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package main
import (
"fmt"
"strings"
"os"
"lukeshu.com/btrfs-tools/pkg/btrfs"
)
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)
}
}
const version = "5.17"
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,
},
},
}
superblock, err := fs.Superblock()
if err != nil {
return err
}
fmt.Printf("btrfs-progs v%s \n", version)
if superblock.Data.RootTree != 0 && false { // XXX
fmt.Printf("root tree\n")
printTree(fs, superblock.Data.RootTree)
}
if superblock.Data.ChunkTree != 0 {
fmt.Printf("chunk tree\n")
printTree(fs, superblock.Data.ChunkTree)
}
if superblock.Data.LogTree != 0 {
fmt.Printf("log root tree\n")
printTree(fs, superblock.Data.LogTree)
}
if superblock.Data.BlockGroupRoot != 0 {
fmt.Printf("block group tree\n")
printTree(fs, superblock.Data.BlockGroupRoot)
}
return nil
}
// printTree mimics btrfs-progs kernel-shared/print-tree.c:btrfs_print_tree() and kernel-shared/print-tree.c:btrfs_print_leaf()
func printTree(fs *btrfs.FS, root btrfs.LogicalAddr) {
node, err := fs.ReadNode(root)
if err != nil {
fmt.Printf("error: %v\n", err)
return
}
printHeaderInfo(node)
switch node := node.(type) {
case *btrfs.InternalNode:
// TODO
case *btrfs.LeafNode:
for i, item := range node.Body {
fmt.Printf("\titem %d %s itemoff %d itemsize %d\n",
i,
fmtKey(item.Data.Key),
item.Data.DataOffset,
item.Data.DataSize)
}
}
}
// printHeaderInfo mimics btrfs-progs kernel-shared/print-tree.c:print_header_info()
func printHeaderInfo(node btrfs.Node) {
var typename string
switch node := node.(type) {
case *btrfs.InternalNode:
typename = "node"
fmt.Printf("node %d level %d items %d free space %d",
node.Header.Addr,
node.Header.Data.Level,
node.Header.Data.NumItems,
node.Header.Data.MaxItems-node.Header.Data.NumItems)
case *btrfs.LeafNode:
typename = "leaf"
fmt.Printf("leaf %d items %d free space %d",
node.Header.Addr,
node.Header.Data.NumItems,
node.FreeSpace())
}
fmt.Printf(" generation %d owner %v\n",
node.GetNodeHeader().Data.Generation,
node.GetNodeHeader().Data.Owner)
fmt.Printf("%s %d flags %s backref revision %d\n",
typename,
node.GetNodeHeader().Addr,
node.GetNodeHeader().Data.Flags,
node.GetNodeHeader().Data.BackrefRev)
}
// mimics print-tree.c:btrfs_print_key()
func fmtKey(key btrfs.Key) string {
var out strings.Builder
fmt.Fprintf(&out, "key (%s %v", key.ObjectID.Format(key.ItemType), key.ItemType)
switch key.ItemType {
case btrfs.BTRFS_QGROUP_RELATION_KEY, btrfs.BTRFS_QGROUP_INFO_KEY, btrfs.BTRFS_QGROUP_LIMIT_KEY:
panic("not implemented")
case btrfs.BTRFS_UUID_KEY_SUBVOL, btrfs.BTRFS_UUID_KEY_RECEIVED_SUBVOL:
fmt.Fprintf(&out, " 0x%016x)", key.Offset)
case btrfs.BTRFS_ROOT_ITEM_KEY:
fmt.Fprintf(&out, " %v)", btrfs.ObjID(key.Offset))
default:
if key.Offset == btrfs.MaxUint64pp-1 {
fmt.Fprintf(&out, " -1)")
} else {
fmt.Fprintf(&out, " %d)", key.Offset)
}
}
return out.String()
}
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