drivers/target/iscsi/iscsi_target_erl0.c

   1 /******************************************************************************
   2  * This file contains error recovery level zero functions used by
   3  * the iSCSI Target driver.
   4  *
   5  * (c) Copyright 2007-2013 Datera, Inc.
   6  *
   7  * Author: Nicholas A. Bellinger <nab@linux-iscsi.org>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  ******************************************************************************/
  19
  20 #include <linux/sched/signal.h>
  21
  22 #include <scsi/iscsi_proto.h>
  23 #include <target/target_core_base.h>
  24 #include <target/target_core_fabric.h>
  25
  26 #include <target/iscsi/iscsi_target_core.h>
  27 #include "iscsi_target_seq_pdu_list.h"
  28 #include "iscsi_target_erl0.h"
  29 #include "iscsi_target_erl1.h"
  30 #include "iscsi_target_erl2.h"
  31 #include "iscsi_target_util.h"
  32 #include "iscsi_target.h"
  33
  34 /*
  35  *      Used to set values in struct iscsi_cmd that iscsit_dataout_check_sequence()
  36  *      checks against to determine a PDU's Offset+Length is within the current
  37  *      DataOUT Sequence.  Used for DataSequenceInOrder=Yes only.
  38  */
  39 void iscsit_set_dataout_sequence_values(
  40         struct iscsi_cmd *cmd)
  41 {
  42         struct iscsi_conn *conn = cmd->conn;
  43         /*
  44          * Still set seq_start_offset and seq_end_offset for Unsolicited
  45          * DataOUT, even if DataSequenceInOrder=No.
  46          */
  47         if (cmd->unsolicited_data) {
  48                 cmd->seq_start_offset = cmd->write_data_done;
  49                 cmd->seq_end_offset = min(cmd->se_cmd.data_length,
  50                                         conn->sess->sess_ops->FirstBurstLength);
  51                 return;
  52         }
  53
  54         if (!conn->sess->sess_ops->DataSequenceInOrder)
  55                 return;
  56
  57         if (!cmd->seq_start_offset && !cmd->seq_end_offset) {
  58                 cmd->seq_start_offset = cmd->write_data_done;
  59                 cmd->seq_end_offset = (cmd->se_cmd.data_length >
  60                         conn->sess->sess_ops->MaxBurstLength) ?
  61                         (cmd->write_data_done +
  62                         conn->sess->sess_ops->MaxBurstLength) : cmd->se_cmd.data_length;
  63         } else {
  64                 cmd->seq_start_offset = cmd->seq_end_offset;
  65                 cmd->seq_end_offset = ((cmd->seq_end_offset +
  66                         conn->sess->sess_ops->MaxBurstLength) >=
  67                         cmd->se_cmd.data_length) ? cmd->se_cmd.data_length :
  68                         (cmd->seq_end_offset +
  69                          conn->sess->sess_ops->MaxBurstLength);
  70         }
  71 }
  72
  73 static int iscsit_dataout_within_command_recovery_check(
  74         struct iscsi_cmd *cmd,
  75         unsigned char *buf)
  76 {
  77         struct iscsi_conn *conn = cmd->conn;
  78         struct iscsi_data *hdr = (struct iscsi_data *) buf;
  79         u32 payload_length = ntoh24(hdr->dlength);
  80
  81         /*
  82          * We do the within-command recovery checks here as it is
  83          * the first function called in iscsi_check_pre_dataout().
  84          * Basically, if we are in within-command recovery and
  85          * the PDU does not contain the offset the sequence needs,
  86          * dump the payload.
  87          *
  88          * This only applies to DataPDUInOrder=Yes, for
  89          * DataPDUInOrder=No we only re-request the failed PDU
  90          * and check that all PDUs in a sequence are received
  91          * upon end of sequence.
  92          */
  93         if (conn->sess->sess_ops->DataSequenceInOrder) {
  94                 if ((cmd->cmd_flags & ICF_WITHIN_COMMAND_RECOVERY) &&
  95                     cmd->write_data_done != be32_to_cpu(hdr->offset))
  96                         goto dump;
  97
  98                 cmd->cmd_flags &= ~ICF_WITHIN_COMMAND_RECOVERY;
  99         } else {
 100                 struct iscsi_seq *seq;
 101
 102                 seq = iscsit_get_seq_holder(cmd, be32_to_cpu(hdr->offset),
 103                                             payload_length);
 104                 if (!seq)
 105                         return DATAOUT_CANNOT_RECOVER;
 106                 /*
 107                  * Set the struct iscsi_seq pointer to reuse later.
