emulated(IscsiAIOCB *acb, int req, void *buf)
915 {
916     BlockDriverState *bs = acb->common.bs;
917     IscsiLun *iscsilun = bs->opaque;
918     int ret = 0;
919 
920     switch (req) {
921     case SG_GET_VERSION_NUM:
922         *(int *)buf = 30000;
923         break;
924     case SG_GET_SCSI_ID:
925         ((struct sg_scsi_id *)buf)->scsi_type = iscsilun->type;
926         break;
927     default:
928         ret = -EINVAL;
929     }
930     assert(!acb->bh);
931     acb->bh = aio_bh_new(bdrv_get_aio_context(bs),
932                          iscsi_ioctl_bh_completion, acb);
933     acb->ret = ret;
934     qemu_bh_schedule(acb->bh);
935 }
936 
937 static BlockAIOCB *iscsi_aio_ioctl(BlockDriverState *bs,
938         unsigned long int req, void *buf,
939         BlockCompletionFunc *cb, void *opaque)
940 {
941     IscsiLun *iscsilun = bs->opaque;
942     struct iscsi_context *iscsi = iscsilun->iscsi;
943     struct iscsi_data data;
944     IscsiAIOCB *acb;
945 
946     acb = qemu_aio_get(&iscsi_aiocb_info, bs, cb, opaque);
947 
948     acb->iscsilun = iscsilun;
949     acb->bh          = NULL;
950     acb->status      = -EINPROGRESS;
951     acb->buf         = NULL;
952     acb->ioh         = buf;
953 
954     if (req != SG_IO) {
955         iscsi_ioctl_handle_emulated(acb, req, buf);
956         return &acb->common;
957     }
958 
959     if (acb->ioh->cmd_len > SCSI_CDB_MAX_SIZE) {
960         error_report("iSCSI: ioctl error CDB exceeds max size (%d > %d)",
961                      acb->ioh->cmd_len, SCSI_CDB_MAX_SIZE);
962         qemu_aio_unref(acb);
963         return NULL;
964     }
965 
966     acb->task = malloc(sizeof(struct scsi_task));
967     if (acb->task == NULL) {
968         error_report("iSCSI: Failed to allocate task for scsi command. %s",
969                      iscsi_get_error(iscsi));
970         qemu_aio_unref(acb);
971         return NULL;
972     }
973     memset(acb->task, 0, sizeof(struct scsi_task));
974 
975     switch (acb->ioh->dxfer_direction) {
976     case SG_DXFER_TO_DEV:
977         acb->task->xfer_dir = SCSI_XFER_WRITE;
978         break;
979     case SG_DXFER_FROM_DEV:
980         acb->task->xfer_dir = SCSI_XFER_READ;
981         break;
982     default:
983         acb->task->xfer_dir = SCSI_XFER_NONE;
984         break;
985     }
986 
987     acb->task->cdb_size = acb->ioh->cmd_len;
988     memcpy(&acb->task->cdb[0], acb->ioh->cmdp, acb->ioh->cmd_len);
989     acb->task->expxferlen = acb->ioh->dxfer_len;
990 
991     data.size = 0;
992     if (acb->task->xfer_dir == SCSI_XFER_WRITE) {
993         if (acb->ioh->iovec_count == 0) {
994             data.data = acb->ioh->dxferp;
995             data.size = acb->ioh->dxfer_len;
996         } else {
997             scsi_task_set_iov_out(acb->task,
998                                  (struct scsi_iovec *) acb->ioh->dxferp,
999                                  acb->ioh->iovec_count);
1000         }
1001     }
1002 
1003     if (iscsi_scsi_command_async(iscsi, iscsilun->lun, acb->task,
1004                                  iscsi_aio_ioctl_cb,
1005                                  (data.size > 0) ? &data : NULL,
1006                                  acb) != 0) {
1007         scsi_free_scsi_task(acb->task);
1008         qemu_aio_unref(acb);
1009         return NULL;
1010     }
1011 
1012     /* tell libiscsi to read straight into the buffer we got from ioctl */
1013     if (acb->task->xfer_dir == SCSI_XFER_READ) {
1014         if (acb->ioh->iovec_count == 0) {
1015             scsi_task_add_data_in_buffer(acb->task,
1016                                          acb->ioh->dxfer_len,
1017                                          acb->ioh->dxferp);
1018         } else {
1019             scsi_task_set_iov_in(acb->task,
1020                                  (struct scsi_iovec *) acb->ioh->dxferp,
1021                                  acb->ioh->iovec_count);
1022         }
1023     }
1024 
1025     iscsi_set_events(iscsilun);
1026 
1027     return &acb->common;
1028 }
1029 
1030 #endif
1031 
1032 static int64_t
1033 iscsi_getlength(BlockDriverState *bs)
1034 {
1035     IscsiLun *iscsilun = bs->opaque;
1036     int64_t len;
1037 
1038     len  = iscsilun->num_blocks;
1039     len *= iscsilun->block_size;
1040 
1041     return len;
1042 }
1043 
1044 static int
1045 coroutine_fn iscsi_co_pdiscard(BlockDriverState *bs, int64_t offset, int count)
1046 {
1047     IscsiLun *iscsilun = bs->opaque;
1048     struct IscsiTask iTask;
1049     struct unmap_list list;
1050 
1051     assert(is_byte_request_lun_aligned(offset, count, iscsilun));
1052 
1053     if (!iscsilun->lbp.lbpu) {
1054         /* UNMAP is not supported by the target */
1055         return 0;
1056     }
1057 
1058     list.lba = offset / iscsilun->block_size;
1059     list.num = count / iscsilun->block_size;
1060 
1061     iscsi_co_init_iscsitask(iscsilun, &iTask);
1062 retry:
