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1da177e4 | 1 | /* |
7b718769 | 2 | * Copyright (c) 2000,2002-2003,2005 Silicon Graphics, Inc. |
517c2220 | 3 | * Copyright (c) 2013 Red Hat, Inc. |
aa82daa0 | 4 | * All Rights Reserved. |
1da177e4 | 5 | * |
7b718769 NS |
6 | * This program is free software; you can redistribute it and/or |
7 | * modify it under the terms of the GNU General Public License as | |
1da177e4 LT |
8 | * published by the Free Software Foundation. |
9 | * | |
7b718769 NS |
10 | * This program is distributed in the hope that it would be useful, |
11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
13 | * GNU General Public License for more details. | |
1da177e4 | 14 | * |
7b718769 NS |
15 | * You should have received a copy of the GNU General Public License |
16 | * along with this program; if not, write the Free Software Foundation, | |
17 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA | |
1da177e4 LT |
18 | */ |
19 | #ifndef __XFS_ATTR_LEAF_H__ | |
20 | #define __XFS_ATTR_LEAF_H__ | |
21 | ||
22 | /* | |
23 | * Attribute storage layout, internal structure, access macros, etc. | |
24 | * | |
25 | * Attribute lists are structured around Btrees where all the data | |
26 | * elements are in the leaf nodes. Attribute names are hashed into an int, | |
27 | * then that int is used as the index into the Btree. Since the hashval | |
28 | * of an attribute name may not be unique, we may have duplicate keys. The | |
29 | * internal links in the Btree are logical block offsets into the file. | |
30 | */ | |
31 | ||
32 | struct attrlist; | |
33 | struct attrlist_cursor_kern; | |
ad9b463a | 34 | struct xfs_attr_list_context; |
1da177e4 LT |
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 | 92 | __be32 hashval; /* hash value of name */ |
517c2220 | 93 | __be16 nameidx; /* index into buffer of name/value */ |
6b19f2d8 NS |
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 | 117 | |
517c2220 DC |
118 | /* |
119 | * CRC enabled leaf structures. Called "version 3" structures to match the | |
120 | * version number of the directory and dablk structures for this feature, and | |
121 | * attr2 is already taken by the variable inode attribute fork size feature. | |
122 | */ | |
123 | struct xfs_attr3_leaf_hdr { | |
124 | struct xfs_da3_blkinfo info; | |
125 | __be16 count; | |
126 | __be16 usedbytes; | |
127 | __be16 firstused; | |
128 | __u8 holes; | |
129 | __u8 pad1; | |
130 | struct xfs_attr_leaf_map freemap[XFS_ATTR_LEAF_MAPSIZE]; | |
5170711d | 131 | __be32 pad2; /* 64 bit alignment */ |
517c2220 DC |
132 | }; |
133 | ||
134 | #define XFS_ATTR3_LEAF_CRC_OFF (offsetof(struct xfs_attr3_leaf_hdr, info.crc)) | |
135 | ||
136 | struct xfs_attr3_leafblock { | |
137 | struct xfs_attr3_leaf_hdr hdr; | |
138 | struct xfs_attr_leaf_entry entries[1]; | |
139 | ||
140 | /* | |
141 | * The rest of the block contains the following structures after the | |
142 | * leaf entries, growing from the bottom up. The variables are never | |
143 | * referenced, the locations accessed purely from helper functions. | |
144 | * | |
