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_fabric.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         __be32 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 (be32_to_cpu(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_conn_node) {
 142
 143                         list_del(&cmd->i_conn_node);
 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_conn_node) {
 164
 165                         list_del(&cmd->i_conn_node);
 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 static void 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
 205 /*
 206  *      Called with cr->conn_recovery_cmd_lock help.
 207  */
 208 int iscsit_remove_cmd_from_connection_recovery(
 209         struct iscsi_cmd *cmd,
 210         struct iscsi_session *sess)
 211 {
 212         struct iscsi_conn_recovery *cr;
 213
 214         if (!cmd->cr) {
 215                 pr_err("struct iscsi_conn_recovery pointer for ITT: 0x%08x"
 216                         " is NULL!\n", cmd->init_task_tag);
 217                 BUG();
 218         }
 219         cr = cmd->cr;
 220
 221         list_del(&cmd->i_conn_node);
 222         return --cr->cmd_count;
 223 }
 224
 225 void iscsit_discard_cr_cmds_by_expstatsn(
 226         struct iscsi_conn_recovery *cr,
 227         u32 exp_statsn)
 228 {
 229         u32 dropped_count = 0;
 230         struct iscsi_cmd *cmd, *cmd_tmp;
 231         struct iscsi_session *sess = cr->sess;
 232
 233         spin_lock(&cr->conn_recovery_cmd_lock);
 234         list_for_each_entry_safe(cmd, cmd_tmp,
 235                         &cr->conn_recovery_cmd_list, i_conn_node) {
 236
 237                 if (((cmd->deferred_i_state != ISTATE_SENT_STATUS) &&
 238                      (cmd->deferred_i_state != ISTATE_REMOVE)) ||
 239                      (cmd->stat_sn >= exp_statsn)) {
 240                         continue;
 241                 }
 242
 243                 dropped_count++;
 244                 pr_debug("Dropping Acknowledged ITT: 0x%08x, StatSN:"
 245                         " 0x%08x, CID: %hu.\n", cmd->init_task_tag,
 246                                 cmd->stat_sn, cr->cid);
 247
 248                 iscsit_remove_cmd_from_connection_recovery(cmd, sess);
 249
 250                 spin_unlock(&cr->conn_recovery_cmd_lock);
 251                 iscsit_free_cmd(cmd);
 252                 spin_lock(&cr->conn_recovery_cmd_lock);
 253         }
 254         spin_unlock(&cr->conn_recovery_cmd_lock);
 255
 256         pr_debug("Dropped %u total acknowledged commands on"
 257                 " CID: %hu less than old ExpStatSN: 0x%08x\n",
 258                         dropped_count, cr->cid, exp_statsn);
 259
 260         if (!cr->cmd_count) {
 261                 pr_debug("No commands to be reassigned for failed"
 262                         " connection CID: %hu on SID: %u\n",
 263                         cr->cid, sess->sid);
 264                 iscsit_remove_inactive_connection_recovery_entry(cr, sess);
 265                 iscsit_attach_active_connection_recovery_entry(sess, cr);
 266                 pr_debug("iSCSI connection recovery successful for CID:"
 267                         " %hu on SID: %u\n", cr->cid, sess->sid);
 268                 iscsit_remove_active_connection_recovery_entry(cr, sess);
 269         } else {
 270                 iscsit_remove_inactive_connection_recovery_entry(cr, sess);
 271                 iscsit_attach_active_connection_recovery_entry(sess, cr);
 272         }
 273 }
 274
 275 int iscsit_discard_unacknowledged_ooo_cmdsns_for_conn(struct iscsi_conn *conn)
 276 {
 277         u32 dropped_count = 0;
 278         struct iscsi_cmd *cmd, *cmd_tmp;
 279         struct iscsi_ooo_cmdsn *ooo_cmdsn, *ooo_cmdsn_tmp;
 280         struct iscsi_session *sess = conn->sess;
 281
 282         mutex_lock(&sess->cmdsn_mutex);
 283         list_for_each_entry_safe(ooo_cmdsn, ooo_cmdsn_tmp,
 284                         &sess->sess_ooo_cmdsn_list, ooo_list) {
 285
 286                 if (ooo_cmdsn->cid != conn->cid)
 287                         continue;
 288
 289                 dropped_count++;
 290                 pr_debug("Dropping unacknowledged CmdSN:"
 291                 " 0x%08x during connection recovery on CID: %hu\n",
 292                         ooo_cmdsn->cmdsn, conn->cid);
 293                 iscsit_remove_ooo_cmdsn(sess, ooo_cmdsn);
 294         }
 295         mutex_unlock(&sess->cmdsn_mutex);
 296
 297         spin_lock_bh(&conn->cmd_lock);
 298         list_for_each_entry_safe(cmd, cmd_tmp, &conn->conn_cmd_list, i_conn_node) {
 299                 if (!(cmd->cmd_flags & ICF_OOO_CMDSN))
 300                         continue;
 301
 302                 list_del(&cmd->i_conn_node);
 303
 304                 spin_unlock_bh(&conn->cmd_lock);
 305                 iscsit_free_cmd(cmd);
 306                 spin_lock_bh(&conn->cmd_lock);
 307         }
 308         spin_unlock_bh(&conn->cmd_lock);
 309
 310         pr_debug("Dropped %u total unacknowledged commands on CID:"
 311                 " %hu for ExpCmdSN: 0x%08x.\n", dropped_count, conn->cid,
 312                                 sess->exp_cmd_sn);
 313         return 0;
 314 }
 315
 316 int iscsit_prepare_cmds_for_realligance(struct iscsi_conn *conn)
 317 {
 318         u32 cmd_count = 0;
 319         struct iscsi_cmd *cmd, *cmd_tmp;
 320         struct iscsi_conn_recovery *cr;
 321
 322         /*
 323          * Allocate an struct iscsi_conn_recovery for this connection.
