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 int 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 -ENOMEM;
 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         return 0;
 594 }
 595
 596 struct iscsi_queue_req *iscsit_get_cmd_from_response_queue(struct iscsi_conn *conn)
 597 {
 598         struct iscsi_queue_req *qr;
 599
 600         spin_lock_bh(&conn->response_queue_lock);
 601         if (list_empty(&conn->response_queue_list)) {
 602                 spin_unlock_bh(&conn->response_queue_lock);
 603                 return NULL;
 604         }
 605
 606         qr = list_first_entry(&conn->response_queue_list,
 607                               struct iscsi_queue_req, qr_list);
 608
 609         list_del(&qr->qr_list);
 610         if (qr->cmd)
 611                 atomic_dec(&qr->cmd->response_queue_count);
 612         spin_unlock_bh(&conn->response_queue_lock);
 613
 614         return qr;
 615 }
 616
 617 static void iscsit_remove_cmd_from_response_queue(
 618         struct iscsi_cmd *cmd,
 619         struct iscsi_conn *conn)
 620 {
 621         struct iscsi_queue_req *qr, *qr_tmp;
 622
 623         spin_lock_bh(&conn->response_queue_lock);
 624         if (!atomic_read(&cmd->response_queue_count)) {
 625                 spin_unlock_bh(&conn->response_queue_lock);
 626                 return;
 627         }
 628
 629         list_for_each_entry_safe(qr, qr_tmp, &conn->response_queue_list,
 630                                 qr_list) {
 631                 if (qr->cmd != cmd)
 632                         continue;
 633
 634                 atomic_dec(&qr->cmd->response_queue_count);
 635                 list_del(&qr->qr_list);
 636                 kmem_cache_free(lio_qr_cache, qr);
 637         }
 638         spin_unlock_bh(&conn->response_queue_lock);
 639
 640         if (atomic_read(&cmd->response_queue_count)) {
 641                 pr_err("ITT: 0x%08x response_queue_count: %d\n",
 642                         cmd->init_task_tag,
 643                         atomic_read(&cmd->response_queue_count));
 644         }
 645 }
 646
 647 bool iscsit_conn_all_queues_empty(struct iscsi_conn *conn)
 648 {
 649         bool empty;
 650
 651         spin_lock_bh(&conn->immed_queue_lock);
 652         empty = list_empty(&conn->immed_queue_list);
 653         spin_unlock_bh(&conn->immed_queue_lock);
 654
 655         if (!empty)
 656                 return empty;
 657
 658         spin_lock_bh(&conn->response_queue_lock);
 659         empty = list_empty(&conn->response_queue_list);
 660         spin_unlock_bh(&conn->response_queue_lock);
 661
 662         return empty;
 663 }
 664
 665 void iscsit_free_queue_reqs_for_conn(struct iscsi_conn *conn)
 666 {
 667         struct iscsi_queue_req *qr, *qr_tmp;
 668
 669         spin_lock_bh(&conn->immed_queue_lock);
 670         list_for_each_entry_safe(qr, qr_tmp, &conn->immed_queue_list, qr_list) {
 671                 list_del(&qr->qr_list);
 672                 if (qr->cmd)
 673                         atomic_dec(&qr->cmd->immed_queue_count);
 674
 675                 kmem_cache_free(lio_qr_cache, qr);
 676         }
 677         spin_unlock_bh(&conn->immed_queue_lock);
 678
 679         spin_lock_bh(&conn->response_queue_lock);
 680         list_for_each_entry_safe(qr, qr_tmp, &conn->response_queue_list,
 681                         qr_list) {
 682                 list_del(&qr->qr_list);
 683                 if (qr->cmd)
 684                         atomic_dec(&qr->cmd->response_queue_count);
 685
 686                 kmem_cache_free(lio_qr_cache, qr);
 687         }
 688         spin_unlock_bh(&conn->response_queue_lock);
 689 }
 690
 691 void iscsit_release_cmd(struct iscsi_cmd *cmd)
 692 {
 693         struct iscsi_session *sess;
 694         struct se_cmd *se_cmd = &cmd->se_cmd;
 695
 696         if (cmd->conn)
 697                 sess = cmd->conn->sess;
 698         else