1063     if (iscsi_unmap_task(iscsilun->iscsi, iscsilun->lun, 0, 0, &list, 1,
1064                          iscsi_co_generic_cb, &iTask) == NULL) {
1065         return -ENOMEM;
1066     }
1067 
1068     while (!iTask.complete) {
1069         iscsi_set_events(iscsilun);
1070         qemu_coroutine_yield();
1071     }
1072 
1073     if (iTask.task != NULL) {
1074         scsi_free_scsi_task(iTask.task);
1075         iTask.task = NULL;
1076     }
1077 
1078     if (iTask.do_retry) {
1079         iTask.complete = 0;
1080         goto retry;
1081     }
1082 
1083     if (iTask.status == SCSI_STATUS_CHECK_CONDITION) {
1084         /* the target might fail with a check condition if it
1085            is not happy with the alignment of the UNMAP request
1086            we silently fail in this case */
1087         return 0;
1088     }
1089 
1090     if (iTask.status != SCSI_STATUS_GOOD) {
1091         return iTask.err_code;
1092     }
1093 
1094     iscsi_allocmap_set_invalid(iscsilun, offset >> BDRV_SECTOR_BITS,
1095                                count >> BDRV_SECTOR_BITS);
1096 
1097     return 0;
1098 }
1099 
1100 static int
1101 coroutine_fn iscsi_co_pwrite_zeroes(BlockDriverState *bs, int64_t offset,
1102                                     int count, BdrvRequestFlags flags)
1103 {
1104     IscsiLun *iscsilun = bs->opaque;
1105     struct IscsiTask iTask;
1106     uint64_t lba;
1107     uint32_t nb_blocks;
1108     bool use_16_for_ws = iscsilun->use_16_for_rw;
1109 
1110     if (!is_byte_request_lun_aligned(offset, count, iscsilun)) {
1111         return -ENOTSUP;
1112     }
1113 
1114     if (flags & BDRV_REQ_MAY_UNMAP) {
1115         if (!use_16_for_ws && !iscsilun->lbp.lbpws10) {
1116             /* WRITESAME10 with UNMAP is unsupported try WRITESAME16 */
1117             use_16_for_ws = true;
1118         }
1119         if (use_16_for_ws && !iscsilun->lbp.lbpws) {
1120             /* WRITESAME16 with UNMAP is not supported by the target,
1121              * fall back and try WRITESAME10/16 without UNMAP */
1122             flags &= ~BDRV_REQ_MAY_UNMAP;
1123             use_16_for_ws = iscsilun->use_16_for_rw;
1124         }
1125     }
1126 
1127     if (!(flags & BDRV_REQ_MAY_UNMAP) && !iscsilun->has_write_same) {
1128         /* WRITESAME without UNMAP is not supported by the target */
1129         return -ENOTSUP;
1130     }
1131 
1132     lba = offset / iscsilun->block_size;
1133     nb_blocks = count / iscsilun->block_size;
1134 
1135     if (iscsilun->zeroblock == NULL) {
1136         iscsilun->zeroblock = g_try_malloc0(iscsilun->block_size);
1137         if (iscsilun->zeroblock == NULL) {
1138             return -ENOMEM;
1139         }
1140     }
1141 
1142     iscsi_co_init_iscsitask(iscsilun, &iTask);
1143 retry:
1144     if (use_16_for_ws) {
1145         iTask.task = iscsi_writesame16_task(iscsilun->iscsi, iscsilun->lun, lba,
1146                                             iscsilun->zeroblock, iscsilun->block_size,
1147                                             nb_blocks, 0, !!(flags & BDRV_REQ_MAY_UNMAP),
1148                                             0, 0, iscsi_co_generic_cb, &iTask);
1149     } else {
1150         iTask.task = iscsi_writesame10_task(iscsilun->iscsi, iscsilun->lun, lba,
1151                                             iscsilun->zeroblock, iscsilun->block_size,
1152                                             nb_blocks, 0, !!(flags & BDRV_REQ_MAY_UNMAP),
1153                                             0, 0, iscsi_co_generic_cb, &iTask);
1154     }
1155     if (iTask.task == NULL) {
1156         return -ENOMEM;
1157     }
1158 
1159     while (!iTask.complete) {
1160         iscsi_set_events(iscsilun);
1161         qemu_coroutine_yield();
1162     }
1163 
1164     if (iTask.status == SCSI_STATUS_CHECK_CONDITION &&
1165         iTask.task->sense.key == SCSI_SENSE_ILLEGAL_REQUEST &&
1166         (iTask.task->sense.ascq == SCSI_SENSE_ASCQ_INVALID_OPERATION_CODE ||
1167          iTask.task->sense.ascq == SCSI_SENSE_ASCQ_INVALID_FIELD_IN_CDB)) {
1168         /* WRITE SAME is not supported by the target */
1169         iscsilun->has_write_same = false;
1170         scsi_free_scsi_task(iTask.task);
1171         return -ENOTSUP;
1172     }
1173 
1174     if (iTask.task != NULL) {
1175         scsi_free_scsi_task(iTask.task);
1176         iTask.task = NULL;
1177     }
1178 
1179     if (iTask.do_retry) {
1180         iTask.complete = 0;
1181         goto retry;
1182     }
1183 
1184     if (iTask.status != SCSI_STATUS_GOOD) {
1185         iscsi_allocmap_set_invalid(iscsilun, offset >> BDRV_SECTOR_BITS,
1186                                    count >> BDRV_SECTOR_BITS);
1187         return iTask.err_code;
1188     }
1189 
1190     if (flags & BDRV_REQ_MAY_UNMAP) {
1191         iscsi_allocmap_set_invalid(iscsilun, offset >> BDRV_SECTOR_BITS,
1192                                    count >> BDRV_SECTOR_BITS);
1193     } else {