 108                  */
 109                 cmd->seq_ptr = seq;
 110
 111                 if (conn->sess->sess_ops->DataPDUInOrder) {
 112                         if (seq->status ==
 113                             DATAOUT_SEQUENCE_WITHIN_COMMAND_RECOVERY &&
 114                            (seq->offset != be32_to_cpu(hdr->offset) ||
 115                             seq->data_sn != be32_to_cpu(hdr->datasn)))
 116                                 goto dump;
 117                 } else {
 118                         if (seq->status ==
 119                              DATAOUT_SEQUENCE_WITHIN_COMMAND_RECOVERY &&
 120                             seq->data_sn != be32_to_cpu(hdr->datasn))
 121                                 goto dump;
 122                 }
 123
 124                 if (seq->status == DATAOUT_SEQUENCE_COMPLETE)
 125                         goto dump;
 126
 127                 if (seq->status != DATAOUT_SEQUENCE_COMPLETE)
 128                         seq->status = 0;
 129         }
 130
 131         return DATAOUT_NORMAL;
 132
 133 dump:
 134         pr_err("Dumping DataOUT PDU Offset: %u Length: %d DataSN:"
 135                 " 0x%08x\n", hdr->offset, payload_length, hdr->datasn);
 136         return iscsit_dump_data_payload(conn, payload_length, 1);
 137 }
 138
 139 static int iscsit_dataout_check_unsolicited_sequence(
 140         struct iscsi_cmd *cmd,
 141         unsigned char *buf)
 142 {
 143         u32 first_burst_len;
 144         struct iscsi_conn *conn = cmd->conn;
 145         struct iscsi_data *hdr = (struct iscsi_data *) buf;
 146         u32 payload_length = ntoh24(hdr->dlength);
 147
 148
 149         if ((be32_to_cpu(hdr->offset) < cmd->seq_start_offset) ||
 150            ((be32_to_cpu(hdr->offset) + payload_length) > cmd->seq_end_offset)) {
 151                 pr_err("Command ITT: 0x%08x with Offset: %u,"
 152                 " Length: %u outside of Unsolicited Sequence %u:%u while"
 153                 " DataSequenceInOrder=Yes.\n", cmd->init_task_tag,
 154                 be32_to_cpu(hdr->offset), payload_length, cmd->seq_start_offset,
 155                         cmd->seq_end_offset);
 156                 return DATAOUT_CANNOT_RECOVER;
 157         }
 158
 159         first_burst_len = (cmd->first_burst_len + payload_length);
 160
 161         if (first_burst_len > conn->sess->sess_ops->FirstBurstLength) {
 162                 pr_err("Total %u bytes exceeds FirstBurstLength: %u"
 163                         " for this Unsolicited DataOut Burst.\n",
 164                         first_burst_len, conn->sess->sess_ops->FirstBurstLength);
 165                 transport_send_check_condition_and_sense(&cmd->se_cmd,
 166                                 TCM_INCORRECT_AMOUNT_OF_DATA, 0);
 167                 return DATAOUT_CANNOT_RECOVER;
 168         }
 169
 170         /*
 171          * Perform various MaxBurstLength and ISCSI_FLAG_CMD_FINAL sanity
 172          * checks for the current Unsolicited DataOUT Sequence.
 173          */
 174         if (hdr->flags & ISCSI_FLAG_CMD_FINAL) {
 175                 /*
 176                  * Ignore ISCSI_FLAG_CMD_FINAL checks while DataPDUInOrder=No, end of
 177                  * sequence checks are handled in
 178                  * iscsit_dataout_datapduinorder_no_fbit().
 179                  */
 180                 if (!conn->sess->sess_ops->DataPDUInOrder)
 181                         goto out;
 182
 183                 if ((first_burst_len != cmd->se_cmd.data_length) &&
 184                     (first_burst_len != conn->sess->sess_ops->FirstBurstLength)) {
 185                         pr_err("Unsolicited non-immediate data"
 186                         " received %u does not equal FirstBurstLength: %u, and"
 187                         " does not equal ExpXferLen %u.\n", first_burst_len,
 188                                 conn->sess->sess_ops->FirstBurstLength,
 189                                 cmd->se_cmd.data_length);
 190                         transport_send_check_condition_and_sense(&cmd->se_cmd,
 191                                         TCM_INCORRECT_AMOUNT_OF_DATA, 0);
 192                         return DATAOUT_CANNOT_RECOVER;
 193                 }
 194         } else {
 195                 if (first_burst_len == conn->sess->sess_ops->FirstBurstLength) {
 196                         pr_err("Command ITT: 0x%08x reached"
 197                         " FirstBurstLength: %u, but ISCSI_FLAG_CMD_FINAL is not set. protocol"
 198                                 " error.\n", cmd->init_task_tag,
 199                                 conn->sess->sess_ops->FirstBurstLength);
 200                         return DATAOUT_CANNOT_RECOVER;
 201                 }
 202                 if (first_burst_len == cmd->se_cmd.data_length) {
 203                         pr_err("Command ITT: 0x%08x reached"
 204                         " ExpXferLen: %u, but ISCSI_FLAG_CMD_FINAL is not set. protocol"
 205                         " error.\n", cmd->init_task_tag, cmd->se_cmd.data_length);
 206                         return DATAOUT_CANNOT_RECOVER;
 207                 }
 208         }
 209
 210 out:
 211         return DATAOUT_NORMAL;
 212 }
 213
 214 static int iscsit_dataout_check_sequence(
 215         struct iscsi_cmd *cmd,
 216         unsigned char *buf)
 217 {
 218         u32 next_burst_len;
 219         struct iscsi_conn *conn = cmd->conn;
 220         struct iscsi_seq *seq = NULL;
 221         struct iscsi_data *hdr = (struct iscsi_data *) buf;
 222         u32 payload_length = ntoh24(hdr->dlength);
 223
 224         /*
 225          * For DataSequenceInOrder=Yes: Check that the offset and offset+length
 226          * is within range as defined by iscsi_set_dataout_sequence_values().
 227          *
 228          * For DataSequenceInOrder=No: Check that an struct iscsi_seq exists for
 229          * offset+length tuple.
