ocfs2_fs.h

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/* -*- mode: c; c-basic-offset: 8; -*-
 * vim: noexpandtab sw=8 ts=8 sts=0:
 *
 * ocfs2_fs.h
 *
 * On-disk structures for OCFS2.
 *
 * Copyright (C) 2002, 2004 Oracle.  All rights reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public
 * License, version 2,  as published by the Free Software Foundation.
 *
 * 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 to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 021110-1307, USA.
 */

#ifndef _OCFS2_FS_H
#define _OCFS2_FS_H

/* Version */
#define OCFS2_MAJOR_REV_LEVEL       0
#define OCFS2_MINOR_REV_LEVEL           90

/*
 * An OCFS2 volume starts this way:
 * Sector 0: Valid ocfs1_vol_disk_hdr that cleanly fails to mount OCFS.
 * Sector 1: Valid ocfs1_vol_label that cleanly fails to mount OCFS.
 * Block OCFS2_SUPER_BLOCK_BLKNO: OCFS2 superblock.
 *
 * All other structures are found from the superblock information.
 *
 * OCFS2_SUPER_BLOCK_BLKNO is in blocks, not sectors.  eg, for a
 * blocksize of 2K, it is 4096 bytes into disk.
 */
#define OCFS2_SUPER_BLOCK_BLKNO     2

/*
 * Cluster size limits. The maximum is kept arbitrarily at 1 MB, and could
 * grow if needed.
 */
#define OCFS2_MIN_CLUSTERSIZE       4096
#define OCFS2_MAX_CLUSTERSIZE       1048576

/*
 * Blocks cannot be bigger than clusters, so the maximum blocksize is the
 * minimum cluster size.
 */
#define OCFS2_MIN_BLOCKSIZE     512
#define OCFS2_MAX_BLOCKSIZE     OCFS2_MIN_CLUSTERSIZE

/* Filesystem magic number */
#define OCFS2_SUPER_MAGIC       0x7461636f

/* Object signatures */
#define OCFS2_SUPER_BLOCK_SIGNATURE "OCFSV2"
#define OCFS2_INODE_SIGNATURE       "INODE01"
#define OCFS2_EXTENT_BLOCK_SIGNATURE    "EXBLK01"
#define OCFS2_GROUP_DESC_SIGNATURE      "GROUP01"
#define OCFS2_XATTR_BLOCK_SIGNATURE "XATTR01"
#define OCFS2_DIR_TRAILER_SIGNATURE "DIRTRL1"
#define OCFS2_DX_ROOT_SIGNATURE     "DXDIR01"
#define OCFS2_DX_LEAF_SIGNATURE     "DXLEAF1"
#define OCFS2_REFCOUNT_BLOCK_SIGNATURE  "REFCNT1"

/* Compatibility flags */
#define OCFS2_HAS_COMPAT_FEATURE(sb,mask)           \
    ( OCFS2_SB(sb)->s_feature_compat & (mask) )
#define OCFS2_HAS_RO_COMPAT_FEATURE(sb,mask)            \
    ( OCFS2_SB(sb)->s_feature_ro_compat & (mask) )
#define OCFS2_HAS_INCOMPAT_FEATURE(sb,mask)         \
    ( OCFS2_SB(sb)->s_feature_incompat & (mask) )
#define OCFS2_SET_COMPAT_FEATURE(sb,mask)           \
    OCFS2_SB(sb)->s_feature_compat |= (mask)
#define OCFS2_SET_RO_COMPAT_FEATURE(sb,mask)            \
    OCFS2_SB(sb)->s_feature_ro_compat |= (mask)
#define OCFS2_SET_INCOMPAT_FEATURE(sb,mask)         \
    OCFS2_SB(sb)->s_feature_incompat |= (mask)
#define OCFS2_CLEAR_COMPAT_FEATURE(sb,mask)         \
    OCFS2_SB(sb)->s_feature_compat &= ~(mask)
#define OCFS2_CLEAR_RO_COMPAT_FEATURE(sb,mask)          \
    OCFS2_SB(sb)->s_feature_ro_compat &= ~(mask)
#define OCFS2_CLEAR_INCOMPAT_FEATURE(sb,mask)           \
    OCFS2_SB(sb)->s_feature_incompat &= ~(mask)

#define OCFS2_FEATURE_COMPAT_SUPP   (OCFS2_FEATURE_COMPAT_BACKUP_SB \
                     | OCFS2_FEATURE_COMPAT_JBD2_SB)
#define OCFS2_FEATURE_INCOMPAT_SUPP (OCFS2_FEATURE_INCOMPAT_LOCAL_MOUNT \
                     | OCFS2_FEATURE_INCOMPAT_SPARSE_ALLOC \
                     | OCFS2_FEATURE_INCOMPAT_INLINE_DATA \
                     | OCFS2_FEATURE_INCOMPAT_EXTENDED_SLOT_MAP \
                     | OCFS2_FEATURE_INCOMPAT_USERSPACE_STACK \
                     | OCFS2_FEATURE_INCOMPAT_XATTR \
                     | OCFS2_FEATURE_INCOMPAT_META_ECC \
                     | OCFS2_FEATURE_INCOMPAT_INDEXED_DIRS \
                     | OCFS2_FEATURE_INCOMPAT_REFCOUNT_TREE \
                     | OCFS2_FEATURE_INCOMPAT_DISCONTIG_BG  \
                     | OCFS2_FEATURE_INCOMPAT_CLUSTERINFO)
#define OCFS2_FEATURE_RO_COMPAT_SUPP    (OCFS2_FEATURE_RO_COMPAT_UNWRITTEN \
                     | OCFS2_FEATURE_RO_COMPAT_USRQUOTA \
                     | OCFS2_FEATURE_RO_COMPAT_GRPQUOTA)

/*
 * Heartbeat-only devices are missing journals and other files.  The
 * filesystem driver can't load them, but the library can.  Never put
 * this in OCFS2_FEATURE_INCOMPAT_SUPP, *ever*.
 */
#define OCFS2_FEATURE_INCOMPAT_HEARTBEAT_DEV    0x0002

/*
 * tunefs sets this incompat flag before starting the resize and clears it
 * at the end. This flag protects users from inadvertently mounting the fs
 * after an aborted run without fsck-ing.
 */
#define OCFS2_FEATURE_INCOMPAT_RESIZE_INPROG    0x0004

/* Used to denote a non-clustered volume */
#define OCFS2_FEATURE_INCOMPAT_LOCAL_MOUNT  0x0008

/* Support for sparse allocation in b-trees */
#define OCFS2_FEATURE_INCOMPAT_SPARSE_ALLOC 0x0010

/*
 * Tunefs sets this incompat flag before starting an operation which
 * would require cleanup on abort. This is done to protect users from
 * inadvertently mounting the fs after an aborted run without
 * fsck-ing.
 *
 * s_tunefs_flags on the super block describes precisely which
 * operations were in progress.
 */
#define OCFS2_FEATURE_INCOMPAT_TUNEFS_INPROG    0x0020

/* Support for data packed into inode blocks */
#define OCFS2_FEATURE_INCOMPAT_INLINE_DATA  0x0040

/*
 * Support for alternate, userspace cluster stacks.  If set, the superblock
 * field s_cluster_info contains a tag for the alternate stack in use as
 * well as the name of the cluster being joined.
 * mount.ocfs2 must pass in a matching stack name.
 *
 * If not set, the classic stack will be used.  This is compatbile with
 * all older versions.
 */
#define OCFS2_FEATURE_INCOMPAT_USERSPACE_STACK  0x0080

/* Support for the extended slot map */
#define OCFS2_FEATURE_INCOMPAT_EXTENDED_SLOT_MAP 0x100

/* Support for extended attributes */
#define OCFS2_FEATURE_INCOMPAT_XATTR        0x0200

/* Support for indexed directores */
#define OCFS2_FEATURE_INCOMPAT_INDEXED_DIRS 0x0400

/* Metadata checksum and error correction */
#define OCFS2_FEATURE_INCOMPAT_META_ECC     0x0800

/* Refcount tree support */
#define OCFS2_FEATURE_INCOMPAT_REFCOUNT_TREE    0x1000

/* Discontigous block groups */
#define OCFS2_FEATURE_INCOMPAT_DISCONTIG_BG 0x2000

