fs/jfs/jfs_btree.h

   1 /*
   2  *   Copyright (C) International Business Machines Corp., 2000-2004
   3  *
   4  *   This program is free software;  you can redistribute it and/or modify
   5  *   it under the terms of the GNU General Public License as published by
   6  *   the Free Software Foundation; either version 2 of the License, or
   7  *   (at your option) any later version.
   8  *
   9  *   This program is distributed in the hope that it will be useful,
  10  *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
  11  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
  12  *   the 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 to the Free Software
  16  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  17  */
  18 #ifndef _H_JFS_BTREE
  19 #define _H_JFS_BTREE
  20
  21 /*
  22  *      jfs_btree.h: B+-tree
  23  *
  24  * JFS B+-tree (dtree and xtree) common definitions
  25  */
  26
  27 /*
  28  *      basic btree page - btpage
  29  *
  30 struct btpage {
  31         s64 next;               right sibling bn
  32         s64 prev;               left sibling bn
  33
  34         u8 flag;
  35         u8 rsrvd[7];            type specific
  36         s64 self;               self address
  37
  38         u8 entry[4064];
  39 };                                              */
  40
  41 /* btpaget_t flag */
  42 #define BT_TYPE         0x07    /* B+-tree index */
  43 #define BT_ROOT         0x01    /* root page */
  44 #define BT_LEAF         0x02    /* leaf page */
  45 #define BT_INTERNAL     0x04    /* internal page */
  46 #define BT_RIGHTMOST    0x10    /* rightmost page */
  47 #define BT_LEFTMOST     0x20    /* leftmost page */
  48 #define BT_SWAPPED      0x80    /* used by fsck for endian swapping */
  49
  50 /* btorder (in inode) */
  51 #define BT_RANDOM               0x0000
  52 #define BT_SEQUENTIAL           0x0001
  53 #define BT_LOOKUP               0x0010
  54 #define BT_INSERT               0x0020
  55 #define BT_DELETE               0x0040
  56
  57 /*
  58  *      btree page buffer cache access
  59  */
  60 #define BT_IS_ROOT(MP) (((MP)->xflag & COMMIT_PAGE) == 0)
  61
  62 /* get page from buffer page */
  63 #define BT_PAGE(IP, MP, TYPE, ROOT)\
  64         (BT_IS_ROOT(MP) ? (TYPE *)&JFS_IP(IP)->ROOT : (TYPE *)(MP)->data)
  65
  66 /* get the page buffer and the page for specified block address */
  67 #define BT_GETPAGE(IP, BN, MP, TYPE, SIZE, P, RC, ROOT)\
  68 {\
  69         if ((BN) == 0)\
  70         {\
  71                 MP = (struct metapage *)&JFS_IP(IP)->bxflag;\
  72                 P = (TYPE *)&JFS_IP(IP)->ROOT;\
  73                 RC = 0;\
  74         }\
  75         else\
  76         {\
  77                 MP = read_metapage((IP), BN, SIZE, 1);\
  78                 if (MP) {\
  79                         RC = 0;\
  80                         P = (MP)->data;\
  81                 } else {\
  82                         P = NULL;\
  83                         jfs_err("bread failed!");\
  84                         RC = -EIO;\
  85                 }\
  86         }\
  87 }
  88
  89 #define BT_MARK_DIRTY(MP, IP)\
  90 {\
  91         if (BT_IS_ROOT(MP))\
  92                 mark_inode_dirty(IP);\
  93         else\
  94                 mark_metapage_dirty(MP);\
  95 }
  96
  97 /* put the page buffer */
  98 #define BT_PUTPAGE(MP)\
  99 {\
 100         if (! BT_IS_ROOT(MP)) \
 101                 release_metapage(MP); \
 102 }
 103
 104
 105 /*
 106  *      btree traversal stack
 107  *
 108  * record the path traversed during the search;
 109  * top frame record the leaf page/entry selected.
 110  */
 111 struct btframe {        /* stack frame */
 112         s64 bn;                 /* 8: */
 113         s16 index;              /* 2: */
 114         s16 lastindex;          /* 2: unused */
 115         struct metapage *mp;    /* 4/8: */
 116 };                              /* (16/24) */
 117
 118 struct btstack {
 119         struct btframe *top;
 120         int nsplit;
 121         struct btframe stack[MAXTREEHEIGHT];
 122 };
 123
 124 #define BT_CLR(btstack)\
 125         (btstack)->top = (btstack)->stack
 126
 127 #define BT_STACK_FULL(btstack)\
 128         ( (btstack)->top == &((btstack)->stack[MAXTREEHEIGHT-1]))
 129
 130 #define BT_PUSH(BTSTACK, BN, INDEX)\
 131 {\
 132         assert(!BT_STACK_FULL(BTSTACK));\
 133         (BTSTACK)->top->bn = BN;\
 134         (BTSTACK)->top->index = INDEX;\
 135         ++(BTSTACK)->top;\
 136 }
 137
 138 #define BT_POP(btstack)\
 139         ( (btstack)->top == (btstack)->stack ? NULL : --(btstack)->top )
 140
 141 #define BT_STACK(btstack)\
 142         ( (btstack)->top == (btstack)->stack ? NULL : (btstack)->top )
 143
 144 static inline void BT_STACK_DUMP(struct btstack *btstack)
 145 {
 146         int i;
 147         printk("btstack dump:\n");
 148         for (i = 0; i < MAXTREEHEIGHT; i++)
 149                 printk(KERN_ERR "bn = %Lx, index = %d\n",
 150                        (long long)btstack->stack[i].bn,
 151                        btstack->stack[i].index);
 152 }
 153
 154 /* retrieve search results */
 155 #define BT_GETSEARCH(IP, LEAF, BN, MP, TYPE, P, INDEX, ROOT)\
 156 {\
 157         BN = (LEAF)->bn;\
 158         MP = (LEAF)->mp;\
 159         if (BN)\
 160                 P = (TYPE *)MP->data;\
 161         else\
 162                 P = (TYPE *)&JFS_IP(IP)->ROOT;\
 163         INDEX = (LEAF)->index;\
 164 }
 165
 166 /* put the page buffer of search */
 167 #define BT_PUTSEARCH(BTSTACK)\
 168 {\
 169         if (! BT_IS_ROOT((BTSTACK)->top->mp))\
 170                 release_metapage((BTSTACK)->top->mp);\
 171 }
 172 #endif                          /* _H_JFS_BTREE */