diff mbox series

[2/2] sunrpc: remove all connection limit configuration

Message ID 20241209004310.728309-3-neilb@suse.de (mailing list archive)
State Under Review
Headers show
Series nfsd: don't use sv_nrthreads in connection limiting | expand

Commit Message

NeilBrown Dec. 9, 2024, 12:41 a.m. UTC
Now that the connection limit only apply to unconfirmed connections,
there is no need to configure it.  So remove all the configuration and
fix the number of unconfirmed connections as always 64 - which is
now given a name: XPT_MAX_TMP_CONN

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: NeilBrown <neilb@suse.de>
---
 fs/lockd/svc.c                  |  8 -------
 fs/nfsd/netns.h                 |  6 -----
 fs/nfsd/nfsctl.c                | 42 ---------------------------------
 fs/nfsd/nfssvc.c                |  5 ----
 include/linux/sunrpc/svc.h      |  4 ----
 include/linux/sunrpc/svc_xprt.h |  6 +++++
 net/sunrpc/svc_xprt.c           |  8 +------
 7 files changed, 7 insertions(+), 72 deletions(-)

Comments

Chuck Lever Dec. 9, 2024, 5:27 p.m. UTC | #1
On 12/8/24 7:41 PM, NeilBrown wrote:
> Now that the connection limit only apply to unconfirmed connections,
> there is no need to configure it.  So remove all the configuration and
> fix the number of unconfirmed connections as always 64 - which is
> now given a name: XPT_MAX_TMP_CONN
> 
> Reviewed-by: Jeff Layton <jlayton@kernel.org>
> Signed-off-by: NeilBrown <neilb@suse.de>
> ---
>   fs/lockd/svc.c                  |  8 -------
>   fs/nfsd/netns.h                 |  6 -----
>   fs/nfsd/nfsctl.c                | 42 ---------------------------------
>   fs/nfsd/nfssvc.c                |  5 ----
>   include/linux/sunrpc/svc.h      |  4 ----
>   include/linux/sunrpc/svc_xprt.h |  6 +++++
>   net/sunrpc/svc_xprt.c           |  8 +------
>   7 files changed, 7 insertions(+), 72 deletions(-)
> 
> diff --git a/fs/lockd/svc.c b/fs/lockd/svc.c
> index 4ec22c2f2ea3..7ded57ec3a60 100644
> --- a/fs/lockd/svc.c
> +++ b/fs/lockd/svc.c
> @@ -70,9 +70,6 @@ static unsigned long		nlm_grace_period;
>   unsigned long			nlm_timeout = LOCKD_DFLT_TIMEO;
>   static int			nlm_udpport, nlm_tcpport;
>   
> -/* RLIM_NOFILE defaults to 1024. That seems like a reasonable default here. */
> -static unsigned int		nlm_max_connections = 1024;
> -
>   /*
>    * Constants needed for the sysctl interface.
>    */
> @@ -136,9 +133,6 @@ lockd(void *vrqstp)
>   	 * NFS mount or NFS daemon has gone away.
>   	 */
>   	while (!svc_thread_should_stop(rqstp)) {
> -		/* update sv_maxconn if it has changed */
> -		rqstp->rq_server->sv_maxconn = nlm_max_connections;
> -
>   		nlmsvc_retry_blocked(rqstp);
>   		svc_recv(rqstp);
>   	}
> @@ -340,7 +334,6 @@ static int lockd_get(void)
>   		return -ENOMEM;
>   	}
>   
> -	serv->sv_maxconn = nlm_max_connections;
>   	error = svc_set_num_threads(serv, NULL, 1);
>   	if (error < 0) {
>   		svc_destroy(&serv);
> @@ -542,7 +535,6 @@ module_param_call(nlm_udpport, param_set_port, param_get_int,
>   module_param_call(nlm_tcpport, param_set_port, param_get_int,
>   		  &nlm_tcpport, 0644);
>   module_param(nsm_use_hostnames, bool, 0644);
> -module_param(nlm_max_connections, uint, 0644);

We've discussed deprecation and removal of items from /proc/fs/nfsd
before, but removing a module parameter seems like it needs to be
handled with the usual deprecation schedule?


