1 /*
2 * Copyright (c) 2000,2002,2005 Silicon Graphics, Inc.
3 * Copyright (c) 2013 Red Hat, Inc.
4 * All Rights Reserved.
5 *
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
8 * published by the Free Software Foundation.
9 *
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.
14 *
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
18 */
19 #ifndef __XFS_DA_BTREE_H__
20 #define __XFS_DA_BTREE_H__
21
22 struct xfs_bmap_free;
23 struct xfs_inode;
24 struct xfs_trans;
25 struct zone;
26
27 /*========================================================================
28 * Directory Structure when greater than XFS_LBSIZE(mp) bytes.
29 *========================================================================*/
30
31 /*
32 * This structure is common to both leaf nodes and non-leaf nodes in the Btree.
33 *
34 * It is used to manage a doubly linked list of all blocks at the same
35 * level in the Btree, and to identify which type of block this is.
36 */
37 #define XFS_DA_NODE_MAGIC 0xfebe /* magic number: non-leaf blocks */
38 #define XFS_ATTR_LEAF_MAGIC 0xfbee /* magic number: attribute leaf blks */
39 #define XFS_DIR2_LEAF1_MAGIC 0xd2f1 /* magic number: v2 dirlf single blks */
40 #define XFS_DIR2_LEAFN_MAGIC 0xd2ff /* magic number: v2 dirlf multi blks */
41
42 typedef struct xfs_da_blkinfo {
43 __be32 forw; /* previous block in list */
44 __be32 back; /* following block in list */
45 __be16 magic; /* validity check on block */
46 __be16 pad; /* unused */
47 } xfs_da_blkinfo_t;
48
49 /*
50 * CRC enabled directory structure types
51 *
52 * The headers change size for the additional verification information, but
53 * otherwise the tree layouts and contents are unchanged. Hence the da btree
54 * code can use the struct xfs_da_blkinfo for manipulating the tree links and
55 * magic numbers without modification for both v2 and v3 nodes.
56 */
57 #define XFS_DA3_NODE_MAGIC 0x3ebe /* magic number: non-leaf blocks */
58 #define XFS_ATTR3_LEAF_MAGIC 0x3bee /* magic number: attribute leaf blks */
59 #define XFS_DIR3_LEAF1_MAGIC 0x3df1 /* magic number: v2 dirlf single blks */
60 #define XFS_DIR3_LEAFN_MAGIC 0x3dff /* magic number: v2 dirlf multi blks */
61
62 struct xfs_da3_blkinfo {
63 /*
64 * the node link manipulation code relies on the fact that the first
65 * element of this structure is the struct xfs_da_blkinfo so it can
66 * ignore the differences in the rest of the structures.
67 */
68 struct xfs_da_blkinfo hdr;
69 __be32 crc; /* CRC of block */
70 __be64 blkno; /* first block of the buffer */
71 __be64 lsn; /* sequence number of last write */
72 uuid_t uuid; /* filesystem we belong to */
73 __be64 owner; /* inode that owns the block */
74 };
75
76 /*
77 * This is the structure of the root and intermediate nodes in the Btree.
78 * The leaf nodes are defined above.
79 *
80 * Entries are not packed.
81 *
82 * Since we have duplicate keys, use a binary search but always follow
83 * all match in the block, not just the first match found.
