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 <linux/t10-pi.h>
28 #include <asm/unaligned.h>
29 #include <scsi/scsi_proto.h>
30 #include <scsi/scsi_tcq.h>
31 
32 #include <target/target_core_base.h>
33 #include <target/target_core_backend.h>
34 #include <target/target_core_fabric.h>
35 
36 #include "target_core_internal.h"
37 #include "target_core_ua.h"
38 #include "target_core_alua.h"
39 
40 static sense_reason_t
41 sbc_check_prot(struct se_device *, struct se_cmd *, unsigned char *, u32, bool);
42 static sense_reason_t sbc_execute_unmap(struct se_cmd *cmd);
43 
44 static sense_reason_t
45 sbc_emulate_readcapacity(struct se_cmd *cmd)
46 {
47 	struct se_device *dev = cmd->se_dev;
48 	unsigned char *cdb = cmd->t_task_cdb;
49 	unsigned long long blocks_long = dev->transport->get_blocks(dev);
50 	unsigned char *rbuf;
51 	unsigned char buf[8];
52 	u32 blocks;
53 
54 	/*
55 	 * SBC-2 says:
56 	 *   If the PMI bit is set to zero and the LOGICAL BLOCK
57 	 *   ADDRESS field is not set to zero, the device server shall
58 	 *   terminate the command with CHECK CONDITION status with
59 	 *   the sense key set to ILLEGAL REQUEST and the additional
60 	 *   sense code set to INVALID FIELD IN CDB.
61 	 *
62 	 * In SBC-3, these fields are obsolete, but some SCSI
63 	 * compliance tests actually check this, so we might as well
64 	 * follow SBC-2.
65 	 */
66 	if (!(cdb[8] & 1) && !!(cdb[2] | cdb[3] | cdb[4] | cdb[5]))
67 		return TCM_INVALID_CDB_FIELD;
68 
69 	if (blocks_long >= 0x00000000ffffffff)
70 		blocks = 0xffffffff;
71 	else
72 		blocks = (u32)blocks_long;
73 
74 	put_unaligned_be32(blocks, &buf[0]);
75 	put_unaligned_be32(dev->dev_attrib.block_size, &buf[4]);
76 
77 	rbuf = transport_kmap_data_sg(cmd);
78 	if (rbuf) {
79 		memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length));
80 		transport_kunmap_data_sg(cmd);
81 	}
82 
83 	target_complete_cmd_with_length(cmd, GOOD, 8);
84 	return 0;
85 }
86 
87 static sense_reason_t
88 sbc_emulate_readcapacity_16(struct se_cmd *cmd)
89 {
90 	struct se_device *dev = cmd->se_dev;
91 	struct se_session *sess = cmd->se_sess;
92 	int pi_prot_type = dev->dev_attrib.pi_prot_type;
93 
94 	unsigned char *rbuf;
95 	unsigned char buf[32];
96 	unsigned long long blocks = dev->transport->get_blocks(dev);
97 
98 	memset(buf, 0, sizeof(buf));
99 	put_unaligned_be64(blocks, &buf[0]);
100 	put_unaligned_be32(dev->dev_attrib.block_size, &buf[8]);
101 	/*
102 	 * Set P_TYPE and PROT_EN bits for DIF support
103 	 */
104 	if (sess->sup_prot_ops & (TARGET_PROT_DIN_PASS | TARGET_PROT_DOUT_PASS)) {
105 		/*
106 		 * Only override a device's pi_prot_type if no T10-PI is
107 		 * available, and sess_prot_type has been explicitly enabled.
108 		 */
109 		if (!pi_prot_type)
110 			pi_prot_type = sess->sess_prot_type;
111 
112 		if (pi_prot_type)
113 			buf[12] = (pi_prot_type - 1) << 1 | 0x1;
114 	}
115 
116 	if (dev->transport->get_lbppbe)
117 		buf[13] = dev->transport->get_lbppbe(dev) & 0x0f;
118 
119 	if (dev->transport->get_alignment_offset_lbas) {
120 		u16 lalba = dev->transport->get_alignment_offset_lbas(dev);
121 
122 		put_unaligned_be16(lalba, &buf[14]);
123 	}
124 
125 	/*
126 	 * Set Thin Provisioning Enable bit following sbc3r22 in section
127 	 * READ CAPACITY (16) byte 14 if emulate_tpu or emulate_tpws is enabled.
128 	 */
129 	if (dev->dev_attrib.emulate_tpu || dev->dev_attrib.emulate_tpws) {
130 		buf[14] |= 0x80;
131 
132 		/*
133 		 * LBPRZ signifies that zeroes will be read back from an LBA after
134 		 * an UNMAP or WRITE SAME w/ unmap bit (sbc3r36 5.16.2)
135 		 */
136 		if (dev->dev_attrib.unmap_zeroes_data)
137 			buf[14] |= 0x40;
138 	}
139 
140 	rbuf = transport_kmap_data_sg(cmd);
141 	if (rbuf) {
142 		memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length));
143 		transport_kunmap_data_sg(cmd);
144 	}
145 
146 	target_complete_cmd_with_length(cmd, GOOD, 32);
147 	return 0;
148 }
149 
150 static sense_reason_t
151 sbc_emulate_startstop(struct se_cmd *cmd)
152 {
153 	unsigned char *cdb = cmd->t_task_cdb;
154 
155 	/*
156 	 * See sbc3r36 section 5.25
157 	 * Immediate bit should be set since there is nothing to complete
158 	 * POWER CONDITION MODIFIER 0h
159 	 */
160 	if (!(cdb[1] & 1) || cdb[2] || cdb[3])
161 		return TCM_INVALID_CDB_FIELD;
162 
163 	/*
164 	 * See sbc3r36 section 5.25
165 	 * POWER CONDITION 0h START_VALID - process START and LOEJ
166 	 */
167 	if (cdb[4] >> 4 & 0xf)
168 		return TCM_INVALID_CDB_FIELD;
169 
170 	/*
171 	 * See sbc3r36 section 5.25
172 	 * LOEJ 0h - nothing to load or unload
173 	 * START 1h - we are ready
174 	 */
175 	if (!(cdb[4] & 1) || (cdb[4] & 2) || (cdb[4] & 4))
176 		return TCM_INVALID_CDB_FIELD;
177 
178 	target_complete_cmd(cmd, SAM_STAT_GOOD);
179 	return 0;
180 }
181 
182 sector_t sbc_get_write_same_sectors(struct se_cmd *cmd)
183 {
184 	u32 num_blocks;
185 
186 	if (cmd->t_task_cdb[0] == WRITE_SAME)
187 		num_blocks = get_unaligned_be16(&cmd->t_task_cdb[7]);
188 	else if (cmd->t_task_cdb[0] == WRITE_SAME_16)
189 		num_blocks = get_unaligned_be32(&cmd->t_task_cdb[10]);
190 	else /* WRITE_SAME_32 via VARIABLE_LENGTH_CMD */
191 		num_blocks = get_unaligned_be32(&cmd->t_task_cdb[28]);
192 
193 	/*
194 	 * Use the explicit range when non zero is supplied, otherwise calculate
195 	 * the remaining range based on ->get_blocks() - starting LBA.