1194         iscsi_allocmap_set_allocated(iscsilun, offset >> BDRV_SECTOR_BITS,
1195                                      count >> BDRV_SECTOR_BITS);
1196     }
1197 
1198     return 0;
1199 }
1200 
1201 static void parse_chap(struct iscsi_context *iscsi, const char *target,
1202                        Error **errp)
1203 {
1204     QemuOptsList *list;
1205     QemuOpts *opts;
1206     const char *user = NULL;
1207     const char *password = NULL;
1208     const char *secretid;
1209     char *secret = NULL;
1210 
1211     list = qemu_find_opts("iscsi");
1212     if (!list) {
1213         return;
1214     }
1215 
1216     opts = qemu_opts_find(list, target);
1217     if (opts == NULL) {
1218         opts = QTAILQ_FIRST(&list->head);
1219         if (!opts) {
1220             return;
1221         }
1222     }
1223 
1224     user = qemu_opt_get(opts, "user");
1225     if (!user) {
1226         return;
1227     }
1228 
1229     secretid = qemu_opt_get(opts, "password-secret");
1230     password = qemu_opt_get(opts, "password");
1231     if (secretid && password) {
1232         error_setg(errp, "'password' and 'password-secret' properties are "
1233                    "mutually exclusive");
1234         return;
1235     }
1236     if (secretid) {
1237         secret = qcrypto_secret_lookup_as_utf8(secretid, errp);
1238         if (!secret) {
1239             return;
1240         }
1241         password = secret;
1242     } else if (!password) {
1243         error_setg(errp, "CHAP username specified but no password was given");
1244         return;
1245     }
1246 
1247     if (iscsi_set_initiator_username_pwd(iscsi, user, password)) {
1248         error_setg(errp, "Failed to set initiator username and password");
1249     }
1250 
1251     g_free(secret);
1252 }
1253 
1254 static void parse_header_digest(struct iscsi_context *iscsi, const char *target,
1255                                 Error **errp)
1256 {
1257     QemuOptsList *list;
1258     QemuOpts *opts;
1259     const char *digest = NULL;
1260 
1261     list = qemu_find_opts("iscsi");
1262     if (!list) {
1263         return;
1264     }
1265 
1266     opts = qemu_opts_find(list, target);
1267     if (opts == NULL) {
1268         opts = QTAILQ_FIRST(&list->head);
1269         if (!opts) {
1270             return;
1271         }
1272     }
1273 
1274     digest = qemu_opt_get(opts, "header-digest");
1275     if (!digest) {
1276         return;
1277     }
1278 
1279     if (!strcmp(digest, "CRC32C")) {
1280         iscsi_set_header_digest(iscsi, ISCSI_HEADER_DIGEST_CRC32C);
1281     } else if (!strcmp(digest, "NONE")) {
1282         iscsi_set_header_digest(iscsi, ISCSI_HEADER_DIGEST_NONE);
1283     } else if (!strcmp(digest, "CRC32C-NONE")) {
1284         iscsi_set_header_digest(iscsi, ISCSI_HEADER_DIGEST_CRC32C_NONE);
1285     } else if (!strcmp(digest, "NONE-CRC32C")) {
1286         iscsi_set_header_digest(iscsi, ISCSI_HEADER_DIGEST_NONE_CRC32C);
1287     } else {
1288         error_setg(errp, "Invalid header-digest setting : %s", digest);
1289     }
1290 }
1291 
1292 static char *parse_initiator_name(const char *target)
1293 {
1294     QemuOptsList *list;
1295     QemuOpts *opts;
1296     const char *name;
1297     char *iscsi_name;
1298     UuidInfo *uuid_info;
1299 
1300     list = qemu_find_opts("iscsi");
1301     if (list) {
1302         opts = qemu_opts_find(list, target);
1303         if (!opts) {
1304             opts = QTAILQ_FIRST(&list->head);
1305         }
1306         if (opts) {
1307             name = qemu_opt_get(opts, "initiator-name");
1308             if (name) {
1309                 return g_strdup(name);
1310             }
1311         }
1312     }
1313 
1314     uuid_info = qmp_query_uuid(NULL);
1315     if (strcmp(uuid_info->UUID, UUID_NONE) == 0) {
1316         name = qemu_get_vm_name();
1317     } else {
1318         name = uuid_info->UUID;
1319     }
1320     iscsi_name = g_strdup_printf("iqn.2008-11.org.linux-kvm%s%s",
1321                                  name ? ":" : "", name ? name : "");
1322     qapi_free_UuidInfo(uuid_info);
1323     return iscsi_name;
1324 }
1325 
1326 static int parse_timeout(const char *target)
1327 {
1328     QemuOptsList *list;
1329     QemuOpts *opts;
1330     const char *timeout;
1331 
1332     list = qemu_find_opts("iscsi");
1333     if (list) {
1334         opts = qemu_opts_find(list, target);
1335         if (!opts) {
1336             opts = QTAILQ_FIRST(&list->head);
1337         }
1338         if (opts) {
1339             timeout = qemu_opt_get(opts, "timeout");
1340             if (timeout) {
1341                 return atoi(timeout);
1342             }
1343         }
1344     }
1345 
1346     return 0;
1347 }
1348 
1349 static void iscsi_nop_timed_event(void *opaque)
1350 {
1351     IscsiLun *iscsilun = opaque;
1352 
1353     if (iscsi_get_nops_in_flight(iscsilun->iscsi) >= MAX_NOP_FAILURES) {
