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1// SPDX-License-Identifier: GPL-2.0-or-later2/*******************************************************************************3 * This file contains error recovery level one used by the iSCSI Target driver.4 *5 * (c) Copyright 2007-2013 Datera, Inc.6 *7 * Author: Nicholas A. Bellinger <nab@linux-iscsi.org>8 *9 ******************************************************************************/10 11#include <linux/list.h>12#include <linux/slab.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_tpg.h"23#include "iscsi_target_util.h"24#include "iscsi_target_erl0.h"25#include "iscsi_target_erl1.h"26#include "iscsi_target_erl2.h"27#include "iscsi_target.h"28 29#define OFFLOAD_BUF_SIZE	32768U30 31/*32 *	Used to dump excess datain payload for certain error recovery33 *	situations.  Receive in OFFLOAD_BUF_SIZE max of datain per rx_data().34 *35 *	dump_padding_digest denotes if padding and data digests need36 *	to be dumped.37 */38int iscsit_dump_data_payload(39	struct iscsit_conn *conn,40	u32 buf_len,41	int dump_padding_digest)42{43	char *buf;44	int ret = DATAOUT_WITHIN_COMMAND_RECOVERY, rx_got;45	u32 length, offset = 0, size;46	struct kvec iov;47 48	if (conn->sess->sess_ops->RDMAExtensions)49		return 0;50 51	if (dump_padding_digest) {52		buf_len = ALIGN(buf_len, 4);53		if (conn->conn_ops->DataDigest)54			buf_len += ISCSI_CRC_LEN;55	}56 57	length = min(buf_len, OFFLOAD_BUF_SIZE);58 59	buf = kzalloc(length, GFP_ATOMIC);60	if (!buf) {61		pr_err("Unable to allocate %u bytes for offload"62				" buffer.\n", length);63		return -1;64	}65	memset(&iov, 0, sizeof(struct kvec));66 67	while (offset < buf_len) {68		size = min(buf_len - offset, length);69 70		iov.iov_len = size;71		iov.iov_base = buf;72 73		rx_got = rx_data(conn, &iov, 1, size);74		if (rx_got != size) {75			ret = DATAOUT_CANNOT_RECOVER;76			break;77		}78 79		offset += size;80	}81 82	kfree(buf);83	return ret;84}85 86/*87 *	Used for retransmitting R2Ts from a R2T SNACK request.88 */89static int iscsit_send_recovery_r2t_for_snack(90	struct iscsit_cmd *cmd,91	struct iscsi_r2t *r2t)92{93	/*94	 * If the struct iscsi_r2t has not been sent yet, we can safely95	 * ignore retransmission96	 * of the R2TSN in question.97	 */98	spin_lock_bh(&cmd->r2t_lock);99	if (!r2t->sent_r2t) {100		spin_unlock_bh(&cmd->r2t_lock);101		return 0;102	}103	r2t->sent_r2t = 0;104	spin_unlock_bh(&cmd->r2t_lock);105 106	iscsit_add_cmd_to_immediate_queue(cmd, cmd->conn, ISTATE_SEND_R2T);107 108	return 0;109}110 111static int iscsit_handle_r2t_snack(112	struct iscsit_cmd *cmd,113	unsigned char *buf,114	u32 begrun,115	u32 runlength)116{117	u32 last_r2tsn;118	struct iscsi_r2t *r2t;119 120	/*121	 * Make sure the initiator is not requesting retransmission122	 * of R2TSNs already acknowledged by a TMR TASK_REASSIGN.123	 */124	if ((cmd->cmd_flags & ICF_GOT_DATACK_SNACK) &&125	    (begrun <= cmd->acked_data_sn)) {126		pr_err("ITT: 0x%08x, R2T SNACK requesting"127			" retransmission of R2TSN: 0x%08x to 0x%08x but already"128			" acked to  R2TSN: 0x%08x by TMR TASK_REASSIGN,"129			" protocol error.\n", cmd->init_task_tag, begrun,130			(begrun + runlength), cmd->acked_data_sn);131 132		return iscsit_reject_cmd(cmd, ISCSI_REASON_PROTOCOL_ERROR, buf);133	}134 135	if (runlength) {136		if ((begrun + runlength) > cmd->r2t_sn) {137			pr_err("Command ITT: 0x%08x received R2T SNACK"138			" with BegRun: 0x%08x, RunLength: 0x%08x, exceeds"139			" current R2TSN: 0x%08x, protocol error.\n",140			cmd->init_task_tag, begrun, runlength, cmd->r2t_sn);141			return iscsit_reject_cmd(cmd,142					ISCSI_REASON_BOOKMARK_INVALID, buf);143		}144		last_r2tsn = (begrun + runlength);145	} else146		last_r2tsn = cmd->r2t_sn;147 148	while (begrun < last_r2tsn) {149		r2t = iscsit_get_holder_for_r2tsn(cmd, begrun);150		if (!r2t)151			return -1;152		if (iscsit_send_recovery_r2t_for_snack(cmd, r2t) < 0)153			return -1;154 155		begrun++;156	}157 158	return 0;159}160 161/*162 *	Generates Offsets and NextBurstLength based on Begrun and Runlength163 *	carried in a Data SNACK or ExpDataSN in TMR TASK_REASSIGN.164 *165 *	For DataSequenceInOrder=Yes and DataPDUInOrder=[Yes,No] only.166 *167 *	FIXME: How is this handled for a RData SNACK?168 */169int iscsit_create_recovery_datain_values_datasequenceinorder_yes(170	struct iscsit_cmd *cmd,171	