xref: /linux/fs/xfs/libxfs/xfs_dir2.h (revision 545910bcc875377160b7b669e790865602a006f3)
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_max_ents)(struct xfs_da_geometry *geo);
76 
77 	int	free_hdr_size;
78 	void	(*free_hdr_to_disk)(struct xfs_dir2_free *to,
79 				    struct xfs_dir3_icfree_hdr *from);
80 	void	(*free_hdr_from_disk)(struct xfs_dir3_icfree_hdr *to,
81 				      struct xfs_dir2_free *from);
82 	int	(*free_max_bests)(struct xfs_da_geometry *geo);
83 	__be16 * (*free_bests_p)(struct xfs_dir2_free *free);
84 	xfs_dir2_db_t (*db_to_fdb)(struct xfs_da_geometry *geo,
85 				   xfs_dir2_db_t db);
86 	int	(*db_to_fdindex)(struct xfs_da_geometry *geo,
87 				 xfs_dir2_db_t db);
88 };
89 
90 extern const struct xfs_dir_ops *
91 	xfs_dir_get_ops(struct xfs_mount *mp, struct xfs_inode *dp);
92 
93 /*
94  * Generic directory interface routines
95  */
96 extern void xfs_dir_startup(void);
97 extern int xfs_da_mount(struct xfs_mount *mp);
98 extern void xfs_da_unmount(struct xfs_mount *mp);
99 
100 extern int xfs_dir_isempty(struct xfs_inode *dp);
101 extern int xfs_dir_init(struct xfs_trans *tp, struct xfs_inode *dp,
102 				struct xfs_inode *pdp);
103 extern int xfs_dir_createname(struct xfs_trans *tp, struct xfs_inode *dp,
104 				struct xfs_name *name, xfs_ino_t inum,
105 				xfs_extlen_t tot);
106 extern int xfs_dir_lookup(struct xfs_trans *tp, struct xfs_inode *dp,
107 				struct xfs_name *name, xfs_ino_t *inum,
108 				struct xfs_name *ci_name);
109 extern int xfs_dir_removename(struct xfs_trans *tp, struct xfs_inode *dp,
110 				struct xfs_name *name, xfs_ino_t ino,
111 				xfs_extlen_t tot);
112 extern int xfs_dir_replace(struct xfs_trans *tp, struct xfs_inode *dp,
113 				struct xfs_name *name, xfs_ino_t inum,
114 				xfs_extlen_t tot);
115 extern int xfs_dir_canenter(struct xfs_trans *tp, struct xfs_inode *dp,
116 				struct xfs_name *name);
117 
118 /*
119  * Direct call from the bmap code, bypassing the generic directory layer.
120  */
121 extern int xfs_dir2_sf_to_block(struct xfs_da_args *args);
122 
123 /*
124  * Interface routines used by userspace utilities
125  */
126 extern int xfs_dir2_isblock(struct xfs_da_args *args, int *r);
127 extern int xfs_dir2_isleaf(struct xfs_da_args *args, int *r);
128 extern int xfs_dir2_shrink_inode(struct xfs_da_args *args, xfs_dir2_db_t db,
129 				struct xfs_buf *bp);
130 
131 extern void xfs_dir2_data_freescan_int(struct xfs_da_geometry *geo,
132 		const struct xfs_dir_ops *ops,
133 		struct xfs_dir2_data_hdr *hdr, int *loghead);
134 extern void xfs_dir2_data_freescan(struct xfs_inode *dp,
135 		struct xfs_dir2_data_hdr *hdr, int *loghead);
136 extern void xfs_dir2_data_log_entry(struct xfs_da_args *args,
137 		struct xfs_buf *bp, struct xfs_dir2_data_entry *dep);
138 extern void xfs_dir2_data_log_header(struct xfs_da_args *args,
139 		struct xfs_buf *bp);
140 extern void xfs_dir2_data_log_unused(struct xfs_da_args *args,
