summaryrefslogtreecommitdiffstats
path: root/grub-core/disk/mdraid1x_linux.c
blob: 38444b02c7834bb2de79998c342af69a63ea9873 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
/* mdraid_linux.c - module to handle Linux Software RAID.  */
/*
 *  GRUB  --  GRand Unified Bootloader
 *  Copyright (C) 2008,2009,2010  Free Software Foundation, Inc.
 *
 *  GRUB is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  GRUB is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <grub/dl.h>
#include <grub/disk.h>
#include <grub/mm.h>
#include <grub/err.h>
#include <grub/misc.h>
#include <grub/diskfilter.h>

GRUB_MOD_LICENSE ("GPLv3+");

/* Linux RAID on disk structures and constants,
   copied from include/linux/raid/md_p.h.  */

#define SB_MAGIC			0xa92b4efc

/*
 * The version-1 superblock :
 * All numeric fields are little-endian.
 *
 * Total size: 256 bytes plus 2 per device.
 * 1K allows 384 devices.
 */

struct grub_raid_super_1x
{
  /* Constant array information - 128 bytes.  */
  grub_uint32_t magic;		/* MD_SB_MAGIC: 0xa92b4efc - little endian.  */
  grub_uint32_t major_version;	/* 1.  */
  grub_uint32_t feature_map;	/* Bit 0 set if 'bitmap_offset' is meaningful.   */
  grub_uint32_t pad0;		/* Always set to 0 when writing.  */

  grub_uint8_t set_uuid[16];	/* User-space generated.  */
  char set_name[32];		/* Set and interpreted by user-space.  */

  grub_uint64_t ctime;		/* Lo 40 bits are seconds, top 24 are microseconds or 0.  */
  grub_uint32_t level;		/* -4 (multipath), -1 (linear), 0,1,4,5.  */
  grub_uint32_t layout;		/* only for raid5 and raid10 currently.  */
  grub_uint64_t size;		/* Used size of component devices, in 512byte sectors.  */

  grub_uint32_t chunksize;	/* In 512byte sectors.  */
  grub_uint32_t raid_disks;
  grub_uint32_t bitmap_offset;	/* Sectors after start of superblock that bitmap starts
				 * NOTE: signed, so bitmap can be before superblock
				 * only meaningful of feature_map[0] is set.
				 */

  /* These are only valid with feature bit '4'.  */
  grub_uint32_t new_level;	/* New level we are reshaping to.  */
  grub_uint64_t reshape_position;	/* Next address in array-space for reshape.  */
  grub_uint32_t delta_disks;	/* Change in number of raid_disks.  */
  grub_uint32_t new_layout;	/* New layout.  */
  grub_uint32_t new_chunk;	/* New chunk size (512byte sectors).  */
  grub_uint8_t pad1[128 - 124];	/* Set to 0 when written.  */

  /* Constant this-device information - 64 bytes.  */
  grub_uint64_t data_offset;	/* Sector start of data, often 0.  */
  grub_uint64_t data_size;	/* Sectors in this device that can be used for data.  */
  grub_uint64_t super_offset;	/* Sector start of this superblock.  */
  grub_uint64_t recovery_offset;	/* Sectors before this offset (from data_offset) have been recovered.  */
  grub_uint32_t dev_number;	/* Permanent identifier of this  device - not role in raid.  */
  grub_uint32_t cnt_corrected_read;	/* Number of read errors that were corrected by re-writing.  */
  grub_uint8_t device_uuid[16];	/* User-space setable, ignored by kernel.  */
  grub_uint8_t devflags;	/* Per-device flags.  Only one defined...  */
  grub_uint8_t pad2[64 - 57];	/* Set to 0 when writing.  */

  /* Array state information - 64 bytes.  */
  grub_uint64_t utime;		/* 40 bits second, 24 btes microseconds.  */
  grub_uint64_t events;		/* Incremented when superblock updated.  */
  grub_uint64_t resync_offset;	/* Data before this offset (from data_offset) known to be in sync.  */
  grub_uint32_t sb_csum;	/* Checksum upto devs[max_dev].  */
  grub_uint32_t max_dev;	/* Size of devs[] array to consider.  */
  grub_uint8_t pad3[64 - 32];	/* Set to 0 when writing.  */

