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 <nab@kernel.org>
   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 exec_cmd_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 static sense_reason_t
 274 sbc_setup_write_same(struct se_cmd *cmd, unsigned char flags,
 275                      struct exec_cmd_ops *ops)
 276 {
 277         struct se_device *dev = cmd->se_dev;
 278         sector_t end_lba = dev->transport->get_blocks(dev) + 1;
 279         unsigned int sectors = sbc_get_write_same_sectors(cmd);
 280         sense_reason_t ret;
 281
 282         if ((flags & 0x04) || (flags & 0x02)) {
 283                 pr_err("WRITE_SAME PBDATA and LBDATA"
 284                         " bits not supported for Block Discard"
 285                         " Emulation\n");
 286                 return TCM_UNSUPPORTED_SCSI_OPCODE;
 287         }
 288         if (sectors > cmd->se_dev->dev_attrib.max_write_same_len) {
 289                 pr_warn("WRITE_SAME sectors: %u exceeds max_write_same_len: %u\n",
 290                         sectors, cmd->se_dev->dev_attrib.max_write_same_len);
 291                 return TCM_INVALID_CDB_FIELD;
 292         }
 293         /*
 294          * Sanity check for LBA wrap and request past end of device.
 295          */
 296         if (((cmd->t_task_lba + sectors) < cmd->t_task_lba) ||
 297             ((cmd->t_task_lba + sectors) > end_lba)) {
 298                 pr_err("WRITE_SAME exceeds last lba %llu (lba %llu, sectors %u)\n",
 299                        (unsigned long long)end_lba, cmd->t_task_lba, sectors);
 300                 return TCM_ADDRESS_OUT_OF_RANGE;
 301         }
 302
 303         /* We always have ANC_SUP == 0 so setting ANCHOR is always an error */
 304         if (flags & 0x10) {
 305                 pr_warn("WRITE SAME with ANCHOR not supported\n");
 306                 return TCM_INVALID_CDB_FIELD;
 307         }
 308
 309         if (flags & 0x01) {
 310                 pr_warn("WRITE SAME with NDOB not supported\n");
 311                 return TCM_INVALID_CDB_FIELD;
 312         }
 313
 314         /*
 315          * Special case for WRITE_SAME w/ UNMAP=1 that ends up getting
 316          * translated into block discard requests within backend code.
 317          */
 318         if (flags & 0x08) {
 319                 if (!ops->execute_unmap)
 320                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 321
 322                 if (!dev->dev_attrib.emulate_tpws) {
 323                         pr_err("Got WRITE_SAME w/ UNMAP=1, but backend device"
 324                                " has emulate_tpws disabled\n");
 325                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 326                 }
 327                 cmd->execute_cmd = sbc_execute_write_same_unmap;
 328                 return 0;
 329         }
 330         if (!ops->execute_write_same)
 331                 return TCM_UNSUPPORTED_SCSI_OPCODE;
 332
 333         ret = sbc_check_prot(dev, cmd, flags >> 5, sectors, true);
 334         if (ret)
 335                 return ret;
 336
 337         cmd->execute_cmd = ops->execute_write_same;
 338         return 0;
 339 }
 340
 341 static sense_reason_t
 342 sbc_execute_rw(struct se_cmd *cmd)
 343 {
 344         struct exec_cmd_ops *ops = cmd->protocol_data;
 345
 346         return ops->execute_rw(cmd, cmd->t_data_sg, cmd->t_data_nents,
 347                                cmd->data_direction);
 348 }
 349
 350 static sense_reason_t compare_and_write_post(struct se_cmd *cmd, bool success,
 351                                              int *post_ret)
 352 {
 353         struct se_device *dev = cmd->se_dev;
 354         sense_reason_t ret = TCM_NO_SENSE;
 355
 356         spin_lock_irq(&cmd->t_state_lock);
 357         if (success) {
 358                 *post_ret = 1;
 359
 360                 if (cmd->scsi_status == SAM_STAT_CHECK_CONDITION)
 361                         ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 362         }
 363         spin_unlock_irq(&cmd->t_state_lock);
 364
 365         /*
 366          * Unlock ->caw_sem originally obtained during sbc_compare_and_write()
 367          * before the original READ I/O submission.
 368          */
 369         up(&dev->caw_sem);
 370
 371         return ret;
 372 }
 373
 374 /*
 375  * compare @cmp_len bytes of @read_sgl with @cmp_sgl. On miscompare, fill
 376  * @miscmp_off and return TCM_MISCOMPARE_VERIFY.