141 		struct xfs_buf *bp, struct xfs_dir2_data_unused *dup);
142 extern void xfs_dir2_data_make_free(struct xfs_da_args *args,
143 		struct xfs_buf *bp, xfs_dir2_data_aoff_t offset,
144 		xfs_dir2_data_aoff_t len, int *needlogp, int *needscanp);
145 extern int xfs_dir2_data_use_free(struct xfs_da_args *args,
146 		struct xfs_buf *bp, struct xfs_dir2_data_unused *dup,
147 		xfs_dir2_data_aoff_t offset, xfs_dir2_data_aoff_t len,
148 		int *needlogp, int *needscanp);
149 
150 extern struct xfs_dir2_data_free *xfs_dir2_data_freefind(
151 		struct xfs_dir2_data_hdr *hdr, struct xfs_dir2_data_free *bf,
152 		struct xfs_dir2_data_unused *dup);
153 
154 extern int xfs_dir_ino_validate(struct xfs_mount *mp, xfs_ino_t ino);
155 
156 extern const struct xfs_buf_ops xfs_dir3_block_buf_ops;
157 extern const struct xfs_buf_ops xfs_dir3_leafn_buf_ops;
158 extern const struct xfs_buf_ops xfs_dir3_leaf1_buf_ops;
159 extern const struct xfs_buf_ops xfs_dir3_free_buf_ops;
160 extern const struct xfs_buf_ops xfs_dir3_data_buf_ops;
161 
162 /*
163  * Directory offset/block conversion functions.
164  *
165  * DB blocks here are logical directory block numbers, not filesystem blocks.
166  */
167 
168 /*
169  * Convert dataptr to byte in file space
170  */
171 static inline xfs_dir2_off_t
172 xfs_dir2_dataptr_to_byte(xfs_dir2_dataptr_t dp)
173 {
174 	return (xfs_dir2_off_t)dp << XFS_DIR2_DATA_ALIGN_LOG;
175 }
176 
177 /*
178  * Convert byte in file space to dataptr.  It had better be aligned.
179  */
180 static inline xfs_dir2_dataptr_t
181 xfs_dir2_byte_to_dataptr(xfs_dir2_off_t by)
182 {
183 	return (xfs_dir2_dataptr_t)(by >> XFS_DIR2_DATA_ALIGN_LOG);
184 }
185 
186 /*
187  * Convert byte in space to (DB) block
188  */
189 static inline xfs_dir2_db_t
190 xfs_dir2_byte_to_db(struct xfs_da_geometry *geo, xfs_dir2_off_t by)
191 {
192 	return (xfs_dir2_db_t)(by >> geo->blklog);
193 }
194 
195 /*
196  * Convert dataptr to a block number
197  */
198 static inline xfs_dir2_db_t
199 xfs_dir2_dataptr_to_db(struct xfs_da_geometry *geo, xfs_dir2_dataptr_t dp)
200 {
201 	return xfs_dir2_byte_to_db(geo, xfs_dir2_dataptr_to_byte(dp));
202 }
203 
204 /*
205  * Convert byte in space to offset in a block
206  */
207 static inline xfs_dir2_data_aoff_t
208 xfs_dir2_byte_to_off(struct xfs_da_geometry *geo, xfs_dir2_off_t by)
209 {
210 	return (xfs_dir2_data_aoff_t)(by & (geo->blksize - 1));
211 }
212 
213 /*
214  * Convert dataptr to a byte offset in a block
215  */
216 static inline xfs_dir2_data_aoff_t
217 xfs_dir2_dataptr_to_off(struct xfs_da_geometry *geo, xfs_dir2_dataptr_t dp)
218 {
219 	return xfs_dir2_byte_to_off(geo, xfs_dir2_dataptr_to_byte(dp));
220 }
221 
222 /*
223  * Convert block and offset to byte in space
224  */
225 static inline xfs_dir2_off_t
226 xfs_dir2_db_off_to_byte(struct xfs_da_geometry *geo, xfs_dir2_db_t db,
227 			xfs_dir2_data_aoff_t o)
