drivers/target/target_core_sbc.c

   1 /*
   2  * SCSI Block Commands (SBC) parsing and emulation.
   3  *
   4  * (c) Copyright 2002-2013 Datera, Inc.
   5  *
   6  * Nicholas A. Bellinger <nab@kernel.org>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  21  */
  22
  23 #include <linux/kernel.h>
  24 #include <linux/module.h>
  25 #include <linux/ratelimit.h>
  26 #include <linux/crc-t10dif.h>
  27 #include <asm/unaligned.h>
  28 #include <scsi/scsi.h>
  29 #include <scsi/scsi_tcq.h>
  30
  31 #include <target/target_core_base.h>
  32 #include <target/target_core_backend.h>
  33 #include <target/target_core_fabric.h>
  34
  35 #include "target_core_internal.h"
  36 #include "target_core_ua.h"
  37 #include "target_core_alua.h"
  38
  39 static sense_reason_t
  40 sbc_check_prot(struct se_device *, struct se_cmd *, unsigned char *, u32, bool);
  41
  42 static sense_reason_t
  43 sbc_emulate_readcapacity(struct se_cmd *cmd)
  44 {
  45         struct se_device *dev = cmd->se_dev;
  46         unsigned char *cdb = cmd->t_task_cdb;
  47         unsigned long long blocks_long = dev->transport->get_blocks(dev);
  48         unsigned char *rbuf;
  49         unsigned char buf[8];
  50         u32 blocks;
  51
  52         /*
  53          * SBC-2 says:
  54          *   If the PMI bit is set to zero and the LOGICAL BLOCK
  55          *   ADDRESS field is not set to zero, the device server shall
  56          *   terminate the command with CHECK CONDITION status with
  57          *   the sense key set to ILLEGAL REQUEST and the additional
  58          *   sense code set to INVALID FIELD IN CDB.
  59          *
  60          * In SBC-3, these fields are obsolete, but some SCSI
  61          * compliance tests actually check this, so we might as well
  62          * follow SBC-2.
  63          */
  64         if (!(cdb[8] & 1) && !!(cdb[2] | cdb[3] | cdb[4] | cdb[5]))
  65                 return TCM_INVALID_CDB_FIELD;
  66
  67         if (blocks_long >= 0x00000000ffffffff)
  68                 blocks = 0xffffffff;
  69         else
  70                 blocks = (u32)blocks_long;
  71
  72         buf[0] = (blocks >> 24) & 0xff;
  73         buf[1] = (blocks >> 16) & 0xff;
  74         buf[2] = (blocks >> 8) & 0xff;
  75         buf[3] = blocks & 0xff;
  76         buf[4] = (dev->dev_attrib.block_size >> 24) & 0xff;
  77         buf[5] = (dev->dev_attrib.block_size >> 16) & 0xff;
  78         buf[6] = (dev->dev_attrib.block_size >> 8) & 0xff;
  79         buf[7] = dev->dev_attrib.block_size & 0xff;
  80
  81         rbuf = transport_kmap_data_sg(cmd);
  82         if (rbuf) {
  83                 memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length));
  84                 transport_kunmap_data_sg(cmd);
  85         }
  86
  87         target_complete_cmd_with_length(cmd, GOOD, 8);
  88         return 0;
  89 }
  90
  91 static sense_reason_t
  92 sbc_emulate_readcapacity_16(struct se_cmd *cmd)
  93 {
  94         struct se_device *dev = cmd->se_dev;
  95         struct se_session *sess = cmd->se_sess;
  96         unsigned char *rbuf;
  97         unsigned char buf[32];
  98         unsigned long long blocks = dev->transport->get_blocks(dev);
  99
 100         memset(buf, 0, sizeof(buf));
 101         buf[0] = (blocks >> 56) & 0xff;
 102         buf[1] = (blocks >> 48) & 0xff;
 103         buf[2] = (blocks >> 40) & 0xff;
 104         buf[3] = (blocks >> 32) & 0xff;
 105         buf[4] = (blocks >> 24) & 0xff;
 106         buf[5] = (blocks >> 16) & 0xff;
 107         buf[6] = (blocks >> 8) & 0xff;
 108         buf[7] = blocks & 0xff;
 109         buf[8] = (dev->dev_attrib.block_size >> 24) & 0xff;
 110         buf[9] = (dev->dev_attrib.block_size >> 16) & 0xff;
 111         buf[10] = (dev->dev_attrib.block_size >> 8) & 0xff;
 112         buf[11] = dev->dev_attrib.block_size & 0xff;
 113         /*
 114          * Set P_TYPE and PROT_EN bits for DIF support
 115          */
 116         if (sess->sup_prot_ops & (TARGET_PROT_DIN_PASS | TARGET_PROT_DOUT_PASS)) {
 117                 if (dev->dev_attrib.pi_prot_type)
 118                         buf[12] = (dev->dev_attrib.pi_prot_type - 1) << 1 | 0x1;
 119         }
 120
 121         if (dev->transport->get_lbppbe)
 122                 buf[13] = dev->transport->get_lbppbe(dev) & 0x0f;
 123
 124         if (dev->transport->get_alignment_offset_lbas) {
 125                 u16 lalba = dev->transport->get_alignment_offset_lbas(dev);
 126                 buf[14] = (lalba >> 8) & 0x3f;
 127                 buf[15] = lalba & 0xff;
 128         }
 129
 130         /*
 131          * Set Thin Provisioning Enable bit following sbc3r22 in section
 132          * READ CAPACITY (16) byte 14 if emulate_tpu or emulate_tpws is enabled.
 133          */
 134         if (dev->dev_attrib.emulate_tpu || dev->dev_attrib.emulate_tpws)
 135                 buf[14] |= 0x80;
 136
 137         rbuf = transport_kmap_data_sg(cmd);
 138         if (rbuf) {
 139                 memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length));
 140                 transport_kunmap_data_sg(cmd);
 141         }
 142
 143         target_complete_cmd_with_length(cmd, GOOD, 32);
 144         return 0;
 145 }
 146
 147 sector_t sbc_get_write_same_sectors(struct se_cmd *cmd)
 148 {
 149         u32 num_blocks;
 150
 151         if (cmd->t_task_cdb[0] == WRITE_SAME)
 152                 num_blocks = get_unaligned_be16(&cmd->t_task_cdb[7]);
 153         else if (cmd->t_task_cdb[0] == WRITE_SAME_16)
 154                 num_blocks = get_unaligned_be32(&cmd->t_task_cdb[10]);
 155         else /* WRITE_SAME_32 via VARIABLE_LENGTH_CMD */
 156                 num_blocks = get_unaligned_be32(&cmd->t_task_cdb[28]);
 157
 158         /*
 159          * Use the explicit range when non zero is supplied, otherwise calculate
 160          * the remaining range based on ->get_blocks() - starting LBA.
