drivers/target/iscsi/iscsi_target_erl2.c

   1 /*******************************************************************************
   2  * This file contains error recovery level two functions used by
   3  * the iSCSI Target driver.
   4  *
   5  * \u00a9 Copyright 2007-2011 RisingTide Systems LLC.
   6  *
   7  * Licensed to the Linux Foundation under the General Public License (GPL) version 2.
   8  *
   9  * Author: Nicholas A. Bellinger <nab@linux-iscsi.org>
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation; either version 2 of the License, or
  14  * (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  ******************************************************************************/
  21
  22 #include <scsi/iscsi_proto.h>
  23 #include <target/target_core_base.h>
  24 #include <target/target_core_transport.h>
  25
  26 #include "iscsi_target_core.h"
  27 #include "iscsi_target_datain_values.h"
  28 #include "iscsi_target_util.h"
  29 #include "iscsi_target_erl0.h"
  30 #include "iscsi_target_erl1.h"
  31 #include "iscsi_target_erl2.h"
  32 #include "iscsi_target.h"
  33
  34 /*
  35  *      FIXME: Does RData SNACK apply here as well?
  36  */
  37 void iscsit_create_conn_recovery_datain_values(
  38         struct iscsi_cmd *cmd,
  39         u32 exp_data_sn)
  40 {
  41         u32 data_sn = 0;
  42         struct iscsi_conn *conn = cmd->conn;
  43
  44         cmd->next_burst_len = 0;
  45         cmd->read_data_done = 0;
  46
  47         while (exp_data_sn > data_sn) {
  48                 if ((cmd->next_burst_len +
  49                      conn->conn_ops->MaxRecvDataSegmentLength) <
  50                      conn->sess->sess_ops->MaxBurstLength) {
  51                         cmd->read_data_done +=
  52                                conn->conn_ops->MaxRecvDataSegmentLength;
  53                         cmd->next_burst_len +=
  54                                conn->conn_ops->MaxRecvDataSegmentLength;
  55                 } else {
  56                         cmd->read_data_done +=
  57                                 (conn->sess->sess_ops->MaxBurstLength -
  58                                 cmd->next_burst_len);
  59                         cmd->next_burst_len = 0;
  60                 }
  61                 data_sn++;
  62         }
  63 }
  64
  65 void iscsit_create_conn_recovery_dataout_values(
  66         struct iscsi_cmd *cmd)
  67 {
  68         u32 write_data_done = 0;
  69         struct iscsi_conn *conn = cmd->conn;
  70
  71         cmd->data_sn = 0;
  72         cmd->next_burst_len = 0;
  73
  74         while (cmd->write_data_done > write_data_done) {
  75                 if ((write_data_done + conn->sess->sess_ops->MaxBurstLength) <=
  76                      cmd->write_data_done)
  77                         write_data_done += conn->sess->sess_ops->MaxBurstLength;
  78                 else
  79                         break;
  80         }
  81
  82         cmd->write_data_done = write_data_done;
  83 }
  84
  85 static int iscsit_attach_active_connection_recovery_entry(
  86         struct iscsi_session *sess,
  87         struct iscsi_conn_recovery *cr)
  88 {
  89         spin_lock(&sess->cr_a_lock);
  90         list_add_tail(&cr->cr_list, &sess->cr_active_list);
  91         spin_unlock(&sess->cr_a_lock);
  92
  93         return 0;
  94 }
  95
  96 static int iscsit_attach_inactive_connection_recovery_entry(
  97         struct iscsi_session *sess,
  98         struct iscsi_conn_recovery *cr)
  99 {
 100         spin_lock(&sess->cr_i_lock);
 101         list_add_tail(&cr->cr_list, &sess->cr_inactive_list);
 102
 103         sess->conn_recovery_count++;
 104         pr_debug("Incremented connection recovery count to %u for"
 105                 " SID: %u\n", sess->conn_recovery_count, sess->sid);
 106         spin_unlock(&sess->cr_i_lock);
 107
 108         return 0;
 109 }
 110
 111 struct iscsi_conn_recovery *iscsit_get_inactive_connection_recovery_entry(
 112         struct iscsi_session *sess,
 113         u16 cid)
 114 {
 115         struct iscsi_conn_recovery *cr;
 116
 117         spin_lock(&sess->cr_i_lock);
 118         list_for_each_entry(cr, &sess->cr_inactive_list, cr_list) {
 119                 if (cr->cid == cid) {
 120                         spin_unlock(&sess->cr_i_lock);
 121                         return cr;
 122                 }
 123         }
 124         spin_unlock(&sess->cr_i_lock);
 125
