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 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 xdreadwrite_callback(struct se_cmd *cmd, bool success,
 349                                            int *post_ret)
 350 {
 351         unsigned char *buf, *addr;
 352         struct scatterlist *sg;
 353         unsigned int offset;
 354         sense_reason_t ret = TCM_NO_SENSE;
 355         int i, count;
 356
 357         if (!success)
 358                 return 0;
 359
 360         /*
 361          * From sbc3r22.pdf section 5.48 XDWRITEREAD (10) command
 362          *
 363          * 1) read the specified logical block(s);
 364          * 2) transfer logical blocks from the data-out buffer;
 365          * 3) XOR the logical blocks transferred from the data-out buffer with
 366          *    the logical blocks read, storing the resulting XOR data in a buffer;
 367          * 4) if the DISABLE WRITE bit is set to zero, then write the logical
 368          *    blocks transferred from the data-out buffer; and
 369          * 5) transfer the resulting XOR data to the data-in buffer.
 370          */
 371         buf = kmalloc(cmd->data_length, GFP_KERNEL);
 372         if (!buf) {
 373                 pr_err("Unable to allocate xor_callback buf\n");
 374                 return TCM_OUT_OF_RESOURCES;
 375         }
 376         /*
 377          * Copy the scatterlist WRITE buffer located at cmd->t_data_sg
 378          * into the locally allocated *buf
 379          */
 380         sg_copy_to_buffer(cmd->t_data_sg,
 381                           cmd->t_data_nents,
 382                           buf,
 383                           cmd->data_length);
 384
 385         /*
 386          * Now perform the XOR against the BIDI read memory located at
 387          * cmd->t_mem_bidi_list
 388          */
 389
 390         offset = 0;
 391         for_each_sg(cmd->t_bidi_data_sg, sg, cmd->t_bidi_data_nents, count) {
 392                 addr = kmap_atomic(sg_page(sg));
 393                 if (!addr) {
 394                         ret = TCM_OUT_OF_RESOURCES;
 395                         goto out;
 396                 }
 397
 398                 for (i = 0; i < sg->length; i++)
 399                         *(addr + sg->offset + i) ^= *(buf + offset + i);
 400
 401                 offset += sg->length;
 402                 kunmap_atomic(addr);
 403         }
 404
 405 out:
 406         kfree(buf);
 407         return ret;
 408 }
 409
 410 static sense_reason_t
 411 sbc_execute_rw(struct se_cmd *cmd)
 412 {
 413         struct sbc_ops *ops = cmd->protocol_data;
 414
 415         return ops->execute_rw(cmd, cmd->t_data_sg, cmd->t_data_nents,
 416                                cmd->data_direction);
 417 }
 418
 419 static sense_reason_t compare_and_write_post(struct se_cmd *cmd, bool success,
 420                                              int *post_ret)
 421 {
 422         struct se_device *dev = cmd->se_dev;
 423         sense_reason_t ret = TCM_NO_SENSE;
 424
 425         spin_lock_irq(&cmd->t_state_lock);
 426         if (success) {
 427                 *post_ret = 1;
 428
 429                 if (cmd->scsi_status == SAM_STAT_CHECK_CONDITION)
 430                         ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 431         }
 432         spin_unlock_irq(&cmd->t_state_lock);
 433
 434         /*
 435          * Unlock ->caw_sem originally obtained during sbc_compare_and_write()
 436          * before the original READ I/O submission.
 437          */
 438         up(&dev->caw_sem);
 439
 440         return ret;
 441 }
 442
 443 /*
 444  * compare @cmp_len bytes of @read_sgl with @cmp_sgl. On miscompare, fill
 445  * @miscmp_off and return TCM_MISCOMPARE_VERIFY.
 446  */
 447 static sense_reason_t
 448 compare_and_write_do_cmp(struct scatterlist *read_sgl, unsigned int read_nents,
 449                          struct scatterlist *cmp_sgl, unsigned int cmp_nents,
 450                          unsigned int cmp_len, unsigned int *miscmp_off)
 451 {
 452         unsigned char *buf = NULL;
 453         struct scatterlist *sg;
 454         sense_reason_t ret;
 455         unsigned int offset;
 456         size_t rc;
 457         int sg_cnt;
 458
 459         buf = kzalloc(cmp_len, GFP_KERNEL);
 460         if (!buf) {
 461                 ret = TCM_OUT_OF_RESOURCES;
 462                 goto out;
 463         }
 464
 465         rc = sg_copy_to_buffer(cmp_sgl, cmp_nents, buf, cmp_len);
 466         if (!rc) {
 467                 pr_err("sg_copy_to_buffer() failed for compare_and_write\n");
 468                 ret = TCM_OUT_OF_RESOURCES;
 469                 goto out;
 470         }
 471         /*
 472          * Compare SCSI READ payload against verify payload
 473          */
 474         offset = 0;
 475         ret = TCM_NO_SENSE;
 476         for_each_sg(read_sgl, sg, read_nents, sg_cnt) {
 477                 unsigned int len = min(sg->length, cmp_len);
 478                 unsigned char *addr = kmap_atomic(sg_page(sg));
 479
 480                 if (memcmp(addr, buf + offset, len)) {
 481                         unsigned int i;
 482
 483                         for (i = 0; i < len && addr[i] == buf[offset + i]; i++)
 484                                 ;
 485                         *miscmp_off = offset + i;
 486                         pr_warn("Detected MISCOMPARE at offset %u\n",
 487                                 *miscmp_off);
 488                         ret = TCM_MISCOMPARE_VERIFY;
 489                 }
 490                 kunmap_atomic(addr);
 491                 if (ret != TCM_NO_SENSE)
 492                         goto out;
 493
 494                 offset += len;
 495                 cmp_len -= len;
 496                 if (!cmp_len)
 497                         break;
 498         }
 499         pr_debug("COMPARE AND WRITE read data matches compare data\n");
 500 out:
 501         kfree(buf);
 502         return ret;
 503 }
 504
 505 static sense_reason_t compare_and_write_callback(struct se_cmd *cmd, bool success,
 506                                                  int *post_ret)
 507 {
 508         struct se_device *dev = cmd->se_dev;
 509         struct sg_table write_tbl = { };
 510         struct scatterlist *write_sg;
 511         struct sg_mapping_iter m;
 512         unsigned int len;
 513         unsigned int block_size = dev->dev_attrib.block_size;
 514         unsigned int compare_len = (cmd->t_task_nolb * block_size);
 515         unsigned int miscmp_off = 0;
 516         sense_reason_t ret = TCM_NO_SENSE;
 517         int i;
 518
 519         /*
 520          * Handle early failure in transport_generic_request_failure(),
 521          * which will not have taken ->caw_sem yet..
