jfs_dmap.h

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/*
 *   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_agheight; /* 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_agheight;    /* 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_agheight db_bmap.dn_agheight
#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);
extern s64 dbDiscardAG(struct inode *ip, int agno, s64 minlen);

#endif              /* _H_JFS_DMAP */