drivers/pci

/*
 * iSCSI lib functions
 *
 * Copyright (C) 2006 Red Hat, Inc.  All rights reserved.
 * Copyright (C) 2004 - 2006 Mike Christie
 * Copyright (C) 2004 - 2005 Dmitry Yusupov
 * Copyright (C) 2004 - 2005 Alex Aizman
 * maintained by open-iscsi@googlegroups.com
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */
#include <linux/types.h>
#include <linux/mutex.h>
#include <linux/kfifo.h>
#include <linux/delay.h>
#include <net/tcp.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_eh.h>
#include <scsi/scsi_tcq.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi.h>
#include <scsi/iscsi_proto.h>
#include <scsi/scsi_transport.h>
#include <scsi/scsi_transport_iscsi.h>
#include <scsi/libiscsi.h>

struct iscsi_session *
class_to_transport_session(struct iscsi_cls_session *cls_session)
{
	struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
	return iscsi_hostdata(shost->hostdata);
}
EXPORT_SYMBOL_GPL(class_to_transport_session);

#define INVALID_SN_DELTA	0xffff

int
iscsi_check_assign_cmdsn(struct iscsi_session *session, struct iscsi_nopin *hdr)
{
	uint32_t max_cmdsn = be32_to_cpu(hdr->max_cmdsn);
	uint32_t exp_cmdsn = be32_to_cpu(hdr->exp_cmdsn);

	if (max_cmdsn < exp_cmdsn -1 &&
	    max_cmdsn > exp_cmdsn - INVALID_SN_DELTA)
		return ISCSI_ERR_MAX_CMDSN;
	if (max_cmdsn > session->max_cmdsn ||
	    max_cmdsn < session->max_cmdsn - INVALID_SN_DELTA)
		session->max_cmdsn = max_cmdsn;
	if (exp_cmdsn > session->exp_cmdsn ||
	    exp_cmdsn < session->exp_cmdsn - INVALID_SN_DELTA)
		session->exp_cmdsn = exp_cmdsn;

	return 0;
}
EXPORT_SYMBOL_GPL(iscsi_check_assign_cmdsn);

void iscsi_prep_unsolicit_data_pdu(struct iscsi_cmd_task *ctask,
				   struct iscsi_data *hdr,
				   int transport_data_cnt)
{
	struct iscsi_conn *conn = ctask->conn;

	memset(hdr, 0, sizeof(struct iscsi_data));
	hdr->ttt = cpu_to_be32(ISCSI_RESERVED_TAG);
	hdr->datasn = cpu_to_be32(ctask->unsol_datasn);
	ctask->unsol_datasn++;
	hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
	memcpy(hdr->lun, ctask->hdr->lun, sizeof(hdr->lun));

	hdr->itt = ctask->hdr->itt;
	hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);

	hdr->offset = cpu_to_be32(ctask->total_length -
				  transport_data_cnt -
				  ctask->unsol_count);

	if (ctask->unsol_count > conn->max_xmit_dlength) {
		hton24(hdr->dlength, conn->max_xmit_dlength);
		ctask->data_count = conn->max_xmit_dlength;
		hdr->flags = 0;
	} else {
		hton24(hdr->dlength, ctask->unsol_count);
		ctask->data_count = ctask->unsol_count;
		hdr->flags = ISCSI_FLAG_CMD_FINAL;
	}
}
EXPORT_SYMBOL_GPL(iscsi_prep_unsolicit_data_pdu);

/**
 * iscsi_prep_scsi_cmd_pdu - prep iscsi scsi cmd pdu
 * @ctask: iscsi cmd task
 *
 * Prep basic iSCSI PDU fields for a scsi cmd pdu. The LLD should set
 * fields like dlength or final based on how much data it sends
 */
static void iscsi_prep_scsi_cmd_pdu(struct iscsi_cmd_task *ctask)
{
	struct iscsi_conn *conn = ctask->conn;
	struct iscsi_session *session = conn->session;
	struct iscsi_cmd *hdr = ctask->hdr;
	struct scsi_cmnd *sc = ctask->sc;

