Make bdev userland access work like cdev userland access unless

the highly non-recommended option ALLOW_BDEV_ACCESS is used.

(bdev access is evil because you don't get write errors reported.)

Kill si_bsize_best before it kills Matt :-)

Use the specfs routines rather having cloned copies in devfs.

17 files changed, 78 insertions, 254 deletions

diff --git a/sys/conf/NOTES b/sys/conf/NOTES
index 544b2f4..1bc4df6 100644
--- a/sys/conf/NOTES
+++ b/sys/conf/NOTES
@@ -625,6 +625,9 @@ pseudo-device	vcoda	4		#coda minicache <-> venus comm.
 #
 options 	EXT2FS
 
+#
+# Only set this if you positively know why you should never do that.
+options		ALLOW_BDEV_ACCESS
 
 
 #####################################################################
diff --git a/sys/conf/options b/sys/conf/options
index ba04359..2146ffe 100644
--- a/sys/conf/options
+++ b/sys/conf/options
@@ -126,6 +126,9 @@ CD9660_ROOTDELAY	opt_cd9660.h
 # hidden yet.
 UNION
 
+# Options for all filesystems
+ALLOW_BDEV_ACCESS	opt_fs.h
+
 # Options used only in param.c.
 HZ		opt_param.h
 MAXFILES	opt_param.h
diff --git a/sys/dev/ccd/ccd.c b/sys/dev/ccd/ccd.c
index 7badacb..c4a0a8e 100644
--- a/sys/dev/ccd/ccd.c
+++ b/sys/dev/ccd/ccd.c
@@ -634,7 +634,6 @@ ccdopen(dev, flags, fmt, p)
 	pmask = (1 << part);
 
 	dev->si_bsize_phys = DEV_BSIZE;
-	dev->si_bsize_best = BLKDEV_IOSIZE;
 	dev->si_bsize_max = MAXBSIZE;
 
 	/*
diff --git a/sys/dev/fdc/fdc.c b/sys/dev/fdc/fdc.c
index 7704cca..539569d 100644
--- a/sys/dev/fdc/fdc.c
+++ b/sys/dev/fdc/fdc.c
@@ -1227,7 +1227,6 @@ Fdopen(dev_t dev, int flags, int mode, struct proc *p)
 	fdc_p	fdc;
 
 	dev->si_bsize_phys = DEV_BSIZE;
-	dev->si_bsize_best = BLKDEV_IOSIZE;
 	dev->si_bsize_max = MAXBSIZE;
 	/* check bounds */
 	if ((fd = devclass_get_softc(fd_devclass, fdu)) == 0)
diff --git a/sys/dev/vinum/vinum.c b/sys/dev/vinum/vinum.c
index 29b7232..2355544 100644
--- a/sys/dev/vinum/vinum.c
+++ b/sys/dev/vinum/vinum.c
@@ -272,7 +272,6 @@ vinumopen(dev_t dev,
 
     devminor = minor(dev);
     dev->si_bsize_phys = DEV_BSIZE;
-    dev->si_bsize_best = VINUM_BSIZE_BEST;		    /* kludge until we track drive block sizes */
     dev->si_bsize_max = MAXBSIZE;
     error = 0;
     /* First, decide what we're looking at */
diff --git a/sys/fs/specfs/spec_vnops.c b/sys/fs/specfs/spec_vnops.c
index 1afc400..e097ef8 100644
--- a/sys/fs/specfs/spec_vnops.c
+++ b/sys/fs/specfs/spec_vnops.c
@@ -34,6 +34,7 @@
  * $FreeBSD$
  */
 
+#include "opt_fs.h"
 #include <sys/param.h>
 #include <sys/proc.h>
 #include <sys/systm.h>
@@ -258,6 +259,8 @@ spec_read(ap)
 	int error = 0;
 	dev_t dev;
 
