xref: /netbsd-src/sys/dev/dkwedge/dk.c (revision 2e4b9f2ad5e075f1be756443e3c06bb351c21a0e)
1 /*	$NetBSD: dk.c,v 1.171 2023/05/22 15:00:17 riastradh 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  *
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 #include <sys/cdefs.h>
33 __KERNEL_RCSID(0, "$NetBSD: dk.c,v 1.171 2023/05/22 15:00:17 riastradh Exp $");
34 
35 #ifdef _KERNEL_OPT
36 #include "opt_dkwedge.h"
37 #endif
38 
39 #include <sys/param.h>
40 #include <sys/types.h>
41 
42 #include <sys/buf.h>
43 #include <sys/bufq.h>
44 #include <sys/callout.h>
45 #include <sys/conf.h>
46 #include <sys/device.h>
47 #include <sys/disk.h>
48 #include <sys/disklabel.h>
49 #include <sys/errno.h>
50 #include <sys/fcntl.h>
51 #include <sys/ioctl.h>
52 #include <sys/kauth.h>
53 #include <sys/kernel.h>
54 #include <sys/malloc.h>
55 #include <sys/pool.h>
56 #include <sys/proc.h>
57 #include <sys/rwlock.h>
58 #include <sys/stat.h>
59 #include <sys/systm.h>
60 #include <sys/vnode.h>
61 
62 #include <miscfs/specfs/specdev.h>
63 
64 MALLOC_DEFINE(M_DKWEDGE, "dkwedge", "Disk wedge structures");
65 
66 typedef enum {
67 	DKW_STATE_LARVAL	= 0,
68 	DKW_STATE_RUNNING	= 1,
69 	DKW_STATE_DYING		= 2,
70 	DKW_STATE_DEAD		= 666
71 } dkwedge_state_t;
72 
73 /*
74  * Lock order:
75  *
76  *	sc->sc_dk.dk_openlock
77  *	=> sc->sc_parent->dk_rawlock
78  *	=> sc->sc_parent->dk_openlock
79  *	=> dkwedges_lock
80  *	=> sc->sc_sizelock
81  *
82  * Locking notes:
83  *
84  *	W	dkwedges_lock
85  *	D	device reference
86  *	O	sc->sc_dk.dk_openlock
87  *	P	sc->sc_parent->dk_openlock
88  *	R	sc->sc_parent->dk_rawlock
89  *	S	sc->sc_sizelock
90  *	I	sc->sc_iolock
91  *	$	stable after initialization
92  *	1	used only by a single thread
93  *
94  * x&y means both x and y must be held to write (with a write lock if
95  * one is rwlock), and either x or y must be held to read.
96  */
97 
98 struct dkwedge_softc {
99 	device_t	sc_dev;	/* P&W: pointer to our pseudo-device */
100 		/* sc_dev is also stable while device is referenced */
101 	struct cfdata	sc_cfdata;	/* 1: our cfdata structure */
102 	uint8_t		sc_wname[128];	/* $: wedge name (Unicode, UTF-8) */
103 
104 	dkwedge_state_t sc_state;	/* state this wedge is in */
105 		/* stable while device is referenced */
106 		/* used only in assertions when stable, and in dump in ddb */
107 
108 	struct disk	*sc_parent;	/* $: parent disk */
109 		/* P: sc_parent->dk_openmask */
110 		/* P: sc_parent->dk_nwedges */
111 		/* P: sc_parent->dk_wedges */
112 		/* R: sc_parent->dk_rawopens */
113 		/* R: sc_parent->dk_rawvp (also stable while wedge is open) */
114 	daddr_t		sc_offset;	/* $: LBA offset of wedge in parent */
115 	krwlock_t	sc_sizelock;
116 	uint64_t	sc_size;	/* S: size of wedge in blocks */
117 	char		sc_ptype[32];	/* $: partition type */
118 	dev_t		sc_pdev;	/* $: cached parent's dev_t */
119 					/* P: link on parent's wedge list */
120 	LIST_ENTRY(dkwedge_softc) sc_plink;
121 
122 	struct disk	sc_dk;		/* our own disk structure */
123 		/* O&R: sc_dk.dk_bopenmask */
124 		/* O&R: sc_dk.dk_copenmask */
125 		/* O&R: sc_dk.dk_openmask */
126 	struct bufq_state *sc_bufq;	/* $: buffer queue */
127 	struct callout	sc_restart_ch;	/* I: callout to restart I/O */
128 
129 	kmutex_t	sc_iolock;
130 	bool		sc_iostop;	/* I: don't schedule restart */
131 	int		sc_mode;	/* O&R: parent open mode */
132 };
133 
134 static int	dkwedge_match(device_t, cfdata_t, void *);
135 static void	dkwedge_attach(device_t, device_t, void *);
136 static int	dkwedge_detach(device_t, int);
137 
138 static void	dk_set_geometry(struct dkwedge_softc *, struct disk *);
139 
140 static void	dkstart(struct dkwedge_softc *);
141 static void	dkiodone(struct buf *);
142 static void	dkrestart(void *);
143 static void	dkminphys(struct buf *);
144 
145 static int	dkfirstopen(struct dkwedge_softc *, int);
146 static void	dklastclose(struct dkwedge_softc *);
147 static int	dkwedge_detach(device_t, int);
148 static void	dkwedge_delall1(struct disk *, bool);
149 static int	dkwedge_del1(struct dkwedge_info *, int);
150 static int	dk_open_parent(dev_t, int, struct vnode **);
151 static int	dk_close_parent(struct vnode *, int);
152 
153 static dev_type_open(dkopen);
154 static dev_type_close(dkclose);
155 static dev_type_cancel(dkcancel);
156 static dev_type_read(dkread);
157 static dev_type_write(dkwrite);
158 static dev_type_ioctl(dkioctl);
159 static dev_type_strategy(dkstrategy);
160 static dev_type_dump(dkdump);
161 static dev_type_size(dksize);
162 static dev_type_discard(dkdiscard);
163 
164 CFDRIVER_DECL(dk, DV_DISK, NULL);
165 CFATTACH_DECL3_NEW(dk, 0,
166     dkwedge_match, dkwedge_attach, dkwedge_detach, NULL, NULL, NULL,
167     DVF_DETACH_SHUTDOWN);
168 
169 const struct bdevsw dk_bdevsw = {
170 	.d_open = dkopen,
171 	.d_close = dkclose,
172 	.d_cancel = dkcancel,
173 	.d_strategy = dkstrategy,
174 	.d_ioctl = dkioctl,
175 	.d_dump = dkdump,
176 	.d_psize = dksize,
177 	.d_discard = dkdiscard,
178 	.d_cfdriver = &dk_cd,
179 	.d_devtounit = dev_minor_unit,
180 	.d_flag = D_DISK | D_MPSAFE
181 };
182 
183 const struct cdevsw dk_cdevsw = {
184 	.d_open = dkopen,
185 	.d_close = dkclose,
186 	.d_cancel = dkcancel,
187 	.d_read = dkread,
188 	.d_write = dkwrite,
189 	.d_ioctl = dkioctl,
190 	.d_stop = nostop,
191 	.d_tty = notty,
192 	.d_poll = nopoll,
193 	.d_mmap = nommap,
194 	.d_kqfilter = nokqfilter,
195 	.d_discard = dkdiscard,
196 	.d_cfdriver = &dk_cd,
197 	.d_devtounit = dev_minor_unit,
198 	.d_flag = D_DISK | D_MPSAFE
199 };
200 
201 static struct dkwedge_softc **dkwedges;
202 static u_int ndkwedges;
203 static krwlock_t dkwedges_lock;
204 
205 static LIST_HEAD(, dkwedge_discovery_method) dkwedge_discovery_methods;
206 static krwlock_t dkwedge_discovery_methods_lock;
207 
208 /*
209  * dkwedge_match:
210  *
211  *	Autoconfiguration match function for pseudo-device glue.
212  */
213 static int
dkwedge_match(device_t parent,cfdata_t match,void * aux)214 dkwedge_match(device_t parent, cfdata_t match, void *aux)
215 {
216 
217 	/* Pseudo-device; always present. */
218 	return 1;
219 }
220 
221 /*
222  * dkwedge_attach:
223  *
224  *	Autoconfiguration attach function for pseudo-device glue.
225  */
226 static void
dkwedge_attach(device_t parent,device_t self,void * aux)227 dkwedge_attach(device_t parent, device_t self, void *aux)
228 {
229 	struct dkwedge_softc *sc = aux;
230 	struct disk *pdk = sc->sc_parent;
231 	int unit = device_unit(self);
232 
233 	KASSERTMSG(unit >= 0, "unit=%d", unit);
234 
235 	if (!pmf_device_register(self, NULL, NULL))
236 		aprint_error_dev(self, "couldn't establish power handler\n");
237 
238 	mutex_enter(&pdk->dk_openlock);
239 	rw_enter(&dkwedges_lock, RW_WRITER);
240 	KASSERTMSG(unit < ndkwedges, "unit=%d ndkwedges=%u", unit, ndkwedges);
241 	KASSERTMSG(sc == dkwedges[unit], "sc=%p dkwedges[%d]=%p",
242 	    sc, unit, dkwedges[unit]);
243 	KASSERTMSG(sc->sc_dev == NULL, "sc=%p sc->sc_dev=%p", sc, sc->sc_dev);
244 	sc->sc_dev = self;
245 	rw_exit(&dkwedges_lock);
246 	mutex_exit(&pdk->dk_openlock);
247 
248 	disk_init(&sc->sc_dk, device_xname(sc->sc_dev), NULL);
249 	mutex_enter(&pdk->dk_openlock);
250 	dk_set_geometry(sc, pdk);
251 	mutex_exit(&pdk->dk_openlock);
252 	disk_attach(&sc->sc_dk);
253 
254 	/* Disk wedge is ready for use! */
255 	device_set_private(self, sc);
256 	sc->sc_state = DKW_STATE_RUNNING;
257 }
258 
259 /*
260  * dkwedge_compute_pdev:
261  *
262  *	Compute the parent disk's dev_t.
