/*
 * Copyright (c) 2007 The DragonFly Project.  All rights reserved.
 *
 * This code is derived from software contributed to The DragonFly Project
 * by Matthew Dillon <dillon@backplane.com>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 3. Neither the name of The DragonFly Project nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific, prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 */
/*
 * Copyright (c) 1995 Jason R. Thorpe.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed for the NetBSD Project
 *	by Jason R. Thorpe.
 * 4. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/*
 * Copyright (c) 1988 University of Utah.
 * Copyright (c) 1990, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * the Systems Programming Group of the University of Utah Computer
 * Science Department.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * from: Utah $Hdr: cd.c 1.6 90/11/28$
 */
/*
 * @(#)cd.c	8.2 (Berkeley) 11/16/93
 * $FreeBSD: src/sys/dev/ccd/ccd.c,v 1.73.2.1 2001/09/11 09:49:52 kris Exp $
 * $NetBSD: ccd.c,v 1.22 1995/12/08 19:13:26 thorpej Exp $
 */

/*
 * "Concatenated" disk driver.
 *
 * Original dynamic configuration support by:
 *	Jason R. Thorpe <thorpej@nas.nasa.gov>
 *	Numerical Aerodynamic Simulation Facility
 *	Mail Stop 258-6
 *	NASA Ames Research Center
 *	Moffett Field, CA 94035
 */

#include "use_ccd.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/proc.h>
#include <sys/buf.h>
#include <sys/malloc.h>
#include <sys/nlookup.h>
#include <sys/conf.h>
#include <sys/stat.h>
#include <sys/sysctl.h>
#include <sys/disk.h>
#include <sys/dtype.h>
#include <sys/diskslice.h>
#include <sys/devicestat.h>
#include <sys/fcntl.h>
#include <sys/vnode.h>
#include <sys/ccdvar.h>

#include <vm/vm_zone.h>

#include <vfs/ufs/dinode.h> 	/* XXX Used only for fs.h */
#include <vfs/ufs/fs.h> 	/* XXX used only to get BBSIZE and SBSIZE */

#include <sys/buf2.h>

#if defined(CCDDEBUG) && !defined(DEBUG)
#define DEBUG
#endif

#ifdef DEBUG
#define CCDB_FOLLOW	0x01
#define CCDB_INIT	0x02
#define CCDB_IO		0x04
#define CCDB_LABEL	0x08
#define CCDB_VNODE	0x10
static int ccddebug = CCDB_FOLLOW | CCDB_INIT | CCDB_IO | CCDB_LABEL |
    CCDB_VNODE;
SYSCTL_INT(_debug, OID_AUTO, ccddebug, CTLFLAG_RW, &ccddebug, 0, "");
#undef DEBUG
#endif

#define	ccdunit(x)	dkunit(x)
#define ccdpart(x)	dkpart(x)

/*
   This is how mirroring works (only writes are special):

   When initiating a write, ccdbuffer() returns two "struct ccdbuf *"s
   linked together by the cb_mirror field.  "cb_pflags &
   CCDPF_MIRROR_DONE" is set to 0 on both of them.

   When a component returns to ccdiodone(), it checks if "cb_pflags &
   CCDPF_MIRROR_DONE" is set or not.  If not, it sets the partner's
   flag and returns.  If it is, it means its partner has already
   returned, so it will go to the regular cleanup.

 */

struct ccdbuf {
	struct buf	cb_buf;		/* new I/O buf */
	struct vnode	*cb_vp;		/* related vnode */
	struct bio	*cb_obio;	/* ptr. to original I/O buf */
	int		cb_unit;	/* target unit */
	int		cb_comp;	/* target component */
	int		cb_pflags;	/* mirror/parity status flag */
	struct ccdbuf	*cb_mirror;	/* mirror counterpart */
};

/* bits in cb_pflags */
#define CCDPF_MIRROR_DONE 1	/* if set, mirror counterpart is done */

static d_open_t ccdopen;
static d_close_t ccdclose;
static d_strategy_t ccdstrategy;
static d_ioctl_t ccdioctl;
static d_dump_t ccddump;

static struct dev_ops ccd_ops = {
	{ "ccd", 0, D_DISK | D_MPSAFE },
	.d_open =	ccdopen,
	.d_close =	ccdclose,
	.d_read =	physread,
	.d_write =	physwrite,
	.d_ioctl =	ccdioctl,
	.d_strategy =	ccdstrategy,
	.d_dump =	ccddump
};

/* called during module initialization */
static	void ccdattach (void);
static	int ccddetach (void);
static	int ccd_modevent (module_t, int, void *);

/* called by biodone() at interrupt time */
static	void ccdiodone (struct bio *bio);

static	void ccdstart (struct ccd_softc *, struct bio *);
static	void ccdinterleave (struct ccd_softc *, int);
static	void ccdintr (struct ccd_softc *, struct bio *);
static	int ccdinit (struct ccddevice *, char **, struct ucred *);
static	int ccdlookup (char *, struct vnode **);
static	void ccdbuffer (struct ccdbuf **ret, struct ccd_softc *,
		struct bio *, off_t, caddr_t, long);
static	int ccdlock (struct ccd_softc *);
static	void ccdunlock (struct ccd_softc *);

#ifdef DEBUG
static	void printiinfo (struct ccdiinfo *);
#endif

/* Non-private for the benefit of libkvm. */
struct	ccd_softc *ccd_softc;
struct	ccddevice *ccddevs;
static	int numccd = 0;

/*
 * getccdbuf() -	Allocate and zero a ccd buffer.
 */
static struct ccdbuf *
getccdbuf(void)
{
	struct ccdbuf *cbp;

	cbp = kmalloc(sizeof(struct ccdbuf), M_DEVBUF, M_WAITOK | M_ZERO);
	initbufbio(&cbp->cb_buf);

