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flags); 39 } 40 41 /** 42 * ubifs_zn_obsolete - check if znode is obsolete. 43 * @znode: znode to check 44 * 45 * This helper function returns %1 if @znode is obsolete and %0 otherwise. 46 */ 47 static inline int ubifs_zn_obsolete(const struct ubifs_znode *znode) 48 { 49 return !!test_bit(OBSOLETE_ZNODE, &znode->flags); 50 } 51 52 /** 53 * ubifs_zn_cow - check if znode has to be copied on write. 54 * @znode: znode to check 55 * 56 * This helper function returns %1 if @znode is has COW flag set and %0 57 * otherwise. 58 */ 59 static inline int ubifs_zn_cow(const struct ubifs_znode *znode) 60 { 61 return !!test_bit(COW_ZNODE, &znode->flags); 62 } 63 64 /** 65 * ubifs_wake_up_bgt - wake up background thread. 66 * @c: UBIFS file-system description object 67 */ 68 static inline void ubifs_wake_up_bgt(struct ubifs_info *c) 69 { 70 if (c->bgt && !c->need_bgt) { 71 c->need_bgt = 1; 72 wake_up_process(c->bgt); 73 } 74 } 75 76 /** 77 * ubifs_tnc_find_child - find next child in znode. 78 * @znode: znode to search at 79 * @start: the zbranch index to start at 80 * 81 * This helper function looks for znode child starting at index @start. Returns 82 * the child or %NULL if no children were found. 83 */ 84 static inline struct ubifs_znode * 85 ubifs_tnc_find_child(struct ubifs_znode *znode, int start) 86 { 87 while (start < znode->child_cnt) { 88 if (znode->zbranch[start].znode) 89 return znode->zbranch[start].znode; 90 start += 1; 91 } 92 93 return NULL; 94 } 95 96 /** 97 * ubifs_inode - get UBIFS inode information by VFS 'struct inode' object. 98 * @inode: the VFS 'struct inode' pointer 99 */ 100 static inline struct ubifs_inode *ubifs_inode(const struct inode *inode) 101 { 102 return container_of(inode, struct ubifs_inode, vfs_inode); 103 } 104 105 /** 106 * ubifs_compr_present - check if compressor was compiled in. 107 * @compr_type: compressor type to check 108 * 109 * This function returns %1 of compressor of type @compr_type is present, and 110 * %0 if not. 111 */ 112 static inline int ubifs_compr_present(int compr_type) 113 { 114 ubifs_assert(compr_type >= 0 && compr_type < UBIFS_COMPR_TYPES_CNT); 115 return !!ubifs_compressors[compr_type]->capi_name; 116 } 117 118 /** 119 * ubifs_compr_name - get compressor name string by its type. 120 * @compr_type: compressor type 121 * 122 * This function returns compressor type string. 123 */ 124 static inline const char *ubifs_compr_name(int compr_type) 125 { 126 ubifs_assert(compr_type >= 0 && compr_type < UBIFS_COMPR_TYPES_CNT); 127 return ubifs_compressors[compr_type]->name; 128 } 129 130 /** 131 * ubifs_wbuf_sync - synchronize write-buffer. 132 * @wbuf: write-buffer to synchronize 133 * 134 * This is the same as as 'ubifs_wbuf_sync_nolock()' but it does not assume 135 * that the write-buffer is already locked. 136 */ 137 static inline int ubifs_wbuf_sync(struct ubifs_wbuf *wbuf) 138 { 139 int err; 140 141 mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead); 142 err = ubifs_wbuf_sync_nolock(wbuf); 143 mutex_unlock(&wbuf->io_mutex); 144 return err; 145 } 146 147 /** 148 * ubifs_encode_dev - encode device node IDs. 149 * @dev: UBIFS device node information 150 * @rdev: device IDs to encode 151 * 152 * This is a helper function which encodes major/minor numbers of a device node 153 * into UBIFS device node description. We use standard Linux "new" and "huge" 154 * encodings. 155 */ 156 static inline int ubifs_encode_dev(union ubifs_dev_desc *dev, dev_t rdev) 157 { 158 if (new_valid_dev(rdev)) { 159 dev->new = cpu_to_le32(new_encode_dev(rdev)); 160 return sizeof(dev->new); 161 } else { 162 dev->huge = cpu_to_le64(huge_encode_dev(rdev)); 163 return sizeof(dev->huge); 164 } 165 } 166 167 /** 168 * ubifs_add_dirt - add dirty space to LEB properties. 169 * @c: the UBIFS file-system description object 170 * @lnum: LEB to add dirty space for 171 * @dirty: dirty space to add 172 * 173 * This is a helper function which increased amount of dirty LEB space. Returns 174 * zero in case of success and a negative error code in case of failure. 