drivers/target/iscsi/iscsi_target_util.c

   1 /*******************************************************************************
   2  * This file contains the iSCSI Target specific utility functions.
   3  *
   4  * (c) Copyright 2007-2013 Datera, Inc.
   5  *
   6  * Author: Nicholas A. Bellinger <nab@linux-iscsi.org>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  ******************************************************************************/
  18
  19 #include <linux/list.h>
  20 #include <linux/percpu_ida.h>
  21 #include <net/ipv6.h>         /* ipv6_addr_equal() */
  22 #include <scsi/scsi_tcq.h>
  23 #include <scsi/iscsi_proto.h>
  24 #include <target/target_core_base.h>
  25 #include <target/target_core_fabric.h>
  26 #include <target/iscsi/iscsi_transport.h>
  27
  28 #include <target/iscsi/iscsi_target_core.h>
  29 #include "iscsi_target_parameters.h"
  30 #include "iscsi_target_seq_pdu_list.h"
  31 #include "iscsi_target_datain_values.h"
  32 #include "iscsi_target_erl0.h"
  33 #include "iscsi_target_erl1.h"
  34 #include "iscsi_target_erl2.h"
  35 #include "iscsi_target_tpg.h"
  36 #include "iscsi_target_util.h"
  37 #include "iscsi_target.h"
  38
  39 #define PRINT_BUFF(buff, len)                                   \
  40 {                                                               \
  41         int zzz;                                                \
  42                                                                 \
  43         pr_debug("%d:\n", __LINE__);                            \
  44         for (zzz = 0; zzz < len; zzz++) {                       \
  45                 if (zzz % 16 == 0) {                            \
  46                         if (zzz)                                \
  47                                 pr_debug("\n");                 \
  48                         pr_debug("%4i: ", zzz);                 \
  49                 }                                               \
  50                 pr_debug("%02x ", (unsigned char) (buff)[zzz]); \
  51         }                                                       \
  52         if ((len + 1) % 16)                                     \
  53                 pr_debug("\n");                                 \
  54 }
  55
  56 extern struct list_head g_tiqn_list;
  57 extern spinlock_t tiqn_lock;
  58
  59 /*
  60  *      Called with cmd->r2t_lock held.
  61  */
  62 int iscsit_add_r2t_to_list(
  63         struct iscsi_cmd *cmd,
  64         u32 offset,
  65         u32 xfer_len,
  66         int recovery,
  67         u32 r2t_sn)
  68 {
  69         struct iscsi_r2t *r2t;
  70
  71         r2t = kmem_cache_zalloc(lio_r2t_cache, GFP_ATOMIC);
  72         if (!r2t) {
  73                 pr_err("Unable to allocate memory for struct iscsi_r2t.\n");
  74                 return -1;
  75         }
  76         INIT_LIST_HEAD(&r2t->r2t_list);
  77
  78         r2t->recovery_r2t = recovery;
  79         r2t->r2t_sn = (!r2t_sn) ? cmd->r2t_sn++ : r2t_sn;
  80         r2t->offset = offset;
  81         r2t->xfer_len = xfer_len;
  82         list_add_tail(&r2t->r2t_list, &cmd->cmd_r2t_list);
  83         spin_unlock_bh(&cmd->r2t_lock);
  84
  85         iscsit_add_cmd_to_immediate_queue(cmd, cmd->conn, ISTATE_SEND_R2T);
  86
  87         spin_lock_bh(&cmd->r2t_lock);
  88         return 0;
  89 }
  90
  91 struct iscsi_r2t *iscsit_get_r2t_for_eos(
  92         struct iscsi_cmd *cmd,
  93         u32 offset,
  94         u32 length)
  95 {
  96         struct iscsi_r2t *r2t;
  97
  98         spin_lock_bh(&cmd->r2t_lock);
  99         list_for_each_entry(r2t, &cmd->cmd_r2t_list, r2t_list) {
 100                 if ((r2t->offset <= offset) &&
 101                     (r2t->offset + r2t->xfer_len) >= (offset + length)) {
 102                         spin_unlock_bh(&cmd->r2t_lock);
 103                         return r2t;
 104                 }
 105         }
 106         spin_unlock_bh(&cmd->r2t_lock);
 107
 108         pr_err("Unable to locate R2T for Offset: %u, Length:"
 109                         " %u\n", offset, length);
 110         return NULL;
 111 }
 112
 113 struct iscsi_r2t *iscsit_get_r2t_from_list(struct iscsi_cmd *cmd)
 114 {
 115         struct iscsi_r2t *r2t;
 116
 117         spin_lock_bh(&cmd->r2t_lock);
 118         list_for_each_entry(r2t, &cmd->cmd_r2t_list, r2t_list) {
 119                 if (!r2t->sent_r2t) {
 120                         spin_unlock_bh(&cmd->r2t_lock);
 121                         return r2t;
 122                 }
 123         }
 124         spin_unlock_bh(&cmd->r2t_lock);
 125
 126         pr_err("Unable to locate next R2T to send for ITT:"
 127                         " 0x%08x.\n", cmd->init_task_tag);
 128         return NULL;
 129 }
 130
 131 /*
 132  *      Called with cmd->r2t_lock held.
 133  */
 134 void iscsit_free_r2t(struct iscsi_r2t *r2t, struct iscsi_cmd *cmd)
 135 {
 136         list_del(&r2t->r2t_list);
 137         kmem_cache_free(lio_r2t_cache, r2t);
 138 }
 139
 140 void iscsit_free_r2ts_from_list(struct iscsi_cmd *cmd)
 141 {
 142         struct iscsi_r2t *r2t, *r2t_tmp;
 143
 144         spin_lock_bh(&cmd->r2t_lock);
 145         list_for_each_entry_safe(r2t, r2t_tmp, &cmd->cmd_r2t_list, r2t_list)
 146                 iscsit_free_r2t(r2t, cmd);
 147         spin_unlock_bh(&cmd->r2t_lock);
 148 }
 149
 150 /*
 151  * May be called from software interrupt (timer) context for allocating
 152  * iSCSI NopINs.
