Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
Nathan Scott | aa82daa | 2005-11-02 10:33:33 +1100 | [diff] [blame] | 2 | * Copyright (c) 2000, 2002-2003, 2005 Silicon Graphics, Inc. |
| 3 | * All Rights Reserved. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4 | * |
| 5 | * This program is free software; you can redistribute it and/or modify it |
| 6 | * under the terms of version 2 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, but |
| 10 | * WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. |
| 12 | * |
| 13 | * Further, this software is distributed without any warranty that it is |
| 14 | * free of the rightful claim of any third person regarding infringement |
| 15 | * or the like. Any license provided herein, whether implied or |
| 16 | * otherwise, applies only to this software file. Patent licenses, if |
| 17 | * any, provided herein do not apply to combinations of this program with |
| 18 | * other software, or any other product whatsoever. |
| 19 | * |
| 20 | * You should have received a copy of the GNU General Public License along |
| 21 | * with this program; if not, write the Free Software Foundation, Inc., 59 |
| 22 | * Temple Place - Suite 330, Boston MA 02111-1307, USA. |
| 23 | * |
| 24 | * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy, |
| 25 | * Mountain View, CA 94043, or: |
| 26 | * |
| 27 | * http://www.sgi.com |
| 28 | * |
| 29 | * For further information regarding this notice, see: |
| 30 | * |
| 31 | * http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/ |
| 32 | */ |
| 33 | #ifndef __XFS_ATTR_LEAF_H__ |
| 34 | #define __XFS_ATTR_LEAF_H__ |
| 35 | |
| 36 | /* |
| 37 | * Attribute storage layout, internal structure, access macros, etc. |
| 38 | * |
| 39 | * Attribute lists are structured around Btrees where all the data |
| 40 | * elements are in the leaf nodes. Attribute names are hashed into an int, |
| 41 | * then that int is used as the index into the Btree. Since the hashval |
| 42 | * of an attribute name may not be unique, we may have duplicate keys. The |
| 43 | * internal links in the Btree are logical block offsets into the file. |
| 44 | */ |
| 45 | |
| 46 | struct attrlist; |
| 47 | struct attrlist_cursor_kern; |
| 48 | struct attrnames; |
| 49 | struct xfs_dabuf; |
| 50 | struct xfs_da_args; |
| 51 | struct xfs_da_state; |
| 52 | struct xfs_da_state_blk; |
| 53 | struct xfs_inode; |
| 54 | struct xfs_trans; |
| 55 | |
| 56 | /*======================================================================== |
| 57 | * Attribute structure when equal to XFS_LBSIZE(mp) bytes. |
| 58 | *========================================================================*/ |
| 59 | |
| 60 | /* |
| 61 | * This is the structure of the leaf nodes in the Btree. |
| 62 | * |
| 63 | * Struct leaf_entry's are packed from the top. Name/values grow from the |
| 64 | * bottom but are not packed. The freemap contains run-length-encoded entries |
| 65 | * for the free bytes after the leaf_entry's, but only the N largest such, |
| 66 | * smaller runs are dropped. When the freemap doesn't show enough space |
| 67 | * for an allocation, we compact the name/value area and try again. If we |
| 68 | * still don't have enough space, then we have to split the block. The |
