1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /******************************************************************************* 3 * This file contains the iSCSI Target specific Task Management functions. 4 * 5 * (c) Copyright 2007-2013 Datera, Inc. 6 * 7 * Author: Nicholas A. Bellinger <nab@linux-iscsi.org> 8 * 9 ******************************************************************************/ 10 11 #include <linux/unaligned.h> 12 #include <scsi/scsi_proto.h> 13 #include <scsi/iscsi_proto.h> 14 #include <target/target_core_base.h> 15 #include <target/target_core_fabric.h> 16 #include <target/iscsi/iscsi_transport.h> 17 18 #include <target/iscsi/iscsi_target_core.h> 19 #include "iscsi_target_seq_pdu_list.h" 20 #include "iscsi_target_datain_values.h" 21 #include "iscsi_target_device.h" 22 #include "iscsi_target_erl0.h" 23 #include "iscsi_target_erl1.h" 24 #include "iscsi_target_erl2.h" 25 #include "iscsi_target_tmr.h" 26 #include "iscsi_target_tpg.h" 27 #include "iscsi_target_util.h" 28 #include "iscsi_target.h" 29 30 u8 iscsit_tmr_abort_task( 31 struct iscsit_cmd *cmd, 32 unsigned char *buf) 33 { 34 struct iscsit_cmd *ref_cmd; 35 struct iscsit_conn *conn = cmd->conn; 36 struct iscsi_tmr_req *tmr_req = cmd->tmr_req; 37 struct se_tmr_req *se_tmr = cmd->se_cmd.se_tmr_req; 38 struct iscsi_tm *hdr = (struct iscsi_tm *) buf; 39 40 ref_cmd = iscsit_find_cmd_from_itt(conn, hdr->rtt); 41 if (!ref_cmd) { 42 pr_err("Unable to locate RefTaskTag: 0x%08x on CID:" 43 " %hu.\n", hdr->rtt, conn->cid); 44 return (iscsi_sna_gte(be32_to_cpu(hdr->refcmdsn), conn->sess->exp_cmd_sn) && 45 iscsi_sna_lte(be32_to_cpu(hdr->refcmdsn), (u32) atomic_read(&conn->sess->max_cmd_sn))) ? 46 ISCSI_TMF_RSP_COMPLETE : ISCSI_TMF_RSP_NO_TASK; 47 } 48 if (ref_cmd->cmd_sn != be32_to_cpu(hdr->refcmdsn)) { 49 pr_err("RefCmdSN 0x%08x does not equal" 50 " task's CmdSN 0x%08x. Rejecting ABORT_TASK.\n", 51 hdr->refcmdsn, ref_cmd->cmd_sn); 52 return ISCSI_TMF_RSP_REJECTED; 53 } 54 55 se_tmr->ref_task_tag = (__force u32)hdr->rtt; 56 tmr_req->ref_cmd = ref_cmd; 57 tmr_req->exp_data_sn = be32_to_cpu(hdr->exp_datasn); 58 59 return ISCSI_TMF_RSP_COMPLETE; 60 } 61 62 /* 63 * Called from iscsit_handle_task_mgt_cmd(). 64 */ 65 int iscsit_tmr_task_warm_reset( 66 struct iscsit_conn *conn, 67 struct iscsi_tmr_req *tmr_req, 68 unsigned char *buf) 69 { 70 struct iscsit_session *sess = conn->sess; 71 struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess); 72 73 if (!na->tmr_warm_reset) { 74 pr_err("TMR Opcode TARGET_WARM_RESET authorization" 75 " failed for Initiator Node: %s\n", 76 sess->se_sess->se_node_acl->initiatorname); 77 return -1; 78 } 79 /* 80 * Do the real work in transport_generic_do_tmr(). 