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[karo-tx-linux.git] / drivers / target / target_core_sbc.c
1 /*
2  * SCSI Block Commands (SBC) parsing and emulation.
3  *
4  * (c) Copyright 2002-2013 Datera, Inc.
5  *
6  * Nicholas A. Bellinger <nab@kernel.org>
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License as published by
10  * the Free Software Foundation; either version 2 of the License, or
11  * (at your option) any later version.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  * GNU General Public License for more details.
17  *
18  * You should have received a copy of the GNU General Public License
19  * along with this program; if not, write to the Free Software
20  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
21  */
22
23 #include <linux/kernel.h>
24 #include <linux/module.h>
25 #include <linux/ratelimit.h>
26 #include <linux/crc-t10dif.h>
27 #include <asm/unaligned.h>
28 #include <scsi/scsi.h>
29 #include <scsi/scsi_tcq.h>
30
31 #include <target/target_core_base.h>
32 #include <target/target_core_backend.h>
33 #include <target/target_core_fabric.h>
34
35 #include "target_core_internal.h"
36 #include "target_core_ua.h"
37 #include "target_core_alua.h"
38
39 static sense_reason_t
40 sbc_emulate_readcapacity(struct se_cmd *cmd)
41 {
42         struct se_device *dev = cmd->se_dev;
43         unsigned char *cdb = cmd->t_task_cdb;
44         unsigned long long blocks_long = dev->transport->get_blocks(dev);
45         unsigned char *rbuf;
46         unsigned char buf[8];
47         u32 blocks;
48
49         /*
50          * SBC-2 says:
51          *   If the PMI bit is set to zero and the LOGICAL BLOCK
52          *   ADDRESS field is not set to zero, the device server shall
53          *   terminate the command with CHECK CONDITION status with
54          *   the sense key set to ILLEGAL REQUEST and the additional
55          *   sense code set to INVALID FIELD IN CDB.
56          *
57          * In SBC-3, these fields are obsolete, but some SCSI
58          * compliance tests actually check this, so we might as well
59          * follow SBC-2.
60          */
61         if (!(cdb[8] & 1) && !!(cdb[2] | cdb[3] | cdb[4] | cdb[5]))
62                 return TCM_INVALID_CDB_FIELD;
63
64         if (blocks_long >= 0x00000000ffffffff)
65                 blocks = 0xffffffff;
66         else
67                 blocks = (u32)blocks_long;
68
69         buf[0] = (blocks >> 24) & 0xff;
70         buf[1] = (blocks >> 16) & 0xff;
71         buf[2] = (blocks >> 8) & 0xff;
72         buf[3] = blocks & 0xff;
73         buf[4] = (dev->dev_attrib.block_size >> 24) & 0xff;
74         buf[5] = (dev->dev_attrib.block_size >> 16) & 0xff;
75         buf[6] = (dev->dev_attrib.block_size >> 8) & 0xff;
76         buf[7] = dev->dev_attrib.block_size & 0xff;
77
78         rbuf = transport_kmap_data_sg(cmd);
79         if (rbuf) {
80                 memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length));
81                 transport_kunmap_data_sg(cmd);
82         }
83
84         target_complete_cmd(cmd, GOOD);
85         return 0;
86 }
87
88 static sense_reason_t
89 sbc_emulate_readcapacity_16(struct se_cmd *cmd)
90 {
91         struct se_device *dev = cmd->se_dev;
92         unsigned char *rbuf;
93         unsigned char buf[32];
94         unsigned long long blocks = dev->transport->get_blocks(dev);
95
96         memset(buf, 0, sizeof(buf));
97         buf[0] = (blocks >> 56) & 0xff;
98         buf[1] = (blocks >> 48) & 0xff;
99         buf[2] = (blocks >> 40) & 0xff;
100         buf[3] = (blocks >> 32) & 0xff;
101         buf[4] = (blocks >> 24) & 0xff;
102         buf[5] = (blocks >> 16) & 0xff;
103         buf[6] = (blocks >> 8) & 0xff;
104         buf[7] = blocks & 0xff;
105         buf[8] = (dev->dev_attrib.block_size >> 24) & 0xff;
106         buf[9] = (dev->dev_attrib.block_size >> 16) & 0xff;
107         buf[10] = (dev->dev_attrib.block_size >> 8) & 0xff;
108         buf[11] = dev->dev_attrib.block_size & 0xff;
109         /*
110          * Set P_TYPE and PROT_EN bits for DIF support
111          */
112         if (dev->dev_attrib.pi_prot_type)
113                 buf[12] = (dev->dev_attrib.pi_prot_type - 1) << 1 | 0x1;
114
115         if (dev->transport->get_lbppbe)
116                 buf[13] = dev->transport->get_lbppbe(dev) & 0x0f;
117
118         if (dev->transport->get_alignment_offset_lbas) {
119                 u16 lalba = dev->transport->get_alignment_offset_lbas(dev);
120                 buf[14] = (lalba >> 8) & 0x3f;
121                 buf[15] = lalba & 0xff;
122         }
123
124         /*
125          * Set Thin Provisioning Enable bit following sbc3r22 in section
126          * READ CAPACITY (16) byte 14 if emulate_tpu or emulate_tpws is enabled.
127          */
128         if (dev->dev_attrib.emulate_tpu || dev->dev_attrib.emulate_tpws)
129                 buf[14] |= 0x80;
130
131         rbuf = transport_kmap_data_sg(cmd);
132         if (rbuf) {
133                 memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length));
134                 transport_kunmap_data_sg(cmd);
135         }
136
137         target_complete_cmd(cmd, GOOD);
138         return 0;
139 }
140
141 sector_t sbc_get_write_same_sectors(struct se_cmd *cmd)
142 {
143         u32 num_blocks;
144
145         if (cmd->t_task_cdb[0] == WRITE_SAME)
146                 num_blocks = get_unaligned_be16(&cmd->t_task_cdb[7]);
147         else if (cmd->t_task_cdb[0] == WRITE_SAME_16)
148                 num_blocks = get_unaligned_be32(&cmd->t_task_cdb[10]);
149         else /* WRITE_SAME_32 via VARIABLE_LENGTH_CMD */
150                 num_blocks = get_unaligned_be32(&cmd->t_task_cdb[28]);
151
152         /*
153          * Use the explicit range when non zero is supplied, otherwise calculate
154          * the remaining range based on ->get_blocks() - starting LBA.
