[RFC PATCH v2 19/19] scsi: iscsi_tcp: Add param to control LUN based error handle

[Wenchao Hao <haowenchao2@huawei.com>]

Add new param lun_eh to control if enable LUN based error handler,
since iscsi_tcp defined callback eh_target_reset, so make it
fallback to further recover when LUN based recovery can not recover
all error commands.

Signed-off-by: Wenchao Hao <haowenchao2@huawei.com>
---
 drivers/scsi/iscsi_tcp.c | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/drivers/scsi/iscsi_tcp.c b/drivers/scsi/iscsi_tcp.c
index 9ab8555180a3..83474dc0ecd5 100644
--- a/drivers/scsi/iscsi_tcp.c
+++ b/drivers/scsi/iscsi_tcp.c
@@ -35,6 +35,7 @@
 #include <scsi/scsi_host.h>
 #include <scsi/scsi.h>
 #include <scsi/scsi_transport_iscsi.h>
+#include <scsi/scsi_eh.h>
 #include <trace/events/iscsi.h>
 #include <trace/events/sock.h>
 
@@ -63,6 +64,10 @@ module_param_named(debug_iscsi_tcp, iscsi_sw_tcp_dbg, int,
 MODULE_PARM_DESC(debug_iscsi_tcp, "Turn on debugging for iscsi_tcp module "
 		 "Set to 1 to turn on, and zero to turn off. Default is off.");
 
+static bool iscsi_sw_tcp_lun_eh;
+module_param_named(lun_eh, iscsi_sw_tcp_lun_eh, bool, 0444);
+MODULE_PARM_DESC(lun_eh, "LUN based error handle (def=0)");
+
 #define ISCSI_SW_TCP_DBG(_conn, dbg_fmt, arg...)		\
 	do {							\
 		if (iscsi_sw_tcp_dbg)				\
@@ -1065,6 +1070,19 @@ static int iscsi_sw_tcp_slave_configure(struct scsi_device *sdev)
 	return 0;
 }
 
+static int iscsi_sw_tcp_slave_alloc(struct scsi_device *sdev)
+{
+	if (iscsi_sw_tcp_lun_eh)
+		return scsi_device_setup_eh(sdev, 1);
+	return 0;
+}
+
+static void iscsi_sw_tcp_slave_destroy(struct scsi_device *sdev)
+{
+	if (iscsi_sw_tcp_lun_eh)
+		return scsi_device_clear_eh(sdev);
+}
+
 static const struct scsi_host_template iscsi_sw_tcp_sht = {
 	.module			= THIS_MODULE,
 	.name			= "iSCSI Initiator over TCP/IP",
@@ -1080,6 +1098,8 @@ static const struct scsi_host_template iscsi_sw_tcp_sht = {
 	.eh_target_reset_handler = iscsi_eh_recover_target,
 	.dma_boundary		= PAGE_SIZE - 1,
 	.slave_configure        = iscsi_sw_tcp_slave_configure,
+	.slave_alloc		= iscsi_sw_tcp_slave_alloc,
+	.slave_destroy		= iscsi_sw_tcp_slave_destroy,
 	.proc_name		= "iscsi_tcp",
 	.this_id		= -1,
 	.track_queue_depth	= 1,
-- 
2.35.3