1354         error_report("iSCSI: NOP timeout. Reconnecting...");
1355         iscsilun->request_timed_out = true;
1356     } else if (iscsi_nop_out_async(iscsilun->iscsi, NULL, NULL, 0, NULL) != 0) {
1357         error_report("iSCSI: failed to sent NOP-Out. Disabling NOP messages.");
1358         return;
1359     }
1360 
1361     timer_mod(iscsilun->nop_timer, qemu_clock_get_ms(QEMU_CLOCK_REALTIME) + NOP_INTERVAL);
1362     iscsi_set_events(iscsilun);
1363 }
1364 
1365 static void iscsi_readcapacity_sync(IscsiLun *iscsilun, Error **errp)
1366 {
1367     struct scsi_task *task = NULL;
1368     struct scsi_readcapacity10 *rc10 = NULL;
1369     struct scsi_readcapacity16 *rc16 = NULL;
1370     int retries = ISCSI_CMD_RETRIES;
1371 
1372     do {
1373         if (task != NULL) {
1374             scsi_free_scsi_task(task);
1375             task = NULL;
1376         }
1377 
1378         switch (iscsilun->type) {
1379         case TYPE_DISK:
1380             task = iscsi_readcapacity16_sync(iscsilun->iscsi, iscsilun->lun);
1381             if (task != NULL && task->status == SCSI_STATUS_GOOD) {
1382                 rc16 = scsi_datain_unmarshall(task);
1383                 if (rc16 == NULL) {
1384                     error_setg(errp, "iSCSI: Failed to unmarshall readcapacity16 data.");
1385                 } else {
1386                     iscsilun->block_size = rc16->block_length;
1387                     iscsilun->num_blocks = rc16->returned_lba + 1;
1388                     iscsilun->lbpme = !!rc16->lbpme;
1389                     iscsilun->lbprz = !!rc16->lbprz;
1390                     iscsilun->use_16_for_rw = (rc16->returned_lba > 0xffffffff);
1391                 }
1392                 break;
1393             }
1394             if (task != NULL && task->status == SCSI_STATUS_CHECK_CONDITION
1395                 && task->sense.key == SCSI_SENSE_UNIT_ATTENTION) {
1396                 break;
1397             }
1398             /* Fall through and try READ CAPACITY(10) instead.  */
1399         case TYPE_ROM:
1400             task = iscsi_readcapacity10_sync(iscsilun->iscsi, iscsilun->lun, 0, 0);
1401             if (task != NULL && task->status == SCSI_STATUS_GOOD) {
1402                 rc10 = scsi_datain_unmarshall(task);
1403                 if (rc10 == NULL) {
1404                     error_setg(errp, "iSCSI: Failed to unmarshall readcapacity10 data.");
1405                 } else {
1406                     iscsilun->block_size = rc10->block_size;
1407                     if (rc10->lba == 0) {
1408                         /* blank disk loaded */
1409                         iscsilun->num_blocks = 0;
1410                     } else {
1411                         iscsilun->num_blocks = rc10->lba + 1;
1412                     }
1413                 }
1414             }
1415             break;
1416         default:
1417             return;
1418         }
1419     } while (task != NULL && task->status == SCSI_STATUS_CHECK_CONDITION
1420              && task->sense.key == SCSI_SENSE_UNIT_ATTENTION
1421              && retries-- > 0);
1422 
1423     if (task == NULL || task->status != SCSI_STATUS_GOOD) {
1424         error_setg(errp, "iSCSI: failed to send readcapacity10/16 command");
1425     } else if (!iscsilun->block_size ||
1426                iscsilun->block_size % BDRV_SECTOR_SIZE) {
1427         error_setg(errp, "iSCSI: the target returned an invalid "
1428                    "block size of %d.", iscsilun->block_size);
1429     }
1430     if (task) {
1431         scsi_free_scsi_task(task);
1432     }
1433 }
1434 
1435 /* TODO Convert to fine grained options */
1436 static QemuOptsList runtime_opts = {
1437     .name = "iscsi",
1438     .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
1439     .desc = {
1440         {
1441             .name = "filename",
1442             .type = QEMU_OPT_STRING,
1443             .help = "URL to the iscsi image",
1444         },
1445         { /* end of list */ }
1446     },
1447 };
1448 
1449 static struct scsi_task *iscsi_do_inquiry(struct iscsi_context *iscsi, int lun,
1450                                           int evpd, int pc, void **inq, Error **errp)
1451 {
1452     int full_size;
1453     struct scsi_task *task = NULL;
1454     task = iscsi_inquiry_sync(iscsi, lun, evpd, pc, 64);
1455     if (task == NULL || task->status != SCSI_STATUS_GOOD) {
1456         goto fail;
1457     }
1458     full_size = scsi_datain_getfullsize(task);
1459     if (full_size > task->datain.size) {
1460         scsi_free_scsi_task(task);
1461 
1462         /* we need more data for the full list */
1463         task = iscsi_inquiry_sync(iscsi, lun, evpd, pc, full_size);
1464         if (task == NULL || task->status != SCSI_STATUS_GOOD) {
1465             goto fail;
1466         }
1467     }
1468 
1469     *inq = scsi_datain_unmarshall(task);
1470     if (*inq == NULL) {
1471         error_setg(errp, "iSCSI: failed to unmarshall inquiry datain blob");