196 	 */
197 	if (num_blocks)
198 		return num_blocks;
199 
200 	return cmd->se_dev->transport->get_blocks(cmd->se_dev) -
201 		cmd->t_task_lba + 1;
202 }
203 EXPORT_SYMBOL(sbc_get_write_same_sectors);
204 
205 static sense_reason_t
206 sbc_execute_write_same_unmap(struct se_cmd *cmd)
207 {
208 	struct sbc_ops *ops = cmd->protocol_data;
209 	sector_t nolb = sbc_get_write_same_sectors(cmd);
210 	sense_reason_t ret;
211 
212 	if (nolb) {
213 		ret = ops->execute_unmap(cmd, cmd->t_task_lba, nolb);
214 		if (ret)
215 			return ret;
216 	}
217 
218 	target_complete_cmd(cmd, GOOD);
219 	return 0;
220 }
221 
222 static sense_reason_t
223 sbc_emulate_noop(struct se_cmd *cmd)
224 {
225 	target_complete_cmd(cmd, GOOD);
226 	return 0;
227 }
228 
229 static inline u32 sbc_get_size(struct se_cmd *cmd, u32 sectors)
230 {
231 	return cmd->se_dev->dev_attrib.block_size * sectors;
232 }
233 
234 static inline u32 transport_get_sectors_6(unsigned char *cdb)
235 {
236 	/*
237 	 * Use 8-bit sector value.  SBC-3 says:
238 	 *
239 	 *   A TRANSFER LENGTH field set to zero specifies that 256
240 	 *   logical blocks shall be written.  Any other value
241 	 *   specifies the number of logical blocks that shall be
242 	 *   written.
243 	 */
244 	return cdb[4] ? : 256;
245 }
246 
247 static inline u32 transport_get_sectors_10(unsigned char *cdb)
248 {
249 	return get_unaligned_be16(&cdb[7]);
250 }
251 
252 static inline u32 transport_get_sectors_12(unsigned char *cdb)
253 {
254 	return get_unaligned_be32(&cdb[6]);
255 }
256 
257 static inline u32 transport_get_sectors_16(unsigned char *cdb)
258 {
259 	return get_unaligned_be32(&cdb[10]);
260 }
261 
262 /*
263  * Used for VARIABLE_LENGTH_CDB WRITE_32 and READ_32 variants
264  */
265 static inline u32 transport_get_sectors_32(unsigned char *cdb)
266 {
267 	return get_unaligned_be32(&cdb[28]);
268 
269 }
270 
271 static inline u32 transport_lba_21(unsigned char *cdb)
272 {
273 	return get_unaligned_be24(&cdb[1]) & 0x1fffff;
274 }
275 
276 static inline u32 transport_lba_32(unsigned char *cdb)
277 {
278 	return get_unaligned_be32(&cdb[2]);
279 }
280 
281 static inline unsigned long long transport_lba_64(unsigned char *cdb)
282 {
283 	return get_unaligned_be64(&cdb[2]);
284 }
285 
286 /*
287  * For VARIABLE_LENGTH_CDB w/ 32 byte extended CDBs
288  */
289 static inline unsigned long long transport_lba_64_ext(unsigned char *cdb)
290 {
291 	return get_unaligned_be64(&cdb[12]);
292 }
293 
294 static sense_reason_t
295 sbc_setup_write_same(struct se_cmd *cmd, unsigned char *flags, struct sbc_ops *ops)
296 {
297 	struct se_device *dev = cmd->se_dev;
298 	sector_t end_lba = dev->transport->get_blocks(dev) + 1;
299 	unsigned int sectors = sbc_get_write_same_sectors(cmd);
300 	sense_reason_t ret;
301 
302 	if ((flags[0] & 0x04) || (flags[0] & 0x02)) {
303 		pr_err("WRITE_SAME PBDATA and LBDATA"
304 			" bits not supported for Block Discard"
305 			" Emulation\n");
306 		return TCM_UNSUPPORTED_SCSI_OPCODE;
307 	}
308 	if (sectors > cmd->se_dev->dev_attrib.max_write_same_len) {
309 		pr_warn("WRITE_SAME sectors: %u exceeds max_write_same_len: %u\n",
310 			sectors, cmd->se_dev->dev_attrib.max_write_same_len);
311 		return TCM_INVALID_CDB_FIELD;
312 	}
313 	/*
314 	 * Sanity check for LBA wrap and request past end of device.
315 	 */
316 	if (((cmd->t_task_lba + sectors) < cmd->t_task_lba) ||
317 	    ((cmd->t_task_lba + sectors) > end_lba)) {
318 		pr_err("WRITE_SAME exceeds last lba %llu (lba %llu, sectors %u)\n",
319 		       (unsigned long long)end_lba, cmd->t_task_lba, sectors);
320 		return TCM_ADDRESS_OUT_OF_RANGE;
321 	}
322 
323 	/* We always have ANC_SUP == 0 so setting ANCHOR is always an error */
324 	if (flags[0] & 0x10) {
325 		pr_warn("WRITE SAME with ANCHOR not supported\n");
326 		return TCM_INVALID_CDB_FIELD;
327 	}
328 	/*
329 	 * Special case for WRITE_SAME w/ UNMAP=1 that ends up getting
330 	 * translated into block discard requests within backend code.
331 	 */
332 	if (flags[0] & 0x08) {
333 		if (!ops->execute_unmap)
334 			return TCM_UNSUPPORTED_SCSI_OPCODE;
335 
336 		if (!dev->dev_attrib.emulate_tpws) {
337 			pr_err("Got WRITE_SAME w/ UNMAP=1, but backend device"
338 			       " has emulate_tpws disabled\n");
339 			return TCM_UNSUPPORTED_SCSI_OPCODE;
340 		}
341 		cmd->execute_cmd = sbc_execute_write_same_unmap;
342 		return 0;
343 	}
344 	if (!ops->execute_write_same)
345 		return TCM_UNSUPPORTED_SCSI_OPCODE;
346 
347 	ret = sbc_check_prot(dev, cmd, &cmd->t_task_cdb[0], sectors, true);
348 	if (ret)
349 		return ret;
350 
351 	cmd->execute_cmd = ops->execute_write_same;
352 	return 0;
353 }
354 
355 static sense_reason_t xdreadwrite_callback(struct se_cmd *cmd, bool success,
356 					   int *post_ret)
357 {
358 	unsigned char *buf, *addr;
359 	struct scatterlist *sg;
360 	unsigned int offset;
361 	sense_reason_t ret = TCM_NO_SENSE;
362 	int i, count;
363 	/*
364 	 * From sbc3r22.pdf section 5.48 XDWRITEREAD (10) command
365 	 *
366 	 * 1) read the specified logical block(s);
367 	 * 2) transfer logical blocks from the data-out buffer;
368 	 * 3) XOR the logical blocks transferred from the data-out buffer with
369 	 *    the logical blocks read, storing the resulting XOR data in a buffer;
370 	 * 4) if the DISABLE WRITE bit is set to zero, then write the logical
371 	 *    blocks transferred from the data-out buffer; and
372 	 * 5) transfer the resulting XOR data to the data-in buffer.
