release/src-rt-6.x.4708/linux/linux-2.6.36/fs/xfs/xfs_bmap_btree.h

   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
  23 struct xfs_btree_cur;
  24 struct xfs_btree_block;
  25 struct xfs_mount;
  26 struct xfs_inode;
  27 struct xfs_trans;
  28
  29 /*
  30  * Bmap root header, on-disk form only.
  31  */
  32 typedef 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
  49 typedef struct xfs_bmbt_rec {
  50         __be64                  l0, l1;
  51 } xfs_bmbt_rec_t;
  52
  53 typedef __uint64_t      xfs_bmbt_rec_base_t;    /* use this for casts */
  54 typedef xfs_bmbt_rec_t xfs_bmdr_rec_t;
  55
  56 typedef 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
  71 static inline int isnullstartblock(xfs_fsblock_t x)
  72 {
  73         return ((x) & STARTBLOCKMASK) == STARTBLOCKMASK;
  74 }
  75
  76 static inline int isnulldstartblock(xfs_dfsbno_t x)
  77 {
  78         return ((x) & DSTARTBLOCKMASK) == DSTARTBLOCKMASK;
  79 }
  80
  81 static inline xfs_fsblock_t nullstartblock(int k)
  82 {
  83         ASSERT(k < (1 << STARTBLOCKVALBITS));
  84         return STARTBLOCKMASK | (k);
  85 }
  86
  87 static 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  */
  95 typedef enum {
  96         XFS_EXTFMT_NOSTATE = 0,
  97         XFS_EXTFMT_HASSTATE
  98 } xfs_exntfmt_t;
  99
 100 /*
 101  * Possible extent states.
 102  */
 103 typedef 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  */
 119 typedef 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  */
 130 typedef 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 */
 135 typedef __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  */
 207 extern void xfs_bmdr_to_bmbt(struct xfs_mount *, xfs_bmdr_block_t *, int,
 208                         struct xfs_btree_block *, int);
 209 extern void xfs_bmbt_get_all(xfs_bmbt_rec_host_t *r, xfs_bmbt_irec_t *s);
 210 extern xfs_filblks_t xfs_bmbt_get_blockcount(xfs_bmbt_rec_host_t *r);
 211 extern xfs_fsblock_t xfs_bmbt_get_startblock(xfs_bmbt_rec_host_t *r);
 212 extern xfs_fileoff_t xfs_bmbt_get_startoff(xfs_bmbt_rec_host_t *r);
 213 extern xfs_exntst_t xfs_bmbt_get_state(xfs_bmbt_rec_host_t *r);
 214
 215 extern xfs_filblks_t xfs_bmbt_disk_get_blockcount(xfs_bmbt_rec_t *r);
 216 extern xfs_fileoff_t xfs_bmbt_disk_get_startoff(xfs_bmbt_rec_t *r);
 217
 218 extern void xfs_bmbt_set_all(xfs_bmbt_rec_host_t *r, xfs_bmbt_irec_t *s);
 219 extern 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);
 221 extern void xfs_bmbt_set_blockcount(xfs_bmbt_rec_host_t *r, xfs_filblks_t v);
 222 extern void xfs_bmbt_set_startblock(xfs_bmbt_rec_host_t *r, xfs_fsblock_t v);
 223 extern void xfs_bmbt_set_startoff(xfs_bmbt_rec_host_t *r, xfs_fileoff_t v);
 224 extern void xfs_bmbt_set_state(xfs_bmbt_rec_host_t *r, xfs_exntst_t v);
 225
 226 extern 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
 229 extern void xfs_bmbt_to_bmdr(struct xfs_mount *, struct xfs_btree_block *, int,
 230                         xfs_bmdr_block_t *, int);
 231
 232 extern int xfs_bmbt_get_maxrecs(struct xfs_btree_cur *, int level);
 233 extern int xfs_bmdr_maxrecs(struct xfs_mount *, int blocklen, int leaf);
 234 extern int xfs_bmbt_maxrecs(struct xfs_mount *, int blocklen, int leaf);
 235
 236 extern 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__ */