+	dev = vp->v_rdev;
+
 #ifdef DIAGNOSTIC
 	if (uio->uio_rw != UIO_READ)
 		panic("spec_read mode");
@@ -269,24 +272,14 @@ spec_read(ap)
 
 	switch (vp->v_type) {
 
-	case VCHR:
-		VOP_UNLOCK(vp, 0, p);
-		error = (*devsw(vp->v_rdev)->d_read)
-			(vp->v_rdev, uio, ap->a_ioflag);
-		vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
-		return (error);
-
 	case VBLK:
+#ifdef ALLOW_BDEV_ACCESS
 		if (uio->uio_offset < 0)
 			return (EINVAL);
-		dev = vp->v_rdev;
-
-		/*
-		 * Calculate block size for block device.  The block size must
-		 * be larger then the physical minimum.
-		 */
 
-		bsize = vp->v_rdev->si_bsize_best;
+		bsize = dev->si_bsize_phys;
+		while (bsize < dev->si_bsize_max && bsize < uio->uio_resid)
+			bsize <<= 1;
 
 		if ((ioctl = devsw(dev)->d_ioctl) != NULL &&
 		    (*ioctl)(dev, DIOCGPART, (caddr_t)&dpart, FREAD, p) == 0 &&
@@ -314,6 +307,12 @@ spec_read(ap)
 			brelse(bp);
 		} while (error == 0 && uio->uio_resid > 0 && n != 0);
 		return (error);
+#endif /* ALLOW_BDEV_ACCESS */
+	case VCHR:
+		VOP_UNLOCK(vp, 0, p);
+		error = (*devsw(dev)->d_read) (dev, uio, ap->a_ioflag);
+		vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
+		return (error);
 
 	default:
 		panic("spec_read type");
@@ -343,36 +342,30 @@ spec_write(ap)
 	struct partinfo dpart;
 	register int n, on;
 	int error = 0;
+	dev_t dev;
 
+	dev = vp->v_rdev;
 #ifdef DIAGNOSTIC
 	if (uio->uio_rw != UIO_WRITE)
 		panic("spec_write mode");
 	if (uio->uio_segflg == UIO_USERSPACE && uio->uio_procp != curproc)
 		panic("spec_write proc");
 #endif
+	if (uio->uio_resid == 0)
+		return (0);
 
 	switch (vp->v_type) {
 
-	case VCHR:
-		VOP_UNLOCK(vp, 0, p);
-		error = (*devsw(vp->v_rdev)->d_write)
-			(vp->v_rdev, uio, ap->a_ioflag);
-		vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
-		return (error);
-
 	case VBLK:
-		if (uio->uio_resid == 0)
-			return (0);
+#ifdef ALLOW_BDEV_ACCESS
 		if (uio->uio_offset < 0)
 			return (EINVAL);
 
-		/*
-		 * Calculate block size for block device.  The block size must
-		 * be larger then the physical minimum.
-		 */
-		bsize = vp->v_rdev->si_bsize_best;
+		bsize = dev->si_bsize_phys;
+		while (bsize < dev->si_bsize_max && bsize < uio->uio_resid)
+			bsize <<= 1;
 
-		if ((*devsw(vp->v_rdev)->d_ioctl)(vp->v_rdev, DIOCGPART,
+		if ((*devsw(dev)->d_ioctl)(dev, DIOCGPART,
 		    (caddr_t)&dpart, FREAD, p) == 0) {
 			if (dpart.part->p_fstype == FS_BSDFFS &&
 			    dpart.part->p_frag != 0 && dpart.part->p_fsize != 0)
@@ -400,6 +393,14 @@ spec_write(ap)
 				bdwrite(bp);
 		} while (error == 0 && uio->uio_resid > 0 && n != 0);
 		return (error);
+#endif /* ALLOW_BDEV_ACCESS */
+
+	case VCHR:
+		VOP_UNLOCK(vp, 0, p);
+		error = (*devsw(dev)->d_write)
+			(dev, uio, ap->a_ioflag);
+		vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
+		return (error);
 
