[unix-history] / sys / kern / fifo_vnops.c

/*
 * Copyright (c) 1990 The Regents of the University of California.
 * All rights reserved.
 *
 * 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: @(#)fifo_vnops.c	7.7 (Berkeley) 4/15/91
 *	$Id$
 */

#ifdef	FIFO
#include "param.h"
#include "time.h"
#include "namei.h"
#include "vnode.h"
#include "socket.h"
#include "socketvar.h"
#include "stat.h"
#include "systm.h"
#include "ioctl.h"
#include "file.h"
#include "fifo.h"
#include "errno.h"
#include "malloc.h"

/*
 * This structure is associated with the FIFO vnode and stores
 * the state associated with the FIFO.
 */
struct fifoinfo {
	struct socket	*fi_readsock;
	struct socket	*fi_writesock;
	long		fi_readers;
	long		fi_writers;
};

struct vnodeops fifo_vnodeops = {
	fifo_lookup,		/* lookup */
	fifo_create,		/* create */
	fifo_mknod,		/* mknod */
	fifo_open,		/* open */
	fifo_close,		/* close */
	fifo_access,		/* access */
	fifo_getattr,		/* getattr */
	fifo_setattr,		/* setattr */
	fifo_read,		/* read */
	fifo_write,		/* write */
	fifo_ioctl,		/* ioctl */
	fifo_select,		/* select */
	fifo_mmap,		/* mmap */
	fifo_fsync,		/* fsync */
	fifo_seek,		/* seek */
	fifo_remove,		/* remove */
	fifo_link,		/* link */
	fifo_rename,		/* rename */
	fifo_mkdir,		/* mkdir */
	fifo_rmdir,		/* rmdir */
	fifo_symlink,		/* symlink */
	fifo_readdir,		/* readdir */
	fifo_readlink,		/* readlink */
	fifo_abortop,		/* abortop */
	fifo_inactive,		/* inactive */
	fifo_reclaim,		/* reclaim */
	fifo_lock,		/* lock */
	fifo_unlock,		/* unlock */
	fifo_bmap,		/* bmap */
	fifo_strategy,		/* strategy */
	fifo_print,		/* print */
	fifo_islocked,		/* islocked */
	fifo_advlock,		/* advlock */
};

/*
 * Trivial lookup routine that always fails.
 */
/* ARGSUSED */
fifo_lookup(vp, ndp, p)
	struct vnode *vp;
	struct nameidata *ndp;
	struct proc *p;
{

	ndp->ni_dvp = vp;
	ndp->ni_vp = NULL;
	return (ENOTDIR);
}

/*
 * Open called to set up a new instance of a fifo or
 * to find an active instance of a fifo.
 */
/* ARGSUSED */
fifo_open(vp, mode, cred, p)
	register struct vnode *vp;
	int mode;
	struct ucred *cred;
	struct proc *p;
{
	register struct fifoinfo *fip;
	struct socket *rso, *wso;
	int error;
	static char openstr[] = "fifo";

