1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3 * This file is part of UBIFS.
4 *
5 * Copyright (C) 2006-2008 Nokia Corporation
6 *
7 * Authors: Artem Bityutskiy (Битюцкий Артём)
8 * Adrian Hunter
9 */
10
11 /*
12 * This file contains miscellaneous helper functions.
13 */
14
15 #ifndef __UBIFS_MISC_H__
16 #define __UBIFS_MISC_H__
17
18 /**
19 * ubifs_zn_dirty - check if znode is dirty.
20 * @znode: znode to check
21 *
22 * This helper function returns %1 if @znode is dirty and %0 otherwise.
23 */
24 static inline int ubifs_zn_dirty(const struct ubifs_znode *znode)
25 {
26 return !!test_bit(DIRTY_ZNODE, &znode->flags);
27 }
28
29 /**
30 * ubifs_zn_obsolete - check if znode is obsolete.
31 * @znode: znode to check
32 *
33 * This helper function returns %1 if @znode is obsolete and %0 otherwise.
34 */
35 static inline int ubifs_zn_obsolete(const struct ubifs_znode *znode)
36 {
37 return !!test_bit(OBSOLETE_ZNODE, &znode->flags);
38 }
39
40 /**
41 * ubifs_zn_cow - check if znode has to be copied on write.
42 * @znode: znode to check
43 *
44 * This helper function returns %1 if @znode is has COW flag set and %0
45 * otherwise.
46 */
47 static inline int ubifs_zn_cow(const struct ubifs_znode *znode)
48 {
49 return !!test_bit(COW_ZNODE, &znode->flags);
50 }
51
52 /**
53 * ubifs_wake_up_bgt - wake up background thread.
54 * @c: UBIFS file-system description object
55 */
56 static inline void ubifs_wake_up_bgt(struct ubifs_info *c)
57 {
58 if (c->bgt && !c->need_bgt) {
59 c->need_bgt = 1;
60 wake_up_process(c->bgt);
61 }
62 }
63
64 /**
65 * ubifs_tnc_find_child - find next child in znode.
66 * @znode: znode to search at
67 * @start: the zbranch index to start at
68 *
69 * This helper function looks for znode child starting at index @start. Returns
70 * the child or %NULL if no children were found.
71 */
72 static inline struct ubifs_znode *
73 ubifs_tnc_find_child(struct ubifs_znode *znode, int start)
74 {
75 while (start < znode->child_cnt) {
76 if (znode->zbranch[start].znode)
77 return znode->zbranch[start].znode;
78 start += 1;
79 }
80
81 return NULL;
82 }
83
84 /**
85 * ubifs_inode - get UBIFS inode information by VFS 'struct inode' object.
86 * @inode: the VFS 'struct inode' pointer
87 */
88 static inline struct ubifs_inode *ubifs_inode(const struct inode *inode)
89 {
90 return container_of(inode, struct ubifs_inode, vfs_inode);
91 }
92
93 /**
94 * ubifs_compr_present - check if compressor was compiled in.
95 * @compr_type: compressor type to check
96 * @c: the UBIFS file-system description object
97 *
98 * This function returns %1 of compressor of type @compr_type is present, and
99 * %0 if not.
100 */
101 static inline int ubifs_compr_present(struct ubifs_info *c, int compr_type)
102 {
103 ubifs_assert(c, compr_type >= 0 && compr_type < UBIFS_COMPR_TYPES_CNT);
104 return !!ubifs_compressors[compr_type]->capi_name;
105 }
106
107 /**
108 * ubifs_compr_name - get compressor name string by its type.
109 * @compr_type: compressor type
110 * @c: the UBIFS file-system description object
111 *
112 * This function returns compressor type string.
113 */
114 static inline const char *ubifs_compr_name(struct ubifs_info *c, int compr_type)
115 {
116 ubifs_assert(c, compr_type >= 0 && compr_type < UBIFS_COMPR_TYPES_CNT);
117 return ubifs_compressors[compr_type]->name;
118 }
119
120 /**
121 * ubifs_wbuf_sync - synchronize write-buffer.
122 * @wbuf: write-buffer to synchronize
123 *
124 * This is the same as 'ubifs_wbuf_sync_nolock()' but it does not assume
125 * that the write-buffer is already locked.
126 */
127 static inline int ubifs_wbuf_sync(struct ubifs_wbuf *wbuf)
128 {
129 int err;
130
131 mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead);
132 err = ubifs_wbuf_sync_nolock(wbuf);
133 mutex_unlock(&wbuf->io_mutex);
134 return err;
135 }
136
137 /**
138 * ubifs_encode_dev - encode device node IDs.
139 * @dev: UBIFS device node information
140 * @rdev: device IDs to encode
141 *
142 * This is a helper function which encodes major/minor numbers of a device node
143 * into UBIFS device node description. We use standard Linux "new" and "huge"
144 * encodings.
145 */
146 static inline int ubifs_encode_dev(union ubifs_dev_desc *dev, dev_t rdev)
147 {
148 dev->new = cpu_to_le32(new_encode_dev(rdev));
149 return sizeof(dev->new);
150 }
151
152 /**
153 * ubifs_add_dirt - add dirty space to LEB properties.
