Commit 18077bb4 authored by Li Zefan's avatar Li Zefan Committed by Chris Mason
Browse files

Btrfs: rewrite BTRFS_SETGET_FUNCS 



BTRFS_SETGET_FUNCS macro is used to generate btrfs_set_foo() and
btrfs_foo() functions, which read and write specific fields in the
extent buffer.

The total number of set/get functions is ~200, but in fact we only
need 8 functions: 2 for u8 field, 2 for u16, 2 for u32 and 2 for u64.

It results in redunction of ~37K bytes.

   text    data     bss     dec     hex filename
 629661   12489     216  642366   9cd3e fs/btrfs/btrfs.o.orig
 592637   12489     216  605342   93c9e fs/btrfs/btrfs.o

Signed-off-by: default avatarLi Zefan <lizefan@huawei.com>
parent 293f7e07

fs/btrfs/ctree.h

+47 −6
Original line number Diff line number Diff line
@@ -1623,13 +1623,54 @@ static inline void btrfs_init_map_token (struct btrfs_map_token *token) 
			    offsetof(type, member),			\

			   sizeof(((type *)0)->member)))



#ifndef BTRFS_SETGET_FUNCS

#define DECLARE_BTRFS_SETGET_BITS(bits)					\

u##bits btrfs_get_token_##bits(struct extent_buffer *eb, void *ptr,	\

			       unsigned long off,			\

                              struct btrfs_map_token *token);		\

void btrfs_set_token_##bits(struct extent_buffer *eb, void *ptr,	\

			    unsigned long off, u##bits val,		\

			    struct btrfs_map_token *token);		\

static inline u##bits btrfs_get_##bits(struct extent_buffer *eb, void *ptr, \

				       unsigned long off)		\

{									\

	return btrfs_get_token_##bits(eb, ptr, off, NULL);		\

}									\

static inline void btrfs_set_##bits(struct extent_buffer *eb, void *ptr, \

				    unsigned long off, u##bits val)	\

{									\

       btrfs_set_token_##bits(eb, ptr, off, val, NULL);			\

}



DECLARE_BTRFS_SETGET_BITS(8)

DECLARE_BTRFS_SETGET_BITS(16)

DECLARE_BTRFS_SETGET_BITS(32)

DECLARE_BTRFS_SETGET_BITS(64)



#define BTRFS_SETGET_FUNCS(name, type, member, bits)			\

u##bits btrfs_##name(struct extent_buffer *eb, type *s);		\

u##bits btrfs_token_##name(struct extent_buffer *eb, type *s, struct btrfs_map_token *token);		\

void btrfs_set_token_##name(struct extent_buffer *eb, type *s, u##bits val, struct btrfs_map_token *token);\

void btrfs_set_##name(struct extent_buffer *eb, type *s, u##bits val);

#endif

static inline u##bits btrfs_##name(struct extent_buffer *eb, type *s)	\

{									\

	BUILD_BUG_ON(sizeof(u##bits) != sizeof(((type *)0))->member);	\

	return btrfs_get_##bits(eb, s, offsetof(type, member));		\

}									\

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

				    u##bits val)			\

{									\

	BUILD_BUG_ON(sizeof(u##bits) != sizeof(((type *)0))->member);	\

	btrfs_set_##bits(eb, s, offsetof(type, member), val);		\

}									\

static inline u##bits btrfs_token_##name(struct extent_buffer *eb, type *s, \

					 struct btrfs_map_token *token)	\

{									\

	BUILD_BUG_ON(sizeof(u##bits) != sizeof(((type *)0))->member);	\

	return btrfs_get_token_##bits(eb, s, offsetof(type, member), token); \

}									\

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

					  type *s, u##bits val,		\

                                         struct btrfs_map_token *token)	\

{									\

	BUILD_BUG_ON(sizeof(u##bits) != sizeof(((type *)0))->member);	\

	btrfs_set_token_##bits(eb, s, offsetof(type, member), val, token); \

}



#define BTRFS_SETGET_HEADER_FUNCS(name, type, member, bits)		\

static inline u##bits btrfs_##name(struct extent_buffer *eb)		\

fs/btrfs/struct-funcs.c

+99 −97
Original line number Diff line number Diff line
@@ -17,15 +17,27 @@ 
 */



#include <linux/highmem.h>

#include <asm/unaligned.h>



/* this is some deeply nasty code.  ctree.h has a different

 * definition for this BTRFS_SETGET_FUNCS macro, behind a #ifndef

#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;

}



/*

 * this is some deeply nasty code.

 *

 * The end result is that anyone who #includes ctree.h gets a

 * declaration for the btrfs_set_foo functions and btrfs_foo functions

 *

 * This file declares the macros and then #includes ctree.h, which results

 * in cpp creating the function here based on the template below.

 * declaration for the btrfs_set_foo functions and btrfs_foo functions,

 * which are wappers of btrfs_set_token_#bits functions and

 * btrfs_get_token_#bits functions, which are defined in this file.

 *

 * These setget functions do all the extent_buffer related mapping

 * required to efficiently read and write specific fields in the extent
@@ -33,48 +45,43 @@ 
 * an unsigned long offset into the extent buffer which has been

 * cast to a specific type.  This gives us all the gcc type checking.

 *

 * The extent buffer api is used to do all the kmapping and page

 * spanning work required to get extent buffers in highmem and have

 * a metadata blocksize different from the page size.

 *

 * The macro starts with a simple function prototype declaration so that

 * sparse won't complain about it being static.

 * The extent buffer api is used to do the page spanning work required to

 * have a metadata blocksize different from the page size.

