Second half of the dev_t cleanup.

The big lines are:
	NODEV -> NULL
	NOUDEV -> NODEV
	udev_t -> dev_t
	udev2dev() -> findcdev()

Various minor adjustments including handling of userland access to kernel
space struct cdev etc.

11 files changed, 57 insertions, 63 deletions

diff --git a/sys/kern/kern_acct.c b/sys/kern/kern_acct.c
index 63d7891..5dca0f6 100644
--- a/sys/kern/kern_acct.c
+++ b/sys/kern/kern_acct.c
@@ -285,7 +285,7 @@ acct_process(td)
 	if ((p->p_flag & P_CONTROLT) && p->p_pgrp->pg_session->s_ttyp)
 		acct.ac_tty = dev2udev(p->p_pgrp->pg_session->s_ttyp->t_dev);
 	else
-		acct.ac_tty = NOUDEV;
+		acct.ac_tty = NODEV;
 	SESS_UNLOCK(p->p_session);
 
 	/* (8) The boolean flags that tell how the process terminated, etc. */
diff --git a/sys/kern/kern_conf.c b/sys/kern/kern_conf.c
index 216a777..b417b73 100644
--- a/sys/kern/kern_conf.c
+++ b/sys/kern/kern_conf.c
@@ -51,7 +51,7 @@ extern unsigned char reserved_majors[256];
 
 /*
  * This is the number of hash-buckets.  Experiements with 'real-life'
- * udev_t's show that a prime halfway between two powers of two works
+ * dev_t's show that a prime halfway between two powers of two works
  * best.
  */
 #define DEVT_HASH 83
@@ -70,6 +70,8 @@ SYSCTL_INT(_debug, OID_AUTO, free_devt, CTLFLAG_RW, &free_devt, 0, "");
 
 static struct mtx devmtx;
 static void freedev(struct cdev *dev);
+static struct cdev *newdev(int x, int y);
+
 
 static void
 devlock(void)
@@ -125,8 +127,6 @@ cdevsw_rel(struct cdevsw *csw)
 	devunlock();
 }
 
-static struct cdev *makedev(int x, int y);
-
 int
 nullop(void)
 {
@@ -247,16 +247,16 @@ devsw(struct cdev *dev)
 int
 major(struct cdev *x)
 {
-	if (x == NODEV)
-		return NOUDEV;
+	if (x == NULL)
+		return NODEV;
 	return((x->si_udev >> 8) & 0xff);
 }
 
 int
 minor(struct cdev *x)
 {
-	if (x == NODEV)
-		return NOUDEV;
+	if (x == NULL)
+		return NODEV;
 	return(x->si_udev & 0xffff00ff);
 }
 
@@ -265,8 +265,8 @@ dev2unit(struct cdev *x)
 {
 	int i;
 
-	if (x == NODEV)
-		return NOUDEV;
+	if (x == NULL)
+		return NODEV;
 	i = minor(x);
 	return ((i & 0xff) | (i >> 8));
 }
@@ -304,14 +304,14 @@ allocdev(void)
 }
 
 static struct cdev *
-makedev(int x, int y)
+newdev(int x, int y)
 {
 	struct cdev *si;
-	udev_t	udev;
+	dev_t	udev;
 	int hash;
 
-	if (x == umajor(NOUDEV) && y == uminor(NOUDEV))
-		panic("makedev of NOUDEV");
+	if (x == umajor(NODEV) && y == uminor(NODEV))
+		panic("newdev of NODEV");
 	udev = (x << 8) | y;
 	hash = udev % DEVT_HASH;
 	LIST_FOREACH(si, &dev_hash[hash], si_hash) {
@@ -337,48 +337,42 @@ freedev(struct cdev *dev)
 	}
 }
 
-udev_t
+dev_t
 dev2udev(struct cdev *x)
 {
-	if (x == NODEV)
-		return (NOUDEV);
+	if (x == NULL)
+		return (NODEV);
 	return (x->si_udev);
 }
 
 struct cdev *
-udev2dev(udev_t udev)
+findcdev(dev_t udev)
 {
 	struct cdev *si;
 	int hash;
 
