xref: /dragonfly/sys/kern/subr_diskgpt.c (revision cecb9aae)
1 /*
2  * Copyright (c) 2007 The DragonFly Project.  All rights reserved.
3  *
4  * This code is derived from software contributed to The DragonFly Project
5  * by Matthew Dillon <dillon@backplane.com>
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
15  *    the documentation and/or other materials provided with the
16  *    distribution.
17  * 3. Neither the name of The DragonFly Project nor the names of its
18  *    contributors may be used to endorse or promote products derived
19  *    from this software without specific, prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  */
34 
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/conf.h>
38 #include <sys/endian.h>
39 #include <sys/diskslice.h>
40 #include <sys/diskmbr.h>
41 #include <sys/disk.h>
42 #include <sys/buf.h>
43 #include <sys/malloc.h>
44 #include <sys/syslog.h>
45 #include <sys/bus.h>
46 #include <sys/device.h>
47 #include <sys/gpt.h>
48 
49 static void gpt_setslice(const char *sname, struct disk_info *info,
50 			 struct diskslice *sp, struct gpt_ent *sent);
51 
52 /*
53  * Handle GPT on raw disk.  Note that GPTs are not recursive.  The MBR is
54  * ignored once a GPT has been detected.
55  *
56  * GPTs always start at block #1, regardless of how the MBR has been set up.
57  * In fact, the MBR's starting block might be pointing to the boot partition
58  * in the GPT rather then to the start of the GPT.
59  *
60  * This routine is called from mbrinit() when a GPT has been detected.
61  */
62 int
63 gptinit(cdev_t dev, struct disk_info *info, struct diskslices **sspp)
64 {
65 	struct buf *bp1 = NULL;
66 	struct buf *bp2 = NULL;
67 	struct gpt_hdr *gpt;
68 	struct gpt_ent *ent;
69 	struct diskslice *sp;
70 	struct diskslices *ssp;
71 	cdev_t wdev;
72 	int error;
73 	uint32_t len;
74 	uint32_t entries;
75 	uint32_t entsz;
76 	uint32_t crc;
77 	uint32_t table_lba;
78 	uint32_t table_blocks;
79 	int i = 0, j;
80 	const char *dname;
81 
82 	/*
83 	 * The GPT starts in sector 1.
84 	 */
85 	wdev = dev;
86 	dname = dev_dname(wdev);
87 	bp1 = geteblk((int)info->d_media_blksize);
88 	bp1->b_bio1.bio_offset = info->d_media_blksize;
89 	bp1->b_bio1.bio_done = biodone_sync;
90 	bp1->b_bio1.bio_flags |= BIO_SYNC;
91 	bp1->b_bcount = info->d_media_blksize;
92 	bp1->b_cmd = BUF_CMD_READ;
93 	dev_dstrategy(wdev, &bp1->b_bio1);
94 	if (biowait(&bp1->b_bio1, "gptrd") != 0) {
95 		kprintf("%s: reading GPT @ block 1: error %d\n",
96 			dname, bp1->b_error);
97 		error = EIO;
98 		goto done;
99 	}
100 
101 	/*
102 	 * Header sanity check
103 	 */
104 	gpt = (void *)bp1->b_data;
105 	len = le32toh(gpt->hdr_size);
106 	if (len < GPT_MIN_HDR_SIZE || len > info->d_media_blksize) {
107 		kprintf("%s: Illegal GPT header size %d\n", dname, len);
108 		error = EINVAL;
109 		goto done;
110 	}
111 
112 	crc = le32toh(gpt->hdr_crc_self);
113 	gpt->hdr_crc_self = 0;
114 	if (crc32(gpt, len) != crc) {
115 		kprintf("%s: GPT CRC32 did not match\n", dname);
116 		error = EINVAL;
117 		goto done;
118 	}
119 
120 	/*
121 	 * Validate the partition table and its location, then read it
122 	 * into a buffer.
