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/scsi_device.h> 23 #include <scsi/iscsi_proto.h> 24 #include <target/target_core_base.h> 25 #include <target/target_core_fabric.h> 26 27 #include "iscsi_target_core.h" 28 #include "iscsi_target_seq_pdu_list.h" 29 #include "iscsi_target_datain_values.h" 30 #include "iscsi_target_device.h" 31 #include "iscsi_target_erl0.h" 32 #include "iscsi_target_erl1.h" 33 #include "iscsi_target_erl2.h" 34 #include "iscsi_target_tmr.h" 35 #include "iscsi_target_tpg.h" 36 #include "iscsi_target_util.h" 37 #include "iscsi_target.h" 38 39 u8 iscsit_tmr_abort_task( 40 struct iscsi_cmd *cmd, 41 unsigned char *buf) 42 { 43 struct iscsi_cmd *ref_cmd; 44 struct iscsi_conn *conn = cmd->conn; 45 struct iscsi_tmr_req *tmr_req = cmd->tmr_req; 46 struct se_tmr_req *se_tmr = cmd->se_cmd.se_tmr_req; 47 struct iscsi_tm *hdr = (struct iscsi_tm *) buf; 48 49 ref_cmd = iscsit_find_cmd_from_itt(conn, hdr->rtt); 50 if (!ref_cmd) { 51 pr_err("Unable to locate RefTaskTag: 0x%08x on CID:" 52 " %hu.\n", hdr->rtt, conn->cid); 53 return ((hdr->refcmdsn >= conn->sess->exp_cmd_sn) && 54 (hdr->refcmdsn <= conn->sess->max_cmd_sn)) ? 55 ISCSI_TMF_RSP_COMPLETE : ISCSI_TMF_RSP_NO_TASK; 56 } 57 if (ref_cmd->cmd_sn != hdr->refcmdsn) { 58 pr_err("RefCmdSN 0x%08x does not equal" 59 " task's CmdSN 0x%08x. Rejecting ABORT_TASK.\n", 60 hdr->refcmdsn, ref_cmd->cmd_sn); 61 return ISCSI_TMF_RSP_REJECTED; 62 } 63 64 se_tmr->ref_task_tag = hdr->rtt; 65 tmr_req->ref_cmd = ref_cmd; 66 tmr_req->ref_cmd_sn = hdr->refcmdsn; 67 tmr_req->exp_data_sn = hdr->exp_datasn; 68 69 return ISCSI_TMF_RSP_COMPLETE; 70 } 71 72 /* 73 * Called from iscsit_handle_task_mgt_cmd(). 74 */ 75 int iscsit_tmr_task_warm_reset( 76 struct iscsi_conn *conn, 77 struct iscsi_tmr_req *tmr_req, 78 unsigned char *buf) 79 { 80 struct iscsi_session *sess = conn->sess; 81 struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess); 82 83 if (!na->tmr_warm_reset) { 84 pr_err("TMR Opcode TARGET_WARM_RESET authorization" 85 " failed for Initiator Node: %s\n", 86 sess->se_sess->se_node_acl->initiatorname); 87 return -1; 88 } 89 /* 90 * Do the real work in transport_generic_do_tmr(). 91 */ 92 return 0; 93 } 94 95 int iscsit_tmr_task_cold_reset( 96 struct iscsi_conn *conn, 97 struct iscsi_tmr_req *tmr_req, 98 unsigned char *buf) 99 { 100 struct iscsi_session *sess = conn->sess; 101 struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess); 102 103 if (!na->tmr_cold_reset) { 104 pr_err("TMR Opcode TARGET_COLD_RESET authorization" 105 " failed for Initiator Node: %s\n", 106 sess->se_sess->se_node_acl->initiatorname); 107 return -1; 108 } 109 /* 110 * Do the real work in transport_generic_do_tmr(). 