ref: 67547995f1a63bb312be700b79cf14740cea7e1a
dir: /include/ext4_extent.h/
/*
* Copyright (c) 2013 Grzegorz Kostka (kostka.grzegorz@gmail.com)
*
*
* 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_extent.h
* @brief More complex filesystem functions.
*/
#ifndef EXT4_EXTENT_H_
#define EXT4_EXTENT_H_
#ifdef __cplusplus
extern "C" {
#endif
#include <ext4_config.h>
#include <ext4_types.h>
#include <ext4_misc.h>
#include <ext4_inode.h>
/*
* Array of ext4_ext_path contains path to some extent.
* Creation/lookup routines use it for traversal/splitting/etc.
* Truncate uses it to simulate recursive walking.
*/
struct ext4_extent_path {
struct ext4_block block;
uint16_t depth;
struct ext4_extent_header *header;
struct ext4_extent_index *index;
struct ext4_extent *extent;
};
#define EXT4_EXT_UNWRITTEN_MASK (1L << 15)
#define EXT4_EXT_MAX_LEN_WRITTEN (1L << 15)
#define EXT4_EXT_MAX_LEN_UNWRITTEN \
(EXT4_EXT_MAX_LEN_WRITTEN - 1)
#define EXT4_EXT_GET_LEN(ex) to_le16((ex)->nblocks)
#define EXT4_EXT_GET_LEN_UNWRITTEN(ex) \
(EXT4_EXT_GET_LEN(ex) &= ~(EXT4_EXT_UNWRITTEN_MASK))
#define EXT4_EXT_SET_LEN(ex, count) \
((ex)->nblocks = to_le16(count))
#define EXT4_EXT_IS_UNWRITTEN(ex) \
(EXT4_EXT_GET_LEN(ex) > EXT4_EXT_MAX_LEN_WRITTEN)
#define EXT4_EXT_SET_UNWRITTEN(ex) \
((ex)->nblocks |= to_le16(EXT4_EXT_UNWRITTEN_MASK))
#define EXT4_EXT_SET_WRITTEN(ex) \
((ex)->nblocks &= ~(to_le16(EXT4_EXT_UNWRITTEN_MASK)))
#define EXT4_EXTENT_FIRST(header) \
((struct ext4_extent *)(((char *)(header)) + \
sizeof(struct ext4_extent_header)))
#define EXT4_EXTENT_FIRST_INDEX(header) \
((struct ext4_extent_index *)(((char *)(header)) + \
sizeof(struct ext4_extent_header)))
#define EXT4_EXTENT_LAST(header) \
((struct ext4_extent *)(((char *)(header)) + \
sizeof(struct ext4_extent_header)) + \
(header)->nentries - 1)
#define EXT4_EXTENT_LAST_INDEX(header) \
((struct ext4_extent_index *)(((char *)(header)) + \
sizeof(struct ext4_extent_header)) + \
(header)->nentries - 1)
#define EXT4_EXTENT_SIZE sizeof(struct ext4_extent)
#define EXT4_EXTENT_INDEX_SIZE sizeof(struct ext4_extent_index)
#define EXT4_EXTENT_TAIL_OFFSET(hdr) \
(sizeof(struct ext4_extent_header) + \
(sizeof(struct ext4_extent) * to_le16((hdr)->max_nentries)))
#define EXT4_EXTENT_IN_RANGE(iblock, eiblock, len) \
((iblock) >= (eiblock) && (iblock) <= (eiblock) + (len) - 1)
#define EXT4_EXTENT_MAX_BLOCKS ((uint32_t)(-1))
/**@brief Get logical number of the block covered by extent.
* @param extent Extent to load number from
* @return Logical number of the first block covered by extent */
static inline uint32_t ext4_extent_get_iblock(struct ext4_extent *extent)
{
return to_le32(extent->iblock);
}
/**@brief Set logical number of the first block covered by extent.
* @param extent Extent to set number to
* @param iblock Logical number of the first block covered by extent */
static inline void ext4_extent_set_iblock(struct ext4_extent *extent,
ext4_lblk_t iblock)
{
extent->iblock = to_le32(iblock);
}
/**@brief Get number of blocks covered by extent.
* @param extent Extent to load count from
* @return Number of blocks covered by extent */
static inline uint16_t ext4_extent_get_nblocks(struct ext4_extent *extent)
{
if (EXT4_EXT_IS_UNWRITTEN(extent))
return EXT4_EXT_GET_LEN_UNWRITTEN(extent);
else
return EXT4_EXT_GET_LEN(extent);
}
/**@brief Set number of blocks covered by extent.
* @param extent Extent to load count from
* @param count Number of blocks covered by extent
* @param unwritten Whether the extent is unwritten or not */
static inline void
ext4_extent_set_nblocks(struct ext4_extent *extent,
uint16_t count, bool unwritten)
{
EXT4_EXT_SET_LEN(extent, count);
if (unwritten)
EXT4_EXT_SET_UNWRITTEN(extent);
}
/**@brief Get physical number of the first block covered by extent.
* @param extent Extent to load number
* @return Physical number of the first block covered by extent */
static inline uint64_t ext4_extent_get_fblock(struct ext4_extent *extent)
{
return ((uint64_t)to_le16(extent->fblock_hi)) << 32 |
((uint64_t)to_le32(extent->fblock_lo));
}
/**@brief Set physical number of the first block covered by extent.
* @param extent Extent to load number
* @param fblock Physical number of the first block covered by extent */
static inline void
ext4_extent_set_fblock(struct ext4_extent *extent, uint64_t fblock)
{
extent->fblock_lo = to_le32((fblock << 32) >> 32);
extent->fblock_hi = to_le16((uint16_t)(fblock >> 32));
}
/**@brief Get logical number of the block covered by extent index.
