1 /*******************************************************************************
2 * This file contains the iSCSI Target specific Task Management functions.
4 * \u00a9 Copyright 2007-2011 RisingTide Systems LLC.
6 * Licensed to the Linux Foundation under the General Public License (GPL) version 2.
8 * Author: Nicholas A. Bellinger <nab@linux-iscsi.org>
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.
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 ******************************************************************************/
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>
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"
39 u8 iscsit_tmr_abort_task(
40 struct iscsi_cmd *cmd,
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;
49 ref_cmd = iscsit_find_cmd_from_itt(conn, hdr->rtt);
51 pr_err("Unable to locate RefTaskTag: 0x%08x on CID:"
52 " %hu.\n", hdr->rtt, conn->cid);
53 return (iscsi_sna_gte(be32_to_cpu(hdr->refcmdsn), conn->sess->exp_cmd_sn) &&
54 iscsi_sna_lte(be32_to_cpu(hdr->refcmdsn), conn->sess->max_cmd_sn)) ?
55 ISCSI_TMF_RSP_COMPLETE : ISCSI_TMF_RSP_NO_TASK;
57 if (ref_cmd->cmd_sn != be32_to_cpu(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;
64 se_tmr->ref_task_tag = (__force u32)hdr->rtt;
65 tmr_req->ref_cmd = ref_cmd;
66 tmr_req->exp_data_sn = be32_to_cpu(hdr->exp_datasn);
68 return ISCSI_TMF_RSP_COMPLETE;
72 * Called from iscsit_handle_task_mgt_cmd().
74 int iscsit_tmr_task_warm_reset(
75 struct iscsi_conn *conn,
76 struct iscsi_tmr_req *tmr_req,
79 struct iscsi_session *sess = conn->sess;
80 struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
82 if (!na->tmr_warm_reset) {
83 pr_err("TMR Opcode TARGET_WARM_RESET authorization"
84 " failed for Initiator Node: %s\n",
85 sess->se_sess->se_node_acl->initiatorname);
89 * Do the real work in transport_generic_do_tmr().
94 int iscsit_tmr_task_cold_reset(
95 struct iscsi_conn *conn,
96 struct iscsi_tmr_req *tmr_req,
99 struct iscsi_session *sess = conn->sess;
100 struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
102 if (!na->tmr_cold_reset) {
103 pr_err("TMR Opcode TARGET_COLD_RESET authorization"
104 " failed for Initiator Node: %s\n",
105 sess->se_sess->se_node_acl->initiatorname);
109 * Do the real work in transport_generic_do_tmr().
114 u8 iscsit_tmr_task_reassign(
115 struct iscsi_cmd *cmd,
118 struct iscsi_cmd *ref_cmd = NULL;
119 struct iscsi_conn *conn = cmd->conn;
120 struct iscsi_conn_recovery *cr = NULL;
121 struct iscsi_tmr_req *tmr_req = cmd->tmr_req;
122 struct se_tmr_req *se_tmr = cmd->se_cmd.se_tmr_req;
123 struct iscsi_tm *hdr = (struct iscsi_tm *) buf;
126 pr_debug("Got TASK_REASSIGN TMR ITT: 0x%08x,"
127 " RefTaskTag: 0x%08x, ExpDataSN: 0x%08x, CID: %hu\n",
128 hdr->itt, hdr->rtt, hdr->exp_datasn, conn->cid);
130 if (conn->sess->sess_ops->ErrorRecoveryLevel != 2) {
131 pr_err("TMR TASK_REASSIGN not supported in ERL<2,"
132 " ignoring request.\n");
133 return ISCSI_TMF_RSP_NOT_SUPPORTED;
136 ret = iscsit_find_cmd_for_recovery(conn->sess, &ref_cmd, &cr, hdr->rtt);
138 pr_err("Command ITT: 0x%08x is still alligent to CID:"
139 " %hu\n", ref_cmd->init_task_tag, cr->cid);
140 return ISCSI_TMF_RSP_TASK_ALLEGIANT;
141 } else if (ret == -1) {
142 pr_err("Unable to locate RefTaskTag: 0x%08x in"
143 " connection recovery command list.\n", hdr->rtt);
144 return ISCSI_TMF_RSP_NO_TASK;
147 * Temporary check to prevent connection recovery for
148 * connections with a differing Max*DataSegmentLength.
