ref: 1700fa24e5996142d1952d4ee070d7ddddbe37ef
dir: /include/ext4_dir.h/
/*
* Copyright (c) 2013 Grzegorz Kostka ([email protected])
*
*
* HelenOS:
* Copyright (c) 2012 Martin Sucha
* Copyright (c) 2012 Frantisek Princ
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* - The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/** @addtogroup lwext4
* @{
*/
/**
* @file ext4_dir.h
* @brief Directory handle procedures.
*/
#ifndef EXT4_DIR_H_
#define EXT4_DIR_H_
#ifdef __cplusplus
extern "C" {
#endif
#include "ext4_config.h"
#include "ext4_types.h"
#include "ext4_misc.h"
#include "ext4_blockdev.h"
#include "ext4_super.h"
#include <stdint.h>
struct ext4_dir_iter {
struct ext4_inode_ref *inode_ref;
struct ext4_block curr_blk;
uint64_t curr_off;
struct ext4_dir_en *curr;
};
struct ext4_dir_search_result {
struct ext4_block block;
struct ext4_dir_en *dentry;
};
/**@brief Get i-node number from directory entry.
* @param de Directory entry
* @return I-node number
*/
static inline uint32_t
ext4_dir_en_get_inode(struct ext4_dir_en *de)
{
return to_le32(de->inode);
}
/**@brief Set i-node number to directory entry.
* @param de Directory entry
* @param inode I-node number
*/
static inline void
ext4_dir_en_set_inode(struct ext4_dir_en *de, uint32_t inode)
{
de->inode = to_le32(inode);
}
/**@brief Set i-node number to directory entry. (For HTree root)
* @param de Directory entry
* @param inode I-node number
*/
static inline void
ext4_dx_dot_en_set_inode(struct ext4_dir_idx_dot_en *de, uint32_t inode)
{
de->inode = to_le32(inode);
}
/**@brief Get directory entry length.
* @param de Directory entry
* @return Entry length
*/
static inline uint16_t ext4_dir_en_get_entry_len(struct ext4_dir_en *de)
{
return to_le16(de->entry_len);
}
/**@brief Set directory entry length.
* @param de Directory entry
* @param length Entry length
*/
static inline void ext4_dir_en_set_entry_len(struct ext4_dir_en *de, uint16_t l)
{
de->entry_len = to_le16(l);
}
/**@brief Get directory entry name length.
* @param sb Superblock
* @param de Directory entry
* @return Entry name length
*/
static inline uint16_t ext4_dir_en_get_name_len(struct ext4_sblock *sb,
struct ext4_dir_en *de)
{
uint16_t v = de->name_len;
if ((ext4_get32(sb, rev_level) == 0) &&
(ext4_get32(sb, minor_rev_level) < 5))
v |= ((uint16_t)de->in.name_length_high) << 8;
return v;
}
/**@brief Set directory entry name length.
* @param sb Superblock
* @param de Directory entry
* @param length Entry name length
*/
static inline void ext4_dir_en_set_name_len(struct ext4_sblock *sb,
struct ext4_dir_en *de,
uint16_t len)
{
de->name_len = (len << 8) >> 8;
if ((ext4_get32(sb, rev_level) == 0) &&
(ext4_get32(sb, minor_rev_level) < 5))
de->in.name_length_high = len >> 8;
}
/**@brief Get i-node type of directory entry.
* @param sb Superblock
* @param de Directory entry
* @return I-node type (file, dir, etc.)
*/
static inline uint8_t ext4_dir_en_get_inode_type(struct ext4_sblock *sb,
struct ext4_dir_en *de)
{
if ((ext4_get32(sb, rev_level) > 0) ||
(ext4_get32(sb, minor_rev_level) >= 5))
return de->in.inode_type;
return EXT4_DE_UNKNOWN;
}
/**@brief Set i-node type of directory entry.
* @param sb Superblock
* @param de Directory entry
* @param type I-node type (file, dir, etc.)
