Give vn_isdisk() a second argument where it can return a suitable errno.

Suggested by:	bde

26 files changed, 90 insertions, 79 deletions

diff --git a/sys/contrib/softupdates/ffs_softdep.c b/sys/contrib/softupdates/ffs_softdep.c
index 8f7e3f2..46495f3 100644
--- a/sys/contrib/softupdates/ffs_softdep.c
+++ b/sys/contrib/softupdates/ffs_softdep.c
@@ -3744,7 +3744,7 @@ softdep_fsync_mountdev(vp)
 	struct buf *bp, *nbp;
 	struct worklist *wk;
 
-	if (!vn_isdisk(vp))
+	if (!vn_isdisk(vp, NULL))
 		panic("softdep_fsync_mountdev: vnode not a disk");
 	ACQUIRE_LOCK(&lk);
 	for (bp = TAILQ_FIRST(&vp->v_dirtyblkhd); bp; bp = nbp) {
@@ -3806,7 +3806,7 @@ softdep_sync_metadata(ap)
 	 * Check whether this vnode is involved in a filesystem
 	 * that is doing soft dependency processing.
 	 */
-	if (!vn_isdisk(vp)) {
+	if (!vn_isdisk(vp, NULL)) {
 		if (!DOINGSOFTDEP(vp))
 			return (0);
 	} else
@@ -4031,7 +4031,8 @@ loop:
 	 * way to accomplish this is to sync the entire filesystem (luckily
 	 * this happens rarely).
 	 */
-	if (vn_isdisk(vp) && vp->v_specmountpoint && !VOP_ISLOCKED(vp, NULL) &&
+	if (vn_isdisk(vp, NULL) && 
+	    vp->v_specmountpoint && !VOP_ISLOCKED(vp, NULL) &&
 	    (error = VFS_SYNC(vp->v_specmountpoint, MNT_WAIT, ap->a_cred,
 	     ap->a_p)) != 0)
 		return (error);
diff --git a/sys/dev/ccd/ccd.c b/sys/dev/ccd/ccd.c
index 7109468..c2a960d 100644
--- a/sys/dev/ccd/ccd.c
+++ b/sys/dev/ccd/ccd.c
@@ -1603,10 +1603,8 @@ ccdlookup(path, p, vpp)
 		goto bad;
 	}
 
-	if (!vn_isdisk(vp)) {
-		error = ENOTBLK;
+	if (!vn_isdisk(vp, &error)) 
 		goto bad;
-	}
 
 #ifdef DEBUG
 	if (ccddebug & CCDB_VNODE)
diff --git a/sys/dev/vinum/vinumio.c b/sys/dev/vinum/vinumio.c
index 1dbc2cf..929ec01 100644
--- a/sys/dev/vinum/vinumio.c
+++ b/sys/dev/vinum/vinumio.c
@@ -77,16 +77,15 @@ open_drive(struct drive *drive, struct proc *p, int verbose)
 		drive->devicename,
 		drive->vp->v_usecount);
     }
-    if (!vn_isdisk(drive->vp)) {			    /* only consider disks */
-	NDFREE(&nd, NDF_ONLY_PNBUF);
+    if (!vn_isdisk(drive->vp, &drive->lasterror)) {	    /* only consider disks */
+    	NDFREE(&nd, NDF_ONLY_PNBUF);
 	VOP_UNLOCK(drive->vp, 0, drive->p);
 	close_drive(drive);
-	drive->lasterror = ENOTBLK;
 	if (verbose)
 	    log(LOG_WARNING,
 		"vinum open_drive %s: Not a block device\n",
 		drive->devicename);
-	return ENOTBLK;
+	return drive->lasterror;
     }
     drive->vp->v_numoutput = 0;
     VOP_UNLOCK(drive->vp, 0, drive->p);
diff --git a/sys/fs/cd9660/cd9660_vfsops.c b/sys/fs/cd9660/cd9660_vfsops.c
index 16d51e7..5a7e880 100644
--- a/sys/fs/cd9660/cd9660_vfsops.c
+++ b/sys/fs/cd9660/cd9660_vfsops.c
@@ -220,9 +220,9 @@ cd9660_mount(mp, path, data, ndp, p)
 		vrele(devvp);
 		return (ENXIO);
 	}
-	if (!vn_isdisk(devvp)) {
+	if (!vn_isdisk(devvp, &error)) {
 		vrele(devvp);
-		return (ENOTBLK);
+		return (error);
 	}
 