 522          */
 523         if (!success && (!cmd->t_data_sg || !cmd->t_bidi_data_sg))
 524                 return TCM_NO_SENSE;
 525         /*
 526          * Handle special case for zero-length COMPARE_AND_WRITE
 527          */
 528         if (!cmd->data_length)
 529                 goto out;
 530         /*
 531          * Immediately exit + release dev->caw_sem if command has already
 532          * been failed with a non-zero SCSI status.
 533          */
 534         if (cmd->scsi_status) {
 535                 pr_debug("compare_and_write_callback: non zero scsi_status:"
 536                         " 0x%02x\n", cmd->scsi_status);
 537                 *post_ret = 1;
 538                 if (cmd->scsi_status == SAM_STAT_CHECK_CONDITION)
 539                         ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 540                 goto out;
 541         }
 542
 543         ret = compare_and_write_do_cmp(cmd->t_bidi_data_sg,
 544                                        cmd->t_bidi_data_nents,
 545                                        cmd->t_data_sg,
 546                                        cmd->t_data_nents,
 547                                        compare_len,
 548                                        &miscmp_off);
 549         if (ret == TCM_MISCOMPARE_VERIFY) {
 550                 /*
 551                  * SBC-4 r15: 5.3 COMPARE AND WRITE command
 552                  * In the sense data (see 4.18 and SPC-5) the offset from the
 553                  * start of the Data-Out Buffer to the first byte of data that
 554                  * was not equal shall be reported in the INFORMATION field.
 555                  */
 556                 cmd->sense_info = miscmp_off;
 557                 goto out;
 558         } else if (ret)
 559                 goto out;
 560
 561         if (sg_alloc_table(&write_tbl, cmd->t_data_nents, GFP_KERNEL) < 0) {
 562                 pr_err("Unable to allocate compare_and_write sg\n");
 563                 ret = TCM_OUT_OF_RESOURCES;
 564                 goto out;
 565         }
 566         write_sg = write_tbl.sgl;
 567
 568         i = 0;
 569         len = compare_len;
 570         sg_miter_start(&m, cmd->t_data_sg, cmd->t_data_nents, SG_MITER_TO_SG);
 571         /*
 572          * Currently assumes NoLB=1 and SGLs are PAGE_SIZE..
 573          */
 574         while (len) {
 575                 sg_miter_next(&m);
 576
 577                 if (block_size < PAGE_SIZE) {
 578                         sg_set_page(&write_sg[i], m.page, block_size,
 579                                     m.piter.sg->offset + block_size);
 580                 } else {
 581                         sg_miter_next(&m);
 582                         sg_set_page(&write_sg[i], m.page, block_size,
 583                                     m.piter.sg->offset);
 584                 }
 585                 len -= block_size;
 586                 i++;
 587         }
 588         sg_miter_stop(&m);
 589         /*
 590          * Save the original SGL + nents values before updating to new
 591          * assignments, to be released in transport_free_pages() ->
 592          * transport_reset_sgl_orig()
 593          */
 594         cmd->t_data_sg_orig = cmd->t_data_sg;
 595         cmd->t_data_sg = write_sg;
 596         cmd->t_data_nents_orig = cmd->t_data_nents;
 597         cmd->t_data_nents = 1;
 598
 599         cmd->sam_task_attr = TCM_HEAD_TAG;
 600         cmd->transport_complete_callback = compare_and_write_post;
 601         /*
 602          * Now reset ->execute_cmd() to the normal sbc_execute_rw() handler
 603          * for submitting the adjusted SGL to write instance user-data.
 604          */
 605         cmd->execute_cmd = sbc_execute_rw;
 606
 607         spin_lock_irq(&cmd->t_state_lock);
 608         cmd->t_state = TRANSPORT_PROCESSING;
 609         cmd->transport_state |= CMD_T_ACTIVE | CMD_T_SENT;
 610         spin_unlock_irq(&cmd->t_state_lock);
 611
 612         __target_execute_cmd(cmd, false);
 613
 614         return ret;
 615
 616 out:
 617         /*
 618          * In the MISCOMPARE or failure case, unlock ->caw_sem obtained in
 619          * sbc_compare_and_write() before the original READ I/O submission.
 620          */
 621         up(&dev->caw_sem);
 622         sg_free_table(&write_tbl);
 623         return ret;
 624 }
 625
 626 static sense_reason_t
 627 sbc_compare_and_write(struct se_cmd *cmd)
 628 {
 629         struct sbc_ops *ops = cmd->protocol_data;
 630         struct se_device *dev = cmd->se_dev;
 631         sense_reason_t ret;
 632         int rc;
 633         /*
 634          * Submit the READ first for COMPARE_AND_WRITE to perform the
 635          * comparision using SGLs at cmd->t_bidi_data_sg..
