1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (c) 2000,2002,2005 Silicon Graphics, Inc.
4 * Copyright (c) 2013 Red Hat, Inc.
5 * All Rights Reserved.
6 */
7 #ifndef __XFS_DA_BTREE_H__
8 #define __XFS_DA_BTREE_H__
9
10 struct xfs_inode;
11 struct xfs_trans;
12 struct zone;
13 struct xfs_dir_ops;
14
15 /*
16 * Directory/attribute geometry information. There will be one of these for each
17 * data fork type, and it will be passed around via the xfs_da_args. Global
18 * structures will be attached to the xfs_mount.
19 */
20 struct xfs_da_geometry {
21 int blksize; /* da block size in bytes */
22 int fsbcount; /* da block size in filesystem blocks */
23 uint8_t fsblog; /* log2 of _filesystem_ block size */
24 uint8_t blklog; /* log2 of da block size */
25 uint node_ents; /* # of entries in a danode */
26 int magicpct; /* 37% of block size in bytes */
27 xfs_dablk_t datablk; /* blockno of dir data v2 */
28 xfs_dablk_t leafblk; /* blockno of leaf data v2 */
29 xfs_dablk_t freeblk; /* blockno of free data v2 */
30 };
31
32 /*========================================================================
33 * Btree searching and modification structure definitions.
34 *========================================================================*/
35
36 /*
37 * Search comparison results
38 */
39 enum xfs_dacmp {
40 XFS_CMP_DIFFERENT, /* names are completely different */
41 XFS_CMP_EXACT, /* names are exactly the same */
42 XFS_CMP_CASE /* names are same but differ in case */
43 };
44
45 /*
46 * Structure to ease passing around component names.
47 */
48 typedef struct xfs_da_args {
49 struct xfs_da_geometry *geo; /* da block geometry */
50 const uint8_t *name; /* string (maybe not NULL terminated) */
51 int namelen; /* length of string (maybe no NULL) */
52 uint8_t filetype; /* filetype of inode for directories */
53 uint8_t *value; /* set of bytes (maybe contain NULLs) */
54 int valuelen; /* length of value */
55 int flags; /* argument flags (eg: ATTR_NOCREATE) */
56 xfs_dahash_t hashval; /* hash value of name */
57 xfs_ino_t inumber; /* input/output inode number */
58 struct xfs_inode *dp; /* directory inode to manipulate */
59 struct xfs_trans *trans; /* current trans (changes over time) */
60 xfs_extlen_t total; /* total blocks needed, for 1st bmap */
61 int whichfork; /* data or attribute fork */
62 xfs_dablk_t blkno; /* blkno of attr leaf of interest */
63 int index; /* index of attr of interest in blk */
64 xfs_dablk_t rmtblkno; /* remote attr value starting blkno */
65 int rmtblkcnt; /* remote attr value block count */
66 int rmtvaluelen; /* remote attr value length in bytes */
67 xfs_dablk_t blkno2; /* blkno of 2nd attr leaf of interest */
68 int index2; /* index of 2nd attr in blk */
69 xfs_dablk_t rmtblkno2; /* remote attr value starting blkno */
70 int rmtblkcnt2; /* remote attr value block count */
71 int rmtvaluelen2; /* remote attr value length in bytes */
72 int op_flags; /* operation flags */
73 enum xfs_dacmp cmpresult; /* name compare result for lookups */
74 } xfs_da_args_t;
75
76 /*
77 * Operation flags:
78 */
79 #define XFS_DA_OP_JUSTCHECK 0x0001 /* check for ok with no space */
80 #define XFS_DA_OP_RENAME 0x0002 /* this is an atomic rename op */
81 #define XFS_DA_OP_ADDNAME 0x0004 /* this is an add operation */
82 #define XFS_DA_OP_OKNOENT 0x0008 /* lookup/add op, ENOENT ok, else die */
83 #define XFS_DA_OP_CILOOKUP 0x0010 /* lookup to return CI name if found */
84 #define XFS_DA_OP_ALLOCVAL 0x0020 /* lookup to alloc buffer if found */
85
86 #define XFS_DA_OP_FLAGS \
87 { XFS_DA_OP_JUSTCHECK, "JUSTCHECK" }, \
88 { XFS_DA_OP_RENAME, "RENAME" }, \
89 { XFS_DA_OP_ADDNAME, "ADDNAME" }, \
90 { XFS_DA_OP_OKNOENT, "OKNOENT" }, \
91 { XFS_DA_OP_CILOOKUP, "CILOOKUP" }, \
92 { XFS_DA_OP_ALLOCVAL, "ALLOCVAL" }
93
94 /*
95 * Storage for holding state during Btree searches and split/join ops.
96 *
97 * Only need space for 5 intermediate nodes. With a minimum of 62-way
98 * fanout to the Btree, we can support over 900 million directory blocks,
99 * which is slightly more than enough.