1472         goto fail_with_err;
1473     }
1474 
1475     return task;
1476 
1477 fail:
1478     error_setg(errp, "iSCSI: Inquiry command failed : %s",
1479                iscsi_get_error(iscsi));
1480 fail_with_err:
1481     if (task != NULL) {
1482         scsi_free_scsi_task(task);
1483     }
1484     return NULL;
1485 }
1486 
1487 static void iscsi_detach_aio_context(BlockDriverState *bs)
1488 {
1489     IscsiLun *iscsilun = bs->opaque;
1490 
1491     aio_set_fd_handler(iscsilun->aio_context, iscsi_get_fd(iscsilun->iscsi),
1492                        false, NULL, NULL, NULL);
1493     iscsilun->events = 0;
1494 
1495     if (iscsilun->nop_timer) {
1496         timer_del(iscsilun->nop_timer);
1497         timer_free(iscsilun->nop_timer);
1498         iscsilun->nop_timer = NULL;
1499     }
1500     if (iscsilun->event_timer) {
1501         timer_del(iscsilun->event_timer);
1502         timer_free(iscsilun->event_timer);
1503         iscsilun->event_timer = NULL;
1504     }
1505 }
1506 
1507 static void iscsi_attach_aio_context(BlockDriverState *bs,
1508                                      AioContext *new_context)
1509 {
1510     IscsiLun *iscsilun = bs->opaque;
1511 
1512     iscsilun->aio_context = new_context;
1513     iscsi_set_events(iscsilun);
1514 
1515     /* Set up a timer for sending out iSCSI NOPs */
1516     iscsilun->nop_timer = aio_timer_new(iscsilun->aio_context,
1517                                         QEMU_CLOCK_REALTIME, SCALE_MS,
1518                                         iscsi_nop_timed_event, iscsilun);
1519     timer_mod(iscsilun->nop_timer,
1520               qemu_clock_get_ms(QEMU_CLOCK_REALTIME) + NOP_INTERVAL);
1521 
1522     /* Set up a timer for periodic calls to iscsi_set_events and to
1523      * scan for command timeout */
1524     iscsilun->event_timer = aio_timer_new(iscsilun->aio_context,
1525                                           QEMU_CLOCK_REALTIME, SCALE_MS,
1526                                           iscsi_timed_check_events, iscsilun);
1527     timer_mod(iscsilun->event_timer,
1528               qemu_clock_get_ms(QEMU_CLOCK_REALTIME) + EVENT_INTERVAL);
1529 }
1530 
1531 static void iscsi_modesense_sync(IscsiLun *iscsilun)
1532 {
1533     struct scsi_task *task;
1534     struct scsi_mode_sense *ms = NULL;
1535     iscsilun->write_protected = false;
1536     iscsilun->dpofua = false;
1537 
1538     task = iscsi_modesense6_sync(iscsilun->iscsi, iscsilun->lun,
1539                                  1, SCSI_MODESENSE_PC_CURRENT,
1540                                  0x3F, 0, 255);
1541     if (task == NULL) {
1542         error_report("iSCSI: Failed to send MODE_SENSE(6) command: %s",
1543                      iscsi_get_error(iscsilun->iscsi));
1544         goto out;
1545     }
1546 
1547     if (task->status != SCSI_STATUS_GOOD) {
1548         error_report("iSCSI: Failed MODE_SENSE(6), LUN assumed writable");
1549         goto out;
1550     }
1551     ms = scsi_datain_unmarshall(task);
1552     if (!ms) {
1553         error_report("iSCSI: Failed to unmarshall MODE_SENSE(6) data: %s",
1554                      iscsi_get_error(iscsilun->iscsi));
1555         goto out;
1556     }
1557     iscsilun->write_protected = ms->device_specific_parameter & 0x80;
1558     iscsilun->dpofua          = ms->device_specific_parameter & 0x10;
1559 
1560 out:
1561     if (task) {
1562         scsi_free_scsi_task(task);
1563     }
1564 }
1565 
1566 /*
1567  * We support iscsi url's on the form
1568  * iscsi://[<username>%<password>@]<host>[:<port>]/<targetname>/<lun>
1569  */
1570 static int iscsi_open(BlockDriverState *bs, QDict *options, int flags,
1571                       Error **errp)
1572 {
1573     IscsiLun *iscsilun = bs->opaque;
1574     struct iscsi_context *iscsi = NULL;
1575     struct iscsi_url *iscsi_url = NULL;
1576     struct scsi_task *task = NULL;
1577     struct scsi_inquiry_standard *inq = NULL;
1578     struct scsi_inquiry_supported_pages *inq_vpd;
1579     char *initiator_name = NULL;
1580     QemuOpts *opts;
1581     Error *local_err = NULL;
1582     const char *filename;
1583     int i, ret = 0, timeout = 0;
1584 
1585     opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
1586     qemu_opts_absorb_qdict(opts, options, &local_err);
1587     if (local_err) {
1588         error_propagate(errp, local_err);
1589         ret = -EINVAL;
1590         goto out;
1591     }
1592 
1593     filename = qemu_opt_get(opts, "filename");
1594 
1595     iscsi_url = iscsi_parse_full_url(iscsi, filename);
1596     if (iscsi_url == NULL) {
1597         error_setg(errp, "Failed to parse URL : %s", filename);
1598         ret = -EINVAL;
1599         goto out;
1600     }
1601 
1602     memset(iscsilun, 0, sizeof(IscsiLun));
1603 
1604     initiator_name = parse_initiator_name(iscsi_url->target);
1605 
1606     iscsi = iscsi_create_context(initiator_name);
1607     if (iscsi == NULL) {
