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_emulate_readcapacity(struct se_cmd *cmd)
  41 {
  42         struct se_device *dev = cmd->se_dev;
  43         unsigned char *cdb = cmd->t_task_cdb;
  44         unsigned long long blocks_long = dev->transport->get_blocks(dev);
  45         unsigned char *rbuf;
  46         unsigned char buf[8];
  47         u32 blocks;
  48
  49         /*
  50          * SBC-2 says:
  51          *   If the PMI bit is set to zero and the LOGICAL BLOCK
  52          *   ADDRESS field is not set to zero, the device server shall
  53          *   terminate the command with CHECK CONDITION status with
  54          *   the sense key set to ILLEGAL REQUEST and the additional
  55          *   sense code set to INVALID FIELD IN CDB.
  56          *
  57          * In SBC-3, these fields are obsolete, but some SCSI
  58          * compliance tests actually check this, so we might as well
  59          * follow SBC-2.
  60          */
  61         if (!(cdb[8] & 1) && !!(cdb[2] | cdb[3] | cdb[4] | cdb[5]))
  62                 return TCM_INVALID_CDB_FIELD;
  63
  64         if (blocks_long >= 0x00000000ffffffff)
  65                 blocks = 0xffffffff;
  66         else
  67                 blocks = (u32)blocks_long;
  68
  69         buf[0] = (blocks >> 24) & 0xff;
  70         buf[1] = (blocks >> 16) & 0xff;
  71         buf[2] = (blocks >> 8) & 0xff;
  72         buf[3] = blocks & 0xff;
  73         buf[4] = (dev->dev_attrib.block_size >> 24) & 0xff;
  74         buf[5] = (dev->dev_attrib.block_size >> 16) & 0xff;
  75         buf[6] = (dev->dev_attrib.block_size >> 8) & 0xff;
  76         buf[7] = dev->dev_attrib.block_size & 0xff;
  77
  78         rbuf = transport_kmap_data_sg(cmd);
  79         if (rbuf) {
  80                 memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length));
  81                 transport_kunmap_data_sg(cmd);
  82         }
  83
  84         target_complete_cmd(cmd, GOOD);
  85         return 0;
  86 }
  87
  88 static sense_reason_t
  89 sbc_emulate_readcapacity_16(struct se_cmd *cmd)
  90 {
  91         struct se_device *dev = cmd->se_dev;
  92         unsigned char *rbuf;
  93         unsigned char buf[32];
  94         unsigned long long blocks = dev->transport->get_blocks(dev);
  95
  96         memset(buf, 0, sizeof(buf));
  97         buf[0] = (blocks >> 56) & 0xff;
  98         buf[1] = (blocks >> 48) & 0xff;
  99         buf[2] = (blocks >> 40) & 0xff;
 100         buf[3] = (blocks >> 32) & 0xff;
 101         buf[4] = (blocks >> 24) & 0xff;
 102         buf[5] = (blocks >> 16) & 0xff;
 103         buf[6] = (blocks >> 8) & 0xff;
 104         buf[7] = blocks & 0xff;
 105         buf[8] = (dev->dev_attrib.block_size >> 24) & 0xff;
 106         buf[9] = (dev->dev_attrib.block_size >> 16) & 0xff;
 107         buf[10] = (dev->dev_attrib.block_size >> 8) & 0xff;
 108         buf[11] = dev->dev_attrib.block_size & 0xff;
 109         /*
 110          * Set P_TYPE and PROT_EN bits for DIF support
 111          */
 112         if (dev->dev_attrib.pi_prot_type)
 113                 buf[12] = (dev->dev_attrib.pi_prot_type - 1) << 1 | 0x1;
 114
 115         if (dev->transport->get_lbppbe)
 116                 buf[13] = dev->transport->get_lbppbe(dev) & 0x0f;
 117
 118         if (dev->transport->get_alignment_offset_lbas) {
 119                 u16 lalba = dev->transport->get_alignment_offset_lbas(dev);
 120                 buf[14] = (lalba >> 8) & 0x3f;
 121                 buf[15] = lalba & 0xff;
 122         }
 123
 124         /*
 125          * Set Thin Provisioning Enable bit following sbc3r22 in section
 126          * READ CAPACITY (16) byte 14 if emulate_tpu or emulate_tpws is enabled.
 127          */
 128         if (dev->dev_attrib.emulate_tpu || dev->dev_attrib.emulate_tpws)
 129                 buf[14] |= 0x80;
 130
 131         rbuf = transport_kmap_data_sg(cmd);
 132         if (rbuf) {
 133                 memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length));
 134                 transport_kunmap_data_sg(cmd);
 135         }
 136
 137         target_complete_cmd(cmd, GOOD);
 138         return 0;
 139 }
 140
 141 sector_t sbc_get_write_same_sectors(struct se_cmd *cmd)
 142 {
 143         u32 num_blocks;
 144
 145         if (cmd->t_task_cdb[0] == WRITE_SAME)
 146                 num_blocks = get_unaligned_be16(&cmd->t_task_cdb[7]);
 147         else if (cmd->t_task_cdb[0] == WRITE_SAME_16)
 148                 num_blocks = get_unaligned_be32(&cmd->t_task_cdb[10]);
 149         else /* WRITE_SAME_32 via VARIABLE_LENGTH_CMD */
 150                 num_blocks = get_unaligned_be32(&cmd->t_task_cdb[28]);
 151
 152         /*
 153          * Use the explicit range when non zero is supplied, otherwise calculate
 154          * the remaining range based on ->get_blocks() - starting LBA.
