[btrfs] Add support for analyze command

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2026-04-11 08:48:00 +01:00
parent 65387466f9
commit fb295f72ac

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// /***************************************************************************
// Aaru Data Preservation Suite
// ----------------------------------------------------------------------------
//
// Filename : Analyze.cs
// Author(s) : Natalia Portillo <claunia@claunia.com>
//
// Component : B-tree file system plugin.
//
// --[ License ] --------------------------------------------------------------
//
// This library is free software; you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as
// published by the Free Software Foundation; either version 2.1 of the
// License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, see <http://www.gnu.org/licenses/>.
//
// ----------------------------------------------------------------------------
// Copyright © 2011-2026 Natalia Portillo
// ****************************************************************************/
using System;
using System.Collections.Generic;
using System.Linq;
using Aaru.CommonTypes;
using Aaru.CommonTypes.Enums;
using Aaru.CommonTypes.Interfaces;
using Aaru.CommonTypes.Structs;
using FileAttributes = Aaru.CommonTypes.Structs.FileAttributes;
using Marshal = Aaru.Helpers.Marshal;
namespace Aaru.Filesystems;
public sealed partial class BTRFS
{
#region IReadOnlyFilesystem Members
/// <inheritdoc />
public ErrorNumber GetFilesWithAffectedSectors(IEnumerable<(ulong Start, ulong End)> sectorExtents,
out List<FileSectorInfo> files,
InitProgressHandler initProgress = null,
UpdateProgressHandler updateProgress = null,
PulseProgressHandler pulseProgress = null,
EndProgressHandler endProgress = null)
{
files = [];
if(!_mounted) return ErrorNumber.AccessDenied;
if(sectorExtents is null) return ErrorNumber.InvalidArgument;
List<(ulong Start, ulong End)> normalizedExtents = NormalizeAnalyzeExtents(sectorExtents);
if(normalizedExtents.Count == 0) return ErrorNumber.NoError;
try
{
initProgress?.Invoke();
return TraverseDirectoryForAffectedSectors("/",
normalizedExtents,
files,
updateProgress,
pulseProgress);
}
finally
{
endProgress?.Invoke();
}
}
#endregion
ErrorNumber TraverseDirectoryForAffectedSectors(string path,
IReadOnlyList<(ulong Start, ulong End)> sectorExtents,
List<FileSectorInfo> files,
UpdateProgressHandler updateProgress,
PulseProgressHandler pulseProgress)
{
pulseProgress?.Invoke(path);
ErrorNumber errno = OpenDir(path, out IDirNode node);
if(errno != ErrorNumber.NoError) return errno;
try
{
List<string> entries = [];
while(true)
{
errno = ReadDir(node, out string entryName);
if(errno != ErrorNumber.NoError) return errno;
if(entryName is null) break;
entries.Add(entryName);
}
string[] orderedEntries = entries.Where(static entry =>
!string.IsNullOrWhiteSpace(entry) &&
entry is not "." and not "..")
.OrderBy(static entry => entry, StringComparer.Ordinal)
.ToArray();
long maximum = orderedEntries.Length > 0 ? orderedEntries.Length : 1;
for(int i = 0; i < orderedEntries.Length; i++)
{
string entryPath = path == "/" ? "/" + orderedEntries[i] : path + "/" + orderedEntries[i];
updateProgress?.Invoke(entryPath, i + 1, maximum);
errno = Stat(entryPath, out FileEntryInfo stat);
if(errno != ErrorNumber.NoError) return errno;
if(stat.Attributes.HasFlag(FileAttributes.Directory))
{
errno = TraverseDirectoryForAffectedSectors(entryPath,
sectorExtents,
files,
updateProgress,
pulseProgress);
if(errno != ErrorNumber.NoError) return errno;
continue;
}
errno = AddOverlappingFile(entryPath, sectorExtents, files);
if(errno != ErrorNumber.NoError) return errno;
}
return ErrorNumber.NoError;
}
finally
{
CloseDir(node);
}
}
ErrorNumber AddOverlappingFile(string path, IReadOnlyList<(ulong Start, ulong End)> sectorExtents,
List<FileSectorInfo> files)
{
ErrorNumber errno = ResolvePath(path, out ulong objectId, out ulong treeRoot);
if(errno != ErrorNumber.NoError) return errno;
errno = ReadInode(objectId, treeRoot, out InodeItem inode);
if(errno != ErrorNumber.NoError) return errno;
if(inode.size == 0) return ErrorNumber.NoError;
