[PATCH] Btrfs: update last trans if we don't update the inode

[Josef Bacik <jbacik@fusionio.com>]

There is a completely impossible situation to hit where you can preallocate
a file, fsync it, write into the preallocated region, have the transaction
commit twice and then fsync and then immediately lose power and lose all of
the contents of the write.  This patch fixes this just so I feel better
about the situation and because it is lightweight, we just update the
last_trans when we finish an ordered IO and we don't update the inode
itself.  This way we are completely safe and I feel better.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
---
 fs/btrfs/inode.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index d331d96..a391cba 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -1947,6 +1947,8 @@ static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent)
 			btrfs_abort_transaction(trans, root, ret);
 			goto out_unlock;
 		}
+	} else {
+		btrfs_set_inode_last_trans(trans, inode);
 	}
 	ret = 0;
 out_unlock:
-- 
1.7.7.6