xref: /freebsd/sys/geom/geom_ccd.c (revision ee2ea5ceafed78a5bd9810beb9e3ca927180c226)
1 /* $FreeBSD$ */
2 
3 /*	$NetBSD: ccd.c,v 1.22 1995/12/08 19:13:26 thorpej Exp $	*/
4 
5 /*
6  * Copyright (c) 1995 Jason R. Thorpe.
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. All advertising materials mentioning features or use of this software
18  *    must display the following acknowledgement:
19  *	This product includes software developed for the NetBSD Project
20  *	by Jason R. Thorpe.
21  * 4. The name of the author may not be used to endorse or promote products
22  *    derived from this software without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
25  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
26  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
27  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
28  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
29  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
30  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
31  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
32  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  */
36 
37 /*
38  * Copyright (c) 1988 University of Utah.
39  * Copyright (c) 1990, 1993
40  *	The Regents of the University of California.  All rights reserved.
41  *
42  * This code is derived from software contributed to Berkeley by
43  * the Systems Programming Group of the University of Utah Computer
44  * Science Department.
45  *
46  * Redistribution and use in source and binary forms, with or without
47  * modification, are permitted provided that the following conditions
48  * are met:
49  * 1. Redistributions of source code must retain the above copyright
50  *    notice, this list of conditions and the following disclaimer.
51  * 2. Redistributions in binary form must reproduce the above copyright
52  *    notice, this list of conditions and the following disclaimer in the
53  *    documentation and/or other materials provided with the distribution.
54  * 3. All advertising materials mentioning features or use of this software
55  *    must display the following acknowledgement:
56  *	This product includes software developed by the University of
57  *	California, Berkeley and its contributors.
58  * 4. Neither the name of the University nor the names of its contributors
59  *    may be used to endorse or promote products derived from this software
60  *    without specific prior written permission.
61  *
62  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
63  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
64  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
65  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
66  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
67  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
68  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
69  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
70  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
71  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
72  * SUCH DAMAGE.
73  *
74  * from: Utah $Hdr: cd.c 1.6 90/11/28$
75  *
76  *	@(#)cd.c	8.2 (Berkeley) 11/16/93
77  */
78 
79 /*
80  * "Concatenated" disk driver.
81  *
82  * Dynamic configuration and disklabel support by:
83  *	Jason R. Thorpe <thorpej@nas.nasa.gov>
84  *	Numerical Aerodynamic Simulation Facility
85  *	Mail Stop 258-6
86  *	NASA Ames Research Center
87  *	Moffett Field, CA 94035
88  */
89 
90 #include <sys/param.h>
91 #include <sys/systm.h>
92 #include <sys/kernel.h>
93 #include <sys/module.h>
94 #include <sys/proc.h>
95 #include <sys/bio.h>
96 #include <sys/malloc.h>
97 #include <sys/namei.h>
98 #include <sys/conf.h>
99 #include <sys/stat.h>
100 #include <sys/sysctl.h>
101 #include <sys/disk.h>
102 #include <ufs/ffs/fs.h>
103 #include <sys/devicestat.h>
104 #include <sys/fcntl.h>
105 #include <sys/vnode.h>
106 
107 #include <sys/ccdvar.h>
108 
109 MALLOC_DEFINE(M_CCD, "CCD driver", "Concatenated Disk driver");
110 
111 #if defined(CCDDEBUG) && !defined(DEBUG)
112 #define DEBUG
113 #endif
114 
115 #ifdef DEBUG
116 #define CCDB_FOLLOW	0x01
117 #define CCDB_INIT	0x02
118 #define CCDB_IO		0x04
119 #define CCDB_LABEL	0x08
120 #define CCDB_VNODE	0x10
121 static int ccddebug = CCDB_FOLLOW | CCDB_INIT | CCDB_IO | CCDB_LABEL |
122     CCDB_VNODE;
123 SYSCTL_INT(_debug, OID_AUTO, ccddebug, CTLFLAG_RW, &ccddebug, 0, "");
124 #endif
125 
126 #define	ccdunit(x)	dkunit(x)
127 #define ccdpart(x)	dkpart(x)
128 
129 /*
130    This is how mirroring works (only writes are special):
131 
132    When initiating a write, ccdbuffer() returns two "struct ccdbuf *"s
133    linked together by the cb_mirror field.  "cb_pflags &
134    CCDPF_MIRROR_DONE" is set to 0 on both of them.
135 
136    When a component returns to ccdiodone(), it checks if "cb_pflags &
137    CCDPF_MIRROR_DONE" is set or not.  If not, it sets the partner's
138    flag and returns.  If it is, it means its partner has already
139    returned, so it will go to the regular cleanup.
140 
141  */
142 
143 struct ccdbuf {
144 	struct bio	cb_buf;		/* new I/O buf */
145 	struct bio	*cb_obp;	/* ptr. to original I/O buf */
146 	struct ccdbuf	*cb_freenext;	/* free list link */
147 	int		cb_unit;	/* target unit */
148 	int		cb_comp;	/* target component */
149 	int		cb_pflags;	/* mirror/parity status flag */
150 	struct ccdbuf	*cb_mirror;	/* mirror counterpart */
151 };
152 
153 /* bits in cb_pflags */
154 #define CCDPF_MIRROR_DONE 1	/* if set, mirror counterpart is done */
155 
156 #define CCDLABELDEV(dev)	\
157 	(makedev(major((dev)), dkmakeminor(ccdunit((dev)), 0, RAW_PART)))
158 
159 /* convinient macros for often-used statements */
160 #define IS_ALLOCATED(unit)	(ccdfind(unit) != NULL)
161 #define IS_INITED(cs)		(((cs)->sc_flags & CCDF_INITED) != 0)
162 
163 static d_open_t ccdopen;
164 static d_close_t ccdclose;
165 static d_strategy_t ccdstrategy;
166 static d_ioctl_t ccdioctl;
167 static d_psize_t ccdsize;
168 
169 #define NCCDFREEHIWAT	16
170 
171 #define CDEV_MAJOR 74
172 
173 static struct cdevsw ccd_cdevsw = {
174 	/* open */	ccdopen,
175 	/* close */	ccdclose,
176 	/* read */	physread,
177 	/* write */	physwrite,
178 	/* ioctl */	ccdioctl,
179 	/* poll */	nopoll,
180 	/* mmap */	nommap,
181 	/* strategy */	ccdstrategy,
182 	/* name */	"ccd",
183 	/* maj */	CDEV_MAJOR,
184 	/* dump */	nodump,
185 	/* psize */	ccdsize,
186 	/* flags */	D_DISK,
187 };
188 static LIST_HEAD(, ccd_s) ccd_softc_list = LIST_HEAD_INITIALIZER(&ccd_softc_list);
189 
190 static struct ccd_s *ccdfind(int);
191 static struct ccd_s *ccdnew(int);
192 static int ccddestroy(struct ccd_s *, struct proc *);
193 
194 /* called during module initialization */
195 static void ccdattach(void);
196 static int ccd_modevent(module_t, int, void *);
197 
198 /* called by biodone() at interrupt time */
199 static void ccdiodone(struct bio *bp);
200 
201 static void ccdstart(struct ccd_s *, struct bio *);
202 static void ccdinterleave(struct ccd_s *, int);
203 static void ccdintr(struct ccd_s *, struct bio *);
204 static int ccdinit(struct ccd_s *, char **, struct thread *);
205 static int ccdlookup(char *, struct thread *p, struct vnode **);
206 static void ccdbuffer(struct ccdbuf **ret, struct ccd_s *,
207 		      struct bio *, daddr_t, caddr_t, long);
208 static void ccdgetdisklabel(dev_t);
209 static void ccdmakedisklabel(struct ccd_s *);
210 static int ccdlock(struct ccd_s *);
211 static void ccdunlock(struct ccd_s *);
212 
213 #ifdef DEBUG
214 static void printiinfo(struct ccdiinfo *);
215 #endif
216 
217 /* Non-private for the benefit of libkvm. */
218 struct ccdbuf *ccdfreebufs;
219 static int numccdfreebufs;
220 
221 /*
222  * getccdbuf() -	Allocate and zero a ccd buffer.
223  *
224  *	This routine is called at splbio().
