Merge pull request #903 from restic/fix-hardlinks

Add new field DeviceID and tests

src/restic/node.go

@@ -37,11 +37,12 @@ type Node struct {
 	User               string              `json:"user,omitempty"`
 	Group              string              `json:"group,omitempty"`
 	Inode              uint64              `json:"inode,omitempty"`
+	DeviceID           uint64              `json:"device_id,omitempty"` // device id of the file, stat.st_dev
 	Size               uint64              `json:"size,omitempty"`
 	Links              uint64              `json:"links,omitempty"`
 	LinkTarget         string              `json:"linktarget,omitempty"`
 	ExtendedAttributes []ExtendedAttribute `json:"extended_attributes,omitempty"`
-	Device             uint64              `json:"device,omitempty"`
+	Device             uint64              `json:"device,omitempty"` // in case of Type == "dev", stat.st_rdev
 	Content            IDs                 `json:"content"`
 	Subtree            *ID                 `json:"subtree,omitempty"`
 
@@ -228,11 +229,11 @@ func (node Node) createDirAt(path string) error {
 }
 
 func (node Node) createFileAt(path string, repo Repository, idx *HardlinkIndex) error {
-	if node.Links > 1 && idx.Has(node.Inode, node.Device) {
+	if node.Links > 1 && idx.Has(node.Inode, node.DeviceID) {
 		if err := fs.Remove(path); !os.IsNotExist(err) {
 			return errors.Wrap(err, "RemoveCreateHardlink")
 		}
-		err := fs.Link(idx.GetFilename(node.Inode, node.Device), path)
+		err := fs.Link(idx.GetFilename(node.Inode, node.DeviceID), path)
 		if err != nil {
 			return errors.Wrap(err, "CreateHardlink")
 		}
@@ -271,7 +272,7 @@ func (node Node) createFileAt(path string, repo Repository, idx *HardlinkIndex)
 	}
 
 	if node.Links > 1 {
-		idx.Add(node.Inode, node.Device, path)
+		idx.Add(node.Inode, node.DeviceID, path)
 	}
 
 	return nil
@@ -376,6 +377,9 @@ func (node Node) Equals(other Node) bool {
 	if node.Inode != other.Inode {
 		return false
 	}
+	if node.DeviceID != other.DeviceID {
+		return false
+	}
 	if node.Size != other.Size {
 		return false
 	}
@@ -568,7 +572,7 @@ func (node *Node) fillExtra(path string, fi os.FileInfo) error {
 	}
 
 	node.Inode = uint64(stat.ino())
-	node.Device = uint64(stat.dev())
+	node.DeviceID = uint64(stat.dev())
 
 	node.fillTimes(stat)
 

src/restic/node_unix_test.go

@@ -0,0 +1,135 @@
+// +build !windows
+
+package restic
+
+import (
+	"os"
+	"runtime"
+	"syscall"
+	"testing"
+	"time"
+)
+
+func stat(t testing.TB, filename string) (fi os.FileInfo, ok bool) {
+	fi, err := os.Lstat(filename)
+	if err != nil && os.IsNotExist(err) {
+		return fi, false
+	}
+
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	return fi, true
+}
+
+func checkFile(t testing.TB, stat *syscall.Stat_t, node *Node) {
+	if uint32(node.Mode.Perm()) != uint32(stat.Mode&0777) {
+		t.Errorf("Mode does not match, want %v, got %v", stat.Mode&0777, node.Mode)
+	}
+
+	if node.Inode != uint64(stat.Ino) {
+		t.Errorf("Inode does not match, want %v, got %v", stat.Ino, node.Inode)
+	}
+
+	if node.DeviceID != uint64(stat.Dev) {
+		t.Errorf("Dev does not match, want %v, got %v", stat.Dev, node.DeviceID)
+	}
+
+	if node.Size != uint64(stat.Size) {
+		t.Errorf("Size does not match, want %v, got %v", stat.Size, node.Size)
+	}
+
+	if node.Links != uint64(stat.Nlink) {
+		t.Errorf("Links does not match, want %v, got %v", stat.Nlink, node.Links)
+	}
+
+	if node.UID != stat.Uid {
+		t.Errorf("UID does not match, want %v, got %v", stat.Uid, node.UID)
+	}
+
+	if node.GID != stat.Gid {
+		t.Errorf("UID does not match, want %v, got %v", stat.Gid, node.GID)
+	}
+
+	// use the os dependent function to compare the timestamps
+	s, ok := toStatT(stat)
+	if !ok {
+		return
+	}
+
+	mtime := s.mtim()
+	if node.ModTime != time.Unix(mtime.Unix()) {
+		t.Errorf("ModTime does not match, want %v, got %v", time.Unix(mtime.Unix()), node.ModTime)
+	}
+
+	ctime := s.ctim()
+	if node.ChangeTime != time.Unix(ctime.Unix()) {
+		t.Errorf("ChangeTime does not match, want %v, got %v", time.Unix(ctime.Unix()), node.ChangeTime)
+	}
+
+	atime := s.atim()
+	if node.AccessTime != time.Unix(atime.Unix()) {
+		t.Errorf("AccessTime does not match, want %v, got %v", time.Unix(atime.Unix()), node.AccessTime)
+	}
+
+}
+
+func checkDevice(t testing.TB, stat *syscall.Stat_t, node *Node) {
+	if node.Device != uint64(stat.Rdev) {
+		t.Errorf("Rdev does not match, want %v, got %v", stat.Rdev, node.Device)
+	}
+}
+
+func TestNodeFromFileInfo(t *testing.T) {
+	type Test struct {
+		filename string
+		canSkip  bool
+	}
+	var tests = []Test{
+		{"node_test.go", false},
+		{"/dev/sda", true},
+	}
+
+	// on darwin, users are not permitted to list the extended attributes of
+	// /dev/null, therefore skip it.
+	if runtime.GOOS != "darwin" {
+		tests = append(tests, Test{"/dev/null", true})
+	}
+
+	for _, test := range tests {
+		t.Run("", func(t *testing.T) {
+			fi, found := stat(t, test.filename)
+			if !found && test.canSkip {
+				t.Skipf("%v not found in filesystem")
+				return
+			}
+
+			if fi.Sys() == nil {
+				t.Skip("fi.Sys() is nil")
+				return
+			}
+
+			s, ok := fi.Sys().(*syscall.Stat_t)
+			if !ok {
+				t.Skip("fi type is %T, not stat_t", fi.Sys())
+				return
+			}
+
+			node, err := NodeFromFileInfo(test.filename, fi)
+			if err != nil {
+				t.Fatal(err)
+			}
+
+			switch node.Type {
+			case "file":
+				checkFile(t, s, node)
+			case "dev", "chardev":
+				checkFile(t, s, node)
+				checkDevice(t, s, node)
+			default:
+				t.Fatalf("invalid node type %q", node.Type)
+			}
+		})
+	}
+}