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_debug("compare_and_write_callback: non zero scsi_status:"
 511                         " 0x%02x\n", cmd->scsi_status);
 512                 *post_ret = 1;
 513                 if (cmd->scsi_status == SAM_STAT_CHECK_CONDITION)
 514                         ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 515                 goto out;
 516         }
 517
 518         buf = kzalloc(cmd->data_length, GFP_KERNEL);
 519         if (!buf) {
 520                 pr_err("Unable to allocate compare_and_write buf\n");
 521                 ret = TCM_OUT_OF_RESOURCES;
 522                 goto out;
 523         }
 524
 525         write_sg = kmalloc_array(cmd->t_data_nents, sizeof(*write_sg),
 526                                  GFP_KERNEL);
 527         if (!write_sg) {
 528                 pr_err("Unable to allocate compare_and_write sg\n");
 529                 ret = TCM_OUT_OF_RESOURCES;
 530                 goto out;
 531         }
 532         sg_init_table(write_sg, cmd->t_data_nents);
 533         /*
 534          * Setup verify and write data payloads from total NumberLBAs.
 535          */
 536         rc = sg_copy_to_buffer(cmd->t_data_sg, cmd->t_data_nents, buf,
 537                                cmd->data_length);
 538         if (!rc) {
 539                 pr_err("sg_copy_to_buffer() failed for compare_and_write\n");
 540                 ret = TCM_OUT_OF_RESOURCES;
 541                 goto out;
 542         }
 543         /*
 544          * Compare against SCSI READ payload against verify payload
 545          */
 546         for_each_sg(cmd->t_bidi_data_sg, sg, cmd->t_bidi_data_nents, i) {
 547                 addr = (unsigned char *)kmap_atomic(sg_page(sg));
 548                 if (!addr) {
 549                         ret = TCM_OUT_OF_RESOURCES;
 550                         goto out;
 551                 }
 552
 553                 len = min(sg->length, compare_len);
 554
 555                 if (memcmp(addr, buf + offset, len)) {
 556                         pr_warn("Detected MISCOMPARE for addr: %p buf: %p\n",
 557                                 addr, buf + offset);
 558                         kunmap_atomic(addr);
 559                         goto miscompare;
 560                 }
 561                 kunmap_atomic(addr);
 562
 563                 offset += len;
 564                 compare_len -= len;
 565                 if (!compare_len)
 566                         break;
 567         }
 568
 569         i = 0;
 570         len = cmd->t_task_nolb * block_size;
 571         sg_miter_start(&m, cmd->t_data_sg, cmd->t_data_nents, SG_MITER_TO_SG);
 572         /*
 573          * Currently assumes NoLB=1 and SGLs are PAGE_SIZE..
 574          */
 575         while (len) {
 576                 sg_miter_next(&m);
 577
 578                 if (block_size < PAGE_SIZE) {
 579                         sg_set_page(&write_sg[i], m.page, block_size,
 580                                     m.piter.sg->offset + block_size);
 581                 } else {
 582                         sg_miter_next(&m);
 583                         sg_set_page(&write_sg[i], m.page, block_size,
 584                                     m.piter.sg->offset);
 585                 }
 586                 len -= block_size;
 587                 i++;
 588         }
 589         sg_miter_stop(&m);
 590         /*
 591          * Save the original SGL + nents values before updating to new
 592          * assignments, to be released in transport_free_pages() ->
 593          * transport_reset_sgl_orig()
 594          */
 595         cmd->t_data_sg_orig = cmd->t_data_sg;
 596         cmd->t_data_sg = write_sg;
 597         cmd->t_data_nents_orig = cmd->t_data_nents;
 598         cmd->t_data_nents = 1;
 599
 600         cmd->sam_task_attr = TCM_HEAD_TAG;
 601         cmd->transport_complete_callback = compare_and_write_post;
 602         /*
 603          * Now reset ->execute_cmd() to the normal sbc_execute_rw() handler
 604          * for submitting the adjusted SGL to write instance user-data.
 605          */
 606         cmd->execute_cmd = sbc_execute_rw;
 607
 608         spin_lock_irq(&cmd->t_state_lock);
 609         cmd->t_state = TRANSPORT_PROCESSING;
 610         cmd->transport_state |= CMD_T_ACTIVE | CMD_T_SENT;
 611         spin_unlock_irq(&cmd->t_state_lock);
 612
 613         __target_execute_cmd(cmd, false);
 614
 615         kfree(buf);
 616         return ret;
 617
 618 miscompare:
 619         pr_warn("Target/%s: Send MISCOMPARE check condition and sense\n",
 620                 dev->transport->name);
 621         ret = TCM_MISCOMPARE_VERIFY;
 622 out:
 623         /*
 624          * In the MISCOMPARE or failure case, unlock ->caw_sem obtained in
 625          * sbc_compare_and_write() before the original READ I/O submission.
