move_pages() has an inefficient backwards byte copy of regions of two
different pages. They're different pages so the regions won't overlap
and it could use memcpy().
At that point, though, move_pages() would be a slightly dimmer
re-implementation of copy_pages() that lacked the test for overlapping
page regions.
So remove move_pages() and just call copy_pages().
Signed-off-by: Zach Brown <zab@xxxxxxxxxx>
---
fs/btrfs/extent_io.c | 19 +------------------
1 file changed, 1 insertion(+), 18 deletions(-)
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index c10291c..46a4022 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -5093,23 +5093,6 @@ void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src,
}
}
-static void move_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);
- if (dst_page == src_page) {
- memmove(dst_kaddr + dst_off, dst_kaddr + src_off, len);
- } else {
- char *src_kaddr = page_address(src_page);
- char *p = dst_kaddr + dst_off + len;
- char *s = src_kaddr + src_off + len;
-
- while (len--)
- *--p = *--s;
- }
-}
-
static inline bool areas_overlap(unsigned long src, unsigned long dst, unsigned long len)
{
unsigned long distance = (src > dst) ? src - dst : dst - src;
@@ -5220,7 +5203,7 @@ void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
cur = min_t(unsigned long, len, src_off_in_page + 1);
cur = min(cur, dst_off_in_page + 1);
- move_pages(extent_buffer_page(dst, dst_i),
+ copy_pages(extent_buffer_page(dst, dst_i),
extent_buffer_page(dst, src_i),
dst_off_in_page - cur + 1,
src_off_in_page - cur + 1, cur);
--
1.7.11.7
--
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