drivers/target/target_core_sbc.c

   1 /*
   2  * SCSI Block Commands (SBC) parsing and emulation.
   3  *
   4  * (c) Copyright 2002-2013 Datera, Inc.
   5  *
   6  * Nicholas A. Bellinger <nab@kernel.org>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  21  */
  22
  23 #include <linux/kernel.h>
  24 #include <linux/module.h>
  25 #include <linux/ratelimit.h>
  26 #include <linux/crc-t10dif.h>
  27 #include <asm/unaligned.h>
  28 #include <scsi/scsi_proto.h>
  29 #include <scsi/scsi_tcq.h>
  30
  31 #include <target/target_core_base.h>
  32 #include <target/target_core_backend.h>
  33 #include <target/target_core_fabric.h>
  34
  35 #include "target_core_internal.h"
  36 #include "target_core_ua.h"
  37 #include "target_core_alua.h"
  38
  39 static sense_reason_t
  40 sbc_check_prot(struct se_device *, struct se_cmd *, unsigned char, u32, bool);
  41 static sense_reason_t sbc_execute_unmap(struct se_cmd *cmd);
  42
  43 static sense_reason_t
  44 sbc_emulate_readcapacity(struct se_cmd *cmd)
  45 {
  46         struct se_device *dev = cmd->se_dev;
  47         unsigned char *cdb = cmd->t_task_cdb;
  48         unsigned long long blocks_long = dev->transport->get_blocks(dev);
  49         unsigned char *rbuf;
  50         unsigned char buf[8];
  51         u32 blocks;
  52
  53         /*
  54          * SBC-2 says:
  55          *   If the PMI bit is set to zero and the LOGICAL BLOCK
  56          *   ADDRESS field is not set to zero, the device server shall
  57          *   terminate the command with CHECK CONDITION status with
  58          *   the sense key set to ILLEGAL REQUEST and the additional
  59          *   sense code set to INVALID FIELD IN CDB.
  60          *
  61          * In SBC-3, these fields are obsolete, but some SCSI
  62          * compliance tests actually check this, so we might as well
  63          * follow SBC-2.
  64          */
  65         if (!(cdb[8] & 1) && !!(cdb[2] | cdb[3] | cdb[4] | cdb[5]))
  66                 return TCM_INVALID_CDB_FIELD;
  67
  68         if (blocks_long >= 0x00000000ffffffff)
  69                 blocks = 0xffffffff;
  70         else
  71                 blocks = (u32)blocks_long;
  72
  73         buf[0] = (blocks >> 24) & 0xff;
  74         buf[1] = (blocks >> 16) & 0xff;
  75         buf[2] = (blocks >> 8) & 0xff;
  76         buf[3] = blocks & 0xff;
  77         buf[4] = (dev->dev_attrib.block_size >> 24) & 0xff;
  78         buf[5] = (dev->dev_attrib.block_size >> 16) & 0xff;
  79         buf[6] = (dev->dev_attrib.block_size >> 8) & 0xff;
  80         buf[7] = dev->dev_attrib.block_size & 0xff;
  81
  82         rbuf = transport_kmap_data_sg(cmd);
  83         if (rbuf) {
  84                 memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length));
  85                 transport_kunmap_data_sg(cmd);
  86         }
  87
  88         target_complete_cmd_with_length(cmd, GOOD, 8);
  89         return 0;
  90 }
  91
  92 static sense_reason_t
  93 sbc_emulate_readcapacity_16(struct se_cmd *cmd)
  94 {
  95         struct se_device *dev = cmd->se_dev;
  96         struct se_session *sess = cmd->se_sess;
  97         int pi_prot_type = dev->dev_attrib.pi_prot_type;
  98
  99         unsigned char *rbuf;
 100         unsigned char buf[32];
 101         unsigned long long blocks = dev->transport->get_blocks(dev);
 102
 103         memset(buf, 0, sizeof(buf));
 104         buf[0] = (blocks >> 56) & 0xff;
 105         buf[1] = (blocks >> 48) & 0xff;
 106         buf[2] = (blocks >> 40) & 0xff;
 107         buf[3] = (blocks >> 32) & 0xff;
 108         buf[4] = (blocks >> 24) & 0xff;
 109         buf[5] = (blocks >> 16) & 0xff;
 110         buf[6] = (blocks >> 8) & 0xff;
 111         buf[7] = blocks & 0xff;
 112         buf[8] = (dev->dev_attrib.block_size >> 24) & 0xff;
 113         buf[9] = (dev->dev_attrib.block_size >> 16) & 0xff;
 114         buf[10] = (dev->dev_attrib.block_size >> 8) & 0xff;
 115         buf[11] = dev->dev_attrib.block_size & 0xff;
 116         /*
 117          * Set P_TYPE and PROT_EN bits for DIF support
 118          */
 119         if (sess->sup_prot_ops & (TARGET_PROT_DIN_PASS | TARGET_PROT_DOUT_PASS)) {
 120                 /*
 121                  * Only override a device's pi_prot_type if no T10-PI is
 122                  * available, and sess_prot_type has been explicitly enabled.
 123                  */
 124                 if (!pi_prot_type)
 125                         pi_prot_type = sess->sess_prot_type;
 126
 127                 if (pi_prot_type)
 128                         buf[12] = (pi_prot_type - 1) << 1 | 0x1;
 129         }
 130
 131         if (dev->transport->get_lbppbe)
 132                 buf[13] = dev->transport->get_lbppbe(dev) & 0x0f;
 133
 134         if (dev->transport->get_alignment_offset_lbas) {
 135                 u16 lalba = dev->transport->get_alignment_offset_lbas(dev);
 136                 buf[14] = (lalba >> 8) & 0x3f;
 137                 buf[15] = lalba & 0xff;
 138         }
 139
 140         /*
 141          * Set Thin Provisioning Enable bit following sbc3r22 in section
 142          * READ CAPACITY (16) byte 14 if emulate_tpu or emulate_tpws is enabled.
 143          */
 144         if (dev->dev_attrib.emulate_tpu || dev->dev_attrib.emulate_tpws) {
 145                 buf[14] |= 0x80;
 146
 147                 /*
 148                  * LBPRZ signifies that zeroes will be read back from an LBA after
 149                  * an UNMAP or WRITE SAME w/ unmap bit (sbc3r36 5.16.2)
 150                  */
 151                 if (dev->dev_attrib.unmap_zeroes_data)
 152                         buf[14] |= 0x40;
 153         }
 154
 155         rbuf = transport_kmap_data_sg(cmd);
 156         if (rbuf) {
 157                 memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length));
 158                 transport_kunmap_data_sg(cmd);
 159         }
 160
 161         target_complete_cmd_with_length(cmd, GOOD, 32);
 162         return 0;
 163 }
 164
 165 static sense_reason_t
 166 sbc_emulate_startstop(struct se_cmd *cmd)
 167 {
 168         unsigned char *cdb = cmd->t_task_cdb;
 169
 170         /*
 171          * See sbc3r36 section 5.25
 172          * Immediate bit should be set since there is nothing to complete
 173          * POWER CONDITION MODIFIER 0h
 174          */
 175         if (!(cdb[1] & 1) || cdb[2] || cdb[3])
 176                 return TCM_INVALID_CDB_FIELD;
 177
 178         /*
 179          * See sbc3r36 section 5.25
 180          * POWER CONDITION 0h START_VALID - process START and LOEJ
 181          */
 182         if (cdb[4] >> 4 & 0xf)
 183                 return TCM_INVALID_CDB_FIELD;
 184
 185         /*
 186          * See sbc3r36 section 5.25
 187          * LOEJ 0h - nothing to load or unload
 188          * START 1h - we are ready
 189          */
 190         if (!(cdb[4] & 1) || (cdb[4] & 2) || (cdb[4] & 4))
 191                 return TCM_INVALID_CDB_FIELD;
 192
 193         target_complete_cmd(cmd, SAM_STAT_GOOD);
 194         return 0;
 195 }
 196
 197 sector_t sbc_get_write_same_sectors(struct se_cmd *cmd)
 198 {
 199         u32 num_blocks;
 200
 201         if (cmd->t_task_cdb[0] == WRITE_SAME)
 202                 num_blocks = get_unaligned_be16(&cmd->t_task_cdb[7]);
 203         else if (cmd->t_task_cdb[0] == WRITE_SAME_16)
 204                 num_blocks = get_unaligned_be32(&cmd->t_task_cdb[10]);
 205         else /* WRITE_SAME_32 via VARIABLE_LENGTH_CMD */
 206                 num_blocks = get_unaligned_be32(&cmd->t_task_cdb[28]);
 207
 208         /*
 209          * Use the explicit range when non zero is supplied, otherwise calculate
 210          * the remaining range based on ->get_blocks() - starting LBA.