 230          */
 231         if (conn->sess->sess_ops->DataSequenceInOrder) {
 232                 /*
 233                  * Due to possibility of recovery DataOUT sent by the initiator
 234                  * fullfilling an Recovery R2T, it's best to just dump the
 235                  * payload here, instead of erroring out.
 236                  */
 237                 if ((be32_to_cpu(hdr->offset) < cmd->seq_start_offset) ||
 238                    ((be32_to_cpu(hdr->offset) + payload_length) > cmd->seq_end_offset)) {
 239                         pr_err("Command ITT: 0x%08x with Offset: %u,"
 240                         " Length: %u outside of Sequence %u:%u while"
 241                         " DataSequenceInOrder=Yes.\n", cmd->init_task_tag,
 242                         be32_to_cpu(hdr->offset), payload_length, cmd->seq_start_offset,
 243                                 cmd->seq_end_offset);
 244
 245                         if (iscsit_dump_data_payload(conn, payload_length, 1) < 0)
 246                                 return DATAOUT_CANNOT_RECOVER;
 247                         return DATAOUT_WITHIN_COMMAND_RECOVERY;
 248                 }
 249
 250                 next_burst_len = (cmd->next_burst_len + payload_length);
 251         } else {
 252                 seq = iscsit_get_seq_holder(cmd, be32_to_cpu(hdr->offset),
 253                                             payload_length);
 254                 if (!seq)
 255                         return DATAOUT_CANNOT_RECOVER;
 256                 /*
 257                  * Set the struct iscsi_seq pointer to reuse later.
 258                  */
 259                 cmd->seq_ptr = seq;
 260
 261                 if (seq->status == DATAOUT_SEQUENCE_COMPLETE) {
 262                         if (iscsit_dump_data_payload(conn, payload_length, 1) < 0)
 263                                 return DATAOUT_CANNOT_RECOVER;
 264                         return DATAOUT_WITHIN_COMMAND_RECOVERY;
 265                 }
 266
 267                 next_burst_len = (seq->next_burst_len + payload_length);
 268         }
 269
 270         if (next_burst_len > conn->sess->sess_ops->MaxBurstLength) {
 271                 pr_err("Command ITT: 0x%08x, NextBurstLength: %u and"
 272                         " Length: %u exceeds MaxBurstLength: %u. protocol"
 273                         " error.\n", cmd->init_task_tag,
 274                         (next_burst_len - payload_length),
 275                         payload_length, conn->sess->sess_ops->MaxBurstLength);
 276                 return DATAOUT_CANNOT_RECOVER;
 277         }
 278
 279         /*
 280          * Perform various MaxBurstLength and ISCSI_FLAG_CMD_FINAL sanity
 281          * checks for the current DataOUT Sequence.
 282          */
 283         if (hdr->flags & ISCSI_FLAG_CMD_FINAL) {
 284                 /*
 285                  * Ignore ISCSI_FLAG_CMD_FINAL checks while DataPDUInOrder=No, end of
 286                  * sequence checks are handled in
 287                  * iscsit_dataout_datapduinorder_no_fbit().
 288                  */
 289                 if (!conn->sess->sess_ops->DataPDUInOrder)
 290                         goto out;
 291
 292                 if (conn->sess->sess_ops->DataSequenceInOrder) {
 293                         if ((next_burst_len <
 294                              conn->sess->sess_ops->MaxBurstLength) &&
 295                            ((cmd->write_data_done + payload_length) <
 296                              cmd->se_cmd.data_length)) {
 297                                 pr_err("Command ITT: 0x%08x set ISCSI_FLAG_CMD_FINAL"
 298                                 " before end of DataOUT sequence, protocol"
 299                                 " error.\n", cmd->init_task_tag);
 300                                 return DATAOUT_CANNOT_RECOVER;
 301                         }
 302                 } else {
 303                         if (next_burst_len < seq->xfer_len) {
 304                                 pr_err("Command ITT: 0x%08x set ISCSI_FLAG_CMD_FINAL"
 305                                 " before end of DataOUT sequence, protocol"
 306                                 " error.\n", cmd->init_task_tag);
 307                                 return DATAOUT_CANNOT_RECOVER;
 308                         }
 309                 }
 310         } else {
 311                 if (conn->sess->sess_ops->DataSequenceInOrder) {
 312                         if (next_burst_len ==
 313                                         conn->sess->sess_ops->MaxBurstLength) {
 314                                 pr_err("Command ITT: 0x%08x reached"
 315                                 " MaxBurstLength: %u, but ISCSI_FLAG_CMD_FINAL is"
 316                                 " not set, protocol error.", cmd->init_task_tag,
 317                                         conn->sess->sess_ops->MaxBurstLength);
 318                                 return DATAOUT_CANNOT_RECOVER;
 319                         }
 320                         if ((cmd->write_data_done + payload_length) ==
 321                                         cmd->se_cmd.data_length) {
 322                                 pr_err("Command ITT: 0x%08x reached"
 323                                 " last DataOUT PDU in sequence but ISCSI_FLAG_"
 324                                 "CMD_FINAL is not set, protocol error.\n",
 325                                         cmd->init_task_tag);
 326                                 return DATAOUT_CANNOT_RECOVER;
 327                         }
 328                 } else {
 329                         if (next_burst_len == seq->xfer_len) {
 330                                 pr_err("Command ITT: 0x%08x reached"
 331                                 " last DataOUT PDU in sequence but ISCSI_FLAG_"
 332                                 "CMD_FINAL is not set, protocol error.\n",
 333                                         cmd->init_task_tag);
 334                                 return DATAOUT_CANNOT_RECOVER;
 335                         }
 336                 }
 337         }
 338
 339 out:
 340         return DATAOUT_NORMAL;
 341 }
 342
 343 static int iscsit_dataout_check_datasn(
 344         struct iscsi_cmd *cmd,
 345         unsigned char *buf)
 346 {
 347         u32 data_sn = 0;
 348         struct iscsi_conn *conn = cmd->conn;
 349         struct iscsi_data *hdr = (struct iscsi_data *) buf;
 350         u32 payload_length = ntoh24(hdr->dlength);
 351
 352         /*
 353          * Considering the target has no method of re-requesting DataOUT
 354          * by DataSN, if we receieve a greater DataSN than expected we
 355          * assume the functions for DataPDUInOrder=[Yes,No] below will
 356          * handle it.
