1 /*
2  * SCSI Block Commands (SBC) parsing and emulation.
3  *
4  * (c) Copyright 2002-2013 Datera, Inc.
5  *
6  * Nicholas A. Bellinger <nab@kernel.org>
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License as published by
10  * the Free Software Foundation; either version 2 of the License, or
11  * (at your option) any later version.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  * GNU General Public License for more details.
17  *
18  * You should have received a copy of the GNU General Public License
19  * along with this program; if not, write to the Free Software
20  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
21  */
22 
23 #include <linux/kernel.h>
24 #include <linux/module.h>
25 #include <linux/ratelimit.h>
26 #include <linux/crc-t10dif.h>
27 #include <asm/unaligned.h>
28 #include <scsi/scsi.h>
29 #include <scsi/scsi_tcq.h>
30 
31 #include <target/target_core_base.h>
32 #include <target/target_core_backend.h>
33 #include <target/target_core_fabric.h>
34 
35 #include "target_core_internal.h"
36 #include "target_core_ua.h"
37 #include "target_core_alua.h"
38 
39 static sense_reason_t
40 sbc_emulate_readcapacity(struct se_cmd *cmd)
41 {
42 	struct se_device *dev = cmd->se_dev;
43 	unsigned char *cdb = cmd->t_task_cdb;
44 	unsigned long long blocks_long = dev->transport->get_blocks(dev);
45 	unsigned char *rbuf;
46 	unsigned char buf[8];
47 	u32 blocks;
48 
49 	/*
50 	 * SBC-2 says:
51 	 *   If the PMI bit is set to zero and the LOGICAL BLOCK
52 	 *   ADDRESS field is not set to zero, the device server shall
53 	 *   terminate the command with CHECK CONDITION status with
54 	 *   the sense key set to ILLEGAL REQUEST and the additional
55 	 *   sense code set to INVALID FIELD IN CDB.
56 	 *
57 	 * In SBC-3, these fields are obsolete, but some SCSI
58 	 * compliance tests actually check this, so we might as well
59 	 * follow SBC-2.
60 	 */
61 	if (!(cdb[8] & 1) && !!(cdb[2] | cdb[3] | cdb[4] | cdb[5]))
62 		return TCM_INVALID_CDB_FIELD;
63 
64 	if (blocks_long >= 0x00000000ffffffff)
65 		blocks = 0xffffffff;
66 	else
67 		blocks = (u32)blocks_long;
68 
69 	buf[0] = (blocks >> 24) & 0xff;
70 	buf[1] = (blocks >> 16) & 0xff;
71 	buf[2] = (blocks >> 8) & 0xff;
72 	buf[3] = blocks & 0xff;
73 	buf[4] = (dev->dev_attrib.block_size >> 24) & 0xff;
74 	buf[5] = (dev->dev_attrib.block_size >> 16) & 0xff;
75 	buf[6] = (dev->dev_attrib.block_size >> 8) & 0xff;
76 	buf[7] = dev->dev_attrib.block_size & 0xff;
77 
78 	rbuf = transport_kmap_data_sg(cmd);
79 	if (rbuf) {
80 		memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length));
81 		transport_kunmap_data_sg(cmd);
82 	}
83 
84 	target_complete_cmd(cmd, GOOD);
85 	return 0;
86 }
87 
88 static sense_reason_t
89 sbc_emulate_readcapacity_16(struct se_cmd *cmd)
90 {
91 	struct se_device *dev = cmd->se_dev;
92 	unsigned char *rbuf;
93 	unsigned char buf[32];
94 	unsigned long long blocks = dev->transport->get_blocks(dev);
95 
96 	memset(buf, 0, sizeof(buf));
97 	buf[0] = (blocks >> 56) & 0xff;
98 	buf[1] = (blocks >> 48) & 0xff;
99 	buf[2] = (blocks >> 40) & 0xff;
100 	buf[3] = (blocks >> 32) & 0xff;
101 	buf[4] = (blocks >> 24) & 0xff;
102 	buf[5] = (blocks >> 16) & 0xff;
103 	buf[6] = (blocks >> 8) & 0xff;
104 	buf[7] = blocks & 0xff;
105 	buf[8] = (dev->dev_attrib.block_size >> 24) & 0xff;
106 	buf[9] = (dev->dev_attrib.block_size >> 16) & 0xff;
107 	buf[10] = (dev->dev_attrib.block_size >> 8) & 0xff;
108 	buf[11] = dev->dev_attrib.block_size & 0xff;
109 	/*
110 	 * Set P_TYPE and PROT_EN bits for DIF support
111 	 */
112 	if (dev->dev_attrib.pi_prot_type)
113 		buf[12] = (dev->dev_attrib.pi_prot_type - 1) << 1 | 0x1;
114 
115 	if (dev->transport->get_lbppbe)
116 		buf[13] = dev->transport->get_lbppbe(dev) & 0x0f;
117 
118 	if (dev->transport->get_alignment_offset_lbas) {
119 		u16 lalba = dev->transport->get_alignment_offset_lbas(dev);
120 		buf[14] = (lalba >> 8) & 0x3f;
121 		buf[15] = lalba & 0xff;
122 	}
123 
124 	/*
125 	 * Set Thin Provisioning Enable bit following sbc3r22 in section
126 	 * READ CAPACITY (16) byte 14 if emulate_tpu or emulate_tpws is enabled.
127 	 */
128 	if (dev->dev_attrib.emulate_tpu || dev->dev_attrib.emulate_tpws)
129 		buf[14] |= 0x80;
130 
131 	rbuf = transport_kmap_data_sg(cmd);
132 	if (rbuf) {
133 		memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length));
134 		transport_kunmap_data_sg(cmd);
135 	}
136 
137 	target_complete_cmd(cmd, GOOD);
138 	return 0;
139 }
140 
141 sector_t sbc_get_write_same_sectors(struct se_cmd *cmd)
142 {
143 	u32 num_blocks;
144 
145 	if (cmd->t_task_cdb[0] == WRITE_SAME)
146 		num_blocks = get_unaligned_be16(&cmd->t_task_cdb[7]);
147 	else if (cmd->t_task_cdb[0] == WRITE_SAME_16)
148 		num_blocks = get_unaligned_be32(&cmd->t_task_cdb[10]);
149 	else /* WRITE_SAME_32 via VARIABLE_LENGTH_CMD */
150 		num_blocks = get_unaligned_be32(&cmd->t_task_cdb[28]);
151 
152 	/*
153 	 * Use the explicit range when non zero is supplied, otherwise calculate
154 	 * the remaining range based on ->get_blocks() - starting LBA.
