Re: [PATCH v14 13/25] SUNRPC: replace program list with program array

[Jeff Layton <jlayton@kernel.org>]

On Wed, 2024-08-28 at 21:04 -0400, Mike Snitzer wrote:
> From: NeilBrown <neil@brown.name>
> 
> A service created with svc_create_pooled() can be given a linked list of
> programs and all of these will be served.
> 
> Using a linked list makes it cumbersome when there are several programs
> that can be optionally selected with CONFIG settings.
> 
> After this patch is applied, API consumers must use only
> svc_create_pooled() when creating an RPC service that listens for more
> than one RPC program.
> 
> Acked-by: Chuck Lever <chuck.lever@oracle.com>
> Signed-off-by: NeilBrown <neil@brown.name>
> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
> ---
>  fs/nfsd/nfsctl.c           |  2 +-
>  fs/nfsd/nfsd.h             |  2 +-
>  fs/nfsd/nfssvc.c           | 38 ++++++++++-----------
>  include/linux/sunrpc/svc.h |  7 ++--
>  net/sunrpc/svc.c           | 68 ++++++++++++++++++++++----------------
>  net/sunrpc/svc_xprt.c      |  2 +-
>  net/sunrpc/svcauth_unix.c  |  3 +-
>  7 files changed, 67 insertions(+), 55 deletions(-)
> 
> diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
> index 1c9e5b4bcb0a..64c1b4d649bc 100644
> --- a/fs/nfsd/nfsctl.c
> +++ b/fs/nfsd/nfsctl.c
> @@ -2246,7 +2246,7 @@ static __net_init int nfsd_net_init(struct net *net)
>  	if (retval)
>  		goto out_repcache_error;
>  	memset(&nn->nfsd_svcstats, 0, sizeof(nn->nfsd_svcstats));
> -	nn->nfsd_svcstats.program = &nfsd_program;
> +	nn->nfsd_svcstats.program = &nfsd_programs[0];
>  	for (i = 0; i < sizeof(nn->nfsd_versions); i++)
>  		nn->nfsd_versions[i] = nfsd_support_version(i);
>  	for (i = 0; i < sizeof(nn->nfsd4_minorversions); i++)
> diff --git a/fs/nfsd/nfsd.h b/fs/nfsd/nfsd.h
> index 4ccbf014a2c7..b0d3e82d6dcd 100644
> --- a/fs/nfsd/nfsd.h
> +++ b/fs/nfsd/nfsd.h
> @@ -85,7 +85,7 @@ struct nfsd_genl_rqstp {
>  	u32			rq_opnum[NFSD_MAX_OPS_PER_COMPOUND];
>  };
>  
> -extern struct svc_program	nfsd_program;
> +extern struct svc_program	nfsd_programs[];
>  extern const struct svc_version	nfsd_version2, nfsd_version3, nfsd_version4;
>  extern struct mutex		nfsd_mutex;
>  extern spinlock_t		nfsd_drc_lock;
> diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c
> index e43d440f9f0a..c639fbe4d8c2 100644
> --- a/fs/nfsd/nfssvc.c
> +++ b/fs/nfsd/nfssvc.c
> @@ -35,7 +35,6 @@
>  #define NFSDDBG_FACILITY	NFSDDBG_SVC
>  
>  atomic_t			nfsd_th_cnt = ATOMIC_INIT(0);
> -extern struct svc_program	nfsd_program;
>  static int			nfsd(void *vrqstp);
>  #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
>  static int			nfsd_acl_rpcbind_set(struct net *,
