xref: /freebsd/sys/geom/part/g_part_ebr.c (revision d0ba1baed3f6e4936a0c1b89c25f6c59168ef6de)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2007-2009 Marcel Moolenaar
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  *
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 #include "opt_geom.h"
30 
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD$");
33 
34 #include <sys/param.h>
35 #include <sys/bio.h>
36 #include <sys/diskmbr.h>
37 #include <sys/endian.h>
38 #include <sys/kernel.h>
39 #include <sys/kobj.h>
40 #include <sys/limits.h>
41 #include <sys/lock.h>
42 #include <sys/malloc.h>
43 #include <sys/mutex.h>
44 #include <sys/queue.h>
45 #include <sys/sbuf.h>
46 #include <sys/systm.h>
47 #include <sys/sysctl.h>
48 #include <geom/geom.h>
49 #include <geom/part/g_part.h>
50 
51 #include "g_part_if.h"
52 
53 FEATURE(geom_part_ebr,
54     "GEOM partitioning class for extended boot records support");
55 #if defined(GEOM_PART_EBR_COMPAT)
56 FEATURE(geom_part_ebr_compat,
57     "GEOM EBR partitioning class: backward-compatible partition names");
58 #endif
59 
60 #define	EBRSIZE		512
61 
62 struct g_part_ebr_table {
63 	struct g_part_table	base;
64 #ifndef GEOM_PART_EBR_COMPAT
65 	u_char		ebr[EBRSIZE];
66 #endif
67 };
68 
69 struct g_part_ebr_entry {
70 	struct g_part_entry	base;
71 	struct dos_partition	ent;
72 };
73 
74 static int g_part_ebr_add(struct g_part_table *, struct g_part_entry *,
75     struct g_part_parms *);
76 static int g_part_ebr_create(struct g_part_table *, struct g_part_parms *);
77 static int g_part_ebr_destroy(struct g_part_table *, struct g_part_parms *);
78 static void g_part_ebr_dumpconf(struct g_part_table *, struct g_part_entry *,
79     struct sbuf *, const char *);
80 static int g_part_ebr_dumpto(struct g_part_table *, struct g_part_entry *);
81 #if defined(GEOM_PART_EBR_COMPAT)
82 static void g_part_ebr_fullname(struct g_part_table *, struct g_part_entry *,
83     struct sbuf *, const char *);
84 #endif
85 static int g_part_ebr_modify(struct g_part_table *, struct g_part_entry *,
86     struct g_part_parms *);
87 static const char *g_part_ebr_name(struct g_part_table *, struct g_part_entry *,
88     char *, size_t);
89 static int g_part_ebr_precheck(struct g_part_table *, enum g_part_ctl,
90     struct g_part_parms *);
91 static int g_part_ebr_probe(struct g_part_table *, struct g_consumer *);
92 static int g_part_ebr_read(struct g_part_table *, struct g_consumer *);
93 static int g_part_ebr_setunset(struct g_part_table *, struct g_part_entry *,
94     const char *, unsigned int);
95 static const char *g_part_ebr_type(struct g_part_table *, struct g_part_entry *,
96     char *, size_t);
97 static int g_part_ebr_write(struct g_part_table *, struct g_consumer *);
98 static int g_part_ebr_resize(struct g_part_table *, struct g_part_entry *,
99     struct g_part_parms *);
100 
101 static kobj_method_t g_part_ebr_methods[] = {
102 	KOBJMETHOD(g_part_add,		g_part_ebr_add),