 699                 sess = cmd->sess;
 700
 701         BUG_ON(!sess || !sess->se_sess);
 702
 703         kfree(cmd->buf_ptr);
 704         kfree(cmd->pdu_list);
 705         kfree(cmd->seq_list);
 706         kfree(cmd->tmr_req);
 707         kfree(cmd->iov_data);
 708         kfree(cmd->text_in_ptr);
 709
 710         percpu_ida_free(&sess->se_sess->sess_tag_pool, se_cmd->map_tag);
 711 }
 712 EXPORT_SYMBOL(iscsit_release_cmd);
 713
 714 void __iscsit_free_cmd(struct iscsi_cmd *cmd, bool scsi_cmd,
 715                        bool check_queues)
 716 {
 717         struct iscsi_conn *conn = cmd->conn;
 718
 719         if (scsi_cmd) {
 720                 if (cmd->data_direction == DMA_TO_DEVICE) {
 721                         iscsit_stop_dataout_timer(cmd);
 722                         iscsit_free_r2ts_from_list(cmd);
 723                 }
 724                 if (cmd->data_direction == DMA_FROM_DEVICE)
 725                         iscsit_free_all_datain_reqs(cmd);
 726         }
 727
 728         if (conn && check_queues) {
 729                 iscsit_remove_cmd_from_immediate_queue(cmd, conn);
 730                 iscsit_remove_cmd_from_response_queue(cmd, conn);
 731         }
 732
 733         if (conn && conn->conn_transport->iscsit_release_cmd)
 734                 conn->conn_transport->iscsit_release_cmd(conn, cmd);
 735 }
 736
 737 void iscsit_free_cmd(struct iscsi_cmd *cmd, bool shutdown)
 738 {
 739         struct se_cmd *se_cmd = NULL;
 740         int rc;
 741         bool op_scsi = false;
 742         /*
 743          * Determine if a struct se_cmd is associated with
 744          * this struct iscsi_cmd.
 745          */
 746         switch (cmd->iscsi_opcode) {
 747         case ISCSI_OP_SCSI_CMD:
 748                 op_scsi = true;
 749                 /*
 750                  * Fallthrough
 751                  */
 752         case ISCSI_OP_SCSI_TMFUNC:
 753                 se_cmd = &cmd->se_cmd;
 754                 __iscsit_free_cmd(cmd, op_scsi, shutdown);
 755                 rc = transport_generic_free_cmd(se_cmd, shutdown);
 756                 if (!rc && shutdown && se_cmd->se_sess) {
 757                         __iscsit_free_cmd(cmd, op_scsi, shutdown);
 758                         target_put_sess_cmd(se_cmd);
 759                 }
 760                 break;
 761         case ISCSI_OP_REJECT:
 762                 /*
 763                  * Handle special case for REJECT when iscsi_add_reject*() has
 764                  * overwritten the original iscsi_opcode assignment, and the
 765                  * associated cmd->se_cmd needs to be released.
 766                  */
 767                 if (cmd->se_cmd.se_tfo != NULL) {
 768                         se_cmd = &cmd->se_cmd;
 769                         __iscsit_free_cmd(cmd, true, shutdown);
 770
 771                         rc = transport_generic_free_cmd(&cmd->se_cmd, shutdown);
 772                         if (!rc && shutdown && se_cmd->se_sess) {
 773                                 __iscsit_free_cmd(cmd, true, shutdown);
 774                                 target_put_sess_cmd(se_cmd);
 775                         }
 776                         break;
 777                 }
 778                 /* Fall-through */
 779         default:
 780                 __iscsit_free_cmd(cmd, false, shutdown);
 781                 iscsit_release_cmd(cmd);
 782                 break;
 783         }
 784 }
 785 EXPORT_SYMBOL(iscsit_free_cmd);
 786
 787 int iscsit_check_session_usage_count(struct iscsi_session *sess)
 788 {
 789         spin_lock_bh(&sess->session_usage_lock);
 790         if (sess->session_usage_count != 0) {
 791                 sess->session_waiting_on_uc = 1;
 792                 spin_unlock_bh(&sess->session_usage_lock);
 793                 if (in_interrupt())
 794                         return 2;
 795
