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
 455         /*
 456          * Only set SCF_COMPARE_AND_WRITE_POST to force a response fall-through
 457          * within target_complete_ok_work() if the command was successfully
 458          * sent to the backend driver.
 459          */
 460         spin_lock_irq(&cmd->t_state_lock);
 461         if ((cmd->transport_state & CMD_T_SENT) && !cmd->scsi_status) {
 462                 cmd->se_cmd_flags |= SCF_COMPARE_AND_WRITE_POST;
 463                 *post_ret = 1;
 464         }
 465         spin_unlock_irq(&cmd->t_state_lock);
 466
 467         /*
 468          * Unlock ->caw_sem originally obtained during sbc_compare_and_write()
 469          * before the original READ I/O submission.
 470          */
 471         up(&dev->caw_sem);
 472
 473         return TCM_NO_SENSE;
 474 }
 475
 476 static sense_reason_t compare_and_write_callback(struct se_cmd *cmd, bool success,
 477                                                  int *post_ret)
 478 {
 479         struct se_device *dev = cmd->se_dev;
 480         struct scatterlist *write_sg = NULL, *sg;
 481         unsigned char *buf = NULL, *addr;
 482         struct sg_mapping_iter m;
 483         unsigned int offset = 0, len;
 484         unsigned int nlbas = cmd->t_task_nolb;
 485         unsigned int block_size = dev->dev_attrib.block_size;
 486         unsigned int compare_len = (nlbas * block_size);
 487         sense_reason_t ret = TCM_NO_SENSE;
 488         int rc, i;
 489
 490         /*
 491          * Handle early failure in transport_generic_request_failure(),
 492          * which will not have taken ->caw_sem yet..
 493          */
 494         if (!success && (!cmd->t_data_sg || !cmd->t_bidi_data_sg))
 495                 return TCM_NO_SENSE;
 496         /*
 497          * Handle special case for zero-length COMPARE_AND_WRITE
 498          */
 499         if (!cmd->data_length)
 500                 goto out;
 501         /*
 502          * Immediately exit + release dev->caw_sem if command has already
 503          * been failed with a non-zero SCSI status.
 504          */
 505         if (cmd->scsi_status) {
 506                 pr_err("compare_and_write_callback: non zero scsi_status:"
 507                         " 0x%02x\n", cmd->scsi_status);
 508                 goto out;
 509         }
 510
 511         buf = kzalloc(cmd->data_length, GFP_KERNEL);
 512         if (!buf) {
 513                 pr_err("Unable to allocate compare_and_write buf\n");
 514                 ret = TCM_OUT_OF_RESOURCES;
 515                 goto out;
 516         }
 517
 518         write_sg = kmalloc(sizeof(struct scatterlist) * cmd->t_data_nents,
 519                            GFP_KERNEL);
 520         if (!write_sg) {
 521                 pr_err("Unable to allocate compare_and_write sg\n");
 522                 ret = TCM_OUT_OF_RESOURCES;
 523                 goto out;
 524         }
 525         sg_init_table(write_sg, cmd->t_data_nents);
 526         /*
 527          * Setup verify and write data payloads from total NumberLBAs.
 528          */
 529         rc = sg_copy_to_buffer(cmd->t_data_sg, cmd->t_data_nents, buf,
 530                                cmd->data_length);
 531         if (!rc) {
 532                 pr_err("sg_copy_to_buffer() failed for compare_and_write\n");
 533                 ret = TCM_OUT_OF_RESOURCES;
 534                 goto out;
 535         }
 536         /*
 537          * Compare against SCSI READ payload against verify payload
 538          */
 539         for_each_sg(cmd->t_bidi_data_sg, sg, cmd->t_bidi_data_nents, i) {
 540                 addr = (unsigned char *)kmap_atomic(sg_page(sg));
 541                 if (!addr) {
 542                         ret = TCM_OUT_OF_RESOURCES;
 543                         goto out;
 544                 }
 545
 546                 len = min(sg->length, compare_len);
 547
 548                 if (memcmp(addr, buf + offset, len)) {
 549                         pr_warn("Detected MISCOMPARE for addr: %p buf: %p\n",
 550                                 addr, buf + offset);
 551                         kunmap_atomic(addr);
 552                         goto miscompare;
 553                 }
 554                 kunmap_atomic(addr);
 555
 556                 offset += len;
 557                 compare_len -= len;
 558                 if (!compare_len)
 559                         break;
 560         }
 561
 562         i = 0;
 563         len = cmd->t_task_nolb * block_size;
 564         sg_miter_start(&m, cmd->t_data_sg, cmd->t_data_nents, SG_MITER_TO_SG);
 565         /*
 566          * Currently assumes NoLB=1 and SGLs are PAGE_SIZE..
