drivers/target/target_core_sbc.c

   1 /*
   2  * SCSI Block Commands (SBC) parsing and emulation.
   3  *
   4  * (c) Copyright 2002-2013 Datera, Inc.
   5  *
   6  * Nicholas A. Bellinger <nab@kernel.org>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  21  */
  22
  23 #include <linux/kernel.h>
  24 #include <linux/module.h>
  25 #include <linux/ratelimit.h>
  26 #include <linux/crc-t10dif.h>
  27 #include <asm/unaligned.h>
  28 #include <scsi/scsi_proto.h>
  29 #include <scsi/scsi_tcq.h>
  30
  31 #include <target/target_core_base.h>
  32 #include <target/target_core_backend.h>
  33 #include <target/target_core_fabric.h>
  34
  35 #include "target_core_internal.h"
  36 #include "target_core_ua.h"
  37 #include "target_core_alua.h"
  38
  39 static sense_reason_t
  40 sbc_check_prot(struct se_device *, struct se_cmd *, unsigned char *, u32, bool);
  41 static sense_reason_t sbc_execute_unmap(struct se_cmd *cmd);
  42
  43 static sense_reason_t
  44 sbc_emulate_readcapacity(struct se_cmd *cmd)
  45 {
  46         struct se_device *dev = cmd->se_dev;
  47         unsigned char *cdb = cmd->t_task_cdb;
  48         unsigned long long blocks_long = dev->transport->get_blocks(dev);
  49         unsigned char *rbuf;
  50         unsigned char buf[8];
  51         u32 blocks;
  52
  53         /*
  54          * SBC-2 says:
  55          *   If the PMI bit is set to zero and the LOGICAL BLOCK
  56          *   ADDRESS field is not set to zero, the device server shall
  57          *   terminate the command with CHECK CONDITION status with
  58          *   the sense key set to ILLEGAL REQUEST and the additional
  59          *   sense code set to INVALID FIELD IN CDB.
  60          *
  61          * In SBC-3, these fields are obsolete, but some SCSI
  62          * compliance tests actually check this, so we might as well
  63          * follow SBC-2.
  64          */
  65         if (!(cdb[8] & 1) && !!(cdb[2] | cdb[3] | cdb[4] | cdb[5]))
  66                 return TCM_INVALID_CDB_FIELD;
  67
  68         if (blocks_long >= 0x00000000ffffffff)
  69                 blocks = 0xffffffff;
  70         else
  71                 blocks = (u32)blocks_long;
  72
  73         buf[0] = (blocks >> 24) & 0xff;
  74         buf[1] = (blocks >> 16) & 0xff;
  75         buf[2] = (blocks >> 8) & 0xff;
  76         buf[3] = blocks & 0xff;
  77         buf[4] = (dev->dev_attrib.block_size >> 24) & 0xff;
  78         buf[5] = (dev->dev_attrib.block_size >> 16) & 0xff;
  79         buf[6] = (dev->dev_attrib.block_size >> 8) & 0xff;
  80         buf[7] = dev->dev_attrib.block_size & 0xff;
  81
  82         rbuf = transport_kmap_data_sg(cmd);
  83         if (rbuf) {
  84                 memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length));
  85                 transport_kunmap_data_sg(cmd);
  86         }
  87
  88         target_complete_cmd_with_length(cmd, GOOD, 8);
  89         return 0;
  90 }
  91
  92 static sense_reason_t
  93 sbc_emulate_readcapacity_16(struct se_cmd *cmd)
  94 {
  95         struct se_device *dev = cmd->se_dev;
  96         struct se_session *sess = cmd->se_sess;
  97         int pi_prot_type = dev->dev_attrib.pi_prot_type;
  98
  99         unsigned char *rbuf;
 100         unsigned char buf[32];
 101         unsigned long long blocks = dev->transport->get_blocks(dev);
 102
 103         memset(buf, 0, sizeof(buf));
 104         buf[0] = (blocks >> 56) & 0xff;
 105         buf[1] = (blocks >> 48) & 0xff;
 106         buf[2] = (blocks >> 40) & 0xff;
 107         buf[3] = (blocks >> 32) & 0xff;
 108         buf[4] = (blocks >> 24) & 0xff;
 109         buf[5] = (blocks >> 16) & 0xff;
 110         buf[6] = (blocks >> 8) & 0xff;
 111         buf[7] = blocks & 0xff;
 112         buf[8] = (dev->dev_attrib.block_size >> 24) & 0xff;
 113         buf[9] = (dev->dev_attrib.block_size >> 16) & 0xff;
 114         buf[10] = (dev->dev_attrib.block_size >> 8) & 0xff;
 115         buf[11] = dev->dev_attrib.block_size & 0xff;
 116         /*
 117          * Set P_TYPE and PROT_EN bits for DIF support
 118          */
 119         if (sess->sup_prot_ops & (TARGET_PROT_DIN_PASS | TARGET_PROT_DOUT_PASS)) {
 120                 /*
 121                  * Only override a device's pi_prot_type if no T10-PI is
 122                  * available, and sess_prot_type has been explicitly enabled.
 123                  */
 124                 if (!pi_prot_type)
 125                         pi_prot_type = sess->sess_prot_type;
 126
 127                 if (pi_prot_type)
 128                         buf[12] = (pi_prot_type - 1) << 1 | 0x1;
 129         }
 130
 131         if (dev->transport->get_lbppbe)
 132                 buf[13] = dev->transport->get_lbppbe(dev) & 0x0f;
 133
 134         if (dev->transport->get_alignment_offset_lbas) {
 135                 u16 lalba = dev->transport->get_alignment_offset_lbas(dev);
 136                 buf[14] = (lalba >> 8) & 0x3f;
 137                 buf[15] = lalba & 0xff;
 138         }
 139
 140         /*
 141          * Set Thin Provisioning Enable bit following sbc3r22 in section
 142          * READ CAPACITY (16) byte 14 if emulate_tpu or emulate_tpws is enabled.
 143          */
 144         if (dev->dev_attrib.emulate_tpu || dev->dev_attrib.emulate_tpws) {
 145                 buf[14] |= 0x80;
 146
 147                 /*
 148                  * LBPRZ signifies that zeroes will be read back from an LBA after
 149                  * an UNMAP or WRITE SAME w/ unmap bit (sbc3r36 5.16.2)
 150                  */
 151                 if (dev->dev_attrib.unmap_zeroes_data)
 152                         buf[14] |= 0x40;
 153         }
 154
 155         rbuf = transport_kmap_data_sg(cmd);
 156         if (rbuf) {
 157                 memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length));
 158                 transport_kunmap_data_sg(cmd);
 159         }
 160
 161         target_complete_cmd_with_length(cmd, GOOD, 32);
 162         return 0;
 163 }
 164
 165 static sense_reason_t
 166 sbc_emulate_startstop(struct se_cmd *cmd)
 167 {
 168         unsigned char *cdb = cmd->t_task_cdb;
 169
 170         /*
 171          * See sbc3r36 section 5.25
 172          * Immediate bit should be set since there is nothing to complete
 173          * POWER CONDITION MODIFIER 0h
 174          */
 175         if (!(cdb[1] & 1) || cdb[2] || cdb[3])
 176                 return TCM_INVALID_CDB_FIELD;
 177
 178         /*
 179          * See sbc3r36 section 5.25
 180          * POWER CONDITION 0h START_VALID - process START and LOEJ
 181          */
 182         if (cdb[4] >> 4 & 0xf)
 183                 return TCM_INVALID_CDB_FIELD;
 184
 185         /*
 186          * See sbc3r36 section 5.25
 187          * LOEJ 0h - nothing to load or unload
 188          * START 1h - we are ready
 189          */
 190         if (!(cdb[4] & 1) || (cdb[4] & 2) || (cdb[4] & 4))
 191                 return TCM_INVALID_CDB_FIELD;
 192
 193         target_complete_cmd(cmd, SAM_STAT_GOOD);
 194         return 0;
 195 }
 196
 197 sector_t sbc_get_write_same_sectors(struct se_cmd *cmd)
 198 {
 199         u32 num_blocks;
 200
 201         if (cmd->t_task_cdb[0] == WRITE_SAME)
 202                 num_blocks = get_unaligned_be16(&cmd->t_task_cdb[7]);
 203         else if (cmd->t_task_cdb[0] == WRITE_SAME_16)
 204                 num_blocks = get_unaligned_be32(&cmd->t_task_cdb[10]);
 205         else /* WRITE_SAME_32 via VARIABLE_LENGTH_CMD */
 206                 num_blocks = get_unaligned_be32(&cmd->t_task_cdb[28]);
 207
 208         /*
 209          * Use the explicit range when non zero is supplied, otherwise calculate
 210          * the remaining range based on ->get_blocks() - starting LBA.