| 69 | * name/value structs (both local and remote versions) must be 32bit aligned. |
| 70 | * |
| 71 | * Since we have duplicate hash keys, for each key that matches, compare |
| 72 | * the actual name string. The root and intermediate node search always |
| 73 | * takes the first-in-the-block key match found, so we should only have |
| 74 | * to work "forw"ard. If none matches, continue with the "forw"ard leaf |
| 75 | * nodes until the hash key changes or the attribute name is found. |
| 76 | * |
| 77 | * We store the fact that an attribute is a ROOT/USER/SECURE attribute in |
| 78 | * the leaf_entry. The namespaces are independent only because we also look |
| 79 | * at the namespace bit when we are looking for a matching attribute name. |
| 80 | * |
| 81 | * We also store a "incomplete" bit in the leaf_entry. It shows that an |
| 82 | * attribute is in the middle of being created and should not be shown to |
| 83 | * the user if we crash during the time that the bit is set. We clear the |
| 84 | * bit when we have finished setting up the attribute. We do this because |
| 85 | * we cannot create some large attributes inside a single transaction, and we |
| 86 | * need some indication that we weren't finished if we crash in the middle. |
| 87 | */ |
| 88 | #define XFS_ATTR_LEAF_MAPSIZE 3 /* how many freespace slots */ |
| 89 | |
| 90 | typedef struct xfs_attr_leafblock { |
| 91 | struct xfs_attr_leaf_hdr { /* constant-structure header block */ |
| 92 | xfs_da_blkinfo_t info; /* block type, links, etc. */ |
| 93 | __uint16_t count; /* count of active leaf_entry's */ |
| 94 | __uint16_t usedbytes; /* num bytes of names/values stored */ |
| 95 | __uint16_t firstused; /* first used byte in name area */ |
| 96 | __uint8_t holes; /* != 0 if blk needs compaction */ |
| 97 | __uint8_t pad1; |
| 98 | struct xfs_attr_leaf_map { /* RLE map of free bytes */ |
| 99 | __uint16_t base; /* base of free region */ |
| 100 | __uint16_t size; /* length of free region */ |
| 101 | } freemap[XFS_ATTR_LEAF_MAPSIZE]; /* N largest free regions */ |
| 102 | } hdr; |
| 103 | struct xfs_attr_leaf_entry { /* sorted on key, not name */ |
| 104 | xfs_dahash_t hashval; /* hash value of name */ |
| 105 | __uint16_t nameidx; /* index into buffer of name/value */ |
| 106 | __uint8_t flags; /* LOCAL/ROOT/SECURE/INCOMPLETE flag */ |
| 107 | __uint8_t pad2; /* unused pad byte */ |
| 108 | } entries[1]; /* variable sized array */ |
| 109 | struct xfs_attr_leaf_name_local { |
| 110 | __uint16_t valuelen; /* number of bytes in value */ |
| 111 | __uint8_t namelen; /* length of name bytes */ |
| 112 | __uint8_t nameval[1]; /* name/value bytes */ |
| 113 | } namelist; /* grows from bottom of buf */ |
| 114 | struct xfs_attr_leaf_name_remote { |
| 115 | xfs_dablk_t valueblk; /* block number of value bytes */ |
| 116 | __uint32_t valuelen; /* number of bytes in value */ |
| 117 | __uint8_t namelen; /* length of name bytes */ |
| 118 | __uint8_t name[1]; /* name bytes */ |
| 119 | } valuelist; /* grows from bottom of buf */ |
| 120 | } xfs_attr_leafblock_t; |
| 121 | typedef struct xfs_attr_leaf_hdr xfs_attr_leaf_hdr_t; |
| 122 | typedef struct xfs_attr_leaf_map xfs_attr_leaf_map_t; |
| 123 | typedef struct xfs_attr_leaf_entry xfs_attr_leaf_entry_t; |
