should copy_file_range(2) have a non-Linux flag?

From: Rick Macklem <>
Date: Sat, 4 Sep 2021 15:08:59 +0000

I just proposed a patch for VOP_COPY_FILE_RANGE(9)
that adds a kernel only flag to specify "return after 1second
with a partial copy". I'd like to use it for the NFSv4.2 server,
so that the RPC replies in a reasonable time frame.

The question that came up is...
"should this flag be visible to userland?"

The only argument I can think of against doing this is
that it makes the syscall non-Linux compatible.
(Also, the NFS server requirement seems a bit of an oddball
 and I'm not sure an application would want this capability?)

Do you think this flag should be exposed to userland (ie the syscall)?


Received on Sat Sep 04 2021 - 15:08:59 UTC

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