 211          */
 212         if (num_blocks)
 213                 return num_blocks;
 214
 215         return cmd->se_dev->transport->get_blocks(cmd->se_dev) -
 216                 cmd->t_task_lba + 1;
 217 }
 218 EXPORT_SYMBOL(sbc_get_write_same_sectors);
 219
 220 static sense_reason_t
 221 sbc_execute_write_same_unmap(struct se_cmd *cmd)
 222 {
 223         struct sbc_ops *ops = cmd->protocol_data;
 224         sector_t nolb = sbc_get_write_same_sectors(cmd);
 225         sense_reason_t ret;
 226
 227         if (nolb) {
 228                 ret = ops->execute_unmap(cmd, cmd->t_task_lba, nolb);
 229                 if (ret)
 230                         return ret;
 231         }
 232
 233         target_complete_cmd(cmd, GOOD);
 234         return 0;
 235 }
 236
 237 static sense_reason_t
 238 sbc_emulate_noop(struct se_cmd *cmd)
 239 {
 240         target_complete_cmd(cmd, GOOD);
 241         return 0;
 242 }
 243
 244 static inline u32 sbc_get_size(struct se_cmd *cmd, u32 sectors)
 245 {
 246         return cmd->se_dev->dev_attrib.block_size * sectors;
 247 }
 248
 249 static inline u32 transport_get_sectors_6(unsigned char *cdb)
 250 {
 251         /*
 252          * Use 8-bit sector value.  SBC-3 says:
 253          *
 254          *   A TRANSFER LENGTH field set to zero specifies that 256
 255          *   logical blocks shall be written.  Any other value
 256          *   specifies the number of logical blocks that shall be
 257          *   written.
 258          */
 259         return cdb[4] ? : 256;
 260 }
 261
 262 static inline u32 transport_get_sectors_10(unsigned char *cdb)
 263 {
 264         return (u32)(cdb[7] << 8) + cdb[8];
 265 }
 266
 267 static inline u32 transport_get_sectors_12(unsigned char *cdb)
 268 {
 269         return (u32)(cdb[6] << 24) + (cdb[7] << 16) + (cdb[8] << 8) + cdb[9];
 270 }
 271
 272 static inline u32 transport_get_sectors_16(unsigned char *cdb)
 273 {
 274         return (u32)(cdb[10] << 24) + (cdb[11] << 16) +
 275                     (cdb[12] << 8) + cdb[13];
 276 }
 277
 278 /*
 279  * Used for VARIABLE_LENGTH_CDB WRITE_32 and READ_32 variants
 280  */
 281 static inline u32 transport_get_sectors_32(unsigned char *cdb)
 282 {
 283         return (u32)(cdb[28] << 24) + (cdb[29] << 16) +
 284                     (cdb[30] << 8) + cdb[31];
 285
 286 }
 287
 288 static inline u32 transport_lba_21(unsigned char *cdb)
 289 {
 290         return ((cdb[1] & 0x1f) << 16) | (cdb[2] << 8) | cdb[3];
 291 }
 292
 293 static inline u32 transport_lba_32(unsigned char *cdb)
 294 {
 295         return (cdb[2] << 24) | (cdb[3] << 16) | (cdb[4] << 8) | cdb[5];
 296 }
 297
 298 static inline unsigned long long transport_lba_64(unsigned char *cdb)
 299 {
 300         unsigned int __v1, __v2;
 301
 302         __v1 = (cdb[2] << 24) | (cdb[3] << 16) | (cdb[4] << 8) | cdb[5];
 303         __v2 = (cdb[6] << 24) | (cdb[7] << 16) | (cdb[8] << 8) | cdb[9];
 304
 305         return ((unsigned long long)__v2) | (unsigned long long)__v1 << 32;
 306 }
 307
 308 /*
 309  * For VARIABLE_LENGTH_CDB w/ 32 byte extended CDBs
 310  */
 311 static inline unsigned long long transport_lba_64_ext(unsigned char *cdb)
 312 {
 313         unsigned int __v1, __v2;
 314
 315         __v1 = (cdb[12] << 24) | (cdb[13] << 16) | (cdb[14] << 8) | cdb[15];
 316         __v2 = (cdb[16] << 24) | (cdb[17] << 16) | (cdb[18] << 8) | cdb[19];
 317
 318         return ((unsigned long long)__v2) | (unsigned long long)__v1 << 32;
 319 }
 320
 321 static sense_reason_t
 322 sbc_setup_write_same(struct se_cmd *cmd, unsigned char *flags, struct sbc_ops *ops)
 323 {
 324         struct se_device *dev = cmd->se_dev;
 325         sector_t end_lba = dev->transport->get_blocks(dev) + 1;
 326         unsigned int sectors = sbc_get_write_same_sectors(cmd);
 327         sense_reason_t ret;
 328
 329         if ((flags[0] & 0x04) || (flags[0] & 0x02)) {
 330                 pr_err("WRITE_SAME PBDATA and LBDATA"
 331                         " bits not supported for Block Discard"
 332                         " Emulation\n");
 333                 return TCM_UNSUPPORTED_SCSI_OPCODE;
 334         }
 335         if (sectors > cmd->se_dev->dev_attrib.max_write_same_len) {
 336                 pr_warn("WRITE_SAME sectors: %u exceeds max_write_same_len: %u\n",
 337                         sectors, cmd->se_dev->dev_attrib.max_write_same_len);
 338                 return TCM_INVALID_CDB_FIELD;
 339         }
 340         /*
 341          * Sanity check for LBA wrap and request past end of device.
 342          */
 343         if (((cmd->t_task_lba + sectors) < cmd->t_task_lba) ||
 344             ((cmd->t_task_lba + sectors) > end_lba)) {
 345                 pr_err("WRITE_SAME exceeds last lba %llu (lba %llu, sectors %u)\n",
 346                        (unsigned long long)end_lba, cmd->t_task_lba, sectors);
 347                 return TCM_ADDRESS_OUT_OF_RANGE;
 348         }
 349
 350         /* We always have ANC_SUP == 0 so setting ANCHOR is always an error */
 351         if (flags[0] & 0x10) {
 352                 pr_warn("WRITE SAME with ANCHOR not supported\n");
 353                 return TCM_INVALID_CDB_FIELD;
 354         }
 355         /*
 356          * Special case for WRITE_SAME w/ UNMAP=1 that ends up getting
 357          * translated into block discard requests within backend code.