	/*
	 * independant struct buf initialization
	 */
	buf_dep_init(&cbp->cb_buf);
	BUF_LOCK(&cbp->cb_buf, LK_EXCLUSIVE);
	BUF_KERNPROC(&cbp->cb_buf);
	cbp->cb_buf.b_flags = B_PAGING | B_BNOCLIP;

	return(cbp);
}

/*
 * putccdbuf() -	Free a ccd buffer.
 */
static void
putccdbuf(struct ccdbuf *cbp)
{
	BUF_UNLOCK(&cbp->cb_buf);

	uninitbufbio(&cbp->cb_buf);
	kfree(cbp, M_DEVBUF);
}

/*
 * Called by main() during pseudo-device attachment.  All we need
 * to do is allocate enough space for devices to be configured later, and
 * add devsw entries.
 */
static void
ccdattach(void)
{
	struct disk_info info;
	struct ccd_softc *cs;
	int i;
	int num = NCCD;

	if (num > 1)
		kprintf("ccd0-%d: Concatenated disk drivers\n", num-1);
	else
		kprintf("ccd0: Concatenated disk driver\n");

	ccd_softc = kmalloc(num * sizeof(struct ccd_softc), M_DEVBUF,
			    M_WAITOK | M_ZERO);
	ccddevs = kmalloc(num * sizeof(struct ccddevice), M_DEVBUF,
			  M_WAITOK | M_ZERO);
	numccd = num;

	/*
	 * With normal disk devices the open simply fails if the media
	 * is not present.  With CCD we have to be able to open the
	 * raw disk to use the ioctl's to set it up, so create a dummy
	 * disk info structure so dscheck() doesn't blow up.
	 */
	bzero(&info, sizeof(info));
	info.d_media_blksize = DEV_BSIZE;

	for (i = 0; i < numccd; ++i) {
		cs = &ccd_softc[i];
		cs->sc_dev = disk_create(i, &cs->sc_disk, &ccd_ops);
		cs->sc_dev->si_drv1 = cs;
		cs->sc_dev->si_iosize_max = 256 * 512;	/* XXX */
		disk_setdiskinfo(&cs->sc_disk, &info);
	}
}

static int
ccddetach(void)
{
	struct ccd_softc *cs;
	struct dev_ioctl_args ioctl_args;
	int i;
	int error = 0;
	int eval;

	bzero(&ioctl_args, sizeof(ioctl_args));

	for (i = 0; i < numccd; ++i) {
		cs = &ccd_softc[i];
		if (cs->sc_dev == NULL)
			continue;
		ioctl_args.a_head.a_dev = cs->sc_dev;
		ioctl_args.a_cmd = CCDIOCCLR;
		ioctl_args.a_fflag = FWRITE;
		eval = ccdioctl(&ioctl_args);
		if (eval && eval != ENXIO) {
			kprintf("ccd%d: In use, cannot detach\n", i);
			error = EBUSY;
		}
	}
	if (error == 0) {
		for (i = 0; i < numccd; ++i) {
			cs = &ccd_softc[i];
			if (cs->sc_dev == NULL)
				continue;
			disk_destroy(&cs->sc_disk);
			cs->sc_dev = NULL;
		}
		if (ccd_softc)
			kfree(ccd_softc, M_DEVBUF);
		if (ccddevs)
			kfree(ccddevs, M_DEVBUF);
	}
	return (error);
}

static int
ccd_modevent(module_t mod, int type, void *data)
{
	int error = 0;

	switch (type) {
	case MOD_LOAD:
		ccdattach();
		break;

	case MOD_UNLOAD:
		error = ccddetach();
		break;

	default:	/* MOD_SHUTDOWN etc */
		break;
	}
	return (error);
}

DEV_MODULE(ccd, ccd_modevent, NULL);

static int
ccdinit(struct ccddevice *ccd, char **cpaths, struct ucred *cred)
{
	struct ccd_softc *cs = &ccd_softc[ccd->ccd_unit];
	struct ccdcinfo *ci = NULL;	/* XXX */
	int ix;
	struct vnode *vp;
	u_int64_t skip;
	u_int64_t size;
	u_int64_t minsize;
	int maxsecsize;
	struct partinfo dpart;
	struct ccdgeom *ccg = &cs->sc_geom;
	char tmppath[MAXPATHLEN];
	int error = 0;

#ifdef DEBUG
	if (ccddebug & (CCDB_FOLLOW|CCDB_INIT))
		kprintf("ccdinit: unit %d\n", ccd->ccd_unit);
#endif

	cs->sc_size = 0;
	cs->sc_ileave = ccd->ccd_interleave;
	cs->sc_nccdisks = ccd->ccd_ndev;

	/* Allocate space for the component info. */
	cs->sc_cinfo = kmalloc(cs->sc_nccdisks * sizeof(struct ccdcinfo),
				M_DEVBUF, M_WAITOK);
	cs->sc_maxiosize = MAXPHYS;

	lockinit(&cs->sc_lock, "ccdlck", 0, 0);
	ccdlock(cs);

	/*
	 * Verify that each component piece exists and record
	 * relevant information about it.
	 */
	maxsecsize = 0;
	minsize = 0;
	for (ix = 0; ix < cs->sc_nccdisks; ix++) {
		vp = ccd->ccd_vpp[ix];
		ci = &cs->sc_cinfo[ix];
		ci->ci_vp = vp;

		/*
		 * Copy in the pathname of the component.
		 */
		bzero(tmppath, sizeof(tmppath));	/* sanity */
		if ((error = copyinstr(cpaths[ix], tmppath,
		    MAXPATHLEN, &ci->ci_pathlen)) != 0) {
#ifdef DEBUG
			if (ccddebug & (CCDB_FOLLOW|CCDB_INIT))
				kprintf("ccd%d: can't copy path, error = %d\n",
				    ccd->ccd_unit, error);
#endif
			goto fail;
		}
		ci->ci_path = kmalloc(ci->ci_pathlen, M_DEVBUF, M_WAITOK);
		bcopy(tmppath, ci->ci_path, ci->ci_pathlen);

		ci->ci_dev = vn_todev(vp);
		if (ci->ci_dev->si_iosize_max &&
		    cs->sc_maxiosize > ci->ci_dev->si_iosize_max) {
			cs->sc_maxiosize = ci->ci_dev->si_iosize_max;
		}

		/*
		 * Get partition information for the component.
		 */
		error = VOP_IOCTL(vp, DIOCGPART, (caddr_t)&dpart, FREAD,
				  cred, NULL);
		if (error) {
#ifdef DEBUG
			if (ccddebug & (CCDB_FOLLOW|CCDB_INIT))
				 kprintf("ccd%d: %s: ioctl failed, error = %d\n",
				     ccd->ccd_unit, ci->ci_path, error);
#endif
			goto fail;
		}
		if (dpart.fstype != FS_CCD &&
		    !kuuid_is_ccd(&dpart.fstype_uuid)) {
			kprintf("ccd%d: %s: filesystem type must be 'ccd'\n",
				ccd->ccd_unit, ci->ci_path);
			error = EFTYPE;
			goto fail;
		}
		if (maxsecsize < dpart.media_blksize)
			maxsecsize = dpart.media_blksize;

