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root/fs/jfs/jfs_dmap.h

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INCLUDED FROM


DEFINITIONS

This source file includes following definitions.
  1. TREEMAX

/*
 *   Copyright (C) International Business Machines Corp., 2000-2002
 *
 *   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_DMAP
#define _H_JFS_DMAP

#include "jfs_txnmgr.h"

#define BMAPVERSION     1       /* version number */
#define TREESIZE        (256+64+16+4+1) /* size of a dmap tree */
#define LEAFIND         (64+16+4+1)     /* index of 1st leaf of a dmap tree */
#define LPERDMAP        256     /* num leaves per dmap tree */
#define L2LPERDMAP      8       /* l2 number of leaves per dmap tree */
#define DBWORD          32      /* # of blks covered by a map word */
#define L2DBWORD        5       /* l2 # of blks covered by a mword */
#define BUDMIN          L2DBWORD        /* max free string in a map word */
#define BPERDMAP        (LPERDMAP * DBWORD)     /* num of blks per dmap */
#define L2BPERDMAP      13      /* l2 num of blks per dmap */
#define CTLTREESIZE     (1024+256+64+16+4+1)    /* size of a dmapctl tree */
#define CTLLEAFIND      (256+64+16+4+1) /* idx of 1st leaf of a dmapctl tree */
#define LPERCTL         1024    /* num of leaves per dmapctl tree */
#define L2LPERCTL       10      /* l2 num of leaves per dmapctl tree */
#define ROOT            0       /* index of the root of a tree */
#define NOFREE          ((s8) -1)       /* no blocks free */
#define MAXAG           128     /* max number of allocation groups */
#define L2MAXAG         7       /* l2 max num of AG */
#define L2MINAGSZ       25      /* l2 of minimum AG size in bytes */
#define BMAPBLKNO       0       /* lblkno of bmap within the map */

/*
 * maximum l2 number of disk blocks at the various dmapctl levels.
 */
#define L2MAXL0SIZE     (L2BPERDMAP + 1 * L2LPERCTL)
#define L2MAXL1SIZE     (L2BPERDMAP + 2 * L2LPERCTL)
#define L2MAXL2SIZE     (L2BPERDMAP + 3 * L2LPERCTL)

/*
 * maximum number of disk blocks at the various dmapctl levels.
 */
#define MAXL0SIZE       ((s64)1 << L2MAXL0SIZE)
#define MAXL1SIZE       ((s64)1 << L2MAXL1SIZE)
#define MAXL2SIZE       ((s64)1 << L2MAXL2SIZE)

#define MAXMAPSIZE      MAXL2SIZE       /* maximum aggregate map size */

/*
 * determine the maximum free string for four (lower level) nodes
 * of the tree.
 */
static inline signed char TREEMAX(signed char *cp)
{
        signed char tmp1, tmp2;

        tmp1 = max(*(cp+2), *(cp+3));
        tmp2 = max(*(cp), *(cp+1));

        return max(tmp1, tmp2);
}

/*
 * convert disk block number to the logical block number of the dmap
 * describing the disk block.  s is the log2(number of logical blocks per page)
 *
 * The calculation figures out how many logical pages are in front of the dmap.
 *      - the number of dmaps preceding it
 *      - the number of L0 pages preceding its L0 page
 *      - the number of L1 pages preceding its L1 page
 *      - 3 is added to account for the L2, L1, and L0 page for this dmap
 *      - 1 is added to account for the control page of the map.
 */
#define BLKTODMAP(b,s)    \
        ((((b) >> 13) + ((b) >> 23) + ((b) >> 33) + 3 + 1) << (s))

/*
 * convert disk block number to the logical block number of the LEVEL 0
 * dmapctl describing the disk block.  s is the log2(number of logical blocks
 * per page)
 *
 * The calculation figures out how many logical pages are in front of the L0.
 *      - the number of dmap pages preceding it
 *      - the number of L0 pages preceding it
 *      - the number of L1 pages preceding its L1 page
 *      - 2 is added to account for the L2, and L1 page for this L0
 *      - 1 is added to account for the control page of the map.
 */
#define BLKTOL0(b,s)      \
        (((((b) >> 23) << 10) + ((b) >> 23) + ((b) >> 33) + 2 + 1) << (s))

/*
 * convert disk block number to the logical block number of the LEVEL 1
 * dmapctl describing the disk block.  s is the log2(number of logical blocks
 * per page)
 *
 * The calculation figures out how many logical pages are in front of the L1.
 *      - the number of dmap pages preceding it
 *      - the number of L0 pages preceding it
 *      - the number of L1 pages preceding it
 *      - 1 is added to account for the L2 page
 *      - 1 is added to account for the control page of the map.
 */
#define BLKTOL1(b,s)      \
     (((((b) >> 33) << 20) + (((b) >> 33) << 10) + ((b) >> 33) + 1 + 1) << (s))

