vendor: add buildkit

Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>

vendor/github.com/tonistiigi/fsutil/stat_unix.go

@@ -0,0 +1,71 @@
+// +build !windows
+
+package fsutil
+
+import (
+	"os"
+	"syscall"
+
+	"github.com/containerd/continuity/sysx"
+	"github.com/pkg/errors"
+	"github.com/tonistiigi/fsutil/types"
+)
+
+func loadXattr(origpath string, stat *types.Stat) error {
+	xattrs, err := sysx.LListxattr(origpath)
+	if err != nil {
+		if errors.Cause(err) == syscall.ENOTSUP {
+			return nil
+		}
+		return errors.Wrapf(err, "failed to xattr %s", origpath)
+	}
+	if len(xattrs) > 0 {
+		m := make(map[string][]byte)
+		for _, key := range xattrs {
+			v, err := sysx.LGetxattr(origpath, key)
+			if err == nil {
+				m[key] = v
+			}
+		}
+		stat.Xattrs = m
+	}
+	return nil
+}
+
+func setUnixOpt(fi os.FileInfo, stat *types.Stat, path string, seenFiles map[uint64]string) {
+	s := fi.Sys().(*syscall.Stat_t)
+
+	stat.Uid = s.Uid
+	stat.Gid = s.Gid
+
+	if !fi.IsDir() {
+		if s.Mode&syscall.S_IFBLK != 0 ||
+			s.Mode&syscall.S_IFCHR != 0 {
+			stat.Devmajor = int64(major(uint64(s.Rdev)))
+			stat.Devminor = int64(minor(uint64(s.Rdev)))
+		}
+
+		ino := s.Ino
+		linked := false
+		if seenFiles != nil {
+			if s.Nlink > 1 {
+				if oldpath, ok := seenFiles[ino]; ok {
+					stat.Linkname = oldpath
+					stat.Size_ = 0
+					linked = true
+				}
+			}
+			if !linked {
+				seenFiles[ino] = path
+			}
+		}
+	}
+}
+
+func major(device uint64) uint64 {
+	return (device >> 8) & 0xfff
+}
+
+func minor(device uint64) uint64 {
+	return (device & 0xff) | ((device >> 12) & 0xfff00)
+}