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         if (dev->transport->get_lbppbe)
 110                 buf[13] = dev->transport->get_lbppbe(dev) & 0x0f;
 111
 112         if (dev->transport->get_alignment_offset_lbas) {
 113                 u16 lalba = dev->transport->get_alignment_offset_lbas(dev);
 114                 buf[14] = (lalba >> 8) & 0x3f;
 115                 buf[15] = lalba & 0xff;
 116         }
 117
 118         /*
 119          * Set Thin Provisioning Enable bit following sbc3r22 in section
 120          * READ CAPACITY (16) byte 14 if emulate_tpu or emulate_tpws is enabled.
 121          */
 122         if (dev->dev_attrib.emulate_tpu || dev->dev_attrib.emulate_tpws)
 123                 buf[14] |= 0x80;
 124
 125         rbuf = transport_kmap_data_sg(cmd);
 126         if (rbuf) {
 127                 memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length));
 128                 transport_kunmap_data_sg(cmd);
 129         }
 130
 131         target_complete_cmd(cmd, GOOD);
 132         return 0;
 133 }
 134
 135 sector_t sbc_get_write_same_sectors(struct se_cmd *cmd)
 136 {
 137         u32 num_blocks;
 138
 139         if (cmd->t_task_cdb[0] == WRITE_SAME)
 140                 num_blocks = get_unaligned_be16(&cmd->t_task_cdb[7]);
 141         else if (cmd->t_task_cdb[0] == WRITE_SAME_16)
 142                 num_blocks = get_unaligned_be32(&cmd->t_task_cdb[10]);
 143         else /* WRITE_SAME_32 via VARIABLE_LENGTH_CMD */
 144                 num_blocks = get_unaligned_be32(&cmd->t_task_cdb[28]);
 145
 146         /*
 147          * Use the explicit range when non zero is supplied, otherwise calculate
 148          * the remaining range based on ->get_blocks() - starting LBA.
 149          */
 150         if (num_blocks)
 151                 return num_blocks;
 152
 153         return cmd->se_dev->transport->get_blocks(cmd->se_dev) -
 154                 cmd->t_task_lba + 1;
 155 }
 156 EXPORT_SYMBOL(sbc_get_write_same_sectors);
 157
 158 static sense_reason_t
 159 sbc_emulate_noop(struct se_cmd *cmd)
 160 {
 161         target_complete_cmd(cmd, GOOD);
 162         return 0;
 163 }
 164
 165 static inline u32 sbc_get_size(struct se_cmd *cmd, u32 sectors)
 166 {
 167         return cmd->se_dev->dev_attrib.block_size * sectors;
 168 }
 169
 170 static int sbc_check_valid_sectors(struct se_cmd *cmd)
 171 {
 172         struct se_device *dev = cmd->se_dev;
 173         unsigned long long end_lba;
 174         u32 sectors;
 175
 176         sectors = cmd->data_length / dev->dev_attrib.block_size;
 177         end_lba = dev->transport->get_blocks(dev) + 1;
 178
 179         if (cmd->t_task_lba + sectors > end_lba) {
 180                 pr_err("target: lba %llu, sectors %u exceeds end lba %llu\n",
 181                         cmd->t_task_lba, sectors, end_lba);
 182                 return -EINVAL;
 183         }
 184
 185         return 0;
 186 }
 187
 188 static inline u32 transport_get_sectors_6(unsigned char *cdb)
 189 {
 190         /*
 191          * Use 8-bit sector value.  SBC-3 says:
 192          *
 193          *   A TRANSFER LENGTH field set to zero specifies that 256
 194          *   logical blocks shall be written.  Any other value
 195          *   specifies the number of logical blocks that shall be
 196          *   written.
