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 //config:config FEATURE_VOLUMEID_OCFS2
  21 //config:       bool "ocfs2 filesystem"
  22 //config:       default y
  23 //config:       depends on VOLUMEID
  24
  25 //kbuild:lib-$(CONFIG_FEATURE_VOLUMEID_OCFS2) += ocfs2.o
  26
  27 #include "volume_id_internal.h"
  28
  29 /* All these values are taken from ocfs2-tools's ocfs2_fs.h */
  30 #define OCFS2_VOL_UUID_LEN                      16
  31 #define OCFS2_MAX_VOL_LABEL_LEN                 64
  32 #define OCFS2_SUPERBLOCK_OFFSET                 0x2000
  33
  34
  35 /* This is the superblock. The OCFS2 header files have structs in structs.
  36 This is one has been simplified since we only care about the superblock.
  37 */
  38
  39 struct ocfs2_super_block {
  40         uint8_t         i_signature[8];                 /* Signature for validation */
  41         uint32_t        i_generation;                   /* Generation number */
  42         int16_t         i_suballoc_slot;                        /* Slot suballocator this inode belongs to */
  43         uint16_t        i_suballoc_bit;                 /* Bit offset in suballocator block group */
  44         uint32_t        i_reserved0;
  45         uint32_t        i_clusters;                     /* Cluster count */
  46         uint32_t        i_uid;                          /* Owner UID */
  47         uint32_t        i_gid;                          /* Owning GID */
  48         uint64_t        i_size;                         /* Size in bytes */
  49         uint16_t        i_mode;                         /* File mode */
  50         uint16_t        i_links_count;                  /* Links count */
  51         uint32_t        i_flags;                                /* File flags */
  52         uint64_t        i_atime;                                /* Access time */
  53         uint64_t        i_ctime;                                /* Creation time */
  54         uint64_t        i_mtime;                                /* Modification time */
  55         uint64_t        i_dtime;                                /* Deletion time */
  56         uint64_t        i_blkno;                                /* Offset on disk, in blocks */
  57         uint64_t        i_last_eb_blk;                  /* Pointer to last extent block */
  58         uint32_t        i_fs_generation;                        /* Generation per fs-instance */
  59         uint32_t        i_atime_nsec;
  60         uint32_t        i_ctime_nsec;
  61         uint32_t        i_mtime_nsec;
  62         uint64_t        i_reserved1[9];
  63         uint64_t        i_pad1;                         /* Generic way to refer to this 64bit union */
  64         /* Normally there is a union of the different block types, but we only care about the superblock. */
  65         uint16_t        s_major_rev_level;
  66         uint16_t        s_minor_rev_level;
  67         uint16_t        s_mnt_count;
  68         int16_t         s_max_mnt_count;
  69         uint16_t        s_state;                                /* File system state */
  70         uint16_t        s_errors;                               /* Behaviour when detecting errors */
  71         uint32_t        s_checkinterval;                        /* Max time between checks */
  72         uint64_t        s_lastcheck;                    /* Time of last check */
  73         uint32_t        s_creator_os;                   /* OS */
  74         uint32_t        s_feature_compat;                       /* Compatible feature set */
  75         uint32_t        s_feature_incompat;             /* Incompatible feature set */
  76         uint32_t        s_feature_ro_compat;            /* Readonly-compatible feature set */
  77         uint64_t        s_root_blkno;                   /* Offset, in blocks, of root directory dinode */
  78         uint64_t        s_system_dir_blkno;             /* Offset, in blocks, of system directory dinode */
  79         uint32_t        s_blocksize_bits;                       /* Blocksize for this fs */
  80         uint32_t        s_clustersize_bits;             /* Clustersize for this fs */
  81         uint16_t        s_max_slots;                    /* Max number of simultaneous mounts before tunefs required */
  82         uint16_t        s_reserved1;
  83         uint32_t        s_reserved2;
  84         uint64_t        s_first_cluster_group;          /* Block offset of 1st cluster group header */
  85         uint8_t         s_label[OCFS2_MAX_VOL_LABEL_LEN];       /* Label for mounting, etc. */
  86         uint8_t         s_uuid[OCFS2_VOL_UUID_LEN];     /* 128-bit uuid */
  87 } PACKED;
  88
  89 int FAST_FUNC volume_id_probe_ocfs2(struct volume_id *id /*,uint64_t off*/)
  90 {
  91 #define off ((uint64_t)0)
  92         struct ocfs2_super_block *os;
  93
  94         dbg("probing at offset 0x%llx", (unsigned long long) off);
  95
  96         os = volume_id_get_buffer(id, off + OCFS2_SUPERBLOCK_OFFSET, 0x200);
  97         if (os == NULL)
  98                 return -1;
  99
 100         if (memcmp(os->i_signature, "OCFSV2", 6) != 0) {
 101                 return -1;
 102         }
 103
 104 //      volume_id_set_usage(id, VOLUME_ID_FILESYSTEM);
 105 //      volume_id_set_label_raw(id, os->s_label, OCFS2_MAX_VOL_LABEL_LEN < VOLUME_ID_LABEL_SIZE ?
 106 //                                      OCFS2_MAX_VOL_LABEL_LEN : VOLUME_ID_LABEL_SIZE);
 107         volume_id_set_label_string(id, os->s_label, OCFS2_MAX_VOL_LABEL_LEN < VOLUME_ID_LABEL_SIZE ?
 108                                         OCFS2_MAX_VOL_LABEL_LEN : VOLUME_ID_LABEL_SIZE);
 109         volume_id_set_uuid(id, os->s_uuid, UUID_DCE);
 110         IF_FEATURE_BLKID_TYPE(id->type = "ocfs2";)
 111         return 0;
 112 }