xfs_bmap_btree.h

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/*
 * Copyright (c) 2000,2002-2005 Silicon Graphics, Inc.
 * All Rights Reserved.
 *
 * 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.
 *
 * This program is distributed in the hope that it would 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 the Free Software Foundation,
 * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */
#ifndef __XFS_BMAP_BTREE_H__
#define __XFS_BMAP_BTREE_H__

#define XFS_BMAP_MAGIC  0x424d4150  /* 'BMAP' */

struct xfs_btree_cur;
struct xfs_btree_block;
struct xfs_mount;
struct xfs_inode;
struct xfs_trans;

/*
 * Bmap root header, on-disk form only.
 */
typedef struct xfs_bmdr_block {
    __be16      bb_level;   /* 0 is a leaf */
    __be16      bb_numrecs; /* current # of data records */
} xfs_bmdr_block_t;

/*
 * Bmap btree record and extent descriptor.
 *  l0:63 is an extent flag (value 1 indicates non-normal).
 *  l0:9-62 are startoff.
 *  l0:0-8 and l1:21-63 are startblock.
 *  l1:0-20 are blockcount.
 */
#define BMBT_EXNTFLAG_BITLEN    1
#define BMBT_STARTOFF_BITLEN    54
#define BMBT_STARTBLOCK_BITLEN  52
#define BMBT_BLOCKCOUNT_BITLEN  21

typedef struct xfs_bmbt_rec {
    __be64          l0, l1;
} xfs_bmbt_rec_t;

typedef __uint64_t  xfs_bmbt_rec_base_t;    /* use this for casts */
typedef xfs_bmbt_rec_t xfs_bmdr_rec_t;

typedef struct xfs_bmbt_rec_host {
    __uint64_t      l0, l1;
} xfs_bmbt_rec_host_t;

/*
 * Values and macros for delayed-allocation startblock fields.
 */
#define STARTBLOCKVALBITS   17
#define STARTBLOCKMASKBITS  (15 + XFS_BIG_BLKNOS * 20)
#define DSTARTBLOCKMASKBITS (15 + 20)
#define STARTBLOCKMASK      \
    (((((xfs_fsblock_t)1) << STARTBLOCKMASKBITS) - 1) << STARTBLOCKVALBITS)
#define DSTARTBLOCKMASK     \
    (((((xfs_dfsbno_t)1) << DSTARTBLOCKMASKBITS) - 1) << STARTBLOCKVALBITS)

static inline int isnullstartblock(xfs_fsblock_t x)
{
    return ((x) & STARTBLOCKMASK) == STARTBLOCKMASK;
}

static inline int isnulldstartblock(xfs_dfsbno_t x)
{
    return ((x) & DSTARTBLOCKMASK) == DSTARTBLOCKMASK;
}

static inline xfs_fsblock_t nullstartblock(int k)
{
    ASSERT(k < (1 << STARTBLOCKVALBITS));
    return STARTBLOCKMASK | (k);
}

static inline xfs_filblks_t startblockval(xfs_fsblock_t x)
{
    return (xfs_filblks_t)((x) & ~STARTBLOCKMASK);
}

/*
 * Possible extent formats.
 */
typedef enum {
    XFS_EXTFMT_NOSTATE = 0,
    XFS_EXTFMT_HASSTATE
} xfs_exntfmt_t;

/*
 * Possible extent states.
 */
typedef enum {
    XFS_EXT_NORM, XFS_EXT_UNWRITTEN,
    XFS_EXT_DMAPI_OFFLINE, XFS_EXT_INVALID
} xfs_exntst_t;

/*
 * Extent state and extent format macros.
 */
#define XFS_EXTFMT_INODE(x) \
    (xfs_sb_version_hasextflgbit(&((x)->i_mount->m_sb)) ? \
        XFS_EXTFMT_HASSTATE : XFS_EXTFMT_NOSTATE)
#define ISUNWRITTEN(x)  ((x)->br_state == XFS_EXT_UNWRITTEN)

/*
 * Incore version of above.
 */
typedef struct xfs_bmbt_irec
{
    xfs_fileoff_t   br_startoff;    /* starting file offset */
    xfs_fsblock_t   br_startblock;  /* starting block number */
    xfs_filblks_t   br_blockcount;  /* number of blocks */
    xfs_exntst_t    br_state;   /* extent state */
} xfs_bmbt_irec_t;

/*
 * Key structure for non-leaf levels of the tree.
 */
typedef struct xfs_bmbt_key {
    __be64      br_startoff;    /* starting file offset */
} xfs_bmbt_key_t, xfs_bmdr_key_t;

/* btree pointer type */
typedef __be64 xfs_bmbt_ptr_t, xfs_bmdr_ptr_t;

/*
 * Btree block header size depends on a superblock flag.
 *
 * (not quite yet, but soon)
 */
#define XFS_BMBT_BLOCK_LEN(mp)  XFS_BTREE_LBLOCK_LEN

#define XFS_BMBT_REC_ADDR(mp, block, index) \
    ((xfs_bmbt_rec_t *) \
        ((char *)(block) + \
         XFS_BMBT_BLOCK_LEN(mp) + \
         ((index) - 1) * sizeof(xfs_bmbt_rec_t)))

#define XFS_BMBT_KEY_ADDR(mp, block, index) \
    ((xfs_bmbt_key_t *) \
        ((char *)(block) + \
         XFS_BMBT_BLOCK_LEN(mp) + \
         ((index) - 1) * sizeof(xfs_bmbt_key_t)))

