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
10struct xfs_inode;
11struct xfs_trans;
12
13/*
14 * Directory/attribute geometry information. There will be one of these for each
15 * data fork type, and it will be passed around via the xfs_da_args. Global
16 * structures will be attached to the xfs_mount.
17 */
18struct xfs_da_geometry {
19 unsigned int blksize; /* da block size in bytes */
20 unsigned int fsbcount; /* da block size in filesystem blocks */
21 uint8_t fsblog; /* log2 of _filesystem_ block size */
22 uint8_t blklog; /* log2 of da block size */
23 unsigned int node_hdr_size; /* danode header size in bytes */
24 unsigned int node_ents; /* # of entries in a danode */
25 unsigned int magicpct; /* 37% of block size in bytes */
26 xfs_dablk_t datablk; /* blockno of dir data v2 */
27 unsigned int leaf_hdr_size; /* dir2 leaf header size */
28 unsigned int leaf_max_ents; /* # of entries in dir2 leaf */
29 xfs_dablk_t leafblk; /* blockno of leaf data v2 */
30 unsigned int free_hdr_size; /* dir2 free header size */
31 unsigned int free_max_bests; /* # of bests entries in dir2 free */
32 xfs_dablk_t freeblk; /* blockno of free data v2 */
33 xfs_extnum_t max_extents; /* Max. extents in corresponding fork */
34
35 xfs_dir2_data_aoff_t data_first_offset;
36 size_t data_entry_offset;
37};
38
39/*========================================================================
40 * Btree searching and modification structure definitions.
41 *========================================================================*/
42
43/*
44 * Search comparison results
45 */
46enum xfs_dacmp {
47 XFS_CMP_DIFFERENT, /* names are completely different */
48 XFS_CMP_EXACT, /* names are exactly the same */
49 XFS_CMP_CASE /* names are same but differ in case */
50};
51
52/*
53 * Structure to ease passing around component names.
54 */
55typedef struct xfs_da_args {
56 struct xfs_da_geometry *geo; /* da block geometry */
57 const uint8_t *name; /* string (maybe not NULL terminated) */
58 int namelen; /* length of string (maybe no NULL) */
59 uint8_t filetype; /* filetype of inode for directories */
60 void *value; /* set of bytes (maybe contain NULLs) */
61 int valuelen; /* length of value */
62 unsigned int attr_filter; /* XFS_ATTR_{ROOT,SECURE,INCOMPLETE} */
63 unsigned int attr_flags; /* XATTR_{CREATE,REPLACE} */
64 xfs_dahash_t hashval; /* hash value of name */
65 xfs_ino_t inumber; /* input/output inode number */
66 struct xfs_inode *dp; /* directory inode to manipulate */
67 struct xfs_trans *trans; /* current trans (changes over time) */
68 xfs_extlen_t total; /* total blocks needed, for 1st bmap */
69 int whichfork; /* data or attribute fork */
70 xfs_dablk_t blkno; /* blkno of attr leaf of interest */
71 int index; /* index of attr of interest in blk */
72 xfs_dablk_t rmtblkno; /* remote attr value starting blkno */
73 int rmtblkcnt; /* remote attr value block count */
74 int rmtvaluelen; /* remote attr value length in bytes */
75 xfs_dablk_t blkno2; /* blkno of 2nd attr leaf of interest */
76 int index2; /* index of 2nd attr in blk */
77 xfs_dablk_t rmtblkno2; /* remote attr value starting blkno */
78 int rmtblkcnt2; /* remote attr value block count */
79 int rmtvaluelen2; /* remote attr value length in bytes */
80 uint32_t op_flags; /* operation flags */
81 enum xfs_dacmp cmpresult; /* name compare result for lookups */
82} xfs_da_args_t;
83
84/*