111 */ 112 return 0; 113 } 114 115 u8 iscsit_tmr_task_reassign( 116 struct iscsi_cmd *cmd, 117 unsigned char *buf) 118 { 119 struct iscsi_cmd *ref_cmd = NULL; 120 struct iscsi_conn *conn = cmd->conn; 121 struct iscsi_conn_recovery *cr = NULL; 122 struct iscsi_tmr_req *tmr_req = cmd->tmr_req; 123 struct se_tmr_req *se_tmr = cmd->se_cmd.se_tmr_req; 124 struct iscsi_tm *hdr = (struct iscsi_tm *) buf; 125 int ret, ref_lun; 126 127 pr_debug("Got TASK_REASSIGN TMR ITT: 0x%08x," 128 " RefTaskTag: 0x%08x, ExpDataSN: 0x%08x, CID: %hu\n", 129 hdr->itt, hdr->rtt, hdr->exp_datasn, conn->cid); 130 131 if (conn->sess->sess_ops->ErrorRecoveryLevel != 2) { 132 pr_err("TMR TASK_REASSIGN not supported in ERL<2," 133 " ignoring request.\n"); 134 return ISCSI_TMF_RSP_NOT_SUPPORTED; 135 } 136 137 ret = iscsit_find_cmd_for_recovery(conn->sess, &ref_cmd, &cr, hdr->rtt); 138 if (ret == -2) { 139 pr_err("Command ITT: 0x%08x is still alligent to CID:" 140 " %hu\n", ref_cmd->init_task_tag, cr->cid); 141 return ISCSI_TMF_RSP_TASK_ALLEGIANT; 142 } else if (ret == -1) { 143 pr_err("Unable to locate RefTaskTag: 0x%08x in" 144 " connection recovery command list.\n", hdr->rtt); 145 return ISCSI_TMF_RSP_NO_TASK; 146 } 147 /* 148 * Temporary check to prevent connection recovery for 149 * connections with a differing MaxRecvDataSegmentLength. 150 */ 151 if (cr->maxrecvdatasegmentlength != 152 conn->conn_ops->MaxRecvDataSegmentLength) { 153 pr_err("Unable to perform connection recovery for" 154 " differing MaxRecvDataSegmentLength, rejecting" 155 " TMR TASK_REASSIGN.\n"); 156 return ISCSI_TMF_RSP_REJECTED; 157 } 158 159 ref_lun = scsilun_to_int(&hdr->lun); 160 if (ref_lun != ref_cmd->se_cmd.orig_fe_lun) { 161 pr_err("Unable to perform connection recovery for" 162 " differing ref_lun: %d ref_cmd orig_fe_lun: %u\n", 163 ref_lun, ref_cmd->se_cmd.orig_fe_lun); 164 return ISCSI_TMF_RSP_REJECTED; 165 } 166 167 se_tmr->ref_task_tag = hdr->rtt; 168 tmr_req->ref_cmd = ref_cmd; 169 tmr_req->ref_cmd_sn = hdr->refcmdsn; 170 tmr_req->exp_data_sn = hdr->exp_datasn; 171 tmr_req->conn_recovery = cr; 172 tmr_req->task_reassign = 1; 173 /* 174 * Command can now be reassigned to a new connection. 175 * The task management response must be sent before the 176 * reassignment actually happens. See iscsi_tmr_post_handler(). 177 */ 178 return ISCSI_TMF_RSP_COMPLETE; 179 } 180 181 static void iscsit_task_reassign_remove_cmd( 182 struct iscsi_cmd *cmd, 183 struct iscsi_conn_recovery *cr, 184 struct iscsi_session *sess) 185 { 186 int ret; 187 188 spin_lock(&cr->conn_recovery_cmd_lock); 189 ret = iscsit_remove_cmd_from_connection_recovery(cmd, sess); 190 spin_unlock(&cr->conn_recovery_cmd_lock); 191 if (!ret) { 192 pr_debug("iSCSI connection recovery successful for CID:" 193 " %hu on SID: %u\n", cr->cid, sess->sid); 194 iscsit_remove_active_connection_recovery_entry(cr, sess); 195 } 196 } 197 198 static int iscsit_task_reassign_complete_nop_out( 199 struct iscsi_tmr_req *tmr_req, 200 struct iscsi_conn *conn) 201 { 202 struct iscsi_cmd *cmd = tmr_req->ref_cmd; 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 return -1; 209 } 210 cr = cmd->cr; 211 212 /* 213 * Reset the StatSN so a new one for this commands new connection 214 * will be assigned. 215 * Reset the ExpStatSN as well so we may receive Status SNACKs. 