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 <linux/slab.h>
  21 #include <scsi/iscsi_proto.h>
  22 #include <target/target_core_base.h>
  23 #include <target/target_core_fabric.h>
  24
  25 #include <target/iscsi/iscsi_target_core.h>
  26 #include "iscsi_target_datain_values.h"
  27 #include "iscsi_target_util.h"
  28 #include "iscsi_target_erl0.h"
  29 #include "iscsi_target_erl1.h"
  30 #include "iscsi_target_erl2.h"
  31 #include "iscsi_target.h"
  32
  33 /*
  34  *      FIXME: Does RData SNACK apply here as well?
  35  */
  36 void iscsit_create_conn_recovery_datain_values(
  37         struct iscsi_cmd *cmd,
  38         __be32 exp_data_sn)
  39 {
  40         u32 data_sn = 0;
  41         struct iscsi_conn *conn = cmd->conn;
  42
  43         cmd->next_burst_len = 0;
  44         cmd->read_data_done = 0;
  45
  46         while (be32_to_cpu(exp_data_sn) > data_sn) {
  47                 if ((cmd->next_burst_len +
  48                      conn->conn_ops->MaxRecvDataSegmentLength) <
  49                      conn->sess->sess_ops->MaxBurstLength) {
  50                         cmd->read_data_done +=
  51                                conn->conn_ops->MaxRecvDataSegmentLength;
  52                         cmd->next_burst_len +=
  53                                conn->conn_ops->MaxRecvDataSegmentLength;
  54                 } else {
  55                         cmd->read_data_done +=
  56                                 (conn->sess->sess_ops->MaxBurstLength -
  57                                 cmd->next_burst_len);
  58                         cmd->next_burst_len = 0;
  59                 }
  60                 data_sn++;
  61         }
  62 }
  63
  64 void iscsit_create_conn_recovery_dataout_values(
  65         struct iscsi_cmd *cmd)
  66 {
  67         u32 write_data_done = 0;
  68         struct iscsi_conn *conn = cmd->conn;
  69
  70         cmd->data_sn = 0;
  71         cmd->next_burst_len = 0;
  72
  73         while (cmd->write_data_done > write_data_done) {
  74                 if ((write_data_done + conn->sess->sess_ops->MaxBurstLength) <=
  75                      cmd->write_data_done)
  76                         write_data_done += conn->sess->sess_ops->MaxBurstLength;
  77                 else
  78                         break;
  79         }
  80
  81         cmd->write_data_done = write_data_done;
  82 }
  83
  84 static int iscsit_attach_active_connection_recovery_entry(
  85         struct iscsi_session *sess,
  86         struct iscsi_conn_recovery *cr)
  87 {
  88         spin_lock(&sess->cr_a_lock);
  89         list_add_tail(&cr->cr_list, &sess->cr_active_list);
  90         spin_unlock(&sess->cr_a_lock);
  91
  92         return 0;
  93 }
  94
  95 static int iscsit_attach_inactive_connection_recovery_entry(
  96         struct iscsi_session *sess,
  97         struct iscsi_conn_recovery *cr)
  98 {
  99         spin_lock(&sess->cr_i_lock);
 100         list_add_tail(&cr->cr_list, &sess->cr_inactive_list);
 101
 102         sess->conn_recovery_count++;
 103         pr_debug("Incremented connection recovery count to %u for"
 104                 " SID: %u\n", sess->conn_recovery_count, sess->sid);
 105         spin_unlock(&sess->cr_i_lock);
 106
 107         return 0;
 108 }
 109
 110 struct iscsi_conn_recovery *iscsit_get_inactive_connection_recovery_entry(
 111         struct iscsi_session *sess,
 112         u16 cid)
 113 {
 114         struct iscsi_conn_recovery *cr;
 115
 116         spin_lock(&sess->cr_i_lock);
 117         list_for_each_entry(cr, &sess->cr_inactive_list, cr_list) {
 118                 if (cr->cid == cid) {
 119                         spin_unlock(&sess->cr_i_lock);
 120                         return cr;
 121                 }
 122         }
 123         spin_unlock(&sess->cr_i_lock);
 124
 125         return NULL;
 126 }
 127
 128 void iscsit_free_connection_recovery_entires(struct iscsi_session *sess)
 129 {
 130         struct iscsi_cmd *cmd, *cmd_tmp;
 131         struct iscsi_conn_recovery *cr, *cr_tmp;
 132
 133         spin_lock(&sess->cr_a_lock);
 134         list_for_each_entry_safe(cr, cr_tmp, &sess->cr_active_list, cr_list) {
 135                 list_del(&cr->cr_list);
 136                 spin_unlock(&sess->cr_a_lock);
