xref: /netbsd-src/sys/dev/dkwedge/dk.c (revision 7fa608457b817eca6e0977b37f758ae064f3c99c)
1 /*	$NetBSD: dk.c,v 1.29 2007/10/08 16:41:11 ad Exp $	*/
2 
3 /*-
4  * Copyright (c) 2004, 2005, 2006, 2007 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.
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  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *	This product includes software developed by the NetBSD
21  *	Foundation, Inc. and its contributors.
22  * 4. Neither the name of The NetBSD Foundation nor the names of its
23  *    contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36  * POSSIBILITY OF SUCH DAMAGE.
37  */
38 
39 #include <sys/cdefs.h>
40 __KERNEL_RCSID(0, "$NetBSD: dk.c,v 1.29 2007/10/08 16:41:11 ad Exp $");
41 
42 #include "opt_dkwedge.h"
43 
44 #include <sys/param.h>
45 #include <sys/systm.h>
46 #include <sys/proc.h>
47 #include <sys/errno.h>
48 #include <sys/pool.h>
49 #include <sys/ioctl.h>
50 #include <sys/disklabel.h>
51 #include <sys/disk.h>
52 #include <sys/fcntl.h>
53 #include <sys/buf.h>
54 #include <sys/bufq.h>
55 #include <sys/vnode.h>
56 #include <sys/stat.h>
57 #include <sys/conf.h>
58 #include <sys/callout.h>
59 #include <sys/kernel.h>
60 #include <sys/malloc.h>
61 #include <sys/device.h>
62 #include <sys/kauth.h>
63 
64 #include <miscfs/specfs/specdev.h>
65 
66 MALLOC_DEFINE(M_DKWEDGE, "dkwedge", "Disk wedge structures");
67 
68 typedef enum {
69 	DKW_STATE_LARVAL	= 0,
70 	DKW_STATE_RUNNING	= 1,
71 	DKW_STATE_DYING		= 2,
72 	DKW_STATE_DEAD		= 666
73 } dkwedge_state_t;
74 
75 struct dkwedge_softc {
76 	struct device	*sc_dev;	/* pointer to our pseudo-device */
77 	struct cfdata	sc_cfdata;	/* our cfdata structure */
78 	uint8_t		sc_wname[128];	/* wedge name (Unicode, UTF-8) */
79 
80 	dkwedge_state_t sc_state;	/* state this wedge is in */
81 
82 	struct disk	*sc_parent;	/* parent disk */
83 	daddr_t		sc_offset;	/* LBA offset of wedge in parent */
84 	uint64_t	sc_size;	/* size of wedge in blocks */
85 	char		sc_ptype[32];	/* partition type */
86 	dev_t		sc_pdev;	/* cached parent's dev_t */
87 					/* link on parent's wedge list */
88 	LIST_ENTRY(dkwedge_softc) sc_plink;
89 
90 	struct disk	sc_dk;		/* our own disk structure */
91 	struct bufq_state *sc_bufq;	/* buffer queue */
92 	struct callout	sc_restart_ch;	/* callout to restart I/O */
93 
94 	u_int		sc_iopend;	/* I/Os pending */
95 	int		sc_flags;	/* flags (splbio) */
96 };
97 
98 #define	DK_F_WAIT_DRAIN		0x0001	/* waiting for I/O to drain */
99 
100 static void	dkstart(struct dkwedge_softc *);
101 static void	dkiodone(struct buf *);
102 static void	dkrestart(void *);
103 
104 static dev_type_open(dkopen);
105 static dev_type_close(dkclose);
106 static dev_type_read(dkread);
107 static dev_type_write(dkwrite);
108 static dev_type_ioctl(dkioctl);
109 static dev_type_strategy(dkstrategy);
110 static dev_type_dump(dkdump);
111 static dev_type_size(dksize);
112 
113 const struct bdevsw dk_bdevsw = {
114 	dkopen, dkclose, dkstrategy, dkioctl, dkdump, dksize, D_DISK
115 };
116 
117 const struct cdevsw dk_cdevsw = {
118 	dkopen, dkclose, dkread, dkwrite, dkioctl,
119 	    nostop, notty, nopoll, nommap, nokqfilter, D_DISK
120 };
121 
122 static struct dkwedge_softc **dkwedges;
123 static u_int ndkwedges;
124 static krwlock_t dkwedges_lock;
125 
126 static LIST_HEAD(, dkwedge_discovery_method) dkwedge_discovery_methods;
127 static krwlock_t dkwedge_discovery_methods_lock;
128 
129 /*
130  * dkwedge_match:
131  *
132  *	Autoconfiguration match function for pseudo-device glue.
133  */
134 static int
135 dkwedge_match(struct device *parent, struct cfdata *match,
136     void *aux)
137 {
138 
139 	/* Pseudo-device; always present. */
140 	return (1);
141 }
142 
143 /*
144  * dkwedge_attach:
145  *
146  *	Autoconfiguration attach function for pseudo-device glue.
147  */
148 static void
149 dkwedge_attach(struct device *parent, struct device *self,
150     void *aux)
151 {
152 
153 	/* Nothing to do. */
154 }
155 
156 /*
157  * dkwedge_detach:
158  *
159  *	Autoconfiguration detach function for pseudo-device glue.
160  */
161 static int
162 dkwedge_detach(struct device *self, int flags)
163 {
164 
165 	/* Always succeeds. */
166 	return (0);
167 }
168 
169 CFDRIVER_DECL(dk, DV_DISK, NULL);
170 CFATTACH_DECL(dk, sizeof(struct device),
171 	      dkwedge_match, dkwedge_attach, dkwedge_detach, NULL);
172 
173 /*
174  * dkwedge_wait_drain:
175  *
176  *	Wait for I/O on the wedge to drain.
177  *	NOTE: Must be called at splbio()!
178  */
179 static void
180 dkwedge_wait_drain(struct dkwedge_softc *sc)
181 {
182 
183 	while (sc->sc_iopend != 0) {
184 		sc->sc_flags |= DK_F_WAIT_DRAIN;
185 		(void) tsleep(&sc->sc_iopend, PRIBIO, "dkdrn", 0);
186 	}
187 }
188 
189 /*
190  * dkwedge_compute_pdev:
191  *
192  *	Compute the parent disk's dev_t.