 153  */
 154 struct iscsi_cmd *iscsit_allocate_cmd(struct iscsi_conn *conn, int state)
 155 {
 156         struct iscsi_cmd *cmd;
 157         struct se_session *se_sess = conn->sess->se_sess;
 158         int size, tag;
 159
 160         tag = percpu_ida_alloc(&se_sess->sess_tag_pool, state);
 161         if (tag < 0)
 162                 return NULL;
 163
 164         size = sizeof(struct iscsi_cmd) + conn->conn_transport->priv_size;
 165         cmd = (struct iscsi_cmd *)(se_sess->sess_cmd_map + (tag * size));
 166         memset(cmd, 0, size);
 167
 168         cmd->se_cmd.map_tag = tag;
 169         cmd->conn = conn;
 170         INIT_LIST_HEAD(&cmd->i_conn_node);
 171         INIT_LIST_HEAD(&cmd->datain_list);
 172         INIT_LIST_HEAD(&cmd->cmd_r2t_list);
 173         spin_lock_init(&cmd->datain_lock);
 174         spin_lock_init(&cmd->dataout_timeout_lock);
 175         spin_lock_init(&cmd->istate_lock);
 176         spin_lock_init(&cmd->error_lock);
 177         spin_lock_init(&cmd->r2t_lock);
 178
 179         return cmd;
 180 }
 181 EXPORT_SYMBOL(iscsit_allocate_cmd);
 182
 183 struct iscsi_seq *iscsit_get_seq_holder_for_datain(
 184         struct iscsi_cmd *cmd,
 185         u32 seq_send_order)
 186 {
 187         u32 i;
 188
 189         for (i = 0; i < cmd->seq_count; i++)
 190                 if (cmd->seq_list[i].seq_send_order == seq_send_order)
 191                         return &cmd->seq_list[i];
 192
 193         return NULL;
 194 }
 195
 196 struct iscsi_seq *iscsit_get_seq_holder_for_r2t(struct iscsi_cmd *cmd)
 197 {
 198         u32 i;
 199
 200         if (!cmd->seq_list) {
 201                 pr_err("struct iscsi_cmd->seq_list is NULL!\n");
 202                 return NULL;
 203         }
 204
 205         for (i = 0; i < cmd->seq_count; i++) {
 206                 if (cmd->seq_list[i].type != SEQTYPE_NORMAL)
 207                         continue;
 208                 if (cmd->seq_list[i].seq_send_order == cmd->seq_send_order) {
 209                         cmd->seq_send_order++;
 210                         return &cmd->seq_list[i];
 211                 }
 212         }
 213
 214         return NULL;
 215 }
 216
 217 struct iscsi_r2t *iscsit_get_holder_for_r2tsn(
 218         struct iscsi_cmd *cmd,
 219         u32 r2t_sn)
 220 {
 221         struct iscsi_r2t *r2t;
 222
 223         spin_lock_bh(&cmd->r2t_lock);
 224         list_for_each_entry(r2t, &cmd->cmd_r2t_list, r2t_list) {
 225                 if (r2t->r2t_sn == r2t_sn) {
 226                         spin_unlock_bh(&cmd->r2t_lock);
 227                         return r2t;
 228                 }
 229         }
 230         spin_unlock_bh(&cmd->r2t_lock);
 231
 232         return NULL;
 233 }
 234
 235 static inline int iscsit_check_received_cmdsn(struct iscsi_session *sess, u32 cmdsn)
 236 {
 237         u32 max_cmdsn;
 238         int ret;
 239
 240         /*
 241          * This is the proper method of checking received CmdSN against
 242          * ExpCmdSN and MaxCmdSN values, as well as accounting for out
 243          * or order CmdSNs due to multiple connection sessions and/or
 244          * CRC failures.
 245          */
 246         max_cmdsn = atomic_read(&sess->max_cmd_sn);
 247         if (iscsi_sna_gt(cmdsn, max_cmdsn)) {
 248                 pr_err("Received CmdSN: 0x%08x is greater than"
 249                        " MaxCmdSN: 0x%08x, ignoring.\n", cmdsn, max_cmdsn);
 250                 ret = CMDSN_MAXCMDSN_OVERRUN;
 251
 252         } else if (cmdsn == sess->exp_cmd_sn) {
 253                 sess->exp_cmd_sn++;
 254                 pr_debug("Received CmdSN matches ExpCmdSN,"
 255                       " incremented ExpCmdSN to: 0x%08x\n",
 256                       sess->exp_cmd_sn);
 257                 ret = CMDSN_NORMAL_OPERATION;
 258
 259         } else if (iscsi_sna_gt(cmdsn, sess->exp_cmd_sn)) {
 260                 pr_debug("Received CmdSN: 0x%08x is greater"
 261                       " than ExpCmdSN: 0x%08x, not acknowledging.\n",
 262                       cmdsn, sess->exp_cmd_sn);
 263                 ret = CMDSN_HIGHER_THAN_EXP;
 264
 265         } else {
 266                 pr_err("Received CmdSN: 0x%08x is less than"
 267                        " ExpCmdSN: 0x%08x, ignoring.\n", cmdsn,
 268                        sess->exp_cmd_sn);
 269                 ret = CMDSN_LOWER_THAN_EXP;
 270         }
 271
 272         return ret;
 273 }
 274
 275 /*
 276  * Commands may be received out of order if MC/S is in use.
 277  * Ensure they are executed in CmdSN order.
 278  */
 279 int iscsit_sequence_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
 280                         unsigned char *buf, __be32 cmdsn)
 281 {
 282         int ret, cmdsn_ret;
 283         bool reject = false;
 284         u8 reason = ISCSI_REASON_BOOKMARK_NO_RESOURCES;
 285
 286         mutex_lock(&conn->sess->cmdsn_mutex);
 287
 288         cmdsn_ret = iscsit_check_received_cmdsn(conn->sess, be32_to_cpu(cmdsn));
 289         switch (cmdsn_ret) {
 290         case CMDSN_NORMAL_OPERATION:
 291                 ret = iscsit_execute_cmd(cmd, 0);
 292                 if ((ret >= 0) && !list_empty(&conn->sess->sess_ooo_cmdsn_list))
 293                         iscsit_execute_ooo_cmdsns(conn->sess);
 294                 else if (ret < 0) {
 295                         reject = true;
 296                         ret = CMDSN_ERROR_CANNOT_RECOVER;
 297                 }
 298                 break;
 299         case CMDSN_HIGHER_THAN_EXP:
 300                 ret = iscsit_handle_ooo_cmdsn(conn->sess, cmd, be32_to_cpu(cmdsn));
 301                 if (ret < 0) {
 302                         reject = true;
 303                         ret = CMDSN_ERROR_CANNOT_RECOVER;
 304                         break;
 305                 }
 306                 ret = CMDSN_HIGHER_THAN_EXP;
 307                 break;
 308         case CMDSN_LOWER_THAN_EXP:
 309         case CMDSN_MAXCMDSN_OVERRUN:
 310         default:
 311                 cmd->i_state = ISTATE_REMOVE;
 312                 iscsit_add_cmd_to_immediate_queue(cmd, conn, cmd->i_state);
 313                 /*
 314                  * Existing callers for iscsit_sequence_cmd() will silently
 315                  * ignore commands with CMDSN_LOWER_THAN_EXP, so force this
 316                  * return for CMDSN_MAXCMDSN_OVERRUN as well..