 358          */
 359         if (flags[0] & 0x08) {
 360                 if (!ops->execute_unmap)
 361                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 362
 363                 if (!dev->dev_attrib.emulate_tpws) {
 364                         pr_err("Got WRITE_SAME w/ UNMAP=1, but backend device"
 365                                " has emulate_tpws disabled\n");
 366                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 367                 }
 368                 cmd->execute_cmd = sbc_execute_write_same_unmap;
 369                 return 0;
 370         }
 371         if (!ops->execute_write_same)
 372                 return TCM_UNSUPPORTED_SCSI_OPCODE;
 373
 374         ret = sbc_check_prot(dev, cmd, &cmd->t_task_cdb[0], sectors, true);
 375         if (ret)
 376                 return ret;
 377
 378         cmd->execute_cmd = ops->execute_write_same;
 379         return 0;
 380 }
 381
 382 static sense_reason_t xdreadwrite_callback(struct se_cmd *cmd, bool success,
 383                                            int *post_ret)
 384 {
 385         unsigned char *buf, *addr;
 386         struct scatterlist *sg;
 387         unsigned int offset;
 388         sense_reason_t ret = TCM_NO_SENSE;
 389         int i, count;
 390         /*
 391          * From sbc3r22.pdf section 5.48 XDWRITEREAD (10) command
 392          *
 393          * 1) read the specified logical block(s);
 394          * 2) transfer logical blocks from the data-out buffer;
 395          * 3) XOR the logical blocks transferred from the data-out buffer with
 396          *    the logical blocks read, storing the resulting XOR data in a buffer;
 397          * 4) if the DISABLE WRITE bit is set to zero, then write the logical
 398          *    blocks transferred from the data-out buffer; and
 399          * 5) transfer the resulting XOR data to the data-in buffer.
 400          */
 401         buf = kmalloc(cmd->data_length, GFP_KERNEL);
 402         if (!buf) {
 403                 pr_err("Unable to allocate xor_callback buf\n");
 404                 return TCM_OUT_OF_RESOURCES;
 405         }
 406         /*
 407          * Copy the scatterlist WRITE buffer located at cmd->t_data_sg
 408          * into the locally allocated *buf
 409          */
 410         sg_copy_to_buffer(cmd->t_data_sg,
 411                           cmd->t_data_nents,
 412                           buf,
 413                           cmd->data_length);
 414
 415         /*
 416          * Now perform the XOR against the BIDI read memory located at
 417          * cmd->t_mem_bidi_list
 418          */
 419
 420         offset = 0;
 421         for_each_sg(cmd->t_bidi_data_sg, sg, cmd->t_bidi_data_nents, count) {
 422                 addr = kmap_atomic(sg_page(sg));
 423                 if (!addr) {
 424                         ret = TCM_OUT_OF_RESOURCES;
 425                         goto out;
 426                 }
 427
 428                 for (i = 0; i < sg->length; i++)
 429                         *(addr + sg->offset + i) ^= *(buf + offset + i);
 430
 431                 offset += sg->length;
 432                 kunmap_atomic(addr);
 433         }
 434
 435 out:
 436         kfree(buf);
 437         return ret;
 438 }
 439
 440 static sense_reason_t
 441 sbc_execute_rw(struct se_cmd *cmd)
 442 {
 443         struct sbc_ops *ops = cmd->protocol_data;
 444
 445         return ops->execute_rw(cmd, cmd->t_data_sg, cmd->t_data_nents,
 446                                cmd->data_direction);
 447 }
 448
 449 static sense_reason_t compare_and_write_post(struct se_cmd *cmd, bool success,
 450                                              int *post_ret)
 451 {
 452         struct se_device *dev = cmd->se_dev;
 453
 454         /*
 455          * Only set SCF_COMPARE_AND_WRITE_POST to force a response fall-through
 456          * within target_complete_ok_work() if the command was successfully
 457          * sent to the backend driver.
 458          */
 459         spin_lock_irq(&cmd->t_state_lock);
 460         if ((cmd->transport_state & CMD_T_SENT) && !cmd->scsi_status) {
 461                 cmd->se_cmd_flags |= SCF_COMPARE_AND_WRITE_POST;
 462                 *post_ret = 1;
 463         }
 464         spin_unlock_irq(&cmd->t_state_lock);
 465
 466         /*
 467          * Unlock ->caw_sem originally obtained during sbc_compare_and_write()
 468          * before the original READ I/O submission.
 469          */
 470         up(&dev->caw_sem);
 471
 472         return TCM_NO_SENSE;
 473 }
 474
 475 static sense_reason_t compare_and_write_callback(struct se_cmd *cmd, bool success,
 476                                                  int *post_ret)
 477 {
 478         struct se_device *dev = cmd->se_dev;
 479         struct scatterlist *write_sg = NULL, *sg;
 480         unsigned char *buf = NULL, *addr;
 481         struct sg_mapping_iter m;
 482         unsigned int offset = 0, len;
 483         unsigned int nlbas = cmd->t_task_nolb;
 484         unsigned int block_size = dev->dev_attrib.block_size;
 485         unsigned int compare_len = (nlbas * block_size);
 486         sense_reason_t ret = TCM_NO_SENSE;
 487         int rc, i;
 488
 489         /*
 490          * Handle early failure in transport_generic_request_failure(),
 491          * which will not have taken ->caw_sem yet..
 492          */
 493         if (!success && (!cmd->t_data_sg || !cmd->t_bidi_data_sg))
 494                 return TCM_NO_SENSE;
 495         /*
 496          * Handle special case for zero-length COMPARE_AND_WRITE
 497          */
 498         if (!cmd->data_length)
 499                 goto out;
 500         /*
 501          * Immediately exit + release dev->caw_sem if command has already
 502          * been failed with a non-zero SCSI status.
 503          */
 504         if (cmd->scsi_status) {
 505                 pr_err("compare_and_write_callback: non zero scsi_status:"
 506                         " 0x%02x\n", cmd->scsi_status);
 507                 goto out;
 508         }
 509
 510         buf = kzalloc(cmd->data_length, GFP_KERNEL);
 511         if (!buf) {
 512                 pr_err("Unable to allocate compare_and_write buf\n");
 513                 ret = TCM_OUT_OF_RESOURCES;
 514                 goto out;
 515         }
 516
 517         write_sg = kmalloc(sizeof(struct scatterlist) * cmd->t_data_nents,
 518                            GFP_KERNEL);
 519         if (!write_sg) {
 520                 pr_err("Unable to allocate compare_and_write sg\n");
 521                 ret = TCM_OUT_OF_RESOURCES;
 522                 goto out;
 523         }
 524         sg_init_table(write_sg, cmd->t_data_nents);
 525         /*
 526          * Setup verify and write data payloads from total NumberLBAs.
