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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
sbc_emulate_readcapacity(struct se_cmd * cmd)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_with_length(cmd, GOOD, 8);
85 	return 0;
86 }
87 
88 static sense_reason_t
sbc_emulate_readcapacity_16(struct se_cmd * cmd)89 sbc_emulate_readcapacity_16(struct se_cmd *cmd)
90 {
91 	struct se_device *dev = cmd->se_dev;
92 	struct se_session *sess = cmd->se_sess;
93 	unsigned char *rbuf;
94 	unsigned char buf[32];
95 	unsigned long long blocks = dev->transport->get_blocks(dev);
96 
97 	memset(buf, 0, sizeof(buf));
98 	buf[0] = (blocks >> 56) & 0xff;
99 	buf[1] = (blocks >> 48) & 0xff;
100 	buf[2] = (blocks >> 40) & 0xff;
101 	buf[3] = (blocks >> 32) & 0xff;
102 	buf[4] = (blocks >> 24) & 0xff;
103 	buf[5] = (blocks >> 16) & 0xff;
104 	buf[6] = (blocks >> 8) & 0xff;
105 	buf[7] = blocks & 0xff;
106 	buf[8] = (dev->dev_attrib.block_size >> 24) & 0xff;
107 	buf[9] = (dev->dev_attrib.block_size >> 16) & 0xff;
108 	buf[10] = (dev->dev_attrib.block_size >> 8) & 0xff;
109 	buf[11] = dev->dev_attrib.block_size & 0xff;
110 	/*
111 	 * Set P_TYPE and PROT_EN bits for DIF support
112 	 */
113 	if (sess->sup_prot_ops & (TARGET_PROT_DIN_PASS | TARGET_PROT_DOUT_PASS)) {
114 		if (dev->dev_attrib.pi_prot_type)
115 			buf[12] = (dev->dev_attrib.pi_prot_type - 1) << 1 | 0x1;
116 	}
117 
118 	if (dev->transport->get_lbppbe)
119 		buf[13] = dev->transport->get_lbppbe(dev) & 0x0f;
120 
121 	if (dev->transport->get_alignment_offset_lbas) {
122 		u16 lalba = dev->transport->get_alignment_offset_lbas(dev);
123 		buf[14] = (lalba >> 8) & 0x3f;
124 		buf[15] = lalba & 0xff;
125 	}
126 
127 	/*
128 	 * Set Thin Provisioning Enable bit following sbc3r22 in section
129 	 * READ CAPACITY (16) byte 14 if emulate_tpu or emulate_tpws is enabled.
130 	 */
131 	if (dev->dev_attrib.emulate_tpu || dev->dev_attrib.emulate_tpws)
132 		buf[14] |= 0x80;
133 
134 	rbuf = transport_kmap_data_sg(cmd);
135 	if (rbuf) {
136 		memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length));
137 		transport_kunmap_data_sg(cmd);
138 	}
139 
140 	target_complete_cmd_with_length(cmd, GOOD, 32);
141 	return 0;
142 }
143 
sbc_get_write_same_sectors(struct se_cmd * cmd)144 sector_t sbc_get_write_same_sectors(struct se_cmd *cmd)
145 {
146 	u32 num_blocks;
147 
148 	if (cmd->t_task_cdb[0] == WRITE_SAME)
149 		num_blocks = get_unaligned_be16(&cmd->t_task_cdb[7]);
150 	else if (cmd->t_task_cdb[0] == WRITE_SAME_16)
151 		num_blocks = get_unaligned_be32(&cmd->t_task_cdb[10]);
152 	else /* WRITE_SAME_32 via VARIABLE_LENGTH_CMD */
153 		num_blocks = get_unaligned_be32(&cmd->t_task_cdb[28]);
154 
155 	/*
156 	 * Use the explicit range when non zero is supplied, otherwise calculate
157 	 * the remaining range based on ->get_blocks() - starting LBA.
158 	 */
159 	if (num_blocks)
160 		return num_blocks;
161 
162 	return cmd->se_dev->transport->get_blocks(cmd->se_dev) -
163 		cmd->t_task_lba + 1;
164 }
165 EXPORT_SYMBOL(sbc_get_write_same_sectors);
166 
167 static sense_reason_t
sbc_emulate_noop(struct se_cmd * cmd)168 sbc_emulate_noop(struct se_cmd *cmd)
169 {
170 	target_complete_cmd(cmd, GOOD);
171 	return 0;
172 }
173 
sbc_get_size(struct se_cmd * cmd,u32 sectors)174 static inline u32 sbc_get_size(struct se_cmd *cmd, u32 sectors)
175 {
176 	return cmd->se_dev->dev_attrib.block_size * sectors;
177 }
178 
transport_get_sectors_6(unsigned char * cdb)179 static inline u32 transport_get_sectors_6(unsigned char *cdb)
180 {
181 	/*
182 	 * Use 8-bit sector value.  SBC-3 says:
183 	 *
184 	 *   A TRANSFER LENGTH field set to zero specifies that 256
185 	 *   logical blocks shall be written.  Any other value
186 	 *   specifies the number of logical blocks that shall be
187 	 *   written.
