1 /* 2 * Copyright (c) 2000, 2002-2003 Silicon Graphics, Inc. All Rights Reserved. 3 * 4 * This program is free software; you can redistribute it and/or modify it 5 * under the terms of version 2 of the GNU General Public License as 6 * published by the Free Software Foundation. 7 * 8 * This program is distributed in the hope that it would be useful, but 9 * WITHOUT ANY WARRANTY; without even the implied warranty of 10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. 11 * 12 * Further, this software is distributed without any warranty that it is 13 * free of the rightful claim of any third person regarding infringement 14 * or the like. Any license provided herein, whether implied or 15 * otherwise, applies only to this software file. Patent licenses, if 16 * any, provided herein do not apply to combinations of this program with 17 * other software, or any other product whatsoever. 18 * 19 * You should have received a copy of the GNU General Public License along 20 * with this program; if not, write the Free Software Foundation, Inc., 59 21 * Temple Place - Suite 330, Boston MA 02111-1307, USA. 22 * 23 * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy, 24 * Mountain View, CA 94043, or: 25 * 26 * http://www.sgi.com 27 * 28 * For further information regarding this notice, see: 29 * 30 * http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/ 31 */ 32 #ifndef __XFS_ATTR_LEAF_H__ 33 #define __XFS_ATTR_LEAF_H__ 34 35 /* 36 * Attribute storage layout, internal structure, access macros, etc. 37 * 38 * Attribute lists are structured around Btrees where all the data 39 * elements are in the leaf nodes. Attribute names are hashed into an int, 40 * then that int is used as the index into the Btree. Since the hashval 41 * of an attribute name may not be unique, we may have duplicate keys. The 42 * internal links in the Btree are logical block offsets into the file. 43 */ 44 45 struct attrlist; 46 struct attrlist_cursor_kern; 47 struct attrnames; 48 struct xfs_dabuf; 49 struct xfs_da_args; 50 struct xfs_da_state; 51 struct xfs_da_state_blk; 52 struct xfs_inode; 53 struct xfs_trans; 54 55 /*======================================================================== 56 * Attribute structure when equal to XFS_LBSIZE(mp) bytes. 57 *========================================================================*/ 58 59 /* 60 * This is the structure of the leaf nodes in the Btree. 61 * 62 * Struct leaf_entry's are packed from the top. Name/values grow from the 63 * bottom but are not packed. The freemap contains run-length-encoded entries 64 * for the free bytes after the leaf_entry's, but only the N largest such, 65 * smaller runs are dropped. When the freemap doesn't show enough space 66 * for an allocation, we compact the name/value area and try again. If we 67 * still don't have enough space, then we have to split the block. The 68 * name/value structs (both local and remote versions) must be 32bit aligned. 69 * 70 * Since we have duplicate hash keys, for each key that matches, compare 71 * the actual name string. The root and intermediate node search always 72 * takes the first-in-the-block key match found, so we should only have 73 * to work "forw"ard. If none matches, continue with the "forw"ard leaf 74 * nodes until the hash key changes or the attribute name is found. 