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ccd.c revision 1.152
      1 /*	$NetBSD: ccd.c,v 1.152 2014/08/16 19:27:27 sborrill Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1996, 1997, 1998, 1999, 2007, 2009 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Jason R. Thorpe, and by Andrew Doran.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29  * POSSIBILITY OF SUCH DAMAGE.
     30  */
     31 
     32 /*
     33  * Copyright (c) 1988 University of Utah.
     34  * Copyright (c) 1990, 1993
     35  *	The Regents of the University of California.  All rights reserved.
     36  *
     37  * This code is derived from software contributed to Berkeley by
     38  * the Systems Programming Group of the University of Utah Computer
     39  * Science Department.
     40  *
     41  * Redistribution and use in source and binary forms, with or without
     42  * modification, are permitted provided that the following conditions
     43  * are met:
     44  * 1. Redistributions of source code must retain the above copyright
     45  *    notice, this list of conditions and the following disclaimer.
     46  * 2. Redistributions in binary form must reproduce the above copyright
     47  *    notice, this list of conditions and the following disclaimer in the
     48  *    documentation and/or other materials provided with the distribution.
     49  * 3. Neither the name of the University nor the names of its contributors
     50  *    may be used to endorse or promote products derived from this software
     51  *    without specific prior written permission.
     52  *
     53  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     54  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     55  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     56  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     57  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     58  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     59  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     60  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     61  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     62  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     63  * SUCH DAMAGE.
     64  *
     65  * from: Utah $Hdr: cd.c 1.6 90/11/28$
     66  *
     67  *	@(#)cd.c	8.2 (Berkeley) 11/16/93
     68  */
     69 
     70 /*
     71  * "Concatenated" disk driver.
     72  *
     73  * Notes on concurrency:
     74  *
     75  * => sc_dvlock serializes access to the device nodes, excluding block I/O.
     76  *
     77  * => sc_iolock serializes access to (sc_flags & CCDF_INITED), disk stats,
     78  *    sc_stop, sc_bufq and b_resid from master buffers.
     79  *
     80  * => a combination of CCDF_INITED, sc_inflight, and sc_iolock is used to
     81  *    serialize I/O and configuration changes.
     82  *
     83  * => the in-core disk label does not change while the device is open.
     84  *
     85  * On memory consumption: ccd fans out I/O requests and so needs to
     86  * allocate memory.  If the system is desperately low on memory, we
     87  * single thread I/O.
     88  */
     89 
     90 #include <sys/cdefs.h>
     91 __KERNEL_RCSID(0, "$NetBSD: ccd.c,v 1.152 2014/08/16 19:27:27 sborrill Exp $");
     92 
     93 #if defined(_KERNEL_OPT)
     94 #include "opt_compat_netbsd.h"
     95 #endif
     96 
     97 #include <sys/param.h>
     98 #include <sys/systm.h>
     99 #include <sys/kernel.h>
    100 #include <sys/proc.h>
    101 #include <sys/errno.h>
    102 #include <sys/buf.h>
    103 #include <sys/kmem.h>
    104 #include <sys/pool.h>
    105 #include <sys/module.h>
    106 #include <sys/namei.h>
    107 #include <sys/stat.h>
    108 #include <sys/ioctl.h>
    109 #include <sys/disklabel.h>
    110 #include <sys/device.h>
    111 #include <sys/disk.h>
    112 #include <sys/syslog.h>
    113 #include <sys/fcntl.h>
    114 #include <sys/vnode.h>
    115 #include <sys/conf.h>
    116 #include <sys/mutex.h>
    117 #include <sys/queue.h>
    118 #include <sys/kauth.h>
    119 #include <sys/kthread.h>
    120 #include <sys/bufq.h>
    121 #include <sys/sysctl.h>
    122 
    123 #include <uvm/uvm_extern.h>
    124 
    125 #include <dev/ccdvar.h>
    126 #include <dev/dkvar.h>
    127 
    128 #include <miscfs/specfs/specdev.h> /* for v_rdev */
    129 
    130 #if defined(CCDDEBUG) && !defined(DEBUG)
    131 #define DEBUG
    132 #endif
    133 
    134 #ifdef DEBUG
    135 #define CCDB_FOLLOW	0x01
    136 #define CCDB_INIT	0x02
    137 #define CCDB_IO		0x04
    138 #define CCDB_LABEL	0x08
    139 #define CCDB_VNODE	0x10
    140 int ccddebug = 0x00;
    141 #endif
    142 
    143 #define	ccdunit(x)	DISKUNIT(x)
    144 
    145 struct ccdbuf {
    146 	struct buf	cb_buf;		/* new I/O buf */
    147 	struct buf	*cb_obp;	/* ptr. to original I/O buf */
    148 	struct ccd_softc *cb_sc;	/* pointer to ccd softc */
    149 	int		cb_comp;	/* target component */
    150 	SIMPLEQ_ENTRY(ccdbuf) cb_q;	/* fifo of component buffers */
    151 };
    152 
    153 /* component buffer pool */
    154 static pool_cache_t ccd_cache;
    155 
    156 #define	CCD_GETBUF()		pool_cache_get(ccd_cache, PR_WAITOK)
    157 #define	CCD_PUTBUF(cbp)		pool_cache_put(ccd_cache, cbp)
    158 
    159 #define CCDLABELDEV(dev)	\
    160 	(MAKEDISKDEV(major((dev)), ccdunit((dev)), RAW_PART))
    161 
    162 /* called by main() at boot time */
    163 void	ccdattach(int);
    164 
    165 /* called by biodone() at interrupt time */
    166 static void	ccdiodone(struct buf *);
    167 
    168 static void	ccdinterleave(struct ccd_softc *);
    169 static int	ccdinit(struct ccd_softc *, char **, struct vnode **,
    170 		    struct lwp *);
    171 static struct ccdbuf *ccdbuffer(struct ccd_softc *, struct buf *,
    172 		    daddr_t, void *, long);
    173 static void	ccdgetdefaultlabel(struct ccd_softc *, struct disklabel *);
    174 static void	ccdgetdisklabel(dev_t);
    175 static void	ccdmakedisklabel(struct ccd_softc *);
    176 static void	ccdstart(struct ccd_softc *);
    177 static void	ccdthread(void *);
    178 
    179 static dev_type_open(ccdopen);
    180 static dev_type_close(ccdclose);
    181 static dev_type_read(ccdread);
    182 static dev_type_write(ccdwrite);
    183 static dev_type_ioctl(ccdioctl);
    184 static dev_type_strategy(ccdstrategy);
    185 static dev_type_size(ccdsize);
    186 
    187 const struct bdevsw ccd_bdevsw = {
    188 	.d_open = ccdopen,
    189 	.d_close = ccdclose,
    190 	.d_strategy = ccdstrategy,
    191 	.d_ioctl = ccdioctl,
    192 	.d_dump = nodump,
    193 	.d_psize = ccdsize,
    194 	.d_discard = nodiscard,
    195 	.d_flag = D_DISK | D_MPSAFE
    196 };
    197 
    198 const struct cdevsw ccd_cdevsw = {
    199 	.d_open = ccdopen,
    200 	.d_close = ccdclose,
    201 	.d_read = ccdread,
    202 	.d_write = ccdwrite,
    203 	.d_ioctl = ccdioctl,
    204 	.d_stop = nostop,
    205 	.d_tty = notty,
    206 	.d_poll = nopoll,
    207 	.d_mmap = nommap,
    208 	.d_kqfilter = nokqfilter,
    209 	.d_discard = nodiscard,
    210 	.d_flag = D_DISK | D_MPSAFE
    211 };
    212 
    213 #ifdef DEBUG
    214 static	void printiinfo(struct ccdiinfo *);
    215 #endif
    216 
    217 static LIST_HEAD(, ccd_softc) ccds = LIST_HEAD_INITIALIZER(ccds);
    218 static kmutex_t ccd_lock;
    219 
    220 static struct ccd_softc *
    221 ccdcreate(int unit) {
    222 	struct ccd_softc *sc = kmem_zalloc(sizeof(*sc), KM_SLEEP);
    223 	if (sc == NULL) {
    224 #ifdef DIAGNOSTIC
    225 		printf("%s: out of memory\n", __func__);
    226 #endif
    227 		return NULL;
    228 	}
    229 	/* Initialize per-softc structures. */
    230 	snprintf(sc->sc_xname, sizeof(sc->sc_xname), "ccd%d", unit);
    231 	mutex_init(&sc->sc_dvlock, MUTEX_DEFAULT, IPL_NONE);
    232 	sc->sc_iolock = mutex_obj_alloc(MUTEX_DEFAULT, IPL_NONE);
    233 	cv_init(&sc->sc_stop, "ccdstop");
    234 	cv_init(&sc->sc_push, "ccdthr");
    235 	disk_init(&sc->sc_dkdev, sc->sc_xname, NULL); /* XXX */
    236 	return sc;
    237 }
    238 
    239 static void
    240 ccddestroy(struct ccd_softc *sc) {
    241 	mutex_obj_free(sc->sc_iolock);
    242 	mutex_exit(&sc->sc_dvlock);
    243 	mutex_destroy(&sc->sc_dvlock);
    244 	cv_destroy(&sc->sc_stop);
    245 	cv_destroy(&sc->sc_push);
    246 	disk_destroy(&sc->sc_dkdev);
    247 	kmem_free(sc, sizeof(*sc));
    248 }
    249 
    250 static struct ccd_softc *
    251 ccdget(int unit) {
    252 	struct ccd_softc *sc;
    253 	if (unit < 0) {
    254 #ifdef DIAGNOSTIC
    255 		panic("%s: unit %d!", __func__, unit);
    256 #endif
    257 		return NULL;
    258 	}
    259 	mutex_enter(&ccd_lock);
    260 	LIST_FOREACH(sc, &ccds, sc_link) {
    261 		if (sc->sc_unit == unit) {
    262 			mutex_exit(&ccd_lock);
    263 			return sc;
    264 		}
    265 	}
    266 	mutex_exit(&ccd_lock);
    267 	if ((sc = ccdcreate(unit)) == NULL)
    268 		return NULL;
    269 	mutex_enter(&ccd_lock);
    270 	LIST_INSERT_HEAD(&ccds, sc, sc_link);
    271 	mutex_exit(&ccd_lock);
    272 	return sc;
    273 }
    274 
    275 static void
    276 ccdput(struct ccd_softc *sc) {
    277 	mutex_enter(&ccd_lock);
    278 	LIST_REMOVE(sc, sc_link);
    279 	mutex_exit(&ccd_lock);
    280 	ccddestroy(sc);
    281 }
    282 
    283 /*
    284  * Called by main() during pseudo-device attachment.  All we need
    285  * to do is allocate enough space for devices to be configured later.
