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                         if (!(cmd->se_cmd.se_cmd_flags & SCF_SE_LUN_CMD))
 147                                 iscsit_release_cmd(cmd);
 148                         else
 149                                 transport_generic_free_cmd(&cmd->se_cmd, 1);
 150                         spin_lock(&cr->conn_recovery_cmd_lock);
 151                 }
 152                 spin_unlock(&cr->conn_recovery_cmd_lock);
 153                 spin_lock(&sess->cr_a_lock);
 154
 155                 kfree(cr);
 156         }
 157         spin_unlock(&sess->cr_a_lock);
 158
 159         spin_lock(&sess->cr_i_lock);
 160         list_for_each_entry_safe(cr, cr_tmp, &sess->cr_inactive_list, cr_list) {
 161                 list_del(&cr->cr_list);
 162                 spin_unlock(&sess->cr_i_lock);
 163
 164                 spin_lock(&cr->conn_recovery_cmd_lock);
 165                 list_for_each_entry_safe(cmd, cmd_tmp,
 166                                 &cr->conn_recovery_cmd_list, i_list) {
 167
 168                         list_del(&cmd->i_list);
 169                         cmd->conn = NULL;
 170                         spin_unlock(&cr->conn_recovery_cmd_lock);
 171                         if (!(cmd->se_cmd.se_cmd_flags & SCF_SE_LUN_CMD))
 172                                 iscsit_release_cmd(cmd);
 173                         else
 174                                 transport_generic_free_cmd(&cmd->se_cmd, 1);
 175                         spin_lock(&cr->conn_recovery_cmd_lock);
 176                 }
 177                 spin_unlock(&cr->conn_recovery_cmd_lock);
 178                 spin_lock(&sess->cr_i_lock);
 179
 180                 kfree(cr);
 181         }
 182         spin_unlock(&sess->cr_i_lock);
 183 }
 184
 185 int iscsit_remove_active_connection_recovery_entry(
 186         struct iscsi_conn_recovery *cr,
 187         struct iscsi_session *sess)
 188 {
 189         spin_lock(&sess->cr_a_lock);
 190         list_del(&cr->cr_list);
 191
 192         sess->conn_recovery_count--;
 193         pr_debug("Decremented connection recovery count to %u for"
 194                 " SID: %u\n", sess->conn_recovery_count, sess->sid);
 195         spin_unlock(&sess->cr_a_lock);
 196
 197         kfree(cr);
 198
 199         return 0;
 200 }
 201
 202 int iscsit_remove_inactive_connection_recovery_entry(
 203         struct iscsi_conn_recovery *cr,
 204         struct iscsi_session *sess)
 205 {
 206         spin_lock(&sess->cr_i_lock);
 207         list_del(&cr->cr_list);
 208         spin_unlock(&sess->cr_i_lock);
 209
 210         return 0;
 211 }
 212
 213 /*
 214  *      Called with cr->conn_recovery_cmd_lock help.
 215  */
 216 int iscsit_remove_cmd_from_connection_recovery(
 217         struct iscsi_cmd *cmd,
 218         struct iscsi_session *sess)
 219 {
 220         struct iscsi_conn_recovery *cr;
 221
 222         if (!cmd->cr) {
 223                 pr_err("struct iscsi_conn_recovery pointer for ITT: 0x%08x"
 224                         " is NULL!\n", cmd->init_task_tag);
 225                 BUG();
 226         }
 227         cr = cmd->cr;
 228
 229         list_del(&cmd->i_list);
 230         return --cr->cmd_count;
 231 }
 232
 233 void iscsit_discard_cr_cmds_by_expstatsn(
 234         struct iscsi_conn_recovery *cr,
 235         u32 exp_statsn)
 236 {
 237         u32 dropped_count = 0;
 238         struct iscsi_cmd *cmd, *cmd_tmp;
 239         struct iscsi_session *sess = cr->sess;
 240
 241         spin_lock(&cr->conn_recovery_cmd_lock);
 242         list_for_each_entry_safe(cmd, cmd_tmp,
 243                         &cr->conn_recovery_cmd_list, i_list) {
 244
 245                 if (((cmd->deferred_i_state != ISTATE_SENT_STATUS) &&
 246                      (cmd->deferred_i_state != ISTATE_REMOVE)) ||
 247                      (cmd->stat_sn >= exp_statsn)) {
 248                         continue;
 249                 }
 250
 251                 dropped_count++;
 252                 pr_debug("Dropping Acknowledged ITT: 0x%08x, StatSN:"
 253                         " 0x%08x, CID: %hu.\n", cmd->init_task_tag,
 254                                 cmd->stat_sn, cr->cid);
 255
 256                 iscsit_remove_cmd_from_connection_recovery(cmd, sess);
 257
 258                 spin_unlock(&cr->conn_recovery_cmd_lock);
 259                 if (!(cmd->se_cmd.se_cmd_flags & SCF_SE_LUN_CMD))
