xref: /freebsd/sys/geom/linux_lvm/g_linux_lvm.c (revision 830940567b49bb0c08dfaed40418999e76616909)
1 /*-
2  * Copyright (c) 2008 Andrew Thompson <thompsa@FreeBSD.org>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 #include <sys/ctype.h>
31 #include <sys/param.h>
32 #include <sys/bio.h>
33 #include <sys/kernel.h>
34 #include <sys/limits.h>
35 #include <sys/malloc.h>
36 #include <sys/queue.h>
37 #include <sys/sysctl.h>
38 #include <sys/systm.h>
39 
40 #include <geom/geom.h>
41 #include <sys/endian.h>
42 
43 #include <geom/linux_lvm/g_linux_lvm.h>
44 
45 /* Declare malloc(9) label */
46 static MALLOC_DEFINE(M_GLLVM, "gllvm", "GEOM_LINUX_LVM Data");
47 
48 /* GEOM class methods */
49 static g_access_t g_llvm_access;
50 static g_init_t g_llvm_init;
51 static g_orphan_t g_llvm_orphan;
52 static g_orphan_t g_llvm_taste_orphan;
53 static g_start_t g_llvm_start;
54 static g_taste_t g_llvm_taste;
55 static g_ctl_destroy_geom_t g_llvm_destroy_geom;
56 
57 static void	g_llvm_done(struct bio *);
58 static void	g_llvm_remove_disk(struct g_llvm_vg *, struct g_consumer *);
59 static int	g_llvm_activate_lv(struct g_llvm_vg *, struct g_llvm_lv *);
60 static int	g_llvm_add_disk(struct g_llvm_vg *, struct g_provider *, char *);
61 static void	g_llvm_free_vg(struct g_llvm_vg *);
62 static int	g_llvm_destroy(struct g_llvm_vg *, int);
63 static int	g_llvm_read_label(struct g_consumer *, struct g_llvm_label *);
64 static int	g_llvm_read_md(struct g_consumer *, struct g_llvm_metadata *,
65 		    struct g_llvm_label *);
66 
67 static int	llvm_label_decode(const u_char *, struct g_llvm_label *, int);
68 static int	llvm_md_decode(const u_char *, struct g_llvm_metadata *,
69 		    struct g_llvm_label *);
70 static int	llvm_textconf_decode(u_char *, int,
71 		    struct g_llvm_metadata *);
72 static int	llvm_textconf_decode_pv(char **, char *, struct g_llvm_vg *);
73 static int	llvm_textconf_decode_lv(char **, char *, struct g_llvm_vg *);
74 static int	llvm_textconf_decode_sg(char **, char *, struct g_llvm_lv *);
75 
76 SYSCTL_DECL(_kern_geom);
77 SYSCTL_NODE(_kern_geom, OID_AUTO, linux_lvm, CTLFLAG_RW, 0,
78     "GEOM_LINUX_LVM stuff");
79 static u_int g_llvm_debug = 0;
80 TUNABLE_INT("kern.geom.linux_lvm.debug", &g_llvm_debug);
81 SYSCTL_UINT(_kern_geom_linux_lvm, OID_AUTO, debug, CTLFLAG_RW, &g_llvm_debug, 0,
82     "Debug level");
83 
84 LIST_HEAD(, g_llvm_vg) vg_list;
85 
86 /*
87  * Called to notify geom when it's been opened, and for what intent
88  */
89 static int
90 g_llvm_access(struct g_provider *pp, int dr, int dw, int de)
91 {
92 	struct g_consumer *c;
93 	struct g_llvm_vg *vg;
94 	struct g_geom *gp;
95 	int error;
96 
97 	KASSERT(pp != NULL, ("%s: NULL provider", __func__));
98 	gp = pp->geom;
99 	KASSERT(gp != NULL, ("%s: NULL geom", __func__));
100 	vg = gp->softc;
101 
102 	if (vg == NULL) {
103 		/* It seems that .access can be called with negative dr,dw,dx
104 		 * in this case but I want to check for myself */
105 		G_LLVM_DEBUG(0, "access(%d, %d, %d) for %s",
106 		    dr, dw, de, pp->name);
107 
108 		/* This should only happen when geom is withered so
109 		 * allow only negative requests */
110 		KASSERT(dr <= 0 && dw <= 0 && de <= 0,
111 		    ("%s: Positive access for %s", __func__, pp->name));
112 		if (pp->acr + dr == 0 && pp->acw + dw == 0 && pp->ace + de == 0)
113 			G_LLVM_DEBUG(0,
114 			    "Device %s definitely destroyed", pp->name);
115 		return (0);
116 	}
117 
118 	/* Grab an exclusive bit to propagate on our consumers on first open */
119 	if (pp->acr == 0 && pp->acw == 0 && pp->ace == 0)
120 		de++;
121 	/* ... drop it on close */
122 	if (pp->acr + dr == 0 && pp->acw + dw == 0 && pp->ace + de == 0)
123 		de--;
124 
125 	error = ENXIO;
126 	LIST_FOREACH(c, &gp->consumer, consumer) {
127 		KASSERT(c != NULL, ("%s: consumer is NULL", __func__));
128 		error = g_access(c, dr, dw, de);
129 		if (error != 0) {
130 			struct g_consumer *c2;
131 
132 			/* Backout earlier changes */
133 			LIST_FOREACH(c2, &gp->consumer, consumer) {
134 				if (c2 == c) /* all eariler components fixed */
