drivers/target/target_core_sbc.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * SCSI Block Commands (SBC) parsing and emulation.
   4  *
   5  * (c) Copyright 2002-2013 Datera, Inc.
   6  *
   7  * Nicholas A. Bellinger <[email protected]>
   8  */
   9
  10 #include <linux/kernel.h>
  11 #include <linux/module.h>
  12 #include <linux/ratelimit.h>
  13 #include <linux/crc-t10dif.h>
  14 #include <linux/t10-pi.h>
  15 #include <asm/unaligned.h>
  16 #include <scsi/scsi_proto.h>
  17 #include <scsi/scsi_tcq.h>
  18
  19 #include <target/target_core_base.h>
  20 #include <target/target_core_backend.h>
  21 #include <target/target_core_fabric.h>
  22
  23 #include "target_core_internal.h"
  24 #include "target_core_ua.h"
  25 #include "target_core_alua.h"
  26
  27 static sense_reason_t
  28 sbc_check_prot(struct se_device *, struct se_cmd *, unsigned char, u32, bool);
  29 static sense_reason_t sbc_execute_unmap(struct se_cmd *cmd);
  30
  31 static sense_reason_t
  32 sbc_emulate_readcapacity(struct se_cmd *cmd)
  33 {
  34         struct se_device *dev = cmd->se_dev;
  35         unsigned char *cdb = cmd->t_task_cdb;
  36         unsigned long long blocks_long = dev->transport->get_blocks(dev);
  37         unsigned char *rbuf;
  38         unsigned char buf[8];
  39         u32 blocks;
  40
  41         /*
  42          * SBC-2 says:
  43          *   If the PMI bit is set to zero and the LOGICAL BLOCK
  44          *   ADDRESS field is not set to zero, the device server shall
  45          *   terminate the command with CHECK CONDITION status with
  46          *   the sense key set to ILLEGAL REQUEST and the additional
  47          *   sense code set to INVALID FIELD IN CDB.
  48          *
  49          * In SBC-3, these fields are obsolete, but some SCSI
  50          * compliance tests actually check this, so we might as well
  51          * follow SBC-2.
  52          */
  53         if (!(cdb[8] & 1) && !!(cdb[2] | cdb[3] | cdb[4] | cdb[5]))
  54                 return TCM_INVALID_CDB_FIELD;
  55
  56         if (blocks_long >= 0x00000000ffffffff)
  57                 blocks = 0xffffffff;
  58         else
  59                 blocks = (u32)blocks_long;
  60
  61         put_unaligned_be32(blocks, &buf[0]);
  62         put_unaligned_be32(dev->dev_attrib.block_size, &buf[4]);
  63
  64         rbuf = transport_kmap_data_sg(cmd);
  65         if (rbuf) {
  66                 memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length));
  67                 transport_kunmap_data_sg(cmd);
  68         }
  69
  70         target_complete_cmd_with_length(cmd, SAM_STAT_GOOD, 8);
  71         return 0;
  72 }
  73
  74 static sense_reason_t
  75 sbc_emulate_readcapacity_16(struct se_cmd *cmd)
  76 {
  77         struct se_device *dev = cmd->se_dev;
  78         struct se_session *sess = cmd->se_sess;
  79         int pi_prot_type = dev->dev_attrib.pi_prot_type;
  80
  81         unsigned char *rbuf;
  82         unsigned char buf[32];
  83         unsigned long long blocks = dev->transport->get_blocks(dev);
  84
  85         memset(buf, 0, sizeof(buf));
  86         put_unaligned_be64(blocks, &buf[0]);
  87         put_unaligned_be32(dev->dev_attrib.block_size, &buf[8]);
  88         /*
  89          * Set P_TYPE and PROT_EN bits for DIF support
  90          */
  91         if (sess->sup_prot_ops & (TARGET_PROT_DIN_PASS | TARGET_PROT_DOUT_PASS)) {
  92                 /*
  93                  * Only override a device's pi_prot_type if no T10-PI is
  94                  * available, and sess_prot_type has been explicitly enabled.
  95                  */
  96                 if (!pi_prot_type)
  97                         pi_prot_type = sess->sess_prot_type;
  98
  99                 if (pi_prot_type)
 100                         buf[12] = (pi_prot_type - 1) << 1 | 0x1;
 101         }
 102
 103         if (dev->transport->get_lbppbe)
 104                 buf[13] = dev->transport->get_lbppbe(dev) & 0x0f;
 105
 106         if (dev->transport->get_alignment_offset_lbas) {
 107                 u16 lalba = dev->transport->get_alignment_offset_lbas(dev);
 108
 109                 put_unaligned_be16(lalba, &buf[14]);
 110         }
 111
 112         /*
 113          * Set Thin Provisioning Enable bit following sbc3r22 in section
 114          * READ CAPACITY (16) byte 14 if emulate_tpu or emulate_tpws is enabled.
 115          */
 116         if (dev->dev_attrib.emulate_tpu || dev->dev_attrib.emulate_tpws) {
 117                 buf[14] |= 0x80;
 118
 119                 /*
 120                  * LBPRZ signifies that zeroes will be read back from an LBA after
 121                  * an UNMAP or WRITE SAME w/ unmap bit (sbc3r36 5.16.2)
 122                  */
 123                 if (dev->dev_attrib.unmap_zeroes_data)
 124                         buf[14] |= 0x40;
 125         }
 126
 127         rbuf = transport_kmap_data_sg(cmd);
 128         if (rbuf) {
 129                 memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length));
 130                 transport_kunmap_data_sg(cmd);
 131         }
 132
 133         target_complete_cmd_with_length(cmd, SAM_STAT_GOOD, 32);
 134         return 0;
 135 }
 136
 137 static sense_reason_t
 138 sbc_emulate_startstop(struct se_cmd *cmd)
 139 {
 140         unsigned char *cdb = cmd->t_task_cdb;
 141
 142         /*
 143          * See sbc3r36 section 5.25
 144          * Immediate bit should be set since there is nothing to complete
 145          * POWER CONDITION MODIFIER 0h
 146          */
 147         if (!(cdb[1] & 1) || cdb[2] || cdb[3])
 148                 return TCM_INVALID_CDB_FIELD;
 149
 150         /*
 151          * See sbc3r36 section 5.25
 152          * POWER CONDITION 0h START_VALID - process START and LOEJ
 153          */
 154         if (cdb[4] >> 4 & 0xf)
 155                 return TCM_INVALID_CDB_FIELD;
 156
 157         /*
 158          * See sbc3r36 section 5.25
 159          * LOEJ 0h - nothing to load or unload
 160          * START 1h - we are ready
 161          */
 162         if (!(cdb[4] & 1) || (cdb[4] & 2) || (cdb[4] & 4))
 163                 return TCM_INVALID_CDB_FIELD;
 164
 165         target_complete_cmd(cmd, SAM_STAT_GOOD);
 166         return 0;
 167 }
 168
 169 sector_t sbc_get_write_same_sectors(struct se_cmd *cmd)
 170 {
 171         u32 num_blocks;
 172
 173         if (cmd->t_task_cdb[0] == WRITE_SAME)
 174                 num_blocks = get_unaligned_be16(&cmd->t_task_cdb[7]);
 175         else if (cmd->t_task_cdb[0] == WRITE_SAME_16)
 176                 num_blocks = get_unaligned_be32(&cmd->t_task_cdb[10]);
 177         else /* WRITE_SAME_32 via VARIABLE_LENGTH_CMD */
 178                 num_blocks = get_unaligned_be32(&cmd->t_task_cdb[28]);
 179
 180         /*
 181          * Use the explicit range when non zero is supplied, otherwise calculate
 182          * the remaining range based on ->get_blocks() - starting LBA.
