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 = kmalloc(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 	sg_init_table(write_sg, cmd->t_data_nents);
436 	/*
437 	 * Setup verify and write data payloads from total NumberLBAs.
438 	 */
439 	rc = sg_copy_to_buffer(cmd->t_data_sg, cmd->t_data_nents, buf,
440 			       cmd->data_length);
441 	if (!rc) {
442 		pr_err("sg_copy_to_buffer() failed for compare_and_write\n");
443 		ret = TCM_OUT_OF_RESOURCES;
444 		goto out;
445 	}
446 	/*
447 	 * Compare against SCSI READ payload against verify payload
448 	 */
449 	for_each_sg(cmd->t_bidi_data_sg, sg, cmd->t_bidi_data_nents, i) {
450 		addr = (unsigned char *)kmap_atomic(sg_page(sg));
451 		if (!addr) {
452 			ret = TCM_OUT_OF_RESOURCES;
453 			goto out;
454 		}
455 
456 		len = min(sg->length, compare_len);
457 
458 		if (memcmp(addr, buf + offset, len)) {
459 			pr_warn("Detected MISCOMPARE for addr: %p buf: %p\n",
460 				addr, buf + offset);
461 			kunmap_atomic(addr);
462 			goto miscompare;
463 		}
464 		kunmap_atomic(addr);
465 
466 		offset += len;
467 		compare_len -= len;
468 		if (!compare_len)
469 			break;
470 	}
471 
472 	i = 0;
473 	len = cmd->t_task_nolb * block_size;
474 	sg_miter_start(&m, cmd->t_data_sg, cmd->t_data_nents, SG_MITER_TO_SG);
475 	/*
476 	 * Currently assumes NoLB=1 and SGLs are PAGE_SIZE..
477 	 */
478 	while (len) {
479 		sg_miter_next(&m);
480 
481 		if (block_size < PAGE_SIZE) {
482 			sg_set_page(&write_sg[i], m.page, block_size,
483 				    block_size);
484 		} else {
485 			sg_miter_next(&m);
486 			sg_set_page(&write_sg[i], m.page, block_size,
487 				    0);
488 		}
489 		len -= block_size;
490 		i++;
491 	}
492 	sg_miter_stop(&m);
493 	/*
494 	 * Save the original SGL + nents values before updating to new
495 	 * assignments, to be released in transport_free_pages() ->
496 	 * transport_reset_sgl_orig()
497 	 */
498 	cmd->t_data_sg_orig = cmd->t_data_sg;
499 	cmd->t_data_sg = write_sg;
500 	cmd->t_data_nents_orig = cmd->t_data_nents;
501 	cmd->t_data_nents = 1;
502 
503 	cmd->sam_task_attr = MSG_HEAD_TAG;
504 	cmd->transport_complete_callback = compare_and_write_post;
505 	/*
506 	 * Now reset ->execute_cmd() to the normal sbc_execute_rw() handler
507 	 * for submitting the adjusted SGL to write instance user-data.
508 	 */
509 	cmd->execute_cmd = sbc_execute_rw;
510 
511 	spin_lock_irq(&cmd->t_state_lock);
512 	cmd->t_state = TRANSPORT_PROCESSING;
513 	cmd->transport_state |= CMD_T_ACTIVE|CMD_T_BUSY|CMD_T_SENT;
514 	spin_unlock_irq(&cmd->t_state_lock);
515 
516 	__target_execute_cmd(cmd);
517 
518 	kfree(buf);
519 	return ret;
520 
521 miscompare:
522 	pr_warn("Target/%s: Send MISCOMPARE check condition and sense\n",
523 		dev->transport->name);
524 	ret = TCM_MISCOMPARE_VERIFY;
525 out:
526 	/*
527 	 * In the MISCOMPARE or failure case, unlock ->caw_sem obtained in
528 	 * sbc_compare_and_write() before the original READ I/O submission.
529 	 */
530 	up(&dev->caw_sem);
531 	kfree(write_sg);
532 	kfree(buf);
533 	return ret;
534 }
535 
536 static sense_reason_t
537 sbc_compare_and_write(struct se_cmd *cmd)
538 {
539 	struct se_device *dev = cmd->se_dev;
540 	sense_reason_t ret;
541 	int rc;
542 	/*
543 	 * Submit the READ first for COMPARE_AND_WRITE to perform the
544 	 * comparision using SGLs at cmd->t_bidi_data_sg..
