Add support for poll(2) on files. vop_nopoll() now returns POLLNVAL

if one of the new poll types is requested; hopefully this will not break
any existing code.  (This is done so that programs have a dependable
way of determining whether a filesystem supports the extended poll types
or not.)

The new poll types added are:

	POLLWRITE - file contents may have been modified
	POLLNLINK - file was linked, unlinked, or renamed
	POLLATTRIB - file's attributes may have been changed
	POLLEXTEND - file was extended

Note that the internal operation of poll() means that it is impossible
for two processes to reliably poll for the same event (this could
be fixed but may not be worth it), so it is not possible to rewrite
`tail -f' to use poll at this time.

9 files changed, 291 insertions, 19 deletions

diff --git a/sys/fs/deadfs/dead_vnops.c b/sys/fs/deadfs/dead_vnops.c
index 99f58a6..fb11c2a 100644
--- a/sys/fs/deadfs/dead_vnops.c
+++ b/sys/fs/deadfs/dead_vnops.c
@@ -31,7 +31,7 @@
  * SUCH DAMAGE.
  *
  *	@(#)dead_vnops.c	8.1 (Berkeley) 6/10/93
- * $Id: dead_vnops.c,v 1.21 1997/10/26 20:55:10 phk Exp $
+ * $Id: dead_vnops.c,v 1.22 1997/12/05 19:55:41 bde Exp $
  */
 
 #include <sys/param.h>
@@ -40,20 +40,22 @@
 #include <sys/lock.h>
 #include <sys/vnode.h>
 #include <sys/buf.h>
+#include <sys/poll.h>
 
 static int	chkvnlock __P((struct vnode *));
 /*
  * Prototypes for dead operations on vnodes.
  */
 static int	dead_badop __P((void));
+static int	dead_bmap __P((struct vop_bmap_args *));
+static int	dead_ioctl __P((struct vop_ioctl_args *));
+static int	dead_lock __P((struct vop_lock_args *));
 static int	dead_lookup __P((struct vop_lookup_args *));
 static int	dead_open __P((struct vop_open_args *));
+static int	dead_poll __P((struct vop_poll_args *));
+static int	dead_print __P((struct vop_print_args *));
 static int	dead_read __P((struct vop_read_args *));
 static int	dead_write __P((struct vop_write_args *));
-static int	dead_ioctl __P((struct vop_ioctl_args *));
-static int	dead_lock __P((struct vop_lock_args *));
-static int	dead_bmap __P((struct vop_bmap_args *));
-static int	dead_print __P((struct vop_print_args *));
 
 vop_t **dead_vnodeop_p;
 static struct vnodeopv_entry_desc dead_vnodeop_entries[] = {
@@ -73,6 +75,7 @@ static struct vnodeopv_entry_desc dead_vnodeop_entries[] = {
 	{ &vop_mmap_desc,		(vop_t *) dead_badop },
 	{ &vop_open_desc,		(vop_t *) dead_open },
 	{ &vop_pathconf_desc,		(vop_t *) vop_ebadf },	/* per pathconf(2) */
+	{ &vop_poll_desc,		(vop_t *) dead_poll },
 	{ &vop_print_desc,		(vop_t *) dead_print },
 	{ &vop_read_desc,		(vop_t *) dead_read },
 	{ &vop_readdir_desc,		(vop_t *) vop_ebadf },
@@ -288,3 +291,15 @@ chkvnlock(vp)
 	}
 	return (locked);
 }
+
+/*
+ * Trivial poll routine that always returns POLLHUP.
+ * This is necessary so that a process which is polling a file
+ * gets notified when that file is revoke()d.
+ */
+static int
+dead_poll(ap)
+	struct vop_poll_args *ap;
+{
+	return (POLLHUP);
+}
diff --git a/sys/kern/vfs_default.c b/sys/kern/vfs_default.c
index adebcc7..59f6af4 100644
--- a/sys/kern/vfs_default.c
+++ b/sys/kern/vfs_default.c
@@ -231,13 +231,34 @@ vop_nopoll(ap)
 		struct proc *a_p;
 	} */ *ap;
 {
-
 	/*
-	 * Just return what we were asked for.
+	 * Return true for read/write.  If the user asked for something
+	 * special, return POLLNVAL, so that clients have a way of
+	 * determining reliably whether or not the extended
+	 * functionality is present without hard-coding knowledge
+	 * of specific filesystem implementations.
 	 */
+	if (ap->a_events & ~POLLSTANDARD)
+		return (POLLNVAL);
+
 	return (ap->a_events & (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM));
 }
 
