text: /* SPDX-License-Identifier: GPL-2.0+ */
  /*
   * This file is part of UBIFS.
   *
   * Copyright (C) 2006-2008 Nokia Corporation
   *
   * Authors: Artem Bityutskiy (Битюцкий Артём)
   *          Adrian Hunter
   */
  
  /*
   * This file contains miscellaneous helper functions.
   */
  
  #ifndef __UBIFS_MISC_H__
  #define __UBIFS_MISC_H__
  
  /**
   * ubifs_zn_dirty - check if znode is dirty.
   * @znode: znode to check
   *
   * This helper function returns %1 if @znode is dirty and %0 otherwise.
   */
  static inline int ubifs_zn_dirty(const struct ubifs_znode *znode)
  {
  	return !!test_bit(DIRTY_ZNODE, &znode->flags);
  }
  
  /**
   * ubifs_zn_obsolete - check if znode is obsolete.
   * @znode: znode to check
   *
   * This helper function returns %1 if @znode is obsolete and %0 otherwise.
   */
  static inline int ubifs_zn_obsolete(const struct ubifs_znode *znode)
  {
  	return !!test_bit(OBSOLETE_ZNODE, &znode->flags);
  }
  
  /**
   * ubifs_zn_cow - check if znode has to be copied on write.
   * @znode: znode to check
   *
   * This helper function returns %1 if @znode is has COW flag set and %0
   * otherwise.
   */
  static inline int ubifs_zn_cow(const struct ubifs_znode *znode)
  {
  	return !!test_bit(COW_ZNODE, &znode->flags);
  }
  
  /**
   * ubifs_wake_up_bgt - wake up background thread.
   * @c: UBIFS file-system description object
   */
  static inline void ubifs_wake_up_bgt(struct ubifs_info *c)
  {
  	if (c->bgt && !c->need_bgt) {
  		c->need_bgt = 1;
  		wake_up_process(c->bgt);
  	}
  }
  
  /**
   * ubifs_tnc_find_child - find next child in znode.
   * @znode: znode to search at
   * @start: the zbranch index to start at
   *
   * This helper function looks for znode child starting at index @start. Returns
   * the child or %NULL if no children were found.
   */
  static inline struct ubifs_znode *
  ubifs_tnc_find_child(struct ubifs_znode *znode, int start)
  {
  	while (start < znode->child_cnt) {
  		if (znode->zbranch[start].znode)
  			return znode->zbranch[start].znode;
  		start += 1;
  	}
  
  	return NULL;
  }
  
  /**
   * ubifs_inode - get UBIFS inode information by VFS 'struct inode' object.
   * @inode: the VFS 'struct inode' pointer
   */
  static inline struct ubifs_inode *ubifs_inode(const struct inode *inode)
  {
  	return container_of(inode, struct ubifs_inode, vfs_inode);
  }
  
  /**
   * ubifs_compr_present - check if compressor was compiled in.
   * @compr_type: compressor type to check
   *
   * This function returns %1 of compressor of type @compr_type is present, and
   * %0 if not.
   */
  static inline int ubifs_compr_present(int compr_type)
  {
  	ubifs_assert(compr_type >= 0 && compr_type < UBIFS_COMPR_TYPES_CNT);
  	return !!ubifs_compressors[compr_type]->capi_name;
  }
  
  /**
   * ubifs_compr_name - get compressor name string by its type.
   * @compr_type: compressor type
   *
   * This function returns compressor type string.
   */
  static inline const char *ubifs_compr_name(int compr_type)
  {
  	ubifs_assert(compr_type >= 0 && compr_type < UBIFS_COMPR_TYPES_CNT);
  	return ubifs_compressors[compr_type]->name;
  }
  
  /**
   * ubifs_wbuf_sync - synchronize write-buffer.
   * @wbuf: write-buffer to synchronize
   *
   * This is the same as as 'ubifs_wbuf_sync_nolock()' but it does not assume
   * that the write-buffer is already locked.
   */
  static inline int ubifs_wbuf_sync(struct ubifs_wbuf *wbuf)
  {
  	int err;
  
  	mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead);
  	err = ubifs_wbuf_sync_nolock(wbuf);
  	mutex_unlock(&wbuf->io_mutex);
  	return err;
  }
  
  #ifndef __UBOOT__
  /**
   * ubifs_encode_dev - encode device node IDs.
   * @dev: UBIFS device node information
   * @rdev: device IDs to encode
   *
   * This is a helper function which encodes major/minor numbers of a device node
   * into UBIFS device node description. We use standard Linux "new" and "huge"
   * encodings.
   */
  static inline int ubifs_encode_dev(union ubifs_dev_desc *dev, dev_t rdev)
  {
  	if (new_valid_dev(rdev)) {
  		dev->new = cpu_to_le32(new_encode_dev(rdev));
  		return sizeof(dev->new);
  	} else {
  		dev->huge = cpu_to_le64(huge_encode_dev(rdev));
  		return sizeof(dev->huge);
  	}
  }
  #endif
  