225  */
226 
227 static __inline
228 struct ccdbuf *
229 getccdbuf(struct ccdbuf *cpy)
230 {
231 	struct ccdbuf *cbp;
232 
233 	/*
234 	 * Allocate from freelist or malloc as necessary
235 	 */
236 	if ((cbp = ccdfreebufs) != NULL) {
237 		ccdfreebufs = cbp->cb_freenext;
238 		--numccdfreebufs;
239 	} else {
240 		cbp = malloc(sizeof(struct ccdbuf), M_DEVBUF, M_WAITOK);
241 	}
242 
243 	/*
244 	 * Used by mirroring code
245 	 */
246 	if (cpy)
247 		bcopy(cpy, cbp, sizeof(struct ccdbuf));
248 	else
249 		bzero(cbp, sizeof(struct ccdbuf));
250 
251 	/*
252 	 * independant struct bio initialization
253 	 */
254 
255 	return(cbp);
256 }
257 
258 /*
259  * putccdbuf() -	Free a ccd buffer.
260  *
261  *	This routine is called at splbio().
262  */
263 
264 static __inline
265 void
266 putccdbuf(struct ccdbuf *cbp)
267 {
268 
269 	if (numccdfreebufs < NCCDFREEHIWAT) {
270 		cbp->cb_freenext = ccdfreebufs;
271 		ccdfreebufs = cbp;
272 		++numccdfreebufs;
273 	} else {
274 		free((caddr_t)cbp, M_DEVBUF);
275 	}
276 }
277 
278 
279 /*
280  * Number of blocks to untouched in front of a component partition.
281  * This is to avoid violating its disklabel area when it starts at the
282  * beginning of the slice.
283  */
284 #if !defined(CCD_OFFSET)
285 #define CCD_OFFSET 16
286 #endif
287 
288 static struct ccd_s *
289 ccdfind(int unit)
290 {
291 	struct ccd_s *sc = NULL;
292 
293 	/* XXX: LOCK(unique unit numbers) */
294 	LIST_FOREACH(sc, &ccd_softc_list, list) {
295 		if (sc->sc_unit == unit)
296 			break;
297 	}
298 	/* XXX: UNLOCK(unique unit numbers) */
299 	return ((sc == NULL) || (sc->sc_unit != unit) ? NULL : sc);
300 }
301 
302 static struct ccd_s *
303 ccdnew(int unit)
304 {
305 	struct ccd_s *sc;
306 
307 	/* XXX: LOCK(unique unit numbers) */
308 	if (IS_ALLOCATED(unit) || unit > DKMAXUNIT)
309 		return (NULL);
310 
311 	MALLOC(sc, struct ccd_s *, sizeof(*sc), M_CCD, M_WAITOK | M_ZERO);
312 	sc->sc_unit = unit;
313 	LIST_INSERT_HEAD(&ccd_softc_list, sc, list);
314 	/* XXX: UNLOCK(unique unit numbers) */
315 	return (sc);
316 }
317 
318 static int
319 ccddestroy(struct ccd_s *sc, struct proc *p)
320 {
321 
322 	/* XXX: LOCK(unique unit numbers) */
323 	LIST_REMOVE(sc, list);
324 	/* XXX: UNLOCK(unique unit numbers) */
325 	FREE(sc, M_CCD);
326 	return (0);
327 }
328 
329 static void
330 ccd_clone(void *arg, char *name, int namelen, dev_t *dev)
331 {
332 	int i, u;
333 	char *s;
334 
335 	if (*dev != NODEV)
336 		return;
337 	i = dev_stdclone(name, &s, "ccd", &u);
338 	if (i != 2)
339 		return;
340 	if (*s < 'a' || *s > 'h')
341 		return;
342 	if (s[1] != '\0')
343 		return;
344 	*dev = make_dev(&ccd_cdevsw, u * 8 + *s - 'a',
345 		UID_ROOT, GID_OPERATOR, 0640, name);
346 }
347 
348 /*
349  * Called by main() during pseudo-device attachment.  All we need
350  * to do is to add devsw entries.
351  */
352 static void
353 ccdattach()
354 {
355 
356 	EVENTHANDLER_REGISTER(dev_clone, ccd_clone, 0, 1000);
357 }
358 
359 static int
360 ccd_modevent(module_t mod, int type, void *data)
361 {
362 	int error = 0;
363 
364 	switch (type) {
365 	case MOD_LOAD:
366 		ccdattach();
367 		break;
368 
369 	case MOD_UNLOAD:
370 		printf("ccd0: Unload not supported!\n");
371 		error = EOPNOTSUPP;
372 		break;
373 
374 	case MOD_SHUTDOWN:
375 		break;
376 
377 	default:
378 		error = EOPNOTSUPP;
379 	}
380 	return (error);
381 }
382 
383 DEV_MODULE(ccd, ccd_modevent, NULL);
384 
385 static int
386 ccdinit(struct ccd_s *cs, char **cpaths, struct thread *td)
387 {
388 	struct ccdcinfo *ci = NULL;	/* XXX */
389 	size_t size;
390 	int ix;
391 	struct vnode *vp;
392 	size_t minsize;
393 	int maxsecsize;
394 	struct ccdgeom *ccg = &cs->sc_geom;
395 	char *tmppath = NULL;
396 	int error = 0;
397 	off_t mediasize;
398 	u_int sectorsize;
399 
400 #ifdef DEBUG
401 	if (ccddebug & (CCDB_FOLLOW|CCDB_INIT))
402 		printf("ccdinit: unit %d\n", cs->sc_unit);
403 #endif
404 
405 	cs->sc_size = 0;
406 
407 	/* Allocate space for the component info. */
408 	cs->sc_cinfo = malloc(cs->sc_nccdisks * sizeof(struct ccdcinfo),
409 	    M_DEVBUF, M_WAITOK);
410 
411 	/*
412 	 * Verify that each component piece exists and record
413 	 * relevant information about it.
414 	 */
415 	maxsecsize = 0;
416 	minsize = 0;
417 	tmppath = malloc(MAXPATHLEN, M_DEVBUF, M_WAITOK);
418 	for (ix = 0; ix < cs->sc_nccdisks; ix++) {
419 		vp = cs->sc_vpp[ix];
420 		ci = &cs->sc_cinfo[ix];
421 		ci->ci_vp = vp;
422 
423 		/*
424 		 * Copy in the pathname of the component.
425 		 */
426 		if ((error = copyinstr(cpaths[ix], tmppath,
427 		    MAXPATHLEN, &ci->ci_pathlen)) != 0) {
428 #ifdef DEBUG
429 			if (ccddebug & (CCDB_FOLLOW|CCDB_INIT))
430 				printf("ccd%d: can't copy path, error = %d\n",
431 				    cs->sc_unit, error);
432 #endif
433 			goto fail;
434 		}
435 		ci->ci_path = malloc(ci->ci_pathlen, M_DEVBUF, M_WAITOK);
436 		bcopy(tmppath, ci->ci_path, ci->ci_pathlen);
437 
438 		ci->ci_dev = vn_todev(vp);
439 
440 		/*
441 		 * Get partition information for the component.
442 		 */
443 		error = VOP_IOCTL(vp, DIOCGMEDIASIZE, (caddr_t)&mediasize,
444 		    FREAD, td->td_ucred, td);
445 		if (error != 0) {
446 #ifdef DEBUG
447 			if (ccddebug & (CCDB_FOLLOW|CCDB_INIT))
448 				 printf("ccd%d: %s: ioctl failed, error = %d\n",
449 				     cs->sc_unit, ci->ci_path, error);
450 #endif
451 			goto fail;
452 		}
453 		/*
454 		 * Get partition information for the component.
455 		 */
456 		error = VOP_IOCTL(vp, DIOCGSECTORSIZE, (caddr_t)&sectorsize,
457 		    FREAD, td->td_ucred, td);
458 		if (error != 0) {
459 #ifdef DEBUG
460 			if (ccddebug & (CCDB_FOLLOW|CCDB_INIT))
461 				 printf("ccd%d: %s: ioctl failed, error = %d\n",
462 				     cs->sc_unit, ci->ci_path, error);
463 #endif
464 			goto fail;
465 		}
466 		if (sectorsize > maxsecsize)
467 			maxsecsize = sectorsize;
468 		size = mediasize / DEV_BSIZE - CCD_OFFSET;
469 
470 		/*
471 		 * Calculate the size, truncating to an interleave
472 		 * boundary if necessary.