errno = FindOverlappingExtents(objectId, treeRoot, sectorExtents, out List<(ulong Start, ulong End)> overlaps);
if(errno != ErrorNumber.NoError) return errno;
if(overlaps.Count == 0) return ErrorNumber.NoError;
files.Add(new FileSectorInfo
{
Path = path,
Inode = objectId,
AffectedSectors = overlaps
});
return ErrorNumber.NoError;
}
ErrorNumber FindOverlappingExtents(ulong objectId, ulong treeRoot,
IReadOnlyList<(ulong Start, ulong End)> sectorExtents,
out List<(ulong Start, ulong End)> overlaps)
{
overlaps = [];
ErrorNumber errno = ReadTreeBlock(treeRoot, out byte[] fsTreeData);
if(errno != ErrorNumber.NoError) return errno;
Header fsTreeHeader = Marshal.ByteArrayToStructureLittleEndian<Header>(fsTreeData);
List<ExtentEntry> extents = [];
errno = WalkTreeForExtents(fsTreeData, fsTreeHeader, objectId, extents);
if(errno != ErrorNumber.NoError) return errno;
extents.Sort(static (left, right) => left.FileOffset.CompareTo(right.FileOffset));
foreach(ExtentEntry extent in extents)
{
switch(extent.Type)
{
case BTRFS_FILE_EXTENT_INLINE:
case BTRFS_FILE_EXTENT_PREALLOC:
continue;
case BTRFS_FILE_EXTENT_REG:
if(extent.DiskBytenr == 0) continue;
if(extent.Compression != BTRFS_COMPRESS_NONE)
AddLogicalByteRangeOverlaps(extent.DiskBytenr, extent.DiskBytes, sectorExtents, overlaps);
else
AddLogicalByteRangeOverlaps(extent.DiskBytenr + extent.ExtentOffset,
extent.Length,
sectorExtents,
overlaps);
break;
}
}
overlaps = NormalizeAnalyzeExtents(overlaps);
return ErrorNumber.NoError;
}
void AddLogicalByteRangeOverlaps(ulong logicalByteOffset, ulong lengthBytes,
IReadOnlyList<(ulong Start, ulong End)> sectorExtents,
List<(ulong Start, ulong End)> overlaps)
{
ulong remainingBytes = lengthBytes;
ulong currentLogical = logicalByteOffset;
while(remainingBytes > 0)
{
ChunkMapping? currentMapping = null;
foreach(ChunkMapping mapping in _chunkMap)
{
if(currentLogical < mapping.LogicalOffset || currentLogical >= mapping.LogicalOffset + mapping.Length)
continue;
currentMapping = mapping;
break;
}
if(currentMapping is null) break;
ulong bytesInChunk = Math.Min(remainingBytes,
currentMapping.Value.LogicalOffset + currentMapping.Value.Length - currentLogical);
ulong physicalByte = LogicalToPhysical(currentLogical);
if(physicalByte == ulong.MaxValue) break;
AddPhysicalByteRangeOverlaps(physicalByte, bytesInChunk, sectorExtents, overlaps);
currentLogical += bytesInChunk;
remainingBytes -= bytesInChunk;
}
}
void AddPhysicalByteRangeOverlaps(ulong physicalByteOffset, ulong lengthBytes,
IReadOnlyList<(ulong Start, ulong End)> sectorExtents,
List<(ulong Start, ulong End)> overlaps)
{
if(lengthBytes == 0) return;
ulong sectorSize = _imagePlugin.Info.SectorSize;
ulong startSector = _partition.Start + physicalByteOffset / sectorSize;
ulong offsetInSector = physicalByteOffset % sectorSize;
ulong sectorCount = (lengthBytes + offsetInSector + sectorSize - 1) / sectorSize;
if(sectorCount == 0) sectorCount = 1;
AddExtentOverlaps(startSector, startSector + sectorCount - 1, sectorExtents, overlaps);
}
static void AddExtentOverlaps(ulong startSector, ulong endSector,
IReadOnlyList<(ulong Start, ulong End)> sectorExtents,
List<(ulong Start, ulong End)> overlaps)
{
foreach((ulong Start, ulong End) requestedExtent in sectorExtents)
{
if(requestedExtent.End < startSector || requestedExtent.Start > endSector) continue;
overlaps.Add((Math.Max(startSector, requestedExtent.Start), Math.Min(endSector, requestedExtent.End)));
}
}
static List<(ulong Start, ulong End)> NormalizeAnalyzeExtents(IEnumerable<(ulong Start, ulong End)> extents)
{
List<(ulong Start, ulong End)> orderedExtents = extents.Where(static extent => extent.End >= extent.Start)
.OrderBy(static extent => extent.Start)
.ThenBy(static extent => extent.End)
.ToList();
List<(ulong Start, ulong End)> normalizedExtents = [];
if(orderedExtents.Count == 0) return normalizedExtents;
(ulong Start, ulong End) currentExtent = orderedExtents[0];
for(int i = 1; i < orderedExtents.Count; i++)
{
if(orderedExtents[i].Start <= currentExtent.End + 1)
{
currentExtent.End = Math.Max(currentExtent.End, orderedExtents[i].End);
continue;
}
normalizedExtents.Add(currentExtent);
currentExtent = orderedExtents[i];
}
normalizedExtents.Add(currentExtent);
return normalizedExtents;
}
}