 357          *
 358          * If the DataSN is less than expected, dump the payload.
 359          */
 360         if (conn->sess->sess_ops->DataSequenceInOrder)
 361                 data_sn = cmd->data_sn;
 362         else {
 363                 struct iscsi_seq *seq = cmd->seq_ptr;
 364                 data_sn = seq->data_sn;
 365         }
 366
 367         if (be32_to_cpu(hdr->datasn) > data_sn) {
 368                 pr_err("Command ITT: 0x%08x, received DataSN: 0x%08x"
 369                         " higher than expected 0x%08x.\n", cmd->init_task_tag,
 370                                 be32_to_cpu(hdr->datasn), data_sn);
 371                 goto recover;
 372         } else if (be32_to_cpu(hdr->datasn) < data_sn) {
 373                 pr_err("Command ITT: 0x%08x, received DataSN: 0x%08x"
 374                         " lower than expected 0x%08x, discarding payload.\n",
 375                         cmd->init_task_tag, be32_to_cpu(hdr->datasn), data_sn);
 376                 goto dump;
 377         }
 378
 379         return DATAOUT_NORMAL;
 380
 381 recover:
 382         if (!conn->sess->sess_ops->ErrorRecoveryLevel) {
 383                 pr_err("Unable to perform within-command recovery"
 384                                 " while ERL=0.\n");
 385                 return DATAOUT_CANNOT_RECOVER;
 386         }
 387 dump:
 388         if (iscsit_dump_data_payload(conn, payload_length, 1) < 0)
 389                 return DATAOUT_CANNOT_RECOVER;
 390
 391         return DATAOUT_WITHIN_COMMAND_RECOVERY;
 392 }
 393
 394 static int iscsit_dataout_pre_datapduinorder_yes(
 395         struct iscsi_cmd *cmd,
 396         unsigned char *buf)
 397 {
 398         int dump = 0, recovery = 0;
 399         struct iscsi_conn *conn = cmd->conn;
 400         struct iscsi_data *hdr = (struct iscsi_data *) buf;
 401         u32 payload_length = ntoh24(hdr->dlength);
 402
 403         /*
 404          * For DataSequenceInOrder=Yes: If the offset is greater than the global
 405          * DataPDUInOrder=Yes offset counter in struct iscsi_cmd a protcol error has
 406          * occurred and fail the connection.
 407          *
 408          * For DataSequenceInOrder=No: If the offset is greater than the per
 409          * sequence DataPDUInOrder=Yes offset counter in struct iscsi_seq a protocol
 410          * error has occurred and fail the connection.
 411          */
 412         if (conn->sess->sess_ops->DataSequenceInOrder) {
 413                 if (be32_to_cpu(hdr->offset) != cmd->write_data_done) {
 414                         pr_err("Command ITT: 0x%08x, received offset"
 415                         " %u different than expected %u.\n", cmd->init_task_tag,
 416                                 be32_to_cpu(hdr->offset), cmd->write_data_done);
 417                         recovery = 1;
 418                         goto recover;
 419                 }
 420         } else {
 421                 struct iscsi_seq *seq = cmd->seq_ptr;
 422
 423                 if (be32_to_cpu(hdr->offset) > seq->offset) {
 424                         pr_err("Command ITT: 0x%08x, received offset"
 425                         " %u greater than expected %u.\n", cmd->init_task_tag,
 426                                 be32_to_cpu(hdr->offset), seq->offset);
 427                         recovery = 1;
 428                         goto recover;
 429                 } else if (be32_to_cpu(hdr->offset) < seq->offset) {
 430                         pr_err("Command ITT: 0x%08x, received offset"
 431                         " %u less than expected %u, discarding payload.\n",
 432                                 cmd->init_task_tag, be32_to_cpu(hdr->offset),
 433                                 seq->offset);
 434                         dump = 1;
 435                         goto dump;
 436                 }
 437         }
 438
 439         return DATAOUT_NORMAL;
 440
 441 recover:
 442         if (!conn->sess->sess_ops->ErrorRecoveryLevel) {
 443                 pr_err("Unable to perform within-command recovery"
 444                                 " while ERL=0.\n");
 445                 return DATAOUT_CANNOT_RECOVER;
 446         }
 447 dump:
 448         if (iscsit_dump_data_payload(conn, payload_length, 1) < 0)
 449                 return DATAOUT_CANNOT_RECOVER;
 450
 451         return (recovery) ? iscsit_recover_dataout_sequence(cmd,
 452                 be32_to_cpu(hdr->offset), payload_length) :
 453                (dump) ? DATAOUT_WITHIN_COMMAND_RECOVERY : DATAOUT_NORMAL;
 454 }
 455
 456 static int iscsit_dataout_pre_datapduinorder_no(
 457         struct iscsi_cmd *cmd,
 458         unsigned char *buf)
 459 {
 460         struct iscsi_pdu *pdu;
 461         struct iscsi_data *hdr = (struct iscsi_data *) buf;
 462         u32 payload_length = ntoh24(hdr->dlength);
 463
 464         pdu = iscsit_get_pdu_holder(cmd, be32_to_cpu(hdr->offset),
 465                                     payload_length);
 466         if (!pdu)
 467                 return DATAOUT_CANNOT_RECOVER;
 468
 469         cmd->pdu_ptr = pdu;
