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
12struct xfs_da_args;
13struct xfs_inode;
14struct xfs_mount;
15struct xfs_trans;
16struct xfs_dir2_sf_hdr;
17struct xfs_dir2_sf_entry;
18struct xfs_dir2_data_hdr;
19struct xfs_dir2_data_entry;
20struct xfs_dir2_data_unused;
21struct xfs_dir3_icfree_hdr;
22struct xfs_dir3_icleaf_hdr;
23
24extern const struct xfs_name	xfs_name_dotdot;
25extern const struct xfs_name	xfs_name_dot;
26
27static inline bool
28xfs_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/*
40 * Convert inode mode to directory entry filetype
41 */
42extern unsigned char xfs_mode_to_ftype(int mode);
43
44/*
45 * Generic directory interface routines
46 */
47extern void xfs_dir_startup(void);
48extern int xfs_da_mount(struct xfs_mount *mp);
49extern void xfs_da_unmount(struct xfs_mount *mp);
50
51extern int xfs_dir_isempty(struct xfs_inode *dp);
52extern int xfs_dir_init(struct xfs_trans *tp, struct xfs_inode *dp,
53				struct xfs_inode *pdp);
54extern int xfs_dir_createname(struct xfs_trans *tp, struct xfs_inode *dp,
55				const struct xfs_name *name, xfs_ino_t inum,
56				xfs_extlen_t tot);
57extern int xfs_dir_lookup(struct xfs_trans *tp, struct xfs_inode *dp,
58				const struct xfs_name *name, xfs_ino_t *inum,
59				struct xfs_name *ci_name);
60extern int xfs_dir_removename(struct xfs_trans *tp, struct xfs_inode *dp,
61				struct xfs_name *name, xfs_ino_t ino,
62				xfs_extlen_t tot);
63extern int xfs_dir_replace(struct xfs_trans *tp, struct xfs_inode *dp,
64				const struct xfs_name *name, xfs_ino_t inum,
65				xfs_extlen_t tot);
66extern int xfs_dir_canenter(struct xfs_trans *tp, struct xfs_inode *dp,
67				struct xfs_name *name);
68
69/*
70 * Direct call from the bmap code, bypassing the generic directory layer.
71 */
72extern int xfs_dir2_sf_to_block(struct xfs_da_args *args);
73
74/*
75 * Interface routines used by userspace utilities
76 */
77extern int xfs_dir2_isblock(struct xfs_da_args *args, bool *isblock);
78extern int xfs_dir2_isleaf(struct xfs_da_args *args, bool *isleaf);
79extern int xfs_dir2_shrink_inode(struct xfs_da_args *args, xfs_dir2_db_t db,
80				struct xfs_buf *bp);
81
82extern void xfs_dir2_data_freescan(struct xfs_mount *mp,
83		struct xfs_dir2_data_hdr *hdr, int *loghead);
84extern void xfs_dir2_data_log_entry(struct xfs_da_args *args,
85		struct xfs_buf *bp, struct xfs_dir2_data_entry *dep);
86extern void xfs_dir2_data_log_header(struct xfs_da_args *args,
87		struct xfs_buf *bp);
88extern void xfs_dir2_data_log_unused(struct xfs_da_args *args,
89		struct xfs_buf *bp, struct xfs_dir2_data_unused *dup);
90extern void xfs_dir2_data_make_free(struct xfs_da_args *args,
91		struct xfs_buf *bp, xfs_dir2_data_aoff_t offset,
92		xfs_dir2_data_aoff_t len, int *needlogp, int *needscanp);
93extern int xfs_dir2_data_use_free(struct xfs_da_args *args,
94		struct xfs_buf *bp, struct xfs_dir2_data_unused *dup,
95		xfs_dir2_data_aoff_t offset, xfs_dir2_data_aoff_t len,
96		int *needlogp, int *needscanp);
97
98extern struct xfs_dir2_data_free *xfs_dir2_data_freefind(
99		struct xfs_dir2_data_hdr *hdr, struct xfs_dir2_data_free *bf,
100		struct xfs_dir2_data_unused *dup);
101
102extern int xfs_dir_ino_validate(struct xfs_mount *mp, xfs_ino_t ino);
103
104extern const struct xfs_buf_ops xfs_dir3_block_buf_ops;
105extern const struct xfs_buf_ops xfs_dir3_leafn_buf_ops;
106extern const struct xfs_buf_ops xfs_dir3_leaf1_buf_ops;
107extern const struct xfs_buf_ops xfs_dir3_free_buf_ops;
108extern const struct xfs_buf_ops xfs_dir3_data_buf_ops;
109
110/*
111 * Directory offset/block conversion functions.