 211          */
 212         if (num_blocks)
 213                 return num_blocks;
 214
 215         return cmd->se_dev->transport->get_blocks(cmd->se_dev) -
 216                 cmd->t_task_lba + 1;
 217 }
 218 EXPORT_SYMBOL(sbc_get_write_same_sectors);
 219
 220 static sense_reason_t
 221 sbc_execute_write_same_unmap(struct se_cmd *cmd)
 222 {
 223         struct sbc_ops *ops = cmd->protocol_data;
 224         sector_t nolb = sbc_get_write_same_sectors(cmd);
 225         sense_reason_t ret;
 226
 227         if (nolb) {
 228                 ret = ops->execute_unmap(cmd, cmd->t_task_lba, nolb);
 229                 if (ret)
 230                         return ret;
 231         }
 232
 233         target_complete_cmd(cmd, GOOD);
 234         return 0;
 235 }
 236
 237 static sense_reason_t
 238 sbc_emulate_noop(struct se_cmd *cmd)
 239 {
 240         target_complete_cmd(cmd, GOOD);
 241         return 0;
 242 }
 243
 244 static inline u32 sbc_get_size(struct se_cmd *cmd, u32 sectors)
 245 {
 246         return cmd->se_dev->dev_attrib.block_size * sectors;
 247 }
 248
 249 static inline u32 transport_get_sectors_6(unsigned char *cdb)
 250 {
 251         /*
 252          * Use 8-bit sector value.  SBC-3 says:
 253          *
 254          *   A TRANSFER LENGTH field set to zero specifies that 256
 255          *   logical blocks shall be written.  Any other value
 256          *   specifies the number of logical blocks that shall be
 257          *   written.
 258          */
 259         return cdb[4] ? : 256;
 260 }
 261
 262 static inline u32 transport_get_sectors_10(unsigned char *cdb)
 263 {
 264         return (u32)(cdb[7] << 8) + cdb[8];
 265 }
 266
 267 static inline u32 transport_get_sectors_12(unsigned char *cdb)
 268 {
 269         return (u32)(cdb[6] << 24) + (cdb[7] << 16) + (cdb[8] << 8) + cdb[9];
 270 }
 271
 272 static inline u32 transport_get_sectors_16(unsigned char *cdb)
 273 {
 274         return (u32)(cdb[10] << 24) + (cdb[11] << 16) +
 275                     (cdb[12] << 8) + cdb[13];
 276 }
 277
 278 /*
 279  * Used for VARIABLE_LENGTH_CDB WRITE_32 and READ_32 variants
 280  */
 281 static inline u32 transport_get_sectors_32(unsigned char *cdb)
 282 {
 283         return (u32)(cdb[28] << 24) + (cdb[29] << 16) +
 284                     (cdb[30] << 8) + cdb[31];
 285
 286 }
 287
 288 static inline u32 transport_lba_21(unsigned char *cdb)
 289 {
 290         return ((cdb[1] & 0x1f) << 16) | (cdb[2] << 8) | cdb[3];
 291 }
 292
 293 static inline u32 transport_lba_32(unsigned char *cdb)
 294 {
 295         return (cdb[2] << 24) | (cdb[3] << 16) | (cdb[4] << 8) | cdb[5];
 296 }
 297
 298 static inline unsigned long long transport_lba_64(unsigned char *cdb)
 299 {
 300         unsigned int __v1, __v2;
 301
 302         __v1 = (cdb[2] << 24) | (cdb[3] << 16) | (cdb[4] << 8) | cdb[5];
 303         __v2 = (cdb[6] << 24) | (cdb[7] << 16) | (cdb[8] << 8) | cdb[9];
 304
 305         return ((unsigned long long)__v2) | (unsigned long long)__v1 << 32;
 306 }
 307
 308 /*
 309  * For VARIABLE_LENGTH_CDB w/ 32 byte extended CDBs
 310  */
 311 static inline unsigned long long transport_lba_64_ext(unsigned char *cdb)
 312 {
 313         unsigned int __v1, __v2;
 314
 315         __v1 = (cdb[12] << 24) | (cdb[13] << 16) | (cdb[14] << 8) | cdb[15];
 316         __v2 = (cdb[16] << 24) | (cdb[17] << 16) | (cdb[18] << 8) | cdb[19];
 317
 318         return ((unsigned long long)__v2) | (unsigned long long)__v1 << 32;
 319 }
 320
 321 static sense_reason_t
 322 sbc_setup_write_same(struct se_cmd *cmd, unsigned char flags, struct sbc_ops *ops)
 323 {
 324         struct se_device *dev = cmd->se_dev;
 325         sector_t end_lba = dev->transport->get_blocks(dev) + 1;
 326         unsigned int sectors = sbc_get_write_same_sectors(cmd);
 327         sense_reason_t ret;
 328
 329         if ((flags & 0x04) || (flags & 0x02)) {
 330                 pr_err("WRITE_SAME PBDATA and LBDATA"
 331                         " bits not supported for Block Discard"
 332                         " Emulation\n");
 333                 return TCM_UNSUPPORTED_SCSI_OPCODE;
 334         }
 335         if (sectors > cmd->se_dev->dev_attrib.max_write_same_len) {
 336                 pr_warn("WRITE_SAME sectors: %u exceeds max_write_same_len: %u\n",
 337                         sectors, cmd->se_dev->dev_attrib.max_write_same_len);
 338                 return TCM_INVALID_CDB_FIELD;
 339         }
 340         /*
 341          * Sanity check for LBA wrap and request past end of device.
 342          */
 343         if (((cmd->t_task_lba + sectors) < cmd->t_task_lba) ||
 344             ((cmd->t_task_lba + sectors) > end_lba)) {
 345                 pr_err("WRITE_SAME exceeds last lba %llu (lba %llu, sectors %u)\n",
 346                        (unsigned long long)end_lba, cmd->t_task_lba, sectors);
 347                 return TCM_ADDRESS_OUT_OF_RANGE;
 348         }
 349
 350         /* We always have ANC_SUP == 0 so setting ANCHOR is always an error */
 351         if (flags & 0x10) {
 352                 pr_warn("WRITE SAME with ANCHOR not supported\n");
 353                 return TCM_INVALID_CDB_FIELD;
 354         }
 355         /*
 356          * Special case for WRITE_SAME w/ UNMAP=1 that ends up getting
 357          * translated into block discard requests within backend code.
