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 
27 static sense_reason_t
28 sbc_check_prot(struct se_device *, struct se_cmd *, unsigned char *, u32, bool);
29 static sense_reason_t sbc_execute_unmap(struct se_cmd *cmd);
30 
31 static sense_reason_t
32 sbc_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, GOOD, 8);
71 	return 0;
72 }
73 
74 static sense_reason_t
75 sbc_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, GOOD, 32);
134 	return 0;
135 }
136 
137 static sense_reason_t
138 sbc_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 
169 sector_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 }
190 EXPORT_SYMBOL(sbc_get_write_same_sectors);
191 
192 static sense_reason_t
193 sbc_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, GOOD);
206 	return 0;
207 }
208 
209 static sense_reason_t
210 sbc_emulate_noop(struct se_cmd *cmd)
211 {
212 	target_complete_cmd(cmd, GOOD);
213 	return 0;
214 }
215 
216 static inline u32 sbc_get_size(struct se_cmd *cmd, u32 sectors)
217 {
218 	return cmd->se_dev->dev_attrib.block_size * sectors;
219 }
220 
221 static 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 
234 static inline u32 transport_get_sectors_10(unsigned char *cdb)
235 {
236 	return get_unaligned_be16(&cdb[7]);
237 }
238 
239 static inline u32 transport_get_sectors_12(unsigned char *cdb)
240 {
241 	return get_unaligned_be32(&cdb[6]);
242 }
243 
244 static 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  */
252 static inline u32 transport_get_sectors_32(unsigned char *cdb)
253 {
254 	return get_unaligned_be32(&cdb[28]);
255 
256 }
257 
258 static inline u32 transport_lba_21(unsigned char *cdb)
259 {
260 	return get_unaligned_be24(&cdb[1]) & 0x1fffff;
261 }
262 
263 static inline u32 transport_lba_32(unsigned char *cdb)
264 {
265 	return get_unaligned_be32(&cdb[2]);
266 }
267 
268 static inline unsigned long long transport_lba_64(unsigned char *cdb)
269 {
270 	return get_unaligned_be64(&cdb[2]);
271 }
272 
273 /*
274  * For VARIABLE_LENGTH_CDB w/ 32 byte extended CDBs
275  */
276 static inline unsigned long long transport_lba_64_ext(unsigned char *cdb)
277 {
278 	return get_unaligned_be64(&cdb[12]);
279 }
280 
281 static sense_reason_t
282 sbc_setup_write_same(struct se_cmd *cmd, unsigned char *flags, struct sbc_ops *ops)
283 {
284 	struct se_device *dev = cmd->se_dev;
285 	sector_t end_lba = dev->transport->get_blocks(dev) + 1;
286 	unsigned int sectors = sbc_get_write_same_sectors(cmd);
287 	sense_reason_t ret;
288 
289 	if ((flags[0] & 0x04) || (flags[0] & 0x02)) {
290 		pr_err("WRITE_SAME PBDATA and LBDATA"
291 			" bits not supported for Block Discard"
292 			" Emulation\n");
293 		return TCM_UNSUPPORTED_SCSI_OPCODE;
294 	}
295 	if (sectors > cmd->se_dev->dev_attrib.max_write_same_len) {
296 		pr_warn("WRITE_SAME sectors: %u exceeds max_write_same_len: %u\n",
297 			sectors, cmd->se_dev->dev_attrib.max_write_same_len);
298 		return TCM_INVALID_CDB_FIELD;
299 	}
300 	/*
301 	 * Sanity check for LBA wrap and request past end of device.
302 	 */
303 	if (((cmd->t_task_lba + sectors) < cmd->t_task_lba) ||
304 	    ((cmd->t_task_lba + sectors) > end_lba)) {
305 		pr_err("WRITE_SAME exceeds last lba %llu (lba %llu, sectors %u)\n",
306 		       (unsigned long long)end_lba, cmd->t_task_lba, sectors);
307 		return TCM_ADDRESS_OUT_OF_RANGE;
308 	}
309 
310 	/* We always have ANC_SUP == 0 so setting ANCHOR is always an error */
311 	if (flags[0] & 0x10) {
312 		pr_warn("WRITE SAME with ANCHOR not supported\n");
313 		return TCM_INVALID_CDB_FIELD;
314 	}
315 	/*
316 	 * Special case for WRITE_SAME w/ UNMAP=1 that ends up getting
317 	 * translated into block discard requests within backend code.
318 	 */
319 	if (flags[0] & 0x08) {
320 		if (!ops->execute_unmap)
321 			return TCM_UNSUPPORTED_SCSI_OPCODE;
322 
323 		if (!dev->dev_attrib.emulate_tpws) {
324 			pr_err("Got WRITE_SAME w/ UNMAP=1, but backend device"
325 			       " has emulate_tpws disabled\n");
326 			return TCM_UNSUPPORTED_SCSI_OPCODE;
327 		}
328 		cmd->execute_cmd = sbc_execute_write_same_unmap;
329 		return 0;
330 	}
331 	if (!ops->execute_write_same)
332 		return TCM_UNSUPPORTED_SCSI_OPCODE;
333 
334 	ret = sbc_check_prot(dev, cmd, &cmd->t_task_cdb[0], sectors, true);
335 	if (ret)
336 		return ret;
337 
338 	cmd->execute_cmd = ops->execute_write_same;
339 	return 0;
340 }
341 
342 static sense_reason_t xdreadwrite_callback(struct se_cmd *cmd, bool success,
343 					   int *post_ret)
344 {
345 	unsigned char *buf, *addr;
346 	struct scatterlist *sg;
347 	unsigned int offset;
348 	sense_reason_t ret = TCM_NO_SENSE;
349 	int i, count;
350 
351 	if (!success)
352 		return 0;
353 
354 	/*
355 	 * From sbc3r22.pdf section 5.48 XDWRITEREAD (10) command
356 	 *
357 	 * 1) read the specified logical block(s);
358 	 * 2) transfer logical blocks from the data-out buffer;
359 	 * 3) XOR the logical blocks transferred from the data-out buffer with
360 	 *    the logical blocks read, storing the resulting XOR data in a buffer;
361 	 * 4) if the DISABLE WRITE bit is set to zero, then write the logical
362 	 *    blocks transferred from the data-out buffer; and
363 	 * 5) transfer the resulting XOR data to the data-in buffer.