150 if (cr->maxrecvdatasegmentlength !=
151 conn->conn_ops->MaxRecvDataSegmentLength) {
152 pr_err("Unable to perform connection recovery for"
153 " differing MaxRecvDataSegmentLength, rejecting"
154 " TMR TASK_REASSIGN.\n");
155 return ISCSI_TMF_RSP_REJECTED;
157 if (cr->maxxmitdatasegmentlength !=
158 conn->conn_ops->MaxXmitDataSegmentLength) {
159 pr_err("Unable to perform connection recovery for"
160 " differing MaxXmitDataSegmentLength, rejecting"
161 " TMR TASK_REASSIGN.\n");
162 return ISCSI_TMF_RSP_REJECTED;
165 ref_lun = scsilun_to_int(&hdr->lun);
166 if (ref_lun != ref_cmd->se_cmd.orig_fe_lun) {
167 pr_err("Unable to perform connection recovery for"
168 " differing ref_lun: %d ref_cmd orig_fe_lun: %u\n",
169 ref_lun, ref_cmd->se_cmd.orig_fe_lun);
170 return ISCSI_TMF_RSP_REJECTED;
173 se_tmr->ref_task_tag = (__force u32)hdr->rtt;
174 tmr_req->ref_cmd = ref_cmd;
175 tmr_req->exp_data_sn = be32_to_cpu(hdr->exp_datasn);
176 tmr_req->conn_recovery = cr;
177 tmr_req->task_reassign = 1;
179 * Command can now be reassigned to a new connection.
180 * The task management response must be sent before the
181 * reassignment actually happens. See iscsi_tmr_post_handler().
183 return ISCSI_TMF_RSP_COMPLETE;
186 static void iscsit_task_reassign_remove_cmd(
187 struct iscsi_cmd *cmd,
188 struct iscsi_conn_recovery *cr,
189 struct iscsi_session *sess)
193 spin_lock(&cr->conn_recovery_cmd_lock);
194 ret = iscsit_remove_cmd_from_connection_recovery(cmd, sess);
195 spin_unlock(&cr->conn_recovery_cmd_lock);
197 pr_debug("iSCSI connection recovery successful for CID:"
198 " %hu on SID: %u\n", cr->cid, sess->sid);
199 iscsit_remove_active_connection_recovery_entry(cr, sess);
203 static int iscsit_task_reassign_complete_nop_out(
204 struct iscsi_tmr_req *tmr_req,
205 struct iscsi_conn *conn)
207 struct iscsi_cmd *cmd = tmr_req->ref_cmd;
208 struct iscsi_conn_recovery *cr;
211 pr_err("struct iscsi_conn_recovery pointer for ITT: 0x%08x"
212 " is NULL!\n", cmd->init_task_tag);
218 * Reset the StatSN so a new one for this commands new connection
220 * Reset the ExpStatSN as well so we may receive Status SNACKs.
222 cmd->stat_sn = cmd->exp_stat_sn = 0;
224 iscsit_task_reassign_remove_cmd(cmd, cr, conn->sess);
226 spin_lock_bh(&conn->cmd_lock);
227 list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
228 spin_unlock_bh(&conn->cmd_lock);
230 cmd->i_state = ISTATE_SEND_NOPIN;
231 iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
235 static int iscsit_task_reassign_complete_write(
236 struct iscsi_cmd *cmd,
237 struct iscsi_tmr_req *tmr_req)
239 int no_build_r2ts = 0;
240 u32 length = 0, offset = 0;
241 struct iscsi_conn *conn = cmd->conn;
242 struct se_cmd *se_cmd = &cmd->se_cmd;
244 * The Initiator must not send a R2T SNACK with a Begrun less than
245 * the TMR TASK_REASSIGN's ExpDataSN.