+/*
+ * Implement poll for local filesystems that support it.
+ */
+int
+vop_stdpoll(ap)
+	struct vop_poll_args /* {
+		struct vnode *a_vp;
+		int  a_events;
+		struct ucred *a_cred;
+		struct proc *a_p;
+	} */ *ap;
+{
+	return (vn_pollrecord(ap->a_vp, ap->a_p, ap->a_events));
+}
+
 int
 vop_stdbwrite(ap)
 	struct vop_bwrite_args *ap;
diff --git a/sys/kern/vfs_export.c b/sys/kern/vfs_export.c
index 254e9a7..c978bbf 100644
--- a/sys/kern/vfs_export.c
+++ b/sys/kern/vfs_export.c
@@ -36,7 +36,7 @@
  * SUCH DAMAGE.
  *
  *	@(#)vfs_subr.c	8.31 (Berkeley) 5/26/95
- * $Id: vfs_subr.c,v 1.113 1997/11/12 05:42:15 julian Exp $
+ * $Id: vfs_subr.c,v 1.114 1997/11/22 08:35:39 bde Exp $
  */
 
 /*
@@ -1207,6 +1207,7 @@ vclean(vp, flags, p)
 	 * Done with purge, notify sleepers of the grim news.
 	 */
 	vp->v_op = dead_vnodeop_p;
+	vn_pollgone(vp);
 	vp->v_tag = VT_NON;
 	vp->v_flag &= ~VXLOCK;
 	if (vp->v_flag & VXWANT) {
@@ -2111,3 +2112,86 @@ vbusy(vp)
 	simple_unlock(&vnode_free_list_slock);
 	vp->v_flag &= ~VFREE;
 }
+
+/*
+ * Record a process's interest in events which might happen to
+ * a vnode.  Because poll uses the historic select-style interface
+ * internally, this routine serves as both the ``check for any
+ * pending events'' and the ``record my interest in future events''
+ * functions.  (These are done together, while the lock is held,
+ * to avoid race conditions.)
+ */
+int
+vn_pollrecord(vp, p, events)
+	struct vnode *vp;
+	struct proc *p;
+	short events;
+{
+	simple_lock(&vp->v_pollinfo.vpi_lock);
+	if (vp->v_pollinfo.vpi_revents & events) {
+		/*
+		 * This leaves events we are not interested
+		 * in available for the other process which
+		 * which presumably had requested them
+		 * (otherwise they would never have been
+		 * recorded).
+		 */
+		events &= vp->v_pollinfo.vpi_revents;
+		vp->v_pollinfo.vpi_revents &= ~events;
+
+		simple_unlock(&vp->v_pollinfo.vpi_lock);
+		return events;
+	}
+	vp->v_pollinfo.vpi_events |= events;
+	selrecord(p, &vp->v_pollinfo.vpi_selinfo);
+	simple_unlock(&vp->v_pollinfo.vpi_lock);
+	return 0;
+}
+
+/*
+ * Note the occurrence of an event.  If the VN_POLLEVENT macro is used,
+ * it is possible for us to miss an event due to race conditions, but
+ * that condition is expected to be rare, so for the moment it is the
+ * preferred interface.
+ */
+void
+vn_pollevent(vp, events)
+	struct vnode *vp;
+	short events;
+{
+	simple_lock(&vp->v_pollinfo.vpi_lock);
+	if (vp->v_pollinfo.vpi_events & events) {
+		/*
+		 * We clear vpi_events so that we don't
+		 * call selwakeup() twice if two events are
+		 * posted before the polling process(es) is
+		 * awakened.  This also ensures that we take at
+		 * most one selwakeup() if the polling process
+		 * is no longer interested.  However, it does
+		 * mean that only one event can be noticed at
+		 * a time.  (Perhaps we should only clear those
+		 * event bits which we note?) XXX
+		 */
+		vp->v_pollinfo.vpi_events = 0;	/* &= ~events ??? */
+		vp->v_pollinfo.vpi_revents |= events;
+		selwakeup(&vp->v_pollinfo.vpi_selinfo);
+	}
+	simple_unlock(&vp->v_pollinfo.vpi_lock);
+}
+
+/*
+ * Wake up anyone polling on vp because it is being revoked.
+ * This depends on dead_poll() returning POLLHUP for correct
+ * behavior.
+ */
+void
+vn_pollgone(vp)
+	struct vnode *vp;
+{
+	simple_lock(&vp->v_pollinfo.vpi_lock);
+	if (vp->v_pollinfo.vpi_events) {
+		vp->v_pollinfo.vpi_events = 0;
+		selwakeup(&vp->v_pollinfo.vpi_selinfo);
+	}
+	simple_unlock(&vp->v_pollinfo.vpi_lock);
+}
diff --git a/sys/kern/vfs_subr.c b/sys/kern/vfs_subr.c
index 254e9a7..c978bbf 100644
--- a/sys/kern/vfs_subr.c
+++ b/sys/kern/vfs_subr.c
@@ -36,7 +36,7 @@
  * SUCH DAMAGE.
  *
  *	@(#)vfs_subr.c	8.31 (Berkeley) 5/26/95
- * $Id: vfs_subr.c,v 1.113 1997/11/12 05:42:15 julian Exp $
+ * $Id: vfs_subr.c,v 1.114 1997/11/22 08:35:39 bde Exp $
  */
 