 	default:
 		panic("spec_write type");
diff --git a/sys/geom/geom_ccd.c b/sys/geom/geom_ccd.c
index 7badacb..c4a0a8e 100644
--- a/sys/geom/geom_ccd.c
+++ b/sys/geom/geom_ccd.c
@@ -634,7 +634,6 @@ ccdopen(dev, flags, fmt, p)
 	pmask = (1 << part);
 
 	dev->si_bsize_phys = DEV_BSIZE;
-	dev->si_bsize_best = BLKDEV_IOSIZE;
 	dev->si_bsize_max = MAXBSIZE;
 
 	/*
diff --git a/sys/i386/conf/LINT b/sys/i386/conf/LINT
index 544b2f4..1bc4df6 100644
--- a/sys/i386/conf/LINT
+++ b/sys/i386/conf/LINT
@@ -625,6 +625,9 @@ pseudo-device	vcoda	4		#coda minicache <-> venus comm.
 #
 options 	EXT2FS
 
+#
+# Only set this if you positively know why you should never do that.
+options		ALLOW_BDEV_ACCESS
 
 
 #####################################################################
diff --git a/sys/i386/conf/NOTES b/sys/i386/conf/NOTES
index 544b2f4..1bc4df6 100644
--- a/sys/i386/conf/NOTES
+++ b/sys/i386/conf/NOTES
@@ -625,6 +625,9 @@ pseudo-device	vcoda	4		#coda minicache <-> venus comm.
 #
 options 	EXT2FS
 
+#
+# Only set this if you positively know why you should never do that.
+options		ALLOW_BDEV_ACCESS
 
 
 #####################################################################
diff --git a/sys/isa/fd.c b/sys/isa/fd.c
index 7704cca..539569d 100644
--- a/sys/isa/fd.c
+++ b/sys/isa/fd.c
@@ -1227,7 +1227,6 @@ Fdopen(dev_t dev, int flags, int mode, struct proc *p)
 	fdc_p	fdc;
 
 	dev->si_bsize_phys = DEV_BSIZE;
-	dev->si_bsize_best = BLKDEV_IOSIZE;
 	dev->si_bsize_max = MAXBSIZE;
 	/* check bounds */
 	if ((fd = devclass_get_softc(fd_devclass, fdu)) == 0)
diff --git a/sys/kern/subr_diskslice.c b/sys/kern/subr_diskslice.c
index ae676e3..e2b35ef 100644
--- a/sys/kern/subr_diskslice.c
+++ b/sys/kern/subr_diskslice.c
@@ -710,7 +710,6 @@ dsopen(dev, mode, flags, sspp, lp)
 	int	unit;
 
 	dev->si_bsize_phys = lp->d_secsize;
-	dev->si_bsize_best = BLKDEV_IOSIZE;
 	dev->si_bsize_max = MAXBSIZE;
 
 	unit = dkunit(dev);
diff --git a/sys/kern/vfs_vnops.c b/sys/kern/vfs_vnops.c
index 0a08938..e1459d1 100644
--- a/sys/kern/vfs_vnops.c
+++ b/sys/kern/vfs_vnops.c
@@ -436,8 +436,6 @@ vn_stat(vp, sb, p)
 	 */
 	switch (vap->va_type) {
 	case VBLK:
-		sb->st_blksize = vp->v_rdev->si_bsize_best;
-		break;
 	case VCHR:
 		sb->st_blksize = vp->v_rdev->si_bsize_max;
 		break;
diff --git a/sys/miscfs/devfs/devfs_vnops.c b/sys/miscfs/devfs/devfs_vnops.c
index 9d6ce13..ea63d3a 100644
--- a/sys/miscfs/devfs/devfs_vnops.c
+++ b/sys/miscfs/devfs/devfs_vnops.c
@@ -26,7 +26,6 @@
  * $FreeBSD$
  */
 