        hdr->opcode = ISCSI_OP_SCSI_CMD;
        hdr->flags = ISCSI_ATTR_SIMPLE;
        int_to_scsilun(sc->device->lun, (struct scsi_lun *)hdr->lun);
        hdr->itt = ctask->itt | (conn->id << ISCSI_CID_SHIFT) |
                         (session->age << ISCSI_AGE_SHIFT);
        hdr->data_length = cpu_to_be32(sc->request_bufflen);
        hdr->cmdsn = cpu_to_be32(session->cmdsn);
        session->cmdsn++;
        hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
        memcpy(hdr->cdb, sc->cmnd, sc->cmd_len);
        memset(&hdr->cdb[sc->cmd_len], 0, MAX_COMMAND_SIZE - sc->cmd_len);

	if (sc->sc_data_direction == DMA_TO_DEVICE) {
		hdr->flags |= ISCSI_FLAG_CMD_WRITE;
		/*
		 * Write counters:
		 *
		 *	imm_count	bytes to be sent right after
		 *			SCSI PDU Header
		 *
		 *	unsol_count	bytes(as Data-Out) to be sent
		 *			without	R2T ack right after
		 *			immediate data
		 *
		 *	r2t_data_count	bytes to be sent via R2T ack's
		 *
		 *      pad_count       bytes to be sent as zero-padding
		 */
		ctask->imm_count = 0;
		ctask->unsol_count = 0;
		ctask->unsol_datasn = 0;

		if (session->imm_data_en) {
			if (ctask->total_length >= session->first_burst)
				ctask->imm_count = min(session->first_burst,
							conn->max_xmit_dlength);
			else
				ctask->imm_count = min(ctask->total_length,
							conn->max_xmit_dlength);
			hton24(ctask->hdr->dlength, ctask->imm_count);
		} else
			zero_data(ctask->hdr->dlength);

		if (!session->initial_r2t_en)
			ctask->unsol_count = min(session->first_burst,
				ctask->total_length) - ctask->imm_count;
		if (!ctask->unsol_count)
			/* No unsolicit Data-Out's */
			ctask->hdr->flags |= ISCSI_FLAG_CMD_FINAL;
	} else {
		ctask->datasn = 0;
		hdr->flags |= ISCSI_FLAG_CMD_FINAL;
		zero_data(hdr->dlength);

		if (sc->sc_data_direction == DMA_FROM_DEVICE)
			hdr->flags |= ISCSI_FLAG_CMD_READ;
	}

	conn->scsicmd_pdus_cnt++;
}
EXPORT_SYMBOL_GPL(iscsi_prep_scsi_cmd_pdu);

/**
 * iscsi_complete_command - return command back to scsi-ml
 * @session: iscsi session
 * @ctask: iscsi cmd task
 *
 * Must be called with session lock.
 * This function returns the scsi command to scsi-ml and returns
 * the cmd task to the pool of available cmd tasks.
 */
static void iscsi_complete_command(struct iscsi_session *session,
				   struct iscsi_cmd_task *ctask)
{
	struct scsi_cmnd *sc = ctask->sc;

	ctask->sc = NULL;
	list_del_init(&ctask->running);
	__kfifo_put(session->cmdpool.queue, (void*)&ctask, sizeof(void*));
	sc->scsi_done(sc);
}

/**
 * iscsi_cmd_rsp - SCSI Command Response processing
 * @conn: iscsi connection
 * @hdr: iscsi header
 * @ctask: scsi command task
 * @data: cmd data buffer
 * @datalen: len of buffer
 *
 * iscsi_cmd_rsp sets up the scsi_cmnd fields based on the PDU and
 * then completes the command and task.
 **/
static int iscsi_scsi_cmd_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
			      struct iscsi_cmd_task *ctask, char *data,
			      int datalen)
{
	int rc;
	struct iscsi_cmd_rsp *rhdr = (struct iscsi_cmd_rsp *)hdr;
	struct iscsi_session *session = conn->session;
	struct scsi_cmnd *sc = ctask->sc;

	rc = iscsi_check_assign_cmdsn(session, (struct iscsi_nopin*)rhdr);
	if (rc) {
		sc->result = DID_ERROR << 16;
		goto out;
	}

	conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;

	sc->result = (DID_OK << 16) | rhdr->cmd_status;

	if (rhdr->response != ISCSI_STATUS_CMD_COMPLETED) {
		sc->result = DID_ERROR << 16;
		goto out;
	}

	if (rhdr->cmd_status == SAM_STAT_CHECK_CONDITION) {
		int senselen;

