1/******************************************************************************* 2 * This file contains the iSCSI Target specific Task Management functions. 3 * 4 * (c) Copyright 2007-2013 Datera, Inc. 5 * 6 * Author: Nicholas A. Bellinger <nab@linux-iscsi.org> 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License as published by 10 * the Free Software Foundation; either version 2 of the License, or 11 * (at your option) any later version. 12 * 13 * This program is distributed in the hope that it will be useful, 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 * GNU General Public License for more details. 17 ******************************************************************************/ 18 19#include <asm/unaligned.h> 20#include <scsi/scsi_device.h> 21#include <scsi/iscsi_proto.h> 22#include <target/target_core_base.h> 23#include <target/target_core_fabric.h> 24#include <target/iscsi/iscsi_transport.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 (iscsi_sna_gte(be32_to_cpu(hdr->refcmdsn), conn->sess->exp_cmd_sn) && 53 iscsi_sna_lte(be32_to_cpu(hdr->refcmdsn), conn->sess->max_cmd_sn)) ? 54 ISCSI_TMF_RSP_COMPLETE : ISCSI_TMF_RSP_NO_TASK; 55 } 56 if (ref_cmd->cmd_sn != be32_to_cpu(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 = (__force u32)hdr->rtt; 64 tmr_req->ref_cmd = ref_cmd; 65 tmr_req->exp_data_sn = be32_to_cpu(hdr->exp_datasn); 66 67 return ISCSI_TMF_RSP_COMPLETE; 68} 69 70/* 71 * Called from iscsit_handle_task_mgt_cmd(). 72 */ 73int iscsit_tmr_task_warm_reset( 74 struct iscsi_conn *conn, 75 struct iscsi_tmr_req *tmr_req, 76 unsigned char *buf) 77{ 78 struct iscsi_session *sess = conn->sess; 79 struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess); 80 81 if (!na->tmr_warm_reset) { 82 pr_err("TMR Opcode TARGET_WARM_RESET authorization" 83 " failed for Initiator Node: %s\n", 84 sess->se_sess->se_node_acl->initiatorname); 85 return -1; 86 } 87 /* 88 * Do the real work in transport_generic_do_tmr(). 89 */ 90 return 0; 91} 92 93int iscsit_tmr_task_cold_reset( 94 struct iscsi_conn *conn, 95 struct iscsi_tmr_req *tmr_req, 96 unsigned char *buf) 97{ 98 struct iscsi_session *sess = conn->sess; 99 struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess); 100 101 if (!na->tmr_cold_reset) { 102 pr_err("TMR Opcode TARGET_COLD_RESET authorization" 103 " failed for Initiator Node: %s\n", 104 sess->se_sess->se_node_acl->initiatorname); 105 return -1; 106 } 107 /* 108 * Do the real work in transport_generic_do_tmr(). 109 */ 110 return 0; 111} 112 113u8 iscsit_tmr_task_reassign( 114 struct iscsi_cmd *cmd, 115 unsigned char *buf) 116{ 117 struct iscsi_cmd *ref_cmd = NULL; 118 struct iscsi_conn *conn = cmd->conn; 119 struct iscsi_conn_recovery *cr = NULL; 120 struct iscsi_tmr_req *tmr_req = cmd->tmr_req; 121 struct se_tmr_req *se_tmr = cmd->se_cmd.se_tmr_req; 122 struct iscsi_tm *hdr = (struct iscsi_tm *) buf; 123 int ret, ref_lun; 124 125 pr_debug("Got TASK_REASSIGN TMR ITT: 0x%08x," 126 " RefTaskTag: 0x%08x, ExpDataSN: 0x%08x, CID: %hu\n", 127 hdr->itt, hdr->rtt, hdr->exp_datasn, conn->cid); 128 129 if (conn->sess->sess_ops->ErrorRecoveryLevel != 2) { 130 pr_err("TMR TASK_REASSIGN not supported in ERL<2," 131 " ignoring request.