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_proto.h>
  29 #include <scsi/scsi_tcq.h>
  30
  31 #include <target/target_core_base.h>
  32 #include <target/target_core_backend.h>
  33 #include <target/target_core_fabric.h>
  34
  35 #include "target_core_internal.h"
  36 #include "target_core_ua.h"
  37 #include "target_core_alua.h"
  38
  39 static sense_reason_t
  40 sbc_check_prot(struct se_device *, struct se_cmd *, unsigned char *, u32, bool);
  41 static sense_reason_t sbc_execute_unmap(struct se_cmd *cmd);
  42
  43 static sense_reason_t
  44 sbc_emulate_readcapacity(struct se_cmd *cmd)
  45 {
  46         struct se_device *dev = cmd->se_dev;
  47         unsigned char *cdb = cmd->t_task_cdb;
  48         unsigned long long blocks_long = dev->transport->get_blocks(dev);
  49         unsigned char *rbuf;
  50         unsigned char buf[8];
  51         u32 blocks;
  52
  53         /*
  54          * SBC-2 says:
  55          *   If the PMI bit is set to zero and the LOGICAL BLOCK
  56          *   ADDRESS field is not set to zero, the device server shall
  57          *   terminate the command with CHECK CONDITION status with
  58          *   the sense key set to ILLEGAL REQUEST and the additional
  59          *   sense code set to INVALID FIELD IN CDB.
  60          *
  61          * In SBC-3, these fields are obsolete, but some SCSI
  62          * compliance tests actually check this, so we might as well
  63          * follow SBC-2.
  64          */
  65         if (!(cdb[8] & 1) && !!(cdb[2] | cdb[3] | cdb[4] | cdb[5]))
  66                 return TCM_INVALID_CDB_FIELD;
  67
  68         if (blocks_long >= 0x00000000ffffffff)
  69                 blocks = 0xffffffff;
  70         else
  71                 blocks = (u32)blocks_long;
  72
  73         buf[0] = (blocks >> 24) & 0xff;
  74         buf[1] = (blocks >> 16) & 0xff;
  75         buf[2] = (blocks >> 8) & 0xff;
  76         buf[3] = blocks & 0xff;
  77         buf[4] = (dev->dev_attrib.block_size >> 24) & 0xff;
  78         buf[5] = (dev->dev_attrib.block_size >> 16) & 0xff;
  79         buf[6] = (dev->dev_attrib.block_size >> 8) & 0xff;
  80         buf[7] = dev->dev_attrib.block_size & 0xff;
  81
  82         rbuf = transport_kmap_data_sg(cmd);
  83         if (rbuf) {
  84                 memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length));
  85                 transport_kunmap_data_sg(cmd);
  86         }
  87
  88         target_complete_cmd_with_length(cmd, GOOD, 8);
  89         return 0;
  90 }
  91
  92 static sense_reason_t
  93 sbc_emulate_readcapacity_16(struct se_cmd *cmd)
  94 {
  95         struct se_device *dev = cmd->se_dev;
  96         struct se_session *sess = cmd->se_sess;
  97         int pi_prot_type = dev->dev_attrib.pi_prot_type;
  98
  99         unsigned char *rbuf;
 100         unsigned char buf[32];
 101         unsigned long long blocks = dev->transport->get_blocks(dev);
 102
 103         memset(buf, 0, sizeof(buf));
 104         buf[0] = (blocks >> 56) & 0xff;
 105         buf[1] = (blocks >> 48) & 0xff;
 106         buf[2] = (blocks >> 40) & 0xff;
 107         buf[3] = (blocks >> 32) & 0xff;
 108         buf[4] = (blocks >> 24) & 0xff;
 109         buf[5] = (blocks >> 16) & 0xff;
 110         buf[6] = (blocks >> 8) & 0xff;
 111         buf[7] = blocks & 0xff;
 112         buf[8] = (dev->dev_attrib.block_size >> 24) & 0xff;
 113         buf[9] = (dev->dev_attrib.block_size >> 16) & 0xff;
 114         buf[10] = (dev->dev_attrib.block_size >> 8) & 0xff;
 115         buf[11] = dev->dev_attrib.block_size & 0xff;
 116         /*
 117          * Set P_TYPE and PROT_EN bits for DIF support
 118          */
 119         if (sess->sup_prot_ops & (TARGET_PROT_DIN_PASS | TARGET_PROT_DOUT_PASS)) {
 120                 /*
 121                  * Only override a device's pi_prot_type if no T10-PI is
 122                  * available, and sess_prot_type has been explicitly enabled.
 123                  */
 124                 if (!pi_prot_type)
 125                         pi_prot_type = sess->sess_prot_type;
 126
 127                 if (pi_prot_type)
 128                         buf[12] = (pi_prot_type - 1) << 1 | 0x1;
 129         }
 130
 131         if (dev->transport->get_lbppbe)
 132                 buf[13] = dev->transport->get_lbppbe(dev) & 0x0f;
 133
 134         if (dev->transport->get_alignment_offset_lbas) {
 135                 u16 lalba = dev->transport->get_alignment_offset_lbas(dev);
 136                 buf[14] = (lalba >> 8) & 0x3f;
 137                 buf[15] = lalba & 0xff;
 138         }
 139
 140         /*
 141          * Set Thin Provisioning Enable bit following sbc3r22 in section
 142          * READ CAPACITY (16) byte 14 if emulate_tpu or emulate_tpws is enabled.
 143          */
 144         if (dev->dev_attrib.emulate_tpu || dev->dev_attrib.emulate_tpws)
 145                 buf[14] |= 0x80;
 146
 147         rbuf = transport_kmap_data_sg(cmd);
 148         if (rbuf) {
 149                 memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length));
 150                 transport_kunmap_data_sg(cmd);
 151         }
 152
 153         target_complete_cmd_with_length(cmd, GOOD, 32);
 154         return 0;
 155 }
 156
 157 static sense_reason_t
 158 sbc_emulate_startstop(struct se_cmd *cmd)
 159 {
 160         unsigned char *cdb = cmd->t_task_cdb;
 161
 162         /*
 163          * See sbc3r36 section 5.25
 164          * Immediate bit should be set since there is nothing to complete
 165          * POWER CONDITION MODIFIER 0h
 166          */
 167         if (!(cdb[1] & 1) || cdb[2] || cdb[3])
 168                 return TCM_INVALID_CDB_FIELD;
 169
 170         /*
 171          * See sbc3r36 section 5.25
 172          * POWER CONDITION 0h START_VALID - process START and LOEJ
 173          */
 174         if (cdb[4] >> 4 & 0xf)
 175                 return TCM_INVALID_CDB_FIELD;
 176
 177         /*
 178          * See sbc3r36 section 5.25
 179          * LOEJ 0h - nothing to load or unload
 180          * START 1h - we are ready
 181          */
 182         if (!(cdb[4] & 1) || (cdb[4] & 2) || (cdb[4] & 4))
 183                 return TCM_INVALID_CDB_FIELD;
 184
 185         target_complete_cmd(cmd, SAM_STAT_GOOD);
 186         return 0;
 187 }
 188
 189 sector_t sbc_get_write_same_sectors(struct se_cmd *cmd)
 190 {
 191         u32 num_blocks;
 192
 193         if (cmd->t_task_cdb[0] == WRITE_SAME)
 194                 num_blocks = get_unaligned_be16(&cmd->t_task_cdb[7]);
 195         else if (cmd->t_task_cdb[0] == WRITE_SAME_16)
 196                 num_blocks = get_unaligned_be32(&cmd->t_task_cdb[10]);
 197         else /* WRITE_SAME_32 via VARIABLE_LENGTH_CMD */
 198                 num_blocks = get_unaligned_be32(&cmd->t_task_cdb[28]);
 199
 200         /*
 201          * Use the explicit range when non zero is supplied, otherwise calculate
 202          * the remaining range based on ->get_blocks() - starting LBA.