373 	 */
374 	buf = kmalloc(cmd->data_length, GFP_KERNEL);
375 	if (!buf) {
376 		pr_err("Unable to allocate xor_callback buf\n");
377 		return TCM_OUT_OF_RESOURCES;
378 	}
379 	/*
380 	 * Copy the scatterlist WRITE buffer located at cmd->t_data_sg
381 	 * into the locally allocated *buf
382 	 */
383 	sg_copy_to_buffer(cmd->t_data_sg,
384 			  cmd->t_data_nents,
385 			  buf,
386 			  cmd->data_length);
387 
388 	/*
389 	 * Now perform the XOR against the BIDI read memory located at
390 	 * cmd->t_mem_bidi_list
391 	 */
392 
393 	offset = 0;
394 	for_each_sg(cmd->t_bidi_data_sg, sg, cmd->t_bidi_data_nents, count) {
395 		addr = kmap_atomic(sg_page(sg));
396 		if (!addr) {
397 			ret = TCM_OUT_OF_RESOURCES;
398 			goto out;
399 		}
400 
401 		for (i = 0; i < sg->length; i++)
402 			*(addr + sg->offset + i) ^= *(buf + offset + i);
403 
404 		offset += sg->length;
405 		kunmap_atomic(addr);
406 	}
407 
408 out:
409 	kfree(buf);
410 	return ret;
411 }
412 
413 static sense_reason_t
414 sbc_execute_rw(struct se_cmd *cmd)
415 {
416 	struct sbc_ops *ops = cmd->protocol_data;
417 
418 	return ops->execute_rw(cmd, cmd->t_data_sg, cmd->t_data_nents,
419 			       cmd->data_direction);
420 }
421 
422 static sense_reason_t compare_and_write_post(struct se_cmd *cmd, bool success,
423 					     int *post_ret)
424 {
425 	struct se_device *dev = cmd->se_dev;
426 	sense_reason_t ret = TCM_NO_SENSE;
427 
428 	/*
429 	 * Only set SCF_COMPARE_AND_WRITE_POST to force a response fall-through
430 	 * within target_complete_ok_work() if the command was successfully
431 	 * sent to the backend driver.
432 	 */
433 	spin_lock_irq(&cmd->t_state_lock);
434 	if (cmd->transport_state & CMD_T_SENT) {
435 		cmd->se_cmd_flags |= SCF_COMPARE_AND_WRITE_POST;
436 		*post_ret = 1;
437 
438 		if (cmd->scsi_status == SAM_STAT_CHECK_CONDITION)
439 			ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
440 	}
441 	spin_unlock_irq(&cmd->t_state_lock);
442 
443 	/*
444 	 * Unlock ->caw_sem originally obtained during sbc_compare_and_write()
445 	 * before the original READ I/O submission.
446 	 */
447 	up(&dev->caw_sem);
448 
449 	return ret;
450 }
451 
452 static sense_reason_t compare_and_write_callback(struct se_cmd *cmd, bool success,
453 						 int *post_ret)
454 {
455 	struct se_device *dev = cmd->se_dev;
456 	struct scatterlist *write_sg = NULL, *sg;
457 	unsigned char *buf = NULL, *addr;
458 	struct sg_mapping_iter m;
459 	unsigned int offset = 0, len;
460 	unsigned int nlbas = cmd->t_task_nolb;
461 	unsigned int block_size = dev->dev_attrib.block_size;
462 	unsigned int compare_len = (nlbas * block_size);
463 	sense_reason_t ret = TCM_NO_SENSE;
464 	int rc, i;
465 
466 	/*
467 	 * Handle early failure in transport_generic_request_failure(),
468 	 * which will not have taken ->caw_sem yet..
469 	 */
470 	if (!success && (!cmd->t_data_sg || !cmd->t_bidi_data_sg))
471 		return TCM_NO_SENSE;
472 	/*
473 	 * Handle special case for zero-length COMPARE_AND_WRITE
474 	 */
475 	if (!cmd->data_length)
476 		goto out;
477 	/*
478 	 * Immediately exit + release dev->caw_sem if command has already
479 	 * been failed with a non-zero SCSI status.
480 	 */
481 	if (cmd->scsi_status) {
482 		pr_debug("compare_and_write_callback: non zero scsi_status:"
483 			" 0x%02x\n", cmd->scsi_status);
484 		*post_ret = 1;
485 		if (cmd->scsi_status == SAM_STAT_CHECK_CONDITION)
486 			ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
487 		goto out;
488 	}
489 
490 	buf = kzalloc(cmd->data_length, GFP_KERNEL);
491 	if (!buf) {
492 		pr_err("Unable to allocate compare_and_write buf\n");
493 		ret = TCM_OUT_OF_RESOURCES;
494 		goto out;
495 	}
496 
497 	write_sg = kmalloc_array(cmd->t_data_nents, sizeof(*write_sg),
498 				 GFP_KERNEL);
499 	if (!write_sg) {
500 		pr_err("Unable to allocate compare_and_write sg\n");
501 		ret = TCM_OUT_OF_RESOURCES;
502 		goto out;
503 	}
504 	sg_init_table(write_sg, cmd->t_data_nents);
505 	/*
506 	 * Setup verify and write data payloads from total NumberLBAs.
507 	 */
508 	rc = sg_copy_to_buffer(cmd->t_data_sg, cmd->t_data_nents, buf,
509 			       cmd->data_length);
510 	if (!rc) {
511 		pr_err("sg_copy_to_buffer() failed for compare_and_write\n");
512 		ret = TCM_OUT_OF_RESOURCES;
513 		goto out;
514 	}
515 	/*
516 	 * Compare against SCSI READ payload against verify payload
517 	 */
518 	for_each_sg(cmd->t_bidi_data_sg, sg, cmd->t_bidi_data_nents, i) {
519 		addr = (unsigned char *)kmap_atomic(sg_page(sg));
520 		if (!addr) {
521 			ret = TCM_OUT_OF_RESOURCES;
522 			goto out;
523 		}
524 
525 		len = min(sg->length, compare_len);
526 
527 		if (memcmp(addr, buf + offset, len)) {
528 			pr_warn("Detected MISCOMPARE for addr: %p buf: %p\n",
529 				addr, buf + offset);
530 			kunmap_atomic(addr);
531 			goto miscompare;
532 		}
533 		kunmap_atomic(addr);
534 
535 		offset += len;
536 		compare_len -= len;
537 		if (!compare_len)
538 			break;
539 	}
540 
541 	i = 0;
542 	len = cmd->t_task_nolb * block_size;
543 	sg_miter_start(&m, cmd->t_data_sg, cmd->t_data_nents, SG_MITER_TO_SG);
544 	/*
545 	 * Currently assumes NoLB=1 and SGLs are PAGE_SIZE..
