btrfs: factor out metadata subpage detection into a dedicated helper

Currently we have only one btrfs_is_subpage() to cover both data and
metadata.

But there is a special case for metadata:

- dummy extent buffer, sector size < PAGE_SIZE and node size >= PAGE_SIZE

In such case, btrfs_is_subpage() will return true for extent buffer
folio.

But that is not correct, and that's exactly why we have some open-coded
checks for functions like set_extent_buffer_uptodate() and
clear_extent_buffer_uptodate().

Just extract the metadata specific checks into a helper, and replace
those call sites.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/fs/btrfs/subpage.c b/fs/btrfs/subpage.c
index a99c3163e9e0..e34694f0cdcc 100644
--- a/fs/btrfs/subpage.c
+++ b/fs/btrfs/subpage.c
@@ -169,7 +169,7 @@ void btrfs_folio_inc_eb_refs(const struct btrfs_fs_info *fs_info, struct folio *
 {
 	struct btrfs_subpage *subpage;
 
-	if (!btrfs_is_subpage(fs_info, folio->mapping))
+	if (!btrfs_meta_is_subpage(fs_info))
 		return;
 
 	ASSERT(folio_test_private(folio) && folio->mapping);
@@ -183,7 +183,7 @@ void btrfs_folio_dec_eb_refs(const struct btrfs_fs_info *fs_info, struct folio *
 {
 	struct btrfs_subpage *subpage;
 
-	if (!btrfs_is_subpage(fs_info, folio->mapping))
+	if (!btrfs_meta_is_subpage(fs_info))
 		return;
 
 	ASSERT(folio_test_private(folio) && folio->mapping);