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         buf[0] = (blocks >> 24) & 0xff;
  75         buf[1] = (blocks >> 16) & 0xff;
  76         buf[2] = (blocks >> 8) & 0xff;
  77         buf[3] = blocks & 0xff;
  78         buf[4] = (dev->dev_attrib.block_size >> 24) & 0xff;
  79         buf[5] = (dev->dev_attrib.block_size >> 16) & 0xff;
  80         buf[6] = (dev->dev_attrib.block_size >> 8) & 0xff;
  81         buf[7] = dev->dev_attrib.block_size & 0xff;
  82
  83         rbuf = transport_kmap_data_sg(cmd);
  84         if (rbuf) {
  85                 memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length));
  86                 transport_kunmap_data_sg(cmd);
  87         }
  88
  89         target_complete_cmd_with_length(cmd, GOOD, 8);
  90         return 0;
  91 }
  92
  93 static sense_reason_t
  94 sbc_emulate_readcapacity_16(struct se_cmd *cmd)
  95 {
  96         struct se_device *dev = cmd->se_dev;
  97         struct se_session *sess = cmd->se_sess;
  98         int pi_prot_type = dev->dev_attrib.pi_prot_type;
  99
 100         unsigned char *rbuf;
 101         unsigned char buf[32];
 102         unsigned long long blocks = dev->transport->get_blocks(dev);
 103
 104         memset(buf, 0, sizeof(buf));
 105         buf[0] = (blocks >> 56) & 0xff;
 106         buf[1] = (blocks >> 48) & 0xff;
 107         buf[2] = (blocks >> 40) & 0xff;
 108         buf[3] = (blocks >> 32) & 0xff;
 109         buf[4] = (blocks >> 24) & 0xff;
 110         buf[5] = (blocks >> 16) & 0xff;
 111         buf[6] = (blocks >> 8) & 0xff;
 112         buf[7] = blocks & 0xff;
 113         buf[8] = (dev->dev_attrib.block_size >> 24) & 0xff;
 114         buf[9] = (dev->dev_attrib.block_size >> 16) & 0xff;
 115         buf[10] = (dev->dev_attrib.block_size >> 8) & 0xff;
 116         buf[11] = dev->dev_attrib.block_size & 0xff;
 117         /*
 118          * Set P_TYPE and PROT_EN bits for DIF support
 119          */
 120         if (sess->sup_prot_ops & (TARGET_PROT_DIN_PASS | TARGET_PROT_DOUT_PASS)) {
 121                 /*
 122                  * Only override a device's pi_prot_type if no T10-PI is
 123                  * available, and sess_prot_type has been explicitly enabled.
 124                  */
 125                 if (!pi_prot_type)
 126                         pi_prot_type = sess->sess_prot_type;
 127
 128                 if (pi_prot_type)
 129                         buf[12] = (pi_prot_type - 1) << 1 | 0x1;
 130         }
 131
 132         if (dev->transport->get_lbppbe)
 133                 buf[13] = dev->transport->get_lbppbe(dev) & 0x0f;
 134
 135         if (dev->transport->get_alignment_offset_lbas) {
 136                 u16 lalba = dev->transport->get_alignment_offset_lbas(dev);
 137                 buf[14] = (lalba >> 8) & 0x3f;
 138                 buf[15] = lalba & 0xff;
 139         }
 140
 141         /*
 142          * Set Thin Provisioning Enable bit following sbc3r22 in section
 143          * READ CAPACITY (16) byte 14 if emulate_tpu or emulate_tpws is enabled.
 144          */
 145         if (dev->dev_attrib.emulate_tpu || dev->dev_attrib.emulate_tpws) {
 146                 buf[14] |= 0x80;
 147
 148                 /*
 149                  * LBPRZ signifies that zeroes will be read back from an LBA after
 150                  * an UNMAP or WRITE SAME w/ unmap bit (sbc3r36 5.16.2)
 151                  */
 152                 if (dev->dev_attrib.unmap_zeroes_data)
 153                         buf[14] |= 0x40;
 154         }
 155
 156         rbuf = transport_kmap_data_sg(cmd);
 157         if (rbuf) {
 158                 memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length));
 159                 transport_kunmap_data_sg(cmd);
 160         }
 161
 162         target_complete_cmd_with_length(cmd, GOOD, 32);
 163         return 0;
 164 }
 165
 166 static sense_reason_t
 167 sbc_emulate_startstop(struct se_cmd *cmd)
 168 {
 169         unsigned char *cdb = cmd->t_task_cdb;
 170
 171         /*
 172          * See sbc3r36 section 5.25
 173          * Immediate bit should be set since there is nothing to complete
 174          * POWER CONDITION MODIFIER 0h
 175          */
 176         if (!(cdb[1] & 1) || cdb[2] || cdb[3])
 177                 return TCM_INVALID_CDB_FIELD;
 178
 179         /*
 180          * See sbc3r36 section 5.25
 181          * POWER CONDITION 0h START_VALID - process START and LOEJ
 182          */
 183         if (cdb[4] >> 4 & 0xf)
 184                 return TCM_INVALID_CDB_FIELD;
 185
 186         /*
 187          * See sbc3r36 section 5.25
 188          * LOEJ 0h - nothing to load or unload
 189          * START 1h - we are ready
 190          */
 191         if (!(cdb[4] & 1) || (cdb[4] & 2) || (cdb[4] & 4))
 192                 return TCM_INVALID_CDB_FIELD;
 193
 194         target_complete_cmd(cmd, SAM_STAT_GOOD);
 195         return 0;
 196 }
 197
 198 sector_t sbc_get_write_same_sectors(struct se_cmd *cmd)
 199 {
 200         u32 num_blocks;
 201
 202         if (cmd->t_task_cdb[0] == WRITE_SAME)
 203                 num_blocks = get_unaligned_be16(&cmd->t_task_cdb[7]);
 204         else if (cmd->t_task_cdb[0] == WRITE_SAME_16)
 205                 num_blocks = get_unaligned_be32(&cmd->t_task_cdb[10]);
 206         else /* WRITE_SAME_32 via VARIABLE_LENGTH_CMD */
 207                 num_blocks = get_unaligned_be32(&cmd->t_task_cdb[28]);
 208
 209         /*
 210          * Use the explicit range when non zero is supplied, otherwise calculate
 211          * the remaining range based on ->get_blocks() - starting LBA.
 212          */
 213         if (num_blocks)
 214                 return num_blocks;
 215
 216         return cmd->se_dev->transport->get_blocks(cmd->se_dev) -
 217                 cmd->t_task_lba + 1;
 218 }
 219 EXPORT_SYMBOL(sbc_get_write_same_sectors);
 220
 221 static sense_reason_t
 222 sbc_execute_write_same_unmap(struct se_cmd *cmd)
 223 {
 224         struct sbc_ops *ops = cmd->protocol_data;
 225         sector_t nolb = sbc_get_write_same_sectors(cmd);
 226         sense_reason_t ret;
 227
 228         if (nolb) {
 229                 ret = ops->execute_unmap(cmd, cmd->t_task_lba, nolb);
 230                 if (ret)
 231                         return ret;
 232         }
 233
 234         target_complete_cmd(cmd, GOOD);
 235         return 0;
 236 }
 237
 238 static sense_reason_t
 239 sbc_emulate_noop(struct se_cmd *cmd)
 240 {
 241         target_complete_cmd(cmd, GOOD);
 242         return 0;
 243 }
 244
 245 static inline u32 sbc_get_size(struct se_cmd *cmd, u32 sectors)
 246 {
 247         return cmd->se_dev->dev_attrib.block_size * sectors;
 248 }
 249
 250 static inline u32 transport_get_sectors_6(unsigned char *cdb)
 251 {
 252         /*
 253          * Use 8-bit sector value.  SBC-3 says:
 254          *
 255          *   A TRANSFER LENGTH field set to zero specifies that 256
 256          *   logical blocks shall be written.  Any other value
 257          *   specifies the number of logical blocks that shall be
 258          *   written.
