Re: [PATCH 0/3] nfsd update mtime/ctime on CLONE/COPY with delegated attritutes

[Jeff Layton <jlayton@kernel.org>]

On Tue, 2026-04-07 at 19:50 -0400, Olga Kornievskaia wrote:
> generic/407 is failing in presence of delegated attributes and this patch series 
> explores the solution where the CLONE compound returns updated mtime/ctime
> in the GETATTR op in the compound.
> 
> It's broken into several pieces as I consider asynchronous copy update the trickest
> because the copy thread currently have no dentry to call notify_change() on. And
> if we are going to keep a copy of it while the copy is running we probably need to
> take a reference on it (which I attempt to do).
> 
> An outstanding question I have is whether or not a CLONE/COPY operation is supposed to
> also update the atime on the source file? But also atime for the dest file as well?
> I'm updating both ctime and mtime for the destination (though Jeff only suggested
> mtime and perhaps I'm missing something in updating ctime as well but I thought it 
> was appropriate). 
> 

CLONE/COPY aren't defined by POSIX so I'm not sure we have clear
guidance about the atime on the source or destination. Within Linux,
COPY is implemented using reads and writes though, so I'd expect that
the source file has its atime updated, and the destination gets a new
c/time. I don't see why it'd need to read the destination file though,
so I wouldn't expect an atime update there.

> COPY was tested by modifying the linux client to send a GETATTR in the COPY compound.
> Whether or not the client should add the GETATTR to the COPY compound is yet another
> question I have but I guess it would be for Trond.
> 
> Olga Kornievskaia (3):
>   nfsd: update mtime/ctime on CLONE in presense of delegated attributes
>   nfsd: update mtime/ctime on synchronous COPY with delegated attributes
>   nfsd: update mtime/ctime on asynchronous COPY with delegated
>     attributes
> 
>  fs/nfsd/nfs4proc.c | 38 +++++++++++++++++++++++++++++++++++++-
>  fs/nfsd/xdr4.h     |  1 +
>  2 files changed, 38 insertions(+), 1 deletion(-)

-- 
Jeff Layton <jlayton@kernel.org>