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 <asm/unaligned.h>
  27 #include <scsi/scsi.h>
  28 #include <scsi/scsi_tcq.h>
  29
  30 #include <target/target_core_base.h>
  31 #include <target/target_core_backend.h>
  32 #include <target/target_core_fabric.h>
  33
  34 #include "target_core_internal.h"
  35 #include "target_core_ua.h"
  36
  37
  38 static sense_reason_t
  39 sbc_emulate_readcapacity(struct se_cmd *cmd)
  40 {
  41         struct se_device *dev = cmd->se_dev;
  42         unsigned char *cdb = cmd->t_task_cdb;
  43         unsigned long long blocks_long = dev->transport->get_blocks(dev);
  44         unsigned char *rbuf;
  45         unsigned char buf[8];
  46         u32 blocks;
  47
  48         /*
  49          * SBC-2 says:
  50          *   If the PMI bit is set to zero and the LOGICAL BLOCK
  51          *   ADDRESS field is not set to zero, the device server shall
  52          *   terminate the command with CHECK CONDITION status with
  53          *   the sense key set to ILLEGAL REQUEST and the additional
  54          *   sense code set to INVALID FIELD IN CDB.
  55          *
  56          * In SBC-3, these fields are obsolete, but some SCSI
  57          * compliance tests actually check this, so we might as well
  58          * follow SBC-2.
  59          */
  60         if (!(cdb[8] & 1) && !!(cdb[2] | cdb[3] | cdb[4] | cdb[5]))
  61                 return TCM_INVALID_CDB_FIELD;
  62
  63         if (blocks_long >= 0x00000000ffffffff)
  64                 blocks = 0xffffffff;
  65         else
  66                 blocks = (u32)blocks_long;
  67
  68         buf[0] = (blocks >> 24) & 0xff;
  69         buf[1] = (blocks >> 16) & 0xff;
  70         buf[2] = (blocks >> 8) & 0xff;
  71         buf[3] = blocks & 0xff;
  72         buf[4] = (dev->dev_attrib.block_size >> 24) & 0xff;
  73         buf[5] = (dev->dev_attrib.block_size >> 16) & 0xff;
  74         buf[6] = (dev->dev_attrib.block_size >> 8) & 0xff;
  75         buf[7] = dev->dev_attrib.block_size & 0xff;
  76
  77         rbuf = transport_kmap_data_sg(cmd);
  78         if (rbuf) {
  79                 memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length));
  80                 transport_kunmap_data_sg(cmd);
  81         }
  82
  83         target_complete_cmd(cmd, GOOD);
  84         return 0;
  85 }
  86
  87 static sense_reason_t
  88 sbc_emulate_readcapacity_16(struct se_cmd *cmd)
  89 {
  90         struct se_device *dev = cmd->se_dev;
  91         unsigned char *rbuf;
  92         unsigned char buf[32];
  93         unsigned long long blocks = dev->transport->get_blocks(dev);
  94
  95         memset(buf, 0, sizeof(buf));
  96         buf[0] = (blocks >> 56) & 0xff;
  97         buf[1] = (blocks >> 48) & 0xff;
  98         buf[2] = (blocks >> 40) & 0xff;
  99         buf[3] = (blocks >> 32) & 0xff;
 100         buf[4] = (blocks >> 24) & 0xff;
 101         buf[5] = (blocks >> 16) & 0xff;
 102         buf[6] = (blocks >> 8) & 0xff;
 103         buf[7] = blocks & 0xff;
 104         buf[8] = (dev->dev_attrib.block_size >> 24) & 0xff;
 105         buf[9] = (dev->dev_attrib.block_size >> 16) & 0xff;
 106         buf[10] = (dev->dev_attrib.block_size >> 8) & 0xff;
 107         buf[11] = dev->dev_attrib.block_size & 0xff;
 108         /*
 109          * Set Thin Provisioning Enable bit following sbc3r22 in section
 110          * READ CAPACITY (16) byte 14 if emulate_tpu or emulate_tpws is enabled.
 111          */
 112         if (dev->dev_attrib.emulate_tpu || dev->dev_attrib.emulate_tpws)
 113                 buf[14] = 0x80;
 114
 115         rbuf = transport_kmap_data_sg(cmd);
 116         if (rbuf) {
 117                 memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length));
 118                 transport_kunmap_data_sg(cmd);
 119         }
 120
 121         target_complete_cmd(cmd, GOOD);
 122         return 0;
 123 }
 124
 125 sector_t sbc_get_write_same_sectors(struct se_cmd *cmd)
 126 {
 127         u32 num_blocks;
 128
 129         if (cmd->t_task_cdb[0] == WRITE_SAME)
 130                 num_blocks = get_unaligned_be16(&cmd->t_task_cdb[7]);
 131         else if (cmd->t_task_cdb[0] == WRITE_SAME_16)
 132                 num_blocks = get_unaligned_be32(&cmd->t_task_cdb[10]);
 133         else /* WRITE_SAME_32 via VARIABLE_LENGTH_CMD */
 134                 num_blocks = get_unaligned_be32(&cmd->t_task_cdb[28]);
 135
 136         /*
 137          * Use the explicit range when non zero is supplied, otherwise calculate
 138          * the remaining range based on ->get_blocks() - starting LBA.
