1/******************************************************************************* 2 * This file contains the iSCSI Target specific Task Management functions. 3 * 4 * \u00a9 Copyright 2007-2011 RisingTide Systems LLC. 5 * 6 * Licensed to the Linux Foundation under the General Public License (GPL) version 2. 7 * 8 * Author: Nicholas A. Bellinger <nab@linux-iscsi.org> 9 * 10 * This program is free software; you can redistribute it and/or modify 11 * it under the terms of the GNU General Public License as published by 12 * the Free Software Foundation; either version 2 of the License, or 13 * (at your option) any later version. 14 * 15 * This program is distributed in the hope that it will be useful, 16 * but WITHOUT ANY WARRANTY; without even the implied warranty of 17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 18 * GNU General Public License for more details. 19 ******************************************************************************/ 20 21#include <asm/unaligned.h> 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_seq_pdu_list.h" 28#include "iscsi_target_datain_values.h" 29#include "iscsi_target_device.h" 30#include "iscsi_target_erl0.h" 31#include "iscsi_target_erl1.h" 32#include "iscsi_target_erl2.h" 33#include "iscsi_target_tmr.h" 34#include "iscsi_target_tpg.h" 35#include "iscsi_target_util.h" 36#include "iscsi_target.h" 37 38u8 iscsit_tmr_abort_task( 39 struct iscsi_cmd *cmd, 40 unsigned char *buf) 41{ 42 struct iscsi_cmd *ref_cmd; 43 struct iscsi_conn *conn = cmd->conn; 44 struct iscsi_tmr_req *tmr_req = cmd->tmr_req; 45 struct se_tmr_req *se_tmr = cmd->se_cmd.se_tmr_req; 46 struct iscsi_tm *hdr = (struct iscsi_tm *) buf; 47 48 ref_cmd = iscsit_find_cmd_from_itt(conn, hdr->rtt); 49 if (!ref_cmd) { 50 pr_err("Unable to locate RefTaskTag: 0x%08x on CID:" 51 " %hu.\n", hdr->rtt, conn->cid); 52 return ((hdr->refcmdsn >= conn->sess->exp_cmd_sn) && 53 (hdr->refcmdsn <= conn->sess->max_cmd_sn)) ? 54 ISCSI_TMF_RSP_COMPLETE : ISCSI_TMF_RSP_NO_TASK; 55 } 56 if (ref_cmd->cmd_sn != hdr->refcmdsn) { 57 pr_err("RefCmdSN 0x%08x does not equal" 58 " task's CmdSN 0x%08x. Rejecting ABORT_TASK.\n", 59 hdr->refcmdsn, ref_cmd->cmd_sn); 60 return ISCSI_TMF_RSP_REJECTED; 61 } 62 63 se_tmr->ref_task_tag = hdr->rtt; 64 se_tmr->ref_cmd = &ref_cmd->se_cmd; 65 tmr_req->ref_cmd_sn = hdr->refcmdsn; 66 tmr_req->exp_data_sn = hdr->exp_datasn; 67 68 return ISCSI_TMF_RSP_COMPLETE; 69} 70 71/* 72 * Called from iscsit_handle_task_mgt_cmd(). 73 */ 74int iscsit_tmr_task_warm_reset( 75 struct iscsi_conn *conn, 76 struct iscsi_tmr_req *tmr_req, 77 unsigned char *buf) 78{ 79 struct iscsi_session *sess = conn->sess; 80 struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess); 81#if 0 82 struct iscsi_init_task_mgt_cmnd *hdr = 83 (struct iscsi_init_task_mgt_cmnd *) buf; 84#endif 85 if (!na->tmr_warm_reset) { 86 pr_err("TMR Opcode TARGET_WARM_RESET authorization" 87 " failed for Initiator Node: %s\n", 88 sess->se_sess->se_node_acl->initiatorname); 89 return -1; 90 } 91 /* 92 * Do the real work in transport_generic_do_tmr(). 