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_DA_BTREE_H__ 19 #define __XFS_DA_BTREE_H__ 20 21 struct xfs_buf; 22 struct xfs_bmap_free; 23 struct xfs_inode; 24 struct xfs_mount; 25 struct xfs_trans; 26 struct zone; 27 28 /*======================================================================== 29 * Directory Structure when greater than XFS_LBSIZE(mp) bytes. 30 *========================================================================*/ 31 32 /* 33 * This structure is common to both leaf nodes and non-leaf nodes in the Btree. 34 * 35 * Is is used to manage a doubly linked list of all blocks at the same 36 * level in the Btree, and to identify which type of block this is. 37 */ 38 #define XFS_DA_NODE_MAGIC 0xfebe /* magic number: non-leaf blocks */ 39 #define XFS_ATTR_LEAF_MAGIC 0xfbee /* magic number: attribute leaf blks */ 40 #define XFS_DIR2_LEAF1_MAGIC 0xd2f1 /* magic number: v2 dirlf single blks */ 41 #define XFS_DIR2_LEAFN_MAGIC 0xd2ff /* magic number: v2 dirlf multi blks */ 42 43 typedef struct xfs_da_blkinfo { 44 __be32 forw; /* previous block in list */ 45 __be32 back; /* following block in list */ 46 __be16 magic; /* validity check on block */ 47 __be16 pad; /* unused */ 48 } xfs_da_blkinfo_t; 49 50 /* 51 * This is the structure of the root and intermediate nodes in the Btree. 52 * The leaf nodes are defined above. 53 * 54 * Entries are not packed. 55 * 56 * Since we have duplicate keys, use a binary search but always follow 57 * all match in the block, not just the first match found. 58 */ 59 #define XFS_DA_NODE_MAXDEPTH 5 /* max depth of Btree */ 60 61 typedef struct xfs_da_intnode { 62 struct xfs_da_node_hdr { /* constant-structure header block */ 63 xfs_da_blkinfo_t info; /* block type, links, etc. */ 64 __be16 count; /* count of active entries */ 65 __be16 level; /* level above leaves (leaf == 0) */ 66 } hdr; 67 struct xfs_da_node_entry { 68 __be32 hashval; /* hash value for this descendant */ 69 __be32 before; /* Btree block before this key */ 70 } btree[1]; /* variable sized array of keys */ 71 } xfs_da_intnode_t; 72 typedef struct xfs_da_node_hdr xfs_da_node_hdr_t; 73 typedef struct xfs_da_node_entry xfs_da_node_entry_t; 74 75 #define XFS_LBSIZE(mp) (mp)->m_sb.sb_blocksize 76 77 /*======================================================================== 78 * Btree searching and modification structure definitions. 79 *========================================================================*/ 80 81 /* 82 * Search comparison results 83 */ 84 enum xfs_dacmp { 85 XFS_CMP_DIFFERENT, /* names are completely different */ 86 XFS_CMP_EXACT, /* names are exactly the same */ 87 XFS_CMP_CASE /* names are same but differ in case */ 88 }; 89 90 /* 91 * Structure to ease passing around component names. 92 */ 93 typedef struct xfs_da_args { 94 const __uint8_t *name; /* string (maybe not NULL terminated) */ 95 int namelen; /* length of string (maybe no NULL) */ 96 __uint8_t *value; /* set of bytes (maybe contain NULLs) */ 97 int valuelen; /* length of value */ 98 int flags; /* argument flags (eg: ATTR_NOCREATE) */ 99 xfs_dahash_t hashval; /* hash value of name */ 100 xfs_ino_t inumber; /* input/output inode number */ 101 struct xfs_inode *dp; /* directory inode to manipulate */ 102 xfs_fsblock_t *firstblock; /* ptr to firstblock for bmap calls */ 103 struct xfs_bmap_free *flist; /* ptr to freelist for bmap_finish */ 104 struct xfs_trans *trans; /* current trans (changes over time) */ 105 xfs_extlen_t total; /* total blocks needed, for 1st bmap */ 106 int whichfork; /* data or attribute fork */ 107 xfs_dablk_t blkno; /* blkno of attr leaf of interest */ 108 int index; /* index of attr of interest in blk */ 109 xfs_dablk_t rmtblkno; /* remote attr value starting blkno */ 110 int rmtblkcnt; /* remote attr value block count */ 111 xfs_dablk_t blkno2; /* blkno of 2nd attr leaf of interest */ 112 int index2; /* index of 2nd attr in blk */ 113 xfs_dablk_t rmtblkno2; /* remote attr value starting blkno */ 114 int rmtblkcnt2; /* remote attr value block count */ 115 int op_flags; /* operation flags */ 116 enum xfs_dacmp cmpresult; /* name compare result for lookups */ 117 } xfs_da_args_t; 118 119 /* 120 * Operation flags: 121 */ 122 #define XFS_DA_OP_JUSTCHECK 0x0001 /* check for ok with no space */ 123 #define XFS_DA_OP_RENAME 0x0002 /* this is an atomic rename op */ 124 #define XFS_DA_OP_ADDNAME 0x0004 /* this is an add operation */ 125 #define XFS_DA_OP_OKNOENT 0x0008 /* lookup/add op, ENOENT ok, else die */ 126 #define XFS_DA_OP_CILOOKUP 0x0010 /* lookup to return CI name if found */ 127 128 #define XFS_DA_OP_FLAGS \ 129 { XFS_DA_OP_JUSTCHECK, "JUSTCHECK" }, \ 130 { XFS_DA_OP_RENAME, "RENAME" }, \ 131 { XFS_DA_OP_ADDNAME, "ADDNAME" }, \ 132 { XFS_DA_OP_OKNOENT, "OKNOENT" }, \ 133 { XFS_DA_OP_CILOOKUP, "CILOOKUP" } 134 135 /* 136 * Structure to describe buffer(s) for a block. 137 * This is needed in the directory version 2 format case, when 138 * multiple non-contiguous fsblocks might be needed to cover one 139 * logical directory block. 140 * If the buffer count is 1 then the data pointer points to the 141 * same place as the b_addr field for the buffer, else to kmem_alloced memory. 142 */ 143 typedef struct xfs_dabuf { 144 int nbuf; /* number of buffer pointers present */ 145 short dirty; /* data needs to be copied back */ 146 short bbcount; /* how large is data in bbs */ 147 void *data; /* pointer for buffers' data */ 148 #ifdef XFS_DABUF_DEBUG 149 inst_t *ra; /* return address of caller to make */ 150 struct xfs_dabuf *next; /* next in global chain */ 151 struct xfs_dabuf *prev; /* previous in global chain */ 152 struct xfs_buftarg *target; /* device for buffer */ 153 xfs_daddr_t blkno; /* daddr first in bps[0] */ 154 #endif 155 struct xfs_buf *bps[1]; /* actually nbuf of these */ 156 } xfs_dabuf_t; 157 #define XFS_DA_BUF_SIZE(n) \ 158 (sizeof(xfs_dabuf_t) + sizeof(struct xfs_buf *) * ((n) - 1)) 159 160 #ifdef XFS_DABUF_DEBUG 161 extern xfs_dabuf_t *xfs_dabuf_global_list; 162 #endif 163 164 /* 165 * Storage for holding state during Btree searches and split/join ops. 166 * 167 * Only need space for 5 intermediate nodes. With a minimum of 62-way 168 * fanout to the Btree, we can support over 900 million directory blocks, 169 * which is slightly more than enough. 170 */ 171 typedef struct xfs_da_state_blk { 172 xfs_dabuf_t *bp; /* buffer containing block */ 173 xfs_dablk_t blkno; /* filesystem blkno of buffer */ 174 xfs_daddr_t disk_blkno; /* on-disk blkno (in BBs) of buffer */ 175 int index; /* relevant index into block */ 176 xfs_dahash_t hashval; /* last hash value in block */ 177 int magic; /* blk's magic number, ie: blk type */ 178 } xfs_da_state_blk_t; 179 180 typedef struct xfs_da_state_path { 181 int active; /* number of active levels */ 182 xfs_da_state_blk_t blk[XFS_DA_NODE_MAXDEPTH]; 183 } xfs_da_state_path_t; 184 185 typedef struct xfs_da_state { 186 xfs_da_args_t *args; /* filename arguments */ 187 struct xfs_mount *mp; /* filesystem mount point */ 188 unsigned int blocksize; /* logical