 	/*       
diff --git a/sys/fs/hpfs/hpfs_vfsops.c b/sys/fs/hpfs/hpfs_vfsops.c
index 1a7f85c..efbd013 100644
--- a/sys/fs/hpfs/hpfs_vfsops.c
+++ b/sys/fs/hpfs/hpfs_vfsops.c
@@ -238,10 +238,8 @@ hpfs_mount (
 	devvp = ndp->ni_vp;
 
 #if defined(__FreeBSD__)
-	if (!vn_isdisk(devvp)) {
-		err = ENOTBLK;
+	if (!vn_isdisk(devvp, &err)) 
 		goto error_2;
-	}
 #else /* defined(__NetBSD__) */
 	if (devvp->v_type != VBLK) {
 		err = ENOTBLK;
diff --git a/sys/fs/msdosfs/msdosfs_vfsops.c b/sys/fs/msdosfs/msdosfs_vfsops.c
index 13272af..94578e8 100644
--- a/sys/fs/msdosfs/msdosfs_vfsops.c
+++ b/sys/fs/msdosfs/msdosfs_vfsops.c
@@ -291,9 +291,9 @@ msdosfs_mount(mp, path, data, ndp, p)
 	devvp = ndp->ni_vp;
 	NDFREE(ndp, NDF_ONLY_PNBUF);
 
-	if (!vn_isdisk(devvp)) {
+	if (!vn_isdisk(devvp, &error)) {
 		vrele(devvp);
-		return (ENOTBLK);
+		return (error);
 	}
 	/*
 	 * If mount by non-root, then verify that user has necessary
diff --git a/sys/fs/ntfs/ntfs_vfsops.c b/sys/fs/ntfs/ntfs_vfsops.c
index d4883be..089c6eb 100644
--- a/sys/fs/ntfs/ntfs_vfsops.c
+++ b/sys/fs/ntfs/ntfs_vfsops.c
@@ -321,10 +321,8 @@ ntfs_mount (
 	devvp = ndp->ni_vp;
 
 #if defined(__FreeBSD__)
-	if (!vn_isdisk(devvp)) {
-		err = ENOTBLK;
+	if (!vn_isdisk(devvp, &err)) 
 		goto error_2;
-	}
 #else
 	if (devvp->v_type != VBLK) {
 		err = ENOTBLK;
diff --git a/sys/fs/specfs/spec_vnops.c b/sys/fs/specfs/spec_vnops.c
index 4f8488e..9641897 100644
--- a/sys/fs/specfs/spec_vnops.c
+++ b/sys/fs/specfs/spec_vnops.c
@@ -159,7 +159,8 @@ spec_open(ap)
 	 * XXX: take this into account, and consequently they need to
 	 * XXX: live in the diskslicing code.  Some checks do.
 	 */
-	if (vn_isdisk(vp) && ap->a_cred != FSCRED && (ap->a_mode & FWRITE)) {
+	if (vn_isdisk(vp, NULL) && ap->a_cred != FSCRED && 
+	    (ap->a_mode & FWRITE)) {
 		/*
 		 * Never allow opens for write if the device is mounted R/W
 		 */
@@ -204,7 +205,7 @@ spec_open(ap)
 		}
 	}
 
-	if (vn_isdisk(vp)) {
+	if (vn_isdisk(vp, NULL)) {
 		if (!dev->si_bsize_phys)
 			dev->si_bsize_phys = DEV_BSIZE;
 	}
@@ -337,7 +338,7 @@ spec_fsync(ap)
 	struct buf *nbp;
 	int s;
 
-	if (!vn_isdisk(vp))
+	if (!vn_isdisk(vp, NULL))
 		return (0);
 
 	/*
@@ -415,7 +416,7 @@ spec_strategy(ap)
 	 * and write counts for disks that have associated filesystems.
 	 */
 	vp = ap->a_vp;
-	if (vn_isdisk(vp) && (mp = vp->v_specmountpoint) != NULL) {
+	if (vn_isdisk(vp, NULL) && (mp = vp->v_specmountpoint) != NULL) {
 		if ((bp->b_flags & B_READ) == 0) {
 			if (bp->b_lock.lk_lockholder == LK_KERNPROC)
 				mp->mnt_stat.f_asyncwrites++;
@@ -640,7 +641,7 @@ spec_getpages(ap)
 	 * block device is mounted.  However, we can use v_rdev.
 	 */
 
