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* [PATCH 1/1] iscsi: fix regression caused by session lock patch
@ 2015-11-12  5:05 mchristi
  2015-11-12 12:03 ` Sagi Grimberg
  2016-01-22 16:50 ` Brian King
  0 siblings, 2 replies; 21+ messages in thread
From: mchristi @ 2015-11-12  5:05 UTC (permalink / raw)
  To: linux-scsi; +Cc: Mike Christie, Guilherme Piccoli

From: Mike Christie <mchristi@redhat.com>

This patch fixes this oops report by Guilherme Piccol:

list_del corruption. prev->next should be c000000f3da2b080, but was c000000f3da2c080
------------[ cut here ]------------
WARNING: at lib/list_debug.c:59
CPU: 48 PID: 12033 Comm: fio-2.2.7 Not tainted 3.18.22-354.el7_1.pkvm3_1_0.3600.1.ppc64le #1
task: c000000f25827000 ti: c000000fff5f8000 task.ti: c000000f057e4000
NIP: c0000000004d15a4 LR: c0000000004d15a0 CTR: c0000000004bdfd0
REGS: c000000fff5faf10 TRAP: 0700   Not tainted (3.18.22-354.el7_1.pkvm3_1_0.3600.1.ppc64le)
MSR: 9000000000029033 <SF,HV,EE,ME,IR,DR,RI,LE>  CR: 28082842  XER: 20000000
CFAR: c000000000988dbc SOFTE: 1
NIP [c0000000004d15a4] __list_del_entry+0xb4/0xe0
LR [c0000000004d15a0] __list_del_entry+0xb0/0xe0
Call Trace:
[c000000fff5fb190] [c0000000004d15a0] __list_del_entry+0xb0/0xe0 (unreliable)
[c000000fff5fb1f0] [d000000010fb0c8c] iscsi_complete_task+0x8c/0x190 [libiscsi]
[c000000fff5fb270] [d000000010fb24c8] __iscsi_complete_pdu+0x508/0xaa0 [libiscsi]
[c000000fff5fb350] [d000000010fb2ab4] iscsi_complete_pdu+0x54/0xa0 [libiscsi]
[c000000fff5fb3a0] [d0000000110121ac] iscsi_tcp_hdr_recv_done+0x38c/0x1250 [libiscsi_tcp]
[c000000fff5fb480] [d000000011011a48] iscsi_tcp_recv_skb+0xd8/0x4b0 [libiscsi_tcp]
[c000000fff5fb570] [d000000011071708] iscsi_sw_tcp_recv+0x98/0x170 [iscsi_tcp]
[c000000fff5fb610] [c000000000882794] tcp_read_sock+0xe4/0x2d0
[c000000fff5fb680] [d000000011071590] iscsi_sw_tcp_data_ready+0x70/0x150 [iscsi_tcp]
[c000000fff5fb720] [c0000000008921c8] tcp_rcv_established+0x3f8/0x6f0
[c000000fff5fb780] [c00000000089d75c] tcp_v4_do_rcv+0x19c/0x420
[c000000fff5fb7e0] [c0000000008a15bc] tcp_v4_rcv+0xa6c/0xb20
[c000000fff5fb8c0] [c0000000008700f8] ip_local_deliver_finish+0x178/0x350
[c000000fff5fb910] [c000000000870424] ip_rcv_finish+0x154/0x420
[c000000fff5fb990] [c000000000816bf4] __netif_receive_skb_core+0x7a4/0x9c0
[c000000fff5fba80] [c00000000081a0fc] netif_receive_skb_internal+0x4c/0xf0
[c000000fff5fbac0] [c00000000081b17c] napi_gro_receive+0xfc/0x1a0
[c000000fff5fbb00] [d000000008373280] bnx2x_rx_int+0xb30/0x1650 [bnx2x]
[c000000fff5fbc90] [d000000008374440] bnx2x_poll+0x310/0x440 [bnx2x]
[c000000fff5fbd40] [c00000000081a8e8] net_rx_action+0x2d8/0x3e0
[c000000fff5fbe10] [c0000000000cfc44] __do_softirq+0x174/0x3a0
[c000000fff5fbf00] [c0000000000d01f8] irq_exit+0xc8/0x100
[c000000fff5fbf20] [c000000000010d40] __do_irq+0xa0/0x1c0
[c000000fff5fbf90] [c000000000024aac] call_do_irq+0x14/0x24
[c000000f057e7dd0] [c000000000010f00] do_IRQ+0xa0/0x120
[c000000f057e7e30] [c0000000000025e8] hardware_interrupt_common+0x168/0x180
Instruction dump:
0fe00000 4bffffd8 3c62ff91 386304c0 484b77ad 60000000 0fe00000 4bffffc0
 3c62ff91 38630480 484b7795 60000000 <0fe00000> 4bffffa8 3c62ff91 7d254b78
---[ end trace 005d2749e6bab12f ]---

The bug is caused by this patch:

659743b02c411075b26601725947b21df0bb29c8

which allowed the task lists to be manipulated under different locks
in the xmit and completion path.

To fix the oops this patch just reverts that patch. It also reverts
these 2 patches for regressions that were also a result of that patch:

72b9740201d5f0e24b0b8326a4949786a30ff628
35843048e7e979df3b7b9f2ad49e21797a11386b

Cc: Guilherme  Piccoli <gpiccoli@linux.vnet.ibm.com>
Signed-off-by: Mike Christie <mchristi@redhat.com>
---
 drivers/scsi/be2iscsi/be_main.c  |  26 ++---
 drivers/scsi/bnx2i/bnx2i_hwi.c   |  46 ++++-----
 drivers/scsi/bnx2i/bnx2i_iscsi.c |  10 +-
 drivers/scsi/iscsi_tcp.c         |  22 ++--
 drivers/scsi/libiscsi.c          | 214 +++++++++++++++++----------------------
 drivers/scsi/libiscsi_tcp.c      |  28 ++---
 drivers/scsi/qla4xxx/ql4_isr.c   |   4 +-
 include/scsi/libiscsi.h          |  17 +---
 include/scsi/libiscsi_tcp.h      |   2 -
 9 files changed, 161 insertions(+), 208 deletions(-)

diff --git a/drivers/scsi/be2iscsi/be_main.c b/drivers/scsi/be2iscsi/be_main.c
index a4a5d6d..987cd60 100644
--- a/drivers/scsi/be2iscsi/be_main.c
+++ b/drivers/scsi/be2iscsi/be_main.c
@@ -232,20 +232,20 @@ static int beiscsi_eh_abort(struct scsi_cmnd *sc)
 	cls_session = starget_to_session(scsi_target(sc->device));
 	session = cls_session->dd_data;
 
-	spin_lock_bh(&session->frwd_lock);
+	spin_lock_bh(&session->lock);
 	if (!aborted_task || !aborted_task->sc) {
 		/* we raced */
-		spin_unlock_bh(&session->frwd_lock);
+		spin_unlock_bh(&session->lock);
 		return SUCCESS;
 	}
 
 	aborted_io_task = aborted_task->dd_data;
 	if (!aborted_io_task->scsi_cmnd) {
 		/* raced or invalid command */
-		spin_unlock_bh(&session->frwd_lock);
+		spin_unlock_bh(&session->lock);
 		return SUCCESS;
 	}
-	spin_unlock_bh(&session->frwd_lock);
+	spin_unlock_bh(&session->lock);
 	/* Invalidate WRB Posted for this Task */
 	AMAP_SET_BITS(struct amap_iscsi_wrb, invld,
 		      aborted_io_task->pwrb_handle->pwrb,
@@ -310,9 +310,9 @@ static int beiscsi_eh_device_reset(struct scsi_cmnd *sc)
 	/* invalidate iocbs */
 	cls_session = starget_to_session(scsi_target(sc->device));
 	session = cls_session->dd_data;
-	spin_lock_bh(&session->frwd_lock);
+	spin_lock_bh(&session->lock);
 	if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN) {
-		spin_unlock_bh(&session->frwd_lock);
+		spin_unlock_bh(&session->lock);
 		return FAILED;
 	}
 	conn = session->leadconn;
@@ -341,7 +341,7 @@ static int beiscsi_eh_device_reset(struct scsi_cmnd *sc)
 		num_invalidate++;
 		inv_tbl++;
 	}
-	spin_unlock_bh(&session->frwd_lock);
+	spin_unlock_bh(&session->lock);
 	inv_tbl = phba->inv_tbl;
 
 	nonemb_cmd.va = pci_alloc_consistent(phba->ctrl.pdev,
@@ -1137,9 +1137,9 @@ beiscsi_process_async_pdu(struct beiscsi_conn *beiscsi_conn,
 		return 1;
 	}
 
