From fb22e9c4cd57e67aa9d62c8bbde5192349dc584a Mon Sep 17 00:00:00 2001 From: Qu Wenruo Date: Fri, 13 Nov 2020 20:51:49 +0800 Subject: [PATCH] btrfs: use detach_page_private() in alloc_extent_buffer() In alloc_extent_buffer(), after we got a page from btree inode, we check if that page has private pointer attached. If attached, we check if the existing extent buffer has proper refs. If not (the eb is being freed), we will detach that private eb pointer. The point here is, we are detaching that eb pointer by calling: - ClearPagePrivate() - put_page() The put_page() here is especially confusing, as it's decreasing the ref from attach_page_private(). Without knowing that, it looks like the put_page() is for the find_or_create_page() call, confusing the reader. Since we're always modifying page private with attach_page_private() and detach_page_private(), the only open-coded detach_page_private() here is really confusing. Fix it by calling detach_page_private(). Reviewed-by: Johannes Thumshirn Signed-off-by: Qu Wenruo Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/extent_io.c | 7 +------ 1 file changed, 1 insertion(+), 6 deletions(-) diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index cdccfdb..f514304 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -5278,13 +5278,8 @@ struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info, } exists = NULL; - /* - * Do this so attach doesn't complain and we need to - * drop the ref the old guy had. - */ - ClearPagePrivate(p); WARN_ON(PageDirty(p)); - put_page(p); + detach_page_private(p); } attach_extent_buffer_page(eb, p); spin_unlock(&mapping->private_lock); -- 2.7.4