 259          */
 260         return cdb[4] ? : 256;
 261 }
 262
 263 static inline u32 transport_get_sectors_10(unsigned char *cdb)
 264 {
 265         return (u32)(cdb[7] << 8) + cdb[8];
 266 }
 267
 268 static inline u32 transport_get_sectors_12(unsigned char *cdb)
 269 {
 270         return (u32)(cdb[6] << 24) + (cdb[7] << 16) + (cdb[8] << 8) + cdb[9];
 271 }
 272
 273 static inline u32 transport_get_sectors_16(unsigned char *cdb)
 274 {
 275         return (u32)(cdb[10] << 24) + (cdb[11] << 16) +
 276                     (cdb[12] << 8) + cdb[13];
 277 }
 278
 279 /*
 280  * Used for VARIABLE_LENGTH_CDB WRITE_32 and READ_32 variants
 281  */
 282 static inline u32 transport_get_sectors_32(unsigned char *cdb)
 283 {
 284         return (u32)(cdb[28] << 24) + (cdb[29] << 16) +
 285                     (cdb[30] << 8) + cdb[31];
 286
 287 }
 288
 289 static inline u32 transport_lba_21(unsigned char *cdb)
 290 {
 291         return ((cdb[1] & 0x1f) << 16) | (cdb[2] << 8) | cdb[3];
 292 }
 293
 294 static inline u32 transport_lba_32(unsigned char *cdb)
 295 {
 296         return (cdb[2] << 24) | (cdb[3] << 16) | (cdb[4] << 8) | cdb[5];
 297 }
 298
 299 static inline unsigned long long transport_lba_64(unsigned char *cdb)
 300 {
 301         unsigned int __v1, __v2;
 302
 303         __v1 = (cdb[2] << 24) | (cdb[3] << 16) | (cdb[4] << 8) | cdb[5];
 304         __v2 = (cdb[6] << 24) | (cdb[7] << 16) | (cdb[8] << 8) | cdb[9];
 305
 306         return ((unsigned long long)__v2) | (unsigned long long)__v1 << 32;
 307 }
 308
 309 /*
 310  * For VARIABLE_LENGTH_CDB w/ 32 byte extended CDBs
 311  */
 312 static inline unsigned long long transport_lba_64_ext(unsigned char *cdb)
 313 {
 314         unsigned int __v1, __v2;
 315
 316         __v1 = (cdb[12] << 24) | (cdb[13] << 16) | (cdb[14] << 8) | cdb[15];
 317         __v2 = (cdb[16] << 24) | (cdb[17] << 16) | (cdb[18] << 8) | cdb[19];
 318
 319         return ((unsigned long long)__v2) | (unsigned long long)__v1 << 32;
 320 }
 321
 322 static sense_reason_t
 323 sbc_setup_write_same(struct se_cmd *cmd, unsigned char *flags, struct sbc_ops *ops)
 324 {
 325         struct se_device *dev = cmd->se_dev;
 326         sector_t end_lba = dev->transport->get_blocks(dev) + 1;
 327         unsigned int sectors = sbc_get_write_same_sectors(cmd);
 328         sense_reason_t ret;
 329
 330         if ((flags[0] & 0x04) || (flags[0] & 0x02)) {
 331                 pr_err("WRITE_SAME PBDATA and LBDATA"
 332                         " bits not supported for Block Discard"
 333                         " Emulation\n");
 334                 return TCM_UNSUPPORTED_SCSI_OPCODE;
 335         }
 336         if (sectors > cmd->se_dev->dev_attrib.max_write_same_len) {
 337                 pr_warn("WRITE_SAME sectors: %u exceeds max_write_same_len: %u\n",
 338                         sectors, cmd->se_dev->dev_attrib.max_write_same_len);
 339                 return TCM_INVALID_CDB_FIELD;
 340         }
 341         /*
 342          * Sanity check for LBA wrap and request past end of device.
 343          */
 344         if (((cmd->t_task_lba + sectors) < cmd->t_task_lba) ||
 345             ((cmd->t_task_lba + sectors) > end_lba)) {
 346                 pr_err("WRITE_SAME exceeds last lba %llu (lba %llu, sectors %u)\n",
 347                        (unsigned long long)end_lba, cmd->t_task_lba, sectors);
 348                 return TCM_ADDRESS_OUT_OF_RANGE;
 349         }
 350
 351         /* We always have ANC_SUP == 0 so setting ANCHOR is always an error */
 352         if (flags[0] & 0x10) {
 353                 pr_warn("WRITE SAME with ANCHOR not supported\n");
 354                 return TCM_INVALID_CDB_FIELD;
 355         }
 356         /*
 357          * Special case for WRITE_SAME w/ UNMAP=1 that ends up getting
 358          * translated into block discard requests within backend code.
 359          */
 360         if (flags[0] & 0x08) {
 361                 if (!ops->execute_unmap)
 362                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 363
 364                 if (!dev->dev_attrib.emulate_tpws) {
 365                         pr_err("Got WRITE_SAME w/ UNMAP=1, but backend device"
 366                                " has emulate_tpws disabled\n");
 367                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 368                 }
 369                 cmd->execute_cmd = sbc_execute_write_same_unmap;
 370                 return 0;
 371         }
 372         if (!ops->execute_write_same)
 373                 return TCM_UNSUPPORTED_SCSI_OPCODE;
 374
 375         ret = sbc_check_prot(dev, cmd, &cmd->t_task_cdb[0], sectors, true);
 376         if (ret)
 377                 return ret;
 378
 379         cmd->execute_cmd = ops->execute_write_same;
 380         return 0;
 381 }
 382
 383 static sense_reason_t xdreadwrite_callback(struct se_cmd *cmd, bool success,
 384                                            int *post_ret)
 385 {
 386         unsigned char *buf, *addr;
 387         struct scatterlist *sg;
 388         unsigned int offset;
 389         sense_reason_t ret = TCM_NO_SENSE;
 390         int i, count;
 391         /*
 392          * From sbc3r22.pdf section 5.48 XDWRITEREAD (10) command
 393          *
 394          * 1) read the specified logical block(s);
 395          * 2) transfer logical blocks from the data-out buffer;
 396          * 3) XOR the logical blocks transferred from the data-out buffer with
 397          *    the logical blocks read, storing the resulting XOR data in a buffer;
 398          * 4) if the DISABLE WRITE bit is set to zero, then write the logical
 399          *    blocks transferred from the data-out buffer; and
 400          * 5) transfer the resulting XOR data to the data-in buffer.