-	spin_lock_bh(&session->back_lock);
+	spin_lock_bh(&session->lock);
 	__iscsi_complete_pdu(conn, (struct iscsi_hdr *)ppdu, pbuffer, buf_len);
-	spin_unlock_bh(&session->back_lock);
+	spin_unlock_bh(&session->lock);
 	return 0;
 }
 
@@ -1560,7 +1560,7 @@ static void hwi_complete_cmd(struct beiscsi_conn *beiscsi_conn,
 	pwrb = pwrb_handle->pwrb;
 	type = ((struct beiscsi_io_task *)task->dd_data)->wrb_type;
 
-	spin_lock_bh(&session->back_lock);
+	spin_lock_bh(&session->lock);
 	switch (type) {
 	case HWH_TYPE_IO:
 	case HWH_TYPE_IO_RD:
@@ -1599,7 +1599,7 @@ static void hwi_complete_cmd(struct beiscsi_conn *beiscsi_conn,
 		break;
 	}
 
-	spin_unlock_bh(&session->back_lock);
+	spin_unlock_bh(&session->lock);
 }
 
 static struct list_head *hwi_get_async_busy_list(struct hwi_async_pdu_context
@@ -4688,9 +4688,9 @@ beiscsi_offload_connection(struct beiscsi_conn *beiscsi_conn,
 	 * login/startup related tasks.
 	 */
 	beiscsi_conn->login_in_progress = 0;
-	spin_lock_bh(&session->back_lock);
+	spin_lock_bh(&session->lock);
 	beiscsi_cleanup_task(task);
-	spin_unlock_bh(&session->back_lock);
+	spin_unlock_bh(&session->lock);
 
 	pwrb_handle = alloc_wrb_handle(phba, beiscsi_conn->beiscsi_conn_cid);
 
diff --git a/drivers/scsi/bnx2i/bnx2i_hwi.c b/drivers/scsi/bnx2i/bnx2i_hwi.c
index fb072cc..9bfc3d6 100644
--- a/drivers/scsi/bnx2i/bnx2i_hwi.c
+++ b/drivers/scsi/bnx2i/bnx2i_hwi.c
@@ -1363,7 +1363,7 @@ int bnx2i_process_scsi_cmd_resp(struct iscsi_session *session,
 	u32 datalen = 0;
 
 	resp_cqe = (struct bnx2i_cmd_response *)cqe;
-	spin_lock_bh(&session->back_lock);
+	spin_lock_bh(&session->lock);
 	task = iscsi_itt_to_task(conn,
 				 resp_cqe->itt & ISCSI_CMD_RESPONSE_INDEX);
 	if (!task)
@@ -1434,7 +1434,7 @@ done:
 	__iscsi_complete_pdu(conn, (struct iscsi_hdr *)hdr,
 			     conn->data, datalen);
 fail:
-	spin_unlock_bh(&session->back_lock);
+	spin_unlock_bh(&session->lock);
 	return 0;
 }
 
@@ -1459,7 +1459,7 @@ static int bnx2i_process_login_resp(struct iscsi_session *session,
 	int pad_len;
 
 	login = (struct bnx2i_login_response *) cqe;
-	spin_lock(&session->back_lock);
+	spin_lock(&session->lock);
 	task = iscsi_itt_to_task(conn,
 				 login->itt & ISCSI_LOGIN_RESPONSE_INDEX);
 	if (!task)
@@ -1502,7 +1502,7 @@ static int bnx2i_process_login_resp(struct iscsi_session *session,
 		bnx2i_conn->gen_pdu.resp_buf,
 		bnx2i_conn->gen_pdu.resp_wr_ptr - bnx2i_conn->gen_pdu.resp_buf);
 done:
-	spin_unlock(&session->back_lock);
+	spin_unlock(&session->lock);
 	return 0;
 }
 
@@ -1527,7 +1527,7 @@ static int bnx2i_process_text_resp(struct iscsi_session *session,
 	int pad_len;
 
 	text = (struct bnx2i_text_response *) cqe;
-	spin_lock(&session->back_lock);
+	spin_lock(&session->lock);
 	task = iscsi_itt_to_task(conn, text->itt & ISCSI_LOGIN_RESPONSE_INDEX);
 	if (!task)
 		goto done;
@@ -1563,7 +1563,7 @@ static int bnx2i_process_text_resp(struct iscsi_session *session,
 			     bnx2i_conn->gen_pdu.resp_wr_ptr -
 			     bnx2i_conn->gen_pdu.resp_buf);
 done:
-	spin_unlock(&session->back_lock);
+	spin_unlock(&session->lock);
 	return 0;
 }
 
@@ -1586,7 +1586,7 @@ static int bnx2i_process_tmf_resp(struct iscsi_session *session,
 	struct iscsi_tm_rsp *resp_hdr;
 
 	tmf_cqe = (struct bnx2i_tmf_response *)cqe;
-	spin_lock(&session->back_lock);
+	spin_lock(&session->lock);
 	task = iscsi_itt_to_task(conn,
 				 tmf_cqe->itt & ISCSI_TMF_RESPONSE_INDEX);
 	if (!task)
@@ -1602,7 +1602,7 @@ static int bnx2i_process_tmf_resp(struct iscsi_session *session,
 
 	__iscsi_complete_pdu(conn, (struct iscsi_hdr *)resp_hdr, NULL, 0);
 done:
-	spin_unlock(&session->back_lock);
+	spin_unlock(&session->lock);
 	return 0;
 }
 
@@ -1625,7 +1625,7 @@ static int bnx2i_process_logout_resp(struct iscsi_session *session,
 	struct iscsi_logout_rsp *resp_hdr;
 
 	logout = (struct bnx2i_logout_response *) cqe;
-	spin_lock(&session->back_lock);
+	spin_lock(&session->lock);
 	task = iscsi_itt_to_task(conn,
 				 logout->itt & ISCSI_LOGOUT_RESPONSE_INDEX);
 	if (!task)
@@ -1649,7 +1649,7 @@ static int bnx2i_process_logout_resp(struct iscsi_session *session,
 
 	bnx2i_conn->ep->state = EP_STATE_LOGOUT_RESP_RCVD;
 done:
-	spin_unlock(&session->back_lock);
+	spin_unlock(&session->lock);
 	return 0;
 }
 
@@ -1670,12 +1670,12 @@ static void bnx2i_process_nopin_local_cmpl(struct iscsi_session *session,
 	struct iscsi_task *task;
 
 	nop_in = (struct bnx2i_nop_in_msg *)cqe;
-	spin_lock(&session->back_lock);
+	spin_lock(&session->lock);
 	task = iscsi_itt_to_task(conn,
 				 nop_in->itt & ISCSI_NOP_IN_MSG_INDEX);
 	if (task)
 		__iscsi_put_task(task);
-	spin_unlock(&session->back_lock);
+	spin_unlock(&session->lock);
 }
 
 /**
@@ -1714,7 +1714,7 @@ static int bnx2i_process_nopin_mesg(struct iscsi_session *session,
 
 	nop_in = (struct bnx2i_nop_in_msg *)cqe;
 
-	spin_lock(&session->back_lock);
+	spin_lock(&session->lock);
 	hdr = (struct iscsi_nopin *)&bnx2i_conn->gen_pdu.resp_hdr;
 	memset(hdr, 0, sizeof(struct iscsi_hdr));
 	hdr->opcode = nop_in->op_code;
@@ -1740,7 +1740,7 @@ static int bnx2i_process_nopin_mesg(struct iscsi_session *session,
 	}
 done:
 	__iscsi_complete_pdu(conn, (struct iscsi_hdr *)hdr, NULL, 0);
-	spin_unlock(&session->back_lock);
+	spin_unlock(&session->lock);
 
 	return tgt_async_nop;
 }
@@ -1773,7 +1773,7 @@ static void bnx2i_process_async_mesg(struct iscsi_session *session,
 		return;
 	}
 
-	spin_lock(&session->back_lock);
+	spin_lock(&session->lock);
 	resp_hdr = (struct iscsi_async *) &bnx2i_conn->gen_pdu.resp_hdr;
 	memset(resp_hdr, 0, sizeof(struct iscsi_hdr));
 	resp_hdr->opcode = async_cqe->op_code;
@@ -1792,7 +1792,7 @@ static void bnx2i_process_async_mesg(struct iscsi_session *session,
 
 	__iscsi_complete_pdu(bnx2i_conn->cls_conn->dd_data,
 			     (struct iscsi_hdr *)resp_hdr, NULL, 0);
-	spin_unlock(&session->back_lock);
+	spin_unlock(&session->lock);
 }
 
 
@@ -1819,7 +1819,7 @@ static void bnx2i_process_reject_mesg(struct iscsi_session *session,
 	} else
 		bnx2i_unsol_pdu_adjust_rq(bnx2i_conn);
 