struct iscsi_datain_req *dr)172{173	u32 data_sn = 0, data_sn_count = 0;174	u32 pdu_start = 0, seq_no = 0;175	u32 begrun = dr->begrun;176	struct iscsit_conn *conn = cmd->conn;177 178	while (begrun > data_sn++) {179		data_sn_count++;180		if ((dr->next_burst_len +181		     conn->conn_ops->MaxRecvDataSegmentLength) <182		     conn->sess->sess_ops->MaxBurstLength) {183			dr->read_data_done +=184				conn->conn_ops->MaxRecvDataSegmentLength;185			dr->next_burst_len +=186				conn->conn_ops->MaxRecvDataSegmentLength;187		} else {188			dr->read_data_done +=189				(conn->sess->sess_ops->MaxBurstLength -190				 dr->next_burst_len);191			dr->next_burst_len = 0;192			pdu_start += data_sn_count;193			data_sn_count = 0;194			seq_no++;195		}196	}197 198	if (!conn->sess->sess_ops->DataPDUInOrder) {199		cmd->seq_no = seq_no;200		cmd->pdu_start = pdu_start;201		cmd->pdu_send_order = data_sn_count;202	}203 204	return 0;205}206 207/*208 *	Generates Offsets and NextBurstLength based on Begrun and Runlength209 *	carried in a Data SNACK or ExpDataSN in TMR TASK_REASSIGN.210 *211 *	For DataSequenceInOrder=No and DataPDUInOrder=[Yes,No] only.212 *213 *	FIXME: How is this handled for a RData SNACK?214 */215int iscsit_create_recovery_datain_values_datasequenceinorder_no(216	struct iscsit_cmd *cmd,217	struct iscsi_datain_req *dr)218{219	int found_seq = 0, i;220	u32 data_sn, read_data_done = 0, seq_send_order = 0;221	u32 begrun = dr->begrun;222	u32 runlength = dr->runlength;223	struct iscsit_conn *conn = cmd->conn;224	struct iscsi_seq *first_seq = NULL, *seq = NULL;225 226	if (!cmd->seq_list) {227		pr_err("struct iscsit_cmd->seq_list is NULL!\n");228		return -1;229	}230 231	/*232	 * Calculate read_data_done for all sequences containing a233	 * first_datasn and last_datasn less than the BegRun.234	 *235	 * Locate the struct iscsi_seq the BegRun lies within and calculate236	 * NextBurstLenghth up to the DataSN based on MaxRecvDataSegmentLength.237	 *238	 * Also use struct iscsi_seq->seq_send_order to determine where to start.239	 */240	for (i = 0; i < cmd->seq_count; i++) {241		seq = &cmd->seq_list[i];242 243		if (!seq->seq_send_order)244			first_seq = seq;245 246		/*247		 * No data has been transferred for this DataIN sequence, so the248		 * seq->first_datasn and seq->last_datasn have not been set.249		 */250		if (!seq->sent) {251			pr_err("Ignoring non-sent sequence 0x%08x ->"252				" 0x%08x\n\n", seq->first_datasn,253				seq->last_datasn);254			continue;255		}256 257		/*258		 * This DataIN sequence is precedes the received BegRun, add the259		 * total xfer_len of the sequence to read_data_done and reset260		 * seq->pdu_send_order.261		 */262		if ((seq->first_datasn < begrun) &&263				(seq->last_datasn < begrun)) {264			pr_err("Pre BegRun sequence 0x%08x ->"265				" 0x%08x\n", seq->first_datasn,266				seq->last_datasn);267 268			read_data_done += cmd->seq_list[i].xfer_len;269			seq->next_burst_len = seq->pdu_send_order = 0;270			continue;271		}272 273		/*274		 * The BegRun lies within this DataIN sequence.275		 */276		if ((seq->first_datasn <= begrun) &&277				(seq->last_datasn >= begrun)) {278			pr_err("Found sequence begrun: 0x%08x in"279				" 0x%08x -> 0x%08x\n", begrun,280				seq->first_datasn, seq->last_datasn);281 282			seq_send_order = seq->seq_send_order;283			data_sn = seq->first_datasn;284			seq->next_burst_len = seq->pdu_send_order = 0;285			found_seq = 1;286 287			/*288			 * For DataPDUInOrder=Yes, while the first DataSN of289			 * the sequence is less than the received BegRun, add290			 * the MaxRecvDataSegmentLength to read_data_done and291			 * to the sequence's next_burst_len;292			 *293			 * For DataPDUInOrder=No, while the first DataSN of the294			 * sequence is less than the received BegRun, find the295			 * struct iscsi_pdu of the DataSN in question and add the296			 * MaxRecvDataSegmentLength to read_data_done and to the297			 * sequence's next_burst_len;298			 */299			if (conn->sess->sess_ops->DataPDUInOrder) {300				while (data_sn < begrun) {301					seq->pdu_send_order++;302					read_data_done +=303						conn->conn_ops->MaxRecvDataSegmentLength;304					seq->next_burst_len +=305						conn->conn_ops->MaxRecvDataSegmentLength;306					data_sn++;307				}308			} else {309				int j;310				struct iscsi_pdu *pdu;311 312				while (data_sn < begrun) {313					