1608         error_setg(errp, "iSCSI: Failed to create iSCSI context.");
1609         ret = -ENOMEM;
1610         goto out;
1611     }
1612 
1613     if (iscsi_set_targetname(iscsi, iscsi_url->target)) {
1614         error_setg(errp, "iSCSI: Failed to set target name.");
1615         ret = -EINVAL;
1616         goto out;
1617     }
1618 
1619     if (iscsi_url->user[0] != '\0') {
1620         ret = iscsi_set_initiator_username_pwd(iscsi, iscsi_url->user,
1621                                               iscsi_url->passwd);
1622         if (ret != 0) {
1623             error_setg(errp, "Failed to set initiator username and password");
1624             ret = -EINVAL;
1625             goto out;
1626         }
1627     }
1628 
1629     /* check if we got CHAP username/password via the options */
1630     parse_chap(iscsi, iscsi_url->target, &local_err);
1631     if (local_err != NULL) {
1632         error_propagate(errp, local_err);
1633         ret = -EINVAL;
1634         goto out;
1635     }
1636 
1637     if (iscsi_set_session_type(iscsi, ISCSI_SESSION_NORMAL) != 0) {
1638         error_setg(errp, "iSCSI: Failed to set session type to normal.");
1639         ret = -EINVAL;
1640         goto out;
1641     }
1642 
1643     iscsi_set_header_digest(iscsi, ISCSI_HEADER_DIGEST_NONE_CRC32C);
1644 
1645     /* check if we got HEADER_DIGEST via the options */
1646     parse_header_digest(iscsi, iscsi_url->target, &local_err);
1647     if (local_err != NULL) {
1648         error_propagate(errp, local_err);
1649         ret = -EINVAL;
1650         goto out;
1651     }
1652 
1653     /* timeout handling is broken in libiscsi before 1.15.0 */
1654     timeout = parse_timeout(iscsi_url->target);
1655 #if defined(LIBISCSI_API_VERSION) && LIBISCSI_API_VERSION >= 20150621
1656     iscsi_set_timeout(iscsi, timeout);
1657 #else
1658     if (timeout) {
1659         error_report("iSCSI: ignoring timeout value for libiscsi <1.15.0");
1660     }
1661 #endif
1662 
1663     if (iscsi_full_connect_sync(iscsi, iscsi_url->portal, iscsi_url->lun) != 0) {
1664         error_setg(errp, "iSCSI: Failed to connect to LUN : %s",
1665             iscsi_get_error(iscsi));
1666         ret = -EINVAL;
1667         goto out;
1668     }
1669 
1670     iscsilun->iscsi = iscsi;
1671     iscsilun->aio_context = bdrv_get_aio_context(bs);
1672     iscsilun->lun   = iscsi_url->lun;
1673     iscsilun->has_write_same = true;
1674 
1675     task = iscsi_do_inquiry(iscsilun->iscsi, iscsilun->lun, 0, 0,
1676                             (void **) &inq, errp);
1677     if (task == NULL) {
1678         ret = -EINVAL;
1679         goto out;
1680     }
1681     iscsilun->type = inq->periperal_device_type;
1682     scsi_free_scsi_task(task);
1683     task = NULL;
1684 
1685     iscsi_modesense_sync(iscsilun);
1686     if (iscsilun->dpofua) {
1687         bs->supported_write_flags = BDRV_REQ_FUA;
1688     }
1689     bs->supported_zero_flags = BDRV_REQ_MAY_UNMAP;
1690 
1691     /* Check the write protect flag of the LUN if we want to write */
1692     if (iscsilun->type == TYPE_DISK && (flags & BDRV_O_RDWR) &&
1693         iscsilun->write_protected) {
1694         error_setg(errp, "Cannot open a write protected LUN as read-write");
1695         ret = -EACCES;
1696         goto out;
1697     }
1698 
1699     iscsi_readcapacity_sync(iscsilun, &local_err);
1700     if (local_err != NULL) {
1701         error_propagate(errp, local_err);
1702         ret = -EINVAL;
1703         goto out;
1704     }
1705     bs->total_sectors = sector_lun2qemu(iscsilun->num_blocks, iscsilun);
1706 
1707     /* We don't have any emulation for devices other than disks and CD-ROMs, so
1708      * this must be sg ioctl compatible. We force it to be sg, otherwise qemu
1709      * will try to read from the device to guess the image format.
1710      */
1711     if (iscsilun->type != TYPE_DISK && iscsilun->type != TYPE_ROM) {
1712         bs->sg = true;
1713     }
1714 
1715     task = iscsi_do_inquiry(iscsilun->iscsi, iscsilun->lun, 1,
1716                             SCSI_INQUIRY_PAGECODE_SUPPORTED_VPD_PAGES,
1717                             (void **) &inq_vpd, errp);
1718     if (task == NULL) {
1719         ret = -EINVAL;
1720         goto out;
1721     }
1722     for (i = 0; i < inq_vpd->num_pages; i++) {
1723         struct scsi_task *inq_task;
1724         struct scsi_inquiry_logical_block_provisioning *inq_lbp;
1725         struct scsi_inquiry_block_limits *inq_bl;
1726         switch (inq_vpd->pages[i]) {
1727         case SCSI_INQUIRY_PAGECODE_LOGICAL_BLOCK_PROVISIONING:
1728             inq_task = iscsi_do_inquiry(iscsilun->iscsi, iscsilun->lun, 1,
1729                                         SCSI_INQUIRY_PAGECODE_LOGICAL_BLOCK_PROVISIONING,
1730                                         (void **) &inq_lbp, errp);
1731             if (inq_task == NULL) {
1732                 ret = -EINVAL;
1733                 goto out;
