port kqueue changes from freebsd, plus all required openbsd glue.

okay deraadt@, millert@
from jlemon@freebsd.org:
extend kqueue down to the device layer, backwards compatible approach
suggested by peter@freebsd.org

8 files changed, 254 insertions, 205 deletions

diff --git a/sys/kern/kern_event.c b/sys/kern/kern_event.c
index d407ba8ad27..5e7ea093237 100644
--- a/sys/kern/kern_event.c
+++ b/sys/kern/kern_event.c
@@ -1,7 +1,7 @@
-/*	$OpenBSD: kern_event.c,v 1.6 2000/11/21 21:49:57 provos Exp $	*/
+/*	$OpenBSD: kern_event.c,v 1.7 2001/03/01 20:54:33 provos Exp $	*/
 
 /*-
- * Copyright (c) 1999,2000 Jonathan Lemon <jlemon@FreeBSD.org>
+ * Copyright (c) 1999,2000,2001 Jonathan Lemon <jlemon@FreeBSD.org>
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -25,7 +25,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- * $FreeBSD: src/sys/kern/kern_event.c,v 1.15 2000/08/07 16:45:42 jlemon Exp $
+ * $FreeBSD: src/sys/kern/kern_event.c,v 1.22 2001/02/23 20:32:42 jlemon Exp $
  */
 
 #include <sys/param.h>
@@ -49,15 +49,6 @@
 #include <sys/mount.h>
 #include <sys/syscallargs.h>
 
-int	filt_nullattach(struct knote *kn);
-int	filt_rwtypattach(struct knote *kn);
-int	filt_kqattach(struct knote *kn);
-void	filt_kqdetach(struct knote *kn);
-int	filt_kqueue(struct knote *kn, long hint);
-int	filt_procattach(struct knote *kn);
-void	filt_procdetach(struct knote *kn);
-int	filt_proc(struct knote *kn, long hint);
-
 int	kqueue_scan(struct file *fp, int maxevents,
 		    struct kevent *ulistp, const struct timespec *timeout,
 		    struct proc *p, int *retval);
@@ -69,9 +60,19 @@ int	kqueue_write(struct file *fp, off_t *poff, struct uio *uio,
 int	kqueue_ioctl(struct file *fp, u_long com, caddr_t data,
 		    struct proc *p);
 int	kqueue_select(struct file *fp, int which, struct proc *p);
+int 	kqueue_kqfilter(struct file *fp, struct knote *kn);
 int	kqueue_close(struct file *fp, struct proc *p);
 void	kqueue_wakeup(struct kqueue *kq);
 
+struct fileops kqueueops = {
+	kqueue_read,
+	kqueue_write,
+	kqueue_ioctl,
+	kqueue_select,
+	kqueue_kqfilter,
+	kqueue_close
+};
+
 void	knote_attach(struct knote *kn, struct filedesc *fdp);
 void	knote_drop(struct knote *kn, struct proc *p);
 void	knote_enqueue(struct knote *kn);
@@ -79,6 +80,20 @@ void	knote_dequeue(struct knote *kn);
 struct	knote *knote_alloc(void);
 void	knote_free(struct knote *kn);
 
+void	filt_kqdetach(struct knote *kn);
+int	filt_kqueue(struct knote *kn, long hint);
+int	filt_procattach(struct knote *kn);
+void	filt_procdetach(struct knote *kn);
+int	filt_proc(struct knote *kn, long hint);
+int	filt_fileattach(struct knote *kn);
+
+struct filterops kqread_filtops =
+	{ 1, NULL, filt_kqdetach, filt_kqueue };
+struct filterops proc_filtops =
+	{ 0, filt_procattach, filt_procdetach, filt_proc };
+struct filterops file_filtops =
+	{ 1, filt_fileattach, NULL, NULL };
+
 #define KNOTE_ACTIVATE(kn) do {						\
 	kn->kn_status |= KN_ACTIVE;					\
 	if ((kn->kn_status & (KN_QUEUED | KN_DISABLED)) == 0)		\
@@ -88,88 +103,40 @@ void	knote_free(struct knote *kn);
 #define	KN_HASHSIZE		64		/* XXX should be tunable */
 #define KN_HASH(val, mask)	(((val) ^ (val >> 8)) & (mask))
 