 567          */
 568         while (len) {
 569                 sg_miter_next(&m);
 570
 571                 if (block_size < PAGE_SIZE) {
 572                         sg_set_page(&write_sg[i], m.page, block_size,
 573                                     m.piter.sg->offset + block_size);
 574                 } else {
 575                         sg_miter_next(&m);
 576                         sg_set_page(&write_sg[i], m.page, block_size,
 577                                     m.piter.sg->offset);
 578                 }
 579                 len -= block_size;
 580                 i++;
 581         }
 582         sg_miter_stop(&m);
 583         /*
 584          * Save the original SGL + nents values before updating to new
 585          * assignments, to be released in transport_free_pages() ->
 586          * transport_reset_sgl_orig()
 587          */
 588         cmd->t_data_sg_orig = cmd->t_data_sg;
 589         cmd->t_data_sg = write_sg;
 590         cmd->t_data_nents_orig = cmd->t_data_nents;
 591         cmd->t_data_nents = 1;
 592
 593         cmd->sam_task_attr = TCM_HEAD_TAG;
 594         cmd->transport_complete_callback = compare_and_write_post;
 595         /*
 596          * Now reset ->execute_cmd() to the normal sbc_execute_rw() handler
 597          * for submitting the adjusted SGL to write instance user-data.
 598          */
 599         cmd->execute_cmd = sbc_execute_rw;
 600
 601         spin_lock_irq(&cmd->t_state_lock);
 602         cmd->t_state = TRANSPORT_PROCESSING;
 603         cmd->transport_state |= CMD_T_ACTIVE|CMD_T_BUSY|CMD_T_SENT;
 604         spin_unlock_irq(&cmd->t_state_lock);
 605
 606         __target_execute_cmd(cmd, false);
 607
 608         kfree(buf);
 609         return ret;
 610
 611 miscompare:
 612         pr_warn("Target/%s: Send MISCOMPARE check condition and sense\n",
 613                 dev->transport->name);
 614         ret = TCM_MISCOMPARE_VERIFY;
 615 out:
 616         /*
 617          * In the MISCOMPARE or failure case, unlock ->caw_sem obtained in
 618          * sbc_compare_and_write() before the original READ I/O submission.
 619          */
 620         up(&dev->caw_sem);
 621         kfree(write_sg);
 622         kfree(buf);
 623         return ret;
 624 }
 625
 626 static sense_reason_t
 627 sbc_compare_and_write(struct se_cmd *cmd)
 628 {
 629         struct sbc_ops *ops = cmd->protocol_data;
 630         struct se_device *dev = cmd->se_dev;
 631         sense_reason_t ret;
 632         int rc;
 633         /*
 634          * Submit the READ first for COMPARE_AND_WRITE to perform the
 635          * comparision using SGLs at cmd->t_bidi_data_sg..
 636          */
 637         rc = down_interruptible(&dev->caw_sem);
 638         if (rc != 0) {
 639                 cmd->transport_complete_callback = NULL;
 640                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 641         }
 642         /*
 643          * Reset cmd->data_length to individual block_size in order to not
 644          * confuse backend drivers that depend on this value matching the
 645          * size of the I/O being submitted.
 646          */
 647         cmd->data_length = cmd->t_task_nolb * dev->dev_attrib.block_size;
 648
 649         ret = ops->execute_rw(cmd, cmd->t_bidi_data_sg, cmd->t_bidi_data_nents,
 650                               DMA_FROM_DEVICE);
 651         if (ret) {
 652                 cmd->transport_complete_callback = NULL;
 653                 up(&dev->caw_sem);
 654                 return ret;
 655         }
 656         /*
 657          * Unlock of dev->caw_sem to occur in compare_and_write_callback()
 658          * upon MISCOMPARE, or in compare_and_write_done() upon completion
 659          * of WRITE instance user-data.
 660          */
 661         return TCM_NO_SENSE;
 662 }
 663
 664 static int
 665 sbc_set_prot_op_checks(u8 protect, bool fabric_prot, enum target_prot_type prot_type,
 666                        bool is_write, struct se_cmd *cmd)
 667 {
 668         if (is_write) {
 669                 cmd->prot_op = fabric_prot ? TARGET_PROT_DOUT_STRIP :
 670                                protect ? TARGET_PROT_DOUT_PASS :
 671                                TARGET_PROT_DOUT_INSERT;
 672                 switch (protect) {
 673                 case 0x0:
 674                 case 0x3:
 675                         cmd->prot_checks = 0;
 676                         break;
 677                 case 0x1:
 678                 case 0x5:
 679                         cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
 680                         if (prot_type == TARGET_DIF_TYPE1_PROT)
 681                                 cmd->prot_checks |= TARGET_DIF_CHECK_REFTAG;
 682                         break;
 683                 case 0x2:
