rewrite resize

Signed-off-by: Vasiliy Tolstov <v.tolstov@selfip.ru>

system/filesystem_linux.go

@@ -17,13 +17,17 @@ package system
 import (
 	"bufio"
 	"bytes"
+	"errors"
 	"fmt"
 	"io"
+	"io/ioutil"
 	"log"
 	"os"
 	"os/exec"
 	"path/filepath"
+	"strconv"
 	"strings"
+	"syscall"
 	"unicode"
 
 	"github.com/vtolstov/go-ioctl"
@@ -89,29 +93,38 @@ func ResizeRootFS() error {
 	var stdout io.ReadCloser
 	var stdin bytes.Buffer
 
-	mountpoint, err := rootMount()
+	partstart := 0
+	partnum := 0
+	device := "/tmp/resize_dev"
+	partition := "/tmp/resize_part"
+	active := false
+	extended := false
+	parttype := "Linux"
+	devFs, err := findFs()
 	if err != nil {
 		return err
 	}
-
-	partstart := "2048"
-	device, err := rootDevice()
+	devBlk, err := findBlock("/sys/block", devFs)
 	if err != nil {
 		return err
 	}
-
-	mbr := make([]byte, 446)
-
-	f, err := os.OpenFile(device, os.O_RDONLY, os.FileMode(0400))
-	if err != nil {
-		return err
-	}
-	_, err = io.ReadFull(f, mbr)
-	f.Close()
-	if err != nil {
+	if err = syscall.Mknod(device, uint32(os.ModeDevice|syscall.S_IFBLK|0600), devBlk.Int()); err != nil {
 		return err
 	}
+	defer os.Remove(device)
+	//	mbr := make([]byte, 446)
 
+	/*
+		f, err := os.OpenFile(device, os.O_RDONLY, os.FileMode(0400))
+		if err != nil {
+			return err
+		}
+		_, err = io.ReadFull(f, mbr)
+		f.Close()
+		if err != nil {
+			return err
+		}
+	*/
 	cmd := exec.Command("fdisk", "-l", "-u", device)
 	stdout, err = cmd.StdoutPipe()
 	if err != nil {
@@ -131,21 +144,42 @@ func ResizeRootFS() error {
 			break
 		}
 
-		if strings.HasPrefix(line, mountpoint) {
-			ps := strings.Fields(line) // /dev/sda1      *      4096   251658239   125827072  83 Linux
+		if strings.HasPrefix(line, device) {
+			partnum += 1
+			///test3        *  16384 204799  188416  92M  5 Extended
+			ps := strings.Fields(line)
 			if ps[1] == "*" {
-				partstart = ps[2]
+				active = true
+				partstart, _ = strconv.Atoi(ps[2])
+				parttype = ps[6]
+				if ps[7] == "Extended" {
+					extended = true
+				}
 			} else {
-				partstart = ps[1]
+				active = false
+				partstart, _ = strconv.Atoi(ps[1])
+				parttype = ps[5]
+				if ps[6] == "Extended" {
+					extended = true
+				}
 			}
 		}
 	}
 
-	if err = cmd.Wait(); err != nil || partstart == "" {
+	if err = cmd.Wait(); err != nil || partstart == 0 {
 		return fmt.Errorf("failed to open %s via fdisk 4\n", device)
 	}
 
-	stdin.Write([]byte("o\nn\np\n1\n" + partstart + "\n\na\n1\nw\n"))
+	stdin.Write([]byte("d\n" + fmt.Sprintf("%d", partnum) + "\n"))
+	if extended {
+		stdin.Write([]byte("n\nl\n" + fmt.Sprintf("%d", partnum) + "\n" + fmt.Sprintf("%d", partstart) + "\n\n"))
+	} else {
+		stdin.Write([]byte("n\np\n" + fmt.Sprintf("%d", partnum) + "\n\n"))
+	}
+	if active {
+		stdin.Write([]byte("a\n" + fmt.Sprintf("%d", partnum) + "\n"))
+	}
+	stdin.Write([]byte("t\n" + fmt.Sprintf("%d", partnum) + "\n" + parttype + "\nw"))
 	cmd = exec.Command("fdisk", "-u", device)
 	cmd.Stdin = &stdin
 	cmd.Run()
@@ -155,15 +189,16 @@ func ResizeRootFS() error {
 	if err != nil {
 		return err
 	}
-	_, err = w.Write(mbr)
-	if err != nil {
-		return err
-	}
-	err = w.Sync()
-	if err != nil {
-		return err
-	}
-
+	/*
+		_, err = w.Write(mbr)
+		if err != nil {
+			return err
+		}
+		err = w.Sync()
+		if err != nil {
+			return err
+		}
+	*/
 	blkerr := ioctl.BlkRRPart(w.Fd())
 	err = w.Close()
 	if err != nil {
@@ -186,10 +221,71 @@ func ResizeRootFS() error {
 			}
 		}
 	}
-	log.Printf("resize filesystem via %s %s", "resize2fs", mountpoint)
-	err = exec.Command("resize2fs", mountpoint).Run()
+
+	if err = syscall.Mknod(partition, uint32(os.ModeDevice|syscall.S_IFBLK|0600), devFs.Int()); err != nil {
+		return err
+	}
+	defer os.Remove(partition)
+	log.Printf("resize filesystem via %s %s", "resize2fs", partition)
+	buf, err := exec.Command("resize2fs", partition).CombinedOutput()
 	if err != nil {
+		log.Printf("resize2fs %s", buf)
 		return err
 	}
 	return nil
 }
+
+type Dev struct {
+	Major uint64
+	Minor uint64
+}
+
+func (d *Dev) String() string {
+	return fmt.Sprintf("%d:%d", d.Major, d.Minor)
+}
+
+func (d *Dev) Int() int {
+	return int(d.Major*256 + d.Minor)
+}
+
+func findFs() (*Dev, error) {
+	var st syscall.Stat_t
+
+	err := syscall.Stat("/", &st)
+	if err != nil {
+		return nil, err
+	}
+	return &Dev{Major: uint64(st.Dev / 256), Minor: uint64(st.Dev % 256)}, nil
+}
+
+func findBlock(start string, s *Dev) (*Dev, error) {
+	var err error
+	fis, err := ioutil.ReadDir(start)
+	if err != nil {
+		return nil, err
+	}
+	for _, fi := range fis {
+		switch fi.Name() {
+		case "bdi", "subsystem", "device", "trace":
+			continue
+		}
+		if _, err := os.Stat(filepath.Join(start, "dev")); err == nil {
+			if buf, err := ioutil.ReadFile(filepath.Join(start, "dev")); err == nil {
+				dev := strings.TrimSpace(string(buf))
+				if s.String() == dev {
+					if buf, err = ioutil.ReadFile(filepath.Join(filepath.Dir(start), "dev")); err == nil {
+						majorminor := strings.Split(strings.TrimSpace(string(buf)), ":")
+						major, _ := strconv.Atoi(majorminor[0])
+						minor, _ := strconv.Atoi(majorminor[1])
+						return &Dev{Major: uint64(major), Minor: uint64(minor)}, nil
+					}
+				}
+			}
+		}
+		devBlk, err := findBlock(filepath.Join(start, fi.Name()), s)
+		if err == nil {
+			return devBlk, err
+		}
+	}
+	return nil, errors.New("failed to find dev")
+}