btrfs-progs/libbtrfsutil/btrfsutil_internal.h
David Sterba 9a01491042 libbtrfsutil: add internal helpers for unaligned access
We will need generic helpers for unaligned access with LE->CPU
conversion, so add them. Should be use for potentially unaligned read
from tree search buffer.

Signed-off-by: David Sterba <dsterba@suse.com>
2024-05-29 21:27:07 +02:00

105 lines
2.8 KiB
C

/*
* Copyright (C) 2018 Facebook
*
* This file is part of libbtrfsutil.
*
* libbtrfsutil is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 2.1 of the License, or
* (at your option) any later version.
*
* libbtrfsutil is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with libbtrfsutil. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef BTRFS_UTIL_INTERNAL_H
#define BTRFS_UTIL_INTERNAL_H
#include <asm/byteorder.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include "btrfsutil.h"
#include "btrfs.h"
#include "btrfs_tree.h"
#define PUBLIC __attribute__((visibility("default")))
#define LIBBTRFSUTIL_ALIAS(orig) __attribute__((alias(#orig)))
#define le16_to_cpu __le16_to_cpu
#define le32_to_cpu __le32_to_cpu
#define le64_to_cpu __le64_to_cpu
#define SAVE_ERRNO_AND_CLOSE(fd) do { \
int saved_errno = errno; \
\
close(fd); \
errno = saved_errno; \
} while (0)
struct __unagligned_u16 { __le16 x; } __attribute__((__packed__));
struct __unagligned_u32 { __le32 x; } __attribute__((__packed__));
struct __unagligned_u64 { __le64 x; } __attribute__((__packed__));
static inline __u16 get_unaligned_le16(const void *ptr)
{
return le16_to_cpu(((const struct __unagligned_u16 *)(ptr))->x);
}
static inline __u32 get_unaligned_le32(const void *ptr)
{
return le32_to_cpu(((const struct __unagligned_u32 *)(ptr))->x);
}
static inline __u64 get_unaligned_le64(const void *ptr)
{
return le64_to_cpu(((const struct __unagligned_u64 *)(ptr))->x);
}
/*
* Accessors of search header that is commonly mapped to a byte buffer so the
* alignment is not guraranteed
*/
static inline __u64 btrfs_search_header_transid(const struct btrfs_ioctl_search_header *sh)
{
__u64 tmp;
memcpy(&tmp, &sh->transid, sizeof(__u64));
return tmp;
}
static inline __u64 btrfs_search_header_objectid(const struct btrfs_ioctl_search_header *sh)
{
__u64 tmp;
memcpy(&tmp, &sh->objectid, sizeof(__u64));
return tmp;
}
static inline __u64 btrfs_search_header_offset(const struct btrfs_ioctl_search_header *sh)
{
__u64 tmp;
memcpy(&tmp, &sh->offset, sizeof(__u64));
return tmp;
}
static inline __u32 btrfs_search_header_type(const struct btrfs_ioctl_search_header *sh)
{
__u32 tmp;
memcpy(&tmp, &sh->type, sizeof(__u32));
return tmp;
}
static inline __u32 btrfs_search_header_len(const struct btrfs_ioctl_search_header *sh)
{
__u32 tmp;
memcpy(&tmp, &sh->len, sizeof(__u32));
return tmp;
}
#endif /* BTRFS_UTIL_INTERNAL_H */