support for kernel events on vnodes, from jlemon@freebsd.org, okay art@

2 files changed, 89 insertions, 6 deletions

diff --git a/sys/kern/kern_event.c b/sys/kern/kern_event.c
index 4c5fed5e9ac..d407ba8ad27 100644
--- a/sys/kern/kern_event.c
+++ b/sys/kern/kern_event.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kern_event.c,v 1.5 2000/11/18 22:16:49 provos Exp $	*/
+/*	$OpenBSD: kern_event.c,v 1.6 2000/11/21 21:49:57 provos Exp $	*/
 
 /*-
  * Copyright (c) 1999,2000 Jonathan Lemon <jlemon@FreeBSD.org>
@@ -100,8 +100,8 @@ extern struct filterops so_rwfiltops[];
 extern struct filterops pipe_rwfiltops[];
 #ifdef notyet
 extern struct filterops fifo_rwfiltops[];
-extern struct filterops vn_rwfiltops[];
 #endif
+extern struct filterops vn_rwfiltops[];
 
 struct filterops kq_rwfiltops[] = {
     { 1, filt_kqattach, filt_kqdetach, filt_kqueue },
@@ -111,8 +111,8 @@ struct filterops kq_rwfiltops[] = {
 extern struct filterops sig_filtops;
 #ifdef notyet
 extern struct filterops aio_filtops;
-extern struct filterops vn_filtops;
 #endif
+extern struct filterops vn_filtops;
 
 struct filterops rwtype_filtops =
 	{ 1, filt_rwtypattach, NULL, NULL };
@@ -125,7 +125,7 @@ struct filterops proc_filtops =
  */
 struct filterops *rwtypfilt_sw[] = {
 	NULL,				/* 0 */
-	NULL, /* vn_rwfiltops, */	/* DTYPE_VNODE */
+	vn_rwfiltops,			/* DTYPE_VNODE */
 	so_rwfiltops,			/* DTYPE_SOCKET */
 	pipe_rwfiltops,			/* DTYPE_PIPE */
 	/* fifo_rwfiltops, */		/* DTYPE_FIFO */
@@ -139,7 +139,7 @@ struct filterops *sysfilt_ops[] = {
 	&rwtype_filtops,		/* EVFILT_READ */
 	&rwtype_filtops,		/* EVFILT_WRITE */
 	NULL, /*&aio_filtops,*/		/* EVFILT_AIO */
-	NULL, /*&vn_filtops,*/		/* EVFILT_VNODE */
+	&vn_filtops,			/* EVFILT_VNODE */
 	&proc_filtops,			/* EVFILT_PROC */
 	&sig_filtops,			/* EVFILT_SIGNAL */
 };
diff --git a/sys/kern/vfs_vnops.c b/sys/kern/vfs_vnops.c
index b9435c46086..6bfcf9614ab 100644
--- a/sys/kern/vfs_vnops.c
+++ b/sys/kern/vfs_vnops.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: vfs_vnops.c,v 1.26 2000/04/25 02:10:04 deraadt Exp $	*/
+/*	$OpenBSD: vfs_vnops.c,v 1.27 2000/11/21 21:49:57 provos Exp $	*/
 /*	$NetBSD: vfs_vnops.c,v 1.20 1996/02/04 02:18:41 christos Exp $	*/
 
 /*
@@ -61,6 +61,9 @@
 #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, 
@@ -73,6 +76,25 @@ int	vn_ioctl __P((struct file *fp, u_long com, caddr_t data,
 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 },
+};
+
 /*
  * Common code for vnode open operations.
  * Check permissions, and call the VOP_OPEN or VOP_CREATE routine.
@@ -508,3 +530,64 @@ vn_closefile(fp, p)
 	return (vn_close(((struct vnode *)fp->f_data), fp->f_flag,
 		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)
+{
+	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);
+}