[apple/xnu.git] / bsd / nfs / nfs_upcall.c

/*
 * Copyright (c) 2011 Apple Inc.  All rights reserved.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
 *
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. The rights granted to you under the License
 * may not be used to create, or enable the creation or redistribution of,
 * unlawful or unlicensed copies of an Apple operating system, or to
 * circumvent, violate, or enable the circumvention or violation of, any
 * terms of an Apple operating system software license agreement.
 *
 * Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this file.
 *
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
 */
#include <stdint.h>
#include <sys/param.h>
#include <sys/mount_internal.h>
#include <sys/malloc.h>
#include <sys/queue.h>

#include <libkern/libkern.h>
#include <libkern/OSAtomic.h>
#include <kern/debug.h>
#include <kern/thread.h>

#include <nfs/rpcv2.h>
#include <nfs/nfsproto.h>
#include <nfs/nfs.h>

#ifdef NFS_UC_DEBUG
#define DPRINT(fmt, ...) printf(fmt,## __VA_ARGS__)
#else
#define DPRINT(fmt, ...)
#endif

struct nfsrv_uc_arg {
	TAILQ_ENTRY(nfsrv_uc_arg) nua_svcq;
	socket_t nua_so;
	struct nfsrv_sock *nua_slp;
	int nua_waitflag;  /* Should always be MBUF_DONTWAIT */
	uint32_t nua_flags;
	uint32_t nua_qi;
};
#define NFS_UC_QUEUED	0x0001

#define NFS_UC_HASH_SZ 7
#define NFS_UC_HASH(x) ((((uint32_t)(uintptr_t)(x)) >> 3) % nfsrv_uc_thread_count)

TAILQ_HEAD(nfsrv_uc_q, nfsrv_uc_arg);

static struct nfsrv_uc_queue {
	lck_mtx_t		*ucq_lock;
	struct nfsrv_uc_q	ucq_queue[1];
	thread_t		ucq_thd;
	uint32_t		ucq_flags;
} nfsrv_uc_queue_tbl[NFS_UC_HASH_SZ];
#define NFS_UC_QUEUE_SLEEPING	0x0001

static lck_grp_t *nfsrv_uc_group;
static lck_mtx_t *nfsrv_uc_shutdown_lock;
static volatile int nfsrv_uc_shutdown = 0;
static int32_t nfsrv_uc_thread_count;

extern kern_return_t thread_terminate(thread_t);

#ifdef NFS_UC_Q_DEBUG
int nfsrv_uc_use_proxy = 1;
uint32_t nfsrv_uc_queue_limit;
uint32_t nfsrv_uc_queue_max_seen;
volatile uint32_t nfsrv_uc_queue_count;
#endif

/*
 * Thread that dequeues up-calls and runs the nfsrv_rcv routine
 */
static void
nfsrv_uc_thread(void *arg, wait_result_t wr __unused)
{
	int qi = (int)(uintptr_t)arg;
	int error;
	struct nfsrv_uc_arg *ep = NULL;
	struct nfsrv_uc_queue *myqueue = &nfsrv_uc_queue_tbl[qi];

	DPRINT("nfsrv_uc_thread %d started\n", qi);
	while (!nfsrv_uc_shutdown) {
		lck_mtx_lock(myqueue->ucq_lock);

		while (!nfsrv_uc_shutdown && TAILQ_EMPTY(myqueue->ucq_queue)) {
			myqueue->ucq_flags |= NFS_UC_QUEUE_SLEEPING;
			error = msleep(myqueue, myqueue->ucq_lock, PSOCK, "nfsd_upcall_handler", NULL);
			myqueue->ucq_flags &= ~NFS_UC_QUEUE_SLEEPING;
			if (error) {
				printf("nfsrv_uc_thread received error %d\n", error);
			}
		}
		if (nfsrv_uc_shutdown) {
			lck_mtx_unlock(myqueue->ucq_lock);
			break;
		}


		ep = TAILQ_FIRST(myqueue->ucq_queue);
		DPRINT("nfsrv_uc_thread:%d dequeue %p from %p\n", qi, ep, myqueue);