 183          */
 184         if (num_blocks)
 185                 return num_blocks;
 186
 187         return cmd->se_dev->transport->get_blocks(cmd->se_dev) -
 188                 cmd->t_task_lba + 1;
 189 }
 190 EXPORT_SYMBOL(sbc_get_write_same_sectors);
 191
 192 static sense_reason_t
 193 sbc_execute_write_same_unmap(struct se_cmd *cmd)
 194 {
 195         struct sbc_ops *ops = cmd->protocol_data;
 196         sector_t nolb = sbc_get_write_same_sectors(cmd);
 197         sense_reason_t ret;
 198
 199         if (nolb) {
 200                 ret = ops->execute_unmap(cmd, cmd->t_task_lba, nolb);
 201                 if (ret)
 202                         return ret;
 203         }
 204
 205         target_complete_cmd(cmd, SAM_STAT_GOOD);
 206         return 0;
 207 }
 208
 209 static sense_reason_t
 210 sbc_emulate_noop(struct se_cmd *cmd)
 211 {
 212         target_complete_cmd(cmd, SAM_STAT_GOOD);
 213         return 0;
 214 }
 215
 216 static inline u32 sbc_get_size(struct se_cmd *cmd, u32 sectors)
 217 {
 218         return cmd->se_dev->dev_attrib.block_size * sectors;
 219 }
 220
 221 static inline u32 transport_get_sectors_6(unsigned char *cdb)
 222 {
 223         /*
 224          * Use 8-bit sector value.  SBC-3 says:
 225          *
 226          *   A TRANSFER LENGTH field set to zero specifies that 256
 227          *   logical blocks shall be written.  Any other value
 228          *   specifies the number of logical blocks that shall be
 229          *   written.
 230          */
 231         return cdb[4] ? : 256;
 232 }
 233
 234 static inline u32 transport_get_sectors_10(unsigned char *cdb)
 235 {
 236         return get_unaligned_be16(&cdb[7]);
 237 }
 238
 239 static inline u32 transport_get_sectors_12(unsigned char *cdb)
 240 {
 241         return get_unaligned_be32(&cdb[6]);
 242 }
 243
 244 static inline u32 transport_get_sectors_16(unsigned char *cdb)
 245 {
 246         return get_unaligned_be32(&cdb[10]);
 247 }
 248
 249 /*
 250  * Used for VARIABLE_LENGTH_CDB WRITE_32 and READ_32 variants
 251  */
 252 static inline u32 transport_get_sectors_32(unsigned char *cdb)
 253 {
 254         return get_unaligned_be32(&cdb[28]);
 255
 256 }
 257
 258 static inline u32 transport_lba_21(unsigned char *cdb)
 259 {
 260         return get_unaligned_be24(&cdb[1]) & 0x1fffff;
 261 }
 262
 263 static inline u32 transport_lba_32(unsigned char *cdb)
 264 {
 265         return get_unaligned_be32(&cdb[2]);
 266 }
 267
 268 static inline unsigned long long transport_lba_64(unsigned char *cdb)
 269 {
 270         return get_unaligned_be64(&cdb[2]);
 271 }
 272
 273 /*
 274  * For VARIABLE_LENGTH_CDB w/ 32 byte extended CDBs
 275  */
 276 static inline unsigned long long transport_lba_64_ext(unsigned char *cdb)
 277 {
 278         return get_unaligned_be64(&cdb[12]);
 279 }
 280
 281 static sense_reason_t
 282 sbc_setup_write_same(struct se_cmd *cmd, unsigned char flags, struct sbc_ops *ops)
 283 {
 284         struct se_device *dev = cmd->se_dev;
 285         sector_t end_lba = dev->transport->get_blocks(dev) + 1;
 286         unsigned int sectors = sbc_get_write_same_sectors(cmd);
 287         sense_reason_t ret;
 288
 289         if ((flags & 0x04) || (flags & 0x02)) {
 290                 pr_err("WRITE_SAME PBDATA and LBDATA"
 291                         " bits not supported for Block Discard"
 292                         " Emulation\n");
 293                 return TCM_UNSUPPORTED_SCSI_OPCODE;
 294         }
 295         if (sectors > cmd->se_dev->dev_attrib.max_write_same_len) {
 296                 pr_warn("WRITE_SAME sectors: %u exceeds max_write_same_len: %u\n",
 297                         sectors, cmd->se_dev->dev_attrib.max_write_same_len);
 298                 return TCM_INVALID_CDB_FIELD;
 299         }
 300         /*
 301          * Sanity check for LBA wrap and request past end of device.
 302          */
 303         if (((cmd->t_task_lba + sectors) < cmd->t_task_lba) ||
 304             ((cmd->t_task_lba + sectors) > end_lba)) {
 305                 pr_err("WRITE_SAME exceeds last lba %llu (lba %llu, sectors %u)\n",
 306                        (unsigned long long)end_lba, cmd->t_task_lba, sectors);
 307                 return TCM_ADDRESS_OUT_OF_RANGE;
 308         }
 309
 310         /* We always have ANC_SUP == 0 so setting ANCHOR is always an error */
 311         if (flags & 0x10) {
 312                 pr_warn("WRITE SAME with ANCHOR not supported\n");
 313                 return TCM_INVALID_CDB_FIELD;
 314         }
 315
 316         if (flags & 0x01) {
 317                 pr_warn("WRITE SAME with NDOB not supported\n");
 318                 return TCM_INVALID_CDB_FIELD;
 319         }
 320
 321         /*
 322          * Special case for WRITE_SAME w/ UNMAP=1 that ends up getting
 323          * translated into block discard requests within backend code.
