xref: /linux/fs/xfs/libxfs/xfs_dir2.h (revision da5b2ad1c2f18834cb1ce429e2e5a5cf5cbdf21b)
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 const struct xfs_name	xfs_name_dotdot;
25 extern const struct xfs_name	xfs_name_dot;
26 
27 static inline bool
28 xfs_dir2_samename(
29 	const struct xfs_name	*n1,
30 	const struct xfs_name	*n2)
31 {
32 	if (n1 == n2)
33 		return true;
34 	if (n1->len != n2->len)
35 		return false;
36 	return !memcmp(n1->name, n2->name, n1->len);
37 }
38 
39 enum xfs_dir2_fmt {
40 	XFS_DIR2_FMT_SF,
41 	XFS_DIR2_FMT_BLOCK,
42 	XFS_DIR2_FMT_LEAF,
43 	XFS_DIR2_FMT_NODE,
44 	XFS_DIR2_FMT_ERROR,
45 };
46 
47 enum xfs_dir2_fmt xfs_dir2_format(struct xfs_da_args *args, int *error);
48 
49 /*
50  * Convert inode mode to directory entry filetype
51  */
52 extern unsigned char xfs_mode_to_ftype(int mode);
53 
54 /*
55  * Generic directory interface routines
56  */
57 extern void xfs_dir_startup(void);
58 extern int xfs_da_mount(struct xfs_mount *mp);
59 extern void xfs_da_unmount(struct xfs_mount *mp);
60 
61 extern int xfs_dir_isempty(struct xfs_inode *dp);
62 extern int xfs_dir_init(struct xfs_trans *tp, struct xfs_inode *dp,
63 				struct xfs_inode *pdp);
64 extern int xfs_dir_createname(struct xfs_trans *tp, struct xfs_inode *dp,
65 				const struct xfs_name *name, xfs_ino_t inum,
66 				xfs_extlen_t tot);
67 extern int xfs_dir_lookup(struct xfs_trans *tp, struct xfs_inode *dp,
68 				const struct xfs_name *name, xfs_ino_t *inum,
69 				struct xfs_name *ci_name);
70 extern int xfs_dir_removename(struct xfs_trans *tp, struct xfs_inode *dp,
71 				const struct xfs_name *name, xfs_ino_t ino,
72 				xfs_extlen_t tot);
73 extern int xfs_dir_replace(struct xfs_trans *tp, struct xfs_inode *dp,
74 				const struct xfs_name *name, xfs_ino_t inum,
75 				xfs_extlen_t tot);
76 extern int xfs_dir_canenter(struct xfs_trans *tp, struct xfs_inode *dp,
77 				const struct xfs_name *name);
78 
79 int xfs_dir_lookup_args(struct xfs_da_args *args);
80 int xfs_dir_createname_args(struct xfs_da_args *args);
81 int xfs_dir_removename_args(struct xfs_da_args *args);
82 int xfs_dir_replace_args(struct xfs_da_args *args);
83 
84 /*
85  * Direct call from the bmap code, bypassing the generic directory layer.