155 	 */
156 	if (num_blocks)
157 		return num_blocks;
158 
159 	return cmd->se_dev->transport->get_blocks(cmd->se_dev) -
160 		cmd->t_task_lba + 1;
161 }
162 EXPORT_SYMBOL(sbc_get_write_same_sectors);
163 
164 static sense_reason_t
165 sbc_emulate_noop(struct se_cmd *cmd)
166 {
167 	target_complete_cmd(cmd, GOOD);
168 	return 0;
169 }
170 
171 static inline u32 sbc_get_size(struct se_cmd *cmd, u32 sectors)
172 {
173 	return cmd->se_dev->dev_attrib.block_size * sectors;
174 }
175 
176 static int sbc_check_valid_sectors(struct se_cmd *cmd)
177 {
178 	struct se_device *dev = cmd->se_dev;
179 	unsigned long long end_lba;
180 	u32 sectors;
181 
182 	sectors = cmd->data_length / dev->dev_attrib.block_size;
183 	end_lba = dev->transport->get_blocks(dev) + 1;
184 
185 	if (cmd->t_task_lba + sectors > end_lba) {
186 		pr_err("target: lba %llu, sectors %u exceeds end lba %llu\n",
187 			cmd->t_task_lba, sectors, end_lba);
188 		return -EINVAL;
189 	}
190 
191 	return 0;
192 }
193 
194 static inline u32 transport_get_sectors_6(unsigned char *cdb)
195 {
196 	/*
197 	 * Use 8-bit sector value.  SBC-3 says:
198 	 *
199 	 *   A TRANSFER LENGTH field set to zero specifies that 256
200 	 *   logical blocks shall be written.  Any other value
201 	 *   specifies the number of logical blocks that shall be
202 	 *   written.
203 	 */
204 	return cdb[4] ? : 256;
205 }
206 
207 static inline u32 transport_get_sectors_10(unsigned char *cdb)
208 {
209 	return (u32)(cdb[7] << 8) + cdb[8];
210 }
211 
212 static inline u32 transport_get_sectors_12(unsigned char *cdb)
213 {
214 	return (u32)(cdb[6] << 24) + (cdb[7] << 16) + (cdb[8] << 8) + cdb[9];
215 }
216 
217 static inline u32 transport_get_sectors_16(unsigned char *cdb)
218 {
219 	return (u32)(cdb[10] << 24) + (cdb[11] << 16) +
220 		    (cdb[12] << 8) + cdb[13];
221 }
222 
223 /*
224  * Used for VARIABLE_LENGTH_CDB WRITE_32 and READ_32 variants
225  */
226 static inline u32 transport_get_sectors_32(unsigned char *cdb)
227 {
228 	return (u32)(cdb[28] << 24) + (cdb[29] << 16) +
229 		    (cdb[30] << 8) + cdb[31];
230 
231 }
232 
233 static inline u32 transport_lba_21(unsigned char *cdb)
234 {
235 	return ((cdb[1] & 0x1f) << 16) | (cdb[2] << 8) | cdb[3];
236 }
237 
238 static inline u32 transport_lba_32(unsigned char *cdb)
239 {
240 	return (cdb[2] << 24) | (cdb[3] << 16) | (cdb[4] << 8) | cdb[5];
241 }
242 
243 static inline unsigned long long transport_lba_64(unsigned char *cdb)
244 {
245 	unsigned int __v1, __v2;
246 
247 	__v1 = (cdb[2] << 24) | (cdb[3] << 16) | (cdb[4] << 8) | cdb[5];
248 	__v2 = (cdb[6] << 24) | (cdb[7] << 16) | (cdb[8] << 8) | cdb[9];
249 
250 	return ((unsigned long long)__v2) | (unsigned long long)__v1 << 32;
251 }
252 
253 /*
254  * For VARIABLE_LENGTH_CDB w/ 32 byte extended CDBs
255  */
256 static inline unsigned long long transport_lba_64_ext(unsigned char *cdb)
257 {
258 	unsigned int __v1, __v2;
259 
260 	__v1 = (cdb[12] << 24) | (cdb[13] << 16) | (cdb[14] << 8) | cdb[15];
261 	__v2 = (cdb[16] << 24) | (cdb[17] << 16) | (cdb[18] << 8) | cdb[19];
262 
263 	return ((unsigned long long)__v2) | (unsigned long long)__v1 << 32;
264 }
265 
266 static sense_reason_t
267 sbc_setup_write_same(struct se_cmd *cmd, unsigned char *flags, struct sbc_ops *ops)
268 {
269 	unsigned int sectors = sbc_get_write_same_sectors(cmd);
270 
271 	if ((flags[0] & 0x04) || (flags[0] & 0x02)) {
272 		pr_err("WRITE_SAME PBDATA and LBDATA"
273 			" bits not supported for Block Discard"
274 			" Emulation\n");
275 		return TCM_UNSUPPORTED_SCSI_OPCODE;
276 	}
277 	if (sectors > cmd->se_dev->dev_attrib.max_write_same_len) {
278 		pr_warn("WRITE_SAME sectors: %u exceeds max_write_same_len: %u\n",
279 			sectors, cmd->se_dev->dev_attrib.max_write_same_len);
280 		return TCM_INVALID_CDB_FIELD;
281 	}
282 	/* We always have ANC_SUP == 0 so setting ANCHOR is always an error */
283 	if (flags[0] & 0x10) {
284 		pr_warn("WRITE SAME with ANCHOR not supported\n");
285 		return TCM_INVALID_CDB_FIELD;
286 	}
287 	/*
288 	 * Special case for WRITE_SAME w/ UNMAP=1 that ends up getting
289 	 * translated into block discard requests within backend code.