85 * Operation flags:
86 */
87#define XFS_DA_OP_JUSTCHECK (1u << 0) /* check for ok with no space */
88#define XFS_DA_OP_REPLACE (1u << 1) /* this is an atomic replace op */
89#define XFS_DA_OP_ADDNAME (1u << 2) /* this is an add operation */
90#define XFS_DA_OP_OKNOENT (1u << 3) /* lookup op, ENOENT ok, else die */
91#define XFS_DA_OP_CILOOKUP (1u << 4) /* lookup returns CI name if found */
92#define XFS_DA_OP_NOTIME (1u << 5) /* don't update inode timestamps */
93#define XFS_DA_OP_REMOVE (1u << 6) /* this is a remove operation */
94#define XFS_DA_OP_RECOVERY (1u << 7) /* Log recovery operation */
95#define XFS_DA_OP_LOGGED (1u << 8) /* Use intent items to track op */
96
97#define XFS_DA_OP_FLAGS \
98 { XFS_DA_OP_JUSTCHECK, "JUSTCHECK" }, \
99 { XFS_DA_OP_REPLACE, "REPLACE" }, \
100 { XFS_DA_OP_ADDNAME, "ADDNAME" }, \
101 { XFS_DA_OP_OKNOENT, "OKNOENT" }, \
102 { XFS_DA_OP_CILOOKUP, "CILOOKUP" }, \
103 { XFS_DA_OP_NOTIME, "NOTIME" }, \
104 { XFS_DA_OP_REMOVE, "REMOVE" }, \
105 { XFS_DA_OP_RECOVERY, "RECOVERY" }, \
106 { XFS_DA_OP_LOGGED, "LOGGED" }
107
108/*
109 * Storage for holding state during Btree searches and split/join ops.
110 *
111 * Only need space for 5 intermediate nodes. With a minimum of 62-way
112 * fanout to the Btree, we can support over 900 million directory blocks,
113 * which is slightly more than enough.
114 */
115typedef struct xfs_da_state_blk {
116 struct xfs_buf *bp; /* buffer containing block */
117 xfs_dablk_t blkno; /* filesystem blkno of buffer */
118 xfs_daddr_t disk_blkno; /* on-disk blkno (in BBs) of buffer */
119 int index; /* relevant index into block */
120 xfs_dahash_t hashval; /* last hash value in block */
121 int magic; /* blk's magic number, ie: blk type */
122} xfs_da_state_blk_t;
123
124typedef struct xfs_da_state_path {
125 int active; /* number of active levels */
126 xfs_da_state_blk_t blk[XFS_DA_NODE_MAXDEPTH];
127} xfs_da_state_path_t;
128
129typedef struct xfs_da_state {
130 xfs_da_args_t *args; /* filename arguments */
131 struct xfs_mount *mp; /* filesystem mount point */
132 xfs_da_state_path_t path; /* search/split paths */
133 xfs_da_state_path_t altpath; /* alternate path for join */
134 unsigned char inleaf; /* insert into 1->lf, 0->splf */
135 unsigned char extravalid; /* T/F: extrablk is in use */
136 unsigned char extraafter; /* T/F: extrablk is after new */
137 xfs_da_state_blk_t extrablk; /* for double-splits on leaves */
138 /* for dirv2 extrablk is data */
139} xfs_da_state_t;
140
141/*
142 * In-core version of the node header to abstract the differences in the v2 and
143 * v3 disk format of the headers. Callers need to convert to/from disk format as
144 * appropriate.
145 */
146struct xfs_da3_icnode_hdr {
147 uint32_t forw;
148 uint32_t back;
149 uint16_t magic;
150 uint16_t count;
151 uint16_t level;
152
153 /*
154 * Pointer to the on-disk format entries, which are behind the
155 * variable size (v4 vs v5) header in the on-disk block.
156 */
157 struct xfs_da_node_entry *btree;
158};
159
160/*
161 * Utility macros to aid in logging changed structure fields.
162 */
163#define XFS_DA_LOGOFF(BASE, ADDR) ((char *)(ADDR) - (char *)(BASE))
164#define XFS_DA_LOGRANGE(BASE, ADDR, SIZE) \
165 (uint)(XFS_DA_LOGOFF(BASE, ADDR)), \
166 (uint)(XFS_DA_LOGOFF(BASE, ADDR)+(SIZE)-1)
167
168/*========================================================================
169 * Function prototypes.