 /*
@@ -1207,6 +1207,7 @@ vclean(vp, flags, p)
 	 * Done with purge, notify sleepers of the grim news.
 	 */
 	vp->v_op = dead_vnodeop_p;
+	vn_pollgone(vp);
 	vp->v_tag = VT_NON;
 	vp->v_flag &= ~VXLOCK;
 	if (vp->v_flag & VXWANT) {
@@ -2111,3 +2112,86 @@ vbusy(vp)
 	simple_unlock(&vnode_free_list_slock);
 	vp->v_flag &= ~VFREE;
 }
+
+/*
+ * Record a process's interest in events which might happen to
+ * a vnode.  Because poll uses the historic select-style interface
+ * internally, this routine serves as both the ``check for any
+ * pending events'' and the ``record my interest in future events''
+ * functions.  (These are done together, while the lock is held,
+ * to avoid race conditions.)
+ */
+int
+vn_pollrecord(vp, p, events)
+	struct vnode *vp;
+	struct proc *p;
+	short events;
+{
+	simple_lock(&vp->v_pollinfo.vpi_lock);
+	if (vp->v_pollinfo.vpi_revents & events) {
+		/*
+		 * This leaves events we are not interested
+		 * in available for the other process which
+		 * which presumably had requested them
+		 * (otherwise they would never have been
+		 * recorded).
+		 */
+		events &= vp->v_pollinfo.vpi_revents;
+		vp->v_pollinfo.vpi_revents &= ~events;
+
+		simple_unlock(&vp->v_pollinfo.vpi_lock);
+		return events;
+	}
+	vp->v_pollinfo.vpi_events |= events;
+	selrecord(p, &vp->v_pollinfo.vpi_selinfo);
+	simple_unlock(&vp->v_pollinfo.vpi_lock);
+	return 0;
+}
+
+/*
+ * Note the occurrence of an event.  If the VN_POLLEVENT macro is used,
+ * it is possible for us to miss an event due to race conditions, but
+ * that condition is expected to be rare, so for the moment it is the
+ * preferred interface.
+ */
+void
+vn_pollevent(vp, events)
+	struct vnode *vp;
+	short events;
+{
+	simple_lock(&vp->v_pollinfo.vpi_lock);
+	if (vp->v_pollinfo.vpi_events & events) {
+		/*
+		 * We clear vpi_events so that we don't
+		 * call selwakeup() twice if two events are
+		 * posted before the polling process(es) is
+		 * awakened.  This also ensures that we take at
+		 * most one selwakeup() if the polling process
+		 * is no longer interested.  However, it does
+		 * mean that only one event can be noticed at
+		 * a time.  (Perhaps we should only clear those
+		 * event bits which we note?) XXX
+		 */
+		vp->v_pollinfo.vpi_events = 0;	/* &= ~events ??? */
+		vp->v_pollinfo.vpi_revents |= events;
+		selwakeup(&vp->v_pollinfo.vpi_selinfo);
+	}
+	simple_unlock(&vp->v_pollinfo.vpi_lock);
+}
+
+/*
+ * Wake up anyone polling on vp because it is being revoked.
+ * This depends on dead_poll() returning POLLHUP for correct
+ * behavior.
+ */
+void
+vn_pollgone(vp)
+	struct vnode *vp;
+{
+	simple_lock(&vp->v_pollinfo.vpi_lock);
+	if (vp->v_pollinfo.vpi_events) {
+		vp->v_pollinfo.vpi_events = 0;
+		selwakeup(&vp->v_pollinfo.vpi_selinfo);
+	}
+	simple_unlock(&vp->v_pollinfo.vpi_lock);
+}
diff --git a/sys/miscfs/deadfs/dead_vnops.c b/sys/miscfs/deadfs/dead_vnops.c
index 99f58a6..fb11c2a 100644
--- a/sys/miscfs/deadfs/dead_vnops.c
+++ b/sys/miscfs/deadfs/dead_vnops.c
@@ -31,7 +31,7 @@
  * SUCH DAMAGE.
  *
  *	@(#)dead_vnops.c	8.1 (Berkeley) 6/10/93
- * $Id: dead_vnops.c,v 1.21 1997/10/26 20:55:10 phk Exp $
+ * $Id: dead_vnops.c,v 1.22 1997/12/05 19:55:41 bde Exp $
  */
 