145 | * struct xfs_attr_leaf_name_local | |
146 | * struct xfs_attr_leaf_name_remote | |
147 | */ | |
148 | }; | |
149 | ||
150 | /* | |
151 | * incore, neutral version of the attribute leaf header | |
152 | */ | |
153 | struct xfs_attr3_icleaf_hdr { | |
154 | __uint32_t forw; | |
155 | __uint32_t back; | |
156 | __uint16_t magic; | |
157 | __uint16_t count; | |
158 | __uint16_t usedbytes; | |
159 | __uint16_t firstused; | |
160 | __u8 holes; | |
161 | struct { | |
162 | __uint16_t base; | |
163 | __uint16_t size; | |
164 | } freemap[XFS_ATTR_LEAF_MAPSIZE]; | |
165 | }; | |
166 | ||
1da177e4 LT |
167 | /* |
168 | * Flags used in the leaf_entry[i].flags field. | |
169 | * NOTE: the INCOMPLETE bit must not collide with the flags bits specified | |
170 | * on the system call, they are "or"ed together for various operations. | |
171 | */ | |
172 | #define XFS_ATTR_LOCAL_BIT 0 /* attr is stored locally */ | |
173 | #define XFS_ATTR_ROOT_BIT 1 /* limit access to trusted attrs */ | |
174 | #define XFS_ATTR_SECURE_BIT 2 /* limit access to secure attrs */ | |
175 | #define XFS_ATTR_INCOMPLETE_BIT 7 /* attr in middle of create/delete */ | |
176 | #define XFS_ATTR_LOCAL (1 << XFS_ATTR_LOCAL_BIT) | |
177 | #define XFS_ATTR_ROOT (1 << XFS_ATTR_ROOT_BIT) | |
178 | #define XFS_ATTR_SECURE (1 << XFS_ATTR_SECURE_BIT) | |
179 | #define XFS_ATTR_INCOMPLETE (1 << XFS_ATTR_INCOMPLETE_BIT) | |
180 | ||
726801ba TS |
181 | /* |
182 | * Conversion macros for converting namespace bits from argument flags | |
183 | * to ondisk flags. | |
184 | */ | |
185 | #define XFS_ATTR_NSP_ARGS_MASK (ATTR_ROOT | ATTR_SECURE) | |
186 | #define XFS_ATTR_NSP_ONDISK_MASK (XFS_ATTR_ROOT | XFS_ATTR_SECURE) | |
187 | #define XFS_ATTR_NSP_ONDISK(flags) ((flags) & XFS_ATTR_NSP_ONDISK_MASK) | |
188 | #define XFS_ATTR_NSP_ARGS(flags) ((flags) & XFS_ATTR_NSP_ARGS_MASK) | |
189 | #define XFS_ATTR_NSP_ARGS_TO_ONDISK(x) (((x) & ATTR_ROOT ? XFS_ATTR_ROOT : 0) |\ | |
190 | ((x) & ATTR_SECURE ? XFS_ATTR_SECURE : 0)) | |
191 | #define XFS_ATTR_NSP_ONDISK_TO_ARGS(x) (((x) & XFS_ATTR_ROOT ? ATTR_ROOT : 0) |\ | |
192 | ((x) & XFS_ATTR_SECURE ? ATTR_SECURE : 0)) | |
193 | ||
1da177e4 LT |
194 | /* |
195 | * Alignment for namelist and valuelist entries (since they are mixed | |
196 | * there can be only one alignment value) | |
197 | */ | |
198 | #define XFS_ATTR_LEAF_NAME_ALIGN ((uint)sizeof(xfs_dablk_t)) | |
199 | ||
517c2220 DC |
200 | static inline int |
201 | xfs_attr3_leaf_hdr_size(struct xfs_attr_leafblock *leafp) | |
202 | { | |
203 | if (leafp->hdr.info.magic == cpu_to_be16(XFS_ATTR3_LEAF_MAGIC)) | |
204 | return sizeof(struct xfs_attr3_leaf_hdr); | |
205 | return sizeof(struct xfs_attr_leaf_hdr); | |
206 | } | |
207 | ||
208 | static inline struct xfs_attr_leaf_entry * | |
209 | xfs_attr3_leaf_entryp(xfs_attr_leafblock_t *leafp) | |
210 | { | |
211 | if (leafp->hdr.info.magic == cpu_to_be16(XFS_ATTR3_LEAF_MAGIC)) | |
212 | return &((struct xfs_attr3_leafblock *)leafp)->entries[0]; | |
213 | return &leafp->entries[0]; | |
214 | } | |
215 | ||
1da177e4 LT |
216 | /* |