 377  */
 378 static sense_reason_t
 379 compare_and_write_do_cmp(struct scatterlist *read_sgl, unsigned int read_nents,
 380                          struct scatterlist *cmp_sgl, unsigned int cmp_nents,
 381                          unsigned int cmp_len, unsigned int *miscmp_off)
 382 {
 383         unsigned char *buf = NULL;
 384         struct scatterlist *sg;
 385         sense_reason_t ret;
 386         unsigned int offset;
 387         size_t rc;
 388         int sg_cnt;
 389
 390         buf = kzalloc(cmp_len, GFP_KERNEL);
 391         if (!buf) {
 392                 ret = TCM_OUT_OF_RESOURCES;
 393                 goto out;
 394         }
 395
 396         rc = sg_copy_to_buffer(cmp_sgl, cmp_nents, buf, cmp_len);
 397         if (!rc) {
 398                 pr_err("sg_copy_to_buffer() failed for compare_and_write\n");
 399                 ret = TCM_OUT_OF_RESOURCES;
 400                 goto out;
 401         }
 402         /*
 403          * Compare SCSI READ payload against verify payload
 404          */
 405         offset = 0;
 406         ret = TCM_NO_SENSE;
 407         for_each_sg(read_sgl, sg, read_nents, sg_cnt) {
 408                 unsigned int len = min(sg->length, cmp_len);
 409                 unsigned char *addr = kmap_atomic(sg_page(sg));
 410
 411                 if (memcmp(addr, buf + offset, len)) {
 412                         unsigned int i;
 413
 414                         for (i = 0; i < len && addr[i] == buf[offset + i]; i++)
 415                                 ;
 416                         *miscmp_off = offset + i;
 417                         pr_warn("Detected MISCOMPARE at offset %u\n",
 418                                 *miscmp_off);
 419                         ret = TCM_MISCOMPARE_VERIFY;
 420                 }
 421                 kunmap_atomic(addr);
 422                 if (ret != TCM_NO_SENSE)
 423                         goto out;
 424
 425                 offset += len;
 426                 cmp_len -= len;
 427                 if (!cmp_len)
 428                         break;
 429         }
 430         pr_debug("COMPARE AND WRITE read data matches compare data\n");
 431 out:
 432         kfree(buf);
 433         return ret;
 434 }
 435
 436 static sense_reason_t compare_and_write_callback(struct se_cmd *cmd, bool success,
 437                                                  int *post_ret)
 438 {
 439         struct se_device *dev = cmd->se_dev;
 440         struct sg_table write_tbl = { };
 441         struct scatterlist *write_sg;
 442         struct sg_mapping_iter m;
 443         unsigned int len;
 444         unsigned int block_size = dev->dev_attrib.block_size;
 445         unsigned int compare_len = (cmd->t_task_nolb * block_size);
 446         unsigned int miscmp_off = 0;
 447         sense_reason_t ret = TCM_NO_SENSE;
 448         int i;
 449
 450         if (!success) {
 451                 /*
 452                  * Handle early failure in transport_generic_request_failure(),
 453                  * which will not have taken ->caw_sem yet..
 454                  */
 455                 if (!cmd->t_data_sg || !cmd->t_bidi_data_sg)
 456                         return TCM_NO_SENSE;
 457
 458                 /*
 459                  * The command has been stopped or aborted so
 460                  * we don't have to perform the write operation.
 461                  */
 462                 WARN_ON(!(cmd->transport_state &
 463                         (CMD_T_ABORTED | CMD_T_STOP)));
 464                 goto out;
 465         }
 466         /*
 467          * Handle special case for zero-length COMPARE_AND_WRITE
 468          */
 469         if (!cmd->data_length)
 470                 goto out;
 471         /*
 472          * Immediately exit + release dev->caw_sem if command has already
 473          * been failed with a non-zero SCSI status.
 474          */
 475         if (cmd->scsi_status) {
 476                 pr_debug("compare_and_write_callback: non zero scsi_status:"
 477                         " 0x%02x\n", cmd->scsi_status);
 478                 *post_ret = 1;
 479                 if (cmd->scsi_status == SAM_STAT_CHECK_CONDITION)
 480                         ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 481                 goto out;
 482         }
 483
 484         ret = compare_and_write_do_cmp(cmd->t_bidi_data_sg,
 485                                        cmd->t_bidi_data_nents,
 486                                        cmd->t_data_sg,
 487                                        cmd->t_data_nents,
 488                                        compare_len,
 489                                        &miscmp_off);
 490         if (ret == TCM_MISCOMPARE_VERIFY) {
 491                 /*
 492                  * SBC-4 r15: 5.3 COMPARE AND WRITE command
 493                  * In the sense data (see 4.18 and SPC-5) the offset from the
 494                  * start of the Data-Out Buffer to the first byte of data that
 495                  * was not equal shall be reported in the INFORMATION field.
 496                  */
 497                 cmd->sense_info = miscmp_off;
 498                 goto out;
 499         } else if (ret)
 500                 goto out;
 501
 502         if (sg_alloc_table(&write_tbl, cmd->t_data_nents, GFP_KERNEL) < 0) {
 503                 pr_err("Unable to allocate compare_and_write sg\n");
 504                 ret = TCM_OUT_OF_RESOURCES;
 505                 goto out;
 506         }
 507         write_sg = write_tbl.sgl;
 508
 509         i = 0;
 510         len = compare_len;
 511         sg_miter_start(&m, cmd->t_data_sg, cmd->t_data_nents, SG_MITER_TO_SG);
 512         /*
 513          * Currently assumes NoLB=1 and SGLs are PAGE_SIZE..
 514          */
 515         while (len) {
 516                 sg_miter_next(&m);
 517
 518                 if (block_size < PAGE_SIZE) {
 519                         sg_set_page(&write_sg[i], m.page, block_size,
 520                                     m.piter.sg->offset + block_size);
 521                 } else {
 522                         sg_miter_next(&m);
 523                         sg_set_page(&write_sg[i], m.page, block_size,
 524                                     m.piter.sg->offset);
 525                 }
 526                 len -= block_size;
 527                 i++;
 528         }
 529         sg_miter_stop(&m);
 530         /*
 531          * Save the original SGL + nents values before updating to new
 532          * assignments, to be released in transport_free_pages() ->
 533          * transport_reset_sgl_orig()
 534          */
 535         cmd->t_data_sg_orig = cmd->t_data_sg;
 536         cmd->t_data_sg = write_sg;
 537         cmd->t_data_nents_orig = cmd->t_data_nents;
 538         cmd->t_data_nents = 1;
 539
 540         cmd->sam_task_attr = TCM_HEAD_TAG;
 541         cmd->transport_complete_callback = compare_and_write_post;
 542         /*
 543          * Now reset ->execute_cmd() to the normal sbc_execute_rw() handler
 544          * for submitting the adjusted SGL to write instance user-data.