-	if (udev == NOUDEV)
-		return (NODEV);
+	if (udev == NODEV)
+		return (NULL);
 	hash = udev % DEVT_HASH;
 	LIST_FOREACH(si, &dev_hash[hash], si_hash) {
 		if (si->si_udev == udev)
 			return (si);
 	}
-	return (NODEV);
+	return (NULL);
 }
 
 int
-uminor(udev_t dev)
+uminor(dev_t dev)
 {
 	return (dev & 0xffff00ff);
 }
 
 int
-umajor(udev_t dev)
+umajor(dev_t dev)
 {
 	return ((dev & 0xff00) >> 8);
 }
 
-udev_t
-makeudev(int x, int y)
-{
-	return ((x << 8) | y);
-}
-
 static void
 find_major(struct cdevsw *devsw)
 {
@@ -479,7 +473,7 @@ make_dev(struct cdevsw *devsw, int minornr, uid_t uid, gid_t gid, int perms, con
 
 	if (!(devsw->d_flags & D_INIT))
 		prep_cdevsw(devsw);
-	dev = makedev(devsw->d_maj, minornr);
+	dev = newdev(devsw->d_maj, minornr);
 	if (dev->si_flags & SI_CHEAPCLONE &&
 	    dev->si_flags & SI_NAMED &&
 	    dev->si_devsw == devsw) {
@@ -750,7 +744,7 @@ clone_create(struct clonedevs **cdp, struct cdevsw *csw, int *up, struct cdev **
 	}
 	if (unit == -1)
 		unit = low & CLONE_UNITMASK;
-	dev = makedev(csw->d_maj, unit2minor(unit | extra));
+	dev = newdev(csw->d_maj, unit2minor(unit | extra));
 	KASSERT(!(dev->si_flags & SI_CLONELIST),
 	    ("Dev %p should not be on clonelist", dev));
 	if (dl != NULL)
@@ -794,16 +788,16 @@ static int
 sysctl_devname(SYSCTL_HANDLER_ARGS)
 {
 	int error;
-	udev_t ud;
+	dev_t ud;
 	struct cdev *dev;
 
 	error = SYSCTL_IN(req, &ud, sizeof (ud));
 	if (error)
 		return (error);
-	if (ud == NOUDEV)
+	if (ud == NODEV)
 		return(EINVAL);
-	dev = udev2dev(ud);
-	if (dev == NODEV)
+	dev = findcdev(ud);
+	if (dev == NULL)
 		error = ENOENT;
 	else
 		error = SYSCTL_OUT(req, dev->si_name, strlen(dev->si_name) + 1);
diff --git a/sys/kern/kern_proc.c b/sys/kern/kern_proc.c
index daf51b0..c757124 100644
--- a/sys/kern/kern_proc.c
+++ b/sys/kern/kern_proc.c
@@ -800,7 +800,7 @@ fill_kinfo_thread(struct thread *td, struct kinfo_proc *kp)
 		if (tp->t_session)
 			kp->ki_tsid = tp->t_session->s_sid;
 	} else
-		kp->ki_tdev = NOUDEV;
+		kp->ki_tdev = NODEV;
 	if (p->p_comm[0] != '\0') {
 		strlcpy(kp->ki_comm, p->p_comm, sizeof(kp->ki_comm));
 		strlcpy(kp->ki_ocomm, p->p_comm, sizeof(kp->ki_ocomm));
@@ -1012,7 +1012,7 @@ sysctl_kern_proc(SYSCTL_HANDLER_ARGS)
 				SESS_LOCK(p->p_session);
 				if (p->p_session->s_ttyp == NULL ||
 				    dev2udev(p->p_session->s_ttyp->t_dev) != 
-				    (udev_t)name[0]) {
+				    (dev_t)name[0]) {
 					SESS_UNLOCK(p->p_session);
 					PROC_UNLOCK(p);
 					continue;
diff --git a/sys/kern/kern_shutdown.c b/sys/kern/kern_shutdown.c
index 49c6a41..491bc9e 100644
--- a/sys/kern/kern_shutdown.c
+++ b/sys/kern/kern_shutdown.c
@@ -324,7 +324,7 @@ boot(int howto)
 		for (bp = &buf[nbuf]; --bp >= buf; ) {
 			if (((bp->b_flags&B_INVAL) == 0 && BUF_REFCNT(bp)) ||
 			    ((bp->b_flags & (B_DELWRI|B_INVAL)) == B_DELWRI)) {
-				if (bp->b_dev == NODEV) {
+				if (bp->b_dev == NULL) {
 					TAILQ_REMOVE(&mountlist,
 					    bp->b_vp->v_mount, mnt_list);
 					continue;
diff --git a/sys/kern/tty_cons.c b/sys/kern/tty_cons.c
index a9bea7c..e44ea5f 100644
--- a/sys/kern/tty_cons.c
+++ b/sys/kern/tty_cons.c
@@ -103,7 +103,7 @@ static STAILQ_HEAD(, cn_device) cn_devlist =
 	(cnd == NULL || cnd->cnd_vp == NULL ||				\
 	    (cnd->cnd_vp->v_type == VBAD && !cn_devopen(cnd, td, 1)))
 