290 	 */
291 	if (flags[0] & 0x08) {
292 		if (!ops->execute_write_same_unmap)
293 			return TCM_UNSUPPORTED_SCSI_OPCODE;
294 
295 		cmd->execute_cmd = ops->execute_write_same_unmap;
296 		return 0;
297 	}
298 	if (!ops->execute_write_same)
299 		return TCM_UNSUPPORTED_SCSI_OPCODE;
300 
301 	cmd->execute_cmd = ops->execute_write_same;
302 	return 0;
303 }
304 
305 static sense_reason_t xdreadwrite_callback(struct se_cmd *cmd)
306 {
307 	unsigned char *buf, *addr;
308 	struct scatterlist *sg;
309 	unsigned int offset;
310 	sense_reason_t ret = TCM_NO_SENSE;
311 	int i, count;
312 	/*
313 	 * From sbc3r22.pdf section 5.48 XDWRITEREAD (10) command
314 	 *
315 	 * 1) read the specified logical block(s);
316 	 * 2) transfer logical blocks from the data-out buffer;
317 	 * 3) XOR the logical blocks transferred from the data-out buffer with
318 	 *    the logical blocks read, storing the resulting XOR data in a buffer;
319 	 * 4) if the DISABLE WRITE bit is set to zero, then write the logical
320 	 *    blocks transferred from the data-out buffer; and
321 	 * 5) transfer the resulting XOR data to the data-in buffer.
322 	 */
323 	buf = kmalloc(cmd->data_length, GFP_KERNEL);
324 	if (!buf) {
325 		pr_err("Unable to allocate xor_callback buf\n");
326 		return TCM_OUT_OF_RESOURCES;
327 	}
328 	/*
329 	 * Copy the scatterlist WRITE buffer located at cmd->t_data_sg
330 	 * into the locally allocated *buf
331 	 */
332 	sg_copy_to_buffer(cmd->t_data_sg,
333 			  cmd->t_data_nents,
334 			  buf,
335 			  cmd->data_length);
336 
337 	/*
338 	 * Now perform the XOR against the BIDI read memory located at
339 	 * cmd->t_mem_bidi_list
340 	 */
341 
342 	offset = 0;
343 	for_each_sg(cmd->t_bidi_data_sg, sg, cmd->t_bidi_data_nents, count) {
344 		addr = kmap_atomic(sg_page(sg));
345 		if (!addr) {
346 			ret = TCM_OUT_OF_RESOURCES;
347 			goto out;
348 		}
349 
350 		for (i = 0; i < sg->length; i++)
351 			*(addr + sg->offset + i) ^= *(buf + offset + i);
352 
353 		offset += sg->length;
354 		kunmap_atomic(addr);
355 	}
356 
357 out:
358 	kfree(buf);
359 	return ret;
360 }
361 
362 static sense_reason_t
363 sbc_execute_rw(struct se_cmd *cmd)
364 {
365 	return cmd->execute_rw(cmd, cmd->t_data_sg, cmd->t_data_nents,
366 			       cmd->data_direction);
367 }
368 
369 static sense_reason_t compare_and_write_post(struct se_cmd *cmd)
370 {
371 	struct se_device *dev = cmd->se_dev;
372 
373 	/*
374 	 * Only set SCF_COMPARE_AND_WRITE_POST to force a response fall-through
375 	 * within target_complete_ok_work() if the command was successfully
376 	 * sent to the backend driver.
377 	 */
378 	spin_lock_irq(&cmd->t_state_lock);
379 	if ((cmd->transport_state & CMD_T_SENT) && !cmd->scsi_status)
380 		cmd->se_cmd_flags |= SCF_COMPARE_AND_WRITE_POST;
381 	spin_unlock_irq(&cmd->t_state_lock);
382 
383 	/*
384 	 * Unlock ->caw_sem originally obtained during sbc_compare_and_write()
385 	 * before the original READ I/O submission.
386 	 */
387 	up(&dev->caw_sem);
388 
389 	return TCM_NO_SENSE;
390 }
391 
392 static sense_reason_t compare_and_write_callback(struct se_cmd *cmd)
393 {
394 	struct se_device *dev = cmd->se_dev;
395 	struct scatterlist *write_sg = NULL, *sg;
396 	unsigned char *buf = NULL, *addr;
397 	struct sg_mapping_iter m;
398 	unsigned int offset = 0, len;
399 	unsigned int nlbas = cmd->t_task_nolb;
400 	unsigned int block_size = dev->dev_attrib.block_size;
401 	unsigned int compare_len = (nlbas * block_size);
402 	sense_reason_t ret = TCM_NO_SENSE;
403 	int rc, i;
404 
405 	/*
406 	 * Handle early failure in transport_generic_request_failure(),
407 	 * which will not have taken ->caw_mutex yet..
408 	 */
409 	if (!cmd->t_data_sg || !cmd->t_bidi_data_sg)
410 		return TCM_NO_SENSE;
411 	/*
412 	 * Immediately exit + release dev->caw_sem if command has already
413 	 * been failed with a non-zero SCSI status.
414 	 */
415 	if (cmd->scsi_status) {
416 		pr_err("compare_and_write_callback: non zero scsi_status:"
417 			" 0x%02x\n", cmd->scsi_status);
418 		goto out;
419 	}
420 
421 	buf = kzalloc(cmd->data_length, GFP_KERNEL);
422 	if (!buf) {
423 		pr_err("Unable to allocate compare_and_write buf\n");
424 		ret = TCM_OUT_OF_RESOURCES;
425 		goto out;
426 	}
427 
428 	write_sg = kzalloc(sizeof(struct scatterlist) * cmd->t_data_nents,
429 			   GFP_KERNEL);
430 	if (!write_sg) {
431 		pr_err("Unable to allocate compare_and_write sg\n");
432 		ret = TCM_OUT_OF_RESOURCES;
433 		goto out;
434 	}
435 	/*
436 	 * Setup verify and write data payloads from total NumberLBAs.