-	spin_lock(&session->back_lock);
+	spin_lock(&session->lock);
 	hdr = (struct iscsi_reject *) &bnx2i_conn->gen_pdu.resp_hdr;
 	memset(hdr, 0, sizeof(struct iscsi_hdr));
 	hdr->opcode = reject->op_code;
@@ -1830,7 +1830,7 @@ static void bnx2i_process_reject_mesg(struct iscsi_session *session,
 	hdr->ffffffff = cpu_to_be32(RESERVED_ITT);
 	__iscsi_complete_pdu(conn, (struct iscsi_hdr *)hdr, conn->data,
 			     reject->data_length);
-	spin_unlock(&session->back_lock);
+	spin_unlock(&session->lock);
 }
 
 /**
@@ -1850,13 +1850,13 @@ static void bnx2i_process_cmd_cleanup_resp(struct iscsi_session *session,
 	struct iscsi_task *task;
 
 	cmd_clean_rsp = (struct bnx2i_cleanup_response *)cqe;
-	spin_lock(&session->back_lock);
+	spin_lock(&session->lock);
 	task = iscsi_itt_to_task(conn,
 			cmd_clean_rsp->itt & ISCSI_CLEANUP_RESPONSE_INDEX);
 	if (!task)
 		printk(KERN_ALERT "bnx2i: cmd clean ITT %x not active\n",
 			cmd_clean_rsp->itt & ISCSI_CLEANUP_RESPONSE_INDEX);
-	spin_unlock(&session->back_lock);
+	spin_unlock(&session->lock);
 	complete(&bnx2i_conn->cmd_cleanup_cmpl);
 }
 
@@ -1923,11 +1923,11 @@ static int bnx2i_queue_scsi_cmd_resp(struct iscsi_session *session,
 	int rc = 0;
 	int cpu;
 
-	spin_lock(&session->back_lock);
+	spin_lock(&session->lock);
 	task = iscsi_itt_to_task(bnx2i_conn->cls_conn->dd_data,
 				 cqe->itt & ISCSI_CMD_RESPONSE_INDEX);
 	if (!task || !task->sc) {
-		spin_unlock(&session->back_lock);
+		spin_unlock(&session->lock);
 		return -EINVAL;
 	}
 	sc = task->sc;
@@ -1937,7 +1937,7 @@ static int bnx2i_queue_scsi_cmd_resp(struct iscsi_session *session,
 	else
 		cpu = sc->request->cpu;
 
-	spin_unlock(&session->back_lock);
+	spin_unlock(&session->lock);
 
 	p = &per_cpu(bnx2i_percpu, cpu);
 	spin_lock(&p->p_work_lock);
diff --git a/drivers/scsi/bnx2i/bnx2i_iscsi.c b/drivers/scsi/bnx2i/bnx2i_iscsi.c
index 7289437..1ef5bbb 100644
--- a/drivers/scsi/bnx2i/bnx2i_iscsi.c
+++ b/drivers/scsi/bnx2i/bnx2i_iscsi.c
@@ -1172,12 +1172,10 @@ static void bnx2i_cleanup_task(struct iscsi_task *task)
 	if (task->state == ISCSI_TASK_ABRT_TMF) {
 		bnx2i_send_cmd_cleanup_req(hba, task->dd_data);
 
-		spin_unlock_bh(&conn->session->back_lock);
-		spin_unlock_bh(&conn->session->frwd_lock);
+		spin_unlock_bh(&conn->session->lock);
 		wait_for_completion_timeout(&bnx2i_conn->cmd_cleanup_cmpl,
 				msecs_to_jiffies(ISCSI_CMD_CLEANUP_TIMEOUT));
-		spin_lock_bh(&conn->session->frwd_lock);
-		spin_lock_bh(&conn->session->back_lock);
+		spin_lock_bh(&conn->session->lock);
 	}
 	bnx2i_iscsi_unmap_sg_list(task->dd_data);
 }
@@ -2063,7 +2061,7 @@ int bnx2i_hw_ep_disconnect(struct bnx2i_endpoint *bnx2i_ep)
 		goto out;
 
 	if (session) {
-		spin_lock_bh(&session->frwd_lock);
+		spin_lock_bh(&session->lock);
 		if (bnx2i_ep->state != EP_STATE_TCP_FIN_RCVD) {
 			if (session->state == ISCSI_STATE_LOGGING_OUT) {
 				if (bnx2i_ep->state == EP_STATE_LOGOUT_SENT) {
@@ -2079,7 +2077,7 @@ int bnx2i_hw_ep_disconnect(struct bnx2i_endpoint *bnx2i_ep)
 		} else
 			close = 1;
 
-		spin_unlock_bh(&session->frwd_lock);
+		spin_unlock_bh(&session->lock);
 	}
 
 	bnx2i_ep->state = EP_STATE_DISCONN_START;
diff --git a/drivers/scsi/iscsi_tcp.c b/drivers/scsi/iscsi_tcp.c
index 0b8af18..19be12f 100644
--- a/drivers/scsi/iscsi_tcp.c
+++ b/drivers/scsi/iscsi_tcp.c
@@ -593,9 +593,9 @@ static void iscsi_sw_tcp_release_conn(struct iscsi_conn *conn)
 	iscsi_sw_tcp_conn_restore_callbacks(conn);
 	sock_put(sock->sk);
 
-	spin_lock_bh(&session->frwd_lock);
+	spin_lock_bh(&session->lock);
 	tcp_sw_conn->sock = NULL;
-	spin_unlock_bh(&session->frwd_lock);
+	spin_unlock_bh(&session->lock);
 	sockfd_put(sock);
 }
 
@@ -663,10 +663,10 @@ iscsi_sw_tcp_conn_bind(struct iscsi_cls_session *cls_session,
 	if (err)
 		goto free_socket;
 
-	spin_lock_bh(&session->frwd_lock);
+	spin_lock_bh(&session->lock);
 	/* bind iSCSI connection and socket */
 	tcp_sw_conn->sock = sock;
-	spin_unlock_bh(&session->frwd_lock);
+	spin_unlock_bh(&session->lock);
 
 	/* setup Socket parameters */
 	sk = sock->sk;
@@ -727,9 +727,9 @@ static int iscsi_sw_tcp_conn_get_param(struct iscsi_cls_conn *cls_conn,
 	case ISCSI_PARAM_CONN_PORT:
 	case ISCSI_PARAM_CONN_ADDRESS:
 	case ISCSI_PARAM_LOCAL_PORT:
-		spin_lock_bh(&conn->session->frwd_lock);
+		spin_lock_bh(&conn->session->lock);
 		if (!tcp_sw_conn || !tcp_sw_conn->sock) {
-			spin_unlock_bh(&conn->session->frwd_lock);
+			spin_unlock_bh(&conn->session->lock);
 			return -ENOTCONN;
 		}
 		if (param == ISCSI_PARAM_LOCAL_PORT)
@@ -738,7 +738,7 @@ static int iscsi_sw_tcp_conn_get_param(struct iscsi_cls_conn *cls_conn,
 		else
 			rc = kernel_getpeername(tcp_sw_conn->sock,
 						(struct sockaddr *)&addr, &len);
-		spin_unlock_bh(&conn->session->frwd_lock);
+		spin_unlock_bh(&conn->session->lock);
 		if (rc)
 			return rc;
 
@@ -767,23 +767,23 @@ static int iscsi_sw_tcp_host_get_param(struct Scsi_Host *shost,
 		if (!session)
 			return -ENOTCONN;
 
-		spin_lock_bh(&session->frwd_lock);
+		spin_lock_bh(&session->lock);
 		conn = session->leadconn;
 		if (!conn) {
-			spin_unlock_bh(&session->frwd_lock);
+			spin_unlock_bh(&session->lock);
 			return -ENOTCONN;
 		}
 		tcp_conn = conn->dd_data;
 
 		tcp_sw_conn = tcp_conn->dd_data;
 		if (!tcp_sw_conn->sock) {
-			spin_unlock_bh(&session->frwd_lock);
+			spin_unlock_bh(&session->lock);
 			return -ENOTCONN;
 		}
 
 		rc = kernel_getsockname(tcp_sw_conn->sock,
 					(struct sockaddr *)&addr, &len);
-		spin_unlock_bh(&session->frwd_lock);
+		spin_unlock_bh(&session->lock);
 		if (rc)
 			return rc;
 
diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c
index 6bffd91..6ac6c20 100644
--- a/drivers/scsi/libiscsi.c
+++ b/drivers/scsi/libiscsi.c
@@ -477,7 +477,7 @@ static int iscsi_prep_scsi_cmd_pdu(struct iscsi_task *task)
  * iscsi_free_task - free a task
  * @task: iscsi cmd task
  *
- * Must be called with session back_lock.
+ * Must be called with session lock.
  * This function returns the scsi command to scsi-ml or cleans
  * up mgmt tasks then returns the task to the pool.
  */
@@ -531,10 +531,9 @@ void iscsi_put_task(struct iscsi_task *task)
 {
 	struct iscsi_session *session = task->conn->session;
 