 203          */
 204         if (num_blocks)
 205                 return num_blocks;
 206
 207         return cmd->se_dev->transport->get_blocks(cmd->se_dev) -
 208                 cmd->t_task_lba + 1;
 209 }
 210 EXPORT_SYMBOL(sbc_get_write_same_sectors);
 211
 212 static sense_reason_t
 213 sbc_execute_write_same_unmap(struct se_cmd *cmd)
 214 {
 215         struct sbc_ops *ops = cmd->protocol_data;
 216         sector_t nolb = sbc_get_write_same_sectors(cmd);
 217         sense_reason_t ret;
 218
 219         if (nolb) {
 220                 ret = ops->execute_unmap(cmd, cmd->t_task_lba, nolb);
 221                 if (ret)
 222                         return ret;
 223         }
 224
 225         target_complete_cmd(cmd, GOOD);
 226         return 0;
 227 }
 228
 229 static sense_reason_t
 230 sbc_emulate_noop(struct se_cmd *cmd)
 231 {
 232         target_complete_cmd(cmd, GOOD);
 233         return 0;
 234 }
 235
 236 static inline u32 sbc_get_size(struct se_cmd *cmd, u32 sectors)
 237 {
 238         return cmd->se_dev->dev_attrib.block_size * sectors;
 239 }
 240
 241 static inline u32 transport_get_sectors_6(unsigned char *cdb)
 242 {
 243         /*
 244          * Use 8-bit sector value.  SBC-3 says:
 245          *
 246          *   A TRANSFER LENGTH field set to zero specifies that 256
 247          *   logical blocks shall be written.  Any other value
 248          *   specifies the number of logical blocks that shall be
 249          *   written.
 250          */
 251         return cdb[4] ? : 256;
 252 }
 253
 254 static inline u32 transport_get_sectors_10(unsigned char *cdb)
 255 {
 256         return (u32)(cdb[7] << 8) + cdb[8];
 257 }
 258
 259 static inline u32 transport_get_sectors_12(unsigned char *cdb)
 260 {
 261         return (u32)(cdb[6] << 24) + (cdb[7] << 16) + (cdb[8] << 8) + cdb[9];
 262 }
 263
 264 static inline u32 transport_get_sectors_16(unsigned char *cdb)
 265 {
 266         return (u32)(cdb[10] << 24) + (cdb[11] << 16) +
 267                     (cdb[12] << 8) + cdb[13];
 268 }
 269
 270 /*
 271  * Used for VARIABLE_LENGTH_CDB WRITE_32 and READ_32 variants
 272  */
 273 static inline u32 transport_get_sectors_32(unsigned char *cdb)
 274 {
 275         return (u32)(cdb[28] << 24) + (cdb[29] << 16) +
 276                     (cdb[30] << 8) + cdb[31];
 277
 278 }
 279
 280 static inline u32 transport_lba_21(unsigned char *cdb)
 281 {
 282         return ((cdb[1] & 0x1f) << 16) | (cdb[2] << 8) | cdb[3];
 283 }
 284
 285 static inline u32 transport_lba_32(unsigned char *cdb)
 286 {
 287         return (cdb[2] << 24) | (cdb[3] << 16) | (cdb[4] << 8) | cdb[5];
 288 }
 289
 290 static inline unsigned long long transport_lba_64(unsigned char *cdb)
 291 {
 292         unsigned int __v1, __v2;
 293
 294         __v1 = (cdb[2] << 24) | (cdb[3] << 16) | (cdb[4] << 8) | cdb[5];
 295         __v2 = (cdb[6] << 24) | (cdb[7] << 16) | (cdb[8] << 8) | cdb[9];
 296
 297         return ((unsigned long long)__v2) | (unsigned long long)__v1 << 32;
 298 }
 299
 300 /*
 301  * For VARIABLE_LENGTH_CDB w/ 32 byte extended CDBs
 302  */
 303 static inline unsigned long long transport_lba_64_ext(unsigned char *cdb)
 304 {
 305         unsigned int __v1, __v2;
 306
 307         __v1 = (cdb[12] << 24) | (cdb[13] << 16) | (cdb[14] << 8) | cdb[15];
 308         __v2 = (cdb[16] << 24) | (cdb[17] << 16) | (cdb[18] << 8) | cdb[19];
 309
 310         return ((unsigned long long)__v2) | (unsigned long long)__v1 << 32;
 311 }
 312
 313 static sense_reason_t
 314 sbc_setup_write_same(struct se_cmd *cmd, unsigned char *flags, struct sbc_ops *ops)
 315 {
 316         struct se_device *dev = cmd->se_dev;
 317         sector_t end_lba = dev->transport->get_blocks(dev) + 1;
 318         unsigned int sectors = sbc_get_write_same_sectors(cmd);
 319         sense_reason_t ret;
 320
 321         if ((flags[0] & 0x04) || (flags[0] & 0x02)) {
 322                 pr_err("WRITE_SAME PBDATA and LBDATA"
 323                         " bits not supported for Block Discard"
 324                         " Emulation\n");
 325                 return TCM_UNSUPPORTED_SCSI_OPCODE;
 326         }
 327         if (sectors > cmd->se_dev->dev_attrib.max_write_same_len) {
 328                 pr_warn("WRITE_SAME sectors: %u exceeds max_write_same_len: %u\n",
 329                         sectors, cmd->se_dev->dev_attrib.max_write_same_len);
 330                 return TCM_INVALID_CDB_FIELD;
 331         }
 332         /*
 333          * Sanity check for LBA wrap and request past end of device.
 334          */
 335         if (((cmd->t_task_lba + sectors) < cmd->t_task_lba) ||
 336             ((cmd->t_task_lba + sectors) > end_lba)) {
 337                 pr_err("WRITE_SAME exceeds last lba %llu (lba %llu, sectors %u)\n",
 338                        (unsigned long long)end_lba, cmd->t_task_lba, sectors);
 339                 return TCM_ADDRESS_OUT_OF_RANGE;
 340         }
 341
 342         /* We always have ANC_SUP == 0 so setting ANCHOR is always an error */
 343         if (flags[0] & 0x10) {
 344                 pr_warn("WRITE SAME with ANCHOR not supported\n");
 345                 return TCM_INVALID_CDB_FIELD;
 346         }
 347         /*
 348          * Special case for WRITE_SAME w/ UNMAP=1 that ends up getting
 349          * translated into block discard requests within backend code.