> @@ -90,20 +89,9 @@ static const struct svc_version *nfsd_acl_version[] = {
>  # endif
>  };
>  
> -#define NFSD_ACL_MINVERS            2
> +#define NFSD_ACL_MINVERS	2
>  #define NFSD_ACL_NRVERS		ARRAY_SIZE(nfsd_acl_version)
>  
> -static struct svc_program	nfsd_acl_program = {
> -	.pg_prog		= NFS_ACL_PROGRAM,
> -	.pg_nvers		= NFSD_ACL_NRVERS,
> -	.pg_vers		= nfsd_acl_version,
> -	.pg_name		= "nfsacl",
> -	.pg_class		= "nfsd",
> -	.pg_authenticate	= &svc_set_client,
> -	.pg_init_request	= nfsd_acl_init_request,
> -	.pg_rpcbind_set		= nfsd_acl_rpcbind_set,
> -};
> -
>  #endif /* defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) */
>  
>  static const struct svc_version *nfsd_version[NFSD_MAXVERS+1] = {
> @@ -116,18 +104,29 @@ static const struct svc_version *nfsd_version[NFSD_MAXVERS+1] = {
>  #endif
>  };
>  
> -struct svc_program		nfsd_program = {
> -#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
> -	.pg_next		= &nfsd_acl_program,
> -#endif
> +struct svc_program		nfsd_programs[] = {
> +	{
>  	.pg_prog		= NFS_PROGRAM,		/* program number */
>  	.pg_nvers		= NFSD_MAXVERS+1,	/* nr of entries in nfsd_version */
>  	.pg_vers		= nfsd_version,		/* version table */
>  	.pg_name		= "nfsd",		/* program name */
>  	.pg_class		= "nfsd",		/* authentication class */
> -	.pg_authenticate	= &svc_set_client,	/* export authentication */
> +	.pg_authenticate	= svc_set_client,	/* export authentication */
>  	.pg_init_request	= nfsd_init_request,
>  	.pg_rpcbind_set		= nfsd_rpcbind_set,
> +	},
> +#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
> +	{
> +	.pg_prog		= NFS_ACL_PROGRAM,
> +	.pg_nvers		= NFSD_ACL_NRVERS,
> +	.pg_vers		= nfsd_acl_version,
> +	.pg_name		= "nfsacl",
> +	.pg_class		= "nfsd",
> +	.pg_authenticate	= svc_set_client,
> +	.pg_init_request	= nfsd_acl_init_request,
> +	.pg_rpcbind_set		= nfsd_acl_rpcbind_set,
> +	},
> +#endif /* defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) */
>  };
>  
>  bool nfsd_support_version(int vers)
> @@ -637,7 +636,8 @@ int nfsd_create_serv(struct net *net)
>  	if (nfsd_max_blksize == 0)
>  		nfsd_max_blksize = nfsd_get_default_max_blksize();
>  	nfsd_reset_versions(nn);
> -	serv = svc_create_pooled(&nfsd_program, &nn->nfsd_svcstats,
> +	serv = svc_create_pooled(nfsd_programs, ARRAY_SIZE(nfsd_programs),
> +				 &nn->nfsd_svcstats,
>  				 nfsd_max_blksize, nfsd);
>  	if (serv == NULL)
>  		return -ENOMEM;
> diff --git a/include/linux/sunrpc/svc.h b/include/linux/sunrpc/svc.h
> index 437672bcaa22..c7ad2fb2a155 100644
> --- a/include/linux/sunrpc/svc.h
> +++ b/include/linux/sunrpc/svc.h
> @@ -67,9 +67,10 @@ enum {
>   * We currently do not support more than one RPC program per daemon.