 161          */
 162         if (num_blocks)
 163                 return num_blocks;
 164
 165         return cmd->se_dev->transport->get_blocks(cmd->se_dev) -
 166                 cmd->t_task_lba + 1;
 167 }
 168 EXPORT_SYMBOL(sbc_get_write_same_sectors);
 169
 170 static sense_reason_t
 171 sbc_emulate_noop(struct se_cmd *cmd)
 172 {
 173         target_complete_cmd(cmd, GOOD);
 174         return 0;
 175 }
 176
 177 static inline u32 sbc_get_size(struct se_cmd *cmd, u32 sectors)
 178 {
 179         return cmd->se_dev->dev_attrib.block_size * sectors;
 180 }
 181
 182 static inline u32 transport_get_sectors_6(unsigned char *cdb)
 183 {
 184         /*
 185          * Use 8-bit sector value.  SBC-3 says:
 186          *
 187          *   A TRANSFER LENGTH field set to zero specifies that 256
 188          *   logical blocks shall be written.  Any other value
 189          *   specifies the number of logical blocks that shall be
 190          *   written.
 191          */
 192         return cdb[4] ? : 256;
 193 }
 194
 195 static inline u32 transport_get_sectors_10(unsigned char *cdb)
 196 {
 197         return (u32)(cdb[7] << 8) + cdb[8];
 198 }
 199
 200 static inline u32 transport_get_sectors_12(unsigned char *cdb)
 201 {
 202         return (u32)(cdb[6] << 24) + (cdb[7] << 16) + (cdb[8] << 8) + cdb[9];
 203 }
 204
 205 static inline u32 transport_get_sectors_16(unsigned char *cdb)
 206 {
 207         return (u32)(cdb[10] << 24) + (cdb[11] << 16) +
 208                     (cdb[12] << 8) + cdb[13];
 209 }
 210
 211 /*
 212  * Used for VARIABLE_LENGTH_CDB WRITE_32 and READ_32 variants
 213  */
 214 static inline u32 transport_get_sectors_32(unsigned char *cdb)
 215 {
 216         return (u32)(cdb[28] << 24) + (cdb[29] << 16) +
 217                     (cdb[30] << 8) + cdb[31];
 218
 219 }
 220
 221 static inline u32 transport_lba_21(unsigned char *cdb)
 222 {
 223         return ((cdb[1] & 0x1f) << 16) | (cdb[2] << 8) | cdb[3];
 224 }
 225
 226 static inline u32 transport_lba_32(unsigned char *cdb)
 227 {
 228         return (cdb[2] << 24) | (cdb[3] << 16) | (cdb[4] << 8) | cdb[5];
 229 }
 230
 231 static inline unsigned long long transport_lba_64(unsigned char *cdb)
 232 {
 233         unsigned int __v1, __v2;
 234
 235         __v1 = (cdb[2] << 24) | (cdb[3] << 16) | (cdb[4] << 8) | cdb[5];
 236         __v2 = (cdb[6] << 24) | (cdb[7] << 16) | (cdb[8] << 8) | cdb[9];
 237
 238         return ((unsigned long long)__v2) | (unsigned long long)__v1 << 32;
 239 }
 240
 241 /*
 242  * For VARIABLE_LENGTH_CDB w/ 32 byte extended CDBs
 243  */
 244 static inline unsigned long long transport_lba_64_ext(unsigned char *cdb)
 245 {
 246         unsigned int __v1, __v2;
 247
 248         __v1 = (cdb[12] << 24) | (cdb[13] << 16) | (cdb[14] << 8) | cdb[15];
 249         __v2 = (cdb[16] << 24) | (cdb[17] << 16) | (cdb[18] << 8) | cdb[19];
 250
 251         return ((unsigned long long)__v2) | (unsigned long long)__v1 << 32;
 252 }
 253
 254 static sense_reason_t
 255 sbc_setup_write_same(struct se_cmd *cmd, unsigned char *flags, struct sbc_ops *ops)
 256 {
 257         struct se_device *dev = cmd->se_dev;
 258         sector_t end_lba = dev->transport->get_blocks(dev) + 1;
 259         unsigned int sectors = sbc_get_write_same_sectors(cmd);
 260         sense_reason_t ret;
 261
 262         if ((flags[0] & 0x04) || (flags[0] & 0x02)) {
 263                 pr_err("WRITE_SAME PBDATA and LBDATA"
 264                         " bits not supported for Block Discard"
 265                         " Emulation\n");
 266                 return TCM_UNSUPPORTED_SCSI_OPCODE;
 267         }
 268         if (sectors > cmd->se_dev->dev_attrib.max_write_same_len) {
 269                 pr_warn("WRITE_SAME sectors: %u exceeds max_write_same_len: %u\n",
 270                         sectors, cmd->se_dev->dev_attrib.max_write_same_len);
 271                 return TCM_INVALID_CDB_FIELD;
 272         }
 273         /*
 274          * Sanity check for LBA wrap and request past end of device.
 275          */
 276         if (((cmd->t_task_lba + sectors) < cmd->t_task_lba) ||
 277             ((cmd->t_task_lba + sectors) > end_lba)) {
 278                 pr_err("WRITE_SAME exceeds last lba %llu (lba %llu, sectors %u)\n",
 279                        (unsigned long long)end_lba, cmd->t_task_lba, sectors);
 280                 return TCM_ADDRESS_OUT_OF_RANGE;
 281         }
 282
 283         /* We always have ANC_SUP == 0 so setting ANCHOR is always an error */
 284         if (flags[0] & 0x10) {
 285                 pr_warn("WRITE SAME with ANCHOR not supported\n");
 286                 return TCM_INVALID_CDB_FIELD;
 287         }
 288         /*
 289          * Special case for WRITE_SAME w/ UNMAP=1 that ends up getting
 290          * translated into block discard requests within backend code.
 291          */
 292         if (flags[0] & 0x08) {
 293                 if (!ops->execute_write_same_unmap)
 294                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 295
 296                 if (!dev->dev_attrib.emulate_tpws) {
 297                         pr_err("Got WRITE_SAME w/ UNMAP=1, but backend device"
 298                                " has emulate_tpws disabled\n");
 299                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 300                 }
 301                 cmd->execute_cmd = ops->execute_write_same_unmap;
 302                 return 0;
 303         }
 304         if (!ops->execute_write_same)
 305                 return TCM_UNSUPPORTED_SCSI_OPCODE;
 306
 307         ret = sbc_check_prot(dev, cmd, &cmd->t_task_cdb[0], sectors, true);
 308         if (ret)
 309                 return ret;
 310
 311         cmd->execute_cmd = ops->execute_write_same;
 312         return 0;
 313 }
 314
 315 static sense_reason_t xdreadwrite_callback(struct se_cmd *cmd, bool success)
 316 {
 317         unsigned char *buf, *addr;
 318         struct scatterlist *sg;
 319         unsigned int offset;
 320         sense_reason_t ret = TCM_NO_SENSE;
 321         int i, count;
 322         /*
 323          * From sbc3r22.pdf section 5.48 XDWRITEREAD (10) command
 324          *
 325          * 1) read the specified logical block(s);
 326          * 2) transfer logical blocks from the data-out buffer;
 327          * 3) XOR the logical blocks transferred from the data-out buffer with
 328          *    the logical blocks read, storing the resulting XOR data in a buffer;
 329          * 4) if the DISABLE WRITE bit is set to zero, then write the logical
 330          *    blocks transferred from the data-out buffer; and
 331          * 5) transfer the resulting XOR data to the data-in buffer.