155          */
156         if (num_blocks)
157                 return num_blocks;
158
159         return cmd->se_dev->transport->get_blocks(cmd->se_dev) -
160                 cmd->t_task_lba + 1;
161 }
162 EXPORT_SYMBOL(sbc_get_write_same_sectors);
163
164 static sense_reason_t
165 sbc_emulate_noop(struct se_cmd *cmd)
166 {
167         target_complete_cmd(cmd, GOOD);
168         return 0;
169 }
170
171 static inline u32 sbc_get_size(struct se_cmd *cmd, u32 sectors)
172 {
173         return cmd->se_dev->dev_attrib.block_size * sectors;
174 }
175
176 static int sbc_check_valid_sectors(struct se_cmd *cmd)
177 {
178         struct se_device *dev = cmd->se_dev;
179         unsigned long long end_lba;
180         u32 sectors;
181
182         sectors = cmd->data_length / dev->dev_attrib.block_size;
183         end_lba = dev->transport->get_blocks(dev) + 1;
184
185         if (cmd->t_task_lba + sectors > end_lba) {
186                 pr_err("target: lba %llu, sectors %u exceeds end lba %llu\n",
187                         cmd->t_task_lba, sectors, end_lba);
188                 return -EINVAL;
189         }
190
191         return 0;
192 }
193
194 static inline u32 transport_get_sectors_6(unsigned char *cdb)
195 {
196         /*
197          * Use 8-bit sector value.  SBC-3 says:
198          *
199          *   A TRANSFER LENGTH field set to zero specifies that 256
200          *   logical blocks shall be written.  Any other value
201          *   specifies the number of logical blocks that shall be
202          *   written.
203          */
204         return cdb[4] ? : 256;
205 }
206
207 static inline u32 transport_get_sectors_10(unsigned char *cdb)
208 {
209         return (u32)(cdb[7] << 8) + cdb[8];
210 }
211
212 static inline u32 transport_get_sectors_12(unsigned char *cdb)
213 {
214         return (u32)(cdb[6] << 24) + (cdb[7] << 16) + (cdb[8] << 8) + cdb[9];
215 }
216
217 static inline u32 transport_get_sectors_16(unsigned char *cdb)
218 {
219         return (u32)(cdb[10] << 24) + (cdb[11] << 16) +
220                     (cdb[12] << 8) + cdb[13];
221 }
222
223 /*
224  * Used for VARIABLE_LENGTH_CDB WRITE_32 and READ_32 variants
225  */
226 static inline u32 transport_get_sectors_32(unsigned char *cdb)
227 {
228         return (u32)(cdb[28] << 24) + (cdb[29] << 16) +
229                     (cdb[30] << 8) + cdb[31];
230
231 }
232
233 static inline u32 transport_lba_21(unsigned char *cdb)
234 {
235         return ((cdb[1] & 0x1f) << 16) | (cdb[2] << 8) | cdb[3];
236 }
237
238 static inline u32 transport_lba_32(unsigned char *cdb)
239 {
240         return (cdb[2] << 24) | (cdb[3] << 16) | (cdb[4] << 8) | cdb[5];
241 }
242
243 static inline unsigned long long transport_lba_64(unsigned char *cdb)
244 {
245         unsigned int __v1, __v2;
246
247         __v1 = (cdb[2] << 24) | (cdb[3] << 16) | (cdb[4] << 8) | cdb[5];
248         __v2 = (cdb[6] << 24) | (cdb[7] << 16) | (cdb[8] << 8) | cdb[9];
249
250         return ((unsigned long long)__v2) | (unsigned long long)__v1 << 32;
251 }
252
253 /*
254  * For VARIABLE_LENGTH_CDB w/ 32 byte extended CDBs
255  */
256 static inline unsigned long long transport_lba_64_ext(unsigned char *cdb)
257 {
258         unsigned int __v1, __v2;
259
260         __v1 = (cdb[12] << 24) | (cdb[13] << 16) | (cdb[14] << 8) | cdb[15];
261         __v2 = (cdb[16] << 24) | (cdb[17] << 16) | (cdb[18] << 8) | cdb[19];
262
263         return ((unsigned long long)__v2) | (unsigned long long)__v1 << 32;
264 }
265
266 static sense_reason_t
267 sbc_setup_write_same(struct se_cmd *cmd, unsigned char *flags, struct sbc_ops *ops)
268 {
269         unsigned int sectors = sbc_get_write_same_sectors(cmd);
270
271         if ((flags[0] & 0x04) || (flags[0] & 0x02)) {
272                 pr_err("WRITE_SAME PBDATA and LBDATA"
273                         " bits not supported for Block Discard"
274                         " Emulation\n");
275                 return TCM_UNSUPPORTED_SCSI_OPCODE;
276         }
277         if (sectors > cmd->se_dev->dev_attrib.max_write_same_len) {
278                 pr_warn("WRITE_SAME sectors: %u exceeds max_write_same_len: %u\n",
279                         sectors, cmd->se_dev->dev_attrib.max_write_same_len);
280                 return TCM_INVALID_CDB_FIELD;
281         }
282         /* We always have ANC_SUP == 0 so setting ANCHOR is always an error */
283         if (flags[0] & 0x10) {
284                 pr_warn("WRITE SAME with ANCHOR not supported\n");
285                 return TCM_INVALID_CDB_FIELD;
286         }
287         /*
288          * Special case for WRITE_SAME w/ UNMAP=1 that ends up getting
289          * translated into block discard requests within backend code.