93 */ 94 return 0; 95} 96 97int iscsit_tmr_task_cold_reset( 98 struct iscsi_conn *conn, 99 struct iscsi_tmr_req *tmr_req, 100 unsigned char *buf) 101{ 102 struct iscsi_session *sess = conn->sess; 103 struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess); 104 105 if (!na->tmr_cold_reset) { 106 pr_err("TMR Opcode TARGET_COLD_RESET authorization" 107 " failed for Initiator Node: %s\n", 108 sess->se_sess->se_node_acl->initiatorname); 109 return -1; 110 } 111 /* 112 * Do the real work in transport_generic_do_tmr(). 113 */ 114 return 0; 115} 116 117u8 iscsit_tmr_task_reassign( 118 struct iscsi_cmd *cmd, 119 unsigned char *buf) 120{ 121 struct iscsi_cmd *ref_cmd = NULL; 122 struct iscsi_conn *conn = cmd->conn; 123 struct iscsi_conn_recovery *cr = NULL; 124 struct iscsi_tmr_req *tmr_req = cmd->tmr_req; 125 struct se_tmr_req *se_tmr = cmd->se_cmd.se_tmr_req; 126 struct iscsi_tm *hdr = (struct iscsi_tm *) buf; 127 int ret; 128 129 pr_debug("Got TASK_REASSIGN TMR ITT: 0x%08x," 130 " RefTaskTag: 0x%08x, ExpDataSN: 0x%08x, CID: %hu\n", 131 hdr->itt, hdr->rtt, hdr->exp_datasn, conn->cid); 132 133 if (conn->sess->sess_ops->ErrorRecoveryLevel != 2) { 134 pr_err("TMR TASK_REASSIGN not supported in ERL<2," 135 " ignoring request.\n"); 136 return ISCSI_TMF_RSP_NOT_SUPPORTED; 137 } 138 139 ret = iscsit_find_cmd_for_recovery(conn->sess, &ref_cmd, &cr, hdr->rtt); 140 if (ret == -2) { 141 pr_err("Command ITT: 0x%08x is still alligent to CID:" 142 " %hu\n", ref_cmd->init_task_tag, cr->cid); 143 return ISCSI_TMF_RSP_TASK_ALLEGIANT; 144 } else if (ret == -1) { 145 pr_err("Unable to locate RefTaskTag: 0x%08x in" 146 " connection recovery command list.\n", hdr->rtt); 147 return ISCSI_TMF_RSP_NO_TASK; 148 } 149 /* 150 * Temporary check to prevent connection recovery for 151 * connections with a differing MaxRecvDataSegmentLength. 152 */ 153 if (cr->maxrecvdatasegmentlength != 154 conn->conn_ops->MaxRecvDataSegmentLength) { 155 pr_err("Unable to perform connection recovery for" 156 " differing MaxRecvDataSegmentLength, rejecting" 157 " TMR TASK_REASSIGN.\n"); 158 return ISCSI_TMF_RSP_REJECTED; 159 } 160 161 se_tmr->ref_task_tag = hdr->rtt; 162 se_tmr->ref_cmd = &ref_cmd->se_cmd; 163 se_tmr->ref_task_lun = get_unaligned_le64(&hdr->lun); 164 tmr_req->ref_cmd_sn = hdr->refcmdsn; 165 tmr_req->exp_data_sn = hdr->exp_datasn; 166 tmr_req->conn_recovery = cr; 167 tmr_req->task_reassign = 1; 168 /* 169 * Command can now be reassigned to a new connection. 170 * The task management response must be sent before the 171 * reassignment actually happens. See iscsi_tmr_post_handler(). 172 */ 173 return ISCSI_TMF_RSP_COMPLETE; 174} 175 176static void iscsit_task_reassign_remove_cmd( 177 struct iscsi_cmd *cmd, 178 struct iscsi_conn_recovery *cr, 179 struct iscsi_session *sess) 180{ 181 int ret; 182 183 spin_lock(&cr->conn_recovery_cmd_lock); 184 ret = iscsit_remove_cmd_from_connection_recovery(cmd, sess); 185 spin_unlock(&cr->conn_recovery_cmd_lock); 186 if (!ret) { 187 pr_debug("iSCSI connection recovery successful for CID:" 188 " %hu on SID: %u\n", cr->cid, sess->sid); 189 iscsit_remove_active_connection_recovery_entry(cr, sess); 190 } 191} 192 193static int iscsit_task_reassign_complete_nop_out( 194 struct iscsi_tmr_req *tmr_req, 195 struct iscsi_conn *conn) 196{ 197 struct se_tmr_req *se_tmr = tmr_req->se_tmr_req; 198 struct se_cmd *se_cmd = se_tmr->ref_cmd; 199 struct iscsi_cmd *cmd = container_of(se_cmd, struct iscsi_cmd, se_cmd); 200 struct iscsi_conn_recovery *cr; 201 202 if (!cmd->cr) { 203 pr_err("struct iscsi_conn_recovery pointer for ITT: 0x%08x" 204 " is NULL!