Re: [PATCH 3/4] lockd: eliminate duplicate nlmsvc_lookup_host call from nlmsvc_lock

["J. Bruce Fields" <bfields@fieldses.org>]

On Tue, Jul 15, 2008 at 02:48:12PM -0400, J. Bruce Fields wrote:
> From: Jeff Layton <jlayton@redhat.com>
> 
> nlmsvc_lock calls nlmsvc_lookup_host to find a nlm_host struct. The
> callers of this function, however, call nlmsvc_retrieve_args or
> nlm4svc_retrieve_args, which also return a nlm_host struct.
> 
> Change nlmsvc_lock to take a host arg instead of calling
> nlmsvc_lookup_host itself and change the callers to pass a pointer to
> the nlm_host they've already found.
> 
> Since nlmsvc_testlock() now just uses the caller's reference, we no
> longer need to get or release it.
> 
> Signed-off-by: Jeff Layton <jlayton@redhat.com>
> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
> ---
>  fs/lockd/svc4proc.c         |    2 +-
>  fs/lockd/svclock.c          |   12 +++---------
>  fs/lockd/svcproc.c          |    2 +-
>  include/linux/lockd/lockd.h |    3 ++-
>  4 files changed, 7 insertions(+), 12 deletions(-)
> 
> diff --git a/fs/lockd/svc4proc.c b/fs/lockd/svc4proc.c
> index 8cfb9da..189b2ce 100644
> --- a/fs/lockd/svc4proc.c
> +++ b/fs/lockd/svc4proc.c
> @@ -145,7 +145,7 @@ nlm4svc_proc_lock(struct svc_rqst *rqstp, struct nlm_args *argp,
>  #endif
>  
>  	/* Now try to lock the file */
> -	resp->status = nlmsvc_lock(rqstp, file, &argp->lock,
> +	resp->status = nlmsvc_lock(rqstp, file, host, &argp->lock,
>  					argp->block, &argp->cookie);
>  	if (resp->status == nlm_drop_reply)
>  		rc = rpc_drop_reply;
> diff --git a/fs/lockd/svclock.c b/fs/lockd/svclock.c
> index f40afb3..a6d3ed0 100644
> --- a/fs/lockd/svclock.c
> +++ b/fs/lockd/svclock.c
> @@ -358,10 +358,10 @@ nlmsvc_defer_lock_rqst(struct svc_rqst *rqstp, struct nlm_block *block)
>   */
>  __be32
>  nlmsvc_lock(struct svc_rqst *rqstp, struct nlm_file *file,
> -			struct nlm_lock *lock, int wait, struct nlm_cookie *cookie)
> +	    struct nlm_host *host, struct nlm_lock *lock, int wait,
> +	    struct nlm_cookie *cookie)
>  {
>  	struct nlm_block	*block = NULL;
> -	struct nlm_host		*host;
>  	int			error;
>  	__be32			ret;
>  
> @@ -373,11 +373,6 @@ nlmsvc_lock(struct svc_rqst *rqstp, struct nlm_file *file,
>  				(long long)lock->fl.fl_end,
>  				wait);
>  
> -	/* Create host handle for callback */
> -	host = nlmsvc_lookup_host(rqstp, lock->caller, lock->len);
> -	if (host == NULL)
> -		return nlm_lck_denied_nolocks;
> -
>  	/* Lock file against concurrent access */
>  	mutex_lock(&file->f_mutex);
>  	/* Get existing block (in case client is busy-waiting)
> @@ -450,7 +445,6 @@ nlmsvc_lock(struct svc_rqst *rqstp, struct nlm_file *file,
>  out:
>  	mutex_unlock(&file->f_mutex);
>  	nlmsvc_release_block(block);
> -	nlm_release_host(host);
>  	dprintk("lockd: nlmsvc_lock returned %u\n", ret);
>  	return ret;
>  }
> @@ -483,7 +477,7 @@ nlmsvc_testlock(struct svc_rqst *rqstp, struct nlm_file *file,
>  		if (conf == NULL)
>  			return nlm_granted;
>  		nlm_get_host(host);
> -		block = nlmsvc_create_block(rqstp, host, file, lock, cookie);
> +		block = nlmsvc_create_block(rqstp, file, lock, cookie);
>  		if (block == NULL) {
>  			kfree(conf);
>  			return nlm_granted;

Oh, jeez, except ignore that chunk!  Version that actually compiles
pushed to

	git://linux-nfs.org/~bfields/linux.git

--b.

> diff --git a/fs/lockd/svcproc.c b/fs/lockd/svcproc.c
> index e099f58..82dc908 100644
> --- a/fs/lockd/svcproc.c
> +++ b/fs/lockd/svcproc.c
> @@ -175,7 +175,7 @@ nlmsvc_proc_lock(struct svc_rqst *rqstp, struct nlm_args *argp,
>  #endif
>  
>  	/* Now try to lock the file */
> -	resp->status = cast_status(nlmsvc_lock(rqstp, file, &argp->lock,
> +	resp->status = cast_status(nlmsvc_lock(rqstp, file, host, &argp->lock,
>  					       argp->block, &argp->cookie));
>  	if (resp->status == nlm_drop_reply)
>  		rc = rpc_drop_reply;
> diff --git a/include/linux/lockd/lockd.h b/include/linux/lockd/lockd.h
> index b279670..f81f9dd 100644
> --- a/include/linux/lockd/lockd.h
> +++ b/include/linux/lockd/lockd.h
> @@ -200,7 +200,8 @@ typedef int	  (*nlm_host_match_fn_t)(void *cur, struct nlm_host *ref);
>   * Server-side lock handling
>   */
>  __be32		  nlmsvc_lock(struct svc_rqst *, struct nlm_file *,
> -					struct nlm_lock *, int, struct nlm_cookie *);
> +			      struct nlm_host *, struct nlm_lock *, int,
> +			      struct nlm_cookie *);
>  __be32		  nlmsvc_unlock(struct nlm_file *, struct nlm_lock *);
>  __be32		  nlmsvc_testlock(struct svc_rqst *, struct nlm_file *,
>  			struct nlm_host *, struct nlm_lock *,
> -- 
> 1.5.5.rc1
>