		TAILQ_REMOVE(myqueue->ucq_queue, ep, nua_svcq);

		ep->nua_flags &= ~NFS_UC_QUEUED;

		lck_mtx_unlock(myqueue->ucq_lock);

#ifdef NFS_UC_Q_DEBUG
		OSDecrementAtomic(&nfsrv_uc_queue_count);
#endif

		DPRINT("calling nfsrv_rcv for %p\n", (void *)ep->nua_slp);
		nfsrv_rcv(ep->nua_so, (void *)ep->nua_slp, ep->nua_waitflag);
	}

	lck_mtx_lock(nfsrv_uc_shutdown_lock);
	nfsrv_uc_thread_count--;
	wakeup(&nfsrv_uc_thread_count);
	lck_mtx_unlock(nfsrv_uc_shutdown_lock);

	thread_terminate(current_thread());
}

/*
 * Dequeue a closed nfsrv_sock if needed from the up-call queue.
 * Call from nfsrv_zapsock
 */
void
nfsrv_uc_dequeue(struct nfsrv_sock *slp)
{
	struct nfsrv_uc_arg *ap = slp->ns_ua;
	struct nfsrv_uc_queue *myqueue = &nfsrv_uc_queue_tbl[ap->nua_qi];

	/*
	 * We assume that the socket up-calls have been stop and the socket
	 * is shutting down so no need for acquiring the lock to check that
	 * the flag is cleared.
	 */
	if (ap == NULL || (ap->nua_flags & NFS_UC_QUEUED) == 0)
		return;
	/* If we're queued we might race with nfsrv_uc_thread */
	lck_mtx_lock(myqueue->ucq_lock);
	if (ap->nua_flags & NFS_UC_QUEUED) {
		printf("nfsrv_uc_dequeue remove %p\n", ap);
		TAILQ_REMOVE(myqueue->ucq_queue, ap, nua_svcq);
		ap->nua_flags &= ~NFS_UC_QUEUED;
#ifdef NFS_UC_Q_DEBUG
		OSDecrementAtomic(&nfsrv_uc_queue_count);
#endif		
	}
	lck_mtx_unlock(myqueue->ucq_lock);
}

/*
 * Allocate and initialize globals for nfsrv_sock up-call support.
 */
void
nfsrv_uc_init(void)
{
	int i;

	nfsrv_uc_group = lck_grp_alloc_init("nfs_upcall_locks", LCK_GRP_ATTR_NULL);
	for (i = 0; i < NFS_UC_HASH_SZ; i++) {
		TAILQ_INIT(nfsrv_uc_queue_tbl[i].ucq_queue);
		nfsrv_uc_queue_tbl[i].ucq_lock = lck_mtx_alloc_init(nfsrv_uc_group, LCK_ATTR_NULL);
		nfsrv_uc_queue_tbl[i].ucq_thd = THREAD_NULL;
		nfsrv_uc_queue_tbl[i].ucq_flags = 0;
	}
	nfsrv_uc_shutdown_lock = lck_mtx_alloc_init(nfsrv_uc_group, LCK_ATTR_NULL);
}

/*
 * Start up-call threads to service nfsrv_sock(s)
 * Called from the first call of nfsrv_uc_addsock
 */
static void
nfsrv_uc_start(void)
{
	int32_t i;
	int error;

#ifdef NFS_UC_Q_DEBUG
	if (!nfsrv_uc_use_proxy)
		return;
#endif
	DPRINT("nfsrv_uc_start\n");

	/* Wait until previous shutdown finishes */
	lck_mtx_lock(nfsrv_uc_shutdown_lock);
	while (nfsrv_uc_shutdown || nfsrv_uc_thread_count > 0)
		msleep(&nfsrv_uc_thread_count, nfsrv_uc_shutdown_lock, PSOCK, "nfsd_upcall_shutdown_wait", NULL);