 796                 wait_for_completion(&sess->session_waiting_on_uc_comp);
 797                 return 1;
 798         }
 799         spin_unlock_bh(&sess->session_usage_lock);
 800
 801         return 0;
 802 }
 803
 804 void iscsit_dec_session_usage_count(struct iscsi_session *sess)
 805 {
 806         spin_lock_bh(&sess->session_usage_lock);
 807         sess->session_usage_count--;
 808
 809         if (!sess->session_usage_count && sess->session_waiting_on_uc)
 810                 complete(&sess->session_waiting_on_uc_comp);
 811
 812         spin_unlock_bh(&sess->session_usage_lock);
 813 }
 814
 815 void iscsit_inc_session_usage_count(struct iscsi_session *sess)
 816 {
 817         spin_lock_bh(&sess->session_usage_lock);
 818         sess->session_usage_count++;
 819         spin_unlock_bh(&sess->session_usage_lock);
 820 }
 821
 822 struct iscsi_conn *iscsit_get_conn_from_cid(struct iscsi_session *sess, u16 cid)
 823 {
 824         struct iscsi_conn *conn;
 825
 826         spin_lock_bh(&sess->conn_lock);
 827         list_for_each_entry(conn, &sess->sess_conn_list, conn_list) {
 828                 if ((conn->cid == cid) &&
 829                     (conn->conn_state == TARG_CONN_STATE_LOGGED_IN)) {
 830                         iscsit_inc_conn_usage_count(conn);
 831                         spin_unlock_bh(&sess->conn_lock);
 832                         return conn;
 833                 }
 834         }
 835         spin_unlock_bh(&sess->conn_lock);
 836
 837         return NULL;
 838 }
 839
 840 struct iscsi_conn *iscsit_get_conn_from_cid_rcfr(struct iscsi_session *sess, u16 cid)
 841 {
 842         struct iscsi_conn *conn;
 843
 844         spin_lock_bh(&sess->conn_lock);
 845         list_for_each_entry(conn, &sess->sess_conn_list, conn_list) {
 846                 if (conn->cid == cid) {
 847                         iscsit_inc_conn_usage_count(conn);
 848                         spin_lock(&conn->state_lock);
 849                         atomic_set(&conn->connection_wait_rcfr, 1);
 850                         spin_unlock(&conn->state_lock);
 851                         spin_unlock_bh(&sess->conn_lock);
 852                         return conn;
 853                 }
 854         }
 855         spin_unlock_bh(&sess->conn_lock);
 856
 857         return NULL;
 858 }
 859
 860 void iscsit_check_conn_usage_count(struct iscsi_conn *conn)
 861 {
 862         spin_lock_bh(&conn->conn_usage_lock);
 863         if (conn->conn_usage_count != 0) {
 864                 conn->conn_waiting_on_uc = 1;
 865                 spin_unlock_bh(&conn->conn_usage_lock);
 866
 867                 wait_for_completion(&conn->conn_waiting_on_uc_comp);
 868                 return;
 869         }
 870         spin_unlock_bh(&conn->conn_usage_lock);
 871 }
 872
 873 void iscsit_dec_conn_usage_count(struct iscsi_conn *conn)
 874 {
 875         spin_lock_bh(&conn->conn_usage_lock);
 876         conn->conn_usage_count--;
 877
 878         if (!conn->conn_usage_count && conn->conn_waiting_on_uc)
 879                 complete(&conn->conn_waiting_on_uc_comp);
 880
 881         spin_unlock_bh(&conn->conn_usage_lock);
 882 }
 883
 884 void iscsit_inc_conn_usage_count(struct iscsi_conn *conn)
 885 {
 886         spin_lock_bh(&conn->conn_usage_lock);
 887         conn->conn_usage_count++;
 888         spin_unlock_bh(&conn->conn_usage_lock);
 889 }
 890
 891 static int iscsit_add_nopin(struct iscsi_conn *conn, int want_response)
 892 {
 893         u8 state;
 894         struct iscsi_cmd *cmd;
 895
 896         cmd = iscsit_allocate_cmd(conn, TASK_RUNNING);
 897         if (!cmd)
 898                 return -1;
 899
 900         cmd->iscsi_opcode = ISCSI_OP_NOOP_IN;
 901         state = (want_response) ? ISTATE_SEND_NOPIN_WANT_RESPONSE :
 902                                 ISTATE_SEND_NOPIN_NO_RESPONSE;
 903         cmd->init_task_tag = RESERVED_ITT;
 904         cmd->targ_xfer_tag = (want_response) ?