>   static int lockd_init_net(struct net *net)
>   {
> diff --git a/fs/nfsd/netns.h b/fs/nfsd/netns.h
> index a05a45bb1978..4a07b8d0837b 100644
> --- a/fs/nfsd/netns.h
> +++ b/fs/nfsd/netns.h
> @@ -128,12 +128,6 @@ struct nfsd_net {
>   	seqlock_t writeverf_lock;
>   	unsigned char writeverf[8];
>   
> -	/*
> -	 * Max number of non-validated connections this nfsd container
> -	 * will allow.  Defaults to '0' gets mapped to 64.
> -	 */
> -	unsigned int max_connections;
> -
>   	u32 clientid_base;
>   	u32 clientid_counter;
>   	u32 clverifier_counter;
> diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
> index 3adbc05ebaac..95ea4393305b 100644
> --- a/fs/nfsd/nfsctl.c
> +++ b/fs/nfsd/nfsctl.c
> @@ -48,7 +48,6 @@ enum {
>   	NFSD_Versions,
>   	NFSD_Ports,
>   	NFSD_MaxBlkSize,
> -	NFSD_MaxConnections,
>   	NFSD_Filecache,
>   	NFSD_Leasetime,
>   	NFSD_Gracetime,
> @@ -68,7 +67,6 @@ static ssize_t write_pool_threads(struct file *file, char *buf, size_t size);
>   static ssize_t write_versions(struct file *file, char *buf, size_t size);
>   static ssize_t write_ports(struct file *file, char *buf, size_t size);
>   static ssize_t write_maxblksize(struct file *file, char *buf, size_t size);
> -static ssize_t write_maxconn(struct file *file, char *buf, size_t size);
>   #ifdef CONFIG_NFSD_V4
>   static ssize_t write_leasetime(struct file *file, char *buf, size_t size);
>   static ssize_t write_gracetime(struct file *file, char *buf, size_t size);
> @@ -87,7 +85,6 @@ static ssize_t (*const write_op[])(struct file *, char *, size_t) = {
>   	[NFSD_Versions] = write_versions,
>   	[NFSD_Ports] = write_ports,
>   	[NFSD_MaxBlkSize] = write_maxblksize,
> -	[NFSD_MaxConnections] = write_maxconn,
>   #ifdef CONFIG_NFSD_V4
>   	[NFSD_Leasetime] = write_leasetime,
>   	[NFSD_Gracetime] = write_gracetime,
> @@ -902,44 +899,6 @@ static ssize_t write_maxblksize(struct file *file, char *buf, size_t size)
>   							nfsd_max_blksize);
>   }
>   
> -/*
> - * write_maxconn - Set or report the current max number of connections
> - *
> - * Input:
> - *			buf:		ignored
> - *			size:		zero
> - * OR
> - *
> - * Input:
> - *			buf:		C string containing an unsigned
> - *					integer value representing the new
> - *					number of max connections
> - *			size:		non-zero length of C string in @buf
> - * Output:
> - *	On success:	passed-in buffer filled with '\n'-terminated C string
> - *			containing numeric value of max_connections setting
> - *			for this net namespace;
> - *			return code is the size in bytes of the string
> - *	On error:	return code is zero or a negative errno value
> - */
> -static ssize_t write_maxconn(struct file *file, char *buf, size_t size)
> -{
> -	char *mesg = buf;
> -	struct nfsd_net *nn = net_generic(netns(file), nfsd_net_id);
> -	unsigned int maxconn = nn->max_connections;
> -
> -	if (size > 0) {
> -		int rv = get_uint(&mesg, &maxconn);
> -
> -		if (rv)
> -			return rv;
> -		trace_nfsd_ctl_maxconn(netns(file), maxconn);
> -		nn->max_connections = maxconn;
> -	}
> -
> -	return scnprintf(buf, SIMPLE_TRANSACTION_LIMIT, "%u\n", maxconn);
> -}
> -
>   #ifdef CONFIG_NFSD_V4
>   static ssize_t __nfsd4_write_time(struct file *file, char *buf, size_t size,
>   				  time64_t *time, struct nfsd_net *nn)
> @@ -1372,7 +1331,6 @@ static int nfsd_fill_super(struct super_block *sb, struct fs_context *fc)
>   		[NFSD_Versions] = {"versions", &transaction_ops, S_IWUSR|S_IRUSR},
>   		[NFSD_Ports] = {"portlist", &transaction_ops, S_IWUSR|S_IRUGO},
>   		[NFSD_MaxBlkSize] = {"max_block_size", &transaction_ops, S_IWUSR|S_IRUGO},
> -		[NFSD_MaxConnections] = {"max_connections", &transaction_ops, S_IWUSR|S_IRUGO},
>   		[NFSD_Filecache] = {"filecache", &nfsd_file_cache_stats_fops, S_IRUGO},
>   #ifdef CONFIG_NFSD_V4
>   		[NFSD_Leasetime] = {"nfsv4leasetime", &transaction_ops, S_IWUSR|S_IRUSR},
> diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c
> index 49e2f32102ab..b77097de5936 100644
> --- a/fs/nfsd/nfssvc.c
> +++ b/fs/nfsd/nfssvc.c
> @@ -668,7 +668,6 @@ int nfsd_create_serv(struct net *net)
>   	if (serv == NULL)
>   		return -ENOMEM;
>   
> -	serv->sv_maxconn = nn->max_connections;
>   	error = svc_bind(serv, net);
>   	if (error < 0) {
>   		svc_destroy(&serv);
> @@ -954,11 +953,7 @@ nfsd(void *vrqstp)
>   	 * The main request loop
>   	 */
>   	while (!svc_thread_should_stop(rqstp)) {
> -		/* Update sv_maxconn if it has changed */
> -		rqstp->rq_server->sv_maxconn = nn->max_connections;
> -
>   		svc_recv(rqstp);
> -
>   		nfsd_file_net_dispose(nn);
