drivers/target/iscsi/iscsi_target_util.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*******************************************************************************
   3  * This file contains the iSCSI Target specific utility functions.
   4  *
   5  * (c) Copyright 2007-2013 Datera, Inc.
   6  *
   7  * Author: Nicholas A. Bellinger <nab@linux-iscsi.org>
   8  *
   9  ******************************************************************************/
  10
  11 #include <linux/list.h>
  12 #include <linux/sched/signal.h>
  13 #include <net/ipv6.h>         /* ipv6_addr_equal() */
  14 #include <scsi/scsi_tcq.h>
  15 #include <scsi/iscsi_proto.h>
  16 #include <target/target_core_base.h>
  17 #include <target/target_core_fabric.h>
  18 #include <target/iscsi/iscsi_transport.h>
  19
  20 #include <target/iscsi/iscsi_target_core.h>
  21 #include "iscsi_target_parameters.h"
  22 #include "iscsi_target_seq_pdu_list.h"
  23 #include "iscsi_target_datain_values.h"
  24 #include "iscsi_target_erl0.h"
  25 #include "iscsi_target_erl1.h"
  26 #include "iscsi_target_erl2.h"
  27 #include "iscsi_target_tpg.h"
  28 #include "iscsi_target_util.h"
  29 #include "iscsi_target.h"
  30
  31 extern struct list_head g_tiqn_list;
  32 extern spinlock_t tiqn_lock;
  33
  34 int iscsit_add_r2t_to_list(
  35         struct iscsit_cmd *cmd,
  36         u32 offset,
  37         u32 xfer_len,
  38         int recovery,
  39         u32 r2t_sn)
  40 {
  41         struct iscsi_r2t *r2t;
  42
  43         lockdep_assert_held(&cmd->r2t_lock);
  44
  45         WARN_ON_ONCE((s32)xfer_len < 0);
  46
  47         r2t = kmem_cache_zalloc(lio_r2t_cache, GFP_ATOMIC);
  48         if (!r2t) {
  49                 pr_err("Unable to allocate memory for struct iscsi_r2t.\n");
  50                 return -1;
  51         }
  52         INIT_LIST_HEAD(&r2t->r2t_list);
  53
  54         r2t->recovery_r2t = recovery;
  55         r2t->r2t_sn = (!r2t_sn) ? cmd->r2t_sn++ : r2t_sn;
  56         r2t->offset = offset;
  57         r2t->xfer_len = xfer_len;
  58         list_add_tail(&r2t->r2t_list, &cmd->cmd_r2t_list);
  59         spin_unlock_bh(&cmd->r2t_lock);
  60
  61         iscsit_add_cmd_to_immediate_queue(cmd, cmd->conn, ISTATE_SEND_R2T);
  62
  63         spin_lock_bh(&cmd->r2t_lock);
  64         return 0;
  65 }
  66
  67 struct iscsi_r2t *iscsit_get_r2t_for_eos(
  68         struct iscsit_cmd *cmd,
  69         u32 offset,
  70         u32 length)
  71 {
  72         struct iscsi_r2t *r2t;
  73
  74         spin_lock_bh(&cmd->r2t_lock);
  75         list_for_each_entry(r2t, &cmd->cmd_r2t_list, r2t_list) {
  76                 if ((r2t->offset <= offset) &&
  77                     (r2t->offset + r2t->xfer_len) >= (offset + length)) {
  78                         spin_unlock_bh(&cmd->r2t_lock);
  79                         return r2t;
  80                 }
  81         }
  82         spin_unlock_bh(&cmd->r2t_lock);
  83
  84         pr_err("Unable to locate R2T for Offset: %u, Length:"
  85                         " %u\n", offset, length);
  86         return NULL;
  87 }
  88
  89 struct iscsi_r2t *iscsit_get_r2t_from_list(struct iscsit_cmd *cmd)
  90 {
  91         struct iscsi_r2t *r2t;
  92
  93         spin_lock_bh(&cmd->r2t_lock);
  94         list_for_each_entry(r2t, &cmd->cmd_r2t_list, r2t_list) {
  95                 if (!r2t->sent_r2t) {
  96                         spin_unlock_bh(&cmd->r2t_lock);
  97                         return r2t;
  98                 }
  99         }
 100         spin_unlock_bh(&cmd->r2t_lock);
 101
 102         pr_err("Unable to locate next R2T to send for ITT:"
 103                         " 0x%08x.\n", cmd->init_task_tag);
 104         return NULL;
 105 }
 106
 107 void iscsit_free_r2t(struct iscsi_r2t *r2t, struct iscsit_cmd *cmd)
 108 {
 109         lockdep_assert_held(&cmd->r2t_lock);
 110
 111         list_del(&r2t->r2t_list);
 112         kmem_cache_free(lio_r2t_cache, r2t);
 113 }
 114
 115 void iscsit_free_r2ts_from_list(struct iscsit_cmd *cmd)
 116 {
 117         struct iscsi_r2t *r2t, *r2t_tmp;
 118
 119         spin_lock_bh(&cmd->r2t_lock);
 120         list_for_each_entry_safe(r2t, r2t_tmp, &cmd->cmd_r2t_list, r2t_list)
 121                 iscsit_free_r2t(r2t, cmd);
 122         spin_unlock_bh(&cmd->r2t_lock);
 123 }
 124
 125 static int iscsit_wait_for_tag(struct se_session *se_sess, int state, int *cpup)
 126 {
 127         int tag = -1;
 128         DEFINE_SBQ_WAIT(wait);
 129         struct sbq_wait_state *ws;
 130         struct sbitmap_queue *sbq;
 131
 132         if (state == TASK_RUNNING)
 133                 return tag;
 134
 135         sbq = &se_sess->sess_tag_pool;
 136         ws = &sbq->ws[0];
 137         for (;;) {
 138                 sbitmap_prepare_to_wait(sbq, ws, &wait, state);
 139                 if (signal_pending_state(state, current))
 140                         break;
 141                 tag = sbitmap_queue_get(sbq, cpup);
 142                 if (tag >= 0)
 143                         break;
 144                 schedule();
 145         }
 146
 147         sbitmap_finish_wait(sbq, ws, &wait);
 148         return tag;
 149 }
 150
 151 /*
 152  * May be called from software interrupt (timer) context for allocating
 153  * iSCSI NopINs.