/*
 * Incompat bit to indicate useable clusterinfo with stackflags for all
 * cluster stacks (userspace adnd o2cb). If this bit is set,
 * INCOMPAT_USERSPACE_STACK becomes superfluous and thus should not be set.
 */
#define OCFS2_FEATURE_INCOMPAT_CLUSTERINFO  0x4000

/*
 * backup superblock flag is used to indicate that this volume
 * has backup superblocks.
 */
#define OCFS2_FEATURE_COMPAT_BACKUP_SB      0x0001

/*
 * The filesystem will correctly handle journal feature bits.
 */
#define OCFS2_FEATURE_COMPAT_JBD2_SB        0x0002

/*
 * Unwritten extents support.
 */
#define OCFS2_FEATURE_RO_COMPAT_UNWRITTEN   0x0001

/*
 * Maintain quota information for this filesystem
 */
#define OCFS2_FEATURE_RO_COMPAT_USRQUOTA    0x0002
#define OCFS2_FEATURE_RO_COMPAT_GRPQUOTA    0x0004

/* The byte offset of the first backup block will be 1G.
 * The following will be 4G, 16G, 64G, 256G and 1T.
 */
#define OCFS2_BACKUP_SB_START           1 << 30

/* the max backup superblock nums */
#define OCFS2_MAX_BACKUP_SUPERBLOCKS    6

/*
 * Flags on ocfs2_super_block.s_tunefs_flags
 */
#define OCFS2_TUNEFS_INPROG_REMOVE_SLOT     0x0001  /* Removing slots */

/*
 * Flags on ocfs2_dinode.i_flags
 */
#define OCFS2_VALID_FL      (0x00000001)    /* Inode is valid */
#define OCFS2_UNUSED2_FL    (0x00000002)
#define OCFS2_ORPHANED_FL   (0x00000004)    /* On the orphan list */
#define OCFS2_UNUSED3_FL    (0x00000008)
/* System inode flags */
#define OCFS2_SYSTEM_FL     (0x00000010)    /* System inode */
#define OCFS2_SUPER_BLOCK_FL    (0x00000020)    /* Super block */
#define OCFS2_LOCAL_ALLOC_FL    (0x00000040)    /* Slot local alloc bitmap */
#define OCFS2_BITMAP_FL     (0x00000080)    /* Allocation bitmap */
#define OCFS2_JOURNAL_FL    (0x00000100)    /* Slot local journal */
#define OCFS2_HEARTBEAT_FL  (0x00000200)    /* Heartbeat area */
#define OCFS2_CHAIN_FL      (0x00000400)    /* Chain allocator */
#define OCFS2_DEALLOC_FL    (0x00000800)    /* Truncate log */
#define OCFS2_QUOTA_FL      (0x00001000)    /* Quota file */

/*
 * Flags on ocfs2_dinode.i_dyn_features
 *
 * These can change much more often than i_flags. When adding flags,
 * keep in mind that i_dyn_features is only 16 bits wide.
 */
#define OCFS2_INLINE_DATA_FL    (0x0001)    /* Data stored in inode block */
#define OCFS2_HAS_XATTR_FL  (0x0002)
#define OCFS2_INLINE_XATTR_FL   (0x0004)
#define OCFS2_INDEXED_DIR_FL    (0x0008)
#define OCFS2_HAS_REFCOUNT_FL   (0x0010)

/* Inode attributes, keep in sync with EXT2 */
#define OCFS2_SECRM_FL          FS_SECRM_FL /* Secure deletion */
#define OCFS2_UNRM_FL           FS_UNRM_FL  /* Undelete */
#define OCFS2_COMPR_FL          FS_COMPR_FL /* Compress file */
#define OCFS2_SYNC_FL           FS_SYNC_FL  /* Synchronous updates */
#define OCFS2_IMMUTABLE_FL      FS_IMMUTABLE_FL /* Immutable file */
#define OCFS2_APPEND_FL         FS_APPEND_FL    /* writes to file may only append */
#define OCFS2_NODUMP_FL         FS_NODUMP_FL    /* do not dump file */
#define OCFS2_NOATIME_FL        FS_NOATIME_FL   /* do not update atime */
/* Reserved for compression usage... */
#define OCFS2_DIRTY_FL          FS_DIRTY_FL
#define OCFS2_COMPRBLK_FL       FS_COMPRBLK_FL  /* One or more compressed clusters */
#define OCFS2_NOCOMP_FL         FS_NOCOMP_FL    /* Don't compress */
#define OCFS2_ECOMPR_FL         FS_ECOMPR_FL    /* Compression error */
/* End compression flags --- maybe not all used */
#define OCFS2_BTREE_FL          FS_BTREE_FL /* btree format dir */
#define OCFS2_INDEX_FL          FS_INDEX_FL /* hash-indexed directory */
#define OCFS2_IMAGIC_FL         FS_IMAGIC_FL    /* AFS directory */
#define OCFS2_JOURNAL_DATA_FL       FS_JOURNAL_DATA_FL /* Reserved for ext3 */
#define OCFS2_NOTAIL_FL         FS_NOTAIL_FL    /* file tail should not be merged */
#define OCFS2_DIRSYNC_FL        FS_DIRSYNC_FL   /* dirsync behaviour (directories only) */
#define OCFS2_TOPDIR_FL         FS_TOPDIR_FL    /* Top of directory hierarchies*/
#define OCFS2_RESERVED_FL       FS_RESERVED_FL  /* reserved for ext2 lib */

#define OCFS2_FL_VISIBLE        FS_FL_USER_VISIBLE  /* User visible flags */
#define OCFS2_FL_MODIFIABLE     FS_FL_USER_MODIFIABLE   /* User modifiable flags */

/*
 * Extent record flags (e_node.leaf.flags)
 */
#define OCFS2_EXT_UNWRITTEN     (0x01)  /* Extent is allocated but
                         * unwritten */
#define OCFS2_EXT_REFCOUNTED        (0x02)  /* Extent is reference
                         * counted in an associated
                         * refcount tree */

/*
 * Journal Flags (ocfs2_dinode.id1.journal1.i_flags)
 */
#define OCFS2_JOURNAL_DIRTY_FL  (0x00000001)    /* Journal needs recovery */

/*
 * superblock s_state flags
 */
#define OCFS2_ERROR_FS      (0x00000001)    /* FS saw errors */

/* Limit of space in ocfs2_dir_entry */
#define OCFS2_MAX_FILENAME_LEN      255

/* Maximum slots on an ocfs2 file system */
#define OCFS2_MAX_SLOTS         255

/* Slot map indicator for an empty slot */
#define OCFS2_INVALID_SLOT      -1

#define OCFS2_VOL_UUID_LEN      16
#define OCFS2_MAX_VOL_LABEL_LEN     64

/* The cluster stack fields */
#define OCFS2_STACK_LABEL_LEN       4
#define OCFS2_CLUSTER_NAME_LEN      16

/* Classic (historically speaking) cluster stack */
#define OCFS2_CLASSIC_CLUSTER_STACK "o2cb"

/* Journal limits (in bytes) */
#define OCFS2_MIN_JOURNAL_SIZE      (4 * 1024 * 1024)

/*
 * Inline extended attribute size (in bytes)
 * The value chosen should be aligned to 16 byte boundaries.
 */
#define OCFS2_MIN_XATTR_INLINE_SIZE     256

/*
 * Cluster info flags (ocfs2_cluster_info.ci_stackflags)
 */
#define OCFS2_CLUSTER_O2CB_GLOBAL_HEARTBEAT (0x01)

struct ocfs2_system_inode_info {
    char    *si_name;
    int si_iflags;
    int si_mode;
};