>   	}
>   
> diff --git a/include/linux/sunrpc/svc.h b/include/linux/sunrpc/svc.h
> index 617ebfff2f30..9d288a673705 100644
> --- a/include/linux/sunrpc/svc.h
> +++ b/include/linux/sunrpc/svc.h
> @@ -72,10 +72,6 @@ struct svc_serv {
>   	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
> -						 * on number of threads. */
> -
>   	unsigned int		sv_max_payload;	/* datagram payload size */
>   	unsigned int		sv_max_mesg;	/* max_payload + 1 page for overheads */
>   	unsigned int		sv_xdrsize;	/* XDR buffer size */
> diff --git a/include/linux/sunrpc/svc_xprt.h b/include/linux/sunrpc/svc_xprt.h
> index 35929a7727c7..114051ad985a 100644
> --- a/include/linux/sunrpc/svc_xprt.h
> +++ b/include/linux/sunrpc/svc_xprt.h
> @@ -105,6 +105,12 @@ enum {
>   				 */
>   };
>   
> +/*
> + * Maximum number of "tmp" connections - those without XPT_PEER_VALID -
> + * permitted on any service.
> + */
> +#define XPT_MAX_TMP_CONN	64
> +
>   static inline void svc_xprt_set_valid(struct svc_xprt *xpt)
>   {
>   	if (test_bit(XPT_TEMP, &xpt->xpt_flags) &&
> diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c
> index ff5b8bb8a88f..070bdeb50496 100644
> --- a/net/sunrpc/svc_xprt.c
> +++ b/net/sunrpc/svc_xprt.c
> @@ -619,16 +619,10 @@ int svc_port_is_privileged(struct sockaddr *sin)
>    * The only somewhat efficient mechanism would be if drop old
>    * connections from the same IP first. But right now we don't even
>    * record the client IP in svc_sock.
> - *
> - * single-threaded services that expect a lot of clients will probably
> - * need to set sv_maxconn to override the default value which is based
> - * on the number of threads
>    */
>   static void svc_check_conn_limits(struct svc_serv *serv)
>   {
> -	unsigned int limit = serv->sv_maxconn ? serv->sv_maxconn : 64;
> -
> -	if (serv->sv_tmpcnt > limit) {
> +	if (serv->sv_tmpcnt > XPT_MAX_TMP_CONN) {
>   		struct svc_xprt *xprt = NULL, *xprti;
>   		spin_lock_bh(&serv->sv_lock);
>   		if (!list_empty(&serv->sv_tempsocks)) {
Jeff Layton Dec. 10, 2024, 12:29 p.m. UTC | #2
On Mon, 2024-12-09 at 12:27 -0500, Chuck Lever wrote:
> On 12/8/24 7:41 PM, NeilBrown wrote:
> > Now that the connection limit only apply to unconfirmed connections,
> > there is no need to configure it.  So remove all the configuration and
> > fix the number of unconfirmed connections as always 64 - which is
> > now given a name: XPT_MAX_TMP_CONN
> > 
> > Reviewed-by: Jeff Layton <jlayton@kernel.org>
> > Signed-off-by: NeilBrown <neilb@suse.de>
> > ---
> >   fs/lockd/svc.c                  |  8 -------
> >   fs/nfsd/netns.h                 |  6 -----
> >   fs/nfsd/nfsctl.c                | 42 ---------------------------------
> >   fs/nfsd/nfssvc.c                |  5 ----
> >   include/linux/sunrpc/svc.h      |  4 ----
> >   include/linux/sunrpc/svc_xprt.h |  6 +++++
> >   net/sunrpc/svc_xprt.c           |  8 +------
> >   7 files changed, 7 insertions(+), 72 deletions(-)
> > 
> > diff --git a/fs/lockd/svc.c b/fs/lockd/svc.c
> > index 4ec22c2f2ea3..7ded57ec3a60 100644
> > --- a/fs/lockd/svc.c
> > +++ b/fs/lockd/svc.c
> > @@ -70,9 +70,6 @@ static unsigned long		nlm_grace_period;
> >   unsigned long			nlm_timeout = LOCKD_DFLT_TIMEO;
> >   static int			nlm_udpport, nlm_tcpport;
> >   
> > -/* RLIM_NOFILE defaults to 1024. That seems like a reasonable default here. */
> > -static unsigned int		nlm_max_connections = 1024;
> > -
> >   /*
> >    * Constants needed for the sysctl interface.
> >    */
> > @@ -136,9 +133,6 @@ lockd(void *vrqstp)
> >   	 * NFS mount or NFS daemon has gone away.
> >   	 */
> >   	while (!svc_thread_should_stop(rqstp)) {
> > -		/* update sv_maxconn if it has changed */
> > -		rqstp->rq_server->sv_maxconn = nlm_max_connections;
> > -
> >   		nlmsvc_retry_blocked(rqstp);
> >   		svc_recv(rqstp);
> >   	}
> > @@ -340,7 +334,6 @@ static int lockd_get(void)
> >   		return -ENOMEM;
> >   	}
> >   
> > -	serv->sv_maxconn = nlm_max_connections;
> >   	error = svc_set_num_threads(serv, NULL, 1);
> >   	if (error < 0) {
> >   		svc_destroy(&serv);
> > @@ -542,7 +535,6 @@ module_param_call(nlm_udpport, param_set_port, param_get_int,
> >   module_param_call(nlm_tcpport, param_set_port, param_get_int,
> >   		  &nlm_tcpport, 0644);
> >   module_param(nsm_use_hostnames, bool, 0644);
> > -module_param(nlm_max_connections, uint, 0644);
> 
> We've discussed deprecation and removal of items from /proc/fs/nfsd
> before, but removing a module parameter seems like it needs to be
> handled with the usual deprecation schedule?
> 