 332          */
 333         buf = kmalloc(cmd->data_length, GFP_KERNEL);
 334         if (!buf) {
 335                 pr_err("Unable to allocate xor_callback buf\n");
 336                 return TCM_OUT_OF_RESOURCES;
 337         }
 338         /*
 339          * Copy the scatterlist WRITE buffer located at cmd->t_data_sg
 340          * into the locally allocated *buf
 341          */
 342         sg_copy_to_buffer(cmd->t_data_sg,
 343                           cmd->t_data_nents,
 344                           buf,
 345                           cmd->data_length);
 346
 347         /*
 348          * Now perform the XOR against the BIDI read memory located at
 349          * cmd->t_mem_bidi_list
 350          */
 351
 352         offset = 0;
 353         for_each_sg(cmd->t_bidi_data_sg, sg, cmd->t_bidi_data_nents, count) {
 354                 addr = kmap_atomic(sg_page(sg));
 355                 if (!addr) {
 356                         ret = TCM_OUT_OF_RESOURCES;
 357                         goto out;
 358                 }
 359
 360                 for (i = 0; i < sg->length; i++)
 361                         *(addr + sg->offset + i) ^= *(buf + offset + i);
 362
 363                 offset += sg->length;
 364                 kunmap_atomic(addr);
 365         }
 366
 367 out:
 368         kfree(buf);
 369         return ret;
 370 }
 371
 372 static sense_reason_t
 373 sbc_execute_rw(struct se_cmd *cmd)
 374 {
 375         return cmd->execute_rw(cmd, cmd->t_data_sg, cmd->t_data_nents,
 376                                cmd->data_direction);
 377 }
 378
 379 static sense_reason_t compare_and_write_post(struct se_cmd *cmd, bool success)
 380 {
 381         struct se_device *dev = cmd->se_dev;
 382
 383         /*
 384          * Only set SCF_COMPARE_AND_WRITE_POST to force a response fall-through
 385          * within target_complete_ok_work() if the command was successfully
 386          * sent to the backend driver.
 387          */
 388         spin_lock_irq(&cmd->t_state_lock);
 389         if ((cmd->transport_state & CMD_T_SENT) && !cmd->scsi_status)
 390                 cmd->se_cmd_flags |= SCF_COMPARE_AND_WRITE_POST;
 391         spin_unlock_irq(&cmd->t_state_lock);
 392
 393         /*
 394          * Unlock ->caw_sem originally obtained during sbc_compare_and_write()
 395          * before the original READ I/O submission.
 396          */
 397         up(&dev->caw_sem);
 398
 399         return TCM_NO_SENSE;
 400 }
 401
 402 static sense_reason_t compare_and_write_callback(struct se_cmd *cmd, bool success)
 403 {
 404         struct se_device *dev = cmd->se_dev;
 405         struct scatterlist *write_sg = NULL, *sg;
 406         unsigned char *buf = NULL, *addr;
 407         struct sg_mapping_iter m;
 408         unsigned int offset = 0, len;
 409         unsigned int nlbas = cmd->t_task_nolb;
 410         unsigned int block_size = dev->dev_attrib.block_size;
 411         unsigned int compare_len = (nlbas * block_size);
 412         sense_reason_t ret = TCM_NO_SENSE;
 413         int rc, i;
 414
 415         /*
 416          * Handle early failure in transport_generic_request_failure(),
 417          * which will not have taken ->caw_sem yet..
 418          */
 419         if (!success && (!cmd->t_data_sg || !cmd->t_bidi_data_sg))
 420                 return TCM_NO_SENSE;
 421         /*
 422          * Handle special case for zero-length COMPARE_AND_WRITE
 423          */
 424         if (!cmd->data_length)
 425                 goto out;
 426         /*
 427          * Immediately exit + release dev->caw_sem if command has already
 428          * been failed with a non-zero SCSI status.
 429          */
 430         if (cmd->scsi_status) {
 431                 pr_err("compare_and_write_callback: non zero scsi_status:"
 432                         " 0x%02x\n", cmd->scsi_status);
 433                 goto out;
 434         }
 435
 436         buf = kzalloc(cmd->data_length, GFP_KERNEL);
 437         if (!buf) {
 438                 pr_err("Unable to allocate compare_and_write buf\n");
 439                 ret = TCM_OUT_OF_RESOURCES;
 440                 goto out;
 441         }
 442
 443         write_sg = kmalloc(sizeof(struct scatterlist) * cmd->t_data_nents,
 444                            GFP_KERNEL);
 445         if (!write_sg) {
 446                 pr_err("Unable to allocate compare_and_write sg\n");
 447                 ret = TCM_OUT_OF_RESOURCES;
 448                 goto out;
 449         }
 450         sg_init_table(write_sg, cmd->t_data_nents);
 451         /*
 452          * Setup verify and write data payloads from total NumberLBAs.
 453          */
 454         rc = sg_copy_to_buffer(cmd->t_data_sg, cmd->t_data_nents, buf,
 455                                cmd->data_length);
 456         if (!rc) {
 457                 pr_err("sg_copy_to_buffer() failed for compare_and_write\n");
 458                 ret = TCM_OUT_OF_RESOURCES;
 459                 goto out;
 460         }
 461         /*
 462          * Compare against SCSI READ payload against verify payload
 463          */
 464         for_each_sg(cmd->t_bidi_data_sg, sg, cmd->t_bidi_data_nents, i) {
 465                 addr = (unsigned char *)kmap_atomic(sg_page(sg));
 466                 if (!addr) {
 467                         ret = TCM_OUT_OF_RESOURCES;
 468                         goto out;
 469                 }
 470
 471                 len = min(sg->length, compare_len);
 472
 473                 if (memcmp(addr, buf + offset, len)) {
 474                         pr_warn("Detected MISCOMPARE for addr: %p buf: %p\n",
 475                                 addr, buf + offset);
 476                         kunmap_atomic(addr);
 477                         goto miscompare;
 478                 }
 479                 kunmap_atomic(addr);
 480
 481                 offset += len;
 482                 compare_len -= len;
 483                 if (!compare_len)
 484                         break;
 485         }
 486
 487         i = 0;
 488         len = cmd->t_task_nolb * block_size;
 489         sg_miter_start(&m, cmd->t_data_sg, cmd->t_data_nents, SG_MITER_TO_SG);
 490         /*
 491          * Currently assumes NoLB=1 and SGLs are PAGE_SIZE..
 492          */
 493         while (len) {
 494                 sg_miter_next(&m);
 495
 496                 if (block_size < PAGE_SIZE) {
 497                         sg_set_page(&write_sg[i], m.page, block_size,
 498                                     block_size);
 499                 } else {
 500                         sg_miter_next(&m);
 501                         sg_set_page(&write_sg[i], m.page, block_size,
 502                                     0);
 503                 }
 504                 len -= block_size;
 505                 i++;
 506         }
 507         sg_miter_stop(&m);
 508         /*
 509          * Save the original SGL + nents values before updating to new
 510          * assignments, to be released in transport_free_pages() ->
 511          * transport_reset_sgl_orig()
 512          */
 513         cmd->t_data_sg_orig = cmd->t_data_sg;
 514         cmd->t_data_sg = write_sg;
 515         cmd->t_data_nents_orig = cmd->t_data_nents;
 516         cmd->t_data_nents = 1;
 517
 518         cmd->sam_task_attr = TCM_HEAD_TAG;
 519         cmd->transport_complete_callback = compare_and_write_post;
 520         /*
 521          * Now reset ->execute_cmd() to the normal sbc_execute_rw() handler
 522          * for submitting the adjusted SGL to write instance user-data.