 905                              session_get_next_ttt(conn->sess) : 0xFFFFFFFF;
 906         spin_lock_bh(&conn->cmd_lock);
 907         list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
 908         spin_unlock_bh(&conn->cmd_lock);
 909
 910         if (want_response)
 911                 iscsit_start_nopin_response_timer(conn);
 912         iscsit_add_cmd_to_immediate_queue(cmd, conn, state);
 913
 914         return 0;
 915 }
 916
 917 static void iscsit_handle_nopin_response_timeout(unsigned long data)
 918 {
 919         struct iscsi_conn *conn = (struct iscsi_conn *) data;
 920
 921         iscsit_inc_conn_usage_count(conn);
 922
 923         spin_lock_bh(&conn->nopin_timer_lock);
 924         if (conn->nopin_response_timer_flags & ISCSI_TF_STOP) {
 925                 spin_unlock_bh(&conn->nopin_timer_lock);
 926                 iscsit_dec_conn_usage_count(conn);
 927                 return;
 928         }
 929
 930         pr_debug("Did not receive response to NOPIN on CID: %hu on"
 931                 " SID: %u, failing connection.\n", conn->cid,
 932                         conn->sess->sid);
 933         conn->nopin_response_timer_flags &= ~ISCSI_TF_RUNNING;
 934         spin_unlock_bh(&conn->nopin_timer_lock);
 935
 936         {
 937         struct iscsi_portal_group *tpg = conn->sess->tpg;
 938         struct iscsi_tiqn *tiqn = tpg->tpg_tiqn;
 939
 940         if (tiqn) {
 941                 spin_lock_bh(&tiqn->sess_err_stats.lock);
 942                 strcpy(tiqn->sess_err_stats.last_sess_fail_rem_name,
 943                                 conn->sess->sess_ops->InitiatorName);
 944                 tiqn->sess_err_stats.last_sess_failure_type =
 945                                 ISCSI_SESS_ERR_CXN_TIMEOUT;
 946                 tiqn->sess_err_stats.cxn_timeout_errors++;
 947                 atomic_long_inc(&conn->sess->conn_timeout_errors);
 948                 spin_unlock_bh(&tiqn->sess_err_stats.lock);
 949         }
 950         }
 951
 952         iscsit_cause_connection_reinstatement(conn, 0);
 953         iscsit_dec_conn_usage_count(conn);
 954 }
 955
 956 void iscsit_mod_nopin_response_timer(struct iscsi_conn *conn)
 957 {
 958         struct iscsi_session *sess = conn->sess;
 959         struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
 960
 961         spin_lock_bh(&conn->nopin_timer_lock);
 962         if (!(conn->nopin_response_timer_flags & ISCSI_TF_RUNNING)) {
 963                 spin_unlock_bh(&conn->nopin_timer_lock);
 964                 return;
 965         }
 966
 967         mod_timer(&conn->nopin_response_timer,
 968                 (get_jiffies_64() + na->nopin_response_timeout * HZ));
 969         spin_unlock_bh(&conn->nopin_timer_lock);
 970 }
 971
 972 /*
 973  *      Called with conn->nopin_timer_lock held.
 974  */
 975 void iscsit_start_nopin_response_timer(struct iscsi_conn *conn)
 976 {
 977         struct iscsi_session *sess = conn->sess;
 978         struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
 979
 980         spin_lock_bh(&conn->nopin_timer_lock);
 981         if (conn->nopin_response_timer_flags & ISCSI_TF_RUNNING) {
 982                 spin_unlock_bh(&conn->nopin_timer_lock);
 983                 return;
 984         }
 985
 986         init_timer(&conn->nopin_response_timer);
 987         conn->nopin_response_timer.expires =
 988                 (get_jiffies_64() + na->nopin_response_timeout * HZ);
 989         conn->nopin_response_timer.data = (unsigned long)conn;
 990         conn->nopin_response_timer.function = iscsit_handle_nopin_response_timeout;
 991         conn->nopin_response_timer_flags &= ~ISCSI_TF_STOP;
 992         conn->nopin_response_timer_flags |= ISCSI_TF_RUNNING;
 993         add_timer(&conn->nopin_response_timer);
 994
 995         pr_debug("Started NOPIN Response Timer on CID: %d to %u"
 996                 " seconds\n", conn->cid, na->nopin_response_timeout);
 997         spin_unlock_bh(&conn->nopin_timer_lock);
 998 }
 999
1000 void iscsit_stop_nopin_response_timer(struct iscsi_conn *conn)
1001 {
1002         spin_lock_bh(&conn->nopin_timer_lock);
1003         if (!(conn->nopin_response_timer_flags & ISCSI_TF_RUNNING)) {
1004                 spin_unlock_bh(&conn->nopin_timer_lock);
1005                 return;
1006         }
1007         conn->nopin_response_timer_flags |= ISCSI_TF_STOP;
1008         spin_unlock_bh(&conn->nopin_timer_lock);