546 	 */
547 	while (len) {
548 		sg_miter_next(&m);
549 
550 		if (block_size < PAGE_SIZE) {
551 			sg_set_page(&write_sg[i], m.page, block_size,
552 				    m.piter.sg->offset + block_size);
553 		} else {
554 			sg_miter_next(&m);
555 			sg_set_page(&write_sg[i], m.page, block_size,
556 				    m.piter.sg->offset);
557 		}
558 		len -= block_size;
559 		i++;
560 	}
561 	sg_miter_stop(&m);
562 	/*
563 	 * Save the original SGL + nents values before updating to new
564 	 * assignments, to be released in transport_free_pages() ->
565 	 * transport_reset_sgl_orig()
566 	 */
567 	cmd->t_data_sg_orig = cmd->t_data_sg;
568 	cmd->t_data_sg = write_sg;
569 	cmd->t_data_nents_orig = cmd->t_data_nents;
570 	cmd->t_data_nents = 1;
571 
572 	cmd->sam_task_attr = TCM_HEAD_TAG;
573 	cmd->transport_complete_callback = compare_and_write_post;
574 	/*
575 	 * Now reset ->execute_cmd() to the normal sbc_execute_rw() handler
576 	 * for submitting the adjusted SGL to write instance user-data.
577 	 */
578 	cmd->execute_cmd = sbc_execute_rw;
579 
580 	spin_lock_irq(&cmd->t_state_lock);
581 	cmd->t_state = TRANSPORT_PROCESSING;
582 	cmd->transport_state |= CMD_T_ACTIVE | CMD_T_SENT;
583 	spin_unlock_irq(&cmd->t_state_lock);
584 
585 	__target_execute_cmd(cmd, false);
586 
587 	kfree(buf);
588 	return ret;
589 
590 miscompare:
591 	pr_warn("Target/%s: Send MISCOMPARE check condition and sense\n",
592 		dev->transport->name);
593 	ret = TCM_MISCOMPARE_VERIFY;
594 out:
595 	/*
596 	 * In the MISCOMPARE or failure case, unlock ->caw_sem obtained in
597 	 * sbc_compare_and_write() before the original READ I/O submission.
598 	 */
599 	up(&dev->caw_sem);
600 	kfree(write_sg);
601 	kfree(buf);
602 	return ret;
603 }
604 
605 static sense_reason_t
606 sbc_compare_and_write(struct se_cmd *cmd)
607 {
608 	struct sbc_ops *ops = cmd->protocol_data;
609 	struct se_device *dev = cmd->se_dev;
610 	sense_reason_t ret;
611 	int rc;
612 	/*
613 	 * Submit the READ first for COMPARE_AND_WRITE to perform the
614 	 * comparision using SGLs at cmd->t_bidi_data_sg..
615 	 */
616 	rc = down_interruptible(&dev->caw_sem);
617 	if (rc != 0) {
618 		cmd->transport_complete_callback = NULL;
619 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
620 	}
621 	/*
622 	 * Reset cmd->data_length to individual block_size in order to not
623 	 * confuse backend drivers that depend on this value matching the
624 	 * size of the I/O being submitted.
625 	 */
626 	cmd->data_length = cmd->t_task_nolb * dev->dev_attrib.block_size;
627 
628 	ret = ops->execute_rw(cmd, cmd->t_bidi_data_sg, cmd->t_bidi_data_nents,
629 			      DMA_FROM_DEVICE);
630 	if (ret) {
631 		cmd->transport_complete_callback = NULL;
632 		up(&dev->caw_sem);
633 		return ret;
634 	}
635 	/*
636 	 * Unlock of dev->caw_sem to occur in compare_and_write_callback()
637 	 * upon MISCOMPARE, or in compare_and_write_done() upon completion
638 	 * of WRITE instance user-data.
639 	 */
640 	return TCM_NO_SENSE;
641 }
642 
643 static int
644 sbc_set_prot_op_checks(u8 protect, bool fabric_prot, enum target_prot_type prot_type,
645 		       bool is_write, struct se_cmd *cmd)
646 {
647 	if (is_write) {
648 		cmd->prot_op = fabric_prot ? TARGET_PROT_DOUT_STRIP :
649 			       protect ? TARGET_PROT_DOUT_PASS :
650 			       TARGET_PROT_DOUT_INSERT;
651 		switch (protect) {
652 		case 0x0:
653 		case 0x3:
654 			cmd->prot_checks = 0;
655 			break;
656 		case 0x1:
657 		case 0x5:
658 			cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
659 			if (prot_type == TARGET_DIF_TYPE1_PROT)
660 				cmd->prot_checks |= TARGET_DIF_CHECK_REFTAG;
661 			break;
662 		case 0x2:
663 			if (prot_type == TARGET_DIF_TYPE1_PROT)
664 				cmd->prot_checks = TARGET_DIF_CHECK_REFTAG;
665 			break;
666 		case 0x4:
667 			cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
668 			break;
669 		default:
670 			pr_err("Unsupported protect field %d\n", protect);
671 			return -EINVAL;
672 		}
673 	} else {
674 		cmd->prot_op = fabric_prot ? TARGET_PROT_DIN_INSERT :
675 			       protect ? TARGET_PROT_DIN_PASS :
676 			       TARGET_PROT_DIN_STRIP;
677 		switch (protect) {
678 		case 0x0:
679 		case 0x1:
680 		case 0x5:
681 			cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
682 			if (prot_type == TARGET_DIF_TYPE1_PROT)
683 				cmd->prot_checks |= TARGET_DIF_CHECK_REFTAG;
684 			break;
685 		case 0x2:
686 			if (prot_type == TARGET_DIF_TYPE1_PROT)
687 				cmd->prot_checks = TARGET_DIF_CHECK_REFTAG;
688 			break;
689 		case 0x3:
690 			cmd->prot_checks = 0;
691 			break;
692 		case 0x4:
693 			cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
694 			break;
695 		default:
696 			pr_err("Unsupported protect field %d\n", protect);
697 			return -EINVAL;
698 		}
699 	}
700 
701 	return 0;
702 }
703 
704 static sense_reason_t
705 sbc_check_prot(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb,
706 	       u32 sectors, bool is_write)
707 {
708 	u8 protect = cdb[1] >> 5;
709 	int sp_ops = cmd->se_sess->sup_prot_ops;
710 	int pi_prot_type = dev->dev_attrib.pi_prot_type;
711 	bool fabric_prot = false;
712 
713 	if (!cmd->t_prot_sg || !cmd->t_prot_nents) {
714 		if (unlikely(protect &&
715 		    !dev->dev_attrib.pi_prot_type && !cmd->se_sess->sess_prot_type)) {
716 			pr_err("CDB contains protect bit, but device + fabric does"
717 			       " not advertise PROTECT=1 feature bit\n");
718 			return TCM_INVALID_CDB_FIELD;
719 		}
720 		if (cmd->prot_pto)
721 			return TCM_NO_SENSE;
722 	}
723 
724 	switch (dev->dev_attrib.pi_prot_type) {
725 	case TARGET_DIF_TYPE3_PROT:
726 		cmd->reftag_seed = 0xffffffff;
727 		break;
728 	case TARGET_DIF_TYPE2_PROT:
729 		if (protect)
730 			return TCM_INVALID_CDB_FIELD;
731 
732 		cmd->reftag_seed = cmd->t_task_lba;
733 		break;
734 	case TARGET_DIF_TYPE1_PROT:
735 		cmd->reftag_seed = cmd->t_task_lba;
736 		break;
737 	case TARGET_DIF_TYPE0_PROT:
738 		/*
739 		 * See if the fabric supports T10-PI, and the session has been
740 		 * configured to allow export PROTECT=1 feature bit with backend
741 		 * devices that don't support T10-PI.
742 		 */
743 		fabric_prot = is_write ?
