g_part_ebr.c revision 265910
1/*-
2 * Copyright (c) 2007-2009 Marcel Moolenaar
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 *
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27#include "opt_geom.h"
28
29#include <sys/cdefs.h>
30__FBSDID("$FreeBSD: stable/10/sys/geom/part/g_part_ebr.c 265910 2014-05-12 10:19:31Z ae $");
31
32#include <sys/param.h>
33#include <sys/bio.h>
34#include <sys/diskmbr.h>
35#include <sys/endian.h>
36#include <sys/kernel.h>
37#include <sys/kobj.h>
38#include <sys/limits.h>
39#include <sys/lock.h>
40#include <sys/malloc.h>
41#include <sys/mutex.h>
42#include <sys/queue.h>
43#include <sys/sbuf.h>
44#include <sys/systm.h>
45#include <sys/sysctl.h>
46#include <geom/geom.h>
47#include <geom/part/g_part.h>
48
49#include "g_part_if.h"
50
51FEATURE(geom_part_ebr,
52    "GEOM partitioning class for extended boot records support");
53#if defined(GEOM_PART_EBR_COMPAT)
54FEATURE(geom_part_ebr_compat,
55    "GEOM EBR partitioning class: backward-compatible partition names");
56#endif
57
58#define	EBRSIZE		512
59
60struct g_part_ebr_table {
61	struct g_part_table	base;
62#ifndef GEOM_PART_EBR_COMPAT
63	u_char		ebr[EBRSIZE];
64#endif
65};
66
67struct g_part_ebr_entry {
68	struct g_part_entry	base;
69	struct dos_partition	ent;
70};
71
72static int g_part_ebr_add(struct g_part_table *, struct g_part_entry *,
73    struct g_part_parms *);
74static int g_part_ebr_create(struct g_part_table *, struct g_part_parms *);
75static int g_part_ebr_destroy(struct g_part_table *, struct g_part_parms *);
76static void g_part_ebr_dumpconf(struct g_part_table *, struct g_part_entry *,
77    struct sbuf *, const char *);
78static int g_part_ebr_dumpto(struct g_part_table *, struct g_part_entry *);
79#if defined(GEOM_PART_EBR_COMPAT)
80static void g_part_ebr_fullname(struct g_part_table *, struct g_part_entry *,
81    struct sbuf *, const char *);
82#endif
83static int g_part_ebr_modify(struct g_part_table *, struct g_part_entry *,
84    struct g_part_parms *);
85static const char *g_part_ebr_name(struct g_part_table *, struct g_part_entry *,
86    char *, size_t);
87static int g_part_ebr_precheck(struct g_part_table *, enum g_part_ctl,
88    struct g_part_parms *);
89static int g_part_ebr_probe(struct g_part_table *, struct g_consumer *);
90static int g_part_ebr_read(struct g_part_table *, struct g_consumer *);
91static int g_part_ebr_setunset(struct g_part_table *, struct g_part_entry *,
92    const char *, unsigned int);
93static const char *g_part_ebr_type(struct g_part_table *, struct g_part_entry *,
94    char *, size_t);
95static int g_part_ebr_write(struct g_part_table *, struct g_consumer *);
96
97static kobj_method_t g_part_ebr_methods[] = {
98	KOBJMETHOD(g_part_add,		g_part_ebr_add),
99	KOBJMETHOD(g_part_create,	g_part_ebr_create),
100	KOBJMETHOD(g_part_destroy,	g_part_ebr_destroy),
101	KOBJMETHOD(g_part_dumpconf,	g_part_ebr_dumpconf),
102	KOBJMETHOD(g_part_dumpto,	g_part_ebr_dumpto),
103#if defined(GEOM_PART_EBR_COMPAT)
104	KOBJMETHOD(g_part_fullname,	g_part_ebr_fullname),
105#endif
106	KOBJMETHOD(g_part_modify,	g_part_ebr_modify),
107	KOBJMETHOD(g_part_name,		g_part_ebr_name),
108	KOBJMETHOD(g_part_precheck,	g_part_ebr_precheck),
109	KOBJMETHOD(g_part_probe,	g_part_ebr_probe),