 139          */
 140         if (num_blocks)
 141                 return num_blocks;
 142
 143         return cmd->se_dev->transport->get_blocks(cmd->se_dev) -
 144                 cmd->t_task_lba + 1;
 145 }
 146 EXPORT_SYMBOL(sbc_get_write_same_sectors);
 147
 148 static sense_reason_t
 149 sbc_emulate_noop(struct se_cmd *cmd)
 150 {
 151         target_complete_cmd(cmd, GOOD);
 152         return 0;
 153 }
 154
 155 static inline u32 sbc_get_size(struct se_cmd *cmd, u32 sectors)
 156 {
 157         return cmd->se_dev->dev_attrib.block_size * sectors;
 158 }
 159
 160 static int sbc_check_valid_sectors(struct se_cmd *cmd)
 161 {
 162         struct se_device *dev = cmd->se_dev;
 163         unsigned long long end_lba;
 164         u32 sectors;
 165
 166         sectors = cmd->data_length / dev->dev_attrib.block_size;
 167         end_lba = dev->transport->get_blocks(dev) + 1;
 168
 169         if (cmd->t_task_lba + sectors > end_lba) {
 170                 pr_err("target: lba %llu, sectors %u exceeds end lba %llu\n",
 171                         cmd->t_task_lba, sectors, end_lba);
 172                 return -EINVAL;
 173         }
 174
 175         return 0;
 176 }
 177
 178 static inline u32 transport_get_sectors_6(unsigned char *cdb)
 179 {
 180         /*
 181          * Use 8-bit sector value.  SBC-3 says:
 182          *
 183          *   A TRANSFER LENGTH field set to zero specifies that 256
 184          *   logical blocks shall be written.  Any other value
 185          *   specifies the number of logical blocks that shall be
 186          *   written.
 187          */
 188         return cdb[4] ? : 256;
 189 }
 190
 191 static inline u32 transport_get_sectors_10(unsigned char *cdb)
 192 {
 193         return (u32)(cdb[7] << 8) + cdb[8];
 194 }
 195
 196 static inline u32 transport_get_sectors_12(unsigned char *cdb)
 197 {
 198         return (u32)(cdb[6] << 24) + (cdb[7] << 16) + (cdb[8] << 8) + cdb[9];
 199 }
 200
 201 static inline u32 transport_get_sectors_16(unsigned char *cdb)
 202 {
 203         return (u32)(cdb[10] << 24) + (cdb[11] << 16) +
 204                     (cdb[12] << 8) + cdb[13];
 205 }
 206
 207 /*
 208  * Used for VARIABLE_LENGTH_CDB WRITE_32 and READ_32 variants
 209  */
 210 static inline u32 transport_get_sectors_32(unsigned char *cdb)
 211 {
 212         return (u32)(cdb[28] << 24) + (cdb[29] << 16) +
 213                     (cdb[30] << 8) + cdb[31];
 214
 215 }
 216
 217 static inline u32 transport_lba_21(unsigned char *cdb)
 218 {
 219         return ((cdb[1] & 0x1f) << 16) | (cdb[2] << 8) | cdb[3];
 220 }
 221
 222 static inline u32 transport_lba_32(unsigned char *cdb)
 223 {
 224         return (cdb[2] << 24) | (cdb[3] << 16) | (cdb[4] << 8) | cdb[5];
 225 }
 226
 227 static inline unsigned long long transport_lba_64(unsigned char *cdb)
 228 {
 229         unsigned int __v1, __v2;
 230
 231         __v1 = (cdb[2] << 24) | (cdb[3] << 16) | (cdb[4] << 8) | cdb[5];
 232         __v2 = (cdb[6] << 24) | (cdb[7] << 16) | (cdb[8] << 8) | cdb[9];
 233
 234         return ((unsigned long long)__v2) | (unsigned long long)__v1 << 32;
 235 }
 236
 237 /*
 238  * For VARIABLE_LENGTH_CDB w/ 32 byte extended CDBs
 239  */
 240 static inline unsigned long long transport_lba_64_ext(unsigned char *cdb)
 241 {
 242         unsigned int __v1, __v2;
 243
 244         __v1 = (cdb[12] << 24) | (cdb[13] << 16) | (cdb[14] << 8) | cdb[15];
 245         __v2 = (cdb[16] << 24) | (cdb[17] << 16) | (cdb[18] << 8) | cdb[19];
 246
 247         return ((unsigned long long)__v2) | (unsigned long long)__v1 << 32;
 248 }
 249
 250 static sense_reason_t
 251 sbc_setup_write_same(struct se_cmd *cmd, unsigned char *flags, struct sbc_ops *ops)
 252 {
 253         unsigned int sectors = sbc_get_write_same_sectors(cmd);
 254
 255         if ((flags[0] & 0x04) || (flags[0] & 0x02)) {
 256                 pr_err("WRITE_SAME PBDATA and LBDATA"
 257                         " bits not supported for Block Discard"
 258                         " Emulation\n");
 259                 return TCM_UNSUPPORTED_SCSI_OPCODE;
 260         }
 261         if (sectors > cmd->se_dev->dev_attrib.max_write_same_len) {
 262                 pr_warn("WRITE_SAME sectors: %u exceeds max_write_same_len: %u\n",
 263                         sectors, cmd->se_dev->dev_attrib.max_write_same_len);
 264                 return TCM_INVALID_CDB_FIELD;
 265         }
 266         /*
 267          * Special case for WRITE_SAME w/ UNMAP=1 that ends up getting
 268          * translated into block discard requests within backend code.