-	if (vn_isdisk(vp))
+	if (vn_isdisk(vp, NULL))
 		blksiz = vp->v_rdev->si_bsize_phys;
 	else
 		blksiz = DEV_BSIZE;
diff --git a/sys/geom/geom_ccd.c b/sys/geom/geom_ccd.c
index 7109468..c2a960d 100644
--- a/sys/geom/geom_ccd.c
+++ b/sys/geom/geom_ccd.c
@@ -1603,10 +1603,8 @@ ccdlookup(path, p, vpp)
 		goto bad;
 	}
 
-	if (!vn_isdisk(vp)) {
-		error = ENOTBLK;
+	if (!vn_isdisk(vp, &error)) 
 		goto bad;
-	}
 
 #ifdef DEBUG
 	if (ccddebug & CCDB_VNODE)
diff --git a/sys/gnu/ext2fs/ext2_vfsops.c b/sys/gnu/ext2fs/ext2_vfsops.c
index 1865dbb..ac30793 100644
--- a/sys/gnu/ext2fs/ext2_vfsops.c
+++ b/sys/gnu/ext2fs/ext2_vfsops.c
@@ -268,9 +268,9 @@ ext2_mount(mp, path, data, ndp, p)
 	NDFREE(ndp, NDF_ONLY_PNBUF);
 	devvp = ndp->ni_vp;
 
-	if (!vn_isdisk(devvp)) {
+	if (!vn_isdisk(devvp, &error)) {
 		vrele(devvp);
-		return (ENOTBLK);
+		return (error);
 	}
 
 	/*
diff --git a/sys/gnu/fs/ext2fs/ext2_vfsops.c b/sys/gnu/fs/ext2fs/ext2_vfsops.c
index 1865dbb..ac30793 100644
--- a/sys/gnu/fs/ext2fs/ext2_vfsops.c
+++ b/sys/gnu/fs/ext2fs/ext2_vfsops.c
@@ -268,9 +268,9 @@ ext2_mount(mp, path, data, ndp, p)
 	NDFREE(ndp, NDF_ONLY_PNBUF);
 	devvp = ndp->ni_vp;
 
-	if (!vn_isdisk(devvp)) {
+	if (!vn_isdisk(devvp, &error)) {
 		vrele(devvp);
-		return (ENOTBLK);
+		return (error);
 	}
 
 	/*
diff --git a/sys/isofs/cd9660/cd9660_vfsops.c b/sys/isofs/cd9660/cd9660_vfsops.c
index 16d51e7..5a7e880 100644
--- a/sys/isofs/cd9660/cd9660_vfsops.c
+++ b/sys/isofs/cd9660/cd9660_vfsops.c
@@ -220,9 +220,9 @@ cd9660_mount(mp, path, data, ndp, p)
 		vrele(devvp);
 		return (ENXIO);
 	}
-	if (!vn_isdisk(devvp)) {
+	if (!vn_isdisk(devvp, &error)) {
 		vrele(devvp);
-		return (ENOTBLK);
+		return (error);
 	}
 
 	/*       
diff --git a/sys/kern/vfs_aio.c b/sys/kern/vfs_aio.c
index fd632a9..aba8a82 100644
--- a/sys/kern/vfs_aio.c
+++ b/sys/kern/vfs_aio.c
@@ -934,8 +934,8 @@ aio_qphysio(p, aiocbe)
 
 	vp = (struct vnode *)fp->f_data;
 
-	if (!vn_isdisk(vp))
-		return (-1);
+	if (!vn_isdisk(vp, &error))
+		return (error);
 
  	if (cb->aio_nbytes % vp->v_rdev->si_bsize_phys)
 		return (-1);
diff --git a/sys/kern/vfs_bio.c b/sys/kern/vfs_bio.c
index f12316b..2ef57c5 100644
--- a/sys/kern/vfs_bio.c
+++ b/sys/kern/vfs_bio.c
@@ -1016,7 +1016,7 @@ brelse(struct buf * bp)
 	 */
 	if ((bp->b_flags & B_VMIO)
 	    && !(bp->b_vp->v_tag == VT_NFS &&
-		 !vn_isdisk(bp->b_vp) &&
+		 !vn_isdisk(bp->b_vp, NULL) &&
 		 (bp->b_flags & B_DELWRI) &&
 		 (bp->b_xflags & BX_BKGRDINPROG))
 	    ) {
@@ -2230,7 +2230,7 @@ loop:
 		int bsize, maxsize, vmio;
 		off_t offset;
 
