gfs2_ondisk.h

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/*
 * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
 * Copyright (C) 2004-2006 Red Hat, Inc.  All rights reserved.
 *
 * This copyrighted material is made available to anyone wishing to use,
 * modify, copy, or redistribute it subject to the terms and conditions
 * of the GNU General Public License v.2.
 */

#ifndef __GFS2_ONDISK_DOT_H__
#define __GFS2_ONDISK_DOT_H__

#include <linux/types.h>

#define GFS2_MAGIC      0x01161970
#define GFS2_BASIC_BLOCK    512
#define GFS2_BASIC_BLOCK_SHIFT  9

/* Lock numbers of the LM_TYPE_NONDISK type */

#define GFS2_MOUNT_LOCK     0
#define GFS2_LIVE_LOCK      1
#define GFS2_TRANS_LOCK     2
#define GFS2_RENAME_LOCK    3
#define GFS2_CONTROL_LOCK   4
#define GFS2_MOUNTED_LOCK   5

/* Format numbers for various metadata types */

#define GFS2_FORMAT_NONE    0
#define GFS2_FORMAT_SB      100
#define GFS2_FORMAT_RG      200
#define GFS2_FORMAT_RB      300
#define GFS2_FORMAT_DI      400
#define GFS2_FORMAT_IN      500
#define GFS2_FORMAT_LF      600
#define GFS2_FORMAT_JD      700
#define GFS2_FORMAT_LH      800
#define GFS2_FORMAT_LD      900
#define GFS2_FORMAT_LB      1000
#define GFS2_FORMAT_EA      1600
#define GFS2_FORMAT_ED      1700
#define GFS2_FORMAT_QC      1400
/* These are format numbers for entities contained in files */
#define GFS2_FORMAT_RI      1100
#define GFS2_FORMAT_DE      1200
#define GFS2_FORMAT_QU      1500
/* These are part of the superblock */
#define GFS2_FORMAT_FS      1801
#define GFS2_FORMAT_MULTI   1900

/*
 * An on-disk inode number
 */

struct gfs2_inum {
    __be64 no_formal_ino;
    __be64 no_addr;
};

/*
 * Generic metadata head structure
 * Every inplace buffer logged in the journal must start with this.
 */

#define GFS2_METATYPE_NONE  0
#define GFS2_METATYPE_SB    1
#define GFS2_METATYPE_RG    2
#define GFS2_METATYPE_RB    3
#define GFS2_METATYPE_DI    4
#define GFS2_METATYPE_IN    5
#define GFS2_METATYPE_LF    6
#define GFS2_METATYPE_JD    7
#define GFS2_METATYPE_LH    8
#define GFS2_METATYPE_LD    9
#define GFS2_METATYPE_LB    12
#define GFS2_METATYPE_EA    10
#define GFS2_METATYPE_ED    11
#define GFS2_METATYPE_QC    14

struct gfs2_meta_header {
    __be32 mh_magic;
    __be32 mh_type;
    __be64 __pad0;      /* Was generation number in gfs1 */
    __be32 mh_format;
    /* This union is to keep userspace happy */
    union {
        __be32 mh_jid;      /* Was incarnation number in gfs1 */
        __be32 __pad1;
    };
};

/*
 * super-block structure
 *
 * It's probably good if SIZEOF_SB <= GFS2_BASIC_BLOCK (512 bytes)
 *
 * Order is important, need to be able to read old superblocks to do on-disk
 * version upgrades.
 */

/* Address of superblock in GFS2 basic blocks */
#define GFS2_SB_ADDR        128

/* The lock number for the superblock (must be zero) */
#define GFS2_SB_LOCK        0

/* Requirement:  GFS2_LOCKNAME_LEN % 8 == 0
   Includes: the fencing zero at the end */
#define GFS2_LOCKNAME_LEN   64

struct gfs2_sb {
    struct gfs2_meta_header sb_header;