 358          */
 359         if (flags & 0x08) {
 360                 if (!ops->execute_unmap)
 361                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 362
 363                 if (!dev->dev_attrib.emulate_tpws) {
 364                         pr_err("Got WRITE_SAME w/ UNMAP=1, but backend device"
 365                                " has emulate_tpws disabled\n");
 366                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 367                 }
 368                 cmd->execute_cmd = sbc_execute_write_same_unmap;
 369                 return 0;
 370         }
 371         if (!ops->execute_write_same)
 372                 return TCM_UNSUPPORTED_SCSI_OPCODE;
 373
 374         ret = sbc_check_prot(dev, cmd, flags >> 5, sectors, true);
 375         if (ret)
 376                 return ret;
 377
 378         cmd->execute_cmd = ops->execute_write_same;
 379         return 0;
 380 }
 381
 382 static sense_reason_t xdreadwrite_callback(struct se_cmd *cmd, bool success,
 383                                            int *post_ret)
 384 {
 385         unsigned char *buf, *addr;
 386         struct scatterlist *sg;
 387         unsigned int offset;
 388         sense_reason_t ret = TCM_NO_SENSE;
 389         int i, count;
 390         /*
 391          * From sbc3r22.pdf section 5.48 XDWRITEREAD (10) command
 392          *
 393          * 1) read the specified logical block(s);
 394          * 2) transfer logical blocks from the data-out buffer;
 395          * 3) XOR the logical blocks transferred from the data-out buffer with
 396          *    the logical blocks read, storing the resulting XOR data in a buffer;
 397          * 4) if the DISABLE WRITE bit is set to zero, then write the logical
 398          *    blocks transferred from the data-out buffer; and
 399          * 5) transfer the resulting XOR data to the data-in buffer.
 400          */
 401         buf = kmalloc(cmd->data_length, GFP_KERNEL);
 402         if (!buf) {
 403                 pr_err("Unable to allocate xor_callback buf\n");
 404                 return TCM_OUT_OF_RESOURCES;
 405         }
 406         /*
 407          * Copy the scatterlist WRITE buffer located at cmd->t_data_sg
 408          * into the locally allocated *buf
 409          */
 410         sg_copy_to_buffer(cmd->t_data_sg,
 411                           cmd->t_data_nents,
 412                           buf,
 413                           cmd->data_length);
 414
 415         /*
 416          * Now perform the XOR against the BIDI read memory located at
 417          * cmd->t_mem_bidi_list
 418          */
 419
 420         offset = 0;
 421         for_each_sg(cmd->t_bidi_data_sg, sg, cmd->t_bidi_data_nents, count) {
 422                 addr = kmap_atomic(sg_page(sg));
 423                 if (!addr) {
 424                         ret = TCM_OUT_OF_RESOURCES;
 425                         goto out;
 426                 }
 427
 428                 for (i = 0; i < sg->length; i++)
 429                         *(addr + sg->offset + i) ^= *(buf + offset + i);
 430
 431                 offset += sg->length;
 432                 kunmap_atomic(addr);
 433         }
 434
 435 out:
 436         kfree(buf);
 437         return ret;
 438 }
 439
 440 static sense_reason_t
 441 sbc_execute_rw(struct se_cmd *cmd)
 442 {
 443         struct sbc_ops *ops = cmd->protocol_data;
 444
 445         return ops->execute_rw(cmd, cmd->t_data_sg, cmd->t_data_nents,
 446                                cmd->data_direction);
 447 }
 448
 449 static sense_reason_t compare_and_write_post(struct se_cmd *cmd, bool success,
 450                                              int *post_ret)
 451 {
 452         struct se_device *dev = cmd->se_dev;
 453         sense_reason_t ret = TCM_NO_SENSE;
 454
 455         /*
 456          * Only set SCF_COMPARE_AND_WRITE_POST to force a response fall-through
 457          * within target_complete_ok_work() if the command was successfully
 458          * sent to the backend driver.
 459          */
 460         spin_lock_irq(&cmd->t_state_lock);
 461         if (cmd->transport_state & CMD_T_SENT) {
 462                 cmd->se_cmd_flags |= SCF_COMPARE_AND_WRITE_POST;
 463                 *post_ret = 1;
 464
 465                 if (cmd->scsi_status == SAM_STAT_CHECK_CONDITION)
 466                         ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 467         }
 468         spin_unlock_irq(&cmd->t_state_lock);
 469
 470         /*
 471          * Unlock ->caw_sem originally obtained during sbc_compare_and_write()
 472          * before the original READ I/O submission.
 473          */
 474         up(&dev->caw_sem);
 475
 476         return ret;
 477 }
 478
 479 static sense_reason_t compare_and_write_callback(struct se_cmd *cmd, bool success,
 480                                                  int *post_ret)
 481 {
 482         struct se_device *dev = cmd->se_dev;
 483         struct scatterlist *write_sg = NULL, *sg;
 484         unsigned char *buf = NULL, *addr;
 485         struct sg_mapping_iter m;
 486         unsigned int offset = 0, len;
 487         unsigned int nlbas = cmd->t_task_nolb;
 488         unsigned int block_size = dev->dev_attrib.block_size;
 489         unsigned int compare_len = (nlbas * block_size);
 490         sense_reason_t ret = TCM_NO_SENSE;
 491         int rc, i;
 492
 493         /*
 494          * Handle early failure in transport_generic_request_failure(),
 495          * which will not have taken ->caw_sem yet..
 496          */
 497         if (!success && (!cmd->t_data_sg || !cmd->t_bidi_data_sg))
 498                 return TCM_NO_SENSE;
 499         /*
 500          * Handle special case for zero-length COMPARE_AND_WRITE
 501          */
 502         if (!cmd->data_length)
 503                 goto out;
 504         /*
 505          * Immediately exit + release dev->caw_sem if command has already
 506          * been failed with a non-zero SCSI status.
 507          */
 508         if (cmd->scsi_status) {
 509                 pr_debug("compare_and_write_callback: non zero scsi_status:"
 510                         " 0x%02x\n", cmd->scsi_status);
 511                 *post_ret = 1;
 512                 if (cmd->scsi_status == SAM_STAT_CHECK_CONDITION)
 513                         ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 514                 goto out;
 515         }
 516
 517         buf = kzalloc(cmd->data_length, GFP_KERNEL);
 518         if (!buf) {
 519                 pr_err("Unable to allocate compare_and_write buf\n");
 520                 ret = TCM_OUT_OF_RESOURCES;
 521                 goto out;
 522         }
 523
 524         write_sg = kmalloc(sizeof(struct scatterlist) * cmd->t_data_nents,
 525                            GFP_KERNEL);
 526         if (!write_sg) {
 527                 pr_err("Unable to allocate compare_and_write sg\n");
 528                 ret = TCM_OUT_OF_RESOURCES;
 529                 goto out;
 530         }
 531         sg_init_table(write_sg, cmd->t_data_nents);
 532         /*
 533          * Setup verify and write data payloads from total NumberLBAs.
