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         /* We always have ANC_SUP == 0 so setting ANCHOR is always an error */
 267         if (flags[0] & 0x10) {
 268                 pr_warn("WRITE SAME with ANCHOR not supported\n");
 269                 return TCM_INVALID_CDB_FIELD;
 270         }
 271         /*
 272          * Special case for WRITE_SAME w/ UNMAP=1 that ends up getting
 273          * translated into block discard requests within backend code.
 274          */
 275         if (flags[0] & 0x08) {
 276                 if (!ops->execute_write_same_unmap)
 277                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 278
 279                 cmd->execute_cmd = ops->execute_write_same_unmap;
 280                 return 0;
 281         }
 282         if (!ops->execute_write_same)
 283                 return TCM_UNSUPPORTED_SCSI_OPCODE;
 284
 285         cmd->execute_cmd = ops->execute_write_same;
 286         return 0;
 287 }
 288
 289 static sense_reason_t xdreadwrite_callback(struct se_cmd *cmd)
 290 {
 291         unsigned char *buf, *addr;
 292         struct scatterlist *sg;
 293         unsigned int offset;
 294         sense_reason_t ret = TCM_NO_SENSE;
 295         int i, count;
 296         /*
 297          * From sbc3r22.pdf section 5.48 XDWRITEREAD (10) command
 298          *
 299          * 1) read the specified logical block(s);
 300          * 2) transfer logical blocks from the data-out buffer;
 301          * 3) XOR the logical blocks transferred from the data-out buffer with
 302          *    the logical blocks read, storing the resulting XOR data in a buffer;
 303          * 4) if the DISABLE WRITE bit is set to zero, then write the logical
 304          *    blocks transferred from the data-out buffer; and
 305          * 5) transfer the resulting XOR data to the data-in buffer.
 306          */
 307         buf = kmalloc(cmd->data_length, GFP_KERNEL);
 308         if (!buf) {
 309                 pr_err("Unable to allocate xor_callback buf\n");
 310                 return TCM_OUT_OF_RESOURCES;
 311         }
 312         /*
 313          * Copy the scatterlist WRITE buffer located at cmd->t_data_sg
 314          * into the locally allocated *buf
 315          */
 316         sg_copy_to_buffer(cmd->t_data_sg,
 317                           cmd->t_data_nents,
 318                           buf,
 319                           cmd->data_length);
 320
 321         /*
 322          * Now perform the XOR against the BIDI read memory located at
 323          * cmd->t_mem_bidi_list
 324          */
 325
 326         offset = 0;
 327         for_each_sg(cmd->t_bidi_data_sg, sg, cmd->t_bidi_data_nents, count) {
 328                 addr = kmap_atomic(sg_page(sg));
 329                 if (!addr) {
 330                         ret = TCM_OUT_OF_RESOURCES;
 331                         goto out;
 332                 }
 333
 334                 for (i = 0; i < sg->length; i++)
 335                         *(addr + sg->offset + i) ^= *(buf + offset + i);
 336
 337                 offset += sg->length;
 338                 kunmap_atomic(addr);
 339         }
 340
 341 out:
 342         kfree(buf);
 343         return ret;
 344 }
 345
 346 static sense_reason_t
 347 sbc_execute_rw(struct se_cmd *cmd)
 348 {
 349         return cmd->execute_rw(cmd, cmd->t_data_sg, cmd->t_data_nents,
 350                                cmd->data_direction);
 351 }
 352
 353 static sense_reason_t compare_and_write_post(struct se_cmd *cmd)
 354 {
 355         struct se_device *dev = cmd->se_dev;
 356
 357         /*
 358          * Only set SCF_COMPARE_AND_WRITE_POST to force a response fall-through
 359          * within target_complete_ok_work() if the command was successfully
 360          * sent to the backend driver.
 361          */
 362         spin_lock_irq(&cmd->t_state_lock);
 363         if ((cmd->transport_state & CMD_T_SENT) && !cmd->scsi_status)
 364                 cmd->se_cmd_flags |= SCF_COMPARE_AND_WRITE_POST;
 365         spin_unlock_irq(&cmd->t_state_lock);
 366
 367         /*
 368          * Unlock ->caw_sem originally obtained during sbc_compare_and_write()
 369          * before the original READ I/O submission.
