scsi: core: Fix missing lock protection

async_scan_lock is designed to protect the scanning_hosts list, but there
is no protection here.

Signed-off-by: Chaohai Chen <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Bart Van Assche <[email protected]>
Signed-off-by: Martin K. Petersen <[email protected]>

Author: Chaohai Chen

drivers/scsi/scsi_scan.c

@@ -151,8 +151,9 @@ int scsi_complete_async_scans(void)
 	struct async_scan_data *data;
 
 	do {
-		if (list_empty(&scanning_hosts))
-			return 0;
+		scoped_guard(spinlock, &async_scan_lock)
+			if (list_empty(&scanning_hosts))
+				return 0;
 		/* If we can't get memory immediately, that's OK.  Just
 		 * sleep a little.  Even if we never get memory, the async
 		 * scans will finish eventually.