 317                  */
 318                 ret = CMDSN_LOWER_THAN_EXP;
 319                 break;
 320         }
 321         mutex_unlock(&conn->sess->cmdsn_mutex);
 322
 323         if (reject)
 324                 iscsit_reject_cmd(cmd, reason, buf);
 325
 326         return ret;
 327 }
 328 EXPORT_SYMBOL(iscsit_sequence_cmd);
 329
 330 int iscsit_check_unsolicited_dataout(struct iscsi_cmd *cmd, unsigned char *buf)
 331 {
 332         struct iscsi_conn *conn = cmd->conn;
 333         struct se_cmd *se_cmd = &cmd->se_cmd;
 334         struct iscsi_data *hdr = (struct iscsi_data *) buf;
 335         u32 payload_length = ntoh24(hdr->dlength);
 336
 337         if (conn->sess->sess_ops->InitialR2T) {
 338                 pr_err("Received unexpected unsolicited data"
 339                         " while InitialR2T=Yes, protocol error.\n");
 340                 transport_send_check_condition_and_sense(se_cmd,
 341                                 TCM_UNEXPECTED_UNSOLICITED_DATA, 0);
 342                 return -1;
 343         }
 344
 345         if ((cmd->first_burst_len + payload_length) >
 346              conn->sess->sess_ops->FirstBurstLength) {
 347                 pr_err("Total %u bytes exceeds FirstBurstLength: %u"
 348                         " for this Unsolicited DataOut Burst.\n",
 349                         (cmd->first_burst_len + payload_length),
 350                                 conn->sess->sess_ops->FirstBurstLength);
 351                 transport_send_check_condition_and_sense(se_cmd,
 352                                 TCM_INCORRECT_AMOUNT_OF_DATA, 0);
 353                 return -1;
 354         }
 355
 356         if (!(hdr->flags & ISCSI_FLAG_CMD_FINAL))
 357                 return 0;
 358
 359         if (((cmd->first_burst_len + payload_length) != cmd->se_cmd.data_length) &&
 360             ((cmd->first_burst_len + payload_length) !=
 361               conn->sess->sess_ops->FirstBurstLength)) {
 362                 pr_err("Unsolicited non-immediate data received %u"
 363                         " does not equal FirstBurstLength: %u, and does"
 364                         " not equal ExpXferLen %u.\n",
 365                         (cmd->first_burst_len + payload_length),
 366                         conn->sess->sess_ops->FirstBurstLength, cmd->se_cmd.data_length);
 367                 transport_send_check_condition_and_sense(se_cmd,
 368                                 TCM_INCORRECT_AMOUNT_OF_DATA, 0);
 369                 return -1;
 370         }
 371         return 0;
 372 }
 373
 374 struct iscsi_cmd *iscsit_find_cmd_from_itt(
 375         struct iscsi_conn *conn,
 376         itt_t init_task_tag)
 377 {
 378         struct iscsi_cmd *cmd;
 379
 380         spin_lock_bh(&conn->cmd_lock);
 381         list_for_each_entry(cmd, &conn->conn_cmd_list, i_conn_node) {
 382                 if (cmd->init_task_tag == init_task_tag) {
 383                         spin_unlock_bh(&conn->cmd_lock);
 384                         return cmd;
 385                 }
 386         }
 387         spin_unlock_bh(&conn->cmd_lock);
 388
 389         pr_err("Unable to locate ITT: 0x%08x on CID: %hu",
 390                         init_task_tag, conn->cid);
 391         return NULL;
 392 }
 393 EXPORT_SYMBOL(iscsit_find_cmd_from_itt);
 394
 395 struct iscsi_cmd *iscsit_find_cmd_from_itt_or_dump(
 396         struct iscsi_conn *conn,
 397         itt_t init_task_tag,
 398         u32 length)
 399 {
 400         struct iscsi_cmd *cmd;
 401
 402         spin_lock_bh(&conn->cmd_lock);
 403         list_for_each_entry(cmd, &conn->conn_cmd_list, i_conn_node) {
 404                 if (cmd->cmd_flags & ICF_GOT_LAST_DATAOUT)
 405                         continue;
 406                 if (cmd->init_task_tag == init_task_tag) {
 407                         spin_unlock_bh(&conn->cmd_lock);
 408                         return cmd;
 409                 }
 410         }
 411         spin_unlock_bh(&conn->cmd_lock);
 412
 413         pr_err("Unable to locate ITT: 0x%08x on CID: %hu,"
 414                         " dumping payload\n", init_task_tag, conn->cid);
 415         if (length)
 416                 iscsit_dump_data_payload(conn, length, 1);
 417
 418         return NULL;
 419 }
 420 EXPORT_SYMBOL(iscsit_find_cmd_from_itt_or_dump);
 421
 422 struct iscsi_cmd *iscsit_find_cmd_from_ttt(
 423         struct iscsi_conn *conn,
 424         u32 targ_xfer_tag)
 425 {
 426         struct iscsi_cmd *cmd = NULL;
 427
 428         spin_lock_bh(&conn->cmd_lock);
 429         list_for_each_entry(cmd, &conn->conn_cmd_list, i_conn_node) {
 430                 if (cmd->targ_xfer_tag == targ_xfer_tag) {
 431                         spin_unlock_bh(&conn->cmd_lock);
 432                         return cmd;
 433                 }
 434         }
 435         spin_unlock_bh(&conn->cmd_lock);
 436
 437         pr_err("Unable to locate TTT: 0x%08x on CID: %hu\n",
 438                         targ_xfer_tag, conn->cid);
 439         return NULL;
 440 }
 441
 442 int iscsit_find_cmd_for_recovery(
 443         struct iscsi_session *sess,
 444         struct iscsi_cmd **cmd_ptr,
 445         struct iscsi_conn_recovery **cr_ptr,
 446         itt_t init_task_tag)
 447 {
 448         struct iscsi_cmd *cmd = NULL;
 449         struct iscsi_conn_recovery *cr;
 450         /*
 451          * Scan through the inactive connection recovery list's command list.
 452          * If init_task_tag matches the command is still alligent.
 453          */
 454         spin_lock(&sess->cr_i_lock);
 455         list_for_each_entry(cr, &sess->cr_inactive_list, cr_list) {
 456                 spin_lock(&cr->conn_recovery_cmd_lock);
 457                 list_for_each_entry(cmd, &cr->conn_recovery_cmd_list, i_conn_node) {
 458                         if (cmd->init_task_tag == init_task_tag) {
 459                                 spin_unlock(&cr->conn_recovery_cmd_lock);
 460                                 spin_unlock(&sess->cr_i_lock);
 461
 462                                 *cr_ptr = cr;
 463                                 *cmd_ptr = cmd;
 464                                 return -2;
 465                         }
 466                 }
 467                 spin_unlock(&cr->conn_recovery_cmd_lock);
 468         }
 469         spin_unlock(&sess->cr_i_lock);
 470         /*
 471          * Scan through the active connection recovery list's command list.
 472          * If init_task_tag matches the command is ready to be reassigned.