 269          */
 270         if (flags[0] & 0x08) {
 271                 if (!ops->execute_write_same_unmap)
 272                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 273
 274                 cmd->execute_cmd = ops->execute_write_same_unmap;
 275                 return 0;
 276         }
 277         if (!ops->execute_write_same)
 278                 return TCM_UNSUPPORTED_SCSI_OPCODE;
 279
 280         cmd->execute_cmd = ops->execute_write_same;
 281         return 0;
 282 }
 283
 284 static sense_reason_t xdreadwrite_callback(struct se_cmd *cmd)
 285 {
 286         unsigned char *buf, *addr;
 287         struct scatterlist *sg;
 288         unsigned int offset;
 289         sense_reason_t ret = TCM_NO_SENSE;
 290         int i, count;
 291         /*
 292          * From sbc3r22.pdf section 5.48 XDWRITEREAD (10) command
 293          *
 294          * 1) read the specified logical block(s);
 295          * 2) transfer logical blocks from the data-out buffer;
 296          * 3) XOR the logical blocks transferred from the data-out buffer with
 297          *    the logical blocks read, storing the resulting XOR data in a buffer;
 298          * 4) if the DISABLE WRITE bit is set to zero, then write the logical
 299          *    blocks transferred from the data-out buffer; and
 300          * 5) transfer the resulting XOR data to the data-in buffer.
 301          */
 302         buf = kmalloc(cmd->data_length, GFP_KERNEL);
 303         if (!buf) {
 304                 pr_err("Unable to allocate xor_callback buf\n");
 305                 return TCM_OUT_OF_RESOURCES;
 306         }
 307         /*
 308          * Copy the scatterlist WRITE buffer located at cmd->t_data_sg
 309          * into the locally allocated *buf
 310          */
 311         sg_copy_to_buffer(cmd->t_data_sg,
 312                           cmd->t_data_nents,
 313                           buf,
 314                           cmd->data_length);
 315
 316         /*
 317          * Now perform the XOR against the BIDI read memory located at
 318          * cmd->t_mem_bidi_list
 319          */
 320
 321         offset = 0;
 322         for_each_sg(cmd->t_bidi_data_sg, sg, cmd->t_bidi_data_nents, count) {
 323                 addr = kmap_atomic(sg_page(sg));
 324                 if (!addr) {
 325                         ret = TCM_OUT_OF_RESOURCES;
 326                         goto out;
 327                 }
 328
 329                 for (i = 0; i < sg->length; i++)
 330                         *(addr + sg->offset + i) ^= *(buf + offset + i);
 331
 332                 offset += sg->length;
 333                 kunmap_atomic(addr);
 334         }
 335
 336 out:
 337         kfree(buf);
 338         return ret;
 339 }
 340
 341 static sense_reason_t
 342 sbc_execute_rw(struct se_cmd *cmd)
 343 {
 344         return cmd->execute_rw(cmd, cmd->t_data_sg, cmd->t_data_nents,
 345                                cmd->data_direction);
 346 }
 347
 348 static sense_reason_t compare_and_write_post(struct se_cmd *cmd)
 349 {
 350         struct se_device *dev = cmd->se_dev;
 351
 352         cmd->se_cmd_flags |= SCF_COMPARE_AND_WRITE_POST;
 353         /*
 354          * Unlock ->caw_sem originally obtained during sbc_compare_and_write()
 355          * before the original READ I/O submission.
