ovl: pass ofs to creation operations

[ Upstream commit 576bb263 ]

Pass down struct ovl_fs to all creation helpers so we can ultimately
retrieve the relevant upper mount and take the mount's idmapping into
account when creating new filesystem objects. This is needed to support
idmapped base layers with overlay.

Cc: <linux-unionfs@vger.kernel.org>
Tested-by: Giuseppe Scrivano <gscrivan@redhat.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Stable-dep-of: c84e125f ("ovl: fix UAF in ovl_dentry_update_reval by moving dput() in ovl_link_up")
Signed-off-by: Sasha Levin <sashal@kernel.org>