84 */
85 #define XFS_DA_NODE_MAXDEPTH 5 /* max depth of Btree */
86
87 typedef struct xfs_da_node_hdr {
88 struct xfs_da_blkinfo info; /* block type, links, etc. */
89 __be16 __count; /* count of active entries */
90 __be16 __level; /* level above leaves (leaf == 0) */
91 } xfs_da_node_hdr_t;
92
93 struct xfs_da3_node_hdr {
94 struct xfs_da3_blkinfo info; /* block type, links, etc. */
95 __be16 __count; /* count of active entries */
96 __be16 __level; /* level above leaves (leaf == 0) */
97 __be32 __pad32;
98 };
99
100 #define XFS_DA3_NODE_CRC_OFF (offsetof(struct xfs_da3_node_hdr, info.crc))
101
102 typedef struct xfs_da_node_entry {
103 __be32 hashval; /* hash value for this descendant */
104 __be32 before; /* Btree block before this key */
105 } xfs_da_node_entry_t;
106
107 typedef struct xfs_da_intnode {
108 struct xfs_da_node_hdr hdr;
109 struct xfs_da_node_entry __btree[];
110 } xfs_da_intnode_t;
111
112 struct xfs_da3_intnode {
113 struct xfs_da3_node_hdr hdr;
114 struct xfs_da_node_entry __btree[];
115 };
116
117 /*
118 * In-core version of the node header to abstract the differences in the v2 and
119 * v3 disk format of the headers. Callers need to convert to/from disk format as
120 * appropriate.
121 */
122 struct xfs_da3_icnode_hdr {
123 __uint32_t forw;
124 __uint32_t back;
125 __uint16_t magic;
126 __uint16_t count;
127 __uint16_t level;
128 };
129
130 extern void xfs_da3_node_hdr_from_disk(struct xfs_da3_icnode_hdr *to,
131 struct xfs_da_intnode *from);
132 extern void xfs_da3_node_hdr_to_disk(struct xfs_da_intnode *to,
133 struct xfs_da3_icnode_hdr *from);
134
135 static inline int
xfs_da3_node_hdr_size(struct xfs_da_intnode * dap)136 xfs_da3_node_hdr_size(struct xfs_da_intnode *dap)
137 {
138 if (dap->hdr.info.magic == cpu_to_be16(XFS_DA3_NODE_MAGIC))
139 return sizeof(struct xfs_da3_node_hdr);
140 return sizeof(struct xfs_da_node_hdr);
141 }
142
143 static inline struct xfs_da_node_entry *
xfs_da3_node_tree_p(struct xfs_da_intnode * dap)144 xfs_da3_node_tree_p(struct xfs_da_intnode *dap)
145 {
146 if (dap->hdr.info.magic == cpu_to_be16(XFS_DA3_NODE_MAGIC)) {
147 struct xfs_da3_intnode *dap3 = (struct xfs_da3_intnode *)dap;
148 return dap3->__btree;
149 }
150 return dap->__btree;
151 }
152
153 extern void xfs_da3_intnode_from_disk(struct xfs_da3_icnode_hdr *to,
154 struct xfs_da_intnode *from);
155 extern void xfs_da3_intnode_to_disk(struct xfs_da_intnode *to,
156 struct xfs_da3_icnode_hdr *from);
157
158 #define XFS_LBSIZE(mp) (mp)->m_sb.sb_blocksize
159
160 /*========================================================================
161 * Btree searching and modification structure definitions.
162 *========================================================================*/
163
164 /*
165 * Search comparison results
166 */
167 enum xfs_dacmp {
168 XFS_CMP_DIFFERENT, /* names are completely different */
169 XFS_CMP_EXACT, /* names are exactly the same */
170 XFS_CMP_CASE /* names are same but differ in case */
171 };
172
173 /*
174 * Structure to ease passing around component names.