 370          */
 371         up(&dev->caw_sem);
 372
 373         return TCM_NO_SENSE;
 374 }
 375
 376 static sense_reason_t compare_and_write_callback(struct se_cmd *cmd)
 377 {
 378         struct se_device *dev = cmd->se_dev;
 379         struct scatterlist *write_sg = NULL, *sg;
 380         unsigned char *buf = NULL, *addr;
 381         struct sg_mapping_iter m;
 382         unsigned int offset = 0, len;
 383         unsigned int nlbas = cmd->t_task_nolb;
 384         unsigned int block_size = dev->dev_attrib.block_size;
 385         unsigned int compare_len = (nlbas * block_size);
 386         sense_reason_t ret = TCM_NO_SENSE;
 387         int rc, i;
 388
 389         /*
 390          * Handle early failure in transport_generic_request_failure(),
 391          * which will not have taken ->caw_mutex yet..
 392          */
 393         if (!cmd->t_data_sg || !cmd->t_bidi_data_sg)
 394                 return TCM_NO_SENSE;
 395         /*
 396          * Immediately exit + release dev->caw_sem if command has already
 397          * been failed with a non-zero SCSI status.
 398          */
 399         if (cmd->scsi_status) {
 400                 pr_err("compare_and_write_callback: non zero scsi_status:"
 401                         " 0x%02x\n", cmd->scsi_status);
 402                 goto out;
 403         }
 404
 405         buf = kzalloc(cmd->data_length, GFP_KERNEL);
 406         if (!buf) {
 407                 pr_err("Unable to allocate compare_and_write buf\n");
 408                 ret = TCM_OUT_OF_RESOURCES;
 409                 goto out;
 410         }
 411
 412         write_sg = kzalloc(sizeof(struct scatterlist) * cmd->t_data_nents,
 413                            GFP_KERNEL);
 414         if (!write_sg) {
 415                 pr_err("Unable to allocate compare_and_write sg\n");
 416                 ret = TCM_OUT_OF_RESOURCES;
 417                 goto out;
 418         }
 419         /*
 420          * Setup verify and write data payloads from total NumberLBAs.
 421          */
 422         rc = sg_copy_to_buffer(cmd->t_data_sg, cmd->t_data_nents, buf,
 423                                cmd->data_length);
 424         if (!rc) {
 425                 pr_err("sg_copy_to_buffer() failed for compare_and_write\n");
 426                 ret = TCM_OUT_OF_RESOURCES;
 427                 goto out;
 428         }
 429         /*
 430          * Compare against SCSI READ payload against verify payload
 431          */
 432         for_each_sg(cmd->t_bidi_data_sg, sg, cmd->t_bidi_data_nents, i) {
 433                 addr = (unsigned char *)kmap_atomic(sg_page(sg));
 434                 if (!addr) {
 435                         ret = TCM_OUT_OF_RESOURCES;
 436                         goto out;
 437                 }
 438
 439                 len = min(sg->length, compare_len);
 440
 441                 if (memcmp(addr, buf + offset, len)) {
 442                         pr_warn("Detected MISCOMPARE for addr: %p buf: %p\n",
 443                                 addr, buf + offset);
 444                         kunmap_atomic(addr);
 445                         goto miscompare;
 446                 }
 447                 kunmap_atomic(addr);
 448
 449                 offset += len;
 450                 compare_len -= len;
 451                 if (!compare_len)
 452                         break;
 453         }
 454
 455         i = 0;
 456         len = cmd->t_task_nolb * block_size;
 457         sg_miter_start(&m, cmd->t_data_sg, cmd->t_data_nents, SG_MITER_TO_SG);
 458         /*
 459          * Currently assumes NoLB=1 and SGLs are PAGE_SIZE..