247 if (!tmr_req->exp_data_sn) {
248 cmd->cmd_flags &= ~ICF_GOT_DATACK_SNACK;
249 cmd->acked_data_sn = 0;
251 cmd->cmd_flags |= ICF_GOT_DATACK_SNACK;
252 cmd->acked_data_sn = (tmr_req->exp_data_sn - 1);
256 * The TMR TASK_REASSIGN's ExpDataSN contains the next R2TSN the
257 * Initiator is expecting. The Target controls all WRITE operations
258 * so if we have received all DataOUT we can safety ignore Initiator.
260 if (cmd->cmd_flags & ICF_GOT_LAST_DATAOUT) {
261 if (!(cmd->se_cmd.transport_state & CMD_T_SENT)) {
262 pr_debug("WRITE ITT: 0x%08x: t_state: %d"
263 " never sent to transport\n",
264 cmd->init_task_tag, cmd->se_cmd.t_state);
265 target_execute_cmd(se_cmd);
269 cmd->i_state = ISTATE_SEND_STATUS;
270 iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
275 * Special case to deal with DataSequenceInOrder=No and Non-Immeidate
276 * Unsolicited DataOut.
278 if (cmd->unsolicited_data) {
279 cmd->unsolicited_data = 0;
281 offset = cmd->next_burst_len = cmd->write_data_done;
283 if ((conn->sess->sess_ops->FirstBurstLength - offset) >=
284 cmd->se_cmd.data_length) {
286 length = (cmd->se_cmd.data_length - offset);
288 length = (conn->sess->sess_ops->FirstBurstLength - offset);
290 spin_lock_bh(&cmd->r2t_lock);
291 if (iscsit_add_r2t_to_list(cmd, offset, length, 0, 0) < 0) {
292 spin_unlock_bh(&cmd->r2t_lock);
295 cmd->outstanding_r2ts++;
296 spin_unlock_bh(&cmd->r2t_lock);
302 * iscsit_build_r2ts_for_cmd() can handle the rest from here.
304 return iscsit_build_r2ts_for_cmd(cmd, conn, true);
307 static int iscsit_task_reassign_complete_read(
308 struct iscsi_cmd *cmd,
309 struct iscsi_tmr_req *tmr_req)
311 struct iscsi_conn *conn = cmd->conn;
312 struct iscsi_datain_req *dr;
313 struct se_cmd *se_cmd = &cmd->se_cmd;
315 * The Initiator must not send a Data SNACK with a BegRun less than
316 * the TMR TASK_REASSIGN's ExpDataSN.
318 if (!tmr_req->exp_data_sn) {
319 cmd->cmd_flags &= ~ICF_GOT_DATACK_SNACK;
320 cmd->acked_data_sn = 0;
322 cmd->cmd_flags |= ICF_GOT_DATACK_SNACK;
323 cmd->acked_data_sn = (tmr_req->exp_data_sn - 1);
326 if (!(cmd->se_cmd.transport_state & CMD_T_SENT)) {
327 pr_debug("READ ITT: 0x%08x: t_state: %d never sent to"
328 " transport\n", cmd->init_task_tag,
329 cmd->se_cmd.t_state);
330 transport_handle_cdb_direct(se_cmd);
334 if (!(se_cmd->transport_state & CMD_T_COMPLETE)) {
335 pr_err("READ ITT: 0x%08x: t_state: %d, never returned"
336 " from transport\n", cmd->init_task_tag,
337 cmd->se_cmd.t_state);
341 dr = iscsit_allocate_datain_req();
345 * The TMR TASK_REASSIGN's ExpDataSN contains the next DataSN the
346 * Initiator is expecting.