\n"); 132 return ISCSI_TMF_RSP_NOT_SUPPORTED; 133 } 134 135 ret = iscsit_find_cmd_for_recovery(conn->sess, &ref_cmd, &cr, hdr->rtt); 136 if (ret == -2) { 137 pr_err("Command ITT: 0x%08x is still alligent to CID:" 138 " %hu\n", ref_cmd->init_task_tag, cr->cid); 139 return ISCSI_TMF_RSP_TASK_ALLEGIANT; 140 } else if (ret == -1) { 141 pr_err("Unable to locate RefTaskTag: 0x%08x in" 142 " connection recovery command list.\n", hdr->rtt); 143 return ISCSI_TMF_RSP_NO_TASK; 144 } 145 /* 146 * Temporary check to prevent connection recovery for 147 * connections with a differing Max*DataSegmentLength. 148 */ 149 if (cr->maxrecvdatasegmentlength != 150 conn->conn_ops->MaxRecvDataSegmentLength) { 151 pr_err("Unable to perform connection recovery for" 152 " differing MaxRecvDataSegmentLength, rejecting" 153 " TMR TASK_REASSIGN.\n"); 154 return ISCSI_TMF_RSP_REJECTED; 155 } 156 if (cr->maxxmitdatasegmentlength != 157 conn->conn_ops->MaxXmitDataSegmentLength) { 158 pr_err("Unable to perform connection recovery for" 159 " differing MaxXmitDataSegmentLength, rejecting" 160 " TMR TASK_REASSIGN.\n"); 161 return ISCSI_TMF_RSP_REJECTED; 162 } 163 164 ref_lun = scsilun_to_int(&hdr->lun); 165 if (ref_lun != ref_cmd->se_cmd.orig_fe_lun) { 166 pr_err("Unable to perform connection recovery for" 167 " differing ref_lun: %d ref_cmd orig_fe_lun: %u\n", 168 ref_lun, ref_cmd->se_cmd.orig_fe_lun); 169 return ISCSI_TMF_RSP_REJECTED; 170 } 171 172 se_tmr->ref_task_tag = (__force u32)hdr->rtt; 173 tmr_req->ref_cmd = ref_cmd; 174 tmr_req->exp_data_sn = be32_to_cpu(hdr->exp_datasn); 175 tmr_req->conn_recovery = cr; 176 tmr_req->task_reassign = 1; 177 /* 178 * Command can now be reassigned to a new connection. 179 * The task management response must be sent before the 180 * reassignment actually happens. See iscsi_tmr_post_handler(). 181 */ 182 return ISCSI_TMF_RSP_COMPLETE; 183} 184 185static void iscsit_task_reassign_remove_cmd( 186 struct iscsi_cmd *cmd, 187 struct iscsi_conn_recovery *cr, 188 struct iscsi_session *sess) 189{ 190 int ret; 191 192 spin_lock(&cr->conn_recovery_cmd_lock); 193 ret = iscsit_remove_cmd_from_connection_recovery(cmd, sess); 194 spin_unlock(&cr->conn_recovery_cmd_lock); 195 if (!ret) { 196 pr_debug("iSCSI connection recovery successful for CID:" 197 " %hu on SID: %u\n", cr->cid, sess->sid); 198 iscsit_remove_active_connection_recovery_entry(cr, sess); 199 } 200} 201 202static int iscsit_task_reassign_complete_nop_out( 203 struct iscsi_tmr_req *tmr_req, 204 struct iscsi_conn *conn) 205{ 206 struct iscsi_cmd *cmd = tmr_req->ref_cmd; 207 struct iscsi_conn_recovery *cr; 208 209 if (!cmd->cr) { 210 pr_err("struct iscsi_conn_recovery pointer for ITT: 0x%08x" 211 " is NULL!\n", cmd->init_task_tag); 212 return -1; 213 } 214 cr = cmd->cr; 215 216 /* 217 * Reset the StatSN so a new one for this commands new connection 218 * will be assigned. 219 * Reset the ExpStatSN as well so we may receive Status SNACKs. 220 */ 221 cmd->stat_sn = cmd->exp_stat_sn = 0; 222 223 iscsit_task_reassign_remove_cmd(cmd, cr, conn->sess); 224 225 spin_lock_bh(&conn->cmd_lock); 226 list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list); 227 spin_unlock_bh(&conn->cmd_lock); 228 229 cmd->i_state = ISTATE_SEND_NOPIN; 230 iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state); 231 return 0; 232} 233 234static int iscsit_task_reassign_complete_write( 235 struct iscsi_cmd *cmd, 236 struct iscsi_tmr_req *tmr_req) 237{ 238 int no_build_r2ts = 0; 239 u32 length = 0, offset = 0; 240 struct iscsi_conn *conn = cmd->conn; 241 struct se_cmd *se_cmd = &cmd->se_cmd; 242 /* 243 * The Initiator must not send a R2T SNACK with a Begrun less than 244 * the TMR TASK_REASSIGN's ExpDataSN. 