 197          */
 198         return cdb[4] ? : 256;
 199 }
 200
 201 static inline u32 transport_get_sectors_10(unsigned char *cdb)
 202 {
 203         return (u32)(cdb[7] << 8) + cdb[8];
 204 }
 205
 206 static inline u32 transport_get_sectors_12(unsigned char *cdb)
 207 {
 208         return (u32)(cdb[6] << 24) + (cdb[7] << 16) + (cdb[8] << 8) + cdb[9];
 209 }
 210
 211 static inline u32 transport_get_sectors_16(unsigned char *cdb)
 212 {
 213         return (u32)(cdb[10] << 24) + (cdb[11] << 16) +
 214                     (cdb[12] << 8) + cdb[13];
 215 }
 216
 217 /*
 218  * Used for VARIABLE_LENGTH_CDB WRITE_32 and READ_32 variants
 219  */
 220 static inline u32 transport_get_sectors_32(unsigned char *cdb)
 221 {
 222         return (u32)(cdb[28] << 24) + (cdb[29] << 16) +
 223                     (cdb[30] << 8) + cdb[31];
 224
 225 }
 226
 227 static inline u32 transport_lba_21(unsigned char *cdb)
 228 {
 229         return ((cdb[1] & 0x1f) << 16) | (cdb[2] << 8) | cdb[3];
 230 }
 231
 232 static inline u32 transport_lba_32(unsigned char *cdb)
 233 {
 234         return (cdb[2] << 24) | (cdb[3] << 16) | (cdb[4] << 8) | cdb[5];
 235 }
 236
 237 static inline unsigned long long transport_lba_64(unsigned char *cdb)
 238 {
 239         unsigned int __v1, __v2;
 240
 241         __v1 = (cdb[2] << 24) | (cdb[3] << 16) | (cdb[4] << 8) | cdb[5];
 242         __v2 = (cdb[6] << 24) | (cdb[7] << 16) | (cdb[8] << 8) | cdb[9];
 243
 244         return ((unsigned long long)__v2) | (unsigned long long)__v1 << 32;
 245 }
 246
 247 /*
 248  * For VARIABLE_LENGTH_CDB w/ 32 byte extended CDBs
 249  */
 250 static inline unsigned long long transport_lba_64_ext(unsigned char *cdb)
 251 {
 252         unsigned int __v1, __v2;
 253
 254         __v1 = (cdb[12] << 24) | (cdb[13] << 16) | (cdb[14] << 8) | cdb[15];
 255         __v2 = (cdb[16] << 24) | (cdb[17] << 16) | (cdb[18] << 8) | cdb[19];
 256
 257         return ((unsigned long long)__v2) | (unsigned long long)__v1 << 32;
 258 }
 259
 260 static sense_reason_t
 261 sbc_setup_write_same(struct se_cmd *cmd, unsigned char *flags, struct sbc_ops *ops)
 262 {
 263         unsigned int sectors = sbc_get_write_same_sectors(cmd);
 264
 265         if ((flags[0] & 0x04) || (flags[0] & 0x02)) {
 266                 pr_err("WRITE_SAME PBDATA and LBDATA"
 267                         " bits not supported for Block Discard"
 268                         " Emulation\n");
 269                 return TCM_UNSUPPORTED_SCSI_OPCODE;
 270         }
 271         if (sectors > cmd->se_dev->dev_attrib.max_write_same_len) {
 272                 pr_warn("WRITE_SAME sectors: %u exceeds max_write_same_len: %u\n",
 273                         sectors, cmd->se_dev->dev_attrib.max_write_same_len);
 274                 return TCM_INVALID_CDB_FIELD;
 275         }
 276         /* We always have ANC_SUP == 0 so setting ANCHOR is always an error */
 277         if (flags[0] & 0x10) {
 278                 pr_warn("WRITE SAME with ANCHOR not supported\n");
 279                 return TCM_INVALID_CDB_FIELD;
 280         }
 281         /*
 282          * Special case for WRITE_SAME w/ UNMAP=1 that ends up getting
 283          * translated into block discard requests within backend code.
 284          */
 285         if (flags[0] & 0x08) {
 286                 if (!ops->execute_write_same_unmap)
 287                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 288
 289                 cmd->execute_cmd = ops->execute_write_same_unmap;
 290                 return 0;
 291         }
 292         if (!ops->execute_write_same)
 293                 return TCM_UNSUPPORTED_SCSI_OPCODE;
 294
 295         cmd->execute_cmd = ops->execute_write_same;
 296         return 0;
 297 }
 298
 299 static sense_reason_t xdreadwrite_callback(struct se_cmd *cmd)
 300 {
 301         unsigned char *buf, *addr;
 302         struct scatterlist *sg;
 303         unsigned int offset;
 304         sense_reason_t ret = TCM_NO_SENSE;
 305         int i, count;
 306         /*
 307          * From sbc3r22.pdf section 5.48 XDWRITEREAD (10) command
 308          *
 309          * 1) read the specified logical block(s);
 310          * 2) transfer logical blocks from the data-out buffer;
 311          * 3) XOR the logical blocks transferred from the data-out buffer with
 312          *    the logical blocks read, storing the resulting XOR data in a buffer;
 313          * 4) if the DISABLE WRITE bit is set to zero, then write the logical
 314          *    blocks transferred from the data-out buffer; and
 315          * 5) transfer the resulting XOR data to the data-in buffer.
