[ext2/3/4] Add support for analyze command

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2026-04-10 21:14:19 +01:00
parent c3b8e68f37
commit 476ae51494

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// /***************************************************************************
// Aaru Data Preservation Suite
// ----------------------------------------------------------------------------
//
// Filename : Analyze.cs
// Author(s) : Natalia Portillo <claunia@claunia.com>
//
// Component : Linux extended filesystem 2, 3 and 4 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.Structs;
namespace Aaru.Filesystems;
// ReSharper disable once InconsistentNaming
public sealed partial class ext2FS
{
#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("/",
EXT2_ROOT_INO,
normalizedExtents,
files,
updateProgress,
pulseProgress);
}
finally
{
endProgress?.Invoke();
}
}
#endregion
ErrorNumber TraverseDirectoryForAffectedSectors(string path, uint directoryInodeNumber,
List<(ulong Start, ulong End)> sectorExtents,
List<FileSectorInfo> files, UpdateProgressHandler updateProgress,
PulseProgressHandler pulseProgress)
{
pulseProgress?.Invoke(path);
ErrorNumber errno = ReadInode(directoryInodeNumber, out Inode directoryInode);
if(errno != ErrorNumber.NoError) return errno;
if((directoryInode.mode & S_IFMT) != S_IFDIR) return ErrorNumber.NotDirectory;
errno = GetDirectoryEntries(directoryInodeNumber,
directoryInode,
out Dictionary<string, uint> directoryEntries);
if(errno != ErrorNumber.NoError) return errno;
KeyValuePair<string, uint>[] orderedEntries = directoryEntries
.Where(static entry =>
!string.IsNullOrWhiteSpace(entry.Key) &&
entry.Key is not "." and not "..")
.OrderBy(static entry => entry.Key, StringComparer.Ordinal)
.ToArray();
long maximum = orderedEntries.Length > 0 ? orderedEntries.Length : 1;
for(var i = 0; i < orderedEntries.Length; i++)
{
string entryPath = path == "/" ? "/" + orderedEntries[i].Key : path + "/" + orderedEntries[i].Key;
updateProgress?.Invoke(entryPath, i + 1, maximum);
errno = ReadInode(orderedEntries[i].Value, out Inode inode);
if(errno != ErrorNumber.NoError) return errno;
if((inode.mode & S_IFMT) == S_IFDIR)
{
errno = TraverseDirectoryForAffectedSectors(entryPath,
orderedEntries[i].Value,
sectorExtents,
files,
updateProgress,
pulseProgress);
if(errno != ErrorNumber.NoError) return errno;
continue;
}
errno = AddOverlappingFile(entryPath, orderedEntries[i].Value, inode, sectorExtents, files);
if(errno != ErrorNumber.NoError) return errno;
}
return ErrorNumber.NoError;
}
ErrorNumber GetDirectoryEntries(uint directoryInodeNumber, in Inode directoryInode,
out Dictionary<string, uint> directoryEntries)
{
if(directoryInodeNumber == EXT2_ROOT_INO)
{
directoryEntries = new Dictionary<string, uint>(_rootDirectoryCache, StringComparer.Ordinal);
return ErrorNumber.NoError;
}
ulong directorySize = (ulong)directoryInode.size_high << 32 | directoryInode.size_lo;
return ReadDirectoryEntries(directoryInode, directoryInodeNumber, directorySize, out directoryEntries);
}
ErrorNumber AddOverlappingFile(string path, uint inodeNumber, in Inode inode,
IReadOnlyList<(ulong Start, ulong End)> sectorExtents, List<FileSectorInfo> files)
{
ulong logicalSize = (ulong)inode.size_high << 32 | inode.size_lo;
if(logicalSize == 0) return ErrorNumber.NoError;
List<(ulong Start, ulong End)> overlaps;
if((inode.i_flags & EXT4_INLINE_DATA_FL) != 0)
overlaps = FindInlineOverlaps(inodeNumber, logicalSize, sectorExtents);
else
{
ErrorNumber errno = GetInodeDataBlocks(inode,
out List<(ulong physicalBlock, uint length, bool unwritten)>
blockList);
if(errno != ErrorNumber.NoError) return errno;
overlaps = FindOverlappingExtents(blockList, logicalSize, sectorExtents);
}
if(overlaps.Count == 0) return ErrorNumber.NoError;
files.Add(new FileSectorInfo
{
Path = path,
Inode = inodeNumber,
AffectedSectors = overlaps
});
return ErrorNumber.NoError;
}
List<(ulong Start, ulong End)> FindInlineOverlaps(uint inodeNumber, ulong logicalSize,
IReadOnlyList<(ulong Start, ulong End)> sectorExtents)
{
List<(ulong Start, ulong End)> overlaps = [];
ErrorNumber errno = GetInodeByteOffset(inodeNumber, out ulong inodeByteOffset);
if(errno != ErrorNumber.NoError) return overlaps;
ulong sectorSize = _imagePlugin.Info.SectorSize;
ulong bytesInExtent = Math.Max(1, Math.Min(logicalSize, _inodeSize));
ulong startSector = _partition.Start + inodeByteOffset / sectorSize;
ulong offsetInSector = inodeByteOffset % sectorSize;
ulong sectorCount = (bytesInExtent + offsetInSector + sectorSize - 1) / sectorSize;
if(sectorCount == 0) sectorCount = 1;
AddExtentOverlaps(startSector, startSector + sectorCount - 1, sectorExtents, overlaps);
return NormalizeAnalyzeExtents(overlaps);
}
List<(ulong Start, ulong End)> FindOverlappingExtents(
IReadOnlyList<(ulong physicalBlock, uint length, bool unwritten)> blockList, ulong logicalSize,
IReadOnlyList<(ulong Start, ulong End)> sectorExtents)
{
List<(ulong Start, ulong End)> overlaps = [];
ulong remainingBytes = logicalSize;
ulong sectorSize = _imagePlugin.Info.SectorSize;
foreach((ulong physicalBlock, uint length, bool unwritten) extent in blockList)
{
if(remainingBytes == 0) break;
if(extent.length == 0) continue;
ulong extentBytes = Math.Min((ulong)extent.length * _blockSize, remainingBytes);
if(extentBytes == 0) break;
ulong byteOffset = extent.physicalBlock * _blockSize;
ulong startSector = _partition.Start + byteOffset / sectorSize;
ulong offsetInSector = byteOffset % sectorSize;
ulong sectorsInExtent = (extentBytes + offsetInSector + sectorSize - 1) / sectorSize;
if(sectorsInExtent == 0) sectorsInExtent = 1;
AddExtentOverlaps(startSector, startSector + sectorsInExtent - 1, sectorExtents, overlaps);
remainingBytes -= extentBytes;
}
return NormalizeAnalyzeExtents(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)
{
var 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(var 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;
}
}