75 * 76 * We store the fact that an attribute is a ROOT/USER/SECURE attribute in 77 * the leaf_entry. The namespaces are independent only because we also look 78 * at the namespace bit when we are looking for a matching attribute name. 79 * 80 * We also store a "incomplete" bit in the leaf_entry. It shows that an 81 * attribute is in the middle of being created and should not be shown to 82 * the user if we crash during the time that the bit is set. We clear the 83 * bit when we have finished setting up the attribute. We do this because 84 * we cannot create some large attributes inside a single transaction, and we 85 * need some indication that we weren't finished if we crash in the middle. 86 */ 87 #define XFS_ATTR_LEAF_MAPSIZE 3 /* how many freespace slots */ 88 89 typedef struct xfs_attr_leafblock { 90 struct xfs_attr_leaf_hdr { /* constant-structure header block */ 91 xfs_da_blkinfo_t info; /* block type, links, etc. */ 92 __uint16_t count; /* count of active leaf_entry's */ 93 __uint16_t usedbytes; /* num bytes of names/values stored */ 94 __uint16_t firstused; /* first used byte in name area */ 95 __uint8_t holes; /* != 0 if blk needs compaction */ 96 __uint8_t pad1; 97 struct xfs_attr_leaf_map { /* RLE map of free bytes */ 98 __uint16_t base; /* base of free region */ 99 __uint16_t size; /* length of free region */ 100 } freemap[XFS_ATTR_LEAF_MAPSIZE]; /* N largest free regions */ 101 } hdr; 102 struct xfs_attr_leaf_entry { /* sorted on key, not name */ 103 xfs_dahash_t hashval; /* hash value of name */ 104 __uint16_t nameidx; /* index into buffer of name/value */ 105 __uint8_t flags; /* LOCAL/ROOT/SECURE/INCOMPLETE flag */ 106 __uint8_t pad2; /* unused pad byte */ 107 } entries[1]; /* variable sized array */ 108 struct xfs_attr_leaf_name_local { 109 __uint16_t valuelen; /* number of bytes in value */ 110 __uint8_t namelen; /* length of name bytes */ 111 __uint8_t nameval[1]; /* name/value bytes */ 112 } namelist; /* grows from bottom of buf */ 113 struct xfs_attr_leaf_name_remote { 114 xfs_dablk_t valueblk; /* block number of value bytes */ 115 __uint32_t valuelen; /* number of bytes in value */ 116 __uint8_t namelen; /* length of name bytes */ 117 __uint8_t name[1]; /* name bytes */ 118 } valuelist; /* grows from bottom of buf */ 119 } xfs_attr_leafblock_t; 120 typedef struct xfs_attr_leaf_hdr xfs_attr_leaf_hdr_t; 121 typedef struct xfs_attr_leaf_map xfs_attr_leaf_map_t; 122 typedef struct xfs_attr_leaf_entry xfs_attr_leaf_entry_t; 123 typedef struct xfs_attr_leaf_name_local xfs_attr_leaf_name_local_t; 124 typedef struct xfs_attr_leaf_name_remote xfs_attr_leaf_name_remote_t; 125 126 /* 127 * Flags used in the leaf_entry[i].flags field. 128 * NOTE: the INCOMPLETE bit must not collide with the flags bits specified 129 * on the system call, they are "or"ed together for various operations. 130 */ 131 #define XFS_ATTR_LOCAL_BIT 0 /* attr is stored locally */ 132 #define XFS_ATTR_ROOT_BIT 1 /* limit access to trusted attrs */ 133 #define XFS_ATTR_SECURE_BIT 2 /* limit access to secure attrs */ 134 #define XFS_ATTR_INCOMPLETE_BIT 7 /* attr in middle of create/delete */ 135 #define XFS_ATTR_LOCAL (1 << XFS_ATTR_LOCAL_BIT) 136 #define XFS_ATTR_ROOT (1 << XFS_ATTR_ROOT_BIT) 137 #define XFS_ATTR_SECURE (1 << XFS_ATTR_SECURE_BIT) 138 #define XFS_ATTR_INCOMPLETE (1 << XFS_ATTR_INCOMPLETE_BIT) 139 140 /* 141 * Alignment for namelist and valuelist entries (since they are mixed 142 * there can be only one alignment value) 143 */ 144 #define XFS_ATTR_LEAF_NAME_ALIGN ((uint)sizeof(xfs_dablk_t)) 145 146 /* 147 * Cast typed pointers for "local" and "remote" name/value structs. 