364 	 */
365 	buf = kmalloc(cmd->data_length, GFP_KERNEL);
366 	if (!buf) {
367 		pr_err("Unable to allocate xor_callback buf\n");
368 		return TCM_OUT_OF_RESOURCES;
369 	}
370 	/*
371 	 * Copy the scatterlist WRITE buffer located at cmd->t_data_sg
372 	 * into the locally allocated *buf
373 	 */
374 	sg_copy_to_buffer(cmd->t_data_sg,
375 			  cmd->t_data_nents,
376 			  buf,
377 			  cmd->data_length);
378 
379 	/*
380 	 * Now perform the XOR against the BIDI read memory located at
381 	 * cmd->t_mem_bidi_list
382 	 */
383 
384 	offset = 0;
385 	for_each_sg(cmd->t_bidi_data_sg, sg, cmd->t_bidi_data_nents, count) {
386 		addr = kmap_atomic(sg_page(sg));
387 		if (!addr) {
388 			ret = TCM_OUT_OF_RESOURCES;
389 			goto out;
390 		}
391 
392 		for (i = 0; i < sg->length; i++)
393 			*(addr + sg->offset + i) ^= *(buf + offset + i);
394 
395 		offset += sg->length;
396 		kunmap_atomic(addr);
397 	}
398 
399 out:
400 	kfree(buf);
401 	return ret;
402 }
403 
404 static sense_reason_t
405 sbc_execute_rw(struct se_cmd *cmd)
406 {
407 	struct sbc_ops *ops = cmd->protocol_data;
408 
409 	return ops->execute_rw(cmd, cmd->t_data_sg, cmd->t_data_nents,
410 			       cmd->data_direction);
411 }
412 
413 static sense_reason_t compare_and_write_post(struct se_cmd *cmd, bool success,
414 					     int *post_ret)
415 {
416 	struct se_device *dev = cmd->se_dev;
417 	sense_reason_t ret = TCM_NO_SENSE;
418 
419 	spin_lock_irq(&cmd->t_state_lock);
420 	if (success) {
421 		*post_ret = 1;
422 
423 		if (cmd->scsi_status == SAM_STAT_CHECK_CONDITION)
424 			ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
425 	}
426 	spin_unlock_irq(&cmd->t_state_lock);
427 
428 	/*
429 	 * Unlock ->caw_sem originally obtained during sbc_compare_and_write()
430 	 * before the original READ I/O submission.
431 	 */
432 	up(&dev->caw_sem);
433 
434 	return ret;
435 }
436 
437 /*
438  * compare @cmp_len bytes of @read_sgl with @cmp_sgl. On miscompare, fill
439  * @miscmp_off and return TCM_MISCOMPARE_VERIFY.
440  */
441 static sense_reason_t
442 compare_and_write_do_cmp(struct scatterlist *read_sgl, unsigned int read_nents,
443 			 struct scatterlist *cmp_sgl, unsigned int cmp_nents,
444 			 unsigned int cmp_len, unsigned int *miscmp_off)
445 {
446 	unsigned char *buf = NULL;
447 	struct scatterlist *sg;
448 	sense_reason_t ret;
449 	unsigned int offset;
450 	size_t rc;
451 	int sg_cnt;
452 
453 	buf = kzalloc(cmp_len, GFP_KERNEL);
454 	if (!buf) {
455 		ret = TCM_OUT_OF_RESOURCES;
456 		goto out;
457 	}
458 
459 	rc = sg_copy_to_buffer(cmp_sgl, cmp_nents, buf, cmp_len);
460 	if (!rc) {
461 		pr_err("sg_copy_to_buffer() failed for compare_and_write\n");
462 		ret = TCM_OUT_OF_RESOURCES;
463 		goto out;
464 	}
465 	/*
466 	 * Compare SCSI READ payload against verify payload
467 	 */
468 	offset = 0;
469 	ret = TCM_NO_SENSE;
470 	for_each_sg(read_sgl, sg, read_nents, sg_cnt) {
471 		unsigned int len = min(sg->length, cmp_len);
472 		unsigned char *addr = kmap_atomic(sg_page(sg));
473 
474 		if (memcmp(addr, buf + offset, len)) {
475 			unsigned int i;
476 
477 			for (i = 0; i < len && addr[i] == buf[offset + i]; i++)
478 				;
479 			*miscmp_off = offset + i;
480 			pr_warn("Detected MISCOMPARE at offset %u\n",
481 				*miscmp_off);
482 			ret = TCM_MISCOMPARE_VERIFY;
483 		}
484 		kunmap_atomic(addr);
485 		if (ret != TCM_NO_SENSE)
486 			goto out;
487 
488 		offset += len;
489 		cmp_len -= len;
490 		if (!cmp_len)
491 			break;
492 	}
493 	pr_debug("COMPARE AND WRITE read data matches compare data\n");
494 out:
495 	kfree(buf);
496 	return ret;
497 }
498 
499 static sense_reason_t compare_and_write_callback(struct se_cmd *cmd, bool success,
500 						 int *post_ret)
501 {
502 	struct se_device *dev = cmd->se_dev;
503 	struct sg_table write_tbl = { };
504 	struct scatterlist *write_sg;
505 	struct sg_mapping_iter m;
506 	unsigned int len;
507 	unsigned int block_size = dev->dev_attrib.block_size;
508 	unsigned int compare_len = (cmd->t_task_nolb * block_size);
509 	unsigned int miscmp_off = 0;
510 	sense_reason_t ret = TCM_NO_SENSE;
511 	int i;
512 
513 	/*
514 	 * Handle early failure in transport_generic_request_failure(),
515 	 * which will not have taken ->caw_sem yet..
516 	 */
517 	if (!success && (!cmd->t_data_sg || !cmd->t_bidi_data_sg))
518 		return TCM_NO_SENSE;
519 	/*
520 	 * Handle special case for zero-length COMPARE_AND_WRITE
521 	 */
522 	if (!cmd->data_length)
523 		goto out;
524 	/*
525 	 * Immediately exit + release dev->caw_sem if command has already
526 	 * been failed with a non-zero SCSI status.