103 	KOBJMETHOD(g_part_create,	g_part_ebr_create),
104 	KOBJMETHOD(g_part_destroy,	g_part_ebr_destroy),
105 	KOBJMETHOD(g_part_dumpconf,	g_part_ebr_dumpconf),
106 	KOBJMETHOD(g_part_dumpto,	g_part_ebr_dumpto),
107 #if defined(GEOM_PART_EBR_COMPAT)
108 	KOBJMETHOD(g_part_fullname,	g_part_ebr_fullname),
109 #endif
110 	KOBJMETHOD(g_part_modify,	g_part_ebr_modify),
111 	KOBJMETHOD(g_part_name,		g_part_ebr_name),
112 	KOBJMETHOD(g_part_precheck,	g_part_ebr_precheck),
113 	KOBJMETHOD(g_part_probe,	g_part_ebr_probe),
114 	KOBJMETHOD(g_part_read,		g_part_ebr_read),
115 	KOBJMETHOD(g_part_resize,	g_part_ebr_resize),
116 	KOBJMETHOD(g_part_setunset,	g_part_ebr_setunset),
117 	KOBJMETHOD(g_part_type,		g_part_ebr_type),
118 	KOBJMETHOD(g_part_write,	g_part_ebr_write),
119 	{ 0, 0 }
120 };
121 
122 static struct g_part_scheme g_part_ebr_scheme = {
123 	"EBR",
124 	g_part_ebr_methods,
125 	sizeof(struct g_part_ebr_table),
126 	.gps_entrysz = sizeof(struct g_part_ebr_entry),
127 	.gps_minent = 1,
128 	.gps_maxent = INT_MAX,
129 };
130 G_PART_SCHEME_DECLARE(g_part_ebr);
131 MODULE_VERSION(geom_part_ebr, 0);
132 
133 static struct g_part_ebr_alias {
134 	u_char		typ;
135 	int		alias;
136 } ebr_alias_match[] = {
137 	{ DOSPTYP_386BSD,	G_PART_ALIAS_FREEBSD },
138 	{ DOSPTYP_NTFS,		G_PART_ALIAS_MS_NTFS },
139 	{ DOSPTYP_FAT32,	G_PART_ALIAS_MS_FAT32 },
140 	{ DOSPTYP_FAT32LBA,	G_PART_ALIAS_MS_FAT32LBA },
141 	{ DOSPTYP_LINSWP,	G_PART_ALIAS_LINUX_SWAP },
142 	{ DOSPTYP_LINUX,	G_PART_ALIAS_LINUX_DATA },
143 	{ DOSPTYP_LINLVM,	G_PART_ALIAS_LINUX_LVM },
144 	{ DOSPTYP_LINRAID,	G_PART_ALIAS_LINUX_RAID },
145 };
146 
147 static void ebr_set_chs(struct g_part_table *, uint32_t, u_char *, u_char *,
148     u_char *);
149 
150 static void
151 ebr_entry_decode(const char *p, struct dos_partition *ent)
152 {
153 	ent->dp_flag = p[0];
154 	ent->dp_shd = p[1];
155 	ent->dp_ssect = p[2];
156 	ent->dp_scyl = p[3];
157 	ent->dp_typ = p[4];
158 	ent->dp_ehd = p[5];
159 	ent->dp_esect = p[6];
160 	ent->dp_ecyl = p[7];
161 	ent->dp_start = le32dec(p + 8);
162 	ent->dp_size = le32dec(p + 12);
163 }
164 
165 static void
166 ebr_entry_link(struct g_part_table *table, uint32_t start, uint32_t end,
167    u_char *buf)
168 {
169 
170 	buf[0] = 0 /* dp_flag */;
171 	ebr_set_chs(table, start, &buf[3] /* dp_scyl */, &buf[1] /* dp_shd */,
172 	    &buf[2] /* dp_ssect */);
173 	buf[4] = 5 /* dp_typ */;
174 	ebr_set_chs(table, end, &buf[7] /* dp_ecyl */, &buf[5] /* dp_ehd */,
175 	    &buf[6] /* dp_esect */);
176 	le32enc(buf + 8, start);
177 	le32enc(buf + 12, end - start + 1);
178 }
179 
180 static int
181 ebr_parse_type(const char *type, u_char *dp_typ)
182 {
183 	const char *alias;
184 	char *endp;
185 	long lt;
186 	int i;
187 
188 	if (type[0] == '!') {
189 		lt = strtol(type + 1, &endp, 0);
190 		if (type[1] == '\0' || *endp != '\0' || lt <= 0 || lt >= 256)
191 			return (EINVAL);
192 		*dp_typ = (u_char)lt;
193 		return (0);
194 	}
