ref: a3f2d6d23ed1be69fee607bdedadc0438fd01305
dir: /sys/src/cmd/ext4srv/include/ext4_extent.h/
#pragma once
#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;
u16int 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 ((u32int)(-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 u32int 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 u16int 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,
u16int 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 u64int ext4_extent_get_fblock(struct ext4_extent *extent)
{
return ((u64int)to_le16(extent->fblock_hi)) << 32 |
((u64int)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, u64int fblock)
{
extent->fblock_lo = to_le32((fblock << 32) >> 32);
extent->fblock_hi = to_le16((u16int)(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 u32int
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,
u32int 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 u64int
ext4_extent_index_get_fblock(struct ext4_extent_index *index)
{
return ((u64int)to_le16(index->fblock_hi)) << 32 |
((u64int)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,
u64int fblock)
{
index->fblock_lo = to_le32((fblock << 32) >> 32);
index->fblock_hi = to_le16((u16int)(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 u16int
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,
u16int 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 u16int
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,
u16int 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 u16int
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,
u16int 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 u16int
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,
u16int depth)
{
header->depth = to_le16(depth);
}
/**@brief Get generation from extent header
* @param header Extent header to get value from
* @return Generation */
static inline u32int
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,
u32int 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);
u16int max_entries = (EXT4_INODE_BLOCKS * sizeof(u32int) -
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);