 527          */
 528         rc = sg_copy_to_buffer(cmd->t_data_sg, cmd->t_data_nents, buf,
 529                                cmd->data_length);
 530         if (!rc) {
 531                 pr_err("sg_copy_to_buffer() failed for compare_and_write\n");
 532                 ret = TCM_OUT_OF_RESOURCES;
 533                 goto out;
 534         }
 535         /*
 536          * Compare against SCSI READ payload against verify payload
 537          */
 538         for_each_sg(cmd->t_bidi_data_sg, sg, cmd->t_bidi_data_nents, i) {
 539                 addr = (unsigned char *)kmap_atomic(sg_page(sg));
 540                 if (!addr) {
 541                         ret = TCM_OUT_OF_RESOURCES;
 542                         goto out;
 543                 }
 544
 545                 len = min(sg->length, compare_len);
 546
 547                 if (memcmp(addr, buf + offset, len)) {
 548                         pr_warn("Detected MISCOMPARE for addr: %p buf: %p\n",
 549                                 addr, buf + offset);
 550                         kunmap_atomic(addr);
 551                         goto miscompare;
 552                 }
 553                 kunmap_atomic(addr);
 554
 555                 offset += len;
 556                 compare_len -= len;
 557                 if (!compare_len)
 558                         break;
 559         }
 560
 561         i = 0;
 562         len = cmd->t_task_nolb * block_size;
 563         sg_miter_start(&m, cmd->t_data_sg, cmd->t_data_nents, SG_MITER_TO_SG);
 564         /*
 565          * Currently assumes NoLB=1 and SGLs are PAGE_SIZE..
 566          */
 567         while (len) {
 568                 sg_miter_next(&m);
 569
 570                 if (block_size < PAGE_SIZE) {
 571                         sg_set_page(&write_sg[i], m.page, block_size,
 572                                     m.piter.sg->offset + block_size);
 573                 } else {
 574                         sg_miter_next(&m);
 575                         sg_set_page(&write_sg[i], m.page, block_size,
 576                                     m.piter.sg->offset);
 577                 }
 578                 len -= block_size;
 579                 i++;
 580         }
 581         sg_miter_stop(&m);
 582         /*
 583          * Save the original SGL + nents values before updating to new
 584          * assignments, to be released in transport_free_pages() ->
 585          * transport_reset_sgl_orig()
 586          */
 587         cmd->t_data_sg_orig = cmd->t_data_sg;
 588         cmd->t_data_sg = write_sg;
 589         cmd->t_data_nents_orig = cmd->t_data_nents;
 590         cmd->t_data_nents = 1;
 591
 592         cmd->sam_task_attr = TCM_HEAD_TAG;
 593         cmd->transport_complete_callback = compare_and_write_post;
 594         /*
 595          * Now reset ->execute_cmd() to the normal sbc_execute_rw() handler
 596          * for submitting the adjusted SGL to write instance user-data.
 597          */
 598         cmd->execute_cmd = sbc_execute_rw;
 599
 600         spin_lock_irq(&cmd->t_state_lock);
 601         cmd->t_state = TRANSPORT_PROCESSING;
 602         cmd->transport_state |= CMD_T_ACTIVE|CMD_T_BUSY|CMD_T_SENT;
 603         spin_unlock_irq(&cmd->t_state_lock);
 604
 605         __target_execute_cmd(cmd, false);
 606
 607         kfree(buf);
 608         return ret;
 609
 610 miscompare:
 611         pr_warn("Target/%s: Send MISCOMPARE check condition and sense\n",
 612                 dev->transport->name);
 613         ret = TCM_MISCOMPARE_VERIFY;
 614 out:
 615         /*
 616          * In the MISCOMPARE or failure case, unlock ->caw_sem obtained in
 617          * sbc_compare_and_write() before the original READ I/O submission.
 618          */
 619         up(&dev->caw_sem);
 620         kfree(write_sg);
 621         kfree(buf);
 622         return ret;
 623 }
 624
 625 static sense_reason_t
 626 sbc_compare_and_write(struct se_cmd *cmd)
 627 {
 628         struct sbc_ops *ops = cmd->protocol_data;
 629         struct se_device *dev = cmd->se_dev;
 630         sense_reason_t ret;
 631         int rc;
 632         /*
 633          * Submit the READ first for COMPARE_AND_WRITE to perform the
 634          * comparision using SGLs at cmd->t_bidi_data_sg..
 635          */
 636         rc = down_interruptible(&dev->caw_sem);
 637         if (rc != 0) {
 638                 cmd->transport_complete_callback = NULL;
 639                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 640         }
 641         /*
 642          * Reset cmd->data_length to individual block_size in order to not
 643          * confuse backend drivers that depend on this value matching the
 644          * size of the I/O being submitted.
 645          */
 646         cmd->data_length = cmd->t_task_nolb * dev->dev_attrib.block_size;
 647
 648         ret = ops->execute_rw(cmd, cmd->t_bidi_data_sg, cmd->t_bidi_data_nents,
 649                               DMA_FROM_DEVICE);
 650         if (ret) {
 651                 cmd->transport_complete_callback = NULL;
 652                 up(&dev->caw_sem);
 653                 return ret;
 654         }
 655         /*
 656          * Unlock of dev->caw_sem to occur in compare_and_write_callback()
 657          * upon MISCOMPARE, or in compare_and_write_done() upon completion
 658          * of WRITE instance user-data.
 659          */
 660         return TCM_NO_SENSE;
 661 }
 662
 663 static int
 664 sbc_set_prot_op_checks(u8 protect, bool fabric_prot, enum target_prot_type prot_type,
 665                        bool is_write, struct se_cmd *cmd)
 666 {
 667         if (is_write) {
 668                 cmd->prot_op = fabric_prot ? TARGET_PROT_DOUT_STRIP :
 669                                protect ? TARGET_PROT_DOUT_PASS :
 670                                TARGET_PROT_DOUT_INSERT;
 671                 switch (protect) {
 672                 case 0x0:
 673                 case 0x3:
 674                         cmd->prot_checks = 0;
 675                         break;
 676                 case 0x1:
 677                 case 0x5:
 678                         cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
 679                         if (prot_type == TARGET_DIF_TYPE1_PROT)
 680                                 cmd->prot_checks |= TARGET_DIF_CHECK_REFTAG;
 681                         break;
 682                 case 0x2:
 683                         if (prot_type == TARGET_DIF_TYPE1_PROT)
 684                                 cmd->prot_checks = TARGET_DIF_CHECK_REFTAG;
 685                         break;
 686                 case 0x4:
 687                         cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
 688                         break;
 689                 default:
 690                         pr_err("Unsupported protect field %d\n", protect);
 691                         return -EINVAL;
 692                 }
 693         } else {
 694                 cmd->prot_op = fabric_prot ? TARGET_PROT_DIN_INSERT :
 695                                protect ? TARGET_PROT_DIN_PASS :
 696                                TARGET_PROT_DIN_STRIP;
 697                 switch (protect) {
 698                 case 0x0:
 699                 case 0x1:
 700                 case 0x5:
 701                         cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
 702                         if (prot_type == TARGET_DIF_TYPE1_PROT)
 703                                 cmd->prot_checks |= TARGET_DIF_CHECK_REFTAG;
 704                         break;
 705                 case 0x2:
 706                         if (prot_type == TARGET_DIF_TYPE1_PROT)
 707                                 cmd->prot_checks = TARGET_DIF_CHECK_REFTAG;
 708                         break;
 709                 case 0x3:
 710                         cmd->prot_checks = 0;
 711                         break;
 712                 case 0x4:
 713                         cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
 714                         break;
 715                 default:
 716                         pr_err("Unsupported protect field %d\n", protect);
 717                         return -EINVAL;
 718                 }
 719         }
 720
 721         return 0;
 722 }
 723
 724 static sense_reason_t
 725 sbc_check_prot(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb,
 726                u32 sectors, bool is_write)
 727 {
 728         u8 protect = cdb[1] >> 5;
 729         int sp_ops = cmd->se_sess->sup_prot_ops;
 730         int pi_prot_type = dev->dev_attrib.pi_prot_type;
 731         bool fabric_prot = false;
 732
 733         if (!cmd->t_prot_sg || !cmd->t_prot_nents) {
 734                 if (unlikely(protect &&
 735                     !dev->dev_attrib.pi_prot_type && !cmd->se_sess->sess_prot_type)) {
 736                         pr_err("CDB contains protect bit, but device + fabric does"
 737                                " not advertise PROTECT=1 feature bit\n");
 738                         return TCM_INVALID_CDB_FIELD;
 739                 }
 740                 if (cmd->prot_pto)
 741                         return TCM_NO_SENSE;
 742         }
 743
 744         switch (dev->dev_attrib.pi_prot_type) {
 745         case TARGET_DIF_TYPE3_PROT:
 746                 cmd->reftag_seed = 0xffffffff;
 747                 break;
 748         case TARGET_DIF_TYPE2_PROT:
 749                 if (protect)
 750                         return TCM_INVALID_CDB_FIELD;
 751
 752                 cmd->reftag_seed = cmd->t_task_lba;
 753                 break;
 754         case TARGET_DIF_TYPE1_PROT:
 755                 cmd->reftag_seed = cmd->t_task_lba;
 756                 break;
 757         case TARGET_DIF_TYPE0_PROT:
 758                 /*
 759                  * See if the fabric supports T10-PI, and the session has been
 760                  * configured to allow export PROTECT=1 feature bit with backend
 761                  * devices that don't support T10-PI.