1009
1010         del_timer_sync(&conn->nopin_response_timer);
1011
1012         spin_lock_bh(&conn->nopin_timer_lock);
1013         conn->nopin_response_timer_flags &= ~ISCSI_TF_RUNNING;
1014         spin_unlock_bh(&conn->nopin_timer_lock);
1015 }
1016
1017 static void iscsit_handle_nopin_timeout(unsigned long data)
1018 {
1019         struct iscsi_conn *conn = (struct iscsi_conn *) data;
1020
1021         iscsit_inc_conn_usage_count(conn);
1022
1023         spin_lock_bh(&conn->nopin_timer_lock);
1024         if (conn->nopin_timer_flags & ISCSI_TF_STOP) {
1025                 spin_unlock_bh(&conn->nopin_timer_lock);
1026                 iscsit_dec_conn_usage_count(conn);
1027                 return;
1028         }
1029         conn->nopin_timer_flags &= ~ISCSI_TF_RUNNING;
1030         spin_unlock_bh(&conn->nopin_timer_lock);
1031
1032         iscsit_add_nopin(conn, 1);
1033         iscsit_dec_conn_usage_count(conn);
1034 }
1035
1036 /*
1037  * Called with conn->nopin_timer_lock held.
1038  */
1039 void __iscsit_start_nopin_timer(struct iscsi_conn *conn)
1040 {
1041         struct iscsi_session *sess = conn->sess;
1042         struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
1043         /*
1044         * NOPIN timeout is disabled.
1045          */
1046         if (!na->nopin_timeout)
1047                 return;
1048
1049         if (conn->nopin_timer_flags & ISCSI_TF_RUNNING)
1050                 return;
1051
1052         init_timer(&conn->nopin_timer);
1053         conn->nopin_timer.expires = (get_jiffies_64() + na->nopin_timeout * HZ);
1054         conn->nopin_timer.data = (unsigned long)conn;
1055         conn->nopin_timer.function = iscsit_handle_nopin_timeout;
1056         conn->nopin_timer_flags &= ~ISCSI_TF_STOP;
1057         conn->nopin_timer_flags |= ISCSI_TF_RUNNING;
1058         add_timer(&conn->nopin_timer);
1059
1060         pr_debug("Started NOPIN Timer on CID: %d at %u second"
1061                 " interval\n", conn->cid, na->nopin_timeout);
1062 }
1063
1064 void iscsit_start_nopin_timer(struct iscsi_conn *conn)
1065 {
1066         struct iscsi_session *sess = conn->sess;
1067         struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
1068         /*
1069          * NOPIN timeout is disabled..
1070          */
1071         if (!na->nopin_timeout)
1072                 return;
1073
1074         spin_lock_bh(&conn->nopin_timer_lock);
1075         if (conn->nopin_timer_flags & ISCSI_TF_RUNNING) {
1076                 spin_unlock_bh(&conn->nopin_timer_lock);
1077                 return;
1078         }
1079
1080         init_timer(&conn->nopin_timer);
1081         conn->nopin_timer.expires = (get_jiffies_64() + na->nopin_timeout * HZ);
1082         conn->nopin_timer.data = (unsigned long)conn;
1083         conn->nopin_timer.function = iscsit_handle_nopin_timeout;
1084         conn->nopin_timer_flags &= ~ISCSI_TF_STOP;
1085         conn->nopin_timer_flags |= ISCSI_TF_RUNNING;
1086         add_timer(&conn->nopin_timer);
1087
1088         pr_debug("Started NOPIN Timer on CID: %d at %u second"
1089                         " interval\n", conn->cid, na->nopin_timeout);
1090         spin_unlock_bh(&conn->nopin_timer_lock);
1091 }
1092
1093 void iscsit_stop_nopin_timer(struct iscsi_conn *conn)
1094 {
1095         spin_lock_bh(&conn->nopin_timer_lock);
1096         if (!(conn->nopin_timer_flags & ISCSI_TF_RUNNING)) {
1097                 spin_unlock_bh(&conn->nopin_timer_lock);
1098                 return;
1099         }
1100         conn->nopin_timer_flags |= ISCSI_TF_STOP;
1101         spin_unlock_bh(&conn->nopin_timer_lock);
1102
1103         del_timer_sync(&conn->nopin_timer);
1104
1105         spin_lock_bh(&conn->nopin_timer_lock);
1106         conn->nopin_timer_flags &= ~ISCSI_TF_RUNNING;
1107         spin_unlock_bh(&conn->nopin_timer_lock);
1108 }
1109
1110 int iscsit_send_tx_data(
1111         struct iscsi_cmd *cmd,
1112         struct iscsi_conn *conn,
1113         int use_misc)
1114 {
1115         int tx_sent, tx_size;
1116         u32 iov_count;
1117         struct kvec *iov;
1118
1119 send_data:
1120         tx_size = cmd->tx_size;
1121
1122         if (!use_misc) {
1123                 iov = &cmd->iov_data[0];
1124                 iov_count = cmd->iov_data_count;
1125         } else {
1126                 iov = &cmd->iov_misc[0];
1127                 iov_count = cmd->iov_misc_count;
1128         }
1129