217 | * Cast typed pointers for "local" and "remote" name/value structs. | |
218 | */ | |
517c2220 DC |
219 | static inline char * |
220 | xfs_attr3_leaf_name(xfs_attr_leafblock_t *leafp, int idx) | |
a844f451 | 221 | { |
517c2220 DC |
222 | struct xfs_attr_leaf_entry *entries = xfs_attr3_leaf_entryp(leafp); |
223 | ||
224 | return &((char *)leafp)[be16_to_cpu(entries[idx].nameidx)]; | |
a844f451 NS |
225 | } |
226 | ||
517c2220 DC |
227 | static inline xfs_attr_leaf_name_remote_t * |
228 | xfs_attr3_leaf_name_remote(xfs_attr_leafblock_t *leafp, int idx) | |
a844f451 | 229 | { |
517c2220 | 230 | return (xfs_attr_leaf_name_remote_t *)xfs_attr3_leaf_name(leafp, idx); |
a844f451 NS |
231 | } |
232 | ||
517c2220 DC |
233 | static inline xfs_attr_leaf_name_local_t * |
234 | xfs_attr3_leaf_name_local(xfs_attr_leafblock_t *leafp, int idx) | |
a844f451 | 235 | { |
517c2220 | 236 | return (xfs_attr_leaf_name_local_t *)xfs_attr3_leaf_name(leafp, idx); |
a844f451 | 237 | } |
1da177e4 LT |
238 | |
239 | /* | |
240 | * Calculate total bytes used (including trailing pad for alignment) for | |
241 | * a "local" name/value structure, a "remote" name/value structure, and | |
242 | * a pointer which might be either. | |
243 | */ | |
a844f451 NS |
244 | static inline int xfs_attr_leaf_entsize_remote(int nlen) |
245 | { | |
246 | return ((uint)sizeof(xfs_attr_leaf_name_remote_t) - 1 + (nlen) + \ | |
247 | XFS_ATTR_LEAF_NAME_ALIGN - 1) & ~(XFS_ATTR_LEAF_NAME_ALIGN - 1); | |
248 | } | |
249 | ||
a844f451 NS |
250 | static inline int xfs_attr_leaf_entsize_local(int nlen, int vlen) |
251 | { | |
252 | return ((uint)sizeof(xfs_attr_leaf_name_local_t) - 1 + (nlen) + (vlen) + | |
253 | XFS_ATTR_LEAF_NAME_ALIGN - 1) & ~(XFS_ATTR_LEAF_NAME_ALIGN - 1); | |
254 | } | |
255 | ||
a844f451 NS |
256 | static inline int xfs_attr_leaf_entsize_local_max(int bsize) |
257 | { | |
258 | return (((bsize) >> 1) + ((bsize) >> 2)); | |
259 | } | |
1da177e4 | 260 | |
1da177e4 LT |
261 | /* |
262 | * Used to keep a list of "remote value" extents when unlinking an inode. | |
263 | */ | |
264 | typedef struct xfs_attr_inactive_list { | |
265 | xfs_dablk_t valueblk; /* block number of value bytes */ | |
266 | int valuelen; /* number of bytes in value */ | |
267 | } xfs_attr_inactive_list_t; | |
268 | ||
269 | ||
270 | /*======================================================================== | |
271 | * Function prototypes for the kernel. | |
272 | *========================================================================*/ | |
273 | ||
274 | /* | |
d8cc890d | 275 | * Internal routines when attribute fork size < XFS_LITINO(mp). |
1da177e4 | 276 | */ |
d8cc890d NS |
277 | void xfs_attr_shortform_create(struct xfs_da_args *args); |
278 | void xfs_attr_shortform_add(struct xfs_da_args *args, int forkoff); | |
1da177e4 LT |
279 | int xfs_attr_shortform_lookup(struct xfs_da_args *args); |
280 | int xfs_attr_shortform_getvalue(struct xfs_da_args *args); | |
281 | int xfs_attr_shortform_to_leaf(struct xfs_da_args *args); | |
d8cc890d | 282 | int xfs_attr_shortform_remove(struct xfs_da_args *args); |