245 */ 246 if (!tmr_req->exp_data_sn) { 247 cmd->cmd_flags &= ~ICF_GOT_DATACK_SNACK; 248 cmd->acked_data_sn = 0; 249 } else { 250 cmd->cmd_flags |= ICF_GOT_DATACK_SNACK; 251 cmd->acked_data_sn = (tmr_req->exp_data_sn - 1); 252 } 253 254 /* 255 * The TMR TASK_REASSIGN's ExpDataSN contains the next R2TSN the 256 * Initiator is expecting. The Target controls all WRITE operations 257 * so if we have received all DataOUT we can safety ignore Initiator. 258 */ 259 if (cmd->cmd_flags & ICF_GOT_LAST_DATAOUT) { 260 if (!(cmd->se_cmd.transport_state & CMD_T_SENT)) { 261 pr_debug("WRITE ITT: 0x%08x: t_state: %d" 262 " never sent to transport\n", 263 cmd->init_task_tag, cmd->se_cmd.t_state); 264 target_execute_cmd(se_cmd); 265 return 0; 266 } 267 268 cmd->i_state = ISTATE_SEND_STATUS; 269 iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state); 270 return 0; 271 } 272 273 /* 274 * Special case to deal with DataSequenceInOrder=No and Non-Immeidate 275 * Unsolicited DataOut. 276 */ 277 if (cmd->unsolicited_data) { 278 cmd->unsolicited_data = 0; 279 280 offset = cmd->next_burst_len = cmd->write_data_done; 281 282 if ((conn->sess->sess_ops->FirstBurstLength - offset) >= 283 cmd->se_cmd.data_length) { 284 no_build_r2ts = 1; 285 length = (cmd->se_cmd.data_length - offset); 286 } else 287 length = (conn->sess->sess_ops->FirstBurstLength - offset); 288 289 spin_lock_bh(&cmd->r2t_lock); 290 if (iscsit_add_r2t_to_list(cmd, offset, length, 0, 0) < 0) { 291 spin_unlock_bh(&cmd->r2t_lock); 292 return -1; 293 } 294 cmd->outstanding_r2ts++; 295 spin_unlock_bh(&cmd->r2t_lock); 296 297 if (no_build_r2ts) 298 return 0; 299 } 300 /* 301 * iscsit_build_r2ts_for_cmd() can handle the rest from here. 302 */ 303 return conn->conn_transport->iscsit_get_dataout(conn, cmd, true); 304} 305 306static int iscsit_task_reassign_complete_read( 307 struct iscsi_cmd *cmd, 308 struct iscsi_tmr_req *tmr_req) 309{ 310 struct iscsi_conn *conn = cmd->conn; 311 struct iscsi_datain_req *dr; 312 struct se_cmd *se_cmd = &cmd->se_cmd; 313 /* 314 * The Initiator must not send a Data SNACK with a BegRun less than 315 * the TMR TASK_REASSIGN's ExpDataSN. 316 */ 317 if (!tmr_req->exp_data_sn) { 318 cmd->cmd_flags &= ~ICF_GOT_DATACK_SNACK; 319 cmd->acked_data_sn = 0; 320 } else { 321 cmd->cmd_flags |= ICF_GOT_DATACK_SNACK; 322 cmd->acked_data_sn = (tmr_req->exp_data_sn - 1); 323 } 324 325 if (!(cmd->se_cmd.transport_state & CMD_T_SENT)) { 326 pr_debug("READ ITT: 0x%08x: t_state: %d never sent to" 327 " transport\n", cmd->init_task_tag, 328 cmd->se_cmd.t_state); 329 transport_handle_cdb_direct(se_cmd); 330 return 0; 331 } 332 333 if (!(se_cmd->transport_state & CMD_T_COMPLETE)) { 334 pr_err("READ ITT: 0x%08x: t_state: %d, never returned" 335 " from transport\n", cmd->init_task_tag, 336 cmd->se_cmd.t_state); 337 return -1; 338 } 339 340 dr = iscsit_allocate_datain_req(); 341 if (!dr) 342 return -1; 343 /* 344 * The TMR TASK_REASSIGN's ExpDataSN contains the next DataSN the 345 * Initiator is expecting. 