| 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 | struct xfs_buf *bps[1]; /* actually nbuf of these */ |
| 149 | } xfs_dabuf_t; |
| 150 | #define XFS_DA_BUF_SIZE(n) \ |
| 151 | (sizeof(xfs_dabuf_t) + sizeof(struct xfs_buf *) * ((n) - 1)) |
| 152 | |
| 153 | /* |
| 154 | * Storage for holding state during Btree searches and split/join ops. |
| 155 | * |
| 156 | * Only need space for 5 intermediate nodes. With a minimum of 62-way |
| 157 | * fanout to the Btree, we can support over 900 million directory blocks, |
| 158 | * which is slightly more than enough. |
| 159 | */ |
| 160 | typedef struct xfs_da_state_blk { |
| 161 | xfs_dabuf_t *bp; /* buffer containing block */ |
| 162 | xfs_dablk_t blkno; /* filesystem blkno of buffer */ |
| 163 | xfs_daddr_t disk_blkno; /* on-disk blkno (in BBs) of buffer */ |
| 164 | int index; /* relevant index into block */ |
| 165 | xfs_dahash_t hashval; /* last hash value in block */ |
| 166 | int magic; /* blk's magic number, ie: blk type */ |
| 167 | } xfs_da_state_blk_t; |
| 168 | |
| 169 | typedef struct xfs_da_state_path { |
| 170 | int active; /* number of active levels */ |
| 171 | xfs_da_state_blk_t blk[XFS_DA_NODE_MAXDEPTH]; |
| 172 | } xfs_da_state_path_t; |
| 173 | |
| 174 | typedef struct xfs_da_state { |
| 175 | xfs_da_args_t *args; /* filename arguments */ |
| 176 | struct xfs_mount *mp; /* filesystem mount point */ |
| 177 | unsigned int blocksize; /* logical block size */ |
| 178 | unsigned int node_ents; /* how many entries in danode */ |
| 179 | xfs_da_state_path_t path; /* search/split paths */ |
| 180 | xfs_da_state_path_t altpath; /* alternate path for join */ |
| 181 | unsigned char inleaf; /* insert into 1->lf, 0->splf */ |
| 182 | unsigned char extravalid; /* T/F: extrablk is in use */ |
| 183 | unsigned char extraafter; /* T/F: extrablk is after new */ |
| 184 | xfs_da_state_blk_t extrablk; /* for double-splits on leaves */ |
| 185 | /* for dirv2 extrablk is data */ |
| 186 | } xfs_da_state_t; |
| 187 | |
| 188 | /* |
| 189 | * Utility macros to aid in logging changed structure fields. |
| 190 | */ |
| 191 | #define XFS_DA_LOGOFF(BASE, ADDR) ((char *)(ADDR) - (char *)(BASE)) |
| 192 | #define XFS_DA_LOGRANGE(BASE, ADDR, SIZE) \ |
| 193 | (uint)(XFS_DA_LOGOFF(BASE, ADDR)), \ |
| 194 | (uint)(XFS_DA_LOGOFF(BASE, ADDR)+(SIZE)-1) |
| 195 | |
| 196 | /* |
| 197 | * Name ops for directory and/or attr name operations |
| 198 | */ |
| 199 | struct xfs_nameops { |
| 200 | xfs_dahash_t (*hashname)(struct xfs_name *); |
| 201 | enum xfs_dacmp (*compname)(struct xfs_da_args *, |
| 202 | const unsigned char *, int); |
| 203 | }; |
| 204 | |
| 205 | |
| 206 | /*======================================================================== |
| 207 | * Function prototypes. |
| 208 | *========================================================================*/ |
| 209 | |
| 210 | /* |
| 211 | * Routines used for growing the Btree. |
| 212 | */ |
| 213 | int xfs_da_node_create(xfs_da_args_t *args, xfs_dablk_t blkno, int level, |
| 214 | xfs_dabuf_t **bpp, int whichfork); |
| 215 | int xfs_da_split(xfs_da_state_t *state); |
| 216 | |
| 217 | /* |
| 218 | * Routines used for shrinking the Btree. |
| 219 | */ |
| 220 | int xfs_da_join(xfs_da_state_t *state); |
| 221 | void xfs_da_fixhashpath(xfs_da_state_t *state, |
| 222 | xfs_da_state_path_t *path_to_to_fix); |
| 223 | |
| 224 | /* |
| 225 | * Routines used for finding things in the Btree. |
| 226 | */ |
| 227 | int xfs_da_node_lookup_int(xfs_da_state_t *state, int *result); |
| 228 | int xfs_da_path_shift(xfs_da_state_t *state, xfs_da_state_path_t *path, |
| 229 | int forward, int release, int *result); |
| 230 | /* |
| 231 | * Utility routines. |
| 232 | */ |
| 233 | int xfs_da_blk_link(xfs_da_state_t *state, xfs_da_state_blk_t *old_blk, |
| 234 | xfs_da_state_blk_t *new_blk); |
| 235 | |
| 236 | /* |
| 237 | * Utility routines. |
| 238 | */ |
| 239 | int xfs_da_grow_inode(xfs_da_args_t *args, xfs_dablk_t *new_blkno); |
| 240 | int xfs_da_grow_inode_int(struct xfs_da_args *args, xfs_fileoff_t *bno, |
| 241 | int count); |
| 242 | int xfs_da_get_buf(struct xfs_trans *trans, struct xfs_inode *dp, |
| 243 | xfs_dablk_t bno, xfs_daddr_t mappedbno, |
| 244 | xfs_dabuf_t **bp, int whichfork); |
| 245 | int xfs_da_read_buf(struct xfs_trans *trans, struct xfs_inode *dp, |
| 246 | xfs_dablk_t bno, xfs_daddr_t mappedbno, |
| 247 | xfs_dabuf_t **bpp, int whichfork); |
| 248 | xfs_daddr_t xfs_da_reada_buf(struct xfs_trans *trans, struct xfs_inode *dp, |
| 249 | xfs_dablk_t bno, int whichfork); |
| 250 | int xfs_da_shrink_inode(xfs_da_args_t *args, xfs_dablk_t dead_blkno, |
| 251 | xfs_dabuf_t *dead_buf); |
| 252 | |
| 253 | uint xfs_da_hashname(const __uint8_t *name_string, int name_length); |
| 254 | enum xfs_dacmp xfs_da_compname(struct xfs_da_args *args, |
| 255 | const unsigned char *name, int len); |
| 256 | |
| 257 | |
| 258 | xfs_da_state_t *xfs_da_state_alloc(void); |
| 259 | void xfs_da_state_free(xfs_da_state_t *state); |
| 260 | |
| 261 | void xfs_da_buf_done(xfs_dabuf_t *dabuf); |
| 262 | void xfs_da_log_buf(struct xfs_trans *tp, xfs_dabuf_t *dabuf, uint first, |
| 263 | uint last); |
| 264 | void xfs_da_brelse(struct xfs_trans *tp, xfs_dabuf_t *dabuf); |
| 265 | void xfs_da_binval(struct xfs_trans *tp, xfs_dabuf_t *dabuf); |
| 266 | xfs_daddr_t xfs_da_blkno(xfs_dabuf_t *dabuf); |
| 267 | |
| 268 | extern struct kmem_zone *xfs_da_state_zone; |
| 269 | extern struct kmem_zone *xfs_dabuf_zone; |
| 270 | extern const struct xfs_nameops xfs_default_nameops; |
| 271 | |
| 272 | #endif /* __XFS_DA_BTREE_H__ */ |