1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (c) 2000,2002,2005 Silicon Graphics, Inc. 4 * Copyright (c) 2013 Red Hat, Inc. 5 * All Rights Reserved. 6 */ 7 #ifndef __XFS_DA_BTREE_H__ 8 #define __XFS_DA_BTREE_H__ 9 10 struct xfs_inode; 11 struct xfs_trans; 12 struct zone; 13 14 /* 15 * Directory/attribute geometry information. There will be one of these for each 16 * data fork type, and it will be passed around via the xfs_da_args. Global 17 * structures will be attached to the xfs_mount. 18 */ 19 struct xfs_da_geometry { 20 unsigned int blksize; /* da block size in bytes */ 21 unsigned int fsbcount; /* da block size in filesystem blocks */ 22 uint8_t fsblog; /* log2 of _filesystem_ block size */ 23 uint8_t blklog; /* log2 of da block size */ 24 unsigned int node_hdr_size; /* danode header size in bytes */ 25 unsigned int node_ents; /* # of entries in a danode */ 26 unsigned int magicpct; /* 37% of block size in bytes */ 27 xfs_dablk_t datablk; /* blockno of dir data v2 */ 28 unsigned int leaf_hdr_size; /* dir2 leaf header size */ 29 unsigned int leaf_max_ents; /* # of entries in dir2 leaf */ 30 xfs_dablk_t leafblk; /* blockno of leaf data v2 */ 31 unsigned int free_hdr_size; /* dir2 free header size */ 32 unsigned int free_max_bests; /* # of bests entries in dir2 free */ 33 xfs_dablk_t freeblk; /* blockno of free data v2 */ 34 35 xfs_dir2_data_aoff_t data_first_offset; 36 size_t data_entry_offset; 37 }; 38 39 /*======================================================================== 40 * Btree searching and modification structure definitions. 41 *========================================================================*/ 42 43 /* 44 * Search comparison results 45 */ 46 enum xfs_dacmp { 47 XFS_CMP_DIFFERENT, /* names are completely different */ 48 XFS_CMP_EXACT, /* names are exactly the same */ 49 XFS_CMP_CASE /* names are same but differ in case */ 50 }; 51 52 /* 53 * Structure to ease passing around component names. 54 */ 55 typedef struct xfs_da_args { 56 struct xfs_da_geometry *geo; /* da block geometry */ 57 const uint8_t *name; /* string (maybe not NULL terminated) */ 58 int namelen; /* length of string (maybe no NULL) */ 59 uint8_t filetype; /* filetype of inode for directories */ 60 uint8_t *value; /* set of bytes (maybe contain NULLs) */ 61 int valuelen; /* length of value */ 62 int flags; /* argument flags (eg: ATTR_NOCREATE) */ 63 xfs_dahash_t hashval; /* hash value of name */ 64 xfs_ino_t inumber; /* input/output inode number */ 65 struct xfs_inode *dp; /* directory inode to manipulate */ 66 struct xfs_trans *trans; /* current trans (changes over time) */ 67 xfs_extlen_t total; /* total blocks needed, for 1st bmap */ 68 int whichfork; /* data or attribute fork */ 69 xfs_dablk_t blkno; /* blkno of attr leaf of interest */ 70 int index; /* index of attr of interest in blk */ 71 xfs_dablk_t rmtblkno; /* remote attr value starting blkno */ 72 int rmtblkcnt; /* remote attr value block count */ 73 int rmtvaluelen; /* remote attr value length in bytes */ 74 xfs_dablk_t blkno2; /* blkno of 2nd attr leaf of interest */ 75 int