libpod: Move part of (*Container).stat to container_stat_linux.go

The logic that treats running containers differently from stopped
containers is not needed on FreeBSD where the container mounts live in
a global mount namespace.

[NO NEW TESTS NEEDED]

Signed-off-by: Doug Rabson <dfr@rabson.org>

libpod/container_stat_linux.go

@@ -0,0 +1,38 @@
+package libpod
+
+import (
+	"github.com/containers/buildah/copier"
+	"github.com/containers/podman/v4/libpod/define"
+)
+
+// statInsideMount stats the specified path *inside* the container's mount and PID
+// namespace.  It returns the file info along with the resolved root ("/") and
+// the resolved path (relative to the root).
+func (c *Container) statInsideMount(containerPath string) (*copier.StatForItem, string, string, error) {
+	resolvedRoot := "/"
+	resolvedPath := c.pathAbs(containerPath)
+	var statInfo *copier.StatForItem
+
+	err := c.joinMountAndExec(
+		func() error {
+			var statErr error
+			statInfo, statErr = secureStat(resolvedRoot, resolvedPath)
+			return statErr
+		},
+	)
+
+	return statInfo, resolvedRoot, resolvedPath, err
+}
+
+// Calls either statOnHost or statInsideMount depending on whether the
+// container is running
+func (c *Container) statInContainer(mountPoint string, containerPath string) (*copier.StatForItem, string, string, error) {
+	if c.state.State == define.ContainerStateRunning {
+		// If the container is running, we need to join it's mount namespace
+		// and stat there.
+		return c.statInsideMount(containerPath)
+	}
+	// If the container is NOT running, we need to resolve the path
+	// on the host.
+	return c.statOnHost(mountPoint, containerPath)
+}