-struct fileops kqueueops = {
-	kqueue_read,
-	kqueue_write,
-	kqueue_ioctl,
-	kqueue_select,
-	kqueue_close
-};
-
-extern struct filterops so_rwfiltops[];
-extern struct filterops pipe_rwfiltops[];
-#ifdef notyet
-extern struct filterops fifo_rwfiltops[];
-#endif
-extern struct filterops vn_rwfiltops[];
-
-struct filterops kq_rwfiltops[] = {
-    { 1, filt_kqattach, filt_kqdetach, filt_kqueue },
-    { 1, filt_nullattach, NULL, NULL },
-};
-
 extern struct filterops sig_filtops;
 #ifdef notyet
 extern struct filterops aio_filtops;
 #endif
-extern struct filterops vn_filtops;
-
-struct filterops rwtype_filtops =
-	{ 1, filt_rwtypattach, NULL, NULL };
-struct filterops proc_filtops =
-	{ 0, filt_procattach, filt_procdetach, filt_proc };
 
 /*
- * XXX
- * These must match the order of defines in <sys/file.h>
- */
-struct filterops *rwtypfilt_sw[] = {
-	NULL,				/* 0 */
-	vn_rwfiltops,			/* DTYPE_VNODE */
-	so_rwfiltops,			/* DTYPE_SOCKET */
-	pipe_rwfiltops,			/* DTYPE_PIPE */
-	/* fifo_rwfiltops, */		/* DTYPE_FIFO */
-	kq_rwfiltops,			/* DTYPE_KQUEUE */
-};
-
-/*
- * table for all system-defined filters.
+ * Table for for all system-defined filters.
  */
 struct filterops *sysfilt_ops[] = {
-	&rwtype_filtops,		/* EVFILT_READ */
-	&rwtype_filtops,		/* EVFILT_WRITE */
+	&file_filtops,			/* EVFILT_READ */
+	&file_filtops,			/* EVFILT_WRITE */
 	NULL, /*&aio_filtops,*/		/* EVFILT_AIO */
-	&vn_filtops,			/* EVFILT_VNODE */
+	&file_filtops,			/* EVFILT_VNODE */
 	&proc_filtops,			/* EVFILT_PROC */
 	&sig_filtops,			/* EVFILT_SIGNAL */
 };
 
 int
-filt_nullattach(struct knote *kn)
-{
-	return (ENXIO);
-}
-
-/*
- * file-type specific attach routine for read/write filters
- */
-int
-filt_rwtypattach(struct knote *kn)
+filt_fileattach(struct knote *kn)
 {
-	struct filterops *fops;
+	struct file *fp = kn->kn_fp;
 
-	fops = rwtypfilt_sw[kn->kn_fp->f_type];
-	if (fops == NULL)
-		return (EINVAL);
-	kn->kn_fop = &fops[~kn->kn_filter];	/* convert to 0-base index */
-	return (kn->kn_fop->f_attach(kn));
+	return ((*fp->f_ops->fo_kqfilter)(fp, kn));
 }
 
 int
-filt_kqattach(struct knote *kn)
+kqueue_kqfilter(struct file *fp, struct knote *kn)
 {
 	struct kqueue *kq = (struct kqueue *)kn->kn_fp->f_data;
 
+	if (kn->kn_filter != EVFILT_READ)
+		return (1);
+
+	kn->kn_fop = &kqread_filtops;
 	SLIST_INSERT_HEAD(&kq->kq_sel.si_note, kn, kn_selnext);
 	return (0);
 }
@@ -338,7 +305,7 @@ sys_kevent(struct proc *p, void *v, register_t *retval)
 	} */ *uap = v;
 	struct kevent *kevp;
 	struct kqueue *kq;
-	struct file *fp;
+	struct file *fp = NULL;
 	struct timespec ts;
 	int i, n, nerrors, error;
 
@@ -347,10 +314,12 @@ sys_kevent(struct proc *p, void *v, register_t *retval)
 	    (fp->f_type != DTYPE_KQUEUE))
 		return (EBADF);
 
