linux/fs/jfs/jfs_dmap.h
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   1/*
   2 *   Copyright (C) International Business Machines Corp., 2000-2002
   3 *
   4 *   This program is free software;  you can redistribute it and/or modify
   5 *   it under the terms of the GNU General Public License as published by
   6 *   the Free Software Foundation; either version 2 of the License, or
   7 *   (at your option) any later version.
   8 *
   9 *   This program is distributed in the hope that it will be useful,
  10 *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
  11 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
  12 *   the GNU General Public License for more details.
  13 *
  14 *   You should have received a copy of the GNU General Public License
  15 *   along with this program;  if not, write to the Free Software
  16 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  17 */
  18#ifndef _H_JFS_DMAP
  19#define _H_JFS_DMAP
  20
  21#include "jfs_txnmgr.h"
  22
  23#define BMAPVERSION     1       /* version number */
  24#define TREESIZE        (256+64+16+4+1) /* size of a dmap tree */
  25#define LEAFIND         (64+16+4+1)     /* index of 1st leaf of a dmap tree */
  26#define LPERDMAP        256     /* num leaves per dmap tree */
  27#define L2LPERDMAP      8       /* l2 number of leaves per dmap tree */
  28#define DBWORD          32      /* # of blks covered by a map word */
  29#define L2DBWORD        5       /* l2 # of blks covered by a mword */
  30#define BUDMIN          L2DBWORD        /* max free string in a map word */
  31#define BPERDMAP        (LPERDMAP * DBWORD)     /* num of blks per dmap */
  32#define L2BPERDMAP      13      /* l2 num of blks per dmap */
  33#define CTLTREESIZE     (1024+256+64+16+4+1)    /* size of a dmapctl tree */
  34#define CTLLEAFIND      (256+64+16+4+1) /* idx of 1st leaf of a dmapctl tree */
  35#define LPERCTL         1024    /* num of leaves per dmapctl tree */
  36#define L2LPERCTL       10      /* l2 num of leaves per dmapctl tree */
  37#define ROOT            0       /* index of the root of a tree */
  38#define NOFREE          ((s8) -1)       /* no blocks free */
  39#define MAXAG           128     /* max number of allocation groups */
  40#define L2MAXAG         7       /* l2 max num of AG */
  41#define L2MINAGSZ       25      /* l2 of minimum AG size in bytes */
  42#define BMAPBLKNO       0       /* lblkno of bmap within the map */
  43
  44/*
  45 * maximum l2 number of disk blocks at the various dmapctl levels.
  46 */
  47#define L2MAXL0SIZE     (L2BPERDMAP + 1 * L2LPERCTL)
  48#define L2MAXL1SIZE     (L2BPERDMAP + 2 * L2LPERCTL)
  49#define L2MAXL2SIZE     (L2BPERDMAP + 3 * L2LPERCTL)
  50
  51/*
  52 * maximum number of disk blocks at the various dmapctl levels.
  53 */
  54#define MAXL0SIZE       ((s64)1 << L2MAXL0SIZE)
  55#define MAXL1SIZE       ((s64)1 << L2MAXL1SIZE)
  56#define MAXL2SIZE       ((s64)1 << L2MAXL2SIZE)
  57
  58#define MAXMAPSIZE      MAXL2SIZE       /* maximum aggregate map size */
  59
  60/*
  61 * determine the maximum free string for four (lower level) nodes
  62 * of the tree.
  63 */
  64static inline signed char TREEMAX(signed char *cp)
  65{
  66        signed char tmp1, tmp2;
  67
  68        tmp1 = max(*(cp+2), *(cp+3));
  69        tmp2 = max(*(cp), *(cp+1));
  70
  71        return max(tmp1, tmp2);
  72}
  73
  74/*
  75 * convert disk block number to the logical block number of the dmap
  76 * describing the disk block.  s is the log2(number of logical blocks per page)
  77 *
  78 * The calculation figures out how many logical pages are in front of the dmap.
