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Artem Bityutskiy1e517642008-07-14 19:08:37 +03001/*
2 * This file is part of UBIFS.
3 *
4 * Copyright (C) 2006-2008 Nokia Corporation
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 as published by
8 * the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
13 * more details.
14 *
15 * You should have received a copy of the GNU General Public License along with
16 * this program; if not, write to the Free Software Foundation, Inc., 51
17 * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
18 *
19 * Authors: Artem Bityutskiy (Битюцкий Артём)
20 * Adrian Hunter
21 */
22
23/*
24 * This file contains miscellaneous helper functions.
25 */
26
27#ifndef __UBIFS_MISC_H__
28#define __UBIFS_MISC_H__
29
30/**
31 * ubifs_zn_dirty - check if znode is dirty.
32 * @znode: znode to check
33 *
34 * This helper function returns %1 if @znode is dirty and %0 otherwise.
35 */
36static inline int ubifs_zn_dirty(const struct ubifs_znode *znode)
37{
38 return !!test_bit(DIRTY_ZNODE, &znode->flags);
39}
40
41/**
42 * ubifs_wake_up_bgt - wake up background thread.
43 * @c: UBIFS file-system description object
44 */
45static inline void ubifs_wake_up_bgt(struct ubifs_info *c)
46{
47 if (c->bgt && !c->need_bgt) {
48 c->need_bgt = 1;
49 wake_up_process(c->bgt);
50 }
51}
52
53/**
54 * ubifs_tnc_find_child - find next child in znode.
55 * @znode: znode to search at
56 * @start: the zbranch index to start at
57 *
58 * This helper function looks for znode child starting at index @start. Returns
59 * the child or %NULL if no children were found.
60 */
61static inline struct ubifs_znode *
62ubifs_tnc_find_child(struct ubifs_znode *znode, int start)
63{
64 while (start < znode->child_cnt) {
65 if (znode->zbranch[start].znode)
66 return znode->zbranch[start].znode;
67 start += 1;
68 }
69
70 return NULL;
71}
72
73/**
74 * ubifs_inode - get UBIFS inode information by VFS 'struct inode' object.
75 * @inode: the VFS 'struct inode' pointer
76 */
77static inline struct ubifs_inode *ubifs_inode(const struct inode *inode)
78{
79 return container_of(inode, struct ubifs_inode, vfs_inode);
80}
81
82/**
Artem Bityutskiy1e517642008-07-14 19:08:37 +030083 * ubifs_compr_present - check if compressor was compiled in.
84 * @compr_type: compressor type to check
85 *
86 * This function returns %1 of compressor of type @compr_type is present, and
87 * %0 if not.
88 */
89static inline int ubifs_compr_present(int compr_type)
90{
91 ubifs_assert(compr_type >= 0 && compr_type < UBIFS_COMPR_TYPES_CNT);
92 return !!ubifs_compressors[compr_type]->capi_name;
93}
94
95/**
96 * ubifs_compr_name - get compressor name string by its type.
97 * @compr_type: compressor type
98 *
99 * This function returns compressor type string.
100 */
101static inline const char *ubifs_compr_name(int compr_type)
102{
103 ubifs_assert(compr_type >= 0 && compr_type < UBIFS_COMPR_TYPES_CNT);
104 return ubifs_compressors[compr_type]->name;
105}
106
107/**
108 * ubifs_wbuf_sync - synchronize write-buffer.
109 * @wbuf: write-buffer to synchronize
110 *
111 * This is the same as as 'ubifs_wbuf_sync_nolock()' but it does not assume
112 * that the write-buffer is already locked.
113 */
114static inline int ubifs_wbuf_sync(struct ubifs_wbuf *wbuf)
115{
116 int err;
117
118 mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead);
119 err = ubifs_wbuf_sync_nolock(wbuf);
120 mutex_unlock(&wbuf->io_mutex);
121 return err;
122}
123
124/**
125 * ubifs_leb_unmap - unmap an LEB.
126 * @c: UBIFS file-system description object
127 * @lnum: LEB number to unmap
128 *
129 * This function returns %0 on success and a negative error code on failure.
130 */
131static inline int ubifs_leb_unmap(const struct ubifs_info *c, int lnum)
132{
133 int err;
134
135 if (c->ro_media)
136 return -EROFS;
137 err = ubi_leb_unmap(c->ubi, lnum);
138 if (err) {
139 ubifs_err("unmap LEB %d failed, error %d", lnum, err);
140 return err;
141 }
142
143 return 0;
144}
145
146/**
147 * ubifs_leb_write - write to a LEB.
148 * @c: UBIFS file-system description object
149 * @lnum: LEB number to write
150 * @buf: buffer to write from
151 * @offs: offset within LEB to write to
152 * @len: length to write
153 * @dtype: data type
154 *
155 * This function returns %0 on success and a negative error code on failure.
156 */
157static inline int ubifs_leb_write(const struct ubifs_info *c, int lnum,
158 const void *buf, int offs, int len, int dtype)
159{
160 int err;
161
162 if (c->ro_media)
163 return -EROFS;
164 err = ubi_leb_write(c->ubi, lnum, buf, offs, len, dtype);
165 if (err) {
166 ubifs_err("writing %d bytes at %d:%d, error %d",
167 len, lnum, offs, err);
168 return err;
169 }
170
171 return 0;
172}
173
174/**
175 * ubifs_leb_change - atomic LEB change.
176 * @c: UBIFS file-system description object
177 * @lnum: LEB number to write
178 * @buf: buffer to write from
179 * @len: length to write
180 * @dtype: data type
181 *
182 * This function returns %0 on success and a negative error code on failure.