    286  */
    287 void
    288 ccdattach(int num)
    289 {
    290 	mutex_init(&ccd_lock, MUTEX_DEFAULT, IPL_NONE);
    291 
    292 	/* Initialize the component buffer pool. */
    293 	ccd_cache = pool_cache_init(sizeof(struct ccdbuf), 0,
    294 	    0, 0, "ccdbuf", NULL, IPL_BIO, NULL, NULL, NULL);
    295 }
    296 
    297 static int
    298 ccdinit(struct ccd_softc *cs, char **cpaths, struct vnode **vpp,
    299     struct lwp *l)
    300 {
    301 	struct ccdcinfo *ci = NULL;
    302 	int ix;
    303 	struct ccdgeom *ccg = &cs->sc_geom;
    304 	char *tmppath;
    305 	int error, path_alloced;
    306 	uint64_t psize, minsize;
    307 	unsigned secsize, maxsecsize;
    308 
    309 #ifdef DEBUG
    310 	if (ccddebug & (CCDB_FOLLOW|CCDB_INIT))
    311 		printf("%s: ccdinit\n", cs->sc_xname);
    312 #endif
    313 
    314 	/* Allocate space for the component info. */
    315 	cs->sc_cinfo = kmem_alloc(cs->sc_nccdisks * sizeof(*cs->sc_cinfo),
    316 	    KM_SLEEP);
    317 	tmppath = kmem_alloc(MAXPATHLEN, KM_SLEEP);
    318 
    319 	cs->sc_size = 0;
    320 
    321 	/*
    322 	 * Verify that each component piece exists and record
    323 	 * relevant information about it.
    324 	 */
    325 	maxsecsize = 0;
    326 	minsize = 0;
    327 	for (ix = 0, path_alloced = 0; ix < cs->sc_nccdisks; ix++) {
    328 		ci = &cs->sc_cinfo[ix];
    329 		ci->ci_vp = vpp[ix];
    330 
    331 		/*
    332 		 * Copy in the pathname of the component.
    333 		 */
    334 		memset(tmppath, 0, MAXPATHLEN);	/* sanity */
    335 		error = copyinstr(cpaths[ix], tmppath,
    336 		    MAXPATHLEN, &ci->ci_pathlen);
    337 		if (ci->ci_pathlen == 0)
    338 			error = EINVAL;
    339 		if (error) {
    340 #ifdef DEBUG
    341 			if (ccddebug & (CCDB_FOLLOW|CCDB_INIT))
    342 				printf("%s: can't copy path, error = %d\n",
    343 				    cs->sc_xname, error);
    344 #endif
    345 			goto out;
    346 		}
    347 		ci->ci_path = kmem_alloc(ci->ci_pathlen, KM_SLEEP);
    348 		memcpy(ci->ci_path, tmppath, ci->ci_pathlen);
    349 		path_alloced++;
    350 
    351 		/*
    352 		 * XXX: Cache the component's dev_t.
    353 		 */
    354 		ci->ci_dev = vpp[ix]->v_rdev;
    355 
    356 		/*
    357 		 * Get partition information for the component.
    358 		 */
    359 		error = getdisksize(vpp[ix], &psize, &secsize);
    360 		if (error) {
    361 #ifdef DEBUG
    362 			if (ccddebug & (CCDB_FOLLOW|CCDB_INIT))
    363 				 printf("%s: %s: disksize failed, error = %d\n",
    364 				     cs->sc_xname, ci->ci_path, error);
    365 #endif
    366 			goto out;
    367 		}
    368 
    369 		/*
    370 		 * Calculate the size, truncating to an interleave
    371 		 * boundary if necessary.
    372 		 */
    373 		maxsecsize = secsize > maxsecsize ? secsize : maxsecsize;
    374 		if (cs->sc_ileave > 1)
    375 			psize -= psize % cs->sc_ileave;
    376 
    377 		if (psize == 0) {
    378 #ifdef DEBUG
    379 			if (ccddebug & (CCDB_FOLLOW|CCDB_INIT))
    380 				printf("%s: %s: size == 0\n",
    381 				    cs->sc_xname, ci->ci_path);
    382 #endif
    383 			error = ENODEV;
    384 			goto out;
    385 		}
    386 
    387 		if (minsize == 0 || psize < minsize)
    388 			minsize = psize;
    389 		ci->ci_size = psize;
    390 		cs->sc_size += psize;
    391 	}
    392 
    393 	/*
    394 	 * Don't allow the interleave to be smaller than
    395 	 * the biggest component sector.
    396 	 */
    397 	if ((cs->sc_ileave > 0) &&
    398 	    (cs->sc_ileave < (maxsecsize / DEV_BSIZE))) {
    399 #ifdef DEBUG
    400 		if (ccddebug & (CCDB_FOLLOW|CCDB_INIT))
    401 			printf("%s: interleave must be at least %d\n",
    402 			    cs->sc_xname, (maxsecsize / DEV_BSIZE));
    403 #endif
    404 		error = EINVAL;
    405 		goto out;
    406 	}
    407 
    408 	/*
    409 	 * If uniform interleave is desired set all sizes to that of
    410 	 * the smallest component.
    411 	 */
    412 	if (cs->sc_flags & CCDF_UNIFORM) {
    413 		for (ci = cs->sc_cinfo;
    414 		     ci < &cs->sc_cinfo[cs->sc_nccdisks]; ci++)
    415 			ci->ci_size = minsize;
    416 
    417 		cs->sc_size = cs->sc_nccdisks * minsize;
    418 	}
    419 
    420 	/*
    421 	 * Construct the interleave table.
    422 	 */
    423 	ccdinterleave(cs);
    424 
    425 	/*
    426 	 * Create pseudo-geometry based on 1MB cylinders.  It's
    427 	 * pretty close.
    428 	 */
    429 	ccg->ccg_secsize = DEV_BSIZE;
    430 	ccg->ccg_ntracks = 1;
    431 	ccg->ccg_nsectors = 1024 * (1024 / ccg->ccg_secsize);
    432 	ccg->ccg_ncylinders = cs->sc_size / ccg->ccg_nsectors;
    433 
    434 	if (cs->sc_ileave > 0)
    435 	        aprint_normal("%s: Interleaving %d component%s "
    436 	            "(%d block interleave)\n", cs->sc_xname,
    437         	    cs->sc_nccdisks, (cs->sc_nccdisks != 0 ? "s" : ""),
    438         	    cs->sc_ileave);
    439 	else
    440 	        aprint_normal("%s: Concatenating %d component%s\n",
    441 	            cs->sc_xname,
    442         	    cs->sc_nccdisks, (cs->sc_nccdisks != 0 ? "s" : ""));
    443 	for (ix = 0; ix < cs->sc_nccdisks; ix++) {
    444 		ci = &cs->sc_cinfo[ix];
    445 		aprint_normal("%s: %s (%ju blocks)\n", cs->sc_xname,
    446 		    ci->ci_path, (uintmax_t)ci->ci_size);
    447 	}
    448 	aprint_normal("%s: total %ju blocks\n", cs->sc_xname, cs->sc_size);
    449 
    450 	/*
    451 	 * Create thread to handle deferred I/O.
    452 	 */
    453 	cs->sc_zap = false;
    454 	error = kthread_create(PRI_BIO, KTHREAD_MPSAFE, NULL, ccdthread,
    455 	    cs, &cs->sc_thread, "%s", cs->sc_xname);
    456 	if (error) {
    457 		printf("ccdinit: can't create thread: %d\n", error);
    458 		goto out;
    459 	}
    460 
    461 	/*
    462 	 * Only now that everything is set up can we enable the device.
    463 	 */
    464 	mutex_enter(cs->sc_iolock);
    465 	cs->sc_flags |= CCDF_INITED;
    466 	mutex_exit(cs->sc_iolock);
    467 	kmem_free(tmppath, MAXPATHLEN);
    468 	return (0);
    469 
    470  out:
    471 	for (ix = 0; ix < path_alloced; ix++) {
    472 		kmem_free(cs->sc_cinfo[ix].ci_path,
    473 		    cs->sc_cinfo[ix].ci_pathlen);
    474 	}
    475 	kmem_free(cs->sc_cinfo, cs->sc_nccdisks * sizeof(struct ccdcinfo));
    476 	kmem_free(tmppath, MAXPATHLEN);
    477 	return (error);
    478 }
    479 
    480 static void
    481 ccdinterleave(struct ccd_softc *cs)
    482 {
    483 	struct ccdcinfo *ci, *smallci;
    484 	struct ccdiinfo *ii;
    485 	daddr_t bn, lbn;
    486 	int ix;
    487 	u_long size;
    488 
    489 #ifdef DEBUG
    490 	if (ccddebug & CCDB_INIT)
    491 		printf("ccdinterleave(%p): ileave %d\n", cs, cs->sc_ileave);
    492 #endif
    493 	/*
    494 	 * Allocate an interleave table.