/*
 * convert disk block number to the logical block number of the dmapctl
 * at the specified level which describes the disk block.
 */
#define BLKTOCTL(b,s,l)   \
        (((l) == 2) ? 1 : ((l) == 1) ? BLKTOL1((b),(s)) : BLKTOL0((b),(s)))

/*
 * convert aggregate map size to the zero origin dmapctl level of the
 * top dmapctl.
 */
#define BMAPSZTOLEV(size)       \
        (((size) <= MAXL0SIZE) ? 0 : ((size) <= MAXL1SIZE) ? 1 : 2)

/* convert disk block number to allocation group number.
 */
#define BLKTOAG(b,sbi)  ((b) >> ((sbi)->bmap->db_agl2size))

/* convert allocation group number to starting disk block
 * number.
 */
#define AGTOBLK(a,ip)   \
        ((s64)(a) << (JFS_SBI((ip)->i_sb)->bmap->db_agl2size))

/*
 *      dmap summary tree
 *
 * dmaptree must be consistent with dmapctl.
 */
struct dmaptree {
        __le32 nleafs;          /* 4: number of tree leafs      */
        __le32 l2nleafs;        /* 4: l2 number of tree leafs   */
        __le32 leafidx;         /* 4: index of first tree leaf  */
        __le32 height;          /* 4: height of the tree        */
        s8 budmin;              /* 1: min l2 tree leaf value to combine */
        s8 stree[TREESIZE];     /* TREESIZE: tree               */
        u8 pad[2];              /* 2: pad to word boundary      */
};                              /* - 360 -                      */

/*
 *      dmap page per 8K blocks bitmap
 */
struct dmap {
        __le32 nblocks;         /* 4: num blks covered by this dmap     */
        __le32 nfree;           /* 4: num of free blks in this dmap     */
        __le64 start;           /* 8: starting blkno for this dmap      */
        struct dmaptree tree;   /* 360: dmap tree                       */
        u8 pad[1672];           /* 1672: pad to 2048 bytes              */
        __le32 wmap[LPERDMAP];  /* 1024: bits of the working map        */
        __le32 pmap[LPERDMAP];  /* 1024: bits of the persistent map     */
};                              /* - 4096 -                             */

/*
 *      disk map control page per level.
 *
 * dmapctl must be consistent with dmaptree.
 */
struct dmapctl {
        __le32 nleafs;          /* 4: number of tree leafs      */
        __le32 l2nleafs;        /* 4: l2 number of tree leafs   */
        __le32 leafidx;         /* 4: index of the first tree leaf      */
        __le32 height;          /* 4: height of tree            */
        s8 budmin;              /* 1: minimum l2 tree leaf value        */
        s8 stree[CTLTREESIZE];  /* CTLTREESIZE: dmapctl tree    */
        u8 pad[2714];           /* 2714: pad to 4096            */
};                              /* - 4096 -                     */

/*
 *      common definition for dmaptree within dmap and dmapctl
 */
typedef union dmtree {
        struct dmaptree t1;
        struct dmapctl t2;
} dmtree_t;

/* macros for accessing fields within dmtree */
#define dmt_nleafs      t1.nleafs
#define dmt_l2nleafs    t1.l2nleafs
#define dmt_leafidx     t1.leafidx
#define dmt_height      t1.height
#define dmt_budmin      t1.budmin
#define dmt_stree       t1.stree

/*
 *      on-disk aggregate disk allocation map descriptor.
 */
struct dbmap_disk {
        __le64 dn_mapsize;      /* 8: number of blocks in aggregate     */
        __le64 dn_nfree;        /* 8: num free blks in aggregate map    */
        __le32 dn_l2nbperpage;  /* 4: number of blks per page           */
        __le32 dn_numag;        /* 4: total number of ags               */
        __le32 dn_maxlevel;     /* 4: number of active ags              */
        __le32 dn_maxag;        /* 4: max active alloc group number     */
        __le32 dn_agpref;       /* 4: preferred alloc group (hint)      */
        __le32 dn_aglevel;      /* 4: dmapctl level holding the AG      */
        __le32 dn_agheigth;     /* 4: height in dmapctl of the AG       */
        __le32 dn_agwidth;      /* 4: width in dmapctl of the AG        */
        __le32 dn_agstart;      /* 4: start tree index at AG height     */
        __le32 dn_agl2size;     /* 4: l2 num of blks per alloc group    */
        __le64 dn_agfree[MAXAG];/* 8*MAXAG: per AG free count           */
        __le64 dn_agsize;       /* 8: num of blks per alloc group       */
        s8 dn_maxfreebud;       /* 1: max free buddy system             */
        u8 pad[3007];           /* 3007: pad to 4096                    */
};                              /* - 4096 -                             */