545 	 */
546 	rc = down_interruptible(&dev->caw_sem);
547 	if ((rc != 0) || signal_pending(current)) {
548 		cmd->transport_complete_callback = NULL;
549 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
550 	}
551 	/*
552 	 * Reset cmd->data_length to individual block_size in order to not
553 	 * confuse backend drivers that depend on this value matching the
554 	 * size of the I/O being submitted.
555 	 */
556 	cmd->data_length = cmd->t_task_nolb * dev->dev_attrib.block_size;
557 
558 	ret = cmd->execute_rw(cmd, cmd->t_bidi_data_sg, cmd->t_bidi_data_nents,
559 			      DMA_FROM_DEVICE);
560 	if (ret) {
561 		cmd->transport_complete_callback = NULL;
562 		up(&dev->caw_sem);
563 		return ret;
564 	}
565 	/*
566 	 * Unlock of dev->caw_sem to occur in compare_and_write_callback()
567 	 * upon MISCOMPARE, or in compare_and_write_done() upon completion
568 	 * of WRITE instance user-data.
569 	 */
570 	return TCM_NO_SENSE;
571 }
572 
573 static int
574 sbc_set_prot_op_checks(u8 protect, enum target_prot_type prot_type,
575 		       bool is_write, struct se_cmd *cmd)
576 {
577 	if (is_write) {
578 		cmd->prot_op = protect ? TARGET_PROT_DOUT_PASS :
579 					 TARGET_PROT_DOUT_INSERT;
580 		switch (protect) {
581 		case 0x0:
582 		case 0x3:
583 			cmd->prot_checks = 0;
584 			break;
585 		case 0x1:
586 		case 0x5:
587 			cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
588 			if (prot_type == TARGET_DIF_TYPE1_PROT)
589 				cmd->prot_checks |= TARGET_DIF_CHECK_REFTAG;
590 			break;
591 		case 0x2:
592 			if (prot_type == TARGET_DIF_TYPE1_PROT)
593 				cmd->prot_checks = TARGET_DIF_CHECK_REFTAG;
594 			break;
595 		case 0x4:
596 			cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
597 			break;
598 		default:
599 			pr_err("Unsupported protect field %d\n", protect);
600 			return -EINVAL;
601 		}
602 	} else {
603 		cmd->prot_op = protect ? TARGET_PROT_DIN_PASS :
604 					 TARGET_PROT_DIN_STRIP;
605 		switch (protect) {
606 		case 0x0:
607 		case 0x1:
608 		case 0x5:
609 			cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
610 			if (prot_type == TARGET_DIF_TYPE1_PROT)
611 				cmd->prot_checks |= TARGET_DIF_CHECK_REFTAG;
612 			break;
613 		case 0x2:
614 			if (prot_type == TARGET_DIF_TYPE1_PROT)
615 				cmd->prot_checks = TARGET_DIF_CHECK_REFTAG;
616 			break;
617 		case 0x3:
618 			cmd->prot_checks = 0;
619 			break;
620 		case 0x4:
621 			cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
622 			break;
623 		default:
624 			pr_err("Unsupported protect field %d\n", protect);
625 			return -EINVAL;
626 		}
627 	}
628 
629 	return 0;
630 }
631 
632 static bool
633 sbc_check_prot(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb,
634 	       u32 sectors, bool is_write)
635 {
636 	u8 protect = cdb[1] >> 5;
637 
638 	if ((!cmd->t_prot_sg || !cmd->t_prot_nents) && cmd->prot_pto)
639 		return true;
640 
641 	switch (dev->dev_attrib.pi_prot_type) {
642 	case TARGET_DIF_TYPE3_PROT:
643 		cmd->reftag_seed = 0xffffffff;
644 		break;
645 	case TARGET_DIF_TYPE2_PROT:
646 		if (protect)
647 			return false;
648 
649 		cmd->reftag_seed = cmd->t_task_lba;
650 		break;
651 	case TARGET_DIF_TYPE1_PROT:
652 		cmd->reftag_seed = cmd->t_task_lba;
653 		break;
654 	case TARGET_DIF_TYPE0_PROT:
655 	default:
656 		return true;
657 	}
658 
659 	if (sbc_set_prot_op_checks(protect, dev->dev_attrib.pi_prot_type,
660 				   is_write, cmd))
661 		return false;
662 
663 	cmd->prot_type = dev->dev_attrib.pi_prot_type;
664 	cmd->prot_length = dev->prot_length * sectors;
665 	pr_debug("%s: prot_type=%d, prot_length=%d prot_op=%d prot_checks=%d\n",
666 		 __func__, cmd->prot_type, cmd->prot_length,
667 		 cmd->prot_op, cmd->prot_checks);