437 	 */
438 	rc = sg_copy_to_buffer(cmd->t_data_sg, cmd->t_data_nents, buf,
439 			       cmd->data_length);
440 	if (!rc) {
441 		pr_err("sg_copy_to_buffer() failed for compare_and_write\n");
442 		ret = TCM_OUT_OF_RESOURCES;
443 		goto out;
444 	}
445 	/*
446 	 * Compare against SCSI READ payload against verify payload
447 	 */
448 	for_each_sg(cmd->t_bidi_data_sg, sg, cmd->t_bidi_data_nents, i) {
449 		addr = (unsigned char *)kmap_atomic(sg_page(sg));
450 		if (!addr) {
451 			ret = TCM_OUT_OF_RESOURCES;
452 			goto out;
453 		}
454 
455 		len = min(sg->length, compare_len);
456 
457 		if (memcmp(addr, buf + offset, len)) {
458 			pr_warn("Detected MISCOMPARE for addr: %p buf: %p\n",
459 				addr, buf + offset);
460 			kunmap_atomic(addr);
461 			goto miscompare;
462 		}
463 		kunmap_atomic(addr);
464 
465 		offset += len;
466 		compare_len -= len;
467 		if (!compare_len)
468 			break;
469 	}
470 
471 	i = 0;
472 	len = cmd->t_task_nolb * block_size;
473 	sg_miter_start(&m, cmd->t_data_sg, cmd->t_data_nents, SG_MITER_TO_SG);
474 	/*
475 	 * Currently assumes NoLB=1 and SGLs are PAGE_SIZE..
476 	 */
477 	while (len) {
478 		sg_miter_next(&m);
479 
480 		if (block_size < PAGE_SIZE) {
481 			sg_set_page(&write_sg[i], m.page, block_size,
482 				    block_size);
483 		} else {
484 			sg_miter_next(&m);
485 			sg_set_page(&write_sg[i], m.page, block_size,
486 				    0);
487 		}
488 		len -= block_size;
489 		i++;
490 	}
491 	sg_miter_stop(&m);
492 	/*
493 	 * Save the original SGL + nents values before updating to new
494 	 * assignments, to be released in transport_free_pages() ->
495 	 * transport_reset_sgl_orig()
496 	 */
497 	cmd->t_data_sg_orig = cmd->t_data_sg;
498 	cmd->t_data_sg = write_sg;
499 	cmd->t_data_nents_orig = cmd->t_data_nents;
500 	cmd->t_data_nents = 1;
501 
502 	cmd->sam_task_attr = MSG_HEAD_TAG;
503 	cmd->transport_complete_callback = compare_and_write_post;
504 	/*
505 	 * Now reset ->execute_cmd() to the normal sbc_execute_rw() handler
506 	 * for submitting the adjusted SGL to write instance user-data.
507 	 */
508 	cmd->execute_cmd = sbc_execute_rw;
509 
510 	spin_lock_irq(&cmd->t_state_lock);
511 	cmd->t_state = TRANSPORT_PROCESSING;
512 	cmd->transport_state |= CMD_T_ACTIVE|CMD_T_BUSY|CMD_T_SENT;
513 	spin_unlock_irq(&cmd->t_state_lock);
514 
515 	__target_execute_cmd(cmd);
516 
517 	kfree(buf);
518 	return ret;
519 
520 miscompare:
521 	pr_warn("Target/%s: Send MISCOMPARE check condition and sense\n",
522 		dev->transport->name);
523 	ret = TCM_MISCOMPARE_VERIFY;
524 out:
525 	/*
526 	 * In the MISCOMPARE or failure case, unlock ->caw_sem obtained in
527 	 * sbc_compare_and_write() before the original READ I/O submission.
528 	 */
529 	up(&dev->caw_sem);
530 	kfree(write_sg);
531 	kfree(buf);
532 	return ret;
533 }
534 
535 static sense_reason_t
536 sbc_compare_and_write(struct se_cmd *cmd)
537 {
538 	struct se_device *dev = cmd->se_dev;
539 	sense_reason_t ret;
540 	int rc;
541 	/*
542 	 * Submit the READ first for COMPARE_AND_WRITE to perform the
543 	 * comparision using SGLs at cmd->t_bidi_data_sg..
544 	 */
545 	rc = down_interruptible(&dev->caw_sem);
546 	if ((rc != 0) || signal_pending(current)) {
547 		cmd->transport_complete_callback = NULL;
548 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
549 	}
550 	/*
551 	 * Reset cmd->data_length to individual block_size in order to not
552 	 * confuse backend drivers that depend on this value matching the
553 	 * size of the I/O being submitted.
554 	 */
555 	cmd->data_length = cmd->t_task_nolb * dev->dev_attrib.block_size;
556 
557 	ret = cmd->execute_rw(cmd, cmd->t_bidi_data_sg, cmd->t_bidi_data_nents,
558 			      DMA_FROM_DEVICE);
559 	if (ret) {
560 		cmd->transport_complete_callback = NULL;
561 		up(&dev->caw_sem);
562 		return ret;
563 	}
564 	/*
565 	 * Unlock of dev->caw_sem to occur in compare_and_write_callback()
566 	 * upon MISCOMPARE, or in compare_and_write_done() upon completion
567 	 * of WRITE instance user-data.
