1 /* SPDX-License-Identifier: GPL-2.0+ */ 2 /* 3 * This file is part of UBIFS. 4 * 5 * Copyright (C) 2006-2008 Nokia Corporation 6 * 7 * Authors: Artem Bityutskiy (Битюцкий Артём) 8 * Adrian Hunter 9 */ 10 11 /* 12 * This file contains miscellaneous helper functions. 13 */ 14 15 #ifndef __UBIFS_MISC_H__ 16 #define __UBIFS_MISC_H__ 17 18 /** 19 * ubifs_zn_dirty - check if znode is dirty. 20 * @znode: znode to check 21 * 22 * This helper function returns %1 if @znode is dirty and %0 otherwise. 23 */ 24 static inline int ubifs_zn_dirty(const struct ubifs_znode *znode) 25 { 26 return !!test_bit(DIRTY_ZNODE, &znode->flags); 27 } 28 29 /** 30 * ubifs_zn_obsolete - check if znode is obsolete. 31 * @znode: znode to check 32 * 33 * This helper function returns %1 if @znode is obsolete and %0 otherwise. 34 */ 35 static inline int ubifs_zn_obsolete(const struct ubifs_znode *znode) 36 { 37 return !!test_bit(OBSOLETE_ZNODE, &znode->flags); 38 } 39 40 /** 41 * ubifs_zn_cow - check if znode has to be copied on write. 42 * @znode: znode to check 43 * 44 * This helper function returns %1 if @znode is has COW flag set and %0 45 * otherwise. 46 */ 47 static inline int ubifs_zn_cow(const struct ubifs_znode *znode) 48 { 49 return !!test_bit(COW_ZNODE, &znode->flags); 50 } 51 52 /** 53 * ubifs_wake_up_bgt - wake up background thread. 54 * @c: UBIFS file-system description object 55 */ 56 static inline void ubifs_wake_up_bgt(struct ubifs_info *c) 57 { 58 if (c->bgt && !c->need_bgt) { 59 c->need_bgt = 1; 60 wake_up_process(c->bgt); 61 } 62 } 63 64 /** 65 * ubifs_tnc_find_child - find next child in znode. 66 * @znode: znode to search at 67 * @start: the zbranch index to start at 68 * 69 * This helper function looks for znode child starting at index @start. Returns 70 * the child or %NULL if no children were found. 71 */ 72 static inline struct ubifs_znode * 73 ubifs_tnc_find_child(struct ubifs_znode *znode, int start) 74 { 75 while (start < znode->child_cnt) { 76 if (znode->zbranch[start].znode) 77 return znode->zbranch[start].znode; 78 start += 1; 79 } 80 81 return NULL; 82 } 83 84 /** 85 * ubifs_inode - get UBIFS inode information by VFS 'struct inode' object. 86 * @inode: the VFS 'struct inode' pointer 87 */ 88 static inline struct ubifs_inode *ubifs_inode(const struct inode *inode) 89 { 90 return container_of(inode, struct ubifs_inode, vfs_inode); 91 } 92 93 /** 94 * ubifs_compr_present - check if compressor was compiled in. 95 * @compr_type: compressor type to check 96 * 97 * This function returns %1 of compressor of type @compr_type is present, and 98 * %0 if not. 99 */ 100 static inline int ubifs_compr_present(int compr_type) 101 { 102 ubifs_assert(compr_type >= 0 && compr_type < UBIFS_COMPR_TYPES_CNT); 103 return !!ubifs_compressors[compr_type]->capi_name; 104 } 105 106 /** 107 * ubifs_compr_name - get compressor name string by its type. 108 * @compr_type: compressor type 109 * 110 * This function returns compressor type string. 111 */ 112 static inline const char *ubifs_compr_name(int compr_type) 113 { 114 ubifs_assert(compr_type >= 0 && compr_type < UBIFS_COMPR_TYPES_CNT); 115 return ubifs_compressors[compr_type]->name; 116 } 117 118 /** 119 * ubifs_wbuf_sync - synchronize write-buffer. 120 * @wbuf: write-buffer to synchronize 121 * 122 * This is the same as as 'ubifs_wbuf_sync_nolock()' but it does not assume 123 * that the write-buffer is already locked. 124 */ 125 static inline int ubifs_wbuf_sync(struct ubifs_wbuf *wbuf) 126 { 127 int err; 128 129 mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead); 130 err = ubifs_wbuf_sync_nolock(wbuf); 131 mutex_unlock(&wbuf->io_mutex); 132 return err; 133 } 134 135 #ifndef __UBOOT__ 136 /** 137 * ubifs_encode_dev - encode device node IDs. 138 * @dev: UBIFS device node information 139 * @rdev: device IDs to encode 140 * 141 * This is a helper function which encodes major/minor numbers of a device node 142 * into UBIFS device node description. We use standard Linux "new" and "huge" 143 * encodings. 144 */ 145 static inline int ubifs_encode_dev(union ubifs_dev_desc *dev, dev_t rdev) 146 { 147 if (new_valid_dev(rdev)) { 148 dev->new = cpu_to_le32(new_encode_dev(rdev)); 149 return sizeof(dev->new); 150 } else { 151 dev->huge = cpu_to_le64(huge_encode_dev(rdev)); 152 return sizeof(dev->huge); 153 } 154 } 155 #endif 156 157 /** 158 * ubifs_add_dirt - add dirty space to LEB properties. 