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  * (c) Copyright 2007-2013 Datera, Inc.
   6  *
   7  * Author: Nicholas A. Bellinger <nab@linux-iscsi.org>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  ******************************************************************************/
  19
  20 #include <scsi/iscsi_proto.h>
  21 #include <target/target_core_base.h>
  22 #include <target/target_core_fabric.h>
  23
  24 #include "iscsi_target_core.h"
  25 #include "iscsi_target_datain_values.h"
  26 #include "iscsi_target_util.h"
  27 #include "iscsi_target_erl0.h"
  28 #include "iscsi_target_erl1.h"
  29 #include "iscsi_target_erl2.h"
  30 #include "iscsi_target.h"
  31
  32 /*
  33  *      FIXME: Does RData SNACK apply here as well?
  34  */
  35 void iscsit_create_conn_recovery_datain_values(
  36         struct iscsi_cmd *cmd,
  37         __be32 exp_data_sn)
  38 {
  39         u32 data_sn = 0;
  40         struct iscsi_conn *conn = cmd->conn;
  41
  42         cmd->next_burst_len = 0;
  43         cmd->read_data_done = 0;
  44
  45         while (be32_to_cpu(exp_data_sn) > data_sn) {
  46                 if ((cmd->next_burst_len +
  47                      conn->conn_ops->MaxRecvDataSegmentLength) <
  48                      conn->sess->sess_ops->MaxBurstLength) {
  49                         cmd->read_data_done +=
  50                                conn->conn_ops->MaxRecvDataSegmentLength;
  51                         cmd->next_burst_len +=
  52                                conn->conn_ops->MaxRecvDataSegmentLength;
  53                 } else {
  54                         cmd->read_data_done +=
  55                                 (conn->sess->sess_ops->MaxBurstLength -
  56                                 cmd->next_burst_len);
  57                         cmd->next_burst_len = 0;
  58                 }
  59                 data_sn++;
  60         }
  61 }
  62
  63 void iscsit_create_conn_recovery_dataout_values(
  64         struct iscsi_cmd *cmd)
  65 {
  66         u32 write_data_done = 0;
  67         struct iscsi_conn *conn = cmd->conn;
  68
  69         cmd->data_sn = 0;
  70         cmd->next_burst_len = 0;
  71
  72         while (cmd->write_data_done > write_data_done) {
  73                 if ((write_data_done + conn->sess->sess_ops->MaxBurstLength) <=
  74                      cmd->write_data_done)
  75                         write_data_done += conn->sess->sess_ops->MaxBurstLength;
  76                 else
  77                         break;
  78         }
  79
  80         cmd->write_data_done = write_data_done;
  81 }
  82
  83 static int iscsit_attach_active_connection_recovery_entry(
  84         struct iscsi_session *sess,
  85         struct iscsi_conn_recovery *cr)
  86 {
  87         spin_lock(&sess->cr_a_lock);
  88         list_add_tail(&cr->cr_list, &sess->cr_active_list);
  89         spin_unlock(&sess->cr_a_lock);
  90
  91         return 0;
  92 }
  93
  94 static int iscsit_attach_inactive_connection_recovery_entry(
  95         struct iscsi_session *sess,
  96         struct iscsi_conn_recovery *cr)
  97 {
  98         spin_lock(&sess->cr_i_lock);
  99         list_add_tail(&cr->cr_list, &sess->cr_inactive_list);
 100
 101         sess->conn_recovery_count++;
 102         pr_debug("Incremented connection recovery count to %u for"
 103                 " SID: %u\n", sess->conn_recovery_count, sess->sid);
 104         spin_unlock(&sess->cr_i_lock);
 105
 106         return 0;
 107 }
 108
 109 struct iscsi_conn_recovery *iscsit_get_inactive_connection_recovery_entry(
 110         struct iscsi_session *sess,
 111         u16 cid)
 112 {
 113         struct iscsi_conn_recovery *cr;
 114
 115         spin_lock(&sess->cr_i_lock);
 116         list_for_each_entry(cr, &sess->cr_inactive_list, cr_list) {
 117                 if (cr->cid == cid) {
 118                         spin_unlock(&sess->cr_i_lock);
 119                         return cr;
 120                 }
 121         }
 122         spin_unlock(&sess->cr_i_lock);
 123
 124         return NULL;
 125 }
 126
 127 void iscsit_free_connection_recovery_entires(struct iscsi_session *sess)
 128 {
 129         struct iscsi_cmd *cmd, *cmd_tmp;
 130         struct iscsi_conn_recovery *cr, *cr_tmp;
 131
 132         spin_lock(&sess->cr_a_lock);