 316          */
 317         buf = kmalloc(cmd->data_length, GFP_KERNEL);
 318         if (!buf) {
 319                 pr_err("Unable to allocate xor_callback buf\n");
 320                 return TCM_OUT_OF_RESOURCES;
 321         }
 322         /*
 323          * Copy the scatterlist WRITE buffer located at cmd->t_data_sg
 324          * into the locally allocated *buf
 325          */
 326         sg_copy_to_buffer(cmd->t_data_sg,
 327                           cmd->t_data_nents,
 328                           buf,
 329                           cmd->data_length);
 330
 331         /*
 332          * Now perform the XOR against the BIDI read memory located at
 333          * cmd->t_mem_bidi_list
 334          */
 335
 336         offset = 0;
 337         for_each_sg(cmd->t_bidi_data_sg, sg, cmd->t_bidi_data_nents, count) {
 338                 addr = kmap_atomic(sg_page(sg));
 339                 if (!addr) {
 340                         ret = TCM_OUT_OF_RESOURCES;
 341                         goto out;
 342                 }
 343
 344                 for (i = 0; i < sg->length; i++)
 345                         *(addr + sg->offset + i) ^= *(buf + offset + i);
 346
 347                 offset += sg->length;
 348                 kunmap_atomic(addr);
 349         }
 350
 351 out:
 352         kfree(buf);
 353         return ret;
 354 }
 355
 356 static sense_reason_t
 357 sbc_execute_rw(struct se_cmd *cmd)
 358 {
 359         return cmd->execute_rw(cmd, cmd->t_data_sg, cmd->t_data_nents,
 360                                cmd->data_direction);
 361 }
 362
 363 static sense_reason_t compare_and_write_post(struct se_cmd *cmd)
 364 {
 365         struct se_device *dev = cmd->se_dev;
 366
 367         /*
 368          * Only set SCF_COMPARE_AND_WRITE_POST to force a response fall-through
 369          * within target_complete_ok_work() if the command was successfully
 370          * sent to the backend driver.
 371          */
 372         spin_lock_irq(&cmd->t_state_lock);
 373         if ((cmd->transport_state & CMD_T_SENT) && !cmd->scsi_status)
 374                 cmd->se_cmd_flags |= SCF_COMPARE_AND_WRITE_POST;
 375         spin_unlock_irq(&cmd->t_state_lock);
 376
 377         /*
 378          * Unlock ->caw_sem originally obtained during sbc_compare_and_write()
 379          * before the original READ I/O submission.
 380          */
 381         up(&dev->caw_sem);
 382
 383         return TCM_NO_SENSE;
 384 }
 385
 386 static sense_reason_t compare_and_write_callback(struct se_cmd *cmd)
 387 {
 388         struct se_device *dev = cmd->se_dev;
 389         struct scatterlist *write_sg = NULL, *sg;
 390         unsigned char *buf = NULL, *addr;
 391         struct sg_mapping_iter m;
 392         unsigned int offset = 0, len;
 393         unsigned int nlbas = cmd->t_task_nolb;
 394         unsigned int block_size = dev->dev_attrib.block_size;
 395         unsigned int compare_len = (nlbas * block_size);
 396         sense_reason_t ret = TCM_NO_SENSE;
 397         int rc, i;
 398
 399         /*
 400          * Handle early failure in transport_generic_request_failure(),
 401          * which will not have taken ->caw_mutex yet..
 402          */
 403         if (!cmd->t_data_sg || !cmd->t_bidi_data_sg)
 404                 return TCM_NO_SENSE;
 405         /*
 406          * Immediately exit + release dev->caw_sem if command has already
 407          * been failed with a non-zero SCSI status.
