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root/fs/jfs/jfs_imap.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_IMAP
#define _H_JFS_IMAP

#include "jfs_txnmgr.h"

/*
 *      jfs_imap.h: disk inode manager
 */

#define EXTSPERIAG      128     /* number of disk inode extent per iag  */
#define IMAPBLKNO       0       /* lblkno of dinomap within inode map   */
#define SMAPSZ          4       /* number of words per summary map      */
#define EXTSPERSUM      32      /* number of extents per summary map entry */
#define L2EXTSPERSUM    5       /* l2 number of extents per summary map */
#define PGSPERIEXT      4       /* number of 4K pages per dinode extent */
#define MAXIAGS         ((1<<20)-1)     /* maximum number of iags       */
#define MAXAG           128     /* maximum number of allocation groups  */

#define AMAPSIZE        512     /* bytes in the IAG allocation maps */
#define SMAPSIZE        16      /* bytes in the IAG summary maps */

/* convert inode number to iag number */
#define INOTOIAG(ino)   ((ino) >> L2INOSPERIAG)

/* convert iag number to logical block number of the iag page */
#define IAGTOLBLK(iagno,l2nbperpg)      (((iagno) + 1) << (l2nbperpg))

/* get the starting block number of the 4K page of an inode extent
 * that contains ino.
 */
#define INOPBLK(pxd,ino,l2nbperpg)      (addressPXD((pxd)) +            \
        ((((ino) & (INOSPEREXT-1)) >> L2INOSPERPAGE) << (l2nbperpg)))

/*
 *      inode allocation map:
 *
 * inode allocation map consists of
 * . the inode map control page and
 * . inode allocation group pages (per 4096 inodes)
 * which are addressed by standard JFS xtree.
 */
/*
 *      inode allocation group page (per 4096 inodes of an AG)
 */
struct iag {
        __le64 agstart;         /* 8: starting block of ag              */
        __le32 iagnum;          /* 4: inode allocation group number     */
        __le32 inofreefwd;      /* 4: ag inode free list forward        */
        __le32 inofreeback;     /* 4: ag inode free list back           */
        __le32 extfreefwd;      /* 4: ag inode extent free list forward */
        __le32 extfreeback;     /* 4: ag inode extent free list back    */
        __le32 iagfree;         /* 4: iag free list                     */

        /* summary map: 1 bit per inode extent */
        __le32 inosmap[SMAPSZ]; /* 16: sum map of mapwords w/ free inodes;
                                 *      note: this indicates free and backed
                                 *      inodes, if the extent is not backed the
                                 *      value will be 1.  if the extent is
                                 *      backed but all inodes are being used the
                                 *      value will be 1.  if the extent is
                                 *      backed but at least one of the inodes is
                                 *      free the value will be 0.
                                 */
        __le32 extsmap[SMAPSZ]; /* 16: sum map of mapwords w/ free extents */
        __le32 nfreeinos;       /* 4: number of free inodes             */
        __le32 nfreeexts;       /* 4: number of free extents            */
        /* (72) */
        u8 pad[1976];           /* 1976: pad to 2048 bytes */
        /* allocation bit map: 1 bit per inode (0 - free, 1 - allocated) */
        __le32 wmap[EXTSPERIAG];        /* 512: working allocation map */
        __le32 pmap[EXTSPERIAG];        /* 512: persistent allocation map */
        pxd_t inoext[EXTSPERIAG];       /* 1024: inode extent addresses */
};                              /* (4096) */

/*
 *      per AG control information (in inode map control page)
 */
struct iagctl_disk {
        __le32 inofree;         /* 4: free inode list anchor            */
        __le32 extfree;         /* 4: free extent list anchor           */
        __le32 numinos;         /* 4: number of backed inodes           */
        __le32 numfree;         /* 4: number of free inodes             */
};                              /* (16) */

struct iagctl {
        int inofree;            /* free inode list anchor               */
        int extfree;            /* free extent list anchor              */
        int numinos;            /* number of backed inodes              */
        int numfree;            /* number of free inodes                */
};

/*
 *      per fileset/aggregate inode map control page
 */
struct dinomap_disk {
        __le32 in_freeiag;      /* 4: free iag list anchor      */
        __le32 in_nextiag;      /* 4: next free iag number      */
        __le32 in_numinos;      /* 4: num of backed inodes      */
        __le32 in_numfree;      /* 4: num of free backed inodes */
        __le32 in_nbperiext;    /* 4: num of blocks per inode extent */
        __le32 in_l2nbperiext;  /* 4: l2 of in_nbperiext        */
        __le32 in_diskblock;    /* 4: for standalone test driver */
        __le32 in_maxag;        /* 4: for standalone test driver */
        u8 pad[2016];           /* 2016: pad to 2048            */
        struct iagctl_disk in_agctl[MAXAG]; /* 2048: AG control information */
};                              /* (4096) */

struct dinomap {
        int in_freeiag;         /* free iag list anchor         */
        int in_nextiag;         /* next free iag number         */
        int in_numinos;         /* num of backed inodes         */
        int in_numfree;         /* num of free backed inodes    */
        int in_nbperiext;       /* num of blocks per inode extent */
        int in_l2nbperiext;     /* l2 of in_nbperiext           */
        int in_diskblock;       /* for standalone test driver   */
        int in_maxag;           /* for standalone test driver   */
        struct iagctl in_agctl[MAXAG];  /* AG control information */
};

/*
 *      In-core inode map control page
 */
struct inomap {
        struct dinomap im_imap;         /* 4096: inode allocation control */
        struct inode *im_ipimap;        /* 4: ptr to inode for imap     */
        struct mutex im_freelock;       /* 4: iag free list lock        */
        struct mutex im_aglock[MAXAG];  /* 512: per AG locks            */
        u32 *im_DBGdimap;
        atomic_t im_numinos;    /* num of backed inodes */
        atomic_t im_numfree;    /* num of free backed inodes */
};

#define im_freeiag      im_imap.in_freeiag
#define im_nextiag      im_imap.in_nextiag
#define im_agctl        im_imap.in_agctl
#define im_nbperiext    im_imap.in_nbperiext
#define im_l2nbperiext  im_imap.in_l2nbperiext

/* for standalone testdriver
 */
#define im_diskblock    im_imap.in_diskblock
#define im_maxag        im_imap.in_maxag

extern int diFree(struct inode *);
extern int diAlloc(struct inode *, bool, struct inode *);
extern int diSync(struct inode *);
/* external references */
extern int diUpdatePMap(struct inode *ipimap, unsigned long inum,
                        bool is_free, struct tblock * tblk);
extern int diExtendFS(struct inode *ipimap, struct inode *ipbmap);
extern int diMount(struct inode *);
extern int diUnmount(struct inode *, int);
extern int diRead(struct inode *);
extern struct inode *diReadSpecial(struct super_block *, ino_t, int);
extern void diWriteSpecial(struct inode *, int);
extern void diFreeSpecial(struct inode *);
extern int diWrite(tid_t tid, struct inode *);
#endif                          /* _H_JFS_IMAP */

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