btrfs: migrate subpage code to folio interfaces

Although subpage itself is conflicting with higher folio, since subpage
(sectorsize < PAGE_SIZE and nodesize < PAGE_SIZE) means we will never
need higher order folio, there is a hidden pitfall:

- btrfs_page_*() helpers

Those helpers are an abstraction to handle both subpage and non-subpage
cases, which means we're going to pass pages pointers to those helpers.

And since those helpers are shared between data and metadata paths, it's
unavoidable to let them to handle folios, including higher order
folios).

Meanwhile for true subpage case, we should only have a single page
backed folios anyway, thus add a new ASSERT() for btrfs_subpage_assert()
to ensure that.

Also since those helpers are shared between both data and metadata, add
some extra ASSERT()s for data path to make sure we only get single page
backed folio for now.

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

1 files changed, 20 insertions, 14 deletions

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index ac01f49161ff..b3e39610cc95 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -456,8 +456,8 @@ static inline void btrfs_cleanup_ordered_extents(struct btrfs_inode *inode,
 		 * range, then btrfs_mark_ordered_io_finished() will handle
 		 * the ordered extent accounting for the range.
 		 */
-		btrfs_page_clamp_clear_ordered(inode->root->fs_info, page,
-					       offset, bytes);
+		btrfs_folio_clamp_clear_ordered(inode->root->fs_info,
+						page_folio(page), offset, bytes);
 		put_page(page);
 	}
 
@@ -2802,7 +2802,7 @@ out_page:
 					       PAGE_SIZE, !ret);
 		clear_page_dirty_for_io(page);
 	}
-	btrfs_page_clear_checked(fs_info, page, page_start, PAGE_SIZE);
+	btrfs_folio_clear_checked(fs_info, page_folio(page), page_start, PAGE_SIZE);
 	unlock_page(page);
 	put_page(page);
 	kfree(fixup);
@@ -2857,7 +2857,7 @@ int btrfs_writepage_cow_fixup(struct page *page)
 	 * page->mapping outside of the page lock.
 	 */
 	ihold(inode);
-	btrfs_page_set_checked(fs_info, page, page_offset(page), PAGE_SIZE);
+	btrfs_folio_set_checked(fs_info, page_folio(page), page_offset(page), PAGE_SIZE);
 	get_page(page);
 	btrfs_init_work(&fixup->work, btrfs_writepage_fixup_worker, NULL);
 	fixup->page = page;
@@ -4776,9 +4776,10 @@ again:
 			memzero_page(page, (block_start - page_offset(page)) + offset,
 				     len);
 	}
-	btrfs_page_clear_checked(fs_info, page, block_start,
-				 block_end + 1 - block_start);
-	btrfs_page_set_dirty(fs_info, page, block_start, block_end + 1 - block_start);
+	btrfs_folio_clear_checked(fs_info, page_folio(page), block_start,
+				  block_end + 1 - block_start);
+	btrfs_folio_set_dirty(fs_info, page_folio(page), block_start,
+			      block_end + 1 - block_start);
 	unlock_extent(io_tree, block_start, block_end, &cached_state);
 
 	if (only_release_metadata)
@@ -8009,7 +8010,7 @@ static void btrfs_invalidate_folio(struct folio *folio, size_t offset,
 				page_end);
 		ASSERT(range_end + 1 - cur < U32_MAX);
 		range_len = range_end + 1 - cur;
-		if (!btrfs_page_test_ordered(fs_info, &folio->page, cur, range_len)) {
+		if (!btrfs_folio_test_ordered(fs_info, folio, cur, range_len)) {
 			/*
 			 * If Ordered (Private2) is cleared, it means endio has
 			 * already been executed for the range.
@@ -8018,7 +8019,7 @@ static void btrfs_invalidate_folio(struct folio *folio, size_t offset,
 			 */
 			goto next;
 		}
-		btrfs_page_clear_ordered(fs_info, &folio->page, cur, range_len);
+		btrfs_folio_clear_ordered(fs_info, folio, cur, range_len);
 
 		/*
 		 * IO on this page will never be started, so we need to account
@@ -8088,7 +8089,7 @@ next:
 	 * did something wrong.
 	 */
 	ASSERT(!folio_test_ordered(folio));
-	btrfs_page_clear_checked(fs_info, &folio->page, folio_pos(folio), folio_size(folio));
+	btrfs_folio_clear_checked(fs_info, folio, folio_pos(folio), folio_size(folio));
 	if (!inode_evicting)
 		__btrfs_release_folio(folio, GFP_NOFS);
 	clear_page_extent_mapped(&folio->page);
@@ -8112,6 +8113,7 @@ next:
 vm_fault_t btrfs_page_mkwrite(struct vm_fault *vmf)
 {
 	struct page *page = vmf->page;
+	struct folio *folio = page_folio(page);
 	struct inode *inode = file_inode(vmf->vma->vm_file);
 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 	struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
@@ -8128,6 +8130,8 @@ vm_fault_t btrfs_page_mkwrite(struct vm_fault *vmf)
 	u64 page_end;
 	u64 end;
 
+	ASSERT(folio_order(folio) == 0);
+
 	reserved_space = PAGE_SIZE;
 
 	sb_start_pagefault(inode->i_sb);
@@ -8231,9 +8235,9 @@ again:
 	if (zero_start != PAGE_SIZE)
 		memzero_page(page, zero_start, PAGE_SIZE - zero_start);
 
-	btrfs_page_clear_checked(fs_info, page, page_start, PAGE_SIZE);
-	btrfs_page_set_dirty(fs_info, page, page_start, end + 1 - page_start);
-	btrfs_page_set_uptodate(fs_info, page, page_start, end + 1 - page_start);
+	btrfs_folio_clear_checked(fs_info, folio, page_start, PAGE_SIZE);
+	btrfs_folio_set_dirty(fs_info, folio, page_start, end + 1 - page_start);
+	btrfs_folio_set_uptodate(fs_info, folio, page_start, end + 1 - page_start);
 
 	btrfs_set_inode_last_sub_trans(BTRFS_I(inode));
 
@@ -9819,7 +9823,9 @@ void btrfs_set_range_writeback(struct btrfs_inode *inode, u64 start, u64 end)
 		page = find_get_page(inode->vfs_inode.i_mapping, index);
 		ASSERT(page); /* Pages should be in the extent_io_tree */
 
-		btrfs_page_set_writeback(fs_info, page, start, len);
+		/* This is for data, which doesn't yet support larger folio. */
+		ASSERT(folio_order(page_folio(page)) == 0);
+		btrfs_folio_set_writeback(fs_info, page_folio(page), start, len);
 		put_page(page);
 		index++;
 	}