 260                         iscsit_release_cmd(cmd);
 261                 else
 262                         transport_generic_free_cmd(&cmd->se_cmd, 1);
 263                 spin_lock(&cr->conn_recovery_cmd_lock);
 264         }
 265         spin_unlock(&cr->conn_recovery_cmd_lock);
 266
 267         pr_debug("Dropped %u total acknowledged commands on"
 268                 " CID: %hu less than old ExpStatSN: 0x%08x\n",
 269                         dropped_count, cr->cid, exp_statsn);
 270
 271         if (!cr->cmd_count) {
 272                 pr_debug("No commands to be reassigned for failed"
 273                         " connection CID: %hu on SID: %u\n",
 274                         cr->cid, sess->sid);
 275                 iscsit_remove_inactive_connection_recovery_entry(cr, sess);
 276                 iscsit_attach_active_connection_recovery_entry(sess, cr);
 277                 pr_debug("iSCSI connection recovery successful for CID:"
 278                         " %hu on SID: %u\n", cr->cid, sess->sid);
 279                 iscsit_remove_active_connection_recovery_entry(cr, sess);
 280         } else {
 281                 iscsit_remove_inactive_connection_recovery_entry(cr, sess);
 282                 iscsit_attach_active_connection_recovery_entry(sess, cr);
 283         }
 284 }
 285
 286 int iscsit_discard_unacknowledged_ooo_cmdsns_for_conn(struct iscsi_conn *conn)
 287 {
 288         u32 dropped_count = 0;
 289         struct iscsi_cmd *cmd, *cmd_tmp;
 290         struct iscsi_ooo_cmdsn *ooo_cmdsn, *ooo_cmdsn_tmp;
 291         struct iscsi_session *sess = conn->sess;
 292
 293         mutex_lock(&sess->cmdsn_mutex);
 294         list_for_each_entry_safe(ooo_cmdsn, ooo_cmdsn_tmp,
 295                         &sess->sess_ooo_cmdsn_list, ooo_list) {
 296
 297                 if (ooo_cmdsn->cid != conn->cid)
 298                         continue;
 299
 300                 dropped_count++;
 301                 pr_debug("Dropping unacknowledged CmdSN:"
 302                 " 0x%08x during connection recovery on CID: %hu\n",
 303                         ooo_cmdsn->cmdsn, conn->cid);
 304                 iscsit_remove_ooo_cmdsn(sess, ooo_cmdsn);
 305         }
 306         mutex_unlock(&sess->cmdsn_mutex);
 307
 308         spin_lock_bh(&conn->cmd_lock);
 309         list_for_each_entry_safe(cmd, cmd_tmp, &conn->conn_cmd_list, i_list) {
 310                 if (!(cmd->cmd_flags & ICF_OOO_CMDSN))
 311                         continue;
 312
 313                 list_del(&cmd->i_list);
 314
 315                 spin_unlock_bh(&conn->cmd_lock);
 316                 if (!(cmd->se_cmd.se_cmd_flags & SCF_SE_LUN_CMD))
 317                         iscsit_release_cmd(cmd);
 318                 else
 319                         transport_generic_free_cmd(&cmd->se_cmd, 1);
 320                 spin_lock_bh(&conn->cmd_lock);
 321         }
 322         spin_unlock_bh(&conn->cmd_lock);
 323
 324         pr_debug("Dropped %u total unacknowledged commands on CID:"
 325                 " %hu for ExpCmdSN: 0x%08x.\n", dropped_count, conn->cid,
 326                                 sess->exp_cmd_sn);
 327         return 0;
 328 }
 329
 330 int iscsit_prepare_cmds_for_realligance(struct iscsi_conn *conn)
 331 {
 332         u32 cmd_count = 0;
 333         struct iscsi_cmd *cmd, *cmd_tmp;
 334         struct iscsi_conn_recovery *cr;
 335
 336         /*
 337          * Allocate an struct iscsi_conn_recovery for this connection.
 338          * Each struct iscsi_cmd contains an struct iscsi_conn_recovery pointer
 339          * (struct iscsi_cmd->cr) so we need to allocate this before preparing the
 340          * connection's command list for connection recovery.
 341          */
 342         cr = kzalloc(sizeof(struct iscsi_conn_recovery), GFP_KERNEL);
 343         if (!cr) {
 344                 pr_err("Unable to allocate memory for"
 345                         " struct iscsi_conn_recovery.\n");
 346                 return -1;
 347         }
 348         INIT_LIST_HEAD(&cr->cr_list);
 349         INIT_LIST_HEAD(&cr->conn_recovery_cmd_list);
 350         spin_lock_init(&cr->conn_recovery_cmd_lock);
 351         /*
 352          * Only perform connection recovery on ISCSI_OP_SCSI_CMD or
 353          * ISCSI_OP_NOOP_OUT opcodes.  For all other opcodes call
 354          * list_del(&cmd->i_list); to release the command to the
 355          * session pool and remove it from the connection's list.