263  */
264 static int
dkwedge_compute_pdev(const char * pname,dev_t * pdevp,enum vtype type)265 dkwedge_compute_pdev(const char *pname, dev_t *pdevp, enum vtype type)
266 {
267 	const char *name, *cp;
268 	devmajor_t pmaj;
269 	int punit;
270 	char devname[16];
271 
272 	name = pname;
273 	switch (type) {
274 	case VBLK:
275 		pmaj = devsw_name2blk(name, devname, sizeof(devname));
276 		break;
277 	case VCHR:
278 		pmaj = devsw_name2chr(name, devname, sizeof(devname));
279 		break;
280 	default:
281 		pmaj = NODEVMAJOR;
282 		break;
283 	}
284 	if (pmaj == NODEVMAJOR)
285 		return ENXIO;
286 
287 	name += strlen(devname);
288 	for (cp = name, punit = 0; *cp >= '0' && *cp <= '9'; cp++)
289 		punit = (punit * 10) + (*cp - '0');
290 	if (cp == name) {
291 		/* Invalid parent disk name. */
292 		return ENXIO;
293 	}
294 
295 	*pdevp = MAKEDISKDEV(pmaj, punit, RAW_PART);
296 
297 	return 0;
298 }
299 
300 /*
301  * dkwedge_array_expand:
302  *
303  *	Expand the dkwedges array.
304  *
305  *	Releases and reacquires dkwedges_lock as a writer.
306  */
307 static int
dkwedge_array_expand(void)308 dkwedge_array_expand(void)
309 {
310 
311 	const unsigned incr = 16;
312 	unsigned newcnt, oldcnt;
313 	struct dkwedge_softc **newarray = NULL, **oldarray = NULL;
314 
315 	KASSERT(rw_write_held(&dkwedges_lock));
316 
317 	oldcnt = ndkwedges;
318 	oldarray = dkwedges;
319 
320 	if (oldcnt >= INT_MAX - incr)
321 		return ENFILE;	/* XXX */
322 	newcnt = oldcnt + incr;
323 
324 	rw_exit(&dkwedges_lock);
325 	newarray = malloc(newcnt * sizeof(*newarray), M_DKWEDGE,
326 	    M_WAITOK|M_ZERO);
327 	rw_enter(&dkwedges_lock, RW_WRITER);
328 
329 	if (ndkwedges != oldcnt || dkwedges != oldarray) {
330 		oldarray = NULL; /* already recycled */
331 		goto out;
332 	}
333 
334 	if (oldarray != NULL)
335 		memcpy(newarray, dkwedges, ndkwedges * sizeof(*newarray));
336 	dkwedges = newarray;
337 	newarray = NULL;	/* transferred to dkwedges */
338 	ndkwedges = newcnt;
339 
340 out:	rw_exit(&dkwedges_lock);
341 	if (oldarray != NULL)
342 		free(oldarray, M_DKWEDGE);
343 	if (newarray != NULL)
344 		free(newarray, M_DKWEDGE);
345 	rw_enter(&dkwedges_lock, RW_WRITER);
346 	return 0;
347 }
348 
349 static void
dkwedge_size_init(struct dkwedge_softc * sc,uint64_t size)350 dkwedge_size_init(struct dkwedge_softc *sc, uint64_t size)
351 {
352 
353 	rw_init(&sc->sc_sizelock);
354 	sc->sc_size = size;
355 }
356 
357 static void
dkwedge_size_fini(struct dkwedge_softc * sc)358 dkwedge_size_fini(struct dkwedge_softc *sc)
359 {
360 
361 	rw_destroy(&sc->sc_sizelock);
362 }
363 
364 static uint64_t
dkwedge_size(struct dkwedge_softc * sc)365 dkwedge_size(struct dkwedge_softc *sc)
366 {
367 	uint64_t size;
368 
369 	rw_enter(&sc->sc_sizelock, RW_READER);
370 	size = sc->sc_size;
371 	rw_exit(&sc->sc_sizelock);
372 
373 	return size;
374 }
375 
376 static void
dkwedge_size_increase(struct dkwedge_softc * sc,uint64_t size)377 dkwedge_size_increase(struct dkwedge_softc *sc, uint64_t size)
378 {
379 
380 	KASSERT(mutex_owned(&sc->sc_parent->dk_openlock));
381 
382 	rw_enter(&sc->sc_sizelock, RW_WRITER);
383 	KASSERTMSG(size >= sc->sc_size,
384 	    "decreasing dkwedge size from %"PRIu64" to %"PRIu64,
385 	    sc->sc_size, size);
386 	sc->sc_size = size;
387 	rw_exit(&sc->sc_sizelock);
388 }
389 
390 static void
dk_set_geometry(struct dkwedge_softc * sc,struct disk * pdk)391 dk_set_geometry(struct dkwedge_softc *sc, struct disk *pdk)
392 {
393 	struct disk *dk = &sc->sc_dk;
394 	struct disk_geom *dg = &dk->dk_geom;
395 
396 	KASSERT(mutex_owned(&pdk->dk_openlock));
397 
398 	memset(dg, 0, sizeof(*dg));
399 
400 	dg->dg_secperunit = dkwedge_size(sc);
401 	dg->dg_secsize = DEV_BSIZE << pdk->dk_blkshift;
402 
403 	/* fake numbers, 1 cylinder is 1 MB with default sector size */
404 	dg->dg_nsectors = 32;
405 	dg->dg_ntracks = 64;
406 	dg->dg_ncylinders =
407 	    dg->dg_secperunit / (dg->dg_nsectors * dg->dg_ntracks);
408 
409 	disk_set_info(sc->sc_dev, dk, NULL);
410 }
411 
412 /*
413  * dkwedge_add:		[exported function]
414  *
415  *	Add a disk wedge based on the provided information.
416  *
417  *	The incoming dkw_devname[] is ignored, instead being
418  *	filled in and returned to the caller.
419  */
420 int
dkwedge_add(struct dkwedge_info * dkw)421 dkwedge_add(struct dkwedge_info *dkw)
422 {
423 	struct dkwedge_softc *sc, *lsc;
424 	struct disk *pdk;
425 	u_int unit;
426 	int error;
427 	dev_t pdev;
428 	device_t dev __diagused;
429 
430 	dkw->dkw_parent[sizeof(dkw->dkw_parent) - 1] = '\0';
431 	pdk = disk_find(dkw->dkw_parent);
432 	if (pdk == NULL)
433 		return ENXIO;
434 
435 	error = dkwedge_compute_pdev(pdk->dk_name, &pdev, VBLK);
436 	if (error)
437 		return error;
438 
439 	if (dkw->dkw_offset < 0)
440 		return EINVAL;
441 
442 	/*
443 	 * Check for an existing wedge at the same disk offset. Allow
444 	 * updating a wedge if the only change is the size, and the new
445 	 * size is larger than the old.
446 	 */
447 	sc = NULL;
448 	mutex_enter(&pdk->dk_openlock);
449 	LIST_FOREACH(lsc, &pdk->dk_wedges, sc_plink) {
450 		if (lsc->sc_offset != dkw->dkw_offset)
451 			continue;
452 		if (strcmp(lsc->sc_wname, dkw->dkw_wname) != 0)
453 			break;
454 		if (strcmp(lsc->sc_ptype, dkw->dkw_ptype) != 0)
455 			break;
456 		if (dkwedge_size(lsc) > dkw->dkw_size)
457 			break;
458 		if (lsc->sc_dev == NULL)
459 			break;
460 
461 		sc = lsc;
462 		device_acquire(sc->sc_dev);
463 		dkwedge_size_increase(sc, dkw->dkw_size);
464 		dk_set_geometry(sc, pdk);
465 
466 		break;
467 	}
468 	mutex_exit(&pdk->dk_openlock);
469 
470 	if (sc != NULL)
471 		goto announce;
472 
473 	sc = malloc(sizeof(*sc), M_DKWEDGE, M_WAITOK|M_ZERO);
474 	sc->sc_state = DKW_STATE_LARVAL;
475 	sc->sc_parent = pdk;
476 	sc->sc_pdev = pdev;
477 	sc->sc_offset = dkw->dkw_offset;
478 	dkwedge_size_init(sc, dkw->dkw_size);
479 
480 	memcpy(sc->sc_wname, dkw->dkw_wname, sizeof(sc->sc_wname));
481 	sc->sc_wname[sizeof(sc->sc_wname) - 1] = '\0';
482 
483 	memcpy(sc->sc_ptype, dkw->dkw_ptype, sizeof(sc->sc_ptype));
484 	sc->sc_ptype[sizeof(sc->sc_ptype) - 1] = '\0';
485 
486 	bufq_alloc(&sc->sc_bufq, "fcfs", 0);
487 
488 	callout_init(&sc->sc_restart_ch, 0);
489 	callout_setfunc(&sc->sc_restart_ch, dkrestart, sc);
490 
491 	mutex_init(&sc->sc_iolock, MUTEX_DEFAULT, IPL_BIO);
492 
493 	/*
494 	 * Wedge will be added; increment the wedge count for the parent.
495 	 * Only allow this to happen if RAW_PART is the only thing open.