 356          */
 357         up(&dev->caw_sem);
 358
 359         return TCM_NO_SENSE;
 360 }
 361
 362 static sense_reason_t compare_and_write_callback(struct se_cmd *cmd)
 363 {
 364         struct se_device *dev = cmd->se_dev;
 365         struct scatterlist *write_sg = NULL, *sg;
 366         unsigned char *buf, *addr;
 367         struct sg_mapping_iter m;
 368         unsigned int offset = 0, len;
 369         unsigned int nlbas = cmd->t_task_nolb;
 370         unsigned int block_size = dev->dev_attrib.block_size;
 371         unsigned int compare_len = (nlbas * block_size);
 372         sense_reason_t ret = TCM_NO_SENSE;
 373         int rc, i;
 374
 375         /*
 376          * Handle early failure in transport_generic_request_failure(),
 377          * which will not have taken ->caw_mutex yet..
 378          */
 379         if (!cmd->t_data_sg || !cmd->t_bidi_data_sg)
 380                 return TCM_NO_SENSE;
 381
 382         buf = kzalloc(cmd->data_length, GFP_KERNEL);
 383         if (!buf) {
 384                 pr_err("Unable to allocate compare_and_write buf\n");
 385                 ret = TCM_OUT_OF_RESOURCES;
 386                 goto out;
 387         }
 388
 389         write_sg = kzalloc(sizeof(struct scatterlist) * cmd->t_data_nents,
 390                            GFP_KERNEL);
 391         if (!write_sg) {
 392                 pr_err("Unable to allocate compare_and_write sg\n");
 393                 ret = TCM_OUT_OF_RESOURCES;
 394                 goto out;
 395         }
 396         /*
 397          * Setup verify and write data payloads from total NumberLBAs.
 398          */
 399         rc = sg_copy_to_buffer(cmd->t_data_sg, cmd->t_data_nents, buf,
 400                                cmd->data_length);
 401         if (!rc) {
 402                 pr_err("sg_copy_to_buffer() failed for compare_and_write\n");
 403                 ret = TCM_OUT_OF_RESOURCES;
 404                 goto out;
 405         }
 406         /*
 407          * Compare against SCSI READ payload against verify payload
 408          */
 409         for_each_sg(cmd->t_bidi_data_sg, sg, cmd->t_bidi_data_nents, i) {
 410                 addr = (unsigned char *)kmap_atomic(sg_page(sg));
 411                 if (!addr) {
 412                         ret = TCM_OUT_OF_RESOURCES;
 413                         goto out;
 414                 }
 415
 416                 len = min(sg->length, compare_len);
 417
 418                 if (memcmp(addr, buf + offset, len)) {
 419                         pr_warn("Detected MISCOMPARE for addr: %p buf: %p\n",
 420                                 addr, buf + offset);
 421                         kunmap_atomic(addr);
 422                         goto miscompare;
 423                 }
 424                 kunmap_atomic(addr);
 425
 426                 offset += len;
 427                 compare_len -= len;
 428                 if (!compare_len)
 429                         break;
 430         }
 431
 432         i = 0;
 433         len = cmd->t_task_nolb * block_size;
 434         sg_miter_start(&m, cmd->t_data_sg, cmd->t_data_nents, SG_MITER_TO_SG);
 435         /*
 436          * Currently assumes NoLB=1 and SGLs are PAGE_SIZE..
 437          */
 438         while (len) {
 439                 sg_miter_next(&m);
 440
 441                 if (block_size < PAGE_SIZE) {
 442                         sg_set_page(&write_sg[i], m.page, block_size,
 443                                     block_size);
 444                 } else {
 445                         sg_miter_next(&m);
 446                         sg_set_page(&write_sg[i], m.page, block_size,
 447                                     0);
 448                 }
 449                 len -= block_size;
 450                 i++;
 451         }
 452         sg_miter_stop(&m);
 453         /*
 454          * Save the original SGL + nents values before updating to new
 455          * assignments, to be released in transport_free_pages() ->
 456          * transport_reset_sgl_orig()
 457          */
 458         cmd->t_data_sg_orig = cmd->t_data_sg;
 459         cmd->t_data_sg = write_sg;
 460         cmd->t_data_nents_orig = cmd->t_data_nents;
 461         cmd->t_data_nents = 1;
 462
 463         cmd->sam_task_attr = MSG_HEAD_TAG;
 464         cmd->transport_complete_callback = compare_and_write_post;
 465         /*
 466          * Now reset ->execute_cmd() to the normal sbc_execute_rw() handler
 467          * for submitting the adjusted SGL to write instance user-data.