 154  */
 155 struct iscsit_cmd *iscsit_allocate_cmd(struct iscsit_conn *conn, int state)
 156 {
 157         struct iscsit_cmd *cmd;
 158         struct se_session *se_sess = conn->sess->se_sess;
 159         int size, tag, cpu;
 160
 161         tag = sbitmap_queue_get(&se_sess->sess_tag_pool, &cpu);
 162         if (tag < 0)
 163                 tag = iscsit_wait_for_tag(se_sess, state, &cpu);
 164         if (tag < 0)
 165                 return NULL;
 166
 167         size = sizeof(struct iscsit_cmd) + conn->conn_transport->priv_size;
 168         cmd = (struct iscsit_cmd *)(se_sess->sess_cmd_map + (tag * size));
 169         memset(cmd, 0, size);
 170
 171         cmd->se_cmd.map_tag = tag;
 172         cmd->se_cmd.map_cpu = cpu;
 173         cmd->conn = conn;
 174         cmd->data_direction = DMA_NONE;
 175         INIT_LIST_HEAD(&cmd->i_conn_node);
 176         INIT_LIST_HEAD(&cmd->datain_list);
 177         INIT_LIST_HEAD(&cmd->cmd_r2t_list);
 178         spin_lock_init(&cmd->datain_lock);
 179         spin_lock_init(&cmd->dataout_timeout_lock);
 180         spin_lock_init(&cmd->istate_lock);
 181         spin_lock_init(&cmd->error_lock);
 182         spin_lock_init(&cmd->r2t_lock);
 183         timer_setup(&cmd->dataout_timer, iscsit_handle_dataout_timeout, 0);
 184
 185         return cmd;
 186 }
 187 EXPORT_SYMBOL(iscsit_allocate_cmd);
 188
 189 struct iscsi_seq *iscsit_get_seq_holder_for_datain(
 190         struct iscsit_cmd *cmd,
 191         u32 seq_send_order)
 192 {
 193         u32 i;
 194
 195         for (i = 0; i < cmd->seq_count; i++)
 196                 if (cmd->seq_list[i].seq_send_order == seq_send_order)
 197                         return &cmd->seq_list[i];
 198
 199         return NULL;
 200 }
 201
 202 struct iscsi_seq *iscsit_get_seq_holder_for_r2t(struct iscsit_cmd *cmd)
 203 {
 204         u32 i;
 205
 206         if (!cmd->seq_list) {
 207                 pr_err("struct iscsit_cmd->seq_list is NULL!\n");
 208                 return NULL;
 209         }
 210
 211         for (i = 0; i < cmd->seq_count; i++) {
 212                 if (cmd->seq_list[i].type != SEQTYPE_NORMAL)
 213                         continue;
 214                 if (cmd->seq_list[i].seq_send_order == cmd->seq_send_order) {
 215                         cmd->seq_send_order++;
 216                         return &cmd->seq_list[i];
 217                 }
 218         }
 219
 220         return NULL;
 221 }
 222
 223 struct iscsi_r2t *iscsit_get_holder_for_r2tsn(
 224         struct iscsit_cmd *cmd,
 225         u32 r2t_sn)
 226 {
 227         struct iscsi_r2t *r2t;
 228
 229         spin_lock_bh(&cmd->r2t_lock);
 230         list_for_each_entry(r2t, &cmd->cmd_r2t_list, r2t_list) {
 231                 if (r2t->r2t_sn == r2t_sn) {
 232                         spin_unlock_bh(&cmd->r2t_lock);
 233                         return r2t;
 234                 }
 235         }
 236         spin_unlock_bh(&cmd->r2t_lock);
 237
 238         return NULL;
 239 }
 240
 241 static inline int iscsit_check_received_cmdsn(struct iscsit_session *sess, u32 cmdsn)
 242 {
 243         u32 max_cmdsn;
 244         int ret;
 245
 246         /*
 247          * This is the proper method of checking received CmdSN against
 248          * ExpCmdSN and MaxCmdSN values, as well as accounting for out
 249          * or order CmdSNs due to multiple connection sessions and/or
 250          * CRC failures.
 251          */
 252         max_cmdsn = atomic_read(&sess->max_cmd_sn);
 253         if (iscsi_sna_gt(cmdsn, max_cmdsn)) {
 254                 pr_err("Received CmdSN: 0x%08x is greater than"
 255                        " MaxCmdSN: 0x%08x, ignoring.\n", cmdsn, max_cmdsn);
 256                 ret = CMDSN_MAXCMDSN_OVERRUN;
 257
 258         } else if (cmdsn == sess->exp_cmd_sn) {
 259                 sess->exp_cmd_sn++;
 260                 pr_debug("Received CmdSN matches ExpCmdSN,"
 261                       " incremented ExpCmdSN to: 0x%08x\n",
 262                       sess->exp_cmd_sn);
 263                 ret = CMDSN_NORMAL_OPERATION;
 264
 265         } else if (iscsi_sna_gt(cmdsn, sess->exp_cmd_sn)) {
 266                 pr_debug("Received CmdSN: 0x%08x is greater"
 267                       " than ExpCmdSN: 0x%08x, not acknowledging.\n",
 268                       cmdsn, sess->exp_cmd_sn);
 269                 ret = CMDSN_HIGHER_THAN_EXP;
 270
 271         } else {
 272                 pr_err("Received CmdSN: 0x%08x is less than"
 273                        " ExpCmdSN: 0x%08x, ignoring.\n", cmdsn,
 274                        sess->exp_cmd_sn);
 275                 ret = CMDSN_LOWER_THAN_EXP;
 276         }
 277
 278         return ret;
 279 }
 280
 281 /*
 282  * Commands may be received out of order if MC/S is in use.
 283  * Ensure they are executed in CmdSN order.
 284  */
 285 int iscsit_sequence_cmd(struct iscsit_conn *conn, struct iscsit_cmd *cmd,
 286                         unsigned char *buf, __be32 cmdsn)
 287 {
 288         int ret, cmdsn_ret;
 289         bool reject = false;
 290         u8 reason = ISCSI_REASON_BOOKMARK_NO_RESOURCES;
 291
 292         mutex_lock(&conn->sess->cmdsn_mutex);
 293
 294         cmdsn_ret = iscsit_check_received_cmdsn(conn->sess, be32_to_cpu(cmdsn));
 295         switch (cmdsn_ret) {
 296         case CMDSN_NORMAL_OPERATION:
 297                 ret = iscsit_execute_cmd(cmd, 0);
 298                 if ((ret >= 0) && !list_empty(&conn->sess->sess_ooo_cmdsn_list))
 299                         iscsit_execute_ooo_cmdsns(conn->sess);
 300                 else if (ret < 0) {
 301                         reject = true;
 302                         ret = CMDSN_ERROR_CANNOT_RECOVER;
 303                 }
 304                 break;
 305         case CMDSN_HIGHER_THAN_EXP:
 306                 ret = iscsit_handle_ooo_cmdsn(conn->sess, cmd, be32_to_cpu(cmdsn));
 307                 if (ret < 0) {
 308                         reject = true;
 309                         ret = CMDSN_ERROR_CANNOT_RECOVER;
 310                         break;
 311                 }
 312                 ret = CMDSN_HIGHER_THAN_EXP;
 313                 break;
 314         case CMDSN_LOWER_THAN_EXP:
 315         case CMDSN_MAXCMDSN_OVERRUN:
 316         default:
 317                 cmd->i_state = ISTATE_REMOVE;
 318                 iscsit_add_cmd_to_immediate_queue(cmd, conn, cmd->i_state);
 319                 /*
 320                  * Existing callers for iscsit_sequence_cmd() will silently
 321                  * ignore commands with CMDSN_LOWER_THAN_EXP, so force this
 322                  * return for CMDSN_MAXCMDSN_OVERRUN as well..