668 
669 	return true;
670 }
671 
672 sense_reason_t
673 sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
674 {
675 	struct se_device *dev = cmd->se_dev;
676 	unsigned char *cdb = cmd->t_task_cdb;
677 	unsigned int size;
678 	u32 sectors = 0;
679 	sense_reason_t ret;
680 
681 	switch (cdb[0]) {
682 	case READ_6:
683 		sectors = transport_get_sectors_6(cdb);
684 		cmd->t_task_lba = transport_lba_21(cdb);
685 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
686 		cmd->execute_rw = ops->execute_rw;
687 		cmd->execute_cmd = sbc_execute_rw;
688 		break;
689 	case READ_10:
690 		sectors = transport_get_sectors_10(cdb);
691 		cmd->t_task_lba = transport_lba_32(cdb);
692 
693 		if (!sbc_check_prot(dev, cmd, cdb, sectors, false))
694 			return TCM_UNSUPPORTED_SCSI_OPCODE;
695 
696 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
697 		cmd->execute_rw = ops->execute_rw;
698 		cmd->execute_cmd = sbc_execute_rw;
699 		break;
700 	case READ_12:
701 		sectors = transport_get_sectors_12(cdb);
702 		cmd->t_task_lba = transport_lba_32(cdb);
703 
704 		if (!sbc_check_prot(dev, cmd, cdb, sectors, false))
705 			return TCM_UNSUPPORTED_SCSI_OPCODE;
706 
707 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
708 		cmd->execute_rw = ops->execute_rw;
709 		cmd->execute_cmd = sbc_execute_rw;
710 		break;
711 	case READ_16:
712 		sectors = transport_get_sectors_16(cdb);
713 		cmd->t_task_lba = transport_lba_64(cdb);
714 
715 		if (!sbc_check_prot(dev, cmd, cdb, sectors, false))
716 			return TCM_UNSUPPORTED_SCSI_OPCODE;
717 
718 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
719 		cmd->execute_rw = ops->execute_rw;
720 		cmd->execute_cmd = sbc_execute_rw;
721 		break;
722 	case WRITE_6:
723 		sectors = transport_get_sectors_6(cdb);
724 		cmd->t_task_lba = transport_lba_21(cdb);
725 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
726 		cmd->execute_rw = ops->execute_rw;
727 		cmd->execute_cmd = sbc_execute_rw;
728 		break;
729 	case WRITE_10:
730 	case WRITE_VERIFY:
731 		sectors = transport_get_sectors_10(cdb);
732 		cmd->t_task_lba = transport_lba_32(cdb);
733 
734 		if (!sbc_check_prot(dev, cmd, cdb, sectors, true))
735 			return TCM_UNSUPPORTED_SCSI_OPCODE;
736 
737 		if (cdb[1] & 0x8)
738 			cmd->se_cmd_flags |= SCF_FUA;
739 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
740 		cmd->execute_rw = ops->execute_rw;
741 		cmd->execute_cmd = sbc_execute_rw;
742 		break;
743 	case WRITE_12:
744 		sectors = transport_get_sectors_12(cdb);
745 		cmd->t_task_lba = transport_lba_32(cdb);
746 
747 		if (!sbc_check_prot(dev, cmd, cdb, sectors, true))
748 			return TCM_UNSUPPORTED_SCSI_OPCODE;
749 
750 		if (cdb[1] & 0x8)
751 			cmd->se_cmd_flags |= SCF_FUA;
752 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
753 		cmd->execute_rw = ops->execute_rw;
754 		cmd->execute_cmd = sbc_execute_rw;
755 		break;
756 	case WRITE_16:
757 		sectors = transport_get_sectors_16(cdb);
758 		cmd->t_task_lba = transport_lba_64(cdb);
759 
760 		if (!sbc_check_prot(dev, cmd, cdb, sectors, true))
761 			return TCM_UNSUPPORTED_SCSI_OPCODE;
762 
763 		if (cdb[1] & 0x8)
764 			cmd->se_cmd_flags |= SCF_FUA;
765 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
766 		cmd->execute_rw = ops->execute_rw;
767 		cmd->execute_cmd = sbc_execute_rw;
768 		break;
769 	case XDWRITEREAD_10:
770 		if (cmd->data_direction != DMA_TO_DEVICE ||
771 		    !(cmd->se_cmd_flags & SCF_BIDI))
772 			return TCM_INVALID_CDB_FIELD;
773 		sectors = transport_get_sectors_10(cdb);
774 
775 		cmd->t_task_lba = transport_lba_32(cdb);
776 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
777 
778 		/*
779 		 * Setup BIDI XOR callback to be run after I/O completion.