135 					return (error);
136 				g_access(c2, -dr, -dw, -de);
137 			}
138 		}
139 	}
140 
141 	return (error);
142 }
143 
144 /*
145  * Dismantle bio_queue and destroy its components
146  */
147 static void
148 bioq_dismantle(struct bio_queue_head *bq)
149 {
150 	struct bio *b;
151 
152 	for (b = bioq_first(bq); b != NULL; b = bioq_first(bq)) {
153 		bioq_remove(bq, b);
154 		g_destroy_bio(b);
155 	}
156 }
157 
158 /*
159  * GEOM .done handler
160  * Can't use standard handler because one requested IO may
161  * fork into additional data IOs
162  */
163 static void
164 g_llvm_done(struct bio *b)
165 {
166 	struct bio *parent_b;
167 
168 	parent_b = b->bio_parent;
169 
170 	if (b->bio_error != 0) {
171 		G_LLVM_DEBUG(0, "Error %d for offset=%ju, length=%ju on %s",
172 		    b->bio_error, b->bio_offset, b->bio_length,
173 		    b->bio_to->name);
174 		if (parent_b->bio_error == 0)
175 			parent_b->bio_error = b->bio_error;
176 	}
177 
178 	parent_b->bio_inbed++;
179 	parent_b->bio_completed += b->bio_completed;
180 
181 	if (parent_b->bio_children == parent_b->bio_inbed) {
182 		parent_b->bio_completed = parent_b->bio_length;
183 		g_io_deliver(parent_b, parent_b->bio_error);
184 	}
185 	g_destroy_bio(b);
186 }
187 
188 static void
189 g_llvm_start(struct bio *bp)
190 {
191 	struct g_provider *pp;
192 	struct g_llvm_vg *vg;
193 	struct g_llvm_pv *pv;
194 	struct g_llvm_lv *lv;
195 	struct g_llvm_segment *sg;
196 	struct bio *cb;
197 	struct bio_queue_head bq;
198 	size_t chunk_size;
199 	off_t offset, length;
200 	char *addr;
201 	u_int count;
202 
203 	pp = bp->bio_to;
204 	lv = pp->private;
205 	vg = pp->geom->softc;
206 
207 	switch (bp->bio_cmd) {
208 	case BIO_READ:
209 	case BIO_WRITE:
210 	case BIO_DELETE:
211 	/* XXX BIO_GETATTR allowed? */
212 		break;
213 	default:
214 		g_io_deliver(bp, EOPNOTSUPP);
215 		return;
216 	}
217 
218 	bioq_init(&bq);
219 
220 	chunk_size = vg->vg_extentsize;
221 	addr = bp->bio_data;
222 	offset = bp->bio_offset;	/* virtual offset and length */
223 	length = bp->bio_length;
224 
225 	while (length > 0) {
226 		size_t chunk_index, in_chunk_offset, in_chunk_length;
227 
228 		pv = NULL;
229 		cb = g_clone_bio(bp);
230 		if (cb == NULL) {
231 			bioq_dismantle(&bq);
232 			if (bp->bio_error == 0)
233 				bp->bio_error = ENOMEM;
234 			g_io_deliver(bp, bp->bio_error);
235 			return;
236 		}
237 
238 		/* get the segment and the pv */
239 		if (lv->lv_sgcount == 1) {
240 			/* skip much of the calculations for a single sg */
241 			chunk_index = 0;
242 			in_chunk_offset = 0;
243 			in_chunk_length = length;
244 			sg = lv->lv_firstsg;
245 			pv = sg->sg_pv;
246 			cb->bio_offset = offset + sg->sg_pvoffset;
247 		} else {
248 			chunk_index = offset / chunk_size; /* round downwards */
249 			in_chunk_offset = offset % chunk_size;
250 			in_chunk_length =
251 			    min(length, chunk_size - in_chunk_offset);
252 
253 			/* XXX could be faster */
254 			LIST_FOREACH(sg, &lv->lv_segs, sg_next) {
255 				if (chunk_index >= sg->sg_start &&
256 				    chunk_index <= sg->sg_end) {
257 					/* adjust chunk index for sg start */
258 					chunk_index -= sg->sg_start;
259 					pv = sg->sg_pv;
260 					break;
261 				}
262 			}
263 			cb->bio_offset =
264 			    (off_t)chunk_index * (off_t)chunk_size
265 			    + in_chunk_offset + sg->sg_pvoffset;
266 		}
267 
268 		KASSERT(pv != NULL, ("Can't find PV for chunk %zu",
269 		    chunk_index));
270 
271 		cb->bio_to = pv->pv_gprov;
272 		cb->bio_done = g_llvm_done;
273 		cb->bio_length = in_chunk_length;
274 		cb->bio_data = addr;
275 		cb->bio_caller1 = pv;
276 		bioq_disksort(&bq, cb);
277 
278 		G_LLVM_DEBUG(5,
279 		    "Mapped %s(%ju, %ju) on %s to %zu(%zu,%zu) @ %s:%ju",
280 		    bp->bio_cmd == BIO_READ ? "R" : "W",
281 		    offset, length, lv->lv_name,
282 		    chunk_index, in_chunk_offset, in_chunk_length,
283 		    pv->pv_name, cb->bio_offset);
284 
285 		addr += in_chunk_length;
286 		length -= in_chunk_length;
287 		offset += in_chunk_length;
288 	}
289 
290 	/* Fire off bio's here */