 401          */
 402         buf = kmalloc(cmd->data_length, GFP_KERNEL);
 403         if (!buf) {
 404                 pr_err("Unable to allocate xor_callback buf\n");
 405                 return TCM_OUT_OF_RESOURCES;
 406         }
 407         /*
 408          * Copy the scatterlist WRITE buffer located at cmd->t_data_sg
 409          * into the locally allocated *buf
 410          */
 411         sg_copy_to_buffer(cmd->t_data_sg,
 412                           cmd->t_data_nents,
 413                           buf,
 414                           cmd->data_length);
 415
 416         /*
 417          * Now perform the XOR against the BIDI read memory located at
 418          * cmd->t_mem_bidi_list
 419          */
 420
 421         offset = 0;
 422         for_each_sg(cmd->t_bidi_data_sg, sg, cmd->t_bidi_data_nents, count) {
 423                 addr = kmap_atomic(sg_page(sg));
 424                 if (!addr) {
 425                         ret = TCM_OUT_OF_RESOURCES;
 426                         goto out;
 427                 }
 428
 429                 for (i = 0; i < sg->length; i++)
 430                         *(addr + sg->offset + i) ^= *(buf + offset + i);
 431
 432                 offset += sg->length;
 433                 kunmap_atomic(addr);
 434         }
 435
 436 out:
 437         kfree(buf);
 438         return ret;
 439 }
 440
 441 static sense_reason_t
 442 sbc_execute_rw(struct se_cmd *cmd)
 443 {
 444         struct sbc_ops *ops = cmd->protocol_data;
 445
 446         return ops->execute_rw(cmd, cmd->t_data_sg, cmd->t_data_nents,
 447                                cmd->data_direction);
 448 }
 449
 450 static sense_reason_t compare_and_write_post(struct se_cmd *cmd, bool success,
 451                                              int *post_ret)
 452 {
 453         struct se_device *dev = cmd->se_dev;
 454         sense_reason_t ret = TCM_NO_SENSE;
 455
 456         /*
 457          * Only set SCF_COMPARE_AND_WRITE_POST to force a response fall-through
 458          * within target_complete_ok_work() if the command was successfully
 459          * sent to the backend driver.
 460          */
 461         spin_lock_irq(&cmd->t_state_lock);
 462         if (cmd->transport_state & CMD_T_SENT) {
 463                 cmd->se_cmd_flags |= SCF_COMPARE_AND_WRITE_POST;
 464                 *post_ret = 1;
 465
 466                 if (cmd->scsi_status == SAM_STAT_CHECK_CONDITION)
 467                         ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 468         }
 469         spin_unlock_irq(&cmd->t_state_lock);
 470
 471         /*
 472          * Unlock ->caw_sem originally obtained during sbc_compare_and_write()
 473          * before the original READ I/O submission.
 474          */
 475         up(&dev->caw_sem);
 476
 477         return ret;
 478 }
 479
 480 static sense_reason_t compare_and_write_callback(struct se_cmd *cmd, bool success,
 481                                                  int *post_ret)
 482 {
 483         struct se_device *dev = cmd->se_dev;
 484         struct scatterlist *write_sg = NULL, *sg;
 485         unsigned char *buf = NULL, *addr;
 486         struct sg_mapping_iter m;
 487         unsigned int offset = 0, len;
 488         unsigned int nlbas = cmd->t_task_nolb;
 489         unsigned int block_size = dev->dev_attrib.block_size;
 490         unsigned int compare_len = (nlbas * block_size);
 491         sense_reason_t ret = TCM_NO_SENSE;
 492         int rc, i;
 493
 494         /*
 495          * Handle early failure in transport_generic_request_failure(),
 496          * which will not have taken ->caw_sem yet..
 497          */
 498         if (!success && (!cmd->t_data_sg || !cmd->t_bidi_data_sg))
 499                 return TCM_NO_SENSE;
 500         /*
 501          * Handle special case for zero-length COMPARE_AND_WRITE
 502          */
 503         if (!cmd->data_length)
 504                 goto out;
 505         /*
 506          * Immediately exit + release dev->caw_sem if command has already
 507          * been failed with a non-zero SCSI status.
 508          */
 509         if (cmd->scsi_status) {
 510                 pr_err("compare_and_write_callback: non zero scsi_status:"
 511                         " 0x%02x\n", cmd->scsi_status);
 512                 goto out;
 513         }
 514
 515         buf = kzalloc(cmd->data_length, GFP_KERNEL);
 516         if (!buf) {
 517                 pr_err("Unable to allocate compare_and_write buf\n");
 518                 ret = TCM_OUT_OF_RESOURCES;
 519                 goto out;
 520         }
 521
 522         write_sg = kmalloc(sizeof(struct scatterlist) * cmd->t_data_nents,
 523                            GFP_KERNEL);
 524         if (!write_sg) {
 525                 pr_err("Unable to allocate compare_and_write sg\n");
 526                 ret = TCM_OUT_OF_RESOURCES;
 527                 goto out;
 528         }
 529         sg_init_table(write_sg, cmd->t_data_nents);
 530         /*
 531          * Setup verify and write data payloads from total NumberLBAs.
 532          */
 533         rc = sg_copy_to_buffer(cmd->t_data_sg, cmd->t_data_nents, buf,
 534                                cmd->data_length);
 535         if (!rc) {
 536                 pr_err("sg_copy_to_buffer() failed for compare_and_write\n");
 537                 ret = TCM_OUT_OF_RESOURCES;
 538                 goto out;
 539         }
 540         /*
 541          * Compare against SCSI READ payload against verify payload
 542          */
 543         for_each_sg(cmd->t_bidi_data_sg, sg, cmd->t_bidi_data_nents, i) {
 544                 addr = (unsigned char *)kmap_atomic(sg_page(sg));
 545                 if (!addr) {
 546                         ret = TCM_OUT_OF_RESOURCES;
 547                         goto out;
 548                 }
 549
 550                 len = min(sg->length, compare_len);
 551
 552                 if (memcmp(addr, buf + offset, len)) {
 553                         pr_warn("Detected MISCOMPARE for addr: %p buf: %p\n",
 554                                 addr, buf + offset);
 555                         kunmap_atomic(addr);
 556                         goto miscompare;
 557                 }
 558                 kunmap_atomic(addr);
 559
 560                 offset += len;
 561                 compare_len -= len;
 562                 if (!compare_len)
 563                         break;
 564         }
 565
 566         i = 0;
 567         len = cmd->t_task_nolb * block_size;
 568         sg_miter_start(&m, cmd->t_data_sg, cmd->t_data_nents, SG_MITER_TO_SG);
 569         /*
 570          * Currently assumes NoLB=1 and SGLs are PAGE_SIZE..
