@@ -90,17 +90,20 @@ u##bits btrfs_get_##bits(const struct extent_buffer *eb, \
{ \
const unsigned long member_offset = (unsigned long)ptr + off; \
const unsigned long oip = offset_in_page(member_offset); \
+ const unsigned long idx = member_offset >> PAGE_SHIFT; \
+ char *kaddr = page_address(eb->pages[idx]); \
const int size = sizeof(u##bits); \
- __le##bits leres; \
+ const int part = PAGE_SIZE - oip; \
+ u8 lebytes[sizeof(u##bits)]; \
\
ASSERT(check_setget_bounds(eb, ptr, off, size)); \
- if (oip + size <= PAGE_SIZE) { \
- const unsigned long idx = member_offset >> PAGE_SHIFT; \
- const char *kaddr = page_address(eb->pages[idx]); \
+ if (oip + size <= PAGE_SIZE) \
return get_unaligned_le##bits(kaddr + oip); \
- } \
- read_extent_buffer(eb, &leres, member_offset, size); \
- return le##bits##_to_cpu(leres); \
+ \
+ memcpy(lebytes, kaddr + oip, part); \
+ kaddr = page_address(eb->pages[idx + 1]); \
+ memcpy(lebytes + part, kaddr, size - part); \
+ return get_unaligned_le##bits(lebytes); \
} \
void btrfs_set_token_##bits(struct btrfs_map_token *token, \
const void *ptr, unsigned long off, \
The helper read_extent_buffer is called to do read of the data spanning two extent buffer pages. As the size is known, we can do the read directly in two steps. This removes one function call and compiler can optimize memcpy as the sizes are known at compile time. Signed-off-by: David Sterba <dsterba@suse.com> --- fs/btrfs/struct-funcs.c | 17 ++++++++++------- 1 file changed, 10 insertions(+), 7 deletions(-)