	/* Start up-call threads */
	for (i = 0; i < NFS_UC_HASH_SZ; i++) {
		error = kernel_thread_start(nfsrv_uc_thread, (void *)(uintptr_t)i, &nfsrv_uc_queue_tbl[nfsrv_uc_thread_count].ucq_thd);
		if (!error) {
			nfsrv_uc_thread_count++;
		} else {
			printf("nfsd: Could not start nfsrv_uc_thread: %d\n", error);
		}
	}
	if (nfsrv_uc_thread_count == 0) {
		printf("nfsd: Could not start nfsd proxy up-call service. Falling back\n");
		goto out;
	}

out:
#ifdef NFS_UC_Q_DEBUG
	nfsrv_uc_queue_count = 0ULL;
	nfsrv_uc_queue_max_seen = 0ULL;
#endif
	lck_mtx_unlock(nfsrv_uc_shutdown_lock);
}

/*
 * Stop the up-call threads.
 * Called from nfsrv_uc_cleanup.
 */
static void
nfsrv_uc_stop(void)
{
	int32_t i;
	int32_t thread_count = nfsrv_uc_thread_count;

	DPRINT("Entering nfsrv_uc_stop\n");

	/* Signal up-call threads to stop */
	nfsrv_uc_shutdown = 1;
	for (i = 0; i < thread_count; i++) {
		lck_mtx_lock(nfsrv_uc_queue_tbl[i].ucq_lock);
		wakeup(&nfsrv_uc_queue_tbl[i]);
		lck_mtx_unlock(nfsrv_uc_queue_tbl[i].ucq_lock);
	}

	/* Wait until they are done shutting down */
	lck_mtx_lock(nfsrv_uc_shutdown_lock);
	while (nfsrv_uc_thread_count > 0)
		msleep(&nfsrv_uc_thread_count, nfsrv_uc_shutdown_lock, PSOCK, "nfsd_upcall_shutdown_stop", NULL);

	/* Deallocate old threads */
	for (i = 0; i < nfsrv_uc_thread_count; i++) {
		if (nfsrv_uc_queue_tbl[i].ucq_thd != THREAD_NULL)
			thread_deallocate(nfsrv_uc_queue_tbl[i].ucq_thd);
		nfsrv_uc_queue_tbl[i].ucq_thd = THREAD_NULL;
	}

	/* Enable restarting */
	nfsrv_uc_shutdown = 0;
	lck_mtx_unlock(nfsrv_uc_shutdown_lock);
}

/*
 * Shutdown up-calls for nfsrv_socks.
 *	Make sure nothing is queued on the up-call queues
 *	Shutdown the up-call threads
 * Called from nfssvc_cleanup.
 */
void
nfsrv_uc_cleanup(void)
{
	int i;

	DPRINT("Entering nfsrv_uc_cleanup\n");

	/*
	 * Every thing should be dequeued at this point or will be as sockets are closed
	 * but to be safe, we'll make sure.
	 */
	for (i = 0; i < NFS_UC_HASH_SZ; i++) {
		struct nfsrv_uc_queue *queue = &nfsrv_uc_queue_tbl[i];

		lck_mtx_lock(queue->ucq_lock);
		while (!TAILQ_EMPTY(queue->ucq_queue)) {
			struct nfsrv_uc_arg *ep = TAILQ_FIRST(queue->ucq_queue);
			TAILQ_REMOVE(queue->ucq_queue, ep, nua_svcq);
			ep->nua_flags &= ~NFS_UC_QUEUED;
		}
		lck_mtx_unlock(queue->ucq_lock);
	}

	nfsrv_uc_stop();
}

/*
 * This is the nfs up-call routine for server sockets.
 * We used to set nfsrv_rcv as the up-call routine, but
 * recently that seems like we are doing to much work for
 * the interface thread, so we just queue the arguments
 * that we would have gotten for nfsrv_rcv and let a
 * worker thread dequeue them and pass them on to nfsrv_rcv.
 */
static void
nfsrv_uc_proxy(socket_t so, void *arg, int waitflag)
{
	struct nfsrv_uc_arg *uap = (struct nfsrv_uc_arg *)arg;
	int qi = uap->nua_qi;
	struct nfsrv_uc_queue *myqueue = &nfsrv_uc_queue_tbl[qi];