346 */ 347 dr->data_sn = dr->begrun = tmr_req->exp_data_sn; 348 dr->runlength = 0; 349 dr->generate_recovery_values = 1; 350 dr->recovery = DATAIN_CONNECTION_RECOVERY; 351 352 iscsit_attach_datain_req(cmd, dr); 353 354 cmd->i_state = ISTATE_SEND_DATAIN; 355 iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state); 356 return 0; 357} 358 359static int iscsit_task_reassign_complete_none( 360 struct iscsi_cmd *cmd, 361 struct iscsi_tmr_req *tmr_req) 362{ 363 struct iscsi_conn *conn = cmd->conn; 364 365 cmd->i_state = ISTATE_SEND_STATUS; 366 iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state); 367 return 0; 368} 369 370static int iscsit_task_reassign_complete_scsi_cmnd( 371 struct iscsi_tmr_req *tmr_req, 372 struct iscsi_conn *conn) 373{ 374 struct iscsi_cmd *cmd = tmr_req->ref_cmd; 375 struct iscsi_conn_recovery *cr; 376 377 if (!cmd->cr) { 378 pr_err("struct iscsi_conn_recovery pointer for ITT: 0x%08x" 379 " is NULL!\n", cmd->init_task_tag); 380 return -1; 381 } 382 cr = cmd->cr; 383 384 /* 385 * Reset the StatSN so a new one for this commands new connection 386 * will be assigned. 387 * Reset the ExpStatSN as well so we may receive Status SNACKs. 388 */ 389 cmd->stat_sn = cmd->exp_stat_sn = 0; 390 391 iscsit_task_reassign_remove_cmd(cmd, cr, conn->sess); 392 393 spin_lock_bh(&conn->cmd_lock); 394 list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list); 395 spin_unlock_bh(&conn->cmd_lock); 396 397 if (cmd->se_cmd.se_cmd_flags & SCF_SENT_CHECK_CONDITION) { 398 cmd->i_state = ISTATE_SEND_STATUS; 399 iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state); 400 return 0; 401 } 402 403 switch (cmd->data_direction) { 404 case DMA_TO_DEVICE: 405 return iscsit_task_reassign_complete_write(cmd, tmr_req); 406 case DMA_FROM_DEVICE: 407 return iscsit_task_reassign_complete_read(cmd, tmr_req); 408 case DMA_NONE: 409 return iscsit_task_reassign_complete_none(cmd, tmr_req); 410 default: 411 pr_err("Unknown cmd->data_direction: 0x%02x\n", 412 cmd->data_direction); 413 return -1; 414 } 415 416 return 0; 417} 418 419static int iscsit_task_reassign_complete( 420 struct iscsi_tmr_req *tmr_req, 421 struct iscsi_conn *conn) 422{ 423 struct iscsi_cmd *cmd; 424 int ret = 0; 425 426 if (!tmr_req->ref_cmd) { 427 pr_err("TMR Request is missing a RefCmd struct iscsi_cmd.\n"); 428 return -1; 429 } 430 cmd = tmr_req->ref_cmd; 431 432 cmd->conn = conn; 433 434 switch (cmd->iscsi_opcode) { 435 case ISCSI_OP_NOOP_OUT: 436 ret = iscsit_task_reassign_complete_nop_out(tmr_req, conn); 437 break; 438 case ISCSI_OP_SCSI_CMD: 439 ret = iscsit_task_reassign_complete_scsi_cmnd(tmr_req, conn); 440 break; 441 default: 442 pr_err("Illegal iSCSI Opcode 0x%02x during" 443 " command realligence\n", cmd->iscsi_opcode); 444 return -1; 445 } 446 447 if (ret != 0) 448 return ret; 449 450 pr_debug("Completed connection realligence for Opcode: 0x%02x," 451 " ITT: 0x%08x to CID: %hu.\n", cmd->iscsi_opcode, 452 cmd->init_task_tag, conn->cid); 453 454 return 0; 455} 456 457/* 458 * Handles special after-the-fact actions related to TMRs. 459 * Right now the only one that its really needed for is 460 * connection recovery releated TASK_REASSIGN. 