xref: /linux/fs/xfs/libxfs/xfs_dir2.h (revision b7019ac550eb3916f34d79db583e9b7ea2524afa)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2000-2001,2005 Silicon Graphics, Inc.
4  * All Rights Reserved.
5  */
6 #ifndef __XFS_DIR2_H__
7 #define __XFS_DIR2_H__
8 
9 #include "xfs_da_format.h"
10 #include "xfs_da_btree.h"
11 
12 struct xfs_da_args;
13 struct xfs_inode;
14 struct xfs_mount;
15 struct xfs_trans;
16 struct xfs_dir2_sf_hdr;
17 struct xfs_dir2_sf_entry;
18 struct xfs_dir2_data_hdr;
19 struct xfs_dir2_data_entry;
20 struct xfs_dir2_data_unused;
21 
22 extern struct xfs_name	xfs_name_dotdot;
23 
24 /*
25  * Convert inode mode to directory entry filetype
26  */
27 extern unsigned char xfs_mode_to_ftype(int mode);
28 
29 /*
30  * directory operations vector for encode/decode routines
31  */
32 struct xfs_dir_ops {
33 	int	(*sf_entsize)(struct xfs_dir2_sf_hdr *hdr, int len);
34 	struct xfs_dir2_sf_entry *
35 		(*sf_nextentry)(struct xfs_dir2_sf_hdr *hdr,
36 				struct xfs_dir2_sf_entry *sfep);
37 	uint8_t (*sf_get_ftype)(struct xfs_dir2_sf_entry *sfep);
38 	void	(*sf_put_ftype)(struct xfs_dir2_sf_entry *sfep,
39 				uint8_t ftype);
40 	xfs_ino_t (*sf_get_ino)(struct xfs_dir2_sf_hdr *hdr,
41 				struct xfs_dir2_sf_entry *sfep);
42 	void	(*sf_put_ino)(struct xfs_dir2_sf_hdr *hdr,
43 			      struct xfs_dir2_sf_entry *sfep,
44 			      xfs_ino_t ino);
45 	xfs_ino_t (*sf_get_parent_ino)(struct xfs_dir2_sf_hdr *hdr);
46 	void	(*sf_put_parent_ino)(struct xfs_dir2_sf_hdr *hdr,
47 				     xfs_ino_t ino);
48 
49 	int	(*data_entsize)(int len);
50 	uint8_t (*data_get_ftype)(struct xfs_dir2_data_entry *dep);
51 	void	(*data_put_ftype)(struct xfs_dir2_data_entry *dep,
52 				uint8_t ftype);
53 	__be16 * (*data_entry_tag_p)(struct xfs_dir2_data_entry *dep);
54 	struct xfs_dir2_data_free *
55 		(*data_bestfree_p)(struct xfs_dir2_data_hdr *hdr);
56 
57 	xfs_dir2_data_aoff_t data_dot_offset;
58 	xfs_dir2_data_aoff_t data_dotdot_offset;
59 	xfs_dir2_data_aoff_t data_first_offset;
60 	size_t	data_entry_offset;
61 
62 	struct xfs_dir2_data_entry *
63 		(*data_dot_entry_p)(struct xfs_dir2_data_hdr *hdr);
64 	struct xfs_dir2_data_entry *
65 		(*data_dotdot_entry_p)(struct xfs_dir2_data_hdr *hdr);
66 	struct xfs_dir2_data_entry *
67 		(*data_first_entry_p)(struct xfs_dir2_data_hdr *hdr);
68 	struct xfs_dir2_data_entry *
69 		(*data_entry_p)(struct xfs_dir2_data_hdr *hdr);
70 	struct xfs_dir2_data_unused *
71 		(*data_unused_p)(struct xfs_dir2_data_hdr *hdr);
72 
73 	int	leaf_hdr_size;
74 	void	(*leaf_hdr_to_disk)(struct xfs_dir2_leaf *to,
