[PATCH] fix NMI lockup with CFQ scheduler
The current problem seen is that the queue lock is actually in the
SCSI device structure, so when that structure is freed on device
release, we go boom if the queue tries to access the lock again.
The fix here is to move the lock from the scsi_device to the queue.
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 70ac286..ef1afc1 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -355,8 +355,11 @@
unsigned long queue_flags;
/*
- * protects queue structures from reentrancy
+ * protects queue structures from reentrancy. ->__queue_lock should
+ * _never_ be used directly, it is queue private. always use
+ * ->queue_lock.
*/
+ spinlock_t __queue_lock;
spinlock_t *queue_lock;
/*