 545          */
 546         cmd->execute_cmd = sbc_execute_rw;
 547
 548         spin_lock_irq(&cmd->t_state_lock);
 549         cmd->t_state = TRANSPORT_PROCESSING;
 550         cmd->transport_state |= CMD_T_ACTIVE | CMD_T_SENT;
 551         spin_unlock_irq(&cmd->t_state_lock);
 552
 553         __target_execute_cmd(cmd, false);
 554
 555         return ret;
 556
 557 out:
 558         /*
 559          * In the MISCOMPARE or failure case, unlock ->caw_sem obtained in
 560          * sbc_compare_and_write() before the original READ I/O submission.
 561          */
 562         up(&dev->caw_sem);
 563         sg_free_table(&write_tbl);
 564         return ret;
 565 }
 566
 567 static sense_reason_t
 568 sbc_compare_and_write(struct se_cmd *cmd)
 569 {
 570         struct exec_cmd_ops *ops = cmd->protocol_data;
 571         struct se_device *dev = cmd->se_dev;
 572         sense_reason_t ret;
 573         int rc;
 574         /*
 575          * Submit the READ first for COMPARE_AND_WRITE to perform the
 576          * comparision using SGLs at cmd->t_bidi_data_sg..
 577          */
 578         rc = down_interruptible(&dev->caw_sem);
 579         if (rc != 0) {
 580                 cmd->transport_complete_callback = NULL;
 581                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 582         }
 583         /*
 584          * Reset cmd->data_length to individual block_size in order to not
 585          * confuse backend drivers that depend on this value matching the
 586          * size of the I/O being submitted.
 587          */
 588         cmd->data_length = cmd->t_task_nolb * dev->dev_attrib.block_size;
 589
 590         ret = ops->execute_rw(cmd, cmd->t_bidi_data_sg, cmd->t_bidi_data_nents,
 591                               DMA_FROM_DEVICE);
 592         if (ret) {
 593                 cmd->transport_complete_callback = NULL;
 594                 up(&dev->caw_sem);
 595                 return ret;
 596         }
 597         /*
 598          * Unlock of dev->caw_sem to occur in compare_and_write_callback()
 599          * upon MISCOMPARE, or in compare_and_write_done() upon completion
 600          * of WRITE instance user-data.
 601          */
 602         return TCM_NO_SENSE;
 603 }
 604
 605 static int
 606 sbc_set_prot_op_checks(u8 protect, bool fabric_prot, enum target_prot_type prot_type,
 607                        bool is_write, struct se_cmd *cmd)
 608 {
 609         if (is_write) {
 610                 cmd->prot_op = fabric_prot ? TARGET_PROT_DOUT_STRIP :
 611                                protect ? TARGET_PROT_DOUT_PASS :
 612                                TARGET_PROT_DOUT_INSERT;
 613                 switch (protect) {
 614                 case 0x0:
 615                 case 0x3:
 616                         cmd->prot_checks = 0;
 617                         break;
 618                 case 0x1:
 619                 case 0x5:
 620                         cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
 621                         if (prot_type == TARGET_DIF_TYPE1_PROT)
 622                                 cmd->prot_checks |= TARGET_DIF_CHECK_REFTAG;
 623                         break;
 624                 case 0x2:
 625                         if (prot_type == TARGET_DIF_TYPE1_PROT)
 626                                 cmd->prot_checks = TARGET_DIF_CHECK_REFTAG;
 627                         break;
 628                 case 0x4:
 629                         cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
 630                         break;
 631                 default:
 632                         pr_err("Unsupported protect field %d\n", protect);
 633                         return -EINVAL;
 634                 }
 635         } else {
 636                 cmd->prot_op = fabric_prot ? TARGET_PROT_DIN_INSERT :
 637                                protect ? TARGET_PROT_DIN_PASS :
 638                                TARGET_PROT_DIN_STRIP;
 639                 switch (protect) {
 640                 case 0x0:
 641                 case 0x1:
 642                 case 0x5:
 643                         cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
 644                         if (prot_type == TARGET_DIF_TYPE1_PROT)
 645                                 cmd->prot_checks |= TARGET_DIF_CHECK_REFTAG;
 646                         break;
 647                 case 0x2:
 648                         if (prot_type == TARGET_DIF_TYPE1_PROT)
 649                                 cmd->prot_checks = TARGET_DIF_CHECK_REFTAG;
 650                         break;
 651                 case 0x3:
 652                         cmd->prot_checks = 0;
 653                         break;
 654                 case 0x4:
 655                         cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
 656                         break;
 657                 default:
 658                         pr_err("Unsupported protect field %d\n", protect);
 659                         return -EINVAL;
 660                 }
 661         }
 662
 663         return 0;
 664 }
 665
 666 static sense_reason_t
 667 sbc_check_prot(struct se_device *dev, struct se_cmd *cmd, unsigned char protect,
 668                u32 sectors, bool is_write)
 669 {
 670         int sp_ops = cmd->se_sess->sup_prot_ops;
 671         int pi_prot_type = dev->dev_attrib.pi_prot_type;
 672         bool fabric_prot = false;
 673
 674         if (!cmd->t_prot_sg || !cmd->t_prot_nents) {
 675                 if (unlikely(protect &&
 676                     !dev->dev_attrib.pi_prot_type && !cmd->se_sess->sess_prot_type)) {
 677                         pr_err("CDB contains protect bit, but device + fabric does"
 678                                " not advertise PROTECT=1 feature bit\n");
 679                         return TCM_INVALID_CDB_FIELD;
 680                 }
 681                 if (cmd->prot_pto)
 682                         return TCM_NO_SENSE;
 683         }
 684
 685         switch (dev->dev_attrib.pi_prot_type) {
 686         case TARGET_DIF_TYPE3_PROT:
 687                 cmd->reftag_seed = 0xffffffff;
 688                 break;
 689         case TARGET_DIF_TYPE2_PROT:
 690                 if (protect)
 691                         return TCM_INVALID_CDB_FIELD;
 692
 693                 cmd->reftag_seed = cmd->t_task_lba;
 694                 break;
 695         case TARGET_DIF_TYPE1_PROT:
 696                 cmd->reftag_seed = cmd->t_task_lba;
 697                 break;
 698         case TARGET_DIF_TYPE0_PROT:
 699                 /*
 700                  * See if the fabric supports T10-PI, and the session has been
 701                  * configured to allow export PROTECT=1 feature bit with backend
 702                  * devices that don't support T10-PI.