Yeah, that could break someone on an upgrade. What we should probably
do is keep the knob around, but just make it not do anything now, and
throw a pr_warn message or something if someone tries to set it.
Eventually in a year or two, we should be able to remove it.


> >   static int lockd_init_net(struct net *net)
> >   {
> > diff --git a/fs/nfsd/netns.h b/fs/nfsd/netns.h
> > index a05a45bb1978..4a07b8d0837b 100644
> > --- a/fs/nfsd/netns.h
> > +++ b/fs/nfsd/netns.h
> > @@ -128,12 +128,6 @@ struct nfsd_net {
> >   	seqlock_t writeverf_lock;
> >   	unsigned char writeverf[8];
> >   
> > -	/*
> > -	 * Max number of non-validated connections this nfsd container
> > -	 * will allow.  Defaults to '0' gets mapped to 64.
> > -	 */
> > -	unsigned int max_connections;
> > -
> >   	u32 clientid_base;
> >   	u32 clientid_counter;
> >   	u32 clverifier_counter;
> > diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
> > index 3adbc05ebaac..95ea4393305b 100644
> > --- a/fs/nfsd/nfsctl.c
> > +++ b/fs/nfsd/nfsctl.c
> > @@ -48,7 +48,6 @@ enum {
> >   	NFSD_Versions,
> >   	NFSD_Ports,
> >   	NFSD_MaxBlkSize,
> > -	NFSD_MaxConnections,
> >   	NFSD_Filecache,
> >   	NFSD_Leasetime,
> >   	NFSD_Gracetime,
> > @@ -68,7 +67,6 @@ static ssize_t write_pool_threads(struct file *file, char *buf, size_t size);
> >   static ssize_t write_versions(struct file *file, char *buf, size_t size);
> >   static ssize_t write_ports(struct file *file, char *buf, size_t size);
> >   static ssize_t write_maxblksize(struct file *file, char *buf, size_t size);
> > -static ssize_t write_maxconn(struct file *file, char *buf, size_t size);
> >   #ifdef CONFIG_NFSD_V4
> >   static ssize_t write_leasetime(struct file *file, char *buf, size_t size);
> >   static ssize_t write_gracetime(struct file *file, char *buf, size_t size);
> > @@ -87,7 +85,6 @@ static ssize_t (*const write_op[])(struct file *, char *, size_t) = {
> >   	[NFSD_Versions] = write_versions,
> >   	[NFSD_Ports] = write_ports,
> >   	[NFSD_MaxBlkSize] = write_maxblksize,
> > -	[NFSD_MaxConnections] = write_maxconn,
> >   #ifdef CONFIG_NFSD_V4
> >   	[NFSD_Leasetime] = write_leasetime,
> >   	[NFSD_Gracetime] = write_gracetime,
> > @@ -902,44 +899,6 @@ static ssize_t write_maxblksize(struct file *file, char *buf, size_t size)
> >   							nfsd_max_blksize);
> >   }
> >   
> > -/*
> > - * write_maxconn - Set or report the current max number of connections
> > - *
> > - * Input:
> > - *			buf:		ignored
> > - *			size:		zero
> > - * OR
> > - *
> > - * Input:
> > - *			buf:		C string containing an unsigned
> > - *					integer value representing the new
> > - *					number of max connections
> > - *			size:		non-zero length of C string in @buf
> > - * Output:
> > - *	On success:	passed-in buffer filled with '\n'-terminated C string
> > - *			containing numeric value of max_connections setting
> > - *			for this net namespace;
> > - *			return code is the size in bytes of the string
> > - *	On error:	return code is zero or a negative errno value
> > - */
> > -static ssize_t write_maxconn(struct file *file, char *buf, size_t size)
> > -{
> > -	char *mesg = buf;
> > -	struct nfsd_net *nn = net_generic(netns(file), nfsd_net_id);
> > -	unsigned int maxconn = nn->max_connections;
> > -
> > -	if (size > 0) {
> > -		int rv = get_uint(&mesg, &maxconn);
> > -
> > -		if (rv)
> > -			return rv;
> > -		trace_nfsd_ctl_maxconn(netns(file), maxconn);
> > -		nn->max_connections = maxconn;
> > -	}
> > -
> > -	return scnprintf(buf, SIMPLE_TRANSACTION_LIMIT, "%u\n", maxconn);
> > -}
> > -
> >   #ifdef CONFIG_NFSD_V4
> >   static ssize_t __nfsd4_write_time(struct file *file, char *buf, size_t size,