473 		 */
474 
475 		if (cs->sc_ileave > 1)
476 			size -= size % cs->sc_ileave;
477 
478 		if (size == 0) {
479 #ifdef DEBUG
480 			if (ccddebug & (CCDB_FOLLOW|CCDB_INIT))
481 				printf("ccd%d: %s: size == 0\n",
482 				    cs->sc_unit, ci->ci_path);
483 #endif
484 			error = ENODEV;
485 			goto fail;
486 		}
487 
488 		if (minsize == 0 || size < minsize)
489 			minsize = size;
490 		ci->ci_size = size;
491 		cs->sc_size += size;
492 	}
493 
494 	free(tmppath, M_DEVBUF);
495 	tmppath = NULL;
496 
497 	/*
498 	 * Don't allow the interleave to be smaller than
499 	 * the biggest component sector.
500 	 */
501 	if ((cs->sc_ileave > 0) &&
502 	    (cs->sc_ileave < (maxsecsize / DEV_BSIZE))) {
503 #ifdef DEBUG
504 		if (ccddebug & (CCDB_FOLLOW|CCDB_INIT))
505 			printf("ccd%d: interleave must be at least %d\n",
506 			    cs->sc_unit, (maxsecsize / DEV_BSIZE));
507 #endif
508 		error = EINVAL;
509 		goto fail;
510 	}
511 
512 	/*
513 	 * If uniform interleave is desired set all sizes to that of
514 	 * the smallest component.  This will guarentee that a single
515 	 * interleave table is generated.
516 	 *
517 	 * Lost space must be taken into account when calculating the
518 	 * overall size.  Half the space is lost when CCDF_MIRROR is
519 	 * specified.  One disk is lost when CCDF_PARITY is specified.
520 	 */
521 	if (cs->sc_flags & CCDF_UNIFORM) {
522 		for (ci = cs->sc_cinfo;
523 		     ci < &cs->sc_cinfo[cs->sc_nccdisks]; ci++) {
524 			ci->ci_size = minsize;
525 		}
526 		if (cs->sc_flags & CCDF_MIRROR) {
527 			/*
528 			 * Check to see if an even number of components
529 			 * have been specified.  The interleave must also
530 			 * be non-zero in order for us to be able to
531 			 * guarentee the topology.
532 			 */
533 			if (cs->sc_nccdisks % 2) {
534 				printf("ccd%d: mirroring requires an even number of disks\n", cs->sc_unit );
535 				error = EINVAL;
536 				goto fail;
537 			}
538 			if (cs->sc_ileave == 0) {
539 				printf("ccd%d: an interleave must be specified when mirroring\n", cs->sc_unit);
540 				error = EINVAL;
541 				goto fail;
542 			}
543 			cs->sc_size = (cs->sc_nccdisks/2) * minsize;
544 		} else if (cs->sc_flags & CCDF_PARITY) {
545 			cs->sc_size = (cs->sc_nccdisks-1) * minsize;
546 		} else {
547 			if (cs->sc_ileave == 0) {
548 				printf("ccd%d: an interleave must be specified when using parity\n", cs->sc_unit);
549 				error = EINVAL;
550 				goto fail;
551 			}
552 			cs->sc_size = cs->sc_nccdisks * minsize;
553 		}
554 	}
555 
556 	/*
557 	 * Construct the interleave table.
558 	 */
559 	ccdinterleave(cs, cs->sc_unit);
560 
561 	/*
562 	 * Create pseudo-geometry based on 1MB cylinders.  It's
563 	 * pretty close.
564 	 */
565 	ccg->ccg_secsize = maxsecsize;
566 	ccg->ccg_ntracks = 1;
567 	ccg->ccg_nsectors = 1024 * 1024 / ccg->ccg_secsize;
568 	ccg->ccg_ncylinders = cs->sc_size / ccg->ccg_nsectors;
569 
570 	/*
571 	 * Add an devstat entry for this device.
572 	 */
573 	devstat_add_entry(&cs->device_stats, "ccd", cs->sc_unit,
574 			  ccg->ccg_secsize, DEVSTAT_ALL_SUPPORTED,
575 			  DEVSTAT_TYPE_STORARRAY |DEVSTAT_TYPE_IF_OTHER,
576 			  DEVSTAT_PRIORITY_ARRAY);
577 
578 	cs->sc_flags |= CCDF_INITED;
579 	cs->sc_cflags = cs->sc_flags;	/* So we can find out later... */
580 	return (0);
581 fail:
582 	while (ci > cs->sc_cinfo) {
583 		ci--;
584 		free(ci->ci_path, M_DEVBUF);
585 	}
586 	if (tmppath != NULL)
587 		free(tmppath, M_DEVBUF);
588 	free(cs->sc_cinfo, M_DEVBUF);
589 	return (error);
590 }
591 
592 static void
593 ccdinterleave(struct ccd_s *cs, int unit)
594 {
595 	struct ccdcinfo *ci, *smallci;
596 	struct ccdiinfo *ii;
597 	daddr_t bn, lbn;
598 	int ix;
599 	u_long size;
600 
601 #ifdef DEBUG
602 	if (ccddebug & CCDB_INIT)
603 		printf("ccdinterleave(%p): ileave %d\n", cs, cs->sc_ileave);
604 #endif
605 
606 	/*
607 	 * Allocate an interleave table.  The worst case occurs when each
608 	 * of N disks is of a different size, resulting in N interleave
609 	 * tables.
610 	 *
611 	 * Chances are this is too big, but we don't care.
612 	 */
613 	size = (cs->sc_nccdisks + 1) * sizeof(struct ccdiinfo);
614 	cs->sc_itable = (struct ccdiinfo *)malloc(size, M_DEVBUF,
615 	    M_WAITOK | M_ZERO);
616 
617 	/*
618 	 * Trivial case: no interleave (actually interleave of disk size).
619 	 * Each table entry represents a single component in its entirety.
620 	 *
621 	 * An interleave of 0 may not be used with a mirror or parity setup.
622 	 */
623 	if (cs->sc_ileave == 0) {
624 		bn = 0;
625 		ii = cs->sc_itable;
626 
627 		for (ix = 0; ix < cs->sc_nccdisks; ix++) {
628 			/* Allocate space for ii_index. */
629 			ii->ii_index = malloc(sizeof(int), M_DEVBUF, M_WAITOK);
630 			ii->ii_ndisk = 1;
631 			ii->ii_startblk = bn;
632 			ii->ii_startoff = 0;
633 			ii->ii_index[0] = ix;
634 			bn += cs->sc_cinfo[ix].ci_size;
635 			ii++;
636 		}
637 		ii->ii_ndisk = 0;
638 #ifdef DEBUG
639 		if (ccddebug & CCDB_INIT)
640 			printiinfo(cs->sc_itable);
641 #endif
642 		return;
643 	}
644 
645 	/*
646 	 * The following isn't fast or pretty; it doesn't have to be.
647 	 */
648 	size = 0;
649 	bn = lbn = 0;
650 	for (ii = cs->sc_itable; ; ii++) {
651 		/*
652 		 * Allocate space for ii_index.  We might allocate more then
653 		 * we use.
654 		 */
655 		ii->ii_index = malloc((sizeof(int) * cs->sc_nccdisks),
656 		    M_DEVBUF, M_WAITOK);
657 
658 		/*
659 		 * Locate the smallest of the remaining components
660 		 */
661 		smallci = NULL;
662 		for (ci = cs->sc_cinfo; ci < &cs->sc_cinfo[cs->sc_nccdisks];
663 		    ci++) {
664 			if (ci->ci_size > size &&
665 			    (smallci == NULL ||
666 			     ci->ci_size < smallci->ci_size)) {
667 				smallci = ci;
668 			}
669 		}
670 
671 		/*
672 		 * Nobody left, all done
673 		 */
674 		if (smallci == NULL) {
675 			ii->ii_ndisk = 0;
676 			break;
677 		}
678 
679 		/*
680 		 * Record starting logical block using an sc_ileave blocksize.
681 		 */
682 		ii->ii_startblk = bn / cs->sc_ileave;
683 
684 		/*
685 		 * Record starting comopnent block using an sc_ileave
686 		 * blocksize.  This value is relative to the beginning of
687 		 * a component disk.
688 		 */
689 		ii->ii_startoff = lbn;
690 
691 		/*
692 		 * Determine how many disks take part in this interleave
693 		 * and record their indices.