461 */ 462int iscsit_tmr_post_handler(struct iscsi_cmd *cmd, struct iscsi_conn *conn) 463{ 464 struct iscsi_tmr_req *tmr_req = cmd->tmr_req; 465 struct se_tmr_req *se_tmr = cmd->se_cmd.se_tmr_req; 466 467 if (tmr_req->task_reassign && 468 (se_tmr->response == ISCSI_TMF_RSP_COMPLETE)) 469 return iscsit_task_reassign_complete(tmr_req, conn); 470 471 return 0; 472} 473EXPORT_SYMBOL(iscsit_tmr_post_handler); 474 475/* 476 * Nothing to do here, but leave it for good measure. :-) 477 */ 478static int iscsit_task_reassign_prepare_read( 479 struct iscsi_tmr_req *tmr_req, 480 struct iscsi_conn *conn) 481{ 482 return 0; 483} 484 485static void iscsit_task_reassign_prepare_unsolicited_dataout( 486 struct iscsi_cmd *cmd, 487 struct iscsi_conn *conn) 488{ 489 int i, j; 490 struct iscsi_pdu *pdu = NULL; 491 struct iscsi_seq *seq = NULL; 492 493 if (conn->sess->sess_ops->DataSequenceInOrder) { 494 cmd->data_sn = 0; 495 496 if (cmd->immediate_data) 497 cmd->r2t_offset += (cmd->first_burst_len - 498 cmd->seq_start_offset); 499 500 if (conn->sess->sess_ops->DataPDUInOrder) { 501 cmd->write_data_done -= (cmd->immediate_data) ? 502 (cmd->first_burst_len - 503 cmd->seq_start_offset) : 504 cmd->first_burst_len; 505 cmd->first_burst_len = 0; 506 return; 507 } 508 509 for (i = 0; i < cmd->pdu_count; i++) { 510 pdu = &cmd->pdu_list[i]; 511 512 if (pdu->status != ISCSI_PDU_RECEIVED_OK) 513 continue; 514 515 if ((pdu->offset >= cmd->seq_start_offset) && 516 ((pdu->offset + pdu->length) <= 517 cmd->seq_end_offset)) { 518 cmd->first_burst_len -= pdu->length; 519 cmd->write_data_done -= pdu->length; 520 pdu->status = ISCSI_PDU_NOT_RECEIVED; 521 } 522 } 523 } else { 524 for (i = 0; i < cmd->seq_count; i++) { 525 seq = &cmd->seq_list[i]; 526 527 if (seq->type != SEQTYPE_UNSOLICITED) 528 continue; 529 530 cmd->write_data_done -= 531 (seq->offset - seq->orig_offset); 532 cmd->first_burst_len = 0; 533 seq->data_sn = 0; 534 seq->offset = seq->orig_offset; 535 seq->next_burst_len = 0; 536 seq->status = DATAOUT_SEQUENCE_WITHIN_COMMAND_RECOVERY; 537 538 if (conn->sess->sess_ops->DataPDUInOrder) 539 continue; 540 541 for (j = 0; j < seq->pdu_count; j++) { 542 pdu = &cmd->pdu_list[j+seq->pdu_start]; 543 544 if (pdu->status != ISCSI_PDU_RECEIVED_OK) 545 continue; 546 547 pdu->status = ISCSI_PDU_NOT_RECEIVED; 548 } 549 } 550 } 551} 552 553static int iscsit_task_reassign_prepare_write( 554 struct iscsi_tmr_req *tmr_req, 555 struct iscsi_conn *conn) 556{ 557 struct iscsi_cmd *cmd = tmr_req->ref_cmd; 558 struct iscsi_pdu *pdu = NULL; 559 struct iscsi_r2t *r2t = NULL, *r2t_tmp; 560 int first_incomplete_r2t = 1, i = 0; 561 562 /* 563 * The command was in the process of receiving Unsolicited DataOUT when 564 * the connection failed. 565 */ 566 if (cmd->unsolicited_data) 567 iscsit_task_reassign_prepare_unsolicited_dataout(cmd, conn); 568 569 /* 570 * The Initiator is requesting R2Ts starting from zero, skip 571 * checking acknowledged R2Ts and start checking struct iscsi_r2ts 572 * greater than zero. 573 */ 574 if (!tmr_req->exp_data_sn) 575 goto drop_unacknowledged_r2ts; 576 577 /* 578 * We now check that the PDUs in DataOUT sequences below 579 * the TMR TASK_REASSIGN ExpDataSN (R2TSN the Initiator is 580 * expecting next) have all the DataOUT they require to complete 581 * the DataOUT sequence. First scan from R2TSN 0 to TMR 582 * TASK_REASSIGN ExpDataSN-1. 