175 */ 176 static inline int ubifs_add_dirt(struct ubifs_info *c, int lnum, int dirty) 177 { 178 return ubifs_update_one_lp(c, lnum, LPROPS_NC, dirty, 0, 0); 179 } 180 181 /** 182 * ubifs_return_leb - return LEB to lprops. 183 * @c: the UBIFS file-system description object 184 * @lnum: LEB to return 185 * 186 * This helper function cleans the "taken" flag of a logical eraseblock in the 187 * lprops. Returns zero in case of success and a negative error code in case of 188 * failure. 189 */ 190 static inline int ubifs_return_leb(struct ubifs_info *c, int lnum) 191 { 192 return ubifs_change_one_lp(c, lnum, LPROPS_NC, LPROPS_NC, 0, 193 LPROPS_TAKEN, 0); 194 } 195 196 /** 197 * ubifs_idx_node_sz - return index node size. 198 * @c: the UBIFS file-system description object 199 * @child_cnt: number of children of this index node 200 */ 201 static inline int ubifs_idx_node_sz(const struct ubifs_info *c, int child_cnt) 202 { 203 return UBIFS_IDX_NODE_SZ + (UBIFS_BRANCH_SZ + c->key_len) * child_cnt; 204 } 205 206 /** 207 * ubifs_idx_branch - return pointer to an index branch. 208 * @c: the UBIFS file-system description object 209 * @idx: index node 210 * @bnum: branch number 211 */ 212 static inline 213 struct ubifs_branch *ubifs_idx_branch(const struct ubifs_info *c, 214 const struct ubifs_idx_node *idx, 215 int bnum) 216 { 217 return (struct ubifs_branch *)((void *)idx->branches + 218 (UBIFS_BRANCH_SZ + c->key_len) * bnum); 219 } 220 221 /** 222 * ubifs_idx_key - return pointer to an index key. 223 * @c: the UBIFS file-system description object 224 * @idx: index node 225 */ 226 static inline void *ubifs_idx_key(const struct ubifs_info *c, 227 const struct ubifs_idx_node *idx) 228 { 229 return (void *)((struct ubifs_branch *)idx->branches)->key; 230 } 231 232 /** 233 * ubifs_current_time - round current time to time granularity. 234 * @inode: inode 235 */ 236 static inline struct timespec ubifs_current_time(struct inode *inode) 237 { 238 return (inode->i_sb->s_time_gran < NSEC_PER_SEC) ? 239 current_fs_time(inode->i_sb) : CURRENT_TIME_SEC; 240 } 241 242 /** 243 * ubifs_tnc_lookup - look up a file-system node. 244 * @c: UBIFS file-system description object 245 * @key: node key to lookup 246 * @node: the node is returned here 247 * 248 * This function look up and reads node with key @key. The caller has to make 249 * sure the @node buffer is large enough to fit the node. Returns zero in case 250 * of success, %-ENOENT if the node was not found, and a negative error code in 251 * case of failure. 252 */ 253 static inline int ubifs_tnc_lookup(struct ubifs_info *c, 254 const union ubifs_key *key, void *node) 255 { 256 return ubifs_tnc_locate(c, key, node, NULL, NULL); 257 } 258 259 /** 260 * ubifs_get_lprops - get reference to LEB properties. 261 * @c: the UBIFS file-system description object 262 * 263 * This function locks lprops. Lprops have to be unlocked by 264 * 'ubifs_release_lprops()'. 265 */ 266 static inline void ubifs_get_lprops(struct ubifs_info *c) 267 { 268 mutex_lock(&c->lp_mutex); 269 } 270 271 /** 272 * ubifs_release_lprops - release lprops lock. 273 * @c: the UBIFS file-system description object 274 * 275 * This function has to be called after each 'ubifs_get_lprops()' call to 276 * unlock lprops. 277 */ 278 static inline void ubifs_release_lprops(struct ubifs_info *c) 279 { 280 ubifs_assert(mutex_is_locked(&c->lp_mutex)); 281 ubifs_assert(c->lst.empty_lebs >= 0 && 282 c->lst.empty_lebs <= c->main_lebs); 283 mutex_unlock(&c->lp_mutex); 284 } 285 286 /** 287 * ubifs_next_log_lnum - switch to the next log LEB. 288 * @c: UBIFS file-system description object 289 * @lnum: current log LEB 290 * 291 * This helper function returns the log LEB number which goes next after LEB 292 * 'lnum'. 293 */ 294 static inline int ubifs_next_log_lnum(const struct ubifs_info *c, int lnum) 295 { 296 lnum += 1; 297 if (lnum > c->log_last) 298 lnum = UBIFS_LOG_LNUM; 299 300 return lnum; 301 } 302 303 #endif /* __UBIFS_MISC_H__ */ 304