  /* Device state information. Indexed by dev_number.
   * 2 bytes per device.
   * Note there are no per-device state flags. State information is rolled
   * into the 'roles' value.  If a device is spare or faulty, then it doesn't
   * have a meaningful role.
   */
  grub_uint16_t dev_roles[0];	/* Role in array, or 0xffff for a spare, or 0xfffe for faulty.  */
};
/* Could be GRUB_PACKED, but since all members in this struct
   are already appropriately aligned, we can omit this and avoid suboptimal
   assembly in some cases.  */

#define WriteMostly1    1	/* Mask for writemostly flag in above devflags.  */

static struct grub_diskfilter_vg *
grub_mdraid_detect (grub_disk_t disk,
		    struct grub_diskfilter_pv_id *id,
		    grub_disk_addr_t *start_sector)
{
  grub_uint64_t size;
  grub_uint8_t minor_version;

  size = grub_disk_native_sectors (disk);

  /* Check for an 1.x superblock.
   * It's always aligned to a 4K boundary
   * and depending on the minor version it can be:
   * 0: At least 8K, but less than 12K, from end of device
   * 1: At start of device
   * 2: 4K from start of device.
   */

  for (minor_version = 0; minor_version < 3; ++minor_version)
    {
      grub_disk_addr_t sector = 0;
      struct grub_raid_super_1x sb;
      grub_uint16_t role;
      grub_uint32_t level;
      struct grub_diskfilter_vg *array;
      char *uuid;
	
      if (size == GRUB_DISK_SIZE_UNKNOWN && minor_version == 0)
	continue;
	
      switch (minor_version)
	{
	case 0:
	  sector = (size - 8 * 2) & ~(4 * 2 - 1);
	  break;
	case 1:
	  sector = 0;
	  break;
	case 2:
	  sector = 4 * 2;
	  break;
	}

      if (grub_disk_read (disk, sector, 0, sizeof (struct grub_raid_super_1x),
			  &sb))
	return NULL;

      if (sb.magic != grub_cpu_to_le32_compile_time (SB_MAGIC)
	  || grub_le_to_cpu64 (sb.super_offset) != sector)
	continue;

      if (sb.major_version != grub_cpu_to_le32_compile_time (1))
	/* Unsupported version.  */
	return NULL;

      level = grub_le_to_cpu32 (sb.level);

      /* Multipath.  */
      if ((int) level == -4)
	level = 1;

      if (level != 0 && level != 1 && level != 4 &&
	  level != 5 && level != 6 && level != 10)
	{
	  grub_error (GRUB_ERR_NOT_IMPLEMENTED_YET,
		      "Unsupported RAID level: %d", sb.level);
	  return NULL;
	}

      if (grub_le_to_cpu32 (sb.dev_number) >=
	  grub_le_to_cpu32 (sb.max_dev))
	/* Spares aren't implemented.  */
	return NULL;

      if (grub_disk_read (disk, sector, 
			  (char *) (sb.dev_roles + grub_le_to_cpu32 (sb.dev_number))
			  - (char *) &sb,
			  sizeof (role), &role))
	return NULL;

      if (grub_le_to_cpu16 (role)
	  >= grub_le_to_cpu32 (sb.raid_disks))
	/* Spares aren't implemented.  */
	return NULL;

      id->uuidlen = 0;
      id->id = grub_le_to_cpu16 (role);

      uuid = grub_malloc (16);
      if (!uuid)
	return NULL;

      grub_memcpy (uuid, sb.set_uuid, 16);

      *start_sector = grub_le_to_cpu64 (sb.data_offset);

      array = grub_diskfilter_make_raid (16, uuid,
					 grub_le_to_cpu32 (sb.raid_disks),
					 sb.set_name,
					 (sb.size)
					 ? grub_le_to_cpu64 (sb.size) 
					 : grub_le_to_cpu64 (sb.data_size),
					 grub_le_to_cpu32 (sb.chunksize),
					 grub_le_to_cpu32 (sb.layout),
					 grub_le_to_cpu32 (sb.level));

      return array;
    }

  /* not 1.x raid.  */
  return NULL;
}

static struct grub_diskfilter grub_mdraid_dev = {
  .name = "mdraid1x",
  .detect = grub_mdraid_detect,
  .next = 0
};

GRUB_MOD_INIT (mdraid1x)
{
  grub_diskfilter_register_front (&grub_mdraid_dev);
}

GRUB_MOD_FINI (mdraid1x)
{
  grub_diskfilter_unregister (&grub_mdraid_dev);
}