[PATCH 1/5] scsi: fix switch host state race between by sysfs and others

[Ye Bin <yebin@huaweicloud.com>]

From: Ye Bin <yebin10@huawei.com>

Now, switch host state by sysfs isn't hold 'shost->host_lock' lock.
It may race with other process, lead to host mixed 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 ee28f73af4d4..cc0ae5e3def3 100644
--- a/drivers/scsi/scsi_sysfs.c
+++ b/drivers/scsi/scsi_sysfs.c
@@ -202,6 +202,7 @@ 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;
+	unsigned long flags;
 
 	for (i = 0; i < ARRAY_SIZE(shost_states); i++) {
 		const int len = strlen(shost_states[i].name);
@@ -214,8 +215,13 @@ store_shost_state(struct device *dev, struct device_attribute *attr,
 	if (!state)
 		return -EINVAL;
 
-	if (scsi_host_set_state(shost, state))
+	spin_lock_irqsave(shost->host_lock, flags);
+	if (scsi_host_set_state(shost, state)) {
+		spin_unlock_irqrestore(shost->host_lock, flags);
 		return -EINVAL;
+	}
+	spin_unlock_irqrestore(shost->host_lock, flags);
+
 	return count;
 }
 
-- 
2.31.1