 636          */
 637         rc = down_interruptible(&dev->caw_sem);
 638         if (rc != 0) {
 639                 cmd->transport_complete_callback = NULL;
 640                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 641         }
 642         /*
 643          * Reset cmd->data_length to individual block_size in order to not
 644          * confuse backend drivers that depend on this value matching the
 645          * size of the I/O being submitted.
 646          */
 647         cmd->data_length = cmd->t_task_nolb * dev->dev_attrib.block_size;
 648
 649         ret = ops->execute_rw(cmd, cmd->t_bidi_data_sg, cmd->t_bidi_data_nents,
 650                               DMA_FROM_DEVICE);
 651         if (ret) {
 652                 cmd->transport_complete_callback = NULL;
 653                 up(&dev->caw_sem);
 654                 return ret;
 655         }
 656         /*
 657          * Unlock of dev->caw_sem to occur in compare_and_write_callback()
 658          * upon MISCOMPARE, or in compare_and_write_done() upon completion
 659          * of WRITE instance user-data.
 660          */
 661         return TCM_NO_SENSE;
 662 }
 663
 664 static int
 665 sbc_set_prot_op_checks(u8 protect, bool fabric_prot, enum target_prot_type prot_type,
 666                        bool is_write, struct se_cmd *cmd)
 667 {
 668         if (is_write) {
 669                 cmd->prot_op = fabric_prot ? TARGET_PROT_DOUT_STRIP :
 670                                protect ? TARGET_PROT_DOUT_PASS :
 671                                TARGET_PROT_DOUT_INSERT;
 672                 switch (protect) {
 673                 case 0x0:
 674                 case 0x3:
 675                         cmd->prot_checks = 0;
 676                         break;
 677                 case 0x1:
 678                 case 0x5:
 679                         cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
 680                         if (prot_type == TARGET_DIF_TYPE1_PROT)
 681                                 cmd->prot_checks |= TARGET_DIF_CHECK_REFTAG;
 682                         break;
 683                 case 0x2:
 684                         if (prot_type == TARGET_DIF_TYPE1_PROT)
 685                                 cmd->prot_checks = TARGET_DIF_CHECK_REFTAG;
 686                         break;
 687                 case 0x4:
 688                         cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
 689                         break;
 690                 default:
 691                         pr_err("Unsupported protect field %d\n", protect);
 692                         return -EINVAL;
 693                 }
 694         } else {
 695                 cmd->prot_op = fabric_prot ? TARGET_PROT_DIN_INSERT :
 696                                protect ? TARGET_PROT_DIN_PASS :
 697                                TARGET_PROT_DIN_STRIP;
 698                 switch (protect) {
 699                 case 0x0:
 700                 case 0x1:
 701                 case 0x5:
 702                         cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
 703                         if (prot_type == TARGET_DIF_TYPE1_PROT)
 704                                 cmd->prot_checks |= TARGET_DIF_CHECK_REFTAG;
 705                         break;
 706                 case 0x2:
 707                         if (prot_type == TARGET_DIF_TYPE1_PROT)
 708                                 cmd->prot_checks = TARGET_DIF_CHECK_REFTAG;
 709                         break;
 710                 case 0x3:
 711                         cmd->prot_checks = 0;
 712                         break;
 713                 case 0x4:
 714                         cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
 715                         break;
 716                 default:
 717                         pr_err("Unsupported protect field %d\n", protect);
 718                         return -EINVAL;
 719                 }
 720         }
 721
 722         return 0;
 723 }
 724
 725 static sense_reason_t
 726 sbc_check_prot(struct se_device *dev, struct se_cmd *cmd, unsigned char protect,
 727                u32 sectors, bool is_write)
 728 {
 729         int sp_ops = cmd->se_sess->sup_prot_ops;
 730         int pi_prot_type = dev->dev_attrib.pi_prot_type;
 731         bool fabric_prot = false;
 732
 733         if (!cmd->t_prot_sg || !cmd->t_prot_nents) {
 734                 if (unlikely(protect &&
 735                     !dev->dev_attrib.pi_prot_type && !cmd->se_sess->sess_prot_type)) {
 736                         pr_err("CDB contains protect bit, but device + fabric does"
 737                                " not advertise PROTECT=1 feature bit\n");
 738                         return TCM_INVALID_CDB_FIELD;
 739                 }
 740                 if (cmd->prot_pto)
 741                         return TCM_NO_SENSE;
 742         }
 743
 744         switch (dev->dev_attrib.pi_prot_type) {
 745         case TARGET_DIF_TYPE3_PROT:
 746                 cmd->reftag_seed = 0xffffffff;
 747                 break;
 748         case TARGET_DIF_TYPE2_PROT:
 749                 if (protect)
 750                         return TCM_INVALID_CDB_FIELD;
 751
 752                 cmd->reftag_seed = cmd->t_task_lba;
 753                 break;
 754         case TARGET_DIF_TYPE1_PROT:
 755                 cmd->reftag_seed = cmd->t_task_lba;
 756                 break;
 757         case TARGET_DIF_TYPE0_PROT:
 758                 /*
 759                  * See if the fabric supports T10-PI, and the session has been
 760                  * configured to allow export PROTECT=1 feature bit with backend
 761                  * devices that don't support T10-PI.
 762                  */
 763                 fabric_prot = is_write ?
