diff options
| -rw-r--r-- | internal/fusefrontend/file.go | 56 |
1 files changed, 29 insertions, 27 deletions
diff --git a/internal/fusefrontend/file.go b/internal/fusefrontend/file.go index b616d49..d637528 100644 --- a/internal/fusefrontend/file.go +++ b/internal/fusefrontend/file.go @@ -255,15 +255,14 @@ func (f *file) doWrite(data []byte, off int64) (uint32, fuse.Status) { } fileID := f.fileTableEntry.ID defer f.fileTableEntry.IDLock.RUnlock() - - var written uint32 + // Handle payload data status := fuse.OK dataBuf := bytes.NewBuffer(data) blocks := f.contentEnc.ExplodePlainRange(uint64(off), uint64(len(data))) - for _, b := range blocks { - + writeChain := make([][]byte, len(blocks)) + var numOutBytes int + for i, b := range blocks { blockData := dataBuf.Next(int(b.Length)) - // Incomplete block -> Read-Modify-Write if b.IsPartial() { // Read @@ -272,38 +271,41 @@ func (f *file) doWrite(data []byte, off int64) (uint32, fuse.Status) { oldData, status = f.doRead(o, f.contentEnc.PlainBS()) if status != fuse.OK { tlog.Warn.Printf("ino%d fh%d: RMW read failed: %s", f.devIno.ino, f.intFd(), status.String()) - return written, status + return 0, status } // Modify blockData = f.contentEnc.MergeBlocks(oldData, blockData, int(b.Skip)) tlog.Debug.Printf("len(oldData)=%d len(blockData)=%d", len(oldData), len(blockData)) } - // Encrypt - blockOffset := b.BlockCipherOff() blockData = f.contentEnc.EncryptBlock(blockData, b.BlockNo, fileID) tlog.Debug.Printf("ino%d: Writing %d bytes to block #%d", f.devIno.ino, uint64(len(blockData))-f.contentEnc.BlockOverhead(), b.BlockNo) - - // Prevent partially written (=corrupt) blocks by preallocating the space beforehand - err := syscallcompat.EnospcPrealloc(int(f.fd.Fd()), int64(blockOffset), int64(len(blockData))) - if err != nil { - tlog.Warn.Printf("ino%d fh%d: doWrite: prealloc failed: %s", f.devIno.ino, f.intFd(), err.Error()) - status = fuse.ToStatus(err) - break - } - - // Write - _, err = f.fd.WriteAt(blockData, int64(blockOffset)) - - if err != nil { - tlog.Warn.Printf("doWrite: Write failed: %s", err.Error()) - status = fuse.ToStatus(err) - break - } - written += uint32(b.Length) + // Store output data in the writeChain + writeChain[i] = blockData + numOutBytes += len(blockData) + } + // Concatenenate all elements in the writeChain into one contigous buffer + tmp := make([]byte, numOutBytes) + writeBuf := bytes.NewBuffer(tmp[:0]) + for _, w := range writeChain { + writeBuf.Write(w) + } + // Preallocate so we cannot run out of space in the middle of the write. + // This prevents partially written (=corrupt) blocks. + cOff := blocks[0].BlockCipherOff() + err := syscallcompat.EnospcPrealloc(int(f.fd.Fd()), int64(cOff), int64(writeBuf.Len())) + if err != nil { + tlog.Warn.Printf("ino%d fh%d: doWrite: prealloc failed: %s", f.devIno.ino, f.intFd(), err.Error()) + return 0, fuse.ToStatus(err) + } + // Write + _, err = f.fd.WriteAt(writeBuf.Bytes(), int64(cOff)) + if err != nil { + tlog.Warn.Printf("doWrite: Write failed: %s", err.Error()) + return 0, fuse.ToStatus(err) } - return written, status + return uint32(len(data)), fuse.OK } // isConsecutiveWrite returns true if the current write |