misc.h 8.2 KB

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  1. /*
  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. * This file contains miscellaneous helper functions.
  24. */
  25. #ifndef __UBIFS_MISC_H__
  26. #define __UBIFS_MISC_H__
  27. /**
  28. * ubifs_zn_dirty - check if znode is dirty.
  29. * @znode: znode to check
  30. *
  31. * This helper function returns %1 if @znode is dirty and %0 otherwise.
  32. */
  33. static inline int ubifs_zn_dirty(const struct ubifs_znode *znode)
  34. {
  35. return !!test_bit(DIRTY_ZNODE, &znode->flags);
  36. }
  37. /**
  38. * ubifs_wake_up_bgt - wake up background thread.
  39. * @c: UBIFS file-system description object
  40. */
  41. static inline void ubifs_wake_up_bgt(struct ubifs_info *c)
  42. {
  43. if (c->bgt && !c->need_bgt) {
  44. c->need_bgt = 1;
  45. wake_up_process(c->bgt);
  46. }
  47. }
  48. /**
  49. * ubifs_tnc_find_child - find next child in znode.
  50. * @znode: znode to search at
  51. * @start: the zbranch index to start at
  52. *
  53. * This helper function looks for znode child starting at index @start. Returns
  54. * the child or %NULL if no children were found.
  55. */
  56. static inline struct ubifs_znode *
  57. ubifs_tnc_find_child(struct ubifs_znode *znode, int start)
  58. {
  59. while (start < znode->child_cnt) {
  60. if (znode->zbranch[start].znode)
  61. return znode->zbranch[start].znode;
  62. start += 1;
  63. }
  64. return NULL;
  65. }
  66. /**
  67. * ubifs_inode - get UBIFS inode information by VFS 'struct inode' object.
  68. * @inode: the VFS 'struct inode' pointer
  69. */
  70. static inline struct ubifs_inode *ubifs_inode(const struct inode *inode)
  71. {
  72. return container_of(inode, struct ubifs_inode, vfs_inode);
  73. }
  74. /**
  75. * ubifs_compr_present - check if compressor was compiled in.
  76. * @compr_type: compressor type to check
  77. *
  78. * This function returns %1 of compressor of type @compr_type is present, and
  79. * %0 if not.
  80. */
  81. static inline int ubifs_compr_present(int compr_type)
  82. {
  83. ubifs_assert(compr_type >= 0 && compr_type < UBIFS_COMPR_TYPES_CNT);
  84. return !!ubifs_compressors[compr_type]->capi_name;
  85. }
  86. /**
  87. * ubifs_compr_name - get compressor name string by its type.
  88. * @compr_type: compressor type
  89. *
  90. * This function returns compressor type string.
  91. */
  92. static inline const char *ubifs_compr_name(int compr_type)
  93. {
  94. ubifs_assert(compr_type >= 0 && compr_type < UBIFS_COMPR_TYPES_CNT);
  95. return ubifs_compressors[compr_type]->name;
  96. }
  97. /**
  98. * ubifs_wbuf_sync - synchronize write-buffer.
  99. * @wbuf: write-buffer to synchronize
  100. *
  101. * This is the same as as 'ubifs_wbuf_sync_nolock()' but it does not assume
  102. * that the write-buffer is already locked.
  103. */
  104. static inline int ubifs_wbuf_sync(struct ubifs_wbuf *wbuf)
  105. {
  106. int err;
  107. mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead);
  108. err = ubifs_wbuf_sync_nolock(wbuf);
  109. mutex_unlock(&wbuf->io_mutex);
  110. return err;
  111. }
  112. /**
  113. * ubifs_leb_unmap - unmap an LEB.
  114. * @c: UBIFS file-system description object
  115. * @lnum: LEB number to unmap
  116. *
  117. * This function returns %0 on success and a negative error code on failure.
  118. */
  119. static inline int ubifs_leb_unmap(const struct ubifs_info *c, int lnum)
  120. {
  121. int err;
  122. if (c->ro_media)
  123. return -EROFS;
  124. err = ubi_leb_unmap(c->ubi, lnum);
  125. if (err) {
  126. ubifs_err("unmap LEB %d failed, error %d", lnum, err);
  127. return err;
  128. }
  129. return 0;
  130. }
  131. /**
  132. * ubifs_leb_write - write to a LEB.
  133. * @c: UBIFS file-system description object
  134. * @lnum: LEB number to write
  135. * @buf: buffer to write from
  136. * @offs: offset within LEB to write to
  137. * @len: length to write
  138. * @dtype: data type
  139. *
  140. * This function returns %0 on success and a negative error code on failure.
  141. */
  142. static inline int ubifs_leb_write(const struct ubifs_info *c, int lnum,
  143. const void *buf, int offs, int len, int dtype)
  144. {
  145. int err;
  146. if (c->ro_media)
  147. return -EROFS;
  148. err = ubi_leb_write(c->ubi, lnum, buf, offs, len, dtype);
  149. if (err) {
  150. ubifs_err("writing %d bytes at %d:%d, error %d",
  151. len, lnum, offs, err);
  152. return err;
  153. }
  154. return 0;
  155. }
  156. /**
  157. * ubifs_leb_change - atomic LEB change.