 408          */
 409         if (cmd->scsi_status) {
 410                 pr_err("compare_and_write_callback: non zero scsi_status:"
 411                         " 0x%02x\n", cmd->scsi_status);
 412                 goto out;
 413         }
 414
 415         buf = kzalloc(cmd->data_length, GFP_KERNEL);
 416         if (!buf) {
 417                 pr_err("Unable to allocate compare_and_write buf\n");
 418                 ret = TCM_OUT_OF_RESOURCES;
 419                 goto out;
 420         }
 421
 422         write_sg = kzalloc(sizeof(struct scatterlist) * cmd->t_data_nents,
 423                            GFP_KERNEL);
 424         if (!write_sg) {
 425                 pr_err("Unable to allocate compare_and_write sg\n");
 426                 ret = TCM_OUT_OF_RESOURCES;
 427                 goto out;
 428         }
 429         /*
 430          * Setup verify and write data payloads from total NumberLBAs.
 431          */
 432         rc = sg_copy_to_buffer(cmd->t_data_sg, cmd->t_data_nents, buf,
 433                                cmd->data_length);
 434         if (!rc) {
 435                 pr_err("sg_copy_to_buffer() failed for compare_and_write\n");
 436                 ret = TCM_OUT_OF_RESOURCES;
 437                 goto out;
 438         }
 439         /*
 440          * Compare against SCSI READ payload against verify payload
 441          */
 442         for_each_sg(cmd->t_bidi_data_sg, sg, cmd->t_bidi_data_nents, i) {
 443                 addr = (unsigned char *)kmap_atomic(sg_page(sg));
 444                 if (!addr) {
 445                         ret = TCM_OUT_OF_RESOURCES;
 446                         goto out;
 447                 }
 448
 449                 len = min(sg->length, compare_len);
 450
 451                 if (memcmp(addr, buf + offset, len)) {
 452                         pr_warn("Detected MISCOMPARE for addr: %p buf: %p\n",
 453                                 addr, buf + offset);
 454                         kunmap_atomic(addr);
 455                         goto miscompare;
 456                 }
 457                 kunmap_atomic(addr);
 458
 459                 offset += len;
 460                 compare_len -= len;
 461                 if (!compare_len)
 462                         break;
 463         }
 464
 465         i = 0;
 466         len = cmd->t_task_nolb * block_size;
 467         sg_miter_start(&m, cmd->t_data_sg, cmd->t_data_nents, SG_MITER_TO_SG);
 468         /*
 469          * Currently assumes NoLB=1 and SGLs are PAGE_SIZE..
 470          */
 471         while (len) {
 472                 sg_miter_next(&m);
 473
 474                 if (block_size < PAGE_SIZE) {
 475                         sg_set_page(&write_sg[i], m.page, block_size,
 476                                     block_size);
 477                 } else {
 478                         sg_miter_next(&m);
 479                         sg_set_page(&write_sg[i], m.page, block_size,
 480                                     0);
 481                 }
 482                 len -= block_size;
 483                 i++;
 484         }
 485         sg_miter_stop(&m);
 486         /*
 487          * Save the original SGL + nents values before updating to new
 488          * assignments, to be released in transport_free_pages() ->
 489          * transport_reset_sgl_orig()
 490          */
 491         cmd->t_data_sg_orig = cmd->t_data_sg;
 492         cmd->t_data_sg = write_sg;
 493         cmd->t_data_nents_orig = cmd->t_data_nents;
 494         cmd->t_data_nents = 1;
 495
 496         cmd->sam_task_attr = MSG_HEAD_TAG;
 497         cmd->transport_complete_callback = compare_and_write_post;
 498         /*
 499          * Now reset ->execute_cmd() to the normal sbc_execute_rw() handler
 500          * for submitting the adjusted SGL to write instance user-data.
 501          */
 502         cmd->execute_cmd = sbc_execute_rw;
 503
 504         spin_lock_irq(&cmd->t_state_lock);
 505         cmd->t_state = TRANSPORT_PROCESSING;
 506         cmd->transport_state |= CMD_T_ACTIVE|CMD_T_BUSY|CMD_T_SENT;
 507         spin_unlock_irq(&cmd->t_state_lock);
 508
 509         __target_execute_cmd(cmd);
 510
 511         kfree(buf);
 512         return ret;
 513
 514 miscompare:
 515         pr_warn("Target/%s: Send MISCOMPARE check condition and sense\n",
 516                 dev->transport->name);
 517         ret = TCM_MISCOMPARE_VERIFY;
 518 out:
 519         /*
 520          * In the MISCOMPARE or failure case, unlock ->caw_sem obtained in
 521          * sbc_compare_and_write() before the original READ I/O submission.
