xref: /linux/fs/xfs/libxfs/xfs_dir2.h (revision 9a379e77033f02c4a071891afdf0f0a01eff8ccb)
1 /*
2  * Copyright (c) 2000-2001,2005 Silicon Graphics, Inc.
3  * All Rights Reserved.
4  *
5  * This program is free software; you can redistribute it and/or
6  * modify it under the terms of the GNU General Public License as
7  * published by the Free Software Foundation.
8  *
9  * This program is distributed in the hope that it would be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write the Free Software Foundation,
16  * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
17  */
18 #ifndef __XFS_DIR2_H__
19 #define __XFS_DIR2_H__
20 
21 #include "xfs_da_format.h"
22 #include "xfs_da_btree.h"
23 
24 struct xfs_defer_ops;
25 struct xfs_da_args;
26 struct xfs_inode;
27 struct xfs_mount;
28 struct xfs_trans;
29 struct xfs_dir2_sf_hdr;
30 struct xfs_dir2_sf_entry;
31 struct xfs_dir2_data_hdr;
32 struct xfs_dir2_data_entry;
33 struct xfs_dir2_data_unused;
34 
35 extern struct xfs_name	xfs_name_dotdot;
36 
37 /*
38  * Convert inode mode to directory entry filetype
39  */
40 extern unsigned char xfs_mode_to_ftype(int mode);
41 
42 /*
43  * directory operations vector for encode/decode routines
44  */
45 struct xfs_dir_ops {
46 	int	(*sf_entsize)(struct xfs_dir2_sf_hdr *hdr, int len);
47 	struct xfs_dir2_sf_entry *
48 		(*sf_nextentry)(struct xfs_dir2_sf_hdr *hdr,
49 				struct xfs_dir2_sf_entry *sfep);
50 	uint8_t (*sf_get_ftype)(struct xfs_dir2_sf_entry *sfep);
51 	void	(*sf_put_ftype)(struct xfs_dir2_sf_entry *sfep,
52 				uint8_t ftype);
53 	xfs_ino_t (*sf_get_ino)(struct xfs_dir2_sf_hdr *hdr,
54 				struct xfs_dir2_sf_entry *sfep);
55 	void	(*sf_put_ino)(struct xfs_dir2_sf_hdr *hdr,
56 			      struct xfs_dir2_sf_entry *sfep,
57 			      xfs_ino_t ino);
58 	xfs_ino_t (*sf_get_parent_ino)(struct xfs_dir2_sf_hdr *hdr);
59 	void	(*sf_put_parent_ino)(struct xfs_dir2_sf_hdr *hdr,
60 				     xfs_ino_t ino);
61 
62 	int	(*data_entsize)(int len);
63 	uint8_t (*data_get_ftype)(struct xfs_dir2_data_entry *dep);
64 	void	(*data_put_ftype)(struct xfs_dir2_data_entry *dep,
65 				uint8_t ftype);
66 	__be16 * (*data_entry_tag_p)(struct xfs_dir2_data_entry *dep);
67 	struct xfs_dir2_data_free *
68 		(*data_bestfree_p)(struct xfs_dir2_data_hdr *hdr);
69 
70 	xfs_dir2_data_aoff_t data_dot_offset;
71 	xfs_dir2_data_aoff_t data_dotdot_offset;
72 	xfs_dir2_data_aoff_t data_first_offset;
73 	size_t	data_entry_offset;
74 
75 	struct xfs_dir2_data_entry *
76 		(*data_dot_entry_p)(struct xfs_dir2_data_hdr *hdr);
77 	struct xfs_dir2_data_entry *
78 		(*data_dotdot_entry_p)(struct xfs_dir2_data_hdr *hdr);
79 	struct xfs_dir2_data_entry *
80 		(*data_first_entry_p)(struct xfs_dir2_data_hdr *hdr);
81 	struct xfs_dir2_data_entry *
82 		(*data_entry_p)(struct xfs_dir2_data_hdr *hdr);
83 	struct xfs_dir2_data_unused *