\n", cmd->init_task_tag); 205 return -1; 206 } 207 cr = cmd->cr; 208 209 /* 210 * Reset the StatSN so a new one for this commands new connection 211 * will be assigned. 212 * Reset the ExpStatSN as well so we may receive Status SNACKs. 213 */ 214 cmd->stat_sn = cmd->exp_stat_sn = 0; 215 216 iscsit_task_reassign_remove_cmd(cmd, cr, conn->sess); 217 218 spin_lock_bh(&conn->cmd_lock); 219 list_add_tail(&cmd->i_list, &conn->conn_cmd_list); 220 spin_unlock_bh(&conn->cmd_lock); 221 222 cmd->i_state = ISTATE_SEND_NOPIN; 223 iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state); 224 return 0; 225} 226 227static int iscsit_task_reassign_complete_write( 228 struct iscsi_cmd *cmd, 229 struct iscsi_tmr_req *tmr_req) 230{ 231 int no_build_r2ts = 0; 232 u32 length = 0, offset = 0; 233 struct iscsi_conn *conn = cmd->conn; 234 struct se_cmd *se_cmd = &cmd->se_cmd; 235 /* 236 * The Initiator must not send a R2T SNACK with a Begrun less than 237 * the TMR TASK_REASSIGN's ExpDataSN. 238 */ 239 if (!tmr_req->exp_data_sn) { 240 cmd->cmd_flags &= ~ICF_GOT_DATACK_SNACK; 241 cmd->acked_data_sn = 0; 242 } else { 243 cmd->cmd_flags |= ICF_GOT_DATACK_SNACK; 244 cmd->acked_data_sn = (tmr_req->exp_data_sn - 1); 245 } 246 247 /* 248 * The TMR TASK_REASSIGN's ExpDataSN contains the next R2TSN the 249 * Initiator is expecting. The Target controls all WRITE operations 250 * so if we have received all DataOUT we can safety ignore Initiator. 251 */ 252 if (cmd->cmd_flags & ICF_GOT_LAST_DATAOUT) { 253 if (!(cmd->se_cmd.transport_state & CMD_T_SENT)) { 254 pr_debug("WRITE ITT: 0x%08x: t_state: %d" 255 " never sent to transport\n", 256 cmd->init_task_tag, cmd->se_cmd.t_state); 257 return transport_generic_handle_data(se_cmd); 258 } 259 260 cmd->i_state = ISTATE_SEND_STATUS; 261 iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state); 262 return 0; 263 } 264 265 /* 266 * Special case to deal with DataSequenceInOrder=No and Non-Immeidate 267 * Unsolicited DataOut. 268 */ 269 if (cmd->unsolicited_data) { 270 cmd->unsolicited_data = 0; 271 272 offset = cmd->next_burst_len = cmd->write_data_done; 273 274 if ((conn->sess->sess_ops->FirstBurstLength - offset) >= 275 cmd->data_length) { 276 no_build_r2ts = 1; 277 length = (cmd->data_length - offset); 278 } else 279 length = (conn->sess->sess_ops->FirstBurstLength - offset); 280 281 spin_lock_bh(&cmd->r2t_lock); 282 if (iscsit_add_r2t_to_list(cmd, offset, length, 0, 0) < 0) { 283 spin_unlock_bh(&cmd->r2t_lock); 284 return -1; 285 } 286 cmd->outstanding_r2ts++; 287 spin_unlock_bh(&cmd->r2t_lock); 288 289 if (no_build_r2ts) 290 return 0; 291 } 292 /* 293 * iscsit_build_r2ts_for_cmd() can handle the rest from here. 294 */ 295 return iscsit_build_r2ts_for_cmd(cmd, conn, 2); 296} 297 298static int iscsit_task_reassign_complete_read( 299 struct iscsi_cmd *cmd, 300 struct iscsi_tmr_req *tmr_req) 301{ 302 struct iscsi_conn *conn = cmd->conn; 303 struct iscsi_datain_req *dr; 304 struct se_cmd *se_cmd = &cmd->se_cmd; 305 /* 306 * The Initiator must not send a Data SNACK with a BegRun less than 307 * the TMR TASK_REASSIGN's ExpDataSN. 