193  */
194 static int
195 dkwedge_compute_pdev(const char *pname, dev_t *pdevp)
196 {
197 	const char *name, *cp;
198 	int punit, pmaj;
199 	char devname[16];
200 
201 	name = pname;
202 	if ((pmaj = devsw_name2blk(name, devname, sizeof(devname))) == -1)
203 		return (ENODEV);
204 
205 	name += strlen(devname);
206 	for (cp = name, punit = 0; *cp >= '0' && *cp <= '9'; cp++)
207 		punit = (punit * 10) + (*cp - '0');
208 	if (cp == name) {
209 		/* Invalid parent disk name. */
210 		return (ENODEV);
211 	}
212 
213 	*pdevp = MAKEDISKDEV(pmaj, punit, RAW_PART);
214 
215 	return (0);
216 }
217 
218 /*
219  * dkwedge_array_expand:
220  *
221  *	Expand the dkwedges array.
222  */
223 static void
224 dkwedge_array_expand(void)
225 {
226 	int newcnt = ndkwedges + 16;
227 	struct dkwedge_softc **newarray, **oldarray;
228 
229 	newarray = malloc(newcnt * sizeof(*newarray), M_DKWEDGE,
230 	    M_WAITOK|M_ZERO);
231 	if ((oldarray = dkwedges) != NULL)
232 		memcpy(newarray, dkwedges, ndkwedges * sizeof(*newarray));
233 	dkwedges = newarray;
234 	ndkwedges = newcnt;
235 	if (oldarray != NULL)
236 		free(oldarray, M_DKWEDGE);
237 }
238 
239 /*
240  * dkwedge_add:		[exported function]
241  *
242  *	Add a disk wedge based on the provided information.
243  *
244  *	The incoming dkw_devname[] is ignored, instead being
245  *	filled in and returned to the caller.
246  */
247 int
248 dkwedge_add(struct dkwedge_info *dkw)
249 {
250 	struct dkwedge_softc *sc, *lsc;
251 	struct disk *pdk;
252 	u_int unit;
253 	int error;
254 	dev_t pdev;
255 
256 	dkw->dkw_parent[sizeof(dkw->dkw_parent) - 1] = '\0';
257 	pdk = disk_find(dkw->dkw_parent);
258 	if (pdk == NULL)
259 		return (ENODEV);
260 
261 	error = dkwedge_compute_pdev(pdk->dk_name, &pdev);
262 	if (error)
263 		return (error);
264 
265 	if (dkw->dkw_offset < 0)
266 		return (EINVAL);
267 
268 	sc = malloc(sizeof(*sc), M_DKWEDGE, M_WAITOK|M_ZERO);
269 	sc->sc_state = DKW_STATE_LARVAL;
270 	sc->sc_parent = pdk;
271 	sc->sc_pdev = pdev;
272 	sc->sc_offset = dkw->dkw_offset;
273 	sc->sc_size = dkw->dkw_size;
274 
275 	memcpy(sc->sc_wname, dkw->dkw_wname, sizeof(sc->sc_wname));
276 	sc->sc_wname[sizeof(sc->sc_wname) - 1] = '\0';
277 
278 	memcpy(sc->sc_ptype, dkw->dkw_ptype, sizeof(sc->sc_ptype));
279 	sc->sc_ptype[sizeof(sc->sc_ptype) - 1] = '\0';
280 
281 	bufq_alloc(&sc->sc_bufq, "fcfs", 0);
282 
283 	callout_init(&sc->sc_restart_ch, 0);
284 	callout_setfunc(&sc->sc_restart_ch, dkrestart, sc);
285 
286 	/*
287 	 * Wedge will be added; increment the wedge count for the parent.
288 	 * Only allow this to happend if RAW_PART is the only thing open.
289 	 */
290 	mutex_enter(&pdk->dk_openlock);
291 	if (pdk->dk_openmask & ~(1 << RAW_PART))
292 		error = EBUSY;
293 	else {
294 		/* Check for wedge overlap. */
295 		LIST_FOREACH(lsc, &pdk->dk_wedges, sc_plink) {
296 			daddr_t lastblk = sc->sc_offset + sc->sc_size - 1;
297 			daddr_t llastblk = lsc->sc_offset + lsc->sc_size - 1;
298 
299 			if (sc->sc_offset >= lsc->sc_offset &&
300 			    sc->sc_offset <= llastblk) {
301 				/* Overlaps the tail of the exsiting wedge. */
302 				break;
303 			}
304 			if (lastblk >= lsc->sc_offset &&
305 			    lastblk <= llastblk) {
306 				/* Overlaps the head of the existing wedge. */
307 			    	break;
308 			}
309 		}
310 		if (lsc != NULL)
311 			error = EINVAL;
312 		else {
313 			pdk->dk_nwedges++;
314 			LIST_INSERT_HEAD(&pdk->dk_wedges, sc, sc_plink);
315 		}
316 	}
317 	mutex_exit(&pdk->dk_openlock);
318 	if (error) {
319 		bufq_free(sc->sc_bufq);
320 		free(sc, M_DKWEDGE);
321 		return (error);
322 	}
323 
324 	/* Fill in our cfdata for the pseudo-device glue. */
325 	sc->sc_cfdata.cf_name = dk_cd.cd_name;
326 	sc->sc_cfdata.cf_atname = dk_ca.ca_name;
327 	/* sc->sc_cfdata.cf_unit set below */
328 	sc->sc_cfdata.cf_fstate = FSTATE_STAR;
329 
330 	/* Insert the larval wedge into the array. */
331 	rw_enter(&dkwedges_lock, RW_WRITER);
332 	for (error = 0;;) {
333 		struct dkwedge_softc **scpp;
334 
335 		/*
336 		 * Check for a duplicate wname while searching for
337 		 * a slot.