694 		 */
695 		ix = 0;
696 		for (ci = cs->sc_cinfo;
697 		    ci < &cs->sc_cinfo[cs->sc_nccdisks]; ci++) {
698 			if (ci->ci_size >= smallci->ci_size) {
699 				ii->ii_index[ix++] = ci - cs->sc_cinfo;
700 			}
701 		}
702 		ii->ii_ndisk = ix;
703 		bn += ix * (smallci->ci_size - size);
704 		lbn = smallci->ci_size / cs->sc_ileave;
705 		size = smallci->ci_size;
706 	}
707 #ifdef DEBUG
708 	if (ccddebug & CCDB_INIT)
709 		printiinfo(cs->sc_itable);
710 #endif
711 }
712 
713 /* ARGSUSED */
714 static int
715 ccdopen(dev_t dev, int flags, int fmt, struct thread *td)
716 {
717 	int unit = ccdunit(dev);
718 	struct ccd_s *cs;
719 	struct disklabel *lp;
720 	int error = 0, part, pmask;
721 
722 #ifdef DEBUG
723 	if (ccddebug & CCDB_FOLLOW)
724 		printf("ccdopen(%p, %x)\n", dev, flags);
725 #endif
726 
727 	cs = IS_ALLOCATED(unit) ? ccdfind(unit) : ccdnew(unit);
728 
729 	if ((error = ccdlock(cs)) != 0)
730 		return (error);
731 
732 	lp = &cs->sc_label;
733 
734 	part = ccdpart(dev);
735 	pmask = (1 << part);
736 
737 	/*
738 	 * If we're initialized, check to see if there are any other
739 	 * open partitions.  If not, then it's safe to update
740 	 * the in-core disklabel.
741 	 */
742 	if (IS_INITED(cs) && (cs->sc_openmask == 0))
743 		ccdgetdisklabel(dev);
744 
745 	/* Check that the partition exists. */
746 	if (part != RAW_PART && ((part >= lp->d_npartitions) ||
747 	    (lp->d_partitions[part].p_fstype == FS_UNUSED))) {
748 		error = ENXIO;
749 		goto done;
750 	}
751 
752 	cs->sc_openmask |= pmask;
753  done:
754 	ccdunlock(cs);
755 	return (0);
756 }
757 
758 /* ARGSUSED */
759 static int
760 ccdclose(dev_t dev, int flags, int fmt, struct thread *td)
761 {
762 	int unit = ccdunit(dev);
763 	struct ccd_s *cs;
764 	int error = 0, part;
765 
766 #ifdef DEBUG
767 	if (ccddebug & CCDB_FOLLOW)
768 		printf("ccdclose(%p, %x)\n", dev, flags);
769 #endif
770 
771 	if (!IS_ALLOCATED(unit))
772 		return (ENXIO);
773 	cs = ccdfind(unit);
774 
775 	if ((error = ccdlock(cs)) != 0)
776 		return (error);
777 
778 	part = ccdpart(dev);
779 
780 	/* ...that much closer to allowing unconfiguration... */
781 	cs->sc_openmask &= ~(1 << part);
782 	/* collect "garbage" if possible */
783 	if (!IS_INITED(cs) && (cs->sc_flags & CCDF_WANTED) == 0)
784 		ccddestroy(cs, td->td_proc);
785 	else
786 		ccdunlock(cs);
787 	return (0);
788 }
789 
790 static void
791 ccdstrategy(struct bio *bp)
792 {
793 	int unit = ccdunit(bp->bio_dev);
794 	struct ccd_s *cs = ccdfind(unit);
795 	int s;
796 	int wlabel;
797 	struct disklabel *lp;
798 
799 #ifdef DEBUG
800 	if (ccddebug & CCDB_FOLLOW)
801 		printf("ccdstrategy(%p): unit %d\n", bp, unit);
802 #endif
803 	if (!IS_INITED(cs)) {
804 		biofinish(bp, NULL, ENXIO);
805 		return;
806 	}
807 
808 	/* If it's a nil transfer, wake up the top half now. */
809 	if (bp->bio_bcount == 0) {
810 		biodone(bp);
811 		return;
812 	}
813 
814 	lp = &cs->sc_label;
815 
816 	/*
817 	 * Do bounds checking and adjust transfer.  If there's an
818 	 * error, the bounds check will flag that for us.
819 	 */
820 	wlabel = cs->sc_flags & (CCDF_WLABEL|CCDF_LABELLING);
821 	if (ccdpart(bp->bio_dev) != RAW_PART) {
822 		if (bounds_check_with_label(bp, lp, wlabel) <= 0) {
823 			biodone(bp);
824 			return;
825 		}
826 	} else {
827 		int pbn;        /* in sc_secsize chunks */
828 		long sz;        /* in sc_secsize chunks */
829 
830 		pbn = bp->bio_blkno / (cs->sc_geom.ccg_secsize / DEV_BSIZE);
831 		sz = howmany(bp->bio_bcount, cs->sc_geom.ccg_secsize);
832 
833 		/*
834 		 * If out of bounds return an error. If at the EOF point,
835 		 * simply read or write less.
836 		 */
837 
838 		if (pbn < 0 || pbn >= cs->sc_size) {
839 			bp->bio_resid = bp->bio_bcount;
840 			if (pbn != cs->sc_size)
841 				biofinish(bp, NULL, EINVAL);
842 			else
843 				biodone(bp);
844 			return;
845 		}
846 
847 		/*
848 		 * If the request crosses EOF, truncate the request.
849 		 */
850 		if (pbn + sz > cs->sc_size) {
851 			bp->bio_bcount = (cs->sc_size - pbn) *
852 			    cs->sc_geom.ccg_secsize;
853 		}
854 	}
855 
856 	bp->bio_resid = bp->bio_bcount;
857 
858 	/*
859 	 * "Start" the unit.
860 	 */
861 	s = splbio();
862 	ccdstart(cs, bp);
863 	splx(s);
864 	return;
865 }
866 
867 static void
868 ccdstart(struct ccd_s *cs, struct bio *bp)
869 {
870 	long bcount, rcount;
871 	struct ccdbuf *cbp[4];
872 	/* XXX! : 2 reads and 2 writes for RAID 4/5 */
873 	caddr_t addr;
874 	daddr_t bn;
875 	struct partition *pp;
876 
877 #ifdef DEBUG
878 	if (ccddebug & CCDB_FOLLOW)
879 		printf("ccdstart(%p, %p)\n", cs, bp);
880 #endif
881 
882 	/* Record the transaction start  */
883 	devstat_start_transaction(&cs->device_stats);
884 
885 	/*
886 	 * Translate the partition-relative block number to an absolute.
887 	 */
888 	bn = bp->bio_blkno;
889 	if (ccdpart(bp->bio_dev) != RAW_PART) {
890 		pp = &cs->sc_label.d_partitions[ccdpart(bp->bio_dev)];
891 		bn += pp->p_offset;
892 	}
893 
894 	/*
895 	 * Allocate component buffers and fire off the requests
896 	 */
897 	addr = bp->bio_data;
898 	for (bcount = bp->bio_bcount; bcount > 0; bcount -= rcount) {
899 		ccdbuffer(cbp, cs, bp, bn, addr, bcount);
900 		rcount = cbp[0]->cb_buf.bio_bcount;
901 
902 		if (cs->sc_cflags & CCDF_MIRROR) {
903 			/*
904 			 * Mirroring.  Writes go to both disks, reads are
905 			 * taken from whichever disk seems most appropriate.
906 			 *
907 			 * We attempt to localize reads to the disk whos arm
908 			 * is nearest the read request.  We ignore seeks due
909 			 * to writes when making this determination and we
910 			 * also try to avoid hogging.
911 			 */
912 			if (cbp[0]->cb_buf.bio_cmd == BIO_WRITE) {
913 				BIO_STRATEGY(&cbp[0]->cb_buf, 0);
914 				BIO_STRATEGY(&cbp[1]->cb_buf, 0);
915 			} else {
916 				int pick = cs->sc_pick;
917 				daddr_t range = cs->sc_size / 16;
918 
919 				if (bn < cs->sc_blk[pick] - range ||
920 				    bn > cs->sc_blk[pick] + range
921 				) {
922 					cs->sc_pick = pick = 1 - pick;
923 				}
924 				cs->sc_blk[pick] = bn + btodb(rcount);
925 				BIO_STRATEGY(&cbp[pick]->cb_buf, 0);
926 			}
927 		} else {
928 			/*
929 			 * Not mirroring
930 			 */
931 			BIO_STRATEGY(&cbp[0]->cb_buf, 0);
932 		}
933 		bn += btodb(rcount);
934 		addr += rcount;
935 	}
936 }
937 
938 /*
939  * Build a component buffer header.
