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 #define XFS_BMAP_CRC_MAGIC      0x424d4133      /* 'BMA3' */
  23
  24 struct xfs_btree_cur;
  25 struct xfs_btree_block;
  26 struct xfs_mount;
  27 struct xfs_inode;
  28 struct xfs_trans;
  29
  30 /*
  31  * Bmap root header, on-disk form only.
  32  */
  33 typedef struct xfs_bmdr_block {
  34         __be16          bb_level;       /* 0 is a leaf */
  35         __be16          bb_numrecs;     /* current # of data records */
  36 } xfs_bmdr_block_t;
  37
  38 /*
  39  * Bmap btree record and extent descriptor.
  40  *  l0:63 is an extent flag (value 1 indicates non-normal).
  41  *  l0:9-62 are startoff.
  42  *  l0:0-8 and l1:21-63 are startblock.
  43  *  l1:0-20 are blockcount.
  44  */
  45 #define BMBT_EXNTFLAG_BITLEN    1
  46 #define BMBT_STARTOFF_BITLEN    54
  47 #define BMBT_STARTBLOCK_BITLEN  52
  48 #define BMBT_BLOCKCOUNT_BITLEN  21
  49
  50 typedef struct xfs_bmbt_rec {
  51         __be64                  l0, l1;
  52 } xfs_bmbt_rec_t;
  53
  54 typedef __uint64_t      xfs_bmbt_rec_base_t;    /* use this for casts */
  55 typedef xfs_bmbt_rec_t xfs_bmdr_rec_t;
  56
  57 typedef struct xfs_bmbt_rec_host {
  58         __uint64_t              l0, l1;
  59 } xfs_bmbt_rec_host_t;
  60
  61 /*
  62  * Values and macros for delayed-allocation startblock fields.
  63  */
  64 #define STARTBLOCKVALBITS       17
  65 #define STARTBLOCKMASKBITS      (15 + XFS_BIG_BLKNOS * 20)
  66 #define DSTARTBLOCKMASKBITS     (15 + 20)
  67 #define STARTBLOCKMASK          \
  68         (((((xfs_fsblock_t)1) << STARTBLOCKMASKBITS) - 1) << STARTBLOCKVALBITS)
  69 #define DSTARTBLOCKMASK         \
  70         (((((xfs_dfsbno_t)1) << DSTARTBLOCKMASKBITS) - 1) << STARTBLOCKVALBITS)
  71
  72 static inline int isnullstartblock(xfs_fsblock_t x)
  73 {
  74         return ((x) & STARTBLOCKMASK) == STARTBLOCKMASK;
  75 }
  76
  77 static inline int isnulldstartblock(xfs_dfsbno_t x)
  78 {
  79         return ((x) & DSTARTBLOCKMASK) == DSTARTBLOCKMASK;
  80 }
  81
  82 static inline xfs_fsblock_t nullstartblock(int k)
  83 {
  84         ASSERT(k < (1 << STARTBLOCKVALBITS));
  85         return STARTBLOCKMASK | (k);
  86 }
  87
  88 static inline xfs_filblks_t startblockval(xfs_fsblock_t x)
  89 {
  90         return (xfs_filblks_t)((x) & ~STARTBLOCKMASK);
  91 }
  92
  93 /*
  94  * Possible extent formats.
  95  */
  96 typedef enum {
  97         XFS_EXTFMT_NOSTATE = 0,
  98         XFS_EXTFMT_HASSTATE
  99 } xfs_exntfmt_t;
 100
 101 /*
 102  * Possible extent states.
 103  */
 104 typedef enum {
 105         XFS_EXT_NORM, XFS_EXT_UNWRITTEN,
 106         XFS_EXT_DMAPI_OFFLINE, XFS_EXT_INVALID
 107 } xfs_exntst_t;
 108
 109 /*
 110  * Extent state and extent format macros.