+	fp->f_count++;
+
 	if (SCARG(uap, timeout) != NULL) {
 		error = copyin(SCARG(uap, timeout), &ts, sizeof(ts));
 		if (error)
-			return error;
+			goto done;
 		SCARG(uap, timeout) = &ts;
 	}
 
@@ -363,7 +332,7 @@ sys_kevent(struct proc *p, void *v, register_t *retval)
 		error = copyin(SCARG(uap, changelist), kq->kq_kev,
 		    n * sizeof(struct kevent));
 		if (error)
-			return (error);
+			goto done;
 		for (i = 0; i < n; i++) {
 			kevp = &kq->kq_kev[i];
 			kevp->flags &= ~EV_SYSFLAGS;
@@ -379,7 +348,7 @@ sys_kevent(struct proc *p, void *v, register_t *retval)
 					SCARG(uap, nevents)--;
 					nerrors++;
 				} else {
-					return (error);
+					goto done;
 				}
 			}
 		}
@@ -388,12 +357,16 @@ sys_kevent(struct proc *p, void *v, register_t *retval)
 	}
 	if (nerrors) {
 		*retval = nerrors;
-		return (0);
+		error = 0;
+		goto done;
 	}
 
 	error = kqueue_scan(fp, SCARG(uap, nevents), SCARG(uap, eventlist),
 			    SCARG(uap, timeout), p, &n);
 	*retval = n;
+ done:
+	if (fp != NULL)
+		closef(fp, p);
 	return (error);
 }
 
@@ -427,6 +400,7 @@ kqueue_register(struct kqueue *kq, struct kevent *kev, struct proc *p)
 		if ((u_int)kev->ident >= fdp->fd_nfiles ||
 		    (fp = fdp->fd_ofiles[kev->ident]) == NULL)
 			return (EBADF);
+		fp->f_count++;
 
 		if (kev->ident < fdp->fd_knlistsize) {
 			SLIST_FOREACH(kn, &fdp->fd_knlist[kev->ident], kn_link)
@@ -448,8 +422,10 @@ kqueue_register(struct kqueue *kq, struct kevent *kev, struct proc *p)
 		}
 	}
 
-	if (kn == NULL && ((kev->flags & EV_ADD) == 0))
-		return (ENOENT);
+	if (kn == NULL && ((kev->flags & EV_ADD) == 0)) {
+		error = ENOENT;
+		goto done;
+	}
 
 	/*
 	 * kn now contains the matching knote, or NULL if no match
@@ -458,14 +434,20 @@ kqueue_register(struct kqueue *kq, struct kevent *kev, struct proc *p)
 
 		if (kn == NULL) {
 			kn = knote_alloc();
-			if (kn == NULL)
-				return (ENOMEM);
-			if (fp != NULL)
-				fp->f_count++;
+			if (kn == NULL) {
+				error = ENOMEM;
+				goto done;
+			}
 			kn->kn_fp = fp;
 			kn->kn_kq = kq;
 			kn->kn_fop = fops;
 
+			/*
+			 * apply reference count to knote structure, and
+			 * do not release it at the end of this routine.
+			 */
+			fp = NULL;
+
 			kn->kn_sfflags = kev->fflags;
 			kn->kn_sdata = kev->data;
 			kev->fflags = 0;
@@ -516,6 +498,8 @@ kqueue_register(struct kqueue *kq, struct kevent *kev, struct proc *p)
 	}
 
 done:
+	if (fp != NULL)
+		closef(fp, p);
 	return (error);
 }
 
diff --git a/sys/kern/spec_vnops.c b/sys/kern/spec_vnops.c
index 5d6281fc865..b241aed4e27 100644
--- a/sys/kern/spec_vnops.c
+++ b/sys/kern/spec_vnops.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: spec_vnops.c,v 1.17 2001/02/24 19:07:10 csapuntz Exp $	*/
+/*	$OpenBSD: spec_vnops.c,v 1.18 2001/03/01 20:54:35 provos Exp $	*/
 /*	$NetBSD: spec_vnops.c,v 1.29 1996/04/22 01:42:38 christos Exp $	*/
 