* @param index Extent index to load number from
* @return Logical number of the first block covered by extent index */
static inline uint32_t
ext4_extent_index_get_iblock(struct ext4_extent_index *index)
{
return to_le32(index->iblock);
}
/**@brief Set logical number of the block covered by extent index.
* @param index Extent index to set number to
* @param iblock Logical number of the first block covered by extent index */
static inline void
ext4_extent_index_set_iblock(struct ext4_extent_index *index,
uint32_t iblock)
{
index->iblock = to_le32(iblock);
}
/**@brief Get physical number of block where the child node is located.
* @param index Extent index to load number from
* @return Physical number of the block with child node */
static inline uint64_t
ext4_extent_index_get_fblock(struct ext4_extent_index *index)
{
return ((uint64_t)to_le16(index->fblock_hi)) << 32 |
((uint64_t)to_le32(index->fblock_lo));
}
/**@brief Set physical number of block where the child node is located.
* @param index Extent index to set number to
* @param fblock Ohysical number of the block with child node */
static inline void ext4_extent_index_set_fblock(struct ext4_extent_index *index,
uint64_t fblock)
{
index->fblock_lo = to_le32((fblock << 32) >> 32);
index->fblock_hi = to_le16((uint16_t)(fblock >> 32));
}
/**@brief Get magic value from extent header.
* @param header Extent header to load value from
* @return Magic value of extent header */
static inline uint16_t
ext4_extent_header_get_magic(struct ext4_extent_header *header)
{
return to_le16(header->magic);
}
/**@brief Set magic value to extent header.
* @param header Extent header to set value to
* @param magic Magic value of extent header */
static inline void ext4_extent_header_set_magic(struct ext4_extent_header *header,
uint16_t magic)
{
header->magic = to_le16(magic);
}
/**@brief Get number of entries from extent header
* @param header Extent header to get value from
* @return Number of entries covered by extent header */
static inline uint16_t
ext4_extent_header_get_nentries(struct ext4_extent_header *header)
{
return to_le16(header->nentries);
}
/**@brief Set number of entries to extent header
* @param header Extent header to set value to
* @param count Number of entries covered by extent header */
static inline void
ext4_extent_header_set_nentries(struct ext4_extent_header *header,
uint16_t count)
{
header->nentries = to_le16(count);
}
/**@brief Get maximum number of entries from extent header
* @param header Extent header to get value from
* @return Maximum number of entries covered by extent header */
static inline uint16_t
ext4_extent_header_get_max_nentries(struct ext4_extent_header *header)
{
return to_le16(header->max_nentries);
}
/**@brief Set maximum number of entries to extent header
* @param header Extent header to set value to
* @param max_count Maximum number of entries covered by extent header */
static inline void
ext4_extent_header_set_max_nentries(struct ext4_extent_header *header,
uint16_t max_count)
{
header->max_nentries = to_le16(max_count);
}
/**@brief Get depth of extent subtree.
* @param header Extent header to get value from
* @return Depth of extent subtree */
static inline uint16_t
ext4_extent_header_get_depth(struct ext4_extent_header *header)
{
return to_le16(header->depth);
}
/**@brief Set depth of extent subtree.
* @param header Extent header to set value to
* @param depth Depth of extent subtree */
static inline void
ext4_extent_header_set_depth(struct ext4_extent_header *header,
uint16_t depth)
{
header->depth = to_le16(depth);
}
/**@brief Get generation from extent header
* @param header Extent header to get value from
* @return Generation */
static inline uint32_t
ext4_extent_header_get_generation(struct ext4_extent_header *header)
{
return to_le32(header->generation);
}
/**@brief Set generation to extent header
* @param header Extent header to set value to
* @param generation Generation */
static inline void
ext4_extent_header_set_generation(struct ext4_extent_header *header,
uint32_t generation)
{
header->generation = to_le32(generation);
}
/******************************************************************************/
/**TODO: */
static inline void ext4_extent_tree_init(struct ext4_inode_ref *inode_ref)
{
/* Initialize extent root header */
struct ext4_extent_header *header =
ext4_inode_get_extent_header(inode_ref->inode);
ext4_extent_header_set_depth(header, 0);
ext4_extent_header_set_nentries(header, 0);
ext4_extent_header_set_generation(header, 0);
ext4_extent_header_set_magic(header, EXT4_EXTENT_MAGIC);
uint16_t max_entries = (EXT4_INODE_BLOCKS * sizeof(uint32_t) -
sizeof(struct ext4_extent_header)) /
sizeof(struct ext4_extent);
ext4_extent_header_set_max_nentries(header, max_entries);
inode_ref->dirty = true;
}
/**@brief Extent-based blockmap manipulation
* @param inode_ref I-node
* @param iblock starting logical block of the inode
* @param max_nblocks maximum number of blocks to get from/allocate to blockmap
* @param resfblockp return physical block address of the first block of an
* extent
* @param create true if caller wants to insert mapping or convert
* unwritten mapping to written one
* @param resnblocksp return number of blocks in an extent (must be smaller than
* \p max_nblocks)
* @return Error code*/
int ext4_extent_get_blocks(struct ext4_inode_ref *inode_ref,
ext4_lblk_t iblock,
ext4_lblk_t max_nblocks,
ext4_fsblk_t *resfblockp,
bool create,
ext4_lblk_t *resnblocksp);
/**@brief Release all data blocks starting from specified logical block.
* @param inode_ref I-node to release blocks from
* @param iblock_from First logical block to release
* @return Error code */
int ext4_extent_remove_space(struct ext4_inode_ref *inode_ref,
ext4_lblk_t from,
ext4_lblk_t to);
#ifdef __cplusplus
}
#endif
#endif /* EXT4_EXTENT_H_ */
/**
* @}
*/