 323                  */
 324                 ret = CMDSN_LOWER_THAN_EXP;
 325                 break;
 326         }
 327         mutex_unlock(&conn->sess->cmdsn_mutex);
 328
 329         if (reject)
 330                 iscsit_reject_cmd(cmd, reason, buf);
 331
 332         return ret;
 333 }
 334 EXPORT_SYMBOL(iscsit_sequence_cmd);
 335
 336 int iscsit_check_unsolicited_dataout(struct iscsit_cmd *cmd, unsigned char *buf)
 337 {
 338         struct iscsit_conn *conn = cmd->conn;
 339         struct se_cmd *se_cmd = &cmd->se_cmd;
 340         struct iscsi_data *hdr = (struct iscsi_data *) buf;
 341         u32 payload_length = ntoh24(hdr->dlength);
 342
 343         if (conn->sess->sess_ops->InitialR2T) {
 344                 pr_err("Received unexpected unsolicited data"
 345                         " while InitialR2T=Yes, protocol error.\n");
 346                 transport_send_check_condition_and_sense(se_cmd,
 347                                 TCM_UNEXPECTED_UNSOLICITED_DATA, 0);
 348                 return -1;
 349         }
 350
 351         if ((cmd->first_burst_len + payload_length) >
 352              conn->sess->sess_ops->FirstBurstLength) {
 353                 pr_err("Total %u bytes exceeds FirstBurstLength: %u"
 354                         " for this Unsolicited DataOut Burst.\n",
 355                         (cmd->first_burst_len + payload_length),
 356                                 conn->sess->sess_ops->FirstBurstLength);
 357                 transport_send_check_condition_and_sense(se_cmd,
 358                                 TCM_INCORRECT_AMOUNT_OF_DATA, 0);
 359                 return -1;
 360         }
 361
 362         if (!(hdr->flags & ISCSI_FLAG_CMD_FINAL))
 363                 return 0;
 364
 365         if (((cmd->first_burst_len + payload_length) != cmd->se_cmd.data_length) &&
 366             ((cmd->first_burst_len + payload_length) !=
 367               conn->sess->sess_ops->FirstBurstLength)) {
 368                 pr_err("Unsolicited non-immediate data received %u"
 369                         " does not equal FirstBurstLength: %u, and does"
 370                         " not equal ExpXferLen %u.\n",
 371                         (cmd->first_burst_len + payload_length),
 372                         conn->sess->sess_ops->FirstBurstLength, cmd->se_cmd.data_length);
 373                 transport_send_check_condition_and_sense(se_cmd,
 374                                 TCM_INCORRECT_AMOUNT_OF_DATA, 0);
 375                 return -1;
 376         }
 377         return 0;
 378 }
 379
 380 struct iscsit_cmd *iscsit_find_cmd_from_itt(
 381         struct iscsit_conn *conn,
 382         itt_t init_task_tag)
 383 {
 384         struct iscsit_cmd *cmd;
 385
 386         spin_lock_bh(&conn->cmd_lock);
 387         list_for_each_entry(cmd, &conn->conn_cmd_list, i_conn_node) {
 388                 if (cmd->init_task_tag == init_task_tag) {
 389                         spin_unlock_bh(&conn->cmd_lock);
 390                         return cmd;
 391                 }
 392         }
 393         spin_unlock_bh(&conn->cmd_lock);
 394
 395         pr_err("Unable to locate ITT: 0x%08x on CID: %hu",
 396                         init_task_tag, conn->cid);
 397         return NULL;
 398 }
 399 EXPORT_SYMBOL(iscsit_find_cmd_from_itt);
 400
 401 struct iscsit_cmd *iscsit_find_cmd_from_itt_or_dump(
 402         struct iscsit_conn *conn,
 403         itt_t init_task_tag,
 404         u32 length)
 405 {
 406         struct iscsit_cmd *cmd;
 407
 408         spin_lock_bh(&conn->cmd_lock);
 409         list_for_each_entry(cmd, &conn->conn_cmd_list, i_conn_node) {
 410                 if (cmd->cmd_flags & ICF_GOT_LAST_DATAOUT)
 411                         continue;
 412                 if (cmd->init_task_tag == init_task_tag) {
 413                         spin_unlock_bh(&conn->cmd_lock);
 414                         return cmd;
 415                 }
 416         }
 417         spin_unlock_bh(&conn->cmd_lock);
 418
 419         pr_err("Unable to locate ITT: 0x%08x on CID: %hu,"
 420                         " dumping payload\n", init_task_tag, conn->cid);
 421         if (length)
 422                 iscsit_dump_data_payload(conn, length, 1);
 423
 424         return NULL;
 425 }
 426 EXPORT_SYMBOL(iscsit_find_cmd_from_itt_or_dump);
 427
 428 struct iscsit_cmd *iscsit_find_cmd_from_ttt(
 429         struct iscsit_conn *conn,
 430         u32 targ_xfer_tag)
 431 {
 432         struct iscsit_cmd *cmd = NULL;
 433
 434         spin_lock_bh(&conn->cmd_lock);
 435         list_for_each_entry(cmd, &conn->conn_cmd_list, i_conn_node) {
 436                 if (cmd->targ_xfer_tag == targ_xfer_tag) {
 437                         spin_unlock_bh(&conn->cmd_lock);
 438                         return cmd;
 439                 }
 440         }
 441         spin_unlock_bh(&conn->cmd_lock);
 442
 443         pr_err("Unable to locate TTT: 0x%08x on CID: %hu\n",
 444                         targ_xfer_tag, conn->cid);
 445         return NULL;
 446 }
 447
 448 int iscsit_find_cmd_for_recovery(
 449         struct iscsit_session *sess,
 450         struct iscsit_cmd **cmd_ptr,
 451         struct iscsi_conn_recovery **cr_ptr,
 452         itt_t init_task_tag)
 453 {
 454         struct iscsit_cmd *cmd = NULL;
 455         struct iscsi_conn_recovery *cr;
 456         /*
 457          * Scan through the inactive connection recovery list's command list.
 458          * If init_task_tag matches the command is still alligent.
 459          */
 460         spin_lock(&sess->cr_i_lock);
 461         list_for_each_entry(cr, &sess->cr_inactive_list, cr_list) {
 462                 spin_lock(&cr->conn_recovery_cmd_lock);
 463                 list_for_each_entry(cmd, &cr->conn_recovery_cmd_list, i_conn_node) {
 464                         if (cmd->init_task_tag == init_task_tag) {
 465                                 spin_unlock(&cr->conn_recovery_cmd_lock);
 466                                 spin_unlock(&sess->cr_i_lock);
 467
 468                                 *cr_ptr = cr;
 469                                 *cmd_ptr = cmd;
 470                                 return -2;
 471                         }
 472                 }
 473                 spin_unlock(&cr->conn_recovery_cmd_lock);
 474         }
 475         spin_unlock(&sess->cr_i_lock);
 476         /*
 477          * Scan through the active connection recovery list's command list.
 478          * If init_task_tag matches the command is ready to be reassigned.