  79 *      - the number of dmaps preceding it
  80 *      - the number of L0 pages preceding its L0 page
  81 *      - the number of L1 pages preceding its L1 page
  82 *      - 3 is added to account for the L2, L1, and L0 page for this dmap
  83 *      - 1 is added to account for the control page of the map.
  84 */
  85#define BLKTODMAP(b,s)    \
  86        ((((b) >> 13) + ((b) >> 23) + ((b) >> 33) + 3 + 1) << (s))
  87
  88/*
  89 * convert disk block number to the logical block number of the LEVEL 0
  90 * dmapctl describing the disk block.  s is the log2(number of logical blocks
  91 * per page)
  92 *
  93 * The calculation figures out how many logical pages are in front of the L0.
  94 *      - the number of dmap pages preceding it
  95 *      - the number of L0 pages preceding it
  96 *      - the number of L1 pages preceding its L1 page
  97 *      - 2 is added to account for the L2, and L1 page for this L0
  98 *      - 1 is added to account for the control page of the map.
  99 */
 100#define BLKTOL0(b,s)      \
 101        (((((b) >> 23) << 10) + ((b) >> 23) + ((b) >> 33) + 2 + 1) << (s))
 102
 103/*
 104 * convert disk block number to the logical block number of the LEVEL 1
 105 * dmapctl describing the disk block.  s is the log2(number of logical blocks
 106 * per page)
 107 *
 108 * The calculation figures out how many logical pages are in front of the L1.
 109 *      - the number of dmap pages preceding it
 110 *      - the number of L0 pages preceding it
 111 *      - the number of L1 pages preceding it
 112 *      - 1 is added to account for the L2 page
 113 *      - 1 is added to account for the control page of the map.
 114 */
 115#define BLKTOL1(b,s)      \
 116     (((((b) >> 33) << 20) + (((b) >> 33) << 10) + ((b) >> 33) + 1 + 1) << (s))
 117
 118/*
 119 * convert disk block number to the logical block number of the dmapctl
 120 * at the specified level which describes the disk block.
 121 */
 122#define BLKTOCTL(b,s,l)   \
 123        (((l) == 2) ? 1 : ((l) == 1) ? BLKTOL1((b),(s)) : BLKTOL0((b),(s)))
 124
 125/*
 126 * convert aggregate map size to the zero origin dmapctl level of the
 127 * top dmapctl.
 128 */
 129#define BMAPSZTOLEV(size)       \
 130        (((size) <= MAXL0SIZE) ? 0 : ((size) <= MAXL1SIZE) ? 1 : 2)
 131
 132/* convert disk block number to allocation group number.
 133 */
 134#define BLKTOAG(b,sbi)  ((b) >> ((sbi)->bmap->db_agl2size))
 135
 136/* convert allocation group number to starting disk block
 137 * number.
 138 */
 139#define AGTOBLK(a,ip)   \
 140        ((s64)(a) << (JFS_SBI((ip)->i_sb)->bmap->db_agl2size))
 141
 142/*
 143 *      dmap summary tree
 144 *
 145 * dmaptree must be consistent with dmapctl.
 146 */
 147struct dmaptree {
 148        __le32 nleafs;          /* 4: number of tree leafs      */
 149        __le32 l2nleafs;        /* 4: l2 number of tree leafs   */
 150        __le32 leafidx;         /* 4: index of first tree leaf  */
 151        __le32 height;          /* 4: height of the tree        */
 152        s8 budmin;              /* 1: min l2 tree leaf value to combine */
 153        s8 stree[TREESIZE];     /* TREESIZE: tree               */
 154        u8 pad[2];              /* 2: pad to word boundary      */
 155};                              /* - 360 -                      */
 156
 157/*
 158 *      dmap page per 8K blocks bitmap
 159 */
 160struct dmap {
 161        __le32 nblocks;         /* 4: num blks covered by this dmap     */
 162        __le32 nfree;           /* 4: num of free blks in this dmap     */
 163        __le64 start;           /* 8: starting blkno for this dmap      */
 164        struct dmaptree tree;   /* 360: dmap tree                       */
 165        u8 pad[1672];           /* 1672: pad to 2048 bytes              */
 166        __le32 wmap[LPERDMAP];  /* 1024: bits of the working map        */
 167        __le32 pmap[LPERDMAP];  /* 1024: bits of the persistent map     */
 168};                              /* - 4096 -                             */
 169
 170/*
 171 *      disk map control page per level.