308 */ 309 if (!tmr_req->exp_data_sn) { 310 cmd->cmd_flags &= ~ICF_GOT_DATACK_SNACK; 311 cmd->acked_data_sn = 0; 312 } else { 313 cmd->cmd_flags |= ICF_GOT_DATACK_SNACK; 314 cmd->acked_data_sn = (tmr_req->exp_data_sn - 1); 315 } 316 317 if (!(cmd->se_cmd.transport_state & CMD_T_SENT)) { 318 pr_debug("READ ITT: 0x%08x: t_state: %d never sent to" 319 " transport\n", cmd->init_task_tag, 320 cmd->se_cmd.t_state); 321 transport_handle_cdb_direct(se_cmd); 322 return 0; 323 } 324 325 if (!(se_cmd->transport_state & CMD_T_COMPLETE)) { 326 pr_err("READ ITT: 0x%08x: t_state: %d, never returned" 327 " from transport\n", cmd->init_task_tag, 328 cmd->se_cmd.t_state); 329 return -1; 330 } 331 332 dr = iscsit_allocate_datain_req(); 333 if (!dr) 334 return -1; 335 /* 336 * The TMR TASK_REASSIGN's ExpDataSN contains the next DataSN the 337 * Initiator is expecting. 338 */ 339 dr->data_sn = dr->begrun = tmr_req->exp_data_sn; 340 dr->runlength = 0; 341 dr->generate_recovery_values = 1; 342 dr->recovery = DATAIN_CONNECTION_RECOVERY; 343 344 iscsit_attach_datain_req(cmd, dr); 345 346 cmd->i_state = ISTATE_SEND_DATAIN; 347 iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state); 348 return 0; 349} 350 351static int iscsit_task_reassign_complete_none( 352 struct iscsi_cmd *cmd, 353 struct iscsi_tmr_req *tmr_req) 354{ 355 struct iscsi_conn *conn = cmd->conn; 356 357 cmd->i_state = ISTATE_SEND_STATUS; 358 iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state); 359 return 0; 360} 361 362static int iscsit_task_reassign_complete_scsi_cmnd( 363 struct iscsi_tmr_req *tmr_req, 364 struct iscsi_conn *conn) 365{ 366 struct se_tmr_req *se_tmr = tmr_req->se_tmr_req; 367 struct se_cmd *se_cmd = se_tmr->ref_cmd; 368 struct iscsi_cmd *cmd = container_of(se_cmd, struct iscsi_cmd, se_cmd); 369 struct iscsi_conn_recovery *cr; 370 371 if (!cmd->cr) { 372 pr_err("struct iscsi_conn_recovery pointer for ITT: 0x%08x" 373 " is NULL!\n", cmd->init_task_tag); 374 return -1; 375 } 376 cr = cmd->cr; 377 378 /* 379 * Reset the StatSN so a new one for this commands new connection 380 * will be assigned. 381 * Reset the ExpStatSN as well so we may receive Status SNACKs. 382 */ 383 cmd->stat_sn = cmd->exp_stat_sn = 0; 384 385 iscsit_task_reassign_remove_cmd(cmd, cr, conn->sess); 386 387 spin_lock_bh(&conn->cmd_lock); 388 list_add_tail(&cmd->i_list, &conn->conn_cmd_list); 389 spin_unlock_bh(&conn->cmd_lock); 390 391 if (se_cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION) { 392 cmd->i_state = ISTATE_SEND_STATUS; 393 iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state); 394 return 0; 395 } 396 397 switch (cmd->data_direction) { 398 case DMA_TO_DEVICE: 399 return iscsit_task_reassign_complete_write(cmd, tmr_req); 400 case DMA_FROM_DEVICE: 401 return iscsit_task_reassign_complete_read(cmd, tmr_req); 402 case DMA_NONE: 403 return iscsit_task_reassign_complete_none(cmd, tmr_req); 404 default: 405 pr_err("Unknown cmd->data_direction: 0x%02x\n", 406 cmd->data_direction); 407 return -1; 408 } 409 410 return 0; 411} 412 413static int iscsit_task_reassign_complete( 414 struct iscsi_tmr_req *tmr_req, 415 struct iscsi_conn *conn) 416{ 417 struct se_tmr_req *se_tmr = tmr_req->se_tmr_req; 418 struct se_cmd *se_cmd; 419 struct iscsi_cmd *cmd; 420 int ret = 0; 421 422 if (!se_tmr->ref_cmd) { 423 pr_err("TMR Request is missing a RefCmd struct iscsi_cmd.