 460          */
 461         while (len) {
 462                 sg_miter_next(&m);
 463
 464                 if (block_size < PAGE_SIZE) {
 465                         sg_set_page(&write_sg[i], m.page, block_size,
 466                                     block_size);
 467                 } else {
 468                         sg_miter_next(&m);
 469                         sg_set_page(&write_sg[i], m.page, block_size,
 470                                     0);
 471                 }
 472                 len -= block_size;
 473                 i++;
 474         }
 475         sg_miter_stop(&m);
 476         /*
 477          * Save the original SGL + nents values before updating to new
 478          * assignments, to be released in transport_free_pages() ->
 479          * transport_reset_sgl_orig()
 480          */
 481         cmd->t_data_sg_orig = cmd->t_data_sg;
 482         cmd->t_data_sg = write_sg;
 483         cmd->t_data_nents_orig = cmd->t_data_nents;
 484         cmd->t_data_nents = 1;
 485
 486         cmd->sam_task_attr = MSG_HEAD_TAG;
 487         cmd->transport_complete_callback = compare_and_write_post;
 488         /*
 489          * Now reset ->execute_cmd() to the normal sbc_execute_rw() handler
 490          * for submitting the adjusted SGL to write instance user-data.
 491          */
 492         cmd->execute_cmd = sbc_execute_rw;
 493
 494         spin_lock_irq(&cmd->t_state_lock);
 495         cmd->t_state = TRANSPORT_PROCESSING;
 496         cmd->transport_state |= CMD_T_ACTIVE|CMD_T_BUSY|CMD_T_SENT;
 497         spin_unlock_irq(&cmd->t_state_lock);
 498
 499         __target_execute_cmd(cmd);
 500
 501         kfree(buf);
 502         return ret;
 503
 504 miscompare:
 505         pr_warn("Target/%s: Send MISCOMPARE check condition and sense\n",
 506                 dev->transport->name);
 507         ret = TCM_MISCOMPARE_VERIFY;
 508 out:
 509         /*
 510          * In the MISCOMPARE or failure case, unlock ->caw_sem obtained in
 511          * sbc_compare_and_write() before the original READ I/O submission.
 512          */
 513         up(&dev->caw_sem);
 514         kfree(write_sg);
 515         kfree(buf);
 516         return ret;
 517 }
 518
 519 static sense_reason_t
 520 sbc_compare_and_write(struct se_cmd *cmd)
 521 {
 522         struct se_device *dev = cmd->se_dev;
 523         sense_reason_t ret;
 524         int rc;
 525         /*
 526          * Submit the READ first for COMPARE_AND_WRITE to perform the
 527          * comparision using SGLs at cmd->t_bidi_data_sg..
 528          */
 529         rc = down_interruptible(&dev->caw_sem);
 530         if ((rc != 0) || signal_pending(current)) {
 531                 cmd->transport_complete_callback = NULL;
 532                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 533         }
 534         /*
 535          * Reset cmd->data_length to individual block_size in order to not
 536          * confuse backend drivers that depend on this value matching the
 537          * size of the I/O being submitted.
 538          */
 539         cmd->data_length = cmd->t_task_nolb * dev->dev_attrib.block_size;
 540
 541         ret = cmd->execute_rw(cmd, cmd->t_bidi_data_sg, cmd->t_bidi_data_nents,
 542                               DMA_FROM_DEVICE);
 543         if (ret) {
 544                 cmd->transport_complete_callback = NULL;
 545                 up(&dev->caw_sem);
 546                 return ret;
 547         }
 548         /*
 549          * Unlock of dev->caw_sem to occur in compare_and_write_callback()
 550          * upon MISCOMPARE, or in compare_and_write_done() upon completion
 551          * of WRITE instance user-data.