81 */ 82 return 0; 83 } 84 85 int iscsit_tmr_task_cold_reset( 86 struct iscsit_conn *conn, 87 struct iscsi_tmr_req *tmr_req, 88 unsigned char *buf) 89 { 90 struct iscsit_session *sess = conn->sess; 91 struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess); 92 93 if (!na->tmr_cold_reset) { 94 pr_err("TMR Opcode TARGET_COLD_RESET authorization" 95 " failed for Initiator Node: %s\n", 96 sess->se_sess->se_node_acl->initiatorname); 97 return -1; 98 } 99 /* 100 * Do the real work in transport_generic_do_tmr(). 101 */ 102 return 0; 103 } 104 105 u8 iscsit_tmr_task_reassign( 106 struct iscsit_cmd *cmd, 107 unsigned char *buf) 108 { 109 struct iscsit_cmd *ref_cmd = NULL; 110 struct iscsit_conn *conn = cmd->conn; 111 struct iscsi_conn_recovery *cr = NULL; 112 struct iscsi_tmr_req *tmr_req = cmd->tmr_req; 113 struct se_tmr_req *se_tmr = cmd->se_cmd.se_tmr_req; 114 struct iscsi_tm *hdr = (struct iscsi_tm *) buf; 115 u64 ret, ref_lun; 116 117 pr_debug("Got TASK_REASSIGN TMR ITT: 0x%08x," 118 " RefTaskTag: 0x%08x, ExpDataSN: 0x%08x, CID: %hu\n", 119 hdr->itt, hdr->rtt, hdr->exp_datasn, conn->cid); 120 121 if (conn->sess->sess_ops->ErrorRecoveryLevel != 2) { 122 pr_err("TMR TASK_REASSIGN not supported in ERL<2," 123 " ignoring request.\n"); 124 return ISCSI_TMF_RSP_NOT_SUPPORTED; 125 } 126 127 ret = iscsit_find_cmd_for_recovery(conn->sess, &ref_cmd, &cr, hdr->rtt); 128 if (ret == -2) { 129 pr_err("Command ITT: 0x%08x is still alligent to CID:" 130 " %hu\n", ref_cmd->init_task_tag, cr->cid); 131 return ISCSI_TMF_RSP_TASK_ALLEGIANT; 132 } else if (ret == -1) { 133 pr_err("Unable to locate RefTaskTag: 0x%08x in" 134 " connection recovery command list.\n", hdr->rtt); 135 return ISCSI_TMF_RSP_NO_TASK; 136 } 137 /* 138 * Temporary check to prevent connection recovery for 139 * connections with a differing Max*DataSegmentLength. 140 */ 141 if (cr->maxrecvdatasegmentlength != 142 conn->conn_ops->MaxRecvDataSegmentLength) { 143 pr_err("Unable to perform connection recovery for" 144 " differing MaxRecvDataSegmentLength, rejecting" 145 " TMR TASK_REASSIGN.\n"); 146 return ISCSI_TMF_RSP_REJECTED; 147 } 148 if (cr->maxxmitdatasegmentlength != 149 conn->conn_ops->MaxXmitDataSegmentLength) { 150 pr_err("Unable to perform connection recovery for" 151 " differing MaxXmitDataSegmentLength, rejecting" 152 " TMR TASK_REASSIGN.\n"); 153 return ISCSI_TMF_RSP_REJECTED; 154 } 155 156 ref_lun = scsilun_to_int(&hdr->lun); 157 if (ref_lun != ref_cmd->se_cmd.orig_fe_lun) { 158 pr_err("Unable to perform connection recovery for" 159 " differing ref_lun: %llu ref_cmd orig_fe_lun: %llu\n", 160 ref_lun, ref_cmd->se_cmd.orig_fe_lun); 161 return ISCSI_TMF_RSP_REJECTED; 162 } 163 164 se_tmr->ref_task_tag = (__force u32)hdr->rtt; 165 tmr_req->ref_cmd = ref_cmd; 166 tmr_req->exp_data_sn = be32_to_cpu(hdr->exp_datasn); 167 tmr_req->conn_recovery = cr; 168 tmr_req->task_reassign = 1; 169 /* 170 * Command can now be reassigned to a new connection. 171 * The task management response must be sent before the 172 * reassignment actually happens. See iscsi_tmr_post_handler(). 