target: Make se_dev_check_online() locking IRQ-safe

se_dev_check_online() is called from transport_lookup_cmd_lun(), which
as discussed before may be called from interrupt context.  So it needs
to use spin_lock_irqsave() instead of spin_lock_irq() to avoid
enabling interrupts at the wrong time.

Signed-off-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

diff --git a/drivers/target/target_core_device.c b/drivers/target/target_core_device.c
index e25df3b..6d93d96 100644 (file)
--- a/drivers/target/target_core_device.c
+++ b/drivers/target/target_core_device.c
@@ -813,12 +813,13 @@ static void se_dev_stop(struct se_device *dev)
 
 int se_dev_check_online(struct se_device *dev)
 {
+       unsigned long flags;
        int ret;
 
-       spin_lock_irq(&dev->dev_status_lock);
+       spin_lock_irqsave(&dev->dev_status_lock, flags);
        ret = ((dev->dev_status & TRANSPORT_DEVICE_ACTIVATED) ||
               (dev->dev_status & TRANSPORT_DEVICE_DEACTIVATED)) ? 0 : 1;
-       spin_unlock_irq(&dev->dev_status_lock);
+       spin_unlock_irqrestore(&dev->dev_status_lock, flags);
 
        return ret;
 }