216 */ 217 cmd->stat_sn = cmd->exp_stat_sn = 0; 218 219 iscsit_task_reassign_remove_cmd(cmd, cr, conn->sess); 220 221 spin_lock_bh(&conn->cmd_lock); 222 list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list); 223 spin_unlock_bh(&conn->cmd_lock); 224 225 cmd->i_state = ISTATE_SEND_NOPIN; 226 iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state); 227 return 0; 228 } 229 230 static int iscsit_task_reassign_complete_write( 231 struct iscsi_cmd *cmd, 232 struct iscsi_tmr_req *tmr_req) 233 { 234 int no_build_r2ts = 0; 235 u32 length = 0, offset = 0; 236 struct iscsi_conn *conn = cmd->conn; 237 struct se_cmd *se_cmd = &cmd->se_cmd; 238 /* 239 * The Initiator must not send a R2T SNACK with a Begrun less than 240 * the TMR TASK_REASSIGN's ExpDataSN. 241 */ 242 if (!tmr_req->exp_data_sn) { 243 cmd->cmd_flags &= ~ICF_GOT_DATACK_SNACK; 244 cmd->acked_data_sn = 0; 245 } else { 246 cmd->cmd_flags |= ICF_GOT_DATACK_SNACK; 247 cmd->acked_data_sn = (tmr_req->exp_data_sn - 1); 248 } 249 250 /* 251 * The TMR TASK_REASSIGN's ExpDataSN contains the next R2TSN the 252 * Initiator is expecting. The Target controls all WRITE operations 253 * so if we have received all DataOUT we can safety ignore Initiator. 254 */ 255 if (cmd->cmd_flags & ICF_GOT_LAST_DATAOUT) { 256 if (!(cmd->se_cmd.transport_state & CMD_T_SENT)) { 257 pr_debug("WRITE ITT: 0x%08x: t_state: %d" 258 " never sent to transport\n", 259 cmd->init_task_tag, cmd->se_cmd.t_state); 260 target_execute_cmd(se_cmd); 261 return 0; 262 } 263 264 cmd->i_state = ISTATE_SEND_STATUS; 265 iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state); 266 return 0; 267 } 268 269 /* 270 * Special case to deal with DataSequenceInOrder=No and Non-Immeidate 271 * Unsolicited DataOut. 272 */ 273 if (cmd->unsolicited_data) { 274 cmd->unsolicited_data = 0; 275 276 offset = cmd->next_burst_len = cmd->write_data_done; 277 278 if ((conn->sess->sess_ops->FirstBurstLength - offset) >= 279 cmd->se_cmd.data_length) { 280 no_build_r2ts = 1; 281 length = (cmd->se_cmd.data_length - offset); 282 } else 283 length = (conn->sess->sess_ops->FirstBurstLength - offset); 284 285 spin_lock_bh(&cmd->r2t_lock); 286 if (iscsit_add_r2t_to_list(cmd, offset, length, 0, 0) < 0) { 287 spin_unlock_bh(&cmd->r2t_lock); 288 return -1; 289 } 290 cmd->outstanding_r2ts++; 291 spin_unlock_bh(&cmd->r2t_lock); 292 293 if (no_build_r2ts) 294 return 0; 295 } 296 /* 297 * iscsit_build_r2ts_for_cmd() can handle the rest from here. 298 */ 299 return iscsit_build_r2ts_for_cmd(cmd, conn, true); 300 } 301 302 static int iscsit_task_reassign_complete_read( 303 struct iscsi_cmd *cmd, 304 struct iscsi_tmr_req *tmr_req) 305 { 306 struct iscsi_conn *conn = cmd->conn; 307 struct iscsi_datain_req *dr; 308 struct se_cmd *se_cmd = &cmd->se_cmd; 309 /* 310 * The Initiator must not send a Data SNACK with a BegRun less than 311 * the TMR TASK_REASSIGN's ExpDataSN. 312 */ 313 if (!tmr_req->exp_data_sn) { 314 cmd->cmd_flags &= ~ICF_GOT_DATACK_SNACK; 315 cmd->acked_data_sn = 0; 316 } else { 317 cmd->cmd_flags |= ICF_GOT_DATACK_SNACK; 318 cmd->acked_data_sn = (tmr_req->exp_data_sn - 1); 319 } 320 321 if (!