 137
 138                 spin_lock(&cr->conn_recovery_cmd_lock);
 139                 list_for_each_entry_safe(cmd, cmd_tmp,
 140                                 &cr->conn_recovery_cmd_list, i_conn_node) {
 141
 142                         list_del_init(&cmd->i_conn_node);
 143                         cmd->conn = NULL;
 144                         spin_unlock(&cr->conn_recovery_cmd_lock);
 145                         iscsit_free_cmd(cmd, true);
 146                         spin_lock(&cr->conn_recovery_cmd_lock);
 147                 }
 148                 spin_unlock(&cr->conn_recovery_cmd_lock);
 149                 spin_lock(&sess->cr_a_lock);
 150
 151                 kfree(cr);
 152         }
 153         spin_unlock(&sess->cr_a_lock);
 154
 155         spin_lock(&sess->cr_i_lock);
 156         list_for_each_entry_safe(cr, cr_tmp, &sess->cr_inactive_list, cr_list) {
 157                 list_del(&cr->cr_list);
 158                 spin_unlock(&sess->cr_i_lock);
 159
 160                 spin_lock(&cr->conn_recovery_cmd_lock);
 161                 list_for_each_entry_safe(cmd, cmd_tmp,
 162                                 &cr->conn_recovery_cmd_list, i_conn_node) {
 163
 164                         list_del_init(&cmd->i_conn_node);
 165                         cmd->conn = NULL;
 166                         spin_unlock(&cr->conn_recovery_cmd_lock);
 167                         iscsit_free_cmd(cmd, true);
 168                         spin_lock(&cr->conn_recovery_cmd_lock);
 169                 }
 170                 spin_unlock(&cr->conn_recovery_cmd_lock);
 171                 spin_lock(&sess->cr_i_lock);
 172
 173                 kfree(cr);
 174         }
 175         spin_unlock(&sess->cr_i_lock);
 176 }
 177
 178 int iscsit_remove_active_connection_recovery_entry(
 179         struct iscsi_conn_recovery *cr,
 180         struct iscsi_session *sess)
 181 {
 182         spin_lock(&sess->cr_a_lock);
 183         list_del(&cr->cr_list);
 184
 185         sess->conn_recovery_count--;
 186         pr_debug("Decremented connection recovery count to %u for"
 187                 " SID: %u\n", sess->conn_recovery_count, sess->sid);
 188         spin_unlock(&sess->cr_a_lock);
 189
 190         kfree(cr);
 191
 192         return 0;
 193 }
 194
 195 static void iscsit_remove_inactive_connection_recovery_entry(
 196         struct iscsi_conn_recovery *cr,
 197         struct iscsi_session *sess)
 198 {
 199         spin_lock(&sess->cr_i_lock);
 200         list_del(&cr->cr_list);
 201         spin_unlock(&sess->cr_i_lock);
 202 }
 203
 204 /*
 205  *      Called with cr->conn_recovery_cmd_lock help.
 206  */
 207 int iscsit_remove_cmd_from_connection_recovery(
 208         struct iscsi_cmd *cmd,
 209         struct iscsi_session *sess)
 210 {
 211         struct iscsi_conn_recovery *cr;
 212
 213         if (!cmd->cr) {
 214                 pr_err("struct iscsi_conn_recovery pointer for ITT: 0x%08x"
 215                         " is NULL!\n", cmd->init_task_tag);
 216                 BUG();
 217         }
 218         cr = cmd->cr;
 219
 220         list_del_init(&cmd->i_conn_node);
 221         return --cr->cmd_count;
 222 }
 223
 224 void iscsit_discard_cr_cmds_by_expstatsn(
 225         struct iscsi_conn_recovery *cr,
 226         u32 exp_statsn)
 227 {
 228         u32 dropped_count = 0;
 229         struct iscsi_cmd *cmd, *cmd_tmp;
 230         struct iscsi_session *sess = cr->sess;
 231
 232         spin_lock(&cr->conn_recovery_cmd_lock);
 233         list_for_each_entry_safe(cmd, cmd_tmp,
 234                         &cr->conn_recovery_cmd_list, i_conn_node) {
 235
 236                 if (((cmd->deferred_i_state != ISTATE_SENT_STATUS) &&
 237                      (cmd->deferred_i_state != ISTATE_REMOVE)) ||
 238                      (cmd->stat_sn >= exp_statsn)) {
 239                         continue;
 240                 }
 241
 242                 dropped_count++;
 243                 pr_debug("Dropping Acknowledged ITT: 0x%08x, StatSN:"
 244                         " 0x%08x, CID: %hu.\n", cmd->init_task_tag,
 245                                 cmd->stat_sn, cr->cid);
 246
 247                 iscsit_remove_cmd_from_connection_recovery(cmd, sess);
 248
