LXR linux/fs/xfs/xfs_bmap

   1/*
   2 * Copyright (c) 2000,2002-2005 Silicon Graphics, Inc.
   3 * All Rights Reserved.
   4 *
   5 * This program is free software; you can redistribute it and/or
   6 * modify it under the terms of the GNU General Public License as
   7 * published by the Free Software Foundation.
   8 *
   9 * This program is distributed in the hope that it would be useful,
  10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 * 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 the Free Software Foundation,
  16 * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  17 */
  18#ifndef __XFS_BMAP_BTREE_H__
  19#define __XFS_BMAP_BTREE_H__
  20
  21#define XFS_BMAP_MAGIC  0x424d4150      /* 'BMAP' */
  22
  23struct xfs_btree_cur;
  24struct xfs_btree_block;
  25struct xfs_mount;
  26struct xfs_inode;
  27struct xfs_trans;
  28
  29/*
  30 * Bmap root header, on-disk form only.
  31 */
  32typedef struct xfs_bmdr_block {
  33        __be16          bb_level;       /* 0 is a leaf */
  34        __be16          bb_numrecs;     /* current # of data records */
  35} xfs_bmdr_block_t;
  36
  37/*
  38 * Bmap btree record and extent descriptor.
  39 *  l0:63 is an extent flag (value 1 indicates non-normal).
  40 *  l0:9-62 are startoff.
  41 *  l0:0-8 and l1:21-63 are startblock.
  42 *  l1:0-20 are blockcount.
  43 */
  44#define BMBT_EXNTFLAG_BITLEN    1
  45#define BMBT_STARTOFF_BITLEN    54
  46#define BMBT_STARTBLOCK_BITLEN  52
  47#define BMBT_BLOCKCOUNT_BITLEN  21
  48
  49typedef struct xfs_bmbt_rec {
  50        __be64                  l0, l1;
  51} xfs_bmbt_rec_t;
  52
  53typedef __uint64_t      xfs_bmbt_rec_base_t;    /* use this for casts */
  54typedef xfs_bmbt_rec_t xfs_bmdr_rec_t;
  55
  56typedef struct xfs_bmbt_rec_host {
  57        __uint64_t              l0, l1;
  58} xfs_bmbt_rec_host_t;
  59
  60/*
  61 * Values and macros for delayed-allocation startblock fields.
  62 */
  63#define STARTBLOCKVALBITS       17
  64#define STARTBLOCKMASKBITS      (15 + XFS_BIG_BLKNOS * 20)
  65#define DSTARTBLOCKMASKBITS     (15 + 20)
  66#define STARTBLOCKMASK          \
  67        (((((xfs_fsblock_t)1) << STARTBLOCKMASKBITS) - 1) << STARTBLOCKVALBITS)
  68#define DSTARTBLOCKMASK         \
  69        (((((xfs_dfsbno_t)1) << DSTARTBLOCKMASKBITS) - 1) << STARTBLOCKVALBITS)
  70
  71static inline int isnullstartblock(xfs_fsblock_t x)
  72{
  73        return ((x) & STARTBLOCKMASK) == STARTBLOCKMASK;
  74}
  75
  76static inline int isnulldstartblock(xfs_dfsbno_t x)
  77{
  78        return ((x) & DSTARTBLOCKMASK) == DSTARTBLOCKMASK;
  79}
  80
  81static inline xfs_fsblock_t nullstartblock(int k)
  82{
  83        ASSERT(k < (1 << STARTBLOCKVALBITS));
  84        return STARTBLOCKMASK | (k);
  85}
  86
  87static inline xfs_filblks_t startblockval(xfs_fsblock_t x)
  88{
  89        return (xfs_filblks_t)((x) & ~STARTBLOCKMASK);
  90}
  91
  92/*
  93 * Possible extent formats.
  94 */
  95typedef enum {
  96        XFS_EXTFMT_NOSTATE = 0,
  97        XFS_EXTFMT_HASSTATE
  98} xfs_exntfmt_t;
  99
 100/*
 101 * Possible extent states.