 703                  */
 704                 fabric_prot = is_write ?
 705                               !!(sp_ops & (TARGET_PROT_DOUT_PASS | TARGET_PROT_DOUT_STRIP)) :
 706                               !!(sp_ops & (TARGET_PROT_DIN_PASS | TARGET_PROT_DIN_INSERT));
 707
 708                 if (fabric_prot && cmd->se_sess->sess_prot_type) {
 709                         pi_prot_type = cmd->se_sess->sess_prot_type;
 710                         break;
 711                 }
 712                 if (!protect)
 713                         return TCM_NO_SENSE;
 714                 fallthrough;
 715         default:
 716                 pr_err("Unable to determine pi_prot_type for CDB: 0x%02x "
 717                        "PROTECT: 0x%02x\n", cmd->t_task_cdb[0], protect);
 718                 return TCM_INVALID_CDB_FIELD;
 719         }
 720
 721         if (sbc_set_prot_op_checks(protect, fabric_prot, pi_prot_type, is_write, cmd))
 722                 return TCM_INVALID_CDB_FIELD;
 723
 724         cmd->prot_type = pi_prot_type;
 725         cmd->prot_length = dev->prot_length * sectors;
 726
 727         /**
 728          * In case protection information exists over the wire
 729          * we modify command data length to describe pure data.
 730          * The actual transfer length is data length + protection
 731          * length
 732          **/
 733         if (protect)
 734                 cmd->data_length = sectors * dev->dev_attrib.block_size;
 735
 736         pr_debug("%s: prot_type=%d, data_length=%d, prot_length=%d "
 737                  "prot_op=%d prot_checks=%d\n",
 738                  __func__, cmd->prot_type, cmd->data_length, cmd->prot_length,
 739                  cmd->prot_op, cmd->prot_checks);
 740
 741         return TCM_NO_SENSE;
 742 }
 743
 744 static int
 745 sbc_check_dpofua(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb)
 746 {
 747         if (cdb[1] & 0x10) {
 748                 /* see explanation in spc_emulate_modesense */
 749                 if (!target_check_fua(dev)) {
 750                         pr_err("Got CDB: 0x%02x with DPO bit set, but device"
 751                                " does not advertise support for DPO\n", cdb[0]);
 752                         return -EINVAL;
 753                 }
 754         }
 755         if (cdb[1] & 0x8) {
 756                 if (!target_check_fua(dev)) {
 757                         pr_err("Got CDB: 0x%02x with FUA bit set, but device"
 758                                " does not advertise support for FUA write\n",
 759                                cdb[0]);
 760                         return -EINVAL;
 761                 }
 762                 cmd->se_cmd_flags |= SCF_FUA;
 763         }
 764         return 0;
 765 }
 766
 767 sense_reason_t
 768 sbc_parse_cdb(struct se_cmd *cmd, struct exec_cmd_ops *ops)
 769 {
 770         struct se_device *dev = cmd->se_dev;
 771         unsigned char *cdb = cmd->t_task_cdb;
 772         unsigned int size;
 773         u32 sectors = 0;
 774         sense_reason_t ret;
 775
 776         cmd->protocol_data = ops;
 777
 778         switch (cdb[0]) {
 779         case READ_6:
 780                 sectors = transport_get_sectors_6(cdb);
 781                 cmd->t_task_lba = transport_lba_21(cdb);
 782                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 783                 cmd->execute_cmd = sbc_execute_rw;
 784                 break;
 785         case READ_10:
 786                 sectors = transport_get_sectors_10(cdb);
 787                 cmd->t_task_lba = transport_lba_32(cdb);
 788
 789                 if (sbc_check_dpofua(dev, cmd, cdb))
 790                         return TCM_INVALID_CDB_FIELD;
 791
 792                 ret = sbc_check_prot(dev, cmd, cdb[1] >> 5, sectors, false);
 793                 if (ret)
 794                         return ret;
 795
 796                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 797                 cmd->execute_cmd = sbc_execute_rw;
 798                 break;
 799         case READ_12:
 800                 sectors = transport_get_sectors_12(cdb);
 801                 cmd->t_task_lba = transport_lba_32(cdb);
 802
 803                 if (sbc_check_dpofua(dev, cmd, cdb))
 804                         return TCM_INVALID_CDB_FIELD;
 805
 806                 ret = sbc_check_prot(dev, cmd, cdb[1] >> 5, sectors, false);
 807                 if (ret)
 808                         return ret;
 809
 810                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 811                 cmd->execute_cmd = sbc_execute_rw;
 812                 break;
 813         case READ_16:
 814                 sectors = transport_get_sectors_16(cdb);
 815                 cmd->t_task_lba = transport_lba_64(cdb);
 816
 817                 if (sbc_check_dpofua(dev, cmd, cdb))
 818                         return TCM_INVALID_CDB_FIELD;
 819