110	KOBJMETHOD(g_part_read,		g_part_ebr_read),
111	KOBJMETHOD(g_part_setunset,	g_part_ebr_setunset),
112	KOBJMETHOD(g_part_type,		g_part_ebr_type),
113	KOBJMETHOD(g_part_write,	g_part_ebr_write),
114	{ 0, 0 }
115};
116
117static struct g_part_scheme g_part_ebr_scheme = {
118	"EBR",
119	g_part_ebr_methods,
120	sizeof(struct g_part_ebr_table),
121	.gps_entrysz = sizeof(struct g_part_ebr_entry),
122	.gps_minent = 1,
123	.gps_maxent = INT_MAX,
124};
125G_PART_SCHEME_DECLARE(g_part_ebr);
126
127static struct g_part_ebr_alias {
128	u_char		typ;
129	int		alias;
130} ebr_alias_match[] = {
131	{ DOSPTYP_386BSD,	G_PART_ALIAS_FREEBSD },
132	{ DOSPTYP_NTFS,		G_PART_ALIAS_MS_NTFS },
133	{ DOSPTYP_FAT32,	G_PART_ALIAS_MS_FAT32 },
134	{ DOSPTYP_LINSWP,	G_PART_ALIAS_LINUX_SWAP },
135	{ DOSPTYP_LINUX,	G_PART_ALIAS_LINUX_DATA },
136	{ DOSPTYP_LINLVM,	G_PART_ALIAS_LINUX_LVM },
137	{ DOSPTYP_LINRAID,	G_PART_ALIAS_LINUX_RAID },
138};
139
140static void ebr_set_chs(struct g_part_table *, uint32_t, u_char *, u_char *,
141    u_char *);
142
143static void
144ebr_entry_decode(const char *p, struct dos_partition *ent)
145{
146	ent->dp_flag = p[0];
147	ent->dp_shd = p[1];
148	ent->dp_ssect = p[2];
149	ent->dp_scyl = p[3];
150	ent->dp_typ = p[4];
151	ent->dp_ehd = p[5];
152	ent->dp_esect = p[6];
153	ent->dp_ecyl = p[7];
154	ent->dp_start = le32dec(p + 8);
155	ent->dp_size = le32dec(p + 12);
156}
157
158static void
159ebr_entry_link(struct g_part_table *table, uint32_t start, uint32_t end,
160   u_char *buf)
161{
162
163	buf[0] = 0 /* dp_flag */;
164	ebr_set_chs(table, start, &buf[3] /* dp_scyl */, &buf[1] /* dp_shd */,
165	    &buf[2] /* dp_ssect */);
166	buf[4] = 5 /* dp_typ */;
167	ebr_set_chs(table, end, &buf[7] /* dp_ecyl */, &buf[5] /* dp_ehd */,
168	    &buf[6] /* dp_esect */);
169	le32enc(buf + 8, start);
170	le32enc(buf + 12, end - start + 1);
171}
172
173static int
174ebr_parse_type(const char *type, u_char *dp_typ)
175{
176	const char *alias;
177	char *endp;
178	long lt;
179	int i;
180
181	if (type[0] == '!') {
182		lt = strtol(type + 1, &endp, 0);
183		if (type[1] == '\0' || *endp != '\0' || lt <= 0 || lt >= 256)
184			return (EINVAL);
185		*dp_typ = (u_char)lt;
186		return (0);
187	}
188	for (i = 0;
189	    i < sizeof(ebr_alias_match) / sizeof(ebr_alias_match[0]); i++) {
190		alias = g_part_alias_name(ebr_alias_match[i].alias);
191		if (strcasecmp(type, alias) == 0) {
192			*dp_typ = ebr_alias_match[i].typ;
193			return (0);
194		}
195	}
196	return (EINVAL);
197}
198
199
200static void
201ebr_set_chs(struct g_part_table *table, uint32_t lba, u_char *cylp, u_char *hdp,
202    u_char *secp)
203{
204	uint32_t cyl, hd, sec;
205
206	sec = lba % table->gpt_sectors + 1;
207	lba /= table->gpt_sectors;
208	hd = lba % table->gpt_heads;
209	lba /= table->gpt_heads;
210	cyl = lba;
211	if (cyl > 1023)
212		sec = hd = cyl = ~0;
213
214	*cylp = cyl & 0xff;
215	*hdp = hd & 0xff;
216	*secp = (sec & 0x3f) | ((cyl >> 2) & 0xc0);
217}
218
219static int
220ebr_align(struct g_part_table *basetable, uint32_t *start, uint32_t *size)
221{
222	uint32_t sectors;
223
224	sectors = basetable->gpt_sectors;
225	if (*size < 2 * sectors)
226		return (EINVAL);
227	if (*start % sectors) {
228		*size += (*start % sectors) - sectors;