780 		 */
781 		cmd->execute_rw = ops->execute_rw;
782 		cmd->execute_cmd = sbc_execute_rw;
783 		cmd->transport_complete_callback = &xdreadwrite_callback;
784 		if (cdb[1] & 0x8)
785 			cmd->se_cmd_flags |= SCF_FUA;
786 		break;
787 	case VARIABLE_LENGTH_CMD:
788 	{
789 		u16 service_action = get_unaligned_be16(&cdb[8]);
790 		switch (service_action) {
791 		case XDWRITEREAD_32:
792 			sectors = transport_get_sectors_32(cdb);
793 
794 			/*
795 			 * Use WRITE_32 and READ_32 opcodes for the emulated
796 			 * XDWRITE_READ_32 logic.
797 			 */
798 			cmd->t_task_lba = transport_lba_64_ext(cdb);
799 			cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
800 
801 			/*
802 			 * Setup BIDI XOR callback to be run during after I/O
803 			 * completion.
804 			 */
805 			cmd->execute_rw = ops->execute_rw;
806 			cmd->execute_cmd = sbc_execute_rw;
807 			cmd->transport_complete_callback = &xdreadwrite_callback;
808 			if (cdb[1] & 0x8)
809 				cmd->se_cmd_flags |= SCF_FUA;
810 			break;
811 		case WRITE_SAME_32:
812 			sectors = transport_get_sectors_32(cdb);
813 			if (!sectors) {
814 				pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not"
815 				       " supported\n");
816 				return TCM_INVALID_CDB_FIELD;
817 			}
818 
819 			size = sbc_get_size(cmd, 1);
820 			cmd->t_task_lba = get_unaligned_be64(&cdb[12]);
821 
822 			ret = sbc_setup_write_same(cmd, &cdb[10], ops);
823 			if (ret)
824 				return ret;
825 			break;
826 		default:
827 			pr_err("VARIABLE_LENGTH_CMD service action"
828 				" 0x%04x not supported\n", service_action);
829 			return TCM_UNSUPPORTED_SCSI_OPCODE;
830 		}
831 		break;
832 	}
833 	case COMPARE_AND_WRITE:
834 		sectors = cdb[13];
835 		/*
836 		 * Currently enforce COMPARE_AND_WRITE for a single sector
837 		 */
838 		if (sectors > 1) {
839 			pr_err("COMPARE_AND_WRITE contains NoLB: %u greater"
840 			       " than 1\n", sectors);
841 			return TCM_INVALID_CDB_FIELD;
842 		}
843 		/*
844 		 * Double size because we have two buffers, note that
845 		 * zero is not an error..
