Avoid using BLKFLSBUF.

Now that we use O_DIRECT for all device IO, BLKFLSBUF is not needed to
ensure we get current data, and it can impose a cost if any flush-out
is needed.  So remove it.

To be safe, add O_DIRECT to one place where it isn't currently used:
when reading a bitmap.

Signed-off-by: NeilBrown <neilb@suse.de>

1 files changed, 0 insertions, 2 deletions

diff --git a/super0.c b/super0.c
index ecb6b382..d54a5d7f 100644
--- a/super0.c
+++ b/super0.c
@@ -870,8 +870,6 @@ static int load_super0(struct supertype *st, int fd, char *devname)
 
 	offset *= 512;
 
-	ioctl(fd, BLKFLSBUF, 0); /* make sure we read current data */
-
 	if (lseek64(fd, offset, 0)< 0LL) {
 		if (devname)
 			pr_err("Cannot seek to superblock on %s: %s\n",