5 files changed, 561 insertions, 274 deletions

diff --git a/drivers/scsi/iscsi_tcp.c b/drivers/scsi/iscsi_tcp.c
index 6e510f3cfbf..aca3e23b1b9 100644
--- a/drivers/scsi/iscsi_tcp.c
+++ b/drivers/scsi/iscsi_tcp.c
@@ -82,6 +82,9 @@ module_param_named(max_lun, iscsi_max_lun, uint, S_IRUGO);
 /* global data */
 static kmem_cache_t *taskcache;
 
+#define session_to_cls(_sess) \
+	hostdata_session(_sess->host->hostdata)
+
 static inline void
 iscsi_buf_init_virt(struct iscsi_buf *ibuf, char *vbuf, int size)
 {
@@ -230,17 +233,19 @@ iscsi_hdr_extract(struct iscsi_conn *conn)
 	return 0;
 }
 
-static inline void
-iscsi_ctask_cleanup(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
+/*
+ * must be called with session lock
+ */
+static void
+__iscsi_ctask_cleanup(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
 {
-	struct scsi_cmnd *sc = ctask->sc;
 	struct iscsi_session *session = conn->session;
+	struct scsi_cmnd *sc;
 
-	spin_lock(&session->lock);
-	if (unlikely(!sc)) {
-		spin_unlock(&session->lock);
+	sc = ctask->sc;
+	if (unlikely(!sc))
 		return;
-	}
+
 	if (sc->sc_data_direction == DMA_TO_DEVICE) {
 		struct iscsi_data_task *dtask, *n;
 		/* WRITE: cleanup Data-Out's if any */
@@ -252,7 +257,20 @@ iscsi_ctask_cleanup(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
 	ctask->xmstate = XMSTATE_IDLE;
 	ctask->r2t = NULL;
 	ctask->sc = NULL;
+	list_del(&ctask->running);
+
 	__kfifo_put(session->cmdpool.queue, (void*)&ctask, sizeof(void*));
+
+	sc->scsi_done(sc);
+}
+
+static void
+iscsi_ctask_cleanup(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
+{
+	struct iscsi_session *session = conn->session;
+
+	spin_lock(&session->lock);
+	__iscsi_ctask_cleanup(conn, ctask);
 	spin_unlock(&session->lock);
 }
 
@@ -311,7 +329,6 @@ out:
 		   (long)sc, sc->result, ctask->itt);
 	conn->scsirsp_pdus_cnt++;
 	iscsi_ctask_cleanup(conn, ctask);
-	sc->scsi_done(sc);
 	return rc;
 }
 
@@ -395,6 +412,7 @@ iscsi_solicit_data_init(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
 
 	dtask = mempool_alloc(ctask->datapool, GFP_ATOMIC);
 	BUG_ON(!dtask);
+	INIT_LIST_HEAD(&dtask->item);
 	hdr = &dtask->hdr;
 	memset(hdr, 0, sizeof(struct iscsi_data));
 	hdr->ttt = r2t->ttt;
@@ -710,8 +728,6 @@ iscsi_hdr_recv(struct iscsi_conn *conn)
 			conn->tmfrsp_pdus_cnt++;
 			spin_lock(&session->lock);
 			if (conn->tmabort_state == TMABORT_INITIAL) {
-				__kfifo_put(session->mgmtpool.queue,
-						(void*)&mtask, sizeof(void*));
 				conn->tmabort_state =
 					((struct iscsi_tm_rsp *)hdr)->
 					response == ISCSI_TMF_RSP_COMPLETE ?
@@ -986,7 +1002,6 @@ done:
 			   (long)sc, sc->result, ctask->itt);
 		conn->scsirsp_pdus_cnt++;
 		iscsi_ctask_cleanup(conn, ctask);
-		sc->scsi_done(sc);
 	}
 
 	return rc;
@@ -1460,6 +1475,7 @@ iscsi_solicit_data_cont(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
 
 	dtask = mempool_alloc(ctask->datapool, GFP_ATOMIC);
 	BUG_ON(!dtask);
+	INIT_LIST_HEAD(&dtask->item);
 	hdr = &dtask->hdr;
 	memset(hdr, 0, sizeof(struct iscsi_data));
 	hdr->ttt = r2t->ttt;
@@ -1506,6 +1522,7 @@ iscsi_unsolicit_data_init(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
 
 	dtask = mempool_alloc(ctask->datapool, GFP_ATOMIC);
 	BUG_ON(!dtask);
+	INIT_LIST_HEAD(&dtask->item);
 	hdr = &dtask->hdr;
 	memset(hdr, 0, sizeof(struct iscsi_data));
 	hdr->ttt = cpu_to_be32(ISCSI_RESERVED_TAG);
@@ -1550,6 +1567,7 @@ iscsi_cmd_init(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
 
 	BUG_ON(__kfifo_len(ctask->r2tqueue));
 
+	INIT_LIST_HEAD(&ctask->running);
 	ctask->sc = sc;
 	ctask->conn = conn;
 	ctask->hdr.opcode = ISCSI_OP_SCSI_CMD;
@@ -1680,7 +1698,7 @@ iscsi_mtask_xmit(struct iscsi_conn *conn, struct iscsi_mgmt_task *mtask)
 		if (mtask->data_count)
 			mtask->xmstate |= XMSTATE_IMM_DATA;
 		if (conn->c_stage != ISCSI_CONN_INITIAL_STAGE &&
-	    	    conn->stop_stage != STOP_CONN_RECOVER &&
+		    conn->stop_stage != STOP_CONN_RECOVER &&
 		    conn->hdrdgst_en)
 			iscsi_hdr_digest(conn, &mtask->headbuf,
 					(u8*)mtask->hdrext);
@@ -2226,6 +2244,7 @@ iscsi_data_xmit(struct iscsi_conn *conn)
 	/* process command queue */
 	while (__kfifo_get(conn->xmitqueue, (void*)&conn->ctask,
 			   sizeof(void*))) {
+		list_add_tail(&conn->ctask->running, &conn->run_list);
 		if (iscsi_ctask_xmit(conn, conn->ctask))
 			goto again;
 	}
@@ -2277,11 +2296,14 @@ iscsi_xmitworker(void *data)
 	mutex_unlock(&conn->xmitmutex);
 }
 