/* System file index */
enum {
    BAD_BLOCK_SYSTEM_INODE = 0,
    GLOBAL_INODE_ALLOC_SYSTEM_INODE,
    SLOT_MAP_SYSTEM_INODE,
#define OCFS2_FIRST_ONLINE_SYSTEM_INODE SLOT_MAP_SYSTEM_INODE
    HEARTBEAT_SYSTEM_INODE,
    GLOBAL_BITMAP_SYSTEM_INODE,
    USER_QUOTA_SYSTEM_INODE,
    GROUP_QUOTA_SYSTEM_INODE,
#define OCFS2_LAST_GLOBAL_SYSTEM_INODE GROUP_QUOTA_SYSTEM_INODE
#define OCFS2_FIRST_LOCAL_SYSTEM_INODE ORPHAN_DIR_SYSTEM_INODE
    ORPHAN_DIR_SYSTEM_INODE,
    EXTENT_ALLOC_SYSTEM_INODE,
    INODE_ALLOC_SYSTEM_INODE,
    JOURNAL_SYSTEM_INODE,
    LOCAL_ALLOC_SYSTEM_INODE,
    TRUNCATE_LOG_SYSTEM_INODE,
    LOCAL_USER_QUOTA_SYSTEM_INODE,
    LOCAL_GROUP_QUOTA_SYSTEM_INODE,
#define OCFS2_LAST_LOCAL_SYSTEM_INODE LOCAL_GROUP_QUOTA_SYSTEM_INODE
    NUM_SYSTEM_INODES
};
#define NUM_GLOBAL_SYSTEM_INODES OCFS2_FIRST_LOCAL_SYSTEM_INODE
#define NUM_LOCAL_SYSTEM_INODES \
        (NUM_SYSTEM_INODES - OCFS2_FIRST_LOCAL_SYSTEM_INODE)

static struct ocfs2_system_inode_info ocfs2_system_inodes[NUM_SYSTEM_INODES] = {
    /* Global system inodes (single copy) */
    /* The first two are only used from userspace mfks/tunefs */
    [BAD_BLOCK_SYSTEM_INODE]        = { "bad_blocks", 0, S_IFREG | 0644 },
    [GLOBAL_INODE_ALLOC_SYSTEM_INODE]   = { "global_inode_alloc", OCFS2_BITMAP_FL | OCFS2_CHAIN_FL, S_IFREG | 0644 },

    /* These are used by the running filesystem */
    [SLOT_MAP_SYSTEM_INODE]         = { "slot_map", 0, S_IFREG | 0644 },
    [HEARTBEAT_SYSTEM_INODE]        = { "heartbeat", OCFS2_HEARTBEAT_FL, S_IFREG | 0644 },
    [GLOBAL_BITMAP_SYSTEM_INODE]        = { "global_bitmap", 0, S_IFREG | 0644 },
    [USER_QUOTA_SYSTEM_INODE]       = { "aquota.user", OCFS2_QUOTA_FL, S_IFREG | 0644 },
    [GROUP_QUOTA_SYSTEM_INODE]      = { "aquota.group", OCFS2_QUOTA_FL, S_IFREG | 0644 },

    /* Slot-specific system inodes (one copy per slot) */
    [ORPHAN_DIR_SYSTEM_INODE]       = { "orphan_dir:%04d", 0, S_IFDIR | 0755 },
    [EXTENT_ALLOC_SYSTEM_INODE]     = { "extent_alloc:%04d", OCFS2_BITMAP_FL | OCFS2_CHAIN_FL, S_IFREG | 0644 },
    [INODE_ALLOC_SYSTEM_INODE]      = { "inode_alloc:%04d", OCFS2_BITMAP_FL | OCFS2_CHAIN_FL, S_IFREG | 0644 },
    [JOURNAL_SYSTEM_INODE]          = { "journal:%04d", OCFS2_JOURNAL_FL, S_IFREG | 0644 },
    [LOCAL_ALLOC_SYSTEM_INODE]      = { "local_alloc:%04d", OCFS2_BITMAP_FL | OCFS2_LOCAL_ALLOC_FL, S_IFREG | 0644 },
    [TRUNCATE_LOG_SYSTEM_INODE]     = { "truncate_log:%04d", OCFS2_DEALLOC_FL, S_IFREG | 0644 },
    [LOCAL_USER_QUOTA_SYSTEM_INODE]     = { "aquota.user:%04d", OCFS2_QUOTA_FL, S_IFREG | 0644 },
    [LOCAL_GROUP_QUOTA_SYSTEM_INODE]    = { "aquota.group:%04d", OCFS2_QUOTA_FL, S_IFREG | 0644 },
};

/* Parameter passed from mount.ocfs2 to module */
#define OCFS2_HB_NONE           "heartbeat=none"
#define OCFS2_HB_LOCAL          "heartbeat=local"
#define OCFS2_HB_GLOBAL         "heartbeat=global"

/*
 * OCFS2 directory file types.  Only the low 3 bits are used.  The
 * other bits are reserved for now.
 */
#define OCFS2_FT_UNKNOWN    0
#define OCFS2_FT_REG_FILE   1
#define OCFS2_FT_DIR        2
#define OCFS2_FT_CHRDEV     3
#define OCFS2_FT_BLKDEV     4
#define OCFS2_FT_FIFO       5
#define OCFS2_FT_SOCK       6
#define OCFS2_FT_SYMLINK    7

#define OCFS2_FT_MAX        8

/*
 * OCFS2_DIR_PAD defines the directory entries boundaries
 *
 * NOTE: It must be a multiple of 4
 */
#define OCFS2_DIR_PAD           4
#define OCFS2_DIR_ROUND         (OCFS2_DIR_PAD - 1)
#define OCFS2_DIR_MEMBER_LEN        offsetof(struct ocfs2_dir_entry, name)
#define OCFS2_DIR_REC_LEN(name_len) (((name_len) + OCFS2_DIR_MEMBER_LEN + \
                                          OCFS2_DIR_ROUND) & \
                     ~OCFS2_DIR_ROUND)
#define OCFS2_DIR_MIN_REC_LEN   OCFS2_DIR_REC_LEN(1)

#define OCFS2_LINK_MAX      32000
#define OCFS2_DX_LINK_MAX   ((1U << 31) - 1U)
#define OCFS2_LINKS_HI_SHIFT    16
#define OCFS2_DX_ENTRIES_MAX    (0xffffffffU)

#define S_SHIFT         12
static unsigned char ocfs2_type_by_mode[S_IFMT >> S_SHIFT] = {
    [S_IFREG >> S_SHIFT]  = OCFS2_FT_REG_FILE,
    [S_IFDIR >> S_SHIFT]  = OCFS2_FT_DIR,
    [S_IFCHR >> S_SHIFT]  = OCFS2_FT_CHRDEV,
    [S_IFBLK >> S_SHIFT]  = OCFS2_FT_BLKDEV,
    [S_IFIFO >> S_SHIFT]  = OCFS2_FT_FIFO,
    [S_IFSOCK >> S_SHIFT] = OCFS2_FT_SOCK,
    [S_IFLNK >> S_SHIFT]  = OCFS2_FT_SYMLINK,
};


/*
 * Convenience casts
 */
#define OCFS2_RAW_SB(dinode)        (&((dinode)->id2.i_super))

/*
 * Block checking structure.  This is used in metadata to validate the
 * contents.  If OCFS2_FEATURE_INCOMPAT_META_ECC is not set, it is all
 * zeros.
 */
struct ocfs2_block_check {
/*00*/  __le32 bc_crc32e;   /* 802.3 Ethernet II CRC32 */
    __le16 bc_ecc;      /* Single-error-correction parity vector.
                   This is a simple Hamming code dependent
                   on the blocksize.  OCFS2's maximum
                   blocksize, 4K, requires 16 parity bits,
                   so we fit in __le16. */
    __le16 bc_reserved1;
/*08*/
};

/*
 * On disk extent record for OCFS2
 * It describes a range of clusters on disk.
 *
 * Length fields are divided into interior and leaf node versions.
 * This leaves room for a flags field (OCFS2_EXT_*) in the leaf nodes.
 */
struct ocfs2_extent_rec {
/*00*/  __le32 e_cpos;      /* Offset into the file, in clusters */
    union {
        __le32 e_int_clusters; /* Clusters covered by all children */
        struct {
            __le16 e_leaf_clusters; /* Clusters covered by this
                           extent */
            __u8 e_reserved1;
            __u8 e_flags; /* Extent flags */
        };
    };
    __le64 e_blkno;     /* Physical disk offset, in blocks */
/*10*/
};

struct ocfs2_chain_rec {
    __le32 c_free;  /* Number of free bits in this chain. */
    __le32 c_total; /* Number of total bits in this chain */
    __le64 c_blkno; /* Physical disk offset (blocks) of 1st group */
};

struct ocfs2_truncate_rec {
    __le32 t_start;     /* 1st cluster in this log */
    __le32 t_clusters;  /* Number of total clusters covered */
};