 684                         if (prot_type == TARGET_DIF_TYPE1_PROT)
 685                                 cmd->prot_checks = TARGET_DIF_CHECK_REFTAG;
 686                         break;
 687                 case 0x4:
 688                         cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
 689                         break;
 690                 default:
 691                         pr_err("Unsupported protect field %d\n", protect);
 692                         return -EINVAL;
 693                 }
 694         } else {
 695                 cmd->prot_op = fabric_prot ? TARGET_PROT_DIN_INSERT :
 696                                protect ? TARGET_PROT_DIN_PASS :
 697                                TARGET_PROT_DIN_STRIP;
 698                 switch (protect) {
 699                 case 0x0:
 700                 case 0x1:
 701                 case 0x5:
 702                         cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
 703                         if (prot_type == TARGET_DIF_TYPE1_PROT)
 704                                 cmd->prot_checks |= TARGET_DIF_CHECK_REFTAG;
 705                         break;
 706                 case 0x2:
 707                         if (prot_type == TARGET_DIF_TYPE1_PROT)
 708                                 cmd->prot_checks = TARGET_DIF_CHECK_REFTAG;
 709                         break;
 710                 case 0x3:
 711                         cmd->prot_checks = 0;
 712                         break;
 713                 case 0x4:
 714                         cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
 715                         break;
 716                 default:
 717                         pr_err("Unsupported protect field %d\n", protect);
 718                         return -EINVAL;
 719                 }
 720         }
 721
 722         return 0;
 723 }
 724
 725 static sense_reason_t
 726 sbc_check_prot(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb,
 727                u32 sectors, bool is_write)
 728 {
 729         u8 protect = cdb[1] >> 5;
 730         int sp_ops = cmd->se_sess->sup_prot_ops;
 731         int pi_prot_type = dev->dev_attrib.pi_prot_type;
 732         bool fabric_prot = false;
 733
 734         if (!cmd->t_prot_sg || !cmd->t_prot_nents) {
 735                 if (unlikely(protect &&
 736                     !dev->dev_attrib.pi_prot_type && !cmd->se_sess->sess_prot_type)) {
 737                         pr_err("CDB contains protect bit, but device + fabric does"
 738                                " not advertise PROTECT=1 feature bit\n");
 739                         return TCM_INVALID_CDB_FIELD;
 740                 }
 741                 if (cmd->prot_pto)
 742                         return TCM_NO_SENSE;
 743         }
 744
 745         switch (dev->dev_attrib.pi_prot_type) {
 746         case TARGET_DIF_TYPE3_PROT:
 747                 cmd->reftag_seed = 0xffffffff;
 748                 break;
 749         case TARGET_DIF_TYPE2_PROT:
 750                 if (protect)
 751                         return TCM_INVALID_CDB_FIELD;
 752
 753                 cmd->reftag_seed = cmd->t_task_lba;
 754                 break;
 755         case TARGET_DIF_TYPE1_PROT:
 756                 cmd->reftag_seed = cmd->t_task_lba;
 757                 break;
 758         case TARGET_DIF_TYPE0_PROT:
 759                 /*
 760                  * See if the fabric supports T10-PI, and the session has been
 761                  * configured to allow export PROTECT=1 feature bit with backend
 762                  * devices that don't support T10-PI.
 763                  */
 764                 fabric_prot = is_write ?
 765                               !!(sp_ops & (TARGET_PROT_DOUT_PASS | TARGET_PROT_DOUT_STRIP)) :
 766                               !!(sp_ops & (TARGET_PROT_DIN_PASS | TARGET_PROT_DIN_INSERT));
 767
 768                 if (fabric_prot && cmd->se_sess->sess_prot_type) {
 769                         pi_prot_type = cmd->se_sess->sess_prot_type;
 770                         break;
 771                 }
 772                 if (!protect)
 773                         return TCM_NO_SENSE;
 774                 /* Fallthrough */
 775         default:
 776                 pr_err("Unable to determine pi_prot_type for CDB: 0x%02x "
 777                        "PROTECT: 0x%02x\n", cdb[0], protect);
 778                 return TCM_INVALID_CDB_FIELD;
 779         }
 780
 781         if (sbc_set_prot_op_checks(protect, fabric_prot, pi_prot_type, is_write, cmd))
 782                 return TCM_INVALID_CDB_FIELD;
 783
 784         cmd->prot_type = pi_prot_type;
 785         cmd->prot_length = dev->prot_length * sectors;
 786
 787         /**
 788          * In case protection information exists over the wire
 789          * we modify command data length to describe pure data.