>   */
>  struct svc_serv {
> -	struct svc_program *	sv_program;	/* RPC program */
> +	struct svc_program *	sv_programs;	/* RPC programs */
>  	struct svc_stat *	sv_stats;	/* RPC statistics */
>  	spinlock_t		sv_lock;
> +	unsigned int		sv_nprogs;	/* Number of sv_programs */
>  	unsigned int		sv_nrthreads;	/* # of server threads */
>  	unsigned int		sv_maxconn;	/* max connections allowed or
>  						 * '0' causing max to be based
> @@ -357,10 +358,9 @@ struct svc_process_info {
>  };
>  
>  /*
> - * List of RPC programs on the same transport endpoint
> + * RPC program - an array of these can use the same transport endpoint
>   */
>  struct svc_program {
> -	struct svc_program *	pg_next;	/* other programs (same xprt) */
>  	u32			pg_prog;	/* program number */
>  	unsigned int		pg_lovers;	/* lowest version */
>  	unsigned int		pg_hivers;	/* highest version */
> @@ -438,6 +438,7 @@ bool		   svc_rqst_replace_page(struct svc_rqst *rqstp,
>  void		   svc_rqst_release_pages(struct svc_rqst *rqstp);
>  void		   svc_exit_thread(struct svc_rqst *);
>  struct svc_serv *  svc_create_pooled(struct svc_program *prog,
> +				     unsigned int nprog,
>  				     struct svc_stat *stats,
>  				     unsigned int bufsize,
>  				     int (*threadfn)(void *data));
> diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c
> index ff6f3e35b36d..b33386d249c2 100644
> --- a/net/sunrpc/svc.c
> +++ b/net/sunrpc/svc.c
> @@ -440,10 +440,11 @@ EXPORT_SYMBOL_GPL(svc_rpcb_cleanup);
>  
>  static int svc_uses_rpcbind(struct svc_serv *serv)
>  {
> -	struct svc_program	*progp;
> -	unsigned int		i;
> +	unsigned int		p, i;
> +
> +	for (p = 0; p < serv->sv_nprogs; p++) {
> +		struct svc_program *progp = &serv->sv_programs[p];
>  
> -	for (progp = serv->sv_program; progp; progp = progp->pg_next) {
>  		for (i = 0; i < progp->pg_nvers; i++) {
>  			if (progp->pg_vers[i] == NULL)
>  				continue;
> @@ -480,7 +481,7 @@ __svc_init_bc(struct svc_serv *serv)
>   * Create an RPC service
>   */
>  static struct svc_serv *
> -__svc_create(struct svc_program *prog, struct svc_stat *stats,
> +__svc_create(struct svc_program *prog, int nprogs, struct svc_stat *stats,
>  	     unsigned int bufsize, int npools, int (*threadfn)(void *data))
>  {
>  	struct svc_serv	*serv;
> @@ -491,7 +492,8 @@ __svc_create(struct svc_program *prog, struct svc_stat *stats,
>  	if (!(serv = kzalloc(sizeof(*serv), GFP_KERNEL)))
>  		return NULL;
>  	serv->sv_name      = prog->pg_name;
> -	serv->sv_program   = prog;
> +	serv->sv_programs  = prog;
> +	serv->sv_nprogs    = nprogs;
>  	serv->sv_stats     = stats;
>  	if (bufsize > RPCSVC_MAXPAYLOAD)
>  		bufsize = RPCSVC_MAXPAYLOAD;
> @@ -499,17 +501,18 @@ __svc_create(struct svc_program *prog, struct svc_stat *stats,