/*
 * On disk extent list for OCFS2 (node in the tree).  Note that this
 * is contained inside ocfs2_dinode or ocfs2_extent_block, so the
 * offsets are relative to ocfs2_dinode.id2.i_list or
 * ocfs2_extent_block.h_list, respectively.
 */
struct ocfs2_extent_list {
/*00*/  __le16 l_tree_depth;        /* Extent tree depth from this
                       point.  0 means data extents
                       hang directly off this
                       header (a leaf)
                       NOTE: The high 8 bits cannot be
                       used - tree_depth is never that big.
                    */
    __le16 l_count;         /* Number of extent records */
    __le16 l_next_free_rec;     /* Next unused extent slot */
    __le16 l_reserved1;
    __le64 l_reserved2;     /* Pad to
                       sizeof(ocfs2_extent_rec) */
/*10*/  struct ocfs2_extent_rec l_recs[0];  /* Extent records */
};

/*
 * On disk allocation chain list for OCFS2.  Note that this is
 * contained inside ocfs2_dinode, so the offsets are relative to
 * ocfs2_dinode.id2.i_chain.
 */
struct ocfs2_chain_list {
/*00*/  __le16 cl_cpg;          /* Clusters per Block Group */
    __le16 cl_bpc;          /* Bits per cluster */
    __le16 cl_count;        /* Total chains in this list */
    __le16 cl_next_free_rec;    /* Next unused chain slot */
    __le64 cl_reserved1;
/*10*/  struct ocfs2_chain_rec cl_recs[0];  /* Chain records */
};

/*
 * On disk deallocation log for OCFS2.  Note that this is
 * contained inside ocfs2_dinode, so the offsets are relative to
 * ocfs2_dinode.id2.i_dealloc.
 */
struct ocfs2_truncate_log {
/*00*/  __le16 tl_count;        /* Total records in this log */
    __le16 tl_used;         /* Number of records in use */
    __le32 tl_reserved1;
/*08*/  struct ocfs2_truncate_rec tl_recs[0];   /* Truncate records */
};

/*
 * On disk extent block (indirect block) for OCFS2
 */
struct ocfs2_extent_block
{
/*00*/  __u8 h_signature[8];        /* Signature for verification */
    struct ocfs2_block_check h_check;   /* Error checking */
/*10*/  __le16 h_suballoc_slot;     /* Slot suballocator this
                       extent_header belongs to */
    __le16 h_suballoc_bit;      /* Bit offset in suballocator
                       block group */
    __le32 h_fs_generation;     /* Must match super block */
    __le64 h_blkno;         /* Offset on disk, in blocks */
/*20*/  __le64 h_suballoc_loc;      /* Suballocator block group this
                       eb belongs to.  Only valid
                       if allocated from a
                       discontiguous block group */
    __le64 h_next_leaf_blk;     /* Offset on disk, in blocks,
                       of next leaf header pointing
                       to data */
/*30*/  struct ocfs2_extent_list h_list;    /* Extent record list */
/* Actual on-disk size is one block */
};

/*
 * On disk slot map for OCFS2.  This defines the contents of the "slot_map"
 * system file.  A slot is valid if it contains a node number >= 0.  The
 * value -1 (0xFFFF) is OCFS2_INVALID_SLOT.  This marks a slot empty.
 */
struct ocfs2_slot_map {
/*00*/  __le16 sm_slots[0];
/*
 * Actual on-disk size is one block.  OCFS2_MAX_SLOTS is 255,
 * 255 * sizeof(__le16) == 512B, within the 512B block minimum blocksize.
 */
};

struct ocfs2_extended_slot {
/*00*/  __u8    es_valid;
    __u8    es_reserved1[3];
    __le32  es_node_num;
/*10*/
};

/*
 * The extended slot map, used when OCFS2_FEATURE_INCOMPAT_EXTENDED_SLOT_MAP
 * is set.  It separates out the valid marker from the node number, and
 * has room to grow.  Unlike the old slot map, this format is defined by
 * i_size.
 */
struct ocfs2_slot_map_extended {
/*00*/  struct ocfs2_extended_slot se_slots[0];
/*
 * Actual size is i_size of the slot_map system file.  It should
 * match s_max_slots * sizeof(struct ocfs2_extended_slot)
 */
};

/*
 * ci_stackflags is only valid if the incompat bit
 * OCFS2_FEATURE_INCOMPAT_CLUSTERINFO is set.
 */
struct ocfs2_cluster_info {
/*00*/  __u8   ci_stack[OCFS2_STACK_LABEL_LEN];
    union {
        __le32 ci_reserved;
        struct {
            __u8 ci_stackflags;
            __u8 ci_reserved1;
            __u8 ci_reserved2;
            __u8 ci_reserved3;
        };
    };
/*08*/  __u8   ci_cluster[OCFS2_CLUSTER_NAME_LEN];
/*18*/
};

/*
 * On disk superblock for OCFS2
 * Note that it is contained inside an ocfs2_dinode, so all offsets
 * are relative to the start of ocfs2_dinode.id2.
 */
struct ocfs2_super_block {
/*00*/  __le16 s_major_rev_level;
    __le16 s_minor_rev_level;
    __le16 s_mnt_count;
    __le16 s_max_mnt_count;
    __le16 s_state;         /* File system state */
    __le16 s_errors;            /* Behaviour when detecting errors */
    __le32 s_checkinterval;     /* Max time between checks */
/*10*/  __le64 s_lastcheck;     /* Time of last check */
    __le32 s_creator_os;        /* OS */
    __le32 s_feature_compat;        /* Compatible feature set */
/*20*/  __le32 s_feature_incompat;  /* Incompatible feature set */
    __le32 s_feature_ro_compat; /* Readonly-compatible feature set */
    __le64 s_root_blkno;        /* Offset, in blocks, of root directory
                       dinode */
/*30*/  __le64 s_system_dir_blkno;  /* Offset, in blocks, of system
                       directory dinode */
    __le32 s_blocksize_bits;        /* Blocksize for this fs */
    __le32 s_clustersize_bits;  /* Clustersize for this fs */
/*40*/  __le16 s_max_slots;     /* Max number of simultaneous mounts
                       before tunefs required */
    __le16 s_tunefs_flag;
    __le32 s_uuid_hash;     /* hash value of uuid */
    __le64 s_first_cluster_group;   /* Block offset of 1st cluster
                     * group header */
/*50*/  __u8  s_label[OCFS2_MAX_VOL_LABEL_LEN]; /* Label for mounting, etc. */
/*90*/  __u8  s_uuid[OCFS2_VOL_UUID_LEN];   /* 128-bit uuid */
/*A0*/  struct ocfs2_cluster_info s_cluster_info; /* Only valid if either
                             userspace or clusterinfo
                             INCOMPAT flag set. */
/*B8*/  __le16 s_xattr_inline_size; /* extended attribute inline size
                       for this fs*/
    __le16 s_reserved0;
    __le32 s_dx_seed[3];        /* seed[0-2] for dx dir hash.
                     * s_uuid_hash serves as seed[3]. */
/*C0*/  __le64 s_reserved2[15];     /* Fill out superblock */
/*140*/

    /*
     * NOTE: As stated above, all offsets are relative to
     * ocfs2_dinode.id2, which is at 0xC0 in the inode.
     * 0xC0 + 0x140 = 0x200 or 512 bytes.  A superblock must fit within
     * our smallest blocksize, which is 512 bytes.  To ensure this,
     * we reserve the space in s_reserved2.  Anything past s_reserved2
     * will not be available on the smallest blocksize.
     */
};

/*
 * Local allocation bitmap for OCFS2 slots
 * Note that it exists inside an ocfs2_dinode, so all offsets are
 * relative to the start of ocfs2_dinode.id2.
 */
struct ocfs2_local_alloc
{
/*00*/  __le32 la_bm_off;   /* Starting bit offset in main bitmap */
    __le16 la_size;     /* Size of included bitmap, in bytes */
    __le16 la_reserved1;
    __le64 la_reserved2;
/*10*/  __u8   la_bitmap[0];
};

/*
 * Data-in-inode header. This is only used if i_dyn_features has
 * OCFS2_INLINE_DATA_FL set.
 */
struct ocfs2_inline_data
{
/*00*/  __le16  id_count;   /* Number of bytes that can be used
                 * for data, starting at id_data */
    __le16  id_reserved0;
    __le32  id_reserved1;
    __u8    id_data[0]; /* Start of user data */
};