| 124 | typedef struct xfs_attr_leaf_name_local xfs_attr_leaf_name_local_t; |
| 125 | typedef struct xfs_attr_leaf_name_remote xfs_attr_leaf_name_remote_t; |
| 126 | |
| 127 | /* |
| 128 | * Flags used in the leaf_entry[i].flags field. |
| 129 | * NOTE: the INCOMPLETE bit must not collide with the flags bits specified |
| 130 | * on the system call, they are "or"ed together for various operations. |
| 131 | */ |
| 132 | #define XFS_ATTR_LOCAL_BIT 0 /* attr is stored locally */ |
| 133 | #define XFS_ATTR_ROOT_BIT 1 /* limit access to trusted attrs */ |
| 134 | #define XFS_ATTR_SECURE_BIT 2 /* limit access to secure attrs */ |
| 135 | #define XFS_ATTR_INCOMPLETE_BIT 7 /* attr in middle of create/delete */ |
| 136 | #define XFS_ATTR_LOCAL (1 << XFS_ATTR_LOCAL_BIT) |
| 137 | #define XFS_ATTR_ROOT (1 << XFS_ATTR_ROOT_BIT) |
| 138 | #define XFS_ATTR_SECURE (1 << XFS_ATTR_SECURE_BIT) |
| 139 | #define XFS_ATTR_INCOMPLETE (1 << XFS_ATTR_INCOMPLETE_BIT) |
| 140 | |
| 141 | /* |
| 142 | * Alignment for namelist and valuelist entries (since they are mixed |
| 143 | * there can be only one alignment value) |
| 144 | */ |
| 145 | #define XFS_ATTR_LEAF_NAME_ALIGN ((uint)sizeof(xfs_dablk_t)) |
| 146 | |
| 147 | /* |
| 148 | * Cast typed pointers for "local" and "remote" name/value structs. |
| 149 | */ |
| 150 | #if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_ATTR_LEAF_NAME_REMOTE) |
| 151 | xfs_attr_leaf_name_remote_t * |
| 152 | xfs_attr_leaf_name_remote(xfs_attr_leafblock_t *leafp, int idx); |
| 153 | #define XFS_ATTR_LEAF_NAME_REMOTE(leafp,idx) \ |
| 154 | xfs_attr_leaf_name_remote(leafp,idx) |
| 155 | #else |
| 156 | #define XFS_ATTR_LEAF_NAME_REMOTE(leafp,idx) /* remote name struct ptr */ \ |
| 157 | ((xfs_attr_leaf_name_remote_t *) \ |
| 158 | &((char *)(leafp))[ INT_GET((leafp)->entries[idx].nameidx, ARCH_CONVERT) ]) |
| 159 | #endif |
| 160 | #if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_ATTR_LEAF_NAME_LOCAL) |
| 161 | xfs_attr_leaf_name_local_t * |
| 162 | xfs_attr_leaf_name_local(xfs_attr_leafblock_t *leafp, int idx); |
| 163 | #define XFS_ATTR_LEAF_NAME_LOCAL(leafp,idx) \ |
| 164 | xfs_attr_leaf_name_local(leafp,idx) |
| 165 | #else |
| 166 | #define XFS_ATTR_LEAF_NAME_LOCAL(leafp,idx) /* local name struct ptr */ \ |
| 167 | ((xfs_attr_leaf_name_local_t *) \ |
| 168 | &((char *)(leafp))[ INT_GET((leafp)->entries[idx].nameidx, ARCH_CONVERT) ]) |
| 169 | #endif |
| 170 | #if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_ATTR_LEAF_NAME) |
| 171 | char *xfs_attr_leaf_name(xfs_attr_leafblock_t *leafp, int idx); |
| 172 | #define XFS_ATTR_LEAF_NAME(leafp,idx) xfs_attr_leaf_name(leafp,idx) |
| 173 | #else |
| 174 | #define XFS_ATTR_LEAF_NAME(leafp,idx) /* generic name struct ptr */ \ |
| 175 | (&((char *)(leafp))[ INT_GET((leafp)->entries[idx].nameidx, ARCH_CONVERT) ]) |
| 176 | #endif |
| 177 | |
| 178 | /* |
| 179 | * Calculate total bytes used (including trailing pad for alignment) for |
| 180 | * a "local" name/value structure, a "remote" name/value structure, and |
| 181 | * a pointer which might be either. |
| 182 | */ |
| 183 | #if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_ATTR_LEAF_ENTSIZE_REMOTE) |
| 184 | int xfs_attr_leaf_entsize_remote(int nlen); |
