nfs_syscalls.c

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Author : ratchov
Date : 2024-01-12 08:47:46
Hash : 58a52142
Message : nfssvc: When the client disconnects, close the socket before sleeping. If the server doesn't close the socket immediately and starts waiting for the client to reconnect, then the TCP connection will remain open. The client will have to wait for the connection to be closed in order to reconnect with the same source port; this never happens, resulting in a freeze until the file system is umounted. This change fixes Linux NFS clients freezing after 5 min of inactivity. ok miod, help from claudio
sys/nfs/nfs_syscalls.c
/*	$OpenBSD: nfs_syscalls.c,v 1.120 2024/01/12 08:47:46 ratchov Exp $	*/
/*	$NetBSD: nfs_syscalls.c,v 1.19 1996/02/18 11:53:52 fvdl Exp $	*/

/*
 * Copyright (c) 1989, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Rick Macklem at The University of Guelph.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *	@(#)nfs_syscalls.c	8.5 (Berkeley) 3/30/95
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/file.h>
#include <sys/stat.h>
#include <sys/vnode.h>
#include <sys/mount.h>
#include <sys/pool.h>
#include <sys/proc.h>
#include <sys/uio.h>
#include <sys/malloc.h>
#include <sys/buf.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/domain.h>
#include <sys/protosw.h>
#include <sys/namei.h>
#include <sys/syslog.h>
#include <sys/filedesc.h>
#include <sys/signalvar.h>
#include <sys/kthread.h>
#include <sys/queue.h>

#include <sys/syscallargs.h>

#include <netinet/in.h>
#include <netinet/tcp.h>
#include <nfs/xdr_subs.h>
#include <nfs/rpcv2.h>
#include <nfs/nfsproto.h>
#include <nfs/nfs.h>
#include <nfs/nfsrvcache.h>
#include <nfs/nfsmount.h>
#include <nfs/nfsnode.h>
#include <nfs/nfs_var.h>

/* Global defs. */
extern int nfs_numasync;
extern struct nfsstats nfsstats;
struct nfssvc_sock *nfs_udpsock;
int nfsd_waiting = 0;

#ifdef NFSSERVER
struct pool nfsrv_descript_pl;

int nfsrv_getslp(struct nfsd *nfsd);

static int nfs_numnfsd = 0;
int (*nfsrv3_procs[NFS_NPROCS])(struct nfsrv_descript *,
    struct nfssvc_sock *, struct proc *, struct mbuf **) = {
	nfsrv_null,
	nfsrv_getattr,
	nfsrv_setattr,
	nfsrv_lookup,
	nfsrv3_access,
	nfsrv_readlink,
	nfsrv_read,
	nfsrv_write,
	nfsrv_create,
	nfsrv_mkdir,
	nfsrv_symlink,
	nfsrv_mknod,
	nfsrv_remove,
	nfsrv_rmdir,
	nfsrv_rename,
	nfsrv_link,
	nfsrv_readdir,
	nfsrv_readdirplus,
	nfsrv_statfs,
	nfsrv_fsinfo,
	nfsrv_pathconf,
	nfsrv_commit,
	nfsrv_noop
};
#endif

TAILQ_HEAD(, nfssvc_sock) nfssvc_sockhead;
struct nfsdhead nfsd_head;

int nfssvc_sockhead_flag;
#define	SLP_INIT	0x01	/* NFS data undergoing initialization */
#define	SLP_WANTINIT	0x02	/* thread waiting on NFS initialization */
int nfsd_head_flag;

#ifdef NFSCLIENT
struct proc *nfs_asyncdaemon[NFS_MAXASYNCDAEMON];
int nfs_niothreads = -1;
#endif

int nfssvc_addsock(struct file *, struct mbuf *);
int nfssvc_nfsd(struct nfsd *);
void nfsrv_slpderef(struct nfssvc_sock *);
void nfsrv_zapsock(struct nfssvc_sock *);
void nfssvc_iod(void *);

