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 * $FreeBSD: releng/5.0/sys/geom/geom_gpt.c 108141 2002-12-20 21:52:03Z phk $
32 */
33
34 #include <sys/param.h>
35 #ifndef _KERNEL
36 #include <stdio.h>
37 #include <string.h>
38 #include <signal.h>
39 #include <sys/param.h>
40 #include <stdlib.h>
41 #include <err.h>
42 #else
43 #include <sys/systm.h>
44 #include <sys/kernel.h>
45 #include <sys/malloc.h>
46 #include <sys/bio.h>
47 #include <sys/lock.h>
48 #include <sys/mutex.h>
49 #endif
50
51 #include <sys/endian.h>
52 #include <sys/sbuf.h>
53 #include <sys/uuid.h>
54 #include <sys/gpt.h>
55 #include <geom/geom.h>
56 #include <geom/geom_slice.h>
57
58 CTASSERT(offsetof(struct gpt_hdr, padding) == 92);
59 CTASSERT(sizeof(struct gpt_ent) == 128);
60
61 /*
62 * XXX: GEOM is not dynamic enough. We are forced to use a compile-time
63 * limit. The minimum number of partitions (128) as required by EFI is
64 * most of the time just a waste of space.
65 */
66 #define GPT_MAX_SLICES 128
67
68 struct g_gpt_softc {
69 struct gpt_ent *part[GPT_MAX_SLICES];
70 };
71
72 static int
73 is_gpt_hdr(struct gpt_hdr *hdr)
74 {
75 uint32_t crc;
76
77 if (memcmp(hdr->hdr_sig, GPT_HDR_SIG, sizeof(hdr->hdr_sig)))
78 return (0);
79 crc = hdr->hdr_crc_self;
80 hdr->hdr_crc_self = 0;
81 if (crc32(hdr, hdr->hdr_size) != crc)
82 return (0);
83 hdr->hdr_crc_self = crc;
84 /* We're happy... */
85 return (1);
86 }
87
88 static int
89 g_gpt_start(struct bio *bp)
90 {
91 struct uuid freebsd = GPT_ENT_TYPE_FREEBSD;
92 struct g_provider *pp = bp->bio_to;
93 struct g_geom *gp = pp->geom;
94 struct g_slicer *gsp = gp->softc;
95 struct g_gpt_softc *gs = gsp->softc;
96 u_int type;
97
98 if (bp->bio_cmd != BIO_GETATTR)
99 return (0);
100
101 /*
102 * XXX: this is bogus. The BSD class has a strong dependency on
103 * the MBR/MBREXT class, because it asks for an attribute that's
104 * specific to the MBR/MBREXT class and the value of the attribute
105 * is just as specific to the MBR class. In an extensible scheme
106 * a geom would ask another geom if it could possible accomodate a
107 * class and the answer should be yes or no. Now we're forced to
108 * emulate a MBR class :-/
109 */
110 type = (memcmp(&gs->part[pp->index]->ent_type, &freebsd,
111 sizeof(freebsd))) ? 0 : 165;
112 return ((g_handleattr_int(bp, "MBR::type", type)) ? 1 : 0);
113 }
114
115 static void
116 g_gpt_dumpconf(struct sbuf *sb, const char *indent, struct g_geom *gp,
117 struct g_consumer *cp, struct g_provider *pp)
118 {
119 struct g_slicer *gsp = gp->softc;
120 struct g_gpt_softc *gs = gsp->softc;
121 struct uuid *uuid;
122
123 g_slice_dumpconf(sb, indent, gp, cp, pp);
124
125 if (pp != NULL) {
126 uuid = &gs->part[pp->index]->ent_type;
127 if (indent != NULL)
128 sbuf_printf(sb, "%s<type>", indent);
129 else
130 sbuf_printf(sb, " ty ");
131 sbuf_printf_uuid(sb, uuid);
132 if (indent != NULL)
133 sbuf_printf(sb, "</type>\n");
134 }
135 }
136
137 static struct g_geom *
138 g_gpt_taste(struct g_class *mp, struct g_provider *pp, int insist)
139 {
140 struct g_consumer *cp;
141 struct g_geom *gp;
142 struct g_gpt_softc *gs;
143 struct g_slicer *gsp;
144 u_char *buf, *mbr;
145 struct gpt_ent *ent;
146 struct gpt_hdr *hdr;
147 u_int i, npart, secsz, tblsz;
148 int error, ps;
149
150 g_trace(G_T_TOPOLOGY, "g_gpt_taste(%s,%s)", mp->name, pp->name);
151 g_topology_assert();
152
153 /*
154 * XXX: I don't like to hardcode a maximum number of slices, since
155 * it's wasting space most of the time and insufficient any time.