 522          */
 523         up(&dev->caw_sem);
 524         kfree(write_sg);
 525         kfree(buf);
 526         return ret;
 527 }
 528
 529 static sense_reason_t
 530 sbc_compare_and_write(struct se_cmd *cmd)
 531 {
 532         struct se_device *dev = cmd->se_dev;
 533         sense_reason_t ret;
 534         int rc;
 535         /*
 536          * Submit the READ first for COMPARE_AND_WRITE to perform the
 537          * comparision using SGLs at cmd->t_bidi_data_sg..
 538          */
 539         rc = down_interruptible(&dev->caw_sem);
 540         if ((rc != 0) || signal_pending(current)) {
 541                 cmd->transport_complete_callback = NULL;
 542                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 543         }
 544         /*
 545          * Reset cmd->data_length to individual block_size in order to not
 546          * confuse backend drivers that depend on this value matching the
 547          * size of the I/O being submitted.
 548          */
 549         cmd->data_length = cmd->t_task_nolb * dev->dev_attrib.block_size;
 550
 551         ret = cmd->execute_rw(cmd, cmd->t_bidi_data_sg, cmd->t_bidi_data_nents,
 552                               DMA_FROM_DEVICE);
 553         if (ret) {
 554                 cmd->transport_complete_callback = NULL;
 555                 up(&dev->caw_sem);
 556                 return ret;
 557         }
 558         /*
 559          * Unlock of dev->caw_sem to occur in compare_and_write_callback()
 560          * upon MISCOMPARE, or in compare_and_write_done() upon completion
 561          * of WRITE instance user-data.
 562          */
 563         return TCM_NO_SENSE;
 564 }
 565
 566 sense_reason_t
 567 sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
 568 {
 569         struct se_device *dev = cmd->se_dev;
 570         unsigned char *cdb = cmd->t_task_cdb;
 571         unsigned int size;
 572         u32 sectors = 0;
 573         sense_reason_t ret;
 574
 575         switch (cdb[0]) {
 576         case READ_6:
 577                 sectors = transport_get_sectors_6(cdb);
 578                 cmd->t_task_lba = transport_lba_21(cdb);
 579                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 580                 cmd->execute_rw = ops->execute_rw;
 581                 cmd->execute_cmd = sbc_execute_rw;
 582                 break;
 583         case READ_10:
 584                 sectors = transport_get_sectors_10(cdb);
 585                 cmd->t_task_lba = transport_lba_32(cdb);
 586                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 587                 cmd->execute_rw = ops->execute_rw;
 588                 cmd->execute_cmd = sbc_execute_rw;
 589                 break;
 590         case READ_12:
 591                 sectors = transport_get_sectors_12(cdb);
 592                 cmd->t_task_lba = transport_lba_32(cdb);
 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 READ_16:
 598                 sectors = transport_get_sectors_16(cdb);
 599                 cmd->t_task_lba = transport_lba_64(cdb);
 600                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 601                 cmd->execute_rw = ops->execute_rw;
 602                 cmd->execute_cmd = sbc_execute_rw;
 603                 break;
 604         case WRITE_6:
 605                 sectors = transport_get_sectors_6(cdb);
 606                 cmd->t_task_lba = transport_lba_21(cdb);
 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_10:
 612         case WRITE_VERIFY:
 613                 sectors = transport_get_sectors_10(cdb);
 614                 cmd->t_task_lba = transport_lba_32(cdb);
 615                 if (cdb[1] & 0x8)
 616                         cmd->se_cmd_flags |= SCF_FUA;
 617                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 618                 cmd->execute_rw = ops->execute_rw;
 619                 cmd->execute_cmd = sbc_execute_rw;
 620                 break;
 621         case WRITE_12:
 622                 sectors = transport_get_sectors_12(cdb);
 623                 cmd->t_task_lba = transport_lba_32(cdb);
 624                 if (cdb[1] & 0x8)
 625                         cmd->se_cmd_flags |= SCF_FUA;
 626                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 627                 cmd->execute_rw = ops->execute_rw;
 628                 cmd->execute_cmd = sbc_execute_rw;
 629                 break;
 630         case WRITE_16:
 631                 sectors = transport_get_sectors_16(cdb);
 632                 cmd->t_task_lba = transport_lba_64(cdb);
 633                 if (cdb[1] & 0x8)
 634                         cmd->se_cmd_flags |= SCF_FUA;
 635                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 636                 cmd->execute_rw = ops->execute_rw;
 637                 cmd->execute_cmd = sbc_execute_rw;
 638                 break;
 639         case XDWRITEREAD_10:
 640                 if (cmd->data_direction != DMA_TO_DEVICE ||
 641                     !(cmd->se_cmd_flags & SCF_BIDI))
 642                         return TCM_INVALID_CDB_FIELD;
 643                 sectors = transport_get_sectors_10(cdb);
 644
 645                 cmd->t_task_lba = transport_lba_32(cdb);
 646                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 647
 648                 /*
 649                  * Setup BIDI XOR callback to be run after I/O completion.