940  */
941 static void
942 ccdbuffer(struct ccdbuf **cb, struct ccd_s *cs, struct bio *bp, daddr_t bn, caddr_t addr, long bcount)
943 {
944 	struct ccdcinfo *ci, *ci2 = NULL;	/* XXX */
945 	struct ccdbuf *cbp;
946 	daddr_t cbn, cboff;
947 	off_t cbc;
948 
949 #ifdef DEBUG
950 	if (ccddebug & CCDB_IO)
951 		printf("ccdbuffer(%p, %p, %d, %p, %ld)\n",
952 		       cs, bp, bn, addr, bcount);
953 #endif
954 	/*
955 	 * Determine which component bn falls in.
956 	 */
957 	cbn = bn;
958 	cboff = 0;
959 
960 	if (cs->sc_ileave == 0) {
961 		/*
962 		 * Serially concatenated and neither a mirror nor a parity
963 		 * config.  This is a special case.
964 		 */
965 		daddr_t sblk;
966 
967 		sblk = 0;
968 		for (ci = cs->sc_cinfo; cbn >= sblk + ci->ci_size; ci++)
969 			sblk += ci->ci_size;
970 		cbn -= sblk;
971 	} else {
972 		struct ccdiinfo *ii;
973 		int ccdisk, off;
974 
975 		/*
976 		 * Calculate cbn, the logical superblock (sc_ileave chunks),
977 		 * and cboff, a normal block offset (DEV_BSIZE chunks) relative
978 		 * to cbn.
979 		 */
980 		cboff = cbn % cs->sc_ileave;	/* DEV_BSIZE gran */
981 		cbn = cbn / cs->sc_ileave;	/* DEV_BSIZE * ileave gran */
982 
983 		/*
984 		 * Figure out which interleave table to use.
985 		 */
986 		for (ii = cs->sc_itable; ii->ii_ndisk; ii++) {
987 			if (ii->ii_startblk > cbn)
988 				break;
989 		}
990 		ii--;
991 
992 		/*
993 		 * off is the logical superblock relative to the beginning
994 		 * of this interleave block.
995 		 */
996 		off = cbn - ii->ii_startblk;
997 
998 		/*
999 		 * We must calculate which disk component to use (ccdisk),
1000 		 * and recalculate cbn to be the superblock relative to
1001 		 * the beginning of the component.  This is typically done by
1002 		 * adding 'off' and ii->ii_startoff together.  However, 'off'
1003 		 * must typically be divided by the number of components in
1004 		 * this interleave array to be properly convert it from a
1005 		 * CCD-relative logical superblock number to a
1006 		 * component-relative superblock number.
1007 		 */
1008 		if (ii->ii_ndisk == 1) {
1009 			/*
1010 			 * When we have just one disk, it can't be a mirror
1011 			 * or a parity config.
1012 			 */
1013 			ccdisk = ii->ii_index[0];
1014 			cbn = ii->ii_startoff + off;
1015 		} else {
1016 			if (cs->sc_cflags & CCDF_MIRROR) {
1017 				/*
1018 				 * We have forced a uniform mapping, resulting
1019 				 * in a single interleave array.  We double
1020 				 * up on the first half of the available
1021 				 * components and our mirror is in the second
1022 				 * half.  This only works with a single
1023 				 * interleave array because doubling up
1024 				 * doubles the number of sectors, so there
1025 				 * cannot be another interleave array because
1026 				 * the next interleave array's calculations
1027 				 * would be off.
1028 				 */
1029 				int ndisk2 = ii->ii_ndisk / 2;
1030 				ccdisk = ii->ii_index[off % ndisk2];
1031 				cbn = ii->ii_startoff + off / ndisk2;
1032 				ci2 = &cs->sc_cinfo[ccdisk + ndisk2];
1033 			} else if (cs->sc_cflags & CCDF_PARITY) {
1034 				/*
1035 				 * XXX not implemented yet
1036 				 */
1037 				int ndisk2 = ii->ii_ndisk - 1;
1038 				ccdisk = ii->ii_index[off % ndisk2];
1039 				cbn = ii->ii_startoff + off / ndisk2;
1040 				if (cbn % ii->ii_ndisk <= ccdisk)
1041 					ccdisk++;
1042 			} else {
1043 				ccdisk = ii->ii_index[off % ii->ii_ndisk];
1044 				cbn = ii->ii_startoff + off / ii->ii_ndisk;
1045 			}
1046 		}
1047 
1048 		ci = &cs->sc_cinfo[ccdisk];
1049 
1050 		/*
1051 		 * Convert cbn from a superblock to a normal block so it
1052 		 * can be used to calculate (along with cboff) the normal
1053 		 * block index into this particular disk.
1054 		 */
1055 		cbn *= cs->sc_ileave;
1056 	}
1057 
1058 	/*
1059 	 * Fill in the component buf structure.
1060 	 */
1061 	cbp = getccdbuf(NULL);
1062 	cbp->cb_buf.bio_cmd = bp->bio_cmd;
1063 	cbp->cb_buf.bio_done = ccdiodone;
1064 	cbp->cb_buf.bio_dev = ci->ci_dev;		/* XXX */
1065 	cbp->cb_buf.bio_blkno = cbn + cboff + CCD_OFFSET;
1066 	cbp->cb_buf.bio_offset = dbtob(cbn + cboff + CCD_OFFSET);
1067 	cbp->cb_buf.bio_data = addr;
1068 	if (cs->sc_ileave == 0)
1069               cbc = dbtob((off_t)(ci->ci_size - cbn));
1070 	else
1071               cbc = dbtob((off_t)(cs->sc_ileave - cboff));
1072 	cbp->cb_buf.bio_bcount = (cbc < bcount) ? cbc : bcount;
1073  	cbp->cb_buf.bio_caller1 = (void*)cbp->cb_buf.bio_bcount;
1074 
1075 	/*
1076 	 * context for ccdiodone
1077 	 */
1078 	cbp->cb_obp = bp;
1079 	cbp->cb_unit = cs->sc_unit;
1080 	cbp->cb_comp = ci - cs->sc_cinfo;
1081 
1082 #ifdef DEBUG
1083 	if (ccddebug & CCDB_IO)
1084 		printf(" dev %p(u%ld): cbp %p bn %lld addr %p bcnt %ld\n",
1085 		       ci->ci_dev, (unsigned long)(ci-cs->sc_cinfo), cbp,
1086 		       (long long)cbp->cb_buf.bio_blkno, cbp->cb_buf.bio_data,
1087 		       cbp->cb_buf.bio_bcount);
1088 #endif
1089 	cb[0] = cbp;
1090 
1091 	/*
1092 	 * Note: both I/O's setup when reading from mirror, but only one
1093 	 * will be executed.
1094 	 */
1095 	if (cs->sc_cflags & CCDF_MIRROR) {
1096 		/* mirror, setup second I/O */
1097 		cbp = getccdbuf(cb[0]);
1098 		cbp->cb_buf.bio_dev = ci2->ci_dev;
1099 		cbp->cb_comp = ci2 - cs->sc_cinfo;
1100 		cb[1] = cbp;
1101 		/* link together the ccdbuf's and clear "mirror done" flag */
1102 		cb[0]->cb_mirror = cb[1];
1103 		cb[1]->cb_mirror = cb[0];
1104 		cb[0]->cb_pflags &= ~CCDPF_MIRROR_DONE;
1105 		cb[1]->cb_pflags &= ~CCDPF_MIRROR_DONE;
1106 	}
1107 }
1108 
1109 static void
1110 ccdintr(struct ccd_s *cs, struct bio *bp)
1111 {
1112 #ifdef DEBUG
1113 	if (ccddebug & CCDB_FOLLOW)
1114 		printf("ccdintr(%p, %p)\n", cs, bp);
1115 #endif
1116 	/*
1117 	 * Request is done for better or worse, wakeup the top half.
1118 	 */
1119 	if (bp->bio_flags & BIO_ERROR)
1120 		bp->bio_resid = bp->bio_bcount;
1121 	biofinish(bp, &cs->device_stats, 0);
1122 }
1123 
1124 /*
1125  * Called at interrupt time.
1126  * Mark the component as done and if all components are done,
1127  * take a ccd interrupt.