	if ((mode & (FREAD|FWRITE)) == (FREAD|FWRITE))
		return (EINVAL);
	if ((fip = vp->v_fifoinfo) == NULL) {
		MALLOC(fip, struct fifoinfo *, sizeof(*fip), M_VNODE, M_WAITOK);
		vp->v_fifoinfo = fip;
		fip->fi_readers = fip->fi_writers = 0;
		if (error = socreate(AF_UNIX, &rso, SOCK_STREAM, 0)) {
			free(fip, M_VNODE);
			vp->v_fifoinfo = NULL;
			return (error);
		}
		fip->fi_readsock = rso;
		if (error = socreate(AF_UNIX, &wso, SOCK_STREAM, 0)) {
			(void)soclose(rso);
			free(fip, M_VNODE);
			vp->v_fifoinfo = NULL;
			return (error);
		}
		fip->fi_writesock = wso;
		if (error = unp_connect2(wso, rso)) {
			(void)soclose(wso);
			(void)soclose(rso);
			free(fip, M_VNODE);
			vp->v_fifoinfo = NULL;
			return (error);
		}
		wso->so_state |= SS_CANTRCVMORE;
		rso->so_state |= SS_CANTSENDMORE;
	}
	error = 0;
	if (mode & FREAD) {
		fip->fi_readers++;
		if (fip->fi_readers == 1) {
			fip->fi_writesock->so_state &= ~SS_CANTSENDMORE;
			if (fip->fi_writers > 0)
				wakeup((caddr_t)&fip->fi_writers);
		}
		if (mode & O_NONBLOCK)
			return (0);
		while (fip->fi_writers == 0) {
			VOP_UNLOCK(vp);
			error = tsleep((caddr_t)&fip->fi_readers, PSOCK | PCATCH,
			    		openstr, 0);
			VOP_LOCK(vp);
			if (error)
				break;
		}
	} else {
		fip->fi_writers++;
		if (fip->fi_readers == 0 && (mode & O_NONBLOCK)) {
			error = ENXIO;
		} else {
			if (fip->fi_writers == 1) {
				fip->fi_readsock->so_state &= ~SS_CANTRCVMORE;
				if (fip->fi_readers > 0)
					wakeup((caddr_t)&fip->fi_readers);
			}
			while (fip->fi_readers == 0) {
				VOP_UNLOCK(vp);
				error = tsleep((caddr_t)&fip->fi_writers,
				    		PSOCK | PCATCH, openstr, 0);
				VOP_LOCK(vp);
				if (error)
					break;
			}
		}
	}
	if (error)
		fifo_close(vp, mode, cred, p);
	return (error);
}

/*
 * Vnode op for read
 */
/* ARGSUSED */
fifo_read(vp, uio, ioflag, cred)
	struct vnode *vp;
	register struct uio *uio;
	int ioflag;
	struct ucred *cred;
{
	register struct socket *rso = vp->v_fifoinfo->fi_readsock;
	int error, startresid;

#ifdef DIAGNOSTIC
	if (uio->uio_rw != UIO_READ)
		panic("fifo_read mode");
#endif
	if (uio->uio_resid == 0)
		return (0);
	if (ioflag & IO_NDELAY)
		rso->so_state |= SS_NBIO;
	startresid = uio->uio_resid;
	VOP_UNLOCK(vp);
	error = soreceive(rso, (struct mbuf **)0, uio, (int *)0,
		(struct mbuf **)0, (struct mbuf **)0);
	VOP_LOCK(vp);
	/*
	 * Clear EOF indication after first such return.
	 */
	if (uio->uio_resid == startresid)
		rso->so_state &= ~SS_CANTRCVMORE;
	if (ioflag & IO_NDELAY)
		rso->so_state &= ~SS_NBIO;
	return (error);
}

/*
 * Vnode op for write
 */
/* ARGSUSED */
fifo_write(vp, uio, ioflag, cred)
	struct vnode *vp;
	register struct uio *uio;
	int ioflag;
	struct ucred *cred;
{
	struct socket *wso = vp->v_fifoinfo->fi_writesock;
	int error;

#ifdef DIAGNOSTIC
	if (uio->uio_rw != UIO_WRITE)
		panic("fifo_write mode");
#endif
	if (ioflag & IO_NDELAY)
		wso->so_state |= SS_NBIO;
	VOP_UNLOCK(vp);
	error = sosend(wso, (struct mbuf *)0, uio, 0, (struct mbuf *)0, 0);
	VOP_LOCK(vp);
	if (ioflag & IO_NDELAY)
		wso->so_state &= ~SS_NBIO;
	return (error);
}

/*
 * Device ioctl operation.
 */
/* ARGSUSED */
fifo_ioctl(vp, com, data, fflag, cred, p)
	struct vnode *vp;
	int com;
	caddr_t data;
	int fflag;
	struct ucred *cred;
	struct proc *p;
{
	struct file filetmp;
	int error;

	if (com == FIONBIO)
		return (0);
	if (fflag & FREAD)
		filetmp.f_data = (caddr_t)vp->v_fifoinfo->fi_readsock;
	else
		filetmp.f_data = (caddr_t)vp->v_fifoinfo->fi_writesock;
	return (soo_ioctl(&filetmp, com, data, p));
}