527 	 */
528 	if (cmd->scsi_status) {
529 		pr_debug("compare_and_write_callback: non zero scsi_status:"
530 			" 0x%02x\n", cmd->scsi_status);
531 		*post_ret = 1;
532 		if (cmd->scsi_status == SAM_STAT_CHECK_CONDITION)
533 			ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
534 		goto out;
535 	}
536 
537 	ret = compare_and_write_do_cmp(cmd->t_bidi_data_sg,
538 				       cmd->t_bidi_data_nents,
539 				       cmd->t_data_sg,
540 				       cmd->t_data_nents,
541 				       compare_len,
542 				       &miscmp_off);
543 	if (ret == TCM_MISCOMPARE_VERIFY) {
544 		/*
545 		 * SBC-4 r15: 5.3 COMPARE AND WRITE command
546 		 * In the sense data (see 4.18 and SPC-5) the offset from the
547 		 * start of the Data-Out Buffer to the first byte of data that
548 		 * was not equal shall be reported in the INFORMATION field.
549 		 */
550 		cmd->sense_info = miscmp_off;
551 		goto out;
552 	} else if (ret)
553 		goto out;
554 
555 	if (sg_alloc_table(&write_tbl, cmd->t_data_nents, GFP_KERNEL) < 0) {
556 		pr_err("Unable to allocate compare_and_write sg\n");
557 		ret = TCM_OUT_OF_RESOURCES;
558 		goto out;
559 	}
560 	write_sg = write_tbl.sgl;
561 
562 	i = 0;
563 	len = compare_len;
564 	sg_miter_start(&m, cmd->t_data_sg, cmd->t_data_nents, SG_MITER_TO_SG);
565 	/*
566 	 * Currently assumes NoLB=1 and SGLs are PAGE_SIZE..
567 	 */
568 	while (len) {
569 		sg_miter_next(&m);
570 
571 		if (block_size < PAGE_SIZE) {
572 			sg_set_page(&write_sg[i], m.page, block_size,
573 				    m.piter.sg->offset + block_size);
574 		} else {
575 			sg_miter_next(&m);
576 			sg_set_page(&write_sg[i], m.page, block_size,
577 				    m.piter.sg->offset);
578 		}
579 		len -= block_size;
580 		i++;
581 	}
582 	sg_miter_stop(&m);
583 	/*
584 	 * Save the original SGL + nents values before updating to new
585 	 * assignments, to be released in transport_free_pages() ->
586 	 * transport_reset_sgl_orig()
587 	 */
588 	cmd->t_data_sg_orig = cmd->t_data_sg;
589 	cmd->t_data_sg = write_sg;
590 	cmd->t_data_nents_orig = cmd->t_data_nents;
591 	cmd->t_data_nents = 1;
592 
593 	cmd->sam_task_attr = TCM_HEAD_TAG;
594 	cmd->transport_complete_callback = compare_and_write_post;
595 	/*
596 	 * Now reset ->execute_cmd() to the normal sbc_execute_rw() handler
597 	 * for submitting the adjusted SGL to write instance user-data.
598 	 */
599 	cmd->execute_cmd = sbc_execute_rw;
600 
601 	spin_lock_irq(&cmd->t_state_lock);
602 	cmd->t_state = TRANSPORT_PROCESSING;
603 	cmd->transport_state |= CMD_T_ACTIVE | CMD_T_SENT;
604 	spin_unlock_irq(&cmd->t_state_lock);
605 
606 	__target_execute_cmd(cmd, false);
607 
608 	return ret;
609 
610 out:
611 	/*
612 	 * In the MISCOMPARE or failure case, unlock ->caw_sem obtained in
613 	 * sbc_compare_and_write() before the original READ I/O submission.
614 	 */
615 	up(&dev->caw_sem);
616 	sg_free_table(&write_tbl);
617 	return ret;
618 }
619 
620 static sense_reason_t
621 sbc_compare_and_write(struct se_cmd *cmd)
622 {
623 	struct sbc_ops *ops = cmd->protocol_data;
624 	struct se_device *dev = cmd->se_dev;
625 	sense_reason_t ret;
626 	int rc;
627 	/*
628 	 * Submit the READ first for COMPARE_AND_WRITE to perform the
629 	 * comparision using SGLs at cmd->t_bidi_data_sg..
630 	 */
631 	rc = down_interruptible(&dev->caw_sem);
632 	if (rc != 0) {
633 		cmd->transport_complete_callback = NULL;
634 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
635 	}
636 	/*
637 	 * Reset cmd->data_length to individual block_size in order to not
638 	 * confuse backend drivers that depend on this value matching the
639 	 * size of the I/O being submitted.
640 	 */
641 	cmd->data_length = cmd->t_task_nolb * dev->dev_attrib.block_size;
642 
643 	ret = ops->execute_rw(cmd, cmd->t_bidi_data_sg, cmd->t_bidi_data_nents,
644 			      DMA_FROM_DEVICE);
645 	if (ret) {
646 		cmd->transport_complete_callback = NULL;
647 		up(&dev->caw_sem);
648 		return ret;
649 	}
650 	/*
651 	 * Unlock of dev->caw_sem to occur in compare_and_write_callback()
652 	 * upon MISCOMPARE, or in compare_and_write_done() upon completion
653 	 * of WRITE instance user-data.