496 	 */
497 	mutex_enter(&pdk->dk_openlock);
498 	if (pdk->dk_openmask & ~(1 << RAW_PART))
499 		error = EBUSY;
500 	else {
501 		/* Check for wedge overlap. */
502 		LIST_FOREACH(lsc, &pdk->dk_wedges, sc_plink) {
503 			/* XXX arithmetic overflow */
504 			uint64_t size = dkwedge_size(sc);
505 			uint64_t lsize = dkwedge_size(lsc);
506 			daddr_t lastblk = sc->sc_offset + size - 1;
507 			daddr_t llastblk = lsc->sc_offset + lsize - 1;
508 
509 			if (sc->sc_offset >= lsc->sc_offset &&
510 			    sc->sc_offset <= llastblk) {
511 				/* Overlaps the tail of the existing wedge. */
512 				break;
513 			}
514 			if (lastblk >= lsc->sc_offset &&
515 			    lastblk <= llastblk) {
516 				/* Overlaps the head of the existing wedge. */
517 			    	break;
518 			}
519 		}
520 		if (lsc != NULL) {
521 			if (sc->sc_offset == lsc->sc_offset &&
522 			    dkwedge_size(sc) == dkwedge_size(lsc) &&
523 			    strcmp(sc->sc_wname, lsc->sc_wname) == 0)
524 				error = EEXIST;
525 			else
526 				error = EINVAL;
527 		} else {
528 			pdk->dk_nwedges++;
529 			LIST_INSERT_HEAD(&pdk->dk_wedges, sc, sc_plink);
530 		}
531 	}
532 	mutex_exit(&pdk->dk_openlock);
533 	if (error) {
534 		mutex_destroy(&sc->sc_iolock);
535 		bufq_free(sc->sc_bufq);
536 		dkwedge_size_fini(sc);
537 		free(sc, M_DKWEDGE);
538 		return error;
539 	}
540 
541 	/* Fill in our cfdata for the pseudo-device glue. */
542 	sc->sc_cfdata.cf_name = dk_cd.cd_name;
543 	sc->sc_cfdata.cf_atname = dk_ca.ca_name;
544 	/* sc->sc_cfdata.cf_unit set below */
545 	sc->sc_cfdata.cf_fstate = FSTATE_NOTFOUND; /* use chosen cf_unit */
546 
547 	/* Insert the larval wedge into the array. */
548 	rw_enter(&dkwedges_lock, RW_WRITER);
549 	for (error = 0;;) {
550 		struct dkwedge_softc **scpp;
551 
552 		/*
553 		 * Check for a duplicate wname while searching for
554 		 * a slot.
555 		 */
556 		for (scpp = NULL, unit = 0; unit < ndkwedges; unit++) {
557 			if (dkwedges[unit] == NULL) {
558 				if (scpp == NULL) {
559 					scpp = &dkwedges[unit];
560 					sc->sc_cfdata.cf_unit = unit;
561 				}
562 			} else {
563 				/* XXX Unicode. */
564 				if (strcmp(dkwedges[unit]->sc_wname,
565 					sc->sc_wname) == 0) {
566 					error = EEXIST;
567 					break;
568 				}
569 			}
570 		}
571 		if (error)
572 			break;
573 		KASSERT(unit == ndkwedges);
574 		if (scpp == NULL) {
575 			error = dkwedge_array_expand();
576 			if (error)
577 				break;
578 		} else {
579 			KASSERT(scpp == &dkwedges[sc->sc_cfdata.cf_unit]);
580 			*scpp = sc;
581 			break;
582 		}
583 	}
584 	rw_exit(&dkwedges_lock);
585 	if (error) {
586 		mutex_enter(&pdk->dk_openlock);
587 		pdk->dk_nwedges--;
588 		LIST_REMOVE(sc, sc_plink);
589 		mutex_exit(&pdk->dk_openlock);
590 
591 		mutex_destroy(&sc->sc_iolock);
592 		bufq_free(sc->sc_bufq);
593 		dkwedge_size_fini(sc);
594 		free(sc, M_DKWEDGE);
595 		return error;
596 	}
597 
598 	/*
599 	 * Now that we know the unit #, attach a pseudo-device for
600 	 * this wedge instance.  This will provide us with the
601 	 * device_t necessary for glue to other parts of the system.
602 	 *
603 	 * This should never fail, unless we're almost totally out of
604 	 * memory.
605 	 */
606 	if ((dev = config_attach_pseudo_acquire(&sc->sc_cfdata, sc)) == NULL) {
607 		aprint_error("%s%u: unable to attach pseudo-device\n",
608 		    sc->sc_cfdata.cf_name, sc->sc_cfdata.cf_unit);
609 
610 		rw_enter(&dkwedges_lock, RW_WRITER);
611 		KASSERT(dkwedges[sc->sc_cfdata.cf_unit] == sc);
612 		dkwedges[sc->sc_cfdata.cf_unit] = NULL;
613 		rw_exit(&dkwedges_lock);
614 
615 		mutex_enter(&pdk->dk_openlock);
616 		pdk->dk_nwedges--;
617 		LIST_REMOVE(sc, sc_plink);
618 		mutex_exit(&pdk->dk_openlock);
619 
620 		mutex_destroy(&sc->sc_iolock);
621 		bufq_free(sc->sc_bufq);
622 		dkwedge_size_fini(sc);
623 		free(sc, M_DKWEDGE);
624 		return ENOMEM;
625 	}
626 
627 	KASSERT(dev == sc->sc_dev);
628 
629 announce:
630 	/* Announce our arrival. */
631 	aprint_normal(
632 	    "%s at %s: \"%s\", %"PRIu64" blocks at %"PRId64", type: %s\n",
633 	    device_xname(sc->sc_dev), pdk->dk_name,
634 	    sc->sc_wname,	/* XXX Unicode */
635 	    dkwedge_size(sc), sc->sc_offset,
636 	    sc->sc_ptype[0] == '\0' ? "<unknown>" : sc->sc_ptype);
637 
638 	/* Return the devname to the caller. */
639 	strlcpy(dkw->dkw_devname, device_xname(sc->sc_dev),
640 	    sizeof(dkw->dkw_devname));
641 
642 	device_release(sc->sc_dev);
643 	return 0;
644 }
645 
646 /*
647  * dkwedge_find_acquire:
648  *
649  *	Lookup a disk wedge based on the provided information.
650  *	NOTE: We look up the wedge based on the wedge devname,
651  *	not wname.
652  *
653  *	Return NULL if the wedge is not found, otherwise return
654  *	the wedge's softc.  Assign the wedge's unit number to unitp
655  *	if unitp is not NULL.  The wedge's sc_dev is referenced and
656  *	must be released by device_release or equivalent.
657  */
658 static struct dkwedge_softc *
dkwedge_find_acquire(struct dkwedge_info * dkw,u_int * unitp)659 dkwedge_find_acquire(struct dkwedge_info *dkw, u_int *unitp)
660 {
661 	struct dkwedge_softc *sc = NULL;
662 	u_int unit;
663 
664 	/* Find our softc. */
665 	dkw->dkw_devname[sizeof(dkw->dkw_devname) - 1] = '\0';
666 	rw_enter(&dkwedges_lock, RW_READER);
667 	for (unit = 0; unit < ndkwedges; unit++) {
668 		if ((sc = dkwedges[unit]) != NULL &&
669 		    sc->sc_dev != NULL &&
670 		    strcmp(device_xname(sc->sc_dev), dkw->dkw_devname) == 0 &&
671 		    strcmp(sc->sc_parent->dk_name, dkw->dkw_parent) == 0) {
672 			device_acquire(sc->sc_dev);
673 			break;
674 		}
675 	}
676 	rw_exit(&dkwedges_lock);
677 	if (sc == NULL)
678 		return NULL;
679 
680 	if (unitp != NULL)
681 		*unitp = unit;
682 
683 	return sc;
684 }
685 
686 /*
687  * dkwedge_del:		[exported function]
688  *
689  *	Delete a disk wedge based on the provided information.
690  *	NOTE: We look up the wedge based on the wedge devname,
691  *	not wname.
692  */
693 int
dkwedge_del(struct dkwedge_info * dkw)694 dkwedge_del(struct dkwedge_info *dkw)
695 {
696 
697 	return dkwedge_del1(dkw, 0);
698 }
699 
700 int
dkwedge_del1(struct dkwedge_info * dkw,int flags)701 dkwedge_del1(struct dkwedge_info *dkw, int flags)
702 {
703 	struct dkwedge_softc *sc = NULL;
704 
705 	/* Find our softc. */
706 	if ((sc = dkwedge_find_acquire(dkw, NULL)) == NULL)
707 		return ESRCH;
708 
709 	return config_detach_release(sc->sc_dev, flags);
710 }
711 
712 /*
713  * dkwedge_detach:
714  *
715  *	Autoconfiguration detach function for pseudo-device glue.
716  */
717 static int
dkwedge_detach(device_t self,int flags)718 dkwedge_detach(device_t self, int flags)
719 {
720 	struct dkwedge_softc *const sc = device_private(self);
721 	const u_int unit = device_unit(self);
722 	int bmaj, cmaj, error;
723 
724 	error = disk_begindetach(&sc->sc_dk, /*lastclose*/NULL, self, flags);
725 	if (error)
726 		return error;
727 
728 	/* Mark the wedge as dying. */
729 	sc->sc_state = DKW_STATE_DYING;
730 
731 	pmf_device_deregister(self);
732 
733 	/* Kill any pending restart. */
734 	mutex_enter(&sc->sc_iolock);
735 	sc->sc_iostop = true;
736 	mutex_exit(&sc->sc_iolock);
737 	callout_halt(&sc->sc_restart_ch, NULL);
738 
739 	/* Locate the wedge major numbers. */
740 	bmaj = bdevsw_lookup_major(&dk_bdevsw);
741 	cmaj = cdevsw_lookup_major(&dk_cdevsw);
742 
743 	/* Nuke the vnodes for any open instances. */
744 	vdevgone(bmaj, unit, unit, VBLK);
745 	vdevgone(cmaj, unit, unit, VCHR);
746 
747 	/*
748 	 * At this point, all block device opens have been closed,
749 	 * synchronously flushing any buffered writes; and all
750 	 * character device I/O operations have completed
751 	 * synchronously, and character device opens have been closed.
752 	 *
753 	 * So there can be no more opens or queued buffers by now.