 155          */
 156         if (num_blocks)
 157                 return num_blocks;
 158
 159         return cmd->se_dev->transport->get_blocks(cmd->se_dev) -
 160                 cmd->t_task_lba + 1;
 161 }
 162 EXPORT_SYMBOL(sbc_get_write_same_sectors);
 163
 164 static sense_reason_t
 165 sbc_emulate_noop(struct se_cmd *cmd)
 166 {
 167         target_complete_cmd(cmd, GOOD);
 168         return 0;
 169 }
 170
 171 static inline u32 sbc_get_size(struct se_cmd *cmd, u32 sectors)
 172 {
 173         return cmd->se_dev->dev_attrib.block_size * sectors;
 174 }
 175
 176 static int sbc_check_valid_sectors(struct se_cmd *cmd)
 177 {
 178         struct se_device *dev = cmd->se_dev;
 179         unsigned long long end_lba;
 180         u32 sectors;
 181
 182         sectors = cmd->data_length / dev->dev_attrib.block_size;
 183         end_lba = dev->transport->get_blocks(dev) + 1;
 184
 185         if (cmd->t_task_lba + sectors > end_lba) {
 186                 pr_err("target: lba %llu, sectors %u exceeds end lba %llu\n",
 187                         cmd->t_task_lba, sectors, end_lba);
 188                 return -EINVAL;
 189         }
 190
 191         return 0;
 192 }
 193
 194 static inline u32 transport_get_sectors_6(unsigned char *cdb)
 195 {
 196         /*
 197          * Use 8-bit sector value.  SBC-3 says:
 198          *
 199          *   A TRANSFER LENGTH field set to zero specifies that 256
 200          *   logical blocks shall be written.  Any other value
 201          *   specifies the number of logical blocks that shall be
 202          *   written.
 203          */
 204         return cdb[4] ? : 256;
 205 }
 206
 207 static inline u32 transport_get_sectors_10(unsigned char *cdb)
 208 {
 209         return (u32)(cdb[7] << 8) + cdb[8];
 210 }
 211
 212 static inline u32 transport_get_sectors_12(unsigned char *cdb)
 213 {
 214         return (u32)(cdb[6] << 24) + (cdb[7] << 16) + (cdb[8] << 8) + cdb[9];
 215 }
 216
 217 static inline u32 transport_get_sectors_16(unsigned char *cdb)
 218 {
 219         return (u32)(cdb[10] << 24) + (cdb[11] << 16) +
 220                     (cdb[12] << 8) + cdb[13];
 221 }
 222
 223 /*
 224  * Used for VARIABLE_LENGTH_CDB WRITE_32 and READ_32 variants
 225  */
 226 static inline u32 transport_get_sectors_32(unsigned char *cdb)
 227 {
 228         return (u32)(cdb[28] << 24) + (cdb[29] << 16) +
 229                     (cdb[30] << 8) + cdb[31];
 230
 231 }
 232
 233 static inline u32 transport_lba_21(unsigned char *cdb)
 234 {
 235         return ((cdb[1] & 0x1f) << 16) | (cdb[2] << 8) | cdb[3];
 236 }
 237
 238 static inline u32 transport_lba_32(unsigned char *cdb)
 239 {
 240         return (cdb[2] << 24) | (cdb[3] << 16) | (cdb[4] << 8) | cdb[5];
 241 }
 242
 243 static inline unsigned long long transport_lba_64(unsigned char *cdb)
 244 {
 245         unsigned int __v1, __v2;
 246
 247         __v1 = (cdb[2] << 24) | (cdb[3] << 16) | (cdb[4] << 8) | cdb[5];
 248         __v2 = (cdb[6] << 24) | (cdb[7] << 16) | (cdb[8] << 8) | cdb[9];
 249
 250         return ((unsigned long long)__v2) | (unsigned long long)__v1 << 32;
 251 }
 252
 253 /*
 254  * For VARIABLE_LENGTH_CDB w/ 32 byte extended CDBs
 255  */
 256 static inline unsigned long long transport_lba_64_ext(unsigned char *cdb)
 257 {
 258         unsigned int __v1, __v2;
 259
 260         __v1 = (cdb[12] << 24) | (cdb[13] << 16) | (cdb[14] << 8) | cdb[15];
 261         __v2 = (cdb[16] << 24) | (cdb[17] << 16) | (cdb[18] << 8) | cdb[19];
 262
 263         return ((unsigned long long)__v2) | (unsigned long long)__v1 << 32;
 264 }
 265
 266 static sense_reason_t
 267 sbc_setup_write_same(struct se_cmd *cmd, unsigned char *flags, struct sbc_ops *ops)
 268 {
 269         unsigned int sectors = sbc_get_write_same_sectors(cmd);
 270
 271         if ((flags[0] & 0x04) || (flags[0] & 0x02)) {
 272                 pr_err("WRITE_SAME PBDATA and LBDATA"
 273                         " bits not supported for Block Discard"
 274                         " Emulation\n");
 275                 return TCM_UNSUPPORTED_SCSI_OPCODE;
 276         }
 277         if (sectors > cmd->se_dev->dev_attrib.max_write_same_len) {
 278                 pr_warn("WRITE_SAME sectors: %u exceeds max_write_same_len: %u\n",
 279                         sectors, cmd->se_dev->dev_attrib.max_write_same_len);
 280                 return TCM_INVALID_CDB_FIELD;
 281         }
 282         /* We always have ANC_SUP == 0 so setting ANCHOR is always an error */
 283         if (flags[0] & 0x10) {
 284                 pr_warn("WRITE SAME with ANCHOR not supported\n");
 285                 return TCM_INVALID_CDB_FIELD;
 286         }
 287         /*
 288          * Special case for WRITE_SAME w/ UNMAP=1 that ends up getting
 289          * translated into block discard requests within backend code.
 290          */
 291         if (flags[0] & 0x08) {
 292                 if (!ops->execute_write_same_unmap)
 293                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 294
 295                 cmd->execute_cmd = ops->execute_write_same_unmap;
 296                 return 0;
 297         }
 298         if (!ops->execute_write_same)
 299                 return TCM_UNSUPPORTED_SCSI_OPCODE;
 300
 301         cmd->execute_cmd = ops->execute_write_same;
 302         return 0;
 303 }
 304
 305 static sense_reason_t xdreadwrite_callback(struct se_cmd *cmd)
 306 {
 307         unsigned char *buf, *addr;
 308         struct scatterlist *sg;
 309         unsigned int offset;
 310         sense_reason_t ret = TCM_NO_SENSE;
 311         int i, count;
 312         /*
 313          * From sbc3r22.pdf section 5.48 XDWRITEREAD (10) command
 314          *
 315          * 1) read the specified logical block(s);
 316          * 2) transfer logical blocks from the data-out buffer;
 317          * 3) XOR the logical blocks transferred from the data-out buffer with
 318          *    the logical blocks read, storing the resulting XOR data in a buffer;
 319          * 4) if the DISABLE WRITE bit is set to zero, then write the logical
 320          *    blocks transferred from the data-out buffer; and
 321          * 5) transfer the resulting XOR data to the data-in buffer.