173 */ 174 return ISCSI_TMF_RSP_COMPLETE; 175 } 176 177 static void iscsit_task_reassign_remove_cmd( 178 struct iscsit_cmd *cmd, 179 struct iscsi_conn_recovery *cr, 180 struct iscsit_session *sess) 181 { 182 int ret; 183 184 spin_lock(&cr->conn_recovery_cmd_lock); 185 ret = iscsit_remove_cmd_from_connection_recovery(cmd, sess); 186 spin_unlock(&cr->conn_recovery_cmd_lock); 187 if (!ret) { 188 pr_debug("iSCSI connection recovery successful for CID:" 189 " %hu on SID: %u\n", cr->cid, sess->sid); 190 iscsit_remove_active_connection_recovery_entry(cr, sess); 191 } 192 } 193 194 static int iscsit_task_reassign_complete_nop_out( 195 struct iscsi_tmr_req *tmr_req, 196 struct iscsit_conn *conn) 197 { 198 struct iscsit_cmd *cmd = tmr_req->ref_cmd; 199 struct iscsi_conn_recovery *cr; 200 201 if (!cmd->cr) { 202 pr_err("struct iscsi_conn_recovery pointer for ITT: 0x%08x" 203 " is NULL!\n", cmd->init_task_tag); 204 return -1; 205 } 206 cr = cmd->cr; 207 208 /* 209 * Reset the StatSN so a new one for this commands new connection 210 * will be assigned. 211 * Reset the ExpStatSN as well so we may receive Status SNACKs. 212 */ 213 cmd->stat_sn = cmd->exp_stat_sn = 0; 214 215 iscsit_task_reassign_remove_cmd(cmd, cr, conn->sess); 216 217 spin_lock_bh(&conn->cmd_lock); 218 list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list); 219 spin_unlock_bh(&conn->cmd_lock); 220 221 cmd->i_state = ISTATE_SEND_NOPIN; 222 iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state); 223 return 0; 224 } 225 226 static int iscsit_task_reassign_complete_write( 227 struct iscsit_cmd *cmd, 228 struct iscsi_tmr_req *tmr_req) 229 { 230 int no_build_r2ts = 0; 231 u32 length = 0, offset = 0; 232 struct iscsit_conn *conn = cmd->conn; 233 struct se_cmd *se_cmd = &cmd->se_cmd; 234 /* 235 * The Initiator must not send a R2T SNACK with a Begrun less than 236 * the TMR TASK_REASSIGN's ExpDataSN. 237 */ 238 if (!tmr_req->exp_data_sn) { 239 cmd->cmd_flags &= ~ICF_GOT_DATACK_SNACK; 240 cmd->acked_data_sn = 0; 241 } else { 242 cmd->cmd_flags |= ICF_GOT_DATACK_SNACK; 243 cmd->acked_data_sn = (tmr_req->exp_data_sn - 1); 244 } 245 246 /* 247 * The TMR TASK_REASSIGN's ExpDataSN contains the next R2TSN the 248 * Initiator is expecting. The Target controls all WRITE operations 249 * so if we have received all DataOUT we can safety ignore Initiator. 250 */ 251 if (cmd->cmd_flags & ICF_GOT_LAST_DATAOUT) { 252 if (!(cmd->se_cmd.transport_state & CMD_T_SENT)) { 253 pr_debug("WRITE ITT: 0x%08x: t_state: %d" 254 " never sent to transport\n", 255 cmd->init_task_tag, cmd->se_cmd.t_state); 256 target_execute_cmd(se_cmd); 257 return 0; 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->se_cmd.data_length) { 276 no_build_r2ts = 1; 277 length = (cmd->se_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 conn->conn_transport->iscsit_get_dataout(conn, cmd, true); 296 } 297 298 static int iscsit_task_reassign_complete_read( 299 struct