/* ARGSUSED */
fifo_select(vp, which, fflag, cred, p)
	struct vnode *vp;
	int which, fflag;
	struct ucred *cred;
	struct proc *p;
{
	struct file filetmp;
	int error;

	if (fflag & FREAD)
		filetmp.f_data = (caddr_t)vp->v_fifoinfo->fi_readsock;
	else
		filetmp.f_data = (caddr_t)vp->v_fifoinfo->fi_writesock;
	return (soo_select(&filetmp, which, p));
}

/*
 * This is a noop, simply returning what one has been given.
 */
fifo_bmap(vp, bn, vpp, bnp)
	struct vnode *vp;
	daddr_t bn;
	struct vnode **vpp;
	daddr_t *bnp;
{

	if (vpp != NULL)
		*vpp = vp;
	if (bnp != NULL)
		*bnp = bn;
	return (0);
}

/*
 * At the moment we do not do any locking.
 */
/* ARGSUSED */
fifo_lock(vp)
	struct vnode *vp;
{

	return (0);
}

/* ARGSUSED */
fifo_unlock(vp)
	struct vnode *vp;
{

	return (0);
}

/*
 * Device close routine
 */
/* ARGSUSED */
fifo_close(vp, fflag, cred, p)
	register struct vnode *vp;
	int fflag;
	struct ucred *cred;
	struct proc *p;
{
	register struct fifoinfo *fip = vp->v_fifoinfo;
	int error1, error2;

	if (fflag & FWRITE) {
		fip->fi_writers--;
		if (fip->fi_writers == 0)
			socantrcvmore(fip->fi_readsock);
	} else {
		fip->fi_readers--;
		if (fip->fi_readers == 0)
			socantsendmore(fip->fi_writesock);
	}
	if (vp->v_usecount > 1)
		return (0);
	error1 = soclose(fip->fi_readsock);
	error2 = soclose(fip->fi_writesock);
	FREE(fip, M_VNODE);
	vp->v_fifoinfo = NULL;
	if (error1)
		return (error1);
	return (error2);
}

/*
 * Print out the contents of a fifo vnode.
 */
fifo_print(vp)
	struct vnode *vp;
{

	printf("tag VT_NON");
	fifo_printinfo(vp);
	printf("\n");
}

/*
 * Print out internal contents of a fifo vnode.
 */
fifo_printinfo(vp)
	struct vnode *vp;
{
	register struct fifoinfo *fip = vp->v_fifoinfo;

	printf(", fifo with %d readers and %d writers",
		fip->fi_readers, fip->fi_writers);
}

/*
 * Fifo failed operation
 */
fifo_ebadf()
{

	return (EBADF);
}

/*
 * Fifo advisory byte-level locks.
 */
/* ARGSUSED */
fifo_advlock(vp, id, op, fl, flags)
	struct vnode *vp;
	caddr_t id;
	int op;
	struct flock *fl;
	int flags;
{

