*/
#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
* 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)
projects / ~andy / linux / blobdiff