 764                               !!(sp_ops & (TARGET_PROT_DOUT_PASS | TARGET_PROT_DOUT_STRIP)) :
 765                               !!(sp_ops & (TARGET_PROT_DIN_PASS | TARGET_PROT_DIN_INSERT));
 766
 767                 if (fabric_prot && cmd->se_sess->sess_prot_type) {
 768                         pi_prot_type = cmd->se_sess->sess_prot_type;
 769                         break;
 770                 }
 771                 if (!protect)
 772                         return TCM_NO_SENSE;
 773                 fallthrough;
 774         default:
 775                 pr_err("Unable to determine pi_prot_type for CDB: 0x%02x "
 776                        "PROTECT: 0x%02x\n", cmd->t_task_cdb[0], protect);
 777                 return TCM_INVALID_CDB_FIELD;
 778         }
 779
 780         if (sbc_set_prot_op_checks(protect, fabric_prot, pi_prot_type, is_write, cmd))
 781                 return TCM_INVALID_CDB_FIELD;
 782
 783         cmd->prot_type = pi_prot_type;
 784         cmd->prot_length = dev->prot_length * sectors;
 785
 786         /**
 787          * In case protection information exists over the wire
 788          * we modify command data length to describe pure data.
 789          * The actual transfer length is data length + protection
 790          * length
 791          **/
 792         if (protect)
 793                 cmd->data_length = sectors * dev->dev_attrib.block_size;
 794
 795         pr_debug("%s: prot_type=%d, data_length=%d, prot_length=%d "
 796                  "prot_op=%d prot_checks=%d\n",
 797                  __func__, cmd->prot_type, cmd->data_length, cmd->prot_length,
 798                  cmd->prot_op, cmd->prot_checks);
 799
 800         return TCM_NO_SENSE;
 801 }
 802
 803 static int
 804 sbc_check_dpofua(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb)
 805 {
 806         if (cdb[1] & 0x10) {
 807                 /* see explanation in spc_emulate_modesense */
 808                 if (!target_check_fua(dev)) {
 809                         pr_err("Got CDB: 0x%02x with DPO bit set, but device"
 810                                " does not advertise support for DPO\n", cdb[0]);
 811                         return -EINVAL;
 812                 }
 813         }
 814         if (cdb[1] & 0x8) {
 815                 if (!target_check_fua(dev)) {
 816                         pr_err("Got CDB: 0x%02x with FUA bit set, but device"
 817                                " does not advertise support for FUA write\n",
 818                                cdb[0]);
 819                         return -EINVAL;
 820                 }
 821                 cmd->se_cmd_flags |= SCF_FUA;
 822         }
 823         return 0;
 824 }
 825
 826 sense_reason_t
 827 sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
 828 {
 829         struct se_device *dev = cmd->se_dev;
 830         unsigned char *cdb = cmd->t_task_cdb;
 831         unsigned int size;
 832         u32 sectors = 0;
 833         sense_reason_t ret;
 834
 835         cmd->protocol_data = ops;
 836
 837         switch (cdb[0]) {
 838         case READ_6:
 839                 sectors = transport_get_sectors_6(cdb);
 840                 cmd->t_task_lba = transport_lba_21(cdb);
 841                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 842                 cmd->execute_cmd = sbc_execute_rw;
 843                 break;
 844         case READ_10:
 845                 sectors = transport_get_sectors_10(cdb);
 846                 cmd->t_task_lba = transport_lba_32(cdb);
 847
 848                 if (sbc_check_dpofua(dev, cmd, cdb))
 849                         return TCM_INVALID_CDB_FIELD;
 850
 851                 ret = sbc_check_prot(dev, cmd, cdb[1] >> 5, sectors, false);
 852                 if (ret)
 853                         return ret;
 854
 855                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 856                 cmd->execute_cmd = sbc_execute_rw;
 857                 break;
 858         case READ_12:
 859                 sectors = transport_get_sectors_12(cdb);
 860                 cmd->t_task_lba = transport_lba_32(cdb);
 861
 862                 if (sbc_check_dpofua(dev, cmd, cdb))
 863                         return TCM_INVALID_CDB_FIELD;
 864
 865                 ret = sbc_check_prot(dev, cmd, cdb[1] >> 5, sectors, false);
 866                 if (ret)
 867                         return ret;
 868
 869                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 870                 cmd->execute_cmd = sbc_execute_rw;
 871                 break;
 872         case READ_16:
 873                 sectors = transport_get_sectors_16(cdb);
 874                 cmd->t_task_lba = transport_lba_64(cdb);
 875
 876                 if (sbc_check_dpofua(dev, cmd, cdb))
 877                         return TCM_INVALID_CDB_FIELD;
 878
 879                 ret = sbc_check_prot(dev, cmd, cdb[1] >> 5, sectors, false);
 880                 if (ret)
 881                         return ret;
 882
 883                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 884                 cmd->execute_cmd = sbc_execute_rw;
 885                 break;
 886         case WRITE_6:
 887                 sectors = transport_get_sectors_6(cdb);
 888                 cmd->t_task_lba = transport_lba_21(cdb);
 889                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 890                 cmd->execute_cmd = sbc_execute_rw;
 891                 break;
 892         case WRITE_10:
 893         case WRITE_VERIFY:
 894                 sectors = transport_get_sectors_10(cdb);
 895                 cmd->t_task_lba = transport_lba_32(cdb);
 896
 897                 if (sbc_check_dpofua(dev, cmd, cdb))
 898                         return TCM_INVALID_CDB_FIELD;
 899
 900                 ret = sbc_check_prot(dev, cmd, cdb[1] >> 5, sectors, true);
 901                 if (ret)
 902                         return ret;
 903
 904                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 905                 cmd->execute_cmd = sbc_execute_rw;
 906                 break;
 907         case WRITE_12:
 908                 sectors = transport_get_sectors_12(cdb);
 909                 cmd->t_task_lba = transport_lba_32(cdb);
 910
 911                 if (sbc_check_dpofua(dev, cmd, cdb))
 912                         return TCM_INVALID_CDB_FIELD;
 913
 914                 ret = sbc_check_prot(dev, cmd, cdb[1] >> 5, sectors, true);
 915                 if (ret)
 916                         return ret;
 917
 918                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 919                 cmd->execute_cmd = sbc_execute_rw;
 920                 break;
 921         case WRITE_16:
 922         case WRITE_VERIFY_16:
 923                 sectors = transport_get_sectors_16(cdb);
 924                 cmd->t_task_lba = transport_lba_64(cdb);
 925
 926                 if (sbc_check_dpofua(dev, cmd, cdb))
 927                         return TCM_INVALID_CDB_FIELD;
 928
 929                 ret = sbc_check_prot(dev, cmd, cdb[1] >> 5, sectors, true);
 930                 if (ret)
 931                         return ret;
 932
 933                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 934                 cmd->execute_cmd = sbc_execute_rw;
 935                 break;
 936         case XDWRITEREAD_10:
 937                 if (cmd->data_direction != DMA_TO_DEVICE ||
 938                     !(cmd->se_cmd_flags & SCF_BIDI))
 939                         return TCM_INVALID_CDB_FIELD;
 940                 sectors = transport_get_sectors_10(cdb);
 941
 942                 if (sbc_check_dpofua(dev, cmd, cdb))
 943                         return TCM_INVALID_CDB_FIELD;
 944
 945                 cmd->t_task_lba = transport_lba_32(cdb);
 946                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 947
 948                 /*
 949                  * Setup BIDI XOR callback to be run after I/O completion.
