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
|
// Copyright (C) 2022-2023 Luke Shumaker <lukeshu@lukeshu.com>
//
// SPDX-License-Identifier: GPL-2.0-or-later
package btrfs
import (
"fmt"
"git.lukeshu.com/btrfs-progs-ng/lib/btrfs/btrfsitem"
"git.lukeshu.com/btrfs-progs-ng/lib/btrfs/btrfsprim"
"git.lukeshu.com/btrfs-progs-ng/lib/btrfs/btrfssum"
"git.lukeshu.com/btrfs-progs-ng/lib/btrfs/btrfstree"
"git.lukeshu.com/btrfs-progs-ng/lib/btrfs/btrfsvol"
"git.lukeshu.com/btrfs-progs-ng/lib/containers"
"git.lukeshu.com/btrfs-progs-ng/lib/diskio"
)
// dat doesn't escape to the heap in .ReadAt(dat, …), but the compiler
// can't figure that out, so we use a Pool for our byte arrays, since
// the compiler won't let us allocate them on the stack.
var blockPool containers.SlicePool[byte]
func ChecksumLogical(fs diskio.File[btrfsvol.LogicalAddr], alg btrfssum.CSumType, laddr btrfsvol.LogicalAddr) (btrfssum.CSum, error) {
dat := blockPool.Get(btrfssum.BlockSize)
defer blockPool.Put(dat)
if _, err := fs.ReadAt(dat, laddr); err != nil {
return btrfssum.CSum{}, err
}
return alg.Sum(dat)
}
func ChecksumPhysical(dev *Device, alg btrfssum.CSumType, paddr btrfsvol.PhysicalAddr) (btrfssum.CSum, error) {
dat := blockPool.Get(btrfssum.BlockSize)
defer blockPool.Put(dat)
if _, err := dev.ReadAt(dat, paddr); err != nil {
return btrfssum.CSum{}, err
}
return alg.Sum(dat)
}
func ChecksumQualifiedPhysical(fs *FS, alg btrfssum.CSumType, paddr btrfsvol.QualifiedPhysicalAddr) (btrfssum.CSum, error) {
dev := fs.LV.PhysicalVolumes()[paddr.Dev]
if dev == nil {
return btrfssum.CSum{}, fmt.Errorf("no such device_id=%v", paddr.Dev)
}
return ChecksumPhysical(dev, alg, paddr.Addr)
}
func LookupCSum(fs btrfstree.TreeOperator, alg btrfssum.CSumType, laddr btrfsvol.LogicalAddr) (btrfssum.SumRun[btrfsvol.LogicalAddr], error) {
item, err := fs.TreeSearch(btrfsprim.CSUM_TREE_OBJECTID, func(key btrfsprim.Key, size uint32) int {
itemBeg := btrfsvol.LogicalAddr(key.Offset)
numSums := int64(size) / int64(alg.Size())
itemEnd := itemBeg + btrfsvol.LogicalAddr(numSums*btrfssum.BlockSize)
switch {
case itemEnd <= laddr:
return 1
case laddr < itemBeg:
return -1
default:
return 0
}
})
if err != nil {
return btrfssum.SumRun[btrfsvol.LogicalAddr]{}, err
}
if item.Key.ItemType != btrfsitem.EXTENT_CSUM_KEY {
return btrfssum.SumRun[btrfsvol.LogicalAddr]{}, fmt.Errorf("item type is %v, not EXTENT_CSUM", item.Key.ItemType)
}
switch body := item.Body.(type) {
case *btrfsitem.ExtentCSum:
return body.SumRun, nil
case *btrfsitem.Error:
return btrfssum.SumRun[btrfsvol.LogicalAddr]{}, body.Err
default:
panic(fmt.Errorf("should not happen: EXTENT_CSUM has unexpected item type: %T", body))
}
}
|