 523          */
 524         cmd->execute_cmd = sbc_execute_rw;
 525
 526         spin_lock_irq(&cmd->t_state_lock);
 527         cmd->t_state = TRANSPORT_PROCESSING;
 528         cmd->transport_state |= CMD_T_ACTIVE|CMD_T_BUSY|CMD_T_SENT;
 529         spin_unlock_irq(&cmd->t_state_lock);
 530
 531         __target_execute_cmd(cmd);
 532
 533         kfree(buf);
 534         return ret;
 535
 536 miscompare:
 537         pr_warn("Target/%s: Send MISCOMPARE check condition and sense\n",
 538                 dev->transport->name);
 539         ret = TCM_MISCOMPARE_VERIFY;
 540 out:
 541         /*
 542          * In the MISCOMPARE or failure case, unlock ->caw_sem obtained in
 543          * sbc_compare_and_write() before the original READ I/O submission.
 544          */
 545         up(&dev->caw_sem);
 546         kfree(write_sg);
 547         kfree(buf);
 548         return ret;
 549 }
 550
 551 static sense_reason_t
 552 sbc_compare_and_write(struct se_cmd *cmd)
 553 {
 554         struct se_device *dev = cmd->se_dev;
 555         sense_reason_t ret;
 556         int rc;
 557         /*
 558          * Submit the READ first for COMPARE_AND_WRITE to perform the
 559          * comparision using SGLs at cmd->t_bidi_data_sg..
 560          */
 561         rc = down_interruptible(&dev->caw_sem);
 562         if ((rc != 0) || signal_pending(current)) {
 563                 cmd->transport_complete_callback = NULL;
 564                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 565         }
 566         /*
 567          * Reset cmd->data_length to individual block_size in order to not
 568          * confuse backend drivers that depend on this value matching the
 569          * size of the I/O being submitted.
 570          */
 571         cmd->data_length = cmd->t_task_nolb * dev->dev_attrib.block_size;
 572
 573         ret = cmd->execute_rw(cmd, cmd->t_bidi_data_sg, cmd->t_bidi_data_nents,
 574                               DMA_FROM_DEVICE);
 575         if (ret) {
 576                 cmd->transport_complete_callback = NULL;
 577                 up(&dev->caw_sem);
 578                 return ret;
 579         }
 580         /*
 581          * Unlock of dev->caw_sem to occur in compare_and_write_callback()
 582          * upon MISCOMPARE, or in compare_and_write_done() upon completion
 583          * of WRITE instance user-data.
 584          */
 585         return TCM_NO_SENSE;
 586 }
 587
 588 static int
 589 sbc_set_prot_op_checks(u8 protect, enum target_prot_type prot_type,
 590                        bool is_write, struct se_cmd *cmd)
 591 {
 592         if (is_write) {
 593                 cmd->prot_op = protect ? TARGET_PROT_DOUT_PASS :
 594                                          TARGET_PROT_DOUT_INSERT;
 595                 switch (protect) {
 596                 case 0x0:
 597                 case 0x3:
 598                         cmd->prot_checks = 0;
 599                         break;
 600                 case 0x1:
 601                 case 0x5:
 602                         cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
 603                         if (prot_type == TARGET_DIF_TYPE1_PROT)
 604                                 cmd->prot_checks |= TARGET_DIF_CHECK_REFTAG;
 605                         break;
 606                 case 0x2:
 607                         if (prot_type == TARGET_DIF_TYPE1_PROT)
 608                                 cmd->prot_checks = TARGET_DIF_CHECK_REFTAG;
 609                         break;
 610                 case 0x4:
 611                         cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
 612                         break;
 613                 default:
 614                         pr_err("Unsupported protect field %d\n", protect);
 615                         return -EINVAL;
 616                 }
 617         } else {
 618                 cmd->prot_op = protect ? TARGET_PROT_DIN_PASS :
 619                                          TARGET_PROT_DIN_STRIP;
 620                 switch (protect) {
 621                 case 0x0:
 622                 case 0x1:
 623                 case 0x5:
 624                         cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
 625                         if (prot_type == TARGET_DIF_TYPE1_PROT)
 626                                 cmd->prot_checks |= TARGET_DIF_CHECK_REFTAG;
 627                         break;
 628                 case 0x2:
 629                         if (prot_type == TARGET_DIF_TYPE1_PROT)
 630                                 cmd->prot_checks = TARGET_DIF_CHECK_REFTAG;
 631                         break;
 632                 case 0x3:
 633                         cmd->prot_checks = 0;
 634                         break;
 635                 case 0x4:
 636                         cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
 637                         break;
 638                 default:
 639                         pr_err("Unsupported protect field %d\n", protect);
 640                         return -EINVAL;
 641                 }
 642         }
 643
 644         return 0;
 645 }
 646
 647 static sense_reason_t
 648 sbc_check_prot(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb,
 649                u32 sectors, bool is_write)
 650 {
 651         u8 protect = cdb[1] >> 5;
 652
 653         if (!cmd->t_prot_sg || !cmd->t_prot_nents) {
 654                 if (protect && !dev->dev_attrib.pi_prot_type) {
 655                         pr_err("CDB contains protect bit, but device does not"
 656                                " advertise PROTECT=1 feature bit\n");
 657                         return TCM_INVALID_CDB_FIELD;
 658                 }
 659                 if (cmd->prot_pto)
 660                         return TCM_NO_SENSE;
 661         }
 662
 663         switch (dev->dev_attrib.pi_prot_type) {
 664         case TARGET_DIF_TYPE3_PROT:
 665                 cmd->reftag_seed = 0xffffffff;
 666                 break;
 667         case TARGET_DIF_TYPE2_PROT:
 668                 if (protect)
 669                         return TCM_INVALID_CDB_FIELD;
 670
 671                 cmd->reftag_seed = cmd->t_task_lba;
 672                 break;
 673         case TARGET_DIF_TYPE1_PROT:
 674                 cmd->reftag_seed = cmd->t_task_lba;
 675                 break;
 676         case TARGET_DIF_TYPE0_PROT:
 677         default:
 678                 return TCM_NO_SENSE;
 679         }
 680
 681         if (sbc_set_prot_op_checks(protect, dev->dev_attrib.pi_prot_type,
 682                                    is_write, cmd))
 683                 return TCM_INVALID_CDB_FIELD;
 684
 685         cmd->prot_type = dev->dev_attrib.pi_prot_type;
 686         cmd->prot_length = dev->prot_length * sectors;
 687
 688         /**
 689          * In case protection information exists over the wire
 690          * we modify command data length to describe pure data.