>  	serv->sv_max_mesg  = roundup(serv->sv_max_payload + PAGE_SIZE, PAGE_SIZE);
>  	serv->sv_threadfn = threadfn;
>  	xdrsize = 0;
> -	while (prog) {
> -		prog->pg_lovers = prog->pg_nvers-1;
> -		for (vers=0; vers<prog->pg_nvers ; vers++)
> -			if (prog->pg_vers[vers]) {
> -				prog->pg_hivers = vers;
> -				if (prog->pg_lovers > vers)
> -					prog->pg_lovers = vers;
> -				if (prog->pg_vers[vers]->vs_xdrsize > xdrsize)
> -					xdrsize = prog->pg_vers[vers]->vs_xdrsize;
> +	for (i = 0; i < nprogs; i++) {
> +		struct svc_program *progp = &prog[i];
> +
> +		progp->pg_lovers = progp->pg_nvers-1;
> +		for (vers = 0; vers < progp->pg_nvers ; vers++)
> +			if (progp->pg_vers[vers]) {
> +				progp->pg_hivers = vers;
> +				if (progp->pg_lovers > vers)
> +					progp->pg_lovers = vers;
> +				if (progp->pg_vers[vers]->vs_xdrsize > xdrsize)
> +					xdrsize = progp->pg_vers[vers]->vs_xdrsize;
>  			}
> -		prog = prog->pg_next;
>  	}
>  	serv->sv_xdrsize   = xdrsize;
>  	INIT_LIST_HEAD(&serv->sv_tempsocks);
> @@ -558,13 +561,14 @@ __svc_create(struct svc_program *prog, struct svc_stat *stats,
>  struct svc_serv *svc_create(struct svc_program *prog, unsigned int bufsize,
>  			    int (*threadfn)(void *data))
>  {
> -	return __svc_create(prog, NULL, bufsize, 1, threadfn);
> +	return __svc_create(prog, 1, NULL, bufsize, 1, threadfn);
>  }
>  EXPORT_SYMBOL_GPL(svc_create);
>  
>  /**
>   * svc_create_pooled - Create an RPC service with pooled threads
> - * @prog: the RPC program the new service will handle
> + * @prog:  Array of RPC programs the new service will handle
> + * @nprogs: Number of programs in the array
>   * @stats: the stats struct if desired
>   * @bufsize: maximum message size for @prog
>   * @threadfn: a function to service RPC requests for @prog
> @@ -572,6 +576,7 @@ EXPORT_SYMBOL_GPL(svc_create);
>   * Returns an instantiated struct svc_serv object or NULL.
>   */
>  struct svc_serv *svc_create_pooled(struct svc_program *prog,
> +				   unsigned int nprogs,
>  				   struct svc_stat *stats,
>  				   unsigned int bufsize,
>  				   int (*threadfn)(void *data))
> @@ -579,7 +584,7 @@ struct svc_serv *svc_create_pooled(struct svc_program *prog,
>  	struct svc_serv *serv;
>  	unsigned int npools = svc_pool_map_get();
>  
> -	serv = __svc_create(prog, stats, bufsize, npools, threadfn);
> +	serv = __svc_create(prog, nprogs, stats, bufsize, npools, threadfn);
>  	if (!serv)
>  		goto out_err;
>  	serv->sv_is_pooled = true;
> @@ -602,16 +607,16 @@ svc_destroy(struct svc_serv **servp)
>  
>  	*servp = NULL;
>  
> -	dprintk("svc: svc_destroy(%s)\n", serv->sv_program->pg_name);
> +	dprintk("svc: svc_destroy(%s)\n", serv->sv_programs->pg_name);
>  	timer_shutdown_sync(&serv->sv_temptimer);
>  
>  	/*
>  	 * Remaining transports at this point are not expected.