 126         return NULL;
 127 }
 128
 129 void iscsit_free_connection_recovery_entires(struct iscsi_session *sess)
 130 {
 131         struct iscsi_cmd *cmd, *cmd_tmp;
 132         struct iscsi_conn_recovery *cr, *cr_tmp;
 133
 134         spin_lock(&sess->cr_a_lock);
 135         list_for_each_entry_safe(cr, cr_tmp, &sess->cr_active_list, cr_list) {
 136                 list_del(&cr->cr_list);
 137                 spin_unlock(&sess->cr_a_lock);
 138
 139                 spin_lock(&cr->conn_recovery_cmd_lock);
 140                 list_for_each_entry_safe(cmd, cmd_tmp,
 141                                 &cr->conn_recovery_cmd_list, i_list) {
 142
 143                         list_del(&cmd->i_list);
 144                         cmd->conn = NULL;
 145                         spin_unlock(&cr->conn_recovery_cmd_lock);
 146                         iscsit_free_cmd(cmd);
 147                         spin_lock(&cr->conn_recovery_cmd_lock);
 148                 }
 149                 spin_unlock(&cr->conn_recovery_cmd_lock);
 150                 spin_lock(&sess->cr_a_lock);
 151
 152                 kfree(cr);
 153         }
 154         spin_unlock(&sess->cr_a_lock);
 155
 156         spin_lock(&sess->cr_i_lock);
 157         list_for_each_entry_safe(cr, cr_tmp, &sess->cr_inactive_list, cr_list) {
 158                 list_del(&cr->cr_list);
 159                 spin_unlock(&sess->cr_i_lock);
 160
 161                 spin_lock(&cr->conn_recovery_cmd_lock);
 162                 list_for_each_entry_safe(cmd, cmd_tmp,
 163                                 &cr->conn_recovery_cmd_list, i_list) {
 164
 165                         list_del(&cmd->i_list);
 166                         cmd->conn = NULL;
 167                         spin_unlock(&cr->conn_recovery_cmd_lock);
 168                         iscsit_free_cmd(cmd);
 169                         spin_lock(&cr->conn_recovery_cmd_lock);
 170                 }
 171                 spin_unlock(&cr->conn_recovery_cmd_lock);
 172                 spin_lock(&sess->cr_i_lock);
 173
 174                 kfree(cr);
 175         }
 176         spin_unlock(&sess->cr_i_lock);
 177 }
 178
 179 int iscsit_remove_active_connection_recovery_entry(
 180         struct iscsi_conn_recovery *cr,
 181         struct iscsi_session *sess)
 182 {
 183         spin_lock(&sess->cr_a_lock);
 184         list_del(&cr->cr_list);
 185
 186         sess->conn_recovery_count--;
 187         pr_debug("Decremented connection recovery count to %u for"
 188                 " SID: %u\n", sess->conn_recovery_count, sess->sid);
 189         spin_unlock(&sess->cr_a_lock);
 190
 191         kfree(cr);
 192
 193         return 0;
 194 }
 195
 196 int iscsit_remove_inactive_connection_recovery_entry(
 197         struct iscsi_conn_recovery *cr,
 198         struct iscsi_session *sess)
 199 {
 200         spin_lock(&sess->cr_i_lock);
 201         list_del(&cr->cr_list);
 202         spin_unlock(&sess->cr_i_lock);
 203
 204         return 0;
 205 }
 206
 207 /*
 208  *      Called with cr->conn_recovery_cmd_lock help.
 209  */
 210 int iscsit_remove_cmd_from_connection_recovery(
 211         struct iscsi_cmd *cmd,
 212         struct iscsi_session *sess)
 213 {
 214         struct iscsi_conn_recovery *cr;
 215
 216         if (!cmd->cr) {
 217                 pr_err("struct iscsi_conn_recovery pointer for ITT: 0x%08x"
 218                         " is NULL!\n", cmd->init_task_tag);
 219                 BUG();
 220         }
 221         cr = cmd->cr;
 222
 223         list_del(&cmd->i_list);
 224         return --cr->cmd_count;
 225 }
 226
 227 void iscsit_discard_cr_cmds_by_expstatsn(
 228         struct iscsi_conn_recovery *cr,
 229         u32 exp_statsn)
 230 {
 231         u32 dropped_count = 0;
 232         struct iscsi_cmd *cmd, *cmd_tmp;
 233         struct iscsi_session *sess = cr->sess;
 234
 235         spin_lock(&cr->conn_recovery_cmd_lock);
 236         list_for_each_entry_safe(cmd, cmd_tmp,
 237                         &cr->conn_recovery_cmd_list, i_list) {
 238
 239                 if (((cmd->deferred_i_state != ISTATE_SENT_STATUS) &&
 240                      (cmd->deferred_i_state != ISTATE_REMOVE)) ||
 241                      (cmd->stat_sn >= exp_statsn)) {
 242                         continue;
 243                 }
 244
 245                 dropped_count++;
 246                 pr_debug("Dropping Acknowledged ITT: 0x%08x, StatSN:"