 691          * The actual transfer length is data length + protection
 692          * length
 693          **/
 694         if (protect)
 695                 cmd->data_length = sectors * dev->dev_attrib.block_size;
 696
 697         pr_debug("%s: prot_type=%d, data_length=%d, prot_length=%d "
 698                  "prot_op=%d prot_checks=%d\n",
 699                  __func__, cmd->prot_type, cmd->data_length, cmd->prot_length,
 700                  cmd->prot_op, cmd->prot_checks);
 701
 702         return TCM_NO_SENSE;
 703 }
 704
 705 static int
 706 sbc_check_dpofua(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb)
 707 {
 708         if (cdb[1] & 0x10) {
 709                 if (!dev->dev_attrib.emulate_dpo) {
 710                         pr_err("Got CDB: 0x%02x with DPO bit set, but device"
 711                                " does not advertise support for DPO\n", cdb[0]);
 712                         return -EINVAL;
 713                 }
 714         }
 715         if (cdb[1] & 0x8) {
 716                 if (!dev->dev_attrib.emulate_fua_write || !se_dev_check_wce(dev)) {
 717                         pr_err("Got CDB: 0x%02x with FUA bit set, but device"
 718                                " does not advertise support for FUA write\n",
 719                                cdb[0]);
 720                         return -EINVAL;
 721                 }
 722                 cmd->se_cmd_flags |= SCF_FUA;
 723         }
 724         return 0;
 725 }
 726
 727 sense_reason_t
 728 sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
 729 {
 730         struct se_device *dev = cmd->se_dev;
 731         unsigned char *cdb = cmd->t_task_cdb;
 732         unsigned int size;
 733         u32 sectors = 0;
 734         sense_reason_t ret;
 735
 736         switch (cdb[0]) {
 737         case READ_6:
 738                 sectors = transport_get_sectors_6(cdb);
 739                 cmd->t_task_lba = transport_lba_21(cdb);
 740                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 741                 cmd->execute_rw = ops->execute_rw;
 742                 cmd->execute_cmd = sbc_execute_rw;
 743                 break;
 744         case READ_10:
 745                 sectors = transport_get_sectors_10(cdb);
 746                 cmd->t_task_lba = transport_lba_32(cdb);
 747
 748                 if (sbc_check_dpofua(dev, cmd, cdb))
 749                         return TCM_INVALID_CDB_FIELD;
 750
 751                 ret = sbc_check_prot(dev, cmd, cdb, sectors, false);
 752                 if (ret)
 753                         return ret;
 754
 755                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 756                 cmd->execute_rw = ops->execute_rw;
 757                 cmd->execute_cmd = sbc_execute_rw;
 758                 break;
 759         case READ_12:
 760                 sectors = transport_get_sectors_12(cdb);
 761                 cmd->t_task_lba = transport_lba_32(cdb);
 762
 763                 if (sbc_check_dpofua(dev, cmd, cdb))
 764                         return TCM_INVALID_CDB_FIELD;
 765
 766                 ret = sbc_check_prot(dev, cmd, cdb, sectors, false);
 767                 if (ret)
 768                         return ret;
 769
 770                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 771                 cmd->execute_rw = ops->execute_rw;
 772                 cmd->execute_cmd = sbc_execute_rw;
 773                 break;
 774         case READ_16:
 775                 sectors = transport_get_sectors_16(cdb);
 776                 cmd->t_task_lba = transport_lba_64(cdb);
 777
 778                 if (sbc_check_dpofua(dev, cmd, cdb))
 779                         return TCM_INVALID_CDB_FIELD;
 780
 781                 ret = sbc_check_prot(dev, cmd, cdb, sectors, false);
 782                 if (ret)
 783                         return ret;
 784
 785                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 786                 cmd->execute_rw = ops->execute_rw;
 787                 cmd->execute_cmd = sbc_execute_rw;
 788                 break;
 789         case WRITE_6:
 790                 sectors = transport_get_sectors_6(cdb);
 791                 cmd->t_task_lba = transport_lba_21(cdb);
 792                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 793                 cmd->execute_rw = ops->execute_rw;
 794                 cmd->execute_cmd = sbc_execute_rw;
 795                 break;
 796         case WRITE_10:
 797         case WRITE_VERIFY:
 798                 sectors = transport_get_sectors_10(cdb);
 799                 cmd->t_task_lba = transport_lba_32(cdb);
 800
 801                 if (sbc_check_dpofua(dev, cmd, cdb))
 802                         return TCM_INVALID_CDB_FIELD;
 803
 804                 ret = sbc_check_prot(dev, cmd, cdb, sectors, true);
 805                 if (ret)
 806                         return ret;
 807
 808                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 809                 cmd->execute_rw = ops->execute_rw;
 810                 cmd->execute_cmd = sbc_execute_rw;
 811                 break;
 812         case WRITE_12:
 813                 sectors = transport_get_sectors_12(cdb);
 814                 cmd->t_task_lba = transport_lba_32(cdb);
 815
 816                 if (sbc_check_dpofua(dev, cmd, cdb))
 817                         return TCM_INVALID_CDB_FIELD;
 818
 819                 ret = sbc_check_prot(dev, cmd, cdb, sectors, true);
 820                 if (ret)
 821                         return ret;
 822
 823                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 824                 cmd->execute_rw = ops->execute_rw;
 825                 cmd->execute_cmd = sbc_execute_rw;
 826                 break;
 827         case WRITE_16:
 828                 sectors = transport_get_sectors_16(cdb);
 829                 cmd->t_task_lba = transport_lba_64(cdb);
 830
 831                 if (sbc_check_dpofua(dev, cmd, cdb))
 832                         return TCM_INVALID_CDB_FIELD;
 833
 834                 ret = sbc_check_prot(dev, cmd, cdb, sectors, true);
 835                 if (ret)
 836                         return ret;
 837
 838                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 839                 cmd->execute_rw = ops->execute_rw;
 840                 cmd->execute_cmd = sbc_execute_rw;
 841                 break;
 842         case XDWRITEREAD_10:
 843                 if (cmd->data_direction != DMA_TO_DEVICE ||
 844                     !(cmd->se_cmd_flags & SCF_BIDI))
 845                         return TCM_INVALID_CDB_FIELD;
 846                 sectors = transport_get_sectors_10(cdb);
 847
 848                 if (sbc_check_dpofua(dev, cmd, cdb))
 849                         return TCM_INVALID_CDB_FIELD;
 850
 851                 cmd->t_task_lba = transport_lba_32(cdb);
 852                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 853
 854                 /*
 855                  * Setup BIDI XOR callback to be run after I/O completion.
 856                  */
 857                 cmd->execute_rw = ops->execute_rw;
 858                 cmd->execute_cmd = sbc_execute_rw;
 859                 cmd->transport_complete_callback = &xdreadwrite_callback;
 860                 break;
 861         case VARIABLE_LENGTH_CMD:
 862         {
 863                 u16 service_action = get_unaligned_be16(&cdb[8]);
 864                 switch (service_action) {
 865                 case XDWRITEREAD_32:
 866                         sectors = transport_get_sectors_32(cdb);
 867
 868                         if (sbc_check_dpofua(dev, cmd, cdb))
 869                                 return TCM_INVALID_CDB_FIELD;
 870                         /*
 871                          * Use WRITE_32 and READ_32 opcodes for the emulated
 872                          * XDWRITE_READ_32 logic.