 790          * The actual transfer length is data length + protection
 791          * length
 792          **/
 793         if (protect)
 794                 cmd->data_length = sectors * dev->dev_attrib.block_size;
 795
 796         pr_debug("%s: prot_type=%d, data_length=%d, prot_length=%d "
 797                  "prot_op=%d prot_checks=%d\n",
 798                  __func__, cmd->prot_type, cmd->data_length, cmd->prot_length,
 799                  cmd->prot_op, cmd->prot_checks);
 800
 801         return TCM_NO_SENSE;
 802 }
 803
 804 static int
 805 sbc_check_dpofua(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb)
 806 {
 807         if (cdb[1] & 0x10) {
 808                 /* see explanation in spc_emulate_modesense */
 809                 if (!target_check_fua(dev)) {
 810                         pr_err("Got CDB: 0x%02x with DPO bit set, but device"
 811                                " does not advertise support for DPO\n", cdb[0]);
 812                         return -EINVAL;
 813                 }
 814         }
 815         if (cdb[1] & 0x8) {
 816                 if (!target_check_fua(dev)) {
 817                         pr_err("Got CDB: 0x%02x with FUA bit set, but device"
 818                                " does not advertise support for FUA write\n",
 819                                cdb[0]);
 820                         return -EINVAL;
 821                 }
 822                 cmd->se_cmd_flags |= SCF_FUA;
 823         }
 824         return 0;
 825 }
 826
 827 sense_reason_t
 828 sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
 829 {
 830         struct se_device *dev = cmd->se_dev;
 831         unsigned char *cdb = cmd->t_task_cdb;
 832         unsigned int size;
 833         u32 sectors = 0;
 834         sense_reason_t ret;
 835
 836         cmd->protocol_data = ops;
 837
 838         switch (cdb[0]) {
 839         case READ_6:
 840                 sectors = transport_get_sectors_6(cdb);
 841                 cmd->t_task_lba = transport_lba_21(cdb);
 842                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 843                 cmd->execute_cmd = sbc_execute_rw;
 844                 break;
 845         case READ_10:
 846                 sectors = transport_get_sectors_10(cdb);
 847                 cmd->t_task_lba = transport_lba_32(cdb);
 848
 849                 if (sbc_check_dpofua(dev, cmd, cdb))
 850                         return TCM_INVALID_CDB_FIELD;
 851
 852                 ret = sbc_check_prot(dev, cmd, cdb, sectors, false);
 853                 if (ret)
 854                         return ret;
 855
 856                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 857                 cmd->execute_cmd = sbc_execute_rw;
 858                 break;
 859         case READ_12:
 860                 sectors = transport_get_sectors_12(cdb);
 861                 cmd->t_task_lba = transport_lba_32(cdb);
 862
 863                 if (sbc_check_dpofua(dev, cmd, cdb))
 864                         return TCM_INVALID_CDB_FIELD;
 865
 866                 ret = sbc_check_prot(dev, cmd, cdb, sectors, false);
 867                 if (ret)
 868                         return ret;
 869
 870                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 871                 cmd->execute_cmd = sbc_execute_rw;
 872                 break;
 873         case READ_16:
 874                 sectors = transport_get_sectors_16(cdb);
 875                 cmd->t_task_lba = transport_lba_64(cdb);
 876
 877                 if (sbc_check_dpofua(dev, cmd, cdb))
 878                         return TCM_INVALID_CDB_FIELD;
 879
 880                 ret = sbc_check_prot(dev, cmd, cdb, sectors, false);
 881                 if (ret)
 882                         return ret;
 883
 884                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 885                 cmd->execute_cmd = sbc_execute_rw;
 886                 break;
 887         case WRITE_6:
 888                 sectors = transport_get_sectors_6(cdb);
 889                 cmd->t_task_lba = transport_lba_21(cdb);
 890                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 891                 cmd->execute_cmd = sbc_execute_rw;
 892                 break;
 893         case WRITE_10:
 894         case WRITE_VERIFY:
 895                 sectors = transport_get_sectors_10(cdb);
 896                 cmd->t_task_lba = transport_lba_32(cdb);
 897
 898                 if (sbc_check_dpofua(dev, cmd, cdb))
 899                         return TCM_INVALID_CDB_FIELD;
 900
 901                 ret = sbc_check_prot(dev, cmd, cdb, sectors, true);
 902                 if (ret)
 903                         return ret;
 904
 905                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 906                 cmd->execute_cmd = sbc_execute_rw;
 907                 break;
 908         case WRITE_12:
 909                 sectors = transport_get_sectors_12(cdb);
 910                 cmd->t_task_lba = transport_lba_32(cdb);
 911
 912                 if (sbc_check_dpofua(dev, cmd, cdb))
 913                         return TCM_INVALID_CDB_FIELD;
 914
 915                 ret = sbc_check_prot(dev, cmd, cdb, sectors, true);
 916                 if (ret)
 917                         return ret;
 918
 919                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 920                 cmd->execute_cmd = sbc_execute_rw;
 921                 break;
 922         case WRITE_16:
 923                 sectors = transport_get_sectors_16(cdb);
 924                 cmd->t_task_lba = transport_lba_64(cdb);
 925
 926                 if (sbc_check_dpofua(dev, cmd, cdb))
 927                         return TCM_INVALID_CDB_FIELD;
 928
 929                 ret = sbc_check_prot(dev, cmd, cdb, sectors, true);
 930                 if (ret)
 931                         return ret;
 932
 933                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 934                 cmd->execute_cmd = sbc_execute_rw;
 935                 break;
 936         case XDWRITEREAD_10:
 937                 if (cmd->data_direction != DMA_TO_DEVICE ||
 938                     !(cmd->se_cmd_flags & SCF_BIDI))
 939                         return TCM_INVALID_CDB_FIELD;
 940                 sectors = transport_get_sectors_10(cdb);
 941
 942                 if (sbc_check_dpofua(dev, cmd, cdb))
 943                         return TCM_INVALID_CDB_FIELD;
 944
 945                 cmd->t_task_lba = transport_lba_32(cdb);
 946                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 947
 948                 /*
 949                  * Setup BIDI XOR callback to be run after I/O completion.
 950                  */
 951                 cmd->execute_cmd = sbc_execute_rw;
 952                 cmd->transport_complete_callback = &xdreadwrite_callback;
 953                 break;
 954         case VARIABLE_LENGTH_CMD:
 955         {
 956                 u16 service_action = get_unaligned_be16(&cdb[8]);
 957                 switch (service_action) {
 958                 case XDWRITEREAD_32:
 959                         sectors = transport_get_sectors_32(cdb);
 960
 961                         if (sbc_check_dpofua(dev, cmd, cdb))
 962                                 return TCM_INVALID_CDB_FIELD;
 963                         /*
 964                          * Use WRITE_32 and READ_32 opcodes for the emulated
 965                          * XDWRITE_READ_32 logic.