112 *
113 * DB blocks here are logical directory block numbers, not filesystem blocks.
114 */
115
116/*
117 * Convert dataptr to byte in file space
118 */
119static inline xfs_dir2_off_t
120xfs_dir2_dataptr_to_byte(xfs_dir2_dataptr_t dp)
121{
122	return (xfs_dir2_off_t)dp << XFS_DIR2_DATA_ALIGN_LOG;
123}
124
125/*
126 * Convert byte in file space to dataptr.  It had better be aligned.
127 */
128static inline xfs_dir2_dataptr_t
129xfs_dir2_byte_to_dataptr(xfs_dir2_off_t by)
130{
131	return (xfs_dir2_dataptr_t)(by >> XFS_DIR2_DATA_ALIGN_LOG);
132}
133
134/*
135 * Convert byte in space to (DB) block
136 */
137static inline xfs_dir2_db_t
138xfs_dir2_byte_to_db(struct xfs_da_geometry *geo, xfs_dir2_off_t by)
139{
140	return (xfs_dir2_db_t)(by >> geo->blklog);
141}
142
143/*
144 * Convert dataptr to a block number
145 */
146static inline xfs_dir2_db_t
147xfs_dir2_dataptr_to_db(struct xfs_da_geometry *geo, xfs_dir2_dataptr_t dp)
148{
149	return xfs_dir2_byte_to_db(geo, xfs_dir2_dataptr_to_byte(dp));
150}
151
152/*
153 * Convert byte in space to offset in a block
154 */
155static inline xfs_dir2_data_aoff_t
156xfs_dir2_byte_to_off(struct xfs_da_geometry *geo, xfs_dir2_off_t by)
157{
158	return (xfs_dir2_data_aoff_t)(by & (geo->blksize - 1));
159}
160
161/*
162 * Convert dataptr to a byte offset in a block
163 */
164static inline xfs_dir2_data_aoff_t
165xfs_dir2_dataptr_to_off(struct xfs_da_geometry *geo, xfs_dir2_dataptr_t dp)
166{
167	return xfs_dir2_byte_to_off(geo, xfs_dir2_dataptr_to_byte(dp));
168}
169
170/*
171 * Convert block and offset to byte in space
172 */
173static inline xfs_dir2_off_t
174xfs_dir2_db_off_to_byte(struct xfs_da_geometry *geo, xfs_dir2_db_t db,
175			xfs_dir2_data_aoff_t o)
176{
177	return ((xfs_dir2_off_t)db << geo->blklog) + o;
178}
179
180/*
181 * Convert block (DB) to block (dablk)
182 */
183static inline xfs_dablk_t
184xfs_dir2_db_to_da(struct xfs_da_geometry *geo, xfs_dir2_db_t db)
185{
186	return (xfs_dablk_t)(db << (geo->blklog - geo->fsblog));
187}
188
189/*
190 * Convert byte in space to (DA) block
191 */
192static inline xfs_dablk_t
193xfs_dir2_byte_to_da(struct xfs_da_geometry *geo, xfs_dir2_off_t by)
194{
195	return xfs_dir2_db_to_da(geo, xfs_dir2_byte_to_db(geo, by));
196}
197
198/*
199 * Convert block and offset to dataptr
200 */
201static inline xfs_dir2_dataptr_t
202xfs_dir2_db_off_to_dataptr(struct xfs_da_geometry *geo, xfs_dir2_db_t db,
203			   xfs_dir2_data_aoff_t o)
204{
205	return xfs_dir2_byte_to_dataptr(xfs_dir2_db_off_to_byte(geo, db, o));
206}
207
208/*
209 * Convert block (dablk) to block (DB)
210 */
211static inline xfs_dir2_db_t
212xfs_dir2_da_to_db(struct xfs_da_geometry *geo, xfs_dablk_t da)
213{
214	return (xfs_dir2_db_t)(da >> (geo->blklog - geo->fsblog));
215}
216
217/*
218 * Convert block (dablk) to byte offset in space
219 */
220static inline xfs_dir2_off_t
221xfs_dir2_da_to_byte(struct xfs_da_geometry *geo, xfs_dablk_t da)
222{
223	return xfs_dir2_db_off_to_byte(geo, xfs_dir2_da_to_db(geo, da), 0);
224}
225
226/*
227 * Directory tail pointer accessor functions. Based on block geometry.