175 */
176 typedef struct xfs_da_args {
177 const __uint8_t *name; /* string (maybe not NULL terminated) */
178 int namelen; /* length of string (maybe no NULL) */
179 __uint8_t *value; /* set of bytes (maybe contain NULLs) */
180 int valuelen; /* length of value */
181 int flags; /* argument flags (eg: ATTR_NOCREATE) */
182 xfs_dahash_t hashval; /* hash value of name */
183 xfs_ino_t inumber; /* input/output inode number */
184 struct xfs_inode *dp; /* directory inode to manipulate */
185 xfs_fsblock_t *firstblock; /* ptr to firstblock for bmap calls */
186 struct xfs_bmap_free *flist; /* ptr to freelist for bmap_finish */
187 struct xfs_trans *trans; /* current trans (changes over time) */
188 xfs_extlen_t total; /* total blocks needed, for 1st bmap */
189 int whichfork; /* data or attribute fork */
190 xfs_dablk_t blkno; /* blkno of attr leaf of interest */
191 int index; /* index of attr of interest in blk */
192 xfs_dablk_t rmtblkno; /* remote attr value starting blkno */
193 int rmtblkcnt; /* remote attr value block count */
194 xfs_dablk_t blkno2; /* blkno of 2nd attr leaf of interest */
195 int index2; /* index of 2nd attr in blk */
196 xfs_dablk_t rmtblkno2; /* remote attr value starting blkno */
197 int rmtblkcnt2; /* remote attr value block count */
198 int op_flags; /* operation flags */
199 enum xfs_dacmp cmpresult; /* name compare result for lookups */
200 } xfs_da_args_t;
201
202 /*
203 * Operation flags:
204 */
205 #define XFS_DA_OP_JUSTCHECK 0x0001 /* check for ok with no space */
206 #define XFS_DA_OP_RENAME 0x0002 /* this is an atomic rename op */
207 #define XFS_DA_OP_ADDNAME 0x0004 /* this is an add operation */
208 #define XFS_DA_OP_OKNOENT 0x0008 /* lookup/add op, ENOENT ok, else die */
209 #define XFS_DA_OP_CILOOKUP 0x0010 /* lookup to return CI name if found */
210
211 #define XFS_DA_OP_FLAGS \
212 { XFS_DA_OP_JUSTCHECK, "JUSTCHECK" }, \
213 { XFS_DA_OP_RENAME, "RENAME" }, \
214 { XFS_DA_OP_ADDNAME, "ADDNAME" }, \
215 { XFS_DA_OP_OKNOENT, "OKNOENT" }, \
216 { XFS_DA_OP_CILOOKUP, "CILOOKUP" }
217
218 /*
219 * Storage for holding state during Btree searches and split/join ops.
220 *
221 * Only need space for 5 intermediate nodes. With a minimum of 62-way
222 * fanout to the Btree, we can support over 900 million directory blocks,
223 * which is slightly more than enough.
224 */
225 typedef struct xfs_da_state_blk {
226 struct xfs_buf *bp; /* buffer containing block */
227 xfs_dablk_t blkno; /* filesystem blkno of buffer */
228 xfs_daddr_t disk_blkno; /* on-disk blkno (in BBs) of buffer */
229 int index; /* relevant index into block */
230 xfs_dahash_t hashval; /* last hash value in block */
231 int magic; /* blk's magic number, ie: blk type */
232 } xfs_da_state_blk_t;
233
234 typedef struct xfs_da_state_path {
235 int active; /* number of active levels */
236 xfs_da_state_blk_t blk[XFS_DA_NODE_MAXDEPTH];
237 } xfs_da_state_path_t;
238
239 typedef struct xfs_da_state {
240 xfs_da_args_t *args; /* filename arguments */
241 struct xfs_mount *mp; /* filesystem mount point */
242 unsigned int blocksize; /* logical block size */
243 unsigned int node_ents; /* how many entries in danode */
244 xfs_da_state_path_t path; /* search/split paths */
245 xfs_da_state_path_t altpath; /* alternate path for join */
246 unsigned char inleaf; /* insert into 1->lf, 0->splf */
247 unsigned char extravalid; /* T/F: extrablk is in use */
248 unsigned char extraafter; /* T/F: extrablk is after new */
249 xfs_da_state_blk_t extrablk; /* for double-splits on leaves */
250 /* for dirv2 extrablk is data */
251 } xfs_da_state_t;
252
253 /*
254 * Utility macros to aid in logging changed structure fields.