	lck_mtx_lock(myqueue->ucq_lock);
	DPRINT("nfsrv_uc_proxy called for %p (%p)\n", uap, uap->nua_slp);
	DPRINT("\tUp-call queued on %d for wakeup of %p\n", qi, myqueue);
	if (uap->nua_flags & NFS_UC_QUEUED) {
		lck_mtx_unlock(myqueue->ucq_lock);
		return;  /* Already queued */
	}

	uap->nua_so = so;
	uap->nua_waitflag = waitflag;

	TAILQ_INSERT_TAIL(myqueue->ucq_queue, uap, nua_svcq);

	uap->nua_flags |= NFS_UC_QUEUED;
	if (myqueue->ucq_flags | NFS_UC_QUEUE_SLEEPING)
		wakeup(myqueue);

#ifdef NFS_UC_Q_DEBUG
	{
		uint32_t count = OSIncrementAtomic(&nfsrv_uc_queue_count);
	
		/* This is a bit racey but just for debug */
		if (count > nfsrv_uc_queue_max_seen)
			nfsrv_uc_queue_max_seen = count;

		if (nfsrv_uc_queue_limit && count > nfsrv_uc_queue_limit) {
			panic("nfsd up-call queue limit exceeded\n");
		}
	}
#endif
	lck_mtx_unlock(myqueue->ucq_lock);
}


/*
 * Set the up-call routine on the socket associated with the passed in
 * nfsrv_sock.
 * Assumes nfsd_mutex is held.
 */
void
nfsrv_uc_addsock(struct nfsrv_sock *slp, int start)
{
	int on = 1;
	struct nfsrv_uc_arg *arg;

	if (start && nfsrv_uc_thread_count == 0)
		nfsrv_uc_start();

	/*
	 * We don't take a lock since once we're up nfsrv_uc_thread_count does
	 * not change until shutdown and then we should not be adding sockets to
	 * generate up-calls.
	 */
	if (nfsrv_uc_thread_count) {
		MALLOC(arg, struct nfsrv_uc_arg *, sizeof (struct nfsrv_uc_arg), M_NFSSVC, M_WAITOK | M_ZERO);
		if (arg == NULL)
			goto direct;

		slp->ns_ua = arg;
		arg->nua_slp = slp;
		arg->nua_qi = NFS_UC_HASH(slp);

		sock_setupcall(slp->ns_so, nfsrv_uc_proxy, arg);
	} else {
direct:
		slp->ns_ua = NULL;
		DPRINT("setting nfsrv_rcv up-call\n");
		sock_setupcall(slp->ns_so, nfsrv_rcv, slp);
	}

	/* just playin' it safe */
	sock_setsockopt(slp->ns_so, SOL_SOCKET, SO_UPCALLCLOSEWAIT, &on, sizeof(on));

