2 * Copyright (C) 1999, 2001 by Andries Brouwer
3 * Copyright (C) 1999, 2000, 2003 by Theodore Ts'o
4 * Copyright (C) 2008 Karel Zak <kzak@redhat.com>
6 * This file may be redistributed under the terms of the
7 * GNU Lesser General Public License.
17 #include <sys/utsname.h>
21 #include "superblocks.h"
23 struct ext2_super_block {
24 uint32_t s_inodes_count;
25 uint32_t s_blocks_count;
26 uint32_t s_r_blocks_count;
27 uint32_t s_free_blocks_count;
28 uint32_t s_free_inodes_count;
29 uint32_t s_first_data_block;
30 uint32_t s_log_block_size;
32 unsigned char s_magic[2];
35 uint16_t s_minor_rev_level;
37 uint32_t s_checkinterval;
38 uint32_t s_creator_os;
40 uint16_t s_def_resuid;
41 uint16_t s_def_resgid;
43 uint16_t s_inode_size;
44 uint16_t s_block_group_nr;
45 uint32_t s_feature_compat;
46 uint32_t s_feature_incompat;
47 uint32_t s_feature_ro_compat;
48 unsigned char s_uuid[16];
49 char s_volume_name[16];
50 char s_last_mounted[64];
51 uint32_t s_algorithm_usage_bitmap;
52 uint8_t s_prealloc_blocks;
53 uint8_t s_prealloc_dir_blocks;
54 uint16_t s_reserved_gdt_blocks;
55 uint8_t s_journal_uuid[16];
56 uint32_t s_journal_inum;
57 uint32_t s_journal_dev;
58 uint32_t s_last_orphan;
59 uint32_t s_hash_seed[4];
60 uint8_t s_def_hash_version;
61 uint8_t s_jnl_backup_type;
62 uint16_t s_reserved_word_pad;
63 uint32_t s_default_mount_opts;
64 uint32_t s_first_meta_bg;
66 uint32_t s_jnl_blocks[17];
67 uint32_t s_blocks_count_hi;
68 uint32_t s_r_blocks_count_hi;
69 uint32_t s_free_blocks_hi;
70 uint16_t s_min_extra_isize;
71 uint16_t s_want_extra_isize;
73 uint16_t s_raid_stride;
74 uint16_t s_mmp_interval;
76 uint32_t s_raid_stripe_width;
77 uint32_t s_reserved[163];
78 } __attribute__((packed));
81 #define EXT_SB_MAGIC "\123\357"
82 /* supper block offset */
83 #define EXT_SB_OFF 0x400
84 /* supper block offset in kB */
85 #define EXT_SB_KBOFF (EXT_SB_OFF >> 10)
86 /* magic string offset within super block */
87 #define EXT_MAG_OFF 0x38
92 #define EXT2_FLAGS_TEST_FILESYS 0x0004
94 /* for s_feature_compat */
95 #define EXT3_FEATURE_COMPAT_HAS_JOURNAL 0x0004
97 /* for s_feature_ro_compat */
98 #define EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER 0x0001
99 #define EXT2_FEATURE_RO_COMPAT_LARGE_FILE 0x0002
100 #define EXT2_FEATURE_RO_COMPAT_BTREE_DIR 0x0004
101 #define EXT4_FEATURE_RO_COMPAT_HUGE_FILE 0x0008
102 #define EXT4_FEATURE_RO_COMPAT_GDT_CSUM 0x0010
103 #define EXT4_FEATURE_RO_COMPAT_DIR_NLINK 0x0020
104 #define EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE 0x0040
106 /* for s_feature_incompat */
107 #define EXT2_FEATURE_INCOMPAT_FILETYPE 0x0002
108 #define EXT3_FEATURE_INCOMPAT_RECOVER 0x0004
109 #define EXT3_FEATURE_INCOMPAT_JOURNAL_DEV 0x0008
110 #define EXT2_FEATURE_INCOMPAT_META_BG 0x0010
111 #define EXT4_FEATURE_INCOMPAT_EXTENTS 0x0040 /* extents support */
112 #define EXT4_FEATURE_INCOMPAT_64BIT 0x0080
113 #define EXT4_FEATURE_INCOMPAT_MMP 0x0100
114 #define EXT4_FEATURE_INCOMPAT_FLEX_BG 0x0200
