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package main
import (
"fmt"
"os"
"reflect"
"strings"
"github.com/datawire/dlib/derror"
"lukeshu.com/btrfs-tools/pkg/btrfs"
"lukeshu.com/btrfs-tools/pkg/btrfs/btrfsitem"
"lukeshu.com/btrfs-tools/pkg/btrfs/btrfsvol"
"lukeshu.com/btrfs-tools/pkg/btrfsmisc"
"lukeshu.com/btrfs-tools/pkg/util"
)
func main() {
if err := Main(os.Args[1:]...); err != nil {
fmt.Fprintf(os.Stderr, "%v: error: %v\n", os.Args[0], err)
os.Exit(1)
}
}
func Main(imgfilenames ...string) (err error) {
maybeSetErr := func(_err error) {
if _err != nil && err == nil {
err = _err
}
}
fs, err := btrfsmisc.Open(os.O_RDONLY, imgfilenames...)
if err != nil {
return err
}
defer func() {
maybeSetErr(fs.Close())
}()
sb, err := fs.Superblock()
if err != nil {
return err
}
fsTreeRoot, err := fs.TreeLookup(sb.Data.RootTree, btrfs.Key{
ObjectID: btrfs.FS_TREE_OBJECTID,
ItemType: btrfsitem.ROOT_ITEM_KEY,
Offset: 0,
})
if err != nil {
return fmt.Errorf("look up FS_TREE: %w", err)
}
fsTreeRootBody := fsTreeRoot.Body.(btrfsitem.Root)
fsTree := fsTreeRootBody.ByteNr
printDir(fs, fsTree, "", "", "/", fsTreeRootBody.RootDirID)
return nil
}
const (
tS = " "
tl = "│ "
tT = "├── "
tL = "└── "
)
func printDir(fs *btrfs.FS, fsTree btrfsvol.LogicalAddr, prefix0, prefix1, dirName string, dirInode btrfs.ObjID) {
var errs derror.MultiError
items, err := fs.TreeSearchAll(fsTree, func(key btrfs.Key) int {
return util.CmpUint(dirInode, key.ObjectID)
})
if err != nil {
errs = append(errs, fmt.Errorf("read dir: %w", err))
}
var dirInodeDat btrfsitem.Inode
var dirInodeDatOK bool
membersByIndex := make(map[uint64]btrfsitem.DirEntry)
membersByNameHash := make(map[uint64]btrfsitem.DirEntry)
for _, item := range items {
switch item.Head.Key.ItemType {
case btrfsitem.INODE_ITEM_KEY:
if dirInodeDatOK {
errs = append(errs, fmt.Errorf("read dir: multiple inodes"))
continue
}
dirInodeDat = item.Body.(btrfsitem.Inode)
dirInodeDatOK = true
case btrfsitem.INODE_REF_KEY:
// TODO
case btrfsitem.DIR_ITEM_KEY:
body := item.Body.(btrfsitem.DirEntries)
if len(body) != 1 {
errs = append(errs, fmt.Errorf("read dir: multiple direntries in single dir_item?"))
continue
}
for _, entry := range body {
namehash := btrfsitem.NameHash(entry.Name)
if namehash != item.Head.Key.Offset {
errs = append(errs, fmt.Errorf("read dir: direntry crc32c mismatch: key=%#x crc32c(%q)=%#x",
item.Head.Key.Offset, entry.Name, namehash))
continue
}
if other, exists := membersByNameHash[namehash]; exists {
errs = append(errs, fmt.Errorf("read dir: multiple instances of direntry crc32c(%q|%q)=%#x",
other.Name, entry.Name, namehash))
continue
}
membersByNameHash[btrfsitem.NameHash(entry.Name)] = entry
}
case btrfsitem.DIR_INDEX_KEY:
for i, entry := range item.Body.(btrfsitem.DirEntries) {
index := item.Head.Key.Offset + uint64(i)
if _, exists := membersByIndex[index]; exists {
errs = append(errs, fmt.Errorf("read dir: multiple instances of direntry index %v", index))
continue
}
membersByIndex[index] = entry
}
//case btrfsitem.XATTR_ITEM_KEY:
default:
panic(fmt.Errorf("TODO: handle item type %v", item.Head.Key.ItemType))
}
}
fmt.Printf("%s%q\t[ino=%d\t",
prefix0, dirName, dirInode)
if dirInodeDatOK {
fmt.Printf("uid=%d\tgid=%d\tsize=%d]\n",
dirInodeDat.UID, dirInodeDat.GID, dirInodeDat.Size)
} else {
fmt.Printf("error=read dir: no inode data\n")
}
for i, index := range util.SortedMapKeys(membersByIndex) {
entry := membersByIndex[index]
namehash := btrfsitem.NameHash(entry.Name)
if other, ok := membersByNameHash[namehash]; ok {
if !reflect.DeepEqual(entry, other) {
errs = append(errs, fmt.Errorf("read dir: index=%d disagrees with crc32c(%q)=%#x",
index, entry.Name, namehash))
}
delete(membersByNameHash, namehash)
} else {
errs = append(errs, fmt.Errorf("read dir: no DIR_ITEM crc32c(%q)=%#x for DIR_INDEX index=%d",
entry.Name, namehash, index))
}
p0, p1 := tT, tl
if (i == len(membersByIndex)-1) && (len(membersByNameHash) == 0) && (len(errs) == 0) {
p0, p1 = tL, tS
}
printDirEntry(fs, fsTree, prefix1+p0, prefix1+p1, entry)
}
for _, namehash := range util.SortedMapKeys(membersByNameHash) {
entry := membersByNameHash[namehash]
errs = append(errs, fmt.Errorf("read dir: no DIR_INDEX for DIR_ITEM crc32c(%q)=%#x",
entry.Name, namehash))
printDirEntry(fs, fsTree, prefix1+tT, prefix1+tl, entry)
}
for i, err := range errs {
p0, p1 := tT, tl
if i == len(errs)-1 {
p0, p1 = tL, tS
}
fmt.Printf("%s%s%s\n", prefix1+p0, prefix1+p1, strings.ReplaceAll(err.Error(), "\n", prefix1+tS+"\n"))
}
}
func printDirEntry(fs *btrfs.FS, fsTree btrfsvol.LogicalAddr, prefix0, prefix1 string, entry btrfsitem.DirEntry) {
if len(entry.Data) != 0 {
fmt.Printf("%s%q: error: TODO: I don't know how to handle dirent.data\n",
prefix0, entry.Name)
return
}
switch entry.Type {
case btrfsitem.FT_DIR:
printDir(fs, fsTree, prefix0, prefix1, string(entry.Name), entry.Location.ObjectID)
default:
fmt.Printf("%s%q\t[location=%v type=%v]\n", prefix0, entry.Name, entry.Location, entry.Type)
}
}
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