return distance < len;
}
-static void copy_pages(struct page *dst_page, struct page *src_page,
- unsigned long dst_off, unsigned long src_off,
- unsigned long len)
-{
- char *dst_kaddr = page_address(dst_page);
- char *src_kaddr;
- int must_memmove = 0;
-
- if (dst_page != src_page) {
- src_kaddr = page_address(src_page);
- } else {
- src_kaddr = dst_kaddr;
- if (areas_overlap(src_off, dst_off, len))
- must_memmove = 1;
- }
-
- if (must_memmove)
- memmove(dst_kaddr + dst_off, src_kaddr + src_off, len);
- else
- memcpy(dst_kaddr + dst_off, src_kaddr + src_off, len);
-}
-
void memcpy_extent_buffer(const struct extent_buffer *dst,
unsigned long dst_offset, unsigned long src_offset,
unsigned long len)
unsigned long dst_offset, unsigned long src_offset,
unsigned long len)
{
- size_t cur;
- size_t dst_off_in_page;
- size_t src_off_in_page;
unsigned long dst_end = dst_offset + len - 1;
unsigned long src_end = src_offset + len - 1;
- unsigned long dst_i;
- unsigned long src_i;
if (check_eb_range(dst, dst_offset, len) ||
check_eb_range(dst, src_offset, len))
return;
+
if (dst_offset < src_offset) {
memcpy_extent_buffer(dst, dst_offset, src_offset, len);
return;
}
+
while (len > 0) {
- dst_i = get_eb_page_index(dst_end);
+ unsigned long src_i;
+ size_t cur;
+ size_t dst_off_in_page;
+ size_t src_off_in_page;
+ void *src_addr;
+ bool use_memmove;
+
src_i = get_eb_page_index(src_end);
dst_off_in_page = get_eb_offset_in_page(dst, dst_end);
cur = min_t(unsigned long, len, src_off_in_page + 1);
cur = min(cur, dst_off_in_page + 1);
- copy_pages(dst->pages[dst_i], dst->pages[src_i],
- dst_off_in_page - cur + 1,
- src_off_in_page - cur + 1, cur);
+
+ src_addr = page_address(dst->pages[src_i]) + src_off_in_page -
+ cur + 1;
+ use_memmove = areas_overlap(src_end - cur + 1, dst_end - cur + 1,
+ cur);
+
+ __write_extent_buffer(dst, src_addr, dst_end - cur + 1, cur,
+ use_memmove);
dst_end -= cur;
src_end -= cur;