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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * SCSI Block Commands (SBC) parsing and emulation.
4 *
5 * (c) Copyright 2002-2013 Datera, Inc.
6 *
7 * Nicholas A. Bellinger <nab@kernel.org>
8 */
9
10#include <linux/kernel.h>
11#include <linux/module.h>
12#include <linux/ratelimit.h>
13#include <linux/crc-t10dif.h>
14#include <linux/t10-pi.h>
15#include <asm/unaligned.h>
16#include <scsi/scsi_proto.h>
17#include <scsi/scsi_tcq.h>
18
19#include <target/target_core_base.h>
20#include <target/target_core_backend.h>
21#include <target/target_core_fabric.h>
22
23#include "target_core_internal.h"
24#include "target_core_ua.h"
25#include "target_core_alua.h"
26
27static sense_reason_t
28sbc_check_prot(struct se_device *, struct se_cmd *, unsigned char, u32, bool);
29static sense_reason_t sbc_execute_unmap(struct se_cmd *cmd);
30
31static sense_reason_t
32sbc_emulate_readcapacity(struct se_cmd *cmd)
33{
34 struct se_device *dev = cmd->se_dev;
35 unsigned char *cdb = cmd->t_task_cdb;
36 unsigned long long blocks_long = dev->transport->get_blocks(dev);
37 unsigned char *rbuf;
38 unsigned char buf[8];
39 u32 blocks;
40
41 /*
42 * SBC-2 says:
43 * If the PMI bit is set to zero and the LOGICAL BLOCK
44 * ADDRESS field is not set to zero, the device server shall
45 * terminate the command with CHECK CONDITION status with
46 * the sense key set to ILLEGAL REQUEST and the additional
47 * sense code set to INVALID FIELD IN CDB.
48 *
49 * In SBC-3, these fields are obsolete, but some SCSI
50 * compliance tests actually check this, so we might as well
51 * follow SBC-2.
52 */
53 if (!(cdb[8] & 1) && !!(cdb[2] | cdb[3] | cdb[4] | cdb[5]))
54 return TCM_INVALID_CDB_FIELD;
55
56 if (blocks_long >= 0x00000000ffffffff)
57 blocks = 0xffffffff;
58 else
59 blocks = (u32)blocks_long;
60
61 put_unaligned_be32(blocks, &buf[0]);
62 put_unaligned_be32(dev->dev_attrib.block_size, &buf[4]);
63
64 rbuf = transport_kmap_data_sg(cmd);
65 if (rbuf) {
66 memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length));
67 transport_kunmap_data_sg(cmd);
68 }
69
70 target_complete_cmd_with_length(cmd, SAM_STAT_GOOD, 8);
71 return 0;
72}
73
74static sense_reason_t
75sbc_emulate_readcapacity_16(struct se_cmd *cmd)
76{
77 struct se_device *dev = cmd->se_dev;
78 struct se_session *sess = cmd->se_sess;
79 int pi_prot_type = dev->dev_attrib.pi_prot_type;
80
81 unsigned char *rbuf;
82 unsigned char buf[32];
83 unsigned long long blocks = dev->transport->get_blocks(dev);
84
85 memset(buf, 0, sizeof(buf));
86 put_unaligned_be64(blocks, &buf[0]);
87 put_unaligned_be32(dev->dev_attrib.block_size, &buf[8]);
88 /*
89 * Set P_TYPE and PROT_EN bits for DIF support
90 */
91 if (sess->sup_prot_ops & (TARGET_PROT_DIN_PASS | TARGET_PROT_DOUT_PASS)) {
92 /*
93 * Only override a device's pi_prot_type if no T10-PI is
94 * available, and sess_prot_type has been explicitly enabled.
95 */
96 if (!pi_prot_type)
97 pi_prot_type = sess->sess_prot_type;
98
99 if (pi_prot_type)
100 buf[12] = (pi_prot_type - 1) << 1 | 0x1;
101 }
102
103 if (dev->transport->get_lbppbe)
104 buf[13] = dev->transport->get_lbppbe(dev) & 0x0f;
105
106 if (dev->transport->get_alignment_offset_lbas) {
107 u16 lalba = dev->transport->get_alignment_offset_lbas(dev);
108
109 put_unaligned_be16(lalba, &buf[14]);
110 }
111
112 /*
113 * Set Thin Provisioning Enable bit following sbc3r22 in section
114 * READ CAPACITY (16) byte 14 if emulate_tpu or emulate_tpws is enabled.
115 */
116 if (dev->dev_attrib.emulate_tpu || dev->dev_attrib.emulate_tpws) {
117 buf[14] |= 0x80;
118
119 /*
120 * LBPRZ signifies that zeroes will be read back from an LBA after
121 * an UNMAP or WRITE SAME w/ unmap bit (sbc3r36 5.16.2)
122 */
123 if (dev->dev_attrib.unmap_zeroes_data)
124 buf[14] |= 0x40;
125 }
126
127 rbuf = transport_kmap_data_sg(cmd);
128 if (rbuf) {
129 memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length));
130 transport_kunmap_data_sg(cmd);
131 }
132
133 target_complete_cmd_with_length(cmd, SAM_STAT_GOOD, 32);
134 return 0;
135}
136
137static sense_reason_t
138sbc_emulate_startstop(struct se_cmd *cmd)
139{
140 unsigned char *cdb = cmd->t_task_cdb;
141
142 /*
143 * See sbc3r36 section 5.25
144 * Immediate bit should be set since there is nothing to complete
145 * POWER CONDITION MODIFIER 0h
146 */
147 if (!(cdb[1] & 1) || cdb[2] || cdb[3])
148 return TCM_INVALID_CDB_FIELD;
149
150 /*
151 * See sbc3r36 section 5.25
152 * POWER CONDITION 0h START_VALID - process START and LOEJ
153 */
154 if (cdb[4] >> 4 & 0xf)
155 return TCM_INVALID_CDB_FIELD;
156
157 /*
158 * See sbc3r36 section 5.25
159 * LOEJ 0h - nothing to load or unload
160 * START 1h - we are ready
161 */
162 if (!(cdb[4] & 1) || (cdb[4] & 2) || (cdb[4] & 4))
163 return TCM_INVALID_CDB_FIELD;
164
165 target_complete_cmd(cmd, SAM_STAT_GOOD);
166 return 0;
167}
168
169sector_t sbc_get_write_same_sectors(struct se_cmd *cmd)
170{
171 u32 num_blocks;
172
173 if (cmd->t_task_cdb[0] == WRITE_SAME)
174 num_blocks = get_unaligned_be16(&cmd->t_task_cdb[7]);
175 else if (cmd->t_task_cdb[0] == WRITE_SAME_16)
176 num_blocks = get_unaligned_be32(&cmd->t_task_cdb[10]);
177 else /* WRITE_SAME_32 via VARIABLE_LENGTH_CMD */
178 num_blocks = get_unaligned_be32(&cmd->t_task_cdb[28]);
179
180 /*
181 * Use the explicit range when non zero is supplied, otherwise calculate
182 * the remaining range based on ->get_blocks() - starting LBA.