744 			      !!(sp_ops & (TARGET_PROT_DOUT_PASS | TARGET_PROT_DOUT_STRIP)) :
745 			      !!(sp_ops & (TARGET_PROT_DIN_PASS | TARGET_PROT_DIN_INSERT));
746 
747 		if (fabric_prot && cmd->se_sess->sess_prot_type) {
748 			pi_prot_type = cmd->se_sess->sess_prot_type;
749 			break;
750 		}
751 		if (!protect)
752 			return TCM_NO_SENSE;
753 		/* Fallthrough */
754 	default:
755 		pr_err("Unable to determine pi_prot_type for CDB: 0x%02x "
756 		       "PROTECT: 0x%02x\n", cdb[0], protect);
757 		return TCM_INVALID_CDB_FIELD;
758 	}
759 
760 	if (sbc_set_prot_op_checks(protect, fabric_prot, pi_prot_type, is_write, cmd))
761 		return TCM_INVALID_CDB_FIELD;
762 
763 	cmd->prot_type = pi_prot_type;
764 	cmd->prot_length = dev->prot_length * sectors;
765 
766 	/**
767 	 * In case protection information exists over the wire
768 	 * we modify command data length to describe pure data.
769 	 * The actual transfer length is data length + protection
770 	 * length
771 	 **/
772 	if (protect)
773 		cmd->data_length = sectors * dev->dev_attrib.block_size;
774 
775 	pr_debug("%s: prot_type=%d, data_length=%d, prot_length=%d "
776 		 "prot_op=%d prot_checks=%d\n",
777 		 __func__, cmd->prot_type, cmd->data_length, cmd->prot_length,
778 		 cmd->prot_op, cmd->prot_checks);
779 
780 	return TCM_NO_SENSE;
781 }
782 
783 static int
784 sbc_check_dpofua(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb)
785 {
786 	if (cdb[1] & 0x10) {
787 		/* see explanation in spc_emulate_modesense */
788 		if (!target_check_fua(dev)) {
789 			pr_err("Got CDB: 0x%02x with DPO bit set, but device"
790 			       " does not advertise support for DPO\n", cdb[0]);
791 			return -EINVAL;
792 		}
793 	}
794 	if (cdb[1] & 0x8) {
795 		if (!target_check_fua(dev)) {
796 			pr_err("Got CDB: 0x%02x with FUA bit set, but device"
797 			       " does not advertise support for FUA write\n",
798 			       cdb[0]);
799 			return -EINVAL;
800 		}
801 		cmd->se_cmd_flags |= SCF_FUA;
802 	}
803 	return 0;
804 }
805 
806 sense_reason_t
807 sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
808 {
809 	struct se_device *dev = cmd->se_dev;
810 	unsigned char *cdb = cmd->t_task_cdb;
811 	unsigned int size;
812 	u32 sectors = 0;
813 	sense_reason_t ret;
814 
815 	cmd->protocol_data = ops;
816 
817 	switch (cdb[0]) {
818 	case READ_6:
819 		sectors = transport_get_sectors_6(cdb);
820 		cmd->t_task_lba = transport_lba_21(cdb);
821 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
822 		cmd->execute_cmd = sbc_execute_rw;
823 		break;
824 	case READ_10:
825 		sectors = transport_get_sectors_10(cdb);
826 		cmd->t_task_lba = transport_lba_32(cdb);
827 
828 		if (sbc_check_dpofua(dev, cmd, cdb))
829 			return TCM_INVALID_CDB_FIELD;
830 
831 		ret = sbc_check_prot(dev, cmd, cdb, sectors, false);
832 		if (ret)
833 			return ret;
834 
835 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
836 		cmd->execute_cmd = sbc_execute_rw;
837 		break;
838 	case READ_12:
839 		sectors = transport_get_sectors_12(cdb);
840 		cmd->t_task_lba = transport_lba_32(cdb);
841 
842 		if (sbc_check_dpofua(dev, cmd, cdb))
843 			return TCM_INVALID_CDB_FIELD;
844 
845 		ret = sbc_check_prot(dev, cmd, cdb, sectors, false);
846 		if (ret)
847 			return ret;
848 
849 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
850 		cmd->execute_cmd = sbc_execute_rw;
851 		break;
852 	case READ_16:
853 		sectors = transport_get_sectors_16(cdb);
854 		cmd->t_task_lba = transport_lba_64(cdb);
855 
856 		if (sbc_check_dpofua(dev, cmd, cdb))
857 			return TCM_INVALID_CDB_FIELD;
858 
859 		ret = sbc_check_prot(dev, cmd, cdb, sectors, false);
860 		if (ret)
861 			return ret;
862 
863 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
864 		cmd->execute_cmd = sbc_execute_rw;
865 		break;
866 	case WRITE_6:
867 		sectors = transport_get_sectors_6(cdb);
868 		cmd->t_task_lba = transport_lba_21(cdb);
869 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
870 		cmd->execute_cmd = sbc_execute_rw;
871 		break;
872 	case WRITE_10:
873 	case WRITE_VERIFY:
874 		sectors = transport_get_sectors_10(cdb);
875 		cmd->t_task_lba = transport_lba_32(cdb);
876 
877 		if (sbc_check_dpofua(dev, cmd, cdb))
878 			return TCM_INVALID_CDB_FIELD;
879 
880 		ret = sbc_check_prot(dev, cmd, cdb, sectors, true);
881 		if (ret)
882 			return ret;
883 
884 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
885 		cmd->execute_cmd = sbc_execute_rw;
886 		break;
887 	case WRITE_12:
888 		sectors = transport_get_sectors_12(cdb);
889 		cmd->t_task_lba = transport_lba_32(cdb);
890 
891 		if (sbc_check_dpofua(dev, cmd, cdb))
892 			return TCM_INVALID_CDB_FIELD;
893 
894 		ret = sbc_check_prot(dev, cmd, cdb, sectors, true);
895 		if (ret)
896 			return ret;
897 
898 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
899 		cmd->execute_cmd = sbc_execute_rw;
900 		break;
901 	case WRITE_16:
902 	case WRITE_VERIFY_16:
903 		sectors = transport_get_sectors_16(cdb);
904 		cmd->t_task_lba = transport_lba_64(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 XDWRITEREAD_10:
917 		if (cmd->data_direction != DMA_TO_DEVICE ||
918 		    !(cmd->se_cmd_flags & SCF_BIDI))
919 			return TCM_INVALID_CDB_FIELD;
920 		sectors = transport_get_sectors_10(cdb);
921 
922 		if (sbc_check_dpofua(dev, cmd, cdb))
923 			return TCM_INVALID_CDB_FIELD;
924 
925 		cmd->t_task_lba = transport_lba_32(cdb);
926 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
927 
928 		/*
929 		 * Setup BIDI XOR callback to be run after I/O completion.
930 		 */
931 		cmd->execute_cmd = sbc_execute_rw;
932 		cmd->transport_complete_callback = &xdreadwrite_callback;
933 		break;
934 	case VARIABLE_LENGTH_CMD:
935 	{
936 		u16 service_action = get_unaligned_be16(&cdb[8]);
937 		switch (service_action) {
938 		case XDWRITEREAD_32:
939 			sectors = transport_get_sectors_32(cdb);
940 
941 			if (sbc_check_dpofua(dev, cmd, cdb))
942 				return TCM_INVALID_CDB_FIELD;
943 			/*
944 			 * Use WRITE_32 and READ_32 opcodes for the emulated
945 			 * XDWRITE_READ_32 logic.
