Re: [PATCH 1/2] nfsd: avoid ref leak in nfsd_open_local_fh()

[Mike Snitzer <snitzer@kernel.org>]

On Fri, Jul 18, 2025 at 11:26:14AM +1000, NeilBrown wrote:
> If two calls to nfsd_open_local_fh() race and both successfully call
> nfsd_file_acquire_local(), they will both get an extra reference to the
> net to accompany the file reference stored in *pnf.
> 
> One of them will fail to store (using xchg()) the file reference in
> *pnf and will drop that reference but WONT drop the accompanying
> reference to the net.  This leak means that when the nfs server is shut
> down it will hang in nfsd_shutdown_net() waiting for
> &nn->nfsd_net_free_done.
> 
> This patch adds the missing nfsd_net_put().
> 
> Reported-by: Mike Snitzer <snitzer@kernel.org>
> Fixes: e6f7e1487ab5 ("nfs_localio: simplify interface to nfsd for getting nfsd_file")
> Signed-off-by: NeilBrown <neil@brown.name>

Tested-by: Mike Snitzer <snitzer@kernel.org>
Reviewed-by: Mike Snitzer <snitzer@kernel.org>

Looks really solid now, thanks!

Mike