/*
 * On disk inode for OCFS2
 */
struct ocfs2_dinode {
/*00*/  __u8 i_signature[8];        /* Signature for validation */
    __le32 i_generation;        /* Generation number */
    __le16 i_suballoc_slot;     /* Slot suballocator this inode
                       belongs to */
    __le16 i_suballoc_bit;      /* Bit offset in suballocator
                       block group */
/*10*/  __le16 i_links_count_hi;    /* High 16 bits of links count */
    __le16 i_xattr_inline_size;
    __le32 i_clusters;      /* Cluster count */
    __le32 i_uid;           /* Owner UID */
    __le32 i_gid;           /* Owning GID */
/*20*/  __le64 i_size;          /* Size in bytes */
    __le16 i_mode;          /* File mode */
    __le16 i_links_count;       /* Links count */
    __le32 i_flags;         /* File flags */
/*30*/  __le64 i_atime;         /* Access time */
    __le64 i_ctime;         /* Creation time */
/*40*/  __le64 i_mtime;         /* Modification time */
    __le64 i_dtime;         /* Deletion time */
/*50*/  __le64 i_blkno;         /* Offset on disk, in blocks */
    __le64 i_last_eb_blk;       /* Pointer to last extent
                       block */
/*60*/  __le32 i_fs_generation;     /* Generation per fs-instance */
    __le32 i_atime_nsec;
    __le32 i_ctime_nsec;
    __le32 i_mtime_nsec;
/*70*/  __le32 i_attr;
    __le16 i_orphaned_slot;     /* Only valid when OCFS2_ORPHANED_FL
                       was set in i_flags */
    __le16 i_dyn_features;
    __le64 i_xattr_loc;
/*80*/  struct ocfs2_block_check i_check;   /* Error checking */
/*88*/  __le64 i_dx_root;       /* Pointer to dir index root block */
/*90*/  __le64 i_refcount_loc;
    __le64 i_suballoc_loc;      /* Suballocator block group this
                       inode belongs to.  Only valid
                       if allocated from a
                       discontiguous block group */
/*A0*/  __le64 i_reserved2[3];
/*B8*/  union {
        __le64 i_pad1;      /* Generic way to refer to this
                       64bit union */
        struct {
            __le64 i_rdev;  /* Device number */
        } dev1;
        struct {        /* Info for bitmap system
                       inodes */
            __le32 i_used;  /* Bits (ie, clusters) used  */
            __le32 i_total; /* Total bits (clusters)
                       available */
        } bitmap1;
        struct {        /* Info for journal system
                       inodes */
            __le32 ij_flags;    /* Mounted, version, etc. */
            __le32 ij_recovery_generation; /* Incremented when the
                              journal is recovered
                              after an unclean
                              shutdown */
        } journal1;
    } id1;              /* Inode type dependent 1 */
/*C0*/  union {
        struct ocfs2_super_block    i_super;
        struct ocfs2_local_alloc    i_lab;
        struct ocfs2_chain_list     i_chain;
        struct ocfs2_extent_list    i_list;
        struct ocfs2_truncate_log   i_dealloc;
        struct ocfs2_inline_data    i_data;
        __u8                    i_symlink[0];
    } id2;
/* Actual on-disk size is one block */
};

/*
 * On-disk directory entry structure for OCFS2
 *
 * Packed as this structure could be accessed unaligned on 64-bit platforms
 */
struct ocfs2_dir_entry {
/*00*/  __le64   inode;                  /* Inode number */
    __le16   rec_len;                /* Directory entry length */
    __u8    name_len;               /* Name length */
    __u8    file_type;
/*0C*/  char    name[OCFS2_MAX_FILENAME_LEN];   /* File name */
/* Actual on-disk length specified by rec_len */
} __attribute__ ((packed));

/*
 * Per-block record for the unindexed directory btree. This is carefully
 * crafted so that the rec_len and name_len records of an ocfs2_dir_entry are
 * mirrored. That way, the directory manipulation code needs a minimal amount
 * of update.
 *
 * NOTE: Keep this structure aligned to a multiple of 4 bytes.
 */
struct ocfs2_dir_block_trailer {
/*00*/  __le64      db_compat_inode;    /* Always zero. Was inode */

    __le16      db_compat_rec_len;  /* Backwards compatible with
                         * ocfs2_dir_entry. */
    __u8        db_compat_name_len; /* Always zero. Was name_len */
    __u8        db_reserved0;
    __le16      db_reserved1;
    __le16      db_free_rec_len;    /* Size of largest empty hole
                         * in this block. (unused) */
/*10*/  __u8        db_signature[8];    /* Signature for verification */
    __le64      db_reserved2;
    __le64      db_free_next;       /* Next block in list (unused) */
/*20*/  __le64      db_blkno;       /* Offset on disk, in blocks */
    __le64      db_parent_dinode;   /* dinode which owns me, in
                           blocks */
/*30*/  struct ocfs2_block_check db_check;  /* Error checking */
/*40*/
};

 /*
 * A directory entry in the indexed tree. We don't store the full name here,
 * but instead provide a pointer to the full dirent in the unindexed tree.
 *
 * We also store name_len here so as to reduce the number of leaf blocks we
 * need to search in case of collisions.
 */
struct ocfs2_dx_entry {
    __le32      dx_major_hash;  /* Used to find logical
                     * cluster in index */
    __le32      dx_minor_hash;  /* Lower bits used to find
                     * block in cluster */
    __le64      dx_dirent_blk;  /* Physical block in unindexed
                     * tree holding this dirent. */
};

struct ocfs2_dx_entry_list {
    __le32      de_reserved;
    __le16      de_count;   /* Maximum number of entries
                     * possible in de_entries */
    __le16      de_num_used;    /* Current number of
                     * de_entries entries */
    struct  ocfs2_dx_entry      de_entries[0];  /* Indexed dir entries
                             * in a packed array of
                             * length de_num_used */
};

#define OCFS2_DX_FLAG_INLINE    0x01

/*
 * A directory indexing block. Each indexed directory has one of these,
 * pointed to by ocfs2_dinode.
 *
 * This block stores an indexed btree root, and a set of free space
 * start-of-list pointers.
 */
struct ocfs2_dx_root_block {
    __u8        dr_signature[8];    /* Signature for verification */
    struct ocfs2_block_check dr_check;  /* Error checking */
    __le16      dr_suballoc_slot;   /* Slot suballocator this
                         * block belongs to. */
    __le16      dr_suballoc_bit;    /* Bit offset in suballocator
                         * block group */
    __le32      dr_fs_generation;   /* Must match super block */
    __le64      dr_blkno;       /* Offset on disk, in blocks */
    __le64      dr_last_eb_blk;     /* Pointer to last
                         * extent block */
    __le32      dr_clusters;        /* Clusters allocated
                         * to the indexed tree. */
    __u8        dr_flags;       /* OCFS2_DX_FLAG_* flags */
    __u8        dr_reserved0;
    __le16      dr_reserved1;
    __le64      dr_dir_blkno;       /* Pointer to parent inode */
    __le32      dr_num_entries;     /* Total number of
                         * names stored in
                         * this directory.*/
    __le32      dr_reserved2;
    __le64      dr_free_blk;        /* Pointer to head of free
                         * unindexed block list. */
    __le64      dr_suballoc_loc;    /* Suballocator block group
                           this root belongs to.
                           Only valid if allocated
                           from a discontiguous
                           block group */
    __le64      dr_reserved3[14];
    union {
        struct ocfs2_extent_list dr_list; /* Keep this aligned to 128
                           * bits for maximum space
                           * efficiency. */
        struct ocfs2_dx_entry_list dr_entries; /* In-root-block list of
                            * entries. We grow out
                            * to extents if this
                            * gets too big. */
    };
};

/*
 * The header of a leaf block in the indexed tree.
 */
struct ocfs2_dx_leaf {
    __u8        dl_signature[8];/* Signature for verification */
    struct ocfs2_block_check dl_check;  /* Error checking */
    __le64      dl_blkno;   /* Offset on disk, in blocks */
    __le32      dl_fs_generation;/* Must match super block */
    __le32      dl_reserved0;
    __le64      dl_reserved1;
    struct ocfs2_dx_entry_list  dl_list;
};

/*
 * Largest bitmap for a block (suballocator) group in bytes.  This limit
 * does not affect cluster groups (global allocator).  Cluster group
 * bitmaps run to the end of the block.
 */
#define OCFS2_MAX_BG_BITMAP_SIZE    256