188 	 */
189 	return cdb[4] ? : 256;
190 }
191 
transport_get_sectors_10(unsigned char * cdb)192 static inline u32 transport_get_sectors_10(unsigned char *cdb)
193 {
194 	return (u32)(cdb[7] << 8) + cdb[8];
195 }
196 
transport_get_sectors_12(unsigned char * cdb)197 static inline u32 transport_get_sectors_12(unsigned char *cdb)
198 {
199 	return (u32)(cdb[6] << 24) + (cdb[7] << 16) + (cdb[8] << 8) + cdb[9];
200 }
201 
transport_get_sectors_16(unsigned char * cdb)202 static inline u32 transport_get_sectors_16(unsigned char *cdb)
203 {
204 	return (u32)(cdb[10] << 24) + (cdb[11] << 16) +
205 		    (cdb[12] << 8) + cdb[13];
206 }
207 
208 /*
209  * Used for VARIABLE_LENGTH_CDB WRITE_32 and READ_32 variants
210  */
transport_get_sectors_32(unsigned char * cdb)211 static inline u32 transport_get_sectors_32(unsigned char *cdb)
212 {
213 	return (u32)(cdb[28] << 24) + (cdb[29] << 16) +
214 		    (cdb[30] << 8) + cdb[31];
215 
216 }
217 
transport_lba_21(unsigned char * cdb)218 static inline u32 transport_lba_21(unsigned char *cdb)
219 {
220 	return ((cdb[1] & 0x1f) << 16) | (cdb[2] << 8) | cdb[3];
221 }
222 
transport_lba_32(unsigned char * cdb)223 static inline u32 transport_lba_32(unsigned char *cdb)
224 {
225 	return (cdb[2] << 24) | (cdb[3] << 16) | (cdb[4] << 8) | cdb[5];
226 }
227 
transport_lba_64(unsigned char * cdb)228 static inline unsigned long long transport_lba_64(unsigned char *cdb)
229 {
230 	unsigned int __v1, __v2;
231 
232 	__v1 = (cdb[2] << 24) | (cdb[3] << 16) | (cdb[4] << 8) | cdb[5];
233 	__v2 = (cdb[6] << 24) | (cdb[7] << 16) | (cdb[8] << 8) | cdb[9];
234 
235 	return ((unsigned long long)__v2) | (unsigned long long)__v1 << 32;
236 }
237 
238 /*
239  * For VARIABLE_LENGTH_CDB w/ 32 byte extended CDBs
240  */
transport_lba_64_ext(unsigned char * cdb)241 static inline unsigned long long transport_lba_64_ext(unsigned char *cdb)
242 {
243 	unsigned int __v1, __v2;
244 
245 	__v1 = (cdb[12] << 24) | (cdb[13] << 16) | (cdb[14] << 8) | cdb[15];
246 	__v2 = (cdb[16] << 24) | (cdb[17] << 16) | (cdb[18] << 8) | cdb[19];
247 
248 	return ((unsigned long long)__v2) | (unsigned long long)__v1 << 32;
249 }
250 
251 static sense_reason_t
sbc_setup_write_same(struct se_cmd * cmd,unsigned char * flags,struct sbc_ops * ops)252 sbc_setup_write_same(struct se_cmd *cmd, unsigned char *flags, struct sbc_ops *ops)
253 {
254 	struct se_device *dev = cmd->se_dev;
255 	sector_t end_lba = dev->transport->get_blocks(dev) + 1;
256 	unsigned int sectors = sbc_get_write_same_sectors(cmd);
257 
258 	if ((flags[0] & 0x04) || (flags[0] & 0x02)) {
259 		pr_err("WRITE_SAME PBDATA and LBDATA"
260 			" bits not supported for Block Discard"
261 			" Emulation\n");
262 		return TCM_UNSUPPORTED_SCSI_OPCODE;
263 	}
264 	if (sectors > cmd->se_dev->dev_attrib.max_write_same_len) {
265 		pr_warn("WRITE_SAME sectors: %u exceeds max_write_same_len: %u\n",
266 			sectors, cmd->se_dev->dev_attrib.max_write_same_len);
267 		return TCM_INVALID_CDB_FIELD;
268 	}
269 	/*
270 	 * Sanity check for LBA wrap and request past end of device.
271 	 */
272 	if (((cmd->t_task_lba + sectors) < cmd->t_task_lba) ||
273 	    ((cmd->t_task_lba + sectors) > end_lba)) {
274 		pr_err("WRITE_SAME exceeds last lba %llu (lba %llu, sectors %u)\n",
275 		       (unsigned long long)end_lba, cmd->t_task_lba, sectors);
276 		return TCM_ADDRESS_OUT_OF_RANGE;
277 	}
278 
279 	/* We always have ANC_SUP == 0 so setting ANCHOR is always an error */
280 	if (flags[0] & 0x10) {
281 		pr_warn("WRITE SAME with ANCHOR not supported\n");
282 		return TCM_INVALID_CDB_FIELD;
283 	}
284 	/*
285 	 * Special case for WRITE_SAME w/ UNMAP=1 that ends up getting
286 	 * translated into block discard requests within backend code.
287 	 */
288 	if (flags[0] & 0x08) {
289 		if (!ops->execute_write_same_unmap)
290 			return TCM_UNSUPPORTED_SCSI_OPCODE;
291 
292 		cmd->execute_cmd = ops->execute_write_same_unmap;
293 		return 0;
294 	}
295 	if (!ops->execute_write_same)
296 		return TCM_UNSUPPORTED_SCSI_OPCODE;
297 
298 	cmd->execute_cmd = ops->execute_write_same;
299 	return 0;
300 }
301 
xdreadwrite_callback(struct se_cmd * cmd,bool success,int * post_ret)302 static sense_reason_t xdreadwrite_callback(struct se_cmd *cmd, bool success,
303 					   int *post_ret)
304 {
305 	unsigned char *buf, *addr;
306 	struct scatterlist *sg;
307 	unsigned int offset;
308 	sense_reason_t ret = TCM_NO_SENSE;
309 	int i, count;
310 	/*
311 	 * From sbc3r22.pdf section 5.48 XDWRITEREAD (10) command
312 	 *
313 	 * 1) read the specified logical block(s);
314 	 * 2) transfer logical blocks from the data-out buffer;
315 	 * 3) XOR the logical blocks transferred from the data-out buffer with
316 	 *    the logical blocks read, storing the resulting XOR data in a buffer;
317 	 * 4) if the DISABLE WRITE bit is set to zero, then write the logical
318 	 *    blocks transferred from the data-out buffer; and
319 	 * 5) transfer the resulting XOR data to the data-in buffer.
320 	 */
321 	buf = kmalloc(cmd->data_length, GFP_KERNEL);
322 	if (!buf) {
323 		pr_err("Unable to allocate xor_callback buf\n");
324 		return TCM_OUT_OF_RESOURCES;
325 	}
326 	/*
327 	 * Copy the scatterlist WRITE buffer located at cmd->t_data_sg
328 	 * into the locally allocated *buf
329 	 */
330 	sg_copy_to_buffer(cmd->t_data_sg,
331 			  cmd->t_data_nents,
332 			  buf,
333 			  cmd->data_length);
334 
335 	/*
336 	 * Now perform the XOR against the BIDI read memory located at
337 	 * cmd->t_mem_bidi_list
338 	 */
339 
340 	offset = 0;
341 	for_each_sg(cmd->t_bidi_data_sg, sg, cmd->t_bidi_data_nents, count) {
342 		addr = kmap_atomic(sg_page(sg));
343 		if (!addr) {
344 			ret = TCM_OUT_OF_RESOURCES;
345 			goto out;
346 		}
347 
348 		for (i = 0; i < sg->length; i++)
349 			*(addr + sg->offset + i) ^= *(buf + offset + i);
350 
351 		offset += sg->length;
352 		kunmap_atomic(addr);
353 	}
354 
355 out:
356 	kfree(buf);
357 	return ret;
358 }
359 
360 static sense_reason_t
sbc_execute_rw(struct se_cmd * cmd)361 sbc_execute_rw(struct se_cmd *cmd)
362 {
363 	return cmd->execute_rw(cmd, cmd->t_data_sg, cmd->t_data_nents,
364 			       cmd->data_direction);
365 }
366 
compare_and_write_post(struct se_cmd * cmd,bool success,int * post_ret)367 static sense_reason_t compare_and_write_post(struct se_cmd *cmd, bool success,
368 					     int *post_ret)
369 {
370 	struct se_device *dev = cmd->se_dev;
371 
372 	/*
373 	 * Only set SCF_COMPARE_AND_WRITE_POST to force a response fall-through
374 	 * within target_complete_ok_work() if the command was successfully
375 	 * sent to the backend driver.