 820                 ret = sbc_check_prot(dev, cmd, cdb[1] >> 5, sectors, false);
 821                 if (ret)
 822                         return ret;
 823
 824                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 825                 cmd->execute_cmd = sbc_execute_rw;
 826                 break;
 827         case WRITE_6:
 828                 sectors = transport_get_sectors_6(cdb);
 829                 cmd->t_task_lba = transport_lba_21(cdb);
 830                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 831                 cmd->execute_cmd = sbc_execute_rw;
 832                 break;
 833         case WRITE_10:
 834         case WRITE_VERIFY:
 835                 sectors = transport_get_sectors_10(cdb);
 836                 cmd->t_task_lba = transport_lba_32(cdb);
 837
 838                 if (sbc_check_dpofua(dev, cmd, cdb))
 839                         return TCM_INVALID_CDB_FIELD;
 840
 841                 ret = sbc_check_prot(dev, cmd, cdb[1] >> 5, sectors, true);
 842                 if (ret)
 843                         return ret;
 844
 845                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 846                 cmd->execute_cmd = sbc_execute_rw;
 847                 break;
 848         case WRITE_12:
 849                 sectors = transport_get_sectors_12(cdb);
 850                 cmd->t_task_lba = transport_lba_32(cdb);
 851
 852                 if (sbc_check_dpofua(dev, cmd, cdb))
 853                         return TCM_INVALID_CDB_FIELD;
 854
 855                 ret = sbc_check_prot(dev, cmd, cdb[1] >> 5, sectors, true);
 856                 if (ret)
 857                         return ret;
 858
 859                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 860                 cmd->execute_cmd = sbc_execute_rw;
 861                 break;
 862         case WRITE_16:
 863         case WRITE_VERIFY_16:
 864                 sectors = transport_get_sectors_16(cdb);
 865                 cmd->t_task_lba = transport_lba_64(cdb);
 866
 867                 if (sbc_check_dpofua(dev, cmd, cdb))
 868                         return TCM_INVALID_CDB_FIELD;
 869
 870                 ret = sbc_check_prot(dev, cmd, cdb[1] >> 5, sectors, true);
 871                 if (ret)
 872                         return ret;
 873
 874                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 875                 cmd->execute_cmd = sbc_execute_rw;
 876                 break;
 877         case VARIABLE_LENGTH_CMD:
 878         {
 879                 u16 service_action = get_unaligned_be16(&cdb[8]);
 880                 switch (service_action) {
 881                 case WRITE_SAME_32:
 882                         sectors = transport_get_sectors_32(cdb);
 883                         if (!sectors) {
 884                                 pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not"
 885                                        " supported\n");
 886                                 return TCM_INVALID_CDB_FIELD;
 887                         }
 888
 889                         size = sbc_get_size(cmd, 1);
 890                         cmd->t_task_lba = get_unaligned_be64(&cdb[12]);
 891
 892                         ret = sbc_setup_write_same(cmd, cdb[10], ops);
 893                         if (ret)
 894                                 return ret;
 895                         break;
 896                 default:
 897                         pr_err("VARIABLE_LENGTH_CMD service action"
 898                                 " 0x%04x not supported\n", service_action);
 899                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 900                 }
 901                 break;
 902         }
 903         case COMPARE_AND_WRITE:
 904                 if (!dev->dev_attrib.emulate_caw) {
 905                         pr_err_ratelimited("se_device %s/%s (vpd_unit_serial %s) reject COMPARE_AND_WRITE\n",
 906                                            dev->se_hba->backend->ops->name,
 907                                            config_item_name(&dev->dev_group.cg_item),
 908                                            dev->t10_wwn.unit_serial);
 909                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 910                 }
 911                 sectors = cdb[13];
 912                 /*
 913                  * Currently enforce COMPARE_AND_WRITE for a single sector
 914                  */
 915                 if (sectors > 1) {
 916                         pr_err("COMPARE_AND_WRITE contains NoLB: %u greater"
 917                                " than 1\n", sectors);
 918                         return TCM_INVALID_CDB_FIELD;
 919                 }
 920                 if (sbc_check_dpofua(dev, cmd, cdb))
 921                         return TCM_INVALID_CDB_FIELD;
 922
 923                 /*
 924                  * Double size because we have two buffers, note that
 925                  * zero is not an error..