291 	count = 0;
292 	for (cb = bioq_first(&bq); cb != NULL; cb = bioq_first(&bq)) {
293 		bioq_remove(&bq, cb);
294 		pv = cb->bio_caller1;
295 		cb->bio_caller1 = NULL;
296 		G_LLVM_DEBUG(6, "firing bio to %s, offset=%ju, length=%ju",
297 		    cb->bio_to->name, cb->bio_offset, cb->bio_length);
298 		g_io_request(cb, pv->pv_gcons);
299 		count++;
300 	}
301 	if (count == 0) { /* We handled everything locally */
302 		bp->bio_completed = bp->bio_length;
303 		g_io_deliver(bp, 0);
304 	}
305 }
306 
307 static void
308 g_llvm_remove_disk(struct g_llvm_vg *vg, struct g_consumer *cp)
309 {
310 	struct g_llvm_pv *pv;
311 	struct g_llvm_lv *lv;
312 	struct g_llvm_segment *sg;
313 	int found;
314 
315 	KASSERT(cp != NULL, ("Non-valid disk in %s.", __func__));
316 	pv = (struct g_llvm_pv *)cp->private;
317 
318 	G_LLVM_DEBUG(0, "Disk %s removed from %s.", cp->provider->name,
319 	    pv->pv_name);
320 
321 	LIST_FOREACH(lv, &vg->vg_lvs, lv_next) {
322 		/* Find segments that map to this disk */
323 		found = 0;
324 		LIST_FOREACH(sg, &lv->lv_segs, sg_next) {
325 			if (sg->sg_pv == pv) {
326 				sg->sg_pv = NULL;
327 				lv->lv_sgactive--;
328 				found = 1;
329 				break;
330 			}
331 		}
332 		if (found) {
333 			G_LLVM_DEBUG(0, "Device %s removed.",
334 			    lv->lv_gprov->name);
335 			g_orphan_provider(lv->lv_gprov, ENXIO);
336 			lv->lv_gprov = NULL;
337 		}
338 	}
339 
340 	if (cp->acr > 0 || cp->acw > 0 || cp->ace > 0)
341 		g_access(cp, -cp->acr, -cp->acw, -cp->ace);
342 	g_detach(cp);
343 	g_destroy_consumer(cp);
344 }
345 
346 static void
347 g_llvm_orphan(struct g_consumer *cp)
348 {
349 	struct g_llvm_vg *vg;
350 	struct g_geom *gp;
351 
352 	g_topology_assert();
353 	gp = cp->geom;
354 	vg = gp->softc;
355 	if (vg == NULL)
356 		return;
357 
358 	g_llvm_remove_disk(vg, cp);
359 	g_llvm_destroy(vg, 1);
360 }
361 
362 static int
363 g_llvm_activate_lv(struct g_llvm_vg *vg, struct g_llvm_lv *lv)
364 {
365 	struct g_geom *gp;
366 	struct g_provider *pp;
367 
368 	g_topology_assert();
369 
370 	KASSERT(lv->lv_sgactive == lv->lv_sgcount, ("segment missing"));
371 
372 	gp = vg->vg_geom;
373 	pp = g_new_providerf(gp, "linux_lvm/%s-%s", vg->vg_name, lv->lv_name);
374 	pp->mediasize = vg->vg_extentsize * (off_t)lv->lv_extentcount;
375 	pp->sectorsize = vg->vg_sectorsize;
376 	g_error_provider(pp, 0);
377 	lv->lv_gprov = pp;
378 	pp->private = lv;
379 
380 	G_LLVM_DEBUG(1, "Created %s, %juM", pp->name,
381 	    pp->mediasize / (1024*1024));
382 
383 	return (0);
384 }
385 
386 static int
387 g_llvm_add_disk(struct g_llvm_vg *vg, struct g_provider *pp, char *uuid)
388 {
389 	struct g_geom *gp;
390 	struct g_consumer *cp, *fcp;
391 	struct g_llvm_pv *pv;
392 	struct g_llvm_lv *lv;
393 	struct g_llvm_segment *sg;
394 	int error;
395 
396 	g_topology_assert();
397 
398 	LIST_FOREACH(pv, &vg->vg_pvs, pv_next) {
399 		if (strcmp(pv->pv_uuid, uuid) == 0)
400 			break;	/* found it */
401 	}
402 	if (pv == NULL) {
403 		G_LLVM_DEBUG(3, "uuid %s not found in pv list", uuid);
404 		return (ENOENT);
405 	}
406 	if (pv->pv_gprov != NULL) {
407 		G_LLVM_DEBUG(0, "disk %s already initialised in %s",
408 		    pv->pv_name, vg->vg_name);
409 		return (EEXIST);
410 	}
411 
412 	pv->pv_start *= vg->vg_sectorsize;
413 	gp = vg->vg_geom;
414 	fcp = LIST_FIRST(&gp->consumer);
415 
416 	cp = g_new_consumer(gp);
417 	error = g_attach(cp, pp);
418 	G_LLVM_DEBUG(1, "Attached %s to %s at offset %ju",
419 	    pp->name, pv->pv_name, pv->pv_start);
420 
421 	if (error != 0) {
422 		G_LLVM_DEBUG(0, "cannot attach %s to %s",
423 		    pp->name, vg->vg_name);
424 		g_destroy_consumer(cp);
425 		return (error);
426 	}
427 
428 	if (fcp != NULL) {
429 		if (fcp->provider->sectorsize != pp->sectorsize) {
430 			G_LLVM_DEBUG(0, "Provider %s of %s has invalid "
431 			    "sector size (%d)", pp->name, vg->vg_name,
432 			    pp->sectorsize);
433 			return (EINVAL);
434 		}
435 		if (fcp->acr > 0 || fcp->acw || fcp->ace > 0) {
436 			/* Replicate access permissions from first "live"
437 			 * consumer to the new one */
