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authorChristophe Grenier <grenier@cgsecurity.org>2007-10-29 22:38:52 +0100
committerChristophe Grenier <grenier@cgsecurity.org>2007-10-29 22:38:52 +0100
commit9928d99936105b4653d2d1b8ca74dc3ffba5c71e (patch)
tree06aa4f5e9f0055027c6fb54dd47a8414cf2fba32 /src/md.h
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+/*
+
+ File: md.h
+
+ Copyright (C) 1998-2004 Christophe GRENIER <grenier@cgsecurity.org>
+
+ This software 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 2 of the License, or
+ (at your option) any later version.
+
+ This program 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 this program; if not, write the Free Software Foundation, Inc., 51
+ Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+ */
+/*
+ physical layout of Linux RAID devices
+ Copyright (C) 1996-98 Ingo Molnar, Gadi Oxman
+*/
+
+#ifndef _MD_P_H
+#define _MD_P_H
+
+/*
+ * RAID superblock.
+ *
+ * The RAID superblock maintains some statistics on each RAID configuration.
+ * Each real device in the RAID set contains it near the end of the device.
+ * Some of the ideas are copied from the ext2fs implementation.
+ *
+ * We currently use 4096 bytes as follows:
+ *
+ * word offset function
+ *
+ * 0 - 31 Constant generic RAID device information.
+ * 32 - 63 Generic state information.
+ * 64 - 127 Personality specific information.
+ * 128 - 511 12 32-words descriptors of the disks in the raid set.
+ * 512 - 911 Reserved.
+ * 912 - 1023 Disk specific descriptor.
+ */
+
+/*
+ * If x is the real device size in bytes, we return an apparent size of:
+ *
+ * y = (x & ~(MD_RESERVED_BYTES - 1)) - MD_RESERVED_BYTES
+ *
+ * and place the 4kB superblock at offset y.
+ */
+#define MD_MAX_CHUNK_SIZE (4096*1024)
+#define MD_RESERVED_BYTES (64 * 1024)
+#define MD_RESERVED_SECTORS (MD_RESERVED_BYTES / 512)
+#define MD_RESERVED_BLOCKS (MD_RESERVED_BYTES / BLOCK_SIZE)
+
+#define MD_NEW_SIZE_SECTORS(x) ((x & ~(MD_RESERVED_SECTORS - 1)) - MD_RESERVED_SECTORS)
+#define MD_NEW_SIZE_BLOCKS(x) ((x & ~(MD_RESERVED_BLOCKS - 1)) - MD_RESERVED_BLOCKS)
+
+#define MD_SB_BYTES 4096
+#define MD_SB_WORDS (MD_SB_BYTES / 4)
+#define MD_SB_BLOCKS (MD_SB_BYTES / BLOCK_SIZE)
+#define MD_SB_SECTORS (MD_SB_BYTES / 512)
+
+/*
+ * The following are counted in 32-bit words
+ */
+#define MD_SB_GENERIC_OFFSET 0
+#define MD_SB_PERSONALITY_OFFSET 64
+#define MD_SB_DISKS_OFFSET 128
+#define MD_SB_DESCRIPTOR_OFFSET 992
+
+#define MD_SB_GENERIC_CONSTANT_WORDS 32
+#define MD_SB_GENERIC_STATE_WORDS 32
+#define MD_SB_GENERIC_WORDS (MD_SB_GENERIC_CONSTANT_WORDS + MD_SB_GENERIC_STATE_WORDS)
+#define MD_SB_PERSONALITY_WORDS 64
+#define MD_SB_DESCRIPTOR_WORDS 32
+#define MD_SB_DISKS 27
+#define MD_SB_DISKS_WORDS (MD_SB_DISKS*MD_SB_DESCRIPTOR_WORDS)
+#define MD_SB_RESERVED_WORDS (1024 - MD_SB_GENERIC_WORDS - MD_SB_PERSONALITY_WORDS - MD_SB_DISKS_WORDS - MD_SB_DESCRIPTOR_WORDS)
+#define MD_SB_EQUAL_WORDS (MD_SB_GENERIC_WORDS + MD_SB_PERSONALITY_WORDS + MD_SB_DISKS_WORDS)
+
+/*
+ * Device "operational" state bits
+ */
+#define MD_DISK_FAULTY 0 /* disk is faulty / operational */
