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// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2007 Oracle. All rights reserved.
*/
#include <asm/unaligned.h>
#include "messages.h"
#include "ctree.h"
#include "accessors.h"
static bool check_setget_bounds(const struct extent_buffer *eb,
const void *ptr, unsigned off, int size)
{
const unsigned long member_offset = (unsigned long)ptr + off;
if (unlikely(member_offset + size > eb->len)) {
btrfs_warn(eb->fs_info,
"bad eb member %s: ptr 0x%lx start %llu member offset %lu size %d",
(member_offset > eb->len ? "start" : "end"),
(unsigned long)ptr, eb->start, member_offset, size);
return false;
}
return true;
}
void btrfs_init_map_token(struct btrfs_map_token *token, struct extent_buffer *eb)
{
token->eb = eb;
token->kaddr = folio_address(eb->folios[0]);
token->offset = 0;
}
/*
* Macro templates that define helpers to read/write extent buffer data of a
* given size, that are also used via ctree.h for access to item members by
* specialized helpers.
*
* Generic helpers:
* - btrfs_set_8 (for 8/16/32/64)
* - btrfs_get_8 (for 8/16/32/64)
*
* Generic helpers with a token (cached address of the most recently accessed
* page):
* - btrfs_set_token_8 (for 8/16/32/64)
* - btrfs_get_token_8 (for 8/16/32/64)
*
* The set/get functions handle data spanning two pages transparently, in case
* metadata block size is larger than page. Every pointer to metadata items is
* an offset into the extent buffer page array, cast to a specific type. This
* gives us all the type checking.
*
* The extent buffer pages stored in the array folios may not form a contiguous
* phyusical range, but the API functions assume the linear offset to the range
* from 0 to metadata node size.
*/
#define DEFINE_BTRFS_SETGET_BITS(bits) \
u##bits btrfs_get_token_##bits(struct btrfs_map_token *token, \
const void *ptr, unsigned long off) \
{ \
const unsigned long member_offset = (unsigned long)ptr + off; \
const unsigned long idx = get_eb_folio_index(token->eb, member_offset); \
const unsigned long oil = get_eb_offset_in_folio(token->eb, \
member_offset);\
const int unit_size = folio_size(token->eb->folios[0]); \
const int unit_shift = folio_shift(token->eb->folios[0]); \
const int size = sizeof(u##bits); \
u8 lebytes[sizeof(u##bits)]; \
const int part = unit_size - oil; \
\
ASSERT(token); \
ASSERT(token->kaddr); \
ASSERT(check_setget_bounds(token->eb, ptr, off, size)); \
if (token->offset <= member_offset && \
member_offset + size <= token->offset + unit_size) { \
return get_unaligned_le##bits(token->kaddr + oil); \
} \
token->kaddr = folio_address(token->eb->folios[idx]); \
token->offset = idx << unit_shift; \
if (INLINE_EXTENT_BUFFER_PAGES == 1 || oil + size <= unit_size) \
return get_unaligned_le##bits(token->kaddr + oil); \
\
memcpy(lebytes, token->kaddr + oil, part); \
token->kaddr = folio_address(token->eb->folios[idx + 1]); \
token->offset = (idx + 1) << unit_shift; \
memcpy(lebytes + part, token->kaddr, size - part); \
return get_unaligned_le##bits(lebytes); \
} \
u##bits btrfs_get_##bits(const struct extent_buffer *eb, \
const void *ptr, unsigned long off) \
{ \
const unsigned long member_offset = (unsigned long)ptr + off; \
const unsigned long idx = get_eb_folio_index(eb, member_offset);\
const unsigned long oil = get_eb_offset_in_folio(eb, \
member_offset);\
const int unit_size = folio_size(eb->folios[0]); \
char *kaddr = folio_address(eb->folios[idx]); \
const int size = sizeof(u##bits); \
const int part = unit_size - oil; \
u8 lebytes[sizeof(u##bits)]; \
\
ASSERT(check_setget_bounds(eb, ptr, off, size)); \
if (INLINE_EXTENT_BUFFER_PAGES == 1 || oil + size <= unit_size) \
return get_unaligned_le##bits(kaddr + oil); \
\
memcpy(lebytes, kaddr + oil, part); \
kaddr = folio_address(eb->folios[idx + 1]); \
memcpy(lebytes + part, kaddr, size - part); \
return get_unaligned_le##bits(lebytes); \
} \
void btrfs_set_token_##bits(struct btrfs_map_token *token, \
const void *ptr, unsigned long off, \
u##bits val) \
{ \
const unsigned long member_offset = (unsigned long)ptr + off; \
const unsigned long idx = get_eb_folio_index(token->eb, member_offset); \
const unsigned long oil = get_eb_offset_in_folio(token->eb, \
member_offset);\
const int unit_size = folio_size(token->eb->folios[0]); \
const int unit_shift = folio_shift(token->eb->folios[0]); \
const int size = sizeof(u##bits); \
u8 lebytes[sizeof(u##bits)]; \
const int part = unit_size - oil; \
\
ASSERT(token); \
ASSERT(token->kaddr); \
ASSERT(check_setget_bounds(token->eb, ptr, off, size)); \
if (token->offset <= member_offset && \
member_offset + size <= token->offset + unit_size) { \
put_unaligned_le##bits(val, token->kaddr + oil); \
return; \
} \
token->kaddr = folio_address(token->eb->folios[idx]); \
token->offset = idx << unit_shift; \
if (INLINE_EXTENT_BUFFER_PAGES == 1 || \
oil + size <= unit_size) { \
put_unaligned_le##bits(val, token->kaddr + oil); \
return; \
} \
put_unaligned_le##bits(val, lebytes); \
memcpy(token->kaddr + oil, lebytes, part); \
token->kaddr = folio_address(token->eb->folios[idx + 1]); \
token->offset = (idx + 1) << unit_shift; \
memcpy(token->kaddr, lebytes + part, size - part); \
} \
void btrfs_set_##bits(const struct extent_buffer *eb, void *ptr, \
unsigned long off, u##bits val) \
{ \
const unsigned long member_offset = (unsigned long)ptr + off; \
const unsigned long idx = get_eb_folio_index(eb, member_offset);\
const unsigned long oil = get_eb_offset_in_folio(eb, \
member_offset);\
const int unit_size = folio_size(eb->folios[0]); \
char *kaddr = folio_address(eb->folios[idx]); \
const int size = sizeof(u##bits); \
const int part = unit_size - oil; \
u8 lebytes[sizeof(u##bits)]; \
\
ASSERT(check_setget_bounds(eb, ptr, off, size)); \
if (INLINE_EXTENT_BUFFER_PAGES == 1 || \
oil + size <= unit_size) { \
put_unaligned_le##bits(val, kaddr + oil); \
return; \
} \
\
put_unaligned_le##bits(val, lebytes); \
memcpy(kaddr + oil, lebytes, part); \
kaddr = folio_address(eb->folios[idx + 1]); \
memcpy(kaddr, lebytes + part, size - part); \
}
DEFINE_BTRFS_SETGET_BITS(8)
DEFINE_BTRFS_SETGET_BITS(16)
DEFINE_BTRFS_SETGET_BITS(32)
DEFINE_BTRFS_SETGET_BITS(64)
void btrfs_node_key(const struct extent_buffer *eb,
struct btrfs_disk_key *disk_key, int nr)
{
unsigned long ptr = btrfs_node_key_ptr_offset(eb, nr);
read_eb_member(eb, (struct btrfs_key_ptr *)ptr,
struct btrfs_key_ptr, key, disk_key);
}
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