 873                          */
 874                         cmd->t_task_lba = transport_lba_64_ext(cdb);
 875                         cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 876
 877                         /*
 878                          * Setup BIDI XOR callback to be run during after I/O
 879                          * completion.
 880                          */
 881                         cmd->execute_rw = ops->execute_rw;
 882                         cmd->execute_cmd = sbc_execute_rw;
 883                         cmd->transport_complete_callback = &xdreadwrite_callback;
 884                         break;
 885                 case WRITE_SAME_32:
 886                         sectors = transport_get_sectors_32(cdb);
 887                         if (!sectors) {
 888                                 pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not"
 889                                        " supported\n");
 890                                 return TCM_INVALID_CDB_FIELD;
 891                         }
 892
 893                         size = sbc_get_size(cmd, 1);
 894                         cmd->t_task_lba = get_unaligned_be64(&cdb[12]);
 895
 896                         ret = sbc_setup_write_same(cmd, &cdb[10], ops);
 897                         if (ret)
 898                                 return ret;
 899                         break;
 900                 default:
 901                         pr_err("VARIABLE_LENGTH_CMD service action"
 902                                 " 0x%04x not supported\n", service_action);
 903                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 904                 }
 905                 break;
 906         }
 907         case COMPARE_AND_WRITE:
 908                 sectors = cdb[13];
 909                 /*
 910                  * Currently enforce COMPARE_AND_WRITE for a single sector
 911                  */
 912                 if (sectors > 1) {
 913                         pr_err("COMPARE_AND_WRITE contains NoLB: %u greater"
 914                                " than 1\n", sectors);
 915                         return TCM_INVALID_CDB_FIELD;
 916                 }
 917                 /*
 918                  * Double size because we have two buffers, note that
 919                  * zero is not an error..
 920                  */
 921                 size = 2 * sbc_get_size(cmd, sectors);
 922                 cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
 923                 cmd->t_task_nolb = sectors;
 924                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB | SCF_COMPARE_AND_WRITE;
 925                 cmd->execute_rw = ops->execute_rw;
 926                 cmd->execute_cmd = sbc_compare_and_write;
 927                 cmd->transport_complete_callback = compare_and_write_callback;
 928                 break;
 929         case READ_CAPACITY:
 930                 size = READ_CAP_LEN;
 931                 cmd->execute_cmd = sbc_emulate_readcapacity;
 932                 break;
 933         case SERVICE_ACTION_IN_16:
 934                 switch (cmd->t_task_cdb[1] & 0x1f) {
 935                 case SAI_READ_CAPACITY_16:
 936                         cmd->execute_cmd = sbc_emulate_readcapacity_16;
 937                         break;
 938                 case SAI_REPORT_REFERRALS:
 939                         cmd->execute_cmd = target_emulate_report_referrals;
 940                         break;
 941                 default:
 942                         pr_err("Unsupported SA: 0x%02x\n",
 943                                 cmd->t_task_cdb[1] & 0x1f);
 944                         return TCM_INVALID_CDB_FIELD;
 945                 }
 946                 size = (cdb[10] << 24) | (cdb[11] << 16) |
 947                        (cdb[12] << 8) | cdb[13];
 948                 break;
 949         case SYNCHRONIZE_CACHE:
 950         case SYNCHRONIZE_CACHE_16:
 951                 if (cdb[0] == SYNCHRONIZE_CACHE) {
 952                         sectors = transport_get_sectors_10(cdb);
 953                         cmd->t_task_lba = transport_lba_32(cdb);
 954                 } else {
 955                         sectors = transport_get_sectors_16(cdb);
 956                         cmd->t_task_lba = transport_lba_64(cdb);
 957                 }
 958                 if (ops->execute_sync_cache) {
 959                         cmd->execute_cmd = ops->execute_sync_cache;
 960                         goto check_lba;
 961                 }
 962                 size = 0;
 963                 cmd->execute_cmd = sbc_emulate_noop;
 964                 break;
 965         case UNMAP:
 966                 if (!ops->execute_unmap)
 967                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 968
 969                 if (!dev->dev_attrib.emulate_tpu) {
 970                         pr_err("Got UNMAP, but backend device has"
 971                                " emulate_tpu disabled\n");
 972                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 973                 }
 974                 size = get_unaligned_be16(&cdb[7]);
 975                 cmd->execute_cmd = ops->execute_unmap;
 976                 break;
 977         case WRITE_SAME_16:
 978                 sectors = transport_get_sectors_16(cdb);
 979                 if (!sectors) {
 980                         pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
 981                         return TCM_INVALID_CDB_FIELD;
 982                 }
 983
 984                 size = sbc_get_size(cmd, 1);
 985                 cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
 986
 987                 ret = sbc_setup_write_same(cmd, &cdb[1], ops);
 988                 if (ret)
 989                         return ret;
 990                 break;
 991         case WRITE_SAME:
 992                 sectors = transport_get_sectors_10(cdb);
 993                 if (!sectors) {
 994                         pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
 995                         return TCM_INVALID_CDB_FIELD;
 996                 }
 997
 998                 size = sbc_get_size(cmd, 1);
 999                 cmd->t_task_lba = get_unaligned_be32(&cdb[2]);
1000
1001                 /*
1002                  * Follow sbcr26 with WRITE_SAME (10) and check for the existence
1003                  * of byte 1 bit 3 UNMAP instead of original reserved field
1004                  */
1005                 ret = sbc_setup_write_same(cmd, &cdb[1], ops);
1006                 if (ret)
1007                         return ret;
1008                 break;
1009         case VERIFY:
1010                 size = 0;
1011                 sectors = transport_get_sectors_10(cdb);
1012                 cmd->t_task_lba = transport_lba_32(cdb);
1013                 cmd->execute_cmd = sbc_emulate_noop;
1014                 goto check_lba;
1015         case REZERO_UNIT:
1016         case SEEK_6:
1017         case SEEK_10:
1018                 /*
1019                  * There are still clients out there which use these old SCSI-2
1020                  * commands. This mainly happens when running VMs with legacy
1021                  * guest systems, connected via SCSI command pass-through to
1022                  * iSCSI targets. Make them happy and return status GOOD.
