[PATCH 3/5] scsi: limit to set the host state

[Ye Bin <yebin@huaweicloud.com>]

From: Ye Bin <yebin10@huawei.com>

Now, we can set the host state with any value. Actually, it doesn't
make sense. As previous patch introduce SHOST_BLOCKED state, set this
state, it will blocking IO. So this patch limit to set the host with
running/blocked state.

Signed-off-by: Ye Bin <yebin10@huawei.com>
---
 drivers/scsi/scsi_sysfs.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c
index b14f95ac594e..42c5936c7711 100644
--- a/drivers/scsi/scsi_sysfs.c
+++ b/drivers/scsi/scsi_sysfs.c
@@ -203,6 +203,7 @@ store_shost_state(struct device *dev, struct device_attribute *attr,
 	int i;
 	struct Scsi_Host *shost = class_to_shost(dev);
 	enum scsi_host_state state = 0;
+	enum scsi_host_state old_state;
 	unsigned long flags;
 
 	for (i = 0; i < ARRAY_SIZE(shost_states); i++) {
@@ -216,8 +217,13 @@ store_shost_state(struct device *dev, struct device_attribute *attr,
 	if (!state)
 		return -EINVAL;
 
+	if (state != SHOST_RUNNING && state != SHOST_BLOCKED)
+		return -EINVAL;
+
 	spin_lock_irqsave(shost->host_lock, flags);
-	if (scsi_host_set_state(shost, state)) {
+	old_state = shost->shost_state;
+	if ((old_state != SHOST_RUNNING && old_state != SHOST_BLOCKED) ||
+	    scsi_host_set_state(shost, state)) {
 		spin_unlock_irqrestore(shost->host_lock, flags);
 		return -EINVAL;
 	}
-- 
2.31.1