diff options
author | Luke Shumaker <lukeshu@lukeshu.com> | 2022-06-05 16:46:34 -0600 |
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committer | Luke Shumaker <lukeshu@lukeshu.com> | 2022-06-05 16:46:34 -0600 |
commit | 74b109b0a75ae6648f9381252d8beb5ce6025df3 (patch) | |
tree | 64b8b2250c67f749566761bab56676bed9c33846 /pkg/btrfsmisc/fsck.go | |
parent | e134a9fbd0d8ae43e2d24c5aabad8bf6a16190ed (diff) |
factor out a btrfsmisc pacage
Diffstat (limited to 'pkg/btrfsmisc/fsck.go')
-rw-r--r-- | pkg/btrfsmisc/fsck.go | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/pkg/btrfsmisc/fsck.go b/pkg/btrfsmisc/fsck.go new file mode 100644 index 0000000..527329d --- /dev/null +++ b/pkg/btrfsmisc/fsck.go @@ -0,0 +1,54 @@ +package btrfsmisc + +import ( + "fmt" + + "lukeshu.com/btrfs-tools/pkg/binstruct" + "lukeshu.com/btrfs-tools/pkg/btrfs" + "lukeshu.com/btrfs-tools/pkg/util" +) + +// ScanForNodes mimics btrfs-progs +// cmds/rescue-chunk-recover.c:scan_one_device(), except it doesn't do +// anything but log when it finds a node. +func ScanForNodes(dev *btrfs.Device, sb btrfs.Superblock) error { + devSize, err := dev.Size() + if err != nil { + return err + } + + if sb.NodeSize < sb.SectorSize { + return fmt.Errorf("node_size(%d) < sector_size(%d)", + sb.NodeSize, sb.SectorSize) + } + + nodeBuf := make([]byte, sb.NodeSize) + for pos := btrfs.PhysicalAddr(0); pos+btrfs.PhysicalAddr(sb.SectorSize) < devSize; pos += btrfs.PhysicalAddr(sb.SectorSize) { + if util.InSlice(pos, btrfs.SuperblockAddrs) { + fmt.Printf("sector@%d is a superblock\n", pos) + continue + } + if _, err := dev.ReadAt(nodeBuf, pos); err != nil { + return fmt.Errorf("sector@%d: %w", pos, err) + } + var nodeHeader btrfs.NodeHeader + if _, err := binstruct.Unmarshal(nodeBuf, &nodeHeader); err != nil { + return fmt.Errorf("sector@%d: %w", pos, err) + } + if !nodeHeader.MetadataUUID.Equal(sb.EffectiveMetadataUUID()) { + //fmt.Printf("sector@%d does not look like a node\n", pos) + continue + } + if !nodeHeader.Checksum.Equal(btrfs.CRC32c(nodeBuf[0x20:])) { + fmt.Printf("sector@%d looks like a node but is corrupt (checksum doesn't match)\n", pos) + continue + } + + fmt.Printf("node@%d: physical_addr=0x%0X logical_addr=0x%0X generation=%d owner=%v level=%d\n", + pos, pos, nodeHeader.Addr, nodeHeader.Generation, nodeHeader.Owner, nodeHeader.Level) + + pos += btrfs.PhysicalAddr(sb.NodeSize) - btrfs.PhysicalAddr(sb.SectorSize) + } + + return nil +} |