376 	 */
377 	spin_lock_irq(&cmd->t_state_lock);
378 	if ((cmd->transport_state & CMD_T_SENT) && !cmd->scsi_status) {
379 		cmd->se_cmd_flags |= SCF_COMPARE_AND_WRITE_POST;
380 		*post_ret = 1;
381 	}
382 	spin_unlock_irq(&cmd->t_state_lock);
383 
384 	/*
385 	 * Unlock ->caw_sem originally obtained during sbc_compare_and_write()
386 	 * before the original READ I/O submission.
387 	 */
388 	up(&dev->caw_sem);
389 
390 	return TCM_NO_SENSE;
391 }
392 
compare_and_write_callback(struct se_cmd * cmd,bool success,int * post_ret)393 static sense_reason_t compare_and_write_callback(struct se_cmd *cmd, bool success,
394 						 int *post_ret)
395 {
396 	struct se_device *dev = cmd->se_dev;
397 	struct scatterlist *write_sg = NULL, *sg;
398 	unsigned char *buf = NULL, *addr;
399 	struct sg_mapping_iter m;
400 	unsigned int offset = 0, len;
401 	unsigned int nlbas = cmd->t_task_nolb;
402 	unsigned int block_size = dev->dev_attrib.block_size;
403 	unsigned int compare_len = (nlbas * block_size);
404 	sense_reason_t ret = TCM_NO_SENSE;
405 	int rc, i;
406 
407 	/*
408 	 * Handle early failure in transport_generic_request_failure(),
409 	 * which will not have taken ->caw_sem yet..
410 	 */
411 	if (!success && (!cmd->t_data_sg || !cmd->t_bidi_data_sg))
412 		return TCM_NO_SENSE;
413 	/*
414 	 * Handle special case for zero-length COMPARE_AND_WRITE
415 	 */
416 	if (!cmd->data_length)
417 		goto out;
418 	/*
419 	 * Immediately exit + release dev->caw_sem if command has already
420 	 * been failed with a non-zero SCSI status.
421 	 */
422 	if (cmd->scsi_status) {
423 		pr_err("compare_and_write_callback: non zero scsi_status:"
424 			" 0x%02x\n", cmd->scsi_status);
425 		goto out;
426 	}
427 
428 	buf = kzalloc(cmd->data_length, GFP_KERNEL);
429 	if (!buf) {
430 		pr_err("Unable to allocate compare_and_write buf\n");
431 		ret = TCM_OUT_OF_RESOURCES;
432 		goto out;
433 	}
434 
435 	write_sg = kmalloc(sizeof(struct scatterlist) * cmd->t_data_nents,
436 			   GFP_KERNEL);
437 	if (!write_sg) {
438 		pr_err("Unable to allocate compare_and_write sg\n");
439 		ret = TCM_OUT_OF_RESOURCES;
440 		goto out;
441 	}
442 	sg_init_table(write_sg, cmd->t_data_nents);
443 	/*
444 	 * Setup verify and write data payloads from total NumberLBAs.
445 	 */
446 	rc = sg_copy_to_buffer(cmd->t_data_sg, cmd->t_data_nents, buf,
447 			       cmd->data_length);
448 	if (!rc) {
449 		pr_err("sg_copy_to_buffer() failed for compare_and_write\n");
450 		ret = TCM_OUT_OF_RESOURCES;
451 		goto out;
452 	}
453 	/*
454 	 * Compare against SCSI READ payload against verify payload
455 	 */
456 	for_each_sg(cmd->t_bidi_data_sg, sg, cmd->t_bidi_data_nents, i) {
457 		addr = (unsigned char *)kmap_atomic(sg_page(sg));
458 		if (!addr) {
459 			ret = TCM_OUT_OF_RESOURCES;
460 			goto out;
461 		}
462 
463 		len = min(sg->length, compare_len);
464 
465 		if (memcmp(addr, buf + offset, len)) {
466 			pr_warn("Detected MISCOMPARE for addr: %p buf: %p\n",
467 				addr, buf + offset);
468 			kunmap_atomic(addr);
469 			goto miscompare;
470 		}
471 		kunmap_atomic(addr);
472 
473 		offset += len;
474 		compare_len -= len;
475 		if (!compare_len)
476 			break;
477 	}
478 
479 	i = 0;
480 	len = cmd->t_task_nolb * block_size;
481 	sg_miter_start(&m, cmd->t_data_sg, cmd->t_data_nents, SG_MITER_TO_SG);
482 	/*
483 	 * Currently assumes NoLB=1 and SGLs are PAGE_SIZE..
484 	 */
485 	while (len) {
486 		sg_miter_next(&m);
487 
488 		if (block_size < PAGE_SIZE) {
489 			sg_set_page(&write_sg[i], m.page, block_size,
490 				    m.piter.sg->offset + block_size);
491 		} else {
492 			sg_miter_next(&m);
493 			sg_set_page(&write_sg[i], m.page, block_size,
494 				    m.piter.sg->offset);
495 		}
496 		len -= block_size;
497 		i++;
498 	}
499 	sg_miter_stop(&m);
500 	/*
501 	 * Save the original SGL + nents values before updating to new
502 	 * assignments, to be released in transport_free_pages() ->
503 	 * transport_reset_sgl_orig()
504 	 */
505 	cmd->t_data_sg_orig = cmd->t_data_sg;
506 	cmd->t_data_sg = write_sg;
507 	cmd->t_data_nents_orig = cmd->t_data_nents;
508 	cmd->t_data_nents = 1;
509 
510 	cmd->sam_task_attr = MSG_HEAD_TAG;
511 	cmd->transport_complete_callback = compare_and_write_post;
512 	/*
513 	 * Now reset ->execute_cmd() to the normal sbc_execute_rw() handler
514 	 * for submitting the adjusted SGL to write instance user-data.
515 	 */
516 	cmd->execute_cmd = sbc_execute_rw;
517 
518 	spin_lock_irq(&cmd->t_state_lock);
519 	cmd->t_state = TRANSPORT_PROCESSING;
520 	cmd->transport_state |= CMD_T_ACTIVE|CMD_T_BUSY|CMD_T_SENT;
521 	spin_unlock_irq(&cmd->t_state_lock);
522 
523 	__target_execute_cmd(cmd);
524 
525 	kfree(buf);
526 	return ret;
527 
528 miscompare:
529 	pr_warn("Target/%s: Send MISCOMPARE check condition and sense\n",
530 		dev->transport->name);
531 	ret = TCM_MISCOMPARE_VERIFY;
532 out:
533 	/*
534 	 * In the MISCOMPARE or failure case, unlock ->caw_sem obtained in
535 	 * sbc_compare_and_write() before the original READ I/O submission.