-		if (vn_isdisk(vp))
+		if (vn_isdisk(vp, NULL))
 			bsize = DEV_BSIZE;
 		else if (vp->v_mountedhere)
 			bsize = vp->v_mountedhere->mnt_stat.f_iosize;
@@ -2817,7 +2817,7 @@ biodone(register struct buf * bp)
 				    (int) m->pindex, (int)(foff >> 32),
 						(int) foff & 0xffffffff, resid, i);
 #endif
-				if (!vn_isdisk(vp))
+				if (!vn_isdisk(vp, NULL))
 #if !defined(MAX_PERF)
 					printf(" iosize: %ld, lblkno: %d, flags: 0x%lx, npages: %d\n",
 					    bp->b_vp->v_mount->mnt_stat.f_iosize,
diff --git a/sys/kern/vfs_export.c b/sys/kern/vfs_export.c
index 4e6123e..97d6251 100644
--- a/sys/kern/vfs_export.c
+++ b/sys/kern/vfs_export.c
@@ -1012,7 +1012,7 @@ sched_sync(void)
 				 * slot we are safe.
 				 */
 				if (TAILQ_EMPTY(&vp->v_dirtyblkhd) &&
-				    !vn_isdisk(vp))
+				    !vn_isdisk(vp, NULL))
 					panic("sched_sync: fsync failed vp %p tag %d", vp, vp->v_tag);
 				/*
 				 * Put us back on the worklist.  The worklist
@@ -2516,7 +2516,7 @@ vfs_object_create(vp, p, cred)
 	vm_object_t object;
 	int error = 0;
 
-	if (!vn_isdisk(vp) && vn_canvmio(vp) == FALSE)
+	if (!vn_isdisk(vp, NULL) && vn_canvmio(vp) == FALSE)
 		return 0;
 
 retry:
@@ -2875,15 +2875,27 @@ vn_todev(vp)
  * Check if vnode represents a disk device
  */
 int
-vn_isdisk(vp)
+vn_isdisk(vp, errp)
 	struct vnode *vp;
+	int *errp;
 {
-	if (vp->v_type != VBLK && vp->v_type != VCHR)
+	if (vp->v_type != VBLK && vp->v_type != VCHR) {
+		if (errp != NULL)
+			*errp = ENOTBLK;
 		return (0);
-	if (!devsw(vp->v_rdev))
+	}
+	if (!devsw(vp->v_rdev)) {
+		if (errp != NULL)
+			*errp = ENXIO;
 		return (0);
-	if (!(devsw(vp->v_rdev)->d_flags & D_DISK))
+	}
+	if (!(devsw(vp->v_rdev)->d_flags & D_DISK)) {
+		if (errp != NULL)
+			*errp = ENOTBLK;
 		return (0);
+	}
+	if (errp != NULL)
+		*errp = 0;
 	return (1);
 }
 
diff --git a/sys/kern/vfs_subr.c b/sys/kern/vfs_subr.c
index 4e6123e..97d6251 100644
--- a/sys/kern/vfs_subr.c
+++ b/sys/kern/vfs_subr.c
@@ -1012,7 +1012,7 @@ sched_sync(void)
 				 * slot we are safe.
 				 */
 				if (TAILQ_EMPTY(&vp->v_dirtyblkhd) &&
-				    !vn_isdisk(vp))
+				    !vn_isdisk(vp, NULL))
 					panic("sched_sync: fsync failed vp %p tag %d", vp, vp->v_tag);
 				/*
 				 * Put us back on the worklist.  The worklist
@@ -2516,7 +2516,7 @@ vfs_object_create(vp, p, cred)
 	vm_object_t object;
 	int error = 0;
 