 966                          */
 967                         cmd->t_task_lba = transport_lba_64_ext(cdb);
 968                         cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 969
 970                         /*
 971                          * Setup BIDI XOR callback to be run during after I/O
 972                          * completion.
 973                          */
 974                         cmd->execute_cmd = sbc_execute_rw;
 975                         cmd->transport_complete_callback = &xdreadwrite_callback;
 976                         break;
 977                 case WRITE_SAME_32:
 978                         sectors = transport_get_sectors_32(cdb);
 979                         if (!sectors) {
 980                                 pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not"
 981                                        " supported\n");
 982                                 return TCM_INVALID_CDB_FIELD;
 983                         }
 984
 985                         size = sbc_get_size(cmd, 1);
 986                         cmd->t_task_lba = get_unaligned_be64(&cdb[12]);
 987
 988                         ret = sbc_setup_write_same(cmd, &cdb[10], ops);
 989                         if (ret)
 990                                 return ret;
 991                         break;
 992                 default:
 993                         pr_err("VARIABLE_LENGTH_CMD service action"
 994                                 " 0x%04x not supported\n", service_action);
 995                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 996                 }
 997                 break;
 998         }
 999         case COMPARE_AND_WRITE:
1000                 sectors = cdb[13];
1001                 /*
1002                  * Currently enforce COMPARE_AND_WRITE for a single sector
1003                  */
1004                 if (sectors > 1) {
1005                         pr_err("COMPARE_AND_WRITE contains NoLB: %u greater"
1006                                " than 1\n", sectors);
1007                         return TCM_INVALID_CDB_FIELD;
1008                 }
1009                 if (sbc_check_dpofua(dev, cmd, cdb))
1010                         return TCM_INVALID_CDB_FIELD;
1011
1012                 /*
1013                  * Double size because we have two buffers, note that
1014                  * zero is not an error..
1015                  */
1016                 size = 2 * sbc_get_size(cmd, sectors);
1017                 cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
1018                 cmd->t_task_nolb = sectors;
1019                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB | SCF_COMPARE_AND_WRITE;
1020                 cmd->execute_cmd = sbc_compare_and_write;
1021                 cmd->transport_complete_callback = compare_and_write_callback;
1022                 break;
1023         case READ_CAPACITY:
1024                 size = READ_CAP_LEN;
1025                 cmd->execute_cmd = sbc_emulate_readcapacity;
1026                 break;
1027         case SERVICE_ACTION_IN_16:
1028                 switch (cmd->t_task_cdb[1] & 0x1f) {
1029                 case SAI_READ_CAPACITY_16:
1030                         cmd->execute_cmd = sbc_emulate_readcapacity_16;
1031                         break;
1032                 case SAI_REPORT_REFERRALS:
1033                         cmd->execute_cmd = target_emulate_report_referrals;
1034                         break;
1035                 default:
1036                         pr_err("Unsupported SA: 0x%02x\n",
1037                                 cmd->t_task_cdb[1] & 0x1f);
1038                         return TCM_INVALID_CDB_FIELD;
1039                 }
1040                 size = (cdb[10] << 24) | (cdb[11] << 16) |
1041                        (cdb[12] << 8) | cdb[13];
1042                 break;
1043         case SYNCHRONIZE_CACHE:
1044         case SYNCHRONIZE_CACHE_16:
1045                 if (cdb[0] == SYNCHRONIZE_CACHE) {
1046                         sectors = transport_get_sectors_10(cdb);
1047                         cmd->t_task_lba = transport_lba_32(cdb);
1048                 } else {
1049                         sectors = transport_get_sectors_16(cdb);
1050                         cmd->t_task_lba = transport_lba_64(cdb);
1051                 }
1052                 if (ops->execute_sync_cache) {
1053                         cmd->execute_cmd = ops->execute_sync_cache;
1054                         goto check_lba;
1055                 }
1056                 size = 0;
1057                 cmd->execute_cmd = sbc_emulate_noop;
1058                 break;
1059         case UNMAP:
1060                 if (!ops->execute_unmap)
1061                         return TCM_UNSUPPORTED_SCSI_OPCODE;
1062
1063                 if (!dev->dev_attrib.emulate_tpu) {
1064                         pr_err("Got UNMAP, but backend device has"
1065                                " emulate_tpu disabled\n");
1066                         return TCM_UNSUPPORTED_SCSI_OPCODE;
1067                 }
1068                 size = get_unaligned_be16(&cdb[7]);
1069                 cmd->execute_cmd = sbc_execute_unmap;
1070                 break;
1071         case WRITE_SAME_16:
1072                 sectors = transport_get_sectors_16(cdb);
1073                 if (!sectors) {
1074                         pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
1075                         return TCM_INVALID_CDB_FIELD;
1076                 }
1077
1078                 size = sbc_get_size(cmd, 1);
1079                 cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
1080
1081                 ret = sbc_setup_write_same(cmd, &cdb[1], ops);
1082                 if (ret)
1083                         return ret;
1084                 break;
1085         case WRITE_SAME:
1086                 sectors = transport_get_sectors_10(cdb);
1087                 if (!sectors) {
1088                         pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
1089                         return TCM_INVALID_CDB_FIELD;
1090                 }
1091
1092                 size = sbc_get_size(cmd, 1);
1093                 cmd->t_task_lba = get_unaligned_be32(&cdb[2]);
1094
1095                 /*
1096                  * Follow sbcr26 with WRITE_SAME (10) and check for the existence
1097                  * of byte 1 bit 3 UNMAP instead of original reserved field
1098                  */
1099                 ret = sbc_setup_write_same(cmd, &cdb[1], ops);
1100                 if (ret)
1101                         return ret;
1102                 break;
1103         case VERIFY:
1104                 size = 0;
1105                 sectors = transport_get_sectors_10(cdb);
1106                 cmd->t_task_lba = transport_lba_32(cdb);
1107                 cmd->execute_cmd = sbc_emulate_noop;
1108                 goto check_lba;
1109         case REZERO_UNIT:
1110         case SEEK_6:
1111         case SEEK_10:
1112                 /*
1113                  * There are still clients out there which use these old SCSI-2
1114                  * commands. This mainly happens when running VMs with legacy
1115                  * guest systems, connected via SCSI command pass-through to
1116                  * iSCSI targets. Make them happy and return status GOOD.