 571          */
 572         while (len) {
 573                 sg_miter_next(&m);
 574
 575                 if (block_size < PAGE_SIZE) {
 576                         sg_set_page(&write_sg[i], m.page, block_size,
 577                                     m.piter.sg->offset + block_size);
 578                 } else {
 579                         sg_miter_next(&m);
 580                         sg_set_page(&write_sg[i], m.page, block_size,
 581                                     m.piter.sg->offset);
 582                 }
 583                 len -= block_size;
 584                 i++;
 585         }
 586         sg_miter_stop(&m);
 587         /*
 588          * Save the original SGL + nents values before updating to new
 589          * assignments, to be released in transport_free_pages() ->
 590          * transport_reset_sgl_orig()
 591          */
 592         cmd->t_data_sg_orig = cmd->t_data_sg;
 593         cmd->t_data_sg = write_sg;
 594         cmd->t_data_nents_orig = cmd->t_data_nents;
 595         cmd->t_data_nents = 1;
 596
 597         cmd->sam_task_attr = TCM_HEAD_TAG;
 598         cmd->transport_complete_callback = compare_and_write_post;
 599         /*
 600          * Now reset ->execute_cmd() to the normal sbc_execute_rw() handler
 601          * for submitting the adjusted SGL to write instance user-data.
 602          */
 603         cmd->execute_cmd = sbc_execute_rw;
 604
 605         spin_lock_irq(&cmd->t_state_lock);
 606         cmd->t_state = TRANSPORT_PROCESSING;
 607         cmd->transport_state |= CMD_T_ACTIVE | CMD_T_SENT;
 608         spin_unlock_irq(&cmd->t_state_lock);
 609
 610         __target_execute_cmd(cmd, false);
 611
 612         kfree(buf);
 613         return ret;
 614
 615 miscompare:
 616         pr_warn("Target/%s: Send MISCOMPARE check condition and sense\n",
 617                 dev->transport->name);
 618         ret = TCM_MISCOMPARE_VERIFY;
 619 out:
 620         /*
 621          * In the MISCOMPARE or failure case, unlock ->caw_sem obtained in
 622          * sbc_compare_and_write() before the original READ I/O submission.
 623          */
 624         up(&dev->caw_sem);
 625         kfree(write_sg);
 626         kfree(buf);
 627         return ret;
 628 }
 629
 630 static sense_reason_t
 631 sbc_compare_and_write(struct se_cmd *cmd)
 632 {
 633         struct sbc_ops *ops = cmd->protocol_data;
 634         struct se_device *dev = cmd->se_dev;
 635         sense_reason_t ret;
 636         int rc;
 637         /*
 638          * Submit the READ first for COMPARE_AND_WRITE to perform the
 639          * comparision using SGLs at cmd->t_bidi_data_sg..
 640          */
 641         rc = down_interruptible(&dev->caw_sem);
 642         if (rc != 0) {
 643                 cmd->transport_complete_callback = NULL;
 644                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 645         }
 646         /*
 647          * Reset cmd->data_length to individual block_size in order to not
 648          * confuse backend drivers that depend on this value matching the
 649          * size of the I/O being submitted.
 650          */
 651         cmd->data_length = cmd->t_task_nolb * dev->dev_attrib.block_size;
 652
 653         ret = ops->execute_rw(cmd, cmd->t_bidi_data_sg, cmd->t_bidi_data_nents,
 654                               DMA_FROM_DEVICE);
 655         if (ret) {
 656                 cmd->transport_complete_callback = NULL;
 657                 up(&dev->caw_sem);
 658                 return ret;
 659         }
 660         /*
 661          * Unlock of dev->caw_sem to occur in compare_and_write_callback()
 662          * upon MISCOMPARE, or in compare_and_write_done() upon completion
 663          * of WRITE instance user-data.
 664          */
 665         return TCM_NO_SENSE;
 666 }
 667
 668 static int
 669 sbc_set_prot_op_checks(u8 protect, bool fabric_prot, enum target_prot_type prot_type,
 670                        bool is_write, struct se_cmd *cmd)
 671 {
 672         if (is_write) {
 673                 cmd->prot_op = fabric_prot ? TARGET_PROT_DOUT_STRIP :
 674                                protect ? TARGET_PROT_DOUT_PASS :
 675                                TARGET_PROT_DOUT_INSERT;
 676                 switch (protect) {
 677                 case 0x0:
 678                 case 0x3:
 679                         cmd->prot_checks = 0;
 680                         break;
 681                 case 0x1:
 682                 case 0x5:
 683                         cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
 684                         if (prot_type == TARGET_DIF_TYPE1_PROT)
 685                                 cmd->prot_checks |= TARGET_DIF_CHECK_REFTAG;
 686                         break;
 687                 case 0x2:
 688                         if (prot_type == TARGET_DIF_TYPE1_PROT)
 689                                 cmd->prot_checks = TARGET_DIF_CHECK_REFTAG;
 690                         break;
 691                 case 0x4:
 692                         cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
 693                         break;
 694                 default:
 695                         pr_err("Unsupported protect field %d\n", protect);
 696                         return -EINVAL;
 697                 }
 698         } else {
 699                 cmd->prot_op = fabric_prot ? TARGET_PROT_DIN_INSERT :
 700                                protect ? TARGET_PROT_DIN_PASS :
 701                                TARGET_PROT_DIN_STRIP;
 702                 switch (protect) {
 703                 case 0x0:
 704                 case 0x1:
 705                 case 0x5:
 706                         cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
 707                         if (prot_type == TARGET_DIF_TYPE1_PROT)
 708                                 cmd->prot_checks |= TARGET_DIF_CHECK_REFTAG;
 709                         break;
 710                 case 0x2:
 711                         if (prot_type == TARGET_DIF_TYPE1_PROT)
 712                                 cmd->prot_checks = TARGET_DIF_CHECK_REFTAG;
 713                         break;
 714                 case 0x3:
 715                         cmd->prot_checks = 0;
 716                         break;
 717                 case 0x4:
 718                         cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
 719                         break;
 720                 default:
 721                         pr_err("Unsupported protect field %d\n", protect);
 722                         return -EINVAL;
 723                 }
 724         }
 725
 726         return 0;
 727 }
 728
 729 static sense_reason_t
 730 sbc_check_prot(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb,
 731                u32 sectors, bool is_write)
 732 {
 733         u8 protect = cdb[1] >> 5;
 734         int sp_ops = cmd->se_sess->sup_prot_ops;
 735         int pi_prot_type = dev->dev_attrib.pi_prot_type;
 736         bool fabric_prot = false;
 737
 738         if (!cmd->t_prot_sg || !cmd->t_prot_nents) {
 739                 if (unlikely(protect &&
 740                     !dev->dev_attrib.pi_prot_type && !cmd->se_sess->sess_prot_type)) {
 741                         pr_err("CDB contains protect bit, but device + fabric does"
 742                                " not advertise PROTECT=1 feature bit\n");
 743                         return TCM_INVALID_CDB_FIELD;
 744                 }
 745                 if (cmd->prot_pto)
 746                         return TCM_NO_SENSE;
 747         }
 748
 749         switch (dev->dev_attrib.pi_prot_type) {
 750         case TARGET_DIF_TYPE3_PROT:
 751                 cmd->reftag_seed = 0xffffffff;
 752                 break;
 753         case TARGET_DIF_TYPE2_PROT:
 754                 if (protect)
 755                         return TCM_INVALID_CDB_FIELD;
 756
 757                 cmd->reftag_seed = cmd->t_task_lba;
 758                 break;
 759         case TARGET_DIF_TYPE1_PROT:
 760                 cmd->reftag_seed = cmd->t_task_lba;
 761                 break;
 762         case TARGET_DIF_TYPE0_PROT:
 763                 /*
 764                  * See if the fabric supports T10-PI, and the session has been
 765                  * configured to allow export PROTECT=1 feature bit with backend
 766                  * devices that don't support T10-PI.