 322          */
 323         buf = kmalloc(cmd->data_length, GFP_KERNEL);
 324         if (!buf) {
 325                 pr_err("Unable to allocate xor_callback buf\n");
 326                 return TCM_OUT_OF_RESOURCES;
 327         }
 328         /*
 329          * Copy the scatterlist WRITE buffer located at cmd->t_data_sg
 330          * into the locally allocated *buf
 331          */
 332         sg_copy_to_buffer(cmd->t_data_sg,
 333                           cmd->t_data_nents,
 334                           buf,
 335                           cmd->data_length);
 336
 337         /*
 338          * Now perform the XOR against the BIDI read memory located at
 339          * cmd->t_mem_bidi_list
 340          */
 341
 342         offset = 0;
 343         for_each_sg(cmd->t_bidi_data_sg, sg, cmd->t_bidi_data_nents, count) {
 344                 addr = kmap_atomic(sg_page(sg));
 345                 if (!addr) {
 346                         ret = TCM_OUT_OF_RESOURCES;
 347                         goto out;
 348                 }
 349
 350                 for (i = 0; i < sg->length; i++)
 351                         *(addr + sg->offset + i) ^= *(buf + offset + i);
 352
 353                 offset += sg->length;
 354                 kunmap_atomic(addr);
 355         }
 356
 357 out:
 358         kfree(buf);
 359         return ret;
 360 }
 361
 362 static sense_reason_t
 363 sbc_execute_rw(struct se_cmd *cmd)
 364 {
 365         return cmd->execute_rw(cmd, cmd->t_data_sg, cmd->t_data_nents,
 366                                cmd->data_direction);
 367 }
 368
 369 static sense_reason_t compare_and_write_post(struct se_cmd *cmd)
 370 {
 371         struct se_device *dev = cmd->se_dev;
 372
 373         /*
 374          * Only set SCF_COMPARE_AND_WRITE_POST to force a response fall-through
 375          * within target_complete_ok_work() if the command was successfully
 376          * sent to the backend driver.
 377          */
 378         spin_lock_irq(&cmd->t_state_lock);
 379         if ((cmd->transport_state & CMD_T_SENT) && !cmd->scsi_status)
 380                 cmd->se_cmd_flags |= SCF_COMPARE_AND_WRITE_POST;
 381         spin_unlock_irq(&cmd->t_state_lock);
 382
 383         /*
 384          * Unlock ->caw_sem originally obtained during sbc_compare_and_write()
 385          * before the original READ I/O submission.
 386          */
 387         up(&dev->caw_sem);
 388
 389         return TCM_NO_SENSE;
 390 }
 391
 392 static sense_reason_t compare_and_write_callback(struct se_cmd *cmd)
 393 {
 394         struct se_device *dev = cmd->se_dev;
 395         struct scatterlist *write_sg = NULL, *sg;
 396         unsigned char *buf = NULL, *addr;
 397         struct sg_mapping_iter m;
 398         unsigned int offset = 0, len;
 399         unsigned int nlbas = cmd->t_task_nolb;
 400         unsigned int block_size = dev->dev_attrib.block_size;
 401         unsigned int compare_len = (nlbas * block_size);
 402         sense_reason_t ret = TCM_NO_SENSE;
 403         int rc, i;
 404
 405         /*
 406          * Handle early failure in transport_generic_request_failure(),
 407          * which will not have taken ->caw_mutex yet..
 408          */
 409         if (!cmd->t_data_sg || !cmd->t_bidi_data_sg)
 410                 return TCM_NO_SENSE;
 411         /*
 412          * Immediately exit + release dev->caw_sem if command has already
 413          * been failed with a non-zero SCSI status.
 414          */
 415         if (cmd->scsi_status) {
 416                 pr_err("compare_and_write_callback: non zero scsi_status:"
 417                         " 0x%02x\n", cmd->scsi_status);
 418                 goto out;
 419         }
 420
 421         buf = kzalloc(cmd->data_length, GFP_KERNEL);
 422         if (!buf) {
 423                 pr_err("Unable to allocate compare_and_write buf\n");
 424                 ret = TCM_OUT_OF_RESOURCES;
 425                 goto out;
 426         }
 427
 428         write_sg = kzalloc(sizeof(struct scatterlist) * cmd->t_data_nents,
 429                            GFP_KERNEL);
 430         if (!write_sg) {
 431                 pr_err("Unable to allocate compare_and_write sg\n");
 432                 ret = TCM_OUT_OF_RESOURCES;
 433                 goto out;
 434         }
 435         /*
 436          * Setup verify and write data payloads from total NumberLBAs.
 437          */
 438         rc = sg_copy_to_buffer(cmd->t_data_sg, cmd->t_data_nents, buf,
 439                                cmd->data_length);
 440         if (!rc) {
 441                 pr_err("sg_copy_to_buffer() failed for compare_and_write\n");
 442                 ret = TCM_OUT_OF_RESOURCES;
 443                 goto out;
 444         }
 445         /*
 446          * Compare against SCSI READ payload against verify payload
 447          */
 448         for_each_sg(cmd->t_bidi_data_sg, sg, cmd->t_bidi_data_nents, i) {
 449                 addr = (unsigned char *)kmap_atomic(sg_page(sg));
 450                 if (!addr) {
 451                         ret = TCM_OUT_OF_RESOURCES;
 452                         goto out;
 453                 }
 454
 455                 len = min(sg->length, compare_len);
 456
 457                 if (memcmp(addr, buf + offset, len)) {
 458                         pr_warn("Detected MISCOMPARE for addr: %p buf: %p\n",
 459                                 addr, buf + offset);
 460                         kunmap_atomic(addr);
 461                         goto miscompare;
 462                 }
 463                 kunmap_atomic(addr);
 464
 465                 offset += len;
 466                 compare_len -= len;
 467                 if (!compare_len)
 468                         break;
 469         }
 470
 471         i = 0;
 472         len = cmd->t_task_nolb * block_size;
 473         sg_miter_start(&m, cmd->t_data_sg, cmd->t_data_nents, SG_MITER_TO_SG);
 474         /*
 475          * Currently assumes NoLB=1 and SGLs are PAGE_SIZE..