-	/* regular RX path uses back_lock */
-	spin_lock_bh(&session->back_lock);
+	spin_lock_bh(&session->lock);
 	__iscsi_put_task(task);
-	spin_unlock_bh(&session->back_lock);
+	spin_unlock_bh(&session->lock);
 }
 EXPORT_SYMBOL_GPL(iscsi_put_task);
 
@@ -543,7 +542,7 @@ EXPORT_SYMBOL_GPL(iscsi_put_task);
  * @task: iscsi cmd task
  * @state: state to complete task with
  *
- * Must be called with session back_lock.
+ * Must be called with session lock.
  */
 static void iscsi_complete_task(struct iscsi_task *task, int state)
 {
@@ -582,7 +581,7 @@ static void iscsi_complete_task(struct iscsi_task *task, int state)
  * This is used when drivers do not need or cannot perform
  * lower level pdu processing.
  *
- * Called with session back_lock
+ * Called with session lock
  */
 void iscsi_complete_scsi_task(struct iscsi_task *task,
 			      uint32_t exp_cmdsn, uint32_t max_cmdsn)
@@ -599,7 +598,7 @@ EXPORT_SYMBOL_GPL(iscsi_complete_scsi_task);
 
 
 /*
- * session back_lock must be held and if not called for a task that is
+ * session lock must be held and if not called for a task that is
  * still pending or from the xmit thread, then xmit thread must
  * be suspended.
  */
@@ -639,10 +638,7 @@ static void fail_scsi_task(struct iscsi_task *task, int err)
 		scsi_in(sc)->resid = scsi_in(sc)->length;
 	}
 
-	/* regular RX path uses back_lock */
-	spin_lock_bh(&conn->session->back_lock);
 	iscsi_complete_task(task, state);
-	spin_unlock_bh(&conn->session->back_lock);
 }
 
 static int iscsi_prep_mgmt_task(struct iscsi_conn *conn,
@@ -790,10 +786,7 @@ __iscsi_conn_send_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 	return task;
 
 free_task:
-	/* regular RX path uses back_lock */
-	spin_lock_bh(&session->back_lock);
 	__iscsi_put_task(task);
-	spin_unlock_bh(&session->back_lock);
 	return NULL;
 }
 
@@ -804,10 +797,10 @@ int iscsi_conn_send_pdu(struct iscsi_cls_conn *cls_conn, struct iscsi_hdr *hdr,
 	struct iscsi_session *session = conn->session;
 	int err = 0;
 
-	spin_lock_bh(&session->frwd_lock);
+	spin_lock_bh(&session->lock);
 	if (!__iscsi_conn_send_pdu(conn, hdr, data, data_size))
 		err = -EPERM;
-	spin_unlock_bh(&session->frwd_lock);
+	spin_unlock_bh(&session->lock);
 	return err;
 }
 EXPORT_SYMBOL_GPL(iscsi_conn_send_pdu);
@@ -1071,19 +1064,14 @@ static int iscsi_handle_reject(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 		if (opcode != ISCSI_OP_NOOP_OUT)
 			return 0;
 
-		 if (rejected_pdu.itt == cpu_to_be32(ISCSI_RESERVED_TAG)) {
+		 if (rejected_pdu.itt == cpu_to_be32(ISCSI_RESERVED_TAG))
 			/*
 			 * nop-out in response to target's nop-out rejected.
 			 * Just resend.
 			 */
-			/* In RX path we are under back lock */
-			spin_unlock(&conn->session->back_lock);
-			spin_lock(&conn->session->frwd_lock);
 			iscsi_send_nopout(conn,
 					  (struct iscsi_nopin*)&rejected_pdu);
-			spin_unlock(&conn->session->frwd_lock);
-			spin_lock(&conn->session->back_lock);
-		} else {
+		else {
 			struct iscsi_task *task;
 			/*
 			 * Our nop as ping got dropped. We know the target
@@ -1119,7 +1107,7 @@ static int iscsi_handle_reject(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
  * This should be used for mgmt tasks like login and nops, or if
  * the LDD's itt space does not include the session age.
  *
- * The session back_lock must be held.
+ * The session lock must be held.
  */
 struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *conn, itt_t itt)
 {
@@ -1148,7 +1136,7 @@ EXPORT_SYMBOL_GPL(iscsi_itt_to_task);
  * @datalen: len of data buffer
  *
  * Completes pdu processing by freeing any resources allocated at
- * queuecommand or send generic. session back_lock must be held and verify
+ * 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,
@@ -1185,12 +1173,7 @@ int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 			if (hdr->ttt == cpu_to_be32(ISCSI_RESERVED_TAG))
 				break;
 
-			/* In RX path we are under back lock */
-			spin_unlock(&session->back_lock);
-			spin_lock(&session->frwd_lock);
 			iscsi_send_nopout(conn, (struct iscsi_nopin*)hdr);
-			spin_unlock(&session->frwd_lock);
-			spin_lock(&session->back_lock);
 			break;
 		case ISCSI_OP_REJECT:
 			rc = iscsi_handle_reject(conn, hdr, data, datalen);
@@ -1297,9 +1280,9 @@ int iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 {
 	int rc;
 
-	spin_lock(&conn->session->back_lock);
+	spin_lock(&conn->session->lock);
 	rc = __iscsi_complete_pdu(conn, hdr, data, datalen);
-	spin_unlock(&conn->session->back_lock);
+	spin_unlock(&conn->session->lock);
 	return rc;
 }
 EXPORT_SYMBOL_GPL(iscsi_complete_pdu);
@@ -1343,7 +1326,7 @@ EXPORT_SYMBOL_GPL(iscsi_verify_itt);
  *
  * This should be used for cmd tasks.
  *
- * The session back_lock must be held.
+ * The session lock must be held.
  */
 struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *conn, itt_t itt)
 {
@@ -1373,15 +1356,15 @@ void iscsi_session_failure(struct iscsi_session *session,
 	struct iscsi_conn *conn;
 	struct device *dev;
 
-	spin_lock_bh(&session->frwd_lock);
+	spin_lock_bh(&session->lock);
 	conn = session->leadconn;
 	if (session->state == ISCSI_STATE_TERMINATE || !conn) {
-		spin_unlock_bh(&session->frwd_lock);
+		spin_unlock_bh(&session->lock);
 		return;
 	}
 
 	dev = get_device(&conn->cls_conn->dev);
-	spin_unlock_bh(&session->frwd_lock);
+	spin_unlock_bh(&session->lock);
 	if (!dev)
 	        return;
 	/*
@@ -1401,15 +1384,15 @@ void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err)
 {
 	struct iscsi_session *session = conn->session;
 
-	spin_lock_bh(&session->frwd_lock);
+	spin_lock_bh(&session->lock);
 	if (session->state == ISCSI_STATE_FAILED) {
-		spin_unlock_bh(&session->frwd_lock);
+		spin_unlock_bh(&session->lock);
 		return;
 	}
 
 	if (conn->stop_stage == 0)
 		session->state = ISCSI_STATE_FAILED;
-	spin_unlock_bh(&session->frwd_lock);
+	spin_unlock_bh(&session->lock);
 
 	set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
 	set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
@@ -1443,18 +1426,15 @@ static int iscsi_xmit_task(struct iscsi_conn *conn)
 		return -ENODATA;
 
 	__iscsi_get_task(task);
-	spin_unlock_bh(&conn->session->frwd_lock);
+	spin_unlock_bh(&conn->session->lock);
 	rc = conn->session->tt->xmit_task(task);
-	spin_lock_bh(&conn->session->frwd_lock);
+	spin_lock_bh(&conn->session->lock);
 	if (!rc) {
 		/* done with this task */
 		task->last_xfer = jiffies;
 		conn->task = NULL;
 	}
-	/* regular RX path uses back_lock */
-	spin_lock(&conn->session->back_lock);
 	__iscsi_put_task(task);
-	spin_unlock(&conn->session->back_lock);
 	return rc;
 }
 
@@ -1463,7 +1443,7 @@ static int iscsi_xmit_task(struct iscsi_conn *conn)
  * @task: task to requeue
  *
  * LLDs that need to run a task from the session workqueue should call
- * this. The session frwd_lock must be held. This should only be called
+ * this. The session lock must be held. This should only be called
  * by software drivers.
  */
 void iscsi_requeue_task(struct iscsi_task *task)
@@ -1494,10 +1474,10 @@ static int iscsi_data_xmit(struct iscsi_conn *conn)
 	struct iscsi_task *task;
 	int rc = 0;
 
-	spin_lock_bh(&conn->session->frwd_lock);
+	spin_lock_bh(&conn->session->lock);
 	if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx)) {
 		ISCSI_DBG_SESSION(conn->session, "Tx suspended!\n");
-		spin_unlock_bh(&conn->session->frwd_lock);
+		spin_unlock_bh(&conn->session->lock);
 		return -ENODATA;
 	}
 