 552          */
 553         return TCM_NO_SENSE;
 554 }
 555
 556 sense_reason_t
 557 sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
 558 {
 559         struct se_device *dev = cmd->se_dev;
 560         unsigned char *cdb = cmd->t_task_cdb;
 561         unsigned int size;
 562         u32 sectors = 0;
 563         sense_reason_t ret;
 564
 565         switch (cdb[0]) {
 566         case READ_6:
 567                 sectors = transport_get_sectors_6(cdb);
 568                 cmd->t_task_lba = transport_lba_21(cdb);
 569                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 570                 cmd->execute_rw = ops->execute_rw;
 571                 cmd->execute_cmd = sbc_execute_rw;
 572                 break;
 573         case READ_10:
 574                 sectors = transport_get_sectors_10(cdb);
 575                 cmd->t_task_lba = transport_lba_32(cdb);
 576                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 577                 cmd->execute_rw = ops->execute_rw;
 578                 cmd->execute_cmd = sbc_execute_rw;
 579                 break;
 580         case READ_12:
 581                 sectors = transport_get_sectors_12(cdb);
 582                 cmd->t_task_lba = transport_lba_32(cdb);
 583                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 584                 cmd->execute_rw = ops->execute_rw;
 585                 cmd->execute_cmd = sbc_execute_rw;
 586                 break;
 587         case READ_16:
 588                 sectors = transport_get_sectors_16(cdb);
 589                 cmd->t_task_lba = transport_lba_64(cdb);
 590                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 591                 cmd->execute_rw = ops->execute_rw;
 592                 cmd->execute_cmd = sbc_execute_rw;
 593                 break;
 594         case WRITE_6:
 595                 sectors = transport_get_sectors_6(cdb);
 596                 cmd->t_task_lba = transport_lba_21(cdb);
 597                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 598                 cmd->execute_rw = ops->execute_rw;
 599                 cmd->execute_cmd = sbc_execute_rw;
 600                 break;
 601         case WRITE_10:
 602         case WRITE_VERIFY:
 603                 sectors = transport_get_sectors_10(cdb);
 604                 cmd->t_task_lba = transport_lba_32(cdb);
 605                 if (cdb[1] & 0x8)
 606                         cmd->se_cmd_flags |= SCF_FUA;
 607                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 608                 cmd->execute_rw = ops->execute_rw;
 609                 cmd->execute_cmd = sbc_execute_rw;
 610                 break;
 611         case WRITE_12:
 612                 sectors = transport_get_sectors_12(cdb);
 613                 cmd->t_task_lba = transport_lba_32(cdb);
 614                 if (cdb[1] & 0x8)
 615                         cmd->se_cmd_flags |= SCF_FUA;
 616                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 617                 cmd->execute_rw = ops->execute_rw;
 618                 cmd->execute_cmd = sbc_execute_rw;
 619                 break;
 620         case WRITE_16:
 621                 sectors = transport_get_sectors_16(cdb);
 622                 cmd->t_task_lba = transport_lba_64(cdb);
 623                 if (cdb[1] & 0x8)
 624                         cmd->se_cmd_flags |= SCF_FUA;
 625                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 626                 cmd->execute_rw = ops->execute_rw;
 627                 cmd->execute_cmd = sbc_execute_rw;
 628                 break;
 629         case XDWRITEREAD_10:
 630                 if (cmd->data_direction != DMA_TO_DEVICE ||
 631                     !(cmd->se_cmd_flags & SCF_BIDI))
 632                         return TCM_INVALID_CDB_FIELD;
 633                 sectors = transport_get_sectors_10(cdb);
 634
 635                 cmd->t_task_lba = transport_lba_32(cdb);
 636                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 637
 638                 /*
 639                  * Setup BIDI XOR callback to be run after I/O completion.
 640                  */
 641                 cmd->execute_rw = ops->execute_rw;
 642                 cmd->execute_cmd = sbc_execute_rw;
 643                 cmd->transport_complete_callback = &xdreadwrite_callback;
 644                 if (cdb[1] & 0x8)
 645                         cmd->se_cmd_flags |= SCF_FUA;
 646                 break;
 647         case VARIABLE_LENGTH_CMD:
 648         {
 649                 u16 service_action = get_unaligned_be16(&cdb[8]);
 650                 switch (service_action) {
 651                 case XDWRITEREAD_32:
 652                         sectors = transport_get_sectors_32(cdb);
 653
 654                         /*
 655                          * Use WRITE_32 and READ_32 opcodes for the emulated
 656                          * XDWRITE_READ_32 logic.