583 * 584 * If we have not received all DataOUT in question, we must 585 * make sure to make the appropriate changes to values in 586 * struct iscsi_cmd (and elsewhere depending on session parameters) 587 * so iscsit_build_r2ts_for_cmd() in iscsit_task_reassign_complete_write() 588 * will resend a new R2T for the DataOUT sequences in question. 589 */ 590 spin_lock_bh(&cmd->r2t_lock); 591 if (list_empty(&cmd->cmd_r2t_list)) { 592 spin_unlock_bh(&cmd->r2t_lock); 593 return -1; 594 } 595 596 list_for_each_entry(r2t, &cmd->cmd_r2t_list, r2t_list) { 597 598 if (r2t->r2t_sn >= tmr_req->exp_data_sn) 599 continue; 600 /* 601 * Safely ignore Recovery R2Ts and R2Ts that have completed 602 * DataOUT sequences. 603 */ 604 if (r2t->seq_complete) 605 continue; 606 607 if (r2t->recovery_r2t) 608 continue; 609 610 /* 611 * DataSequenceInOrder=Yes: 612 * 613 * Taking into account the iSCSI implementation requirement of 614 * MaxOutstandingR2T=1 while ErrorRecoveryLevel>0 and 615 * DataSequenceInOrder=Yes, we must take into consideration 616 * the following: 617 * 618 * DataSequenceInOrder=No: 619 * 620 * Taking into account that the Initiator controls the (possibly 621 * random) PDU Order in (possibly random) Sequence Order of 622 * DataOUT the target requests with R2Ts, we must take into 623 * consideration the following: 624 * 625 * DataPDUInOrder=Yes for DataSequenceInOrder=[Yes,No]: 626 * 627 * While processing non-complete R2T DataOUT sequence requests 628 * the Target will re-request only the total sequence length 629 * minus current received offset. This is because we must 630 * assume the initiator will continue sending DataOUT from the 631 * last PDU before the connection failed. 632 * 633 * DataPDUInOrder=No for DataSequenceInOrder=[Yes,No]: 634 * 635 * While processing non-complete R2T DataOUT sequence requests 636 * the Target will re-request the entire DataOUT sequence if 637 * any single PDU is missing from the sequence. This is because 638 * we have no logical method to determine the next PDU offset, 639 * and we must assume the Initiator will be sending any random 640 * PDU offset in the current sequence after TASK_REASSIGN 641 * has completed. 642 */ 643 if (conn->sess->sess_ops->DataSequenceInOrder) { 644 if (!first_incomplete_r2t) { 645 cmd->r2t_offset -= r2t->xfer_len; 646 goto next; 647 } 648 649 if (conn->sess->sess_ops->DataPDUInOrder) { 650 cmd->data_sn = 0; 651 cmd->r2t_offset -= (r2t->xfer_len - 652 cmd->next_burst_len); 653 first_incomplete_r2t = 0; 654 goto next; 655 } 656 657 cmd->data_sn = 0; 658 cmd->r2t_offset -= r2t->xfer_len; 659 660 for (i = 0; i < cmd->pdu_count; i++) { 661 pdu = &cmd->pdu_list[i]; 662 663 if (pdu->status != ISCSI_PDU_RECEIVED_OK) 664 continue; 665 666 if ((pdu->offset >= r2t->offset) && 667 (pdu->offset < (r2t->offset + 668 r2t->xfer_len))) { 669 cmd->next_burst_len -= pdu->length; 670 cmd->write_data_done -= pdu->length; 671 pdu->status = ISCSI_PDU_NOT_RECEIVED; 672 } 673 } 674 675 first_incomplete_r2t = 0; 676 } else { 677 struct iscsi_seq *seq; 678 679 seq = iscsit_get_seq_holder(cmd, r2t->offset, 680 r2t->xfer_len); 681 if (!seq) { 682 spin_unlock_bh(&cmd->r2t_lock); 683 