> >   				  time64_t *time, struct nfsd_net *nn)
> > @@ -1372,7 +1331,6 @@ static int nfsd_fill_super(struct super_block *sb, struct fs_context *fc)
> >   		[NFSD_Versions] = {"versions", &transaction_ops, S_IWUSR|S_IRUSR},
> >   		[NFSD_Ports] = {"portlist", &transaction_ops, S_IWUSR|S_IRUGO},
> >   		[NFSD_MaxBlkSize] = {"max_block_size", &transaction_ops, S_IWUSR|S_IRUGO},
> > -		[NFSD_MaxConnections] = {"max_connections", &transaction_ops, S_IWUSR|S_IRUGO},
> >   		[NFSD_Filecache] = {"filecache", &nfsd_file_cache_stats_fops, S_IRUGO},
> >   #ifdef CONFIG_NFSD_V4
> >   		[NFSD_Leasetime] = {"nfsv4leasetime", &transaction_ops, S_IWUSR|S_IRUSR},
> > diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c
> > index 49e2f32102ab..b77097de5936 100644
> > --- a/fs/nfsd/nfssvc.c
> > +++ b/fs/nfsd/nfssvc.c
> > @@ -668,7 +668,6 @@ int nfsd_create_serv(struct net *net)
> >   	if (serv == NULL)
> >   		return -ENOMEM;
> >   
> > -	serv->sv_maxconn = nn->max_connections;
> >   	error = svc_bind(serv, net);
> >   	if (error < 0) {
> >   		svc_destroy(&serv);
> > @@ -954,11 +953,7 @@ nfsd(void *vrqstp)
> >   	 * The main request loop
> >   	 */
> >   	while (!svc_thread_should_stop(rqstp)) {
> > -		/* Update sv_maxconn if it has changed */
> > -		rqstp->rq_server->sv_maxconn = nn->max_connections;
> > -
> >   		svc_recv(rqstp);
> > -
> >   		nfsd_file_net_dispose(nn);
> >   	}
> >   
> > diff --git a/include/linux/sunrpc/svc.h b/include/linux/sunrpc/svc.h
> > index 617ebfff2f30..9d288a673705 100644
> > --- a/include/linux/sunrpc/svc.h
> > +++ b/include/linux/sunrpc/svc.h
> > @@ -72,10 +72,6 @@ struct svc_serv {
> >   	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
> > -						 * on number of threads. */
> > -
> >   	unsigned int		sv_max_payload;	/* datagram payload size */
> >   	unsigned int		sv_max_mesg;	/* max_payload + 1 page for overheads */
> >   	unsigned int		sv_xdrsize;	/* XDR buffer size */
> > diff --git a/include/linux/sunrpc/svc_xprt.h b/include/linux/sunrpc/svc_xprt.h
> > index 35929a7727c7..114051ad985a 100644
> > --- a/include/linux/sunrpc/svc_xprt.h
> > +++ b/include/linux/sunrpc/svc_xprt.h
> > @@ -105,6 +105,12 @@ enum {
> >   				 */
> >   };
> >   
> > +/*
> > + * Maximum number of "tmp" connections - those without XPT_PEER_VALID -
> > + * permitted on any service.
> > + */
> > +#define XPT_MAX_TMP_CONN	64
> > +
> >   static inline void svc_xprt_set_valid(struct svc_xprt *xpt)
> >   {
> >   	if (test_bit(XPT_TEMP, &xpt->xpt_flags) &&
> > diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c
> > index ff5b8bb8a88f..070bdeb50496 100644
> > --- a/net/sunrpc/svc_xprt.c
> > +++ b/net/sunrpc/svc_xprt.c
> > @@ -619,16 +619,10 @@ int svc_port_is_privileged(struct sockaddr *sin)
> >    * The only somewhat efficient mechanism would be if drop old
> >    * connections from the same IP first. But right now we don't even
> >    * record the client IP in svc_sock.
> > - *
> > - * single-threaded services that expect a lot of clients will probably
> > - * need to set sv_maxconn to override the default value which is based
> > - * on the number of threads
> >    */
> >   static void svc_check_conn_limits(struct svc_serv *serv)
> >   {
> > -	unsigned int limit = serv->sv_maxconn ? serv->sv_maxconn : 64;
> > -
> > -	if (serv->sv_tmpcnt > limit) {
> > +	if (serv->sv_tmpcnt > XPT_MAX_TMP_CONN) {
> >   		struct svc_xprt *xprt = NULL, *xprti;
> >   		spin_lock_bh(&serv->sv_lock);
> >   		if (!list_empty(&serv->sv_tempsocks)) {
> 
>
NeilBrown Dec. 11, 2024, 3:48 a.m. UTC | #3
On Tue, 10 Dec 2024, Jeff Layton wrote:
> On Mon, 2024-12-09 at 12:27 -0500, Chuck Lever wrote:
> > On 12/8/24 7:41 PM, NeilBrown wrote:

> > >   module_param(nsm_use_hostnames, bool, 0644);
> > > -module_param(nlm_max_connections, uint, 0644);
> > 
> > We've discussed deprecation and removal of items from /proc/fs/nfsd
> > before, but removing a module parameter seems like it needs to be
> > handled with the usual deprecation schedule?
> > 
> 
> Yeah, that could break someone on an upgrade. What we should probably
> do is keep the knob around, but just make it not do anything now, and
> throw a pr_warn message or something if someone tries to set it.
> Eventually in a year or two, we should be able to remove it.
> 

What might break?

modprobe or insmod won't have a problem.  The kernel will emit 
   nfsd: unknow parameter '...' ignored

but that is not much more than a deprecation warning.

 echo 42 > /sys/modules/nfsd/parameters/nlm_max_connections

will produce "permission denied" but is unlikely to abort a shell script
(unless "-e" is used - which seems unlikely).

I don't think there is a risk here.

Thanks,
NeilBrown
diff mbox series

Patch

diff --git a/fs/lockd/svc.c b/fs/lockd/svc.c
index 4ec22c2f2ea3..7ded57ec3a60 100644
--- a/fs/lockd/svc.c
+++ b/fs/lockd/svc.c
@@ -70,9 +70,6 @@  static unsigned long		nlm_grace_period;
 unsigned long			nlm_timeout = LOCKD_DFLT_TIMEO;
 static int			nlm_udpport, nlm_tcpport;
 