536 	 */
537 	up(&dev->caw_sem);
538 	kfree(write_sg);
539 	kfree(buf);
540 	return ret;
541 }
542 
543 static sense_reason_t
sbc_compare_and_write(struct se_cmd * cmd)544 sbc_compare_and_write(struct se_cmd *cmd)
545 {
546 	struct se_device *dev = cmd->se_dev;
547 	sense_reason_t ret;
548 	int rc;
549 	/*
550 	 * Submit the READ first for COMPARE_AND_WRITE to perform the
551 	 * comparision using SGLs at cmd->t_bidi_data_sg..
552 	 */
553 	rc = down_interruptible(&dev->caw_sem);
554 	if ((rc != 0) || signal_pending(current)) {
555 		cmd->transport_complete_callback = NULL;
556 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
557 	}
558 	/*
559 	 * Reset cmd->data_length to individual block_size in order to not
560 	 * confuse backend drivers that depend on this value matching the
561 	 * size of the I/O being submitted.
562 	 */
563 	cmd->data_length = cmd->t_task_nolb * dev->dev_attrib.block_size;
564 
565 	ret = cmd->execute_rw(cmd, cmd->t_bidi_data_sg, cmd->t_bidi_data_nents,
566 			      DMA_FROM_DEVICE);
567 	if (ret) {
568 		cmd->transport_complete_callback = NULL;
569 		up(&dev->caw_sem);
570 		return ret;
571 	}
572 	/*
573 	 * Unlock of dev->caw_sem to occur in compare_and_write_callback()
574 	 * upon MISCOMPARE, or in compare_and_write_done() upon completion
575 	 * of WRITE instance user-data.
576 	 */
577 	return TCM_NO_SENSE;
578 }
579 
580 static int
sbc_set_prot_op_checks(u8 protect,enum target_prot_type prot_type,bool is_write,struct se_cmd * cmd)581 sbc_set_prot_op_checks(u8 protect, enum target_prot_type prot_type,
582 		       bool is_write, struct se_cmd *cmd)
583 {
584 	if (is_write) {
585 		cmd->prot_op = protect ? TARGET_PROT_DOUT_PASS :
586 					 TARGET_PROT_DOUT_INSERT;
587 		switch (protect) {
588 		case 0x0:
589 		case 0x3:
590 			cmd->prot_checks = 0;
591 			break;
592 		case 0x1:
593 		case 0x5:
594 			cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
595 			if (prot_type == TARGET_DIF_TYPE1_PROT)
596 				cmd->prot_checks |= TARGET_DIF_CHECK_REFTAG;
597 			break;
598 		case 0x2:
599 			if (prot_type == TARGET_DIF_TYPE1_PROT)
600 				cmd->prot_checks = TARGET_DIF_CHECK_REFTAG;
601 			break;
602 		case 0x4:
603 			cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
604 			break;
605 		default:
606 			pr_err("Unsupported protect field %d\n", protect);
607 			return -EINVAL;
608 		}
609 	} else {
610 		cmd->prot_op = protect ? TARGET_PROT_DIN_PASS :
611 					 TARGET_PROT_DIN_STRIP;
612 		switch (protect) {
613 		case 0x0:
614 		case 0x1:
615 		case 0x5:
616 			cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
617 			if (prot_type == TARGET_DIF_TYPE1_PROT)
618 				cmd->prot_checks |= TARGET_DIF_CHECK_REFTAG;
619 			break;
620 		case 0x2:
621 			if (prot_type == TARGET_DIF_TYPE1_PROT)
622 				cmd->prot_checks = TARGET_DIF_CHECK_REFTAG;
623 			break;
624 		case 0x3:
625 			cmd->prot_checks = 0;
626 			break;
627 		case 0x4:
628 			cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
629 			break;
630 		default:
631 			pr_err("Unsupported protect field %d\n", protect);
632 			return -EINVAL;
633 		}
634 	}
635 
636 	return 0;
637 }
638 
639 static bool
sbc_check_prot(struct se_device * dev,struct se_cmd * cmd,unsigned char * cdb,u32 sectors,bool is_write)640 sbc_check_prot(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb,
641 	       u32 sectors, bool is_write)
642 {
643 	u8 protect = cdb[1] >> 5;
644 
645 	if ((!cmd->t_prot_sg || !cmd->t_prot_nents) && cmd->prot_pto)
646 		return true;
647 
648 	switch (dev->dev_attrib.pi_prot_type) {
649 	case TARGET_DIF_TYPE3_PROT:
650 		cmd->reftag_seed = 0xffffffff;
651 		break;
652 	case TARGET_DIF_TYPE2_PROT:
653 		if (protect)
654 			return false;
655 
656 		cmd->reftag_seed = cmd->t_task_lba;
657 		break;
658 	case TARGET_DIF_TYPE1_PROT:
659 		cmd->reftag_seed = cmd->t_task_lba;
660 		break;
661 	case TARGET_DIF_TYPE0_PROT:
662 	default:
663 		return true;
664 	}
665 
666 	if (sbc_set_prot_op_checks(protect, dev->dev_attrib.pi_prot_type,
667 				   is_write, cmd))
668 		return false;
669 
670 	cmd->prot_type = dev->dev_attrib.pi_prot_type;
671 	cmd->prot_length = dev->prot_length * sectors;
672 
673 	/**
674 	 * In case protection information exists over the wire
675 	 * we modify command data length to describe pure data.