		if (datalen < 2) {
invalid_datalen:
			printk(KERN_ERR "iscsi: Got CHECK_CONDITION but "
			       "invalid data buffer size of %d\n", datalen);
			sc->result = DID_BAD_TARGET << 16;
			goto out;
		}

		senselen = (data[0] << 8) | data[1];
		if (datalen < senselen)
			goto invalid_datalen;

		memcpy(sc->sense_buffer, data + 2,
		       min(senselen, SCSI_SENSE_BUFFERSIZE));
		debug_scsi("copied %d bytes of sense\n",
			   min(senselen, SCSI_SENSE_BUFFERSIZE));
	}

	if (sc->sc_data_direction == DMA_TO_DEVICE)
		goto out;

	if (rhdr->flags & ISCSI_FLAG_CMD_UNDERFLOW) {
		int res_count = be32_to_cpu(rhdr->residual_count);

		if (res_count > 0 && res_count <= sc->request_bufflen)
			sc->resid = res_count;
		else
			sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
	} else if (rhdr->flags & ISCSI_FLAG_CMD_BIDI_UNDERFLOW)
		sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
	else if (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW)
		sc->resid = be32_to_cpu(rhdr->residual_count);

out:
	debug_scsi("done [sc %lx res %d itt 0x%x]\n",
		   (long)sc, sc->result, ctask->itt);
	conn->scsirsp_pdus_cnt++;

	iscsi_complete_command(conn->session, ctask);
	return rc;
}

/**
 * __iscsi_complete_pdu - complete pdu
 * @conn: iscsi conn
 * @hdr: iscsi header
 * @data: data buffer
 * @datalen: len of data buffer
 *
 * Completes pdu processing by freeing any resources allocated at
 * queuecommand or send generic. session lock must be held and verify
 * itt must have been called.
 */
int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
			 char *data, int datalen)
{
	struct iscsi_session *session = conn->session;
	int opcode = hdr->opcode & ISCSI_OPCODE_MASK, rc = 0;
	struct iscsi_cmd_task *ctask;
	struct iscsi_mgmt_task *mtask;
	uint32_t itt;

	if (hdr->itt != cpu_to_be32(ISCSI_RESERVED_TAG))
		itt = hdr->itt & ISCSI_ITT_MASK;
	else
		itt = hdr->itt;

	if (itt < session->cmds_max) {
		ctask = session->cmds[itt];

		debug_scsi("cmdrsp [op 0x%x cid %d itt 0x%x len %d]\n",
			   opcode, conn->id, ctask->itt, datalen);

		switch(opcode) {
		case ISCSI_OP_SCSI_CMD_RSP:
			BUG_ON((void*)ctask != ctask->sc->SCp.ptr);
			rc = iscsi_scsi_cmd_rsp(conn, hdr, ctask, data,
						datalen);
			break;
		case ISCSI_OP_SCSI_DATA_IN:
			BUG_ON((void*)ctask != ctask->sc->SCp.ptr);
			if (hdr->flags & ISCSI_FLAG_DATA_STATUS) {
				conn->scsirsp_pdus_cnt++;
				iscsi_complete_command(session, ctask);
			}
			break;
		case ISCSI_OP_R2T:
			/* LLD handles this for now */
			break;
		default:
			rc = ISCSI_ERR_BAD_OPCODE;
			break;
		}
	} else if (itt >= ISCSI_MGMT_ITT_OFFSET &&
		   itt < ISCSI_MGMT_ITT_OFFSET + session->mgmtpool_max) {
		mtask = session->mgmt_cmds[itt - ISCSI_MGMT_ITT_OFFSET];

		debug_scsi("immrsp [op 0x%x cid %d itt 0x%x len %d]\n",
			   opcode, conn->id, mtask->itt, datalen);

		rc = iscsi_check_assign_cmdsn(session,
					      (struct iscsi_nopin*)hdr);
		if (rc)
			goto done;

		switch(opcode) {
		case ISCSI_OP_LOGOUT_RSP:
			conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
			/* fall through */
		case ISCSI_OP_LOGIN_RSP:
		case ISCSI_OP_TEXT_RSP:
			/*
			 * login related PDU's exp_statsn is handled in
			 * userspace
			 */
			rc = iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen);
			list_del(&mtask->running);
			if (conn->login_mtask != mtask)
				__kfifo_put(session->mgmtpool.queue,
					    (void*)&mtask, sizeof(void*));
			break;
		case ISCSI_OP_SCSI_TMFUNC_RSP:
			if (datalen) {
				rc = ISCSI_ERR_PROTO;
				break;
			}

			conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
			conn->tmfrsp_pdus_cnt++;
			if (conn->tmabort_state == TMABORT_INITIAL) {
				conn->tmabort_state =
					((struct iscsi_tm_rsp *)hdr)->
					response == ISCSI_TMF_RSP_COMPLETE ?
						TMABORT_SUCCESS:TMABORT_FAILED;
				/* unblock eh_abort() */
				wake_up(&conn->ehwait);
			}
			break;
		case ISCSI_OP_NOOP_IN:
			if (hdr->ttt != ISCSI_RESERVED_TAG) {
				rc = ISCSI_ERR_PROTO;
				break;
			}
			conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;

			rc = iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen);
			list_del(&mtask->running);
			if (conn->login_mtask != mtask)
				__kfifo_put(session->mgmtpool.queue,
					    (void*)&mtask, sizeof(void*));
			break;
		default:
			rc = ISCSI_ERR_BAD_OPCODE;
			break;
		}
	} else if (itt == ISCSI_RESERVED_TAG) {
		switch(opcode) {
		case ISCSI_OP_NOOP_IN:
			if (!datalen) {
				rc = iscsi_check_assign_cmdsn(session,
						 (struct iscsi_nopin*)hdr);
				if (!rc && hdr->ttt != ISCSI_RESERVED_TAG)
					rc = iscsi_recv_pdu(conn->cls_conn,
							    hdr, NULL, 0);
			} else
				rc = ISCSI_ERR_PROTO;
			break;
		case ISCSI_OP_REJECT:
			/* we need sth like iscsi_reject_rsp()*/
		case ISCSI_OP_ASYNC_EVENT:
			conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
			/* we need sth like iscsi_async_event_rsp() */
			rc = ISCSI_ERR_BAD_OPCODE;
			break;
		default:
			rc = ISCSI_ERR_BAD_OPCODE;
			break;
		}
	} else
		rc = ISCSI_ERR_BAD_ITT;

done:
	return rc;
}
EXPORT_SYMBOL_GPL(__iscsi_complete_pdu);

int iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
		       char *data, int datalen)
{
	int rc;

	spin_lock(&conn->session->lock);
	rc = __iscsi_complete_pdu(conn, hdr, data, datalen);
	spin_unlock(&conn->session->lock);
	return rc;
}
EXPORT_SYMBOL_GPL(iscsi_complete_pdu);

/* verify itt (itt encoding: age+cid+itt) */
int iscsi_verify_itt(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
		     uint32_t *ret_itt)
{
	struct iscsi_session *session = conn->session;
	struct iscsi_cmd_task *ctask;
	uint32_t itt;

	if (hdr->itt != cpu_to_be32(ISCSI_RESERVED_TAG)) {
		if ((hdr->itt & ISCSI_AGE_MASK) !=
		    (session->age << ISCSI_AGE_SHIFT)) {
			printk(KERN_ERR "iscsi: received itt %x expected "
				"session age (%x)\n", hdr->itt,
				session->age & ISCSI_AGE_MASK);
			return ISCSI_ERR_BAD_ITT;
		}

		if ((hdr->itt & ISCSI_CID_MASK) !=
		    (conn->id << ISCSI_CID_SHIFT)) {
			printk(KERN_ERR "iscsi: received itt %x, expected "
				"CID (%x)\n", hdr->itt, conn->id);
			return ISCSI_ERR_BAD_ITT;
		}
		itt = hdr->itt & ISCSI_ITT_MASK;
	} else
		itt = hdr->itt;

	if (itt < session->cmds_max) {
		ctask = session->cmds[itt];

		if (!ctask->sc) {
			printk(KERN_INFO "iscsi: dropping ctask with "
			       "itt 0x%x\n", ctask->itt);
			/* force drop */
			return ISCSI_ERR_NO_SCSI_CMD;
		}

		if (ctask->sc->SCp.phase != session->age) {
			printk(KERN_ERR "iscsi: ctask's session age %d, "
				"expected %d\n", ctask->sc->SCp.phase,
				session->age);
			return ISCSI_ERR_SESSION_FAILED;
		}
	}

