alistair23-linux/include/linux/gfs2_ondisk.h

/*
 * 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

/* 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
 *
 * 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__ */