654 	 */
655 	return TCM_NO_SENSE;
656 }
657 
658 static int
659 sbc_set_prot_op_checks(u8 protect, bool fabric_prot, enum target_prot_type prot_type,
660 		       bool is_write, struct se_cmd *cmd)
661 {
662 	if (is_write) {
663 		cmd->prot_op = fabric_prot ? TARGET_PROT_DOUT_STRIP :
664 			       protect ? TARGET_PROT_DOUT_PASS :
665 			       TARGET_PROT_DOUT_INSERT;
666 		switch (protect) {
667 		case 0x0:
668 		case 0x3:
669 			cmd->prot_checks = 0;
670 			break;
671 		case 0x1:
672 		case 0x5:
673 			cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
674 			if (prot_type == TARGET_DIF_TYPE1_PROT)
675 				cmd->prot_checks |= TARGET_DIF_CHECK_REFTAG;
676 			break;
677 		case 0x2:
678 			if (prot_type == TARGET_DIF_TYPE1_PROT)
679 				cmd->prot_checks = TARGET_DIF_CHECK_REFTAG;
680 			break;
681 		case 0x4:
682 			cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
683 			break;
684 		default:
685 			pr_err("Unsupported protect field %d\n", protect);
686 			return -EINVAL;
687 		}
688 	} else {
689 		cmd->prot_op = fabric_prot ? TARGET_PROT_DIN_INSERT :
690 			       protect ? TARGET_PROT_DIN_PASS :
691 			       TARGET_PROT_DIN_STRIP;
692 		switch (protect) {
693 		case 0x0:
694 		case 0x1:
695 		case 0x5:
696 			cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
697 			if (prot_type == TARGET_DIF_TYPE1_PROT)
698 				cmd->prot_checks |= TARGET_DIF_CHECK_REFTAG;
699 			break;
700 		case 0x2:
701 			if (prot_type == TARGET_DIF_TYPE1_PROT)
702 				cmd->prot_checks = TARGET_DIF_CHECK_REFTAG;
703 			break;
704 		case 0x3:
705 			cmd->prot_checks = 0;
706 			break;
707 		case 0x4:
708 			cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
709 			break;
710 		default:
711 			pr_err("Unsupported protect field %d\n", protect);
712 			return -EINVAL;
713 		}
714 	}
715 
716 	return 0;
717 }
718 
719 static sense_reason_t
720 sbc_check_prot(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb,
721 	       u32 sectors, bool is_write)
722 {
723 	u8 protect = cdb[1] >> 5;
724 	int sp_ops = cmd->se_sess->sup_prot_ops;
725 	int pi_prot_type = dev->dev_attrib.pi_prot_type;
726 	bool fabric_prot = false;
727 
728 	if (!cmd->t_prot_sg || !cmd->t_prot_nents) {
729 		if (unlikely(protect &&
730 		    !dev->dev_attrib.pi_prot_type && !cmd->se_sess->sess_prot_type)) {
731 			pr_err("CDB contains protect bit, but device + fabric does"
732 			       " not advertise PROTECT=1 feature bit\n");
733 			return TCM_INVALID_CDB_FIELD;
734 		}
735 		if (cmd->prot_pto)
736 			return TCM_NO_SENSE;
737 	}
738 
739 	switch (dev->dev_attrib.pi_prot_type) {
740 	case TARGET_DIF_TYPE3_PROT:
741 		cmd->reftag_seed = 0xffffffff;
742 		break;
743 	case TARGET_DIF_TYPE2_PROT:
744 		if (protect)
745 			return TCM_INVALID_CDB_FIELD;
746 
747 		cmd->reftag_seed = cmd->t_task_lba;
748 		break;
749 	case TARGET_DIF_TYPE1_PROT:
750 		cmd->reftag_seed = cmd->t_task_lba;
751 		break;
752 	case TARGET_DIF_TYPE0_PROT:
753 		/*
754 		 * See if the fabric supports T10-PI, and the session has been
755 		 * configured to allow export PROTECT=1 feature bit with backend
756 		 * devices that don't support T10-PI.
757 		 */
758 		fabric_prot = is_write ?
759 			      !!(sp_ops & (TARGET_PROT_DOUT_PASS | TARGET_PROT_DOUT_STRIP)) :
760 			      !!(sp_ops & (TARGET_PROT_DIN_PASS | TARGET_PROT_DIN_INSERT));
761 
762 		if (fabric_prot && cmd->se_sess->sess_prot_type) {
763 			pi_prot_type = cmd->se_sess->sess_prot_type;
764 			break;
765 		}
766 		if (!protect)
767 			return TCM_NO_SENSE;
768 		fallthrough;
769 	default:
770 		pr_err("Unable to determine pi_prot_type for CDB: 0x%02x "
771 		       "PROTECT: 0x%02x\n", cdb[0], protect);
772 		return TCM_INVALID_CDB_FIELD;
773 	}
774 
775 	if (sbc_set_prot_op_checks(protect, fabric_prot, pi_prot_type, is_write, cmd))
776 		return TCM_INVALID_CDB_FIELD;
777 
778 	cmd->prot_type = pi_prot_type;
779 	cmd->prot_length = dev->prot_length * sectors;
780 
781 	/**
782 	 * In case protection information exists over the wire
783 	 * we modify command data length to describe pure data.
784 	 * The actual transfer length is data length + protection
785 	 * length
786 	 **/
787 	if (protect)
788 		cmd->data_length = sectors * dev->dev_attrib.block_size;
789 
790 	pr_debug("%s: prot_type=%d, data_length=%d, prot_length=%d "
791 		 "prot_op=%d prot_checks=%d\n",
792 		 __func__, cmd->prot_type, cmd->data_length, cmd->prot_length,
793 		 cmd->prot_op, cmd->prot_checks);
794 
795 	return TCM_NO_SENSE;
796 }
797 
798 static int
799 sbc_check_dpofua(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb)
800 {
801 	if (cdb[1] & 0x10) {
802 		/* see explanation in spc_emulate_modesense */
803 		if (!target_check_fua(dev)) {
804 			pr_err("Got CDB: 0x%02x with DPO bit set, but device"
805 			       " does not advertise support for DPO\n", cdb[0]);
806 			return -EINVAL;
807 		}
808 	}
809 	if (cdb[1] & 0x8) {
810 		if (!target_check_fua(dev)) {
811 			pr_err("Got CDB: 0x%02x with FUA bit set, but device"
812 			       " does not advertise support for FUA write\n",
813 			       cdb[0]);
814 			return -EINVAL;
815 		}
816 		cmd->se_cmd_flags |= SCF_FUA;
817 	}
818 	return 0;
819 }
820 
821 sense_reason_t
822 sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
823 {
824 	struct se_device *dev = cmd->se_dev;
825 	unsigned char *cdb = cmd->t_task_cdb;
826 	unsigned int size;
827 	u32 sectors = 0;
828 	sense_reason_t ret;
829 
830 	cmd->protocol_data = ops;
831 
832 	switch (cdb[0]) {
833 	case READ_6:
834 		sectors = transport_get_sectors_6(cdb);
835 		cmd->t_task_lba = transport_lba_21(cdb);
836 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