seq->pdu_send_order++;314 315					for (j = 0; j < seq->pdu_count; j++) {316						pdu = &cmd->pdu_list[317							seq->pdu_start + j];318						if (pdu->data_sn == data_sn) {319							read_data_done +=320								pdu->length;321							seq->next_burst_len +=322								pdu->length;323						}324					}325					data_sn++;326				}327			}328			continue;329		}330 331		/*332		 * This DataIN sequence is larger than the received BegRun,333		 * reset seq->pdu_send_order and continue.334		 */335		if ((seq->first_datasn > begrun) ||336				(seq->last_datasn > begrun)) {337			pr_err("Post BegRun sequence 0x%08x -> 0x%08x\n",338					seq->first_datasn, seq->last_datasn);339 340			seq->next_burst_len = seq->pdu_send_order = 0;341			continue;342		}343	}344 345	if (!found_seq) {346		if (!begrun) {347			if (!first_seq) {348				pr_err("ITT: 0x%08x, Begrun: 0x%08x"349					" but first_seq is NULL\n",350					cmd->init_task_tag, begrun);351				return -1;352			}353			seq_send_order = first_seq->seq_send_order;354			seq->next_burst_len = seq->pdu_send_order = 0;355			goto done;356		}357 358		pr_err("Unable to locate struct iscsi_seq for ITT: 0x%08x,"359			" BegRun: 0x%08x, RunLength: 0x%08x while"360			" DataSequenceInOrder=No and DataPDUInOrder=%s.\n",361				cmd->init_task_tag, begrun, runlength,362			(conn->sess->sess_ops->DataPDUInOrder) ? "Yes" : "No");363		return -1;364	}365 366done:367	dr->read_data_done = read_data_done;368	dr->seq_send_order = seq_send_order;369 370	return 0;371}372 373static int iscsit_handle_recovery_datain(374	struct iscsit_cmd *cmd,375	unsigned char *buf,376	u32 begrun,377	u32 runlength)378{379	struct iscsit_conn *conn = cmd->conn;380	struct iscsi_datain_req *dr;381	struct se_cmd *se_cmd = &cmd->se_cmd;382 383	if (!(se_cmd->transport_state & CMD_T_COMPLETE)) {384		pr_err("Ignoring ITT: 0x%08x Data SNACK\n",385				cmd->init_task_tag);386		return 0;387	}388 389	/*390	 * Make sure the initiator is not requesting retransmission391	 * of DataSNs already acknowledged by a Data ACK SNACK.392	 */393	if ((cmd->cmd_flags & ICF_GOT_DATACK_SNACK) &&394	    (begrun <= cmd->acked_data_sn)) {395		pr_err("ITT: 0x%08x, Data SNACK requesting"396			" retransmission of DataSN: 0x%08x to 0x%08x but"397			" already acked to DataSN: 0x%08x by Data ACK SNACK,"398			" protocol error.\n", cmd->init_task_tag, begrun,399			(begrun + runlength), cmd->acked_data_sn);400 401		return iscsit_reject_cmd(cmd, ISCSI_REASON_PROTOCOL_ERROR, buf);402	}403 404	/*405	 * Make sure BegRun and RunLength in the Data SNACK are sane.406	 * Note: (cmd->data_sn - 1) will carry the maximum DataSN sent.407	 */408	if ((begrun + runlength) > (cmd->data_sn - 1)) {409		pr_err("Initiator requesting BegRun: 0x%08x, RunLength"410			": 0x%08x greater than maximum DataSN: 0x%08x.\n",411				begrun, runlength, (cmd->data_sn - 1));412		return iscsit_reject_cmd(cmd, ISCSI_REASON_BOOKMARK_INVALID,413					 buf);414	}415 416	dr = iscsit_allocate_datain_req();417	if (!dr)418		return iscsit_reject_cmd(cmd, ISCSI_REASON_BOOKMARK_NO_RESOURCES,419					 buf);420 421	dr->data_sn = dr->begrun = begrun;422	dr->runlength = runlength;423	dr->generate_recovery_values = 1;424	dr->recovery = DATAIN_WITHIN_COMMAND_RECOVERY;425 426	iscsit_attach_datain_req(cmd, dr);427 428	cmd->i_state = ISTATE_SEND_DATAIN;429	iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);430 431	return 0;432}433 434int iscsit_handle_recovery_datain_or_r2t(435	struct iscsit_conn *conn,436	unsigned char *buf,437	itt_t init_task_tag,438	u32 targ_xfer_tag,439	u32 begrun,440	u32 runlength)441{442	struct iscsit_cmd *cmd;443 444	cmd = iscsit_find_cmd_from_itt(conn, init_task_tag);445	if (!cmd)446		return 0;447 448	/*449	 * FIXME: This will not work for bidi commands.450	 */451	switch (cmd->data_direction) {452	case DMA_TO_DEVICE:453		return iscsit_handle_r2t_snack(cmd, buf, begrun, runlength);454	case DMA_FROM_DEVICE:455		return iscsit_handle_recovery_datain(cmd, buf, begrun,456				runlength);457	default:458		pr_err("Unknown cmd->data_direction: 0x%02x\n",459				cmd->data_direction);460		return -1;461	}462 463	return 0;464}465 466/* #warning FIXME: Status SNACK needs to be dependent on OPCODE!!! */467int iscsit_handle_status_snack(468	struct iscsit_conn *conn,469	itt_t init_task_tag,470	u32 targ_xfer_tag,471	u32 begrun,472	u32 runlength)473{474	struct iscsit_cmd *cmd = NULL;475	u32 last_statsn;476	int found_cmd;477 478	if (!begrun) {479		begrun = conn->exp_statsn;480	} else if (conn->exp_statsn > begrun) {481		pr_err("Got Status SNACK Begrun: 0x%08x, RunLength:"482			" 0x%08x but already got ExpStatSN: 0x%08x on CID:"483			" %hu.