(cmd->se_cmd.transport_state & CMD_T_SENT)) { 322 pr_debug("READ ITT: 0x%08x: t_state: %d never sent to" 323 " transport\n", cmd->init_task_tag, 324 cmd->se_cmd.t_state); 325 transport_handle_cdb_direct(se_cmd); 326 return 0; 327 } 328 329 if (!(se_cmd->transport_state & CMD_T_COMPLETE)) { 330 pr_err("READ ITT: 0x%08x: t_state: %d, never returned" 331 " from transport\n", cmd->init_task_tag, 332 cmd->se_cmd.t_state); 333 return -1; 334 } 335 336 dr = iscsit_allocate_datain_req(); 337 if (!dr) 338 return -1; 339 /* 340 * The TMR TASK_REASSIGN's ExpDataSN contains the next DataSN the 341 * Initiator is expecting. 342 */ 343 dr->data_sn = dr->begrun = tmr_req->exp_data_sn; 344 dr->runlength = 0; 345 dr->generate_recovery_values = 1; 346 dr->recovery = DATAIN_CONNECTION_RECOVERY; 347 348 iscsit_attach_datain_req(cmd, dr); 349 350 cmd->i_state = ISTATE_SEND_DATAIN; 351 iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state); 352 return 0; 353 } 354 355 static int iscsit_task_reassign_complete_none( 356 struct iscsi_cmd *cmd, 357 struct iscsi_tmr_req *tmr_req) 358 { 359 struct iscsi_conn *conn = cmd->conn; 360 361 cmd->i_state = ISTATE_SEND_STATUS; 362 iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state); 363 return 0; 364 } 365 366 static int iscsit_task_reassign_complete_scsi_cmnd( 367 struct iscsi_tmr_req *tmr_req, 368 struct iscsi_conn *conn) 369 { 370 struct iscsi_cmd *cmd = tmr_req->ref_cmd; 371 struct iscsi_conn_recovery *cr; 372 373 if (!cmd->cr) { 374 pr_err("struct iscsi_conn_recovery pointer for ITT: 0x%08x" 375 " is NULL!\n", cmd->init_task_tag); 376 return -1; 377 } 378 cr = cmd->cr; 379 380 /* 381 * Reset the StatSN so a new one for this commands new connection 382 * will be assigned. 383 * Reset the ExpStatSN as well so we may receive Status SNACKs. 384 */ 385 cmd->stat_sn = cmd->exp_stat_sn = 0; 386 387 iscsit_task_reassign_remove_cmd(cmd, cr, conn->sess); 388 389 spin_lock_bh(&conn->cmd_lock); 390 list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list); 391 spin_unlock_bh(&conn->cmd_lock); 392 393 if (cmd->se_cmd.se_cmd_flags & SCF_SENT_CHECK_CONDITION) { 394 cmd->i_state = ISTATE_SEND_STATUS; 395 iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state); 396 return 0; 397 } 398 399 switch (cmd->data_direction) { 400 case DMA_TO_DEVICE: 401 return iscsit_task_reassign_complete_write(cmd, tmr_req); 402 case DMA_FROM_DEVICE: 403 return iscsit_task_reassign_complete_read(cmd, tmr_req); 404 case DMA_NONE: 405 return iscsit_task_reassign_complete_none(cmd, tmr_req); 406 default: 407 pr_err("Unknown cmd->data_direction: 0x%02x\n", 408 cmd->data_direction); 409 return -1; 410 } 411 412 return 0; 413 } 414 415 static int iscsit_task_reassign_complete( 416 struct iscsi_tmr_req *tmr_req, 417 struct iscsi_conn *conn) 418 { 419 struct iscsi_cmd *cmd; 420 int ret = 0; 421 422 if (!tmr_req->ref_cmd) { 423 pr_err("TMR Request is missing a RefCmd struct iscsi_cmd.