676 	 * The actual transfer length is data length + protection
677 	 * length
678 	 **/
679 	if (protect)
680 		cmd->data_length = sectors * dev->dev_attrib.block_size;
681 
682 	pr_debug("%s: prot_type=%d, data_length=%d, prot_length=%d "
683 		 "prot_op=%d prot_checks=%d\n",
684 		 __func__, cmd->prot_type, cmd->data_length, cmd->prot_length,
685 		 cmd->prot_op, cmd->prot_checks);
686 
687 	return true;
688 }
689 
690 sense_reason_t
sbc_parse_cdb(struct se_cmd * cmd,struct sbc_ops * ops)691 sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
692 {
693 	struct se_device *dev = cmd->se_dev;
694 	unsigned char *cdb = cmd->t_task_cdb;
695 	unsigned int size;
696 	u32 sectors = 0;
697 	sense_reason_t ret;
698 
699 	switch (cdb[0]) {
700 	case READ_6:
701 		sectors = transport_get_sectors_6(cdb);
702 		cmd->t_task_lba = transport_lba_21(cdb);
703 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
704 		cmd->execute_rw = ops->execute_rw;
705 		cmd->execute_cmd = sbc_execute_rw;
706 		break;
707 	case READ_10:
708 		sectors = transport_get_sectors_10(cdb);
709 		cmd->t_task_lba = transport_lba_32(cdb);
710 
711 		if (!sbc_check_prot(dev, cmd, cdb, sectors, false))
712 			return TCM_UNSUPPORTED_SCSI_OPCODE;
713 
714 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
715 		cmd->execute_rw = ops->execute_rw;
716 		cmd->execute_cmd = sbc_execute_rw;
717 		break;
718 	case READ_12:
719 		sectors = transport_get_sectors_12(cdb);
720 		cmd->t_task_lba = transport_lba_32(cdb);
721 
722 		if (!sbc_check_prot(dev, cmd, cdb, sectors, false))
723 			return TCM_UNSUPPORTED_SCSI_OPCODE;
724 
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 READ_16:
730 		sectors = transport_get_sectors_16(cdb);
731 		cmd->t_task_lba = transport_lba_64(cdb);
732 
733 		if (!sbc_check_prot(dev, cmd, cdb, sectors, false))
734 			return TCM_UNSUPPORTED_SCSI_OPCODE;
735 
736 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
737 		cmd->execute_rw = ops->execute_rw;
738 		cmd->execute_cmd = sbc_execute_rw;
739 		break;
740 	case WRITE_6:
741 		sectors = transport_get_sectors_6(cdb);
742 		cmd->t_task_lba = transport_lba_21(cdb);
743 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
744 		cmd->execute_rw = ops->execute_rw;
745 		cmd->execute_cmd = sbc_execute_rw;
746 		break;
747 	case WRITE_10:
748 	case WRITE_VERIFY:
749 		sectors = transport_get_sectors_10(cdb);
750 		cmd->t_task_lba = transport_lba_32(cdb);
751 
752 		if (!sbc_check_prot(dev, cmd, cdb, sectors, true))
753 			return TCM_UNSUPPORTED_SCSI_OPCODE;
754 
755 		if (cdb[1] & 0x8)
756 			cmd->se_cmd_flags |= SCF_FUA;
757 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
758 		cmd->execute_rw = ops->execute_rw;
759 		cmd->execute_cmd = sbc_execute_rw;
760 		break;
761 	case WRITE_12:
762 		sectors = transport_get_sectors_12(cdb);
763 		cmd->t_task_lba = transport_lba_32(cdb);
764 
765 		if (!sbc_check_prot(dev, cmd, cdb, sectors, true))
766 			return TCM_UNSUPPORTED_SCSI_OPCODE;
767 
768 		if (cdb[1] & 0x8)
769 			cmd->se_cmd_flags |= SCF_FUA;
770 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
771 		cmd->execute_rw = ops->execute_rw;
772 		cmd->execute_cmd = sbc_execute_rw;
773 		break;
774 	case WRITE_16:
775 		sectors = transport_get_sectors_16(cdb);
776 		cmd->t_task_lba = transport_lba_64(cdb);
777 
778 		if (!sbc_check_prot(dev, cmd, cdb, sectors, true))
779 			return TCM_UNSUPPORTED_SCSI_OPCODE;
780 
781 		if (cdb[1] & 0x8)
782 			cmd->se_cmd_flags |= SCF_FUA;
783 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
784 		cmd->execute_rw = ops->execute_rw;
785 		cmd->execute_cmd = sbc_execute_rw;
786 		break;
787 	case XDWRITEREAD_10:
788 		if (cmd->data_direction != DMA_TO_DEVICE ||
789 		    !(cmd->se_cmd_flags & SCF_BIDI))
790 			return TCM_INVALID_CDB_FIELD;
791 		sectors = transport_get_sectors_10(cdb);
792 
793 		cmd->t_task_lba = transport_lba_32(cdb);
794 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
795 
796 		/*
797 		 * Setup BIDI XOR callback to be run after I/O completion.
798 		 */
799 		cmd->execute_rw = ops->execute_rw;
800 		cmd->execute_cmd = sbc_execute_rw;
801 		cmd->transport_complete_callback = &xdreadwrite_callback;
802 		if (cdb[1] & 0x8)
803 			cmd->se_cmd_flags |= SCF_FUA;
804 		break;
805 	case VARIABLE_LENGTH_CMD:
806 	{
807 		u16 service_action = get_unaligned_be16(&cdb[8]);
808 		switch (service_action) {
809 		case XDWRITEREAD_32:
810 			sectors = transport_get_sectors_32(cdb);
811 
812 			/*
813 			 * Use WRITE_32 and READ_32 opcodes for the emulated
814 			 * XDWRITE_READ_32 logic.
815 			 */
816 			cmd->t_task_lba = transport_lba_64_ext(cdb);
817 			cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
818 
819 			/*
820 			 * Setup BIDI XOR callback to be run during after I/O
821 			 * completion.
822 			 */
823 			cmd->execute_rw = ops->execute_rw;
824 			cmd->execute_cmd = sbc_execute_rw;
825 			cmd->transport_complete_callback = &xdreadwrite_callback;
826 			if (cdb[1] & 0x8)
827 				cmd->se_cmd_flags |= SCF_FUA;
828 			break;
829 		case WRITE_SAME_32:
830 			sectors = transport_get_sectors_32(cdb);
831 			if (!sectors) {
832 				pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not"
833 				       " supported\n");
834 				return TCM_INVALID_CDB_FIELD;
835 			}
836 
837 			size = sbc_get_size(cmd, 1);
838 			cmd->t_task_lba = get_unaligned_be64(&cdb[12]);
839 
840 			ret = sbc_setup_write_same(cmd, &cdb[10], ops);
841 			if (ret)
842 				return ret;
843 			break;
844 		default:
845 			pr_err("VARIABLE_LENGTH_CMD service action"
846 				" 0x%04x not supported\n", service_action);
847 			return TCM_UNSUPPORTED_SCSI_OPCODE;
848 		}
849 		break;
850 	}
851 	case COMPARE_AND_WRITE:
852 		sectors = cdb[13];
853 		/*
854 		 * Currently enforce COMPARE_AND_WRITE for a single sector
855 		 */
856 		if (sectors > 1) {
857 			pr_err("COMPARE_AND_WRITE contains NoLB: %u greater"
858 			       " than 1\n", sectors);
859 			return TCM_INVALID_CDB_FIELD;
860 		}
861 		/*
862 		 * Double size because we have two buffers, note that
863 		 * zero is not an error..