837 		cmd->execute_cmd = sbc_execute_rw;
838 		break;
839 	case READ_10:
840 		sectors = transport_get_sectors_10(cdb);
841 		cmd->t_task_lba = transport_lba_32(cdb);
842 
843 		if (sbc_check_dpofua(dev, cmd, cdb))
844 			return TCM_INVALID_CDB_FIELD;
845 
846 		ret = sbc_check_prot(dev, cmd, cdb, sectors, false);
847 		if (ret)
848 			return ret;
849 
850 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
851 		cmd->execute_cmd = sbc_execute_rw;
852 		break;
853 	case READ_12:
854 		sectors = transport_get_sectors_12(cdb);
855 		cmd->t_task_lba = transport_lba_32(cdb);
856 
857 		if (sbc_check_dpofua(dev, cmd, cdb))
858 			return TCM_INVALID_CDB_FIELD;
859 
860 		ret = sbc_check_prot(dev, cmd, cdb, sectors, false);
861 		if (ret)
862 			return ret;
863 
864 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
865 		cmd->execute_cmd = sbc_execute_rw;
866 		break;
867 	case READ_16:
868 		sectors = transport_get_sectors_16(cdb);
869 		cmd->t_task_lba = transport_lba_64(cdb);
870 
871 		if (sbc_check_dpofua(dev, cmd, cdb))
872 			return TCM_INVALID_CDB_FIELD;
873 
874 		ret = sbc_check_prot(dev, cmd, cdb, sectors, false);
875 		if (ret)
876 			return ret;
877 
878 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
879 		cmd->execute_cmd = sbc_execute_rw;
880 		break;
881 	case WRITE_6:
882 		sectors = transport_get_sectors_6(cdb);
883 		cmd->t_task_lba = transport_lba_21(cdb);
884 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
885 		cmd->execute_cmd = sbc_execute_rw;
886 		break;
887 	case WRITE_10:
888 	case WRITE_VERIFY:
889 		sectors = transport_get_sectors_10(cdb);
890 		cmd->t_task_lba = transport_lba_32(cdb);
891 
892 		if (sbc_check_dpofua(dev, cmd, cdb))
893 			return TCM_INVALID_CDB_FIELD;
894 
895 		ret = sbc_check_prot(dev, cmd, cdb, sectors, true);
896 		if (ret)
897 			return ret;
898 
899 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
900 		cmd->execute_cmd = sbc_execute_rw;
901 		break;
902 	case WRITE_12:
903 		sectors = transport_get_sectors_12(cdb);
904 		cmd->t_task_lba = transport_lba_32(cdb);
905 
906 		if (sbc_check_dpofua(dev, cmd, cdb))
907 			return TCM_INVALID_CDB_FIELD;
908 
909 		ret = sbc_check_prot(dev, cmd, cdb, sectors, true);
910 		if (ret)
911 			return ret;
912 
913 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
914 		cmd->execute_cmd = sbc_execute_rw;
915 		break;
916 	case WRITE_16:
917 	case WRITE_VERIFY_16:
918 		sectors = transport_get_sectors_16(cdb);
919 		cmd->t_task_lba = transport_lba_64(cdb);
920 
921 		if (sbc_check_dpofua(dev, cmd, cdb))
922 			return TCM_INVALID_CDB_FIELD;
923 
924 		ret = sbc_check_prot(dev, cmd, cdb, sectors, true);
925 		if (ret)
926 			return ret;
927 
928 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
929 		cmd->execute_cmd = sbc_execute_rw;
930 		break;
931 	case XDWRITEREAD_10:
932 		if (cmd->data_direction != DMA_TO_DEVICE ||
933 		    !(cmd->se_cmd_flags & SCF_BIDI))
934 			return TCM_INVALID_CDB_FIELD;
935 		sectors = transport_get_sectors_10(cdb);
936 
937 		if (sbc_check_dpofua(dev, cmd, cdb))
938 			return TCM_INVALID_CDB_FIELD;
939 
940 		cmd->t_task_lba = transport_lba_32(cdb);
941 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
942 
943 		/*
944 		 * Setup BIDI XOR callback to be run after I/O completion.
945 		 */
946 		cmd->execute_cmd = sbc_execute_rw;
947 		cmd->transport_complete_callback = &xdreadwrite_callback;
948 		break;
949 	case VARIABLE_LENGTH_CMD:
950 	{
951 		u16 service_action = get_unaligned_be16(&cdb[8]);
952 		switch (service_action) {
953 		case XDWRITEREAD_32:
954 			sectors = transport_get_sectors_32(cdb);
955 
956 			if (sbc_check_dpofua(dev, cmd, cdb))
957 				return TCM_INVALID_CDB_FIELD;
958 			/*
959 			 * Use WRITE_32 and READ_32 opcodes for the emulated
960 			 * XDWRITE_READ_32 logic.
961 			 */
962 			cmd->t_task_lba = transport_lba_64_ext(cdb);
963 			cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
964 
965 			/*
966 			 * Setup BIDI XOR callback to be run during after I/O
967 			 * completion.
968 			 */
969 			cmd->execute_cmd = sbc_execute_rw;
970 			cmd->transport_complete_callback = &xdreadwrite_callback;
971 			break;
972 		case WRITE_SAME_32:
973 			sectors = transport_get_sectors_32(cdb);
974 			if (!sectors) {
975 				pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not"
976 				       " supported\n");
977 				return TCM_INVALID_CDB_FIELD;
978 			}
979 
980 			size = sbc_get_size(cmd, 1);
981 			cmd->t_task_lba = get_unaligned_be64(&cdb[12]);
982 
983 			ret = sbc_setup_write_same(cmd, &cdb[10], ops);
984 			if (ret)
985 				return ret;
986 			break;
987 		default:
988 			pr_err("VARIABLE_LENGTH_CMD service action"
989 				" 0x%04x not supported\n", service_action);
990 			return TCM_UNSUPPORTED_SCSI_OPCODE;
991 		}
992 		break;
993 	}
994 	case COMPARE_AND_WRITE:
995 		if (!dev->dev_attrib.emulate_caw) {
996 			pr_err_ratelimited("se_device %s/%s (vpd_unit_serial %s) reject COMPARE_AND_WRITE\n",
997 					   dev->se_hba->backend->ops->name,
998 					   config_item_name(&dev->dev_group.cg_item),
999 					   dev->t10_wwn.unit_serial);
1000 			return TCM_UNSUPPORTED_SCSI_OPCODE;
1001 		}
1002 		sectors = cdb[13];
1003 		/*
1004 		 * Currently enforce COMPARE_AND_WRITE for a single sector
1005 		 */
1006 		if (sectors > 1) {
1007 			pr_err("COMPARE_AND_WRITE contains NoLB: %u greater"
1008 			       " than 1\n", sectors);
1009 			return TCM_INVALID_CDB_FIELD;
1010 		}
1011 		if (sbc_check_dpofua(dev, cmd, cdb))
1012 			return TCM_INVALID_CDB_FIELD;
1013 
1014 		/*
1015 		 * Double size because we have two buffers, note that
1016 		 * zero is not an error..
