From 54948681c21171a67c2fe03adcce54901e39dfe3 Mon Sep 17 00:00:00 2001 From: Qu Wenruo Date: Sat, 15 Jul 2023 19:08:31 +0800 Subject: [PATCH] btrfs: refactor main loop in copy_extent_buffer_full() [BACKGROUND] copy_extent_buffer_full() currently does different handling for regular and subpage cases, for regular cases it does a page by page copying. For subpage cases, it just copies the content. This is fine for the page based extent buffer code, but for the incoming folio conversion, it can be a burden to add a new branch just to handle all the different combinations (subpage vs regular, one single folio vs multi pages). [ENHANCE] Instead of handling the different combinations, just go one single handling for all cases, utilizing write_extent_buffer() to do the copying. Reviewed-by: Sweet Tea Dorminy Signed-off-by: Qu Wenruo Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/extent_io.c | 23 +++++++++-------------- 1 file changed, 9 insertions(+), 14 deletions(-) diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index dc15eaa..1ba8857 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -4190,24 +4190,19 @@ void memzero_extent_buffer(const struct extent_buffer *eb, unsigned long start, void copy_extent_buffer_full(const struct extent_buffer *dst, const struct extent_buffer *src) { - int i; - int num_pages; + unsigned long cur = 0; ASSERT(dst->len == src->len); - if (dst->fs_info->nodesize >= PAGE_SIZE) { - num_pages = num_extent_pages(dst); - for (i = 0; i < num_pages; i++) - copy_page(page_address(dst->pages[i]), - page_address(src->pages[i])); - } else { - size_t src_offset = get_eb_offset_in_page(src, 0); - size_t dst_offset = get_eb_offset_in_page(dst, 0); + while (cur < src->len) { + unsigned long index = get_eb_page_index(cur); + unsigned long offset = get_eb_offset_in_page(src, cur); + unsigned long cur_len = min(src->len, PAGE_SIZE - offset); + void *addr = page_address(src->pages[index]) + offset; + + write_extent_buffer(dst, addr, cur, cur_len); - ASSERT(src->fs_info->nodesize < PAGE_SIZE); - memcpy(page_address(dst->pages[0]) + dst_offset, - page_address(src->pages[0]) + src_offset, - src->len); + cur += cur_len; } } -- 2.7.4