 350          */
 351         if (flags[0] & 0x08) {
 352                 if (!ops->execute_unmap)
 353                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 354
 355                 if (!dev->dev_attrib.emulate_tpws) {
 356                         pr_err("Got WRITE_SAME w/ UNMAP=1, but backend device"
 357                                " has emulate_tpws disabled\n");
 358                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 359                 }
 360                 cmd->execute_cmd = sbc_execute_write_same_unmap;
 361                 return 0;
 362         }
 363         if (!ops->execute_write_same)
 364                 return TCM_UNSUPPORTED_SCSI_OPCODE;
 365
 366         ret = sbc_check_prot(dev, cmd, &cmd->t_task_cdb[0], sectors, true);
 367         if (ret)
 368                 return ret;
 369
 370         cmd->execute_cmd = ops->execute_write_same;
 371         return 0;
 372 }
 373
 374 static sense_reason_t xdreadwrite_callback(struct se_cmd *cmd, bool success,
 375                                            int *post_ret)
 376 {
 377         unsigned char *buf, *addr;
 378         struct scatterlist *sg;
 379         unsigned int offset;
 380         sense_reason_t ret = TCM_NO_SENSE;
 381         int i, count;
 382         /*
 383          * From sbc3r22.pdf section 5.48 XDWRITEREAD (10) command
 384          *
 385          * 1) read the specified logical block(s);
 386          * 2) transfer logical blocks from the data-out buffer;
 387          * 3) XOR the logical blocks transferred from the data-out buffer with
 388          *    the logical blocks read, storing the resulting XOR data in a buffer;
 389          * 4) if the DISABLE WRITE bit is set to zero, then write the logical
 390          *    blocks transferred from the data-out buffer; and
 391          * 5) transfer the resulting XOR data to the data-in buffer.
 392          */
 393         buf = kmalloc(cmd->data_length, GFP_KERNEL);
 394         if (!buf) {
 395                 pr_err("Unable to allocate xor_callback buf\n");
 396                 return TCM_OUT_OF_RESOURCES;
 397         }
 398         /*
 399          * Copy the scatterlist WRITE buffer located at cmd->t_data_sg
 400          * into the locally allocated *buf
 401          */
 402         sg_copy_to_buffer(cmd->t_data_sg,
 403                           cmd->t_data_nents,
 404                           buf,
 405                           cmd->data_length);
 406
 407         /*
 408          * Now perform the XOR against the BIDI read memory located at
 409          * cmd->t_mem_bidi_list
 410          */
 411
 412         offset = 0;
 413         for_each_sg(cmd->t_bidi_data_sg, sg, cmd->t_bidi_data_nents, count) {
 414                 addr = kmap_atomic(sg_page(sg));
 415                 if (!addr) {
 416                         ret = TCM_OUT_OF_RESOURCES;
 417                         goto out;
 418                 }
 419
 420                 for (i = 0; i < sg->length; i++)
 421                         *(addr + sg->offset + i) ^= *(buf + offset + i);
 422
 423                 offset += sg->length;
 424                 kunmap_atomic(addr);
 425         }
 426
 427 out:
 428         kfree(buf);
 429         return ret;
 430 }
 431
 432 static sense_reason_t
 433 sbc_execute_rw(struct se_cmd *cmd)
 434 {
 435         struct sbc_ops *ops = cmd->protocol_data;
 436
 437         return ops->execute_rw(cmd, cmd->t_data_sg, cmd->t_data_nents,
 438                                cmd->data_direction);
 439 }
 440
 441 static sense_reason_t compare_and_write_post(struct se_cmd *cmd, bool success,
 442                                              int *post_ret)
 443 {
 444         struct se_device *dev = cmd->se_dev;
 445         sense_reason_t ret = TCM_NO_SENSE;
 446
 447         /*
 448          * Only set SCF_COMPARE_AND_WRITE_POST to force a response fall-through
 449          * within target_complete_ok_work() if the command was successfully
 450          * sent to the backend driver.
 451          */
 452         spin_lock_irq(&cmd->t_state_lock);
 453         if (cmd->transport_state & CMD_T_SENT) {
 454                 cmd->se_cmd_flags |= SCF_COMPARE_AND_WRITE_POST;
 455                 *post_ret = 1;
 456
 457                 if (cmd->scsi_status == SAM_STAT_CHECK_CONDITION)
 458                         ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 459         }
 460         spin_unlock_irq(&cmd->t_state_lock);
 461
 462         /*
 463          * Unlock ->caw_sem originally obtained during sbc_compare_and_write()
 464          * before the original READ I/O submission.
 465          */
 466         up(&dev->caw_sem);
 467
 468         return ret;
 469 }
 470
 471 static sense_reason_t compare_and_write_callback(struct se_cmd *cmd, bool success,
 472                                                  int *post_ret)
 473 {
 474         struct se_device *dev = cmd->se_dev;
 475         struct scatterlist *write_sg = NULL, *sg;
 476         unsigned char *buf = NULL, *addr;
 477         struct sg_mapping_iter m;
 478         unsigned int offset = 0, len;
 479         unsigned int nlbas = cmd->t_task_nolb;
 480         unsigned int block_size = dev->dev_attrib.block_size;
 481         unsigned int compare_len = (nlbas * block_size);
 482         sense_reason_t ret = TCM_NO_SENSE;
 483         int rc, i;
 484
 485         /*
 486          * Handle early failure in transport_generic_request_failure(),
 487          * which will not have taken ->caw_sem yet..
 488          */
 489         if (!success && (!cmd->t_data_sg || !cmd->t_bidi_data_sg))
 490                 return TCM_NO_SENSE;
 491         /*
 492          * Handle special case for zero-length COMPARE_AND_WRITE
 493          */
 494         if (!cmd->data_length)
 495                 goto out;
 496         /*
 497          * Immediately exit + release dev->caw_sem if command has already
 498          * been failed with a non-zero SCSI status.
 499          */
 500         if (cmd->scsi_status) {
 501                 pr_debug("compare_and_write_callback: non zero scsi_status:"
 502                         " 0x%02x\n", cmd->scsi_status);
 503                 *post_ret = 1;
 504                 if (cmd->scsi_status == SAM_STAT_CHECK_CONDITION)
 505                         ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 506                 goto out;
 507         }
 508
 509         buf = kzalloc(cmd->data_length, GFP_KERNEL);
 510         if (!buf) {
 511                 pr_err("Unable to allocate compare_and_write buf\n");
 512                 ret = TCM_OUT_OF_RESOURCES;
 513                 goto out;
 514         }
 515
 516         write_sg = kmalloc(sizeof(struct scatterlist) * cmd->t_data_nents,
 517                            GFP_KERNEL);
 518         if (!write_sg) {
 519                 pr_err("Unable to allocate compare_and_write sg\n");
 520                 ret = TCM_OUT_OF_RESOURCES;
 521                 goto out;
 522         }
 523         sg_init_table(write_sg, cmd->t_data_nents);
 524         /*
 525          * Setup verify and write data payloads from total NumberLBAs.
 526          */
 527         rc = sg_copy_to_buffer(cmd->t_data_sg, cmd->t_data_nents, buf,
 528                                cmd->data_length);
 529         if (!rc) {
 530                 pr_err("sg_copy_to_buffer() failed for compare_and_write\n");
 531                 ret = TCM_OUT_OF_RESOURCES;
 532                 goto out;
 533         }
 534         /*
 535          * Compare against SCSI READ payload against verify payload
 536          */
 537         for_each_sg(cmd->t_bidi_data_sg, sg, cmd->t_bidi_data_nents, i) {
 538                 addr = (unsigned char *)kmap_atomic(sg_page(sg));
 539                 if (!addr) {
 540                         ret = TCM_OUT_OF_RESOURCES;
 541                         goto out;
 542                 }
 543
 544                 len = min(sg->length, compare_len);
 545
 546                 if (memcmp(addr, buf + offset, len)) {
 547                         pr_warn("Detected MISCOMPARE for addr: %p buf: %p\n",
 548                                 addr, buf + offset);
 549                         kunmap_atomic(addr);
 550                         goto miscompare;
 551                 }
 552                 kunmap_atomic(addr);
 553
 554                 offset += len;
 555                 compare_len -= len;
 556                 if (!compare_len)
 557                         break;
 558         }
 559
 560         i = 0;
 561         len = cmd->t_task_nolb * block_size;
 562         sg_miter_start(&m, cmd->t_data_sg, cmd->t_data_nents, SG_MITER_TO_SG);
 563         /*
 564          * Currently assumes NoLB=1 and SGLs are PAGE_SIZE..