1017 		 */
1018 		size = 2 * sbc_get_size(cmd, sectors);
1019 		cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
1020 		cmd->t_task_nolb = sectors;
1021 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB | SCF_COMPARE_AND_WRITE;
1022 		cmd->execute_cmd = sbc_compare_and_write;
1023 		cmd->transport_complete_callback = compare_and_write_callback;
1024 		break;
1025 	case READ_CAPACITY:
1026 		size = READ_CAP_LEN;
1027 		cmd->execute_cmd = sbc_emulate_readcapacity;
1028 		break;
1029 	case SERVICE_ACTION_IN_16:
1030 		switch (cmd->t_task_cdb[1] & 0x1f) {
1031 		case SAI_READ_CAPACITY_16:
1032 			cmd->execute_cmd = sbc_emulate_readcapacity_16;
1033 			break;
1034 		case SAI_REPORT_REFERRALS:
1035 			cmd->execute_cmd = target_emulate_report_referrals;
1036 			break;
1037 		default:
1038 			pr_err("Unsupported SA: 0x%02x\n",
1039 				cmd->t_task_cdb[1] & 0x1f);
1040 			return TCM_INVALID_CDB_FIELD;
1041 		}
1042 		size = get_unaligned_be32(&cdb[10]);
1043 		break;
1044 	case SYNCHRONIZE_CACHE:
1045 	case SYNCHRONIZE_CACHE_16:
1046 		if (cdb[0] == SYNCHRONIZE_CACHE) {
1047 			sectors = transport_get_sectors_10(cdb);
1048 			cmd->t_task_lba = transport_lba_32(cdb);
1049 		} else {
1050 			sectors = transport_get_sectors_16(cdb);
1051 			cmd->t_task_lba = transport_lba_64(cdb);
1052 		}
1053 		if (ops->execute_sync_cache) {
1054 			cmd->execute_cmd = ops->execute_sync_cache;
1055 			goto check_lba;
1056 		}
1057 		size = 0;
1058 		cmd->execute_cmd = sbc_emulate_noop;
1059 		break;
1060 	case UNMAP:
1061 		if (!ops->execute_unmap)
1062 			return TCM_UNSUPPORTED_SCSI_OPCODE;
1063 
1064 		if (!dev->dev_attrib.emulate_tpu) {
1065 			pr_err("Got UNMAP, but backend device has"
1066 			       " emulate_tpu disabled\n");
1067 			return TCM_UNSUPPORTED_SCSI_OPCODE;
1068 		}
1069 		size = get_unaligned_be16(&cdb[7]);
1070 		cmd->execute_cmd = sbc_execute_unmap;
1071 		break;
1072 	case WRITE_SAME_16:
1073 		sectors = transport_get_sectors_16(cdb);
1074 		if (!sectors) {
1075 			pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
1076 			return TCM_INVALID_CDB_FIELD;
1077 		}
1078 
1079 		size = sbc_get_size(cmd, 1);
1080 		cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
1081 
1082 		ret = sbc_setup_write_same(cmd, &cdb[1], ops);
1083 		if (ret)
1084 			return ret;
1085 		break;
1086 	case WRITE_SAME:
1087 		sectors = transport_get_sectors_10(cdb);
1088 		if (!sectors) {
1089 			pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
1090 			return TCM_INVALID_CDB_FIELD;
1091 		}
1092 
1093 		size = sbc_get_size(cmd, 1);
1094 		cmd->t_task_lba = get_unaligned_be32(&cdb[2]);
1095 
1096 		/*
1097 		 * Follow sbcr26 with WRITE_SAME (10) and check for the existence
1098 		 * of byte 1 bit 3 UNMAP instead of original reserved field
1099 		 */
1100 		ret = sbc_setup_write_same(cmd, &cdb[1], ops);
1101 		if (ret)
1102 			return ret;
1103 		break;
1104 	case VERIFY:
1105 	case VERIFY_16:
1106 		size = 0;
1107 		if (cdb[0] == VERIFY) {
1108 			sectors = transport_get_sectors_10(cdb);
1109 			cmd->t_task_lba = transport_lba_32(cdb);
1110 		} else {
1111 			sectors = transport_get_sectors_16(cdb);
1112 			cmd->t_task_lba = transport_lba_64(cdb);
1113 		}
1114 		cmd->execute_cmd = sbc_emulate_noop;
1115 		goto check_lba;
1116 	case REZERO_UNIT:
1117 	case SEEK_6:
1118 	case SEEK_10:
1119 		/*
1120 		 * There are still clients out there which use these old SCSI-2
1121 		 * commands. This mainly happens when running VMs with legacy
1122 		 * guest systems, connected via SCSI command pass-through to
1123 		 * iSCSI targets. Make them happy and return status GOOD.