 950                  */
 951                 cmd->execute_cmd = sbc_execute_rw;
 952                 cmd->transport_complete_callback = &xdreadwrite_callback;
 953                 break;
 954         case VARIABLE_LENGTH_CMD:
 955         {
 956                 u16 service_action = get_unaligned_be16(&cdb[8]);
 957                 switch (service_action) {
 958                 case XDWRITEREAD_32:
 959                         sectors = transport_get_sectors_32(cdb);
 960
 961                         if (sbc_check_dpofua(dev, cmd, cdb))
 962                                 return TCM_INVALID_CDB_FIELD;
 963                         /*
 964                          * Use WRITE_32 and READ_32 opcodes for the emulated
 965                          * XDWRITE_READ_32 logic.
 966                          */
 967                         cmd->t_task_lba = transport_lba_64_ext(cdb);
 968                         cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 969
 970                         /*
 971                          * Setup BIDI XOR callback to be run during after I/O
 972                          * completion.
 973                          */
 974                         cmd->execute_cmd = sbc_execute_rw;
 975                         cmd->transport_complete_callback = &xdreadwrite_callback;
 976                         break;
 977                 case WRITE_SAME_32:
 978                         sectors = transport_get_sectors_32(cdb);
 979                         if (!sectors) {
 980                                 pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not"
 981                                        " 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[12]);
 987
 988                         ret = sbc_setup_write_same(cmd, cdb[10], ops);
 989                         if (ret)
 990                                 return ret;
 991                         break;
 992                 default:
 993                         pr_err("VARIABLE_LENGTH_CMD service action"
 994                                 " 0x%04x not supported\n", service_action);
 995                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 996                 }
 997                 break;
 998         }
 999         case COMPARE_AND_WRITE:
1000                 if (!dev->dev_attrib.emulate_caw) {
1001                         pr_err_ratelimited("se_device %s/%s (vpd_unit_serial %s) reject COMPARE_AND_WRITE\n",
1002                                            dev->se_hba->backend->ops->name,
1003                                            config_item_name(&dev->dev_group.cg_item),
1004                                            dev->t10_wwn.unit_serial);
1005                         return TCM_UNSUPPORTED_SCSI_OPCODE;
1006                 }
1007                 sectors = cdb[13];
1008                 /*
1009                  * Currently enforce COMPARE_AND_WRITE for a single sector
1010                  */
1011                 if (sectors > 1) {
1012                         pr_err("COMPARE_AND_WRITE contains NoLB: %u greater"
1013                                " than 1\n", sectors);
1014                         return TCM_INVALID_CDB_FIELD;
1015                 }
1016                 if (sbc_check_dpofua(dev, cmd, cdb))
1017                         return TCM_INVALID_CDB_FIELD;
1018
1019                 /*
1020                  * Double size because we have two buffers, note that
1021                  * zero is not an error..