-#define FAILURE_BAD_HOST		1
-#define FAILURE_SESSION_FAILED		2
-#define FAILURE_SESSION_FREED		3
-#define FAILURE_WINDOW_CLOSED		4
-#define FAILURE_SESSION_TERMINATE	5
+enum {
+	FAILURE_BAD_HOST = 1,
+	FAILURE_SESSION_FAILED,
+	FAILURE_SESSION_FREED,
+	FAILURE_WINDOW_CLOSED,
+	FAILURE_SESSION_TERMINATE,
+	FAILURE_SESSION_RECOVERY_TIMEOUT,
+};
 
 static int
 iscsi_queuecommand(struct scsi_cmnd *sc, void (*done)(struct scsi_cmnd *))
@@ -2297,12 +2319,14 @@ iscsi_queuecommand(struct scsi_cmnd *sc, void (*done)(struct scsi_cmnd *))
 
 	host = sc->device->host;
 	session = iscsi_hostdata(host->hostdata);
-	BUG_ON(host != session->host);
 
 	spin_lock(&session->lock);
 
 	if (session->state != ISCSI_STATE_LOGGED_IN) {
-		if (session->state == ISCSI_STATE_FAILED) {
+		if (session->recovery_failed) {
+			reason = FAILURE_SESSION_RECOVERY_TIMEOUT;
+			goto fault;
+		} else if (session->state == ISCSI_STATE_FAILED) {
 			reason = FAILURE_SESSION_FAILED;
 			goto reject;
 		} else if (session->state == ISCSI_STATE_TERMINATE) {
@@ -2350,11 +2374,6 @@ fault:
 	spin_unlock(&session->lock);
 	printk(KERN_ERR "iscsi_tcp: cmd 0x%x is not queued (%d)\n",
 	       sc->cmnd[0], reason);
-	sc->sense_buffer[0] = 0x70;
-	sc->sense_buffer[2] = NOT_READY;
-	sc->sense_buffer[7] = 0x6;
-	sc->sense_buffer[12] = 0x08;
-	sc->sense_buffer[13] = 0x00;
 	sc->result = (DID_NO_CONNECT << 16);
 	sc->resid = sc->request_bufflen;
 	sc->scsi_done(sc);
@@ -2445,6 +2464,7 @@ iscsi_conn_create(struct iscsi_cls_session *cls_session, uint32_t conn_idx)
 	conn->id = conn_idx;
 	conn->exp_statsn = 0;
 	conn->tmabort_state = TMABORT_INITIAL;
+	INIT_LIST_HEAD(&conn->run_list);
 
 	/* initial operational parameters */
 	conn->hdr_size = sizeof(struct iscsi_hdr);
@@ -2701,6 +2721,22 @@ iscsi_conn_bind(struct iscsi_cls_session *cls_session,
 	return 0;
 }
 
+static void
+iscsi_session_recovery_timedout(struct iscsi_cls_session *csession)
+{
+	struct Scsi_Host *shost = iscsi_session_to_shost(csession);
+	struct iscsi_session *session = iscsi_hostdata(shost->hostdata);
+	struct iscsi_conn *conn = session->leadconn;
+
+	spin_lock_bh(&session->lock);
+	if (session->state != ISCSI_STATE_LOGGED_IN) {
+		session->recovery_failed = 1;
+		if (conn)
+			wake_up(&conn->ehwait);
+	}
+	spin_unlock_bh(&session->lock);
+}
+
 static int
 iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
 {
@@ -2716,7 +2752,6 @@ iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
 	}
 
 	sk = conn->sock->sk;
-
 	write_lock_bh(&sk->sk_callback_lock);
 	spin_lock_bh(&session->lock);
 	conn->c_stage = ISCSI_CONN_STARTED;
@@ -2732,8 +2767,13 @@ iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
 		conn->stop_stage = 0;
 		conn->tmabort_state = TMABORT_INITIAL;
 		session->age++;
+		session->recovery_failed = 0;
+		spin_unlock_bh(&session->lock);
+		write_unlock_bh(&sk->sk_callback_lock);
+
+		iscsi_unblock_session(session_to_cls(session));
 		wake_up(&conn->ehwait);
-		break;
+		return 0;
 	case STOP_CONN_TERM:
 		session->conn_cnt++;
 		conn->stop_stage = 0;
@@ -2752,105 +2792,199 @@ iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
 	return 0;
 }
 
-static void
-iscsi_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
+static int
+iscsi_ctask_mtask_cleanup(struct iscsi_cmd_task *ctask)
 {
-	struct iscsi_conn *conn = cls_conn->dd_data;
+	struct iscsi_conn *conn = ctask->conn;
 	struct iscsi_session *session = conn->session;
+	struct iscsi_mgmt_task *mtask;
+
+	if (!ctask->mtask)
+		return -EINVAL;
+
+	while (__kfifo_get(conn->immqueue, (void*)&mtask, sizeof(void*))) {
+		if (mtask == ctask->mtask)
+			break;
+		__kfifo_put(conn->immqueue, (void*)&mtask, sizeof(void*));
+	}
+
+	__kfifo_put(session->mgmtpool.queue, (void*)&ctask->mtask,
+		    sizeof(void*));
+	ctask->mtask = NULL;
+	return 0;
+}
+
+static void
+fail_command(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask, int err)
+{
+	struct iscsi_r2t_info *r2t;
+	struct scsi_cmnd *sc;
+
+	/* flush ctask's r2t queues */
+	while (__kfifo_get(ctask->r2tqueue, (void*)&r2t, sizeof(void*)))
+		__kfifo_put(ctask->r2tpool.queue, (void*)&r2t, sizeof(void*));
+
+	iscsi_ctask_mtask_cleanup(ctask);
+
+	sc = ctask->sc;
+	if (!sc)
+		return;
+
+	sc->result = err;
+	sc->resid = sc->request_bufflen;
+
+	__iscsi_ctask_cleanup(conn, ctask);
+}
+
+/* Fail commands. Mutex and session lock held */
+static void
+fail_all_commands(struct iscsi_session *session, struct iscsi_conn *conn)
+{
+	struct iscsi_cmd_task *ctask, *tmp;
+
+	/* flush pending */
+	while (__kfifo_get(conn->xmitqueue, (void*)&ctask, sizeof(void*))) {
+		debug_scsi("failing pending sc %p itt 0x%x\n", ctask->sc,
+			   ctask->itt);
+		fail_command(conn, ctask, DID_BUS_BUSY << 16);
+	}
+
+	/* fail running */
+	list_for_each_entry_safe(ctask, tmp, &conn->run_list, running) {
+		debug_scsi("failing in progress sc %p itt 0x%x\n",
+			   ctask->sc, ctask->itt);
+		fail_command(conn, ctask, DID_BUS_BUSY << 16);
+	}
+
+	conn->ctask = NULL;
+}
+
+static void
+flush_control_queues(struct iscsi_session *session, struct iscsi_conn *conn)
+{
+	struct iscsi_mgmt_task *mtask;
+
+	/* TODO: handle running pdus */
+	while (__kfifo_get(conn->immqueue, (void*)&mtask, sizeof(void*)) ||
+	       __kfifo_get(conn->mgmtqueue, (void*)&mtask, sizeof(void*))) {
+		if (mtask == conn->login_mtask)
+			continue;
+		__kfifo_put(session->mgmtpool.queue, (void*)&mtask,
+			    sizeof(void*));
+	}
+
+	if (conn->mtask && conn->mtask != conn->login_mtask)
+		__kfifo_put(session->mgmtpool.queue, (void*)&conn->mtask,
+			    sizeof(void*));
+	conn->mtask = NULL;
+}
+
+static void
+iscsi_suspend_conn_rx(struct iscsi_conn *conn)
+{
 	struct sock *sk;
-	unsigned long flags;
 