84 		(*data_unused_p)(struct xfs_dir2_data_hdr *hdr);
85 
86 	int	leaf_hdr_size;
87 	void	(*leaf_hdr_to_disk)(struct xfs_dir2_leaf *to,
88 				    struct xfs_dir3_icleaf_hdr *from);
89 	void	(*leaf_hdr_from_disk)(struct xfs_dir3_icleaf_hdr *to,
90 				      struct xfs_dir2_leaf *from);
91 	int	(*leaf_max_ents)(struct xfs_da_geometry *geo);
92 	struct xfs_dir2_leaf_entry *
93 		(*leaf_ents_p)(struct xfs_dir2_leaf *lp);
94 
95 	int	node_hdr_size;
96 	void	(*node_hdr_to_disk)(struct xfs_da_intnode *to,
97 				    struct xfs_da3_icnode_hdr *from);
98 	void	(*node_hdr_from_disk)(struct xfs_da3_icnode_hdr *to,
99 				      struct xfs_da_intnode *from);
100 	struct xfs_da_node_entry *
101 		(*node_tree_p)(struct xfs_da_intnode *dap);
102 
103 	int	free_hdr_size;
104 	void	(*free_hdr_to_disk)(struct xfs_dir2_free *to,
105 				    struct xfs_dir3_icfree_hdr *from);
106 	void	(*free_hdr_from_disk)(struct xfs_dir3_icfree_hdr *to,
107 				      struct xfs_dir2_free *from);
108 	int	(*free_max_bests)(struct xfs_da_geometry *geo);
109 	__be16 * (*free_bests_p)(struct xfs_dir2_free *free);
110 	xfs_dir2_db_t (*db_to_fdb)(struct xfs_da_geometry *geo,
111 				   xfs_dir2_db_t db);
112 	int	(*db_to_fdindex)(struct xfs_da_geometry *geo,
113 				 xfs_dir2_db_t db);
114 };
115 
116 extern const struct xfs_dir_ops *
117 	xfs_dir_get_ops(struct xfs_mount *mp, struct xfs_inode *dp);
118 extern const struct xfs_dir_ops *
119 	xfs_nondir_get_ops(struct xfs_mount *mp, struct xfs_inode *dp);
120 
121 /*
122  * Generic directory interface routines
123  */
124 extern void xfs_dir_startup(void);
125 extern int xfs_da_mount(struct xfs_mount *mp);
126 extern void xfs_da_unmount(struct xfs_mount *mp);
127 
128 extern int xfs_dir_isempty(struct xfs_inode *dp);
129 extern int xfs_dir_init(struct xfs_trans *tp, struct xfs_inode *dp,
130 				struct xfs_inode *pdp);
131 extern int xfs_dir_createname(struct xfs_trans *tp, struct xfs_inode *dp,
132 				struct xfs_name *name, xfs_ino_t inum,
133 				xfs_fsblock_t *first,
134 				struct xfs_defer_ops *dfops, xfs_extlen_t tot);
135 extern int xfs_dir_lookup(struct xfs_trans *tp, struct xfs_inode *dp,
136 				struct xfs_name *name, xfs_ino_t *inum,
137 				struct xfs_name *ci_name);
138 extern int xfs_dir_removename(struct xfs_trans *tp, struct xfs_inode *dp,
139 				struct xfs_name *name, xfs_ino_t ino,
140 				xfs_fsblock_t *first,
141 				struct xfs_defer_ops *dfops, xfs_extlen_t tot);
142 extern int xfs_dir_replace(struct xfs_trans *tp, struct xfs_inode *dp,
143 				struct xfs_name *name, xfs_ino_t inum,
144 				xfs_fsblock_t *first,
145 				struct xfs_defer_ops *dfops, xfs_extlen_t tot);
146 extern int xfs_dir_canenter(struct xfs_trans *tp, struct xfs_inode *dp,
147 				struct xfs_name *name);
148 
149 /*
150  * Direct call from the bmap code, bypassing the generic directory layer.