946 			 */
947 			cmd->t_task_lba = transport_lba_64_ext(cdb);
948 			cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
949 
950 			/*
951 			 * Setup BIDI XOR callback to be run during after I/O
952 			 * completion.
953 			 */
954 			cmd->execute_cmd = sbc_execute_rw;
955 			cmd->transport_complete_callback = &xdreadwrite_callback;
956 			break;
957 		case WRITE_SAME_32:
958 			sectors = transport_get_sectors_32(cdb);
959 			if (!sectors) {
960 				pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not"
961 				       " supported\n");
962 				return TCM_INVALID_CDB_FIELD;
963 			}
964 
965 			size = sbc_get_size(cmd, 1);
966 			cmd->t_task_lba = get_unaligned_be64(&cdb[12]);
967 
968 			ret = sbc_setup_write_same(cmd, &cdb[10], ops);
969 			if (ret)
970 				return ret;
971 			break;
972 		default:
973 			pr_err("VARIABLE_LENGTH_CMD service action"
974 				" 0x%04x not supported\n", service_action);
975 			return TCM_UNSUPPORTED_SCSI_OPCODE;
976 		}
977 		break;
978 	}
979 	case COMPARE_AND_WRITE:
980 		if (!dev->dev_attrib.emulate_caw) {
981 			pr_err_ratelimited("se_device %s/%s (vpd_unit_serial %s) reject"
982 				" COMPARE_AND_WRITE\n", dev->se_hba->backend->ops->name,
983 				dev->dev_group.cg_item.ci_name, dev->t10_wwn.unit_serial);
984 			return TCM_UNSUPPORTED_SCSI_OPCODE;
985 		}
986 		sectors = cdb[13];
987 		/*
988 		 * Currently enforce COMPARE_AND_WRITE for a single sector
989 		 */
990 		if (sectors > 1) {
991 			pr_err("COMPARE_AND_WRITE contains NoLB: %u greater"
992 			       " than 1\n", sectors);
993 			return TCM_INVALID_CDB_FIELD;
994 		}
995 		if (sbc_check_dpofua(dev, cmd, cdb))
996 			return TCM_INVALID_CDB_FIELD;
997 
998 		/*
999 		 * Double size because we have two buffers, note that
1000 		 * zero is not an error..
1001 		 */
1002 		size = 2 * sbc_get_size(cmd, sectors);
1003 		cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
1004 		cmd->t_task_nolb = sectors;
1005 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB | SCF_COMPARE_AND_WRITE;
1006 		cmd->execute_cmd = sbc_compare_and_write;
1007 		cmd->transport_complete_callback = compare_and_write_callback;
1008 		break;
1009 	case READ_CAPACITY:
1010 		size = READ_CAP_LEN;
1011 		cmd->execute_cmd = sbc_emulate_readcapacity;
1012 		break;
1013 	case SERVICE_ACTION_IN_16:
1014 		switch (cmd->t_task_cdb[1] & 0x1f) {
1015 		case SAI_READ_CAPACITY_16:
1016 			cmd->execute_cmd = sbc_emulate_readcapacity_16;
1017 			break;
1018 		case SAI_REPORT_REFERRALS:
1019 			cmd->execute_cmd = target_emulate_report_referrals;
1020 			break;
1021 		default:
1022 			pr_err("Unsupported SA: 0x%02x\n",
1023 				cmd->t_task_cdb[1] & 0x1f);
1024 			return TCM_INVALID_CDB_FIELD;
1025 		}
1026 		size = get_unaligned_be32(&cdb[10]);
1027 		break;
1028 	case SYNCHRONIZE_CACHE:
1029 	case SYNCHRONIZE_CACHE_16:
1030 		if (cdb[0] == SYNCHRONIZE_CACHE) {
1031 			sectors = transport_get_sectors_10(cdb);
1032 			cmd->t_task_lba = transport_lba_32(cdb);
1033 		} else {
1034 			sectors = transport_get_sectors_16(cdb);
1035 			cmd->t_task_lba = transport_lba_64(cdb);
1036 		}
1037 		if (ops->execute_sync_cache) {
1038 			cmd->execute_cmd = ops->execute_sync_cache;
1039 			goto check_lba;
1040 		}
1041 		size = 0;
1042 		cmd->execute_cmd = sbc_emulate_noop;
1043 		break;
1044 	case UNMAP:
1045 		if (!ops->execute_unmap)
1046 			return TCM_UNSUPPORTED_SCSI_OPCODE;
1047 
1048 		if (!dev->dev_attrib.emulate_tpu) {
1049 			pr_err("Got UNMAP, but backend device has"
1050 			       " emulate_tpu disabled\n");
1051 			return TCM_UNSUPPORTED_SCSI_OPCODE;
1052 		}
1053 		size = get_unaligned_be16(&cdb[7]);
1054 		cmd->execute_cmd = sbc_execute_unmap;
1055 		break;
1056 	case WRITE_SAME_16:
1057 		sectors = transport_get_sectors_16(cdb);
1058 		if (!sectors) {
1059 			pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
1060 			return TCM_INVALID_CDB_FIELD;
1061 		}
1062 
1063 		size = sbc_get_size(cmd, 1);
1064 		cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
1065 
1066 		ret = sbc_setup_write_same(cmd, &cdb[1], ops);
1067 		if (ret)
1068 			return ret;
1069 		break;
1070 	case WRITE_SAME:
1071 		sectors = transport_get_sectors_10(cdb);
1072 		if (!sectors) {
1073 			pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
1074 			return TCM_INVALID_CDB_FIELD;
1075 		}
1076 
1077 		size = sbc_get_size(cmd, 1);
1078 		cmd->t_task_lba = get_unaligned_be32(&cdb[2]);
1079 
1080 		/*
1081 		 * Follow sbcr26 with WRITE_SAME (10) and check for the existence
1082 		 * of byte 1 bit 3 UNMAP instead of original reserved field
1083 		 */
1084 		ret = sbc_setup_write_same(cmd, &cdb[1], ops);
1085 		if (ret)
1086 			return ret;
1087 		break;
1088 	case VERIFY:
1089 	case VERIFY_16:
1090 		size = 0;
1091 		if (cdb[0] == VERIFY) {
1092 			sectors = transport_get_sectors_10(cdb);
1093 			cmd->t_task_lba = transport_lba_32(cdb);
1094 		} else {
1095 			sectors = transport_get_sectors_16(cdb);
1096 			cmd->t_task_lba = transport_lba_64(cdb);
1097 		}
1098 		cmd->execute_cmd = sbc_emulate_noop;
1099 		goto check_lba;
1100 	case REZERO_UNIT:
1101 	case SEEK_6:
1102 	case SEEK_10:
1103 		/*
1104 		 * There are still clients out there which use these old SCSI-2
1105 		 * commands. This mainly happens when running VMs with legacy
1106 		 * guest systems, connected via SCSI command pass-through to
1107 		 * iSCSI targets. Make them happy and return status GOOD.