 476          */
 477         while (len) {
 478                 sg_miter_next(&m);
 479
 480                 if (block_size < PAGE_SIZE) {
 481                         sg_set_page(&write_sg[i], m.page, block_size,
 482                                     block_size);
 483                 } else {
 484                         sg_miter_next(&m);
 485                         sg_set_page(&write_sg[i], m.page, block_size,
 486                                     0);
 487                 }
 488                 len -= block_size;
 489                 i++;
 490         }
 491         sg_miter_stop(&m);
 492         /*
 493          * Save the original SGL + nents values before updating to new
 494          * assignments, to be released in transport_free_pages() ->
 495          * transport_reset_sgl_orig()
 496          */
 497         cmd->t_data_sg_orig = cmd->t_data_sg;
 498         cmd->t_data_sg = write_sg;
 499         cmd->t_data_nents_orig = cmd->t_data_nents;
 500         cmd->t_data_nents = 1;
 501
 502         cmd->sam_task_attr = MSG_HEAD_TAG;
 503         cmd->transport_complete_callback = compare_and_write_post;
 504         /*
 505          * Now reset ->execute_cmd() to the normal sbc_execute_rw() handler
 506          * for submitting the adjusted SGL to write instance user-data.
 507          */
 508         cmd->execute_cmd = sbc_execute_rw;
 509
 510         spin_lock_irq(&cmd->t_state_lock);
 511         cmd->t_state = TRANSPORT_PROCESSING;
 512         cmd->transport_state |= CMD_T_ACTIVE|CMD_T_BUSY|CMD_T_SENT;
 513         spin_unlock_irq(&cmd->t_state_lock);
 514
 515         __target_execute_cmd(cmd);
 516
 517         kfree(buf);
 518         return ret;
 519
 520 miscompare:
 521         pr_warn("Target/%s: Send MISCOMPARE check condition and sense\n",
 522                 dev->transport->name);
 523         ret = TCM_MISCOMPARE_VERIFY;
 524 out:
 525         /*
 526          * In the MISCOMPARE or failure case, unlock ->caw_sem obtained in
 527          * sbc_compare_and_write() before the original READ I/O submission.
 528          */
 529         up(&dev->caw_sem);
 530         kfree(write_sg);
 531         kfree(buf);
 532         return ret;
 533 }
 534
 535 static sense_reason_t
 536 sbc_compare_and_write(struct se_cmd *cmd)
 537 {
 538         struct se_device *dev = cmd->se_dev;
 539         sense_reason_t ret;
 540         int rc;
 541         /*
 542          * Submit the READ first for COMPARE_AND_WRITE to perform the
 543          * comparision using SGLs at cmd->t_bidi_data_sg..
 544          */
 545         rc = down_interruptible(&dev->caw_sem);
 546         if ((rc != 0) || signal_pending(current)) {
 547                 cmd->transport_complete_callback = NULL;
 548                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 549         }
 550         /*
 551          * Reset cmd->data_length to individual block_size in order to not
 552          * confuse backend drivers that depend on this value matching the
 553          * size of the I/O being submitted.
 554          */
 555         cmd->data_length = cmd->t_task_nolb * dev->dev_attrib.block_size;
 556
 557         ret = cmd->execute_rw(cmd, cmd->t_bidi_data_sg, cmd->t_bidi_data_nents,
 558                               DMA_FROM_DEVICE);
 559         if (ret) {
 560                 cmd->transport_complete_callback = NULL;
 561                 up(&dev->caw_sem);
 562                 return ret;
 563         }
 564         /*
 565          * Unlock of dev->caw_sem to occur in compare_and_write_callback()
 566          * upon MISCOMPARE, or in compare_and_write_done() upon completion
 567          * of WRITE instance user-data.