 650                  */
 651                 cmd->execute_rw = ops->execute_rw;
 652                 cmd->execute_cmd = sbc_execute_rw;
 653                 cmd->transport_complete_callback = &xdreadwrite_callback;
 654                 if (cdb[1] & 0x8)
 655                         cmd->se_cmd_flags |= SCF_FUA;
 656                 break;
 657         case VARIABLE_LENGTH_CMD:
 658         {
 659                 u16 service_action = get_unaligned_be16(&cdb[8]);
 660                 switch (service_action) {
 661                 case XDWRITEREAD_32:
 662                         sectors = transport_get_sectors_32(cdb);
 663
 664                         /*
 665                          * Use WRITE_32 and READ_32 opcodes for the emulated
 666                          * XDWRITE_READ_32 logic.
 667                          */
 668                         cmd->t_task_lba = transport_lba_64_ext(cdb);
 669                         cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 670
 671                         /*
 672                          * Setup BIDI XOR callback to be run during after I/O
 673                          * completion.
 674                          */
 675                         cmd->execute_rw = ops->execute_rw;
 676                         cmd->execute_cmd = sbc_execute_rw;
 677                         cmd->transport_complete_callback = &xdreadwrite_callback;
 678                         if (cdb[1] & 0x8)
 679                                 cmd->se_cmd_flags |= SCF_FUA;
 680                         break;
 681                 case WRITE_SAME_32:
 682                         sectors = transport_get_sectors_32(cdb);
 683                         if (!sectors) {
 684                                 pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not"
 685                                        " supported\n");
 686                                 return TCM_INVALID_CDB_FIELD;
 687                         }
 688
 689                         size = sbc_get_size(cmd, 1);
 690                         cmd->t_task_lba = get_unaligned_be64(&cdb[12]);
 691
 692                         ret = sbc_setup_write_same(cmd, &cdb[10], ops);
 693                         if (ret)
 694                                 return ret;
 695                         break;
 696                 default:
 697                         pr_err("VARIABLE_LENGTH_CMD service action"
 698                                 " 0x%04x not supported\n", service_action);
 699                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 700                 }
 701                 break;
 702         }
 703         case COMPARE_AND_WRITE:
 704                 sectors = cdb[13];
 705                 /*
 706                  * Currently enforce COMPARE_AND_WRITE for a single sector
 707                  */
 708                 if (sectors > 1) {
 709                         pr_err("COMPARE_AND_WRITE contains NoLB: %u greater"
 710                                " than 1\n", sectors);
 711                         return TCM_INVALID_CDB_FIELD;
 712                 }
 713                 /*
 714                  * Double size because we have two buffers, note that
 715                  * zero is not an error..
