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_proto.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_check_prot(struct se_device *, struct se_cmd *, unsigned char *, u32, bool);
41 static sense_reason_t sbc_execute_unmap(struct se_cmd *cmd);
42 
43 static sense_reason_t
44 sbc_emulate_readcapacity(struct se_cmd *cmd)
45 {
46 	struct se_device *dev = cmd->se_dev;
47 	unsigned char *cdb = cmd->t_task_cdb;
48 	unsigned long long blocks_long = dev->transport->get_blocks(dev);
49 	unsigned char *rbuf;
50 	unsigned char buf[8];
51 	u32 blocks;
52 
53 	/*
54 	 * SBC-2 says:
55 	 *   If the PMI bit is set to zero and the LOGICAL BLOCK
56 	 *   ADDRESS field is not set to zero, the device server shall
57 	 *   terminate the command with CHECK CONDITION status with
58 	 *   the sense key set to ILLEGAL REQUEST and the additional
59 	 *   sense code set to INVALID FIELD IN CDB.
60 	 *
61 	 * In SBC-3, these fields are obsolete, but some SCSI
62 	 * compliance tests actually check this, so we might as well
63 	 * follow SBC-2.
64 	 */
65 	if (!(cdb[8] & 1) && !!(cdb[2] | cdb[3] | cdb[4] | cdb[5]))
66 		return TCM_INVALID_CDB_FIELD;
67 
68 	if (blocks_long >= 0x00000000ffffffff)
69 		blocks = 0xffffffff;
70 	else
71 		blocks = (u32)blocks_long;
72 
73 	buf[0] = (blocks >> 24) & 0xff;
74 	buf[1] = (blocks >> 16) & 0xff;
75 	buf[2] = (blocks >> 8) & 0xff;
76 	buf[3] = blocks & 0xff;
77 	buf[4] = (dev->dev_attrib.block_size >> 24) & 0xff;
78 	buf[5] = (dev->dev_attrib.block_size >> 16) & 0xff;
79 	buf[6] = (dev->dev_attrib.block_size >> 8) & 0xff;
80 	buf[7] = dev->dev_attrib.block_size & 0xff;
81 
82 	rbuf = transport_kmap_data_sg(cmd);
83 	if (rbuf) {
84 		memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length));
85 		transport_kunmap_data_sg(cmd);
86 	}
87 
88 	target_complete_cmd_with_length(cmd, GOOD, 8);
89 	return 0;
90 }
91 
92 static sense_reason_t
93 sbc_emulate_readcapacity_16(struct se_cmd *cmd)
94 {
95 	struct se_device *dev = cmd->se_dev;
96 	struct se_session *sess = cmd->se_sess;
97 	int pi_prot_type = dev->dev_attrib.pi_prot_type;
98 
99 	unsigned char *rbuf;
100 	unsigned char buf[32];
101 	unsigned long long blocks = dev->transport->get_blocks(dev);
102 
103 	memset(buf, 0, sizeof(buf));
104 	buf[0] = (blocks >> 56) & 0xff;
105 	buf[1] = (blocks >> 48) & 0xff;
106 	buf[2] = (blocks >> 40) & 0xff;
107 	buf[3] = (blocks >> 32) & 0xff;
108 	buf[4] = (blocks >> 24) & 0xff;
109 	buf[5] = (blocks >> 16) & 0xff;
110 	buf[6] = (blocks >> 8) & 0xff;
111 	buf[7] = blocks & 0xff;
112 	buf[8] = (dev->dev_attrib.block_size >> 24) & 0xff;
113 	buf[9] = (dev->dev_attrib.block_size >> 16) & 0xff;
114 	buf[10] = (dev->dev_attrib.block_size >> 8) & 0xff;
115 	buf[11] = dev->dev_attrib.block_size & 0xff;
116 	/*
117 	 * Set P_TYPE and PROT_EN bits for DIF support
118 	 */
119 	if (sess->sup_prot_ops & (TARGET_PROT_DIN_PASS | TARGET_PROT_DOUT_PASS)) {
120 		/*
121 		 * Only override a device's pi_prot_type if no T10-PI is
122 		 * available, and sess_prot_type has been explicitly enabled.
123 		 */
124 		if (!pi_prot_type)
125 			pi_prot_type = sess->sess_prot_type;
126 
127 		if (pi_prot_type)
128 			buf[12] = (pi_prot_type - 1) << 1 | 0x1;
129 	}
130 
131 	if (dev->transport->get_lbppbe)
132 		buf[13] = dev->transport->get_lbppbe(dev) & 0x0f;
133 
134 	if (dev->transport->get_alignment_offset_lbas) {
135 		u16 lalba = dev->transport->get_alignment_offset_lbas(dev);
136 		buf[14] = (lalba >> 8) & 0x3f;
137 		buf[15] = lalba & 0xff;
138 	}
139 
140 	/*
141 	 * Set Thin Provisioning Enable bit following sbc3r22 in section
142 	 * READ CAPACITY (16) byte 14 if emulate_tpu or emulate_tpws is enabled.
143 	 */
144 	if (dev->dev_attrib.emulate_tpu || dev->dev_attrib.emulate_tpws)
145 		buf[14] |= 0x80;
146 
147 	rbuf = transport_kmap_data_sg(cmd);
148 	if (rbuf) {
149 		memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length));
150 		transport_kunmap_data_sg(cmd);
151 	}
152 
153 	target_complete_cmd_with_length(cmd, GOOD, 32);
154 	return 0;
155 }
156 
157 static sense_reason_t
158 sbc_emulate_startstop(struct se_cmd *cmd)
159 {
160 	unsigned char *cdb = cmd->t_task_cdb;
161 
162 	/*
163 	 * See sbc3r36 section 5.25
164 	 * Immediate bit should be set since there is nothing to complete
165 	 * POWER CONDITION MODIFIER 0h
166 	 */
167 	if (!(cdb[1] & 1) || cdb[2] || cdb[3])
168 		return TCM_INVALID_CDB_FIELD;
169 
170 	/*
171 	 * See sbc3r36 section 5.25
172 	 * POWER CONDITION 0h START_VALID - process START and LOEJ
173 	 */
174 	if (cdb[4] >> 4 & 0xf)
175 		return TCM_INVALID_CDB_FIELD;
176 
177 	/*
178 	 * See sbc3r36 section 5.25
179 	 * LOEJ 0h - nothing to load or unload
180 	 * START 1h - we are ready
181 	 */
182 	if (!(cdb[4] & 1) || (cdb[4] & 2) || (cdb[4] & 4))
183 		return TCM_INVALID_CDB_FIELD;
184 
185 	target_complete_cmd(cmd, SAM_STAT_GOOD);
186 	return 0;
187 }
188 
189 sector_t sbc_get_write_same_sectors(struct se_cmd *cmd)
190 {
191 	u32 num_blocks;
192 
193 	if (cmd->t_task_cdb[0] == WRITE_SAME)
194 		num_blocks = get_unaligned_be16(&cmd->t_task_cdb[7]);
195 	else if (cmd->t_task_cdb[0] == WRITE_SAME_16)
196 		num_blocks = get_unaligned_be32(&cmd->t_task_cdb[10]);
197 	else /* WRITE_SAME_32 via VARIABLE_LENGTH_CMD */
198 		num_blocks = get_unaligned_be32(&cmd->t_task_cdb[28]);
199 
200 	/*
201 	 * Use the explicit range when non zero is supplied, otherwise calculate
202 	 * the remaining range based on ->get_blocks() - starting LBA.