index2; /* index of 2nd attr in blk */ 76 xfs_dablk_t rmtblkno2; /* remote attr value starting blkno */ 77 int rmtblkcnt2; /* remote attr value block count */ 78 int rmtvaluelen2; /* remote attr value length in bytes */ 79 int op_flags; /* operation flags */ 80 enum xfs_dacmp cmpresult; /* name compare result for lookups */ 81 } xfs_da_args_t; 82 83 /* 84 * Operation flags: 85 */ 86 #define XFS_DA_OP_JUSTCHECK 0x0001 /* check for ok with no space */ 87 #define XFS_DA_OP_RENAME 0x0002 /* this is an atomic rename op */ 88 #define XFS_DA_OP_ADDNAME 0x0004 /* this is an add operation */ 89 #define XFS_DA_OP_OKNOENT 0x0008 /* lookup/add op, ENOENT ok, else die */ 90 #define XFS_DA_OP_CILOOKUP 0x0010 /* lookup to return CI name if found */ 91 #define XFS_DA_OP_ALLOCVAL 0x0020 /* lookup to alloc buffer if found */ 92 #define XFS_DA_OP_INCOMPLETE 0x0040 /* lookup INCOMPLETE attr keys */ 93 94 #define XFS_DA_OP_FLAGS \ 95 { XFS_DA_OP_JUSTCHECK, "JUSTCHECK" }, \ 96 { XFS_DA_OP_RENAME, "RENAME" }, \ 97 { XFS_DA_OP_ADDNAME, "ADDNAME" }, \ 98 { XFS_DA_OP_OKNOENT, "OKNOENT" }, \ 99 { XFS_DA_OP_CILOOKUP, "CILOOKUP" }, \ 100 { XFS_DA_OP_ALLOCVAL, "ALLOCVAL" }, \ 101 { XFS_DA_OP_INCOMPLETE, "INCOMPLETE" } 102 103 /* 104 * Storage for holding state during Btree searches and split/join ops. 105 * 106 * Only need space for 5 intermediate nodes. With a minimum of 62-way 107 * fanout to the Btree, we can support over 900 million directory blocks, 108 * which is slightly more than enough. 109 */ 110 typedef struct xfs_da_state_blk { 111 struct xfs_buf *bp; /* buffer containing block */ 112 xfs_dablk_t blkno; /* filesystem blkno of buffer */ 113 xfs_daddr_t disk_blkno; /* on-disk blkno (in BBs) of buffer */ 114 int index; /* relevant index into block */ 115 xfs_dahash_t hashval; /* last hash value in block */ 116 int magic; /* blk's magic number, ie: blk type */ 117 } xfs_da_state_blk_t; 118 119 typedef struct xfs_da_state_path { 120 int active; /* number of active levels */ 121 xfs_da_state_blk_t blk[XFS_DA_NODE_MAXDEPTH]; 122 } xfs_da_state_path_t; 123 124 typedef struct xfs_da_state { 125 xfs_da_args_t *args; /* filename arguments */ 126 struct xfs_mount *mp; /* filesystem mount point */ 127 xfs_da_state_path_t path; /* search/split paths */ 128 xfs_da_state_path_t altpath; /* alternate path for join */ 129 unsigned char inleaf; /* insert into 1->lf, 0->splf */ 130 unsigned char extravalid; /* T/F: extrablk is in use */ 131 unsigned char extraafter; /* T/F: extrablk is after new */ 132 xfs_da_state_blk_t extrablk; /* for double-splits on leaves */ 133 /* for dirv2 extrablk is data */ 134 } xfs_da_state_t; 135 136 /* 137 * In-core version of the node header to abstract the differences in the v2 and 138 * v3 disk format of the headers. Callers need to convert to/from disk format as 139 * appropriate. 140 */ 141 struct xfs_da3_icnode_hdr { 142 uint32_t forw; 143 uint32_t back; 144 uint16_t magic; 145 uint16_t count; 146 uint16_t level; 147 148 /* 149 * Pointer to the on-disk format entries, which are behind the 150 * variable size (v4 vs v5) header in the on-disk block. 