    495 	 * Chances are this is too big, but we don't care.
    496 	 */
    497 	size = (cs->sc_nccdisks + 1) * sizeof(struct ccdiinfo);
    498 	cs->sc_itable = kmem_zalloc(size, KM_SLEEP);
    499 
    500 	/*
    501 	 * Trivial case: no interleave (actually interleave of disk size).
    502 	 * Each table entry represents a single component in its entirety.
    503 	 */
    504 	if (cs->sc_ileave == 0) {
    505 		bn = 0;
    506 		ii = cs->sc_itable;
    507 
    508 		for (ix = 0; ix < cs->sc_nccdisks; ix++) {
    509 			/* Allocate space for ii_index. */
    510 			ii->ii_indexsz = sizeof(int);
    511 			ii->ii_index = kmem_alloc(ii->ii_indexsz, KM_SLEEP);
    512 			ii->ii_ndisk = 1;
    513 			ii->ii_startblk = bn;
    514 			ii->ii_startoff = 0;
    515 			ii->ii_index[0] = ix;
    516 			bn += cs->sc_cinfo[ix].ci_size;
    517 			ii++;
    518 		}
    519 		ii->ii_ndisk = 0;
    520 #ifdef DEBUG
    521 		if (ccddebug & CCDB_INIT)
    522 			printiinfo(cs->sc_itable);
    523 #endif
    524 		return;
    525 	}
    526 
    527 	/*
    528 	 * The following isn't fast or pretty; it doesn't have to be.
    529 	 */
    530 	size = 0;
    531 	bn = lbn = 0;
    532 	for (ii = cs->sc_itable; ; ii++) {
    533 		/* Allocate space for ii_index. */
    534 		ii->ii_indexsz = sizeof(int) * cs->sc_nccdisks;
    535 		ii->ii_index = kmem_alloc(ii->ii_indexsz, KM_SLEEP);
    536 
    537 		/*
    538 		 * Locate the smallest of the remaining components
    539 		 */
    540 		smallci = NULL;
    541 		for (ci = cs->sc_cinfo;
    542 		     ci < &cs->sc_cinfo[cs->sc_nccdisks]; ci++)
    543 			if (ci->ci_size > size &&
    544 			    (smallci == NULL ||
    545 			     ci->ci_size < smallci->ci_size))
    546 				smallci = ci;
    547 
    548 		/*
    549 		 * Nobody left, all done
    550 		 */
    551 		if (smallci == NULL) {
    552 			ii->ii_ndisk = 0;
    553 			break;
    554 		}
    555 
    556 		/*
    557 		 * Record starting logical block and component offset
    558 		 */
    559 		ii->ii_startblk = bn / cs->sc_ileave;
    560 		ii->ii_startoff = lbn;
    561 
    562 		/*
    563 		 * Determine how many disks take part in this interleave
    564 		 * and record their indices.
    565 		 */
    566 		ix = 0;
    567 		for (ci = cs->sc_cinfo;
    568 		     ci < &cs->sc_cinfo[cs->sc_nccdisks]; ci++)
    569 			if (ci->ci_size >= smallci->ci_size)
    570 				ii->ii_index[ix++] = ci - cs->sc_cinfo;
    571 		ii->ii_ndisk = ix;
    572 		bn += ix * (smallci->ci_size - size);
    573 		lbn = smallci->ci_size / cs->sc_ileave;
    574 		size = smallci->ci_size;
    575 	}
    576 #ifdef DEBUG
    577 	if (ccddebug & CCDB_INIT)
    578 		printiinfo(cs->sc_itable);
    579 #endif
    580 }
    581 
    582 /* ARGSUSED */
    583 static int
    584 ccdopen(dev_t dev, int flags, int fmt, struct lwp *l)
    585 {
    586 	int unit = ccdunit(dev);
    587 	struct ccd_softc *cs;
    588 	struct disklabel *lp;
    589 	int error = 0, part, pmask;
    590 
    591 #ifdef DEBUG
    592 	if (ccddebug & CCDB_FOLLOW)
    593 		printf("ccdopen(0x%"PRIx64", 0x%x)\n", dev, flags);
    594 #endif
    595 	if ((cs = ccdget(unit)) == NULL)
    596 		return ENXIO;
    597 
    598 	mutex_enter(&cs->sc_dvlock);
    599 
    600 	lp = cs->sc_dkdev.dk_label;
    601 
    602 	part = DISKPART(dev);
    603 	pmask = (1 << part);
    604 
    605 	/*
    606 	 * If we're initialized, check to see if there are any other
    607 	 * open partitions.  If not, then it's safe to update
    608 	 * the in-core disklabel.  Only read the disklabel if it is
    609 	 * not already valid.
    610 	 */
    611 	if ((cs->sc_flags & (CCDF_INITED|CCDF_VLABEL)) == CCDF_INITED &&
    612 	    cs->sc_dkdev.dk_openmask == 0)
    613 		ccdgetdisklabel(dev);
    614 
    615 	/* Check that the partition exists. */
    616 	if (part != RAW_PART) {
    617 		if (((cs->sc_flags & CCDF_INITED) == 0) ||
    618 		    ((part >= lp->d_npartitions) ||
    619 		     (lp->d_partitions[part].p_fstype == FS_UNUSED))) {
    620 			error = ENXIO;
    621 			goto done;
    622 		}
    623 	}
    624 
    625 	/* Prevent our unit from being unconfigured while open. */
    626 	switch (fmt) {
    627 	case S_IFCHR:
    628 		cs->sc_dkdev.dk_copenmask |= pmask;
    629 		break;
    630 
    631 	case S_IFBLK:
    632 		cs->sc_dkdev.dk_bopenmask |= pmask;
    633 		break;
    634 	}
    635 	cs->sc_dkdev.dk_openmask =
    636 	    cs->sc_dkdev.dk_copenmask | cs->sc_dkdev.dk_bopenmask;
    637 
    638  done:
    639 	mutex_exit(&cs->sc_dvlock);
    640 	return (error);
    641 }
    642 
    643 /* ARGSUSED */
    644 static int
    645 ccdclose(dev_t dev, int flags, int fmt, struct lwp *l)
    646 {
    647 	int unit = ccdunit(dev);
    648 	struct ccd_softc *cs;
    649 	int part;
    650 
    651 #ifdef DEBUG
    652 	if (ccddebug & CCDB_FOLLOW)
    653 		printf("ccdclose(0x%"PRIx64", 0x%x)\n", dev, flags);
    654 #endif
    655 
    656 	if ((cs = ccdget(unit)) == NULL)
    657 		return ENXIO;
    658 
    659 	mutex_enter(&cs->sc_dvlock);
    660 
    661 	part = DISKPART(dev);
    662 
    663 	/* ...that much closer to allowing unconfiguration... */
    664 	switch (fmt) {
    665 	case S_IFCHR:
    666 		cs->sc_dkdev.dk_copenmask &= ~(1 << part);
    667 		break;
    668 
    669 	case S_IFBLK:
    670 		cs->sc_dkdev.dk_bopenmask &= ~(1 << part);
    671 		break;
    672 	}
    673 	cs->sc_dkdev.dk_openmask =
    674 	    cs->sc_dkdev.dk_copenmask | cs->sc_dkdev.dk_bopenmask;
    675 
    676 	if (cs->sc_dkdev.dk_openmask == 0) {
    677 		if ((cs->sc_flags & CCDF_KLABEL) == 0)
    678 			cs->sc_flags &= ~CCDF_VLABEL;
    679 	}
    680 
    681 	mutex_exit(&cs->sc_dvlock);
    682 	return (0);
    683 }
    684 
    685 static bool
    686 ccdbackoff(struct ccd_softc *cs)
    687 {
    688 
    689 	/* XXX Arbitrary, should be a uvm call. */
    690 	return uvmexp.free < (uvmexp.freemin >> 1) &&
    691 	    disk_isbusy(&cs->sc_dkdev);
    692 }
    693 
    694 static void
    695 ccdthread(void *cookie)
    696 {
    697 	struct ccd_softc *cs;
    698 
    699 	cs = cookie;
    700 
    701 #ifdef DEBUG
    702  	if (ccddebug & CCDB_FOLLOW)
    703  		printf("ccdthread: hello\n");
    704 #endif
    705 
    706 	mutex_enter(cs->sc_iolock);
    707 	while (__predict_true(!cs->sc_zap)) {
    708 		if (bufq_peek(cs->sc_bufq) == NULL) {
    709 			/* Nothing to do. */
    710 			cv_wait(&cs->sc_push, cs->sc_iolock);
    711 			continue;
    712 		}
    713 		if (ccdbackoff(cs)) {
    714 			/* Wait for memory to become available. */
    715 			(void)cv_timedwait(&cs->sc_push, cs->sc_iolock, 1);
    716 			continue;
    717 		}
    718 #ifdef DEBUG
    719  		if (ccddebug & CCDB_FOLLOW)
    720  			printf("ccdthread: dispatching I/O\n");
    721 #endif
    722 		ccdstart(cs);
    723 		mutex_enter(cs->sc_iolock);
    724 	}