1130         tx_sent = tx_data(conn, &iov[0], iov_count, tx_size);
1131         if (tx_size != tx_sent) {
1132                 if (tx_sent == -EAGAIN) {
1133                         pr_err("tx_data() returned -EAGAIN\n");
1134                         goto send_data;
1135                 } else
1136                         return -1;
1137         }
1138         cmd->tx_size = 0;
1139
1140         return 0;
1141 }
1142
1143 int iscsit_fe_sendpage_sg(
1144         struct iscsi_cmd *cmd,
1145         struct iscsi_conn *conn)
1146 {
1147         struct scatterlist *sg = cmd->first_data_sg;
1148         struct kvec iov;
1149         u32 tx_hdr_size, data_len;
1150         u32 offset = cmd->first_data_sg_off;
1151         int tx_sent, iov_off;
1152
1153 send_hdr:
1154         tx_hdr_size = ISCSI_HDR_LEN;
1155         if (conn->conn_ops->HeaderDigest)
1156                 tx_hdr_size += ISCSI_CRC_LEN;
1157
1158         iov.iov_base = cmd->pdu;
1159         iov.iov_len = tx_hdr_size;
1160
1161         tx_sent = tx_data(conn, &iov, 1, tx_hdr_size);
1162         if (tx_hdr_size != tx_sent) {
1163                 if (tx_sent == -EAGAIN) {
1164                         pr_err("tx_data() returned -EAGAIN\n");
1165                         goto send_hdr;
1166                 }
1167                 return -1;
1168         }
1169
1170         data_len = cmd->tx_size - tx_hdr_size - cmd->padding;
1171         /*
1172          * Set iov_off used by padding and data digest tx_data() calls below
1173          * in order to determine proper offset into cmd->iov_data[]
1174          */
1175         if (conn->conn_ops->DataDigest) {
1176                 data_len -= ISCSI_CRC_LEN;
1177                 if (cmd->padding)
1178                         iov_off = (cmd->iov_data_count - 2);
1179                 else
1180                         iov_off = (cmd->iov_data_count - 1);
1181         } else {
1182                 iov_off = (cmd->iov_data_count - 1);
1183         }
1184         /*
1185          * Perform sendpage() for each page in the scatterlist
1186          */
1187         while (data_len) {
1188                 u32 space = (sg->length - offset);
1189                 u32 sub_len = min_t(u32, data_len, space);
1190 send_pg:
1191                 tx_sent = conn->sock->ops->sendpage(conn->sock,
1192                                         sg_page(sg), sg->offset + offset, sub_len, 0);
1193                 if (tx_sent != sub_len) {
1194                         if (tx_sent == -EAGAIN) {
1195                                 pr_err("tcp_sendpage() returned"
1196                                                 " -EAGAIN\n");
1197                                 goto send_pg;
1198                         }
1199
1200                         pr_err("tcp_sendpage() failure: %d\n",
1201                                         tx_sent);
1202                         return -1;
1203                 }
1204
1205                 data_len -= sub_len;
1206                 offset = 0;
1207                 sg = sg_next(sg);
1208         }
1209
1210 send_padding:
1211         if (cmd->padding) {
1212                 struct kvec *iov_p = &cmd->iov_data[iov_off++];
1213
1214                 tx_sent = tx_data(conn, iov_p, 1, cmd->padding);
1215                 if (cmd->padding != tx_sent) {
1216                         if (tx_sent == -EAGAIN) {
1217                                 pr_err("tx_data() returned -EAGAIN\n");
1218                                 goto send_padding;
1219                         }
1220                         return -1;
1221                 }
1222         }
1223
1224 send_datacrc:
1225         if (conn->conn_ops->DataDigest) {
1226                 struct kvec *iov_d = &cmd->iov_data[iov_off];
1227
1228                 tx_sent = tx_data(conn, iov_d, 1, ISCSI_CRC_LEN);
1229                 if (ISCSI_CRC_LEN != tx_sent) {
1230                         if (tx_sent == -EAGAIN) {
1231                                 pr_err("tx_data() returned -EAGAIN\n");
1232                                 goto send_datacrc;
1233                         }
1234                         return -1;
1235                 }
1236         }
1237
1238         return 0;
1239 }
1240
1241 /*
1242  *      This function is used for mainly sending a ISCSI_TARG_LOGIN_RSP PDU
1243  *      back to the Initiator when an expection condition occurs with the
1244  *      errors set in status_class and status_detail.
