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// Copyright (C) 2022-2023 Luke Shumaker <lukeshu@lukeshu.com>
//
// SPDX-License-Identifier: GPL-2.0-or-later
package rebuildmappings
import (
"context"
"fmt"
"strings"
"github.com/datawire/dlib/dlog"
"git.lukeshu.com/btrfs-progs-ng/lib/btrfs"
"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/btrfsutil"
"git.lukeshu.com/btrfs-progs-ng/lib/containers"
"git.lukeshu.com/btrfs-progs-ng/lib/jsonutil"
"git.lukeshu.com/btrfs-progs-ng/lib/textui"
)
// Result types ////////////////////////////////////////////////////////////////
type ScanResult struct {
Mappings []btrfsvol.Mapping
Devices ScanDevicesResult
}
type ScanDevicesResult = map[btrfsvol.DeviceID]ScanOneDeviceResult
type ScanOneDeviceResult struct {
Size btrfsvol.PhysicalAddr
Superblock jsonutil.Binary[btrfstree.Superblock]
Checksums btrfssum.SumRun[btrfsvol.PhysicalAddr]
FoundNodes map[btrfsvol.LogicalAddr][]btrfsvol.PhysicalAddr
FoundChunks []FoundChunk
FoundBlockGroups []FoundBlockGroup
FoundDevExtents []FoundDevExtent
FoundExtentCSums []FoundExtentCSum
}
type FoundChunk = btrfstree.SysChunk
type FoundBlockGroup struct {
Key btrfsprim.Key
BG btrfsitem.BlockGroup
}
type FoundDevExtent struct {
Key btrfsprim.Key
DevExt btrfsitem.DevExtent
}
type FoundExtentCSum struct {
Generation btrfsprim.Generation
Sums btrfsitem.ExtentCSum
}
// Compare implements containers.Ordered.
func (a FoundExtentCSum) Compare(b FoundExtentCSum) int {
return containers.NativeCompare(a.Sums.Addr, b.Sums.Addr)
}
// Convenience functions for those types ///////////////////////////////////////
func ScanDevices(ctx context.Context, fs *btrfs.FS) (ScanDevicesResult, error) {
return btrfsutil.ScanDevices[scanStats, ScanOneDeviceResult](ctx, fs, newDeviceScanner)
}
// ScanOneDevice mostly mimics btrfs-progs
// cmds/rescue-chunk-recover.c:scan_one_device().
func ScanOneDevice(ctx context.Context, dev *btrfs.Device) (ScanOneDeviceResult, error) {
return btrfsutil.ScanOneDevice[scanStats, ScanOneDeviceResult](ctx, dev, newDeviceScanner)
}
// scanner implementation //////////////////////////////////////////////////////
type deviceScanner struct {
sums strings.Builder
result ScanOneDeviceResult
}
type scanStats struct {
NumFoundNodes int
NumFoundChunks int
NumFoundBlockGroups int
NumFoundDevExtents int
NumFoundExtentCSums int
}
func (s scanStats) String() string {
return textui.Sprintf("found: %v nodes, %v chunks, %v block groups, %v dev extents, %v sum items",
s.NumFoundNodes,
s.NumFoundChunks,
s.NumFoundBlockGroups,
s.NumFoundDevExtents,
s.NumFoundExtentCSums)
}
func (scanner *deviceScanner) ScanStats() scanStats {
return scanStats{
NumFoundNodes: len(scanner.result.FoundNodes),
NumFoundChunks: len(scanner.result.FoundChunks),
NumFoundBlockGroups: len(scanner.result.FoundBlockGroups),
NumFoundDevExtents: len(scanner.result.FoundDevExtents),
NumFoundExtentCSums: len(scanner.result.FoundExtentCSums),
}
}
func newDeviceScanner(_ context.Context, sb btrfstree.Superblock, numBytes btrfsvol.PhysicalAddr, numSectors int) btrfsutil.DeviceScanner[scanStats, ScanOneDeviceResult] {
scanner := new(deviceScanner)
scanner.result.Size = numBytes
scanner.result.Superblock.Val = sb