 324          */
 325         if (flags & 0x08) {
 326                 if (!ops->execute_unmap)
 327                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 328
 329                 if (!dev->dev_attrib.emulate_tpws) {
 330                         pr_err("Got WRITE_SAME w/ UNMAP=1, but backend device"
 331                                " has emulate_tpws disabled\n");
 332                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 333                 }
 334                 cmd->execute_cmd = sbc_execute_write_same_unmap;
 335                 return 0;
 336         }
 337         if (!ops->execute_write_same)
 338                 return TCM_UNSUPPORTED_SCSI_OPCODE;
 339
 340         ret = sbc_check_prot(dev, cmd, flags >> 5, sectors, true);
 341         if (ret)
 342                 return ret;
 343
 344         cmd->execute_cmd = ops->execute_write_same;
 345         return 0;
 346 }
 347
 348 static sense_reason_t
 349 sbc_execute_rw(struct se_cmd *cmd)
 350 {
 351         struct sbc_ops *ops = cmd->protocol_data;
 352
 353         return ops->execute_rw(cmd, cmd->t_data_sg, cmd->t_data_nents,
 354                                cmd->data_direction);
 355 }
 356
 357 static sense_reason_t compare_and_write_post(struct se_cmd *cmd, bool success,
 358                                              int *post_ret)
 359 {
 360         struct se_device *dev = cmd->se_dev;
 361         sense_reason_t ret = TCM_NO_SENSE;
 362
 363         spin_lock_irq(&cmd->t_state_lock);
 364         if (success) {
 365                 *post_ret = 1;
 366
 367                 if (cmd->scsi_status == SAM_STAT_CHECK_CONDITION)
 368                         ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 369         }
 370         spin_unlock_irq(&cmd->t_state_lock);
 371
 372         /*
 373          * Unlock ->caw_sem originally obtained during sbc_compare_and_write()
 374          * before the original READ I/O submission.
 375          */
 376         up(&dev->caw_sem);
 377
 378         return ret;
 379 }
 380
 381 /*
 382  * compare @cmp_len bytes of @read_sgl with @cmp_sgl. On miscompare, fill
 383  * @miscmp_off and return TCM_MISCOMPARE_VERIFY.
 384  */
 385 static sense_reason_t
 386 compare_and_write_do_cmp(struct scatterlist *read_sgl, unsigned int read_nents,
 387                          struct scatterlist *cmp_sgl, unsigned int cmp_nents,
 388                          unsigned int cmp_len, unsigned int *miscmp_off)
 389 {
 390         unsigned char *buf = NULL;
 391         struct scatterlist *sg;
 392         sense_reason_t ret;
 393         unsigned int offset;
 394         size_t rc;
 395         int sg_cnt;
 396
 397         buf = kzalloc(cmp_len, GFP_KERNEL);
 398         if (!buf) {
 399                 ret = TCM_OUT_OF_RESOURCES;
 400                 goto out;
 401         }
 402
 403         rc = sg_copy_to_buffer(cmp_sgl, cmp_nents, buf, cmp_len);
 404         if (!rc) {
 405                 pr_err("sg_copy_to_buffer() failed for compare_and_write\n");
 406                 ret = TCM_OUT_OF_RESOURCES;
 407                 goto out;
 408         }
 409         /*
 410          * Compare SCSI READ payload against verify payload
 411          */
 412         offset = 0;
 413         ret = TCM_NO_SENSE;
 414         for_each_sg(read_sgl, sg, read_nents, sg_cnt) {
 415                 unsigned int len = min(sg->length, cmp_len);
 416                 unsigned char *addr = kmap_atomic(sg_page(sg));
 417
 418                 if (memcmp(addr, buf + offset, len)) {
 419                         unsigned int i;
 420
 421                         for (i = 0; i < len && addr[i] == buf[offset + i]; i++)
 422                                 ;
 423                         *miscmp_off = offset + i;
 424                         pr_warn("Detected MISCOMPARE at offset %u\n",
 425                                 *miscmp_off);
 426                         ret = TCM_MISCOMPARE_VERIFY;
 427                 }
 428                 kunmap_atomic(addr);
 429                 if (ret != TCM_NO_SENSE)
 430                         goto out;
 431
 432                 offset += len;
 433                 cmp_len -= len;
 434                 if (!cmp_len)
 435                         break;
 436         }
 437         pr_debug("COMPARE AND WRITE read data matches compare data\n");
 438 out:
 439         kfree(buf);
 440         return ret;
 441 }
 442
 443 static sense_reason_t compare_and_write_callback(struct se_cmd *cmd, bool success,
 444                                                  int *post_ret)
 445 {
 446         struct se_device *dev = cmd->se_dev;
 447         struct sg_table write_tbl = { };
 448         struct scatterlist *write_sg;
 449         struct sg_mapping_iter m;
 450         unsigned int len;
 451         unsigned int block_size = dev->dev_attrib.block_size;
 452         unsigned int compare_len = (cmd->t_task_nolb * block_size);
 453         unsigned int miscmp_off = 0;
 454         sense_reason_t ret = TCM_NO_SENSE;
 455         int i;
 456
 457         /*
 458          * Handle early failure in transport_generic_request_failure(),
 459          * which will not have taken ->caw_sem yet..
 460          */
 461         if (!success && (!cmd->t_data_sg || !cmd->t_bidi_data_sg))
 462                 return TCM_NO_SENSE;
 463         /*
 464          * Handle special case for zero-length COMPARE_AND_WRITE
 465          */
 466         if (!cmd->data_length)
 467                 goto out;
 468         /*
 469          * Immediately exit + release dev->caw_sem if command has already
 470          * been failed with a non-zero SCSI status.
 471          */
 472         if (cmd->scsi_status) {
 473                 pr_debug("compare_and_write_callback: non zero scsi_status:"
 474                         " 0x%02x\n", cmd->scsi_status);
 475                 *post_ret = 1;
 476                 if (cmd->scsi_status == SAM_STAT_CHECK_CONDITION)
 477                         ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 478                 goto out;
 479         }
 480
 481         ret = compare_and_write_do_cmp(cmd->t_bidi_data_sg,
 482                                        cmd->t_bidi_data_nents,
 483                                        cmd->t_data_sg,
 484                                        cmd->t_data_nents,
 485                                        compare_len,
 486                                        &miscmp_off);
 487         if (ret == TCM_MISCOMPARE_VERIFY) {
 488                 /*
 489                  * SBC-4 r15: 5.3 COMPARE AND WRITE command
 490                  * In the sense data (see 4.18 and SPC-5) the offset from the
 491                  * start of the Data-Out Buffer to the first byte of data that
 492                  * was not equal shall be reported in the INFORMATION field.
 493                  */
 494                 cmd->sense_info = miscmp_off;
 495                 goto out;
 496         } else if (ret)
 497                 goto out;
 498
 499         if (sg_alloc_table(&write_tbl, cmd->t_data_nents, GFP_KERNEL) < 0) {
 500                 pr_err("Unable to allocate compare_and_write sg\n");
 501                 ret = TCM_OUT_OF_RESOURCES;
 502                 goto out;
 503         }
 504         write_sg = write_tbl.sgl;
 505
 506         i = 0;
 507         len = compare_len;
 508         sg_miter_start(&m, cmd->t_data_sg, cmd->t_data_nents, SG_MITER_TO_SG);
 509         /*
 510          * Currently assumes NoLB=1 and SGLs are PAGE_SIZE..
