1 /* 2 * This file is part of UBIFS. 3 * 4 * Copyright (C) 2006-2008 Nokia Corporation 5 * 6 * SPDX-License-Identifier: GPL-2.0+ 7 * 8 * Authors: Artem Bityutskiy (Битюцкий Артём) 9 * Adrian Hunter 10 */ 11 12 /* 13 * This file contains miscellaneous helper functions. 14 */ 15 16 #ifndef __UBIFS_MISC_H__ 17 #define __UBIFS_MISC_H__ 18 19 /** 20 * ubifs_zn_dirty - check if znode is dirty. 21 * @znode: znode to check 22 * 23 * This helper function returns %1 if @znode is dirty and %0 otherwise. 24 */ 25 static inline int ubifs_zn_dirty(const struct ubifs_znode *znode) 26 { 27 return !!test_bit(DIRTY_ZNODE, &znode->flags); 28 } 29 30 /** 31 * ubifs_zn_obsolete - check if znode is obsolete. 32 * @znode: znode to check 33 * 34 * This helper function returns %1 if @znode is obsolete and %0 otherwise. 35 */ 36 static inline int ubifs_zn_obsolete(const struct ubifs_znode *znode) 37 { 38 return !!test_bit(OBSOLETE_ZNODE, &znode->flags); 39 } 40 41 /** 42 * ubifs_zn_cow - check if znode has to be copied on write. 43 * @znode: znode to check 44 * 45 * This helper function returns %1 if @znode is has COW flag set and %0 46 * otherwise. 47 */ 48 static inline int ubifs_zn_cow(const struct ubifs_znode *znode) 49 { 50 return !!test_bit(COW_ZNODE, &znode->flags); 51 } 52 53 /** 54 * ubifs_wake_up_bgt - wake up background thread. 55 * @c: UBIFS file-system description object 56 */ 57 static inline void ubifs_wake_up_bgt(struct ubifs_info *c) 58 { 59 if (c->bgt && !c->need_bgt) { 60 c->need_bgt = 1; 61 wake_up_process(c->bgt); 62 } 63 } 64 65 /** 66 * ubifs_tnc_find_child - find next child in znode. 67 * @znode: znode to search at 68 * @start: the zbranch index to start at 69 * 70 * This helper function looks for znode child starting at index @start. Returns 71 * the child or %NULL if no children were found. 72 */ 73 static inline struct ubifs_znode * 74 ubifs_tnc_find_child(struct ubifs_znode *znode, int start) 75 { 76 while (start < znode->child_cnt) { 77 if (znode->zbranch[start].znode) 78 return znode->zbranch[start].znode; 79 start += 1; 80 } 81 82 return NULL; 83 } 84 85 /** 86 * ubifs_inode - get UBIFS inode information by VFS 'struct inode' object. 87 * @inode: the VFS 'struct inode' pointer 88 */ 89 static inline struct ubifs_inode *ubifs_inode(const struct inode *inode) 90 { 91 return container_of(inode, struct ubifs_inode, vfs_inode); 92 } 93 94 /** 95 * ubifs_compr_present - check if compressor was compiled in. 96 * @compr_type: compressor type to check 97 * 98 * This function returns %1 of compressor of type @compr_type is present, and 99 * %0 if not. 100 */ 101 static inline int ubifs_compr_present(int compr_type) 102 { 103 ubifs_assert(compr_type >= 0 && compr_type < UBIFS_COMPR_TYPES_CNT); 104 return !!ubifs_compressors[compr_type]->capi_name; 105 } 106 107 /** 108 * ubifs_compr_name - get compressor name string by its type. 109 * @compr_type: compressor type 110 * 111 * This function returns compressor type string. 112 */ 113 static inline const char *ubifs_compr_name(int compr_type) 114 { 115 ubifs_assert(compr_type >= 0 && compr_type < UBIFS_COMPR_TYPES_CNT); 116 return ubifs_compressors[compr_type]->name; 117 } 118 119 /** 120 * ubifs_wbuf_sync - synchronize write-buffer. 121 * @wbuf: write-buffer to synchronize 122 * 123 * This is the same as as 'ubifs_wbuf_sync_nolock()' but it does not assume 124 * that the write-buffer is already locked. 125 */ 126 static inline int ubifs_wbuf_sync(struct ubifs_wbuf *wbuf) 127 { 128 int err; 129 130 mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead); 131 err = ubifs_wbuf_sync_nolock(wbuf); 132 mutex_unlock(&wbuf->io_mutex); 133 return err; 134 } 135 136 #ifndef __UBOOT__ 137 /** 138 * ubifs_encode_dev - encode device node IDs. 139 * @dev: UBIFS device node information 140 * @rdev: device IDs to encode 141 * 142 * This is a helper function which encodes major/minor numbers of a device node 143 * into UBIFS device node description. We use standard Linux "new" and "huge" 144 * encodings. 