 767                  */
 768                 fabric_prot = is_write ?
 769                               !!(sp_ops & (TARGET_PROT_DOUT_PASS | TARGET_PROT_DOUT_STRIP)) :
 770                               !!(sp_ops & (TARGET_PROT_DIN_PASS | TARGET_PROT_DIN_INSERT));
 771
 772                 if (fabric_prot && cmd->se_sess->sess_prot_type) {
 773                         pi_prot_type = cmd->se_sess->sess_prot_type;
 774                         break;
 775                 }
 776                 if (!protect)
 777                         return TCM_NO_SENSE;
 778                 /* Fallthrough */
 779         default:
 780                 pr_err("Unable to determine pi_prot_type for CDB: 0x%02x "
 781                        "PROTECT: 0x%02x\n", cdb[0], protect);
 782                 return TCM_INVALID_CDB_FIELD;
 783         }
 784
 785         if (sbc_set_prot_op_checks(protect, fabric_prot, pi_prot_type, is_write, cmd))
 786                 return TCM_INVALID_CDB_FIELD;
 787
 788         cmd->prot_type = pi_prot_type;
 789         cmd->prot_length = dev->prot_length * sectors;
 790
 791         /**
 792          * In case protection information exists over the wire
 793          * we modify command data length to describe pure data.
 794          * The actual transfer length is data length + protection
 795          * length
 796          **/
 797         if (protect)
 798                 cmd->data_length = sectors * dev->dev_attrib.block_size;
 799
 800         pr_debug("%s: prot_type=%d, data_length=%d, prot_length=%d "
 801                  "prot_op=%d prot_checks=%d\n",
 802                  __func__, cmd->prot_type, cmd->data_length, cmd->prot_length,
 803                  cmd->prot_op, cmd->prot_checks);
 804
 805         return TCM_NO_SENSE;
 806 }
 807
 808 static int
 809 sbc_check_dpofua(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb)
 810 {
 811         if (cdb[1] & 0x10) {
 812                 /* see explanation in spc_emulate_modesense */
 813                 if (!target_check_fua(dev)) {
 814                         pr_err("Got CDB: 0x%02x with DPO bit set, but device"
 815                                " does not advertise support for DPO\n", cdb[0]);
 816                         return -EINVAL;
 817                 }
 818         }
 819         if (cdb[1] & 0x8) {
 820                 if (!target_check_fua(dev)) {
 821                         pr_err("Got CDB: 0x%02x with FUA bit set, but device"
 822                                " does not advertise support for FUA write\n",
 823                                cdb[0]);
 824                         return -EINVAL;
 825                 }
 826                 cmd->se_cmd_flags |= SCF_FUA;
 827         }
 828         return 0;
 829 }
 830
 831 sense_reason_t
 832 sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
 833 {
 834         struct se_device *dev = cmd->se_dev;
 835         unsigned char *cdb = cmd->t_task_cdb;
 836         unsigned int size;
 837         u32 sectors = 0;
 838         sense_reason_t ret;
 839
 840         cmd->protocol_data = ops;
 841
 842         switch (cdb[0]) {
 843         case READ_6:
 844                 sectors = transport_get_sectors_6(cdb);
 845                 cmd->t_task_lba = transport_lba_21(cdb);
 846                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 847                 cmd->execute_cmd = sbc_execute_rw;
 848                 break;
 849         case READ_10:
 850                 sectors = transport_get_sectors_10(cdb);
 851                 cmd->t_task_lba = transport_lba_32(cdb);
 852
 853                 if (sbc_check_dpofua(dev, cmd, cdb))
 854                         return TCM_INVALID_CDB_FIELD;
 855
 856                 ret = sbc_check_prot(dev, cmd, cdb, sectors, false);
 857                 if (ret)
 858                         return ret;
 859
 860                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 861                 cmd->execute_cmd = sbc_execute_rw;
 862                 break;
 863         case READ_12:
 864                 sectors = transport_get_sectors_12(cdb);
 865                 cmd->t_task_lba = transport_lba_32(cdb);
 866
 867                 if (sbc_check_dpofua(dev, cmd, cdb))
 868                         return TCM_INVALID_CDB_FIELD;
 869
 870                 ret = sbc_check_prot(dev, cmd, cdb, sectors, false);
 871                 if (ret)
 872                         return ret;
 873
 874                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 875                 cmd->execute_cmd = sbc_execute_rw;
 876                 break;
 877         case READ_16:
 878                 sectors = transport_get_sectors_16(cdb);
 879                 cmd->t_task_lba = transport_lba_64(cdb);
 880
 881                 if (sbc_check_dpofua(dev, cmd, cdb))
 882                         return TCM_INVALID_CDB_FIELD;
 883
 884                 ret = sbc_check_prot(dev, cmd, cdb, sectors, false);
 885                 if (ret)
 886                         return ret;
 887
 888                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 889                 cmd->execute_cmd = sbc_execute_rw;
 890                 break;
 891         case WRITE_6:
 892                 sectors = transport_get_sectors_6(cdb);
 893                 cmd->t_task_lba = transport_lba_21(cdb);
 894                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 895                 cmd->execute_cmd = sbc_execute_rw;
 896                 break;
 897         case WRITE_10:
 898         case WRITE_VERIFY:
 899                 sectors = transport_get_sectors_10(cdb);
 900                 cmd->t_task_lba = transport_lba_32(cdb);
 901
 902                 if (sbc_check_dpofua(dev, cmd, cdb))
 903                         return TCM_INVALID_CDB_FIELD;
 904
 905                 ret = sbc_check_prot(dev, cmd, cdb, sectors, true);
 906                 if (ret)
 907                         return ret;
 908
 909                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 910                 cmd->execute_cmd = sbc_execute_rw;
 911                 break;
 912         case WRITE_12:
 913                 sectors = transport_get_sectors_12(cdb);
 914                 cmd->t_task_lba = transport_lba_32(cdb);
 915
 916                 if (sbc_check_dpofua(dev, cmd, cdb))
 917                         return TCM_INVALID_CDB_FIELD;
 918
 919                 ret = sbc_check_prot(dev, cmd, cdb, sectors, true);
 920                 if (ret)
 921                         return ret;
 922
 923                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 924                 cmd->execute_cmd = sbc_execute_rw;
 925                 break;
 926         case WRITE_16:
 927                 sectors = transport_get_sectors_16(cdb);
 928                 cmd->t_task_lba = transport_lba_64(cdb);
 929
 930                 if (sbc_check_dpofua(dev, cmd, cdb))
 931                         return TCM_INVALID_CDB_FIELD;
 932
 933                 ret = sbc_check_prot(dev, cmd, cdb, sectors, true);
 934                 if (ret)
 935                         return ret;
 936
 937                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 938                 cmd->execute_cmd = sbc_execute_rw;
 939                 break;
 940         case XDWRITEREAD_10:
 941                 if (cmd->data_direction != DMA_TO_DEVICE ||
 942                     !(cmd->se_cmd_flags & SCF_BIDI))
 943                         return TCM_INVALID_CDB_FIELD;
 944                 sectors = transport_get_sectors_10(cdb);
 945
 946                 if (sbc_check_dpofua(dev, cmd, cdb))
 947                         return TCM_INVALID_CDB_FIELD;
 948
 949                 cmd->t_task_lba = transport_lba_32(cdb);
 950                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 951
 952                 /*
 953                  * Setup BIDI XOR callback to be run after I/O completion.