		/*
		 * Skip a certain amount of storage at the beginning of
		 * the component to make sure we don't infringe on any
		 * reserved sectors.  This is handled entirely by
		 * dpart.reserved_blocks but we also impose a minimum
		 * of 16 sectors for backwards compatibility.
		 */
		skip = 16;
		if (skip < dpart.reserved_blocks)
			skip = dpart.reserved_blocks;
		size = dpart.media_blocks - skip;

		/*
		 * Calculate the size, truncating to an interleave
		 * boundary if necessary.
		 */
		if (cs->sc_ileave > 1)
			size -= size % cs->sc_ileave;

		if ((int64_t)size <= 0) {
#ifdef DEBUG
			if (ccddebug & (CCDB_FOLLOW|CCDB_INIT))
				kprintf("ccd%d: %s: size == 0\n",
				    ccd->ccd_unit, ci->ci_path);
#endif
			error = ENODEV;
			goto fail;
		}

		/*
		 * Calculate the smallest uniform component, used
		 * elsewhere.
		 */
		if (minsize == 0 || minsize > size)
			minsize = size;
		ci->ci_skip = skip;
		ci->ci_size = size;
		cs->sc_size += size;
	}
	kprintf("ccd%d: max component iosize is %d total blocks %lld\n",
		cs->sc_unit, cs->sc_maxiosize, (long long)cs->sc_size);

	/*
	 * Don't allow the interleave to be smaller than
	 * the biggest component sector.
	 */
	if ((cs->sc_ileave > 0) &&
	    (cs->sc_ileave % (maxsecsize / DEV_BSIZE))) {
#ifdef DEBUG
		if (ccddebug & (CCDB_FOLLOW|CCDB_INIT))
			kprintf("ccd%d: interleave must be at least %d\n",
			    ccd->ccd_unit, (maxsecsize / DEV_BSIZE));
#endif
		error = EINVAL;
		goto fail;
	}

	/*
	 * If uniform interleave is desired set all sizes to that of
	 * the smallest component.  This will guarentee that a single
	 * interleave table is generated.
	 *
	 * Lost space must be taken into account when calculating the
	 * overall size.  Half the space is lost when CCDF_MIRROR is
	 * specified.  One disk is lost when CCDF_PARITY is specified.
	 */
	if (ccd->ccd_flags & CCDF_UNIFORM) {
		for (ci = cs->sc_cinfo;
		     ci < &cs->sc_cinfo[cs->sc_nccdisks]; ci++) {
			ci->ci_size = minsize;
		}
		if (ccd->ccd_flags & CCDF_MIRROR) {
			/*
			 * Check to see if an even number of components
			 * have been specified.  The interleave must also
			 * be non-zero in order for us to be able to
			 * guarentee the topology.
			 */
			if (cs->sc_nccdisks % 2) {
				kprintf("ccd%d: mirroring requires an even number of disks\n", ccd->ccd_unit );
				error = EINVAL;
				goto fail;
			}
			if (cs->sc_ileave == 0) {
				kprintf("ccd%d: an interleave must be specified when mirroring\n", ccd->ccd_unit);
				error = EINVAL;
				goto fail;
			}
			cs->sc_size = (cs->sc_nccdisks/2) * minsize;
		} else if (ccd->ccd_flags & CCDF_PARITY) {
			cs->sc_size = (cs->sc_nccdisks-1) * minsize;
		} else {
			if (cs->sc_ileave == 0) {
				kprintf("ccd%d: an interleave must be specified when using parity\n", ccd->ccd_unit);
				error = EINVAL;
				goto fail;
			}
			cs->sc_size = cs->sc_nccdisks * minsize;
		}
	}

	/*
	 * Construct the interleave table.
	 */
	ccdinterleave(cs, ccd->ccd_unit);

	/*
	 * Create pseudo-geometry based on 1MB cylinders.  It's
	 * pretty close.
	 */
	ccg->ccg_secsize = maxsecsize;
	ccg->ccg_ntracks = 1;
	ccg->ccg_nsectors = 1024 * 1024 / ccg->ccg_secsize;
	ccg->ccg_ncylinders = cs->sc_size / ccg->ccg_nsectors;

	/*
	 * Add an devstat entry for this device.
	 */
	devstat_add_entry(&cs->device_stats, "ccd", ccd->ccd_unit,
			  ccg->ccg_secsize, DEVSTAT_ALL_SUPPORTED,
			  DEVSTAT_TYPE_STORARRAY |DEVSTAT_TYPE_IF_OTHER,
			  DEVSTAT_PRIORITY_ARRAY);

	cs->sc_flags |= CCDF_INITED;
	cs->sc_cflags = ccd->ccd_flags;	/* So we can find out later... */
	cs->sc_unit = ccd->ccd_unit;
	return (0);
fail:
	while (ci > cs->sc_cinfo) {
		ci--;
		kfree(ci->ci_path, M_DEVBUF);
	}
	kfree(cs->sc_cinfo, M_DEVBUF);
	cs->sc_cinfo = NULL;
	return (error);
}

static void
ccdinterleave(struct ccd_softc *cs, int unit)
{
	struct ccdcinfo *ci, *smallci;
	struct ccdiinfo *ii;
	u_int64_t bn;
	u_int64_t lbn;
	u_int64_t size;
	int icount;
	int ix;

#ifdef DEBUG
	if (ccddebug & CCDB_INIT)
		kprintf("ccdinterleave(%x): ileave %d\n", cs, cs->sc_ileave);
#endif

	/*
	 * Allocate an interleave table.  The worst case occurs when each
	 * of N disks is of a different size, resulting in N interleave
	 * tables.
	 *
	 * Chances are this is too big, but we don't care.
	 */
	icount = cs->sc_nccdisks + 1;
	cs->sc_itable = kmalloc(icount * sizeof(struct ccdiinfo),
				M_DEVBUF, M_WAITOK|M_ZERO);