 470
 471         switch (pdu->status) {
 472         case ISCSI_PDU_NOT_RECEIVED:
 473         case ISCSI_PDU_CRC_FAILED:
 474         case ISCSI_PDU_TIMED_OUT:
 475                 break;
 476         case ISCSI_PDU_RECEIVED_OK:
 477                 pr_err("Command ITT: 0x%08x received already gotten"
 478                         " Offset: %u, Length: %u\n", cmd->init_task_tag,
 479                                 be32_to_cpu(hdr->offset), payload_length);
 480                 return iscsit_dump_data_payload(cmd->conn, payload_length, 1);
 481         default:
 482                 return DATAOUT_CANNOT_RECOVER;
 483         }
 484
 485         return DATAOUT_NORMAL;
 486 }
 487
 488 static int iscsit_dataout_update_r2t(struct iscsi_cmd *cmd, u32 offset, u32 length)
 489 {
 490         struct iscsi_r2t *r2t;
 491
 492         if (cmd->unsolicited_data)
 493                 return 0;
 494
 495         r2t = iscsit_get_r2t_for_eos(cmd, offset, length);
 496         if (!r2t)
 497                 return -1;
 498
 499         spin_lock_bh(&cmd->r2t_lock);
 500         r2t->seq_complete = 1;
 501         cmd->outstanding_r2ts--;
 502         spin_unlock_bh(&cmd->r2t_lock);
 503
 504         return 0;
 505 }
 506
 507 static int iscsit_dataout_update_datapduinorder_no(
 508         struct iscsi_cmd *cmd,
 509         u32 data_sn,
 510         int f_bit)
 511 {
 512         int ret = 0;
 513         struct iscsi_pdu *pdu = cmd->pdu_ptr;
 514
 515         pdu->data_sn = data_sn;
 516
 517         switch (pdu->status) {
 518         case ISCSI_PDU_NOT_RECEIVED:
 519                 pdu->status = ISCSI_PDU_RECEIVED_OK;
 520                 break;
 521         case ISCSI_PDU_CRC_FAILED:
 522                 pdu->status = ISCSI_PDU_RECEIVED_OK;
 523                 break;
 524         case ISCSI_PDU_TIMED_OUT:
 525                 pdu->status = ISCSI_PDU_RECEIVED_OK;
 526                 break;
 527         default:
 528                 return DATAOUT_CANNOT_RECOVER;
 529         }
 530
 531         if (f_bit) {
 532                 ret = iscsit_dataout_datapduinorder_no_fbit(cmd, pdu);
 533                 if (ret == DATAOUT_CANNOT_RECOVER)
 534                         return ret;
 535         }
 536
 537         return DATAOUT_NORMAL;
 538 }
 539
 540 static int iscsit_dataout_post_crc_passed(
 541         struct iscsi_cmd *cmd,
 542         unsigned char *buf)
 543 {
 544         int ret, send_r2t = 0;
 545         struct iscsi_conn *conn = cmd->conn;
 546         struct iscsi_seq *seq = NULL;
 547         struct iscsi_data *hdr = (struct iscsi_data *) buf;
 548         u32 payload_length = ntoh24(hdr->dlength);
 549
 550         if (cmd->unsolicited_data) {
 551                 if ((cmd->first_burst_len + payload_length) ==
 552                      conn->sess->sess_ops->FirstBurstLength) {
 553                         if (iscsit_dataout_update_r2t(cmd, be32_to_cpu(hdr->offset),
 554                                         payload_length) < 0)
 555                                 return DATAOUT_CANNOT_RECOVER;
 556                         send_r2t = 1;
 557                 }
 558
 559                 if (!conn->sess->sess_ops->DataPDUInOrder) {
 560                         ret = iscsit_dataout_update_datapduinorder_no(cmd,
 561                                 be32_to_cpu(hdr->datasn),
 562                                 (hdr->flags & ISCSI_FLAG_CMD_FINAL));
 563                         if (ret == DATAOUT_CANNOT_RECOVER)
 564                                 return ret;
 565                 }
 566
 567                 cmd->first_burst_len += payload_length;
 568
 569                 if (conn->sess->sess_ops->DataSequenceInOrder)
 570                         cmd->data_sn++;
 571                 else {
 572                         seq = cmd->seq_ptr;
 573                         seq->data_sn++;
 574                         seq->offset += payload_length;
 575                 }
 576
 577                 if (send_r2t) {
 578                         if (seq)
 579                                 seq->status = DATAOUT_SEQUENCE_COMPLETE;
 580                         cmd->first_burst_len = 0;
 581                         cmd->unsolicited_data = 0;
 582                 }
 583         } else {
 584                 if (conn->sess->sess_ops->DataSequenceInOrder) {
 585                         if ((cmd->next_burst_len + payload_length) ==
 586                              conn->sess->sess_ops->MaxBurstLength) {
 587                                 if (iscsit_dataout_update_r2t(cmd,
 588                                                 be32_to_cpu(hdr->offset),
 589                                                 payload_length) < 0)
 590                                         return DATAOUT_CANNOT_RECOVER;
 591                                 send_r2t = 1;
 592                         }
 593
 594                         if (!conn->sess->sess_ops->DataPDUInOrder) {
 595                                 ret = iscsit_dataout_update_datapduinorder_no(
 596                                                 cmd, be32_to_cpu(hdr->datasn),