@@ -1518,10 +1498,7 @@ check_mgmt:
 					 struct iscsi_task, running);
 		list_del_init(&conn->task->running);
 		if (iscsi_prep_mgmt_task(conn, conn->task)) {
-			/* regular RX path uses back_lock */
-			spin_lock_bh(&conn->session->back_lock);
 			__iscsi_put_task(conn->task);
-			spin_unlock_bh(&conn->session->back_lock);
 			conn->task = NULL;
 			continue;
 		}
@@ -1583,11 +1560,11 @@ check_mgmt:
 		if (!list_empty(&conn->mgmtqueue))
 			goto check_mgmt;
 	}
-	spin_unlock_bh(&conn->session->frwd_lock);
+	spin_unlock_bh(&conn->session->lock);
 	return -ENODATA;
 
 done:
-	spin_unlock_bh(&conn->session->frwd_lock);
+	spin_unlock_bh(&conn->session->lock);
 	return rc;
 }
 
@@ -1657,7 +1634,7 @@ int iscsi_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *sc)
 
 	cls_session = starget_to_session(scsi_target(sc->device));
 	session = cls_session->dd_data;
-	spin_lock_bh(&session->frwd_lock);
+	spin_lock_bh(&session->lock);
 
 	reason = iscsi_session_chkready(cls_session);
 	if (reason) {
@@ -1743,13 +1720,13 @@ int iscsi_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *sc)
 	}
 
 	session->queued_cmdsn++;
-	spin_unlock_bh(&session->frwd_lock);
+	spin_unlock_bh(&session->lock);
 	return 0;
 
 prepd_reject:
 	iscsi_complete_task(task, ISCSI_TASK_REQUEUE_SCSIQ);
 reject:
-	spin_unlock_bh(&session->frwd_lock);
+	spin_unlock_bh(&session->lock);
 	ISCSI_DBG_SESSION(session, "cmd 0x%x rejected (%d)\n",
 			  sc->cmnd[0], reason);
 	return SCSI_MLQUEUE_TARGET_BUSY;
@@ -1757,7 +1734,7 @@ reject:
 prepd_fault:
 	iscsi_complete_task(task, ISCSI_TASK_REQUEUE_SCSIQ);
 fault:
-	spin_unlock_bh(&session->frwd_lock);
+	spin_unlock_bh(&session->lock);
 	ISCSI_DBG_SESSION(session, "iscsi: cmd 0x%x is not queued (%d)\n",
 			  sc->cmnd[0], reason);
 	if (!scsi_bidi_cmnd(sc))
@@ -1786,14 +1763,14 @@ static void iscsi_tmf_timedout(unsigned long data)
 	struct iscsi_conn *conn = (struct iscsi_conn *)data;
 	struct iscsi_session *session = conn->session;
 
-	spin_lock(&session->frwd_lock);
+	spin_lock(&session->lock);
 	if (conn->tmf_state == TMF_QUEUED) {
 		conn->tmf_state = TMF_TIMEDOUT;
 		ISCSI_DBG_EH(session, "tmf timedout\n");
 		/* unblock eh_abort() */
 		wake_up(&conn->ehwait);
 	}
-	spin_unlock(&session->frwd_lock);
+	spin_unlock(&session->lock);
 }
 
 static int iscsi_exec_task_mgmt_fn(struct iscsi_conn *conn,
@@ -1806,10 +1783,10 @@ static int iscsi_exec_task_mgmt_fn(struct iscsi_conn *conn,
 	task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)hdr,
 				      NULL, 0);
 	if (!task) {
-		spin_unlock_bh(&session->frwd_lock);
+		spin_unlock_bh(&session->lock);
 		iscsi_conn_printk(KERN_ERR, conn, "Could not send TMF.\n");
 		iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
-		spin_lock_bh(&session->frwd_lock);
+		spin_lock_bh(&session->lock);
 		return -EPERM;
 	}
 	conn->tmfcmd_pdus_cnt++;
@@ -1819,7 +1796,7 @@ static int iscsi_exec_task_mgmt_fn(struct iscsi_conn *conn,
 	add_timer(&conn->tmf_timer);
 	ISCSI_DBG_EH(session, "tmf set timeout\n");
 
-	spin_unlock_bh(&session->frwd_lock);
+	spin_unlock_bh(&session->lock);
 	mutex_unlock(&session->eh_mutex);
 
 	/*
@@ -1838,7 +1815,7 @@ static int iscsi_exec_task_mgmt_fn(struct iscsi_conn *conn,
 	del_timer_sync(&conn->tmf_timer);
 
 	mutex_lock(&session->eh_mutex);
-	spin_lock_bh(&session->frwd_lock);
+	spin_lock_bh(&session->lock);
 	/* if the session drops it will clean up the task */
 	if (age != session->age ||
 	    session->state != ISCSI_STATE_LOGGED_IN)
@@ -1874,7 +1851,7 @@ static void fail_scsi_tasks(struct iscsi_conn *conn, u64 lun, int error)
  * iscsi_suspend_queue - suspend iscsi_queuecommand
  * @conn: iscsi conn to stop queueing IO on
  *
- * This grabs the session frwd_lock to make sure no one is in
+ * This grabs the session lock to make sure no one is in
  * xmit_task/queuecommand, and then sets suspend to prevent
  * new commands from being queued. This only needs to be called
  * by offload drivers that need to sync a path like ep disconnect
@@ -1883,9 +1860,9 @@ static void fail_scsi_tasks(struct iscsi_conn *conn, u64 lun, int error)
  */
 void iscsi_suspend_queue(struct iscsi_conn *conn)
 {
-	spin_lock_bh(&conn->session->frwd_lock);
+	spin_lock_bh(&conn->session->lock);
 	set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
-	spin_unlock_bh(&conn->session->frwd_lock);
+	spin_unlock_bh(&conn->session->lock);
 }
 EXPORT_SYMBOL_GPL(iscsi_suspend_queue);
 
@@ -1944,7 +1921,7 @@ static enum blk_eh_timer_return iscsi_eh_cmd_timed_out(struct scsi_cmnd *sc)
 
 	ISCSI_DBG_EH(session, "scsi cmd %p timedout\n", sc);
 
-	spin_lock(&session->frwd_lock);
+	spin_lock(&session->lock);
 	task = (struct iscsi_task *)sc->SCp.ptr;
 	if (!task) {
 		/*
@@ -2058,7 +2035,7 @@ static enum blk_eh_timer_return iscsi_eh_cmd_timed_out(struct scsi_cmnd *sc)
 done:
 	if (task)
 		task->last_timeout = jiffies;
-	spin_unlock(&session->frwd_lock);
+	spin_unlock(&session->lock);
 	ISCSI_DBG_EH(session, "return %s\n", rc == BLK_EH_RESET_TIMER ?
 		     "timer reset" : "nh");
 	return rc;
@@ -2070,7 +2047,7 @@ static void iscsi_check_transport_timeouts(unsigned long data)
 	struct iscsi_session *session = conn->session;
 	unsigned long recv_timeout, next_timeout = 0, last_recv;
 
-	spin_lock(&session->frwd_lock);
+	spin_lock(&session->lock);
 	if (session->state != ISCSI_STATE_LOGGED_IN)
 		goto done;
 
@@ -2087,7 +2064,7 @@ static void iscsi_check_transport_timeouts(unsigned long data)
 				  "last ping %lu, now %lu\n",
 				  conn->ping_timeout, conn->recv_timeout,
 				  last_recv, conn->last_ping, jiffies);
-		spin_unlock(&session->frwd_lock);
+		spin_unlock(&session->lock);
 		iscsi_conn_failure(conn, ISCSI_ERR_NOP_TIMEDOUT);
 		return;
 	}
@@ -2105,7 +2082,7 @@ static void iscsi_check_transport_timeouts(unsigned long data)
 	ISCSI_DBG_CONN(conn, "Setting next tmo %lu\n", next_timeout);
 	mod_timer(&conn->transport_timer, next_timeout);
 done:
-	spin_unlock(&session->frwd_lock);
+	spin_unlock(&session->lock);
 }
 
 static void iscsi_prep_abort_task_pdu(struct iscsi_task *task,
@@ -2135,7 +2112,7 @@ int iscsi_eh_abort(struct scsi_cmnd *sc)
 	ISCSI_DBG_EH(session, "aborting sc %p\n", sc);
 