338 		 */
339 		for (scpp = NULL, unit = 0; unit < ndkwedges; unit++) {
340 			if (dkwedges[unit] == NULL) {
341 				if (scpp == NULL) {
342 					scpp = &dkwedges[unit];
343 					sc->sc_cfdata.cf_unit = unit;
344 				}
345 			} else {
346 				/* XXX Unicode. */
347 				if (strcmp(dkwedges[unit]->sc_wname,
348 					   sc->sc_wname) == 0) {
349 					error = EEXIST;
350 					break;
351 				}
352 			}
353 		}
354 		if (error)
355 			break;
356 		KASSERT(unit == ndkwedges);
357 		if (scpp == NULL)
358 			dkwedge_array_expand();
359 		else {
360 			KASSERT(scpp == &dkwedges[sc->sc_cfdata.cf_unit]);
361 			*scpp = sc;
362 			break;
363 		}
364 	}
365 	rw_exit(&dkwedges_lock);
366 	if (error) {
367 		mutex_enter(&pdk->dk_openlock);
368 		pdk->dk_nwedges--;
369 		LIST_REMOVE(sc, sc_plink);
370 		mutex_exit(&pdk->dk_openlock);
371 
372 		bufq_free(sc->sc_bufq);
373 		free(sc, M_DKWEDGE);
374 		return (error);
375 	}
376 
377 	/*
378 	 * Now that we know the unit #, attach a pseudo-device for
379 	 * this wedge instance.  This will provide us with the
380 	 * "struct device" necessary for glue to other parts of the
381 	 * system.
382 	 *
383 	 * This should never fail, unless we're almost totally out of
384 	 * memory.
385 	 */
386 	if ((sc->sc_dev = config_attach_pseudo(&sc->sc_cfdata)) == NULL) {
387 		aprint_error("%s%u: unable to attach pseudo-device\n",
388 		    sc->sc_cfdata.cf_name, sc->sc_cfdata.cf_unit);
389 
390 		rw_enter(&dkwedges_lock, RW_WRITER);
391 		dkwedges[sc->sc_cfdata.cf_unit] = NULL;
392 		rw_exit(&dkwedges_lock);
393 
394 		mutex_enter(&pdk->dk_openlock);
395 		pdk->dk_nwedges--;
396 		LIST_REMOVE(sc, sc_plink);
397 		mutex_exit(&pdk->dk_openlock);
398 
399 		bufq_free(sc->sc_bufq);
400 		free(sc, M_DKWEDGE);
401 		return (ENOMEM);
402 	}
403 
404 	/* Return the devname to the caller. */
405 	strcpy(dkw->dkw_devname, sc->sc_dev->dv_xname);
406 
407 	/*
408 	 * XXX Really ought to make the disk_attach() and the changing
409 	 * of state to RUNNING atomic.
410 	 */
411 
412 	disk_init(&sc->sc_dk, sc->sc_dev->dv_xname, NULL);
413 	disk_attach(&sc->sc_dk);
414 
415 	/* Disk wedge is ready for use! */
416 	sc->sc_state = DKW_STATE_RUNNING;
417 
418 	/* Announce our arrival. */
419 	aprint_normal("%s at %s: %s\n", sc->sc_dev->dv_xname, pdk->dk_name,
420 	    sc->sc_wname);	/* XXX Unicode */
421 	aprint_normal("%s: %"PRIu64" blocks at %"PRId64", type: %s\n",
422 	    sc->sc_dev->dv_xname, sc->sc_size, sc->sc_offset, sc->sc_ptype);
423 
424 	return (0);
425 }
426 
427 /*
428  * dkwedge_del:		[exported function]
429  *
430  *	Delete a disk wedge based on the provided information.
431  *	NOTE: We look up the wedge based on the wedge devname,
432  *	not wname.
433  */
434 int
435 dkwedge_del(struct dkwedge_info *dkw)
436 {
437 	struct dkwedge_softc *sc = NULL;
438 	u_int unit;
439 	int bmaj, cmaj, s;
440 
441 	/* Find our softc. */
442 	dkw->dkw_devname[sizeof(dkw->dkw_devname) - 1] = '\0';
443 	rw_enter(&dkwedges_lock, RW_WRITER);
444 	for (unit = 0; unit < ndkwedges; unit++) {
445 		if ((sc = dkwedges[unit]) != NULL &&
446 		    strcmp(sc->sc_dev->dv_xname, dkw->dkw_devname) == 0 &&
447 		    strcmp(sc->sc_parent->dk_name, dkw->dkw_parent) == 0) {
448 			/* Mark the wedge as dying. */
449 			sc->sc_state = DKW_STATE_DYING;
450 			break;
451 		}
452 	}
453 	rw_exit(&dkwedges_lock);
454 	if (unit == ndkwedges)
455 		return (ESRCH);
456 
457 	KASSERT(sc != NULL);
458 
459 	/* Locate the wedge major numbers. */
460 	bmaj = bdevsw_lookup_major(&dk_bdevsw);
461 	cmaj = cdevsw_lookup_major(&dk_cdevsw);
462 
463 	/* Kill any pending restart. */
464 	callout_stop(&sc->sc_restart_ch);
465 
466 	/*
467 	 * dkstart() will kill any queued buffers now that the
468 	 * state of the wedge is not RUNNING.  Once we've done
469 	 * that, wait for any other pending I/O to complete.
