fs/ubifs/misc.h - kernel/msm-4.9 - Gitiles

 /*
  * This file is part of UBIFS.
  *
  * Copyright (C) 2006-2008 Nokia Corporation
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 as published by
  * the Free Software Foundation.
  *
  * This program is distributed in the hope that it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  * more details.
  *
  * You should have received a copy of the GNU General Public License along with
  * this program; if not, write to the Free Software Foundation, Inc., 51
  * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  *
  * 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_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_ro_mode - switch UBIFS to read read-only mode.
  * @c: UBIFS file-system description object
  * @err: error code which is the reason of switching to R/O mode
  */
 static inline void ubifs_ro_mode(struct ubifs_info *c, int err)
 {
 	if (!c->ro_media) {
 		c->ro_media = 1;
 		ubifs_warn("switched to read-only mode, error %d", err);
 		dbg_dump_stack();
 	}
 }

 /**
  * 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;
 }

 /**
  * ubifs_leb_unmap - unmap an LEB.
  * @c: UBIFS file-system description object
  * @lnum: LEB number to unmap
  *
  * This function returns %0 on success and a negative error code on failure.
  */
 static inline int ubifs_leb_unmap(const struct ubifs_info *c, int lnum)
 {
 	int err;

 	if (c->ro_media)
 		return -EROFS;
 	err = ubi_leb_unmap(c->ubi, lnum);
 	if (err) {
 		ubifs_err("unmap LEB %d failed, error %d", lnum, err);
 		return err;
 	}

 	return 0;
 }

 /**
  * ubifs_leb_write - write to a LEB.
  * @c: UBIFS file-system description object
  * @lnum: LEB number to write
  * @buf: buffer to write from
  * @offs: offset within LEB to write to
  * @len: length to write
  * @dtype: data type
  *
  * This function returns %0 on success and a negative error code on failure.
  */
 static inline int ubifs_leb_write(const struct ubifs_info *c, int lnum,
 				  const void *buf, int offs, int len, int dtype)
 {
 	int err;

 	if (c->ro_media)
 		return -EROFS;
 	err = ubi_leb_write(c->ubi, lnum, buf, offs, len, dtype);
 	if (err) {
 		ubifs_err("writing %d bytes at %d:%d, error %d",
 			  len, lnum, offs, err);
 		return err;
 	}

 	return 0;
 }

 /**
  * ubifs_leb_change - atomic LEB change.
  * @c: UBIFS file-system description object
  * @lnum: LEB number to write
  * @buf: buffer to write from
  * @len: length to write
  * @dtype: data type
  *
  * This function returns %0 on success and a negative error code on failure.
  */
 static inline int ubifs_leb_change(const struct ubifs_info *c, int lnum,
 				   const void *buf, int len, int dtype)
 {
 	int err;

 	if (c->ro_media)
 		return -EROFS;
 	err = ubi_leb_change(c->ubi, lnum, buf, len, dtype);
 	if (err) {
 		ubifs_err("changing %d bytes in LEB %d, error %d",
 			  len, lnum, err);
 		return err;
 	}

 	return 0;
 }

 /**
  * 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);
 	}
 }

 /**
  * 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)
 {
 	return (void *)((struct ubifs_branch *)idx->branches)->key;
 }

 /**
  * ubifs_reported_space - calculate reported free space.
  * @c: the UBIFS file-system description object
  * @free: amount of free space
  *
  * This function calculates amount of free space which will be reported to
  * user-space. User-space application tend to expect that if the file-system
  * (e.g., via the 'statfs()' call) reports that it has N bytes available, they
  * are able to write a file of size N. UBIFS attaches node headers to each data
  * node and it has to write indexind nodes as well. This introduces additional
  * overhead, and UBIFS it has to report sligtly less free space to meet the
  * above expectetion.
  *
  * This function assumes free space is made up of uncompressed data nodes and
  * full index nodes (one per data node, doubled because we always allow enough
  * space to write the index twice).
  *
  * Note, the calculation is pessimistic, which means that most of the time
  * UBIFS reports less space than it actually has.
  */
 static inline long long ubifs_reported_space(const struct ubifs_info *c,
 					     uint64_t free)
 {
 	int divisor, factor;

 	divisor = UBIFS_MAX_DATA_NODE_SZ + (c->max_idx_node_sz << 1);
 	factor = UBIFS_MAX_DATA_NODE_SZ - UBIFS_DATA_NODE_SZ;
 	do_div(free, divisor);

