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
53FEATURE(geom_part_ebr,
54    "GEOM partitioning class for extended boot records support");
55#if defined(GEOM_PART_EBR_COMPAT)
56FEATURE(geom_part_ebr_compat,
57    "GEOM EBR partitioning class: backward-compatible partition names");
58#endif
59
60#define	EBRSIZE		512
61
62struct 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
69struct g_part_ebr_entry {
70	struct g_part_entry	base;
71	struct dos_partition	ent;
72};
73
74static int g_part_ebr_add(struct g_part_table *, struct g_part_entry *,
75    struct g_part_parms *);
76static int g_part_ebr_create(struct g_part_table *, struct g_part_parms *);
77static int g_part_ebr_destroy(struct g_part_table *, struct g_part_parms *);
78static void g_part_ebr_dumpconf(struct g_part_table *, struct g_part_entry *,
79    struct sbuf *, const char *);
80static int g_part_ebr_dumpto(struct g_part_table *, struct g_part_entry *);
81#if defined(GEOM_PART_EBR_COMPAT)
82static void g_part_ebr_fullname(struct g_part_table *, struct g_part_entry *,
83    struct sbuf *, const char *);
84#endif
85static int g_part_ebr_modify(struct g_part_table *, struct g_part_entry *,
86    struct g_part_parms *);
87static const char *g_part_ebr_name(struct g_part_table *, struct g_part_entry *,
88    char *, size_t);
89static int g_part_ebr_precheck(struct g_part_table *, enum g_part_ctl,
90    struct g_part_parms *);
91static int g_part_ebr_probe(struct g_part_table *, struct g_consumer *);
92static int g_part_ebr_read(struct g_part_table *, struct g_consumer *);
93static int g_part_ebr_setunset(struct g_part_table *, struct g_part_entry *,
94    const char *, unsigned int);
95static const char *g_part_ebr_type(struct g_part_table *, struct g_part_entry *,
96    char *, size_t);
97static int g_part_ebr_write(struct g_part_table *, struct g_consumer *);
98static int g_part_ebr_resize(struct g_part_table *, struct g_part_entry *,
99    struct g_part_parms *);
100
101static 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
122static 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};
130G_PART_SCHEME_DECLARE(g_part_ebr);
131MODULE_VERSION(geom_part_ebr, 0);
132
133static 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_EFI,		G_PART_ALIAS_EFI },
139	{ DOSPTYP_FAT32,	G_PART_ALIAS_MS_FAT32 },
140	{ DOSPTYP_FAT32LBA,	G_PART_ALIAS_MS_FAT32LBA },
141	{ DOSPTYP_LINLVM,	G_PART_ALIAS_LINUX_LVM },
142	{ DOSPTYP_LINRAID,	G_PART_ALIAS_LINUX_RAID },
143	{ DOSPTYP_LINSWP,	G_PART_ALIAS_LINUX_SWAP },
144	{ DOSPTYP_LINUX,	G_PART_ALIAS_LINUX_DATA },
145	{ DOSPTYP_NTFS,		G_PART_ALIAS_MS_NTFS },
146};
147
148static void ebr_set_chs(struct g_part_table *, uint32_t, u_char *, u_char *,
149    u_char *);
150
151static void
152ebr_entry_decode(const char *p, struct dos_partition *ent)
153{
154	ent->dp_flag = p[0];
155	ent->dp_shd = p[1];
156	ent->dp_ssect = p[2];
157	ent->dp_scyl = p[3];
158	ent->dp_typ = p[4];
159	ent->dp_ehd = p[5];
160	ent->dp_esect = p[6];
161	ent->dp_ecyl = p[7];
162	ent->dp_start = le32dec(p + 8);
