[unix-history] / sys / nfs / nfs_syscalls.c

/*
 * Copyright (c) 1989 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. 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.
 *
 *	From:	@(#)nfs_syscalls.c	7.26 (Berkeley) 4/16/91
 *	$Id$
 */

#include "param.h"
#include "systm.h"
#include "kernel.h"
#include "file.h"
#include "stat.h"
#include "namei.h"
#include "vnode.h"
#include "mount.h"
#include "proc.h"
#include "malloc.h"
#include "buf.h"
#include "mbuf.h"
#include "socket.h"
#include "socketvar.h"
#include "domain.h"
#include "protosw.h"

#include "../netinet/in.h"
#include "../netinet/tcp.h"

#include "nfsv2.h"
#include "nfs.h"
#include "nfsrvcache.h"

/* Global defs. */
extern u_long nfs_prog, nfs_vers;
extern int (*nfsrv_procs[NFS_NPROCS])();
extern struct buf nfs_bqueue;
extern int nfs_numasync;
extern struct proc *nfs_iodwant[NFS_MAXASYNCDAEMON];
extern int nfs_tcpnodelay;
struct mbuf *nfs_compress();

#define	TRUE	1
#define	FALSE	0

static int nfs_asyncdaemon[NFS_MAXASYNCDAEMON];
static int compressreply[NFS_NPROCS] = {
	FALSE,
	TRUE,
	TRUE,
	FALSE,
	TRUE,
	TRUE,
	FALSE,
	FALSE,
	TRUE,
	TRUE,
	TRUE,
	TRUE,
	TRUE,
	TRUE,
	TRUE,
	TRUE,
	TRUE,
	TRUE,
};
/*
 * NFS server system calls
 * getfh() lives here too, but maybe should move to kern/vfs_syscalls.c
 */

/*
 * Get file handle system call
 */

struct getfh_args {
	char	*fname;
	fhandle_t *fhp;
};

/* ARGSUSED */
int
getfh(p, uap, retval)
	struct proc *p;
	register struct getfh_args *uap;
	int *retval;
{
	register struct nameidata *ndp;
	register struct vnode *vp;
	fhandle_t fh;
	int error;
	struct nameidata nd;

	/*
	 * Must be super user
	 */
	if (error = suser(p->p_ucred, &p->p_acflag))
		return (error);
	ndp = &nd;
	ndp->ni_nameiop = LOOKUP | LOCKLEAF | FOLLOW;
	ndp->ni_segflg = UIO_USERSPACE;
	ndp->ni_dirp = uap->fname;
	if (error = namei(ndp, p))
		return (error);
	vp = ndp->ni_vp;
	bzero((caddr_t)&fh, sizeof(fh));
	fh.fh_fsid = vp->v_mount->mnt_stat.f_fsid;
	error = VFS_VPTOFH(vp, &fh.fh_fid);
	vput(vp);
	if (error)
		return (error);
	error = copyout((caddr_t)&fh, (caddr_t)uap->fhp, sizeof (fh));
	return (error);
}

/*
 * Nfs server psuedo system call for the nfsd's
 * Never returns unless it fails or gets killed
 */

struct nfssvc_args {
	int s;
	caddr_t mskval;
	int msklen;
	caddr_t mtchval;
	int mtchlen;
};

/* ARGSUSED */
int
nfssvc(p, uap, retval)
	struct proc *p;
	register struct nfssvc_args *uap;
	int *retval;
{
	register struct mbuf *m;
	register int siz;
	register struct ucred *cr;
	struct file *fp;
	struct mbuf *mreq, *mrep, *nam, *md;
	struct mbuf msk, mtch;
	struct socket *so;
	caddr_t dpos;
	int procid, repstat, error, cacherep, wascomp;
	u_long retxid;