 468          */
 469         cmd->execute_cmd = sbc_execute_rw;
 470
 471         spin_lock_irq(&cmd->t_state_lock);
 472         cmd->t_state = TRANSPORT_PROCESSING;
 473         cmd->transport_state |= CMD_T_ACTIVE|CMD_T_BUSY|CMD_T_SENT;
 474         spin_unlock_irq(&cmd->t_state_lock);
 475
 476         __target_execute_cmd(cmd);
 477
 478         kfree(buf);
 479         return ret;
 480
 481 miscompare:
 482         pr_warn("Target/%s: Send MISCOMPARE check condition and sense\n",
 483                 dev->transport->name);
 484         ret = TCM_MISCOMPARE_VERIFY;
 485 out:
 486         /*
 487          * In the MISCOMPARE or failure case, unlock ->caw_sem obtained in
 488          * sbc_compare_and_write() before the original READ I/O submission.
 489          */
 490         up(&dev->caw_sem);
 491         kfree(write_sg);
 492         kfree(buf);
 493         return ret;
 494 }
 495
 496 static sense_reason_t
 497 sbc_compare_and_write(struct se_cmd *cmd)
 498 {
 499         struct se_device *dev = cmd->se_dev;
 500         sense_reason_t ret;
 501         int rc;
 502         /*
 503          * Submit the READ first for COMPARE_AND_WRITE to perform the
 504          * comparision using SGLs at cmd->t_bidi_data_sg..
 505          */
 506         rc = down_interruptible(&dev->caw_sem);
 507         if ((rc != 0) || signal_pending(current)) {
 508                 cmd->transport_complete_callback = NULL;
 509                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 510         }
 511         /*
 512          * Reset cmd->data_length to individual block_size in order to not
 513          * confuse backend drivers that depend on this value matching the
 514          * size of the I/O being submitted.
 515          */
 516         cmd->data_length = cmd->t_task_nolb * dev->dev_attrib.block_size;
 517
 518         ret = cmd->execute_rw(cmd, cmd->t_bidi_data_sg, cmd->t_bidi_data_nents,
 519                               DMA_FROM_DEVICE);
 520         if (ret) {
 521                 cmd->transport_complete_callback = NULL;
 522                 up(&dev->caw_sem);
 523                 return ret;
 524         }
 525         /*
 526          * Unlock of dev->caw_sem to occur in compare_and_write_callback()
 527          * upon MISCOMPARE, or in compare_and_write_done() upon completion
 528          * of WRITE instance user-data.
 529          */
 530         return TCM_NO_SENSE;
 531 }
 532
 533 sense_reason_t
 534 sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
 535 {
 536         struct se_device *dev = cmd->se_dev;
 537         unsigned char *cdb = cmd->t_task_cdb;
 538         unsigned int size;
 539         u32 sectors = 0;
 540         sense_reason_t ret;
 541
 542         switch (cdb[0]) {
 543         case READ_6:
 544                 sectors = transport_get_sectors_6(cdb);
 545                 cmd->t_task_lba = transport_lba_21(cdb);
 546                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 547                 cmd->execute_rw = ops->execute_rw;
 548                 cmd->execute_cmd = sbc_execute_rw;
 549                 break;
 550         case READ_10:
 551                 sectors = transport_get_sectors_10(cdb);
 552                 cmd->t_task_lba = transport_lba_32(cdb);
 553                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 554                 cmd->execute_rw = ops->execute_rw;
 555                 cmd->execute_cmd = sbc_execute_rw;
 556                 break;
 557         case READ_12:
 558                 sectors = transport_get_sectors_12(cdb);
 559                 cmd->t_task_lba = transport_lba_32(cdb);
 560                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 561                 cmd->execute_rw = ops->execute_rw;
 562                 cmd->execute_cmd = sbc_execute_rw;
 563                 break;
 564         case READ_16:
 565                 sectors = transport_get_sectors_16(cdb);
 566                 cmd->t_task_lba = transport_lba_64(cdb);
 567                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 568                 cmd->execute_rw = ops->execute_rw;
 569                 cmd->execute_cmd = sbc_execute_rw;
 570                 break;
 571         case WRITE_6:
 572                 sectors = transport_get_sectors_6(cdb);
 573                 cmd->t_task_lba = transport_lba_21(cdb);
 574                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 575                 cmd->execute_rw = ops->execute_rw;
 576                 cmd->execute_cmd = sbc_execute_rw;
 577                 break;
 578         case WRITE_10:
 579         case WRITE_VERIFY:
 580                 sectors = transport_get_sectors_10(cdb);
 581                 cmd->t_task_lba = transport_lba_32(cdb);
 582                 if (cdb[1] & 0x8)
 583                         cmd->se_cmd_flags |= SCF_FUA;
 584                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 585                 cmd->execute_rw = ops->execute_rw;
 586                 cmd->execute_cmd = sbc_execute_rw;
 587                 break;
 588         case WRITE_12:
 589                 sectors = transport_get_sectors_12(cdb);
 590                 cmd->t_task_lba = transport_lba_32(cdb);
 591                 if (cdb[1] & 0x8)
 592                         cmd->se_cmd_flags |= SCF_FUA;
 593                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 594                 cmd->execute_rw = ops->execute_rw;
 595                 cmd->execute_cmd = sbc_execute_rw;
 596                 break;
 597         case WRITE_16:
 598                 sectors = transport_get_sectors_16(cdb);
 599                 cmd->t_task_lba = transport_lba_64(cdb);
 600                 if (cdb[1] & 0x8)
 601                         cmd->se_cmd_flags |= SCF_FUA;
 602                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 603                 cmd->execute_rw = ops->execute_rw;
 604                 cmd->execute_cmd = sbc_execute_rw;
 605                 break;
 606         case XDWRITEREAD_10:
 607                 if (cmd->data_direction != DMA_TO_DEVICE ||
 608                     !(cmd->se_cmd_flags & SCF_BIDI))
 609                         return TCM_INVALID_CDB_FIELD;
 610                 sectors = transport_get_sectors_10(cdb);
 611
 612                 cmd->t_task_lba = transport_lba_32(cdb);
 613                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 614
 615                 /*
 616                  * Setup BIDI XOR callback to be run after I/O completion.