	*ret_itt = itt;
	return 0;
}
EXPORT_SYMBOL_GPL(iscsi_verify_itt);

void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err)
{
	struct iscsi_session *session = conn->session;
	unsigned long flags;

	spin_lock_irqsave(&session->lock, flags);
	if (session->state == ISCSI_STATE_FAILED) {
		spin_unlock_irqrestore(&session->lock, flags);
		return;
	}

	if (conn->stop_stage == 0)
		session->state = ISCSI_STATE_FAILED;
	spin_unlock_irqrestore(&session->lock, flags);
	set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
	set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
	iscsi_conn_error(conn->cls_conn, err);
}
EXPORT_SYMBOL_GPL(iscsi_conn_failure);

/**
 * iscsi_data_xmit - xmit any command into the scheduled connection
 * @conn: iscsi connection
 *
 * Notes:
 *	The function can return -EAGAIN in which case the caller must
 *	re-schedule it again later or recover. '0' return code means
 *	successful xmit.
 **/
static int iscsi_data_xmit(struct iscsi_conn *conn)
{
	struct iscsi_transport *tt;
	int rc = 0;

	if (unlikely(conn->suspend_tx)) {
		debug_scsi("conn %d Tx suspended!\n", conn->id);
		return -ENODATA;
	}
	tt = conn->session->tt;

	/*
	 * Transmit in the following order:
	 *
	 * 1) un-finished xmit (ctask or mtask)
	 * 2) immediate control PDUs
	 * 3) write data
	 * 4) SCSI commands
	 * 5) non-immediate control PDUs
	 *
	 * No need to lock around __kfifo_get as long as
	 * there's one producer and one consumer.
	 */

	BUG_ON(conn->ctask && conn->mtask);

	if (conn->ctask) {
		rc = tt->xmit_cmd_task(conn, conn->ctask);
		if (rc)
			goto again;
		/* done with this in-progress ctask */
		conn->ctask = NULL;
	}
	if (conn->mtask) {
		rc = tt->xmit_mgmt_task(conn, conn->mtask);
	        if (rc)
		        goto again;
		/* done with this in-progress mtask */
		conn->mtask = NULL;
	}

	/* process immediate first */
        if (unlikely(__kfifo_len(conn->immqueue))) {
	        while (__kfifo_get(conn->immqueue, (void*)&conn->mtask,
			           sizeof(void*))) {
			spin_lock_bh(&conn->session->lock);
			list_add_tail(&conn->mtask->running,
				      &conn->mgmt_run_list);
			spin_unlock_bh(&conn->session->lock);
			rc = tt->xmit_mgmt_task(conn, conn->mtask);
		        if (rc)
			        goto again;
	        }
		/* done with this mtask */
		conn->mtask = NULL;
	}

	/* process command queue */
	while (__kfifo_get(conn->xmitqueue, (void*)&conn->ctask,
			   sizeof(void*))) {
		/*
		 * iscsi tcp may readd the task to the xmitqueue to send
		 * write data
		 */
		spin_lock_bh(&conn->session->lock);
		if (list_empty(&conn->ctask->running))
			list_add_tail(&conn->ctask->running, &conn->run_list);
		spin_unlock_bh(&conn->session->lock);
		rc = tt->xmit_cmd_task(conn, conn->ctask);
		if (rc)
			goto again;
	}
	/* done with this ctask */
	conn->ctask = NULL;

	/* process the rest control plane PDUs, if any */
        if (unlikely(__kfifo_len(conn->mgmtqueue))) {
	        while (__kfifo_get(conn->mgmtqueue, (void*)&conn->mtask,
			           sizeof(void*))) {
			spin_lock_bh(&conn->session->lock);
			list_add_tail(&conn->mtask->running,
				      &conn->mgmt_run_list);
			spin_unlock_bh(&conn->session->lock);
		        rc = tt->xmit_mgmt_task(conn, conn->mtask);
			if (rc)
			        goto again;
	        }
		/* done with this mtask */
		conn->mtask = NULL;
	}

	return -ENODATA;

again:
	if (unlikely(conn->suspend_tx))
		return -ENODATA;