 	mutex_lock(&session->eh_mutex);
-	spin_lock_bh(&session->frwd_lock);
+	spin_lock_bh(&session->lock);
 	/*
 	 * if session was ISCSI_STATE_IN_RECOVERY then we may not have
 	 * got the command.
@@ -2143,7 +2120,7 @@ int iscsi_eh_abort(struct scsi_cmnd *sc)
 	if (!sc->SCp.ptr) {
 		ISCSI_DBG_EH(session, "sc never reached iscsi layer or "
 				      "it completed.\n");
-		spin_unlock_bh(&session->frwd_lock);
+		spin_unlock_bh(&session->lock);
 		mutex_unlock(&session->eh_mutex);
 		return SUCCESS;
 	}
@@ -2154,7 +2131,7 @@ int iscsi_eh_abort(struct scsi_cmnd *sc)
 	 */
 	if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN ||
 	    sc->SCp.phase != session->age) {
-		spin_unlock_bh(&session->frwd_lock);
+		spin_unlock_bh(&session->lock);
 		mutex_unlock(&session->eh_mutex);
 		ISCSI_DBG_EH(session, "failing abort due to dropped "
 				  "session.\n");
@@ -2195,7 +2172,7 @@ int iscsi_eh_abort(struct scsi_cmnd *sc)
 
 	switch (conn->tmf_state) {
 	case TMF_SUCCESS:
-		spin_unlock_bh(&session->frwd_lock);
+		spin_unlock_bh(&session->lock);
 		/*
 		 * stop tx side incase the target had sent a abort rsp but
 		 * the initiator was still writing out data.
@@ -2206,15 +2183,15 @@ int iscsi_eh_abort(struct scsi_cmnd *sc)
 		 * good and have never sent us a successful tmf response
 		 * then sent more data for the cmd.
 		 */
-		spin_lock_bh(&session->frwd_lock);
+		spin_lock_bh(&session->lock);
 		fail_scsi_task(task, DID_ABORT);
 		conn->tmf_state = TMF_INITIAL;
 		memset(hdr, 0, sizeof(*hdr));
-		spin_unlock_bh(&session->frwd_lock);
+		spin_unlock_bh(&session->lock);
 		iscsi_start_tx(conn);
 		goto success_unlocked;
 	case TMF_TIMEDOUT:
-		spin_unlock_bh(&session->frwd_lock);
+		spin_unlock_bh(&session->lock);
 		iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
 		goto failed_unlocked;
 	case TMF_NOT_FOUND:
@@ -2233,7 +2210,7 @@ int iscsi_eh_abort(struct scsi_cmnd *sc)
 	}
 
 success:
-	spin_unlock_bh(&session->frwd_lock);
+	spin_unlock_bh(&session->lock);
 success_unlocked:
 	ISCSI_DBG_EH(session, "abort success [sc %p itt 0x%x]\n",
 		     sc, task->itt);
@@ -2241,7 +2218,7 @@ success_unlocked:
 	return SUCCESS;
 
 failed:
-	spin_unlock_bh(&session->frwd_lock);
+	spin_unlock_bh(&session->lock);
 failed_unlocked:
 	ISCSI_DBG_EH(session, "abort failed [sc %p itt 0x%x]\n", sc,
 		     task ? task->itt : 0);
@@ -2275,7 +2252,7 @@ int iscsi_eh_device_reset(struct scsi_cmnd *sc)
 		     sc->device->lun);
 
 	mutex_lock(&session->eh_mutex);
-	spin_lock_bh(&session->frwd_lock);
+	spin_lock_bh(&session->lock);
 	/*
 	 * Just check if we are not logged in. We cannot check for
 	 * the phase because the reset could come from a ioctl.
@@ -2302,7 +2279,7 @@ int iscsi_eh_device_reset(struct scsi_cmnd *sc)
 	case TMF_SUCCESS:
 		break;
 	case TMF_TIMEDOUT:
-		spin_unlock_bh(&session->frwd_lock);
+		spin_unlock_bh(&session->lock);
 		iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
 		goto done;
 	default:
@@ -2311,21 +2288,21 @@ int iscsi_eh_device_reset(struct scsi_cmnd *sc)
 	}
 
 	rc = SUCCESS;
-	spin_unlock_bh(&session->frwd_lock);
+	spin_unlock_bh(&session->lock);
 
 	iscsi_suspend_tx(conn);
 
-	spin_lock_bh(&session->frwd_lock);
+	spin_lock_bh(&session->lock);
 	memset(hdr, 0, sizeof(*hdr));
 	fail_scsi_tasks(conn, sc->device->lun, DID_ERROR);
 	conn->tmf_state = TMF_INITIAL;
-	spin_unlock_bh(&session->frwd_lock);
+	spin_unlock_bh(&session->lock);
 
 	iscsi_start_tx(conn);
 	goto done;
 
 unlock:
-	spin_unlock_bh(&session->frwd_lock);
+	spin_unlock_bh(&session->lock);
 done:
 	ISCSI_DBG_EH(session, "dev reset result = %s\n",
 		     rc == SUCCESS ? "SUCCESS" : "FAILED");
@@ -2338,13 +2315,13 @@ void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
 {
 	struct iscsi_session *session = cls_session->dd_data;
 
-	spin_lock_bh(&session->frwd_lock);
+	spin_lock_bh(&session->lock);
 	if (session->state != ISCSI_STATE_LOGGED_IN) {
 		session->state = ISCSI_STATE_RECOVERY_FAILED;
 		if (session->leadconn)
 			wake_up(&session->leadconn->ehwait);
 	}
-	spin_unlock_bh(&session->frwd_lock);
+	spin_unlock_bh(&session->lock);
 }
 EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
 
@@ -2366,19 +2343,19 @@ int iscsi_eh_session_reset(struct scsi_cmnd *sc)
 	conn = session->leadconn;
 
 	mutex_lock(&session->eh_mutex);
-	spin_lock_bh(&session->frwd_lock);
+	spin_lock_bh(&session->lock);
 	if (session->state == ISCSI_STATE_TERMINATE) {
 failed:
 		ISCSI_DBG_EH(session,
 			     "failing session reset: Could not log back into "
 			     "%s, %s [age %d]\n", session->targetname,
 			     conn->persistent_address, session->age);
-		spin_unlock_bh(&session->frwd_lock);
+		spin_unlock_bh(&session->lock);
 		mutex_unlock(&session->eh_mutex);
 		return FAILED;
 	}
 
-	spin_unlock_bh(&session->frwd_lock);
+	spin_unlock_bh(&session->lock);
 	mutex_unlock(&session->eh_mutex);
 	/*
 	 * we drop the lock here but the leadconn cannot be destoyed while
@@ -2395,14 +2372,14 @@ failed:
 		flush_signals(current);
 
 	mutex_lock(&session->eh_mutex);
-	spin_lock_bh(&session->frwd_lock);
+	spin_lock_bh(&session->lock);
 	if (session->state == ISCSI_STATE_LOGGED_IN) {
 		ISCSI_DBG_EH(session,
 			     "session reset succeeded for %s,%s\n",
 			     session->targetname, conn->persistent_address);
 	} else
 		goto failed;
-	spin_unlock_bh(&session->frwd_lock);
+	spin_unlock_bh(&session->lock);
 	mutex_unlock(&session->eh_mutex);
 	return SUCCESS;
 }
@@ -2438,7 +2415,7 @@ int iscsi_eh_target_reset(struct scsi_cmnd *sc)
 		     session->targetname);
 
 	mutex_lock(&session->eh_mutex);
-	spin_lock_bh(&session->frwd_lock);
+	spin_lock_bh(&session->lock);
 	/*
 	 * Just check if we are not logged in. We cannot check for
 	 * the phase because the reset could come from a ioctl.
@@ -2465,7 +2442,7 @@ int iscsi_eh_target_reset(struct scsi_cmnd *sc)
 	case TMF_SUCCESS:
 		break;
 	case TMF_TIMEDOUT:
-		spin_unlock_bh(&session->frwd_lock);
+		spin_unlock_bh(&session->lock);
 		iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
 		goto done;
 	default:
@@ -2474,21 +2451,21 @@ int iscsi_eh_target_reset(struct scsi_cmnd *sc)
 	}
 
 	rc = SUCCESS;
-	spin_unlock_bh(&session->frwd_lock);
+	spin_unlock_bh(&session->lock);
 
 	iscsi_suspend_tx(conn);
 
-	spin_lock_bh(&session->frwd_lock);
+	spin_lock_bh(&session->lock);
 	memset(hdr, 0, sizeof(*hdr));
 	fail_scsi_tasks(conn, -1, DID_ERROR);
 	conn->tmf_state = TMF_INITIAL;
-	spin_unlock_bh(&session->frwd_lock);
+	spin_unlock_bh(&session->lock);
 
 	iscsi_start_tx(conn);
 	goto done;
 
 unlock:
-	spin_unlock_bh(&session->frwd_lock);
+	spin_unlock_bh(&session->lock);
 done:
 	ISCSI_DBG_EH(session, "tgt %s reset result = %s\n", session->targetname,
 		     rc == SUCCESS ? "SUCCESS" : "FAILED");
@@ -2786,10 +2763,8 @@ iscsi_session_setup(struct iscsi_transport *iscsit, struct Scsi_Host *shost,
 	session->max_r2t = 1;
 	session->tt = iscsit;
 	session->dd_data = cls_session->dd_data + sizeof(*session);
-
 	mutex_init(&session->eh_mutex);
-	spin_lock_init(&session->frwd_lock);
-	spin_lock_init(&session->back_lock);
+	spin_lock_init(&session->lock);
 