 511          */
 512         while (len) {
 513                 sg_miter_next(&m);
 514
 515                 if (block_size < PAGE_SIZE) {
 516                         sg_set_page(&write_sg[i], m.page, block_size,
 517                                     m.piter.sg->offset + block_size);
 518                 } else {
 519                         sg_miter_next(&m);
 520                         sg_set_page(&write_sg[i], m.page, block_size,
 521                                     m.piter.sg->offset);
 522                 }
 523                 len -= block_size;
 524                 i++;
 525         }
 526         sg_miter_stop(&m);
 527         /*
 528          * Save the original SGL + nents values before updating to new
 529          * assignments, to be released in transport_free_pages() ->
 530          * transport_reset_sgl_orig()
 531          */
 532         cmd->t_data_sg_orig = cmd->t_data_sg;
 533         cmd->t_data_sg = write_sg;
 534         cmd->t_data_nents_orig = cmd->t_data_nents;
 535         cmd->t_data_nents = 1;
 536
 537         cmd->sam_task_attr = TCM_HEAD_TAG;
 538         cmd->transport_complete_callback = compare_and_write_post;
 539         /*
 540          * Now reset ->execute_cmd() to the normal sbc_execute_rw() handler
 541          * for submitting the adjusted SGL to write instance user-data.
 542          */
 543         cmd->execute_cmd = sbc_execute_rw;
 544
 545         spin_lock_irq(&cmd->t_state_lock);
 546         cmd->t_state = TRANSPORT_PROCESSING;
 547         cmd->transport_state |= CMD_T_ACTIVE | CMD_T_SENT;
 548         spin_unlock_irq(&cmd->t_state_lock);
 549
 550         __target_execute_cmd(cmd, false);
 551
 552         return ret;
 553
 554 out:
 555         /*
 556          * In the MISCOMPARE or failure case, unlock ->caw_sem obtained in
 557          * sbc_compare_and_write() before the original READ I/O submission.
 558          */
 559         up(&dev->caw_sem);
 560         sg_free_table(&write_tbl);
 561         return ret;
 562 }
 563
 564 static sense_reason_t
 565 sbc_compare_and_write(struct se_cmd *cmd)
 566 {
 567         struct sbc_ops *ops = cmd->protocol_data;
 568         struct se_device *dev = cmd->se_dev;
 569         sense_reason_t ret;
 570         int rc;
 571         /*
 572          * Submit the READ first for COMPARE_AND_WRITE to perform the
 573          * comparision using SGLs at cmd->t_bidi_data_sg..
 574          */
 575         rc = down_interruptible(&dev->caw_sem);
 576         if (rc != 0) {
 577                 cmd->transport_complete_callback = NULL;
 578                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 579         }
 580         /*
 581          * Reset cmd->data_length to individual block_size in order to not
 582          * confuse backend drivers that depend on this value matching the
 583          * size of the I/O being submitted.
 584          */
 585         cmd->data_length = cmd->t_task_nolb * dev->dev_attrib.block_size;
 586
 587         ret = ops->execute_rw(cmd, cmd->t_bidi_data_sg, cmd->t_bidi_data_nents,
 588                               DMA_FROM_DEVICE);
 589         if (ret) {
 590                 cmd->transport_complete_callback = NULL;
 591                 up(&dev->caw_sem);
 592                 return ret;
 593         }
 594         /*
 595          * Unlock of dev->caw_sem to occur in compare_and_write_callback()
 596          * upon MISCOMPARE, or in compare_and_write_done() upon completion
 597          * of WRITE instance user-data.
 598          */
 599         return TCM_NO_SENSE;
 600 }
 601
 602 static int
 603 sbc_set_prot_op_checks(u8 protect, bool fabric_prot, enum target_prot_type prot_type,
 604                        bool is_write, struct se_cmd *cmd)
 605 {
 606         if (is_write) {
 607                 cmd->prot_op = fabric_prot ? TARGET_PROT_DOUT_STRIP :
 608                                protect ? TARGET_PROT_DOUT_PASS :
 609                                TARGET_PROT_DOUT_INSERT;
 610                 switch (protect) {
 611                 case 0x0:
 612                 case 0x3:
 613                         cmd->prot_checks = 0;
 614                         break;
 615                 case 0x1:
 616                 case 0x5:
 617                         cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
 618                         if (prot_type == TARGET_DIF_TYPE1_PROT)
 619                                 cmd->prot_checks |= TARGET_DIF_CHECK_REFTAG;
 620                         break;
 621                 case 0x2:
 622                         if (prot_type == TARGET_DIF_TYPE1_PROT)
 623                                 cmd->prot_checks = TARGET_DIF_CHECK_REFTAG;
 624                         break;
 625                 case 0x4:
 626                         cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
 627                         break;
 628                 default:
 629                         pr_err("Unsupported protect field %d\n", protect);
 630                         return -EINVAL;
 631                 }
 632         } else {
 633                 cmd->prot_op = fabric_prot ? TARGET_PROT_DIN_INSERT :
 634                                protect ? TARGET_PROT_DIN_PASS :
 635                                TARGET_PROT_DIN_STRIP;
 636                 switch (protect) {
 637                 case 0x0:
 638                 case 0x1:
 639                 case 0x5:
 640                         cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
 641                         if (prot_type == TARGET_DIF_TYPE1_PROT)
 642                                 cmd->prot_checks |= TARGET_DIF_CHECK_REFTAG;
 643                         break;
 644                 case 0x2:
 645                         if (prot_type == TARGET_DIF_TYPE1_PROT)
 646                                 cmd->prot_checks = TARGET_DIF_CHECK_REFTAG;
 647                         break;
 648                 case 0x3:
 649                         cmd->prot_checks = 0;
 650                         break;
 651                 case 0x4:
 652                         cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
 653                         break;
 654                 default:
 655                         pr_err("Unsupported protect field %d\n", protect);
 656                         return -EINVAL;
 657                 }
 658         }
 659
 660         return 0;
 661 }
 662
 663 static sense_reason_t
 664 sbc_check_prot(struct se_device *dev, struct se_cmd *cmd, unsigned char protect,
 665                u32 sectors, bool is_write)
 666 {
 667         int sp_ops = cmd->se_sess->sup_prot_ops;
 668         int pi_prot_type = dev->dev_attrib.pi_prot_type;
 669         bool fabric_prot = false;
 670
 671         if (!cmd->t_prot_sg || !cmd->t_prot_nents) {
 672                 if (unlikely(protect &&
 673                     !dev->dev_attrib.pi_prot_type && !cmd->se_sess->sess_prot_type)) {
 674                         pr_err("CDB contains protect bit, but device + fabric does"
 675                                " not advertise PROTECT=1 feature bit\n");
 676                         return TCM_INVALID_CDB_FIELD;
 677                 }
 678                 if (cmd->prot_pto)
 679                         return TCM_NO_SENSE;
 680         }
 681
 682         switch (dev->dev_attrib.pi_prot_type) {
 683         case TARGET_DIF_TYPE3_PROT:
 684                 cmd->reftag_seed = 0xffffffff;
 685                 break;
 686         case TARGET_DIF_TYPE2_PROT:
 687                 if (protect)
 688                         return TCM_INVALID_CDB_FIELD;
 689
 690                 cmd->reftag_seed = cmd->t_task_lba;
 691                 break;
 692         case TARGET_DIF_TYPE1_PROT:
 693                 cmd->reftag_seed = cmd->t_task_lba;
 694                 break;
 695         case TARGET_DIF_TYPE0_PROT:
 696                 /*
 697                  * See if the fabric supports T10-PI, and the session has been
 698                  * configured to allow export PROTECT=1 feature bit with backend
 699                  * devices that don't support T10-PI.