 324          * Each struct iscsi_cmd contains an struct iscsi_conn_recovery pointer
 325          * (struct iscsi_cmd->cr) so we need to allocate this before preparing the
 326          * connection's command list for connection recovery.
 327          */
 328         cr = kzalloc(sizeof(struct iscsi_conn_recovery), GFP_KERNEL);
 329         if (!cr) {
 330                 pr_err("Unable to allocate memory for"
 331                         " struct iscsi_conn_recovery.\n");
 332                 return -1;
 333         }
 334         INIT_LIST_HEAD(&cr->cr_list);
 335         INIT_LIST_HEAD(&cr->conn_recovery_cmd_list);
 336         spin_lock_init(&cr->conn_recovery_cmd_lock);
 337         /*
 338          * Only perform connection recovery on ISCSI_OP_SCSI_CMD or
 339          * ISCSI_OP_NOOP_OUT opcodes.  For all other opcodes call
 340          * list_del(&cmd->i_conn_node); to release the command to the
 341          * session pool and remove it from the connection's list.
 342          *
 343          * Also stop the DataOUT timer, which will be restarted after
 344          * sending the TMR response.
 345          */
 346         spin_lock_bh(&conn->cmd_lock);
 347         list_for_each_entry_safe(cmd, cmd_tmp, &conn->conn_cmd_list, i_conn_node) {
 348
 349                 if ((cmd->iscsi_opcode != ISCSI_OP_SCSI_CMD) &&
 350                     (cmd->iscsi_opcode != ISCSI_OP_NOOP_OUT)) {
 351                         pr_debug("Not performing realligence on"
 352                                 " Opcode: 0x%02x, ITT: 0x%08x, CmdSN: 0x%08x,"
 353                                 " CID: %hu\n", cmd->iscsi_opcode,
 354                                 cmd->init_task_tag, cmd->cmd_sn, conn->cid);
 355
 356                         list_del(&cmd->i_conn_node);
 357                         spin_unlock_bh(&conn->cmd_lock);
 358                         iscsit_free_cmd(cmd);
 359                         spin_lock_bh(&conn->cmd_lock);
 360                         continue;
 361                 }
 362
 363                 /*
 364                  * Special case where commands greater than or equal to
 365                  * the session's ExpCmdSN are attached to the connection
 366                  * list but not to the out of order CmdSN list.  The one
 367                  * obvious case is when a command with immediate data
 368                  * attached must only check the CmdSN against ExpCmdSN
 369                  * after the data is received.  The special case below
 370                  * is when the connection fails before data is received,
 371                  * but also may apply to other PDUs, so it has been
 372                  * made generic here.
 373                  */
 374                 if (!(cmd->cmd_flags & ICF_OOO_CMDSN) && !cmd->immediate_cmd &&
 375                      iscsi_sna_gte(cmd->cmd_sn, conn->sess->exp_cmd_sn)) {
 376                         list_del(&cmd->i_conn_node);
 377                         spin_unlock_bh(&conn->cmd_lock);
 378                         iscsit_free_cmd(cmd);
 379                         spin_lock_bh(&conn->cmd_lock);
 380                         continue;
 381                 }
 382
 383                 cmd_count++;
 384                 pr_debug("Preparing Opcode: 0x%02x, ITT: 0x%08x,"
 385                         " CmdSN: 0x%08x, StatSN: 0x%08x, CID: %hu for"
 386                         " realligence.\n", cmd->iscsi_opcode,
 387                         cmd->init_task_tag, cmd->cmd_sn, cmd->stat_sn,
 388                         conn->cid);
 389
 390                 cmd->deferred_i_state = cmd->i_state;
 391                 cmd->i_state = ISTATE_IN_CONNECTION_RECOVERY;
 392
 393                 if (cmd->data_direction == DMA_TO_DEVICE)
 394                         iscsit_stop_dataout_timer(cmd);
 395
 396                 cmd->sess = conn->sess;
 397
 398                 list_del(&cmd->i_conn_node);
 399                 spin_unlock_bh(&conn->cmd_lock);
 400
 401                 iscsit_free_all_datain_reqs(cmd);
 402
 403                 transport_wait_for_tasks(&cmd->se_cmd);
 404                 /*
 405                  * Add the struct iscsi_cmd to the connection recovery cmd list
 406                  */
 407                 spin_lock(&cr->conn_recovery_cmd_lock);
 408                 list_add_tail(&cmd->i_conn_node, &cr->conn_recovery_cmd_list);
 409                 spin_unlock(&cr->conn_recovery_cmd_lock);
 410
 411                 spin_lock_bh(&conn->cmd_lock);
 412                 cmd->cr = cr;
 413                 cmd->conn = NULL;
 414         }
 415         spin_unlock_bh(&conn->cmd_lock);
 416         /*
 417          * Fill in the various values in the preallocated struct iscsi_conn_recovery.
 418          */
 419         cr->cid = conn->cid;
 420         cr->cmd_count = cmd_count;
 421         cr->maxrecvdatasegmentlength = conn->conn_ops->MaxRecvDataSegmentLength;
 422         cr->maxxmitdatasegmentlength = conn->conn_ops->MaxXmitDataSegmentLength;
 423         cr->sess = conn->sess;
 424
 425         iscsit_attach_inactive_connection_recovery_entry(conn->sess, cr);
 426
 427         return 0;
 428 }
 429
 430 int iscsit_connection_recovery_transport_reset(struct iscsi_conn *conn)
 431 {
 432         atomic_set(&conn->connection_recovery, 1);
 433
 434         if (iscsit_close_connection(conn) < 0)
 435                 return -1;
 436
 437         return 0;
 438 }