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* ubifs_zn_obsolete - check if znode is obsolete.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* This helper function returns %1 if @znode is obsolete and %0 otherwise.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