163	ent->dp_size = le32dec(p + 12);
164}
165
166static void
167ebr_entry_link(struct g_part_table *table, uint32_t start, uint32_t end,
168   u_char *buf)
169{
170
171	buf[0] = 0 /* dp_flag */;
172	ebr_set_chs(table, start, &buf[3] /* dp_scyl */, &buf[1] /* dp_shd */,
173	    &buf[2] /* dp_ssect */);
174	buf[4] = 5 /* dp_typ */;
175	ebr_set_chs(table, end, &buf[7] /* dp_ecyl */, &buf[5] /* dp_ehd */,
176	    &buf[6] /* dp_esect */);
177	le32enc(buf + 8, start);
178	le32enc(buf + 12, end - start + 1);
179}
180
181static int
182ebr_parse_type(const char *type, u_char *dp_typ)
183{
184	const char *alias;
185	char *endp;
186	long lt;
187	int i;
188
189	if (type[0] == '!') {
190		lt = strtol(type + 1, &endp, 0);
191		if (type[1] == '\0' || *endp != '\0' || lt <= 0 || lt >= 256)
192			return (EINVAL);
193		*dp_typ = (u_char)lt;
194		return (0);
195	}
196	for (i = 0; i < nitems(ebr_alias_match); i++) {
197		alias = g_part_alias_name(ebr_alias_match[i].alias);
198		if (strcasecmp(type, alias) == 0) {
199			*dp_typ = ebr_alias_match[i].typ;
200			return (0);
201		}
202	}
203	return (EINVAL);
204}
205
206
207static void
208ebr_set_chs(struct g_part_table *table, uint32_t lba, u_char *cylp, u_char *hdp,
209    u_char *secp)
210{
211	uint32_t cyl, hd, sec;
212
213	sec = lba % table->gpt_sectors + 1;
214	lba /= table->gpt_sectors;
215	hd = lba % table->gpt_heads;
216	lba /= table->gpt_heads;
217	cyl = lba;
218	if (cyl > 1023)
219		sec = hd = cyl = ~0;
220
221	*cylp = cyl & 0xff;
222	*hdp = hd & 0xff;
223	*secp = (sec & 0x3f) | ((cyl >> 2) & 0xc0);
224}
225
226static int
227ebr_align(struct g_part_table *basetable, uint32_t *start, uint32_t *size)
228{
229	uint32_t sectors;
230
231	sectors = basetable->gpt_sectors;
232	if (*size < 2 * sectors)
233		return (EINVAL);
234	if (*start % sectors) {
235		*size += (*start % sectors) - sectors;
236		*start -= (*start % sectors) - sectors;
237	}
238	if (*size % sectors)
239		*size -= (*size % sectors);
240	if (*size < 2 * sectors)
241		return (EINVAL);
242	return (0);
243}
244
245
246static int
247g_part_ebr_add(struct g_part_table *basetable, struct g_part_entry *baseentry,
248    struct g_part_parms *gpp)
249{
250	struct g_provider *pp;
251	struct g_part_ebr_entry *entry;
252	uint32_t start, size;
253
254	if (gpp->gpp_parms & G_PART_PARM_LABEL)
255		return (EINVAL);
256
257	pp = LIST_FIRST(&basetable->gpt_gp->consumer)->provider;
258	entry = (struct g_part_ebr_entry *)baseentry;
259	start = gpp->gpp_start;
260	size = gpp->gpp_size;
261	if (ebr_align(basetable, &start, &size) != 0)
262		return (EINVAL);
263	if (baseentry->gpe_deleted)
264		bzero(&entry->ent, sizeof(entry->ent));
265
266	KASSERT(baseentry->gpe_start <= start, ("%s", __func__));
267	KASSERT(baseentry->gpe_end >= start + size - 1, ("%s", __func__));
268	baseentry->gpe_index = (start / basetable->gpt_sectors) + 1;
269	baseentry->gpe_offset =
270	    (off_t)(start + basetable->gpt_sectors) * pp->sectorsize;
271	baseentry->gpe_start = start;
272	baseentry->gpe_end = start + size - 1;
