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
|
package main
import (
"fmt"
"os"
"sort"
"lukeshu.com/btrfs-tools/pkg/btrfs"
"lukeshu.com/btrfs-tools/pkg/btrfs/btrfsitem"
"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, "%s: error: %v\n", os.Args[0], err)
os.Exit(1)
}
}
func Main(imgfilename string) (err error) {
maybeSetErr := func(_err error) {
if _err != nil && err == nil {
err = _err
}
}
fh, err := os.Open(imgfilename)
if err != nil {
return err
}
defer func() {
maybeSetErr(fh.Close())
}()
fs := &btrfs.FS{
Devices: []*btrfs.Device{
{
File: fh,
},
},
}
fmt.Printf("\nPass 0: superblocks...\n") ///////////////////////////////////////////////////
superblock, err := fs.Superblock()
if err != nil {
return fmt.Errorf("superblock: %w", err)
}
fmt.Printf("\nPass 1: chunk mappings...\n") ////////////////////////////////////////////////
fmt.Printf("Pass 1: ... initializing chunk mappings\n")
if err := fs.Init(); err != nil {
fmt.Printf("Pass 1: ... init chunk tree: error: %v\n", err)
}
fmt.Printf("Pass 1: ... walking chunk tree\n")
visitedChunkNodes := make(map[btrfs.LogicalAddr]struct{})
if err := fs.WalkTree(superblock.Data.ChunkTree, btrfs.WalkTreeHandler{
Node: func(node *util.Ref[btrfs.LogicalAddr, btrfs.Node], err error) error {
if err != nil {
fmt.Printf("Pass 1: ... walk chunk tree: error: %v\n", err)
}
if node != nil {
visitedChunkNodes[node.Addr] = struct{}{}
}
return err
},
}); err != nil {
fmt.Printf("Pass 1: ... walk chunk tree: error: %v\n", err)
}
for _, dev := range fs.Devices {
fmt.Printf("Pass 1: ... dev[%q] scanning for nodes\n", dev.Name())
foundNodes := make(map[btrfs.LogicalAddr][]btrfs.PhysicalAddr)
var lostAndFoundChunks []btrfs.SysChunk
if err := btrfsmisc.ScanForNodes(dev, superblock.Data, func(nodeRef *util.Ref[btrfs.PhysicalAddr, btrfs.Node], err error) {
if err != nil {
fmt.Printf("Pass 1: ... dev[%q] error: %v\n", dev.Name(), err)
return
}
foundNodes[nodeRef.Data.Head.Addr] = append(foundNodes[nodeRef.Data.Head.Addr], nodeRef.Addr)
_, alreadyVisited := visitedChunkNodes[nodeRef.Data.Head.Addr]
if nodeRef.Data.Head.Owner == btrfs.CHUNK_TREE_OBJECTID && !alreadyVisited {
for i, item := range nodeRef.Data.BodyLeaf {
if item.Head.Key.ItemType != btrfsitem.CHUNK_ITEM_KEY {
continue
}
chunk, ok := item.Body.(btrfsitem.Chunk)
if !ok {
fmt.Printf("Pass 1: ... dev[%q] node@%d: item %d: error: type is CHUNK_ITEM_KEY, but struct is %T\n",
dev.Name(), nodeRef.Addr, i, item.Body)
continue
}
fmt.Printf("Pass 1: ... dev[%q] node@%d: item %d: found chunk\n",
dev.Name(), nodeRef.Addr, i)
lostAndFoundChunks = append(lostAndFoundChunks, btrfs.SysChunk{
Key: item.Head.Key,
Chunk: chunk,
})
}
}
}); err != nil {
return err
}
fmt.Printf("Pass 1: ... dev[%q] re-inserting lost+found chunks\n", dev.Name())
if len(lostAndFoundChunks) > 0 {
panic("TODO")
}
fmt.Printf("Pass 1: ... dev[%q] re-constructing stripes for lost+found nodes\n", dev.Name())
lostAndFoundNodes := make(map[btrfs.PhysicalAddr]btrfs.LogicalAddr)
for laddr, readPaddrs := range foundNodes {
resolvedPaddrs, _ := fs.Resolve(laddr)
for _, readPaddr := range readPaddrs {
if _, ok := resolvedPaddrs[btrfs.QualifiedPhysicalAddr{
Dev: superblock.Data.DevItem.DevUUID,
Addr: readPaddr,
}]; !ok {
lostAndFoundNodes[readPaddr] = laddr
}
}
}
sortedPaddrs := make([]btrfs.PhysicalAddr, 0, len(lostAndFoundNodes))
for paddr := range lostAndFoundNodes {
sortedPaddrs = append(sortedPaddrs, paddr)
}
sort.Slice(sortedPaddrs, func(i, j int) bool {
return sortedPaddrs[i] < sortedPaddrs[j]
})
type stripe struct {
PAddr btrfs.PhysicalAddr
LAddr btrfs.LogicalAddr
Size uint64
}
var stripes []stripe
for _, paddr := range sortedPaddrs {
var lastStripe *stripe
if len(stripes) > 0 {
lastStripe = &stripes[len(stripes)-1]
}
if lastStripe != nil && (lastStripe.PAddr+btrfs.PhysicalAddr(lastStripe.Size)) == paddr {
lastStripe.Size += uint64(superblock.Data.NodeSize)
} else {
stripes = append(stripes, stripe{
PAddr: paddr,
LAddr: lostAndFoundNodes[paddr],
Size: uint64(superblock.Data.NodeSize),
})
}
}
fmt.Printf("Pass 1: ... dev[%q] reconstructed stripes: %#v\n", dev.Name(), stripes)
}
fmt.Printf("\nPass 2: ?????????????????????????\n") ////////////////////////////////////////
/*
fmt.Printf("node@%d: physical_addr=0x%0X logical_addr=0x%0X generation=%d owner=%v level=%d\n",
nodeRef.Addr,
nodeRef.Addr, nodeRef.Data.Head.Addr,
nodeRef.Data.Head.Generation, nodeRef.Data.Head.Owner, nodeRef.Data.Head.Level)
srcPaddr := btrfs.QualifiedPhysicalAddr{
Dev: superblock.Data.DevItem.DevUUID,
Addr: nodeRef.Addr,
}
resPaddrs, _ := fs.Resolve(nodeRef.Data.Head.Addr)
if len(resPaddrs) == 0 {
fmt.Printf("node@%d: logical_addr=0x%0X is not mapped\n",
nodeRef.Addr, nodeRef.Data.Head.Addr)
} else if _, ok := resPaddrs[srcPaddr]; !ok {
fmt.Printf("node@%d: logical_addr=0x%0X maps to %v, not %v\n",
nodeRef.Addr, nodeRef.Data.Head.Addr, resPaddrs, srcPaddr)
}
*/
return nil
}
|