 479          */
 480         spin_lock(&sess->cr_a_lock);
 481         list_for_each_entry(cr, &sess->cr_active_list, cr_list) {
 482                 spin_lock(&cr->conn_recovery_cmd_lock);
 483                 list_for_each_entry(cmd, &cr->conn_recovery_cmd_list, i_conn_node) {
 484                         if (cmd->init_task_tag == init_task_tag) {
 485                                 spin_unlock(&cr->conn_recovery_cmd_lock);
 486                                 spin_unlock(&sess->cr_a_lock);
 487
 488                                 *cr_ptr = cr;
 489                                 *cmd_ptr = cmd;
 490                                 return 0;
 491                         }
 492                 }
 493                 spin_unlock(&cr->conn_recovery_cmd_lock);
 494         }
 495         spin_unlock(&sess->cr_a_lock);
 496
 497         return -1;
 498 }
 499
 500 void iscsit_add_cmd_to_immediate_queue(
 501         struct iscsit_cmd *cmd,
 502         struct iscsit_conn *conn,
 503         u8 state)
 504 {
 505         struct iscsi_queue_req *qr;
 506
 507         qr = kmem_cache_zalloc(lio_qr_cache, GFP_ATOMIC);
 508         if (!qr) {
 509                 pr_err("Unable to allocate memory for"
 510                                 " struct iscsi_queue_req\n");
 511                 return;
 512         }
 513         INIT_LIST_HEAD(&qr->qr_list);
 514         qr->cmd = cmd;
 515         qr->state = state;
 516
 517         spin_lock_bh(&conn->immed_queue_lock);
 518         list_add_tail(&qr->qr_list, &conn->immed_queue_list);
 519         atomic_inc(&cmd->immed_queue_count);
 520         atomic_set(&conn->check_immediate_queue, 1);
 521         spin_unlock_bh(&conn->immed_queue_lock);
 522
 523         wake_up(&conn->queues_wq);
 524 }
 525 EXPORT_SYMBOL(iscsit_add_cmd_to_immediate_queue);
 526
 527 struct iscsi_queue_req *iscsit_get_cmd_from_immediate_queue(struct iscsit_conn *conn)
 528 {
 529         struct iscsi_queue_req *qr;
 530
 531         spin_lock_bh(&conn->immed_queue_lock);
 532         if (list_empty(&conn->immed_queue_list)) {
 533                 spin_unlock_bh(&conn->immed_queue_lock);
 534                 return NULL;
 535         }
 536         qr = list_first_entry(&conn->immed_queue_list,
 537                               struct iscsi_queue_req, qr_list);
 538
 539         list_del(&qr->qr_list);
 540         if (qr->cmd)
 541                 atomic_dec(&qr->cmd->immed_queue_count);
 542         spin_unlock_bh(&conn->immed_queue_lock);
 543
 544         return qr;
 545 }
 546
 547 static void iscsit_remove_cmd_from_immediate_queue(
 548         struct iscsit_cmd *cmd,
 549         struct iscsit_conn *conn)
 550 {
 551         struct iscsi_queue_req *qr, *qr_tmp;
 552
 553         spin_lock_bh(&conn->immed_queue_lock);
 554         if (!atomic_read(&cmd->immed_queue_count)) {
 555                 spin_unlock_bh(&conn->immed_queue_lock);
 556                 return;
 557         }
 558
 559         list_for_each_entry_safe(qr, qr_tmp, &conn->immed_queue_list, qr_list) {
 560                 if (qr->cmd != cmd)
 561                         continue;
 562
 563                 atomic_dec(&qr->cmd->immed_queue_count);
 564                 list_del(&qr->qr_list);
 565                 kmem_cache_free(lio_qr_cache, qr);
 566         }
 567         spin_unlock_bh(&conn->immed_queue_lock);
 568
 569         if (atomic_read(&cmd->immed_queue_count)) {
 570                 pr_err("ITT: 0x%08x immed_queue_count: %d\n",
 571                         cmd->init_task_tag,
 572                         atomic_read(&cmd->immed_queue_count));
 573         }
 574 }
 575
 576 int iscsit_add_cmd_to_response_queue(
 577         struct iscsit_cmd *cmd,
 578         struct iscsit_conn *conn,
 579         u8 state)
 580 {
 581         struct iscsi_queue_req *qr;
 582
 583         qr = kmem_cache_zalloc(lio_qr_cache, GFP_ATOMIC);
 584         if (!qr) {
 585                 pr_err("Unable to allocate memory for"
 586                         " struct iscsi_queue_req\n");
 587                 return -ENOMEM;
 588         }
 589         INIT_LIST_HEAD(&qr->qr_list);
 590         qr->cmd = cmd;
 591         qr->state = state;
 592
 593         spin_lock_bh(&conn->response_queue_lock);
 594         list_add_tail(&qr->qr_list, &conn->response_queue_list);
 595         atomic_inc(&cmd->response_queue_count);
 596         spin_unlock_bh(&conn->response_queue_lock);
 597
 598         wake_up(&conn->queues_wq);
 599         return 0;
 600 }
 601
 602 struct iscsi_queue_req *iscsit_get_cmd_from_response_queue(struct iscsit_conn *conn)
 603 {
 604         struct iscsi_queue_req *qr;
 605
 606         spin_lock_bh(&conn->response_queue_lock);
 607         if (list_empty(&conn->response_queue_list)) {
 608                 spin_unlock_bh(&conn->response_queue_lock);
 609                 return NULL;
 610         }
 611
 612         qr = list_first_entry(&conn->response_queue_list,
 613                               struct iscsi_queue_req, qr_list);
 614
 615         list_del(&qr->qr_list);
 616         if (qr->cmd)
 617                 atomic_dec(&qr->cmd->response_queue_count);
 618         spin_unlock_bh(&conn->response_queue_lock);
 619
 620         return qr;
 621 }
 622
 623 static void iscsit_remove_cmd_from_response_queue(
 624         struct iscsit_cmd *cmd,
 625         struct iscsit_conn *conn)
 626 {
 627         struct iscsi_queue_req *qr, *qr_tmp;
 628
 629         spin_lock_bh(&conn->response_queue_lock);
 630         if (!atomic_read(&cmd->response_queue_count)) {
 631                 spin_unlock_bh(&conn->response_queue_lock);
 632                 return;
 633         }
 634
 635         list_for_each_entry_safe(qr, qr_tmp, &conn->response_queue_list,
 636                                 qr_list) {
 637                 if (qr->cmd != cmd)
 638                         continue;
 639
 640                 atomic_dec(&qr->cmd->response_queue_count);
 641                 list_del(&qr->qr_list);
 642                 kmem_cache_free(lio_qr_cache, qr);
 643         }
 644         spin_unlock_bh(&conn->response_queue_lock);
 645
 646         if (atomic_read(&cmd->response_queue_count)) {
 647                 pr_err("ITT: 0x%08x response_queue_count: %d\n",
 648                         cmd->init_task_tag,
 649                         atomic_read(&cmd->response_queue_count));
 650         }
 651 }
 652
 653 bool iscsit_conn_all_queues_empty(struct iscsit_conn *conn)
 654 {
 655         bool empty;
 656
 657         spin_lock_bh(&conn->immed_queue_lock);
 658         empty = list_empty(&conn->immed_queue_list);
 659         spin_unlock_bh(&conn->immed_queue_lock);
 660
 661         if (!empty)
 662                 return empty;
 663
 664         spin_lock_bh(&conn->response_queue_lock);
 665         empty = list_empty(&conn->response_queue_list);
 666         spin_unlock_bh(&conn->response_queue_lock);
 667
 668         return empty;
 669 }
 670
 671 void iscsit_free_queue_reqs_for_conn(struct iscsit_conn *conn)
 672 {
 673         struct iscsi_queue_req *qr, *qr_tmp;
 674
 675         spin_lock_bh(&conn->immed_queue_lock);
 676         list_for_each_entry_safe(qr, qr_tmp, &conn->immed_queue_list, qr_list) {
 677                 list_del(&qr->qr_list);
 678                 if (qr->cmd)
 679                         atomic_dec(&qr->cmd->immed_queue_count);