return -1; 684 } 685 686 cmd->write_data_done -= 687 (seq->offset - seq->orig_offset); 688 seq->data_sn = 0; 689 seq->offset = seq->orig_offset; 690 seq->next_burst_len = 0; 691 seq->status = DATAOUT_SEQUENCE_WITHIN_COMMAND_RECOVERY; 692 693 cmd->seq_send_order--; 694 695 if (conn->sess->sess_ops->DataPDUInOrder) 696 goto next; 697 698 for (i = 0; i < seq->pdu_count; i++) { 699 pdu = &cmd->pdu_list[i+seq->pdu_start]; 700 701 if (pdu->status != ISCSI_PDU_RECEIVED_OK) 702 continue; 703 704 pdu->status = ISCSI_PDU_NOT_RECEIVED; 705 } 706 } 707 708next: 709 cmd->outstanding_r2ts--; 710 } 711 spin_unlock_bh(&cmd->r2t_lock); 712 713 /* 714 * We now drop all unacknowledged R2Ts, ie: ExpDataSN from TMR 715 * TASK_REASSIGN to the last R2T in the list.. We are also careful 716 * to check that the Initiator is not requesting R2Ts for DataOUT 717 * sequences it has already completed. 718 * 719 * Free each R2T in question and adjust values in struct iscsi_cmd 720 * accordingly so iscsit_build_r2ts_for_cmd() do the rest of 721 * the work after the TMR TASK_REASSIGN Response is sent. 722 */ 723drop_unacknowledged_r2ts: 724 725 cmd->cmd_flags &= ~ICF_SENT_LAST_R2T; 726 cmd->r2t_sn = tmr_req->exp_data_sn; 727 728 spin_lock_bh(&cmd->r2t_lock); 729 list_for_each_entry_safe(r2t, r2t_tmp, &cmd->cmd_r2t_list, r2t_list) { 730 /* 731 * Skip up to the R2T Sequence number provided by the 732 * iSCSI TASK_REASSIGN TMR 733 */ 734 if (r2t->r2t_sn < tmr_req->exp_data_sn) 735 continue; 736 737 if (r2t->seq_complete) { 738 pr_err("Initiator is requesting R2Ts from" 739 " R2TSN: 0x%08x, but R2TSN: 0x%08x, Offset: %u," 740 " Length: %u is already complete." 741 " BAD INITIATOR ERL=2 IMPLEMENTATION!\n", 742 tmr_req->exp_data_sn, r2t->r2t_sn, 743 r2t->offset, r2t->xfer_len); 744 spin_unlock_bh(&cmd->r2t_lock); 745 return -1; 746 } 747 748 if (r2t->recovery_r2t) { 749 iscsit_free_r2t(r2t, cmd); 750 continue; 751 } 752 753 /* DataSequenceInOrder=Yes: 754 * 755 * Taking into account the iSCSI implementation requirement of 756 * MaxOutstandingR2T=1 while ErrorRecoveryLevel>0 and 757 * DataSequenceInOrder=Yes, it's safe to subtract the R2Ts 758 * entire transfer length from the commands R2T offset marker. 759 * 760 * DataSequenceInOrder=No: 761 * 762 * We subtract the difference from struct iscsi_seq between the 763 * current offset and original offset from cmd->write_data_done 764 * for account for DataOUT PDUs already received. Then reset 765 * the current offset to the original and zero out the current 766 * burst length, to make sure we re-request the entire DataOUT 767 * sequence. 768 */ 769 if (conn->sess->sess_ops->DataSequenceInOrder) 770 cmd->r2t_offset -= r2t->xfer_len; 771 else 772 cmd->seq_send_order--; 773 774 cmd->outstanding_r2ts--; 775 iscsit_free_r2t(r2t, cmd); 776 } 777 spin_unlock_bh(&cmd->r2t_lock); 778 779 return 0; 780} 781 782/* 783 * Performs sanity checks TMR TASK_REASSIGN's ExpDataSN for 784 * a given struct iscsi_cmd. 785 */ 786int iscsit_check_task_reassign_expdatasn( 787 struct iscsi_tmr_req *tmr_req, 788 struct iscsi_conn *conn) 789{ 790 struct iscsi_cmd *ref_cmd = tmr_req->ref_cmd; 791 792 if (ref_cmd->iscsi_opcode != ISCSI_OP_SCSI_CMD) 793 return 0; 794 795 if (ref_cmd->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