470 	 */
471 	s = splbio();
472 	dkstart(sc);
473 	dkwedge_wait_drain(sc);
474 	splx(s);
475 
476 	/* Nuke the vnodes for any open instances. */
477 	vdevgone(bmaj, unit, unit, VBLK);
478 	vdevgone(cmaj, unit, unit, VCHR);
479 
480 	/* Clean up the parent. */
481 	mutex_enter(&sc->sc_dk.dk_openlock);
482 	mutex_enter(&sc->sc_parent->dk_rawlock);
483 	if (sc->sc_dk.dk_openmask) {
484 		if (sc->sc_parent->dk_rawopens-- == 1) {
485 			KASSERT(sc->sc_parent->dk_rawvp != NULL);
486 			(void) vn_close(sc->sc_parent->dk_rawvp, FREAD | FWRITE,
487 					NOCRED, curlwp);
488 			sc->sc_parent->dk_rawvp = NULL;
489 		}
490 		sc->sc_dk.dk_openmask = 0;
491 	}
492 	mutex_exit(&sc->sc_parent->dk_rawlock);
493 	mutex_exit(&sc->sc_dk.dk_openlock);
494 
495 	/* Announce our departure. */
496 	aprint_normal("%s at %s (%s) deleted\n", sc->sc_dev->dv_xname,
497 	    sc->sc_parent->dk_name,
498 	    sc->sc_wname);	/* XXX Unicode */
499 
500 	/* Delete our pseudo-device. */
501 	(void) config_detach(sc->sc_dev, DETACH_FORCE | DETACH_QUIET);
502 
503 	mutex_enter(&sc->sc_parent->dk_openlock);
504 	sc->sc_parent->dk_nwedges--;
505 	LIST_REMOVE(sc, sc_plink);
506 	mutex_exit(&sc->sc_parent->dk_openlock);
507 
508 	/* Delete our buffer queue. */
509 	bufq_free(sc->sc_bufq);
510 
511 	/* Detach from the disk list. */
512 	disk_detach(&sc->sc_dk);
513 
514 	/* Poof. */
515 	rw_enter(&dkwedges_lock, RW_WRITER);
516 	dkwedges[unit] = NULL;
517 	sc->sc_state = DKW_STATE_DEAD;
518 	rw_exit(&dkwedges_lock);
519 
520 	free(sc, M_DKWEDGE);
521 
522 	return (0);
523 }
524 
525 /*
526  * dkwedge_delall:	[exported function]
527  *
528  *	Delete all of the wedges on the specified disk.  Used when
529  *	a disk is being detached.
530  */
531 void
532 dkwedge_delall(struct disk *pdk)
533 {
534 	struct dkwedge_info dkw;
535 	struct dkwedge_softc *sc;
536 
537 	for (;;) {
538 		mutex_enter(&pdk->dk_openlock);
539 		if ((sc = LIST_FIRST(&pdk->dk_wedges)) == NULL) {
540 			KASSERT(pdk->dk_nwedges == 0);
541 			mutex_exit(&pdk->dk_openlock);
542 			return;
543 		}
544 		strcpy(dkw.dkw_parent, pdk->dk_name);
545 		strcpy(dkw.dkw_devname, sc->sc_dev->dv_xname);
546 		mutex_exit(&pdk->dk_openlock);
547 		(void) dkwedge_del(&dkw);
548 	}
549 }
550 
551 /*
552  * dkwedge_list:	[exported function]
553  *
554  *	List all of the wedges on a particular disk.
555  *	If p == NULL, the buffer is in kernel space.  Otherwise, it is
556  *	in user space of the specified process.
557  */
558 int
559 dkwedge_list(struct disk *pdk, struct dkwedge_list *dkwl, struct lwp *l)
560 {
561 	struct uio uio;
562 	struct iovec iov;
563 	struct dkwedge_softc *sc;
564 	struct dkwedge_info dkw;
565 	struct vmspace *vm;
566 	int error = 0;
567 
568 	iov.iov_base = dkwl->dkwl_buf;
569 	iov.iov_len = dkwl->dkwl_bufsize;
570 
571 	uio.uio_iov = &iov;
572 	uio.uio_iovcnt = 1;
573 	uio.uio_offset = 0;
574 	uio.uio_resid = dkwl->dkwl_bufsize;
575 	uio.uio_rw = UIO_READ;
576 	if (l == NULL) {
577 		UIO_SETUP_SYSSPACE(&uio);
578 	} else {
579 		error = proc_vmspace_getref(l->l_proc, &vm);
580 		if (error) {
581 			return error;
582 		}
583 		uio.uio_vmspace = vm;
584 	}
585 
586 	dkwl->dkwl_ncopied = 0;
587 
588 	mutex_enter(&pdk->dk_openlock);
589 	LIST_FOREACH(sc, &pdk->dk_wedges, sc_plink) {
590 		if (uio.uio_resid < sizeof(dkw))
591 			break;
592 
593 		if (sc->sc_state != DKW_STATE_RUNNING)
594 			continue;
595 
596 		strcpy(dkw.dkw_devname, sc->sc_dev->dv_xname);
597 		memcpy(dkw.dkw_wname, sc->sc_wname, sizeof(dkw.dkw_wname));
598 		dkw.dkw_wname[sizeof(dkw.dkw_wname) - 1] = '\0';
599 		strcpy(dkw.dkw_parent, sc->sc_parent->dk_name);
600 		dkw.dkw_offset = sc->sc_offset;
601 		dkw.dkw_size = sc->sc_size;
602 		strcpy(dkw.dkw_ptype, sc->sc_ptype);
603 
604 		error = uiomove(&dkw, sizeof(dkw), &uio);
605 		if (error)
606 			break;
607 		dkwl->dkwl_ncopied++;
608 	}
609 	dkwl->dkwl_nwedges = pdk->dk_nwedges;
610 	mutex_exit(&pdk->dk_openlock);
611 
612 	if (l != NULL) {
613 		uvmspace_free(vm);
614 	}
615 
616 	return (error);
617 }
618 
619 device_t
620 dkwedge_find_by_wname(const char *wname)
621 {
622 	device_t dv = NULL;
623 	struct dkwedge_softc *sc;
624 	int i;
625 
626 	rw_enter(&dkwedges_lock, RW_WRITER);
627 	for (i = 0; i < ndkwedges; i++) {
628 		if ((sc = dkwedges[i]) == NULL)
629 			continue;
630 		if (strcmp(sc->sc_wname, wname) == 0) {
631 			if (dv != NULL) {
632 				printf(
633 				    "WARNING: double match for wedge name %s "
634 				    "(%s, %s)\n", wname, device_xname(dv),
635 				    device_xname(sc->sc_dev));
636 				continue;
637 			}
638 			dv = sc->sc_dev;
639 		}
640 	}
641 	rw_exit(&dkwedges_lock);
642 	return dv;
643 }
644 
645 void
646 dkwedge_print_wnames(void)
647 {
648 	struct dkwedge_softc *sc;
649 	int i;
650 
651 	rw_enter(&dkwedges_lock, RW_WRITER);
652 	for (i = 0; i < ndkwedges; i++) {
653 		if ((sc = dkwedges[i]) == NULL)
654 			continue;
655 		printf(" wedge:%s", sc->sc_wname);
656 	}
657 	rw_exit(&dkwedges_lock);
658 }
659 
660 /*
661  * dkwedge_set_bootwedge
662  *
663  *	Set the booted_wedge global based on the specified parent name
664  *	and offset/length.