 356          *
 357          * Also stop the DataOUT timer, which will be restarted after
 358          * sending the TMR response.
 359          */
 360         spin_lock_bh(&conn->cmd_lock);
 361         list_for_each_entry_safe(cmd, cmd_tmp, &conn->conn_cmd_list, i_list) {
 362
 363                 if ((cmd->iscsi_opcode != ISCSI_OP_SCSI_CMD) &&
 364                     (cmd->iscsi_opcode != ISCSI_OP_NOOP_OUT)) {
 365                         pr_debug("Not performing realligence on"
 366                                 " Opcode: 0x%02x, ITT: 0x%08x, CmdSN: 0x%08x,"
 367                                 " CID: %hu\n", cmd->iscsi_opcode,
 368                                 cmd->init_task_tag, cmd->cmd_sn, conn->cid);
 369
 370                         list_del(&cmd->i_list);
 371                         spin_unlock_bh(&conn->cmd_lock);
 372
 373                         if (!(cmd->se_cmd.se_cmd_flags & SCF_SE_LUN_CMD))
 374                                 iscsit_release_cmd(cmd);
 375                         else
 376                                 transport_generic_free_cmd(&cmd->se_cmd, 1);
 377                         spin_lock_bh(&conn->cmd_lock);
 378                         continue;
 379                 }
 380
 381                 /*
 382                  * Special case where commands greater than or equal to
 383                  * the session's ExpCmdSN are attached to the connection
 384                  * list but not to the out of order CmdSN list.  The one
 385                  * obvious case is when a command with immediate data
 386                  * attached must only check the CmdSN against ExpCmdSN
 387                  * after the data is received.  The special case below
 388                  * is when the connection fails before data is received,
 389                  * but also may apply to other PDUs, so it has been
 390                  * made generic here.
 391                  */
 392                 if (!(cmd->cmd_flags & ICF_OOO_CMDSN) && !cmd->immediate_cmd &&
 393                      (cmd->cmd_sn >= conn->sess->exp_cmd_sn)) {
 394                         list_del(&cmd->i_list);
 395                         spin_unlock_bh(&conn->cmd_lock);
 396
 397                         if (!(cmd->se_cmd.se_cmd_flags & SCF_SE_LUN_CMD))
 398                                 iscsit_release_cmd(cmd);
 399                         else
 400                                 transport_generic_free_cmd(&cmd->se_cmd, 1);
 401                         spin_lock_bh(&conn->cmd_lock);
 402                         continue;
 403                 }
 404
 405                 cmd_count++;
 406                 pr_debug("Preparing Opcode: 0x%02x, ITT: 0x%08x,"
 407                         " CmdSN: 0x%08x, StatSN: 0x%08x, CID: %hu for"
 408                         " realligence.\n", cmd->iscsi_opcode,
 409                         cmd->init_task_tag, cmd->cmd_sn, cmd->stat_sn,
 410                         conn->cid);
 411
 412                 cmd->deferred_i_state = cmd->i_state;
 413                 cmd->i_state = ISTATE_IN_CONNECTION_RECOVERY;
 414
 415                 if (cmd->data_direction == DMA_TO_DEVICE)
 416                         iscsit_stop_dataout_timer(cmd);
 417
 418                 cmd->sess = conn->sess;
 419
 420                 list_del(&cmd->i_list);
 421                 spin_unlock_bh(&conn->cmd_lock);
 422
 423                 iscsit_free_all_datain_reqs(cmd);
 424
 425                 if (cmd->se_cmd.se_cmd_flags & SCF_SE_LUN_CMD)
 426                         transport_wait_for_tasks(&cmd->se_cmd);
 427                 /*
 428                  * Add the struct iscsi_cmd to the connection recovery cmd list
 429                  */
 430                 spin_lock(&cr->conn_recovery_cmd_lock);
 431                 list_add_tail(&cmd->i_list, &cr->conn_recovery_cmd_list);
 432                 spin_unlock(&cr->conn_recovery_cmd_lock);
 433
 434                 spin_lock_bh(&conn->cmd_lock);
 435                 cmd->cr = cr;
 436                 cmd->conn = NULL;
 437         }
 438         spin_unlock_bh(&conn->cmd_lock);
 439         /*
 440          * Fill in the various values in the preallocated struct iscsi_conn_recovery.
 441          */
 442         cr->cid = conn->cid;
 443         cr->cmd_count = cmd_count;
 444         cr->maxrecvdatasegmentlength = conn->conn_ops->MaxRecvDataSegmentLength;
 445         cr->sess = conn->sess;
 446
 447         iscsit_attach_inactive_connection_recovery_entry(conn->sess, cr);
 448
 449         return 0;
 450 }
 451
 452 int iscsit_connection_recovery_transport_reset(struct iscsi_conn *conn)
 453 {
 454         atomic_set(&conn->connection_recovery, 1);
 455
 456         if (iscsit_close_connection(conn) < 0)
 457                 return -1;
 458
 459         return 0;
 460 }