 473          */
 474         spin_lock(&sess->cr_a_lock);
 475         list_for_each_entry(cr, &sess->cr_active_list, cr_list) {
 476                 spin_lock(&cr->conn_recovery_cmd_lock);
 477                 list_for_each_entry(cmd, &cr->conn_recovery_cmd_list, i_conn_node) {
 478                         if (cmd->init_task_tag == init_task_tag) {
 479                                 spin_unlock(&cr->conn_recovery_cmd_lock);
 480                                 spin_unlock(&sess->cr_a_lock);
 481
 482                                 *cr_ptr = cr;
 483                                 *cmd_ptr = cmd;
 484                                 return 0;
 485                         }
 486                 }
 487                 spin_unlock(&cr->conn_recovery_cmd_lock);
 488         }
 489         spin_unlock(&sess->cr_a_lock);
 490
 491         return -1;
 492 }
 493
 494 void iscsit_add_cmd_to_immediate_queue(
 495         struct iscsi_cmd *cmd,
 496         struct iscsi_conn *conn,
 497         u8 state)
 498 {
 499         struct iscsi_queue_req *qr;
 500
 501         qr = kmem_cache_zalloc(lio_qr_cache, GFP_ATOMIC);
 502         if (!qr) {
 503                 pr_err("Unable to allocate memory for"
 504                                 " struct iscsi_queue_req\n");
 505                 return;
 506         }
 507         INIT_LIST_HEAD(&qr->qr_list);
 508         qr->cmd = cmd;
 509         qr->state = state;
 510
 511         spin_lock_bh(&conn->immed_queue_lock);
 512         list_add_tail(&qr->qr_list, &conn->immed_queue_list);
 513         atomic_inc(&cmd->immed_queue_count);
 514         atomic_set(&conn->check_immediate_queue, 1);
 515         spin_unlock_bh(&conn->immed_queue_lock);
 516
 517         wake_up(&conn->queues_wq);
 518 }
 519 EXPORT_SYMBOL(iscsit_add_cmd_to_immediate_queue);
 520
 521 struct iscsi_queue_req *iscsit_get_cmd_from_immediate_queue(struct iscsi_conn *conn)
 522 {
 523         struct iscsi_queue_req *qr;
 524
 525         spin_lock_bh(&conn->immed_queue_lock);
 526         if (list_empty(&conn->immed_queue_list)) {
 527                 spin_unlock_bh(&conn->immed_queue_lock);
 528                 return NULL;
 529         }
 530         qr = list_first_entry(&conn->immed_queue_list,
 531                               struct iscsi_queue_req, qr_list);
 532
 533         list_del(&qr->qr_list);
 534         if (qr->cmd)
 535                 atomic_dec(&qr->cmd->immed_queue_count);
 536         spin_unlock_bh(&conn->immed_queue_lock);
 537
 538         return qr;
 539 }
 540
 541 static void iscsit_remove_cmd_from_immediate_queue(
 542         struct iscsi_cmd *cmd,
 543         struct iscsi_conn *conn)
 544 {
 545         struct iscsi_queue_req *qr, *qr_tmp;
 546
 547         spin_lock_bh(&conn->immed_queue_lock);
 548         if (!atomic_read(&cmd->immed_queue_count)) {
 549                 spin_unlock_bh(&conn->immed_queue_lock);
 550                 return;
 551         }
 552
 553         list_for_each_entry_safe(qr, qr_tmp, &conn->immed_queue_list, qr_list) {
 554                 if (qr->cmd != cmd)
 555                         continue;
 556
 557                 atomic_dec(&qr->cmd->immed_queue_count);
 558                 list_del(&qr->qr_list);
 559                 kmem_cache_free(lio_qr_cache, qr);
 560         }
 561         spin_unlock_bh(&conn->immed_queue_lock);
 562
 563         if (atomic_read(&cmd->immed_queue_count)) {
 564                 pr_err("ITT: 0x%08x immed_queue_count: %d\n",
 565                         cmd->init_task_tag,
 566                         atomic_read(&cmd->immed_queue_count));
 567         }
 568 }
 569
 570 void iscsit_add_cmd_to_response_queue(
 571         struct iscsi_cmd *cmd,
 572         struct iscsi_conn *conn,
 573         u8 state)
 574 {
 575         struct iscsi_queue_req *qr;
 576
 577         qr = kmem_cache_zalloc(lio_qr_cache, GFP_ATOMIC);
 578         if (!qr) {
 579                 pr_err("Unable to allocate memory for"
 580                         " struct iscsi_queue_req\n");
 581                 return;
 582         }
 583         INIT_LIST_HEAD(&qr->qr_list);
 584         qr->cmd = cmd;
 585         qr->state = state;
 586
 587         spin_lock_bh(&conn->response_queue_lock);
 588         list_add_tail(&qr->qr_list, &conn->response_queue_list);
 589         atomic_inc(&cmd->response_queue_count);
 590         spin_unlock_bh(&conn->response_queue_lock);
 591
 592         wake_up(&conn->queues_wq);
 593 }
 594
 595 struct iscsi_queue_req *iscsit_get_cmd_from_response_queue(struct iscsi_conn *conn)
 596 {
 597         struct iscsi_queue_req *qr;
 598
 599         spin_lock_bh(&conn->response_queue_lock);
 600         if (list_empty(&conn->response_queue_list)) {
 601                 spin_unlock_bh(&conn->response_queue_lock);
 602                 return NULL;
 603         }
 604
 605         qr = list_first_entry(&conn->response_queue_list,
 606                               struct iscsi_queue_req, qr_list);
 607
 608         list_del(&qr->qr_list);
 609         if (qr->cmd)
 610                 atomic_dec(&qr->cmd->response_queue_count);
 611         spin_unlock_bh(&conn->response_queue_lock);
 612
 613         return qr;
 614 }
 615
 616 static void iscsit_remove_cmd_from_response_queue(
 617         struct iscsi_cmd *cmd,
 618         struct iscsi_conn *conn)
 619 {
 620         struct iscsi_queue_req *qr, *qr_tmp;
 621
 622         spin_lock_bh(&conn->response_queue_lock);
 623         if (!atomic_read(&cmd->response_queue_count)) {
 624                 spin_unlock_bh(&conn->response_queue_lock);
 625                 return;
 626         }
 627
 628         list_for_each_entry_safe(qr, qr_tmp, &conn->response_queue_list,
 629                                 qr_list) {
 630                 if (qr->cmd != cmd)
 631                         continue;
 632
 633                 atomic_dec(&qr->cmd->response_queue_count);
 634                 list_del(&qr->qr_list);
 635                 kmem_cache_free(lio_qr_cache, qr);
 636         }
 637         spin_unlock_bh(&conn->response_queue_lock);
 638
 639         if (atomic_read(&cmd->response_queue_count)) {
 640                 pr_err("ITT: 0x%08x response_queue_count: %d\n",
 641                         cmd->init_task_tag,
 642                         atomic_read(&cmd->response_queue_count));
 643         }
 644 }
 645
 646 bool iscsit_conn_all_queues_empty(struct iscsi_conn *conn)
 647 {
 648         bool empty;
 649
 650         spin_lock_bh(&conn->immed_queue_lock);
 651         empty = list_empty(&conn->immed_queue_list);
 652         spin_unlock_bh(&conn->immed_queue_lock);
 653
 654         if (!empty)
 655                 return empty;
 656
 657         spin_lock_bh(&conn->response_queue_lock);
 658         empty = list_empty(&conn->response_queue_list);
 659         spin_unlock_bh(&conn->response_queue_lock);
 660
 661         return empty;
 662 }
 663
 664 void iscsit_free_queue_reqs_for_conn(struct iscsi_conn *conn)
 665 {
 666         struct iscsi_queue_req *qr, *qr_tmp;
 667
 668         spin_lock_bh(&conn->immed_queue_lock);
 669         list_for_each_entry_safe(qr, qr_tmp, &conn->immed_queue_list, qr_list) {
 670                 list_del(&qr->qr_list);
 671                 if (qr->cmd)
 672                         atomic_dec(&qr->cmd->immed_queue_count);
 673
 674                 kmem_cache_free(lio_qr_cache, qr);
 675         }
 676         spin_unlock_bh(&conn->immed_queue_lock);
 677
 678         spin_lock_bh(&conn->response_queue_lock);
 679         list_for_each_entry_safe(qr, qr_tmp, &conn->response_queue_list,
 680                         qr_list) {
 681                 list_del(&qr->qr_list);
 682                 if (qr->cmd)
 683                         atomic_dec(&qr->cmd->response_queue_count);
 684
 685                 kmem_cache_free(lio_qr_cache, qr);
 686         }
 687         spin_unlock_bh(&conn->response_queue_lock);
 688 }
 689
 690 void iscsit_release_cmd(struct iscsi_cmd *cmd)
 691 {
 692         struct iscsi_session *sess;
 693         struct se_cmd *se_cmd = &cmd->se_cmd;
 694
 695         if (cmd->conn)
 696                 sess = cmd->conn->sess;
 697         else
 698                 sess = cmd->sess;
 699
 700         BUG_ON(!sess || !sess->se_sess);
 701
 702         kfree(cmd->buf_ptr);
 703         kfree(cmd->pdu_list);
 704         kfree(cmd->seq_list);
 705         kfree(cmd->tmr_req);
 706         kfree(cmd->iov_data);
 707         kfree(cmd->text_in_ptr);
 708
 709         percpu_ida_free(&sess->se_sess->sess_tag_pool, se_cmd->map_tag);
 710 }
 711 EXPORT_SYMBOL(iscsit_release_cmd);
 712
 713 void __iscsit_free_cmd(struct iscsi_cmd *cmd, bool scsi_cmd,
 714                        bool check_queues)
 715 {
 716         struct iscsi_conn *conn = cmd->conn;
 717
 718         if (scsi_cmd) {
 719                 if (cmd->data_direction == DMA_TO_DEVICE) {
 720                         iscsit_stop_dataout_timer(cmd);
 721                         iscsit_free_r2ts_from_list(cmd);
 722                 }
 723                 if (cmd->data_direction == DMA_FROM_DEVICE)
 724                         iscsit_free_all_datain_reqs(cmd);
 725         }
 726
 727         if (conn && check_queues) {
 728                 iscsit_remove_cmd_from_immediate_queue(cmd, conn);
 729                 iscsit_remove_cmd_from_response_queue(cmd, conn);
 730         }
 731
 732         if (conn && conn->conn_transport->iscsit_release_cmd)
 733                 conn->conn_transport->iscsit_release_cmd(conn, cmd);
 734 }
 735
 736 void iscsit_free_cmd(struct iscsi_cmd *cmd, bool shutdown)
 737 {
 738         struct se_cmd *se_cmd = NULL;
 739         int rc;
 740         /*
 741          * Determine if a struct se_cmd is associated with
 742          * this struct iscsi_cmd.