846 		 */
847 		size = 2 * sbc_get_size(cmd, sectors);
848 		cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
849 		cmd->t_task_nolb = sectors;
850 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB | SCF_COMPARE_AND_WRITE;
851 		cmd->execute_rw = ops->execute_rw;
852 		cmd->execute_cmd = sbc_compare_and_write;
853 		cmd->transport_complete_callback = compare_and_write_callback;
854 		break;
855 	case READ_CAPACITY:
856 		size = READ_CAP_LEN;
857 		cmd->execute_cmd = sbc_emulate_readcapacity;
858 		break;
859 	case SERVICE_ACTION_IN:
860 		switch (cmd->t_task_cdb[1] & 0x1f) {
861 		case SAI_READ_CAPACITY_16:
862 			cmd->execute_cmd = sbc_emulate_readcapacity_16;
863 			break;
864 		case SAI_REPORT_REFERRALS:
865 			cmd->execute_cmd = target_emulate_report_referrals;
866 			break;
867 		default:
868 			pr_err("Unsupported SA: 0x%02x\n",
869 				cmd->t_task_cdb[1] & 0x1f);
870 			return TCM_INVALID_CDB_FIELD;
871 		}
872 		size = (cdb[10] << 24) | (cdb[11] << 16) |
873 		       (cdb[12] << 8) | cdb[13];
874 		break;
875 	case SYNCHRONIZE_CACHE:
876 	case SYNCHRONIZE_CACHE_16:
877 		if (!ops->execute_sync_cache) {
878 			size = 0;
879 			cmd->execute_cmd = sbc_emulate_noop;
880 			break;
881 		}
882 
883 		/*
884 		 * Extract LBA and range to be flushed for emulated SYNCHRONIZE_CACHE
885 		 */
886 		if (cdb[0] == SYNCHRONIZE_CACHE) {
887 			sectors = transport_get_sectors_10(cdb);
888 			cmd->t_task_lba = transport_lba_32(cdb);
889 		} else {
890 			sectors = transport_get_sectors_16(cdb);
891 			cmd->t_task_lba = transport_lba_64(cdb);
892 		}
893 
894 		size = sbc_get_size(cmd, sectors);
895 
896 		/*
897 		 * Check to ensure that LBA + Range does not exceed past end of
898 		 * device for IBLOCK and FILEIO ->do_sync_cache() backend calls
899 		 */
900 		if (cmd->t_task_lba || sectors) {
901 			if (sbc_check_valid_sectors(cmd) < 0)
902 				return TCM_ADDRESS_OUT_OF_RANGE;
903 		}
904 		cmd->execute_cmd = ops->execute_sync_cache;
905 		break;
906 	case UNMAP:
907 		if (!ops->execute_unmap)
908 			return TCM_UNSUPPORTED_SCSI_OPCODE;
909 
910 		size = get_unaligned_be16(&cdb[7]);
911 		cmd->execute_cmd = ops->execute_unmap;
912 		break;
913 	case WRITE_SAME_16:
914 		sectors = transport_get_sectors_16(cdb);
915 		if (!sectors) {
916 			pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
917 			return TCM_INVALID_CDB_FIELD;
918 		}
919 
920 		size = sbc_get_size(cmd, 1);
921 		cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
922 
923 		ret = sbc_setup_write_same(cmd, &cdb[1], ops);
924 		if (ret)
925 			return ret;
926 		break;
927 	case WRITE_SAME:
928 		sectors = transport_get_sectors_10(cdb);
929 		if (!sectors) {
930 			pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
931 			return TCM_INVALID_CDB_FIELD;
932 		}
933 
934 		size = sbc_get_size(cmd, 1);
935 		cmd->t_task_lba = get_unaligned_be32(&cdb[2]);
936 
937 		/*
938 		 * Follow sbcr26 with WRITE_SAME (10) and check for the existence
939 		 * of byte 1 bit 3 UNMAP instead of original reserved field
940 		 */
941 		ret = sbc_setup_write_same(cmd, &cdb[1], ops);
942 		if (ret)
943 			return ret;
944 		break;
945 	case VERIFY:
946 		size = 0;
947 		cmd->execute_cmd = sbc_emulate_noop;
948 		break;
949 	case REZERO_UNIT:
950 	case SEEK_6:
951 	case SEEK_10:
952 		/*
953 		 * There are still clients out there which use these old SCSI-2
954 		 * commands. This mainly happens when running VMs with legacy
955 		 * guest systems, connected via SCSI command pass-through to
956 		 * iSCSI targets. Make them happy and return status GOOD.