iscsit_cmd *cmd, 300 struct iscsi_tmr_req *tmr_req) 301 { 302 struct iscsit_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 target_submit(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 } 350 351 static int iscsit_task_reassign_complete_none( 352 struct iscsit_cmd *cmd, 353 struct iscsi_tmr_req *tmr_req) 354 { 355 struct iscsit_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 } 361 362 static int iscsit_task_reassign_complete_scsi_cmnd( 363 struct iscsi_tmr_req *tmr_req, 364 struct iscsit_conn *conn) 365 { 366 struct iscsit_cmd *cmd = tmr_req->ref_cmd; 367 struct iscsi_conn_recovery *cr; 368 369 if (!cmd->cr) { 370 pr_err("struct iscsi_conn_recovery pointer for ITT: 0x%08x" 371 " is NULL!\n", cmd->init_task_tag); 372 return -1; 373 } 374 cr = cmd->cr; 375 376 /* 377 * Reset the StatSN so a new one for this commands new connection 378 * will be assigned. 379 * Reset the ExpStatSN as well so we may receive Status SNACKs. 380 */ 381 cmd->stat_sn = cmd->exp_stat_sn = 0; 382 383 iscsit_task_reassign_remove_cmd(cmd, cr, conn->sess); 384 385 spin_lock_bh(&conn->cmd_lock); 386 list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list); 387 spin_unlock_bh(&conn->cmd_lock); 388 389 if (cmd->se_cmd.se_cmd_flags & SCF_SENT_CHECK_CONDITION) { 390 cmd->i_state = ISTATE_SEND_STATUS; 391 iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state); 392 return 0; 393 } 394 395 switch (cmd->data_direction) { 396 case DMA_TO_DEVICE: 397 return iscsit_task_reassign_complete_write(cmd, tmr_req); 398 case DMA_FROM_DEVICE: 399 return iscsit_task_reassign_complete_read(cmd, tmr_req); 400 case DMA_NONE: 401 return iscsit_task_reassign_complete_none(cmd, tmr_req); 402 default: 403 pr_err("Unknown cmd->data_direction: 0x%02x\n", 404 cmd->data_direction); 405 return -1; 406 } 407 408 return 0; 409 } 410 411 static int iscsit_task_reassign_complete( 412 struct iscsi_tmr_req *tmr_req, 413 struct iscsit_conn *conn) 414 { 415 struct iscsit_cmd *cmd; 416 int ret = 0; 417 418 if (!tmr_req->ref_cmd) { 419 pr_err("TMR Request is missing a RefCmd struct iscsit_cmd.\n"); 420 return -1; 421 } 422 cmd = tmr_req->ref_cmd; 423 424 cmd->conn = conn; 425 426 switch (cmd->iscsi_opcode) { 427 case ISCSI_OP_NOOP_OUT: 428 ret = iscsit_task_reassign_complete_nop_out(tmr_req, conn); 429 break; 430 case ISCSI_OP_SCSI_CMD: 431 ret = iscsit_task_reassign_complete_scsi_cmnd(tmr_req, conn); 432 break; 433 default: 434 pr_err("Illegal iSCSI Opcode 0x%02x during" 435 " command reallegiance\n", cmd->iscsi_opcode); 436 return -1; 437 } 438 439 if (ret != 0) 440 return ret; 441 442 pr_debug("Completed connection reallegiance for Opcode: 0x%02x," 443 " ITT: 0x%08x to CID: %hu.\n", cmd->iscsi_opcode, 444 cmd->init_task_tag, conn->cid); 445 446 return 0; 447 } 448 449 /* 450 * Handles special after-the-fact actions related to TMRs. 451 * Right now the only one that its really needed for is 452 * connection recovery releated TASK_REASSIGN. 