	return rc;
}

static void iscsi_xmitworker(void *data)
{
	struct iscsi_conn *conn = data;
	int rc;
	/*
	 * serialize Xmit worker on a per-connection basis.
	 */
	mutex_lock(&conn->xmitmutex);
	do {
		rc = iscsi_data_xmit(conn);
	} while (rc >= 0 || rc == -EAGAIN);
	mutex_unlock(&conn->xmitmutex);
}

enum {
	FAILURE_BAD_HOST = 1,
	FAILURE_SESSION_FAILED,
	FAILURE_SESSION_FREED,
	FAILURE_WINDOW_CLOSED,
	FAILURE_SESSION_TERMINATE,
	FAILURE_SESSION_IN_RECOVERY,
	FAILURE_SESSION_RECOVERY_TIMEOUT,
};

int iscsi_queuecommand(struct scsi_cmnd *sc, void (*done)(struct scsi_cmnd *))
{
	struct Scsi_Host *host;
	int reason = 0;
	struct iscsi_session *session;
	struct iscsi_conn *conn;
	struct iscsi_cmd_task *ctask = NULL;

	sc->scsi_done = done;
	sc->result = 0;

	host = sc->device->host;
	session = iscsi_hostdata(host->hostdata);

	spin_lock(&session->lock);

	/*
	 * ISCSI_STATE_FAILED is a temp. state. The recovery
	 * code will decide what is best to do with command queued
	 * during this time
	 */
	if (session->state != ISCSI_STATE_LOGGED_IN &&
	    session->state != ISCSI_STATE_FAILED) {
		/*
		 * to handle the race between when we set the recovery state
		 * and block the session we requeue here (commands could
		 * be entering our queuecommand while a block is starting
		 * up because the block code is not locked)
		 */
		if (session->state == ISCSI_STATE_IN_RECOVERY) {
			reason = FAILURE_SESSION_IN_RECOVERY;
			goto reject;
		}

		if (session->state == ISCSI_STATE_RECOVERY_FAILED)
			reason = FAILURE_SESSION_RECOVERY_TIMEOUT;
		else if (session->state == ISCSI_STATE_TERMINATE)
			reason = FAILURE_SESSION_TERMINATE;
		else
			reason = FAILURE_SESSION_FREED;
		goto fault;
	}

	/*
	 * Check for iSCSI window and take care of CmdSN wrap-around
	 */
	if ((int)(session->max_cmdsn - session->cmdsn) < 0) {
		reason = FAILURE_WINDOW_CLOSED;
		goto reject;
	}

	conn = session->leadconn;

	__kfifo_get(session->cmdpool.queue, (void*)&ctask, sizeof(void*));
	sc->SCp.phase = session->age;
	sc->SCp.ptr = (char *)ctask;

	ctask->mtask = NULL;
	ctask->conn = conn;
	ctask->sc = sc;
	INIT_LIST_HEAD(&ctask->running);
	ctask->total_length = sc->request_bufflen;
	iscsi_prep_scsi_cmd_pdu(ctask);

	session->tt->init_cmd_task(ctask);

	__kfifo_put(conn->xmitqueue, (void*)&ctask, sizeof(void*));
	debug_scsi(
	       "ctask enq [%s cid %d sc %lx itt 0x%x len %d cmdsn %d win %d]\n",
		sc->sc_data_direction == DMA_TO_DEVICE ? "write" : "read",
		conn->id, (long)sc, ctask->itt, sc->request_bufflen,
		session->cmdsn, session->max_cmdsn - session->exp_cmdsn + 1);
	spin_unlock(&session->lock);

	scsi_queue_work(host, &conn->xmitwork);
	return 0;

reject:
	spin_unlock(&session->lock);
	debug_scsi("cmd 0x%x rejected (%d)\n", sc->cmnd[0], reason);
	return SCSI_MLQUEUE_HOST_BUSY;

fault:
	spin_unlock(&session->lock);
	printk(KERN_ERR "iscsi: cmd 0x%x is not queued (%d)\n",
	       sc->cmnd[0], reason);
	sc->result = (DID_NO_CONNECT << 16);
	sc->resid = sc->request_bufflen;
	sc->scsi_done(sc);
	return 0;
}
EXPORT_SYMBOL_GPL(iscsi_queuecommand);