438 			error = g_access(cp, fcp->acr, fcp->acw, fcp->ace);
439 			if (error != 0) {
440 				g_detach(cp);
441 				g_destroy_consumer(cp);
442 				return (error);
443 			}
444 		}
445 	}
446 
447 	cp->private = pv;
448 	pv->pv_gcons = cp;
449 	pv->pv_gprov = pp;
450 
451 	LIST_FOREACH(lv, &vg->vg_lvs, lv_next) {
452 		/* Find segments that map to this disk */
453 		LIST_FOREACH(sg, &lv->lv_segs, sg_next) {
454 			if (strcmp(sg->sg_pvname, pv->pv_name) == 0) {
455 				/* avtivate the segment */
456 				KASSERT(sg->sg_pv == NULL,
457 				    ("segment already mapped"));
458 				sg->sg_pvoffset =
459 				    (off_t)sg->sg_pvstart * vg->vg_extentsize
460 				    + pv->pv_start;
461 				sg->sg_pv = pv;
462 				lv->lv_sgactive++;
463 
464 				G_LLVM_DEBUG(2, "%s: %d to %d @ %s:%d"
465 				    " offset %ju sector %ju",
466 				    lv->lv_name, sg->sg_start, sg->sg_end,
467 				    sg->sg_pvname, sg->sg_pvstart,
468 				    sg->sg_pvoffset,
469 				    sg->sg_pvoffset / vg->vg_sectorsize);
470 			}
471 		}
472 		/* Activate any lvs waiting on this disk */
473 		if (lv->lv_gprov == NULL && lv->lv_sgactive == lv->lv_sgcount) {
474 			error = g_llvm_activate_lv(vg, lv);
475 			if (error)
476 				break;
477 		}
478 	}
479 	return (error);
480 }
481 
482 static void
483 g_llvm_init(struct g_class *mp)
484 {
485 	LIST_INIT(&vg_list);
486 }
487 
488 static void
489 g_llvm_free_vg(struct g_llvm_vg *vg)
490 {
491 	struct g_llvm_pv *pv;
492 	struct g_llvm_lv *lv;
493 	struct g_llvm_segment *sg;
494 
495 	/* Free all the structures */
496 	while ((pv = LIST_FIRST(&vg->vg_pvs)) != NULL) {
497 		LIST_REMOVE(pv, pv_next);
498 		free(pv, M_GLLVM);
499 	}
500 	while ((lv = LIST_FIRST(&vg->vg_lvs)) != NULL) {
501 		while ((sg = LIST_FIRST(&lv->lv_segs)) != NULL) {
502 			LIST_REMOVE(sg, sg_next);
503 			free(sg, M_GLLVM);
504 		}
505 		LIST_REMOVE(lv, lv_next);
506 		free(lv, M_GLLVM);
507 	}
508 	LIST_REMOVE(vg, vg_next);
509 	free(vg, M_GLLVM);
510 }
511 
512 static void
513 g_llvm_taste_orphan(struct g_consumer *cp)
514 {
515 
516 	KASSERT(1 == 0, ("%s called while tasting %s.", __func__,
517 	    cp->provider->name));
518 }
519 
520 static struct g_geom *
521 g_llvm_taste(struct g_class *mp, struct g_provider *pp, int flags __unused)
522 {
523 	struct g_consumer *cp;
524 	struct g_geom *gp;
525 	struct g_llvm_label ll;
526 	struct g_llvm_metadata md;
527 	struct g_llvm_vg *vg;
528 	int error;
529 
530 	bzero(&md, sizeof(md));
531 
532 	g_topology_assert();
533 	g_trace(G_T_TOPOLOGY, "%s(%s, %s)", __func__, mp->name, pp->name);
534 	gp = g_new_geomf(mp, "linux_lvm:taste");
535 	/* This orphan function should be never called. */
536 	gp->orphan = g_llvm_taste_orphan;
537 	cp = g_new_consumer(gp);
538 	g_attach(cp, pp);
539 	error = g_llvm_read_label(cp, &ll);
540 	if (!error)
541 		error = g_llvm_read_md(cp, &md, &ll);
542 	g_detach(cp);
543 	g_destroy_consumer(cp);
544 	g_destroy_geom(gp);
545 	if (error != 0)
546 		return (NULL);
547 
548 	vg = md.md_vg;
549 	if (vg->vg_geom == NULL) {
550 		/* new volume group */
551 		gp = g_new_geomf(mp, "%s", vg->vg_name);
552 		gp->start = g_llvm_start;
553 		gp->spoiled = g_llvm_orphan;
554 		gp->orphan = g_llvm_orphan;
555 		gp->access = g_llvm_access;
556 		vg->vg_sectorsize = pp->sectorsize;
557 		vg->vg_extentsize *= vg->vg_sectorsize;
558 		vg->vg_geom = gp;
559 		gp->softc = vg;
560 		G_LLVM_DEBUG(1, "Created volume %s, extent size %zuK",
561 		    vg->vg_name, vg->vg_extentsize / 1024);
562 	}
563 
564 	/* initialise this disk in the volume group */
565 	g_llvm_add_disk(vg, pp, ll.ll_uuid);
566 	return (vg->vg_geom);
567 }
568 
569 static int
570 g_llvm_destroy(struct g_llvm_vg *vg, int force)
571 {
572 	struct g_provider *pp;
573 	struct g_geom *gp;
574 
575 	g_topology_assert();
576 	if (vg == NULL)
577 		return (ENXIO);
578 	gp = vg->vg_geom;
579 
580 	LIST_FOREACH(pp, &gp->provider, provider) {
581 		if (pp->acr != 0 || pp->acw != 0 || pp->ace != 0) {
582 			G_LLVM_DEBUG(1, "Device %s is still open (r%dw%de%d)",
583 			    pp->name, pp->acr, pp->acw, pp->ace);