229		*start -= (*start % sectors) - sectors;
230	}
231	if (*size % sectors)
232		*size -= (*size % sectors);
233	if (*size < 2 * sectors)
234		return (EINVAL);
235	return (0);
236}
237
238
239static int
240g_part_ebr_add(struct g_part_table *basetable, struct g_part_entry *baseentry,
241    struct g_part_parms *gpp)
242{
243	struct g_provider *pp;
244	struct g_part_ebr_entry *entry;
245	uint32_t start, size;
246
247	if (gpp->gpp_parms & G_PART_PARM_LABEL)
248		return (EINVAL);
249
250	pp = LIST_FIRST(&basetable->gpt_gp->consumer)->provider;
251	entry = (struct g_part_ebr_entry *)baseentry;
252	start = gpp->gpp_start;
253	size = gpp->gpp_size;
254	if (ebr_align(basetable, &start, &size) != 0)
255		return (EINVAL);
256	if (baseentry->gpe_deleted)
257		bzero(&entry->ent, sizeof(entry->ent));
258
259	KASSERT(baseentry->gpe_start <= start, ("%s", __func__));
260	KASSERT(baseentry->gpe_end >= start + size - 1, ("%s", __func__));
261	baseentry->gpe_index = (start / basetable->gpt_sectors) + 1;
262	baseentry->gpe_offset =
263	    (off_t)(start + basetable->gpt_sectors) * pp->sectorsize;
264	baseentry->gpe_start = start;
265	baseentry->gpe_end = start + size - 1;
266	entry->ent.dp_start = basetable->gpt_sectors;
267	entry->ent.dp_size = size - basetable->gpt_sectors;
268	ebr_set_chs(basetable, entry->ent.dp_start, &entry->ent.dp_scyl,
269	    &entry->ent.dp_shd, &entry->ent.dp_ssect);
270	ebr_set_chs(basetable, baseentry->gpe_end, &entry->ent.dp_ecyl,
271	    &entry->ent.dp_ehd, &entry->ent.dp_esect);
272	return (ebr_parse_type(gpp->gpp_type, &entry->ent.dp_typ));
273}
274
275static int
276g_part_ebr_create(struct g_part_table *basetable, struct g_part_parms *gpp)
277{
278	char type[64];
279	struct g_consumer *cp;
280	struct g_provider *pp;
281	uint32_t msize;
282	int error;
283
284	pp = gpp->gpp_provider;
285
286	if (pp->sectorsize < EBRSIZE)
287		return (ENOSPC);
288	if (pp->sectorsize > 4096)
289		return (ENXIO);
290
291	/* Check that we have a parent and that it's a MBR. */
292	if (basetable->gpt_depth == 0)
293		return (ENXIO);
294	cp = LIST_FIRST(&pp->consumers);
295	error = g_getattr("PART::scheme", cp, &type);
296	if (error != 0)
297		return (error);
298	if (strcmp(type, "MBR") != 0)
299		return (ENXIO);
300	error = g_getattr("PART::type", cp, &type);
301	if (error != 0)
302		return (error);
303	if (strcmp(type, "ebr") != 0)
304		return (ENXIO);
305
306	msize = MIN(pp->mediasize / pp->sectorsize, UINT32_MAX);
307	basetable->gpt_first = 0;
308	basetable->gpt_last = msize - 1;
309	basetable->gpt_entries = msize / basetable->gpt_sectors;
310	return (0);
311}
312
313static int
314g_part_ebr_destroy(struct g_part_table *basetable, struct g_part_parms *gpp)
315{
316
317	/* Wipe the first sector to clear the partitioning. */
318	basetable->gpt_smhead |= 1;
319	return (0);
320}
321
322static void
323g_part_ebr_dumpconf(struct g_part_table *table, struct g_part_entry *baseentry,
324    struct sbuf *sb, const char *indent)
325{
326	struct g_part_ebr_entry *entry;
327
328	entry = (struct g_part_ebr_entry *)baseentry;
329	if (indent == NULL) {
330		/* conftxt: libdisk compatibility */
331		sbuf_printf(sb, " xs MBREXT xt %u", entry->ent.dp_typ);
332	} else if (entry != NULL) {
333		/* confxml: partition entry information */
