fs/ubifs/misc.h

   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  30  * ubifs_zn_obsolete - check if znode is obsolete.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  33  * This helper function returns %1 if @znode is obsolete and %0 otherwise.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__ */