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Implement new findPartUUID that uses github.com/u-root/u-root/pkg/mount/gpt

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This commit is contained in:
lordwelch 2020-12-09 16:06:05 -08:00
parent d62e976d20
commit 1112d98ca9
3 changed files with 78 additions and 33 deletions
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1
go.mod
View File

@ -7,5 +7,6 @@ replace github.com/cavaliercoder/grab => ./grab
require (
github.com/cavaliercoder/grab v2.0.0+incompatible
github.com/lordwelch/pathvalidate v0.0.0-20201012043703-54efa7ea1308
github.com/u-root/u-root v7.0.0+incompatible
golang.org/x/net v0.0.0-20201209123823-ac852fbbde11
)

3
go.sum
View File

@ -1,5 +1,8 @@
github.com/lordwelch/pathvalidate v0.0.0-20201012043703-54efa7ea1308 h1:CkcsZK6QYg59rc92eqU2h+FRjWltCIiplmEwIB05jfM=
github.com/lordwelch/pathvalidate v0.0.0-20201012043703-54efa7ea1308/go.mod h1:4I4r5Y/LkH+34KACiudU+Q27ooz7xSDyVEuWAVKeJEQ=
github.com/u-root/u-root v1.0.0 h1:3hJy0CG3mXIZtWRE+yrghG/3H0v8L1qEeZBlPr5nS9s=
github.com/u-root/u-root v7.0.0+incompatible h1:u+KSS04pSxJGI5E7WE4Bs9+Zd75QjFv+REkjy/aoAc8=
github.com/u-root/u-root v7.0.0+incompatible/go.mod h1:RYkpo8pTHrNjW08opNd/U6p/RJE7K0D8fXO0d47+3YY=
golang.org/x/net v0.0.0-20201209123823-ac852fbbde11 h1:lwlPPsmjDKK0J6eG6xDWd5XPehI0R024zxjDnw3esPA=
golang.org/x/net v0.0.0-20201209123823-ac852fbbde11/go.mod h1:m0MpNAwzfU5UDzcl9v0D8zg8gWTRqZa9RBIspLL5mdg=
golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=

107
main.go
View File

@ -1,7 +1,6 @@
package main
import (
"encoding/binary"
"errors"
"flag"
"fmt"
@ -10,8 +9,11 @@ import (
"log"
"os"
"path/filepath"
"strconv"
"strings"
"syscall"
"github.com/u-root/u-root/pkg/mount/gpt"
)
var (
@ -37,7 +39,7 @@ func mount() error {
var (
partUUIDb []byte
partUUID string
dev string
dev part
err error
dataStat os.FileInfo
dataDir = filepath.Join(gloaderHome, "data")
@ -71,11 +73,11 @@ func mount() error {
_, err = folder.Readdir(1)
if errors.Is(err, io.EOF) {
fmt.Printf("mount %s %s", partUUID, dataDir)
dev, err = findPartUUID(partUUID)
dev = findPartUUID(partUUID)
if err != nil {
return fmt.Errorf("error mounting datadir: %w", err)
}
err = syscall.Mount(dev, dataDir, "ext4", 0, "")
err = syscall.Mount(dev.Path, dataDir, "ext4", 0, "")
if err != nil {
return fmt.Errorf("error mounting datadir: %w", err)
}
@ -86,11 +88,66 @@ func mount() error {
return fmt.Errorf("error mounting datadir: data dir %s is not a directory", dataDir)
}
func findPartUUID(uuid string) (string, error) {
var dev string
// func findPartUUID(uuid string) (string, error) {
// var dev string
// err := filepath.Walk("/sys/block", func(path string, info os.FileInfo, err error) error {
// if err != nil {
// log.Printf("findPartUUID: %v", err)
// return nil
// }
// if info.Mode()&os.ModeSymlink == 0 {
// return nil
// }
// devname := "/dev/" + filepath.Base(path)
// f, err := os.Open(devname)
// if err != nil {
// log.Printf("findPartUUID: %v", err)
// return nil
// }
// defer f.Close()
// if _, err := f.Seek(440, io.SeekStart); err != nil {
// var se syscall.Errno
// if errors.As(err, &se) && se == syscall.EINVAL {
// // Seek()ing empty loop devices results in EINVAL.
// return nil
// }
// log.Printf("findPartUUID: %v(%T)", err, err.(*os.PathError).Err)
// return nil
// }
// var diskSig struct {
// ID uint32
// Trailer uint16
// }
// if err := binary.Read(f, binary.LittleEndian, &diskSig); err != nil {
// log.Printf("findPartUUID: %v", err)
// return nil
// }
// if fmt.Sprintf("%08x", diskSig.ID) == uuid && diskSig.Trailer == 0 {
// dev = devname
// // TODO: abort early with sentinel error code
// return nil
// }
// return nil
// })
// if err != nil {
// return "", err
// }
// if dev == "" {
// return "", fmt.Errorf("PARTUUID=%s not found", uuid)
// }
// return dev, nil
// }
type part struct {
UUID string
Path string
}
func findPartUUID(UUID string) part {
var dev part
err := filepath.Walk("/sys/block", func(path string, info os.FileInfo, err error) error {
if err != nil {
log.Printf("findPartUUID: %v", err)
log.Printf("listPartUUID: %v", err)
return nil
}
if info.Mode()&os.ModeSymlink == 0 {
@ -99,39 +156,23 @@ func findPartUUID(uuid string) (string, error) {
devname := "/dev/" + filepath.Base(path)
f, err := os.Open(devname)
if err != nil {
log.Printf("findPartUUID: %v", err)
log.Printf("listPartUUID: %v", err)
return nil
}
defer f.Close()
if _, err := f.Seek(440, io.SeekStart); err != nil {
var se syscall.Errno
if errors.As(err, &se) && se == syscall.EINVAL {
// Seek()ing empty loop devices results in EINVAL.
return nil
parttable, _ := gpt.New(f)
if parttable.Primary != nil {
for i, partition := range parttable.Primary.Parts {
if partition.UniqueGUID.String() == UUID {
dev = part{UUID: partition.UniqueGUID.String(), Path: devname + strconv.Itoa(i+1)}
}
}
log.Printf("findPartUUID: %v(%T)", err, err.(*os.PathError).Err)
return nil
}
var diskSig struct {
ID uint32
Trailer uint16
}
if err := binary.Read(f, binary.LittleEndian, &diskSig); err != nil {
log.Printf("findPartUUID: %v", err)
return nil
}
if fmt.Sprintf("%08x", diskSig.ID) == uuid && diskSig.Trailer == 0 {
dev = devname
// TODO: abort early with sentinel error code
return nil
}
return nil
})
if err != nil {
return "", err
return part{}
}
if dev == "" {
return "", fmt.Errorf("PARTUUID=%s not found", uuid)
}
return dev, nil
return dev
}