 111  */
 112 #define XFS_EXTFMT_INODE(x)     \
 113         (xfs_sb_version_hasextflgbit(&((x)->i_mount->m_sb)) ? \
 114                 XFS_EXTFMT_HASSTATE : XFS_EXTFMT_NOSTATE)
 115 #define ISUNWRITTEN(x)  ((x)->br_state == XFS_EXT_UNWRITTEN)
 116
 117 /*
 118  * Incore version of above.
 119  */
 120 typedef struct xfs_bmbt_irec
 121 {
 122         xfs_fileoff_t   br_startoff;    /* starting file offset */
 123         xfs_fsblock_t   br_startblock;  /* starting block number */
 124         xfs_filblks_t   br_blockcount;  /* number of blocks */
 125         xfs_exntst_t    br_state;       /* extent state */
 126 } xfs_bmbt_irec_t;
 127
 128 /*
 129  * Key structure for non-leaf levels of the tree.
 130  */
 131 typedef struct xfs_bmbt_key {
 132         __be64          br_startoff;    /* starting file offset */
 133 } xfs_bmbt_key_t, xfs_bmdr_key_t;
 134
 135 /* btree pointer type */
 136 typedef __be64 xfs_bmbt_ptr_t, xfs_bmdr_ptr_t;
 137
 138 /*
 139  * Btree block header size depends on a superblock flag.
 140  */
 141 #define XFS_BMBT_BLOCK_LEN(mp) \
 142         (xfs_sb_version_hascrc(&((mp)->m_sb)) ? \
 143                 XFS_BTREE_LBLOCK_CRC_LEN : XFS_BTREE_LBLOCK_LEN)
 144
 145 #define XFS_BMBT_REC_ADDR(mp, block, index) \
 146         ((xfs_bmbt_rec_t *) \
 147                 ((char *)(block) + \
 148                  XFS_BMBT_BLOCK_LEN(mp) + \
 149                  ((index) - 1) * sizeof(xfs_bmbt_rec_t)))
 150
 151 #define XFS_BMBT_KEY_ADDR(mp, block, index) \
 152         ((xfs_bmbt_key_t *) \
 153                 ((char *)(block) + \
 154                  XFS_BMBT_BLOCK_LEN(mp) + \
 155                  ((index) - 1) * sizeof(xfs_bmbt_key_t)))
 156
 157 #define XFS_BMBT_PTR_ADDR(mp, block, index, maxrecs) \
 158         ((xfs_bmbt_ptr_t *) \
 159                 ((char *)(block) + \
 160                  XFS_BMBT_BLOCK_LEN(mp) + \
 161                  (maxrecs) * sizeof(xfs_bmbt_key_t) + \
 162                  ((index) - 1) * sizeof(xfs_bmbt_ptr_t)))
 163
 164 #define XFS_BMDR_REC_ADDR(block, index) \
 165         ((xfs_bmdr_rec_t *) \
 166                 ((char *)(block) + \
 167                  sizeof(struct xfs_bmdr_block) + \
 168                  ((index) - 1) * sizeof(xfs_bmdr_rec_t)))
 169
 170 #define XFS_BMDR_KEY_ADDR(block, index) \
 171         ((xfs_bmdr_key_t *) \
 172                 ((char *)(block) + \
 173                  sizeof(struct xfs_bmdr_block) + \
 174                  ((index) - 1) * sizeof(xfs_bmdr_key_t)))
 175
 176 #define XFS_BMDR_PTR_ADDR(block, index, maxrecs) \
 177         ((xfs_bmdr_ptr_t *) \
 178                 ((char *)(block) + \
 179                  sizeof(struct xfs_bmdr_block) + \
 180                  (maxrecs) * sizeof(xfs_bmdr_key_t) + \
 181                  ((index) - 1) * sizeof(xfs_bmdr_ptr_t)))
 182
 183 /*
 184  * These are to be used when we know the size of the block and
 185  * we don't have a cursor.