183 */
184 if (num_blocks)
185 return num_blocks;
186
187 return cmd->se_dev->transport->get_blocks(cmd->se_dev) -
188 cmd->t_task_lba + 1;
189}
190EXPORT_SYMBOL(sbc_get_write_same_sectors);
191
192static sense_reason_t
193sbc_execute_write_same_unmap(struct se_cmd *cmd)
194{
195 struct sbc_ops *ops = cmd->protocol_data;
196 sector_t nolb = sbc_get_write_same_sectors(cmd);
197 sense_reason_t ret;
198
199 if (nolb) {
200 ret = ops->execute_unmap(cmd, cmd->t_task_lba, nolb);
201 if (ret)
202 return ret;
203 }
204
205 target_complete_cmd(cmd, SAM_STAT_GOOD);
206 return 0;
207}
208
209static sense_reason_t
210sbc_emulate_noop(struct se_cmd *cmd)
211{
212 target_complete_cmd(cmd, SAM_STAT_GOOD);
213 return 0;
214}
215
216static inline u32 sbc_get_size(struct se_cmd *cmd, u32 sectors)
217{
218 return cmd->se_dev->dev_attrib.block_size * sectors;
219}
220
221static inline u32 transport_get_sectors_6(unsigned char *cdb)
222{
223 /*
224 * Use 8-bit sector value. SBC-3 says:
225 *
226 * A TRANSFER LENGTH field set to zero specifies that 256
227 * logical blocks shall be written. Any other value
228 * specifies the number of logical blocks that shall be
229 * written.
230 */
231 return cdb[4] ? : 256;
232}
233
234static inline u32 transport_get_sectors_10(unsigned char *cdb)
235{
236 return get_unaligned_be16(&cdb[7]);
237}
238
239static inline u32 transport_get_sectors_12(unsigned char *cdb)
240{
241 return get_unaligned_be32(&cdb[6]);
242}
243
244static inline u32 transport_get_sectors_16(unsigned char *cdb)
245{
246 return get_unaligned_be32(&cdb[10]);
247}
248
249/*
250 * Used for VARIABLE_LENGTH_CDB WRITE_32 and READ_32 variants
251 */
252static inline u32 transport_get_sectors_32(unsigned char *cdb)
253{
254 return get_unaligned_be32(&cdb[28]);
255
256}
257
258static inline u32 transport_lba_21(unsigned char *cdb)
259{
260 return get_unaligned_be24(&cdb[1]) & 0x1fffff;
261}
262
263static inline u32 transport_lba_32(unsigned char *cdb)
264{
265 return get_unaligned_be32(&cdb[2]);
266}
267
268static inline unsigned long long transport_lba_64(unsigned char *cdb)
269{
270 return get_unaligned_be64(&cdb[2]);
271}
272
273static sense_reason_t
274sbc_setup_write_same(struct se_cmd *cmd, unsigned char flags, struct sbc_ops *ops)
275{
276 struct se_device *dev = cmd->se_dev;
277 sector_t end_lba = dev->transport->get_blocks(dev) + 1;
278 unsigned int sectors = sbc_get_write_same_sectors(cmd);
279 sense_reason_t ret;
280
281 if ((flags & 0x04) || (flags & 0x02)) {
282 pr_err("WRITE_SAME PBDATA and LBDATA"
283 " bits not supported for Block Discard"
284 " Emulation\n");
285 return TCM_UNSUPPORTED_SCSI_OPCODE;
286 }
287 if (sectors > cmd->se_dev->dev_attrib.max_write_same_len) {
288 pr_warn("WRITE_SAME sectors: %u exceeds max_write_same_len: %u\n",
289 sectors, cmd->se_dev->dev_attrib.max_write_same_len);
290 return TCM_INVALID_CDB_FIELD;
291 }
292 /*
293 * Sanity check for LBA wrap and request past end of device.
294 */
295 if (((cmd->t_task_lba + sectors) < cmd->t_task_lba) ||
296 ((cmd->t_task_lba + sectors) > end_lba)) {
297 pr_err("WRITE_SAME exceeds last lba %llu (lba %llu, sectors %u)\n",
298 (unsigned long long)end_lba, cmd->t_task_lba, sectors);
299 return TCM_ADDRESS_OUT_OF_RANGE;
300 }
301
302 /* We always have ANC_SUP == 0 so setting ANCHOR is always an error */
303 if (flags & 0x10) {
304 pr_warn("WRITE SAME with ANCHOR not supported\n");
305 return TCM_INVALID_CDB_FIELD;
306 }
307
308 if (flags & 0x01) {
309 pr_warn("WRITE SAME with NDOB not supported\n");
310 return TCM_INVALID_CDB_FIELD;
311 }
312
313 /*
314 * Special case for WRITE_SAME w/ UNMAP=1 that ends up getting
315 * translated into block discard requests within backend code.
316 */
317 if (flags & 0x08) {
318 if (!ops->execute_unmap)
319 return TCM_UNSUPPORTED_SCSI_OPCODE;
320
321 if (!dev->dev_attrib.emulate_tpws) {
322 pr_err("Got WRITE_SAME w/ UNMAP=1, but backend device"
323 " has emulate_tpws disabled\n");
324 return TCM_UNSUPPORTED_SCSI_OPCODE;
325 }
326 cmd->execute_cmd = sbc_execute_write_same_unmap;
327 return 0;
328 }
329 if (!ops->execute_write_same)
330 return TCM_UNSUPPORTED_SCSI_OPCODE;
331
332 ret = sbc_check_prot(dev, cmd, flags >> 5, sectors, true);
333 if (ret)
334 return ret;
335
336 cmd->execute_cmd = ops->execute_write_same;
337 return 0;
338}
339
340static sense_reason_t
341sbc_execute_rw(struct se_cmd *cmd)
342{
343 struct sbc_ops *ops = cmd->protocol_data;
344
345 return ops->execute_rw(cmd, cmd->t_data_sg, cmd->t_data_nents,
346 cmd->data_direction);
347}
348
349static sense_reason_t compare_and_write_post(struct se_cmd *cmd, bool success,
350 int *post_ret)
351{
352 struct se_device *dev = cmd->se_dev;
353 sense_reason_t ret = TCM_NO_SENSE;
354
355 spin_lock_irq(&cmd->t_state_lock);
356 if (success) {
357 *post_ret = 1;
358
359 if (cmd->scsi_status == SAM_STAT_CHECK_CONDITION)
360 ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
361 }
362 spin_unlock_irq(&cmd->t_state_lock);
363
364 /*
365 * Unlock ->caw_sem originally obtained during sbc_compare_and_write()
366 * before the original READ I/O submission.