 568          */
 569         return TCM_NO_SENSE;
 570 }
 571
 572 static bool
 573 sbc_check_prot(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb,
 574                u32 sectors)
 575 {
 576         if (!cmd->t_prot_sg || !cmd->t_prot_nents)
 577                 return true;
 578
 579         switch (dev->dev_attrib.pi_prot_type) {
 580         case TARGET_DIF_TYPE3_PROT:
 581                 if (!(cdb[1] & 0xe0))
 582                         return true;
 583
 584                 cmd->reftag_seed = 0xffffffff;
 585                 break;
 586         case TARGET_DIF_TYPE2_PROT:
 587                 if (cdb[1] & 0xe0)
 588                         return false;
 589
 590                 cmd->reftag_seed = cmd->t_task_lba;
 591                 break;
 592         case TARGET_DIF_TYPE1_PROT:
 593                 if (!(cdb[1] & 0xe0))
 594                         return true;
 595
 596                 cmd->reftag_seed = cmd->t_task_lba;
 597                 break;
 598         case TARGET_DIF_TYPE0_PROT:
 599         default:
 600                 return true;
 601         }
 602
 603         cmd->prot_type = dev->dev_attrib.pi_prot_type;
 604         cmd->prot_length = dev->prot_length * sectors;
 605         cmd->prot_handover = PROT_SEPERATED;
 606
 607         return true;
 608 }
 609
 610 sense_reason_t
 611 sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
 612 {
 613         struct se_device *dev = cmd->se_dev;
 614         unsigned char *cdb = cmd->t_task_cdb;
 615         unsigned int size;
 616         u32 sectors = 0;
 617         sense_reason_t ret;
 618
 619         switch (cdb[0]) {
 620         case READ_6:
 621                 sectors = transport_get_sectors_6(cdb);
 622                 cmd->t_task_lba = transport_lba_21(cdb);
 623                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 624                 cmd->execute_rw = ops->execute_rw;
 625                 cmd->execute_cmd = sbc_execute_rw;
 626                 break;
 627         case READ_10:
 628                 sectors = transport_get_sectors_10(cdb);
 629                 cmd->t_task_lba = transport_lba_32(cdb);
 630
 631                 if (!sbc_check_prot(dev, cmd, cdb, sectors))
 632                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 633
 634                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 635                 cmd->execute_rw = ops->execute_rw;
 636                 cmd->execute_cmd = sbc_execute_rw;
 637                 break;
 638         case READ_12:
 639                 sectors = transport_get_sectors_12(cdb);
 640                 cmd->t_task_lba = transport_lba_32(cdb);
 641
 642                 if (!sbc_check_prot(dev, cmd, cdb, sectors))
 643                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 644
 645                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 646                 cmd->execute_rw = ops->execute_rw;
 647                 cmd->execute_cmd = sbc_execute_rw;
 648                 break;
 649         case READ_16:
 650                 sectors = transport_get_sectors_16(cdb);
 651                 cmd->t_task_lba = transport_lba_64(cdb);
 652
 653                 if (!sbc_check_prot(dev, cmd, cdb, sectors))
 654                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 655
 656                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 657                 cmd->execute_rw = ops->execute_rw;
 658                 cmd->execute_cmd = sbc_execute_rw;
 659                 break;
 660         case WRITE_6:
 661                 sectors = transport_get_sectors_6(cdb);
 662                 cmd->t_task_lba = transport_lba_21(cdb);
 663                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 664                 cmd->execute_rw = ops->execute_rw;
 665                 cmd->execute_cmd = sbc_execute_rw;
 666                 break;
 667         case WRITE_10:
 668         case WRITE_VERIFY:
 669                 sectors = transport_get_sectors_10(cdb);
 670                 cmd->t_task_lba = transport_lba_32(cdb);
 671
 672                 if (!sbc_check_prot(dev, cmd, cdb, sectors))
 673                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 674
 675                 if (cdb[1] & 0x8)
 676                         cmd->se_cmd_flags |= SCF_FUA;
 677                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 678                 cmd->execute_rw = ops->execute_rw;
 679                 cmd->execute_cmd = sbc_execute_rw;
 680                 break;
 681         case WRITE_12:
 682                 sectors = transport_get_sectors_12(cdb);
 683                 cmd->t_task_lba = transport_lba_32(cdb);
 684
 685                 if (!sbc_check_prot(dev, cmd, cdb, sectors))
 686                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 687
 688                 if (cdb[1] & 0x8)
 689                         cmd->se_cmd_flags |= SCF_FUA;
 690                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 691                 cmd->execute_rw = ops->execute_rw;
 692                 cmd->execute_cmd = sbc_execute_rw;
 693                 break;
 694         case WRITE_16:
 695                 sectors = transport_get_sectors_16(cdb);
 696                 cmd->t_task_lba = transport_lba_64(cdb);
 697
 698                 if (!sbc_check_prot(dev, cmd, cdb, sectors))
 699                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 700
 701                 if (cdb[1] & 0x8)
 702                         cmd->se_cmd_flags |= SCF_FUA;
 703                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 704                 cmd->execute_rw = ops->execute_rw;
 705                 cmd->execute_cmd = sbc_execute_rw;
 706                 break;
 707         case XDWRITEREAD_10:
 708                 if (cmd->data_direction != DMA_TO_DEVICE ||
 709                     !(cmd->se_cmd_flags & SCF_BIDI))
 710                         return TCM_INVALID_CDB_FIELD;
 711                 sectors = transport_get_sectors_10(cdb);
 712
 713                 cmd->t_task_lba = transport_lba_32(cdb);
 714                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 715
 716                 /*
 717                  * Setup BIDI XOR callback to be run after I/O completion.
 718                  */
 719                 cmd->execute_rw = ops->execute_rw;
 720                 cmd->execute_cmd = sbc_execute_rw;
 721                 cmd->transport_complete_callback = &xdreadwrite_callback;
 722                 if (cdb[1] & 0x8)
 723                         cmd->se_cmd_flags |= SCF_FUA;
 724                 break;
 725         case VARIABLE_LENGTH_CMD:
 726         {
 727                 u16 service_action = get_unaligned_be16(&cdb[8]);
 728                 switch (service_action) {
 729                 case XDWRITEREAD_32:
 730                         sectors = transport_get_sectors_32(cdb);
 731
 732                         /*
 733                          * Use WRITE_32 and READ_32 opcodes for the emulated
 734                          * XDWRITE_READ_32 logic.
 735                          */
 736                         cmd->t_task_lba = transport_lba_64_ext(cdb);
 737                         cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 738
 739                         /*
 740                          * Setup BIDI XOR callback to be run during after I/O
 741                          * completion.
 742                          */
 743                         cmd->execute_rw = ops->execute_rw;
 744                         cmd->execute_cmd = sbc_execute_rw;
 745                         cmd->transport_complete_callback = &xdreadwrite_callback;
 746                         if (cdb[1] & 0x8)
 747                                 cmd->se_cmd_flags |= SCF_FUA;
 748                         break;
 749                 case WRITE_SAME_32:
 750                         sectors = transport_get_sectors_32(cdb);
 751                         if (!sectors) {
 752                                 pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not"
 753                                        " supported\n");
 754                                 return TCM_INVALID_CDB_FIELD;
 755                         }
 756
 757                         size = sbc_get_size(cmd, 1);
 758                         cmd->t_task_lba = get_unaligned_be64(&cdb[12]);
 759
 760                         ret = sbc_setup_write_same(cmd, &cdb[10], ops);
 761                         if (ret)
 762                                 return ret;
 763                         break;
 764                 default:
 765                         pr_err("VARIABLE_LENGTH_CMD service action"
 766                                 " 0x%04x not supported\n", service_action);
 767                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 768                 }
 769                 break;
 770         }
 771         case COMPARE_AND_WRITE:
 772                 sectors = cdb[13];
 773                 /*
 774                  * Currently enforce COMPARE_AND_WRITE for a single sector
 775                  */
 776                 if (sectors > 1) {
 777                         pr_err("COMPARE_AND_WRITE contains NoLB: %u greater"
 778                                " than 1\n", sectors);
 779                         return TCM_INVALID_CDB_FIELD;
 780                 }
 781                 /*
 782                  * Double size because we have two buffers, note that
 783                  * zero is not an error..