 762                  */
 763                 fabric_prot = is_write ?
 764                               !!(sp_ops & (TARGET_PROT_DOUT_PASS | TARGET_PROT_DOUT_STRIP)) :
 765                               !!(sp_ops & (TARGET_PROT_DIN_PASS | TARGET_PROT_DIN_INSERT));
 766
 767                 if (fabric_prot && cmd->se_sess->sess_prot_type) {
 768                         pi_prot_type = cmd->se_sess->sess_prot_type;
 769                         break;
 770                 }
 771                 if (!protect)
 772                         return TCM_NO_SENSE;
 773                 /* Fallthrough */
 774         default:
 775                 pr_err("Unable to determine pi_prot_type for CDB: 0x%02x "
 776                        "PROTECT: 0x%02x\n", cdb[0], protect);
 777                 return TCM_INVALID_CDB_FIELD;
 778         }
 779
 780         if (sbc_set_prot_op_checks(protect, fabric_prot, pi_prot_type, is_write, cmd))
 781                 return TCM_INVALID_CDB_FIELD;
 782
 783         cmd->prot_type = pi_prot_type;
 784         cmd->prot_length = dev->prot_length * sectors;
 785
 786         /**
 787          * In case protection information exists over the wire
 788          * we modify command data length to describe pure data.
 789          * The actual transfer length is data length + protection
 790          * length
 791          **/
 792         if (protect)
 793                 cmd->data_length = sectors * dev->dev_attrib.block_size;
 794
 795         pr_debug("%s: prot_type=%d, data_length=%d, prot_length=%d "
 796                  "prot_op=%d prot_checks=%d\n",
 797                  __func__, cmd->prot_type, cmd->data_length, cmd->prot_length,
 798                  cmd->prot_op, cmd->prot_checks);
 799
 800         return TCM_NO_SENSE;
 801 }
 802
 803 static int
 804 sbc_check_dpofua(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb)
 805 {
 806         if (cdb[1] & 0x10) {
 807                 /* see explanation in spc_emulate_modesense */
 808                 if (!target_check_fua(dev)) {
 809                         pr_err("Got CDB: 0x%02x with DPO bit set, but device"
 810                                " does not advertise support for DPO\n", cdb[0]);
 811                         return -EINVAL;
 812                 }
 813         }
 814         if (cdb[1] & 0x8) {
 815                 if (!target_check_fua(dev)) {
 816                         pr_err("Got CDB: 0x%02x with FUA bit set, but device"
 817                                " does not advertise support for FUA write\n",
 818                                cdb[0]);
 819                         return -EINVAL;
 820                 }
 821                 cmd->se_cmd_flags |= SCF_FUA;
 822         }
 823         return 0;
 824 }
 825
 826 sense_reason_t
 827 sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
 828 {
 829         struct se_device *dev = cmd->se_dev;
 830         unsigned char *cdb = cmd->t_task_cdb;
 831         unsigned int size;
 832         u32 sectors = 0;
 833         sense_reason_t ret;
 834
 835         cmd->protocol_data = ops;
 836
 837         switch (cdb[0]) {
 838         case READ_6:
 839                 sectors = transport_get_sectors_6(cdb);
 840                 cmd->t_task_lba = transport_lba_21(cdb);
 841                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 842                 cmd->execute_cmd = sbc_execute_rw;
 843                 break;
 844         case READ_10:
 845                 sectors = transport_get_sectors_10(cdb);
 846                 cmd->t_task_lba = transport_lba_32(cdb);
 847
 848                 if (sbc_check_dpofua(dev, cmd, cdb))
 849                         return TCM_INVALID_CDB_FIELD;
 850
 851                 ret = sbc_check_prot(dev, cmd, cdb, sectors, false);
 852                 if (ret)
 853                         return ret;
 854
 855                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 856                 cmd->execute_cmd = sbc_execute_rw;
 857                 break;
 858         case READ_12:
 859                 sectors = transport_get_sectors_12(cdb);
 860                 cmd->t_task_lba = transport_lba_32(cdb);
 861
 862                 if (sbc_check_dpofua(dev, cmd, cdb))
 863                         return TCM_INVALID_CDB_FIELD;
 864
 865                 ret = sbc_check_prot(dev, cmd, cdb, sectors, false);
 866                 if (ret)
 867                         return ret;
 868
 869                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 870                 cmd->execute_cmd = sbc_execute_rw;
 871                 break;
 872         case READ_16:
 873                 sectors = transport_get_sectors_16(cdb);
 874                 cmd->t_task_lba = transport_lba_64(cdb);
 875
 876                 if (sbc_check_dpofua(dev, cmd, cdb))
 877                         return TCM_INVALID_CDB_FIELD;
 878
 879                 ret = sbc_check_prot(dev, cmd, cdb, sectors, false);
 880                 if (ret)
 881                         return ret;
 882
 883                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 884                 cmd->execute_cmd = sbc_execute_rw;
 885                 break;
 886         case WRITE_6:
 887                 sectors = transport_get_sectors_6(cdb);
 888                 cmd->t_task_lba = transport_lba_21(cdb);
 889                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 890                 cmd->execute_cmd = sbc_execute_rw;
 891                 break;
 892         case WRITE_10:
 893         case WRITE_VERIFY:
 894                 sectors = transport_get_sectors_10(cdb);
 895                 cmd->t_task_lba = transport_lba_32(cdb);
 896
 897                 if (sbc_check_dpofua(dev, cmd, cdb))
 898                         return TCM_INVALID_CDB_FIELD;
 899
 900                 ret = sbc_check_prot(dev, cmd, cdb, sectors, true);
 901                 if (ret)
 902                         return ret;
 903
 904                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 905                 cmd->execute_cmd = sbc_execute_rw;
 906                 break;
 907         case WRITE_12:
 908                 sectors = transport_get_sectors_12(cdb);
 909                 cmd->t_task_lba = transport_lba_32(cdb);
 910
 911                 if (sbc_check_dpofua(dev, cmd, cdb))
 912                         return TCM_INVALID_CDB_FIELD;
 913
 914                 ret = sbc_check_prot(dev, cmd, cdb, sectors, true);
 915                 if (ret)
 916                         return ret;
 917
 918                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 919                 cmd->execute_cmd = sbc_execute_rw;
 920                 break;
 921         case WRITE_16:
 922                 sectors = transport_get_sectors_16(cdb);
 923                 cmd->t_task_lba = transport_lba_64(cdb);
 924
 925                 if (sbc_check_dpofua(dev, cmd, cdb))
 926                         return TCM_INVALID_CDB_FIELD;
 927
 928                 ret = sbc_check_prot(dev, cmd, cdb, sectors, true);
 929                 if (ret)
 930                         return ret;
 931
 932                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 933                 cmd->execute_cmd = sbc_execute_rw;
 934                 break;
 935         case XDWRITEREAD_10:
 936                 if (cmd->data_direction != DMA_TO_DEVICE ||
 937                     !(cmd->se_cmd_flags & SCF_BIDI))
 938                         return TCM_INVALID_CDB_FIELD;
 939                 sectors = transport_get_sectors_10(cdb);
 940
 941                 if (sbc_check_dpofua(dev, cmd, cdb))
 942                         return TCM_INVALID_CDB_FIELD;
 943
 944                 cmd->t_task_lba = transport_lba_32(cdb);
 945                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 946
 947                 /*
 948                  * Setup BIDI XOR callback to be run after I/O completion.