-/* RLIM_NOFILE defaults to 1024. That seems like a reasonable default here. */
-static unsigned int		nlm_max_connections = 1024;
-
 /*
  * Constants needed for the sysctl interface.
  */
@@ -136,9 +133,6 @@  lockd(void *vrqstp)
 	 * NFS mount or NFS daemon has gone away.
 	 */
 	while (!svc_thread_should_stop(rqstp)) {
-		/* update sv_maxconn if it has changed */
-		rqstp->rq_server->sv_maxconn = nlm_max_connections;
-
 		nlmsvc_retry_blocked(rqstp);
 		svc_recv(rqstp);
 	}
@@ -340,7 +334,6 @@  static int lockd_get(void)
 		return -ENOMEM;
 	}
 
-	serv->sv_maxconn = nlm_max_connections;
 	error = svc_set_num_threads(serv, NULL, 1);
 	if (error < 0) {
 		svc_destroy(&serv);
@@ -542,7 +535,6 @@  module_param_call(nlm_udpport, param_set_port, param_get_int,
 module_param_call(nlm_tcpport, param_set_port, param_get_int,
 		  &nlm_tcpport, 0644);
 module_param(nsm_use_hostnames, bool, 0644);
-module_param(nlm_max_connections, uint, 0644);
 
 static int lockd_init_net(struct net *net)
 {
diff --git a/fs/nfsd/netns.h b/fs/nfsd/netns.h
index a05a45bb1978..4a07b8d0837b 100644
--- a/fs/nfsd/netns.h
+++ b/fs/nfsd/netns.h
@@ -128,12 +128,6 @@  struct nfsd_net {
 	seqlock_t writeverf_lock;
 	unsigned char writeverf[8];
 
-	/*
-	 * Max number of non-validated connections this nfsd container
-	 * will allow.  Defaults to '0' gets mapped to 64.
-	 */
-	unsigned int max_connections;
-
 	u32 clientid_base;
 	u32 clientid_counter;
 	u32 clverifier_counter;
diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
index 3adbc05ebaac..95ea4393305b 100644
--- a/fs/nfsd/nfsctl.c
+++ b/fs/nfsd/nfsctl.c
@@ -48,7 +48,6 @@  enum {
 	NFSD_Versions,
 	NFSD_Ports,
 	NFSD_MaxBlkSize,
-	NFSD_MaxConnections,
 	NFSD_Filecache,
 	NFSD_Leasetime,
 	NFSD_Gracetime,
@@ -68,7 +67,6 @@  static ssize_t write_pool_threads(struct file *file, char *buf, size_t size);
 static ssize_t write_versions(struct file *file, char *buf, size_t size);
 static ssize_t write_ports(struct file *file, char *buf, size_t size);
 static ssize_t write_maxblksize(struct file *file, char *buf, size_t size);
-static ssize_t write_maxconn(struct file *file, char *buf, size_t size);
 #ifdef CONFIG_NFSD_V4
 static ssize_t write_leasetime(struct file *file, char *buf, size_t size);
 static ssize_t write_gracetime(struct file *file, char *buf, size_t size);
@@ -87,7 +85,6 @@  static ssize_t (*const write_op[])(struct file *, char *, size_t) = {
 	[NFSD_Versions] = write_versions,
 	[NFSD_Ports] = write_ports,
 	[NFSD_MaxBlkSize] = write_maxblksize,
-	[NFSD_MaxConnections] = write_maxconn,
 #ifdef CONFIG_NFSD_V4
 	[NFSD_Leasetime] = write_leasetime,
 	[NFSD_Gracetime] = write_gracetime,
@@ -902,44 +899,6 @@  static ssize_t write_maxblksize(struct file *file, char *buf, size_t size)
 							nfsd_max_blksize);
 }
 