 926                  */
 927                 size = 2 * sbc_get_size(cmd, sectors);
 928                 cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
 929                 cmd->t_task_nolb = sectors;
 930                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB | SCF_COMPARE_AND_WRITE;
 931                 cmd->execute_cmd = sbc_compare_and_write;
 932                 cmd->transport_complete_callback = compare_and_write_callback;
 933                 break;
 934         case READ_CAPACITY:
 935                 size = READ_CAP_LEN;
 936                 cmd->execute_cmd = sbc_emulate_readcapacity;
 937                 break;
 938         case SERVICE_ACTION_IN_16:
 939                 switch (cmd->t_task_cdb[1] & 0x1f) {
 940                 case SAI_READ_CAPACITY_16:
 941                         cmd->execute_cmd = sbc_emulate_readcapacity_16;
 942                         break;
 943                 case SAI_REPORT_REFERRALS:
 944                         cmd->execute_cmd = target_emulate_report_referrals;
 945                         break;
 946                 default:
 947                         pr_err("Unsupported SA: 0x%02x\n",
 948                                 cmd->t_task_cdb[1] & 0x1f);
 949                         return TCM_INVALID_CDB_FIELD;
 950                 }
 951                 size = get_unaligned_be32(&cdb[10]);
 952                 break;
 953         case SYNCHRONIZE_CACHE:
 954         case SYNCHRONIZE_CACHE_16:
 955                 if (cdb[0] == SYNCHRONIZE_CACHE) {
 956                         sectors = transport_get_sectors_10(cdb);
 957                         cmd->t_task_lba = transport_lba_32(cdb);
 958                 } else {
 959                         sectors = transport_get_sectors_16(cdb);
 960                         cmd->t_task_lba = transport_lba_64(cdb);
 961                 }
 962                 if (ops->execute_sync_cache) {
 963                         cmd->execute_cmd = ops->execute_sync_cache;
 964                         goto check_lba;
 965                 }
 966                 size = 0;
 967                 cmd->execute_cmd = sbc_emulate_noop;
 968                 break;
 969         case UNMAP:
 970                 if (!ops->execute_unmap)
 971                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 972
 973                 if (!dev->dev_attrib.emulate_tpu) {
 974                         pr_err("Got UNMAP, but backend device has"
 975                                " emulate_tpu disabled\n");
 976                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 977                 }
 978                 size = get_unaligned_be16(&cdb[7]);
 979                 cmd->execute_cmd = sbc_execute_unmap;
 980                 break;
 981         case WRITE_SAME_16:
 982                 sectors = transport_get_sectors_16(cdb);
 983                 if (!sectors) {
 984                         pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
 985                         return TCM_INVALID_CDB_FIELD;
 986                 }
 987
 988                 size = sbc_get_size(cmd, 1);
 989                 cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
 990
 991                 ret = sbc_setup_write_same(cmd, cdb[1], ops);
 992                 if (ret)
 993                         return ret;
 994                 break;
 995         case WRITE_SAME:
 996                 sectors = transport_get_sectors_10(cdb);
 997                 if (!sectors) {
 998                         pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
 999                         return TCM_INVALID_CDB_FIELD;
1000                 }
1001
1002                 size = sbc_get_size(cmd, 1);
1003                 cmd->t_task_lba = get_unaligned_be32(&cdb[2]);
1004
1005                 /*
1006                  * Follow sbcr26 with WRITE_SAME (10) and check for the existence
1007                  * of byte 1 bit 3 UNMAP instead of original reserved field
1008                  */
1009                 ret = sbc_setup_write_same(cmd, cdb[1], ops);
1010                 if (ret)
1011                         return ret;
1012                 break;
1013         case VERIFY:
1014         case VERIFY_16:
1015                 size = 0;
1016                 if (cdb[0] == VERIFY) {
1017                         sectors = transport_get_sectors_10(cdb);
1018                         cmd->t_task_lba = transport_lba_32(cdb);
1019                 } else {
1020                         sectors = transport_get_sectors_16(cdb);
1021                         cmd->t_task_lba = transport_lba_64(cdb);
1022                 }
1023                 cmd->execute_cmd = sbc_emulate_noop;
1024                 goto check_lba;
1025         case REZERO_UNIT:
1026         case SEEK_6:
1027         case SEEK_10:
1028                 /*
1029                  * There are still clients out there which use these old SCSI-2
1030                  * commands. This mainly happens when running VMs with legacy
1031                  * guest systems, connected via SCSI command pass-through to
1032                  * iSCSI targets. Make them happy and return status GOOD.
1033                  */
1034                 size = 0;
1035                 cmd->execute_cmd = sbc_emulate_noop;
1036                 break;
1037         case START_STOP:
1038                 size = 0;
1039                 cmd->execute_cmd = sbc_emulate_startstop;
1040                 break;
1041         default:
1042                 ret = spc_parse_cdb(cmd, &size);
1043                 if (ret)
1044                         return ret;
1045         }
1046
1047         /* reject any command that we don't have a handler for */
1048         if (!cmd->execute_cmd)
1049                 return TCM_UNSUPPORTED_SCSI_OPCODE;
1050
1051         if (cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
1052                 unsigned long long end_lba;
1053 check_lba:
1054                 end_lba = dev->transport->get_blocks(dev) + 1;
1055                 if (((cmd->t_task_lba + sectors) < cmd->t_task_lba) ||
1056                     ((cmd->t_task_lba + sectors) > end_lba)) {
1057                         pr_err("cmd exceeds last lba %llu "
1058                                 "(lba %llu, sectors %u)\n",
1059                                 end_lba, cmd->t_task_lba, sectors);
1060                         return TCM_ADDRESS_OUT_OF_RANGE;