#define XFS_BMBT_PTR_ADDR(mp, block, index, maxrecs) \
    ((xfs_bmbt_ptr_t *) \
        ((char *)(block) + \
         XFS_BMBT_BLOCK_LEN(mp) + \
         (maxrecs) * sizeof(xfs_bmbt_key_t) + \
         ((index) - 1) * sizeof(xfs_bmbt_ptr_t)))

#define XFS_BMDR_REC_ADDR(block, index) \
    ((xfs_bmdr_rec_t *) \
        ((char *)(block) + \
         sizeof(struct xfs_bmdr_block) + \
             ((index) - 1) * sizeof(xfs_bmdr_rec_t)))

#define XFS_BMDR_KEY_ADDR(block, index) \
    ((xfs_bmdr_key_t *) \
        ((char *)(block) + \
         sizeof(struct xfs_bmdr_block) + \
         ((index) - 1) * sizeof(xfs_bmdr_key_t)))

#define XFS_BMDR_PTR_ADDR(block, index, maxrecs) \
    ((xfs_bmdr_ptr_t *) \
        ((char *)(block) + \
         sizeof(struct xfs_bmdr_block) + \
         (maxrecs) * sizeof(xfs_bmdr_key_t) + \
         ((index) - 1) * sizeof(xfs_bmdr_ptr_t)))

/*
 * These are to be used when we know the size of the block and
 * we don't have a cursor.
 */
#define XFS_BMAP_BROOT_PTR_ADDR(mp, bb, i, sz) \
    XFS_BMBT_PTR_ADDR(mp, bb, i, xfs_bmbt_maxrecs(mp, sz, 0))

#define XFS_BMAP_BROOT_SPACE_CALC(nrecs) \
    (int)(XFS_BTREE_LBLOCK_LEN + \
           ((nrecs) * (sizeof(xfs_bmbt_key_t) + sizeof(xfs_bmbt_ptr_t))))

#define XFS_BMAP_BROOT_SPACE(bb) \
    (XFS_BMAP_BROOT_SPACE_CALC(be16_to_cpu((bb)->bb_numrecs)))
#define XFS_BMDR_SPACE_CALC(nrecs) \
    (int)(sizeof(xfs_bmdr_block_t) + \
           ((nrecs) * (sizeof(xfs_bmbt_key_t) + sizeof(xfs_bmbt_ptr_t))))

/*
 * Maximum number of bmap btree levels.
 */
#define XFS_BM_MAXLEVELS(mp,w)      ((mp)->m_bm_maxlevels[(w)])

/*
 * Prototypes for xfs_bmap.c to call.
 */
extern void xfs_bmdr_to_bmbt(struct xfs_mount *, xfs_bmdr_block_t *, int,
            struct xfs_btree_block *, int);
extern void xfs_bmbt_get_all(xfs_bmbt_rec_host_t *r, xfs_bmbt_irec_t *s);
extern xfs_filblks_t xfs_bmbt_get_blockcount(xfs_bmbt_rec_host_t *r);
extern xfs_fsblock_t xfs_bmbt_get_startblock(xfs_bmbt_rec_host_t *r);
extern xfs_fileoff_t xfs_bmbt_get_startoff(xfs_bmbt_rec_host_t *r);
extern xfs_exntst_t xfs_bmbt_get_state(xfs_bmbt_rec_host_t *r);

extern xfs_filblks_t xfs_bmbt_disk_get_blockcount(xfs_bmbt_rec_t *r);
extern xfs_fileoff_t xfs_bmbt_disk_get_startoff(xfs_bmbt_rec_t *r);

extern void xfs_bmbt_set_all(xfs_bmbt_rec_host_t *r, xfs_bmbt_irec_t *s);
extern void xfs_bmbt_set_allf(xfs_bmbt_rec_host_t *r, xfs_fileoff_t o,
            xfs_fsblock_t b, xfs_filblks_t c, xfs_exntst_t v);
extern void xfs_bmbt_set_blockcount(xfs_bmbt_rec_host_t *r, xfs_filblks_t v);
extern void xfs_bmbt_set_startblock(xfs_bmbt_rec_host_t *r, xfs_fsblock_t v);
extern void xfs_bmbt_set_startoff(xfs_bmbt_rec_host_t *r, xfs_fileoff_t v);
extern void xfs_bmbt_set_state(xfs_bmbt_rec_host_t *r, xfs_exntst_t v);

extern void xfs_bmbt_disk_set_allf(xfs_bmbt_rec_t *r, xfs_fileoff_t o,
            xfs_fsblock_t b, xfs_filblks_t c, xfs_exntst_t v);

extern void xfs_bmbt_to_bmdr(struct xfs_mount *, struct xfs_btree_block *, int,
            xfs_bmdr_block_t *, int);

extern int xfs_bmbt_get_maxrecs(struct xfs_btree_cur *, int level);
extern int xfs_bmdr_maxrecs(struct xfs_mount *, int blocklen, int leaf);
extern int xfs_bmbt_maxrecs(struct xfs_mount *, int blocklen, int leaf);

extern struct xfs_btree_cur *xfs_bmbt_init_cursor(struct xfs_mount *,
        struct xfs_trans *, struct xfs_inode *, int);


#endif  /* __XFS_BMAP_BTREE_H__ */