290          */
291         if (flags[0] & 0x08) {
292                 if (!ops->execute_write_same_unmap)
293                         return TCM_UNSUPPORTED_SCSI_OPCODE;
294
295                 cmd->execute_cmd = ops->execute_write_same_unmap;
296                 return 0;
297         }
298         if (!ops->execute_write_same)
299                 return TCM_UNSUPPORTED_SCSI_OPCODE;
300
301         cmd->execute_cmd = ops->execute_write_same;
302         return 0;
303 }
304
305 static sense_reason_t xdreadwrite_callback(struct se_cmd *cmd)
306 {
307         unsigned char *buf, *addr;
308         struct scatterlist *sg;
309         unsigned int offset;
310         sense_reason_t ret = TCM_NO_SENSE;
311         int i, count;
312         /*
313          * From sbc3r22.pdf section 5.48 XDWRITEREAD (10) command
314          *
315          * 1) read the specified logical block(s);
316          * 2) transfer logical blocks from the data-out buffer;
317          * 3) XOR the logical blocks transferred from the data-out buffer with
318          *    the logical blocks read, storing the resulting XOR data in a buffer;
319          * 4) if the DISABLE WRITE bit is set to zero, then write the logical
320          *    blocks transferred from the data-out buffer; and
321          * 5) transfer the resulting XOR data to the data-in buffer.
322          */
323         buf = kmalloc(cmd->data_length, GFP_KERNEL);
324         if (!buf) {
325                 pr_err("Unable to allocate xor_callback buf\n");
326                 return TCM_OUT_OF_RESOURCES;
327         }
328         /*
329          * Copy the scatterlist WRITE buffer located at cmd->t_data_sg
330          * into the locally allocated *buf
331          */
332         sg_copy_to_buffer(cmd->t_data_sg,
333                           cmd->t_data_nents,
334                           buf,
335                           cmd->data_length);
336
337         /*
338          * Now perform the XOR against the BIDI read memory located at
339          * cmd->t_mem_bidi_list
340          */
341
342         offset = 0;
343         for_each_sg(cmd->t_bidi_data_sg, sg, cmd->t_bidi_data_nents, count) {
344                 addr = kmap_atomic(sg_page(sg));
345                 if (!addr) {
346                         ret = TCM_OUT_OF_RESOURCES;
347                         goto out;
348                 }
349
350                 for (i = 0; i < sg->length; i++)
351                         *(addr + sg->offset + i) ^= *(buf + offset + i);
352
353                 offset += sg->length;
354                 kunmap_atomic(addr);
355         }
356
357 out:
358         kfree(buf);
359         return ret;
360 }
361
362 static sense_reason_t
363 sbc_execute_rw(struct se_cmd *cmd)
364 {
365         return cmd->execute_rw(cmd, cmd->t_data_sg, cmd->t_data_nents,
366                                cmd->data_direction);
367 }
368
369 static sense_reason_t compare_and_write_post(struct se_cmd *cmd)
370 {
371         struct se_device *dev = cmd->se_dev;
372
373         /*
374          * Only set SCF_COMPARE_AND_WRITE_POST to force a response fall-through
375          * within target_complete_ok_work() if the command was successfully
376          * sent to the backend driver.
377          */
378         spin_lock_irq(&cmd->t_state_lock);
379         if ((cmd->transport_state & CMD_T_SENT) && !cmd->scsi_status)
380                 cmd->se_cmd_flags |= SCF_COMPARE_AND_WRITE_POST;
381         spin_unlock_irq(&cmd->t_state_lock);
382
383         /*
384          * Unlock ->caw_sem originally obtained during sbc_compare_and_write()
385          * before the original READ I/O submission.
386          */
387         up(&dev->caw_sem);
388
389         return TCM_NO_SENSE;
390 }
391
392 static sense_reason_t compare_and_write_callback(struct se_cmd *cmd)
393 {
394         struct se_device *dev = cmd->se_dev;
395         struct scatterlist *write_sg = NULL, *sg;
396         unsigned char *buf = NULL, *addr;
397         struct sg_mapping_iter m;
398         unsigned int offset = 0, len;
399         unsigned int nlbas = cmd->t_task_nolb;
400         unsigned int block_size = dev->dev_attrib.block_size;
401         unsigned int compare_len = (nlbas * block_size);
402         sense_reason_t ret = TCM_NO_SENSE;
403         int rc, i;
404
405         /*
406          * Handle early failure in transport_generic_request_failure(),
407          * which will not have taken ->caw_mutex yet..
408          */
409         if (!cmd->t_data_sg || !cmd->t_bidi_data_sg)
410                 return TCM_NO_SENSE;
411         /*
412          * Immediately exit + release dev->caw_sem if command has already
413          * been failed with a non-zero SCSI status.
414          */
415         if (cmd->scsi_status) {
416                 pr_err("compare_and_write_callback: non zero scsi_status:"
417                         " 0x%02x\n", cmd->scsi_status);
418                 goto out;
419         }
420
421         buf = kzalloc(cmd->data_length, GFP_KERNEL);
422         if (!buf) {
423                 pr_err("Unable to allocate compare_and_write buf\n");
424                 ret = TCM_OUT_OF_RESOURCES;
425                 goto out;
426         }
427
428         write_sg = kzalloc(sizeof(struct scatterlist) * cmd->t_data_nents,
429                            GFP_KERNEL);
430         if (!write_sg) {
431                 pr_err("Unable to allocate compare_and_write sg\n");
432                 ret = TCM_OUT_OF_RESOURCES;
433                 goto out;
434         }
435         /*
436          * Setup verify and write data payloads from total NumberLBAs.
437          */
438         rc = sg_copy_to_buffer(cmd->t_data_sg, cmd->t_data_nents, buf,
439                                cmd->data_length);
440         if (!rc) {
441                 pr_err("sg_copy_to_buffer() failed for compare_and_write\n");
442                 ret = TCM_OUT_OF_RESOURCES;
443                 goto out;
444         }
445         /*
446          * Compare against SCSI READ payload against verify payload
447          */
448         for_each_sg(cmd->t_bidi_data_sg, sg, cmd->t_bidi_data_nents, i) {
449                 addr = (unsigned char *)kmap_atomic(sg_page(sg));
450                 if (!addr) {
451                         ret = TCM_OUT_OF_RESOURCES;
452                         goto out;
453                 }
454
455                 len = min(sg->length, compare_len);
456
457                 if (memcmp(addr, buf + offset, len)) {
458                         pr_warn("Detected MISCOMPARE for addr: %p buf: %p\n",
459                                 addr, buf + offset);
460                         kunmap_atomic(addr);
461                         goto miscompare;
462                 }
463                 kunmap_atomic(addr);
464
465                 offset += len;
466                 compare_len -= len;
467                 if (!compare_len)
468                         break;
469         }
470
471         i = 0;
472         len = cmd->t_task_nolb * block_size;
473         sg_miter_start(&m, cmd->t_data_sg, cmd->t_data_nents, SG_MITER_TO_SG);
474         /*
475          * Currently assumes NoLB=1 and SGLs are PAGE_SIZE..