665  */
666 void
667 dkwedge_set_bootwedge(struct device *parent, daddr_t startblk, uint64_t nblks)
668 {
669 	struct dkwedge_softc *sc;
670 	int i;
671 
672 	rw_enter(&dkwedges_lock, RW_WRITER);
673 	for (i = 0; i < ndkwedges; i++) {
674 		if ((sc = dkwedges[i]) == NULL)
675 			continue;
676 		if (strcmp(sc->sc_parent->dk_name, parent->dv_xname) == 0 &&
677 		    sc->sc_offset == startblk &&
678 		    sc->sc_size == nblks) {
679 			if (booted_wedge) {
680 				printf("WARNING: double match for boot wedge "
681 				    "(%s, %s)\n",
682 				    booted_wedge->dv_xname,
683 				    sc->sc_dev->dv_xname);
684 				continue;
685 			}
686 			booted_device = parent;
687 			booted_wedge = sc->sc_dev;
688 			booted_partition = 0;
689 		}
690 	}
691 	/*
692 	 * XXX What if we don't find one?  Should we create a special
693 	 * XXX root wedge?
694 	 */
695 	rw_exit(&dkwedges_lock);
696 }
697 
698 /*
699  * We need a dummy object to stuff into the dkwedge discovery method link
700  * set to ensure that there is always at least one object in the set.
701  */
702 static struct dkwedge_discovery_method dummy_discovery_method;
703 __link_set_add_bss(dkwedge_methods, dummy_discovery_method);
704 
705 /*
706  * dkwedge_init:
707  *
708  *	Initialize the disk wedge subsystem.
709  */
710 void
711 dkwedge_init(void)
712 {
713 	__link_set_decl(dkwedge_methods, struct dkwedge_discovery_method);
714 	struct dkwedge_discovery_method * const *ddmp;
715 	struct dkwedge_discovery_method *lddm, *ddm;
716 
717 	rw_init(&dkwedges_lock);
718 	rw_init(&dkwedge_discovery_methods_lock);
719 
720 	if (config_cfdriver_attach(&dk_cd) != 0)
721 		panic("dkwedge: unable to attach cfdriver");
722 	if (config_cfattach_attach(dk_cd.cd_name, &dk_ca) != 0)
723 		panic("dkwedge: unable to attach cfattach");
724 
725 	rw_enter(&dkwedge_discovery_methods_lock, RW_WRITER);
726 
727 	LIST_INIT(&dkwedge_discovery_methods);
728 
729 	__link_set_foreach(ddmp, dkwedge_methods) {
730 		ddm = *ddmp;
731 		if (ddm == &dummy_discovery_method)
732 			continue;
733 		if (LIST_EMPTY(&dkwedge_discovery_methods)) {
734 			LIST_INSERT_HEAD(&dkwedge_discovery_methods,
735 					 ddm, ddm_list);
736 			continue;
737 		}
738 		LIST_FOREACH(lddm, &dkwedge_discovery_methods, ddm_list) {
739 			if (ddm->ddm_priority == lddm->ddm_priority) {
740 				aprint_error("dk-method-%s: method \"%s\" "
741 				    "already exists at priority %d\n",
742 				    ddm->ddm_name, lddm->ddm_name,
743 				    lddm->ddm_priority);
744 				/* Not inserted. */
745 				break;
746 			}
747 			if (ddm->ddm_priority < lddm->ddm_priority) {
748 				/* Higher priority; insert before. */
749 				LIST_INSERT_BEFORE(lddm, ddm, ddm_list);
750 				break;
751 			}
752 			if (LIST_NEXT(lddm, ddm_list) == NULL) {
753 				/* Last one; insert after. */
754 				KASSERT(lddm->ddm_priority < ddm->ddm_priority);
755 				LIST_INSERT_AFTER(lddm, ddm, ddm_list);
756 				break;
757 			}
758 		}
759 	}
760 
761 	rw_exit(&dkwedge_discovery_methods_lock);
762 }
763 
764 #ifdef DKWEDGE_AUTODISCOVER
765 int	dkwedge_autodiscover = 1;
766 #else
767 int	dkwedge_autodiscover = 0;
768 #endif
769 
770 /*
771  * dkwedge_discover:	[exported function]
772  *
773  *	Discover the wedges on a newly attached disk.
774  */
775 void
776 dkwedge_discover(struct disk *pdk)
777 {
778 	struct dkwedge_discovery_method *ddm;
779 	struct vnode *vp;
780 	int error;
781 	dev_t pdev;
782 
783 	/*
784 	 * Require people playing with wedges to enable this explicitly.
785 	 */
786 	if (dkwedge_autodiscover == 0)
787 		return;
788 
789 	rw_enter(&dkwedge_discovery_methods_lock, RW_READER);
790 
791 	error = dkwedge_compute_pdev(pdk->dk_name, &pdev);
792 	if (error) {
793 		aprint_error("%s: unable to compute pdev, error = %d\n",
794 		    pdk->dk_name, error);
795 		goto out;
796 	}
797 
798 	error = bdevvp(pdev, &vp);
799 	if (error) {
800 		aprint_error("%s: unable to find vnode for pdev, error = %d\n",
801 		    pdk->dk_name, error);
802 		goto out;
803 	}
804 
805 	error = vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
806 	if (error) {
807 		aprint_error("%s: unable to lock vnode for pdev, error = %d\n",
808 		    pdk->dk_name, error);
809 		vrele(vp);
810 		goto out;
811 	}
812 
813 	error = VOP_OPEN(vp, FREAD, NOCRED, 0);
814 	if (error) {
815 		aprint_error("%s: unable to open device, error = %d\n",
816 		    pdk->dk_name, error);
817 		vput(vp);
818 		goto out;
819 	}
820 	VOP_UNLOCK(vp, 0);
821 
822 	/*
823 	 * For each supported partition map type, look to see if
824 	 * this map type exists.  If so, parse it and add the
825 	 * corresponding wedges.