 626          */
 627         up(&dev->caw_sem);
 628         kfree(write_sg);
 629         kfree(buf);
 630         return ret;
 631 }
 632
 633 static sense_reason_t
 634 sbc_compare_and_write(struct se_cmd *cmd)
 635 {
 636         struct sbc_ops *ops = cmd->protocol_data;
 637         struct se_device *dev = cmd->se_dev;
 638         sense_reason_t ret;
 639         int rc;
 640         /*
 641          * Submit the READ first for COMPARE_AND_WRITE to perform the
 642          * comparision using SGLs at cmd->t_bidi_data_sg..
 643          */
 644         rc = down_interruptible(&dev->caw_sem);
 645         if (rc != 0) {
 646                 cmd->transport_complete_callback = NULL;
 647                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 648         }
 649         /*
 650          * Reset cmd->data_length to individual block_size in order to not
 651          * confuse backend drivers that depend on this value matching the
 652          * size of the I/O being submitted.
 653          */
 654         cmd->data_length = cmd->t_task_nolb * dev->dev_attrib.block_size;
 655
 656         ret = ops->execute_rw(cmd, cmd->t_bidi_data_sg, cmd->t_bidi_data_nents,
 657                               DMA_FROM_DEVICE);
 658         if (ret) {
 659                 cmd->transport_complete_callback = NULL;
 660                 up(&dev->caw_sem);
 661                 return ret;
 662         }
 663         /*
 664          * Unlock of dev->caw_sem to occur in compare_and_write_callback()
 665          * upon MISCOMPARE, or in compare_and_write_done() upon completion
 666          * of WRITE instance user-data.
 667          */
 668         return TCM_NO_SENSE;
 669 }
 670
 671 static int
 672 sbc_set_prot_op_checks(u8 protect, bool fabric_prot, enum target_prot_type prot_type,
 673                        bool is_write, struct se_cmd *cmd)
 674 {
 675         if (is_write) {
 676                 cmd->prot_op = fabric_prot ? TARGET_PROT_DOUT_STRIP :
 677                                protect ? TARGET_PROT_DOUT_PASS :
 678                                TARGET_PROT_DOUT_INSERT;
 679                 switch (protect) {
 680                 case 0x0:
 681                 case 0x3:
 682                         cmd->prot_checks = 0;
 683                         break;
 684                 case 0x1:
 685                 case 0x5:
 686                         cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
 687                         if (prot_type == TARGET_DIF_TYPE1_PROT)
 688                                 cmd->prot_checks |= TARGET_DIF_CHECK_REFTAG;
 689                         break;
 690                 case 0x2:
 691                         if (prot_type == TARGET_DIF_TYPE1_PROT)
 692                                 cmd->prot_checks = TARGET_DIF_CHECK_REFTAG;
 693                         break;
 694                 case 0x4:
 695                         cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
 696                         break;
 697                 default:
 698                         pr_err("Unsupported protect field %d\n", protect);
 699                         return -EINVAL;
 700                 }
 701         } else {
 702                 cmd->prot_op = fabric_prot ? TARGET_PROT_DIN_INSERT :
 703                                protect ? TARGET_PROT_DIN_PASS :
 704                                TARGET_PROT_DIN_STRIP;
 705                 switch (protect) {
 706                 case 0x0:
 707                 case 0x1:
 708                 case 0x5:
 709                         cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
 710                         if (prot_type == TARGET_DIF_TYPE1_PROT)
 711                                 cmd->prot_checks |= TARGET_DIF_CHECK_REFTAG;
 712                         break;
 713                 case 0x2:
 714                         if (prot_type == TARGET_DIF_TYPE1_PROT)
 715                                 cmd->prot_checks = TARGET_DIF_CHECK_REFTAG;
 716                         break;
 717                 case 0x3:
 718                         cmd->prot_checks = 0;
 719                         break;
 720                 case 0x4:
 721                         cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
 722                         break;
 723                 default:
 724                         pr_err("Unsupported protect field %d\n", protect);
 725                         return -EINVAL;
 726                 }
 727         }
 728
 729         return 0;
 730 }
 731
 732 static sense_reason_t
 733 sbc_check_prot(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb,
 734                u32 sectors, bool is_write)
 735 {
 736         u8 protect = cdb[1] >> 5;
 737         int sp_ops = cmd->se_sess->sup_prot_ops;
 738         int pi_prot_type = dev->dev_attrib.pi_prot_type;
 739         bool fabric_prot = false;
 740
 741         if (!cmd->t_prot_sg || !cmd->t_prot_nents) {
 742                 if (unlikely(protect &&
 743                     !dev->dev_attrib.pi_prot_type && !cmd->se_sess->sess_prot_type)) {
 744                         pr_err("CDB contains protect bit, but device + fabric does"
 745                                " not advertise PROTECT=1 feature bit\n");
 746                         return TCM_INVALID_CDB_FIELD;
 747                 }
 748                 if (cmd->prot_pto)
 749                         return TCM_NO_SENSE;
 750         }
 751
 752         switch (dev->dev_attrib.pi_prot_type) {
 753         case TARGET_DIF_TYPE3_PROT:
 754                 cmd->reftag_seed = 0xffffffff;
 755                 break;
 756         case TARGET_DIF_TYPE2_PROT:
 757                 if (protect)
 758                         return TCM_INVALID_CDB_FIELD;
 759
 760                 cmd->reftag_seed = cmd->t_task_lba;
 761                 break;
 762         case TARGET_DIF_TYPE1_PROT:
 763                 cmd->reftag_seed = cmd->t_task_lba;
 764                 break;
 765         case TARGET_DIF_TYPE0_PROT:
 766                 /*
 767                  * See if the fabric supports T10-PI, and the session has been
 768                  * configured to allow export PROTECT=1 feature bit with backend
 769                  * devices that don't support T10-PI.
