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 /* 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 */ 36 static 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 */ 45 static 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 */ 61 static inline struct ubifs_znode * 62 ubifs_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 */ 77 static inline struct ubifs_inode *ubifs_inode(const struct inode *inode) 78 { 79 return container_of(inode, struct ubifs_inode, vfs_inode); 80 } 81 82 /** 83 * 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 */ 89 static 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 */ 101 static 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 */ 114 static 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 */ 131 static inline int ubifs_leb_unmap(const struct ubifs_info *c, int lnum) 132 { 133 int err; 134 135 ubifs_assert(!c->ro_media && !c->ro_mount); 136 if (c->ro_error) 137 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 */ 158 static 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; 162 163 ubifs_assert(!c->ro_media && !c->ro_mount); 164 if (c->ro_error) 165 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 */ 186 static inline int ubifs_leb_change(const struct ubifs_info *c, int lnum, 187 const void *buf, int len, int dtype) 188 { 189 int err; 190 191 ubifs_assert(!c->ro_media && !c->ro_mount); 192 if (c->ro_error) 193 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 */ 213 static 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 */ 233 static 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 */ 247 static 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 */ 258 static 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 */ 269 static inline 270 struct 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 */ 283 static 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 /** 290 * ubifs_current_time - round current time to time granularity. 291 * @inode: inode 292 */ 293 static 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 } 298 299 /** 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 */ 310 static 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 } 315 316 /** 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 */ 323 static 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 */ 335 static 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 } 342 343 /** 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 */ 351 static 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 } 359 360 #endif /* __UBIFS_MISC_H__ */ 361