 	return free * factor;
 }

 /**
  * 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;
 }

 #endif /* __UBIFS_MISC_H__ */
	/*
	* This file is part of UBIFS.
	*
	* Copyright (C) 2006-2008 Nokia Corporation
	*
	* This program is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 as published by
	* the Free Software Foundation.
	*
	* This program is distributed in the hope that it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
	* more details.
	*
	* You should have received a copy of the GNU General Public License along with
	* this program; if not, write to the Free Software Foundation, Inc., 51
	* Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
	*
	* 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_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_ro_mode - switch UBIFS to read read-only mode.
	* @c: UBIFS file-system description object
	* @err: error code which is the reason of switching to R/O mode
	*/
	static inline void ubifs_ro_mode(struct ubifs_info *c, int err)
	{
	if (!c->ro_media) {
	c->ro_media = 1;
	ubifs_warn("switched to read-only mode, error %d", err);
	dbg_dump_stack();
	}
	}

	/**
	* 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;
	}

	/**
	* ubifs_leb_unmap - unmap an LEB.
	* @c: UBIFS file-system description object
	* @lnum: LEB number to unmap
	*
	* This function returns %0 on success and a negative error code on failure.
	*/
	static inline int ubifs_leb_unmap(const struct ubifs_info *c, int lnum)
	{
	int err;

	if (c->ro_media)
	return -EROFS;
	err = ubi_leb_unmap(c->ubi, lnum);
	if (err) {
	ubifs_err("unmap LEB %d failed, error %d", lnum, err);
	return err;
	}

	return 0;
	}

	/**
	* ubifs_leb_write - write to a LEB.
	* @c: UBIFS file-system description object
	* @lnum: LEB number to write
	* @buf: buffer to write from
	* @offs: offset within LEB to write to
	* @len: length to write
	* @dtype: data type
	*
	* This function returns %0 on success and a negative error code on failure.
	*/
	static inline int ubifs_leb_write(const struct ubifs_info *c, int lnum,
	const void *buf, int offs, int len, int dtype)
	{
	int err;

	if (c->ro_media)
	return -EROFS;
	err = ubi_leb_write(c->ubi, lnum, buf, offs, len, dtype);
	if (err) {
	ubifs_err("writing %d bytes at %d:%d, error %d",
	len, lnum, offs, err);
	return err;
	}

	return 0;
	}

	/**
	* ubifs_leb_change - atomic LEB change.
	* @c: UBIFS file-system description object
	* @lnum: LEB number to write
	* @buf: buffer to write from
	* @len: length to write
	* @dtype: data type
	*
	* This function returns %0 on success and a negative error code on failure.
	*/
	static inline int ubifs_leb_change(const struct ubifs_info *c, int lnum,
	const void *buf, int len, int dtype)
	{
	int err;

	if (c->ro_media)
	return -EROFS;
	err = ubi_leb_change(c->ubi, lnum, buf, len, dtype);
	if (err) {
	ubifs_err("changing %d bytes in LEB %d, error %d",
	len, lnum, err);
	return err;
	}

	return 0;
	}

	/**
	* 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);
	}
	}

	/**
	* 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)
	{
	return (void )((struct ubifs_branch )idx->branches)->key;
	}

	/**
	* ubifs_reported_space - calculate reported free space.
	* @c: the UBIFS file-system description object
	* @free: amount of free space
	*
	* This function calculates amount of free space which will be reported to
	* user-space. User-space application tend to expect that if the file-system
	* (e.g., via the 'statfs()' call) reports that it has N bytes available, they
	* are able to write a file of size N. UBIFS attaches node headers to each data
	* node and it has to write indexind nodes as well. This introduces additional
	* overhead, and UBIFS it has to report sligtly less free space to meet the
	* above expectetion.
	*
	* This function assumes free space is made up of uncompressed data nodes and
	* full index nodes (one per data node, doubled because we always allow enough
	* space to write the index twice).
	*
	* Note, the calculation is pessimistic, which means that most of the time
	* UBIFS reports less space than it actually has.
	*/
	static inline long long ubifs_reported_space(const struct ubifs_info *c,
	uint64_t free)
	{
	int divisor, factor;

	divisor = UBIFS_MAX_DATA_NODE_SZ + (c->max_idx_node_sz << 1);
	factor = UBIFS_MAX_DATA_NODE_SZ - UBIFS_DATA_NODE_SZ;
	do_div(free, divisor);

	return free * factor;
	}

	/**
	* 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;
	}

	#endif /* __UBIFS_MISC_H__ */