+#define MD_DISK_ACTIVE 1 /* disk is running or spare disk */
+#define MD_DISK_SYNC 2 /* disk is in sync with the raid set */
+#define MD_DISK_REMOVED 3 /* disk is in sync with the raid set */
+
+typedef struct mdp_device_descriptor_s {
+ uint32_t number; /* 0 Device number in the entire set */
+ uint32_t major; /* 1 Device major number */
+ uint32_t minor; /* 2 Device minor number */
+ uint32_t raid_disk; /* 3 The role of the device in the raid set */
+ uint32_t state; /* 4 Operational state */
+ uint32_t reserved[MD_SB_DESCRIPTOR_WORDS - 5];
+} mdp_disk_t;
+
+#define MD_SB_MAGIC 0xa92b4efc
+
+/*
+ * Superblock state bits
+ */
+#define MD_SB_CLEAN 0
+#define MD_SB_ERRORS 1
+
+typedef struct mdp_superblock_s {
+ /*
+ * Constant generic information
+ */
+ uint32_t md_magic; /* 0 MD identifier */
+ uint32_t major_version; /* 1 major version to which the set conforms */
+ uint32_t minor_version; /* 2 minor version ... */
+ uint32_t patch_version; /* 3 patchlevel version ... */
+ uint32_t gvalid_words; /* 4 Number of used words in this section */
+ uint32_t set_uuid0; /* 5 Raid set identifier */
+ uint32_t ctime; /* 6 Creation time */
+ uint32_t level; /* 7 Raid personality */
+ uint32_t size; /* 8 Apparent size of each individual disk */
+ uint32_t nr_disks; /* 9 total disks in the raid set */
+ uint32_t raid_disks; /* 10 disks in a fully functional raid set */
+ uint32_t md_minor; /* 11 preferred MD minor device number */
+ uint32_t not_persistent; /* 12 does it have a persistent superblock */
+ uint32_t set_uuid1; /* 13 Raid set identifier #2 */
+ uint32_t set_uuid2; /* 14 Raid set identifier #3 */
+ uint32_t set_uuid3; /* 15 Raid set identifier #4 */
+ uint32_t gstate_creserved[MD_SB_GENERIC_CONSTANT_WORDS - 16];
+
+ /*
+ * Generic state information
+ */
+ uint32_t utime; /* 0 Superblock update time */
+ uint32_t state; /* 1 State bits (clean, ...) */
+ uint32_t active_disks; /* 2 Number of currently active disks */
+ uint32_t working_disks; /* 3 Number of working disks */
+ uint32_t failed_disks; /* 4 Number of failed disks */
+ uint32_t spare_disks; /* 5 Number of spare disks */
+ uint32_t sb_csum; /* 6 checksum of the whole superblock */
+#ifdef __BIG_ENDIAN
+ uint32_t events_hi; /* 7 high-order of superblock update count */
+ uint32_t events_lo; /* 8 low-order of superblock update count */
+#else
+ uint32_t events_lo; /* 7 low-order of superblock update count */
+ uint32_t events_hi; /* 8 high-order of superblock update count */
+#endif
+ uint32_t gstate_sreserved[MD_SB_GENERIC_STATE_WORDS - 9];
+
+ /*
+ * Personality information
+ */
+ uint32_t layout; /* 0 the array's physical layout */
+ uint32_t chunk_size; /* 1 chunk size in bytes */
+ uint32_t root_pv; /* 2 LV root PV */
+ uint32_t root_block; /* 3 LV root block */
+ uint32_t pstate_reserved[MD_SB_PERSONALITY_WORDS - 4];
+
+ /*
+ * Disks information
+ */
+ mdp_disk_t disks[MD_SB_DISKS];
+
+ /*
+ * Reserved
+ */
+ uint32_t reserved[MD_SB_RESERVED_WORDS];
+
+ /*
+ * Active descriptor
+ */
+ mdp_disk_t this_disk;
+
+} mdp_super_t;
+
+/*
+ * The version-1 superblock :
+ * All numeric fields are little-endian.