 770                  */
 771                 fabric_prot = is_write ?
 772                               !!(sp_ops & (TARGET_PROT_DOUT_PASS | TARGET_PROT_DOUT_STRIP)) :
 773                               !!(sp_ops & (TARGET_PROT_DIN_PASS | TARGET_PROT_DIN_INSERT));
 774
 775                 if (fabric_prot && cmd->se_sess->sess_prot_type) {
 776                         pi_prot_type = cmd->se_sess->sess_prot_type;
 777                         break;
 778                 }
 779                 if (!protect)
 780                         return TCM_NO_SENSE;
 781                 /* Fallthrough */
 782         default:
 783                 pr_err("Unable to determine pi_prot_type for CDB: 0x%02x "
 784                        "PROTECT: 0x%02x\n", cdb[0], protect);
 785                 return TCM_INVALID_CDB_FIELD;
 786         }
 787
 788         if (sbc_set_prot_op_checks(protect, fabric_prot, pi_prot_type, is_write, cmd))
 789                 return TCM_INVALID_CDB_FIELD;
 790
 791         cmd->prot_type = pi_prot_type;
 792         cmd->prot_length = dev->prot_length * sectors;
 793
 794         /**
 795          * In case protection information exists over the wire
 796          * we modify command data length to describe pure data.
 797          * The actual transfer length is data length + protection
 798          * length
 799          **/
 800         if (protect)
 801                 cmd->data_length = sectors * dev->dev_attrib.block_size;
 802
 803         pr_debug("%s: prot_type=%d, data_length=%d, prot_length=%d "
 804                  "prot_op=%d prot_checks=%d\n",
 805                  __func__, cmd->prot_type, cmd->data_length, cmd->prot_length,
 806                  cmd->prot_op, cmd->prot_checks);
 807
 808         return TCM_NO_SENSE;
 809 }
 810
 811 static int
 812 sbc_check_dpofua(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb)
 813 {
 814         if (cdb[1] & 0x10) {
 815                 /* see explanation in spc_emulate_modesense */
 816                 if (!target_check_fua(dev)) {
 817                         pr_err("Got CDB: 0x%02x with DPO bit set, but device"
 818                                " does not advertise support for DPO\n", cdb[0]);
 819                         return -EINVAL;
 820                 }
 821         }
 822         if (cdb[1] & 0x8) {
 823                 if (!target_check_fua(dev)) {
 824                         pr_err("Got CDB: 0x%02x with FUA bit set, but device"
 825                                " does not advertise support for FUA write\n",
 826                                cdb[0]);
 827                         return -EINVAL;
 828                 }
 829                 cmd->se_cmd_flags |= SCF_FUA;
 830         }
 831         return 0;
 832 }
 833
 834 sense_reason_t
 835 sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
 836 {
 837         struct se_device *dev = cmd->se_dev;
 838         unsigned char *cdb = cmd->t_task_cdb;
 839         unsigned int size;
 840         u32 sectors = 0;
 841         sense_reason_t ret;
 842
 843         cmd->protocol_data = ops;
 844
 845         switch (cdb[0]) {
 846         case READ_6:
 847                 sectors = transport_get_sectors_6(cdb);
 848                 cmd->t_task_lba = transport_lba_21(cdb);
 849                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 850                 cmd->execute_cmd = sbc_execute_rw;
 851                 break;
 852         case READ_10:
 853                 sectors = transport_get_sectors_10(cdb);
 854                 cmd->t_task_lba = transport_lba_32(cdb);
 855
 856                 if (sbc_check_dpofua(dev, cmd, cdb))
 857                         return TCM_INVALID_CDB_FIELD;
 858
 859                 ret = sbc_check_prot(dev, cmd, cdb, sectors, false);
 860                 if (ret)
 861                         return ret;
 862
 863                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 864                 cmd->execute_cmd = sbc_execute_rw;
 865                 break;
 866         case READ_12:
 867                 sectors = transport_get_sectors_12(cdb);
 868                 cmd->t_task_lba = transport_lba_32(cdb);
 869
 870                 if (sbc_check_dpofua(dev, cmd, cdb))
 871                         return TCM_INVALID_CDB_FIELD;
 872
 873                 ret = sbc_check_prot(dev, cmd, cdb, sectors, false);
 874                 if (ret)
 875                         return ret;
 876
 877                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 878                 cmd->execute_cmd = sbc_execute_rw;
