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1da177e4 | 1 | /* |
7b718769 | 2 | * Copyright (c) 2000,2002-2003,2005 Silicon Graphics, Inc. |
aa82daa0 | 3 | * All Rights Reserved. |
1da177e4 | 4 | * |
7b718769 NS |
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 | |
1da177e4 LT |
7 | * published by the Free Software Foundation. |
8 | * | |
7b718769 NS |
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. | |
1da177e4 | 13 | * |
7b718769 NS |
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 | |
1da177e4 LT |
17 | */ |
18 | #ifndef __XFS_ATTR_LEAF_H__ | |
19 | #define __XFS_ATTR_LEAF_H__ | |
20 | ||
21 | /* | |
22 | * Attribute storage layout, internal structure, access macros, etc. | |
23 | * | |
24 | * Attribute lists are structured around Btrees where all the data | |
25 | * elements are in the leaf nodes. Attribute names are hashed into an int, | |
26 | * then that int is used as the index into the Btree. Since the hashval | |
27 | * of an attribute name may not be unique, we may have duplicate keys. The | |
28 | * internal links in the Btree are logical block offsets into the file. | |
29 | */ | |
30 | ||
31 | struct attrlist; | |
32 | struct attrlist_cursor_kern; | |
33 | struct attrnames; | |
34 | struct xfs_dabuf; | |
35 | struct xfs_da_args; | |
36 | struct xfs_da_state; | |
37 | struct xfs_da_state_blk; | |
38 | struct xfs_inode; | |
39 | struct xfs_trans; | |
40 | ||
41 | /*======================================================================== | |
42 | * Attribute structure when equal to XFS_LBSIZE(mp) bytes. | |
43 | *========================================================================*/ | |
44 | ||
45 | /* | |
46 | * This is the structure of the leaf nodes in the Btree. | |
47 | * | |
48 | * Struct leaf_entry's are packed from the top. Name/values grow from the | |
49 | * bottom but are not packed. The freemap contains run-length-encoded entries | |
50 | * for the free bytes after the leaf_entry's, but only the N largest such, | |
51 | * smaller runs are dropped. When the freemap doesn't show enough space | |
52 | * for an allocation, we compact the name/value area and try again. If we | |
53 | * still don't have enough space, then we have to split the block. The | |
54 | * name/value structs (both local and remote versions) must be 32bit aligned. | |
55 | * | |
56 | * Since we have duplicate hash keys, for each key that matches, compare | |
57 | * the actual name string. The root and intermediate node search always | |
58 | * takes the first-in-the-block key match found, so we should only have | |
59 | * to work "forw"ard. If none matches, continue with the "forw"ard leaf | |
60 | * nodes until the hash key changes or the attribute name is found. | |
61 | * | |
62 | * We store the fact that an attribute is a ROOT/USER/SECURE attribute in | |
63 | * the leaf_entry. The namespaces are independent only because we also look | |
64 | * at the namespace bit when we are looking for a matching attribute name. | |
65 | * | |