 	BUG_ON(!conn->sock);
 	sk = conn->sock->sk;
 	write_lock_bh(&sk->sk_callback_lock);
 	set_bit(SUSPEND_BIT, &conn->suspend_rx);
 	write_unlock_bh(&sk->sk_callback_lock);
+}
 
-	mutex_lock(&conn->xmitmutex);
-
-	spin_lock_irqsave(session->host->host_lock, flags);
-	spin_lock(&session->lock);
+static void
+iscsi_start_session_recovery(struct iscsi_session *session,
+			     struct iscsi_conn *conn, int flag)
+{
+	spin_lock_bh(&session->lock);
+	if (conn->stop_stage == STOP_CONN_RECOVER ||
+	    conn->stop_stage == STOP_CONN_TERM) {
+		spin_unlock_bh(&session->lock);
+		return;
+	}
 	conn->stop_stage = flag;
+	spin_unlock_bh(&session->lock);
+
+	iscsi_suspend_conn_rx(conn);
+
+	mutex_lock(&conn->xmitmutex);
+	spin_lock_bh(&session->lock);
 	conn->c_stage = ISCSI_CONN_STOPPED;
 	set_bit(SUSPEND_BIT, &conn->suspend_tx);
 
-	if (flag != STOP_CONN_SUSPEND)
-		session->conn_cnt--;
-
+	session->conn_cnt--;
 	if (session->conn_cnt == 0 || session->leadconn == conn)
 		session->state = ISCSI_STATE_FAILED;
 
-	spin_unlock(&session->lock);
-	spin_unlock_irqrestore(session->host->host_lock, flags);
-
-	if (flag == STOP_CONN_TERM || flag == STOP_CONN_RECOVER) {
-		struct iscsi_cmd_task *ctask;
-		struct iscsi_mgmt_task *mtask;
+	spin_unlock_bh(&session->lock);
 
-		/*
-		 * Socket must go now.
-		 */
-		sock_hold(conn->sock->sk);
-		iscsi_conn_restore_callbacks(conn);
-		sock_put(conn->sock->sk);
+	/*
+	 * Socket must go now.
+	 */
+	sock_hold(conn->sock->sk);
+	iscsi_conn_restore_callbacks(conn);
+	sock_put(conn->sock->sk);
 
-		/*
-		 * flush xmit queues.
-		 */
-		spin_lock_bh(&session->lock);
-		while (__kfifo_get(conn->writequeue, (void*)&ctask,
-			    sizeof(void*)) ||
-			__kfifo_get(conn->xmitqueue, (void*)&ctask,
-			    sizeof(void*))) {
-			struct iscsi_r2t_info *r2t;
-
-			/*
-			 * flush ctask's r2t queues
-			 */
-			while (__kfifo_get(ctask->r2tqueue, (void*)&r2t,
-				sizeof(void*)))
-				__kfifo_put(ctask->r2tpool.queue, (void*)&r2t,
-					    sizeof(void*));
+	/*
+	 * flush queues.
+	 */
+	spin_lock_bh(&session->lock);
+	fail_all_commands(session, conn);
+	flush_control_queues(session, conn);
+	spin_unlock_bh(&session->lock);
 
-			spin_unlock_bh(&session->lock);
-			local_bh_disable();
-			iscsi_ctask_cleanup(conn, ctask);
-			local_bh_enable();
-			spin_lock_bh(&session->lock);
-		}
-		conn->ctask = NULL;
-		while (__kfifo_get(conn->immqueue, (void*)&mtask,
-			   sizeof(void*)) ||
-			__kfifo_get(conn->mgmtqueue, (void*)&mtask,
-			   sizeof(void*))) {
-			__kfifo_put(session->mgmtpool.queue,
-				    (void*)&mtask, sizeof(void*));
-		}
-		conn->mtask = NULL;
-		spin_unlock_bh(&session->lock);
+	/*
+	 * release socket only after we stopped data_xmit()
+	 * activity and flushed all outstandings
+	 */
+	sock_release(conn->sock);
+	conn->sock = NULL;
 
-		/*
-		 * release socket only after we stopped data_xmit()
-		 * activity and flushed all outstandings
-		 */
-		sock_release(conn->sock);
-		conn->sock = NULL;
+	/*
+	 * for connection level recovery we should not calculate
+	 * header digest. conn->hdr_size used for optimization
+	 * in hdr_extract() and will be re-negotiated at
+	 * set_param() time.
+	 */
+	if (flag == STOP_CONN_RECOVER) {
+		conn->hdr_size = sizeof(struct iscsi_hdr);
+		conn->hdrdgst_en = 0;
+		conn->datadgst_en = 0;
 
-		/*
-		 * for connection level recovery we should not calculate
-		 * header digest. conn->hdr_size used for optimization
-		 * in hdr_extract() and will be re-negotiated at
-		 * set_param() time.
-		 */
-		if (flag == STOP_CONN_RECOVER) {
-			conn->hdr_size = sizeof(struct iscsi_hdr);
-			conn->hdrdgst_en = 0;
-			conn->datadgst_en = 0;
-		}
+		if (session->state == ISCSI_STATE_FAILED)
+			iscsi_block_session(session_to_cls(session));
 	}
 	mutex_unlock(&conn->xmitmutex);
 }
 
+static void
+iscsi_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
+{
+	struct iscsi_conn *conn = cls_conn->dd_data;
+	struct iscsi_session *session = conn->session;
+
+	switch (flag) {
+	case STOP_CONN_RECOVER:
+	case STOP_CONN_TERM:
+		iscsi_start_session_recovery(session, conn, flag);
+		return;
+	case STOP_CONN_SUSPEND:
+		iscsi_suspend_conn_rx(conn);
+
+		mutex_lock(&conn->xmitmutex);
+		spin_lock_bh(&session->lock);
+
+		conn->stop_stage = flag;
+		conn->c_stage = ISCSI_CONN_STOPPED;
+		set_bit(SUSPEND_BIT, &conn->suspend_tx);
+
+		spin_unlock_bh(&session->lock);
+		mutex_unlock(&conn->xmitmutex);
+		break;
+	default:
+		printk(KERN_ERR "invalid stop flag %d\n", flag);
+	}
+}
+
 static int
 iscsi_conn_send_generic(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 			char *data, uint32_t data_size)
@@ -2940,23 +3074,54 @@ iscsi_conn_send_generic(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 static int
 iscsi_eh_host_reset(struct scsi_cmnd *sc)
 {
-	struct iscsi_cmd_task *ctask = (struct iscsi_cmd_task *)sc->SCp.ptr;
-	struct iscsi_conn *conn = ctask->conn;
-	struct iscsi_session *session = conn->session;
+	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);
 
