drivers/target/target_core_sbc.c

   1 /*
   2  * SCSI Block Commands (SBC) parsing and emulation.
   3  *
   4  * (c) Copyright 2002-2013 Datera, Inc.
   5  *
   6  * Nicholas A. Bellinger <nab@kernel.org>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  21  */
  22
  23 #include <linux/kernel.h>
  24 #include <linux/module.h>
  25 #include <linux/ratelimit.h>
  26 #include <linux/crc-t10dif.h>
  27 #include <linux/t10-pi.h>
  28 #include <asm/unaligned.h>
  29 #include <scsi/scsi_proto.h>
  30 #include <scsi/scsi_tcq.h>
  31
  32 #include <target/target_core_base.h>
  33 #include <target/target_core_backend.h>
  34 #include <target/target_core_fabric.h>
  35
  36 #include "target_core_internal.h"
  37 #include "target_core_ua.h"
  38 #include "target_core_alua.h"
  39
  40 static sense_reason_t
  41 sbc_check_prot(struct se_device *, struct se_cmd *, unsigned char, u32, bool);
  42 static sense_reason_t sbc_execute_unmap(struct se_cmd *cmd);
  43
  44 static sense_reason_t
  45 sbc_emulate_readcapacity(struct se_cmd *cmd)
  46 {
  47         struct se_device *dev = cmd->se_dev;
  48         unsigned char *cdb = cmd->t_task_cdb;
  49         unsigned long long blocks_long = dev->transport->get_blocks(dev);
  50         unsigned char *rbuf;
  51         unsigned char buf[8];
  52         u32 blocks;
  53
  54         /*
  55          * SBC-2 says:
  56          *   If the PMI bit is set to zero and the LOGICAL BLOCK
  57          *   ADDRESS field is not set to zero, the device server shall
  58          *   terminate the command with CHECK CONDITION status with
  59          *   the sense key set to ILLEGAL REQUEST and the additional
  60          *   sense code set to INVALID FIELD IN CDB.
  61          *
  62          * In SBC-3, these fields are obsolete, but some SCSI
  63          * compliance tests actually check this, so we might as well
  64          * follow SBC-2.
  65          */
  66         if (!(cdb[8] & 1) && !!(cdb[2] | cdb[3] | cdb[4] | cdb[5]))
  67                 return TCM_INVALID_CDB_FIELD;
  68
  69         if (blocks_long >= 0x00000000ffffffff)
  70                 blocks = 0xffffffff;
  71         else
  72                 blocks = (u32)blocks_long;
  73
  74         put_unaligned_be32(blocks, &buf[0]);
  75         put_unaligned_be32(dev->dev_attrib.block_size, &buf[4]);
  76
  77         rbuf = transport_kmap_data_sg(cmd);
  78         if (rbuf) {
  79                 memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length));
  80                 transport_kunmap_data_sg(cmd);
  81         }
  82
  83         target_complete_cmd_with_length(cmd, GOOD, 8);
  84         return 0;
  85 }
  86
  87 static sense_reason_t
  88 sbc_emulate_readcapacity_16(struct se_cmd *cmd)
  89 {
  90         struct se_device *dev = cmd->se_dev;
  91         struct se_session *sess = cmd->se_sess;
  92         int pi_prot_type = dev->dev_attrib.pi_prot_type;
  93
  94         unsigned char *rbuf;
  95         unsigned char buf[32];
  96         unsigned long long blocks = dev->transport->get_blocks(dev);
  97
  98         memset(buf, 0, sizeof(buf));
  99         put_unaligned_be64(blocks, &buf[0]);
 100         put_unaligned_be32(dev->dev_attrib.block_size, &buf[8]);
 101         /*
 102          * Set P_TYPE and PROT_EN bits for DIF support
 103          */
 104         if (sess->sup_prot_ops & (TARGET_PROT_DIN_PASS | TARGET_PROT_DOUT_PASS)) {
 105                 /*
 106                  * Only override a device's pi_prot_type if no T10-PI is
 107                  * available, and sess_prot_type has been explicitly enabled.
 108                  */
 109                 if (!pi_prot_type)
 110                         pi_prot_type = sess->sess_prot_type;
 111
 112                 if (pi_prot_type)
 113                         buf[12] = (pi_prot_type - 1) << 1 | 0x1;
 114         }
 115
 116         if (dev->transport->get_lbppbe)
 117                 buf[13] = dev->transport->get_lbppbe(dev) & 0x0f;
 118
 119         if (dev->transport->get_alignment_offset_lbas) {
 120                 u16 lalba = dev->transport->get_alignment_offset_lbas(dev);
 121
 122                 put_unaligned_be16(lalba, &buf[14]);
 123         }
 124
 125         /*
 126          * Set Thin Provisioning Enable bit following sbc3r22 in section
 127          * READ CAPACITY (16) byte 14 if emulate_tpu or emulate_tpws is enabled.
 128          */
 129         if (dev->dev_attrib.emulate_tpu || dev->dev_attrib.emulate_tpws) {
 130                 buf[14] |= 0x80;
 131
 132                 /*
 133                  * LBPRZ signifies that zeroes will be read back from an LBA after
 134                  * an UNMAP or WRITE SAME w/ unmap bit (sbc3r36 5.16.2)
 135                  */
 136                 if (dev->dev_attrib.unmap_zeroes_data)
 137                         buf[14] |= 0x40;
 138         }
 139
 140         rbuf = transport_kmap_data_sg(cmd);
 141         if (rbuf) {
 142                 memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length));
 143                 transport_kunmap_data_sg(cmd);
 144         }
 145
 146         target_complete_cmd_with_length(cmd, GOOD, 32);
 147         return 0;
 148 }
 149
 150 static sense_reason_t
 151 sbc_emulate_startstop(struct se_cmd *cmd)
 152 {
 153         unsigned char *cdb = cmd->t_task_cdb;
 154
 155         /*
 156          * See sbc3r36 section 5.25
 157          * Immediate bit should be set since there is nothing to complete
 158          * POWER CONDITION MODIFIER 0h
 159          */
 160         if (!(cdb[1] & 1) || cdb[2] || cdb[3])
 161                 return TCM_INVALID_CDB_FIELD;
 162
 163         /*
 164          * See sbc3r36 section 5.25
 165          * POWER CONDITION 0h START_VALID - process START and LOEJ
 166          */
 167         if (cdb[4] >> 4 & 0xf)
 168                 return TCM_INVALID_CDB_FIELD;
 169
 170         /*
 171          * See sbc3r36 section 5.25
 172          * LOEJ 0h - nothing to load or unload
 173          * START 1h - we are ready
 174          */
 175         if (!(cdb[4] & 1) || (cdb[4] & 2) || (cdb[4] & 4))
 176                 return TCM_INVALID_CDB_FIELD;
 177
 178         target_complete_cmd(cmd, SAM_STAT_GOOD);
 179         return 0;
 180 }
 181
 182 sector_t sbc_get_write_same_sectors(struct se_cmd *cmd)
 183 {
 184         u32 num_blocks;
 185
 186         if (cmd->t_task_cdb[0] == WRITE_SAME)
 187                 num_blocks = get_unaligned_be16(&cmd->t_task_cdb[7]);
 188         else if (cmd->t_task_cdb[0] == WRITE_SAME_16)
 189                 num_blocks = get_unaligned_be32(&cmd->t_task_cdb[10]);
 190         else /* WRITE_SAME_32 via VARIABLE_LENGTH_CMD */
 191                 num_blocks = get_unaligned_be32(&cmd->t_task_cdb[28]);
 192
 193         /*
 194          * Use the explicit range when non zero is supplied, otherwise calculate
 195          * the remaining range based on ->get_blocks() - starting LBA.