203 	 */
204 	if (num_blocks)
205 		return num_blocks;
206 
207 	return cmd->se_dev->transport->get_blocks(cmd->se_dev) -
208 		cmd->t_task_lba + 1;
209 }
210 EXPORT_SYMBOL(sbc_get_write_same_sectors);
211 
212 static sense_reason_t
213 sbc_execute_write_same_unmap(struct se_cmd *cmd)
214 {
215 	struct sbc_ops *ops = cmd->protocol_data;
216 	sector_t nolb = sbc_get_write_same_sectors(cmd);
217 	sense_reason_t ret;
218 
219 	if (nolb) {
220 		ret = ops->execute_unmap(cmd, cmd->t_task_lba, nolb);
221 		if (ret)
222 			return ret;
223 	}
224 
225 	target_complete_cmd(cmd, GOOD);
226 	return 0;
227 }
228 
229 static sense_reason_t
230 sbc_emulate_noop(struct se_cmd *cmd)
231 {
232 	target_complete_cmd(cmd, GOOD);
233 	return 0;
234 }
235 
236 static inline u32 sbc_get_size(struct se_cmd *cmd, u32 sectors)
237 {
238 	return cmd->se_dev->dev_attrib.block_size * sectors;
239 }
240 
241 static inline u32 transport_get_sectors_6(unsigned char *cdb)
242 {
243 	/*
244 	 * Use 8-bit sector value.  SBC-3 says:
245 	 *
246 	 *   A TRANSFER LENGTH field set to zero specifies that 256
247 	 *   logical blocks shall be written.  Any other value
248 	 *   specifies the number of logical blocks that shall be
249 	 *   written.
250 	 */
251 	return cdb[4] ? : 256;
252 }
253 
254 static inline u32 transport_get_sectors_10(unsigned char *cdb)
255 {
256 	return (u32)(cdb[7] << 8) + cdb[8];
257 }
258 
259 static inline u32 transport_get_sectors_12(unsigned char *cdb)
260 {
261 	return (u32)(cdb[6] << 24) + (cdb[7] << 16) + (cdb[8] << 8) + cdb[9];
262 }
263 
264 static inline u32 transport_get_sectors_16(unsigned char *cdb)
265 {
266 	return (u32)(cdb[10] << 24) + (cdb[11] << 16) +
267 		    (cdb[12] << 8) + cdb[13];
268 }
269 
270 /*
271  * Used for VARIABLE_LENGTH_CDB WRITE_32 and READ_32 variants
272  */
273 static inline u32 transport_get_sectors_32(unsigned char *cdb)
274 {
275 	return (u32)(cdb[28] << 24) + (cdb[29] << 16) +
276 		    (cdb[30] << 8) + cdb[31];
277 
278 }
279 
280 static inline u32 transport_lba_21(unsigned char *cdb)
281 {
282 	return ((cdb[1] & 0x1f) << 16) | (cdb[2] << 8) | cdb[3];
283 }
284 
285 static inline u32 transport_lba_32(unsigned char *cdb)
286 {
287 	return (cdb[2] << 24) | (cdb[3] << 16) | (cdb[4] << 8) | cdb[5];
288 }
289 
290 static inline unsigned long long transport_lba_64(unsigned char *cdb)
291 {
292 	unsigned int __v1, __v2;
293 
294 	__v1 = (cdb[2] << 24) | (cdb[3] << 16) | (cdb[4] << 8) | cdb[5];
295 	__v2 = (cdb[6] << 24) | (cdb[7] << 16) | (cdb[8] << 8) | cdb[9];
296 
297 	return ((unsigned long long)__v2) | (unsigned long long)__v1 << 32;
298 }
299 
300 /*
301  * For VARIABLE_LENGTH_CDB w/ 32 byte extended CDBs
302  */
303 static inline unsigned long long transport_lba_64_ext(unsigned char *cdb)
304 {
305 	unsigned int __v1, __v2;
306 
307 	__v1 = (cdb[12] << 24) | (cdb[13] << 16) | (cdb[14] << 8) | cdb[15];
308 	__v2 = (cdb[16] << 24) | (cdb[17] << 16) | (cdb[18] << 8) | cdb[19];
309 
310 	return ((unsigned long long)__v2) | (unsigned long long)__v1 << 32;
311 }
312 
313 static sense_reason_t
314 sbc_setup_write_same(struct se_cmd *cmd, unsigned char *flags, struct sbc_ops *ops)
315 {
316 	struct se_device *dev = cmd->se_dev;
317 	sector_t end_lba = dev->transport->get_blocks(dev) + 1;
318 	unsigned int sectors = sbc_get_write_same_sectors(cmd);
319 	sense_reason_t ret;
320 
321 	if ((flags[0] & 0x04) || (flags[0] & 0x02)) {
322 		pr_err("WRITE_SAME PBDATA and LBDATA"
323 			" bits not supported for Block Discard"
324 			" Emulation\n");
325 		return TCM_UNSUPPORTED_SCSI_OPCODE;
326 	}
327 	if (sectors > cmd->se_dev->dev_attrib.max_write_same_len) {
328 		pr_warn("WRITE_SAME sectors: %u exceeds max_write_same_len: %u\n",
329 			sectors, cmd->se_dev->dev_attrib.max_write_same_len);
330 		return TCM_INVALID_CDB_FIELD;
331 	}
332 	/*
333 	 * Sanity check for LBA wrap and request past end of device.
334 	 */
335 	if (((cmd->t_task_lba + sectors) < cmd->t_task_lba) ||
336 	    ((cmd->t_task_lba + sectors) > end_lba)) {
337 		pr_err("WRITE_SAME exceeds last lba %llu (lba %llu, sectors %u)\n",
338 		       (unsigned long long)end_lba, cmd->t_task_lba, sectors);
339 		return TCM_ADDRESS_OUT_OF_RANGE;
340 	}
341 
342 	/* We always have ANC_SUP == 0 so setting ANCHOR is always an error */
343 	if (flags[0] & 0x10) {
344 		pr_warn("WRITE SAME with ANCHOR not supported\n");
345 		return TCM_INVALID_CDB_FIELD;
346 	}
347 	/*
348 	 * Special case for WRITE_SAME w/ UNMAP=1 that ends up getting
349 	 * translated into block discard requests within backend code.