\n"); 424 return -1; 425 } 426 se_cmd = se_tmr->ref_cmd; 427 cmd = container_of(se_cmd, struct iscsi_cmd, se_cmd); 428 429 cmd->conn = conn; 430 431 switch (cmd->iscsi_opcode) { 432 case ISCSI_OP_NOOP_OUT: 433 ret = iscsit_task_reassign_complete_nop_out(tmr_req, conn); 434 break; 435 case ISCSI_OP_SCSI_CMD: 436 ret = iscsit_task_reassign_complete_scsi_cmnd(tmr_req, conn); 437 break; 438 default: 439 pr_err("Illegal iSCSI Opcode 0x%02x during" 440 " command realligence\n", cmd->iscsi_opcode); 441 return -1; 442 } 443 444 if (ret != 0) 445 return ret; 446 447 pr_debug("Completed connection realligence for Opcode: 0x%02x," 448 " ITT: 0x%08x to CID: %hu.\n", cmd->iscsi_opcode, 449 cmd->init_task_tag, conn->cid); 450 451 return 0; 452} 453 454/* 455 * Handles special after-the-fact actions related to TMRs. 456 * Right now the only one that its really needed for is 457 * connection recovery releated TASK_REASSIGN. 458 */ 459extern int iscsit_tmr_post_handler(struct iscsi_cmd *cmd, struct iscsi_conn *conn) 460{ 461 struct iscsi_tmr_req *tmr_req = cmd->tmr_req; 462 struct se_tmr_req *se_tmr = cmd->se_cmd.se_tmr_req; 463 464 if (tmr_req->task_reassign && 465 (se_tmr->response == ISCSI_TMF_RSP_COMPLETE)) 466 return iscsit_task_reassign_complete(tmr_req, conn); 467 468 return 0; 469} 470 471/* 472 * Nothing to do here, but leave it for good measure. :-) 473 */ 474int iscsit_task_reassign_prepare_read( 475 struct iscsi_tmr_req *tmr_req, 476 struct iscsi_conn *conn) 477{ 478 return 0; 479} 480 481static void iscsit_task_reassign_prepare_unsolicited_dataout( 482 struct iscsi_cmd *cmd, 483 struct iscsi_conn *conn) 484{ 485 int i, j; 486 struct iscsi_pdu *pdu = NULL; 487 struct iscsi_seq *seq = NULL; 488 489 if (conn->sess->sess_ops->DataSequenceInOrder) { 490 cmd->data_sn = 0; 491 492 if (cmd->immediate_data) 493 cmd->r2t_offset += (cmd->first_burst_len - 494 cmd->seq_start_offset); 495 496 if (conn->sess->sess_ops->DataPDUInOrder) { 497 cmd->write_data_done -= (cmd->immediate_data) ? 498 (cmd->first_burst_len - 499 cmd->seq_start_offset) : 500 cmd->first_burst_len; 501 cmd->first_burst_len = 0; 502 return; 503 } 504 505 for (i = 0; i < cmd->pdu_count; i++) { 506 pdu = &cmd->pdu_list[i]; 507 508 if (pdu->status != ISCSI_PDU_RECEIVED_OK) 509 continue; 510 511 if ((pdu->offset >= cmd->seq_start_offset) && 512 ((pdu->offset + pdu->length) <= 513 cmd->seq_end_offset)) { 514 cmd->first_burst_len -= pdu->length; 515 cmd->write_data_done -= pdu->length; 516 pdu->status = ISCSI_PDU_NOT_RECEIVED; 517 } 518 } 519 } else { 520 for (i = 0; i < cmd->seq_count; i++) { 521 seq = &cmd->seq_list[i]; 522 523 if (seq->type != SEQTYPE_UNSOLICITED) 524 continue; 525 526 cmd->write_data_done -= 527 (seq->offset - seq->orig_offset); 528 cmd->first_burst_len = 0; 529 seq->data_sn = 0; 530 seq->offset = seq->orig_offset; 531 seq->next_burst_len = 0; 532 seq->status = DATAOUT_SEQUENCE_WITHIN_COMMAND_RECOVERY; 533 534 if (conn->sess->sess_ops->DataPDUInOrder) 535 continue; 536 