	return;
}
Commit	Line	Data
316670eb A	1	/*
	2	* Copyright (c) 2011 Apple Inc. All rights reserved.
	3	*
	4	* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
	5	*
	6	* This file contains Original Code and/or Modifications of Original Code
	7	* as defined in and that are subject to the Apple Public Source License
	8	* Version 2.0 (the 'License'). You may not use this file except in
	9	* compliance with the License. The rights granted to you under the License
	10	* may not be used to create, or enable the creation or redistribution of,
	11	* unlawful or unlicensed copies of an Apple operating system, or to
	12	* circumvent, violate, or enable the circumvention or violation of, any
	13	* terms of an Apple operating system software license agreement.
	14	*
	15	* Please obtain a copy of the License at
	16	* http://www.opensource.apple.com/apsl/ and read it before using this file.
	17	*
	18	* The Original Code and all software distributed under the License are
	19	* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
	20	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
	21	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
	22	* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
	23	* Please see the License for the specific language governing rights and
	24	* limitations under the License.
	25	*
	26	* @APPLE_OSREFERENCE_LICENSE_HEADER_END@
	27	*/
	28	#include <stdint.h>
	29	#include <sys/param.h>
	30	#include <sys/mount_internal.h>
	31	#include <sys/malloc.h>
	32	#include <sys/queue.h>
	33
	34	#include <libkern/libkern.h>
	35	#include <libkern/OSAtomic.h>
	36	#include <kern/debug.h>
	37	#include <kern/thread.h>
	38
	39	#include <nfs/rpcv2.h>
	40	#include <nfs/nfsproto.h>
	41	#include <nfs/nfs.h>
	42
	43	#ifdef NFS_UC_DEBUG
	44	#define DPRINT(fmt, ...) printf(fmt,## __VA_ARGS__)
	45	#else
	46	#define DPRINT(fmt, ...)
	47	#endif
	48
	49	struct nfsrv_uc_arg {
	50	TAILQ_ENTRY(nfsrv_uc_arg) nua_svcq;
	51	socket_t nua_so;
	52	struct nfsrv_sock *nua_slp;
	53	int nua_waitflag; /* Should always be MBUF_DONTWAIT */
	54	uint32_t nua_flags;
	55	uint32_t nua_qi;
	56	};
	57	#define NFS_UC_QUEUED 0x0001
	58
	59	#define NFS_UC_HASH_SZ 7
	60	#define NFS_UC_HASH(x) ((((uint32_t)(uintptr_t)(x)) >> 3) % nfsrv_uc_thread_count)
	61
	62	TAILQ_HEAD(nfsrv_uc_q, nfsrv_uc_arg);
	63
	64	static struct nfsrv_uc_queue {
65	lck_mtx_t *ucq_lock;
66	struct nfsrv_uc_q ucq_queue[1];
67	thread_t ucq_thd;
68	uint32_t ucq_flags;
69	} nfsrv_uc_queue_tbl[NFS_UC_HASH_SZ];
70	#define NFS_UC_QUEUE_SLEEPING 0x0001
71
72	static lck_grp_t *nfsrv_uc_group;
73	static lck_mtx_t *nfsrv_uc_shutdown_lock;
74	static volatile int nfsrv_uc_shutdown = 0;
75	static int32_t nfsrv_uc_thread_count;
76
77	extern kern_return_t thread_terminate(thread_t);
78
79	#ifdef NFS_UC_Q_DEBUG
80	int nfsrv_uc_use_proxy = 1;
81	uint32_t nfsrv_uc_queue_limit;
82	uint32_t nfsrv_uc_queue_max_seen;
83	volatile uint32_t nfsrv_uc_queue_count;
84	#endif
85
86	/*
