[SCSI] zfcp: Acquire qdio_stat_lock when reading the queue utilization
req_q_util is not atomic, so the qdio_stat_lock must be held when
reading this variable.
Reviewed-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
diff --git a/drivers/s390/scsi/zfcp_sysfs.c b/drivers/s390/scsi/zfcp_sysfs.c
index 3e51e64..0fe5cce 100644
--- a/drivers/s390/scsi/zfcp_sysfs.c
+++ b/drivers/s390/scsi/zfcp_sysfs.c
@@ -494,9 +494,14 @@
struct Scsi_Host *scsi_host = class_to_shost(dev);
struct zfcp_adapter *adapter =
(struct zfcp_adapter *) scsi_host->hostdata[0];
+ u64 util;
+
+ spin_lock_bh(&adapter->qdio_stat_lock);
+ util = adapter->req_q_util;
+ spin_unlock_bh(&adapter->qdio_stat_lock);
return sprintf(buf, "%d %llu\n", atomic_read(&adapter->qdio_outb_full),
- (unsigned long long)adapter->req_q_util);
+ (unsigned long long)util);
}
static DEVICE_ATTR(queue_full, S_IRUGO, zfcp_sysfs_adapter_q_full_show, NULL);