367 */
368 up(&dev->caw_sem);
369
370 return ret;
371}
372
373/*
374 * compare @cmp_len bytes of @read_sgl with @cmp_sgl. On miscompare, fill
375 * @miscmp_off and return TCM_MISCOMPARE_VERIFY.
376 */
377static sense_reason_t
378compare_and_write_do_cmp(struct scatterlist *read_sgl, unsigned int read_nents,
379 struct scatterlist *cmp_sgl, unsigned int cmp_nents,
380 unsigned int cmp_len, unsigned int *miscmp_off)
381{
382 unsigned char *buf = NULL;
383 struct scatterlist *sg;
384 sense_reason_t ret;
385 unsigned int offset;
386 size_t rc;
387 int sg_cnt;
388
389 buf = kzalloc(cmp_len, GFP_KERNEL);
390 if (!buf) {
391 ret = TCM_OUT_OF_RESOURCES;
392 goto out;
393 }
394
395 rc = sg_copy_to_buffer(cmp_sgl, cmp_nents, buf, cmp_len);
396 if (!rc) {
397 pr_err("sg_copy_to_buffer() failed for compare_and_write\n");
398 ret = TCM_OUT_OF_RESOURCES;
399 goto out;
400 }
401 /*
402 * Compare SCSI READ payload against verify payload
403 */
404 offset = 0;
405 ret = TCM_NO_SENSE;
406 for_each_sg(read_sgl, sg, read_nents, sg_cnt) {
407 unsigned int len = min(sg->length, cmp_len);
408 unsigned char *addr = kmap_atomic(sg_page(sg));
409
410 if (memcmp(addr, buf + offset, len)) {
411 unsigned int i;
412
413 for (i = 0; i < len && addr[i] == buf[offset + i]; i++)
414 ;
415 *miscmp_off = offset + i;
416 pr_warn("Detected MISCOMPARE at offset %u\n",
417 *miscmp_off);
418 ret = TCM_MISCOMPARE_VERIFY;
419 }
420 kunmap_atomic(addr);
421 if (ret != TCM_NO_SENSE)
422 goto out;
423
424 offset += len;
425 cmp_len -= len;
426 if (!cmp_len)
427 break;
428 }
429 pr_debug("COMPARE AND WRITE read data matches compare data\n");
430out:
431 kfree(buf);
432 return ret;
433}
434
435static sense_reason_t compare_and_write_callback(struct se_cmd *cmd, bool success,
436 int *post_ret)
437{
438 struct se_device *dev = cmd->se_dev;
439 struct sg_table write_tbl = { };
440 struct scatterlist *write_sg;
441 struct sg_mapping_iter m;
442 unsigned int len;
443 unsigned int block_size = dev->dev_attrib.block_size;
444 unsigned int compare_len = (cmd->t_task_nolb * block_size);
445 unsigned int miscmp_off = 0;
446 sense_reason_t ret = TCM_NO_SENSE;
447 int i;
448
449 if (!success) {
450 /*
451 * Handle early failure in transport_generic_request_failure(),
452 * which will not have taken ->caw_sem yet..
453 */
454 if (!cmd->t_data_sg || !cmd->t_bidi_data_sg)
455 return TCM_NO_SENSE;
456
457 /*
458 * The command has been stopped or aborted so
459 * we don't have to perform the write operation.
460 */
461 WARN_ON(!(cmd->transport_state &
462 (CMD_T_ABORTED | CMD_T_STOP)));
463 goto out;
464 }
465 /*
466 * Handle special case for zero-length COMPARE_AND_WRITE
467 */
468 if (!cmd->data_length)
469 goto out;
470 /*
471 * Immediately exit + release dev->caw_sem if command has already
472 * been failed with a non-zero SCSI status.
473 */
474 if (cmd->scsi_status) {
475 pr_debug("compare_and_write_callback: non zero scsi_status:"
476 " 0x%02x\n", cmd->scsi_status);
477 *post_ret = 1;
478 if (cmd->scsi_status == SAM_STAT_CHECK_CONDITION)
479 ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
480 goto out;
481 }
482
483 ret = compare_and_write_do_cmp(cmd->t_bidi_data_sg,
484 cmd->t_bidi_data_nents,
485 cmd->t_data_sg,
486 cmd->t_data_nents,
487 compare_len,
488 &miscmp_off);
489 if (ret == TCM_MISCOMPARE_VERIFY) {
490 /*
491 * SBC-4 r15: 5.3 COMPARE AND WRITE command
492 * In the sense data (see 4.18 and SPC-5) the offset from the
493 * start of the Data-Out Buffer to the first byte of data that
494 * was not equal shall be reported in the INFORMATION field.
495 */
496 cmd->sense_info = miscmp_off;
497 goto out;
498 } else if (ret)
499 goto out;
500
501 if (sg_alloc_table(&write_tbl, cmd->t_data_nents, GFP_KERNEL) < 0) {
502 pr_err("Unable to allocate compare_and_write sg\n");
503 ret = TCM_OUT_OF_RESOURCES;
504 goto out;
505 }
506 write_sg = write_tbl.sgl;
507
508 i = 0;
509 len = compare_len;
510 sg_miter_start(&m, cmd->t_data_sg, cmd->t_data_nents, SG_MITER_TO_SG);
511 /*
512 * Currently assumes NoLB=1 and SGLs are PAGE_SIZE..