>  	 */
>  	WARN_ONCE(!list_empty(&serv->sv_permsocks),
> -		  "SVC: permsocks remain for %s\n", serv->sv_program->pg_name);
> +		  "SVC: permsocks remain for %s\n", serv->sv_programs->pg_name);
>  	WARN_ONCE(!list_empty(&serv->sv_tempsocks),
> -		  "SVC: tempsocks remain for %s\n", serv->sv_program->pg_name);
> +		  "SVC: tempsocks remain for %s\n", serv->sv_programs->pg_name);
>  
>  	cache_clean_deferred(serv);
>  
> @@ -1149,15 +1154,16 @@ int svc_register(const struct svc_serv *serv, struct net *net,
>  		 const int family, const unsigned short proto,
>  		 const unsigned short port)
>  {
> -	struct svc_program	*progp;
> -	unsigned int		i;
> +	unsigned int		p, i;
>  	int			error = 0;
>  
>  	WARN_ON_ONCE(proto == 0 && port == 0);
>  	if (proto == 0 && port == 0)
>  		return -EINVAL;
>  
> -	for (progp = serv->sv_program; progp; progp = progp->pg_next) {
> +	for (p = 0; p < serv->sv_nprogs; p++) {
> +		struct svc_program *progp = &serv->sv_programs[p];
> +
>  		for (i = 0; i < progp->pg_nvers; i++) {
>  
>  			error = progp->pg_rpcbind_set(net, progp, i,
> @@ -1209,13 +1215,14 @@ static void __svc_unregister(struct net *net, const u32 program, const u32 versi
>  static void svc_unregister(const struct svc_serv *serv, struct net *net)
>  {
>  	struct sighand_struct *sighand;
> -	struct svc_program *progp;
>  	unsigned long flags;
> -	unsigned int i;
> +	unsigned int p, i;
>  
>  	clear_thread_flag(TIF_SIGPENDING);
>  
> -	for (progp = serv->sv_program; progp; progp = progp->pg_next) {
> +	for (p = 0; p < serv->sv_nprogs; p++) {
> +		struct svc_program *progp = &serv->sv_programs[p];
> +
>  		for (i = 0; i < progp->pg_nvers; i++) {
>  			if (progp->pg_vers[i] == NULL)
>  				continue;
> @@ -1321,7 +1328,7 @@ svc_process_common(struct svc_rqst *rqstp)
>  	struct svc_process_info process;
>  	enum svc_auth_status	auth_res;
>  	unsigned int		aoffset;
> -	int			rc;
> +	int			pr, rc;
>  	__be32			*p;
>  
>  	/* Will be turned off only when NFSv4 Sessions are used */
> @@ -1345,9 +1352,12 @@ svc_process_common(struct svc_rqst *rqstp)
>  	rqstp->rq_vers = be32_to_cpup(p++);
>  	rqstp->rq_proc = be32_to_cpup(p);
>  
> -	for (progp = serv->sv_program; progp; progp = progp->pg_next)
> +	for (pr = 0; pr < serv->sv_nprogs; pr++) {
> +		progp = &serv->sv_programs[pr];
> +
>  		if (rqstp->rq_prog == progp->pg_prog)
>  			break;
> +	}
>  
>  	/*
>  	 * Decode auth data, and add verifier to reply buffer.
> diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c
> index 53ebc719ff5a..43c57124de52 100644
> --- a/net/sunrpc/svc_xprt.c
> +++ b/net/sunrpc/svc_xprt.c
> @@ -268,7 +268,7 @@ static int _svc_xprt_create(struct svc_serv *serv, const char *xprt_name,
>  		spin_unlock(&svc_xprt_class_lock);
>  		newxprt = xcl->xcl_ops->xpo_create(serv, net, sap, len, flags);
>  		if (IS_ERR(newxprt)) {
> -			trace_svc_xprt_create_err(serv->sv_program->pg_name,
> +			trace_svc_xprt_create_err(serv->sv_programs->pg_name,
>  						  xcl->xcl_name, sap, len,
>  						  newxprt);
>  			module_put(xcl->xcl_owner);
> diff --git a/net/sunrpc/svcauth_unix.c b/net/sunrpc/svcauth_unix.c
> index 04b45588ae6f..8ca98b146ec8 100644
> --- a/net/sunrpc/svcauth_unix.c
> +++ b/net/sunrpc/svcauth_unix.c
> @@ -697,7 +697,8 @@ svcauth_unix_set_client(struct svc_rqst *rqstp)
>  	rqstp->rq_auth_stat = rpc_autherr_badcred;
>  	ipm = ip_map_cached_get(xprt);
>  	if (ipm == NULL)
> -		ipm = __ip_map_lookup(sn->ip_map_cache, rqstp->rq_server->sv_program->pg_class,
> +		ipm = __ip_map_lookup(sn->ip_map_cache,
> +				      rqstp->rq_server->sv_programs->pg_class,
>  				    &sin6->sin6_addr);
>  
>  	if (ipm == NULL)

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