 249                 spin_unlock(&cr->conn_recovery_cmd_lock);
 250                 iscsit_free_cmd(cmd, true);
 251                 spin_lock(&cr->conn_recovery_cmd_lock);
 252         }
 253         spin_unlock(&cr->conn_recovery_cmd_lock);
 254
 255         pr_debug("Dropped %u total acknowledged commands on"
 256                 " CID: %hu less than old ExpStatSN: 0x%08x\n",
 257                         dropped_count, cr->cid, exp_statsn);
 258
 259         if (!cr->cmd_count) {
 260                 pr_debug("No commands to be reassigned for failed"
 261                         " connection CID: %hu on SID: %u\n",
 262                         cr->cid, sess->sid);
 263                 iscsit_remove_inactive_connection_recovery_entry(cr, sess);
 264                 iscsit_attach_active_connection_recovery_entry(sess, cr);
 265                 pr_debug("iSCSI connection recovery successful for CID:"
 266                         " %hu on SID: %u\n", cr->cid, sess->sid);
 267                 iscsit_remove_active_connection_recovery_entry(cr, sess);
 268         } else {
 269                 iscsit_remove_inactive_connection_recovery_entry(cr, sess);
 270                 iscsit_attach_active_connection_recovery_entry(sess, cr);
 271         }
 272 }
 273
 274 int iscsit_discard_unacknowledged_ooo_cmdsns_for_conn(struct iscsi_conn *conn)
 275 {
 276         u32 dropped_count = 0;
 277         struct iscsi_cmd *cmd, *cmd_tmp;
 278         struct iscsi_ooo_cmdsn *ooo_cmdsn, *ooo_cmdsn_tmp;
 279         struct iscsi_session *sess = conn->sess;
 280
 281         mutex_lock(&sess->cmdsn_mutex);
 282         list_for_each_entry_safe(ooo_cmdsn, ooo_cmdsn_tmp,
 283                         &sess->sess_ooo_cmdsn_list, ooo_list) {
 284
 285                 if (ooo_cmdsn->cid != conn->cid)
 286                         continue;
 287
 288                 dropped_count++;
 289                 pr_debug("Dropping unacknowledged CmdSN:"
 290                 " 0x%08x during connection recovery on CID: %hu\n",
 291                         ooo_cmdsn->cmdsn, conn->cid);
 292                 iscsit_remove_ooo_cmdsn(sess, ooo_cmdsn);
 293         }
 294         mutex_unlock(&sess->cmdsn_mutex);
 295
 296         spin_lock_bh(&conn->cmd_lock);
 297         list_for_each_entry_safe(cmd, cmd_tmp, &conn->conn_cmd_list, i_conn_node) {
 298                 if (!(cmd->cmd_flags & ICF_OOO_CMDSN))
 299                         continue;
 300
 301                 list_del_init(&cmd->i_conn_node);
 302
 303                 spin_unlock_bh(&conn->cmd_lock);
 304                 iscsit_free_cmd(cmd, true);
 305                 spin_lock_bh(&conn->cmd_lock);
 306         }
 307         spin_unlock_bh(&conn->cmd_lock);
 308
 309         pr_debug("Dropped %u total unacknowledged commands on CID:"
 310                 " %hu for ExpCmdSN: 0x%08x.\n", dropped_count, conn->cid,
 311                                 sess->exp_cmd_sn);
 312         return 0;
 313 }
 314
 315 int iscsit_prepare_cmds_for_reallegiance(struct iscsi_conn *conn)
 316 {
 317         u32 cmd_count = 0;
 318         struct iscsi_cmd *cmd, *cmd_tmp;
 319         struct iscsi_conn_recovery *cr;
 320
 321         /*
 322          * Allocate an struct iscsi_conn_recovery for this connection.
 323          * Each struct iscsi_cmd contains an struct iscsi_conn_recovery pointer
 324          * (struct iscsi_cmd->cr) so we need to allocate this before preparing the
 325          * connection's command list for connection recovery.
 326          */
 327         cr = kzalloc(sizeof(struct iscsi_conn_recovery), GFP_KERNEL);
 328         if (!cr) {
 329                 pr_err("Unable to allocate memory for"
 330                         " struct iscsi_conn_recovery.\n");
 331                 return -1;
 332         }
 333         INIT_LIST_HEAD(&cr->cr_list);
 334         INIT_LIST_HEAD(&cr->conn_recovery_cmd_list);
 335         spin_lock_init(&cr->conn_recovery_cmd_lock);
 336         /*
 337          * Only perform connection recovery on ISCSI_OP_SCSI_CMD or
 338          * ISCSI_OP_NOOP_OUT opcodes.  For all other opcodes call
 339          * list_del_init(&cmd->i_conn_node); to release the command to the
 340          * session pool and remove it from the connection's list.