 784                  */
 785                 size = 2 * sbc_get_size(cmd, sectors);
 786                 cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
 787                 cmd->t_task_nolb = sectors;
 788                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB | SCF_COMPARE_AND_WRITE;
 789                 cmd->execute_rw = ops->execute_rw;
 790                 cmd->execute_cmd = sbc_compare_and_write;
 791                 cmd->transport_complete_callback = compare_and_write_callback;
 792                 break;
 793         case READ_CAPACITY:
 794                 size = READ_CAP_LEN;
 795                 cmd->execute_cmd = sbc_emulate_readcapacity;
 796                 break;
 797         case SERVICE_ACTION_IN:
 798                 switch (cmd->t_task_cdb[1] & 0x1f) {
 799                 case SAI_READ_CAPACITY_16:
 800                         cmd->execute_cmd = sbc_emulate_readcapacity_16;
 801                         break;
 802                 case SAI_REPORT_REFERRALS:
 803                         cmd->execute_cmd = target_emulate_report_referrals;
 804                         break;
 805                 default:
 806                         pr_err("Unsupported SA: 0x%02x\n",
 807                                 cmd->t_task_cdb[1] & 0x1f);
 808                         return TCM_INVALID_CDB_FIELD;
 809                 }
 810                 size = (cdb[10] << 24) | (cdb[11] << 16) |
 811                        (cdb[12] << 8) | cdb[13];
 812                 break;
 813         case SYNCHRONIZE_CACHE:
 814         case SYNCHRONIZE_CACHE_16:
 815                 if (!ops->execute_sync_cache) {
 816                         size = 0;
 817                         cmd->execute_cmd = sbc_emulate_noop;
 818                         break;
 819                 }
 820
 821                 /*
 822                  * Extract LBA and range to be flushed for emulated SYNCHRONIZE_CACHE
 823                  */
 824                 if (cdb[0] == SYNCHRONIZE_CACHE) {
 825                         sectors = transport_get_sectors_10(cdb);
 826                         cmd->t_task_lba = transport_lba_32(cdb);
 827                 } else {
 828                         sectors = transport_get_sectors_16(cdb);
 829                         cmd->t_task_lba = transport_lba_64(cdb);
 830                 }
 831
 832                 size = sbc_get_size(cmd, sectors);
 833
 834                 /*
 835                  * Check to ensure that LBA + Range does not exceed past end of
 836                  * device for IBLOCK and FILEIO ->do_sync_cache() backend calls
 837                  */
 838                 if (cmd->t_task_lba || sectors) {
 839                         if (sbc_check_valid_sectors(cmd) < 0)
 840                                 return TCM_ADDRESS_OUT_OF_RANGE;
 841                 }
 842                 cmd->execute_cmd = ops->execute_sync_cache;
 843                 break;
 844         case UNMAP:
 845                 if (!ops->execute_unmap)
 846                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 847
 848                 size = get_unaligned_be16(&cdb[7]);
 849                 cmd->execute_cmd = ops->execute_unmap;
 850                 break;
 851         case WRITE_SAME_16:
 852                 sectors = transport_get_sectors_16(cdb);
 853                 if (!sectors) {
 854                         pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
 855                         return TCM_INVALID_CDB_FIELD;
 856                 }
 857
 858                 size = sbc_get_size(cmd, 1);
 859                 cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
 860
 861                 ret = sbc_setup_write_same(cmd, &cdb[1], ops);
 862                 if (ret)
 863                         return ret;
 864                 break;
 865         case WRITE_SAME:
 866                 sectors = transport_get_sectors_10(cdb);
 867                 if (!sectors) {
 868                         pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
 869                         return TCM_INVALID_CDB_FIELD;
 870                 }
 871
 872                 size = sbc_get_size(cmd, 1);
 873                 cmd->t_task_lba = get_unaligned_be32(&cdb[2]);
 874
 875                 /*
 876                  * Follow sbcr26 with WRITE_SAME (10) and check for the existence
 877                  * of byte 1 bit 3 UNMAP instead of original reserved field
 878                  */
 879                 ret = sbc_setup_write_same(cmd, &cdb[1], ops);
 880                 if (ret)
 881                         return ret;
 882                 break;
 883         case VERIFY:
 884                 size = 0;
 885                 cmd->execute_cmd = sbc_emulate_noop;
 886                 break;
 887         case REZERO_UNIT:
 888         case SEEK_6:
 889         case SEEK_10:
 890                 /*
 891                  * There are still clients out there which use these old SCSI-2
 892                  * commands. This mainly happens when running VMs with legacy
 893                  * guest systems, connected via SCSI command pass-through to
 894                  * iSCSI targets. Make them happy and return status GOOD.
