/// <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()); }
/// <summary> /// Flush all changed structures to the device. /// </summary> /// <exception cref="IOException">IOException on write error</exception> public override void Flush() { CheckClosed(); if (bs.IsDirty()) { bs.Write(); } for (var i = 0; i < bs.GetNrFats(); i++) { fat.WriteCopy(FatUtils.GetFatOffset(bs, i)); } rootDir.Flush(); if (fsiSector != null) { fsiSector.SetFreeClusterCount(fat.GetFreeClusterCount()); fsiSector.SetLastAllocatedCluster(fat.GetLastAllocatedCluster()); fsiSector.Write(); } }