 341          *
 342          * Also stop the DataOUT timer, which will be restarted after
 343          * sending the TMR response.
 344          */
 345         spin_lock_bh(&conn->cmd_lock);
 346         list_for_each_entry_safe(cmd, cmd_tmp, &conn->conn_cmd_list, i_conn_node) {
 347
 348                 if ((cmd->iscsi_opcode != ISCSI_OP_SCSI_CMD) &&
 349                     (cmd->iscsi_opcode != ISCSI_OP_NOOP_OUT)) {
 350                         pr_debug("Not performing reallegiance on"
 351                                 " Opcode: 0x%02x, ITT: 0x%08x, CmdSN: 0x%08x,"
 352                                 " CID: %hu\n", cmd->iscsi_opcode,
 353                                 cmd->init_task_tag, cmd->cmd_sn, conn->cid);
 354
 355                         list_del_init(&cmd->i_conn_node);
 356                         spin_unlock_bh(&conn->cmd_lock);
 357                         iscsit_free_cmd(cmd, true);
 358                         spin_lock_bh(&conn->cmd_lock);
 359                         continue;
 360                 }
 361
 362                 /*
 363                  * Special case where commands greater than or equal to
 364                  * the session's ExpCmdSN are attached to the connection
 365                  * list but not to the out of order CmdSN list.  The one
 366                  * obvious case is when a command with immediate data
 367                  * attached must only check the CmdSN against ExpCmdSN
 368                  * after the data is received.  The special case below
 369                  * is when the connection fails before data is received,
 370                  * but also may apply to other PDUs, so it has been
 371                  * made generic here.
 372                  */
 373                 if (!(cmd->cmd_flags & ICF_OOO_CMDSN) && !cmd->immediate_cmd &&
 374                      iscsi_sna_gte(cmd->cmd_sn, conn->sess->exp_cmd_sn)) {
 375                         list_del_init(&cmd->i_conn_node);
 376                         spin_unlock_bh(&conn->cmd_lock);
 377                         iscsit_free_cmd(cmd, true);
 378                         spin_lock_bh(&conn->cmd_lock);
 379                         continue;
 380                 }
 381
 382                 cmd_count++;
 383                 pr_debug("Preparing Opcode: 0x%02x, ITT: 0x%08x,"
 384                         " CmdSN: 0x%08x, StatSN: 0x%08x, CID: %hu for"
 385                         " reallegiance.\n", cmd->iscsi_opcode,
 386                         cmd->init_task_tag, cmd->cmd_sn, cmd->stat_sn,
 387                         conn->cid);
 388
 389                 cmd->deferred_i_state = cmd->i_state;
 390                 cmd->i_state = ISTATE_IN_CONNECTION_RECOVERY;
 391
 392                 if (cmd->data_direction == DMA_TO_DEVICE)
 393                         iscsit_stop_dataout_timer(cmd);
 394
 395                 cmd->sess = conn->sess;
 396
 397                 list_del_init(&cmd->i_conn_node);
 398                 spin_unlock_bh(&conn->cmd_lock);
 399
 400                 iscsit_free_all_datain_reqs(cmd);
 401
 402                 transport_wait_for_tasks(&cmd->se_cmd);
 403                 /*
 404                  * Add the struct iscsi_cmd to the connection recovery cmd list
 405                  */
 406                 spin_lock(&cr->conn_recovery_cmd_lock);
 407                 list_add_tail(&cmd->i_conn_node, &cr->conn_recovery_cmd_list);
 408                 spin_unlock(&cr->conn_recovery_cmd_lock);
 409
 410                 spin_lock_bh(&conn->cmd_lock);
 411                 cmd->cr = cr;
 412                 cmd->conn = NULL;
 413         }
 414         spin_unlock_bh(&conn->cmd_lock);
 415         /*
 416          * Fill in the various values in the preallocated struct iscsi_conn_recovery.
 417          */
 418         cr->cid = conn->cid;
 419         cr->cmd_count = cmd_count;
 420         cr->maxrecvdatasegmentlength = conn->conn_ops->MaxRecvDataSegmentLength;
 421         cr->maxxmitdatasegmentlength = conn->conn_ops->MaxXmitDataSegmentLength;
 422         cr->sess = conn->sess;
 423
 424         iscsit_attach_inactive_connection_recovery_entry(conn->sess, cr);
 425
 426         return 0;
 427 }
 428
 429 int iscsit_connection_recovery_transport_reset(struct iscsi_conn *conn)
 430 {
 431         atomic_set(&conn->connection_recovery, 1);
 432
 433         if (iscsit_close_connection(conn) < 0)
 434                 return -1;
 435
 436         return 0;
 437 }