xref: /linux/fs/xfs/libxfs/xfs_dir2.h (revision 787b0893ad1e315ea014dc3f0e01a5bc9236c623)
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 struct xfs_dir3_icfree_hdr;
22 struct xfs_dir3_icleaf_hdr;
23 
24 extern struct xfs_name	xfs_name_dotdot;
25 
26 /*
27  * Convert inode mode to directory entry filetype
28  */
29 extern unsigned char xfs_mode_to_ftype(int mode);
30 
31 /*
32  * directory operations vector for encode/decode routines
33  */
34 struct xfs_dir_ops {
35 	int	(*sf_entsize)(struct xfs_dir2_sf_hdr *hdr, int len);
36 	struct xfs_dir2_sf_entry *
37 		(*sf_nextentry)(struct xfs_dir2_sf_hdr *hdr,
38 				struct xfs_dir2_sf_entry *sfep);
39 	uint8_t (*sf_get_ftype)(struct xfs_dir2_sf_entry *sfep);
40 	void	(*sf_put_ftype)(struct xfs_dir2_sf_entry *sfep,
41 				uint8_t ftype);
42 	xfs_ino_t (*sf_get_ino)(struct xfs_dir2_sf_hdr *hdr,
43 				struct xfs_dir2_sf_entry *sfep);
44 	void	(*sf_put_ino)(struct xfs_dir2_sf_hdr *hdr,
45 			      struct xfs_dir2_sf_entry *sfep,
46 			      xfs_ino_t ino);
47 	xfs_ino_t (*sf_get_parent_ino)(struct xfs_dir2_sf_hdr *hdr);
48 	void	(*sf_put_parent_ino)(struct xfs_dir2_sf_hdr *hdr,
49 				     xfs_ino_t ino);
50 
51 	int	(*data_entsize)(int len);
52 	uint8_t (*data_get_ftype)(struct xfs_dir2_data_entry *dep);
53 	void	(*data_put_ftype)(struct xfs_dir2_data_entry *dep,
54 				uint8_t ftype);
55 	__be16 * (*data_entry_tag_p)(struct xfs_dir2_data_entry *dep);
56 	struct xfs_dir2_data_free *
57 		(*data_bestfree_p)(struct xfs_dir2_data_hdr *hdr);
58 
59 	xfs_dir2_data_aoff_t data_dot_offset;
60 	xfs_dir2_data_aoff_t data_dotdot_offset;
61 	xfs_dir2_data_aoff_t data_first_offset;
62 	size_t	data_entry_offset;
63 
64 	struct xfs_dir2_data_entry *
65 		(*data_dot_entry_p)(struct xfs_dir2_data_hdr *hdr);
66 	struct xfs_dir2_data_entry *
67 		(*data_dotdot_entry_p)(struct xfs_dir2_data_hdr *hdr);
68 	struct xfs_dir2_data_entry *
69 		(*data_first_entry_p)(struct xfs_dir2_data_hdr *hdr);
70 	struct xfs_dir2_data_entry *
71 		(*data_entry_p)(struct xfs_dir2_data_hdr *hdr);
72 	struct xfs_dir2_data_unused *
73 		(*data_unused_p)(struct xfs_dir2_data_hdr *hdr);
74 
75 	int	leaf_hdr_size;
76 	int	(*leaf_max_ents)(struct xfs_da_geometry *geo);
77 
78 	int	free_hdr_size;
79 	void	(*free_hdr_to_disk)(struct xfs_dir2_free *to,
80 				    struct xfs_dir3_icfree_hdr *from);
81 	void	(*free_hdr_from_disk)(struct xfs_dir3_icfree_hdr *to,
82 				      struct xfs_dir2_free *from);
83 	int	(*free_max_bests)(struct xfs_da_geometry *geo);
84 	__be16 * (*free_bests_p)(struct xfs_dir2_free *free);
85 	xfs_dir2_db_t (*db_to_fdb)(struct xfs_da_geometry *geo,
86 				   xfs_dir2_db_t db);
87 	int	(*db_to_fdindex)(struct xfs_da_geometry *geo,
88 				 xfs_dir2_db_t db);
89 };
90 
91 extern const struct xfs_dir_ops *
92 	xfs_dir_get_ops(struct xfs_mount *mp, struct xfs_inode *dp);
93 
94 /*
95  * Generic directory interface routines
96  */
97 extern void xfs_dir_startup(void);
98 extern int xfs_da_mount(struct xfs_mount *mp);
99 extern void xfs_da_unmount(struct xfs_mount *mp);
100 
101 extern int xfs_dir_isempty(struct xfs_inode *dp);
102 extern int xfs_dir_init(struct xfs_trans *tp, struct xfs_inode *dp,
103 				struct xfs_inode *pdp);
104 extern int xfs_dir_createname(struct xfs_trans *tp, struct xfs_inode *dp,
105 				struct xfs_name *name, xfs_ino_t inum,
106 				xfs_extlen_t tot);
107 extern int xfs_dir_lookup(struct xfs_trans *tp, struct xfs_inode *dp,
108 				struct xfs_name *name, xfs_ino_t *inum,
109 				struct xfs_name *ci_name);
110 extern int xfs_dir_removename(struct xfs_trans *tp, struct xfs_inode *dp,
111 				struct xfs_name *name, xfs_ino_t ino,
112 				xfs_extlen_t tot);
113 extern int xfs_dir_replace(struct xfs_trans *tp, struct xfs_inode *dp,
114 				struct xfs_name *name, xfs_ino_t inum,
115 				xfs_extlen_t tot);
116 extern int xfs_dir_canenter(struct xfs_trans *tp, struct xfs_inode *dp,
117 				struct xfs_name *name);
118 
119 /*
120  * Direct call from the bmap code, bypassing the generic directory layer.