 565          */
 566         while (len) {
 567                 sg_miter_next(&m);
 568
 569                 if (block_size < PAGE_SIZE) {
 570                         sg_set_page(&write_sg[i], m.page, block_size,
 571                                     m.piter.sg->offset + block_size);
 572                 } else {
 573                         sg_miter_next(&m);
 574                         sg_set_page(&write_sg[i], m.page, block_size,
 575                                     m.piter.sg->offset);
 576                 }
 577                 len -= block_size;
 578                 i++;
 579         }
 580         sg_miter_stop(&m);
 581         /*
 582          * Save the original SGL + nents values before updating to new
 583          * assignments, to be released in transport_free_pages() ->
 584          * transport_reset_sgl_orig()
 585          */
 586         cmd->t_data_sg_orig = cmd->t_data_sg;
 587         cmd->t_data_sg = write_sg;
 588         cmd->t_data_nents_orig = cmd->t_data_nents;
 589         cmd->t_data_nents = 1;
 590
 591         cmd->sam_task_attr = TCM_HEAD_TAG;
 592         cmd->transport_complete_callback = compare_and_write_post;
 593         /*
 594          * Now reset ->execute_cmd() to the normal sbc_execute_rw() handler
 595          * for submitting the adjusted SGL to write instance user-data.
 596          */
 597         cmd->execute_cmd = sbc_execute_rw;
 598
 599         spin_lock_irq(&cmd->t_state_lock);
 600         cmd->t_state = TRANSPORT_PROCESSING;
 601         cmd->transport_state |= CMD_T_ACTIVE|CMD_T_BUSY|CMD_T_SENT;
 602         spin_unlock_irq(&cmd->t_state_lock);
 603
 604         __target_execute_cmd(cmd, false);
 605
 606         kfree(buf);
 607         return ret;
 608
 609 miscompare:
 610         pr_warn("Target/%s: Send MISCOMPARE check condition and sense\n",
 611                 dev->transport->name);
 612         ret = TCM_MISCOMPARE_VERIFY;
 613 out:
 614         /*
 615          * In the MISCOMPARE or failure case, unlock ->caw_sem obtained in
 616          * sbc_compare_and_write() before the original READ I/O submission.
 617          */
 618         up(&dev->caw_sem);
 619         kfree(write_sg);
 620         kfree(buf);
 621         return ret;
 622 }
 623
 624 static sense_reason_t
 625 sbc_compare_and_write(struct se_cmd *cmd)
 626 {
 627         struct sbc_ops *ops = cmd->protocol_data;
 628         struct se_device *dev = cmd->se_dev;
 629         sense_reason_t ret;
 630         int rc;
 631         /*
 632          * Submit the READ first for COMPARE_AND_WRITE to perform the
 633          * comparision using SGLs at cmd->t_bidi_data_sg..
 634          */
 635         rc = down_interruptible(&dev->caw_sem);
 636         if (rc != 0) {
 637                 cmd->transport_complete_callback = NULL;
 638                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 639         }
 640         /*
 641          * Reset cmd->data_length to individual block_size in order to not
 642          * confuse backend drivers that depend on this value matching the
 643          * size of the I/O being submitted.
 644          */
 645         cmd->data_length = cmd->t_task_nolb * dev->dev_attrib.block_size;
 646
 647         ret = ops->execute_rw(cmd, cmd->t_bidi_data_sg, cmd->t_bidi_data_nents,
 648                               DMA_FROM_DEVICE);
 649         if (ret) {
 650                 cmd->transport_complete_callback = NULL;
 651                 up(&dev->caw_sem);
 652                 return ret;
 653         }
 654         /*
 655          * Unlock of dev->caw_sem to occur in compare_and_write_callback()
 656          * upon MISCOMPARE, or in compare_and_write_done() upon completion
 657          * of WRITE instance user-data.
 658          */
 659         return TCM_NO_SENSE;
 660 }
 661
 662 static int
 663 sbc_set_prot_op_checks(u8 protect, bool fabric_prot, enum target_prot_type prot_type,
 664                        bool is_write, struct se_cmd *cmd)
 665 {
 666         if (is_write) {
 667                 cmd->prot_op = fabric_prot ? TARGET_PROT_DOUT_STRIP :
 668                                protect ? TARGET_PROT_DOUT_PASS :
 669                                TARGET_PROT_DOUT_INSERT;
 670                 switch (protect) {
 671                 case 0x0:
 672                 case 0x3:
 673                         cmd->prot_checks = 0;
 674                         break;
 675                 case 0x1:
 676                 case 0x5:
 677                         cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
 678                         if (prot_type == TARGET_DIF_TYPE1_PROT)
 679                                 cmd->prot_checks |= TARGET_DIF_CHECK_REFTAG;
 680                         break;
 681                 case 0x2:
 682                         if (prot_type == TARGET_DIF_TYPE1_PROT)
 683                                 cmd->prot_checks = TARGET_DIF_CHECK_REFTAG;
 684                         break;
 685                 case 0x4:
 686                         cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
 687                         break;
 688                 default:
 689                         pr_err("Unsupported protect field %d\n", protect);
 690                         return -EINVAL;
 691                 }
 692         } else {
 693                 cmd->prot_op = fabric_prot ? TARGET_PROT_DIN_INSERT :
 694                                protect ? TARGET_PROT_DIN_PASS :
 695                                TARGET_PROT_DIN_STRIP;
 696                 switch (protect) {
 697                 case 0x0:
 698                 case 0x1:
 699                 case 0x5:
 700                         cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
 701                         if (prot_type == TARGET_DIF_TYPE1_PROT)
 702                                 cmd->prot_checks |= TARGET_DIF_CHECK_REFTAG;
 703                         break;
 704                 case 0x2:
 705                         if (prot_type == TARGET_DIF_TYPE1_PROT)
 706                                 cmd->prot_checks = TARGET_DIF_CHECK_REFTAG;
 707                         break;
 708                 case 0x3:
 709                         cmd->prot_checks = 0;
 710                         break;
 711                 case 0x4:
 712                         cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
 713                         break;
 714                 default:
 715                         pr_err("Unsupported protect field %d\n", protect);
 716                         return -EINVAL;
 717                 }
 718         }
 719
 720         return 0;
 721 }
 722
 723 static sense_reason_t
 724 sbc_check_prot(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb,
 725                u32 sectors, bool is_write)
 726 {
 727         u8 protect = cdb[1] >> 5;
 728         int sp_ops = cmd->se_sess->sup_prot_ops;
 729         int pi_prot_type = dev->dev_attrib.pi_prot_type;
 730         bool fabric_prot = false;
 731
 732         if (!cmd->t_prot_sg || !cmd->t_prot_nents) {
 733                 if (unlikely(protect &&
 734                     !dev->dev_attrib.pi_prot_type && !cmd->se_sess->sess_prot_type)) {
 735                         pr_err("CDB contains protect bit, but device + fabric does"
 736                                " not advertise PROTECT=1 feature bit\n");
 737                         return TCM_INVALID_CDB_FIELD;
 738                 }
 739                 if (cmd->prot_pto)
 740                         return TCM_NO_SENSE;
 741         }
 742
 743         switch (dev->dev_attrib.pi_prot_type) {
 744         case TARGET_DIF_TYPE3_PROT:
 745                 cmd->reftag_seed = 0xffffffff;
 746                 break;
 747         case TARGET_DIF_TYPE2_PROT:
 748                 if (protect)
 749                         return TCM_INVALID_CDB_FIELD;
 750
 751                 cmd->reftag_seed = cmd->t_task_lba;
 752                 break;
 753         case TARGET_DIF_TYPE1_PROT:
 754                 cmd->reftag_seed = cmd->t_task_lba;
 755                 break;
 756         case TARGET_DIF_TYPE0_PROT:
 757                 /*
 758                  * See if the fabric supports T10-PI, and the session has been
 759                  * configured to allow export PROTECT=1 feature bit with backend
 760                  * devices that don't support T10-PI.