255 */
256 #define XFS_DA_LOGOFF(BASE, ADDR) ((char *)(ADDR) - (char *)(BASE))
257 #define XFS_DA_LOGRANGE(BASE, ADDR, SIZE) \
258 (uint)(XFS_DA_LOGOFF(BASE, ADDR)), \
259 (uint)(XFS_DA_LOGOFF(BASE, ADDR)+(SIZE)-1)
260
261 /*
262 * Name ops for directory and/or attr name operations
263 */
264 struct xfs_nameops {
265 xfs_dahash_t (*hashname)(struct xfs_name *);
266 enum xfs_dacmp (*compname)(struct xfs_da_args *,
267 const unsigned char *, int);
268 };
269
270
271 /*========================================================================
272 * Function prototypes.
273 *========================================================================*/
274
275 /*
276 * Routines used for growing the Btree.
277 */
278 int xfs_da3_node_create(struct xfs_da_args *args, xfs_dablk_t blkno,
279 int level, struct xfs_buf **bpp, int whichfork);
280 int xfs_da3_split(xfs_da_state_t *state);
281
282 /*
283 * Routines used for shrinking the Btree.
284 */
285 int xfs_da3_join(xfs_da_state_t *state);
286 void xfs_da3_fixhashpath(struct xfs_da_state *state,
287 struct xfs_da_state_path *path_to_to_fix);
288
289 /*
290 * Routines used for finding things in the Btree.
291 */
292 int xfs_da3_node_lookup_int(xfs_da_state_t *state, int *result);
293 int xfs_da3_path_shift(xfs_da_state_t *state, xfs_da_state_path_t *path,
294 int forward, int release, int *result);
295 /*
296 * Utility routines.
297 */
298 int xfs_da3_blk_link(xfs_da_state_t *state, xfs_da_state_blk_t *old_blk,
299 xfs_da_state_blk_t *new_blk);
300 int xfs_da3_node_read(struct xfs_trans *tp, struct xfs_inode *dp,
301 xfs_dablk_t bno, xfs_daddr_t mappedbno,
302 struct xfs_buf **bpp, int which_fork);
303
304 extern const struct xfs_buf_ops xfs_da3_node_buf_ops;
305
306 /*
307 * Utility routines.
308 */
309 int xfs_da_grow_inode(xfs_da_args_t *args, xfs_dablk_t *new_blkno);
310 int xfs_da_grow_inode_int(struct xfs_da_args *args, xfs_fileoff_t *bno,
311 int count);
312 int xfs_da_get_buf(struct xfs_trans *trans, struct xfs_inode *dp,
313 xfs_dablk_t bno, xfs_daddr_t mappedbno,
314 struct xfs_buf **bp, int whichfork);
315 int xfs_da_read_buf(struct xfs_trans *trans, struct xfs_inode *dp,
316 xfs_dablk_t bno, xfs_daddr_t mappedbno,
317 struct xfs_buf **bpp, int whichfork,
318 const struct xfs_buf_ops *ops);
319 xfs_daddr_t xfs_da_reada_buf(struct xfs_trans *trans, struct xfs_inode *dp,
320 xfs_dablk_t bno, xfs_daddr_t mapped_bno,
321 int whichfork, const struct xfs_buf_ops *ops);
322 int xfs_da_shrink_inode(xfs_da_args_t *args, xfs_dablk_t dead_blkno,
323 struct xfs_buf *dead_buf);
324
325 uint xfs_da_hashname(const __uint8_t *name_string, int name_length);
326 enum xfs_dacmp xfs_da_compname(struct xfs_da_args *args,
327 const unsigned char *name, int len);
328
329
330 xfs_da_state_t *xfs_da_state_alloc(void);
331 void xfs_da_state_free(xfs_da_state_t *state);
332
333 extern struct kmem_zone *xfs_da_state_zone;
334 extern const struct xfs_nameops xfs_default_nameops;
335
336 #endif /* __XFS_DA_BTREE_H__ */
337