	/*
	 * Must be super user
	 */
	if (error = suser(p->p_ucred, &p->p_acflag))
		return (error);
	if (error = getsock(p->p_fd, uap->s, &fp))
		return (error);
	so = (struct socket *)fp->f_data;
	if (sosendallatonce(so))
		siz = NFS_MAXPACKET;
	else
		siz = NFS_MAXPACKET + sizeof(u_long);
	if (error = soreserve(so, siz, siz))
		goto bad;
	if (error = sockargs(&nam, uap->mskval, uap->msklen, MT_SONAME))
		goto bad;
	bcopy((caddr_t)nam, (caddr_t)&msk, sizeof (struct mbuf));
	msk.m_data = msk.m_dat;
	m_freem(nam);
	if (error = sockargs(&nam, uap->mtchval, uap->mtchlen, MT_SONAME))
		goto bad;
	bcopy((caddr_t)nam, (caddr_t)&mtch, sizeof (struct mbuf));
	mtch.m_data = mtch.m_dat;
	m_freem(nam);

	/* Copy the cred so others don't see changes */
	cr = p->p_ucred = crcopy(p->p_ucred);

	/*
	 * 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_proto->pr_flags & PR_CONNREQUIRED) {
		MGET(m, M_WAIT, MT_SOOPTS);
		*mtod(m, int *) = 1;
		m->m_len = sizeof(int);
		sosetopt(so, SOL_SOCKET, SO_KEEPALIVE, m);
	}
	if (so->so_proto->pr_domain->dom_family == AF_INET &&
	    so->so_proto->pr_protocol == IPPROTO_TCP &&
	    nfs_tcpnodelay) {
		MGET(m, M_WAIT, MT_SOOPTS);
		*mtod(m, int *) = 1;
		m->m_len = sizeof(int);
		sosetopt(so, IPPROTO_TCP, TCP_NODELAY, m);
	}
	so->so_rcv.sb_flags &= ~SB_NOINTR;
	so->so_rcv.sb_timeo = 0;
	so->so_snd.sb_flags &= ~SB_NOINTR;
	so->so_snd.sb_timeo = 0;

	/*
	 * Just loop around doin our stuff until SIGKILL
	 */
	for (;;) {
		if (error = nfs_getreq(so, nfs_prog, nfs_vers, NFS_NPROCS-1,
		   &nam, &mrep, &md, &dpos, &retxid, &procid, cr,
/* 08 Sep 92*/	   &msk, &mtch, &wascomp, &repstat)) {
			if (nam)
				m_freem(nam);
			if (error == EPIPE || error == EINTR ||
			    error == ERESTART) {
				error = 0;
				goto bad;
			}
			so->so_error = 0;
			continue;
		}

		if (nam)
			cacherep = nfsrv_getcache(nam, retxid, procid, &mreq);
		else
			cacherep = RC_DOIT;
		switch (cacherep) {
		case RC_DOIT:
			if (error = (*(nfsrv_procs[procid]))(mrep, md, dpos,
				cr, retxid, &mreq, &repstat, p)) {
				nfsstats.srv_errs++;
				if (nam) {
					nfsrv_updatecache(nam, retxid, procid,
						FALSE, repstat, mreq);
					m_freem(nam);
				}
				break;
			}
			nfsstats.srvrpccnt[procid]++;
			if (nam)
				nfsrv_updatecache(nam, retxid, procid, TRUE,
					repstat, mreq);
			mrep = (struct mbuf *)0;
		case RC_REPLY:
			m = mreq;
			siz = 0;
			while (m) {
				siz += m->m_len;
				m = m->m_next;
			}
			if (siz <= 0 || siz > NFS_MAXPACKET) {
				printf("mbuf siz=%d\n",siz);
				panic("Bad nfs svc reply");
			}
			mreq->m_pkthdr.len = siz;
			mreq->m_pkthdr.rcvif = (struct ifnet *)0;
			if (wascomp && compressreply[procid]) {
				mreq = nfs_compress(mreq);
				siz = mreq->m_pkthdr.len;
			}
			/*
			 * For non-atomic protocols, prepend a Sun RPC
			 * Record Mark.
			 */
			if (!sosendallatonce(so)) {
				M_PREPEND(mreq, sizeof(u_long), M_WAIT);
				*mtod(mreq, u_long *) = htonl(0x80000000 | siz);
			}
			error = nfs_send(so, nam, mreq, (struct nfsreq *)0);
			if (nam)
				m_freem(nam);
			if (mrep)
				m_freem(mrep);
			if (error) {
				if (error == EPIPE || error == EINTR ||
				    error == ERESTART)
					goto bad;
				so->so_error = 0;
			}
			break;
		case RC_DROPIT:
			m_freem(mrep);
			m_freem(nam);
			break;
		};
	}
bad:
	return (error);
}