scanner.result.FoundNodes = make(map[btrfsvol.LogicalAddr][]btrfsvol.PhysicalAddr)
scanner.result.Checksums.ChecksumSize = scanner.result.Superblock.Val.ChecksumType.Size()
scanner.sums.Grow(scanner.result.Checksums.ChecksumSize * numSectors)
return scanner
}
func (scanner *deviceScanner) ScanSector(_ context.Context, dev *btrfs.Device, paddr btrfsvol.PhysicalAddr) error {
sum, err := btrfs.ChecksumPhysical(dev, scanner.result.Superblock.Val.ChecksumType, paddr)
if err != nil {
return err
}
scanner.sums.Write(sum[:scanner.result.Checksums.ChecksumSize])
return nil
}
func (scanner *deviceScanner) ScanNode(ctx context.Context, addr btrfsvol.PhysicalAddr, node *btrfstree.Node) error {
scanner.result.FoundNodes[node.Head.Addr] = append(scanner.result.FoundNodes[node.Head.Addr], addr)
for i, item := range node.BodyLeaf {
switch item.Key.ItemType {
case btrfsitem.CHUNK_ITEM_KEY:
switch itemBody := item.Body.(type) {
case *btrfsitem.Chunk:
dlog.Tracef(ctx, "node@%v: item %v: found chunk",
addr, i)
scanner.result.FoundChunks = append(scanner.result.FoundChunks, FoundChunk{
Key: item.Key,
Chunk: itemBody.Clone(),
})
case *btrfsitem.Error:
dlog.Errorf(ctx, "node@%v: item %v: error: malformed CHUNK_ITEM: %v",
addr, i, itemBody.Err)
default:
panic(fmt.Errorf("should not happen: CHUNK_ITEM has unexpected item type: %T", itemBody))
}
case btrfsitem.BLOCK_GROUP_ITEM_KEY:
switch itemBody := item.Body.(type) {
case *btrfsitem.BlockGroup:
dlog.Tracef(ctx, "node@%v: item %v: found block group",
addr, i)
scanner.result.FoundBlockGroups = append(scanner.result.FoundBlockGroups, FoundBlockGroup{
Key: item.Key,
BG: itemBody.Clone(),
})
case *btrfsitem.Error:
dlog.Errorf(ctx, "node@%v: item %v: error: malformed BLOCK_GROUP_ITEM: %v",
addr, i, itemBody.Err)
default:
panic(fmt.Errorf("should not happen: BLOCK_GROUP_ITEM has unexpected item type: %T", itemBody))
}
case btrfsitem.DEV_EXTENT_KEY:
switch itemBody := item.Body.(type) {
case *btrfsitem.DevExtent:
dlog.Tracef(ctx, "node@%v: item %v: found dev extent",
addr, i)
scanner.result.FoundDevExtents = append(scanner.result.FoundDevExtents, FoundDevExtent{
Key: item.Key,
DevExt: itemBody.Clone(),
})
case *btrfsitem.Error:
dlog.Errorf(ctx, "node@%v: item %v: error: malformed DEV_EXTENT: %v",
addr, i, itemBody.Err)
default:
panic(fmt.Errorf("should not happen: DEV_EXTENT has unexpected item type: %T", itemBody))
}
case btrfsitem.EXTENT_CSUM_KEY:
switch itemBody := item.Body.(type) {
case *btrfsitem.ExtentCSum:
dlog.Tracef(ctx, "node@%v: item %v: found csums",
addr, i)
scanner.result.FoundExtentCSums = append(scanner.result.FoundExtentCSums, FoundExtentCSum{
Generation: node.Head.Generation,
Sums: itemBody.Clone(),
})
case *btrfsitem.Error:
dlog.Errorf(ctx, "node@%v: item %v: error: malformed is EXTENT_CSUM: %v",
addr, i, itemBody.Err)
default:
panic(fmt.Errorf("should not happen: EXTENT_CSUM has unexpected item type: %T", itemBody))
}
}
}
return nil
}
func (scanner *deviceScanner) ScanDone(_ context.Context) (ScanOneDeviceResult, error) {
scanner.result.Checksums.Sums = btrfssum.ShortSum(scanner.sums.String())
return scanner.result, nil
}
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