 172 *
 173 * dmapctl must be consistent with dmaptree.
 174 */
 175struct dmapctl {
 176        __le32 nleafs;          /* 4: number of tree leafs      */
 177        __le32 l2nleafs;        /* 4: l2 number of tree leafs   */
 178        __le32 leafidx;         /* 4: index of the first tree leaf      */
 179        __le32 height;          /* 4: height of tree            */
 180        s8 budmin;              /* 1: minimum l2 tree leaf value        */
 181        s8 stree[CTLTREESIZE];  /* CTLTREESIZE: dmapctl tree    */
 182        u8 pad[2714];           /* 2714: pad to 4096            */
 183};                              /* - 4096 -                     */
 184
 185/*
 186 *      common definition for dmaptree within dmap and dmapctl
 187 */
 188typedef union dmtree {
 189        struct dmaptree t1;
 190        struct dmapctl t2;
 191} dmtree_t;
 192
 193/* macros for accessing fields within dmtree */
 194#define dmt_nleafs      t1.nleafs
 195#define dmt_l2nleafs    t1.l2nleafs
 196#define dmt_leafidx     t1.leafidx
 197#define dmt_height      t1.height
 198#define dmt_budmin      t1.budmin
 199#define dmt_stree       t1.stree
 200
 201/*
 202 *      on-disk aggregate disk allocation map descriptor.
 203 */
 204struct dbmap_disk {
 205        __le64 dn_mapsize;      /* 8: number of blocks in aggregate     */
 206        __le64 dn_nfree;        /* 8: num free blks in aggregate map    */
 207        __le32 dn_l2nbperpage;  /* 4: number of blks per page           */
 208        __le32 dn_numag;        /* 4: total number of ags               */
 209        __le32 dn_maxlevel;     /* 4: number of active ags              */
 210        __le32 dn_maxag;        /* 4: max active alloc group number     */
 211        __le32 dn_agpref;       /* 4: preferred alloc group (hint)      */
 212        __le32 dn_aglevel;      /* 4: dmapctl level holding the AG      */
 213        __le32 dn_agheight;     /* 4: height in dmapctl of the AG       */
 214        __le32 dn_agwidth;      /* 4: width in dmapctl of the AG        */
 215        __le32 dn_agstart;      /* 4: start tree index at AG height     */
 216        __le32 dn_agl2size;     /* 4: l2 num of blks per alloc group    */
 217        __le64 dn_agfree[MAXAG];/* 8*MAXAG: per AG free count           */
 218        __le64 dn_agsize;       /* 8: num of blks per alloc group       */
 219        s8 dn_maxfreebud;       /* 1: max free buddy system             */
 220        u8 pad[3007];           /* 3007: pad to 4096                    */
 221};                              /* - 4096 -                             */
 222
 223struct dbmap {
 224        s64 dn_mapsize;         /* number of blocks in aggregate        */
 225        s64 dn_nfree;           /* num free blks in aggregate map       */
 226        int dn_l2nbperpage;     /* number of blks per page              */
 227        int dn_numag;           /* total number of ags                  */
 228        int dn_maxlevel;        /* number of active ags                 */
 229        int dn_maxag;           /* max active alloc group number        */
 230        int dn_agpref;          /* preferred alloc group (hint)         */
 231        int dn_aglevel;         /* dmapctl level holding the AG         */
 232        int dn_agheight;        /* height in dmapctl of the AG          */
 233        int dn_agwidth;         /* width in dmapctl of the AG           */
 234        int dn_agstart;         /* start tree index at AG height        */
 235        int dn_agl2size;        /* l2 num of blks per alloc group       */
 236        s64 dn_agfree[MAXAG];   /* per AG free count                    */
 237        s64 dn_agsize;          /* num of blks per alloc group          */
 238        signed char dn_maxfreebud;      /* max free buddy system        */
 239};                              /* - 4096 -                             */
 240/*
 241 *      in-memory aggregate disk allocation map descriptor.