537 for (j = 0; j < seq->pdu_count; j++) { 538 pdu = &cmd->pdu_list[j+seq->pdu_start]; 539 540 if (pdu->status != ISCSI_PDU_RECEIVED_OK) 541 continue; 542 543 pdu->status = ISCSI_PDU_NOT_RECEIVED; 544 } 545 } 546 } 547} 548 549int iscsit_task_reassign_prepare_write( 550 struct iscsi_tmr_req *tmr_req, 551 struct iscsi_conn *conn) 552{ 553 struct se_tmr_req *se_tmr = tmr_req->se_tmr_req; 554 struct se_cmd *se_cmd = se_tmr->ref_cmd; 555 struct iscsi_cmd *cmd = container_of(se_cmd, struct iscsi_cmd, se_cmd); 556 struct iscsi_pdu *pdu = NULL; 557 struct iscsi_r2t *r2t = NULL, *r2t_tmp; 558 int first_incomplete_r2t = 1, i = 0; 559 560 /* 561 * The command was in the process of receiving Unsolicited DataOUT when 562 * the connection failed. 563 */ 564 if (cmd->unsolicited_data) 565 iscsit_task_reassign_prepare_unsolicited_dataout(cmd, conn); 566 567 /* 568 * The Initiator is requesting R2Ts starting from zero, skip 569 * checking acknowledged R2Ts and start checking struct iscsi_r2ts 570 * greater than zero. 571 */ 572 if (!tmr_req->exp_data_sn) 573 goto drop_unacknowledged_r2ts; 574 575 /* 576 * We now check that the PDUs in DataOUT sequences below 577 * the TMR TASK_REASSIGN ExpDataSN (R2TSN the Initiator is 578 * expecting next) have all the DataOUT they require to complete 579 * the DataOUT sequence. First scan from R2TSN 0 to TMR 580 * TASK_REASSIGN ExpDataSN-1. 581 * 582 * If we have not received all DataOUT in question, we must 583 * make sure to make the appropriate changes to values in 584 * struct iscsi_cmd (and elsewhere depending on session parameters) 585 * so iscsit_build_r2ts_for_cmd() in iscsit_task_reassign_complete_write() 586 * will resend a new R2T for the DataOUT sequences in question. 587 */ 588 spin_lock_bh(&cmd->r2t_lock); 589 if (list_empty(&cmd->cmd_r2t_list)) { 590 spin_unlock_bh(&cmd->r2t_lock); 591 return -1; 592 } 593 594 list_for_each_entry(r2t, &cmd->cmd_r2t_list, r2t_list) { 595 596 if (r2t->r2t_sn >= tmr_req->exp_data_sn) 597 continue; 598 /* 599 * Safely ignore Recovery R2Ts and R2Ts that have completed 600 * DataOUT sequences. 601 */ 602 if (r2t->seq_complete) 603 continue; 604 605 if (r2t->recovery_r2t) 606 continue; 607 608 /* 609 * DataSequenceInOrder=Yes: 610 * 611 * Taking into account the iSCSI implementation requirement of 612 * MaxOutstandingR2T=1 while ErrorRecoveryLevel>0 and 613 * DataSequenceInOrder=Yes, we must take into consideration 614 * the following: 615 * 616 * DataSequenceInOrder=No: 617 * 618 * Taking into account that the Initiator controls the (possibly 619 * random) PDU Order in (possibly random) Sequence Order of 620 * DataOUT the target requests with R2Ts, we must take into 621 * consideration the following: 622 * 623 * DataPDUInOrder=Yes for DataSequenceInOrder=[Yes,No]: 624 * 625 * While processing non-complete R2T DataOUT sequence requests 626 * the Target will re-request only the total sequence length 627 * minus current received offset. This is because we must 628 * assume the initiator will continue sending DataOUT from the 629 * last PDU before the connection failed. 