476          */
477         while (len) {
478                 sg_miter_next(&m);
479
480                 if (block_size < PAGE_SIZE) {
481                         sg_set_page(&write_sg[i], m.page, block_size,
482                                     block_size);
483                 } else {
484                         sg_miter_next(&m);
485                         sg_set_page(&write_sg[i], m.page, block_size,
486                                     0);
487                 }
488                 len -= block_size;
489                 i++;
490         }
491         sg_miter_stop(&m);
492         /*
493          * Save the original SGL + nents values before updating to new
494          * assignments, to be released in transport_free_pages() ->
495          * transport_reset_sgl_orig()
496          */
497         cmd->t_data_sg_orig = cmd->t_data_sg;
498         cmd->t_data_sg = write_sg;
499         cmd->t_data_nents_orig = cmd->t_data_nents;
500         cmd->t_data_nents = 1;
501
502         cmd->sam_task_attr = MSG_HEAD_TAG;
503         cmd->transport_complete_callback = compare_and_write_post;
504         /*
505          * Now reset ->execute_cmd() to the normal sbc_execute_rw() handler
506          * for submitting the adjusted SGL to write instance user-data.
507          */
508         cmd->execute_cmd = sbc_execute_rw;
509
510         spin_lock_irq(&cmd->t_state_lock);
511         cmd->t_state = TRANSPORT_PROCESSING;
512         cmd->transport_state |= CMD_T_ACTIVE|CMD_T_BUSY|CMD_T_SENT;
513         spin_unlock_irq(&cmd->t_state_lock);
514
515         __target_execute_cmd(cmd);
516
517         kfree(buf);
518         return ret;
519
520 miscompare:
521         pr_warn("Target/%s: Send MISCOMPARE check condition and sense\n",
522                 dev->transport->name);
523         ret = TCM_MISCOMPARE_VERIFY;
524 out:
525         /*
526          * In the MISCOMPARE or failure case, unlock ->caw_sem obtained in
527          * sbc_compare_and_write() before the original READ I/O submission.
528          */
529         up(&dev->caw_sem);
530         kfree(write_sg);
531         kfree(buf);
532         return ret;
533 }
534
535 static sense_reason_t
536 sbc_compare_and_write(struct se_cmd *cmd)
537 {
538         struct se_device *dev = cmd->se_dev;
539         sense_reason_t ret;
540         int rc;
541         /*
542          * Submit the READ first for COMPARE_AND_WRITE to perform the
543          * comparision using SGLs at cmd->t_bidi_data_sg..
544          */
545         rc = down_interruptible(&dev->caw_sem);
546         if ((rc != 0) || signal_pending(current)) {
547                 cmd->transport_complete_callback = NULL;
548                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
549         }
550         /*
551          * Reset cmd->data_length to individual block_size in order to not
552          * confuse backend drivers that depend on this value matching the
553          * size of the I/O being submitted.
554          */
555         cmd->data_length = cmd->t_task_nolb * dev->dev_attrib.block_size;
556
557         ret = cmd->execute_rw(cmd, cmd->t_bidi_data_sg, cmd->t_bidi_data_nents,
558                               DMA_FROM_DEVICE);
559         if (ret) {
560                 cmd->transport_complete_callback = NULL;
561                 up(&dev->caw_sem);
562                 return ret;
563         }
564         /*
565          * Unlock of dev->caw_sem to occur in compare_and_write_callback()
566          * upon MISCOMPARE, or in compare_and_write_done() upon completion
567          * of WRITE instance user-data.
568          */
569         return TCM_NO_SENSE;
570 }
571
572 static int
573 sbc_set_prot_op_checks(u8 protect, enum target_prot_type prot_type,
574                        bool is_write, struct se_cmd *cmd)
575 {
576         if (is_write) {
577                 cmd->prot_op = protect ? TARGET_PROT_DOUT_PASS :
578                                          TARGET_PROT_DOUT_INSERT;
579                 switch (protect) {
580                 case 0x0:
581                 case 0x3:
582                         cmd->prot_checks = 0;
583                         break;
584                 case 0x1:
585                 case 0x5:
586                         cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
587                         if (prot_type == TARGET_DIF_TYPE1_PROT)
588                                 cmd->prot_checks |= TARGET_DIF_CHECK_REFTAG;
589                         break;
590                 case 0x2:
591                         if (prot_type == TARGET_DIF_TYPE1_PROT)
592                                 cmd->prot_checks = TARGET_DIF_CHECK_REFTAG;
593                         break;
594                 case 0x4:
595                         cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
596                         break;
597                 default:
598                         pr_err("Unsupported protect field %d\n", protect);
599                         return -EINVAL;
600                 }
601         } else {
602                 cmd->prot_op = protect ? TARGET_PROT_DIN_PASS :
603                                          TARGET_PROT_DIN_STRIP;
604                 switch (protect) {
605                 case 0x0:
606                 case 0x1:
607                 case 0x5:
608                         cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
609                         if (prot_type == TARGET_DIF_TYPE1_PROT)
610                                 cmd->prot_checks |= TARGET_DIF_CHECK_REFTAG;
611                         break;
612                 case 0x2:
613                         if (prot_type == TARGET_DIF_TYPE1_PROT)
614                                 cmd->prot_checks = TARGET_DIF_CHECK_REFTAG;
615                         break;
616                 case 0x3:
617                         cmd->prot_checks = 0;
618                         break;
619                 case 0x4:
620                         cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
621                         break;
622                 default:
623                         pr_err("Unsupported protect field %d\n", protect);
624                         return -EINVAL;
625                 }
626         }
627
628         return 0;
629 }
630
631 static bool
632 sbc_check_prot(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb,
633                u32 sectors, bool is_write)
634 {
635         u8 protect = cdb[1] >> 5;
636
637         if ((!cmd->t_prot_sg || !cmd->t_prot_nents) && cmd->prot_pto)