273	entry->ent.dp_start = basetable->gpt_sectors;
274	entry->ent.dp_size = size - basetable->gpt_sectors;
275	ebr_set_chs(basetable, entry->ent.dp_start, &entry->ent.dp_scyl,
276	    &entry->ent.dp_shd, &entry->ent.dp_ssect);
277	ebr_set_chs(basetable, baseentry->gpe_end, &entry->ent.dp_ecyl,
278	    &entry->ent.dp_ehd, &entry->ent.dp_esect);
279	return (ebr_parse_type(gpp->gpp_type, &entry->ent.dp_typ));
280}
281
282static int
283g_part_ebr_create(struct g_part_table *basetable, struct g_part_parms *gpp)
284{
285	char type[64];
286	struct g_consumer *cp;
287	struct g_provider *pp;
288	uint32_t msize;
289	int error;
290
291	pp = gpp->gpp_provider;
292
293	if (pp->sectorsize < EBRSIZE)
294		return (ENOSPC);
295	if (pp->sectorsize > 4096)
296		return (ENXIO);
297
298	/* Check that we have a parent and that it's a MBR. */
299	if (basetable->gpt_depth == 0)
300		return (ENXIO);
301	cp = LIST_FIRST(&pp->consumers);
302	error = g_getattr("PART::scheme", cp, &type);
303	if (error != 0)
304		return (error);
305	if (strcmp(type, "MBR") != 0)
306		return (ENXIO);
307	error = g_getattr("PART::type", cp, &type);
308	if (error != 0)
309		return (error);
310	if (strcmp(type, "ebr") != 0)
311		return (ENXIO);
312
313	msize = MIN(pp->mediasize / pp->sectorsize, UINT32_MAX);
314	basetable->gpt_first = 0;
315	basetable->gpt_last = msize - 1;
316	basetable->gpt_entries = msize / basetable->gpt_sectors;
317	return (0);
318}
319
320static int
321g_part_ebr_destroy(struct g_part_table *basetable, struct g_part_parms *gpp)
322{
323
324	/* Wipe the first sector to clear the partitioning. */
325	basetable->gpt_smhead |= 1;
326	return (0);
327}
328
329static void
330g_part_ebr_dumpconf(struct g_part_table *table, struct g_part_entry *baseentry,
331    struct sbuf *sb, const char *indent)
332{
333	struct g_part_ebr_entry *entry;
334
335	entry = (struct g_part_ebr_entry *)baseentry;
336	if (indent == NULL) {
337		/* conftxt: libdisk compatibility */
338		sbuf_printf(sb, " xs MBREXT xt %u", entry->ent.dp_typ);
339	} else if (entry != NULL) {
340		/* confxml: partition entry information */
341		sbuf_printf(sb, "%s<rawtype>%u</rawtype>\n", indent,
342		    entry->ent.dp_typ);
343		if (entry->ent.dp_flag & 0x80)
344			sbuf_printf(sb, "%s<attrib>active</attrib>\n", indent);
345	} else {
346		/* confxml: scheme information */
347	}
348}
349
350static int
351g_part_ebr_dumpto(struct g_part_table *table, struct g_part_entry *baseentry)
352{
353	struct g_part_ebr_entry *entry;
354
355	/* Allow dumping to a FreeBSD partition or Linux swap partition only. */
356	entry = (struct g_part_ebr_entry *)baseentry;
357	return ((entry->ent.dp_typ == DOSPTYP_386BSD ||
358	    entry->ent.dp_typ == DOSPTYP_LINSWP) ? 1 : 0);
359}
360
361#if defined(GEOM_PART_EBR_COMPAT)
362static void
363g_part_ebr_fullname(struct g_part_table *table, struct g_part_entry *entry,
364    struct sbuf *sb, const char *pfx)
365{
366	struct g_part_entry *iter;
367	u_int idx;
368
369	idx = 5;
370	LIST_FOREACH(iter, &table->gpt_entry, gpe_entry) {
371		if (iter == entry)