87	* Thread that dequeues up-calls and runs the nfsrv_rcv routine
88	*/
89	static void
90	nfsrv_uc_thread(void *arg, wait_result_t wr __unused)
91	{
92	int qi = (int)(uintptr_t)arg;
93	int error;
94	struct nfsrv_uc_arg *ep = NULL;
95	struct nfsrv_uc_queue *myqueue = &nfsrv_uc_queue_tbl[qi];
96
97	DPRINT("nfsrv_uc_thread %d started\n", qi);
98	while (!nfsrv_uc_shutdown) {
99	lck_mtx_lock(myqueue->ucq_lock);
100
101	while (!nfsrv_uc_shutdown && TAILQ_EMPTY(myqueue->ucq_queue)) {
102	myqueue->ucq_flags \|= NFS_UC_QUEUE_SLEEPING;
103	error = msleep(myqueue, myqueue->ucq_lock, PSOCK, "nfsd_upcall_handler", NULL);
104	myqueue->ucq_flags &= ~NFS_UC_QUEUE_SLEEPING;
105	if (error) {
106	printf("nfsrv_uc_thread received error %d\n", error);
107	}
108	}
109	if (nfsrv_uc_shutdown) {
110	lck_mtx_unlock(myqueue->ucq_lock);
111	break;
112	}
113
114
115	ep = TAILQ_FIRST(myqueue->ucq_queue);
116	DPRINT("nfsrv_uc_thread:%d dequeue %p from %p\n", qi, ep, myqueue);
117
118	TAILQ_REMOVE(myqueue->ucq_queue, ep, nua_svcq);
119
120	ep->nua_flags &= ~NFS_UC_QUEUED;
121
122	lck_mtx_unlock(myqueue->ucq_lock);
123
124	#ifdef NFS_UC_Q_DEBUG
125	OSDecrementAtomic(&nfsrv_uc_queue_count);
126	#endif
127
128	DPRINT("calling nfsrv_rcv for %p\n", (void *)ep->nua_slp);
129	nfsrv_rcv(ep->nua_so, (void *)ep->nua_slp, ep->nua_waitflag);
130	}
131
132	lck_mtx_lock(nfsrv_uc_shutdown_lock);
133	nfsrv_uc_thread_count--;
134	wakeup(&nfsrv_uc_thread_count);
135	lck_mtx_unlock(nfsrv_uc_shutdown_lock);
136
137	thread_terminate(current_thread());
138	}
139
140	/*
141	* Dequeue a closed nfsrv_sock if needed from the up-call queue.
142	* Call from nfsrv_zapsock
143	*/
144	void
145	nfsrv_uc_dequeue(struct nfsrv_sock *slp)
146	{
147	struct nfsrv_uc_arg *ap = slp->ns_ua;
148	struct nfsrv_uc_queue *myqueue = &nfsrv_uc_queue_tbl[ap->nua_qi];
149
150	/*
151	* We assume that the socket up-calls have been stop and the socket
152	* is shutting down so no need for acquiring the lock to check that
153	* the flag is cleared.
154	*/
155	if (ap == NULL \|\| (ap->nua_flags & NFS_UC_QUEUED) == 0)
156	return;
157	/* If we're queued we might race with nfsrv_uc_thread */
158	lck_mtx_lock(myqueue->ucq_lock);
159	if (ap->nua_flags & NFS_UC_QUEUED) {
160	printf("nfsrv_uc_dequeue remove %p\n", ap);
161	TAILQ_REMOVE(myqueue->ucq_queue, ap, nua_svcq);
162	ap->nua_flags &= ~NFS_UC_QUEUED;
163	#ifdef NFS_UC_Q_DEBUG
164	OSDecrementAtomic(&nfsrv_uc_queue_count);
165	#endif
166	}
167	lck_mtx_unlock(myqueue->ucq_lock);
168	}
169
170	/*
171	* Allocate and initialize globals for nfsrv_sock up-call support.
172	*/
173	void
174	nfsrv_uc_init(void)
175	{
176	int i;
177
178	nfsrv_uc_group = lck_grp_alloc_init("nfs_upcall_locks", LCK_GRP_ATTR_NULL);
179	for (i = 0; i < NFS_UC_HASH_SZ; i++) {
180	TAILQ_INIT(nfsrv_uc_queue_tbl[i].ucq_queue);
181	nfsrv_uc_queue_tbl[i].ucq_lock = lck_mtx_alloc_init(nfsrv_uc_group, LCK_ATTR_NULL);
182	nfsrv_uc_queue_tbl[i].ucq_thd = THREAD_NULL;
183	nfsrv_uc_queue_tbl[i].ucq_flags = 0;
