drivers/target/iscsi/iscsi_target_erl2.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*******************************************************************************
   3  * This file contains error recovery level two functions used by
   4  * the iSCSI Target driver.
   5  *
   6  * (c) Copyright 2007-2013 Datera, Inc.
   7  *
   8  * Author: Nicholas A. Bellinger <nab@linux-iscsi.org>
   9  *
  10  ******************************************************************************/
  11
  12 #include <linux/slab.h>
  13 #include <scsi/iscsi_proto.h>
  14 #include <target/target_core_base.h>
  15 #include <target/target_core_fabric.h>
  16
  17 #include <target/iscsi/iscsi_target_core.h>
  18 #include "iscsi_target_datain_values.h"
  19 #include "iscsi_target_util.h"
  20 #include "iscsi_target_erl0.h"
  21 #include "iscsi_target_erl1.h"
  22 #include "iscsi_target_erl2.h"
  23 #include "iscsi_target.h"
  24
  25 /*
  26  *      FIXME: Does RData SNACK apply here as well?
  27  */
  28 void iscsit_create_conn_recovery_datain_values(
  29         struct iscsi_cmd *cmd,
  30         __be32 exp_data_sn)
  31 {
  32         u32 data_sn = 0;
  33         struct iscsi_conn *conn = cmd->conn;
  34
  35         cmd->next_burst_len = 0;
  36         cmd->read_data_done = 0;
  37
  38         while (be32_to_cpu(exp_data_sn) > data_sn) {
  39                 if ((cmd->next_burst_len +
  40                      conn->conn_ops->MaxRecvDataSegmentLength) <
  41                      conn->sess->sess_ops->MaxBurstLength) {
  42                         cmd->read_data_done +=
  43                                conn->conn_ops->MaxRecvDataSegmentLength;
  44                         cmd->next_burst_len +=
  45                                conn->conn_ops->MaxRecvDataSegmentLength;
  46                 } else {
  47                         cmd->read_data_done +=
  48                                 (conn->sess->sess_ops->MaxBurstLength -
  49                                 cmd->next_burst_len);
  50                         cmd->next_burst_len = 0;
  51                 }
  52                 data_sn++;
  53         }
  54 }
  55
  56 void iscsit_create_conn_recovery_dataout_values(
  57         struct iscsi_cmd *cmd)
  58 {
  59         u32 write_data_done = 0;
  60         struct iscsi_conn *conn = cmd->conn;
  61
  62         cmd->data_sn = 0;
  63         cmd->next_burst_len = 0;
  64
  65         while (cmd->write_data_done > write_data_done) {
  66                 if ((write_data_done + conn->sess->sess_ops->MaxBurstLength) <=
  67                      cmd->write_data_done)
  68                         write_data_done += conn->sess->sess_ops->MaxBurstLength;
  69                 else
  70                         break;
  71         }
  72
  73         cmd->write_data_done = write_data_done;
  74 }
  75
  76 static int iscsit_attach_active_connection_recovery_entry(
  77         struct iscsi_session *sess,
  78         struct iscsi_conn_recovery *cr)
  79 {
  80         spin_lock(&sess->cr_a_lock);
  81         list_add_tail(&cr->cr_list, &sess->cr_active_list);
  82         spin_unlock(&sess->cr_a_lock);
  83
  84         return 0;
  85 }
  86
  87 static int iscsit_attach_inactive_connection_recovery_entry(
  88         struct iscsi_session *sess,
  89         struct iscsi_conn_recovery *cr)
  90 {
  91         spin_lock(&sess->cr_i_lock);
  92         list_add_tail(&cr->cr_list, &sess->cr_inactive_list);
  93
  94         sess->conn_recovery_count++;
  95         pr_debug("Incremented connection recovery count to %u for"
  96                 " SID: %u\n", sess->conn_recovery_count, sess->sid);
  97         spin_unlock(&sess->cr_i_lock);
