[PATCH 2/5] scsi: introduce SHOST_BLOCKED state to support blocking IO

[Ye Bin <yebin@huaweicloud.com>]

From: Ye Bin <yebin10@huawei.com>

SHOST_BLOCKED state to blocking io in block layer. This state use for
test, Only running state and blocked state can be switched to each
other.

Signed-off-by: Ye Bin <yebin10@huawei.com>
---
 drivers/scsi/hosts.c      | 11 +++++++++++
 drivers/scsi/scsi_sysfs.c |  1 +
 include/scsi/scsi_host.h  |  1 +
 3 files changed, 13 insertions(+)

diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c
index 9b6fbbe15d92..3b497fd4d329 100644
--- a/drivers/scsi/hosts.c
+++ b/drivers/scsi/hosts.c
@@ -90,6 +90,7 @@ int scsi_host_set_state(struct Scsi_Host *shost, enum scsi_host_state state)
 		switch (oldstate) {
 		case SHOST_CREATED:
 		case SHOST_RECOVERY:
+		case SHOST_BLOCKED:
 			break;
 		default:
 			goto illegal;
@@ -99,6 +100,7 @@ int scsi_host_set_state(struct Scsi_Host *shost, enum scsi_host_state state)
 	case SHOST_RECOVERY:
 		switch (oldstate) {
 		case SHOST_RUNNING:
+		case SHOST_BLOCKED:
 			break;
 		default:
 			goto illegal;
@@ -109,6 +111,7 @@ int scsi_host_set_state(struct Scsi_Host *shost, enum scsi_host_state state)
 		switch (oldstate) {
 		case SHOST_CREATED:
 		case SHOST_RUNNING:
+		case SHOST_BLOCKED:
 		case SHOST_CANCEL_RECOVERY:
 			break;
 		default:
@@ -144,6 +147,14 @@ int scsi_host_set_state(struct Scsi_Host *shost, enum scsi_host_state state)
 			goto illegal;
 		}
 		break;
+	case SHOST_BLOCKED:
+		switch (oldstate) {
+		case SHOST_RUNNING:
+			break;
+		default:
+			goto illegal;
+		}
+		break;
 	}
 	shost->shost_state = state;
 	return 0;
diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c
index cc0ae5e3def3..b14f95ac594e 100644
--- a/drivers/scsi/scsi_sysfs.c
+++ b/drivers/scsi/scsi_sysfs.c
@@ -69,6 +69,7 @@ static const struct {
 	{ SHOST_RECOVERY, "recovery" },
 	{ SHOST_CANCEL_RECOVERY, "cancel/recovery" },
 	{ SHOST_DEL_RECOVERY, "deleted/recovery", },
+	{ SHOST_BLOCKED, "blocked", },
 };
 const char *scsi_host_state_name(enum scsi_host_state state)
 {
diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
index 587cc767bb67..9e99317b11fa 100644
--- a/include/scsi/scsi_host.h
+++ b/include/scsi/scsi_host.h
@@ -527,6 +527,7 @@ enum scsi_host_state {
 	SHOST_RECOVERY,
 	SHOST_CANCEL_RECOVERY,
 	SHOST_DEL_RECOVERY,
+	SHOST_BLOCKED,
 };
 
 struct Scsi_Host {
-- 
2.31.1