    725 	cs->sc_thread = NULL;
    726 	mutex_exit(cs->sc_iolock);
    727 #ifdef DEBUG
    728  	if (ccddebug & CCDB_FOLLOW)
    729  		printf("ccdthread: goodbye\n");
    730 #endif
    731 	kthread_exit(0);
    732 }
    733 
    734 static void
    735 ccdstrategy(struct buf *bp)
    736 {
    737 	int unit = ccdunit(bp->b_dev);
    738 	struct ccd_softc *cs;
    739 	if ((cs = ccdget(unit)) == NULL)
    740 		return;
    741 
    742 	/* Must be open or reading label. */
    743 	KASSERT(cs->sc_dkdev.dk_openmask != 0 ||
    744 	    (cs->sc_flags & CCDF_RLABEL) != 0);
    745 
    746 	mutex_enter(cs->sc_iolock);
    747 	/* Synchronize with device init/uninit. */
    748 	if (__predict_false((cs->sc_flags & CCDF_INITED) == 0)) {
    749 		mutex_exit(cs->sc_iolock);
    750 #ifdef DEBUG
    751  		if (ccddebug & CCDB_FOLLOW)
    752  			printf("ccdstrategy: unit %d: not inited\n", unit);
    753 #endif
    754  		bp->b_error = ENXIO;
    755  		bp->b_resid = bp->b_bcount;
    756  		biodone(bp);
    757 		return;
    758 	}
    759 
    760 	/* Defer to thread if system is low on memory. */
    761 	bufq_put(cs->sc_bufq, bp);
    762 	if (__predict_false(ccdbackoff(cs))) {
    763 		mutex_exit(cs->sc_iolock);
    764 #ifdef DEBUG
    765  		if (ccddebug & CCDB_FOLLOW)
    766  			printf("ccdstrategy: holding off on I/O\n");
    767 #endif
    768 		return;
    769 	}
    770 	ccdstart(cs);
    771 }
    772 
    773 static void
    774 ccdstart(struct ccd_softc *cs)
    775 {
    776 	daddr_t blkno;
    777 	int wlabel;
    778 	struct disklabel *lp;
    779 	long bcount, rcount;
    780 	struct ccdbuf *cbp;
    781 	char *addr;
    782 	daddr_t bn;
    783 	vnode_t *vp;
    784 	buf_t *bp;
    785 
    786 	KASSERT(mutex_owned(cs->sc_iolock));
    787 
    788 	disk_busy(&cs->sc_dkdev);
    789 	bp = bufq_get(cs->sc_bufq);
    790 	KASSERT(bp != NULL);
    791 
    792 #ifdef DEBUG
    793 	if (ccddebug & CCDB_FOLLOW)
    794 		printf("ccdstart(%s, %p)\n", cs->sc_xname, bp);
    795 #endif
    796 
    797 	/* If it's a nil transfer, wake up the top half now. */
    798 	if (bp->b_bcount == 0)
    799 		goto done;
    800 
    801 	lp = cs->sc_dkdev.dk_label;
    802 
    803 	/*
    804 	 * Do bounds checking and adjust transfer.  If there's an
    805 	 * error, the bounds check will flag that for us.  Convert
    806 	 * the partition relative block number to an absolute.
    807 	 */
    808 	blkno = bp->b_blkno;
    809 	wlabel = cs->sc_flags & (CCDF_WLABEL|CCDF_LABELLING);
    810 	if (DISKPART(bp->b_dev) != RAW_PART) {
    811 		if (bounds_check_with_label(&cs->sc_dkdev, bp, wlabel) <= 0)
    812 			goto done;
    813 		blkno += lp->d_partitions[DISKPART(bp->b_dev)].p_offset;
    814 	}
    815 	mutex_exit(cs->sc_iolock);
    816 	bp->b_rawblkno = blkno;
    817 
    818 	/* Allocate the component buffers and start I/O! */
    819 	bp->b_resid = bp->b_bcount;
    820 	bn = bp->b_rawblkno;
    821 	addr = bp->b_data;
    822 	for (bcount = bp->b_bcount; bcount > 0; bcount -= rcount) {
    823 		cbp = ccdbuffer(cs, bp, bn, addr, bcount);
    824 		rcount = cbp->cb_buf.b_bcount;
    825 		bn += btodb(rcount);
    826 		addr += rcount;
    827 		vp = cbp->cb_buf.b_vp;
    828 		if ((cbp->cb_buf.b_flags & B_READ) == 0) {
    829 			mutex_enter(vp->v_interlock);
    830 			vp->v_numoutput++;
    831 			mutex_exit(vp->v_interlock);
    832 		}
    833 		(void)VOP_STRATEGY(vp, &cbp->cb_buf);
    834 	}
    835 	return;
    836 
    837  done:
    838 	disk_unbusy(&cs->sc_dkdev, 0, 0);
    839 	cv_broadcast(&cs->sc_stop);
    840 	cv_broadcast(&cs->sc_push);
    841 	mutex_exit(cs->sc_iolock);
    842 	bp->b_resid = bp->b_bcount;
    843 	biodone(bp);
    844 }
    845 
    846 /*
    847  * Build a component buffer header.
    848  */
    849 static struct ccdbuf *
    850 ccdbuffer(struct ccd_softc *cs, struct buf *bp, daddr_t bn, void *addr,
    851     long bcount)
    852 {
    853 	struct ccdcinfo *ci;
    854 	struct ccdbuf *cbp;
    855 	daddr_t cbn, cboff;
    856 	u_int64_t cbc;
    857 	int ccdisk;
    858 
    859 #ifdef DEBUG
    860 	if (ccddebug & CCDB_IO)
    861 		printf("ccdbuffer(%p, %p, %" PRId64 ", %p, %ld)\n",
    862 		       cs, bp, bn, addr, bcount);
    863 #endif
    864 	/*
    865 	 * Determine which component bn falls in.
    866 	 */
    867 	cbn = bn;
    868 	cboff = 0;
    869 
    870 	/*
    871 	 * Serially concatenated
    872 	 */
    873 	if (cs->sc_ileave == 0) {
    874 		daddr_t sblk;
    875 
    876 		sblk = 0;
    877 		for (ccdisk = 0, ci = &cs->sc_cinfo[ccdisk];
    878 		    cbn >= sblk + ci->ci_size;
    879 		    ccdisk++, ci = &cs->sc_cinfo[ccdisk])
    880 			sblk += ci->ci_size;
    881 		cbn -= sblk;
    882 	}
    883 	/*
    884 	 * Interleaved
    885 	 */
    886 	else {
    887 		struct ccdiinfo *ii;
    888 		int off;
    889 
    890 		cboff = cbn % cs->sc_ileave;
    891 		cbn /= cs->sc_ileave;
    892 		for (ii = cs->sc_itable; ii->ii_ndisk; ii++)
    893 			if (ii->ii_startblk > cbn)
    894 				break;
    895 		ii--;
    896 		off = cbn - ii->ii_startblk;
    897 		if (ii->ii_ndisk == 1) {
    898 			ccdisk = ii->ii_index[0];
    899 			cbn = ii->ii_startoff + off;
    900 		} else {
    901 			ccdisk = ii->ii_index[off % ii->ii_ndisk];
    902 			cbn = ii->ii_startoff + off / ii->ii_ndisk;
    903 		}
    904 		cbn *= cs->sc_ileave;
    905 		ci = &cs->sc_cinfo[ccdisk];
    906 	}
    907 
    908 	/*
    909 	 * Fill in the component buf structure.
    910 	 */
    911 	cbp = CCD_GETBUF();
    912 	KASSERT(cbp != NULL);
    913 	buf_init(&cbp->cb_buf);
    914 	cbp->cb_buf.b_flags = bp->b_flags;
    915 	cbp->cb_buf.b_oflags = bp->b_oflags;
    916 	cbp->cb_buf.b_cflags = bp->b_cflags;
    917 	cbp->cb_buf.b_iodone = ccdiodone;
    918 	cbp->cb_buf.b_proc = bp->b_proc;
    919 	cbp->cb_buf.b_dev = ci->ci_dev;
    920 	cbp->cb_buf.b_blkno = cbn + cboff;
    921 	cbp->cb_buf.b_data = addr;
    922 	cbp->cb_buf.b_vp = ci->ci_vp;
    923 	cbp->cb_buf.b_objlock = ci->ci_vp->v_interlock;
    924 	if (cs->sc_ileave == 0)
    925 		cbc = dbtob((u_int64_t)(ci->ci_size - cbn));
    926 	else
    927 		cbc = dbtob((u_int64_t)(cs->sc_ileave - cboff));
    928 	cbp->cb_buf.b_bcount = cbc < bcount ? cbc : bcount;
    929 
    930 	/*
    931 	 * context for ccdiodone
    932 	 */
    933 	cbp->cb_obp = bp;
    934 	cbp->cb_sc = cs;
    935 	cbp->cb_comp = ccdisk;
    936 
    937 	BIO_COPYPRIO(&cbp->cb_buf, bp);
    938 
    939 #ifdef DEBUG
    940 	if (ccddebug & CCDB_IO)
    941 		printf(" dev 0x%"PRIx64"(u%lu): cbp %p bn %" PRId64 " addr %p"
    942 		       " bcnt %d\n",
    943 		    ci->ci_dev, (unsigned long) (ci-cs->sc_cinfo), cbp,
    944 		    cbp->cb_buf.b_blkno, cbp->cb_buf.b_data,
    945 		    cbp->cb_buf.b_bcount);
    946 #endif
    947 
    948 	return (cbp);
    949 }
    950 
    951 /*
    952  * Called at interrupt time.