/*
 * NFS server pseudo system call for the nfsd's
 * Based on the flag value it either:
 * - adds a socket to the selection list
 * - remains in the kernel as an nfsd
 */
int
sys_nfssvc(struct proc *p, void *v, register_t *retval)
{
	int error = 0;
#ifdef NFSSERVER
	struct sys_nfssvc_args /* {
		syscallarg(int) flag;
		syscallarg(caddr_t) argp;
	} */ *uap = v;
	int flags = SCARG(uap, flag);
	struct file *fp;
	struct mbuf *nam;
	struct nfsd_args nfsdarg;
	struct nfsd_srvargs nfsd_srvargs, *nsd = &nfsd_srvargs;
	struct nfsd *nfsd;
#endif

	/* Must be super user */
	error = suser(p);
	if (error)
		return (error);

#ifndef NFSSERVER
	error = ENOSYS;
#else

	while (nfssvc_sockhead_flag & SLP_INIT) {
		nfssvc_sockhead_flag |= SLP_WANTINIT;
		tsleep_nsec(&nfssvc_sockhead, PSOCK, "nfsd init", INFSLP);
	}

	switch (flags) {
	case NFSSVC_ADDSOCK:
		error = copyin(SCARG(uap, argp), &nfsdarg, sizeof(nfsdarg));
		if (error)
			return (error);

		error = getsock(p, nfsdarg.sock, &fp);
		if (error)
			return (error);

		/*
		 * Get the client address for connected sockets.
		 */
		if (nfsdarg.name == NULL || nfsdarg.namelen == 0)
			nam = NULL;
		else {
			error = sockargs(&nam, nfsdarg.name, nfsdarg.namelen,
				MT_SONAME);
			if (error) {
				FRELE(fp, p);
				return (error);
			}
		}
		error = nfssvc_addsock(fp, nam);
		FRELE(fp, p);
		break;
	case NFSSVC_NFSD:
		error = copyin(SCARG(uap, argp), nsd, sizeof(*nsd));
		if (error)
			return (error);

		nfsd = malloc(sizeof(*nfsd), M_NFSD, M_WAITOK|M_ZERO);
		nfsd->nfsd_procp = p;
		nfsd->nfsd_slp = NULL;

		error = nfssvc_nfsd(nfsd);
		break;
	default:
		error = EINVAL;
		break;
	}

	if (error == EINTR || error == ERESTART)
		error = 0;
#endif	/* !NFSSERVER */

	return (error);
}

#ifdef NFSSERVER
/*
 * Adds a socket to the list for servicing by nfsds.
 */
int
nfssvc_addsock(struct file *fp, struct mbuf *mynam)
{
	struct mbuf *m;
	int siz;
	struct nfssvc_sock *slp;
	struct socket *so;
	struct nfssvc_sock *tslp;
	int error;

	so = (struct socket *)fp->f_data;
	tslp = NULL;
	/*
	 * Add it to the list, as required.
	 */
	if (so->so_proto->pr_protocol == IPPROTO_UDP) {
		tslp = nfs_udpsock;
		if (tslp->ns_flag & SLP_VALID) {
			m_freem(mynam);
			return (EPERM);
		}
	}
	if (so->so_type == SOCK_STREAM)
		siz = NFS_MAXPACKET + sizeof (u_long);
	else
		siz = NFS_MAXPACKET;
	solock(so);
	error = soreserve(so, siz, siz); 
	sounlock(so);
	if (error) {
		m_freem(mynam);
		return (error);
	}

