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_DIR_LEAF_MAGIC 0xfeeb /* magic number: directory leaf blks */ 40 #define XFS_ATTR_LEAF_MAGIC 0xfbee /* magic number: attribute leaf blks */ 41 #define XFS_DIR2_LEAF1_MAGIC 0xd2f1 /* magic number: v2 dirlf single blks */ 42 #define XFS_DIR2_LEAFN_MAGIC 0xd2ff /* magic number: v2 dirlf multi blks */ 43 44 #define XFS_DIRX_LEAF_MAGIC(mp) \ 45 (XFS_DIR_IS_V1(mp) ? XFS_DIR_LEAF_MAGIC : XFS_DIR2_LEAFN_MAGIC) 46 47 typedef struct xfs_da_blkinfo { 48 __be32 forw; /* previous block in list */ 49 __be32 back; /* following block in list */ 50 __be16 magic; /* validity check on block */ 51 __be16 pad; /* unused */ 52 } xfs_da_blkinfo_t; 53 54 /* 55 * This is the structure of the root and intermediate nodes in the Btree. 56 * The leaf nodes are defined above. 57 * 58 * Entries are not packed. 59 * 60 * Since we have duplicate keys, use a binary search but always follow 61 * all match in the block, not just the first match found. 62 */ 63 #define XFS_DA_NODE_MAXDEPTH 5 /* max depth of Btree */ 64 65 typedef struct xfs_da_intnode { 66 struct xfs_da_node_hdr { /* constant-structure header block */ 67 xfs_da_blkinfo_t info; /* block type, links, etc. */ 68 __be16 count; /* count of active entries */ 69 __be16 level; /* level above leaves (leaf == 0) */ 70 } hdr; 71 struct xfs_da_node_entry { 72 __be32 hashval; /* hash value for this descendant */ 73 __be32 before; /* Btree block before this key */ 74 } btree[1]; /* variable sized array of keys */ 75 } xfs_da_intnode_t; 76 typedef struct xfs_da_node_hdr xfs_da_node_hdr_t; 77 typedef struct xfs_da_node_entry xfs_da_node_entry_t; 78 79 #define XFS_DA_MAXHASH ((xfs_dahash_t)-1) /* largest valid hash value */ 80 81 #define XFS_LBSIZE(mp) (mp)->m_sb.sb_blocksize 82 #define XFS_LBLOG(mp) (mp)->m_sb.sb_blocklog 83 84 #define XFS_DA_MAKE_BNOENTRY(mp,bno,entry) \ 85 (((bno) << (mp)->m_dircook_elog) | (entry)) 86 #define XFS_DA_MAKE_COOKIE(mp,bno,entry,hash) \ 87 (((xfs_off_t)XFS_DA_MAKE_BNOENTRY(mp, bno, entry) << 32) | (hash)) 88 #define XFS_DA_COOKIE_HASH(mp,cookie) ((xfs_dahash_t)cookie) 89 #define XFS_DA_COOKIE_BNO(mp,cookie) \ 90 ((((xfs_off_t)(cookie) >> 31) == -1LL ? \ 91 (xfs_dablk_t)0 : \ 92 (xfs_dablk_t)((xfs_off_t)(cookie) >> \ 93 ((mp)->m_dircook_elog + 32)))) 94 #define XFS_DA_COOKIE_ENTRY(mp,cookie) \ 95 ((((xfs_off_t)(cookie) >> 31) == -1LL ? \ 96 (xfs_dablk_t)0 : \ 97 (xfs_dablk_t)(((xfs_off_t)(cookie) >> 32) & \ 98 ((1 << (mp)->m_dircook_elog) - 1)))) 99 100 101 /*======================================================================== 102 * Btree searching and modification structure definitions. 103 *========================================================================*/ 104 105 /* 106 * Structure to ease passing around component names. 