 879                 break;
 880         case READ_16:
 881                 sectors = transport_get_sectors_16(cdb);
 882                 cmd->t_task_lba = transport_lba_64(cdb);
 883
 884                 if (sbc_check_dpofua(dev, cmd, cdb))
 885                         return TCM_INVALID_CDB_FIELD;
 886
 887                 ret = sbc_check_prot(dev, cmd, cdb, sectors, false);
 888                 if (ret)
 889                         return ret;
 890
 891                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 892                 cmd->execute_cmd = sbc_execute_rw;
 893                 break;
 894         case WRITE_6:
 895                 sectors = transport_get_sectors_6(cdb);
 896                 cmd->t_task_lba = transport_lba_21(cdb);
 897                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 898                 cmd->execute_cmd = sbc_execute_rw;
 899                 break;
 900         case WRITE_10:
 901         case WRITE_VERIFY:
 902                 sectors = transport_get_sectors_10(cdb);
 903                 cmd->t_task_lba = transport_lba_32(cdb);
 904
 905                 if (sbc_check_dpofua(dev, cmd, cdb))
 906                         return TCM_INVALID_CDB_FIELD;
 907
 908                 ret = sbc_check_prot(dev, cmd, cdb, sectors, true);
 909                 if (ret)
 910                         return ret;
 911
 912                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 913                 cmd->execute_cmd = sbc_execute_rw;
 914                 break;
 915         case WRITE_12:
 916                 sectors = transport_get_sectors_12(cdb);
 917                 cmd->t_task_lba = transport_lba_32(cdb);
 918
 919                 if (sbc_check_dpofua(dev, cmd, cdb))
 920                         return TCM_INVALID_CDB_FIELD;
 921
 922                 ret = sbc_check_prot(dev, cmd, cdb, sectors, true);
 923                 if (ret)
 924                         return ret;
 925
 926                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 927                 cmd->execute_cmd = sbc_execute_rw;
 928                 break;
 929         case WRITE_16:
 930         case WRITE_VERIFY_16:
 931                 sectors = transport_get_sectors_16(cdb);
 932                 cmd->t_task_lba = transport_lba_64(cdb);
 933
 934                 if (sbc_check_dpofua(dev, cmd, cdb))
 935                         return TCM_INVALID_CDB_FIELD;
 936
 937                 ret = sbc_check_prot(dev, cmd, cdb, sectors, true);
 938                 if (ret)
 939                         return ret;
 940
 941                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 942                 cmd->execute_cmd = sbc_execute_rw;
 943                 break;
 944         case XDWRITEREAD_10:
 945                 if (cmd->data_direction != DMA_TO_DEVICE ||
 946                     !(cmd->se_cmd_flags & SCF_BIDI))
 947                         return TCM_INVALID_CDB_FIELD;
 948                 sectors = transport_get_sectors_10(cdb);
 949
 950                 if (sbc_check_dpofua(dev, cmd, cdb))
 951                         return TCM_INVALID_CDB_FIELD;
 952
 953                 cmd->t_task_lba = transport_lba_32(cdb);
 954                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 955
 956                 /*
 957                  * Setup BIDI XOR callback to be run after I/O completion.
 958                  */
 959                 cmd->execute_cmd = sbc_execute_rw;
 960                 cmd->transport_complete_callback = &xdreadwrite_callback;
 961                 break;
 962         case VARIABLE_LENGTH_CMD:
 963         {
 964                 u16 service_action = get_unaligned_be16(&cdb[8]);
 965                 switch (service_action) {
 966                 case XDWRITEREAD_32:
 967                         sectors = transport_get_sectors_32(cdb);
 968
 969                         if (sbc_check_dpofua(dev, cmd, cdb))
 970                                 return TCM_INVALID_CDB_FIELD;
 971                         /*
 972                          * Use WRITE_32 and READ_32 opcodes for the emulated
 973                          * XDWRITE_READ_32 logic.
 974                          */
 975                         cmd->t_task_lba = transport_lba_64_ext(cdb);
 976                         cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 977
 978                         /*
 979                          * Setup BIDI XOR callback to be run during after I/O
 980                          * completion.
