Пример #1
0
        public void RemoveRecord(FileRecordReference fileRef)
        {
            FileRecord record = GetRecord(fileRef.MftIndex, false);

            record.Reset();
            WriteRecord(record);

            _recordCache.Remove(fileRef.MftIndex);
            _bitmap.MarkAbsent(fileRef.MftIndex);
            _self.UpdateRecordInMft();
        }
Пример #2
0
        public FileRecord AllocateRecord(FileRecordFlags flags, bool isMft)
        {
            long index;

            if (isMft)
            {
                // Have to take a lot of care extending the MFT itself, to ensure we never end up unable to
                // bootstrap the file system via the MFT itself - hence why special records are reserved
                // for MFT's own MFT record overflow.
                for (int i = 15; i > 11; --i)
                {
                    FileRecord r = GetRecord(i, false);
                    if (r.BaseFile.SequenceNumber == 0)
                    {
                        r.Reset();
                        r.Flags |= FileRecordFlags.InUse;
                        WriteRecord(r);
                        return(r);
                    }
                }

                throw new IOException("MFT too fragmented - unable to allocate MFT overflow record");
            }
            else
            {
                index = _bitmap.AllocateFirstAvailable(FirstAvailableMftIndex);
            }

            if (index * _recordLength >= _recordStream.Length)
            {
                // Note: 64 is significant, since bitmap extends by 8 bytes (=64 bits) at a time.
                long newEndIndex = Utilities.RoundUp(index + 1, 64);
                _recordStream.SetLength(newEndIndex * _recordLength);
                for (long i = index; i < newEndIndex; ++i)
                {
                    FileRecord record = new FileRecord(_bytesPerSector, _recordLength, (uint)i);
                    WriteRecord(record);
                }
            }

            FileRecord newRecord = GetRecord(index, true);

            newRecord.ReInitialize(_bytesPerSector, _recordLength, (uint)index);

            _recordCache[index] = newRecord;

            newRecord.Flags = FileRecordFlags.InUse | flags;

            WriteRecord(newRecord);
            _self.UpdateRecordInMft();

            return(newRecord);
        }