1153323Srodrigc/* 2159451Srodrigc * Copyright (c) 2000-2001,2005 Silicon Graphics, Inc. 3159451Srodrigc * All Rights Reserved. 4153323Srodrigc * 5159451Srodrigc * This program is free software; you can redistribute it and/or 6159451Srodrigc * modify it under the terms of the GNU General Public License as 7153323Srodrigc * published by the Free Software Foundation. 8153323Srodrigc * 9159451Srodrigc * This program is distributed in the hope that it would be useful, 10159451Srodrigc * but WITHOUT ANY WARRANTY; without even the implied warranty of 11159451Srodrigc * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12159451Srodrigc * GNU General Public License for more details. 13153323Srodrigc * 14159451Srodrigc * You should have received a copy of the GNU General Public License 15159451Srodrigc * along with this program; if not, write the Free Software Foundation, 16159451Srodrigc * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA 17153323Srodrigc */ 18153323Srodrigc#ifndef __XFS_DIR_LEAF_H__ 19153323Srodrigc#define __XFS_DIR_LEAF_H__ 20153323Srodrigc 21153323Srodrigc/* 22153323Srodrigc * Directory layout, internal structure, access macros, etc. 23153323Srodrigc * 24153323Srodrigc * Large directories are structured around Btrees where all the data 25153323Srodrigc * elements are in the leaf nodes. Filenames are hashed into an int, 26153323Srodrigc * then that int is used as the index into the Btree. Since the hashval 27153323Srodrigc * of a filename may not be unique, we may have duplicate keys. The 28153323Srodrigc * internal links in the Btree are logical block offsets into the file. 29153323Srodrigc */ 30153323Srodrigc 31153323Srodrigcstruct uio; 32153323Srodrigcstruct xfs_bmap_free; 33153323Srodrigcstruct xfs_dabuf; 34153323Srodrigcstruct xfs_da_args; 35153323Srodrigcstruct xfs_da_state; 36153323Srodrigcstruct xfs_da_state_blk; 37153323Srodrigcstruct xfs_dir_put_args; 38153323Srodrigcstruct xfs_inode; 39153323Srodrigcstruct xfs_mount; 40153323Srodrigcstruct xfs_trans; 41153323Srodrigc 42153323Srodrigc/*======================================================================== 43153323Srodrigc * Directory Structure when equal to XFS_LBSIZE(mp) bytes. 44153323Srodrigc *========================================================================*/ 45153323Srodrigc 46153323Srodrigc/* 47153323Srodrigc * This is the structure of the leaf nodes in the Btree. 48153323Srodrigc * 49153323Srodrigc * Struct leaf_entry's are packed from the top. Names grow from the bottom 50153323Srodrigc * but are not packed. The freemap contains run-length-encoded entries 51153323Srodrigc * for the free bytes after the leaf_entry's, but only the N largest such, 52153323Srodrigc * smaller runs are dropped. When the freemap doesn't show enough space 53153323Srodrigc * for an allocation, we compact the namelist area and try again. If we 54153323Srodrigc * still don't have enough space, then we have to split the block. 55153323Srodrigc * 56153323Srodrigc * Since we have duplicate hash keys, for each key that matches, compare 57153323Srodrigc * the actual string. The root and intermediate node search always takes 58153323Srodrigc * the first-in-the-block key match found, so we should only have to work 59153323Srodrigc * "forw"ard. If none matches, continue with the "forw"ard leaf nodes 60153323Srodrigc * until the hash key changes or the filename is found. 61153323Srodrigc * 62153323Srodrigc * The parent directory and the self-pointer are explicitly represented 63153323Srodrigc * (ie: there are entries for "." and ".."). 64153323Srodrigc * 65153323Srodrigc * Note that the count being a __uint16_t limits us to something like a 66153323Srodrigc * blocksize of 1.3MB in the face of worst case (short) filenames. 