 981                          */
 982                         cmd->execute_cmd = sbc_execute_rw;
 983                         cmd->transport_complete_callback = &xdreadwrite_callback;
 984                         break;
 985                 case WRITE_SAME_32:
 986                         sectors = transport_get_sectors_32(cdb);
 987                         if (!sectors) {
 988                                 pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not"
 989                                        " supported\n");
 990                                 return TCM_INVALID_CDB_FIELD;
 991                         }
 992
 993                         size = sbc_get_size(cmd, 1);
 994                         cmd->t_task_lba = get_unaligned_be64(&cdb[12]);
 995
 996                         ret = sbc_setup_write_same(cmd, &cdb[10], ops);
 997                         if (ret)
 998                                 return ret;
 999                         break;
1000                 default:
1001                         pr_err("VARIABLE_LENGTH_CMD service action"
1002                                 " 0x%04x not supported\n", service_action);
1003                         return TCM_UNSUPPORTED_SCSI_OPCODE;
1004                 }
1005                 break;
1006         }
1007         case COMPARE_AND_WRITE:
1008                 sectors = cdb[13];
1009                 /*
1010                  * Currently enforce COMPARE_AND_WRITE for a single sector
1011                  */
1012                 if (sectors > 1) {
1013                         pr_err("COMPARE_AND_WRITE contains NoLB: %u greater"
1014                                " than 1\n", sectors);
1015                         return TCM_INVALID_CDB_FIELD;
1016                 }
1017                 if (sbc_check_dpofua(dev, cmd, cdb))
1018                         return TCM_INVALID_CDB_FIELD;
1019
1020                 /*
1021                  * Double size because we have two buffers, note that
1022                  * zero is not an error..
1023                  */
1024                 size = 2 * sbc_get_size(cmd, sectors);
1025                 cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
1026                 cmd->t_task_nolb = sectors;
1027                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB | SCF_COMPARE_AND_WRITE;
1028                 cmd->execute_cmd = sbc_compare_and_write;
1029                 cmd->transport_complete_callback = compare_and_write_callback;
1030                 break;
1031         case READ_CAPACITY:
1032                 size = READ_CAP_LEN;
1033                 cmd->execute_cmd = sbc_emulate_readcapacity;
1034                 break;
1035         case SERVICE_ACTION_IN_16:
1036                 switch (cmd->t_task_cdb[1] & 0x1f) {
1037                 case SAI_READ_CAPACITY_16:
1038                         cmd->execute_cmd = sbc_emulate_readcapacity_16;
1039                         break;
1040                 case SAI_REPORT_REFERRALS:
1041                         cmd->execute_cmd = target_emulate_report_referrals;
1042                         break;
1043                 default:
1044                         pr_err("Unsupported SA: 0x%02x\n",
1045                                 cmd->t_task_cdb[1] & 0x1f);
1046                         return TCM_INVALID_CDB_FIELD;
1047                 }
1048                 size = (cdb[10] << 24) | (cdb[11] << 16) |
1049                        (cdb[12] << 8) | cdb[13];
1050                 break;
1051         case SYNCHRONIZE_CACHE:
1052         case SYNCHRONIZE_CACHE_16:
1053                 if (cdb[0] == SYNCHRONIZE_CACHE) {
1054                         sectors = transport_get_sectors_10(cdb);
1055                         cmd->t_task_lba = transport_lba_32(cdb);
1056                 } else {
1057                         sectors = transport_get_sectors_16(cdb);
1058                         cmd->t_task_lba = transport_lba_64(cdb);
1059                 }
1060                 if (ops->execute_sync_cache) {
1061                         cmd->execute_cmd = ops->execute_sync_cache;
1062                         goto check_lba;
1063                 }
1064                 size = 0;
1065                 cmd->execute_cmd = sbc_emulate_noop;
1066                 break;
1067         case UNMAP:
1068                 if (!ops->execute_unmap)
1069                         return TCM_UNSUPPORTED_SCSI_OPCODE;
1070
1071                 if (!dev->dev_attrib.emulate_tpu) {
1072                         pr_err("Got UNMAP, but backend device has"
1073                                " emulate_tpu disabled\n");
1074                         return TCM_UNSUPPORTED_SCSI_OPCODE;
1075                 }
1076                 size = get_unaligned_be16(&cdb[7]);
1077                 cmd->execute_cmd = sbc_execute_unmap;
1078                 break;
1079         case WRITE_SAME_16:
1080                 sectors = transport_get_sectors_16(cdb);
1081                 if (!sectors) {
1082                         pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
1083                         return TCM_INVALID_CDB_FIELD;
1084                 }
1085
1086                 size = sbc_get_size(cmd, 1);
1087                 cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
1088
1089                 ret = sbc_setup_write_same(cmd, &cdb[1], ops);
1090                 if (ret)
1091                         return ret;
1092                 break;
1093         case WRITE_SAME:
1094                 sectors = transport_get_sectors_10(cdb);
1095                 if (!sectors) {
1096                         pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
1097                         return TCM_INVALID_CDB_FIELD;
1098                 }
1099
1100                 size = sbc_get_size(cmd, 1);
1101                 cmd->t_task_lba = get_unaligned_be32(&cdb[2]);
1102
1103                 /*
1104                  * Follow sbcr26 with WRITE_SAME (10) and check for the existence
1105                  * of byte 1 bit 3 UNMAP instead of original reserved field
1106                  */
1107                 ret = sbc_setup_write_same(cmd, &cdb[1], ops);
1108                 if (ret)
1109                         return ret;
1110                 break;
1111         case VERIFY:
1112         case VERIFY_16:
1113                 size = 0;
1114                 if (cdb[0] == VERIFY) {
1115                         sectors = transport_get_sectors_10(cdb);
1116                         cmd->t_task_lba = transport_lba_32(cdb);
1117                 } else {
1118                         sectors = transport_get_sectors_16(cdb);
1119                         cmd->t_task_lba = transport_lba_64(cdb);
1120                 }
1121                 cmd->execute_cmd = sbc_emulate_noop;
1122                 goto check_lba;
1123         case REZERO_UNIT:
1124         case SEEK_6:
1125         case SEEK_10:
1126                 /*
1127                  * There are still clients out there which use these old SCSI-2
1128                  * commands. This mainly happens when running VMs with legacy
1129                  * guest systems, connected via SCSI command pass-through to
1130                  * iSCSI targets. Make them happy and return status GOOD.