 242 */
 243struct bmap {
 244        struct dbmap db_bmap;           /* on-disk aggregate map descriptor */
 245        struct inode *db_ipbmap;        /* ptr to aggregate map incore inode */
 246        struct mutex db_bmaplock;       /* aggregate map lock */
 247        atomic_t db_active[MAXAG];      /* count of active, open files in AG */
 248        u32 *db_DBmap;
 249};
 250
 251/* macros for accessing fields within in-memory aggregate map descriptor */
 252#define db_mapsize      db_bmap.dn_mapsize
 253#define db_nfree        db_bmap.dn_nfree
 254#define db_agfree       db_bmap.dn_agfree
 255#define db_agsize       db_bmap.dn_agsize
 256#define db_agl2size     db_bmap.dn_agl2size
 257#define db_agwidth      db_bmap.dn_agwidth
 258#define db_agheight     db_bmap.dn_agheight
 259#define db_agstart      db_bmap.dn_agstart
 260#define db_numag        db_bmap.dn_numag
 261#define db_maxlevel     db_bmap.dn_maxlevel
 262#define db_aglevel      db_bmap.dn_aglevel
 263#define db_agpref       db_bmap.dn_agpref
 264#define db_maxag        db_bmap.dn_maxag
 265#define db_maxfreebud   db_bmap.dn_maxfreebud
 266#define db_l2nbperpage  db_bmap.dn_l2nbperpage
 267
 268/*
 269 * macros for various conversions needed by the allocators.
 270 * blkstol2(), cntlz(), and cnttz() are operating system dependent functions.
 271 */
 272/* convert number of blocks to log2 number of blocks, rounding up to
 273 * the next log2 value if blocks is not a l2 multiple.
 274 */
 275#define BLKSTOL2(d)             (blkstol2(d))
 276
 277/* convert number of leafs to log2 leaf value */
 278#define NLSTOL2BSZ(n)           (31 - cntlz((n)) + BUDMIN)
 279
 280/* convert leaf index to log2 leaf value */
 281#define LITOL2BSZ(n,m,b)        ((((n) == 0) ? (m) : cnttz((n))) + (b))
 282
 283/* convert a block number to a dmap control leaf index */
 284#define BLKTOCTLLEAF(b,m)       \
 285        (((b) & (((s64)1 << ((m) + L2LPERCTL)) - 1)) >> (m))
 286
 287/* convert log2 leaf value to buddy size */
 288#define BUDSIZE(s,m)            (1 << ((s) - (m)))
 289
 290/*
 291 *      external references.
 292 */
 293extern int dbMount(struct inode *ipbmap);
 294
 295extern int dbUnmount(struct inode *ipbmap, int mounterror);
 296
 297extern int dbFree(struct inode *ipbmap, s64 blkno, s64 nblocks);
 298
 299extern int dbUpdatePMap(struct inode *ipbmap,
 300                        int free, s64 blkno, s64 nblocks, struct tblock * tblk);
 301
 302extern int dbNextAG(struct inode *ipbmap);
 303
 304extern int dbAlloc(struct inode *ipbmap, s64 hint, s64 nblocks, s64 * results);
 305
 306extern int dbReAlloc(struct inode *ipbmap,
 307                     s64 blkno, s64 nblocks, s64 addnblocks, s64 * results);
 308
 309extern int dbSync(struct inode *ipbmap);
 310extern int dbAllocBottomUp(struct inode *ip, s64 blkno, s64 nblocks);
 311extern int dbExtendFS(struct inode *ipbmap, s64 blkno, s64 nblocks);
 312extern void dbFinalizeBmap(struct inode *ipbmap);
 313extern s64 dbMapFileSizeToMapSize(struct inode *ipbmap);
 314#endif                          /* _H_JFS_DMAP */
 315
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