513 */
514 while (len) {
515 sg_miter_next(&m);
516
517 if (block_size < PAGE_SIZE) {
518 sg_set_page(&write_sg[i], m.page, block_size,
519 m.piter.sg->offset + block_size);
520 } else {
521 sg_miter_next(&m);
522 sg_set_page(&write_sg[i], m.page, block_size,
523 m.piter.sg->offset);
524 }
525 len -= block_size;
526 i++;
527 }
528 sg_miter_stop(&m);
529 /*
530 * Save the original SGL + nents values before updating to new
531 * assignments, to be released in transport_free_pages() ->
532 * transport_reset_sgl_orig()
533 */
534 cmd->t_data_sg_orig = cmd->t_data_sg;
535 cmd->t_data_sg = write_sg;
536 cmd->t_data_nents_orig = cmd->t_data_nents;
537 cmd->t_data_nents = 1;
538
539 cmd->sam_task_attr = TCM_HEAD_TAG;
540 cmd->transport_complete_callback = compare_and_write_post;
541 /*
542 * Now reset ->execute_cmd() to the normal sbc_execute_rw() handler
543 * for submitting the adjusted SGL to write instance user-data.
544 */
545 cmd->execute_cmd = sbc_execute_rw;
546
547 spin_lock_irq(&cmd->t_state_lock);
548 cmd->t_state = TRANSPORT_PROCESSING;
549 cmd->transport_state |= CMD_T_ACTIVE | CMD_T_SENT;
550 spin_unlock_irq(&cmd->t_state_lock);
551
552 __target_execute_cmd(cmd, false);
553
554 return ret;
555
556out:
557 /*
558 * In the MISCOMPARE or failure case, unlock ->caw_sem obtained in
559 * sbc_compare_and_write() before the original READ I/O submission.
560 */
561 up(&dev->caw_sem);
562 sg_free_table(&write_tbl);
563 return ret;
564}
565
566static sense_reason_t
567sbc_compare_and_write(struct se_cmd *cmd)
568{
569 struct sbc_ops *ops = cmd->protocol_data;
570 struct se_device *dev = cmd->se_dev;
571 sense_reason_t ret;
572 int rc;
573 /*
574 * Submit the READ first for COMPARE_AND_WRITE to perform the
575 * comparision using SGLs at cmd->t_bidi_data_sg..
576 */
577 rc = down_interruptible(&dev->caw_sem);
578 if (rc != 0) {
579 cmd->transport_complete_callback = NULL;
580 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
581 }
582 /*
583 * Reset cmd->data_length to individual block_size in order to not
584 * confuse backend drivers that depend on this value matching the
585 * size of the I/O being submitted.
586 */
587 cmd->data_length = cmd->t_task_nolb * dev->dev_attrib.block_size;
588
589 ret = ops->execute_rw(cmd, cmd->t_bidi_data_sg, cmd->t_bidi_data_nents,
590 DMA_FROM_DEVICE);
591 if (ret) {
592 cmd->transport_complete_callback = NULL;
593 up(&dev->caw_sem);
594 return ret;
595 }
596 /*
597 * Unlock of dev->caw_sem to occur in compare_and_write_callback()
598 * upon MISCOMPARE, or in compare_and_write_done() upon completion
599 * of WRITE instance user-data.
600 */
601 return TCM_NO_SENSE;
602}
603
604static int
605sbc_set_prot_op_checks(u8 protect, bool fabric_prot, enum target_prot_type prot_type,
606 bool is_write, struct se_cmd *cmd)
607{
608 if (is_write) {
609 cmd->prot_op = fabric_prot ? TARGET_PROT_DOUT_STRIP :
610 protect ? TARGET_PROT_DOUT_PASS :
611 TARGET_PROT_DOUT_INSERT;
612 switch (protect) {
613 case 0x0:
614 case 0x3:
615 cmd->prot_checks = 0;
616 break;
617 case 0x1:
618 case 0x5:
619 cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
620 if (prot_type == TARGET_DIF_TYPE1_PROT)
621 cmd->prot_checks |= TARGET_DIF_CHECK_REFTAG;
622 break;
623 case 0x2:
624 if (prot_type == TARGET_DIF_TYPE1_PROT)
625 cmd->prot_checks = TARGET_DIF_CHECK_REFTAG;
626 break;
627 case 0x4:
628 cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
629 break;
630 default:
631 pr_err("Unsupported protect field %d\n", protect);
632 return -EINVAL;
633 }
634 } else {
635 cmd->prot_op = fabric_prot ? TARGET_PROT_DIN_INSERT :
636 protect ? TARGET_PROT_DIN_PASS :
637 TARGET_PROT_DIN_STRIP;
638 switch (protect) {
639 case 0x0:
640 case 0x1:
641 case 0x5:
642 cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
643 if (prot_type == TARGET_DIF_TYPE1_PROT)
644 cmd->prot_checks |= TARGET_DIF_CHECK_REFTAG;
645 break;
646 case 0x2:
647 if (prot_type == TARGET_DIF_TYPE1_PROT)
648 cmd->prot_checks = TARGET_DIF_CHECK_REFTAG;
649 break;
650 case 0x3:
651 cmd->prot_checks = 0;
652 break;
653 case 0x4:
654 cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
655 break;
656 default:
657 pr_err("Unsupported protect field %d\n", protect);
658 return -EINVAL;
659 }
660 }
661
662 return 0;
663}
664
665static sense_reason_t
666sbc_check_prot(struct se_device *dev, struct se_cmd *cmd, unsigned char protect,
667 u32 sectors, bool is_write)
668{
669 int sp_ops = cmd->se_sess->sup_prot_ops;
670 int pi_prot_type = dev->dev_attrib.pi_prot_type;
671 bool fabric_prot = false;
672
673 if (!cmd->t_prot_sg || !cmd->t_prot_nents) {
674 if (unlikely(protect &&
675 !dev->dev_attrib.pi_prot_type && !cmd->se_sess->sess_prot_type)) {
676 pr_err("CDB contains protect bit, but device + fabric does"
677 " not advertise PROTECT=1 feature bit\n");
678 return TCM_INVALID_CDB_FIELD;
679 }
680 if (cmd->prot_pto)
681 return TCM_NO_SENSE;
682 }
683
684 switch (dev->dev_attrib.pi_prot_type) {
685 case TARGET_DIF_TYPE3_PROT:
686 cmd->reftag_seed = 0xffffffff;
687 break;
688 case TARGET_DIF_TYPE2_PROT:
689 if (protect)
690 return TCM_INVALID_CDB_FIELD;
691
692 cmd->reftag_seed = cmd->t_task_lba;
693 break;
694 case TARGET_DIF_TYPE1_PROT:
695 cmd->reftag_seed = cmd->t_task_lba;
696 break;
697 case TARGET_DIF_TYPE0_PROT:
698 /*
699 * See if the fabric supports T10-PI, and the session has been
700 * configured to allow export PROTECT=1 feature bit with backend
701 * devices that don't support T10-PI.