 743          */
 744         switch (cmd->iscsi_opcode) {
 745         case ISCSI_OP_SCSI_CMD:
 746                 se_cmd = &cmd->se_cmd;
 747                 __iscsit_free_cmd(cmd, true, shutdown);
 748                 /*
 749                  * Fallthrough
 750                  */
 751         case ISCSI_OP_SCSI_TMFUNC:
 752                 rc = transport_generic_free_cmd(&cmd->se_cmd, shutdown);
 753                 if (!rc && shutdown && se_cmd && se_cmd->se_sess) {
 754                         __iscsit_free_cmd(cmd, true, shutdown);
 755                         target_put_sess_cmd(se_cmd);
 756                 }
 757                 break;
 758         case ISCSI_OP_REJECT:
 759                 /*
 760                  * Handle special case for REJECT when iscsi_add_reject*() has
 761                  * overwritten the original iscsi_opcode assignment, and the
 762                  * associated cmd->se_cmd needs to be released.
 763                  */
 764                 if (cmd->se_cmd.se_tfo != NULL) {
 765                         se_cmd = &cmd->se_cmd;
 766                         __iscsit_free_cmd(cmd, true, shutdown);
 767
 768                         rc = transport_generic_free_cmd(&cmd->se_cmd, shutdown);
 769                         if (!rc && shutdown && se_cmd->se_sess) {
 770                                 __iscsit_free_cmd(cmd, true, shutdown);
 771                                 target_put_sess_cmd(se_cmd);
 772                         }
 773                         break;
 774                 }
 775                 /* Fall-through */
 776         default:
 777                 __iscsit_free_cmd(cmd, false, shutdown);
 778                 iscsit_release_cmd(cmd);
 779                 break;
 780         }
 781 }
 782 EXPORT_SYMBOL(iscsit_free_cmd);
 783
 784 int iscsit_check_session_usage_count(struct iscsi_session *sess)
 785 {
 786         spin_lock_bh(&sess->session_usage_lock);
 787         if (sess->session_usage_count != 0) {
 788                 sess->session_waiting_on_uc = 1;
 789                 spin_unlock_bh(&sess->session_usage_lock);
 790                 if (in_interrupt())
 791                         return 2;
 792
 793                 wait_for_completion(&sess->session_waiting_on_uc_comp);
 794                 return 1;
 795         }
 796         spin_unlock_bh(&sess->session_usage_lock);
 797
 798         return 0;
 799 }
 800
 801 void iscsit_dec_session_usage_count(struct iscsi_session *sess)
 802 {
 803         spin_lock_bh(&sess->session_usage_lock);
 804         sess->session_usage_count--;
 805
 806         if (!sess->session_usage_count && sess->session_waiting_on_uc)
 807                 complete(&sess->session_waiting_on_uc_comp);
 808
 809         spin_unlock_bh(&sess->session_usage_lock);
 810 }
 811
 812 void iscsit_inc_session_usage_count(struct iscsi_session *sess)
 813 {
 814         spin_lock_bh(&sess->session_usage_lock);
 815         sess->session_usage_count++;
 816         spin_unlock_bh(&sess->session_usage_lock);
 817 }
 818
 819 struct iscsi_conn *iscsit_get_conn_from_cid(struct iscsi_session *sess, u16 cid)
 820 {
 821         struct iscsi_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                     (conn->conn_state == TARG_CONN_STATE_LOGGED_IN)) {
 827                         iscsit_inc_conn_usage_count(conn);
 828                         spin_unlock_bh(&sess->conn_lock);
 829                         return conn;
 830                 }
 831         }
 832         spin_unlock_bh(&sess->conn_lock);
 833
 834         return NULL;
 835 }
 836
 837 struct iscsi_conn *iscsit_get_conn_from_cid_rcfr(struct iscsi_session *sess, u16 cid)
 838 {
 839         struct iscsi_conn *conn;
 840
 841         spin_lock_bh(&sess->conn_lock);
 842         list_for_each_entry(conn, &sess->sess_conn_list, conn_list) {
 843                 if (conn->cid == cid) {
 844                         iscsit_inc_conn_usage_count(conn);
 845                         spin_lock(&conn->state_lock);
 846                         atomic_set(&conn->connection_wait_rcfr, 1);
 847                         spin_unlock(&conn->state_lock);
 848                         spin_unlock_bh(&sess->conn_lock);
 849                         return conn;
 850                 }
 851         }
 852         spin_unlock_bh(&sess->conn_lock);
 853
 854         return NULL;
 855 }
 856
 857 void iscsit_check_conn_usage_count(struct iscsi_conn *conn)
 858 {
 859         spin_lock_bh(&conn->conn_usage_lock);
 860         if (conn->conn_usage_count != 0) {
 861                 conn->conn_waiting_on_uc = 1;
 862                 spin_unlock_bh(&conn->conn_usage_lock);
 863
 864                 wait_for_completion(&conn->conn_waiting_on_uc_comp);
 865                 return;
 866         }
 867         spin_unlock_bh(&conn->conn_usage_lock);
 868 }
 869
 870 void iscsit_dec_conn_usage_count(struct iscsi_conn *conn)
 871 {
 872         spin_lock_bh(&conn->conn_usage_lock);
 873         conn->conn_usage_count--;
 874
 875         if (!conn->conn_usage_count && conn->conn_waiting_on_uc)
 876                 complete(&conn->conn_waiting_on_uc_comp);
 877
 878         spin_unlock_bh(&conn->conn_usage_lock);
 879 }
 880
 881 void iscsit_inc_conn_usage_count(struct iscsi_conn *conn)
 882 {
 883         spin_lock_bh(&conn->conn_usage_lock);
 884         conn->conn_usage_count++;
 885         spin_unlock_bh(&conn->conn_usage_lock);
 886 }
 887
 888 static int iscsit_add_nopin(struct iscsi_conn *conn, int want_response)
 889 {
 890         u8 state;
 891         struct iscsi_cmd *cmd;
 892
 893         cmd = iscsit_allocate_cmd(conn, TASK_RUNNING);
 894         if (!cmd)
 895                 return -1;
 896
 897         cmd->iscsi_opcode = ISCSI_OP_NOOP_IN;
 898         state = (want_response) ? ISTATE_SEND_NOPIN_WANT_RESPONSE :
 899                                 ISTATE_SEND_NOPIN_NO_RESPONSE;
 900         cmd->init_task_tag = RESERVED_ITT;
 901         cmd->targ_xfer_tag = (want_response) ?