	return (EOPNOTSUPP);
}

/*
 * Fifo bad operation
 */
fifo_badop()
{

	panic("fifo_badop called");
	/* NOTREACHED */
}
#endif	/*FIFO*/
Commit	Line	Data
15637ed4 RG	1	/*
	2	* Copyright (c) 1990 The Regents of the University of California.
	3	* All rights reserved.
	4	*
	5	* Redistribution and use in source and binary forms, with or without
	6	* modification, are permitted provided that the following conditions
	7	* are met:
	8	* 1. Redistributions of source code must retain the above copyright
	9	* notice, this list of conditions and the following disclaimer.
	10	* 2. Redistributions in binary form must reproduce the above copyright
	11	* notice, this list of conditions and the following disclaimer in the
	12	* documentation and/or other materials provided with the distribution.
	13	* 3. All advertising materials mentioning features or use of this software
	14	* must display the following acknowledgement:
	15	* This product includes software developed by the University of
	16	* California, Berkeley and its contributors.
	17	* 4. Neither the name of the University nor the names of its contributors
	18	* may be used to endorse or promote products derived from this software
	19	* without specific prior written permission.
	20	*
	21	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	22	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	23	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	24	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	25	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	26	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	27	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	28	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	29	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	30	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	31	* SUCH DAMAGE.
	32	*
78ed81a3	33	* from: @(#)fifo_vnops.c 7.7 (Berkeley) 4/15/91
78ed81a3	34	* $Id$
15637ed4 RG	35	*/
15637ed4 RG	36
78ed81a3	37	#ifdef FIFO
15637ed4 RG	38	#include "param.h"
	39	#include "time.h"
	40	#include "namei.h"
	41	#include "vnode.h"
	42	#include "socket.h"
	43	#include "socketvar.h"
	44	#include "stat.h"
	45	#include "systm.h"
	46	#include "ioctl.h"
	47	#include "file.h"
	48	#include "fifo.h"
	49	#include "errno.h"
	50	#include "malloc.h"
	51
	52	/*
	53	* This structure is associated with the FIFO vnode and stores
	54	* the state associated with the FIFO.
	55	*/
	56	struct fifoinfo {
	57	struct socket *fi_readsock;
	58	struct socket *fi_writesock;
	59	long fi_readers;
	60	long fi_writers;
	61	};
	62
	63	struct vnodeops fifo_vnodeops = {
	64	fifo_lookup, /* lookup */
	65	fifo_create, /* create */
	66	fifo_mknod, /* mknod */
	67	fifo_open, /* open */
	68	fifo_close, /* close */
	69	fifo_access, /* access */
	70	fifo_getattr, /* getattr */
	71	fifo_setattr, /* setattr */
	72	fifo_read, /* read */
	73	fifo_write, /* write */
	74	fifo_ioctl, /* ioctl */
	75	fifo_select, /* select */
	76	fifo_mmap, /* mmap */
	77	fifo_fsync, /* fsync */
	78	fifo_seek, /* seek */
	79	fifo_remove, /* remove */
	80	fifo_link, /* link */
	81	fifo_rename, /* rename */
	82	fifo_mkdir, /* mkdir */
	83	fifo_rmdir, /* rmdir */
	84	fifo_symlink, /* symlink */
	85	fifo_readdir, /* readdir */
	86	fifo_readlink, /* readlink */
	87	fifo_abortop, /* abortop */
	88	fifo_inactive, /* inactive */
	89	fifo_reclaim, /* reclaim */
	90	fifo_lock, /* lock */
	91	fifo_unlock, /* unlock */
	92	fifo_bmap, /* bmap */
	93	fifo_strategy, /* strategy */
	94	fifo_print, /* print */
	95	fifo_islocked, /* islocked */
	96	fifo_advlock, /* advlock */
	97	};
	98
	99	/*
	100	* Trivial lookup routine that always fails.