 761                  */
 762                 fabric_prot = is_write ?
 763                               !!(sp_ops & (TARGET_PROT_DOUT_PASS | TARGET_PROT_DOUT_STRIP)) :
 764                               !!(sp_ops & (TARGET_PROT_DIN_PASS | TARGET_PROT_DIN_INSERT));
 765
 766                 if (fabric_prot && cmd->se_sess->sess_prot_type) {
 767                         pi_prot_type = cmd->se_sess->sess_prot_type;
 768                         break;
 769                 }
 770                 if (!protect)
 771                         return TCM_NO_SENSE;
 772                 /* Fallthrough */
 773         default:
 774                 pr_err("Unable to determine pi_prot_type for CDB: 0x%02x "
 775                        "PROTECT: 0x%02x\n", cdb[0], protect);
 776                 return TCM_INVALID_CDB_FIELD;
 777         }
 778
 779         if (sbc_set_prot_op_checks(protect, fabric_prot, pi_prot_type, is_write, cmd))
 780                 return TCM_INVALID_CDB_FIELD;
 781
 782         cmd->prot_type = pi_prot_type;
 783         cmd->prot_length = dev->prot_length * sectors;
 784
 785         /**
 786          * In case protection information exists over the wire
 787          * we modify command data length to describe pure data.
 788          * The actual transfer length is data length + protection
 789          * length
 790          **/
 791         if (protect)
 792                 cmd->data_length = sectors * dev->dev_attrib.block_size;
 793
 794         pr_debug("%s: prot_type=%d, data_length=%d, prot_length=%d "
 795                  "prot_op=%d prot_checks=%d\n",
 796                  __func__, cmd->prot_type, cmd->data_length, cmd->prot_length,
 797                  cmd->prot_op, cmd->prot_checks);
 798
 799         return TCM_NO_SENSE;
 800 }
 801
 802 static int
 803 sbc_check_dpofua(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb)
 804 {
 805         if (cdb[1] & 0x10) {
 806                 /* see explanation in spc_emulate_modesense */
 807                 if (!target_check_fua(dev)) {
 808                         pr_err("Got CDB: 0x%02x with DPO bit set, but device"
 809                                " does not advertise support for DPO\n", cdb[0]);
 810                         return -EINVAL;
 811                 }
 812         }
 813         if (cdb[1] & 0x8) {
 814                 if (!target_check_fua(dev)) {
 815                         pr_err("Got CDB: 0x%02x with FUA bit set, but device"
 816                                " does not advertise support for FUA write\n",
 817                                cdb[0]);
 818                         return -EINVAL;
 819                 }
 820                 cmd->se_cmd_flags |= SCF_FUA;
 821         }
 822         return 0;
 823 }
 824
 825 sense_reason_t
 826 sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
 827 {
 828         struct se_device *dev = cmd->se_dev;
 829         unsigned char *cdb = cmd->t_task_cdb;
 830         unsigned int size;
 831         u32 sectors = 0;
 832         sense_reason_t ret;
 833
 834         cmd->protocol_data = ops;
 835
 836         switch (cdb[0]) {
 837         case READ_6:
 838                 sectors = transport_get_sectors_6(cdb);
 839                 cmd->t_task_lba = transport_lba_21(cdb);
 840                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 841                 cmd->execute_cmd = sbc_execute_rw;
 842                 break;
 843         case READ_10:
 844                 sectors = transport_get_sectors_10(cdb);
 845                 cmd->t_task_lba = transport_lba_32(cdb);
 846
 847                 if (sbc_check_dpofua(dev, cmd, cdb))
 848                         return TCM_INVALID_CDB_FIELD;
 849
 850                 ret = sbc_check_prot(dev, cmd, cdb, sectors, false);
 851                 if (ret)
 852                         return ret;
 853
 854                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 855                 cmd->execute_cmd = sbc_execute_rw;
 856                 break;
 857         case READ_12:
 858                 sectors = transport_get_sectors_12(cdb);
 859                 cmd->t_task_lba = transport_lba_32(cdb);
 860
 861                 if (sbc_check_dpofua(dev, cmd, cdb))
 862                         return TCM_INVALID_CDB_FIELD;
 863
 864                 ret = sbc_check_prot(dev, cmd, cdb, sectors, false);
 865                 if (ret)
 866                         return ret;
 867
 868                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 869                 cmd->execute_cmd = sbc_execute_rw;
 870                 break;
 871         case READ_16:
 872                 sectors = transport_get_sectors_16(cdb);
 873                 cmd->t_task_lba = transport_lba_64(cdb);
 874
 875                 if (sbc_check_dpofua(dev, cmd, cdb))
 876                         return TCM_INVALID_CDB_FIELD;
 877
 878                 ret = sbc_check_prot(dev, cmd, cdb, sectors, false);
 879                 if (ret)
 880                         return ret;
 881
 882                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 883                 cmd->execute_cmd = sbc_execute_rw;
 884                 break;
 885         case WRITE_6:
 886                 sectors = transport_get_sectors_6(cdb);
 887                 cmd->t_task_lba = transport_lba_21(cdb);
 888                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 889                 cmd->execute_cmd = sbc_execute_rw;
 890                 break;
 891         case WRITE_10:
 892         case WRITE_VERIFY:
 893                 sectors = transport_get_sectors_10(cdb);
 894                 cmd->t_task_lba = transport_lba_32(cdb);
 895
 896                 if (sbc_check_dpofua(dev, cmd, cdb))
 897                         return TCM_INVALID_CDB_FIELD;
 898
 899                 ret = sbc_check_prot(dev, cmd, cdb, sectors, true);
 900                 if (ret)
 901                         return ret;
 902
 903                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 904                 cmd->execute_cmd = sbc_execute_rw;
 905                 break;
 906         case WRITE_12:
 907                 sectors = transport_get_sectors_12(cdb);
 908                 cmd->t_task_lba = transport_lba_32(cdb);
 909
 910                 if (sbc_check_dpofua(dev, cmd, cdb))
 911                         return TCM_INVALID_CDB_FIELD;
 912
 913                 ret = sbc_check_prot(dev, cmd, cdb, sectors, true);
 914                 if (ret)
 915                         return ret;
 916
 917                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 918                 cmd->execute_cmd = sbc_execute_rw;
 919                 break;
 920         case WRITE_16:
 921                 sectors = transport_get_sectors_16(cdb);
 922                 cmd->t_task_lba = transport_lba_64(cdb);
 923
 924                 if (sbc_check_dpofua(dev, cmd, cdb))
 925                         return TCM_INVALID_CDB_FIELD;
 926
 927                 ret = sbc_check_prot(dev, cmd, cdb, sectors, true);
 928                 if (ret)
 929                         return ret;
 930
 931                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 932                 cmd->execute_cmd = sbc_execute_rw;
 933                 break;
 934         case XDWRITEREAD_10:
 935                 if (cmd->data_direction != DMA_TO_DEVICE ||
 936                     !(cmd->se_cmd_flags & SCF_BIDI))
 937                         return TCM_INVALID_CDB_FIELD;
 938                 sectors = transport_get_sectors_10(cdb);
 939
 940                 if (sbc_check_dpofua(dev, cmd, cdb))
 941                         return TCM_INVALID_CDB_FIELD;
 942
 943                 cmd->t_task_lba = transport_lba_32(cdb);
 944                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 945
 946                 /*
 947                  * Setup BIDI XOR callback to be run after I/O completion.