 534          */
 535         rc = sg_copy_to_buffer(cmd->t_data_sg, cmd->t_data_nents, buf,
 536                                cmd->data_length);
 537         if (!rc) {
 538                 pr_err("sg_copy_to_buffer() failed for compare_and_write\n");
 539                 ret = TCM_OUT_OF_RESOURCES;
 540                 goto out;
 541         }
 542         /*
 543          * Compare against SCSI READ payload against verify payload
 544          */
 545         for_each_sg(cmd->t_bidi_data_sg, sg, cmd->t_bidi_data_nents, i) {
 546                 addr = (unsigned char *)kmap_atomic(sg_page(sg));
 547                 if (!addr) {
 548                         ret = TCM_OUT_OF_RESOURCES;
 549                         goto out;
 550                 }
 551
 552                 len = min(sg->length, compare_len);
 553
 554                 if (memcmp(addr, buf + offset, len)) {
 555                         pr_warn("Detected MISCOMPARE for addr: %p buf: %p\n",
 556                                 addr, buf + offset);
 557                         kunmap_atomic(addr);
 558                         goto miscompare;
 559                 }
 560                 kunmap_atomic(addr);
 561
 562                 offset += len;
 563                 compare_len -= len;
 564                 if (!compare_len)
 565                         break;
 566         }
 567
 568         i = 0;
 569         len = cmd->t_task_nolb * block_size;
 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_BUSY|CMD_T_SENT;
 610         spin_unlock_irq(&cmd->t_state_lock);
 611
 612         __target_execute_cmd(cmd, false);
 613
 614         kfree(buf);
 615         return ret;
 616
 617 miscompare:
 618         pr_warn("Target/%s: Send MISCOMPARE check condition and sense\n",
 619                 dev->transport->name);
 620         ret = TCM_MISCOMPARE_VERIFY;
 621 out:
 622         /*
 623          * In the MISCOMPARE or failure case, unlock ->caw_sem obtained in
 624          * sbc_compare_and_write() before the original READ I/O submission.
 625          */
 626         up(&dev->caw_sem);
 627         kfree(write_sg);
 628         kfree(buf);
 629         return ret;
 630 }
 631
 632 static sense_reason_t
 633 sbc_compare_and_write(struct se_cmd *cmd)
 634 {
 635         struct sbc_ops *ops = cmd->protocol_data;
 636         struct se_device *dev = cmd->se_dev;
 637         sense_reason_t ret;
 638         int rc;
 639         /*
 640          * Submit the READ first for COMPARE_AND_WRITE to perform the
 641          * comparision using SGLs at cmd->t_bidi_data_sg..
 642          */
 643         rc = down_interruptible(&dev->caw_sem);
 644         if (rc != 0) {
 645                 cmd->transport_complete_callback = NULL;
 646                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 647         }
 648         /*
 649          * Reset cmd->data_length to individual block_size in order to not
 650          * confuse backend drivers that depend on this value matching the
 651          * size of the I/O being submitted.
 652          */
 653         cmd->data_length = cmd->t_task_nolb * dev->dev_attrib.block_size;
 654
 655         ret = ops->execute_rw(cmd, cmd->t_bidi_data_sg, cmd->t_bidi_data_nents,
 656                               DMA_FROM_DEVICE);
 657         if (ret) {
 658                 cmd->transport_complete_callback = NULL;
 659                 up(&dev->caw_sem);
 660                 return ret;
 661         }
 662         /*
 663          * Unlock of dev->caw_sem to occur in compare_and_write_callback()
 664          * upon MISCOMPARE, or in compare_and_write_done() upon completion
 665          * of WRITE instance user-data.
 666          */
 667         return TCM_NO_SENSE;
 668 }
 669
 670 static int
 671 sbc_set_prot_op_checks(u8 protect, bool fabric_prot, enum target_prot_type prot_type,
 672                        bool is_write, struct se_cmd *cmd)
 673 {
 674         if (is_write) {
 675                 cmd->prot_op = fabric_prot ? TARGET_PROT_DOUT_STRIP :
 676                                protect ? TARGET_PROT_DOUT_PASS :
 677                                TARGET_PROT_DOUT_INSERT;
 678                 switch (protect) {
 679                 case 0x0:
 680                 case 0x3:
 681                         cmd->prot_checks = 0;
 682                         break;
 683                 case 0x1:
 684                 case 0x5:
 685                         cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
 686                         if (prot_type == TARGET_DIF_TYPE1_PROT)
 687                                 cmd->prot_checks |= TARGET_DIF_CHECK_REFTAG;
 688                         break;
 689                 case 0x2:
 690                         if (prot_type == TARGET_DIF_TYPE1_PROT)
 691                                 cmd->prot_checks = TARGET_DIF_CHECK_REFTAG;
 692                         break;
 693                 case 0x4:
 694                         cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
 695                         break;
 696                 default:
 697                         pr_err("Unsupported protect field %d\n", protect);
 698                         return -EINVAL;
 699                 }
 700         } else {
 701                 cmd->prot_op = fabric_prot ? TARGET_PROT_DIN_INSERT :
 702                                protect ? TARGET_PROT_DIN_PASS :
 703                                TARGET_PROT_DIN_STRIP;
 704                 switch (protect) {
 705                 case 0x0:
 706                 case 0x1:
 707                 case 0x5:
 708                         cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
 709                         if (prot_type == TARGET_DIF_TYPE1_PROT)
 710                                 cmd->prot_checks |= TARGET_DIF_CHECK_REFTAG;
 711                         break;
 712                 case 0x2:
 713                         if (prot_type == TARGET_DIF_TYPE1_PROT)
 714                                 cmd->prot_checks = TARGET_DIF_CHECK_REFTAG;
 715                         break;
 716                 case 0x3:
 717                         cmd->prot_checks = 0;
 718                         break;
 719                 case 0x4:
 720                         cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
 721                         break;
 722                 default:
 723                         pr_err("Unsupported protect field %d\n", protect);
 724                         return -EINVAL;
 725                 }
 726         }
 727
 728         return 0;
 729 }
 730
 731 static sense_reason_t
 732 sbc_check_prot(struct se_device *dev, struct se_cmd *cmd, unsigned char protect,
 733                u32 sectors, bool is_write)
 734 {
 735         int sp_ops = cmd->se_sess->sup_prot_ops;
 736         int pi_prot_type = dev->dev_attrib.pi_prot_type;
 737         bool fabric_prot = false;
 738
 739         if (!cmd->t_prot_sg || !cmd->t_prot_nents) {
 740                 if (unlikely(protect &&
 741                     !dev->dev_attrib.pi_prot_type && !cmd->se_sess->sess_prot_type)) {
 742                         pr_err("CDB contains protect bit, but device + fabric does"
 743                                " not advertise PROTECT=1 feature bit\n");
 744                         return TCM_INVALID_CDB_FIELD;
 745                 }
 746                 if (cmd->prot_pto)
 747                         return TCM_NO_SENSE;
 748         }
 749
 750         switch (dev->dev_attrib.pi_prot_type) {
 751         case TARGET_DIF_TYPE3_PROT:
 752                 cmd->reftag_seed = 0xffffffff;
 753                 break;
 754         case TARGET_DIF_TYPE2_PROT:
 755                 if (protect)
 756                         return TCM_INVALID_CDB_FIELD;
 757
 758                 cmd->reftag_seed = cmd->t_task_lba;
 759                 break;
 760         case TARGET_DIF_TYPE1_PROT:
 761                 cmd->reftag_seed = cmd->t_task_lba;
 762                 break;
 763         case TARGET_DIF_TYPE0_PROT:
 764                 /*
 765                  * See if the fabric supports T10-PI, and the session has been
 766                  * configured to allow export PROTECT=1 feature bit with backend
 767                  * devices that don't support T10-PI.
