Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright (c) 2000, 2002 Silicon Graphics, Inc. All Rights Reserved. |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or modify it |
| 5 | * under the terms of version 2 of the GNU General Public License as |
| 6 | * published by the Free Software Foundation. |
| 7 | * |
| 8 | * This program is distributed in the hope that it would be useful, but |
| 9 | * WITHOUT ANY WARRANTY; without even the implied warranty of |
| 10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. |
| 11 | * |
| 12 | * Further, this software is distributed without any warranty that it is |
| 13 | * free of the rightful claim of any third person regarding infringement |
| 14 | * or the like. Any license provided herein, whether implied or |
| 15 | * otherwise, applies only to this software file. Patent licenses, if |
| 16 | * any, provided herein do not apply to combinations of this program with |
| 17 | * other software, or any other product whatsoever. |
| 18 | * |
| 19 | * You should have received a copy of the GNU General Public License along |
| 20 | * with this program; if not, write the Free Software Foundation, Inc., 59 |
| 21 | * Temple Place - Suite 330, Boston MA 02111-1307, USA. |
| 22 | * |
| 23 | * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy, |
| 24 | * Mountain View, CA 94043, or: |
| 25 | * |
| 26 | * http://www.sgi.com |
| 27 | * |
| 28 | * For further information regarding this notice, see: |
| 29 | * |
| 30 | * http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/ |
| 31 | */ |
| 32 | #ifndef __XFS_DA_BTREE_H__ |
| 33 | #define __XFS_DA_BTREE_H__ |
| 34 | |
| 35 | struct xfs_buf; |
| 36 | struct xfs_bmap_free; |
| 37 | struct xfs_inode; |
| 38 | struct xfs_mount; |
| 39 | struct xfs_trans; |
| 40 | struct zone; |
| 41 | |
| 42 | /*======================================================================== |
| 43 | * Directory Structure when greater than XFS_LBSIZE(mp) bytes. |
| 44 | *========================================================================*/ |
| 45 | |
| 46 | /* |
| 47 | * This structure is common to both leaf nodes and non-leaf nodes in the Btree. |
| 48 | * |
| 49 | * Is is used to manage a doubly linked list of all blocks at the same |
| 50 | * level in the Btree, and to identify which type of block this is. |
| 51 | */ |
| 52 | #define XFS_DA_NODE_MAGIC 0xfebe /* magic number: non-leaf blocks */ |
| 53 | #define XFS_DIR_LEAF_MAGIC 0xfeeb /* magic number: directory leaf blks */ |
| 54 | #define XFS_ATTR_LEAF_MAGIC 0xfbee /* magic number: attribute leaf blks */ |
| 55 | #define XFS_DIR2_LEAF1_MAGIC 0xd2f1 /* magic number: v2 dirlf single blks */ |
| 56 | #define XFS_DIR2_LEAFN_MAGIC 0xd2ff /* magic number: v2 dirlf multi blks */ |
| 57 | |
| 58 | #define XFS_DIRX_LEAF_MAGIC(mp) \ |
| 59 | (XFS_DIR_IS_V1(mp) ? XFS_DIR_LEAF_MAGIC : XFS_DIR2_LEAFN_MAGIC) |
| 60 | |
| 61 | typedef struct xfs_da_blkinfo { |
| 62 | xfs_dablk_t forw; /* previous block in list */ |
| 63 | xfs_dablk_t back; /* following block in list */ |
| 64 | __uint16_t magic; /* validity check on block */ |
| 65 | __uint16_t pad; /* unused */ |
| 66 | } xfs_da_blkinfo_t; |
| 67 | |