 196          */
 197         if (num_blocks)
 198                 return num_blocks;
 199
 200         return cmd->se_dev->transport->get_blocks(cmd->se_dev) -
 201                 cmd->t_task_lba + 1;
 202 }
 203 EXPORT_SYMBOL(sbc_get_write_same_sectors);
 204
 205 static sense_reason_t
 206 sbc_execute_write_same_unmap(struct se_cmd *cmd)
 207 {
 208         struct sbc_ops *ops = cmd->protocol_data;
 209         sector_t nolb = sbc_get_write_same_sectors(cmd);
 210         sense_reason_t ret;
 211
 212         if (nolb) {
 213                 ret = ops->execute_unmap(cmd, cmd->t_task_lba, nolb);
 214                 if (ret)
 215                         return ret;
 216         }
 217
 218         target_complete_cmd(cmd, GOOD);
 219         return 0;
 220 }
 221
 222 static sense_reason_t
 223 sbc_emulate_noop(struct se_cmd *cmd)
 224 {
 225         target_complete_cmd(cmd, GOOD);
 226         return 0;
 227 }
 228
 229 static inline u32 sbc_get_size(struct se_cmd *cmd, u32 sectors)
 230 {
 231         return cmd->se_dev->dev_attrib.block_size * sectors;
 232 }
 233
 234 static inline u32 transport_get_sectors_6(unsigned char *cdb)
 235 {
 236         /*
 237          * Use 8-bit sector value.  SBC-3 says:
 238          *
 239          *   A TRANSFER LENGTH field set to zero specifies that 256
 240          *   logical blocks shall be written.  Any other value
 241          *   specifies the number of logical blocks that shall be
 242          *   written.
 243          */
 244         return cdb[4] ? : 256;
 245 }
 246
 247 static inline u32 transport_get_sectors_10(unsigned char *cdb)
 248 {
 249         return get_unaligned_be16(&cdb[7]);
 250 }
 251
 252 static inline u32 transport_get_sectors_12(unsigned char *cdb)
 253 {
 254         return get_unaligned_be32(&cdb[6]);
 255 }
 256
 257 static inline u32 transport_get_sectors_16(unsigned char *cdb)
 258 {
 259         return get_unaligned_be32(&cdb[10]);
 260 }
 261
 262 /*
 263  * Used for VARIABLE_LENGTH_CDB WRITE_32 and READ_32 variants
 264  */
 265 static inline u32 transport_get_sectors_32(unsigned char *cdb)
 266 {
 267         return get_unaligned_be32(&cdb[28]);
 268
 269 }
 270
 271 static inline u32 transport_lba_21(unsigned char *cdb)
 272 {
 273         return get_unaligned_be24(&cdb[1]) & 0x1fffff;
 274 }
 275
 276 static inline u32 transport_lba_32(unsigned char *cdb)
 277 {
 278         return get_unaligned_be32(&cdb[2]);
 279 }
 280
 281 static inline unsigned long long transport_lba_64(unsigned char *cdb)
 282 {
 283         return get_unaligned_be64(&cdb[2]);
 284 }
 285
 286 /*
 287  * For VARIABLE_LENGTH_CDB w/ 32 byte extended CDBs
 288  */
 289 static inline unsigned long long transport_lba_64_ext(unsigned char *cdb)
 290 {
 291         return get_unaligned_be64(&cdb[12]);
 292 }
 293
 294 static sense_reason_t
 295 sbc_setup_write_same(struct se_cmd *cmd, unsigned char flags, struct sbc_ops *ops)
 296 {
 297         struct se_device *dev = cmd->se_dev;
 298         sector_t end_lba = dev->transport->get_blocks(dev) + 1;
 299         unsigned int sectors = sbc_get_write_same_sectors(cmd);
 300         sense_reason_t ret;
 301
 302         if ((flags & 0x04) || (flags & 0x02)) {
 303                 pr_err("WRITE_SAME PBDATA and LBDATA"
 304                         " bits not supported for Block Discard"
 305                         " Emulation\n");
 306                 return TCM_UNSUPPORTED_SCSI_OPCODE;
 307         }
 308         if (sectors > cmd->se_dev->dev_attrib.max_write_same_len) {
 309                 pr_warn("WRITE_SAME sectors: %u exceeds max_write_same_len: %u\n",
 310                         sectors, cmd->se_dev->dev_attrib.max_write_same_len);
 311                 return TCM_INVALID_CDB_FIELD;
 312         }
 313         /*
 314          * Sanity check for LBA wrap and request past end of device.
 315          */
 316         if (((cmd->t_task_lba + sectors) < cmd->t_task_lba) ||
 317             ((cmd->t_task_lba + sectors) > end_lba)) {
 318                 pr_err("WRITE_SAME exceeds last lba %llu (lba %llu, sectors %u)\n",
 319                        (unsigned long long)end_lba, cmd->t_task_lba, sectors);
 320                 return TCM_ADDRESS_OUT_OF_RANGE;
 321         }
 322
 323         /* We always have ANC_SUP == 0 so setting ANCHOR is always an error */
 324         if (flags & 0x10) {
 325                 pr_warn("WRITE SAME with ANCHOR not supported\n");
 326                 return TCM_INVALID_CDB_FIELD;
 327         }
 328         /*
 329          * Special case for WRITE_SAME w/ UNMAP=1 that ends up getting
 330          * translated into block discard requests within backend code.
 331          */
 332         if (flags & 0x08) {
 333                 if (!ops->execute_unmap)
 334                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 335
 336                 if (!dev->dev_attrib.emulate_tpws) {
 337                         pr_err("Got WRITE_SAME w/ UNMAP=1, but backend device"
 338                                " has emulate_tpws disabled\n");
 339                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 340                 }
 341                 cmd->execute_cmd = sbc_execute_write_same_unmap;
 342                 return 0;
 343         }
 344         if (!ops->execute_write_same)
 345                 return TCM_UNSUPPORTED_SCSI_OPCODE;
 346
 347         ret = sbc_check_prot(dev, cmd, flags >> 5, sectors, true);
 348         if (ret)
 349                 return ret;
 350
 351         cmd->execute_cmd = ops->execute_write_same;
 352         return 0;
 353 }
 354
 355 static sense_reason_t xdreadwrite_callback(struct se_cmd *cmd, bool success,
 356                                            int *post_ret)
 357 {
 358         unsigned char *buf, *addr;
 359         struct scatterlist *sg;
 360         unsigned int offset;
 361         sense_reason_t ret = TCM_NO_SENSE;
 362         int i, count;
 363         /*
 364          * From sbc3r22.pdf section 5.48 XDWRITEREAD (10) command
 365          *
 366          * 1) read the specified logical block(s);
 367          * 2) transfer logical blocks from the data-out buffer;
 368          * 3) XOR the logical blocks transferred from the data-out buffer with
 369          *    the logical blocks read, storing the resulting XOR data in a buffer;
 370          * 4) if the DISABLE WRITE bit is set to zero, then write the logical
 371          *    blocks transferred from the data-out buffer; and
 372          * 5) transfer the resulting XOR data to the data-in buffer.