-/*
- * write_maxconn - Set or report the current max number of connections
- *
- * Input:
- *			buf:		ignored
- *			size:		zero
- * OR
- *
- * Input:
- *			buf:		C string containing an unsigned
- *					integer value representing the new
- *					number of max connections
- *			size:		non-zero length of C string in @buf
- * Output:
- *	On success:	passed-in buffer filled with '\n'-terminated C string
- *			containing numeric value of max_connections setting
- *			for this net namespace;
- *			return code is the size in bytes of the string
- *	On error:	return code is zero or a negative errno value
- */
-static ssize_t write_maxconn(struct file *file, char *buf, size_t size)
-{
-	char *mesg = buf;
-	struct nfsd_net *nn = net_generic(netns(file), nfsd_net_id);
-	unsigned int maxconn = nn->max_connections;
-
-	if (size > 0) {
-		int rv = get_uint(&mesg, &maxconn);
-
-		if (rv)
-			return rv;
-		trace_nfsd_ctl_maxconn(netns(file), maxconn);
-		nn->max_connections = maxconn;
-	}
-
-	return scnprintf(buf, SIMPLE_TRANSACTION_LIMIT, "%u\n", maxconn);
-}
-
 #ifdef CONFIG_NFSD_V4
 static ssize_t __nfsd4_write_time(struct file *file, char *buf, size_t size,
 				  time64_t *time, struct nfsd_net *nn)
@@ -1372,7 +1331,6 @@  static int nfsd_fill_super(struct super_block *sb, struct fs_context *fc)
 		[NFSD_Versions] = {"versions", &transaction_ops, S_IWUSR|S_IRUSR},
 		[NFSD_Ports] = {"portlist", &transaction_ops, S_IWUSR|S_IRUGO},
 		[NFSD_MaxBlkSize] = {"max_block_size", &transaction_ops, S_IWUSR|S_IRUGO},
-		[NFSD_MaxConnections] = {"max_connections", &transaction_ops, S_IWUSR|S_IRUGO},
 		[NFSD_Filecache] = {"filecache", &nfsd_file_cache_stats_fops, S_IRUGO},
 #ifdef CONFIG_NFSD_V4
 		[NFSD_Leasetime] = {"nfsv4leasetime", &transaction_ops, S_IWUSR|S_IRUSR},
diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c
index 49e2f32102ab..b77097de5936 100644
--- a/fs/nfsd/nfssvc.c
+++ b/fs/nfsd/nfssvc.c
@@ -668,7 +668,6 @@  int nfsd_create_serv(struct net *net)
 	if (serv == NULL)
 		return -ENOMEM;
 
-	serv->sv_maxconn = nn->max_connections;
 	error = svc_bind(serv, net);
 	if (error < 0) {
 		svc_destroy(&serv);
@@ -954,11 +953,7 @@  nfsd(void *vrqstp)
 	 * The main request loop
 	 */
 	while (!svc_thread_should_stop(rqstp)) {
-		/* Update sv_maxconn if it has changed */
-		rqstp->rq_server->sv_maxconn = nn->max_connections;
-
 		svc_recv(rqstp);
-
 		nfsd_file_net_dispose(nn);
 	}
 
diff --git a/include/linux/sunrpc/svc.h b/include/linux/sunrpc/svc.h
index 617ebfff2f30..9d288a673705 100644
--- a/include/linux/sunrpc/svc.h
+++ b/include/linux/sunrpc/svc.h
@@ -72,10 +72,6 @@  struct svc_serv {
 	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
-						 * on number of threads. */
-
 	unsigned int		sv_max_payload;	/* datagram payload size */
 	unsigned int		sv_max_mesg;	/* max_payload + 1 page for overheads */
 	unsigned int		sv_xdrsize;	/* XDR buffer size */
diff --git a/include/linux/sunrpc/svc_xprt.h b/include/linux/sunrpc/svc_xprt.h
index 35929a7727c7..114051ad985a 100644
--- a/include/linux/sunrpc/svc_xprt.h
+++ b/include/linux/sunrpc/svc_xprt.h
@@ -105,6 +105,12 @@  enum {
 				 */
 };
 
+/*
+ * Maximum number of "tmp" connections - those without XPT_PEER_VALID -
+ * permitted on any service.
+ */
+#define XPT_MAX_TMP_CONN	64
+
 static inline void svc_xprt_set_valid(struct svc_xprt *xpt)
 {
 	if (test_bit(XPT_TEMP, &xpt->xpt_flags) &&
diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c
index ff5b8bb8a88f..070bdeb50496 100644
--- a/net/sunrpc/svc_xprt.c
+++ b/net/sunrpc/svc_xprt.c
@@ -619,16 +619,10 @@  int svc_port_is_privileged(struct sockaddr *sin)
  * The only somewhat efficient mechanism would be if drop old
  * connections from the same IP first. But right now we don't even
  * record the client IP in svc_sock.
- *
- * single-threaded services that expect a lot of clients will probably
- * need to set sv_maxconn to override the default value which is based
- * on the number of threads
  */
 static void svc_check_conn_limits(struct svc_serv *serv)
 {
-	unsigned int limit = serv->sv_maxconn ? serv->sv_maxconn : 64;
-
-	if (serv->sv_tmpcnt > limit) {
+	if (serv->sv_tmpcnt > XPT_MAX_TMP_CONN) {
 		struct svc_xprt *xprt = NULL, *xprti;
 		spin_lock_bh(&serv->sv_lock);
 		if (!list_empty(&serv->sv_tempsocks)) {