fs/jfs/jfs_imap.h

   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_IMAP
  19 #define _H_JFS_IMAP
  20
  21 #include "jfs_txnmgr.h"
  22
  23 /*
  24  *      jfs_imap.h: disk inode manager
  25  */
  26
  27 #define EXTSPERIAG      128     /* number of disk inode extent per iag  */
  28 #define IMAPBLKNO       0       /* lblkno of dinomap within inode map   */
  29 #define SMAPSZ          4       /* number of words per summary map      */
  30 #define EXTSPERSUM      32      /* number of extents per summary map entry */
  31 #define L2EXTSPERSUM    5       /* l2 number of extents per summary map */
  32 #define PGSPERIEXT      4       /* number of 4K pages per dinode extent */
  33 #define MAXIAGS         ((1<<20)-1)     /* maximum number of iags       */
  34 #define MAXAG           128     /* maximum number of allocation groups  */
  35
  36 #define AMAPSIZE      512       /* bytes in the IAG allocation maps */
  37 #define SMAPSIZE      16        /* bytes in the IAG summary maps */
  38
  39 /* convert inode number to iag number */
  40 #define INOTOIAG(ino)   ((ino) >> L2INOSPERIAG)
  41
  42 /* convert iag number to logical block number of the iag page */
  43 #define IAGTOLBLK(iagno,l2nbperpg)      (((iagno) + 1) << (l2nbperpg))
  44
  45 /* get the starting block number of the 4K page of an inode extent
  46  * that contains ino.
  47  */
  48 #define INOPBLK(pxd,ino,l2nbperpg)      (addressPXD((pxd)) +            \
  49         ((((ino) & (INOSPEREXT-1)) >> L2INOSPERPAGE) << (l2nbperpg)))
  50
  51 /*
  52  *      inode allocation map:
  53  *
  54  * inode allocation map consists of
  55  * . the inode map control page and
  56  * . inode allocation group pages (per 4096 inodes)
  57  * which are addressed by standard JFS xtree.
  58  */
  59 /*
  60  *      inode allocation group page (per 4096 inodes of an AG)
  61  */
  62 struct iag {
  63         s64 agstart;            /* 8: starting block of ag              */
  64         s32 iagnum;             /* 4: inode allocation group number     */
  65         s32 inofreefwd;         /* 4: ag inode free list forward        */
  66         s32 inofreeback;        /* 4: ag inode free list back           */
  67         s32 extfreefwd;         /* 4: ag inode extent free list forward */
  68         s32 extfreeback;        /* 4: ag inode extent free list back    */
  69         s32 iagfree;            /* 4: iag free list                     */
  70
  71         /* summary map: 1 bit per inode extent */
  72         s32 inosmap[SMAPSZ];    /* 16: sum map of mapwords w/ free inodes;
  73                                  *      note: this indicates free and backed
  74                                  *      inodes, if the extent is not backed the
  75                                  *      value will be 1.  if the extent is
  76                                  *      backed but all inodes are being used the
  77                                  *      value will be 1.  if the extent is
  78                                  *      backed but at least one of the inodes is
  79                                  *      free the value will be 0.
  80                                  */
  81         s32 extsmap[SMAPSZ];    /* 16: sum map of mapwords w/ free extents */
  82         s32 nfreeinos;          /* 4: number of free inodes             */
  83         s32 nfreeexts;          /* 4: number of free extents            */
  84         /* (72) */
  85         u8 pad[1976];           /* 1976: pad to 2048 bytes */
  86         /* allocation bit map: 1 bit per inode (0 - free, 1 - allocated) */
  87         u32 wmap[EXTSPERIAG];   /* 512: working allocation map  */
  88         u32 pmap[EXTSPERIAG];   /* 512: persistent allocation map */
  89         pxd_t inoext[EXTSPERIAG];       /* 1024: inode extent addresses */
  90 };                              /* (4096) */
  91
  92 /*
  93  *      per AG control information (in inode map control page)
  94  */
  95 struct iagctl {
  96         s32 inofree;            /* 4: free inode list anchor            */
  97         s32 extfree;            /* 4: free extent list anchor           */
  98         s32 numinos;            /* 4: number of backed inodes           */
  99         s32 numfree;            /* 4: number of free inodes             */
 100 };                              /* (16) */
 101
 102 /*
 103  *      per fileset/aggregate inode map control page
 104  */
 105 struct dinomap {
 106         s32 in_freeiag;         /* 4: free iag list anchor     */
 107         s32 in_nextiag;         /* 4: next free iag number     */
 108         s32 in_numinos;         /* 4: num of backed inodes */
 109         s32 in_numfree;         /* 4: num of free backed inodes */
 110         s32 in_nbperiext;       /* 4: num of blocks per inode extent */
 111         s32 in_l2nbperiext;     /* 4: l2 of in_nbperiext */
 112         s32 in_diskblock;       /* 4: for standalone test driver  */
 113         s32 in_maxag;           /* 4: for standalone test driver  */
 114         u8 pad[2016];           /* 2016: pad to 2048 */
 115         struct iagctl in_agctl[MAXAG];  /* 2048: AG control information */
 116 };                              /* (4096) */
 117
 118
 119 /*
 120  *      In-core inode map control page
 121  */
 122 struct inomap {
 123         struct dinomap im_imap;         /* 4096: inode allocation control */
 124         struct inode *im_ipimap;        /* 4: ptr to inode for imap   */
 125         struct semaphore im_freelock;   /* 4: iag free list lock      */
 126         struct semaphore im_aglock[MAXAG];      /* 512: per AG locks          */
 127         u32 *im_DBGdimap;
 128         atomic_t im_numinos;    /* num of backed inodes */
 129         atomic_t im_numfree;    /* num of free backed inodes */
 130 };
 131
 132 #define im_freeiag      im_imap.in_freeiag
 133 #define im_nextiag      im_imap.in_nextiag
 134 #define im_agctl        im_imap.in_agctl
 135 #define im_nbperiext    im_imap.in_nbperiext
 136 #define im_l2nbperiext  im_imap.in_l2nbperiext
 137
 138 /* for standalone testdriver
 139  */
 140 #define im_diskblock    im_imap.in_diskblock
 141 #define im_maxag        im_imap.in_maxag
 142
 143 extern int diFree(struct inode *);
 144 extern int diAlloc(struct inode *, boolean_t, struct inode *);
 145 extern int diSync(struct inode *);
 146 /* external references */
 147 extern int diUpdatePMap(struct inode *ipimap, unsigned long inum,
 148                         boolean_t is_free, struct tblock * tblk);
 149 extern int diExtendFS(struct inode *ipimap, struct inode *ipbmap);
 150 extern int diMount(struct inode *);
 151 extern int diUnmount(struct inode *, int);
 152 extern int diRead(struct inode *);
 153 extern struct inode *diReadSpecial(struct super_block *, ino_t, int);
 154 extern void diWriteSpecial(struct inode *, int);
 155 extern void diFreeSpecial(struct inode *);
 156 extern int diWrite(tid_t tid, struct inode *);
 157 #endif                          /* _H_JFS_IMAP */