	/*
	 * Set protocol specific options { for now TCP only } and
	 * reserve some space. For datagram sockets, this can get called
	 * repeatedly for the same socket, but that isn't harmful.
	 */
	if (so->so_type == SOCK_STREAM) {
		MGET(m, M_WAIT, MT_SOOPTS);
		*mtod(m, int32_t *) = 1;
		m->m_len = sizeof(int32_t);
		sosetopt(so, SOL_SOCKET, SO_KEEPALIVE, m);
		m_freem(m);
	}
	if (so->so_proto->pr_domain->dom_family == AF_INET &&
	    so->so_proto->pr_protocol == IPPROTO_TCP) {
		MGET(m, M_WAIT, MT_SOOPTS);
		*mtod(m, int32_t *) = 1;
		m->m_len = sizeof(int32_t);
		sosetopt(so, IPPROTO_TCP, TCP_NODELAY, m);
		m_freem(m);
	}
	solock(so);
	so->so_rcv.sb_flags &= ~SB_NOINTR;
	so->so_rcv.sb_timeo_nsecs = INFSLP;
	so->so_snd.sb_flags &= ~SB_NOINTR;
	so->so_snd.sb_timeo_nsecs = INFSLP;
	sounlock(so);
	if (tslp)
		slp = tslp;
	else {
		slp = malloc(sizeof(*slp), M_NFSSVC, M_WAITOK|M_ZERO);
		TAILQ_INSERT_TAIL(&nfssvc_sockhead, slp, ns_chain);
	}
	slp->ns_so = so;
	slp->ns_nam = mynam;
	FREF(fp);
	slp->ns_fp = fp;
	so->so_upcallarg = (caddr_t)slp;
	so->so_upcall = nfsrv_rcv;
	slp->ns_flag = (SLP_VALID | SLP_NEEDQ);
	nfsrv_wakenfsd(slp);
	return (0);
}

/*
 * Called by nfssvc() for nfsds. Just loops around servicing rpc requests
 * until it is killed by a signal.
 */
int
nfssvc_nfsd(struct nfsd *nfsd)
{
	struct mbuf *m;
	int siz;
	struct nfssvc_sock *slp;
	struct socket *so;
	int *solockp;
	struct nfsrv_descript *nd = NULL;
	struct mbuf *mreq;
	int error = 0, cacherep, sotype;

	cacherep = RC_DOIT;

	TAILQ_INSERT_TAIL(&nfsd_head, nfsd, nfsd_chain);
	nfs_numnfsd++;

	/* Loop getting rpc requests until SIGKILL. */
loop:
	if (!ISSET(nfsd->nfsd_flag, NFSD_REQINPROG)) {

		/* attach an nfssvc_sock to nfsd */
		error = nfsrv_getslp(nfsd);
		if (error)
			goto done;

		slp = nfsd->nfsd_slp;

		if (ISSET(slp->ns_flag, SLP_VALID)) {
			if ((slp->ns_flag & (SLP_DISCONN | SLP_NEEDQ)) ==
			    SLP_NEEDQ) {
				CLR(slp->ns_flag, SLP_NEEDQ);
				nfs_sndlock(&slp->ns_solock, NULL);
				nfsrv_rcv(slp->ns_so, (caddr_t)slp, M_WAIT);
				nfs_sndunlock(&slp->ns_solock);
			}
			if (ISSET(slp->ns_flag, SLP_DISCONN))
				nfsrv_zapsock(slp);

			error = nfsrv_dorec(slp, nfsd, &nd);
			SET(nfsd->nfsd_flag, NFSD_REQINPROG);
		}
	} else {
		error = 0;
		slp = nfsd->nfsd_slp;
	}

	if (error || !ISSET(slp->ns_flag, SLP_VALID)) {
		if (nd != NULL) {
			pool_put(&nfsrv_descript_pl, nd);
			nd = NULL;
		}
		nfsd->nfsd_slp = NULL;
		CLR(nfsd->nfsd_flag, NFSD_REQINPROG);
		nfsrv_slpderef(slp);
		goto loop;
	}

	so = slp->ns_so;
	sotype = so->so_type;
	if (ISSET(so->so_proto->pr_flags, PR_CONNREQUIRED))
		solockp = &slp->ns_solock;
	else
		solockp = NULL;

	if (nd) {
		if (nd->nd_nam2)
			nd->nd_nam = nd->nd_nam2;
		else
			nd->nd_nam = slp->ns_nam;
	}

	cacherep = nfsrv_getcache(nd, slp, &mreq);
	switch (cacherep) {
	case RC_DOIT:
		error = (*(nfsrv3_procs[nd->nd_procnum]))(nd, slp, nfsd->nfsd_procp, &mreq);
		if (mreq == NULL) {
			if (nd != NULL) {
				m_freem(nd->nd_nam2);
				m_freem(nd->nd_mrep);
			}
			break;
		}
		if (error) {
			nfsstats.srv_errs++;
			nfsrv_updatecache(nd, 0, mreq);
			m_freem(nd->nd_nam2);
			break;
		}
		nfsstats.srvrpccnt[nd->nd_procnum]++;
		nfsrv_updatecache(nd, 1, mreq);
		nd->nd_mrep = NULL;

