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Diffstat (limited to '')
| -rw-r--r-- | libblkid/src/superblocks/linux_raid.c | 267 |
1 files changed, 267 insertions, 0 deletions
diff --git a/libblkid/src/superblocks/linux_raid.c b/libblkid/src/superblocks/linux_raid.c new file mode 100644 index 0000000..4388e56 --- /dev/null +++ b/libblkid/src/superblocks/linux_raid.c @@ -0,0 +1,267 @@ +/* + * Copyright (C) 2008 Karel Zak <kzak@redhat.com> + * + * Inspired by libvolume_id by + * Kay Sievers <kay.sievers@vrfy.org> + * + * This file may be redistributed under the terms of the + * GNU Lesser General Public License. + */ +#include <stdio.h> +#include <stdlib.h> +#include <unistd.h> +#include <string.h> +#include <stdint.h> + +#include "superblocks.h" + +struct mdp0_super_block { + uint32_t md_magic; + uint32_t major_version; + uint32_t minor_version; + uint32_t patch_version; + uint32_t gvalid_words; + uint32_t set_uuid0; + uint32_t ctime; + uint32_t level; + uint32_t size; + uint32_t nr_disks; + uint32_t raid_disks; + uint32_t md_minor; + uint32_t not_persistent; + uint32_t set_uuid1; + uint32_t set_uuid2; + uint32_t set_uuid3; +}; + +/* + * Version-1, little-endian. + */ +struct mdp1_super_block { + /* constant array information - 128 bytes */ + uint32_t magic; /* MD_SB_MAGIC: 0xa92b4efc - little endian */ + uint32_t major_version; /* 1 */ + uint32_t feature_map; /* 0 for now */ + uint32_t pad0; /* always set to 0 when writing */ + + uint8_t set_uuid[16]; /* user-space generated. */ + unsigned 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 currently */ + uint64_t size; /* used size of component devices, in 512byte sectors */ + + uint32_t chunksize; /* in 512byte sectors */ + uint32_t raid_disks; + 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' */ + 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...*/ + uint8_t pad2[64-57]; /* set to 0 when writing */ + + /* array state information - 64 bytes */ + uint64_t utime; /* 40 bits second, 24 bits 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 up to dev_roles[max_dev] */ + uint32_t max_dev; /* size of dev_roles[] 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 */ +}; + + +#define MD_RESERVED_BYTES 0x10000 +#define MD_SB_MAGIC 0xa92b4efc + +static int probe_raid0(blkid_probe pr, uint64_t off) +{ + struct mdp0_super_block *mdp0; + union { + uint32_t ints[4]; + uint8_t bytes[16]; + } uuid; + uint32_t ma, mi, pa; + uint64_t size; + + if (pr->size < MD_RESERVED_BYTES) + return 1; + mdp0 = (struct mdp0_super_block *) + blkid_probe_get_buffer(pr, + off, + sizeof(struct mdp0_super_block)); + if (!mdp0) + return errno ? -errno : 1; + + memset(uuid.ints, 0, sizeof(uuid.ints)); + + if (le32_to_cpu(mdp0->md_magic) == MD_SB_MAGIC) { + uuid.ints[0] = swab32(mdp0->set_uuid0); + if (le32_to_cpu(mdp0->minor_version) >= 90) { + uuid.ints[1] = swab32(mdp0->set_uuid1); + uuid.ints[2] = swab32(mdp0->set_uuid2); + uuid.ints[3] = swab32(mdp0->set_uuid3); + } + ma = le32_to_cpu(mdp0->major_version); + mi = le32_to_cpu(mdp0->minor_version); + pa = le32_to_cpu(mdp0->patch_version); + size = le32_to_cpu(mdp0->size); + + } else if (be32_to_cpu(mdp0->md_magic) == MD_SB_MAGIC) { + uuid.ints[0] = mdp0->set_uuid0; + if (be32_to_cpu(mdp0->minor_version) >= 