/*
 * Nfs pseudo system call for asynchronous i/o daemons.
 * These babies just pretend to be disk interrupt service routines
 * for client nfs. They are mainly here for read ahead/write behind.
 * Never returns unless it fails or gets killed
 */
/* ARGSUSED */
int
async_daemon(p, uap, retval)
	struct proc *p;
	struct args *uap;
	int *retval;
{
	register struct buf *bp, *dp;
	register int i, myiod;
	int error;

	/*
	 * Must be super user
	 */
	if (error = suser(p->p_ucred, &p->p_acflag))
		return (error);
	/*
	 * Assign my position or return error if too many already running
	 */
	myiod = -1;
	for (i = 0; i < NFS_MAXASYNCDAEMON; i++)
		if (nfs_asyncdaemon[i] == 0) {
			nfs_asyncdaemon[i]++;
			myiod = i;
			break;
		}
	if (myiod == -1)
		return (EBUSY);
	nfs_numasync++;
	dp = &nfs_bqueue;
	/*
	 * Just loop around doin our stuff until SIGKILL
	 */
	for (;;) {
		while (dp->b_actf == NULL && error == 0) {
			nfs_iodwant[myiod] = p;
			error = tsleep((caddr_t)&nfs_iodwant[myiod],
				PWAIT | PCATCH, "nfsidl", 0);
			nfs_iodwant[myiod] = (struct proc *)0;
		}
		while (dp->b_actf != NULL) {
			/* Take one off the end of the list */
			bp = dp->b_actl;
			if (bp->b_actl == dp) {
				dp->b_actf = dp->b_actl = (struct buf *)0;
			} else {
				dp->b_actl = bp->b_actl;
				bp->b_actl->b_actf = dp;
			}
			(void) nfs_doio(bp);
		}
		if (error) {
			nfs_asyncdaemon[myiod] = 0;
			nfs_numasync--;
			return (error);
		}
	}
}
Commit	Line	Data
15637ed4 RG	1	/*
	2	* Copyright (c) 1989 The Regents of the University of California.
	3	* All rights reserved.
	4	*
	5	* This code is derived from software contributed to Berkeley by
	6	* Rick Macklem at The University of Guelph.
	7	*
	8	* Redistribution and use in source and binary forms, with or without
	9	* modification, are permitted provided that the following conditions
	10	* are met:
	11	* 1. Redistributions of source code must retain the above copyright
	12	* notice, this list of conditions and the following disclaimer.
	13	* 2. Redistributions in binary form must reproduce the above copyright
	14	* notice, this list of conditions and the following disclaimer in the
	15	* documentation and/or other materials provided with the distribution.
	16	* 3. All advertising materials mentioning features or use of this software
	17	* must display the following acknowledgement:
	18	* This product includes software developed by the University of
	19	* California, Berkeley and its contributors.
	20	* 4. Neither the name of the University nor the names of its contributors
	21	* may be used to endorse or promote products derived from this software
	22	* without specific prior written permission.
	23	*