1061                 }
1062
1063                 if (!(cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE))
1064                         size = sbc_get_size(cmd, sectors);
1065         }
1066
1067         return target_cmd_size_check(cmd, size);
1068 }
1069 EXPORT_SYMBOL(sbc_parse_cdb);
1070
1071 u32 sbc_get_device_type(struct se_device *dev)
1072 {
1073         return TYPE_DISK;
1074 }
1075 EXPORT_SYMBOL(sbc_get_device_type);
1076
1077 static sense_reason_t
1078 sbc_execute_unmap(struct se_cmd *cmd)
1079 {
1080         struct exec_cmd_ops *ops = cmd->protocol_data;
1081         struct se_device *dev = cmd->se_dev;
1082         unsigned char *buf, *ptr = NULL;
1083         sector_t lba;
1084         int size;
1085         u32 range;
1086         sense_reason_t ret = 0;
1087         int dl, bd_dl;
1088
1089         /* We never set ANC_SUP */
1090         if (cmd->t_task_cdb[1])
1091                 return TCM_INVALID_CDB_FIELD;
1092
1093         if (cmd->data_length == 0) {
1094                 target_complete_cmd(cmd, SAM_STAT_GOOD);
1095                 return 0;
1096         }
1097
1098         if (cmd->data_length < 8) {
1099                 pr_warn("UNMAP parameter list length %u too small\n",
1100                         cmd->data_length);
1101                 return TCM_PARAMETER_LIST_LENGTH_ERROR;
1102         }
1103
1104         buf = transport_kmap_data_sg(cmd);
1105         if (!buf)
1106                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1107
1108         dl = get_unaligned_be16(&buf[0]);
1109         bd_dl = get_unaligned_be16(&buf[2]);
1110
1111         size = cmd->data_length - 8;
1112         if (bd_dl > size)
1113                 pr_warn("UNMAP parameter list length %u too small, ignoring bd_dl %u\n",
1114                         cmd->data_length, bd_dl);
1115         else
1116                 size = bd_dl;
1117
1118         if (size / 16 > dev->dev_attrib.max_unmap_block_desc_count) {
1119                 ret = TCM_INVALID_PARAMETER_LIST;
1120                 goto err;
1121         }
1122
1123         /* First UNMAP block descriptor starts at 8 byte offset */
1124         ptr = &buf[8];
1125         pr_debug("UNMAP: Sub: %s Using dl: %u bd_dl: %u size: %u"
1126                 " ptr: %p\n", dev->transport->name, dl, bd_dl, size, ptr);
1127
1128         while (size >= 16) {
1129                 lba = get_unaligned_be64(&ptr[0]);
1130                 range = get_unaligned_be32(&ptr[8]);
1131                 pr_debug("UNMAP: Using lba: %llu and range: %u\n",
1132                                  (unsigned long long)lba, range);
1133
1134                 if (range > dev->dev_attrib.max_unmap_lba_count) {
1135                         ret = TCM_INVALID_PARAMETER_LIST;
1136                         goto err;
1137                 }
1138
1139                 if (lba + range > dev->transport->get_blocks(dev) + 1) {
1140                         ret = TCM_ADDRESS_OUT_OF_RANGE;
1141                         goto err;
1142                 }
1143
1144                 if (range) {
1145                         ret = ops->execute_unmap(cmd, lba, range);
1146                         if (ret)
1147                                 goto err;
1148                 }
1149
1150                 ptr += 16;
1151                 size -= 16;
1152         }
1153
1154 err:
1155         transport_kunmap_data_sg(cmd);
1156         if (!ret)
1157                 target_complete_cmd(cmd, SAM_STAT_GOOD);
1158         return ret;
1159 }
1160
1161 void
1162 sbc_dif_generate(struct se_cmd *cmd)
1163 {
1164         struct se_device *dev = cmd->se_dev;
1165         struct t10_pi_tuple *sdt;
1166         struct scatterlist *dsg = cmd->t_data_sg, *psg;
1167         sector_t sector = cmd->t_task_lba;
1168         void *daddr, *paddr;
1169         int i, j, offset = 0;
1170         unsigned int block_size = dev->dev_attrib.block_size;
1171
1172         for_each_sg(cmd->t_prot_sg, psg, cmd->t_prot_nents, i) {
1173                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1174                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1175
1176                 for (j = 0; j < psg->length;
1177                                 j += sizeof(*sdt)) {
1178                         __u16 crc;
1179                         unsigned int avail;
1180
1181                         if (offset >= dsg->length) {
1182                                 offset -= dsg->length;
1183                                 kunmap_atomic(daddr - dsg->offset);
1184                                 dsg = sg_next(dsg);
1185                                 if (!dsg) {
1186                                         kunmap_atomic(paddr - psg->offset);
1187                                         return;
1188                                 }
1189                                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1190                         }
1191
1192                         sdt = paddr + j;
1193                         avail = min(block_size, dsg->length - offset);
1194                         crc = crc_t10dif(daddr + offset, avail);
1195                         if (avail < block_size) {
1196                                 kunmap_atomic(daddr - dsg->offset);
1197                                 dsg = sg_next(dsg);
1198                                 if (!dsg) {
1199                                         kunmap_atomic(paddr - psg->offset);
1200                                         return;
1201                                 }
1202                                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1203                                 offset = block_size - avail;
1204                                 crc = crc_t10dif_update(crc, daddr, offset);
1205                         } else {
1206                                 offset += block_size;
1207                         }
1208
1209                         sdt->guard_tag = cpu_to_be16(crc);
1210                         if (cmd->prot_type == TARGET_DIF_TYPE1_PROT)
1211                                 sdt->ref_tag = cpu_to_be32(sector & 0xffffffff);
1212                         sdt->app_tag = 0;
1213
1214                         pr_debug("DIF %s INSERT sector: %llu guard_tag: 0x%04x"
1215                                  " app_tag: 0x%04x ref_tag: %u\n",
1216                                  (cmd->data_direction == DMA_TO_DEVICE) ?