 597                                                 (hdr->flags & ISCSI_FLAG_CMD_FINAL));
 598                                 if (ret == DATAOUT_CANNOT_RECOVER)
 599                                         return ret;
 600                         }
 601
 602                         cmd->next_burst_len += payload_length;
 603                         cmd->data_sn++;
 604
 605                         if (send_r2t)
 606                                 cmd->next_burst_len = 0;
 607                 } else {
 608                         seq = cmd->seq_ptr;
 609
 610                         if ((seq->next_burst_len + payload_length) ==
 611                              seq->xfer_len) {
 612                                 if (iscsit_dataout_update_r2t(cmd,
 613                                                 be32_to_cpu(hdr->offset),
 614                                                 payload_length) < 0)
 615                                         return DATAOUT_CANNOT_RECOVER;
 616                                 send_r2t = 1;
 617                         }
 618
 619                         if (!conn->sess->sess_ops->DataPDUInOrder) {
 620                                 ret = iscsit_dataout_update_datapduinorder_no(
 621                                                 cmd, be32_to_cpu(hdr->datasn),
 622                                                 (hdr->flags & ISCSI_FLAG_CMD_FINAL));
 623                                 if (ret == DATAOUT_CANNOT_RECOVER)
 624                                         return ret;
 625                         }
 626
 627                         seq->data_sn++;
 628                         seq->offset += payload_length;
 629                         seq->next_burst_len += payload_length;
 630
 631                         if (send_r2t) {
 632                                 seq->next_burst_len = 0;
 633                                 seq->status = DATAOUT_SEQUENCE_COMPLETE;
 634                         }
 635                 }
 636         }
 637
 638         if (send_r2t && conn->sess->sess_ops->DataSequenceInOrder)
 639                 cmd->data_sn = 0;
 640
 641         cmd->write_data_done += payload_length;
 642
 643         if (cmd->write_data_done == cmd->se_cmd.data_length)
 644                 return DATAOUT_SEND_TO_TRANSPORT;
 645         else if (send_r2t)
 646                 return DATAOUT_SEND_R2T;
 647         else
 648                 return DATAOUT_NORMAL;
 649 }
 650
 651 static int iscsit_dataout_post_crc_failed(
 652         struct iscsi_cmd *cmd,
 653         unsigned char *buf)
 654 {
 655         struct iscsi_conn *conn = cmd->conn;
 656         struct iscsi_pdu *pdu;
 657         struct iscsi_data *hdr = (struct iscsi_data *) buf;
 658         u32 payload_length = ntoh24(hdr->dlength);
 659
 660         if (conn->sess->sess_ops->DataPDUInOrder)
 661                 goto recover;
 662         /*
 663          * The rest of this function is only called when DataPDUInOrder=No.
 664          */
 665         pdu = cmd->pdu_ptr;
 666
 667         switch (pdu->status) {
 668         case ISCSI_PDU_NOT_RECEIVED:
 669                 pdu->status = ISCSI_PDU_CRC_FAILED;
 670                 break;
 671         case ISCSI_PDU_CRC_FAILED:
 672                 break;
 673         case ISCSI_PDU_TIMED_OUT:
 674                 pdu->status = ISCSI_PDU_CRC_FAILED;
 675                 break;
 676         default:
 677                 return DATAOUT_CANNOT_RECOVER;
 678         }
 679
 680 recover:
 681         return iscsit_recover_dataout_sequence(cmd, be32_to_cpu(hdr->offset),
 682                                                 payload_length);
 683 }
 684
 685 /*
 686  *      Called from iscsit_handle_data_out() before DataOUT Payload is received
 687  *      and CRC computed.
 688  */
 689 int iscsit_check_pre_dataout(
 690         struct iscsi_cmd *cmd,
 691         unsigned char *buf)
 692 {
 693         int ret;
 694         struct iscsi_conn *conn = cmd->conn;
 695
 696         ret = iscsit_dataout_within_command_recovery_check(cmd, buf);
 697         if ((ret == DATAOUT_WITHIN_COMMAND_RECOVERY) ||
 698             (ret == DATAOUT_CANNOT_RECOVER))
 699                 return ret;
 700
 701         ret = iscsit_dataout_check_datasn(cmd, buf);
 702         if ((ret == DATAOUT_WITHIN_COMMAND_RECOVERY) ||
 703             (ret == DATAOUT_CANNOT_RECOVER))
 704                 return ret;
 705
 706         if (cmd->unsolicited_data) {
 707                 ret = iscsit_dataout_check_unsolicited_sequence(cmd, buf);
 708                 if ((ret == DATAOUT_WITHIN_COMMAND_RECOVERY) ||
 709                     (ret == DATAOUT_CANNOT_RECOVER))
 710                         return ret;
 711         } else {
 712                 ret = iscsit_dataout_check_sequence(cmd, buf);
 713                 if ((ret == DATAOUT_WITHIN_COMMAND_RECOVERY) ||
 714                     (ret == DATAOUT_CANNOT_RECOVER))
 715                         return ret;
 716         }
 717
 718         return (conn->sess->sess_ops->DataPDUInOrder) ?