826 	 */
827 	LIST_FOREACH(ddm, &dkwedge_discovery_methods, ddm_list) {
828 		error = (*ddm->ddm_discover)(pdk, vp);
829 		if (error == 0) {
830 			/* Successfully created wedges; we're done. */
831 			break;
832 		}
833 	}
834 
835 	error = vn_close(vp, FREAD, NOCRED, curlwp);
836 	if (error) {
837 		aprint_error("%s: unable to close device, error = %d\n",
838 		    pdk->dk_name, error);
839 		/* We'll just assume the vnode has been cleaned up. */
840 	}
841  out:
842 	rw_exit(&dkwedge_discovery_methods_lock);
843 }
844 
845 /*
846  * dkwedge_read:
847  *
848  *	Read the some data from the specified disk, used for
849  *	partition discovery.
850  */
851 int
852 dkwedge_read(struct disk *pdk, struct vnode *vp, daddr_t blkno,
853     void *tbuf, size_t len)
854 {
855 	struct buf b;
856 
857 	BUF_INIT(&b);
858 
859 	b.b_vp = vp;
860 	b.b_dev = vp->v_rdev;
861 	b.b_blkno = blkno;
862 	b.b_bcount = b.b_resid = len;
863 	b.b_flags = B_READ;
864 	b.b_proc = curproc;
865 	b.b_data = tbuf;
866 
867 	VOP_STRATEGY(vp, &b);
868 	return (biowait(&b));
869 }
870 
871 /*
872  * dkwedge_lookup:
873  *
874  *	Look up a dkwedge_softc based on the provided dev_t.
875  */
876 static struct dkwedge_softc *
877 dkwedge_lookup(dev_t dev)
878 {
879 	int unit = minor(dev);
880 
881 	if (unit >= ndkwedges)
882 		return (NULL);
883 
884 	KASSERT(dkwedges != NULL);
885 
886 	return (dkwedges[unit]);
887 }
888 
889 /*
890  * dkopen:		[devsw entry point]
891  *
892  *	Open a wedge.
893  */
894 static int
895 dkopen(dev_t dev, int flags, int fmt, struct lwp *l)
896 {
897 	struct dkwedge_softc *sc = dkwedge_lookup(dev);
898 	struct vnode *vp;
899 	int error = 0;
900 
901 	if (sc == NULL)
902 		return (ENODEV);
903 
904 	if (sc->sc_state != DKW_STATE_RUNNING)
905 		return (ENXIO);
906 
907 	/*
908 	 * We go through a complicated little dance to only open the parent
909 	 * vnode once per wedge, no matter how many times the wedge is
910 	 * opened.  The reason?  We see one dkopen() per open call, but
911 	 * only dkclose() on the last close.
912 	 */
913 	mutex_enter(&sc->sc_dk.dk_openlock);
914 	mutex_enter(&sc->sc_parent->dk_rawlock);
915 	if (sc->sc_dk.dk_openmask == 0) {
916 		if (sc->sc_parent->dk_rawopens == 0) {
917 			KASSERT(sc->sc_parent->dk_rawvp == NULL);
918 			error = bdevvp(sc->sc_pdev, &vp);
919 			if (error)
920 				goto popen_fail;
921 			error = vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
922 			if (error) {
923 				vrele(vp);
924 				goto popen_fail;
925 			}
926 			error = VOP_OPEN(vp, FREAD | FWRITE, NOCRED, 0);
927 			if (error) {
928 				vput(vp);
929 				goto popen_fail;
930 			}
931 			/* VOP_OPEN() doesn't do this for us. */
932 			vp->v_writecount++;
933 			VOP_UNLOCK(vp, 0);
934 			sc->sc_parent->dk_rawvp = vp;
935 		}
936 		sc->sc_parent->dk_rawopens++;
937 	}
938 	if (fmt == S_IFCHR)
939 		sc->sc_dk.dk_copenmask |= 1;
940 	else
941 		sc->sc_dk.dk_bopenmask |= 1;
942 	sc->sc_dk.dk_openmask =
943 	    sc->sc_dk.dk_copenmask | sc->sc_dk.dk_bopenmask;
944 
945  popen_fail:
946 	mutex_exit(&sc->sc_parent->dk_rawlock);
947 	mutex_exit(&sc->sc_dk.dk_openlock);
948 	return (error);
949 }
950 
951 /*
952  * dkclose:		[devsw entry point]
953  *
954  *	Close a wedge.
955  */
956 static int
957 dkclose(dev_t dev, int flags, int fmt, struct lwp *l)
958 {
959 	struct dkwedge_softc *sc = dkwedge_lookup(dev);
960 	int error = 0;
961 
962 	KASSERT(sc->sc_dk.dk_openmask != 0);
963 
964 	mutex_enter(&sc->sc_dk.dk_openlock);
965 	mutex_enter(&sc->sc_parent->dk_rawlock);
966 
967 	if (fmt == S_IFCHR)
968 		sc->sc_dk.dk_copenmask &= ~1;
969 	else
970 		sc->sc_dk.dk_bopenmask &= ~1;
971 	sc->sc_dk.dk_openmask =
972 	    sc->sc_dk.dk_copenmask | sc->sc_dk.dk_bopenmask;
973 
974 	if (sc->sc_dk.dk_openmask == 0) {
975 		if (sc->sc_parent->dk_rawopens-- == 1) {
976 			KASSERT(sc->sc_parent->dk_rawvp != NULL);
977 			error = vn_close(sc->sc_parent->dk_rawvp,
978 					 FREAD | FWRITE, NOCRED, l);
979 			sc->sc_parent->dk_rawvp = NULL;
980 		}
981 	}
982 
983 	mutex_exit(&sc->sc_parent->dk_rawlock);
984 	mutex_exit(&sc->sc_dk.dk_openlock);
985 
986 	return (error);
987 }
988 
989 /*
990  * dkstragegy:		[devsw entry point]
991  *
992  *	Perform I/O based on the wedge I/O strategy.
