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, 1 insertions, 1 deletions

diff --git a/Grow.c b/Grow.c
index b24e958..fc007d6 100644
--- a/Grow.c
+++ b/Grow.c
@@ -69,7 +69,7 @@ int Grow_Add_device(char *devname, int fd, char *newdev)
 		return 1;
 	}
 
-	nfd = open(newdev, O_RDWR|O_EXCL);
+	nfd = open(newdev, O_RDWR|O_EXCL|O_DIRECT);
 	if (nfd < 0) {
 		fprintf(stderr, Name ": cannot open %s\n", newdev);
 		return 1;