87 lines
1.4 KiB
Go
87 lines
1.4 KiB
Go
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
|
|
}
|