    __be32 sb_fs_format;
    __be32 sb_multihost_format;
    __u32  __pad0;  /* Was superblock flags in gfs1 */

    __be32 sb_bsize;
    __be32 sb_bsize_shift;
    __u32 __pad1;   /* Was journal segment size in gfs1 */

    struct gfs2_inum sb_master_dir; /* Was jindex dinode in gfs1 */
    struct gfs2_inum __pad2; /* Was rindex dinode in gfs1 */
    struct gfs2_inum sb_root_dir;

    char sb_lockproto[GFS2_LOCKNAME_LEN];
    char sb_locktable[GFS2_LOCKNAME_LEN];

    struct gfs2_inum __pad3; /* Was quota inode in gfs1 */
    struct gfs2_inum __pad4; /* Was licence inode in gfs1 */
#define GFS2_HAS_UUID 1
    __u8 sb_uuid[16]; /* The UUID, maybe 0 for backwards compat */
};

/*
 * resource index structure
 */

struct gfs2_rindex {
    __be64 ri_addr; /* grp block disk address */
    __be32 ri_length;   /* length of rgrp header in fs blocks */
    __u32 __pad;

    __be64 ri_data0;    /* first data location */
    __be32 ri_data; /* num of data blocks in rgrp */

    __be32 ri_bitbytes; /* number of bytes in data bitmaps */

    __u8 ri_reserved[64];
};

/*
 * resource group header structure
 */

/* Number of blocks per byte in rgrp */
#define GFS2_NBBY       4
#define GFS2_BIT_SIZE       2
#define GFS2_BIT_MASK       0x00000003

#define GFS2_BLKST_FREE     0
#define GFS2_BLKST_USED     1
#define GFS2_BLKST_UNLINKED 2
#define GFS2_BLKST_DINODE   3

#define GFS2_RGF_JOURNAL    0x00000001
#define GFS2_RGF_METAONLY   0x00000002
#define GFS2_RGF_DATAONLY   0x00000004
#define GFS2_RGF_NOALLOC    0x00000008
#define GFS2_RGF_TRIMMED    0x00000010

struct gfs2_rgrp_lvb {
    __be32 rl_magic;
    __be32 rl_flags;
    __be32 rl_free;
    __be32 rl_dinodes;
    __be64 rl_igeneration;
    __be32 rl_unlinked;
    __be32 __pad;
};

struct gfs2_rgrp {
    struct gfs2_meta_header rg_header;

    __be32 rg_flags;
    __be32 rg_free;
    __be32 rg_dinodes;
    __be32 __pad;
    __be64 rg_igeneration;

    __u8 rg_reserved[80]; /* Several fields from gfs1 now reserved */
};

/*
 * quota structure
 */

struct gfs2_quota {
    __be64 qu_limit;
    __be64 qu_warn;
    __be64 qu_value;
    __u8 qu_reserved[64];
};

/*
 * dinode structure
 */

#define GFS2_MAX_META_HEIGHT    10
#define GFS2_DIR_MAX_DEPTH  17

#define DT2IF(dt) (((dt) << 12) & S_IFMT)
#define IF2DT(sif) (((sif) & S_IFMT) >> 12)

enum {
    gfs2fl_Jdata        = 0,
    gfs2fl_ExHash       = 1,
    gfs2fl_Unused       = 2,
    gfs2fl_EaIndirect   = 3,
    gfs2fl_Directio     = 4,
    gfs2fl_Immutable    = 5,
    gfs2fl_AppendOnly   = 6,
    gfs2fl_NoAtime      = 7,
    gfs2fl_Sync     = 8,
    gfs2fl_System       = 9,
    gfs2fl_TopLevel     = 10,
    gfs2fl_TruncInProg  = 29,
    gfs2fl_InheritDirectio  = 30,
    gfs2fl_InheritJdata = 31,
};