 768                  */
 769                 fabric_prot = is_write ?
 770                               !!(sp_ops & (TARGET_PROT_DOUT_PASS | TARGET_PROT_DOUT_STRIP)) :
 771                               !!(sp_ops & (TARGET_PROT_DIN_PASS | TARGET_PROT_DIN_INSERT));
 772
 773                 if (fabric_prot && cmd->se_sess->sess_prot_type) {
 774                         pi_prot_type = cmd->se_sess->sess_prot_type;
 775                         break;
 776                 }
 777                 if (!protect)
 778                         return TCM_NO_SENSE;
 779                 /* Fallthrough */
 780         default:
 781                 pr_err("Unable to determine pi_prot_type for CDB: 0x%02x "
 782                        "PROTECT: 0x%02x\n", cmd->t_task_cdb[0], protect);
 783                 return TCM_INVALID_CDB_FIELD;
 784         }
 785
 786         if (sbc_set_prot_op_checks(protect, fabric_prot, pi_prot_type, is_write, cmd))
 787                 return TCM_INVALID_CDB_FIELD;
 788
 789         cmd->prot_type = pi_prot_type;
 790         cmd->prot_length = dev->prot_length * sectors;
 791
 792         /**
 793          * In case protection information exists over the wire
 794          * we modify command data length to describe pure data.
 795          * The actual transfer length is data length + protection
 796          * length
 797          **/
 798         if (protect)
 799                 cmd->data_length = sectors * dev->dev_attrib.block_size;
 800
 801         pr_debug("%s: prot_type=%d, data_length=%d, prot_length=%d "
 802                  "prot_op=%d prot_checks=%d\n",
 803                  __func__, cmd->prot_type, cmd->data_length, cmd->prot_length,
 804                  cmd->prot_op, cmd->prot_checks);
 805
 806         return TCM_NO_SENSE;
 807 }
 808
 809 static int
 810 sbc_check_dpofua(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb)
 811 {
 812         if (cdb[1] & 0x10) {
 813                 /* see explanation in spc_emulate_modesense */
 814                 if (!target_check_fua(dev)) {
 815                         pr_err("Got CDB: 0x%02x with DPO bit set, but device"
 816                                " does not advertise support for DPO\n", cdb[0]);
 817                         return -EINVAL;
 818                 }
 819         }
 820         if (cdb[1] & 0x8) {
 821                 if (!target_check_fua(dev)) {
 822                         pr_err("Got CDB: 0x%02x with FUA bit set, but device"
 823                                " does not advertise support for FUA write\n",
 824                                cdb[0]);
 825                         return -EINVAL;
 826                 }
 827                 cmd->se_cmd_flags |= SCF_FUA;
 828         }
 829         return 0;
 830 }
 831
 832 sense_reason_t
 833 sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
 834 {
 835         struct se_device *dev = cmd->se_dev;
 836         unsigned char *cdb = cmd->t_task_cdb;
 837         unsigned int size;
 838         u32 sectors = 0;
 839         sense_reason_t ret;
 840
 841         cmd->protocol_data = ops;
 842
 843         switch (cdb[0]) {
 844         case READ_6:
 845                 sectors = transport_get_sectors_6(cdb);
 846                 cmd->t_task_lba = transport_lba_21(cdb);
 847                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 848                 cmd->execute_cmd = sbc_execute_rw;
 849                 break;
 850         case READ_10:
 851                 sectors = transport_get_sectors_10(cdb);
 852                 cmd->t_task_lba = transport_lba_32(cdb);
 853
 854                 if (sbc_check_dpofua(dev, cmd, cdb))
 855                         return TCM_INVALID_CDB_FIELD;
 856
 857                 ret = sbc_check_prot(dev, cmd, cdb[1] >> 5, sectors, false);
 858                 if (ret)
 859                         return ret;
 860
 861                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 862                 cmd->execute_cmd = sbc_execute_rw;
 863                 break;
 864         case READ_12:
 865                 sectors = transport_get_sectors_12(cdb);
 866                 cmd->t_task_lba = transport_lba_32(cdb);
 867
 868                 if (sbc_check_dpofua(dev, cmd, cdb))
 869                         return TCM_INVALID_CDB_FIELD;
 870
 871                 ret = sbc_check_prot(dev, cmd, cdb[1] >> 5, sectors, false);
 872                 if (ret)
 873                         return ret;
 874
 875                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 876                 cmd->execute_cmd = sbc_execute_rw;
 877                 break;
 878         case READ_16:
 879                 sectors = transport_get_sectors_16(cdb);
 880                 cmd->t_task_lba = transport_lba_64(cdb);
 881
 882                 if (sbc_check_dpofua(dev, cmd, cdb))
 883                         return TCM_INVALID_CDB_FIELD;
 884
 885                 ret = sbc_check_prot(dev, cmd, cdb[1] >> 5, sectors, false);
 886                 if (ret)
 887                         return ret;
 888
 889                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 890                 cmd->execute_cmd = sbc_execute_rw;
 891                 break;
 892         case WRITE_6:
 893                 sectors = transport_get_sectors_6(cdb);
 894                 cmd->t_task_lba = transport_lba_21(cdb);
 895                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 896                 cmd->execute_cmd = sbc_execute_rw;
 897                 break;
 898         case WRITE_10:
 899         case WRITE_VERIFY:
 900                 sectors = transport_get_sectors_10(cdb);
 901                 cmd->t_task_lba = transport_lba_32(cdb);
 902
 903                 if (sbc_check_dpofua(dev, cmd, cdb))
 904                         return TCM_INVALID_CDB_FIELD;
 905
 906                 ret = sbc_check_prot(dev, cmd, cdb[1] >> 5, sectors, true);
 907                 if (ret)
 908                         return ret;
 909
 910                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 911                 cmd->execute_cmd = sbc_execute_rw;
 912                 break;
 913         case WRITE_12:
 914                 sectors = transport_get_sectors_12(cdb);
 915                 cmd->t_task_lba = transport_lba_32(cdb);
 916
 917                 if (sbc_check_dpofua(dev, cmd, cdb))
 918                         return TCM_INVALID_CDB_FIELD;
 919
 920                 ret = sbc_check_prot(dev, cmd, cdb[1] >> 5, sectors, true);
 921                 if (ret)
 922                         return ret;
 923
 924                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 925                 cmd->execute_cmd = sbc_execute_rw;
 926                 break;
 927         case WRITE_16:
 928                 sectors = transport_get_sectors_16(cdb);
 929                 cmd->t_task_lba = transport_lba_64(cdb);
 930
 931                 if (sbc_check_dpofua(dev, cmd, cdb))
 932                         return TCM_INVALID_CDB_FIELD;
 933
 934                 ret = sbc_check_prot(dev, cmd, cdb[1] >> 5, sectors, true);
 935                 if (ret)
 936                         return ret;
 937
 938                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 939                 cmd->execute_cmd = sbc_execute_rw;
 940                 break;
 941         case XDWRITEREAD_10:
 942                 if (cmd->data_direction != DMA_TO_DEVICE ||
 943                     !(cmd->se_cmd_flags & SCF_BIDI))
 944                         return TCM_INVALID_CDB_FIELD;
 945                 sectors = transport_get_sectors_10(cdb);
 946
 947                 if (sbc_check_dpofua(dev, cmd, cdb))
 948                         return TCM_INVALID_CDB_FIELD;
 949
 950                 cmd->t_task_lba = transport_lba_32(cdb);
 951                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 952
 953                 /*
 954                  * Setup BIDI XOR callback to be run after I/O completion.