702 */
703 fabric_prot = is_write ?
704 !!(sp_ops & (TARGET_PROT_DOUT_PASS | TARGET_PROT_DOUT_STRIP)) :
705 !!(sp_ops & (TARGET_PROT_DIN_PASS | TARGET_PROT_DIN_INSERT));
706
707 if (fabric_prot && cmd->se_sess->sess_prot_type) {
708 pi_prot_type = cmd->se_sess->sess_prot_type;
709 break;
710 }
711 if (!protect)
712 return TCM_NO_SENSE;
713 fallthrough;
714 default:
715 pr_err("Unable to determine pi_prot_type for CDB: 0x%02x "
716 "PROTECT: 0x%02x\n", cmd->t_task_cdb[0], protect);
717 return TCM_INVALID_CDB_FIELD;
718 }
719
720 if (sbc_set_prot_op_checks(protect, fabric_prot, pi_prot_type, is_write, cmd))
721 return TCM_INVALID_CDB_FIELD;
722
723 cmd->prot_type = pi_prot_type;
724 cmd->prot_length = dev->prot_length * sectors;
725
726 /**
727 * In case protection information exists over the wire
728 * we modify command data length to describe pure data.
729 * The actual transfer length is data length + protection
730 * length
731 **/
732 if (protect)
733 cmd->data_length = sectors * dev->dev_attrib.block_size;
734
735 pr_debug("%s: prot_type=%d, data_length=%d, prot_length=%d "
736 "prot_op=%d prot_checks=%d\n",
737 __func__, cmd->prot_type, cmd->data_length, cmd->prot_length,
738 cmd->prot_op, cmd->prot_checks);
739
740 return TCM_NO_SENSE;
741}
742
743static int
744sbc_check_dpofua(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb)
745{
746 if (cdb[1] & 0x10) {
747 /* see explanation in spc_emulate_modesense */
748 if (!target_check_fua(dev)) {
749 pr_err("Got CDB: 0x%02x with DPO bit set, but device"
750 " does not advertise support for DPO\n", cdb[0]);
751 return -EINVAL;
752 }
753 }
754 if (cdb[1] & 0x8) {
755 if (!target_check_fua(dev)) {
756 pr_err("Got CDB: 0x%02x with FUA bit set, but device"
757 " does not advertise support for FUA write\n",
758 cdb[0]);
759 return -EINVAL;
760 }
761 cmd->se_cmd_flags |= SCF_FUA;
762 }
763 return 0;
764}
765
766sense_reason_t
767sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
768{
769 struct se_device *dev = cmd->se_dev;
770 unsigned char *cdb = cmd->t_task_cdb;
771 unsigned int size;
772 u32 sectors = 0;
773 sense_reason_t ret;
774
775 cmd->protocol_data = ops;
776
777 switch (cdb[0]) {
778 case READ_6:
779 sectors = transport_get_sectors_6(cdb);
780 cmd->t_task_lba = transport_lba_21(cdb);
781 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
782 cmd->execute_cmd = sbc_execute_rw;
783 break;
784 case READ_10:
785 sectors = transport_get_sectors_10(cdb);
786 cmd->t_task_lba = transport_lba_32(cdb);
787
788 if (sbc_check_dpofua(dev, cmd, cdb))
789 return TCM_INVALID_CDB_FIELD;
790
791 ret = sbc_check_prot(dev, cmd, cdb[1] >> 5, sectors, false);
792 if (ret)
793 return ret;
794
795 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
796 cmd->execute_cmd = sbc_execute_rw;
797 break;
798 case READ_12:
799 sectors = transport_get_sectors_12(cdb);
800 cmd->t_task_lba = transport_lba_32(cdb);
801
802 if (sbc_check_dpofua(dev, cmd, cdb))
803 return TCM_INVALID_CDB_FIELD;
804
805 ret = sbc_check_prot(dev, cmd, cdb[1] >> 5, sectors, false);
806 if (ret)
807 return ret;
808
809 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
810 cmd->execute_cmd = sbc_execute_rw;
811 break;
812 case READ_16:
813 sectors = transport_get_sectors_16(cdb);
814 cmd->t_task_lba = transport_lba_64(cdb);
815
816 if (sbc_check_dpofua(dev, cmd, cdb))
817 return TCM_INVALID_CDB_FIELD;
818
819 ret = sbc_check_prot(dev, cmd, cdb[1] >> 5, sectors, false);
820 if (ret)
821 return ret;
822
823 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
824 cmd->execute_cmd = sbc_execute_rw;
825 break;
826 case WRITE_6:
827 sectors = transport_get_sectors_6(cdb);
828 cmd->t_task_lba = transport_lba_21(cdb);
829 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
830 cmd->execute_cmd = sbc_execute_rw;
831 break;
832 case WRITE_10:
833 case WRITE_VERIFY:
834 sectors = transport_get_sectors_10(cdb);
835 cmd->t_task_lba = transport_lba_32(cdb);
836
837 if (sbc_check_dpofua(dev, cmd, cdb))
838 return TCM_INVALID_CDB_FIELD;
839
840 ret = sbc_check_prot(dev, cmd, cdb[1] >> 5, sectors, true);
841 if (ret)
842 return ret;
843
844 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
845 cmd->execute_cmd = sbc_execute_rw;
846 break;
847 case WRITE_12:
848 sectors = transport_get_sectors_12(cdb);
849 cmd->t_task_lba = transport_lba_32(cdb);
850
851 if (sbc_check_dpofua(dev, cmd, cdb))
852 return TCM_INVALID_CDB_FIELD;
853
854 ret = sbc_check_prot(dev, cmd, cdb[1] >> 5, sectors, true);
855 if (ret)
856 return ret;
857
858 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
859 cmd->execute_cmd = sbc_execute_rw;
860 break;
861 case WRITE_16:
862 case WRITE_VERIFY_16:
863 sectors = transport_get_sectors_16(cdb);
864 cmd->t_task_lba = transport_lba_64(cdb);
865
866 if (sbc_check_dpofua(dev, cmd, cdb))
867 return TCM_INVALID_CDB_FIELD;
868
869 ret = sbc_check_prot(dev, cmd, cdb[1] >> 5, sectors, true);
870 if (ret)
871 return ret;
872
873 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
874 cmd->execute_cmd = sbc_execute_rw;
875 break;
876 case VARIABLE_LENGTH_CMD:
877 {
878 u16 service_action = get_unaligned_be16(&cdb[8]);
879 switch (service_action) {
880 case WRITE_SAME_32:
881 sectors = transport_get_sectors_32(cdb);
882 if (!sectors) {
883 pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not"
884 " supported\n");
885 return TCM_INVALID_CDB_FIELD;
886 }
887
888 size = sbc_get_size(cmd, 1);
889 cmd->t_task_lba = get_unaligned_be64(&cdb[12]);
890
891 ret = sbc_setup_write_same(cmd, cdb[10], ops);
892 if (ret)
893 return ret;
894 break;
895 default:
896 pr_err("VARIABLE_LENGTH_CMD service action"
897 " 0x%04x not supported\n", service_action);
898 return TCM_UNSUPPORTED_SCSI_OPCODE;
899 }
900 break;
901 }
902 case COMPARE_AND_WRITE:
903 if (!dev->dev_attrib.emulate_caw) {
904 pr_err_ratelimited("se_device %s/%s (vpd_unit_serial %s) reject COMPARE_AND_WRITE\n",
905 dev->se_hba->backend->ops->name,
906 config_item_name(&dev->dev_group.cg_item),
907 dev->t10_wwn.unit_serial);
908 return TCM_UNSUPPORTED_SCSI_OPCODE;
909 }
910 sectors = cdb[13];
911 /*
912 * Currently enforce COMPARE_AND_WRITE for a single sector
913 */
914 if (sectors > 1) {
915 pr_err("COMPARE_AND_WRITE contains NoLB: %u greater"
916 " than 1\n", sectors);
917 return TCM_INVALID_CDB_FIELD;
918 }
919 if (sbc_check_dpofua(dev, cmd, cdb))
920 return TCM_INVALID_CDB_FIELD;
921
922 /*
923 * Double size because we have two buffers, note that
924 * zero is not an error..