 949                  */
 950                 cmd->execute_cmd = sbc_execute_rw;
 951                 cmd->transport_complete_callback = &xdreadwrite_callback;
 952                 break;
 953         case VARIABLE_LENGTH_CMD:
 954         {
 955                 u16 service_action = get_unaligned_be16(&cdb[8]);
 956                 switch (service_action) {
 957                 case XDWRITEREAD_32:
 958                         sectors = transport_get_sectors_32(cdb);
 959
 960                         if (sbc_check_dpofua(dev, cmd, cdb))
 961                                 return TCM_INVALID_CDB_FIELD;
 962                         /*
 963                          * Use WRITE_32 and READ_32 opcodes for the emulated
 964                          * XDWRITE_READ_32 logic.
 965                          */
 966                         cmd->t_task_lba = transport_lba_64_ext(cdb);
 967                         cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 968
 969                         /*
 970                          * Setup BIDI XOR callback to be run during after I/O
 971                          * completion.
 972                          */
 973                         cmd->execute_cmd = sbc_execute_rw;
 974                         cmd->transport_complete_callback = &xdreadwrite_callback;
 975                         break;
 976                 case WRITE_SAME_32:
 977                         sectors = transport_get_sectors_32(cdb);
 978                         if (!sectors) {
 979                                 pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not"
 980                                        " supported\n");
 981                                 return TCM_INVALID_CDB_FIELD;
 982                         }
 983
 984                         size = sbc_get_size(cmd, 1);
 985                         cmd->t_task_lba = get_unaligned_be64(&cdb[12]);
 986
 987                         ret = sbc_setup_write_same(cmd, &cdb[10], ops);
 988                         if (ret)
 989                                 return ret;
 990                         break;
 991                 default:
 992                         pr_err("VARIABLE_LENGTH_CMD service action"
 993                                 " 0x%04x not supported\n", service_action);
 994                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 995                 }
 996                 break;
 997         }
 998         case COMPARE_AND_WRITE:
 999                 sectors = cdb[13];
1000                 /*
1001                  * Currently enforce COMPARE_AND_WRITE for a single sector
1002                  */
1003                 if (sectors > 1) {
1004                         pr_err("COMPARE_AND_WRITE contains NoLB: %u greater"
1005                                " than 1\n", sectors);
1006                         return TCM_INVALID_CDB_FIELD;
1007                 }
1008                 if (sbc_check_dpofua(dev, cmd, cdb))
1009                         return TCM_INVALID_CDB_FIELD;
1010
1011                 /*
1012                  * Double size because we have two buffers, note that
1013                  * zero is not an error..
1014                  */
1015                 size = 2 * sbc_get_size(cmd, sectors);
1016                 cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
1017                 cmd->t_task_nolb = sectors;
1018                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB | SCF_COMPARE_AND_WRITE;
1019                 cmd->execute_cmd = sbc_compare_and_write;
1020                 cmd->transport_complete_callback = compare_and_write_callback;
1021                 break;
1022         case READ_CAPACITY:
1023                 size = READ_CAP_LEN;
1024                 cmd->execute_cmd = sbc_emulate_readcapacity;
1025                 break;
1026         case SERVICE_ACTION_IN_16:
1027                 switch (cmd->t_task_cdb[1] & 0x1f) {
1028                 case SAI_READ_CAPACITY_16:
1029                         cmd->execute_cmd = sbc_emulate_readcapacity_16;
1030                         break;
1031                 case SAI_REPORT_REFERRALS:
1032                         cmd->execute_cmd = target_emulate_report_referrals;
1033                         break;
1034                 default:
1035                         pr_err("Unsupported SA: 0x%02x\n",
1036                                 cmd->t_task_cdb[1] & 0x1f);
1037                         return TCM_INVALID_CDB_FIELD;
1038                 }
1039                 size = (cdb[10] << 24) | (cdb[11] << 16) |
1040                        (cdb[12] << 8) | cdb[13];
1041                 break;
1042         case SYNCHRONIZE_CACHE:
1043         case SYNCHRONIZE_CACHE_16:
1044                 if (cdb[0] == SYNCHRONIZE_CACHE) {
1045                         sectors = transport_get_sectors_10(cdb);
1046                         cmd->t_task_lba = transport_lba_32(cdb);
1047                 } else {
1048                         sectors = transport_get_sectors_16(cdb);
1049                         cmd->t_task_lba = transport_lba_64(cdb);
1050                 }
1051                 if (ops->execute_sync_cache) {
1052                         cmd->execute_cmd = ops->execute_sync_cache;
1053                         goto check_lba;
1054                 }
1055                 size = 0;
1056                 cmd->execute_cmd = sbc_emulate_noop;
1057                 break;
1058         case UNMAP:
1059                 if (!ops->execute_unmap)
1060                         return TCM_UNSUPPORTED_SCSI_OPCODE;
1061
1062                 if (!dev->dev_attrib.emulate_tpu) {
1063                         pr_err("Got UNMAP, but backend device has"
1064                                " emulate_tpu disabled\n");
1065                         return TCM_UNSUPPORTED_SCSI_OPCODE;
1066                 }
1067                 size = get_unaligned_be16(&cdb[7]);
1068                 cmd->execute_cmd = sbc_execute_unmap;
1069                 break;
1070         case WRITE_SAME_16:
1071                 sectors = transport_get_sectors_16(cdb);
1072                 if (!sectors) {
1073                         pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
1074                         return TCM_INVALID_CDB_FIELD;
1075                 }
1076
1077                 size = sbc_get_size(cmd, 1);
1078                 cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
1079
1080                 ret = sbc_setup_write_same(cmd, &cdb[1], ops);
1081                 if (ret)
1082                         return ret;
1083                 break;
1084         case WRITE_SAME:
1085                 sectors = transport_get_sectors_10(cdb);
1086                 if (!sectors) {
1087                         pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
1088                         return TCM_INVALID_CDB_FIELD;
1089                 }
1090
1091                 size = sbc_get_size(cmd, 1);
1092                 cmd->t_task_lba = get_unaligned_be32(&cdb[2]);
1093
1094                 /*
1095                  * Follow sbcr26 with WRITE_SAME (10) and check for the existence
1096                  * of byte 1 bit 3 UNMAP instead of original reserved field
1097                  */
1098                 ret = sbc_setup_write_same(cmd, &cdb[1], ops);
1099                 if (ret)
1100                         return ret;
1101                 break;
1102         case VERIFY:
1103                 size = 0;
1104                 sectors = transport_get_sectors_10(cdb);
1105                 cmd->t_task_lba = transport_lba_32(cdb);
1106                 cmd->execute_cmd = sbc_emulate_noop;
1107                 goto check_lba;
1108         case REZERO_UNIT:
1109         case SEEK_6:
1110         case SEEK_10:
1111                 /*
1112                  * There are still clients out there which use these old SCSI-2
1113                  * commands. This mainly happens when running VMs with legacy
1114                  * guest systems, connected via SCSI command pass-through to
1115                  * iSCSI targets. Make them happy and return status GOOD.