107 */ 108 typedef struct xfs_da_args { 109 const uchar_t *name; /* string (maybe not NULL terminated) */ 110 int namelen; /* length of string (maybe no NULL) */ 111 uchar_t *value; /* set of bytes (maybe contain NULLs) */ 112 int valuelen; /* length of value */ 113 int flags; /* argument flags (eg: ATTR_NOCREATE) */ 114 xfs_dahash_t hashval; /* hash value of name */ 115 xfs_ino_t inumber; /* input/output inode number */ 116 struct xfs_inode *dp; /* directory inode to manipulate */ 117 xfs_fsblock_t *firstblock; /* ptr to firstblock for bmap calls */ 118 struct xfs_bmap_free *flist; /* ptr to freelist for bmap_finish */ 119 struct xfs_trans *trans; /* current trans (changes over time) */ 120 xfs_extlen_t total; /* total blocks needed, for 1st bmap */ 121 int whichfork; /* data or attribute fork */ 122 xfs_dablk_t blkno; /* blkno of attr leaf of interest */ 123 int index; /* index of attr of interest in blk */ 124 xfs_dablk_t rmtblkno; /* remote attr value starting blkno */ 125 int rmtblkcnt; /* remote attr value block count */ 126 xfs_dablk_t blkno2; /* blkno of 2nd attr leaf of interest */ 127 int index2; /* index of 2nd attr in blk */ 128 xfs_dablk_t rmtblkno2; /* remote attr value starting blkno */ 129 int rmtblkcnt2; /* remote attr value block count */ 130 unsigned char justcheck; /* T/F: check for ok with no space */ 131 unsigned char rename; /* T/F: this is an atomic rename op */ 132 unsigned char addname; /* T/F: this is an add operation */ 133 unsigned char oknoent; /* T/F: ok to return ENOENT, else die */ 134 } xfs_da_args_t; 135 136 /* 137 * Structure to describe buffer(s) for a block. 138 * This is needed in the directory version 2 format case, when 139 * multiple non-contiguous fsblocks might be needed to cover one 140 * logical directory block. 141 * If the buffer count is 1 then the data pointer points to the 142 * same place as the b_addr field for the buffer, else to kmem_alloced memory. 143 */ 144 typedef struct xfs_dabuf { 145 int nbuf; /* number of buffer pointers present */ 146 short dirty; /* data needs to be copied back */ 147 short bbcount; /* how large is data in bbs */ 148 void *data; /* pointer for buffers' data */ 149 #ifdef XFS_DABUF_DEBUG 150 inst_t *ra; /* return address of caller to make */ 151 struct xfs_dabuf *next; /* next in global chain */ 152 struct xfs_dabuf *prev; /* previous in global chain */ 153 struct xfs_buftarg *target; /* device for buffer */ 154 xfs_daddr_t blkno; /* daddr first in bps[0] */ 155 #endif 156 struct xfs_buf *bps[1]; /* actually nbuf of these */ 157 } xfs_dabuf_t; 158 #define XFS_DA_BUF_SIZE(n) \ 159 (sizeof(xfs_dabuf_t) + sizeof(struct xfs_buf *) * ((n) - 1)) 160 161 #ifdef XFS_DABUF_DEBUG 162 extern xfs_dabuf_t *xfs_dabuf_global_list; 163 #endif 164 165 /* 166 * Storage for holding state during Btree searches and split/join ops. 167 * 168 * Only need space for 5 intermediate nodes. With a minimum of 62-way 169 * fanout to the Btree, we can support over 900 million directory blocks, 170 * which is slightly more than enough. 171 */ 172 typedef struct xfs_da_state_blk { 173 xfs_dabuf_t *bp; /* buffer containing block */ 174 xfs_dablk_t blkno; /* filesystem blkno of buffer */ 175 xfs_daddr_t disk_blkno; /* on-disk blkno (in BBs) of buffer */ 176 int index; /* relevant index into block */ 177 xfs_dahash_t hashval; /* last hash value in block */ 178 int magic; /* blk's magic number, ie: blk type */ 179 } xfs_da_state_blk_t; 180 181 typedef struct xfs_da_state_path { 182 int active; /* number of active levels */ 183 xfs_da_state_blk_t blk[XFS_DA_NODE_MAXDEPTH]; 184 } xfs_da_state_path_t; 185 186 typedef struct xfs_da_state { 187 xfs_da_args_t *args; /* filename arguments */ 