1 /*
2 * Copyright (c) 2000,2002,2005 Silicon Graphics, Inc.
3 * All Rights Reserved.
4 *
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
7 * published by the Free Software Foundation.
8 *
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.
13 *
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
17 */
18 #ifndef __XFS_DA_BTREE_H__
19 #define __XFS_DA_BTREE_H__
20
21 struct xfs_buf;
22 struct xfs_bmap_free;
23 struct xfs_inode;
24 struct xfs_mount;
25 struct xfs_trans;
26 struct zone;
27
28 /*========================================================================
29 * Directory Structure when greater than XFS_LBSIZE(mp) bytes.
30 *========================================================================*/
31
32 /*
33 * This structure is common to both leaf nodes and non-leaf nodes in the Btree.
34 *
35 * Is is used to manage a doubly linked list of all blocks at the same
36 * level in the Btree, and to identify which type of block this is.
37 */
38 #define XFS_DA_NODE_MAGIC 0xfebe /* magic number: non-leaf blocks */
39 #define XFS_ATTR_LEAF_MAGIC 0xfbee /* magic number: attribute leaf blks */
40 #define XFS_DIR2_LEAF1_MAGIC 0xd2f1 /* magic number: v2 dirlf single blks */
41 #define XFS_DIR2_LEAFN_MAGIC 0xd2ff /* magic number: v2 dirlf multi blks */
42
43 typedef struct xfs_da_blkinfo {
44 __be32 forw; /* previous block in list */
45 __be32 back; /* following block in list */
46 __be16 magic; /* validity check on block */
47 __be16 pad; /* unused */
48 } xfs_da_blkinfo_t;
49
50 /*
51 * This is the structure of the root and intermediate nodes in the Btree.
52 * The leaf nodes are defined above.
53 *
54 * Entries are not packed.
55 *
56 * Since we have duplicate keys, use a binary search but always follow
57 * all match in the block, not just the first match found.
58 */
59 #define XFS_DA_NODE_MAXDEPTH 5 /* max depth of Btree */
60
61 typedef struct xfs_da_intnode {
62 struct xfs_da_node_hdr { /* constant-structure header block */
63 xfs_da_blkinfo_t info; /* block type, links, etc. */
64 __be16 count; /* count of active entries */
65 __be16 level; /* level above leaves (leaf == 0) */
66 } hdr;
67 struct xfs_da_node_entry {
68 __be32 hashval; /* hash value for this descendant */
69 __be32 before; /* Btree block before this key */
70 } btree[1]; /* variable sized array of keys */
71 } xfs_da_intnode_t;
72 typedef struct xfs_da_node_hdr xfs_da_node_hdr_t;
73 typedef struct xfs_da_node_entry xfs_da_node_entry_t;
74
75 #define XFS_DA_MAXHASH ((xfs_dahash_t)-1) /* largest valid hash value */
76
77 #define XFS_LBSIZE(mp) (mp)->m_sb.sb_blocksize
78 #define XFS_LBLOG(mp) (mp)->m_sb.sb_blocklog
79
80 #define XFS_DA_MAKE_BNOENTRY(mp,bno,entry) \
81 (((bno) << (mp)->m_dircook_elog) | (entry))
82 #define XFS_DA_MAKE_COOKIE(mp,bno,entry,hash) \
83 (((xfs_off_t)XFS_DA_MAKE_BNOENTRY(mp, bno, entry) << 32) | (hash))
84 #define XFS_DA_COOKIE_HASH(mp,cookie) ((xfs_dahash_t)cookie)
85 #define XFS_DA_COOKIE_BNO(mp,cookie) \
86 ((((xfs_off_t)(cookie) >> 31) == -1LL ? \
87 (xfs_dablk_t)0 : \
88 (xfs_dablk_t)((xfs_off_t)(cookie) >> \
89 ((mp)->m_dircook_elog + 32))))
90 #define XFS_DA_COOKIE_ENTRY(mp,cookie) \
91 ((((xfs_off_t)(cookie) >> 31) == -1LL ? \
92 (xfs_dablk_t)0 : \
93 (xfs_dablk_t)(((xfs_off_t)(cookie) >> 32) & \
94 ((1 << (mp)->m_dircook_elog) - 1))))
95
96
97 /*========================================================================
98 * Btree searching and modification structure definitions.