\n", begrun, runlength, conn->exp_statsn,484			conn->cid);485		return 0;486	}487 488	last_statsn = (!runlength) ? conn->stat_sn : (begrun + runlength);489 490	while (begrun < last_statsn) {491		found_cmd = 0;492 493		spin_lock_bh(&conn->cmd_lock);494		list_for_each_entry(cmd, &conn->conn_cmd_list, i_conn_node) {495			if (cmd->stat_sn == begrun) {496				found_cmd = 1;497				break;498			}499		}500		spin_unlock_bh(&conn->cmd_lock);501 502		if (!found_cmd) {503			pr_err("Unable to find StatSN: 0x%08x for"504				" a Status SNACK, assuming this was a"505				" protactic SNACK for an untransmitted"506				" StatSN, ignoring.\n", begrun);507			begrun++;508			continue;509		}510 511		spin_lock_bh(&cmd->istate_lock);512		if (cmd->i_state == ISTATE_SEND_DATAIN) {513			spin_unlock_bh(&cmd->istate_lock);514			pr_err("Ignoring Status SNACK for BegRun:"515				" 0x%08x, RunLength: 0x%08x, assuming this was"516				" a protactic SNACK for an untransmitted"517				" StatSN\n", begrun, runlength);518			begrun++;519			continue;520		}521		spin_unlock_bh(&cmd->istate_lock);522 523		cmd->i_state = ISTATE_SEND_STATUS_RECOVERY;524		iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);525		begrun++;526	}527 528	return 0;529}530 531int iscsit_handle_data_ack(532	struct iscsit_conn *conn,533	u32 targ_xfer_tag,534	u32 begrun,535	u32 runlength)536{537	struct iscsit_cmd *cmd = NULL;538 539	cmd = iscsit_find_cmd_from_ttt(conn, targ_xfer_tag);540	if (!cmd) {541		pr_err("Data ACK SNACK for TTT: 0x%08x is"542			" invalid.\n", targ_xfer_tag);543		return -1;544	}545 546	if (begrun <= cmd->acked_data_sn) {547		pr_err("ITT: 0x%08x Data ACK SNACK BegRUN: 0x%08x is"548			" less than the already acked DataSN: 0x%08x.\n",549			cmd->init_task_tag, begrun, cmd->acked_data_sn);550		return -1;551	}552 553	/*554	 * For Data ACK SNACK, BegRun is the next expected DataSN.555	 * (see iSCSI v19: 10.16.6)556	 */557	cmd->cmd_flags |= ICF_GOT_DATACK_SNACK;558	cmd->acked_data_sn = (begrun - 1);559 560	pr_debug("Received Data ACK SNACK for ITT: 0x%08x,"561		" updated acked DataSN to 0x%08x.\n",562			cmd->init_task_tag, cmd->acked_data_sn);563 564	return 0;565}566 567static int iscsit_send_recovery_r2t(568	struct iscsit_cmd *cmd,569	u32 offset,570	u32 xfer_len)571{572	int ret;573 574	spin_lock_bh(&cmd->r2t_lock);575	ret = iscsit_add_r2t_to_list(cmd, offset, xfer_len, 1, 0);576	spin_unlock_bh(&cmd->r2t_lock);577 578	return ret;579}580 581int iscsit_dataout_datapduinorder_no_fbit(582	struct iscsit_cmd *cmd,583	struct iscsi_pdu *pdu)584{585	int i, send_recovery_r2t = 0, recovery = 0;586	u32 length = 0, offset = 0, pdu_count = 0;587	struct iscsit_conn *conn = cmd->conn;588	struct iscsi_pdu *first_pdu = NULL;589 590	/*591	 * Get an struct iscsi_pdu pointer to the first PDU, and total PDU count592	 * of the DataOUT sequence.593	 */594	if (conn->sess->sess_ops->DataSequenceInOrder) {595		for (i = 0; i < cmd->pdu_count; i++) {596			if (cmd->pdu_list[i].seq_no == pdu->seq_no) {597				if (!first_pdu)598					first_pdu = &cmd->pdu_list[i];599				pdu_count++;600			} else if (pdu_count)601				break;602		}603	} else {604		struct iscsi_seq *seq = cmd->seq_ptr;605 606		first_pdu = &cmd->pdu_list[seq->pdu_start];607		pdu_count = seq->pdu_count;608	}609 610	if (!first_pdu || !pdu_count)611		return DATAOUT_CANNOT_RECOVER;612 613	/*614	 * Loop through the ending DataOUT Sequence checking each struct iscsi_pdu.615	 * The following ugly logic does batching of not received PDUs.616	 */617	for (i = 0; i < pdu_count; i++) {618		if (first_pdu[i].status == ISCSI_PDU_RECEIVED_OK) {619			if (!send_recovery_r2t)620				continue;621 622			if (iscsit_send_recovery_r2t(cmd, offset, length) < 0)623				return DATAOUT_CANNOT_RECOVER;624 625			send_recovery_r2t = length = offset = 0;626			continue;627		}628		/*629		 * Set recovery = 1 for any missing, CRC failed, or timed630		 * out PDUs to let the DataOUT logic know that this sequence631		 * has not been completed yet.632		 *633		 * Also, only send a Recovery R2T for ISCSI_PDU_NOT_RECEIVED.634		 * We assume if the PDU either