Commit e97659ce authored by David Sterba's avatar David Sterba
Browse files

btrfs: use unaligned helpers for stack and header set/get helpers 



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: default avatarDavid Sterba <dsterba@suse.com>
parent 6994ca36

fs/btrfs/ctree.h

+14 −6
Original line number Diff line number Diff line
@@ -1420,6 +1420,16 @@ static inline void btrfs_init_map_token(struct btrfs_map_token *token, 
#define cpu_to_le8(v) (v)

#define __le8 u8



static inline u8 get_unaligned_le8(const void *p)

{

       return *(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)) +			\
@@ -1478,27 +1488,25 @@ static inline void btrfs_set_token_##name(struct btrfs_map_token *token,\ 
static inline u##bits btrfs_##name(const struct extent_buffer *eb)	\

{									\

	const type *p = page_address(eb->pages[0]);			\

	u##bits res = le##bits##_to_cpu(p->member);			\

	return res;							\

	return get_unaligned_le##bits(&p->member);			\

}									\

static inline void btrfs_set_##name(const struct extent_buffer *eb,	\

				    u##bits val)			\

{									\

	type *p = page_address(eb->pages[0]);				\

	p->member = cpu_to_le##bits(val);				\

	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 le##bits##_to_cpu(s->member);				\

	return get_unaligned_le##bits(&s->member);			\

}									\

static inline void btrfs_set_##name(type *s, u##bits val)		\

{									\

	s->member = cpu_to_le##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)

{

fs/btrfs/struct-funcs.c

+0 −10
Original line number Diff line number Diff line
@@ -7,16 +7,6 @@ 


#include "ctree.h"



static inline u8 get_unaligned_le8(const void *p)

{

       return *(u8 *)p;

}



static inline void put_unaligned_le8(u8 val, void *p)

{

       *(u8 *)p = val;

}



static bool check_setget_bounds(const struct extent_buffer *eb,

				const void *ptr, unsigned off, int size)

{

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