453 */ 454 int iscsit_tmr_post_handler(struct iscsit_cmd *cmd, struct iscsit_conn *conn) 455 { 456 struct iscsi_tmr_req *tmr_req = cmd->tmr_req; 457 struct se_tmr_req *se_tmr = cmd->se_cmd.se_tmr_req; 458 459 if (tmr_req->task_reassign && 460 (se_tmr->response == ISCSI_TMF_RSP_COMPLETE)) 461 return iscsit_task_reassign_complete(tmr_req, conn); 462 463 return 0; 464 } 465 EXPORT_SYMBOL(iscsit_tmr_post_handler); 466 467 /* 468 * Nothing to do here, but leave it for good measure. :-) 469 */ 470 static int iscsit_task_reassign_prepare_read( 471 struct iscsi_tmr_req *tmr_req, 472 struct iscsit_conn *conn) 473 { 474 return 0; 475 } 476 477 static void iscsit_task_reassign_prepare_unsolicited_dataout( 478 struct iscsit_cmd *cmd, 479 struct iscsit_conn *conn) 480 { 481 int i, j; 482 struct iscsi_pdu *pdu = NULL; 483 struct iscsi_seq *seq = NULL; 484 485 if (conn->sess->sess_ops->DataSequenceInOrder) { 486 cmd->data_sn = 0; 487 488 if (cmd->immediate_data) 489 cmd->r2t_offset += (cmd->first_burst_len - 490 cmd->seq_start_offset); 491 492 if (conn->sess->sess_ops->DataPDUInOrder) { 493 cmd->write_data_done -= (cmd->immediate_data) ? 494 (cmd->first_burst_len - 495 cmd->seq_start_offset) : 496 cmd->first_burst_len; 497 cmd->first_burst_len = 0; 498 return; 499 } 500 501 for (i = 0; i < cmd->pdu_count; i++) { 502 pdu = &cmd->pdu_list[i]; 503 504 if (pdu->status != ISCSI_PDU_RECEIVED_OK) 505 continue; 506 507 if ((pdu->offset >= cmd->seq_start_offset) && 508 ((pdu->offset + pdu->length) <= 509 cmd->seq_end_offset)) { 510 cmd->first_burst_len -= pdu->length; 511 cmd->write_data_done -= pdu->length; 512 pdu->status = ISCSI_PDU_NOT_RECEIVED; 513 } 514 } 515 } else { 516 for (i = 0; i < cmd->seq_count; i++) { 517 seq = &cmd->seq_list[i]; 518 519 if (seq->type != SEQTYPE_UNSOLICITED) 520 continue; 521 522 cmd->write_data_done -= 523 (seq->offset - seq->orig_offset); 524 cmd->first_burst_len = 0; 525 seq->data_sn = 0; 526 seq->offset = seq->orig_offset; 527 seq->next_burst_len = 0; 528 seq->status = DATAOUT_SEQUENCE_WITHIN_COMMAND_RECOVERY; 529 530 if (conn->sess->sess_ops->DataPDUInOrder) 531 continue; 532 533 for (j = 0; j < seq->pdu_count; j++) { 534 pdu = &cmd->pdu_list[j+seq->pdu_start]; 535 536 if (pdu->status != ISCSI_PDU_RECEIVED_OK) 537 continue; 538 539 pdu->status = ISCSI_PDU_NOT_RECEIVED; 540 } 541 } 542 } 543 } 544 545 static int iscsit_task_reassign_prepare_write( 546 struct iscsi_tmr_req *tmr_req, 547 struct iscsit_conn *conn) 548 { 549 struct iscsit_cmd *cmd = tmr_req->ref_cmd; 550 struct iscsi_pdu *pdu = NULL; 551 struct iscsi_r2t *r2t = NULL, *r2t_tmp; 552 int first_incomplete_r2t = 1, i = 0; 553 554 /* 555 * The command was in the process of receiving Unsolicited DataOUT when 556 * the connection failed. 