From: Miklos Szeredi <mszeredi@redhat.com>
Date: Mon, 31 Oct 2016 13:42:14 +0000 (+0100)
Subject: ovl: fsync after copy-up
X-Git-Tag: v4.9-rc4~14^2
X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=641089c1549d8d3df0b047b5de7e9a111362cdce;p=linux.git

ovl: fsync after copy-up

Make sure the copied up file hits the disk before renaming to the final
destination.  If this is not done then the copy-up may corrupt the data in
the file in case of a crash.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Cc: <stable@vger.kernel.org>
---

diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c
index aeb60f791418..36795eed40b0 100644
--- a/fs/overlayfs/copy_up.c
+++ b/fs/overlayfs/copy_up.c
@@ -178,6 +178,8 @@ static int ovl_copy_up_data(struct path *old, struct path *new, loff_t len)
 		len -= bytes;
 	}
 
+	if (!error)
+		error = vfs_fsync(new_file, 0);
 	fput(new_file);
 out_fput:
 	fput(old_file);