 680
 681                 kmem_cache_free(lio_qr_cache, qr);
 682         }
 683         spin_unlock_bh(&conn->immed_queue_lock);
 684
 685         spin_lock_bh(&conn->response_queue_lock);
 686         list_for_each_entry_safe(qr, qr_tmp, &conn->response_queue_list,
 687                         qr_list) {
 688                 list_del(&qr->qr_list);
 689                 if (qr->cmd)
 690                         atomic_dec(&qr->cmd->response_queue_count);
 691
 692                 kmem_cache_free(lio_qr_cache, qr);
 693         }
 694         spin_unlock_bh(&conn->response_queue_lock);
 695 }
 696
 697 void iscsit_release_cmd(struct iscsit_cmd *cmd)
 698 {
 699         struct iscsit_session *sess;
 700         struct se_cmd *se_cmd = &cmd->se_cmd;
 701
 702         WARN_ON(!list_empty(&cmd->i_conn_node));
 703
 704         if (cmd->conn)
 705                 sess = cmd->conn->sess;
 706         else
 707                 sess = cmd->sess;
 708
 709         BUG_ON(!sess || !sess->se_sess);
 710
 711         kfree(cmd->buf_ptr);
 712         kfree(cmd->pdu_list);
 713         kfree(cmd->seq_list);
 714         kfree(cmd->tmr_req);
 715         kfree(cmd->overflow_buf);
 716         kfree(cmd->iov_data);
 717         kfree(cmd->text_in_ptr);
 718
 719         target_free_tag(sess->se_sess, se_cmd);
 720 }
 721 EXPORT_SYMBOL(iscsit_release_cmd);
 722
 723 void __iscsit_free_cmd(struct iscsit_cmd *cmd, bool check_queues)
 724 {
 725         struct iscsit_conn *conn = cmd->conn;
 726
 727         WARN_ON(!list_empty(&cmd->i_conn_node));
 728
 729         if (cmd->data_direction == DMA_TO_DEVICE) {
 730                 iscsit_stop_dataout_timer(cmd);
 731                 iscsit_free_r2ts_from_list(cmd);
 732         }
 733         if (cmd->data_direction == DMA_FROM_DEVICE)
 734                 iscsit_free_all_datain_reqs(cmd);
 735
 736         if (conn && check_queues) {
 737                 iscsit_remove_cmd_from_immediate_queue(cmd, conn);
 738                 iscsit_remove_cmd_from_response_queue(cmd, conn);
 739         }
 740
 741         if (conn && conn->conn_transport->iscsit_unmap_cmd)
 742                 conn->conn_transport->iscsit_unmap_cmd(conn, cmd);
 743 }
 744
 745 void iscsit_free_cmd(struct iscsit_cmd *cmd, bool shutdown)
 746 {
 747         struct se_cmd *se_cmd = cmd->se_cmd.se_tfo ? &cmd->se_cmd : NULL;
 748         int rc;
 749
 750         WARN_ON(!list_empty(&cmd->i_conn_node));
 751
 752         __iscsit_free_cmd(cmd, shutdown);
 753         if (se_cmd) {
 754                 rc = transport_generic_free_cmd(se_cmd, shutdown);
 755                 if (!rc && shutdown && se_cmd->se_sess) {
 756                         __iscsit_free_cmd(cmd, shutdown);
 757                         target_put_sess_cmd(se_cmd);
 758                 }
 759         } else {
 760                 iscsit_release_cmd(cmd);
 761         }
 762 }
 763 EXPORT_SYMBOL(iscsit_free_cmd);
 764
 765 bool iscsit_check_session_usage_count(struct iscsit_session *sess,
 766                                       bool can_sleep)
 767 {
 768         spin_lock_bh(&sess->session_usage_lock);
 769         if (sess->session_usage_count != 0) {
 770                 sess->session_waiting_on_uc = 1;
 771                 spin_unlock_bh(&sess->session_usage_lock);
 772                 if (!can_sleep)
 773                         return true;
 774
 775                 wait_for_completion(&sess->session_waiting_on_uc_comp);
 776                 return false;
 777         }
 778         spin_unlock_bh(&sess->session_usage_lock);
 779
 780         return false;
 781 }
 782
 783 void iscsit_dec_session_usage_count(struct iscsit_session *sess)
 784 {
 785         spin_lock_bh(&sess->session_usage_lock);
 786         sess->session_usage_count--;
 787
 788         if (!sess->session_usage_count && sess->session_waiting_on_uc)
 789                 complete(&sess->session_waiting_on_uc_comp);
 790
 791         spin_unlock_bh(&sess->session_usage_lock);
 792 }
 793
 794 void iscsit_inc_session_usage_count(struct iscsit_session *sess)
 795 {
 796         spin_lock_bh(&sess->session_usage_lock);
 797         sess->session_usage_count++;
 798         spin_unlock_bh(&sess->session_usage_lock);
 799 }
 800
 801 struct iscsit_conn *iscsit_get_conn_from_cid(struct iscsit_session *sess, u16 cid)
 802 {
 803         struct iscsit_conn *conn;
 804
 805         spin_lock_bh(&sess->conn_lock);
 806         list_for_each_entry(conn, &sess->sess_conn_list, conn_list) {
 807                 if ((conn->cid == cid) &&
 808                     (conn->conn_state == TARG_CONN_STATE_LOGGED_IN)) {
 809                         iscsit_inc_conn_usage_count(conn);
 810                         spin_unlock_bh(&sess->conn_lock);
 811                         return conn;
 812                 }
 813         }
 814         spin_unlock_bh(&sess->conn_lock);
 815
 816         return NULL;
 817 }
 818
 819 struct iscsit_conn *iscsit_get_conn_from_cid_rcfr(struct iscsit_session *sess, u16 cid)
 820 {
 821         struct iscsit_conn *conn;
 822
 823         spin_lock_bh(&sess->conn_lock);
 824         list_for_each_entry(conn, &sess->sess_conn_list, conn_list) {
 825                 if (conn->cid == cid) {
 826                         iscsit_inc_conn_usage_count(conn);
 827                         spin_lock(&conn->state_lock);
 828                         atomic_set(&conn->connection_wait_rcfr, 1);
 829                         spin_unlock(&conn->state_lock);
 830                         spin_unlock_bh(&sess->conn_lock);
 831                         return conn;
 832                 }
 833         }
 834         spin_unlock_bh(&sess->conn_lock);
 835
 836         return NULL;
 837 }
 838
 839 void iscsit_check_conn_usage_count(struct iscsit_conn *conn)
 840 {
 841         spin_lock_bh(&conn->conn_usage_lock);
 842         if (conn->conn_usage_count != 0) {
 843                 conn->conn_waiting_on_uc = 1;
 844                 spin_unlock_bh(&conn->conn_usage_lock);
 845
 846                 wait_for_completion(&conn->conn_waiting_on_uc_comp);
 847                 return;
 848         }
 849         spin_unlock_bh(&conn->conn_usage_lock);
 850 }
 851
 852 void iscsit_dec_conn_usage_count(struct iscsit_conn *conn)
 853 {
 854         spin_lock_bh(&conn->conn_usage_lock);
 855         conn->conn_usage_count--;
 856
 857         if (!conn->conn_usage_count && conn->conn_waiting_on_uc)
 858                 complete(&conn->conn_waiting_on_uc_comp);
 859
 860         spin_unlock_bh(&conn->conn_usage_lock);
 861 }
 862
 863 void iscsit_inc_conn_usage_count(struct iscsit_conn *conn)
 864 {
 865         spin_lock_bh(&conn->conn_usage_lock);
 866         conn->conn_usage_count++;
 867         spin_unlock_bh(&conn->conn_usage_lock);
 868 }
 869
 870 static int iscsit_add_nopin(struct iscsit_conn *conn, int want_response)
 871 {
 872         u8 state;
 873         struct iscsit_cmd *cmd;
 874
 875         cmd = iscsit_allocate_cmd(conn, TASK_RUNNING);
 876         if (!cmd)
 877                 return -1;
 878
 879         cmd->iscsi_opcode = ISCSI_OP_NOOP_IN;
 880         state = (want_response) ? ISTATE_SEND_NOPIN_WANT_RESPONSE :
 881                                 ISTATE_SEND_NOPIN_NO_RESPONSE;
 882         cmd->init_task_tag = RESERVED_ITT;
 883         cmd->targ_xfer_tag = (want_response) ?