864 		 */
865 		size = 2 * sbc_get_size(cmd, sectors);
866 		cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
867 		cmd->t_task_nolb = sectors;
868 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB | SCF_COMPARE_AND_WRITE;
869 		cmd->execute_rw = ops->execute_rw;
870 		cmd->execute_cmd = sbc_compare_and_write;
871 		cmd->transport_complete_callback = compare_and_write_callback;
872 		break;
873 	case READ_CAPACITY:
874 		size = READ_CAP_LEN;
875 		cmd->execute_cmd = sbc_emulate_readcapacity;
876 		break;
877 	case SERVICE_ACTION_IN:
878 		switch (cmd->t_task_cdb[1] & 0x1f) {
879 		case SAI_READ_CAPACITY_16:
880 			cmd->execute_cmd = sbc_emulate_readcapacity_16;
881 			break;
882 		case SAI_REPORT_REFERRALS:
883 			cmd->execute_cmd = target_emulate_report_referrals;
884 			break;
885 		default:
886 			pr_err("Unsupported SA: 0x%02x\n",
887 				cmd->t_task_cdb[1] & 0x1f);
888 			return TCM_INVALID_CDB_FIELD;
889 		}
890 		size = (cdb[10] << 24) | (cdb[11] << 16) |
891 		       (cdb[12] << 8) | cdb[13];
892 		break;
893 	case SYNCHRONIZE_CACHE:
894 	case SYNCHRONIZE_CACHE_16:
895 		if (cdb[0] == SYNCHRONIZE_CACHE) {
896 			sectors = transport_get_sectors_10(cdb);
897 			cmd->t_task_lba = transport_lba_32(cdb);
898 		} else {
899 			sectors = transport_get_sectors_16(cdb);
900 			cmd->t_task_lba = transport_lba_64(cdb);
901 		}
902 		if (ops->execute_sync_cache) {
903 			cmd->execute_cmd = ops->execute_sync_cache;
904 			goto check_lba;
905 		}
906 		size = 0;
907 		cmd->execute_cmd = sbc_emulate_noop;
908 		break;
909 	case UNMAP:
910 		if (!ops->execute_unmap)
911 			return TCM_UNSUPPORTED_SCSI_OPCODE;
912 
913 		size = get_unaligned_be16(&cdb[7]);
914 		cmd->execute_cmd = ops->execute_unmap;
915 		break;
916 	case WRITE_SAME_16:
917 		sectors = transport_get_sectors_16(cdb);
918 		if (!sectors) {
919 			pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
920 			return TCM_INVALID_CDB_FIELD;
921 		}
922 
923 		size = sbc_get_size(cmd, 1);
924 		cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
925 
926 		ret = sbc_setup_write_same(cmd, &cdb[1], ops);
927 		if (ret)
928 			return ret;
929 		break;
930 	case WRITE_SAME:
931 		sectors = transport_get_sectors_10(cdb);
932 		if (!sectors) {
933 			pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
934 			return TCM_INVALID_CDB_FIELD;
935 		}
936 
937 		size = sbc_get_size(cmd, 1);
938 		cmd->t_task_lba = get_unaligned_be32(&cdb[2]);
939 
940 		/*
941 		 * Follow sbcr26 with WRITE_SAME (10) and check for the existence
942 		 * of byte 1 bit 3 UNMAP instead of original reserved field
943 		 */
944 		ret = sbc_setup_write_same(cmd, &cdb[1], ops);
945 		if (ret)
946 			return ret;
947 		break;
948 	case VERIFY:
949 	case VERIFY_16:
950 		size = 0;
951 		if (cdb[0] == VERIFY) {
952 			sectors = transport_get_sectors_10(cdb);
953 			cmd->t_task_lba = transport_lba_32(cdb);
954 		} else {
955 			sectors = transport_get_sectors_16(cdb);
956 			cmd->t_task_lba = transport_lba_64(cdb);
957 		}
958 		cmd->execute_cmd = sbc_emulate_noop;
959 		goto check_lba;
960 	case REZERO_UNIT:
961 	case SEEK_6:
962 	case SEEK_10:
963 		/*
964 		 * There are still clients out there which use these old SCSI-2
965 		 * commands. This mainly happens when running VMs with legacy
966 		 * guest systems, connected via SCSI command pass-through to
967 		 * iSCSI targets. Make them happy and return status GOOD.
968 		 */
969 		size = 0;
970 		cmd->execute_cmd = sbc_emulate_noop;
971 		break;
972 	default:
973 		ret = spc_parse_cdb(cmd, &size);
974 		if (ret)
975 			return ret;
976 	}
977 
978 	/* reject any command that we don't have a handler for */
979 	if (!cmd->execute_cmd)
980 		return TCM_UNSUPPORTED_SCSI_OPCODE;
981 
982 	if (cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
983 		unsigned long long end_lba;
984 check_lba:
985 		end_lba = dev->transport->get_blocks(dev) + 1;
986 		if (((cmd->t_task_lba + sectors) < cmd->t_task_lba) ||
987 		    ((cmd->t_task_lba + sectors) > end_lba)) {
988 			pr_err("cmd exceeds last lba %llu "
989 				"(lba %llu, sectors %u)\n",
990 				end_lba, cmd->t_task_lba, sectors);
991 			return TCM_ADDRESS_OUT_OF_RANGE;
992 		}
993 
994 		if (!(cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE))
995 			size = sbc_get_size(cmd, sectors);
996 	}
997 
998 	return target_cmd_size_check(cmd, size);
999 }
1000 EXPORT_SYMBOL(sbc_parse_cdb);
1001 
sbc_get_device_type(struct se_device * dev)1002 u32 sbc_get_device_type(struct se_device *dev)
1003 {
1004 	return TYPE_DISK;
1005 }
1006 EXPORT_SYMBOL(sbc_get_device_type);
1007 
1008 sense_reason_t
sbc_execute_unmap(struct se_cmd * cmd,sense_reason_t (* do_unmap_fn)(struct se_cmd *,void *,sector_t,sector_t),void * priv)1009 sbc_execute_unmap(struct se_cmd *cmd,
1010 	sense_reason_t (*do_unmap_fn)(struct se_cmd *, void *,
1011 				      sector_t, sector_t),
1012 	void *priv)
1013 {
1014 	struct se_device *dev = cmd->se_dev;
1015 	unsigned char *buf, *ptr = NULL;
1016 	sector_t lba;
1017 	int size;
1018 	u32 range;
1019 	sense_reason_t ret = 0;
1020 	int dl, bd_dl;
1021 
1022 	/* We never set ANC_SUP */
1023 	if (cmd->t_task_cdb[1])
1024 		return TCM_INVALID_CDB_FIELD;
1025 
1026 	if (cmd->data_length == 0) {
1027 		target_complete_cmd(cmd, SAM_STAT_GOOD);
1028 		return 0;
1029 	}
1030 
