linux/fs/jfs/jfs_dtree.h
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   1/*
   2 *   Copyright (C) International Business Machines Corp., 2000-2002
   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_DTREE
  19#define _H_JFS_DTREE
  20
  21/*
  22 *      jfs_dtree.h: directory B+-tree manager
  23 */
  24
  25#include "jfs_btree.h"
  26
  27typedef union {
  28        struct {
  29                tid_t tid;
  30                struct inode *ip;
  31                u32 ino;
  32        } leaf;
  33        pxd_t xd;
  34} ddata_t;
  35
  36
  37/*
  38 *      entry segment/slot
  39 *
  40 * an entry consists of type dependent head/only segment/slot and
  41 * additional segments/slots linked vi next field;
  42 * N.B. last/only segment of entry is terminated by next = -1;
  43 */
  44/*
  45 *      directory page slot
  46 */
  47struct dtslot {
  48        s8 next;                /* 1: */
  49        s8 cnt;                 /* 1: */
  50        __le16 name[15];        /* 30: */
  51};                              /* (32) */
  52
  53
  54#define DATASLOTSIZE    16
  55#define L2DATASLOTSIZE  4
  56#define DTSLOTSIZE      32
  57#define L2DTSLOTSIZE    5
  58#define DTSLOTHDRSIZE   2
  59#define DTSLOTDATASIZE  30
  60#define DTSLOTDATALEN   15
  61
  62/*
  63 *       internal node entry head/only segment
  64 */
  65struct idtentry {
  66        pxd_t xd;               /* 8: child extent descriptor */
  67
  68        s8 next;                /* 1: */
  69        u8 namlen;              /* 1: */
  70        __le16 name[11];        /* 22: 2-byte aligned */
  71};                              /* (32) */
  72
  73#define DTIHDRSIZE      10
  74#define DTIHDRDATALEN   11
  75
  76/* compute number of slots for entry */
  77#define NDTINTERNAL(klen) (DIV_ROUND_UP((4 + (klen)), 15))
  78
  79
  80/*
  81 *      leaf node entry head/only segment
  82 *
  83 *      For legacy filesystems, name contains 13 wchars -- no index field
  84 */
  85struct ldtentry {
  86        __le32 inumber;         /* 4: 4-byte aligned */
  87        s8 next;                /* 1: */
  88        u8 namlen;              /* 1: */
  89        __le16 name[11];        /* 22: 2-byte aligned */
  90        __le32 index;           /* 4: index into dir_table */
  91};                              /* (32) */
  92
  93#define DTLHDRSIZE      6
  94#define DTLHDRDATALEN_LEGACY    13      /* Old (OS/2) format */
  95#define DTLHDRDATALEN   11
  96
  97/*
  98 * dir_table used for directory traversal during readdir
  99 */
 100
 101/*
 102 * Keep persistent index for directory entries
 103 */
 104#define DO_INDEX(INODE) (JFS_SBI((INODE)->i_sb)->mntflag & JFS_DIR_INDEX)
 105
 106/*
 107 * Maximum entry in inline directory table
 108 */
 109#define MAX_INLINE_DIRTABLE_ENTRY 13
 110
 111struct dir_table_slot {
 112        u8 rsrvd;               /* 1: */
 113        u8 flag;                /* 1: 0 if free */
 114        u8 slot;                /* 1: slot within leaf page of entry */
 115        u8 addr1;               /* 1: upper 8 bits of leaf page address */
 116        __le32 addr2;           /* 4: lower 32 bits of leaf page address -OR-
 117                                   index of next entry when this entry was deleted */
 118};                              /* (8) */
 119
 120/*
 121 * flag values
 122 */
 123#define DIR_INDEX_VALID 1
 124#define DIR_INDEX_FREE 0
 125
 126#define DTSaddress(dir_table_slot, address64)\
 127{\
 128        (dir_table_slot)->addr1 = ((u64)address64) >> 32;\
 129        (dir_table_slot)->addr2 = __cpu_to_le32((address64) & 0xffffffff);\
 130}
 131
 132#define addressDTS(dts)\
 133        ( ((s64)((dts)->addr1)) << 32 | __le32_to_cpu((dts)->addr2) )
 134
 135/* compute number of slots for entry */
 136#define NDTLEAF_LEGACY(klen)    (DIV_ROUND_UP((2 + (klen)), 15))
 137#define NDTLEAF NDTINTERNAL
 138
 139
 140/*
 141 *      directory root page (in-line in on-disk inode):
 142 *
 143 * cf. dtpage_t below.