 955                  */
 956                 cmd->execute_cmd = sbc_execute_rw;
 957                 cmd->transport_complete_callback = &xdreadwrite_callback;
 958                 break;
 959         case VARIABLE_LENGTH_CMD:
 960         {
 961                 u16 service_action = get_unaligned_be16(&cdb[8]);
 962                 switch (service_action) {
 963                 case XDWRITEREAD_32:
 964                         sectors = transport_get_sectors_32(cdb);
 965
 966                         if (sbc_check_dpofua(dev, cmd, cdb))
 967                                 return TCM_INVALID_CDB_FIELD;
 968                         /*
 969                          * Use WRITE_32 and READ_32 opcodes for the emulated
 970                          * XDWRITE_READ_32 logic.
 971                          */
 972                         cmd->t_task_lba = transport_lba_64_ext(cdb);
 973                         cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 974
 975                         /*
 976                          * Setup BIDI XOR callback to be run during after I/O
 977                          * completion.
 978                          */
 979                         cmd->execute_cmd = sbc_execute_rw;
 980                         cmd->transport_complete_callback = &xdreadwrite_callback;
 981                         break;
 982                 case WRITE_SAME_32:
 983                         sectors = transport_get_sectors_32(cdb);
 984                         if (!sectors) {
 985                                 pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not"
 986                                        " supported\n");
 987                                 return TCM_INVALID_CDB_FIELD;
 988                         }
 989
 990                         size = sbc_get_size(cmd, 1);
 991                         cmd->t_task_lba = get_unaligned_be64(&cdb[12]);
 992
 993                         ret = sbc_setup_write_same(cmd, cdb[10], ops);
 994                         if (ret)
 995                                 return ret;
 996                         break;
 997                 default:
 998                         pr_err("VARIABLE_LENGTH_CMD service action"
 999                                 " 0x%04x not supported\n", service_action);
1000                         return TCM_UNSUPPORTED_SCSI_OPCODE;
1001                 }
1002                 break;
1003         }
1004         case COMPARE_AND_WRITE:
1005                 sectors = cdb[13];
1006                 /*
1007                  * Currently enforce COMPARE_AND_WRITE for a single sector
1008                  */
1009                 if (sectors > 1) {
1010                         pr_err("COMPARE_AND_WRITE contains NoLB: %u greater"
1011                                " than 1\n", sectors);
1012                         return TCM_INVALID_CDB_FIELD;
1013                 }
1014                 if (sbc_check_dpofua(dev, cmd, cdb))
1015                         return TCM_INVALID_CDB_FIELD;
1016
1017                 /*
1018                  * Double size because we have two buffers, note that
1019                  * zero is not an error..
1020                  */
1021                 size = 2 * sbc_get_size(cmd, sectors);
1022                 cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
1023                 cmd->t_task_nolb = sectors;
1024                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB | SCF_COMPARE_AND_WRITE;
1025                 cmd->execute_cmd = sbc_compare_and_write;
1026                 cmd->transport_complete_callback = compare_and_write_callback;
1027                 break;
1028         case READ_CAPACITY:
1029                 size = READ_CAP_LEN;
1030                 cmd->execute_cmd = sbc_emulate_readcapacity;
1031                 break;
1032         case SERVICE_ACTION_IN_16:
1033                 switch (cmd->t_task_cdb[1] & 0x1f) {
1034                 case SAI_READ_CAPACITY_16:
1035                         cmd->execute_cmd = sbc_emulate_readcapacity_16;
1036                         break;
1037                 case SAI_REPORT_REFERRALS:
1038                         cmd->execute_cmd = target_emulate_report_referrals;
1039                         break;
1040                 default:
1041                         pr_err("Unsupported SA: 0x%02x\n",
1042                                 cmd->t_task_cdb[1] & 0x1f);
1043                         return TCM_INVALID_CDB_FIELD;
1044                 }
1045                 size = (cdb[10] << 24) | (cdb[11] << 16) |
1046                        (cdb[12] << 8) | cdb[13];
1047                 break;
1048         case SYNCHRONIZE_CACHE:
1049         case SYNCHRONIZE_CACHE_16:
1050                 if (cdb[0] == SYNCHRONIZE_CACHE) {
1051                         sectors = transport_get_sectors_10(cdb);
1052                         cmd->t_task_lba = transport_lba_32(cdb);
1053                 } else {
1054                         sectors = transport_get_sectors_16(cdb);
1055                         cmd->t_task_lba = transport_lba_64(cdb);
1056                 }
1057                 if (ops->execute_sync_cache) {
1058                         cmd->execute_cmd = ops->execute_sync_cache;
1059                         goto check_lba;
1060                 }
1061                 size = 0;
1062                 cmd->execute_cmd = sbc_emulate_noop;
1063                 break;
1064         case UNMAP:
1065                 if (!ops->execute_unmap)
1066                         return TCM_UNSUPPORTED_SCSI_OPCODE;
1067
1068                 if (!dev->dev_attrib.emulate_tpu) {
1069                         pr_err("Got UNMAP, but backend device has"
1070                                " emulate_tpu disabled\n");
1071                         return TCM_UNSUPPORTED_SCSI_OPCODE;
1072                 }
1073                 size = get_unaligned_be16(&cdb[7]);
1074                 cmd->execute_cmd = sbc_execute_unmap;
1075                 break;
1076         case WRITE_SAME_16:
1077                 sectors = transport_get_sectors_16(cdb);
1078                 if (!sectors) {
1079                         pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
1080                         return TCM_INVALID_CDB_FIELD;
1081                 }
1082
1083                 size = sbc_get_size(cmd, 1);
1084                 cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
1085
1086                 ret = sbc_setup_write_same(cmd, cdb[1], ops);
1087                 if (ret)
1088                         return ret;
1089                 break;
1090         case WRITE_SAME:
1091                 sectors = transport_get_sectors_10(cdb);
1092                 if (!sectors) {
1093                         pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
1094                         return TCM_INVALID_CDB_FIELD;
1095                 }
1096
1097                 size = sbc_get_size(cmd, 1);
1098                 cmd->t_task_lba = get_unaligned_be32(&cdb[2]);
1099
1100                 /*
1101                  * Follow sbcr26 with WRITE_SAME (10) and check for the existence
1102                  * of byte 1 bit 3 UNMAP instead of original reserved field
1103                  */
1104                 ret = sbc_setup_write_same(cmd, cdb[1], ops);
1105                 if (ret)
1106                         return ret;
1107                 break;
1108         case VERIFY:
1109         case VERIFY_16:
1110                 size = 0;
1111                 if (cdb[0] == VERIFY) {
1112                         sectors = transport_get_sectors_10(cdb);
1113                         cmd->t_task_lba = transport_lba_32(cdb);
1114                 } else {
1115                         sectors = transport_get_sectors_16(cdb);
1116                         cmd->t_task_lba = transport_lba_64(cdb);
1117                 }
1118                 cmd->execute_cmd = sbc_emulate_noop;
1119                 goto check_lba;
1120         case REZERO_UNIT:
1121         case SEEK_6:
1122         case SEEK_10:
1123                 /*
1124                  * There are still clients out there which use these old SCSI-2
1125                  * commands. This mainly happens when running VMs with legacy
1126                  * guest systems, connected via SCSI command pass-through to
1127                  * iSCSI targets. Make them happy and return status GOOD.