350 	 */
351 	if (flags[0] & 0x08) {
352 		if (!ops->execute_unmap)
353 			return TCM_UNSUPPORTED_SCSI_OPCODE;
354 
355 		if (!dev->dev_attrib.emulate_tpws) {
356 			pr_err("Got WRITE_SAME w/ UNMAP=1, but backend device"
357 			       " has emulate_tpws disabled\n");
358 			return TCM_UNSUPPORTED_SCSI_OPCODE;
359 		}
360 		cmd->execute_cmd = sbc_execute_write_same_unmap;
361 		return 0;
362 	}
363 	if (!ops->execute_write_same)
364 		return TCM_UNSUPPORTED_SCSI_OPCODE;
365 
366 	ret = sbc_check_prot(dev, cmd, &cmd->t_task_cdb[0], sectors, true);
367 	if (ret)
368 		return ret;
369 
370 	cmd->execute_cmd = ops->execute_write_same;
371 	return 0;
372 }
373 
374 static sense_reason_t xdreadwrite_callback(struct se_cmd *cmd, bool success)
375 {
376 	unsigned char *buf, *addr;
377 	struct scatterlist *sg;
378 	unsigned int offset;
379 	sense_reason_t ret = TCM_NO_SENSE;
380 	int i, count;
381 	/*
382 	 * From sbc3r22.pdf section 5.48 XDWRITEREAD (10) command
383 	 *
384 	 * 1) read the specified logical block(s);
385 	 * 2) transfer logical blocks from the data-out buffer;
386 	 * 3) XOR the logical blocks transferred from the data-out buffer with
387 	 *    the logical blocks read, storing the resulting XOR data in a buffer;
388 	 * 4) if the DISABLE WRITE bit is set to zero, then write the logical
389 	 *    blocks transferred from the data-out buffer; and
390 	 * 5) transfer the resulting XOR data to the data-in buffer.
391 	 */
392 	buf = kmalloc(cmd->data_length, GFP_KERNEL);
393 	if (!buf) {
394 		pr_err("Unable to allocate xor_callback buf\n");
395 		return TCM_OUT_OF_RESOURCES;
396 	}
397 	/*
398 	 * Copy the scatterlist WRITE buffer located at cmd->t_data_sg
399 	 * into the locally allocated *buf
400 	 */
401 	sg_copy_to_buffer(cmd->t_data_sg,
402 			  cmd->t_data_nents,
403 			  buf,
404 			  cmd->data_length);
405 
406 	/*
407 	 * Now perform the XOR against the BIDI read memory located at
408 	 * cmd->t_mem_bidi_list
409 	 */
410 
411 	offset = 0;
412 	for_each_sg(cmd->t_bidi_data_sg, sg, cmd->t_bidi_data_nents, count) {
413 		addr = kmap_atomic(sg_page(sg));
414 		if (!addr) {
415 			ret = TCM_OUT_OF_RESOURCES;
416 			goto out;
417 		}
418 
419 		for (i = 0; i < sg->length; i++)
420 			*(addr + sg->offset + i) ^= *(buf + offset + i);
421 
422 		offset += sg->length;
423 		kunmap_atomic(addr);
424 	}
425 
426 out:
427 	kfree(buf);
428 	return ret;
429 }
430 
431 static sense_reason_t
432 sbc_execute_rw(struct se_cmd *cmd)
433 {
434 	struct sbc_ops *ops = cmd->protocol_data;
435 
436 	return ops->execute_rw(cmd, cmd->t_data_sg, cmd->t_data_nents,
437 			       cmd->data_direction);
438 }
439 
440 static sense_reason_t compare_and_write_post(struct se_cmd *cmd, bool success)
441 {
442 	struct se_device *dev = cmd->se_dev;
443 
444 	/*
445 	 * Only set SCF_COMPARE_AND_WRITE_POST to force a response fall-through
446 	 * within target_complete_ok_work() if the command was successfully
447 	 * sent to the backend driver.
448 	 */
449 	spin_lock_irq(&cmd->t_state_lock);
450 	if ((cmd->transport_state & CMD_T_SENT) && !cmd->scsi_status)
451 		cmd->se_cmd_flags |= SCF_COMPARE_AND_WRITE_POST;
452 	spin_unlock_irq(&cmd->t_state_lock);
453 
454 	/*
455 	 * Unlock ->caw_sem originally obtained during sbc_compare_and_write()
456 	 * before the original READ I/O submission.
457 	 */
458 	up(&dev->caw_sem);
459 
460 	return TCM_NO_SENSE;
461 }
462 
463 static sense_reason_t compare_and_write_callback(struct se_cmd *cmd, bool success)
464 {
465 	struct se_device *dev = cmd->se_dev;
466 	struct scatterlist *write_sg = NULL, *sg;
467 	unsigned char *buf = NULL, *addr;
468 	struct sg_mapping_iter m;
469 	unsigned int offset = 0, len;
470 	unsigned int nlbas = cmd->t_task_nolb;
471 	unsigned int block_size = dev->dev_attrib.block_size;
472 	unsigned int compare_len = (nlbas * block_size);
473 	sense_reason_t ret = TCM_NO_SENSE;
474 	int rc, i;
475 
476 	/*
477 	 * Handle early failure in transport_generic_request_failure(),
478 	 * which will not have taken ->caw_sem yet..
479 	 */
480 	if (!success && (!cmd->t_data_sg || !cmd->t_bidi_data_sg))
481 		return TCM_NO_SENSE;
482 	/*
483 	 * Handle special case for zero-length COMPARE_AND_WRITE
484 	 */
485 	if (!cmd->data_length)
486 		goto out;
487 	/*
488 	 * Immediately exit + release dev->caw_sem if command has already
489 	 * been failed with a non-zero SCSI status.
490 	 */
491 	if (cmd->scsi_status) {
492 		pr_err("compare_and_write_callback: non zero scsi_status:"
493 			" 0x%02x\n", cmd->scsi_status);
494 		goto out;
495 	}
496 
497 	buf = kzalloc(cmd->data_length, GFP_KERNEL);
498 	if (!buf) {
499 		pr_err("Unable to allocate compare_and_write buf\n");
500 		ret = TCM_OUT_OF_RESOURCES;
501 		goto out;
502 	}
503 
504 	write_sg = kmalloc(sizeof(struct scatterlist) * cmd->t_data_nents,
505 			   GFP_KERNEL);
506 	if (!write_sg) {
507 		pr_err("Unable to allocate compare_and_write sg\n");
508 		ret = TCM_OUT_OF_RESOURCES;
509 		goto out;
510 	}
511 	sg_init_table(write_sg, cmd->t_data_nents);
512 	/*
513 	 * Setup verify and write data payloads from total NumberLBAs.
514 	 */
515 	rc = sg_copy_to_buffer(cmd->t_data_sg, cmd->t_data_nents, buf,
516 			       cmd->data_length);
517 	if (!rc) {
518 		pr_err("sg_copy_to_buffer() failed for compare_and_write\n");
519 		ret = TCM_OUT_OF_RESOURCES;
520 		goto out;
521 	}
522 	/*
523 	 * Compare against SCSI READ payload against verify payload
524 	 */
525 	for_each_sg(cmd->t_bidi_data_sg, sg, cmd->t_bidi_data_nents, i) {
526 		addr = (unsigned char *)kmap_atomic(sg_page(sg));
527 		if (!addr) {
528 			ret = TCM_OUT_OF_RESOURCES;
529 			goto out;
530 		}
531 
532 		len = min(sg->length, compare_len);
533 
534 		if (memcmp(addr, buf + offset, len)) {
535 			pr_warn("Detected MISCOMPARE for addr: %p buf: %p\n",
536 				addr, buf + offset);
537 			kunmap_atomic(addr);
538 			goto miscompare;
539 		}
540 		kunmap_atomic(addr);
541 
542 		offset += len;
543 		compare_len -= len;
544 		if (!compare_len)
545 			break;
546 	}
547 
548 	i = 0;
549 	len = cmd->t_task_nolb * block_size;
550 	sg_miter_start(&m, cmd->t_data_sg, cmd->t_data_nents, SG_MITER_TO_SG);
551 	/*
552 	 * Currently assumes NoLB=1 and SGLs are PAGE_SIZE..