\n"); 424 return -1; 425 } 426 cmd = tmr_req->ref_cmd; 427 428 cmd->conn = conn; 429 430 switch (cmd->iscsi_opcode) { 431 case ISCSI_OP_NOOP_OUT: 432 ret = iscsit_task_reassign_complete_nop_out(tmr_req, conn); 433 break; 434 case ISCSI_OP_SCSI_CMD: 435 ret = iscsit_task_reassign_complete_scsi_cmnd(tmr_req, conn); 436 break; 437 default: 438 pr_err("Illegal iSCSI Opcode 0x%02x during" 439 " command realligence\n", cmd->iscsi_opcode); 440 return -1; 441 } 442 443 if (ret != 0) 444 return ret; 445 446 pr_debug("Completed connection realligence for Opcode: 0x%02x," 447 " ITT: 0x%08x to CID: %hu.\n", cmd->iscsi_opcode, 448 cmd->init_task_tag, conn->cid); 449 450 return 0; 451 } 452 453 /* 454 * Handles special after-the-fact actions related to TMRs. 455 * Right now the only one that its really needed for is 456 * connection recovery releated TASK_REASSIGN. 457 */ 458 extern int iscsit_tmr_post_handler(struct iscsi_cmd *cmd, struct iscsi_conn *conn) 459 { 460 struct iscsi_tmr_req *tmr_req = cmd->tmr_req; 461 struct se_tmr_req *se_tmr = cmd->se_cmd.se_tmr_req; 462 463 if (tmr_req->task_reassign && 464 (se_tmr->response == ISCSI_TMF_RSP_COMPLETE)) 465 return iscsit_task_reassign_complete(tmr_req, conn); 466 467 return 0; 468 } 469 470 /* 471 * Nothing to do here, but leave it for good measure. :-) 472 */ 473 int iscsit_task_reassign_prepare_read( 474 struct iscsi_tmr_req *tmr_req, 475 struct iscsi_conn *conn) 476 { 477 return 0; 478 } 479 480 static void iscsit_task_reassign_prepare_unsolicited_dataout( 481 struct iscsi_cmd *cmd, 482 struct iscsi_conn *conn) 483 { 484 int i, j; 485 struct iscsi_pdu *pdu = NULL; 486 struct iscsi_seq *seq = NULL; 487 488 if (conn->sess->sess_ops->DataSequenceInOrder) { 489 cmd->data_sn = 0; 490 491 if (cmd->immediate_data) 492 cmd->r2t_offset += (cmd->first_burst_len - 493 cmd->seq_start_offset); 494 495 if (conn->sess->sess_ops->DataPDUInOrder) { 496 cmd->write_data_done -= (cmd->immediate_data) ? 497 (cmd->first_burst_len - 498 cmd->seq_start_offset) : 499 cmd->first_burst_len; 500 cmd->first_burst_len = 0; 501 return; 502 } 503 504 for (i = 0; i < cmd->pdu_count; i++) { 505 pdu = &cmd->pdu_list[i]; 506 507 if (pdu->status != ISCSI_PDU_RECEIVED_OK) 508 continue; 509 510 if ((pdu->offset >= cmd->seq_start_offset) && 511 ((pdu->offset + pdu->length) <= 512 cmd->seq_end_offset)) { 513 cmd->first_burst_len -= pdu->length; 514 cmd->write_data_done -= pdu->length; 515 pdu->status = ISCSI_PDU_NOT_RECEIVED; 516 } 517 } 518 } else { 519 for (i = 0; i < cmd->seq_count; i++) { 520 seq = &cmd->seq_list[i]; 521 522 if (seq->type != SEQTYPE_UNSOLICITED) 523 continue; 524 525 cmd->write_data_done -= 526 (seq->offset - seq->orig_offset); 527 cmd->first_burst_len = 0; 528 seq->data_sn = 0; 529 seq->offset = seq->orig_offset; 530 seq->next_burst_len = 0; 531 seq->status = DATAOUT_SEQUENCE_WITHIN_COMMAND_RECOVERY; 532 533 if (conn->sess->sess_ops->DataPDUInOrder) 534 continue; 535 536 for (j = 0; j < seq->pdu_count; j++) { 537 pdu = &cmd->pdu_list[j+seq->pdu_start]; 538 539 if (pdu->status != ISCSI_PDU_RECEIVED_OK) 540 continue; 541 542 pdu->status = ISCSI_PDU_NOT_RECEIVED; 543 } 544 } 545 } 546 } 547 548 int iscsit_task_reassign_prepare_write( 549 struct iscsi_tmr_req *tmr_req, 550 struct iscsi_conn *conn) 551 { 552 struct iscsi_cmd *cmd = tmr_req->ref_cmd; 553 struct iscsi_pdu *pdu = NULL; 554 struct iscsi_r2t *r2t = NULL, *r2t_tmp; 555 int first_incomplete_r2t = 1, i = 0; 556 557 /* 558 * The command was in the process of receiving Unsolicited DataOUT when 559 * the connection failed. 