[Cram] Add support for analyze command

This commit is contained in:
2026-04-11 00:54:39 +01:00
parent 4ba468b98e
commit 98573e524d

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@@ -0,0 +1,359 @@
// /***************************************************************************
// Aaru Data Preservation Suite
// ----------------------------------------------------------------------------
//
// Filename : Analyze.cs
// Author(s) : Natalia Portillo <claunia@claunia.com>
//
// Component : Cram file system plugin.
//
// --[ Description ] ----------------------------------------------------------
//
// Sector overlap analysis for CramFS volumes.
//
// --[ 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;
namespace Aaru.Filesystems;
/// <inheritdoc />
public sealed partial class Cram
{
#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))
.OrderBy(static entry => entry, StringComparer.Ordinal)
.ToArray();
long maximum = orderedEntries.Length > 0 ? orderedEntries.Length : 1;
for(var i = 0; i < orderedEntries.Length; i++)
{
string entryPath = path == "/" ? "/" + orderedEntries[i] : path + "/" + orderedEntries[i];
updateProgress?.Invoke(entryPath, i + 1, maximum);
errno = LookupFile(entryPath, out DirectoryEntryInfo entry);
if(errno != ErrorNumber.NoError) return errno;
if(IsDirectory(GetInodeMode(entry.Inode)))
{
errno = TraverseDirectoryForAffectedSectors(entryPath,
sectorExtents,
files,
updateProgress,
pulseProgress);
if(errno != ErrorNumber.NoError) return errno;
continue;
}
errno = AddOverlappingFile(entryPath, entry, sectorExtents, files);
if(errno != ErrorNumber.NoError) return errno;
}
return ErrorNumber.NoError;
}
finally
{
CloseDir(node);
}
}
ErrorNumber AddOverlappingFile(string path, DirectoryEntryInfo entry,
IReadOnlyList<(ulong Start, ulong End)> sectorExtents, List<FileSectorInfo> files)
{
uint size = GetInodeSize(entry.Inode);
if(size == 0) return ErrorNumber.NoError;
ErrorNumber errno =
FindOverlappingExtents(entry.Inode, size, 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 = entry.Offset,
AffectedSectors = overlaps
});
return ErrorNumber.NoError;
}
ErrorNumber FindOverlappingExtents(Inode inode, uint size, IReadOnlyList<(ulong Start, ulong End)> sectorExtents,
out List<(ulong Start, ulong End)> overlaps)
{
overlaps = [];
if(size == 0) return ErrorNumber.NoError;
uint blockPtrOffset = GetInodeOffset(inode) << 2;
uint blockCount = (size + PAGE_SIZE - 1) / PAGE_SIZE;
for(var blockIndex = 0; blockIndex < blockCount; blockIndex++)
{
ErrorNumber errno = GetCompressedBlockRange(blockPtrOffset,
blockCount,
size,
blockIndex,
out uint blockStart,
out uint blockLength);
if(errno != ErrorNumber.NoError) return errno;
if(blockLength == 0) continue;
AddByteRangeOverlaps((ulong)_baseOffset + blockStart, blockLength, sectorExtents, overlaps);
}
overlaps = NormalizeAnalyzeExtents(overlaps);
return ErrorNumber.NoError;
}
ErrorNumber GetCompressedBlockRange(uint blockPtrOffset, uint blockCount, uint fileSize, int blockIndex,
out uint blockStart, out uint blockLength)
{
blockStart = 0;
blockLength = 0;
if(blockIndex < 0 || blockIndex >= blockCount) return ErrorNumber.InvalidArgument;
uint pointerOffset = blockPtrOffset + (uint)blockIndex * 4;
ErrorNumber errno = ReadBytes(pointerOffset, 4, out byte[] ptrData);
if(errno != ErrorNumber.NoError) return errno;
uint blockPtr = _littleEndian
? BitConverter.ToUInt32(ptrData, 0)
: (uint)(ptrData[0] << 24 | ptrData[1] << 16 | ptrData[2] << 8 | ptrData[3]);
bool uncompressed = (blockPtr & CRAMFS_BLK_FLAG_UNCOMPRESSED) != 0;
bool direct = (blockPtr & CRAMFS_BLK_FLAG_DIRECT_PTR) != 0;
blockPtr &= ~CRAMFS_BLK_FLAGS;
if(direct)
{
blockStart = blockPtr << CRAMFS_BLK_DIRECT_PTR_SHIFT;
if(uncompressed)
{
blockLength = PAGE_SIZE;
if(blockIndex == blockCount - 1)
{
blockLength = fileSize % PAGE_SIZE;
if(blockLength == 0) blockLength = PAGE_SIZE;
}
}
else
{
errno = ReadBytes(blockStart, 2, out byte[] sizeData);
if(errno != ErrorNumber.NoError) return errno;
blockLength = _littleEndian
? BitConverter.ToUInt16(sizeData, 0)
: (uint)(sizeData[0] << 8 | sizeData[1]);
blockStart += 2;
}
}
else
{
blockStart = blockPtrOffset + blockCount * 4;
if(blockIndex > 0)
{
errno = ReadBytes(pointerOffset - 4, 4, out byte[] previousPtrData);
if(errno != ErrorNumber.NoError) return errno;
uint previousPtr = _littleEndian
? BitConverter.ToUInt32(previousPtrData, 0)
: (uint)(previousPtrData[0] << 24 |
previousPtrData[1] << 16 |
previousPtrData[2] << 8 |
previousPtrData[3]);
if((previousPtr & CRAMFS_BLK_FLAG_DIRECT_PTR) != 0)
{
uint previousStart = (previousPtr & ~CRAMFS_BLK_FLAGS) << CRAMFS_BLK_DIRECT_PTR_SHIFT;
if((previousPtr & CRAMFS_BLK_FLAG_UNCOMPRESSED) != 0)
blockStart = previousStart + PAGE_SIZE;
else
{
errno = ReadBytes(previousStart, 2, out byte[] previousSizeData);
if(errno != ErrorNumber.NoError) return errno;
uint previousLength = _littleEndian
? BitConverter.ToUInt16(previousSizeData, 0)
: (uint)(previousSizeData[0] << 8 | previousSizeData[1]);
blockStart = previousStart + 2 + previousLength;
}
}
else
blockStart = previousPtr & ~CRAMFS_BLK_FLAGS;
}
blockLength = (blockPtr & ~CRAMFS_BLK_FLAGS) - blockStart;
}
if(blockLength == 0) return ErrorNumber.NoError;
if(blockLength > 2 * PAGE_SIZE || uncompressed && blockLength > PAGE_SIZE) return ErrorNumber.InvalidArgument;
return ErrorNumber.NoError;
}
void AddByteRangeOverlaps(ulong absoluteByteOffset, 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 + absoluteByteOffset / sectorSize;
ulong offsetInSector = absoluteByteOffset % sectorSize;
ulong sectorsInRun = (lengthBytes + offsetInSector + sectorSize - 1) / sectorSize;
if(sectorsInRun == 0) sectorsInRun = 1;
AddExtentOverlaps(startSector, startSector + sectorsInRun - 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)
{
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;
}
}