  98
  99         return 0;
 100 }
 101
 102 struct iscsi_conn_recovery *iscsit_get_inactive_connection_recovery_entry(
 103         struct iscsi_session *sess,
 104         u16 cid)
 105 {
 106         struct iscsi_conn_recovery *cr;
 107
 108         spin_lock(&sess->cr_i_lock);
 109         list_for_each_entry(cr, &sess->cr_inactive_list, cr_list) {
 110                 if (cr->cid == cid) {
 111                         spin_unlock(&sess->cr_i_lock);
 112                         return cr;
 113                 }
 114         }
 115         spin_unlock(&sess->cr_i_lock);
 116
 117         return NULL;
 118 }
 119
 120 void iscsit_free_connection_recovery_entries(struct iscsi_session *sess)
 121 {
 122         struct iscsi_cmd *cmd, *cmd_tmp;
 123         struct iscsi_conn_recovery *cr, *cr_tmp;
 124
 125         spin_lock(&sess->cr_a_lock);
 126         list_for_each_entry_safe(cr, cr_tmp, &sess->cr_active_list, cr_list) {
 127                 list_del(&cr->cr_list);
 128                 spin_unlock(&sess->cr_a_lock);
 129
 130                 spin_lock(&cr->conn_recovery_cmd_lock);
 131                 list_for_each_entry_safe(cmd, cmd_tmp,
 132                                 &cr->conn_recovery_cmd_list, i_conn_node) {
 133
 134                         list_del_init(&cmd->i_conn_node);
 135                         cmd->conn = NULL;
 136                         spin_unlock(&cr->conn_recovery_cmd_lock);
 137                         iscsit_free_cmd(cmd, true);
 138                         spin_lock(&cr->conn_recovery_cmd_lock);
 139                 }
 140                 spin_unlock(&cr->conn_recovery_cmd_lock);
 141                 spin_lock(&sess->cr_a_lock);
 142
 143                 kfree(cr);
 144         }
 145         spin_unlock(&sess->cr_a_lock);
 146
 147         spin_lock(&sess->cr_i_lock);
 148         list_for_each_entry_safe(cr, cr_tmp, &sess->cr_inactive_list, cr_list) {
 149                 list_del(&cr->cr_list);
 150                 spin_unlock(&sess->cr_i_lock);
 151
 152                 spin_lock(&cr->conn_recovery_cmd_lock);
 153                 list_for_each_entry_safe(cmd, cmd_tmp,
 154                                 &cr->conn_recovery_cmd_list, i_conn_node) {
 155
 156                         list_del_init(&cmd->i_conn_node);
 157                         cmd->conn = NULL;
 158                         spin_unlock(&cr->conn_recovery_cmd_lock);
 159                         iscsit_free_cmd(cmd, true);
 160                         spin_lock(&cr->conn_recovery_cmd_lock);
 161                 }
 162                 spin_unlock(&cr->conn_recovery_cmd_lock);
 163                 spin_lock(&sess->cr_i_lock);
 164
 165                 kfree(cr);
 166         }
 167         spin_unlock(&sess->cr_i_lock);
 168 }
 169
 170 int iscsit_remove_active_connection_recovery_entry(
 171         struct iscsi_conn_recovery *cr,
 172         struct iscsi_session *sess)
 173 {
 174         spin_lock(&sess->cr_a_lock);
 175         list_del(&cr->cr_list);
 176
 177         sess->conn_recovery_count--;
 178         pr_debug("Decremented connection recovery count to %u for"
 179                 " SID: %u\n", sess->conn_recovery_count, sess->sid);
 180         spin_unlock(&sess->cr_a_lock);
 181
 182         kfree(cr);
 183
 184         return 0;
 185 }
 186
 187 static void iscsit_remove_inactive_connection_recovery_entry(
 188         struct iscsi_conn_recovery *cr,
 189         struct iscsi_session *sess)
 190 {
 191         spin_lock(&sess->cr_i_lock);
 192         list_del(&cr->cr_list);
 193         spin_unlock(&sess->cr_i_lock);
 194 }
 195
 196 /*
 197  *      Called with cr->conn_recovery_cmd_lock help.