1131                  */
1132                 size = 0;
1133                 cmd->execute_cmd = sbc_emulate_noop;
1134                 break;
1135         case START_STOP:
1136                 size = 0;
1137                 cmd->execute_cmd = sbc_emulate_startstop;
1138                 break;
1139         default:
1140                 ret = spc_parse_cdb(cmd, &size);
1141                 if (ret)
1142                         return ret;
1143         }
1144
1145         /* reject any command that we don't have a handler for */
1146         if (!cmd->execute_cmd)
1147                 return TCM_UNSUPPORTED_SCSI_OPCODE;
1148
1149         if (cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
1150                 unsigned long long end_lba;
1151 check_lba:
1152                 end_lba = dev->transport->get_blocks(dev) + 1;
1153                 if (((cmd->t_task_lba + sectors) < cmd->t_task_lba) ||
1154                     ((cmd->t_task_lba + sectors) > end_lba)) {
1155                         pr_err("cmd exceeds last lba %llu "
1156                                 "(lba %llu, sectors %u)\n",
1157                                 end_lba, cmd->t_task_lba, sectors);
1158                         return TCM_ADDRESS_OUT_OF_RANGE;
1159                 }
1160
1161                 if (!(cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE))
1162                         size = sbc_get_size(cmd, sectors);
1163         }
1164
1165         return target_cmd_size_check(cmd, size);
1166 }
1167 EXPORT_SYMBOL(sbc_parse_cdb);
1168
1169 u32 sbc_get_device_type(struct se_device *dev)
1170 {
1171         return TYPE_DISK;
1172 }
1173 EXPORT_SYMBOL(sbc_get_device_type);
1174
1175 static sense_reason_t
1176 sbc_execute_unmap(struct se_cmd *cmd)
1177 {
1178         struct sbc_ops *ops = cmd->protocol_data;
1179         struct se_device *dev = cmd->se_dev;
1180         unsigned char *buf, *ptr = NULL;
1181         sector_t lba;
1182         int size;
1183         u32 range;
1184         sense_reason_t ret = 0;
1185         int dl, bd_dl;
1186
1187         /* We never set ANC_SUP */
1188         if (cmd->t_task_cdb[1])
1189                 return TCM_INVALID_CDB_FIELD;
1190
1191         if (cmd->data_length == 0) {
1192                 target_complete_cmd(cmd, SAM_STAT_GOOD);
1193                 return 0;
1194         }
1195
1196         if (cmd->data_length < 8) {
1197                 pr_warn("UNMAP parameter list length %u too small\n",
1198                         cmd->data_length);
1199                 return TCM_PARAMETER_LIST_LENGTH_ERROR;
1200         }
1201
1202         buf = transport_kmap_data_sg(cmd);
1203         if (!buf)
1204                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1205
1206         dl = get_unaligned_be16(&buf[0]);
1207         bd_dl = get_unaligned_be16(&buf[2]);
1208
1209         size = cmd->data_length - 8;
1210         if (bd_dl > size)
1211                 pr_warn("UNMAP parameter list length %u too small, ignoring bd_dl %u\n",
1212                         cmd->data_length, bd_dl);
1213         else
1214                 size = bd_dl;
1215
1216         if (size / 16 > dev->dev_attrib.max_unmap_block_desc_count) {
1217                 ret = TCM_INVALID_PARAMETER_LIST;
1218                 goto err;
1219         }
1220
1221         /* First UNMAP block descriptor starts at 8 byte offset */
1222         ptr = &buf[8];
1223         pr_debug("UNMAP: Sub: %s Using dl: %u bd_dl: %u size: %u"
1224                 " ptr: %p\n", dev->transport->name, dl, bd_dl, size, ptr);
1225
1226         while (size >= 16) {
1227                 lba = get_unaligned_be64(&ptr[0]);
1228                 range = get_unaligned_be32(&ptr[8]);
1229                 pr_debug("UNMAP: Using lba: %llu and range: %u\n",
1230                                  (unsigned long long)lba, range);
1231
1232                 if (range > dev->dev_attrib.max_unmap_lba_count) {
1233                         ret = TCM_INVALID_PARAMETER_LIST;
1234                         goto err;
1235                 }
1236
1237                 if (lba + range > dev->transport->get_blocks(dev) + 1) {
1238                         ret = TCM_ADDRESS_OUT_OF_RANGE;
1239                         goto err;
1240                 }
1241
1242                 ret = ops->execute_unmap(cmd, lba, range);
1243                 if (ret)
1244                         goto err;
1245
1246                 ptr += 16;
1247                 size -= 16;
1248         }
1249
1250 err:
1251         transport_kunmap_data_sg(cmd);
1252         if (!ret)
1253                 target_complete_cmd(cmd, GOOD);
1254         return ret;
1255 }
1256
1257 void
1258 sbc_dif_generate(struct se_cmd *cmd)
1259 {
1260         struct se_device *dev = cmd->se_dev;
1261         struct t10_pi_tuple *sdt;
1262         struct scatterlist *dsg = cmd->t_data_sg, *psg;
1263         sector_t sector = cmd->t_task_lba;
1264         void *daddr, *paddr;
1265         int i, j, offset = 0;
1266         unsigned int block_size = dev->dev_attrib.block_size;
1267
1268         for_each_sg(cmd->t_prot_sg, psg, cmd->t_prot_nents, i) {