1128  */
1129 static void
1130 ccdiodone(struct bio *ibp)
1131 {
1132 	struct ccdbuf *cbp = (struct ccdbuf *)ibp;
1133 	struct bio *bp = cbp->cb_obp;
1134 	int unit = cbp->cb_unit;
1135 	int count, s;
1136 
1137 	s = splbio();
1138 #ifdef DEBUG
1139 	if (ccddebug & CCDB_FOLLOW)
1140 		printf("ccdiodone(%p)\n", cbp);
1141 	if (ccddebug & CCDB_IO) {
1142 		printf("ccdiodone: bp %p bcount %ld resid %ld\n",
1143 		       bp, bp->bio_bcount, bp->bio_resid);
1144 		printf(" dev %p(u%d), cbp %p bn %lld addr %p bcnt %ld\n",
1145 		       cbp->cb_buf.bio_dev, cbp->cb_comp, cbp,
1146 		       (long long)cbp->cb_buf.bio_blkno, cbp->cb_buf.bio_data,
1147 		       cbp->cb_buf.bio_bcount);
1148 	}
1149 #endif
1150 	/*
1151 	 * If an error occured, report it.  If this is a mirrored
1152 	 * configuration and the first of two possible reads, do not
1153 	 * set the error in the bp yet because the second read may
1154 	 * succeed.
1155 	 */
1156 
1157 	if (cbp->cb_buf.bio_flags & BIO_ERROR) {
1158 		const char *msg = "";
1159 
1160 		if ((ccdfind(unit)->sc_cflags & CCDF_MIRROR) &&
1161 		    (cbp->cb_buf.bio_cmd == BIO_READ) &&
1162 		    (cbp->cb_pflags & CCDPF_MIRROR_DONE) == 0) {
1163 			/*
1164 			 * We will try our read on the other disk down
1165 			 * below, also reverse the default pick so if we
1166 			 * are doing a scan we do not keep hitting the
1167 			 * bad disk first.
1168 			 */
1169 			struct ccd_s *cs = ccdfind(unit);
1170 
1171 			msg = ", trying other disk";
1172 			cs->sc_pick = 1 - cs->sc_pick;
1173 			cs->sc_blk[cs->sc_pick] = bp->bio_blkno;
1174 		} else {
1175 			bp->bio_flags |= BIO_ERROR;
1176 			bp->bio_error = cbp->cb_buf.bio_error ?
1177 			    cbp->cb_buf.bio_error : EIO;
1178 		}
1179 		printf("ccd%d: error %d on component %d block %d (ccd block %lld)%s\n",
1180 		       unit, bp->bio_error, cbp->cb_comp,
1181 		       (int)cbp->cb_buf.bio_blkno, bp->bio_blkno, msg);
1182 	}
1183 
1184 	/*
1185 	 * Process mirror.  If we are writing, I/O has been initiated on both
1186 	 * buffers and we fall through only after both are finished.
1187 	 *
1188 	 * If we are reading only one I/O is initiated at a time.  If an
1189 	 * error occurs we initiate the second I/O and return, otherwise
1190 	 * we free the second I/O without initiating it.
1191 	 */
1192 
1193 	if (ccdfind(unit)->sc_cflags & CCDF_MIRROR) {
1194 		if (cbp->cb_buf.bio_cmd == BIO_WRITE) {
1195 			/*
1196 			 * When writing, handshake with the second buffer
1197 			 * to determine when both are done.  If both are not
1198 			 * done, return here.
1199 			 */
1200 			if ((cbp->cb_pflags & CCDPF_MIRROR_DONE) == 0) {
1201 				cbp->cb_mirror->cb_pflags |= CCDPF_MIRROR_DONE;
1202 				putccdbuf(cbp);
1203 				splx(s);
1204 				return;
1205 			}
1206 		} else {
1207 			/*
1208 			 * When reading, either dispose of the second buffer
1209 			 * or initiate I/O on the second buffer if an error
1210 			 * occured with this one.
1211 			 */
1212 			if ((cbp->cb_pflags & CCDPF_MIRROR_DONE) == 0) {
1213 				if (cbp->cb_buf.bio_flags & BIO_ERROR) {
1214 					cbp->cb_mirror->cb_pflags |=
1215 					    CCDPF_MIRROR_DONE;
1216 					BIO_STRATEGY(&cbp->cb_mirror->cb_buf, 0);
1217 					putccdbuf(cbp);
1218 					splx(s);
1219 					return;
1220 				} else {
1221 					putccdbuf(cbp->cb_mirror);
1222 					/* fall through */
1223 				}
1224 			}
1225 		}
1226 	}
1227 
1228 	/*
1229 	 * use bio_caller1 to determine how big the original request was rather
1230 	 * then bio_bcount, because bio_bcount may have been truncated for EOF.
1231 	 *
1232 	 * XXX We check for an error, but we do not test the resid for an
1233 	 * aligned EOF condition.  This may result in character & block
1234 	 * device access not recognizing EOF properly when read or written
1235 	 * sequentially, but will not effect filesystems.
1236 	 */
1237 	count = (long)cbp->cb_buf.bio_caller1;
1238 	putccdbuf(cbp);
1239 
1240 	/*
1241 	 * If all done, "interrupt".
1242 	 */
1243 	bp->bio_resid -= count;
1244 	if (bp->bio_resid < 0)
1245 		panic("ccdiodone: count");
1246 	if (bp->bio_resid == 0)
1247 		ccdintr(ccdfind(unit), bp);
1248 	splx(s);
1249 }
1250 
1251 static int
1252 ccdioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct thread *td)
1253 {
1254 	int unit = ccdunit(dev);
1255 	int i, j, lookedup = 0, error = 0;
1256 	int part, pmask, s;
1257 	struct ccd_s *cs;
1258 	struct ccd_ioctl *ccio = (struct ccd_ioctl *)data;
1259 	char **cpp;
1260 	struct vnode **vpp;
1261 
1262 	if (!IS_ALLOCATED(unit))
1263 		return (ENXIO);
1264 	cs = ccdfind(unit);
1265 
1266 	switch (cmd) {
1267 	case CCDIOCSET:
1268 		if (IS_INITED(cs))
1269 			return (EBUSY);
1270 
1271 		if ((flag & FWRITE) == 0)
1272 			return (EBADF);
1273 
1274 		if ((error = ccdlock(cs)) != 0)
1275 			return (error);
1276 
1277 		if (ccio->ccio_ndisks > CCD_MAXNDISKS)
1278 			return (EINVAL);
1279 
1280 		/* Fill in some important bits. */
1281 		cs->sc_ileave = ccio->ccio_ileave;
1282 		if (cs->sc_ileave == 0 &&
1283 		    ((ccio->ccio_flags & CCDF_MIRROR) ||
1284 		     (ccio->ccio_flags & CCDF_PARITY))) {
1285 			printf("ccd%d: disabling mirror/parity, interleave is 0\n", unit);
1286 			ccio->ccio_flags &= ~(CCDF_MIRROR | CCDF_PARITY);
1287 		}
1288 		if ((ccio->ccio_flags & CCDF_MIRROR) &&
1289 		    (ccio->ccio_flags & CCDF_PARITY)) {
1290 			printf("ccd%d: can't specify both mirror and parity, using mirror\n", unit);
1291 			ccio->ccio_flags &= ~CCDF_PARITY;
1292 		}
1293 		if ((ccio->ccio_flags & (CCDF_MIRROR | CCDF_PARITY)) &&
1294 		    !(ccio->ccio_flags & CCDF_UNIFORM)) {
1295 			printf("ccd%d: mirror/parity forces uniform flag\n",
1296 			       unit);
1297 			ccio->ccio_flags |= CCDF_UNIFORM;
1298 		}
1299 		cs->sc_flags = ccio->ccio_flags & CCDF_USERMASK;
1300 
1301 		/*
1302 		 * Allocate space for and copy in the array of
1303 		 * componet pathnames and device numbers.