1022                  */
1023                 size = 2 * sbc_get_size(cmd, sectors);
1024                 cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
1025                 cmd->t_task_nolb = sectors;
1026                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB | SCF_COMPARE_AND_WRITE;
1027                 cmd->execute_cmd = sbc_compare_and_write;
1028                 cmd->transport_complete_callback = compare_and_write_callback;
1029                 break;
1030         case READ_CAPACITY:
1031                 size = READ_CAP_LEN;
1032                 cmd->execute_cmd = sbc_emulate_readcapacity;
1033                 break;
1034         case SERVICE_ACTION_IN_16:
1035                 switch (cmd->t_task_cdb[1] & 0x1f) {
1036                 case SAI_READ_CAPACITY_16:
1037                         cmd->execute_cmd = sbc_emulate_readcapacity_16;
1038                         break;
1039                 case SAI_REPORT_REFERRALS:
1040                         cmd->execute_cmd = target_emulate_report_referrals;
1041                         break;
1042                 default:
1043                         pr_err("Unsupported SA: 0x%02x\n",
1044                                 cmd->t_task_cdb[1] & 0x1f);
1045                         return TCM_INVALID_CDB_FIELD;
1046                 }
1047                 size = get_unaligned_be32(&cdb[10]);
1048                 break;
1049         case SYNCHRONIZE_CACHE:
1050         case SYNCHRONIZE_CACHE_16:
1051                 if (cdb[0] == SYNCHRONIZE_CACHE) {
1052                         sectors = transport_get_sectors_10(cdb);
1053                         cmd->t_task_lba = transport_lba_32(cdb);
1054                 } else {
1055                         sectors = transport_get_sectors_16(cdb);
1056                         cmd->t_task_lba = transport_lba_64(cdb);
1057                 }
1058                 if (ops->execute_sync_cache) {
1059                         cmd->execute_cmd = ops->execute_sync_cache;
1060                         goto check_lba;
1061                 }
1062                 size = 0;
1063                 cmd->execute_cmd = sbc_emulate_noop;
1064                 break;
1065         case UNMAP:
1066                 if (!ops->execute_unmap)
1067                         return TCM_UNSUPPORTED_SCSI_OPCODE;
1068
1069                 if (!dev->dev_attrib.emulate_tpu) {
1070                         pr_err("Got UNMAP, but backend device has"
1071                                " emulate_tpu disabled\n");
1072                         return TCM_UNSUPPORTED_SCSI_OPCODE;
1073                 }
1074                 size = get_unaligned_be16(&cdb[7]);
1075                 cmd->execute_cmd = sbc_execute_unmap;
1076                 break;
1077         case WRITE_SAME_16:
1078                 sectors = transport_get_sectors_16(cdb);
1079                 if (!sectors) {
1080                         pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
1081                         return TCM_INVALID_CDB_FIELD;
1082                 }
1083
1084                 size = sbc_get_size(cmd, 1);
1085                 cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
1086
1087                 ret = sbc_setup_write_same(cmd, cdb[1], ops);
1088                 if (ret)
1089                         return ret;
1090                 break;
1091         case WRITE_SAME:
1092                 sectors = transport_get_sectors_10(cdb);
1093                 if (!sectors) {
1094                         pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
1095                         return TCM_INVALID_CDB_FIELD;
1096                 }
1097
1098                 size = sbc_get_size(cmd, 1);
1099                 cmd->t_task_lba = get_unaligned_be32(&cdb[2]);
1100
1101                 /*
1102                  * Follow sbcr26 with WRITE_SAME (10) and check for the existence
1103                  * of byte 1 bit 3 UNMAP instead of original reserved field
1104                  */
1105                 ret = sbc_setup_write_same(cmd, cdb[1], ops);
1106                 if (ret)
1107                         return ret;
1108                 break;
1109         case VERIFY:
1110         case VERIFY_16:
1111                 size = 0;
1112                 if (cdb[0] == VERIFY) {
1113                         sectors = transport_get_sectors_10(cdb);
1114                         cmd->t_task_lba = transport_lba_32(cdb);
1115                 } else {
1116                         sectors = transport_get_sectors_16(cdb);
1117                         cmd->t_task_lba = transport_lba_64(cdb);
1118                 }
1119                 cmd->execute_cmd = sbc_emulate_noop;
1120                 goto check_lba;
1121         case REZERO_UNIT:
1122         case SEEK_6:
1123         case SEEK_10:
1124                 /*
1125                  * There are still clients out there which use these old SCSI-2
1126                  * commands. This mainly happens when running VMs with legacy
1127                  * guest systems, connected via SCSI command pass-through to
1128                  * iSCSI targets. Make them happy and return status GOOD.
1129                  */
1130                 size = 0;
1131                 cmd->execute_cmd = sbc_emulate_noop;
1132                 break;
1133         case START_STOP:
1134                 size = 0;
1135                 cmd->execute_cmd = sbc_emulate_startstop;
1136                 break;
1137         default:
1138                 ret = spc_parse_cdb(cmd, &size);
1139                 if (ret)
1140                         return ret;
1141         }
1142
1143         /* reject any command that we don't have a handler for */
1144         if (!cmd->execute_cmd)
1145                 return TCM_UNSUPPORTED_SCSI_OPCODE;
1146
1147         if (cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
1148                 unsigned long long end_lba;
1149 check_lba:
1150                 end_lba = dev->transport->get_blocks(dev) + 1;
1151                 if (((cmd->t_task_lba + sectors) < cmd->t_task_lba) ||
1152                     ((cmd->t_task_lba + sectors) > end_lba)) {
1153                         pr_err("cmd exceeds last lba %llu "
1154                                 "(lba %llu, sectors %u)\n",
1155                                 end_lba, cmd->t_task_lba, sectors);
1156                         return TCM_ADDRESS_OUT_OF_RANGE;