 700                  */
 701                 fabric_prot = is_write ?
 702                               !!(sp_ops & (TARGET_PROT_DOUT_PASS | TARGET_PROT_DOUT_STRIP)) :
 703                               !!(sp_ops & (TARGET_PROT_DIN_PASS | TARGET_PROT_DIN_INSERT));
 704
 705                 if (fabric_prot && cmd->se_sess->sess_prot_type) {
 706                         pi_prot_type = cmd->se_sess->sess_prot_type;
 707                         break;
 708                 }
 709                 if (!protect)
 710                         return TCM_NO_SENSE;
 711                 fallthrough;
 712         default:
 713                 pr_err("Unable to determine pi_prot_type for CDB: 0x%02x "
 714                        "PROTECT: 0x%02x\n", cmd->t_task_cdb[0], protect);
 715                 return TCM_INVALID_CDB_FIELD;
 716         }
 717
 718         if (sbc_set_prot_op_checks(protect, fabric_prot, pi_prot_type, is_write, cmd))
 719                 return TCM_INVALID_CDB_FIELD;
 720
 721         cmd->prot_type = pi_prot_type;
 722         cmd->prot_length = dev->prot_length * sectors;
 723
 724         /**
 725          * In case protection information exists over the wire
 726          * we modify command data length to describe pure data.
 727          * The actual transfer length is data length + protection
 728          * length
 729          **/
 730         if (protect)
 731                 cmd->data_length = sectors * dev->dev_attrib.block_size;
 732
 733         pr_debug("%s: prot_type=%d, data_length=%d, prot_length=%d "
 734                  "prot_op=%d prot_checks=%d\n",
 735                  __func__, cmd->prot_type, cmd->data_length, cmd->prot_length,
 736                  cmd->prot_op, cmd->prot_checks);
 737
 738         return TCM_NO_SENSE;
 739 }
 740
 741 static int
 742 sbc_check_dpofua(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb)
 743 {
 744         if (cdb[1] & 0x10) {
 745                 /* see explanation in spc_emulate_modesense */
 746                 if (!target_check_fua(dev)) {
 747                         pr_err("Got CDB: 0x%02x with DPO bit set, but device"
 748                                " does not advertise support for DPO\n", cdb[0]);
 749                         return -EINVAL;
 750                 }
 751         }
 752         if (cdb[1] & 0x8) {
 753                 if (!target_check_fua(dev)) {
 754                         pr_err("Got CDB: 0x%02x with FUA bit set, but device"
 755                                " does not advertise support for FUA write\n",
 756                                cdb[0]);
 757                         return -EINVAL;
 758                 }
 759                 cmd->se_cmd_flags |= SCF_FUA;
 760         }
 761         return 0;
 762 }
 763
 764 sense_reason_t
 765 sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
 766 {
 767         struct se_device *dev = cmd->se_dev;
 768         unsigned char *cdb = cmd->t_task_cdb;
 769         unsigned int size;
 770         u32 sectors = 0;
 771         sense_reason_t ret;
 772
 773         cmd->protocol_data = ops;
 774
 775         switch (cdb[0]) {
 776         case READ_6:
 777                 sectors = transport_get_sectors_6(cdb);
 778                 cmd->t_task_lba = transport_lba_21(cdb);
 779                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 780                 cmd->execute_cmd = sbc_execute_rw;
 781                 break;
 782         case READ_10:
 783                 sectors = transport_get_sectors_10(cdb);
 784                 cmd->t_task_lba = transport_lba_32(cdb);
 785
 786                 if (sbc_check_dpofua(dev, cmd, cdb))
 787                         return TCM_INVALID_CDB_FIELD;
 788
 789                 ret = sbc_check_prot(dev, cmd, cdb[1] >> 5, sectors, false);
 790                 if (ret)
 791                         return ret;
 792
 793                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 794                 cmd->execute_cmd = sbc_execute_rw;
 795                 break;
 796         case READ_12:
 797                 sectors = transport_get_sectors_12(cdb);
 798                 cmd->t_task_lba = transport_lba_32(cdb);
 799
 800                 if (sbc_check_dpofua(dev, cmd, cdb))
 801                         return TCM_INVALID_CDB_FIELD;
 802
 803                 ret = sbc_check_prot(dev, cmd, cdb[1] >> 5, sectors, false);
 804                 if (ret)
 805                         return ret;
 806
 807                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 808                 cmd->execute_cmd = sbc_execute_rw;
 809                 break;
 810         case READ_16:
 811                 sectors = transport_get_sectors_16(cdb);
 812                 cmd->t_task_lba = transport_lba_64(cdb);
 813
 814                 if (sbc_check_dpofua(dev, cmd, cdb))
 815                         return TCM_INVALID_CDB_FIELD;
 816
 817                 ret = sbc_check_prot(dev, cmd, cdb[1] >> 5, sectors, false);
 818                 if (ret)
 819                         return ret;
 820
 821                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 822                 cmd->execute_cmd = sbc_execute_rw;
 823                 break;
 824         case WRITE_6:
 825                 sectors = transport_get_sectors_6(cdb);
 826                 cmd->t_task_lba = transport_lba_21(cdb);
 827                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 828                 cmd->execute_cmd = sbc_execute_rw;
 829                 break;
 830         case WRITE_10:
 831         case WRITE_VERIFY:
 832                 sectors = transport_get_sectors_10(cdb);
 833                 cmd->t_task_lba = transport_lba_32(cdb);
 834
 835                 if (sbc_check_dpofua(dev, cmd, cdb))
 836                         return TCM_INVALID_CDB_FIELD;
 837
 838                 ret = sbc_check_prot(dev, cmd, cdb[1] >> 5, sectors, true);
 839                 if (ret)
 840                         return ret;
 841
 842                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 843                 cmd->execute_cmd = sbc_execute_rw;
 844                 break;
 845         case WRITE_12:
 846                 sectors = transport_get_sectors_12(cdb);
 847                 cmd->t_task_lba = transport_lba_32(cdb);
 848
 849                 if (sbc_check_dpofua(dev, cmd, cdb))
 850                         return TCM_INVALID_CDB_FIELD;
 851
 852                 ret = sbc_check_prot(dev, cmd, cdb[1] >> 5, sectors, true);
 853                 if (ret)
 854                         return ret;
 855
 856                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 857                 cmd->execute_cmd = sbc_execute_rw;
 858                 break;
 859         case WRITE_16:
 860         case WRITE_VERIFY_16:
 861                 sectors = transport_get_sectors_16(cdb);
 862                 cmd->t_task_lba = transport_lba_64(cdb);
 863
 864                 if (sbc_check_dpofua(dev, cmd, cdb))
 865                         return TCM_INVALID_CDB_FIELD;
 866
 867                 ret = sbc_check_prot(dev, cmd, cdb[1] >> 5, sectors, true);
 868                 if (ret)
 869                         return ret;
 870
 871                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 872                 cmd->execute_cmd = sbc_execute_rw;
 873                 break;
 874         case VARIABLE_LENGTH_CMD:
 875         {
 876                 u16 service_action = get_unaligned_be16(&cdb[8]);
 877                 switch (service_action) {