/* Dinode flags */
#define GFS2_DIF_JDATA          0x00000001
#define GFS2_DIF_EXHASH         0x00000002
#define GFS2_DIF_UNUSED         0x00000004  /* only in gfs1 */
#define GFS2_DIF_EA_INDIRECT        0x00000008
#define GFS2_DIF_DIRECTIO       0x00000010
#define GFS2_DIF_IMMUTABLE      0x00000020
#define GFS2_DIF_APPENDONLY     0x00000040
#define GFS2_DIF_NOATIME        0x00000080
#define GFS2_DIF_SYNC           0x00000100
#define GFS2_DIF_SYSTEM         0x00000200 /* New in gfs2 */
#define GFS2_DIF_TOPDIR         0x00000400 /* New in gfs2 */
#define GFS2_DIF_TRUNC_IN_PROG      0x20000000 /* New in gfs2 */
#define GFS2_DIF_INHERIT_DIRECTIO   0x40000000 /* only in gfs1 */
#define GFS2_DIF_INHERIT_JDATA      0x80000000

struct gfs2_dinode {
    struct gfs2_meta_header di_header;

    struct gfs2_inum di_num;

    __be32 di_mode; /* mode of file */
    __be32 di_uid;  /* owner's user id */
    __be32 di_gid;  /* owner's group id */
    __be32 di_nlink;    /* number of links to this file */
    __be64 di_size; /* number of bytes in file */
    __be64 di_blocks;   /* number of blocks in file */
    __be64 di_atime;    /* time last accessed */
    __be64 di_mtime;    /* time last modified */
    __be64 di_ctime;    /* time last changed */
    __be32 di_major;    /* device major number */
    __be32 di_minor;    /* device minor number */

    /* This section varies from gfs1. Padding added to align with
         * remainder of dinode
     */
    __be64 di_goal_meta;    /* rgrp to alloc from next */
    __be64 di_goal_data;    /* data block goal */
    __be64 di_generation;   /* generation number for NFS */

    __be32 di_flags;    /* GFS2_DIF_... */
    __be32 di_payload_format;  /* GFS2_FORMAT_... */
    __u16 __pad1;   /* Was ditype in gfs1 */
    __be16 di_height;   /* height of metadata */
    __u32 __pad2;   /* Unused incarnation number from gfs1 */

    /* These only apply to directories  */
    __u16 __pad3;   /* Padding */
    __be16 di_depth;    /* Number of bits in the table */
    __be32 di_entries;  /* The number of entries in the directory */

    struct gfs2_inum __pad4; /* Unused even in current gfs1 */

    __be64 di_eattr;    /* extended attribute block number */
    __be32 di_atime_nsec;   /* nsec portion of atime */
    __be32 di_mtime_nsec;   /* nsec portion of mtime */
    __be32 di_ctime_nsec;   /* nsec portion of ctime */

    __u8 di_reserved[44];
};

/*
 * directory structure - many of these per directory file
 */

#define GFS2_FNAMESIZE      255
#define GFS2_DIRENT_SIZE(name_len) ((sizeof(struct gfs2_dirent) + (name_len) + 7) & ~7)

struct gfs2_dirent {
    struct gfs2_inum de_inum;
    __be32 de_hash;
    __be16 de_rec_len;
    __be16 de_name_len;
    __be16 de_type;
    __u8 __pad[14];
};

/*
 * Header of leaf directory nodes
 */

struct gfs2_leaf {
    struct gfs2_meta_header lf_header;

    __be16 lf_depth;        /* Depth of leaf */
    __be16 lf_entries;      /* Number of dirents in leaf */
    __be32 lf_dirent_format;    /* Format of the dirents */
    __be64 lf_next;         /* Next leaf, if overflow */