1157                 }
1158
1159                 if (!(cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE))
1160                         size = sbc_get_size(cmd, sectors);
1161         }
1162
1163         return target_cmd_size_check(cmd, size);
1164 }
1165 EXPORT_SYMBOL(sbc_parse_cdb);
1166
1167 u32 sbc_get_device_type(struct se_device *dev)
1168 {
1169         return TYPE_DISK;
1170 }
1171 EXPORT_SYMBOL(sbc_get_device_type);
1172
1173 static sense_reason_t
1174 sbc_execute_unmap(struct se_cmd *cmd)
1175 {
1176         struct sbc_ops *ops = cmd->protocol_data;
1177         struct se_device *dev = cmd->se_dev;
1178         unsigned char *buf, *ptr = NULL;
1179         sector_t lba;
1180         int size;
1181         u32 range;
1182         sense_reason_t ret = 0;
1183         int dl, bd_dl;
1184
1185         /* We never set ANC_SUP */
1186         if (cmd->t_task_cdb[1])
1187                 return TCM_INVALID_CDB_FIELD;
1188
1189         if (cmd->data_length == 0) {
1190                 target_complete_cmd(cmd, SAM_STAT_GOOD);
1191                 return 0;
1192         }
1193
1194         if (cmd->data_length < 8) {
1195                 pr_warn("UNMAP parameter list length %u too small\n",
1196                         cmd->data_length);
1197                 return TCM_PARAMETER_LIST_LENGTH_ERROR;
1198         }
1199
1200         buf = transport_kmap_data_sg(cmd);
1201         if (!buf)
1202                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1203
1204         dl = get_unaligned_be16(&buf[0]);
1205         bd_dl = get_unaligned_be16(&buf[2]);
1206
1207         size = cmd->data_length - 8;
1208         if (bd_dl > size)
1209                 pr_warn("UNMAP parameter list length %u too small, ignoring bd_dl %u\n",
1210                         cmd->data_length, bd_dl);
1211         else
1212                 size = bd_dl;
1213
1214         if (size / 16 > dev->dev_attrib.max_unmap_block_desc_count) {
1215                 ret = TCM_INVALID_PARAMETER_LIST;
1216                 goto err;
1217         }
1218
1219         /* First UNMAP block descriptor starts at 8 byte offset */
1220         ptr = &buf[8];
1221         pr_debug("UNMAP: Sub: %s Using dl: %u bd_dl: %u size: %u"
1222                 " ptr: %p\n", dev->transport->name, dl, bd_dl, size, ptr);
1223
1224         while (size >= 16) {
1225                 lba = get_unaligned_be64(&ptr[0]);
1226                 range = get_unaligned_be32(&ptr[8]);
1227                 pr_debug("UNMAP: Using lba: %llu and range: %u\n",
1228                                  (unsigned long long)lba, range);
1229
1230                 if (range > dev->dev_attrib.max_unmap_lba_count) {
1231                         ret = TCM_INVALID_PARAMETER_LIST;
1232                         goto err;
1233                 }
1234
1235                 if (lba + range > dev->transport->get_blocks(dev) + 1) {
1236                         ret = TCM_ADDRESS_OUT_OF_RANGE;
1237                         goto err;
1238                 }
1239
1240                 if (range) {
1241                         ret = ops->execute_unmap(cmd, lba, range);
1242                         if (ret)
1243                                 goto err;
1244                 }
1245
1246                 ptr += 16;
1247                 size -= 16;
1248         }
1249
1250 err:
1251         transport_kunmap_data_sg(cmd);
1252         if (!ret)
1253                 target_complete_cmd(cmd, SAM_STAT_GOOD);
1254         return ret;
1255 }
1256
1257 void
1258 sbc_dif_generate(struct se_cmd *cmd)
1259 {
1260         struct se_device *dev = cmd->se_dev;
1261         struct t10_pi_tuple *sdt;
1262         struct scatterlist *dsg = cmd->t_data_sg, *psg;
1263         sector_t sector = cmd->t_task_lba;
1264         void *daddr, *paddr;
1265         int i, j, offset = 0;
1266         unsigned int block_size = dev->dev_attrib.block_size;
1267
1268         for_each_sg(cmd->t_prot_sg, psg, cmd->t_prot_nents, i) {
1269                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1270                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1271
1272                 for (j = 0; j < psg->length;
1273                                 j += sizeof(*sdt)) {
1274                         __u16 crc;
1275                         unsigned int avail;
1276
1277                         if (offset >= dsg->length) {
1278                                 offset -= dsg->length;
1279                                 kunmap_atomic(daddr - dsg->offset);
1280                                 dsg = sg_next(dsg);
1281                                 if (!dsg) {
1282                                         kunmap_atomic(paddr - psg->offset);
1283                                         return;
1284                                 }
1285                                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1286                         }
1287
1288                         sdt = paddr + j;
1289                         avail = min(block_size, dsg->length - offset);
1290                         crc = crc_t10dif(daddr + offset, avail);
1291                         if (avail < block_size) {
1292                                 kunmap_atomic(daddr - dsg->offset);
1293                                 dsg = sg_next(dsg);
1294                                 if (!dsg) {
1295                                         kunmap_atomic(paddr - psg->offset);
1296                                         return;
1297                                 }
1298                                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1299                                 offset = block_size - avail;
1300                                 crc = crc_t10dif_update(crc, daddr, offset);
1301                         } else {
1302                                 offset += block_size;
1303                         }
1304
1305                         sdt->guard_tag = cpu_to_be16(crc);
1306                         if (cmd->prot_type == TARGET_DIF_TYPE1_PROT)
1307                                 sdt->ref_tag = cpu_to_be32(sector & 0xffffffff);
1308                         sdt->app_tag = 0;
1309
1310                         pr_debug("DIF %s INSERT sector: %llu guard_tag: 0x%04x"
1311                                  " app_tag: 0x%04x ref_tag: %u\n",
1312                                  (cmd->data_direction == DMA_TO_DEVICE) ?