1023                  */
1024                 size = 0;
1025                 cmd->execute_cmd = sbc_emulate_noop;
1026                 break;
1027         default:
1028                 ret = spc_parse_cdb(cmd, &size);
1029                 if (ret)
1030                         return ret;
1031         }
1032
1033         /* reject any command that we don't have a handler for */
1034         if (!cmd->execute_cmd)
1035                 return TCM_UNSUPPORTED_SCSI_OPCODE;
1036
1037         if (cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
1038                 unsigned long long end_lba;
1039 check_lba:
1040                 end_lba = dev->transport->get_blocks(dev) + 1;
1041                 if (((cmd->t_task_lba + sectors) < cmd->t_task_lba) ||
1042                     ((cmd->t_task_lba + sectors) > end_lba)) {
1043                         pr_err("cmd exceeds last lba %llu "
1044                                 "(lba %llu, sectors %u)\n",
1045                                 end_lba, cmd->t_task_lba, sectors);
1046                         return TCM_ADDRESS_OUT_OF_RANGE;
1047                 }
1048
1049                 if (!(cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE))
1050                         size = sbc_get_size(cmd, sectors);
1051         }
1052
1053         return target_cmd_size_check(cmd, size);
1054 }
1055 EXPORT_SYMBOL(sbc_parse_cdb);
1056
1057 u32 sbc_get_device_type(struct se_device *dev)
1058 {
1059         return TYPE_DISK;
1060 }
1061 EXPORT_SYMBOL(sbc_get_device_type);
1062
1063 sense_reason_t
1064 sbc_execute_unmap(struct se_cmd *cmd,
1065         sense_reason_t (*do_unmap_fn)(struct se_cmd *, void *,
1066                                       sector_t, sector_t),
1067         void *priv)
1068 {
1069         struct se_device *dev = cmd->se_dev;
1070         unsigned char *buf, *ptr = NULL;
1071         sector_t lba;
1072         int size;
1073         u32 range;
1074         sense_reason_t ret = 0;
1075         int dl, bd_dl;
1076
1077         /* We never set ANC_SUP */
1078         if (cmd->t_task_cdb[1])
1079                 return TCM_INVALID_CDB_FIELD;
1080
1081         if (cmd->data_length == 0) {
1082                 target_complete_cmd(cmd, SAM_STAT_GOOD);
1083                 return 0;
1084         }
1085
1086         if (cmd->data_length < 8) {
1087                 pr_warn("UNMAP parameter list length %u too small\n",
1088                         cmd->data_length);
1089                 return TCM_PARAMETER_LIST_LENGTH_ERROR;
1090         }
1091
1092         buf = transport_kmap_data_sg(cmd);
1093         if (!buf)
1094                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1095
1096         dl = get_unaligned_be16(&buf[0]);
1097         bd_dl = get_unaligned_be16(&buf[2]);
1098
1099         size = cmd->data_length - 8;
1100         if (bd_dl > size)
1101                 pr_warn("UNMAP parameter list length %u too small, ignoring bd_dl %u\n",
1102                         cmd->data_length, bd_dl);
1103         else
1104                 size = bd_dl;
1105
1106         if (size / 16 > dev->dev_attrib.max_unmap_block_desc_count) {
1107                 ret = TCM_INVALID_PARAMETER_LIST;
1108                 goto err;
1109         }
1110
1111         /* First UNMAP block descriptor starts at 8 byte offset */
1112         ptr = &buf[8];
1113         pr_debug("UNMAP: Sub: %s Using dl: %u bd_dl: %u size: %u"
1114                 " ptr: %p\n", dev->transport->name, dl, bd_dl, size, ptr);
1115
1116         while (size >= 16) {
1117                 lba = get_unaligned_be64(&ptr[0]);
1118                 range = get_unaligned_be32(&ptr[8]);
1119                 pr_debug("UNMAP: Using lba: %llu and range: %u\n",
1120                                  (unsigned long long)lba, range);
1121
1122                 if (range > dev->dev_attrib.max_unmap_lba_count) {
1123                         ret = TCM_INVALID_PARAMETER_LIST;
1124                         goto err;
1125                 }
1126
1127                 if (lba + range > dev->transport->get_blocks(dev) + 1) {
1128                         ret = TCM_ADDRESS_OUT_OF_RANGE;
1129                         goto err;
1130                 }
1131
1132                 ret = do_unmap_fn(cmd, priv, lba, range);
1133                 if (ret)
1134                         goto err;
1135
1136                 ptr += 16;
1137                 size -= 16;
1138         }
1139
1140 err:
1141         transport_kunmap_data_sg(cmd);
1142         if (!ret)
1143                 target_complete_cmd(cmd, GOOD);
1144         return ret;
1145 }
1146 EXPORT_SYMBOL(sbc_execute_unmap);
1147
1148 void
1149 sbc_dif_generate(struct se_cmd *cmd)
1150 {
1151         struct se_device *dev = cmd->se_dev;
1152         struct se_dif_v1_tuple *sdt;
1153         struct scatterlist *dsg, *psg = cmd->t_prot_sg;
1154         sector_t sector = cmd->t_task_lba;
1155         void *daddr, *paddr;
1156         int i, j, offset = 0;
1157
1158         for_each_sg(cmd->t_data_sg, dsg, cmd->t_data_nents, i) {
1159                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1160                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1161
1162                 for (j = 0; j < dsg->length; j += dev->dev_attrib.block_size) {
1163
1164                         if (offset >= psg->length) {
1165                                 kunmap_atomic(paddr);
1166                                 psg = sg_next(psg);
1167                                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1168                                 offset = 0;
1169                         }
1170
1171                         sdt = paddr + offset;
1172                         sdt->guard_tag = cpu_to_be16(crc_t10dif(daddr + j,
1173                                                 dev->dev_attrib.block_size));
1174                         if (dev->dev_attrib.pi_prot_type == TARGET_DIF_TYPE1_PROT)
1175                                 sdt->ref_tag = cpu_to_be32(sector & 0xffffffff);
1176                         sdt->app_tag = 0;
1177
1178                         pr_debug("DIF WRITE INSERT sector: %llu guard_tag: 0x%04x"
1179                                  " app_tag: 0x%04x ref_tag: %u\n",
1180                                  (unsigned long long)sector, sdt->guard_tag,
1181                                  sdt->app_tag, be32_to_cpu(sdt->ref_tag));
1182
1183                         sector++;
1184                         offset += sizeof(struct se_dif_v1_tuple);
1185                 }
1186
1187                 kunmap_atomic(paddr);
1188                 kunmap_atomic(daddr);
1189         }
1190 }
1191
1192 static sense_reason_t
1193 sbc_dif_v1_verify(struct se_device *dev, struct se_dif_v1_tuple *sdt,
1194                   const void *p, sector_t sector, unsigned int ei_lba)
1195 {
1196         int block_size = dev->dev_attrib.block_size;
1197         __be16 csum;
1198
1199         csum = cpu_to_be16(crc_t10dif(p, block_size));
1200
1201         if (sdt->guard_tag != csum) {
1202                 pr_err("DIFv1 checksum failed on sector %llu guard tag 0x%04x"
1203                         " csum 0x%04x\n", (unsigned long long)sector,
1204                         be16_to_cpu(sdt->guard_tag), be16_to_cpu(csum));
1205                 return TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED;
1206         }
1207
1208         if (dev->dev_attrib.pi_prot_type == TARGET_DIF_TYPE1_PROT &&
1209             be32_to_cpu(sdt->ref_tag) != (sector & 0xffffffff)) {
1210                 pr_err("DIFv1 Type 1 reference failed on sector: %llu tag: 0x%08x"
1211                        " sector MSB: 0x%08x\n", (unsigned long long)sector,
1212                        be32_to_cpu(sdt->ref_tag), (u32)(sector & 0xffffffff));
1213                 return TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;
1214         }
1215