  /**
   * ubifs_add_dirt - add dirty space to LEB properties.
   * @c: the UBIFS file-system description object
   * @lnum: LEB to add dirty space for
   * @dirty: dirty space to add
   *
   * This is a helper function which increased amount of dirty LEB space. Returns
   * zero in case of success and a negative error code in case of failure.
   */
  static inline int ubifs_add_dirt(struct ubifs_info *c, int lnum, int dirty)
  {
  	return ubifs_update_one_lp(c, lnum, LPROPS_NC, dirty, 0, 0);
  }
  
  /**
   * ubifs_return_leb - return LEB to lprops.
   * @c: the UBIFS file-system description object
   * @lnum: LEB to return
   *
   * This helper function cleans the "taken" flag of a logical eraseblock in the
   * lprops. Returns zero in case of success and a negative error code in case of
   * failure.
   */
  static inline int ubifs_return_leb(struct ubifs_info *c, int lnum)
  {
  	return ubifs_change_one_lp(c, lnum, LPROPS_NC, LPROPS_NC, 0,
  				   LPROPS_TAKEN, 0);
  }
  
  /**
   * ubifs_idx_node_sz - return index node size.
   * @c: the UBIFS file-system description object
   * @child_cnt: number of children of this index node
   */
  static inline int ubifs_idx_node_sz(const struct ubifs_info *c, int child_cnt)
  {
  	return UBIFS_IDX_NODE_SZ + (UBIFS_BRANCH_SZ + c->key_len) * child_cnt;
  }
  
  /**
   * ubifs_idx_branch - return pointer to an index branch.
   * @c: the UBIFS file-system description object
   * @idx: index node
   * @bnum: branch number
   */
  static inline
  struct ubifs_branch *ubifs_idx_branch(const struct ubifs_info *c,
  				      const struct ubifs_idx_node *idx,
  				      int bnum)
  {
  	return (struct ubifs_branch *)((void *)idx->branches +
  				       (UBIFS_BRANCH_SZ + c->key_len) * bnum);
  }
  
  /**
   * ubifs_idx_key - return pointer to an index key.
   * @c: the UBIFS file-system description object
   * @idx: index node
   */
  static inline void *ubifs_idx_key(const struct ubifs_info *c,
  				  const struct ubifs_idx_node *idx)
  {
  #ifndef __UBOOT__
  	return (void *)((struct ubifs_branch *)idx->branches)->key;
  #else
  	struct ubifs_branch *tmp;
  
  	tmp = (struct ubifs_branch *)idx->branches;
  	return (void *)tmp->key;
  #endif
  }
  
  /**
   * ubifs_current_time - round current time to time granularity.
   * @inode: inode
   */
  static inline struct timespec ubifs_current_time(struct inode *inode)
  {
  	return (inode->i_sb->s_time_gran < NSEC_PER_SEC) ?
  		current_fs_time(inode->i_sb) : CURRENT_TIME_SEC;
  }
  
  /**
   * ubifs_tnc_lookup - look up a file-system node.
   * @c: UBIFS file-system description object
   * @key: node key to lookup
   * @node: the node is returned here
   *
   * This function look up and reads node with key @key. The caller has to make
   * sure the @node buffer is large enough to fit the node. Returns zero in case
   * of success, %-ENOENT if the node was not found, and a negative error code in
   * case of failure.
   */
  static inline int ubifs_tnc_lookup(struct ubifs_info *c,
  				   const union ubifs_key *key, void *node)
  {
  	return ubifs_tnc_locate(c, key, node, NULL, NULL);
  }
  
  /**
   * ubifs_get_lprops - get reference to LEB properties.
   * @c: the UBIFS file-system description object
   *
   * This function locks lprops. Lprops have to be unlocked by
   * 'ubifs_release_lprops()'.
   */
  static inline void ubifs_get_lprops(struct ubifs_info *c)
  {
  	mutex_lock(&c->lp_mutex);
  }
  
  /**
   * ubifs_release_lprops - release lprops lock.
   * @c: the UBIFS file-system description object
   *
   * This function has to be called after each 'ubifs_get_lprops()' call to
   * unlock lprops.
   */
  static inline void ubifs_release_lprops(struct ubifs_info *c)
  {
  	ubifs_assert(mutex_is_locked(&c->lp_mutex));
  	ubifs_assert(c->lst.empty_lebs >= 0 &&
  		     c->lst.empty_lebs <= c->main_lebs);
  	mutex_unlock(&c->lp_mutex);
  }
  
  /**
   * ubifs_next_log_lnum - switch to the next log LEB.
   * @c: UBIFS file-system description object
   * @lnum: current log LEB
   *
   * This helper function returns the log LEB number which goes next after LEB
   * 'lnum'.
   */
  static inline int ubifs_next_log_lnum(const struct ubifs_info *c, int lnum)
  {
  	lnum += 1;
  	if (lnum > c->log_last)
  		lnum = UBIFS_LOG_LNUM;
  
  	return lnum;
  }
  
  #endif /* __UBIFS_MISC_H__ */
  