195 	for (i = 0; i < nitems(ebr_alias_match); i++) {
196 		alias = g_part_alias_name(ebr_alias_match[i].alias);
197 		if (strcasecmp(type, alias) == 0) {
198 			*dp_typ = ebr_alias_match[i].typ;
199 			return (0);
200 		}
201 	}
202 	return (EINVAL);
203 }
204 
205 
206 static void
207 ebr_set_chs(struct g_part_table *table, uint32_t lba, u_char *cylp, u_char *hdp,
208     u_char *secp)
209 {
210 	uint32_t cyl, hd, sec;
211 
212 	sec = lba % table->gpt_sectors + 1;
213 	lba /= table->gpt_sectors;
214 	hd = lba % table->gpt_heads;
215 	lba /= table->gpt_heads;
216 	cyl = lba;
217 	if (cyl > 1023)
218 		sec = hd = cyl = ~0;
219 
220 	*cylp = cyl & 0xff;
221 	*hdp = hd & 0xff;
222 	*secp = (sec & 0x3f) | ((cyl >> 2) & 0xc0);
223 }
224 
225 static int
226 ebr_align(struct g_part_table *basetable, uint32_t *start, uint32_t *size)
227 {
228 	uint32_t sectors;
229 
230 	sectors = basetable->gpt_sectors;
231 	if (*size < 2 * sectors)
232 		return (EINVAL);
233 	if (*start % sectors) {
234 		*size += (*start % sectors) - sectors;
235 		*start -= (*start % sectors) - sectors;
236 	}
237 	if (*size % sectors)
238 		*size -= (*size % sectors);
239 	if (*size < 2 * sectors)
240 		return (EINVAL);
241 	return (0);
242 }
243 
244 
245 static int
246 g_part_ebr_add(struct g_part_table *basetable, struct g_part_entry *baseentry,
247     struct g_part_parms *gpp)
248 {
249 	struct g_provider *pp;
250 	struct g_part_ebr_entry *entry;
251 	uint32_t start, size;
252 
253 	if (gpp->gpp_parms & G_PART_PARM_LABEL)
254 		return (EINVAL);
255 
256 	pp = LIST_FIRST(&basetable->gpt_gp->consumer)->provider;
257 	entry = (struct g_part_ebr_entry *)baseentry;
258 	start = gpp->gpp_start;
259 	size = gpp->gpp_size;
260 	if (ebr_align(basetable, &start, &size) != 0)
261 		return (EINVAL);
262 	if (baseentry->gpe_deleted)
263 		bzero(&entry->ent, sizeof(entry->ent));
264 
265 	KASSERT(baseentry->gpe_start <= start, ("%s", __func__));
266 	KASSERT(baseentry->gpe_end >= start + size - 1, ("%s", __func__));
267 	baseentry->gpe_index = (start / basetable->gpt_sectors) + 1;
268 	baseentry->gpe_offset =
269 	    (off_t)(start + basetable->gpt_sectors) * pp->sectorsize;
270 	baseentry->gpe_start = start;
271 	baseentry->gpe_end = start + size - 1;
272 	entry->ent.dp_start = basetable->gpt_sectors;
273 	entry->ent.dp_size = size - basetable->gpt_sectors;
274 	ebr_set_chs(basetable, entry->ent.dp_start, &entry->ent.dp_scyl,
275 	    &entry->ent.dp_shd, &entry->ent.dp_ssect);
276 	ebr_set_chs(basetable, baseentry->gpe_end, &entry->ent.dp_ecyl,
277 	    &entry->ent.dp_ehd, &entry->ent.dp_esect);
278 	return (ebr_parse_type(gpp->gpp_type, &entry->ent.dp_typ));
279 }
280 
281 static int
282 g_part_ebr_create(struct g_part_table *basetable, struct g_part_parms *gpp)
283 {
284 	char type[64];
285 	struct g_consumer *cp;
286 	struct g_provider *pp;
287 	uint32_t msize;
288 	int error;
289 
290 	pp = gpp->gpp_provider;
291 
292 	if (pp->sectorsize < EBRSIZE)
293 		return (ENOSPC);