-	if (!vn_isdisk(vp) && vn_canvmio(vp) == FALSE)
+	if (!vn_isdisk(vp, NULL) && vn_canvmio(vp) == FALSE)
 		return 0;
 
 retry:
@@ -2875,15 +2875,27 @@ vn_todev(vp)
  * Check if vnode represents a disk device
  */
 int
-vn_isdisk(vp)
+vn_isdisk(vp, errp)
 	struct vnode *vp;
+	int *errp;
 {
-	if (vp->v_type != VBLK && vp->v_type != VCHR)
+	if (vp->v_type != VBLK && vp->v_type != VCHR) {
+		if (errp != NULL)
+			*errp = ENOTBLK;
 		return (0);
-	if (!devsw(vp->v_rdev))
+	}
+	if (!devsw(vp->v_rdev)) {
+		if (errp != NULL)
+			*errp = ENXIO;
 		return (0);
-	if (!(devsw(vp->v_rdev)->d_flags & D_DISK))
+	}
+	if (!(devsw(vp->v_rdev)->d_flags & D_DISK)) {
+		if (errp != NULL)
+			*errp = ENOTBLK;
 		return (0);
+	}
+	if (errp != NULL)
+		*errp = 0;
 	return (1);
 }
 
diff --git a/sys/kern/vfs_vnops.c b/sys/kern/vfs_vnops.c
index edbf7b1..bb390ae 100644
--- a/sys/kern/vfs_vnops.c
+++ b/sys/kern/vfs_vnops.c
@@ -473,9 +473,7 @@ vn_stat(vp, sb, p)
 
 	if (vap->va_type == VREG) {
 		sb->st_blksize = vap->va_blocksize;
-	} else if ((vp->v_type == VBLK || vp->v_type == VCHR) &&
-	    devsw(vp->v_rdev) && (devsw(vp->v_rdev)->d_flags & D_DISK)) {
-		/* XXX use vn_isdisk() above once VCHR is also disk */
+	} else if (vn_isdisk(vp, NULL)) {
 		sb->st_blksize = vp->v_rdev->si_bsize_best;
 		if (sb->st_blksize < vp->v_rdev->si_bsize_phys)
 			sb->st_blksize = vp->v_rdev->si_bsize_phys;
diff --git a/sys/miscfs/devfs/devfs_vnops.c b/sys/miscfs/devfs/devfs_vnops.c
index 4d1c8bd..51315c7 100644
--- a/sys/miscfs/devfs/devfs_vnops.c
+++ b/sys/miscfs/devfs/devfs_vnops.c
@@ -1316,7 +1316,7 @@ devfs_open( struct vop_open_args *ap)
 		if ( (dsw == NULL) || (dsw->d_open == NULL))
 			return ENXIO;
 		if (ap->a_cred != FSCRED && (ap->a_mode & FWRITE) && 
-		    vn_isdisk(vp)) {
+		    vn_isdisk(vp, NULL)) {
 			/*
 			 * When running in very secure mode, do not allow
 			 * opens for writing of any disk devices.
diff --git a/sys/miscfs/specfs/spec_vnops.c b/sys/miscfs/specfs/spec_vnops.c
index 4f8488e..9641897 100644
--- a/sys/miscfs/specfs/spec_vnops.c
+++ b/sys/miscfs/specfs/spec_vnops.c
@@ -159,7 +159,8 @@ spec_open(ap)
 	 * XXX: take this into account, and consequently they need to
 	 * XXX: live in the diskslicing code.  Some checks do.
 	 */
-	if (vn_isdisk(vp) && ap->a_cred != FSCRED && (ap->a_mode & FWRITE)) {
+	if (vn_isdisk(vp, NULL) && ap->a_cred != FSCRED && 
+	    (ap->a_mode & FWRITE)) {
 		/*
 		 * Never allow opens for write if the device is mounted R/W
 		 */
@@ -204,7 +205,7 @@ spec_open(ap)
 		}
 	}
 
-	if (vn_isdisk(vp)) {
+	if (vn_isdisk(vp, NULL)) {
 		if (!dev->si_bsize_phys)
 			dev->si_bsize_phys = DEV_BSIZE;
 	}
@@ -337,7 +338,7 @@ spec_fsync(ap)
 	struct buf *nbp;
 	int s;
 
-	if (!vn_isdisk(vp))
+	if (!vn_isdisk(vp, NULL))
 		return (0);
 