	101	*/
102	/* ARGSUSED */
103	fifo_lookup(vp, ndp, p)
104	struct vnode *vp;
105	struct nameidata *ndp;
106	struct proc *p;
107	{
108
109	ndp->ni_dvp = vp;
110	ndp->ni_vp = NULL;
111	return (ENOTDIR);
112	}
113
114	/*
115	* Open called to set up a new instance of a fifo or
116	* to find an active instance of a fifo.
117	*/
118	/* ARGSUSED */
119	fifo_open(vp, mode, cred, p)
120	register struct vnode *vp;
121	int mode;
122	struct ucred *cred;
123	struct proc *p;
124	{
125	register struct fifoinfo *fip;
126	struct socket rso, wso;
127	int error;
128	static char openstr[] = "fifo";
129
130	if ((mode & (FREAD\|FWRITE)) == (FREAD\|FWRITE))
131	return (EINVAL);
132	if ((fip = vp->v_fifoinfo) == NULL) {
133	MALLOC(fip, struct fifoinfo , sizeof(fip), M_VNODE, M_WAITOK);
134	vp->v_fifoinfo = fip;
135	fip->fi_readers = fip->fi_writers = 0;
136	if (error = socreate(AF_UNIX, &rso, SOCK_STREAM, 0)) {
137	free(fip, M_VNODE);
138	vp->v_fifoinfo = NULL;
139	return (error);
140	}
141	fip->fi_readsock = rso;
142	if (error = socreate(AF_UNIX, &wso, SOCK_STREAM, 0)) {
143	(void)soclose(rso);
144	free(fip, M_VNODE);
145	vp->v_fifoinfo = NULL;
146	return (error);
147	}
148	fip->fi_writesock = wso;
149	if (error = unp_connect2(wso, rso)) {
150	(void)soclose(wso);
151	(void)soclose(rso);
152	free(fip, M_VNODE);
153	vp->v_fifoinfo = NULL;
154	return (error);
155	}
156	wso->so_state \|= SS_CANTRCVMORE;
157	rso->so_state \|= SS_CANTSENDMORE;
158	}
159	error = 0;
160	if (mode & FREAD) {
161	fip->fi_readers++;
162	if (fip->fi_readers == 1) {
163	fip->fi_writesock->so_state &= ~SS_CANTSENDMORE;
164	if (fip->fi_writers > 0)
165	wakeup((caddr_t)&fip->fi_writers);
166	}
167	if (mode & O_NONBLOCK)
168	return (0);
169	while (fip->fi_writers == 0) {
170	VOP_UNLOCK(vp);
171	error = tsleep((caddr_t)&fip->fi_readers, PSOCK \| PCATCH,
172	openstr, 0);
173	VOP_LOCK(vp);
174	if (error)
175	break;
176	}
177	} else {
178	fip->fi_writers++;
179	if (fip->fi_readers == 0 && (mode & O_NONBLOCK)) {
180	error = ENXIO;
181	} else {
182	if (fip->fi_writers == 1) {
183	fip->fi_readsock->so_state &= ~SS_CANTRCVMORE;
184	if (fip->fi_readers > 0)
185	wakeup((caddr_t)&fip->fi_readers);
186	}
187	while (fip->fi_readers == 0) {
188	VOP_UNLOCK(vp);
189	error = tsleep((caddr_t)&fip->fi_writers,
190	PSOCK \| PCATCH, openstr, 0);
191	VOP_LOCK(vp);
192	if (error)
193	break;
194	}
195	}
196	}
197	if (error)
198	fifo_close(vp, mode, cred, p);
199	return (error);
200	}
201
202	/*
203	* Vnode op for read
204	*/
205	/* ARGSUSED */
206	fifo_read(vp, uio, ioflag, cred)
207	struct vnode *vp;
208	register struct uio *uio;
209	int ioflag;
210	struct ucred *cred;
211	{
212	register struct socket *rso = vp->v_fifoinfo->fi_readsock;
213	int error, startresid;
214
215	#ifdef DIAGNOSTIC
216	if (uio->uio_rw != UIO_READ)
217	panic("fifo_read mode");
218	#endif
219	if (uio->uio_resid == 0)
220	return (0);
221	if (ioflag & IO_NDELAY)
222	rso->so_state \|= SS_NBIO;
223	startresid = uio->uio_resid;
224	VOP_UNLOCK(vp);
225	error = soreceive(rso, (struct mbuf *)0, uio, (int )0,
226	(struct mbuf )0, (struct mbuf )0);
227	VOP_LOCK(vp);
228	/*
229	* Clear EOF indication after first such return.
230	*/
231	if (uio->uio_resid == startresid)
232	rso->so_state &= ~SS_CANTRCVMORE;
233	if (ioflag & IO_NDELAY)
234	rso->so_state &= ~SS_NBIO;
235	return (error);
236	}
237
238	/*
239	* Vnode op for write
240	*/
241	/* ARGSUSED */
242	fifo_write(vp, uio, ioflag, cred)
243	struct vnode *vp;
244	register struct uio *uio;
245	int ioflag;
246	struct ucred *cred;
247	{
248	struct socket *wso = vp->v_fifoinfo->fi_writesock;
249	int error;