348 dr->data_sn = dr->begrun = tmr_req->exp_data_sn;
350 dr->generate_recovery_values = 1;
351 dr->recovery = DATAIN_CONNECTION_RECOVERY;
353 iscsit_attach_datain_req(cmd, dr);
355 cmd->i_state = ISTATE_SEND_DATAIN;
356 iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
360 static int iscsit_task_reassign_complete_none(
361 struct iscsi_cmd *cmd,
362 struct iscsi_tmr_req *tmr_req)
364 struct iscsi_conn *conn = cmd->conn;
366 cmd->i_state = ISTATE_SEND_STATUS;
367 iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
371 static int iscsit_task_reassign_complete_scsi_cmnd(
372 struct iscsi_tmr_req *tmr_req,
373 struct iscsi_conn *conn)
375 struct iscsi_cmd *cmd = tmr_req->ref_cmd;
376 struct iscsi_conn_recovery *cr;
379 pr_err("struct iscsi_conn_recovery pointer for ITT: 0x%08x"
380 " is NULL!\n", cmd->init_task_tag);
386 * Reset the StatSN so a new one for this commands new connection
388 * Reset the ExpStatSN as well so we may receive Status SNACKs.
390 cmd->stat_sn = cmd->exp_stat_sn = 0;
392 iscsit_task_reassign_remove_cmd(cmd, cr, conn->sess);
394 spin_lock_bh(&conn->cmd_lock);
395 list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
396 spin_unlock_bh(&conn->cmd_lock);
398 if (cmd->se_cmd.se_cmd_flags & SCF_SENT_CHECK_CONDITION) {
399 cmd->i_state = ISTATE_SEND_STATUS;
400 iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
404 switch (cmd->data_direction) {
406 return iscsit_task_reassign_complete_write(cmd, tmr_req);
407 case DMA_FROM_DEVICE:
408 return iscsit_task_reassign_complete_read(cmd, tmr_req);
410 return iscsit_task_reassign_complete_none(cmd, tmr_req);
412 pr_err("Unknown cmd->data_direction: 0x%02x\n",
413 cmd->data_direction);
420 static int iscsit_task_reassign_complete(
421 struct iscsi_tmr_req *tmr_req,
422 struct iscsi_conn *conn)
424 struct iscsi_cmd *cmd;
427 if (!tmr_req->ref_cmd) {
428 pr_err("TMR Request is missing a RefCmd struct iscsi_cmd.\n");
431 cmd = tmr_req->ref_cmd;
435 switch (cmd->iscsi_opcode) {
436 case ISCSI_OP_NOOP_OUT:
437 ret = iscsit_task_reassign_complete_nop_out(tmr_req, conn);
439 case ISCSI_OP_SCSI_CMD:
440 ret = iscsit_task_reassign_complete_scsi_cmnd(tmr_req, conn);
443 pr_err("Illegal iSCSI Opcode 0x%02x during"
444 " command realligence\n", cmd->iscsi_opcode);
451 pr_debug("Completed connection realligence for Opcode: 0x%02x,"
452 " ITT: 0x%08x to CID: %hu.\n", cmd->iscsi_opcode,
453 cmd->init_task_tag, conn->cid);
459 * Handles special after-the-fact actions related to TMRs.
460 * Right now the only one that its really needed for is
461 * connection recovery releated TASK_REASSIGN.