123 	 */
124 	entries = le32toh(gpt->hdr_entries);
125 	entsz = le32toh(gpt->hdr_entsz);
126 	table_lba = le32toh(gpt->hdr_lba_table);
127 	table_blocks = (entries * entsz + info->d_media_blksize - 1) /
128 		       info->d_media_blksize;
129 	if (entries < 1 || entries > 128 ||
130 	    entsz < 128 || (entsz & 7) || entsz > MAXBSIZE / entries ||
131 	    table_lba < 2 || table_lba + table_blocks > info->d_media_blocks) {
132 		kprintf("%s: GPT partition table is out of bounds\n", dname);
133 		error = EINVAL;
134 		goto done;
135 	}
136 
137 	/*
138 	 * XXX subject to device dma size limitations
139 	 */
140 	bp2 = geteblk((int)(table_blocks * info->d_media_blksize));
141 	bp2->b_bio1.bio_offset = (off_t)table_lba * info->d_media_blksize;
142 	bp2->b_bio1.bio_done = biodone_sync;
143 	bp2->b_bio1.bio_flags |= BIO_SYNC;
144 	bp2->b_bcount = table_blocks * info->d_media_blksize;
145 	bp2->b_cmd = BUF_CMD_READ;
146 	dev_dstrategy(wdev, &bp2->b_bio1);
147 	if (biowait(&bp2->b_bio1, "gptrd") != 0) {
148 		kprintf("%s: reading GPT partition table @ %lld: error %d\n",
149 			dname,
150 			(long long)bp2->b_bio1.bio_offset,
151 			bp2->b_error);
152 		error = EIO;
153 		goto done;
154 	}
155 
156 	/*
157 	 * We are passed a pointer to a minimal slices struct.  Replace
158 	 * it with a maximal one (128 slices + special slices).  Well,
159 	 * really there is only one special slice (the WHOLE_DISK_SLICE)
160 	 * since we use the compatibility slice for s0, but don't quibble.
161 	 *
162 	 */
163 	kfree(*sspp, M_DEVBUF);
164 	ssp = *sspp = dsmakeslicestruct(BASE_SLICE+128, info);
165 
166 	/*
167 	 * Create a slice for each partition.
168 	 */
169 	for (i = 0; i < (int)entries && i < 128; ++i) {
170 		struct gpt_ent sent;
171 		char partname[2];
172 		char *sname;
173 
174 		ent = (void *)((char *)bp2->b_data + i * entsz);
175 		le_uuid_dec(&ent->ent_type, &sent.ent_type);
176 		le_uuid_dec(&ent->ent_uuid, &sent.ent_uuid);
177 		sent.ent_lba_start = le64toh(ent->ent_lba_start);
178 		sent.ent_lba_end = le64toh(ent->ent_lba_end);
179 		sent.ent_attr = le64toh(ent->ent_attr);
180 
181 		for (j = 0; j < NELEM(ent->ent_name); ++j)
182 			sent.ent_name[j] = le16toh(ent->ent_name[j]);
183 
184 		/*
185 		 * The COMPATIBILITY_SLICE is actually slice 0 (s0).  This
186 		 * is a bit weird becaue the whole-disk slice is #1, so
187 		 * slice 1 (s1) starts at BASE_SLICE.
188 		 */
189 		if (i == 0)
190 			sp = &ssp->dss_slices[COMPATIBILITY_SLICE];
191 		else
192 			sp = &ssp->dss_slices[BASE_SLICE+i-1];
193 		sname = dsname(dev, dkunit(dev), WHOLE_DISK_SLICE,
194 			       WHOLE_SLICE_PART, partname);
195 
196 		if (kuuid_is_nil(&sent.ent_type))
197 			continue;
198 
199 		if (sent.ent_lba_start < table_lba + table_blocks ||
200 		    sent.ent_lba_end >= info->d_media_blocks ||
201 		    sent.ent_lba_start >= sent.ent_lba_end) {
202 			kprintf("%s part %d: unavailable, bad start or "
203 				"ending lba\n",
204 				sname, i);
205 		} else {
206 			gpt_setslice(sname, info, sp, &sent);
207 		}
208 	}
209 	ssp->dss_nslices = BASE_SLICE + i;
210 
211 	error = 0;
212 done:
213 	if (bp1) {
214 		bp1->b_flags |= B_INVAL | B_AGE;
215 		brelse(bp1);
216 	}
217 	if (bp2) {
218 		bp2->b_flags |= B_INVAL | B_AGE;
219 		brelse(bp2);
220 	}
221 	if (error == EINVAL)
222 		error = 0;
223 	return (error);
224 }
225 
226 static
227 void
228 gpt_setslice(const char *sname, struct disk_info *info, struct diskslice *sp,
229 	     struct gpt_ent *sent)
230 {
231 	sp->ds_offset = sent->ent_lba_start;
232 	sp->ds_size   = sent->ent_lba_end + 1 - sent->ent_lba_start;
233 	sp->ds_type   = 1;	/* XXX */
234 	sp->ds_type_uuid = sent->ent_type;
235 	sp->ds_stor_uuid = sent->ent_uuid;
236 	sp->ds_reserved = 0;	/* no reserved sectors */
237 }
238 
239