170 *========================================================================*/
171
172/*
173 * Routines used for growing the Btree.
174 */
175int xfs_da3_node_create(struct xfs_da_args *args, xfs_dablk_t blkno,
176 int level, struct xfs_buf **bpp, int whichfork);
177int xfs_da3_split(xfs_da_state_t *state);
178
179/*
180 * Routines used for shrinking the Btree.
181 */
182int xfs_da3_join(xfs_da_state_t *state);
183void xfs_da3_fixhashpath(struct xfs_da_state *state,
184 struct xfs_da_state_path *path_to_to_fix);
185
186/*
187 * Routines used for finding things in the Btree.
188 */
189int xfs_da3_node_lookup_int(xfs_da_state_t *state, int *result);
190int xfs_da3_path_shift(xfs_da_state_t *state, xfs_da_state_path_t *path,
191 int forward, int release, int *result);
192/*
193 * Utility routines.
194 */
195int xfs_da3_blk_link(xfs_da_state_t *state, xfs_da_state_blk_t *old_blk,
196 xfs_da_state_blk_t *new_blk);
197int xfs_da3_node_read(struct xfs_trans *tp, struct xfs_inode *dp,
198 xfs_dablk_t bno, struct xfs_buf **bpp, int whichfork);
199int xfs_da3_node_read_mapped(struct xfs_trans *tp, struct xfs_inode *dp,
200 xfs_daddr_t mappedbno, struct xfs_buf **bpp,
201 int whichfork);
202
203/*
204 * Utility routines.
205 */
206
207#define XFS_DABUF_MAP_HOLE_OK (1u << 0)
208
209int xfs_da_grow_inode(xfs_da_args_t *args, xfs_dablk_t *new_blkno);
210int xfs_da_grow_inode_int(struct xfs_da_args *args, xfs_fileoff_t *bno,
211 int count);
212int xfs_da_get_buf(struct xfs_trans *trans, struct xfs_inode *dp,
213 xfs_dablk_t bno, struct xfs_buf **bp, int whichfork);
214int xfs_da_read_buf(struct xfs_trans *trans, struct xfs_inode *dp,
215 xfs_dablk_t bno, unsigned int flags, struct xfs_buf **bpp,
216 int whichfork, const struct xfs_buf_ops *ops);
217int xfs_da_reada_buf(struct xfs_inode *dp, xfs_dablk_t bno,
218 unsigned int flags, int whichfork,
219 const struct xfs_buf_ops *ops);
220int xfs_da_shrink_inode(xfs_da_args_t *args, xfs_dablk_t dead_blkno,
221 struct xfs_buf *dead_buf);
222void xfs_da_buf_copy(struct xfs_buf *dst, struct xfs_buf *src,
223 size_t size);
224
225uint xfs_da_hashname(const uint8_t *name_string, int name_length);
226enum xfs_dacmp xfs_da_compname(struct xfs_da_args *args,
227 const unsigned char *name, int len);
228
229
230struct xfs_da_state *xfs_da_state_alloc(struct xfs_da_args *args);
231void xfs_da_state_free(xfs_da_state_t *state);
232void xfs_da_state_reset(struct xfs_da_state *state, struct xfs_da_args *args);
233
234void xfs_da3_node_hdr_from_disk(struct xfs_mount *mp,
235 struct xfs_da3_icnode_hdr *to, struct xfs_da_intnode *from);
236void xfs_da3_node_hdr_to_disk(struct xfs_mount *mp,
237 struct xfs_da_intnode *to, struct xfs_da3_icnode_hdr *from);
238
239extern struct kmem_cache *xfs_da_state_cache;
240
241#endif /* __XFS_DA_BTREE_H__ */
242

source code of linux/fs/xfs/libxfs/xfs_da_btree.h