1031 	if (cmd->data_length < 8) {
1032 		pr_warn("UNMAP parameter list length %u too small\n",
1033 			cmd->data_length);
1034 		return TCM_PARAMETER_LIST_LENGTH_ERROR;
1035 	}
1036 
1037 	buf = transport_kmap_data_sg(cmd);
1038 	if (!buf)
1039 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1040 
1041 	dl = get_unaligned_be16(&buf[0]);
1042 	bd_dl = get_unaligned_be16(&buf[2]);
1043 
1044 	size = cmd->data_length - 8;
1045 	if (bd_dl > size)
1046 		pr_warn("UNMAP parameter list length %u too small, ignoring bd_dl %u\n",
1047 			cmd->data_length, bd_dl);
1048 	else
1049 		size = bd_dl;
1050 
1051 	if (size / 16 > dev->dev_attrib.max_unmap_block_desc_count) {
1052 		ret = TCM_INVALID_PARAMETER_LIST;
1053 		goto err;
1054 	}
1055 
1056 	/* First UNMAP block descriptor starts at 8 byte offset */
1057 	ptr = &buf[8];
1058 	pr_debug("UNMAP: Sub: %s Using dl: %u bd_dl: %u size: %u"
1059 		" ptr: %p\n", dev->transport->name, dl, bd_dl, size, ptr);
1060 
1061 	while (size >= 16) {
1062 		lba = get_unaligned_be64(&ptr[0]);
1063 		range = get_unaligned_be32(&ptr[8]);
1064 		pr_debug("UNMAP: Using lba: %llu and range: %u\n",
1065 				 (unsigned long long)lba, range);
1066 
1067 		if (range > dev->dev_attrib.max_unmap_lba_count) {
1068 			ret = TCM_INVALID_PARAMETER_LIST;
1069 			goto err;
1070 		}
1071 
1072 		if (lba + range > dev->transport->get_blocks(dev) + 1) {
1073 			ret = TCM_ADDRESS_OUT_OF_RANGE;
1074 			goto err;
1075 		}
1076 
1077 		ret = do_unmap_fn(cmd, priv, lba, range);
1078 		if (ret)
1079 			goto err;
1080 
1081 		ptr += 16;
1082 		size -= 16;
1083 	}
1084 
1085 err:
1086 	transport_kunmap_data_sg(cmd);
1087 	if (!ret)
1088 		target_complete_cmd(cmd, GOOD);
1089 	return ret;
1090 }
1091 EXPORT_SYMBOL(sbc_execute_unmap);
1092 
1093 void
sbc_dif_generate(struct se_cmd * cmd)1094 sbc_dif_generate(struct se_cmd *cmd)
1095 {
1096 	struct se_device *dev = cmd->se_dev;
1097 	struct se_dif_v1_tuple *sdt;
1098 	struct scatterlist *dsg, *psg = cmd->t_prot_sg;
1099 	sector_t sector = cmd->t_task_lba;
1100 	void *daddr, *paddr;
1101 	int i, j, offset = 0;
1102 
1103 	for_each_sg(cmd->t_data_sg, dsg, cmd->t_data_nents, i) {
1104 		daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1105 		paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1106 
1107 		for (j = 0; j < dsg->length; j += dev->dev_attrib.block_size) {
1108 
1109 			if (offset >= psg->length) {
1110 				kunmap_atomic(paddr);
1111 				psg = sg_next(psg);
1112 				paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1113 				offset = 0;
1114 			}
1115 
1116 			sdt = paddr + offset;
1117 			sdt->guard_tag = cpu_to_be16(crc_t10dif(daddr + j,
1118 						dev->dev_attrib.block_size));
1119 			if (dev->dev_attrib.pi_prot_type == TARGET_DIF_TYPE1_PROT)
1120 				sdt->ref_tag = cpu_to_be32(sector & 0xffffffff);
1121 			sdt->app_tag = 0;
1122 
1123 			pr_debug("DIF WRITE INSERT sector: %llu guard_tag: 0x%04x"
1124 				 " app_tag: 0x%04x ref_tag: %u\n",
1125 				 (unsigned long long)sector, sdt->guard_tag,
1126 				 sdt->app_tag, be32_to_cpu(sdt->ref_tag));
1127 
1128 			sector++;
1129 			offset += sizeof(struct se_dif_v1_tuple);
1130 		}
1131 
1132 		kunmap_atomic(paddr);
1133 		kunmap_atomic(daddr);
1134 	}
1135 }
1136 
1137 static sense_reason_t
sbc_dif_v1_verify(struct se_device * dev,struct se_dif_v1_tuple * sdt,const void * p,sector_t sector,unsigned int ei_lba)1138 sbc_dif_v1_verify(struct se_device *dev, struct se_dif_v1_tuple *sdt,
1139 		  const void *p, sector_t sector, unsigned int ei_lba)
1140 {
1141 	int block_size = dev->dev_attrib.block_size;
1142 	__be16 csum;
1143 
1144 	csum = cpu_to_be16(crc_t10dif(p, block_size));
1145 
1146 	if (sdt->guard_tag != csum) {
1147 		pr_err("DIFv1 checksum failed on sector %llu guard tag 0x%04x"
1148 			" csum 0x%04x\n", (unsigned long long)sector,
1149 			be16_to_cpu(sdt->guard_tag), be16_to_cpu(csum));
1150 		return TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED;
1151 	}
1152 
1153 	if (dev->dev_attrib.pi_prot_type == TARGET_DIF_TYPE1_PROT &&
1154 	    be32_to_cpu(sdt->ref_tag) != (sector & 0xffffffff)) {
1155 		pr_err("DIFv1 Type 1 reference failed on sector: %llu tag: 0x%08x"
1156 		       " sector MSB: 0x%08x\n", (unsigned long long)sector,
1157 		       be32_to_cpu(sdt->ref_tag), (u32)(sector & 0xffffffff));
1158 		return TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;
1159 	}
1160 
1161 	if (dev->dev_attrib.pi_prot_type == TARGET_DIF_TYPE2_PROT &&
1162 	    be32_to_cpu(sdt->ref_tag) != ei_lba) {
1163 		pr_err("DIFv1 Type 2 reference failed on sector: %llu tag: 0x%08x"
1164 		       " ei_lba: 0x%08x\n", (unsigned long long)sector,
1165 			be32_to_cpu(sdt->ref_tag), ei_lba);
1166 		return TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;
1167 	}
1168 
1169 	return 0;
1170 }
1171 
1172 static void
sbc_dif_copy_prot(struct se_cmd * cmd,unsigned int sectors,bool read,struct scatterlist * sg,int sg_off)1173 sbc_dif_copy_prot(struct se_cmd *cmd, unsigned int sectors, bool read,
1174 		  struct scatterlist *sg, int sg_off)
1175 {
1176 	struct se_device *dev = cmd->se_dev;
1177 	struct scatterlist *psg;
1178 	void *paddr, *addr;
1179 	unsigned int i, len, left;
1180 	unsigned int offset = sg_off;
1181 
1182 	left = sectors * dev->prot_length;
1183 
1184 	for_each_sg(cmd->t_prot_sg, psg, cmd->t_prot_nents, i) {
