diff --git a/internal/initwd/copy_dir.go b/internal/copydir/copy_dir.go
similarity index 50%
rename from internal/initwd/copy_dir.go
rename to internal/copydir/copy_dir.go
index 7096ff74f8..1f156430a1 100644
--- a/internal/initwd/copy_dir.go
+++ b/internal/copydir/copy_dir.go
@@ -1,4 +1,4 @@
-package initwd
+package copydir
 
 import (
 	"io"
@@ -7,9 +7,32 @@ import (
 	"strings"
 )
 
-// copyDir copies the src directory contents into dst. Both directories
-// should already exist.
-func copyDir(dst, src string) error {
+// CopyDir recursively copies all of the files within the directory given in
+// src to the directory given in dst.
+//
+// Both directories should already exist. If the destination directory is
+// non-empty then the new files will merge in with the old, overwriting any
+// files that have a relative path in common between source and destination.
+//
+// Recursive copying of directories is inevitably a rather opinionated sort of
+// operation, so this function won't be appropriate for all use-cases. Some
+// of the "opinions" it has are described in the following paragraphs:
+//
+// Symlinks in the source directory are recreated with the same target in the
+// destination directory. If the symlink is to a directory itself, that
+// directory is not recursively visited for further copying.
+//
+// File and directory modes are not preserved exactly, but the executable
+// flag is preserved for files on operating systems where it is significant.
+//
+// Any "dot files" it encounters along the way are skipped, even on platforms
+// that do not normally ascribe special meaning to files with names starting
+// with dots.
+//
+// Callers may rely on the above details and other undocumented details of
+// this function, so if you intend to change it be sure to review the callers
+// first and make sure they are compatible with the change you intend to make.
+func CopyDir(dst, src string) error {
 	src, err := filepath.EvalSymlinks(src)
 	if err != nil {
 		return err
@@ -38,7 +61,7 @@ func copyDir(dst, src string) error {
 		dstPath := filepath.Join(dst, path[len(src):])
 
 		// we don't want to try and copy the same file over itself.
-		if eq, err := sameFile(path, dstPath); eq {
+		if eq, err := SameFile(path, dstPath); eq {
 			return nil
 		} else if err != nil {
 			return err
@@ -94,14 +117,16 @@ func copyDir(dst, src string) error {
 	return filepath.Walk(src, walkFn)
 }
 
-// sameFile tried to determine if to paths are the same file.
-// If the paths don't match, we lookup the inode on supported systems.
-func sameFile(a, b string) (bool, error) {
+// SameFile returns true if the two given paths refer to the same physical
+// file on disk, using the unique file identifiers from the underlying
+// operating system. For example, on Unix systems this checks whether the
+// two files are on the same device and have the same inode.
+func SameFile(a, b string) (bool, error) {
 	if a == b {
 		return true, nil
 	}
 
-	aIno, err := inode(a)
+	aInfo, err := os.Lstat(a)
 	if err != nil {
 		if os.IsNotExist(err) {
 			return false, nil
@@ -109,7 +134,7 @@ func sameFile(a, b string) (bool, error) {
 		return false, err
 	}
 
-	bIno, err := inode(b)
+	bInfo, err := os.Lstat(b)
 	if err != nil {
 		if os.IsNotExist(err) {
 			return false, nil
@@ -117,9 +142,5 @@ func sameFile(a, b string) (bool, error) {
 		return false, err
 	}
 
-	if aIno > 0 && aIno == bIno {
-		return true, nil
-	}
-
-	return false, nil
+	return os.SameFile(aInfo, bInfo), nil
 }
diff --git a/internal/initwd/copy_dir_test.go b/internal/copydir/copy_dir_test.go
similarity index 96%
rename from internal/initwd/copy_dir_test.go
rename to internal/copydir/copy_dir_test.go
index 06e02f824b..41e4332280 100644
--- a/internal/initwd/copy_dir_test.go
+++ b/internal/copydir/copy_dir_test.go
@@ -1,4 +1,4 @@
-package initwd
+package copydir
 
 import (
 	"io/ioutil"
@@ -52,7 +52,7 @@ func TestCopyDir_symlinks(t *testing.T) {
 	targetDir := filepath.Join(tmpdir, "target")
 	os.Mkdir(targetDir, os.ModePerm)
 
-	err = copyDir(targetDir, moduleDir)
+	err = CopyDir(targetDir, moduleDir)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -92,7 +92,7 @@ func TestCopyDir_symlink_file(t *testing.T) {
 	targetDir := filepath.Join(tmpdir, "target")
 	os.Mkdir(targetDir, os.ModePerm)
 
-	err = copyDir(targetDir, moduleDir)
+	err = CopyDir(targetDir, moduleDir)
 	if err != nil {
 		t.Fatal(err)
 	}
diff --git a/internal/initwd/from_module.go b/internal/initwd/from_module.go
index 6b40d08d69..e944cac981 100644
--- a/internal/initwd/from_module.go
+++ b/internal/initwd/from_module.go
@@ -2,7 +2,6 @@ package initwd
 
 import (
 	"fmt"
-	"github.com/hashicorp/terraform/internal/earlyconfig"
 	"io/ioutil"
 	"log"
 	"os"
@@ -10,8 +9,11 @@ import (
 	"sort"
 	"strings"
 