557 */ 558 if (cmd->unsolicited_data) 559 iscsit_task_reassign_prepare_unsolicited_dataout(cmd, conn); 560 561 /* 562 * The Initiator is requesting R2Ts starting from zero, skip 563 * checking acknowledged R2Ts and start checking struct iscsi_r2ts 564 * greater than zero. 565 */ 566 if (!tmr_req->exp_data_sn) 567 goto drop_unacknowledged_r2ts; 568 569 /* 570 * We now check that the PDUs in DataOUT sequences below 571 * the TMR TASK_REASSIGN ExpDataSN (R2TSN the Initiator is 572 * expecting next) have all the DataOUT they require to complete 573 * the DataOUT sequence. First scan from R2TSN 0 to TMR 574 * TASK_REASSIGN ExpDataSN-1. 575 * 576 * If we have not received all DataOUT in question, we must 577 * make sure to make the appropriate changes to values in 578 * struct iscsit_cmd (and elsewhere depending on session parameters) 579 * so iscsit_build_r2ts_for_cmd() in iscsit_task_reassign_complete_write() 580 * will resend a new R2T for the DataOUT sequences in question. 581 */ 582 spin_lock_bh(&cmd->r2t_lock); 583 if (list_empty(&cmd->cmd_r2t_list)) { 584 spin_unlock_bh(&cmd->r2t_lock); 585 return -1; 586 } 587 588 list_for_each_entry(r2t, &cmd->cmd_r2t_list, r2t_list) { 589 590 if (r2t->r2t_sn >= tmr_req->exp_data_sn) 591 continue; 592 /* 593 * Safely ignore Recovery R2Ts and R2Ts that have completed 594 * DataOUT sequences. 595 */ 596 if (r2t->seq_complete) 597 continue; 598 599 if (r2t->recovery_r2t) 600 continue; 601 602 /* 603 * DataSequenceInOrder=Yes: 604 * 605 * Taking into account the iSCSI implementation requirement of 606 * MaxOutstandingR2T=1 while ErrorRecoveryLevel>0 and 607 * DataSequenceInOrder=Yes, we must take into consideration 608 * the following: 609 * 610 * DataSequenceInOrder=No: 611 * 612 * Taking into account that the Initiator controls the (possibly 613 * random) PDU Order in (possibly random) Sequence Order of 614 * DataOUT the target requests with R2Ts, we must take into 615 * consideration the following: 616 * 617 * DataPDUInOrder=Yes for DataSequenceInOrder=[Yes,No]: 618 * 619 * While processing non-complete R2T DataOUT sequence requests 620 * the Target will re-request only the total sequence length 621 * minus current received offset. This is because we must 622 * assume the initiator will continue sending DataOUT from the 623 * last PDU before the connection failed. 624 * 625 * DataPDUInOrder=No for DataSequenceInOrder=[Yes,No]: 626 * 627 * While processing non-complete R2T DataOUT sequence requests 628 * the Target will re-request the entire DataOUT sequence if 629 * any single PDU is missing from the sequence. This is because 630 * we have no logical method to determine the next PDU offset, 631 * and we must assume the Initiator will be sending any random 632 * PDU offset in the current sequence after TASK_REASSIGN 633 * has completed. 