638                 return true;
639
640         switch (dev->dev_attrib.pi_prot_type) {
641         case TARGET_DIF_TYPE3_PROT:
642                 cmd->reftag_seed = 0xffffffff;
643                 break;
644         case TARGET_DIF_TYPE2_PROT:
645                 if (protect)
646                         return false;
647
648                 cmd->reftag_seed = cmd->t_task_lba;
649                 break;
650         case TARGET_DIF_TYPE1_PROT:
651                 cmd->reftag_seed = cmd->t_task_lba;
652                 break;
653         case TARGET_DIF_TYPE0_PROT:
654         default:
655                 return true;
656         }
657
658         if (sbc_set_prot_op_checks(protect, dev->dev_attrib.pi_prot_type,
659                                    is_write, cmd))
660                 return false;
661
662         cmd->prot_type = dev->dev_attrib.pi_prot_type;
663         cmd->prot_length = dev->prot_length * sectors;
664
665         return true;
666 }
667
668 sense_reason_t
669 sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
670 {
671         struct se_device *dev = cmd->se_dev;
672         unsigned char *cdb = cmd->t_task_cdb;
673         unsigned int size;
674         u32 sectors = 0;
675         sense_reason_t ret;
676
677         switch (cdb[0]) {
678         case READ_6:
679                 sectors = transport_get_sectors_6(cdb);
680                 cmd->t_task_lba = transport_lba_21(cdb);
681                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
682                 cmd->execute_rw = ops->execute_rw;
683                 cmd->execute_cmd = sbc_execute_rw;
684                 break;
685         case READ_10:
686                 sectors = transport_get_sectors_10(cdb);
687                 cmd->t_task_lba = transport_lba_32(cdb);
688
689                 if (!sbc_check_prot(dev, cmd, cdb, sectors, false))
690                         return TCM_UNSUPPORTED_SCSI_OPCODE;
691
692                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
693                 cmd->execute_rw = ops->execute_rw;
694                 cmd->execute_cmd = sbc_execute_rw;
695                 break;
696         case READ_12:
697                 sectors = transport_get_sectors_12(cdb);
698                 cmd->t_task_lba = transport_lba_32(cdb);
699
700                 if (!sbc_check_prot(dev, cmd, cdb, sectors, false))
701                         return TCM_UNSUPPORTED_SCSI_OPCODE;
702
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_16:
708                 sectors = transport_get_sectors_16(cdb);
709                 cmd->t_task_lba = transport_lba_64(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 WRITE_6:
719                 sectors = transport_get_sectors_6(cdb);
720                 cmd->t_task_lba = transport_lba_21(cdb);
721                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
722                 cmd->execute_rw = ops->execute_rw;
723                 cmd->execute_cmd = sbc_execute_rw;
724                 break;
725         case WRITE_10:
726         case WRITE_VERIFY:
727                 sectors = transport_get_sectors_10(cdb);
728                 cmd->t_task_lba = transport_lba_32(cdb);
729
730                 if (!sbc_check_prot(dev, cmd, cdb, sectors, true))
731                         return TCM_UNSUPPORTED_SCSI_OPCODE;
732
733                 if (cdb[1] & 0x8)
734                         cmd->se_cmd_flags |= SCF_FUA;
735                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
736                 cmd->execute_rw = ops->execute_rw;
737                 cmd->execute_cmd = sbc_execute_rw;
738                 break;
739         case WRITE_12:
740                 sectors = transport_get_sectors_12(cdb);
741                 cmd->t_task_lba = transport_lba_32(cdb);
742
743                 if (!sbc_check_prot(dev, cmd, cdb, sectors, true))
744                         return TCM_UNSUPPORTED_SCSI_OPCODE;
745
746                 if (cdb[1] & 0x8)
747                         cmd->se_cmd_flags |= SCF_FUA;
748                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
749                 cmd->execute_rw = ops->execute_rw;
750                 cmd->execute_cmd = sbc_execute_rw;
751                 break;
752         case WRITE_16:
753                 sectors = transport_get_sectors_16(cdb);
754                 cmd->t_task_lba = transport_lba_64(cdb);
755
756                 if (!sbc_check_prot(dev, cmd, cdb, sectors, true))
757                         return TCM_UNSUPPORTED_SCSI_OPCODE;
758
759                 if (cdb[1] & 0x8)
760                         cmd->se_cmd_flags |= SCF_FUA;
761                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
762                 cmd->execute_rw = ops->execute_rw;
763                 cmd->execute_cmd = sbc_execute_rw;
764                 break;
765         case XDWRITEREAD_10:
766                 if (cmd->data_direction != DMA_TO_DEVICE ||
767                     !(cmd->se_cmd_flags & SCF_BIDI))
768                         return TCM_INVALID_CDB_FIELD;
769                 sectors = transport_get_sectors_10(cdb);
770
771                 cmd->t_task_lba = transport_lba_32(cdb);
772                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
773
774                 /*
775                  * Setup BIDI XOR callback to be run after I/O completion.
776                  */
777                 cmd->execute_rw = ops->execute_rw;
778                 cmd->execute_cmd = sbc_execute_rw;
779                 cmd->transport_complete_callback = &xdreadwrite_callback;
780                 if (cdb[1] & 0x8)
781                         cmd->se_cmd_flags |= SCF_FUA;
782                 break;
783         case VARIABLE_LENGTH_CMD:
784         {
785                 u16 service_action = get_unaligned_be16(&cdb[8]);
786                 switch (service_action) {
787                 case XDWRITEREAD_32:
788                         sectors = transport_get_sectors_32(cdb);
789
790                         /*
791                          * Use WRITE_32 and READ_32 opcodes for the emulated
792                          * XDWRITE_READ_32 logic.
793                          */
794                         cmd->t_task_lba = transport_lba_64_ext(cdb);
795                         cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
796
797                         /*
798                          * Setup BIDI XOR callback to be run during after I/O
799                          * completion.