3762ec6b | 66 | * We also store an "incomplete" bit in the leaf_entry. It shows that an |
1da177e4 LT |
67 | * attribute is in the middle of being created and should not be shown to |
68 | * the user if we crash during the time that the bit is set. We clear the | |
69 | * bit when we have finished setting up the attribute. We do this because | |
70 | * we cannot create some large attributes inside a single transaction, and we | |
71 | * need some indication that we weren't finished if we crash in the middle. | |
72 | */ | |
73 | #define XFS_ATTR_LEAF_MAPSIZE 3 /* how many freespace slots */ | |
74 | ||
3762ec6b | 75 | typedef struct xfs_attr_leaf_map { /* RLE map of free bytes */ |
918ae424 NS |
76 | __be16 base; /* base of free region */ |
77 | __be16 size; /* length of free region */ | |
3762ec6b NS |
78 | } xfs_attr_leaf_map_t; |
79 | ||
80 | typedef struct xfs_attr_leaf_hdr { /* constant-structure header block */ | |
81 | xfs_da_blkinfo_t info; /* block type, links, etc. */ | |
918ae424 NS |
82 | __be16 count; /* count of active leaf_entry's */ |
83 | __be16 usedbytes; /* num bytes of names/values stored */ | |
84 | __be16 firstused; /* first used byte in name area */ | |
85 | __u8 holes; /* != 0 if blk needs compaction */ | |
86 | __u8 pad1; | |
3762ec6b NS |
87 | xfs_attr_leaf_map_t freemap[XFS_ATTR_LEAF_MAPSIZE]; |
88 | /* N largest free regions */ | |
89 | } xfs_attr_leaf_hdr_t; | |
90 | ||
91 | typedef struct xfs_attr_leaf_entry { /* sorted on key, not name */ | |
6b19f2d8 NS |
92 | __be32 hashval; /* hash value of name */ |
93 | __be16 nameidx; /* index into buffer of name/value */ | |
94 | __u8 flags; /* LOCAL/ROOT/SECURE/INCOMPLETE flag */ | |
95 | __u8 pad2; /* unused pad byte */ | |
3762ec6b NS |
96 | } xfs_attr_leaf_entry_t; |
97 | ||
98 | typedef struct xfs_attr_leaf_name_local { | |
053b5758 NS |
99 | __be16 valuelen; /* number of bytes in value */ |
100 | __u8 namelen; /* length of name bytes */ | |
101 | __u8 nameval[1]; /* name/value bytes */ | |
3762ec6b NS |
102 | } xfs_attr_leaf_name_local_t; |
103 | ||
104 | typedef struct xfs_attr_leaf_name_remote { | |
c0f054e7 NS |
105 | __be32 valueblk; /* block number of value bytes */ |
106 | __be32 valuelen; /* number of bytes in value */ | |
107 | __u8 namelen; /* length of name bytes */ | |
108 | __u8 name[1]; /* name bytes */ | |
3762ec6b NS |
109 | } xfs_attr_leaf_name_remote_t; |
110 | ||
1da177e4 | 111 | typedef struct xfs_attr_leafblock { |
3762ec6b NS |
112 | xfs_attr_leaf_hdr_t hdr; /* constant-structure header block */ |
113 | xfs_attr_leaf_entry_t entries[1]; /* sorted on key, not name */ | |
114 | xfs_attr_leaf_name_local_t namelist; /* grows from bottom of buf */ | |
115 | xfs_attr_leaf_name_remote_t valuelist; /* grows from bottom of buf */ | |
1da177e4 | 116 | } xfs_attr_leafblock_t; |
1da177e4 LT |
117 | |
118 | /* | |
119 | * Flags used in the leaf_entry[i].flags field. | |
120 | * NOTE: the INCOMPLETE bit must not collide with the flags bits specified | |
121 | * on the system call, they are "or"ed together for various operations. | |