| 185 | #define XFS_ATTR_LEAF_ENTSIZE_REMOTE(nlen) \ |
| 186 | xfs_attr_leaf_entsize_remote(nlen) |
| 187 | #else |
| 188 | #define XFS_ATTR_LEAF_ENTSIZE_REMOTE(nlen) /* space for remote struct */ \ |
| 189 | (((uint)sizeof(xfs_attr_leaf_name_remote_t) - 1 + (nlen) + \ |
| 190 | XFS_ATTR_LEAF_NAME_ALIGN - 1) & ~(XFS_ATTR_LEAF_NAME_ALIGN - 1)) |
| 191 | #endif |
| 192 | #if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_ATTR_LEAF_ENTSIZE_LOCAL) |
| 193 | int xfs_attr_leaf_entsize_local(int nlen, int vlen); |
| 194 | #define XFS_ATTR_LEAF_ENTSIZE_LOCAL(nlen,vlen) \ |
| 195 | xfs_attr_leaf_entsize_local(nlen,vlen) |
| 196 | #else |
| 197 | #define XFS_ATTR_LEAF_ENTSIZE_LOCAL(nlen,vlen) /* space for local struct */ \ |
| 198 | (((uint)sizeof(xfs_attr_leaf_name_local_t) - 1 + (nlen) + (vlen) + \ |
| 199 | XFS_ATTR_LEAF_NAME_ALIGN - 1) & ~(XFS_ATTR_LEAF_NAME_ALIGN - 1)) |
| 200 | #endif |
| 201 | #if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_ATTR_LEAF_ENTSIZE_LOCAL_MAX) |
| 202 | int xfs_attr_leaf_entsize_local_max(int bsize); |
| 203 | #define XFS_ATTR_LEAF_ENTSIZE_LOCAL_MAX(bsize) \ |
| 204 | xfs_attr_leaf_entsize_local_max(bsize) |
| 205 | #else |
| 206 | #define XFS_ATTR_LEAF_ENTSIZE_LOCAL_MAX(bsize) /* max local struct size */ \ |
| 207 | (((bsize) >> 1) + ((bsize) >> 2)) |
| 208 | #endif |
| 209 | |
| 210 | |
| 211 | /*======================================================================== |
| 212 | * Structure used to pass context around among the routines. |
| 213 | *========================================================================*/ |
| 214 | |
| 215 | typedef struct xfs_attr_list_context { |
| 216 | struct xfs_inode *dp; /* inode */ |
| 217 | struct attrlist_cursor_kern *cursor;/* position in list */ |
| 218 | struct attrlist *alist; /* output buffer */ |
| 219 | int count; /* num used entries */ |
| 220 | int dupcnt; /* count dup hashvals seen */ |
| 221 | int bufsize;/* total buffer size */ |
| 222 | int firstu; /* first used byte in buffer */ |
| 223 | int flags; /* from VOP call */ |
| 224 | int resynch;/* T/F: resynch with cursor */ |
| 225 | } xfs_attr_list_context_t; |
| 226 | |
| 227 | /* |
| 228 | * Used to keep a list of "remote value" extents when unlinking an inode. |
| 229 | */ |
| 230 | typedef struct xfs_attr_inactive_list { |
| 231 | xfs_dablk_t valueblk; /* block number of value bytes */ |
| 232 | int valuelen; /* number of bytes in value */ |
| 233 | } xfs_attr_inactive_list_t; |
| 234 | |
| 235 | |
| 236 | /*======================================================================== |
| 237 | * Function prototypes for the kernel. |
| 238 | *========================================================================*/ |
| 239 | |
| 240 | /* |
Nathan Scott | d8cc890 | 2005-11-02 10:34:53 +1100 | [diff] [blame^] | 241 | * Internal routines when attribute fork size < XFS_LITINO(mp). |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 242 | */ |
Nathan Scott | d8cc890 | 2005-11-02 10:34:53 +1100 | [diff] [blame^] | 243 | void xfs_attr_shortform_create(struct xfs_da_args *args); |
| 244 | void xfs_attr_shortform_add(struct xfs_da_args *args, int forkoff); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 245 | int xfs_attr_shortform_lookup(struct xfs_da_args *args); |