1108 		 */
1109 		size = 0;
1110 		cmd->execute_cmd = sbc_emulate_noop;
1111 		break;
1112 	case START_STOP:
1113 		size = 0;
1114 		cmd->execute_cmd = sbc_emulate_startstop;
1115 		break;
1116 	default:
1117 		ret = spc_parse_cdb(cmd, &size);
1118 		if (ret)
1119 			return ret;
1120 	}
1121 
1122 	/* reject any command that we don't have a handler for */
1123 	if (!cmd->execute_cmd)
1124 		return TCM_UNSUPPORTED_SCSI_OPCODE;
1125 
1126 	if (cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
1127 		unsigned long long end_lba;
1128 check_lba:
1129 		end_lba = dev->transport->get_blocks(dev) + 1;
1130 		if (((cmd->t_task_lba + sectors) < cmd->t_task_lba) ||
1131 		    ((cmd->t_task_lba + sectors) > end_lba)) {
1132 			pr_err("cmd exceeds last lba %llu "
1133 				"(lba %llu, sectors %u)\n",
1134 				end_lba, cmd->t_task_lba, sectors);
1135 			return TCM_ADDRESS_OUT_OF_RANGE;
1136 		}
1137 
1138 		if (!(cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE))
1139 			size = sbc_get_size(cmd, sectors);
1140 	}
1141 
1142 	return target_cmd_size_check(cmd, size);
1143 }
1144 EXPORT_SYMBOL(sbc_parse_cdb);
1145 
1146 u32 sbc_get_device_type(struct se_device *dev)
1147 {
1148 	return TYPE_DISK;
1149 }
1150 EXPORT_SYMBOL(sbc_get_device_type);
1151 
1152 static sense_reason_t
1153 sbc_execute_unmap(struct se_cmd *cmd)
1154 {
1155 	struct sbc_ops *ops = cmd->protocol_data;
1156 	struct se_device *dev = cmd->se_dev;
1157 	unsigned char *buf, *ptr = NULL;
1158 	sector_t lba;
1159 	int size;
1160 	u32 range;
1161 	sense_reason_t ret = 0;
1162 	int dl, bd_dl;
1163 
1164 	/* We never set ANC_SUP */
1165 	if (cmd->t_task_cdb[1])
1166 		return TCM_INVALID_CDB_FIELD;
1167 
1168 	if (cmd->data_length == 0) {
1169 		target_complete_cmd(cmd, SAM_STAT_GOOD);
1170 		return 0;
1171 	}
1172 
1173 	if (cmd->data_length < 8) {
1174 		pr_warn("UNMAP parameter list length %u too small\n",
1175 			cmd->data_length);
1176 		return TCM_PARAMETER_LIST_LENGTH_ERROR;
1177 	}
1178 
1179 	buf = transport_kmap_data_sg(cmd);
1180 	if (!buf)
1181 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1182 
1183 	dl = get_unaligned_be16(&buf[0]);
1184 	bd_dl = get_unaligned_be16(&buf[2]);
1185 
1186 	size = cmd->data_length - 8;
1187 	if (bd_dl > size)
1188 		pr_warn("UNMAP parameter list length %u too small, ignoring bd_dl %u\n",
1189 			cmd->data_length, bd_dl);
1190 	else
1191 		size = bd_dl;
1192 
1193 	if (size / 16 > dev->dev_attrib.max_unmap_block_desc_count) {
1194 		ret = TCM_INVALID_PARAMETER_LIST;
1195 		goto err;
1196 	}
1197 
1198 	/* First UNMAP block descriptor starts at 8 byte offset */
1199 	ptr = &buf[8];
1200 	pr_debug("UNMAP: Sub: %s Using dl: %u bd_dl: %u size: %u"
1201 		" ptr: %p\n", dev->transport->name, dl, bd_dl, size, ptr);
1202 
1203 	while (size >= 16) {
1204 		lba = get_unaligned_be64(&ptr[0]);
1205 		range = get_unaligned_be32(&ptr[8]);
1206 		pr_debug("UNMAP: Using lba: %llu and range: %u\n",
1207 				 (unsigned long long)lba, range);
1208 
1209 		if (range > dev->dev_attrib.max_unmap_lba_count) {
1210 			ret = TCM_INVALID_PARAMETER_LIST;
1211 			goto err;
1212 		}
1213 
1214 		if (lba + range > dev->transport->get_blocks(dev) + 1) {
1215 			ret = TCM_ADDRESS_OUT_OF_RANGE;
1216 			goto err;
1217 		}
1218 
1219 		if (range) {
1220 			ret = ops->execute_unmap(cmd, lba, range);
1221 			if (ret)
1222 				goto err;
1223 		}
1224 
1225 		ptr += 16;
1226 		size -= 16;
1227 	}
1228 
1229 err:
1230 	transport_kunmap_data_sg(cmd);
1231 	if (!ret)
1232 		target_complete_cmd(cmd, GOOD);
1233 	return ret;
1234 }
1235 
1236 void
1237 sbc_dif_generate(struct se_cmd *cmd)
1238 {
1239 	struct se_device *dev = cmd->se_dev;
1240 	struct t10_pi_tuple *sdt;
1241 	struct scatterlist *dsg = cmd->t_data_sg, *psg;
1242 	sector_t sector = cmd->t_task_lba;
1243 	void *daddr, *paddr;
1244 	int i, j, offset = 0;
1245 	unsigned int block_size = dev->dev_attrib.block_size;
1246 
1247 	for_each_sg(cmd->t_prot_sg, psg, cmd->t_prot_nents, i) {
1248 		paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1249 		daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1250 
1251 		for (j = 0; j < psg->length;
1252 				j += sizeof(*sdt)) {
1253 			__u16 crc;
1254 			unsigned int avail;
1255 
1256 			if (offset >= dsg->length) {
1257 				offset -= dsg->length;
1258 				kunmap_atomic(daddr - dsg->offset);
1259 				dsg = sg_next(dsg);
1260 				if (!dsg) {
1261 					kunmap_atomic(paddr - psg->offset);
1262 					return;
1263 				}
1264 				daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1265 			}
1266 
1267 			sdt = paddr + j;
1268 			avail = min(block_size, dsg->length - offset);
1269 			crc = crc_t10dif(daddr + offset, avail);
1270 			if (avail < block_size) {
1271 				kunmap_atomic(daddr - dsg->offset);
1272 				dsg = sg_next(dsg);
1273 				if (!dsg) {
1274 					kunmap_atomic(paddr - psg->offset);
1275 					return;
1276 				}
1277 				daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1278 				offset = block_size - avail;
1279 				crc = crc_t10dif_update(crc, daddr, offset);
1280 			} else {
1281 				offset += block_size;
1282 			}
1283 
1284 			sdt->guard_tag = cpu_to_be16(crc);
1285 			if (cmd->prot_type == TARGET_DIF_TYPE1_PROT)
1286 				sdt->ref_tag = cpu_to_be32(sector & 0xffffffff);
1287 			sdt->app_tag = 0;
1288 
1289 			pr_debug("DIF %s INSERT sector: %llu guard_tag: 0x%04x"
1290 				 " app_tag: 0x%04x ref_tag: %u\n",
1291 				 (cmd->data_direction == DMA_TO_DEVICE) ?