800                          */
801                         cmd->execute_rw = ops->execute_rw;
802                         cmd->execute_cmd = sbc_execute_rw;
803                         cmd->transport_complete_callback = &xdreadwrite_callback;
804                         if (cdb[1] & 0x8)
805                                 cmd->se_cmd_flags |= SCF_FUA;
806                         break;
807                 case WRITE_SAME_32:
808                         sectors = transport_get_sectors_32(cdb);
809                         if (!sectors) {
810                                 pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not"
811                                        " supported\n");
812                                 return TCM_INVALID_CDB_FIELD;
813                         }
814
815                         size = sbc_get_size(cmd, 1);
816                         cmd->t_task_lba = get_unaligned_be64(&cdb[12]);
817
818                         ret = sbc_setup_write_same(cmd, &cdb[10], ops);
819                         if (ret)
820                                 return ret;
821                         break;
822                 default:
823                         pr_err("VARIABLE_LENGTH_CMD service action"
824                                 " 0x%04x not supported\n", service_action);
825                         return TCM_UNSUPPORTED_SCSI_OPCODE;
826                 }
827                 break;
828         }
829         case COMPARE_AND_WRITE:
830                 sectors = cdb[13];
831                 /*
832                  * Currently enforce COMPARE_AND_WRITE for a single sector
833                  */
834                 if (sectors > 1) {
835                         pr_err("COMPARE_AND_WRITE contains NoLB: %u greater"
836                                " than 1\n", sectors);
837                         return TCM_INVALID_CDB_FIELD;
838                 }
839                 /*
840                  * Double size because we have two buffers, note that
841                  * zero is not an error..
842                  */
843                 size = 2 * sbc_get_size(cmd, sectors);
844                 cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
845                 cmd->t_task_nolb = sectors;
846                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB | SCF_COMPARE_AND_WRITE;
847                 cmd->execute_rw = ops->execute_rw;
848                 cmd->execute_cmd = sbc_compare_and_write;
849                 cmd->transport_complete_callback = compare_and_write_callback;
850                 break;
851         case READ_CAPACITY:
852                 size = READ_CAP_LEN;
853                 cmd->execute_cmd = sbc_emulate_readcapacity;
854                 break;
855         case SERVICE_ACTION_IN:
856                 switch (cmd->t_task_cdb[1] & 0x1f) {
857                 case SAI_READ_CAPACITY_16:
858                         cmd->execute_cmd = sbc_emulate_readcapacity_16;
859                         break;
860                 case SAI_REPORT_REFERRALS:
861                         cmd->execute_cmd = target_emulate_report_referrals;
862                         break;
863                 default:
864                         pr_err("Unsupported SA: 0x%02x\n",
865                                 cmd->t_task_cdb[1] & 0x1f);
866                         return TCM_INVALID_CDB_FIELD;
867                 }
868                 size = (cdb[10] << 24) | (cdb[11] << 16) |
869                        (cdb[12] << 8) | cdb[13];
870                 break;
871         case SYNCHRONIZE_CACHE:
872         case SYNCHRONIZE_CACHE_16:
873                 if (!ops->execute_sync_cache) {
874                         size = 0;
875                         cmd->execute_cmd = sbc_emulate_noop;
876                         break;
877                 }
878
879                 /*
880                  * Extract LBA and range to be flushed for emulated SYNCHRONIZE_CACHE
881                  */
882                 if (cdb[0] == SYNCHRONIZE_CACHE) {
883                         sectors = transport_get_sectors_10(cdb);
884                         cmd->t_task_lba = transport_lba_32(cdb);
885                 } else {
886                         sectors = transport_get_sectors_16(cdb);
887                         cmd->t_task_lba = transport_lba_64(cdb);
888                 }
889
890                 size = sbc_get_size(cmd, sectors);
891
892                 /*
893                  * Check to ensure that LBA + Range does not exceed past end of
894                  * device for IBLOCK and FILEIO ->do_sync_cache() backend calls
895                  */
896                 if (cmd->t_task_lba || sectors) {
897                         if (sbc_check_valid_sectors(cmd) < 0)
898                                 return TCM_ADDRESS_OUT_OF_RANGE;
899                 }
900                 cmd->execute_cmd = ops->execute_sync_cache;
901                 break;
902         case UNMAP:
903                 if (!ops->execute_unmap)
904                         return TCM_UNSUPPORTED_SCSI_OPCODE;
905
906                 size = get_unaligned_be16(&cdb[7]);
907                 cmd->execute_cmd = ops->execute_unmap;
908                 break;
909         case WRITE_SAME_16:
910                 sectors = transport_get_sectors_16(cdb);
911                 if (!sectors) {
912                         pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
913                         return TCM_INVALID_CDB_FIELD;
914                 }
915
916                 size = sbc_get_size(cmd, 1);
917                 cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
918
919                 ret = sbc_setup_write_same(cmd, &cdb[1], ops);
920                 if (ret)
921                         return ret;
922                 break;
923         case WRITE_SAME:
924                 sectors = transport_get_sectors_10(cdb);
925                 if (!sectors) {
926                         pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
927                         return TCM_INVALID_CDB_FIELD;
928                 }
929
930                 size = sbc_get_size(cmd, 1);
931                 cmd->t_task_lba = get_unaligned_be32(&cdb[2]);
932
933                 /*
934                  * Follow sbcr26 with WRITE_SAME (10) and check for the existence
935                  * of byte 1 bit 3 UNMAP instead of original reserved field
936                  */
937                 ret = sbc_setup_write_same(cmd, &cdb[1], ops);
938                 if (ret)
939                         return ret;
940                 break;
941         case VERIFY:
942                 size = 0;
943                 cmd->execute_cmd = sbc_emulate_noop;
944                 break;
945         case REZERO_UNIT:
946         case SEEK_6:
947         case SEEK_10:
948                 /*
949                  * There are still clients out there which use these old SCSI-2
950                  * commands. This mainly happens when running VMs with legacy
951                  * guest systems, connected via SCSI command pass-through to
952                  * iSCSI targets. Make them happy and return status GOOD.