failed CRC or timed out635		 * that a Recovery R2T has already been sent.636		 */637		recovery = 1;638 639		if (first_pdu[i].status != ISCSI_PDU_NOT_RECEIVED)640			continue;641 642		if (!offset)643			offset = first_pdu[i].offset;644		length += first_pdu[i].length;645 646		send_recovery_r2t = 1;647	}648 649	if (send_recovery_r2t)650		if (iscsit_send_recovery_r2t(cmd, offset, length) < 0)651			return DATAOUT_CANNOT_RECOVER;652 653	return (!recovery) ? DATAOUT_NORMAL : DATAOUT_WITHIN_COMMAND_RECOVERY;654}655 656static int iscsit_recalculate_dataout_values(657	struct iscsit_cmd *cmd,658	u32 pdu_offset,659	u32 pdu_length,660	u32 *r2t_offset,661	u32 *r2t_length)662{663	int i;664	struct iscsit_conn *conn = cmd->conn;665	struct iscsi_pdu *pdu = NULL;666 667	if (conn->sess->sess_ops->DataSequenceInOrder) {668		cmd->data_sn = 0;669 670		if (conn->sess->sess_ops->DataPDUInOrder) {671			*r2t_offset = cmd->write_data_done;672			*r2t_length = (cmd->seq_end_offset -673					cmd->write_data_done);674			return 0;675		}676 677		*r2t_offset = cmd->seq_start_offset;678		*r2t_length = (cmd->seq_end_offset - cmd->seq_start_offset);679 680		for (i = 0; i < cmd->pdu_count; i++) {681			pdu = &cmd->pdu_list[i];682 683			if (pdu->status != ISCSI_PDU_RECEIVED_OK)684				continue;685 686			if ((pdu->offset >= cmd->seq_start_offset) &&687			   ((pdu->offset + pdu->length) <=688			     cmd->seq_end_offset)) {689				if (!cmd->unsolicited_data)690					cmd->next_burst_len -= pdu->length;691				else692					cmd->first_burst_len -= pdu->length;693 694				cmd->write_data_done -= pdu->length;695				pdu->status = ISCSI_PDU_NOT_RECEIVED;696			}697		}698	} else {699		struct iscsi_seq *seq = NULL;700 701		seq = iscsit_get_seq_holder(cmd, pdu_offset, pdu_length);702		if (!seq)703			return -1;704 705		*r2t_offset = seq->orig_offset;706		*r2t_length = seq->xfer_len;707 708		cmd->write_data_done -= (seq->offset - seq->orig_offset);709		if (cmd->immediate_data)710			cmd->first_burst_len = cmd->write_data_done;711 712		seq->data_sn = 0;713		seq->offset = seq->orig_offset;714		seq->next_burst_len = 0;715		seq->status = DATAOUT_SEQUENCE_WITHIN_COMMAND_RECOVERY;716 717		if (conn->sess->sess_ops->DataPDUInOrder)718			return 0;719 720		for (i = 0; i < seq->pdu_count; i++) {721			pdu = &cmd->pdu_list[i+seq->pdu_start];722 723			if (pdu->status != ISCSI_PDU_RECEIVED_OK)724				continue;725 726			pdu->status = ISCSI_PDU_NOT_RECEIVED;727		}728	}729 730	return 0;731}732 733int iscsit_recover_dataout_sequence(734	struct iscsit_cmd *cmd,735	u32 pdu_offset,736	u32 pdu_length)737{738	u32 r2t_length = 0, r2t_offset = 0;739 740	spin_lock_bh(&cmd->istate_lock);741	cmd->cmd_flags |= ICF_WITHIN_COMMAND_RECOVERY;742	spin_unlock_bh(&cmd->istate_lock);743 744	if (iscsit_recalculate_dataout_values(cmd, pdu_offset, pdu_length,745			&r2t_offset, &r2t_length) < 0)746		return DATAOUT_CANNOT_RECOVER;747 748	iscsit_send_recovery_r2t(cmd, r2t_offset, r2t_length);749 750	return DATAOUT_WITHIN_COMMAND_RECOVERY;751}752 753static struct iscsi_ooo_cmdsn *iscsit_allocate_ooo_cmdsn(void)754{755	struct iscsi_ooo_cmdsn *ooo_cmdsn = NULL;756 757	ooo_cmdsn = kmem_cache_zalloc(lio_ooo_cache, GFP_ATOMIC);758	if (!ooo_cmdsn) {759		pr_err("Unable to allocate memory for"760			" struct iscsi_ooo_cmdsn.\n");761		return NULL;762	}763	INIT_LIST_HEAD(&ooo_cmdsn->ooo_list);764 765	return ooo_cmdsn;766}767 768static int iscsit_attach_ooo_cmdsn(769	struct iscsit_session *sess,770	struct iscsi_ooo_cmdsn *ooo_cmdsn)771{772	struct iscsi_ooo_cmdsn *ooo_tail, *ooo_tmp;773 774	lockdep_assert_held(&sess->cmdsn_mutex);775 776	/*777	 * We attach the struct iscsi_ooo_cmdsn entry to the out of order778	 * list in increasing CmdSN order.779	 * This allows iscsi_execute_ooo_cmdsns() to detect any780	 * additional CmdSN holes while performing delayed execution.781	 */782	if (list_empty(&sess->sess_ooo_cmdsn_list))783		list_add_tail(&ooo_cmdsn->ooo_list,784				&sess->sess_ooo_cmdsn_list);785	else {786		ooo_tail = list_entry(sess->sess_ooo_cmdsn_list.prev,787				typeof(*ooo_tail), ooo_list);788		/*789		 * CmdSN is greater than the tail of the list.790		 */791		if (iscsi_sna_lt(ooo_tail->cmdsn, ooo_cmdsn->cmdsn))792			list_add_tail(&ooo_cmdsn->ooo_list,793					&sess->sess_ooo_cmdsn_list);794		else {795			/*796			 * CmdSN is either lower than the head,  or somewhere797			 * in the middle.798			 */799			list_for_each_entry(ooo_tmp, &sess->sess_ooo_cmdsn_list,800						ooo_list) {801				if (iscsi_sna_lt(ooo_tmp->cmdsn, ooo_cmdsn->cmdsn))802					continue;803 804				/* Insert before this entry */805				list_add(&ooo_cmdsn->ooo_list,806					ooo_tmp->ooo_list.prev);807				break;808			}809		}810	}811 812	return 0;813}814 815/*816 *	Removes an struct iscsi_ooo_cmdsn from a session's list,817 *	called with struct iscsit_session->cmdsn_mutex held.818 */819void iscsit_remove_ooo_cmdsn(820	struct iscsit_session *sess,821	struct iscsi_ooo_cmdsn *ooo_cmdsn)822{823	list_del(&ooo_cmdsn->ooo_list);824	kmem_cache_free(lio_ooo_cache, ooo_cmdsn);825}826 827void iscsit_clear_ooo_cmdsns_for_conn(struct iscsit_conn *conn)828{829	struct iscsi_ooo_cmdsn *ooo_cmdsn;830	struct iscsit_session *sess = conn->sess;831 832	mutex_lock(&sess->cmdsn_mutex);833	list_for_each_entry(ooo_cmdsn, &sess->sess_ooo_cmdsn_list, ooo_list) {834		if (ooo_cmdsn->cid != conn->cid)835			continue;836 837		ooo_cmdsn->cmd = NULL;838	}839	mutex_unlock(&sess->cmdsn_mutex);840}841 842int iscsit_execute_ooo_cmdsns(struct iscsit_session *sess)843{844	int ooo_count = 0;845	struct iscsit_cmd *cmd = NULL;846	struct iscsi_ooo_cmdsn *ooo_cmdsn, *ooo_cmdsn_tmp;847 848	lockdep_assert_held(&sess->cmdsn_mutex);849 850	list_for_each_entry_safe(ooo_cmdsn, ooo_cmdsn_tmp,851				&sess->sess_ooo_cmdsn_list, ooo_list) {852		if (ooo_cmdsn->cmdsn != sess->exp_cmd_sn)853			continue;854 855		if (!ooo_cmdsn->cmd) {856			sess->exp_cmd_sn++;857			iscsit_remove_ooo_cmdsn(sess, ooo_cmdsn);858			continue;859		}860 861		cmd = ooo_cmdsn->cmd;862		cmd->i_state = cmd->deferred_i_state;863		ooo_count++;864		sess->exp_cmd_sn++;865		pr_debug("Executing out of order CmdSN: 0x%08x,"866			" incremented ExpCmdSN to 0x%08x.\n",867			cmd->cmd_sn, sess->exp_cmd_sn);868 869		iscsit_remove_ooo_cmdsn(sess, ooo_cmdsn);870 871		if (iscsit_execute_cmd(cmd, 1) < 0)872			return -1;873	}874 875	return ooo_count;876}877 878/*879 *	Called either:880 *881 *	1. With sess->cmdsn_mutex held from iscsi_execute_ooo_cmdsns()882 *	or iscsi_check_received_cmdsn().883 *	2. With no locks held directly from iscsi_handle_XXX_pdu() functions884 *	for immediate commands.885 */886int iscsit_execute_cmd(struct iscsit_cmd *cmd, int ooo)887{888	struct se_cmd *se_cmd = &cmd->se_cmd;889	struct iscsit_conn *conn = cmd->conn;890	int lr = 0;891 892	spin_lock_bh(&cmd->istate_lock);893	if (ooo)894		cmd->cmd_flags &= ~ICF_OOO_CMDSN;895 896	switch (cmd->iscsi_opcode) {897	case ISCSI_OP_SCSI_CMD:898		/*899		 * Go ahead and send the CHECK_CONDITION status for900		 * any SCSI CDB exceptions that may have occurred.901		 */902		if (cmd->sense_reason) {903			if (cmd->sense_reason == TCM_RESERVATION_CONFLICT) {904				cmd->i_state = ISTATE_SEND_STATUS;905				spin_unlock_bh(&cmd->istate_lock);906				iscsit_add_cmd_to_response_queue(cmd, cmd->conn,907						cmd->i_state);908				return 0;909			}910			spin_unlock_bh(&cmd->istate_lock);911			if (cmd->se_cmd.transport_state & CMD_T_ABORTED)912				return 0;913			return transport_send_check_condition_and_sense(se_cmd,914					cmd->sense_reason, 0);915		}916		/*917		 * Special case for delayed CmdSN with Immediate918		 * Data and/or Unsolicited Data Out attached.919		 */920		if (cmd->immediate_data) {921			if (cmd->cmd_flags & ICF_GOT_LAST_DATAOUT) {922				spin_unlock_bh(&cmd->istate_lock);923				target_execute_cmd(&cmd->se_cmd);924				return 0;925			}926			spin_unlock_bh(&cmd->istate_lock);927 928			if (!(cmd->cmd_flags &929					ICF_NON_IMMEDIATE_UNSOLICITED_DATA)) {930				if (cmd->se_cmd.transport_state & CMD_T_ABORTED)931					return 0;932 933				iscsit_set_dataout_sequence_values(cmd);934				conn->conn_transport->iscsit_get_dataout(conn, cmd, false);935			}936			return 0;937		}938		/*939		 * The default handler.940		 */941		spin_unlock_bh(&cmd->istate_lock);942 943		if ((cmd->data_direction == DMA_TO_DEVICE) &&944		    !