630 * 631 * DataPDUInOrder=No for DataSequenceInOrder=[Yes,No]: 632 * 633 * While processing non-complete R2T DataOUT sequence requests 634 * the Target will re-request the entire DataOUT sequence if 635 * any single PDU is missing from the sequence. This is because 636 * we have no logical method to determine the next PDU offset, 637 * and we must assume the Initiator will be sending any random 638 * PDU offset in the current sequence after TASK_REASSIGN 639 * has completed. 640 */ 641 if (conn->sess->sess_ops->DataSequenceInOrder) { 642 if (!first_incomplete_r2t) { 643 cmd->r2t_offset -= r2t->xfer_len; 644 goto next; 645 } 646 647 if (conn->sess->sess_ops->DataPDUInOrder) { 648 cmd->data_sn = 0; 649 cmd->r2t_offset -= (r2t->xfer_len - 650 cmd->next_burst_len); 651 first_incomplete_r2t = 0; 652 goto next; 653 } 654 655 cmd->data_sn = 0; 656 cmd->r2t_offset -= r2t->xfer_len; 657 658 for (i = 0; i < cmd->pdu_count; i++) { 659 pdu = &cmd->pdu_list[i]; 660 661 if (pdu->status != ISCSI_PDU_RECEIVED_OK) 662 continue; 663 664 if ((pdu->offset >= r2t->offset) && 665 (pdu->offset < (r2t->offset + 666 r2t->xfer_len))) { 667 cmd->next_burst_len -= pdu->length; 668 cmd->write_data_done -= pdu->length; 669 pdu->status = ISCSI_PDU_NOT_RECEIVED; 670 } 671 } 672 673 first_incomplete_r2t = 0; 674 } else { 675 struct iscsi_seq *seq; 676 677 seq = iscsit_get_seq_holder(cmd, r2t->offset, 678 r2t->xfer_len); 679 if (!seq) { 680 spin_unlock_bh(&cmd->r2t_lock); 681 return -1; 682 } 683 684 cmd->write_data_done -= 685 (seq->offset - seq->orig_offset); 686 seq->data_sn = 0; 687 seq->offset = seq->orig_offset; 688 seq->next_burst_len = 0; 689 seq->status = DATAOUT_SEQUENCE_WITHIN_COMMAND_RECOVERY; 690 691 cmd->seq_send_order--; 692 693 if (conn->sess->sess_ops->DataPDUInOrder) 694 goto next; 695 696 for (i = 0; i < seq->pdu_count; i++) { 697 pdu = &cmd->pdu_list[i+seq->pdu_start]; 698 699 if (pdu->status != ISCSI_PDU_RECEIVED_OK) 700 continue; 701 702 pdu->status = ISCSI_PDU_NOT_RECEIVED; 703 } 704 } 705 706next: 707 cmd->outstanding_r2ts--; 708 } 709 spin_unlock_bh(&cmd->r2t_lock); 710 711 /* 712 * We now drop all unacknowledged R2Ts, ie: ExpDataSN from TMR 713 * TASK_REASSIGN to the last R2T in the list.. We are also careful 714 * to check that the Initiator is not requesting R2Ts for DataOUT 715 * sequences it has already completed. 716 * 717 * Free each R2T in question and adjust values in struct iscsi_cmd 718 * accordingly so iscsit_build_r2ts_for_cmd() do the rest of 719 * the work after the TMR TASK_REASSIGN Response is sent. 720 */ 721drop_unacknowledged_r2ts: 722 723 cmd->cmd_flags &= ~ICF_SENT_LAST_R2T; 724 cmd->r2t_sn = tmr_req->exp_data_sn; 725 726 spin_lock_bh(&cmd->r2t_lock); 727 list_for_each_entry_safe(r2t, r2t_tmp, &cmd->cmd_r2t_list, r2t_list) { 728 /* 729 * Skip up to the R2T Sequence number provided by the 730 * iSCSI TASK_REASSIGN TMR 731 */ 732 if (r2t->r2t_sn < tmr_req->exp_data_sn) 733 continue; 734 735 if (r2t->seq_complete) { 736 pr_err("Initiator is requesting R2Ts from" 737 " R2TSN: 0x%08x, but R2TSN: 0x%08x, Offset: %u," 738 " Length: %u is already complete." 739 " BAD INITIATOR ERL=2 IMPLEMENTATION!