 878                 case WRITE_SAME_32:
 879                         sectors = transport_get_sectors_32(cdb);
 880                         if (!sectors) {
 881                                 pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not"
 882                                        " supported\n");
 883                                 return TCM_INVALID_CDB_FIELD;
 884                         }
 885
 886                         size = sbc_get_size(cmd, 1);
 887                         cmd->t_task_lba = get_unaligned_be64(&cdb[12]);
 888
 889                         ret = sbc_setup_write_same(cmd, cdb[10], ops);
 890                         if (ret)
 891                                 return ret;
 892                         break;
 893                 default:
 894                         pr_err("VARIABLE_LENGTH_CMD service action"
 895                                 " 0x%04x not supported\n", service_action);
 896                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 897                 }
 898                 break;
 899         }
 900         case COMPARE_AND_WRITE:
 901                 if (!dev->dev_attrib.emulate_caw) {
 902                         pr_err_ratelimited("se_device %s/%s (vpd_unit_serial %s) reject COMPARE_AND_WRITE\n",
 903                                            dev->se_hba->backend->ops->name,
 904                                            config_item_name(&dev->dev_group.cg_item),
 905                                            dev->t10_wwn.unit_serial);
 906                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 907                 }
 908                 sectors = cdb[13];
 909                 /*
 910                  * Currently enforce COMPARE_AND_WRITE for a single sector
 911                  */
 912                 if (sectors > 1) {
 913                         pr_err("COMPARE_AND_WRITE contains NoLB: %u greater"
 914                                " than 1\n", sectors);
 915                         return TCM_INVALID_CDB_FIELD;
 916                 }
 917                 if (sbc_check_dpofua(dev, cmd, cdb))
 918                         return TCM_INVALID_CDB_FIELD;
 919
 920                 /*
 921                  * Double size because we have two buffers, note that
 922                  * zero is not an error..
 923                  */
 924                 size = 2 * sbc_get_size(cmd, sectors);
 925                 cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
 926                 cmd->t_task_nolb = sectors;
 927                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB | SCF_COMPARE_AND_WRITE;
 928                 cmd->execute_cmd = sbc_compare_and_write;
 929                 cmd->transport_complete_callback = compare_and_write_callback;
 930                 break;
 931         case READ_CAPACITY:
 932                 size = READ_CAP_LEN;
 933                 cmd->execute_cmd = sbc_emulate_readcapacity;
 934                 break;
 935         case SERVICE_ACTION_IN_16:
 936                 switch (cmd->t_task_cdb[1] & 0x1f) {
 937                 case SAI_READ_CAPACITY_16:
 938                         cmd->execute_cmd = sbc_emulate_readcapacity_16;
 939                         break;
 940                 case SAI_REPORT_REFERRALS:
 941                         cmd->execute_cmd = target_emulate_report_referrals;
 942                         break;
 943                 default:
 944                         pr_err("Unsupported SA: 0x%02x\n",
 945                                 cmd->t_task_cdb[1] & 0x1f);
 946                         return TCM_INVALID_CDB_FIELD;
 947                 }
 948                 size = get_unaligned_be32(&cdb[10]);
 949                 break;
 950         case SYNCHRONIZE_CACHE:
 951         case SYNCHRONIZE_CACHE_16:
 952                 if (cdb[0] == SYNCHRONIZE_CACHE) {
 953                         sectors = transport_get_sectors_10(cdb);
 954                         cmd->t_task_lba = transport_lba_32(cdb);
 955                 } else {
 956                         sectors = transport_get_sectors_16(cdb);
 957                         cmd->t_task_lba = transport_lba_64(cdb);
 958                 }
 959                 if (ops->execute_sync_cache) {
 960                         cmd->execute_cmd = ops->execute_sync_cache;
 961                         goto check_lba;
 962                 }
 963                 size = 0;
 964                 cmd->execute_cmd = sbc_emulate_noop;
 965                 break;
 966         case UNMAP:
 967                 if (!ops->execute_unmap)
 968                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 969
 970                 if (!dev->dev_attrib.emulate_tpu) {
 971                         pr_err("Got UNMAP, but backend device has"
 972                                " emulate_tpu disabled\n");
 973                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 974                 }
 975                 size = get_unaligned_be16(&cdb[7]);
 976                 cmd->execute_cmd = sbc_execute_unmap;
 977                 break;
 978         case WRITE_SAME_16:
 979                 sectors = transport_get_sectors_16(cdb);
 980                 if (!sectors) {
 981                         pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
 982                         return TCM_INVALID_CDB_FIELD;
 983                 }
 984
 985                 size = sbc_get_size(cmd, 1);
 986                 cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
 987
 988                 ret = sbc_setup_write_same(cmd, cdb[1], ops);
 989                 if (ret)
 990                         return ret;
 991                 break;
 992         case WRITE_SAME:
 993                 sectors = transport_get_sectors_10(cdb);
 994                 if (!sectors) {
 995                         pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
 996                         return TCM_INVALID_CDB_FIELD;
 997                 }
 998
 999                 size = sbc_get_size(cmd, 1);
1000                 cmd->t_task_lba = get_unaligned_be32(&cdb[2]);
1001
1002                 /*
1003                  * Follow sbcr26 with WRITE_SAME (10) and check for the existence
1004                  * of byte 1 bit 3 UNMAP instead of original reserved field
1005                  */
1006                 ret = sbc_setup_write_same(cmd, cdb[1], ops);
1007                 if (ret)
1008                         return ret;
1009                 break;
1010         case VERIFY:
1011         case VERIFY_16:
1012                 size = 0;
1013                 if (cdb[0] == VERIFY) {
1014                         sectors = transport_get_sectors_10(cdb);
1015                         cmd->t_task_lba = transport_lba_32(cdb);
1016                 } else {
1017                         sectors = transport_get_sectors_16(cdb);
1018                         cmd->t_task_lba = transport_lba_64(cdb);
1019                 }
1020                 cmd->execute_cmd = sbc_emulate_noop;
1021                 goto check_lba;
1022         case REZERO_UNIT:
1023         case SEEK_6:
1024         case SEEK_10:
1025                 /*
1026                  * There are still clients out there which use these old SCSI-2
1027                  * commands. This mainly happens when running VMs with legacy
1028                  * guest systems, connected via SCSI command pass-through to
1029                  * iSCSI targets. Make them happy and return status GOOD.
