From: Li Zefan <lizefan@huawei.com>
To: "linux-btrfs@vger.kernel.org" <linux-btrfs@vger.kernel.org>
Subject: [PATCH] Btrfs: rewrite BTRFS_SETGET_FUNCS
Date: Tue, 10 Jul 2012 10:22:35 +0800 [thread overview]
Message-ID: <4FFB91EB.9070305@huawei.com> (raw)
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: Li Zefan <lizefan@huawei.com>
---
fs/btrfs/ctree.h | 53 +++++++++++--
fs/btrfs/struct-funcs.c | 196 ++++++++++++++++++++++++-----------------------
2 files changed, 146 insertions(+), 103 deletions(-)
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 6761490..e262362 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -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) \
diff --git a/fs/btrfs/struct-funcs.c b/fs/btrfs/struct-funcs.c
index c6ffa58..1f4ede9 100644
--- a/fs/btrfs/struct-funcs.c
+++ b/fs/btrfs/struct-funcs.c
@@ -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
@@ -33,103 +45,93 @@
* 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; \
- int err; \
- char *kaddr; \
- unsigned long map_start; \
- unsigned long map_len; \
- unsigned long mem_len = sizeof(((type *)0)->member); \
- u##bits res; \
- if (token && token->kaddr && token->offset <= offset && \
- token->eb == eb && \
- (token->offset + PAGE_CACHE_SIZE >= offset + mem_len)) { \
- kaddr = token->kaddr; \
- p = (type *)(kaddr + part_offset - token->offset); \
- res = le##bits##_to_cpu(p->member); \
- return res; \
- } \
- err = map_private_extent_buffer(eb, offset, \
- mem_len, \
- &kaddr, &map_start, &map_len); \
- if (err) { \
- __le##bits leres; \
- read_eb_member(eb, s, type, member, &leres); \
- return le##bits##_to_cpu(leres); \
- } \
- p = (type *)(kaddr + part_offset - map_start); \
- res = le##bits##_to_cpu(p->member); \
- if (token) { \
- token->kaddr = kaddr; \
- token->offset = map_start; \
- token->eb = eb; \
- } \
- return res; \
+ 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; \
+ int size = sizeof(u##bits); \
+ u##bits res; \
+ \
+ if (token && token->kaddr && token->offset <= offset && \
+ token->eb == eb && \
+ (token->offset + PAGE_CACHE_SIZE >= offset + size)) { \
+ kaddr = token->kaddr; \
+ p = kaddr + part_offset - token->offset; \
+ res = get_unaligned_le##bits(p + off); \
+ return res; \
+ } \
+ err = map_private_extent_buffer(eb, offset, size, \
+ &kaddr, &map_start, &map_len); \
+ if (err) { \
+ __le##bits leres; \
+ \
+ read_extent_buffer(eb, &leres, offset, size); \
+ return le##bits##_to_cpu(leres); \
+ } \
+ p = kaddr + part_offset - map_start; \
+ res = get_unaligned_le##bits(p + off); \
+ if (token) { \
+ token->kaddr = kaddr; \
+ token->offset = map_start; \
+ token->eb = 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; \
- int err; \
- char *kaddr; \
- unsigned long map_start; \
- unsigned long map_len; \
- unsigned long mem_len = sizeof(((type *)0)->member); \
- if (token && token->kaddr && token->offset <= offset && \
- token->eb == eb && \
- (token->offset + PAGE_CACHE_SIZE >= offset + mem_len)) { \
- kaddr = token->kaddr; \
- p = (type *)(kaddr + part_offset - token->offset); \
- p->member = cpu_to_le##bits(val); \
- return; \
- } \
- err = map_private_extent_buffer(eb, offset, \
- mem_len, \
- &kaddr, &map_start, &map_len); \
- if (err) { \
- __le##bits val2; \
- val2 = cpu_to_le##bits(val); \
- write_eb_member(eb, s, type, member, &val2); \
- return; \
- } \
- p = (type *)(kaddr + part_offset - map_start); \
- p->member = cpu_to_le##bits(val); \
- 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); \
-} \
+ 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; \
+ int size = sizeof(u##bits); \
+ \
+ if (token && token->kaddr && token->offset <= offset && \
+ token->eb == eb && \
+ (token->offset + PAGE_CACHE_SIZE >= offset + size)) { \
+ kaddr = token->kaddr; \
+ p = kaddr + part_offset - token->offset; \
+ put_unaligned_le##bits(val, p + off); \
+ return; \
+ } \
+ 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_extent_buffer(eb, &val2, offset, size); \
+ return; \
+ } \
+ 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; \
+ } \
+}
-#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)
--
1.7.9.7
reply other threads:[~2012-07-10 2:22 UTC|newest]
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