754 	 */
755 	KASSERT(sc->sc_dk.dk_openmask == 0);
756 	KASSERT(bufq_peek(sc->sc_bufq) == NULL);
757 	bufq_drain(sc->sc_bufq);
758 
759 	/* Announce our departure. */
760 	aprint_normal("%s at %s (%s) deleted\n", device_xname(sc->sc_dev),
761 	    sc->sc_parent->dk_name,
762 	    sc->sc_wname);	/* XXX Unicode */
763 
764 	mutex_enter(&sc->sc_parent->dk_openlock);
765 	sc->sc_parent->dk_nwedges--;
766 	LIST_REMOVE(sc, sc_plink);
767 	mutex_exit(&sc->sc_parent->dk_openlock);
768 
769 	/* Delete our buffer queue. */
770 	bufq_free(sc->sc_bufq);
771 
772 	/* Detach from the disk list. */
773 	disk_detach(&sc->sc_dk);
774 	disk_destroy(&sc->sc_dk);
775 
776 	/* Poof. */
777 	rw_enter(&dkwedges_lock, RW_WRITER);
778 	KASSERT(dkwedges[unit] == sc);
779 	dkwedges[unit] = NULL;
780 	sc->sc_state = DKW_STATE_DEAD;
781 	rw_exit(&dkwedges_lock);
782 
783 	mutex_destroy(&sc->sc_iolock);
784 	dkwedge_size_fini(sc);
785 
786 	free(sc, M_DKWEDGE);
787 
788 	return 0;
789 }
790 
791 /*
792  * dkwedge_delall:	[exported function]
793  *
794  *	Forcibly delete all of the wedges on the specified disk.  Used
795  *	when a disk is being detached.
796  */
797 void
dkwedge_delall(struct disk * pdk)798 dkwedge_delall(struct disk *pdk)
799 {
800 
801 	dkwedge_delall1(pdk, /*idleonly*/false);
802 }
803 
804 /*
805  * dkwedge_delidle:	[exported function]
806  *
807  *	Delete all of the wedges on the specified disk if idle.  Used
808  *	by ioctl(DIOCRMWEDGES).
809  */
810 void
dkwedge_delidle(struct disk * pdk)811 dkwedge_delidle(struct disk *pdk)
812 {
813 
814 	dkwedge_delall1(pdk, /*idleonly*/true);
815 }
816 
817 static void
dkwedge_delall1(struct disk * pdk,bool idleonly)818 dkwedge_delall1(struct disk *pdk, bool idleonly)
819 {
820 	struct dkwedge_softc *sc;
821 	int flags;
822 
823 	flags = DETACH_QUIET;
824 	if (!idleonly)
825 		flags |= DETACH_FORCE;
826 
827 	for (;;) {
828 		mutex_enter(&pdk->dk_rawlock); /* for sc->sc_dk.dk_openmask */
829 		mutex_enter(&pdk->dk_openlock);
830 		LIST_FOREACH(sc, &pdk->dk_wedges, sc_plink) {
831 			/*
832 			 * Wedge is not yet created.  This is a race --
833 			 * it may as well have been added just after we
834 			 * deleted all the wedges, so pretend it's not
835 			 * here yet.
836 			 */
837 			if (sc->sc_dev == NULL)
838 				continue;
839 			if (!idleonly || sc->sc_dk.dk_openmask == 0) {
840 				device_acquire(sc->sc_dev);
841 				break;
842 			}
843 		}
844 		if (sc == NULL) {
845 			KASSERT(idleonly || pdk->dk_nwedges == 0);
846 			mutex_exit(&pdk->dk_openlock);
847 			mutex_exit(&pdk->dk_rawlock);
848 			return;
849 		}
850 		mutex_exit(&pdk->dk_openlock);
851 		mutex_exit(&pdk->dk_rawlock);
852 		(void)config_detach_release(sc->sc_dev, flags);
853 	}
854 }
855 
856 /*
857  * dkwedge_list:	[exported function]
858  *
859  *	List all of the wedges on a particular disk.
860  */
861 int
dkwedge_list(struct disk * pdk,struct dkwedge_list * dkwl,struct lwp * l)862 dkwedge_list(struct disk *pdk, struct dkwedge_list *dkwl, struct lwp *l)
863 {
864 	struct uio uio;
865 	struct iovec iov;
866 	struct dkwedge_softc *sc;
867 	struct dkwedge_info dkw;
868 	int error = 0;
869 
870 	iov.iov_base = dkwl->dkwl_buf;
871 	iov.iov_len = dkwl->dkwl_bufsize;
872 
873 	uio.uio_iov = &iov;
874 	uio.uio_iovcnt = 1;
875 	uio.uio_offset = 0;
876 	uio.uio_resid = dkwl->dkwl_bufsize;
877 	uio.uio_rw = UIO_READ;
878 	KASSERT(l == curlwp);
879 	uio.uio_vmspace = l->l_proc->p_vmspace;
880 
881 	dkwl->dkwl_ncopied = 0;
882 
883 	mutex_enter(&pdk->dk_openlock);
884 	LIST_FOREACH(sc, &pdk->dk_wedges, sc_plink) {
885 		if (uio.uio_resid < sizeof(dkw))
886 			break;
887 
888 		if (sc->sc_dev == NULL)
889 			continue;
890 
891 		strlcpy(dkw.dkw_devname, device_xname(sc->sc_dev),
892 		    sizeof(dkw.dkw_devname));
893 		memcpy(dkw.dkw_wname, sc->sc_wname, sizeof(dkw.dkw_wname));
894 		dkw.dkw_wname[sizeof(dkw.dkw_wname) - 1] = '\0';
895 		strlcpy(dkw.dkw_parent, sc->sc_parent->dk_name,
896 		    sizeof(dkw.dkw_parent));
897 		dkw.dkw_offset = sc->sc_offset;
898 		dkw.dkw_size = dkwedge_size(sc);
899 		strlcpy(dkw.dkw_ptype, sc->sc_ptype, sizeof(dkw.dkw_ptype));
900 
901 		/*
902 		 * Acquire a device reference so this wedge doesn't go
903 		 * away before our next iteration in LIST_FOREACH, and
904 		 * then release the lock for uiomove.
905 		 */
906 		device_acquire(sc->sc_dev);
907 		mutex_exit(&pdk->dk_openlock);
908 		error = uiomove(&dkw, sizeof(dkw), &uio);
909 		mutex_enter(&pdk->dk_openlock);
910 		device_release(sc->sc_dev);
911 		if (error)
912 			break;
913 
914 		dkwl->dkwl_ncopied++;
915 	}
916 	dkwl->dkwl_nwedges = pdk->dk_nwedges;
917 	mutex_exit(&pdk->dk_openlock);
918 
919 	return error;
920 }
921 
922 static device_t
dkwedge_find_by_wname_acquire(const char * wname)923 dkwedge_find_by_wname_acquire(const char *wname)
924 {
925 	device_t dv = NULL;
926 	struct dkwedge_softc *sc;
927 	int i;
928 
929 	rw_enter(&dkwedges_lock, RW_READER);
930 	for (i = 0; i < ndkwedges; i++) {
931 		if ((sc = dkwedges[i]) == NULL || sc->sc_dev == NULL)
932 			continue;
933 		if (strcmp(sc->sc_wname, wname) == 0) {
934 			if (dv != NULL) {
935 				printf(
936 				    "WARNING: double match for wedge name %s "
937 				    "(%s, %s)\n", wname, device_xname(dv),
938 				    device_xname(sc->sc_dev));
939 				continue;
940 			}
941 			device_acquire(sc->sc_dev);
942 			dv = sc->sc_dev;
943 		}
944 	}
945 	rw_exit(&dkwedges_lock);
946 	return dv;
947 }
948 
949 static device_t
dkwedge_find_by_parent_acquire(const char * name,size_t * i)950 dkwedge_find_by_parent_acquire(const char *name, size_t *i)
951 {
952 
953 	rw_enter(&dkwedges_lock, RW_READER);
954 	for (; *i < (size_t)ndkwedges; (*i)++) {
955 		struct dkwedge_softc *sc;
956 		if ((sc = dkwedges[*i]) == NULL || sc->sc_dev == NULL)
957 			continue;
958 		if (strcmp(sc->sc_parent->dk_name, name) != 0)
959 			continue;
960 		device_acquire(sc->sc_dev);
961 		rw_exit(&dkwedges_lock);
962 		return sc->sc_dev;
963 	}
964 	rw_exit(&dkwedges_lock);
965 	return NULL;
966 }
967 
968 /* XXX unsafe */
969 device_t
dkwedge_find_by_wname(const char * wname)970 dkwedge_find_by_wname(const char *wname)
971 {
972 	device_t dv;
973 
974 	if ((dv = dkwedge_find_by_wname_acquire(wname)) == NULL)
975 		return NULL;
976 	device_release(dv);
977 	return dv;
978 }
979 
980 /* XXX unsafe */
981 device_t
dkwedge_find_by_parent(const char * name,size_t * i)982 dkwedge_find_by_parent(const char *name, size_t *i)
983 {
984 	device_t dv;
985 
986 	if ((dv = dkwedge_find_by_parent_acquire(name, i)) == NULL)
987 		return NULL;
988 	device_release(dv);
989 	return dv;
990 }
991 
992 void
dkwedge_print_wnames(void)993 dkwedge_print_wnames(void)
994 {
995 	struct dkwedge_softc *sc;
996 	int i;
997 
998 	rw_enter(&dkwedges_lock, RW_READER);
999 	for (i = 0; i < ndkwedges; i++) {
1000 		if ((sc = dkwedges[i]) == NULL || sc->sc_dev == NULL)
1001 			continue;
1002 		printf(" wedge:%s", sc->sc_wname);
1003 	}
1004 	rw_exit(&dkwedges_lock);
1005 }
1006 
1007 /*
1008  * We need a dummy object to stuff into the dkwedge discovery method link
1009  * set to ensure that there is always at least one object in the set.
1010  */
1011 static struct dkwedge_discovery_method dummy_discovery_method;
1012 __link_set_add_bss(dkwedge_methods, dummy_discovery_method);
1013 
1014 /*
1015  * dkwedge_init:
1016  *
1017  *	Initialize the disk wedge subsystem.