\n", 740 tmr_req->exp_data_sn, r2t->r2t_sn, 741 r2t->offset, r2t->xfer_len); 742 spin_unlock_bh(&cmd->r2t_lock); 743 return -1; 744 } 745 746 if (r2t->recovery_r2t) { 747 iscsit_free_r2t(r2t, cmd); 748 continue; 749 } 750 751 /* DataSequenceInOrder=Yes: 752 * 753 * Taking into account the iSCSI implementation requirement of 754 * MaxOutstandingR2T=1 while ErrorRecoveryLevel>0 and 755 * DataSequenceInOrder=Yes, it's safe to subtract the R2Ts 756 * entire transfer length from the commands R2T offset marker. 757 * 758 * DataSequenceInOrder=No: 759 * 760 * We subtract the difference from struct iscsi_seq between the 761 * current offset and original offset from cmd->write_data_done 762 * for account for DataOUT PDUs already received. Then reset 763 * the current offset to the original and zero out the current 764 * burst length, to make sure we re-request the entire DataOUT 765 * sequence. 766 */ 767 if (conn->sess->sess_ops->DataSequenceInOrder) 768 cmd->r2t_offset -= r2t->xfer_len; 769 else 770 cmd->seq_send_order--; 771 772 cmd->outstanding_r2ts--; 773 iscsit_free_r2t(r2t, cmd); 774 } 775 spin_unlock_bh(&cmd->r2t_lock); 776 777 return 0; 778} 779 780/* 781 * Performs sanity checks TMR TASK_REASSIGN's ExpDataSN for 782 * a given struct iscsi_cmd. 783 */ 784int iscsit_check_task_reassign_expdatasn( 785 struct iscsi_tmr_req *tmr_req, 786 struct iscsi_conn *conn) 787{ 788 struct se_tmr_req *se_tmr = tmr_req->se_tmr_req; 789 struct se_cmd *se_cmd = se_tmr->ref_cmd; 790 struct iscsi_cmd *ref_cmd = container_of(se_cmd, struct iscsi_cmd, se_cmd); 791 792 if (ref_cmd->iscsi_opcode != ISCSI_OP_SCSI_CMD) 793 return 0; 794 795 if (se_cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION) 796 return 0; 797 798 if (ref_cmd->data_direction == DMA_NONE) 799 return 0; 800 801 /* 802 * For READs the TMR TASK_REASSIGNs ExpDataSN contains the next DataSN 803 * of DataIN the Initiator is expecting. 804 * 805 * Also check that the Initiator is not re-requesting DataIN that has 806 * already been acknowledged with a DataAck SNACK. 807 */ 808 if (ref_cmd->data_direction == DMA_FROM_DEVICE) { 809 if (tmr_req->exp_data_sn > ref_cmd->data_sn) { 810 pr_err("Received ExpDataSN: 0x%08x for READ" 811 " in TMR TASK_REASSIGN greater than command's" 812 " DataSN: 0x%08x.\n", tmr_req->exp_data_sn, 813 ref_cmd->data_sn); 814 return -1; 815 } 816 if ((ref_cmd->cmd_flags & ICF_GOT_DATACK_SNACK) && 817 (tmr_req->exp_data_sn <= ref_cmd->acked_data_sn)) { 818 pr_err("Received ExpDataSN: 0x%08x for READ" 819 " in TMR TASK_REASSIGN for previously" 820 " acknowledged DataIN: 0x%08x," 821 " protocol error\n", tmr_req->exp_data_sn, 822 ref_cmd->acked_data_sn); 823 return -1; 824 } 825 return iscsit_task_reassign_prepare_read(tmr_req, conn); 826 } 827 828 /* 829 * For WRITEs the TMR TASK_REASSIGNs ExpDataSN contains the next R2TSN 830 * for R2Ts the Initiator is expecting. 831 * 832 * Do the magic in iscsit_task_reassign_prepare_write(). 833 */ 834 if (ref_cmd->data_direction == DMA_TO_DEVICE) { 835 if (tmr_req->exp_data_sn > ref_cmd->r2t_sn) { 836 pr_err("Received ExpDataSN: 0x%08x for WRITE" 837 " in TMR TASK_REASSIGN greater than command's" 838 " R2TSN: 0x%08x.\n", tmr_req->exp_data_sn, 839 ref_cmd->r2t_sn); 840 return -1; 841 } 842 return iscsit_task_reassign_prepare_write(tmr_req, conn); 843 } 844 845 pr_err("Unknown iSCSI data_direction: 0x%02x\n", 846 ref_cmd->data_direction); 847 848 return -1; 849} 850