560 */ 561 if (cmd->unsolicited_data) 562 iscsit_task_reassign_prepare_unsolicited_dataout(cmd, conn); 563 564 /* 565 * The Initiator is requesting R2Ts starting from zero, skip 566 * checking acknowledged R2Ts and start checking struct iscsi_r2ts 567 * greater than zero. 568 */ 569 if (!tmr_req->exp_data_sn) 570 goto drop_unacknowledged_r2ts; 571 572 /* 573 * We now check that the PDUs in DataOUT sequences below 574 * the TMR TASK_REASSIGN ExpDataSN (R2TSN the Initiator is 575 * expecting next) have all the DataOUT they require to complete 576 * the DataOUT sequence. First scan from R2TSN 0 to TMR 577 * TASK_REASSIGN ExpDataSN-1. 578 * 579 * If we have not received all DataOUT in question, we must 580 * make sure to make the appropriate changes to values in 581 * struct iscsi_cmd (and elsewhere depending on session parameters) 582 * so iscsit_build_r2ts_for_cmd() in iscsit_task_reassign_complete_write() 583 * will resend a new R2T for the DataOUT sequences in question. 584 */ 585 spin_lock_bh(&cmd->r2t_lock); 586 if (list_empty(&cmd->cmd_r2t_list)) { 587 spin_unlock_bh(&cmd->r2t_lock); 588 return -1; 589 } 590 591 list_for_each_entry(r2t, &cmd->cmd_r2t_list, r2t_list) { 592 593 if (r2t->r2t_sn >= tmr_req->exp_data_sn) 594 continue; 595 /* 596 * Safely ignore Recovery R2Ts and R2Ts that have completed 597 * DataOUT sequences. 598 */ 599 if (r2t->seq_complete) 600 continue; 601 602 if (r2t->recovery_r2t) 603 continue; 604 605 /* 606 * DataSequenceInOrder=Yes: 607 * 608 * Taking into account the iSCSI implementation requirement of 609 * MaxOutstandingR2T=1 while ErrorRecoveryLevel>0 and 610 * DataSequenceInOrder=Yes, we must take into consideration 611 * the following: 612 * 613 * DataSequenceInOrder=No: 614 * 615 * Taking into account that the Initiator controls the (possibly 616 * random) PDU Order in (possibly random) Sequence Order of 617 * DataOUT the target requests with R2Ts, we must take into 618 * consideration the following: 619 * 620 * DataPDUInOrder=Yes for DataSequenceInOrder=[Yes,No]: 621 * 622 * While processing non-complete R2T DataOUT sequence requests 623 * the Target will re-request only the total sequence length 624 * minus current received offset. This is because we must 625 * assume the initiator will continue sending DataOUT from the 626 * last PDU before the connection failed. 627 * 628 * DataPDUInOrder=No for DataSequenceInOrder=[Yes,No]: 629 * 630 * While processing non-complete R2T DataOUT sequence requests 631 * the Target will re-request the entire DataOUT sequence if 632 * any single PDU is missing from the sequence. This is because 633 * we have no logical method to determine the next PDU offset, 634 * and we must assume the Initiator will be sending any random 635 * PDU offset in the current sequence after TASK_REASSIGN 636 * has completed. 