1030                  */
1031                 size = 0;
1032                 cmd->execute_cmd = sbc_emulate_noop;
1033                 break;
1034         case START_STOP:
1035                 size = 0;
1036                 cmd->execute_cmd = sbc_emulate_startstop;
1037                 break;
1038         default:
1039                 ret = spc_parse_cdb(cmd, &size);
1040                 if (ret)
1041                         return ret;
1042         }
1043
1044         /* reject any command that we don't have a handler for */
1045         if (!cmd->execute_cmd)
1046                 return TCM_UNSUPPORTED_SCSI_OPCODE;
1047
1048         if (cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
1049                 unsigned long long end_lba;
1050 check_lba:
1051                 end_lba = dev->transport->get_blocks(dev) + 1;
1052                 if (((cmd->t_task_lba + sectors) < cmd->t_task_lba) ||
1053                     ((cmd->t_task_lba + sectors) > end_lba)) {
1054                         pr_err("cmd exceeds last lba %llu "
1055                                 "(lba %llu, sectors %u)\n",
1056                                 end_lba, cmd->t_task_lba, sectors);
1057                         return TCM_ADDRESS_OUT_OF_RANGE;
1058                 }
1059
1060                 if (!(cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE))
1061                         size = sbc_get_size(cmd, sectors);
1062         }
1063
1064         return target_cmd_size_check(cmd, size);
1065 }
1066 EXPORT_SYMBOL(sbc_parse_cdb);
1067
1068 u32 sbc_get_device_type(struct se_device *dev)
1069 {
1070         return TYPE_DISK;
1071 }
1072 EXPORT_SYMBOL(sbc_get_device_type);
1073
1074 static sense_reason_t
1075 sbc_execute_unmap(struct se_cmd *cmd)
1076 {
1077         struct sbc_ops *ops = cmd->protocol_data;
1078         struct se_device *dev = cmd->se_dev;
1079         unsigned char *buf, *ptr = NULL;
1080         sector_t lba;
1081         int size;
1082         u32 range;
1083         sense_reason_t ret = 0;
1084         int dl, bd_dl;
1085
1086         /* We never set ANC_SUP */
1087         if (cmd->t_task_cdb[1])
1088                 return TCM_INVALID_CDB_FIELD;
1089
1090         if (cmd->data_length == 0) {
1091                 target_complete_cmd(cmd, SAM_STAT_GOOD);
1092                 return 0;
1093         }
1094
1095         if (cmd->data_length < 8) {
1096                 pr_warn("UNMAP parameter list length %u too small\n",
1097                         cmd->data_length);
1098                 return TCM_PARAMETER_LIST_LENGTH_ERROR;
1099         }
1100
1101         buf = transport_kmap_data_sg(cmd);
1102         if (!buf)
1103                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1104
1105         dl = get_unaligned_be16(&buf[0]);
1106         bd_dl = get_unaligned_be16(&buf[2]);
1107
1108         size = cmd->data_length - 8;
1109         if (bd_dl > size)
1110                 pr_warn("UNMAP parameter list length %u too small, ignoring bd_dl %u\n",
1111                         cmd->data_length, bd_dl);
1112         else
1113                 size = bd_dl;
1114
1115         if (size / 16 > dev->dev_attrib.max_unmap_block_desc_count) {
1116                 ret = TCM_INVALID_PARAMETER_LIST;
1117                 goto err;
1118         }
1119
1120         /* First UNMAP block descriptor starts at 8 byte offset */
1121         ptr = &buf[8];
1122         pr_debug("UNMAP: Sub: %s Using dl: %u bd_dl: %u size: %u"
1123                 " ptr: %p\n", dev->transport->name, dl, bd_dl, size, ptr);
1124
1125         while (size >= 16) {
1126                 lba = get_unaligned_be64(&ptr[0]);
1127                 range = get_unaligned_be32(&ptr[8]);
1128                 pr_debug("UNMAP: Using lba: %llu and range: %u\n",
1129                                  (unsigned long long)lba, range);
1130
1131                 if (range > dev->dev_attrib.max_unmap_lba_count) {
1132                         ret = TCM_INVALID_PARAMETER_LIST;
1133                         goto err;
1134                 }
1135
1136                 if (lba + range > dev->transport->get_blocks(dev) + 1) {
1137                         ret = TCM_ADDRESS_OUT_OF_RANGE;
1138                         goto err;
1139                 }
1140
1141                 if (range) {
1142                         ret = ops->execute_unmap(cmd, lba, range);
1143                         if (ret)
1144                                 goto err;
1145                 }
1146
1147                 ptr += 16;
1148                 size -= 16;
1149         }
1150
1151 err:
1152         transport_kunmap_data_sg(cmd);
1153         if (!ret)
1154                 target_complete_cmd(cmd, SAM_STAT_GOOD);
1155         return ret;
1156 }
1157
1158 void
1159 sbc_dif_generate(struct se_cmd *cmd)
1160 {
1161         struct se_device *dev = cmd->se_dev;
1162         struct t10_pi_tuple *sdt;
1163         struct scatterlist *dsg = cmd->t_data_sg, *psg;
1164         sector_t sector = cmd->t_task_lba;
1165         void *daddr, *paddr;
1166         int i, j, offset = 0;
1167         unsigned int block_size = dev->dev_attrib.block_size;
1168
1169         for_each_sg(cmd->t_prot_sg, psg, cmd->t_prot_nents, i) {
1170                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1171                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1172
1173                 for (j = 0; j < psg->length;
1174                                 j += sizeof(*sdt)) {
1175                         __u16 crc;
1176                         unsigned int avail;
1177
1178                         if (offset >= dsg->length) {
1179                                 offset -= dsg->length;
1180                                 kunmap_atomic(daddr - dsg->offset);
1181                                 dsg = sg_next(dsg);
1182                                 if (!dsg) {
1183                                         kunmap_atomic(paddr - psg->offset);
1184                                         return;
1185                                 }
1186                                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1187                         }
1188
1189                         sdt = paddr + j;
1190                         avail = min(block_size, dsg->length - offset);
1191                         crc = crc_t10dif(daddr + offset, avail);
1192                         if (avail < block_size) {
1193                                 kunmap_atomic(daddr - dsg->offset);
1194                                 dsg = sg_next(dsg);
1195                                 if (!dsg) {
1196                                         kunmap_atomic(paddr - psg->offset);
1197                                         return;
1198                                 }
1199                                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1200                                 offset = block_size - avail;
1201                                 crc = crc_t10dif_update(crc, daddr, offset);
1202                         } else {
1203                                 offset += block_size;
1204                         }
1205
1206                         sdt->guard_tag = cpu_to_be16(crc);
1207                         if (cmd->prot_type == TARGET_DIF_TYPE1_PROT)
1208                                 sdt->ref_tag = cpu_to_be32(sector & 0xffffffff);
1209                         sdt->app_tag = 0;
1210
1211                         pr_debug("DIF %s INSERT sector: %llu guard_tag: 0x%04x"
1212                                  " app_tag: 0x%04x ref_tag: %u\n",
1213                                  (cmd->data_direction == DMA_TO_DEVICE) ?