75 				    struct xfs_dir3_icleaf_hdr *from);
76 	void	(*leaf_hdr_from_disk)(struct xfs_dir3_icleaf_hdr *to,
77 				      struct xfs_dir2_leaf *from);
78 	int	(*leaf_max_ents)(struct xfs_da_geometry *geo);
79 	struct xfs_dir2_leaf_entry *
80 		(*leaf_ents_p)(struct xfs_dir2_leaf *lp);
81 
82 	int	node_hdr_size;
83 	void	(*node_hdr_to_disk)(struct xfs_da_intnode *to,
84 				    struct xfs_da3_icnode_hdr *from);
85 	void	(*node_hdr_from_disk)(struct xfs_da3_icnode_hdr *to,
86 				      struct xfs_da_intnode *from);
87 	struct xfs_da_node_entry *
88 		(*node_tree_p)(struct xfs_da_intnode *dap);
89 
90 	int	free_hdr_size;
91 	void	(*free_hdr_to_disk)(struct xfs_dir2_free *to,
92 				    struct xfs_dir3_icfree_hdr *from);
93 	void	(*free_hdr_from_disk)(struct xfs_dir3_icfree_hdr *to,
94 				      struct xfs_dir2_free *from);
95 	int	(*free_max_bests)(struct xfs_da_geometry *geo);
96 	__be16 * (*free_bests_p)(struct xfs_dir2_free *free);
97 	xfs_dir2_db_t (*db_to_fdb)(struct xfs_da_geometry *geo,
98 				   xfs_dir2_db_t db);
99 	int	(*db_to_fdindex)(struct xfs_da_geometry *geo,
100 				 xfs_dir2_db_t db);
101 };
102 
103 extern const struct xfs_dir_ops *
104 	xfs_dir_get_ops(struct xfs_mount *mp, struct xfs_inode *dp);
105 extern const struct xfs_dir_ops *
106 	xfs_nondir_get_ops(struct xfs_mount *mp, struct xfs_inode *dp);
107 
108 /*
109  * Generic directory interface routines
110  */
111 extern void xfs_dir_startup(void);
112 extern int xfs_da_mount(struct xfs_mount *mp);
113 extern void xfs_da_unmount(struct xfs_mount *mp);
114 
115 extern int xfs_dir_isempty(struct xfs_inode *dp);
116 extern int xfs_dir_init(struct xfs_trans *tp, struct xfs_inode *dp,
117 				struct xfs_inode *pdp);
118 extern int xfs_dir_createname(struct xfs_trans *tp, struct xfs_inode *dp,
119 				struct xfs_name *name, xfs_ino_t inum,
120 				xfs_extlen_t tot);
121 extern int xfs_dir_lookup(struct xfs_trans *tp, struct xfs_inode *dp,
122 				struct xfs_name *name, xfs_ino_t *inum,
123 				struct xfs_name *ci_name);
124 extern int xfs_dir_removename(struct xfs_trans *tp, struct xfs_inode *dp,
125 				struct xfs_name *name, xfs_ino_t ino,
126 				xfs_extlen_t tot);
127 extern int xfs_dir_replace(struct xfs_trans *tp, struct xfs_inode *dp,
128 				struct xfs_name *name, xfs_ino_t inum,
129 				xfs_extlen_t tot);
130 extern int xfs_dir_canenter(struct xfs_trans *tp, struct xfs_inode *dp,
131 				struct xfs_name *name);
132 
133 /*
134  * Direct call from the bmap code, bypassing the generic directory layer.