372			break;
373		idx++;
374	}
375	sbuf_printf(sb, "%.*s%u", (int)strlen(pfx) - 1, pfx, idx);
376}
377#endif
378
379static int
380g_part_ebr_modify(struct g_part_table *basetable,
381    struct g_part_entry *baseentry, struct g_part_parms *gpp)
382{
383	struct g_part_ebr_entry *entry;
384
385	if (gpp->gpp_parms & G_PART_PARM_LABEL)
386		return (EINVAL);
387
388	entry = (struct g_part_ebr_entry *)baseentry;
389	if (gpp->gpp_parms & G_PART_PARM_TYPE)
390		return (ebr_parse_type(gpp->gpp_type, &entry->ent.dp_typ));
391	return (0);
392}
393
394static int
395g_part_ebr_resize(struct g_part_table *basetable,
396    struct g_part_entry *baseentry, struct g_part_parms *gpp)
397{
398	struct g_provider *pp;
399
400	if (baseentry != NULL)
401		return (EOPNOTSUPP);
402	pp = LIST_FIRST(&basetable->gpt_gp->consumer)->provider;
403	basetable->gpt_last = MIN(pp->mediasize / pp->sectorsize,
404	    UINT32_MAX) - 1;
405	return (0);
406}
407
408static const char *
409g_part_ebr_name(struct g_part_table *table, struct g_part_entry *entry,
410    char *buf, size_t bufsz)
411{
412
413	snprintf(buf, bufsz, "+%08u", entry->gpe_index);
414	return (buf);
415}
416
417static int
418g_part_ebr_precheck(struct g_part_table *table, enum g_part_ctl req,
419    struct g_part_parms *gpp)
420{
421#if defined(GEOM_PART_EBR_COMPAT)
422	if (req == G_PART_CTL_DESTROY)
423		return (0);
424	return (ECANCELED);
425#else
426	/*
427	 * The index is a function of the start of the partition.
428	 * This is not something the user can override, nor is it
429	 * something the common code will do right. We can set the
430	 * index now so that we get what we need.
431	 */
432	if (req == G_PART_CTL_ADD)
433		gpp->gpp_index = (gpp->gpp_start / table->gpt_sectors) + 1;
434	return (0);
435#endif
436}
437
438static int
439g_part_ebr_probe(struct g_part_table *table, struct g_consumer *cp)
440{
441	char type[64];
442	struct g_provider *pp;
443	u_char *buf, *p;
444	int error, index, res;
445	uint16_t magic;
446
447	pp = cp->provider;
448
449	/* Sanity-check the provider. */
450	if (pp->sectorsize < EBRSIZE || pp->mediasize < pp->sectorsize)
451		return (ENOSPC);
452	if (pp->sectorsize > 4096)
453		return (ENXIO);
454
455	/* Check that we have a parent and that it's a MBR. */
456	if (table->gpt_depth == 0)
457		return (ENXIO);
458	error = g_getattr("PART::scheme", cp, &type);
459	if (error != 0)
460		return (error);
461	if (strcmp(type, "MBR") != 0)
462		return (ENXIO);
463	/* Check that partition has type DOSPTYP_EBR. */
464	error = g_getattr("PART::type", cp, &type);
465	if (error != 0)
466		return (error);
467	if (strcmp(type, "ebr") != 0)
468		return (ENXIO);
469
470	/* Check that there's a EBR. */
471	buf = g_read_data(cp, 0L, pp->sectorsize, &error);
472	if (buf == NULL)
473		return (error);
474
475	/* We goto out on mismatch. */
476	res = ENXIO;
477
478	magic = le16dec(buf + DOSMAGICOFFSET);
479	if (magic != DOSMAGIC)
480		goto out;
481
482	for (index = 0; index < 2; index++) {
483		p = buf + DOSPARTOFF + index * DOSPARTSIZE;