 #include <sys/param.h>
@@ -40,20 +40,22 @@
 #include <sys/lock.h>
 #include <sys/vnode.h>
 #include <sys/buf.h>
+#include <sys/poll.h>
 
 static int	chkvnlock __P((struct vnode *));
 /*
  * Prototypes for dead operations on vnodes.
  */
 static int	dead_badop __P((void));
+static int	dead_bmap __P((struct vop_bmap_args *));
+static int	dead_ioctl __P((struct vop_ioctl_args *));
+static int	dead_lock __P((struct vop_lock_args *));
 static int	dead_lookup __P((struct vop_lookup_args *));
 static int	dead_open __P((struct vop_open_args *));
+static int	dead_poll __P((struct vop_poll_args *));
+static int	dead_print __P((struct vop_print_args *));
 static int	dead_read __P((struct vop_read_args *));
 static int	dead_write __P((struct vop_write_args *));
-static int	dead_ioctl __P((struct vop_ioctl_args *));
-static int	dead_lock __P((struct vop_lock_args *));
-static int	dead_bmap __P((struct vop_bmap_args *));
-static int	dead_print __P((struct vop_print_args *));
 
 vop_t **dead_vnodeop_p;
 static struct vnodeopv_entry_desc dead_vnodeop_entries[] = {
@@ -73,6 +75,7 @@ static struct vnodeopv_entry_desc dead_vnodeop_entries[] = {
 	{ &vop_mmap_desc,		(vop_t *) dead_badop },
 	{ &vop_open_desc,		(vop_t *) dead_open },
 	{ &vop_pathconf_desc,		(vop_t *) vop_ebadf },	/* per pathconf(2) */
+	{ &vop_poll_desc,		(vop_t *) dead_poll },
 	{ &vop_print_desc,		(vop_t *) dead_print },
 	{ &vop_read_desc,		(vop_t *) dead_read },
 	{ &vop_readdir_desc,		(vop_t *) vop_ebadf },
@@ -288,3 +291,15 @@ chkvnlock(vp)
 	}
 	return (locked);
 }
+
+/*
+ * Trivial poll routine that always returns POLLHUP.
+ * This is necessary so that a process which is polling a file
+ * gets notified when that file is revoke()d.
+ */
+static int
+dead_poll(ap)
+	struct vop_poll_args *ap;
+{
+	return (POLLHUP);
+}
diff --git a/sys/sys/poll.h b/sys/sys/poll.h
index 425ee1d..89468eb 100644
--- a/sys/sys/poll.h
+++ b/sys/sys/poll.h
@@ -25,7 +25,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *	$Id: poll.h,v 1.1 1997/09/14 02:20:56 peter Exp $
+ *	$Id: poll.h,v 1.2 1997/09/14 05:38:03 peter Exp $
  */
 
 #ifndef _SYS_POLL_H_
@@ -63,6 +63,15 @@ struct pollfd {
 #define	POLLWRBAND	0x0100		/* OOB/Urgent data can be written */
 
