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Diffstat (limited to 'lib/btrfsprogs/btrfsinspect/scandevices.go')
-rw-r--r--lib/btrfsprogs/btrfsinspect/scandevices.go224
1 files changed, 224 insertions, 0 deletions
diff --git a/lib/btrfsprogs/btrfsinspect/scandevices.go b/lib/btrfsprogs/btrfsinspect/scandevices.go
new file mode 100644
index 0000000..13c5d60
--- /dev/null
+++ b/lib/btrfsprogs/btrfsinspect/scandevices.go
@@ -0,0 +1,224 @@
+// Copyright (C) 2022 Luke Shumaker <lukeshu@lukeshu.com>
+//
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+package btrfsinspect
+
+import (
+ "context"
+ "sort"
+
+ "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/btrfsvol"
+ "git.lukeshu.com/btrfs-progs-ng/lib/containers"
+ "git.lukeshu.com/btrfs-progs-ng/lib/diskio"
+ "git.lukeshu.com/btrfs-progs-ng/lib/maps"
+)
+
+type ScanOneDeviceResult struct {
+ FoundNodes map[btrfsvol.LogicalAddr][]btrfsvol.PhysicalAddr
+ FoundChunks []btrfs.SysChunk
+ FoundBlockGroups []SysBlockGroup
+ FoundDevExtents []SysDevExtent
+}
+
+type SysBlockGroup struct {
+ Key btrfs.Key
+ BG btrfsitem.BlockGroup
+}
+
+type SysDevExtent struct {
+ Key btrfs.Key
+ DevExt btrfsitem.DevExtent
+}
+
+func (found ScanOneDeviceResult) AddToLV(ctx context.Context, fs *btrfs.FS, dev *btrfs.Device) {
+ sb, _ := dev.Superblock()
+
+ total := len(found.FoundChunks) + len(found.FoundDevExtents)
+ for _, paddrs := range found.FoundNodes {
+ total += len(paddrs)
+ }
+ lastProgress := -1
+ done := 0
+ printProgress := func() {
+ pct := int(100 * float64(done) / float64(total))
+ if pct != lastProgress || done == total {
+ dlog.Infof(ctx, "... dev[%q] added %v%% of the mappings (%v/%v=>%v)",
+ dev.Name(), pct, done, total, len(fs.LV.Mappings()))
+ lastProgress = pct
+ }
+ }
+ printProgress()
+
+ for _, chunk := range found.FoundChunks {
+ for _, mapping := range chunk.Chunk.Mappings(chunk.Key) {
+ if err := fs.LV.AddMapping(mapping); err != nil {
+ dlog.Errorf(ctx, "... dev[%q] error: adding chunk: %v",
+ dev.Name(), err)
+ }
+ done++
+ printProgress()
+ }
+ }
+
+ for _, ext := range found.FoundDevExtents {
+ if err := fs.LV.AddMapping(ext.DevExt.Mapping(ext.Key)); err != nil {
+ dlog.Errorf(ctx, "... dev[%q] error: adding devext: %v",
+ dev.Name(), err)
+ }
+ done++
+ printProgress()
+ }
+
+ // Do the nodes last to avoid bloating the mappings table too
+ // much. (Because nodes are numerous and small, while the
+ // others are few and large; so it is likely that many of the
+ // nodes will be subsumed by other things.)
+ //
+ // Sort them so that progress numbers are predictable.
+ for _, laddr := range maps.SortedKeys(found.FoundNodes) {
+ for _, paddr := range found.FoundNodes[laddr] {
+ if err := fs.LV.AddMapping(btrfsvol.Mapping{
+ LAddr: laddr,
+ PAddr: btrfsvol.QualifiedPhysicalAddr{
+ Dev: sb.DevItem.DevID,
+ Addr: paddr,
+ },
+ Size: btrfsvol.AddrDelta(sb.NodeSize),
+ SizeLocked: false,
+ }); err != nil {
+ dlog.Errorf(ctx, "... dev[%q] error: adding node ident: %v",
+ dev.Name(), err)
+ }
+ done++
+ printProgress()
+ }
+ }
+
+ // Use block groups to add missing flags (and as a hint to
+ // combine node entries).
+ //
+ // First dedup them, because they change for allocations and
+ // CoW means that they'll bounce around a lot, so you likely
+ // have oodles of duplicates?