116 #define EXT2_FEATURE_RO_COMPAT_SUPP (EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER| \
117 EXT2_FEATURE_RO_COMPAT_LARGE_FILE| \
118 EXT2_FEATURE_RO_COMPAT_BTREE_DIR)
119 #define EXT2_FEATURE_INCOMPAT_SUPP (EXT2_FEATURE_INCOMPAT_FILETYPE| \
120 EXT2_FEATURE_INCOMPAT_META_BG)
121 #define EXT2_FEATURE_INCOMPAT_UNSUPPORTED ~EXT2_FEATURE_INCOMPAT_SUPP
122 #define EXT2_FEATURE_RO_COMPAT_UNSUPPORTED ~EXT2_FEATURE_RO_COMPAT_SUPP
124 #define EXT3_FEATURE_RO_COMPAT_SUPP (EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER| \
125 EXT2_FEATURE_RO_COMPAT_LARGE_FILE| \
126 EXT2_FEATURE_RO_COMPAT_BTREE_DIR)
127 #define EXT3_FEATURE_INCOMPAT_SUPP (EXT2_FEATURE_INCOMPAT_FILETYPE| \
128 EXT3_FEATURE_INCOMPAT_RECOVER| \
129 EXT2_FEATURE_INCOMPAT_META_BG)
130 #define EXT3_FEATURE_INCOMPAT_UNSUPPORTED ~EXT3_FEATURE_INCOMPAT_SUPP
131 #define EXT3_FEATURE_RO_COMPAT_UNSUPPORTED ~EXT3_FEATURE_RO_COMPAT_SUPP
134 * Starting in 2.6.29, ext4 can be used to support filesystems
137 #define EXT4_SUPPORTS_EXT2 KERNEL_VERSION(2, 6, 29)
140 * reads superblock and returns:
141 * fc = feature_compat
142 * fi = feature_incompat
143 * frc = feature_ro_compat
145 static struct ext2_super_block *ext_get_super(
146 blkid_probe pr, uint32_t *fc, uint32_t *fi, uint32_t *frc)
148 struct ext2_super_block *es;
150 es = (struct ext2_super_block *)
151 blkid_probe_get_buffer(pr, EXT_SB_OFF, 0x200);
155 *fc = le32_to_cpu(es->s_feature_compat);
157 *fi = le32_to_cpu(es->s_feature_incompat);
159 *frc = le32_to_cpu(es->s_feature_ro_compat);
164 static void ext_get_info(blkid_probe pr, int ver, struct ext2_super_block *es)
167 struct blkid_chain *chn = blkid_probe_get_chain(pr);
170 DBG(PROBE, ul_debug("ext2_sb.compat = %08X:%08X:%08X",
171 le32_to_cpu(es->s_feature_compat),
172 le32_to_cpu(es->s_feature_incompat),
173 le32_to_cpu(es->s_feature_ro_compat)));
175 if (strlen(es->s_volume_name))
176 blkid_probe_set_label(pr, (unsigned char *) es->s_volume_name,
177 sizeof(es->s_volume_name));
178 blkid_probe_set_uuid(pr, es->s_uuid);
180 if (le32_to_cpu(es->s_feature_compat) & EXT3_FEATURE_COMPAT_HAS_JOURNAL)
181 blkid_probe_set_uuid_as(pr, es->s_journal_uuid, "EXT_JOURNAL");
184 if (ver != 2 && (chn->flags & BLKID_SUBLKS_SECTYPE) &&
185 ((le32_to_cpu(es->s_feature_incompat) & EXT2_FEATURE_INCOMPAT_UNSUPPORTED) == 0))
186 blkid_probe_set_value(pr, "SEC_TYPE",
187 (unsigned char *) "ext2",
191 blkid_probe_sprintf_version(pr, "%u.%u",
192 le32_to_cpu(es->s_rev_level),
193 le16_to_cpu(es->s_minor_rev_level));
197 static int probe_jbd(blkid_probe pr,
198 const struct blkid_idmag *mag __attribute__((__unused__)))
200 struct ext2_super_block *es;
203 es = ext_get_super(pr, NULL, &fi, NULL);
205 return errno ? -errno : 1;
206 if (!(fi & EXT3_FEATURE_INCOMPAT_JOURNAL_DEV))
209 ext_get_info(pr, 2, es);
210 blkid_probe_set_uuid_as(pr, es->s_uuid, "LOGUUID");
215 static int probe_ext2(blkid_probe pr,
216 const struct blkid_idmag *mag __attribute__((__unused__)))
218 struct ext2_super_block *es;
219 uint32_t fc, frc, fi;
221 es = ext_get_super(pr, &fc, &fi, &frc);