		/* FALLTHROUGH */
	case RC_REPLY:
		m = mreq;
		siz = 0;
		while (m) {
			siz += m->m_len;
			m = m->m_next;
		}

		if (siz <= 0 || siz > NFS_MAXPACKET)
			panic("bad nfs svc reply, siz = %i", siz);

		m = mreq;
		m->m_pkthdr.len = siz;
		m->m_pkthdr.ph_ifidx = 0;

		/* For stream protocols, prepend a Sun RPC Record Mark. */
		if (sotype == SOCK_STREAM) {
			M_PREPEND(m, NFSX_UNSIGNED, M_WAIT);
			*mtod(m, u_int32_t *) = htonl(0x80000000 | siz);
		}

		if (solockp)
			nfs_sndlock(solockp, NULL);

		if (ISSET(slp->ns_flag, SLP_VALID))
		    error = nfs_send(so, nd->nd_nam2, m, NULL);
		else {
		    error = EPIPE;
		    m_freem(m);
		}
		m_freem(nd->nd_nam2);
		m_freem(nd->nd_mrep);
		if (error == EPIPE)
			nfsrv_zapsock(slp);
		if (solockp)
			nfs_sndunlock(solockp);
		if (error == EINTR || error == ERESTART) {
			pool_put(&nfsrv_descript_pl, nd);
			nfsrv_slpderef(slp);
			goto done;
		}
		break;
	case RC_DROPIT:
		m_freem(nd->nd_mrep);
		m_freem(nd->nd_nam2);
		break;
	};

	if (nd) {
		pool_put(&nfsrv_descript_pl, nd);
		nd = NULL;
	}

	if (nfsrv_dorec(slp, nfsd, &nd)) {
		nfsd->nfsd_flag &= ~NFSD_REQINPROG;
		nfsd->nfsd_slp = NULL;
		nfsrv_slpderef(slp);
	}
	goto loop;

done:
	TAILQ_REMOVE(&nfsd_head, nfsd, nfsd_chain);
	free(nfsd, M_NFSD, sizeof(*nfsd));
	if (--nfs_numnfsd == 0)
		nfsrv_init(1);	/* Reinitialize everything */
	return (error);
}

/*
 * Shut down a socket associated with an nfssvc_sock structure.
 * Should be called with the send lock set, if required.
 * The trick here is to increment the sref at the start, so that the nfsds
 * will stop using it and clear ns_flag at the end so that it will not be
 * reassigned during cleanup.
 */
void
nfsrv_zapsock(struct nfssvc_sock *slp)
{
	struct socket *so;
	struct file *fp;
	struct mbuf *m, *n;

	slp->ns_flag &= ~SLP_ALLFLAGS;
	fp = slp->ns_fp;
	if (fp) {
		FREF(fp);
		slp->ns_fp = NULL;
		so = slp->ns_so;
		so->so_upcall = NULL;
		soshutdown(so, SHUT_RDWR);
		closef(fp, NULL);
		if (slp->ns_nam)
	    		m = m_free(slp->ns_nam);
		m_freem(slp->ns_raw);
		m = slp->ns_rec;
		while (m) {
			n = m->m_nextpkt;
			m_freem(m);
			m = n;
		}
	}
}

/*
 * Dereference a server socket structure. If it has no more references and
 * is no longer valid, you can throw it away.
 */
void
nfsrv_slpderef(struct nfssvc_sock *slp)
{
	if (--(slp->ns_sref) == 0 && (slp->ns_flag & SLP_VALID) == 0) {
		TAILQ_REMOVE(&nfssvc_sockhead, slp, ns_chain);
		free(slp, M_NFSSVC, sizeof(*slp));
	}
}