 948                  */
 949                 cmd->execute_cmd = sbc_execute_rw;
 950                 cmd->transport_complete_callback = &xdreadwrite_callback;
 951                 break;
 952         case VARIABLE_LENGTH_CMD:
 953         {
 954                 u16 service_action = get_unaligned_be16(&cdb[8]);
 955                 switch (service_action) {
 956                 case XDWRITEREAD_32:
 957                         sectors = transport_get_sectors_32(cdb);
 958
 959                         if (sbc_check_dpofua(dev, cmd, cdb))
 960                                 return TCM_INVALID_CDB_FIELD;
 961                         /*
 962                          * Use WRITE_32 and READ_32 opcodes for the emulated
 963                          * XDWRITE_READ_32 logic.
 964                          */
 965                         cmd->t_task_lba = transport_lba_64_ext(cdb);
 966                         cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 967
 968                         /*
 969                          * Setup BIDI XOR callback to be run during after I/O
 970                          * completion.
 971                          */
 972                         cmd->execute_cmd = sbc_execute_rw;
 973                         cmd->transport_complete_callback = &xdreadwrite_callback;
 974                         break;
 975                 case WRITE_SAME_32:
 976                         sectors = transport_get_sectors_32(cdb);
 977                         if (!sectors) {
 978                                 pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not"
 979                                        " supported\n");
 980                                 return TCM_INVALID_CDB_FIELD;
 981                         }
 982
 983                         size = sbc_get_size(cmd, 1);
 984                         cmd->t_task_lba = get_unaligned_be64(&cdb[12]);
 985
 986                         ret = sbc_setup_write_same(cmd, &cdb[10], ops);
 987                         if (ret)
 988                                 return ret;
 989                         break;
 990                 default:
 991                         pr_err("VARIABLE_LENGTH_CMD service action"
 992                                 " 0x%04x not supported\n", service_action);
 993                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 994                 }
 995                 break;
 996         }
 997         case COMPARE_AND_WRITE:
 998                 sectors = cdb[13];
 999                 /*
1000                  * Currently enforce COMPARE_AND_WRITE for a single sector
1001                  */
1002                 if (sectors > 1) {
1003                         pr_err("COMPARE_AND_WRITE contains NoLB: %u greater"
1004                                " than 1\n", sectors);
1005                         return TCM_INVALID_CDB_FIELD;
1006                 }
1007                 if (sbc_check_dpofua(dev, cmd, cdb))
1008                         return TCM_INVALID_CDB_FIELD;
1009
1010                 /*
1011                  * Double size because we have two buffers, note that
1012                  * zero is not an error..
1013                  */
1014                 size = 2 * sbc_get_size(cmd, sectors);
1015                 cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
1016                 cmd->t_task_nolb = sectors;
1017                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB | SCF_COMPARE_AND_WRITE;
1018                 cmd->execute_cmd = sbc_compare_and_write;
1019                 cmd->transport_complete_callback = compare_and_write_callback;
1020                 break;
1021         case READ_CAPACITY:
1022                 size = READ_CAP_LEN;
1023                 cmd->execute_cmd = sbc_emulate_readcapacity;
1024                 break;
1025         case SERVICE_ACTION_IN_16:
1026                 switch (cmd->t_task_cdb[1] & 0x1f) {
1027                 case SAI_READ_CAPACITY_16:
1028                         cmd->execute_cmd = sbc_emulate_readcapacity_16;
1029                         break;
1030                 case SAI_REPORT_REFERRALS:
1031                         cmd->execute_cmd = target_emulate_report_referrals;
1032                         break;
1033                 default:
1034                         pr_err("Unsupported SA: 0x%02x\n",
1035                                 cmd->t_task_cdb[1] & 0x1f);
1036                         return TCM_INVALID_CDB_FIELD;
1037                 }
1038                 size = (cdb[10] << 24) | (cdb[11] << 16) |
1039                        (cdb[12] << 8) | cdb[13];
1040                 break;
1041         case SYNCHRONIZE_CACHE:
1042         case SYNCHRONIZE_CACHE_16:
1043                 if (cdb[0] == SYNCHRONIZE_CACHE) {
1044                         sectors = transport_get_sectors_10(cdb);
1045                         cmd->t_task_lba = transport_lba_32(cdb);
1046                 } else {
1047                         sectors = transport_get_sectors_16(cdb);
1048                         cmd->t_task_lba = transport_lba_64(cdb);
1049                 }
1050                 if (ops->execute_sync_cache) {
1051                         cmd->execute_cmd = ops->execute_sync_cache;
1052                         goto check_lba;
1053                 }
1054                 size = 0;
1055                 cmd->execute_cmd = sbc_emulate_noop;
1056                 break;
1057         case UNMAP:
1058                 if (!ops->execute_unmap)
1059                         return TCM_UNSUPPORTED_SCSI_OPCODE;
1060
1061                 if (!dev->dev_attrib.emulate_tpu) {
1062                         pr_err("Got UNMAP, but backend device has"
1063                                " emulate_tpu disabled\n");
1064                         return TCM_UNSUPPORTED_SCSI_OPCODE;
1065                 }
1066                 size = get_unaligned_be16(&cdb[7]);
1067                 cmd->execute_cmd = sbc_execute_unmap;
1068                 break;
1069         case WRITE_SAME_16:
1070                 sectors = transport_get_sectors_16(cdb);
1071                 if (!sectors) {
1072                         pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
1073                         return TCM_INVALID_CDB_FIELD;
1074                 }
1075
1076                 size = sbc_get_size(cmd, 1);
1077                 cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
1078
1079                 ret = sbc_setup_write_same(cmd, &cdb[1], ops);
1080                 if (ret)
1081                         return ret;
1082                 break;
1083         case WRITE_SAME:
1084                 sectors = transport_get_sectors_10(cdb);
1085                 if (!sectors) {
1086                         pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
1087                         return TCM_INVALID_CDB_FIELD;
1088                 }
1089
1090                 size = sbc_get_size(cmd, 1);
1091                 cmd->t_task_lba = get_unaligned_be32(&cdb[2]);
1092
1093                 /*
1094                  * Follow sbcr26 with WRITE_SAME (10) and check for the existence
1095                  * of byte 1 bit 3 UNMAP instead of original reserved field
1096                  */
1097                 ret = sbc_setup_write_same(cmd, &cdb[1], ops);
1098                 if (ret)
1099                         return ret;
1100                 break;
1101         case VERIFY:
1102         case VERIFY_16:
1103                 size = 0;
1104                 if (cdb[0] == VERIFY) {
1105                         sectors = transport_get_sectors_10(cdb);
1106                         cmd->t_task_lba = transport_lba_32(cdb);
1107                 } else {
1108                         sectors = transport_get_sectors_16(cdb);
1109                         cmd->t_task_lba = transport_lba_64(cdb);
1110                 }
1111                 cmd->execute_cmd = sbc_emulate_noop;
1112                 goto check_lba;
1113         case REZERO_UNIT:
1114         case SEEK_6:
1115         case SEEK_10:
1116                 /*
1117                  * There are still clients out there which use these old SCSI-2
1118                  * commands. This mainly happens when running VMs with legacy
1119                  * guest systems, connected via SCSI command pass-through to
1120                  * iSCSI targets. Make them happy and return status GOOD.