553 	 */
554 	while (len) {
555 		sg_miter_next(&m);
556 
557 		if (block_size < PAGE_SIZE) {
558 			sg_set_page(&write_sg[i], m.page, block_size,
559 				    block_size);
560 		} else {
561 			sg_miter_next(&m);
562 			sg_set_page(&write_sg[i], m.page, block_size,
563 				    0);
564 		}
565 		len -= block_size;
566 		i++;
567 	}
568 	sg_miter_stop(&m);
569 	/*
570 	 * Save the original SGL + nents values before updating to new
571 	 * assignments, to be released in transport_free_pages() ->
572 	 * transport_reset_sgl_orig()
573 	 */
574 	cmd->t_data_sg_orig = cmd->t_data_sg;
575 	cmd->t_data_sg = write_sg;
576 	cmd->t_data_nents_orig = cmd->t_data_nents;
577 	cmd->t_data_nents = 1;
578 
579 	cmd->sam_task_attr = TCM_HEAD_TAG;
580 	cmd->transport_complete_callback = compare_and_write_post;
581 	/*
582 	 * Now reset ->execute_cmd() to the normal sbc_execute_rw() handler
583 	 * for submitting the adjusted SGL to write instance user-data.
584 	 */
585 	cmd->execute_cmd = sbc_execute_rw;
586 
587 	spin_lock_irq(&cmd->t_state_lock);
588 	cmd->t_state = TRANSPORT_PROCESSING;
589 	cmd->transport_state |= CMD_T_ACTIVE|CMD_T_BUSY|CMD_T_SENT;
590 	spin_unlock_irq(&cmd->t_state_lock);
591 
592 	__target_execute_cmd(cmd);
593 
594 	kfree(buf);
595 	return ret;
596 
597 miscompare:
598 	pr_warn("Target/%s: Send MISCOMPARE check condition and sense\n",
599 		dev->transport->name);
600 	ret = TCM_MISCOMPARE_VERIFY;
601 out:
602 	/*
603 	 * In the MISCOMPARE or failure case, unlock ->caw_sem obtained in
604 	 * sbc_compare_and_write() before the original READ I/O submission.
605 	 */
606 	up(&dev->caw_sem);
607 	kfree(write_sg);
608 	kfree(buf);
609 	return ret;
610 }
611 
612 static sense_reason_t
613 sbc_compare_and_write(struct se_cmd *cmd)
614 {
615 	struct sbc_ops *ops = cmd->protocol_data;
616 	struct se_device *dev = cmd->se_dev;
617 	sense_reason_t ret;
618 	int rc;
619 	/*
620 	 * Submit the READ first for COMPARE_AND_WRITE to perform the
621 	 * comparision using SGLs at cmd->t_bidi_data_sg..
622 	 */
623 	rc = down_interruptible(&dev->caw_sem);
624 	if (rc != 0) {
625 		cmd->transport_complete_callback = NULL;
626 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
627 	}
628 	/*
629 	 * Reset cmd->data_length to individual block_size in order to not
630 	 * confuse backend drivers that depend on this value matching the
631 	 * size of the I/O being submitted.
632 	 */
633 	cmd->data_length = cmd->t_task_nolb * dev->dev_attrib.block_size;
634 
635 	ret = ops->execute_rw(cmd, cmd->t_bidi_data_sg, cmd->t_bidi_data_nents,
636 			      DMA_FROM_DEVICE);
637 	if (ret) {
638 		cmd->transport_complete_callback = NULL;
639 		up(&dev->caw_sem);
640 		return ret;
641 	}
642 	/*
643 	 * Unlock of dev->caw_sem to occur in compare_and_write_callback()
644 	 * upon MISCOMPARE, or in compare_and_write_done() upon completion
645 	 * of WRITE instance user-data.
646 	 */
647 	return TCM_NO_SENSE;
648 }
649 
650 static int
651 sbc_set_prot_op_checks(u8 protect, bool fabric_prot, enum target_prot_type prot_type,
652 		       bool is_write, struct se_cmd *cmd)
653 {
654 	if (is_write) {
655 		cmd->prot_op = fabric_prot ? TARGET_PROT_DOUT_STRIP :
656 			       protect ? TARGET_PROT_DOUT_PASS :
657 			       TARGET_PROT_DOUT_INSERT;
658 		switch (protect) {
659 		case 0x0:
660 		case 0x3:
661 			cmd->prot_checks = 0;
662 			break;
663 		case 0x1:
664 		case 0x5:
665 			cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
666 			if (prot_type == TARGET_DIF_TYPE1_PROT)
667 				cmd->prot_checks |= TARGET_DIF_CHECK_REFTAG;
668 			break;
669 		case 0x2:
670 			if (prot_type == TARGET_DIF_TYPE1_PROT)
671 				cmd->prot_checks = TARGET_DIF_CHECK_REFTAG;
672 			break;
673 		case 0x4:
674 			cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
675 			break;
676 		default:
677 			pr_err("Unsupported protect field %d\n", protect);
678 			return -EINVAL;
679 		}
680 	} else {
681 		cmd->prot_op = fabric_prot ? TARGET_PROT_DIN_INSERT :
682 			       protect ? TARGET_PROT_DIN_PASS :
683 			       TARGET_PROT_DIN_STRIP;
684 		switch (protect) {
685 		case 0x0:
686 		case 0x1:
687 		case 0x5:
688 			cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
689 			if (prot_type == TARGET_DIF_TYPE1_PROT)
690 				cmd->prot_checks |= TARGET_DIF_CHECK_REFTAG;
691 			break;
692 		case 0x2:
693 			if (prot_type == TARGET_DIF_TYPE1_PROT)
694 				cmd->prot_checks = TARGET_DIF_CHECK_REFTAG;
695 			break;
696 		case 0x3:
697 			cmd->prot_checks = 0;
698 			break;
699 		case 0x4:
700 			cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
701 			break;
702 		default:
703 			pr_err("Unsupported protect field %d\n", protect);
704 			return -EINVAL;
705 		}
706 	}
707 
708 	return 0;
709 }
710 
711 static sense_reason_t
712 sbc_check_prot(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb,
713 	       u32 sectors, bool is_write)
714 {
715 	u8 protect = cdb[1] >> 5;
716 	int sp_ops = cmd->se_sess->sup_prot_ops;
717 	int pi_prot_type = dev->dev_attrib.pi_prot_type;
718 	bool fabric_prot = false;
719 
720 	if (!cmd->t_prot_sg || !cmd->t_prot_nents) {
721 		if (unlikely(protect &&
722 		    !dev->dev_attrib.pi_prot_type && !cmd->se_sess->sess_prot_type)) {
723 			pr_err("CDB contains protect bit, but device + fabric does"
724 			       " not advertise PROTECT=1 feature bit\n");
725 			return TCM_INVALID_CDB_FIELD;
726 		}
727 		if (cmd->prot_pto)
728 			return TCM_NO_SENSE;
729 	}
730 
731 	switch (dev->dev_attrib.pi_prot_type) {
732 	case TARGET_DIF_TYPE3_PROT:
733 		cmd->reftag_seed = 0xffffffff;
734 		break;
735 	case TARGET_DIF_TYPE2_PROT:
736 		if (protect)
737 			return TCM_INVALID_CDB_FIELD;
738 
739 		cmd->reftag_seed = cmd->t_task_lba;
740 		break;
741 	case TARGET_DIF_TYPE1_PROT:
742 		cmd->reftag_seed = cmd->t_task_lba;
743 		break;
744 	case TARGET_DIF_TYPE0_PROT:
745 		/*
746 		 * See if the fabric supports T10-PI, and the session has been
747 		 * configured to allow export PROTECT=1 feature bit with backend
748 		 * devices that don't support T10-PI.