993  */
994 static void
995 dkstrategy(struct buf *bp)
996 {
997 	struct dkwedge_softc *sc = dkwedge_lookup(bp->b_dev);
998 	int s;
999 
1000 	if (sc->sc_state != DKW_STATE_RUNNING) {
1001 		bp->b_error = ENXIO;
1002 		goto done;
1003 	}
1004 
1005 	/* If it's an empty transfer, wake up the top half now. */
1006 	if (bp->b_bcount == 0)
1007 		goto done;
1008 
1009 	/* Make sure it's in-range. */
1010 	if (bounds_check_with_mediasize(bp, DEV_BSIZE, sc->sc_size) <= 0)
1011 		goto done;
1012 
1013 	/* Translate it to the parent's raw LBA. */
1014 	bp->b_rawblkno = bp->b_blkno + sc->sc_offset;
1015 
1016 	/* Place it in the queue and start I/O on the unit. */
1017 	s = splbio();
1018 	sc->sc_iopend++;
1019 	BUFQ_PUT(sc->sc_bufq, bp);
1020 	dkstart(sc);
1021 	splx(s);
1022 	return;
1023 
1024  done:
1025 	bp->b_resid = bp->b_bcount;
1026 	biodone(bp);
1027 }
1028 
1029 /*
1030  * dkstart:
1031  *
1032  *	Start I/O that has been enqueued on the wedge.
1033  *	NOTE: Must be called at splbio()!
1034  */
1035 static void
1036 dkstart(struct dkwedge_softc *sc)
1037 {
1038 	struct buf *bp, *nbp;
1039 
1040 	/* Do as much work as has been enqueued. */
1041 	while ((bp = BUFQ_PEEK(sc->sc_bufq)) != NULL) {
1042 		if (sc->sc_state != DKW_STATE_RUNNING) {
1043 			(void) BUFQ_GET(sc->sc_bufq);
1044 			if (sc->sc_iopend-- == 1 &&
1045 			    (sc->sc_flags & DK_F_WAIT_DRAIN) != 0) {
1046 				sc->sc_flags &= ~DK_F_WAIT_DRAIN;
1047 				wakeup(&sc->sc_iopend);
1048 			}
1049 			bp->b_error = ENXIO;
1050 			bp->b_resid = bp->b_bcount;
1051 			biodone(bp);
1052 		}
1053 
1054 		/* Instrumentation. */
1055 		disk_busy(&sc->sc_dk);
1056 
1057 		nbp = getiobuf_nowait();
1058 		if (nbp == NULL) {
1059 			/*
1060 			 * No resources to run this request; leave the
1061 			 * buffer queued up, and schedule a timer to
1062 			 * restart the queue in 1/2 a second.
1063 			 */
1064 			disk_unbusy(&sc->sc_dk, 0, bp->b_flags & B_READ);
1065 			callout_schedule(&sc->sc_restart_ch, hz / 2);
1066 			return;
1067 		}
1068 
1069 		(void) BUFQ_GET(sc->sc_bufq);
1070 
1071 		BUF_INIT(nbp);
1072 		nbp->b_data = bp->b_data;
1073 		nbp->b_flags = bp->b_flags | B_CALL;
1074 		nbp->b_iodone = dkiodone;
1075 		nbp->b_proc = bp->b_proc;
1076 		nbp->b_blkno = bp->b_rawblkno;
1077 		nbp->b_dev = sc->sc_parent->dk_rawvp->v_rdev;
1078 		nbp->b_vp = sc->sc_parent->dk_rawvp;
1079 		nbp->b_bcount = bp->b_bcount;
1080 		nbp->b_private = bp;
1081 		BIO_COPYPRIO(nbp, bp);
1082 
1083 		if ((nbp->b_flags & B_READ) == 0)
1084 			V_INCR_NUMOUTPUT(nbp->b_vp);
1085 		VOP_STRATEGY(nbp->b_vp, nbp);
1086 	}
1087 }
1088 
1089 /*
1090  * dkiodone:
1091  *
1092  *	I/O to a wedge has completed; alert the top half.
1093  *	NOTE: Must be called at splbio()!
1094  */
1095 static void
1096 dkiodone(struct buf *bp)
1097 {
1098 	struct buf *obp = bp->b_private;
1099 	struct dkwedge_softc *sc = dkwedge_lookup(obp->b_dev);
1100 
1101 	if (bp->b_error != 0)
1102 		obp->b_error = bp->b_error;
1103 	obp->b_resid = bp->b_resid;
1104 	putiobuf(bp);
1105 
1106 	if (sc->sc_iopend-- == 1 && (sc->sc_flags & DK_F_WAIT_DRAIN) != 0) {
1107 		sc->sc_flags &= ~DK_F_WAIT_DRAIN;
1108 		wakeup(&sc->sc_iopend);
1109 	}
1110 
1111 	disk_unbusy(&sc->sc_dk, obp->b_bcount - obp->b_resid,
1112 	    obp->b_flags & B_READ);
1113 
1114 	biodone(obp);
1115 
1116 	/* Kick the queue in case there is more work we can do. */
1117 	dkstart(sc);
1118 }
1119 
1120 /*
1121  * dkrestart:
1122  *
1123  *	Restart the work queue after it was stalled due to
1124  *	a resource shortage.  Invoked via a callout.
1125  */
1126 static void
1127 dkrestart(void *v)
1128 {
1129 	struct dkwedge_softc *sc = v;
1130 	int s;
1131 
1132 	s = splbio();
1133 	dkstart(sc);
1134 	splx(s);
1135 }
1136 
1137 /*
1138  * dkread:		[devsw entry point]
1139  *
1140  *	Read from a wedge.
