Add vendoring to containerd master

Initial vendor list validated with empty $GOPATH
and only master checked out; followed by `make`
and verified that all binaries build properly.
Updates require github.com/LK4D4/vndr tool.

Signed-off-by: Phil Estes <estesp@linux.vnet.ibm.com>

vendor/github.com/stevvooe/go-btrfs/helpers.go

@@ -0,0 +1,86 @@
+package btrfs
+
+/*
+#include <stddef.h>
+#include <btrfs/ioctl.h>
+#include <btrfs/ctree.h>
+*/
+import "C"
+
+import (
+	"bufio"
+	"bytes"
+	"fmt"
+	"os"
+	"strings"
+	"unsafe"
+
+	"github.com/pkg/errors"
+)
+
+func subvolID(fd uintptr) (uint64, error) {
+	var args C.struct_btrfs_ioctl_ino_lookup_args
+	args.objectid = C.BTRFS_FIRST_FREE_OBJECTID
+
+	if err := ioctl(fd, C.BTRFS_IOC_INO_LOOKUP, uintptr(unsafe.Pointer(&args))); err != nil {
+		return 0, err
+	}
+
+	return uint64(args.treeid), nil
+}
+
+var (
+	zeroArray = [16]byte{}
+	zeros     = zeroArray[:]
+)
+
+func uuidString(uuid *[C.BTRFS_UUID_SIZE]C.u8) string {
+	b := (*[1<<31 - 1]byte)(unsafe.Pointer(uuid))[:C.BTRFS_UUID_SIZE]
+
+	if bytes.Equal(b, zeros) {
+		return ""
+	}
+
+	return fmt.Sprintf("%x-%x-%x-%x-%x", b[:4], b[4:4+2], b[6:6+2], b[8:8+2], b[10:16])
+}
+
+func findMountPoint(path string) (string, error) {
+	fp, err := os.Open("/proc/self/mounts")
+	if err != nil {
+		return "", err
+	}
+	defer fp.Close()
+
+	const (
+		deviceIdx = 0
+		pathIdx   = 1
+		typeIdx   = 2
+		options   = 3
+	)
+
+	var (
+		mount   string
+		scanner = bufio.NewScanner(fp)
+	)
+
+	for scanner.Scan() {
+		fields := strings.Fields(scanner.Text())
+		if fields[typeIdx] != "btrfs" {
+			continue // skip non-btrfs
+		}
+
+		if strings.HasPrefix(path, fields[pathIdx]) {
+			mount = fields[pathIdx]
+		}
+	}
+
+	if scanner.Err() != nil {
+		return "", scanner.Err()
+	}
+
+	if mount == "" {
+		return "", errors.Errorf("mount point of %v not found", path)
+	}
+
+	return mount, nil
+}