1018  */
1019 void
dkwedge_init(void)1020 dkwedge_init(void)
1021 {
1022 	__link_set_decl(dkwedge_methods, struct dkwedge_discovery_method);
1023 	struct dkwedge_discovery_method * const *ddmp;
1024 	struct dkwedge_discovery_method *lddm, *ddm;
1025 
1026 	rw_init(&dkwedges_lock);
1027 	rw_init(&dkwedge_discovery_methods_lock);
1028 
1029 	if (config_cfdriver_attach(&dk_cd) != 0)
1030 		panic("dkwedge: unable to attach cfdriver");
1031 	if (config_cfattach_attach(dk_cd.cd_name, &dk_ca) != 0)
1032 		panic("dkwedge: unable to attach cfattach");
1033 
1034 	rw_enter(&dkwedge_discovery_methods_lock, RW_WRITER);
1035 
1036 	LIST_INIT(&dkwedge_discovery_methods);
1037 
1038 	__link_set_foreach(ddmp, dkwedge_methods) {
1039 		ddm = *ddmp;
1040 		if (ddm == &dummy_discovery_method)
1041 			continue;
1042 		if (LIST_EMPTY(&dkwedge_discovery_methods)) {
1043 			LIST_INSERT_HEAD(&dkwedge_discovery_methods,
1044 			    ddm, ddm_list);
1045 			continue;
1046 		}
1047 		LIST_FOREACH(lddm, &dkwedge_discovery_methods, ddm_list) {
1048 			if (ddm->ddm_priority == lddm->ddm_priority) {
1049 				aprint_error("dk-method-%s: method \"%s\" "
1050 				    "already exists at priority %d\n",
1051 				    ddm->ddm_name, lddm->ddm_name,
1052 				    lddm->ddm_priority);
1053 				/* Not inserted. */
1054 				break;
1055 			}
1056 			if (ddm->ddm_priority < lddm->ddm_priority) {
1057 				/* Higher priority; insert before. */
1058 				LIST_INSERT_BEFORE(lddm, ddm, ddm_list);
1059 				break;
1060 			}
1061 			if (LIST_NEXT(lddm, ddm_list) == NULL) {
1062 				/* Last one; insert after. */
1063 				KASSERT(lddm->ddm_priority < ddm->ddm_priority);
1064 				LIST_INSERT_AFTER(lddm, ddm, ddm_list);
1065 				break;
1066 			}
1067 		}
1068 	}
1069 
1070 	rw_exit(&dkwedge_discovery_methods_lock);
1071 }
1072 
1073 #ifdef DKWEDGE_AUTODISCOVER
1074 int	dkwedge_autodiscover = 1;
1075 #else
1076 int	dkwedge_autodiscover = 0;
1077 #endif
1078 
1079 /*
1080  * dkwedge_discover:	[exported function]
1081  *
1082  *	Discover the wedges on a newly attached disk.
1083  *	Remove all unused wedges on the disk first.
1084  */
1085 void
dkwedge_discover(struct disk * pdk)1086 dkwedge_discover(struct disk *pdk)
1087 {
1088 	struct dkwedge_discovery_method *ddm;
1089 	struct vnode *vp;
1090 	int error;
1091 	dev_t pdev;
1092 
1093 	/*
1094 	 * Require people playing with wedges to enable this explicitly.
1095 	 */
1096 	if (dkwedge_autodiscover == 0)
1097 		return;
1098 
1099 	rw_enter(&dkwedge_discovery_methods_lock, RW_READER);
1100 
1101 	/*
1102 	 * Use the character device for scanning, the block device
1103 	 * is busy if there are already wedges attached.
1104 	 */
1105 	error = dkwedge_compute_pdev(pdk->dk_name, &pdev, VCHR);
1106 	if (error) {
1107 		aprint_error("%s: unable to compute pdev, error = %d\n",
1108 		    pdk->dk_name, error);
1109 		goto out;
1110 	}
1111 
1112 	error = cdevvp(pdev, &vp);
1113 	if (error) {
1114 		aprint_error("%s: unable to find vnode for pdev, error = %d\n",
1115 		    pdk->dk_name, error);
1116 		goto out;
1117 	}
1118 
1119 	error = vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
1120 	if (error) {
1121 		aprint_error("%s: unable to lock vnode for pdev, error = %d\n",
1122 		    pdk->dk_name, error);
1123 		vrele(vp);
1124 		goto out;
1125 	}
1126 
1127 	error = VOP_OPEN(vp, FREAD | FSILENT, NOCRED);
1128 	if (error) {
1129 		if (error != ENXIO)
1130 			aprint_error("%s: unable to open device, error = %d\n",
1131 			    pdk->dk_name, error);
1132 		vput(vp);
1133 		goto out;
1134 	}
1135 	VOP_UNLOCK(vp);
1136 
1137 	/*
1138 	 * Remove unused wedges
1139 	 */
1140 	dkwedge_delidle(pdk);
1141 
1142 	/*
1143 	 * For each supported partition map type, look to see if
1144 	 * this map type exists.  If so, parse it and add the
1145 	 * corresponding wedges.
1146 	 */
1147 	LIST_FOREACH(ddm, &dkwedge_discovery_methods, ddm_list) {
1148 		error = (*ddm->ddm_discover)(pdk, vp);
1149 		if (error == 0) {
1150 			/* Successfully created wedges; we're done. */
1151 			break;
1152 		}
1153 	}
1154 
1155 	error = vn_close(vp, FREAD, NOCRED);
1156 	if (error) {
1157 		aprint_error("%s: unable to close device, error = %d\n",
1158 		    pdk->dk_name, error);
1159 		/* We'll just assume the vnode has been cleaned up. */
1160 	}
1161 
1162 out:
1163 	rw_exit(&dkwedge_discovery_methods_lock);
1164 }
1165 
1166 /*
1167  * dkwedge_read:
1168  *
1169  *	Read some data from the specified disk, used for
1170  *	partition discovery.
1171  */
1172 int
dkwedge_read(struct disk * pdk,struct vnode * vp,daddr_t blkno,void * tbuf,size_t len)1173 dkwedge_read(struct disk *pdk, struct vnode *vp, daddr_t blkno,
1174     void *tbuf, size_t len)
1175 {
1176 	buf_t *bp;
1177 	int error;
1178 	bool isopen;
1179 	dev_t bdev;
1180 	struct vnode *bdvp;
1181 
1182 	/*
1183 	 * The kernel cannot read from a character device vnode
1184 	 * as physio() only handles user memory.
1185 	 *
1186 	 * If the block device has already been opened by a wedge
1187 	 * use that vnode and temporarily bump the open counter.
1188 	 *
1189 	 * Otherwise try to open the block device.
1190 	 */
1191 
1192 	bdev = devsw_chr2blk(vp->v_rdev);
1193 
1194 	mutex_enter(&pdk->dk_rawlock);
1195 	if (pdk->dk_rawopens != 0) {
1196 		KASSERT(pdk->dk_rawvp != NULL);
1197 		isopen = true;
1198 		++pdk->dk_rawopens;
1199 		bdvp = pdk->dk_rawvp;
1200 		error = 0;
1201 	} else {
1202 		isopen = false;
1203 		error = dk_open_parent(bdev, FREAD, &bdvp);
1204 	}
1205 	mutex_exit(&pdk->dk_rawlock);
1206 
1207 	if (error)
1208 		return error;
1209 
1210 	bp = getiobuf(bdvp, true);
1211 	bp->b_flags = B_READ;
1212 	bp->b_cflags = BC_BUSY;
1213 	bp->b_dev = bdev;
1214 	bp->b_data = tbuf;
1215 	bp->b_bufsize = bp->b_bcount = len;
1216 	bp->b_blkno = blkno;
1217 	bp->b_cylinder = 0;
1218 	bp->b_error = 0;
1219 
1220 	VOP_STRATEGY(bdvp, bp);
1221 	error = biowait(bp);
1222 	putiobuf(bp);
1223 
1224 	mutex_enter(&pdk->dk_rawlock);
1225 	if (isopen) {
1226 		--pdk->dk_rawopens;
1227 	} else {
1228 		dk_close_parent(bdvp, FREAD);
1229 	}
1230 	mutex_exit(&pdk->dk_rawlock);
1231 
1232 	return error;
1233 }
1234 
1235 /*
1236  * dkwedge_lookup:
1237  *
1238  *	Look up a dkwedge_softc based on the provided dev_t.
1239  *
1240  *	Caller must guarantee the wedge is referenced.
1241  */
1242 static struct dkwedge_softc *
dkwedge_lookup(dev_t dev)1243 dkwedge_lookup(dev_t dev)
1244 {
1245 
1246 	return device_lookup_private(&dk_cd, minor(dev));
1247 }
1248 
1249 static struct dkwedge_softc *
dkwedge_lookup_acquire(dev_t dev)1250 dkwedge_lookup_acquire(dev_t dev)
1251 {
1252 	device_t dv = device_lookup_acquire(&dk_cd, minor(dev));
1253 
1254 	if (dv == NULL)
1255 		return NULL;
1256 	return device_private(dv);
1257 }
1258 
1259 static int
dk_open_parent(dev_t dev,int mode,struct vnode ** vpp)1260 dk_open_parent(dev_t dev, int mode, struct vnode **vpp)
1261 {
1262 	struct vnode *vp;
1263 	int error;
1264 
1265 	error = bdevvp(dev, &vp);
1266 	if (error)
1267 		return error;
1268 
1269 	error = vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
1270 	if (error) {
1271 		vrele(vp);
1272 		return error;
1273 	}
1274 	error = VOP_OPEN(vp, mode, NOCRED);
1275 	if (error) {
1276 		vput(vp);
1277 		return error;
1278 	}
1279 
1280 	/* VOP_OPEN() doesn't do this for us. */
1281 	if (mode & FWRITE) {
1282 		mutex_enter(vp->v_interlock);
1283 		vp->v_writecount++;
1284 		mutex_exit(vp->v_interlock);
1285 	}
1286 
1287 	VOP_UNLOCK(vp);
1288 
1289 	*vpp = vp;
1290 
1291 	return 0;
1292 }
1293 
1294 static int
dk_close_parent(struct vnode * vp,int mode)1295 dk_close_parent(struct vnode *vp, int mode)
1296 {
1297 	int error;
1298 
1299 	error = vn_close(vp, mode, NOCRED);
1300 	return error;
1301 }
1302 
1303 /*
1304  * dkopen:		[devsw entry point]
1305  *
1306  *	Open a wedge.