90) { + uuid.ints[1] = mdp0->set_uuid1; + uuid.ints[2] = mdp0->set_uuid2; + uuid.ints[3] = mdp0->set_uuid3; + } + ma = be32_to_cpu(mdp0->major_version); + mi = be32_to_cpu(mdp0->minor_version); + pa = be32_to_cpu(mdp0->patch_version); + size = be32_to_cpu(mdp0->size); + } else + return 1; + + size <<= 10; /* convert KiB to bytes */ + + if (pr->size < size + MD_RESERVED_BYTES) + /* device is too small */ + return 1; + + if (off < size) + /* no space before superblock */ + return 1; + + /* + * Check for collisions between RAID and partition table + * + * For example the superblock is at the end of the last partition, it's + * the same position as at the end of the disk... + */ + if ((S_ISREG(pr->mode) || blkid_probe_is_wholedisk(pr)) && + blkid_probe_is_covered_by_pt(pr, + off - size, /* min. start */ + size + MD_RESERVED_BYTES)) { /* min. length */ + + /* ignore this superblock, it's within any partition and + * we are working with whole-disk now */ + return 1; + } + + if (blkid_probe_sprintf_version(pr, "%u.%u.%u", ma, mi, pa) != 0) + return 1; + if (blkid_probe_set_uuid(pr, (unsigned char *) uuid.bytes) != 0) + return 1; + if (blkid_probe_set_magic(pr, off, sizeof(mdp0->md_magic), + (unsigned char *) &mdp0->md_magic)) + return 1; + return 0; +} + +static int probe_raid1(blkid_probe pr, off_t off) +{ + struct mdp1_super_block *mdp1; + + mdp1 = (struct mdp1_super_block *) + blkid_probe_get_buffer(pr, + off, + sizeof(struct mdp1_super_block)); + if (!mdp1) + return errno ? -errno : 1; + if (le32_to_cpu(mdp1->magic) != MD_SB_MAGIC) + return 1; + if (le32_to_cpu(mdp1->major_version) != 1U) + return 1; + if (le64_to_cpu(mdp1->super_offset) != (uint64_t) off >> 9) + return 1; + if (blkid_probe_set_uuid(pr, (unsigned char *) mdp1->set_uuid) != 0) + return 1; + if (blkid_probe_set_uuid_as(pr, + (unsigned char *) mdp1->device_uuid, "UUID_SUB") != 0) + return 1; + if (blkid_probe_set_label(pr, mdp1->set_name, + sizeof(mdp1->set_name)) != 0) + return 1; + if (blkid_probe_set_magic(pr, off, sizeof(mdp1->magic), + (unsigned char *) &mdp1->magic)) + return 1; + return 0; +} + +static int probe_raid(blkid_probe pr, + const struct blkid_idmag *mag __attribute__((__unused__))) +{ + const char *ver = NULL; + int ret = BLKID_PROBE_NONE; + + if (pr->size > MD_RESERVED_BYTES) { + /* version 0 at the end of the device */ + uint64_t sboff = (pr->size & ~(MD_RESERVED_BYTES - 1)) + - MD_RESERVED_BYTES; + ret = probe_raid0(pr, sboff); + if (ret < 1) + return ret; /* error */ + + /* version 1.0 at the end of the device */ + sboff = (pr->size & ~(0x1000 - 1)) - 0x2000; + ret = probe_raid1(pr, sboff); + if (ret < 0) + return ret; /* error */ + if (ret == 0) + ver = "1.0"; + } + + if (!ver) { + /* version 1.1 at the start of the device */ + ret = probe_raid1(pr, 0); + if (ret == 0) + ver = "1.1"; + + /* version 1.2 at 4k offset from the start */ + else if (ret == BLKID_PROBE_NONE) { + ret = probe_raid1(pr, 0x1000); + if (ret == 0) + ver = "1.2"; + } + } + + if (ver) { + blkid_probe_set_version(pr, ver); + return BLKID_PROBE_OK; + } + return ret; +} + + +const struct blkid_idinfo linuxraid_idinfo = { + .name = "linux_raid_member", + .usage = BLKID_USAGE_RAID, + .probefunc = probe_raid, + .magics = BLKID_NONE_MAGIC +}; + + |