1124 		 */
1125 		size = 0;
1126 		cmd->execute_cmd = sbc_emulate_noop;
1127 		break;
1128 	case START_STOP:
1129 		size = 0;
1130 		cmd->execute_cmd = sbc_emulate_startstop;
1131 		break;
1132 	default:
1133 		ret = spc_parse_cdb(cmd, &size);
1134 		if (ret)
1135 			return ret;
1136 	}
1137 
1138 	/* reject any command that we don't have a handler for */
1139 	if (!cmd->execute_cmd)
1140 		return TCM_UNSUPPORTED_SCSI_OPCODE;
1141 
1142 	if (cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
1143 		unsigned long long end_lba;
1144 check_lba:
1145 		end_lba = dev->transport->get_blocks(dev) + 1;
1146 		if (((cmd->t_task_lba + sectors) < cmd->t_task_lba) ||
1147 		    ((cmd->t_task_lba + sectors) > end_lba)) {
1148 			pr_err("cmd exceeds last lba %llu "
1149 				"(lba %llu, sectors %u)\n",
1150 				end_lba, cmd->t_task_lba, sectors);
1151 			return TCM_ADDRESS_OUT_OF_RANGE;
1152 		}
1153 
1154 		if (!(cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE))
1155 			size = sbc_get_size(cmd, sectors);
1156 	}
1157 
1158 	return target_cmd_size_check(cmd, size);
1159 }
1160 EXPORT_SYMBOL(sbc_parse_cdb);
1161 
1162 u32 sbc_get_device_type(struct se_device *dev)
1163 {
1164 	return TYPE_DISK;
1165 }
1166 EXPORT_SYMBOL(sbc_get_device_type);
1167 
1168 static sense_reason_t
1169 sbc_execute_unmap(struct se_cmd *cmd)
1170 {
1171 	struct sbc_ops *ops = cmd->protocol_data;
1172 	struct se_device *dev = cmd->se_dev;
1173 	unsigned char *buf, *ptr = NULL;
1174 	sector_t lba;
1175 	int size;
1176 	u32 range;
1177 	sense_reason_t ret = 0;
1178 	int dl, bd_dl;
1179 
1180 	/* We never set ANC_SUP */
1181 	if (cmd->t_task_cdb[1])
1182 		return TCM_INVALID_CDB_FIELD;
1183 
1184 	if (cmd->data_length == 0) {
1185 		target_complete_cmd(cmd, SAM_STAT_GOOD);
1186 		return 0;
1187 	}
1188 
1189 	if (cmd->data_length < 8) {
1190 		pr_warn("UNMAP parameter list length %u too small\n",
1191 			cmd->data_length);
1192 		return TCM_PARAMETER_LIST_LENGTH_ERROR;
1193 	}
1194 
1195 	buf = transport_kmap_data_sg(cmd);
1196 	if (!buf)
1197 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1198 
1199 	dl = get_unaligned_be16(&buf[0]);
1200 	bd_dl = get_unaligned_be16(&buf[2]);
1201 
1202 	size = cmd->data_length - 8;
1203 	if (bd_dl > size)
1204 		pr_warn("UNMAP parameter list length %u too small, ignoring bd_dl %u\n",
1205 			cmd->data_length, bd_dl);
1206 	else
1207 		size = bd_dl;
1208 
1209 	if (size / 16 > dev->dev_attrib.max_unmap_block_desc_count) {
1210 		ret = TCM_INVALID_PARAMETER_LIST;
1211 		goto err;
1212 	}
1213 
1214 	/* First UNMAP block descriptor starts at 8 byte offset */
1215 	ptr = &buf[8];
1216 	pr_debug("UNMAP: Sub: %s Using dl: %u bd_dl: %u size: %u"
1217 		" ptr: %p\n", dev->transport->name, dl, bd_dl, size, ptr);
1218 
1219 	while (size >= 16) {
1220 		lba = get_unaligned_be64(&ptr[0]);
1221 		range = get_unaligned_be32(&ptr[8]);
1222 		pr_debug("UNMAP: Using lba: %llu and range: %u\n",
1223 				 (unsigned long long)lba, range);
1224 
1225 		if (range > dev->dev_attrib.max_unmap_lba_count) {
1226 			ret = TCM_INVALID_PARAMETER_LIST;
1227 			goto err;
1228 		}
1229 
1230 		if (lba + range > dev->transport->get_blocks(dev) + 1) {
1231 			ret = TCM_ADDRESS_OUT_OF_RANGE;
1232 			goto err;
1233 		}
1234 
1235 		if (range) {
1236 			ret = ops->execute_unmap(cmd, lba, range);
1237 			if (ret)
1238 				goto err;
1239 		}
1240 
1241 		ptr += 16;
1242 		size -= 16;
1243 	}
1244 
1245 err:
1246 	transport_kunmap_data_sg(cmd);
1247 	if (!ret)
1248 		target_complete_cmd(cmd, GOOD);
1249 	return ret;
1250 }
1251 
1252 void
1253 sbc_dif_generate(struct se_cmd *cmd)
1254 {
1255 	struct se_device *dev = cmd->se_dev;
1256 	struct t10_pi_tuple *sdt;
1257 	struct scatterlist *dsg = cmd->t_data_sg, *psg;
1258 	sector_t sector = cmd->t_task_lba;
1259 	void *daddr, *paddr;
1260 	int i, j, offset = 0;
1261 	unsigned int block_size = dev->dev_attrib.block_size;
1262 
1263 	for_each_sg(cmd->t_prot_sg, psg, cmd->t_prot_nents, i) {
1264 		paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1265 		daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1266 
1267 		for (j = 0; j < psg->length;
1268 				j += sizeof(*sdt)) {
1269 			__u16 crc;
1270 			unsigned int avail;
1271 
1272 			if (offset >= dsg->length) {
1273 				offset -= dsg->length;
1274 				kunmap_atomic(daddr - dsg->offset);
1275 				dsg = sg_next(dsg);
1276 				if (!dsg) {
1277 					kunmap_atomic(paddr - psg->offset);
1278 					return;
1279 				}
1280 				daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1281 			}
1282 
1283 			sdt = paddr + j;
1284 			avail = min(block_size, dsg->length - offset);
1285 			crc = crc_t10dif(daddr + offset, avail);
1286 			if (avail < block_size) {
1287 				kunmap_atomic(daddr - dsg->offset);
1288 				dsg = sg_next(dsg);
1289 				if (!dsg) {
1290 					kunmap_atomic(paddr - psg->offset);
1291 					return;
1292 				}
1293 				daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1294 				offset = block_size - avail;
1295 				crc = crc_t10dif_update(crc, daddr, offset);
1296 			} else {
1297 				offset += block_size;
1298 			}
1299 
1300 			sdt->guard_tag = cpu_to_be16(crc);
1301 			if (cmd->prot_type == TARGET_DIF_TYPE1_PROT)
1302 				sdt->ref_tag = cpu_to_be32(sector & 0xffffffff);
1303 			sdt->app_tag = 0;
1304 
1305 			pr_debug("DIF %s INSERT sector: %llu guard_tag: 0x%04x"
1306 				 " app_tag: 0x%04x ref_tag: %u\n",
1307 				 (cmd->data_direction == DMA_TO_DEVICE) ?