 186  */
 187 #define XFS_BMAP_BROOT_PTR_ADDR(mp, bb, i, sz) \
 188         XFS_BMBT_PTR_ADDR(mp, bb, i, xfs_bmbt_maxrecs(mp, sz, 0))
 189
 190 #define XFS_BMAP_BROOT_SPACE_CALC(mp, nrecs) \
 191         (int)(XFS_BMBT_BLOCK_LEN(mp) + \
 192                ((nrecs) * (sizeof(xfs_bmbt_key_t) + sizeof(xfs_bmbt_ptr_t))))
 193
 194 #define XFS_BMAP_BROOT_SPACE(mp, bb) \
 195         (XFS_BMAP_BROOT_SPACE_CALC(mp, be16_to_cpu((bb)->bb_numrecs)))
 196 #define XFS_BMDR_SPACE_CALC(nrecs) \
 197         (int)(sizeof(xfs_bmdr_block_t) + \
 198                ((nrecs) * (sizeof(xfs_bmbt_key_t) + sizeof(xfs_bmbt_ptr_t))))
 199
 200 /*
 201  * Maximum number of bmap btree levels.
 202  */
 203 #define XFS_BM_MAXLEVELS(mp,w)          ((mp)->m_bm_maxlevels[(w)])
 204
 205 /*
 206  * Prototypes for xfs_bmap.c to call.
 207  */
 208 extern void xfs_bmdr_to_bmbt(struct xfs_inode *, xfs_bmdr_block_t *, int,
 209                         struct xfs_btree_block *, int);
 210 extern void xfs_bmbt_get_all(xfs_bmbt_rec_host_t *r, xfs_bmbt_irec_t *s);
 211 extern xfs_filblks_t xfs_bmbt_get_blockcount(xfs_bmbt_rec_host_t *r);
 212 extern xfs_fsblock_t xfs_bmbt_get_startblock(xfs_bmbt_rec_host_t *r);
 213 extern xfs_fileoff_t xfs_bmbt_get_startoff(xfs_bmbt_rec_host_t *r);
 214 extern xfs_exntst_t xfs_bmbt_get_state(xfs_bmbt_rec_host_t *r);
 215
 216 extern xfs_filblks_t xfs_bmbt_disk_get_blockcount(xfs_bmbt_rec_t *r);
 217 extern xfs_fileoff_t xfs_bmbt_disk_get_startoff(xfs_bmbt_rec_t *r);
 218
 219 extern void xfs_bmbt_set_all(xfs_bmbt_rec_host_t *r, xfs_bmbt_irec_t *s);
 220 extern void xfs_bmbt_set_allf(xfs_bmbt_rec_host_t *r, xfs_fileoff_t o,
 221                         xfs_fsblock_t b, xfs_filblks_t c, xfs_exntst_t v);
 222 extern void xfs_bmbt_set_blockcount(xfs_bmbt_rec_host_t *r, xfs_filblks_t v);
 223 extern void xfs_bmbt_set_startblock(xfs_bmbt_rec_host_t *r, xfs_fsblock_t v);
 224 extern void xfs_bmbt_set_startoff(xfs_bmbt_rec_host_t *r, xfs_fileoff_t v);
 225 extern void xfs_bmbt_set_state(xfs_bmbt_rec_host_t *r, xfs_exntst_t v);
 226
 227 extern void xfs_bmbt_disk_set_allf(xfs_bmbt_rec_t *r, xfs_fileoff_t o,
 228                         xfs_fsblock_t b, xfs_filblks_t c, xfs_exntst_t v);
 229
 230 extern void xfs_bmbt_to_bmdr(struct xfs_mount *, struct xfs_btree_block *, int,
 231                         xfs_bmdr_block_t *, int);
 232
 233 extern int xfs_bmbt_get_maxrecs(struct xfs_btree_cur *, int level);
 234 extern int xfs_bmdr_maxrecs(struct xfs_mount *, int blocklen, int leaf);
 235 extern int xfs_bmbt_maxrecs(struct xfs_mount *, int blocklen, int leaf);
 236
 237 extern struct xfs_btree_cur *xfs_bmbt_init_cursor(struct xfs_mount *,
 238                 struct xfs_trans *, struct xfs_inode *, int);
 239
 240 extern const struct xfs_buf_ops xfs_bmbt_buf_ops;
 241
 242 #endif  /* __XFS_BMAP_BTREE_H__ */