67153323Srodrigc */ 68153323Srodrigc#define XFS_DIR_LEAF_MAPSIZE 3 /* how many freespace slots */ 69153323Srodrigc 70159451Srodrigctypedef struct xfs_dir_leaf_map { /* RLE map of free bytes */ 71159451Srodrigc __uint16_t base; /* base of free region */ 72159451Srodrigc __uint16_t size; /* run length of free region */ 73159451Srodrigc} xfs_dir_leaf_map_t; 74159451Srodrigc 75159451Srodrigctypedef struct xfs_dir_leaf_hdr { /* constant-structure header block */ 76159451Srodrigc xfs_da_blkinfo_t info; /* block type, links, etc. */ 77159451Srodrigc __uint16_t count; /* count of active leaf_entry's */ 78159451Srodrigc __uint16_t namebytes; /* num bytes of name strings stored */ 79159451Srodrigc __uint16_t firstused; /* first used byte in name area */ 80159451Srodrigc __uint8_t holes; /* != 0 if blk needs compaction */ 81159451Srodrigc __uint8_t pad1; 82159451Srodrigc xfs_dir_leaf_map_t freemap[XFS_DIR_LEAF_MAPSIZE]; 83159451Srodrigc} xfs_dir_leaf_hdr_t; 84159451Srodrigc 85159451Srodrigctypedef struct xfs_dir_leaf_entry { /* sorted on key, not name */ 86159451Srodrigc xfs_dahash_t hashval; /* hash value of name */ 87159451Srodrigc __uint16_t nameidx; /* index into buffer of name */ 88159451Srodrigc __uint8_t namelen; /* length of name string */ 89159451Srodrigc __uint8_t pad2; 90159451Srodrigc} xfs_dir_leaf_entry_t; 91159451Srodrigc 92159451Srodrigctypedef struct xfs_dir_leaf_name { 93159451Srodrigc xfs_dir_ino_t inumber; /* inode number for this key */ 94159451Srodrigc __uint8_t name[1]; /* name string itself */ 95159451Srodrigc} xfs_dir_leaf_name_t; 96159451Srodrigc 97153323Srodrigctypedef struct xfs_dir_leafblock { 98159451Srodrigc xfs_dir_leaf_hdr_t hdr; /* constant-structure header block */ 99159451Srodrigc xfs_dir_leaf_entry_t entries[1]; /* var sized array */ 100159451Srodrigc xfs_dir_leaf_name_t namelist[1]; /* grows from bottom of buf */ 101153323Srodrigc} xfs_dir_leafblock_t; 102153323Srodrigc 103153323Srodrigc/* 104153323Srodrigc * Length of name for which a 512-byte block filesystem 105153323Srodrigc * can get a double split. 106153323Srodrigc */ 107153323Srodrigc#define XFS_DIR_LEAF_CAN_DOUBLE_SPLIT_LEN \ 108153323Srodrigc (512 - (uint)sizeof(xfs_dir_leaf_hdr_t) - \ 109153323Srodrigc (uint)sizeof(xfs_dir_leaf_entry_t) * 2 - \ 110153323Srodrigc (uint)sizeof(xfs_dir_leaf_name_t) * 2 - (MAXNAMELEN - 2) + 1 + 1) 111153323Srodrigc 112153323Srodrigctypedef int (*xfs_dir_put_t)(struct xfs_dir_put_args *pa); 113153323Srodrigc 114153323Srodrigctypedef union { 115153323Srodrigc xfs_off_t o; /* offset (cookie) */ 116153323Srodrigc /* 117153323Srodrigc * Watch the order here (endian-ness dependent). 118153323Srodrigc */ 119153323Srodrigc struct { 120159451Srodrigc#ifndef XFS_NATIVE_HOST 121153323Srodrigc xfs_dahash_t h; /* hash value */ 122153323Srodrigc __uint32_t be; /* block and entry */ 123159451Srodrigc#else 124153323Srodrigc __uint32_t be; /* block and entry */ 125153323Srodrigc xfs_dahash_t h; /* hash value */ 126159451Srodrigc#endif /* XFS_NATIVE_HOST */ 127153323Srodrigc } s; 128153323Srodrigc} xfs_dircook_t; 129153323Srodrigc 130153323Srodrigc#define XFS_PUT_COOKIE(c,mp,bno,entry,hash) \ 131153323Srodrigc ((c).s.be = XFS_DA_MAKE_BNOENTRY(mp, bno, entry), (c).s.h = (hash)) 132153323Srodrigc 133159451Srodrigctypedef struct xfs_dir_put_args { 134153323Srodrigc xfs_dircook_t cook; /* cookie of (next) entry */ 135153323Srodrigc xfs_intino_t ino; /* inode number */ 136159451Srodrigc struct xfs_dirent *dbp; /* buffer pointer */ 137153323Srodrigc char *name; /* directory entry name */ 138153323Srodrigc int namelen; /* length of name */ 139153323Srodrigc int done; /* output: set if value was stored */ 140153323Srodrigc xfs_dir_put_t put; /* put function ptr (i/o) */ 141153323Srodrigc struct uio *uio; /* uio control structure */ 142153323Srodrigc} xfs_dir_put_args_t; 143153323Srodrigc 144159451Srodrigc#define XFS_DIR_LEAF_ENTSIZE_BYNAME(len) \ 145159451Srodrigc xfs_dir_leaf_entsize_byname(len) 146159451Srodrigcstatic inline int xfs_dir_leaf_entsize_byname(int len) 147159451Srodrigc{ 148159451Srodrigc return (uint)sizeof(xfs_dir_leaf_name_t)-1 + len; 149159451Srodrigc} 150153323Srodrigc 151153323Srodrigc#define XFS_DIR_LEAF_ENTSIZE_BYENTRY(entry) \ 152153323Srodrigc xfs_dir_leaf_entsize_byentry(entry) 153159451Srodrigcstatic inline int