584 			if (!force)
585 				return (EBUSY);
586 		}
587 	}
588 
589 	g_llvm_free_vg(gp->softc);
590 	gp->softc = NULL;
591 	g_wither_geom(gp, ENXIO);
592 	return (0);
593 }
594 
595 static int
596 g_llvm_destroy_geom(struct gctl_req *req __unused, struct g_class *mp __unused,
597     struct g_geom *gp)
598 {
599 	struct g_llvm_vg *vg;
600 
601 	vg = gp->softc;
602 	return (g_llvm_destroy(vg, 0));
603 }
604 
605 int
606 g_llvm_read_label(struct g_consumer *cp, struct g_llvm_label *ll)
607 {
608 	struct g_provider *pp;
609 	u_char *buf;
610 	int i, error = 0;
611 
612 	g_topology_assert();
613 
614 	/* The LVM label is stored on the first four sectors */
615 	error = g_access(cp, 1, 0, 0);
616 	if (error != 0)
617 		return (error);
618 	pp = cp->provider;
619 	g_topology_unlock();
620 	buf = g_read_data(cp, 0, pp->sectorsize * 4, &error);
621 	g_topology_lock();
622 	g_access(cp, -1, 0, 0);
623 	if (buf == NULL) {
624 		G_LLVM_DEBUG(1, "Cannot read metadata from %s (error=%d)",
625 		    pp->name, error);
626 		return (error);
627 	}
628 
629 	/* Search the four sectors for the LVM label. */
630 	for (i = 0; i < 4; i++) {
631 		error = llvm_label_decode(&buf[i * pp->sectorsize], ll, i);
632 		if (error == 0)
633 			break;	/* found it */
634 	}
635 	g_free(buf);
636 	return (error);
637 }
638 
639 int
640 g_llvm_read_md(struct g_consumer *cp, struct g_llvm_metadata *md,
641     struct g_llvm_label *ll)
642 {
643 	struct g_provider *pp;
644 	u_char *buf;
645 	int error;
646 	int size;
647 
648 	g_topology_assert();
649 
650 	error = g_access(cp, 1, 0, 0);
651 	if (error != 0)
652 		return (error);
653 	pp = cp->provider;
654 	g_topology_unlock();
655 	buf = g_read_data(cp, ll->ll_md_offset, pp->sectorsize, &error);
656 	g_topology_lock();
657 	g_access(cp, -1, 0, 0);
658 	if (buf == NULL) {
659 		G_LLVM_DEBUG(0, "Cannot read metadata from %s (error=%d)",
660 		    cp->provider->name, error);
661 		return (error);
662 	}
663 
664 	error = llvm_md_decode(buf, md, ll);
665 	g_free(buf);
666 	if (error != 0) {
667 		return (error);
668 	}
669 
670 	G_LLVM_DEBUG(1, "reading LVM2 config @ %s:%ju", pp->name,
671 		    ll->ll_md_offset + md->md_reloffset);
672 	error = g_access(cp, 1, 0, 0);
673 	if (error != 0)
674 		return (error);
675 	pp = cp->provider;
676 	g_topology_unlock();
677 	/* round up to the nearest sector */
678 	size = md->md_relsize +
679 	    (pp->sectorsize - md->md_relsize % pp->sectorsize);
680 	buf = g_read_data(cp, ll->ll_md_offset + md->md_reloffset, size, &error);
681 	g_topology_lock();
682 	g_access(cp, -1, 0, 0);
683 	if (buf == NULL) {
684 		G_LLVM_DEBUG(0, "Cannot read LVM2 config from %s (error=%d)",
685 		    pp->name, error);
686 		return (error);
687 	}
688 	buf[md->md_relsize] = '\0';
689 	G_LLVM_DEBUG(10, "LVM config:\n%s\n", buf);
690 	error = llvm_textconf_decode(buf, md->md_relsize, md);
691 	g_free(buf);
692 
693 	return (error);
694 }
695 
696 static int
697 llvm_label_decode(const u_char *data, struct g_llvm_label *ll, int sector)
698 {
699 	uint64_t off;
700 	char *uuid;
701 
702 	/* Magic string */
703 	if (bcmp("LABELONE", data , 8) != 0)
704 		return (EINVAL);
705 
706 	/* We only support LVM2 text format */
707 	if (bcmp("LVM2 001", data + 24, 8) != 0) {
708 		G_LLVM_DEBUG(0, "Unsupported LVM format");
709 		return (EINVAL);
710 	}
711 
712 	ll->ll_sector = le64dec(data + 8);
713 	ll->ll_crc = le32dec(data + 16);
714 	ll->ll_offset = le32dec(data + 20);
715 
716 	if (ll->ll_sector != sector) {
717 		G_LLVM_DEBUG(0, "Expected sector %ju, found at %d",
718 		    ll->ll_sector, sector);
719 		return (EINVAL);
720 	}
721 
722 	off = ll->ll_offset;
723 	/*
724 	 * convert the binary uuid to string format, the format is
725 	 * xxxxxx-xxxx-xxxx-xxxx-xxxx-xxxx-xxxxxx (6-4-4-4-4-4-6)
726 	 */
727 	uuid = ll->ll_uuid;
728 	bcopy(data + off, uuid, 6);
729 	off += 6;
730 	uuid += 6;
731 	*uuid++ = '-';
732 	for (int i = 0; i < 5; i++) {
733 		bcopy(data + off, uuid, 4);
734 		off += 4;
735 		uuid += 4;
736 		*uuid++ = '-';
737 	}
