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

From: Crest <>
Date: Mon, 6 Sep 2021 15:21:57 +0200
On 04.09.21 17:08, Rick Macklem wrote:
> Hi,
> 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)?
I can see usecases for this flag:

* NFS Ganesha

* Report progress during large file copies e.g. in a git annex special 
Received on Mon Sep 06 2021 - 13:21:57 UTC

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