 884                              session_get_next_ttt(conn->sess) : 0xFFFFFFFF;
 885         spin_lock_bh(&conn->cmd_lock);
 886         list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
 887         spin_unlock_bh(&conn->cmd_lock);
 888
 889         if (want_response)
 890                 iscsit_start_nopin_response_timer(conn);
 891         iscsit_add_cmd_to_immediate_queue(cmd, conn, state);
 892
 893         return 0;
 894 }
 895
 896 void iscsit_handle_nopin_response_timeout(struct timer_list *t)
 897 {
 898         struct iscsit_conn *conn = from_timer(conn, t, nopin_response_timer);
 899         struct iscsit_session *sess = conn->sess;
 900
 901         iscsit_inc_conn_usage_count(conn);
 902
 903         spin_lock_bh(&conn->nopin_timer_lock);
 904         if (conn->nopin_response_timer_flags & ISCSI_TF_STOP) {
 905                 spin_unlock_bh(&conn->nopin_timer_lock);
 906                 iscsit_dec_conn_usage_count(conn);
 907                 return;
 908         }
 909
 910         pr_err("Did not receive response to NOPIN on CID: %hu, failing"
 911                 " connection for I_T Nexus %s,i,0x%6phN,%s,t,0x%02x\n",
 912                 conn->cid, sess->sess_ops->InitiatorName, sess->isid,
 913                 sess->tpg->tpg_tiqn->tiqn, (u32)sess->tpg->tpgt);
 914         conn->nopin_response_timer_flags &= ~ISCSI_TF_RUNNING;
 915         spin_unlock_bh(&conn->nopin_timer_lock);
 916
 917         iscsit_fill_cxn_timeout_err_stats(sess);
 918         iscsit_cause_connection_reinstatement(conn, 0);
 919         iscsit_dec_conn_usage_count(conn);
 920 }
 921
 922 void iscsit_mod_nopin_response_timer(struct iscsit_conn *conn)
 923 {
 924         struct iscsit_session *sess = conn->sess;
 925         struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
 926
 927         spin_lock_bh(&conn->nopin_timer_lock);
 928         if (!(conn->nopin_response_timer_flags & ISCSI_TF_RUNNING)) {
 929                 spin_unlock_bh(&conn->nopin_timer_lock);
 930                 return;
 931         }
 932
 933         mod_timer(&conn->nopin_response_timer,
 934                 (get_jiffies_64() + na->nopin_response_timeout * HZ));
 935         spin_unlock_bh(&conn->nopin_timer_lock);
 936 }
 937
 938 void iscsit_start_nopin_response_timer(struct iscsit_conn *conn)
 939 {
 940         struct iscsit_session *sess = conn->sess;
 941         struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
 942
 943         spin_lock_bh(&conn->nopin_timer_lock);
 944         if (conn->nopin_response_timer_flags & ISCSI_TF_RUNNING) {
 945                 spin_unlock_bh(&conn->nopin_timer_lock);
 946                 return;
 947         }
 948
 949         conn->nopin_response_timer_flags &= ~ISCSI_TF_STOP;
 950         conn->nopin_response_timer_flags |= ISCSI_TF_RUNNING;
 951         mod_timer(&conn->nopin_response_timer,
 952                   jiffies + na->nopin_response_timeout * HZ);
 953
 954         pr_debug("Started NOPIN Response Timer on CID: %d to %u"
 955                 " seconds\n", conn->cid, na->nopin_response_timeout);
 956         spin_unlock_bh(&conn->nopin_timer_lock);
 957 }
 958
 959 void iscsit_stop_nopin_response_timer(struct iscsit_conn *conn)
 960 {
 961         spin_lock_bh(&conn->nopin_timer_lock);
 962         if (!(conn->nopin_response_timer_flags & ISCSI_TF_RUNNING)) {
 963                 spin_unlock_bh(&conn->nopin_timer_lock);
 964                 return;
 965         }
 966         conn->nopin_response_timer_flags |= ISCSI_TF_STOP;
 967         spin_unlock_bh(&conn->nopin_timer_lock);
 968
 969         del_timer_sync(&conn->nopin_response_timer);
 970
 971         spin_lock_bh(&conn->nopin_timer_lock);
 972         conn->nopin_response_timer_flags &= ~ISCSI_TF_RUNNING;
 973         spin_unlock_bh(&conn->nopin_timer_lock);
 974 }
 975
 976 void iscsit_handle_nopin_timeout(struct timer_list *t)
 977 {
 978         struct iscsit_conn *conn = from_timer(conn, t, nopin_timer);
 979
 980         iscsit_inc_conn_usage_count(conn);
 981
 982         spin_lock_bh(&conn->nopin_timer_lock);
 983         if (conn->nopin_timer_flags & ISCSI_TF_STOP) {
 984                 spin_unlock_bh(&conn->nopin_timer_lock);
 985                 iscsit_dec_conn_usage_count(conn);
 986                 return;
 987         }
 988         conn->nopin_timer_flags &= ~ISCSI_TF_RUNNING;
 989         spin_unlock_bh(&conn->nopin_timer_lock);
 990
 991         iscsit_add_nopin(conn, 1);
 992         iscsit_dec_conn_usage_count(conn);
 993 }
 994
 995 void __iscsit_start_nopin_timer(struct iscsit_conn *conn)
 996 {
 997         struct iscsit_session *sess = conn->sess;
 998         struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
 999
1000         lockdep_assert_held(&conn->nopin_timer_lock);
1001
1002         /*
1003         * NOPIN timeout is disabled.