1734             }
1735             memcpy(&iscsilun->lbp, inq_lbp,
1736                    sizeof(struct scsi_inquiry_logical_block_provisioning));
1737             scsi_free_scsi_task(inq_task);
1738             break;
1739         case SCSI_INQUIRY_PAGECODE_BLOCK_LIMITS:
1740             inq_task = iscsi_do_inquiry(iscsilun->iscsi, iscsilun->lun, 1,
1741                                     SCSI_INQUIRY_PAGECODE_BLOCK_LIMITS,
1742                                     (void **) &inq_bl, errp);
1743             if (inq_task == NULL) {
1744                 ret = -EINVAL;
1745                 goto out;
1746             }
1747             memcpy(&iscsilun->bl, inq_bl,
1748                    sizeof(struct scsi_inquiry_block_limits));
1749             scsi_free_scsi_task(inq_task);
1750             break;
1751         default:
1752             break;
1753         }
1754     }
1755     scsi_free_scsi_task(task);
1756     task = NULL;
1757 
1758     iscsi_attach_aio_context(bs, iscsilun->aio_context);
1759 
1760     /* Guess the internal cluster (page) size of the iscsi target by the means
1761      * of opt_unmap_gran. Transfer the unmap granularity only if it has a
1762      * reasonable size */
1763     if (iscsilun->bl.opt_unmap_gran * iscsilun->block_size >= 4 * 1024 &&
1764         iscsilun->bl.opt_unmap_gran * iscsilun->block_size <= 16 * 1024 * 1024) {
1765         iscsilun->cluster_sectors = (iscsilun->bl.opt_unmap_gran *
1766                                      iscsilun->block_size) >> BDRV_SECTOR_BITS;
1767         if (iscsilun->lbprz) {
1768             ret = iscsi_allocmap_init(iscsilun, bs->open_flags);
1769         }
1770     }
1771 
1772 out:
1773     qemu_opts_del(opts);
1774     g_free(initiator_name);
1775     if (iscsi_url != NULL) {
1776         iscsi_destroy_url(iscsi_url);
1777     }
1778     if (task != NULL) {
1779         scsi_free_scsi_task(task);
1780     }
1781 
1782     if (ret) {
1783         if (iscsi != NULL) {
1784             if (iscsi_is_logged_in(iscsi)) {
1785                 iscsi_logout_sync(iscsi);
1786             }
1787             iscsi_destroy_context(iscsi);
1788         }
1789         memset(iscsilun, 0, sizeof(IscsiLun));
1790     }
1791     return ret;
1792 }
1793 
1794 static void iscsi_close(BlockDriverState *bs)
1795 {
1796     IscsiLun *iscsilun = bs->opaque;
1797     struct iscsi_context *iscsi = iscsilun->iscsi;
1798 
1799     iscsi_detach_aio_context(bs);
1800     if (iscsi_is_logged_in(iscsi)) {
1801         iscsi_logout_sync(iscsi);
1802     }
1803     iscsi_destroy_context(iscsi);
1804     g_free(iscsilun->zeroblock);
1805     iscsi_allocmap_free(iscsilun);
1806     memset(iscsilun, 0, sizeof(IscsiLun));
1807 }
1808 
1809 static void iscsi_refresh_limits(BlockDriverState *bs, Error **errp)
1810 {
1811     /* We don't actually refresh here, but just return data queried in
1812      * iscsi_open(): iscsi targets don't change their limits. */
1813 
1814     IscsiLun *iscsilun = bs->opaque;
1815     uint64_t max_xfer_len = iscsilun->use_16_for_rw ? 0xffffffff : 0xffff;
1816 
1817     bs->bl.request_alignment = iscsilun->block_size;
1818 
1819     if (iscsilun->bl.max_xfer_len) {
1820         max_xfer_len = MIN(max_xfer_len, iscsilun->bl.max_xfer_len);
1821     }
1822 
1823     if (max_xfer_len * iscsilun->block_size < INT_MAX) {
1824         bs->bl.max_transfer = max_xfer_len * iscsilun->block_size;
1825     }
1826 
1827     if (iscsilun->lbp.lbpu) {
1828         if (iscsilun->bl.max_unmap < 0xffffffff / iscsilun->block_size) {
1829             bs->bl.max_pdiscard =
1830                 iscsilun->bl.max_unmap * iscsilun->block_size;
1831         }
1832         bs->bl.pdiscard_alignment =
1833             iscsilun->bl.opt_unmap_gran * iscsilun->block_size;
1834     } else {
1835         bs->bl.pdiscard_alignment = iscsilun->block_size;
1836     }
1837 
1838     if (iscsilun->bl.max_ws_len < 0xffffffff / iscsilun->block_size) {
1839         bs->bl.max_pwrite_zeroes =
1840             iscsilun->bl.max_ws_len * iscsilun->block_size;
1841     }
1842     if (iscsilun->lbp.lbpws) {
1843         bs->bl.pwrite_zeroes_alignment =
1844             iscsilun->bl.opt_unmap_gran * iscsilun->block_size;
1845     } else {
1846         bs->bl.pwrite_zeroes_alignment = iscsilun->block_size;
1847     }
1848     if (iscsilun->bl.opt_xfer_len &&
1849         iscsilun->bl.opt_xfer_len < INT_MAX / iscsilun->block_size) {
1850         bs->bl.opt_transfer = pow2floor(iscsilun->bl.opt_xfer_len *
1851                                         iscsilun->block_size);
1852     }
1853 }
1854 
1855 /* Note that this will not re-establish a connection with an iSCSI target - it
1856  * is effectively a NOP.  */
1857 static int iscsi_reopen_prepare(BDRVReopenState *state,
1858                                 BlockReopenQueue *queue, Error **errp)
1859 {
1860     IscsiLun *iscsilun = state->bs->opaque;
1861 