 902                              session_get_next_ttt(conn->sess) : 0xFFFFFFFF;
 903         spin_lock_bh(&conn->cmd_lock);
 904         list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
 905         spin_unlock_bh(&conn->cmd_lock);
 906
 907         if (want_response)
 908                 iscsit_start_nopin_response_timer(conn);
 909         iscsit_add_cmd_to_immediate_queue(cmd, conn, state);
 910
 911         return 0;
 912 }
 913
 914 static void iscsit_handle_nopin_response_timeout(unsigned long data)
 915 {
 916         struct iscsi_conn *conn = (struct iscsi_conn *) data;
 917
 918         iscsit_inc_conn_usage_count(conn);
 919
 920         spin_lock_bh(&conn->nopin_timer_lock);
 921         if (conn->nopin_response_timer_flags & ISCSI_TF_STOP) {
 922                 spin_unlock_bh(&conn->nopin_timer_lock);
 923                 iscsit_dec_conn_usage_count(conn);
 924                 return;
 925         }
 926
 927         pr_debug("Did not receive response to NOPIN on CID: %hu on"
 928                 " SID: %u, failing connection.\n", conn->cid,
 929                         conn->sess->sid);
 930         conn->nopin_response_timer_flags &= ~ISCSI_TF_RUNNING;
 931         spin_unlock_bh(&conn->nopin_timer_lock);
 932
 933         {
 934         struct iscsi_portal_group *tpg = conn->sess->tpg;
 935         struct iscsi_tiqn *tiqn = tpg->tpg_tiqn;
 936
 937         if (tiqn) {
 938                 spin_lock_bh(&tiqn->sess_err_stats.lock);
 939                 strcpy(tiqn->sess_err_stats.last_sess_fail_rem_name,
 940                                 conn->sess->sess_ops->InitiatorName);
 941                 tiqn->sess_err_stats.last_sess_failure_type =
 942                                 ISCSI_SESS_ERR_CXN_TIMEOUT;
 943                 tiqn->sess_err_stats.cxn_timeout_errors++;
 944                 atomic_long_inc(&conn->sess->conn_timeout_errors);
 945                 spin_unlock_bh(&tiqn->sess_err_stats.lock);
 946         }
 947         }
 948
 949         iscsit_cause_connection_reinstatement(conn, 0);
 950         iscsit_dec_conn_usage_count(conn);
 951 }
 952
 953 void iscsit_mod_nopin_response_timer(struct iscsi_conn *conn)
 954 {
 955         struct iscsi_session *sess = conn->sess;
 956         struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
 957
 958         spin_lock_bh(&conn->nopin_timer_lock);
 959         if (!(conn->nopin_response_timer_flags & ISCSI_TF_RUNNING)) {
 960                 spin_unlock_bh(&conn->nopin_timer_lock);
 961                 return;
 962         }
 963
 964         mod_timer(&conn->nopin_response_timer,
 965                 (get_jiffies_64() + na->nopin_response_timeout * HZ));
 966         spin_unlock_bh(&conn->nopin_timer_lock);
 967 }
 968
 969 /*
 970  *      Called with conn->nopin_timer_lock held.
 971  */
 972 void iscsit_start_nopin_response_timer(struct iscsi_conn *conn)
 973 {
 974         struct iscsi_session *sess = conn->sess;
 975         struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
 976
 977         spin_lock_bh(&conn->nopin_timer_lock);
 978         if (conn->nopin_response_timer_flags & ISCSI_TF_RUNNING) {
 979                 spin_unlock_bh(&conn->nopin_timer_lock);
 980                 return;
 981         }
 982
 983         init_timer(&conn->nopin_response_timer);
 984         conn->nopin_response_timer.expires =
 985                 (get_jiffies_64() + na->nopin_response_timeout * HZ);
 986         conn->nopin_response_timer.data = (unsigned long)conn;
 987         conn->nopin_response_timer.function = iscsit_handle_nopin_response_timeout;
 988         conn->nopin_response_timer_flags &= ~ISCSI_TF_STOP;
 989         conn->nopin_response_timer_flags |= ISCSI_TF_RUNNING;
 990         add_timer(&conn->nopin_response_timer);
 991
 992         pr_debug("Started NOPIN Response Timer on CID: %d to %u"
 993                 " seconds\n", conn->cid, na->nopin_response_timeout);
 994         spin_unlock_bh(&conn->nopin_timer_lock);
 995 }
 996
 997 void iscsit_stop_nopin_response_timer(struct iscsi_conn *conn)
 998 {
 999         spin_lock_bh(&conn->nopin_timer_lock);
1000         if (!(conn->nopin_response_timer_flags & ISCSI_TF_RUNNING)) {
1001                 spin_unlock_bh(&conn->nopin_timer_lock);
1002                 return;
1003         }
1004         conn->nopin_response_timer_flags |= ISCSI_TF_STOP;
1005         spin_unlock_bh(&conn->nopin_timer_lock);
1006
1007         del_timer_sync(&conn->nopin_response_timer);
1008
1009         spin_lock_bh(&conn->nopin_timer_lock);
1010         conn->nopin_response_timer_flags &= ~ISCSI_TF_RUNNING;
1011         spin_unlock_bh(&conn->nopin_timer_lock);
1012 }
1013
1014 static void iscsit_handle_nopin_timeout(unsigned long data)
1015 {
1016         struct iscsi_conn *conn = (struct iscsi_conn *) data;
1017
1018         iscsit_inc_conn_usage_count(conn);
1019
1020         spin_lock_bh(&conn->nopin_timer_lock);
1021         if (conn->nopin_timer_flags & ISCSI_TF_STOP) {
1022                 spin_unlock_bh(&conn->nopin_timer_lock);
1023                 iscsit_dec_conn_usage_count(conn);
1024                 return;
1025         }
1026         conn->nopin_timer_flags &= ~ISCSI_TF_RUNNING;
1027         spin_unlock_bh(&conn->nopin_timer_lock);
1028
1029         iscsit_add_nopin(conn, 1);
1030         iscsit_dec_conn_usage_count(conn);
1031 }
1032
1033 /*
1034  * Called with conn->nopin_timer_lock held.
1035  */
1036 void __iscsit_start_nopin_timer(struct iscsi_conn *conn)
1037 {
1038         struct iscsi_session *sess = conn->sess;
1039         struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
1040         /*
1041         * NOPIN timeout is disabled.
1042          */
1043         if (!na->nopin_timeout)
1044                 return;
1045
1046         if (conn->nopin_timer_flags & ISCSI_TF_RUNNING)
1047                 return;
1048
1049         init_timer(&conn->nopin_timer);
1050         conn->nopin_timer.expires = (get_jiffies_64() + na->nopin_timeout * HZ);
1051         conn->nopin_timer.data = (unsigned long)conn;
1052         conn->nopin_timer.function = iscsit_handle_nopin_timeout;
1053         conn->nopin_timer_flags &= ~ISCSI_TF_STOP;
1054         conn->nopin_timer_flags |= ISCSI_TF_RUNNING;
1055         add_timer(&conn->nopin_timer);
1056
1057         pr_debug("Started NOPIN Timer on CID: %d at %u second"
1058                 " interval\n", conn->cid, na->nopin_timeout);
1059 }
1060
1061 void iscsit_start_nopin_timer(struct iscsi_conn *conn)
1062 {
1063         struct iscsi_session *sess = conn->sess;
1064         struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
1065         /*
1066          * NOPIN timeout is disabled..