1141  */
1142 static int
1143 dkread(dev_t dev, struct uio *uio, int flags)
1144 {
1145 	struct dkwedge_softc *sc = dkwedge_lookup(dev);
1146 
1147 	if (sc->sc_state != DKW_STATE_RUNNING)
1148 		return (ENXIO);
1149 
1150 	return (physio(dkstrategy, NULL, dev, B_READ,
1151 		       sc->sc_parent->dk_driver->d_minphys, uio));
1152 }
1153 
1154 /*
1155  * dkwrite:		[devsw entry point]
1156  *
1157  *	Write to a wedge.
1158  */
1159 static int
1160 dkwrite(dev_t dev, struct uio *uio, int flags)
1161 {
1162 	struct dkwedge_softc *sc = dkwedge_lookup(dev);
1163 
1164 	if (sc->sc_state != DKW_STATE_RUNNING)
1165 		return (ENXIO);
1166 
1167 	return (physio(dkstrategy, NULL, dev, B_WRITE,
1168 		       sc->sc_parent->dk_driver->d_minphys, uio));
1169 }
1170 
1171 /*
1172  * dkioctl:		[devsw entry point]
1173  *
1174  *	Perform an ioctl request on a wedge.
1175  */
1176 static int
1177 dkioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
1178 {
1179 	struct dkwedge_softc *sc = dkwedge_lookup(dev);
1180 	int error = 0;
1181 
1182 	if (sc->sc_state != DKW_STATE_RUNNING)
1183 		return (ENXIO);
1184 
1185 	switch (cmd) {
1186 	case DIOCCACHESYNC:
1187 		/*
1188 		 * XXX Do we really need to care about having a writable
1189 		 * file descriptor here?
1190 		 */
1191 		if ((flag & FWRITE) == 0)
1192 			error = EBADF;
1193 		else
1194 			error = VOP_IOCTL(sc->sc_parent->dk_rawvp,
1195 					  cmd, data, flag,
1196 					  l != NULL ? l->l_cred : NOCRED, l);
1197 		break;
1198 	case DIOCGWEDGEINFO:
1199 	    {
1200 	    	struct dkwedge_info *dkw = (void *) data;
1201 
1202 		strcpy(dkw->dkw_devname, sc->sc_dev->dv_xname);
1203 	    	memcpy(dkw->dkw_wname, sc->sc_wname, sizeof(dkw->dkw_wname));
1204 		dkw->dkw_wname[sizeof(dkw->dkw_wname) - 1] = '\0';
1205 		strcpy(dkw->dkw_parent, sc->sc_parent->dk_name);
1206 		dkw->dkw_offset = sc->sc_offset;
1207 		dkw->dkw_size = sc->sc_size;
1208 		strcpy(dkw->dkw_ptype, sc->sc_ptype);
1209 
1210 		break;
1211 	    }
1212 
1213 	default:
1214 		error = ENOTTY;
1215 	}
1216 
1217 	return (error);
1218 }
1219 
1220 /*
1221  * dksize:		[devsw entry point]
1222  *
1223  *	Query the size of a wedge for the purpose of performing a dump
1224  *	or for swapping to.
1225  */
1226 static int
1227 dksize(dev_t dev)
1228 {
1229 	struct dkwedge_softc *sc = dkwedge_lookup(dev);
1230 	int rv = -1;
1231 
1232 	if (sc == NULL)
1233 		return (-1);
1234 
1235 	if (sc->sc_state != DKW_STATE_RUNNING)
1236 		return (ENXIO);
1237 
1238 	mutex_enter(&sc->sc_dk.dk_openlock);
1239 	mutex_enter(&sc->sc_parent->dk_rawlock);
1240 
1241 	/* Our content type is static, no need to open the device. */
1242 
1243 	if (strcmp(sc->sc_ptype, DKW_PTYPE_SWAP) == 0) {
1244 		/* Saturate if we are larger than INT_MAX. */
1245 		if (sc->sc_size > INT_MAX)
1246 			rv = INT_MAX;
1247 		else
1248 			rv = (int) sc->sc_size;
1249 	}
1250 
1251 	mutex_exit(&sc->sc_parent->dk_rawlock);
1252 	mutex_exit(&sc->sc_dk.dk_openlock);
1253 
1254 	return (rv);
1255 }
1256 
1257 /*
1258  * dkdump:		[devsw entry point]
1259  *
1260  *	Perform a crash dump to a wedge.
1261  */
1262 static int
1263 dkdump(dev_t dev, daddr_t blkno, void *va, size_t size)
1264 {
1265 	struct dkwedge_softc *sc = dkwedge_lookup(dev);
1266 	const struct bdevsw *bdev;
1267 	int rv = 0;
1268 
1269 	if (sc == NULL)
1270 		return (-1);
1271 
1272 	if (sc->sc_state != DKW_STATE_RUNNING)
1273 		return (ENXIO);
1274 
1275 	mutex_enter(&sc->sc_dk.dk_openlock);
1276 	mutex_enter(&sc->sc_parent->dk_rawlock);
1277 
1278 	/* Our content type is static, no need to open the device. */
1279 
1280 	if (strcmp(sc->sc_ptype, DKW_PTYPE_SWAP) != 0) {
1281 		rv = ENXIO;
1282 		goto out;
1283 	}
1284 	if (size % DEV_BSIZE != 0) {
1285 		rv = EINVAL;
1286 		goto out;
1287 	}
1288 	if (blkno + size / DEV_BSIZE > sc->sc_size) {
1289 		printf("%s: blkno (%" PRIu64 ") + size / DEV_BSIZE (%zu) > "
1290 		    "sc->sc_size (%" PRIu64 ")\n", __func__, blkno,
1291 		    size / DEV_BSIZE, sc->sc_size);
1292 		rv = EINVAL;
1293 		goto out;
1294 	}
1295 
1296 	bdev = bdevsw_lookup(sc->sc_pdev);
1297 	rv = (*bdev->d_dump)(sc->sc_pdev, blkno + sc->sc_offset, va, size);
1298 
1299 out:
1300 	mutex_exit(&sc->sc_parent->dk_rawlock);
1301 	mutex_exit(&sc->sc_dk.dk_openlock);
1302 
1303 	return rv;
1304 }
1305