	/*
	 * Trivial case: no interleave (actually interleave of disk size).
	 * Each table entry represents a single component in its entirety.
	 *
	 * An interleave of 0 may not be used with a mirror or parity setup.
	 */
	if (cs->sc_ileave == 0) {
		bn = 0;
		ii = cs->sc_itable;

		for (ix = 0; ix < cs->sc_nccdisks; ix++) {
			/* Allocate space for ii_index. */
			ii->ii_index = kmalloc(sizeof(int), M_DEVBUF, M_WAITOK);
			ii->ii_ndisk = 1;
			ii->ii_startblk = bn;
			ii->ii_startoff = 0;
			ii->ii_index[0] = ix;
			bn += cs->sc_cinfo[ix].ci_size;
			ii++;
		}
		ii->ii_ndisk = 0;
#ifdef DEBUG
		if (ccddebug & CCDB_INIT)
			printiinfo(cs->sc_itable);
#endif
		return;
	}

	/*
	 * The following isn't fast or pretty; it doesn't have to be.
	 */
	size = 0;
	bn = lbn = 0;
	for (ii = cs->sc_itable; ii < &cs->sc_itable[icount]; ++ii) {
		/*
		 * Allocate space for ii_index.  We might allocate more then
		 * we use.
		 */
		ii->ii_index = kmalloc((sizeof(int) * cs->sc_nccdisks),
					M_DEVBUF, M_WAITOK);

		/*
		 * Locate the smallest of the remaining components
		 */
		smallci = NULL;
		ci = cs->sc_cinfo;
		while (ci < &cs->sc_cinfo[cs->sc_nccdisks]) {
			if (ci->ci_size > size &&
			    (smallci == NULL ||
			     ci->ci_size < smallci->ci_size)) {
				smallci = ci;
			}
			++ci;
		}

		/*
		 * Nobody left, all done
		 */
		if (smallci == NULL) {
			ii->ii_ndisk = 0;
			break;
		}

		/*
		 * Record starting logical block using an sc_ileave blocksize.
		 */
		ii->ii_startblk = bn / cs->sc_ileave;

		/*
		 * Record starting component block using an sc_ileave
		 * blocksize.  This value is relative to the beginning of
		 * a component disk.
		 */
		ii->ii_startoff = lbn;

		/*
		 * Determine how many disks take part in this interleave
		 * and record their indices.
		 */
		ix = 0;
		for (ci = cs->sc_cinfo;
		    ci < &cs->sc_cinfo[cs->sc_nccdisks]; ci++) {
			if (ci->ci_size >= smallci->ci_size) {
				ii->ii_index[ix++] = ci - cs->sc_cinfo;
			}
		}
		ii->ii_ndisk = ix;

		/*
		 * Adjust for loop
		 */
		bn += ix * (smallci->ci_size - size);
		lbn = smallci->ci_size / cs->sc_ileave;
		size = smallci->ci_size;
	}
	if (ii == &cs->sc_itable[icount])
		panic("ccdinterlave software bug!  table exhausted");
#ifdef DEBUG
	if (ccddebug & CCDB_INIT)
		printiinfo(cs->sc_itable);
#endif
}

/* ARGSUSED */
static int
ccdopen(struct dev_open_args *ap)
{
	cdev_t dev = ap->a_head.a_dev;
	int unit = ccdunit(dev);
	struct ccd_softc *cs;
	int error = 0;

#ifdef DEBUG
	if (ccddebug & CCDB_FOLLOW)
		kprintf("ccdopen(%x, %x)\n", dev, flags);
#endif
	if (unit >= numccd)
		return (ENXIO);
	cs = &ccd_softc[unit];

	if ((error = ccdlock(cs)) == 0) {
		ccdunlock(cs);
	}
	return (error);
}

/* ARGSUSED */
static int
ccdclose(struct dev_close_args *ap)
{
	cdev_t dev = ap->a_head.a_dev;
	int unit = ccdunit(dev);
	struct ccd_softc *cs;
	int error = 0;

#ifdef DEBUG
	if (ccddebug & CCDB_FOLLOW)
		kprintf("ccdclose(%x, %x)\n", dev, flags);
#endif

	if (unit >= numccd)
		return (ENXIO);
	cs = &ccd_softc[unit];
	if ((error = ccdlock(cs)) == 0) {
		ccdunlock(cs);
	}
	return (error);
}

static int
ccdstrategy(struct dev_strategy_args *ap)
{
	cdev_t dev = ap->a_head.a_dev;
	struct bio *bio = ap->a_bio;
	int unit = ccdunit(dev);
	struct bio *nbio;
	struct buf *bp = bio->bio_buf;
	struct ccd_softc *cs = &ccd_softc[unit];
	u_int64_t pbn;	/* in sc_secsize chunks */
	u_int32_t sz;	/* in sc_secsize chunks */

#ifdef DEBUG
	if (ccddebug & CCDB_FOLLOW)
		kprintf("ccdstrategy(%x): unit %d\n", bp, unit);
#endif
	if ((cs->sc_flags & CCDF_INITED) == 0) {
		bp->b_error = ENXIO;
		goto error;
	}

	/* If it's a nil transfer, wake up the top half now. */
	if (bp->b_bcount == 0) {
		bp->b_resid = 0;
		goto done;
	}

	/*
	 * Do bounds checking and adjust transfer.  If there's an
	 * error, the bounds check will flag that for us.
	 */

	pbn = bio->bio_offset / cs->sc_geom.ccg_secsize;
	sz = howmany(bp->b_bcount, cs->sc_geom.ccg_secsize);

	/*
	 * If out of bounds return an error.  If the request goes
	 * past EOF, clip the request as appropriate.  If exactly
	 * at EOF, return success (don't clip), but with 0 bytes
	 * of I/O.
	 *
	 * Mark EOF B_INVAL (just like bad), indicating that the
	 * contents of the buffer, if any, is invalid.
	 */
	if ((int64_t)pbn < 0)
		goto bad;
	if (pbn + sz > cs->sc_size) {
		if (pbn > cs->sc_size || (bp->b_flags & B_BNOCLIP))
			goto bad;
		if (pbn == cs->sc_size) {
			bp->b_resid = bp->b_bcount;
			bp->b_flags |= B_INVAL;
			goto done;
		}
		sz = (long)(cs->sc_size - pbn);
		bp->b_bcount = sz * cs->sc_geom.ccg_secsize;
	}
	nbio = bio;

	bp->b_resid = bp->b_bcount;
	nbio->bio_driver_info = dev;

	/*
	 * "Start" the unit.
	 */
	ccdstart(cs, nbio);
	return(0);