struct dbmap {
        s64 dn_mapsize;         /* number of blocks in aggregate        */
        s64 dn_nfree;           /* num free blks in aggregate map       */
        int dn_l2nbperpage;     /* number of blks per page              */
        int dn_numag;           /* total number of ags                  */
        int dn_maxlevel;        /* number of active ags                 */
        int dn_maxag;           /* max active alloc group number        */
        int dn_agpref;          /* preferred alloc group (hint)         */
        int dn_aglevel;         /* dmapctl level holding the AG         */
        int dn_agheigth;        /* height in dmapctl of the AG          */
        int dn_agwidth;         /* width in dmapctl of the AG           */
        int dn_agstart;         /* start tree index at AG height        */
        int dn_agl2size;        /* l2 num of blks per alloc group       */
        s64 dn_agfree[MAXAG];   /* per AG free count                    */
        s64 dn_agsize;          /* num of blks per alloc group          */
        signed char dn_maxfreebud;      /* max free buddy system        */
};                              /* - 4096 -                             */
/*
 *      in-memory aggregate disk allocation map descriptor.
 */
struct bmap {
        struct dbmap db_bmap;           /* on-disk aggregate map descriptor */
        struct inode *db_ipbmap;        /* ptr to aggregate map incore inode */
        struct mutex db_bmaplock;       /* aggregate map lock */
        atomic_t db_active[MAXAG];      /* count of active, open files in AG */
        u32 *db_DBmap;
};

/* macros for accessing fields within in-memory aggregate map descriptor */
#define db_mapsize      db_bmap.dn_mapsize
#define db_nfree        db_bmap.dn_nfree
#define db_agfree       db_bmap.dn_agfree
#define db_agsize       db_bmap.dn_agsize
#define db_agl2size     db_bmap.dn_agl2size
#define db_agwidth      db_bmap.dn_agwidth
#define db_agheigth     db_bmap.dn_agheigth
#define db_agstart      db_bmap.dn_agstart
#define db_numag        db_bmap.dn_numag
#define db_maxlevel     db_bmap.dn_maxlevel
#define db_aglevel      db_bmap.dn_aglevel
#define db_agpref       db_bmap.dn_agpref
#define db_maxag        db_bmap.dn_maxag
#define db_maxfreebud   db_bmap.dn_maxfreebud
#define db_l2nbperpage  db_bmap.dn_l2nbperpage

/*
 * macros for various conversions needed by the allocators.
 * blkstol2(), cntlz(), and cnttz() are operating system dependent functions.
 */
/* convert number of blocks to log2 number of blocks, rounding up to
 * the next log2 value if blocks is not a l2 multiple.
 */
#define BLKSTOL2(d)             (blkstol2(d))

/* convert number of leafs to log2 leaf value */
#define NLSTOL2BSZ(n)           (31 - cntlz((n)) + BUDMIN)

/* convert leaf index to log2 leaf value */
#define LITOL2BSZ(n,m,b)        ((((n) == 0) ? (m) : cnttz((n))) + (b))

/* convert a block number to a dmap control leaf index */
#define BLKTOCTLLEAF(b,m)       \
        (((b) & (((s64)1 << ((m) + L2LPERCTL)) - 1)) >> (m))

/* convert log2 leaf value to buddy size */
#define BUDSIZE(s,m)            (1 << ((s) - (m)))

/*
 *      external references.
 */
extern int dbMount(struct inode *ipbmap);

extern int dbUnmount(struct inode *ipbmap, int mounterror);

extern int dbFree(struct inode *ipbmap, s64 blkno, s64 nblocks);

extern int dbUpdatePMap(struct inode *ipbmap,
                        int free, s64 blkno, s64 nblocks, struct tblock * tblk);

extern int dbNextAG(struct inode *ipbmap);

extern int dbAlloc(struct inode *ipbmap, s64 hint, s64 nblocks, s64 * results);

extern int dbReAlloc(struct inode *ipbmap,
                     s64 blkno, s64 nblocks, s64 addnblocks, s64 * results);

extern int dbSync(struct inode *ipbmap);
extern int dbAllocBottomUp(struct inode *ip, s64 blkno, s64 nblocks);
extern int dbExtendFS(struct inode *ipbmap, s64 blkno, s64 nblocks);
extern void dbFinalizeBmap(struct inode *ipbmap);
extern s64 dbMapFileSizeToMapSize(struct inode *ipbmap);
#endif                          /* _H_JFS_DMAP */

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