-	debug_scsi("failing connection CID %d due to SCSI host reset "
-		   "[itt 0x%x age %d]", conn->id, ctask->itt,
-		   session->age);
-	iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
+	/*
+	 * 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);
+		/*
+		 * if userspace cannot respond then we must kick this off
+		 * here for it
+		 */
+		iscsi_start_session_recovery(session, conn, STOP_CONN_RECOVER);
+	}
+
+	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->recovery_failed);
+	if (signal_pending(current))
+		flush_signals(current);
+
+	spin_lock_bh(&session->lock);
+	if (session->state == ISCSI_STATE_LOGGED_IN)
+		printk(KERN_INFO "host reset succeeded\n");
+	else
+		goto failed;
+	spin_unlock_bh(&session->lock);
 
 	return SUCCESS;
 }
@@ -2970,8 +3135,6 @@ iscsi_tmabort_timedout(unsigned long data)
 
 	spin_lock(&session->lock);
 	if (conn->tmabort_state == TMABORT_INITIAL) {
-		__kfifo_put(session->mgmtpool.queue,
-				(void*)&ctask->mtask, sizeof(void*));
 		conn->tmabort_state = TMABORT_TIMEDOUT;
 		debug_scsi("tmabort timedout [sc %lx itt 0x%x]\n",
 			(long)ctask->sc, ctask->itt);
@@ -2981,186 +3144,163 @@ iscsi_tmabort_timedout(unsigned long data)
 	spin_unlock(&session->lock);
 }
 
+/* must be called with the mutex lock */
 static int
-iscsi_eh_abort(struct scsi_cmnd *sc)
+iscsi_exec_abort_task(struct scsi_cmnd *sc, struct iscsi_cmd_task *ctask)
 {
-	int rc;
-	struct iscsi_cmd_task *ctask = (struct iscsi_cmd_task *)sc->SCp.ptr;
 	struct iscsi_conn *conn = ctask->conn;
 	struct iscsi_session *session = conn->session;
-
-	conn->eh_abort_cnt++;
-	debug_scsi("aborting [sc %lx itt 0x%x]\n", (long)sc, ctask->itt);
+	struct iscsi_tm *hdr = &conn->tmhdr;
+	int rc;
 
 	/*
-	 * two cases for ERL=0 here:
-	 *
-	 * 1) connection-level failure;
-	 * 2) recovery due protocol error;
+	 * ctask timed out but session is OK requests must be serialized.
 	 */
-	mutex_lock(&conn->xmitmutex);
-	spin_lock_bh(&session->lock);
-	if (session->state != ISCSI_STATE_LOGGED_IN) {
-		if (session->state == ISCSI_STATE_TERMINATE) {
-			spin_unlock_bh(&session->lock);
-			mutex_unlock(&conn->xmitmutex);
-			goto failed;
-		}
-		spin_unlock_bh(&session->lock);
-	} else {
-		struct iscsi_tm *hdr = &conn->tmhdr;
+	memset(hdr, 0, sizeof(struct iscsi_tm));
+	hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
+	hdr->flags = ISCSI_TM_FUNC_ABORT_TASK;
+	hdr->flags |= ISCSI_FLAG_CMD_FINAL;
+	memcpy(hdr->lun, ctask->hdr.lun, sizeof(hdr->lun));
+	hdr->rtt = ctask->hdr.itt;
+	hdr->refcmdsn = ctask->hdr.cmdsn;
 
-		/*
-		 * Still LOGGED_IN...
-		 */
+	rc = iscsi_conn_send_generic(conn, (struct iscsi_hdr *)hdr,
+				     NULL, 0);
+	if (rc) {
+		iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
+		debug_scsi("abort sent failure [itt 0x%x] %d", ctask->itt, rc);
+		return rc;
+	}
 
-		if (!ctask->sc || sc->SCp.phase != session->age) {
-			/*
-			 * 1) ctask completed before time out. But session
-			 *    is still ok => Happy Retry.
-			 * 2) session was re-open during time out of ctask.
-			 */
-			spin_unlock_bh(&session->lock);
-			mutex_unlock(&conn->xmitmutex);
-			goto success;
-		}
-		conn->tmabort_state = TMABORT_INITIAL;
-		spin_unlock_bh(&session->lock);
+	debug_scsi("abort sent [itt 0x%x]\n", ctask->itt);
 
-		/*
-		 * ctask timed out but session is OK
-		 * ERL=0 requires task mgmt abort to be issued on each
-		 * failed command. requests must be serialized.
-		 */
-		memset(hdr, 0, sizeof(struct iscsi_tm));
-		hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
-		hdr->flags = ISCSI_TM_FUNC_ABORT_TASK;
-		hdr->flags |= ISCSI_FLAG_CMD_FINAL;
-		memcpy(hdr->lun, ctask->hdr.lun, sizeof(hdr->lun));
-		hdr->rtt = ctask->hdr.itt;
-		hdr->refcmdsn = ctask->hdr.cmdsn;
-
-		rc = iscsi_conn_send_generic(conn, (struct iscsi_hdr *)hdr,
-					     NULL, 0);
-		if (rc) {
-			iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
-			debug_scsi("abort sent failure [itt 0x%x]", ctask->itt);
-		} else {
-			struct iscsi_r2t_info *r2t;
-
-			/*
-			 * TMF abort vs. TMF response race logic
-			 */
-			spin_lock_bh(&session->lock);
-			ctask->mtask = (struct iscsi_mgmt_task *)
-				session->mgmt_cmds[(hdr->itt & ITT_MASK) -
-							ISCSI_MGMT_ITT_OFFSET];
-			/*
-			 * have to flush r2tqueue to avoid r2t leaks
-			 */
-			while (__kfifo_get(ctask->r2tqueue, (void*)&r2t,
-				sizeof(void*))) {
-				__kfifo_put(ctask->r2tpool.queue, (void*)&r2t,
-					sizeof(void*));
-			}
-			if (conn->tmabort_state == TMABORT_INITIAL) {
-				conn->tmfcmd_pdus_cnt++;
-				conn->tmabort_timer.expires = 3*HZ + jiffies;
-				conn->tmabort_timer.function =
-						iscsi_tmabort_timedout;
-				conn->tmabort_timer.data = (unsigned long)ctask;
-				add_timer(&conn->tmabort_timer);
-				debug_scsi("abort sent [itt 0x%x]", ctask->itt);
-			} else {
-				if (!ctask->sc ||
-				    conn->tmabort_state == TMABORT_SUCCESS) {
-					conn->tmabort_state = TMABORT_INITIAL;
-					spin_unlock_bh(&session->lock);
-					mutex_unlock(&conn->xmitmutex);
-					goto success;
-				}
-				conn->tmabort_state = TMABORT_INITIAL;
-				iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
-			}
-			spin_unlock_bh(&session->lock);
-		}
+	spin_lock_bh(&session->lock);
+	ctask->mtask = (struct iscsi_mgmt_task *)
+			session->mgmt_cmds[(hdr->itt & ITT_MASK) -
+					ISCSI_MGMT_ITT_OFFSET];
+
+	if (conn->tmabort_state == TMABORT_INITIAL) {
+		conn->tmfcmd_pdus_cnt++;
+		conn->tmabort_timer.expires = 10*HZ + jiffies;
+		conn->tmabort_timer.function = iscsi_tmabort_timedout;
+		conn->tmabort_timer.data = (unsigned long)ctask;
+		add_timer(&conn->tmabort_timer);
+		debug_scsi("abort set timeout [itt 0x%x]", ctask->itt);
 	}
+	spin_unlock_bh(&session->lock);
 	mutex_unlock(&conn->xmitmutex);
 