1269                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1270                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1271
1272                 for (j = 0; j < psg->length;
1273                                 j += sizeof(*sdt)) {
1274                         __u16 crc;
1275                         unsigned int avail;
1276
1277                         if (offset >= dsg->length) {
1278                                 offset -= dsg->length;
1279                                 kunmap_atomic(daddr - dsg->offset);
1280                                 dsg = sg_next(dsg);
1281                                 if (!dsg) {
1282                                         kunmap_atomic(paddr - psg->offset);
1283                                         return;
1284                                 }
1285                                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1286                         }
1287
1288                         sdt = paddr + j;
1289                         avail = min(block_size, dsg->length - offset);
1290                         crc = crc_t10dif(daddr + offset, avail);
1291                         if (avail < block_size) {
1292                                 kunmap_atomic(daddr - dsg->offset);
1293                                 dsg = sg_next(dsg);
1294                                 if (!dsg) {
1295                                         kunmap_atomic(paddr - psg->offset);
1296                                         return;
1297                                 }
1298                                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1299                                 offset = block_size - avail;
1300                                 crc = crc_t10dif_update(crc, daddr, offset);
1301                         } else {
1302                                 offset += block_size;
1303                         }
1304
1305                         sdt->guard_tag = cpu_to_be16(crc);
1306                         if (cmd->prot_type == TARGET_DIF_TYPE1_PROT)
1307                                 sdt->ref_tag = cpu_to_be32(sector & 0xffffffff);
1308                         sdt->app_tag = 0;
1309
1310                         pr_debug("DIF %s INSERT sector: %llu guard_tag: 0x%04x"
1311                                  " app_tag: 0x%04x ref_tag: %u\n",
1312                                  (cmd->data_direction == DMA_TO_DEVICE) ?
1313                                  "WRITE" : "READ", (unsigned long long)sector,
1314                                  sdt->guard_tag, sdt->app_tag,
1315                                  be32_to_cpu(sdt->ref_tag));
1316
1317                         sector++;
1318                 }
1319
1320                 kunmap_atomic(daddr - dsg->offset);
1321                 kunmap_atomic(paddr - psg->offset);
1322         }
1323 }
1324
1325 static sense_reason_t
1326 sbc_dif_v1_verify(struct se_cmd *cmd, struct t10_pi_tuple *sdt,
1327                   __u16 crc, sector_t sector, unsigned int ei_lba)
1328 {
1329         __be16 csum;
1330
1331         if (!(cmd->prot_checks & TARGET_DIF_CHECK_GUARD))
1332                 goto check_ref;
1333
1334         csum = cpu_to_be16(crc);
1335
1336         if (sdt->guard_tag != csum) {
1337                 pr_err("DIFv1 checksum failed on sector %llu guard tag 0x%04x"
1338                         " csum 0x%04x\n", (unsigned long long)sector,
1339                         be16_to_cpu(sdt->guard_tag), be16_to_cpu(csum));
1340                 return TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED;
1341         }
1342
1343 check_ref:
1344         if (!(cmd->prot_checks & TARGET_DIF_CHECK_REFTAG))
1345                 return 0;
1346
1347         if (cmd->prot_type == TARGET_DIF_TYPE1_PROT &&
1348             be32_to_cpu(sdt->ref_tag) != (sector & 0xffffffff)) {
1349                 pr_err("DIFv1 Type 1 reference failed on sector: %llu tag: 0x%08x"
1350                        " sector MSB: 0x%08x\n", (unsigned long long)sector,
1351                        be32_to_cpu(sdt->ref_tag), (u32)(sector & 0xffffffff));
1352                 return TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;
1353         }
1354
1355         if (cmd->prot_type == TARGET_DIF_TYPE2_PROT &&
1356             be32_to_cpu(sdt->ref_tag) != ei_lba) {
1357                 pr_err("DIFv1 Type 2 reference failed on sector: %llu tag: 0x%08x"
1358                        " ei_lba: 0x%08x\n", (unsigned long long)sector,
1359                         be32_to_cpu(sdt->ref_tag), ei_lba);
1360                 return TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;
1361         }
1362
1363         return 0;
1364 }
1365
1366 void sbc_dif_copy_prot(struct se_cmd *cmd, unsigned int sectors, bool read,
1367                        struct scatterlist *sg, int sg_off)
1368 {
1369         struct se_device *dev = cmd->se_dev;
1370         struct scatterlist *psg;
1371         void *paddr, *addr;
1372         unsigned int i, len, left;
1373         unsigned int offset = sg_off;
1374
1375         if (!sg)
1376                 return;
1377
1378         left = sectors * dev->prot_length;
1379
1380         for_each_sg(cmd->t_prot_sg, psg, cmd->t_prot_nents, i) {