 102 */
 103typedef enum {
 104        XFS_EXT_NORM, XFS_EXT_UNWRITTEN,
 105        XFS_EXT_DMAPI_OFFLINE, XFS_EXT_INVALID
 106} xfs_exntst_t;
 107
 108/*
 109 * Extent state and extent format macros.
 110 */
 111#define XFS_EXTFMT_INODE(x)     \
 112        (xfs_sb_version_hasextflgbit(&((x)->i_mount->m_sb)) ? \
 113                XFS_EXTFMT_HASSTATE : XFS_EXTFMT_NOSTATE)
 114#define ISUNWRITTEN(x)  ((x)->br_state == XFS_EXT_UNWRITTEN)
 115
 116/*
 117 * Incore version of above.
 118 */
 119typedef struct xfs_bmbt_irec
 120{
 121        xfs_fileoff_t   br_startoff;    /* starting file offset */
 122        xfs_fsblock_t   br_startblock;  /* starting block number */
 123        xfs_filblks_t   br_blockcount;  /* number of blocks */
 124        xfs_exntst_t    br_state;       /* extent state */
 125} xfs_bmbt_irec_t;
 126
 127/*
 128 * Key structure for non-leaf levels of the tree.
 129 */
 130typedef struct xfs_bmbt_key {
 131        __be64          br_startoff;    /* starting file offset */
 132} xfs_bmbt_key_t, xfs_bmdr_key_t;
 133
 134/* btree pointer type */
 135typedef __be64 xfs_bmbt_ptr_t, xfs_bmdr_ptr_t;
 136
 137/*
 138 * Btree block header size depends on a superblock flag.
 139 *
 140 * (not quite yet, but soon)
 141 */
 142#define XFS_BMBT_BLOCK_LEN(mp)  XFS_BTREE_LBLOCK_LEN
 143
 144#define XFS_BMBT_REC_ADDR(mp, block, index) \
 145        ((xfs_bmbt_rec_t *) \
 146                ((char *)(block) + \
 147                 XFS_BMBT_BLOCK_LEN(mp) + \
 148                 ((index) - 1) * sizeof(xfs_bmbt_rec_t)))
 149
 150#define XFS_BMBT_KEY_ADDR(mp, block, index) \
 151        ((xfs_bmbt_key_t *) \
 152                ((char *)(block) + \
 153                 XFS_BMBT_BLOCK_LEN(mp) + \
 154                 ((index) - 1) * sizeof(xfs_bmbt_key_t)))
 155
 156#define XFS_BMBT_PTR_ADDR(mp, block, index, maxrecs) \
 157        ((xfs_bmbt_ptr_t *) \
 158                ((char *)(block) + \
 159                 XFS_BMBT_BLOCK_LEN(mp) + \
 160                 (maxrecs) * sizeof(xfs_bmbt_key_t) + \
 161                 ((index) - 1) * sizeof(xfs_bmbt_ptr_t)))
 162
 163#define XFS_BMDR_REC_ADDR(block, index) \
 164        ((xfs_bmdr_rec_t *) \
 165                ((char *)(block) + \
 166                 sizeof(struct xfs_bmdr_block) + \
 167                 ((index) - 1) * sizeof(xfs_bmdr_rec_t)))
 168
 169#define XFS_BMDR_KEY_ADDR(block, index) \
 170        ((xfs_bmdr_key_t *) \
 171                ((char *)(block) + \
 172                 sizeof(struct xfs_bmdr_block) + \
 173                 ((index) - 1) * sizeof(xfs_bmdr_key_t)))
 174
 175#define XFS_BMDR_PTR_ADDR(block, index, maxrecs) \
 176        ((xfs_bmdr_ptr_t *) \
 177                ((char *)(block) + \
 178                 sizeof(struct xfs_bmdr_block) + \
 179                 (maxrecs) * sizeof(xfs_bmdr_key_t) + \
 180                 ((index) - 1) * sizeof(xfs_bmdr_ptr_t)))
 181
 182/*
 183 * These are to be used when we know the size of the block and
 184 * we don't have a cursor.