1216         if (dev->dev_attrib.pi_prot_type == TARGET_DIF_TYPE2_PROT &&
1217             be32_to_cpu(sdt->ref_tag) != ei_lba) {
1218                 pr_err("DIFv1 Type 2 reference failed on sector: %llu tag: 0x%08x"
1219                        " ei_lba: 0x%08x\n", (unsigned long long)sector,
1220                         be32_to_cpu(sdt->ref_tag), ei_lba);
1221                 return TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;
1222         }
1223
1224         return 0;
1225 }
1226
1227 static void
1228 sbc_dif_copy_prot(struct se_cmd *cmd, unsigned int sectors, bool read,
1229                   struct scatterlist *sg, int sg_off)
1230 {
1231         struct se_device *dev = cmd->se_dev;
1232         struct scatterlist *psg;
1233         void *paddr, *addr;
1234         unsigned int i, len, left;
1235         unsigned int offset = sg_off;
1236
1237         left = sectors * dev->prot_length;
1238
1239         for_each_sg(cmd->t_prot_sg, psg, cmd->t_prot_nents, i) {
1240                 unsigned int psg_len, copied = 0;
1241
1242                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1243                 psg_len = min(left, psg->length);
1244                 while (psg_len) {
1245                         len = min(psg_len, sg->length - offset);
1246                         addr = kmap_atomic(sg_page(sg)) + sg->offset + offset;
1247
1248                         if (read)
1249                                 memcpy(paddr + copied, addr, len);
1250                         else
1251                                 memcpy(addr, paddr + copied, len);
1252
1253                         left -= len;
1254                         offset += len;
1255                         copied += len;
1256                         psg_len -= len;
1257
1258                         if (offset >= sg->length) {
1259                                 sg = sg_next(sg);
1260                                 offset = 0;
1261                         }
1262                         kunmap_atomic(addr);
1263                 }
1264                 kunmap_atomic(paddr);
1265         }
1266 }
1267
1268 sense_reason_t
1269 sbc_dif_verify_write(struct se_cmd *cmd, sector_t start, unsigned int sectors,
1270                      unsigned int ei_lba, struct scatterlist *sg, int sg_off)
1271 {
1272         struct se_device *dev = cmd->se_dev;
1273         struct se_dif_v1_tuple *sdt;
1274         struct scatterlist *dsg, *psg = cmd->t_prot_sg;
1275         sector_t sector = start;
1276         void *daddr, *paddr;
1277         int i, j, offset = 0;
1278         sense_reason_t rc;
1279
1280         for_each_sg(cmd->t_data_sg, dsg, cmd->t_data_nents, i) {
1281                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1282                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1283
1284                 for (j = 0; j < dsg->length; j += dev->dev_attrib.block_size) {
1285
1286                         if (offset >= psg->length) {
1287                                 kunmap_atomic(paddr);
1288                                 psg = sg_next(psg);
1289                                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1290                                 offset = 0;
1291                         }
1292
1293                         sdt = paddr + offset;
1294
1295                         pr_debug("DIF WRITE sector: %llu guard_tag: 0x%04x"
1296                                  " app_tag: 0x%04x ref_tag: %u\n",
1297                                  (unsigned long long)sector, sdt->guard_tag,
1298                                  sdt->app_tag, be32_to_cpu(sdt->ref_tag));
1299
1300                         rc = sbc_dif_v1_verify(dev, sdt, daddr + j, sector,
1301                                                ei_lba);
1302                         if (rc) {
1303                                 kunmap_atomic(paddr);
1304                                 kunmap_atomic(daddr);
1305                                 cmd->bad_sector = sector;
1306                                 return rc;
1307                         }
1308
1309                         sector++;
1310                         ei_lba++;
1311                         offset += sizeof(struct se_dif_v1_tuple);
1312                 }
1313
1314                 kunmap_atomic(paddr);
1315                 kunmap_atomic(daddr);
1316         }
1317         sbc_dif_copy_prot(cmd, sectors, false, sg, sg_off);
1318
1319         return 0;
1320 }
1321 EXPORT_SYMBOL(sbc_dif_verify_write);
1322
1323 static sense_reason_t
1324 __sbc_dif_verify_read(struct se_cmd *cmd, sector_t start, unsigned int sectors,
1325                       unsigned int ei_lba, struct scatterlist *sg, int sg_off)
1326 {
1327         struct se_device *dev = cmd->se_dev;
1328         struct se_dif_v1_tuple *sdt;
1329         struct scatterlist *dsg, *psg = sg;
1330         sector_t sector = start;
1331         void *daddr, *paddr;
1332         int i, j, offset = sg_off;
1333         sense_reason_t rc;
1334
1335         for_each_sg(cmd->t_data_sg, dsg, cmd->t_data_nents, i) {
1336                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1337                 paddr = kmap_atomic(sg_page(psg)) + sg->offset;
1338
1339                 for (j = 0; j < dsg->length; j += dev->dev_attrib.block_size) {
1340
1341                         if (offset >= psg->length) {
1342                                 kunmap_atomic(paddr);
1343                                 psg = sg_next(psg);
1344                                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1345                                 offset = 0;
1346                         }
1347
1348                         sdt = paddr + offset;
1349
1350                         pr_debug("DIF READ sector: %llu guard_tag: 0x%04x"
1351                                  " app_tag: 0x%04x ref_tag: %u\n",
1352                                  (unsigned long long)sector, sdt->guard_tag,
1353                                  sdt->app_tag, be32_to_cpu(sdt->ref_tag));
1354
1355                         if (sdt->app_tag == cpu_to_be16(0xffff)) {
1356                                 sector++;
1357                                 offset += sizeof(struct se_dif_v1_tuple);
1358                                 continue;
1359                         }
1360
1361                         rc = sbc_dif_v1_verify(dev, sdt, daddr + j, sector,
1362                                                ei_lba);
1363                         if (rc) {
1364                                 kunmap_atomic(paddr);
1365                                 kunmap_atomic(daddr);
1366                                 cmd->bad_sector = sector;
1367                                 return rc;
1368                         }
1369
1370                         sector++;
1371                         ei_lba++;
1372                         offset += sizeof(struct se_dif_v1_tuple);
1373                 }
1374
1375                 kunmap_atomic(paddr);
1376                 kunmap_atomic(daddr);
1377         }
1378
1379         return 0;
1380 }
1381
1382 sense_reason_t
1383 sbc_dif_read_strip(struct se_cmd *cmd)
1384 {
1385         struct se_device *dev = cmd->se_dev;
1386         u32 sectors = cmd->prot_length / dev->prot_length;
1387
1388         return __sbc_dif_verify_read(cmd, cmd->t_task_lba, sectors, 0,
1389                                      cmd->t_prot_sg, 0);
1390 }
1391
1392 sense_reason_t
1393 sbc_dif_verify_read(struct se_cmd *cmd, sector_t start, unsigned int sectors,
1394                     unsigned int ei_lba, struct scatterlist *sg, int sg_off)
1395 {
1396         sense_reason_t rc;
1397
1398         rc = __sbc_dif_verify_read(cmd, start, sectors, ei_lba, sg, sg_off);
1399         if (rc)
1400                 return rc;
1401
1402         sbc_dif_copy_prot(cmd, sectors, true, sg, sg_off);
1403         return 0;
1404 }
1405 EXPORT_SYMBOL(sbc_dif_verify_read);