/*
 * On disk allocator group structure for OCFS2
 */
struct ocfs2_group_desc
{
/*00*/  __u8    bg_signature[8];        /* Signature for validation */
    __le16   bg_size;                /* Size of included bitmap in
                       bytes. */
    __le16   bg_bits;                /* Bits represented by this
                       group. */
    __le16  bg_free_bits_count;     /* Free bits count */
    __le16   bg_chain;               /* What chain I am in. */
/*10*/  __le32   bg_generation;
    __le32  bg_reserved1;
    __le64   bg_next_group;          /* Next group in my list, in
                       blocks */
/*20*/  __le64   bg_parent_dinode;       /* dinode which owns me, in
                       blocks */
    __le64   bg_blkno;               /* Offset on disk, in blocks */
/*30*/  struct ocfs2_block_check bg_check;  /* Error checking */
    __le64   bg_reserved2;
/*40*/  union {
        __u8    bg_bitmap[0];
        struct {
            /*
             * Block groups may be discontiguous when
             * OCFS2_FEATURE_INCOMPAT_DISCONTIG_BG is set.
             * The extents of a discontigous block group are
             * stored in bg_list.  It is a flat list.
             * l_tree_depth must always be zero.  A
             * discontiguous group is signified by a non-zero
             * bg_list->l_next_free_rec.  Only block groups
             * can be discontiguous; Cluster groups cannot.
             * We've never made a block group with more than
             * 2048 blocks (256 bytes of bg_bitmap).  This
             * codifies that limit so that we can fit bg_list.
             * bg_size of a discontiguous block group will
             * be 256 to match bg_bitmap_filler.
             */
            __u8 bg_bitmap_filler[OCFS2_MAX_BG_BITMAP_SIZE];
/*140*/         struct ocfs2_extent_list bg_list;
        };
    };
/* Actual on-disk size is one block */
};

struct ocfs2_refcount_rec {
/*00*/  __le64 r_cpos;      /* Physical offset, in clusters */
    __le32 r_clusters;  /* Clusters covered by this extent */
    __le32 r_refcount;  /* Reference count of this extent */
/*10*/
};
#define OCFS2_32BIT_POS_MASK        (0xffffffffULL)

#define OCFS2_REFCOUNT_LEAF_FL          (0x00000001)
#define OCFS2_REFCOUNT_TREE_FL          (0x00000002)

struct ocfs2_refcount_list {
/*00*/  __le16 rl_count;    /* Maximum number of entries possible
                   in rl_records */
    __le16 rl_used;     /* Current number of used records */
    __le32 rl_reserved2;
    __le64 rl_reserved1;    /* Pad to sizeof(ocfs2_refcount_record) */
/*10*/  struct ocfs2_refcount_rec rl_recs[0];   /* Refcount records */
};


struct ocfs2_refcount_block {
/*00*/  __u8 rf_signature[8];       /* Signature for verification */
    __le16 rf_suballoc_slot;    /* Slot suballocator this block
                       belongs to */
    __le16 rf_suballoc_bit;     /* Bit offset in suballocator
                       block group */
    __le32 rf_fs_generation;    /* Must match superblock */
/*10*/  __le64 rf_blkno;        /* Offset on disk, in blocks */
    __le64 rf_parent;       /* Parent block, only valid if
                       OCFS2_REFCOUNT_LEAF_FL is set in
                       rf_flags */
/*20*/  struct ocfs2_block_check rf_check;  /* Error checking */
    __le64 rf_last_eb_blk;      /* Pointer to last extent block */
/*30*/  __le32 rf_count;        /* Number of inodes sharing this
                       refcount tree */
    __le32 rf_flags;        /* See the flags above */
    __le32 rf_clusters;     /* clusters covered by refcount tree. */
    __le32 rf_cpos;         /* cluster offset in refcount tree.*/
/*40*/  __le32 rf_generation;       /* generation number. all be the same
                     * for the same refcount tree. */
    __le32 rf_reserved0;
    __le64 rf_suballoc_loc;     /* Suballocator block group this
                       refcount block belongs to. Only
                       valid if allocated from a
                       discontiguous block group */
/*50*/  __le64 rf_reserved1[6];
/*80*/  union {
        struct ocfs2_refcount_list rf_records;  /* List of refcount
                              records */
        struct ocfs2_extent_list rf_list;   /* Extent record list,
                            only valid if
                            OCFS2_REFCOUNT_TREE_FL
                            is set in rf_flags */
    };
/* Actual on-disk size is one block */
};

/*
 * On disk extended attribute structure for OCFS2.
 */

/*
 * ocfs2_xattr_entry indicates one extend attribute.
 *
 * Note that it can be stored in inode, one block or one xattr bucket.
 */
struct ocfs2_xattr_entry {
    __le32  xe_name_hash;    /* hash value of xattr prefix+suffix. */
    __le16  xe_name_offset;  /* byte offset from the 1st entry in the
                    local xattr storage(inode, xattr block or
                    xattr bucket). */
    __u8    xe_name_len;     /* xattr name len, doesn't include prefix. */
    __u8    xe_type;         /* the low 7 bits indicate the name prefix
                  * type and the highest bit indicates whether
                  * the EA is stored in the local storage. */
    __le64  xe_value_size;   /* real xattr value length. */
};

/*
 * On disk structure for xattr header.
 *
 * One ocfs2_xattr_header describes how many ocfs2_xattr_entry records in
 * the local xattr storage.
 */
struct ocfs2_xattr_header {
    __le16  xh_count;                       /* contains the count of how
                           many records are in the
                           local xattr storage. */
    __le16  xh_free_start;                  /* current offset for storing
                           xattr. */
    __le16  xh_name_value_len;              /* total length of name/value
                           length in this bucket. */
    __le16  xh_num_buckets;                 /* Number of xattr buckets
                           in this extent record,
                           only valid in the first
                           bucket. */
    struct ocfs2_block_check xh_check;  /* Error checking
                           (Note, this is only
                            used for xattr
                            buckets.  A block uses
                            xb_check and sets
                            this field to zero.) */
    struct ocfs2_xattr_entry xh_entries[0]; /* xattr entry list. */
};

/*
 * On disk structure for xattr value root.
 *
 * When an xattr's value is large enough, it is stored in an external
 * b-tree like file data.  The xattr value root points to this structure.
 */
struct ocfs2_xattr_value_root {
/*00*/  __le32  xr_clusters;              /* clusters covered by xattr value. */
    __le32  xr_reserved0;
    __le64  xr_last_eb_blk;           /* Pointer to last extent block */
/*10*/  struct ocfs2_extent_list xr_list; /* Extent record list */
};

/*
 * On disk structure for xattr tree root.
 *
 * It is used when there are too many extended attributes for one file. These
 * attributes will be organized and stored in an indexed-btree.
 */
struct ocfs2_xattr_tree_root {
/*00*/  __le32  xt_clusters;              /* clusters covered by xattr. */
    __le32  xt_reserved0;
    __le64  xt_last_eb_blk;           /* Pointer to last extent block */
/*10*/  struct ocfs2_extent_list xt_list; /* Extent record list */
};

#define OCFS2_XATTR_INDEXED 0x1
#define OCFS2_HASH_SHIFT    5
#define OCFS2_XATTR_ROUND   3
#define OCFS2_XATTR_SIZE(size)  (((size) + OCFS2_XATTR_ROUND) & \
                ~(OCFS2_XATTR_ROUND))

#define OCFS2_XATTR_BUCKET_SIZE         4096
#define OCFS2_XATTR_MAX_BLOCKS_PER_BUCKET   (OCFS2_XATTR_BUCKET_SIZE \
                         / OCFS2_MIN_BLOCKSIZE)

/*
 * On disk structure for xattr block.
 */
struct ocfs2_xattr_block {
/*00*/  __u8    xb_signature[8];     /* Signature for verification */
    __le16  xb_suballoc_slot;    /* Slot suballocator this
                    block belongs to. */
    __le16  xb_suballoc_bit;     /* Bit offset in suballocator
                    block group */
    __le32  xb_fs_generation;    /* Must match super block */
/*10*/  __le64  xb_blkno;            /* Offset on disk, in blocks */
    struct ocfs2_block_check xb_check;  /* Error checking */
/*20*/  __le16  xb_flags;            /* Indicates whether this block contains
                    real xattr or a xattr tree. */
    __le16  xb_reserved0;
    __le32  xb_reserved1;
    __le64  xb_suballoc_loc;    /* Suballocator block group this
                       xattr block belongs to. Only
                       valid if allocated from a
                       discontiguous block group */
/*30*/  union {
        struct ocfs2_xattr_header xb_header; /* xattr header if this
                            block contains xattr */
        struct ocfs2_xattr_tree_root xb_root;/* xattr tree root if this
                            block cotains xattr
                            tree. */
    } xb_attrs;
};

