From b0cc02e8c2bdba5401838d9d70a859191af9bfa5 Mon Sep 17 00:00:00 2001 From: Tobias Klauser Date: Wed, 19 Aug 2020 16:54:36 +0200 Subject: [PATCH] internal/poll: treat copy_file_range EPERM as not-handled Fixes #40893 Change-Id: I938ea4796c1e1d1e136117fe78b06ad6da8e40de Reviewed-on: https://go-review.googlesource.com/c/go/+/249257 Run-TryBot: Tobias Klauser TryBot-Result: Gobot Gobot Reviewed-by: Antonio Troina Reviewed-by: Ian Lance Taylor --- src/internal/poll/copy_file_range_linux.go | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/src/internal/poll/copy_file_range_linux.go b/src/internal/poll/copy_file_range_linux.go index 7e67125818..09de299ff7 100644 --- a/src/internal/poll/copy_file_range_linux.go +++ b/src/internal/poll/copy_file_range_linux.go @@ -41,7 +41,7 @@ func CopyFileRange(dst, src *FD, remain int64) (written int64, handled bool, err // use copy_file_range(2) again. atomic.StoreInt32(©FileRangeSupported, 0) return 0, false, nil - case syscall.EXDEV, syscall.EINVAL, syscall.EOPNOTSUPP: + case syscall.EXDEV, syscall.EINVAL, syscall.EOPNOTSUPP, syscall.EPERM: // Prior to Linux 5.3, it was not possible to // copy_file_range across file systems. Similarly to // the ENOSYS case above, if we see EXDEV, we have @@ -55,6 +55,11 @@ func CopyFileRange(dst, src *FD, remain int64) (written int64, handled bool, err // // If the file is on NFS, we can see EOPNOTSUPP. // See issue #40731. + // + // If the process is running inside a Docker container, + // we might see EPERM instead of ENOSYS. See issue + // #40893. Since EPERM might also be a legitimate error, + // don't mark copy_file_range(2) as unsupported. return 0, false, nil case nil: if n == 0 { -- 2.50.0