148 */ 149 #if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_ATTR_LEAF_NAME_REMOTE) 150 xfs_attr_leaf_name_remote_t * 151 xfs_attr_leaf_name_remote(xfs_attr_leafblock_t *leafp, int idx); 152 #define XFS_ATTR_LEAF_NAME_REMOTE(leafp,idx) \ 153 xfs_attr_leaf_name_remote(leafp,idx) 154 #else 155 #define XFS_ATTR_LEAF_NAME_REMOTE(leafp,idx) /* remote name struct ptr */ \ 156 ((xfs_attr_leaf_name_remote_t *) \ 157 &((char *)(leafp))[ INT_GET((leafp)->entries[idx].nameidx, ARCH_CONVERT) ]) 158 #endif 159 #if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_ATTR_LEAF_NAME_LOCAL) 160 xfs_attr_leaf_name_local_t * 161 xfs_attr_leaf_name_local(xfs_attr_leafblock_t *leafp, int idx); 162 #define XFS_ATTR_LEAF_NAME_LOCAL(leafp,idx) \ 163 xfs_attr_leaf_name_local(leafp,idx) 164 #else 165 #define XFS_ATTR_LEAF_NAME_LOCAL(leafp,idx) /* local name struct ptr */ \ 166 ((xfs_attr_leaf_name_local_t *) \ 167 &((char *)(leafp))[ INT_GET((leafp)->entries[idx].nameidx, ARCH_CONVERT) ]) 168 #endif 169 #if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_ATTR_LEAF_NAME) 170 char *xfs_attr_leaf_name(xfs_attr_leafblock_t *leafp, int idx); 171 #define XFS_ATTR_LEAF_NAME(leafp,idx) xfs_attr_leaf_name(leafp,idx) 172 #else 173 #define XFS_ATTR_LEAF_NAME(leafp,idx) /* generic name struct ptr */ \ 174 (&((char *)(leafp))[ INT_GET((leafp)->entries[idx].nameidx, ARCH_CONVERT) ]) 175 #endif 176 177 /* 178 * Calculate total bytes used (including trailing pad for alignment) for 179 * a "local" name/value structure, a "remote" name/value structure, and 180 * a pointer which might be either. 181 */ 182 #if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_ATTR_LEAF_ENTSIZE_REMOTE) 183 int xfs_attr_leaf_entsize_remote(int nlen); 184 #define XFS_ATTR_LEAF_ENTSIZE_REMOTE(nlen) \ 185 xfs_attr_leaf_entsize_remote(nlen) 186 #else 187 #define XFS_ATTR_LEAF_ENTSIZE_REMOTE(nlen) /* space for remote struct */ \ 188 (((uint)sizeof(xfs_attr_leaf_name_remote_t) - 1 + (nlen) + \ 189 XFS_ATTR_LEAF_NAME_ALIGN - 1) & ~(XFS_ATTR_LEAF_NAME_ALIGN - 1)) 190 #endif 191 #if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_ATTR_LEAF_ENTSIZE_LOCAL) 192 int xfs_attr_leaf_entsize_local(int nlen, int vlen); 193 #define XFS_ATTR_LEAF_ENTSIZE_LOCAL(nlen,vlen) \ 194 xfs_attr_leaf_entsize_local(nlen,vlen) 195 #else 196 #define XFS_ATTR_LEAF_ENTSIZE_LOCAL(nlen,vlen) /* space for local struct */ \ 197 (((uint)sizeof(xfs_attr_leaf_name_local_t) - 1 + (nlen) + (vlen) + \ 198 XFS_ATTR_LEAF_NAME_ALIGN - 1) & ~(XFS_ATTR_LEAF_NAME_ALIGN - 1)) 199 #endif 200 #if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_ATTR_LEAF_ENTSIZE_LOCAL_MAX) 201 int xfs_attr_leaf_entsize_local_max(int bsize); 202 #define XFS_ATTR_LEAF_ENTSIZE_LOCAL_MAX(bsize) \ 203 xfs_attr_leaf_entsize_local_max(bsize) 204 #else 205 #define XFS_ATTR_LEAF_ENTSIZE_LOCAL_MAX(bsize) /* max local struct size */ \ 206 (((bsize) >> 1) + ((bsize) >> 2)) 207 #endif 208 209 210 /*======================================================================== 211 * Structure used to pass context around among the routines. 212 *========================================================================*/ 213 214 typedef struct xfs_attr_list_context { 215 struct xfs_inode *dp; /* inode */ 216 struct attrlist_cursor_kern *cursor;/* position in list */ 217 struct attrlist *alist; /* output buffer */ 218 int count; /* num used entries */ 219 int dupcnt; /* count dup hashvals seen */ 220 int bufsize;/* total buffer size */ 221 int firstu; /* first used byte in buffer */ 222 int flags; /* from VOP call */ 223 int resynch;/* T/F: resynch with cursor */ 224 } xfs_attr_list_context_t; 225 226 /* 227 * Used to keep a list of "remote value" extents when unlinking an inode. 