151  */
152 extern int xfs_dir2_sf_to_block(struct xfs_da_args *args);
153 
154 /*
155  * Interface routines used by userspace utilities
156  */
157 extern int xfs_dir2_isblock(struct xfs_da_args *args, int *r);
158 extern int xfs_dir2_isleaf(struct xfs_da_args *args, int *r);
159 extern int xfs_dir2_shrink_inode(struct xfs_da_args *args, xfs_dir2_db_t db,
160 				struct xfs_buf *bp);
161 
162 extern void xfs_dir2_data_freescan_int(struct xfs_da_geometry *geo,
163 		const struct xfs_dir_ops *ops,
164 		struct xfs_dir2_data_hdr *hdr, int *loghead);
165 extern void xfs_dir2_data_freescan(struct xfs_inode *dp,
166 		struct xfs_dir2_data_hdr *hdr, int *loghead);
167 extern void xfs_dir2_data_log_entry(struct xfs_da_args *args,
168 		struct xfs_buf *bp, struct xfs_dir2_data_entry *dep);
169 extern void xfs_dir2_data_log_header(struct xfs_da_args *args,
170 		struct xfs_buf *bp);
171 extern void xfs_dir2_data_log_unused(struct xfs_da_args *args,
172 		struct xfs_buf *bp, struct xfs_dir2_data_unused *dup);
173 extern void xfs_dir2_data_make_free(struct xfs_da_args *args,
174 		struct xfs_buf *bp, xfs_dir2_data_aoff_t offset,
175 		xfs_dir2_data_aoff_t len, int *needlogp, int *needscanp);
176 extern void xfs_dir2_data_use_free(struct xfs_da_args *args,
177 		struct xfs_buf *bp, struct xfs_dir2_data_unused *dup,
178 		xfs_dir2_data_aoff_t offset, xfs_dir2_data_aoff_t len,
179 		int *needlogp, int *needscanp);
180 
181 extern struct xfs_dir2_data_free *xfs_dir2_data_freefind(
182 		struct xfs_dir2_data_hdr *hdr, struct xfs_dir2_data_free *bf,
183 		struct xfs_dir2_data_unused *dup);
184 
185 extern int xfs_dir_ino_validate(struct xfs_mount *mp, xfs_ino_t ino);
186 
187 extern const struct xfs_buf_ops xfs_dir3_block_buf_ops;
188 extern const struct xfs_buf_ops xfs_dir3_leafn_buf_ops;
189 extern const struct xfs_buf_ops xfs_dir3_leaf1_buf_ops;
190 extern const struct xfs_buf_ops xfs_dir3_free_buf_ops;
191 extern const struct xfs_buf_ops xfs_dir3_data_buf_ops;
192 
193 /*
194  * Directory offset/block conversion functions.
195  *
196  * DB blocks here are logical directory block numbers, not filesystem blocks.
197  */
198 
199 /*
200  * Convert dataptr to byte in file space
201  */
202 static inline xfs_dir2_off_t
203 xfs_dir2_dataptr_to_byte(xfs_dir2_dataptr_t dp)
204 {
205 	return (xfs_dir2_off_t)dp << XFS_DIR2_DATA_ALIGN_LOG;
206 }
207 
208 /*
209  * Convert byte in file space to dataptr.  It had better be aligned.
210  */
211 static inline xfs_dir2_dataptr_t
212 xfs_dir2_byte_to_dataptr(xfs_dir2_off_t by)
213 {
214 	return (xfs_dir2_dataptr_t)(by >> XFS_DIR2_DATA_ALIGN_LOG);
215 }
216 
217 /*
218  * Convert byte in space to (DB) block
219  */
220 static inline xfs_dir2_db_t
221 xfs_dir2_byte_to_db(struct xfs_da_geometry *geo, xfs_dir2_off_t by)
222 {
223 	return (xfs_dir2_db_t)(by >> geo->blklog);
224 }
225 
226 /*
227  * Convert dataptr to a block number
228  */
229 static inline xfs_dir2_db_t
230 xfs_dir2_dataptr_to_db(struct xfs_da_geometry *geo, xfs_dir2_dataptr_t dp)
231 {
232 	return xfs_dir2_byte_to_db(geo, xfs_dir2_dataptr_to_byte(dp));
233 }
234 
235 /*
236  * Convert byte in space to offset in a block
237  */
238 static inline xfs_dir2_data_aoff_t
239 xfs_dir2_byte_to_off(struct xfs_da_geometry *geo, xfs_dir2_off_t by)
240 {
241 	return (xfs_dir2_data_aoff_t)(by & (geo->blksize - 1));