 /*
@@ -81,6 +81,7 @@ struct vnodeopv_entry_desc spec_vnodeop_entries[] = {
 	{ &vop_lease_desc, spec_lease_check },		/* lease */
 	{ &vop_ioctl_desc, spec_ioctl },		/* ioctl */
 	{ &vop_select_desc, spec_select },		/* select */
+	{ &vop_kqfilter_desc, spec_kqfilter },		/* kqfilter */
 	{ &vop_revoke_desc, spec_revoke },              /* revoke */
 	{ &vop_mmap_desc, spec_mmap },			/* mmap */
 	{ &vop_fsync_desc, spec_fsync },		/* fsync */
@@ -472,6 +473,24 @@ spec_select(v)
 		return (*cdevsw[major(dev)].d_select)(dev, ap->a_which, ap->a_p);
 	}
 }
+/* ARGSUSED */
+int
+spec_kqfilter(v)
+	void *v;
+{
+	struct vop_kqfilter_args /* {
+		struct vnode *a_vp;
+		struct knote *a_kn;
+	} */ *ap = v;
+
+	dev_t dev;
+
+	dev = ap->a_vp->v_rdev;
+	if (cdevsw[major(dev)].d_type & D_KQFILTER)
+		return (*cdevsw[major(dev)].d_kqfilter)(dev, ap->a_kn);
+	return (1);
+}
+
 /*
  * Synch buffers associated with a block device
  */
diff --git a/sys/kern/sys_pipe.c b/sys/kern/sys_pipe.c
index 28dfd3dc210..cfbb2efcd2e 100644
--- a/sys/kern/sys_pipe.c
+++ b/sys/kern/sys_pipe.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: sys_pipe.c,v 1.25 2000/11/16 20:02:17 provos Exp $	*/
+/*	$OpenBSD: sys_pipe.c,v 1.26 2001/03/01 20:54:33 provos Exp $	*/
 
 /*
  * Copyright (c) 1996 John S. Dyson
@@ -67,21 +67,24 @@ int	pipe_read __P((struct file *, off_t *, struct uio *, struct ucred *));
 int	pipe_write __P((struct file *, off_t *, struct uio *, struct ucred *));
 int	pipe_close __P((struct file *, struct proc *));
 int	pipe_select __P((struct file *, int which, struct proc *));
+int	pipe_kqfilter __P((struct file *fp, struct knote *kn));
 int	pipe_ioctl __P((struct file *, u_long, caddr_t, struct proc *));
 
-static struct fileops pipeops =
-    { pipe_read, pipe_write, pipe_ioctl, pipe_select, pipe_close };
+static struct fileops pipeops = {
+	pipe_read, pipe_write, pipe_ioctl, pipe_select, pipe_kqfilter,
+	pipe_close 
+};
 
-int	filt_pipeattach(struct knote *kn);
 void	filt_pipedetach(struct knote *kn);
 int	filt_piperead(struct knote *kn, long hint);
 int	filt_pipewrite(struct knote *kn, long hint);
 
-struct filterops pipe_rwfiltops[] = {
-	{ 1, filt_pipeattach, filt_pipedetach, filt_piperead },
-	{ 1, filt_pipeattach, filt_pipedetach, filt_pipewrite },
-};
+struct filterops pipe_rfiltops =
+	{ 1, NULL, filt_pipedetach, filt_piperead };
+struct filterops pipe_wfiltops =
+	{ 1, NULL, filt_pipedetach, filt_pipewrite };
 
+ 
 /*
  * Default pipe buffer size(s), this can be kind-of large now because pipe
  * space is pageable.  The pipe code will try to maintain locality of
@@ -758,10 +761,21 @@ pipeclose(cpipe)
 #endif
 
 int
-filt_pipeattach(struct knote *kn)
+pipe_kqfilter(struct file *fp, struct knote *kn)
 {
 	struct pipe *rpipe = (struct pipe *)kn->kn_fp->f_data;
 