 719                 iscsit_dataout_pre_datapduinorder_yes(cmd, buf) :
 720                 iscsit_dataout_pre_datapduinorder_no(cmd, buf);
 721 }
 722
 723 /*
 724  *      Called from iscsit_handle_data_out() after DataOUT Payload is received
 725  *      and CRC computed.
 726  */
 727 int iscsit_check_post_dataout(
 728         struct iscsi_cmd *cmd,
 729         unsigned char *buf,
 730         u8 data_crc_failed)
 731 {
 732         struct iscsi_conn *conn = cmd->conn;
 733
 734         cmd->dataout_timeout_retries = 0;
 735
 736         if (!data_crc_failed)
 737                 return iscsit_dataout_post_crc_passed(cmd, buf);
 738         else {
 739                 if (!conn->sess->sess_ops->ErrorRecoveryLevel) {
 740                         pr_err("Unable to recover from DataOUT CRC"
 741                                 " failure while ERL=0, closing session.\n");
 742                         iscsit_reject_cmd(cmd, ISCSI_REASON_DATA_DIGEST_ERROR,
 743                                           buf);
 744                         return DATAOUT_CANNOT_RECOVER;
 745                 }
 746
 747                 iscsit_reject_cmd(cmd, ISCSI_REASON_DATA_DIGEST_ERROR, buf);
 748                 return iscsit_dataout_post_crc_failed(cmd, buf);
 749         }
 750 }
 751
 752 void iscsit_handle_time2retain_timeout(struct timer_list *t)
 753 {
 754         struct iscsi_session *sess = from_timer(sess, t, time2retain_timer);
 755         struct iscsi_portal_group *tpg = sess->tpg;
 756         struct se_portal_group *se_tpg = &tpg->tpg_se_tpg;
 757
 758         spin_lock_bh(&se_tpg->session_lock);
 759         if (sess->time2retain_timer_flags & ISCSI_TF_STOP) {
 760                 spin_unlock_bh(&se_tpg->session_lock);
 761                 return;
 762         }
 763         if (atomic_read(&sess->session_reinstatement)) {
 764                 pr_err("Exiting Time2Retain handler because"
 765                                 " session_reinstatement=1\n");
 766                 spin_unlock_bh(&se_tpg->session_lock);
 767                 return;
 768         }
 769         sess->time2retain_timer_flags |= ISCSI_TF_EXPIRED;
 770
 771         pr_err("Time2Retain timer expired for SID: %u, cleaning up"
 772                         " iSCSI session.\n", sess->sid);
 773         {
 774         struct iscsi_tiqn *tiqn = tpg->tpg_tiqn;
 775
 776         if (tiqn) {
 777                 spin_lock(&tiqn->sess_err_stats.lock);
 778                 strcpy(tiqn->sess_err_stats.last_sess_fail_rem_name,
 779                         (void *)sess->sess_ops->InitiatorName);
 780                 tiqn->sess_err_stats.last_sess_failure_type =
 781                                 ISCSI_SESS_ERR_CXN_TIMEOUT;
 782                 tiqn->sess_err_stats.cxn_timeout_errors++;
 783                 atomic_long_inc(&sess->conn_timeout_errors);
 784                 spin_unlock(&tiqn->sess_err_stats.lock);
 785         }
 786         }
 787
 788         spin_unlock_bh(&se_tpg->session_lock);
 789         iscsit_close_session(sess);
 790 }
 791
 792 void iscsit_start_time2retain_handler(struct iscsi_session *sess)
 793 {
 794         int tpg_active;
 795         /*
 796          * Only start Time2Retain timer when the associated TPG is still in
 797          * an ACTIVE (eg: not disabled or shutdown) state.