1381                 unsigned int psg_len, copied = 0;
1382
1383                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1384                 psg_len = min(left, psg->length);
1385                 while (psg_len) {
1386                         len = min(psg_len, sg->length - offset);
1387                         addr = kmap_atomic(sg_page(sg)) + sg->offset + offset;
1388
1389                         if (read)
1390                                 memcpy(paddr + copied, addr, len);
1391                         else
1392                                 memcpy(addr, paddr + copied, len);
1393
1394                         left -= len;
1395                         offset += len;
1396                         copied += len;
1397                         psg_len -= len;
1398
1399                         kunmap_atomic(addr - sg->offset - offset);
1400
1401                         if (offset >= sg->length) {
1402                                 sg = sg_next(sg);
1403                                 offset = 0;
1404                         }
1405                 }
1406                 kunmap_atomic(paddr - psg->offset);
1407         }
1408 }
1409 EXPORT_SYMBOL(sbc_dif_copy_prot);
1410
1411 sense_reason_t
1412 sbc_dif_verify(struct se_cmd *cmd, sector_t start, unsigned int sectors,
1413                unsigned int ei_lba, struct scatterlist *psg, int psg_off)
1414 {
1415         struct se_device *dev = cmd->se_dev;
1416         struct t10_pi_tuple *sdt;
1417         struct scatterlist *dsg = cmd->t_data_sg;
1418         sector_t sector = start;
1419         void *daddr, *paddr;
1420         int i;
1421         sense_reason_t rc;
1422         int dsg_off = 0;
1423         unsigned int block_size = dev->dev_attrib.block_size;
1424
1425         for (; psg && sector < start + sectors; psg = sg_next(psg)) {
1426                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1427                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1428
1429                 for (i = psg_off; i < psg->length &&
1430                                 sector < start + sectors;
1431                                 i += sizeof(*sdt)) {
1432                         __u16 crc;
1433                         unsigned int avail;
1434
1435                         if (dsg_off >= dsg->length) {
1436                                 dsg_off -= dsg->length;
1437                                 kunmap_atomic(daddr - dsg->offset);
1438                                 dsg = sg_next(dsg);
1439                                 if (!dsg) {
1440                                         kunmap_atomic(paddr - psg->offset);
1441                                         return 0;
1442                                 }
1443                                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1444                         }
1445
1446                         sdt = paddr + i;
1447
1448                         pr_debug("DIF READ sector: %llu guard_tag: 0x%04x"
1449                                  " app_tag: 0x%04x ref_tag: %u\n",
1450                                  (unsigned long long)sector, sdt->guard_tag,
1451                                  sdt->app_tag, be32_to_cpu(sdt->ref_tag));
1452
1453                         if (sdt->app_tag == cpu_to_be16(0xffff)) {
1454                                 dsg_off += block_size;
1455                                 goto next;
1456                         }
1457
1458                         avail = min(block_size, dsg->length - dsg_off);
1459                         crc = crc_t10dif(daddr + dsg_off, avail);
1460                         if (avail < block_size) {
1461                                 kunmap_atomic(daddr - dsg->offset);
1462                                 dsg = sg_next(dsg);
1463                                 if (!dsg) {
1464                                         kunmap_atomic(paddr - psg->offset);
1465                                         return 0;
1466                                 }
1467                                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1468                                 dsg_off = block_size - avail;
1469                                 crc = crc_t10dif_update(crc, daddr, dsg_off);
1470                         } else {
1471                                 dsg_off += block_size;
1472                         }
1473
1474                         rc = sbc_dif_v1_verify(cmd, sdt, crc, sector, ei_lba);
1475                         if (rc) {
1476                                 kunmap_atomic(daddr - dsg->offset);
1477                                 kunmap_atomic(paddr - psg->offset);
1478                                 cmd->bad_sector = sector;
1479                                 return rc;
1480                         }
1481 next:
1482                         sector++;
1483                         ei_lba++;
1484                 }
1485
1486                 psg_off = 0;
1487                 kunmap_atomic(daddr - dsg->offset);
1488                 kunmap_atomic(paddr - psg->offset);
1489         }
1490
1491         return 0;
1492 }
1493 EXPORT_SYMBOL(sbc_dif_verify);