1 /* SPDX-License-Identifier: GPL-2.0-only */ 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flags); 27 } 28 29 /** 30 * ubifs_zn_obsolete - check if znode is obsolete. 31 * @znode: znode to check 32 * 33 * This helper function returns %1 if @znode is obsolete and %0 otherwise. 34 */ 35 static inline int ubifs_zn_obsolete(const struct ubifs_znode *znode) 36 { 37 return !!test_bit(OBSOLETE_ZNODE, &znode-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 * @c: the UBIFS file-system description object 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(struct ubifs_info *c, int compr_type) 102 { 103 ubifs_assert(c, 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 * @c: the UBIFS file-system description object 111 * 112 * This function returns compressor type string. 113 */ 114 static inline const char *ubifs_compr_name(struct ubifs_info *c, int compr_type) 115 { 116 ubifs_assert(c, compr_type >= 0 && compr_type < UBIFS_COMPR_TYPES_CNT); 117 return ubifs_compressors[compr_type]->name; 118 } 119 120 /** 121 * ubifs_wbuf_sync - synchronize write-buffer. 122 * @wbuf: write-buffer to synchronize 123 * 124 * This is the same as 'ubifs_wbuf_sync_nolock()' but it does not assume 125 * that the write-buffer is already locked. 126 */ 127 static inline int ubifs_wbuf_sync(struct ubifs_wbuf *wbuf) 128 { 129 int err; 130 131 mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead); 132 err = ubifs_wbuf_sync_nolock(wbuf); 133 mutex_unlock(&wbuf->io_mutex); 134 return err; 135 } 136 137 /** 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 dev->new = cpu_to_le32(new_encode_dev(rdev)); 149 return sizeof(dev->new); 150 } 151 152 /** 153 * ubifs_add_dirt - add dirty space to LEB properties. 154 * @c: the UBIFS file-system description object 155 * @lnum: LEB to add dirty space for 156 * @dirty: dirty space to add 157 * 158 * This is a helper function which increased amount of dirty LEB space. Returns 159 * zero in case of success and a negative error code in case of failure. 160 */ 161 static inline int ubifs_add_dirt(struct ubifs_info *c, int lnum, int dirty) 162 { 163 return ubifs_update_one_lp(c, lnum, LPROPS_NC, dirty, 0, 0); 164 } 165 166 /** 167 * ubifs_return_leb - return LEB to lprops. 168 * @c: the UBIFS file-system description object 169 * @lnum: LEB to return 170 * 171 * This helper function cleans the "taken" flag of a logical eraseblock in the 172 * lprops. Returns zero in case of success and a negative error code in case of 173 * failure. 174 */ 175 static inline int ubifs_return_leb(struct ubifs_info *c, int lnum) 176 { 177 return ubifs_change_one_lp(c, lnum, LPROPS_NC, LPROPS_NC, 0, 178 LPROPS_TAKEN, 0); 179 } 180 181 /** 182 * ubifs_idx_node_sz - return index node size. 183 * @c: the UBIFS file-system description object 184 * @child_cnt: number of children of this index node 185 */ 186 static inline int ubifs_idx_node_sz(const struct ubifs_info *c, int child_cnt) 187 { 188 return UBIFS_IDX_NODE_SZ + (UBIFS_BRANCH_SZ + c->key_len + c->hash_len) 189 * child_cnt; 190 } 191 192 /** 193 * ubifs_idx_branch - return pointer to an index branch. 194 * @c: the UBIFS file-system description object 195 * @idx: index node 196 * @bnum: branch number 197 */ 198 static inline 199 struct ubifs_branch *ubifs_idx_branch(const struct ubifs_info *c, 200 const struct ubifs_idx_node *idx, 201 int bnum) 202 { 203 return (struct ubifs_branch *)((void *)idx->branches + 204 (UBIFS_BRANCH_SZ + c->key_len + c->hash_len) * bnum); 205 } 206 207 /** 208 * ubifs_idx_key - return pointer to an index key. 209 * @c: the UBIFS file-system description object 210 * @idx: index node 211 */ 212 static inline void *ubifs_idx_key(const struct ubifs_info *c, 213 const struct ubifs_idx_node *idx) 214 { 215 return (void *)((struct ubifs_branch *)idx->branches)->key; 216 } 217 218 /** 219 * ubifs_tnc_lookup - look up a file-system node. 220 * @c: UBIFS file-system description object 221 * @key: node key to lookup 222 * @node: the node is returned here 223 * 224 * This function look up and reads node with key @key. The caller has to make 225 * sure the @node buffer is large enough to fit the node. Returns zero in case 226 * of success, %-ENOENT if the node was not found, and a negative error code in 227 * case of failure. 228 */ 229 static inline int ubifs_tnc_lookup(struct ubifs_info *c, 230 const union ubifs_key *key, void *node) 231 { 232 return ubifs_tnc_locate(c, key, node, NULL, NULL); 233 } 234 235 /** 236 * ubifs_get_lprops - get reference to LEB properties. 237 * @c: the UBIFS file-system description object 238 * 239 * This function locks lprops. Lprops have to be unlocked by 240 * 'ubifs_release_lprops()'. 241 */ 242 static inline void ubifs_get_lprops(struct ubifs_info *c) 243 { 244 mutex_lock(&c->lp_mutex); 245 } 246 247 /** 248 * ubifs_release_lprops - release lprops lock. 249 * @c: the UBIFS file-system description object 250 * 251 * This function has to be called after each 'ubifs_get_lprops()' call to 252 * unlock lprops. 253 */ 254 static inline void ubifs_release_lprops(struct ubifs_info *c) 255 { 256 ubifs_assert(c, mutex_is_locked(&c->lp_mutex)); 257 ubifs_assert(c, c->lst.empty_lebs >= 0 && 258 c->lst.empty_lebs <= c->main_lebs); 259 mutex_unlock(&c->lp_mutex); 260 } 261 262 /** 263 * ubifs_next_log_lnum - switch to the next log LEB. 264 * @c: UBIFS file-system description object 265 * @lnum: current log LEB 266 * 267 * This helper function returns the log LEB number which goes next after LEB 268 * 'lnum'. 269 */ 270 static inline int ubifs_next_log_lnum(const struct ubifs_info *c, int lnum) 271 { 272 lnum += 1; 273 if (lnum > c->log_last) 274 lnum = UBIFS_LOG_LNUM; 275 276 return lnum; 277 } 278 279 static inline int ubifs_xattr_max_cnt(struct ubifs_info *c) 280 { 281 int max_xattrs = (c->leb_size / 2) / UBIFS_INO_NODE_SZ; 282 283 ubifs_assert(c, max_xattrs < c->max_orphans); 284 return max_xattrs; 285 } 286 287 const char *ubifs_assert_action_name(struct ubifs_info *c); 288 289 #endif /* __UBIFS_MISC_H__ */ 290