1308 				 "WRITE" : "READ", (unsigned long long)sector,
1309 				 sdt->guard_tag, sdt->app_tag,
1310 				 be32_to_cpu(sdt->ref_tag));
1311 
1312 			sector++;
1313 		}
1314 
1315 		kunmap_atomic(daddr - dsg->offset);
1316 		kunmap_atomic(paddr - psg->offset);
1317 	}
1318 }
1319 
1320 static sense_reason_t
1321 sbc_dif_v1_verify(struct se_cmd *cmd, struct t10_pi_tuple *sdt,
1322 		  __u16 crc, sector_t sector, unsigned int ei_lba)
1323 {
1324 	__be16 csum;
1325 
1326 	if (!(cmd->prot_checks & TARGET_DIF_CHECK_GUARD))
1327 		goto check_ref;
1328 
1329 	csum = cpu_to_be16(crc);
1330 
1331 	if (sdt->guard_tag != csum) {
1332 		pr_err("DIFv1 checksum failed on sector %llu guard tag 0x%04x"
1333 			" csum 0x%04x\n", (unsigned long long)sector,
1334 			be16_to_cpu(sdt->guard_tag), be16_to_cpu(csum));
1335 		return TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED;
1336 	}
1337 
1338 check_ref:
1339 	if (!(cmd->prot_checks & TARGET_DIF_CHECK_REFTAG))
1340 		return 0;
1341 
1342 	if (cmd->prot_type == TARGET_DIF_TYPE1_PROT &&
1343 	    be32_to_cpu(sdt->ref_tag) != (sector & 0xffffffff)) {
1344 		pr_err("DIFv1 Type 1 reference failed on sector: %llu tag: 0x%08x"
1345 		       " sector MSB: 0x%08x\n", (unsigned long long)sector,
1346 		       be32_to_cpu(sdt->ref_tag), (u32)(sector & 0xffffffff));
1347 		return TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;
1348 	}
1349 
1350 	if (cmd->prot_type == TARGET_DIF_TYPE2_PROT &&
1351 	    be32_to_cpu(sdt->ref_tag) != ei_lba) {
1352 		pr_err("DIFv1 Type 2 reference failed on sector: %llu tag: 0x%08x"
1353 		       " ei_lba: 0x%08x\n", (unsigned long long)sector,
1354 			be32_to_cpu(sdt->ref_tag), ei_lba);
1355 		return TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;
1356 	}
1357 
1358 	return 0;
1359 }
1360 
1361 void sbc_dif_copy_prot(struct se_cmd *cmd, unsigned int sectors, bool read,
1362 		       struct scatterlist *sg, int sg_off)
1363 {
1364 	struct se_device *dev = cmd->se_dev;
1365 	struct scatterlist *psg;
1366 	void *paddr, *addr;
1367 	unsigned int i, len, left;
1368 	unsigned int offset = sg_off;
1369 
1370 	if (!sg)
1371 		return;
1372 
1373 	left = sectors * dev->prot_length;
1374 
1375 	for_each_sg(cmd->t_prot_sg, psg, cmd->t_prot_nents, i) {
1376 		unsigned int psg_len, copied = 0;
1377 
1378 		paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1379 		psg_len = min(left, psg->length);
1380 		while (psg_len) {
1381 			len = min(psg_len, sg->length - offset);
1382 			addr = kmap_atomic(sg_page(sg)) + sg->offset + offset;
1383 
1384 			if (read)
1385 				memcpy(paddr + copied, addr, len);
1386 			else
1387 				memcpy(addr, paddr + copied, len);
1388 
1389 			left -= len;
1390 			offset += len;
1391 			copied += len;
1392 			psg_len -= len;
1393 
1394 			kunmap_atomic(addr - sg->offset - offset);
1395 
1396 			if (offset >= sg->length) {
1397 				sg = sg_next(sg);
1398 				offset = 0;
1399 			}
1400 		}
1401 		kunmap_atomic(paddr - psg->offset);
1402 	}
1403 }
1404 EXPORT_SYMBOL(sbc_dif_copy_prot);
1405 
1406 sense_reason_t
1407 sbc_dif_verify(struct se_cmd *cmd, sector_t start, unsigned int sectors,
1408 	       unsigned int ei_lba, struct scatterlist *psg, int psg_off)
1409 {
1410 	struct se_device *dev = cmd->se_dev;
1411 	struct t10_pi_tuple *sdt;
1412 	struct scatterlist *dsg = cmd->t_data_sg;
1413 	sector_t sector = start;
1414 	void *daddr, *paddr;
1415 	int i;
1416 	sense_reason_t rc;
1417 	int dsg_off = 0;
1418 	unsigned int block_size = dev->dev_attrib.block_size;
1419 
1420 	for (; psg && sector < start + sectors; psg = sg_next(psg)) {
1421 		paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1422 		daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1423 
1424 		for (i = psg_off; i < psg->length &&
1425 				sector < start + sectors;
1426 				i += sizeof(*sdt)) {
1427 			__u16 crc;
1428 			unsigned int avail;
1429 
1430 			if (dsg_off >= dsg->length) {
1431 				dsg_off -= dsg->length;
1432 				kunmap_atomic(daddr - dsg->offset);
1433 				dsg = sg_next(dsg);
1434 				if (!dsg) {
1435 					kunmap_atomic(paddr - psg->offset);
1436 					return 0;
1437 				}
1438 				daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1439 			}
1440 
1441 			sdt = paddr + i;
1442 
1443 			pr_debug("DIF READ sector: %llu guard_tag: 0x%04x"
1444 				 " app_tag: 0x%04x ref_tag: %u\n",
1445 				 (unsigned long long)sector, sdt->guard_tag,
1446 				 sdt->app_tag, be32_to_cpu(sdt->ref_tag));
1447 
1448 			if (sdt->app_tag == T10_PI_APP_ESCAPE) {
1449 				dsg_off += block_size;
1450 				goto next;
1451 			}
1452 
1453 			avail = min(block_size, dsg->length - dsg_off);
1454 			crc = crc_t10dif(daddr + dsg_off, avail);
1455 			if (avail < block_size) {
1456 				kunmap_atomic(daddr - dsg->offset);
1457 				dsg = sg_next(dsg);
1458 				if (!dsg) {
1459 					kunmap_atomic(paddr - psg->offset);
1460 					return 0;
1461 				}
1462 				daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1463 				dsg_off = block_size - avail;
1464 				crc = crc_t10dif_update(crc, daddr, dsg_off);
1465 			} else {
1466 				dsg_off += block_size;
1467 			}
1468 
1469 			rc = sbc_dif_v1_verify(cmd, sdt, crc, sector, ei_lba);
1470 			if (rc) {
1471 				kunmap_atomic(daddr - dsg->offset);
1472 				kunmap_atomic(paddr - psg->offset);
1473 				cmd->sense_info = sector;
1474 				return rc;
1475 			}
1476 next:
1477 			sector++;
1478 			ei_lba++;
1479 		}
1480 
1481 		psg_off = 0;
1482 		kunmap_atomic(daddr - dsg->offset);
1483 		kunmap_atomic(paddr - psg->offset);
1484 	}
1485 
1486 	return 0;
1487 }
1488 EXPORT_SYMBOL(sbc_dif_verify);
1489