btrfs-progs/kernel-shared/accessors.c
Josef Bacik c979ffd787 btrfs-progs: sync accessors.[ch] from the kernel
This syncs accessors.[ch] from the kernel.  For the most part
accessors.h will remain the same, there's just some helpers that need to
be adjusted for eb->data instead of eb->pages.  Additionally accessors.c
needed to be completely updated to deal with this as well.

This is a set of files where we will likely only sync the header going
forward, and leave the C file in place as it needs to be specific to
btrfs-progs.

This forced a few "unrelated" changes

- Using btrfs_dir_item_ftype() instead of btrfs_dir_item_type().  This
  is due to the encryption changes, and was simpler to just do in this
  patch.
- Adjusting some of the print tree code to use the actual helpers and
  not the btrfs-progs ones.

A local definition of static_assert is used to avoid compilation
failures on older gcc (< 9) where the 2nd parameter is mandatory.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2023-05-26 18:02:28 +02:00

118 lines
3.8 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2007 Oracle. All rights reserved.
*/
#include "kerncompat.h"
#include "kernel-shared/messages.h"
#include "kernel-shared/ctree.h"
#include "kernel-shared/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;
}
/*
* MODIFIED:
* - We don't have eb->pages.
*/
void btrfs_init_map_token(struct btrfs_map_token *token, struct extent_buffer *eb)
{
token->eb = eb;
token->kaddr = eb->data;
token->offset = 0;
}
/*
* MODIFIED:
* - We don't have eb->pages, simply wrap the set/get helpers.
*/
/*
* 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 int size = sizeof(u##bits); \
ASSERT(token); \
ASSERT(token->kaddr); \
ASSERT(check_setget_bounds(token->eb, ptr, off, size)); \
return get_unaligned_le##bits(token->kaddr + member_offset); \
} \
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 int size = sizeof(u##bits); \
ASSERT(check_setget_bounds(eb, ptr, off, size)); \
return get_unaligned_le##bits(eb->data + member_offset); \
} \
void btrfs_set_token_##bits(struct btrfs_map_token *token, \
const void *ptr, unsigned long off, \
u##bits val) \
{ \
unsigned long member_offset = (unsigned long)ptr + off; \
const int size = sizeof(u##bits); \
ASSERT(token); \
ASSERT(token->kaddr); \
ASSERT(check_setget_bounds(token->eb, ptr, off, size)); \
put_unaligned_le##bits(val, token->kaddr + member_offset); \
} \
void btrfs_set_##bits(const struct extent_buffer *eb, void *ptr, \
unsigned long off, u##bits val) \
{ \
unsigned long member_offset = (unsigned long)ptr + off; \
const int size = sizeof(u##bits); \
ASSERT(check_setget_bounds(eb, ptr, off, size)); \
put_unaligned_le##bits(val, (void *)eb->data + member_offset); \
}
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);
}