 657                          */
 658                         cmd->t_task_lba = transport_lba_64_ext(cdb);
 659                         cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 660
 661                         /*
 662                          * Setup BIDI XOR callback to be run during after I/O
 663                          * completion.
 664                          */
 665                         cmd->execute_rw = ops->execute_rw;
 666                         cmd->execute_cmd = sbc_execute_rw;
 667                         cmd->transport_complete_callback = &xdreadwrite_callback;
 668                         if (cdb[1] & 0x8)
 669                                 cmd->se_cmd_flags |= SCF_FUA;
 670                         break;
 671                 case WRITE_SAME_32:
 672                         sectors = transport_get_sectors_32(cdb);
 673                         if (!sectors) {
 674                                 pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not"
 675                                        " supported\n");
 676                                 return TCM_INVALID_CDB_FIELD;
 677                         }
 678
 679                         size = sbc_get_size(cmd, 1);
 680                         cmd->t_task_lba = get_unaligned_be64(&cdb[12]);
 681
 682                         ret = sbc_setup_write_same(cmd, &cdb[10], ops);
 683                         if (ret)
 684                                 return ret;
 685                         break;
 686                 default:
 687                         pr_err("VARIABLE_LENGTH_CMD service action"
 688                                 " 0x%04x not supported\n", service_action);
 689                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 690                 }
 691                 break;
 692         }
 693         case COMPARE_AND_WRITE:
 694                 sectors = cdb[13];
 695                 /*
 696                  * Currently enforce COMPARE_AND_WRITE for a single sector
 697                  */
 698                 if (sectors > 1) {
 699                         pr_err("COMPARE_AND_WRITE contains NoLB: %u greater"
 700                                " than 1\n", sectors);
 701                         return TCM_INVALID_CDB_FIELD;
 702                 }
 703                 /*
 704                  * Double size because we have two buffers, note that
 705                  * zero is not an error..
 706                  */
 707                 size = 2 * sbc_get_size(cmd, sectors);
 708                 cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
 709                 cmd->t_task_nolb = sectors;
 710                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB | SCF_COMPARE_AND_WRITE;
 711                 cmd->execute_rw = ops->execute_rw;
 712                 cmd->execute_cmd = sbc_compare_and_write;
 713                 cmd->transport_complete_callback = compare_and_write_callback;
 714                 break;
 715         case READ_CAPACITY:
 716                 size = READ_CAP_LEN;
 717                 cmd->execute_cmd = sbc_emulate_readcapacity;
 718                 break;
 719         case SERVICE_ACTION_IN:
 720                 switch (cmd->t_task_cdb[1] & 0x1f) {
 721                 case SAI_READ_CAPACITY_16:
 722                         cmd->execute_cmd = sbc_emulate_readcapacity_16;
 723                         break;
 724                 default:
 725                         pr_err("Unsupported SA: 0x%02x\n",
 726                                 cmd->t_task_cdb[1] & 0x1f);
 727                         return TCM_INVALID_CDB_FIELD;
 728                 }
 729                 size = (cdb[10] << 24) | (cdb[11] << 16) |
 730                        (cdb[12] << 8) | cdb[13];
 731                 break;
 732         case SYNCHRONIZE_CACHE:
 733         case SYNCHRONIZE_CACHE_16:
 734                 if (!ops->execute_sync_cache) {
 735                         size = 0;
 736                         cmd->execute_cmd = sbc_emulate_noop;
 737                         break;
 738                 }
 739
 740                 /*
 741                  * Extract LBA and range to be flushed for emulated SYNCHRONIZE_CACHE
 742                  */
 743                 if (cdb[0] == SYNCHRONIZE_CACHE) {
 744                         sectors = transport_get_sectors_10(cdb);