 133         list_for_each_entry_safe(cr, cr_tmp, &sess->cr_active_list, cr_list) {
 134                 list_del(&cr->cr_list);
 135                 spin_unlock(&sess->cr_a_lock);
 136
 137                 spin_lock(&cr->conn_recovery_cmd_lock);
 138                 list_for_each_entry_safe(cmd, cmd_tmp,
 139                                 &cr->conn_recovery_cmd_list, i_conn_node) {
 140
 141                         list_del_init(&cmd->i_conn_node);
 142                         cmd->conn = NULL;
 143                         spin_unlock(&cr->conn_recovery_cmd_lock);
 144                         iscsit_free_cmd(cmd, true);
 145                         spin_lock(&cr->conn_recovery_cmd_lock);
 146                 }
 147                 spin_unlock(&cr->conn_recovery_cmd_lock);
 148                 spin_lock(&sess->cr_a_lock);
 149
 150                 kfree(cr);
 151         }
 152         spin_unlock(&sess->cr_a_lock);
 153
 154         spin_lock(&sess->cr_i_lock);
 155         list_for_each_entry_safe(cr, cr_tmp, &sess->cr_inactive_list, cr_list) {
 156                 list_del(&cr->cr_list);
 157                 spin_unlock(&sess->cr_i_lock);
 158
 159                 spin_lock(&cr->conn_recovery_cmd_lock);
 160                 list_for_each_entry_safe(cmd, cmd_tmp,
 161                                 &cr->conn_recovery_cmd_list, i_conn_node) {
 162
 163                         list_del_init(&cmd->i_conn_node);
 164                         cmd->conn = NULL;
 165                         spin_unlock(&cr->conn_recovery_cmd_lock);
 166                         iscsit_free_cmd(cmd, true);
 167                         spin_lock(&cr->conn_recovery_cmd_lock);
 168                 }
 169                 spin_unlock(&cr->conn_recovery_cmd_lock);
 170                 spin_lock(&sess->cr_i_lock);
 171
 172                 kfree(cr);
 173         }
 174         spin_unlock(&sess->cr_i_lock);
 175 }
 176
 177 int iscsit_remove_active_connection_recovery_entry(
 178         struct iscsi_conn_recovery *cr,
 179         struct iscsi_session *sess)
 180 {
 181         spin_lock(&sess->cr_a_lock);
 182         list_del(&cr->cr_list);
 183
 184         sess->conn_recovery_count--;
 185         pr_debug("Decremented connection recovery count to %u for"
 186                 " SID: %u\n", sess->conn_recovery_count, sess->sid);
 187         spin_unlock(&sess->cr_a_lock);
 188
 189         kfree(cr);
 190
 191         return 0;
 192 }
 193
 194 static void iscsit_remove_inactive_connection_recovery_entry(
 195         struct iscsi_conn_recovery *cr,
 196         struct iscsi_session *sess)
 197 {
 198         spin_lock(&sess->cr_i_lock);
 199         list_del(&cr->cr_list);
 200         spin_unlock(&sess->cr_i_lock);
 201 }
 202
 203 /*
 204  *      Called with cr->conn_recovery_cmd_lock help.
 205  */
 206 int iscsit_remove_cmd_from_connection_recovery(
 207         struct iscsi_cmd *cmd,
 208         struct iscsi_session *sess)
 209 {
 210         struct iscsi_conn_recovery *cr;
 211
 212         if (!cmd->cr) {
 213                 pr_err("struct iscsi_conn_recovery pointer for ITT: 0x%08x"
 214                         " is NULL!\n", cmd->init_task_tag);
 215                 BUG();
 216         }
 217         cr = cmd->cr;
 218
 219         list_del_init(&cmd->i_conn_node);
 220         return --cr->cmd_count;
 221 }
 222
 223 void iscsit_discard_cr_cmds_by_expstatsn(
 224         struct iscsi_conn_recovery *cr,
 225         u32 exp_statsn)
 226 {
 227         u32 dropped_count = 0;
 228         struct iscsi_cmd *cmd, *cmd_tmp;
 229         struct iscsi_session *sess = cr->sess;
 230
 231         spin_lock(&cr->conn_recovery_cmd_lock);
 232         list_for_each_entry_safe(cmd, cmd_tmp,
 233                         &cr->conn_recovery_cmd_list, i_conn_node) {
 234
 235                 if (((cmd->deferred_i_state != ISTATE_SENT_STATUS) &&
 236                      (cmd->deferred_i_state != ISTATE_REMOVE)) ||
 237                      (cmd->stat_sn >= exp_statsn)) {
 238                         continue;
 239                 }
 240
 241                 dropped_count++;
 242                 pr_debug("Dropping Acknowledged ITT: 0x%08x, StatSN:"
 243                         " 0x%08x, CID: %hu.\n", cmd->init_task_tag,
 244                                 cmd->stat_sn, cr->cid);
 245