334		sbuf_printf(sb, "%s<rawtype>%u</rawtype>\n", indent,
335		    entry->ent.dp_typ);
336		if (entry->ent.dp_flag & 0x80)
337			sbuf_printf(sb, "%s<attrib>active</attrib>\n", indent);
338	} else {
339		/* confxml: scheme information */
340	}
341}
342
343static int
344g_part_ebr_dumpto(struct g_part_table *table, struct g_part_entry *baseentry)
345{
346	struct g_part_ebr_entry *entry;
347
348	/* Allow dumping to a FreeBSD partition or Linux swap partition only. */
349	entry = (struct g_part_ebr_entry *)baseentry;
350	return ((entry->ent.dp_typ == DOSPTYP_386BSD ||
351	    entry->ent.dp_typ == DOSPTYP_LINSWP) ? 1 : 0);
352}
353
354#if defined(GEOM_PART_EBR_COMPAT)
355static void
356g_part_ebr_fullname(struct g_part_table *table, struct g_part_entry *entry,
357    struct sbuf *sb, const char *pfx)
358{
359	struct g_part_entry *iter;
360	u_int idx;
361
362	idx = 5;
363	LIST_FOREACH(iter, &table->gpt_entry, gpe_entry) {
364		if (iter == entry)
365			break;
366		idx++;
367	}
368	sbuf_printf(sb, "%.*s%u", (int)strlen(pfx) - 1, pfx, idx);
369}
370#endif
371
372static int
373g_part_ebr_modify(struct g_part_table *basetable,
374    struct g_part_entry *baseentry, struct g_part_parms *gpp)
375{
376	struct g_part_ebr_entry *entry;
377
378	if (gpp->gpp_parms & G_PART_PARM_LABEL)
379		return (EINVAL);
380
381	entry = (struct g_part_ebr_entry *)baseentry;
382	if (gpp->gpp_parms & G_PART_PARM_TYPE)
383		return (ebr_parse_type(gpp->gpp_type, &entry->ent.dp_typ));
384	return (0);
385}
386
387static const char *
388g_part_ebr_name(struct g_part_table *table, struct g_part_entry *entry,
389    char *buf, size_t bufsz)
390{
391
392	snprintf(buf, bufsz, "+%08u", entry->gpe_index);
393	return (buf);
394}
395
396static int
397g_part_ebr_precheck(struct g_part_table *table, enum g_part_ctl req,
398    struct g_part_parms *gpp)
399{
400#if defined(GEOM_PART_EBR_COMPAT)
401	if (req == G_PART_CTL_DESTROY)
402		return (0);
403	return (ECANCELED);
404#else
405	/*
406	 * The index is a function of the start of the partition.
407	 * This is not something the user can override, nor is it
408	 * something the common code will do right. We can set the
409	 * index now so that we get what we need.
410	 */
411	if (req == G_PART_CTL_ADD)
412		gpp->gpp_index = (gpp->gpp_start / table->gpt_sectors) + 1;
413	return (0);
414#endif
415}
416
417static int
418g_part_ebr_probe(struct g_part_table *table, struct g_consumer *cp)
419{
420	char type[64];
421	struct g_provider *pp;
422	u_char *buf, *p;
423	int error, index, res;
424	uint16_t magic;
425
426	pp = cp->provider;
427
428	/* Sanity-check the provider. */
429	if (pp->sectorsize < EBRSIZE || pp->mediasize < pp->sectorsize)
430		return (ENOSPC);
431	if (pp->sectorsize > 4096)
432		return (ENXIO);
433
434	/* Check that we have a parent and that it's a MBR. */
435	if (table->gpt_depth == 0)
436		return (ENXIO);
437	error = g_getattr("PART::scheme", cp, &type);
438	if (error != 0)
439		return (error);
440	if (strcmp(type, "MBR") != 0)
441		return (ENXIO);
442	/* Check that partition has type DOSPTYP_EBR. */
443	error = g_getattr("PART::type", cp, &type);
444	if (error != 0)
445		return (error);
446	if (strcmp(type, "ebr") != 0)
447		return (ENXIO);
448