 617                  */
 618                 cmd->execute_rw = ops->execute_rw;
 619                 cmd->execute_cmd = sbc_execute_rw;
 620                 cmd->transport_complete_callback = &xdreadwrite_callback;
 621                 if (cdb[1] & 0x8)
 622                         cmd->se_cmd_flags |= SCF_FUA;
 623                 break;
 624         case VARIABLE_LENGTH_CMD:
 625         {
 626                 u16 service_action = get_unaligned_be16(&cdb[8]);
 627                 switch (service_action) {
 628                 case XDWRITEREAD_32:
 629                         sectors = transport_get_sectors_32(cdb);
 630
 631                         /*
 632                          * Use WRITE_32 and READ_32 opcodes for the emulated
 633                          * XDWRITE_READ_32 logic.
 634                          */
 635                         cmd->t_task_lba = transport_lba_64_ext(cdb);
 636                         cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 637
 638                         /*
 639                          * Setup BIDI XOR callback to be run during after I/O
 640                          * completion.
 641                          */
 642                         cmd->execute_rw = ops->execute_rw;
 643                         cmd->execute_cmd = sbc_execute_rw;
 644                         cmd->transport_complete_callback = &xdreadwrite_callback;
 645                         if (cdb[1] & 0x8)
 646                                 cmd->se_cmd_flags |= SCF_FUA;
 647                         break;
 648                 case WRITE_SAME_32:
 649                         sectors = transport_get_sectors_32(cdb);
 650                         if (!sectors) {
 651                                 pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not"
 652                                        " supported\n");
 653                                 return TCM_INVALID_CDB_FIELD;
 654                         }
 655
 656                         size = sbc_get_size(cmd, 1);
 657                         cmd->t_task_lba = get_unaligned_be64(&cdb[12]);
 658
 659                         ret = sbc_setup_write_same(cmd, &cdb[10], ops);
 660                         if (ret)
 661                                 return ret;
 662                         break;
 663                 default:
 664                         pr_err("VARIABLE_LENGTH_CMD service action"
 665                                 " 0x%04x not supported\n", service_action);
 666                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 667                 }
 668                 break;
 669         }
 670         case COMPARE_AND_WRITE:
 671                 sectors = cdb[13];
 672                 /*
 673                  * Currently enforce COMPARE_AND_WRITE for a single sector
 674                  */
 675                 if (sectors > 1) {
 676                         pr_err("COMPARE_AND_WRITE contains NoLB: %u greater"
 677                                " than 1\n", sectors);
 678                         return TCM_INVALID_CDB_FIELD;
 679                 }
 680                 /*
 681                  * Double size because we have two buffers, note that
 682                  * zero is not an error..