 716                  */
 717                 size = 2 * sbc_get_size(cmd, sectors);
 718                 cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
 719                 cmd->t_task_nolb = sectors;
 720                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB | SCF_COMPARE_AND_WRITE;
 721                 cmd->execute_rw = ops->execute_rw;
 722                 cmd->execute_cmd = sbc_compare_and_write;
 723                 cmd->transport_complete_callback = compare_and_write_callback;
 724                 break;
 725         case READ_CAPACITY:
 726                 size = READ_CAP_LEN;
 727                 cmd->execute_cmd = sbc_emulate_readcapacity;
 728                 break;
 729         case SERVICE_ACTION_IN:
 730                 switch (cmd->t_task_cdb[1] & 0x1f) {
 731                 case SAI_READ_CAPACITY_16:
 732                         cmd->execute_cmd = sbc_emulate_readcapacity_16;
 733                         break;
 734                 default:
 735                         pr_err("Unsupported SA: 0x%02x\n",
 736                                 cmd->t_task_cdb[1] & 0x1f);
 737                         return TCM_INVALID_CDB_FIELD;
 738                 }
 739                 size = (cdb[10] << 24) | (cdb[11] << 16) |
 740                        (cdb[12] << 8) | cdb[13];
 741                 break;
 742         case SYNCHRONIZE_CACHE:
 743         case SYNCHRONIZE_CACHE_16:
 744                 if (!ops->execute_sync_cache) {
 745                         size = 0;
 746                         cmd->execute_cmd = sbc_emulate_noop;
 747                         break;
 748                 }
 749
 750                 /*
 751                  * Extract LBA and range to be flushed for emulated SYNCHRONIZE_CACHE
 752                  */
 753                 if (cdb[0] == SYNCHRONIZE_CACHE) {
 754                         sectors = transport_get_sectors_10(cdb);
 755                         cmd->t_task_lba = transport_lba_32(cdb);
 756                 } else {
 757                         sectors = transport_get_sectors_16(cdb);
 758                         cmd->t_task_lba = transport_lba_64(cdb);
 759                 }
 760
 761                 size = sbc_get_size(cmd, sectors);
 762
 763                 /*
 764                  * Check to ensure that LBA + Range does not exceed past end of
 765                  * device for IBLOCK and FILEIO ->do_sync_cache() backend calls
 766                  */
 767                 if (cmd->t_task_lba || sectors) {
 768                         if (sbc_check_valid_sectors(cmd) < 0)
 769                                 return TCM_ADDRESS_OUT_OF_RANGE;
 770                 }
 771                 cmd->execute_cmd = ops->execute_sync_cache;
 772                 break;
 773         case UNMAP:
 774                 if (!ops->execute_unmap)
 775                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 776
 777                 size = get_unaligned_be16(&cdb[7]);
 778                 cmd->execute_cmd = ops->execute_unmap;
 779                 break;
 780         case WRITE_SAME_16:
 781                 sectors = transport_get_sectors_16(cdb);
 782                 if (!sectors) {
 783                         pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
 784                         return TCM_INVALID_CDB_FIELD;
 785                 }
 786
 787                 size = sbc_get_size(cmd, 1);
 788                 cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
 789
 790                 ret = sbc_setup_write_same(cmd, &cdb[1], ops);
 791                 if (ret)
 792                         return ret;
 793                 break;
 794         case WRITE_SAME:
 795                 sectors = transport_get_sectors_10(cdb);
 796                 if (!sectors) {
 797                         pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
 798                         return TCM_INVALID_CDB_FIELD;
 799                 }
 800
 801                 size = sbc_get_size(cmd, 1);
 802                 cmd->t_task_lba = get_unaligned_be32(&cdb[2]);
 803
 804                 /*
 805                  * Follow sbcr26 with WRITE_SAME (10) and check for the existence
 806                  * of byte 1 bit 3 UNMAP instead of original reserved field
 807                  */
 808                 ret = sbc_setup_write_same(cmd, &cdb[1], ops);
 809                 if (ret)
 810                         return ret;
 811                 break;
 812         case VERIFY:
 813                 size = 0;
 814                 cmd->execute_cmd = sbc_emulate_noop;
 815                 break;
 816         case REZERO_UNIT:
 817         case SEEK_6:
 818         case SEEK_10:
 819                 /*
 820                  * There are still clients out there which use these old SCSI-2
 821                  * commands. This mainly happens when running VMs with legacy
 822                  * guest systems, connected via SCSI command pass-through to
 823                  * iSCSI targets. Make them happy and return status GOOD.