 895                  */
 896                 size = 0;
 897                 cmd->execute_cmd = sbc_emulate_noop;
 898                 break;
 899         default:
 900                 ret = spc_parse_cdb(cmd, &size);
 901                 if (ret)
 902                         return ret;
 903         }
 904
 905         /* reject any command that we don't have a handler for */
 906         if (!(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) && !cmd->execute_cmd)
 907                 return TCM_UNSUPPORTED_SCSI_OPCODE;
 908
 909         if (cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
 910                 unsigned long long end_lba;
 911
 912                 if (sectors > dev->dev_attrib.fabric_max_sectors) {
 913                         printk_ratelimited(KERN_ERR "SCSI OP %02xh with too"
 914                                 " big sectors %u exceeds fabric_max_sectors:"
 915                                 " %u\n", cdb[0], sectors,
 916                                 dev->dev_attrib.fabric_max_sectors);
 917                         return TCM_INVALID_CDB_FIELD;
 918                 }
 919                 if (sectors > dev->dev_attrib.hw_max_sectors) {
 920                         printk_ratelimited(KERN_ERR "SCSI OP %02xh with too"
 921                                 " big sectors %u exceeds backend hw_max_sectors:"
 922                                 " %u\n", cdb[0], sectors,
 923                                 dev->dev_attrib.hw_max_sectors);
 924                         return TCM_INVALID_CDB_FIELD;
 925                 }
 926
 927                 end_lba = dev->transport->get_blocks(dev) + 1;
 928                 if (cmd->t_task_lba + sectors > end_lba) {
 929                         pr_err("cmd exceeds last lba %llu "
 930                                 "(lba %llu, sectors %u)\n",
 931                                 end_lba, cmd->t_task_lba, sectors);
 932                         return TCM_ADDRESS_OUT_OF_RANGE;
 933                 }
 934
 935                 if (!(cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE))
 936                         size = sbc_get_size(cmd, sectors);
 937         }
 938
 939         return target_cmd_size_check(cmd, size);
 940 }
 941 EXPORT_SYMBOL(sbc_parse_cdb);
 942
 943 u32 sbc_get_device_type(struct se_device *dev)
 944 {
 945         return TYPE_DISK;
 946 }
 947 EXPORT_SYMBOL(sbc_get_device_type);
 948
 949 sense_reason_t
 950 sbc_execute_unmap(struct se_cmd *cmd,
 951         sense_reason_t (*do_unmap_fn)(struct se_cmd *, void *,
 952                                       sector_t, sector_t),
 953         void *priv)
 954 {
 955         struct se_device *dev = cmd->se_dev;
 956         unsigned char *buf, *ptr = NULL;
 957         sector_t lba;
 958         int size;
 959         u32 range;
 960         sense_reason_t ret = 0;
 961         int dl, bd_dl;
 962
 963         /* We never set ANC_SUP */
 964         if (cmd->t_task_cdb[1])
 965                 return TCM_INVALID_CDB_FIELD;
 966
 967         if (cmd->data_length == 0) {
 968                 target_complete_cmd(cmd, SAM_STAT_GOOD);
 969                 return 0;
 970         }
 971
 972         if (cmd->data_length < 8) {
 973                 pr_warn("UNMAP parameter list length %u too small\n",
 974                         cmd->data_length);
 975                 return TCM_PARAMETER_LIST_LENGTH_ERROR;
 976         }
 977
 978         buf = transport_kmap_data_sg(cmd);
 979         if (!buf)
 980                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 981
 982         dl = get_unaligned_be16(&buf[0]);
 983         bd_dl = get_unaligned_be16(&buf[2]);
 984
 985         size = cmd->data_length - 8;
 986         if (bd_dl > size)
 987                 pr_warn("UNMAP parameter list length %u too small, ignoring bd_dl %u\n",
 988                         cmd->data_length, bd_dl);
 989         else
 990                 size = bd_dl;
 991
 992         if (size / 16 > dev->dev_attrib.max_unmap_block_desc_count) {
 993                 ret = TCM_INVALID_PARAMETER_LIST;
 994                 goto err;
 995         }
 996
 997         /* First UNMAP block descriptor starts at 8 byte offset */
 998         ptr = &buf[8];
 999         pr_debug("UNMAP: Sub: %s Using dl: %u bd_dl: %u size: %u"
1000                 " ptr: %p\n", dev->transport->name, dl, bd_dl, size, ptr);
1001
1002         while (size >= 16) {
1003                 lba = get_unaligned_be64(&ptr[0]);
1004                 range = get_unaligned_be32(&ptr[8]);
1005                 pr_debug("UNMAP: Using lba: %llu and range: %u\n",
1006                                  (unsigned long long)lba, range);
1007
1008                 if (range > dev->dev_attrib.max_unmap_lba_count) {
1009                         ret = TCM_INVALID_PARAMETER_LIST;
1010                         goto err;
1011                 }
1012
1013                 if (lba + range > dev->transport->get_blocks(dev) + 1) {
1014                         ret = TCM_ADDRESS_OUT_OF_RANGE;
1015                         goto err;
1016                 }
1017
1018                 ret = do_unmap_fn(cmd, priv, lba, range);
1019                 if (ret)
1020                         goto err;
1021
1022                 ptr += 16;
1023                 size -= 16;
1024         }
1025
1026 err:
1027         transport_kunmap_data_sg(cmd);
1028         if (!ret)
1029                 target_complete_cmd(cmd, GOOD);
1030         return ret;
1031 }
1032 EXPORT_SYMBOL(sbc_execute_unmap);
1033
1034 static sense_reason_t
1035 sbc_dif_v1_verify(struct se_device *dev, struct se_dif_v1_tuple *sdt,
1036                   const void *p, sector_t sector, unsigned int ei_lba)
1037 {
1038         int block_size = dev->dev_attrib.block_size;
1039         __be16 csum;
1040
1041         csum = cpu_to_be16(crc_t10dif(p, block_size));
1042
1043         if (sdt->guard_tag != csum) {
1044                 pr_err("DIFv1 checksum failed on sector %llu guard tag 0x%04x"
1045                         " csum 0x%04x\n", (unsigned long long)sector,
1046                         be16_to_cpu(sdt->guard_tag), be16_to_cpu(csum));
1047                 return TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED;
1048         }
1049
1050         if (dev->dev_attrib.pi_prot_type == TARGET_DIF_TYPE1_PROT &&
1051             be32_to_cpu(sdt->ref_tag) != (sector & 0xffffffff)) {
1052                 pr_err("DIFv1 Type 1 reference failed on sector: %llu tag: 0x%08x"
1053                        " sector MSB: 0x%08x\n", (unsigned long long)sector,
1054                        be32_to_cpu(sdt->ref_tag), (u32)(sector & 0xffffffff));