568 	 */
569 	return TCM_NO_SENSE;
570 }
571 
572 static bool
573 sbc_check_prot(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb,
574 	       u32 sectors)
575 {
576 	if (!cmd->t_prot_sg || !cmd->t_prot_nents)
577 		return true;
578 
579 	switch (dev->dev_attrib.pi_prot_type) {
580 	case TARGET_DIF_TYPE3_PROT:
581 		if (!(cdb[1] & 0xe0))
582 			return true;
583 
584 		cmd->reftag_seed = 0xffffffff;
585 		break;
586 	case TARGET_DIF_TYPE2_PROT:
587 		if (cdb[1] & 0xe0)
588 			return false;
589 
590 		cmd->reftag_seed = cmd->t_task_lba;
591 		break;
592 	case TARGET_DIF_TYPE1_PROT:
593 		if (!(cdb[1] & 0xe0))
594 			return true;
595 
596 		cmd->reftag_seed = cmd->t_task_lba;
597 		break;
598 	case TARGET_DIF_TYPE0_PROT:
599 	default:
600 		return true;
601 	}
602 
603 	cmd->prot_type = dev->dev_attrib.pi_prot_type;
604 	cmd->prot_length = dev->prot_length * sectors;
605 	cmd->prot_handover = PROT_SEPERATED;
606 
607 	return true;
608 }
609 
610 sense_reason_t
611 sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
612 {
613 	struct se_device *dev = cmd->se_dev;
614 	unsigned char *cdb = cmd->t_task_cdb;
615 	unsigned int size;
616 	u32 sectors = 0;
617 	sense_reason_t ret;
618 
619 	switch (cdb[0]) {
620 	case READ_6:
621 		sectors = transport_get_sectors_6(cdb);
622 		cmd->t_task_lba = transport_lba_21(cdb);
623 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
624 		cmd->execute_rw = ops->execute_rw;
625 		cmd->execute_cmd = sbc_execute_rw;
626 		break;
627 	case READ_10:
628 		sectors = transport_get_sectors_10(cdb);
629 		cmd->t_task_lba = transport_lba_32(cdb);
630 
631 		if (!sbc_check_prot(dev, cmd, cdb, sectors))
632 			return TCM_UNSUPPORTED_SCSI_OPCODE;
633 
634 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
635 		cmd->execute_rw = ops->execute_rw;
636 		cmd->execute_cmd = sbc_execute_rw;
637 		break;
638 	case READ_12:
639 		sectors = transport_get_sectors_12(cdb);
640 		cmd->t_task_lba = transport_lba_32(cdb);
641 
642 		if (!sbc_check_prot(dev, cmd, cdb, sectors))
643 			return TCM_UNSUPPORTED_SCSI_OPCODE;
644 
645 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
646 		cmd->execute_rw = ops->execute_rw;
647 		cmd->execute_cmd = sbc_execute_rw;
648 		break;
649 	case READ_16:
650 		sectors = transport_get_sectors_16(cdb);
651 		cmd->t_task_lba = transport_lba_64(cdb);
652 
653 		if (!sbc_check_prot(dev, cmd, cdb, sectors))
654 			return TCM_UNSUPPORTED_SCSI_OPCODE;
655 
656 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
657 		cmd->execute_rw = ops->execute_rw;
658 		cmd->execute_cmd = sbc_execute_rw;
659 		break;
660 	case WRITE_6:
661 		sectors = transport_get_sectors_6(cdb);
662 		cmd->t_task_lba = transport_lba_21(cdb);
663 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
664 		cmd->execute_rw = ops->execute_rw;
665 		cmd->execute_cmd = sbc_execute_rw;
666 		break;
667 	case WRITE_10:
668 	case WRITE_VERIFY:
669 		sectors = transport_get_sectors_10(cdb);
670 		cmd->t_task_lba = transport_lba_32(cdb);
671 
672 		if (!sbc_check_prot(dev, cmd, cdb, sectors))
673 			return TCM_UNSUPPORTED_SCSI_OPCODE;
674 
675 		if (cdb[1] & 0x8)
676 			cmd->se_cmd_flags |= SCF_FUA;
677 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
678 		cmd->execute_rw = ops->execute_rw;
679 		cmd->execute_cmd = sbc_execute_rw;
680 		break;
681 	case WRITE_12:
682 		sectors = transport_get_sectors_12(cdb);
683 		cmd->t_task_lba = transport_lba_32(cdb);
684 
685 		if (!sbc_check_prot(dev, cmd, cdb, sectors))
686 			return TCM_UNSUPPORTED_SCSI_OPCODE;
687 
688 		if (cdb[1] & 0x8)
689 			cmd->se_cmd_flags |= SCF_FUA;
690 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
691 		cmd->execute_rw = ops->execute_rw;
692 		cmd->execute_cmd = sbc_execute_rw;
693 		break;
694 	case WRITE_16:
695 		sectors = transport_get_sectors_16(cdb);
696 		cmd->t_task_lba = transport_lba_64(cdb);
697 
698 		if (!sbc_check_prot(dev, cmd, cdb, sectors))
699 			return TCM_UNSUPPORTED_SCSI_OPCODE;
700 
701 		if (cdb[1] & 0x8)
702 			cmd->se_cmd_flags |= SCF_FUA;
703 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
704 		cmd->execute_rw = ops->execute_rw;
705 		cmd->execute_cmd = sbc_execute_rw;
706 		break;
707 	case XDWRITEREAD_10:
708 		if (cmd->data_direction != DMA_TO_DEVICE ||
709 		    !(cmd->se_cmd_flags & SCF_BIDI))
710 			return TCM_INVALID_CDB_FIELD;
711 		sectors = transport_get_sectors_10(cdb);
712 
713 		cmd->t_task_lba = transport_lba_32(cdb);
714 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
715 
716 		/*
717 		 * Setup BIDI XOR callback to be run after I/O completion.
718 		 */
719 		cmd->execute_rw = ops->execute_rw;
720 		cmd->execute_cmd = sbc_execute_rw;
721 		cmd->transport_complete_callback = &xdreadwrite_callback;
722 		if (cdb[1] & 0x8)
723 			cmd->se_cmd_flags |= SCF_FUA;
724 		break;
725 	case VARIABLE_LENGTH_CMD:
726 	{
727 		u16 service_action = get_unaligned_be16(&cdb[8]);
728 		switch (service_action) {
729 		case XDWRITEREAD_32:
730 			sectors = transport_get_sectors_32(cdb);
731 
732 			/*
733 			 * Use WRITE_32 and READ_32 opcodes for the emulated
734 			 * XDWRITE_READ_32 logic.
735 			 */
736 			cmd->t_task_lba = transport_lba_64_ext(cdb);
737 			cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
738 
739 			/*
740 			 * Setup BIDI XOR callback to be run during after I/O
741 			 * completion.