250
251	#ifdef DIAGNOSTIC
252	if (uio->uio_rw != UIO_WRITE)
253	panic("fifo_write mode");
254	#endif
255	if (ioflag & IO_NDELAY)
256	wso->so_state \|= SS_NBIO;
257	VOP_UNLOCK(vp);
78ed81a3	258	error = sosend(wso, (struct mbuf )0, uio, 0, (struct mbuf )0, 0);
15637ed4 RG	259	VOP_LOCK(vp);
	260	if (ioflag & IO_NDELAY)
	261	wso->so_state &= ~SS_NBIO;
	262	return (error);
	263	}
	264
	265	/*
	266	* Device ioctl operation.
	267	*/
	268	/* ARGSUSED */
	269	fifo_ioctl(vp, com, data, fflag, cred, p)
	270	struct vnode *vp;
	271	int com;
	272	caddr_t data;
	273	int fflag;
	274	struct ucred *cred;
	275	struct proc *p;
	276	{
	277	struct file filetmp;
	278	int error;
	279
	280	if (com == FIONBIO)
	281	return (0);
	282	if (fflag & FREAD)
	283	filetmp.f_data = (caddr_t)vp->v_fifoinfo->fi_readsock;
	284	else
	285	filetmp.f_data = (caddr_t)vp->v_fifoinfo->fi_writesock;
	286	return (soo_ioctl(&filetmp, com, data, p));
	287	}
	288
	289	/* ARGSUSED */
	290	fifo_select(vp, which, fflag, cred, p)
	291	struct vnode *vp;
	292	int which, fflag;
	293	struct ucred *cred;
	294	struct proc *p;
	295	{
	296	struct file filetmp;
	297	int error;
	298
	299	if (fflag & FREAD)
	300	filetmp.f_data = (caddr_t)vp->v_fifoinfo->fi_readsock;
	301	else
	302	filetmp.f_data = (caddr_t)vp->v_fifoinfo->fi_writesock;
	303	return (soo_select(&filetmp, which, p));
	304	}
	305
	306	/*
	307	* This is a noop, simply returning what one has been given.
	308	*/
	309	fifo_bmap(vp, bn, vpp, bnp)
	310	struct vnode *vp;
	311	daddr_t bn;
	312	struct vnode **vpp;
	313	daddr_t *bnp;
	314	{
	315
	316	if (vpp != NULL)
	317	*vpp = vp;
	318	if (bnp != NULL)
	319	*bnp = bn;
	320	return (0);
	321	}
	322
323	/*
324	* At the moment we do not do any locking.
325	*/
326	/* ARGSUSED */
327	fifo_lock(vp)
328	struct vnode *vp;
329	{
330
331	return (0);
332	}
333
334	/* ARGSUSED */
335	fifo_unlock(vp)
336	struct vnode *vp;
337	{
338
339	return (0);
340	}
341
342	/*
343	* Device close routine
344	*/
345	/* ARGSUSED */
346	fifo_close(vp, fflag, cred, p)
347	register struct vnode *vp;
348	int fflag;
349	struct ucred *cred;
350	struct proc *p;
351	{
352	register struct fifoinfo *fip = vp->v_fifoinfo;
353	int error1, error2;
354
355	if (fflag & FWRITE) {
356	fip->fi_writers--;
357	if (fip->fi_writers == 0)
358	socantrcvmore(fip->fi_readsock);
359	} else {
360	fip->fi_readers--;
361	if (fip->fi_readers == 0)
362	socantsendmore(fip->fi_writesock);
363	}
364	if (vp->v_usecount > 1)
365	return (0);
366	error1 = soclose(fip->fi_readsock);
367	error2 = soclose(fip->fi_writesock);
368	FREE(fip, M_VNODE);
369	vp->v_fifoinfo = NULL;
370	if (error1)
371	return (error1);
372	return (error2);
373	}
374
375	/*
376	* Print out the contents of a fifo vnode.
377	*/
378	fifo_print(vp)
379	struct vnode *vp;
380	{
381
382	printf("tag VT_NON");
383	fifo_printinfo(vp);
384	printf("\n");
385	}
386
387	/*
388	* Print out internal contents of a fifo vnode.
389	*/
390	fifo_printinfo(vp)
391	struct vnode *vp;
392	{
393	register struct fifoinfo *fip = vp->v_fifoinfo;
394
395	printf(", fifo with %d readers and %d writers",
396	fip->fi_readers, fip->fi_writers);
397	}
398
399	/*
400	* Fifo failed operation
401	*/
402	fifo_ebadf()
403	{
404
405	return (EBADF);
406	}
407
408	/*
409	* Fifo advisory byte-level locks.
410	*/
411	/* ARGSUSED */
412	fifo_advlock(vp, id, op, fl, flags)
413	struct vnode *vp;
414	caddr_t id;
415	int op;
416	struct flock *fl;
417	int flags;
418	{
419
420	return (EOPNOTSUPP);
421	}
422
423	/*
424	* Fifo bad operation
425	*/
426	fifo_badop()
427	{
428
429	panic("fifo_badop called");
430	/* NOTREACHED */
431	}
78ed81a3	432	#endif /FIFO/