957 		 */
958 		size = 0;
959 		cmd->execute_cmd = sbc_emulate_noop;
960 		break;
961 	default:
962 		ret = spc_parse_cdb(cmd, &size);
963 		if (ret)
964 			return ret;
965 	}
966 
967 	/* reject any command that we don't have a handler for */
968 	if (!(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) && !cmd->execute_cmd)
969 		return TCM_UNSUPPORTED_SCSI_OPCODE;
970 
971 	if (cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
972 		unsigned long long end_lba;
973 
974 		if (sectors > dev->dev_attrib.fabric_max_sectors) {
975 			printk_ratelimited(KERN_ERR "SCSI OP %02xh with too"
976 				" big sectors %u exceeds fabric_max_sectors:"
977 				" %u\n", cdb[0], sectors,
978 				dev->dev_attrib.fabric_max_sectors);
979 			return TCM_INVALID_CDB_FIELD;
980 		}
981 		if (sectors > dev->dev_attrib.hw_max_sectors) {
982 			printk_ratelimited(KERN_ERR "SCSI OP %02xh with too"
983 				" big sectors %u exceeds backend hw_max_sectors:"
984 				" %u\n", cdb[0], sectors,
985 				dev->dev_attrib.hw_max_sectors);
986 			return TCM_INVALID_CDB_FIELD;
987 		}
988 
989 		end_lba = dev->transport->get_blocks(dev) + 1;
990 		if (cmd->t_task_lba + sectors > end_lba) {
991 			pr_err("cmd exceeds last lba %llu "
992 				"(lba %llu, sectors %u)\n",
993 				end_lba, cmd->t_task_lba, sectors);
994 			return TCM_ADDRESS_OUT_OF_RANGE;
995 		}
996 
997 		if (!(cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE))
998 			size = sbc_get_size(cmd, sectors);
999 	}
1000 
1001 	return target_cmd_size_check(cmd, size);
1002 }
1003 EXPORT_SYMBOL(sbc_parse_cdb);
1004 
1005 u32 sbc_get_device_type(struct se_device *dev)
1006 {
1007 	return TYPE_DISK;
1008 }
1009 EXPORT_SYMBOL(sbc_get_device_type);
1010 
1011 sense_reason_t
1012 sbc_execute_unmap(struct se_cmd *cmd,
1013 	sense_reason_t (*do_unmap_fn)(struct se_cmd *, void *,
1014 				      sector_t, sector_t),
1015 	void *priv)
1016 {
1017 	struct se_device *dev = cmd->se_dev;
1018 	unsigned char *buf, *ptr = NULL;
1019 	sector_t lba;
1020 	int size;
1021 	u32 range;
1022 	sense_reason_t ret = 0;
1023 	int dl, bd_dl;
1024 
1025 	/* We never set ANC_SUP */
1026 	if (cmd->t_task_cdb[1])
1027 		return TCM_INVALID_CDB_FIELD;
1028 
1029 	if (cmd->data_length == 0) {
1030 		target_complete_cmd(cmd, SAM_STAT_GOOD);
1031 		return 0;
1032 	}
1033 
1034 	if (cmd->data_length < 8) {
1035 		pr_warn("UNMAP parameter list length %u too small\n",
1036 			cmd->data_length);
1037 		return TCM_PARAMETER_LIST_LENGTH_ERROR;
1038 	}
1039 
1040 	buf = transport_kmap_data_sg(cmd);
1041 	if (!buf)
1042 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1043 
1044 	dl = get_unaligned_be16(&buf[0]);
1045 	bd_dl = get_unaligned_be16(&buf[2]);
1046 
1047 	size = cmd->data_length - 8;
1048 	if (bd_dl > size)
1049 		pr_warn("UNMAP parameter list length %u too small, ignoring bd_dl %u\n",
1050 			cmd->data_length, bd_dl);
1051 	else
1052 		size = bd_dl;
1053 
1054 	if (size / 16 > dev->dev_attrib.max_unmap_block_desc_count) {
1055 		ret = TCM_INVALID_PARAMETER_LIST;
1056 		goto err;
1057 	}
1058 
1059 	/* First UNMAP block descriptor starts at 8 byte offset */
1060 	ptr = &buf[8];
1061 	pr_debug("UNMAP: Sub: %s Using dl: %u bd_dl: %u size: %u"
1062 		" ptr: %p\n", dev->transport->name, dl, bd_dl, size, ptr);
1063 
1064 	while (size >= 16) {
1065 		lba = get_unaligned_be64(&ptr[0]);
1066 		range = get_unaligned_be32(&ptr[8]);