1245  *
1246  *      Parameters:     iSCSI Connection, Status Class, Status Detail.
1247  *      Returns:        0 on success, -1 on error.
1248  */
1249 int iscsit_tx_login_rsp(struct iscsi_conn *conn, u8 status_class, u8 status_detail)
1250 {
1251         struct iscsi_login_rsp *hdr;
1252         struct iscsi_login *login = conn->conn_login;
1253
1254         login->login_failed = 1;
1255         iscsit_collect_login_stats(conn, status_class, status_detail);
1256
1257         memset(&login->rsp[0], 0, ISCSI_HDR_LEN);
1258
1259         hdr     = (struct iscsi_login_rsp *)&login->rsp[0];
1260         hdr->opcode             = ISCSI_OP_LOGIN_RSP;
1261         hdr->status_class       = status_class;
1262         hdr->status_detail      = status_detail;
1263         hdr->itt                = conn->login_itt;
1264
1265         return conn->conn_transport->iscsit_put_login_tx(conn, login, 0);
1266 }
1267
1268 void iscsit_print_session_params(struct iscsi_session *sess)
1269 {
1270         struct iscsi_conn *conn;
1271
1272         pr_debug("-----------------------------[Session Params for"
1273                 " SID: %u]-----------------------------\n", sess->sid);
1274         spin_lock_bh(&sess->conn_lock);
1275         list_for_each_entry(conn, &sess->sess_conn_list, conn_list)
1276                 iscsi_dump_conn_ops(conn->conn_ops);
1277         spin_unlock_bh(&sess->conn_lock);
1278
1279         iscsi_dump_sess_ops(sess->sess_ops);
1280 }
1281
1282 static int iscsit_do_rx_data(
1283         struct iscsi_conn *conn,
1284         struct iscsi_data_count *count)
1285 {
1286         int data = count->data_length, rx_loop = 0, total_rx = 0;
1287         struct msghdr msg;
1288
1289         if (!conn || !conn->sock || !conn->conn_ops)
1290                 return -1;
1291
1292         memset(&msg, 0, sizeof(struct msghdr));
1293         iov_iter_kvec(&msg.msg_iter, READ | ITER_KVEC,
1294                       count->iov, count->iov_count, data);
1295
1296         while (msg_data_left(&msg)) {
1297                 rx_loop = sock_recvmsg(conn->sock, &msg, MSG_WAITALL);
1298                 if (rx_loop <= 0) {
1299                         pr_debug("rx_loop: %d total_rx: %d\n",
1300                                 rx_loop, total_rx);
1301                         return rx_loop;
1302                 }
1303                 total_rx += rx_loop;
1304                 pr_debug("rx_loop: %d, total_rx: %d, data: %d\n",
1305                                 rx_loop, total_rx, data);
1306         }
1307
1308         return total_rx;
1309 }
1310
1311 int rx_data(
1312         struct iscsi_conn *conn,
1313         struct kvec *iov,
1314         int iov_count,
1315         int data)
1316 {
1317         struct iscsi_data_count c;
1318
1319         if (!conn || !conn->sock || !conn->conn_ops)
1320                 return -1;
1321
1322         memset(&c, 0, sizeof(struct iscsi_data_count));
1323         c.iov = iov;
1324         c.iov_count = iov_count;
1325         c.data_length = data;
1326         c.type = ISCSI_RX_DATA;
1327
1328         return iscsit_do_rx_data(conn, &c);
1329 }
1330
1331 int tx_data(
1332         struct iscsi_conn *conn,
1333         struct kvec *iov,
1334         int iov_count,
1335         int data)
1336 {
1337         struct msghdr msg;
1338         int total_tx = 0;
1339
1340         if (!conn || !conn->sock || !conn->conn_ops)
1341                 return -1;
1342
1343         if (data <= 0) {
1344                 pr_err("Data length is: %d\n", data);
1345                 return -1;
1346         }
1347
1348         memset(&msg, 0, sizeof(struct msghdr));