 745                         cmd->t_task_lba = transport_lba_32(cdb);
 746                 } else {
 747                         sectors = transport_get_sectors_16(cdb);
 748                         cmd->t_task_lba = transport_lba_64(cdb);
 749                 }
 750
 751                 size = sbc_get_size(cmd, sectors);
 752
 753                 /*
 754                  * Check to ensure that LBA + Range does not exceed past end of
 755                  * device for IBLOCK and FILEIO ->do_sync_cache() backend calls
 756                  */
 757                 if (cmd->t_task_lba || sectors) {
 758                         if (sbc_check_valid_sectors(cmd) < 0)
 759                                 return TCM_ADDRESS_OUT_OF_RANGE;
 760                 }
 761                 cmd->execute_cmd = ops->execute_sync_cache;
 762                 break;
 763         case UNMAP:
 764                 if (!ops->execute_unmap)
 765                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 766
 767                 size = get_unaligned_be16(&cdb[7]);
 768                 cmd->execute_cmd = ops->execute_unmap;
 769                 break;
 770         case WRITE_SAME_16:
 771                 sectors = transport_get_sectors_16(cdb);
 772                 if (!sectors) {
 773                         pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
 774                         return TCM_INVALID_CDB_FIELD;
 775                 }
 776
 777                 size = sbc_get_size(cmd, 1);
 778                 cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
 779
 780                 ret = sbc_setup_write_same(cmd, &cdb[1], ops);
 781                 if (ret)
 782                         return ret;
 783                 break;
 784         case WRITE_SAME:
 785                 sectors = transport_get_sectors_10(cdb);
 786                 if (!sectors) {
 787                         pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
 788                         return TCM_INVALID_CDB_FIELD;
 789                 }
 790
 791                 size = sbc_get_size(cmd, 1);
 792                 cmd->t_task_lba = get_unaligned_be32(&cdb[2]);
 793
 794                 /*
 795                  * Follow sbcr26 with WRITE_SAME (10) and check for the existence
 796                  * of byte 1 bit 3 UNMAP instead of original reserved field
 797                  */
 798                 ret = sbc_setup_write_same(cmd, &cdb[1], ops);
 799                 if (ret)
 800                         return ret;
 801                 break;
 802         case VERIFY:
 803                 size = 0;
 804                 cmd->execute_cmd = sbc_emulate_noop;
 805                 break;
 806         case REZERO_UNIT:
 807         case SEEK_6:
 808         case SEEK_10:
 809                 /*
 810                  * There are still clients out there which use these old SCSI-2
 811                  * commands. This mainly happens when running VMs with legacy
 812                  * guest systems, connected via SCSI command pass-through to
 813                  * iSCSI targets. Make them happy and return status GOOD.
 814                  */
 815                 size = 0;
 816                 cmd->execute_cmd = sbc_emulate_noop;
 817                 break;
 818         default:
 819                 ret = spc_parse_cdb(cmd, &size);
 820                 if (ret)
 821                         return ret;
 822         }
 823
 824         /* reject any command that we don't have a handler for */
 825         if (!(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) && !cmd->execute_cmd)
 826                 return TCM_UNSUPPORTED_SCSI_OPCODE;
 827
 828         if (cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
 829                 unsigned long long end_lba;
 830
 831                 if (sectors > dev->dev_attrib.fabric_max_sectors) {
 832                         printk_ratelimited(KERN_ERR "SCSI OP %02xh with too"
 833                                 " big sectors %u exceeds fabric_max_sectors:"
 834                                 " %u\n", cdb[0], sectors,
 835                                 dev->dev_attrib.fabric_max_sectors);
 836                         return TCM_INVALID_CDB_FIELD;
 837                 }
 838                 if (sectors > dev->dev_attrib.hw_max_sectors) {
