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moby--moby/daemon/graphdriver/devmapper/mount.go
Kir Kolyshkin 0450f61cb9 devmapper.Mounted: remove
It looks like no one uses this function.

Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
2018-02-27 19:13:46 -08:00

66 lines
1.2 KiB
Go

// +build linux
package devmapper // import "github.com/docker/docker/daemon/graphdriver/devmapper"
import (
"bytes"
"fmt"
"os"
)
type probeData struct {
fsName string
magic string
offset uint64
}
// ProbeFsType returns the filesystem name for the given device id.
func ProbeFsType(device string) (string, error) {
probes := []probeData{
{"btrfs", "_BHRfS_M", 0x10040},
{"ext4", "\123\357", 0x438},
{"xfs", "XFSB", 0},
}
maxLen := uint64(0)
for _, p := range probes {
l := p.offset + uint64(len(p.magic))
if l > maxLen {
maxLen = l
}
}
file, err := os.Open(device)
if err != nil {
return "", err
}
defer file.Close()
buffer := make([]byte, maxLen)
l, err := file.Read(buffer)
if err != nil {
return "", err
}
if uint64(l) != maxLen {
return "", fmt.Errorf("devmapper: unable to detect filesystem type of %s, short read", device)
}
for _, p := range probes {
if bytes.Equal([]byte(p.magic), buffer[p.offset:p.offset+uint64(len(p.magic))]) {
return p.fsName, nil
}
}
return "", fmt.Errorf("devmapper: Unknown filesystem type on %s", device)
}
func joinMountOptions(a, b string) string {
if a == "" {
return b
}
if b == "" {
return a
}
return a + "," + b
}