228 */
229static inline struct xfs_dir2_block_tail *
230xfs_dir2_block_tail_p(struct xfs_da_geometry *geo, struct xfs_dir2_data_hdr *hdr)
231{
232	return ((struct xfs_dir2_block_tail *)
233		((char *)hdr + geo->blksize)) - 1;
234}
235
236static inline struct xfs_dir2_leaf_tail *
237xfs_dir2_leaf_tail_p(struct xfs_da_geometry *geo, struct xfs_dir2_leaf *lp)
238{
239	return (struct xfs_dir2_leaf_tail *)
240		((char *)lp + geo->blksize -
241		  sizeof(struct xfs_dir2_leaf_tail));
242}
243
244/*
245 * The Linux API doesn't pass down the total size of the buffer
246 * we read into down to the filesystem.  With the filldir concept
247 * it's not needed for correct information, but the XFS dir2 leaf
248 * code wants an estimate of the buffer size to calculate it's
249 * readahead window and size the buffers used for mapping to
250 * physical blocks.
251 *
252 * Try to give it an estimate that's good enough, maybe at some
253 * point we can change the ->readdir prototype to include the
254 * buffer size.  For now we use the current glibc buffer size.
255 * musl libc hardcodes 2k and dietlibc uses PAGE_SIZE.
256 */
257#define XFS_READDIR_BUFSIZE	(32768)
258
259unsigned char xfs_dir3_get_dtype(struct xfs_mount *mp, uint8_t filetype);
260unsigned int xfs_dir3_data_end_offset(struct xfs_da_geometry *geo,
261		struct xfs_dir2_data_hdr *hdr);
262bool xfs_dir2_namecheck(const void *name, size_t length);
263
264/*
265 * The "ascii-ci" feature was created to speed up case-insensitive lookups for
266 * a Samba product.  Because of the inherent problems with CI and UTF-8
267 * encoding, etc, it was decided that Samba would be configured to export
268 * latin1/iso 8859-1 encodings as that covered >90% of the target markets for
269 * the product.  Hence the "ascii-ci" casefolding code could be encoded into
270 * the XFS directory operations and remove all the overhead of casefolding from
271 * Samba.
272 *
273 * To provide consistent hashing behavior between the userspace and kernel,
274 * these functions prepare names for hashing by transforming specific bytes
275 * to other bytes.  Robustness with other encodings is not guaranteed.
276 */
277static inline bool xfs_ascii_ci_need_xfrm(unsigned char c)
278{
279	if (c >= 0x41 && c <= 0x5a)	/* A-Z */
280		return true;
281	if (c >= 0xc0 && c <= 0xd6)	/* latin A-O with accents */
282		return true;
283	if (c >= 0xd8 && c <= 0xde)	/* latin O-Y with accents */
284		return true;
285	return false;
286}
287
288static inline unsigned char xfs_ascii_ci_xfrm(unsigned char c)
289{
290	if (xfs_ascii_ci_need_xfrm(c))
291		c -= 'A' - 'a';
292	return c;
293}
294
295#endif	/* __XFS_DIR2_H__ */
296