484		if (p[0] != 0 && p[0] != 0x80)
485			goto out;
486	}
487	res = G_PART_PROBE_PRI_NORM;
488
489 out:
490	g_free(buf);
491	return (res);
492}
493
494static int
495g_part_ebr_read(struct g_part_table *basetable, struct g_consumer *cp)
496{
497	struct dos_partition ent[2];
498	struct g_provider *pp;
499	struct g_part_entry *baseentry;
500	struct g_part_ebr_table *table;
501	struct g_part_ebr_entry *entry;
502	u_char *buf;
503	off_t ofs, msize;
504	u_int lba;
505	int error, index;
506
507	pp = cp->provider;
508	table = (struct g_part_ebr_table *)basetable;
509	msize = MIN(pp->mediasize / pp->sectorsize, UINT32_MAX);
510
511	lba = 0;
512	while (1) {
513		ofs = (off_t)lba * pp->sectorsize;
514		buf = g_read_data(cp, ofs, pp->sectorsize, &error);
515		if (buf == NULL)
516			return (error);
517
518		ebr_entry_decode(buf + DOSPARTOFF + 0 * DOSPARTSIZE, ent + 0);
519		ebr_entry_decode(buf + DOSPARTOFF + 1 * DOSPARTSIZE, ent + 1);
520
521		/* The 3rd & 4th entries should be zeroes. */
522		if (le64dec(buf + DOSPARTOFF + 2 * DOSPARTSIZE) +
523		    le64dec(buf + DOSPARTOFF + 3 * DOSPARTSIZE) != 0) {
524			basetable->gpt_corrupt = 1;
525			printf("GEOM: %s: invalid entries in the EBR ignored.\n",
526			    pp->name);
527		}
528#ifndef GEOM_PART_EBR_COMPAT
529		/* Save the first EBR, it can contain a boot code */
530		if (lba == 0)
531			bcopy(buf, table->ebr, sizeof(table->ebr));
532#endif
533		g_free(buf);
534
535		if (ent[0].dp_typ == 0)
536			break;
537
538		if (ent[0].dp_typ == 5 && ent[1].dp_typ == 0) {
539			lba = ent[0].dp_start;
540			continue;
541		}
542
543		index = (lba / basetable->gpt_sectors) + 1;
544		baseentry = (struct g_part_entry *)g_part_new_entry(basetable,
545		    index, lba, lba + ent[0].dp_start + ent[0].dp_size - 1);
546		baseentry->gpe_offset = (off_t)(lba + ent[0].dp_start) *
547		    pp->sectorsize;
548		entry = (struct g_part_ebr_entry *)baseentry;
549		entry->ent = ent[0];
550
551		if (ent[1].dp_typ == 0)
552			break;
553
554		lba = ent[1].dp_start;
555	}
556
557	basetable->gpt_entries = msize / basetable->gpt_sectors;
558	basetable->gpt_first = 0;
559	basetable->gpt_last = msize - 1;
560	return (0);
561}
562
563static int
564g_part_ebr_setunset(struct g_part_table *table, struct g_part_entry *baseentry,
565    const char *attrib, unsigned int set)
566{
567	struct g_part_entry *iter;
568	struct g_part_ebr_entry *entry;
569	int changed;
570
571	if (baseentry == NULL)
572		return (ENODEV);
573	if (strcasecmp(attrib, "active") != 0)
574		return (EINVAL);
575
576	/* Only one entry can have the active attribute. */
577	LIST_FOREACH(iter, &table->gpt_entry, gpe_entry) {
578		if (iter->gpe_deleted)
579			continue;
580		changed = 0;
581		entry = (struct g_part_ebr_entry *)iter;
582		if (iter == baseentry) {
583			if (set && (entry->ent.dp_flag & 0x80) == 0) {
584				entry->ent.dp_flag |= 0x80;
585				changed = 1;
586			} else if (!set && (entry->ent.dp_flag & 0x80)) {
587				entry->ent.dp_flag &= ~0x80;
588				changed = 1;
589			}
590		} else {
591			if (set && (entry->ent.dp_flag & 0x80)) {