738 	bcopy(data + off, uuid, 6);
739 	off += 6;
740 	uuid += 6;
741 	*uuid++ = '\0';
742 
743 	ll->ll_size = le64dec(data + off);
744 	off += 8;
745 	ll->ll_pestart = le64dec(data + off);
746 	off += 16;
747 
748 	/* Only one data section is supported */
749 	if (le64dec(data + off) != 0) {
750 		G_LLVM_DEBUG(0, "Only one data section supported");
751 		return (EINVAL);
752 	}
753 
754 	off += 16;
755 	ll->ll_md_offset = le64dec(data + off);
756 	off += 8;
757 	ll->ll_md_size = le64dec(data + off);
758 	off += 8;
759 
760 	G_LLVM_DEBUG(1, "LVM metadata: offset=%ju, size=%ju", ll->ll_md_offset,
761 	    ll->ll_md_size);
762 
763 	/* Only one data section is supported */
764 	if (le64dec(data + off) != 0) {
765 		G_LLVM_DEBUG(0, "Only one metadata section supported");
766 		return (EINVAL);
767 	}
768 
769 	G_LLVM_DEBUG(2, "label uuid=%s", ll->ll_uuid);
770 	G_LLVM_DEBUG(2, "sector=%ju, crc=%u, offset=%u, size=%ju, pestart=%ju",
771 	    ll->ll_sector, ll->ll_crc, ll->ll_offset, ll->ll_size,
772 	    ll->ll_pestart);
773 
774 	return (0);
775 }
776 
777 static int
778 llvm_md_decode(const u_char *data, struct g_llvm_metadata *md,
779     struct g_llvm_label *ll)
780 {
781 	uint64_t off;
782 	char magic[16];
783 
784 	off = 0;
785 	md->md_csum = le32dec(data + off);
786 	off += 4;
787 	bcopy(data + off, magic, 16);
788 	off += 16;
789 	md->md_version = le32dec(data + off);
790 	off += 4;
791 	md->md_start = le64dec(data + off);
792 	off += 8;
793 	md->md_size = le64dec(data + off);
794 	off += 8;
795 
796 	if (bcmp(G_LLVM_MAGIC, magic, 16) != 0) {
797 		G_LLVM_DEBUG(0, "Incorrect md magic number");
798 		return (EINVAL);
799 	}
800 	if (md->md_version != 1) {
801 		G_LLVM_DEBUG(0, "Incorrect md version number (%u)",
802 		    md->md_version);
803 		return (EINVAL);
804 	}
805 	if (md->md_start != ll->ll_md_offset) {
806 		G_LLVM_DEBUG(0, "Incorrect md offset (%ju)", md->md_start);
807 		return (EINVAL);
808 	}
809 
810 	/* Aparently only one is ever returned */
811 	md->md_reloffset = le64dec(data + off);
812 	off += 8;
813 	md->md_relsize = le64dec(data + off);
814 	off += 16;	/* XXX skipped checksum */
815 
816 	if (le64dec(data + off) != 0) {
817 		G_LLVM_DEBUG(0, "Only one reloc supported");
818 		return (EINVAL);
819 	}
820 
821 	G_LLVM_DEBUG(3, "reloc: offset=%ju, size=%ju",
822 	    md->md_reloffset, md->md_relsize);
823 	G_LLVM_DEBUG(3, "md: version=%u, start=%ju, size=%ju",
824 	    md->md_version, md->md_start, md->md_size);
825 
826 	return (0);
827 }
828 
829 #define	GRAB_INT(key, tok1, tok2, v)					\
830 	if (tok1 && tok2 && strncmp(tok1, key, sizeof(key)) == 0) {	\
831 		v = strtol(tok2, &tok1, 10);				\
832 		if (tok1 == tok2)					\
833 			/* strtol did not eat any of the buffer */	\
834 			goto bad;					\
835 		continue;						\
836 	}
837 
838 #define	GRAB_STR(key, tok1, tok2, v, len)				\
839 	if (tok1 && tok2 && strncmp(tok1, key, sizeof(key)) == 0) {	\
840 		strsep(&tok2, "\"");					\
841 		if (tok2 == NULL)					\
842 			continue;					\
843 		tok1 = strsep(&tok2, "\"");				\
844 		if (tok2 == NULL)					\
845 			continue;					\
846 		strncpy(v, tok1, len);					\
847 		continue;						\
848 	}
849 
850 #define	SPLIT(key, value, str)						\
851 	key = strsep(&value, str);					\
852 	/* strip trailing whitespace on the key */			\
853 	for (char *t = key; *t != '\0'; t++)				\
854 		if (isspace(*t)) {					\
855 			*t = '\0';					\
856 			break;						\
857 		}
858 
859 static size_t
860 llvm_grab_name(char *name, const char *tok)
861 {
862 	size_t len;
863 
864 	len = 0;
865 	if (tok == NULL)
866 		return (0);
867 	if (tok[0] == '-')
868 		return (0);
869 	if (strcmp(tok, ".") == 0 || strcmp(tok, "..") == 0)
870 		return (0);
871 	while (tok[len] && (isalpha(tok[len]) || isdigit(tok[len]) ||
872 	    tok[len] == '.' || tok[len] == '_' || tok[len] == '-' ||
873 	    tok[len] == '+') && len < G_LLVM_NAMELEN - 1)
874 		len++;
875 	bcopy(tok, name, len);
876 	name[len] = '\0';
877 	return (len);
878 }
879 
880 static int
881 llvm_textconf_decode(u_char *data, int buflen, struct g_llvm_metadata *md)