742 			 */
743 			cmd->execute_rw = ops->execute_rw;
744 			cmd->execute_cmd = sbc_execute_rw;
745 			cmd->transport_complete_callback = &xdreadwrite_callback;
746 			if (cdb[1] & 0x8)
747 				cmd->se_cmd_flags |= SCF_FUA;
748 			break;
749 		case WRITE_SAME_32:
750 			sectors = transport_get_sectors_32(cdb);
751 			if (!sectors) {
752 				pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not"
753 				       " supported\n");
754 				return TCM_INVALID_CDB_FIELD;
755 			}
756 
757 			size = sbc_get_size(cmd, 1);
758 			cmd->t_task_lba = get_unaligned_be64(&cdb[12]);
759 
760 			ret = sbc_setup_write_same(cmd, &cdb[10], ops);
761 			if (ret)
762 				return ret;
763 			break;
764 		default:
765 			pr_err("VARIABLE_LENGTH_CMD service action"
766 				" 0x%04x not supported\n", service_action);
767 			return TCM_UNSUPPORTED_SCSI_OPCODE;
768 		}
769 		break;
770 	}
771 	case COMPARE_AND_WRITE:
772 		sectors = cdb[13];
773 		/*
774 		 * Currently enforce COMPARE_AND_WRITE for a single sector
775 		 */
776 		if (sectors > 1) {
777 			pr_err("COMPARE_AND_WRITE contains NoLB: %u greater"
778 			       " than 1\n", sectors);
779 			return TCM_INVALID_CDB_FIELD;
780 		}
781 		/*
782 		 * Double size because we have two buffers, note that
783 		 * zero is not an error..
784 		 */
785 		size = 2 * sbc_get_size(cmd, sectors);
786 		cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
787 		cmd->t_task_nolb = sectors;
788 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB | SCF_COMPARE_AND_WRITE;
789 		cmd->execute_rw = ops->execute_rw;
790 		cmd->execute_cmd = sbc_compare_and_write;
791 		cmd->transport_complete_callback = compare_and_write_callback;
792 		break;
793 	case READ_CAPACITY:
794 		size = READ_CAP_LEN;
795 		cmd->execute_cmd = sbc_emulate_readcapacity;
796 		break;
797 	case SERVICE_ACTION_IN:
798 		switch (cmd->t_task_cdb[1] & 0x1f) {
799 		case SAI_READ_CAPACITY_16:
800 			cmd->execute_cmd = sbc_emulate_readcapacity_16;
801 			break;
802 		case SAI_REPORT_REFERRALS:
803 			cmd->execute_cmd = target_emulate_report_referrals;
804 			break;
805 		default:
806 			pr_err("Unsupported SA: 0x%02x\n",
807 				cmd->t_task_cdb[1] & 0x1f);
808 			return TCM_INVALID_CDB_FIELD;
809 		}
810 		size = (cdb[10] << 24) | (cdb[11] << 16) |
811 		       (cdb[12] << 8) | cdb[13];
812 		break;
813 	case SYNCHRONIZE_CACHE:
814 	case SYNCHRONIZE_CACHE_16:
815 		if (!ops->execute_sync_cache) {
816 			size = 0;
817 			cmd->execute_cmd = sbc_emulate_noop;
818 			break;
819 		}
820 
821 		/*
822 		 * Extract LBA and range to be flushed for emulated SYNCHRONIZE_CACHE
823 		 */
824 		if (cdb[0] == SYNCHRONIZE_CACHE) {
825 			sectors = transport_get_sectors_10(cdb);
826 			cmd->t_task_lba = transport_lba_32(cdb);
827 		} else {
828 			sectors = transport_get_sectors_16(cdb);
829 			cmd->t_task_lba = transport_lba_64(cdb);
830 		}
831 
832 		size = sbc_get_size(cmd, sectors);
833 
834 		/*
835 		 * Check to ensure that LBA + Range does not exceed past end of
836 		 * device for IBLOCK and FILEIO ->do_sync_cache() backend calls
837 		 */
838 		if (cmd->t_task_lba || sectors) {
839 			if (sbc_check_valid_sectors(cmd) < 0)
840 				return TCM_ADDRESS_OUT_OF_RANGE;
841 		}
842 		cmd->execute_cmd = ops->execute_sync_cache;
843 		break;
844 	case UNMAP:
845 		if (!ops->execute_unmap)
846 			return TCM_UNSUPPORTED_SCSI_OPCODE;
847 
848 		size = get_unaligned_be16(&cdb[7]);
849 		cmd->execute_cmd = ops->execute_unmap;
850 		break;
851 	case WRITE_SAME_16:
852 		sectors = transport_get_sectors_16(cdb);
853 		if (!sectors) {
854 			pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
855 			return TCM_INVALID_CDB_FIELD;
856 		}
857 
858 		size = sbc_get_size(cmd, 1);
859 		cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
860 
861 		ret = sbc_setup_write_same(cmd, &cdb[1], ops);
862 		if (ret)
863 			return ret;
864 		break;
865 	case WRITE_SAME:
866 		sectors = transport_get_sectors_10(cdb);
867 		if (!sectors) {
868 			pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
869 			return TCM_INVALID_CDB_FIELD;
870 		}
871 
872 		size = sbc_get_size(cmd, 1);
873 		cmd->t_task_lba = get_unaligned_be32(&cdb[2]);
874 
875 		/*
876 		 * Follow sbcr26 with WRITE_SAME (10) and check for the existence
877 		 * of byte 1 bit 3 UNMAP instead of original reserved field
878 		 */
879 		ret = sbc_setup_write_same(cmd, &cdb[1], ops);
880 		if (ret)
881 			return ret;
882 		break;
883 	case VERIFY:
884 		size = 0;
885 		cmd->execute_cmd = sbc_emulate_noop;
886 		break;
887 	case REZERO_UNIT:
888 	case SEEK_6:
889 	case SEEK_10:
890 		/*
891 		 * There are still clients out there which use these old SCSI-2
892 		 * commands. This mainly happens when running VMs with legacy
893 		 * guest systems, connected via SCSI command pass-through to
894 		 * iSCSI targets. Make them happy and return status GOOD.