1004          */
1005         if (!na->nopin_timeout)
1006                 return;
1007
1008         if (conn->nopin_timer_flags & ISCSI_TF_RUNNING)
1009                 return;
1010
1011         conn->nopin_timer_flags &= ~ISCSI_TF_STOP;
1012         conn->nopin_timer_flags |= ISCSI_TF_RUNNING;
1013         mod_timer(&conn->nopin_timer, jiffies + na->nopin_timeout * HZ);
1014
1015         pr_debug("Started NOPIN Timer on CID: %d at %u second"
1016                 " interval\n", conn->cid, na->nopin_timeout);
1017 }
1018
1019 void iscsit_start_nopin_timer(struct iscsit_conn *conn)
1020 {
1021         spin_lock_bh(&conn->nopin_timer_lock);
1022         __iscsit_start_nopin_timer(conn);
1023         spin_unlock_bh(&conn->nopin_timer_lock);
1024 }
1025
1026 void iscsit_stop_nopin_timer(struct iscsit_conn *conn)
1027 {
1028         spin_lock_bh(&conn->nopin_timer_lock);
1029         if (!(conn->nopin_timer_flags & ISCSI_TF_RUNNING)) {
1030                 spin_unlock_bh(&conn->nopin_timer_lock);
1031                 return;
1032         }
1033         conn->nopin_timer_flags |= ISCSI_TF_STOP;
1034         spin_unlock_bh(&conn->nopin_timer_lock);
1035
1036         del_timer_sync(&conn->nopin_timer);
1037
1038         spin_lock_bh(&conn->nopin_timer_lock);
1039         conn->nopin_timer_flags &= ~ISCSI_TF_RUNNING;
1040         spin_unlock_bh(&conn->nopin_timer_lock);
1041 }
1042
1043 void iscsit_login_timeout(struct timer_list *t)
1044 {
1045         struct iscsit_conn *conn = from_timer(conn, t, login_timer);
1046         struct iscsi_login *login = conn->login;
1047
1048         pr_debug("Entering iscsi_target_login_timeout >>>>>>>>>>>>>>>>>>>\n");
1049
1050         spin_lock_bh(&conn->login_timer_lock);
1051         login->login_failed = 1;
1052
1053         if (conn->login_kworker) {
1054                 pr_debug("Sending SIGINT to conn->login_kworker %s/%d\n",
1055                          conn->login_kworker->comm, conn->login_kworker->pid);
1056                 send_sig(SIGINT, conn->login_kworker, 1);
1057         } else {
1058                 schedule_delayed_work(&conn->login_work, 0);
1059         }
1060         spin_unlock_bh(&conn->login_timer_lock);
1061 }
1062
1063 void iscsit_start_login_timer(struct iscsit_conn *conn, struct task_struct *kthr)
1064 {
1065         pr_debug("Login timer started\n");
1066
1067         conn->login_kworker = kthr;
1068         mod_timer(&conn->login_timer, jiffies + TA_LOGIN_TIMEOUT * HZ);
1069 }
1070
1071 int iscsit_set_login_timer_kworker(struct iscsit_conn *conn, struct task_struct *kthr)
1072 {
1073         struct iscsi_login *login = conn->login;
1074         int ret = 0;
1075
1076         spin_lock_bh(&conn->login_timer_lock);
1077         if (login->login_failed) {
1078                 /* The timer has already expired */
1079                 ret = -1;
1080         } else {
1081                 conn->login_kworker = kthr;
1082         }
1083         spin_unlock_bh(&conn->login_timer_lock);
1084
1085         return ret;
1086 }
1087
1088 void iscsit_stop_login_timer(struct iscsit_conn *conn)
1089 {
1090         pr_debug("Login timer stopped\n");
1091         timer_delete_sync(&conn->login_timer);
1092 }
1093
1094 int iscsit_send_tx_data(
1095         struct iscsit_cmd *cmd,
1096         struct iscsit_conn *conn,
1097         int use_misc)
1098 {
1099         int tx_sent, tx_size;
1100         u32 iov_count;
1101         struct kvec *iov;
1102
1103 send_data:
1104         tx_size = cmd->tx_size;
1105
1106         if (!use_misc) {
1107                 iov = &cmd->iov_data[0];
1108                 iov_count = cmd->iov_data_count;
1109         } else {
1110                 iov = &cmd->iov_misc[0];
1111                 iov_count = cmd->iov_misc_count;
1112         }
1113
1114         tx_sent = tx_data(conn, &iov[0], iov_count, tx_size);
1115         if (tx_size != tx_sent) {
1116                 if (tx_sent == -EAGAIN) {
1117                         pr_err("tx_data() returned -EAGAIN\n");
1118                         goto send_data;
1119                 } else
1120                         return -1;
1121         }
1122         cmd->tx_size = 0;
1123
1124         return 0;
1125 }
1126
1127 int iscsit_fe_sendpage_sg(
1128         struct iscsit_cmd *cmd,
1129         struct iscsit_conn *conn)
1130 {
1131         struct scatterlist *sg = cmd->first_data_sg;
1132         struct kvec iov;
1133         u32 tx_hdr_size, data_len;
1134         u32 offset = cmd->first_data_sg_off;
1135         int tx_sent, iov_off;
1136
1137 send_hdr:
1138         tx_hdr_size = ISCSI_HDR_LEN;
1139         if (conn->conn_ops->HeaderDigest)
1140                 tx_hdr_size += ISCSI_CRC_LEN;
1141
1142         iov.iov_base = cmd->pdu;
1143         iov.iov_len = tx_hdr_size;
1144
1145         tx_sent = tx_data(conn, &iov, 1, tx_hdr_size);
1146         if (tx_hdr_size != tx_sent) {
1147                 if (tx_sent == -EAGAIN) {
1148                         pr_err("tx_data() returned -EAGAIN\n");
1149                         goto send_hdr;
1150                 }
1151                 return -1;
1152         }
1153
1154         data_len = cmd->tx_size - tx_hdr_size - cmd->padding;
1155         /*
1156          * Set iov_off used by padding and data digest tx_data() calls below
1157          * in order to determine proper offset into cmd->iov_data[]
1158          */
1159         if (conn->conn_ops->DataDigest) {
1160                 data_len -= ISCSI_CRC_LEN;
1161                 if (cmd->padding)
1162                         iov_off = (cmd->iov_data_count - 2);
1163                 else
1164                         iov_off = (cmd->iov_data_count - 1);
1165         } else {
1166                 iov_off = (cmd->iov_data_count - 1);
1167         }
1168         /*
1169          * Perform sendpage() for each page in the scatterlist
1170          */
1171         while (data_len) {
1172                 u32 space = (sg->length - offset);
1173                 u32 sub_len = min_t(u32, data_len, space);
1174 send_pg:
1175                 tx_sent = conn->sock->ops->sendpage(conn->sock,
1176                                         sg_page(sg), sg->offset + offset, sub_len, 0);
1177                 if (tx_sent != sub_len) {
1178                         if (tx_sent == -EAGAIN) {
1179                                 pr_err("tcp_sendpage() returned"
1180                                                 " -EAGAIN\n");
1181                                 goto send_pg;
1182                         }
1183
1184                         pr_err("tcp_sendpage() failure: %d\n",
1185                                         tx_sent);
1186                         return -1;
1187                 }
1188
1189                 data_len -= sub_len;
1190                 offset = 0;
1191                 sg = sg_next(sg);
1192         }
1193
1194 send_padding:
1195         if (cmd->padding) {
1196                 struct kvec *iov_p = &cmd->iov_data[iov_off++];
1197
1198                 tx_sent = tx_data(conn, iov_p, 1, cmd->padding);
1199                 if (cmd->padding != tx_sent) {
1200                         if (tx_sent == -EAGAIN) {
1201                                 pr_err("tx_data() returned -EAGAIN\n");
1202                                 goto send_padding;
1203                         }
1204                         return -1;
1205                 }
1206         }
1207
1208 send_datacrc:
1209         if (conn->conn_ops->DataDigest) {
1210                 struct kvec *iov_d = &cmd->iov_data[iov_off];
1211
1212                 tx_sent = tx_data(conn, iov_d, 1, ISCSI_CRC_LEN);
1213                 if (ISCSI_CRC_LEN != tx_sent) {
1214                         if (tx_sent == -EAGAIN) {
1215                                 pr_err("tx_data() returned -EAGAIN\n");
1216                                 goto send_datacrc;
1217                         }
1218                         return -1;
1219                 }
1220         }
1221
1222         return 0;
1223 }
1224
1225 /*
1226  *      This function is used for mainly sending a ISCSI_TARG_LOGIN_RSP PDU
1227  *      back to the Initiator when an expection condition occurs with the
1228  *      errors set in status_class and status_detail.
1229  *
1230  *      Parameters:     iSCSI Connection, Status Class, Status Detail.
1231  *      Returns:        0 on success, -1 on error.