/*
 * Initialize the data structures for the server.
 * Handshake with any new nfsds starting up to avoid any chance of
 * corruption.
 */
void
nfsrv_init(int terminating)
{
	struct nfssvc_sock *slp, *nslp;

	if (nfssvc_sockhead_flag & SLP_INIT)
		panic("nfsd init");
	nfssvc_sockhead_flag |= SLP_INIT;
	if (terminating) {
		for (slp = TAILQ_FIRST(&nfssvc_sockhead); slp != NULL;
		    slp = nslp) {
			nslp = TAILQ_NEXT(slp, ns_chain);
			if (slp->ns_flag & SLP_VALID)
				nfsrv_zapsock(slp);
			TAILQ_REMOVE(&nfssvc_sockhead, slp, ns_chain);
			free(slp, M_NFSSVC, sizeof(*slp));
		}
		nfsrv_cleancache();	/* And clear out server cache */
	}

	TAILQ_INIT(&nfssvc_sockhead);
	nfssvc_sockhead_flag &= ~SLP_INIT;
	if (nfssvc_sockhead_flag & SLP_WANTINIT) {
		nfssvc_sockhead_flag &= ~SLP_WANTINIT;
		wakeup((caddr_t)&nfssvc_sockhead);
	}

	TAILQ_INIT(&nfsd_head);
	nfsd_head_flag &= ~NFSD_CHECKSLP;

	nfs_udpsock =  malloc(sizeof(*nfs_udpsock), M_NFSSVC,
	    M_WAITOK|M_ZERO);
	TAILQ_INSERT_HEAD(&nfssvc_sockhead, nfs_udpsock, ns_chain);

	if (!terminating) {
		pool_init(&nfsrv_descript_pl, sizeof(struct nfsrv_descript),
		    0, IPL_NONE, PR_WAITOK, "ndscpl", NULL);
	}
}
#endif /* NFSSERVER */

#ifdef NFSCLIENT
/*
 * Asynchronous I/O threads for client nfs.
 * They do read-ahead and write-behind operations on the block I/O cache.
 * Never returns unless it fails or gets killed.
 */
void
nfssvc_iod(void *arg)
{
	struct proc *p = curproc;
	struct buf *bp, *nbp;
	int i, myiod;
	struct vnode *vp;
	int error = 0, s, bufcount;

	bufcount = MIN(256, bcstats.kvaslots / 8);
	bufcount = MIN(bufcount, bcstats.numbufs / 8);

	/* Assign my position or return error if too many already running. */
	myiod = -1;
	for (i = 0; i < NFS_MAXASYNCDAEMON; i++) {
		if (nfs_asyncdaemon[i] == NULL) {
			myiod = i;
			break;
		}
	}
	if (myiod == -1)
		kthread_exit(EBUSY);

	nfs_asyncdaemon[myiod] = p;
	nfs_numasync++;

	/* Upper limit on how many bufs we'll queue up for this iod. */
	if (nfs_bufqmax > bcstats.kvaslots / 4) {
		nfs_bufqmax = bcstats.kvaslots / 4;
		bufcount = 0;
	} 
	if (nfs_bufqmax > bcstats.numbufs / 4) {
		nfs_bufqmax = bcstats.numbufs / 4;
		bufcount = 0;
	}

	nfs_bufqmax += bufcount;
	wakeup(&nfs_bufqlen); /* wake up anyone waiting for room to enqueue IO */