1304 		 */
1305 		cpp = malloc(ccio->ccio_ndisks * sizeof(char *),
1306 		    M_DEVBUF, M_WAITOK);
1307 		vpp = malloc(ccio->ccio_ndisks * sizeof(struct vnode *),
1308 		    M_DEVBUF, M_WAITOK);
1309 
1310 		error = copyin((caddr_t)ccio->ccio_disks, (caddr_t)cpp,
1311 		    ccio->ccio_ndisks * sizeof(char **));
1312 		if (error) {
1313 			free(vpp, M_DEVBUF);
1314 			free(cpp, M_DEVBUF);
1315 			ccdunlock(cs);
1316 			return (error);
1317 		}
1318 
1319 #ifdef DEBUG
1320 		if (ccddebug & CCDB_INIT)
1321 			for (i = 0; i < ccio->ccio_ndisks; ++i)
1322 				printf("ccdioctl: component %d: %p\n",
1323 				    i, cpp[i]);
1324 #endif
1325 
1326 		for (i = 0; i < ccio->ccio_ndisks; ++i) {
1327 #ifdef DEBUG
1328 			if (ccddebug & CCDB_INIT)
1329 				printf("ccdioctl: lookedup = %d\n", lookedup);
1330 #endif
1331 			if ((error = ccdlookup(cpp[i], td, &vpp[i])) != 0) {
1332 				for (j = 0; j < lookedup; ++j)
1333 					(void)vn_close(vpp[j], FREAD|FWRITE,
1334 					    td->td_ucred, td);
1335 				free(vpp, M_DEVBUF);
1336 				free(cpp, M_DEVBUF);
1337 				ccdunlock(cs);
1338 				return (error);
1339 			}
1340 			++lookedup;
1341 		}
1342 		cs->sc_vpp = vpp;
1343 		cs->sc_nccdisks = ccio->ccio_ndisks;
1344 
1345 		/*
1346 		 * Initialize the ccd.  Fills in the softc for us.
1347 		 */
1348 		if ((error = ccdinit(cs, cpp, td)) != 0) {
1349 			for (j = 0; j < lookedup; ++j)
1350 				(void)vn_close(vpp[j], FREAD|FWRITE,
1351 				    td->td_ucred, td);
1352 			/*
1353 			 * We can't ccddestroy() cs just yet, because nothing
1354 			 * prevents user-level app to do another ioctl()
1355 			 * without closing the device first, therefore
1356 			 * declare unit null and void and let ccdclose()
1357 			 * destroy it when it is safe to do so.
1358 			 */
1359 			cs->sc_flags &= (CCDF_WANTED | CCDF_LOCKED);
1360 			free(vpp, M_DEVBUF);
1361 			free(cpp, M_DEVBUF);
1362 			ccdunlock(cs);
1363 			return (error);
1364 		}
1365 
1366 		/*
1367 		 * The ccd has been successfully initialized, so
1368 		 * we can place it into the array and read the disklabel.
1369 		 */
1370 		ccio->ccio_unit = unit;
1371 		ccio->ccio_size = cs->sc_size;
1372 		ccdgetdisklabel(dev);
1373 
1374 		ccdunlock(cs);
1375 
1376 		break;
1377 
1378 	case CCDIOCCLR:
1379 		if (!IS_INITED(cs))
1380 			return (ENXIO);
1381 
1382 		if ((flag & FWRITE) == 0)
1383 			return (EBADF);
1384 
1385 		if ((error = ccdlock(cs)) != 0)
1386 			return (error);
1387 
1388 		/* Don't unconfigure if any other partitions are open */
1389 		part = ccdpart(dev);
1390 		pmask = (1 << part);
1391 		if ((cs->sc_openmask & ~pmask)) {
1392 			ccdunlock(cs);
1393 			return (EBUSY);
1394 		}
1395 
1396 		/* Declare unit null and void (reset all flags) */
1397 		cs->sc_flags &= (CCDF_WANTED | CCDF_LOCKED);
1398 
1399 		/* Close the components and free their pathnames. */
1400 		for (i = 0; i < cs->sc_nccdisks; ++i) {
1401 			/*
1402 			 * XXX: this close could potentially fail and
1403 			 * cause Bad Things.  Maybe we need to force
1404 			 * the close to happen?
1405 			 */
1406 #ifdef DEBUG
1407 			if (ccddebug & CCDB_VNODE)
1408 				vprint("CCDIOCCLR: vnode info",
1409 				    cs->sc_cinfo[i].ci_vp);
1410 #endif
1411 			(void)vn_close(cs->sc_cinfo[i].ci_vp, FREAD|FWRITE,
1412 			    td->td_ucred, td);
1413 			free(cs->sc_cinfo[i].ci_path, M_DEVBUF);
1414 		}
1415 
1416 		/* Free interleave index. */
1417 		for (i = 0; cs->sc_itable[i].ii_ndisk; ++i)
1418 			free(cs->sc_itable[i].ii_index, M_DEVBUF);
1419 
1420 		/* Free component info and interleave table. */
1421 		free(cs->sc_cinfo, M_DEVBUF);
1422 		free(cs->sc_itable, M_DEVBUF);
1423 		free(cs->sc_vpp, M_DEVBUF);
1424 
1425 		/* And remove the devstat entry. */
1426 		devstat_remove_entry(&cs->device_stats);
1427 
1428 		/* This must be atomic. */
1429 		s = splhigh();
1430 		ccdunlock(cs);
1431 		splx(s);
1432 
1433 		break;
1434 
1435 	case CCDCONFINFO:
1436 		{
1437 			int ninit = 0;
1438 			struct ccdconf *conf = (struct ccdconf *)data;
1439 			struct ccd_s *tmpcs;
1440 			struct ccd_s *ubuf = conf->buffer;
1441 
1442 			/* XXX: LOCK(unique unit numbers) */
1443 			LIST_FOREACH(tmpcs, &ccd_softc_list, list)
1444 				if (IS_INITED(tmpcs))
1445 					ninit++;
1446 
1447 			if (conf->size == 0) {
1448 				conf->size = sizeof(struct ccd_s) * ninit;
1449 				break;
1450 			} else if ((conf->size / sizeof(struct ccd_s) != ninit) ||
1451 			    (conf->size % sizeof(struct ccd_s) != 0)) {
1452 				/* XXX: UNLOCK(unique unit numbers) */
1453 				return (EINVAL);
1454 			}
1455 
1456 			ubuf += ninit;
1457 			LIST_FOREACH(tmpcs, &ccd_softc_list, list) {
1458 				if (!IS_INITED(tmpcs))
1459 					continue;
1460 				error = copyout(tmpcs, --ubuf,
1461 				    sizeof(struct ccd_s));
1462 				if (error != 0)
1463 					/* XXX: UNLOCK(unique unit numbers) */
1464 					return (error);
1465 			}
1466 			/* XXX: UNLOCK(unique unit numbers) */
1467 		}
1468 		break;
1469 
1470 	case CCDCPPINFO:
1471 		if (!IS_INITED(cs))
1472 			return (ENXIO);
1473 
1474 		{
1475 			int len = 0;
1476 			struct ccdcpps *cpps = (struct ccdcpps *)data;
1477 			char *ubuf = cpps->buffer;
1478 
1479 
1480 			for (i = 0; i < cs->sc_nccdisks; ++i)
1481 				len += cs->sc_cinfo[i].ci_pathlen;
1482 
1483 			if (cpps->size == 0) {
1484 				cpps->size = len;
1485 				break;
1486 			} else if (cpps->size != len) {
1487 				return (EINVAL);
1488 			}
1489 
1490 			for (i = 0; i < cs->sc_nccdisks; ++i) {
1491 				len = cs->sc_cinfo[i].ci_pathlen;
1492 				error = copyout(cs->sc_cinfo[i].ci_path, ubuf,
1493 				    len);
1494 				if (error != 0)
1495 					return (error);
1496 				ubuf += len;
1497 			}
1498 		}
1499 		break;
1500 
1501 	case DIOCGDINFO:
1502 		if (!IS_INITED(cs))
1503 			return (ENXIO);
1504 
1505 		*(struct disklabel *)data = cs->sc_label;
1506 		break;
1507 
1508 	case DIOCWDINFO:
1509 	case DIOCSDINFO:
1510 		if (!IS_INITED(cs))
1511 			return (ENXIO);
1512 
1513 		if ((flag & FWRITE) == 0)
1514 			return (EBADF);
1515 
1516 		if ((error = ccdlock(cs)) != 0)
1517 			return (error);
1518 
1519 		cs->sc_flags |= CCDF_LABELLING;
1520 
1521 		error = setdisklabel(&cs->sc_label,
1522 		    (struct disklabel *)data, 0);
1523 		if (error == 0) {
1524 			if (cmd == DIOCWDINFO)
1525 				error = writedisklabel(CCDLABELDEV(dev),
1526 				    &cs->sc_label);
1527 		}
1528 
1529 		cs->sc_flags &= ~CCDF_LABELLING;
1530 
1531 		ccdunlock(cs);
1532 
1533 		if (error)
1534 			return (error);
1535 		break;
1536 
1537 	case DIOCWLABEL:
1538 		if (!IS_INITED(cs))
1539 			return (ENXIO);
1540 
1541 		if ((flag & FWRITE) == 0)
1542 			return (EBADF);
1543 		if (*(int *)data != 0)
1544 			cs->sc_flags |= CCDF_WLABEL;
1545 		else
1546 			cs->sc_flags &= ~CCDF_WLABEL;
1547 		break;
1548 
1549 	default:
1550 		return (ENOTTY);
1551 	}
1552 
1553 	return (0);
1554 }
1555 
1556 static int
1557 ccdsize(dev_t dev)
1558 {
1559 	struct ccd_s *cs;
1560 	int part, size;
1561 
1562 	if (ccdopen(dev, 0, S_IFCHR, curthread))
1563 		return (-1);
1564 
1565 	cs = ccdfind(ccdunit(dev));
1566 	part = ccdpart(dev);
1567 
1568 	if (!IS_INITED(cs))
1569 		return (-1);
1570 
1571 	if (cs->sc_label.d_partitions[part].p_fstype != FS_SWAP)
1572 		size = -1;
1573 	else
1574 		size = cs->sc_label.d_partitions[part].p_size;
1575 
1576 	if (ccdclose(dev, 0, S_IFCHR, curthread))
1577 		return (-1);
1578 
1579 	return (size);
1580 }
1581 
1582 /*
1583  * Lookup the provided name in the filesystem.  If the file exists,
1584  * is a valid block device, and isn't being used by anyone else,
1585  * set *vpp to the file's vnode.