+ *
+ * total size: 256 bytes plus 2 per device.
+ * 1K allows 384 devices.
+ */
+struct mdp_superblock_1 {
+ /* constant array information - 128 bytes */
+ uint32_t md_magic; /* MD_SB_MAGIC: 0xa92b4efc - little endian */
+ uint32_t major_version; /* 1 */
+ uint32_t feature_map; /* bit 0 set if 'bitmap_offset' is meaningful */
+ uint32_t pad0; /* always set to 0 when writing */
+
+ uint8_t set_uuid[16]; /* user-space generated. */
+ char set_name[32]; /* set and interpreted by user-space */
+
+ uint64_t ctime; /* lo 40 bits are seconds, top 24 are microseconds or 0*/
+ uint32_t level; /* -4 (multipath), -1 (linear), 0,1,4,5 */
+ uint32_t layout; /* only for raid5 and raid10 currently */
+ uint64_t size; /* used size of component devices, in 512byte sectors */
+
+ uint32_t chunksize; /* in 512byte sectors */
+ uint32_t raid_disks;
+ int32_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' */
+ uint32_t new_level; /* new level we are reshaping to */
+ uint64_t reshape_position; /* next address in array-space for reshape */
+ uint32_t delta_disks; /* change in number of raid_disks */
+ uint32_t new_layout; /* new layout */
+ uint32_t new_chunk; /* new chunk size (bytes) */
+ uint8_t pad1[128-124]; /* set to 0 when written */
+
+ /* constant this-device information - 64 bytes */
+ uint64_t data_offset; /* sector start of data, often 0 */
+ uint64_t data_size; /* sectors in this device that can be used for data */
+ uint64_t super_offset; /* sector start of this superblock */
+ uint64_t recovery_offset;/* sectors before this offset (from data_offset) have been recovered */
+ uint32_t dev_number; /* permanent identifier of this device - not role in raid */
+ uint32_t cnt_corrected_read; /* number of read errors that were corrected by re-writing */
+ uint8_t device_uuid[16]; /* user-space setable, ignored by kernel */
+ uint8_t devflags; /* per-device flags. Only one defined...*/
+#define WriteMostly1 1 /* mask for writemostly flag in above */
+ uint8_t pad2[64-57]; /* set to 0 when writing */
+
+ /* array state information - 64 bytes */
+ uint64_t utime; /* 40 bits second, 24 btes microseconds */
+ uint64_t events; /* incremented when superblock updated */
+ uint64_t resync_offset; /* data before this offset (from data_offset) known to be in sync */
+ uint32_t sb_csum; /* checksum upto devs[max_dev] */
+ uint32_t max_dev; /* size of devs[] array to consider */
+ 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.
+ */
+ uint16_t dev_roles[0]; /* role in array, or 0xffff for a spare, or 0xfffe for faulty */
+} mdp_super1_t;
+
+static inline uint64_t md_event(mdp_super_t *sb) {
+ uint64_t ev = sb->events_hi;
+ return (ev<<32)| sb->events_lo;
+}
+
+/* TestDisk */
+int check_MD(disk_t *disk_car,partition_t *partition,const int verbose);
+int test_MD(disk_t *disk_car, const struct mdp_superblock_s *sb, partition_t *partition, const int verbose, const int dump_ind);
+int recover_MD(disk_t *disk_car, const struct mdp_superblock_s *sb, partition_t *partition, const int verbose, const int dump_ind);
+int recover_MD_from_partition(disk_t *disk_car, partition_t *partition, const int verbose);
+int set_MD_info(disk_t *disk_car, const struct mdp_superblock_s *sb,partition_t *partition,const int verbose, const int dump_ind);
+#endif
+