-static udev_t	cn_udev_t;
+static dev_t	cn_udev_t;
 SYSCTL_OPAQUE(_machdep, CPU_CONSDEV, consdev, CTLFLAG_RD,
 	&cn_udev_t, sizeof cn_udev_t, "T,struct cdev *", "");
 
@@ -371,9 +371,9 @@ sysctl_kern_consmute(SYSCTL_HANDLER_ARGS)
 	if (error != 0 || req->newptr == NULL)
 		return (error);
 	if (ocn_mute && !cn_mute && cn_is_open)
-		error = cnopen(NODEV, openflag, 0, curthread);
+		error = cnopen(NULL, openflag, 0, curthread);
 	else if (!ocn_mute && cn_mute && cn_is_open) {
-		error = cnclose(NODEV, openflag, 0, curthread);
+		error = cnclose(NULL, openflag, 0, curthread);
 		cn_is_open = 1;		/* XXX hack */
 	}
 	return (error);
diff --git a/sys/kern/tty_pty.c b/sys/kern/tty_pty.c
index b4082a3..1e5d202 100644
--- a/sys/kern/tty_pty.c
+++ b/sys/kern/tty_pty.c
@@ -143,7 +143,7 @@ ptyinit(struct cdev *devc)
 	n = minor(devc);
 	/* For now we only map the lower 8 bits of the minor */
 	if (n & ~0xff)
-		return (NODEV);
+		return (NULL);
 
 	devc->si_flags &= ~SI_CHEAPCLONE;
 
@@ -777,7 +777,7 @@ pty_clone(void *arg, char *name, int namelen, struct cdev **dev)
 {
 	int u;
 
-	if (*dev != NODEV)
+	if (*dev != NULL)
 		return;
 	if (bcmp(name, "pty", 3) != 0)
 		return;
diff --git a/sys/kern/tty_tty.c b/sys/kern/tty_tty.c
index 85b0eac..e467dd3 100644
--- a/sys/kern/tty_tty.c
+++ b/sys/kern/tty_tty.c
@@ -58,7 +58,7 @@ static void
 ctty_clone(void *arg, char *name, int namelen, struct cdev **dev)
 {
 