 798          */
 799         spin_lock(&sess->tpg->tpg_state_lock);
 800         tpg_active = (sess->tpg->tpg_state == TPG_STATE_ACTIVE);
 801         spin_unlock(&sess->tpg->tpg_state_lock);
 802
 803         if (!tpg_active)
 804                 return;
 805
 806         if (sess->time2retain_timer_flags & ISCSI_TF_RUNNING)
 807                 return;
 808
 809         pr_debug("Starting Time2Retain timer for %u seconds on"
 810                 " SID: %u\n", sess->sess_ops->DefaultTime2Retain, sess->sid);
 811
 812         sess->time2retain_timer_flags &= ~ISCSI_TF_STOP;
 813         sess->time2retain_timer_flags |= ISCSI_TF_RUNNING;
 814         mod_timer(&sess->time2retain_timer,
 815                   jiffies + sess->sess_ops->DefaultTime2Retain * HZ);
 816 }
 817
 818 /*
 819  *      Called with spin_lock_bh(&struct se_portal_group->session_lock) held
 820  */
 821 int iscsit_stop_time2retain_timer(struct iscsi_session *sess)
 822 {
 823         struct iscsi_portal_group *tpg = sess->tpg;
 824         struct se_portal_group *se_tpg = &tpg->tpg_se_tpg;
 825
 826         if (sess->time2retain_timer_flags & ISCSI_TF_EXPIRED)
 827                 return -1;
 828
 829         if (!(sess->time2retain_timer_flags & ISCSI_TF_RUNNING))
 830                 return 0;
 831
 832         sess->time2retain_timer_flags |= ISCSI_TF_STOP;
 833         spin_unlock(&se_tpg->session_lock);
 834
 835         del_timer_sync(&sess->time2retain_timer);
 836
 837         spin_lock(&se_tpg->session_lock);
 838         sess->time2retain_timer_flags &= ~ISCSI_TF_RUNNING;
 839         pr_debug("Stopped Time2Retain Timer for SID: %u\n",
 840                         sess->sid);
 841         return 0;
 842 }
 843
 844 void iscsit_connection_reinstatement_rcfr(struct iscsi_conn *conn)
 845 {
 846         spin_lock_bh(&conn->state_lock);
 847         if (atomic_read(&conn->connection_exit)) {
 848                 spin_unlock_bh(&conn->state_lock);
 849                 goto sleep;
 850         }
 851
 852         if (atomic_read(&conn->transport_failed)) {
 853                 spin_unlock_bh(&conn->state_lock);
 854                 goto sleep;
 855         }
 856         spin_unlock_bh(&conn->state_lock);
 857
 858         if (conn->tx_thread && conn->tx_thread_active)
 859                 send_sig(SIGINT, conn->tx_thread, 1);
 860         if (conn->rx_thread && conn->rx_thread_active)
 861                 send_sig(SIGINT, conn->rx_thread, 1);
 862
 863 sleep:
 864         wait_for_completion(&conn->conn_wait_rcfr_comp);
 865         complete(&conn->conn_post_wait_comp);
 866 }
 867
 868 void iscsit_cause_connection_reinstatement(struct iscsi_conn *conn, int sleep)
 869 {
 870         spin_lock_bh(&conn->state_lock);
 871         if (atomic_read(&conn->connection_exit)) {
 872                 spin_unlock_bh(&conn->state_lock);
 873                 return;
 874         }
 875
 876         if (atomic_read(&conn->transport_failed)) {
 877                 spin_unlock_bh(&conn->state_lock);
 878                 return;
 879         }
 880
 881         if (atomic_read(&conn->connection_reinstatement)) {
 882                 spin_unlock_bh(&conn->state_lock);
 883                 return;
 884         }
 885
 886         if (conn->tx_thread && conn->tx_thread_active)
 887                 send_sig(SIGINT, conn->tx_thread, 1);
 888         if (conn->rx_thread && conn->rx_thread_active)
 889                 send_sig(SIGINT, conn->rx_thread, 1);
 890
 891         atomic_set(&conn->connection_reinstatement, 1);
 892         if (!sleep) {
 893                 spin_unlock_bh(&conn->state_lock);
 894                 return;
 895         }
 896
 897         atomic_set(&conn->sleep_on_conn_wait_comp, 1);
 898         spin_unlock_bh(&conn->state_lock);
 899
 900         wait_for_completion(&conn->conn_wait_comp);
 901         complete(&conn->conn_post_wait_comp);
 902 }
 903 EXPORT_SYMBOL(iscsit_cause_connection_reinstatement);
 904
 905 void iscsit_fall_back_to_erl0(struct iscsi_session *sess)
 906 {
 907         pr_debug("Falling back to ErrorRecoveryLevel=0 for SID:"
 908                         " %u\n", sess->sid);
 909
 910         atomic_set(&sess->session_fall_back_to_erl0, 1);
 911 }
 912
 913 static void iscsit_handle_connection_cleanup(struct iscsi_conn *conn)
 914 {
 915         struct iscsi_session *sess = conn->sess;
 916
 917         if ((sess->sess_ops->ErrorRecoveryLevel == 2) &&
 918             !atomic_read(&sess->session_reinstatement) &&
 919             !atomic_read(&sess->session_fall_back_to_erl0))
 920                 iscsit_connection_recovery_transport_reset(conn);
 921         else {
 922                 pr_debug("Performing cleanup for failed iSCSI"
 923                         " Connection ID: %hu from %s\n", conn->cid,
 924                         sess->sess_ops->InitiatorName);
 925                 iscsit_close_connection(conn);
 926         }
 927 }
 928
 929 void iscsit_take_action_for_connection_exit(struct iscsi_conn *conn, bool *conn_freed)
 930 {
 931         *conn_freed = false;
 932
 933         spin_lock_bh(&conn->state_lock);
 934         if (atomic_read(&conn->connection_exit)) {
 935                 spin_unlock_bh(&conn->state_lock);
 936                 return;
 937         }
 938         atomic_set(&conn->connection_exit, 1);
 939
 940         if (conn->conn_state == TARG_CONN_STATE_IN_LOGOUT) {
 941                 spin_unlock_bh(&conn->state_lock);
 942                 iscsit_close_connection(conn);
 943                 *conn_freed = true;
 944                 return;
 945         }
 946
 947         if (conn->conn_state == TARG_CONN_STATE_CLEANUP_WAIT) {
 948                 spin_unlock_bh(&conn->state_lock);
 949                 return;
 950         }
 951
 952         pr_debug("Moving to TARG_CONN_STATE_CLEANUP_WAIT.\n");
 953         conn->conn_state = TARG_CONN_STATE_CLEANUP_WAIT;
 954         spin_unlock_bh(&conn->state_lock);
 955
 956         iscsit_handle_connection_cleanup(conn);
 957         *conn_freed = true;
 958 }