86  */
87 extern int xfs_dir2_sf_to_block(struct xfs_da_args *args);
88 
89 /*
90  * Interface routines used by userspace utilities
91  */
92 extern int xfs_dir2_shrink_inode(struct xfs_da_args *args, xfs_dir2_db_t db,
93 				struct xfs_buf *bp);
94 
95 extern void xfs_dir2_data_freescan(struct xfs_mount *mp,
96 		struct xfs_dir2_data_hdr *hdr, int *loghead);
97 extern void xfs_dir2_data_log_entry(struct xfs_da_args *args,
98 		struct xfs_buf *bp, struct xfs_dir2_data_entry *dep);
99 extern void xfs_dir2_data_log_header(struct xfs_da_args *args,
100 		struct xfs_buf *bp);
101 extern void xfs_dir2_data_log_unused(struct xfs_da_args *args,
102 		struct xfs_buf *bp, struct xfs_dir2_data_unused *dup);
103 extern void xfs_dir2_data_make_free(struct xfs_da_args *args,
104 		struct xfs_buf *bp, xfs_dir2_data_aoff_t offset,
105 		xfs_dir2_data_aoff_t len, int *needlogp, int *needscanp);
106 extern int xfs_dir2_data_use_free(struct xfs_da_args *args,
107 		struct xfs_buf *bp, struct xfs_dir2_data_unused *dup,
108 		xfs_dir2_data_aoff_t offset, xfs_dir2_data_aoff_t len,
109 		int *needlogp, int *needscanp);
110 
111 extern struct xfs_dir2_data_free *xfs_dir2_data_freefind(
112 		struct xfs_dir2_data_hdr *hdr, struct xfs_dir2_data_free *bf,
113 		struct xfs_dir2_data_unused *dup);
114 
115 extern int xfs_dir_ino_validate(struct xfs_mount *mp, xfs_ino_t ino);
116 
117 xfs_failaddr_t xfs_dir3_leaf_header_check(struct xfs_buf *bp, xfs_ino_t owner);
118 xfs_failaddr_t xfs_dir3_data_header_check(struct xfs_buf *bp, xfs_ino_t owner);
119 xfs_failaddr_t xfs_dir3_block_header_check(struct xfs_buf *bp, xfs_ino_t owner);
120 
121 extern const struct xfs_buf_ops xfs_dir3_block_buf_ops;
122 extern const struct xfs_buf_ops xfs_dir3_leafn_buf_ops;
123 extern const struct xfs_buf_ops xfs_dir3_leaf1_buf_ops;
124 extern const struct xfs_buf_ops xfs_dir3_free_buf_ops;
125 extern const struct xfs_buf_ops xfs_dir3_data_buf_ops;
126 
127 /*
128  * Directory offset/block conversion functions.
129  *
130  * DB blocks here are logical directory block numbers, not filesystem blocks.
131  */
132 
133 /*
134  * Convert dataptr to byte in file space
135  */
136 static inline xfs_dir2_off_t
137 xfs_dir2_dataptr_to_byte(xfs_dir2_dataptr_t dp)
138 {
139 	return (xfs_dir2_off_t)dp << XFS_DIR2_DATA_ALIGN_LOG;
140 }
141 
142 /*
143  * Convert byte in file space to dataptr.  It had better be aligned.
144  */
145 static inline xfs_dir2_dataptr_t
146 xfs_dir2_byte_to_dataptr(xfs_dir2_off_t by)
147 {
148 	return (xfs_dir2_dataptr_t)(by >> XFS_DIR2_DATA_ALIGN_LOG);
149 }
150 
151 /*
152  * Convert byte in space to (DB) block
153  */
154 static inline xfs_dir2_db_t
155 xfs_dir2_byte_to_db(struct xfs_da_geometry *geo, xfs_dir2_off_t by)
156 {
157 	return (xfs_dir2_db_t)(by >> geo->blklog);
158 }
159 
160 /*
161  * Convert dataptr to a block number
162  */
163 static inline xfs_dir2_db_t
164 xfs_dir2_dataptr_to_db(struct xfs_da_geometry *geo, xfs_dir2_dataptr_t dp)
165 {
166 	return xfs_dir2_byte_to_db(geo, xfs_dir2_dataptr_to_byte(dp));
167 }
168 
169 /*
170  * Convert byte in space to offset in a block
171  */
172 static inline xfs_dir2_data_aoff_t
