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| author | Joe Tsai <joetsai@digital-static.net> | 2017-09-20 23:20:28 -0700 |
|---|---|---|
| committer | Joe Tsai <thebrokentoaster@gmail.com> | 2017-09-21 17:49:35 +0000 |
| commit | fdecab6ef00be4a2e6247ebd962a281276b3f37d (patch) | |
| tree | ef3e1c63448e7c6f681f9d9b8969a02f599e324c | |
| parent | 97324858513735093a958a585cca6d5fc2780533 (diff) | |
| download | go-fdecab6ef00be4a2e6247ebd962a281276b3f37d.tar.xz | |
archive/tar: make check for hole detection support more liberal
On most Unix OSes, lseek reports EINVAL when lacking SEEK_HOLE support.
However, there are reports that ENOTTY is reported instead.
Rather than tracking down every possible errno that may be used to
represent "not supported", just treat any non-nil error as meaning
that there is no support. This is the same strategy taken by the
GNU and BSD tar tools.
Fixes #21958
Change-Id: Iae68afdc934042f52fa914fca45f0ca89220c383
Reviewed-on: https://go-review.googlesource.com/65191
Run-TryBot: Joe Tsai <thebrokentoaster@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
| -rw-r--r-- | src/archive/tar/sparse_unix.go | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/src/archive/tar/sparse_unix.go b/src/archive/tar/sparse_unix.go index 76b4c6cc2b..4bc3482858 100644 --- a/src/archive/tar/sparse_unix.go +++ b/src/archive/tar/sparse_unix.go @@ -23,8 +23,12 @@ func sparseDetectUnix(f *os.File) (sph sparseHoles, err error) { const seekHole = 4 // SEEK_HOLE from unistd.h // Check for seekData/seekHole support. - if _, err := f.Seek(0, seekHole); errno(err) == syscall.EINVAL { - return nil, nil // Either old kernel or FS does not support this + // Different OS and FS may differ in the exact errno that is returned when + // there is no support. Rather than special-casing every possible errno + // representing "not supported", just assume that a non-nil error means + // that seekData/seekHole is not supported. + if _, err := f.Seek(0, seekHole); err != nil { + return nil, nil } // Populate the SparseHoles. |