749 		 */
750 		fabric_prot = is_write ?
751 			      !!(sp_ops & (TARGET_PROT_DOUT_PASS | TARGET_PROT_DOUT_STRIP)) :
752 			      !!(sp_ops & (TARGET_PROT_DIN_PASS | TARGET_PROT_DIN_INSERT));
753 
754 		if (fabric_prot && cmd->se_sess->sess_prot_type) {
755 			pi_prot_type = cmd->se_sess->sess_prot_type;
756 			break;
757 		}
758 		if (!protect)
759 			return TCM_NO_SENSE;
760 		/* Fallthrough */
761 	default:
762 		pr_err("Unable to determine pi_prot_type for CDB: 0x%02x "
763 		       "PROTECT: 0x%02x\n", cdb[0], protect);
764 		return TCM_INVALID_CDB_FIELD;
765 	}
766 
767 	if (sbc_set_prot_op_checks(protect, fabric_prot, pi_prot_type, is_write, cmd))
768 		return TCM_INVALID_CDB_FIELD;
769 
770 	cmd->prot_type = pi_prot_type;
771 	cmd->prot_length = dev->prot_length * sectors;
772 
773 	/**
774 	 * In case protection information exists over the wire
775 	 * we modify command data length to describe pure data.
776 	 * The actual transfer length is data length + protection
777 	 * length
778 	 **/
779 	if (protect)
780 		cmd->data_length = sectors * dev->dev_attrib.block_size;
781 
782 	pr_debug("%s: prot_type=%d, data_length=%d, prot_length=%d "
783 		 "prot_op=%d prot_checks=%d\n",
784 		 __func__, cmd->prot_type, cmd->data_length, cmd->prot_length,
785 		 cmd->prot_op, cmd->prot_checks);
786 
787 	return TCM_NO_SENSE;
788 }
789 
790 static int
791 sbc_check_dpofua(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb)
792 {
793 	if (cdb[1] & 0x10) {
794 		/* see explanation in spc_emulate_modesense */
795 		if (!target_check_fua(dev)) {
796 			pr_err("Got CDB: 0x%02x with DPO bit set, but device"
797 			       " does not advertise support for DPO\n", cdb[0]);
798 			return -EINVAL;
799 		}
800 	}
801 	if (cdb[1] & 0x8) {
802 		if (!target_check_fua(dev)) {
803 			pr_err("Got CDB: 0x%02x with FUA bit set, but device"
804 			       " does not advertise support for FUA write\n",
805 			       cdb[0]);
806 			return -EINVAL;
807 		}
808 		cmd->se_cmd_flags |= SCF_FUA;
809 	}
810 	return 0;
811 }
812 
813 sense_reason_t
814 sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
815 {
816 	struct se_device *dev = cmd->se_dev;
817 	unsigned char *cdb = cmd->t_task_cdb;
818 	unsigned int size;
819 	u32 sectors = 0;
820 	sense_reason_t ret;
821 
822 	cmd->protocol_data = ops;
823 
824 	switch (cdb[0]) {
825 	case READ_6:
826 		sectors = transport_get_sectors_6(cdb);
827 		cmd->t_task_lba = transport_lba_21(cdb);
828 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
829 		cmd->execute_cmd = sbc_execute_rw;
830 		break;
831 	case READ_10:
832 		sectors = transport_get_sectors_10(cdb);
833 		cmd->t_task_lba = transport_lba_32(cdb);
834 
835 		if (sbc_check_dpofua(dev, cmd, cdb))
836 			return TCM_INVALID_CDB_FIELD;
837 
838 		ret = sbc_check_prot(dev, cmd, cdb, sectors, false);
839 		if (ret)
840 			return ret;
841 
842 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
843 		cmd->execute_cmd = sbc_execute_rw;
844 		break;
845 	case READ_12:
846 		sectors = transport_get_sectors_12(cdb);
847 		cmd->t_task_lba = transport_lba_32(cdb);
848 
849 		if (sbc_check_dpofua(dev, cmd, cdb))
850 			return TCM_INVALID_CDB_FIELD;
851 
852 		ret = sbc_check_prot(dev, cmd, cdb, sectors, false);
853 		if (ret)
854 			return ret;
855 
856 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
857 		cmd->execute_cmd = sbc_execute_rw;
858 		break;
859 	case READ_16:
860 		sectors = transport_get_sectors_16(cdb);
861 		cmd->t_task_lba = transport_lba_64(cdb);
862 
863 		if (sbc_check_dpofua(dev, cmd, cdb))
864 			return TCM_INVALID_CDB_FIELD;
865 
866 		ret = sbc_check_prot(dev, cmd, cdb, sectors, false);
867 		if (ret)
868 			return ret;
869 
870 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
871 		cmd->execute_cmd = sbc_execute_rw;
872 		break;
873 	case WRITE_6:
874 		sectors = transport_get_sectors_6(cdb);
875 		cmd->t_task_lba = transport_lba_21(cdb);
876 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
877 		cmd->execute_cmd = sbc_execute_rw;
878 		break;
879 	case WRITE_10:
880 	case WRITE_VERIFY:
881 		sectors = transport_get_sectors_10(cdb);
882 		cmd->t_task_lba = transport_lba_32(cdb);
883 
884 		if (sbc_check_dpofua(dev, cmd, cdb))
885 			return TCM_INVALID_CDB_FIELD;
886 
887 		ret = sbc_check_prot(dev, cmd, cdb, sectors, true);
888 		if (ret)
889 			return ret;
890 
891 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
892 		cmd->execute_cmd = sbc_execute_rw;
893 		break;
894 	case WRITE_12:
895 		sectors = transport_get_sectors_12(cdb);
896 		cmd->t_task_lba = transport_lba_32(cdb);
897 
898 		if (sbc_check_dpofua(dev, cmd, cdb))
899 			return TCM_INVALID_CDB_FIELD;
900 
901 		ret = sbc_check_prot(dev, cmd, cdb, sectors, true);
902 		if (ret)
903 			return ret;
904 
905 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
906 		cmd->execute_cmd = sbc_execute_rw;
907 		break;
908 	case WRITE_16:
909 		sectors = transport_get_sectors_16(cdb);
910 		cmd->t_task_lba = transport_lba_64(cdb);
911 
912 		if (sbc_check_dpofua(dev, cmd, cdb))
913 			return TCM_INVALID_CDB_FIELD;
914 
915 		ret = sbc_check_prot(dev, cmd, cdb, sectors, true);
916 		if (ret)
917 			return ret;
918 
919 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
920 		cmd->execute_cmd = sbc_execute_rw;
921 		break;
922 	case XDWRITEREAD_10:
923 		if (cmd->data_direction != DMA_TO_DEVICE ||
924 		    !(cmd->se_cmd_flags & SCF_BIDI))
925 			return TCM_INVALID_CDB_FIELD;
926 		sectors = transport_get_sectors_10(cdb);
927 
928 		if (sbc_check_dpofua(dev, cmd, cdb))
929 			return TCM_INVALID_CDB_FIELD;
930 
931 		cmd->t_task_lba = transport_lba_32(cdb);
932 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
933 
934 		/*
935 		 * Setup BIDI XOR callback to be run after I/O completion.