-
 	/*
 	 * block eh thread until:
 	 *
-	 * 1) abort response;
-	 * 2) abort timeout;
-	 * 3) session re-opened;
-	 * 4) session terminated;
+	 * 1) abort response
+	 * 2) abort timeout
+	 * 3) session is terminated or restarted or userspace has
+	 * given up on recovery
 	 */
-	for (;;) {
-		int p_state = session->state;
-
-		rc = wait_event_interruptible(conn->ehwait,
-			(p_state == ISCSI_STATE_LOGGED_IN ?
-			 (session->state == ISCSI_STATE_TERMINATE ||
-			  conn->tmabort_state != TMABORT_INITIAL) :
-			 (session->state == ISCSI_STATE_TERMINATE ||
-			  session->state == ISCSI_STATE_LOGGED_IN)));
-		if (rc) {
-			/* shutdown.. */
-			session->state = ISCSI_STATE_TERMINATE;
-			goto failed;
-		}
+	wait_event_interruptible(conn->ehwait,
+				 sc->SCp.phase != session->age ||
+				 session->state != ISCSI_STATE_LOGGED_IN ||
+				 conn->tmabort_state != TMABORT_INITIAL ||
+				 session->recovery_failed);
+	if (signal_pending(current))
+		flush_signals(current);
+	del_timer_sync(&conn->tmabort_timer);
 
-		if (signal_pending(current))
-			flush_signals(current);
+	mutex_lock(&conn->xmitmutex);
+	return 0;
+}
 
-		if (session->state == ISCSI_STATE_TERMINATE)
-			goto failed;
+static int
+iscsi_eh_abort(struct scsi_cmnd *sc)
+{
+	struct iscsi_cmd_task *ctask = (struct iscsi_cmd_task *)sc->SCp.ptr;
+	struct iscsi_cmd_task *tmp_ctask;
+	struct iscsi_conn *conn = ctask->conn;
+	struct iscsi_session *session = conn->session;
+	int rc;
 
-		spin_lock_bh(&session->lock);
-		if (sc->SCp.phase == session->age &&
-		   (conn->tmabort_state == TMABORT_TIMEDOUT ||
-		    conn->tmabort_state == TMABORT_FAILED)) {
-			conn->tmabort_state = TMABORT_INITIAL;
-			if (!ctask->sc) {
-				/*
-				 * ctask completed before tmf abort response or
-				 * time out.
-				 * But session is still ok => Happy Retry.
-				 */
-				spin_unlock_bh(&session->lock);
-				break;
-			}
-			spin_unlock_bh(&session->lock);
-			iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
-			continue;
+	conn->eh_abort_cnt++;
+	debug_scsi("aborting [sc %p itt 0x%x]\n", sc, ctask->itt);
+
+	mutex_lock(&conn->xmitmutex);
+	spin_lock_bh(&session->lock);
+
+	/*
+	 * If we are not logged in or we have started a new session
+	 * then let the host reset code handle this
+	 */
+	if (session->state != ISCSI_STATE_LOGGED_IN ||
+	    sc->SCp.phase != session->age)
+		goto failed;
+
+	/* ctask completed before time out */
+	if (!ctask->sc)
+		goto success;
+
+	/* what should we do here ? */
+	if (conn->ctask == ctask) {
+		printk(KERN_INFO "sc %p itt 0x%x partially sent. Failing "
+		       "abort\n", sc, ctask->itt);
+		goto failed;
+	}
+
+	/* check for the easy pending cmd abort */
+	while (__kfifo_get(conn->xmitqueue, (void*)&tmp_ctask, sizeof(void*))) {
+		if (tmp_ctask->itt == ctask->itt) {
+			debug_scsi("found pending task\n");
+			goto success;
 		}
+		__kfifo_put(conn->xmitqueue, (void*)&tmp_ctask, sizeof(void*));
+	}
+
+	conn->tmabort_state = TMABORT_INITIAL;
+
+	spin_unlock_bh(&session->lock);
+	rc = iscsi_exec_abort_task(sc, ctask);
+	spin_lock_bh(&session->lock);
+
+	iscsi_ctask_mtask_cleanup(ctask);
+	if (rc || sc->SCp.phase != session->age ||
+	    session->state != ISCSI_STATE_LOGGED_IN)
+		goto failed;
+
+	/* ctask completed before tmf abort response */
+	if (!ctask->sc) {
+		debug_scsi("sc completed while abort in progress\n");
+		goto success;
+	}
+
+	if (conn->tmabort_state != TMABORT_SUCCESS) {
 		spin_unlock_bh(&session->lock);
-		break;
+		iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
+		spin_lock_bh(&session->lock);
+		goto failed;
 	}
 
 success:
 	debug_scsi("abort success [sc %lx itt 0x%x]\n", (long)sc, ctask->itt);
-	rc = SUCCESS;
-	goto exit;
-
-failed:
-	debug_scsi("abort failed [sc %lx itt 0x%x]\n", (long)sc, ctask->itt);
-	rc = FAILED;
-
-exit:
-	del_timer_sync(&conn->tmabort_timer);
+	spin_unlock_bh(&session->lock);
 
-	mutex_lock(&conn->xmitmutex);
+	/* clean up task if aborted */
 	if (conn->sock) {
 		struct sock *sk = conn->sock->sk;
 
 		write_lock_bh(&sk->sk_callback_lock);
-		iscsi_ctask_cleanup(conn, ctask);
+		spin_lock(&session->lock);
+		fail_command(conn, ctask, DRIVER_TIMEOUT << 24);
+		spin_unlock(&session->lock);
 		write_unlock_bh(&sk->sk_callback_lock);
 	}
 	mutex_unlock(&conn->xmitmutex);
-	return rc;
+	return SUCCESS;
+
+failed:
+	spin_unlock_bh(&session->lock);
+	mutex_unlock(&conn->xmitmutex);
+
+	debug_scsi("abort failed [sc %lx itt 0x%x]\n", (long)sc, ctask->itt);
+	return FAILED;
 }
 
 static int
@@ -3359,16 +3499,6 @@ iscsi_conn_set_param(struct iscsi_cls_conn *cls_conn, enum iscsi_param param,
 	struct iscsi_conn *conn = cls_conn->dd_data;
 	struct iscsi_session *session = conn->session;
 