*/
static inline void ext4_dir_en_set_inode_type(struct ext4_sblock *sb,
struct ext4_dir_en *de, uint8_t t)
{
if ((ext4_get32(sb, rev_level) > 0) ||
(ext4_get32(sb, minor_rev_level) >= 5))
de->in.inode_type = t;
}
/**@brief Verify checksum of a linear directory leaf block
* @param inode_ref Directory i-node
* @param dirent Linear directory leaf block
* @return true means the block passed checksum verification
*/
bool ext4_dir_csum_verify(struct ext4_inode_ref *inode_ref,
struct ext4_dir_en *dirent);
/**@brief Initialize directory iterator.
* Set position to the first valid entry from the required position.
* @param it Pointer to iterator to be initialized
* @param inode_ref Directory i-node
* @param pos Position to start reading entries from
* @return Error code
*/
int ext4_dir_iterator_init(struct ext4_dir_iter *it,
struct ext4_inode_ref *inode_ref, uint64_t pos);
/**@brief Jump to the next valid entry
* @param it Initialized iterator
* @return Error code
*/
int ext4_dir_iterator_next(struct ext4_dir_iter *it);
/**@brief Uninitialize directory iterator.
* Release all allocated structures.
* @param it Iterator to be finished
* @return Error code
*/
int ext4_dir_iterator_fini(struct ext4_dir_iter *it);
/**@brief Write directory entry to concrete data block.
* @param sb Superblock
* @param en Pointer to entry to be written
* @param entry_len Length of new entry
* @param child Child i-node to be written to new entry
* @param name Name of the new entry
* @param name_len Length of entry name
*/
void ext4_dir_write_entry(struct ext4_sblock *sb, struct ext4_dir_en *en,
uint16_t entry_len, struct ext4_inode_ref *child,
const char *name, size_t name_len);
/**@brief Add new entry to the directory.
* @param parent Directory i-node
* @param name Name of new entry
* @param child I-node to be referenced from new entry
* @return Error code
*/
int ext4_dir_add_entry(struct ext4_inode_ref *parent, const char *name,
uint32_t name_len, struct ext4_inode_ref *child);
/**@brief Find directory entry with passed name.
* @param result Result structure to be returned if entry found
* @param parent Directory i-node
* @param name Name of entry to be found
* @param name_len Name length
* @return Error code
*/
int ext4_dir_find_entry(struct ext4_dir_search_result *result,
struct ext4_inode_ref *parent, const char *name,
uint32_t name_len);
/**@brief Remove directory entry.
* @param parent Directory i-node
* @param name Name of the entry to be removed
* @param name_len Name length
* @return Error code
*/
int ext4_dir_remove_entry(struct ext4_inode_ref *parent, const char *name,
uint32_t name_len);
/**@brief Try to insert entry to concrete data block.
* @param sb Superblock
* @param inode_ref Directory i-node
* @param dst_blk Block to try to insert entry to
* @param child Child i-node to be inserted by new entry
* @param name Name of the new entry
* @param name_len Length of the new entry name
* @return Error code
*/
int ext4_dir_try_insert_entry(struct ext4_sblock *sb,
struct ext4_inode_ref *inode_ref,
struct ext4_block *dst_blk,
struct ext4_inode_ref *child, const char *name,
uint32_t name_len);
/**@brief Try to find entry in block by name.
* @param block Block containing entries
* @param sb Superblock
* @param name_len Length of entry name
* @param name Name of entry to be found
* @param res_entry Output pointer to found entry, NULL if not found
* @return Error code
*/
int ext4_dir_find_in_block(struct ext4_block *block, struct ext4_sblock *sb,
size_t name_len, const char *name,
struct ext4_dir_en **res_entry);
/**@brief Simple function to release allocated data from result.
* @param parent Parent inode
* @param result Search result to destroy
* @return Error code
*
*/
int ext4_dir_destroy_result(struct ext4_inode_ref *parent,
struct ext4_dir_search_result *result);
void ext4_dir_set_csum(struct ext4_inode_ref *inode_ref,
struct ext4_dir_en *dirent);
void ext4_dir_init_entry_tail(struct ext4_dir_entry_tail *t);
#ifdef __cplusplus
}
#endif
#endif /* EXT4_DIR_H_ */
/**
* @}
*/