xfs_dir_leaf_entsize_byentry(xfs_dir_leaf_entry_t *entry) 154159451Srodrigc{ 155159451Srodrigc return (uint)sizeof(xfs_dir_leaf_name_t)-1 + (entry)->namelen; 156159451Srodrigc} 157153323Srodrigc 158153323Srodrigc#define XFS_DIR_LEAF_NAMESTRUCT(leafp,offset) \ 159153323Srodrigc xfs_dir_leaf_namestruct(leafp,offset) 160159451Srodrigcstatic inline xfs_dir_leaf_name_t * 161159451Srodrigcxfs_dir_leaf_namestruct(xfs_dir_leafblock_t *leafp, int offset) 162159451Srodrigc{ 163159451Srodrigc return (xfs_dir_leaf_name_t *)&((char *)(leafp))[offset]; 164159451Srodrigc} 165153323Srodrigc 166153323Srodrigc/*======================================================================== 167153323Srodrigc * Function prototypes for the kernel. 168153323Srodrigc *========================================================================*/ 169153323Srodrigc 170153323Srodrigc/* 171153323Srodrigc * Internal routines when dirsize < XFS_LITINO(mp). 172153323Srodrigc */ 173153323Srodrigcint xfs_dir_shortform_create(struct xfs_da_args *args, xfs_ino_t parent); 174153323Srodrigcint xfs_dir_shortform_addname(struct xfs_da_args *args); 175153323Srodrigcint xfs_dir_shortform_lookup(struct xfs_da_args *args); 176153323Srodrigcint xfs_dir_shortform_to_leaf(struct xfs_da_args *args); 177153323Srodrigcint xfs_dir_shortform_removename(struct xfs_da_args *args); 178153323Srodrigcint xfs_dir_shortform_getdents(struct xfs_inode *dp, struct uio *uio, int *eofp, 179159451Srodrigc struct xfs_dirent *dbp, xfs_dir_put_t put); 180153323Srodrigcint xfs_dir_shortform_replace(struct xfs_da_args *args); 181153323Srodrigc 182153323Srodrigc/* 183153323Srodrigc * Internal routines when dirsize == XFS_LBSIZE(mp). 184153323Srodrigc */ 185153323Srodrigcint xfs_dir_leaf_to_node(struct xfs_da_args *args); 186153323Srodrigcint xfs_dir_leaf_to_shortform(struct xfs_da_args *args); 187153323Srodrigc 188153323Srodrigc/* 189153323Srodrigc * Routines used for growing the Btree. 190153323Srodrigc */ 191153323Srodrigcint xfs_dir_leaf_split(struct xfs_da_state *state, 192153323Srodrigc struct xfs_da_state_blk *oldblk, 193153323Srodrigc struct xfs_da_state_blk *newblk); 194153323Srodrigcint xfs_dir_leaf_add(struct xfs_dabuf *leaf_buffer, 195153323Srodrigc struct xfs_da_args *args, int insertion_index); 196153323Srodrigcint xfs_dir_leaf_addname(struct xfs_da_args *args); 197153323Srodrigcint xfs_dir_leaf_lookup_int(struct xfs_dabuf *leaf_buffer, 198153323Srodrigc struct xfs_da_args *args, 199153323Srodrigc int *index_found_at); 200153323Srodrigcint xfs_dir_leaf_remove(struct xfs_trans *trans, 201153323Srodrigc struct xfs_dabuf *leaf_buffer, 202153323Srodrigc int index_to_remove); 203153323Srodrigcint xfs_dir_leaf_getdents_int(struct xfs_dabuf *bp, struct xfs_inode *dp, 204153323Srodrigc xfs_dablk_t bno, struct uio *uio, 205153323Srodrigc int *eobp, struct xfs_dirent *dbp, 206153323Srodrigc xfs_dir_put_t put, xfs_daddr_t nextda); 207153323Srodrigc 208153323Srodrigc/* 209153323Srodrigc * Routines used for shrinking the Btree. 210153323Srodrigc */ 211153323Srodrigcint xfs_dir_leaf_toosmall(struct xfs_da_state *state, int *retval); 212153323Srodrigcvoid xfs_dir_leaf_unbalance(struct xfs_da_state *state, 213153323Srodrigc struct xfs_da_state_blk *drop_blk, 214153323Srodrigc struct xfs_da_state_blk *save_blk); 215153323Srodrigc 216153323Srodrigc/* 217153323Srodrigc * Utility routines. 218153323Srodrigc */ 219153323Srodrigcuint xfs_dir_leaf_lasthash(struct xfs_dabuf *bp, int *count); 220153323Srodrigcint xfs_dir_leaf_order(struct xfs_dabuf *leaf1_bp, 221153323Srodrigc struct xfs_dabuf *leaf2_bp); 222153323Srodrigcint xfs_dir_put_dirent64_direct(xfs_dir_put_args_t *pa); 223153323Srodrigcint xfs_dir_put_dirent64_uio(xfs_dir_put_args_t *pa); 224153323Srodrigcint xfs_dir_ino_validate(struct xfs_mount *mp, xfs_ino_t ino); 225153323Srodrigc 226153323Srodrigc/* 227153323Srodrigc * Global data. 228153323Srodrigc */ 229153323Srodrigcextern xfs_dahash_t xfs_dir_hash_dot, xfs_dir_hash_dotdot; 230153323Srodrigc 231153323Srodrigc#endif /* __XFS_DIR_LEAF_H__ */ 232