151 */ 152 struct xfs_da_node_entry *btree; 153 }; 154 155 /* 156 * Utility macros to aid in logging changed structure fields. 157 */ 158 #define XFS_DA_LOGOFF(BASE, ADDR) ((char *)(ADDR) - (char *)(BASE)) 159 #define XFS_DA_LOGRANGE(BASE, ADDR, SIZE) \ 160 (uint)(XFS_DA_LOGOFF(BASE, ADDR)), \ 161 (uint)(XFS_DA_LOGOFF(BASE, ADDR)+(SIZE)-1) 162 163 /*======================================================================== 164 * Function prototypes. 165 *========================================================================*/ 166 167 /* 168 * Routines used for growing the Btree. 169 */ 170 int xfs_da3_node_create(struct xfs_da_args *args, xfs_dablk_t blkno, 171 int level, struct xfs_buf **bpp, int whichfork); 172 int xfs_da3_split(xfs_da_state_t *state); 173 174 /* 175 * Routines used for shrinking the Btree. 176 */ 177 int xfs_da3_join(xfs_da_state_t *state); 178 void xfs_da3_fixhashpath(struct xfs_da_state *state, 179 struct xfs_da_state_path *path_to_to_fix); 180 181 /* 182 * Routines used for finding things in the Btree. 183 */ 184 int xfs_da3_node_lookup_int(xfs_da_state_t *state, int *result); 185 int xfs_da3_path_shift(xfs_da_state_t *state, xfs_da_state_path_t *path, 186 int forward, int release, int *result); 187 /* 188 * Utility routines. 189 */ 190 int xfs_da3_blk_link(xfs_da_state_t *state, xfs_da_state_blk_t *old_blk, 191 xfs_da_state_blk_t *new_blk); 192 int xfs_da3_node_read(struct xfs_trans *tp, struct xfs_inode *dp, 193 xfs_dablk_t bno, struct xfs_buf **bpp, int whichfork); 194 int xfs_da3_node_read_mapped(struct xfs_trans *tp, struct xfs_inode *dp, 195 xfs_daddr_t mappedbno, struct xfs_buf **bpp, 196 int whichfork); 197 198 /* 199 * Utility routines. 200 */ 201 202 #define XFS_DABUF_MAP_HOLE_OK (1 << 0) 203 204 int xfs_da_grow_inode(xfs_da_args_t *args, xfs_dablk_t *new_blkno); 205 int xfs_da_grow_inode_int(struct xfs_da_args *args, xfs_fileoff_t *bno, 206 int count); 207 int xfs_da_get_buf(struct xfs_trans *trans, struct xfs_inode *dp, 208 xfs_dablk_t bno, struct xfs_buf **bp, int whichfork); 209 int xfs_da_read_buf(struct xfs_trans *trans, struct xfs_inode *dp, 210 xfs_dablk_t bno, unsigned int flags, struct xfs_buf **bpp, 211 int whichfork, const struct xfs_buf_ops *ops); 212 int xfs_da_reada_buf(struct xfs_inode *dp, xfs_dablk_t bno, 213 unsigned int flags, int whichfork, 214 const struct xfs_buf_ops *ops); 215 int xfs_da_shrink_inode(xfs_da_args_t *args, xfs_dablk_t dead_blkno, 216 struct xfs_buf *dead_buf); 217 218 uint xfs_da_hashname(const uint8_t *name_string, int name_length); 219 enum xfs_dacmp xfs_da_compname(struct xfs_da_args *args, 220 const unsigned char *name, int len); 221 222 223 xfs_da_state_t *xfs_da_state_alloc(void); 224 void xfs_da_state_free(xfs_da_state_t *state); 225 226 void xfs_da3_node_hdr_from_disk(struct xfs_mount *mp, 227 struct xfs_da3_icnode_hdr *to, struct xfs_da_intnode *from); 228 void xfs_da3_node_hdr_to_disk(struct xfs_mount *mp, 229 struct xfs_da_intnode *to, struct xfs_da3_icnode_hdr *from); 230 231 extern struct kmem_zone *xfs_da_state_zone; 232 233 #endif /* __XFS_DA_BTREE_H__ */ 234