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| author | Andy Pan <panjf2000@gmail.com> | 2023-02-27 12:47:39 +0800 |
|---|---|---|
| committer | Gopher Robot <gobot@golang.org> | 2023-02-27 22:20:11 +0000 |
| commit | 08a68b73a4843dfe8c4896cace3242b895342511 (patch) | |
| tree | d1b93d132fc423b080481e66a90727d6dff69066 /src/os | |
| parent | 676794f73e6ca8fbd7ec14f4185625efda4e2ca8 (diff) | |
| download | go-git-08a68b73a4843dfe8c4896cace3242b895342511.tar.gz | |
os: skip zero-copy attempts with copy_file_range(2)/splice(2) for target files with O_APPEND flag
Change-Id: I6cccac9295ab4a9bf7f7a33382a34f31b1c4a000
Reviewed-on: https://go-review.googlesource.com/c/go/+/471496
Auto-Submit: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>
Reviewed-by: Bryan Mills <bcmills@google.com>
Run-TryBot: Andy Pan <panjf2000@gmail.com>
Diffstat (limited to 'src/os')
| -rw-r--r-- | src/os/readfrom_linux.go | 15 |
1 files changed, 9 insertions, 6 deletions
diff --git a/src/os/readfrom_linux.go b/src/os/readfrom_linux.go index 2a81b7abfe..514d873ece 100644 --- a/src/os/readfrom_linux.go +++ b/src/os/readfrom_linux.go @@ -16,6 +16,15 @@ var ( ) func (f *File) readFrom(r io.Reader) (written int64, handled bool, err error) { + // Neither copy_file_range(2) nor splice(2) supports destinations opened with + // O_APPEND, so don't bother to try zero-copy with these system calls. + // + // Visit https://man7.org/linux/man-pages/man2/copy_file_range.2.html#ERRORS and + // https://man7.org/linux/man-pages/man2/splice.2.html#ERRORS for details. + if f.appendMode { + return 0, false, nil + } + written, handled, err = f.copyFileRange(r) if handled { return @@ -74,12 +83,6 @@ func getPollFD(r io.Reader) *poll.FD { } func (f *File) copyFileRange(r io.Reader) (written int64, handled bool, err error) { - // copy_file_range(2) does not support destinations opened with - // O_APPEND, so don't even try. - if f.appendMode { - return 0, false, nil - } - var ( remain int64 lr *io.LimitedReader |