-	if (*dev != NODEV)
+	if (*dev != NULL)
 		return;
 	if (strcmp(name, "tty"))
 		return;
diff --git a/sys/kern/uipc_usrreq.c b/sys/kern/uipc_usrreq.c
index 18a4274..16d80b4 100644
--- a/sys/kern/uipc_usrreq.c
+++ b/sys/kern/uipc_usrreq.c
@@ -447,7 +447,7 @@ uipc_sense(struct socket *so, struct stat *sb)
 		so2 = unp->unp_conn->unp_socket;
 		sb->st_blksize += so2->so_rcv.sb_cc;
 	}
-	sb->st_dev = NOUDEV;
+	sb->st_dev = NODEV;
 	if (unp->unp_ino == 0)
 		unp->unp_ino = (++unp_ino == 0) ? ++unp_ino : unp_ino;
 	sb->st_ino = unp->unp_ino;
diff --git a/sys/kern/vfs_bio.c b/sys/kern/vfs_bio.c
index 19b6726..1bfb331 100644
--- a/sys/kern/vfs_bio.c
+++ b/sys/kern/vfs_bio.c
@@ -517,7 +517,7 @@ bufinit(void)
 		bp = &buf[i];
 		bzero(bp, sizeof *bp);
 		bp->b_flags = B_INVAL;	/* we're just an empty header */
-		bp->b_dev = NODEV;
+		bp->b_dev = NULL;
 		bp->b_rcred = NOCRED;
 		bp->b_wcred = NOCRED;
 		bp->b_qindex = QUEUE_EMPTY;
@@ -1413,7 +1413,7 @@ brelse(struct buf * bp)
 			bp->b_qindex = QUEUE_EMPTY;
 		}
 		TAILQ_INSERT_HEAD(&bufqueues[bp->b_qindex], bp, b_freelist);
-		bp->b_dev = NODEV;
+		bp->b_dev = NULL;
 	/* buffers with junk contents */
 	} else if (bp->b_flags & (B_INVAL | B_NOCACHE | B_RELBUF) ||
 	    (bp->b_ioflags & BIO_ERROR)) {
@@ -1423,7 +1423,7 @@ brelse(struct buf * bp)
 			panic("losing buffer 2");
 		bp->b_qindex = QUEUE_CLEAN;
 		TAILQ_INSERT_HEAD(&bufqueues[QUEUE_CLEAN], bp, b_freelist);
-		bp->b_dev = NODEV;
+		bp->b_dev = NULL;
 	/* remaining buffers */
 	} else {
 		if (bp->b_flags & B_DELWRI)
@@ -1917,7 +1917,7 @@ restart:
 		bp->b_ioflags = 0;
 		bp->b_xflags = 0;
 		bp->b_vflags = 0;
-		bp->b_dev = NODEV;
+		bp->b_dev = NULL;
 		bp->b_vp = NULL;
 		bp->b_blkno = bp->b_lblkno = 0;
 		bp->b_offset = NOOFFSET;
diff --git a/sys/kern/vfs_mount.c b/sys/kern/vfs_mount.c
index 8eaa6e9..82086ad 100644
--- a/sys/kern/vfs_mount.c
+++ b/sys/kern/vfs_mount.c
@@ -147,7 +147,7 @@ static char *cdrom_rootdevnames[] = {
 /* legacy find-root code */
 char		*rootdevnames[2] = {NULL, NULL};
 static int	setrootbyname(char *name);
-struct cdev *rootdev = NODEV;
+struct cdev *rootdev = NULL;
 
 /*
  * Has to be dynamic as the value of rootdev can change; however, it can't
@@ -162,7 +162,7 @@ sysctl_rootdev(SYSCTL_HANDLER_ARGS)
 	/* _RD prevents this from happening. */
 	KASSERT(req->newptr == NULL, ("Attempt to change root device name"));
 
-	if (rootdev != NODEV)
+	if (rootdev != NULL)
 		error = sysctl_handle_string(oidp, rootdev->si_name, 0, req);
 	else
 		error = sysctl_handle_string(oidp, "", 0, req);
@@ -1339,7 +1339,7 @@ vfs_mountroot_try(char *mountfrom)
 		printf("setrootbyname failed\n");
 
 	/* If the root device is a type "memory disk", mount RW */
-	if (rootdev != NODEV && devsw(rootdev) != NULL) {
+	if (rootdev != NULL && devsw(rootdev) != NULL) {
 		devname = devtoname(rootdev);
 		if (devname[0] == 'm' && devname[1] == 'd')
 			mp->mnt_flag &= ~MNT_RDONLY;
@@ -1457,7 +1457,7 @@ getdiskbyname(char *name) {
 	if (!bcmp(cp, "/dev/", 5))
 		cp += 5;
 