| 68 | /* |
| 69 | * This is the structure of the root and intermediate nodes in the Btree. |
| 70 | * The leaf nodes are defined above. |
| 71 | * |
| 72 | * Entries are not packed. |
| 73 | * |
| 74 | * Since we have duplicate keys, use a binary search but always follow |
| 75 | * all match in the block, not just the first match found. |
| 76 | */ |
| 77 | #define XFS_DA_NODE_MAXDEPTH 5 /* max depth of Btree */ |
| 78 | |
| 79 | typedef struct xfs_da_intnode { |
| 80 | struct xfs_da_node_hdr { /* constant-structure header block */ |
| 81 | xfs_da_blkinfo_t info; /* block type, links, etc. */ |
| 82 | __uint16_t count; /* count of active entries */ |
| 83 | __uint16_t level; /* level above leaves (leaf == 0) */ |
| 84 | } hdr; |
| 85 | struct xfs_da_node_entry { |
| 86 | xfs_dahash_t hashval; /* hash value for this descendant */ |
| 87 | xfs_dablk_t before; /* Btree block before this key */ |
| 88 | } btree[1]; /* variable sized array of keys */ |
| 89 | } xfs_da_intnode_t; |
| 90 | typedef struct xfs_da_node_hdr xfs_da_node_hdr_t; |
| 91 | typedef struct xfs_da_node_entry xfs_da_node_entry_t; |
| 92 | |
| 93 | #define XFS_DA_MAXHASH ((xfs_dahash_t)-1) /* largest valid hash value */ |
| 94 | |
| 95 | /* |
| 96 | * Macros used by directory code to interface to the filesystem. |
| 97 | */ |
| 98 | #if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_LBSIZE) |
| 99 | int xfs_lbsize(struct xfs_mount *mp); |
| 100 | #define XFS_LBSIZE(mp) xfs_lbsize(mp) |
| 101 | #else |
| 102 | #define XFS_LBSIZE(mp) ((mp)->m_sb.sb_blocksize) |
| 103 | #endif |
| 104 | #if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_LBLOG) |
| 105 | int xfs_lblog(struct xfs_mount *mp); |
| 106 | #define XFS_LBLOG(mp) xfs_lblog(mp) |
| 107 | #else |
| 108 | #define XFS_LBLOG(mp) ((mp)->m_sb.sb_blocklog) |
| 109 | #endif |
| 110 | |
| 111 | /* |
| 112 | * Macros used by directory code to interface to the kernel |
| 113 | */ |
| 114 | |
| 115 | /* |
| 116 | * Macros used to manipulate directory off_t's |
| 117 | */ |
| 118 | #if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_DA_MAKE_BNOENTRY) |
| 119 | __uint32_t xfs_da_make_bnoentry(struct xfs_mount *mp, xfs_dablk_t bno, |
| 120 | int entry); |
| 121 | #define XFS_DA_MAKE_BNOENTRY(mp,bno,entry) \ |
| 122 | xfs_da_make_bnoentry(mp,bno,entry) |
| 123 | #else |
| 124 | #define XFS_DA_MAKE_BNOENTRY(mp,bno,entry) \ |
| 125 | (((bno) << (mp)->m_dircook_elog) | (entry)) |
| 126 | #endif |
| 127 | #if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_DA_MAKE_COOKIE) |
| 128 | xfs_off_t xfs_da_make_cookie(struct xfs_mount *mp, xfs_dablk_t bno, int entry, |
| 129 | xfs_dahash_t hash); |
| 130 | #define XFS_DA_MAKE_COOKIE(mp,bno,entry,hash) \ |
| 131 | xfs_da_make_cookie(mp,bno,entry,hash) |
| 132 | #else |
| 133 | #define XFS_DA_MAKE_COOKIE(mp,bno,entry,hash) \ |
| 134 | (((xfs_off_t)XFS_DA_MAKE_BNOENTRY(mp, bno, entry) << 32) | (hash)) |
| 135 | #endif |
| 136 | #if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_DA_COOKIE_HASH) |
| 137 | xfs_dahash_t xfs_da_cookie_hash(struct xfs_mount *mp, xfs_off_t cookie); |
| 138 | #define XFS_DA_COOKIE_HASH(mp,cookie) xfs_da_cookie_hash(mp,cookie) |