 */



#define BTRFS_SETGET_FUNCS(name, type, member, bits)			\

u##bits btrfs_##name(struct extent_buffer *eb, type *s);		\

void btrfs_set_##name(struct extent_buffer *eb, type *s, u##bits val);	\

void btrfs_set_token_##name(struct extent_buffer *eb, type *s, u##bits val, struct btrfs_map_token *token);	\

u##bits btrfs_token_##name(struct extent_buffer *eb,				\

			   type *s, struct btrfs_map_token *token)	\

#define DEFINE_BTRFS_SETGET_BITS(bits)					\

u##bits btrfs_get_token_##bits(struct extent_buffer *eb, void *ptr,	\

			       unsigned long off,			\

			       struct btrfs_map_token *token)		\

{									\

	unsigned long part_offset = (unsigned long)s;			\

	unsigned long offset = part_offset + offsetof(type, member);	\

	type *p;							\

	unsigned long part_offset = (unsigned long)ptr;			\

	unsigned long offset = part_offset + off;			\

	void *p;							\

	int err;							\

	char *kaddr;							\

	unsigned long map_start;					\

	unsigned long map_len;						\

	unsigned long mem_len = sizeof(((type *)0)->member);	\

	int size = sizeof(u##bits);					\

	u##bits res;							\

									\

	if (token && token->kaddr && token->offset <= offset &&		\

	    token->eb == eb &&						\

	   (token->offset + PAGE_CACHE_SIZE >= offset + mem_len)) { \

	   (token->offset + PAGE_CACHE_SIZE >= offset + size)) {	\

		kaddr = token->kaddr;					\

		p = (type *)(kaddr + part_offset - token->offset);  \

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

		p = kaddr + part_offset - token->offset;		\

		res = get_unaligned_le##bits(p + off);			\

		return res;						\

	}								\

	err = map_private_extent_buffer(eb, offset,		\

			mem_len,				\

	err = map_private_extent_buffer(eb, offset, size,		\

					&kaddr, &map_start, &map_len);	\

	if (err) {							\

		__le##bits leres;					\

		read_eb_member(eb, s, type, member, &leres);	\

									\

		read_extent_buffer(eb, &leres, offset, size);		\

		return le##bits##_to_cpu(leres);			\

	}								\

	p = (type *)(kaddr + part_offset - map_start);		\

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

	p = kaddr + part_offset - map_start;				\

	res = get_unaligned_le##bits(p + off);				\

	if (token) {							\

		token->kaddr = kaddr;					\

		token->offset = map_start;				\
@@ -82,54 +89,49 @@ u##bits btrfs_token_##name(struct extent_buffer *eb, \ 
	}								\

	return res;							\

}									\

void btrfs_set_token_##name(struct extent_buffer *eb,				\

			    type *s, u##bits val, struct btrfs_map_token *token)		\

void btrfs_set_token_##bits(struct extent_buffer *eb,			\

			    void *ptr, unsigned long off, u##bits val,	\

			    struct btrfs_map_token *token)		\

{									\

	unsigned long part_offset = (unsigned long)s;			\

	unsigned long offset = part_offset + offsetof(type, member);	\

	type *p;							\

	unsigned long part_offset = (unsigned long)ptr;			\

	unsigned long offset = part_offset + off;			\

	void *p;							\

	int err;							\

	char *kaddr;							\

	unsigned long map_start;					\

	unsigned long map_len;						\

	unsigned long mem_len = sizeof(((type *)0)->member);	\

	int size = sizeof(u##bits);					\

									\

	if (token && token->kaddr && token->offset <= offset &&		\

	    token->eb == eb &&						\

	   (token->offset + PAGE_CACHE_SIZE >= offset + mem_len)) { \

	   (token->offset + PAGE_CACHE_SIZE >= offset + size)) {	\

		kaddr = token->kaddr;					\

		p = (type *)(kaddr + part_offset - token->offset);  \

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

		p = kaddr + part_offset - token->offset;		\

		put_unaligned_le##bits(val, p + off);			\

		return;							\

	}								\

	err = map_private_extent_buffer(eb, offset,		\

			mem_len,				\

	err = map_private_extent_buffer(eb, offset, size,		\

			&kaddr, &map_start, &map_len);			\

	if (err) {							\

		__le##bits val2;					\

									\

		val2 = cpu_to_le##bits(val);				\

		write_eb_member(eb, s, type, member, &val2);	\

		write_extent_buffer(eb, &val2, offset, size);		\

		return;							\

	}								\

	p = (type *)(kaddr + part_offset - map_start);		\

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

	p = kaddr + part_offset - map_start;				\

	put_unaligned_le##bits(val, p + off);				\

	if (token) {							\

		token->kaddr = kaddr;					\

		token->offset = map_start;				\

		token->eb = eb;						\

	}								\

}								\

void btrfs_set_##name(struct extent_buffer *eb,			\

		      type *s, u##bits val)			\

{								\

	btrfs_set_token_##name(eb, s, val, NULL);		\

}								\

u##bits btrfs_##name(struct extent_buffer *eb,			\

		      type *s)					\

{								\

	return btrfs_token_##name(eb, s, NULL);			\

}								\

}



#include "ctree.h"

DEFINE_BTRFS_SETGET_BITS(8)

DEFINE_BTRFS_SETGET_BITS(16)

DEFINE_BTRFS_SETGET_BITS(32)

DEFINE_BTRFS_SETGET_BITS(64)



void btrfs_node_key(struct extent_buffer *eb,

		    struct btrfs_disk_key *disk_key, int nr)

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