99 *========================================================================*/
100
101 /*
102 * Structure to ease passing around component names.
103 */
104 typedef struct xfs_da_args {
105 const uchar_t *name; /* string (maybe not NULL terminated) */
106 int namelen; /* length of string (maybe no NULL) */
107 uchar_t *value; /* set of bytes (maybe contain NULLs) */
108 int valuelen; /* length of value */
109 int flags; /* argument flags (eg: ATTR_NOCREATE) */
110 xfs_dahash_t hashval; /* hash value of name */
111 xfs_ino_t inumber; /* input/output inode number */
112 struct xfs_inode *dp; /* directory inode to manipulate */
113 xfs_fsblock_t *firstblock; /* ptr to firstblock for bmap calls */
114 struct xfs_bmap_free *flist; /* ptr to freelist for bmap_finish */
115 struct xfs_trans *trans; /* current trans (changes over time) */
116 xfs_extlen_t total; /* total blocks needed, for 1st bmap */
117 int whichfork; /* data or attribute fork */
118 xfs_dablk_t blkno; /* blkno of attr leaf of interest */
119 int index; /* index of attr of interest in blk */
120 xfs_dablk_t rmtblkno; /* remote attr value starting blkno */
121 int rmtblkcnt; /* remote attr value block count */
122 xfs_dablk_t blkno2; /* blkno of 2nd attr leaf of interest */
123 int index2; /* index of 2nd attr in blk */
124 xfs_dablk_t rmtblkno2; /* remote attr value starting blkno */
125 int rmtblkcnt2; /* remote attr value block count */
126 unsigned char justcheck; /* T/F: check for ok with no space */
127 unsigned char rename; /* T/F: this is an atomic rename op */
128 unsigned char addname; /* T/F: this is an add operation */
129 unsigned char oknoent; /* T/F: ok to return ENOENT, else die */
130 } xfs_da_args_t;
131
132 /*
133 * Structure to describe buffer(s) for a block.
134 * This is needed in the directory version 2 format case, when
135 * multiple non-contiguous fsblocks might be needed to cover one
136 * logical directory block.
137 * If the buffer count is 1 then the data pointer points to the
138 * same place as the b_addr field for the buffer, else to kmem_alloced memory.
139 */
140 typedef struct xfs_dabuf {
141 int nbuf; /* number of buffer pointers present */
142 short dirty; /* data needs to be copied back */
143 short bbcount; /* how large is data in bbs */
144 void *data; /* pointer for buffers' data */
145 #ifdef XFS_DABUF_DEBUG
146 inst_t *ra; /* return address of caller to make */
147 struct xfs_dabuf *next; /* next in global chain */
148 struct xfs_dabuf *prev; /* previous in global chain */
149 struct xfs_buftarg *target; /* device for buffer */
150 xfs_daddr_t blkno; /* daddr first in bps[0] */
151 #endif
152 struct xfs_buf *bps[1]; /* actually nbuf of these */
153 } xfs_dabuf_t;
154 #define XFS_DA_BUF_SIZE(n) \
155 (sizeof(xfs_dabuf_t) + sizeof(struct xfs_buf *) * ((n) - 1))
156
157 #ifdef XFS_DABUF_DEBUG
158 extern xfs_dabuf_t *xfs_dabuf_global_list;
159 #endif
160
161 /*
162 * Storage for holding state during Btree searches and split/join ops.
163 *
164 * Only need space for 5 intermediate nodes. With a minimum of 62-way
165 * fanout to the Btree, we can support over 900 million directory blocks,
166 * which is slightly more than enough.
167 */
168 typedef struct xfs_da_state_blk {
169 xfs_dabuf_t *bp; /* buffer containing block */
170 xfs_dablk_t blkno; /* filesystem blkno of buffer */
171 xfs_daddr_t disk_blkno; /* on-disk blkno (in BBs) of buffer */
172 int index; /* relevant index into block */
173 xfs_dahash_t hashval; /* last hash value in block */
174 int magic; /* blk's magic number, ie: blk type */
175 } xfs_da_state_blk_t;
176
177 typedef struct xfs_da_state_path {
178 int active; /* number of active levels */
179 xfs_da_state_blk_t blk[XFS_DA_NODE_MAXDEPTH];
180 } xfs_da_state_path_t;
181
182 typedef struct xfs_da_state {
183 xfs_da_args_t *args; /* filename arguments */
184 struct xfs_mount *mp; /* filesystem mount point */
185 unsigned int blocksize; /* logical block size */
186 unsigned int node_ents; /* how many entries in danode */
187 xfs_da_state_path_t path; /* search/split paths */
188 xfs_da_state_path_t altpath; /* alternate path for join */
189 unsigned char inleaf; /* insert into 1->lf, 0->splf */
190 unsigned char extravalid; /* T/F: extrablk is in use */
191 unsigned char extraafter; /* T/F: extrablk is after new */
192 xfs_da_state_blk_t extrablk; /* for double-splits on leafs */
193 /* for dirv2 extrablk is data */
194 } xfs_da_state_t;
195
196 /*
197 * Utility macros to aid in logging changed structure fields.