592				entry->ent.dp_flag &= ~0x80;
593				changed = 1;
594			}
595		}
596		if (changed && !iter->gpe_created)
597			iter->gpe_modified = 1;
598	}
599	return (0);
600}
601
602static const char *
603g_part_ebr_type(struct g_part_table *basetable, struct g_part_entry *baseentry,
604    char *buf, size_t bufsz)
605{
606	struct g_part_ebr_entry *entry;
607	int i;
608
609	entry = (struct g_part_ebr_entry *)baseentry;
610	for (i = 0; i < nitems(ebr_alias_match); i++) {
611		if (ebr_alias_match[i].typ == entry->ent.dp_typ)
612			return (g_part_alias_name(ebr_alias_match[i].alias));
613	}
614	snprintf(buf, bufsz, "!%d", entry->ent.dp_typ);
615	return (buf);
616}
617
618static int
619g_part_ebr_write(struct g_part_table *basetable, struct g_consumer *cp)
620{
621#ifndef GEOM_PART_EBR_COMPAT
622	struct g_part_ebr_table *table;
623#endif
624	struct g_provider *pp;
625	struct g_part_entry *baseentry, *next;
626	struct g_part_ebr_entry *entry;
627	u_char *buf;
628	u_char *p;
629	int error;
630
631	pp = cp->provider;
632	buf = g_malloc(pp->sectorsize, M_WAITOK | M_ZERO);
633#ifndef GEOM_PART_EBR_COMPAT
634	table = (struct g_part_ebr_table *)basetable;
635	bcopy(table->ebr, buf, DOSPARTOFF);
636#endif
637	le16enc(buf + DOSMAGICOFFSET, DOSMAGIC);
638
639	baseentry = LIST_FIRST(&basetable->gpt_entry);
640	while (baseentry != NULL && baseentry->gpe_deleted)
641		baseentry = LIST_NEXT(baseentry, gpe_entry);
642
643	/* Wipe-out the first EBR when there are no slices. */
644	if (baseentry == NULL) {
645		error = g_write_data(cp, 0, buf, pp->sectorsize);
646		goto out;
647	}
648
649	/*
650	 * If the first partition is not in LBA 0, we need to
651	 * put a "link" EBR in LBA 0.
652	 */
653	if (baseentry->gpe_start != 0) {
654		ebr_entry_link(basetable, (uint32_t)baseentry->gpe_start,
655		    (uint32_t)baseentry->gpe_end, buf + DOSPARTOFF);
656		error = g_write_data(cp, 0, buf, pp->sectorsize);
657		if (error)
658			goto out;
659	}
660
661	do {
662		entry = (struct g_part_ebr_entry *)baseentry;
663
664		p = buf + DOSPARTOFF;
665		p[0] = entry->ent.dp_flag;
666		p[1] = entry->ent.dp_shd;
667		p[2] = entry->ent.dp_ssect;
668		p[3] = entry->ent.dp_scyl;
669		p[4] = entry->ent.dp_typ;
670		p[5] = entry->ent.dp_ehd;
671		p[6] = entry->ent.dp_esect;
672		p[7] = entry->ent.dp_ecyl;
673		le32enc(p + 8, entry->ent.dp_start);
674		le32enc(p + 12, entry->ent.dp_size);
675
676		next = LIST_NEXT(baseentry, gpe_entry);
677		while (next != NULL && next->gpe_deleted)
678			next = LIST_NEXT(next, gpe_entry);
679
680		p += DOSPARTSIZE;
681		if (next != NULL)
682			ebr_entry_link(basetable, (uint32_t)next->gpe_start,
683			    (uint32_t)next->gpe_end, p);
684		else
685			bzero(p, DOSPARTSIZE);
686
687		error = g_write_data(cp, baseentry->gpe_start * pp->sectorsize,
688		    buf, pp->sectorsize);
689#ifndef GEOM_PART_EBR_COMPAT
690		if (baseentry->gpe_start == 0)
691			bzero(buf, DOSPARTOFF);
692#endif
693		baseentry = next;
694	} while (!error && baseentry != NULL);
695
696 out:
697	g_free(buf);
698	return (error);
699}
700