(cmd->cmd_flags & ICF_NON_IMMEDIATE_UNSOLICITED_DATA)) {945			if (cmd->se_cmd.transport_state & CMD_T_ABORTED)946				return 0;947 948			iscsit_set_unsolicited_dataout(cmd);949		}950		return target_submit(&cmd->se_cmd);951 952	case ISCSI_OP_NOOP_OUT:953	case ISCSI_OP_TEXT:954		spin_unlock_bh(&cmd->istate_lock);955		iscsit_add_cmd_to_response_queue(cmd, cmd->conn, cmd->i_state);956		break;957	case ISCSI_OP_SCSI_TMFUNC:958		if (cmd->se_cmd.se_tmr_req->response) {959			spin_unlock_bh(&cmd->istate_lock);960			iscsit_add_cmd_to_response_queue(cmd, cmd->conn,961					cmd->i_state);962			return 0;963		}964		spin_unlock_bh(&cmd->istate_lock);965 966		return transport_generic_handle_tmr(&cmd->se_cmd);967	case ISCSI_OP_LOGOUT:968		spin_unlock_bh(&cmd->istate_lock);969		switch (cmd->logout_reason) {970		case ISCSI_LOGOUT_REASON_CLOSE_SESSION:971			lr = iscsit_logout_closesession(cmd, cmd->conn);972			break;973		case ISCSI_LOGOUT_REASON_CLOSE_CONNECTION:974			lr = iscsit_logout_closeconnection(cmd, cmd->conn);975			break;976		case ISCSI_LOGOUT_REASON_RECOVERY:977			lr = iscsit_logout_removeconnforrecovery(cmd, cmd->conn);978			break;979		default:980			pr_err("Unknown iSCSI Logout Request Code:"981				" 0x%02x\n", cmd->logout_reason);982			return -1;983		}984 985		return lr;986	default:987		spin_unlock_bh(&cmd->istate_lock);988		pr_err("Cannot perform out of order execution for"989		" unknown iSCSI Opcode: 0x%02x\n", cmd->iscsi_opcode);990		return -1;991	}992 993	return 0;994}995 996void iscsit_free_all_ooo_cmdsns(struct iscsit_session *sess)997{998	struct iscsi_ooo_cmdsn *ooo_cmdsn, *ooo_cmdsn_tmp;999 1000	mutex_lock(&sess->cmdsn_mutex);1001	list_for_each_entry_safe(ooo_cmdsn, ooo_cmdsn_tmp,1002			&sess->sess_ooo_cmdsn_list, ooo_list) {1003 1004		list_del(&ooo_cmdsn->ooo_list);1005		kmem_cache_free(lio_ooo_cache, ooo_cmdsn);1006	}1007	mutex_unlock(&sess->cmdsn_mutex);1008}1009 1010int iscsit_handle_ooo_cmdsn(1011	struct iscsit_session *sess,1012	struct iscsit_cmd *cmd,1013	u32 cmdsn)1014{1015	int batch = 0;1016	struct iscsi_ooo_cmdsn *ooo_cmdsn = NULL, *ooo_tail = NULL;1017 1018	cmd->deferred_i_state		= cmd->i_state;1019	cmd->i_state			= ISTATE_DEFERRED_CMD;1020	cmd->cmd_flags			|= ICF_OOO_CMDSN;1021 1022	if (list_empty(&sess->sess_ooo_cmdsn_list))1023		batch = 1;1024	else {1025		ooo_tail = list_entry(sess->sess_ooo_cmdsn_list.prev,1026				typeof(*ooo_tail), ooo_list);1027		if (ooo_tail->cmdsn != (cmdsn - 1))1028			batch = 1;1029	}1030 1031	ooo_cmdsn = iscsit_allocate_ooo_cmdsn();1032	if (!ooo_cmdsn)1033		return -ENOMEM;1034 1035	ooo_cmdsn->cmd			= cmd;1036	ooo_cmdsn->batch_count		= (batch) ?1037					  (cmdsn - sess->exp_cmd_sn) : 1;1038	ooo_cmdsn->cid			= cmd->conn->cid;1039	ooo_cmdsn->exp_cmdsn		= sess->exp_cmd_sn;1040	ooo_cmdsn->cmdsn		= cmdsn;1041 1042	if (iscsit_attach_ooo_cmdsn(sess, ooo_cmdsn) < 0) {1043		kmem_cache_free(lio_ooo_cache, ooo_cmdsn);1044		return -ENOMEM;1045	}1046 1047	return 0;1048}1049 1050static int iscsit_set_dataout_timeout_values(1051	struct iscsit_cmd *cmd,1052	u32 *offset,1053	u32 *length)1054{1055	struct iscsit_conn *conn = cmd->conn;1056	struct iscsi_r2t *r2t;1057 1058	if (cmd->unsolicited_data) {1059		*offset = 0;1060		*length = (conn->sess->sess_ops->FirstBurstLength >1061			   cmd->se_cmd.data_length) ?1062			   cmd->se_cmd.data_length :1063			   conn->sess->sess_ops->FirstBurstLength;1064		return 0;1065	}1066 1067	spin_lock_bh(&cmd->r2t_lock);1068	if (list_empty(&cmd->cmd_r2t_list)) {1069		pr_err("cmd->cmd_r2t_list is empty!\n");1070		spin_unlock_bh(&cmd->r2t_lock);1071		return -1;1072	}1073 1074	list_for_each_entry(r2t, &cmd->cmd_r2t_list, r2t_list) {1075		if (r2t->sent_r2t && !r2t->recovery_r2t && !r2t->seq_complete) {1076			*offset = r2t->offset;1077			*length = r2t->xfer_len;1078			spin_unlock_bh(&cmd->r2t_lock);1079			return 0;1080		}1081	}1082	spin_unlock_bh(&cmd->r2t_lock);1083 1084	pr_err("Unable to locate any incomplete DataOUT"1085		" sequences for ITT: 0x%08x.\n", cmd->init_task_tag);1086 1087	return -1;1088}1089 1090/*1091 *	NOTE: Called from interrupt (timer) context.1092 */1093void iscsit_handle_dataout_timeout(struct timer_list *t)1094{1095	u32 pdu_length = 0, pdu_offset = 0;1096	u32 r2t_length = 0, r2t_offset = 0;1097	struct iscsit_cmd *cmd = from_timer(cmd, t, dataout_timer);1098	struct iscsit_conn *conn = cmd->conn;1099	struct iscsit_session *sess = NULL;1100	struct iscsi_node_attrib *na;1101 1102	iscsit_inc_conn_usage_count(conn);1103 1104	spin_lock_bh(&cmd->dataout_timeout_lock);1105	if (cmd->dataout_timer_flags & ISCSI_TF_STOP) {1106		spin_unlock_bh(&cmd->dataout_timeout_lock);1107		iscsit_dec_conn_usage_count(conn);1108		return;1109	}1110	cmd->dataout_timer_flags &= ~ISCSI_TF_RUNNING;1111	sess = conn->sess;1112	na = iscsit_tpg_get_node_attrib(sess);1113 1114	if (!sess->sess_ops->ErrorRecoveryLevel) {1115		pr_err("Unable to recover from DataOut timeout while"1116			" in ERL=0, closing iSCSI connection for I_T Nexus"1117			" %s,i,0x%6phN,%s,t,0x%02x\n",1118			sess->sess_ops->InitiatorName, sess->isid,1119			sess->tpg->tpg_tiqn->tiqn, (u32)sess->tpg->tpgt);1120		goto failure;1121	}1122 1123	if (++cmd->dataout_timeout_retries == na->dataout_timeout_retries) {1124		pr_err("Command ITT: 0x%08x exceeded max retries"1125			" for DataOUT timeout %u, closing iSCSI connection for"1126			" I_T Nexus %s,i,0x%6phN,%s,t,0x%02x\n",1127			cmd->init_task_tag, na->dataout_timeout_retries,1128			sess->sess_ops->InitiatorName, sess->isid,1129			sess->tpg->tpg_tiqn->tiqn, (u32)sess->tpg->tpgt);1130		goto failure;1131	}1132 1133	cmd->cmd_flags |= ICF_WITHIN_COMMAND_RECOVERY;1134 1135	if (conn->sess->sess_ops->DataSequenceInOrder) {1136		if (conn->sess->sess_ops->DataPDUInOrder) {1137			pdu_offset = cmd->write_data_done;1138			if ((pdu_offset + (conn->sess->sess_ops->MaxBurstLength -1139			     cmd->next_burst_len)) > cmd->se_cmd.data_length)1140				pdu_length = (cmd->se_cmd.data_length -1141					cmd->write_data_done);1142			else1143				pdu_length = (conn->sess->sess_ops->MaxBurstLength -1144						cmd->next_burst_len);1145		} else {1146			pdu_offset = cmd->seq_start_offset;1147			pdu_length = (cmd->seq_end_offset -1148				cmd->seq_start_offset);1149		}1150	} else {1151		if (iscsit_set_dataout_timeout_values(cmd, &pdu_offset,1152				&pdu_length) < 0)1153			goto failure;1154	}1155 1156	if (iscsit_recalculate_dataout_values(cmd, pdu_offset, pdu_length,1157			&r2t_offset, &r2t_length) < 0)1158		goto failure;1159 1160	pr_debug("Command ITT: 0x%08x timed out waiting for"1161		" completion of %sDataOUT Sequence Offset: %u, Length: %u\n",1162		cmd->init_task_tag, (cmd->unsolicited_data) ? "Unsolicited " :1163		"", r2t_offset, r2t_length);1164 1165	if (iscsit_send_recovery_r2t(cmd, r2t_offset, r2t_length) < 0)1166		goto failure;1167 1168	iscsit_start_dataout_timer(cmd, conn);1169	spin_unlock_bh(&cmd->dataout_timeout_lock);1170	iscsit_dec_conn_usage_count(conn);1171 1172	return;1173 1174failure:1175	spin_unlock_bh(&cmd->dataout_timeout_lock);1176	iscsit_fill_cxn_timeout_err_stats(sess);1177	iscsit_cause_connection_reinstatement(conn, 0);1178	iscsit_dec_conn_usage_count(conn);1179}1180 1181void iscsit_mod_dataout_timer(struct iscsit_cmd *cmd)1182{1183	struct iscsit_conn *conn = cmd->conn;1184	struct iscsit_session *sess = conn->sess;1185	struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);1186 1187	spin_lock_bh(&cmd->dataout_timeout_lock);1188	if (!(cmd->dataout_timer_flags & ISCSI_TF_RUNNING)) {1189		spin_unlock_bh(&cmd->dataout_timeout_lock);1190		return;1191	}1192 1193	mod_timer(&cmd->dataout_timer,1194		(get_jiffies_64() + na->dataout_timeout * HZ));1195	pr_debug("Updated DataOUT timer for ITT: 0x%08x",1196			cmd->init_task_tag);1197	spin_unlock_bh(&cmd->dataout_timeout_lock);1198}1199 1200void iscsit_start_dataout_timer(1201	struct iscsit_cmd *cmd,1202	struct iscsit_conn *conn)1203{1204	struct iscsit_session *sess = conn->sess;1205	struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);1206 1207	lockdep_assert_held(&cmd->dataout_timeout_lock);1208 1209	if (cmd->dataout_timer_flags & ISCSI_TF_RUNNING)1210		return;1211 1212	pr_debug("Starting DataOUT timer for ITT: 0x%08x on"1213		" CID: %hu.\n", cmd->init_task_tag, conn->cid);1214 1215	cmd->dataout_timer_flags &= ~ISCSI_TF_STOP;1216	cmd->dataout_timer_flags |= ISCSI_TF_RUNNING;1217	mod_timer(&cmd->dataout_timer, jiffies + na->dataout_timeout * HZ);1218}1219 1220void iscsit_stop_dataout_timer(struct iscsit_cmd *cmd)1221{1222	spin_lock_bh(&cmd->dataout_timeout_lock);1223	if (!(cmd->dataout_timer_flags & ISCSI_TF_RUNNING)) {1224		spin_unlock_bh(&cmd->dataout_timeout_lock);1225		return;1226	}1227	cmd->dataout_timer_flags |= ISCSI_TF_STOP;1228	spin_unlock_bh(&cmd->dataout_timeout_lock);1229 1230	del_timer_sync(&cmd->dataout_timer);1231 1232	spin_lock_bh(&cmd->dataout_timeout_lock);1233	cmd->dataout_timer_flags &= ~ISCSI_TF_RUNNING;1234	pr_debug("Stopped DataOUT Timer for ITT: 0x%08x\n",1235			cmd->init_task_tag);1236	spin_unlock_bh(&cmd->dataout_timeout_lock);1237}1238EXPORT_SYMBOL(iscsit_stop_dataout_timer);1239