100 */
101 typedef struct xfs_da_state_blk {
102 struct xfs_buf *bp; /* buffer containing block */
103 xfs_dablk_t blkno; /* filesystem blkno of buffer */
104 xfs_daddr_t disk_blkno; /* on-disk blkno (in BBs) of buffer */
105 int index; /* relevant index into block */
106 xfs_dahash_t hashval; /* last hash value in block */
107 int magic; /* blk's magic number, ie: blk type */
108 } xfs_da_state_blk_t;
109
110 typedef struct xfs_da_state_path {
111 int active; /* number of active levels */
112 xfs_da_state_blk_t blk[XFS_DA_NODE_MAXDEPTH];
113 } xfs_da_state_path_t;
114
115 typedef struct xfs_da_state {
116 xfs_da_args_t *args; /* filename arguments */
117 struct xfs_mount *mp; /* filesystem mount point */
118 xfs_da_state_path_t path; /* search/split paths */
119 xfs_da_state_path_t altpath; /* alternate path for join */
120 unsigned char inleaf; /* insert into 1->lf, 0->splf */
121 unsigned char extravalid; /* T/F: extrablk is in use */
122 unsigned char extraafter; /* T/F: extrablk is after new */
123 xfs_da_state_blk_t extrablk; /* for double-splits on leaves */
124 /* for dirv2 extrablk is data */
125 } xfs_da_state_t;
126
127 /*
128 * Utility macros to aid in logging changed structure fields.
129 */
130 #define XFS_DA_LOGOFF(BASE, ADDR) ((char *)(ADDR) - (char *)(BASE))
131 #define XFS_DA_LOGRANGE(BASE, ADDR, SIZE) \
132 (uint)(XFS_DA_LOGOFF(BASE, ADDR)), \
133 (uint)(XFS_DA_LOGOFF(BASE, ADDR)+(SIZE)-1)
134
135 /*
136 * Name ops for directory and/or attr name operations
137 */
138 struct xfs_nameops {
139 xfs_dahash_t (*hashname)(struct xfs_name *);
140 enum xfs_dacmp (*compname)(struct xfs_da_args *,
141 const unsigned char *, int);
142 };
143
144
145 /*========================================================================
146 * Function prototypes.
147 *========================================================================*/
148
149 /*
150 * Routines used for growing the Btree.
151 */
152 int xfs_da3_node_create(struct xfs_da_args *args, xfs_dablk_t blkno,
153 int level, struct xfs_buf **bpp, int whichfork);
154 int xfs_da3_split(xfs_da_state_t *state);
155
156 /*
157 * Routines used for shrinking the Btree.
158 */
159 int xfs_da3_join(xfs_da_state_t *state);
160 void xfs_da3_fixhashpath(struct xfs_da_state *state,
161 struct xfs_da_state_path *path_to_to_fix);
162
163 /*
164 * Routines used for finding things in the Btree.
165 */
166 int xfs_da3_node_lookup_int(xfs_da_state_t *state, int *result);
167 int xfs_da3_path_shift(xfs_da_state_t *state, xfs_da_state_path_t *path,
168 int forward, int release, int *result);
169 /*
170 * Utility routines.
171 */
172 int xfs_da3_blk_link(xfs_da_state_t *state, xfs_da_state_blk_t *old_blk,
173 xfs_da_state_blk_t *new_blk);
174 int xfs_da3_node_read(struct xfs_trans *tp, struct xfs_inode *dp,
175 xfs_dablk_t bno, xfs_daddr_t mappedbno,
176 struct xfs_buf **bpp, int which_fork);
177
178 /*
179 * Utility routines.
180 */
181 int xfs_da_grow_inode(xfs_da_args_t *args, xfs_dablk_t *new_blkno);
182 int xfs_da_grow_inode_int(struct xfs_da_args *args, xfs_fileoff_t *bno,
183 int count);
184 int xfs_da_get_buf(struct xfs_trans *trans, struct xfs_inode *dp,
185 xfs_dablk_t bno, xfs_daddr_t mappedbno,
186 struct xfs_buf **bp, int whichfork);
187 int xfs_da_read_buf(struct xfs_trans *trans, struct xfs_inode *dp,
188 xfs_dablk_t bno, xfs_daddr_t mappedbno,
189 struct xfs_buf **bpp, int whichfork,
190 const struct xfs_buf_ops *ops);
191 int xfs_da_reada_buf(struct xfs_inode *dp, xfs_dablk_t bno,
192 xfs_daddr_t mapped_bno, int whichfork,
193 const struct xfs_buf_ops *ops);
194 int xfs_da_shrink_inode(xfs_da_args_t *args, xfs_dablk_t dead_blkno,
195 struct xfs_buf *dead_buf);
196
197 uint xfs_da_hashname(const uint8_t *name_string, int name_length);
198 enum xfs_dacmp xfs_da_compname(struct xfs_da_args *args,
199 const unsigned char *name, int len);
200
201
202 xfs_da_state_t *xfs_da_state_alloc(void);
203 void xfs_da_state_free(xfs_da_state_t *state);
204
205 extern struct kmem_zone *xfs_da_state_zone;
206 extern const struct xfs_nameops xfs_default_nameops;
207
208 #endif /* __XFS_DA_BTREE_H__ */