 /*
+ * FreeBSD extensions: polling on a regular file might return one
+ * of these events (currently only supported on UFS).
+ */
+#define	POLLEXTEND	0x0200		/* file may have been extended */
+#define	POLLATTRIB	0x0400		/* file attributes may have changed */
+#define	POLLNLINK	0x0800		/* (un)link/rename may have happened */
+#define	POLLWRITE	0x1000		/* file's contents may have changed */
+
+/*
  * These events are set if they occur regardless of whether they were
  * requested.
  */
@@ -70,6 +79,9 @@ struct pollfd {
 #define	POLLHUP		0x0010		/* file descriptor was "hung up" */
 #define	POLLNVAL	0x0020		/* requested events "invalid" */
 
+#define	POLLSTANDARD	(POLLIN|POLLPRI|POLLOUT|POLLRDNORM|POLLRDBAND|\
+			 POLLWRBAND|POLLERR|POLLHUP|POLLNVAL)
+
 /*
  * Request that poll wait forever.
  * XXX this is in stropts.h in SYSV, and not #included by poll.h
diff --git a/sys/sys/vnode.h b/sys/sys/vnode.h
index 08be466..fec331a 100644
--- a/sys/sys/vnode.h
+++ b/sys/sys/vnode.h
@@ -31,13 +31,14 @@
  * SUCH DAMAGE.
  *
  *	@(#)vnode.h	8.7 (Berkeley) 2/4/94
- * $Id: vnode.h,v 1.57 1997/11/22 08:35:43 bde Exp $
+ * $Id: vnode.h,v 1.58 1997/12/05 19:55:49 bde Exp $
  */
 
 #ifndef _SYS_VNODE_H_
 #define	_SYS_VNODE_H_
 
 #include <sys/queue.h>
+#include <sys/select.h>		/* needed for struct selinfo in vnodes */
 
 #include <machine/lock.h>
 
@@ -78,6 +79,7 @@ struct namecache;
  * v_mntvnodes is locked by the global mntvnodes simple lock.
  * v_flag, v_usecount, v_holdcount and v_writecount are
  *    locked by the v_interlock simple lock.
+ * v_pollinfo is locked by the lock contained inside it.
  */
 struct vnode {
 	u_long	v_flag;				/* vnode flags (see below) */
@@ -114,12 +116,24 @@ struct vnode {
 	TAILQ_HEAD(, namecache) v_cache_dst;	/* Cache entries to us */
 	struct	vnode *v_dd;			/* .. vnode */
 	u_long	v_ddid;				/* .. capability identifier */
+	struct	{
+		struct	simplelock vpi_lock;	/* lock to protect below */
+		struct	selinfo vpi_selinfo;	/* identity of poller(s) */
+		short	vpi_events;		/* what they are looking for */
+		short	vpi_revents;		/* what has happened */
+	} v_pollinfo;
 };
 #define	v_mountedhere	v_un.vu_mountedhere
 #define	v_socket	v_un.vu_socket
 #define	v_specinfo	v_un.vu_specinfo
 #define	v_fifoinfo	v_un.vu_fifoinfo
 