-	dev = NODEV;
+	dev = NULL;
 	EVENTHANDLER_INVOKE(dev_clone, cp, strlen(cp), &dev);
 	return (dev);
 }
@@ -1472,7 +1472,7 @@ setrootbyname(char *name)
 	struct cdev *diskdev;
 
 	diskdev = getdiskbyname(name);
-	if (diskdev != NODEV) {
+	if (diskdev != NULL) {
 		rootdev = diskdev;
 		return (0);
 	}
@@ -1491,7 +1491,7 @@ DB_SHOW_COMMAND(disk, db_getdiskbyname)
 		return;
 	}
 	dev = getdiskbyname(modif);
-	if (dev != NODEV)
+	if (dev != NULL)
 		db_printf("struct cdev *= %p\n", dev);
 	else
 		db_printf("No disk device matched.\n");
diff --git a/sys/kern/vfs_subr.c b/sys/kern/vfs_subr.c
index 0346fa2..96fdaab 100644
--- a/sys/kern/vfs_subr.c
+++ b/sys/kern/vfs_subr.c
@@ -367,7 +367,7 @@ vfs_getnewfsid(mp)
 	tfsid.val[1] = mtype;
 	mtype = (mtype & 0xFF) << 24;
 	for (;;) {
-		tfsid.val[0] = makeudev(255,
+		tfsid.val[0] = makedev(255,
 		    mtype | ((mntid_base & 0xFF00) << 8) | (mntid_base & 0xFF));
 		mntid_base++;
 		if (vfs_getvfs(&tfsid) == NULL)
@@ -1744,7 +1744,7 @@ bdevvp(dev, vpp)
 	struct vnode *nvp;
 	int error;
 
-	if (dev == NODEV) {
+	if (dev == NULL) {
 		*vpp = NULLVP;
 		return (ENXIO);
 	}
@@ -1786,7 +1786,7 @@ v_incr_usecount(struct vnode *vp, int delta)
 struct vnode *
 addaliasu(nvp, nvp_rdev)
 	struct vnode *nvp;
-	udev_t nvp_rdev;
+	dev_t nvp_rdev;
 {
 	struct vnode *ovp;
 	vop_t **ops;
@@ -1796,8 +1796,8 @@ addaliasu(nvp, nvp_rdev)
 		return (nvp);
 	if (nvp->v_type != VCHR)
 		panic("addaliasu on non-special vnode");
-	dev = udev2dev(nvp_rdev);
-	if (dev == NODEV)
+	dev = findcdev(nvp_rdev);
+	if (dev == NULL)
 		return (nvp);
 	/*
 	 * Check to see if we have a bdevvp vnode with no associated
@@ -1836,7 +1836,7 @@ addaliasu(nvp, nvp_rdev)
 }
 
 /* This is a local helper function that do the same as addaliasu, but for a
- * struct cdev *instead of an udev_t. */
+ * struct cdev *instead of an dev_t. */
 static void
 addalias(nvp, dev)
 	struct vnode *nvp;
@@ -2581,7 +2581,7 @@ vgonel(vp, td)
 	 * if it is on one.
 	 */
 	VI_LOCK(vp);
-	if (vp->v_type == VCHR && vp->v_rdev != NODEV) {
+	if (vp->v_type == VCHR && vp->v_rdev != NULL) {
 		mtx_lock(&spechash_mtx);
 		SLIST_REMOVE(&vp->v_rdev->si_hlist, vp, vnode, v_specnext);
 		vp->v_rdev->si_usecount -= vp->v_usecount;
@@ -3407,7 +3407,7 @@ vn_todev(vp)
 {
 
 	if (vp->v_type != VCHR)
-		return (NODEV);
+		return (NULL);
 	return (vp->v_rdev);
 }