 247                         " 0x%08x, CID: %hu.\n", cmd->init_task_tag,
 248                                 cmd->stat_sn, cr->cid);
 249
 250                 iscsit_remove_cmd_from_connection_recovery(cmd, sess);
 251
 252                 spin_unlock(&cr->conn_recovery_cmd_lock);
 253                 iscsit_free_cmd(cmd);
 254                 spin_lock(&cr->conn_recovery_cmd_lock);
 255         }
 256         spin_unlock(&cr->conn_recovery_cmd_lock);
 257
 258         pr_debug("Dropped %u total acknowledged commands on"
 259                 " CID: %hu less than old ExpStatSN: 0x%08x\n",
 260                         dropped_count, cr->cid, exp_statsn);
 261
 262         if (!cr->cmd_count) {
 263                 pr_debug("No commands to be reassigned for failed"
 264                         " connection CID: %hu on SID: %u\n",
 265                         cr->cid, sess->sid);
 266                 iscsit_remove_inactive_connection_recovery_entry(cr, sess);
 267                 iscsit_attach_active_connection_recovery_entry(sess, cr);
 268                 pr_debug("iSCSI connection recovery successful for CID:"
 269                         " %hu on SID: %u\n", cr->cid, sess->sid);
 270                 iscsit_remove_active_connection_recovery_entry(cr, sess);
 271         } else {
 272                 iscsit_remove_inactive_connection_recovery_entry(cr, sess);
 273                 iscsit_attach_active_connection_recovery_entry(sess, cr);
 274         }
 275 }
 276
 277 int iscsit_discard_unacknowledged_ooo_cmdsns_for_conn(struct iscsi_conn *conn)
 278 {
 279         u32 dropped_count = 0;
 280         struct iscsi_cmd *cmd, *cmd_tmp;
 281         struct iscsi_ooo_cmdsn *ooo_cmdsn, *ooo_cmdsn_tmp;
 282         struct iscsi_session *sess = conn->sess;
 283
 284         mutex_lock(&sess->cmdsn_mutex);
 285         list_for_each_entry_safe(ooo_cmdsn, ooo_cmdsn_tmp,
 286                         &sess->sess_ooo_cmdsn_list, ooo_list) {
 287
 288                 if (ooo_cmdsn->cid != conn->cid)
 289                         continue;
 290
 291                 dropped_count++;
 292                 pr_debug("Dropping unacknowledged CmdSN:"
 293                 " 0x%08x during connection recovery on CID: %hu\n",
 294                         ooo_cmdsn->cmdsn, conn->cid);
 295                 iscsit_remove_ooo_cmdsn(sess, ooo_cmdsn);
 296         }
 297         mutex_unlock(&sess->cmdsn_mutex);
 298
 299         spin_lock_bh(&conn->cmd_lock);
 300         list_for_each_entry_safe(cmd, cmd_tmp, &conn->conn_cmd_list, i_list) {
 301                 if (!(cmd->cmd_flags & ICF_OOO_CMDSN))
 302                         continue;
 303
 304                 list_del(&cmd->i_list);
 305
 306                 spin_unlock_bh(&conn->cmd_lock);
 307                 iscsit_free_cmd(cmd);
 308                 spin_lock_bh(&conn->cmd_lock);
 309         }
 310         spin_unlock_bh(&conn->cmd_lock);
 311
 312         pr_debug("Dropped %u total unacknowledged commands on CID:"
 313                 " %hu for ExpCmdSN: 0x%08x.\n", dropped_count, conn->cid,
 314                                 sess->exp_cmd_sn);
 315         return 0;
 316 }
 317
 318 int iscsit_prepare_cmds_for_realligance(struct iscsi_conn *conn)
 319 {
 320         u32 cmd_count = 0;
 321         struct iscsi_cmd *cmd, *cmd_tmp;
 322         struct iscsi_conn_recovery *cr;
 323
 324         /*
 325          * Allocate an struct iscsi_conn_recovery for this connection.
 326          * Each struct iscsi_cmd contains an struct iscsi_conn_recovery pointer
 327          * (struct iscsi_cmd->cr) so we need to allocate this before preparing the
 328          * connection's command list for connection recovery.
 329          */
 330         cr = kzalloc(sizeof(struct iscsi_conn_recovery), GFP_KERNEL);
 331         if (!cr) {
 332                 pr_err("Unable to allocate memory for"
 333                         " struct iscsi_conn_recovery.\n");
 334                 return -1;
 335         }
 336         INIT_LIST_HEAD(&cr->cr_list);
 337         INIT_LIST_HEAD(&cr->conn_recovery_cmd_list);
 338         spin_lock_init(&cr->conn_recovery_cmd_lock);
 339         /*
 340          * Only perform connection recovery on ISCSI_OP_SCSI_CMD or
 341          * ISCSI_OP_NOOP_OUT opcodes.  For all other opcodes call
 342          * list_del(&cmd->i_list); to release the command to the
 343          * session pool and remove it from the connection's list.
