diff options
Diffstat (limited to 'pkg/sentry/syscalls')
| -rw-r--r-- | pkg/sentry/syscalls/linux/vfs2/splice.go | 35 |
1 files changed, 16 insertions, 19 deletions
diff --git a/pkg/sentry/syscalls/linux/vfs2/splice.go b/pkg/sentry/syscalls/linux/vfs2/splice.go index 75bfa2c79..192411393 100644 --- a/pkg/sentry/syscalls/linux/vfs2/splice.go +++ b/pkg/sentry/syscalls/linux/vfs2/splice.go @@ -131,18 +131,14 @@ func Splice(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscal case inIsPipe && outIsPipe: n, err = pipe.Splice(t, outPipeFD, inPipeFD, count) case inIsPipe: + n, err = inPipeFD.SpliceToNonPipe(t, outFile, outOffset, count) if outOffset != -1 { - n, err = outFile.PWrite(t, inPipeFD.IOSequence(count), outOffset, vfs.WriteOptions{}) outOffset += n - } else { - n, err = outFile.Write(t, inPipeFD.IOSequence(count), vfs.WriteOptions{}) } case outIsPipe: + n, err = outPipeFD.SpliceFromNonPipe(t, inFile, inOffset, count) if inOffset != -1 { - n, err = inFile.PRead(t, outPipeFD.IOSequence(count), inOffset, vfs.ReadOptions{}) inOffset += n - } else { - n, err = inFile.Read(t, outPipeFD.IOSequence(count), vfs.ReadOptions{}) } default: panic("not possible") @@ -341,17 +337,15 @@ func Sendfile(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sysc if outIsPipe { for n < count { var spliceN int64 - if offset != -1 { - spliceN, err = inFile.PRead(t, outPipeFD.IOSequence(count), offset, vfs.ReadOptions{}) - offset += spliceN - } else { - spliceN, err = inFile.Read(t, outPipeFD.IOSequence(count), vfs.ReadOptions{}) - } + spliceN, err = outPipeFD.SpliceFromNonPipe(t, inFile, offset, count) if spliceN == 0 && err == io.EOF { // We reached the end of the file. Eat the error and exit the loop. err = nil break } + if offset != -1 { + offset += spliceN + } n += spliceN if err == syserror.ErrWouldBlock && !nonBlock { err = dw.waitForBoth(t) @@ -371,19 +365,18 @@ func Sendfile(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sysc } else { readN, err = inFile.Read(t, usermem.BytesIOSequence(buf), vfs.ReadOptions{}) } - if readN == 0 && err == io.EOF { - // We reached the end of the file. Eat the error and exit the loop. - err = nil + if readN == 0 && err != nil { + if err == io.EOF { + // We reached the end of the file. Eat the error before exiting the loop. + err = nil + } break } n += readN - if err != nil { - break - } // Write all of the bytes that we read. This may need // multiple write calls to complete. - wbuf := buf[:n] + wbuf := buf[:readN] for len(wbuf) > 0 { var writeN int64 writeN, err = outFile.Write(t, usermem.BytesIOSequence(wbuf), vfs.WriteOptions{}) @@ -398,6 +391,10 @@ func Sendfile(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sysc notWritten := int64(len(wbuf)) n -= notWritten if offset != -1 { + // TODO(gvisor.dev/issue/3779): The inFile offset will be incorrect if we + // roll back, because it has already been advanced by the full amount. + // Merely seeking on inFile does not work, because there may be concurrent + // file operations. offset -= notWritten } break |