-
 #include <sys/param.h>
 #include <sys/systm.h>
 #include <sys/buf.h>
@@ -651,7 +650,7 @@ devfs_xwrite(struct vop_write_args *ap)
 	case VBLK:
 		panic("devfs:  vnode methods");
 	default:
-		panic("devfs_write(): bad file type");
+		panic("devfs_xwrite(): bad file type");
 	}
 }
 
@@ -1412,199 +1411,24 @@ devfs_open( struct vop_open_args *ap)
 	return (error);
 }
 
-/*
- * Vnode op for read
-	struct vop_read_args {
-		struct vnode *a_vp;
-		struct uio *a_uio;
-		int  a_ioflag;
-		struct ucred *a_cred;
-	} 
- */
 /* ARGSUSED */
 static int
 devfs_read( struct vop_read_args *ap)
 {
-	struct vnode *vp = ap->a_vp;
-	struct uio *uio = ap->a_uio;
- 	struct proc *p = uio->uio_procp;
-	struct buf *bp;
-	daddr_t bn, nextbn;
-	long bsize, bscale;
-	struct partinfo dpart;
-	int n, on;
-	d_ioctl_t *ioctl;
-	int error = 0;
-	dev_t dev;
-	dn_p	dnp;
-
-	if ((error = devfs_vntodn(vp,&dnp)) != 0)
-		return error;
-
-
-#ifdef DIAGNOSTIC
-	if (uio->uio_rw != UIO_READ)
-		panic("devfs_read mode");
-	if (uio->uio_segflg == UIO_USERSPACE && uio->uio_procp != curproc)
-		panic("devfs_read proc");
-#endif
-	if (uio->uio_resid == 0)
-		return (0);
-
-	switch (vp->v_type) {
-
-	case VCHR:
-		VOP_UNLOCK(vp, 0, p);
-		error = (*vp->v_rdev->si_devsw->d_read)
-			(vp->v_rdev, uio, ap->a_ioflag);
-		vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
-		break;
-
-	case VBLK:
-		if (uio->uio_offset < 0)
-			return (EINVAL);
-		/*
-		 * Calculate block size for block device.  The block size must
-		 * be larger then the physical minimum.
-		 */
+	int error;
 
-		dev = vp->v_rdev;
-		bsize = dev->si_bsize_best;
-		/*
-		 * This is a hack!
-		 */
-		if ( (ioctl = dev->si_devsw->d_ioctl) != NULL &&
-		    (*ioctl)(dev, DIOCGPART, (caddr_t)&dpart, FREAD, p) == 0 &&
-		    dpart.part->p_fstype == FS_BSDFFS &&
-		    dpart.part->p_frag != 0 && dpart.part->p_fsize != 0)
-			bsize = dpart.part->p_frag * dpart.part->p_fsize;
-		bscale = btodb(bsize);
-		/* 
-		 * Get buffers with this data from the buffer cache.
-		 * If it's not there the strategy() entrypoint will be called.
-		 * We may do this in several chunks.
-		 */
-		do {
-			bn = btodb(uio->uio_offset) & ~(bscale - 1);
-			on = uio->uio_offset % bsize;
-			n = min((unsigned)(bsize - on), uio->uio_resid);
-			if (vp->v_lastr + bscale == bn) {
-				nextbn = bn + bscale;
-				error = breadn(vp, bn, (int)bsize, &nextbn,
-					(int *)&bsize, 1, NOCRED, &bp);
-			} else
-				error = bread(vp, bn, (int)bsize, NOCRED, &bp);
-			vp->v_lastr = bn;
-			n = min(n, bsize - bp->b_resid);
-			if (error) {
-				brelse(bp);
-				return (error);
-			}
-			/* 
-			 * Copy it to the user's space
-			 */
-			error = uiomove((char *)bp->b_data + on, n, uio);
-			brelse(bp);
-		} while (error == 0 && uio->uio_resid > 0 && n != 0);
-		break;
-	default:
-		panic("devfs_read type");
-	}
-	if (!(vp->v_mount->mnt_flag & MNT_NOATIME))
-		dnp->flags |= IN_ACCESS;        
+        error = VOCALL(spec_vnodeop_p, VOFFSET(vop_read), ap);
 	return (error);
 }
 