| 139 | #else |
| 140 | #define XFS_DA_COOKIE_HASH(mp,cookie) ((xfs_dahash_t)(cookie)) |
| 141 | #endif |
| 142 | #if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_DA_COOKIE_BNO) |
| 143 | xfs_dablk_t xfs_da_cookie_bno(struct xfs_mount *mp, xfs_off_t cookie); |
| 144 | #define XFS_DA_COOKIE_BNO(mp,cookie) xfs_da_cookie_bno(mp,cookie) |
| 145 | #else |
| 146 | #define XFS_DA_COOKIE_BNO(mp,cookie) \ |
| 147 | (((xfs_off_t)(cookie) >> 31) == -1LL ? \ |
| 148 | (xfs_dablk_t)0 : \ |
| 149 | (xfs_dablk_t)((xfs_off_t)(cookie) >> ((mp)->m_dircook_elog + 32))) |
| 150 | #endif |
| 151 | #if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_DA_COOKIE_ENTRY) |
| 152 | int xfs_da_cookie_entry(struct xfs_mount *mp, xfs_off_t cookie); |
| 153 | #define XFS_DA_COOKIE_ENTRY(mp,cookie) xfs_da_cookie_entry(mp,cookie) |
| 154 | #else |
| 155 | #define XFS_DA_COOKIE_ENTRY(mp,cookie) \ |
| 156 | (((xfs_off_t)(cookie) >> 31) == -1LL ? \ |
| 157 | (xfs_dablk_t)0 : \ |
| 158 | (xfs_dablk_t)(((xfs_off_t)(cookie) >> 32) & \ |
| 159 | ((1 << (mp)->m_dircook_elog) - 1))) |
| 160 | #endif |
| 161 | |
| 162 | |
| 163 | /*======================================================================== |
| 164 | * Btree searching and modification structure definitions. |
| 165 | *========================================================================*/ |
| 166 | |
| 167 | /* |
| 168 | * Structure to ease passing around component names. |
| 169 | */ |
| 170 | typedef struct xfs_da_args { |
| 171 | uchar_t *name; /* string (maybe not NULL terminated) */ |
| 172 | int namelen; /* length of string (maybe no NULL) */ |
| 173 | uchar_t *value; /* set of bytes (maybe contain NULLs) */ |
| 174 | int valuelen; /* length of value */ |
| 175 | int flags; /* argument flags (eg: ATTR_NOCREATE) */ |
| 176 | xfs_dahash_t hashval; /* hash value of name */ |
| 177 | xfs_ino_t inumber; /* input/output inode number */ |
| 178 | struct xfs_inode *dp; /* directory inode to manipulate */ |
| 179 | xfs_fsblock_t *firstblock; /* ptr to firstblock for bmap calls */ |
| 180 | struct xfs_bmap_free *flist; /* ptr to freelist for bmap_finish */ |
| 181 | struct xfs_trans *trans; /* current trans (changes over time) */ |
| 182 | xfs_extlen_t total; /* total blocks needed, for 1st bmap */ |
| 183 | int whichfork; /* data or attribute fork */ |
| 184 | xfs_dablk_t blkno; /* blkno of attr leaf of interest */ |
| 185 | int index; /* index of attr of interest in blk */ |
| 186 | xfs_dablk_t rmtblkno; /* remote attr value starting blkno */ |
| 187 | int rmtblkcnt; /* remote attr value block count */ |
| 188 | xfs_dablk_t blkno2; /* blkno of 2nd attr leaf of interest */ |
| 189 | int index2; /* index of 2nd attr in blk */ |
| 190 | xfs_dablk_t rmtblkno2; /* remote attr value starting blkno */ |
| 191 | int rmtblkcnt2; /* remote attr value block count */ |
| 192 | unsigned char justcheck; /* T/F: check for ok with no space */ |
| 193 | unsigned char rename; /* T/F: this is an atomic rename op */ |
| 194 | unsigned char addname; /* T/F: this is an add operation */ |
| 195 | unsigned char oknoent; /* T/F: ok to return ENOENT, else die */ |
| 196 | } xfs_da_args_t; |
| 197 | |
| 198 | /* |