135  */
136 extern int xfs_dir2_sf_to_block(struct xfs_da_args *args);
137 
138 /*
139  * Interface routines used by userspace utilities
140  */
141 extern int xfs_dir2_isblock(struct xfs_da_args *args, int *r);
142 extern int xfs_dir2_isleaf(struct xfs_da_args *args, int *r);
143 extern int xfs_dir2_shrink_inode(struct xfs_da_args *args, xfs_dir2_db_t db,
144 				struct xfs_buf *bp);
145 
146 extern void xfs_dir2_data_freescan_int(struct xfs_da_geometry *geo,
147 		const struct xfs_dir_ops *ops,
148 		struct xfs_dir2_data_hdr *hdr, int *loghead);
149 extern void xfs_dir2_data_freescan(struct xfs_inode *dp,
150 		struct xfs_dir2_data_hdr *hdr, int *loghead);
151 extern void xfs_dir2_data_log_entry(struct xfs_da_args *args,
152 		struct xfs_buf *bp, struct xfs_dir2_data_entry *dep);
153 extern void xfs_dir2_data_log_header(struct xfs_da_args *args,
154 		struct xfs_buf *bp);
155 extern void xfs_dir2_data_log_unused(struct xfs_da_args *args,
156 		struct xfs_buf *bp, struct xfs_dir2_data_unused *dup);
157 extern void xfs_dir2_data_make_free(struct xfs_da_args *args,
158 		struct xfs_buf *bp, xfs_dir2_data_aoff_t offset,
159 		xfs_dir2_data_aoff_t len, int *needlogp, int *needscanp);
160 extern int xfs_dir2_data_use_free(struct xfs_da_args *args,
161 		struct xfs_buf *bp, struct xfs_dir2_data_unused *dup,
162 		xfs_dir2_data_aoff_t offset, xfs_dir2_data_aoff_t len,
163 		int *needlogp, int *needscanp);
164 
165 extern struct xfs_dir2_data_free *xfs_dir2_data_freefind(
166 		struct xfs_dir2_data_hdr *hdr, struct xfs_dir2_data_free *bf,
167 		struct xfs_dir2_data_unused *dup);
168 
169 extern int xfs_dir_ino_validate(struct xfs_mount *mp, xfs_ino_t ino);
170 
171 extern const struct xfs_buf_ops xfs_dir3_block_buf_ops;
172 extern const struct xfs_buf_ops xfs_dir3_leafn_buf_ops;
173 extern const struct xfs_buf_ops xfs_dir3_leaf1_buf_ops;
174 extern const struct xfs_buf_ops xfs_dir3_free_buf_ops;
175 extern const struct xfs_buf_ops xfs_dir3_data_buf_ops;
176 
177 /*
178  * Directory offset/block conversion functions.
179  *
180  * DB blocks here are logical directory block numbers, not filesystem blocks.
181  */
182 
183 /*
184  * Convert dataptr to byte in file space
185  */
186 static inline xfs_dir2_off_t
187 xfs_dir2_dataptr_to_byte(xfs_dir2_dataptr_t dp)
188 {
189 	return (xfs_dir2_off_t)dp << XFS_DIR2_DATA_ALIGN_LOG;
190 }
191 
192 /*
193  * Convert byte in file space to dataptr.  It had better be aligned.
194  */
195 static inline xfs_dir2_dataptr_t
196 xfs_dir2_byte_to_dataptr(xfs_dir2_off_t by)
197 {
198 	return (xfs_dir2_dataptr_t)(by >> XFS_DIR2_DATA_ALIGN_LOG);
199 }
200 
201 /*
202  * Convert byte in space to (DB) block
203  */
204 static inline xfs_dir2_db_t
205 xfs_dir2_byte_to_db(struct xfs_da_geometry *geo, xfs_dir2_off_t by)
206 {
207 	return (xfs_dir2_db_t)(by >> geo->blklog);
208 }
209 
210 /*
211  * Convert dataptr to a block number
212  */
213 static inline xfs_dir2_db_t
214 xfs_dir2_dataptr_to_db(struct xfs_da_geometry *geo, xfs_dir2_dataptr_t dp)
215 {
216 	return xfs_dir2_byte_to_db(geo, xfs_dir2_dataptr_to_byte(dp));
217 }
218 
219 /*
220  * Convert byte in space to offset in a block
221  */
222 static inline xfs_dir2_data_aoff_t
223 xfs_dir2_byte_to_off(struct xfs_da_geometry *geo, xfs_dir2_off_t by)
224 {
225 	return (xfs_dir2_data_aoff_t)(by & (geo->blksize - 1));
226 }
227 
228 /*
