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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
Artem Bityutskiy2ef13292010-09-19 18:34:26 +0300135 ubifs_assert(!c->ro_media && !c->ro_mount);
Artem Bityutskiy2680d722010-09-17 16:44:28 +0300136 if (c->ro_error)
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300137 return -EROFS;
138 err = ubi_leb_unmap(c->ubi, lnum);
139 if (err) {
140 ubifs_err("unmap LEB %d failed, error %d", lnum, err);
141 return err;
142 }
143
144 return 0;
145}
146
147/**
148 * ubifs_leb_write - write to a LEB.
149 * @c: UBIFS file-system description object
150 * @lnum: LEB number to write
151 * @buf: buffer to write from
152 * @offs: offset within LEB to write to
153 * @len: length to write
154 * @dtype: data type
155 *
156 * This function returns %0 on success and a negative error code on failure.
157 */
158static inline int ubifs_leb_write(const struct ubifs_info *c, int lnum,
159 const void *buf, int offs, int len, int dtype)
160{
161 int err;
162
Artem Bityutskiy2ef13292010-09-19 18:34:26 +0300163 ubifs_assert(!c->ro_media && !c->ro_mount);
Artem Bityutskiy2680d722010-09-17 16:44:28 +0300164 if (c->ro_error)
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300165 return -EROFS;
166 err = ubi_leb_write(c->ubi, lnum, buf, offs, len, dtype);
167 if (err) {
168 ubifs_err("writing %d bytes at %d:%d, error %d",
169 len, lnum, offs, err);
170 return err;
171 }
172
173 return 0;
174}
175
176/**
177 * ubifs_leb_change - atomic LEB change.
178 * @c: UBIFS file-system description object
179 * @lnum: LEB number to write
180 * @buf: buffer to write from
181 * @len: length to write
182 * @dtype: data type
183 *
184 * This function returns %0 on success and a negative error code on failure.
185 */
186static inline int ubifs_leb_change(const struct ubifs_info *c, int lnum,
187 const void *buf, int len, int dtype)
188{
189 int err;
190
Artem Bityutskiy2ef13292010-09-19 18:34:26 +0300191 ubifs_assert(!c->ro_media && !c->ro_mount);
Artem Bityutskiy2680d722010-09-17 16:44:28 +0300192 if (c->ro_error)
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300193 return -EROFS;
194 err = ubi_leb_change(c->ubi, lnum, buf, len, dtype);
195 if (err) {
196 ubifs_err("changing %d bytes in LEB %d, error %d",
197 len, lnum, err);
198 return err;
199 }
200
201 return 0;
202}
203
204/**
205 * ubifs_encode_dev - encode device node IDs.
206 * @dev: UBIFS device node information
207 * @rdev: device IDs to encode
208 *
209 * This is a helper function which encodes major/minor numbers of a device node
210 * into UBIFS device node description. We use standard Linux "new" and "huge"
211 * encodings.
212 */
213static inline int ubifs_encode_dev(union ubifs_dev_desc *dev, dev_t rdev)
214{
215 if (new_valid_dev(rdev)) {
216 dev->new = cpu_to_le32(new_encode_dev(rdev));
217 return sizeof(dev->new);
218 } else {
219 dev->huge = cpu_to_le64(huge_encode_dev(rdev));
220 return sizeof(dev->huge);
221 }
222}
223
224/**
225 * ubifs_add_dirt - add dirty space to LEB properties.
226 * @c: the UBIFS file-system description object
227 * @lnum: LEB to add dirty space for
228 * @dirty: dirty space to add
229 *
230 * This is a helper function which increased amount of dirty LEB space. Returns
231 * zero in case of success and a negative error code in case of failure.
232 */
233static inline int ubifs_add_dirt(struct ubifs_info *c, int lnum, int dirty)
234{
235 return ubifs_update_one_lp(c, lnum, LPROPS_NC, dirty, 0, 0);
236}
237
238/**
239 * ubifs_return_leb - return LEB to lprops.
240 * @c: the UBIFS file-system description object
241 * @lnum: LEB to return
242 *
243 * This helper function cleans the "taken" flag of a logical eraseblock in the
244 * lprops. Returns zero in case of success and a negative error code in case of
245 * failure.
