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authorZach Brown <zab@redhat.com>2013-10-16 12:10:33 -0700
committerChris Mason <chris.mason@fusionio.com>2013-11-11 22:03:09 -0500
commit1877e1a747db33d7264d8046e96373962da72a3d (patch)
treeb928d5a17bacd6644631d200e3a82232202b2aec /fs/btrfs
parent4546bcaeba435c1d0b7f38c011cbb2367497ca8d (diff)
downloadop-kernel-dev-1877e1a747db33d7264d8046e96373962da72a3d.zip
op-kernel-dev-1877e1a747db33d7264d8046e96373962da72a3d.tar.gz
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 <zab@redhat.com> Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Diffstat (limited to 'fs/btrfs')
-rw-r--r--fs/btrfs/extent_io.c19
1 files changed, 1 insertions, 18 deletions
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 5439f24..5bf98d2 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);
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