184	}
185	nfsrv_uc_shutdown_lock = lck_mtx_alloc_init(nfsrv_uc_group, LCK_ATTR_NULL);
186	}
187
188	/*
189	* Start up-call threads to service nfsrv_sock(s)
190	* Called from the first call of nfsrv_uc_addsock
191	*/
192	static void
193	nfsrv_uc_start(void)
194	{
195	int32_t i;
196	int error;
197
198	#ifdef NFS_UC_Q_DEBUG
199	if (!nfsrv_uc_use_proxy)
200	return;
201	#endif
202	DPRINT("nfsrv_uc_start\n");
203
204	/* Wait until previous shutdown finishes */
205	lck_mtx_lock(nfsrv_uc_shutdown_lock);
206	while (nfsrv_uc_shutdown \|\| nfsrv_uc_thread_count > 0)
207	msleep(&nfsrv_uc_thread_count, nfsrv_uc_shutdown_lock, PSOCK, "nfsd_upcall_shutdown_wait", NULL);
208
209	/* Start up-call threads */
210	for (i = 0; i < NFS_UC_HASH_SZ; i++) {
211	error = kernel_thread_start(nfsrv_uc_thread, (void *)(uintptr_t)i, &nfsrv_uc_queue_tbl[nfsrv_uc_thread_count].ucq_thd);
212	if (!error) {
213	nfsrv_uc_thread_count++;
214	} else {
215	printf("nfsd: Could not start nfsrv_uc_thread: %d\n", error);
216	}
217	}
218	if (nfsrv_uc_thread_count == 0) {
219	printf("nfsd: Could not start nfsd proxy up-call service. Falling back\n");
220	goto out;
221	}
222
223	out:
224	#ifdef NFS_UC_Q_DEBUG
225	nfsrv_uc_queue_count = 0ULL;
226	nfsrv_uc_queue_max_seen = 0ULL;
227	#endif
228	lck_mtx_unlock(nfsrv_uc_shutdown_lock);
229	}
230
231	/*
232	* Stop the up-call threads.
233	* Called from nfsrv_uc_cleanup.
234	*/
235	static void
236	nfsrv_uc_stop(void)
237	{
238	int32_t i;
239	int32_t thread_count = nfsrv_uc_thread_count;
240
241	DPRINT("Entering nfsrv_uc_stop\n");
242
243	/* Signal up-call threads to stop */
244	nfsrv_uc_shutdown = 1;
245	for (i = 0; i < thread_count; i++) {
246	lck_mtx_lock(nfsrv_uc_queue_tbl[i].ucq_lock);
247	wakeup(&nfsrv_uc_queue_tbl[i]);
248	lck_mtx_unlock(nfsrv_uc_queue_tbl[i].ucq_lock);
249	}
250
251	/* Wait until they are done shutting down */
252	lck_mtx_lock(nfsrv_uc_shutdown_lock);
253	while (nfsrv_uc_thread_count > 0)
254	msleep(&nfsrv_uc_thread_count, nfsrv_uc_shutdown_lock, PSOCK, "nfsd_upcall_shutdown_stop", NULL);
255
256	/* Deallocate old threads */
257	for (i = 0; i < nfsrv_uc_thread_count; i++) {
258	if (nfsrv_uc_queue_tbl[i].ucq_thd != THREAD_NULL)
259	thread_deallocate(nfsrv_uc_queue_tbl[i].ucq_thd);
260	nfsrv_uc_queue_tbl[i].ucq_thd = THREAD_NULL;
261	}
262
263	/* Enable restarting */
264	nfsrv_uc_shutdown = 0;
265	lck_mtx_unlock(nfsrv_uc_shutdown_lock);
266	}
267
268	/*
269	* Shutdown up-calls for nfsrv_socks.
270	* Make sure nothing is queued on the up-call queues
271	* Shutdown the up-call threads
272	* Called from nfssvc_cleanup.
273	*/
274	void
275	nfsrv_uc_cleanup(void)
276	{
277	int i;
278
279	DPRINT("Entering nfsrv_uc_cleanup\n");
280
281	/*
282	* Every thing should be dequeued at this point or will be as sockets are closed
283	* but to be safe, we'll make sure.
284	*/
285	for (i = 0; i < NFS_UC_HASH_SZ; i++) {
286	struct nfsrv_uc_queue *queue = &nfsrv_uc_queue_tbl[i];
287
288	lck_mtx_lock(queue->ucq_lock);