1214                                  "WRITE" : "READ", (unsigned long long)sector,
1215                                  sdt->guard_tag, sdt->app_tag,
1216                                  be32_to_cpu(sdt->ref_tag));
1217
1218                         sector++;
1219                 }
1220
1221                 kunmap_atomic(daddr - dsg->offset);
1222                 kunmap_atomic(paddr - psg->offset);
1223         }
1224 }
1225
1226 static sense_reason_t
1227 sbc_dif_v1_verify(struct se_cmd *cmd, struct t10_pi_tuple *sdt,
1228                   __u16 crc, sector_t sector, unsigned int ei_lba)
1229 {
1230         __be16 csum;
1231
1232         if (!(cmd->prot_checks & TARGET_DIF_CHECK_GUARD))
1233                 goto check_ref;
1234
1235         csum = cpu_to_be16(crc);
1236
1237         if (sdt->guard_tag != csum) {
1238                 pr_err("DIFv1 checksum failed on sector %llu guard tag 0x%04x"
1239                         " csum 0x%04x\n", (unsigned long long)sector,
1240                         be16_to_cpu(sdt->guard_tag), be16_to_cpu(csum));
1241                 return TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED;
1242         }
1243
1244 check_ref:
1245         if (!(cmd->prot_checks & TARGET_DIF_CHECK_REFTAG))
1246                 return 0;
1247
1248         if (cmd->prot_type == TARGET_DIF_TYPE1_PROT &&
1249             be32_to_cpu(sdt->ref_tag) != (sector & 0xffffffff)) {
1250                 pr_err("DIFv1 Type 1 reference failed on sector: %llu tag: 0x%08x"
1251                        " sector MSB: 0x%08x\n", (unsigned long long)sector,
1252                        be32_to_cpu(sdt->ref_tag), (u32)(sector & 0xffffffff));
1253                 return TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;
1254         }
1255
1256         if (cmd->prot_type == TARGET_DIF_TYPE2_PROT &&
1257             be32_to_cpu(sdt->ref_tag) != ei_lba) {
1258                 pr_err("DIFv1 Type 2 reference failed on sector: %llu tag: 0x%08x"
1259                        " ei_lba: 0x%08x\n", (unsigned long long)sector,
1260                         be32_to_cpu(sdt->ref_tag), ei_lba);
1261                 return TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;
1262         }
1263
1264         return 0;
1265 }
1266
1267 void sbc_dif_copy_prot(struct se_cmd *cmd, unsigned int sectors, bool read,
1268                        struct scatterlist *sg, int sg_off)
1269 {
1270         struct se_device *dev = cmd->se_dev;
1271         struct scatterlist *psg;
1272         void *paddr, *addr;
1273         unsigned int i, len, left;
1274         unsigned int offset = sg_off;
1275
1276         if (!sg)
1277                 return;
1278
1279         left = sectors * dev->prot_length;
1280
1281         for_each_sg(cmd->t_prot_sg, psg, cmd->t_prot_nents, i) {
1282                 unsigned int psg_len, copied = 0;
1283
1284                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1285                 psg_len = min(left, psg->length);
1286                 while (psg_len) {
1287                         len = min(psg_len, sg->length - offset);
1288                         addr = kmap_atomic(sg_page(sg)) + sg->offset + offset;
1289
1290                         if (read)
1291                                 memcpy(paddr + copied, addr, len);
1292                         else
1293                                 memcpy(addr, paddr + copied, len);
1294
1295                         left -= len;
1296                         offset += len;
1297                         copied += len;
1298                         psg_len -= len;
1299
1300                         kunmap_atomic(addr - sg->offset - offset);
1301
1302                         if (offset >= sg->length) {
1303                                 sg = sg_next(sg);
1304                                 offset = 0;
1305                         }
1306                 }
1307                 kunmap_atomic(paddr - psg->offset);
1308         }
1309 }
1310 EXPORT_SYMBOL(sbc_dif_copy_prot);
1311
1312 sense_reason_t
1313 sbc_dif_verify(struct se_cmd *cmd, sector_t start, unsigned int sectors,
1314                unsigned int ei_lba, struct scatterlist *psg, int psg_off)
1315 {
1316         struct se_device *dev = cmd->se_dev;
1317         struct t10_pi_tuple *sdt;
1318         struct scatterlist *dsg = cmd->t_data_sg;
1319         sector_t sector = start;
1320         void *daddr, *paddr;
1321         int i;
1322         sense_reason_t rc;
1323         int dsg_off = 0;
1324         unsigned int block_size = dev->dev_attrib.block_size;
1325
1326         for (; psg && sector < start + sectors; psg = sg_next(psg)) {
1327                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1328                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1329
1330                 for (i = psg_off; i < psg->length &&
1331                                 sector < start + sectors;
1332                                 i += sizeof(*sdt)) {
1333                         __u16 crc;
1334                         unsigned int avail;
1335
1336                         if (dsg_off >= dsg->length) {
1337                                 dsg_off -= dsg->length;
1338                                 kunmap_atomic(daddr - dsg->offset);
1339                                 dsg = sg_next(dsg);
1340                                 if (!dsg) {
1341                                         kunmap_atomic(paddr - psg->offset);
1342                                         return 0;
1343                                 }
1344                                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1345                         }
1346
1347                         sdt = paddr + i;
1348
1349                         pr_debug("DIF READ sector: %llu guard_tag: 0x%04x"
1350                                  " app_tag: 0x%04x ref_tag: %u\n",
1351                                  (unsigned long long)sector, sdt->guard_tag,
1352                                  sdt->app_tag, be32_to_cpu(sdt->ref_tag));
1353
1354                         if (sdt->app_tag == T10_PI_APP_ESCAPE) {
1355                                 dsg_off += block_size;
1356                                 goto next;
1357                         }
1358
1359                         avail = min(block_size, dsg->length - dsg_off);
1360                         crc = crc_t10dif(daddr + dsg_off, avail);
1361                         if (avail < block_size) {
1362                                 kunmap_atomic(daddr - dsg->offset);
1363                                 dsg = sg_next(dsg);
1364                                 if (!dsg) {
1365                                         kunmap_atomic(paddr - psg->offset);
1366                                         return 0;
1367                                 }
1368                                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1369                                 dsg_off = block_size - avail;
1370                                 crc = crc_t10dif_update(crc, daddr, dsg_off);
1371                         } else {
1372                                 dsg_off += block_size;
1373                         }
1374
1375                         rc = sbc_dif_v1_verify(cmd, sdt, crc, sector, ei_lba);
1376                         if (rc) {
1377                                 kunmap_atomic(daddr - dsg->offset);
1378                                 kunmap_atomic(paddr - psg->offset);
1379                                 cmd->sense_info = sector;
1380                                 return rc;
1381                         }
1382 next:
1383                         sector++;
1384                         ei_lba++;
1385                 }
1386
1387                 psg_off = 0;
1388                 kunmap_atomic(daddr - dsg->offset);
1389                 kunmap_atomic(paddr - psg->offset);
1390         }
1391
1392         return 0;
1393 }
1394 EXPORT_SYMBOL(sbc_dif_verify);