1307  */
1308 static int
dkopen(dev_t dev,int flags,int fmt,struct lwp * l)1309 dkopen(dev_t dev, int flags, int fmt, struct lwp *l)
1310 {
1311 	struct dkwedge_softc *sc = dkwedge_lookup(dev);
1312 	int error = 0;
1313 
1314 	if (sc == NULL)
1315 		return ENXIO;
1316 	KASSERT(sc->sc_dev != NULL);
1317 	KASSERT(sc->sc_state == DKW_STATE_RUNNING);
1318 
1319 	/*
1320 	 * We go through a complicated little dance to only open the parent
1321 	 * vnode once per wedge, no matter how many times the wedge is
1322 	 * opened.  The reason?  We see one dkopen() per open call, but
1323 	 * only dkclose() on the last close.
1324 	 */
1325 	mutex_enter(&sc->sc_dk.dk_openlock);
1326 	mutex_enter(&sc->sc_parent->dk_rawlock);
1327 	if (sc->sc_dk.dk_openmask == 0) {
1328 		error = dkfirstopen(sc, flags);
1329 		if (error)
1330 			goto out;
1331 	} else if (flags & ~sc->sc_mode & FWRITE) {
1332 		/*
1333 		 * The parent is already open, but the previous attempt
1334 		 * to open it read/write failed and fell back to
1335 		 * read-only.  In that case, we assume the medium is
1336 		 * read-only and fail to open the wedge read/write.
1337 		 */
1338 		error = EROFS;
1339 		goto out;
1340 	}
1341 	KASSERT(sc->sc_mode != 0);
1342 	KASSERTMSG(sc->sc_mode & FREAD, "%s: sc_mode=%x",
1343 	    device_xname(sc->sc_dev), sc->sc_mode);
1344 	KASSERTMSG((flags & FWRITE) ? (sc->sc_mode & FWRITE) : 1,
1345 	    "%s: flags=%x sc_mode=%x",
1346 	    device_xname(sc->sc_dev), flags, sc->sc_mode);
1347 	if (fmt == S_IFCHR)
1348 		sc->sc_dk.dk_copenmask |= 1;
1349 	else
1350 		sc->sc_dk.dk_bopenmask |= 1;
1351 	sc->sc_dk.dk_openmask =
1352 	    sc->sc_dk.dk_copenmask | sc->sc_dk.dk_bopenmask;
1353 
1354 out:	mutex_exit(&sc->sc_parent->dk_rawlock);
1355 	mutex_exit(&sc->sc_dk.dk_openlock);
1356 	return error;
1357 }
1358 
1359 static int
dkfirstopen(struct dkwedge_softc * sc,int flags)1360 dkfirstopen(struct dkwedge_softc *sc, int flags)
1361 {
1362 	struct dkwedge_softc *nsc;
1363 	struct vnode *vp;
1364 	int mode;
1365 	int error;
1366 
1367 	KASSERT(mutex_owned(&sc->sc_dk.dk_openlock));
1368 	KASSERT(mutex_owned(&sc->sc_parent->dk_rawlock));
1369 
1370 	if (sc->sc_parent->dk_rawopens == 0) {
1371 		KASSERT(sc->sc_parent->dk_rawvp == NULL);
1372 		/*
1373 		 * Try open read-write. If this fails for EROFS
1374 		 * and wedge is read-only, retry to open read-only.
1375 		 */
1376 		mode = FREAD | FWRITE;
1377 		error = dk_open_parent(sc->sc_pdev, mode, &vp);
1378 		if (error == EROFS && (flags & FWRITE) == 0) {
1379 			mode &= ~FWRITE;
1380 			error = dk_open_parent(sc->sc_pdev, mode, &vp);
1381 		}
1382 		if (error)
1383 			return error;
1384 		KASSERT(vp != NULL);
1385 		sc->sc_parent->dk_rawvp = vp;
1386 	} else {
1387 		/*
1388 		 * Retrieve mode from an already opened wedge.
1389 		 *
1390 		 * At this point, dk_rawopens is bounded by the number
1391 		 * of dkwedge devices in the system, which is limited
1392 		 * by autoconf device numbering to INT_MAX.  Since
1393 		 * dk_rawopens is unsigned, this can't overflow.
1394 		 */
1395 		KASSERT(sc->sc_parent->dk_rawopens < UINT_MAX);
1396 		KASSERT(sc->sc_parent->dk_rawvp != NULL);
1397 		mode = 0;
1398 		mutex_enter(&sc->sc_parent->dk_openlock);
1399 		LIST_FOREACH(nsc, &sc->sc_parent->dk_wedges, sc_plink) {
1400 			if (nsc == sc || nsc->sc_dk.dk_openmask == 0)
1401 				continue;
1402 			mode = nsc->sc_mode;
1403 			break;
1404 		}
1405 		mutex_exit(&sc->sc_parent->dk_openlock);
1406 	}
1407 	sc->sc_mode = mode;
1408 	sc->sc_parent->dk_rawopens++;
1409 
1410 	return 0;
1411 }
1412 
1413 static void
dklastclose(struct dkwedge_softc * sc)1414 dklastclose(struct dkwedge_softc *sc)
1415 {
1416 
1417 	KASSERT(mutex_owned(&sc->sc_dk.dk_openlock));
1418 	KASSERT(mutex_owned(&sc->sc_parent->dk_rawlock));
1419 	KASSERT(sc->sc_parent->dk_rawopens > 0);
1420 	KASSERT(sc->sc_parent->dk_rawvp != NULL);
1421 
1422 	if (--sc->sc_parent->dk_rawopens == 0) {
1423 		struct vnode *const vp = sc->sc_parent->dk_rawvp;
1424 		const int mode = sc->sc_mode;
1425 
1426 		sc->sc_parent->dk_rawvp = NULL;
1427 		sc->sc_mode = 0;
1428 
1429 		dk_close_parent(vp, mode);
1430 	}
1431 }
1432 
1433 /*
1434  * dkclose:		[devsw entry point]
1435  *
1436  *	Close a wedge.
1437  */
1438 static int
dkclose(dev_t dev,int flags,int fmt,struct lwp * l)1439 dkclose(dev_t dev, int flags, int fmt, struct lwp *l)
1440 {
1441 	struct dkwedge_softc *sc = dkwedge_lookup(dev);
1442 
1443 	/*
1444 	 * dkclose can be called even if dkopen didn't succeed, so we
1445 	 * have to handle the same possibility that the wedge may not
1446 	 * exist.
1447 	 */
1448 	if (sc == NULL)
1449 		return ENXIO;
1450 	KASSERT(sc->sc_dev != NULL);
1451 	KASSERT(sc->sc_state != DKW_STATE_LARVAL);
1452 	KASSERT(sc->sc_state != DKW_STATE_DEAD);
1453 
1454 	mutex_enter(&sc->sc_dk.dk_openlock);
1455 	mutex_enter(&sc->sc_parent->dk_rawlock);
1456 
1457 	KASSERT(sc->sc_dk.dk_openmask != 0);
1458 
1459 	if (fmt == S_IFCHR)
1460 		sc->sc_dk.dk_copenmask &= ~1;
1461 	else
1462 		sc->sc_dk.dk_bopenmask &= ~1;
1463 	sc->sc_dk.dk_openmask =
1464 	    sc->sc_dk.dk_copenmask | sc->sc_dk.dk_bopenmask;
1465 
1466 	if (sc->sc_dk.dk_openmask == 0) {
1467 		dklastclose(sc);
1468 	}
1469 
1470 	mutex_exit(&sc->sc_parent->dk_rawlock);
1471 	mutex_exit(&sc->sc_dk.dk_openlock);
1472 
1473 	return 0;
1474 }
1475 
1476 /*
1477  * dkcancel:		[devsw entry point]
1478  *
1479  *	Cancel any pending I/O operations waiting on a wedge.
1480  */
1481 static int
dkcancel(dev_t dev,int flags,int fmt,struct lwp * l)1482 dkcancel(dev_t dev, int flags, int fmt, struct lwp *l)
1483 {
1484 	struct dkwedge_softc *sc = dkwedge_lookup(dev);
1485 
1486 	KASSERT(sc != NULL);
1487 	KASSERT(sc->sc_dev != NULL);
1488 	KASSERT(sc->sc_state != DKW_STATE_LARVAL);
1489 	KASSERT(sc->sc_state != DKW_STATE_DEAD);
1490 
1491 	/*
1492 	 * Disk I/O is expected to complete or fail within a reasonable
1493 	 * timeframe -- it's storage, not communication.  Further, the
1494 	 * character and block device interface guarantees that prior
1495 	 * reads and writes have completed or failed by the time close
1496 	 * returns -- we are not to cancel them here.  If the parent
1497 	 * device's hardware is gone, the parent driver can make them
1498 	 * fail.  Nothing for dk(4) itself to do.
1499 	 */
1500 
1501 	return 0;
1502 }
1503 
1504 /*
1505  * dkstrategy:		[devsw entry point]
1506  *
1507  *	Perform I/O based on the wedge I/O strategy.