1116                  */
1117                 size = 0;
1118                 cmd->execute_cmd = sbc_emulate_noop;
1119                 break;
1120         case START_STOP:
1121                 size = 0;
1122                 cmd->execute_cmd = sbc_emulate_startstop;
1123                 break;
1124         default:
1125                 ret = spc_parse_cdb(cmd, &size);
1126                 if (ret)
1127                         return ret;
1128         }
1129
1130         /* reject any command that we don't have a handler for */
1131         if (!cmd->execute_cmd)
1132                 return TCM_UNSUPPORTED_SCSI_OPCODE;
1133
1134         if (cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
1135                 unsigned long long end_lba;
1136 check_lba:
1137                 end_lba = dev->transport->get_blocks(dev) + 1;
1138                 if (((cmd->t_task_lba + sectors) < cmd->t_task_lba) ||
1139                     ((cmd->t_task_lba + sectors) > end_lba)) {
1140                         pr_err("cmd exceeds last lba %llu "
1141                                 "(lba %llu, sectors %u)\n",
1142                                 end_lba, cmd->t_task_lba, sectors);
1143                         return TCM_ADDRESS_OUT_OF_RANGE;
1144                 }
1145
1146                 if (!(cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE))
1147                         size = sbc_get_size(cmd, sectors);
1148         }
1149
1150         return target_cmd_size_check(cmd, size);
1151 }
1152 EXPORT_SYMBOL(sbc_parse_cdb);
1153
1154 u32 sbc_get_device_type(struct se_device *dev)
1155 {
1156         return TYPE_DISK;
1157 }
1158 EXPORT_SYMBOL(sbc_get_device_type);
1159
1160 static sense_reason_t
1161 sbc_execute_unmap(struct se_cmd *cmd)
1162 {
1163         struct sbc_ops *ops = cmd->protocol_data;
1164         struct se_device *dev = cmd->se_dev;
1165         unsigned char *buf, *ptr = NULL;
1166         sector_t lba;
1167         int size;
1168         u32 range;
1169         sense_reason_t ret = 0;
1170         int dl, bd_dl;
1171
1172         /* We never set ANC_SUP */
1173         if (cmd->t_task_cdb[1])
1174                 return TCM_INVALID_CDB_FIELD;
1175
1176         if (cmd->data_length == 0) {
1177                 target_complete_cmd(cmd, SAM_STAT_GOOD);
1178                 return 0;
1179         }
1180
1181         if (cmd->data_length < 8) {
1182                 pr_warn("UNMAP parameter list length %u too small\n",
1183                         cmd->data_length);
1184                 return TCM_PARAMETER_LIST_LENGTH_ERROR;
1185         }
1186
1187         buf = transport_kmap_data_sg(cmd);
1188         if (!buf)
1189                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1190
1191         dl = get_unaligned_be16(&buf[0]);
1192         bd_dl = get_unaligned_be16(&buf[2]);
1193
1194         size = cmd->data_length - 8;
1195         if (bd_dl > size)
1196                 pr_warn("UNMAP parameter list length %u too small, ignoring bd_dl %u\n",
1197                         cmd->data_length, bd_dl);
1198         else
1199                 size = bd_dl;
1200
1201         if (size / 16 > dev->dev_attrib.max_unmap_block_desc_count) {
1202                 ret = TCM_INVALID_PARAMETER_LIST;
1203                 goto err;
1204         }
1205
1206         /* First UNMAP block descriptor starts at 8 byte offset */
1207         ptr = &buf[8];
1208         pr_debug("UNMAP: Sub: %s Using dl: %u bd_dl: %u size: %u"
1209                 " ptr: %p\n", dev->transport->name, dl, bd_dl, size, ptr);
1210
1211         while (size >= 16) {
1212                 lba = get_unaligned_be64(&ptr[0]);
1213                 range = get_unaligned_be32(&ptr[8]);
1214                 pr_debug("UNMAP: Using lba: %llu and range: %u\n",
1215                                  (unsigned long long)lba, range);
1216
1217                 if (range > dev->dev_attrib.max_unmap_lba_count) {
1218                         ret = TCM_INVALID_PARAMETER_LIST;
1219                         goto err;
1220                 }
1221
1222                 if (lba + range > dev->transport->get_blocks(dev) + 1) {
1223                         ret = TCM_ADDRESS_OUT_OF_RANGE;
1224                         goto err;
1225                 }
1226
1227                 ret = ops->execute_unmap(cmd, lba, range);
1228                 if (ret)
1229                         goto err;
1230
1231                 ptr += 16;
1232                 size -= 16;
1233         }
1234
1235 err:
1236         transport_kunmap_data_sg(cmd);
1237         if (!ret)
1238                 target_complete_cmd(cmd, GOOD);
1239         return ret;
1240 }
1241
1242 void
1243 sbc_dif_generate(struct se_cmd *cmd)
1244 {
1245         struct se_device *dev = cmd->se_dev;
1246         struct t10_pi_tuple *sdt;
1247         struct scatterlist *dsg = cmd->t_data_sg, *psg;
1248         sector_t sector = cmd->t_task_lba;
1249         void *daddr, *paddr;
1250         int i, j, offset = 0;
1251         unsigned int block_size = dev->dev_attrib.block_size;
1252
1253         for_each_sg(cmd->t_prot_sg, psg, cmd->t_prot_nents, i) {
1254                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1255                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1256
1257                 for (j = 0; j < psg->length;
1258                                 j += sizeof(*sdt)) {
1259                         __u16 crc;
1260                         unsigned int avail;
1261
1262                         if (offset >= dsg->length) {
1263                                 offset -= dsg->length;
1264                                 kunmap_atomic(daddr - dsg->offset);
1265                                 dsg = sg_next(dsg);
1266                                 if (!dsg) {
1267                                         kunmap_atomic(paddr - psg->offset);
1268                                         return;
1269                                 }
1270                                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1271                         }
1272
1273                         sdt = paddr + j;
1274                         avail = min(block_size, dsg->length - offset);
1275                         crc = crc_t10dif(daddr + offset, avail);
1276                         if (avail < block_size) {
1277                                 kunmap_atomic(daddr - dsg->offset);
1278                                 dsg = sg_next(dsg);
1279                                 if (!dsg) {
1280                                         kunmap_atomic(paddr - psg->offset);
1281                                         return;
1282                                 }
1283                                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1284                                 offset = block_size - avail;
1285                                 crc = crc_t10dif_update(crc, daddr, offset);
1286                         } else {
1287                                 offset += block_size;
1288                         }
1289
1290                         sdt->guard_tag = cpu_to_be16(crc);
1291                         if (cmd->prot_type == TARGET_DIF_TYPE1_PROT)
1292                                 sdt->ref_tag = cpu_to_be32(sector & 0xffffffff);
1293                         sdt->app_tag = 0;
1294
1295                         pr_debug("DIF %s INSERT sector: %llu guard_tag: 0x%04x"
1296                                  " app_tag: 0x%04x ref_tag: %u\n",
1297                                  (cmd->data_direction == DMA_TO_DEVICE) ?