1862     if (state->flags & BDRV_O_RDWR && iscsilun->write_protected) {
1863         error_setg(errp, "Cannot open a write protected LUN as read-write");
1864         return -EACCES;
1865     }
1866     return 0;
1867 }
1868 
1869 static void iscsi_reopen_commit(BDRVReopenState *reopen_state)
1870 {
1871     IscsiLun *iscsilun = reopen_state->bs->opaque;
1872 
1873     /* the cache.direct status might have changed */
1874     if (iscsilun->allocmap != NULL) {
1875         iscsi_allocmap_init(iscsilun, reopen_state->flags);
1876     }
1877 }
1878 
1879 static int iscsi_truncate(BlockDriverState *bs, int64_t offset)
1880 {
1881     IscsiLun *iscsilun = bs->opaque;
1882     Error *local_err = NULL;
1883 
1884     if (iscsilun->type != TYPE_DISK) {
1885         return -ENOTSUP;
1886     }
1887 
1888     iscsi_readcapacity_sync(iscsilun, &local_err);
1889     if (local_err != NULL) {
1890         error_free(local_err);
1891         return -EIO;
1892     }
1893 
1894     if (offset > iscsi_getlength(bs)) {
1895         return -EINVAL;
1896     }
1897 
1898     if (iscsilun->allocmap != NULL) {
1899         iscsi_allocmap_init(iscsilun, bs->open_flags);
1900     }
1901 
1902     return 0;
1903 }
1904 
1905 static int iscsi_create(const char *filename, QemuOpts *opts, Error **errp)
1906 {
1907     int ret = 0;
1908     int64_t total_size = 0;
1909     BlockDriverState *bs;
1910     IscsiLun *iscsilun = NULL;
1911     QDict *bs_options;
1912 
1913     bs = bdrv_new();
1914 
1915     /* Read out options */
1916     total_size = DIV_ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0),
1917                               BDRV_SECTOR_SIZE);
1918     bs->opaque = g_new0(struct IscsiLun, 1);
1919     iscsilun = bs->opaque;
1920 
1921     bs_options = qdict_new();
1922     qdict_put(bs_options, "filename", qstring_from_str(filename));
1923     ret = iscsi_open(bs, bs_options, 0, NULL);
1924     QDECREF(bs_options);
1925 
1926     if (ret != 0) {
1927         goto out;
1928     }
1929     iscsi_detach_aio_context(bs);
1930     if (iscsilun->type != TYPE_DISK) {
1931         ret = -ENODEV;
1932         goto out;
1933     }
1934     if (bs->total_sectors < total_size) {
1935         ret = -ENOSPC;
1936         goto out;
1937     }
1938 
1939     ret = 0;
1940 out:
1941     if (iscsilun->iscsi != NULL) {
1942         iscsi_destroy_context(iscsilun->iscsi);
1943     }
1944     g_free(bs->opaque);
1945     bs->opaque = NULL;
1946     bdrv_unref(bs);
1947     return ret;
1948 }
1949 
1950 static int iscsi_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
1951 {
1952     IscsiLun *iscsilun = bs->opaque;
1953     bdi->unallocated_blocks_are_zero = iscsilun->lbprz;
1954     bdi->can_write_zeroes_with_unmap = iscsilun->lbprz && iscsilun->lbp.lbpws;
1955     bdi->cluster_size = iscsilun->cluster_sectors * BDRV_SECTOR_SIZE;
1956     return 0;
1957 }
1958 
1959 static void iscsi_invalidate_cache(BlockDriverState *bs,
1960                                    Error **errp)
1961 {
1962     IscsiLun *iscsilun = bs->opaque;
1963     iscsi_allocmap_invalidate(iscsilun);
1964 }
1965 
1966 static QemuOptsList iscsi_create_opts = {
1967     .name = "iscsi-create-opts",
1968     .head = QTAILQ_HEAD_INITIALIZER(iscsi_create_opts.head),
1969     .desc = {
1970         {
1971             .name = BLOCK_OPT_SIZE,
1972             .type = QEMU_OPT_SIZE,
1973             .help = "Virtual disk size"
1974         },
1975         { /* end of list */ }
1976     }
1977 };
1978 
1979 static BlockDriver bdrv_iscsi = {
1980     .format_name     = "iscsi",
1981     .protocol_name   = "iscsi",
1982 
1983     .instance_size   = sizeof(IscsiLun),
1984     .bdrv_needs_filename = true,
1985     .bdrv_file_open  = iscsi_open,
1986     .bdrv_close      = iscsi_close,
1987     .bdrv_create     = iscsi_create,
1988     .create_opts     = &iscsi_create_opts,
1989     .bdrv_reopen_prepare   = iscsi_reopen_prepare,
1990     .bdrv_reopen_commit    = iscsi_reopen_commit,
1991     .bdrv_invalidate_cache = iscsi_invalidate_cache,
1992 
1993     .bdrv_getlength  = iscsi_getlength,
1994     .bdrv_get_info   = iscsi_get_info,
1995     .bdrv_truncate   = iscsi_truncate,
1996     .bdrv_refresh_limits = iscsi_refresh_limits,
1997 
1998     .bdrv_co_get_block_status = iscsi_co_get_block_status,
1999     .bdrv_co_pdiscard      = iscsi_co_pdiscard,
2000     .bdrv_co_pwrite_zeroes = iscsi_co_pwrite_zeroes,
2001     .bdrv_co_readv         = iscsi_co_readv,
2002     .bdrv_co_writev_flags  = iscsi_co_writev_flags,
2003     .bdrv_co_flush_to_disk = iscsi_co_flush,
2004 
2005 #ifdef __linux__
2006     .bdrv_aio_ioctl   = iscsi_aio_ioctl,
2007 #endif
2008 
2009     .bdrv_detach_aio_context = iscsi_detach_aio_context,
2010     .bdrv_attach_aio_context = iscsi_attach_aio_context,
2011 };
2012 
2013 static void iscsi_block_init(void)
2014 {
2015     bdrv_register(&bdrv_iscsi);
2016 }
2017 
2018 block_init(iscsi_block_init);
2019