1292 				 "WRITE" : "READ", (unsigned long long)sector,
1293 				 sdt->guard_tag, sdt->app_tag,
1294 				 be32_to_cpu(sdt->ref_tag));
1295 
1296 			sector++;
1297 		}
1298 
1299 		kunmap_atomic(daddr - dsg->offset);
1300 		kunmap_atomic(paddr - psg->offset);
1301 	}
1302 }
1303 
1304 static sense_reason_t
1305 sbc_dif_v1_verify(struct se_cmd *cmd, struct t10_pi_tuple *sdt,
1306 		  __u16 crc, sector_t sector, unsigned int ei_lba)
1307 {
1308 	__be16 csum;
1309 
1310 	if (!(cmd->prot_checks & TARGET_DIF_CHECK_GUARD))
1311 		goto check_ref;
1312 
1313 	csum = cpu_to_be16(crc);
1314 
1315 	if (sdt->guard_tag != csum) {
1316 		pr_err("DIFv1 checksum failed on sector %llu guard tag 0x%04x"
1317 			" csum 0x%04x\n", (unsigned long long)sector,
1318 			be16_to_cpu(sdt->guard_tag), be16_to_cpu(csum));
1319 		return TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED;
1320 	}
1321 
1322 check_ref:
1323 	if (!(cmd->prot_checks & TARGET_DIF_CHECK_REFTAG))
1324 		return 0;
1325 
1326 	if (cmd->prot_type == TARGET_DIF_TYPE1_PROT &&
1327 	    be32_to_cpu(sdt->ref_tag) != (sector & 0xffffffff)) {
1328 		pr_err("DIFv1 Type 1 reference failed on sector: %llu tag: 0x%08x"
1329 		       " sector MSB: 0x%08x\n", (unsigned long long)sector,
1330 		       be32_to_cpu(sdt->ref_tag), (u32)(sector & 0xffffffff));
1331 		return TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;
1332 	}
1333 
1334 	if (cmd->prot_type == TARGET_DIF_TYPE2_PROT &&
1335 	    be32_to_cpu(sdt->ref_tag) != ei_lba) {
1336 		pr_err("DIFv1 Type 2 reference failed on sector: %llu tag: 0x%08x"
1337 		       " ei_lba: 0x%08x\n", (unsigned long long)sector,
1338 			be32_to_cpu(sdt->ref_tag), ei_lba);
1339 		return TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;
1340 	}
1341 
1342 	return 0;
1343 }
1344 
1345 void sbc_dif_copy_prot(struct se_cmd *cmd, unsigned int sectors, bool read,
1346 		       struct scatterlist *sg, int sg_off)
1347 {
1348 	struct se_device *dev = cmd->se_dev;
1349 	struct scatterlist *psg;
1350 	void *paddr, *addr;
1351 	unsigned int i, len, left;
1352 	unsigned int offset = sg_off;
1353 
1354 	if (!sg)
1355 		return;
1356 
1357 	left = sectors * dev->prot_length;
1358 
1359 	for_each_sg(cmd->t_prot_sg, psg, cmd->t_prot_nents, i) {
1360 		unsigned int psg_len, copied = 0;
1361 
1362 		paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1363 		psg_len = min(left, psg->length);
1364 		while (psg_len) {
1365 			len = min(psg_len, sg->length - offset);
1366 			addr = kmap_atomic(sg_page(sg)) + sg->offset + offset;
1367 
1368 			if (read)
1369 				memcpy(paddr + copied, addr, len);
1370 			else
1371 				memcpy(addr, paddr + copied, len);
1372 
1373 			left -= len;
1374 			offset += len;
1375 			copied += len;
1376 			psg_len -= len;
1377 
1378 			kunmap_atomic(addr - sg->offset - offset);
1379 
1380 			if (offset >= sg->length) {
1381 				sg = sg_next(sg);
1382 				offset = 0;
1383 			}
1384 		}
1385 		kunmap_atomic(paddr - psg->offset);
1386 	}
1387 }
1388 EXPORT_SYMBOL(sbc_dif_copy_prot);
1389 
1390 sense_reason_t
1391 sbc_dif_verify(struct se_cmd *cmd, sector_t start, unsigned int sectors,
1392 	       unsigned int ei_lba, struct scatterlist *psg, int psg_off)
1393 {
1394 	struct se_device *dev = cmd->se_dev;
1395 	struct t10_pi_tuple *sdt;
1396 	struct scatterlist *dsg = cmd->t_data_sg;
1397 	sector_t sector = start;
1398 	void *daddr, *paddr;
1399 	int i;
1400 	sense_reason_t rc;
1401 	int dsg_off = 0;
1402 	unsigned int block_size = dev->dev_attrib.block_size;
1403 
1404 	for (; psg && sector < start + sectors; psg = sg_next(psg)) {
1405 		paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1406 		daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1407 
1408 		for (i = psg_off; i < psg->length &&
1409 				sector < start + sectors;
1410 				i += sizeof(*sdt)) {
1411 			__u16 crc;
1412 			unsigned int avail;
1413 
1414 			if (dsg_off >= dsg->length) {
1415 				dsg_off -= dsg->length;
1416 				kunmap_atomic(daddr - dsg->offset);
1417 				dsg = sg_next(dsg);
1418 				if (!dsg) {
1419 					kunmap_atomic(paddr - psg->offset);
1420 					return 0;
1421 				}
1422 				daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1423 			}
1424 
1425 			sdt = paddr + i;
1426 
1427 			pr_debug("DIF READ sector: %llu guard_tag: 0x%04x"
1428 				 " app_tag: 0x%04x ref_tag: %u\n",
1429 				 (unsigned long long)sector, sdt->guard_tag,
1430 				 sdt->app_tag, be32_to_cpu(sdt->ref_tag));
1431 
1432 			if (sdt->app_tag == T10_PI_APP_ESCAPE) {
1433 				dsg_off += block_size;
1434 				goto next;
1435 			}
1436 
1437 			avail = min(block_size, dsg->length - dsg_off);
1438 			crc = crc_t10dif(daddr + dsg_off, avail);
1439 			if (avail < block_size) {
1440 				kunmap_atomic(daddr - dsg->offset);
1441 				dsg = sg_next(dsg);
1442 				if (!dsg) {
1443 					kunmap_atomic(paddr - psg->offset);
1444 					return 0;
1445 				}
1446 				daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1447 				dsg_off = block_size - avail;
1448 				crc = crc_t10dif_update(crc, daddr, dsg_off);
1449 			} else {
1450 				dsg_off += block_size;
1451 			}
1452 
1453 			rc = sbc_dif_v1_verify(cmd, sdt, crc, sector, ei_lba);
1454 			if (rc) {
1455 				kunmap_atomic(daddr - dsg->offset);
1456 				kunmap_atomic(paddr - psg->offset);
1457 				cmd->bad_sector = sector;
1458 				return rc;
1459 			}
1460 next:
1461 			sector++;
1462 			ei_lba++;
1463 		}
1464 
1465 		psg_off = 0;
1466 		kunmap_atomic(daddr - dsg->offset);
1467 		kunmap_atomic(paddr - psg->offset);
1468 	}
1469 
1470 	return 0;
1471 }
1472 EXPORT_SYMBOL(sbc_dif_verify);
1473