-/*
- * Vnode op for write
-	struct vop_write_args  {
-		struct vnode *a_vp;
-		struct uio *a_uio;
-		int  a_ioflag;
-		struct ucred *a_cred;
-	}
- */
 /* ARGSUSED */
 static int
 devfs_write( struct vop_write_args *ap)
 {
-	struct vnode *vp = ap->a_vp;
-	struct uio *uio = ap->a_uio;
-	struct proc *p = uio->uio_procp;
-	struct buf *bp;
-	daddr_t bn;
-	int bsize, blkmask;
-	struct partinfo dpart;
-	int n, on;
-	int error = 0;
-	dn_p	dnp;
-
-	if ((error = devfs_vntodn(vp,&dnp)) != 0)
-		return error;
-
-
-#ifdef DIAGNOSTIC
-	if (uio->uio_rw != UIO_WRITE)
-		panic("devfs_write mode");
-	if (uio->uio_segflg == UIO_USERSPACE && uio->uio_procp != curproc)
-		panic("devfs_write proc");
-#endif
-
-	switch (vp->v_type) {
-
-	case VCHR:
-		VOP_UNLOCK(vp, 0, p);
-		error = (*vp->v_rdev->si_devsw->d_write)
-			(vp->v_rdev, uio, ap->a_ioflag);
-		vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
-		return (error);
-
-	case VBLK:
-		if (uio->uio_resid == 0)
-			return (0);
-		if (uio->uio_offset < 0)
-			return (EINVAL);
-
-		/*
-		 * Calculate block size for block device.  The block size must
-		 * be larger then the physical minimum.
-		 */
-		bsize = vp->v_rdev->si_bsize_best;
-
-		if ((vp->v_rdev->si_devsw->d_ioctl != NULL)
-		&& ((*vp->v_rdev->si_devsw->d_ioctl)(vp->v_rdev, DIOCGPART,
-					(caddr_t)&dpart, FREAD, p) == 0)
-		&& (dpart.part->p_fstype == FS_BSDFFS)
-		&& (dpart.part->p_frag != 0)
-		&& (dpart.part->p_fsize != 0)) {
-			bsize = dpart.part->p_frag * dpart.part->p_fsize;
-		}
-		blkmask = btodb(bsize) - 1;
-		do {
-			bn = btodb(uio->uio_offset) & ~blkmask;
-			on = uio->uio_offset % bsize;
-			n = min((unsigned)(bsize - on), uio->uio_resid);
-			if (n == bsize)
-				bp = getblk(vp, bn, bsize, 0, 0);
-			else
-				error = bread(vp, bn, bsize, NOCRED, &bp);
-			if (error) {
-				brelse(bp);
-				return (error);
-			}
-			n = min(n, bsize - bp->b_resid);
-			error = uiomove((char *)bp->b_data + on, n, uio);
-			if (n + on == bsize)
-				bawrite(bp);
-			else
-				bdwrite(bp);
-		} while (error == 0 && uio->uio_resid > 0 && n != 0);
-		return (error);
+	int error;
 
-	default:
-		panic("devfs_write type");
-	}
-	/* NOTREACHED */
+	error = VOCALL(spec_vnodeop_p, VOFFSET(vop_write), ap);
+	return (error);
 }
 
 /*
diff --git a/sys/miscfs/specfs/spec_vnops.c b/sys/miscfs/specfs/spec_vnops.c
index 1afc400..e097ef8 100644
--- a/sys/miscfs/specfs/spec_vnops.c
+++ b/sys/miscfs/specfs/spec_vnops.c
@@ -34,6 +34,7 @@
  * $FreeBSD$
  */
 