    953  * Mark the component as done and if all components are done,
    954  * take a ccd interrupt.
    955  */
    956 static void
    957 ccdiodone(struct buf *vbp)
    958 {
    959 	struct ccdbuf *cbp = (struct ccdbuf *) vbp;
    960 	struct buf *bp = cbp->cb_obp;
    961 	struct ccd_softc *cs = cbp->cb_sc;
    962 	int count;
    963 
    964 #ifdef DEBUG
    965 	if (ccddebug & CCDB_FOLLOW)
    966 		printf("ccdiodone(%p)\n", cbp);
    967 	if (ccddebug & CCDB_IO) {
    968 		printf("ccdiodone: bp %p bcount %d resid %d\n",
    969 		       bp, bp->b_bcount, bp->b_resid);
    970 		printf(" dev 0x%"PRIx64"(u%d), cbp %p bn %" PRId64 " addr %p"
    971 		       " bcnt %d\n",
    972 		       cbp->cb_buf.b_dev, cbp->cb_comp, cbp,
    973 		       cbp->cb_buf.b_blkno, cbp->cb_buf.b_data,
    974 		       cbp->cb_buf.b_bcount);
    975 	}
    976 #endif
    977 
    978 	if (cbp->cb_buf.b_error != 0) {
    979 		bp->b_error = cbp->cb_buf.b_error;
    980 		printf("%s: error %d on component %d\n",
    981 		       cs->sc_xname, bp->b_error, cbp->cb_comp);
    982 	}
    983 	count = cbp->cb_buf.b_bcount;
    984 	buf_destroy(&cbp->cb_buf);
    985 	CCD_PUTBUF(cbp);
    986 
    987 	/*
    988 	 * If all done, "interrupt".
    989 	 */
    990 	mutex_enter(cs->sc_iolock);
    991 	bp->b_resid -= count;
    992 	if (bp->b_resid < 0)
    993 		panic("ccdiodone: count");
    994 	if (bp->b_resid == 0) {
    995 		/*
    996 		 * Request is done for better or worse, wakeup the top half.
    997 		 */
    998 		if (bp->b_error != 0)
    999 			bp->b_resid = bp->b_bcount;
   1000 		disk_unbusy(&cs->sc_dkdev, (bp->b_bcount - bp->b_resid),
   1001 		    (bp->b_flags & B_READ));
   1002 		if (!disk_isbusy(&cs->sc_dkdev)) {
   1003 			if (bufq_peek(cs->sc_bufq) != NULL) {
   1004 				cv_broadcast(&cs->sc_push);
   1005 			}
   1006 			cv_broadcast(&cs->sc_stop);
   1007 		}
   1008 		mutex_exit(cs->sc_iolock);
   1009 		biodone(bp);
   1010 	} else
   1011 		mutex_exit(cs->sc_iolock);
   1012 }
   1013 
   1014 /* ARGSUSED */
   1015 static int
   1016 ccdread(dev_t dev, struct uio *uio, int flags)
   1017 {
   1018 	int unit = ccdunit(dev);
   1019 	struct ccd_softc *cs;
   1020 
   1021 #ifdef DEBUG
   1022 	if (ccddebug & CCDB_FOLLOW)
   1023 		printf("ccdread(0x%"PRIx64", %p)\n", dev, uio);
   1024 #endif
   1025 	if ((cs = ccdget(unit)) == NULL)
   1026 		return 0;
   1027 
   1028 	/* Unlocked advisory check, ccdstrategy check is synchronous. */
   1029 	if ((cs->sc_flags & CCDF_INITED) == 0)
   1030 		return (ENXIO);
   1031 
   1032 	return (physio(ccdstrategy, NULL, dev, B_READ, minphys, uio));
   1033 }
   1034 
   1035 /* ARGSUSED */
   1036 static int
   1037 ccdwrite(dev_t dev, struct uio *uio, int flags)
   1038 {
   1039 	int unit = ccdunit(dev);
   1040 	struct ccd_softc *cs;
   1041 
   1042 #ifdef DEBUG
   1043 	if (ccddebug & CCDB_FOLLOW)
   1044 		printf("ccdwrite(0x%"PRIx64", %p)\n", dev, uio);
   1045 #endif
   1046 	if ((cs = ccdget(unit)) == NULL)
   1047 		return ENOENT;
   1048 
   1049 	/* Unlocked advisory check, ccdstrategy check is synchronous. */
   1050 	if ((cs->sc_flags & CCDF_INITED) == 0)
   1051 		return (ENXIO);
   1052 
   1053 	return (physio(ccdstrategy, NULL, dev, B_WRITE, minphys, uio));
   1054 }
   1055 
   1056 static int
   1057 ccdioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
   1058 {
   1059 	int unit = ccdunit(dev);
   1060 	int i, j, lookedup = 0, error = 0;
   1061 	int part, pmask;
   1062 	struct ccd_softc *cs;
   1063 	struct ccd_ioctl *ccio = (struct ccd_ioctl *)data;
   1064 	kauth_cred_t uc;
   1065 	char **cpp;
   1066 	struct pathbuf *pb;
   1067 	struct vnode **vpp;
   1068 #ifdef __HAVE_OLD_DISKLABEL
   1069 	struct disklabel newlabel;
   1070 #endif
   1071 
   1072 	if ((cs = ccdget(unit)) == NULL)
   1073 		return ENOENT;
   1074 	uc = kauth_cred_get();
   1075 
   1076 /*
   1077  * Compat code must not be called if on a platform where
   1078  * sizeof (size_t) == sizeof (uint64_t) as CCDIOCSET will
   1079  * be the same as CCDIOCSET_60
   1080  */
   1081 #if defined(COMPAT_60) && !defined(_LP64)
   1082 	switch (cmd) {
   1083 	case CCDIOCSET_60: {
   1084 		struct ccd_ioctl ccionew;
   1085        		struct ccd_ioctl_60 *ccio60 =
   1086        		    (struct ccd_ioctl_60 *)data;
   1087 		ccionew.ccio_disks = ccio->ccio_disks;
   1088 		ccionew.ccio_ndisks = ccio->ccio_ndisks;
   1089 		ccionew.ccio_ileave = ccio->ccio_ileave;
   1090 		ccionew.ccio_flags = ccio->ccio_flags;
   1091 		ccionew.ccio_unit = ccio->ccio_unit;
   1092 		error = ccdioctl(dev, CCDIOCSET, &ccionew, flag, l);
   1093 		if (!error) {
   1094 			/* Copy data back, adjust types if necessary */
   1095 			ccio60->ccio_disks = ccionew.ccio_disks;
   1096 			ccio60->ccio_ndisks = ccionew.ccio_ndisks;
   1097 			ccio60->ccio_ileave = ccionew.ccio_ileave;
   1098 			ccio60->ccio_flags = ccionew.ccio_flags;
   1099 			ccio60->ccio_unit = ccionew.ccio_unit;
   1100 			ccio60->ccio_size = (size_t)ccionew.ccio_size;
   1101 		}
   1102 		return error;
   1103 		}
   1104 		break;
   1105 
   1106 	case CCDIOCCLR_60:
   1107 		/*
   1108 		 * ccio_size member not used, so existing struct OK
   1109 		 * drop through to existing non-compat version
   1110 		 */
   1111 		cmd = CCDIOCCLR;
   1112 		break;
   1113 	}
   1114 #endif /* COMPAT_60 && !_LP64*/
   1115 
   1116 	/* Must be open for writes for these commands... */
   1117 	switch (cmd) {
   1118 	case CCDIOCSET:
   1119 	case CCDIOCCLR:
   1120 	case DIOCSDINFO:
   1121 	case DIOCWDINFO:
   1122 #ifdef __HAVE_OLD_DISKLABEL
   1123 	case ODIOCSDINFO:
   1124 	case ODIOCWDINFO:
   1125 #endif
   1126 	case DIOCKLABEL:
   1127 	case DIOCWLABEL:
   1128 		if ((flag & FWRITE) == 0)
   1129 			return (EBADF);
   1130 	}
   1131 
   1132 	mutex_enter(&cs->sc_dvlock);
   1133 
   1134 	/* Must be initialized for these... */
   1135 	switch (cmd) {
   1136 	case CCDIOCCLR:
   1137 	case DIOCGDINFO:
   1138 	case DIOCCACHESYNC:
   1139 	case DIOCSDINFO:
   1140 	case DIOCWDINFO:
   1141 	case DIOCGPART:
   1142 	case DIOCWLABEL:
   1143 	case DIOCKLABEL:
   1144 	case DIOCGDEFLABEL:
   1145 #ifdef __HAVE_OLD_DISKLABEL
   1146 	case ODIOCGDINFO:
   1147 	case ODIOCSDINFO:
   1148 	case ODIOCWDINFO:
   1149 	case ODIOCGDEFLABEL:
   1150 #endif
   1151 		if ((cs->sc_flags & CCDF_INITED) == 0) {
   1152 			error = ENXIO;
   1153 			goto out;
   1154 		}
   1155 	}
   1156 
   1157 	switch (cmd) {
   1158 	case CCDIOCSET:
   1159 		if (cs->sc_flags & CCDF_INITED) {
   1160 			error = EBUSY;
   1161 			goto out;
   1162 		}
   1163 
   1164 		/* Validate the flags. */
   1165 		if ((ccio->ccio_flags & CCDF_USERMASK) != ccio->ccio_flags) {
   1166 			error = EINVAL;
   1167 			goto out;
   1168 		}
   1169 
   1170 		if (ccio->ccio_ndisks > CCD_MAXNDISKS ||
   1171 		    ccio->ccio_ndisks == 0) {
   1172 			error = EINVAL;
   1173 			goto out;
   1174 		}
   1175 
   1176 		/* Fill in some important bits. */
   1177 		cs->sc_ileave = ccio->ccio_ileave;
   1178 		cs->sc_nccdisks = ccio->ccio_ndisks;
   1179 		cs->sc_flags = ccio->ccio_flags & CCDF_USERMASK;
   1180 
   1181 		/*
   1182 		 * Allocate space for and copy in the array of
   1183 		 * component pathnames and device numbers.