| 199 | * Structure to describe buffer(s) for a block. |
| 200 | * This is needed in the directory version 2 format case, when |
| 201 | * multiple non-contiguous fsblocks might be needed to cover one |
| 202 | * logical directory block. |
| 203 | * If the buffer count is 1 then the data pointer points to the |
| 204 | * same place as the b_addr field for the buffer, else to kmem_alloced memory. |
| 205 | */ |
| 206 | typedef struct xfs_dabuf { |
| 207 | int nbuf; /* number of buffer pointers present */ |
| 208 | short dirty; /* data needs to be copied back */ |
| 209 | short bbcount; /* how large is data in bbs */ |
| 210 | void *data; /* pointer for buffers' data */ |
| 211 | #ifdef XFS_DABUF_DEBUG |
| 212 | inst_t *ra; /* return address of caller to make */ |
| 213 | struct xfs_dabuf *next; /* next in global chain */ |
| 214 | struct xfs_dabuf *prev; /* previous in global chain */ |
| 215 | struct xfs_buftarg *target; /* device for buffer */ |
| 216 | xfs_daddr_t blkno; /* daddr first in bps[0] */ |
| 217 | #endif |
| 218 | struct xfs_buf *bps[1]; /* actually nbuf of these */ |
| 219 | } xfs_dabuf_t; |
| 220 | #define XFS_DA_BUF_SIZE(n) \ |
| 221 | (sizeof(xfs_dabuf_t) + sizeof(struct xfs_buf *) * ((n) - 1)) |
| 222 | |
| 223 | #ifdef XFS_DABUF_DEBUG |
| 224 | extern xfs_dabuf_t *xfs_dabuf_global_list; |
| 225 | #endif |
| 226 | |
| 227 | /* |
| 228 | * Storage for holding state during Btree searches and split/join ops. |
| 229 | * |
| 230 | * Only need space for 5 intermediate nodes. With a minimum of 62-way |
| 231 | * fanout to the Btree, we can support over 900 million directory blocks, |
| 232 | * which is slightly more than enough. |
| 233 | */ |
| 234 | typedef struct xfs_da_state_blk { |
| 235 | xfs_dabuf_t *bp; /* buffer containing block */ |
| 236 | xfs_dablk_t blkno; /* filesystem blkno of buffer */ |
| 237 | xfs_daddr_t disk_blkno; /* on-disk blkno (in BBs) of buffer */ |
| 238 | int index; /* relevant index into block */ |
| 239 | xfs_dahash_t hashval; /* last hash value in block */ |
| 240 | int magic; /* blk's magic number, ie: blk type */ |
| 241 | } xfs_da_state_blk_t; |
| 242 | |
| 243 | typedef struct xfs_da_state_path { |
| 244 | int active; /* number of active levels */ |
| 245 | xfs_da_state_blk_t blk[XFS_DA_NODE_MAXDEPTH]; |
| 246 | } xfs_da_state_path_t; |
| 247 | |
| 248 | typedef struct xfs_da_state { |
| 249 | xfs_da_args_t *args; /* filename arguments */ |
| 250 | struct xfs_mount *mp; /* filesystem mount point */ |
| 251 | unsigned int blocksize; /* logical block size */ |
| 252 | unsigned int node_ents; /* how many entries in danode */ |
| 253 | xfs_da_state_path_t path; /* search/split paths */ |
| 254 | xfs_da_state_path_t altpath; /* alternate path for join */ |
| 255 | unsigned char inleaf; /* insert into 1->lf, 0->splf */ |
| 256 | unsigned char extravalid; /* T/F: extrablk is in use */ |
| 257 | unsigned char extraafter; /* T/F: extrablk is after new */ |
| 258 | xfs_da_state_blk_t extrablk; /* for double-splits on leafs */ |
| 259 | /* for dirv2 extrablk is data */ |
| 260 | } xfs_da_state_t; |
| 261 | |
| 262 | /* |
| 263 | * Utility macros to aid in logging changed structure fields. |