-	spin_lock_bh(&session->lock);
-	if (conn->c_stage != ISCSI_CONN_INITIAL_STAGE &&
-	    conn->stop_stage != STOP_CONN_RECOVER) {
-		printk(KERN_ERR "iscsi_tcp: can not change parameter [%d]\n",
-		       param);
-		spin_unlock_bh(&session->lock);
-		return 0;
-	}
-	spin_unlock_bh(&session->lock);
-
 	switch(param) {
 	case ISCSI_PARAM_MAX_RECV_DLENGTH: {
 		char *saveptr = conn->data;
@@ -3691,6 +3821,7 @@ static struct iscsi_transport iscsi_tcp_transport = {
 	.stop_conn		= iscsi_conn_stop,
 	.send_pdu		= iscsi_conn_send_pdu,
 	.get_stats		= iscsi_conn_get_stats,
+	.session_recovery_timedout = iscsi_session_recovery_timedout,
 };
 
 static int __init
diff --git a/drivers/scsi/iscsi_tcp.h b/drivers/scsi/iscsi_tcp.h
index ba26741ac15..12ef64179b4 100644
--- a/drivers/scsi/iscsi_tcp.h
+++ b/drivers/scsi/iscsi_tcp.h
@@ -159,6 +159,7 @@ struct iscsi_conn {
 	struct kfifo		*immqueue;	/* immediate xmit queue */
 	struct kfifo		*mgmtqueue;	/* mgmt (control) xmit queue */
 	struct kfifo		*xmitqueue;	/* data-path cmd queue */
+	struct list_head	run_list;	/* list of cmds in progress */
 	struct work_struct	xmitwork;	/* per-conn. xmit workqueue */
 	struct mutex		xmitmutex;	/* serializes connection xmit,
 						 * access to kfifos:	  *
@@ -228,6 +229,7 @@ struct iscsi_session {
 						 * - mgmtpool,		   *
 						 * - r2tpool		   */
 	int			state;		/* session state           */
+	int			recovery_failed;
 	struct list_head	item;
 	void			*auth_client;
 	int			conn_cnt;
@@ -310,6 +312,7 @@ struct iscsi_cmd_task {
 	struct iscsi_conn	*conn;			/* used connection    */
 	struct iscsi_mgmt_task	*mtask;			/* tmf mtask in progr */
 
+	struct list_head	running;		/* running cmd list */
 	struct iscsi_r2t_info	*r2t;			/* in progress R2T    */
 	struct iscsi_queue	r2tpool;
 	struct kfifo		*r2tqueue;
diff --git a/drivers/scsi/scsi_transport_iscsi.c b/drivers/scsi/scsi_transport_iscsi.c
index 72a71ebc9d0..e2b67e34d92 100644
--- a/drivers/scsi/scsi_transport_iscsi.c
+++ b/drivers/scsi/scsi_transport_iscsi.c
@@ -31,17 +31,17 @@
 #include <scsi/scsi_transport_iscsi.h>
 #include <scsi/iscsi_if.h>
 
-#define ISCSI_SESSION_ATTRS 10
+#define ISCSI_SESSION_ATTRS 11
 #define ISCSI_CONN_ATTRS 10
+#define ISCSI_HOST_ATTRS 0
 
 struct iscsi_internal {
 	struct scsi_transport_template t;
 	struct iscsi_transport *iscsi_transport;
 	struct list_head list;
 	struct class_device cdev;
-	/*
-	 * We do not have any private or other attrs.
-	 */
+
+	struct class_device_attribute *host_attrs[ISCSI_HOST_ATTRS + 1];
 	struct transport_container conn_cont;
 	struct class_device_attribute *conn_attrs[ISCSI_CONN_ATTRS + 1];
 	struct transport_container session_cont;
@@ -114,6 +114,24 @@ static struct attribute_group iscsi_transport_group = {
 	.attrs = iscsi_transport_attrs,
 };
 
+static int iscsi_setup_host(struct transport_container *tc, struct device *dev,
+			    struct class_device *cdev)
+{
+	struct Scsi_Host *shost = dev_to_shost(dev);
+	struct iscsi_host *ihost = shost->shost_data;
+
+	memset(ihost, 0, sizeof(*ihost));
+	INIT_LIST_HEAD(&ihost->sessions);
+	mutex_init(&ihost->mutex);
+	return 0;
+}
+
+static DECLARE_TRANSPORT_CLASS(iscsi_host_class,
+			       "iscsi_host",
+			       iscsi_setup_host,
+			       NULL,
+			       NULL);
+
 static DECLARE_TRANSPORT_CLASS(iscsi_session_class,
 			       "iscsi_session",
 			       NULL,
@@ -225,6 +243,54 @@ static int iscsi_is_session_dev(const struct device *dev)
 	return dev->release == iscsi_session_release;
 }
 
+static int iscsi_user_scan(struct Scsi_Host *shost, uint channel,
+			   uint id, uint lun)
+{
+	struct iscsi_host *ihost = shost->shost_data;
+	struct iscsi_cls_session *session;
+
+	mutex_lock(&ihost->mutex);
+	list_for_each_entry(session, &ihost->sessions, host_list) {
+		if ((channel == SCAN_WILD_CARD ||
+		     channel == session->channel) &&
+		    (id == SCAN_WILD_CARD || id == session->target_id))
+			scsi_scan_target(&session->dev, session->channel,
+					 session->target_id, lun, 1);
+	}
+	mutex_unlock(&ihost->mutex);
+
+	return 0;
+}
+
+static void session_recovery_timedout(void *data)
+{
+	struct iscsi_cls_session *session = data;
+
+	dev_printk(KERN_INFO, &session->dev, "session recovery timed out "
+		  "after %d secs\n", session->recovery_tmo);
+
+	if (session->transport->session_recovery_timedout)
+		session->transport->session_recovery_timedout(session);
+
+	scsi_target_unblock(&session->dev);
+}
+
+void iscsi_unblock_session(struct iscsi_cls_session *session)
+{
+	if (!cancel_delayed_work(&session->recovery_work))
+		flush_scheduled_work();
+	scsi_target_unblock(&session->dev);
+}
+EXPORT_SYMBOL_GPL(iscsi_unblock_session);
+
+void iscsi_block_session(struct iscsi_cls_session *session)
+{
+	scsi_target_block(&session->dev);
+	schedule_delayed_work(&session->recovery_work,
+			     session->recovery_tmo * HZ);
+}
+EXPORT_SYMBOL_GPL(iscsi_block_session);
+
 /**
  * iscsi_create_session - create iscsi class session
  * @shost: scsi host
@@ -233,8 +299,10 @@ static int iscsi_is_session_dev(const struct device *dev)
  * This can be called from a LLD or iscsi_transport.
  **/
 struct iscsi_cls_session *
-iscsi_create_session(struct Scsi_Host *shost, struct iscsi_transport *transport)
+iscsi_create_session(struct Scsi_Host *shost,
+		     struct iscsi_transport *transport, int channel)
 {
+	struct iscsi_host *ihost;
 	struct iscsi_cls_session *session;
 	int err;
 