1217                                  "WRITE" : "READ", (unsigned long long)sector,
1218                                  sdt->guard_tag, sdt->app_tag,
1219                                  be32_to_cpu(sdt->ref_tag));
1220
1221                         sector++;
1222                 }
1223
1224                 kunmap_atomic(daddr - dsg->offset);
1225                 kunmap_atomic(paddr - psg->offset);
1226         }
1227 }
1228
1229 static sense_reason_t
1230 sbc_dif_v1_verify(struct se_cmd *cmd, struct t10_pi_tuple *sdt,
1231                   __u16 crc, sector_t sector, unsigned int ei_lba)
1232 {
1233         __be16 csum;
1234
1235         if (!(cmd->prot_checks & TARGET_DIF_CHECK_GUARD))
1236                 goto check_ref;
1237
1238         csum = cpu_to_be16(crc);
1239
1240         if (sdt->guard_tag != csum) {
1241                 pr_err("DIFv1 checksum failed on sector %llu guard tag 0x%04x"
1242                         " csum 0x%04x\n", (unsigned long long)sector,
1243                         be16_to_cpu(sdt->guard_tag), be16_to_cpu(csum));
1244                 return TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED;
1245         }
1246
1247 check_ref:
1248         if (!(cmd->prot_checks & TARGET_DIF_CHECK_REFTAG))
1249                 return 0;
1250
1251         if (cmd->prot_type == TARGET_DIF_TYPE1_PROT &&
1252             be32_to_cpu(sdt->ref_tag) != (sector & 0xffffffff)) {
1253                 pr_err("DIFv1 Type 1 reference failed on sector: %llu tag: 0x%08x"
1254                        " sector MSB: 0x%08x\n", (unsigned long long)sector,
1255                        be32_to_cpu(sdt->ref_tag), (u32)(sector & 0xffffffff));
1256                 return TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;
1257         }
1258
1259         if (cmd->prot_type == TARGET_DIF_TYPE2_PROT &&
1260             be32_to_cpu(sdt->ref_tag) != ei_lba) {
1261                 pr_err("DIFv1 Type 2 reference failed on sector: %llu tag: 0x%08x"
1262                        " ei_lba: 0x%08x\n", (unsigned long long)sector,
1263                         be32_to_cpu(sdt->ref_tag), ei_lba);
1264                 return TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;
1265         }
1266
1267         return 0;
1268 }
1269
1270 void sbc_dif_copy_prot(struct se_cmd *cmd, unsigned int sectors, bool read,
1271                        struct scatterlist *sg, int sg_off)
1272 {
1273         struct se_device *dev = cmd->se_dev;
1274         struct scatterlist *psg;
1275         void *paddr, *addr;
1276         unsigned int i, len, left;
1277         unsigned int offset = sg_off;
1278
1279         if (!sg)
1280                 return;
1281
1282         left = sectors * dev->prot_length;
1283
1284         for_each_sg(cmd->t_prot_sg, psg, cmd->t_prot_nents, i) {
1285                 unsigned int psg_len, copied = 0;
1286
1287                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1288                 psg_len = min(left, psg->length);
1289                 while (psg_len) {
1290                         len = min(psg_len, sg->length - offset);
1291                         addr = kmap_atomic(sg_page(sg)) + sg->offset + offset;
1292
1293                         if (read)
1294                                 memcpy(paddr + copied, addr, len);
1295                         else
1296                                 memcpy(addr, paddr + copied, len);
1297
1298                         left -= len;
1299                         offset += len;
1300                         copied += len;
1301                         psg_len -= len;
1302
1303                         kunmap_atomic(addr - sg->offset - offset);
1304
1305                         if (offset >= sg->length) {
1306                                 sg = sg_next(sg);
1307                                 offset = 0;
1308                         }
1309                 }
1310                 kunmap_atomic(paddr - psg->offset);
1311         }
1312 }
1313 EXPORT_SYMBOL(sbc_dif_copy_prot);
1314
1315 sense_reason_t
1316 sbc_dif_verify(struct se_cmd *cmd, sector_t start, unsigned int sectors,
1317                unsigned int ei_lba, struct scatterlist *psg, int psg_off)
1318 {
1319         struct se_device *dev = cmd->se_dev;
1320         struct t10_pi_tuple *sdt;
1321         struct scatterlist *dsg = cmd->t_data_sg;
1322         sector_t sector = start;
1323         void *daddr, *paddr;
1324         int i;
1325         sense_reason_t rc;
1326         int dsg_off = 0;
1327         unsigned int block_size = dev->dev_attrib.block_size;
1328
1329         for (; psg && sector < start + sectors; psg = sg_next(psg)) {
1330                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1331                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1332
1333                 for (i = psg_off; i < psg->length &&
1334                                 sector < start + sectors;
1335                                 i += sizeof(*sdt)) {
1336                         __u16 crc;
1337                         unsigned int avail;
1338
1339                         if (dsg_off >= dsg->length) {
1340                                 dsg_off -= dsg->length;
1341                                 kunmap_atomic(daddr - dsg->offset);
1342                                 dsg = sg_next(dsg);
1343                                 if (!dsg) {
1344                                         kunmap_atomic(paddr - psg->offset);
1345                                         return 0;
1346                                 }
1347                                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1348                         }
1349
1350                         sdt = paddr + i;
1351
1352                         pr_debug("DIF READ sector: %llu guard_tag: 0x%04x"
1353                                  " app_tag: 0x%04x ref_tag: %u\n",
1354                                  (unsigned long long)sector, sdt->guard_tag,
1355                                  sdt->app_tag, be32_to_cpu(sdt->ref_tag));
1356
1357                         if (sdt->app_tag == T10_PI_APP_ESCAPE) {
1358                                 dsg_off += block_size;
1359                                 goto next;
1360                         }
1361
1362                         avail = min(block_size, dsg->length - dsg_off);
1363                         crc = crc_t10dif(daddr + dsg_off, avail);
1364                         if (avail < block_size) {
1365                                 kunmap_atomic(daddr - dsg->offset);
1366                                 dsg = sg_next(dsg);
1367                                 if (!dsg) {
1368                                         kunmap_atomic(paddr - psg->offset);
1369                                         return 0;
1370                                 }
1371                                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1372                                 dsg_off = block_size - avail;
1373                                 crc = crc_t10dif_update(crc, daddr, dsg_off);
1374                         } else {
1375                                 dsg_off += block_size;
1376                         }
1377
1378                         rc = sbc_dif_v1_verify(cmd, sdt, crc, sector, ei_lba);
1379                         if (rc) {
1380                                 kunmap_atomic(daddr - dsg->offset);
1381                                 kunmap_atomic(paddr - psg->offset);
1382                                 cmd->sense_info = sector;
1383                                 return rc;
1384                         }
1385 next:
1386                         sector++;
1387                         ei_lba++;
1388                 }
1389
1390                 psg_off = 0;
1391                 kunmap_atomic(daddr - dsg->offset);
1392                 kunmap_atomic(paddr - psg->offset);
1393         }
1394
1395         return 0;
1396 }
1397 EXPORT_SYMBOL(sbc_dif_verify);