 	/* initialize SCSI PDU commands pool */
 	if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
@@ -2903,14 +2878,14 @@ iscsi_conn_setup(struct iscsi_cls_session *cls_session, int dd_size,
 	INIT_WORK(&conn->xmitwork, iscsi_xmitworker);
 
 	/* allocate login_task used for the login/text sequences */
-	spin_lock_bh(&session->frwd_lock);
+	spin_lock_bh(&session->lock);
 	if (!kfifo_out(&session->cmdpool.queue,
                          (void*)&conn->login_task,
 			 sizeof(void*))) {
-		spin_unlock_bh(&session->frwd_lock);
+		spin_unlock_bh(&session->lock);
 		goto login_task_alloc_fail;
 	}
-	spin_unlock_bh(&session->frwd_lock);
+	spin_unlock_bh(&session->lock);
 
 	data = (char *) __get_free_pages(GFP_KERNEL,
 					 get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
@@ -2947,7 +2922,7 @@ void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
 	del_timer_sync(&conn->transport_timer);
 
 	mutex_lock(&session->eh_mutex);
-	spin_lock_bh(&session->frwd_lock);
+	spin_lock_bh(&session->lock);
 	conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
 	if (session->leadconn == conn) {
 		/*
@@ -2956,24 +2931,21 @@ void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
 		session->state = ISCSI_STATE_TERMINATE;
 		wake_up(&conn->ehwait);
 	}
-	spin_unlock_bh(&session->frwd_lock);
+	spin_unlock_bh(&session->lock);
 
 	/* flush queued up work because we free the connection below */
 	iscsi_suspend_tx(conn);
 
-	spin_lock_bh(&session->frwd_lock);
+	spin_lock_bh(&session->lock);
 	free_pages((unsigned long) conn->data,
 		   get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
 	kfree(conn->persistent_address);
 	kfree(conn->local_ipaddr);
-	/* regular RX path uses back_lock */
-	spin_lock_bh(&session->back_lock);
 	kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
 		    sizeof(void*));
-	spin_unlock_bh(&session->back_lock);
 	if (session->leadconn == conn)
 		session->leadconn = NULL;
-	spin_unlock_bh(&session->frwd_lock);
+	spin_unlock_bh(&session->lock);
 	mutex_unlock(&session->eh_mutex);
 
 	iscsi_destroy_conn(cls_conn);
@@ -3011,7 +2983,7 @@ int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
 		conn->ping_timeout = 5;
 	}
 
-	spin_lock_bh(&session->frwd_lock);
+	spin_lock_bh(&session->lock);
 	conn->c_stage = ISCSI_CONN_STARTED;
 	session->state = ISCSI_STATE_LOGGED_IN;
 	session->queued_cmdsn = session->cmdsn;
@@ -3040,7 +3012,7 @@ int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
 	default:
 		break;
 	}
-	spin_unlock_bh(&session->frwd_lock);
+	spin_unlock_bh(&session->lock);
 
 	iscsi_unblock_session(session->cls_session);
 	wake_up(&conn->ehwait);
@@ -3079,9 +3051,9 @@ static void iscsi_start_session_recovery(struct iscsi_session *session,
 	int old_stop_stage;
 
 	mutex_lock(&session->eh_mutex);
-	spin_lock_bh(&session->frwd_lock);
+	spin_lock_bh(&session->lock);
 	if (conn->stop_stage == STOP_CONN_TERM) {
-		spin_unlock_bh(&session->frwd_lock);
+		spin_unlock_bh(&session->lock);
 		mutex_unlock(&session->eh_mutex);
 		return;
 	}
@@ -3098,14 +3070,14 @@ static void iscsi_start_session_recovery(struct iscsi_session *session,
 
 	old_stop_stage = conn->stop_stage;
 	conn->stop_stage = flag;
-	spin_unlock_bh(&session->frwd_lock);
+	spin_unlock_bh(&session->lock);
 
 	del_timer_sync(&conn->transport_timer);
 	iscsi_suspend_tx(conn);
 
-	spin_lock_bh(&session->frwd_lock);
+	spin_lock_bh(&session->lock);
 	conn->c_stage = ISCSI_CONN_STOPPED;
-	spin_unlock_bh(&session->frwd_lock);
+	spin_unlock_bh(&session->lock);
 
 	/*
 	 * for connection level recovery we should not calculate
@@ -3126,11 +3098,11 @@ static void iscsi_start_session_recovery(struct iscsi_session *session,
 	/*
 	 * flush queues.
 	 */
-	spin_lock_bh(&session->frwd_lock);
+	spin_lock_bh(&session->lock);
 	fail_scsi_tasks(conn, -1, DID_TRANSPORT_DISRUPTED);
 	fail_mgmt_tasks(session, conn);
 	memset(&conn->tmhdr, 0, sizeof(conn->tmhdr));
-	spin_unlock_bh(&session->frwd_lock);
+	spin_unlock_bh(&session->lock);
 	mutex_unlock(&session->eh_mutex);
 }
 
@@ -3157,10 +3129,10 @@ int iscsi_conn_bind(struct iscsi_cls_session *cls_session,
 	struct iscsi_session *session = cls_session->dd_data;
 	struct iscsi_conn *conn = cls_conn->dd_data;
 
-	spin_lock_bh(&session->frwd_lock);
+	spin_lock_bh(&session->lock);
 	if (is_leading)
 		session->leadconn = conn;
-	spin_unlock_bh(&session->frwd_lock);
+	spin_unlock_bh(&session->lock);
 
 	/*
 	 * Unblock xmitworker(), Login Phase will pass through.
diff --git a/drivers/scsi/libiscsi_tcp.c b/drivers/scsi/libiscsi_tcp.c
index 60cb6dc..2f738dd 100644
--- a/drivers/scsi/libiscsi_tcp.c
+++ b/drivers/scsi/libiscsi_tcp.c
@@ -446,7 +446,7 @@ iscsi_tcp_data_recv_prep(struct iscsi_tcp_conn *tcp_conn)
  * iscsi_tcp_cleanup_task - free tcp_task resources
  * @task: iscsi task
  *
- * must be called with session back_lock
+ * must be called with session lock
  */
 void iscsi_tcp_cleanup_task(struct iscsi_task *task)
 {
@@ -457,7 +457,6 @@ void iscsi_tcp_cleanup_task(struct iscsi_task *task)
 	if (!task->sc)
 		return;
 
-	spin_lock_bh(&tcp_task->queue2pool);
 	/* flush task's r2t queues */
 	while (kfifo_out(&tcp_task->r2tqueue, (void*)&r2t, sizeof(void*))) {
 		kfifo_in(&tcp_task->r2tpool.queue, (void*)&r2t,
@@ -471,7 +470,6 @@ void iscsi_tcp_cleanup_task(struct iscsi_task *task)
 			    sizeof(void*));
 		tcp_task->r2t = NULL;
 	}
-	spin_unlock_bh(&tcp_task->queue2pool);
 }
 EXPORT_SYMBOL_GPL(iscsi_tcp_cleanup_task);
 
@@ -579,13 +577,11 @@ static int iscsi_tcp_r2t_rsp(struct iscsi_conn *conn, struct iscsi_task *task)
 		return ISCSI_ERR_DATALEN;
 	}
 
-	spin_lock(&tcp_task->pool2queue);
 	rc = kfifo_out(&tcp_task->r2tpool.queue, (void *)&r2t, sizeof(void *));
 	if (!rc) {
 		iscsi_conn_printk(KERN_ERR, conn, "Could not allocate R2T. "
 				  "Target has sent more R2Ts than it "
 				  "negotiated for or driver has leaked.\n");
-		spin_unlock(&tcp_task->pool2queue);
 		return ISCSI_ERR_PROTO;
 	}
 
@@ -600,7 +596,6 @@ static int iscsi_tcp_r2t_rsp(struct iscsi_conn *conn, struct iscsi_task *task)
 	tcp_task->exp_datasn = r2tsn + 1;
 	kfifo_in(&tcp_task->r2tqueue, (void*)&r2t, sizeof(void*));
 	conn->r2t_pdus_cnt++;
-	spin_unlock(&tcp_task->pool2queue);
 
 	iscsi_requeue_task(task);
 	return 0;
@@ -673,14 +668,14 @@ iscsi_tcp_hdr_dissect(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
 
 	switch(opcode) {
 	case ISCSI_OP_SCSI_DATA_IN:
-		spin_lock(&conn->session->back_lock);
+		spin_lock(&conn->session->lock);
 		task = iscsi_itt_to_ctask(conn, hdr->itt);
 		if (!task)
 			rc = ISCSI_ERR_BAD_ITT;
 		else
 			rc = iscsi_tcp_data_in(conn, task);
 		if (rc) {
-			spin_unlock(&conn->session->back_lock);
+			spin_unlock(&conn->session->lock);
 			break;
 		}
 