1313                                  "WRITE" : "READ", (unsigned long long)sector,
1314                                  sdt->guard_tag, sdt->app_tag,
1315                                  be32_to_cpu(sdt->ref_tag));
1316
1317                         sector++;
1318                 }
1319
1320                 kunmap_atomic(daddr - dsg->offset);
1321                 kunmap_atomic(paddr - psg->offset);
1322         }
1323 }
1324
1325 static sense_reason_t
1326 sbc_dif_v1_verify(struct se_cmd *cmd, struct t10_pi_tuple *sdt,
1327                   __u16 crc, sector_t sector, unsigned int ei_lba)
1328 {
1329         __be16 csum;
1330
1331         if (!(cmd->prot_checks & TARGET_DIF_CHECK_GUARD))
1332                 goto check_ref;
1333
1334         csum = cpu_to_be16(crc);
1335
1336         if (sdt->guard_tag != csum) {
1337                 pr_err("DIFv1 checksum failed on sector %llu guard tag 0x%04x"
1338                         " csum 0x%04x\n", (unsigned long long)sector,
1339                         be16_to_cpu(sdt->guard_tag), be16_to_cpu(csum));
1340                 return TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED;
1341         }
1342
1343 check_ref:
1344         if (!(cmd->prot_checks & TARGET_DIF_CHECK_REFTAG))
1345                 return 0;
1346
1347         if (cmd->prot_type == TARGET_DIF_TYPE1_PROT &&
1348             be32_to_cpu(sdt->ref_tag) != (sector & 0xffffffff)) {
1349                 pr_err("DIFv1 Type 1 reference failed on sector: %llu tag: 0x%08x"
1350                        " sector MSB: 0x%08x\n", (unsigned long long)sector,
1351                        be32_to_cpu(sdt->ref_tag), (u32)(sector & 0xffffffff));
1352                 return TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;
1353         }
1354
1355         if (cmd->prot_type == TARGET_DIF_TYPE2_PROT &&
1356             be32_to_cpu(sdt->ref_tag) != ei_lba) {
1357                 pr_err("DIFv1 Type 2 reference failed on sector: %llu tag: 0x%08x"
1358                        " ei_lba: 0x%08x\n", (unsigned long long)sector,
1359                         be32_to_cpu(sdt->ref_tag), ei_lba);
1360                 return TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;
1361         }
1362
1363         return 0;
1364 }
1365
1366 void sbc_dif_copy_prot(struct se_cmd *cmd, unsigned int sectors, bool read,
1367                        struct scatterlist *sg, int sg_off)
1368 {
1369         struct se_device *dev = cmd->se_dev;
1370         struct scatterlist *psg;
1371         void *paddr, *addr;
1372         unsigned int i, len, left;
1373         unsigned int offset = sg_off;
1374
1375         if (!sg)
1376                 return;
1377
1378         left = sectors * dev->prot_length;
1379
1380         for_each_sg(cmd->t_prot_sg, psg, cmd->t_prot_nents, i) {
1381                 unsigned int psg_len, copied = 0;
1382
1383                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1384                 psg_len = min(left, psg->length);
1385                 while (psg_len) {
1386                         len = min(psg_len, sg->length - offset);
1387                         addr = kmap_atomic(sg_page(sg)) + sg->offset + offset;
1388
1389                         if (read)
1390                                 memcpy(paddr + copied, addr, len);
1391                         else
1392                                 memcpy(addr, paddr + copied, len);
1393
1394                         left -= len;
1395                         offset += len;
1396                         copied += len;
1397                         psg_len -= len;
1398
1399                         kunmap_atomic(addr - sg->offset - offset);
1400
1401                         if (offset >= sg->length) {
1402                                 sg = sg_next(sg);
1403                                 offset = 0;
1404                         }
1405                 }
1406                 kunmap_atomic(paddr - psg->offset);
1407         }
1408 }
1409 EXPORT_SYMBOL(sbc_dif_copy_prot);
1410
1411 sense_reason_t
1412 sbc_dif_verify(struct se_cmd *cmd, sector_t start, unsigned int sectors,
1413                unsigned int ei_lba, struct scatterlist *psg, int psg_off)
1414 {
1415         struct se_device *dev = cmd->se_dev;
1416         struct t10_pi_tuple *sdt;
1417         struct scatterlist *dsg = cmd->t_data_sg;
1418         sector_t sector = start;
1419         void *daddr, *paddr;
1420         int i;
1421         sense_reason_t rc;
1422         int dsg_off = 0;
1423         unsigned int block_size = dev->dev_attrib.block_size;
1424
1425         for (; psg && sector < start + sectors; psg = sg_next(psg)) {
1426                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1427                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1428
1429                 for (i = psg_off; i < psg->length &&
1430                                 sector < start + sectors;
1431                                 i += sizeof(*sdt)) {
1432                         __u16 crc;
1433                         unsigned int avail;
1434
1435                         if (dsg_off >= dsg->length) {
1436                                 dsg_off -= dsg->length;
1437                                 kunmap_atomic(daddr - dsg->offset);
1438                                 dsg = sg_next(dsg);
1439                                 if (!dsg) {
1440                                         kunmap_atomic(paddr - psg->offset);
1441                                         return 0;
1442                                 }
1443                                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1444                         }
1445
1446                         sdt = paddr + i;
1447
1448                         pr_debug("DIF READ sector: %llu guard_tag: 0x%04x"
1449                                  " app_tag: 0x%04x ref_tag: %u\n",
1450                                  (unsigned long long)sector, sdt->guard_tag,
1451                                  sdt->app_tag, be32_to_cpu(sdt->ref_tag));
1452
1453                         if (sdt->app_tag == T10_PI_APP_ESCAPE) {
1454                                 dsg_off += block_size;
1455                                 goto next;
1456                         }
1457
1458                         avail = min(block_size, dsg->length - dsg_off);
1459                         crc = crc_t10dif(daddr + dsg_off, avail);
1460                         if (avail < block_size) {
1461                                 kunmap_atomic(daddr - dsg->offset);
1462                                 dsg = sg_next(dsg);
1463                                 if (!dsg) {
1464                                         kunmap_atomic(paddr - psg->offset);
1465                                         return 0;
1466                                 }
1467                                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1468                                 dsg_off = block_size - avail;
1469                                 crc = crc_t10dif_update(crc, daddr, dsg_off);
1470                         } else {
1471                                 dsg_off += block_size;
1472                         }
1473
1474                         rc = sbc_dif_v1_verify(cmd, sdt, crc, sector, ei_lba);
1475                         if (rc) {
1476                                 kunmap_atomic(daddr - dsg->offset);
1477                                 kunmap_atomic(paddr - psg->offset);
1478                                 cmd->sense_info = sector;
1479                                 return rc;
1480                         }
1481 next:
1482                         sector++;
1483                         ei_lba++;
1484                 }
1485
1486                 psg_off = 0;
1487                 kunmap_atomic(daddr - dsg->offset);
1488                 kunmap_atomic(paddr - psg->offset);
1489         }
1490
1491         return 0;
1492 }
1493 EXPORT_SYMBOL(sbc_dif_verify);