925 */
926 size = 2 * sbc_get_size(cmd, sectors);
927 cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
928 cmd->t_task_nolb = sectors;
929 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB | SCF_COMPARE_AND_WRITE;
930 cmd->execute_cmd = sbc_compare_and_write;
931 cmd->transport_complete_callback = compare_and_write_callback;
932 break;
933 case READ_CAPACITY:
934 size = READ_CAP_LEN;
935 cmd->execute_cmd = sbc_emulate_readcapacity;
936 break;
937 case SERVICE_ACTION_IN_16:
938 switch (cmd->t_task_cdb[1] & 0x1f) {
939 case SAI_READ_CAPACITY_16:
940 cmd->execute_cmd = sbc_emulate_readcapacity_16;
941 break;
942 case SAI_REPORT_REFERRALS:
943 cmd->execute_cmd = target_emulate_report_referrals;
944 break;
945 default:
946 pr_err("Unsupported SA: 0x%02x\n",
947 cmd->t_task_cdb[1] & 0x1f);
948 return TCM_INVALID_CDB_FIELD;
949 }
950 size = get_unaligned_be32(&cdb[10]);
951 break;
952 case SYNCHRONIZE_CACHE:
953 case SYNCHRONIZE_CACHE_16:
954 if (cdb[0] == SYNCHRONIZE_CACHE) {
955 sectors = transport_get_sectors_10(cdb);
956 cmd->t_task_lba = transport_lba_32(cdb);
957 } else {
958 sectors = transport_get_sectors_16(cdb);
959 cmd->t_task_lba = transport_lba_64(cdb);
960 }
961 if (ops->execute_sync_cache) {
962 cmd->execute_cmd = ops->execute_sync_cache;
963 goto check_lba;
964 }
965 size = 0;
966 cmd->execute_cmd = sbc_emulate_noop;
967 break;
968 case UNMAP:
969 if (!ops->execute_unmap)
970 return TCM_UNSUPPORTED_SCSI_OPCODE;
971
972 if (!dev->dev_attrib.emulate_tpu) {
973 pr_err("Got UNMAP, but backend device has"
974 " emulate_tpu disabled\n");
975 return TCM_UNSUPPORTED_SCSI_OPCODE;
976 }
977 size = get_unaligned_be16(&cdb[7]);
978 cmd->execute_cmd = sbc_execute_unmap;
979 break;
980 case WRITE_SAME_16:
981 sectors = transport_get_sectors_16(cdb);
982 if (!sectors) {
983 pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
984 return TCM_INVALID_CDB_FIELD;
985 }
986
987 size = sbc_get_size(cmd, 1);
988 cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
989
990 ret = sbc_setup_write_same(cmd, cdb[1], ops);
991 if (ret)
992 return ret;
993 break;
994 case WRITE_SAME:
995 sectors = transport_get_sectors_10(cdb);
996 if (!sectors) {
997 pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
998 return TCM_INVALID_CDB_FIELD;
999 }
1000
1001 size = sbc_get_size(cmd, 1);
1002 cmd->t_task_lba = get_unaligned_be32(&cdb[2]);
1003
1004 /*
1005 * Follow sbcr26 with WRITE_SAME (10) and check for the existence
1006 * of byte 1 bit 3 UNMAP instead of original reserved field
1007 */
1008 ret = sbc_setup_write_same(cmd, cdb[1], ops);
1009 if (ret)
1010 return ret;
1011 break;
1012 case VERIFY:
1013 case VERIFY_16:
1014 size = 0;
1015 if (cdb[0] == VERIFY) {
1016 sectors = transport_get_sectors_10(cdb);
1017 cmd->t_task_lba = transport_lba_32(cdb);
1018 } else {
1019 sectors = transport_get_sectors_16(cdb);
1020 cmd->t_task_lba = transport_lba_64(cdb);
1021 }
1022 cmd->execute_cmd = sbc_emulate_noop;
1023 goto check_lba;
1024 case REZERO_UNIT:
1025 case SEEK_6:
1026 case SEEK_10:
1027 /*
1028 * There are still clients out there which use these old SCSI-2
1029 * commands. This mainly happens when running VMs with legacy
1030 * guest systems, connected via SCSI command pass-through to
1031 * iSCSI targets. Make them happy and return status GOOD.