246 */
247static inline int ubifs_return_leb(struct ubifs_info *c, int lnum)
248{
249 return ubifs_change_one_lp(c, lnum, LPROPS_NC, LPROPS_NC, 0,
250 LPROPS_TAKEN, 0);
251}
252
253/**
254 * ubifs_idx_node_sz - return index node size.
255 * @c: the UBIFS file-system description object
256 * @child_cnt: number of children of this index node
257 */
258static inline int ubifs_idx_node_sz(const struct ubifs_info *c, int child_cnt)
259{
260 return UBIFS_IDX_NODE_SZ + (UBIFS_BRANCH_SZ + c->key_len) * child_cnt;
261}
262
263/**
264 * ubifs_idx_branch - return pointer to an index branch.
265 * @c: the UBIFS file-system description object
266 * @idx: index node
267 * @bnum: branch number
268 */
269static inline
270struct ubifs_branch *ubifs_idx_branch(const struct ubifs_info *c,
271 const struct ubifs_idx_node *idx,
272 int bnum)
273{
274 return (struct ubifs_branch *)((void *)idx->branches +
275 (UBIFS_BRANCH_SZ + c->key_len) * bnum);
276}
277
278/**
279 * ubifs_idx_key - return pointer to an index key.
280 * @c: the UBIFS file-system description object
281 * @idx: index node
282 */
283static inline void *ubifs_idx_key(const struct ubifs_info *c,
284 const struct ubifs_idx_node *idx)
285{
286 return (void *)((struct ubifs_branch *)idx->branches)->key;
287}
288
289/**
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300290 * ubifs_current_time - round current time to time granularity.
291 * @inode: inode
292 */
293static inline struct timespec ubifs_current_time(struct inode *inode)
294{
295 return (inode->i_sb->s_time_gran < NSEC_PER_SEC) ?
296 current_fs_time(inode->i_sb) : CURRENT_TIME_SEC;
297}
298
Adrian Hunter601c0bc2008-08-22 14:23:35 +0300299/**
300 * ubifs_tnc_lookup - look up a file-system node.
301 * @c: UBIFS file-system description object
302 * @key: node key to lookup
303 * @node: the node is returned here
304 *
305 * This function look up and reads node with key @key. The caller has to make
306 * sure the @node buffer is large enough to fit the node. Returns zero in case
307 * of success, %-ENOENT if the node was not found, and a negative error code in
308 * case of failure.
309 */
310static inline int ubifs_tnc_lookup(struct ubifs_info *c,
311 const union ubifs_key *key, void *node)
312{
313 return ubifs_tnc_locate(c, key, node, NULL, NULL);
314}
315
Artem Bityutskiy746103a2008-08-27 12:50:57 +0300316/**
317 * ubifs_get_lprops - get reference to LEB properties.
318 * @c: the UBIFS file-system description object
319 *
320 * This function locks lprops. Lprops have to be unlocked by
321 * 'ubifs_release_lprops()'.
322 */
323static inline void ubifs_get_lprops(struct ubifs_info *c)
324{
325 mutex_lock(&c->lp_mutex);
326}
327
328/**
329 * ubifs_release_lprops - release lprops lock.
330 * @c: the UBIFS file-system description object
331 *
332 * This function has to be called after each 'ubifs_get_lprops()' call to
333 * unlock lprops.
334 */
335static inline void ubifs_release_lprops(struct ubifs_info *c)
336{
337 ubifs_assert(mutex_is_locked(&c->lp_mutex));
338 ubifs_assert(c->lst.empty_lebs >= 0 &&
339 c->lst.empty_lebs <= c->main_lebs);
340 mutex_unlock(&c->lp_mutex);
341}
342
Artem Bityutskiye11602e2011-05-06 17:52:32 +0300343/**
344 * ubifs_next_log_lnum - switch to the next log LEB.
345 * @c: UBIFS file-system description object
346 * @lnum: current log LEB
347 *
348 * This helper function returns the log LEB number which goes next after LEB
349 * 'lnum'.
350 */
351static inline int ubifs_next_log_lnum(const struct ubifs_info *c, int lnum)
352{
353 lnum += 1;
354 if (lnum > c->log_last)
355 lnum = UBIFS_LOG_LNUM;
356
357 return lnum;
358}
359
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300360#endif /* __UBIFS_MISC_H__ */