122 | */ | |
123 | #define XFS_ATTR_LOCAL_BIT 0 /* attr is stored locally */ | |
124 | #define XFS_ATTR_ROOT_BIT 1 /* limit access to trusted attrs */ | |
125 | #define XFS_ATTR_SECURE_BIT 2 /* limit access to secure attrs */ | |
126 | #define XFS_ATTR_INCOMPLETE_BIT 7 /* attr in middle of create/delete */ | |
127 | #define XFS_ATTR_LOCAL (1 << XFS_ATTR_LOCAL_BIT) | |
128 | #define XFS_ATTR_ROOT (1 << XFS_ATTR_ROOT_BIT) | |
129 | #define XFS_ATTR_SECURE (1 << XFS_ATTR_SECURE_BIT) | |
130 | #define XFS_ATTR_INCOMPLETE (1 << XFS_ATTR_INCOMPLETE_BIT) | |
131 | ||
726801ba TS |
132 | /* |
133 | * Conversion macros for converting namespace bits from argument flags | |
134 | * to ondisk flags. | |
135 | */ | |
136 | #define XFS_ATTR_NSP_ARGS_MASK (ATTR_ROOT | ATTR_SECURE) | |
137 | #define XFS_ATTR_NSP_ONDISK_MASK (XFS_ATTR_ROOT | XFS_ATTR_SECURE) | |
138 | #define XFS_ATTR_NSP_ONDISK(flags) ((flags) & XFS_ATTR_NSP_ONDISK_MASK) | |
139 | #define XFS_ATTR_NSP_ARGS(flags) ((flags) & XFS_ATTR_NSP_ARGS_MASK) | |
140 | #define XFS_ATTR_NSP_ARGS_TO_ONDISK(x) (((x) & ATTR_ROOT ? XFS_ATTR_ROOT : 0) |\ | |
141 | ((x) & ATTR_SECURE ? XFS_ATTR_SECURE : 0)) | |
142 | #define XFS_ATTR_NSP_ONDISK_TO_ARGS(x) (((x) & XFS_ATTR_ROOT ? ATTR_ROOT : 0) |\ | |
143 | ((x) & XFS_ATTR_SECURE ? ATTR_SECURE : 0)) | |
144 | ||
1da177e4 LT |
145 | /* |
146 | * Alignment for namelist and valuelist entries (since they are mixed | |
147 | * there can be only one alignment value) | |
148 | */ | |
149 | #define XFS_ATTR_LEAF_NAME_ALIGN ((uint)sizeof(xfs_dablk_t)) | |
150 | ||
151 | /* | |
152 | * Cast typed pointers for "local" and "remote" name/value structs. | |
153 | */ | |
1da177e4 LT |
154 | #define XFS_ATTR_LEAF_NAME_REMOTE(leafp,idx) \ |
155 | xfs_attr_leaf_name_remote(leafp,idx) | |
a844f451 NS |
156 | static inline xfs_attr_leaf_name_remote_t * |
157 | xfs_attr_leaf_name_remote(xfs_attr_leafblock_t *leafp, int idx) | |
158 | { | |
6b19f2d8 NS |
159 | return (xfs_attr_leaf_name_remote_t *) |
160 | &((char *)leafp)[be16_to_cpu(leafp->entries[idx].nameidx)]; | |
a844f451 NS |
161 | } |
162 | ||
1da177e4 LT |
163 | #define XFS_ATTR_LEAF_NAME_LOCAL(leafp,idx) \ |
164 | xfs_attr_leaf_name_local(leafp,idx) | |
a844f451 NS |
165 | static inline xfs_attr_leaf_name_local_t * |
166 | xfs_attr_leaf_name_local(xfs_attr_leafblock_t *leafp, int idx) | |
167 | { | |
6b19f2d8 NS |
168 | return (xfs_attr_leaf_name_local_t *) |
169 | &((char *)leafp)[be16_to_cpu(leafp->entries[idx].nameidx)]; | |
a844f451 NS |
170 | } |
171 | ||
3762ec6b NS |
172 | #define XFS_ATTR_LEAF_NAME(leafp,idx) \ |
173 | xfs_attr_leaf_name(leafp,idx) | |
a844f451 NS |
174 | static inline char *xfs_attr_leaf_name(xfs_attr_leafblock_t *leafp, int idx) |
175 | { | |
6b19f2d8 | 176 | return &((char *)leafp)[be16_to_cpu(leafp->entries[idx].nameidx)]; |
a844f451 | 177 | } |
1da177e4 LT |
178 | |
179 | /* | |
180 | * Calculate total bytes used (including trailing pad for alignment) for | |
181 | * a "local" name/value structure, a "remote" name/value structure, and | |