	24	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	25	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	26	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	27	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	28	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	29	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	30	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	31	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	32	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	33	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	34	* SUCH DAMAGE.
	35	*
a8599e88 RG	36	* From: @(#)nfs_syscalls.c 7.26 (Berkeley) 4/16/91
a8599e88 RG	37	* $Id$
15637ed4 RG	38	*/
	39
	40	#include "param.h"
	41	#include "systm.h"
	42	#include "kernel.h"
	43	#include "file.h"
	44	#include "stat.h"
	45	#include "namei.h"
	46	#include "vnode.h"
	47	#include "mount.h"
	48	#include "proc.h"
	49	#include "malloc.h"
	50	#include "buf.h"
	51	#include "mbuf.h"
	52	#include "socket.h"
	53	#include "socketvar.h"
	54	#include "domain.h"
	55	#include "protosw.h"
	56
	57	#include "../netinet/in.h"
	58	#include "../netinet/tcp.h"
	59
	60	#include "nfsv2.h"
	61	#include "nfs.h"
	62	#include "nfsrvcache.h"
	63
	64	/* Global defs. */
	65	extern u_long nfs_prog, nfs_vers;
	66	extern int (*nfsrv_procs[NFS_NPROCS])();
	67	extern struct buf nfs_bqueue;
	68	extern int nfs_numasync;
	69	extern struct proc *nfs_iodwant[NFS_MAXASYNCDAEMON];
	70	extern int nfs_tcpnodelay;
	71	struct mbuf *nfs_compress();
	72
	73	#define TRUE 1
	74	#define FALSE 0
	75
	76	static int nfs_asyncdaemon[NFS_MAXASYNCDAEMON];
	77	static int compressreply[NFS_NPROCS] = {
	78	FALSE,
	79	TRUE,
	80	TRUE,
	81	FALSE,
	82	TRUE,
	83	TRUE,
	84	FALSE,
	85	FALSE,
	86	TRUE,
	87	TRUE,
	88	TRUE,
	89	TRUE,
	90	TRUE,
	91	TRUE,
	92	TRUE,
	93	TRUE,
	94	TRUE,
	95	TRUE,
	96	};
	97	/*
	98	* NFS server system calls
	99	* getfh() lives here too, but maybe should move to kern/vfs_syscalls.c
	100	*/
	101
102	/*
103	* Get file handle system call
104	*/
3c7eb27c DG	105
	106	struct getfh_args {
	107	char *fname;
	108	fhandle_t *fhp;
	109	};
	110
15637ed4	111	/* ARGSUSED */
a8599e88	112	int
15637ed4 RG	113	getfh(p, uap, retval)
15637ed4 RG	114	struct proc *p;
3c7eb27c	115	register struct getfh_args *uap;
15637ed4 RG	116	int *retval;
	117	{
	118	register struct nameidata *ndp;
	119	register struct vnode *vp;
	120	fhandle_t fh;
	121	int error;
	122	struct nameidata nd;
	123
	124	/*
	125	* Must be super user
	126	*/
	127	if (error = suser(p->p_ucred, &p->p_acflag))
	128	return (error);
	129	ndp = &nd;
	130	ndp->ni_nameiop = LOOKUP \| LOCKLEAF \| FOLLOW;
	131	ndp->ni_segflg = UIO_USERSPACE;
	132	ndp->ni_dirp = uap->fname;
	133	if (error = namei(ndp, p))
	134	return (error);
	135	vp = ndp->ni_vp;
	136	bzero((caddr_t)&fh, sizeof(fh));
	137	fh.fh_fsid = vp->v_mount->mnt_stat.f_fsid;
	138	error = VFS_VPTOFH(vp, &fh.fh_fid);
	139	vput(vp);
	140	if (error)
	141	return (error);
	142	error = copyout((caddr_t)&fh, (caddr_t)uap->fhp, sizeof (fh));
	143	return (error);
	144	}
	145
	146	/*
	147	* Nfs server psuedo system call for the nfsd's
	148	* Never returns unless it fails or gets killed
	149	*/
3c7eb27c DG	150
	151	struct nfssvc_args {
	152	int s;
	153	caddr_t mskval;