#define OCFS2_XATTR_ENTRY_LOCAL     0x80
#define OCFS2_XATTR_TYPE_MASK       0x7F
static inline void ocfs2_xattr_set_local(struct ocfs2_xattr_entry *xe,
                     int local)
{
    if (local)
        xe->xe_type |= OCFS2_XATTR_ENTRY_LOCAL;
    else
        xe->xe_type &= ~OCFS2_XATTR_ENTRY_LOCAL;
}

static inline int ocfs2_xattr_is_local(struct ocfs2_xattr_entry *xe)
{
    return xe->xe_type & OCFS2_XATTR_ENTRY_LOCAL;
}

static inline void ocfs2_xattr_set_type(struct ocfs2_xattr_entry *xe, int type)
{
    xe->xe_type |= type & OCFS2_XATTR_TYPE_MASK;
}

static inline int ocfs2_xattr_get_type(struct ocfs2_xattr_entry *xe)
{
    return xe->xe_type & OCFS2_XATTR_TYPE_MASK;
}

/*
 *  On disk structures for global quota file
 */

/* Magic numbers and known versions for global quota files */
#define OCFS2_GLOBAL_QMAGICS {\
    0x0cf52470, /* USRQUOTA */ \
    0x0cf52471  /* GRPQUOTA */ \
}

#define OCFS2_GLOBAL_QVERSIONS {\
    0, \
    0, \
}


/* Each block of each quota file has a certain fixed number of bytes reserved
 * for OCFS2 internal use at its end. OCFS2 can use it for things like
 * checksums, etc. */
#define OCFS2_QBLK_RESERVED_SPACE 8

/* Generic header of all quota files */
struct ocfs2_disk_dqheader {
    __le32 dqh_magic;   /* Magic number identifying file */
    __le32 dqh_version; /* Quota format version */
};

#define OCFS2_GLOBAL_INFO_OFF (sizeof(struct ocfs2_disk_dqheader))

/* Information header of global quota file (immediately follows the generic
 * header) */
struct ocfs2_global_disk_dqinfo {
/*00*/  __le32 dqi_bgrace;  /* Grace time for space softlimit excess */
    __le32 dqi_igrace;  /* Grace time for inode softlimit excess */
    __le32 dqi_syncms;  /* Time after which we sync local changes to
                 * global quota file */
    __le32 dqi_blocks;  /* Number of blocks in quota file */
/*10*/  __le32 dqi_free_blk;    /* First free block in quota file */
    __le32 dqi_free_entry;  /* First block with free dquot entry in quota
                 * file */
};

/* Structure with global user / group information. We reserve some space
 * for future use. */
struct ocfs2_global_disk_dqblk {
/*00*/  __le32 dqb_id;          /* ID the structure belongs to */
    __le32 dqb_use_count;   /* Number of nodes having reference to this structure */
    __le64 dqb_ihardlimit;  /* absolute limit on allocated inodes */
/*10*/  __le64 dqb_isoftlimit;  /* preferred inode limit */
    __le64 dqb_curinodes;   /* current # allocated inodes */
/*20*/  __le64 dqb_bhardlimit;  /* absolute limit on disk space */
    __le64 dqb_bsoftlimit;  /* preferred limit on disk space */
/*30*/  __le64 dqb_curspace;    /* current space occupied */
    __le64 dqb_btime;       /* time limit for excessive disk use */
/*40*/  __le64 dqb_itime;       /* time limit for excessive inode use */
    __le64 dqb_pad1;
/*50*/  __le64 dqb_pad2;
};

/*
 *  On-disk structures for local quota file
 */

/* Magic numbers and known versions for local quota files */
#define OCFS2_LOCAL_QMAGICS {\
    0x0cf524c0, /* USRQUOTA */ \
    0x0cf524c1  /* GRPQUOTA */ \
}

#define OCFS2_LOCAL_QVERSIONS {\
    0, \
    0, \
}

/* Quota flags in dqinfo header */
#define OLQF_CLEAN  0x0001  /* Quota file is empty (this should be after\
                 * quota has been cleanly turned off) */

#define OCFS2_LOCAL_INFO_OFF (sizeof(struct ocfs2_disk_dqheader))

/* Information header of local quota file (immediately follows the generic
 * header) */
struct ocfs2_local_disk_dqinfo {
    __le32 dqi_flags;   /* Flags for quota file */
    __le32 dqi_chunks;  /* Number of chunks of quota structures
                 * with a bitmap */
    __le32 dqi_blocks;  /* Number of blocks allocated for quota file */
};

/* Header of one chunk of a quota file */
struct ocfs2_local_disk_chunk {
    __le32 dqc_free;    /* Number of free entries in the bitmap */
    __u8 dqc_bitmap[0]; /* Bitmap of entries in the corresponding
                 * chunk of quota file */
};

/* One entry in local quota file */
struct ocfs2_local_disk_dqblk {
/*00*/  __le64 dqb_id;      /* id this quota applies to */
    __le64 dqb_spacemod;    /* Change in the amount of used space */
/*10*/  __le64 dqb_inodemod;    /* Change in the amount of used inodes */
};


/*
 * The quota trailer lives at the end of each quota block.
 */

struct ocfs2_disk_dqtrailer {
/*00*/  struct ocfs2_block_check dq_check;  /* Error checking */
/*08*/  /* Cannot be larger than OCFS2_QBLK_RESERVED_SPACE */
};

static inline struct ocfs2_disk_dqtrailer *ocfs2_block_dqtrailer(int blocksize,
                                 void *buf)
{
    char *ptr = buf;
    ptr += blocksize - OCFS2_QBLK_RESERVED_SPACE;

    return (struct ocfs2_disk_dqtrailer *)ptr;
}

#ifdef __KERNEL__
static inline int ocfs2_fast_symlink_chars(struct super_block *sb)
{
    return  sb->s_blocksize -
         offsetof(struct ocfs2_dinode, id2.i_symlink);
}

static inline int ocfs2_max_inline_data_with_xattr(struct super_block *sb,
                           struct ocfs2_dinode *di)
{
    unsigned int xattrsize = le16_to_cpu(di->i_xattr_inline_size);

    if (le16_to_cpu(di->i_dyn_features) & OCFS2_INLINE_XATTR_FL)
        return sb->s_blocksize -
            offsetof(struct ocfs2_dinode, id2.i_data.id_data) -
            xattrsize;
    else
        return sb->s_blocksize -
            offsetof(struct ocfs2_dinode, id2.i_data.id_data);
}

static inline int ocfs2_extent_recs_per_inode(struct super_block *sb)
{
    int size;

    size = sb->s_blocksize -
        offsetof(struct ocfs2_dinode, id2.i_list.l_recs);

    return size / sizeof(struct ocfs2_extent_rec);
}

static inline int ocfs2_extent_recs_per_inode_with_xattr(
                        struct super_block *sb,
                        struct ocfs2_dinode *di)
{
    int size;
    unsigned int xattrsize = le16_to_cpu(di->i_xattr_inline_size);

    if (le16_to_cpu(di->i_dyn_features) & OCFS2_INLINE_XATTR_FL)
        size = sb->s_blocksize -
            offsetof(struct ocfs2_dinode, id2.i_list.l_recs) -
            xattrsize;
    else
        size = sb->s_blocksize -
            offsetof(struct ocfs2_dinode, id2.i_list.l_recs);

    return size / sizeof(struct ocfs2_extent_rec);
}

static inline int ocfs2_extent_recs_per_dx_root(struct super_block *sb)
{
    int size;

    size = sb->s_blocksize -
        offsetof(struct ocfs2_dx_root_block, dr_list.l_recs);

    return size / sizeof(struct ocfs2_extent_rec);
}

static inline int ocfs2_chain_recs_per_inode(struct super_block *sb)
{
    int size;

    size = sb->s_blocksize -
        offsetof(struct ocfs2_dinode, id2.i_chain.cl_recs);

    return size / sizeof(struct ocfs2_chain_rec);
}

static inline u16 ocfs2_extent_recs_per_eb(struct super_block *sb)
{
    int size;

    size = sb->s_blocksize -
        offsetof(struct ocfs2_extent_block, h_list.l_recs);

    return size / sizeof(struct ocfs2_extent_rec);
}

static inline u16 ocfs2_extent_recs_per_gd(struct super_block *sb)
{
    int size;

    size = sb->s_blocksize -
        offsetof(struct ocfs2_group_desc, bg_list.l_recs);

    return size / sizeof(struct ocfs2_extent_rec);
}

static inline int ocfs2_dx_entries_per_leaf(struct super_block *sb)
{
    int size;

    size = sb->s_blocksize -
        offsetof(struct ocfs2_dx_leaf, dl_list.de_entries);

    return size / sizeof(struct ocfs2_dx_entry);
}

static inline int ocfs2_dx_entries_per_root(struct super_block *sb)
{
    int size;

    size = sb->s_blocksize -
        offsetof(struct ocfs2_dx_root_block, dr_entries.de_entries);

    return size / sizeof(struct ocfs2_dx_entry);
}

static inline u16 ocfs2_local_alloc_size(struct super_block *sb)
{
    u16 size;

    size = sb->s_blocksize -
        offsetof(struct ocfs2_dinode, id2.i_lab.la_bitmap);

    return size;
}

static inline int ocfs2_group_bitmap_size(struct super_block *sb,
                      int suballocator,
                      u32 feature_incompat)
{
    int size = sb->s_blocksize -
        offsetof(struct ocfs2_group_desc, bg_bitmap);

