xref: /openbmc/linux/fs/xfs/libxfs/xfs_dir2.h (revision adb57164)
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  * Generic directory interface routines
33  */
34 extern void xfs_dir_startup(void);
35 extern int xfs_da_mount(struct xfs_mount *mp);
36 extern void xfs_da_unmount(struct xfs_mount *mp);
37 
38 extern int xfs_dir_isempty(struct xfs_inode *dp);
39 extern int xfs_dir_init(struct xfs_trans *tp, struct xfs_inode *dp,
40 				struct xfs_inode *pdp);
41 extern int xfs_dir_createname(struct xfs_trans *tp, struct xfs_inode *dp,
42 				struct xfs_name *name, xfs_ino_t inum,
43 				xfs_extlen_t tot);
44 extern int xfs_dir_lookup(struct xfs_trans *tp, struct xfs_inode *dp,
45 				struct xfs_name *name, xfs_ino_t *inum,
46 				struct xfs_name *ci_name);
47 extern int xfs_dir_removename(struct xfs_trans *tp, struct xfs_inode *dp,
48 				struct xfs_name *name, xfs_ino_t ino,
49 				xfs_extlen_t tot);
50 extern bool xfs_dir2_sf_replace_needblock(struct xfs_inode *dp,
51 				xfs_ino_t inum);
52 extern int xfs_dir_replace(struct xfs_trans *tp, struct xfs_inode *dp,
53 				struct xfs_name *name, xfs_ino_t inum,
54 				xfs_extlen_t tot);
55 extern int xfs_dir_canenter(struct xfs_trans *tp, struct xfs_inode *dp,
56 				struct xfs_name *name);
57 
58 /*
59  * Direct call from the bmap code, bypassing the generic directory layer.
60  */
61 extern int xfs_dir2_sf_to_block(struct xfs_da_args *args);
62 
63 /*
64  * Interface routines used by userspace utilities
65  */
66 extern int xfs_dir2_isblock(struct xfs_da_args *args, int *r);
67 extern int xfs_dir2_isleaf(struct xfs_da_args *args, int *r);
68 extern int xfs_dir2_shrink_inode(struct xfs_da_args *args, xfs_dir2_db_t db,
69 				struct xfs_buf *bp);
70 
71 extern void xfs_dir2_data_freescan(struct xfs_mount *mp,
72 		struct xfs_dir2_data_hdr *hdr, int *loghead);
73 extern void xfs_dir2_data_log_entry(struct xfs_da_args *args,
74 		struct xfs_buf *bp, struct xfs_dir2_data_entry *dep);
75 extern void xfs_dir2_data_log_header(struct xfs_da_args *args,
76 		struct xfs_buf *bp);
77 extern void xfs_dir2_data_log_unused(struct xfs_da_args *args,
78 		struct xfs_buf *bp, struct xfs_dir2_data_unused *dup);
79 extern void xfs_dir2_data_make_free(struct xfs_da_args *args,
80 		struct xfs_buf *bp, xfs_dir2_data_aoff_t offset,
81 		xfs_dir2_data_aoff_t len, int *needlogp, int *needscanp);
82 extern int xfs_dir2_data_use_free(struct xfs_da_args *args,
83 		struct xfs_buf *bp, struct xfs_dir2_data_unused *dup,
84 		xfs_dir2_data_aoff_t offset, xfs_dir2_data_aoff_t len,
85 		int *needlogp, int *needscanp);
86 
87 extern struct xfs_dir2_data_free *xfs_dir2_data_freefind(
88 		struct xfs_dir2_data_hdr *hdr, struct xfs_dir2_data_free *bf,
89 		struct xfs_dir2_data_unused *dup);
90 
91 extern int xfs_dir_ino_validate(struct xfs_mount *mp, xfs_ino_t ino);
92 
93 extern const struct xfs_buf_ops xfs_dir3_block_buf_ops;
94 extern const struct xfs_buf_ops xfs_dir3_leafn_buf_ops;
95 extern const struct xfs_buf_ops xfs_dir3_leaf1_buf_ops;
96 extern const struct xfs_buf_ops xfs_dir3_free_buf_ops;
97 extern const struct xfs_buf_ops xfs_dir3_data_buf_ops;
98 
99 /*
100  * Directory offset/block conversion functions.
101  *
102  * DB blocks here are logical directory block numbers, not filesystem blocks.
103  */
104 
105 /*
106  * Convert dataptr to byte in file space
107  */
108 static inline xfs_dir2_off_t
109 xfs_dir2_dataptr_to_byte(xfs_dir2_dataptr_t dp)
110 {
111 	return (xfs_dir2_off_t)dp << XFS_DIR2_DATA_ALIGN_LOG;
112 }
113 
114 /*
115  * Convert byte in file space to dataptr.  It had better be aligned.