 185 */
 186#define XFS_BMAP_BROOT_PTR_ADDR(mp, bb, i, sz) \
 187        XFS_BMBT_PTR_ADDR(mp, bb, i, xfs_bmbt_maxrecs(mp, sz, 0))
 188
 189#define XFS_BMAP_BROOT_SPACE_CALC(nrecs) \
 190        (int)(XFS_BTREE_LBLOCK_LEN + \
 191               ((nrecs) * (sizeof(xfs_bmbt_key_t) + sizeof(xfs_bmbt_ptr_t))))
 192
 193#define XFS_BMAP_BROOT_SPACE(bb) \
 194        (XFS_BMAP_BROOT_SPACE_CALC(be16_to_cpu((bb)->bb_numrecs)))
 195#define XFS_BMDR_SPACE_CALC(nrecs) \
 196        (int)(sizeof(xfs_bmdr_block_t) + \
 197               ((nrecs) * (sizeof(xfs_bmbt_key_t) + sizeof(xfs_bmbt_ptr_t))))
 198
 199/*
 200 * Maximum number of bmap btree levels.
 201 */
 202#define XFS_BM_MAXLEVELS(mp,w)          ((mp)->m_bm_maxlevels[(w)])
 203
 204/*
 205 * Prototypes for xfs_bmap.c to call.
 206 */
 207extern void xfs_bmdr_to_bmbt(struct xfs_mount *, xfs_bmdr_block_t *, int,
 208                        struct xfs_btree_block *, int);
 209extern void xfs_bmbt_get_all(xfs_bmbt_rec_host_t *r, xfs_bmbt_irec_t *s);
 210extern xfs_filblks_t xfs_bmbt_get_blockcount(xfs_bmbt_rec_host_t *r);
 211extern xfs_fsblock_t xfs_bmbt_get_startblock(xfs_bmbt_rec_host_t *r);
 212extern xfs_fileoff_t xfs_bmbt_get_startoff(xfs_bmbt_rec_host_t *r);
 213extern xfs_exntst_t xfs_bmbt_get_state(xfs_bmbt_rec_host_t *r);
 214
 215extern xfs_filblks_t xfs_bmbt_disk_get_blockcount(xfs_bmbt_rec_t *r);
 216extern xfs_fileoff_t xfs_bmbt_disk_get_startoff(xfs_bmbt_rec_t *r);
 217
 218extern void xfs_bmbt_set_all(xfs_bmbt_rec_host_t *r, xfs_bmbt_irec_t *s);
 219extern void xfs_bmbt_set_allf(xfs_bmbt_rec_host_t *r, xfs_fileoff_t o,
 220                        xfs_fsblock_t b, xfs_filblks_t c, xfs_exntst_t v);
 221extern void xfs_bmbt_set_blockcount(xfs_bmbt_rec_host_t *r, xfs_filblks_t v);
 222extern void xfs_bmbt_set_startblock(xfs_bmbt_rec_host_t *r, xfs_fsblock_t v);
 223extern void xfs_bmbt_set_startoff(xfs_bmbt_rec_host_t *r, xfs_fileoff_t v);
 224extern void xfs_bmbt_set_state(xfs_bmbt_rec_host_t *r, xfs_exntst_t v);
 225
 226extern void xfs_bmbt_disk_set_allf(xfs_bmbt_rec_t *r, xfs_fileoff_t o,
 227                        xfs_fsblock_t b, xfs_filblks_t c, xfs_exntst_t v);
 228
 229extern void xfs_bmbt_to_bmdr(struct xfs_mount *, struct xfs_btree_block *, int,
 230                        xfs_bmdr_block_t *, int);
 231
 232extern int xfs_bmbt_get_maxrecs(struct xfs_btree_cur *, int level);
 233extern int xfs_bmdr_maxrecs(struct xfs_mount *, int blocklen, int leaf);
 234extern int xfs_bmbt_maxrecs(struct xfs_mount *, int blocklen, int leaf);
 235
 236extern struct xfs_btree_cur *xfs_bmbt_init_cursor(struct xfs_mount *,
 237                struct xfs_trans *, struct xfs_inode *, int);
 238
 239
 240#endif  /* __XFS_BMAP_BTREE_H__ */
 241