 373          */
 374         buf = kmalloc(cmd->data_length, GFP_KERNEL);
 375         if (!buf) {
 376                 pr_err("Unable to allocate xor_callback buf\n");
 377                 return TCM_OUT_OF_RESOURCES;
 378         }
 379         /*
 380          * Copy the scatterlist WRITE buffer located at cmd->t_data_sg
 381          * into the locally allocated *buf
 382          */
 383         sg_copy_to_buffer(cmd->t_data_sg,
 384                           cmd->t_data_nents,
 385                           buf,
 386                           cmd->data_length);
 387
 388         /*
 389          * Now perform the XOR against the BIDI read memory located at
 390          * cmd->t_mem_bidi_list
 391          */
 392
 393         offset = 0;
 394         for_each_sg(cmd->t_bidi_data_sg, sg, cmd->t_bidi_data_nents, count) {
 395                 addr = kmap_atomic(sg_page(sg));
 396                 if (!addr) {
 397                         ret = TCM_OUT_OF_RESOURCES;
 398                         goto out;
 399                 }
 400
 401                 for (i = 0; i < sg->length; i++)
 402                         *(addr + sg->offset + i) ^= *(buf + offset + i);
 403
 404                 offset += sg->length;
 405                 kunmap_atomic(addr);
 406         }
 407
 408 out:
 409         kfree(buf);
 410         return ret;
 411 }
 412
 413 static sense_reason_t
 414 sbc_execute_rw(struct se_cmd *cmd)
 415 {
 416         struct sbc_ops *ops = cmd->protocol_data;
 417
 418         return ops->execute_rw(cmd, cmd->t_data_sg, cmd->t_data_nents,
 419                                cmd->data_direction);
 420 }
 421
 422 static sense_reason_t compare_and_write_post(struct se_cmd *cmd, bool success,
 423                                              int *post_ret)
 424 {
 425         struct se_device *dev = cmd->se_dev;
 426         sense_reason_t ret = TCM_NO_SENSE;
 427
 428         /*
 429          * Only set SCF_COMPARE_AND_WRITE_POST to force a response fall-through
 430          * within target_complete_ok_work() if the command was successfully
 431          * sent to the backend driver.
 432          */
 433         spin_lock_irq(&cmd->t_state_lock);
 434         if (cmd->transport_state & CMD_T_SENT) {
 435                 cmd->se_cmd_flags |= SCF_COMPARE_AND_WRITE_POST;
 436                 *post_ret = 1;
 437
 438                 if (cmd->scsi_status == SAM_STAT_CHECK_CONDITION)
 439                         ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 440         }
 441         spin_unlock_irq(&cmd->t_state_lock);
 442
 443         /*
 444          * Unlock ->caw_sem originally obtained during sbc_compare_and_write()
 445          * before the original READ I/O submission.
 446          */
 447         up(&dev->caw_sem);
 448
 449         return ret;
 450 }
 451
 452 static sense_reason_t compare_and_write_callback(struct se_cmd *cmd, bool success,
 453                                                  int *post_ret)
 454 {
 455         struct se_device *dev = cmd->se_dev;
 456         struct scatterlist *write_sg = NULL, *sg;
 457         unsigned char *buf = NULL, *addr;
 458         struct sg_mapping_iter m;
 459         unsigned int offset = 0, len;
 460         unsigned int nlbas = cmd->t_task_nolb;
 461         unsigned int block_size = dev->dev_attrib.block_size;
 462         unsigned int compare_len = (nlbas * block_size);
 463         sense_reason_t ret = TCM_NO_SENSE;
 464         int rc, i;
 465
 466         /*
 467          * Handle early failure in transport_generic_request_failure(),
 468          * which will not have taken ->caw_sem yet..
 469          */
 470         if (!success && (!cmd->t_data_sg || !cmd->t_bidi_data_sg))
 471                 return TCM_NO_SENSE;
 472         /*
 473          * Handle special case for zero-length COMPARE_AND_WRITE
 474          */
 475         if (!cmd->data_length)
 476                 goto out;
 477         /*
 478          * Immediately exit + release dev->caw_sem if command has already
 479          * been failed with a non-zero SCSI status.
 480          */
 481         if (cmd->scsi_status) {
 482                 pr_debug("compare_and_write_callback: non zero scsi_status:"
 483                         " 0x%02x\n", cmd->scsi_status);
 484                 *post_ret = 1;
 485                 if (cmd->scsi_status == SAM_STAT_CHECK_CONDITION)
 486                         ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 487                 goto out;
 488         }
 489
 490         buf = kzalloc(cmd->data_length, GFP_KERNEL);
 491         if (!buf) {
 492                 pr_err("Unable to allocate compare_and_write buf\n");
 493                 ret = TCM_OUT_OF_RESOURCES;
 494                 goto out;
 495         }
 496
 497         write_sg = kmalloc_array(cmd->t_data_nents, sizeof(*write_sg),
 498                                  GFP_KERNEL);
 499         if (!write_sg) {
 500                 pr_err("Unable to allocate compare_and_write sg\n");
 501                 ret = TCM_OUT_OF_RESOURCES;
 502                 goto out;
 503         }
 504         sg_init_table(write_sg, cmd->t_data_nents);
 505         /*
 506          * Setup verify and write data payloads from total NumberLBAs.
 507          */
 508         rc = sg_copy_to_buffer(cmd->t_data_sg, cmd->t_data_nents, buf,
 509                                cmd->data_length);
 510         if (!rc) {
 511                 pr_err("sg_copy_to_buffer() failed for compare_and_write\n");
 512                 ret = TCM_OUT_OF_RESOURCES;
 513                 goto out;
 514         }
 515         /*
 516          * Compare against SCSI READ payload against verify payload
 517          */
 518         for_each_sg(cmd->t_bidi_data_sg, sg, cmd->t_bidi_data_nents, i) {
 519                 addr = (unsigned char *)kmap_atomic(sg_page(sg));
 520                 if (!addr) {
 521                         ret = TCM_OUT_OF_RESOURCES;
 522                         goto out;
 523                 }
 524
 525                 len = min(sg->length, compare_len);
 526
 527                 if (memcmp(addr, buf + offset, len)) {
 528                         pr_warn("Detected MISCOMPARE for addr: %p buf: %p\n",
 529                                 addr, buf + offset);
 530                         kunmap_atomic(addr);
 531                         goto miscompare;
 532                 }
 533                 kunmap_atomic(addr);
 534
 535                 offset += len;
 536                 compare_len -= len;
 537                 if (!compare_len)
 538                         break;
 539         }
 540
 541         i = 0;
 542         len = cmd->t_task_nolb * block_size;
 543         sg_miter_start(&m, cmd->t_data_sg, cmd->t_data_nents, SG_MITER_TO_SG);
 544         /*
 545          * Currently assumes NoLB=1 and SGLs are PAGE_SIZE..