463 int iscsit_tmr_post_handler(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
465 struct iscsi_tmr_req *tmr_req = cmd->tmr_req;
466 struct se_tmr_req *se_tmr = cmd->se_cmd.se_tmr_req;
468 if (tmr_req->task_reassign &&
469 (se_tmr->response == ISCSI_TMF_RSP_COMPLETE))
470 return iscsit_task_reassign_complete(tmr_req, conn);
476 * Nothing to do here, but leave it for good measure. :-)
478 static int iscsit_task_reassign_prepare_read(
479 struct iscsi_tmr_req *tmr_req,
480 struct iscsi_conn *conn)
485 static void iscsit_task_reassign_prepare_unsolicited_dataout(
486 struct iscsi_cmd *cmd,
487 struct iscsi_conn *conn)
490 struct iscsi_pdu *pdu = NULL;
491 struct iscsi_seq *seq = NULL;
493 if (conn->sess->sess_ops->DataSequenceInOrder) {
496 if (cmd->immediate_data)
497 cmd->r2t_offset += (cmd->first_burst_len -
498 cmd->seq_start_offset);
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;
509 for (i = 0; i < cmd->pdu_count; i++) {
510 pdu = &cmd->pdu_list[i];
512 if (pdu->status != ISCSI_PDU_RECEIVED_OK)
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;
524 for (i = 0; i < cmd->seq_count; i++) {
525 seq = &cmd->seq_list[i];
527 if (seq->type != SEQTYPE_UNSOLICITED)
530 cmd->write_data_done -=
531 (seq->offset - seq->orig_offset);
532 cmd->first_burst_len = 0;
534 seq->offset = seq->orig_offset;
535 seq->next_burst_len = 0;
536 seq->status = DATAOUT_SEQUENCE_WITHIN_COMMAND_RECOVERY;
538 if (conn->sess->sess_ops->DataPDUInOrder)
541 for (j = 0; j < seq->pdu_count; j++) {
542 pdu = &cmd->pdu_list[j+seq->pdu_start];
544 if (pdu->status != ISCSI_PDU_RECEIVED_OK)
547 pdu->status = ISCSI_PDU_NOT_RECEIVED;
553 static int iscsit_task_reassign_prepare_write(
554 struct iscsi_tmr_req *tmr_req,
555 struct iscsi_conn *conn)
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;
563 * The command was in the process of receiving Unsolicited DataOUT when
564 * the connection failed.
566 if (cmd->unsolicited_data)
567 iscsit_task_reassign_prepare_unsolicited_dataout(cmd, conn);
570 * The Initiator is requesting R2Ts starting from zero, skip
571 * checking acknowledged R2Ts and start checking struct iscsi_r2ts
574 if (!tmr_req->exp_data_sn)
575 goto drop_unacknowledged_r2ts;
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.
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.
590 spin_lock_bh(&cmd->r2t_lock);
591 if (list_empty(&cmd->cmd_r2t_list)) {
592 spin_unlock_bh(&cmd->r2t_lock);
596 list_for_each_entry(r2t, &cmd->cmd_r2t_list, r2t_list) {
598 if (r2t->r2t_sn >= tmr_req->exp_data_sn)
601 * Safely ignore Recovery R2Ts and R2Ts that have completed
604 if (r2t->seq_complete)
607 if (r2t->recovery_r2t)
611 * DataSequenceInOrder=Yes:
613 * Taking into account the iSCSI implementation requirement of
614 * MaxOutstandingR2T=1 while ErrorRecoveryLevel>0 and
615 * DataSequenceInOrder=Yes, we must take into consideration
618 * DataSequenceInOrder=No:
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:
625 * DataPDUInOrder=Yes for DataSequenceInOrder=[Yes,No]:
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.
