From 1877e1a747db33d7264d8046e96373962da72a3d Mon Sep 17 00:00:00 2001 From: Zach Brown Date: Wed, 16 Oct 2013 12:10:33 -0700 Subject: [PATCH] btrfs: remove move_pages() 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 Signed-off-by: Josef Bacik Signed-off-by: Chris Mason --- 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 5439f24ab06b..5bf98d2ee70f 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -5082,23 +5082,6 @@ 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; @@ -5209,7 +5192,7 @@ 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); -- 2.11.0