jfs_xtree.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_XTREE
#define _H_JFS_XTREE

/*
 *  jfs_xtree.h: extent allocation descriptor B+-tree manager
 */

#include "jfs_btree.h"


/*
 *  extent allocation descriptor (xad)
 */
typedef struct xad {
    unsigned flag:8;    /* 1: flag */
    unsigned rsvrd:16;  /* 2: reserved */
    unsigned off1:8;    /* 1: offset in unit of fsblksize */
    __le32 off2;        /* 4: offset in unit of fsblksize */
    unsigned len:24;    /* 3: length in unit of fsblksize */
    unsigned addr1:8;   /* 1: address in unit of fsblksize */
    __le32 addr2;       /* 4: address in unit of fsblksize */
} xad_t;            /* (16) */

#define MAXXLEN     ((1 << 24) - 1)

#define XTSLOTSIZE  16
#define L2XTSLOTSIZE    4

/* xad_t field construction */
#define XADoffset(xad, offset64)\
{\
    (xad)->off1 = ((u64)offset64) >> 32;\
    (xad)->off2 = __cpu_to_le32((offset64) & 0xffffffff);\
}
#define XADaddress(xad, address64)\
{\
    (xad)->addr1 = ((u64)address64) >> 32;\
    (xad)->addr2 = __cpu_to_le32((address64) & 0xffffffff);\
}
#define XADlength(xad, length32)    (xad)->len = __cpu_to_le24(length32)

/* xad_t field extraction */
#define offsetXAD(xad)\
    ( ((s64)((xad)->off1)) << 32 | __le32_to_cpu((xad)->off2))
#define addressXAD(xad)\
    ( ((s64)((xad)->addr1)) << 32 | __le32_to_cpu((xad)->addr2))
#define lengthXAD(xad)  __le24_to_cpu((xad)->len)

/* xad list */
struct xadlist {
    s16 maxnxad;
    s16 nxad;
    xad_t *xad;
};

/* xad_t flags */
#define XAD_NEW     0x01    /* new */
#define XAD_EXTENDED    0x02    /* extended */
#define XAD_COMPRESSED  0x04    /* compressed with recorded length */
#define XAD_NOTRECORDED 0x08    /* allocated but not recorded */
#define XAD_COW     0x10    /* copy-on-write */


/* possible values for maxentry */
#define XTROOTINITSLOT_DIR 6
#define XTROOTINITSLOT  10
#define XTROOTMAXSLOT   18
#define XTPAGEMAXSLOT   256
#define XTENTRYSTART    2

/*
 *  xtree page:
 */
typedef union {
    struct xtheader {
        __le64 next;    /* 8: */
        __le64 prev;    /* 8: */

        u8 flag;    /* 1: */
        u8 rsrvd1;  /* 1: */
        __le16 nextindex;   /* 2: next index = number of entries */
        __le16 maxentry;    /* 2: max number of entries */
        __le16 rsrvd2;  /* 2: */

        pxd_t self; /* 8: self */
    } header;       /* (32) */

    xad_t xad[XTROOTMAXSLOT];   /* 16 * maxentry: xad array */
} xtpage_t;

/*
 *  external declaration
 */
extern int xtLookup(struct inode *ip, s64 lstart, s64 llen,
            int *pflag, s64 * paddr, int *plen, int flag);
extern void xtInitRoot(tid_t tid, struct inode *ip);
extern int xtInsert(tid_t tid, struct inode *ip,
            int xflag, s64 xoff, int xlen, s64 * xaddrp, int flag);
extern int xtExtend(tid_t tid, struct inode *ip, s64 xoff, int xlen,
            int flag);
#ifdef _NOTYET
extern int xtTailgate(tid_t tid, struct inode *ip,
              s64 xoff, int xlen, s64 xaddr, int flag);
#endif
extern int xtUpdate(tid_t tid, struct inode *ip, struct xad *nxad);
extern int xtDelete(tid_t tid, struct inode *ip, s64 xoff, int xlen,
            int flag);
extern s64 xtTruncate(tid_t tid, struct inode *ip, s64 newsize, int type);
extern s64 xtTruncate_pmap(tid_t tid, struct inode *ip, s64 committed_size);
extern int xtRelocate(tid_t tid, struct inode *ip,
              xad_t * oxad, s64 nxaddr, int xtype);
extern int xtAppend(tid_t tid,
            struct inode *ip, int xflag, s64 xoff, int maxblocks,
            int *xlenp, s64 * xaddrp, int flag);
#endif              /* !_H_JFS_XTREE */