173 xfs_dir2_byte_to_off(struct xfs_da_geometry *geo, xfs_dir2_off_t by)
174 {
175 	return (xfs_dir2_data_aoff_t)(by & (geo->blksize - 1));
176 }
177 
178 /*
179  * Convert dataptr to a byte offset in a block
180  */
181 static inline xfs_dir2_data_aoff_t
182 xfs_dir2_dataptr_to_off(struct xfs_da_geometry *geo, xfs_dir2_dataptr_t dp)
183 {
184 	return xfs_dir2_byte_to_off(geo, xfs_dir2_dataptr_to_byte(dp));
185 }
186 
187 /*
188  * Convert block and offset to byte in space
189  */
190 static inline xfs_dir2_off_t
191 xfs_dir2_db_off_to_byte(struct xfs_da_geometry *geo, xfs_dir2_db_t db,
192 			xfs_dir2_data_aoff_t o)
193 {
194 	return ((xfs_dir2_off_t)db << geo->blklog) + o;
195 }
196 
197 /*
198  * Convert block (DB) to block (dablk)
199  */
200 static inline xfs_dablk_t
201 xfs_dir2_db_to_da(struct xfs_da_geometry *geo, xfs_dir2_db_t db)
202 {
203 	return (xfs_dablk_t)(db << (geo->blklog - geo->fsblog));
204 }
205 
206 /*
207  * Convert byte in space to (DA) block
208  */
209 static inline xfs_dablk_t
210 xfs_dir2_byte_to_da(struct xfs_da_geometry *geo, xfs_dir2_off_t by)
211 {
212 	return xfs_dir2_db_to_da(geo, xfs_dir2_byte_to_db(geo, by));
213 }
214 
215 /*
216  * Convert block and offset to dataptr
217  */
218 static inline xfs_dir2_dataptr_t
219 xfs_dir2_db_off_to_dataptr(struct xfs_da_geometry *geo, xfs_dir2_db_t db,
220 			   xfs_dir2_data_aoff_t o)
221 {
222 	return xfs_dir2_byte_to_dataptr(xfs_dir2_db_off_to_byte(geo, db, o));
223 }
224 
225 /*
226  * Convert block (dablk) to block (DB)
227  */
228 static inline xfs_dir2_db_t
229 xfs_dir2_da_to_db(struct xfs_da_geometry *geo, xfs_dablk_t da)
230 {
231 	return (xfs_dir2_db_t)(da >> (geo->blklog - geo->fsblog));
232 }
233 
234 /*
235  * Convert block (dablk) to byte offset in space
236  */
237 static inline xfs_dir2_off_t
238 xfs_dir2_da_to_byte(struct xfs_da_geometry *geo, xfs_dablk_t da)
239 {
240 	return xfs_dir2_db_off_to_byte(geo, xfs_dir2_da_to_db(geo, da), 0);
241 }
242 
243 /*
244  * Directory tail pointer accessor functions. Based on block geometry.
245  */
246 static inline struct xfs_dir2_block_tail *
247 xfs_dir2_block_tail_p(struct xfs_da_geometry *geo, struct xfs_dir2_data_hdr *hdr)
248 {
249 	return ((struct xfs_dir2_block_tail *)
250 		((char *)hdr + geo->blksize)) - 1;
251 }
252 
253 static inline struct xfs_dir2_leaf_tail *
254 xfs_dir2_leaf_tail_p(struct xfs_da_geometry *geo, struct xfs_dir2_leaf *lp)
255 {
256 	return (struct xfs_dir2_leaf_tail *)
257 		((char *)lp + geo->blksize -
258 		  sizeof(struct xfs_dir2_leaf_tail));
259 }
260 
261 /*
262  * The Linux API doesn't pass down the total size of the buffer
263  * we read into down to the filesystem.  With the filldir concept
264  * it's not needed for correct information, but the XFS dir2 leaf
265  * code wants an estimate of the buffer size to calculate it's
266  * readahead window and size the buffers used for mapping to
267  * physical blocks.
268  *
269  * Try to give it an estimate that's good enough, maybe at some
270  * point we can change the ->readdir prototype to include the
271  * buffer size.  For now we use the current glibc buffer size.
272  * musl libc hardcodes 2k and dietlibc uses PAGE_SIZE.