 683                  */
 684                 size = 2 * sbc_get_size(cmd, sectors);
 685                 cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
 686                 cmd->t_task_nolb = sectors;
 687                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB | SCF_COMPARE_AND_WRITE;
 688                 cmd->execute_rw = ops->execute_rw;
 689                 cmd->execute_cmd = sbc_compare_and_write;
 690                 cmd->transport_complete_callback = compare_and_write_callback;
 691                 break;
 692         case READ_CAPACITY:
 693                 size = READ_CAP_LEN;
 694                 cmd->execute_cmd = sbc_emulate_readcapacity;
 695                 break;
 696         case SERVICE_ACTION_IN:
 697                 switch (cmd->t_task_cdb[1] & 0x1f) {
 698                 case SAI_READ_CAPACITY_16:
 699                         cmd->execute_cmd = sbc_emulate_readcapacity_16;
 700                         break;
 701                 default:
 702                         pr_err("Unsupported SA: 0x%02x\n",
 703                                 cmd->t_task_cdb[1] & 0x1f);
 704                         return TCM_INVALID_CDB_FIELD;
 705                 }
 706                 size = (cdb[10] << 24) | (cdb[11] << 16) |
 707                        (cdb[12] << 8) | cdb[13];
 708                 break;
 709         case SYNCHRONIZE_CACHE:
 710         case SYNCHRONIZE_CACHE_16:
 711                 if (!ops->execute_sync_cache) {
 712                         size = 0;
 713                         cmd->execute_cmd = sbc_emulate_noop;
 714                         break;
 715                 }
 716
 717                 /*
 718                  * Extract LBA and range to be flushed for emulated SYNCHRONIZE_CACHE
 719                  */
 720                 if (cdb[0] == SYNCHRONIZE_CACHE) {
 721                         sectors = transport_get_sectors_10(cdb);
 722                         cmd->t_task_lba = transport_lba_32(cdb);
 723                 } else {
 724                         sectors = transport_get_sectors_16(cdb);
 725                         cmd->t_task_lba = transport_lba_64(cdb);
 726                 }
 727
 728                 size = sbc_get_size(cmd, sectors);
 729
 730                 /*
 731                  * Check to ensure that LBA + Range does not exceed past end of
 732                  * device for IBLOCK and FILEIO ->do_sync_cache() backend calls
 733                  */
 734                 if (cmd->t_task_lba || sectors) {
 735                         if (sbc_check_valid_sectors(cmd) < 0)
 736                                 return TCM_ADDRESS_OUT_OF_RANGE;
 737                 }
 738                 cmd->execute_cmd = ops->execute_sync_cache;
 739                 break;
 740         case UNMAP:
 741                 if (!ops->execute_unmap)
 742                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 743
 744                 size = get_unaligned_be16(&cdb[7]);
 745                 cmd->execute_cmd = ops->execute_unmap;
 746                 break;
 747         case WRITE_SAME_16:
 748                 sectors = transport_get_sectors_16(cdb);
 749                 if (!sectors) {
 750                         pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
 751                         return TCM_INVALID_CDB_FIELD;
 752                 }
 753
 754                 size = sbc_get_size(cmd, 1);
 755                 cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
 756
 757                 ret = sbc_setup_write_same(cmd, &cdb[1], ops);
 758                 if (ret)
 759                         return ret;
 760                 break;
 761         case WRITE_SAME:
 762                 sectors = transport_get_sectors_10(cdb);
 763                 if (!sectors) {
 764                         pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
 765                         return TCM_INVALID_CDB_FIELD;
 766                 }
 767
 768                 size = sbc_get_size(cmd, 1);
 769                 cmd->t_task_lba = get_unaligned_be32(&cdb[2]);
 770
 771                 /*
 772                  * Follow sbcr26 with WRITE_SAME (10) and check for the existence
 773                  * of byte 1 bit 3 UNMAP instead of original reserved field
 774                  */
 775                 ret = sbc_setup_write_same(cmd, &cdb[1], ops);
 776                 if (ret)
 777                         return ret;
 778                 break;
 779         case VERIFY:
 780                 size = 0;
 781                 cmd->execute_cmd = sbc_emulate_noop;
 782                 break;
 783         case REZERO_UNIT:
 784         case SEEK_6:
 785         case SEEK_10:
 786                 /*
 787                  * There are still clients out there which use these old SCSI-2
 788                  * commands. This mainly happens when running VMs with legacy
 789                  * guest systems, connected via SCSI command pass-through to
 790                  * iSCSI targets. Make them happy and return status GOOD.