182 | * a pointer which might be either. | |
183 | */ | |
1da177e4 LT |
184 | #define XFS_ATTR_LEAF_ENTSIZE_REMOTE(nlen) \ |
185 | xfs_attr_leaf_entsize_remote(nlen) | |
a844f451 NS |
186 | static inline int xfs_attr_leaf_entsize_remote(int nlen) |
187 | { | |
188 | return ((uint)sizeof(xfs_attr_leaf_name_remote_t) - 1 + (nlen) + \ | |
189 | XFS_ATTR_LEAF_NAME_ALIGN - 1) & ~(XFS_ATTR_LEAF_NAME_ALIGN - 1); | |
190 | } | |
191 | ||
1da177e4 LT |
192 | #define XFS_ATTR_LEAF_ENTSIZE_LOCAL(nlen,vlen) \ |
193 | xfs_attr_leaf_entsize_local(nlen,vlen) | |
a844f451 NS |
194 | static inline int xfs_attr_leaf_entsize_local(int nlen, int vlen) |
195 | { | |
196 | return ((uint)sizeof(xfs_attr_leaf_name_local_t) - 1 + (nlen) + (vlen) + | |
197 | XFS_ATTR_LEAF_NAME_ALIGN - 1) & ~(XFS_ATTR_LEAF_NAME_ALIGN - 1); | |
198 | } | |
199 | ||
1da177e4 LT |
200 | #define XFS_ATTR_LEAF_ENTSIZE_LOCAL_MAX(bsize) \ |
201 | xfs_attr_leaf_entsize_local_max(bsize) | |
a844f451 NS |
202 | static inline int xfs_attr_leaf_entsize_local_max(int bsize) |
203 | { | |
204 | return (((bsize) >> 1) + ((bsize) >> 2)); | |
205 | } | |
1da177e4 LT |
206 | |
207 | ||
208 | /*======================================================================== | |
209 | * Structure used to pass context around among the routines. | |
210 | *========================================================================*/ | |
211 | ||
726801ba TS |
212 | |
213 | struct xfs_attr_list_context; | |
214 | ||
215 | typedef int (*put_listent_func_t)(struct xfs_attr_list_context *, struct attrnames *, | |
216 | char *, int, int, char *); | |
217 | ||
1da177e4 | 218 | typedef struct xfs_attr_list_context { |
726801ba TS |
219 | struct xfs_inode *dp; /* inode */ |
220 | struct attrlist_cursor_kern *cursor; /* position in list */ | |
221 | struct attrlist *alist; /* output buffer */ | |
222 | int seen_enough; /* T/F: seen enough of list? */ | |
223 | int count; /* num used entries */ | |
224 | int dupcnt; /* count dup hashvals seen */ | |
225 | int bufsize; /* total buffer size */ | |
226 | int firstu; /* first used byte in buffer */ | |
227 | int flags; /* from VOP call */ | |
228 | int resynch; /* T/F: resynch with cursor */ | |
229 | int put_value; /* T/F: need value for listent */ | |
230 | put_listent_func_t put_listent; /* list output fmt function */ | |
231 | int index; /* index into output buffer */ | |
1da177e4 LT |
232 | } xfs_attr_list_context_t; |
233 | ||
234 | /* | |
235 | * Used to keep a list of "remote value" extents when unlinking an inode. | |
236 | */ | |
237 | typedef struct xfs_attr_inactive_list { | |
238 | xfs_dablk_t valueblk; /* block number of value bytes */ | |
239 | int valuelen; /* number of bytes in value */ | |
240 | } xfs_attr_inactive_list_t; | |
241 | ||
242 | ||
243 | /*======================================================================== | |
244 | * Function prototypes for the kernel. | |
245 | *========================================================================*/ | |
246 | ||
247 | /* | |