188 struct xfs_mount *mp; /* filesystem mount point */ 189 unsigned int blocksize; /* logical block size */ 190 unsigned int node_ents; /* how many entries in danode */ 191 xfs_da_state_path_t path; /* search/split paths */ 192 xfs_da_state_path_t altpath; /* alternate path for join */ 193 unsigned char inleaf; /* insert into 1->lf, 0->splf */ 194 unsigned char extravalid; /* T/F: extrablk is in use */ 195 unsigned char extraafter; /* T/F: extrablk is after new */ 196 xfs_da_state_blk_t extrablk; /* for double-splits on leafs */ 197 /* for dirv2 extrablk is data */ 198 } xfs_da_state_t; 199 200 /* 201 * Utility macros to aid in logging changed structure fields. 202 */ 203 #define XFS_DA_LOGOFF(BASE, ADDR) ((char *)(ADDR) - (char *)(BASE)) 204 #define XFS_DA_LOGRANGE(BASE, ADDR, SIZE) \ 205 (uint)(XFS_DA_LOGOFF(BASE, ADDR)), \ 206 (uint)(XFS_DA_LOGOFF(BASE, ADDR)+(SIZE)-1) 207 208 209 #ifdef __KERNEL__ 210 /*======================================================================== 211 * Function prototypes for the kernel. 212 *========================================================================*/ 213 214 /* 215 * Routines used for growing the Btree. 216 */ 217 int xfs_da_node_create(xfs_da_args_t *args, xfs_dablk_t blkno, int level, 218 xfs_dabuf_t **bpp, int whichfork); 219 int xfs_da_split(xfs_da_state_t *state); 220 221 /* 222 * Routines used for shrinking the Btree. 223 */ 224 int xfs_da_join(xfs_da_state_t *state); 225 void xfs_da_fixhashpath(xfs_da_state_t *state, 226 xfs_da_state_path_t *path_to_to_fix); 227 228 /* 229 * Routines used for finding things in the Btree. 230 */ 231 int xfs_da_node_lookup_int(xfs_da_state_t *state, int *result); 232 int xfs_da_path_shift(xfs_da_state_t *state, xfs_da_state_path_t *path, 233 int forward, int release, int *result); 234 /* 235 * Utility routines. 236 */ 237 int xfs_da_blk_link(xfs_da_state_t *state, xfs_da_state_blk_t *old_blk, 238 xfs_da_state_blk_t *new_blk); 239 240 /* 241 * Utility routines. 242 */ 243 int xfs_da_grow_inode(xfs_da_args_t *args, xfs_dablk_t *new_blkno); 244 int xfs_da_get_buf(struct xfs_trans *trans, struct xfs_inode *dp, 245 xfs_dablk_t bno, xfs_daddr_t mappedbno, 246 xfs_dabuf_t **bp, int whichfork); 247 int xfs_da_read_buf(struct xfs_trans *trans, struct xfs_inode *dp, 248 xfs_dablk_t bno, xfs_daddr_t mappedbno, 249 xfs_dabuf_t **bpp, int whichfork); 250 xfs_daddr_t xfs_da_reada_buf(struct xfs_trans *trans, struct xfs_inode *dp, 251 xfs_dablk_t bno, int whichfork); 252 int xfs_da_shrink_inode(xfs_da_args_t *args, xfs_dablk_t dead_blkno, 253 xfs_dabuf_t *dead_buf); 254 255 uint xfs_da_hashname(const uchar_t *name_string, int name_length); 256 uint xfs_da_log2_roundup(uint i); 257 xfs_da_state_t *xfs_da_state_alloc(void); 258 void xfs_da_state_free(xfs_da_state_t *state); 259 260 void xfs_da_buf_done(xfs_dabuf_t *dabuf); 261 void xfs_da_log_buf(struct xfs_trans *tp, xfs_dabuf_t *dabuf, uint first, 262 uint last); 263 void xfs_da_brelse(struct xfs_trans *tp, xfs_dabuf_t *dabuf); 264 void xfs_da_binval(struct xfs_trans *tp, xfs_dabuf_t *dabuf); 265 xfs_daddr_t xfs_da_blkno(xfs_dabuf_t *dabuf); 266 267 extern struct kmem_zone *xfs_da_state_zone; 268 #endif /* __KERNEL__ */ 269 270 #endif /* __XFS_DA_BTREE_H__ */ 271