@@ -713,11 +708,11 @@ iscsi_tcp_hdr_dissect(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
 						   tcp_conn->in.datalen,
 						   iscsi_tcp_process_data_in,
 						   rx_hash);
-			spin_unlock(&conn->session->back_lock);
+			spin_unlock(&conn->session->lock);
 			return rc;
 		}
 		rc = __iscsi_complete_pdu(conn, hdr, NULL, 0);
-		spin_unlock(&conn->session->back_lock);
+		spin_unlock(&conn->session->lock);
 		break;
 	case ISCSI_OP_SCSI_CMD_RSP:
 		if (tcp_conn->in.datalen) {
@@ -727,20 +722,18 @@ iscsi_tcp_hdr_dissect(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
 		rc = iscsi_complete_pdu(conn, hdr, NULL, 0);
 		break;
 	case ISCSI_OP_R2T:
-		spin_lock(&conn->session->back_lock);
+		spin_lock(&conn->session->lock);
 		task = iscsi_itt_to_ctask(conn, hdr->itt);
-		spin_unlock(&conn->session->back_lock);
 		if (!task)
 			rc = ISCSI_ERR_BAD_ITT;
 		else if (ahslen)
 			rc = ISCSI_ERR_AHSLEN;
 		else if (task->sc->sc_data_direction == DMA_TO_DEVICE) {
 			task->last_xfer = jiffies;
-			spin_lock(&conn->session->frwd_lock);
 			rc = iscsi_tcp_r2t_rsp(conn, task);
-			spin_unlock(&conn->session->frwd_lock);
 		} else
 			rc = ISCSI_ERR_PROTO;
+		spin_unlock(&conn->session->lock);
 		break;
 	case ISCSI_OP_LOGIN_RSP:
 	case ISCSI_OP_TEXT_RSP:
@@ -988,13 +981,14 @@ EXPORT_SYMBOL_GPL(iscsi_tcp_task_init);
 
 static struct iscsi_r2t_info *iscsi_tcp_get_curr_r2t(struct iscsi_task *task)
 {
+	struct iscsi_session *session = task->conn->session;
 	struct iscsi_tcp_task *tcp_task = task->dd_data;
 	struct iscsi_r2t_info *r2t = NULL;
 
 	if (iscsi_task_has_unsol_data(task))
 		r2t = &task->unsol_r2t;
 	else {
-		spin_lock_bh(&tcp_task->queue2pool);
+		spin_lock_bh(&session->lock);
 		if (tcp_task->r2t) {
 			r2t = tcp_task->r2t;
 			/* Continue with this R2T? */
@@ -1016,7 +1010,7 @@ static struct iscsi_r2t_info *iscsi_tcp_get_curr_r2t(struct iscsi_task *task)
 			else
 				r2t = tcp_task->r2t;
 		}
-		spin_unlock_bh(&tcp_task->queue2pool);
+		spin_unlock_bh(&session->lock);
 	}
 
 	return r2t;
@@ -1146,8 +1140,6 @@ int iscsi_tcp_r2tpool_alloc(struct iscsi_session *session)
 			iscsi_pool_free(&tcp_task->r2tpool);
 			goto r2t_alloc_fail;
 		}
-		spin_lock_init(&tcp_task->pool2queue);
-		spin_lock_init(&tcp_task->queue2pool);
 	}
 
 	return 0;
diff --git a/drivers/scsi/qla4xxx/ql4_isr.c b/drivers/scsi/qla4xxx/ql4_isr.c
index 4f9c0f2..79b278b 100644
--- a/drivers/scsi/qla4xxx/ql4_isr.c
+++ b/drivers/scsi/qla4xxx/ql4_isr.c
@@ -385,9 +385,9 @@ static void qla4xxx_passthru_status_entry(struct scsi_qla_host *ha,
 
 	cls_conn = ddb_entry->conn;
 	conn = cls_conn->dd_data;
-	spin_lock(&conn->session->back_lock);
+	spin_lock(&conn->session->lock);
 	task = iscsi_itt_to_task(conn, itt);
-	spin_unlock(&conn->session->back_lock);
+	spin_unlock(&conn->session->lock);
 
 	if (task == NULL) {
 		ql4_printk(KERN_ERR, ha, "%s: Task is NULL\n", __func__);
diff --git a/include/scsi/libiscsi.h b/include/scsi/libiscsi.h
index 4d1c46a..52d858c 100644
--- a/include/scsi/libiscsi.h
+++ b/include/scsi/libiscsi.h
@@ -331,19 +331,12 @@ struct iscsi_session {
 	struct iscsi_transport	*tt;
 	struct Scsi_Host	*host;
 	struct iscsi_conn	*leadconn;	/* leading connection */
-	/* Between the forward and the backward locks exists a strict locking
-	 * hierarchy. The mutual exclusion zone protected by the forward lock
-	 * can enclose the mutual exclusion zone protected by the backward lock
-	 * but not vice versa.
-	 */
-	spinlock_t		frwd_lock;	/* protects session state, *
-						 * cmdsn, queued_cmdsn     *
+	spinlock_t		lock;		/* protects session state, *
+						 * sequence numbers,       *
 						 * session resources:      *
-						 * - cmdpool kfifo_out ,   *
-						 * - mgmtpool,		   */
-	spinlock_t		back_lock;	/* protects cmdsn_exp      *
-						 * cmdsn_max,              *
-						 * cmdpool kfifo_in        */
+						 * - cmdpool,		   *
+						 * - mgmtpool,		   *
+						 * - r2tpool		   */
 	int			state;		/* session state           */
 	int			age;		/* counts session re-opens */
 
diff --git a/include/scsi/libiscsi_tcp.h b/include/scsi/libiscsi_tcp.h
index 2a7aa75..215469a 100644
--- a/include/scsi/libiscsi_tcp.h
+++ b/include/scsi/libiscsi_tcp.h
@@ -83,8 +83,6 @@ struct iscsi_tcp_task {
 	struct iscsi_pool	r2tpool;
 	struct kfifo		r2tqueue;
 	void			*dd_data;
-	spinlock_t		pool2queue;
-	spinlock_t		queue2pool;
 };
 
 enum {
-- 
1.8.3.1


^ permalink raw reply related	[flat|nested] 21+ messages in thread

end of thread, other threads:[~2017-02-06 19:22 UTC | newest]

Thread overview: 21+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2015-11-12  5:05 [PATCH 1/1] iscsi: fix regression caused by session lock patch mchristi
2015-11-12 12:03 ` Sagi Grimberg
2015-11-12 20:58   ` Mike Christie
2015-11-13 15:06     ` Or Gerlitz
2015-11-13 16:51       ` Mike Christie
2015-11-15 10:10         ` Or Gerlitz
     [not found]           ` <CAJ3xEMhQiywXo0=kRO7f=fW--1kc6mbNs_X7wLoYtXmRWeqBkg-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2015-11-16 17:30             ` Michael Christie
2015-11-17 16:55               ` Or Gerlitz
2015-11-18 11:30               ` Or Gerlitz
     [not found]                 ` <CAJ3xEMiu4XBO2d1oLnrgay1uLQmY871n9Kn-yp73PAkfKNnp9A-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2015-11-18 18:39                   ` Mike Christie
2016-11-07 18:15             ` Chris Leech
     [not found]               ` <20161107181556.cnhwst4nu63xtrqk-r8IHplWLGbA5tHQWs+pTeqPFFGjUI2lm2LY78lusg7I@public.gmane.org>
2016-11-07 18:23                 ` Guilherme G. Piccoli
     [not found]                   ` <5820C68E.6050206-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
2016-11-09  5:21                     ` Chris Leech
     [not found]                       ` <20161109052142.j4psips7yvx7uohx-r8IHplWLGbA5tHQWs+pTeqPFFGjUI2lm2LY78lusg7I@public.gmane.org>
2016-11-12  1:51                         ` Guilherme G. Piccoli
2017-02-06 13:19                         ` Guilherme G. Piccoli
     [not found]                           ` <631008bd-1e05-2c88-b153-695c76128eb4-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
2017-02-06 17:27                             ` Chris Leech
     [not found]                               ` <1976057129.23970152.1486402069647.JavaMail.zimbra-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2017-02-06 18:24                                 ` Guilherme G. Piccoli
2017-02-06 19:22                                   ` Sagi Grimberg
2015-11-12 21:33   ` Chris Leech
2016-01-22 16:50 ` Brian King
2016-01-22 19:11   ` Mike Christie

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