1298                                  "WRITE" : "READ", (unsigned long long)sector,
1299                                  sdt->guard_tag, sdt->app_tag,
1300                                  be32_to_cpu(sdt->ref_tag));
1301
1302                         sector++;
1303                 }
1304
1305                 kunmap_atomic(daddr - dsg->offset);
1306                 kunmap_atomic(paddr - psg->offset);
1307         }
1308 }
1309
1310 static sense_reason_t
1311 sbc_dif_v1_verify(struct se_cmd *cmd, struct t10_pi_tuple *sdt,
1312                   __u16 crc, sector_t sector, unsigned int ei_lba)
1313 {
1314         __be16 csum;
1315
1316         if (!(cmd->prot_checks & TARGET_DIF_CHECK_GUARD))
1317                 goto check_ref;
1318
1319         csum = cpu_to_be16(crc);
1320
1321         if (sdt->guard_tag != csum) {
1322                 pr_err("DIFv1 checksum failed on sector %llu guard tag 0x%04x"
1323                         " csum 0x%04x\n", (unsigned long long)sector,
1324                         be16_to_cpu(sdt->guard_tag), be16_to_cpu(csum));
1325                 return TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED;
1326         }
1327
1328 check_ref:
1329         if (!(cmd->prot_checks & TARGET_DIF_CHECK_REFTAG))
1330                 return 0;
1331
1332         if (cmd->prot_type == TARGET_DIF_TYPE1_PROT &&
1333             be32_to_cpu(sdt->ref_tag) != (sector & 0xffffffff)) {
1334                 pr_err("DIFv1 Type 1 reference failed on sector: %llu tag: 0x%08x"
1335                        " sector MSB: 0x%08x\n", (unsigned long long)sector,
1336                        be32_to_cpu(sdt->ref_tag), (u32)(sector & 0xffffffff));
1337                 return TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;
1338         }
1339
1340         if (cmd->prot_type == TARGET_DIF_TYPE2_PROT &&
1341             be32_to_cpu(sdt->ref_tag) != ei_lba) {
1342                 pr_err("DIFv1 Type 2 reference failed on sector: %llu tag: 0x%08x"
1343                        " ei_lba: 0x%08x\n", (unsigned long long)sector,
1344                         be32_to_cpu(sdt->ref_tag), ei_lba);
1345                 return TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;
1346         }
1347
1348         return 0;
1349 }
1350
1351 void sbc_dif_copy_prot(struct se_cmd *cmd, unsigned int sectors, bool read,
1352                        struct scatterlist *sg, int sg_off)
1353 {
1354         struct se_device *dev = cmd->se_dev;
1355         struct scatterlist *psg;
1356         void *paddr, *addr;
1357         unsigned int i, len, left;
1358         unsigned int offset = sg_off;
1359
1360         if (!sg)
1361                 return;
1362
1363         left = sectors * dev->prot_length;
1364
1365         for_each_sg(cmd->t_prot_sg, psg, cmd->t_prot_nents, i) {
1366                 unsigned int psg_len, copied = 0;
1367
1368                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1369                 psg_len = min(left, psg->length);
1370                 while (psg_len) {
1371                         len = min(psg_len, sg->length - offset);
1372                         addr = kmap_atomic(sg_page(sg)) + sg->offset + offset;
1373
1374                         if (read)
1375                                 memcpy(paddr + copied, addr, len);
1376                         else
1377                                 memcpy(addr, paddr + copied, len);
1378
1379                         left -= len;
1380                         offset += len;
1381                         copied += len;
1382                         psg_len -= len;
1383
1384                         kunmap_atomic(addr - sg->offset - offset);
1385
1386                         if (offset >= sg->length) {
1387                                 sg = sg_next(sg);
1388                                 offset = 0;
1389                         }
1390                 }
1391                 kunmap_atomic(paddr - psg->offset);
1392         }
1393 }
1394 EXPORT_SYMBOL(sbc_dif_copy_prot);
1395
1396 sense_reason_t
1397 sbc_dif_verify(struct se_cmd *cmd, sector_t start, unsigned int sectors,
1398                unsigned int ei_lba, struct scatterlist *psg, int psg_off)
1399 {
1400         struct se_device *dev = cmd->se_dev;
1401         struct t10_pi_tuple *sdt;
1402         struct scatterlist *dsg = cmd->t_data_sg;
1403         sector_t sector = start;
1404         void *daddr, *paddr;
1405         int i;
1406         sense_reason_t rc;
1407         int dsg_off = 0;
1408         unsigned int block_size = dev->dev_attrib.block_size;
1409
1410         for (; psg && sector < start + sectors; psg = sg_next(psg)) {
1411                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1412                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1413
1414                 for (i = psg_off; i < psg->length &&
1415                                 sector < start + sectors;
1416                                 i += sizeof(*sdt)) {
1417                         __u16 crc;
1418                         unsigned int avail;
1419
1420                         if (dsg_off >= dsg->length) {
1421                                 dsg_off -= dsg->length;
1422                                 kunmap_atomic(daddr - dsg->offset);
1423                                 dsg = sg_next(dsg);
1424                                 if (!dsg) {
1425                                         kunmap_atomic(paddr - psg->offset);
1426                                         return 0;
1427                                 }
1428                                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1429                         }
1430
1431                         sdt = paddr + i;
1432
1433                         pr_debug("DIF READ sector: %llu guard_tag: 0x%04x"
1434                                  " app_tag: 0x%04x ref_tag: %u\n",
1435                                  (unsigned long long)sector, sdt->guard_tag,
1436                                  sdt->app_tag, be32_to_cpu(sdt->ref_tag));
1437
1438                         if (sdt->app_tag == cpu_to_be16(0xffff)) {
1439                                 dsg_off += block_size;
1440                                 goto next;
1441                         }
1442
1443                         avail = min(block_size, dsg->length - dsg_off);
1444                         crc = crc_t10dif(daddr + dsg_off, avail);
1445                         if (avail < block_size) {
1446                                 kunmap_atomic(daddr - dsg->offset);
1447                                 dsg = sg_next(dsg);
1448                                 if (!dsg) {
1449                                         kunmap_atomic(paddr - psg->offset);
1450                                         return 0;
1451                                 }
1452                                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1453                                 dsg_off = block_size - avail;
1454                                 crc = crc_t10dif_update(crc, daddr, dsg_off);
1455                         } else {
1456                                 dsg_off += block_size;
1457                         }
1458
1459                         rc = sbc_dif_v1_verify(cmd, sdt, crc, sector, ei_lba);
1460                         if (rc) {
1461                                 kunmap_atomic(daddr - dsg->offset);
1462                                 kunmap_atomic(paddr - psg->offset);
1463                                 cmd->bad_sector = sector;
1464                                 return rc;
1465                         }
1466 next:
1467                         sector++;
1468                         ei_lba++;
1469                 }
1470
1471                 psg_off = 0;
1472                 kunmap_atomic(daddr - dsg->offset);
1473                 kunmap_atomic(paddr - psg->offset);
1474         }
1475
1476         return 0;
1477 }
1478 EXPORT_SYMBOL(sbc_dif_verify);