634 */ 635 if (conn->sess->sess_ops->DataSequenceInOrder) { 636 if (!first_incomplete_r2t) { 637 cmd->r2t_offset -= r2t->xfer_len; 638 goto next; 639 } 640 641 if (conn->sess->sess_ops->DataPDUInOrder) { 642 cmd->data_sn = 0; 643 cmd->r2t_offset -= (r2t->xfer_len - 644 cmd->next_burst_len); 645 first_incomplete_r2t = 0; 646 goto next; 647 } 648 649 cmd->data_sn = 0; 650 cmd->r2t_offset -= r2t->xfer_len; 651 652 for (i = 0; i < cmd->pdu_count; i++) { 653 pdu = &cmd->pdu_list[i]; 654 655 if (pdu->status != ISCSI_PDU_RECEIVED_OK) 656 continue; 657 658 if ((pdu->offset >= r2t->offset) && 659 (pdu->offset < (r2t->offset + 660 r2t->xfer_len))) { 661 cmd->next_burst_len -= pdu->length; 662 cmd->write_data_done -= pdu->length; 663 pdu->status = ISCSI_PDU_NOT_RECEIVED; 664 } 665 } 666 667 first_incomplete_r2t = 0; 668 } else { 669 struct iscsi_seq *seq; 670 671 seq = iscsit_get_seq_holder(cmd, r2t->offset, 672 r2t->xfer_len); 673 if (!seq) { 674 spin_unlock_bh(&cmd->r2t_lock); 675 return -1; 676 } 677 678 cmd->write_data_done -= 679 (seq->offset - seq->orig_offset); 680 seq->data_sn = 0; 681 seq->offset = seq->orig_offset; 682 seq->next_burst_len = 0; 683 seq->status = DATAOUT_SEQUENCE_WITHIN_COMMAND_RECOVERY; 684 685 cmd->seq_send_order--; 686 687 if (conn->sess->sess_ops->DataPDUInOrder) 688 goto next; 689 690 for (i = 0; i < seq->pdu_count; i++) { 691 pdu = &cmd->pdu_list[i+seq->pdu_start]; 692 693 if (pdu->status != ISCSI_PDU_RECEIVED_OK) 694 continue; 695 696 pdu->status = ISCSI_PDU_NOT_RECEIVED; 697 } 698 } 699 700 next: 701 cmd->outstanding_r2ts--; 702 } 703 spin_unlock_bh(&cmd->r2t_lock); 704 705 /* 706 * We now drop all unacknowledged R2Ts, ie: ExpDataSN from TMR 707 * TASK_REASSIGN to the last R2T in the list.. We are also careful 708 * to check that the Initiator is not requesting R2Ts for DataOUT 709 * sequences it has already completed. 710 * 711 * Free each R2T in question and adjust values in struct iscsit_cmd 712 * accordingly so iscsit_build_r2ts_for_cmd() do the rest of 713 * the work after the TMR TASK_REASSIGN Response is sent. 714 */ 715 drop_unacknowledged_r2ts: 716 717 cmd->cmd_flags &= ~ICF_SENT_LAST_R2T; 718 cmd->r2t_sn = tmr_req->exp_data_sn; 719 720 spin_lock_bh(&cmd->r2t_lock); 721 list_for_each_entry_safe(r2t, r2t_tmp, &cmd->cmd_r2t_list, r2t_list) { 722 /* 723 * Skip up to the R2T Sequence number provided by the 724 * iSCSI TASK_REASSIGN TMR 725 */ 726 if (r2t->r2t_sn < tmr_req->exp_data_sn) 727 continue; 728 729 if (r2t->seq_complete) { 730 pr_err("Initiator is requesting R2Ts from" 731 " R2TSN: 0x%08x, but R2TSN: 0x%08x, Offset: %u," 732 " Length: %u is already complete." 733 " BAD INITIATOR ERL=2 IMPLEMENTATION!\n", 734 tmr_req->exp_data_sn, r2t->r2t_sn, 735 r2t->offset, r2t->xfer_len); 736 spin_unlock_bh(&cmd->r2t_lock); 737 return -1; 738 } 739 740 if (r2t->recovery_r2t) { 741 iscsit_free_r2t(r2t, cmd); 742 continue; 743 } 744 745 /* DataSequenceInOrder=Yes: 746 * 747 * Taking into account the iSCSI implementation requirement of 748 * MaxOutstandingR2T=1 while ErrorRecoveryLevel>0 and 749 * DataSequenceInOrder=Yes, it's safe to subtract the R2Ts 750 * entire transfer length from the commands R2T offset marker. 