121  */
122 extern int xfs_dir2_sf_to_block(struct xfs_da_args *args);
123 
124 /*
125  * Interface routines used by userspace utilities
126  */
127 extern int xfs_dir2_isblock(struct xfs_da_args *args, int *r);
128 extern int xfs_dir2_isleaf(struct xfs_da_args *args, int *r);
129 extern int xfs_dir2_shrink_inode(struct xfs_da_args *args, xfs_dir2_db_t db,
130 				struct xfs_buf *bp);
131 
132 extern void xfs_dir2_data_freescan_int(struct xfs_da_geometry *geo,
133 		const struct xfs_dir_ops *ops,
134 		struct xfs_dir2_data_hdr *hdr, int *loghead);
135 extern void xfs_dir2_data_freescan(struct xfs_inode *dp,
136 		struct xfs_dir2_data_hdr *hdr, int *loghead);
137 extern void xfs_dir2_data_log_entry(struct xfs_da_args *args,
138 		struct xfs_buf *bp, struct xfs_dir2_data_entry *dep);
139 extern void xfs_dir2_data_log_header(struct xfs_da_args *args,
140 		struct xfs_buf *bp);
141 extern void xfs_dir2_data_log_unused(struct xfs_da_args *args,
142 		struct xfs_buf *bp, struct xfs_dir2_data_unused *dup);
143 extern void xfs_dir2_data_make_free(struct xfs_da_args *args,
144 		struct xfs_buf *bp, xfs_dir2_data_aoff_t offset,
145 		xfs_dir2_data_aoff_t len, int *needlogp, int *needscanp);
146 extern int xfs_dir2_data_use_free(struct xfs_da_args *args,
147 		struct xfs_buf *bp, struct xfs_dir2_data_unused *dup,
148 		xfs_dir2_data_aoff_t offset, xfs_dir2_data_aoff_t len,
149 		int *needlogp, int *needscanp);
150 
151 extern struct xfs_dir2_data_free *xfs_dir2_data_freefind(
152 		struct xfs_dir2_data_hdr *hdr, struct xfs_dir2_data_free *bf,
153 		struct xfs_dir2_data_unused *dup);
154 
155 extern int xfs_dir_ino_validate(struct xfs_mount *mp, xfs_ino_t ino);
156 
157 extern const struct xfs_buf_ops xfs_dir3_block_buf_ops;
158 extern const struct xfs_buf_ops xfs_dir3_leafn_buf_ops;
159 extern const struct xfs_buf_ops xfs_dir3_leaf1_buf_ops;
160 extern const struct xfs_buf_ops xfs_dir3_free_buf_ops;
161 extern const struct xfs_buf_ops xfs_dir3_data_buf_ops;
162 
163 /*
164  * Directory offset/block conversion functions.
165  *
166  * DB blocks here are logical directory block numbers, not filesystem blocks.
167  */
168 
169 /*
170  * Convert dataptr to byte in file space
171  */
172 static inline xfs_dir2_off_t
173 xfs_dir2_dataptr_to_byte(xfs_dir2_dataptr_t dp)
174 {
175 	return (xfs_dir2_off_t)dp << XFS_DIR2_DATA_ALIGN_LOG;
176 }
177 
178 /*
179  * Convert byte in file space to dataptr.  It had better be aligned.
