Re: [PATCH v7 12/14] NFSD: Refactor find_file()

From: Jeff Layton <jlayton@kernel.org>
To: Chuck Lever <chuck.lever@oracle.com>, linux-nfs@vger.kernel.org
Cc: neilb@suse.de
Subject: Re: [PATCH v7 12/14] NFSD: Refactor find_file()
Date: Mon, 31 Oct 2022 12:50:35 -0400	[thread overview]
Message-ID: <ba83a0ca28a9ee572576a467eb27baa76745c730.camel@kernel.org> (raw)
In-Reply-To: <166696846760.106044.18334584948493999552.stgit@klimt.1015granger.net>

On Fri, 2022-10-28 at 10:47 -0400, Chuck Lever wrote:
> find_file() is now the only caller of find_file_locked(), so just
> fold these two together.
> 
> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
> Reviewed-by: NeilBrown <neilb@suse.de>
> ---
>  fs/nfsd/nfs4state.c |   36 +++++++++++++++---------------------
>  1 file changed, 15 insertions(+), 21 deletions(-)
> 
> diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
> index b1988a46fb9b..2b694d693be5 100644
> --- a/fs/nfsd/nfs4state.c
> +++ b/fs/nfsd/nfs4state.c
> @@ -4667,31 +4667,24 @@ move_to_close_lru(struct nfs4_ol_stateid *s, struct net *net)
>  		nfs4_put_stid(&last->st_stid);
>  }
>  
> -/* search file_hashtbl[] for file */
> -static struct nfs4_file *
> -find_file_locked(const struct svc_fh *fh, unsigned int hashval)
> +static noinline_for_stack struct nfs4_file *
> +nfsd4_file_hash_lookup(const struct svc_fh *fhp)
>  {
> -	struct nfs4_file *fp;
> +	unsigned int hashval = file_hashval(fhp);
> +	struct nfs4_file *fi;
>  
> -	hlist_for_each_entry_rcu(fp, &file_hashtbl[hashval], fi_hash,
> -				lockdep_is_held(&state_lock)) {
> -		if (fh_match(&fp->fi_fhandle, &fh->fh_handle)) {
> -			if (refcount_inc_not_zero(&fp->fi_ref))
> -				return fp;
> +	rcu_read_lock();
> +	hlist_for_each_entry_rcu(fi, &file_hashtbl[hashval], fi_hash,
> +				 lockdep_is_held(&state_lock)) {
> +		if (fh_match(&fi->fi_fhandle, &fhp->fh_handle)) {
> +			if (refcount_inc_not_zero(&fi->fi_ref)) {
> +				rcu_read_unlock();
> +				return fi;
> +			}
>  		}
>  	}
> -	return NULL;
> -}
> -
> -static struct nfs4_file * find_file(struct svc_fh *fh)
> -{
> -	struct nfs4_file *fp;
> -	unsigned int hashval = file_hashval(fh);
> -
> -	rcu_read_lock();
> -	fp = find_file_locked(fh, hashval);
>  	rcu_read_unlock();
> -	return fp;
> +	return NULL;
>  }
>  
>  /*
> @@ -4742,9 +4735,10 @@ nfs4_share_conflict(struct svc_fh *current_fh, unsigned int deny_type)
>  	struct nfs4_file *fp;
>  	__be32 ret = nfs_ok;
>  
> -	fp = find_file(current_fh);
> +	fp = nfsd4_file_hash_lookup(current_fh);
>  	if (!fp)
>  		return ret;
> +
>  	/* Check for conflicting share reservations */
>  	spin_lock(&fp->fi_lock);
>  	if (fp->fi_share_deny & deny_type)
> 
> 

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