	/*
	 * note: bio, not nbio, is valid at the done label.
	 */
bad:
	bp->b_error = EINVAL;
error:
	bp->b_resid = bp->b_bcount;
	bp->b_flags |= B_ERROR | B_INVAL;
done:
	biodone(bio);
	return(0);
}

static void
ccdstart(struct ccd_softc *cs, struct bio *bio)
{
	long bcount, rcount;
	struct ccdbuf *cbp[4];
	struct buf *bp = bio->bio_buf;
	/* XXX! : 2 reads and 2 writes for RAID 4/5 */
	caddr_t addr;
	off_t doffset;

#ifdef DEBUG
	if (ccddebug & CCDB_FOLLOW)
		kprintf("ccdstart(%x, %x)\n", cs, bp);
#endif

	/* Record the transaction start  */
	devstat_start_transaction(&cs->device_stats);

	/*
	 * Allocate component buffers and fire off the requests
	 */
	doffset = bio->bio_offset;
	addr = bp->b_data;

	for (bcount = bp->b_bcount; bcount > 0; bcount -= rcount) {
		ccdbuffer(cbp, cs, bio, doffset, addr, bcount);
		rcount = cbp[0]->cb_buf.b_bcount;

		if (cs->sc_cflags & CCDF_MIRROR) {
			/*
			 * Mirroring.  Writes go to both disks, reads are
			 * taken from whichever disk seems most appropriate.
			 *
			 * We attempt to localize reads to the disk whos arm
			 * is nearest the read request.  We ignore seeks due
			 * to writes when making this determination and we
			 * also try to avoid hogging.
			 */
			if (cbp[0]->cb_buf.b_cmd != BUF_CMD_READ) {
				vn_strategy(cbp[0]->cb_vp,
					    &cbp[0]->cb_buf.b_bio1);
				vn_strategy(cbp[1]->cb_vp,
					    &cbp[1]->cb_buf.b_bio1);
			} else {
				int pick = cs->sc_pick;
				daddr_t range = cs->sc_size / 16 * cs->sc_geom.ccg_secsize;
				if (doffset < cs->sc_blk[pick] - range ||
				    doffset > cs->sc_blk[pick] + range
				) {
					cs->sc_pick = pick = 1 - pick;
				}
				cs->sc_blk[pick] = doffset + rcount;
				vn_strategy(cbp[pick]->cb_vp,
					    &cbp[pick]->cb_buf.b_bio1);
			}
		} else {
			/*
			 * Not mirroring
			 */
			vn_strategy(cbp[0]->cb_vp,
				     &cbp[0]->cb_buf.b_bio1);
		}
		doffset += rcount;
		addr += rcount;
	}
}

/*
 * Build a component buffer header.
 */
static void
ccdbuffer(struct ccdbuf **cb, struct ccd_softc *cs, struct bio *bio,
	  off_t doffset, caddr_t addr, long bcount)
{
	struct ccdcinfo *ci, *ci2 = NULL;	/* XXX */
	struct ccdbuf *cbp;
	u_int64_t bn;
	u_int64_t cbn;
	u_int64_t cboff;
	off_t cbc;

#ifdef DEBUG
	if (ccddebug & CCDB_IO)
		kprintf("ccdbuffer(%x, %x, %d, %x, %d)\n",
		       cs, bp, bn, addr, bcount);
#endif
	/*
	 * Determine which component bn falls in.
	 */
	bn = doffset / cs->sc_geom.ccg_secsize;
	cbn = bn;
	cboff = 0;

	if (cs->sc_ileave == 0) {
		/*
		 * Serially concatenated and neither a mirror nor a parity
		 * config.  This is a special case.
		 */
		daddr_t sblk;

		sblk = 0;
		for (ci = cs->sc_cinfo; cbn >= sblk + ci->ci_size; ci++)
			sblk += ci->ci_size;
		cbn -= sblk;
	} else {
		struct ccdiinfo *ii;
		int ccdisk, off;

		/*
		 * Calculate cbn, the logical superblock (sc_ileave chunks),
		 * and cboff, a normal block offset (DEV_BSIZE chunks) relative
		 * to cbn.
		 */
		cboff = cbn % cs->sc_ileave;	/* DEV_BSIZE gran */
		cbn = cbn / cs->sc_ileave;	/* DEV_BSIZE * ileave gran */

		/*
		 * Figure out which interleave table to use.
		 */
		for (ii = cs->sc_itable; ii->ii_ndisk; ii++) {
			if (ii->ii_startblk > cbn)
				break;
		}
		ii--;

		/*
		 * off is the logical superblock relative to the beginning
		 * of this interleave block.
		 */
		off = cbn - ii->ii_startblk;

		/*
		 * We must calculate which disk component to use (ccdisk),
		 * and recalculate cbn to be the superblock relative to
		 * the beginning of the component.  This is typically done by
		 * adding 'off' and ii->ii_startoff together.  However, 'off'
		 * must typically be divided by the number of components in
		 * this interleave array to be properly convert it from a
		 * CCD-relative logical superblock number to a
		 * component-relative superblock number.
		 */
		if (ii->ii_ndisk == 1) {
			/*
			 * When we have just one disk, it can't be a mirror
			 * or a parity config.
			 */
			ccdisk = ii->ii_index[0];
			cbn = ii->ii_startoff + off;
		} else {
			if (cs->sc_cflags & CCDF_MIRROR) {
				/*
				 * We have forced a uniform mapping, resulting
				 * in a single interleave array.  We double
				 * up on the first half of the available
				 * components and our mirror is in the second
				 * half.  This only works with a single
				 * interleave array because doubling up
				 * doubles the number of sectors, so there
				 * cannot be another interleave array because
				 * the next interleave array's calculations
				 * would be off.
				 */
				int ndisk2 = ii->ii_ndisk / 2;
				ccdisk = ii->ii_index[off % ndisk2];
				cbn = ii->ii_startoff + off / ndisk2;
				ci2 = &cs->sc_cinfo[ccdisk + ndisk2];
			} else if (cs->sc_cflags & CCDF_PARITY) {
				/*
				 * XXX not implemented yet
				 */
				int ndisk2 = ii->ii_ndisk - 1;
				ccdisk = ii->ii_index[off % ndisk2];
				cbn = ii->ii_startoff + off / ndisk2;
				if (cbn % ii->ii_ndisk <= ccdisk)
					ccdisk++;
			} else {
				ccdisk = ii->ii_index[off % ii->ii_ndisk];
				cbn = ii->ii_startoff + off / ii->ii_ndisk;
			}
		}

		ci = &cs->sc_cinfo[ccdisk];

