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