block size */ 189 unsigned int node_ents; /* how many entries in danode */ 190 xfs_da_state_path_t path; /* search/split paths */ 191 xfs_da_state_path_t altpath; /* alternate path for join */ 192 unsigned char inleaf; /* insert into 1->lf, 0->splf */ 193 unsigned char extravalid; /* T/F: extrablk is in use */ 194 unsigned char extraafter; /* T/F: extrablk is after new */ 195 xfs_da_state_blk_t extrablk; /* for double-splits on leaves */ 196 /* for dirv2 extrablk is data */ 197 } xfs_da_state_t; 198 199 /* 200 * Utility macros to aid in logging changed structure fields. 201 */ 202 #define XFS_DA_LOGOFF(BASE, ADDR) ((char *)(ADDR) - (char *)(BASE)) 203 #define XFS_DA_LOGRANGE(BASE, ADDR, SIZE) \ 204 (uint)(XFS_DA_LOGOFF(BASE, ADDR)), \ 205 (uint)(XFS_DA_LOGOFF(BASE, ADDR)+(SIZE)-1) 206 207 /* 208 * Name ops for directory and/or attr name operations 209 */ 210 struct xfs_nameops { 211 xfs_dahash_t (*hashname)(struct xfs_name *); 212 enum xfs_dacmp (*compname)(struct xfs_da_args *, 213 const unsigned char *, int); 214 }; 215 216 217 /*======================================================================== 218 * Function prototypes. 219 *========================================================================*/ 220 221 /* 222 * Routines used for growing the Btree. 223 */ 224 int xfs_da_node_create(xfs_da_args_t *args, xfs_dablk_t blkno, int level, 225 xfs_dabuf_t **bpp, int whichfork); 226 int xfs_da_split(xfs_da_state_t *state); 227 228 /* 229 * Routines used for shrinking the Btree. 230 */ 231 int xfs_da_join(xfs_da_state_t *state); 232 void xfs_da_fixhashpath(xfs_da_state_t *state, 233 xfs_da_state_path_t *path_to_to_fix); 234 235 /* 236 * Routines used for finding things in the Btree. 237 */ 238 int xfs_da_node_lookup_int(xfs_da_state_t *state, int *result); 239 int xfs_da_path_shift(xfs_da_state_t *state, xfs_da_state_path_t *path, 240 int forward, int release, int *result); 241 /* 242 * Utility routines. 243 */ 244 int xfs_da_blk_link(xfs_da_state_t *state, xfs_da_state_blk_t *old_blk, 245 xfs_da_state_blk_t *new_blk); 246 247 /* 248 * Utility routines. 249 */ 250 int xfs_da_grow_inode(xfs_da_args_t *args, xfs_dablk_t *new_blkno); 251 int xfs_da_get_buf(struct xfs_trans *trans, struct xfs_inode *dp, 252 xfs_dablk_t bno, xfs_daddr_t mappedbno, 253 xfs_dabuf_t **bp, int whichfork); 254 int xfs_da_read_buf(struct xfs_trans *trans, struct xfs_inode *dp, 255 xfs_dablk_t bno, xfs_daddr_t mappedbno, 256 xfs_dabuf_t **bpp, int whichfork); 257 xfs_daddr_t xfs_da_reada_buf(struct xfs_trans *trans, struct xfs_inode *dp, 258 xfs_dablk_t bno, int whichfork); 259 int xfs_da_shrink_inode(xfs_da_args_t *args, xfs_dablk_t dead_blkno, 260 xfs_dabuf_t *dead_buf); 261 262 uint xfs_da_hashname(const __uint8_t *name_string, int name_length); 263 enum xfs_dacmp xfs_da_compname(struct xfs_da_args *args, 264 const unsigned char *name, int len); 265 266 267 xfs_da_state_t *xfs_da_state_alloc(void); 268 void xfs_da_state_free(xfs_da_state_t *state); 269 270 void xfs_da_buf_done(xfs_dabuf_t *dabuf); 271 void xfs_da_log_buf(struct xfs_trans *tp, xfs_dabuf_t *dabuf, uint first, 272 uint last); 273 void xfs_da_brelse(struct xfs_trans *tp, xfs_dabuf_t *dabuf); 274 void xfs_da_binval(struct xfs_trans *tp, xfs_dabuf_t *dabuf); 275 xfs_daddr_t xfs_da_blkno(xfs_dabuf_t *dabuf); 276 277 extern struct kmem_zone *xfs_da_state_zone; 278 extern struct kmem_zone *xfs_dabuf_zone; 279 extern const struct xfs_nameops xfs_default_nameops; 280 281 #endif /* __XFS_DA_BTREE_H__ */ 282