mirror of
https://github.com/torvalds/linux.git
synced 2025-11-04 02:30:34 +02:00
e97659cefe
In the definitions generated by BTRFS_SETGET_HEADER_FUNCS there's direct pointer assignment but we should use the helpers for unaligned access for clarity. It hasn't been a problem so far because of the natural alignment. Similarly for BTRFS_SETGET_STACK_FUNCS, that usually get a structure from stack that has an aligned start but some members may not be aligned due to packing. This as well hasn't caused problems so far. Move the put/get_unaligned_le8 stubs to ctree.h so we can use them. Signed-off-by: David Sterba <dsterba@suse.com>
169 lines
6 KiB
C
169 lines
6 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* Copyright (C) 2007 Oracle. All rights reserved.
|
|
*/
|
|
|
|
#include <asm/unaligned.h>
|
|
|
|
#include "ctree.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 (member_offset > eb->len) {
|
|
btrfs_warn(eb->fs_info,
|
|
"bad eb member start: ptr 0x%lx start %llu member offset %lu size %d",
|
|
(unsigned long)ptr, eb->start, member_offset, size);
|
|
return false;
|
|
}
|
|
if (member_offset + size > eb->len) {
|
|
btrfs_warn(eb->fs_info,
|
|
"bad eb member end: ptr 0x%lx start %llu member offset %lu size %d",
|
|
(unsigned long)ptr, eb->start, member_offset, size);
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
/*
|
|
* 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 pages do 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 = member_offset >> PAGE_SHIFT; \
|
|
const unsigned long oip = offset_in_page(member_offset); \
|
|
const int size = sizeof(u##bits); \
|
|
u8 lebytes[sizeof(u##bits)]; \
|
|
const int part = PAGE_SIZE - oip; \
|
|
\
|
|
ASSERT(token); \
|
|
ASSERT(token->kaddr); \
|
|
ASSERT(check_setget_bounds(token->eb, ptr, off, size)); \
|
|
if (token->offset <= member_offset && \
|
|
member_offset + size <= token->offset + PAGE_SIZE) { \
|
|
return get_unaligned_le##bits(token->kaddr + oip); \
|
|
} \
|
|
token->kaddr = page_address(token->eb->pages[idx]); \
|
|
token->offset = idx << PAGE_SHIFT; \
|
|
if (oip + size <= PAGE_SIZE) \
|
|
return get_unaligned_le##bits(token->kaddr + oip); \
|
|
\
|
|
memcpy(lebytes, token->kaddr + oip, part); \
|
|
token->kaddr = page_address(token->eb->pages[idx + 1]); \
|
|
token->offset = (idx + 1) << PAGE_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 oip = offset_in_page(member_offset); \
|
|
const unsigned long idx = member_offset >> PAGE_SHIFT; \
|
|
char *kaddr = page_address(eb->pages[idx]); \
|
|
const int size = sizeof(u##bits); \
|
|
const int part = PAGE_SIZE - oip; \
|
|
u8 lebytes[sizeof(u##bits)]; \
|
|
\
|
|
ASSERT(check_setget_bounds(eb, ptr, off, size)); \
|
|
if (oip + size <= PAGE_SIZE) \
|
|
return get_unaligned_le##bits(kaddr + oip); \
|
|
\
|
|
memcpy(lebytes, kaddr + oip, part); \
|
|
kaddr = page_address(eb->pages[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 = member_offset >> PAGE_SHIFT; \
|
|
const unsigned long oip = offset_in_page(member_offset); \
|
|
const int size = sizeof(u##bits); \
|
|
u8 lebytes[sizeof(u##bits)]; \
|
|
const int part = PAGE_SIZE - oip; \
|
|
\
|
|
ASSERT(token); \
|
|
ASSERT(token->kaddr); \
|
|
ASSERT(check_setget_bounds(token->eb, ptr, off, size)); \
|
|
if (token->offset <= member_offset && \
|
|
member_offset + size <= token->offset + PAGE_SIZE) { \
|
|
put_unaligned_le##bits(val, token->kaddr + oip); \
|
|
return; \
|
|
} \
|
|
token->kaddr = page_address(token->eb->pages[idx]); \
|
|
token->offset = idx << PAGE_SHIFT; \
|
|
if (oip + size <= PAGE_SIZE) { \
|
|
put_unaligned_le##bits(val, token->kaddr + oip); \
|
|
return; \
|
|
} \
|
|
put_unaligned_le##bits(val, lebytes); \
|
|
memcpy(token->kaddr + oip, lebytes, part); \
|
|
token->kaddr = page_address(token->eb->pages[idx + 1]); \
|
|
token->offset = (idx + 1) << PAGE_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 oip = offset_in_page(member_offset); \
|
|
const unsigned long idx = member_offset >> PAGE_SHIFT; \
|
|
char *kaddr = page_address(eb->pages[idx]); \
|
|
const int size = sizeof(u##bits); \
|
|
const int part = PAGE_SIZE - oip; \
|
|
u8 lebytes[sizeof(u##bits)]; \
|
|
\
|
|
ASSERT(check_setget_bounds(eb, ptr, off, size)); \
|
|
if (oip + size <= PAGE_SIZE) { \
|
|
put_unaligned_le##bits(val, kaddr + oip); \
|
|
return; \
|
|
} \
|
|
\
|
|
put_unaligned_le##bits(val, lebytes); \
|
|
memcpy(kaddr + oip, lebytes, part); \
|
|
kaddr = page_address(eb->pages[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(nr);
|
|
read_eb_member(eb, (struct btrfs_key_ptr *)ptr,
|
|
struct btrfs_key_ptr, key, disk_key);
|
|
}
|