229  * Convert dataptr to a byte offset in a block
230  */
231 static inline xfs_dir2_data_aoff_t
232 xfs_dir2_dataptr_to_off(struct xfs_da_geometry *geo, xfs_dir2_dataptr_t dp)
233 {
234 	return xfs_dir2_byte_to_off(geo, xfs_dir2_dataptr_to_byte(dp));
235 }
236 
237 /*
238  * Convert block and offset to byte in space
239  */
240 static inline xfs_dir2_off_t
241 xfs_dir2_db_off_to_byte(struct xfs_da_geometry *geo, xfs_dir2_db_t db,
242 			xfs_dir2_data_aoff_t o)
243 {
244 	return ((xfs_dir2_off_t)db << geo->blklog) + o;
245 }
246 
247 /*
248  * Convert block (DB) to block (dablk)
249  */
250 static inline xfs_dablk_t
251 xfs_dir2_db_to_da(struct xfs_da_geometry *geo, xfs_dir2_db_t db)
252 {
253 	return (xfs_dablk_t)(db << (geo->blklog - geo->fsblog));
254 }
255 
256 /*
257  * Convert byte in space to (DA) block
258  */
259 static inline xfs_dablk_t
260 xfs_dir2_byte_to_da(struct xfs_da_geometry *geo, xfs_dir2_off_t by)
261 {
262 	return xfs_dir2_db_to_da(geo, xfs_dir2_byte_to_db(geo, by));
263 }
264 
265 /*
266  * Convert block and offset to dataptr
267  */
268 static inline xfs_dir2_dataptr_t
269 xfs_dir2_db_off_to_dataptr(struct xfs_da_geometry *geo, xfs_dir2_db_t db,
270 			   xfs_dir2_data_aoff_t o)
271 {
272 	return xfs_dir2_byte_to_dataptr(xfs_dir2_db_off_to_byte(geo, db, o));
273 }
274 
275 /*
276  * Convert block (dablk) to block (DB)
277  */
278 static inline xfs_dir2_db_t
279 xfs_dir2_da_to_db(struct xfs_da_geometry *geo, xfs_dablk_t da)
280 {
281 	return (xfs_dir2_db_t)(da >> (geo->blklog - geo->fsblog));
282 }
283 
284 /*
285  * Convert block (dablk) to byte offset in space
286  */
287 static inline xfs_dir2_off_t
288 xfs_dir2_da_to_byte(struct xfs_da_geometry *geo, xfs_dablk_t da)
289 {
290 	return xfs_dir2_db_off_to_byte(geo, xfs_dir2_da_to_db(geo, da), 0);
291 }
292 
293 /*
294  * Directory tail pointer accessor functions. Based on block geometry.
295  */
296 static inline struct xfs_dir2_block_tail *
297 xfs_dir2_block_tail_p(struct xfs_da_geometry *geo, struct xfs_dir2_data_hdr *hdr)
298 {
299 	return ((struct xfs_dir2_block_tail *)
300 		((char *)hdr + geo->blksize)) - 1;
301 }
302 
303 static inline struct xfs_dir2_leaf_tail *
304 xfs_dir2_leaf_tail_p(struct xfs_da_geometry *geo, struct xfs_dir2_leaf *lp)
305 {
306 	return (struct xfs_dir2_leaf_tail *)
307 		((char *)lp + geo->blksize -
308 		  sizeof(struct xfs_dir2_leaf_tail));
309 }
310 
311 /*
312  * The Linux API doesn't pass down the total size of the buffer
313  * we read into down to the filesystem.  With the filldir concept
314  * it's not needed for correct information, but the XFS dir2 leaf
315  * code wants an estimate of the buffer size to calculate it's
316  * readahead window and size the buffers used for mapping to
317  * physical blocks.
318  *
319  * Try to give it an estimate that's good enough, maybe at some
320  * point we can change the ->readdir prototype to include the
321  * buffer size.  For now we use the current glibc buffer size.
322  * musl libc hardcodes 2k and dietlibc uses PAGE_SIZE.
323  */
324 #define XFS_READDIR_BUFSIZE	(32768)
325 
326 unsigned char xfs_dir3_get_dtype(struct xfs_mount *mp, uint8_t filetype);
327 void *xfs_dir3_data_endp(struct xfs_da_geometry *geo,
328 		struct xfs_dir2_data_hdr *hdr);
329 bool xfs_dir2_namecheck(const void *name, size_t length);
330 
331 #endif	/* __XFS_DIR2_H__ */
332