jfs_filsys.h

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/*
 *   Copyright (C) International Business Machines Corp., 2000-2003
 *
 *   This program is free software;  you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   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 02111-1307 USA
 */
#ifndef _H_JFS_FILSYS
#define _H_JFS_FILSYS

/*
 *  jfs_filsys.h
 *
 * file system (implementation-dependent) constants
 *
 * refer to <limits.h> for system wide implementation-dependent constants
 */

/*
 *   file system option (superblock flag)
 */

/* directory option */
#define JFS_UNICODE 0x00000001  /* unicode name */

/* mount time flags for error handling */
#define JFS_ERR_REMOUNT_RO 0x00000002   /* remount read-only */
#define JFS_ERR_CONTINUE   0x00000004   /* continue */
#define JFS_ERR_PANIC      0x00000008   /* panic */

/* Quota support */
#define JFS_USRQUOTA    0x00000010
#define JFS_GRPQUOTA    0x00000020

/* mount time flag to disable journaling to disk */
#define JFS_NOINTEGRITY 0x00000040

/* mount time flag to enable TRIM to ssd disks */
#define JFS_DISCARD     0x00000080

/* commit option */
#define JFS_COMMIT  0x00000f00  /* commit option mask */
#define JFS_GROUPCOMMIT 0x00000100  /* group (of 1) commit */
#define JFS_LAZYCOMMIT  0x00000200  /* lazy commit */
#define JFS_TMPFS   0x00000400  /* temporary file system -
                     * do not log/commit:
                     * Never implemented
                     */

/* log logical volume option */
#define JFS_INLINELOG   0x00000800  /* inline log within file system */
#define JFS_INLINEMOVE  0x00001000  /* inline log being moved */

/* Secondary aggregate inode table */
#define JFS_BAD_SAIT    0x00010000  /* current secondary ait is bad */

/* sparse regular file support */
#define JFS_SPARSE  0x00020000  /* sparse regular file */

/* DASD Limits      F226941 */
#define JFS_DASD_ENABLED 0x00040000 /* DASD limits enabled */
#define JFS_DASD_PRIME  0x00080000  /* Prime DASD usage on boot */

/* big endian flag */
#define JFS_SWAP_BYTES  0x00100000  /* running on big endian computer */

/* Directory index */
#define JFS_DIR_INDEX   0x00200000  /* Persistent index for */

/* platform options */
#define JFS_LINUX   0x10000000  /* Linux support */
#define JFS_DFS     0x20000000  /* DCE DFS LFS support */
/*  Never implemented */

#define JFS_OS2     0x40000000  /* OS/2 support */
/*  case-insensitive name/directory support */

#define JFS_AIX     0x80000000  /* AIX support */

/*
 *  buffer cache configuration
 */
/* page size */
#ifdef PSIZE
#undef PSIZE
#endif
#define PSIZE       4096    /* page size (in byte) */
#define L2PSIZE     12  /* log2(PSIZE) */
#define POFFSET     4095    /* offset within page */

/* buffer page size */
#define BPSIZE  PSIZE

/*
 *  fs fundamental size
 *
 * PSIZE >= file system block size >= PBSIZE >= DISIZE
 */
#define PBSIZE      512 /* physical block size (in byte) */
#define L2PBSIZE    9   /* log2(PBSIZE) */

#define DISIZE      512 /* on-disk inode size (in byte) */
#define L2DISIZE    9   /* log2(DISIZE) */

#define IDATASIZE   256 /* inode inline data size */
#define IXATTRSIZE  128 /* inode inline extended attribute size */

#define XTPAGE_SIZE 4096
#define log2_PAGESIZE   12

#define IAG_SIZE    4096
#define IAG_EXTENT_SIZE 4096
#define INOSPERIAG  4096    /* number of disk inodes per iag */
#define L2INOSPERIAG    12  /* l2 number of disk inodes per iag */
#define INOSPEREXT  32  /* number of disk inode per extent */
#define L2INOSPEREXT    5   /* l2 number of disk inode per extent */
#define IXSIZE      (DISIZE * INOSPEREXT)   /* inode extent size */
#define INOSPERPAGE 8   /* number of disk inodes per 4K page */
#define L2INOSPERPAGE   3   /* log2(INOSPERPAGE) */

#define IAGFREELIST_LWM 64

#define INODE_EXTENT_SIZE   IXSIZE  /* inode extent size */
#define NUM_INODE_PER_EXTENT    INOSPEREXT
#define NUM_INODE_PER_IAG   INOSPERIAG

#define MINBLOCKSIZE        512
#define MAXBLOCKSIZE        4096
#define MAXFILESIZE     ((s64)1 << 52)

#define JFS_LINK_MAX        0xffffffff

/* Minimum number of bytes supported for a JFS partition */
#define MINJFS          (0x1000000)
#define MINJFSTEXT      "16"