1067 		pr_debug("UNMAP: Using lba: %llu and range: %u\n",
1068 				 (unsigned long long)lba, range);
1069 
1070 		if (range > dev->dev_attrib.max_unmap_lba_count) {
1071 			ret = TCM_INVALID_PARAMETER_LIST;
1072 			goto err;
1073 		}
1074 
1075 		if (lba + range > dev->transport->get_blocks(dev) + 1) {
1076 			ret = TCM_ADDRESS_OUT_OF_RANGE;
1077 			goto err;
1078 		}
1079 
1080 		ret = do_unmap_fn(cmd, priv, lba, range);
1081 		if (ret)
1082 			goto err;
1083 
1084 		ptr += 16;
1085 		size -= 16;
1086 	}
1087 
1088 err:
1089 	transport_kunmap_data_sg(cmd);
1090 	if (!ret)
1091 		target_complete_cmd(cmd, GOOD);
1092 	return ret;
1093 }
1094 EXPORT_SYMBOL(sbc_execute_unmap);
1095 
1096 static sense_reason_t
1097 sbc_dif_v1_verify(struct se_device *dev, struct se_dif_v1_tuple *sdt,
1098 		  const void *p, sector_t sector, unsigned int ei_lba)
1099 {
1100 	int block_size = dev->dev_attrib.block_size;
1101 	__be16 csum;
1102 
1103 	csum = cpu_to_be16(crc_t10dif(p, block_size));
1104 
1105 	if (sdt->guard_tag != csum) {
1106 		pr_err("DIFv1 checksum failed on sector %llu guard tag 0x%04x"
1107 			" csum 0x%04x\n", (unsigned long long)sector,
1108 			be16_to_cpu(sdt->guard_tag), be16_to_cpu(csum));
1109 		return TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED;
1110 	}
1111 
1112 	if (dev->dev_attrib.pi_prot_type == TARGET_DIF_TYPE1_PROT &&
1113 	    be32_to_cpu(sdt->ref_tag) != (sector & 0xffffffff)) {
1114 		pr_err("DIFv1 Type 1 reference failed on sector: %llu tag: 0x%08x"
1115 		       " sector MSB: 0x%08x\n", (unsigned long long)sector,
1116 		       be32_to_cpu(sdt->ref_tag), (u32)(sector & 0xffffffff));
1117 		return TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;
1118 	}
1119 
1120 	if (dev->dev_attrib.pi_prot_type == TARGET_DIF_TYPE2_PROT &&
1121 	    be32_to_cpu(sdt->ref_tag) != ei_lba) {
1122 		pr_err("DIFv1 Type 2 reference failed on sector: %llu tag: 0x%08x"
1123 		       " ei_lba: 0x%08x\n", (unsigned long long)sector,
1124 			be32_to_cpu(sdt->ref_tag), ei_lba);
1125 		return TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;
1126 	}
1127 
1128 	return 0;
1129 }
1130 
1131 static void
1132 sbc_dif_copy_prot(struct se_cmd *cmd, unsigned int sectors, bool read,
1133 		  struct scatterlist *sg, int sg_off)
1134 {
1135 	struct se_device *dev = cmd->se_dev;
1136 	struct scatterlist *psg;
1137 	void *paddr, *addr;
1138 	unsigned int i, len, left;
1139 	unsigned int offset = sg_off;
1140 
1141 	left = sectors * dev->prot_length;
1142 
1143 	for_each_sg(cmd->t_prot_sg, psg, cmd->t_prot_nents, i) {
1144 		unsigned int psg_len, copied = 0;
1145 
1146 		paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1147 		psg_len = min(left, psg->length);
1148 		while (psg_len) {
1149 			len = min(psg_len, sg->length - offset);
1150 			addr = kmap_atomic(sg_page(sg)) + sg->offset + offset;
1151 
1152 			if (read)
1153 				memcpy(paddr + copied, addr, len);
1154 			else
1155 				memcpy(addr, paddr + copied, len);
1156 
1157 			left -= len;
1158 			offset += len;
1159 			copied += len;
1160 			psg_len -= len;
1161 
1162 			if (offset >= sg->length) {
1163 				sg = sg_next(sg);
1164 				offset = 0;
1165 			}
1166 			kunmap_atomic(addr);
1167 		}
1168 		kunmap_atomic(paddr);
1169 	}
1170 }
1171 
1172 sense_reason_t
1173 sbc_dif_verify_write(struct se_cmd *cmd, sector_t start, unsigned int sectors,