 246                 iscsit_remove_cmd_from_connection_recovery(cmd, sess);
 247
 248                 spin_unlock(&cr->conn_recovery_cmd_lock);
 249                 iscsit_free_cmd(cmd, true);
 250                 spin_lock(&cr->conn_recovery_cmd_lock);
 251         }
 252         spin_unlock(&cr->conn_recovery_cmd_lock);
 253
 254         pr_debug("Dropped %u total acknowledged commands on"
 255                 " CID: %hu less than old ExpStatSN: 0x%08x\n",
 256                         dropped_count, cr->cid, exp_statsn);
 257
 258         if (!cr->cmd_count) {
 259                 pr_debug("No commands to be reassigned for failed"
 260                         " connection CID: %hu on SID: %u\n",
 261                         cr->cid, sess->sid);
 262                 iscsit_remove_inactive_connection_recovery_entry(cr, sess);
 263                 iscsit_attach_active_connection_recovery_entry(sess, cr);
 264                 pr_debug("iSCSI connection recovery successful for CID:"
 265                         " %hu on SID: %u\n", cr->cid, sess->sid);
 266                 iscsit_remove_active_connection_recovery_entry(cr, sess);
 267         } else {
 268                 iscsit_remove_inactive_connection_recovery_entry(cr, sess);
 269                 iscsit_attach_active_connection_recovery_entry(sess, cr);
 270         }
 271 }
 272
 273 int iscsit_discard_unacknowledged_ooo_cmdsns_for_conn(struct iscsi_conn *conn)
 274 {
 275         u32 dropped_count = 0;
 276         struct iscsi_cmd *cmd, *cmd_tmp;
 277         struct iscsi_ooo_cmdsn *ooo_cmdsn, *ooo_cmdsn_tmp;
 278         struct iscsi_session *sess = conn->sess;
 279
 280         mutex_lock(&sess->cmdsn_mutex);
 281         list_for_each_entry_safe(ooo_cmdsn, ooo_cmdsn_tmp,
 282                         &sess->sess_ooo_cmdsn_list, ooo_list) {
 283
 284                 if (ooo_cmdsn->cid != conn->cid)
 285                         continue;
 286
 287                 dropped_count++;
 288                 pr_debug("Dropping unacknowledged CmdSN:"
 289                 " 0x%08x during connection recovery on CID: %hu\n",
 290                         ooo_cmdsn->cmdsn, conn->cid);
 291                 iscsit_remove_ooo_cmdsn(sess, ooo_cmdsn);
 292         }
 293         mutex_unlock(&sess->cmdsn_mutex);
 294
 295         spin_lock_bh(&conn->cmd_lock);
 296         list_for_each_entry_safe(cmd, cmd_tmp, &conn->conn_cmd_list, i_conn_node) {
 297                 if (!(cmd->cmd_flags & ICF_OOO_CMDSN))
 298                         continue;
 299
 300                 list_del_init(&cmd->i_conn_node);
 301
 302                 spin_unlock_bh(&conn->cmd_lock);
 303                 iscsit_free_cmd(cmd, true);
 304                 spin_lock_bh(&conn->cmd_lock);
 305         }
 306         spin_unlock_bh(&conn->cmd_lock);
 307
 308         pr_debug("Dropped %u total unacknowledged commands on CID:"
 309                 " %hu for ExpCmdSN: 0x%08x.\n", dropped_count, conn->cid,
 310                                 sess->exp_cmd_sn);
 311         return 0;
 312 }
 313
 314 int iscsit_prepare_cmds_for_realligance(struct iscsi_conn *conn)
 315 {
 316         u32 cmd_count = 0;
 317         struct iscsi_cmd *cmd, *cmd_tmp;
 318         struct iscsi_conn_recovery *cr;
 319
 320         /*
 321          * Allocate an struct iscsi_conn_recovery for this connection.
 322          * Each struct iscsi_cmd contains an struct iscsi_conn_recovery pointer
 323          * (struct iscsi_cmd->cr) so we need to allocate this before preparing the
 324          * connection's command list for connection recovery.
 325          */
 326         cr = kzalloc(sizeof(struct iscsi_conn_recovery), GFP_KERNEL);
 327         if (!cr) {
 328                 pr_err("Unable to allocate memory for"
 329                         " struct iscsi_conn_recovery.\n");
 330                 return -1;
 331         }
 332         INIT_LIST_HEAD(&cr->cr_list);
 333         INIT_LIST_HEAD(&cr->conn_recovery_cmd_list);
 334         spin_lock_init(&cr->conn_recovery_cmd_lock);
 335         /*
 336          * Only perform connection recovery on ISCSI_OP_SCSI_CMD or
 337          * ISCSI_OP_NOOP_OUT opcodes.  For all other opcodes call
 338          * list_del_init(&cmd->i_conn_node); to release the command to the
 339          * session pool and remove it from the connection's list.