 546          */
 547         while (len) {
 548                 sg_miter_next(&m);
 549
 550                 if (block_size < PAGE_SIZE) {
 551                         sg_set_page(&write_sg[i], m.page, block_size,
 552                                     m.piter.sg->offset + block_size);
 553                 } else {
 554                         sg_miter_next(&m);
 555                         sg_set_page(&write_sg[i], m.page, block_size,
 556                                     m.piter.sg->offset);
 557                 }
 558                 len -= block_size;
 559                 i++;
 560         }
 561         sg_miter_stop(&m);
 562         /*
 563          * Save the original SGL + nents values before updating to new
 564          * assignments, to be released in transport_free_pages() ->
 565          * transport_reset_sgl_orig()
 566          */
 567         cmd->t_data_sg_orig = cmd->t_data_sg;
 568         cmd->t_data_sg = write_sg;
 569         cmd->t_data_nents_orig = cmd->t_data_nents;
 570         cmd->t_data_nents = 1;
 571
 572         cmd->sam_task_attr = TCM_HEAD_TAG;
 573         cmd->transport_complete_callback = compare_and_write_post;
 574         /*
 575          * Now reset ->execute_cmd() to the normal sbc_execute_rw() handler
 576          * for submitting the adjusted SGL to write instance user-data.
 577          */
 578         cmd->execute_cmd = sbc_execute_rw;
 579
 580         spin_lock_irq(&cmd->t_state_lock);
 581         cmd->t_state = TRANSPORT_PROCESSING;
 582         cmd->transport_state |= CMD_T_ACTIVE | CMD_T_SENT;
 583         spin_unlock_irq(&cmd->t_state_lock);
 584
 585         __target_execute_cmd(cmd, false);
 586
 587         kfree(buf);
 588         return ret;
 589
 590 miscompare:
 591         pr_warn("Target/%s: Send MISCOMPARE check condition and sense\n",
 592                 dev->transport->name);
 593         ret = TCM_MISCOMPARE_VERIFY;
 594 out:
 595         /*
 596          * In the MISCOMPARE or failure case, unlock ->caw_sem obtained in
 597          * sbc_compare_and_write() before the original READ I/O submission.
 598          */
 599         up(&dev->caw_sem);
 600         kfree(write_sg);
 601         kfree(buf);
 602         return ret;
 603 }
 604
 605 static sense_reason_t
 606 sbc_compare_and_write(struct se_cmd *cmd)
 607 {
 608         struct sbc_ops *ops = cmd->protocol_data;
 609         struct se_device *dev = cmd->se_dev;
 610         sense_reason_t ret;
 611         int rc;
 612         /*
 613          * Submit the READ first for COMPARE_AND_WRITE to perform the
 614          * comparision using SGLs at cmd->t_bidi_data_sg..
 615          */
 616         rc = down_interruptible(&dev->caw_sem);
 617         if (rc != 0) {
 618                 cmd->transport_complete_callback = NULL;
 619                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 620         }
 621         /*
 622          * Reset cmd->data_length to individual block_size in order to not
 623          * confuse backend drivers that depend on this value matching the
 624          * size of the I/O being submitted.
 625          */
 626         cmd->data_length = cmd->t_task_nolb * dev->dev_attrib.block_size;
 627
 628         ret = ops->execute_rw(cmd, cmd->t_bidi_data_sg, cmd->t_bidi_data_nents,
 629                               DMA_FROM_DEVICE);
 630         if (ret) {
 631                 cmd->transport_complete_callback = NULL;
 632                 up(&dev->caw_sem);
 633                 return ret;
 634         }
 635         /*
 636          * Unlock of dev->caw_sem to occur in compare_and_write_callback()
 637          * upon MISCOMPARE, or in compare_and_write_done() upon completion
 638          * of WRITE instance user-data.
 639          */
 640         return TCM_NO_SENSE;
 641 }
 642
 643 static int
 644 sbc_set_prot_op_checks(u8 protect, bool fabric_prot, enum target_prot_type prot_type,
 645                        bool is_write, struct se_cmd *cmd)
 646 {
 647         if (is_write) {
 648                 cmd->prot_op = fabric_prot ? TARGET_PROT_DOUT_STRIP :
 649                                protect ? TARGET_PROT_DOUT_PASS :
 650                                TARGET_PROT_DOUT_INSERT;
 651                 switch (protect) {
 652                 case 0x0:
 653                 case 0x3:
 654                         cmd->prot_checks = 0;
 655                         break;
 656                 case 0x1:
 657                 case 0x5:
 658                         cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
 659                         if (prot_type == TARGET_DIF_TYPE1_PROT)
 660                                 cmd->prot_checks |= TARGET_DIF_CHECK_REFTAG;
 661                         break;
 662                 case 0x2:
 663                         if (prot_type == TARGET_DIF_TYPE1_PROT)
 664                                 cmd->prot_checks = TARGET_DIF_CHECK_REFTAG;
 665                         break;
 666                 case 0x4:
 667                         cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
 668                         break;
 669                 default:
 670                         pr_err("Unsupported protect field %d\n", protect);
 671                         return -EINVAL;
 672                 }
 673         } else {
 674                 cmd->prot_op = fabric_prot ? TARGET_PROT_DIN_INSERT :
 675                                protect ? TARGET_PROT_DIN_PASS :
 676                                TARGET_PROT_DIN_STRIP;
 677                 switch (protect) {
 678                 case 0x0:
 679                 case 0x1:
 680                 case 0x5:
 681                         cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
 682                         if (prot_type == TARGET_DIF_TYPE1_PROT)
 683                                 cmd->prot_checks |= TARGET_DIF_CHECK_REFTAG;
 684                         break;
 685                 case 0x2:
 686                         if (prot_type == TARGET_DIF_TYPE1_PROT)
 687                                 cmd->prot_checks = TARGET_DIF_CHECK_REFTAG;
 688                         break;
 689                 case 0x3:
 690                         cmd->prot_checks = 0;
 691                         break;
 692                 case 0x4:
 693                         cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
 694                         break;
 695                 default:
 696                         pr_err("Unsupported protect field %d\n", protect);
 697                         return -EINVAL;
 698                 }
 699         }
 700
 701         return 0;
 702 }
 703
 704 static sense_reason_t
 705 sbc_check_prot(struct se_device *dev, struct se_cmd *cmd, unsigned char protect,
 706                u32 sectors, bool is_write)
 707 {
 708         int sp_ops = cmd->se_sess->sup_prot_ops;
 709         int pi_prot_type = dev->dev_attrib.pi_prot_type;
 710         bool fabric_prot = false;
 711
 712         if (!cmd->t_prot_sg || !cmd->t_prot_nents) {
 713                 if (unlikely(protect &&
 714                     !dev->dev_attrib.pi_prot_type && !cmd->se_sess->sess_prot_type)) {
 715                         pr_err("CDB contains protect bit, but device + fabric does"
 716                                " not advertise PROTECT=1 feature bit\n");
 717                         return TCM_INVALID_CDB_FIELD;
 718                 }
 719                 if (cmd->prot_pto)
 720                         return TCM_NO_SENSE;
 721         }
 722
 723         switch (dev->dev_attrib.pi_prot_type) {
 724         case TARGET_DIF_TYPE3_PROT:
 725                 cmd->reftag_seed = 0xffffffff;
 726                 break;
 727         case TARGET_DIF_TYPE2_PROT:
 728                 if (protect)
 729                         return TCM_INVALID_CDB_FIELD;
 730
 731                 cmd->reftag_seed = cmd->t_task_lba;
 732                 break;
 733         case TARGET_DIF_TYPE1_PROT:
 734                 cmd->reftag_seed = cmd->t_task_lba;
 735                 break;
 736         case TARGET_DIF_TYPE0_PROT:
 737                 /*
 738                  * See if the fabric supports T10-PI, and the session has been
 739                  * configured to allow export PROTECT=1 feature bit with backend
 740                  * devices that don't support T10-PI.