+#include "opt_fs.h"
 #include <sys/param.h>
 #include <sys/proc.h>
 #include <sys/systm.h>
@@ -258,6 +259,8 @@ spec_read(ap)
 	int error = 0;
 	dev_t dev;
 
+	dev = vp->v_rdev;
+
 #ifdef DIAGNOSTIC
 	if (uio->uio_rw != UIO_READ)
 		panic("spec_read mode");
@@ -269,24 +272,14 @@ spec_read(ap)
 
 	switch (vp->v_type) {
 
-	case VCHR:
-		VOP_UNLOCK(vp, 0, p);
-		error = (*devsw(vp->v_rdev)->d_read)
-			(vp->v_rdev, uio, ap->a_ioflag);
-		vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
-		return (error);
-
 	case VBLK:
+#ifdef ALLOW_BDEV_ACCESS
 		if (uio->uio_offset < 0)
 			return (EINVAL);
-		dev = vp->v_rdev;
-
-		/*
-		 * Calculate block size for block device.  The block size must
-		 * be larger then the physical minimum.
-		 */
 
-		bsize = vp->v_rdev->si_bsize_best;
+		bsize = dev->si_bsize_phys;
+		while (bsize < dev->si_bsize_max && bsize < uio->uio_resid)
+			bsize <<= 1;
 
 		if ((ioctl = devsw(dev)->d_ioctl) != NULL &&
 		    (*ioctl)(dev, DIOCGPART, (caddr_t)&dpart, FREAD, p) == 0 &&
@@ -314,6 +307,12 @@ spec_read(ap)
 			brelse(bp);
 		} while (error == 0 && uio->uio_resid > 0 && n != 0);
 		return (error);
+#endif /* ALLOW_BDEV_ACCESS */
+	case VCHR:
+		VOP_UNLOCK(vp, 0, p);
+		error = (*devsw(dev)->d_read) (dev, uio, ap->a_ioflag);
+		vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
+		return (error);
 
 	default:
 		panic("spec_read type");
@@ -343,36 +342,30 @@ spec_write(ap)
 	struct partinfo dpart;
 	register int n, on;
 	int error = 0;
+	dev_t dev;
 
+	dev = vp->v_rdev;
 #ifdef DIAGNOSTIC
 	if (uio->uio_rw != UIO_WRITE)
 		panic("spec_write mode");
 	if (uio->uio_segflg == UIO_USERSPACE && uio->uio_procp != curproc)
 		panic("spec_write proc");
 #endif
+	if (uio->uio_resid == 0)
+		return (0);
 
 	switch (vp->v_type) {
 
-	case VCHR:
-		VOP_UNLOCK(vp, 0, p);
-		error = (*devsw(vp->v_rdev)->d_write)
-			(vp->v_rdev, uio, ap->a_ioflag);
-		vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
-		return (error);
-
 	case VBLK:
-		if (uio->uio_resid == 0)
-			return (0);
+#ifdef ALLOW_BDEV_ACCESS
 		if (uio->uio_offset < 0)
 			return (EINVAL);
 
-		/*
-		 * Calculate block size for block device.  The block size must
-		 * be larger then the physical minimum.
-		 */
-		bsize = vp->v_rdev->si_bsize_best;
+		bsize = dev->si_bsize_phys;
+		while (bsize < dev->si_bsize_max && bsize < uio->uio_resid)
+			bsize <<= 1;
 