294 	if (pp->sectorsize > 4096)
295 		return (ENXIO);
296 
297 	/* Check that we have a parent and that it's a MBR. */
298 	if (basetable->gpt_depth == 0)
299 		return (ENXIO);
300 	cp = LIST_FIRST(&pp->consumers);
301 	error = g_getattr("PART::scheme", cp, &type);
302 	if (error != 0)
303 		return (error);
304 	if (strcmp(type, "MBR") != 0)
305 		return (ENXIO);
306 	error = g_getattr("PART::type", cp, &type);
307 	if (error != 0)
308 		return (error);
309 	if (strcmp(type, "ebr") != 0)
310 		return (ENXIO);
311 
312 	msize = MIN(pp->mediasize / pp->sectorsize, UINT32_MAX);
313 	basetable->gpt_first = 0;
314 	basetable->gpt_last = msize - 1;
315 	basetable->gpt_entries = msize / basetable->gpt_sectors;
316 	return (0);
317 }
318 
319 static int
320 g_part_ebr_destroy(struct g_part_table *basetable, struct g_part_parms *gpp)
321 {
322 
323 	/* Wipe the first sector to clear the partitioning. */
324 	basetable->gpt_smhead |= 1;
325 	return (0);
326 }
327 
328 static void
329 g_part_ebr_dumpconf(struct g_part_table *table, struct g_part_entry *baseentry,
330     struct sbuf *sb, const char *indent)
331 {
332 	struct g_part_ebr_entry *entry;
333 
334 	entry = (struct g_part_ebr_entry *)baseentry;
335 	if (indent == NULL) {
336 		/* conftxt: libdisk compatibility */
337 		sbuf_printf(sb, " xs MBREXT xt %u", entry->ent.dp_typ);
338 	} else if (entry != NULL) {
339 		/* confxml: partition entry information */
340 		sbuf_printf(sb, "%s<rawtype>%u</rawtype>\n", indent,
341 		    entry->ent.dp_typ);
342 		if (entry->ent.dp_flag & 0x80)
343 			sbuf_printf(sb, "%s<attrib>active</attrib>\n", indent);
344 	} else {
345 		/* confxml: scheme information */
346 	}
347 }
348 
349 static int
350 g_part_ebr_dumpto(struct g_part_table *table, struct g_part_entry *baseentry)
351 {
352 	struct g_part_ebr_entry *entry;
353 
354 	/* Allow dumping to a FreeBSD partition or Linux swap partition only. */
355 	entry = (struct g_part_ebr_entry *)baseentry;
356 	return ((entry->ent.dp_typ == DOSPTYP_386BSD ||
357 	    entry->ent.dp_typ == DOSPTYP_LINSWP) ? 1 : 0);
358 }
359 
360 #if defined(GEOM_PART_EBR_COMPAT)
361 static void
362 g_part_ebr_fullname(struct g_part_table *table, struct g_part_entry *entry,
363     struct sbuf *sb, const char *pfx)
364 {
365 	struct g_part_entry *iter;
366 	u_int idx;
367 
368 	idx = 5;
369 	LIST_FOREACH(iter, &table->gpt_entry, gpe_entry) {
370 		if (iter == entry)
371 			break;
372 		idx++;
373 	}
374 	sbuf_printf(sb, "%.*s%u", (int)strlen(pfx) - 1, pfx, idx);
375 }
376 #endif
377 
378 static int
379 g_part_ebr_modify(struct g_part_table *basetable,
380     struct g_part_entry *baseentry, struct g_part_parms *gpp)
381 {
382 	struct g_part_ebr_entry *entry;
383 
384 	if (gpp->gpp_parms & G_PART_PARM_LABEL)
385 		return (EINVAL);
386 
387 	entry = (struct g_part_ebr_entry *)baseentry;
388 	if (gpp->gpp_parms & G_PART_PARM_TYPE)
389 		return (ebr_parse_type(gpp->gpp_type, &entry->ent.dp_typ));
390 	return (0);
391 }