936 		 */
937 		cmd->execute_cmd = sbc_execute_rw;
938 		cmd->transport_complete_callback = &xdreadwrite_callback;
939 		break;
940 	case VARIABLE_LENGTH_CMD:
941 	{
942 		u16 service_action = get_unaligned_be16(&cdb[8]);
943 		switch (service_action) {
944 		case XDWRITEREAD_32:
945 			sectors = transport_get_sectors_32(cdb);
946 
947 			if (sbc_check_dpofua(dev, cmd, cdb))
948 				return TCM_INVALID_CDB_FIELD;
949 			/*
950 			 * Use WRITE_32 and READ_32 opcodes for the emulated
951 			 * XDWRITE_READ_32 logic.
952 			 */
953 			cmd->t_task_lba = transport_lba_64_ext(cdb);
954 			cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
955 
956 			/*
957 			 * Setup BIDI XOR callback to be run during after I/O
958 			 * completion.
959 			 */
960 			cmd->execute_cmd = sbc_execute_rw;
961 			cmd->transport_complete_callback = &xdreadwrite_callback;
962 			break;
963 		case WRITE_SAME_32:
964 			sectors = transport_get_sectors_32(cdb);
965 			if (!sectors) {
966 				pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not"
967 				       " supported\n");
968 				return TCM_INVALID_CDB_FIELD;
969 			}
970 
971 			size = sbc_get_size(cmd, 1);
972 			cmd->t_task_lba = get_unaligned_be64(&cdb[12]);
973 
974 			ret = sbc_setup_write_same(cmd, &cdb[10], ops);
975 			if (ret)
976 				return ret;
977 			break;
978 		default:
979 			pr_err("VARIABLE_LENGTH_CMD service action"
980 				" 0x%04x not supported\n", service_action);
981 			return TCM_UNSUPPORTED_SCSI_OPCODE;
982 		}
983 		break;
984 	}
985 	case COMPARE_AND_WRITE:
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 = (cdb[10] << 24) | (cdb[11] << 16) |
1027 		       (cdb[12] << 8) | cdb[13];
1028 		break;
1029 	case SYNCHRONIZE_CACHE:
1030 	case SYNCHRONIZE_CACHE_16:
1031 		if (cdb[0] == SYNCHRONIZE_CACHE) {
1032 			sectors = transport_get_sectors_10(cdb);
1033 			cmd->t_task_lba = transport_lba_32(cdb);
1034 		} else {
1035 			sectors = transport_get_sectors_16(cdb);
1036 			cmd->t_task_lba = transport_lba_64(cdb);
1037 		}
1038 		if (ops->execute_sync_cache) {
1039 			cmd->execute_cmd = ops->execute_sync_cache;
1040 			goto check_lba;
1041 		}
1042 		size = 0;
1043 		cmd->execute_cmd = sbc_emulate_noop;
1044 		break;
1045 	case UNMAP:
1046 		if (!ops->execute_unmap)
1047 			return TCM_UNSUPPORTED_SCSI_OPCODE;
1048 
1049 		if (!dev->dev_attrib.emulate_tpu) {
1050 			pr_err("Got UNMAP, but backend device has"
1051 			       " emulate_tpu disabled\n");
1052 			return TCM_UNSUPPORTED_SCSI_OPCODE;
1053 		}
1054 		size = get_unaligned_be16(&cdb[7]);
1055 		cmd->execute_cmd = sbc_execute_unmap;
1056 		break;
1057 	case WRITE_SAME_16:
1058 		sectors = transport_get_sectors_16(cdb);
1059 		if (!sectors) {
1060 			pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
1061 			return TCM_INVALID_CDB_FIELD;
1062 		}
1063 
1064 		size = sbc_get_size(cmd, 1);
1065 		cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
1066 
1067 		ret = sbc_setup_write_same(cmd, &cdb[1], ops);
1068 		if (ret)
1069 			return ret;
1070 		break;
1071 	case WRITE_SAME:
1072 		sectors = transport_get_sectors_10(cdb);
1073 		if (!sectors) {
1074 			pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
1075 			return TCM_INVALID_CDB_FIELD;
1076 		}
1077 
1078 		size = sbc_get_size(cmd, 1);
1079 		cmd->t_task_lba = get_unaligned_be32(&cdb[2]);
1080 
1081 		/*
1082 		 * Follow sbcr26 with WRITE_SAME (10) and check for the existence
1083 		 * of byte 1 bit 3 UNMAP instead of original reserved field
1084 		 */
1085 		ret = sbc_setup_write_same(cmd, &cdb[1], ops);
1086 		if (ret)
1087 			return ret;
1088 		break;
1089 	case VERIFY:
1090 		size = 0;
1091 		sectors = transport_get_sectors_10(cdb);
1092 		cmd->t_task_lba = transport_lba_32(cdb);
1093 		cmd->execute_cmd = sbc_emulate_noop;
1094 		goto check_lba;
1095 	case REZERO_UNIT:
1096 	case SEEK_6:
1097 	case SEEK_10:
1098 		/*
1099 		 * There are still clients out there which use these old SCSI-2
1100 		 * commands. This mainly happens when running VMs with legacy
1101 		 * guest systems, connected via SCSI command pass-through to
1102 		 * iSCSI targets. Make them happy and return status GOOD.
