Commit b4d8f228 authored by Jeff Layton's avatar Jeff Layton Committed by Chuck Lever
Browse files

nfsd: make nfsd_svc take an array of thread counts 



Now that the refcounting is fixed, rework nfsd_svc to use the same
thread setup as the pool_threads interface. Have it take an array of
thread counts instead of just a single value, and pass that from the
netlink threads set interface.  Since the new netlink interface doesn't
have the same restriction as pool_threads, move the guard against
shutting down all threads to write_pool_threads.

Signed-off-by: default avatarJeff Layton <jlayton@kernel.org>
Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
parent 8e0c8d23

fs/nfsd/nfsctl.c

+10 −2
Original line number Diff line number Diff line
@@ -406,7 +406,7 @@ static ssize_t write_threads(struct file *file, char *buf, size_t size) 
			return -EINVAL;

		trace_nfsd_ctl_threads(net, newthreads);

		mutex_lock(&nfsd_mutex);

		rv = nfsd_svc(newthreads, net, file->f_cred, NULL);

		rv = nfsd_svc(1, &newthreads, net, file->f_cred, NULL);

		mutex_unlock(&nfsd_mutex);

		if (rv < 0)

			return rv;
@@ -481,6 +481,14 @@ static ssize_t write_pool_threads(struct file *file, char *buf, size_t size) 
				goto out_free;

			trace_nfsd_ctl_pool_threads(net, i, nthreads[i]);

		}



		/*

		 * There must always be a thread in pool 0; the admin

		 * can't shut down NFS completely using pool_threads.

		 */

		if (nthreads[0] == 0)

			nthreads[0] = 1;



		rv = nfsd_set_nrthreads(i, nthreads, net);

		if (rv)

			goto out_free;
@@ -1696,7 +1704,7 @@ int nfsd_nl_threads_set_doit(struct sk_buff *skb, struct genl_info *info) 
			scope = nla_data(attr);

	}



	ret = nfsd_svc(nthreads, net, get_current_cred(), scope);

	ret = nfsd_svc(1, &nthreads, net, get_current_cred(), scope);



out_unlock:

	mutex_unlock(&nfsd_mutex);

fs/nfsd/nfsd.h

+2 −1
Original line number Diff line number Diff line
@@ -103,7 +103,8 @@ bool nfssvc_encode_voidres(struct svc_rqst *rqstp, 
/*

 * Function prototypes.

 */

int		nfsd_svc(int nrservs, struct net *net, const struct cred *cred, const char *scope);

int		nfsd_svc(int n, int *nservers, struct net *net,

			 const struct cred *cred, const char *scope);

int		nfsd_dispatch(struct svc_rqst *rqstp);



int		nfsd_nrthreads(struct net *);

fs/nfsd/nfssvc.c

+33 −21
Original line number Diff line number Diff line
@@ -709,6 +709,19 @@ int nfsd_get_nrthreads(int n, int *nthreads, struct net *net) 
	return 0;

}



/**

 * nfsd_set_nrthreads - set the number of running threads in the net's service

 * @n: number of array members in @nthreads

 * @nthreads: array of thread counts for each pool

 * @net: network namespace to operate within

 *

 * This function alters the number of running threads for the given network

 * namespace in each pool. If passed an array longer then the number of pools

 * the extra pool settings are ignored. If passed an array shorter than the

 * number of pools, the missing values are interpreted as 0's.

 *

 * Returns 0 on success or a negative errno on error.

 */

int nfsd_set_nrthreads(int n, int *nthreads, struct net *net)

{

	int i = 0;
@@ -716,11 +729,18 @@ int nfsd_set_nrthreads(int n, int *nthreads, struct net *net) 
	int err = 0;

	struct nfsd_net *nn = net_generic(net, nfsd_net_id);



	WARN_ON(!mutex_is_locked(&nfsd_mutex));

	lockdep_assert_held(&nfsd_mutex);



	if (nn->nfsd_serv == NULL || n <= 0)

		return 0;



	/*

	 * Special case: When n == 1, pass in NULL for the pool, so that the

	 * change is distributed equally among them.

	 */

	if (n == 1)

		return svc_set_num_threads(nn->nfsd_serv, NULL, nthreads[0]);



	if (n > nn->nfsd_serv->sv_nrpools)

		n = nn->nfsd_serv->sv_nrpools;
@@ -743,13 +763,6 @@ int nfsd_set_nrthreads(int n, int *nthreads, struct net *net) 
		}

	}



	/*

	 * There must always be a thread in pool 0; the admin

	 * can't shut down NFS completely using pool_threads.

	 */

	if (nthreads[0] == 0)

		nthreads[0] = 1;



	/* apply the new numbers */

	for (i = 0; i < n; i++) {

		err = svc_set_num_threads(nn->nfsd_serv,
@@ -761,13 +774,19 @@ int nfsd_set_nrthreads(int n, int *nthreads, struct net *net) 
	return err;

}



/*

 * Adjust the number of threads and return the new number of threads.

 * This is also the function that starts the server if necessary, if

 * this is the first time nrservs is nonzero.

/**

 * nfsd_svc: start up or shut down the nfsd server

 * @n: number of array members in @nthreads

 * @nthreads: array of thread counts for each pool

 * @net: network namespace to operate within

 * @cred: credentials to use for xprt creation

 * @scope: server scope value (defaults to nodename)

 *

 * Adjust the number of threads in each pool and return the new

 * total number of threads in the service.

 */

int

nfsd_svc(int nrservs, struct net *net, const struct cred *cred, const char *scope)

nfsd_svc(int n, int *nthreads, struct net *net, const struct cred *cred, const char *scope)

{

	int	error;

	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
@@ -777,13 +796,6 @@ nfsd_svc(int nrservs, struct net *net, const struct cred *cred, const char *scop 


	dprintk("nfsd: creating service\n");



	nrservs = max(nrservs, 0);

	nrservs = min(nrservs, NFSD_MAXSERVS);

	error = 0;



	if (nrservs == 0 && nn->nfsd_serv == NULL)

		goto out;



	strscpy(nn->nfsd_name, scope ? scope : utsname()->nodename,

		sizeof(nn->nfsd_name));
@@ -795,7 +807,7 @@ nfsd_svc(int nrservs, struct net *net, const struct cred *cred, const char *scop 
	error = nfsd_startup_net(net, cred);

	if (error)

		goto out_put;

	error = svc_set_num_threads(serv, NULL, nrservs);

	error = nfsd_set_nrthreads(n, nthreads, net);

	if (error)

		goto out_put;

	error = serv->sv_nrthreads;