public FatDirectoryEntry CreateSub(Fat fat)
{
var chain = new ClusterChain(fat, false);
chain.SetChainLength(1);
var entry = FatDirectoryEntry.Create(true);
entry.SetStartCluster(chain.GetStartCluster());
var dir =
new ClusterChainDirectory(chain, false);
/* add "." entry */
var dot = FatDirectoryEntry.Create(true);
dot.SetShortName(ShortName.Dot);
dot.SetStartCluster(dir.GetStorageCluster());
CopyDateTimeFields(entry, dot);
dir.AddEntry(dot);
/* add ".." entry */
var dotDot = FatDirectoryEntry.Create(true);
dotDot.SetShortName(ShortName.DotDot);
dotDot.SetStartCluster(GetStorageCluster());
CopyDateTimeFields(entry, dotDot);
dir.AddEntry(dotDot);
dir.Flush();
return(entry);
}
public static ClusterChainDirectory ReadRoot(ClusterChain chain)
{
var result = new ClusterChainDirectory(chain, true);
result.Read();
return(result);
}
/// <summary>
/// Constructor for FatFileSystem in specified readOnly mode
/// </summary>
/// <param name="device">the <see cref="IBlockDevice"/> holding the file system</param>
/// <param name="readOnly"></param>
/// <param name="ignoreFatDifferences"></param>
/// <exception cref="IOException">IOException on read error</exception>
private FatFileSystem(IBlockDevice device, bool readOnly,
bool ignoreFatDifferences) : base(readOnly)
{
bs = BootSector.Read(device);
if (bs.GetNrFats() <= 0)
{
throw new IOException(
"boot sector says there are no FATs");
}
filesOffset = FatUtils.GetFilesOffset(bs);
fatType = bs.GetFatType();
fat = Fat.Read(bs, 0);
if (!ignoreFatDifferences)
{
for (var i = 1; i < bs.GetNrFats(); i++)
{
var tmpFat = Fat.Read(bs, i);
if (!fat.Equals(tmpFat))
{
throw new IOException("FAT " + i + " differs from FAT 0");
}
}
}
if (fatType == FatType.BaseFat32)
{
var f32Bs = (Fat32BootSector)bs;
var rootDirFile = new ClusterChain(fat,
f32Bs.GetRootDirFirstCluster(), IsReadOnly());
rootDirStore = ClusterChainDirectory.ReadRoot(rootDirFile);
fsiSector = FsInfoSector.Read(f32Bs);
if (fsiSector.GetFreeClusterCount() != fat.GetFreeClusterCount())
{
throw new IOException("free cluster count mismatch - fat: " +
fat.GetFreeClusterCount() + " - fsinfo: " +
fsiSector.GetFreeClusterCount());
}
}
else
{
rootDirStore =
Fat16RootDirectory.Read((Fat16BootSector)bs, readOnly);
fsiSector = null;
}
rootDir = new FatLfnDirectory(rootDirStore, fat, IsReadOnly());
}
private static ClusterChainDirectory Read(FatDirectoryEntry entry, Fat fat)
{
if (!entry.IsDirectory())
{
throw
new ArgumentException(entry + " is no directory");
}
var chain = new ClusterChain(
fat, entry.GetStartCluster(),
entry.IsReadonlyFlag());
var result =
new ClusterChainDirectory(chain, false);
result.Read();
return(result);
}
public static ClusterChainDirectory CreateRoot(Fat fat)
{
if (fat.GetFatType() != FatType.BaseFat32)
{
throw new ArgumentException(
"only FAT32 stores root directory in a cluster chain");
}
var bs = (Fat32BootSector)fat.GetBootSector();
var cc = new ClusterChain(fat, false);
cc.SetChainLength(1);
bs.SetRootDirFirstCluster(cc.GetStartCluster());
var result =
new ClusterChainDirectory(cc, true);
result.Flush();
return(result);
}
/// <summary>
/// Initializes the boot sector and file system for the device. The file
/// system created by this method will always be in read-write mode.
/// </summary>
/// <returns>the file system that was created</returns>
/// <exception cref="System.IO.IOException">IOException on write error</exception>
public FatFileSystem Format()
{
var sectorSize = device.GetSectorSize();
var totalSectors = (int)(device.GetSize() / sectorSize);
FsInfoSector fsi;
BootSector bs;
if (sectorsPerCluster == 0)
{
throw new Exception();
}
if (fatType == FatType.BaseFat32)
{
bs = new Fat32BootSector(device);
InitBootSector(bs);
var f32Bs = (Fat32BootSector)bs;
f32Bs.SetFsInfoSectorNr(1);
f32Bs.SetSectorsPerFat(SectorsPerFat(0, totalSectors));
var rnd = new Random();
f32Bs.SetFileSystemId(rnd.Next());
f32Bs.SetVolumeLabel(label);
/* create FS info sector */
fsi = FsInfoSector.Create(f32Bs);
}
else
{
bs = new Fat16BootSector(device);
InitBootSector(bs);
var f16Bs = (Fat16BootSector)bs;
var rootDirEntries = RootDirectorySize(
device.GetSectorSize(), totalSectors);
f16Bs.SetRootDirEntryCount(rootDirEntries);
f16Bs.SetSectorsPerFat(SectorsPerFat(rootDirEntries, totalSectors));
if (label != null)
{
f16Bs.SetVolumeLabel(label);
}
fsi = null;
}
// bs.write();
if (fatType == FatType.BaseFat32)
{
var f32Bs = (Fat32BootSector)bs;
/* possibly writes the boot sector copy */
f32Bs.WriteCopy(device);
}
var fat = Fat.Create(bs, 0);
AbstractDirectory rootDirStore;
if (fatType == FatType.BaseFat32)
{
rootDirStore = ClusterChainDirectory.CreateRoot(fat);
fsi.SetFreeClusterCount(fat.GetFreeClusterCount());
fsi.SetLastAllocatedCluster(fat.GetLastAllocatedCluster());
fsi.Write();
}
else
{
rootDirStore = Fat16RootDirectory.Create((Fat16BootSector)bs);
}
var rootDir =
new FatLfnDirectory(rootDirStore, fat, false);
rootDir.Flush();
for (var i = 0; i < bs.GetNrFats(); i++)
{
fat.WriteCopy(FatUtils.GetFatOffset(bs, i));
}
bs.Write();
var fs = FatFileSystem.Read(device, false);
if (label != null)
{
fs.SetVolumeLabel(label);
}
fs.Flush();
return(fs);
}