		/*
		 * Convert cbn from a superblock to a normal block so it
		 * can be used to calculate (along with cboff) the normal
		 * block index into this particular disk.
		 */
		cbn *= cs->sc_ileave;
	}

	/*
	 * Fill in the component buf structure.
	 *
	 * NOTE: devices do not use b_bufsize, only b_bcount, but b_bcount
	 * will be truncated on device EOF so we use b_bufsize to detect
	 * the case.
	 */
	cbp = getccdbuf();
	cbp->cb_buf.b_cmd = bio->bio_buf->b_cmd;
	cbp->cb_buf.b_flags |= bio->bio_buf->b_flags;
	cbp->cb_buf.b_data = addr;
	cbp->cb_vp = ci->ci_vp;
	if (cs->sc_ileave == 0)
		cbc = dbtob((off_t)(ci->ci_size - cbn));
	else
		cbc = dbtob((off_t)(cs->sc_ileave - cboff));
	if (cbc > cs->sc_maxiosize)
		cbc = cs->sc_maxiosize;
	cbp->cb_buf.b_bcount = (cbc < bcount) ? cbc : bcount;
 	cbp->cb_buf.b_bufsize = cbp->cb_buf.b_bcount;

	cbp->cb_buf.b_bio1.bio_done = ccdiodone;
	cbp->cb_buf.b_bio1.bio_caller_info1.ptr = cbp;
	cbp->cb_buf.b_bio1.bio_offset = dbtob(cbn + cboff + ci->ci_skip);

	/*
	 * context for ccdiodone
	 */
	cbp->cb_obio = bio;
	cbp->cb_unit = cs - ccd_softc;
	cbp->cb_comp = ci - cs->sc_cinfo;

#ifdef DEBUG
	if (ccddebug & CCDB_IO)
		kprintf(" dev %x(u%d): cbp %x off %lld addr %x bcnt %d\n",
		       ci->ci_dev, ci-cs->sc_cinfo, cbp,
		       cbp->cb_buf.b_bio1.bio_offset,
		       cbp->cb_buf.b_data, cbp->cb_buf.b_bcount);
#endif
	cb[0] = cbp;

	/*
	 * Note: both I/O's setup when reading from mirror, but only one
	 * will be executed.
	 */
	if (cs->sc_cflags & CCDF_MIRROR) {
		/* mirror, setup second I/O */
		cbp = getccdbuf();

		cbp->cb_buf.b_cmd = bio->bio_buf->b_cmd;
		cbp->cb_buf.b_flags |= bio->bio_buf->b_flags;
		cbp->cb_buf.b_data = addr;
		cbp->cb_vp = ci2->ci_vp;
		if (cs->sc_ileave == 0)
		      cbc = dbtob((off_t)(ci->ci_size - cbn));
		else
		      cbc = dbtob((off_t)(cs->sc_ileave - cboff));
		if (cbc > cs->sc_maxiosize)
			cbc = cs->sc_maxiosize;
		cbp->cb_buf.b_bcount = (cbc < bcount) ? cbc : bcount;
		cbp->cb_buf.b_bufsize = cbp->cb_buf.b_bcount;

		cbp->cb_buf.b_bio1.bio_done = ccdiodone;
		cbp->cb_buf.b_bio1.bio_caller_info1.ptr = cbp;
		cbp->cb_buf.b_bio1.bio_offset = dbtob(cbn + cboff + ci2->ci_skip);

		/*
		 * context for ccdiodone
		 */
		cbp->cb_obio = bio;
		cbp->cb_unit = cs - ccd_softc;
		cbp->cb_comp = ci2 - cs->sc_cinfo;
		cb[1] = cbp;
		/* link together the ccdbuf's and clear "mirror done" flag */
		cb[0]->cb_mirror = cb[1];
		cb[1]->cb_mirror = cb[0];
		cb[0]->cb_pflags &= ~CCDPF_MIRROR_DONE;
		cb[1]->cb_pflags &= ~CCDPF_MIRROR_DONE;
	}
}

static void
ccdintr(struct ccd_softc *cs, struct bio *bio)
{
	struct buf *bp = bio->bio_buf;

#ifdef DEBUG
	if (ccddebug & CCDB_FOLLOW)
		kprintf("ccdintr(%x, %x)\n", cs, bp);
#endif
	/*
	 * Request is done for better or worse, wakeup the top half.
	 */
	if (bp->b_flags & B_ERROR)
		bp->b_resid = bp->b_bcount;
	devstat_end_transaction_buf(&cs->device_stats, bp);
	biodone(bio);
}

/*
 * Called at interrupt time.
 *
 * Mark the component as done and if all components are done,
 * take a ccd interrupt.
 */
static void
ccdiodone(struct bio *bio)
{
	struct ccdbuf *cbp = bio->bio_caller_info1.ptr;
	struct bio *obio = cbp->cb_obio;
	struct buf *obp = obio->bio_buf;
	int unit = cbp->cb_unit;
	struct ccd_softc *sc = &ccd_softc[unit];
	int count;

	/*
	 * Since we do not have exclusive access to underlying devices,
	 * we can't keep cache translations around.
	 */
	clearbiocache(bio->bio_next);

	ccdlock(sc);

#ifdef DEBUG
	if (ccddebug & CCDB_FOLLOW)
		kprintf("ccdiodone(%x)\n", cbp);
	if (ccddebug & CCDB_IO) {
		kprintf("ccdiodone: bp %x bcount %d resid %d\n",
		       obp, obp->b_bcount, obp->b_resid);
		kprintf(" dev %x(u%d), cbp %x off %lld addr %x bcnt %d\n",
		       cbp->cb_buf.b_dev, cbp->cb_comp, cbp,
		       cbp->cb_buf.b_loffset, cbp->cb_buf.b_data,
		       cbp->cb_buf.b_bcount);
	}
#endif