228 */ 229 typedef struct xfs_attr_inactive_list { 230 xfs_dablk_t valueblk; /* block number of value bytes */ 231 int valuelen; /* number of bytes in value */ 232 } xfs_attr_inactive_list_t; 233 234 235 /*======================================================================== 236 * Function prototypes for the kernel. 237 *========================================================================*/ 238 239 /* 240 * Internal routines when dirsize < XFS_LITINO(mp). 241 */ 242 int xfs_attr_shortform_create(struct xfs_da_args *args); 243 int xfs_attr_shortform_add(struct xfs_da_args *add); 244 int xfs_attr_shortform_lookup(struct xfs_da_args *args); 245 int xfs_attr_shortform_getvalue(struct xfs_da_args *args); 246 int xfs_attr_shortform_to_leaf(struct xfs_da_args *args); 247 int xfs_attr_shortform_remove(struct xfs_da_args *remove); 248 int xfs_attr_shortform_list(struct xfs_attr_list_context *context); 249 int xfs_attr_shortform_allfit(struct xfs_dabuf *bp, struct xfs_inode *dp); 250 251 /* 252 * Internal routines when dirsize == XFS_LBSIZE(mp). 253 */ 254 int xfs_attr_leaf_to_node(struct xfs_da_args *args); 255 int xfs_attr_leaf_to_shortform(struct xfs_dabuf *bp, 256 struct xfs_da_args *args); 257 int xfs_attr_leaf_clearflag(struct xfs_da_args *args); 258 int xfs_attr_leaf_setflag(struct xfs_da_args *args); 259 int xfs_attr_leaf_flipflags(xfs_da_args_t *args); 260 261 /* 262 * Routines used for growing the Btree. 263 */ 264 int xfs_attr_leaf_create(struct xfs_da_args *args, xfs_dablk_t which_block, 265 struct xfs_dabuf **bpp); 266 int xfs_attr_leaf_split(struct xfs_da_state *state, 267 struct xfs_da_state_blk *oldblk, 268 struct xfs_da_state_blk *newblk); 269 int xfs_attr_leaf_lookup_int(struct xfs_dabuf *leaf, 270 struct xfs_da_args *args); 271 int xfs_attr_leaf_getvalue(struct xfs_dabuf *bp, struct xfs_da_args *args); 272 int xfs_attr_leaf_add(struct xfs_dabuf *leaf_buffer, 273 struct xfs_da_args *args); 274 int xfs_attr_leaf_remove(struct xfs_dabuf *leaf_buffer, 275 struct xfs_da_args *args); 276 int xfs_attr_leaf_list_int(struct xfs_dabuf *bp, 277 struct xfs_attr_list_context *context); 278 279 /* 280 * Routines used for shrinking the Btree. 281 */ 282 int xfs_attr_leaf_toosmall(struct xfs_da_state *state, int *retval); 283 void xfs_attr_leaf_unbalance(struct xfs_da_state *state, 284 struct xfs_da_state_blk *drop_blk, 285 struct xfs_da_state_blk *save_blk); 286 int xfs_attr_root_inactive(struct xfs_trans **trans, struct xfs_inode *dp); 287 int xfs_attr_node_inactive(struct xfs_trans **trans, struct xfs_inode *dp, 288 struct xfs_dabuf *bp, int level); 289 int xfs_attr_leaf_inactive(struct xfs_trans **trans, struct xfs_inode *dp, 290 struct xfs_dabuf *bp); 291 int xfs_attr_leaf_freextent(struct xfs_trans **trans, struct xfs_inode *dp, 292 xfs_dablk_t blkno, int blkcnt); 293 294 /* 295 * Utility routines. 296 */ 297 xfs_dahash_t xfs_attr_leaf_lasthash(struct xfs_dabuf *bp, int *count); 298 int xfs_attr_leaf_order(struct xfs_dabuf *leaf1_bp, 299 struct xfs_dabuf *leaf2_bp); 300 int xfs_attr_leaf_newentsize(struct xfs_da_args *args, int blocksize, 301 int *local); 302 int xfs_attr_leaf_entsize(struct xfs_attr_leafblock *leaf, int index); 303 int xfs_attr_put_listent(struct xfs_attr_list_context *context, 304 struct attrnames *, char *name, int namelen, 305 int valuelen); 306 int xfs_attr_rolltrans(struct xfs_trans **transp, struct xfs_inode *dp); 307 308 #endif /* __XFS_ATTR_LEAF_H__ */ 309