	154	int msklen;
	155	caddr_t mtchval;
	156	int mtchlen;
	157	};
	158
15637ed4	159	/* ARGSUSED */
a8599e88	160	int
15637ed4 RG	161	nfssvc(p, uap, retval)
15637ed4 RG	162	struct proc *p;
3c7eb27c	163	register struct nfssvc_args *uap;
15637ed4 RG	164	int *retval;
	165	{
	166	register struct mbuf *m;
	167	register int siz;
	168	register struct ucred *cr;
	169	struct file *fp;
	170	struct mbuf mreq, mrep, nam, md;
	171	struct mbuf msk, mtch;
	172	struct socket *so;
	173	caddr_t dpos;
	174	int procid, repstat, error, cacherep, wascomp;
	175	u_long retxid;
	176
	177	/*
	178	* Must be super user
	179	*/
	180	if (error = suser(p->p_ucred, &p->p_acflag))
	181	return (error);
	182	if (error = getsock(p->p_fd, uap->s, &fp))
	183	return (error);
	184	so = (struct socket *)fp->f_data;
	185	if (sosendallatonce(so))
	186	siz = NFS_MAXPACKET;
	187	else
	188	siz = NFS_MAXPACKET + sizeof(u_long);
	189	if (error = soreserve(so, siz, siz))
	190	goto bad;
	191	if (error = sockargs(&nam, uap->mskval, uap->msklen, MT_SONAME))
	192	goto bad;
	193	bcopy((caddr_t)nam, (caddr_t)&msk, sizeof (struct mbuf));
	194	msk.m_data = msk.m_dat;
	195	m_freem(nam);
	196	if (error = sockargs(&nam, uap->mtchval, uap->mtchlen, MT_SONAME))
	197	goto bad;
	198	bcopy((caddr_t)nam, (caddr_t)&mtch, sizeof (struct mbuf));
	199	mtch.m_data = mtch.m_dat;
	200	m_freem(nam);
	201
	202	/* Copy the cred so others don't see changes */
	203	cr = p->p_ucred = crcopy(p->p_ucred);
	204
	205	/*
	206	* Set protocol specific options { for now TCP only } and
	207	* reserve some space. For datagram sockets, this can get called
	208	* repeatedly for the same socket, but that isn't harmful.
	209	*/
	210	if (so->so_proto->pr_flags & PR_CONNREQUIRED) {
	211	MGET(m, M_WAIT, MT_SOOPTS);
	212	mtod(m, int ) = 1;
	213	m->m_len = sizeof(int);
	214	sosetopt(so, SOL_SOCKET, SO_KEEPALIVE, m);
	215	}
	216	if (so->so_proto->pr_domain->dom_family == AF_INET &&
	217	so->so_proto->pr_protocol == IPPROTO_TCP &&
	218	nfs_tcpnodelay) {
	219	MGET(m, M_WAIT, MT_SOOPTS);
	220	mtod(m, int ) = 1;
	221	m->m_len = sizeof(int);
	222	sosetopt(so, IPPROTO_TCP, TCP_NODELAY, m);
	223	}
	224	so->so_rcv.sb_flags &= ~SB_NOINTR;
	225	so->so_rcv.sb_timeo = 0;
	226	so->so_snd.sb_flags &= ~SB_NOINTR;
	227	so->so_snd.sb_timeo = 0;
228
229	/*
230	* Just loop around doin our stuff until SIGKILL
231	*/
232	for (;;) {
233	if (error = nfs_getreq(so, nfs_prog, nfs_vers, NFS_NPROCS-1,
234	&nam, &mrep, &md, &dpos, &retxid, &procid, cr,
235	/* 08 Sep 92*/ &msk, &mtch, &wascomp, &repstat)) {
236	if (nam)
237	m_freem(nam);
238	if (error == EPIPE \|\| error == EINTR \|\|
239	error == ERESTART) {
240	error = 0;
241	goto bad;
242	}
243	so->so_error = 0;
244	continue;
245	}
246
247	if (nam)
248	cacherep = nfsrv_getcache(nam, retxid, procid, &mreq);
249	else
250	cacherep = RC_DOIT;
251	switch (cacherep) {
252	case RC_DOIT:
253	if (error = (*(nfsrv_procs[procid]))(mrep, md, dpos,
254	cr, retxid, &mreq, &repstat, p)) {