d8cc890d | 248 | * Internal routines when attribute fork size < XFS_LITINO(mp). |
1da177e4 | 249 | */ |
d8cc890d NS |
250 | void xfs_attr_shortform_create(struct xfs_da_args *args); |
251 | void xfs_attr_shortform_add(struct xfs_da_args *args, int forkoff); | |
1da177e4 LT |
252 | int xfs_attr_shortform_lookup(struct xfs_da_args *args); |
253 | int xfs_attr_shortform_getvalue(struct xfs_da_args *args); | |
254 | int xfs_attr_shortform_to_leaf(struct xfs_da_args *args); | |
d8cc890d | 255 | int xfs_attr_shortform_remove(struct xfs_da_args *args); |
1da177e4 LT |
256 | int xfs_attr_shortform_list(struct xfs_attr_list_context *context); |
257 | int xfs_attr_shortform_allfit(struct xfs_dabuf *bp, struct xfs_inode *dp); | |
d8cc890d NS |
258 | int xfs_attr_shortform_bytesfit(xfs_inode_t *dp, int bytes); |
259 | ||
1da177e4 LT |
260 | |
261 | /* | |
d8cc890d | 262 | * Internal routines when attribute fork size == XFS_LBSIZE(mp). |
1da177e4 LT |
263 | */ |
264 | int xfs_attr_leaf_to_node(struct xfs_da_args *args); | |
265 | int xfs_attr_leaf_to_shortform(struct xfs_dabuf *bp, | |
d8cc890d | 266 | struct xfs_da_args *args, int forkoff); |
1da177e4 LT |
267 | int xfs_attr_leaf_clearflag(struct xfs_da_args *args); |
268 | int xfs_attr_leaf_setflag(struct xfs_da_args *args); | |
269 | int xfs_attr_leaf_flipflags(xfs_da_args_t *args); | |
270 | ||
271 | /* | |
272 | * Routines used for growing the Btree. | |
273 | */ | |
1da177e4 LT |
274 | int xfs_attr_leaf_split(struct xfs_da_state *state, |
275 | struct xfs_da_state_blk *oldblk, | |
276 | struct xfs_da_state_blk *newblk); | |
277 | int xfs_attr_leaf_lookup_int(struct xfs_dabuf *leaf, | |
278 | struct xfs_da_args *args); | |
279 | int xfs_attr_leaf_getvalue(struct xfs_dabuf *bp, struct xfs_da_args *args); | |
280 | int xfs_attr_leaf_add(struct xfs_dabuf *leaf_buffer, | |
281 | struct xfs_da_args *args); | |
282 | int xfs_attr_leaf_remove(struct xfs_dabuf *leaf_buffer, | |
283 | struct xfs_da_args *args); | |
284 | int xfs_attr_leaf_list_int(struct xfs_dabuf *bp, | |
285 | struct xfs_attr_list_context *context); | |
286 | ||
287 | /* | |
288 | * Routines used for shrinking the Btree. | |
289 | */ | |
290 | int xfs_attr_leaf_toosmall(struct xfs_da_state *state, int *retval); | |
291 | void xfs_attr_leaf_unbalance(struct xfs_da_state *state, | |
292 | struct xfs_da_state_blk *drop_blk, | |
293 | struct xfs_da_state_blk *save_blk); | |
294 | int xfs_attr_root_inactive(struct xfs_trans **trans, struct xfs_inode *dp); | |
1da177e4 LT |
295 | |
296 | /* | |
297 | * Utility routines. | |
298 | */ | |
299 | xfs_dahash_t xfs_attr_leaf_lasthash(struct xfs_dabuf *bp, int *count); | |
300 | int xfs_attr_leaf_order(struct xfs_dabuf *leaf1_bp, | |
301 | struct xfs_dabuf *leaf2_bp); | |
aa82daa0 | 302 | int xfs_attr_leaf_newentsize(int namelen, int valuelen, int blocksize, |
1da177e4 | 303 | int *local); |
1da177e4 LT |
304 | int xfs_attr_rolltrans(struct xfs_trans **transp, struct xfs_inode *dp); |
305 | ||
306 | #endif /* __XFS_ATTR_LEAF_H__ */ |