int iscsi_change_queue_depth(struct scsi_device *sdev, int depth)
{
	if (depth > ISCSI_MAX_CMD_PER_LUN)
		depth = ISCSI_MAX_CMD_PER_LUN;
	scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
	return sdev->queue_depth;
}
EXPORT_SYMBOL_GPL(iscsi_change_queue_depth);

static int
iscsi_conn_send_generic(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
			char *data, uint32_t data_size)
{
	struct iscsi_session *session = conn->session;
	struct iscsi_nopout *nop = (struct iscsi_nopout *)hdr;
	struct iscsi_mgmt_task *mtask;

	spin_lock_bh(&session->lock);
	if (session->state == ISCSI_STATE_TERMINATE) {
		spin_unlock_bh(&session->lock);
		return -EPERM;
	}
	if (hdr->opcode == (ISCSI_OP_LOGIN | ISCSI_OP_IMMEDIATE) ||
	    hdr->opcode == (ISCSI_OP_TEXT | ISCSI_OP_IMMEDIATE))
		/*
		 * Login and Text are sent serially, in
		 * request-followed-by-response sequence.
		 * Same mtask can be used. Same ITT must be used.
		 * Note that login_mtask is preallocated at conn_create().
		 */
		mtask = conn->login_mtask;
	else {
		BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
		BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);

		nop->exp_statsn = cpu_to_be32(conn->exp_statsn);
		if (!__kfifo_get(session->mgmtpool.queue,
				 (void*)&mtask, sizeof(void*))) {
			spin_unlock_bh(&session->lock);
			return -ENOSPC;
		}
	}

	/*
	 * pre-format CmdSN for outgoing PDU.
	 */
	if (hdr->itt != cpu_to_be32(ISCSI_RESERVED_TAG)) {
		hdr->itt = mtask->itt | (conn->id << ISCSI_CID_SHIFT) |
			   (session->age << ISCSI_AGE_SHIFT);
		nop->cmdsn = cpu_to_be32(session->cmdsn);
		if (conn->c_stage == ISCSI_CONN_STARTED &&
		    !(hdr->opcode & ISCSI_OP_IMMEDIATE))
			session->cmdsn++;
	} else
		/* do not advance CmdSN */
		nop->cmdsn = cpu_to_be32(session->cmdsn);

	if (data_size) {
		memcpy(mtask->data, data, data_size);
		mtask->data_count = data_size;
	} else
		mtask->data_count = 0;

	INIT_LIST_HEAD(&mtask->running);
	memcpy(mtask->hdr, hdr, sizeof(struct iscsi_hdr));
	if (session->tt->init_mgmt_task)
		session->tt->init_mgmt_task(conn, mtask, data, data_size);
	spin_unlock_bh(&session->lock);

	debug_scsi("mgmtpdu [op 0x%x hdr->itt 0x%x datalen %d]\n",
		   hdr->opcode, hdr->itt, data_size);

	/*
	 * since send_pdu() could be called at least from two contexts,
	 * we need to serialize __kfifo_put, so we don't have to take
	 * additional lock on fast data-path
	 */
        if (hdr->opcode & ISCSI_OP_IMMEDIATE)
	        __kfifo_put(conn->immqueue, (void*)&mtask, sizeof(void*));
	else
	        __kfifo_put(conn->mgmtqueue, (void*)&mtask, sizeof(void*));

	scsi_queue_work(session->host, &conn->xmitwork);
	return 0;
}

int iscsi_conn_send_pdu(struct iscsi_cls_conn *cls_conn, struct iscsi_hdr *hdr,
			char *data, uint32_t data_size)
{
	struct iscsi_conn *conn = cls_conn->dd_data;
	int rc;

	mutex_lock(&conn->xmitmutex);
	rc = iscsi_conn_send_generic(conn, hdr, data, data_size);
	mutex_unlock(&conn->xmitmutex);

	return rc;
}
EXPORT_SYMBOL_GPL(iscsi_conn_send_pdu);

void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
{
	struct iscsi_session *session = class_to_transport_session(cls_session);
	struct iscsi_conn *conn = session->leadconn;

	spin_lock_bh(&session->lock);
	if (session->state != ISCSI_STATE_LOGGED_IN) {
		session->state = ISCSI_STATE_RECOVERY_FAILED;
		if (conn)
			wake_up(&conn->ehwait);
	}
	spin_unlock_bh(&session->lock);
}
EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);