1032 */
1033 size = 0;
1034 cmd->execute_cmd = sbc_emulate_noop;
1035 break;
1036 case START_STOP:
1037 size = 0;
1038 cmd->execute_cmd = sbc_emulate_startstop;
1039 break;
1040 default:
1041 ret = spc_parse_cdb(cmd, &size);
1042 if (ret)
1043 return ret;
1044 }
1045
1046 /* reject any command that we don't have a handler for */
1047 if (!cmd->execute_cmd)
1048 return TCM_UNSUPPORTED_SCSI_OPCODE;
1049
1050 if (cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
1051 unsigned long long end_lba;
1052check_lba:
1053 end_lba = dev->transport->get_blocks(dev) + 1;
1054 if (((cmd->t_task_lba + sectors) < cmd->t_task_lba) ||
1055 ((cmd->t_task_lba + sectors) > end_lba)) {
1056 pr_err("cmd exceeds last lba %llu "
1057 "(lba %llu, sectors %u)\n",
1058 end_lba, cmd->t_task_lba, sectors);
1059 return TCM_ADDRESS_OUT_OF_RANGE;
1060 }
1061
1062 if (!(cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE))
1063 size = sbc_get_size(cmd, sectors);
1064 }
1065
1066 return target_cmd_size_check(cmd, size);
1067}
1068EXPORT_SYMBOL(sbc_parse_cdb);
1069
1070u32 sbc_get_device_type(struct se_device *dev)
1071{
1072 return TYPE_DISK;
1073}
1074EXPORT_SYMBOL(sbc_get_device_type);
1075
1076static sense_reason_t
1077sbc_execute_unmap(struct se_cmd *cmd)
1078{
1079 struct sbc_ops *ops = cmd->protocol_data;
1080 struct se_device *dev = cmd->se_dev;
1081 unsigned char *buf, *ptr = NULL;
1082 sector_t lba;
1083 int size;
1084 u32 range;
1085 sense_reason_t ret = 0;
1086 int dl, bd_dl;
1087
1088 /* We never set ANC_SUP */
1089 if (cmd->t_task_cdb[1])
1090 return TCM_INVALID_CDB_FIELD;
1091
1092 if (cmd->data_length == 0) {
1093 target_complete_cmd(cmd, SAM_STAT_GOOD);
1094 return 0;
1095 }
1096
1097 if (cmd->data_length < 8) {
1098 pr_warn("UNMAP parameter list length %u too small\n",
1099 cmd->data_length);
1100 return TCM_PARAMETER_LIST_LENGTH_ERROR;
1101 }
1102
1103 buf = transport_kmap_data_sg(cmd);
1104 if (!buf)
1105 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1106
1107 dl = get_unaligned_be16(&buf[0]);
1108 bd_dl = get_unaligned_be16(&buf[2]);
1109
1110 size = cmd->data_length - 8;
1111 if (bd_dl > size)
1112 pr_warn("UNMAP parameter list length %u too small, ignoring bd_dl %u\n",
1113 cmd->data_length, bd_dl);
1114 else
1115 size = bd_dl;
1116
1117 if (size / 16 > dev->dev_attrib.max_unmap_block_desc_count) {
1118 ret = TCM_INVALID_PARAMETER_LIST;
1119 goto err;
1120 }
1121
1122 /* First UNMAP block descriptor starts at 8 byte offset */
1123 ptr = &buf[8];
1124 pr_debug("UNMAP: Sub: %s Using dl: %u bd_dl: %u size: %u"
1125 " ptr: %p\n", dev->transport->name, dl, bd_dl, size, ptr);
1126
1127 while (size >= 16) {
1128 lba = get_unaligned_be64(&ptr[0]);
1129 range = get_unaligned_be32(&ptr[8]);
1130 pr_debug("UNMAP: Using lba: %llu and range: %u\n",
1131 (unsigned long long)lba, range);
1132
1133 if (range > dev->dev_attrib.max_unmap_lba_count) {
1134 ret = TCM_INVALID_PARAMETER_LIST;
1135 goto err;
1136 }
1137
1138 if (lba + range > dev->transport->get_blocks(dev) + 1) {
1139 ret = TCM_ADDRESS_OUT_OF_RANGE;
1140 goto err;
1141 }
1142
1143 if (range) {
1144 ret = ops->execute_unmap(cmd, lba, range);
1145 if (ret)
1146 goto err;
1147 }
1148
1149 ptr += 16;
1150 size -= 16;
1151 }
1152
1153err:
1154 transport_kunmap_data_sg(cmd);
1155 if (!ret)
1156 target_complete_cmd(cmd, SAM_STAT_GOOD);
1157 return ret;
1158}
1159
1160void
1161sbc_dif_generate(struct se_cmd *cmd)
1162{
1163 struct se_device *dev = cmd->se_dev;
1164 struct t10_pi_tuple *sdt;
1165 struct scatterlist *dsg = cmd->t_data_sg, *psg;
1166 sector_t sector = cmd->t_task_lba;
1167 void *daddr, *paddr;
1168 int i, j, offset = 0;
1169 unsigned int block_size = dev->dev_attrib.block_size;
1170
1171 for_each_sg(cmd->t_prot_sg, psg, cmd->t_prot_nents, i) {
1172 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1173 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1174
1175 for (j = 0; j < psg->length;
1176 j += sizeof(*sdt)) {
1177 __u16 crc;
1178 unsigned int avail;
1179
1180 if (offset >= dsg->length) {
1181 offset -= dsg->length;
1182 kunmap_atomic(daddr - dsg->offset);
1183 dsg = sg_next(dsg);
1184 if (!dsg) {
1185 kunmap_atomic(paddr - psg->offset);
1186 return;
1187 }
1188 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1189 }
1190
1191 sdt = paddr + j;
1192 avail = min(block_size, dsg->length - offset);
1193 crc = crc_t10dif(daddr + offset, avail);
1194 if (avail < block_size) {
1195 kunmap_atomic(daddr - dsg->offset);
1196 dsg = sg_next(dsg);
1197 if (!dsg) {
1198 kunmap_atomic(paddr - psg->offset);
1199 return;
1200 }
1201 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1202 offset = block_size - avail;
1203 crc = crc_t10dif_update(crc, daddr, offset);
1204 } else {
1205 offset += block_size;
1206 }
1207
1208 sdt->guard_tag = cpu_to_be16(crc);
1209 if (cmd->prot_type == TARGET_DIF_TYPE1_PROT)
1210 sdt->ref_tag = cpu_to_be32(sector & 0xffffffff);
1211 sdt->app_tag = 0;
1212
1213 pr_debug("DIF %s INSERT sector: %llu guard_tag: 0x%04x"
1214 " app_tag: 0x%04x ref_tag: %u\n",
1215 (cmd->data_direction == DMA_TO_DEVICE) ?