1055                 return TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;
1056         }
1057
1058         if (dev->dev_attrib.pi_prot_type == TARGET_DIF_TYPE2_PROT &&
1059             be32_to_cpu(sdt->ref_tag) != ei_lba) {
1060                 pr_err("DIFv1 Type 2 reference failed on sector: %llu tag: 0x%08x"
1061                        " ei_lba: 0x%08x\n", (unsigned long long)sector,
1062                         be32_to_cpu(sdt->ref_tag), ei_lba);
1063                 return TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;
1064         }
1065
1066         return 0;
1067 }
1068
1069 static void
1070 sbc_dif_copy_prot(struct se_cmd *cmd, unsigned int sectors, bool read,
1071                   struct scatterlist *sg, int sg_off)
1072 {
1073         struct se_device *dev = cmd->se_dev;
1074         struct scatterlist *psg;
1075         void *paddr, *addr;
1076         unsigned int i, len, left;
1077
1078         left = sectors * dev->prot_length;
1079
1080         for_each_sg(cmd->t_prot_sg, psg, cmd->t_prot_nents, i) {
1081
1082                 len = min(psg->length, left);
1083                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1084                 addr = kmap_atomic(sg_page(sg)) + sg_off;
1085
1086                 if (read)
1087                         memcpy(paddr, addr, len);
1088                 else
1089                         memcpy(addr, paddr, len);
1090
1091                 left -= len;
1092                 kunmap_atomic(paddr);
1093                 kunmap_atomic(addr);
1094         }
1095 }
1096
1097 sense_reason_t
1098 sbc_dif_verify_write(struct se_cmd *cmd, sector_t start, unsigned int sectors,
1099                      unsigned int ei_lba, struct scatterlist *sg, int sg_off)
1100 {
1101         struct se_device *dev = cmd->se_dev;
1102         struct se_dif_v1_tuple *sdt;
1103         struct scatterlist *dsg, *psg = cmd->t_prot_sg;
1104         sector_t sector = start;
1105         void *daddr, *paddr;
1106         int i, j, offset = 0;
1107         sense_reason_t rc;
1108
1109         for_each_sg(cmd->t_data_sg, dsg, cmd->t_data_nents, i) {
1110                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1111                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1112
1113                 for (j = 0; j < dsg->length; j += dev->dev_attrib.block_size) {
1114
1115                         if (offset >= psg->length) {
1116                                 kunmap_atomic(paddr);
1117                                 psg = sg_next(psg);
1118                                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1119                                 offset = 0;
1120                         }
1121
1122                         sdt = paddr + offset;
1123
1124                         pr_debug("DIF WRITE sector: %llu guard_tag: 0x%04x"
1125                                  " app_tag: 0x%04x ref_tag: %u\n",
1126                                  (unsigned long long)sector, sdt->guard_tag,
1127                                  sdt->app_tag, be32_to_cpu(sdt->ref_tag));
1128
1129                         rc = sbc_dif_v1_verify(dev, sdt, daddr + j, sector,
1130                                                ei_lba);
1131                         if (rc) {
1132                                 kunmap_atomic(paddr);
1133                                 kunmap_atomic(daddr);
1134                                 cmd->bad_sector = sector;
1135                                 return rc;
1136                         }
1137
1138                         sector++;
1139                         ei_lba++;
1140                         offset += sizeof(struct se_dif_v1_tuple);
1141                 }
1142
1143                 kunmap_atomic(paddr);
1144                 kunmap_atomic(daddr);
1145         }
1146         sbc_dif_copy_prot(cmd, sectors, false, sg, sg_off);
1147
1148         return 0;
1149 }
1150 EXPORT_SYMBOL(sbc_dif_verify_write);
1151
1152 sense_reason_t
1153 sbc_dif_verify_read(struct se_cmd *cmd, sector_t start, unsigned int sectors,
1154                     unsigned int ei_lba, struct scatterlist *sg, int sg_off)
1155 {
1156         struct se_device *dev = cmd->se_dev;
1157         struct se_dif_v1_tuple *sdt;
1158         struct scatterlist *dsg;
1159         sector_t sector = start;
1160         void *daddr, *paddr;
1161         int i, j, offset = sg_off;
1162         sense_reason_t rc;
1163
1164         for_each_sg(cmd->t_data_sg, dsg, cmd->t_data_nents, i) {
1165                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1166                 paddr = kmap_atomic(sg_page(sg)) + sg->offset;
1167
1168                 for (j = 0; j < dsg->length; j += dev->dev_attrib.block_size) {
1169
1170                         if (offset >= sg->length) {
1171                                 kunmap_atomic(paddr);
1172                                 sg = sg_next(sg);
1173                                 paddr = kmap_atomic(sg_page(sg)) + sg->offset;
1174                                 offset = 0;
1175                         }
1176
1177                         sdt = paddr + offset;
1178
1179                         pr_debug("DIF READ sector: %llu guard_tag: 0x%04x"
1180                                  " app_tag: 0x%04x ref_tag: %u\n",
1181                                  (unsigned long long)sector, sdt->guard_tag,
1182                                  sdt->app_tag, be32_to_cpu(sdt->ref_tag));
1183
1184                         if (sdt->app_tag == cpu_to_be16(0xffff)) {
1185                                 sector++;
1186                                 offset += sizeof(struct se_dif_v1_tuple);
1187                                 continue;
1188                         }
1189
1190                         rc = sbc_dif_v1_verify(dev, sdt, daddr + j, sector,
1191                                                ei_lba);
1192                         if (rc) {
1193                                 kunmap_atomic(paddr);
1194                                 kunmap_atomic(daddr);
1195                                 cmd->bad_sector = sector;
1196                                 return rc;
1197                         }
1198
1199                         sector++;
1200                         ei_lba++;
1201                         offset += sizeof(struct se_dif_v1_tuple);
1202                 }
1203
1204                 kunmap_atomic(paddr);
1205                 kunmap_atomic(daddr);
1206         }
1207         sbc_dif_copy_prot(cmd, sectors, true, sg, sg_off);
1208
1209         return 0;
1210 }
1211 EXPORT_SYMBOL(sbc_dif_verify_read);