FreeBSD/Linux Kernel Cross Reference
sys/geom/geom_gpt.c
1 /*-
2 * Copyright (c) 2002 Marcel Moolenaar
3 * Copyright (c) 2002 Poul-Henning Kamp
4 * Copyright (c) 2002 Networks Associates Technology, Inc.
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 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. The names of the authors may not be used to endorse or promote
16 * products derived from this software without specific prior written
17 * permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD: src/sys/geom/geom_gpt.c,v 1.30 2004/08/08 07:57:51 phk Exp $");
34
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/kernel.h>
38 #include <sys/malloc.h>
39 #include <sys/bio.h>
40 #include <sys/lock.h>
41 #include <sys/mutex.h>
42
43 #include <sys/endian.h>
44 #include <sys/sbuf.h>
45 #include <sys/uuid.h>
46 #include <sys/gpt.h>
47 #include <geom/geom.h>
48 #include <geom/geom_slice.h>
49
50 CTASSERT(offsetof(struct gpt_hdr, padding) == 92);
51 CTASSERT(sizeof(struct gpt_ent) == 128);
52
53 /*
54 * XXX: GEOM is not dynamic enough. We are forced to use a compile-time
55 * limit. The minimum number of partitions (128) as required by EFI is
56 * most of the time just a waste of space.
57 */
58 #define GPT_MAX_SLICES 128
59
60 struct g_gpt_softc {
61 struct gpt_ent *part[GPT_MAX_SLICES];
62 };
63
64 static int
65 is_gpt_hdr(struct gpt_hdr *hdr)
66 {
67 uint32_t crc;
68
69 if (memcmp(hdr->hdr_sig, GPT_HDR_SIG, sizeof(hdr->hdr_sig)))
70 return (0);
71 crc = le32toh(hdr->hdr_crc_self);
72 hdr->hdr_crc_self = 0;
73 if (crc32(hdr, le32toh(hdr->hdr_size)) != crc)
74 return (0);
75 hdr->hdr_crc_self = htole32(crc);
76 /* We're happy... */
77 return (1);
78 }
79
80 static int
81 g_gpt_start(struct bio *bp)
82 {
83
84 return (0);
85 }
86
87 static void
88 g_gpt_dumpconf(struct sbuf *sb, const char *indent, struct g_geom *gp,
89 struct g_consumer *cp, struct g_provider *pp)
90 {
91 struct g_slicer *gsp = gp->softc;
92 struct g_gpt_softc *gs = gsp->softc;
93 struct uuid uuid;
94
95 g_slice_dumpconf(sb, indent, gp, cp, pp);
96
97 if (pp != NULL) {
98 le_uuid_dec(&gs->part[pp->index]->ent_type, &uuid);
99 if (indent != NULL)
100 sbuf_printf(sb, "%s<type>", indent);
101 else
102 sbuf_printf(sb, " ty ");
103 sbuf_printf_uuid(sb, &uuid);
104 if (indent != NULL)
105 sbuf_printf(sb, "</type>\n");
106 }
107 }
108
109 static struct g_geom *
110 g_gpt_taste(struct g_class *mp, struct g_provider *pp, int insist)
111 {
112 struct uuid tmp;
113 struct g_consumer *cp;
114 struct g_geom *gp;
115 struct g_gpt_softc *gs;
116 u_char *buf, *mbr;
117 struct gpt_ent *ent, *part;
118 struct gpt_hdr *hdr;
119 u_int i, secsz, tblsz;
120 int error, ps;
121 uint32_t entries, entsz;
122
123 g_trace(G_T_TOPOLOGY, "g_gpt_taste(%s,%s)", mp->name, pp->name);
124 g_topology_assert();
125
126 /*
127 * XXX: I don't like to hardcode a maximum number of slices, since
128 * it's wasting space most of the time and insufficient any time.
129 * It's easier for now...