449	/* Check that there's a EBR. */
450	buf = g_read_data(cp, 0L, pp->sectorsize, &error);
451	if (buf == NULL)
452		return (error);
453
454	/* We goto out on mismatch. */
455	res = ENXIO;
456
457	magic = le16dec(buf + DOSMAGICOFFSET);
458	if (magic != DOSMAGIC)
459		goto out;
460
461	for (index = 0; index < 2; index++) {
462		p = buf + DOSPARTOFF + index * DOSPARTSIZE;
463		if (p[0] != 0 && p[0] != 0x80)
464			goto out;
465	}
466	res = G_PART_PROBE_PRI_NORM;
467
468 out:
469	g_free(buf);
470	return (res);
471}
472
473static int
474g_part_ebr_read(struct g_part_table *basetable, struct g_consumer *cp)
475{
476	struct dos_partition ent[2];
477	struct g_provider *pp;
478	struct g_part_entry *baseentry;
479	struct g_part_ebr_table *table;
480	struct g_part_ebr_entry *entry;
481	u_char *buf;
482	off_t ofs, msize;
483	u_int lba;
484	int error, index;
485
486	pp = cp->provider;
487	table = (struct g_part_ebr_table *)basetable;
488	msize = MIN(pp->mediasize / pp->sectorsize, UINT32_MAX);
489
490	lba = 0;
491	while (1) {
492		ofs = (off_t)lba * pp->sectorsize;
493		buf = g_read_data(cp, ofs, pp->sectorsize, &error);
494		if (buf == NULL)
495			return (error);
496
497		ebr_entry_decode(buf + DOSPARTOFF + 0 * DOSPARTSIZE, ent + 0);
498		ebr_entry_decode(buf + DOSPARTOFF + 1 * DOSPARTSIZE, ent + 1);
499
500		/* The 3rd & 4th entries should be zeroes. */
501		if (le64dec(buf + DOSPARTOFF + 2 * DOSPARTSIZE) +
502		    le64dec(buf + DOSPARTOFF + 3 * DOSPARTSIZE) != 0) {
503			basetable->gpt_corrupt = 1;
504			printf("GEOM: %s: invalid entries in the EBR ignored.\n",
505			    pp->name);
506		}
507#ifndef GEOM_PART_EBR_COMPAT
508		/* Save the first EBR, it can contain a boot code */
509		if (lba == 0)
510			bcopy(buf, table->ebr, sizeof(table->ebr));
511#endif
512		g_free(buf);
513
514		if (ent[0].dp_typ == 0)
515			break;
516
517		if (ent[0].dp_typ == 5 && ent[1].dp_typ == 0) {
518			lba = ent[0].dp_start;
519			continue;
520		}
521
522		index = (lba / basetable->gpt_sectors) + 1;
523		baseentry = (struct g_part_entry *)g_part_new_entry(basetable,
524		    index, lba, lba + ent[0].dp_start + ent[0].dp_size - 1);
525		baseentry->gpe_offset = (off_t)(lba + ent[0].dp_start) *
526		    pp->sectorsize;
527		entry = (struct g_part_ebr_entry *)baseentry;
528		entry->ent = ent[0];
529
530		if (ent[1].dp_typ == 0)
531			break;
532
533		lba = ent[1].dp_start;
534	}
535
536	basetable->gpt_entries = msize / basetable->gpt_sectors;
537	basetable->gpt_first = 0;
538	basetable->gpt_last = msize - 1;
539	return (0);
540}
541
542static int
543g_part_ebr_setunset(struct g_part_table *table, struct g_part_entry *baseentry,
544    const char *attrib, unsigned int set)
545{
546	struct g_part_entry *iter;
547	struct g_part_ebr_entry *entry;
548	int changed;
549
550	if (baseentry == NULL)
551		return (ENODEV);
552	if (strcasecmp(attrib, "active") != 0)
553		return (EINVAL);
554
555	/* Only one entry can have the active attribute. */
556	LIST_FOREACH(iter, &table->gpt_entry, gpe_entry) {
557		if (iter->gpe_deleted)
558			continue;
559		changed = 0;
560		entry = (struct g_part_ebr_entry *)iter;
561		if (iter == baseentry) {
562			if (set && (entry->ent.dp_flag & 0x80) == 0) {
563				entry->ent.dp_flag |= 0x80;
564				changed = 1;