273  */
274 #define XFS_READDIR_BUFSIZE	(32768)
275 
276 unsigned char xfs_dir3_get_dtype(struct xfs_mount *mp, uint8_t filetype);
277 unsigned int xfs_dir3_data_end_offset(struct xfs_da_geometry *geo,
278 		struct xfs_dir2_data_hdr *hdr);
279 bool xfs_dir2_namecheck(const void *name, size_t length);
280 
281 /*
282  * The "ascii-ci" feature was created to speed up case-insensitive lookups for
283  * a Samba product.  Because of the inherent problems with CI and UTF-8
284  * encoding, etc, it was decided that Samba would be configured to export
285  * latin1/iso 8859-1 encodings as that covered >90% of the target markets for
286  * the product.  Hence the "ascii-ci" casefolding code could be encoded into
287  * the XFS directory operations and remove all the overhead of casefolding from
288  * Samba.
289  *
290  * To provide consistent hashing behavior between the userspace and kernel,
291  * these functions prepare names for hashing by transforming specific bytes
292  * to other bytes.  Robustness with other encodings is not guaranteed.
293  */
294 static inline bool xfs_ascii_ci_need_xfrm(unsigned char c)
295 {
296 	if (c >= 0x41 && c <= 0x5a)	/* A-Z */
297 		return true;
298 	if (c >= 0xc0 && c <= 0xd6)	/* latin A-O with accents */
299 		return true;
300 	if (c >= 0xd8 && c <= 0xde)	/* latin O-Y with accents */
301 		return true;
302 	return false;
303 }
304 
305 static inline unsigned char xfs_ascii_ci_xfrm(unsigned char c)
306 {
307 	if (xfs_ascii_ci_need_xfrm(c))
308 		c -= 'A' - 'a';
309 	return c;
310 }
311 
312 struct xfs_dir_update_params {
313 	const struct xfs_inode	*dp;
314 	const struct xfs_inode	*ip;
315 	const struct xfs_name	*name;
316 	int			delta;
317 };
318 
319 #ifdef CONFIG_XFS_LIVE_HOOKS
320 void xfs_dir_update_hook(struct xfs_inode *dp, struct xfs_inode *ip,
321 		int delta, const struct xfs_name *name);
322 
323 struct xfs_dir_hook {
324 	struct xfs_hook		dirent_hook;
325 };
326 
327 void xfs_dir_hook_disable(void);
328 void xfs_dir_hook_enable(void);
329 
330 int xfs_dir_hook_add(struct xfs_mount *mp, struct xfs_dir_hook *hook);
331 void xfs_dir_hook_del(struct xfs_mount *mp, struct xfs_dir_hook *hook);
332 void xfs_dir_hook_setup(struct xfs_dir_hook *hook, notifier_fn_t mod_fn);
333 #else
334 # define xfs_dir_update_hook(dp, ip, delta, name)	((void)0)
335 #endif /* CONFIG_XFS_LIVE_HOOKS */
336 
337 struct xfs_parent_args;
338 
339 struct xfs_dir_update {
340 	struct xfs_inode	*dp;
341 	const struct xfs_name	*name;
342 	struct xfs_inode	*ip;
343 	struct xfs_parent_args	*ppargs;
344 };
345 
346 int xfs_dir_create_child(struct xfs_trans *tp, unsigned int resblks,
347 		struct xfs_dir_update *du);
348 int xfs_dir_add_child(struct xfs_trans *tp, unsigned int resblks,
349 		struct xfs_dir_update *du);
350 int xfs_dir_remove_child(struct xfs_trans *tp, unsigned int resblks,
351 		struct xfs_dir_update *du);
352 
353 int xfs_dir_exchange_children(struct xfs_trans *tp, struct xfs_dir_update *du1,
354 		struct xfs_dir_update *du2, unsigned int spaceres);
355 int xfs_dir_rename_children(struct xfs_trans *tp, struct xfs_dir_update *du_src,
356 		struct xfs_dir_update *du_tgt, unsigned int spaceres,
357 		struct xfs_dir_update *du_wip);
358 
359 #endif	/* __XFS_DIR2_H__ */
360