| 264 | */ |
| 265 | #define XFS_DA_LOGOFF(BASE, ADDR) ((char *)(ADDR) - (char *)(BASE)) |
| 266 | #define XFS_DA_LOGRANGE(BASE, ADDR, SIZE) \ |
| 267 | (uint)(XFS_DA_LOGOFF(BASE, ADDR)), \ |
| 268 | (uint)(XFS_DA_LOGOFF(BASE, ADDR)+(SIZE)-1) |
| 269 | |
| 270 | |
| 271 | #ifdef __KERNEL__ |
| 272 | /*======================================================================== |
| 273 | * Function prototypes for the kernel. |
| 274 | *========================================================================*/ |
| 275 | |
| 276 | /* |
| 277 | * Routines used for growing the Btree. |
| 278 | */ |
| 279 | int xfs_da_node_create(xfs_da_args_t *args, xfs_dablk_t blkno, int level, |
| 280 | xfs_dabuf_t **bpp, int whichfork); |
| 281 | int xfs_da_split(xfs_da_state_t *state); |
| 282 | |
| 283 | /* |
| 284 | * Routines used for shrinking the Btree. |
| 285 | */ |
| 286 | int xfs_da_join(xfs_da_state_t *state); |
| 287 | void xfs_da_fixhashpath(xfs_da_state_t *state, |
| 288 | xfs_da_state_path_t *path_to_to_fix); |
| 289 | |
| 290 | /* |
| 291 | * Routines used for finding things in the Btree. |
| 292 | */ |
| 293 | int xfs_da_node_lookup_int(xfs_da_state_t *state, int *result); |
| 294 | int xfs_da_path_shift(xfs_da_state_t *state, xfs_da_state_path_t *path, |
| 295 | int forward, int release, int *result); |
| 296 | /* |
| 297 | * Utility routines. |
| 298 | */ |
| 299 | int xfs_da_blk_unlink(xfs_da_state_t *state, xfs_da_state_blk_t *drop_blk, |
| 300 | xfs_da_state_blk_t *save_blk); |
| 301 | int xfs_da_blk_link(xfs_da_state_t *state, xfs_da_state_blk_t *old_blk, |
| 302 | xfs_da_state_blk_t *new_blk); |
| 303 | |
| 304 | /* |
| 305 | * Utility routines. |
| 306 | */ |
| 307 | int xfs_da_grow_inode(xfs_da_args_t *args, xfs_dablk_t *new_blkno); |
| 308 | int xfs_da_get_buf(struct xfs_trans *trans, struct xfs_inode *dp, |
| 309 | xfs_dablk_t bno, xfs_daddr_t mappedbno, |
| 310 | xfs_dabuf_t **bp, int whichfork); |
| 311 | int xfs_da_read_buf(struct xfs_trans *trans, struct xfs_inode *dp, |
| 312 | xfs_dablk_t bno, xfs_daddr_t mappedbno, |
| 313 | xfs_dabuf_t **bpp, int whichfork); |
| 314 | xfs_daddr_t xfs_da_reada_buf(struct xfs_trans *trans, struct xfs_inode *dp, |
| 315 | xfs_dablk_t bno, int whichfork); |
| 316 | int xfs_da_shrink_inode(xfs_da_args_t *args, xfs_dablk_t dead_blkno, |
| 317 | xfs_dabuf_t *dead_buf); |
| 318 | |
| 319 | uint xfs_da_hashname(uchar_t *name_string, int name_length); |
| 320 | uint xfs_da_log2_roundup(uint i); |
| 321 | xfs_da_state_t *xfs_da_state_alloc(void); |
| 322 | void xfs_da_state_free(xfs_da_state_t *state); |
| 323 | void xfs_da_state_kill_altpath(xfs_da_state_t *state); |
| 324 | |
| 325 | void xfs_da_buf_done(xfs_dabuf_t *dabuf); |
| 326 | void xfs_da_log_buf(struct xfs_trans *tp, xfs_dabuf_t *dabuf, uint first, |
| 327 | uint last); |
| 328 | void xfs_da_brelse(struct xfs_trans *tp, xfs_dabuf_t *dabuf); |
| 329 | void xfs_da_binval(struct xfs_trans *tp, xfs_dabuf_t *dabuf); |
| 330 | xfs_daddr_t xfs_da_blkno(xfs_dabuf_t *dabuf); |
| 331 | |
| 332 | extern struct kmem_zone *xfs_da_state_zone; |
| 333 | #endif /* __KERNEL__ */ |
| 334 | |
| 335 | #endif /* __XFS_DA_BTREE_H__ */ |