[PATCH 4.14 016/178] ovl: update ctx->pos on impure dir iteration

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Amir Goldstein <amir73il@xxxxxxxxx>

commit b02a16e6413a2f782e542ef60bad9ff6bf212f8a upstream.

This fixes a regression with readdir of impure dir in overlayfs
that is shared to VM via 9p fs.

Reported-by: Miguel Bernal Marin <miguel.bernal.marin@xxxxxxxxxxxxxxx>
Fixes: 4edb83bb1041 ("ovl: constant d_ino for non-merge dirs")
Signed-off-by: Amir Goldstein <amir73il@xxxxxxxxx>
Tested-by: Miguel Bernal Marin <miguel.bernal.marin@xxxxxxxxxxxxxxx>
Signed-off-by: Miklos Szeredi <mszeredi@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 fs/overlayfs/readdir.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

--- a/fs/overlayfs/readdir.c
+++ b/fs/overlayfs/readdir.c
@@ -645,7 +645,10 @@ static int ovl_iterate_real(struct file
 			return PTR_ERR(rdt.cache);
 	}
 
-	return iterate_dir(od->realfile, &rdt.ctx);
+	err = iterate_dir(od->realfile, &rdt.ctx);
+	ctx->pos = rdt.ctx.pos;
+
+	return err;
 }