1117                  */
1118                 size = 0;
1119                 cmd->execute_cmd = sbc_emulate_noop;
1120                 break;
1121         case START_STOP:
1122                 size = 0;
1123                 cmd->execute_cmd = sbc_emulate_startstop;
1124                 break;
1125         default:
1126                 ret = spc_parse_cdb(cmd, &size);
1127                 if (ret)
1128                         return ret;
1129         }
1130
1131         /* reject any command that we don't have a handler for */
1132         if (!cmd->execute_cmd)
1133                 return TCM_UNSUPPORTED_SCSI_OPCODE;
1134
1135         if (cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
1136                 unsigned long long end_lba;
1137 check_lba:
1138                 end_lba = dev->transport->get_blocks(dev) + 1;
1139                 if (((cmd->t_task_lba + sectors) < cmd->t_task_lba) ||
1140                     ((cmd->t_task_lba + sectors) > end_lba)) {
1141                         pr_err("cmd exceeds last lba %llu "
1142                                 "(lba %llu, sectors %u)\n",
1143                                 end_lba, cmd->t_task_lba, sectors);
1144                         return TCM_ADDRESS_OUT_OF_RANGE;
1145                 }
1146
1147                 if (!(cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE))
1148                         size = sbc_get_size(cmd, sectors);
1149         }
1150
1151         return target_cmd_size_check(cmd, size);
1152 }
1153 EXPORT_SYMBOL(sbc_parse_cdb);
1154
1155 u32 sbc_get_device_type(struct se_device *dev)
1156 {
1157         return TYPE_DISK;
1158 }
1159 EXPORT_SYMBOL(sbc_get_device_type);
1160
1161 static sense_reason_t
1162 sbc_execute_unmap(struct se_cmd *cmd)
1163 {
1164         struct sbc_ops *ops = cmd->protocol_data;
1165         struct se_device *dev = cmd->se_dev;
1166         unsigned char *buf, *ptr = NULL;
1167         sector_t lba;
1168         int size;
1169         u32 range;
1170         sense_reason_t ret = 0;
1171         int dl, bd_dl;
1172
1173         /* We never set ANC_SUP */
1174         if (cmd->t_task_cdb[1])
1175                 return TCM_INVALID_CDB_FIELD;
1176
1177         if (cmd->data_length == 0) {
1178                 target_complete_cmd(cmd, SAM_STAT_GOOD);
1179                 return 0;
1180         }
1181
1182         if (cmd->data_length < 8) {
1183                 pr_warn("UNMAP parameter list length %u too small\n",
1184                         cmd->data_length);
1185                 return TCM_PARAMETER_LIST_LENGTH_ERROR;
1186         }
1187
1188         buf = transport_kmap_data_sg(cmd);
1189         if (!buf)
1190                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1191
1192         dl = get_unaligned_be16(&buf[0]);
1193         bd_dl = get_unaligned_be16(&buf[2]);
1194
1195         size = cmd->data_length - 8;
1196         if (bd_dl > size)
1197                 pr_warn("UNMAP parameter list length %u too small, ignoring bd_dl %u\n",
1198                         cmd->data_length, bd_dl);
1199         else
1200                 size = bd_dl;
1201
1202         if (size / 16 > dev->dev_attrib.max_unmap_block_desc_count) {
1203                 ret = TCM_INVALID_PARAMETER_LIST;
1204                 goto err;
1205         }
1206
1207         /* First UNMAP block descriptor starts at 8 byte offset */
1208         ptr = &buf[8];
1209         pr_debug("UNMAP: Sub: %s Using dl: %u bd_dl: %u size: %u"
1210                 " ptr: %p\n", dev->transport->name, dl, bd_dl, size, ptr);
1211
1212         while (size >= 16) {
1213                 lba = get_unaligned_be64(&ptr[0]);
1214                 range = get_unaligned_be32(&ptr[8]);
1215                 pr_debug("UNMAP: Using lba: %llu and range: %u\n",
1216                                  (unsigned long long)lba, range);
1217
1218                 if (range > dev->dev_attrib.max_unmap_lba_count) {
1219                         ret = TCM_INVALID_PARAMETER_LIST;
1220                         goto err;
1221                 }
1222
1223                 if (lba + range > dev->transport->get_blocks(dev) + 1) {
1224                         ret = TCM_ADDRESS_OUT_OF_RANGE;
1225                         goto err;
1226                 }
1227
1228                 ret = ops->execute_unmap(cmd, lba, range);
1229                 if (ret)
1230                         goto err;
1231
1232                 ptr += 16;
1233                 size -= 16;
1234         }
1235
1236 err:
1237         transport_kunmap_data_sg(cmd);
1238         if (!ret)
1239                 target_complete_cmd(cmd, GOOD);
1240         return ret;
1241 }
1242
1243 void
1244 sbc_dif_generate(struct se_cmd *cmd)
1245 {
1246         struct se_device *dev = cmd->se_dev;
1247         struct t10_pi_tuple *sdt;
1248         struct scatterlist *dsg = cmd->t_data_sg, *psg;
1249         sector_t sector = cmd->t_task_lba;
1250         void *daddr, *paddr;
1251         int i, j, offset = 0;
1252         unsigned int block_size = dev->dev_attrib.block_size;
1253
1254         for_each_sg(cmd->t_prot_sg, psg, cmd->t_prot_nents, i) {