223 return errno ? -errno : 1;
225 /* Distinguish between ext3 and ext2 */
226 if (fc & EXT3_FEATURE_COMPAT_HAS_JOURNAL)
229 /* Any features which ext2 doesn't understand */
230 if ((frc & EXT2_FEATURE_RO_COMPAT_UNSUPPORTED) ||
231 (fi & EXT2_FEATURE_INCOMPAT_UNSUPPORTED))
234 ext_get_info(pr, 2, es);
238 static int probe_ext3(blkid_probe pr,
239 const struct blkid_idmag *mag __attribute__((__unused__)))
241 struct ext2_super_block *es;
242 uint32_t fc, frc, fi;
244 es = ext_get_super(pr, &fc, &fi, &frc);
246 return errno ? -errno : 1;
248 /* ext3 requires journal */
249 if (!(fc & EXT3_FEATURE_COMPAT_HAS_JOURNAL))
252 /* Any features which ext3 doesn't understand */
253 if ((frc & EXT3_FEATURE_RO_COMPAT_UNSUPPORTED) ||
254 (fi & EXT3_FEATURE_INCOMPAT_UNSUPPORTED))
257 ext_get_info(pr, 3, es);
262 static int probe_ext4dev(blkid_probe pr,
263 const struct blkid_idmag *mag __attribute__((__unused__)))
265 struct ext2_super_block *es;
266 uint32_t fc, frc, fi;
268 es = ext_get_super(pr, &fc, &fi, &frc);
270 return errno ? -errno : 1;
272 /* Distinguish from jbd */
273 if (fi & EXT3_FEATURE_INCOMPAT_JOURNAL_DEV)
276 if (!(le32_to_cpu(es->s_flags) & EXT2_FLAGS_TEST_FILESYS))
279 ext_get_info(pr, 4, es);
283 static int probe_ext4(blkid_probe pr,
284 const struct blkid_idmag *mag __attribute__((__unused__)))
286 struct ext2_super_block *es;
287 uint32_t fc, frc, fi;
289 es = ext_get_super(pr, &fc, &fi, &frc);
291 return errno ? -errno : 1;
293 /* Distinguish from jbd */
294 if (fi & EXT3_FEATURE_INCOMPAT_JOURNAL_DEV)
297 /* Ext4 has at least one feature which ext3 doesn't understand */
298 if (!(frc & EXT3_FEATURE_RO_COMPAT_UNSUPPORTED) &&
299 !(fi & EXT3_FEATURE_INCOMPAT_UNSUPPORTED))
303 * If the filesystem is a OK for use by in-development
304 * filesystem code, and ext4dev is supported or ext4 is not
305 * supported, then don't call ourselves ext4, so we can redo
306 * the detection and mark the filesystem as ext4dev.
308 * If the filesystem is marked as in use by production
309 * filesystem, then it can only be used by ext4 and NOT by
312 if (le32_to_cpu(es->s_flags) & EXT2_FLAGS_TEST_FILESYS)
315 ext_get_info(pr, 4, es);
319 #define BLKID_EXT_MAGICS \
322 .magic = EXT_SB_MAGIC, \
323 .len = sizeof(EXT_SB_MAGIC) - 1, \
324 .kboff = EXT_SB_KBOFF, \
325 .sboff = EXT_MAG_OFF \
330 const struct blkid_idinfo jbd_idinfo =
333 .usage = BLKID_USAGE_OTHER,
334 .probefunc = probe_jbd,
335 .magics = BLKID_EXT_MAGICS
338 const struct blkid_idinfo ext2_idinfo =
341 .usage = BLKID_USAGE_FILESYSTEM,
342 .probefunc = probe_ext2,
343 .magics = BLKID_EXT_MAGICS
346 const struct blkid_idinfo ext3_idinfo =
349 .usage = BLKID_USAGE_FILESYSTEM,
350 .probefunc = probe_ext3,
351 .magics = BLKID_EXT_MAGICS
354 const struct blkid_idinfo ext4_idinfo =
357 .usage = BLKID_USAGE_FILESYSTEM,
358 .probefunc = probe_ext4,
359 .magics = BLKID_EXT_MAGICS
362 const struct blkid_idinfo ext4dev_idinfo =
365 .usage = BLKID_USAGE_FILESYSTEM,
366 .probefunc = probe_ext4dev,
367 .magics = BLKID_EXT_MAGICS