 198  */
 199 int iscsit_remove_cmd_from_connection_recovery(
 200         struct iscsi_cmd *cmd,
 201         struct iscsi_session *sess)
 202 {
 203         struct iscsi_conn_recovery *cr;
 204
 205         if (!cmd->cr) {
 206                 pr_err("struct iscsi_conn_recovery pointer for ITT: 0x%08x"
 207                         " is NULL!\n", cmd->init_task_tag);
 208                 BUG();
 209         }
 210         cr = cmd->cr;
 211
 212         list_del_init(&cmd->i_conn_node);
 213         return --cr->cmd_count;
 214 }
 215
 216 void iscsit_discard_cr_cmds_by_expstatsn(
 217         struct iscsi_conn_recovery *cr,
 218         u32 exp_statsn)
 219 {
 220         u32 dropped_count = 0;
 221         struct iscsi_cmd *cmd, *cmd_tmp;
 222         struct iscsi_session *sess = cr->sess;
 223
 224         spin_lock(&cr->conn_recovery_cmd_lock);
 225         list_for_each_entry_safe(cmd, cmd_tmp,
 226                         &cr->conn_recovery_cmd_list, i_conn_node) {
 227
 228                 if (((cmd->deferred_i_state != ISTATE_SENT_STATUS) &&
 229                      (cmd->deferred_i_state != ISTATE_REMOVE)) ||
 230                      (cmd->stat_sn >= exp_statsn)) {
 231                         continue;
 232                 }
 233
 234                 dropped_count++;
 235                 pr_debug("Dropping Acknowledged ITT: 0x%08x, StatSN:"
 236                         " 0x%08x, CID: %hu.\n", cmd->init_task_tag,
 237                                 cmd->stat_sn, cr->cid);
 238
 239                 iscsit_remove_cmd_from_connection_recovery(cmd, sess);
 240
 241                 spin_unlock(&cr->conn_recovery_cmd_lock);
 242                 iscsit_free_cmd(cmd, true);
 243                 spin_lock(&cr->conn_recovery_cmd_lock);
 244         }
 245         spin_unlock(&cr->conn_recovery_cmd_lock);
 246
 247         pr_debug("Dropped %u total acknowledged commands on"
 248                 " CID: %hu less than old ExpStatSN: 0x%08x\n",
 249                         dropped_count, cr->cid, exp_statsn);
 250
 251         if (!cr->cmd_count) {
 252                 pr_debug("No commands to be reassigned for failed"
 253                         " connection CID: %hu on SID: %u\n",
 254                         cr->cid, sess->sid);
 255                 iscsit_remove_inactive_connection_recovery_entry(cr, sess);
 256                 iscsit_attach_active_connection_recovery_entry(sess, cr);
 257                 pr_debug("iSCSI connection recovery successful for CID:"
 258                         " %hu on SID: %u\n", cr->cid, sess->sid);
 259                 iscsit_remove_active_connection_recovery_entry(cr, sess);
 260         } else {
 261                 iscsit_remove_inactive_connection_recovery_entry(cr, sess);
 262                 iscsit_attach_active_connection_recovery_entry(sess, cr);
 263         }
 264 }
 265
 266 int iscsit_discard_unacknowledged_ooo_cmdsns_for_conn(struct iscsi_conn *conn)
 267 {
 268         u32 dropped_count = 0;