+	switch (kn->kn_filter) {
+	case EVFILT_READ:
+		kn->kn_fop = &pipe_rfiltops;
+		break;
+	case EVFILT_WRITE:
+		kn->kn_fop = &pipe_wfiltops;
+		break;
+	default:
+		return (1);
+	}
+	
 	SLIST_INSERT_HEAD(&rpipe->pipe_sel.si_note, kn, kn_selnext);
 	return (0);
 }
diff --git a/sys/kern/sys_socket.c b/sys/kern/sys_socket.c
index f385310036a..1d51c9349fa 100644
--- a/sys/kern/sys_socket.c
+++ b/sys/kern/sys_socket.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: sys_socket.c,v 1.4 2000/04/19 08:34:53 csapuntz Exp $	*/
+/*	$OpenBSD: sys_socket.c,v 1.5 2001/03/01 20:54:34 provos Exp $	*/
 /*	$NetBSD: sys_socket.c,v 1.13 1995/08/12 23:59:09 mycroft Exp $	*/
 
 /*
@@ -50,8 +50,10 @@
 #include <net/if.h>
 #include <net/route.h>
 
-struct	fileops socketops =
-    { soo_read, soo_write, soo_ioctl, soo_select, soo_close };
+struct	fileops socketops = {
+	soo_read, soo_write, soo_ioctl, soo_select, soo_kqfilter,
+	soo_close
+};
 
 /* ARGSUSED */
 int
diff --git a/sys/kern/tty.c b/sys/kern/tty.c
index 1a7990146d1..3437a0537dc 100644
--- a/sys/kern/tty.c
+++ b/sys/kern/tty.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: tty.c,v 1.41 2000/07/19 13:37:28 art Exp $	*/
+/*	$OpenBSD: tty.c,v 1.42 2001/03/01 20:54:34 provos Exp $	*/
 /*	$NetBSD: tty.c,v 1.68.4.2 1996/06/06 16:04:52 thorpej Exp $	*/
 
 /*-
@@ -70,6 +70,10 @@ void ttyunblock __P((struct tty *));
 static void ttyecho __P((int, struct tty *));
 static void ttyrubo __P((struct tty *, int));
 static int proc_compare __P((struct proc *, struct proc *));
+int	filt_ttyread __P((struct knote *kn, long hint));
+void 	filt_ttyrdetach __P((struct knote *kn));
+int	filt_ttywrite __P((struct knote *kn, long hint));
+void 	filt_ttywdetach __P((struct knote *kn));
 
 /* Symbolic sleep message strings. */
 char ttclos[]	= "ttycls";
@@ -1049,6 +1053,90 @@ win:			splx(s);
 	return (0);
 }
 
+struct filterops ttyread_filtops =
+	{ 1, NULL, filt_ttyrdetach, filt_ttyread };
+struct filterops ttywrite_filtops =
+	{ 1, NULL, filt_ttywdetach, filt_ttywrite };
+
+int
+ttkqfilter(dev, kn)
+	dev_t dev;
+	struct knote *kn;
+{
+	struct tty *tp = (*cdevsw[major(dev)].d_tty)(dev);
+	struct klist *klist;
+	int s;
+
+	switch (kn->kn_filter) {
+	case EVFILT_READ:
+		klist = &tp->t_rsel.si_note;
+		kn->kn_fop = &ttyread_filtops;
+		break;
+	case EVFILT_WRITE:
+		klist = &tp->t_wsel.si_note;
+		kn->kn_fop = &ttywrite_filtops;
+		break;
+	default:
+		return (1);
+	}
+
+	kn->kn_hook = (caddr_t)dev;
+
+	s = spltty();
+	SLIST_INSERT_HEAD(klist, kn, kn_selnext);
+	splx(s);
+
+	return (0);
+}
+
+void
+filt_ttyrdetach(struct knote *kn)
+{
+	dev_t dev = (dev_t)kn->kn_hook;
+	struct tty *tp = (*cdevsw[major(dev)].d_tty)(dev);
+	int s = spltty();
+
+	SLIST_REMOVE(&tp->t_rsel.si_note, kn, knote, kn_selnext);
+	splx(s);
+}
+
+int
+filt_ttyread(struct knote *kn, long hint)
+{
+	dev_t dev = (dev_t)kn->kn_hook;
+	struct tty *tp = (*cdevsw[major(dev)].d_tty)(dev);
+
+	kn->kn_data = ttnread(tp);
+	if (!ISSET(tp->t_state, CLOCAL) && !ISSET(tp->t_state, TS_CARR_ON)) {
+		kn->kn_flags |= EV_EOF;
+		return (1);
+	}
+	return (kn->kn_data > 0);
+}
+
+void
+filt_ttywdetach(struct knote *kn)
+{
+	dev_t dev = (dev_t)kn->kn_hook;
+	struct tty *tp = (*cdevsw[major(dev)].d_tty)(dev);
+	int s = spltty();
+
+	SLIST_REMOVE(&tp->t_wsel.si_note, kn, knote, kn_selnext);
+	splx(s);
+}
+
+int
+filt_ttywrite(kn, hint)
+	struct knote *kn;
+	long hint;
+{
+	dev_t dev = (dev_t)kn->kn_hook;
+	struct tty *tp = (*cdevsw[major(dev)].d_tty)(dev);
+
+	kn->kn_data = tp->t_outq.c_cc;
+	return (kn->kn_data <= tp->t_lowat);
+}
+
 static int
 ttnread(tp)
 	struct tty *tp;
@@ -1935,6 +2023,7 @@ ttwakeup(tp)
 	if (ISSET(tp->t_state, TS_ASYNC))
 		pgsignal(tp->t_pgrp, SIGIO, 1);
 	wakeup((caddr_t)&tp->t_rawq);
+	KNOTE(&tp->t_rsel.si_note, 0);
 }
 