   1184 		 */
   1185 		cpp = kmem_alloc(ccio->ccio_ndisks * sizeof(*cpp), KM_SLEEP);
   1186 		vpp = kmem_alloc(ccio->ccio_ndisks * sizeof(*vpp), KM_SLEEP);
   1187 		error = copyin(ccio->ccio_disks, cpp,
   1188 		    ccio->ccio_ndisks * sizeof(*cpp));
   1189 		if (error) {
   1190 			kmem_free(vpp, ccio->ccio_ndisks * sizeof(*vpp));
   1191 			kmem_free(cpp, ccio->ccio_ndisks * sizeof(*cpp));
   1192 			goto out;
   1193 		}
   1194 
   1195 #ifdef DEBUG
   1196 		if (ccddebug & CCDB_INIT)
   1197 			for (i = 0; i < ccio->ccio_ndisks; ++i)
   1198 				printf("ccdioctl: component %d: %p\n",
   1199 				    i, cpp[i]);
   1200 #endif
   1201 
   1202 		for (i = 0; i < ccio->ccio_ndisks; ++i) {
   1203 #ifdef DEBUG
   1204 			if (ccddebug & CCDB_INIT)
   1205 				printf("ccdioctl: lookedup = %d\n", lookedup);
   1206 #endif
   1207 			error = pathbuf_copyin(cpp[i], &pb);
   1208 			if (error == 0) {
   1209 				error = dk_lookup(pb, l, &vpp[i]);
   1210 			}
   1211 			pathbuf_destroy(pb);
   1212 			if (error != 0) {
   1213 				for (j = 0; j < lookedup; ++j)
   1214 					(void)vn_close(vpp[j], FREAD|FWRITE,
   1215 					    uc);
   1216 				kmem_free(vpp, ccio->ccio_ndisks *
   1217 				    sizeof(*vpp));
   1218 				kmem_free(cpp, ccio->ccio_ndisks *
   1219 				    sizeof(*cpp));
   1220 				goto out;
   1221 			}
   1222 			++lookedup;
   1223 		}
   1224 
   1225 		/* Attach the disk. */
   1226 		disk_attach(&cs->sc_dkdev);
   1227 		bufq_alloc(&cs->sc_bufq, "fcfs", 0);
   1228 
   1229 		/*
   1230 		 * Initialize the ccd.  Fills in the softc for us.
   1231 		 */
   1232 		if ((error = ccdinit(cs, cpp, vpp, l)) != 0) {
   1233 			for (j = 0; j < lookedup; ++j)
   1234 				(void)vn_close(vpp[j], FREAD|FWRITE,
   1235 				    uc);
   1236 			kmem_free(vpp, ccio->ccio_ndisks * sizeof(*vpp));
   1237 			kmem_free(cpp, ccio->ccio_ndisks * sizeof(*cpp));
   1238 			disk_detach(&cs->sc_dkdev);
   1239 			bufq_free(cs->sc_bufq);
   1240 			goto out;
   1241 		}
   1242 
   1243 		/* We can free the temporary variables now. */
   1244 		kmem_free(vpp, ccio->ccio_ndisks * sizeof(*vpp));
   1245 		kmem_free(cpp, ccio->ccio_ndisks * sizeof(*cpp));
   1246 
   1247 		/*
   1248 		 * The ccd has been successfully initialized, so
   1249 		 * we can place it into the array.  Don't try to
   1250 		 * read the disklabel until the disk has been attached,
   1251 		 * because space for the disklabel is allocated
   1252 		 * in disk_attach();
   1253 		 */
   1254 		ccio->ccio_unit = unit;
   1255 		ccio->ccio_size = cs->sc_size;
   1256 
   1257 		/* Try and read the disklabel. */
   1258 		ccdgetdisklabel(dev);
   1259 		break;
   1260 
   1261 	case CCDIOCCLR:
   1262 		/*
   1263 		 * Don't unconfigure if any other partitions are open
   1264 		 * or if both the character and block flavors of this
   1265 		 * partition are open.
   1266 		 */
   1267 		part = DISKPART(dev);
   1268 		pmask = (1 << part);
   1269 		if ((cs->sc_dkdev.dk_openmask & ~pmask) ||
   1270 		    ((cs->sc_dkdev.dk_bopenmask & pmask) &&
   1271 		    (cs->sc_dkdev.dk_copenmask & pmask))) {
   1272 			error = EBUSY;
   1273 			goto out;
   1274 		}
   1275 
   1276 		/* Stop new I/O, wait for in-flight I/O to complete. */
   1277 		mutex_enter(cs->sc_iolock);
   1278 		cs->sc_flags &= ~(CCDF_INITED|CCDF_VLABEL);
   1279 		cs->sc_zap = true;
   1280 		while (disk_isbusy(&cs->sc_dkdev) ||
   1281 		    bufq_peek(cs->sc_bufq) != NULL ||
   1282 		    cs->sc_thread != NULL) {
   1283 			cv_broadcast(&cs->sc_push);
   1284 			(void)cv_timedwait(&cs->sc_stop, cs->sc_iolock, hz);
   1285 		}
   1286 		mutex_exit(cs->sc_iolock);
   1287 
   1288 		/*
   1289 		 * Free ccd_softc information and clear entry.
   1290 		 */
   1291 
   1292 		/* Close the components and free their pathnames. */
   1293 		for (i = 0; i < cs->sc_nccdisks; ++i) {
   1294 			/*
   1295 			 * XXX: this close could potentially fail and
   1296 			 * cause Bad Things.  Maybe we need to force
   1297 			 * the close to happen?
   1298 			 */
   1299 #ifdef DEBUG
   1300 			if (ccddebug & CCDB_VNODE)
   1301 				vprint("CCDIOCCLR: vnode info",
   1302 				    cs->sc_cinfo[i].ci_vp);
   1303 #endif
   1304 			(void)vn_close(cs->sc_cinfo[i].ci_vp, FREAD|FWRITE,
   1305 			    uc);
   1306 			kmem_free(cs->sc_cinfo[i].ci_path,
   1307 			    cs->sc_cinfo[i].ci_pathlen);
   1308 		}
   1309 
   1310 		/* Free interleave index. */
   1311 		for (i = 0; cs->sc_itable[i].ii_ndisk; ++i) {
   1312 			kmem_free(cs->sc_itable[i].ii_index,
   1313 			    cs->sc_itable[i].ii_indexsz);
   1314 		}
   1315 
   1316 		/* Free component info and interleave table. */
   1317 		kmem_free(cs->sc_cinfo, cs->sc_nccdisks *
   1318 		    sizeof(struct ccdcinfo));
   1319 		kmem_free(cs->sc_itable, (cs->sc_nccdisks + 1) *
   1320 		    sizeof(struct ccdiinfo));
   1321 
   1322 		aprint_normal("%s: detached\n", cs->sc_xname);
   1323 
   1324 		/* Detach the disk. */
   1325 		disk_detach(&cs->sc_dkdev);
   1326 		bufq_free(cs->sc_bufq);
   1327 		ccdput(cs);
   1328 		/* Don't break, otherwise cs is read again. */
   1329 		return 0;
   1330 
   1331 	case DIOCGDINFO:
   1332 		*(struct disklabel *)data = *(cs->sc_dkdev.dk_label);
   1333 		break;
   1334 
   1335 #ifdef __HAVE_OLD_DISKLABEL
   1336 	case ODIOCGDINFO:
   1337 		newlabel = *(cs->sc_dkdev.dk_label);
   1338 		if (newlabel.d_npartitions > OLDMAXPARTITIONS)
   1339 			return ENOTTY;
   1340 		memcpy(data, &newlabel, sizeof (struct olddisklabel));
   1341 		break;
   1342 #endif
   1343 
   1344 	case DIOCGPART:
   1345 		((struct partinfo *)data)->disklab = cs->sc_dkdev.dk_label;
   1346 		((struct partinfo *)data)->part =
   1347 		    &cs->sc_dkdev.dk_label->d_partitions[DISKPART(dev)];
   1348 		break;
   1349 
   1350 	case DIOCCACHESYNC:
   1351 		/*
   1352 		 * XXX Do we really need to care about having a writable
   1353 		 * file descriptor here?
   1354 		 */
   1355 		if ((flag & FWRITE) == 0)
   1356 			return (EBADF);
   1357 
   1358 		/*
   1359 		 * We pass this call down to all components and report
   1360 		 * the first error we encounter.
