2 * This file is part of UBIFS.
4 * Copyright (C) 2006-2008 Nokia Corporation
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.
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
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
19 * Authors: Artem Bityutskiy (Битюцкий Артём)
24 * This file contains miscellaneous helper functions.
27 #ifndef __UBIFS_MISC_H__
28 #define __UBIFS_MISC_H__
31 * ubifs_zn_dirty - check if znode is dirty.
32 * @znode: znode to check
34 * This helper function returns %1 if @znode is dirty and %0 otherwise.
36 static inline int ubifs_zn_dirty(const struct ubifs_znode *znode)
38 return !!test_bit(DIRTY_ZNODE, &znode->flags);
42 * ubifs_wake_up_bgt - wake up background thread.
43 * @c: UBIFS file-system description object
45 static inline void ubifs_wake_up_bgt(struct ubifs_info *c)
47 if (c->bgt && !c->need_bgt) {
49 wake_up_process(c->bgt);
54 * ubifs_tnc_find_child - find next child in znode.
55 * @znode: znode to search at
56 * @start: the zbranch index to start at
58 * This helper function looks for znode child starting at index @start. Returns
59 * the child or %NULL if no children were found.
61 static inline struct ubifs_znode *
62 ubifs_tnc_find_child(struct ubifs_znode *znode, int start)
64 while (start < znode->child_cnt) {
65 if (znode->zbranch[start].znode)
66 return znode->zbranch[start].znode;
74 * ubifs_inode - get UBIFS inode information by VFS 'struct inode' object.
75 * @inode: the VFS 'struct inode' pointer
77 static inline struct ubifs_inode *ubifs_inode(const struct inode *inode)
79 return container_of(inode, struct ubifs_inode, vfs_inode);
83 * ubifs_compr_present - check if compressor was compiled in.
84 * @compr_type: compressor type to check
86 * This function returns %1 of compressor of type @compr_type is present, and
89 static inline int ubifs_compr_present(int compr_type)
91 ubifs_assert(compr_type >= 0 && compr_type < UBIFS_COMPR_TYPES_CNT);
92 return !!ubifs_compressors[compr_type]->capi_name;
96 * ubifs_compr_name - get compressor name string by its type.
97 * @compr_type: compressor type
99 * This function returns compressor type string.
101 static inline const char *ubifs_compr_name(int compr_type)
103 ubifs_assert(compr_type >= 0 && compr_type < UBIFS_COMPR_TYPES_CNT);
104 return ubifs_compressors[compr_type]->name;
108 * ubifs_wbuf_sync - synchronize write-buffer.
109 * @wbuf: write-buffer to synchronize
111 * This is the same as as 'ubifs_wbuf_sync_nolock()' but it does not assume
112 * that the write-buffer is already locked.
114 static inline int ubifs_wbuf_sync(struct ubifs_wbuf *wbuf)
118 mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead);
119 err = ubifs_wbuf_sync_nolock(wbuf);
120 mutex_unlock(&wbuf->io_mutex);
125 * ubifs_leb_unmap - unmap an LEB.
126 * @c: UBIFS file-system description object
127 * @lnum: LEB number to unmap
129 * This function returns %0 on success and a negative error code on failure.
131 static inline int ubifs_leb_unmap(const struct ubifs_info *c, int lnum)
137 err = ubi_leb_unmap(c->ubi, lnum);
139 ubifs_err("unmap LEB %d failed, error %d", lnum, err);
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
155 * This function returns %0 on success and a negative error code on failure.
157 static inline int ubifs_leb_write(const struct ubifs_info *c, int lnum,
158 const void *buf, int offs, int len, int dtype)
164 err = ubi_leb_write(c->ubi, lnum, buf, offs, len, dtype);
166 ubifs_err("writing %d bytes at %d:%d, error %d",
167 len, lnum, offs, err);
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
182 * This function returns %0 on success and a negative error code on failure.
184 static inline int ubifs_leb_change(const struct ubifs_info *c, int lnum,
185 const void *buf, int len, int dtype)
191 err = ubi_leb_change(c->ubi, lnum, buf, len, dtype);
193 ubifs_err("changing %d bytes in LEB %d, error %d",
202 * ubifs_encode_dev - encode device node IDs.
203 * @dev: UBIFS device node information
204 * @rdev: device IDs to encode
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"
210 static inline int ubifs_encode_dev(union ubifs_dev_desc *dev, dev_t rdev)
212 if (new_valid_dev(rdev)) {
213 dev->new = cpu_to_le32(new_encode_dev(rdev));
214 return sizeof(dev->new);
216 dev->huge = cpu_to_le64(huge_encode_dev(rdev));
217 return sizeof(dev->huge);
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
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.
230 static inline int ubifs_add_dirt(struct ubifs_info *c, int lnum, int dirty)
232 return ubifs_update_one_lp(c, lnum, LPROPS_NC, dirty, 0, 0);
236 * ubifs_return_leb - return LEB to lprops.
237 * @c: the UBIFS file-system description object
238 * @lnum: LEB to return
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
244 static inline int ubifs_return_leb(struct ubifs_info *c, int lnum)
246 return ubifs_change_one_lp(c, lnum, LPROPS_NC, LPROPS_NC, 0,
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
255 static inline int ubifs_idx_node_sz(const struct ubifs_info *c, int child_cnt)
257 return UBIFS_IDX_NODE_SZ + (UBIFS_BRANCH_SZ + c->key_len) * child_cnt;
261 * ubifs_idx_branch - return pointer to an index branch.
262 * @c: the UBIFS file-system description object
264 * @bnum: branch number
267 struct ubifs_branch *ubifs_idx_branch(const struct ubifs_info *c,
268 const struct ubifs_idx_node *idx,
271 return (struct ubifs_branch *)((void *)idx->branches +
272 (UBIFS_BRANCH_SZ + c->key_len) * bnum);
276 * ubifs_idx_key - return pointer to an index key.
277 * @c: the UBIFS file-system description object
280 static inline void *ubifs_idx_key(const struct ubifs_info *c,
281 const struct ubifs_idx_node *idx)
283 return (void *)((struct ubifs_branch *)idx->branches)->key;
287 * ubifs_reported_space - calculate reported free space.
288 * @c: the UBIFS file-system description object
289 * @free: amount of free space
291 * This function calculates amount of free space which will be reported to
292 * user-space. User-space application tend to expect that if the file-system
293 * (e.g., via the 'statfs()' call) reports that it has N bytes available, they
294 * are able to write a file of size N. UBIFS attaches node headers to each data
295 * node and it has to write indexind nodes as well. This introduces additional
296 * overhead, and UBIFS it has to report sligtly less free space to meet the
299 * This function assumes free space is made up of uncompressed data nodes and
300 * full index nodes (one per data node, doubled because we always allow enough
301 * space to write the index twice).
303 * Note, the calculation is pessimistic, which means that most of the time
304 * UBIFS reports less space than it actually has.
306 static inline long long ubifs_reported_space(const struct ubifs_info *c,
311 divisor = UBIFS_MAX_DATA_NODE_SZ + (c->max_idx_node_sz * 3);
312 factor = UBIFS_MAX_DATA_NODE_SZ - UBIFS_DATA_NODE_SZ;
313 do_div(free, divisor);
315 return free * factor;
319 * ubifs_current_time - round current time to time granularity.
322 static inline struct timespec ubifs_current_time(struct inode *inode)
324 return (inode->i_sb->s_time_gran < NSEC_PER_SEC) ?
325 current_fs_time(inode->i_sb) : CURRENT_TIME_SEC;
328 #endif /* __UBIFS_MISC_H__ */