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