	/*
	 * If an error occured, report it.  If this is a mirrored
	 * configuration and the first of two possible reads, do not
	 * set the error in the bp yet because the second read may
	 * succeed.
	 */
	if (cbp->cb_buf.b_flags & B_ERROR) {
		const char *msg = "";

		if ((sc->sc_cflags & CCDF_MIRROR) &&
		    (cbp->cb_buf.b_cmd == BUF_CMD_READ) &&
		    (cbp->cb_pflags & CCDPF_MIRROR_DONE) == 0) {
			/*
			 * We will try our read on the other disk down
			 * below, also reverse the default pick so if we
			 * are doing a scan we do not keep hitting the
			 * bad disk first.
			 */
			msg = ", trying other disk";
			sc->sc_pick = 1 - sc->sc_pick;
			sc->sc_blk[sc->sc_pick] = obio->bio_offset;
		} else {
			obp->b_flags |= B_ERROR;
			obp->b_error = cbp->cb_buf.b_error ?
			    cbp->cb_buf.b_error : EIO;
		}
		kprintf("ccd%d: error %d on component %d "
			"offset %jd (ccd offset %jd)%s\n",
		        unit, obp->b_error, cbp->cb_comp,
		        (intmax_t)cbp->cb_buf.b_bio2.bio_offset,
		        (intmax_t)obio->bio_offset,
		        msg);
	}

	/*
	 * Process mirror.  If we are writing, I/O has been initiated on both
	 * buffers and we fall through only after both are finished.
	 *
	 * If we are reading only one I/O is initiated at a time.  If an
	 * error occurs we initiate the second I/O and return, otherwise
	 * we free the second I/O without initiating it.
	 */

	if (sc->sc_cflags & CCDF_MIRROR) {
		if (cbp->cb_buf.b_cmd != BUF_CMD_READ) {
			/*
			 * When writing, handshake with the second buffer
			 * to determine when both are done.  If both are not
			 * done, return here.
			 */
			if ((cbp->cb_pflags & CCDPF_MIRROR_DONE) == 0) {
				cbp->cb_mirror->cb_pflags |= CCDPF_MIRROR_DONE;
				putccdbuf(cbp);
				ccdunlock(sc);
				return;
			}
		} else {
			/*
			 * When reading, either dispose of the second buffer
			 * or initiate I/O on the second buffer if an error
			 * occured with this one.
			 */
			if ((cbp->cb_pflags & CCDPF_MIRROR_DONE) == 0) {
				if (cbp->cb_buf.b_flags & B_ERROR) {
					cbp->cb_mirror->cb_pflags |=
					    CCDPF_MIRROR_DONE;
					vn_strategy(
					    cbp->cb_mirror->cb_vp,
					    &cbp->cb_mirror->cb_buf.b_bio1
					);
					putccdbuf(cbp);
					ccdunlock(sc);
					return;
				} else {
					putccdbuf(cbp->cb_mirror);
					/* fall through */
				}
			}
		}
	}

	/*
	 * Use our saved b_bufsize to determine if an unexpected EOF occured.
	 */
	count = cbp->cb_buf.b_bufsize;
	putccdbuf(cbp);

	/*
	 * If all done, "interrupt".
	 */
	obp->b_resid -= count;
	if (obp->b_resid < 0)
		panic("ccdiodone: count");

	ccdunlock(sc);

	if (obp->b_resid == 0)
		ccdintr(sc, obio);
}

static int
ccdioctl(struct dev_ioctl_args *ap)
{
	cdev_t dev = ap->a_head.a_dev;
	int unit = ccdunit(dev);
	int i, j, lookedup = 0, error = 0;
	struct ccd_softc *cs;
	struct ccd_ioctl *ccio = (struct ccd_ioctl *)ap->a_data;
	struct ccddevice ccd;
	struct disk_info info;
	char **cpp;
	struct vnode **vpp;

	if (unit >= numccd)
		return (ENXIO);
	cs = &ccd_softc[unit];

	bzero(&ccd, sizeof(ccd));

	switch (ap->a_cmd) {
	case CCDIOCSET:
		if (cs->sc_flags & CCDF_INITED)
			return (EBUSY);

		if ((ap->a_fflag & FWRITE) == 0)
			return (EBADF);

		if ((error = ccdlock(cs)) != 0)
			return (error);

		if (ccio->ccio_ndisks > CCD_MAXNDISKS) {
			ccdunlock(cs);
			return (EINVAL);
		}

		/* Fill in some important bits. */
		ccd.ccd_unit = unit;
		ccd.ccd_interleave = ccio->ccio_ileave;
		if (ccd.ccd_interleave == 0 &&
		    ((ccio->ccio_flags & CCDF_MIRROR) ||
		     (ccio->ccio_flags & CCDF_PARITY))) {
			kprintf("ccd%d: disabling mirror/parity, interleave is 0\n", unit);
			ccio->ccio_flags &= ~(CCDF_MIRROR | CCDF_PARITY);
		}
		if ((ccio->ccio_flags & CCDF_MIRROR) &&
		    (ccio->ccio_flags & CCDF_PARITY)) {
			kprintf("ccd%d: can't specify both mirror and parity, using mirror\n", unit);
			ccio->ccio_flags &= ~CCDF_PARITY;
		}
		if ((ccio->ccio_flags & (CCDF_MIRROR | CCDF_PARITY)) &&
		    !(ccio->ccio_flags & CCDF_UNIFORM)) {
			kprintf("ccd%d: mirror/parity forces uniform flag\n",
			       unit);
			ccio->ccio_flags |= CCDF_UNIFORM;
		}
		ccd.ccd_flags = ccio->ccio_flags & CCDF_USERMASK;

		/*
		 * Allocate space for and copy in the array of
		 * componet pathnames and device numbers.
		 */
		cpp = kmalloc(ccio->ccio_ndisks * sizeof(char *),
		    M_DEVBUF, M_WAITOK);
		vpp = kmalloc(ccio->ccio_ndisks * sizeof(struct vnode *),
		    M_DEVBUF, M_WAITOK);

		error = copyin((caddr_t)ccio->ccio_disks, (caddr_t)cpp,
				ccio->ccio_ndisks * sizeof(char **));
		if (error) {
			kfree(vpp, M_DEVBUF);
			kfree(cpp, M_DEVBUF);
			ccdunlock(cs);
			return (error);
		}