159 * @c: the UBIFS file-system description object 160 * @lnum: LEB to add dirty space for 161 * @dirty: dirty space to add 162 * 163 * This is a helper function which increased amount of dirty LEB space. Returns 164 * zero in case of success and a negative error code in case of failure. 165 */ 166 static inline int ubifs_add_dirt(struct ubifs_info *c, int lnum, int dirty) 167 { 168 return ubifs_update_one_lp(c, lnum, LPROPS_NC, dirty, 0, 0); 169 } 170 171 /** 172 * ubifs_return_leb - return LEB to lprops. 173 * @c: the UBIFS file-system description object 174 * @lnum: LEB to return 175 * 176 * This helper function cleans the "taken" flag of a logical eraseblock in the 177 * lprops. Returns zero in case of success and a negative error code in case of 178 * failure. 179 */ 180 static inline int ubifs_return_leb(struct ubifs_info *c, int lnum) 181 { 182 return ubifs_change_one_lp(c, lnum, LPROPS_NC, LPROPS_NC, 0, 183 LPROPS_TAKEN, 0); 184 } 185 186 /** 187 * ubifs_idx_node_sz - return index node size. 188 * @c: the UBIFS file-system description object 189 * @child_cnt: number of children of this index node 190 */ 191 static inline int ubifs_idx_node_sz(const struct ubifs_info *c, int child_cnt) 192 { 193 return UBIFS_IDX_NODE_SZ + (UBIFS_BRANCH_SZ + c->key_len) * child_cnt; 194 } 195 196 /** 197 * ubifs_idx_branch - return pointer to an index branch. 198 * @c: the UBIFS file-system description object 199 * @idx: index node 200 * @bnum: branch number 201 */ 202 static inline 203 struct ubifs_branch *ubifs_idx_branch(const struct ubifs_info *c, 204 const struct ubifs_idx_node *idx, 205 int bnum) 206 { 207 return (struct ubifs_branch *)((void *)idx->branches + 208 (UBIFS_BRANCH_SZ + c->key_len) * bnum); 209 } 210 211 /** 212 * ubifs_idx_key - return pointer to an index key. 213 * @c: the UBIFS file-system description object 214 * @idx: index node 215 */ 216 static inline void *ubifs_idx_key(const struct ubifs_info *c, 217 const struct ubifs_idx_node *idx) 218 { 219 #ifndef __UBOOT__ 220 return (void *)((struct ubifs_branch *)idx->branches)->key; 221 #else 222 struct ubifs_branch *tmp; 223 224 tmp = (struct ubifs_branch *)idx->branches; 225 return (void *)tmp->key; 226 #endif 227 } 228 229 /** 230 * ubifs_current_time - round current time to time granularity. 231 * @inode: inode 232 */ 233 static inline struct timespec ubifs_current_time(struct inode *inode) 234 { 235 return (inode->i_sb->s_time_gran < NSEC_PER_SEC) ? 236 current_fs_time(inode->i_sb) : CURRENT_TIME_SEC; 237 } 238 239 /** 240 * ubifs_tnc_lookup - look up a file-system node. 241 * @c: UBIFS file-system description object 242 * @key: node key to lookup 243 * @node: the node is returned here 244 * 245 * This function look up and reads node with key @key. The caller has to make 246 * sure the @node buffer is large enough to fit the node. Returns zero in case 247 * of success, %-ENOENT if the node was not found, and a negative error code in 248 * case of failure. 249 */ 250 static inline int ubifs_tnc_lookup(struct ubifs_info *c, 251 const union ubifs_key *key, void *node) 252 { 253 return ubifs_tnc_locate(c, key, node, NULL, NULL); 254 } 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 /** 269 * ubifs_release_lprops - release lprops lock. 270 * @c: the UBIFS file-system description object 271 * 272 * This function has to be called after each 'ubifs_get_lprops()' call to 273 * unlock lprops. 274 */ 275 static inline void ubifs_release_lprops(struct ubifs_info *c) 276 { 277 ubifs_assert(mutex_is_locked(&c->lp_mutex)); 278 ubifs_assert(c->lst.empty_lebs >= 0 && 279 c->lst.empty_lebs <= c->main_lebs); 280 mutex_unlock(&c->lp_mutex); 281 } 282 283 /** 284 * ubifs_next_log_lnum - switch to the next log LEB. 285 * @c: UBIFS file-system description object 286 * @lnum: current log LEB 287 * 288 * This helper function returns the log LEB number which goes next after LEB 289 * 'lnum'. 290 */ 291 static inline int ubifs_next_log_lnum(const struct ubifs_info *c, int lnum) 292 { 293 lnum += 1; 294 if (lnum > c->log_last) 295 lnum = UBIFS_LOG_LNUM; 296 297 return lnum; 298 } 299 300 #endif /* __UBIFS_MISC_H__ */ 301