156 * It's easier for now...
157 */
158 gp = g_slice_new(mp, GPT_MAX_SLICES, pp, &cp, &gs, sizeof(*gs),
159 g_gpt_start);
160 if (gp == NULL)
161 return (NULL);
162
163 gsp = gp->softc;
164 g_topology_unlock();
165 gp->dumpconf = g_gpt_dumpconf;
166
167 do {
168
169 npart = 0;
170 mbr = NULL;
171
172 if (gp->rank != 2 && insist == 0)
173 break;
174
175 secsz = cp->provider->sectorsize;
176 if (secsz < 512)
177 break;
178
179 /* XXX: we need to get the media size as well. */
180
181 /* Read both the MBR sector and the GPT sector. */
182 mbr = g_read_data(cp, 0, 2 * secsz, &error);
183 if (mbr == NULL || error != 0)
184 break;
185 #if 0
186 /*
187 * XXX: we should ignore the GPT if there's a MBR and the MBR is
188 * not a PMBR (Protective MBR). I believe this is what the EFI
189 * spec is going to say eventually (this is hearsay :-)
190 * Currently EFI (version 1.02) accepts and uses the GPT even
191 * though there's a valid MBR. We do this too, because it allows
192 * us to test this code without first nuking the only partitioning
193 * scheme we grok until this is working.
194 */
195 if (!is_pmbr((void*)mbr))
196 goto out;
197 #endif
198
199 hdr = (void*)(mbr + secsz);
200
201 /*
202 * XXX: if we don't have a GPT header at LBA 1, we should check if
203 * there's a backup GPT at the end of the medium. If we have a valid
204 * backup GPT, we should restore the primary GPT and claim this lunch.
205 */
206 if (!is_gpt_hdr(hdr))
207 break;
208
209 tblsz = (hdr->hdr_entries * hdr->hdr_entsz + secsz - 1) &
210 ~(secsz - 1);
211 buf = g_read_data(cp, hdr->hdr_lba_table * secsz, tblsz, &error);
212
213 gsp->frontstuff = hdr->hdr_lba_start * secsz;
214
215 for (i = 0; i < hdr->hdr_entries; i++) {
216 struct uuid unused = GPT_ENT_TYPE_UNUSED;
217 struct uuid freebsd = GPT_ENT_TYPE_FREEBSD;
218 if (i >= GPT_MAX_SLICES)
219 break;
220 ent = (void*)(buf + i * hdr->hdr_entsz);
221 if (!memcmp(&ent->ent_type, &unused, sizeof(unused)))
222 continue;
223 gs->part[i] = g_malloc(hdr->hdr_entsz, M_WAITOK);
224 if (gs->part[i] == NULL)
225 break;
226 bcopy(ent, gs->part[i], hdr->hdr_entsz);
227 ps = (!memcmp(&ent->ent_type, &freebsd, sizeof(freebsd)))
228 ? 's' : 'p';
229 g_topology_lock();
230 (void)g_slice_config(gp, i, G_SLICE_CONFIG_SET,
231 ent->ent_lba_start * secsz,
232 (1 + ent->ent_lba_end - ent->ent_lba_start) * secsz,
233 secsz,
234 "%s%c%d", gp->name, ps, i + 1);
235 g_topology_unlock();
236 npart++;
237 }
238 g_free(buf);
239
240 } while (0);
241
242
243 if (mbr != NULL)
244 g_free(mbr);
245
246 g_topology_lock();
247 g_access_rel(cp, -1, 0, 0);
248 if (LIST_EMPTY(&gp->provider)) {
249 g_std_spoiled(cp);
250 return (NULL);
251 }
252 return (gp);
253 }
254
255 static struct g_class g_gpt_class = {
256 "GPT",
257 g_gpt_taste,
258 NULL,
259 G_CLASS_INITIALIZER
260 };
261
262 DECLARE_GEOM_CLASS(g_gpt_class, g_gpt);
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