1103 		 */
1104 		size = 0;
1105 		cmd->execute_cmd = sbc_emulate_noop;
1106 		break;
1107 	case START_STOP:
1108 		size = 0;
1109 		cmd->execute_cmd = sbc_emulate_startstop;
1110 		break;
1111 	default:
1112 		ret = spc_parse_cdb(cmd, &size);
1113 		if (ret)
1114 			return ret;
1115 	}
1116 
1117 	/* reject any command that we don't have a handler for */
1118 	if (!cmd->execute_cmd)
1119 		return TCM_UNSUPPORTED_SCSI_OPCODE;
1120 
1121 	if (cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
1122 		unsigned long long end_lba;
1123 check_lba:
1124 		end_lba = dev->transport->get_blocks(dev) + 1;
1125 		if (((cmd->t_task_lba + sectors) < cmd->t_task_lba) ||
1126 		    ((cmd->t_task_lba + sectors) > end_lba)) {
1127 			pr_err("cmd exceeds last lba %llu "
1128 				"(lba %llu, sectors %u)\n",
1129 				end_lba, cmd->t_task_lba, sectors);
1130 			return TCM_ADDRESS_OUT_OF_RANGE;
1131 		}
1132 
1133 		if (!(cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE))
1134 			size = sbc_get_size(cmd, sectors);
1135 	}
1136 
1137 	return target_cmd_size_check(cmd, size);
1138 }
1139 EXPORT_SYMBOL(sbc_parse_cdb);
1140 
1141 u32 sbc_get_device_type(struct se_device *dev)
1142 {
1143 	return TYPE_DISK;
1144 }
1145 EXPORT_SYMBOL(sbc_get_device_type);
1146 
1147 static sense_reason_t
1148 sbc_execute_unmap(struct se_cmd *cmd)
1149 {
1150 	struct sbc_ops *ops = cmd->protocol_data;
1151 	struct se_device *dev = cmd->se_dev;
1152 	unsigned char *buf, *ptr = NULL;
1153 	sector_t lba;
1154 	int size;
1155 	u32 range;
1156 	sense_reason_t ret = 0;
1157 	int dl, bd_dl;
1158 
1159 	/* We never set ANC_SUP */
1160 	if (cmd->t_task_cdb[1])
1161 		return TCM_INVALID_CDB_FIELD;
1162 
1163 	if (cmd->data_length == 0) {
1164 		target_complete_cmd(cmd, SAM_STAT_GOOD);
1165 		return 0;
1166 	}
1167 
1168 	if (cmd->data_length < 8) {
1169 		pr_warn("UNMAP parameter list length %u too small\n",
1170 			cmd->data_length);
1171 		return TCM_PARAMETER_LIST_LENGTH_ERROR;
1172 	}
1173 
1174 	buf = transport_kmap_data_sg(cmd);
1175 	if (!buf)
1176 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1177 
1178 	dl = get_unaligned_be16(&buf[0]);
1179 	bd_dl = get_unaligned_be16(&buf[2]);
1180 
1181 	size = cmd->data_length - 8;
1182 	if (bd_dl > size)
1183 		pr_warn("UNMAP parameter list length %u too small, ignoring bd_dl %u\n",
1184 			cmd->data_length, bd_dl);
1185 	else
1186 		size = bd_dl;
1187 
1188 	if (size / 16 > dev->dev_attrib.max_unmap_block_desc_count) {
1189 		ret = TCM_INVALID_PARAMETER_LIST;
1190 		goto err;
1191 	}
1192 
1193 	/* First UNMAP block descriptor starts at 8 byte offset */
1194 	ptr = &buf[8];
1195 	pr_debug("UNMAP: Sub: %s Using dl: %u bd_dl: %u size: %u"
1196 		" ptr: %p\n", dev->transport->name, dl, bd_dl, size, ptr);
1197 
1198 	while (size >= 16) {
1199 		lba = get_unaligned_be64(&ptr[0]);
1200 		range = get_unaligned_be32(&ptr[8]);
1201 		pr_debug("UNMAP: Using lba: %llu and range: %u\n",
1202 				 (unsigned long long)lba, range);
1203 
1204 		if (range > dev->dev_attrib.max_unmap_lba_count) {
1205 			ret = TCM_INVALID_PARAMETER_LIST;
1206 			goto err;
1207 		}
1208 
1209 		if (lba + range > dev->transport->get_blocks(dev) + 1) {
1210 			ret = TCM_ADDRESS_OUT_OF_RANGE;
1211 			goto err;
1212 		}
1213 
1214 		ret = ops->execute_unmap(cmd, lba, range);
1215 		if (ret)
1216 			goto err;
1217 
1218 		ptr += 16;
1219 		size -= 16;
1220 	}
1221 
1222 err:
1223 	transport_kunmap_data_sg(cmd);
1224 	if (!ret)
1225 		target_complete_cmd(cmd, GOOD);
1226 	return ret;
1227 }
1228 
1229 void
1230 sbc_dif_generate(struct se_cmd *cmd)
1231 {
1232 	struct se_device *dev = cmd->se_dev;
1233 	struct t10_pi_tuple *sdt;
1234 	struct scatterlist *dsg = cmd->t_data_sg, *psg;
1235 	sector_t sector = cmd->t_task_lba;
1236 	void *daddr, *paddr;
1237 	int i, j, offset = 0;
1238 	unsigned int block_size = dev->dev_attrib.block_size;
1239 
1240 	for_each_sg(cmd->t_prot_sg, psg, cmd->t_prot_nents, i) {
1241 		paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1242 		daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1243 
1244 		for (j = 0; j < psg->length;
1245 				j += sizeof(*sdt)) {
1246 			__u16 crc;
1247 			unsigned int avail;
1248 
1249 			if (offset >= dsg->length) {
1250 				offset -= dsg->length;
1251 				kunmap_atomic(daddr - dsg->offset);
1252 				dsg = sg_next(dsg);
1253 				if (!dsg) {
1254 					kunmap_atomic(paddr - psg->offset);
1255 					return;
1256 				}
1257 				daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1258 			}
1259 
1260 			sdt = paddr + j;
1261 			avail = min(block_size, dsg->length - offset);
1262 			crc = crc_t10dif(daddr + offset, avail);
1263 			if (avail < block_size) {
1264 				kunmap_atomic(daddr - dsg->offset);
1265 				dsg = sg_next(dsg);
1266 				if (!dsg) {
1267 					kunmap_atomic(paddr - psg->offset);
1268 					return;
1269 				}
1270 				daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1271 				offset = block_size - avail;
1272 				crc = crc_t10dif_update(crc, daddr, offset);
1273 			} else {
1274 				offset += block_size;
1275 			}
1276 
1277 			sdt->guard_tag = cpu_to_be16(crc);
1278 			if (cmd->prot_type == TARGET_DIF_TYPE1_PROT)
1279 				sdt->ref_tag = cpu_to_be32(sector & 0xffffffff);
1280 			sdt->app_tag = 0;
1281 
1282 			pr_debug("DIF %s INSERT sector: %llu guard_tag: 0x%04x"
1283 				 " app_tag: 0x%04x ref_tag: %u\n",
1284 				 (cmd->data_direction == DMA_TO_DEVICE) ?