 	/*
@@ -415,7 +416,7 @@ spec_strategy(ap)
 	 * and write counts for disks that have associated filesystems.
 	 */
 	vp = ap->a_vp;
-	if (vn_isdisk(vp) && (mp = vp->v_specmountpoint) != NULL) {
+	if (vn_isdisk(vp, NULL) && (mp = vp->v_specmountpoint) != NULL) {
 		if ((bp->b_flags & B_READ) == 0) {
 			if (bp->b_lock.lk_lockholder == LK_KERNPROC)
 				mp->mnt_stat.f_asyncwrites++;
@@ -640,7 +641,7 @@ spec_getpages(ap)
 	 * block device is mounted.  However, we can use v_rdev.
 	 */
 
-	if (vn_isdisk(vp))
+	if (vn_isdisk(vp, NULL))
 		blksiz = vp->v_rdev->si_bsize_phys;
 	else
 		blksiz = DEV_BSIZE;
diff --git a/sys/msdosfs/msdosfs_vfsops.c b/sys/msdosfs/msdosfs_vfsops.c
index 13272af..94578e8 100644
--- a/sys/msdosfs/msdosfs_vfsops.c
+++ b/sys/msdosfs/msdosfs_vfsops.c
@@ -291,9 +291,9 @@ msdosfs_mount(mp, path, data, ndp, p)
 	devvp = ndp->ni_vp;
 	NDFREE(ndp, NDF_ONLY_PNBUF);
 
-	if (!vn_isdisk(devvp)) {
+	if (!vn_isdisk(devvp, &error)) {
 		vrele(devvp);
-		return (ENOTBLK);
+		return (error);
 	}
 	/*
 	 * If mount by non-root, then verify that user has necessary
diff --git a/sys/ntfs/ntfs_vfsops.c b/sys/ntfs/ntfs_vfsops.c
index d4883be..089c6eb 100644
--- a/sys/ntfs/ntfs_vfsops.c
+++ b/sys/ntfs/ntfs_vfsops.c
@@ -321,10 +321,8 @@ ntfs_mount (
 	devvp = ndp->ni_vp;
 
 #if defined(__FreeBSD__)
-	if (!vn_isdisk(devvp)) {
-		err = ENOTBLK;
+	if (!vn_isdisk(devvp, &err)) 
 		goto error_2;
-	}
 #else
 	if (devvp->v_type != VBLK) {
 		err = ENOTBLK;
diff --git a/sys/sys/vnode.h b/sys/sys/vnode.h
index e37035a..376a21c 100644
--- a/sys/sys/vnode.h
+++ b/sys/sys/vnode.h
@@ -569,7 +569,7 @@ int	vrecycle __P((struct vnode *vp, struct simplelock *inter_lkp,
 	    struct proc *p));
 int 	vn_close __P((struct vnode *vp,
 	    int flags, struct ucred *cred, struct proc *p));
-int	vn_isdisk __P((struct vnode *vp));
+int	vn_isdisk __P((struct vnode *vp, int *errp));
 int	vn_lock __P((struct vnode *vp, int flags, struct proc *p));
 #ifdef	DEBUG_LOCKS
 int	debug_vn_lock __P((struct vnode *vp, int flags, struct proc *p,
diff --git a/sys/ufs/ffs/ffs_softdep.c b/sys/ufs/ffs/ffs_softdep.c
index 8f7e3f2..46495f3 100644
--- a/sys/ufs/ffs/ffs_softdep.c
+++ b/sys/ufs/ffs/ffs_softdep.c
@@ -3744,7 +3744,7 @@ softdep_fsync_mountdev(vp)
 	struct buf *bp, *nbp;
 	struct worklist *wk;
 