 741                  */
 742                 fabric_prot = is_write ?
 743                               !!(sp_ops & (TARGET_PROT_DOUT_PASS | TARGET_PROT_DOUT_STRIP)) :
 744                               !!(sp_ops & (TARGET_PROT_DIN_PASS | TARGET_PROT_DIN_INSERT));
 745
 746                 if (fabric_prot && cmd->se_sess->sess_prot_type) {
 747                         pi_prot_type = cmd->se_sess->sess_prot_type;
 748                         break;
 749                 }
 750                 if (!protect)
 751                         return TCM_NO_SENSE;
 752                 /* Fallthrough */
 753         default:
 754                 pr_err("Unable to determine pi_prot_type for CDB: 0x%02x "
 755                        "PROTECT: 0x%02x\n", cmd->t_task_cdb[0], protect);
 756                 return TCM_INVALID_CDB_FIELD;
 757         }
 758
 759         if (sbc_set_prot_op_checks(protect, fabric_prot, pi_prot_type, is_write, cmd))
 760                 return TCM_INVALID_CDB_FIELD;
 761
 762         cmd->prot_type = pi_prot_type;
 763         cmd->prot_length = dev->prot_length * sectors;
 764
 765         /**
 766          * In case protection information exists over the wire
 767          * we modify command data length to describe pure data.
 768          * The actual transfer length is data length + protection
 769          * length
 770          **/
 771         if (protect)
 772                 cmd->data_length = sectors * dev->dev_attrib.block_size;
 773
 774         pr_debug("%s: prot_type=%d, data_length=%d, prot_length=%d "
 775                  "prot_op=%d prot_checks=%d\n",
 776                  __func__, cmd->prot_type, cmd->data_length, cmd->prot_length,
 777                  cmd->prot_op, cmd->prot_checks);
 778
 779         return TCM_NO_SENSE;
 780 }
 781
 782 static int
 783 sbc_check_dpofua(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb)
 784 {
 785         if (cdb[1] & 0x10) {
 786                 /* see explanation in spc_emulate_modesense */
 787                 if (!target_check_fua(dev)) {
 788                         pr_err("Got CDB: 0x%02x with DPO bit set, but device"
 789                                " does not advertise support for DPO\n", cdb[0]);
 790                         return -EINVAL;
 791                 }
 792         }
 793         if (cdb[1] & 0x8) {
 794                 if (!target_check_fua(dev)) {
 795                         pr_err("Got CDB: 0x%02x with FUA bit set, but device"
 796                                " does not advertise support for FUA write\n",
 797                                cdb[0]);
 798                         return -EINVAL;
 799                 }
 800                 cmd->se_cmd_flags |= SCF_FUA;
 801         }
 802         return 0;
 803 }
 804
 805 sense_reason_t
 806 sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
 807 {
 808         struct se_device *dev = cmd->se_dev;
 809         unsigned char *cdb = cmd->t_task_cdb;
 810         unsigned int size;
 811         u32 sectors = 0;
 812         sense_reason_t ret;
 813
 814         cmd->protocol_data = ops;
 815
 816         switch (cdb[0]) {
 817         case READ_6:
 818                 sectors = transport_get_sectors_6(cdb);
 819                 cmd->t_task_lba = transport_lba_21(cdb);
 820                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 821                 cmd->execute_cmd = sbc_execute_rw;
 822                 break;
 823         case READ_10:
 824                 sectors = transport_get_sectors_10(cdb);
 825                 cmd->t_task_lba = transport_lba_32(cdb);
 826
 827                 if (sbc_check_dpofua(dev, cmd, cdb))
 828                         return TCM_INVALID_CDB_FIELD;
 829
 830                 ret = sbc_check_prot(dev, cmd, cdb[1] >> 5, sectors, false);
 831                 if (ret)
 832                         return ret;
 833
 834                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 835                 cmd->execute_cmd = sbc_execute_rw;
 836                 break;
 837         case READ_12:
 838                 sectors = transport_get_sectors_12(cdb);
 839                 cmd->t_task_lba = transport_lba_32(cdb);
 840
 841                 if (sbc_check_dpofua(dev, cmd, cdb))
 842                         return TCM_INVALID_CDB_FIELD;
 843
 844                 ret = sbc_check_prot(dev, cmd, cdb[1] >> 5, sectors, false);
 845                 if (ret)
 846                         return ret;
 847
 848                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 849                 cmd->execute_cmd = sbc_execute_rw;
 850                 break;
 851         case READ_16:
 852                 sectors = transport_get_sectors_16(cdb);
 853                 cmd->t_task_lba = transport_lba_64(cdb);
 854
 855                 if (sbc_check_dpofua(dev, cmd, cdb))
 856                         return TCM_INVALID_CDB_FIELD;
 857
 858                 ret = sbc_check_prot(dev, cmd, cdb[1] >> 5, sectors, false);
 859                 if (ret)
 860                         return ret;
 861
 862                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 863                 cmd->execute_cmd = sbc_execute_rw;
 864                 break;
 865         case WRITE_6:
 866                 sectors = transport_get_sectors_6(cdb);
 867                 cmd->t_task_lba = transport_lba_21(cdb);
 868                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 869                 cmd->execute_cmd = sbc_execute_rw;
 870                 break;
 871         case WRITE_10:
 872         case WRITE_VERIFY:
 873                 sectors = transport_get_sectors_10(cdb);
 874                 cmd->t_task_lba = transport_lba_32(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, true);
 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_12:
 887                 sectors = transport_get_sectors_12(cdb);
 888                 cmd->t_task_lba = transport_lba_32(cdb);
 889
 890                 if (sbc_check_dpofua(dev, cmd, cdb))
 891                         return TCM_INVALID_CDB_FIELD;
 892
 893                 ret = sbc_check_prot(dev, cmd, cdb[1] >> 5, sectors, true);
 894                 if (ret)
 895                         return ret;
 896
 897                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 898                 cmd->execute_cmd = sbc_execute_rw;
 899                 break;
 900         case WRITE_16:
 901         case WRITE_VERIFY_16:
 902                 sectors = transport_get_sectors_16(cdb);
 903                 cmd->t_task_lba = transport_lba_64(cdb);
 904
 905                 if (sbc_check_dpofua(dev, cmd, cdb))
 906                         return TCM_INVALID_CDB_FIELD;
 907
 908                 ret = sbc_check_prot(dev, cmd, cdb[1] >> 5, sectors, true);
 909                 if (ret)
 910                         return ret;
 911
 912                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 913                 cmd->execute_cmd = sbc_execute_rw;
 914                 break;
 915         case XDWRITEREAD_10:
 916                 if (cmd->data_direction != DMA_TO_DEVICE ||
 917                     !(cmd->se_cmd_flags & SCF_BIDI))
 918                         return TCM_INVALID_CDB_FIELD;
 919                 sectors = transport_get_sectors_10(cdb);
 920
 921                 if (sbc_check_dpofua(dev, cmd, cdb))
 922                         return TCM_INVALID_CDB_FIELD;
 923
 924                 cmd->t_task_lba = transport_lba_32(cdb);
 925                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 926
 927                 /*
 928                  * Setup BIDI XOR callback to be run after I/O completion.