 340          *
 341          * Also stop the DataOUT timer, which will be restarted after
 342          * sending the TMR response.
 343          */
 344         spin_lock_bh(&conn->cmd_lock);
 345         list_for_each_entry_safe(cmd, cmd_tmp, &conn->conn_cmd_list, i_conn_node) {
 346
 347                 if ((cmd->iscsi_opcode != ISCSI_OP_SCSI_CMD) &&
 348                     (cmd->iscsi_opcode != ISCSI_OP_NOOP_OUT)) {
 349                         pr_debug("Not performing realligence on"
 350                                 " Opcode: 0x%02x, ITT: 0x%08x, CmdSN: 0x%08x,"
 351                                 " CID: %hu\n", cmd->iscsi_opcode,
 352                                 cmd->init_task_tag, cmd->cmd_sn, conn->cid);
 353
 354                         list_del_init(&cmd->i_conn_node);
 355                         spin_unlock_bh(&conn->cmd_lock);
 356                         iscsit_free_cmd(cmd, true);
 357                         spin_lock_bh(&conn->cmd_lock);
 358                         continue;
 359                 }
 360
 361                 /*
 362                  * Special case where commands greater than or equal to
 363                  * the session's ExpCmdSN are attached to the connection
 364                  * list but not to the out of order CmdSN list.  The one
 365                  * obvious case is when a command with immediate data
 366                  * attached must only check the CmdSN against ExpCmdSN
 367                  * after the data is received.  The special case below
 368                  * is when the connection fails before data is received,
 369                  * but also may apply to other PDUs, so it has been
 370                  * made generic here.
 371                  */
 372                 if (!(cmd->cmd_flags & ICF_OOO_CMDSN) && !cmd->immediate_cmd &&
 373                      iscsi_sna_gte(cmd->cmd_sn, conn->sess->exp_cmd_sn)) {
 374                         list_del_init(&cmd->i_conn_node);
 375                         spin_unlock_bh(&conn->cmd_lock);
 376                         iscsit_free_cmd(cmd, true);
 377                         spin_lock_bh(&conn->cmd_lock);
 378                         continue;
 379                 }
 380
 381                 cmd_count++;
 382                 pr_debug("Preparing Opcode: 0x%02x, ITT: 0x%08x,"
 383                         " CmdSN: 0x%08x, StatSN: 0x%08x, CID: %hu for"
 384                         " realligence.\n", cmd->iscsi_opcode,
 385                         cmd->init_task_tag, cmd->cmd_sn, cmd->stat_sn,
 386                         conn->cid);
 387
 388                 cmd->deferred_i_state = cmd->i_state;
 389                 cmd->i_state = ISTATE_IN_CONNECTION_RECOVERY;
 390
 391                 if (cmd->data_direction == DMA_TO_DEVICE)
 392                         iscsit_stop_dataout_timer(cmd);
 393
 394                 cmd->sess = conn->sess;
 395
 396                 list_del_init(&cmd->i_conn_node);
 397                 spin_unlock_bh(&conn->cmd_lock);
 398
 399                 iscsit_free_all_datain_reqs(cmd);
 400
 401                 transport_wait_for_tasks(&cmd->se_cmd);
 402                 /*
 403                  * Add the struct iscsi_cmd to the connection recovery cmd list
 404                  */
 405                 spin_lock(&cr->conn_recovery_cmd_lock);
 406                 list_add_tail(&cmd->i_conn_node, &cr->conn_recovery_cmd_list);
 407                 spin_unlock(&cr->conn_recovery_cmd_lock);
 408
 409                 spin_lock_bh(&conn->cmd_lock);
 410                 cmd->cr = cr;
 411                 cmd->conn = NULL;
 412         }
 413         spin_unlock_bh(&conn->cmd_lock);
 414         /*
 415          * Fill in the various values in the preallocated struct iscsi_conn_recovery.
 416          */
 417         cr->cid = conn->cid;
 418         cr->cmd_count = cmd_count;
 419         cr->maxrecvdatasegmentlength = conn->conn_ops->MaxRecvDataSegmentLength;
 420         cr->maxxmitdatasegmentlength = conn->conn_ops->MaxXmitDataSegmentLength;
 421         cr->sess = conn->sess;
 422
 423         iscsit_attach_inactive_connection_recovery_entry(conn->sess, cr);
 424
 425         return 0;
 426 }
 427
 428 int iscsit_connection_recovery_transport_reset(struct iscsi_conn *conn)
 429 {
 430         atomic_set(&conn->connection_recovery, 1);
 431
 432         if (iscsit_close_connection(conn) < 0)
 433                 return -1;
 434
 435         return 0;
 436 }