1128                  */
1129                 size = 0;
1130                 cmd->execute_cmd = sbc_emulate_noop;
1131                 break;
1132         case START_STOP:
1133                 size = 0;
1134                 cmd->execute_cmd = sbc_emulate_startstop;
1135                 break;
1136         default:
1137                 ret = spc_parse_cdb(cmd, &size);
1138                 if (ret)
1139                         return ret;
1140         }
1141
1142         /* reject any command that we don't have a handler for */
1143         if (!cmd->execute_cmd)
1144                 return TCM_UNSUPPORTED_SCSI_OPCODE;
1145
1146         if (cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
1147                 unsigned long long end_lba;
1148 check_lba:
1149                 end_lba = dev->transport->get_blocks(dev) + 1;
1150                 if (((cmd->t_task_lba + sectors) < cmd->t_task_lba) ||
1151                     ((cmd->t_task_lba + sectors) > end_lba)) {
1152                         pr_err("cmd exceeds last lba %llu "
1153                                 "(lba %llu, sectors %u)\n",
1154                                 end_lba, cmd->t_task_lba, sectors);
1155                         return TCM_ADDRESS_OUT_OF_RANGE;
1156                 }
1157
1158                 if (!(cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE))
1159                         size = sbc_get_size(cmd, sectors);
1160         }
1161
1162         return target_cmd_size_check(cmd, size);
1163 }
1164 EXPORT_SYMBOL(sbc_parse_cdb);
1165
1166 u32 sbc_get_device_type(struct se_device *dev)
1167 {
1168         return TYPE_DISK;
1169 }
1170 EXPORT_SYMBOL(sbc_get_device_type);
1171
1172 static sense_reason_t
1173 sbc_execute_unmap(struct se_cmd *cmd)
1174 {
1175         struct sbc_ops *ops = cmd->protocol_data;
1176         struct se_device *dev = cmd->se_dev;
1177         unsigned char *buf, *ptr = NULL;
1178         sector_t lba;
1179         int size;
1180         u32 range;
1181         sense_reason_t ret = 0;
1182         int dl, bd_dl;
1183
1184         /* We never set ANC_SUP */
1185         if (cmd->t_task_cdb[1])
1186                 return TCM_INVALID_CDB_FIELD;
1187
1188         if (cmd->data_length == 0) {
1189                 target_complete_cmd(cmd, SAM_STAT_GOOD);
1190                 return 0;
1191         }
1192
1193         if (cmd->data_length < 8) {
1194                 pr_warn("UNMAP parameter list length %u too small\n",
1195                         cmd->data_length);
1196                 return TCM_PARAMETER_LIST_LENGTH_ERROR;
1197         }
1198
1199         buf = transport_kmap_data_sg(cmd);
1200         if (!buf)
1201                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1202
1203         dl = get_unaligned_be16(&buf[0]);
1204         bd_dl = get_unaligned_be16(&buf[2]);
1205
1206         size = cmd->data_length - 8;
1207         if (bd_dl > size)
1208                 pr_warn("UNMAP parameter list length %u too small, ignoring bd_dl %u\n",
1209                         cmd->data_length, bd_dl);
1210         else
1211                 size = bd_dl;
1212
1213         if (size / 16 > dev->dev_attrib.max_unmap_block_desc_count) {
1214                 ret = TCM_INVALID_PARAMETER_LIST;
1215                 goto err;
1216         }
1217
1218         /* First UNMAP block descriptor starts at 8 byte offset */
1219         ptr = &buf[8];
1220         pr_debug("UNMAP: Sub: %s Using dl: %u bd_dl: %u size: %u"
1221                 " ptr: %p\n", dev->transport->name, dl, bd_dl, size, ptr);
1222
1223         while (size >= 16) {
1224                 lba = get_unaligned_be64(&ptr[0]);
1225                 range = get_unaligned_be32(&ptr[8]);
1226                 pr_debug("UNMAP: Using lba: %llu and range: %u\n",
1227                                  (unsigned long long)lba, range);
1228
1229                 if (range > dev->dev_attrib.max_unmap_lba_count) {
1230                         ret = TCM_INVALID_PARAMETER_LIST;
1231                         goto err;
1232                 }
1233
1234                 if (lba + range > dev->transport->get_blocks(dev) + 1) {
1235                         ret = TCM_ADDRESS_OUT_OF_RANGE;
1236                         goto err;
1237                 }
1238
1239                 ret = ops->execute_unmap(cmd, lba, range);
1240                 if (ret)
1241                         goto err;
1242
1243                 ptr += 16;
1244                 size -= 16;
1245         }
1246
1247 err:
1248         transport_kunmap_data_sg(cmd);
1249         if (!ret)
1250                 target_complete_cmd(cmd, GOOD);
1251         return ret;
1252 }
1253
1254 void
1255 sbc_dif_generate(struct se_cmd *cmd)
1256 {
1257         struct se_device *dev = cmd->se_dev;
1258         struct t10_pi_tuple *sdt;
1259         struct scatterlist *dsg = cmd->t_data_sg, *psg;
1260         sector_t sector = cmd->t_task_lba;
1261         void *daddr, *paddr;
1262         int i, j, offset = 0;
1263         unsigned int block_size = dev->dev_attrib.block_size;
1264
1265         for_each_sg(cmd->t_prot_sg, psg, cmd->t_prot_nents, i) {
1266                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1267                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1268
1269                 for (j = 0; j < psg->length;
1270                                 j += sizeof(*sdt)) {
1271                         __u16 crc;
1272                         unsigned int avail;
1273
1274                         if (offset >= dsg->length) {
1275                                 offset -= dsg->length;
1276                                 kunmap_atomic(daddr - dsg->offset);
1277                                 dsg = sg_next(dsg);
1278                                 if (!dsg) {
1279                                         kunmap_atomic(paddr - psg->offset);
1280                                         return;
1281                                 }
1282                                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1283                         }
1284
1285                         sdt = paddr + j;
1286                         avail = min(block_size, dsg->length - offset);
1287                         crc = crc_t10dif(daddr + offset, avail);
1288                         if (avail < block_size) {
1289                                 kunmap_atomic(daddr - dsg->offset);
1290                                 dsg = sg_next(dsg);
1291                                 if (!dsg) {
1292                                         kunmap_atomic(paddr - psg->offset);
1293                                         return;
1294                                 }
1295                                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1296                                 offset = block_size - avail;
1297                                 crc = crc_t10dif_update(crc, daddr, offset);
1298                         } else {
1299                                 offset += block_size;
1300                         }
1301
1302                         sdt->guard_tag = cpu_to_be16(crc);
1303                         if (cmd->prot_type == TARGET_DIF_TYPE1_PROT)
1304                                 sdt->ref_tag = cpu_to_be32(sector & 0xffffffff);
1305                         sdt->app_tag = 0;
1306
1307                         pr_debug("DIF %s INSERT sector: %llu guard_tag: 0x%04x"
1308                                  " app_tag: 0x%04x ref_tag: %u\n",
1309                                  (cmd->data_direction == DMA_TO_DEVICE) ?