751 * 752 * DataSequenceInOrder=No: 753 * 754 * We subtract the difference from struct iscsi_seq between the 755 * current offset and original offset from cmd->write_data_done 756 * for account for DataOUT PDUs already received. Then reset 757 * the current offset to the original and zero out the current 758 * burst length, to make sure we re-request the entire DataOUT 759 * sequence. 760 */ 761 if (conn->sess->sess_ops->DataSequenceInOrder) 762 cmd->r2t_offset -= r2t->xfer_len; 763 else 764 cmd->seq_send_order--; 765 766 cmd->outstanding_r2ts--; 767 iscsit_free_r2t(r2t, cmd); 768 } 769 spin_unlock_bh(&cmd->r2t_lock); 770 771 return 0; 772 } 773 774 /* 775 * Performs sanity checks TMR TASK_REASSIGN's ExpDataSN for 776 * a given struct iscsit_cmd. 777 */ 778 int iscsit_check_task_reassign_expdatasn( 779 struct iscsi_tmr_req *tmr_req, 780 struct iscsit_conn *conn) 781 { 782 struct iscsit_cmd *ref_cmd = tmr_req->ref_cmd; 783 784 if (ref_cmd->iscsi_opcode != ISCSI_OP_SCSI_CMD) 785 return 0; 786 787 if (ref_cmd->se_cmd.se_cmd_flags & SCF_SENT_CHECK_CONDITION) 788 return 0; 789 790 if (ref_cmd->data_direction == DMA_NONE) 791 return 0; 792 793 /* 794 * For READs the TMR TASK_REASSIGNs ExpDataSN contains the next DataSN 795 * of DataIN the Initiator is expecting. 796 * 797 * Also check that the Initiator is not re-requesting DataIN that has 798 * already been acknowledged with a DataAck SNACK. 799 */ 800 if (ref_cmd->data_direction == DMA_FROM_DEVICE) { 801 if (tmr_req->exp_data_sn > ref_cmd->data_sn) { 802 pr_err("Received ExpDataSN: 0x%08x for READ" 803 " in TMR TASK_REASSIGN greater than command's" 804 " DataSN: 0x%08x.\n", tmr_req->exp_data_sn, 805 ref_cmd->data_sn); 806 return -1; 807 } 808 if ((ref_cmd->cmd_flags & ICF_GOT_DATACK_SNACK) && 809 (tmr_req->exp_data_sn <= ref_cmd->acked_data_sn)) { 810 pr_err("Received ExpDataSN: 0x%08x for READ" 811 " in TMR TASK_REASSIGN for previously" 812 " acknowledged DataIN: 0x%08x," 813 " protocol error\n", tmr_req->exp_data_sn, 814 ref_cmd->acked_data_sn); 815 return -1; 816 } 817 return iscsit_task_reassign_prepare_read(tmr_req, conn); 818 } 819 820 /* 821 * For WRITEs the TMR TASK_REASSIGNs ExpDataSN contains the next R2TSN 822 * for R2Ts the Initiator is expecting. 823 * 824 * Do the magic in iscsit_task_reassign_prepare_write(). 825 */ 826 if (ref_cmd->data_direction == DMA_TO_DEVICE) { 827 if (tmr_req->exp_data_sn > ref_cmd->r2t_sn) { 828 pr_err("Received ExpDataSN: 0x%08x for WRITE" 829 " in TMR TASK_REASSIGN greater than command's" 830 " R2TSN: 0x%08x.\n", tmr_req->exp_data_sn, 831 ref_cmd->r2t_sn); 832 return -1; 833 } 834 return iscsit_task_reassign_prepare_write(tmr_req, conn); 835 } 836 837 pr_err("Unknown iSCSI data_direction: 0x%02x\n", 838 ref_cmd->data_direction); 839 840 return -1; 841 } 842