1185 		unsigned int psg_len, copied = 0;
1186 
1187 		paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1188 		psg_len = min(left, psg->length);
1189 		while (psg_len) {
1190 			len = min(psg_len, sg->length - offset);
1191 			addr = kmap_atomic(sg_page(sg)) + sg->offset + offset;
1192 
1193 			if (read)
1194 				memcpy(paddr + copied, addr, len);
1195 			else
1196 				memcpy(addr, paddr + copied, len);
1197 
1198 			left -= len;
1199 			offset += len;
1200 			copied += len;
1201 			psg_len -= len;
1202 
1203 			if (offset >= sg->length) {
1204 				sg = sg_next(sg);
1205 				offset = 0;
1206 			}
1207 			kunmap_atomic(addr);
1208 		}
1209 		kunmap_atomic(paddr);
1210 	}
1211 }
1212 
1213 sense_reason_t
sbc_dif_verify_write(struct se_cmd * cmd,sector_t start,unsigned int sectors,unsigned int ei_lba,struct scatterlist * sg,int sg_off)1214 sbc_dif_verify_write(struct se_cmd *cmd, sector_t start, unsigned int sectors,
1215 		     unsigned int ei_lba, struct scatterlist *sg, int sg_off)
1216 {
1217 	struct se_device *dev = cmd->se_dev;
1218 	struct se_dif_v1_tuple *sdt;
1219 	struct scatterlist *dsg, *psg = cmd->t_prot_sg;
1220 	sector_t sector = start;
1221 	void *daddr, *paddr;
1222 	int i, j, offset = 0;
1223 	sense_reason_t rc;
1224 
1225 	for_each_sg(cmd->t_data_sg, dsg, cmd->t_data_nents, i) {
1226 		daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1227 		paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1228 
1229 		for (j = 0; j < dsg->length; j += dev->dev_attrib.block_size) {
1230 
1231 			if (offset >= psg->length) {
1232 				kunmap_atomic(paddr);
1233 				psg = sg_next(psg);
1234 				paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1235 				offset = 0;
1236 			}
1237 
1238 			sdt = paddr + offset;
1239 
1240 			pr_debug("DIF WRITE sector: %llu guard_tag: 0x%04x"
1241 				 " app_tag: 0x%04x ref_tag: %u\n",
1242 				 (unsigned long long)sector, sdt->guard_tag,
1243 				 sdt->app_tag, be32_to_cpu(sdt->ref_tag));
1244 
1245 			rc = sbc_dif_v1_verify(dev, sdt, daddr + j, sector,
1246 					       ei_lba);
1247 			if (rc) {
1248 				kunmap_atomic(paddr);
1249 				kunmap_atomic(daddr);
1250 				cmd->bad_sector = sector;
1251 				return rc;
1252 			}
1253 
1254 			sector++;
1255 			ei_lba++;
1256 			offset += sizeof(struct se_dif_v1_tuple);
1257 		}
1258 
1259 		kunmap_atomic(paddr);
1260 		kunmap_atomic(daddr);
1261 	}
1262 	sbc_dif_copy_prot(cmd, sectors, false, sg, sg_off);
1263 
1264 	return 0;
1265 }
1266 EXPORT_SYMBOL(sbc_dif_verify_write);
1267 
1268 static sense_reason_t
__sbc_dif_verify_read(struct se_cmd * cmd,sector_t start,unsigned int sectors,unsigned int ei_lba,struct scatterlist * sg,int sg_off)1269 __sbc_dif_verify_read(struct se_cmd *cmd, sector_t start, unsigned int sectors,
1270 		      unsigned int ei_lba, struct scatterlist *sg, int sg_off)
1271 {
1272 	struct se_device *dev = cmd->se_dev;
1273 	struct se_dif_v1_tuple *sdt;
1274 	struct scatterlist *dsg, *psg = sg;
1275 	sector_t sector = start;
1276 	void *daddr, *paddr;
1277 	int i, j, offset = sg_off;
1278 	sense_reason_t rc;
1279 
1280 	for_each_sg(cmd->t_data_sg, dsg, cmd->t_data_nents, i) {
1281 		daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1282 		paddr = kmap_atomic(sg_page(psg)) + sg->offset;
1283 
1284 		for (j = 0; j < dsg->length; j += dev->dev_attrib.block_size) {
1285 
1286 			if (offset >= psg->length) {
1287 				kunmap_atomic(paddr);
1288 				psg = sg_next(psg);
1289 				paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1290 				offset = 0;
1291 			}
1292 
1293 			sdt = paddr + offset;
1294 
1295 			pr_debug("DIF READ sector: %llu guard_tag: 0x%04x"
1296 				 " app_tag: 0x%04x ref_tag: %u\n",
1297 				 (unsigned long long)sector, sdt->guard_tag,
1298 				 sdt->app_tag, be32_to_cpu(sdt->ref_tag));
1299 
1300 			if (sdt->app_tag == cpu_to_be16(0xffff)) {
1301 				sector++;
1302 				offset += sizeof(struct se_dif_v1_tuple);
1303 				continue;
1304 			}
1305 
1306 			rc = sbc_dif_v1_verify(dev, sdt, daddr + j, sector,
1307 					       ei_lba);
1308 			if (rc) {
1309 				kunmap_atomic(paddr);
1310 				kunmap_atomic(daddr);
1311 				cmd->bad_sector = sector;
1312 				return rc;
1313 			}
1314 
1315 			sector++;
1316 			ei_lba++;
1317 			offset += sizeof(struct se_dif_v1_tuple);
1318 		}
1319 
1320 		kunmap_atomic(paddr);
1321 		kunmap_atomic(daddr);
1322 	}
1323 
1324 	return 0;
1325 }
1326 
1327 sense_reason_t
sbc_dif_read_strip(struct se_cmd * cmd)1328 sbc_dif_read_strip(struct se_cmd *cmd)
1329 {
1330 	struct se_device *dev = cmd->se_dev;
1331 	u32 sectors = cmd->prot_length / dev->prot_length;
1332 
1333 	return __sbc_dif_verify_read(cmd, cmd->t_task_lba, sectors, 0,
1334 				     cmd->t_prot_sg, 0);
1335 }
1336 
1337 sense_reason_t
sbc_dif_verify_read(struct se_cmd * cmd,sector_t start,unsigned int sectors,unsigned int ei_lba,struct scatterlist * sg,int sg_off)1338 sbc_dif_verify_read(struct se_cmd *cmd, sector_t start, unsigned int sectors,
1339 		    unsigned int ei_lba, struct scatterlist *sg, int sg_off)
1340 {
1341 	sense_reason_t rc;
1342 
1343 	rc = __sbc_dif_verify_read(cmd, start, sectors, ei_lba, sg, sg_off);
1344 	if (rc)
1345 		return rc;
1346 
1347 	sbc_dif_copy_prot(cmd, sectors, true, sg, sg_off);
1348 	return 0;
1349 }
1350 EXPORT_SYMBOL(sbc_dif_verify_read);
1351