   1361 		 */
   1362 		for (error = 0, i = 0; i < cs->sc_nccdisks; i++) {
   1363 			j = VOP_IOCTL(cs->sc_cinfo[i].ci_vp, cmd, data,
   1364 				      flag, uc);
   1365 			if (j != 0 && error == 0)
   1366 				error = j;
   1367 		}
   1368 		break;
   1369 
   1370 	case DIOCWDINFO:
   1371 	case DIOCSDINFO:
   1372 #ifdef __HAVE_OLD_DISKLABEL
   1373 	case ODIOCWDINFO:
   1374 	case ODIOCSDINFO:
   1375 #endif
   1376 	{
   1377 		struct disklabel *lp;
   1378 #ifdef __HAVE_OLD_DISKLABEL
   1379 		if (cmd == ODIOCSDINFO || cmd == ODIOCWDINFO) {
   1380 			memset(&newlabel, 0, sizeof newlabel);
   1381 			memcpy(&newlabel, data, sizeof (struct olddisklabel));
   1382 			lp = &newlabel;
   1383 		} else
   1384 #endif
   1385 		lp = (struct disklabel *)data;
   1386 
   1387 		cs->sc_flags |= CCDF_LABELLING;
   1388 
   1389 		error = setdisklabel(cs->sc_dkdev.dk_label,
   1390 		    lp, 0, cs->sc_dkdev.dk_cpulabel);
   1391 		if (error == 0) {
   1392 			if (cmd == DIOCWDINFO
   1393 #ifdef __HAVE_OLD_DISKLABEL
   1394 			    || cmd == ODIOCWDINFO
   1395 #endif
   1396 			   )
   1397 				error = writedisklabel(CCDLABELDEV(dev),
   1398 				    ccdstrategy, cs->sc_dkdev.dk_label,
   1399 				    cs->sc_dkdev.dk_cpulabel);
   1400 		}
   1401 
   1402 		cs->sc_flags &= ~CCDF_LABELLING;
   1403 		break;
   1404 	}
   1405 
   1406 	case DIOCKLABEL:
   1407 		if (*(int *)data != 0)
   1408 			cs->sc_flags |= CCDF_KLABEL;
   1409 		else
   1410 			cs->sc_flags &= ~CCDF_KLABEL;
   1411 		break;
   1412 
   1413 	case DIOCWLABEL:
   1414 		if (*(int *)data != 0)
   1415 			cs->sc_flags |= CCDF_WLABEL;
   1416 		else
   1417 			cs->sc_flags &= ~CCDF_WLABEL;
   1418 		break;
   1419 
   1420 	case DIOCGDEFLABEL:
   1421 		ccdgetdefaultlabel(cs, (struct disklabel *)data);
   1422 		break;
   1423 
   1424 #ifdef __HAVE_OLD_DISKLABEL
   1425 	case ODIOCGDEFLABEL:
   1426 		ccdgetdefaultlabel(cs, &newlabel);
   1427 		if (newlabel.d_npartitions > OLDMAXPARTITIONS)
   1428 			return ENOTTY;
   1429 		memcpy(data, &newlabel, sizeof (struct olddisklabel));
   1430 		break;
   1431 #endif
   1432 
   1433 	default:
   1434 		error = ENOTTY;
   1435 	}
   1436 
   1437  out:
   1438 	mutex_exit(&cs->sc_dvlock);
   1439 	return (error);
   1440 }
   1441 
   1442 static int
   1443 ccdsize(dev_t dev)
   1444 {
   1445 	struct ccd_softc *cs;
   1446 	struct disklabel *lp;
   1447 	int part, unit, omask, size;
   1448 
   1449 	unit = ccdunit(dev);
   1450 	if ((cs = ccdget(unit)) == NULL)
   1451 		return -1;
   1452 
   1453 	if ((cs->sc_flags & CCDF_INITED) == 0)
   1454 		return (-1);
   1455 
   1456 	part = DISKPART(dev);
   1457 	omask = cs->sc_dkdev.dk_openmask & (1 << part);
   1458 	lp = cs->sc_dkdev.dk_label;
   1459 
   1460 	if (omask == 0 && ccdopen(dev, 0, S_IFBLK, curlwp))
   1461 		return (-1);
   1462 
   1463 	if (lp->d_partitions[part].p_fstype != FS_SWAP)
   1464 		size = -1;
   1465 	else
   1466 		size = lp->d_partitions[part].p_size *
   1467 		    (lp->d_secsize / DEV_BSIZE);
   1468 
   1469 	if (omask == 0 && ccdclose(dev, 0, S_IFBLK, curlwp))
   1470 		return (-1);
   1471 
   1472 	return (size);
   1473 }
   1474 
   1475 static void
   1476 ccdgetdefaultlabel(struct ccd_softc *cs, struct disklabel *lp)
   1477 {
   1478 	struct ccdgeom *ccg = &cs->sc_geom;
   1479 
   1480 	memset(lp, 0, sizeof(*lp));
   1481 
   1482 	lp->d_secperunit = cs->sc_size;
   1483 	lp->d_secsize = ccg->ccg_secsize;
   1484 	lp->d_nsectors = ccg->ccg_nsectors;
   1485 	lp->d_ntracks = ccg->ccg_ntracks;
   1486 	lp->d_ncylinders = ccg->ccg_ncylinders;
   1487 	lp->d_secpercyl = lp->d_ntracks * lp->d_nsectors;
   1488 
   1489 	strncpy(lp->d_typename, "ccd", sizeof(lp->d_typename));
   1490 	lp->d_type = DTYPE_CCD;
   1491 	strncpy(lp->d_packname, "fictitious", sizeof(lp->d_packname));
   1492 	lp->d_rpm = 3600;
   1493 	lp->d_interleave = 1;
   1494 	lp->d_flags = 0;
   1495 
   1496 	lp->d_partitions[RAW_PART].p_offset = 0;
   1497 	lp->d_partitions[RAW_PART].p_size = cs->sc_size;
   1498 	lp->d_partitions[RAW_PART].p_fstype = FS_UNUSED;
   1499 	lp->d_npartitions = RAW_PART + 1;
   1500 
   1501 	lp->d_magic = DISKMAGIC;
   1502 	lp->d_magic2 = DISKMAGIC;
   1503 	lp->d_checksum = dkcksum(cs->sc_dkdev.dk_label);
   1504 }
   1505 
   1506 /*
   1507  * Read the disklabel from the ccd.  If one is not present, fake one
   1508  * up.
   1509  */
   1510 static void
   1511 ccdgetdisklabel(dev_t dev)
   1512 {
   1513 	int unit = ccdunit(dev);
   1514 	struct ccd_softc *cs;
   1515 	const char *errstring;
   1516 	struct disklabel *lp;
   1517 	struct cpu_disklabel *clp;
   1518 
   1519 	if ((cs = ccdget(unit)) == NULL)
   1520 		return;
   1521 	lp = cs->sc_dkdev.dk_label;
   1522 	clp = cs->sc_dkdev.dk_cpulabel;
   1523 	KASSERT(mutex_owned(&cs->sc_dvlock));
   1524 
   1525 	memset(clp, 0, sizeof(*clp));
   1526 
   1527 	ccdgetdefaultlabel(cs, lp);
   1528 
   1529 	/*
   1530 	 * Call the generic disklabel extraction routine.
   1531 	 */
   1532 	cs->sc_flags |= CCDF_RLABEL;
   1533 	if ((cs->sc_flags & CCDF_NOLABEL) != 0)
   1534 		errstring = "CCDF_NOLABEL set; ignoring on-disk label";
   1535 	else
   1536 		errstring = readdisklabel(CCDLABELDEV(dev), ccdstrategy,
   1537 		    cs->sc_dkdev.dk_label, cs->sc_dkdev.dk_cpulabel);
   1538 	if (errstring)
   1539 		ccdmakedisklabel(cs);
   1540 	else {
   1541 		int i;
   1542 		struct partition *pp;
   1543 
   1544 		/*
   1545 		 * Sanity check whether the found disklabel is valid.
   1546 		 *
   1547 		 * This is necessary since total size of ccd may vary
   1548 		 * when an interleave is changed even though exactly
   1549 		 * same componets are used, and old disklabel may used
   1550 		 * if that is found.
   1551 		 */
   1552 		if (lp->d_secperunit != cs->sc_size)
   1553 			printf("WARNING: %s: "
   1554 			    "total sector size in disklabel (%ju) != "
   1555 			    "the size of ccd (%ju)\n", cs->sc_xname,
   1556 			    (uintmax_t)lp->d_secperunit,
   1557 			    (uintmax_t)cs->sc_size);
   1558 		for (i = 0; i < lp->d_npartitions; i++) {
   1559 			pp = &lp->d_partitions[i];
   1560 			if (pp->p_offset + pp->p_size > cs->sc_size)
   1561 				printf("WARNING: %s: end of partition `%c' "
   1562 				    "exceeds the size of ccd (%ju)\n",
   1563 				    cs->sc_xname, 'a' + i, (uintmax_t)cs->sc_size);
   1564 		}
   1565 	}
   1566 
   1567 #ifdef DEBUG
   1568 	/* It's actually extremely common to have unlabeled ccds. */
   1569 	if (ccddebug & CCDB_LABEL)
   1570 		if (errstring != NULL)
   1571 			printf("%s: %s\n", cs->sc_xname, errstring);
   1572 #endif
   1573 
   1574 	/* In-core label now valid. */
   1575 	cs->sc_flags = (cs->sc_flags | CCDF_VLABEL) & ~CCDF_RLABEL;
   1576 }
   1577 
   1578 /*
   1579  * Take care of things one might want to take care of in the event
   1580  * that a disklabel isn't present.