183 */
184static inline int ubifs_leb_change(const struct ubifs_info *c, int lnum,
185 const void *buf, int len, int dtype)
186{
187 int err;
188
189 if (c->ro_media)
190 return -EROFS;
191 err = ubi_leb_change(c->ubi, lnum, buf, len, dtype);
192 if (err) {
193 ubifs_err("changing %d bytes in LEB %d, error %d",
194 len, lnum, err);
195 return err;
196 }
197
198 return 0;
199}
200
201/**
202 * ubifs_encode_dev - encode device node IDs.
203 * @dev: UBIFS device node information
204 * @rdev: device IDs to encode
205 *
206 * This is a helper function which encodes major/minor numbers of a device node
207 * into UBIFS device node description. We use standard Linux "new" and "huge"
208 * encodings.
209 */
210static inline int ubifs_encode_dev(union ubifs_dev_desc *dev, dev_t rdev)
211{
212 if (new_valid_dev(rdev)) {
213 dev->new = cpu_to_le32(new_encode_dev(rdev));
214 return sizeof(dev->new);
215 } else {
216 dev->huge = cpu_to_le64(huge_encode_dev(rdev));
217 return sizeof(dev->huge);
218 }
219}
220
221/**
222 * ubifs_add_dirt - add dirty space to LEB properties.
223 * @c: the UBIFS file-system description object
224 * @lnum: LEB to add dirty space for
225 * @dirty: dirty space to add
226 *
227 * This is a helper function which increased amount of dirty LEB space. Returns
228 * zero in case of success and a negative error code in case of failure.
229 */
230static inline int ubifs_add_dirt(struct ubifs_info *c, int lnum, int dirty)
231{
232 return ubifs_update_one_lp(c, lnum, LPROPS_NC, dirty, 0, 0);
233}
234
235/**
236 * ubifs_return_leb - return LEB to lprops.
237 * @c: the UBIFS file-system description object
238 * @lnum: LEB to return
239 *
240 * This helper function cleans the "taken" flag of a logical eraseblock in the
241 * lprops. Returns zero in case of success and a negative error code in case of
242 * failure.
243 */
244static inline int ubifs_return_leb(struct ubifs_info *c, int lnum)
245{
246 return ubifs_change_one_lp(c, lnum, LPROPS_NC, LPROPS_NC, 0,
247 LPROPS_TAKEN, 0);
248}
249
250/**
251 * ubifs_idx_node_sz - return index node size.
252 * @c: the UBIFS file-system description object
253 * @child_cnt: number of children of this index node
254 */
255static inline int ubifs_idx_node_sz(const struct ubifs_info *c, int child_cnt)
256{
257 return UBIFS_IDX_NODE_SZ + (UBIFS_BRANCH_SZ + c->key_len) * child_cnt;
258}
259
260/**
261 * ubifs_idx_branch - return pointer to an index branch.
262 * @c: the UBIFS file-system description object
263 * @idx: index node
264 * @bnum: branch number
265 */
266static inline
267struct ubifs_branch *ubifs_idx_branch(const struct ubifs_info *c,
268 const struct ubifs_idx_node *idx,
269 int bnum)
270{
271 return (struct ubifs_branch *)((void *)idx->branches +
272 (UBIFS_BRANCH_SZ + c->key_len) * bnum);
273}
274
275/**
276 * ubifs_idx_key - return pointer to an index key.
277 * @c: the UBIFS file-system description object
278 * @idx: index node
279 */
280static inline void *ubifs_idx_key(const struct ubifs_info *c,
281 const struct ubifs_idx_node *idx)
282{
283 return (void *)((struct ubifs_branch *)idx->branches)->key;
284}
285
286/**
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300287 * ubifs_current_time - round current time to time granularity.
288 * @inode: inode
289 */
290static inline struct timespec ubifs_current_time(struct inode *inode)
291{
292 return (inode->i_sb->s_time_gran < NSEC_PER_SEC) ?
293 current_fs_time(inode->i_sb) : CURRENT_TIME_SEC;
294}
295
Adrian Hunter601c0bc2008-08-22 14:23:35 +0300296/**
297 * ubifs_tnc_lookup - look up a file-system node.
298 * @c: UBIFS file-system description object
299 * @key: node key to lookup
300 * @node: the node is returned here
301 *
302 * This function look up and reads node with key @key. The caller has to make
303 * sure the @node buffer is large enough to fit the node. Returns zero in case
304 * of success, %-ENOENT if the node was not found, and a negative error code in
305 * case of failure.
306 */
307static inline int ubifs_tnc_lookup(struct ubifs_info *c,
308 const union ubifs_key *key, void *node)
309{
310 return ubifs_tnc_locate(c, key, node, NULL, NULL);
311}
312
Artem Bityutskiy746103a2008-08-27 12:50:57 +0300313/**
314 * ubifs_get_lprops - get reference to LEB properties.
315 * @c: the UBIFS file-system description object
316 *
317 * This function locks lprops. Lprops have to be unlocked by
318 * 'ubifs_release_lprops()'.
319 */
320static inline void ubifs_get_lprops(struct ubifs_info *c)
321{
322 mutex_lock(&c->lp_mutex);
323}
324
325/**
326 * ubifs_release_lprops - release lprops lock.
327 * @c: the UBIFS file-system description object
328 *
329 * This function has to be called after each 'ubifs_get_lprops()' call to
330 * unlock lprops.
331 */
332static inline void ubifs_release_lprops(struct ubifs_info *c)
333{
334 ubifs_assert(mutex_is_locked(&c->lp_mutex));
335 ubifs_assert(c->lst.empty_lebs >= 0 &&
336 c->lst.empty_lebs <= c->main_lebs);
337 mutex_unlock(&c->lp_mutex);
338}
339
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300340#endif /* __UBIFS_MISC_H__ */