-		if ((*devsw(vp->v_rdev)->d_ioctl)(vp->v_rdev, DIOCGPART,
+		if ((*devsw(dev)->d_ioctl)(dev, DIOCGPART,
 		    (caddr_t)&dpart, FREAD, p) == 0) {
 			if (dpart.part->p_fstype == FS_BSDFFS &&
 			    dpart.part->p_frag != 0 && dpart.part->p_fsize != 0)
@@ -400,6 +393,14 @@ spec_write(ap)
 				bdwrite(bp);
 		} while (error == 0 && uio->uio_resid > 0 && n != 0);
 		return (error);
+#endif /* ALLOW_BDEV_ACCESS */
+
+	case VCHR:
+		VOP_UNLOCK(vp, 0, p);
+		error = (*devsw(dev)->d_write)
+			(dev, uio, ap->a_ioflag);
+		vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
+		return (error);
 
 	default:
 		panic("spec_write type");
diff --git a/sys/sys/conf.h b/sys/sys/conf.h
index e63e0b9..b1a713b 100644
--- a/sys/sys/conf.h
+++ b/sys/sys/conf.h
@@ -69,7 +69,6 @@ struct specinfo {
 			struct disk *__sid_disk;
 			struct mount *__sid_mountpoint;
 			int __sid_bsize_phys; /* min physical block size */
-			int __sid_bsize_best; /* optimal block size */
 			int __sid_bsize_max;  /* maximum block size */
 		} __si_disk;
 	} __si_u;
@@ -79,7 +78,6 @@ struct specinfo {
 #define si_disk	__si_u.__si_disk.__sid_disk
 #define si_mountpoint	__si_u.__si_disk.__sid_mountpoint
 #define si_bsize_phys	__si_u.__si_disk.__sid_bsize_phys
-#define si_bsize_best	__si_u.__si_disk.__sid_bsize_best
 #define si_bsize_max	__si_u.__si_disk.__sid_bsize_max
 
 /*
diff --git a/sys/sys/linedisc.h b/sys/sys/linedisc.h
index e63e0b9..b1a713b 100644
--- a/sys/sys/linedisc.h
+++ b/sys/sys/linedisc.h
@@ -69,7 +69,6 @@ struct specinfo {
 			struct disk *__sid_disk;
 			struct mount *__sid_mountpoint;
 			int __sid_bsize_phys; /* min physical block size */
-			int __sid_bsize_best; /* optimal block size */
 			int __sid_bsize_max;  /* maximum block size */
 		} __si_disk;
 	} __si_u;
@@ -79,7 +78,6 @@ struct specinfo {
 #define si_disk	__si_u.__si_disk.__sid_disk
 #define si_mountpoint	__si_u.__si_disk.__sid_mountpoint
 #define si_bsize_phys	__si_u.__si_disk.__sid_bsize_phys
-#define si_bsize_best	__si_u.__si_disk.__sid_bsize_best
 #define si_bsize_max	__si_u.__si_disk.__sid_bsize_max
 
 /*
diff --git a/sys/ufs/mfs/mfs_vfsops.c b/sys/ufs/mfs/mfs_vfsops.c
index 044bf63..4f8c9f6 100644
--- a/sys/ufs/mfs/mfs_vfsops.c
+++ b/sys/ufs/mfs/mfs_vfsops.c
@@ -333,7 +333,6 @@ mfs_mount(mp, path, data, ndp, p)
 	devvp->v_type = VBLK;
 	dev = make_dev(&mfs_cdevsw, mfs_minor, 0, 0, 0, "MFS%d", mfs_minor);
 	dev->si_bsize_phys = DEV_BSIZE;
-	dev->si_bsize_best = BLKDEV_IOSIZE;
 	dev->si_bsize_max = MAXBSIZE;
 	addaliasu(devvp, makeudev(253, mfs_minor++));
 	devvp->v_data = mfsp;
@@ -495,7 +494,6 @@ mfs_init(vfsp)
 		rootdev = make_dev(&mfs_cdevsw, mfs_minor, 
 		    0, 0, 0, "MFS%d", mfs_minor);
 		rootdev->si_bsize_phys = DEV_BSIZE;
-		rootdev->si_bsize_best = BLKDEV_IOSIZE;
 		rootdev->si_bsize_max = MAXBSIZE;
 		mfs_minor++;
 	} else if (bootverbose)