1067          */
1068         if (!na->nopin_timeout)
1069                 return;
1070
1071         spin_lock_bh(&conn->nopin_timer_lock);
1072         if (conn->nopin_timer_flags & ISCSI_TF_RUNNING) {
1073                 spin_unlock_bh(&conn->nopin_timer_lock);
1074                 return;
1075         }
1076
1077         init_timer(&conn->nopin_timer);
1078         conn->nopin_timer.expires = (get_jiffies_64() + na->nopin_timeout * HZ);
1079         conn->nopin_timer.data = (unsigned long)conn;
1080         conn->nopin_timer.function = iscsit_handle_nopin_timeout;
1081         conn->nopin_timer_flags &= ~ISCSI_TF_STOP;
1082         conn->nopin_timer_flags |= ISCSI_TF_RUNNING;
1083         add_timer(&conn->nopin_timer);
1084
1085         pr_debug("Started NOPIN Timer on CID: %d at %u second"
1086                         " interval\n", conn->cid, na->nopin_timeout);
1087         spin_unlock_bh(&conn->nopin_timer_lock);
1088 }
1089
1090 void iscsit_stop_nopin_timer(struct iscsi_conn *conn)
1091 {
1092         spin_lock_bh(&conn->nopin_timer_lock);
1093         if (!(conn->nopin_timer_flags & ISCSI_TF_RUNNING)) {
1094                 spin_unlock_bh(&conn->nopin_timer_lock);
1095                 return;
1096         }
1097         conn->nopin_timer_flags |= ISCSI_TF_STOP;
1098         spin_unlock_bh(&conn->nopin_timer_lock);
1099
1100         del_timer_sync(&conn->nopin_timer);
1101
1102         spin_lock_bh(&conn->nopin_timer_lock);
1103         conn->nopin_timer_flags &= ~ISCSI_TF_RUNNING;
1104         spin_unlock_bh(&conn->nopin_timer_lock);
1105 }
1106
1107 int iscsit_send_tx_data(
1108         struct iscsi_cmd *cmd,
1109         struct iscsi_conn *conn,
1110         int use_misc)
1111 {
1112         int tx_sent, tx_size;
1113         u32 iov_count;
1114         struct kvec *iov;
1115
1116 send_data:
1117         tx_size = cmd->tx_size;
1118
1119         if (!use_misc) {
1120                 iov = &cmd->iov_data[0];
1121                 iov_count = cmd->iov_data_count;
1122         } else {
1123                 iov = &cmd->iov_misc[0];
1124                 iov_count = cmd->iov_misc_count;
1125         }
1126
1127         tx_sent = tx_data(conn, &iov[0], iov_count, tx_size);
1128         if (tx_size != tx_sent) {
1129                 if (tx_sent == -EAGAIN) {
1130                         pr_err("tx_data() returned -EAGAIN\n");
1131                         goto send_data;
1132                 } else
1133                         return -1;
1134         }
1135         cmd->tx_size = 0;
1136
1137         return 0;
1138 }
1139
1140 int iscsit_fe_sendpage_sg(
1141         struct iscsi_cmd *cmd,
1142         struct iscsi_conn *conn)
1143 {
1144         struct scatterlist *sg = cmd->first_data_sg;
1145         struct kvec iov;
1146         u32 tx_hdr_size, data_len;
1147         u32 offset = cmd->first_data_sg_off;
1148         int tx_sent, iov_off;
1149
1150 send_hdr:
1151         tx_hdr_size = ISCSI_HDR_LEN;
1152         if (conn->conn_ops->HeaderDigest)
1153                 tx_hdr_size += ISCSI_CRC_LEN;
1154
1155         iov.iov_base = cmd->pdu;
1156         iov.iov_len = tx_hdr_size;
1157
1158         tx_sent = tx_data(conn, &iov, 1, tx_hdr_size);
1159         if (tx_hdr_size != tx_sent) {
1160                 if (tx_sent == -EAGAIN) {
1161                         pr_err("tx_data() returned -EAGAIN\n");
1162                         goto send_hdr;
1163                 }
1164                 return -1;
1165         }
1166
1167         data_len = cmd->tx_size - tx_hdr_size - cmd->padding;
1168         /*
1169          * Set iov_off used by padding and data digest tx_data() calls below
1170          * in order to determine proper offset into cmd->iov_data[]
1171          */
1172         if (conn->conn_ops->DataDigest) {
1173                 data_len -= ISCSI_CRC_LEN;
1174                 if (cmd->padding)
1175                         iov_off = (cmd->iov_data_count - 2);
1176                 else
1177                         iov_off = (cmd->iov_data_count - 1);
1178         } else {
1179                 iov_off = (cmd->iov_data_count - 1);
1180         }
1181         /*
1182          * Perform sendpage() for each page in the scatterlist
1183          */
1184         while (data_len) {
1185                 u32 space = (sg->length - offset);
1186                 u32 sub_len = min_t(u32, data_len, space);
1187 send_pg:
1188                 tx_sent = conn->sock->ops->sendpage(conn->sock,
1189                                         sg_page(sg), sg->offset + offset, sub_len, 0);
1190                 if (tx_sent != sub_len) {
1191                         if (tx_sent == -EAGAIN) {
1192                                 pr_err("tcp_sendpage() returned"
1193                                                 " -EAGAIN\n");
1194                                 goto send_pg;
1195                         }
1196
1197                         pr_err("tcp_sendpage() failure: %d\n",
1198                                         tx_sent);
1199                         return -1;
1200                 }
1201
1202                 data_len -= sub_len;
1203                 offset = 0;
1204                 sg = sg_next(sg);
1205         }
1206
1207 send_padding:
1208         if (cmd->padding) {
1209                 struct kvec *iov_p = &cmd->iov_data[iov_off++];
1210
1211                 tx_sent = tx_data(conn, iov_p, 1, cmd->padding);
1212                 if (cmd->padding != tx_sent) {
1213                         if (tx_sent == -EAGAIN) {
1214                                 pr_err("tx_data() returned -EAGAIN\n");
1215                                 goto send_padding;
1216                         }
1217                         return -1;
1218                 }
1219         }
1220
1221 send_datacrc:
1222         if (conn->conn_ops->DataDigest) {
1223                 struct kvec *iov_d = &cmd->iov_data[iov_off];
1224
1225                 tx_sent = tx_data(conn, iov_d, 1, ISCSI_CRC_LEN);
1226                 if (ISCSI_CRC_LEN != tx_sent) {
1227                         if (tx_sent == -EAGAIN) {
1228                                 pr_err("tx_data() returned -EAGAIN\n");
1229                                 goto send_datacrc;
1230                         }
1231                         return -1;
1232                 }
1233         }
1234
1235         return 0;
1236 }
1237
1238 /*
1239  *      This function is used for mainly sending a ISCSI_TARG_LOGIN_RSP PDU
1240  *      back to the Initiator when an expection condition occurs with the
1241  *      errors set in status_class and status_detail.
1242  *
1243  *      Parameters:     iSCSI Connection, Status Class, Status Detail.
1244  *      Returns:        0 on success, -1 on error.