1255                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1256                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1257
1258                 for (j = 0; j < psg->length;
1259                                 j += sizeof(*sdt)) {
1260                         __u16 crc;
1261                         unsigned int avail;
1262
1263                         if (offset >= dsg->length) {
1264                                 offset -= dsg->length;
1265                                 kunmap_atomic(daddr - dsg->offset);
1266                                 dsg = sg_next(dsg);
1267                                 if (!dsg) {
1268                                         kunmap_atomic(paddr - psg->offset);
1269                                         return;
1270                                 }
1271                                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1272                         }
1273
1274                         sdt = paddr + j;
1275                         avail = min(block_size, dsg->length - offset);
1276                         crc = crc_t10dif(daddr + offset, avail);
1277                         if (avail < block_size) {
1278                                 kunmap_atomic(daddr - dsg->offset);
1279                                 dsg = sg_next(dsg);
1280                                 if (!dsg) {
1281                                         kunmap_atomic(paddr - psg->offset);
1282                                         return;
1283                                 }
1284                                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1285                                 offset = block_size - avail;
1286                                 crc = crc_t10dif_update(crc, daddr, offset);
1287                         } else {
1288                                 offset += block_size;
1289                         }
1290
1291                         sdt->guard_tag = cpu_to_be16(crc);
1292                         if (cmd->prot_type == TARGET_DIF_TYPE1_PROT)
1293                                 sdt->ref_tag = cpu_to_be32(sector & 0xffffffff);
1294                         sdt->app_tag = 0;
1295
1296                         pr_debug("DIF %s INSERT sector: %llu guard_tag: 0x%04x"
1297                                  " app_tag: 0x%04x ref_tag: %u\n",
1298                                  (cmd->data_direction == DMA_TO_DEVICE) ?
1299                                  "WRITE" : "READ", (unsigned long long)sector,
1300                                  sdt->guard_tag, sdt->app_tag,
1301                                  be32_to_cpu(sdt->ref_tag));
1302
1303                         sector++;
1304                 }
1305
1306                 kunmap_atomic(daddr - dsg->offset);
1307                 kunmap_atomic(paddr - psg->offset);
1308         }
1309 }
1310
1311 static sense_reason_t
1312 sbc_dif_v1_verify(struct se_cmd *cmd, struct t10_pi_tuple *sdt,
1313                   __u16 crc, sector_t sector, unsigned int ei_lba)
1314 {
1315         __be16 csum;
1316
1317         if (!(cmd->prot_checks & TARGET_DIF_CHECK_GUARD))
1318                 goto check_ref;
1319
1320         csum = cpu_to_be16(crc);
1321
1322         if (sdt->guard_tag != csum) {
1323                 pr_err("DIFv1 checksum failed on sector %llu guard tag 0x%04x"
1324                         " csum 0x%04x\n", (unsigned long long)sector,
1325                         be16_to_cpu(sdt->guard_tag), be16_to_cpu(csum));
1326                 return TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED;
1327         }
1328
1329 check_ref:
1330         if (!(cmd->prot_checks & TARGET_DIF_CHECK_REFTAG))
1331                 return 0;
1332
1333         if (cmd->prot_type == TARGET_DIF_TYPE1_PROT &&
1334             be32_to_cpu(sdt->ref_tag) != (sector & 0xffffffff)) {
1335                 pr_err("DIFv1 Type 1 reference failed on sector: %llu tag: 0x%08x"
1336                        " sector MSB: 0x%08x\n", (unsigned long long)sector,
1337                        be32_to_cpu(sdt->ref_tag), (u32)(sector & 0xffffffff));
1338                 return TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;
1339         }
1340
1341         if (cmd->prot_type == TARGET_DIF_TYPE2_PROT &&
1342             be32_to_cpu(sdt->ref_tag) != ei_lba) {
1343                 pr_err("DIFv1 Type 2 reference failed on sector: %llu tag: 0x%08x"
1344                        " ei_lba: 0x%08x\n", (unsigned long long)sector,
1345                         be32_to_cpu(sdt->ref_tag), ei_lba);
1346                 return TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;
1347         }
1348
1349         return 0;
1350 }
1351
1352 void sbc_dif_copy_prot(struct se_cmd *cmd, unsigned int sectors, bool read,
1353                        struct scatterlist *sg, int sg_off)
1354 {
1355         struct se_device *dev = cmd->se_dev;
1356         struct scatterlist *psg;
1357         void *paddr, *addr;
1358         unsigned int i, len, left;
1359         unsigned int offset = sg_off;
1360
1361         if (!sg)
1362                 return;
1363
1364         left = sectors * dev->prot_length;
1365
1366         for_each_sg(cmd->t_prot_sg, psg, cmd->t_prot_nents, i) {