242 }
243 
244 /*
245  * Convert dataptr to a byte offset in a block
246  */
247 static inline xfs_dir2_data_aoff_t
248 xfs_dir2_dataptr_to_off(struct xfs_da_geometry *geo, xfs_dir2_dataptr_t dp)
249 {
250 	return xfs_dir2_byte_to_off(geo, xfs_dir2_dataptr_to_byte(dp));
251 }
252 
253 /*
254  * Convert block and offset to byte in space
255  */
256 static inline xfs_dir2_off_t
257 xfs_dir2_db_off_to_byte(struct xfs_da_geometry *geo, xfs_dir2_db_t db,
258 			xfs_dir2_data_aoff_t o)
259 {
260 	return ((xfs_dir2_off_t)db << geo->blklog) + o;
261 }
262 
263 /*
264  * Convert block (DB) to block (dablk)
265  */
266 static inline xfs_dablk_t
267 xfs_dir2_db_to_da(struct xfs_da_geometry *geo, xfs_dir2_db_t db)
268 {
269 	return (xfs_dablk_t)(db << (geo->blklog - geo->fsblog));
270 }
271 
272 /*
273  * Convert byte in space to (DA) block
274  */
275 static inline xfs_dablk_t
276 xfs_dir2_byte_to_da(struct xfs_da_geometry *geo, xfs_dir2_off_t by)
277 {
278 	return xfs_dir2_db_to_da(geo, xfs_dir2_byte_to_db(geo, by));
279 }
280 
281 /*
282  * Convert block and offset to dataptr
283  */
284 static inline xfs_dir2_dataptr_t
285 xfs_dir2_db_off_to_dataptr(struct xfs_da_geometry *geo, xfs_dir2_db_t db,
286 			   xfs_dir2_data_aoff_t o)
287 {
288 	return xfs_dir2_byte_to_dataptr(xfs_dir2_db_off_to_byte(geo, db, o));
289 }
290 
291 /*
292  * Convert block (dablk) to block (DB)
293  */
294 static inline xfs_dir2_db_t
295 xfs_dir2_da_to_db(struct xfs_da_geometry *geo, xfs_dablk_t da)
296 {
297 	return (xfs_dir2_db_t)(da >> (geo->blklog - geo->fsblog));
298 }
299 
300 /*
301  * Convert block (dablk) to byte offset in space
302  */
303 static inline xfs_dir2_off_t
304 xfs_dir2_da_to_byte(struct xfs_da_geometry *geo, xfs_dablk_t da)
305 {
306 	return xfs_dir2_db_off_to_byte(geo, xfs_dir2_da_to_db(geo, da), 0);
307 }
308 
309 /*
310  * Directory tail pointer accessor functions. Based on block geometry.
311  */
312 static inline struct xfs_dir2_block_tail *
313 xfs_dir2_block_tail_p(struct xfs_da_geometry *geo, struct xfs_dir2_data_hdr *hdr)
314 {
315 	return ((struct xfs_dir2_block_tail *)
316 		((char *)hdr + geo->blksize)) - 1;
317 }
318 
319 static inline struct xfs_dir2_leaf_tail *
320 xfs_dir2_leaf_tail_p(struct xfs_da_geometry *geo, struct xfs_dir2_leaf *lp)
321 {
322 	return (struct xfs_dir2_leaf_tail *)
323 		((char *)lp + geo->blksize -
324 		  sizeof(struct xfs_dir2_leaf_tail));
325 }
326 
327 /*
328  * The Linux API doesn't pass down the total size of the buffer
329  * we read into down to the filesystem.  With the filldir concept
330  * it's not needed for correct information, but the XFS dir2 leaf
331  * code wants an estimate of the buffer size to calculate it's
332  * readahead window and size the buffers used for mapping to
333  * physical blocks.
334  *
335  * Try to give it an estimate that's good enough, maybe at some
336  * point we can change the ->readdir prototype to include the
337  * buffer size.  For now we use the current glibc buffer size.
338  * musl libc hardcodes 2k and dietlibc uses PAGE_SIZE.
339  */
340 #define XFS_READDIR_BUFSIZE	(32768)
341 
342 unsigned char xfs_dir3_get_dtype(struct xfs_mount *mp, uint8_t filetype);
343 void *xfs_dir3_data_endp(struct xfs_da_geometry *geo,
344 		struct xfs_dir2_data_hdr *hdr);
345 
346 #endif	/* __XFS_DIR2_H__ */
347