895 		 */
896 		size = 0;
897 		cmd->execute_cmd = sbc_emulate_noop;
898 		break;
899 	default:
900 		ret = spc_parse_cdb(cmd, &size);
901 		if (ret)
902 			return ret;
903 	}
904 
905 	/* reject any command that we don't have a handler for */
906 	if (!(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) && !cmd->execute_cmd)
907 		return TCM_UNSUPPORTED_SCSI_OPCODE;
908 
909 	if (cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
910 		unsigned long long end_lba;
911 
912 		if (sectors > dev->dev_attrib.fabric_max_sectors) {
913 			printk_ratelimited(KERN_ERR "SCSI OP %02xh with too"
914 				" big sectors %u exceeds fabric_max_sectors:"
915 				" %u\n", cdb[0], sectors,
916 				dev->dev_attrib.fabric_max_sectors);
917 			return TCM_INVALID_CDB_FIELD;
918 		}
919 		if (sectors > dev->dev_attrib.hw_max_sectors) {
920 			printk_ratelimited(KERN_ERR "SCSI OP %02xh with too"
921 				" big sectors %u exceeds backend hw_max_sectors:"
922 				" %u\n", cdb[0], sectors,
923 				dev->dev_attrib.hw_max_sectors);
924 			return TCM_INVALID_CDB_FIELD;
925 		}
926 
927 		end_lba = dev->transport->get_blocks(dev) + 1;
928 		if (cmd->t_task_lba + sectors > end_lba) {
929 			pr_err("cmd exceeds last lba %llu "
930 				"(lba %llu, sectors %u)\n",
931 				end_lba, cmd->t_task_lba, sectors);
932 			return TCM_ADDRESS_OUT_OF_RANGE;
933 		}
934 
935 		if (!(cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE))
936 			size = sbc_get_size(cmd, sectors);
937 	}
938 
939 	return target_cmd_size_check(cmd, size);
940 }
941 EXPORT_SYMBOL(sbc_parse_cdb);
942 
943 u32 sbc_get_device_type(struct se_device *dev)
944 {
945 	return TYPE_DISK;
946 }
947 EXPORT_SYMBOL(sbc_get_device_type);
948 
949 sense_reason_t
950 sbc_execute_unmap(struct se_cmd *cmd,
951 	sense_reason_t (*do_unmap_fn)(struct se_cmd *, void *,
952 				      sector_t, sector_t),
953 	void *priv)
954 {
955 	struct se_device *dev = cmd->se_dev;
956 	unsigned char *buf, *ptr = NULL;
957 	sector_t lba;
958 	int size;
959 	u32 range;
960 	sense_reason_t ret = 0;
961 	int dl, bd_dl;
962 
963 	/* We never set ANC_SUP */
964 	if (cmd->t_task_cdb[1])
965 		return TCM_INVALID_CDB_FIELD;
966 
967 	if (cmd->data_length == 0) {
968 		target_complete_cmd(cmd, SAM_STAT_GOOD);
969 		return 0;
970 	}
971 
972 	if (cmd->data_length < 8) {
973 		pr_warn("UNMAP parameter list length %u too small\n",
974 			cmd->data_length);
975 		return TCM_PARAMETER_LIST_LENGTH_ERROR;
976 	}
977 
978 	buf = transport_kmap_data_sg(cmd);
979 	if (!buf)
980 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
981 
982 	dl = get_unaligned_be16(&buf[0]);
983 	bd_dl = get_unaligned_be16(&buf[2]);
984 
985 	size = cmd->data_length - 8;
986 	if (bd_dl > size)
987 		pr_warn("UNMAP parameter list length %u too small, ignoring bd_dl %u\n",
988 			cmd->data_length, bd_dl);
989 	else
990 		size = bd_dl;
991 
992 	if (size / 16 > dev->dev_attrib.max_unmap_block_desc_count) {
993 		ret = TCM_INVALID_PARAMETER_LIST;
994 		goto err;
995 	}
996 
997 	/* First UNMAP block descriptor starts at 8 byte offset */
998 	ptr = &buf[8];
999 	pr_debug("UNMAP: Sub: %s Using dl: %u bd_dl: %u size: %u"
1000 		" ptr: %p\n", dev->transport->name, dl, bd_dl, size, ptr);
1001 
1002 	while (size >= 16) {
1003 		lba = get_unaligned_be64(&ptr[0]);
1004 		range = get_unaligned_be32(&ptr[8]);
1005 		pr_debug("UNMAP: Using lba: %llu and range: %u\n",
1006 				 (unsigned long long)lba, range);
1007 
1008 		if (range > dev->dev_attrib.max_unmap_lba_count) {
1009 			ret = TCM_INVALID_PARAMETER_LIST;
1010 			goto err;
1011 		}
1012 
1013 		if (lba + range > dev->transport->get_blocks(dev) + 1) {
1014 			ret = TCM_ADDRESS_OUT_OF_RANGE;
1015 			goto err;
1016 		}
1017 
1018 		ret = do_unmap_fn(cmd, priv, lba, range);
1019 		if (ret)
1020 			goto err;
1021 
1022 		ptr += 16;
1023 		size -= 16;
1024 	}
1025 
1026 err:
1027 	transport_kunmap_data_sg(cmd);
1028 	if (!ret)
1029 		target_complete_cmd(cmd, GOOD);
1030 	return ret;
1031 }
1032 EXPORT_SYMBOL(sbc_execute_unmap);
1033 
1034 static sense_reason_t
1035 sbc_dif_v1_verify(struct se_device *dev, struct se_dif_v1_tuple *sdt,
1036 		  const void *p, sector_t sector, unsigned int ei_lba)
1037 {
1038 	int block_size = dev->dev_attrib.block_size;
1039 	__be16 csum;
1040 
1041 	csum = cpu_to_be16(crc_t10dif(p, block_size));
1042 
1043 	if (sdt->guard_tag != csum) {
1044 		pr_err("DIFv1 checksum failed on sector %llu guard tag 0x%04x"
1045 			" csum 0x%04x\n", (unsigned long long)sector,
1046 			be16_to_cpu(sdt->guard_tag), be16_to_cpu(csum));
1047 		return TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED;
1048 	}
1049 
1050 	if (dev->dev_attrib.pi_prot_type == TARGET_DIF_TYPE1_PROT &&
1051 	    be32_to_cpu(sdt->ref_tag) != (sector & 0xffffffff)) {
1052 		pr_err("DIFv1 Type 1 reference failed on sector: %llu tag: 0x%08x"