1367                 unsigned int psg_len, copied = 0;
1368
1369                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1370                 psg_len = min(left, psg->length);
1371                 while (psg_len) {
1372                         len = min(psg_len, sg->length - offset);
1373                         addr = kmap_atomic(sg_page(sg)) + sg->offset + offset;
1374
1375                         if (read)
1376                                 memcpy(paddr + copied, addr, len);
1377                         else
1378                                 memcpy(addr, paddr + copied, len);
1379
1380                         left -= len;
1381                         offset += len;
1382                         copied += len;
1383                         psg_len -= len;
1384
1385                         kunmap_atomic(addr - sg->offset - offset);
1386
1387                         if (offset >= sg->length) {
1388                                 sg = sg_next(sg);
1389                                 offset = 0;
1390                         }
1391                 }
1392                 kunmap_atomic(paddr - psg->offset);
1393         }
1394 }
1395 EXPORT_SYMBOL(sbc_dif_copy_prot);
1396
1397 sense_reason_t
1398 sbc_dif_verify(struct se_cmd *cmd, sector_t start, unsigned int sectors,
1399                unsigned int ei_lba, struct scatterlist *psg, int psg_off)
1400 {
1401         struct se_device *dev = cmd->se_dev;
1402         struct t10_pi_tuple *sdt;
1403         struct scatterlist *dsg = cmd->t_data_sg;
1404         sector_t sector = start;
1405         void *daddr, *paddr;
1406         int i;
1407         sense_reason_t rc;
1408         int dsg_off = 0;
1409         unsigned int block_size = dev->dev_attrib.block_size;
1410
1411         for (; psg && sector < start + sectors; psg = sg_next(psg)) {
1412                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1413                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1414
1415                 for (i = psg_off; i < psg->length &&
1416                                 sector < start + sectors;
1417                                 i += sizeof(*sdt)) {
1418                         __u16 crc;
1419                         unsigned int avail;
1420
1421                         if (dsg_off >= dsg->length) {
1422                                 dsg_off -= dsg->length;
1423                                 kunmap_atomic(daddr - dsg->offset);
1424                                 dsg = sg_next(dsg);
1425                                 if (!dsg) {
1426                                         kunmap_atomic(paddr - psg->offset);
1427                                         return 0;
1428                                 }
1429                                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1430                         }
1431
1432                         sdt = paddr + i;
1433
1434                         pr_debug("DIF READ sector: %llu guard_tag: 0x%04x"
1435                                  " app_tag: 0x%04x ref_tag: %u\n",
1436                                  (unsigned long long)sector, sdt->guard_tag,
1437                                  sdt->app_tag, be32_to_cpu(sdt->ref_tag));
1438
1439                         if (sdt->app_tag == cpu_to_be16(0xffff)) {
1440                                 dsg_off += block_size;
1441                                 goto next;
1442                         }
1443
1444                         avail = min(block_size, dsg->length - dsg_off);
1445                         crc = crc_t10dif(daddr + dsg_off, avail);
1446                         if (avail < block_size) {
1447                                 kunmap_atomic(daddr - dsg->offset);
1448                                 dsg = sg_next(dsg);
1449                                 if (!dsg) {
1450                                         kunmap_atomic(paddr - psg->offset);
1451                                         return 0;
1452                                 }
1453                                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1454                                 dsg_off = block_size - avail;
1455                                 crc = crc_t10dif_update(crc, daddr, dsg_off);
1456                         } else {
1457                                 dsg_off += block_size;
1458                         }
1459
1460                         rc = sbc_dif_v1_verify(cmd, sdt, crc, sector, ei_lba);
1461                         if (rc) {
1462                                 kunmap_atomic(daddr - dsg->offset);
1463                                 kunmap_atomic(paddr - psg->offset);
1464                                 cmd->bad_sector = sector;
1465                                 return rc;
1466                         }
1467 next:
1468                         sector++;
1469                         ei_lba++;
1470                 }
1471
1472                 psg_off = 0;
1473                 kunmap_atomic(daddr - dsg->offset);
1474                 kunmap_atomic(paddr - psg->offset);
1475         }
1476
1477         return 0;
1478 }
1479 EXPORT_SYMBOL(sbc_dif_verify);