#ifdef DEBUG
		if (ccddebug & CCDB_INIT) {
			for (i = 0; i < ccio->ccio_ndisks; ++i)
				kprintf("ccdioctl: component %d: 0x%x\n",
				    i, cpp[i]);
		}
#endif

		for (i = 0; i < ccio->ccio_ndisks; ++i) {
#ifdef DEBUG
			if (ccddebug & CCDB_INIT)
				kprintf("ccdioctl: lookedup = %d\n", lookedup);
#endif
			if ((error = ccdlookup(cpp[i], &vpp[i])) != 0) {
				for (j = 0; j < lookedup; ++j)
					(void)vn_close(vpp[j], FREAD|FWRITE, NULL);
				kfree(vpp, M_DEVBUF);
				kfree(cpp, M_DEVBUF);
				ccdunlock(cs);
				return (error);
			}
			++lookedup;
		}
		ccd.ccd_cpp = cpp;
		ccd.ccd_vpp = vpp;
		ccd.ccd_ndev = ccio->ccio_ndisks;

		/*
		 * Initialize the ccd.  Fills in the softc for us.
		 */
		if ((error = ccdinit(&ccd, cpp, ap->a_cred)) != 0) {
			for (j = 0; j < lookedup; ++j)
				vn_close(vpp[j], FREAD|FWRITE, NULL);
			kfree(vpp, M_DEVBUF);
			kfree(cpp, M_DEVBUF);
			ccdunlock(cs);
			return (error);
		}

		/*
		 * The ccd has been successfully initialized, so
		 * we can place it into the array and read the disklabel.
		 */
		bcopy(&ccd, &ccddevs[unit], sizeof(ccd));
		ccio->ccio_unit = unit;
		ccio->ccio_size = cs->sc_size;

		bzero(&info, sizeof(info));
		info.d_media_blksize = cs->sc_geom.ccg_secsize;
		info.d_media_blocks  = cs->sc_size;
		info.d_nheads	     = cs->sc_geom.ccg_ntracks;
		info.d_secpertrack   = cs->sc_geom.ccg_nsectors;
		info.d_ncylinders    = cs->sc_geom.ccg_ncylinders;
		info.d_secpercyl     = info.d_nheads * info.d_secpertrack;
		disk_setdiskinfo(&cs->sc_disk, &info);

		ccdunlock(cs);

		break;

	case CCDIOCCLR:
		if ((cs->sc_flags & CCDF_INITED) == 0)
			return (ENXIO);

		if ((ap->a_fflag & FWRITE) == 0)
			return (EBADF);

		if ((error = ccdlock(cs)) != 0)
			return (error);

		if (dev_drefs(cs->sc_dev) > 1) {
			ccdunlock(cs);
			return (EBUSY);
		}

		/*
		 * Free ccd_softc information and clear entry.
		 */

		/* Close the components and free their pathnames. */
		for (i = 0; i < cs->sc_nccdisks; ++i) {
			/*
			 * XXX: this close could potentially fail and
			 * cause Bad Things.  Maybe we need to force
			 * the close to happen?
			 */
#ifdef DEBUG
			if (ccddebug & CCDB_VNODE)
				vprint("CCDIOCCLR: vnode info",
				    cs->sc_cinfo[i].ci_vp);
#endif
			(void)vn_close(cs->sc_cinfo[i].ci_vp, FREAD|FWRITE, NULL);
			kfree(cs->sc_cinfo[i].ci_path, M_DEVBUF);
		}

		/* Free interleave index. */
		for (i = 0; cs->sc_itable[i].ii_ndisk; ++i)
			kfree(cs->sc_itable[i].ii_index, M_DEVBUF);

		/* Free component info and interleave table. */
		kfree(cs->sc_cinfo, M_DEVBUF);
		kfree(cs->sc_itable, M_DEVBUF);
		cs->sc_cinfo = NULL;
		cs->sc_itable = NULL;
		cs->sc_flags &= ~CCDF_INITED;

		/*
		 * Free ccddevice information and clear entry.
		 */
		kfree(ccddevs[unit].ccd_cpp, M_DEVBUF);
		kfree(ccddevs[unit].ccd_vpp, M_DEVBUF);
		bcopy(&ccd, &ccddevs[unit], sizeof(ccd));

		/*
		 * And remove the devstat entry.
		 */
		devstat_remove_entry(&cs->device_stats);

		ccdunlock(cs);

		break;

	default:
		return (ENOTTY);
	}

	return (0);
}

static int
ccddump(struct dev_dump_args *ap)
{
	/* Not implemented. */
	return ENXIO;
}

/*
 * Lookup the provided name in the filesystem.  If the file exists,
 * is a valid block device, and isn't being used by anyone else,
 * set *vpp to the file's vnode.
 */
static int
ccdlookup(char *path, struct vnode **vpp)
{
	struct nlookupdata nd;
	struct vnode *vp;
	int error;

	*vpp = NULL;

	error = nlookup_init(&nd, path, UIO_USERSPACE, NLC_FOLLOW|NLC_LOCKVP);
	if (error)
		return (error);
	if ((error = vn_open(&nd, NULL, FREAD|FWRITE, 0)) != 0) {
#ifdef DEBUG
		if (ccddebug & (CCDB_FOLLOW|CCDB_INIT))
			kprintf("ccdlookup: vn_open error = %d\n", error);
#endif
		goto done;
	}
	vp = nd.nl_open_vp;

	if (vp->v_opencount > 1) {
		error = EBUSY;
		goto done;
	}

	if (!vn_isdisk(vp, &error))
		goto done;

#ifdef DEBUG
	if (ccddebug & CCDB_VNODE)
		vprint("ccdlookup: vnode info", vp);
#endif

	vn_unlock(vp);
	nd.nl_open_vp = NULL;
	nlookup_done(&nd);
	*vpp = vp;				/* leave ref intact  */
	return (0);
done:
	nlookup_done(&nd);
	return (error);
}

/*
 * Wait interruptibly for an exclusive lock.
 */
static int
ccdlock(struct ccd_softc *cs)
{
	lockmgr(&cs->sc_lock, LK_EXCLUSIVE);

	return (0);
}

/*
 * Unlock and wake up any waiters.
 */
static void
ccdunlock(struct ccd_softc *cs)
{
	lockmgr(&cs->sc_lock, LK_RELEASE);
}

#ifdef DEBUG
static void
printiinfo(struct ccdiinfo *ii)
{
	int ix, i;

	for (ix = 0; ii->ii_ndisk; ix++, ii++) {
		kprintf(" itab[%d]: #dk %d sblk %d soff %d",
		       ix, ii->ii_ndisk, ii->ii_startblk, ii->ii_startoff);
		for (i = 0; i < ii->ii_ndisk; i++)
			kprintf(" %d", ii->ii_index[i]);
		kprintf("\n");
	}
}
#endif