 824                  */
 825                 size = 0;
 826                 cmd->execute_cmd = sbc_emulate_noop;
 827                 break;
 828         default:
 829                 ret = spc_parse_cdb(cmd, &size);
 830                 if (ret)
 831                         return ret;
 832         }
 833
 834         /* reject any command that we don't have a handler for */
 835         if (!(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) && !cmd->execute_cmd)
 836                 return TCM_UNSUPPORTED_SCSI_OPCODE;
 837
 838         if (cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
 839                 unsigned long long end_lba;
 840
 841                 if (sectors > dev->dev_attrib.fabric_max_sectors) {
 842                         printk_ratelimited(KERN_ERR "SCSI OP %02xh with too"
 843                                 " big sectors %u exceeds fabric_max_sectors:"
 844                                 " %u\n", cdb[0], sectors,
 845                                 dev->dev_attrib.fabric_max_sectors);
 846                         return TCM_INVALID_CDB_FIELD;
 847                 }
 848                 if (sectors > dev->dev_attrib.hw_max_sectors) {
 849                         printk_ratelimited(KERN_ERR "SCSI OP %02xh with too"
 850                                 " big sectors %u exceeds backend hw_max_sectors:"
 851                                 " %u\n", cdb[0], sectors,
 852                                 dev->dev_attrib.hw_max_sectors);
 853                         return TCM_INVALID_CDB_FIELD;
 854                 }
 855
 856                 end_lba = dev->transport->get_blocks(dev) + 1;
 857                 if (cmd->t_task_lba + sectors > end_lba) {
 858                         pr_err("cmd exceeds last lba %llu "
 859                                 "(lba %llu, sectors %u)\n",
 860                                 end_lba, cmd->t_task_lba, sectors);
 861                         return TCM_ADDRESS_OUT_OF_RANGE;
 862                 }
 863
 864                 if (!(cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE))
 865                         size = sbc_get_size(cmd, sectors);
 866         }
 867
 868         return target_cmd_size_check(cmd, size);
 869 }
 870 EXPORT_SYMBOL(sbc_parse_cdb);
 871
 872 u32 sbc_get_device_type(struct se_device *dev)
 873 {
 874         return TYPE_DISK;
 875 }
 876 EXPORT_SYMBOL(sbc_get_device_type);
 877
 878 sense_reason_t
 879 sbc_execute_unmap(struct se_cmd *cmd,
 880         sense_reason_t (*do_unmap_fn)(struct se_cmd *, void *,
 881                                       sector_t, sector_t),
 882         void *priv)
 883 {
 884         struct se_device *dev = cmd->se_dev;
 885         unsigned char *buf, *ptr = NULL;
 886         sector_t lba;
 887         int size;
 888         u32 range;
 889         sense_reason_t ret = 0;
 890         int dl, bd_dl;
 891
 892         /* We never set ANC_SUP */
 893         if (cmd->t_task_cdb[1])
 894                 return TCM_INVALID_CDB_FIELD;
 895
 896         if (cmd->data_length == 0) {
 897                 target_complete_cmd(cmd, SAM_STAT_GOOD);
 898                 return 0;
 899         }
 900
 901         if (cmd->data_length < 8) {
 902                 pr_warn("UNMAP parameter list length %u too small\n",
 903                         cmd->data_length);
 904                 return TCM_PARAMETER_LIST_LENGTH_ERROR;
 905         }
 906
 907         buf = transport_kmap_data_sg(cmd);
 908         if (!buf)
 909                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 910
 911         dl = get_unaligned_be16(&buf[0]);
 912         bd_dl = get_unaligned_be16(&buf[2]);
 913
 914         size = cmd->data_length - 8;
 915         if (bd_dl > size)
 916                 pr_warn("UNMAP parameter list length %u too small, ignoring bd_dl %u\n",
 917                         cmd->data_length, bd_dl);
 918         else
 919                 size = bd_dl;
 920
 921         if (size / 16 > dev->dev_attrib.max_unmap_block_desc_count) {
 922                 ret = TCM_INVALID_PARAMETER_LIST;
 923                 goto err;
 924         }
 925
 926         /* First UNMAP block descriptor starts at 8 byte offset */
 927         ptr = &buf[8];
 928         pr_debug("UNMAP: Sub: %s Using dl: %u bd_dl: %u size: %u"
 929                 " ptr: %p\n", dev->transport->name, dl, bd_dl, size, ptr);
 930
 931         while (size >= 16) {
 932                 lba = get_unaligned_be64(&ptr[0]);
 933                 range = get_unaligned_be32(&ptr[8]);
 934                 pr_debug("UNMAP: Using lba: %llu and range: %u\n",
 935                                  (unsigned long long)lba, range);
 936
 937                 if (range > dev->dev_attrib.max_unmap_lba_count) {
 938                         ret = TCM_INVALID_PARAMETER_LIST;
 939                         goto err;
 940                 }
 941
 942                 if (lba + range > dev->transport->get_blocks(dev) + 1) {
 943                         ret = TCM_ADDRESS_OUT_OF_RANGE;
 944                         goto err;
 945                 }
 946
 947                 ret = do_unmap_fn(cmd, priv, lba, range);
 948                 if (ret)
 949                         goto err;
 950
 951                 ptr += 16;
 952                 size -= 16;
 953         }
 954
 955 err:
 956         transport_kunmap_data_sg(cmd);
 957         if (!ret)
 958                 target_complete_cmd(cmd, GOOD);
 959         return ret;
 960 }
 961 EXPORT_SYMBOL(sbc_execute_unmap);