882 {
883 	struct g_llvm_vg	*vg;
884 	char *buf = data;
885 	char *tok, *v;
886 	char name[G_LLVM_NAMELEN];
887 	char uuid[G_LLVM_UUIDLEN];
888 	size_t len;
889 
890 	if (buf == NULL || *buf == '\0')
891 		return (EINVAL);
892 
893 	tok = strsep(&buf, "\n");
894 	if (tok == NULL)
895 		return (EINVAL);
896 	len = llvm_grab_name(name, tok);
897 	if (len == 0)
898 		return (EINVAL);
899 
900 	/* check too see if the vg has already been loaded off another disk */
901 	LIST_FOREACH(vg, &vg_list, vg_next) {
902 		if (strcmp(vg->vg_name, name) == 0) {
903 			uuid[0] = '\0';
904 			/* grab the volume group uuid */
905 			while ((tok = strsep(&buf, "\n")) != NULL) {
906 				if (strstr(tok, "{"))
907 					break;
908 				if (strstr(tok, "=")) {
909 					SPLIT(v, tok, "=");
910 					GRAB_STR("id", v, tok, uuid,
911 					    sizeof(uuid));
912 				}
913 			}
914 			if (strcmp(vg->vg_uuid, uuid) == 0) {
915 				/* existing vg */
916 				md->md_vg = vg;
917 				return (0);
918 			}
919 			/* XXX different volume group with name clash! */
920 			G_LLVM_DEBUG(0,
921 			    "%s already exists, volume group not loaded", name);
922 			return (EINVAL);
923 		}
924 	}
925 
926 	vg = malloc(sizeof(*vg), M_GLLVM, M_NOWAIT|M_ZERO);
927 	if (vg == NULL)
928 		return (ENOMEM);
929 
930 	strncpy(vg->vg_name, name, sizeof(vg->vg_name));
931 	LIST_INIT(&vg->vg_pvs);
932 	LIST_INIT(&vg->vg_lvs);
933 
934 #define	VOL_FOREACH(func, tok, buf, p)					\
935 	while ((tok = strsep(buf, "\n")) != NULL) {			\
936 		if (strstr(tok, "{")) {					\
937 			func(buf, tok, p);				\
938 			continue;					\
939 		}							\
940 		if (strstr(tok, "}"))					\
941 			break;						\
942 	}
943 
944 	while ((tok = strsep(&buf, "\n")) != NULL) {
945 		if (strcmp(tok, "physical_volumes {") == 0) {
946 			VOL_FOREACH(llvm_textconf_decode_pv, tok, &buf, vg);
947 			continue;
948 		}
949 		if (strcmp(tok, "logical_volumes {") == 0) {
950 			VOL_FOREACH(llvm_textconf_decode_lv, tok, &buf, vg);
951 			continue;
952 		}
953 		if (strstr(tok, "{")) {
954 			G_LLVM_DEBUG(2, "unknown section %s", tok);
955 			continue;
956 		}
957 
958 		/* parse 'key = value' lines */
959 		if (strstr(tok, "=")) {
960 			SPLIT(v, tok, "=");
961 			GRAB_STR("id", v, tok, vg->vg_uuid, sizeof(vg->vg_uuid));
962 			GRAB_INT("extent_size", v, tok, vg->vg_extentsize);
963 			continue;
964 		}
965 	}
966 	/* basic checking */
967 	if (vg->vg_extentsize == 0)
968 		goto bad;
969 
970 	md->md_vg = vg;
971 	LIST_INSERT_HEAD(&vg_list, vg, vg_next);
972 	G_LLVM_DEBUG(3, "vg: name=%s uuid=%s", vg->vg_name, vg->vg_uuid);
973 	return(0);
974 
975 bad:
976 	g_llvm_free_vg(vg);
977 	return (-1);
978 }
979 #undef	VOL_FOREACH
980 
981 static int
982 llvm_textconf_decode_pv(char **buf, char *tok, struct g_llvm_vg *vg)
983 {
984 	struct g_llvm_pv	*pv;
985 	char *v;
986 	size_t len;
987 
988 	if (*buf == NULL || **buf == '\0')
989 		return (EINVAL);
990 
991 	pv = malloc(sizeof(*pv), M_GLLVM, M_NOWAIT|M_ZERO);
992 	if (pv == NULL)
993 		return (ENOMEM);
994 
995 	pv->pv_vg = vg;
996 	len = 0;
997 	if (tok == NULL)
998 		goto bad;
999 	len = llvm_grab_name(pv->pv_name, tok);
1000 	if (len == 0)
1001 		goto bad;
1002 
1003 	while ((tok = strsep(buf, "\n")) != NULL) {
1004 		if (strstr(tok, "{"))
1005 			goto bad;
1006 
1007 		if (strstr(tok, "}"))
1008 			break;
1009 
1010 		/* parse 'key = value' lines */
1011 		if (strstr(tok, "=")) {
1012 			SPLIT(v, tok, "=");
1013 			GRAB_STR("id", v, tok, pv->pv_uuid, sizeof(pv->pv_uuid));
1014 			GRAB_INT("pe_start", v, tok, pv->pv_start);
1015 			GRAB_INT("pe_count", v, tok, pv->pv_count);
1016 			continue;
1017 		}
1018 	}
1019 	if (tok == NULL)
1020 		goto bad;
1021 	/* basic checking */
1022 	if (pv->pv_count == 0)
1023 		goto bad;
1024 
1025 	LIST_INSERT_HEAD(&vg->vg_pvs, pv, pv_next);
1026 	G_LLVM_DEBUG(3, "pv: name=%s uuid=%s", pv->pv_name, pv->pv_uuid);
1027 
1028 	return (0);
1029 bad:
1030 	free(pv, M_GLLVM);
1031 	return (-1);
1032 }
1033 
1034 static int
1035 llvm_textconf_decode_lv(char **buf, char *tok, struct g_llvm_vg *vg)