 269         struct iscsi_cmd *cmd, *cmd_tmp;
 270         struct iscsi_ooo_cmdsn *ooo_cmdsn, *ooo_cmdsn_tmp;
 271         struct iscsi_session *sess = conn->sess;
 272
 273         mutex_lock(&sess->cmdsn_mutex);
 274         list_for_each_entry_safe(ooo_cmdsn, ooo_cmdsn_tmp,
 275                         &sess->sess_ooo_cmdsn_list, ooo_list) {
 276
 277                 if (ooo_cmdsn->cid != conn->cid)
 278                         continue;
 279
 280                 dropped_count++;
 281                 pr_debug("Dropping unacknowledged CmdSN:"
 282                 " 0x%08x during connection recovery on CID: %hu\n",
 283                         ooo_cmdsn->cmdsn, conn->cid);
 284                 iscsit_remove_ooo_cmdsn(sess, ooo_cmdsn);
 285         }
 286         mutex_unlock(&sess->cmdsn_mutex);
 287
 288         spin_lock_bh(&conn->cmd_lock);
 289         list_for_each_entry_safe(cmd, cmd_tmp, &conn->conn_cmd_list, i_conn_node) {
 290                 if (!(cmd->cmd_flags & ICF_OOO_CMDSN))
 291                         continue;
 292
 293                 list_del_init(&cmd->i_conn_node);
 294
 295                 spin_unlock_bh(&conn->cmd_lock);
 296                 iscsit_free_cmd(cmd, true);
 297                 spin_lock_bh(&conn->cmd_lock);
 298         }
 299         spin_unlock_bh(&conn->cmd_lock);
 300
 301         pr_debug("Dropped %u total unacknowledged commands on CID:"
 302                 " %hu for ExpCmdSN: 0x%08x.\n", dropped_count, conn->cid,
 303                                 sess->exp_cmd_sn);
 304         return 0;
 305 }
 306
 307 int iscsit_prepare_cmds_for_reallegiance(struct iscsi_conn *conn)
 308 {
 309         u32 cmd_count = 0;
 310         struct iscsi_cmd *cmd, *cmd_tmp;
 311         struct iscsi_conn_recovery *cr;
 312
 313         /*
 314          * Allocate an struct iscsi_conn_recovery for this connection.
 315          * Each struct iscsi_cmd contains an struct iscsi_conn_recovery pointer
 316          * (struct iscsi_cmd->cr) so we need to allocate this before preparing the
 317          * connection's command list for connection recovery.
 318          */
 319         cr = kzalloc(sizeof(struct iscsi_conn_recovery), GFP_KERNEL);
 320         if (!cr) {
 321                 pr_err("Unable to allocate memory for"
 322                         " struct iscsi_conn_recovery.\n");
 323                 return -1;
 324         }
 325         INIT_LIST_HEAD(&cr->cr_list);
 326         INIT_LIST_HEAD(&cr->conn_recovery_cmd_list);
 327         spin_lock_init(&cr->conn_recovery_cmd_lock);
 328         /*
 329          * Only perform connection recovery on ISCSI_OP_SCSI_CMD or
 330          * ISCSI_OP_NOOP_OUT opcodes.  For all other opcodes call
 331          * list_del_init(&cmd->i_conn_node); to release the command to the
 332          * session pool and remove it from the connection's list.
 333          *
 334          * Also stop the DataOUT timer, which will be restarted after
 335          * sending the TMR response.