289	while (!TAILQ_EMPTY(queue->ucq_queue)) {
290	struct nfsrv_uc_arg *ep = TAILQ_FIRST(queue->ucq_queue);
291	TAILQ_REMOVE(queue->ucq_queue, ep, nua_svcq);
292	ep->nua_flags &= ~NFS_UC_QUEUED;
293	}
294	lck_mtx_unlock(queue->ucq_lock);
295	}
296
297	nfsrv_uc_stop();
298	}
299
300	/*
301	* This is the nfs up-call routine for server sockets.
302	* We used to set nfsrv_rcv as the up-call routine, but
303	* recently that seems like we are doing to much work for
304	* the interface thread, so we just queue the arguments
305	* that we would have gotten for nfsrv_rcv and let a
306	* worker thread dequeue them and pass them on to nfsrv_rcv.
307	*/
308	static void
309	nfsrv_uc_proxy(socket_t so, void *arg, int waitflag)
310	{
311	struct nfsrv_uc_arg uap = (struct nfsrv_uc_arg )arg;
312	int qi = uap->nua_qi;
313	struct nfsrv_uc_queue *myqueue = &nfsrv_uc_queue_tbl[qi];
314
315	lck_mtx_lock(myqueue->ucq_lock);
316	DPRINT("nfsrv_uc_proxy called for %p (%p)\n", uap, uap->nua_slp);
317	DPRINT("\tUp-call queued on %d for wakeup of %p\n", qi, myqueue);
318	if (uap->nua_flags & NFS_UC_QUEUED) {
319	lck_mtx_unlock(myqueue->ucq_lock);
320	return; /* Already queued */
321	}
322
323	uap->nua_so = so;
324	uap->nua_waitflag = waitflag;
325
326	TAILQ_INSERT_TAIL(myqueue->ucq_queue, uap, nua_svcq);
327
328	uap->nua_flags \|= NFS_UC_QUEUED;
329	if (myqueue->ucq_flags \| NFS_UC_QUEUE_SLEEPING)
330	wakeup(myqueue);
331
332	#ifdef NFS_UC_Q_DEBUG
333	{
334	uint32_t count = OSIncrementAtomic(&nfsrv_uc_queue_count);
335
336	/* This is a bit racey but just for debug */
337	if (count > nfsrv_uc_queue_max_seen)
338	nfsrv_uc_queue_max_seen = count;
339
340	if (nfsrv_uc_queue_limit && count > nfsrv_uc_queue_limit) {
341	panic("nfsd up-call queue limit exceeded\n");
342	}
343	}
344	#endif
345	lck_mtx_unlock(myqueue->ucq_lock);
346	}
347
348
349	/*
350	* Set the up-call routine on the socket associated with the passed in
351	* nfsrv_sock.
352	* Assumes nfsd_mutex is held.
353	*/
354	void
355	nfsrv_uc_addsock(struct nfsrv_sock *slp, int start)
356	{
357	int on = 1;
358	struct nfsrv_uc_arg *arg;
359
360	if (start && nfsrv_uc_thread_count == 0)
361	nfsrv_uc_start();
362
363	/*
364	* We don't take a lock since once we're up nfsrv_uc_thread_count does
365	* not change until shutdown and then we should not be adding sockets to
366	* generate up-calls.
367	*/
368	if (nfsrv_uc_thread_count) {
369	MALLOC(arg, struct nfsrv_uc_arg *, sizeof (struct nfsrv_uc_arg), M_NFSSVC, M_WAITOK \| M_ZERO);
370	if (arg == NULL)
371	goto direct;
372
373	slp->ns_ua = arg;
374	arg->nua_slp = slp;
375	arg->nua_qi = NFS_UC_HASH(slp);
376
377	sock_setupcall(slp->ns_so, nfsrv_uc_proxy, arg);
378	} else {
379	direct:
380	slp->ns_ua = NULL;
381	DPRINT("setting nfsrv_rcv up-call\n");
382	sock_setupcall(slp->ns_so, nfsrv_rcv, slp);
383	}
384
385	/* just playin' it safe */
386	sock_setsockopt(slp->ns_so, SOL_SOCKET, SO_UPCALLCLOSEWAIT, &on, sizeof(on));
387
388	return;
389	}
390