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root/include/linux/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__

#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

/* 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;
        __be32 __pad1;          /* Was incarnation number in gfs1 */
};

/*
 * 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

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 linked list: user quotas and group quotas form two separate 
 * singly linked lists. ll_next stores uids or gids of next quotas in the 
 * linked list.

Given the uid/gid, how to calculate the quota file offsets for the corresponding
gfs2_quota structures on disk:

for user quotas, given uid,
offset = uid * sizeof(struct gfs2_quota);

for group quotas, given gid,
offset = (gid * sizeof(struct gfs2_quota)) + sizeof(struct gfs2_quota);


  uid:0   gid:0       uid:12   gid:12      uid:17   gid:17     uid:5142 gid:5142
+-------+-------+    +-------+-------+    +-------+- - - -+    +- - - -+-------+
| valid | valid | :: | valid | valid | :: | valid | inval | :: | inval | valid |
+-------+-------+    +-------+-------+    +-------+- - - -+    +- - - -+-------+
next:12   next:12    next:17 next:5142    next:NULL                    next:NULL
    |       |            |       |            |<-- user quota list         |
     \______|___________/ \______|___________/         group quota list -->|
            |                    |                                         |
             \__________________/ \_______________________________________/

*/

/*
 * quota structure
 */

struct gfs2_quota {
        __be64 qu_limit;
        __be64 qu_warn;
        __be64 qu_value;
        __be32 qu_ll_next; /* location of next quota in list */
        __u8 qu_reserved[60];
};

/*
 * 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_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_TRUNC_IN_PROG          0x20000000 /* New in gfs2 */
#define GFS2_DIF_INHERIT_DIRECTIO       0x40000000
#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
 */

#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__ */

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