-	if (!vn_isdisk(vp))
+	if (!vn_isdisk(vp, NULL))
 		panic("softdep_fsync_mountdev: vnode not a disk");
 	ACQUIRE_LOCK(&lk);
 	for (bp = TAILQ_FIRST(&vp->v_dirtyblkhd); bp; bp = nbp) {
@@ -3806,7 +3806,7 @@ softdep_sync_metadata(ap)
 	 * Check whether this vnode is involved in a filesystem
 	 * that is doing soft dependency processing.
 	 */
-	if (!vn_isdisk(vp)) {
+	if (!vn_isdisk(vp, NULL)) {
 		if (!DOINGSOFTDEP(vp))
 			return (0);
 	} else
@@ -4031,7 +4031,8 @@ loop:
 	 * way to accomplish this is to sync the entire filesystem (luckily
 	 * this happens rarely).
 	 */
-	if (vn_isdisk(vp) && vp->v_specmountpoint && !VOP_ISLOCKED(vp, NULL) &&
+	if (vn_isdisk(vp, NULL) && 
+	    vp->v_specmountpoint && !VOP_ISLOCKED(vp, NULL) &&
 	    (error = VFS_SYNC(vp->v_specmountpoint, MNT_WAIT, ap->a_cred,
 	     ap->a_p)) != 0)
 		return (error);
diff --git a/sys/ufs/ffs/ffs_vfsops.c b/sys/ufs/ffs/ffs_vfsops.c
index 77e821f..511c827 100644
--- a/sys/ufs/ffs/ffs_vfsops.c
+++ b/sys/ufs/ffs/ffs_vfsops.c
@@ -280,10 +280,8 @@ ffs_mount( mp, path, data, ndp, p)
 	NDFREE(ndp, NDF_ONLY_PNBUF);
 	devvp = ndp->ni_vp;
 
-	if (!vn_isdisk(devvp)) {
-		err = ENOTBLK;
+	if (!vn_isdisk(devvp, &err))
 		goto error_2;
-	}
 
 	/*
 	 * If mount by non-root, then verify that user has necessary
@@ -442,7 +440,7 @@ ffs_reload(mp, cred, p)
 	 * Only VMIO the backing device if the backing device is a real
 	 * block device.  See ffs_mountmfs() for more details.
 	 */
-	if (devvp->v_tag != VT_MFS && vn_isdisk(devvp)) {
+	if (devvp->v_tag != VT_MFS && vn_isdisk(devvp, NULL)) {
 		vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY, p);
 		vfs_object_create(devvp, p, p->p_ucred);
 		simple_lock(&devvp->v_interlock);
@@ -599,7 +597,7 @@ ffs_mountfs(devvp, mp, p, malloctype)
 	 * Note that it is optional that the backing device be VMIOed.  This
 	 * increases the opportunity for metadata caching.
 	 */
-	if (devvp->v_tag != VT_MFS && vn_isdisk(devvp)) {
+	if (devvp->v_tag != VT_MFS && vn_isdisk(devvp, NULL)) {
 		vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY, p);
 		vfs_object_create(devvp, p, p->p_ucred);
 		simple_lock(&devvp->v_interlock);
diff --git a/sys/ufs/ffs/ffs_vnops.c b/sys/ufs/ffs/ffs_vnops.c
index 6087d81..5a7ce0b 100644
--- a/sys/ufs/ffs/ffs_vnops.c
+++ b/sys/ufs/ffs/ffs_vnops.c
@@ -126,9 +126,8 @@ ffs_fsync(ap)
 	int s, error, wait, passes, skipmeta;
 	daddr_t lbn;
 
-
 	wait = (ap->a_waitfor == MNT_WAIT);
-	if (vn_isdisk(vp)) {
+	if (vn_isdisk(vp, NULL)) {
 		lbn = INT_MAX;
 		if (vp->v_specmountpoint != NULL &&
 		    (vp->v_specmountpoint->mnt_flag & MNT_SOFTDEP))
@@ -265,7 +264,7 @@ loop:
 				goto loop;
 			}
 #ifdef DIAGNOSTIC
-			if (!vn_isdisk(vp))
+			if (!vn_isdisk(vp, NULL))
 				vprint("ffs_fsync: dirty", vp);
 #endif
 		}
diff --git a/sys/vm/vm_swap.c b/sys/vm/vm_swap.c
index 23bddad..9577c59 100644
--- a/sys/vm/vm_swap.c
+++ b/sys/vm/vm_swap.c
@@ -202,8 +202,7 @@ swapon(p, uap)
 	NDFREE(&nd, NDF_ONLY_PNBUF);
 	vp = nd.ni_vp;
 
-	if (!vn_isdisk(vp)) 
-		error = ENOTBLK;
+	vn_isdisk(vp, &error);
 
 	if (!error)
 		error = swaponvp(p, vp, vp->v_rdev, 0);