 /*
diff --git a/sys/kern/uipc_socket.c b/sys/kern/uipc_socket.c
index 8b36265424e..207f52feade 100644
--- a/sys/kern/uipc_socket.c
+++ b/sys/kern/uipc_socket.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: uipc_socket.c,v 1.30 2001/02/07 12:20:42 itojun Exp $	*/
+/*	$OpenBSD: uipc_socket.c,v 1.31 2001/03/01 20:54:34 provos Exp $	*/
 /*	$NetBSD: uipc_socket.c,v 1.21 1996/02/04 02:17:52 christos Exp $	*/
 
 /*
@@ -51,21 +51,19 @@
 #include <sys/signalvar.h>
 #include <sys/resourcevar.h>
 
-int 	filt_sorattach(struct knote *kn);
 void 	filt_sordetach(struct knote *kn);
 int 	filt_soread(struct knote *kn, long hint);
-int 	filt_sowattach(struct knote *kn);
 void 	filt_sowdetach(struct knote *kn);
 int	filt_sowrite(struct knote *kn, long hint);
 int	filt_solisten(struct knote *kn, long hint);
 
 struct filterops solisten_filtops = 
-	{ 1, filt_sorattach, filt_sordetach, filt_solisten };
+	{ 1, NULL, filt_sordetach, filt_solisten };
+struct filterops soread_filtops =
+	{ 1, NULL, filt_sordetach, filt_soread };
+struct filterops sowrite_filtops = 
+	{ 1, NULL, filt_sowdetach, filt_sowrite };
 
-struct filterops so_rwfiltops[] = {
-	{ 1, filt_sorattach, filt_sordetach, filt_soread },
-	{ 1, filt_sowattach, filt_sowdetach, filt_sowrite },
-};
 
 #ifndef SOMINCONN
 #define SOMINCONN 80
@@ -1114,15 +1112,31 @@ sohasoutofband(so)
 }
 
 int
-filt_sorattach(struct knote *kn)
+soo_kqfilter(struct file *fp, struct knote *kn)
 {
 	struct socket *so = (struct socket *)kn->kn_fp->f_data;
-	int s = splnet();
+	struct sockbuf *sb;
+	int s;
 