1121                  */
1122                 size = 0;
1123                 cmd->execute_cmd = sbc_emulate_noop;
1124                 break;
1125         case START_STOP:
1126                 size = 0;
1127                 cmd->execute_cmd = sbc_emulate_startstop;
1128                 break;
1129         default:
1130                 ret = spc_parse_cdb(cmd, &size);
1131                 if (ret)
1132                         return ret;
1133         }
1134
1135         /* reject any command that we don't have a handler for */
1136         if (!cmd->execute_cmd)
1137                 return TCM_UNSUPPORTED_SCSI_OPCODE;
1138
1139         if (cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
1140                 unsigned long long end_lba;
1141 check_lba:
1142                 end_lba = dev->transport->get_blocks(dev) + 1;
1143                 if (((cmd->t_task_lba + sectors) < cmd->t_task_lba) ||
1144                     ((cmd->t_task_lba + sectors) > end_lba)) {
1145                         pr_err("cmd exceeds last lba %llu "
1146                                 "(lba %llu, sectors %u)\n",
1147                                 end_lba, cmd->t_task_lba, sectors);
1148                         return TCM_ADDRESS_OUT_OF_RANGE;
1149                 }
1150
1151                 if (!(cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE))
1152                         size = sbc_get_size(cmd, sectors);
1153         }
1154
1155         return target_cmd_size_check(cmd, size);
1156 }
1157 EXPORT_SYMBOL(sbc_parse_cdb);
1158
1159 u32 sbc_get_device_type(struct se_device *dev)
1160 {
1161         return TYPE_DISK;
1162 }
1163 EXPORT_SYMBOL(sbc_get_device_type);
1164
1165 static sense_reason_t
1166 sbc_execute_unmap(struct se_cmd *cmd)
1167 {
1168         struct sbc_ops *ops = cmd->protocol_data;
1169         struct se_device *dev = cmd->se_dev;
1170         unsigned char *buf, *ptr = NULL;
1171         sector_t lba;
1172         int size;
1173         u32 range;
1174         sense_reason_t ret = 0;
1175         int dl, bd_dl;
1176
1177         /* We never set ANC_SUP */
1178         if (cmd->t_task_cdb[1])
1179                 return TCM_INVALID_CDB_FIELD;
1180
1181         if (cmd->data_length == 0) {
1182                 target_complete_cmd(cmd, SAM_STAT_GOOD);
1183                 return 0;
1184         }
1185
1186         if (cmd->data_length < 8) {
1187                 pr_warn("UNMAP parameter list length %u too small\n",
1188                         cmd->data_length);
1189                 return TCM_PARAMETER_LIST_LENGTH_ERROR;
1190         }
1191
1192         buf = transport_kmap_data_sg(cmd);
1193         if (!buf)
1194                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1195
1196         dl = get_unaligned_be16(&buf[0]);
1197         bd_dl = get_unaligned_be16(&buf[2]);
1198
1199         size = cmd->data_length - 8;
1200         if (bd_dl > size)
1201                 pr_warn("UNMAP parameter list length %u too small, ignoring bd_dl %u\n",
1202                         cmd->data_length, bd_dl);
1203         else
1204                 size = bd_dl;
1205
1206         if (size / 16 > dev->dev_attrib.max_unmap_block_desc_count) {
1207                 ret = TCM_INVALID_PARAMETER_LIST;
1208                 goto err;
1209         }
1210
1211         /* First UNMAP block descriptor starts at 8 byte offset */
1212         ptr = &buf[8];
1213         pr_debug("UNMAP: Sub: %s Using dl: %u bd_dl: %u size: %u"
1214                 " ptr: %p\n", dev->transport->name, dl, bd_dl, size, ptr);
1215
1216         while (size >= 16) {
1217                 lba = get_unaligned_be64(&ptr[0]);
1218                 range = get_unaligned_be32(&ptr[8]);
1219                 pr_debug("UNMAP: Using lba: %llu and range: %u\n",
1220                                  (unsigned long long)lba, range);
1221
1222                 if (range > dev->dev_attrib.max_unmap_lba_count) {
1223                         ret = TCM_INVALID_PARAMETER_LIST;
1224                         goto err;
1225                 }
1226
1227                 if (lba + range > dev->transport->get_blocks(dev) + 1) {
1228                         ret = TCM_ADDRESS_OUT_OF_RANGE;
1229                         goto err;
1230                 }
1231
1232                 ret = ops->execute_unmap(cmd, lba, range);
1233                 if (ret)
1234                         goto err;
1235
1236                 ptr += 16;
1237                 size -= 16;
1238         }
1239
1240 err:
1241         transport_kunmap_data_sg(cmd);
1242         if (!ret)
1243                 target_complete_cmd(cmd, GOOD);
1244         return ret;
1245 }
1246
1247 void
1248 sbc_dif_generate(struct se_cmd *cmd)
1249 {
1250         struct se_device *dev = cmd->se_dev;
1251         struct t10_pi_tuple *sdt;
1252         struct scatterlist *dsg = cmd->t_data_sg, *psg;
1253         sector_t sector = cmd->t_task_lba;
1254         void *daddr, *paddr;
1255         int i, j, offset = 0;
1256         unsigned int block_size = dev->dev_attrib.block_size;
1257
1258         for_each_sg(cmd->t_prot_sg, psg, cmd->t_prot_nents, i) {
1259                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1260                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1261
1262                 for (j = 0; j < psg->length;
1263                                 j += sizeof(*sdt)) {
1264                         __u16 crc;
1265                         unsigned int avail;
1266
1267                         if (offset >= dsg->length) {
1268                                 offset -= dsg->length;
1269                                 kunmap_atomic(daddr - dsg->offset);
1270                                 dsg = sg_next(dsg);
1271                                 if (!dsg) {
1272                                         kunmap_atomic(paddr - psg->offset);
1273                                         return;
1274                                 }
1275                                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1276                         }
1277
1278                         sdt = paddr + j;
1279                         avail = min(block_size, dsg->length - offset);
1280                         crc = crc_t10dif(daddr + offset, avail);
1281                         if (avail < block_size) {
1282                                 kunmap_atomic(daddr - dsg->offset);
1283                                 dsg = sg_next(dsg);
1284                                 if (!dsg) {
1285                                         kunmap_atomic(paddr - psg->offset);
1286                                         return;
1287                                 }
1288                                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1289                                 offset = block_size - avail;
1290                                 crc = crc_t10dif_update(crc, daddr, offset);
1291                         } else {
1292                                 offset += block_size;
1293                         }
1294
1295                         sdt->guard_tag = cpu_to_be16(crc);
1296                         if (cmd->prot_type == TARGET_DIF_TYPE1_PROT)
1297                                 sdt->ref_tag = cpu_to_be32(sector & 0xffffffff);
1298                         sdt->app_tag = 0;
1299
1300                         pr_debug("DIF %s INSERT sector: %llu guard_tag: 0x%04x"
1301                                  " app_tag: 0x%04x ref_tag: %u\n",
1302                                  (cmd->data_direction == DMA_TO_DEVICE) ?