130 */
131 gp = g_slice_new(mp, GPT_MAX_SLICES, pp, &cp, &gs, sizeof(*gs),
132 g_gpt_start);
133 if (gp == NULL)
134 return (NULL);
135
136 g_topology_unlock();
137
138 do {
139 mbr = NULL;
140
141 if (gp->rank != 2 && insist == 0)
142 break;
143
144 secsz = cp->provider->sectorsize;
145 if (secsz < 512)
146 break;
147
148 /* XXX: we need to get the media size as well. */
149
150 /* Read both the MBR sector and the GPT sector. */
151 mbr = g_read_data(cp, 0, 2 * secsz, &error);
152 if (mbr == NULL || error != 0)
153 break;
154 #if 0
155 /*
156 * XXX: we should ignore the GPT if there's a MBR and the MBR
157 * is not a PMBR (Protective MBR). I believe this is what the
158 * EFI spec is going to say eventually (this is hearsay :-)
159 * Currently EFI (version 1.02) accepts and uses the GPT even
160 * though there's a valid MBR. We do this too, because it
161 * allows us to test this code without first nuking the only
162 * partitioning scheme we grok until this is working.
163 */
164 if (!is_pmbr((void*)mbr))
165 break;
166 #endif
167 hdr = (void*)(mbr + secsz);
168
169 /*
170 * XXX: if we don't have a GPT header at LBA 1, we should
171 * check if there's a backup GPT at the end of the medium. If
172 * we have a valid backup GPT, we should restore the primary
173 * GPT and claim this lunch.
174 */
175 if (!is_gpt_hdr(hdr))
176 break;
177
178 entries = le32toh(hdr->hdr_entries);
179 entsz = le32toh(hdr->hdr_entsz);
180 tblsz = (entries * entsz + secsz - 1) & ~(secsz - 1);
181 buf = g_read_data(cp, le64toh(hdr->hdr_lba_table) * secsz,
182 tblsz, &error);
183
184 for (i = 0; i < entries; i++) {
185 struct uuid unused = GPT_ENT_TYPE_UNUSED;
186 struct uuid freebsd = GPT_ENT_TYPE_FREEBSD;
187
188 if (i >= GPT_MAX_SLICES)
189 break;
190 ent = (void*)(buf + i * entsz);
191 le_uuid_dec(&ent->ent_type, &tmp);
192 if (!memcmp(&tmp, &unused, sizeof(unused)))
193 continue;
194 /* XXX: This memory leaks */
195 part = gs->part[i] = g_malloc(entsz, M_WAITOK);
196 if (part == NULL)
197 break;
198 part->ent_type = tmp;
199 le_uuid_dec(&ent->ent_uuid, &part->ent_uuid);
200 part->ent_lba_start = le64toh(ent->ent_lba_start);
201 part->ent_lba_end = le64toh(ent->ent_lba_end);
202 part->ent_attr = le64toh(ent->ent_attr);
203 /* XXX do we need to byte-swap UNICODE-16? */
204 bcopy(ent->ent_name, part->ent_name,
205 sizeof(part->ent_name));
206 ps = (!memcmp(&tmp, &freebsd, sizeof(freebsd)))
207 ? 's' : 'p';
208 g_topology_lock();
209 (void)g_slice_config(gp, i, G_SLICE_CONFIG_SET,
210 part->ent_lba_start * secsz,
211 (1 + part->ent_lba_end - part->ent_lba_start) *
212 secsz, secsz, "%s%c%d", gp->name, ps, i + 1);
213 g_topology_unlock();
214 }
215 g_free(buf);
216 } while (0);
217
218 if (mbr != NULL)
219 g_free(mbr);
220
221 g_topology_lock();
222 g_access(cp, -1, 0, 0);
223 if (LIST_EMPTY(&gp->provider)) {
224 g_slice_spoiled(cp);
225 return (NULL);
226 }
227 return (gp);
228 }
229
230 static struct g_class g_gpt_class = {
231 .name = "GPT",
232 .version = G_VERSION,
233 .taste = g_gpt_taste,
234 .dumpconf = g_gpt_dumpconf,
235 };
236
237 DECLARE_GEOM_CLASS(g_gpt_class, g_gpt);
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