/*
 * file system block size -> physical block size
 */
#define LBOFFSET(x) ((x) & (PBSIZE - 1))
#define LBNUMBER(x) ((x) >> L2PBSIZE)
#define LBLK2PBLK(sb,b) ((b) << (sb->s_blocksize_bits - L2PBSIZE))
#define PBLK2LBLK(sb,b) ((b) >> (sb->s_blocksize_bits - L2PBSIZE))
/* size in byte -> last page number */
#define SIZE2PN(size)   ( ((s64)((size) - 1)) >> (L2PSIZE) )
/* size in byte -> last file system block number */
#define SIZE2BN(size, l2bsize) ( ((s64)((size) - 1)) >> (l2bsize) )

/*
 * fixed physical block address (physical block size = 512 byte)
 *
 * NOTE: since we can't guarantee a physical block size of 512 bytes the use of
 *   these macros should be removed and the byte offset macros used instead.
 */
#define SUPER1_B    64  /* primary superblock */
#define AIMAP_B     (SUPER1_B + 8)  /* 1st extent of aggregate inode map */
#define AITBL_B     (AIMAP_B + 16)  /*
                     * 1st extent of aggregate inode table
                     */
#define SUPER2_B    (AITBL_B + 32)  /* 2ndary superblock pbn */
#define BMAP_B      (SUPER2_B + 8)  /* block allocation map */

/*
 * SIZE_OF_SUPER defines the total amount of space reserved on disk for the
 * superblock.  This is not the same as the superblock structure, since all of
 * this space is not currently being used.
 */
#define SIZE_OF_SUPER   PSIZE

/*
 * SIZE_OF_AG_TABLE defines the amount of space reserved to hold the AG table
 */
#define SIZE_OF_AG_TABLE    PSIZE

/*
 * SIZE_OF_MAP_PAGE defines the amount of disk space reserved for each page of
 * the inode allocation map (to hold iag)
 */
#define SIZE_OF_MAP_PAGE    PSIZE

/*
 * fixed byte offset address
 */
#define SUPER1_OFF  0x8000  /* primary superblock */
#define AIMAP_OFF   (SUPER1_OFF + SIZE_OF_SUPER)
                    /*
                     * Control page of aggregate inode map
                     * followed by 1st extent of map
                     */
#define AITBL_OFF   (AIMAP_OFF + (SIZE_OF_MAP_PAGE << 1))
                    /*
                     * 1st extent of aggregate inode table
                     */
#define SUPER2_OFF  (AITBL_OFF + INODE_EXTENT_SIZE)
                    /*
                     * secondary superblock
                     */
#define BMAP_OFF    (SUPER2_OFF + SIZE_OF_SUPER)
                    /*
                     * block allocation map
                     */

/*
 * The following macro is used to indicate the number of reserved disk blocks at
 * the front of an aggregate, in terms of physical blocks.  This value is
 * currently defined to be 32K.  This turns out to be the same as the primary
 * superblock's address, since it directly follows the reserved blocks.
 */
#define AGGR_RSVD_BLOCKS    SUPER1_B

/*
 * The following macro is used to indicate the number of reserved bytes at the
 * front of an aggregate.  This value is currently defined to be 32K.  This
 * turns out to be the same as the primary superblock's byte offset, since it
 * directly follows the reserved blocks.
 */
#define AGGR_RSVD_BYTES SUPER1_OFF

/*
 * The following macro defines the byte offset for the first inode extent in
 * the aggregate inode table.  This allows us to find the self inode to find the
 * rest of the table.  Currently this value is 44K.
 */
#define AGGR_INODE_TABLE_START  AITBL_OFF

/*
 *  fixed reserved inode number
 */
/* aggregate inode */
#define AGGR_RESERVED_I 0   /* aggregate inode (reserved) */
#define AGGREGATE_I 1   /* aggregate inode map inode */
#define BMAP_I      2   /* aggregate block allocation map inode */
#define LOG_I       3   /* aggregate inline log inode */
#define BADBLOCK_I  4   /* aggregate bad block inode */
#define FILESYSTEM_I    16  /* 1st/only fileset inode in ait:
                 * fileset inode map inode
                 */

/* per fileset inode */
#define FILESET_RSVD_I  0   /* fileset inode (reserved) */
#define FILESET_EXT_I   1   /* fileset inode extension */
#define ROOT_I      2   /* fileset root inode */
#define ACL_I       3   /* fileset ACL inode */

#define FILESET_OBJECT_I 4  /* the first fileset inode available for a file
                 * or directory or link...
                 */
#define FIRST_FILESET_INO 16    /* the first aggregate inode which describes
                 * an inode.  (To fsck this is also the first
                 * inode in part 2 of the agg inode table.)
                 */

/*
 *  directory configuration
 */
#define JFS_NAME_MAX    255
#define JFS_PATH_MAX    BPSIZE


/*
 *  file system state (superblock state)
 */
#define FM_CLEAN 0x00000000 /* file system is unmounted and clean */
#define FM_MOUNT 0x00000001 /* file system is mounted cleanly */
#define FM_DIRTY 0x00000002 /* file system was not unmounted and clean
                 * when mounted or
                 * commit failure occurred while being mounted:
                 * fsck() must be run to repair
                 */
#define FM_LOGREDO 0x00000004   /* log based recovery (logredo()) failed:
                 * fsck() must be run to repair
                 */
#define FM_EXTENDFS 0x00000008  /* file system extendfs() in progress */

#endif              /* _H_JFS_FILSYS */