198 */
199 #define XFS_DA_LOGOFF(BASE, ADDR) ((char *)(ADDR) - (char *)(BASE))
200 #define XFS_DA_LOGRANGE(BASE, ADDR, SIZE) \
201 (uint)(XFS_DA_LOGOFF(BASE, ADDR)), \
202 (uint)(XFS_DA_LOGOFF(BASE, ADDR)+(SIZE)-1)
203
204
205 #ifdef __KERNEL__
206 /*========================================================================
207 * Function prototypes for the kernel.
208 *========================================================================*/
209
210 /*
211 * Routines used for growing the Btree.
212 */
213 int xfs_da_node_create(xfs_da_args_t *args, xfs_dablk_t blkno, int level,
214 xfs_dabuf_t **bpp, int whichfork);
215 int xfs_da_split(xfs_da_state_t *state);
216
217 /*
218 * Routines used for shrinking the Btree.
219 */
220 int xfs_da_join(xfs_da_state_t *state);
221 void xfs_da_fixhashpath(xfs_da_state_t *state,
222 xfs_da_state_path_t *path_to_to_fix);
223
224 /*
225 * Routines used for finding things in the Btree.
226 */
227 int xfs_da_node_lookup_int(xfs_da_state_t *state, int *result);
228 int xfs_da_path_shift(xfs_da_state_t *state, xfs_da_state_path_t *path,
229 int forward, int release, int *result);
230 /*
231 * Utility routines.
232 */
233 int xfs_da_blk_link(xfs_da_state_t *state, xfs_da_state_blk_t *old_blk,
234 xfs_da_state_blk_t *new_blk);
235
236 /*
237 * Utility routines.
238 */
239 int xfs_da_grow_inode(xfs_da_args_t *args, xfs_dablk_t *new_blkno);
240 int xfs_da_get_buf(struct xfs_trans *trans, struct xfs_inode *dp,
241 xfs_dablk_t bno, xfs_daddr_t mappedbno,
242 xfs_dabuf_t **bp, int whichfork);
243 int xfs_da_read_buf(struct xfs_trans *trans, struct xfs_inode *dp,
244 xfs_dablk_t bno, xfs_daddr_t mappedbno,
245 xfs_dabuf_t **bpp, int whichfork);
246 xfs_daddr_t xfs_da_reada_buf(struct xfs_trans *trans, struct xfs_inode *dp,
247 xfs_dablk_t bno, int whichfork);
248 int xfs_da_shrink_inode(xfs_da_args_t *args, xfs_dablk_t dead_blkno,
249 xfs_dabuf_t *dead_buf);
250
251 uint xfs_da_hashname(const uchar_t *name_string, int name_length);
252 xfs_da_state_t *xfs_da_state_alloc(void);
253 void xfs_da_state_free(xfs_da_state_t *state);
254
255 void xfs_da_buf_done(xfs_dabuf_t *dabuf);
256 void xfs_da_log_buf(struct xfs_trans *tp, xfs_dabuf_t *dabuf, uint first,
257 uint last);
258 void xfs_da_brelse(struct xfs_trans *tp, xfs_dabuf_t *dabuf);
259 void xfs_da_binval(struct xfs_trans *tp, xfs_dabuf_t *dabuf);
260 xfs_daddr_t xfs_da_blkno(xfs_dabuf_t *dabuf);
261
262 extern struct kmem_zone *xfs_da_state_zone;
263 extern struct kmem_zone *xfs_dabuf_zone;
264 #endif /* __KERNEL__ */
265
266 #endif /* __XFS_DA_BTREE_H__ */
267
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