+ type blockgroup struct {
+ LAddr btrfsvol.LogicalAddr
+ Size btrfsvol.AddrDelta
+ Flags btrfsvol.BlockGroupFlags
+ }
+ bgsSet := make(map[blockgroup]struct{})
+ for _, bg := range found.FoundBlockGroups {
+ bgsSet[blockgroup{
+ LAddr: btrfsvol.LogicalAddr(bg.Key.ObjectID),
+ Size: btrfsvol.AddrDelta(bg.Key.Offset),
+ Flags: bg.BG.Flags,
+ }] = struct{}{}
+ }
+ bgsOrdered := maps.Keys(bgsSet)
+ sort.Slice(bgsOrdered, func(i, j int) bool {
+ return bgsOrdered[i].LAddr < bgsOrdered[j].LAddr
+ })
+ for _, bg := range bgsOrdered {
+ otherLAddr, otherPAddr := fs.LV.ResolveAny(bg.LAddr, bg.Size)
+ if otherLAddr < 0 || otherPAddr.Addr < 0 {
+ dlog.Errorf(ctx, "... dev[%q] error: could not pair blockgroup laddr=%v (size=%v flags=%v) with a mapping",
+ dev.Name(), bg.LAddr, bg.Size, bg.Flags)
+ continue
+ }
+
+ offsetWithinChunk := otherLAddr.Sub(bg.LAddr)
+ mapping := btrfsvol.Mapping{
+ LAddr: bg.LAddr,
+ PAddr: otherPAddr.Add(-offsetWithinChunk),
+ Size: bg.Size,
+ SizeLocked: true,
+ Flags: containers.Optional[btrfsvol.BlockGroupFlags]{
+ OK: true,
+ Val: bg.Flags,
+ },
+ }
+ if err := fs.LV.AddMapping(mapping); err != nil {
+ dlog.Errorf(ctx, "... dev[%q] error: adding flags from blockgroup: %v",
+ dev.Name(), err)
+ }
+ }
+}
+
+// ScanOneDevice mostly mimics btrfs-progs
+// cmds/rescue-chunk-recover.c:scan_one_device().
+func ScanOneDevice(ctx context.Context, dev *btrfs.Device, superblock btrfs.Superblock) (ScanOneDeviceResult, error) {
+ result := ScanOneDeviceResult{
+ FoundNodes: make(map[btrfsvol.LogicalAddr][]btrfsvol.PhysicalAddr),
+ }
+
+ devSize := dev.Size()
+ lastProgress := -1
+
+ err := ScanForNodes(ctx, dev, superblock, func(nodeRef *diskio.Ref[btrfsvol.PhysicalAddr, btrfs.Node], err error) {
+ if err != nil {
+ dlog.Infof(ctx, "... dev[%q] error: %v", dev.Name(), err)
+ return
+ }
+ result.FoundNodes[nodeRef.Data.Head.Addr] = append(result.FoundNodes[nodeRef.Data.Head.Addr], nodeRef.Addr)
+ for i, item := range nodeRef.Data.BodyLeaf {
+ switch item.Key.ItemType {
+ case btrfsitem.CHUNK_ITEM_KEY:
+ chunk, ok := item.Body.(btrfsitem.Chunk)
+ if !ok {
+ dlog.Errorf(ctx, "... dev[%q] node@%v: item %v: error: type is CHUNK_ITEM_KEY, but struct is %T",
+ dev.Name(), nodeRef.Addr, i, item.Body)
+ continue
+ }
+ //dlog.Tracef(ctx, "... dev[%q] node@%v: item %v: found chunk",
+ // dev.Name(), nodeRef.Addr, i)
+ result.FoundChunks = append(result.FoundChunks, btrfs.SysChunk{
+ Key: item.Key,
+ Chunk: chunk,
+ })
+ case btrfsitem.BLOCK_GROUP_ITEM_KEY:
+ bg, ok := item.Body.(btrfsitem.BlockGroup)
+ if !ok {
+ dlog.Errorf(ctx, "... dev[%q] node@%v: item %v: error: type is BLOCK_GROUP_ITEM_KEY, but struct is %T",
+ dev.Name(), nodeRef.Addr, i, item.Body)
+ continue
+ }
+ //dlog.Tracef(ctx, "... dev[%q] node@%v: item %v: found block group",
+ // dev.Name(), nodeRef.Addr, i)
+ result.FoundBlockGroups = append(result.FoundBlockGroups, SysBlockGroup{
+ Key: item.Key,
+ BG: bg,
+ })
+ case btrfsitem.DEV_EXTENT_KEY:
+ devext, ok := item.Body.(btrfsitem.DevExtent)
+ if !ok {
+ dlog.Errorf(ctx, "... dev[%q] node@%v: item %v: error: type is DEV_EXTENT_KEY, but struct is %T",
+ dev.Name(), nodeRef.Addr, i, item.Body)
+ continue
+ }
+ //dlog.Tracef(ctx, "... dev[%q] node@%v: item %v: found dev extent",
+ // dev.Name(), nodeRef.Addr, i)
+ result.FoundDevExtents = append(result.FoundDevExtents, SysDevExtent{
+ Key: item.Key,
+ DevExt: devext,
+ })
+ }
+ }
+ }, func(pos btrfsvol.PhysicalAddr) {
+ pct := int(100 * float64(pos) / float64(devSize))
+ if pct != lastProgress || pos == devSize {
+ dlog.Infof(ctx, "... dev[%q] scanned %v%% (found: %v nodes, %v chunks, %v block groups, %v dev extents)",
+ dev.Name(), pct,
+ len(result.FoundNodes),
+ len(result.FoundChunks),
+ len(result.FoundBlockGroups),
+ len(result.FoundDevExtents))
+ lastProgress = pct
+ }
+ })
+
+ return result, err
+}
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2024-11-08 08:10:33 +0000