392 
393 static int
394 g_part_ebr_resize(struct g_part_table *basetable,
395     struct g_part_entry *baseentry, struct g_part_parms *gpp)
396 {
397 	struct g_provider *pp;
398 
399 	if (baseentry != NULL)
400 		return (EOPNOTSUPP);
401 	pp = LIST_FIRST(&basetable->gpt_gp->consumer)->provider;
402 	basetable->gpt_last = MIN(pp->mediasize / pp->sectorsize,
403 	    UINT32_MAX) - 1;
404 	return (0);
405 }
406 
407 static const char *
408 g_part_ebr_name(struct g_part_table *table, struct g_part_entry *entry,
409     char *buf, size_t bufsz)
410 {
411 
412 	snprintf(buf, bufsz, "+%08u", entry->gpe_index);
413 	return (buf);
414 }
415 
416 static int
417 g_part_ebr_precheck(struct g_part_table *table, enum g_part_ctl req,
418     struct g_part_parms *gpp)
419 {
420 #if defined(GEOM_PART_EBR_COMPAT)
421 	if (req == G_PART_CTL_DESTROY)
422 		return (0);
423 	return (ECANCELED);
424 #else
425 	/*
426 	 * The index is a function of the start of the partition.
427 	 * This is not something the user can override, nor is it
428 	 * something the common code will do right. We can set the
429 	 * index now so that we get what we need.
430 	 */
431 	if (req == G_PART_CTL_ADD)
432 		gpp->gpp_index = (gpp->gpp_start / table->gpt_sectors) + 1;
433 	return (0);
434 #endif
435 }
436 
437 static int
438 g_part_ebr_probe(struct g_part_table *table, struct g_consumer *cp)
439 {
440 	char type[64];
441 	struct g_provider *pp;
442 	u_char *buf, *p;
443 	int error, index, res;
444 	uint16_t magic;
445 
446 	pp = cp->provider;
447 
448 	/* Sanity-check the provider. */
449 	if (pp->sectorsize < EBRSIZE || pp->mediasize < pp->sectorsize)
450 		return (ENOSPC);
451 	if (pp->sectorsize > 4096)
452 		return (ENXIO);
453 
454 	/* Check that we have a parent and that it's a MBR. */
455 	if (table->gpt_depth == 0)
456 		return (ENXIO);
457 	error = g_getattr("PART::scheme", cp, &type);
458 	if (error != 0)
459 		return (error);
460 	if (strcmp(type, "MBR") != 0)
461 		return (ENXIO);
462 	/* Check that partition has type DOSPTYP_EBR. */
463 	error = g_getattr("PART::type", cp, &type);
464 	if (error != 0)
465 		return (error);
466 	if (strcmp(type, "ebr") != 0)
467 		return (ENXIO);
468 
469 	/* Check that there's a EBR. */
470 	buf = g_read_data(cp, 0L, pp->sectorsize, &error);
471 	if (buf == NULL)
472 		return (error);
473 
474 	/* We goto out on mismatch. */
475 	res = ENXIO;
476 
477 	magic = le16dec(buf + DOSMAGICOFFSET);
478 	if (magic != DOSMAGIC)
479 		goto out;
480 
481 	for (index = 0; index < 2; index++) {
482 		p = buf + DOSPARTOFF + index * DOSPARTSIZE;
483 		if (p[0] != 0 && p[0] != 0x80)
484 			goto out;
485 	}
486 	res = G_PART_PROBE_PRI_NORM;
487 
488  out:
489 	g_free(buf);
490 	return (res);
491 }
492 
493 static int
494 g_part_ebr_read(struct g_part_table *basetable, struct g_consumer *cp)
495 {
496 	struct dos_partition ent[2];
497 	struct g_provider *pp;
498 	struct g_part_entry *baseentry;
499 	struct g_part_ebr_table *table;