@@ -246,13 +314,22 @@ iscsi_create_session(struct Scsi_Host *shost, struct iscsi_transport *transport)
 	if (!session)
 		goto module_put;
 	session->transport = transport;
+	session->recovery_tmo = 120;
+	INIT_WORK(&session->recovery_work, session_recovery_timedout, session);
+	INIT_LIST_HEAD(&session->host_list);
+	INIT_LIST_HEAD(&session->sess_list);
 
 	if (transport->sessiondata_size)
 		session->dd_data = &session[1];
 
 	/* this is released in the dev's release function */
 	scsi_host_get(shost);
+	ihost = shost->shost_data;
+
 	session->sid = iscsi_session_nr++;
+	session->channel = channel;
+	session->target_id = ihost->next_target_id++;
+
 	snprintf(session->dev.bus_id, BUS_ID_SIZE, "session%u",
 		 session->sid);
 	session->dev.parent = &shost->shost_gendev;
@@ -265,6 +342,10 @@ iscsi_create_session(struct Scsi_Host *shost, struct iscsi_transport *transport)
 	}
 	transport_register_device(&session->dev);
 
+	mutex_lock(&ihost->mutex);
+	list_add(&session->host_list, &ihost->sessions);
+	mutex_unlock(&ihost->mutex);
+
 	return session;
 
 free_session:
@@ -285,6 +366,16 @@ EXPORT_SYMBOL_GPL(iscsi_create_session);
  **/
 int iscsi_destroy_session(struct iscsi_cls_session *session)
 {
+	struct Scsi_Host *shost = iscsi_session_to_shost(session);
+	struct iscsi_host *ihost = shost->shost_data;
+
+	if (!cancel_delayed_work(&session->recovery_work))
+		flush_scheduled_work();
+
+	mutex_lock(&ihost->mutex);
+	list_del(&session->host_list);
+	mutex_unlock(&ihost->mutex);
+
 	transport_unregister_device(&session->dev);
 	device_unregister(&session->dev);
 	return 0;
@@ -435,7 +526,7 @@ iscsi_transport_create_session(struct scsi_transport_template *scsit,
 	if (scsi_add_host(shost, NULL))
 		goto free_host;
 
-	session = iscsi_create_session(shost, transport);
+	session = iscsi_create_session(shost, transport, 0);
 	if (!session)
 		goto remove_host;
 
@@ -466,12 +557,13 @@ int iscsi_transport_destroy_session(struct Scsi_Host *shost)
 	struct iscsi_cls_session *session;
 	unsigned long flags;
 
-	scsi_remove_host(shost);
 	session = hostdata_session(shost->hostdata);
 	spin_lock_irqsave(&sesslock, flags);
 	list_del(&session->sess_list);
 	spin_unlock_irqrestore(&sesslock, flags);
 	iscsi_destroy_session(session);
+
+	scsi_remove_host(shost);
 	/* ref from host alloc */
 	scsi_host_put(shost);
 	return 0;
@@ -594,6 +686,7 @@ iscsi_unicast_skb(struct mempool_zone *zone, struct sk_buff *skb)
 	}
 
 	spin_lock_irqsave(&zone->freelock, flags);
+	INIT_LIST_HEAD(skb_to_lh(skb));
 	list_add(skb_to_lh(skb), &zone->freequeue);
 	spin_unlock_irqrestore(&zone->freelock, flags);
 
@@ -888,6 +981,11 @@ iscsi_set_param(struct iscsi_transport *transport, struct iscsi_uevent *ev)
 		return -EINVAL;
 
 	switch (ev->u.set_param.param) {
+	case ISCSI_PARAM_SESS_RECOVERY_TMO:
+		iscsi_copy_param(ev, &value, data);
+		if (value != 0)
+			session->recovery_tmo = value;
+		break;
 	case ISCSI_PARAM_TARGET_NAME:
 		/* this should not change between logins */
 		if (session->targetname)
@@ -980,7 +1078,6 @@ iscsi_if_recv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 			ev->r.retcode = transport->start_conn(conn);
 		else
 			err = -EINVAL;
-
 		break;
 	case ISCSI_UEVENT_STOP_CONN:
 		conn = iscsi_conn_lookup(ev->u.stop_conn.sid, ev->u.stop_conn.cid);
@@ -1198,6 +1295,7 @@ static ISCSI_CLASS_ATTR(priv_sess, field, S_IRUGO, show_priv_session_##field, \
 			NULL)
 iscsi_priv_session_attr(targetname, "%s");
 iscsi_priv_session_attr(tpgt, "%d");
+iscsi_priv_session_attr(recovery_tmo, "%d");
 
 #define iscsi_priv_conn_attr_show(field, format)			\
 static ssize_t								\
@@ -1289,6 +1387,24 @@ static int iscsi_conn_match(struct attribute_container *cont,
 	return &priv->conn_cont.ac == cont;
 }
 
+static int iscsi_host_match(struct attribute_container *cont,
+			    struct device *dev)
+{
+	struct Scsi_Host *shost;
+	struct iscsi_internal *priv;
+
+	if (!scsi_is_host_device(dev))
+		return 0;
+
+	shost = dev_to_shost(dev);
+	if (!shost->transportt  ||
+	    shost->transportt->host_attrs.ac.class != &iscsi_host_class.class)
+		return 0;
+
+        priv = to_iscsi_internal(shost->transportt);
+        return &priv->t.host_attrs.ac == cont;
+}
+
 struct scsi_transport_template *
 iscsi_register_transport(struct iscsi_transport *tt)
 {
@@ -1307,6 +1423,7 @@ iscsi_register_transport(struct iscsi_transport *tt)
 		return NULL;
 	INIT_LIST_HEAD(&priv->list);
 	priv->iscsi_transport = tt;
+	priv->t.user_scan = iscsi_user_scan;
 
 	priv->cdev.class = &iscsi_transport_class;
 	snprintf(priv->cdev.class_id, BUS_ID_SIZE, "%s", tt->name);
@@ -1318,6 +1435,14 @@ iscsi_register_transport(struct iscsi_transport *tt)
 	if (err)
 		goto unregister_cdev;
 