1245  */
1246 int iscsit_tx_login_rsp(struct iscsi_conn *conn, u8 status_class, u8 status_detail)
1247 {
1248         struct iscsi_login_rsp *hdr;
1249         struct iscsi_login *login = conn->conn_login;
1250
1251         login->login_failed = 1;
1252         iscsit_collect_login_stats(conn, status_class, status_detail);
1253
1254         memset(&login->rsp[0], 0, ISCSI_HDR_LEN);
1255
1256         hdr     = (struct iscsi_login_rsp *)&login->rsp[0];
1257         hdr->opcode             = ISCSI_OP_LOGIN_RSP;
1258         hdr->status_class       = status_class;
1259         hdr->status_detail      = status_detail;
1260         hdr->itt                = conn->login_itt;
1261
1262         return conn->conn_transport->iscsit_put_login_tx(conn, login, 0);
1263 }
1264
1265 void iscsit_print_session_params(struct iscsi_session *sess)
1266 {
1267         struct iscsi_conn *conn;
1268
1269         pr_debug("-----------------------------[Session Params for"
1270                 " SID: %u]-----------------------------\n", sess->sid);
1271         spin_lock_bh(&sess->conn_lock);
1272         list_for_each_entry(conn, &sess->sess_conn_list, conn_list)
1273                 iscsi_dump_conn_ops(conn->conn_ops);
1274         spin_unlock_bh(&sess->conn_lock);
1275
1276         iscsi_dump_sess_ops(sess->sess_ops);
1277 }
1278
1279 static int iscsit_do_rx_data(
1280         struct iscsi_conn *conn,
1281         struct iscsi_data_count *count)
1282 {
1283         int data = count->data_length, rx_loop = 0, total_rx = 0;
1284         struct msghdr msg;
1285
1286         if (!conn || !conn->sock || !conn->conn_ops)
1287                 return -1;
1288
1289         memset(&msg, 0, sizeof(struct msghdr));
1290         iov_iter_kvec(&msg.msg_iter, READ | ITER_KVEC,
1291                       count->iov, count->iov_count, data);
1292
1293         while (msg_data_left(&msg)) {
1294                 rx_loop = sock_recvmsg(conn->sock, &msg, MSG_WAITALL);
1295                 if (rx_loop <= 0) {
1296                         pr_debug("rx_loop: %d total_rx: %d\n",
1297                                 rx_loop, total_rx);
1298                         return rx_loop;
1299                 }
1300                 total_rx += rx_loop;
1301                 pr_debug("rx_loop: %d, total_rx: %d, data: %d\n",
1302                                 rx_loop, total_rx, data);
1303         }
1304
1305         return total_rx;
1306 }
1307
1308 int rx_data(
1309         struct iscsi_conn *conn,
1310         struct kvec *iov,
1311         int iov_count,
1312         int data)
1313 {
1314         struct iscsi_data_count c;
1315
1316         if (!conn || !conn->sock || !conn->conn_ops)
1317                 return -1;
1318
1319         memset(&c, 0, sizeof(struct iscsi_data_count));
1320         c.iov = iov;
1321         c.iov_count = iov_count;
1322         c.data_length = data;
1323         c.type = ISCSI_RX_DATA;
1324
1325         return iscsit_do_rx_data(conn, &c);
1326 }
1327
1328 int tx_data(
1329         struct iscsi_conn *conn,
1330         struct kvec *iov,
1331         int iov_count,
1332         int data)
1333 {
1334         struct msghdr msg;
1335         int total_tx = 0;
1336
1337         if (!conn || !conn->sock || !conn->conn_ops)
1338                 return -1;
1339
1340         if (data <= 0) {
1341                 pr_err("Data length is: %d\n", data);
1342                 return -1;
1343         }
1344
1345         memset(&msg, 0, sizeof(struct msghdr));
1346
1347         iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC,
1348                       iov, iov_count, data);
1349
1350         while (msg_data_left(&msg)) {
1351                 int tx_loop = sock_sendmsg(conn->sock, &msg);
1352                 if (tx_loop <= 0) {
1353                         pr_debug("tx_loop: %d total_tx %d\n",
1354                                 tx_loop, total_tx);
1355                         return tx_loop;
1356                 }
1357                 total_tx += tx_loop;
1358                 pr_debug("tx_loop: %d, total_tx: %d, data: %d\n",
1359                                         tx_loop, total_tx, data);
1360         }
1361
1362         return total_tx;
1363 }
1364
1365 void iscsit_collect_login_stats(
1366         struct iscsi_conn *conn,
1367         u8 status_class,
1368         u8 status_detail)
1369 {
1370         struct iscsi_param *intrname = NULL;
1371         struct iscsi_tiqn *tiqn;
1372         struct iscsi_login_stats *ls;
1373
1374         tiqn = iscsit_snmp_get_tiqn(conn);
1375         if (!tiqn)
1376                 return;
1377
1378         ls = &tiqn->login_stats;
1379
1380         spin_lock(&ls->lock);
1381         if (status_class == ISCSI_STATUS_CLS_SUCCESS)
1382                 ls->accepts++;
1383         else if (status_class == ISCSI_STATUS_CLS_REDIRECT) {
1384                 ls->redirects++;
1385                 ls->last_fail_type = ISCSI_LOGIN_FAIL_REDIRECT;
1386         } else if ((status_class == ISCSI_STATUS_CLS_INITIATOR_ERR)  &&
1387                  (status_detail == ISCSI_LOGIN_STATUS_AUTH_FAILED)) {
1388                 ls->authenticate_fails++;
1389                 ls->last_fail_type =  ISCSI_LOGIN_FAIL_AUTHENTICATE;
1390         } else if ((status_class == ISCSI_STATUS_CLS_INITIATOR_ERR)  &&
1391                  (status_detail == ISCSI_LOGIN_STATUS_TGT_FORBIDDEN)) {
1392                 ls->authorize_fails++;
1393                 ls->last_fail_type = ISCSI_LOGIN_FAIL_AUTHORIZE;
1394         } else if ((status_class == ISCSI_STATUS_CLS_INITIATOR_ERR) &&
1395                  (status_detail == ISCSI_LOGIN_STATUS_INIT_ERR)) {
1396                 ls->negotiate_fails++;
1397                 ls->last_fail_type = ISCSI_LOGIN_FAIL_NEGOTIATE;
1398         } else {
1399                 ls->other_fails++;
1400                 ls->last_fail_type = ISCSI_LOGIN_FAIL_OTHER;
1401         }
1402
1403         /* Save initiator name, ip address and time, if it is a failed login */
1404         if (status_class != ISCSI_STATUS_CLS_SUCCESS) {
1405                 if (conn->param_list)
1406                         intrname = iscsi_find_param_from_key(INITIATORNAME,
1407                                                              conn->param_list);
1408                 strlcpy(ls->last_intr_fail_name,
1409                        (intrname ? intrname->value : "Unknown"),
1410                        sizeof(ls->last_intr_fail_name));
1411
1412                 ls->last_intr_fail_ip_family = conn->login_family;
1413
1414                 ls->last_intr_fail_sockaddr = conn->login_sockaddr;
1415                 ls->last_fail_time = get_jiffies_64();
1416         }
1417
1418         spin_unlock(&ls->lock);
1419 }
1420
1421 struct iscsi_tiqn *iscsit_snmp_get_tiqn(struct iscsi_conn *conn)
1422 {
1423         struct iscsi_portal_group *tpg;
1424
1425         if (!conn)
1426                 return NULL;
1427
1428         tpg = conn->tpg;
1429         if (!tpg)
1430                 return NULL;
1431
1432         if (!tpg->tpg_tiqn)
1433                 return NULL;
1434
1435         return tpg->tpg_tiqn;
1436 }