Re: [BUG] NFSv4.2: futimens() returns success without sending SETATTR

On 2026-07-24 at 21:07 (-0700), Michael Yang wrote:
> I've found this report (https://bugzilla.proxmox.com/show_bug.cgi?id=7621) where the problem manifested as early as 6.17.x and 7.0.x (but is not present on the 6.12.88 LTS kernel), and is isolated to NFSv4.2.
> 
> I can confirm with client mount option vers=4.1, the timestamps update successfully on the server.
> 

I'm also seeing this same issue on Fedora 44 with kernel 7.0.8 and 
nfs-utils 2.8.7.

In my case, extracting files locally preserved the timestamps correctly, 
but copying them to an NFSv4.2 mount with rsync -a only showed the 
preserved mtimes on the client. The server-side backing inode did not 
update, and the client view later reverted to the server timestamp.

I also saw the same behavior with touch -d.

I have not tried forcing vers=4.1 yet, but disabling NFS delegations on 
the server with fs.leases-enable=0 made the problem go away for me.


Thanks

-- 
Matt