 791                  */
 792                 size = 0;
 793                 cmd->execute_cmd = sbc_emulate_noop;
 794                 break;
 795         default:
 796                 ret = spc_parse_cdb(cmd, &size);
 797                 if (ret)
 798                         return ret;
 799         }
 800
 801         /* reject any command that we don't have a handler for */
 802         if (!(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) && !cmd->execute_cmd)
 803                 return TCM_UNSUPPORTED_SCSI_OPCODE;
 804
 805         if (cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
 806                 unsigned long long end_lba;
 807
 808                 if (sectors > dev->dev_attrib.fabric_max_sectors) {
 809                         printk_ratelimited(KERN_ERR "SCSI OP %02xh with too"
 810                                 " big sectors %u exceeds fabric_max_sectors:"
 811                                 " %u\n", cdb[0], sectors,
 812                                 dev->dev_attrib.fabric_max_sectors);
 813                         return TCM_INVALID_CDB_FIELD;
 814                 }
 815                 if (sectors > dev->dev_attrib.hw_max_sectors) {
 816                         printk_ratelimited(KERN_ERR "SCSI OP %02xh with too"
 817                                 " big sectors %u exceeds backend hw_max_sectors:"
 818                                 " %u\n", cdb[0], sectors,
 819                                 dev->dev_attrib.hw_max_sectors);
 820                         return TCM_INVALID_CDB_FIELD;
 821                 }
 822
 823                 end_lba = dev->transport->get_blocks(dev) + 1;
 824                 if (cmd->t_task_lba + sectors > end_lba) {
 825                         pr_err("cmd exceeds last lba %llu "
 826                                 "(lba %llu, sectors %u)\n",
 827                                 end_lba, cmd->t_task_lba, sectors);
 828                         return TCM_ADDRESS_OUT_OF_RANGE;
 829                 }
 830
 831                 if (!(cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE))
 832                         size = sbc_get_size(cmd, sectors);
 833         }
 834
 835         return target_cmd_size_check(cmd, size);
 836 }
 837 EXPORT_SYMBOL(sbc_parse_cdb);
 838
 839 u32 sbc_get_device_type(struct se_device *dev)
 840 {
 841         return TYPE_DISK;
 842 }
 843 EXPORT_SYMBOL(sbc_get_device_type);
 844
 845 sense_reason_t
 846 sbc_execute_unmap(struct se_cmd *cmd,
 847         sense_reason_t (*do_unmap_fn)(struct se_cmd *, void *,
 848                                       sector_t, sector_t),
 849         void *priv)
 850 {
 851         struct se_device *dev = cmd->se_dev;
 852         unsigned char *buf, *ptr = NULL;
 853         sector_t lba;
 854         int size;
 855         u32 range;
 856         sense_reason_t ret = 0;
 857         int dl, bd_dl;
 858
 859         /* We never set ANC_SUP */
 860         if (cmd->t_task_cdb[1])
 861                 return TCM_INVALID_CDB_FIELD;
 862
 863         if (cmd->data_length == 0) {
 864                 target_complete_cmd(cmd, SAM_STAT_GOOD);
 865                 return 0;
 866         }
 867
 868         if (cmd->data_length < 8) {
 869                 pr_warn("UNMAP parameter list length %u too small\n",
 870                         cmd->data_length);
 871                 return TCM_PARAMETER_LIST_LENGTH_ERROR;
 872         }
 873
 874         buf = transport_kmap_data_sg(cmd);
 875         if (!buf)
 876                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 877
 878         dl = get_unaligned_be16(&buf[0]);
 879         bd_dl = get_unaligned_be16(&buf[2]);
 880
 881         size = cmd->data_length - 8;
 882         if (bd_dl > size)
 883                 pr_warn("UNMAP parameter list length %u too small, ignoring bd_dl %u\n",
 884                         cmd->data_length, bd_dl);
 885         else
 886                 size = bd_dl;
 887
 888         if (size / 16 > dev->dev_attrib.max_unmap_block_desc_count) {
 889                 ret = TCM_INVALID_PARAMETER_LIST;
 890                 goto err;
 891         }
 892
 893         /* First UNMAP block descriptor starts at 8 byte offset */
 894         ptr = &buf[8];
 895         pr_debug("UNMAP: Sub: %s Using dl: %u bd_dl: %u size: %u"
 896                 " ptr: %p\n", dev->transport->name, dl, bd_dl, size, ptr);
 897
 898         while (size >= 16) {
 899                 lba = get_unaligned_be64(&ptr[0]);
 900                 range = get_unaligned_be32(&ptr[8]);
 901                 pr_debug("UNMAP: Using lba: %llu and range: %u\n",
 902                                  (unsigned long long)lba, range);
 903
 904                 if (range > dev->dev_attrib.max_unmap_lba_count) {
 905                         ret = TCM_INVALID_PARAMETER_LIST;
 906                         goto err;
 907                 }
 908
 909                 if (lba + range > dev->transport->get_blocks(dev) + 1) {
 910                         ret = TCM_ADDRESS_OUT_OF_RANGE;
 911                         goto err;
 912                 }
 913
 914                 ret = do_unmap_fn(cmd, priv, lba, range);
 915                 if (ret)
 916                         goto err;
 917
 918                 ptr += 16;
 919                 size -= 16;
 920         }
 921
 922 err:
 923         transport_kunmap_data_sg(cmd);
 924         if (!ret)
 925                 target_complete_cmd(cmd, GOOD);
 926         return ret;
 927 }
 928 EXPORT_SYMBOL(sbc_execute_unmap);