1053 		       " sector MSB: 0x%08x\n", (unsigned long long)sector,
1054 		       be32_to_cpu(sdt->ref_tag), (u32)(sector & 0xffffffff));
1055 		return TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;
1056 	}
1057 
1058 	if (dev->dev_attrib.pi_prot_type == TARGET_DIF_TYPE2_PROT &&
1059 	    be32_to_cpu(sdt->ref_tag) != ei_lba) {
1060 		pr_err("DIFv1 Type 2 reference failed on sector: %llu tag: 0x%08x"
1061 		       " ei_lba: 0x%08x\n", (unsigned long long)sector,
1062 			be32_to_cpu(sdt->ref_tag), ei_lba);
1063 		return TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;
1064 	}
1065 
1066 	return 0;
1067 }
1068 
1069 static void
1070 sbc_dif_copy_prot(struct se_cmd *cmd, unsigned int sectors, bool read,
1071 		  struct scatterlist *sg, int sg_off)
1072 {
1073 	struct se_device *dev = cmd->se_dev;
1074 	struct scatterlist *psg;
1075 	void *paddr, *addr;
1076 	unsigned int i, len, left;
1077 
1078 	left = sectors * dev->prot_length;
1079 
1080 	for_each_sg(cmd->t_prot_sg, psg, cmd->t_prot_nents, i) {
1081 
1082 		len = min(psg->length, left);
1083 		paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1084 		addr = kmap_atomic(sg_page(sg)) + sg_off;
1085 
1086 		if (read)
1087 			memcpy(paddr, addr, len);
1088 		else
1089 			memcpy(addr, paddr, len);
1090 
1091 		left -= len;
1092 		kunmap_atomic(paddr);
1093 		kunmap_atomic(addr);
1094 	}
1095 }
1096 
1097 sense_reason_t
1098 sbc_dif_verify_write(struct se_cmd *cmd, sector_t start, unsigned int sectors,
1099 		     unsigned int ei_lba, struct scatterlist *sg, int sg_off)
1100 {
1101 	struct se_device *dev = cmd->se_dev;
1102 	struct se_dif_v1_tuple *sdt;
1103 	struct scatterlist *dsg, *psg = cmd->t_prot_sg;
1104 	sector_t sector = start;
1105 	void *daddr, *paddr;
1106 	int i, j, offset = 0;
1107 	sense_reason_t rc;
1108 
1109 	for_each_sg(cmd->t_data_sg, dsg, cmd->t_data_nents, i) {
1110 		daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1111 		paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1112 
1113 		for (j = 0; j < dsg->length; j += dev->dev_attrib.block_size) {
1114 
1115 			if (offset >= psg->length) {
1116 				kunmap_atomic(paddr);
1117 				psg = sg_next(psg);
1118 				paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1119 				offset = 0;
1120 			}
1121 
1122 			sdt = paddr + offset;
1123 
1124 			pr_debug("DIF WRITE sector: %llu guard_tag: 0x%04x"
1125 				 " app_tag: 0x%04x ref_tag: %u\n",
1126 				 (unsigned long long)sector, sdt->guard_tag,
1127 				 sdt->app_tag, be32_to_cpu(sdt->ref_tag));
1128 
1129 			rc = sbc_dif_v1_verify(dev, sdt, daddr + j, sector,
1130 					       ei_lba);
1131 			if (rc) {
1132 				kunmap_atomic(paddr);
1133 				kunmap_atomic(daddr);
1134 				cmd->bad_sector = sector;
1135 				return rc;
1136 			}
1137 
1138 			sector++;
1139 			ei_lba++;
1140 			offset += sizeof(struct se_dif_v1_tuple);
1141 		}
1142 
1143 		kunmap_atomic(paddr);
1144 		kunmap_atomic(daddr);
1145 	}
1146 	sbc_dif_copy_prot(cmd, sectors, false, sg, sg_off);
1147 
1148 	return 0;
1149 }
1150 EXPORT_SYMBOL(sbc_dif_verify_write);
1151 
1152 sense_reason_t
1153 sbc_dif_verify_read(struct se_cmd *cmd, sector_t start, unsigned int sectors,
1154 		    unsigned int ei_lba, struct scatterlist *sg, int sg_off)
1155 {
1156 	struct se_device *dev = cmd->se_dev;
1157 	struct se_dif_v1_tuple *sdt;
1158 	struct scatterlist *dsg;
1159 	sector_t sector = start;
1160 	void *daddr, *paddr;
1161 	int i, j, offset = sg_off;
1162 	sense_reason_t rc;
1163 
1164 	for_each_sg(cmd->t_data_sg, dsg, cmd->t_data_nents, i) {
1165 		daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1166 		paddr = kmap_atomic(sg_page(sg)) + sg->offset;
1167 
1168 		for (j = 0; j < dsg->length; j += dev->dev_attrib.block_size) {
1169 
1170 			if (offset >= sg->length) {
1171 				kunmap_atomic(paddr);
1172 				sg = sg_next(sg);
1173 				paddr = kmap_atomic(sg_page(sg)) + sg->offset;
1174 				offset = 0;
1175 			}
1176 
1177 			sdt = paddr + offset;
1178 
1179 			pr_debug("DIF READ sector: %llu guard_tag: 0x%04x"
1180 				 " app_tag: 0x%04x ref_tag: %u\n",
1181 				 (unsigned long long)sector, sdt->guard_tag,
1182 				 sdt->app_tag, be32_to_cpu(sdt->ref_tag));
1183 
1184 			if (sdt->app_tag == cpu_to_be16(0xffff)) {
1185 				sector++;
1186 				offset += sizeof(struct se_dif_v1_tuple);
1187 				continue;
1188 			}
1189 
1190 			rc = sbc_dif_v1_verify(dev, sdt, daddr + j, sector,
1191 					       ei_lba);
1192 			if (rc) {
1193 				kunmap_atomic(paddr);
1194 				kunmap_atomic(daddr);
1195 				cmd->bad_sector = sector;
1196 				return rc;
1197 			}
1198 
1199 			sector++;
1200 			ei_lba++;
1201 			offset += sizeof(struct se_dif_v1_tuple);
1202 		}
1203 
1204 		kunmap_atomic(paddr);
1205 		kunmap_atomic(daddr);
1206 	}
1207 	sbc_dif_copy_prot(cmd, sectors, true, sg, sg_off);
1208 
1209 	return 0;
1210 }
1211 EXPORT_SYMBOL(sbc_dif_verify_read);
1212