int iscsi_eh_host_reset(struct scsi_cmnd *sc)
{
	struct Scsi_Host *host = sc->device->host;
	struct iscsi_session *session = iscsi_hostdata(host->hostdata);
	struct iscsi_conn *conn = session->leadconn;
	int fail_session = 0;

	spin_lock_bh(&session->lock);
	if (session->state == ISCSI_STATE_TERMINATE) {
failed:
		debug_scsi("failing host reset: session terminated "
			   "[CID %d age %d]", conn->id, session->age);
		spin_unlock_bh(&session->lock);
		return FAILED;
	}

	if (sc->SCp.phase == session->age) {
		debug_scsi("failing connection CID %d due to SCSI host reset",
			   conn->id);
		fail_session = 1;
	}
	spin_unlock_bh(&session->lock);

	/*
	 * we drop the lock here but the leadconn cannot be destoyed while
	 * we are in the scsi eh
	 */
	if (fail_session)
		iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);

	debug_scsi("iscsi_eh_host_reset wait for relogin\n");
	wait_event_interruptible(conn->ehwait,
				 session->state == ISCSI_STATE_TERMINATE ||
				 session->state == ISCSI_STATE_LOGGED_IN ||
				 session->state == ISCSI_STATE_RECOVERY_FAILED);
	if (signal_pending(current))
		flush_signals(current);

	spin_lock_bh(&session->lock);
	if (session->state == ISCSI_STATE_LOGGED_IN)
		printk(KERN_INFO "iscsi: host reset succeeded\n");
	else
		goto failed;
	spin_unlock_bh(&session->lock);

	return SUCCESS;
}
EXPORT_SYMBOL_GPL(iscsi_eh_host_reset);

static void iscsi_tmabort_timedout(unsigned long data)
{
	struct iscsi_cmd_task *ctask = (struct iscsi_cmd_task *)data;
	struct iscsi_conn *conn = ctask->conn;
	struct iscsi_session *session = conn->session;

	spin_lock(&session->lock);
	if (conn->tmabort_state == TMABORT_INITIAL) {
		conn->tmabort_state = TMABORT_TIMEDOUT;
		debug_scsi("tmabort timedout [sc %p itt 0x%x]\n",
			ctask->sc, ctask->itt);
		/* unblock eh_abort() */
		wake_up(&conn->ehwait);
	}
	spin_unlock(&session->lock);
}

/* must be called with the mutex lock */
static int iscsi_exec_abort_task(struct scsi_cmnd *sc,
				 struct iscsi_cmd_task *ctask)
{
	struct iscsi_conn *conn = ctask->conn;
	struct iscsi_session *session = conn->session;
Mode	Name	Size
-rw-r--r--	.gitignore	35	log stats plain blame
-rw-r--r--	Kconfig	910	log stats plain blame
-rw-r--r--	Makefile	1104	log stats plain blame
-rw-r--r--	access.c	4568	log stats plain blame
-rw-r--r--	bus.c	5329	log stats plain blame
-rw-r--r--	hotplug.c	1296	log stats plain blame
d---------	hotplug	2032	log stats plain
-rw-r--r--	msi.c	36676	log stats plain blame
-rw-r--r--	msi.h	4975	log stats plain blame
-rw-r--r--	pci-acpi.c	8368	log stats plain blame
-rw-r--r--	pci-driver.c	13506	log stats plain blame
-rw-r--r--	pci-sysfs.c	14330	log stats plain blame
-rw-r--r--	pci.c	25055	log stats plain blame
-rw-r--r--	pci.h	3898	log stats plain blame
d---------	pcie	232	log stats plain
-rw-r--r--	probe.c	28868	log stats plain blame
-rw-r--r--	proc.c	10205	log stats plain blame
-rw-r--r--	quirks.c	51495	log stats plain blame
-rw-r--r--	remove.c	3072	log stats plain blame
-rw-r--r--	rom.c	6621	log stats plain blame
-rw-r--r--	search.c	13294	log stats plain blame
-rw-r--r--	setup-bus.c	15340	log stats plain blame
-rw-r--r--	setup-irq.c	1682	log stats plain blame
-rw-r--r--	setup-res.c	5469	log stats plain blame
-rw-r--r--	syscall.c	2799	log stats plain blame