Re: [PATCH 6.6.y] NFSD: simplify error paths in nfsd_svc()

[Greg KH <greg@kroah.com>]

On Sat, Aug 24, 2024 at 12:21:37PM -0400, cel@kernel.org wrote:
> From: NeilBrown <neilb@suse.de>
> 
> [ Upstream commit bf32075256e9dd9c6b736859e2c5813981339908 ]
> 
> The error paths in nfsd_svc() are needlessly complex and can result in a
> final call to svc_put() without nfsd_last_thread() being called.  This
> results in the listening sockets not being closed properly.
> 
> The per-netns setup provided by nfsd_startup_new() and removed by
> nfsd_shutdown_net() is needed precisely when there are running threads.
> So we don't need nfsd_up_before.  We don't need to know if it *was* up.
> We only need to know if any threads are left.  If none are, then we must
> call nfsd_shutdown_net().  But we don't need to do that explicitly as
> nfsd_last_thread() does that for us.
> 
> So simply call nfsd_last_thread() before the last svc_put() if there are
> no running threads.  That will always do the right thing.
> 
> Also discard:
>  pr_info("nfsd: last server has exited, flushing export cache\n");
> It may not be true if an attempt to start the first server failed, and
> it isn't particularly helpful and it simply reports normal behaviour.
> 
> Signed-off-by: NeilBrown <neilb@suse.de>
> Reviewed-by: Jeff Layton <jlayton@kernel.org>
> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
> ---
>  fs/nfsd/nfssvc.c | 14 ++++----------
>  1 file changed, 4 insertions(+), 10 deletions(-)
> 
> Reported-by: Li Lingfeng <lilingfeng3@huawei.com>
> Suggested-by: Li Lingfeng <lilingfeng3@huawei.com>
> Tested-by: Li Lingfeng <lilingfeng3@huawei.com>

Odd placement of these :)

Now queued up.

greg k-h