  158. * @c: UBIFS file-system description object
  159. * @lnum: LEB number to write
  160. * @buf: buffer to write from
  161. * @len: length to write
  162. * @dtype: data type
  163. *
  164. * This function returns %0 on success and a negative error code on failure.
  165. */
  166. static inline int ubifs_leb_change(const struct ubifs_info *c, int lnum,
  167. const void *buf, int len, int dtype)
  168. {
  169. int err;
  170. if (c->ro_media)
  171. return -EROFS;
  172. err = ubi_leb_change(c->ubi, lnum, buf, len, dtype);
  173. if (err) {
  174. ubifs_err("changing %d bytes in LEB %d, error %d",
  175. len, lnum, err);
  176. return err;
  177. }
  178. return 0;
  179. }
  180. /**
  181. * ubifs_add_dirt - add dirty space to LEB properties.
  182. * @c: the UBIFS file-system description object
  183. * @lnum: LEB to add dirty space for
  184. * @dirty: dirty space to add
  185. *
  186. * This is a helper function which increased amount of dirty LEB space. Returns
  187. * zero in case of success and a negative error code in case of failure.
  188. */
  189. static inline int ubifs_add_dirt(struct ubifs_info *c, int lnum, int dirty)
  190. {
  191. return ubifs_update_one_lp(c, lnum, LPROPS_NC, dirty, 0, 0);
  192. }
  193. /**
  194. * ubifs_return_leb - return LEB to lprops.
  195. * @c: the UBIFS file-system description object
  196. * @lnum: LEB to return
  197. *
  198. * This helper function cleans the "taken" flag of a logical eraseblock in the
  199. * lprops. Returns zero in case of success and a negative error code in case of
  200. * failure.
  201. */
  202. static inline int ubifs_return_leb(struct ubifs_info *c, int lnum)
  203. {
  204. return ubifs_change_one_lp(c, lnum, LPROPS_NC, LPROPS_NC, 0,
  205. LPROPS_TAKEN, 0);
  206. }
  207. /**
  208. * ubifs_idx_node_sz - return index node size.
  209. * @c: the UBIFS file-system description object
  210. * @child_cnt: number of children of this index node
  211. */
  212. static inline int ubifs_idx_node_sz(const struct ubifs_info *c, int child_cnt)
  213. {
  214. return UBIFS_IDX_NODE_SZ + (UBIFS_BRANCH_SZ + c->key_len) * child_cnt;
  215. }
  216. /**
  217. * ubifs_idx_branch - return pointer to an index branch.
  218. * @c: the UBIFS file-system description object
  219. * @idx: index node
  220. * @bnum: branch number
  221. */
  222. static inline
  223. struct ubifs_branch *ubifs_idx_branch(const struct ubifs_info *c,
  224. const struct ubifs_idx_node *idx,
  225. int bnum)
  226. {
  227. return (struct ubifs_branch *)((void *)idx->branches +
  228. (UBIFS_BRANCH_SZ + c->key_len) * bnum);
  229. }
  230. /**
  231. * ubifs_idx_key - return pointer to an index key.
  232. * @c: the UBIFS file-system description object
  233. * @idx: index node
  234. */
  235. static inline void *ubifs_idx_key(const struct ubifs_info *c,
  236. const struct ubifs_idx_node *idx)
  237. {
  238. return (void *)((struct ubifs_branch *)idx->branches)->key;
  239. }
  240. /**
  241. * ubifs_tnc_lookup - look up a file-system node.
  242. * @c: UBIFS file-system description object
  243. * @key: node key to lookup
  244. * @node: the node is returned here
  245. *
  246. * This function look up and reads node with key @key. The caller has to make
  247. * sure the @node buffer is large enough to fit the node. Returns zero in case
  248. * of success, %-ENOENT if the node was not found, and a negative error code in
  249. * case of failure.
  250. */
  251. static inline int ubifs_tnc_lookup(struct ubifs_info *c,
  252. const union ubifs_key *key, void *node)
  253. {
  254. return ubifs_tnc_locate(c, key, node, NULL, NULL);
  255. }
  256. /**
  257. * ubifs_get_lprops - get reference to LEB properties.
  258. * @c: the UBIFS file-system description object
  259. *
  260. * This function locks lprops. Lprops have to be unlocked by
  261. * 'ubifs_release_lprops()'.
  262. */
  263. static inline void ubifs_get_lprops(struct ubifs_info *c)
  264. {
  265. mutex_lock(&c->lp_mutex);
  266. }
  267. /**
  268. * ubifs_release_lprops - release lprops lock.
  269. * @c: the UBIFS file-system description object
  270. *
  271. * This function has to be called after each 'ubifs_get_lprops()' call to
  272. * unlock lprops.
  273. */
  274. static inline void ubifs_release_lprops(struct ubifs_info *c)
  275. {
  276. ubifs_assert(mutex_is_locked(&c->lp_mutex));
  277. ubifs_assert(c->lst.empty_lebs >= 0 &&
  278. c->lst.empty_lebs <= c->main_lebs);
  279. mutex_unlock(&c->lp_mutex);
  280. }
  281. #endif /* __UBIFS_MISC_H__ */