-	if (so->so_options & SO_ACCEPTCONN)
-		kn->kn_fop = &solisten_filtops;
-	SLIST_INSERT_HEAD(&so->so_rcv.sb_sel.si_note, kn, kn_selnext);
-	so->so_rcv.sb_flags |= SB_KNOTE;
+	switch (kn->kn_filter) {
+	case EVFILT_READ:
+		if (so->so_options & SO_ACCEPTCONN)
+			kn->kn_fop = &solisten_filtops;
+		else
+			kn->kn_fop = &soread_filtops;
+		sb = &so->so_rcv;
+		break;
+	case EVFILT_WRITE:
+		kn->kn_fop = &sowrite_filtops;
+		sb = &so->so_snd;
+		break;
+	default:
+		return (1);
+	}
+
+	s = splnet();
+	SLIST_INSERT_HEAD(&sb->sb_sel.si_note, kn, kn_selnext);
+	sb->sb_flags |= SB_KNOTE;
 	splx(s);
 	return (0);
 }
@@ -1148,25 +1162,16 @@ filt_soread(struct knote *kn, long hint)
 	kn->kn_data = so->so_rcv.sb_cc;
 	if (so->so_state & SS_CANTRCVMORE) {
 		kn->kn_flags |= EV_EOF; 
+		kn->kn_fflags = so->so_error;
 		return (1);
 	}
 	if (so->so_error)	/* temporary udp error */
 		return (1);
+	if (kn->kn_sfflags & NOTE_LOWAT)
+		return (kn->kn_data >= kn->kn_sdata);
 	return (kn->kn_data >= so->so_rcv.sb_lowat);
 }
 
-int
-filt_sowattach(struct knote *kn)
-{
-	struct socket *so = (struct socket *)kn->kn_fp->f_data;
-	int s = splnet();
-
-	SLIST_INSERT_HEAD(&so->so_snd.sb_sel.si_note, kn, kn_selnext);
-	so->so_snd.sb_flags |= SB_KNOTE;
-	splx(s);
-	return (0);
-}
-
 void
 filt_sowdetach(struct knote *kn)
 {
@@ -1188,6 +1193,7 @@ filt_sowrite(struct knote *kn, long hint)
 	kn->kn_data = sbspace(&so->so_snd);
 	if (so->so_state & SS_CANTSENDMORE) {
 		kn->kn_flags |= EV_EOF; 
+		kn->kn_fflags = so->so_error;
 		return (1);
 	}
 	if (so->so_error)	/* temporary udp error */
@@ -1195,6 +1201,8 @@ filt_sowrite(struct knote *kn, long hint)
 	if (((so->so_state & SS_ISCONNECTED) == 0) &&
 	    (so->so_proto->pr_flags & PR_CONNREQUIRED))
 		return (0);
+	if (kn->kn_sfflags & NOTE_LOWAT)
+		return (kn->kn_data >= kn->kn_sdata);
 	return (kn->kn_data >= so->so_snd.sb_lowat);
 }
 
diff --git a/sys/kern/vfs_vnops.c b/sys/kern/vfs_vnops.c
index 6bfcf9614ab..9e1b9907a27 100644
--- a/sys/kern/vfs_vnops.c
+++ b/sys/kern/vfs_vnops.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: vfs_vnops.c,v 1.27 2000/11/21 21:49:57 provos Exp $	*/
+/*	$OpenBSD: vfs_vnops.c,v 1.28 2001/03/01 20:54:34 provos Exp $	*/
 /*	$NetBSD: vfs_vnops.c,v 1.20 1996/02/04 02:18:41 christos Exp $	*/
 
 /*
@@ -61,39 +61,18 @@
 #include <uvm/uvm_extern.h>
 #endif
 
-#include <ufs/ufs/quota.h>
-#include <ufs/ufs/inode.h>
-
 int	vn_read __P((struct file *fp, off_t *off, struct uio *uio, 
 	    struct ucred *cred));
 int	vn_write __P((struct file *fp, off_t *off, struct uio *uio, 
             struct ucred *cred));
 int	vn_select __P((struct file *fp, int which, struct proc *p));
+int	vn_kqfilter __P((struct file *fp, struct knote *kn));
 int 	vn_closefile __P((struct file *fp, struct proc *p));
 int	vn_ioctl __P((struct file *fp, u_long com, caddr_t data,
 	    struct proc *p));
 