1285 				 "WRITE" : "READ", (unsigned long long)sector,
1286 				 sdt->guard_tag, sdt->app_tag,
1287 				 be32_to_cpu(sdt->ref_tag));
1288 
1289 			sector++;
1290 		}
1291 
1292 		kunmap_atomic(daddr - dsg->offset);
1293 		kunmap_atomic(paddr - psg->offset);
1294 	}
1295 }
1296 
1297 static sense_reason_t
1298 sbc_dif_v1_verify(struct se_cmd *cmd, struct t10_pi_tuple *sdt,
1299 		  __u16 crc, sector_t sector, unsigned int ei_lba)
1300 {
1301 	__be16 csum;
1302 
1303 	if (!(cmd->prot_checks & TARGET_DIF_CHECK_GUARD))
1304 		goto check_ref;
1305 
1306 	csum = cpu_to_be16(crc);
1307 
1308 	if (sdt->guard_tag != csum) {
1309 		pr_err("DIFv1 checksum failed on sector %llu guard tag 0x%04x"
1310 			" csum 0x%04x\n", (unsigned long long)sector,
1311 			be16_to_cpu(sdt->guard_tag), be16_to_cpu(csum));
1312 		return TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED;
1313 	}
1314 
1315 check_ref:
1316 	if (!(cmd->prot_checks & TARGET_DIF_CHECK_REFTAG))
1317 		return 0;
1318 
1319 	if (cmd->prot_type == TARGET_DIF_TYPE1_PROT &&
1320 	    be32_to_cpu(sdt->ref_tag) != (sector & 0xffffffff)) {
1321 		pr_err("DIFv1 Type 1 reference failed on sector: %llu tag: 0x%08x"
1322 		       " sector MSB: 0x%08x\n", (unsigned long long)sector,
1323 		       be32_to_cpu(sdt->ref_tag), (u32)(sector & 0xffffffff));
1324 		return TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;
1325 	}
1326 
1327 	if (cmd->prot_type == TARGET_DIF_TYPE2_PROT &&
1328 	    be32_to_cpu(sdt->ref_tag) != ei_lba) {
1329 		pr_err("DIFv1 Type 2 reference failed on sector: %llu tag: 0x%08x"
1330 		       " ei_lba: 0x%08x\n", (unsigned long long)sector,
1331 			be32_to_cpu(sdt->ref_tag), ei_lba);
1332 		return TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;
1333 	}
1334 
1335 	return 0;
1336 }
1337 
1338 void sbc_dif_copy_prot(struct se_cmd *cmd, unsigned int sectors, bool read,
1339 		       struct scatterlist *sg, int sg_off)
1340 {
1341 	struct se_device *dev = cmd->se_dev;
1342 	struct scatterlist *psg;
1343 	void *paddr, *addr;
1344 	unsigned int i, len, left;
1345 	unsigned int offset = sg_off;
1346 
1347 	if (!sg)
1348 		return;
1349 
1350 	left = sectors * dev->prot_length;
1351 
1352 	for_each_sg(cmd->t_prot_sg, psg, cmd->t_prot_nents, i) {
1353 		unsigned int psg_len, copied = 0;
1354 
1355 		paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1356 		psg_len = min(left, psg->length);
1357 		while (psg_len) {
1358 			len = min(psg_len, sg->length - offset);
1359 			addr = kmap_atomic(sg_page(sg)) + sg->offset + offset;
1360 
1361 			if (read)
1362 				memcpy(paddr + copied, addr, len);
1363 			else
1364 				memcpy(addr, paddr + copied, len);
1365 
1366 			left -= len;
1367 			offset += len;
1368 			copied += len;
1369 			psg_len -= len;
1370 
1371 			kunmap_atomic(addr - sg->offset - offset);
1372 
1373 			if (offset >= sg->length) {
1374 				sg = sg_next(sg);
1375 				offset = 0;
1376 			}
1377 		}
1378 		kunmap_atomic(paddr - psg->offset);
1379 	}
1380 }
1381 EXPORT_SYMBOL(sbc_dif_copy_prot);
1382 
1383 sense_reason_t
1384 sbc_dif_verify(struct se_cmd *cmd, sector_t start, unsigned int sectors,
1385 	       unsigned int ei_lba, struct scatterlist *psg, int psg_off)
1386 {
1387 	struct se_device *dev = cmd->se_dev;
1388 	struct t10_pi_tuple *sdt;
1389 	struct scatterlist *dsg = cmd->t_data_sg;
1390 	sector_t sector = start;
1391 	void *daddr, *paddr;
1392 	int i;
1393 	sense_reason_t rc;
1394 	int dsg_off = 0;
1395 	unsigned int block_size = dev->dev_attrib.block_size;
1396 
1397 	for (; psg && sector < start + sectors; psg = sg_next(psg)) {
1398 		paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1399 		daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1400 
1401 		for (i = psg_off; i < psg->length &&
1402 				sector < start + sectors;
1403 				i += sizeof(*sdt)) {
1404 			__u16 crc;
1405 			unsigned int avail;
1406 
1407 			if (dsg_off >= dsg->length) {
1408 				dsg_off -= dsg->length;
1409 				kunmap_atomic(daddr - dsg->offset);
1410 				dsg = sg_next(dsg);
1411 				if (!dsg) {
1412 					kunmap_atomic(paddr - psg->offset);
1413 					return 0;
1414 				}
1415 				daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1416 			}
1417 
1418 			sdt = paddr + i;
1419 
1420 			pr_debug("DIF READ sector: %llu guard_tag: 0x%04x"
1421 				 " app_tag: 0x%04x ref_tag: %u\n",
1422 				 (unsigned long long)sector, sdt->guard_tag,
1423 				 sdt->app_tag, be32_to_cpu(sdt->ref_tag));
1424 
1425 			if (sdt->app_tag == cpu_to_be16(0xffff)) {
1426 				dsg_off += block_size;
1427 				goto next;
1428 			}
1429 
1430 			avail = min(block_size, dsg->length - dsg_off);
1431 			crc = crc_t10dif(daddr + dsg_off, avail);
1432 			if (avail < block_size) {
1433 				kunmap_atomic(daddr - dsg->offset);
1434 				dsg = sg_next(dsg);
1435 				if (!dsg) {
1436 					kunmap_atomic(paddr - psg->offset);
1437 					return 0;
1438 				}
1439 				daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1440 				dsg_off = block_size - avail;
1441 				crc = crc_t10dif_update(crc, daddr, dsg_off);
1442 			} else {
1443 				dsg_off += block_size;
1444 			}
1445 
1446 			rc = sbc_dif_v1_verify(cmd, sdt, crc, sector, ei_lba);
1447 			if (rc) {
1448 				kunmap_atomic(daddr - dsg->offset);
1449 				kunmap_atomic(paddr - psg->offset);
1450 				cmd->bad_sector = sector;
1451 				return rc;
1452 			}
1453 next:
1454 			sector++;
1455 			ei_lba++;
1456 		}
1457 
1458 		psg_off = 0;
1459 		kunmap_atomic(daddr - dsg->offset);
1460 		kunmap_atomic(paddr - psg->offset);
1461 	}
1462 
1463 	return 0;
1464 }
1465 EXPORT_SYMBOL(sbc_dif_verify);
1466