1310                                  "WRITE" : "READ", (unsigned long long)sector,
1311                                  sdt->guard_tag, sdt->app_tag,
1312                                  be32_to_cpu(sdt->ref_tag));
1313
1314                         sector++;
1315                 }
1316
1317                 kunmap_atomic(daddr - dsg->offset);
1318                 kunmap_atomic(paddr - psg->offset);
1319         }
1320 }
1321
1322 static sense_reason_t
1323 sbc_dif_v1_verify(struct se_cmd *cmd, struct t10_pi_tuple *sdt,
1324                   __u16 crc, sector_t sector, unsigned int ei_lba)
1325 {
1326         __be16 csum;
1327
1328         if (!(cmd->prot_checks & TARGET_DIF_CHECK_GUARD))
1329                 goto check_ref;
1330
1331         csum = cpu_to_be16(crc);
1332
1333         if (sdt->guard_tag != csum) {
1334                 pr_err("DIFv1 checksum failed on sector %llu guard tag 0x%04x"
1335                         " csum 0x%04x\n", (unsigned long long)sector,
1336                         be16_to_cpu(sdt->guard_tag), be16_to_cpu(csum));
1337                 return TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED;
1338         }
1339
1340 check_ref:
1341         if (!(cmd->prot_checks & TARGET_DIF_CHECK_REFTAG))
1342                 return 0;
1343
1344         if (cmd->prot_type == TARGET_DIF_TYPE1_PROT &&
1345             be32_to_cpu(sdt->ref_tag) != (sector & 0xffffffff)) {
1346                 pr_err("DIFv1 Type 1 reference failed on sector: %llu tag: 0x%08x"
1347                        " sector MSB: 0x%08x\n", (unsigned long long)sector,
1348                        be32_to_cpu(sdt->ref_tag), (u32)(sector & 0xffffffff));
1349                 return TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;
1350         }
1351
1352         if (cmd->prot_type == TARGET_DIF_TYPE2_PROT &&
1353             be32_to_cpu(sdt->ref_tag) != ei_lba) {
1354                 pr_err("DIFv1 Type 2 reference failed on sector: %llu tag: 0x%08x"
1355                        " ei_lba: 0x%08x\n", (unsigned long long)sector,
1356                         be32_to_cpu(sdt->ref_tag), ei_lba);
1357                 return TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;
1358         }
1359
1360         return 0;
1361 }
1362
1363 void sbc_dif_copy_prot(struct se_cmd *cmd, unsigned int sectors, bool read,
1364                        struct scatterlist *sg, int sg_off)
1365 {
1366         struct se_device *dev = cmd->se_dev;
1367         struct scatterlist *psg;
1368         void *paddr, *addr;
1369         unsigned int i, len, left;
1370         unsigned int offset = sg_off;
1371
1372         if (!sg)
1373                 return;
1374
1375         left = sectors * dev->prot_length;
1376
1377         for_each_sg(cmd->t_prot_sg, psg, cmd->t_prot_nents, i) {
1378                 unsigned int psg_len, copied = 0;
1379
1380                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1381                 psg_len = min(left, psg->length);
1382                 while (psg_len) {
1383                         len = min(psg_len, sg->length - offset);
1384                         addr = kmap_atomic(sg_page(sg)) + sg->offset + offset;
1385
1386                         if (read)
1387                                 memcpy(paddr + copied, addr, len);
1388                         else
1389                                 memcpy(addr, paddr + copied, len);
1390
1391                         left -= len;
1392                         offset += len;
1393                         copied += len;
1394                         psg_len -= len;
1395
1396                         kunmap_atomic(addr - sg->offset - offset);
1397
1398                         if (offset >= sg->length) {
1399                                 sg = sg_next(sg);
1400                                 offset = 0;
1401                         }
1402                 }
1403                 kunmap_atomic(paddr - psg->offset);
1404         }
1405 }
1406 EXPORT_SYMBOL(sbc_dif_copy_prot);
1407
1408 sense_reason_t
1409 sbc_dif_verify(struct se_cmd *cmd, sector_t start, unsigned int sectors,
1410                unsigned int ei_lba, struct scatterlist *psg, int psg_off)
1411 {
1412         struct se_device *dev = cmd->se_dev;
1413         struct t10_pi_tuple *sdt;
1414         struct scatterlist *dsg = cmd->t_data_sg;
1415         sector_t sector = start;
1416         void *daddr, *paddr;
1417         int i;
1418         sense_reason_t rc;
1419         int dsg_off = 0;
1420         unsigned int block_size = dev->dev_attrib.block_size;
1421
1422         for (; psg && sector < start + sectors; psg = sg_next(psg)) {
1423                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1424                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1425
1426                 for (i = psg_off; i < psg->length &&
1427                                 sector < start + sectors;
1428                                 i += sizeof(*sdt)) {
1429                         __u16 crc;
1430                         unsigned int avail;
1431
1432                         if (dsg_off >= dsg->length) {
1433                                 dsg_off -= dsg->length;
1434                                 kunmap_atomic(daddr - dsg->offset);
1435                                 dsg = sg_next(dsg);
1436                                 if (!dsg) {
1437                                         kunmap_atomic(paddr - psg->offset);
1438                                         return 0;
1439                                 }
1440                                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1441                         }
1442
1443                         sdt = paddr + i;
1444
1445                         pr_debug("DIF READ sector: %llu guard_tag: 0x%04x"
1446                                  " app_tag: 0x%04x ref_tag: %u\n",
1447                                  (unsigned long long)sector, sdt->guard_tag,
1448                                  sdt->app_tag, be32_to_cpu(sdt->ref_tag));
1449
1450                         if (sdt->app_tag == cpu_to_be16(0xffff)) {
1451                                 dsg_off += block_size;
1452                                 goto next;
1453                         }
1454
1455                         avail = min(block_size, dsg->length - dsg_off);
1456                         crc = crc_t10dif(daddr + dsg_off, avail);
1457                         if (avail < block_size) {
1458                                 kunmap_atomic(daddr - dsg->offset);
1459                                 dsg = sg_next(dsg);
1460                                 if (!dsg) {
1461                                         kunmap_atomic(paddr - psg->offset);
1462                                         return 0;
1463                                 }
1464                                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1465                                 dsg_off = block_size - avail;
1466                                 crc = crc_t10dif_update(crc, daddr, dsg_off);
1467                         } else {
1468                                 dsg_off += block_size;
1469                         }
1470
1471                         rc = sbc_dif_v1_verify(cmd, sdt, crc, sector, ei_lba);
1472                         if (rc) {
1473                                 kunmap_atomic(daddr - dsg->offset);
1474                                 kunmap_atomic(paddr - psg->offset);
1475                                 cmd->bad_sector = sector;
1476                                 return rc;
1477                         }
1478 next:
1479                         sector++;
1480                         ei_lba++;
1481                 }
1482
1483                 psg_off = 0;
1484                 kunmap_atomic(daddr - dsg->offset);
1485                 kunmap_atomic(paddr - psg->offset);
1486         }
1487
1488         return 0;
1489 }
1490 EXPORT_SYMBOL(sbc_dif_verify);