 954                  */
 955                 cmd->execute_cmd = sbc_execute_rw;
 956                 cmd->transport_complete_callback = &xdreadwrite_callback;
 957                 break;
 958         case VARIABLE_LENGTH_CMD:
 959         {
 960                 u16 service_action = get_unaligned_be16(&cdb[8]);
 961                 switch (service_action) {
 962                 case XDWRITEREAD_32:
 963                         sectors = transport_get_sectors_32(cdb);
 964
 965                         if (sbc_check_dpofua(dev, cmd, cdb))
 966                                 return TCM_INVALID_CDB_FIELD;
 967                         /*
 968                          * Use WRITE_32 and READ_32 opcodes for the emulated
 969                          * XDWRITE_READ_32 logic.
 970                          */
 971                         cmd->t_task_lba = transport_lba_64_ext(cdb);
 972                         cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 973
 974                         /*
 975                          * Setup BIDI XOR callback to be run during after I/O
 976                          * completion.
 977                          */
 978                         cmd->execute_cmd = sbc_execute_rw;
 979                         cmd->transport_complete_callback = &xdreadwrite_callback;
 980                         break;
 981                 case WRITE_SAME_32:
 982                         sectors = transport_get_sectors_32(cdb);
 983                         if (!sectors) {
 984                                 pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not"
 985                                        " supported\n");
 986                                 return TCM_INVALID_CDB_FIELD;
 987                         }
 988
 989                         size = sbc_get_size(cmd, 1);
 990                         cmd->t_task_lba = get_unaligned_be64(&cdb[12]);
 991
 992                         ret = sbc_setup_write_same(cmd, &cdb[10], ops);
 993                         if (ret)
 994                                 return ret;
 995                         break;
 996                 default:
 997                         pr_err("VARIABLE_LENGTH_CMD service action"
 998                                 " 0x%04x not supported\n", service_action);
 999                         return TCM_UNSUPPORTED_SCSI_OPCODE;
1000                 }
1001                 break;
1002         }
1003         case COMPARE_AND_WRITE:
1004                 sectors = cdb[13];
1005                 /*
1006                  * Currently enforce COMPARE_AND_WRITE for a single sector
1007                  */
1008                 if (sectors > 1) {
1009                         pr_err("COMPARE_AND_WRITE contains NoLB: %u greater"
1010                                " than 1\n", sectors);
1011                         return TCM_INVALID_CDB_FIELD;
1012                 }
1013                 if (sbc_check_dpofua(dev, cmd, cdb))
1014                         return TCM_INVALID_CDB_FIELD;
1015
1016                 /*
1017                  * Double size because we have two buffers, note that
1018                  * zero is not an error..
1019                  */
1020                 size = 2 * sbc_get_size(cmd, sectors);
1021                 cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
1022                 cmd->t_task_nolb = sectors;
1023                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB | SCF_COMPARE_AND_WRITE;
1024                 cmd->execute_cmd = sbc_compare_and_write;
1025                 cmd->transport_complete_callback = compare_and_write_callback;
1026                 break;
1027         case READ_CAPACITY:
1028                 size = READ_CAP_LEN;
1029                 cmd->execute_cmd = sbc_emulate_readcapacity;
1030                 break;
1031         case SERVICE_ACTION_IN_16:
1032                 switch (cmd->t_task_cdb[1] & 0x1f) {
1033                 case SAI_READ_CAPACITY_16:
1034                         cmd->execute_cmd = sbc_emulate_readcapacity_16;
1035                         break;
1036                 case SAI_REPORT_REFERRALS:
1037                         cmd->execute_cmd = target_emulate_report_referrals;
1038                         break;
1039                 default:
1040                         pr_err("Unsupported SA: 0x%02x\n",
1041                                 cmd->t_task_cdb[1] & 0x1f);
1042                         return TCM_INVALID_CDB_FIELD;
1043                 }
1044                 size = (cdb[10] << 24) | (cdb[11] << 16) |
1045                        (cdb[12] << 8) | cdb[13];
1046                 break;
1047         case SYNCHRONIZE_CACHE:
1048         case SYNCHRONIZE_CACHE_16:
1049                 if (cdb[0] == SYNCHRONIZE_CACHE) {
1050                         sectors = transport_get_sectors_10(cdb);
1051                         cmd->t_task_lba = transport_lba_32(cdb);
1052                 } else {
1053                         sectors = transport_get_sectors_16(cdb);
1054                         cmd->t_task_lba = transport_lba_64(cdb);
1055                 }
1056                 if (ops->execute_sync_cache) {
1057                         cmd->execute_cmd = ops->execute_sync_cache;
1058                         goto check_lba;
1059                 }
1060                 size = 0;
1061                 cmd->execute_cmd = sbc_emulate_noop;
1062                 break;
1063         case UNMAP:
1064                 if (!ops->execute_unmap)
1065                         return TCM_UNSUPPORTED_SCSI_OPCODE;
1066
1067                 if (!dev->dev_attrib.emulate_tpu) {
1068                         pr_err("Got UNMAP, but backend device has"
1069                                " emulate_tpu disabled\n");
1070                         return TCM_UNSUPPORTED_SCSI_OPCODE;
1071                 }
1072                 size = get_unaligned_be16(&cdb[7]);
1073                 cmd->execute_cmd = sbc_execute_unmap;
1074                 break;
1075         case WRITE_SAME_16:
1076                 sectors = transport_get_sectors_16(cdb);
1077                 if (!sectors) {
1078                         pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
1079                         return TCM_INVALID_CDB_FIELD;
1080                 }
1081
1082                 size = sbc_get_size(cmd, 1);
1083                 cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
1084
1085                 ret = sbc_setup_write_same(cmd, &cdb[1], ops);
1086                 if (ret)
1087                         return ret;
1088                 break;
1089         case WRITE_SAME:
1090                 sectors = transport_get_sectors_10(cdb);
1091                 if (!sectors) {
1092                         pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
1093                         return TCM_INVALID_CDB_FIELD;
1094                 }
1095
1096                 size = sbc_get_size(cmd, 1);
1097                 cmd->t_task_lba = get_unaligned_be32(&cdb[2]);
1098
1099                 /*
1100                  * Follow sbcr26 with WRITE_SAME (10) and check for the existence
1101                  * of byte 1 bit 3 UNMAP instead of original reserved field
1102                  */
1103                 ret = sbc_setup_write_same(cmd, &cdb[1], ops);
1104                 if (ret)
1105                         return ret;
1106                 break;
1107         case VERIFY:
1108                 size = 0;
1109                 sectors = transport_get_sectors_10(cdb);
1110                 cmd->t_task_lba = transport_lba_32(cdb);
1111                 cmd->execute_cmd = sbc_emulate_noop;
1112                 goto check_lba;
1113         case REZERO_UNIT:
1114         case SEEK_6:
1115         case SEEK_10:
1116                 /*
1117                  * There are still clients out there which use these old SCSI-2
1118                  * commands. This mainly happens when running VMs with legacy
1119                  * guest systems, connected via SCSI command pass-through to
1120                  * iSCSI targets. Make them happy and return status GOOD.