 struct 	fileops vnops =
-	{ vn_read, vn_write, vn_ioctl, vn_select, vn_closefile };
-
-static int	filt_nullattach(struct knote *kn);
-static int	filt_vnattach(struct knote *kn);
-static void	filt_vndetach(struct knote *kn);
-static int	filt_vnode(struct knote *kn, long hint);
-static int	filt_vnread(struct knote *kn, long hint);
-
-struct filterops vn_filtops =
-	{ 1, filt_vnattach, filt_vndetach, filt_vnode };
-
-/*
- * XXX
- * filt_vnread is ufs-specific, so the attach routine should really
- * switch out to different filterops based on the vn filetype
- */
-struct filterops vn_rwfiltops[] = {
-	{ 1, filt_vnattach, filt_vndetach, filt_vnread },
-	{ 1, filt_nullattach, NULL, NULL },
-};
+	{ vn_read, vn_write, vn_ioctl, vn_select, vn_kqfilter, vn_closefile };
 
 /*
  * Common code for vnode open operations.
@@ -531,63 +510,9 @@ vn_closefile(fp, p)
 		fp->f_cred, p));
 }
 
-static int
-filt_vnattach(struct knote *kn)
-{
-	struct vnode *vp;
-
-	if (kn->kn_fp->f_type != DTYPE_VNODE)
-		return (EBADF);
-
-	vp = (struct vnode *)kn->kn_fp->f_data;
-
-	/*
-	 * XXX
-	 * this is a hack simply to cause the filter attach to fail
-	 * for non-ufs filesystems, until the support for them is done.
-	 */
-	if ((vp)->v_tag != VT_UFS || (vp)->v_type == VFIFO)
-		return (EOPNOTSUPP);
-
-	simple_lock(&vp->v_selectinfo.vsi_lock);
-	SLIST_INSERT_HEAD(&vp->v_selectinfo.vsi_selinfo.si_note, kn, kn_selnext);
-	simple_unlock(&vp->v_selectinfo.vsi_lock);
-
-	return (0);
-}
-
-static void
-filt_vndetach(struct knote *kn)
-{
-	struct vnode *vp = (struct vnode *)kn->kn_fp->f_data;
-
-	simple_lock(&vp->v_selectinfo.vsi_lock);
-	SLIST_REMOVE(&vp->v_selectinfo.vsi_selinfo.si_note,
-	    kn, knote, kn_selnext);
-	simple_unlock(&vp->v_selectinfo.vsi_lock);
-}
-
-static int
-filt_vnode(struct knote *kn, long hint)
-{
-	if (kn->kn_sfflags & hint)
-		kn->kn_fflags |= hint;
-	return (kn->kn_fflags != 0);
-}
-
-static int
-filt_nullattach(struct knote *kn)
-{
-	return (ENXIO);
-}
-
 /*ARGSUSED*/
-static int
-filt_vnread(struct knote *kn, long hint)
+int
+vn_kqfilter(struct file *fp, struct knote *kn)
 {
-	struct vnode *vp = (struct vnode *)kn->kn_fp->f_data;
-	struct inode *ip = VTOI(vp);
-
-	kn->kn_data = ip->i_ffs_size - kn->kn_fp->f_offset;
-	return (kn->kn_data != 0);
+	return (VOP_KQFILTER(((struct vnode *)fp->f_data), kn));
 }
diff --git a/sys/kern/vnode_if.src b/sys/kern/vnode_if.src
index 722ca9c4fa1..5a98a21d5a6 100644
--- a/sys/kern/vnode_if.src
+++ b/sys/kern/vnode_if.src
@@ -1,4 +1,4 @@
-#	$OpenBSD: vnode_if.src,v 1.9 1998/12/05 16:54:02 csapuntz Exp $
+#	$OpenBSD: vnode_if.src,v 1.10 2001/03/01 20:54:34 provos Exp $
 #	$NetBSD: vnode_if.src,v 1.10 1996/05/11 18:26:27 mycroft Exp $
 #
 # Copyright (c) 1992, 1993
@@ -227,6 +227,14 @@ vop_select {
 };
 
 #
+#% kqfilter	vp	U U U
+#
+vop_kqfilter {
+	IN struct vnode *vp;
+	IN struct knote *kn;
+};
+
+#
 #% revoke	vp	U U U
 #
 vop_revoke {