| 246 | int xfs_attr_shortform_getvalue(struct xfs_da_args *args); |
| 247 | int xfs_attr_shortform_to_leaf(struct xfs_da_args *args); |
Nathan Scott | d8cc890 | 2005-11-02 10:34:53 +1100 | [diff] [blame^] | 248 | int xfs_attr_shortform_remove(struct xfs_da_args *args); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 249 | int xfs_attr_shortform_list(struct xfs_attr_list_context *context); |
| 250 | int xfs_attr_shortform_allfit(struct xfs_dabuf *bp, struct xfs_inode *dp); |
Nathan Scott | d8cc890 | 2005-11-02 10:34:53 +1100 | [diff] [blame^] | 251 | int xfs_attr_shortform_bytesfit(xfs_inode_t *dp, int bytes); |
| 252 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 253 | |
| 254 | /* |
Nathan Scott | d8cc890 | 2005-11-02 10:34:53 +1100 | [diff] [blame^] | 255 | * Internal routines when attribute fork size == XFS_LBSIZE(mp). |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 256 | */ |
| 257 | int xfs_attr_leaf_to_node(struct xfs_da_args *args); |
| 258 | int xfs_attr_leaf_to_shortform(struct xfs_dabuf *bp, |
Nathan Scott | d8cc890 | 2005-11-02 10:34:53 +1100 | [diff] [blame^] | 259 | struct xfs_da_args *args, int forkoff); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 260 | int xfs_attr_leaf_clearflag(struct xfs_da_args *args); |
| 261 | int xfs_attr_leaf_setflag(struct xfs_da_args *args); |
| 262 | int xfs_attr_leaf_flipflags(xfs_da_args_t *args); |
| 263 | |
| 264 | /* |
| 265 | * Routines used for growing the Btree. |
| 266 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 267 | int xfs_attr_leaf_split(struct xfs_da_state *state, |
| 268 | struct xfs_da_state_blk *oldblk, |
| 269 | struct xfs_da_state_blk *newblk); |
| 270 | int xfs_attr_leaf_lookup_int(struct xfs_dabuf *leaf, |
| 271 | struct xfs_da_args *args); |
| 272 | int xfs_attr_leaf_getvalue(struct xfs_dabuf *bp, struct xfs_da_args *args); |
| 273 | int xfs_attr_leaf_add(struct xfs_dabuf *leaf_buffer, |
| 274 | struct xfs_da_args *args); |
| 275 | int xfs_attr_leaf_remove(struct xfs_dabuf *leaf_buffer, |
| 276 | struct xfs_da_args *args); |
| 277 | int xfs_attr_leaf_list_int(struct xfs_dabuf *bp, |
| 278 | struct xfs_attr_list_context *context); |
| 279 | |
| 280 | /* |
| 281 | * Routines used for shrinking the Btree. |
| 282 | */ |
| 283 | int xfs_attr_leaf_toosmall(struct xfs_da_state *state, int *retval); |
| 284 | void xfs_attr_leaf_unbalance(struct xfs_da_state *state, |
| 285 | struct xfs_da_state_blk *drop_blk, |
| 286 | struct xfs_da_state_blk *save_blk); |
| 287 | int xfs_attr_root_inactive(struct xfs_trans **trans, struct xfs_inode *dp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 288 | |
| 289 | /* |
| 290 | * Utility routines. |
| 291 | */ |
| 292 | xfs_dahash_t xfs_attr_leaf_lasthash(struct xfs_dabuf *bp, int *count); |
| 293 | int xfs_attr_leaf_order(struct xfs_dabuf *leaf1_bp, |
| 294 | struct xfs_dabuf *leaf2_bp); |
Nathan Scott | aa82daa | 2005-11-02 10:33:33 +1100 | [diff] [blame] | 295 | int xfs_attr_leaf_newentsize(int namelen, int valuelen, int blocksize, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 296 | int *local); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 297 | int xfs_attr_rolltrans(struct xfs_trans **transp, struct xfs_inode *dp); |
| 298 | |
| 299 | #endif /* __XFS_ATTR_LEAF_H__ */ |