   1581  */
   1582 static void
   1583 ccdmakedisklabel(struct ccd_softc *cs)
   1584 {
   1585 	struct disklabel *lp = cs->sc_dkdev.dk_label;
   1586 
   1587 	/*
   1588 	 * For historical reasons, if there's no disklabel present
   1589 	 * the raw partition must be marked FS_BSDFFS.
   1590 	 */
   1591 	lp->d_partitions[RAW_PART].p_fstype = FS_BSDFFS;
   1592 
   1593 	strncpy(lp->d_packname, "default label", sizeof(lp->d_packname));
   1594 
   1595 	lp->d_checksum = dkcksum(lp);
   1596 }
   1597 
   1598 #ifdef DEBUG
   1599 static void
   1600 printiinfo(struct ccdiinfo *ii)
   1601 {
   1602 	int ix, i;
   1603 
   1604 	for (ix = 0; ii->ii_ndisk; ix++, ii++) {
   1605 		printf(" itab[%d]: #dk %d sblk %" PRId64 " soff %" PRId64,
   1606 		    ix, ii->ii_ndisk, ii->ii_startblk, ii->ii_startoff);
   1607 		for (i = 0; i < ii->ii_ndisk; i++)
   1608 			printf(" %d", ii->ii_index[i]);
   1609 		printf("\n");
   1610 	}
   1611 }
   1612 #endif
   1613 
   1614 MODULE(MODULE_CLASS_DRIVER, ccd, "dk_subr");
   1615 
   1616 static int
   1617 ccd_modcmd(modcmd_t cmd, void *arg)
   1618 {
   1619 	int error = 0;
   1620 #ifdef _MODULE
   1621 	int bmajor = -1, cmajor = -1;
   1622 #endif
   1623 
   1624 
   1625 	switch (cmd) {
   1626 	case MODULE_CMD_INIT:
   1627 #ifdef _MODULE
   1628 		ccdattach(4);
   1629 
   1630 		return devsw_attach("ccd", &ccd_bdevsw, &bmajor,
   1631 		    &ccd_cdevsw, &cmajor);
   1632 #endif
   1633 		break;
   1634 
   1635 	case MODULE_CMD_FINI:
   1636 #ifdef _MODULE
   1637 		return devsw_detach(&ccd_bdevsw, &ccd_cdevsw);
   1638 #endif
   1639 		break;
   1640 
   1641 	case MODULE_CMD_STAT:
   1642 		return ENOTTY;
   1643 
   1644 	default:
   1645 		return ENOTTY;
   1646 	}
   1647 
   1648 	return error;
   1649 }
   1650 
   1651 static int
   1652 ccd_units_sysctl(SYSCTLFN_ARGS)
   1653 {
   1654 	struct sysctlnode node;
   1655 	struct ccd_softc *sc;
   1656 	int error, i, nccd, *units;
   1657 	size_t size;
   1658 
   1659 	nccd = 0;
   1660 	mutex_enter(&ccd_lock);
   1661 	LIST_FOREACH(sc, &ccds, sc_link)
   1662 		nccd++;
   1663 	mutex_exit(&ccd_lock);
   1664 
   1665 	if (nccd != 0) {
   1666 		size = nccd * sizeof(*units);
   1667 		units = kmem_zalloc(size, KM_SLEEP);
   1668 		if (units == NULL)
   1669 			return ENOMEM;
   1670 
   1671 		i = 0;
   1672 		mutex_enter(&ccd_lock);
   1673 		LIST_FOREACH(sc, &ccds, sc_link) {
   1674 			if (i >= nccd)
   1675 				break;
   1676 			units[i] = sc->sc_unit;
   1677 		}
   1678 		mutex_exit(&ccd_lock);
   1679 	} else {
   1680 		units = NULL;
   1681 		size = 0;
   1682 	}
   1683 
   1684 	node = *rnode;
   1685 	node.sysctl_data = units;
   1686 	node.sysctl_size = size;
   1687 
   1688 	error = sysctl_lookup(SYSCTLFN_CALL(&node));
   1689 	if (units)
   1690 		kmem_free(units, size);
   1691 	return error;
   1692 }
   1693 
   1694 static int
   1695 ccd_info_sysctl(SYSCTLFN_ARGS)
   1696 {
   1697 	struct sysctlnode node;
   1698 	struct ccddiskinfo ccd;
   1699 	struct ccd_softc *sc;
   1700 	int unit;
   1701 
   1702 	if (newp == NULL || newlen != sizeof(int))
   1703 		return EINVAL;
   1704 
   1705 	unit = *(const int *)newp;
   1706 	newp = NULL;
   1707 	newlen = 0;
   1708 	ccd.ccd_ndisks = ~0;
   1709 	mutex_enter(&ccd_lock);
   1710 	LIST_FOREACH(sc, &ccds, sc_link) {
   1711 		if (sc->sc_unit == unit) {
   1712 			ccd.ccd_ileave = sc->sc_ileave;
   1713 			ccd.ccd_size = sc->sc_size;
   1714 			ccd.ccd_ndisks = sc->sc_nccdisks;
   1715 			ccd.ccd_flags = sc->sc_flags;
   1716 			break;
   1717 		}
   1718 	}
   1719 	mutex_exit(&ccd_lock);
   1720 
   1721 	if (ccd.ccd_ndisks == ~0)
   1722 		return ENOENT;
   1723 
   1724 	node = *rnode;
   1725 	node.sysctl_data = &ccd;
   1726 	node.sysctl_size = sizeof(ccd);
   1727 
   1728 	return sysctl_lookup(SYSCTLFN_CALL(&node));
   1729 }
   1730 
   1731 static int
   1732 ccd_components_sysctl(SYSCTLFN_ARGS)
   1733 {
   1734 	struct sysctlnode node;
   1735 	int error, unit;
   1736 	size_t size;
   1737 	char *names, *p, *ep;
   1738 	struct ccd_softc *sc;
   1739 
   1740 	if (newp == NULL || newlen != sizeof(int))
   1741 		return EINVAL;
   1742 
   1743 	size = 0;
   1744 	unit = *(const int *)newp;
   1745 	newp = NULL;
   1746 	newlen = 0;
   1747 	mutex_enter(&ccd_lock);
   1748 	LIST_FOREACH(sc, &ccds, sc_link)
   1749 		if (sc->sc_unit == unit) {
   1750 			for (size_t i = 0; i < sc->sc_nccdisks; i++)
   1751 				size += strlen(sc->sc_cinfo[i].ci_path) + 1;
   1752 			break;
   1753 		}
   1754 	mutex_exit(&ccd_lock);
   1755 
   1756 	if (size == 0)
   1757 		return ENOENT;
   1758 	names = kmem_zalloc(size, KM_SLEEP);
   1759 	if (names == NULL)
   1760 		return ENOMEM;
   1761 
   1762 	p = names;
   1763 	ep = names + size;
   1764 	mutex_enter(&ccd_lock);
   1765 	LIST_FOREACH(sc, &ccds, sc_link)
   1766 		if (sc->sc_unit == unit) {
   1767 			for (size_t i = 0; i < sc->sc_nccdisks; i++) {
   1768 				char *d = sc->sc_cinfo[i].ci_path;
   1769 				while (p < ep && (*p++ = *d++) != '\0')
   1770 					continue;
   1771 			}
   1772 			break;
   1773 		}
   1774 	mutex_exit(&ccd_lock);
   1775 
   1776 	node = *rnode;
   1777 	node.sysctl_data = names;
   1778 	node.sysctl_size = ep - names;
   1779 
   1780 	error = sysctl_lookup(SYSCTLFN_CALL(&node));
   1781 	kmem_free(names, size);
   1782 	return error;
   1783 }
   1784 
   1785 SYSCTL_SETUP(sysctl_kern_ccd_setup, "sysctl kern.ccd subtree setup")
   1786 {
   1787 	const struct sysctlnode *node = NULL;
   1788 
   1789 	sysctl_createv(clog, 0, NULL, &node,
   1790 	    CTLFLAG_PERMANENT,
   1791 	    CTLTYPE_NODE, "ccd",
   1792 	    SYSCTL_DESCR("ConCatenated Disk state"),
   1793 	    NULL, 0, NULL, 0,
   1794 	    CTL_KERN, CTL_CREATE, CTL_EOL);
   1795 
   1796 	if (node == NULL)
   1797 		return;
   1798 
   1799 	sysctl_createv(clog, 0, &node, NULL,
   1800 	    CTLFLAG_PERMANENT | CTLFLAG_READONLY,
   1801 	    CTLTYPE_STRUCT, "units",
   1802 	    SYSCTL_DESCR("List of ccd unit numbers"),
   1803 	    ccd_units_sysctl, 0, NULL, 0,
   1804 	    CTL_CREATE, CTL_EOL);
   1805 	sysctl_createv(clog, 0, &node, NULL,
   1806 	    CTLFLAG_PERMANENT | CTLFLAG_READWRITE,
   1807 	    CTLTYPE_STRUCT, "info",
   1808 	    SYSCTL_DESCR("Information about a CCD unit"),
   1809 	    ccd_info_sysctl, 0, NULL, 0,
   1810 	    CTL_CREATE, CTL_EOL);
   1811 	sysctl_createv(clog, 0, &node, NULL,
   1812 	    CTLFLAG_PERMANENT | CTLFLAG_READWRITE,
   1813 	    CTLTYPE_STRUCT, "components",
   1814 	    SYSCTL_DESCR("Information about CCD components"),
   1815 	    ccd_components_sysctl, 0, NULL, 0,
   1816 	    CTL_CREATE, CTL_EOL);
   1817 }
   1818