Use O_DIRECT for all IO to devices.

Using buffered IO risks non-atomic updates to parts of the
device that we don't actually want to write to.  This isn't in
general safe.
So switch to O_DIRECT for all that IO and make sure we have
properly aligned buffers.

1 files changed, 5 insertions, 0 deletions

diff --git a/mdadm.h b/mdadm.h
index 5e2cfe4..8a94035 100644
--- a/mdadm.h
+++ b/mdadm.h
@@ -791,6 +791,11 @@ static inline int dev2minor(int d)
 	return (-1-d) << MdpMinorShift;
 }
 
+static inline int ROUND_UP(int a, int base)
+{
+	return ((a+base-1)/base)*base;
+}
+
 #define	LEVEL_MULTIPATH		(-4)
 #define	LEVEL_LINEAR		(-1)
 #define	LEVEL_FAULTY		(-5)