1216 "WRITE" : "READ", (unsigned long long)sector,
1217 sdt->guard_tag, sdt->app_tag,
1218 be32_to_cpu(sdt->ref_tag));
1219
1220 sector++;
1221 }
1222
1223 kunmap_atomic(daddr - dsg->offset);
1224 kunmap_atomic(paddr - psg->offset);
1225 }
1226}
1227
1228static sense_reason_t
1229sbc_dif_v1_verify(struct se_cmd *cmd, struct t10_pi_tuple *sdt,
1230 __u16 crc, sector_t sector, unsigned int ei_lba)
1231{
1232 __be16 csum;
1233
1234 if (!(cmd->prot_checks & TARGET_DIF_CHECK_GUARD))
1235 goto check_ref;
1236
1237 csum = cpu_to_be16(crc);
1238
1239 if (sdt->guard_tag != csum) {
1240 pr_err("DIFv1 checksum failed on sector %llu guard tag 0x%04x"
1241 " csum 0x%04x\n", (unsigned long long)sector,
1242 be16_to_cpu(sdt->guard_tag), be16_to_cpu(csum));
1243 return TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED;
1244 }
1245
1246check_ref:
1247 if (!(cmd->prot_checks & TARGET_DIF_CHECK_REFTAG))
1248 return 0;
1249
1250 if (cmd->prot_type == TARGET_DIF_TYPE1_PROT &&
1251 be32_to_cpu(sdt->ref_tag) != (sector & 0xffffffff)) {
1252 pr_err("DIFv1 Type 1 reference failed on sector: %llu tag: 0x%08x"
1253 " sector MSB: 0x%08x\n", (unsigned long long)sector,
1254 be32_to_cpu(sdt->ref_tag), (u32)(sector & 0xffffffff));
1255 return TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;
1256 }
1257
1258 if (cmd->prot_type == TARGET_DIF_TYPE2_PROT &&
1259 be32_to_cpu(sdt->ref_tag) != ei_lba) {
1260 pr_err("DIFv1 Type 2 reference failed on sector: %llu tag: 0x%08x"
1261 " ei_lba: 0x%08x\n", (unsigned long long)sector,
1262 be32_to_cpu(sdt->ref_tag), ei_lba);
1263 return TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;
1264 }
1265
1266 return 0;
1267}
1268
1269void sbc_dif_copy_prot(struct se_cmd *cmd, unsigned int sectors, bool read,
1270 struct scatterlist *sg, int sg_off)
1271{
1272 struct se_device *dev = cmd->se_dev;
1273 struct scatterlist *psg;
1274 void *paddr, *addr;
1275 unsigned int i, len, left;
1276 unsigned int offset = sg_off;
1277
1278 if (!sg)
1279 return;
1280
1281 left = sectors * dev->prot_length;
1282
1283 for_each_sg(cmd->t_prot_sg, psg, cmd->t_prot_nents, i) {
1284 unsigned int psg_len, copied = 0;
1285
1286 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1287 psg_len = min(left, psg->length);
1288 while (psg_len) {
1289 len = min(psg_len, sg->length - offset);
1290 addr = kmap_atomic(sg_page(sg)) + sg->offset + offset;
1291
1292 if (read)
1293 memcpy(paddr + copied, addr, len);
1294 else
1295 memcpy(addr, paddr + copied, len);
1296
1297 left -= len;
1298 offset += len;
1299 copied += len;
1300 psg_len -= len;
1301
1302 kunmap_atomic(addr - sg->offset - offset);
1303
1304 if (offset >= sg->length) {
1305 sg = sg_next(sg);
1306 offset = 0;
1307 }
1308 }
1309 kunmap_atomic(paddr - psg->offset);
1310 }
1311}
1312EXPORT_SYMBOL(sbc_dif_copy_prot);
1313
1314sense_reason_t
1315sbc_dif_verify(struct se_cmd *cmd, sector_t start, unsigned int sectors,
1316 unsigned int ei_lba, struct scatterlist *psg, int psg_off)
1317{
1318 struct se_device *dev = cmd->se_dev;
1319 struct t10_pi_tuple *sdt;
1320 struct scatterlist *dsg = cmd->t_data_sg;
1321 sector_t sector = start;
1322 void *daddr, *paddr;
1323 int i;
1324 sense_reason_t rc;
1325 int dsg_off = 0;
1326 unsigned int block_size = dev->dev_attrib.block_size;
1327
1328 for (; psg && sector < start + sectors; psg = sg_next(psg)) {
1329 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1330 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1331
1332 for (i = psg_off; i < psg->length &&
1333 sector < start + sectors;
1334 i += sizeof(*sdt)) {
1335 __u16 crc;
1336 unsigned int avail;
1337
1338 if (dsg_off >= dsg->length) {
1339 dsg_off -= dsg->length;
1340 kunmap_atomic(daddr - dsg->offset);
1341 dsg = sg_next(dsg);
1342 if (!dsg) {
1343 kunmap_atomic(paddr - psg->offset);
1344 return 0;
1345 }
1346 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1347 }
1348
1349 sdt = paddr + i;
1350
1351 pr_debug("DIF READ sector: %llu guard_tag: 0x%04x"
1352 " app_tag: 0x%04x ref_tag: %u\n",
1353 (unsigned long long)sector, sdt->guard_tag,
1354 sdt->app_tag, be32_to_cpu(sdt->ref_tag));
1355
1356 if (sdt->app_tag == T10_PI_APP_ESCAPE) {
1357 dsg_off += block_size;
1358 goto next;
1359 }
1360
1361 avail = min(block_size, dsg->length - dsg_off);
1362 crc = crc_t10dif(daddr + dsg_off, avail);
1363 if (avail < block_size) {
1364 kunmap_atomic(daddr - dsg->offset);
1365 dsg = sg_next(dsg);
1366 if (!dsg) {
1367 kunmap_atomic(paddr - psg->offset);
1368 return 0;
1369 }
1370 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1371 dsg_off = block_size - avail;
1372 crc = crc_t10dif_update(crc, daddr, dsg_off);
1373 } else {
1374 dsg_off += block_size;
1375 }
1376
1377 rc = sbc_dif_v1_verify(cmd, sdt, crc, sector, ei_lba);
1378 if (rc) {
1379 kunmap_atomic(daddr - dsg->offset);
1380 kunmap_atomic(paddr - psg->offset);
1381 cmd->sense_info = sector;
1382 return rc;
1383 }
1384next:
1385 sector++;
1386 ei_lba++;
1387 }
1388
1389 psg_off = 0;
1390 kunmap_atomic(daddr - dsg->offset);
1391 kunmap_atomic(paddr - psg->offset);
1392 }
1393
1394 return 0;
1395}
1396EXPORT_SYMBOL(sbc_dif_verify);