953                  */
954                 size = 0;
955                 cmd->execute_cmd = sbc_emulate_noop;
956                 break;
957         default:
958                 ret = spc_parse_cdb(cmd, &size);
959                 if (ret)
960                         return ret;
961         }
962
963         /* reject any command that we don't have a handler for */
964         if (!(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) && !cmd->execute_cmd)
965                 return TCM_UNSUPPORTED_SCSI_OPCODE;
966
967         if (cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
968                 unsigned long long end_lba;
969
970                 if (sectors > dev->dev_attrib.fabric_max_sectors) {
971                         printk_ratelimited(KERN_ERR "SCSI OP %02xh with too"
972                                 " big sectors %u exceeds fabric_max_sectors:"
973                                 " %u\n", cdb[0], sectors,
974                                 dev->dev_attrib.fabric_max_sectors);
975                         return TCM_INVALID_CDB_FIELD;
976                 }
977                 if (sectors > dev->dev_attrib.hw_max_sectors) {
978                         printk_ratelimited(KERN_ERR "SCSI OP %02xh with too"
979                                 " big sectors %u exceeds backend hw_max_sectors:"
980                                 " %u\n", cdb[0], sectors,
981                                 dev->dev_attrib.hw_max_sectors);
982                         return TCM_INVALID_CDB_FIELD;
983                 }
984
985                 end_lba = dev->transport->get_blocks(dev) + 1;
986                 if (cmd->t_task_lba + sectors > end_lba) {
987                         pr_err("cmd exceeds last lba %llu "
988                                 "(lba %llu, sectors %u)\n",
989                                 end_lba, cmd->t_task_lba, sectors);
990                         return TCM_ADDRESS_OUT_OF_RANGE;
991                 }
992
993                 if (!(cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE))
994                         size = sbc_get_size(cmd, sectors);
995         }
996
997         return target_cmd_size_check(cmd, size);
998 }
999 EXPORT_SYMBOL(sbc_parse_cdb);
1000
1001 u32 sbc_get_device_type(struct se_device *dev)
1002 {
1003         return TYPE_DISK;
1004 }
1005 EXPORT_SYMBOL(sbc_get_device_type);
1006
1007 sense_reason_t
1008 sbc_execute_unmap(struct se_cmd *cmd,
1009         sense_reason_t (*do_unmap_fn)(struct se_cmd *, void *,
1010                                       sector_t, sector_t),
1011         void *priv)
1012 {
1013         struct se_device *dev = cmd->se_dev;
1014         unsigned char *buf, *ptr = NULL;
1015         sector_t lba;
1016         int size;
1017         u32 range;
1018         sense_reason_t ret = 0;
1019         int dl, bd_dl;
1020
1021         /* We never set ANC_SUP */
1022         if (cmd->t_task_cdb[1])
1023                 return TCM_INVALID_CDB_FIELD;
1024
1025         if (cmd->data_length == 0) {
1026                 target_complete_cmd(cmd, SAM_STAT_GOOD);
1027                 return 0;
1028         }
1029
1030         if (cmd->data_length < 8) {
1031                 pr_warn("UNMAP parameter list length %u too small\n",
1032                         cmd->data_length);
1033                 return TCM_PARAMETER_LIST_LENGTH_ERROR;
1034         }
1035
1036         buf = transport_kmap_data_sg(cmd);
1037         if (!buf)
1038                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1039
1040         dl = get_unaligned_be16(&buf[0]);
1041         bd_dl = get_unaligned_be16(&buf[2]);
1042
1043         size = cmd->data_length - 8;
1044         if (bd_dl > size)
1045                 pr_warn("UNMAP parameter list length %u too small, ignoring bd_dl %u\n",
1046                         cmd->data_length, bd_dl);
1047         else
1048                 size = bd_dl;
1049
1050         if (size / 16 > dev->dev_attrib.max_unmap_block_desc_count) {
1051                 ret = TCM_INVALID_PARAMETER_LIST;
1052                 goto err;
1053         }
1054
1055         /* First UNMAP block descriptor starts at 8 byte offset */
1056         ptr = &buf[8];
1057         pr_debug("UNMAP: Sub: %s Using dl: %u bd_dl: %u size: %u"
1058                 " ptr: %p\n", dev->transport->name, dl, bd_dl, size, ptr);
1059
1060         while (size >= 16) {
1061                 lba = get_unaligned_be64(&ptr[0]);
1062                 range = get_unaligned_be32(&ptr[8]);
1063                 pr_debug("UNMAP: Using lba: %llu and range: %u\n",
1064                                  (unsigned long long)lba, range);
1065
1066                 if (range > dev->dev_attrib.max_unmap_lba_count) {
1067                         ret = TCM_INVALID_PARAMETER_LIST;
1068                         goto err;
1069                 }
1070
1071                 if (lba + range > dev->transport->get_blocks(dev) + 1) {
1072                         ret = TCM_ADDRESS_OUT_OF_RANGE;
1073                         goto err;
1074                 }
1075
1076                 ret = do_unmap_fn(cmd, priv, lba, range);
1077                 if (ret)
1078                         goto err;
1079
1080                 ptr += 16;
1081                 size -= 16;
1082         }
1083
1084 err:
1085         transport_kunmap_data_sg(cmd);
1086         if (!ret)
1087                 target_complete_cmd(cmd, GOOD);
1088         return ret;
1089 }
1090 EXPORT_SYMBOL(sbc_execute_unmap);
1091
1092 static sense_reason_t
1093 sbc_dif_v1_verify(struct se_device *dev, struct se_dif_v1_tuple *sdt,
1094                   const void *p, sector_t sector, unsigned int ei_lba)
1095 {
1096         int block_size = dev->dev_attrib.block_size;
1097         __be16 csum;
1098
1099         csum = cpu_to_be16(crc_t10dif(p, block_size));
1100
1101         if (sdt->guard_tag != csum) {
1102                 pr_err("DIFv1 checksum failed on sector %llu guard tag 0x%04x"
1103                         " csum 0x%04x\n", (unsigned long long)sector,
1104                         be16_to_cpu(sdt->guard_tag), be16_to_cpu(csum));
1105                 return TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED;
1106         }
1107
1108         if (dev->dev_attrib.pi_prot_type == TARGET_DIF_TYPE1_PROT &&
1109             be32_to_cpu(sdt->ref_tag) != (sector & 0xffffffff)) {
1110                 pr_err("DIFv1 Type 1 reference failed on sector: %llu tag: 0x%08x"
1111                        " sector MSB: 0x%08x\n", (unsigned long long)sector,
1112                        be32_to_cpu(sdt->ref_tag), (u32)(sector & 0xffffffff));
1113                 return TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;
1114         }
1115
1116         if (dev->dev_attrib.pi_prot_type == TARGET_DIF_TYPE2_PROT &&
1117             be32_to_cpu(sdt->ref_tag) != ei_lba) {
1118                 pr_err("DIFv1 Type 2 reference failed on sector: %llu tag: 0x%08x"