1508  */
1509 static void
dkstrategy(struct buf * bp)1510 dkstrategy(struct buf *bp)
1511 {
1512 	struct dkwedge_softc *sc = dkwedge_lookup(bp->b_dev);
1513 	uint64_t p_size, p_offset;
1514 
1515 	KASSERT(sc != NULL);
1516 	KASSERT(sc->sc_dev != NULL);
1517 	KASSERT(sc->sc_state != DKW_STATE_LARVAL);
1518 	KASSERT(sc->sc_state != DKW_STATE_DEAD);
1519 	KASSERT(sc->sc_parent->dk_rawvp != NULL);
1520 
1521 	/* If it's an empty transfer, wake up the top half now. */
1522 	if (bp->b_bcount == 0)
1523 		goto done;
1524 
1525 	p_offset = sc->sc_offset << sc->sc_parent->dk_blkshift;
1526 	p_size = dkwedge_size(sc) << sc->sc_parent->dk_blkshift;
1527 
1528 	/* Make sure it's in-range. */
1529 	if (bounds_check_with_mediasize(bp, DEV_BSIZE, p_size) <= 0)
1530 		goto done;
1531 
1532 	/* Translate it to the parent's raw LBA. */
1533 	bp->b_rawblkno = bp->b_blkno + p_offset;
1534 
1535 	/* Place it in the queue and start I/O on the unit. */
1536 	mutex_enter(&sc->sc_iolock);
1537 	disk_wait(&sc->sc_dk);
1538 	bufq_put(sc->sc_bufq, bp);
1539 	mutex_exit(&sc->sc_iolock);
1540 
1541 	dkstart(sc);
1542 	return;
1543 
1544 done:
1545 	bp->b_resid = bp->b_bcount;
1546 	biodone(bp);
1547 }
1548 
1549 /*
1550  * dkstart:
1551  *
1552  *	Start I/O that has been enqueued on the wedge.
1553  */
1554 static void
dkstart(struct dkwedge_softc * sc)1555 dkstart(struct dkwedge_softc *sc)
1556 {
1557 	struct vnode *vp;
1558 	struct buf *bp, *nbp;
1559 
1560 	mutex_enter(&sc->sc_iolock);
1561 
1562 	/* Do as much work as has been enqueued. */
1563 	while ((bp = bufq_peek(sc->sc_bufq)) != NULL) {
1564 		if (sc->sc_iostop) {
1565 			(void) bufq_get(sc->sc_bufq);
1566 			mutex_exit(&sc->sc_iolock);
1567 			bp->b_error = ENXIO;
1568 			bp->b_resid = bp->b_bcount;
1569 			biodone(bp);
1570 			mutex_enter(&sc->sc_iolock);
1571 			continue;
1572 		}
1573 
1574 		/* fetch an I/O buf with sc_iolock dropped */
1575 		mutex_exit(&sc->sc_iolock);
1576 		nbp = getiobuf(sc->sc_parent->dk_rawvp, false);
1577 		mutex_enter(&sc->sc_iolock);
1578 		if (nbp == NULL) {
1579 			/*
1580 			 * No resources to run this request; leave the
1581 			 * buffer queued up, and schedule a timer to
1582 			 * restart the queue in 1/2 a second.
1583 			 */
1584 			if (!sc->sc_iostop)
1585 				callout_schedule(&sc->sc_restart_ch, hz/2);
1586 			break;
1587 		}
1588 
1589 		/*
1590 		 * fetch buf, this can fail if another thread
1591 		 * has already processed the queue, it can also
1592 		 * return a completely different buf.
1593 		 */
1594 		bp = bufq_get(sc->sc_bufq);
1595 		if (bp == NULL) {
1596 			mutex_exit(&sc->sc_iolock);
1597 			putiobuf(nbp);
1598 			mutex_enter(&sc->sc_iolock);
1599 			continue;
1600 		}
1601 
1602 		/* Instrumentation. */
1603 		disk_busy(&sc->sc_dk);
1604 
1605 		/* release lock for VOP_STRATEGY */
1606 		mutex_exit(&sc->sc_iolock);
1607 
1608 		nbp->b_data = bp->b_data;
1609 		nbp->b_flags = bp->b_flags;
1610 		nbp->b_oflags = bp->b_oflags;
1611 		nbp->b_cflags = bp->b_cflags;
1612 		nbp->b_iodone = dkiodone;
1613 		nbp->b_proc = bp->b_proc;
1614 		nbp->b_blkno = bp->b_rawblkno;
1615 		nbp->b_dev = sc->sc_parent->dk_rawvp->v_rdev;
1616 		nbp->b_bcount = bp->b_bcount;
1617 		nbp->b_private = bp;
1618 		BIO_COPYPRIO(nbp, bp);
1619 
1620 		vp = nbp->b_vp;
1621 		if ((nbp->b_flags & B_READ) == 0) {
1622 			mutex_enter(vp->v_interlock);
1623 			vp->v_numoutput++;
1624 			mutex_exit(vp->v_interlock);
1625 		}
1626 		VOP_STRATEGY(vp, nbp);
1627 
1628 		mutex_enter(&sc->sc_iolock);
1629 	}
1630 
1631 	mutex_exit(&sc->sc_iolock);
1632 }
1633 
1634 /*
1635  * dkiodone:
1636  *
1637  *	I/O to a wedge has completed; alert the top half.
1638  */
1639 static void
dkiodone(struct buf * bp)1640 dkiodone(struct buf *bp)
1641 {
1642 	struct buf *obp = bp->b_private;
1643 	struct dkwedge_softc *sc = dkwedge_lookup(obp->b_dev);
1644 
1645 	KASSERT(sc != NULL);
1646 	KASSERT(sc->sc_dev != NULL);
1647 
1648 	if (bp->b_error != 0)
1649 		obp->b_error = bp->b_error;
1650 	obp->b_resid = bp->b_resid;
1651 	putiobuf(bp);
1652 
1653 	mutex_enter(&sc->sc_iolock);
1654 	disk_unbusy(&sc->sc_dk, obp->b_bcount - obp->b_resid,
1655 	    obp->b_flags & B_READ);
1656 	mutex_exit(&sc->sc_iolock);
1657 
1658 	biodone(obp);
1659 
1660 	/* Kick the queue in case there is more work we can do. */
1661 	dkstart(sc);
1662 }
1663 
1664 /*
1665  * dkrestart:
1666  *
1667  *	Restart the work queue after it was stalled due to
1668  *	a resource shortage.  Invoked via a callout.
1669  */
1670 static void
dkrestart(void * v)1671 dkrestart(void *v)
1672 {
1673 	struct dkwedge_softc *sc = v;
1674 
1675 	dkstart(sc);
1676 }
1677 
1678 /*
1679  * dkminphys:
1680  *
1681  *	Call parent's minphys function.
1682  */
1683 static void
dkminphys(struct buf * bp)1684 dkminphys(struct buf *bp)
1685 {
1686 	struct dkwedge_softc *sc = dkwedge_lookup(bp->b_dev);
1687 	dev_t dev;
1688 
1689 	KASSERT(sc != NULL);
1690 	KASSERT(sc->sc_dev != NULL);
1691 
1692 	dev = bp->b_dev;
1693 	bp->b_dev = sc->sc_pdev;
1694 	if (sc->sc_parent->dk_driver && sc->sc_parent->dk_driver->d_minphys)
1695 		(*sc->sc_parent->dk_driver->d_minphys)(bp);
1696 	else
1697 		minphys(bp);
1698 	bp->b_dev = dev;
1699 }
1700 
1701 /*
1702  * dkread:		[devsw entry point]
1703  *
1704  *	Read from a wedge.
1705  */
1706 static int
dkread(dev_t dev,struct uio * uio,int flags)1707 dkread(dev_t dev, struct uio *uio, int flags)
1708 {
1709 	struct dkwedge_softc *sc __diagused = dkwedge_lookup(dev);
1710 
1711 	KASSERT(sc != NULL);
1712 	KASSERT(sc->sc_dev != NULL);
1713 	KASSERT(sc->sc_state != DKW_STATE_LARVAL);
1714 	KASSERT(sc->sc_state != DKW_STATE_DEAD);
1715 
1716 	return physio(dkstrategy, NULL, dev, B_READ, dkminphys, uio);
1717 }
1718 
1719 /*
1720  * dkwrite:		[devsw entry point]
1721  *
1722  *	Write to a wedge.
1723  */
1724 static int
dkwrite(dev_t dev,struct uio * uio,int flags)1725 dkwrite(dev_t dev, struct uio *uio, int flags)
1726 {
1727 	struct dkwedge_softc *sc __diagused = dkwedge_lookup(dev);
1728 
1729 	KASSERT(sc != NULL);
1730 	KASSERT(sc->sc_dev != NULL);
1731 	KASSERT(sc->sc_state != DKW_STATE_LARVAL);
1732 	KASSERT(sc->sc_state != DKW_STATE_DEAD);
1733 
1734 	return physio(dkstrategy, NULL, dev, B_WRITE, dkminphys, uio);
1735 }
1736 
1737 /*
1738  * dkioctl:		[devsw entry point]
1739  *
1740  *	Perform an ioctl request on a wedge.