 344          *
 345          * Also stop the DataOUT timer, which will be restarted after
 346          * sending the TMR response.
 347          */
 348         spin_lock_bh(&conn->cmd_lock);
 349         list_for_each_entry_safe(cmd, cmd_tmp, &conn->conn_cmd_list, i_list) {
 350
 351                 if ((cmd->iscsi_opcode != ISCSI_OP_SCSI_CMD) &&
 352                     (cmd->iscsi_opcode != ISCSI_OP_NOOP_OUT)) {
 353                         pr_debug("Not performing realligence on"
 354                                 " Opcode: 0x%02x, ITT: 0x%08x, CmdSN: 0x%08x,"
 355                                 " CID: %hu\n", cmd->iscsi_opcode,
 356                                 cmd->init_task_tag, cmd->cmd_sn, conn->cid);
 357
 358                         list_del(&cmd->i_list);
 359                         spin_unlock_bh(&conn->cmd_lock);
 360                         iscsit_free_cmd(cmd);
 361                         spin_lock_bh(&conn->cmd_lock);
 362                         continue;
 363                 }
 364
 365                 /*
 366                  * Special case where commands greater than or equal to
 367                  * the session's ExpCmdSN are attached to the connection
 368                  * list but not to the out of order CmdSN list.  The one
 369                  * obvious case is when a command with immediate data
 370                  * attached must only check the CmdSN against ExpCmdSN
 371                  * after the data is received.  The special case below
 372                  * is when the connection fails before data is received,
 373                  * but also may apply to other PDUs, so it has been
 374                  * made generic here.
 375                  */
 376                 if (!(cmd->cmd_flags & ICF_OOO_CMDSN) && !cmd->immediate_cmd &&
 377                      (cmd->cmd_sn >= conn->sess->exp_cmd_sn)) {
 378                         list_del(&cmd->i_list);
 379                         spin_unlock_bh(&conn->cmd_lock);
 380                         iscsit_free_cmd(cmd);
 381                         spin_lock_bh(&conn->cmd_lock);
 382                         continue;
 383                 }
 384
 385                 cmd_count++;
 386                 pr_debug("Preparing Opcode: 0x%02x, ITT: 0x%08x,"
 387                         " CmdSN: 0x%08x, StatSN: 0x%08x, CID: %hu for"
 388                         " realligence.\n", cmd->iscsi_opcode,
 389                         cmd->init_task_tag, cmd->cmd_sn, cmd->stat_sn,
 390                         conn->cid);
 391
 392                 cmd->deferred_i_state = cmd->i_state;
 393                 cmd->i_state = ISTATE_IN_CONNECTION_RECOVERY;
 394
 395                 if (cmd->data_direction == DMA_TO_DEVICE)
 396                         iscsit_stop_dataout_timer(cmd);
 397
 398                 cmd->sess = conn->sess;
 399
 400                 list_del(&cmd->i_list);
 401                 spin_unlock_bh(&conn->cmd_lock);
 402
 403                 iscsit_free_all_datain_reqs(cmd);
 404
 405                 transport_wait_for_tasks(&cmd->se_cmd);
 406                 /*
 407                  * Add the struct iscsi_cmd to the connection recovery cmd list
 408                  */
 409                 spin_lock(&cr->conn_recovery_cmd_lock);
 410                 list_add_tail(&cmd->i_list, &cr->conn_recovery_cmd_list);
 411                 spin_unlock(&cr->conn_recovery_cmd_lock);
 412
 413                 spin_lock_bh(&conn->cmd_lock);
 414                 cmd->cr = cr;
 415                 cmd->conn = NULL;
 416         }
 417         spin_unlock_bh(&conn->cmd_lock);
 418         /*
 419          * Fill in the various values in the preallocated struct iscsi_conn_recovery.
 420          */
 421         cr->cid = conn->cid;
 422         cr->cmd_count = cmd_count;
 423         cr->maxrecvdatasegmentlength = conn->conn_ops->MaxRecvDataSegmentLength;
 424         cr->sess = conn->sess;
 425
 426         iscsit_attach_inactive_connection_recovery_entry(conn->sess, cr);
 427
 428         return 0;
 429 }
 430
 431 int iscsit_connection_recovery_transport_reset(struct iscsi_conn *conn)
 432 {
 433         atomic_set(&conn->connection_recovery, 1);
 434
 435         if (iscsit_close_connection(conn) < 0)
 436                 return -1;
 437
 438         return 0;
 439 }