+#define	VN_POLLEVENT(vp, events)				\
+	do {							\
+		if ((vp)->v_pollinfo.vpi_events & (events))	\
+			vn_pollevent((vp), (events));		\
+	} while (0)
+
 /*
  * Vnode flags.
  */
@@ -473,6 +487,9 @@ int 	vn_close __P((struct vnode *vp,
 	    int flags, struct ucred *cred, struct proc *p));
 int	vn_lock __P((struct vnode *vp, int flags, struct proc *p));
 int 	vn_open __P((struct nameidata *ndp, int fmode, int cmode));
+void	vn_pollevent __P((struct vnode *vp, int events));
+void	vn_pollgone __P((struct vnode *vp));
+int	vn_pollrecord __P((struct vnode *vp, struct proc *p, int events));
 int 	vn_rdwr __P((enum uio_rw rw, struct vnode *vp, caddr_t base,
 	    int len, off_t offset, enum uio_seg segflg, int ioflg,
 	    struct ucred *cred, int *aresid, struct proc *p));
@@ -490,6 +507,7 @@ int	vop_nolock __P((struct vop_lock_args *));
 int	vop_nopoll __P((struct vop_poll_args *));
 int	vop_nounlock __P((struct vop_unlock_args *));
 int	vop_stdpathconf __P((struct vop_pathconf_args *));
+int	vop_stdpoll __P((struct vop_poll_args *));
 int	vop_revoke __P((struct vop_revoke_args *));
 int	vop_sharedlock __P((struct vop_lock_args *));
 int	vop_eopnotsupp __P((struct vop_generic_args *ap));
diff --git a/sys/ufs/ufs/ufs_readwrite.c b/sys/ufs/ufs/ufs_readwrite.c
index f9f6d06..35da9cd 100644
--- a/sys/ufs/ufs/ufs_readwrite.c
+++ b/sys/ufs/ufs/ufs_readwrite.c
@@ -31,7 +31,7 @@
  * SUCH DAMAGE.
  *
  *	@(#)ufs_readwrite.c	8.11 (Berkeley) 5/8/95
- * $Id: ufs_readwrite.c,v 1.32 1997/10/16 10:50:21 phk Exp $
+ * $Id: ufs_readwrite.c,v 1.33 1997/10/16 20:32:39 phk Exp $
  */
 
 #ifdef LFS_READWRITE
@@ -55,6 +55,7 @@
 #include <vm/vm.h>
 #include <vm/vm_pager.h>
 #include <vm/vnode_pager.h>
+#include <sys/poll.h>
 #endif
 
 /*
@@ -187,9 +188,10 @@ WRITE(ap)
 	struct proc *p;
 	ufs_daddr_t lbn;
 	off_t osize;
-	int blkoffset, error, flags, ioflag, resid, size, xfersize;
+	int blkoffset, error, extended, flags, ioflag, resid, size, xfersize;
 	struct timeval tv;
 
+	extended = 0;
 	ioflag = ap->a_ioflag;
 	uio = ap->a_uio;
 	vp = ap->a_vp;
@@ -264,6 +266,7 @@ WRITE(ap)
 
 		if (uio->uio_offset + xfersize > ip->i_size) {
 			ip->i_size = uio->uio_offset + xfersize;
+			extended = 1;
 		}
 
 		size = BLKSIZE(fs, ip, lbn) - bp->b_resid;
@@ -314,6 +317,9 @@ WRITE(ap)
 		gettime(&tv);
 		error = UFS_UPDATE(vp, &tv, &tv, 1);
 	}
+	if (!error)
+		VN_POLLEVENT(vp, POLLWRITE | (extended ? POLLEXTEND : 0));
+
 	return (error);
 }
 
diff --git a/sys/ufs/ufs/ufs_vnops.c b/sys/ufs/ufs/ufs_vnops.c
index a160af3..ffec862 100644
--- a/sys/ufs/ufs/ufs_vnops.c
+++ b/sys/ufs/ufs/ufs_vnops.c
@@ -36,7 +36,7 @@
  * SUCH DAMAGE.
  *
  *	@(#)ufs_vnops.c	8.27 (Berkeley) 5/27/95
- * $Id: ufs_vnops.c,v 1.70 1997/12/12 14:14:44 peter Exp $
+ * $Id: ufs_vnops.c,v 1.71 1997/12/13 12:30:34 bde Exp $
  */
 
 #include "opt_quota.h"
@@ -55,6 +55,7 @@
 #include <sys/malloc.h>
 #include <sys/dirent.h>
 #include <sys/lockf.h>
+#include <sys/poll.h>
 
 #include <miscfs/specfs/specdev.h>
 #include <miscfs/fifofs/fifo.h>
@@ -135,6 +136,7 @@ ufs_create(ap)
 	    ap->a_dvp, ap->a_vpp, ap->a_cnp);
 	if (error)
 		return (error);
+	VN_POLLEVENT(ap->a_dvp, POLLWRITE);
 	return (0);
 }
 
@@ -160,6 +162,7 @@ ufs_mknod(ap)
 	    ap->a_dvp, vpp, ap->a_cnp);
 	if (error)
 		return (error);
+	VN_POLLEVENT(ap->a_dvp, POLLWRITE);
 	ip = VTOI(*vpp);
 	ip->i_flag |= IN_ACCESS | IN_CHANGE | IN_UPDATE;
 	if (vap->va_rdev != VNOVAL) {
@@ -469,6 +472,7 @@ ufs_setattr(ap)
 			return (EROFS);
 		error = ufs_chmod(vp, (int)vap->va_mode, cred, p);
 	}
+	VN_POLLEVENT(vp, POLLATTRIB);
 	return (error);
 }
 