    __u8 lf_reserved[64];
};

/*
 * Extended attribute header format
 *
 * This works in a similar way to dirents. There is a fixed size header
 * followed by a variable length section made up of the name and the
 * associated data. In the case of a "stuffed" entry, the value is
 * inline directly after the name, the ea_num_ptrs entry will be
 * zero in that case. For non-"stuffed" entries, there will be
 * a set of pointers (aligned to 8 byte boundary) to the block(s)
 * containing the value.
 *
 * The blocks containing the values and the blocks containing the
 * extended attribute headers themselves all start with the common
 * metadata header. Each inode, if it has extended attributes, will
 * have either a single block containing the extended attribute headers
 * or a single indirect block pointing to blocks containing the
 * extended attribure headers.
 *
 * The maximim size of the data part of an extended attribute is 64k
 * so the number of blocks required depends upon block size. Since the
 * block size also determines the number of pointers in an indirect
 * block, its a fairly complicated calculation to work out the maximum
 * number of blocks that an inode may have relating to extended attributes.
 *
 */

#define GFS2_EA_MAX_NAME_LEN    255
#define GFS2_EA_MAX_DATA_LEN    65536

#define GFS2_EATYPE_UNUSED  0
#define GFS2_EATYPE_USR     1
#define GFS2_EATYPE_SYS     2
#define GFS2_EATYPE_SECURITY    3

#define GFS2_EATYPE_LAST    3
#define GFS2_EATYPE_VALID(x)    ((x) <= GFS2_EATYPE_LAST)

#define GFS2_EAFLAG_LAST    0x01    /* last ea in block */

struct gfs2_ea_header {
    __be32 ea_rec_len;
    __be32 ea_data_len;
    __u8 ea_name_len;   /* no NULL pointer after the string */
    __u8 ea_type;       /* GFS2_EATYPE_... */
    __u8 ea_flags;      /* GFS2_EAFLAG_... */
    __u8 ea_num_ptrs;
    __u32 __pad;
};

/*
 * Log header structure
 */

#define GFS2_LOG_HEAD_UNMOUNT   0x00000001  /* log is clean */

struct gfs2_log_header {
    struct gfs2_meta_header lh_header;

    __be64 lh_sequence; /* Sequence number of this transaction */
    __be32 lh_flags;    /* GFS2_LOG_HEAD_... */
    __be32 lh_tail;     /* Block number of log tail */
    __be32 lh_blkno;
    __be32 lh_hash;
};

/*
 * Log type descriptor
 */

#define GFS2_LOG_DESC_METADATA  300
/* ld_data1 is the number of metadata blocks in the descriptor.
   ld_data2 is unused. */

#define GFS2_LOG_DESC_REVOKE    301
/* ld_data1 is the number of revoke blocks in the descriptor.
   ld_data2 is unused. */

#define GFS2_LOG_DESC_JDATA 302
/* ld_data1 is the number of data blocks in the descriptor.
   ld_data2 is unused. */

struct gfs2_log_descriptor {
    struct gfs2_meta_header ld_header;

    __be32 ld_type;     /* GFS2_LOG_DESC_... */
    __be32 ld_length;   /* Number of buffers in this chunk */
    __be32 ld_data1;    /* descriptor-specific field */
    __be32 ld_data2;    /* descriptor-specific field */

    __u8 ld_reserved[32];
};

/*
 * Inum Range
 * Describe a range of formal inode numbers allocated to
 * one machine to assign to inodes.
 */

#define GFS2_INUM_QUANTUM   1048576

struct gfs2_inum_range {
    __be64 ir_start;
    __be64 ir_length;
};

/*
 * Statfs change
 * Describes an change to the pool of free and allocated
 * blocks.
 */

struct gfs2_statfs_change {
    __be64 sc_total;
    __be64 sc_free;
    __be64 sc_dinodes;
};

/*
 * Quota change
 * Describes an allocation change for a particular
 * user or group.
 */

#define GFS2_QCF_USER       0x00000001

struct gfs2_quota_change {
    __be64 qc_change;
    __be32 qc_flags;    /* GFS2_QCF_... */
    __be32 qc_id;
};

struct gfs2_quota_lvb {
        __be32 qb_magic;
        __u32 __pad;
        __be64 qb_limit;      /* Hard limit of # blocks to alloc */
        __be64 qb_warn;       /* Warn user when alloc is above this # */
        __be64 qb_value;       /* Current # blocks allocated */
};

#endif /* __GFS2_ONDISK_DOT_H__ */