637 */ 638 if (conn->sess->sess_ops->DataSequenceInOrder) { 639 if (!first_incomplete_r2t) { 640 cmd->r2t_offset -= r2t->xfer_len; 641 goto next; 642 } 643 644 if (conn->sess->sess_ops->DataPDUInOrder) { 645 cmd->data_sn = 0; 646 cmd->r2t_offset -= (r2t->xfer_len - 647 cmd->next_burst_len); 648 first_incomplete_r2t = 0; 649 goto next; 650 } 651 652 cmd->data_sn = 0; 653 cmd->r2t_offset -= r2t->xfer_len; 654 655 for (i = 0; i < cmd->pdu_count; i++) { 656 pdu = &cmd->pdu_list[i]; 657 658 if (pdu->status != ISCSI_PDU_RECEIVED_OK) 659 continue; 660 661 if ((pdu->offset >= r2t->offset) && 662 (pdu->offset < (r2t->offset + 663 r2t->xfer_len))) { 664 cmd->next_burst_len -= pdu->length; 665 cmd->write_data_done -= pdu->length; 666 pdu->status = ISCSI_PDU_NOT_RECEIVED; 667 } 668 } 669 670 first_incomplete_r2t = 0; 671 } else { 672 struct iscsi_seq *seq; 673 674 seq = iscsit_get_seq_holder(cmd, r2t->offset, 675 r2t->xfer_len); 676 if (!seq) { 677 spin_unlock_bh(&cmd->r2t_lock); 678 return -1; 679 } 680 681 cmd->write_data_done -= 682 (seq->offset - seq->orig_offset); 683 seq->data_sn = 0; 684 seq->offset = seq->orig_offset; 685 seq->next_burst_len = 0; 686 seq->status = DATAOUT_SEQUENCE_WITHIN_COMMAND_RECOVERY; 687 688 cmd->seq_send_order--; 689 690 if (conn->sess->sess_ops->DataPDUInOrder) 691 goto next; 692 693 for (i = 0; i < seq->pdu_count; i++) { 694 pdu = &cmd->pdu_list[i+seq->pdu_start]; 695 696 if (pdu->status != ISCSI_PDU_RECEIVED_OK) 697 continue; 698 699 pdu->status = ISCSI_PDU_NOT_RECEIVED; 700 } 701 } 702 703 next: 704 cmd->outstanding_r2ts--; 705 } 706 spin_unlock_bh(&cmd->r2t_lock); 707 708 /* 709 * We now drop all unacknowledged R2Ts, ie: ExpDataSN from TMR 710 * TASK_REASSIGN to the last R2T in the list.. We are also careful 711 * to check that the Initiator is not requesting R2Ts for DataOUT 712 * sequences it has already completed. 713 * 714 * Free each R2T in question and adjust values in struct iscsi_cmd 715 * accordingly so iscsit_build_r2ts_for_cmd() do the rest of 716 * the work after the TMR TASK_REASSIGN Response is sent. 717 */ 718 drop_unacknowledged_r2ts: 719 720 cmd->cmd_flags &= ~ICF_SENT_LAST_R2T; 721 cmd->r2t_sn = tmr_req->exp_data_sn; 722 723 spin_lock_bh(&cmd->r2t_lock); 724 list_for_each_entry_safe(r2t, r2t_tmp, &cmd->cmd_r2t_list, r2t_list) { 725 /* 726 * Skip up to the R2T Sequence number provided by the 727 * iSCSI TASK_REASSIGN TMR 728 */ 729 if (r2t->r2t_sn < tmr_req->exp_data_sn) 730 continue; 731 732 if (r2t->seq_complete) { 733 pr_err("Initiator is requesting R2Ts from" 734 " R2TSN: 0x%08x, but R2TSN: 0x%08x, Offset: %u," 735 " Length: %u is already complete." 736 " BAD INITIATOR ERL=2 IMPLEMENTATION!