1349
1350         iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC,
1351                       iov, iov_count, data);
1352
1353         while (msg_data_left(&msg)) {
1354                 int tx_loop = sock_sendmsg(conn->sock, &msg);
1355                 if (tx_loop <= 0) {
1356                         pr_debug("tx_loop: %d total_tx %d\n",
1357                                 tx_loop, total_tx);
1358                         return tx_loop;
1359                 }
1360                 total_tx += tx_loop;
1361                 pr_debug("tx_loop: %d, total_tx: %d, data: %d\n",
1362                                         tx_loop, total_tx, data);
1363         }
1364
1365         return total_tx;
1366 }
1367
1368 void iscsit_collect_login_stats(
1369         struct iscsi_conn *conn,
1370         u8 status_class,
1371         u8 status_detail)
1372 {
1373         struct iscsi_param *intrname = NULL;
1374         struct iscsi_tiqn *tiqn;
1375         struct iscsi_login_stats *ls;
1376
1377         tiqn = iscsit_snmp_get_tiqn(conn);
1378         if (!tiqn)
1379                 return;
1380
1381         ls = &tiqn->login_stats;
1382
1383         spin_lock(&ls->lock);
1384         if (status_class == ISCSI_STATUS_CLS_SUCCESS)
1385                 ls->accepts++;
1386         else if (status_class == ISCSI_STATUS_CLS_REDIRECT) {
1387                 ls->redirects++;
1388                 ls->last_fail_type = ISCSI_LOGIN_FAIL_REDIRECT;
1389         } else if ((status_class == ISCSI_STATUS_CLS_INITIATOR_ERR)  &&
1390                  (status_detail == ISCSI_LOGIN_STATUS_AUTH_FAILED)) {
1391                 ls->authenticate_fails++;
1392                 ls->last_fail_type =  ISCSI_LOGIN_FAIL_AUTHENTICATE;
1393         } else if ((status_class == ISCSI_STATUS_CLS_INITIATOR_ERR)  &&
1394                  (status_detail == ISCSI_LOGIN_STATUS_TGT_FORBIDDEN)) {
1395                 ls->authorize_fails++;
1396                 ls->last_fail_type = ISCSI_LOGIN_FAIL_AUTHORIZE;
1397         } else if ((status_class == ISCSI_STATUS_CLS_INITIATOR_ERR) &&
1398                  (status_detail == ISCSI_LOGIN_STATUS_INIT_ERR)) {
1399                 ls->negotiate_fails++;
1400                 ls->last_fail_type = ISCSI_LOGIN_FAIL_NEGOTIATE;
1401         } else {
1402                 ls->other_fails++;
1403                 ls->last_fail_type = ISCSI_LOGIN_FAIL_OTHER;
1404         }
1405
1406         /* Save initiator name, ip address and time, if it is a failed login */
1407         if (status_class != ISCSI_STATUS_CLS_SUCCESS) {
1408                 if (conn->param_list)
1409                         intrname = iscsi_find_param_from_key(INITIATORNAME,
1410                                                              conn->param_list);
1411                 strlcpy(ls->last_intr_fail_name,
1412                        (intrname ? intrname->value : "Unknown"),
1413                        sizeof(ls->last_intr_fail_name));
1414
1415                 ls->last_intr_fail_ip_family = conn->login_family;
1416
1417                 ls->last_intr_fail_sockaddr = conn->login_sockaddr;
1418                 ls->last_fail_time = get_jiffies_64();
1419         }
1420
1421         spin_unlock(&ls->lock);
1422 }
1423
1424 struct iscsi_tiqn *iscsit_snmp_get_tiqn(struct iscsi_conn *conn)
1425 {
1426         struct iscsi_portal_group *tpg;
1427
1428         if (!conn)
1429                 return NULL;
1430
1431         tpg = conn->tpg;
1432         if (!tpg)
1433                 return NULL;
1434
1435         if (!tpg->tpg_tiqn)
1436                 return NULL;
1437
1438         return tpg->tpg_tiqn;
1439 }