summaryrefslogtreecommitdiff
path: root/cmd/btrfs-ls-files/main.go
blob: 36d14ed2caaf5798e5e90b38812a473dae07f891 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
// Copyright (C) 2022  Luke Shumaker <lukeshu@lukeshu.com>
//
// SPDX-License-Identifier: GPL-2.0-or-later

package main

import (
	"fmt"
	"os"
	"reflect"
	"strings"

	"github.com/datawire/dlib/derror"

	"git.lukeshu.com/btrfs-progs-ng/lib/btrfs"
	"git.lukeshu.com/btrfs-progs-ng/lib/btrfs/btrfsitem"
	"git.lukeshu.com/btrfs-progs-ng/lib/btrfsprogs/btrfsutil"
	"git.lukeshu.com/btrfs-progs-ng/lib/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 := btrfsutil.Open(os.O_RDONLY, imgfilenames...)
	if err != nil {
		return err
	}
	defer func() {
		maybeSetErr(fs.Close())
	}()

	printSubvol(fs, "", "", "/", btrfs.Key{
		ObjectID: btrfs.FS_TREE_OBJECTID,
		ItemType: btrfsitem.ROOT_ITEM_KEY,
		Offset:   0,
	})

	return nil
}

const (
	tS = "    "
	tl = "│   "
	tT = "├── "
	tL = "└── "
)

func printSubvol(fs *btrfs.FS, prefix0, prefix1, name string, key btrfs.Key) {
	root, err := fs.TreeLookup(btrfs.ROOT_TREE_OBJECTID, key)
	if err != nil {
		fmt.Printf("%s%q error: could not look up root %v: %v\n", prefix0, name, key, err)
		return
	}
	rootBody := root.Body.(btrfsitem.Root)

	printDir(fs, root.Head.Key.ObjectID, prefix0, prefix1, name, rootBody.RootDirID)
}

func printDir(fs *btrfs.FS, fsTree btrfs.ObjID, 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 {
				if !reflect.DeepEqual(dirInodeDat, item.Body.(btrfsitem.Inode)) {
					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 {
					if !reflect.DeepEqual(entry, other) {
						if string(entry.Name) == string(other.Name) {
							errs = append(errs, fmt.Errorf("read dir: multiple instances of direntry crc32c(%q)=%#x",
								entry.Name, namehash))
						} else {
							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:
			index := item.Head.Key.Offset
			body := item.Body.(btrfsitem.DirEntries)
			if len(body) != 1 {
				errs = append(errs, fmt.Errorf("read dir: multiple direntries in single DIR_INDEX?"))
				continue
			}
			for _, entry := range body {
				if other, exists := membersByIndex[index]; exists {
					if !reflect.DeepEqual(entry, other) {
						errs = append(errs, fmt.Errorf("read dir: multiple instances of direntry index %v", index))
					}
					continue
				}
				membersByIndex[index] = entry
			}
		//case btrfsitem.XATTR_ITEM_KEY:
		default:
			errs = append(errs, fmt.Errorf("TODO: handle item type %v", item.Head.Key.ItemType))
		}
	}
	fmt.Printf("%s%q\t[ino=%d",
		prefix0, dirName, dirInode)
	if dirInodeDatOK {
		fmt.Printf("\tuid=%d\tgid=%d\tsize=%d]\n",
			dirInodeDat.UID, dirInodeDat.GID, dirInodeDat.Size)
	} else {
		err := fmt.Errorf("read dir: no inode data")
		if len(items) == 0 && len(errs) == 1 {
			err = errs[0]
			errs = nil
		}
		fmt.Printf("]\terror: %v\n", err)
	}
	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("%serror: %s\n", prefix1+p0, strings.ReplaceAll(err.Error(), "\n", prefix1+p1+"       \n"))
	}
}

func printDirEntry(fs *btrfs.FS, fsTree btrfs.ObjID, 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:
		switch entry.Location.ItemType {
		case btrfsitem.INODE_ITEM_KEY:
			printDir(fs, fsTree, prefix0, prefix1, string(entry.Name), entry.Location.ObjectID)
		case btrfsitem.ROOT_ITEM_KEY:
			key := entry.Location
			key.Offset = 0
			printSubvol(fs, prefix0, prefix1, string(entry.Name), key)
		default:
			fmt.Printf("%s%q\t[location=%v type=%v] error: I'm not sure how to print a %v directory\n",
				prefix0, entry.Name, entry.Location, entry.Type, entry.Location.ItemType)
		}
	default:
		fmt.Printf("%s%q\t[location=%v type=%v]\n", prefix0, entry.Name, entry.Location, entry.Type)
	}
}