\n", 737 tmr_req->exp_data_sn, r2t->r2t_sn, 738 r2t->offset, r2t->xfer_len); 739 spin_unlock_bh(&cmd->r2t_lock); 740 return -1; 741 } 742 743 if (r2t->recovery_r2t) { 744 iscsit_free_r2t(r2t, cmd); 745 continue; 746 } 747 748 /* DataSequenceInOrder=Yes: 749 * 750 * Taking into account the iSCSI implementation requirement of 751 * MaxOutstandingR2T=1 while ErrorRecoveryLevel>0 and 752 * DataSequenceInOrder=Yes, it's safe to subtract the R2Ts 753 * entire transfer length from the commands R2T offset marker. 754 * 755 * DataSequenceInOrder=No: 756 * 757 * We subtract the difference from struct iscsi_seq between the 758 * current offset and original offset from cmd->write_data_done 759 * for account for DataOUT PDUs already received. Then reset 760 * the current offset to the original and zero out the current 761 * burst length, to make sure we re-request the entire DataOUT 762 * sequence. 763 */ 764 if (conn->sess->sess_ops->DataSequenceInOrder) 765 cmd->r2t_offset -= r2t->xfer_len; 766 else 767 cmd->seq_send_order--; 768 769 cmd->outstanding_r2ts--; 770 iscsit_free_r2t(r2t, cmd); 771 } 772 spin_unlock_bh(&cmd->r2t_lock); 773 774 return 0; 775 } 776 777 /* 778 * Performs sanity checks TMR TASK_REASSIGN's ExpDataSN for 779 * a given struct iscsi_cmd. 780 */ 781 int iscsit_check_task_reassign_expdatasn( 782 struct iscsi_tmr_req *tmr_req, 783 struct iscsi_conn *conn) 784 { 785 struct iscsi_cmd *ref_cmd = tmr_req->ref_cmd; 786 787 if (ref_cmd->iscsi_opcode != ISCSI_OP_SCSI_CMD) 788 return 0; 789 790 if (ref_cmd->se_cmd.se_cmd_flags & SCF_SENT_CHECK_CONDITION) 791 return 0; 792 793 if (ref_cmd->data_direction == DMA_NONE) 794 return 0; 795 796 /* 797 * For READs the TMR TASK_REASSIGNs ExpDataSN contains the next DataSN 798 * of DataIN the Initiator is expecting. 799 * 800 * Also check that the Initiator is not re-requesting DataIN that has 801 * already been acknowledged with a DataAck SNACK. 802 */ 803 if (ref_cmd->data_direction == DMA_FROM_DEVICE) { 804 if (tmr_req->exp_data_sn > ref_cmd->data_sn) { 805 pr_err("Received ExpDataSN: 0x%08x for READ" 806 " in TMR TASK_REASSIGN greater than command's" 807 " DataSN: 0x%08x.\n", tmr_req->exp_data_sn, 808 ref_cmd->data_sn); 809 return -1; 810 } 811 if ((ref_cmd->cmd_flags & ICF_GOT_DATACK_SNACK) && 812 (tmr_req->exp_data_sn <= ref_cmd->acked_data_sn)) { 813 pr_err("Received ExpDataSN: 0x%08x for READ" 814 " in TMR TASK_REASSIGN for previously" 815 " acknowledged DataIN: 0x%08x," 816 " protocol error\n", tmr_req->exp_data_sn, 817 ref_cmd->acked_data_sn); 818 return -1; 819 } 820 return iscsit_task_reassign_prepare_read(tmr_req, conn); 821 } 822 823 /* 824 * For WRITEs the TMR TASK_REASSIGNs ExpDataSN contains the next R2TSN 825 * for R2Ts the Initiator is expecting. 826 * 827 * Do the magic in iscsit_task_reassign_prepare_write(). 828 */ 829 if (ref_cmd->data_direction == DMA_TO_DEVICE) { 830 if (tmr_req->exp_data_sn > ref_cmd->r2t_sn) { 831 pr_err("Received ExpDataSN: 0x%08x for WRITE" 832 " in TMR TASK_REASSIGN greater than command's" 833 " R2TSN: 0x%08x.\n", tmr_req->exp_data_sn, 834 ref_cmd->r2t_sn); 835 return -1; 836 } 837 return iscsit_task_reassign_prepare_write(tmr_req, conn); 838 } 839 840 pr_err("Unknown iSCSI data_direction: 0x%02x\n", 841 ref_cmd->data_direction); 842 843 return -1; 844 } 845