+	/* host parameters */
+	priv->t.host_attrs.ac.attrs = &priv->host_attrs[0];
+	priv->t.host_attrs.ac.class = &iscsi_host_class.class;
+	priv->t.host_attrs.ac.match = iscsi_host_match;
+	priv->t.host_size = sizeof(struct iscsi_host);
+	priv->host_attrs[0] = NULL;
+	transport_container_register(&priv->t.host_attrs);
+
 	/* connection parameters */
 	priv->conn_cont.ac.attrs = &priv->conn_attrs[0];
 	priv->conn_cont.ac.class = &iscsi_connection_class.class;
@@ -1361,6 +1486,7 @@ iscsi_register_transport(struct iscsi_transport *tt)
 	SETUP_SESSION_RD_ATTR(data_pdu_in_order, ISCSI_PDU_INORDER_EN);
 	SETUP_SESSION_RD_ATTR(data_seq_in_order, ISCSI_DATASEQ_INORDER_EN);
 	SETUP_SESSION_RD_ATTR(erl, ISCSI_ERL);
+	SETUP_PRIV_SESSION_RD_ATTR(recovery_tmo);
 
 	if (tt->param_mask & ISCSI_TARGET_NAME)
 		SETUP_SESSION_RD_ATTR(targetname, ISCSI_TARGET_NAME);
@@ -1408,6 +1534,7 @@ int iscsi_unregister_transport(struct iscsi_transport *tt)
 
 	transport_container_unregister(&priv->conn_cont);
 	transport_container_unregister(&priv->session_cont);
+	transport_container_unregister(&priv->t.host_attrs);
 
 	sysfs_remove_group(&priv->cdev.kobj, &iscsi_transport_group);
 	class_device_unregister(&priv->cdev);
@@ -1451,10 +1578,14 @@ static __init int iscsi_transport_init(void)
 	if (err)
 		return err;
 
-	err = transport_class_register(&iscsi_connection_class);
+	err = transport_class_register(&iscsi_host_class);
 	if (err)
 		goto unregister_transport_class;
 
+	err = transport_class_register(&iscsi_connection_class);
+	if (err)
+		goto unregister_host_class;
+
 	err = transport_class_register(&iscsi_session_class);
 	if (err)
 		goto unregister_conn_class;
@@ -1482,6 +1613,8 @@ unregister_session_class:
 	transport_class_unregister(&iscsi_session_class);
 unregister_conn_class:
 	transport_class_unregister(&iscsi_connection_class);
+unregister_host_class:
+	transport_class_unregister(&iscsi_host_class);
 unregister_transport_class:
 	class_unregister(&iscsi_transport_class);
 	return err;
@@ -1494,6 +1627,7 @@ static void __exit iscsi_transport_exit(void)
 	netlink_unregister_notifier(&iscsi_nl_notifier);
 	transport_class_unregister(&iscsi_connection_class);
 	transport_class_unregister(&iscsi_session_class);
+	transport_class_unregister(&iscsi_host_class);
 	class_unregister(&iscsi_transport_class);
 }
 
diff --git a/include/scsi/iscsi_if.h b/include/scsi/iscsi_if.h
index 2c3a89b64e7..eebe2b15161 100644
--- a/include/scsi/iscsi_if.h
+++ b/include/scsi/iscsi_if.h
@@ -174,6 +174,7 @@ enum iscsi_param {
 	ISCSI_PARAM_TPGT,
 	ISCSI_PARAM_PERSISTENT_ADDRESS,
 	ISCSI_PARAM_PERSISTENT_PORT,
+	ISCSI_PARAM_SESS_RECOVERY_TMO,
 
 	/* pased in through bind conn using transport_fd */
 	ISCSI_PARAM_CONN_PORT,
@@ -201,6 +202,7 @@ enum iscsi_param {
 #define ISCSI_TPGT			(1 << ISCSI_PARAM_TPGT)
 #define ISCSI_PERSISTENT_ADDRESS	(1 << ISCSI_PARAM_PERSISTENT_ADDRESS)
 #define ISCSI_PERSISTENT_PORT		(1 << ISCSI_PARAM_PERSISTENT_PORT)
+#define ISCSI_SESS_RECOVERY_TMO		(1 << ISCSI_PARAM_SESS_RECOVERY_TMO)
 #define ISCSI_CONN_PORT			(1 << ISCSI_PARAM_CONN_PORT)
 #define ISCSI_CONN_ADDRESS		(1 << ISCSI_PARAM_CONN_ADDRESS)
 
diff --git a/include/scsi/scsi_transport_iscsi.h b/include/scsi/scsi_transport_iscsi.h
index 4b200645c84..9d2b99159ee 100644
--- a/include/scsi/scsi_transport_iscsi.h
+++ b/include/scsi/scsi_transport_iscsi.h
@@ -90,6 +90,7 @@ struct iscsi_transport {
 			 char *data, uint32_t data_size);
 	void (*get_stats) (struct iscsi_cls_conn *conn,
 			   struct iscsi_stats *stats);
+	void (*session_recovery_timedout) (struct iscsi_cls_session *session);
 };
 
 /*
@@ -130,12 +131,20 @@ struct iscsi_cls_conn {
 
 struct iscsi_cls_session {
 	struct list_head sess_list;		/* item in session_list */
+	struct list_head host_list;
 	struct iscsi_transport *transport;
 
 	/* iSCSI values used as unique id by userspace. */
 	char *targetname;
 	int tpgt;
 
+	/* recovery fields */
+	int recovery_tmo;
+	struct work_struct recovery_work;
+
+	int target_id;
+	int channel;
+
 	int sid;				/* session id */
 	void *dd_data;				/* LLD private data */
 	struct device dev;	/* sysfs transport/container device */
@@ -147,15 +156,23 @@ struct iscsi_cls_session {
 #define iscsi_session_to_shost(_session) \
 	dev_to_shost(_session->dev.parent)
 
+struct iscsi_host {
+	int next_target_id;
+	struct list_head sessions;
+	struct mutex mutex;
+};
+
 /*
  * session and connection functions that can be used by HW iSCSI LLDs
  */
 extern struct iscsi_cls_session *iscsi_create_session(struct Scsi_Host *shost,
-				struct iscsi_transport *t);
+				struct iscsi_transport *t, int channel);
 extern int iscsi_destroy_session(struct iscsi_cls_session *session);
 extern struct iscsi_cls_conn *iscsi_create_conn(struct iscsi_cls_session *sess,
 					    uint32_t cid);
 extern int iscsi_destroy_conn(struct iscsi_cls_conn *conn);
+extern void iscsi_unblock_session(struct iscsi_cls_session *session);
+extern void iscsi_block_session(struct iscsi_cls_session *session);
 
 /*
  * session functions used by software iscsi