1174 		     unsigned int ei_lba, struct scatterlist *sg, int sg_off)
1175 {
1176 	struct se_device *dev = cmd->se_dev;
1177 	struct se_dif_v1_tuple *sdt;
1178 	struct scatterlist *dsg, *psg = cmd->t_prot_sg;
1179 	sector_t sector = start;
1180 	void *daddr, *paddr;
1181 	int i, j, offset = 0;
1182 	sense_reason_t rc;
1183 
1184 	for_each_sg(cmd->t_data_sg, dsg, cmd->t_data_nents, i) {
1185 		daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1186 		paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1187 
1188 		for (j = 0; j < dsg->length; j += dev->dev_attrib.block_size) {
1189 
1190 			if (offset >= psg->length) {
1191 				kunmap_atomic(paddr);
1192 				psg = sg_next(psg);
1193 				paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1194 				offset = 0;
1195 			}
1196 
1197 			sdt = paddr + offset;
1198 
1199 			pr_debug("DIF WRITE sector: %llu guard_tag: 0x%04x"
1200 				 " app_tag: 0x%04x ref_tag: %u\n",
1201 				 (unsigned long long)sector, sdt->guard_tag,
1202 				 sdt->app_tag, be32_to_cpu(sdt->ref_tag));
1203 
1204 			rc = sbc_dif_v1_verify(dev, sdt, daddr + j, sector,
1205 					       ei_lba);
1206 			if (rc) {
1207 				kunmap_atomic(paddr);
1208 				kunmap_atomic(daddr);
1209 				cmd->bad_sector = sector;
1210 				return rc;
1211 			}
1212 
1213 			sector++;
1214 			ei_lba++;
1215 			offset += sizeof(struct se_dif_v1_tuple);
1216 		}
1217 
1218 		kunmap_atomic(paddr);
1219 		kunmap_atomic(daddr);
1220 	}
1221 	sbc_dif_copy_prot(cmd, sectors, false, sg, sg_off);
1222 
1223 	return 0;
1224 }
1225 EXPORT_SYMBOL(sbc_dif_verify_write);
1226 
1227 sense_reason_t
1228 sbc_dif_verify_read(struct se_cmd *cmd, sector_t start, unsigned int sectors,
1229 		    unsigned int ei_lba, struct scatterlist *sg, int sg_off)
1230 {
1231 	struct se_device *dev = cmd->se_dev;
1232 	struct se_dif_v1_tuple *sdt;
1233 	struct scatterlist *dsg, *psg = sg;
1234 	sector_t sector = start;
1235 	void *daddr, *paddr;
1236 	int i, j, offset = sg_off;
1237 	sense_reason_t rc;
1238 
1239 	for_each_sg(cmd->t_data_sg, dsg, cmd->t_data_nents, i) {
1240 		daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1241 		paddr = kmap_atomic(sg_page(psg)) + sg->offset;
1242 
1243 		for (j = 0; j < dsg->length; j += dev->dev_attrib.block_size) {
1244 
1245 			if (offset >= psg->length) {
1246 				kunmap_atomic(paddr);
1247 				psg = sg_next(psg);
1248 				paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1249 				offset = 0;
1250 			}
1251 
1252 			sdt = paddr + offset;
1253 
1254 			pr_debug("DIF READ sector: %llu guard_tag: 0x%04x"
1255 				 " app_tag: 0x%04x ref_tag: %u\n",
1256 				 (unsigned long long)sector, sdt->guard_tag,
1257 				 sdt->app_tag, be32_to_cpu(sdt->ref_tag));
1258 
1259 			if (sdt->app_tag == cpu_to_be16(0xffff)) {
1260 				sector++;
1261 				offset += sizeof(struct se_dif_v1_tuple);
1262 				continue;
1263 			}
1264 
1265 			rc = sbc_dif_v1_verify(dev, sdt, daddr + j, sector,
1266 					       ei_lba);
1267 			if (rc) {
1268 				kunmap_atomic(paddr);
1269 				kunmap_atomic(daddr);
1270 				cmd->bad_sector = sector;
1271 				return rc;
1272 			}
1273 
1274 			sector++;
1275 			ei_lba++;
1276 			offset += sizeof(struct se_dif_v1_tuple);
1277 		}
1278 
1279 		kunmap_atomic(paddr);
1280 		kunmap_atomic(daddr);
1281 	}
1282 	sbc_dif_copy_prot(cmd, sectors, true, sg, sg_off);
1283 
1284 	return 0;
1285 }
1286 EXPORT_SYMBOL(sbc_dif_verify_read);
1287