Re: [PATCH v7 10/14] NFSD: Add a nfsd4_file_hash_remove() helper

[Jeff Layton <jlayton@kernel.org>]

On Fri, 2022-10-28 at 10:47 -0400, Chuck Lever wrote:
> Refactor to relocate hash deletion operation to a helper function
> that is close to most other nfs4_file data structure operations.
> 
> The "noinline" annotation will become useful in a moment when the
> hlist_del_rcu() is replaced with a more complex rhash remove
> operation. It also guarantees that hash remove operations can be
> traced with "-p function -l remove_nfs4_file_locked".
> 
> This also simplifies the organization of forward declarations: the
> to-be-added rhashtable and its param structure will be defined
> /after/ put_nfs4_file().
> 
> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
> Reviewed-by: NeilBrown <neilb@suse.de>
> ---
>  fs/nfsd/nfs4state.c |    8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
> index 3132e4844ef8..504455cb80e9 100644
> --- a/fs/nfsd/nfs4state.c
> +++ b/fs/nfsd/nfs4state.c
> @@ -84,6 +84,7 @@ static bool check_for_locks(struct nfs4_file *fp, struct nfs4_lockowner *lowner)
>  static void nfs4_free_ol_stateid(struct nfs4_stid *stid);
>  void nfsd4_end_grace(struct nfsd_net *nn);
>  static void _free_cpntf_state_locked(struct nfsd_net *nn, struct nfs4_cpntf_state *cps);
> +static void nfsd4_file_hash_remove(struct nfs4_file *fi);
>  
>  /* Locking: */
>  
> @@ -591,7 +592,7 @@ put_nfs4_file(struct nfs4_file *fi)
>  	might_lock(&state_lock);
>  
>  	if (refcount_dec_and_lock(&fi->fi_ref, &state_lock)) {
> -		hlist_del_rcu(&fi->fi_hash);
> +		nfsd4_file_hash_remove(fi);
>  		spin_unlock(&state_lock);
>  		WARN_ON_ONCE(!list_empty(&fi->fi_clnt_odstate));
>  		WARN_ON_ONCE(!list_empty(&fi->fi_delegations));
> @@ -4734,6 +4735,11 @@ find_or_add_file(struct nfs4_file *new, struct svc_fh *fh)
>  	return insert_file(new, fh, hashval);
>  }
>  
> +static noinline_for_stack void nfsd4_file_hash_remove(struct nfs4_file *fi)
> +{
> +	hlist_del_rcu(&fi->fi_hash);
> +}
> +
>  /*
>   * Called to check deny when READ with all zero stateid or
>   * WRITE with all zero or all one stateid
> 
> 

Reviewed-by: Jeff Layton <jlayton@kernel.org>