500 	struct g_part_ebr_entry *entry;
501 	u_char *buf;
502 	off_t ofs, msize;
503 	u_int lba;
504 	int error, index;
505 
506 	pp = cp->provider;
507 	table = (struct g_part_ebr_table *)basetable;
508 	msize = MIN(pp->mediasize / pp->sectorsize, UINT32_MAX);
509 
510 	lba = 0;
511 	while (1) {
512 		ofs = (off_t)lba * pp->sectorsize;
513 		buf = g_read_data(cp, ofs, pp->sectorsize, &error);
514 		if (buf == NULL)
515 			return (error);
516 
517 		ebr_entry_decode(buf + DOSPARTOFF + 0 * DOSPARTSIZE, ent + 0);
518 		ebr_entry_decode(buf + DOSPARTOFF + 1 * DOSPARTSIZE, ent + 1);
519 
520 		/* The 3rd & 4th entries should be zeroes. */
521 		if (le64dec(buf + DOSPARTOFF + 2 * DOSPARTSIZE) +
522 		    le64dec(buf + DOSPARTOFF + 3 * DOSPARTSIZE) != 0) {
523 			basetable->gpt_corrupt = 1;
524 			printf("GEOM: %s: invalid entries in the EBR ignored.\n",
525 			    pp->name);
526 		}
527 #ifndef GEOM_PART_EBR_COMPAT
528 		/* Save the first EBR, it can contain a boot code */
529 		if (lba == 0)
530 			bcopy(buf, table->ebr, sizeof(table->ebr));
531 #endif
532 		g_free(buf);
533 
534 		if (ent[0].dp_typ == 0)
535 			break;
536 
537 		if (ent[0].dp_typ == 5 && ent[1].dp_typ == 0) {
538 			lba = ent[0].dp_start;
539 			continue;
540 		}
541 
542 		index = (lba / basetable->gpt_sectors) + 1;
543 		baseentry = (struct g_part_entry *)g_part_new_entry(basetable,
544 		    index, lba, lba + ent[0].dp_start + ent[0].dp_size - 1);
545 		baseentry->gpe_offset = (off_t)(lba + ent[0].dp_start) *
546 		    pp->sectorsize;
547 		entry = (struct g_part_ebr_entry *)baseentry;
548 		entry->ent = ent[0];
549 
550 		if (ent[1].dp_typ == 0)
551 			break;
552 
553 		lba = ent[1].dp_start;
554 	}
555 
556 	basetable->gpt_entries = msize / basetable->gpt_sectors;
557 	basetable->gpt_first = 0;
558 	basetable->gpt_last = msize - 1;
559 	return (0);
560 }
561 
562 static int
563 g_part_ebr_setunset(struct g_part_table *table, struct g_part_entry *baseentry,
564     const char *attrib, unsigned int set)
565 {
566 	struct g_part_entry *iter;
567 	struct g_part_ebr_entry *entry;
568 	int changed;
569 
570 	if (baseentry == NULL)
571 		return (ENODEV);
572 	if (strcasecmp(attrib, "active") != 0)
573 		return (EINVAL);
574 
575 	/* Only one entry can have the active attribute. */
576 	LIST_FOREACH(iter, &table->gpt_entry, gpe_entry) {
577 		if (iter->gpe_deleted)
578 			continue;
579 		changed = 0;
580 		entry = (struct g_part_ebr_entry *)iter;
581 		if (iter == baseentry) {
582 			if (set && (entry->ent.dp_flag & 0x80) == 0) {
583 				entry->ent.dp_flag |= 0x80;
584 				changed = 1;
585 			} else if (!set && (entry->ent.dp_flag & 0x80)) {
586 				entry->ent.dp_flag &= ~0x80;
587 				changed = 1;
588 			}
589 		} else {
590 			if (set && (entry->ent.dp_flag & 0x80)) {
591 				entry->ent.dp_flag &= ~0x80;
592 				changed = 1;
593 			}
594 		}
595 		if (changed && !iter->gpe_created)
596 			iter->gpe_modified = 1;
597 	}
598 	return (0);
599 }