116  */
117 static inline xfs_dir2_dataptr_t
118 xfs_dir2_byte_to_dataptr(xfs_dir2_off_t by)
119 {
120 	return (xfs_dir2_dataptr_t)(by >> XFS_DIR2_DATA_ALIGN_LOG);
121 }
122 
123 /*
124  * Convert byte in space to (DB) block
125  */
126 static inline xfs_dir2_db_t
127 xfs_dir2_byte_to_db(struct xfs_da_geometry *geo, xfs_dir2_off_t by)
128 {
129 	return (xfs_dir2_db_t)(by >> geo->blklog);
130 }
131 
132 /*
133  * Convert dataptr to a block number
134  */
135 static inline xfs_dir2_db_t
136 xfs_dir2_dataptr_to_db(struct xfs_da_geometry *geo, xfs_dir2_dataptr_t dp)
137 {
138 	return xfs_dir2_byte_to_db(geo, xfs_dir2_dataptr_to_byte(dp));
139 }
140 
141 /*
142  * Convert byte in space to offset in a block
143  */
144 static inline xfs_dir2_data_aoff_t
145 xfs_dir2_byte_to_off(struct xfs_da_geometry *geo, xfs_dir2_off_t by)
146 {
147 	return (xfs_dir2_data_aoff_t)(by & (geo->blksize - 1));
148 }
149 
150 /*
151  * Convert dataptr to a byte offset in a block
152  */
153 static inline xfs_dir2_data_aoff_t
154 xfs_dir2_dataptr_to_off(struct xfs_da_geometry *geo, xfs_dir2_dataptr_t dp)
155 {
156 	return xfs_dir2_byte_to_off(geo, xfs_dir2_dataptr_to_byte(dp));
157 }
158 
159 /*
160  * Convert block and offset to byte in space
161  */
162 static inline xfs_dir2_off_t
163 xfs_dir2_db_off_to_byte(struct xfs_da_geometry *geo, xfs_dir2_db_t db,
164 			xfs_dir2_data_aoff_t o)
165 {
166 	return ((xfs_dir2_off_t)db << geo->blklog) + o;
167 }
168 
169 /*
170  * Convert block (DB) to block (dablk)
171  */
172 static inline xfs_dablk_t
173 xfs_dir2_db_to_da(struct xfs_da_geometry *geo, xfs_dir2_db_t db)
174 {
175 	return (xfs_dablk_t)(db << (geo->blklog - geo->fsblog));
176 }
177 
178 /*
179  * Convert byte in space to (DA) block
180  */
181 static inline xfs_dablk_t
182 xfs_dir2_byte_to_da(struct xfs_da_geometry *geo, xfs_dir2_off_t by)
183 {
184 	return xfs_dir2_db_to_da(geo, xfs_dir2_byte_to_db(geo, by));
185 }
186 
187 /*
188  * Convert block and offset to dataptr
189  */
190 static inline xfs_dir2_dataptr_t
191 xfs_dir2_db_off_to_dataptr(struct xfs_da_geometry *geo, xfs_dir2_db_t db,
192 			   xfs_dir2_data_aoff_t o)
193 {
194 	return xfs_dir2_byte_to_dataptr(xfs_dir2_db_off_to_byte(geo, db, o));
195 }
196 
197 /*
198  * Convert block (dablk) to block (DB)
199  */
200 static inline xfs_dir2_db_t
201 xfs_dir2_da_to_db(struct xfs_da_geometry *geo, xfs_dablk_t da)
202 {
203 	return (xfs_dir2_db_t)(da >> (geo->blklog - geo->fsblog));
204 }
205 
206 /*
207  * Convert block (dablk) to byte offset in space
208  */
209 static inline xfs_dir2_off_t
210 xfs_dir2_da_to_byte(struct xfs_da_geometry *geo, xfs_dablk_t da)
211 {
212 	return xfs_dir2_db_off_to_byte(geo, xfs_dir2_da_to_db(geo, da), 0);
213 }
214 
215 /*
216  * Directory tail pointer accessor functions. Based on block geometry.
217  */
218 static inline struct xfs_dir2_block_tail *
219 xfs_dir2_block_tail_p(struct xfs_da_geometry *geo, struct xfs_dir2_data_hdr *hdr)
220 {
221 	return ((struct xfs_dir2_block_tail *)
222 		((char *)hdr + geo->blksize)) - 1;
223 }
224 
225 static inline struct xfs_dir2_leaf_tail *
226 xfs_dir2_leaf_tail_p(struct xfs_da_geometry *geo, struct xfs_dir2_leaf *lp)
227 {
228 	return (struct xfs_dir2_leaf_tail *)
229 		((char *)lp + geo->blksize -
230 		  sizeof(struct xfs_dir2_leaf_tail));
231 }
232 
233 /*
234  * The Linux API doesn't pass down the total size of the buffer
235  * we read into down to the filesystem.  With the filldir concept
236  * it's not needed for correct information, but the XFS dir2 leaf
237  * code wants an estimate of the buffer size to calculate it's
238  * readahead window and size the buffers used for mapping to
239  * physical blocks.
240  *
241  * Try to give it an estimate that's good enough, maybe at some
242  * point we can change the ->readdir prototype to include the
243  * buffer size.  For now we use the current glibc buffer size.
244  * musl libc hardcodes 2k and dietlibc uses PAGE_SIZE.
245  */
246 #define XFS_READDIR_BUFSIZE	(32768)
247 
248 unsigned char xfs_dir3_get_dtype(struct xfs_mount *mp, uint8_t filetype);
249 unsigned int xfs_dir3_data_end_offset(struct xfs_da_geometry *geo,
250 		struct xfs_dir2_data_hdr *hdr);
251 bool xfs_dir2_namecheck(const void *name, size_t length);
252 
253 #endif	/* __XFS_DIR2_H__ */
254