path: root/fs/btrfs/accessors.h

/* SPDX-License-Identifier: GPL-2.0 */

#ifndef BTRFS_ACCESSORS_H
#define BTRFS_ACCESSORS_H

#include <linux/unaligned.h>
#include <linux/stddef.h>
#include <linux/types.h>
#include <linux/align.h>
#include <linux/build_bug.h>
#include <linux/compiler.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <uapi/linux/btrfs_tree.h>
#include "fs.h"
#include "extent_io.h"

struct extent_buffer;

/*
 * Some macros to generate set/get functions for the struct fields.  This
 * assumes there is a lefoo_to_cpu for every type, so lets make a simple one
 * for u8:
 */
#define le8_to_cpu(v) (v)
#define cpu_to_le8(v) (v)
#define __le8 u8

static inline u8 get_unaligned_le8(const void *p)
{
       return *(const u8 *)p;
}

static inline void put_unaligned_le8(u8 val, void *p)
{
       *(u8 *)p = val;
}

#define read_eb_member(eb, ptr, type, member, result) (\
	read_extent_buffer(eb, (char *)(result),			\
			   ((unsigned long)(ptr)) +			\
			    offsetof(type, member),			\
			    sizeof_field(type, member)))

#define write_eb_member(eb, ptr, type, member, source) (		\
	write_extent_buffer(eb, (const char *)(source),			\
			   ((unsigned long)(ptr)) +			\
			    offsetof(type, member),			\
			    sizeof_field(type, member)))

#define DECLARE_BTRFS_SETGET_BITS(bits)					\
u##bits btrfs_get_##bits(const struct extent_buffer *eb,		\
			 const void *ptr, unsigned long off);		\
void btrfs_set_##bits(const struct extent_buffer *eb, void *ptr,	\
		      unsigned long off, u##bits val);

DECLARE_BTRFS_SETGET_BITS(8)
DECLARE_BTRFS_SETGET_BITS(16)
DECLARE_BTRFS_SETGET_BITS(32)
DECLARE_BTRFS_SETGET_BITS(64)

#define BTRFS_SETGET_FUNCS(name, type, member, bits)			\
static inline u##bits btrfs_##name(const struct extent_buffer *eb,	\
				   const type *s)			\
{									\
	static_assert(sizeof(u##bits) == sizeof_field(type, member));	\
	return btrfs_get_##bits(eb, s, offsetof(type, member));		\
}									\
static inline void btrfs_set_##name(const struct extent_buffer *eb, type *s, \
				    u##bits val)			\
{									\
	static_assert(sizeof(u##bits) == sizeof_field(type, member));	\
	btrfs_set_##bits(eb, s, offsetof(type, member), val);		\
}

#define BTRFS_SETGET_HEADER_FUNCS(name, type, member, bits)		\
static inline u##bits btrfs_##name(const struct extent_buffer *eb)	\
{									\
	const type *p = folio_address(eb->folios[0]) +			\
			offset_in_page(eb->start);			\
	return get_unaligned_le##bits(&p->member);			\
}									\
static inline void btrfs_set_##name(const struct extent_buffer *eb,	\
				    u##bits val)			\
{									\
	type *p = folio_address(eb->folios[0]) + offset_in_page(eb->start); \
	put_unaligned_le##bits(val, &p->member);			\
}

#define BTRFS_SETGET_STACK_FUNCS(name, type, member, bits)		\
static inline u##bits btrfs_##name(const type *s)			\
{									\
	return get_unaligned_le##bits(&s->member);			\
}									\
static inline void btrfs_set_##name(type *s, u##bits val)		\
{									\
	put_unaligned_le##bits(val, &s->member);			\
}

static inline u64 btrfs_device_total_bytes(const struct extent_buffer *eb,
					   struct btrfs_dev_item *s)
{
	static_assert(sizeof(u64) == sizeof_field(struct btrfs_dev_item, total_bytes));
	return btrfs_get_64(eb, s, offsetof(struct btrfs_dev_item, total_bytes));
}
static inline void btrfs_set_device_total_bytes(const struct extent_buffer *eb,
						struct btrfs_dev_item *s,
						u64 val)
{
	static_assert(sizeof(u64) == sizeof_field(struct btrfs_dev_item, total_bytes));
	WARN_ON(!IS_ALIGNED(val, eb->fs_info->sectorsize));
	btrfs_set_64(eb, s, offsetof(struct btrfs_dev_item, total_bytes), val);
}

BTRFS_SETGET_FUNCS(device_type, struct btrfs_dev_item, type, 64);
BTRFS_SETGET_FUNCS(device_bytes_used, struct btrfs_dev_item, bytes_used, 64);
BTRFS_SETGET_FUNCS(device_io_align, struct btrfs_dev_item, io_align, 32);
BTRFS_SETGET_FUNCS(device_io_width, struct btrfs_dev_item, io_width, 32);
BTRFS_SETGET_FUNCS(device_start_offset, struct btrfs_dev_item, start_offset, 64);
BTRFS_SETGET_FUNCS(device_sector_size, struct btrfs_dev_item, sector_size, 32);
BTRFS_SETGET_FUNCS(device_id, struct btrfs_dev_item, devid, 64);
BTRFS_SETGET_FUNCS(device_group, struct btrfs_dev_item, dev_group, 32);
BTRFS_SETGET_FUNCS(device_seek_speed, struct btrfs_dev_item, seek_speed, 8);
BTRFS_SETGET_FUNCS(device_bandwidth, struct btrfs_dev_item, bandwidth, 8);
BTRFS_SETGET_FUNCS(device_generation, struct btrfs_dev_item, generation, 64);

BTRFS_SETGET_STACK_FUNCS(stack_device_type, struct btrfs_dev_item, type, 64);
BTRFS_SETGET_STACK_FUNCS(stack_device_total_bytes, struct btrfs_dev_item,
			 total_bytes, 64);
BTRFS_SETGET_STACK_FUNCS(stack_device_bytes_used, struct btrfs_dev_item,
			 bytes_used, 64);
BTRFS_SETGET_STACK_FUNCS(stack_device_io_align, struct btrfs_dev_item,
			 io_align, 32);
BTRFS_SETGET_STACK_FUNCS(stack_device_io_width, struct btrfs_dev_item,
			 io_width, 32);
BTRFS_SETGET_STACK_FUNCS(stack_device_sector_size, struct btrfs_dev_item,
			 sector_size, 32);
BTRFS_SETGET_STACK_FUNCS(stack_device_id, struct btrfs_dev_item, devid, 64);
BTRFS_SETGET_STACK_FUNCS(stack_device_group, struct btrfs_dev_item, dev_group, 32);
BTRFS_SETGET_STACK_FUNCS(stack_device_seek_speed, struct btrfs_dev_item,
			 seek_speed, 8);
BTRFS_SETGET_STACK_FUNCS(stack_device_bandwidth, struct btrfs_dev_item,
			 bandwidth, 8);
BTRFS_SETGET_STACK_FUNCS(stack_device_generation, struct btrfs_dev_item,
			 generation,