633 * DataPDUInOrder=No for DataSequenceInOrder=[Yes,No]:
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
643 if (conn->sess->sess_ops->DataSequenceInOrder) {
644 if (!first_incomplete_r2t) {
645 cmd->r2t_offset -= r2t->xfer_len;
649 if (conn->sess->sess_ops->DataPDUInOrder) {
651 cmd->r2t_offset -= (r2t->xfer_len -
652 cmd->next_burst_len);
653 first_incomplete_r2t = 0;
658 cmd->r2t_offset -= r2t->xfer_len;
660 for (i = 0; i < cmd->pdu_count; i++) {
661 pdu = &cmd->pdu_list[i];
663 if (pdu->status != ISCSI_PDU_RECEIVED_OK)
666 if ((pdu->offset >= r2t->offset) &&
667 (pdu->offset < (r2t->offset +
669 cmd->next_burst_len -= pdu->length;
670 cmd->write_data_done -= pdu->length;
671 pdu->status = ISCSI_PDU_NOT_RECEIVED;
675 first_incomplete_r2t = 0;
677 struct iscsi_seq *seq;
679 seq = iscsit_get_seq_holder(cmd, r2t->offset,
682 spin_unlock_bh(&cmd->r2t_lock);
686 cmd->write_data_done -=
687 (seq->offset - seq->orig_offset);
689 seq->offset = seq->orig_offset;
690 seq->next_burst_len = 0;
691 seq->status = DATAOUT_SEQUENCE_WITHIN_COMMAND_RECOVERY;
693 cmd->seq_send_order--;
695 if (conn->sess->sess_ops->DataPDUInOrder)
698 for (i = 0; i < seq->pdu_count; i++) {
699 pdu = &cmd->pdu_list[i+seq->pdu_start];
701 if (pdu->status != ISCSI_PDU_RECEIVED_OK)
704 pdu->status = ISCSI_PDU_NOT_RECEIVED;
709 cmd->outstanding_r2ts--;
711 spin_unlock_bh(&cmd->r2t_lock);
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.
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.
723 drop_unacknowledged_r2ts:
725 cmd->cmd_flags &= ~ICF_SENT_LAST_R2T;
726 cmd->r2t_sn = tmr_req->exp_data_sn;
728 spin_lock_bh(&cmd->r2t_lock);
729 list_for_each_entry_safe(r2t, r2t_tmp, &cmd->cmd_r2t_list, r2t_list) {
731 * Skip up to the R2T Sequence number provided by the
732 * iSCSI TASK_REASSIGN TMR
734 if (r2t->r2t_sn < tmr_req->exp_data_sn)
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);
748 if (r2t->recovery_r2t) {
749 iscsit_free_r2t(r2t, cmd);
753 /* DataSequenceInOrder=Yes:
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.
760 * DataSequenceInOrder=No:
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
769 if (conn->sess->sess_ops->DataSequenceInOrder)
770 cmd->r2t_offset -= r2t->xfer_len;
772 cmd->seq_send_order--;
774 cmd->outstanding_r2ts--;
775 iscsit_free_r2t(r2t, cmd);
777 spin_unlock_bh(&cmd->r2t_lock);
783 * Performs sanity checks TMR TASK_REASSIGN's ExpDataSN for
784 * a given struct iscsi_cmd.
786 int iscsit_check_task_reassign_expdatasn(
787 struct iscsi_tmr_req *tmr_req,
788 struct iscsi_conn *conn)
790 struct iscsi_cmd *ref_cmd = tmr_req->ref_cmd;
792 if (ref_cmd->iscsi_opcode != ISCSI_OP_SCSI_CMD)
795 if (ref_cmd->se_cmd.se_cmd_flags & SCF_SENT_CHECK_CONDITION)
798 if (ref_cmd->data_direction == DMA_NONE)
802 * For READs the TMR TASK_REASSIGNs ExpDataSN contains the next DataSN
803 * of DataIN the Initiator is expecting.
805 * Also check that the Initiator is not re-requesting DataIN that has
806 * already been acknowledged with a DataAck SNACK.
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,
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);
825 return iscsit_task_reassign_prepare_read(tmr_req, conn);
829 * For WRITEs the TMR TASK_REASSIGNs ExpDataSN contains the next R2TSN
830 * for R2Ts the Initiator is expecting.
832 * Do the magic in iscsit_task_reassign_prepare_write().
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,
842 return iscsit_task_reassign_prepare_write(tmr_req, conn);
845 pr_err("Unknown iSCSI data_direction: 0x%02x\n",
846 ref_cmd->data_direction);