 839                         printk_ratelimited(KERN_ERR "SCSI OP %02xh with too"
 840                                 " big sectors %u exceeds backend hw_max_sectors:"
 841                                 " %u\n", cdb[0], sectors,
 842                                 dev->dev_attrib.hw_max_sectors);
 843                         return TCM_INVALID_CDB_FIELD;
 844                 }
 845
 846                 end_lba = dev->transport->get_blocks(dev) + 1;
 847                 if (cmd->t_task_lba + sectors > end_lba) {
 848                         pr_err("cmd exceeds last lba %llu "
 849                                 "(lba %llu, sectors %u)\n",
 850                                 end_lba, cmd->t_task_lba, sectors);
 851                         return TCM_ADDRESS_OUT_OF_RANGE;
 852                 }
 853
 854                 if (!(cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE))
 855                         size = sbc_get_size(cmd, sectors);
 856         }
 857
 858         return target_cmd_size_check(cmd, size);
 859 }
 860 EXPORT_SYMBOL(sbc_parse_cdb);
 861
 862 u32 sbc_get_device_type(struct se_device *dev)
 863 {
 864         return TYPE_DISK;
 865 }
 866 EXPORT_SYMBOL(sbc_get_device_type);
 867
 868 sense_reason_t
 869 sbc_execute_unmap(struct se_cmd *cmd,
 870         sense_reason_t (*do_unmap_fn)(struct se_cmd *, void *,
 871                                       sector_t, sector_t),
 872         void *priv)
 873 {
 874         struct se_device *dev = cmd->se_dev;
 875         unsigned char *buf, *ptr = NULL;
 876         sector_t lba;
 877         int size;
 878         u32 range;
 879         sense_reason_t ret = 0;
 880         int dl, bd_dl;
 881
 882         /* We never set ANC_SUP */
 883         if (cmd->t_task_cdb[1])
 884                 return TCM_INVALID_CDB_FIELD;
 885
 886         if (cmd->data_length == 0) {
 887                 target_complete_cmd(cmd, SAM_STAT_GOOD);
 888                 return 0;
 889         }
 890
 891         if (cmd->data_length < 8) {
 892                 pr_warn("UNMAP parameter list length %u too small\n",
 893                         cmd->data_length);
 894                 return TCM_PARAMETER_LIST_LENGTH_ERROR;
 895         }
 896
 897         buf = transport_kmap_data_sg(cmd);
 898         if (!buf)
 899                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 900
 901         dl = get_unaligned_be16(&buf[0]);
 902         bd_dl = get_unaligned_be16(&buf[2]);
 903
 904         size = cmd->data_length - 8;
 905         if (bd_dl > size)
 906                 pr_warn("UNMAP parameter list length %u too small, ignoring bd_dl %u\n",
 907                         cmd->data_length, bd_dl);
 908         else
 909                 size = bd_dl;
 910
 911         if (size / 16 > dev->dev_attrib.max_unmap_block_desc_count) {
 912                 ret = TCM_INVALID_PARAMETER_LIST;
 913                 goto err;
 914         }
 915
 916         /* First UNMAP block descriptor starts at 8 byte offset */
 917         ptr = &buf[8];
 918         pr_debug("UNMAP: Sub: %s Using dl: %u bd_dl: %u size: %u"
 919                 " ptr: %p\n", dev->transport->name, dl, bd_dl, size, ptr);
 920
 921         while (size >= 16) {
 922                 lba = get_unaligned_be64(&ptr[0]);
 923                 range = get_unaligned_be32(&ptr[8]);
 924                 pr_debug("UNMAP: Using lba: %llu and range: %u\n",
 925                                  (unsigned long long)lba, range);
 926
 927                 if (range > dev->dev_attrib.max_unmap_lba_count) {
 928                         ret = TCM_INVALID_PARAMETER_LIST;
 929                         goto err;
 930                 }
 931
 932                 if (lba + range > dev->transport->get_blocks(dev) + 1) {
 933                         ret = TCM_ADDRESS_OUT_OF_RANGE;
 934                         goto err;
 935                 }
 936
 937                 ret = do_unmap_fn(cmd, priv, lba, range);
 938                 if (ret)
 939                         goto err;
 940
 941                 ptr += 16;
 942                 size -= 16;
 943         }
 944
 945 err:
 946         transport_kunmap_data_sg(cmd);
 947         if (!ret)
 948                 target_complete_cmd(cmd, GOOD);
 949         return ret;
 950 }
 951 EXPORT_SYMBOL(sbc_execute_unmap);