228 {
229 	return ((xfs_dir2_off_t)db << geo->blklog) + o;
230 }
231 
232 /*
233  * Convert block (DB) to block (dablk)
234  */
235 static inline xfs_dablk_t
236 xfs_dir2_db_to_da(struct xfs_da_geometry *geo, xfs_dir2_db_t db)
237 {
238 	return (xfs_dablk_t)(db << (geo->blklog - geo->fsblog));
239 }
240 
241 /*
242  * Convert byte in space to (DA) block
243  */
244 static inline xfs_dablk_t
245 xfs_dir2_byte_to_da(struct xfs_da_geometry *geo, xfs_dir2_off_t by)
246 {
247 	return xfs_dir2_db_to_da(geo, xfs_dir2_byte_to_db(geo, by));
248 }
249 
250 /*
251  * Convert block and offset to dataptr
252  */
253 static inline xfs_dir2_dataptr_t
254 xfs_dir2_db_off_to_dataptr(struct xfs_da_geometry *geo, xfs_dir2_db_t db,
255 			   xfs_dir2_data_aoff_t o)
256 {
257 	return xfs_dir2_byte_to_dataptr(xfs_dir2_db_off_to_byte(geo, db, o));
258 }
259 
260 /*
261  * Convert block (dablk) to block (DB)
262  */
263 static inline xfs_dir2_db_t
264 xfs_dir2_da_to_db(struct xfs_da_geometry *geo, xfs_dablk_t da)
265 {
266 	return (xfs_dir2_db_t)(da >> (geo->blklog - geo->fsblog));
267 }
268 
269 /*
270  * Convert block (dablk) to byte offset in space
271  */
272 static inline xfs_dir2_off_t
273 xfs_dir2_da_to_byte(struct xfs_da_geometry *geo, xfs_dablk_t da)
274 {
275 	return xfs_dir2_db_off_to_byte(geo, xfs_dir2_da_to_db(geo, da), 0);
276 }
277 
278 /*
279  * Directory tail pointer accessor functions. Based on block geometry.
280  */
281 static inline struct xfs_dir2_block_tail *
282 xfs_dir2_block_tail_p(struct xfs_da_geometry *geo, struct xfs_dir2_data_hdr *hdr)
283 {
284 	return ((struct xfs_dir2_block_tail *)
285 		((char *)hdr + geo->blksize)) - 1;
286 }
287 
288 static inline struct xfs_dir2_leaf_tail *
289 xfs_dir2_leaf_tail_p(struct xfs_da_geometry *geo, struct xfs_dir2_leaf *lp)
290 {
291 	return (struct xfs_dir2_leaf_tail *)
292 		((char *)lp + geo->blksize -
293 		  sizeof(struct xfs_dir2_leaf_tail));
294 }
295 
296 /*
297  * The Linux API doesn't pass down the total size of the buffer
298  * we read into down to the filesystem.  With the filldir concept
299  * it's not needed for correct information, but the XFS dir2 leaf
300  * code wants an estimate of the buffer size to calculate it's
301  * readahead window and size the buffers used for mapping to
302  * physical blocks.
303  *
304  * Try to give it an estimate that's good enough, maybe at some
305  * point we can change the ->readdir prototype to include the
306  * buffer size.  For now we use the current glibc buffer size.
307  * musl libc hardcodes 2k and dietlibc uses PAGE_SIZE.
308  */
309 #define XFS_READDIR_BUFSIZE	(32768)
310 
311 unsigned char xfs_dir3_get_dtype(struct xfs_mount *mp, uint8_t filetype);
312 void *xfs_dir3_data_endp(struct xfs_da_geometry *geo,
313 		struct xfs_dir2_data_hdr *hdr);
314 bool xfs_dir2_namecheck(const void *name, size_t length);
315 
316 #endif	/* __XFS_DIR2_H__ */
317