 929                  */
 930                 cmd->execute_cmd = sbc_execute_rw;
 931                 cmd->transport_complete_callback = &xdreadwrite_callback;
 932                 break;
 933         case VARIABLE_LENGTH_CMD:
 934         {
 935                 u16 service_action = get_unaligned_be16(&cdb[8]);
 936                 switch (service_action) {
 937                 case XDWRITEREAD_32:
 938                         sectors = transport_get_sectors_32(cdb);
 939
 940                         if (sbc_check_dpofua(dev, cmd, cdb))
 941                                 return TCM_INVALID_CDB_FIELD;
 942                         /*
 943                          * Use WRITE_32 and READ_32 opcodes for the emulated
 944                          * XDWRITE_READ_32 logic.
 945                          */
 946                         cmd->t_task_lba = transport_lba_64_ext(cdb);
 947                         cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 948
 949                         /*
 950                          * Setup BIDI XOR callback to be run during after I/O
 951                          * completion.
 952                          */
 953                         cmd->execute_cmd = sbc_execute_rw;
 954                         cmd->transport_complete_callback = &xdreadwrite_callback;
 955                         break;
 956                 case WRITE_SAME_32:
 957                         sectors = transport_get_sectors_32(cdb);
 958                         if (!sectors) {
 959                                 pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not"
 960                                        " supported\n");
 961                                 return TCM_INVALID_CDB_FIELD;
 962                         }
 963
 964                         size = sbc_get_size(cmd, 1);
 965                         cmd->t_task_lba = get_unaligned_be64(&cdb[12]);
 966
 967                         ret = sbc_setup_write_same(cmd, cdb[10], ops);
 968                         if (ret)
 969                                 return ret;
 970                         break;
 971                 default:
 972                         pr_err("VARIABLE_LENGTH_CMD service action"
 973                                 " 0x%04x not supported\n", service_action);
 974                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 975                 }
 976                 break;
 977         }
 978         case COMPARE_AND_WRITE:
 979                 if (!dev->dev_attrib.emulate_caw) {
 980                         pr_err_ratelimited("se_device %s/%s (vpd_unit_serial %s) reject COMPARE_AND_WRITE\n",
 981                                            dev->se_hba->backend->ops->name,
 982                                            config_item_name(&dev->dev_group.cg_item),
 983                                            dev->t10_wwn.unit_serial);
 984                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 985                 }
 986                 sectors = cdb[13];
 987                 /*
 988                  * Currently enforce COMPARE_AND_WRITE for a single sector
 989                  */
 990                 if (sectors > 1) {
 991                         pr_err("COMPARE_AND_WRITE contains NoLB: %u greater"
 992                                " than 1\n", sectors);
 993                         return TCM_INVALID_CDB_FIELD;
 994                 }
 995                 if (sbc_check_dpofua(dev, cmd, cdb))
 996                         return TCM_INVALID_CDB_FIELD;
 997
 998                 /*
 999                  * Double size because we have two buffers, note that
1000                  * zero is not an error..
1001                  */
1002                 size = 2 * sbc_get_size(cmd, sectors);
1003                 cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
1004                 cmd->t_task_nolb = sectors;
1005                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB | SCF_COMPARE_AND_WRITE;
1006                 cmd->execute_cmd = sbc_compare_and_write;
1007                 cmd->transport_complete_callback = compare_and_write_callback;
1008                 break;
1009         case READ_CAPACITY:
1010                 size = READ_CAP_LEN;
1011                 cmd->execute_cmd = sbc_emulate_readcapacity;
1012                 break;
1013         case SERVICE_ACTION_IN_16:
1014                 switch (cmd->t_task_cdb[1] & 0x1f) {
1015                 case SAI_READ_CAPACITY_16:
1016                         cmd->execute_cmd = sbc_emulate_readcapacity_16;
1017                         break;
1018                 case SAI_REPORT_REFERRALS:
1019                         cmd->execute_cmd = target_emulate_report_referrals;
1020                         break;
1021                 default:
1022                         pr_err("Unsupported SA: 0x%02x\n",
1023                                 cmd->t_task_cdb[1] & 0x1f);
1024                         return TCM_INVALID_CDB_FIELD;
1025                 }
1026                 size = get_unaligned_be32(&cdb[10]);
1027                 break;
1028         case SYNCHRONIZE_CACHE:
1029         case SYNCHRONIZE_CACHE_16:
1030                 if (cdb[0] == SYNCHRONIZE_CACHE) {
1031                         sectors = transport_get_sectors_10(cdb);
1032                         cmd->t_task_lba = transport_lba_32(cdb);
1033                 } else {
1034                         sectors = transport_get_sectors_16(cdb);
1035                         cmd->t_task_lba = transport_lba_64(cdb);
1036                 }
1037                 if (ops->execute_sync_cache) {
1038                         cmd->execute_cmd = ops->execute_sync_cache;
1039                         goto check_lba;
1040                 }
1041                 size = 0;
1042                 cmd->execute_cmd = sbc_emulate_noop;
1043                 break;
1044         case UNMAP:
1045                 if (!ops->execute_unmap)
1046                         return TCM_UNSUPPORTED_SCSI_OPCODE;
1047
1048                 if (!dev->dev_attrib.emulate_tpu) {
1049                         pr_err("Got UNMAP, but backend device has"
1050                                " emulate_tpu disabled\n");
1051                         return TCM_UNSUPPORTED_SCSI_OPCODE;
1052                 }
1053                 size = get_unaligned_be16(&cdb[7]);
1054                 cmd->execute_cmd = sbc_execute_unmap;
1055                 break;
1056         case WRITE_SAME_16:
1057                 sectors = transport_get_sectors_16(cdb);
1058                 if (!sectors) {
1059                         pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
1060                         return TCM_INVALID_CDB_FIELD;
1061                 }
1062
1063                 size = sbc_get_size(cmd, 1);
1064                 cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
1065
1066                 ret = sbc_setup_write_same(cmd, cdb[1], ops);
1067                 if (ret)
1068                         return ret;
1069                 break;
1070         case WRITE_SAME:
1071                 sectors = transport_get_sectors_10(cdb);
1072                 if (!sectors) {
1073                         pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
1074                         return TCM_INVALID_CDB_FIELD;
1075                 }
1076
1077                 size = sbc_get_size(cmd, 1);
1078                 cmd->t_task_lba = get_unaligned_be32(&cdb[2]);
1079
1080                 /*
1081                  * Follow sbcr26 with WRITE_SAME (10) and check for the existence
1082                  * of byte 1 bit 3 UNMAP instead of original reserved field
1083                  */
1084                 ret = sbc_setup_write_same(cmd, cdb[1], ops);
1085                 if (ret)
1086                         return ret;
1087                 break;
1088         case VERIFY:
1089         case VERIFY_16:
1090                 size = 0;
1091                 if (cdb[0] == VERIFY) {
1092                         sectors = transport_get_sectors_10(cdb);
1093                         cmd->t_task_lba = transport_lba_32(cdb);
1094                 } else {
1095                         sectors = transport_get_sectors_16(cdb);
1096                         cmd->t_task_lba = transport_lba_64(cdb);
1097                 }
1098                 cmd->execute_cmd = sbc_emulate_noop;
1099                 goto check_lba;
1100         case REZERO_UNIT:
1101         case SEEK_6:
1102         case SEEK_10:
1103                 /*
1104                  * There are still clients out there which use these old SCSI-2
1105                  * commands. This mainly happens when running VMs with legacy
1106                  * guest systems, connected via SCSI command pass-through to
1107                  * iSCSI targets. Make them happy and return status GOOD.
