util-linux/volume_id/ocfs2.c

   1 /*
   2  * volume_id - reads filesystem label and uuid
   3  *
   4  * Copyright (C) Andre Masella <andre@masella.no-ip.org>
   5  *
   6  *      This library is free software; you can redistribute it and/or
   7  *      modify it under the terms of the GNU Lesser General Public
   8  *      License as published by the Free Software Foundation; either
   9  *      version 2.1 of the License, or (at your option) any later version.
  10  *
  11  *      This library is distributed in the hope that it will be useful,
  12  *      but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14  *      Lesser General Public License for more details.
  15  *
  16  *      You should have received a copy of the GNU Lesser General Public
  17  *      License along with this library; if not, write to the Free Software
  18  *      Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  19  */
  20
  21 //kbuild:lib-$(CONFIG_FEATURE_VOLUMEID_OCFS2) += ocfs2.o
  22
  23 //config:
  24 //config:config FEATURE_VOLUMEID_OCFS2
  25 //config:       bool "ocfs2 filesystem"
  26 //config:       default y
  27 //config:       depends on VOLUMEID
  28 //config:       help
  29 //config:         TODO
  30 //config:
  31
  32 #include "volume_id_internal.h"
  33
  34 /* All these values are taken from ocfs2-tools's ocfs2_fs.h */
  35 #define OCFS2_VOL_UUID_LEN                      16
  36 #define OCFS2_MAX_VOL_LABEL_LEN                 64
  37 #define OCFS2_SUPERBLOCK_OFFSET                 0x2000
  38
  39
  40 /* This is the superblock. The OCFS2 header files have structs in structs.
  41 This is one has been simplified since we only care about the superblock.
  42 */
  43
  44 struct ocfs2_super_block {
  45         uint8_t         i_signature[8];                 /* Signature for validation */
  46         uint32_t        i_generation;                   /* Generation number */
  47         int16_t         i_suballoc_slot;                        /* Slot suballocator this inode belongs to */
  48         uint16_t        i_suballoc_bit;                 /* Bit offset in suballocator block group */
  49         uint32_t        i_reserved0;
  50         uint32_t        i_clusters;                     /* Cluster count */
  51         uint32_t        i_uid;                          /* Owner UID */
  52         uint32_t        i_gid;                          /* Owning GID */
  53         uint64_t        i_size;                         /* Size in bytes */
  54         uint16_t        i_mode;                         /* File mode */
  55         uint16_t        i_links_count;                  /* Links count */
  56         uint32_t        i_flags;                                /* File flags */
  57         uint64_t        i_atime;                                /* Access time */
  58         uint64_t        i_ctime;                                /* Creation time */
  59         uint64_t        i_mtime;                                /* Modification time */
  60         uint64_t        i_dtime;                                /* Deletion time */
  61         uint64_t        i_blkno;                                /* Offset on disk, in blocks */
  62         uint64_t        i_last_eb_blk;                  /* Pointer to last extent block */
  63         uint32_t        i_fs_generation;                        /* Generation per fs-instance */
  64         uint32_t        i_atime_nsec;
  65         uint32_t        i_ctime_nsec;
  66         uint32_t        i_mtime_nsec;
  67         uint64_t        i_reserved1[9];
  68         uint64_t        i_pad1;                         /* Generic way to refer to this 64bit union */
  69         /* Normally there is a union of the different block types, but we only care about the superblock. */
  70         uint16_t        s_major_rev_level;
  71         uint16_t        s_minor_rev_level;
  72         uint16_t        s_mnt_count;
  73         int16_t         s_max_mnt_count;
  74         uint16_t        s_state;                                /* File system state */
  75         uint16_t        s_errors;                               /* Behaviour when detecting errors */
  76         uint32_t        s_checkinterval;                        /* Max time between checks */
  77         uint64_t        s_lastcheck;                    /* Time of last check */
  78         uint32_t        s_creator_os;                   /* OS */
  79         uint32_t        s_feature_compat;                       /* Compatible feature set */
  80         uint32_t        s_feature_incompat;             /* Incompatible feature set */
  81         uint32_t        s_feature_ro_compat;            /* Readonly-compatible feature set */
  82         uint64_t        s_root_blkno;                   /* Offset, in blocks, of root directory dinode */
  83         uint64_t        s_system_dir_blkno;             /* Offset, in blocks, of system directory dinode */
  84         uint32_t        s_blocksize_bits;                       /* Blocksize for this fs */
  85         uint32_t        s_clustersize_bits;             /* Clustersize for this fs */
  86         uint16_t        s_max_slots;                    /* Max number of simultaneous mounts before tunefs required */
  87         uint16_t        s_reserved1;
  88         uint32_t        s_reserved2;
  89         uint64_t        s_first_cluster_group;          /* Block offset of 1st cluster group header */
  90         uint8_t         s_label[OCFS2_MAX_VOL_LABEL_LEN];       /* Label for mounting, etc. */
  91         uint8_t         s_uuid[OCFS2_VOL_UUID_LEN];     /* 128-bit uuid */
  92 } PACKED;
  93
  94 int FAST_FUNC volume_id_probe_ocfs2(struct volume_id *id /*,uint64_t off*/)
  95 {
  96 #define off ((uint64_t)0)
  97         struct ocfs2_super_block *os;
  98
  99         dbg("probing at offset 0x%llx", (unsigned long long) off);
 100
 101         os = volume_id_get_buffer(id, off + OCFS2_SUPERBLOCK_OFFSET, 0x200);
 102         if (os == NULL)
 103                 return -1;
 104
 105         if (memcmp(os->i_signature, "OCFSV2", 6) != 0) {
 106                 return -1;
 107         }
 108
 109 //      volume_id_set_usage(id, VOLUME_ID_FILESYSTEM);
 110 //      volume_id_set_label_raw(id, os->s_label, OCFS2_MAX_VOL_LABEL_LEN < VOLUME_ID_LABEL_SIZE ?
 111 //                                      OCFS2_MAX_VOL_LABEL_LEN : VOLUME_ID_LABEL_SIZE);
 112         volume_id_set_label_string(id, os->s_label, OCFS2_MAX_VOL_LABEL_LEN < VOLUME_ID_LABEL_SIZE ?
 113                                         OCFS2_MAX_VOL_LABEL_LEN : VOLUME_ID_LABEL_SIZE);
 114         volume_id_set_uuid(id, os->s_uuid, UUID_DCE);
 115         IF_FEATURE_BLKID_TYPE(id->type = "ocfs2";)
 116         return 0;
 117 }