1119                        " ei_lba: 0x%08x\n", (unsigned long long)sector,
1120                         be32_to_cpu(sdt->ref_tag), ei_lba);
1121                 return TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;
1122         }
1123
1124         return 0;
1125 }
1126
1127 static void
1128 sbc_dif_copy_prot(struct se_cmd *cmd, unsigned int sectors, bool read,
1129                   struct scatterlist *sg, int sg_off)
1130 {
1131         struct se_device *dev = cmd->se_dev;
1132         struct scatterlist *psg;
1133         void *paddr, *addr;
1134         unsigned int i, len, left;
1135         unsigned int offset = sg_off;
1136
1137         left = sectors * dev->prot_length;
1138
1139         for_each_sg(cmd->t_prot_sg, psg, cmd->t_prot_nents, i) {
1140                 unsigned int psg_len, copied = 0;
1141
1142                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1143                 psg_len = min(left, psg->length);
1144                 while (psg_len) {
1145                         len = min(psg_len, sg->length - offset);
1146                         addr = kmap_atomic(sg_page(sg)) + sg->offset + offset;
1147
1148                         if (read)
1149                                 memcpy(paddr + copied, addr, len);
1150                         else
1151                                 memcpy(addr, paddr + copied, len);
1152
1153                         left -= len;
1154                         offset += len;
1155                         copied += len;
1156                         psg_len -= len;
1157
1158                         if (offset >= sg->length) {
1159                                 sg = sg_next(sg);
1160                                 offset = 0;
1161                         }
1162                         kunmap_atomic(addr);
1163                 }
1164                 kunmap_atomic(paddr);
1165         }
1166 }
1167
1168 sense_reason_t
1169 sbc_dif_verify_write(struct se_cmd *cmd, sector_t start, unsigned int sectors,
1170                      unsigned int ei_lba, struct scatterlist *sg, int sg_off)
1171 {
1172         struct se_device *dev = cmd->se_dev;
1173         struct se_dif_v1_tuple *sdt;
1174         struct scatterlist *dsg, *psg = cmd->t_prot_sg;
1175         sector_t sector = start;
1176         void *daddr, *paddr;
1177         int i, j, offset = 0;
1178         sense_reason_t rc;
1179
1180         for_each_sg(cmd->t_data_sg, dsg, cmd->t_data_nents, i) {
1181                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1182                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1183
1184                 for (j = 0; j < dsg->length; j += dev->dev_attrib.block_size) {
1185
1186                         if (offset >= psg->length) {
1187                                 kunmap_atomic(paddr);
1188                                 psg = sg_next(psg);
1189                                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1190                                 offset = 0;
1191                         }
1192
1193                         sdt = paddr + offset;
1194
1195                         pr_debug("DIF WRITE sector: %llu guard_tag: 0x%04x"
1196                                  " app_tag: 0x%04x ref_tag: %u\n",
1197                                  (unsigned long long)sector, sdt->guard_tag,
1198                                  sdt->app_tag, be32_to_cpu(sdt->ref_tag));
1199
1200                         rc = sbc_dif_v1_verify(dev, sdt, daddr + j, sector,
1201                                                ei_lba);
1202                         if (rc) {
1203                                 kunmap_atomic(paddr);
1204                                 kunmap_atomic(daddr);
1205                                 cmd->bad_sector = sector;
1206                                 return rc;
1207                         }
1208
1209                         sector++;
1210                         ei_lba++;
1211                         offset += sizeof(struct se_dif_v1_tuple);
1212                 }
1213
1214                 kunmap_atomic(paddr);
1215                 kunmap_atomic(daddr);
1216         }
1217         sbc_dif_copy_prot(cmd, sectors, false, sg, sg_off);
1218
1219         return 0;
1220 }
1221 EXPORT_SYMBOL(sbc_dif_verify_write);
1222
1223 sense_reason_t
1224 sbc_dif_verify_read(struct se_cmd *cmd, sector_t start, unsigned int sectors,
1225                     unsigned int ei_lba, struct scatterlist *sg, int sg_off)
1226 {
1227         struct se_device *dev = cmd->se_dev;
1228         struct se_dif_v1_tuple *sdt;
1229         struct scatterlist *dsg, *psg = sg;
1230         sector_t sector = start;
1231         void *daddr, *paddr;
1232         int i, j, offset = sg_off;
1233         sense_reason_t rc;
1234
1235         for_each_sg(cmd->t_data_sg, dsg, cmd->t_data_nents, i) {
1236                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1237                 paddr = kmap_atomic(sg_page(psg)) + sg->offset;
1238
1239                 for (j = 0; j < dsg->length; j += dev->dev_attrib.block_size) {
1240
1241                         if (offset >= psg->length) {
1242                                 kunmap_atomic(paddr);
1243                                 psg = sg_next(psg);
1244                                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1245                                 offset = 0;
1246                         }
1247
1248                         sdt = paddr + offset;
1249
1250                         pr_debug("DIF READ sector: %llu guard_tag: 0x%04x"
1251                                  " app_tag: 0x%04x ref_tag: %u\n",
1252                                  (unsigned long long)sector, sdt->guard_tag,
1253                                  sdt->app_tag, be32_to_cpu(sdt->ref_tag));
1254
1255                         if (sdt->app_tag == cpu_to_be16(0xffff)) {
1256                                 sector++;
1257                                 offset += sizeof(struct se_dif_v1_tuple);
1258                                 continue;
1259                         }
1260
1261                         rc = sbc_dif_v1_verify(dev, sdt, daddr + j, sector,
1262                                                ei_lba);
1263                         if (rc) {
1264                                 kunmap_atomic(paddr);
1265                                 kunmap_atomic(daddr);
1266                                 cmd->bad_sector = sector;
1267                                 return rc;
1268                         }
1269
1270                         sector++;
1271                         ei_lba++;
1272                         offset += sizeof(struct se_dif_v1_tuple);
1273                 }
1274
1275                 kunmap_atomic(paddr);
1276                 kunmap_atomic(daddr);
1277         }
1278         sbc_dif_copy_prot(cmd, sectors, true, sg, sg_off);
1279
1280         return 0;
1281 }
1282 EXPORT_SYMBOL(sbc_dif_verify_read);