1108                  */
1109                 size = 0;
1110                 cmd->execute_cmd = sbc_emulate_noop;
1111                 break;
1112         case START_STOP:
1113                 size = 0;
1114                 cmd->execute_cmd = sbc_emulate_startstop;
1115                 break;
1116         default:
1117                 ret = spc_parse_cdb(cmd, &size);
1118                 if (ret)
1119                         return ret;
1120         }
1121
1122         /* reject any command that we don't have a handler for */
1123         if (!cmd->execute_cmd)
1124                 return TCM_UNSUPPORTED_SCSI_OPCODE;
1125
1126         if (cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
1127                 unsigned long long end_lba;
1128 check_lba:
1129                 end_lba = dev->transport->get_blocks(dev) + 1;
1130                 if (((cmd->t_task_lba + sectors) < cmd->t_task_lba) ||
1131                     ((cmd->t_task_lba + sectors) > end_lba)) {
1132                         pr_err("cmd exceeds last lba %llu "
1133                                 "(lba %llu, sectors %u)\n",
1134                                 end_lba, cmd->t_task_lba, sectors);
1135                         return TCM_ADDRESS_OUT_OF_RANGE;
1136                 }
1137
1138                 if (!(cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE))
1139                         size = sbc_get_size(cmd, sectors);
1140         }
1141
1142         return target_cmd_size_check(cmd, size);
1143 }
1144 EXPORT_SYMBOL(sbc_parse_cdb);
1145
1146 u32 sbc_get_device_type(struct se_device *dev)
1147 {
1148         return TYPE_DISK;
1149 }
1150 EXPORT_SYMBOL(sbc_get_device_type);
1151
1152 static sense_reason_t
1153 sbc_execute_unmap(struct se_cmd *cmd)
1154 {
1155         struct sbc_ops *ops = cmd->protocol_data;
1156         struct se_device *dev = cmd->se_dev;
1157         unsigned char *buf, *ptr = NULL;
1158         sector_t lba;
1159         int size;
1160         u32 range;
1161         sense_reason_t ret = 0;
1162         int dl, bd_dl;
1163
1164         /* We never set ANC_SUP */
1165         if (cmd->t_task_cdb[1])
1166                 return TCM_INVALID_CDB_FIELD;
1167
1168         if (cmd->data_length == 0) {
1169                 target_complete_cmd(cmd, SAM_STAT_GOOD);
1170                 return 0;
1171         }
1172
1173         if (cmd->data_length < 8) {
1174                 pr_warn("UNMAP parameter list length %u too small\n",
1175                         cmd->data_length);
1176                 return TCM_PARAMETER_LIST_LENGTH_ERROR;
1177         }
1178
1179         buf = transport_kmap_data_sg(cmd);
1180         if (!buf)
1181                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1182
1183         dl = get_unaligned_be16(&buf[0]);
1184         bd_dl = get_unaligned_be16(&buf[2]);
1185
1186         size = cmd->data_length - 8;
1187         if (bd_dl > size)
1188                 pr_warn("UNMAP parameter list length %u too small, ignoring bd_dl %u\n",
1189                         cmd->data_length, bd_dl);
1190         else
1191                 size = bd_dl;
1192
1193         if (size / 16 > dev->dev_attrib.max_unmap_block_desc_count) {
1194                 ret = TCM_INVALID_PARAMETER_LIST;
1195                 goto err;
1196         }
1197
1198         /* First UNMAP block descriptor starts at 8 byte offset */
1199         ptr = &buf[8];
1200         pr_debug("UNMAP: Sub: %s Using dl: %u bd_dl: %u size: %u"
1201                 " ptr: %p\n", dev->transport->name, dl, bd_dl, size, ptr);
1202
1203         while (size >= 16) {
1204                 lba = get_unaligned_be64(&ptr[0]);
1205                 range = get_unaligned_be32(&ptr[8]);
1206                 pr_debug("UNMAP: Using lba: %llu and range: %u\n",
1207                                  (unsigned long long)lba, range);
1208
1209                 if (range > dev->dev_attrib.max_unmap_lba_count) {
1210                         ret = TCM_INVALID_PARAMETER_LIST;
1211                         goto err;
1212                 }
1213
1214                 if (lba + range > dev->transport->get_blocks(dev) + 1) {
1215                         ret = TCM_ADDRESS_OUT_OF_RANGE;
1216                         goto err;
1217                 }
1218
1219                 if (range) {
1220                         ret = ops->execute_unmap(cmd, lba, range);
1221                         if (ret)
1222                                 goto err;
1223                 }
1224
1225                 ptr += 16;
1226                 size -= 16;
1227         }
1228
1229 err:
1230         transport_kunmap_data_sg(cmd);
1231         if (!ret)
1232                 target_complete_cmd(cmd, GOOD);
1233         return ret;
1234 }
1235
1236 void
1237 sbc_dif_generate(struct se_cmd *cmd)
1238 {
1239         struct se_device *dev = cmd->se_dev;
1240         struct t10_pi_tuple *sdt;
1241         struct scatterlist *dsg = cmd->t_data_sg, *psg;
1242         sector_t sector = cmd->t_task_lba;
1243         void *daddr, *paddr;
1244         int i, j, offset = 0;
1245         unsigned int block_size = dev->dev_attrib.block_size;
1246
1247         for_each_sg(cmd->t_prot_sg, psg, cmd->t_prot_nents, i) {
1248                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1249                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1250
1251                 for (j = 0; j < psg->length;
1252                                 j += sizeof(*sdt)) {
1253                         __u16 crc;
1254                         unsigned int avail;
1255
1256                         if (offset >= dsg->length) {
1257                                 offset -= dsg->length;
1258                                 kunmap_atomic(daddr - dsg->offset);
1259                                 dsg = sg_next(dsg);
1260                                 if (!dsg) {
1261                                         kunmap_atomic(paddr - psg->offset);
1262                                         return;
1263                                 }
1264                                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1265                         }
1266
1267                         sdt = paddr + j;
1268                         avail = min(block_size, dsg->length - offset);
1269                         crc = crc_t10dif(daddr + offset, avail);
1270                         if (avail < block_size) {
1271                                 kunmap_atomic(daddr - dsg->offset);
1272                                 dsg = sg_next(dsg);
1273                                 if (!dsg) {
1274                                         kunmap_atomic(paddr - psg->offset);
1275                                         return;
1276                                 }
1277                                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1278                                 offset = block_size - avail;
1279                                 crc = crc_t10dif_update(crc, daddr, offset);
1280                         } else {
1281                                 offset += block_size;
1282                         }
1283
1284                         sdt->guard_tag = cpu_to_be16(crc);
1285                         if (cmd->prot_type == TARGET_DIF_TYPE1_PROT)
1286                                 sdt->ref_tag = cpu_to_be32(sector & 0xffffffff);
1287                         sdt->app_tag = 0;
1288
1289                         pr_debug("DIF %s INSERT sector: %llu guard_tag: 0x%04x"
1290                                  " app_tag: 0x%04x ref_tag: %u\n",
1291                                  (cmd->data_direction == DMA_TO_DEVICE) ?