@@ -650,6 +654,8 @@ ufs_remove(ap)
 		ip->i_nlink--;
 		ip->i_flag |= IN_CHANGE;
 	}
+	VN_POLLEVENT(vp, POLLNLINK);
+	VN_POLLEVENT(dvp, POLLWRITE);
 out:
 	if (dvp == vp)
 		vrele(vp);
@@ -719,6 +725,8 @@ out1:
 	if (tdvp != vp)
 		VOP_UNLOCK(vp, 0, p);
 out2:
+	VN_POLLEVENT(vp, POLLNLINK);
+	VN_POLLEVENT(tdvp, POLLWRITE);
 	vput(tdvp);
 	return (error);
 }
@@ -936,6 +944,7 @@ abortit:
 		oldparent = dp->i_number;
 		doingdirectory++;
 	}
+	VN_POLLEVENT(fdvp, POLLWRITE);
 	vrele(fdvp);
 
 	/*
@@ -1030,6 +1039,7 @@ abortit:
 			}
 			goto bad;
 		}
+		VN_POLLEVENT(tdvp, POLLWRITE);
 		vput(tdvp);
 	} else {
 		if (xp->i_dev != dp->i_dev || xp->i_dev != ip->i_dev)
@@ -1085,6 +1095,7 @@ abortit:
 			dp->i_nlink--;
 			dp->i_flag |= IN_CHANGE;
 		}
+		VN_POLLEVENT(tdvp, POLLWRITE);
 		vput(tdvp);
 		/*
 		 * Adjust the link count of the target to
@@ -1104,6 +1115,7 @@ abortit:
 			    tcnp->cn_cred, tcnp->cn_proc);
 		}
 		xp->i_flag |= IN_CHANGE;
+		VN_POLLEVENT(tvp, POLLNLINK);
 		vput(tvp);
 		xp = NULL;
 	}
@@ -1381,6 +1393,7 @@ ufs_mkdir(ap)
 		dp->i_nlink--;
 		dp->i_flag |= IN_CHANGE;
 	}
+	VN_POLLEVENT(dvp, POLLWRITE);
 bad:
 	/*
 	 * No need to do an explicit VOP_TRUNCATE here, vrele will do this
@@ -1444,6 +1457,7 @@ ufs_rmdir(ap)
 	error = ufs_dirremove(dvp, cnp);
 	if (error)
 		goto out;
+	VN_POLLEVENT(dvp, POLLWRITE|POLLNLINK);
 	dp->i_nlink--;
 	dp->i_flag |= IN_CHANGE;
 	cache_purge(dvp);
@@ -1464,6 +1478,7 @@ ufs_rmdir(ap)
 	error = UFS_TRUNCATE(vp, (off_t)0, IO_SYNC, cnp->cn_cred,
 	    cnp->cn_proc);
 	cache_purge(ITOV(ip));
+	VN_POLLEVENT(vp, POLLNLINK);
 out:
 	if (dvp)
 		vput(dvp);
@@ -1492,6 +1507,7 @@ ufs_symlink(ap)
 	    vpp, ap->a_cnp);
 	if (error)
 		return (error);
+	VN_POLLEVENT(ap->a_dvp, POLLWRITE);
 	vp = *vpp;
 	len = strlen(ap->a_target);
 	if (len < vp->v_mount->mnt_maxsymlinklen) {
@@ -2132,6 +2148,7 @@ static struct vnodeopv_entry_desc ufs_vnodeop_entries[] = {
 	{ &vop_mmap_desc,		(vop_t *) ufs_mmap },
 	{ &vop_open_desc,		(vop_t *) ufs_open },
 	{ &vop_pathconf_desc,		(vop_t *) ufs_pathconf },
+	{ &vop_poll_desc,		(vop_t *) vop_stdpoll },
 	{ &vop_print_desc,		(vop_t *) ufs_print },
 	{ &vop_readdir_desc,		(vop_t *) ufs_readdir },
 	{ &vop_readlink_desc,		(vop_t *) ufs_readlink },