1586  */
1587 static int
1588 ccdlookup(char *path, struct thread *td, struct vnode **vpp)
1589 {
1590 	struct nameidata nd;
1591 	struct vnode *vp;
1592 	int error, flags;
1593 
1594 	NDINIT(&nd, LOOKUP, FOLLOW, UIO_USERSPACE, path, td);
1595 	flags = FREAD | FWRITE;
1596 	if ((error = vn_open(&nd, &flags, 0)) != 0) {
1597 #ifdef DEBUG
1598 		if (ccddebug & (CCDB_FOLLOW|CCDB_INIT))
1599 			printf("ccdlookup: vn_open error = %d\n", error);
1600 #endif
1601 		return (error);
1602 	}
1603 	vp = nd.ni_vp;
1604 
1605 	if (vp->v_usecount > 1) {
1606 		error = EBUSY;
1607 		goto bad;
1608 	}
1609 
1610 	if (!vn_isdisk(vp, &error))
1611 		goto bad;
1612 
1613 #ifdef DEBUG
1614 	if (ccddebug & CCDB_VNODE)
1615 		vprint("ccdlookup: vnode info", vp);
1616 #endif
1617 
1618 	VOP_UNLOCK(vp, 0, td);
1619 	NDFREE(&nd, NDF_ONLY_PNBUF);
1620 	*vpp = vp;
1621 	return (0);
1622 bad:
1623 	VOP_UNLOCK(vp, 0, td);
1624 	NDFREE(&nd, NDF_ONLY_PNBUF);
1625 	/* vn_close does vrele() for vp */
1626 	(void)vn_close(vp, FREAD|FWRITE, td->td_ucred, td);
1627 	return (error);
1628 }
1629 
1630 /*
1631  * Read the disklabel from the ccd.  If one is not present, fake one
1632  * up.
1633  */
1634 static void
1635 ccdgetdisklabel(dev_t dev)
1636 {
1637 	int unit = ccdunit(dev);
1638 	struct ccd_s *cs = ccdfind(unit);
1639 	char *errstring;
1640 	struct disklabel *lp = &cs->sc_label;
1641 	struct ccdgeom *ccg = &cs->sc_geom;
1642 
1643 	bzero(lp, sizeof(*lp));
1644 
1645 	lp->d_secperunit = cs->sc_size;
1646 	lp->d_secsize = ccg->ccg_secsize;
1647 	lp->d_nsectors = ccg->ccg_nsectors;
1648 	lp->d_ntracks = ccg->ccg_ntracks;
1649 	lp->d_ncylinders = ccg->ccg_ncylinders;
1650 	lp->d_secpercyl = lp->d_ntracks * lp->d_nsectors;
1651 
1652 	strncpy(lp->d_typename, "ccd", sizeof(lp->d_typename));
1653 	lp->d_type = DTYPE_CCD;
1654 	strncpy(lp->d_packname, "fictitious", sizeof(lp->d_packname));
1655 	lp->d_rpm = 3600;
1656 	lp->d_interleave = 1;
1657 	lp->d_flags = 0;
1658 
1659 	lp->d_partitions[RAW_PART].p_offset = 0;
1660 	lp->d_partitions[RAW_PART].p_size = cs->sc_size;
1661 	lp->d_partitions[RAW_PART].p_fstype = FS_UNUSED;
1662 	lp->d_npartitions = RAW_PART + 1;
1663 
1664 	lp->d_bbsize = BBSIZE;				/* XXX */
1665 	lp->d_sbsize = SBSIZE;				/* XXX */
1666 
1667 	lp->d_magic = DISKMAGIC;
1668 	lp->d_magic2 = DISKMAGIC;
1669 	lp->d_checksum = dkcksum(&cs->sc_label);
1670 
1671 	/*
1672 	 * Call the generic disklabel extraction routine.
1673 	 */
1674 	errstring = readdisklabel(CCDLABELDEV(dev), &cs->sc_label);
1675 	if (errstring != NULL)
1676 		ccdmakedisklabel(cs);
1677 
1678 #ifdef DEBUG
1679 	/* It's actually extremely common to have unlabeled ccds. */
1680 	if (ccddebug & CCDB_LABEL)
1681 		if (errstring != NULL)
1682 			printf("ccd%d: %s\n", unit, errstring);
1683 #endif
1684 }
1685 
1686 /*
1687  * Take care of things one might want to take care of in the event
1688  * that a disklabel isn't present.
1689  */
1690 static void
1691 ccdmakedisklabel(struct ccd_s *cs)
1692 {
1693 	struct disklabel *lp = &cs->sc_label;
1694 
1695 	/*
1696 	 * For historical reasons, if there's no disklabel present
1697 	 * the raw partition must be marked FS_BSDFFS.
1698 	 */
1699 	lp->d_partitions[RAW_PART].p_fstype = FS_BSDFFS;
1700 
1701 	strncpy(lp->d_packname, "default label", sizeof(lp->d_packname));
1702 }
1703 
1704 /*
1705  * Wait interruptibly for an exclusive lock.
1706  *
1707  * XXX
1708  * Several drivers do this; it should be abstracted and made MP-safe.
1709  */
1710 static int
1711 ccdlock(struct ccd_s *cs)
1712 {
1713 	int error;
1714 
1715 	while ((cs->sc_flags & CCDF_LOCKED) != 0) {
1716 		cs->sc_flags |= CCDF_WANTED;
1717 		if ((error = tsleep(cs, PRIBIO | PCATCH, "ccdlck", 0)) != 0)
1718 			return (error);
1719 	}
1720 	cs->sc_flags |= CCDF_LOCKED;
1721 	return (0);
1722 }
1723 
1724 /*
1725  * Unlock and wake up any waiters.
1726  */
1727 static void
1728 ccdunlock(struct ccd_s *cs)
1729 {
1730 
1731 	cs->sc_flags &= ~CCDF_LOCKED;
1732 	if ((cs->sc_flags & CCDF_WANTED) != 0) {
1733 		cs->sc_flags &= ~CCDF_WANTED;
1734 		wakeup(cs);
1735 	}
1736 }
1737 
1738 #ifdef DEBUG
1739 static void
1740 printiinfo(struct ccdiinfo *ii)
1741 {
1742 	int ix, i;
1743 
1744 	for (ix = 0; ii->ii_ndisk; ix++, ii++) {
1745 		printf(" itab[%d]: #dk %d sblk %d soff %d",
1746 		       ix, ii->ii_ndisk, ii->ii_startblk, ii->ii_startoff);
1747 		for (i = 0; i < ii->ii_ndisk; i++)
1748 			printf(" %d", ii->ii_index[i]);
1749 		printf("\n");
1750 	}
1751 }
1752 #endif
1753