565			} else if (!set && (entry->ent.dp_flag & 0x80)) {
566				entry->ent.dp_flag &= ~0x80;
567				changed = 1;
568			}
569		} else {
570			if (set && (entry->ent.dp_flag & 0x80)) {
571				entry->ent.dp_flag &= ~0x80;
572				changed = 1;
573			}
574		}
575		if (changed && !iter->gpe_created)
576			iter->gpe_modified = 1;
577	}
578	return (0);
579}
580
581static const char *
582g_part_ebr_type(struct g_part_table *basetable, struct g_part_entry *baseentry,
583    char *buf, size_t bufsz)
584{
585	struct g_part_ebr_entry *entry;
586	int i;
587
588	entry = (struct g_part_ebr_entry *)baseentry;
589	for (i = 0;
590	    i < sizeof(ebr_alias_match) / sizeof(ebr_alias_match[0]); i++) {
591		if (ebr_alias_match[i].typ == entry->ent.dp_typ)
592			return (g_part_alias_name(ebr_alias_match[i].alias));
593	}
594	snprintf(buf, bufsz, "!%d", entry->ent.dp_typ);
595	return (buf);
596}
597
598static int
599g_part_ebr_write(struct g_part_table *basetable, struct g_consumer *cp)
600{
601#ifndef GEOM_PART_EBR_COMPAT
602	struct g_part_ebr_table *table;
603#endif
604	struct g_provider *pp;
605	struct g_part_entry *baseentry, *next;
606	struct g_part_ebr_entry *entry;
607	u_char *buf;
608	u_char *p;
609	int error;
610
611	pp = cp->provider;
612	buf = g_malloc(pp->sectorsize, M_WAITOK | M_ZERO);
613#ifndef GEOM_PART_EBR_COMPAT
614	table = (struct g_part_ebr_table *)basetable;
615	bcopy(table->ebr, buf, DOSPARTOFF);
616#endif
617	le16enc(buf + DOSMAGICOFFSET, DOSMAGIC);
618
619	baseentry = LIST_FIRST(&basetable->gpt_entry);
620	while (baseentry != NULL && baseentry->gpe_deleted)
621		baseentry = LIST_NEXT(baseentry, gpe_entry);
622
623	/* Wipe-out the first EBR when there are no slices. */
624	if (baseentry == NULL) {
625		error = g_write_data(cp, 0, buf, pp->sectorsize);
626		goto out;
627	}
628
629	/*
630	 * If the first partition is not in LBA 0, we need to
631	 * put a "link" EBR in LBA 0.
632	 */
633	if (baseentry->gpe_start != 0) {
634		ebr_entry_link(basetable, (uint32_t)baseentry->gpe_start,
635		    (uint32_t)baseentry->gpe_end, buf + DOSPARTOFF);
636		error = g_write_data(cp, 0, buf, pp->sectorsize);
637		if (error)
638			goto out;
639	}
640
641	do {
642		entry = (struct g_part_ebr_entry *)baseentry;
643
644		p = buf + DOSPARTOFF;
645		p[0] = entry->ent.dp_flag;
646		p[1] = entry->ent.dp_shd;
647		p[2] = entry->ent.dp_ssect;
648		p[3] = entry->ent.dp_scyl;
649		p[4] = entry->ent.dp_typ;
650		p[5] = entry->ent.dp_ehd;
651		p[6] = entry->ent.dp_esect;
652		p[7] = entry->ent.dp_ecyl;
653		le32enc(p + 8, entry->ent.dp_start);
654		le32enc(p + 12, entry->ent.dp_size);
655
656		next = LIST_NEXT(baseentry, gpe_entry);
657		while (next != NULL && next->gpe_deleted)
658			next = LIST_NEXT(next, gpe_entry);
659
660		p += DOSPARTSIZE;
661		if (next != NULL)
662			ebr_entry_link(basetable, (uint32_t)next->gpe_start,
663			    (uint32_t)next->gpe_end, p);
664		else
665			bzero(p, DOSPARTSIZE);
666
667		error = g_write_data(cp, baseentry->gpe_start * pp->sectorsize,
668		    buf, pp->sectorsize);
669#ifndef GEOM_PART_EBR_COMPAT
670		if (baseentry->gpe_start == 0)
671			bzero(buf, DOSPARTOFF);
672#endif
673		baseentry = next;
674	} while (!error && baseentry != NULL);
675
676 out:
677	g_free(buf);
678	return (error);
679}
680