1741  */
1742 static int
dkioctl(dev_t dev,u_long cmd,void * data,int flag,struct lwp * l)1743 dkioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
1744 {
1745 	struct dkwedge_softc *sc = dkwedge_lookup(dev);
1746 	int error = 0;
1747 
1748 	KASSERT(sc != NULL);
1749 	KASSERT(sc->sc_dev != NULL);
1750 	KASSERT(sc->sc_state != DKW_STATE_LARVAL);
1751 	KASSERT(sc->sc_state != DKW_STATE_DEAD);
1752 	KASSERT(sc->sc_parent->dk_rawvp != NULL);
1753 
1754 	/*
1755 	 * We pass NODEV instead of our device to indicate we don't
1756 	 * want to handle disklabel ioctls
1757 	 */
1758 	error = disk_ioctl(&sc->sc_dk, NODEV, cmd, data, flag, l);
1759 	if (error != EPASSTHROUGH)
1760 		return error;
1761 
1762 	error = 0;
1763 
1764 	switch (cmd) {
1765 	case DIOCGSTRATEGY:
1766 	case DIOCGCACHE:
1767 	case DIOCCACHESYNC:
1768 		error = VOP_IOCTL(sc->sc_parent->dk_rawvp, cmd, data, flag,
1769 		    l != NULL ? l->l_cred : NOCRED);
1770 		break;
1771 	case DIOCGWEDGEINFO: {
1772 		struct dkwedge_info *dkw = data;
1773 
1774 		strlcpy(dkw->dkw_devname, device_xname(sc->sc_dev),
1775 		    sizeof(dkw->dkw_devname));
1776 	    	memcpy(dkw->dkw_wname, sc->sc_wname, sizeof(dkw->dkw_wname));
1777 		dkw->dkw_wname[sizeof(dkw->dkw_wname) - 1] = '\0';
1778 		strlcpy(dkw->dkw_parent, sc->sc_parent->dk_name,
1779 		    sizeof(dkw->dkw_parent));
1780 		dkw->dkw_offset = sc->sc_offset;
1781 		dkw->dkw_size = dkwedge_size(sc);
1782 		strlcpy(dkw->dkw_ptype, sc->sc_ptype, sizeof(dkw->dkw_ptype));
1783 
1784 		break;
1785 	}
1786 	case DIOCGSECTORALIGN: {
1787 		struct disk_sectoralign *dsa = data;
1788 		uint32_t r;
1789 
1790 		error = VOP_IOCTL(sc->sc_parent->dk_rawvp, cmd, dsa, flag,
1791 		    l != NULL ? l->l_cred : NOCRED);
1792 		if (error)
1793 			break;
1794 
1795 		r = sc->sc_offset % dsa->dsa_alignment;
1796 		if (r < dsa->dsa_firstaligned)
1797 			dsa->dsa_firstaligned = dsa->dsa_firstaligned - r;
1798 		else
1799 			dsa->dsa_firstaligned = (dsa->dsa_firstaligned +
1800 			    dsa->dsa_alignment) - r;
1801 		break;
1802 	}
1803 	default:
1804 		error = ENOTTY;
1805 	}
1806 
1807 	return error;
1808 }
1809 
1810 /*
1811  * dkdiscard:		[devsw entry point]
1812  *
1813  *	Perform a discard-range request on a wedge.
1814  */
1815 static int
dkdiscard(dev_t dev,off_t pos,off_t len)1816 dkdiscard(dev_t dev, off_t pos, off_t len)
1817 {
1818 	struct dkwedge_softc *sc = dkwedge_lookup(dev);
1819 	uint64_t size = dkwedge_size(sc);
1820 	unsigned shift;
1821 	off_t offset, maxlen;
1822 	int error;
1823 
1824 	KASSERT(sc != NULL);
1825 	KASSERT(sc->sc_dev != NULL);
1826 	KASSERT(sc->sc_state != DKW_STATE_LARVAL);
1827 	KASSERT(sc->sc_state != DKW_STATE_DEAD);
1828 	KASSERT(sc->sc_parent->dk_rawvp != NULL);
1829 
1830 	/* XXX check bounds on size/offset up front */
1831 	shift = (sc->sc_parent->dk_blkshift + DEV_BSHIFT);
1832 	KASSERT(__type_fit(off_t, size));
1833 	KASSERT(__type_fit(off_t, sc->sc_offset));
1834 	KASSERT(0 <= sc->sc_offset);
1835 	KASSERT(size <= (__type_max(off_t) >> shift));
1836 	KASSERT(sc->sc_offset <= ((__type_max(off_t) >> shift) - size));
1837 	offset = ((off_t)sc->sc_offset << shift);
1838 	maxlen = ((off_t)size << shift);
1839 
1840 	if (len > maxlen)
1841 		return EINVAL;
1842 	if (pos > (maxlen - len))
1843 		return EINVAL;
1844 
1845 	pos += offset;
1846 
1847 	vn_lock(sc->sc_parent->dk_rawvp, LK_EXCLUSIVE | LK_RETRY);
1848 	error = VOP_FDISCARD(sc->sc_parent->dk_rawvp, pos, len);
1849 	VOP_UNLOCK(sc->sc_parent->dk_rawvp);
1850 
1851 	return error;
1852 }
1853 
1854 /*
1855  * dksize:		[devsw entry point]
1856  *
1857  *	Query the size of a wedge for the purpose of performing a dump
1858  *	or for swapping to.
1859  */
1860 static int
dksize(dev_t dev)1861 dksize(dev_t dev)
1862 {
1863 	/*
1864 	 * Don't bother taking a reference because this is only used
1865 	 * either (a) while the device is open (for swap), or (b) while
1866 	 * any multiprocessing is quiescent (for crash dumps).
1867 	 */
1868 	struct dkwedge_softc *sc = dkwedge_lookup(dev);
1869 	uint64_t p_size;
1870 	int rv = -1;
1871 
1872 	if (sc == NULL)
1873 		return -1;
1874 	if (sc->sc_state != DKW_STATE_RUNNING)
1875 		return -1;
1876 
1877 	/* Our content type is static, no need to open the device. */
1878 
1879 	p_size = dkwedge_size(sc) << sc->sc_parent->dk_blkshift;
1880 	if (strcmp(sc->sc_ptype, DKW_PTYPE_SWAP) == 0) {
1881 		/* Saturate if we are larger than INT_MAX. */
1882 		if (p_size > INT_MAX)
1883 			rv = INT_MAX;
1884 		else
1885 			rv = (int)p_size;
1886 	}
1887 
1888 	return rv;
1889 }
1890 
1891 /*
1892  * dkdump:		[devsw entry point]
1893  *
1894  *	Perform a crash dump to a wedge.
1895  */
1896 static int
dkdump(dev_t dev,daddr_t blkno,void * va,size_t size)1897 dkdump(dev_t dev, daddr_t blkno, void *va, size_t size)
1898 {
1899 	/*
1900 	 * Don't bother taking a reference because this is only used
1901 	 * while any multiprocessing is quiescent.
1902 	 */
1903 	struct dkwedge_softc *sc = dkwedge_lookup(dev);
1904 	const struct bdevsw *bdev;
1905 	uint64_t p_size, p_offset;
1906 
1907 	if (sc == NULL)
1908 		return ENXIO;
1909 	if (sc->sc_state != DKW_STATE_RUNNING)
1910 		return ENXIO;
1911 
1912 	/* Our content type is static, no need to open the device. */
1913 
1914 	if (strcmp(sc->sc_ptype, DKW_PTYPE_SWAP) != 0 &&
1915 	    strcmp(sc->sc_ptype, DKW_PTYPE_RAID) != 0 &&
1916 	    strcmp(sc->sc_ptype, DKW_PTYPE_CGD) != 0)
1917 		return ENXIO;
1918 	if (size % DEV_BSIZE != 0)
1919 		return EINVAL;
1920 
1921 	p_offset = sc->sc_offset << sc->sc_parent->dk_blkshift;
1922 	p_size = dkwedge_size(sc) << sc->sc_parent->dk_blkshift;
1923 
1924 	if (blkno < 0 || blkno + size/DEV_BSIZE > p_size) {
1925 		printf("%s: blkno (%" PRIu64 ") + size / DEV_BSIZE (%zu) > "
1926 		    "p_size (%" PRIu64 ")\n", __func__, blkno,
1927 		    size/DEV_BSIZE, p_size);
1928 		return EINVAL;
1929 	}
1930 
1931 	bdev = bdevsw_lookup(sc->sc_pdev);
1932 	return (*bdev->d_dump)(sc->sc_pdev, blkno + p_offset, va, size);
1933 }
1934 
1935 /*
1936  * config glue
1937  */
1938 
1939 /*
1940  * dkwedge_find_partition
1941  *
1942  *	Find wedge corresponding to the specified parent name
1943  *	and offset/length.
1944  */
1945 static device_t
dkwedge_find_partition_acquire(device_t parent,daddr_t startblk,uint64_t nblks)1946 dkwedge_find_partition_acquire(device_t parent, daddr_t startblk,
1947     uint64_t nblks)
1948 {
1949 	struct dkwedge_softc *sc;
1950 	int i;
1951 	device_t wedge = NULL;
1952 
1953 	rw_enter(&dkwedges_lock, RW_READER);
1954 	for (i = 0; i < ndkwedges; i++) {
1955 		if ((sc = dkwedges[i]) == NULL || sc->sc_dev == NULL)
1956 			continue;
1957 		if (strcmp(sc->sc_parent->dk_name, device_xname(parent)) == 0 &&
1958 		    sc->sc_offset == startblk &&
1959 		    dkwedge_size(sc) == nblks) {
1960 			if (wedge) {
1961 				printf("WARNING: double match for boot wedge "
1962 				    "(%s, %s)\n",
1963 				    device_xname(wedge),
1964 				    device_xname(sc->sc_dev));
1965 				continue;
1966 			}
1967 			wedge = sc->sc_dev;
1968 			device_acquire(wedge);
1969 		}
1970 	}
1971 	rw_exit(&dkwedges_lock);
1972 
1973 	return wedge;
1974 }
1975 
1976 /* XXX unsafe */
1977 device_t
dkwedge_find_partition(device_t parent,daddr_t startblk,uint64_t nblks)1978 dkwedge_find_partition(device_t parent, daddr_t startblk,
1979     uint64_t nblks)
1980 {
1981 	device_t dv;
1982 
1983 	if ((dv = dkwedge_find_partition_acquire(parent, startblk, nblks))
1984 	    == NULL)
1985 		return NULL;
1986 	device_release(dv);
1987 	return dv;
1988 }
1989 
1990 const char *
dkwedge_get_parent_name(dev_t dev)1991 dkwedge_get_parent_name(dev_t dev)
1992 {
1993 	/* XXX: perhaps do this in lookup? */
1994 	int bmaj = bdevsw_lookup_major(&dk_bdevsw);
1995 	int cmaj = cdevsw_lookup_major(&dk_cdevsw);
1996 
1997 	if (major(dev) != bmaj && major(dev) != cmaj)
1998 		return NULL;
1999 
2000 	struct dkwedge_softc *const sc = dkwedge_lookup_acquire(dev);
2001 	if (sc == NULL)
2002 		return NULL;
2003 	const char *const name = sc->sc_parent->dk_name;
2004 	device_release(sc->sc_dev);
2005 	return name;
2006 }
2007