[RFC PATCH v2 18/19] scsi: virtio_scsi: 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
virtio_scsi did not define other further reset callbacks, it is not
necessary to fallback to further recover any more, so set the LUN
error handler with fallback set to 0.

Signed-off-by: Wenchao Hao <haowenchao2@huawei.com>
---
 drivers/scsi/virtio_scsi.c | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/virtio_scsi.c b/drivers/scsi/virtio_scsi.c
index bd5633667d01..7bf4a34cdd20 100644
--- a/drivers/scsi/virtio_scsi.c
+++ b/drivers/scsi/virtio_scsi.c
@@ -28,6 +28,7 @@
 #include <scsi/scsi_cmnd.h>
 #include <scsi/scsi_tcq.h>
 #include <scsi/scsi_devinfo.h>
+#include <scsi/scsi_eh.h>
 #include <linux/seqlock.h>
 #include <linux/blk-mq-virtio.h>
 
@@ -37,6 +38,10 @@
 #define VIRTIO_SCSI_EVENT_LEN 8
 #define VIRTIO_SCSI_VQ_BASE 2
 
+static bool lun_eh;
+module_param(lun_eh, bool, 0444);
+MODULE_PARM_DESC(lun_eh, "LUN based error handle (def=0)");
+
 /* Command queue element */
 struct virtio_scsi_cmd {
 	struct scsi_cmnd *sc;
@@ -679,9 +684,18 @@ static int virtscsi_device_alloc(struct scsi_device *sdevice)
 	 */
 	sdevice->sdev_bflags = BLIST_TRY_VPD_PAGES;
 
+	if (lun_eh)
+		return scsi_device_setup_eh(sdevice, 0);
+
 	return 0;
 }
 
+static void virtscsi_device_destroy(struct scsi_device *sdevice)
+{
+	if (lun_eh)
+		return scsi_device_clear_eh(sdevice);
+}
+
 
 /**
  * virtscsi_change_queue_depth() - Change a virtscsi target's queue depth
@@ -757,7 +771,7 @@ static const struct scsi_host_template virtscsi_host_template = {
 	.eh_device_reset_handler = virtscsi_device_reset,
 	.eh_timed_out = virtscsi_eh_timed_out,
 	.slave_alloc = virtscsi_device_alloc,
-
+	.slave_destroy = virtscsi_device_destroy,
 	.dma_boundary = UINT_MAX,
 	.map_queues = virtscsi_map_queues,
 	.track_queue_depth = 1,
-- 
2.35.3