1303                                  "WRITE" : "READ", (unsigned long long)sector,
1304                                  sdt->guard_tag, sdt->app_tag,
1305                                  be32_to_cpu(sdt->ref_tag));
1306
1307                         sector++;
1308                 }
1309
1310                 kunmap_atomic(daddr - dsg->offset);
1311                 kunmap_atomic(paddr - psg->offset);
1312         }
1313 }
1314
1315 static sense_reason_t
1316 sbc_dif_v1_verify(struct se_cmd *cmd, struct t10_pi_tuple *sdt,
1317                   __u16 crc, sector_t sector, unsigned int ei_lba)
1318 {
1319         __be16 csum;
1320
1321         if (!(cmd->prot_checks & TARGET_DIF_CHECK_GUARD))
1322                 goto check_ref;
1323
1324         csum = cpu_to_be16(crc);
1325
1326         if (sdt->guard_tag != csum) {
1327                 pr_err("DIFv1 checksum failed on sector %llu guard tag 0x%04x"
1328                         " csum 0x%04x\n", (unsigned long long)sector,
1329                         be16_to_cpu(sdt->guard_tag), be16_to_cpu(csum));
1330                 return TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED;
1331         }
1332
1333 check_ref:
1334         if (!(cmd->prot_checks & TARGET_DIF_CHECK_REFTAG))
1335                 return 0;
1336
1337         if (cmd->prot_type == TARGET_DIF_TYPE1_PROT &&
1338             be32_to_cpu(sdt->ref_tag) != (sector & 0xffffffff)) {
1339                 pr_err("DIFv1 Type 1 reference failed on sector: %llu tag: 0x%08x"
1340                        " sector MSB: 0x%08x\n", (unsigned long long)sector,
1341                        be32_to_cpu(sdt->ref_tag), (u32)(sector & 0xffffffff));
1342                 return TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;
1343         }
1344
1345         if (cmd->prot_type == TARGET_DIF_TYPE2_PROT &&
1346             be32_to_cpu(sdt->ref_tag) != ei_lba) {
1347                 pr_err("DIFv1 Type 2 reference failed on sector: %llu tag: 0x%08x"
1348                        " ei_lba: 0x%08x\n", (unsigned long long)sector,
1349                         be32_to_cpu(sdt->ref_tag), ei_lba);
1350                 return TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;
1351         }
1352
1353         return 0;
1354 }
1355
1356 void sbc_dif_copy_prot(struct se_cmd *cmd, unsigned int sectors, bool read,
1357                        struct scatterlist *sg, int sg_off)
1358 {
1359         struct se_device *dev = cmd->se_dev;
1360         struct scatterlist *psg;
1361         void *paddr, *addr;
1362         unsigned int i, len, left;
1363         unsigned int offset = sg_off;
1364
1365         if (!sg)
1366                 return;
1367
1368         left = sectors * dev->prot_length;
1369
1370         for_each_sg(cmd->t_prot_sg, psg, cmd->t_prot_nents, i) {
1371                 unsigned int psg_len, copied = 0;
1372
1373                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1374                 psg_len = min(left, psg->length);
1375                 while (psg_len) {
1376                         len = min(psg_len, sg->length - offset);
1377                         addr = kmap_atomic(sg_page(sg)) + sg->offset + offset;
1378
1379                         if (read)
1380                                 memcpy(paddr + copied, addr, len);
1381                         else
1382                                 memcpy(addr, paddr + copied, len);
1383
1384                         left -= len;
1385                         offset += len;
1386                         copied += len;
1387                         psg_len -= len;
1388
1389                         kunmap_atomic(addr - sg->offset - offset);
1390
1391                         if (offset >= sg->length) {
1392                                 sg = sg_next(sg);
1393                                 offset = 0;
1394                         }
1395                 }
1396                 kunmap_atomic(paddr - psg->offset);
1397         }
1398 }
1399 EXPORT_SYMBOL(sbc_dif_copy_prot);
1400
1401 sense_reason_t
1402 sbc_dif_verify(struct se_cmd *cmd, sector_t start, unsigned int sectors,
1403                unsigned int ei_lba, struct scatterlist *psg, int psg_off)
1404 {
1405         struct se_device *dev = cmd->se_dev;
1406         struct t10_pi_tuple *sdt;
1407         struct scatterlist *dsg = cmd->t_data_sg;
1408         sector_t sector = start;
1409         void *daddr, *paddr;
1410         int i;
1411         sense_reason_t rc;
1412         int dsg_off = 0;
1413         unsigned int block_size = dev->dev_attrib.block_size;
1414
1415         for (; psg && sector < start + sectors; psg = sg_next(psg)) {
1416                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1417                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1418
1419                 for (i = psg_off; i < psg->length &&
1420                                 sector < start + sectors;
1421                                 i += sizeof(*sdt)) {
1422                         __u16 crc;
1423                         unsigned int avail;
1424
1425                         if (dsg_off >= dsg->length) {
1426                                 dsg_off -= dsg->length;
1427                                 kunmap_atomic(daddr - dsg->offset);
1428                                 dsg = sg_next(dsg);
1429                                 if (!dsg) {
1430                                         kunmap_atomic(paddr - psg->offset);
1431                                         return 0;
1432                                 }
1433                                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1434                         }
1435
1436                         sdt = paddr + i;
1437
1438                         pr_debug("DIF READ sector: %llu guard_tag: 0x%04x"
1439                                  " app_tag: 0x%04x ref_tag: %u\n",
1440                                  (unsigned long long)sector, sdt->guard_tag,
1441                                  sdt->app_tag, be32_to_cpu(sdt->ref_tag));
1442
1443                         if (sdt->app_tag == cpu_to_be16(0xffff)) {
1444                                 dsg_off += block_size;
1445                                 goto next;
1446                         }
1447
1448                         avail = min(block_size, dsg->length - dsg_off);
1449                         crc = crc_t10dif(daddr + dsg_off, avail);
1450                         if (avail < block_size) {
1451                                 kunmap_atomic(daddr - dsg->offset);
1452                                 dsg = sg_next(dsg);
1453                                 if (!dsg) {
1454                                         kunmap_atomic(paddr - psg->offset);
1455                                         return 0;
1456                                 }
1457                                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1458                                 dsg_off = block_size - avail;
1459                                 crc = crc_t10dif_update(crc, daddr, dsg_off);
1460                         } else {
1461                                 dsg_off += block_size;
1462                         }
1463
1464                         rc = sbc_dif_v1_verify(cmd, sdt, crc, sector, ei_lba);
1465                         if (rc) {
1466                                 kunmap_atomic(daddr - dsg->offset);
1467                                 kunmap_atomic(paddr - psg->offset);
1468                                 cmd->bad_sector = sector;
1469                                 return rc;
1470                         }
1471 next:
1472                         sector++;
1473                         ei_lba++;
1474                 }
1475
1476                 psg_off = 0;
1477                 kunmap_atomic(daddr - dsg->offset);
1478                 kunmap_atomic(paddr - psg->offset);
1479         }
1480
1481         return 0;
1482 }
1483 EXPORT_SYMBOL(sbc_dif_verify);