255	nfsstats.srv_errs++;
256	if (nam) {
257	nfsrv_updatecache(nam, retxid, procid,
258	FALSE, repstat, mreq);
259	m_freem(nam);
260	}
261	break;
262	}
263	nfsstats.srvrpccnt[procid]++;
264	if (nam)
265	nfsrv_updatecache(nam, retxid, procid, TRUE,
266	repstat, mreq);
267	mrep = (struct mbuf *)0;
268	case RC_REPLY:
269	m = mreq;
270	siz = 0;
271	while (m) {
272	siz += m->m_len;
273	m = m->m_next;
274	}
275	if (siz <= 0 \|\| siz > NFS_MAXPACKET) {
276	printf("mbuf siz=%d\n",siz);
277	panic("Bad nfs svc reply");
278	}
279	mreq->m_pkthdr.len = siz;
280	mreq->m_pkthdr.rcvif = (struct ifnet *)0;
281	if (wascomp && compressreply[procid]) {
282	mreq = nfs_compress(mreq);
283	siz = mreq->m_pkthdr.len;
284	}
285	/*
286	* For non-atomic protocols, prepend a Sun RPC
287	* Record Mark.
288	*/
289	if (!sosendallatonce(so)) {
290	M_PREPEND(mreq, sizeof(u_long), M_WAIT);
291	mtod(mreq, u_long ) = htonl(0x80000000 \| siz);
292	}
293	error = nfs_send(so, nam, mreq, (struct nfsreq *)0);
294	if (nam)
295	m_freem(nam);
296	if (mrep)
297	m_freem(mrep);
298	if (error) {
299	if (error == EPIPE \|\| error == EINTR \|\|
300	error == ERESTART)
301	goto bad;
302	so->so_error = 0;
303	}
304	break;
305	case RC_DROPIT:
306	m_freem(mrep);
307	m_freem(nam);
308	break;
309	};
310	}
311	bad:
312	return (error);
313	}
314
315	/*
316	* Nfs pseudo system call for asynchronous i/o daemons.
317	* These babies just pretend to be disk interrupt service routines
318	* for client nfs. They are mainly here for read ahead/write behind.
319	* Never returns unless it fails or gets killed
320	*/
321	/* ARGSUSED */
a8599e88	322	int
15637ed4 RG	323	async_daemon(p, uap, retval)
	324	struct proc *p;
	325	struct args *uap;
	326	int *retval;
	327	{
	328	register struct buf bp, dp;
	329	register int i, myiod;
	330	int error;
	331
	332	/*
	333	* Must be super user
	334	*/
	335	if (error = suser(p->p_ucred, &p->p_acflag))
	336	return (error);
	337	/*
	338	* Assign my position or return error if too many already running
	339	*/
	340	myiod = -1;
	341	for (i = 0; i < NFS_MAXASYNCDAEMON; i++)
	342	if (nfs_asyncdaemon[i] == 0) {
	343	nfs_asyncdaemon[i]++;
	344	myiod = i;
	345	break;
	346	}
	347	if (myiod == -1)
	348	return (EBUSY);
	349	nfs_numasync++;
	350	dp = &nfs_bqueue;
	351	/*
	352	* Just loop around doin our stuff until SIGKILL
	353	*/
	354	for (;;) {
	355	while (dp->b_actf == NULL && error == 0) {
	356	nfs_iodwant[myiod] = p;
	357	error = tsleep((caddr_t)&nfs_iodwant[myiod],
	358	PWAIT \| PCATCH, "nfsidl", 0);
	359	nfs_iodwant[myiod] = (struct proc *)0;
	360	}
	361	while (dp->b_actf != NULL) {
	362	/* Take one off the end of the list */
	363	bp = dp->b_actl;
	364	if (bp->b_actl == dp) {
	365	dp->b_actf = dp->b_actl = (struct buf *)0;
	366	} else {
	367	dp->b_actl = bp->b_actl;
	368	bp->b_actl->b_actf = dp;
	369	}
	370	(void) nfs_doio(bp);
	371	}
	372	if (error) {
	373	nfs_asyncdaemon[myiod] = 0;
	374	nfs_numasync--;
	375	return (error);
	376	}
	377	}
	378	}