+	"github.com/hashicorp/terraform/internal/earlyconfig"
+
 	version "github.com/hashicorp/go-version"
 	"github.com/hashicorp/terraform-config-inspect/tfconfig"
+	"github.com/hashicorp/terraform/internal/copydir"
 	"github.com/hashicorp/terraform/internal/modsdir"
 	"github.com/hashicorp/terraform/registry"
 	"github.com/hashicorp/terraform/tfdiags"
@@ -172,7 +174,7 @@ func DirFromModule(rootDir, modulesDir, sourceAddr string, reg *registry.Client,
 			// We've found the module the user requested, which we must
 			// now copy into rootDir so it can be used directly.
 			log.Printf("[TRACE] copying new root module from %s to %s", record.Dir, rootDir)
-			err := copyDir(rootDir, record.Dir)
+			err := copydir.CopyDir(rootDir, record.Dir)
 			if err != nil {
 				diags = diags.Append(tfdiags.Sourceless(
 					tfdiags.Error,
@@ -292,7 +294,7 @@ func DirFromModule(rootDir, modulesDir, sourceAddr string, reg *registry.Client,
 		// We copy rather than "rename" here because renaming between directories
 		// can be tricky in edge-cases like network filesystems, etc.
 		log.Printf("[TRACE] copying new module %s from %s to %s", newKey, record.Dir, instPath)
-		err := copyDir(instPath, tempPath)
+		err := copydir.CopyDir(instPath, tempPath)
 		if err != nil {
 			diags = diags.Append(tfdiags.Sourceless(
 				tfdiags.Error,
diff --git a/internal/initwd/getter.go b/internal/initwd/getter.go
index 85574f7ca3..79bb7d7b62 100644
--- a/internal/initwd/getter.go
+++ b/internal/initwd/getter.go
@@ -9,6 +9,7 @@ import (
 
 	cleanhttp "github.com/hashicorp/go-cleanhttp"
 	getter "github.com/hashicorp/go-getter"
+	"github.com/hashicorp/terraform/internal/copydir"
 	"github.com/hashicorp/terraform/registry/regsrc"
 )
 
@@ -112,7 +113,7 @@ func (g reusingGetter) getWithGoGetter(instPath, addr string) (string, error) {
 		if err != nil {
 			return "", fmt.Errorf("failed to create directory %s: %s", instPath, err)
 		}
-		err = copyDir(instPath, prevDir)
+		err = copydir.CopyDir(instPath, prevDir)
 		if err != nil {
 			return "", fmt.Errorf("failed to copy from %s to %s: %s", prevDir, instPath, err)
 		}
diff --git a/internal/initwd/inode.go b/internal/initwd/inode.go
deleted file mode 100644
index 1150b093cc..0000000000
--- a/internal/initwd/inode.go
+++ /dev/null
@@ -1,21 +0,0 @@
-// +build linux darwin openbsd netbsd solaris dragonfly
-
-package initwd
-
-import (
-	"fmt"
-	"os"
-	"syscall"
-)
-
-// lookup the inode of a file on posix systems
-func inode(path string) (uint64, error) {
-	stat, err := os.Stat(path)
-	if err != nil {
-		return 0, err
-	}
-	if st, ok := stat.Sys().(*syscall.Stat_t); ok {
-		return st.Ino, nil
-	}
-	return 0, fmt.Errorf("could not determine file inode")
-}
diff --git a/internal/initwd/inode_freebsd.go b/internal/initwd/inode_freebsd.go
deleted file mode 100644
index 30532f54ac..0000000000
--- a/internal/initwd/inode_freebsd.go
+++ /dev/null
@@ -1,21 +0,0 @@
-// +build freebsd
-
-package initwd
-
-import (
-	"fmt"
-	"os"
-	"syscall"
-)
-
-// lookup the inode of a file on posix systems
-func inode(path string) (uint64, error) {
-	stat, err := os.Stat(path)
-	if err != nil {
-		return 0, err
-	}
-	if st, ok := stat.Sys().(*syscall.Stat_t); ok {
-		return uint64(st.Ino), nil
-	}
-	return 0, fmt.Errorf("could not determine file inode")
-}
diff --git a/internal/initwd/inode_windows.go b/internal/initwd/inode_windows.go
deleted file mode 100644
index 3ed58e4bf9..0000000000
--- a/internal/initwd/inode_windows.go
+++ /dev/null
@@ -1,8 +0,0 @@
-// +build windows
-
-package initwd
-
-// no syscall.Stat_t on windows, return 0 for inodes
-func inode(path string) (uint64, error) {
-	return 0, nil
-}
diff --git a/internal/initwd/module_install_test.go b/internal/initwd/module_install_test.go
index 239014990b..d4d7eb1a78 100644
--- a/internal/initwd/module_install_test.go
+++ b/internal/initwd/module_install_test.go
@@ -15,6 +15,7 @@ import (
 	"github.com/hashicorp/terraform/configs"
 	"github.com/hashicorp/terraform/configs/configload"
 	"github.com/hashicorp/terraform/helper/logging"
+	"github.com/hashicorp/terraform/internal/copydir"
 	"github.com/hashicorp/terraform/registry"
 	"github.com/hashicorp/terraform/tfdiags"
 )
@@ -543,7 +544,7 @@ func tempChdir(t *testing.T, sourceDir string) (string, func()) {
 		return "", nil
 	}
 
-	if err := copyDir(tmpDir, sourceDir); err != nil {
+	if err := copydir.CopyDir(tmpDir, sourceDir); err != nil {
 		t.Fatalf("failed to copy fixture to temporary directory: %s", err)
 		return "", nil
 	}