 144 */
 145typedef union {
 146        struct {
 147                struct dasd DASD; /* 16: DASD limit/usage info */
 148
 149                u8 flag;        /* 1: */
 150                u8 nextindex;   /* 1: next free entry in stbl */
 151                s8 freecnt;     /* 1: free count */
 152                s8 freelist;    /* 1: freelist header */
 153
 154                __le32 idotdot; /* 4: parent inode number */
 155
 156                s8 stbl[8];     /* 8: sorted entry index table */
 157        } header;               /* (32) */
 158
 159        struct dtslot slot[9];
 160} dtroot_t;
 161
 162#define PARENT(IP) \
 163        (le32_to_cpu(JFS_IP(IP)->i_dtroot.header.idotdot))
 164
 165#define DTROOTMAXSLOT   9
 166
 167#define dtEmpty(IP) (JFS_IP(IP)->i_dtroot.header.nextindex == 0)
 168
 169
 170/*
 171 *      directory regular page:
 172 *
 173 *      entry slot array of 32 byte slot
 174 *
 175 * sorted entry slot index table (stbl):
 176 * contiguous slots at slot specified by stblindex,
 177 * 1-byte per entry
 178 *   512 byte block:  16 entry tbl (1 slot)
 179 *  1024 byte block:  32 entry tbl (1 slot)
 180 *  2048 byte block:  64 entry tbl (2 slot)
 181 *  4096 byte block: 128 entry tbl (4 slot)
 182 *
 183 * data area:
 184 *   512 byte block:  16 - 2 =  14 slot
 185 *  1024 byte block:  32 - 2 =  30 slot
 186 *  2048 byte block:  64 - 3 =  61 slot
 187 *  4096 byte block: 128 - 5 = 123 slot
 188 *
 189 * N.B. index is 0-based; index fields refer to slot index
 190 * except nextindex which refers to entry index in stbl;
 191 * end of entry stot list or freelist is marked with -1.
 192 */
 193typedef union {
 194        struct {
 195                __le64 next;    /* 8: next sibling */
 196                __le64 prev;    /* 8: previous sibling */
 197
 198                u8 flag;        /* 1: */
 199                u8 nextindex;   /* 1: next entry index in stbl */
 200                s8 freecnt;     /* 1: */
 201                s8 freelist;    /* 1: slot index of head of freelist */
 202
 203                u8 maxslot;     /* 1: number of slots in page slot[] */
 204                u8 stblindex;   /* 1: slot index of start of stbl */
 205                u8 rsrvd[2];    /* 2: */
 206
 207                pxd_t self;     /* 8: self pxd */
 208        } header;               /* (32) */
 209
 210        struct dtslot slot[128];
 211} dtpage_t;
 212
 213#define DTPAGEMAXSLOT        128
 214
 215#define DT8THPGNODEBYTES     512
 216#define DT8THPGNODETSLOTS      1
 217#define DT8THPGNODESLOTS      16
 218
 219#define DTQTRPGNODEBYTES    1024
 220#define DTQTRPGNODETSLOTS      1
 221#define DTQTRPGNODESLOTS      32
 222
 223#define DTHALFPGNODEBYTES   2048
 224#define DTHALFPGNODETSLOTS     2
 225#define DTHALFPGNODESLOTS     64
 226
 227#define DTFULLPGNODEBYTES   4096
 228#define DTFULLPGNODETSLOTS     4
 229#define DTFULLPGNODESLOTS    128
 230
 231#define DTENTRYSTART    1
 232
 233/* get sorted entry table of the page */
 234#define DT_GETSTBL(p) ( ((p)->header.flag & BT_ROOT) ?\
 235        ((dtroot_t *)(p))->header.stbl : \
 236        (s8 *)&(p)->slot[(p)->header.stblindex] )
 237
 238/*
 239 * Flags for dtSearch
 240 */
 241#define JFS_CREATE 1
 242#define JFS_LOOKUP 2
 243#define JFS_REMOVE 3
 244#define JFS_RENAME 4
 245
 246/*
 247 * Maximum file offset for directories.
 248 */
 249#define DIREND  INT_MAX
 250
 251/*
 252 *      external declarations
 253 */
 254extern void dtInitRoot(tid_t tid, struct inode *ip, u32 idotdot);
 255
 256extern int dtSearch(struct inode *ip, struct component_name * key,
 257                    ino_t * data, struct btstack * btstack, int flag);
 258
 259extern int dtInsert(tid_t tid, struct inode *ip, struct component_name * key,
 260                    ino_t * ino, struct btstack * btstack);
 261
 262extern int dtDelete(tid_t tid, struct inode *ip, struct component_name * key,
 263                    ino_t * data, int flag);
 264
 265extern int dtModify(tid_t tid, struct inode *ip, struct component_name * key,
 266                    ino_t * orig_ino, ino_t new_ino, int flag);
 267
 268extern int jfs_readdir(struct file *filp, void *dirent, filldir_t filldir);
 269#endif                          /* !_H_JFS_DTREE */
 270
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