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 u32 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 (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 int 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 return 0; 205 } 206 207 /* 208 * Called with cr->conn_recovery_cmd_lock help. 209 */ 210 int iscsit_remove_cmd_from_connection_recovery( 211 struct iscsi_cmd *cmd, 212 struct iscsi_session *sess) 213 { 214 struct iscsi_conn_recovery *cr; 215 216 if (!cmd->cr) { 217 pr_err("struct iscsi_conn_recovery pointer for ITT: 0x%08x" 218 " is NULL!\n", cmd->init_task_tag); 219 BUG(); 220 } 221 cr = cmd->cr; 222 223 list_del(&cmd->i_conn_node); 224 return --cr->cmd_count; 225 } 226 227 void iscsit_discard_cr_cmds_by_expstatsn( 228 struct iscsi_conn_recovery *cr, 229 u32 exp_statsn) 230 { 231 u32 dropped_count = 0; 232 struct iscsi_cmd *cmd, *cmd_tmp; 233 struct iscsi_session *sess = cr->sess; 234 235 spin_lock(&cr->conn_recovery_cmd_lock); 236 list_for_each_entry_safe(cmd, cmd_tmp, 237 &cr->conn_recovery_cmd_list, i_conn_node) { 238 239 if (((cmd->deferred_i_state != ISTATE_SENT_STATUS) && 240 (cmd->deferred_i_state != ISTATE_REMOVE)) || 241 (cmd->stat_sn >= exp_statsn)) { 242 continue; 243 } 244 245 dropped_count++; 246 pr_debug("Dropping Acknowledged ITT: 0x%08x, StatSN:" 247 " 0x%08x, CID: %hu.\n", cmd->init_task_tag, 248 cmd->stat_sn, cr->cid); 249 250 iscsit_remove_cmd_from_connection_recovery(cmd, sess); 251 252 spin_unlock(&cr->conn_recovery_cmd_lock); 253 iscsit_free_cmd(cmd); 254 spin_lock(&cr->conn_recovery_cmd_lock); 255 } 256 spin_unlock(&cr->conn_recovery_cmd_lock); 257 258 pr_debug("Dropped %u total acknowledged commands on" 259 " CID: %hu less than old ExpStatSN: 0x%08x\n", 260 dropped_count, cr->cid, exp_statsn); 261 262 if (!cr->cmd_count) { 263 pr_debug("No commands to be reassigned for failed" 264 " connection CID: %hu on SID: %u\n", 265 cr->cid, sess->sid); 266 iscsit_remove_inactive_connection_recovery_entry(cr, sess); 267 iscsit_attach_active_connection_recovery_entry(sess, cr); 268 pr_debug("iSCSI connection recovery successful for CID:" 269 " %hu on SID: %u\n", cr->cid, sess->sid); 270 iscsit_remove_active_connection_recovery_entry(cr, sess); 271 } else { 272 iscsit_remove_inactive_connection_recovery_entry(cr, sess); 273 iscsit_attach_active_connection_recovery_entry(sess, cr); 274 } 275 } 276 277 int iscsit_discard_unacknowledged_ooo_cmdsns_for_conn(struct iscsi_conn *conn) 278 { 279 u32 dropped_count = 0; 280 struct iscsi_cmd *cmd, *cmd_tmp; 281 struct iscsi_ooo_cmdsn *ooo_cmdsn, *ooo_cmdsn_tmp; 282 struct iscsi_session *sess = conn->sess; 283 284 mutex_lock(&sess->cmdsn_mutex); 285 list_for_each_entry_safe(ooo_cmdsn, ooo_cmdsn_tmp, 286 &sess->sess_ooo_cmdsn_list, ooo_list) { 287 288 if (ooo_cmdsn->cid != conn->cid) 289 continue; 290 291 dropped_count++; 292 pr_debug("Dropping unacknowledged CmdSN:" 293 " 0x%08x during connection recovery on CID: %hu\n", 294 ooo_cmdsn->cmdsn, conn->cid); 295 iscsit_remove_ooo_cmdsn(sess, ooo_cmdsn); 296 } 297 mutex_unlock(&sess->cmdsn_mutex); 298 299 spin_lock_bh(&conn->cmd_lock); 300 list_for_each_entry_safe(cmd, cmd_tmp, &conn->conn_cmd_list, i_conn_node) { 301 if (!(cmd->cmd_flags & ICF_OOO_CMDSN)) 302 continue; 303 304 list_del(&cmd->i_conn_node); 305 306 spin_unlock_bh(&conn->cmd_lock); 307 iscsit_free_cmd(cmd); 308 spin_lock_bh(&conn->cmd_lock); 309 } 310 spin_unlock_bh(&conn->cmd_lock); 311 312 pr_debug("Dropped %u total unacknowledged commands on CID:" 313 " %hu for ExpCmdSN: 0x%08x.\n", dropped_count, conn->cid, 314 sess->exp_cmd_sn); 315 return 0; 316 } 317 318 int iscsit_prepare_cmds_for_realligance(struct iscsi_conn *conn) 319 { 320 u32 cmd_count = 0; 321 struct iscsi_cmd *cmd, *cmd_tmp; 322 struct iscsi_conn_recovery *cr; 323 324 /* 325 * Allocate an struct iscsi_conn_recovery for this connection. 