	/* Just loop around doin our stuff until SIGKILL. */
	for (;;) {
	    while (TAILQ_FIRST(&nfs_bufq) == NULL && error == 0) {
		    error = tsleep_nsec(&nfs_bufq,
			PWAIT | PCATCH, "nfsidl", INFSLP);
	    }
	    while ((bp = TAILQ_FIRST(&nfs_bufq)) != NULL) {
		/* Take one off the front of the list */
		TAILQ_REMOVE(&nfs_bufq, bp, b_freelist);
		nfs_bufqlen--;
		wakeup_one(&nfs_bufqlen);
		if (bp->b_flags & B_READ)
		    (void) nfs_doio(bp, NULL);
		else do {
		    /*
		     * Look for a delayed write for the same vnode, so I can do 
		     * it now. We must grab it before calling nfs_doio() to
		     * avoid any risk of the vnode getting vclean()'d while
		     * we are doing the write rpc.
		     */
		    vp = bp->b_vp;
		    s = splbio();
		    LIST_FOREACH(nbp, &vp->v_dirtyblkhd, b_vnbufs) {
			if ((nbp->b_flags &
			    (B_BUSY|B_DELWRI|B_NEEDCOMMIT|B_NOCACHE))!=B_DELWRI)
			    continue;
			nbp->b_flags |= B_ASYNC;
			bremfree(nbp);
			buf_acquire(nbp);
			break;
		    }
		    /*
		     * For the delayed write, do the first part of nfs_bwrite()
		     * up to, but not including nfs_strategy().
		     */
		    if (nbp) {
			nbp->b_flags &= ~(B_READ|B_DONE|B_ERROR);
			buf_undirty(nbp);
			nbp->b_vp->v_numoutput++;
		    }
		    splx(s);

		    (void) nfs_doio(bp, NULL);
		} while ((bp = nbp) != NULL);
	    }
	    if (error) {
		nfs_asyncdaemon[myiod] = NULL;
		nfs_numasync--;
		nfs_bufqmax -= bufcount;
		kthread_exit(error);
	    }
	}
}

void
nfs_getset_niothreads(int set)
{
	int i, have, start;
	
	for (have = 0, i = 0; i < NFS_MAXASYNCDAEMON; i++)
		if (nfs_asyncdaemon[i] != NULL)
			have++;

	if (set) {
		/* clamp to sane range */
		nfs_niothreads = max(0, min(nfs_niothreads, NFS_MAXASYNCDAEMON));

		start = nfs_niothreads - have;

		while (start > 0) {
			kthread_create(nfssvc_iod, NULL, NULL, "nfsio");
			start--;
		}

		for (i = 0; (start < 0) && (i < NFS_MAXASYNCDAEMON); i++)
			if (nfs_asyncdaemon[i] != NULL) {
				psignal(nfs_asyncdaemon[i], SIGKILL);
				start++;
			}
	} else {
		if (nfs_niothreads >= 0)
			nfs_niothreads = have;
	}
}
#endif /* NFSCLIENT */

#ifdef NFSSERVER
/*
 * Find an nfssrv_sock for nfsd, sleeping if needed.
 */
int
nfsrv_getslp(struct nfsd *nfsd)
{
	struct nfssvc_sock *slp;
	int error;

again:
	while (nfsd->nfsd_slp == NULL &&
	    (nfsd_head_flag & NFSD_CHECKSLP) == 0) {
		nfsd->nfsd_flag |= NFSD_WAITING;
		nfsd_waiting++;
		error = tsleep_nsec(nfsd, PSOCK | PCATCH, "nfsd", INFSLP);
		nfsd_waiting--;
		if (error)
			return (error);
	}

	if (nfsd->nfsd_slp == NULL &&
	    (nfsd_head_flag & NFSD_CHECKSLP) != 0) {
		TAILQ_FOREACH(slp, &nfssvc_sockhead, ns_chain) {
			if ((slp->ns_flag & (SLP_VALID | SLP_DOREC)) ==
			    (SLP_VALID | SLP_DOREC)) {
				slp->ns_flag &= ~SLP_DOREC;
				slp->ns_sref++;
				nfsd->nfsd_slp = slp;
				break;
			}
		}
		if (slp == NULL)
			nfsd_head_flag &= ~NFSD_CHECKSLP;
	}

	if (nfsd->nfsd_slp == NULL)
		goto again;

	return (0);
}
#endif /* NFSSERVER */
IABSD.fr/src/sys/nfs/nfs_syscalls.c

Commit

IABSD.fr/src /sys/nfs/nfs_syscalls.c