1da177e4 | 283 | int xfs_attr_shortform_list(struct xfs_attr_list_context *context); |
1d9025e5 | 284 | int xfs_attr_shortform_allfit(struct xfs_buf *bp, struct xfs_inode *dp); |
d8cc890d NS |
285 | int xfs_attr_shortform_bytesfit(xfs_inode_t *dp, int bytes); |
286 | ||
1da177e4 LT |
287 | |
288 | /* | |
d8cc890d | 289 | * Internal routines when attribute fork size == XFS_LBSIZE(mp). |
1da177e4 | 290 | */ |
517c2220 DC |
291 | int xfs_attr3_leaf_to_node(struct xfs_da_args *args); |
292 | int xfs_attr3_leaf_to_shortform(struct xfs_buf *bp, | |
d8cc890d | 293 | struct xfs_da_args *args, int forkoff); |
517c2220 DC |
294 | int xfs_attr3_leaf_clearflag(struct xfs_da_args *args); |
295 | int xfs_attr3_leaf_setflag(struct xfs_da_args *args); | |
296 | int xfs_attr3_leaf_flipflags(struct xfs_da_args *args); | |
1da177e4 LT |
297 | |
298 | /* | |
299 | * Routines used for growing the Btree. | |
300 | */ | |
517c2220 | 301 | int xfs_attr3_leaf_split(struct xfs_da_state *state, |
1da177e4 LT |
302 | struct xfs_da_state_blk *oldblk, |
303 | struct xfs_da_state_blk *newblk); | |
517c2220 | 304 | int xfs_attr3_leaf_lookup_int(struct xfs_buf *leaf, |
1da177e4 | 305 | struct xfs_da_args *args); |
517c2220 DC |
306 | int xfs_attr3_leaf_getvalue(struct xfs_buf *bp, struct xfs_da_args *args); |
307 | int xfs_attr3_leaf_add(struct xfs_buf *leaf_buffer, | |
1da177e4 | 308 | struct xfs_da_args *args); |
517c2220 | 309 | int xfs_attr3_leaf_remove(struct xfs_buf *leaf_buffer, |
1da177e4 | 310 | struct xfs_da_args *args); |
517c2220 | 311 | int xfs_attr3_leaf_list_int(struct xfs_buf *bp, |
1da177e4 LT |
312 | struct xfs_attr_list_context *context); |
313 | ||
314 | /* | |
315 | * Routines used for shrinking the Btree. | |
316 | */ | |
517c2220 DC |
317 | int xfs_attr3_leaf_toosmall(struct xfs_da_state *state, int *retval); |
318 | void xfs_attr3_leaf_unbalance(struct xfs_da_state *state, | |
1da177e4 LT |
319 | struct xfs_da_state_blk *drop_blk, |
320 | struct xfs_da_state_blk *save_blk); | |
517c2220 | 321 | int xfs_attr3_root_inactive(struct xfs_trans **trans, struct xfs_inode *dp); |
1da177e4 LT |
322 | |
323 | /* | |
324 | * Utility routines. | |
325 | */ | |
1d9025e5 DC |
326 | xfs_dahash_t xfs_attr_leaf_lasthash(struct xfs_buf *bp, int *count); |
327 | int xfs_attr_leaf_order(struct xfs_buf *leaf1_bp, | |
328 | struct xfs_buf *leaf2_bp); | |
aa82daa0 | 329 | int xfs_attr_leaf_newentsize(int namelen, int valuelen, int blocksize, |
1da177e4 | 330 | int *local); |
517c2220 | 331 | int xfs_attr3_leaf_read(struct xfs_trans *tp, struct xfs_inode *dp, |
d9392a4b DC |
332 | xfs_dablk_t bno, xfs_daddr_t mappedbno, |
333 | struct xfs_buf **bpp); | |
517c2220 DC |
334 | void xfs_attr3_leaf_hdr_from_disk(struct xfs_attr3_icleaf_hdr *to, |
335 | struct xfs_attr_leafblock *from); | |
d386b32b DC |
336 | void xfs_attr3_leaf_hdr_to_disk(struct xfs_attr_leafblock *to, |
337 | struct xfs_attr3_icleaf_hdr *from); | |
1813dd64 | 338 | |
517c2220 | 339 | extern const struct xfs_buf_ops xfs_attr3_leaf_buf_ops; |
d9392a4b | 340 | |
1da177e4 | 341 | #endif /* __XFS_ATTR_LEAF_H__ */ |