154 * @c: the UBIFS file-system description object
155 * @lnum: LEB to add dirty space for
156 * @dirty: dirty space to add
157 *
158 * This is a helper function which increased amount of dirty LEB space. Returns
159 * zero in case of success and a negative error code in case of failure.
160 */
161 static inline int ubifs_add_dirt(struct ubifs_info *c, int lnum, int dirty)
162 {
163 return ubifs_update_one_lp(c, lnum, LPROPS_NC, dirty, 0, 0);
164 }
165
166 /**
167 * ubifs_return_leb - return LEB to lprops.
168 * @c: the UBIFS file-system description object
169 * @lnum: LEB to return
170 *
171 * This helper function cleans the "taken" flag of a logical eraseblock in the
172 * lprops. Returns zero in case of success and a negative error code in case of
173 * failure.
174 */
175 static inline int ubifs_return_leb(struct ubifs_info *c, int lnum)
176 {
177 return ubifs_change_one_lp(c, lnum, LPROPS_NC, LPROPS_NC, 0,
178 LPROPS_TAKEN, 0);
179 }
180
181 /**
182 * ubifs_idx_node_sz - return index node size.
183 * @c: the UBIFS file-system description object
184 * @child_cnt: number of children of this index node
185 */
186 static inline int ubifs_idx_node_sz(const struct ubifs_info *c, int child_cnt)
187 {
188 return UBIFS_IDX_NODE_SZ + (UBIFS_BRANCH_SZ + c->key_len + c->hash_len)
189 * child_cnt;
190 }
191
192 /**
193 * ubifs_idx_branch - return pointer to an index branch.
194 * @c: the UBIFS file-system description object
195 * @idx: index node
196 * @bnum: branch number
197 */
198 static inline
199 struct ubifs_branch *ubifs_idx_branch(const struct ubifs_info *c,
200 const struct ubifs_idx_node *idx,
201 int bnum)
202 {
203 return (struct ubifs_branch *)((void *)idx->branches +
204 (UBIFS_BRANCH_SZ + c->key_len + c->hash_len) * bnum);
205 }
206
207 /**
208 * ubifs_idx_key - return pointer to an index key.
209 * @c: the UBIFS file-system description object
210 * @idx: index node
211 */
212 static inline void *ubifs_idx_key(const struct ubifs_info *c,
213 const struct ubifs_idx_node *idx)
214 {
215 return (void *)((struct ubifs_branch *)idx->branches)->key;
216 }
217
218 /**
219 * ubifs_tnc_lookup - look up a file-system node.
220 * @c: UBIFS file-system description object
221 * @key: node key to lookup
222 * @node: the node is returned here
223 *
224 * This function look up and reads node with key @key. The caller has to make
225 * sure the @node buffer is large enough to fit the node. Returns zero in case
226 * of success, %-ENOENT if the node was not found, and a negative error code in
227 * case of failure.
228 */
229 static inline int ubifs_tnc_lookup(struct ubifs_info *c,
230 const union ubifs_key *key, void *node)
231 {
232 return ubifs_tnc_locate(c, key, node, NULL, NULL);
233 }
234
235 /**
236 * ubifs_get_lprops - get reference to LEB properties.
237 * @c: the UBIFS file-system description object
238 *
239 * This function locks lprops. Lprops have to be unlocked by
240 * 'ubifs_release_lprops()'.
241 */
242 static inline void ubifs_get_lprops(struct ubifs_info *c)
243 {
244 mutex_lock(&c->lp_mutex);
245 }
246
247 /**
248 * ubifs_release_lprops - release lprops lock.
249 * @c: the UBIFS file-system description object
250 *
251 * This function has to be called after each 'ubifs_get_lprops()' call to
252 * unlock lprops.
253 */
254 static inline void ubifs_release_lprops(struct ubifs_info *c)
255 {
256 ubifs_assert(c, mutex_is_locked(&c->lp_mutex));
257 ubifs_assert(c, c->lst.empty_lebs >= 0 &&
258 c->lst.empty_lebs <= c->main_lebs);
259 mutex_unlock(&c->lp_mutex);
260 }
261
262 /**
263 * ubifs_next_log_lnum - switch to the next log LEB.
264 * @c: UBIFS file-system description object
265 * @lnum: current log LEB
266 *
267 * This helper function returns the log LEB number which goes next after LEB
268 * 'lnum'.
269 */
270 static inline int ubifs_next_log_lnum(const struct ubifs_info *c, int lnum)
271 {
272 lnum += 1;
273 if (lnum > c->log_last)
274 lnum = UBIFS_LOG_LNUM;
275
276 return lnum;
277 }
278
279 static inline int ubifs_xattr_max_cnt(struct ubifs_info *c)
280 {
281 int max_xattrs = (c->leb_size / 2) / UBIFS_INO_NODE_SZ;
282
283 ubifs_assert(c, max_xattrs < c->max_orphans);
284 return max_xattrs;
285 }
286
287 const char *ubifs_assert_action_name(struct ubifs_info *c);
288
289 #endif /* __UBIFS_MISC_H__ */
290
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