145 */ 146 static inline int ubifs_encode_dev(union ubifs_dev_desc *dev, dev_t rdev) 147 { 148 if (new_valid_dev(rdev)) { 149 dev->new = cpu_to_le32(new_encode_dev(rdev)); 150 return sizeof(dev->new); 151 } else { 152 dev->huge = cpu_to_le64(huge_encode_dev(rdev)); 153 return sizeof(dev->huge); 154 } 155 } 156 #endif 157 158 /** 159 * ubifs_add_dirt - add dirty space to LEB properties. 160 * @c: the UBIFS file-system description object 161 * @lnum: LEB to add dirty space for 162 * @dirty: dirty space to add 163 * 164 * This is a helper function which increased amount of dirty LEB space. Returns 165 * zero in case of success and a negative error code in case of failure. 166 */ 167 static inline int ubifs_add_dirt(struct ubifs_info *c, int lnum, int dirty) 168 { 169 return ubifs_update_one_lp(c, lnum, LPROPS_NC, dirty, 0, 0); 170 } 171 172 /** 173 * ubifs_return_leb - return LEB to lprops. 174 * @c: the UBIFS file-system description object 175 * @lnum: LEB to return 176 * 177 * This helper function cleans the "taken" flag of a logical eraseblock in the 178 * lprops. Returns zero in case of success and a negative error code in case of 179 * failure. 180 */ 181 static inline int ubifs_return_leb(struct ubifs_info *c, int lnum) 182 { 183 return ubifs_change_one_lp(c, lnum, LPROPS_NC, LPROPS_NC, 0, 184 LPROPS_TAKEN, 0); 185 } 186 187 /** 188 * ubifs_idx_node_sz - return index node size. 189 * @c: the UBIFS file-system description object 190 * @child_cnt: number of children of this index node 191 */ 192 static inline int ubifs_idx_node_sz(const struct ubifs_info *c, int child_cnt) 193 { 194 return UBIFS_IDX_NODE_SZ + (UBIFS_BRANCH_SZ + c->key_len) * child_cnt; 195 } 196 197 /** 198 * ubifs_idx_branch - return pointer to an index branch. 199 * @c: the UBIFS file-system description object 200 * @idx: index node 201 * @bnum: branch number 202 */ 203 static inline 204 struct ubifs_branch *ubifs_idx_branch(const struct ubifs_info *c, 205 const struct ubifs_idx_node *idx, 206 int bnum) 207 { 208 return (struct ubifs_branch *)((void *)idx->branches + 209 (UBIFS_BRANCH_SZ + c->key_len) * bnum); 210 } 211 212 /** 213 * ubifs_idx_key - return pointer to an index key. 214 * @c: the UBIFS file-system description object 215 * @idx: index node 216 */ 217 static inline void *ubifs_idx_key(const struct ubifs_info *c, 218 const struct ubifs_idx_node *idx) 219 { 220 #ifndef __UBOOT__ 221 return (void *)((struct ubifs_branch *)idx->branches)->key; 222 #else 223 struct ubifs_branch *tmp; 224 225 tmp = (struct ubifs_branch *)idx->branches; 226 return (void *)tmp->key; 227 #endif 228 } 229 230 /** 231 * ubifs_current_time - round current time to time granularity. 232 * @inode: inode 233 */ 234 static inline struct timespec ubifs_current_time(struct inode *inode) 235 { 236 return (inode->i_sb->s_time_gran < NSEC_PER_SEC) ? 237 current_fs_time(inode->i_sb) : CURRENT_TIME_SEC; 238 } 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 /** 258 * ubifs_get_lprops - get reference to LEB properties. 259 * @c: the UBIFS file-system description object 260 * 261 * This function locks lprops. Lprops have to be unlocked by 262 * 'ubifs_release_lprops()'. 263 */ 264 static inline void ubifs_get_lprops(struct ubifs_info *c) 265 { 266 mutex_lock(&c->lp_mutex); 267 } 268 269 /** 270 * ubifs_release_lprops - release lprops lock. 271 * @c: the UBIFS file-system description object 272 * 273 * This function has to be called after each 'ubifs_get_lprops()' call to 274 * unlock lprops. 275 */ 276 static inline void ubifs_release_lprops(struct ubifs_info *c) 277 { 278 ubifs_assert(mutex_is_locked(&c->lp_mutex)); 279 ubifs_assert(c->lst.empty_lebs >= 0 && 280 c->lst.empty_lebs <= c->main_lebs); 281 mutex_unlock(&c->lp_mutex); 282 } 283 284 /** 285 * ubifs_next_log_lnum - switch to the next log LEB. 286 * @c: UBIFS file-system description object 287 * @lnum: current log LEB 288 * 289 * This helper function returns the log LEB number which goes next after LEB 290 * 'lnum'. 291 */ 292 static inline int ubifs_next_log_lnum(const struct ubifs_info *c, int lnum) 293 { 294 lnum += 1; 295 if (lnum > c->log_last) 296 lnum = UBIFS_LOG_LNUM; 297 298 return lnum; 299 } 300 301 #endif /* __UBIFS_MISC_H__ */ 302