326 * Each struct iscsi_cmd contains an struct iscsi_conn_recovery pointer 327 * (struct iscsi_cmd->cr) so we need to allocate this before preparing the 328 * connection's command list for connection recovery. 329 */ 330 cr = kzalloc(sizeof(struct iscsi_conn_recovery), GFP_KERNEL); 331 if (!cr) { 332 pr_err("Unable to allocate memory for" 333 " struct iscsi_conn_recovery.\n"); 334 return -1; 335 } 336 INIT_LIST_HEAD(&cr->cr_list); 337 INIT_LIST_HEAD(&cr->conn_recovery_cmd_list); 338 spin_lock_init(&cr->conn_recovery_cmd_lock); 339 /* 340 * Only perform connection recovery on ISCSI_OP_SCSI_CMD or 341 * ISCSI_OP_NOOP_OUT opcodes. For all other opcodes call 342 * list_del(&cmd->i_conn_node); to release the command to the 343 * session pool and remove it from the connection's list. 344 * 345 * Also stop the DataOUT timer, which will be restarted after 346 * sending the TMR response. 347 */ 348 spin_lock_bh(&conn->cmd_lock); 349 list_for_each_entry_safe(cmd, cmd_tmp, &conn->conn_cmd_list, i_conn_node) { 350 351 if ((cmd->iscsi_opcode != ISCSI_OP_SCSI_CMD) && 352 (cmd->iscsi_opcode != ISCSI_OP_NOOP_OUT)) { 353 pr_debug("Not performing realligence on" 354 " Opcode: 0x%02x, ITT: 0x%08x, CmdSN: 0x%08x," 355 " CID: %hu\n", cmd->iscsi_opcode, 356 cmd->init_task_tag, cmd->cmd_sn, conn->cid); 357 358 list_del(&cmd->i_conn_node); 359 spin_unlock_bh(&conn->cmd_lock); 360 iscsit_free_cmd(cmd); 361 spin_lock_bh(&conn->cmd_lock); 362 continue; 363 } 364 365 /* 366 * Special case where commands greater than or equal to 367 * the session's ExpCmdSN are attached to the connection 368 * list but not to the out of order CmdSN list. The one 369 * obvious case is when a command with immediate data 370 * attached must only check the CmdSN against ExpCmdSN 371 * after the data is received. The special case below 372 * is when the connection fails before data is received, 373 * but also may apply to other PDUs, so it has been 374 * made generic here. 375 */ 376 if (!(cmd->cmd_flags & ICF_OOO_CMDSN) && !cmd->immediate_cmd && 377 (cmd->cmd_sn >= conn->sess->exp_cmd_sn)) { 378 list_del(&cmd->i_conn_node); 379 spin_unlock_bh(&conn->cmd_lock); 380 iscsit_free_cmd(cmd); 381 spin_lock_bh(&conn->cmd_lock); 382 continue; 383 } 384 385 cmd_count++; 386 pr_debug("Preparing Opcode: 0x%02x, ITT: 0x%08x," 387 " CmdSN: 0x%08x, StatSN: 0x%08x, CID: %hu for" 388 " realligence.\n", cmd->iscsi_opcode, 389 cmd->init_task_tag, cmd->cmd_sn, cmd->stat_sn, 390 conn->cid); 391 392 cmd->deferred_i_state = cmd->i_state; 393 cmd->i_state = ISTATE_IN_CONNECTION_RECOVERY; 394 395 if (cmd->data_direction == DMA_TO_DEVICE) 396 iscsit_stop_dataout_timer(cmd); 397 398 cmd->sess = conn->sess; 399 400 list_del(&cmd->i_conn_node); 401 spin_unlock_bh(&conn->cmd_lock); 402 403 iscsit_free_all_datain_reqs(cmd); 404 405 transport_wait_for_tasks(&cmd->se_cmd); 406 /* 407 * Add the struct iscsi_cmd to the connection recovery cmd list 408 */ 409 spin_lock(&cr->conn_recovery_cmd_lock); 410 list_add_tail(&cmd->i_conn_node, &cr->conn_recovery_cmd_list); 411 spin_unlock(&cr->conn_recovery_cmd_lock); 412 413 spin_lock_bh(&conn->cmd_lock); 414 cmd->cr = cr; 415 cmd->conn = NULL; 416 } 417 spin_unlock_bh(&conn->cmd_lock); 418 /* 419 * Fill in the various values in the preallocated struct iscsi_conn_recovery. 420 */ 421 cr->cid = conn->cid; 422 cr->cmd_count = cmd_count; 423 cr->maxrecvdatasegmentlength = conn->conn_ops->MaxRecvDataSegmentLength; 424 cr->sess = conn->sess; 425 426 iscsit_attach_inactive_connection_recovery_entry(conn->sess, cr); 427 428 return 0; 429 } 430 431 int iscsit_connection_recovery_transport_reset(struct iscsi_conn *conn) 432 { 433 atomic_set(&conn->connection_recovery, 1); 434 435 if (iscsit_close_connection(conn) < 0) 436 return -1; 437 438 return 0; 439 } 440