    /*
     * The cluster allocator uses the entire block.  Suballocators have
     * never used more than OCFS2_MAX_BG_BITMAP_SIZE.  Unfortunately, older
     * code expects bg_size set to the maximum.  Thus we must keep
     * bg_size as-is unless discontig_bg is enabled.
     */
    if (suballocator &&
        (feature_incompat & OCFS2_FEATURE_INCOMPAT_DISCONTIG_BG))
        size = OCFS2_MAX_BG_BITMAP_SIZE;

    return size;
}

static inline int ocfs2_truncate_recs_per_inode(struct super_block *sb)
{
    int size;

    size = sb->s_blocksize -
        offsetof(struct ocfs2_dinode, id2.i_dealloc.tl_recs);

    return size / sizeof(struct ocfs2_truncate_rec);
}

static inline u64 ocfs2_backup_super_blkno(struct super_block *sb, int index)
{
    u64 offset = OCFS2_BACKUP_SB_START;

    if (index >= 0 && index < OCFS2_MAX_BACKUP_SUPERBLOCKS) {
        offset <<= (2 * index);
        offset >>= sb->s_blocksize_bits;
        return offset;
    }

    return 0;

}

static inline u16 ocfs2_xattr_recs_per_xb(struct super_block *sb)
{
    int size;

    size = sb->s_blocksize -
        offsetof(struct ocfs2_xattr_block,
             xb_attrs.xb_root.xt_list.l_recs);

    return size / sizeof(struct ocfs2_extent_rec);
}

static inline u16 ocfs2_extent_recs_per_rb(struct super_block *sb)
{
    int size;

    size = sb->s_blocksize -
        offsetof(struct ocfs2_refcount_block, rf_list.l_recs);

    return size / sizeof(struct ocfs2_extent_rec);
}

static inline u16 ocfs2_refcount_recs_per_rb(struct super_block *sb)
{
    int size;

    size = sb->s_blocksize -
        offsetof(struct ocfs2_refcount_block, rf_records.rl_recs);

    return size / sizeof(struct ocfs2_refcount_rec);
}

static inline u32
ocfs2_get_ref_rec_low_cpos(const struct ocfs2_refcount_rec *rec)
{
    return le64_to_cpu(rec->r_cpos) & OCFS2_32BIT_POS_MASK;
}
#else
static inline int ocfs2_fast_symlink_chars(int blocksize)
{
    return blocksize - offsetof(struct ocfs2_dinode, id2.i_symlink);
}

static inline int ocfs2_max_inline_data_with_xattr(int blocksize,
                           struct ocfs2_dinode *di)
{
    if (di && (di->i_dyn_features & OCFS2_INLINE_XATTR_FL))
        return blocksize -
            offsetof(struct ocfs2_dinode, id2.i_data.id_data) -
            di->i_xattr_inline_size;
    else
        return blocksize -
            offsetof(struct ocfs2_dinode, id2.i_data.id_data);
}

static inline int ocfs2_extent_recs_per_inode(int blocksize)
{
    int size;

    size = blocksize -
        offsetof(struct ocfs2_dinode, id2.i_list.l_recs);

    return size / sizeof(struct ocfs2_extent_rec);
}

static inline int ocfs2_chain_recs_per_inode(int blocksize)
{
    int size;

    size = blocksize -
        offsetof(struct ocfs2_dinode, id2.i_chain.cl_recs);

    return size / sizeof(struct ocfs2_chain_rec);
}

static inline int ocfs2_extent_recs_per_eb(int blocksize)
{
    int size;

    size = blocksize -
        offsetof(struct ocfs2_extent_block, h_list.l_recs);

    return size / sizeof(struct ocfs2_extent_rec);
}

static inline int ocfs2_extent_recs_per_gd(int blocksize)
{
    int size;

    size = blocksize -
        offsetof(struct ocfs2_group_desc, bg_list.l_recs);

    return size / sizeof(struct ocfs2_extent_rec);
}

static inline int ocfs2_local_alloc_size(int blocksize)
{
    int size;

    size = blocksize -
        offsetof(struct ocfs2_dinode, id2.i_lab.la_bitmap);

    return size;
}

static inline int ocfs2_group_bitmap_size(int blocksize,
                      int suballocator,
                      uint32_t feature_incompat)
{
    int size = sb->s_blocksize -
        offsetof(struct ocfs2_group_desc, bg_bitmap);

    /*
     * The cluster allocator uses the entire block.  Suballocators have
     * never used more than OCFS2_MAX_BG_BITMAP_SIZE.  Unfortunately, older
     * code expects bg_size set to the maximum.  Thus we must keep
     * bg_size as-is unless discontig_bg is enabled.
     */
    if (suballocator &&
        (feature_incompat & OCFS2_FEATURE_INCOMPAT_DISCONTIG_BG))
        size = OCFS2_MAX_BG_BITMAP_SIZE;

    return size;
}

static inline int ocfs2_truncate_recs_per_inode(int blocksize)
{
    int size;

    size = blocksize -
        offsetof(struct ocfs2_dinode, id2.i_dealloc.tl_recs);

    return size / sizeof(struct ocfs2_truncate_rec);
}

static inline uint64_t ocfs2_backup_super_blkno(int blocksize, int index)
{
    uint64_t offset = OCFS2_BACKUP_SB_START;

    if (index >= 0 && index < OCFS2_MAX_BACKUP_SUPERBLOCKS) {
        offset <<= (2 * index);
        offset /= blocksize;
        return offset;
    }

    return 0;
}

static inline int ocfs2_xattr_recs_per_xb(int blocksize)
{
    int size;

    size = blocksize -
        offsetof(struct ocfs2_xattr_block,
             xb_attrs.xb_root.xt_list.l_recs);

    return size / sizeof(struct ocfs2_extent_rec);
}
#endif  /* __KERNEL__ */


static inline int ocfs2_system_inode_is_global(int type)
{
    return ((type >= 0) &&
        (type <= OCFS2_LAST_GLOBAL_SYSTEM_INODE));
}

static inline int ocfs2_sprintf_system_inode_name(char *buf, int len,
                          int type, int slot)
{
    int chars;

        /*
         * Global system inodes can only have one copy.  Everything
         * after OCFS2_LAST_GLOBAL_SYSTEM_INODE in the system inode
         * list has a copy per slot.
         */
    if (type <= OCFS2_LAST_GLOBAL_SYSTEM_INODE)
        chars = snprintf(buf, len, "%s",
                 ocfs2_system_inodes[type].si_name);
    else
        chars = snprintf(buf, len,
                 ocfs2_system_inodes[type].si_name,
                 slot);

    return chars;
}

static inline void ocfs2_set_de_type(struct ocfs2_dir_entry *de,
                    umode_t mode)
{
    de->file_type = ocfs2_type_by_mode[(mode & S_IFMT)>>S_SHIFT];
}

static inline int ocfs2_gd_is_discontig(struct ocfs2_group_desc *gd)
{
    if ((offsetof(struct ocfs2_group_desc, bg_bitmap) +
         le16_to_cpu(gd->bg_size)) !=
        offsetof(struct ocfs2_group_desc, bg_list))
        return 0;
    /*
     * Only valid to check l_next_free_rec if
     * bg_bitmap + bg_size == bg_list.
     */
    if (!gd->bg_list.l_next_free_rec)
        return 0;
    return 1;
}
#endif  /* _OCFS2_FS_H */