1292                                  "WRITE" : "READ", (unsigned long long)sector,
1293                                  sdt->guard_tag, sdt->app_tag,
1294                                  be32_to_cpu(sdt->ref_tag));
1295
1296                         sector++;
1297                 }
1298
1299                 kunmap_atomic(daddr - dsg->offset);
1300                 kunmap_atomic(paddr - psg->offset);
1301         }
1302 }
1303
1304 static sense_reason_t
1305 sbc_dif_v1_verify(struct se_cmd *cmd, struct t10_pi_tuple *sdt,
1306                   __u16 crc, sector_t sector, unsigned int ei_lba)
1307 {
1308         __be16 csum;
1309
1310         if (!(cmd->prot_checks & TARGET_DIF_CHECK_GUARD))
1311                 goto check_ref;
1312
1313         csum = cpu_to_be16(crc);
1314
1315         if (sdt->guard_tag != csum) {
1316                 pr_err("DIFv1 checksum failed on sector %llu guard tag 0x%04x"
1317                         " csum 0x%04x\n", (unsigned long long)sector,
1318                         be16_to_cpu(sdt->guard_tag), be16_to_cpu(csum));
1319                 return TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED;
1320         }
1321
1322 check_ref:
1323         if (!(cmd->prot_checks & TARGET_DIF_CHECK_REFTAG))
1324                 return 0;
1325
1326         if (cmd->prot_type == TARGET_DIF_TYPE1_PROT &&
1327             be32_to_cpu(sdt->ref_tag) != (sector & 0xffffffff)) {
1328                 pr_err("DIFv1 Type 1 reference failed on sector: %llu tag: 0x%08x"
1329                        " sector MSB: 0x%08x\n", (unsigned long long)sector,
1330                        be32_to_cpu(sdt->ref_tag), (u32)(sector & 0xffffffff));
1331                 return TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;
1332         }
1333
1334         if (cmd->prot_type == TARGET_DIF_TYPE2_PROT &&
1335             be32_to_cpu(sdt->ref_tag) != ei_lba) {
1336                 pr_err("DIFv1 Type 2 reference failed on sector: %llu tag: 0x%08x"
1337                        " ei_lba: 0x%08x\n", (unsigned long long)sector,
1338                         be32_to_cpu(sdt->ref_tag), ei_lba);
1339                 return TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;
1340         }
1341
1342         return 0;
1343 }
1344
1345 void sbc_dif_copy_prot(struct se_cmd *cmd, unsigned int sectors, bool read,
1346                        struct scatterlist *sg, int sg_off)
1347 {
1348         struct se_device *dev = cmd->se_dev;
1349         struct scatterlist *psg;
1350         void *paddr, *addr;
1351         unsigned int i, len, left;
1352         unsigned int offset = sg_off;
1353
1354         if (!sg)
1355                 return;
1356
1357         left = sectors * dev->prot_length;
1358
1359         for_each_sg(cmd->t_prot_sg, psg, cmd->t_prot_nents, i) {
1360                 unsigned int psg_len, copied = 0;
1361
1362                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1363                 psg_len = min(left, psg->length);
1364                 while (psg_len) {
1365                         len = min(psg_len, sg->length - offset);
1366                         addr = kmap_atomic(sg_page(sg)) + sg->offset + offset;
1367
1368                         if (read)
1369                                 memcpy(paddr + copied, addr, len);
1370                         else
1371                                 memcpy(addr, paddr + copied, len);
1372
1373                         left -= len;
1374                         offset += len;
1375                         copied += len;
1376                         psg_len -= len;
1377
1378                         kunmap_atomic(addr - sg->offset - offset);
1379
1380                         if (offset >= sg->length) {
1381                                 sg = sg_next(sg);
1382                                 offset = 0;
1383                         }
1384                 }
1385                 kunmap_atomic(paddr - psg->offset);
1386         }
1387 }
1388 EXPORT_SYMBOL(sbc_dif_copy_prot);
1389
1390 sense_reason_t
1391 sbc_dif_verify(struct se_cmd *cmd, sector_t start, unsigned int sectors,
1392                unsigned int ei_lba, struct scatterlist *psg, int psg_off)
1393 {
1394         struct se_device *dev = cmd->se_dev;
1395         struct t10_pi_tuple *sdt;
1396         struct scatterlist *dsg = cmd->t_data_sg;
1397         sector_t sector = start;
1398         void *daddr, *paddr;
1399         int i;
1400         sense_reason_t rc;
1401         int dsg_off = 0;
1402         unsigned int block_size = dev->dev_attrib.block_size;
1403
1404         for (; psg && sector < start + sectors; psg = sg_next(psg)) {
1405                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1406                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1407
1408                 for (i = psg_off; i < psg->length &&
1409                                 sector < start + sectors;
1410                                 i += sizeof(*sdt)) {
1411                         __u16 crc;
1412                         unsigned int avail;
1413
1414                         if (dsg_off >= dsg->length) {
1415                                 dsg_off -= dsg->length;
1416                                 kunmap_atomic(daddr - dsg->offset);
1417                                 dsg = sg_next(dsg);
1418                                 if (!dsg) {
1419                                         kunmap_atomic(paddr - psg->offset);
1420                                         return 0;
1421                                 }
1422                                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1423                         }
1424
1425                         sdt = paddr + i;
1426
1427                         pr_debug("DIF READ sector: %llu guard_tag: 0x%04x"
1428                                  " app_tag: 0x%04x ref_tag: %u\n",
1429                                  (unsigned long long)sector, sdt->guard_tag,
1430                                  sdt->app_tag, be32_to_cpu(sdt->ref_tag));
1431
1432                         if (sdt->app_tag == T10_PI_APP_ESCAPE) {
1433                                 dsg_off += block_size;
1434                                 goto next;
1435                         }
1436
1437                         avail = min(block_size, dsg->length - dsg_off);
1438                         crc = crc_t10dif(daddr + dsg_off, avail);
1439                         if (avail < block_size) {
1440                                 kunmap_atomic(daddr - dsg->offset);
1441                                 dsg = sg_next(dsg);
1442                                 if (!dsg) {
1443                                         kunmap_atomic(paddr - psg->offset);
1444                                         return 0;
1445                                 }
1446                                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1447                                 dsg_off = block_size - avail;
1448                                 crc = crc_t10dif_update(crc, daddr, dsg_off);
1449                         } else {
1450                                 dsg_off += block_size;
1451                         }
1452
1453                         rc = sbc_dif_v1_verify(cmd, sdt, crc, sector, ei_lba);
1454                         if (rc) {
1455                                 kunmap_atomic(daddr - dsg->offset);
1456                                 kunmap_atomic(paddr - psg->offset);
1457                                 cmd->bad_sector = sector;
1458                                 return rc;
1459                         }
1460 next:
1461                         sector++;
1462                         ei_lba++;
1463                 }
1464
1465                 psg_off = 0;
1466                 kunmap_atomic(daddr - dsg->offset);
1467                 kunmap_atomic(paddr - psg->offset);
1468         }
1469
1470         return 0;
1471 }
1472 EXPORT_SYMBOL(sbc_dif_verify);