600 
601 static const char *
602 g_part_ebr_type(struct g_part_table *basetable, struct g_part_entry *baseentry,
603     char *buf, size_t bufsz)
604 {
605 	struct g_part_ebr_entry *entry;
606 	int i;
607 
608 	entry = (struct g_part_ebr_entry *)baseentry;
609 	for (i = 0; i < nitems(ebr_alias_match); i++) {
610 		if (ebr_alias_match[i].typ == entry->ent.dp_typ)
611 			return (g_part_alias_name(ebr_alias_match[i].alias));
612 	}
613 	snprintf(buf, bufsz, "!%d", entry->ent.dp_typ);
614 	return (buf);
615 }
616 
617 static int
618 g_part_ebr_write(struct g_part_table *basetable, struct g_consumer *cp)
619 {
620 #ifndef GEOM_PART_EBR_COMPAT
621 	struct g_part_ebr_table *table;
622 #endif
623 	struct g_provider *pp;
624 	struct g_part_entry *baseentry, *next;
625 	struct g_part_ebr_entry *entry;
626 	u_char *buf;
627 	u_char *p;
628 	int error;
629 
630 	pp = cp->provider;
631 	buf = g_malloc(pp->sectorsize, M_WAITOK | M_ZERO);
632 #ifndef GEOM_PART_EBR_COMPAT
633 	table = (struct g_part_ebr_table *)basetable;
634 	bcopy(table->ebr, buf, DOSPARTOFF);
635 #endif
636 	le16enc(buf + DOSMAGICOFFSET, DOSMAGIC);
637 
638 	baseentry = LIST_FIRST(&basetable->gpt_entry);
639 	while (baseentry != NULL && baseentry->gpe_deleted)
640 		baseentry = LIST_NEXT(baseentry, gpe_entry);
641 
642 	/* Wipe-out the first EBR when there are no slices. */
643 	if (baseentry == NULL) {
644 		error = g_write_data(cp, 0, buf, pp->sectorsize);
645 		goto out;
646 	}
647 
648 	/*
649 	 * If the first partition is not in LBA 0, we need to
650 	 * put a "link" EBR in LBA 0.
651 	 */
652 	if (baseentry->gpe_start != 0) {
653 		ebr_entry_link(basetable, (uint32_t)baseentry->gpe_start,
654 		    (uint32_t)baseentry->gpe_end, buf + DOSPARTOFF);
655 		error = g_write_data(cp, 0, buf, pp->sectorsize);
656 		if (error)
657 			goto out;
658 	}
659 
660 	do {
661 		entry = (struct g_part_ebr_entry *)baseentry;
662 
663 		p = buf + DOSPARTOFF;
664 		p[0] = entry->ent.dp_flag;
665 		p[1] = entry->ent.dp_shd;
666 		p[2] = entry->ent.dp_ssect;
667 		p[3] = entry->ent.dp_scyl;
668 		p[4] = entry->ent.dp_typ;
669 		p[5] = entry->ent.dp_ehd;
670 		p[6] = entry->ent.dp_esect;
671 		p[7] = entry->ent.dp_ecyl;
672 		le32enc(p + 8, entry->ent.dp_start);
673 		le32enc(p + 12, entry->ent.dp_size);
674 
675 		next = LIST_NEXT(baseentry, gpe_entry);
676 		while (next != NULL && next->gpe_deleted)
677 			next = LIST_NEXT(next, gpe_entry);
678 
679 		p += DOSPARTSIZE;
680 		if (next != NULL)
681 			ebr_entry_link(basetable, (uint32_t)next->gpe_start,
682 			    (uint32_t)next->gpe_end, p);
683 		else
684 			bzero(p, DOSPARTSIZE);
685 
686 		error = g_write_data(cp, baseentry->gpe_start * pp->sectorsize,
687 		    buf, pp->sectorsize);
688 #ifndef GEOM_PART_EBR_COMPAT
689 		if (baseentry->gpe_start == 0)
690 			bzero(buf, DOSPARTOFF);
691 #endif
692 		baseentry = next;
693 	} while (!error && baseentry != NULL);
694 
695  out:
696 	g_free(buf);
697 	return (error);
698 }
699