180  */
181 static inline xfs_dir2_dataptr_t
182 xfs_dir2_byte_to_dataptr(xfs_dir2_off_t by)
183 {
184 	return (xfs_dir2_dataptr_t)(by >> XFS_DIR2_DATA_ALIGN_LOG);
185 }
186 
187 /*
188  * Convert byte in space to (DB) block
189  */
190 static inline xfs_dir2_db_t
191 xfs_dir2_byte_to_db(struct xfs_da_geometry *geo, xfs_dir2_off_t by)
192 {
193 	return (xfs_dir2_db_t)(by >> geo->blklog);
194 }
195 
196 /*
197  * Convert dataptr to a block number
198  */
199 static inline xfs_dir2_db_t
200 xfs_dir2_dataptr_to_db(struct xfs_da_geometry *geo, xfs_dir2_dataptr_t dp)
201 {
202 	return xfs_dir2_byte_to_db(geo, xfs_dir2_dataptr_to_byte(dp));
203 }
204 
205 /*
206  * Convert byte in space to offset in a block
207  */
208 static inline xfs_dir2_data_aoff_t
209 xfs_dir2_byte_to_off(struct xfs_da_geometry *geo, xfs_dir2_off_t by)
210 {
211 	return (xfs_dir2_data_aoff_t)(by & (geo->blksize - 1));
212 }
213 
214 /*
215  * Convert dataptr to a byte offset in a block
216  */
217 static inline xfs_dir2_data_aoff_t
218 xfs_dir2_dataptr_to_off(struct xfs_da_geometry *geo, xfs_dir2_dataptr_t dp)
219 {
220 	return xfs_dir2_byte_to_off(geo, xfs_dir2_dataptr_to_byte(dp));
221 }
222 
223 /*
224  * Convert block and offset to byte in space
225  */
226 static inline xfs_dir2_off_t
227 xfs_dir2_db_off_to_byte(struct xfs_da_geometry *geo, xfs_dir2_db_t db,
228 			xfs_dir2_data_aoff_t o)
229 {
230 	return ((xfs_dir2_off_t)db << geo->blklog) + o;
231 }
232 
233 /*
234  * Convert block (DB) to block (dablk)
235  */
236 static inline xfs_dablk_t
237 xfs_dir2_db_to_da(struct xfs_da_geometry *geo, xfs_dir2_db_t db)
238 {
239 	return (xfs_dablk_t)(db << (geo->blklog - geo->fsblog));
240 }
241 
242 /*
243  * Convert byte in space to (DA) block
244  */
245 static inline xfs_dablk_t
246 xfs_dir2_byte_to_da(struct xfs_da_geometry *geo, xfs_dir2_off_t by)
247 {
248 	return xfs_dir2_db_to_da(geo, xfs_dir2_byte_to_db(geo, by));
249 }
250 
251 /*
252  * Convert block and offset to dataptr
253  */
254 static inline xfs_dir2_dataptr_t
255 xfs_dir2_db_off_to_dataptr(struct xfs_da_geometry *geo, xfs_dir2_db_t db,
256 			   xfs_dir2_data_aoff_t o)
257 {
258 	return xfs_dir2_byte_to_dataptr(xfs_dir2_db_off_to_byte(geo, db, o));
259 }
260 
261 /*
262  * Convert block (dablk) to block (DB)
263  */
264 static inline xfs_dir2_db_t
265 xfs_dir2_da_to_db(struct xfs_da_geometry *geo, xfs_dablk_t da)
266 {
267 	return (xfs_dir2_db_t)(da >> (geo->blklog - geo->fsblog));
268 }
269 
270 /*
271  * Convert block (dablk) to byte offset in space
272  */
273 static inline xfs_dir2_off_t
274 xfs_dir2_da_to_byte(struct xfs_da_geometry *geo, xfs_dablk_t da)
275 {
276 	return xfs_dir2_db_off_to_byte(geo, xfs_dir2_da_to_db(geo, da), 0);
277 }
278 
279 /*
280  * Directory tail pointer accessor functions. Based on block geometry.
281  */
282 static inline struct xfs_dir2_block_tail *
283 xfs_dir2_block_tail_p(struct xfs_da_geometry *geo, struct xfs_dir2_data_hdr *hdr)
284 {
285 	return ((struct xfs_dir2_block_tail *)
286 		((char *)hdr + geo->blksize)) - 1;
287 }
288 
289 static inline struct xfs_dir2_leaf_tail *
290 xfs_dir2_leaf_tail_p(struct xfs_da_geometry *geo, struct xfs_dir2_leaf *lp)
291 {
292 	return (struct xfs_dir2_leaf_tail *)
293 		((char *)lp + geo->blksize -
294 		  sizeof(struct xfs_dir2_leaf_tail));
295 }
296 
297 /*
298  * The Linux API doesn't pass down the total size of the buffer
299  * we read into down to the filesystem.  With the filldir concept
300  * it's not needed for correct information, but the XFS dir2 leaf
301  * code wants an estimate of the buffer size to calculate it's
302  * readahead window and size the buffers used for mapping to
303  * physical blocks.
304  *
305  * Try to give it an estimate that's good enough, maybe at some
306  * point we can change the ->readdir prototype to include the
307  * buffer size.  For now we use the current glibc buffer size.
308  * musl libc hardcodes 2k and dietlibc uses PAGE_SIZE.
309  */
310 #define XFS_READDIR_BUFSIZE	(32768)
311 
312 unsigned char xfs_dir3_get_dtype(struct xfs_mount *mp, uint8_t filetype);
313 void *xfs_dir3_data_endp(struct xfs_da_geometry *geo,
314 		struct xfs_dir2_data_hdr *hdr);
315 bool xfs_dir2_namecheck(const void *name, size_t length);
316 
317 #endif	/* __XFS_DIR2_H__ */
318