 336          */
 337         spin_lock_bh(&conn->cmd_lock);
 338         list_for_each_entry_safe(cmd, cmd_tmp, &conn->conn_cmd_list, i_conn_node) {
 339
 340                 if ((cmd->iscsi_opcode != ISCSI_OP_SCSI_CMD) &&
 341                     (cmd->iscsi_opcode != ISCSI_OP_NOOP_OUT)) {
 342                         pr_debug("Not performing reallegiance on"
 343                                 " Opcode: 0x%02x, ITT: 0x%08x, CmdSN: 0x%08x,"
 344                                 " CID: %hu\n", cmd->iscsi_opcode,
 345                                 cmd->init_task_tag, cmd->cmd_sn, conn->cid);
 346
 347                         list_del_init(&cmd->i_conn_node);
 348                         spin_unlock_bh(&conn->cmd_lock);
 349                         iscsit_free_cmd(cmd, true);
 350                         spin_lock_bh(&conn->cmd_lock);
 351                         continue;
 352                 }
 353
 354                 /*
 355                  * Special case where commands greater than or equal to
 356                  * the session's ExpCmdSN are attached to the connection
 357                  * list but not to the out of order CmdSN list.  The one
 358                  * obvious case is when a command with immediate data
 359                  * attached must only check the CmdSN against ExpCmdSN
 360                  * after the data is received.  The special case below
 361                  * is when the connection fails before data is received,
 362                  * but also may apply to other PDUs, so it has been
 363                  * made generic here.
 364                  */
 365                 if (!(cmd->cmd_flags & ICF_OOO_CMDSN) && !cmd->immediate_cmd &&
 366                      iscsi_sna_gte(cmd->cmd_sn, conn->sess->exp_cmd_sn)) {
 367                         list_del_init(&cmd->i_conn_node);
 368                         spin_unlock_bh(&conn->cmd_lock);
 369                         iscsit_free_cmd(cmd, true);
 370                         spin_lock_bh(&conn->cmd_lock);
 371                         continue;
 372                 }
 373
 374                 cmd_count++;
 375                 pr_debug("Preparing Opcode: 0x%02x, ITT: 0x%08x,"
 376                         " CmdSN: 0x%08x, StatSN: 0x%08x, CID: %hu for"
 377                         " reallegiance.\n", cmd->iscsi_opcode,
 378                         cmd->init_task_tag, cmd->cmd_sn, cmd->stat_sn,
 379                         conn->cid);
 380
 381                 cmd->deferred_i_state = cmd->i_state;
 382                 cmd->i_state = ISTATE_IN_CONNECTION_RECOVERY;
 383
 384                 if (cmd->data_direction == DMA_TO_DEVICE)
 385                         iscsit_stop_dataout_timer(cmd);
 386
 387                 cmd->sess = conn->sess;
 388
 389                 list_del_init(&cmd->i_conn_node);
 390                 spin_unlock_bh(&conn->cmd_lock);
 391
 392                 iscsit_free_all_datain_reqs(cmd);
 393
 394                 transport_wait_for_tasks(&cmd->se_cmd);
 395                 /*
 396                  * Add the struct iscsi_cmd to the connection recovery cmd list
 397                  */
 398                 spin_lock(&cr->conn_recovery_cmd_lock);
 399                 list_add_tail(&cmd->i_conn_node, &cr->conn_recovery_cmd_list);
 400                 spin_unlock(&cr->conn_recovery_cmd_lock);
 401
 402                 spin_lock_bh(&conn->cmd_lock);
 403                 cmd->cr = cr;
 404                 cmd->conn = NULL;
 405         }
 406         spin_unlock_bh(&conn->cmd_lock);
 407         /*
 408          * Fill in the various values in the preallocated struct iscsi_conn_recovery.
 409          */
 410         cr->cid = conn->cid;
 411         cr->cmd_count = cmd_count;
 412         cr->maxrecvdatasegmentlength = conn->conn_ops->MaxRecvDataSegmentLength;
 413         cr->maxxmitdatasegmentlength = conn->conn_ops->MaxXmitDataSegmentLength;
 414         cr->sess = conn->sess;
 415
 416         iscsit_attach_inactive_connection_recovery_entry(conn->sess, cr);
 417
 418         return 0;
 419 }
 420
 421 int iscsit_connection_recovery_transport_reset(struct iscsi_conn *conn)
 422 {
 423         atomic_set(&conn->connection_recovery, 1);
 424
 425         if (iscsit_close_connection(conn) < 0)
 426                 return -1;
 427
 428         return 0;
 429 }