1121                  */
1122                 size = 0;
1123                 cmd->execute_cmd = sbc_emulate_noop;
1124                 break;
1125         case START_STOP:
1126                 size = 0;
1127                 cmd->execute_cmd = sbc_emulate_startstop;
1128                 break;
1129         default:
1130                 ret = spc_parse_cdb(cmd, &size);
1131                 if (ret)
1132                         return ret;
1133         }
1134
1135         /* reject any command that we don't have a handler for */
1136         if (!cmd->execute_cmd)
1137                 return TCM_UNSUPPORTED_SCSI_OPCODE;
1138
1139         if (cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
1140                 unsigned long long end_lba;
1141 check_lba:
1142                 end_lba = dev->transport->get_blocks(dev) + 1;
1143                 if (((cmd->t_task_lba + sectors) < cmd->t_task_lba) ||
1144                     ((cmd->t_task_lba + sectors) > end_lba)) {
1145                         pr_err("cmd exceeds last lba %llu "
1146                                 "(lba %llu, sectors %u)\n",
1147                                 end_lba, cmd->t_task_lba, sectors);
1148                         return TCM_ADDRESS_OUT_OF_RANGE;
1149                 }
1150
1151                 if (!(cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE))
1152                         size = sbc_get_size(cmd, sectors);
1153         }
1154
1155         return target_cmd_size_check(cmd, size);
1156 }
1157 EXPORT_SYMBOL(sbc_parse_cdb);
1158
1159 u32 sbc_get_device_type(struct se_device *dev)
1160 {
1161         return TYPE_DISK;
1162 }
1163 EXPORT_SYMBOL(sbc_get_device_type);
1164
1165 static sense_reason_t
1166 sbc_execute_unmap(struct se_cmd *cmd)
1167 {
1168         struct sbc_ops *ops = cmd->protocol_data;
1169         struct se_device *dev = cmd->se_dev;
1170         unsigned char *buf, *ptr = NULL;
1171         sector_t lba;
1172         int size;
1173         u32 range;
1174         sense_reason_t ret = 0;
1175         int dl, bd_dl;
1176
1177         /* We never set ANC_SUP */
1178         if (cmd->t_task_cdb[1])
1179                 return TCM_INVALID_CDB_FIELD;
1180
1181         if (cmd->data_length == 0) {
1182                 target_complete_cmd(cmd, SAM_STAT_GOOD);
1183                 return 0;
1184         }
1185
1186         if (cmd->data_length < 8) {
1187                 pr_warn("UNMAP parameter list length %u too small\n",
1188                         cmd->data_length);
1189                 return TCM_PARAMETER_LIST_LENGTH_ERROR;
1190         }
1191
1192         buf = transport_kmap_data_sg(cmd);
1193         if (!buf)
1194                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1195
1196         dl = get_unaligned_be16(&buf[0]);
1197         bd_dl = get_unaligned_be16(&buf[2]);
1198
1199         size = cmd->data_length - 8;
1200         if (bd_dl > size)
1201                 pr_warn("UNMAP parameter list length %u too small, ignoring bd_dl %u\n",
1202                         cmd->data_length, bd_dl);
1203         else
1204                 size = bd_dl;
1205
1206         if (size / 16 > dev->dev_attrib.max_unmap_block_desc_count) {
1207                 ret = TCM_INVALID_PARAMETER_LIST;
1208                 goto err;
1209         }
1210
1211         /* First UNMAP block descriptor starts at 8 byte offset */
1212         ptr = &buf[8];
1213         pr_debug("UNMAP: Sub: %s Using dl: %u bd_dl: %u size: %u"
1214                 " ptr: %p\n", dev->transport->name, dl, bd_dl, size, ptr);
1215
1216         while (size >= 16) {
1217                 lba = get_unaligned_be64(&ptr[0]);
1218                 range = get_unaligned_be32(&ptr[8]);
1219                 pr_debug("UNMAP: Using lba: %llu and range: %u\n",
1220                                  (unsigned long long)lba, range);
1221
1222                 if (range > dev->dev_attrib.max_unmap_lba_count) {
1223                         ret = TCM_INVALID_PARAMETER_LIST;
1224                         goto err;
1225                 }
1226
1227                 if (lba + range > dev->transport->get_blocks(dev) + 1) {
1228                         ret = TCM_ADDRESS_OUT_OF_RANGE;
1229                         goto err;
1230                 }
1231
1232                 ret = ops->execute_unmap(cmd, lba, range);
1233                 if (ret)
1234                         goto err;
1235
1236                 ptr += 16;
1237                 size -= 16;
1238         }
1239
1240 err:
1241         transport_kunmap_data_sg(cmd);
1242         if (!ret)
1243                 target_complete_cmd(cmd, GOOD);
1244         return ret;
1245 }
1246
1247 void
1248 sbc_dif_generate(struct se_cmd *cmd)
1249 {
1250         struct se_device *dev = cmd->se_dev;
1251         struct t10_pi_tuple *sdt;
1252         struct scatterlist *dsg = cmd->t_data_sg, *psg;
1253         sector_t sector = cmd->t_task_lba;
1254         void *daddr, *paddr;
1255         int i, j, offset = 0;
1256         unsigned int block_size = dev->dev_attrib.block_size;
1257
1258         for_each_sg(cmd->t_prot_sg, psg, cmd->t_prot_nents, i) {
1259                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1260                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1261
1262                 for (j = 0; j < psg->length;
1263                                 j += sizeof(*sdt)) {
1264                         __u16 crc;
1265                         unsigned int avail;
1266
1267                         if (offset >= dsg->length) {
1268                                 offset -= dsg->length;
1269                                 kunmap_atomic(daddr - dsg->offset);
1270                                 dsg = sg_next(dsg);
1271                                 if (!dsg) {
1272                                         kunmap_atomic(paddr - psg->offset);
1273                                         return;
1274                                 }
1275                                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1276                         }
1277
1278                         sdt = paddr + j;
1279                         avail = min(block_size, dsg->length - offset);
1280                         crc = crc_t10dif(daddr + offset, avail);
1281                         if (avail < block_size) {
1282                                 kunmap_atomic(daddr - dsg->offset);
1283                                 dsg = sg_next(dsg);
1284                                 if (!dsg) {
1285                                         kunmap_atomic(paddr - psg->offset);
1286                                         return;
1287                                 }
1288                                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1289                                 offset = block_size - avail;
1290                                 crc = crc_t10dif_update(crc, daddr, offset);
1291                         } else {
1292                                 offset += block_size;
1293                         }
1294
1295                         sdt->guard_tag = cpu_to_be16(crc);
1296                         if (cmd->prot_type == TARGET_DIF_TYPE1_PROT)
1297                                 sdt->ref_tag = cpu_to_be32(sector & 0xffffffff);
1298                         sdt->app_tag = 0;
1299
1300                         pr_debug("DIF %s INSERT sector: %llu guard_tag: 0x%04x"
1301                                  " app_tag: 0x%04x ref_tag: %u\n",
1302                                  (cmd->data_direction == DMA_TO_DEVICE) ?