1036 {
1037 	struct g_llvm_lv	*lv;
1038 	struct g_llvm_segment *sg;
1039 	char *v;
1040 	size_t len;
1041 
1042 	if (*buf == NULL || **buf == '\0')
1043 		return (EINVAL);
1044 
1045 	lv = malloc(sizeof(*lv), M_GLLVM, M_NOWAIT|M_ZERO);
1046 	if (lv == NULL)
1047 		return (ENOMEM);
1048 
1049 	lv->lv_vg = vg;
1050 	LIST_INIT(&lv->lv_segs);
1051 
1052 	if (tok == NULL)
1053 		goto bad;
1054 	len = llvm_grab_name(lv->lv_name, tok);
1055 	if (len == 0)
1056 		goto bad;
1057 
1058 	while ((tok = strsep(buf, "\n")) != NULL) {
1059 		if (strstr(tok, "{")) {
1060 			if (strstr(tok, "segment")) {
1061 				llvm_textconf_decode_sg(buf, tok, lv);
1062 				continue;
1063 			} else
1064 				/* unexpected section */
1065 				goto bad;
1066 		}
1067 
1068 		if (strstr(tok, "}"))
1069 			break;
1070 
1071 		/* parse 'key = value' lines */
1072 		if (strstr(tok, "=")) {
1073 			SPLIT(v, tok, "=");
1074 			GRAB_STR("id", v, tok, lv->lv_uuid, sizeof(lv->lv_uuid));
1075 			GRAB_INT("segment_count", v, tok, lv->lv_sgcount);
1076 			continue;
1077 		}
1078 	}
1079 	if (tok == NULL)
1080 		goto bad;
1081 	if (lv->lv_sgcount == 0 || lv->lv_sgcount != lv->lv_numsegs)
1082 		/* zero or incomplete segment list */
1083 		goto bad;
1084 
1085 	/* Optimize for only one segment on the pv */
1086 	lv->lv_firstsg = LIST_FIRST(&lv->lv_segs);
1087 	LIST_INSERT_HEAD(&vg->vg_lvs, lv, lv_next);
1088 	G_LLVM_DEBUG(3, "lv: name=%s uuid=%s", lv->lv_name, lv->lv_uuid);
1089 
1090 	return (0);
1091 bad:
1092 	while ((sg = LIST_FIRST(&lv->lv_segs)) != NULL) {
1093 		LIST_REMOVE(sg, sg_next);
1094 		free(sg, M_GLLVM);
1095 	}
1096 	free(lv, M_GLLVM);
1097 	return (-1);
1098 }
1099 
1100 static int
1101 llvm_textconf_decode_sg(char **buf, char *tok, struct g_llvm_lv *lv)
1102 {
1103 	struct g_llvm_segment *sg;
1104 	char *v;
1105 	int count = 0;
1106 
1107 	if (*buf == NULL || **buf == '\0')
1108 		return (EINVAL);
1109 
1110 	sg = malloc(sizeof(*sg), M_GLLVM, M_NOWAIT|M_ZERO);
1111 	if (sg == NULL)
1112 		return (ENOMEM);
1113 
1114 	while ((tok = strsep(buf, "\n")) != NULL) {
1115 		/* only a single linear stripe is supported */
1116 		if (strstr(tok, "stripe_count")) {
1117 			SPLIT(v, tok, "=");
1118 			GRAB_INT("stripe_count", v, tok, count);
1119 			if (count != 1)
1120 				goto bad;
1121 		}
1122 
1123 		if (strstr(tok, "{"))
1124 			goto bad;
1125 
1126 		if (strstr(tok, "}"))
1127 			break;
1128 
1129 		if (strcmp(tok, "stripes = [") == 0) {
1130 			tok = strsep(buf, "\n");
1131 			if (tok == NULL)
1132 				goto bad;
1133 
1134 			strsep(&tok, "\"");
1135 			if (tok == NULL)
1136 				goto bad;	/* missing open quotes */
1137 			v = strsep(&tok, "\"");
1138 			if (tok == NULL)
1139 				goto bad;	/* missing close quotes */
1140 			strncpy(sg->sg_pvname, v, sizeof(sg->sg_pvname));
1141 			if (*tok != ',')
1142 				goto bad;	/* missing comma for stripe */
1143 			tok++;
1144 
1145 			sg->sg_pvstart = strtol(tok, &v, 10);
1146 			if (v == tok)
1147 				/* strtol did not eat any of the buffer */
1148 				goto bad;
1149 
1150 			continue;
1151 		}
1152 
1153 		/* parse 'key = value' lines */
1154 		if (strstr(tok, "=")) {
1155 			SPLIT(v, tok, "=");
1156 			GRAB_INT("start_extent", v, tok, sg->sg_start);
1157 			GRAB_INT("extent_count", v, tok, sg->sg_count);
1158 			continue;
1159 		}
1160 	}
1161 	if (tok == NULL)
1162 		goto bad;
1163 	/* basic checking */
1164 	if (count != 1 || sg->sg_count == 0)
1165 		goto bad;
1166 
1167 	sg->sg_end = sg->sg_start + sg->sg_count - 1;
1168 	lv->lv_numsegs++;
1169 	lv->lv_extentcount += sg->sg_count;
1170 	LIST_INSERT_HEAD(&lv->lv_segs, sg, sg_next);
1171 
1172 	return (0);
1173 bad:
1174 	free(sg, M_GLLVM);
1175 	return (-1);
1176 }
1177 #undef	GRAB_INT
1178 #undef	GRAB_STR
1179 #undef	SPLIT
1180 
1181 static struct g_class g_llvm_class = {
1182 	.name = G_LLVM_CLASS_NAME,
1183 	.version = G_VERSION,
1184 	.init = g_llvm_init,
1185 	.taste = g_llvm_taste,
1186 	.destroy_geom = g_llvm_destroy_geom
1187 };
1188 
1189 DECLARE_GEOM_CLASS(g_llvm_class, g_linux_lvm);
1190