LXR linux/drivers/target/iscsi/iscsi_target

   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 */
  35void 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
  63void 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
  83static 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
  94static 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
 109struct 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
 127void 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
 177int 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
 194static 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 */
 206int 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
 223void 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
 273int 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
 314int 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
 428int 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}
 437