1303                                  "WRITE" : "READ", (unsigned long long)sector,
1304                                  sdt->guard_tag, sdt->app_tag,
1305                                  be32_to_cpu(sdt->ref_tag));
1306
1307                         sector++;
1308                 }
1309
1310                 kunmap_atomic(daddr - dsg->offset);
1311                 kunmap_atomic(paddr - psg->offset);
1312         }
1313 }
1314
1315 static sense_reason_t
1316 sbc_dif_v1_verify(struct se_cmd *cmd, struct t10_pi_tuple *sdt,
1317                   __u16 crc, sector_t sector, unsigned int ei_lba)
1318 {
1319         __be16 csum;
1320
1321         if (!(cmd->prot_checks & TARGET_DIF_CHECK_GUARD))
1322                 goto check_ref;
1323
1324         csum = cpu_to_be16(crc);
1325
1326         if (sdt->guard_tag != csum) {
1327                 pr_err("DIFv1 checksum failed on sector %llu guard tag 0x%04x"
1328                         " csum 0x%04x\n", (unsigned long long)sector,
1329                         be16_to_cpu(sdt->guard_tag), be16_to_cpu(csum));
1330                 return TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED;
1331         }
1332
1333 check_ref:
1334         if (!(cmd->prot_checks & TARGET_DIF_CHECK_REFTAG))
1335                 return 0;
1336
1337         if (cmd->prot_type == TARGET_DIF_TYPE1_PROT &&
1338             be32_to_cpu(sdt->ref_tag) != (sector & 0xffffffff)) {
1339                 pr_err("DIFv1 Type 1 reference failed on sector: %llu tag: 0x%08x"
1340                        " sector MSB: 0x%08x\n", (unsigned long long)sector,
1341                        be32_to_cpu(sdt->ref_tag), (u32)(sector & 0xffffffff));
1342                 return TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;
1343         }
1344
1345         if (cmd->prot_type == TARGET_DIF_TYPE2_PROT &&
1346             be32_to_cpu(sdt->ref_tag) != ei_lba) {
1347                 pr_err("DIFv1 Type 2 reference failed on sector: %llu tag: 0x%08x"
1348                        " ei_lba: 0x%08x\n", (unsigned long long)sector,
1349                         be32_to_cpu(sdt->ref_tag), ei_lba);
1350                 return TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;
1351         }
1352
1353         return 0;
1354 }
1355
1356 void sbc_dif_copy_prot(struct se_cmd *cmd, unsigned int sectors, bool read,
1357                        struct scatterlist *sg, int sg_off)
1358 {
1359         struct se_device *dev = cmd->se_dev;
1360         struct scatterlist *psg;
1361         void *paddr, *addr;
1362         unsigned int i, len, left;
1363         unsigned int offset = sg_off;
1364
1365         if (!sg)
1366                 return;
1367
1368         left = sectors * dev->prot_length;
1369
1370         for_each_sg(cmd->t_prot_sg, psg, cmd->t_prot_nents, i) {
1371                 unsigned int psg_len, copied = 0;
1372
1373                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1374                 psg_len = min(left, psg->length);
1375                 while (psg_len) {
1376                         len = min(psg_len, sg->length - offset);
1377                         addr = kmap_atomic(sg_page(sg)) + sg->offset + offset;
1378
1379                         if (read)
1380                                 memcpy(paddr + copied, addr, len);
1381                         else
1382                                 memcpy(addr, paddr + copied, len);
1383
1384                         left -= len;
1385                         offset += len;
1386                         copied += len;
1387                         psg_len -= len;
1388
1389                         kunmap_atomic(addr - sg->offset - offset);
1390
1391                         if (offset >= sg->length) {
1392                                 sg = sg_next(sg);
1393                                 offset = 0;
1394                         }
1395                 }
1396                 kunmap_atomic(paddr - psg->offset);
1397         }
1398 }
1399 EXPORT_SYMBOL(sbc_dif_copy_prot);
1400
1401 sense_reason_t
1402 sbc_dif_verify(struct se_cmd *cmd, sector_t start, unsigned int sectors,
1403                unsigned int ei_lba, struct scatterlist *psg, int psg_off)
1404 {
1405         struct se_device *dev = cmd->se_dev;
1406         struct t10_pi_tuple *sdt;
1407         struct scatterlist *dsg = cmd->t_data_sg;
1408         sector_t sector = start;
1409         void *daddr, *paddr;
1410         int i;
1411         sense_reason_t rc;
1412         int dsg_off = 0;
1413         unsigned int block_size = dev->dev_attrib.block_size;
1414
1415         for (; psg && sector < start + sectors; psg = sg_next(psg)) {
1416                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1417                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1418
1419                 for (i = psg_off; i < psg->length &&
1420                                 sector < start + sectors;
1421                                 i += sizeof(*sdt)) {
1422                         __u16 crc;
1423                         unsigned int avail;
1424
1425                         if (dsg_off >= dsg->length) {
1426                                 dsg_off -= dsg->length;
1427                                 kunmap_atomic(daddr - dsg->offset);
1428                                 dsg = sg_next(dsg);
1429                                 if (!dsg) {
1430                                         kunmap_atomic(paddr - psg->offset);
1431                                         return 0;
1432                                 }
1433                                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1434                         }
1435
1436                         sdt = paddr + i;
1437
1438                         pr_debug("DIF READ sector: %llu guard_tag: 0x%04x"
1439                                  " app_tag: 0x%04x ref_tag: %u\n",
1440                                  (unsigned long long)sector, sdt->guard_tag,
1441                                  sdt->app_tag, be32_to_cpu(sdt->ref_tag));
1442
1443                         if (sdt->app_tag == cpu_to_be16(0xffff)) {
1444                                 dsg_off += block_size;
1445                                 goto next;
1446                         }
1447
1448                         avail = min(block_size, dsg->length - dsg_off);
1449                         crc = crc_t10dif(daddr + dsg_off, avail);
1450                         if (avail < block_size) {
1451                                 kunmap_atomic(daddr - dsg->offset);
1452                                 dsg = sg_next(dsg);
1453                                 if (!dsg) {
1454                                         kunmap_atomic(paddr - psg->offset);
1455                                         return 0;
1456                                 }
1457                                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1458                                 dsg_off = block_size - avail;
1459                                 crc = crc_t10dif_update(crc, daddr, dsg_off);
1460                         } else {
1461                                 dsg_off += block_size;
1462                         }
1463
1464                         rc = sbc_dif_v1_verify(cmd, sdt, crc, sector, ei_lba);
1465                         if (rc) {
1466                                 kunmap_atomic(daddr - dsg->offset);
1467                                 kunmap_atomic(paddr - psg->offset);
1468                                 cmd->bad_sector = sector;
1469                                 return rc;
1470                         }
1471 next:
1472                         sector++;
1473                         ei_lba++;
1474                 }
1475
1476                 psg_off = 0;
1477                 kunmap_atomic(daddr - dsg->offset);
1478                 kunmap_atomic(paddr - psg->offset);
1479         }
1480
1481         return 0;
1482 }
1483 EXPORT_SYMBOL(sbc_dif_verify);