1232  */
1233 int iscsit_tx_login_rsp(struct iscsit_conn *conn, u8 status_class, u8 status_detail)
1234 {
1235         struct iscsi_login_rsp *hdr;
1236         struct iscsi_login *login = conn->conn_login;
1237
1238         login->login_failed = 1;
1239         iscsit_collect_login_stats(conn, status_class, status_detail);
1240
1241         memset(&login->rsp[0], 0, ISCSI_HDR_LEN);
1242
1243         hdr     = (struct iscsi_login_rsp *)&login->rsp[0];
1244         hdr->opcode             = ISCSI_OP_LOGIN_RSP;
1245         hdr->status_class       = status_class;
1246         hdr->status_detail      = status_detail;
1247         hdr->itt                = conn->login_itt;
1248
1249         return conn->conn_transport->iscsit_put_login_tx(conn, login, 0);
1250 }
1251
1252 void iscsit_print_session_params(struct iscsit_session *sess)
1253 {
1254         struct iscsit_conn *conn;
1255
1256         pr_debug("-----------------------------[Session Params for"
1257                 " SID: %u]-----------------------------\n", sess->sid);
1258         spin_lock_bh(&sess->conn_lock);
1259         list_for_each_entry(conn, &sess->sess_conn_list, conn_list)
1260                 iscsi_dump_conn_ops(conn->conn_ops);
1261         spin_unlock_bh(&sess->conn_lock);
1262
1263         iscsi_dump_sess_ops(sess->sess_ops);
1264 }
1265
1266 int rx_data(
1267         struct iscsit_conn *conn,
1268         struct kvec *iov,
1269         int iov_count,
1270         int data)
1271 {
1272         int rx_loop = 0, total_rx = 0;
1273         struct msghdr msg;
1274
1275         if (!conn || !conn->sock || !conn->conn_ops)
1276                 return -1;
1277
1278         memset(&msg, 0, sizeof(struct msghdr));
1279         iov_iter_kvec(&msg.msg_iter, ITER_DEST, iov, iov_count, data);
1280
1281         while (msg_data_left(&msg)) {
1282                 rx_loop = sock_recvmsg(conn->sock, &msg, MSG_WAITALL);
1283                 if (rx_loop <= 0) {
1284                         pr_debug("rx_loop: %d total_rx: %d\n",
1285                                 rx_loop, total_rx);
1286                         return rx_loop;
1287                 }
1288                 total_rx += rx_loop;
1289                 pr_debug("rx_loop: %d, total_rx: %d, data: %d\n",
1290                                 rx_loop, total_rx, data);
1291         }
1292
1293         return total_rx;
1294 }
1295
1296 int tx_data(
1297         struct iscsit_conn *conn,
1298         struct kvec *iov,
1299         int iov_count,
1300         int data)
1301 {
1302         struct msghdr msg;
1303         int total_tx = 0;
1304
1305         if (!conn || !conn->sock || !conn->conn_ops)
1306                 return -1;
1307
1308         if (data <= 0) {
1309                 pr_err("Data length is: %d\n", data);
1310                 return -1;
1311         }
1312
1313         memset(&msg, 0, sizeof(struct msghdr));
1314
1315         iov_iter_kvec(&msg.msg_iter, ITER_SOURCE, iov, iov_count, data);
1316
1317         while (msg_data_left(&msg)) {
1318                 int tx_loop = sock_sendmsg(conn->sock, &msg);
1319                 if (tx_loop <= 0) {
1320                         pr_debug("tx_loop: %d total_tx %d\n",
1321                                 tx_loop, total_tx);
1322                         return tx_loop;
1323                 }
1324                 total_tx += tx_loop;
1325                 pr_debug("tx_loop: %d, total_tx: %d, data: %d\n",
1326                                         tx_loop, total_tx, data);
1327         }
1328
1329         return total_tx;
1330 }
1331
1332 void iscsit_collect_login_stats(
1333         struct iscsit_conn *conn,
1334         u8 status_class,
1335         u8 status_detail)
1336 {
1337         struct iscsi_param *intrname = NULL;
1338         struct iscsi_tiqn *tiqn;
1339         struct iscsi_login_stats *ls;
1340
1341         tiqn = iscsit_snmp_get_tiqn(conn);
1342         if (!tiqn)
1343                 return;
1344
1345         ls = &tiqn->login_stats;
1346
1347         spin_lock(&ls->lock);
1348         if (status_class == ISCSI_STATUS_CLS_SUCCESS)
1349                 ls->accepts++;
1350         else if (status_class == ISCSI_STATUS_CLS_REDIRECT) {
1351                 ls->redirects++;
1352                 ls->last_fail_type = ISCSI_LOGIN_FAIL_REDIRECT;
1353         } else if ((status_class == ISCSI_STATUS_CLS_INITIATOR_ERR)  &&
1354                  (status_detail == ISCSI_LOGIN_STATUS_AUTH_FAILED)) {
1355                 ls->authenticate_fails++;
1356                 ls->last_fail_type =  ISCSI_LOGIN_FAIL_AUTHENTICATE;
1357         } else if ((status_class == ISCSI_STATUS_CLS_INITIATOR_ERR)  &&
1358                  (status_detail == ISCSI_LOGIN_STATUS_TGT_FORBIDDEN)) {
1359                 ls->authorize_fails++;
1360                 ls->last_fail_type = ISCSI_LOGIN_FAIL_AUTHORIZE;
1361         } else if ((status_class == ISCSI_STATUS_CLS_INITIATOR_ERR) &&
1362                  (status_detail == ISCSI_LOGIN_STATUS_INIT_ERR)) {
1363                 ls->negotiate_fails++;
1364                 ls->last_fail_type = ISCSI_LOGIN_FAIL_NEGOTIATE;
1365         } else {
1366                 ls->other_fails++;
1367                 ls->last_fail_type = ISCSI_LOGIN_FAIL_OTHER;
1368         }
1369
1370         /* Save initiator name, ip address and time, if it is a failed login */
1371         if (status_class != ISCSI_STATUS_CLS_SUCCESS) {
1372                 if (conn->param_list)
1373                         intrname = iscsi_find_param_from_key(INITIATORNAME,
1374                                                              conn->param_list);
1375                 strlcpy(ls->last_intr_fail_name,
1376                        (intrname ? intrname->value : "Unknown"),
1377                        sizeof(ls->last_intr_fail_name));
1378
1379                 ls->last_intr_fail_ip_family = conn->login_family;
1380
1381                 ls->last_intr_fail_sockaddr = conn->login_sockaddr;
1382                 ls->last_fail_time = get_jiffies_64();
1383         }
1384
1385         spin_unlock(&ls->lock);
1386 }
1387
1388 struct iscsi_tiqn *iscsit_snmp_get_tiqn(struct iscsit_conn *conn)
1389 {
1390         struct iscsi_portal_group *tpg;
1391
1392         if (!conn)
1393                 return NULL;
1394
1395         tpg = conn->tpg;
1396         if (!tpg)
1397                 return NULL;
1398
1399         if (!tpg->tpg_tiqn)
1400                 return NULL;
1401
1402         return tpg->tpg_tiqn;
1403 }
1404
1405 void iscsit_fill_cxn_timeout_err_stats(struct iscsit_session *sess)
1406 {
1407         struct iscsi_portal_group *tpg = sess->tpg;
1408         struct iscsi_tiqn *tiqn = tpg->tpg_tiqn;
1409
1410         if (!tiqn)
1411                 return;
1412
1413         spin_lock_bh(&tiqn->sess_err_stats.lock);
1414         strlcpy(tiqn->sess_err_stats.last_sess_fail_rem_name,
1415                         sess->sess_ops->InitiatorName,
1416                         sizeof(tiqn->sess_err_stats.last_sess_fail_rem_name));
1417         tiqn->sess_err_stats.last_sess_failure_type =
1418                         ISCSI_SESS_ERR_CXN_TIMEOUT;
1419         tiqn->sess_err_stats.cxn_timeout_errors++;
1420         atomic_long_inc(&sess->conn_timeout_errors);
1421         spin_unlock_bh(&tiqn->sess_err_stats.lock);
1422 }