btrfs: prepare extent_io.c for future large folio support

When we're handling folios from filemap, we can no longer assume all
folios are page sized.

Thus for call sites assuming the folio is page sized, change the
PAGE_SIZE usage to folio_size() instead.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

Author: adam900710

fs/btrfs/extent_io.c

@@ -425,7 +425,7 @@ static void end_folio_read(struct folio *folio, bool uptodate, u64 start, u32 le
 	struct btrfs_fs_info *fs_info = folio_to_fs_info(folio);
 
 	ASSERT(folio_pos(folio) <= start &&
-	       start + len <= folio_pos(folio) + PAGE_SIZE);
+	       start + len <= folio_pos(folio) + folio_size(folio));
 
 	if (uptodate && btrfs_verify_folio(folio, start, len))
 		btrfs_folio_set_uptodate(fs_info, folio, start, len);
@@ -492,7 +492,7 @@ static void begin_folio_read(struct btrfs_fs_info *fs_info, struct folio *folio)
 		return;
 
 	ASSERT(folio_test_private(folio));
-	btrfs_folio_set_lock(fs_info, folio, folio_pos(folio), PAGE_SIZE);
+	btrfs_folio_set_lock(fs_info, folio, folio_pos(folio), folio_size(folio));
 }
 
 /*
@@ -753,7 +753,7 @@ static void submit_extent_folio(struct btrfs_bio_ctrl *bio_ctrl,
 {
 	struct btrfs_inode *inode = folio_to_inode(folio);
 
-	ASSERT(pg_offset + size <= PAGE_SIZE);
+	ASSERT(pg_offset + size <= folio_size(folio));
 	ASSERT(bio_ctrl->end_io_func);
 
 	if (bio_ctrl->bbio &&
@@ -935,7 +935,7 @@ static int btrfs_do_readpage(struct folio *folio, struct extent_map **em_cached,
 	struct inode *inode = folio->mapping->host;
 	struct btrfs_fs_info *fs_info = inode_to_fs_info(inode);
 	u64 start = folio_pos(folio);
-	const u64 end = start + PAGE_SIZE - 1;
+	const u64 end = start + folio_size(folio) - 1;
 	u64 extent_offset;
 	u64 last_byte = i_size_read(inode);
 	struct extent_map *em;
@@ -1275,7 +1275,7 @@ static void set_delalloc_bitmap(struct folio *folio, unsigned long *delalloc_bit
 	unsigned int start_bit;
 	unsigned int nbits;
 
-	ASSERT(start >= folio_start && start + len <= folio_start + PAGE_SIZE);
+	ASSERT(start >= folio_start && start + len <= folio_start + folio_size(folio));
 	start_bit = (start - folio_start) >> fs_info->sectorsize_bits;
 	nbits = len >> fs_info->sectorsize_bits;
 	ASSERT(bitmap_test_range_all_zero(delalloc_bitmap, start_bit, nbits));
@@ -1293,7 +1293,7 @@ static bool find_next_delalloc_bitmap(struct folio *folio,
 	unsigned int first_zero;
 	unsigned int first_set;
 
-	ASSERT(start >= folio_start && start < folio_start + PAGE_SIZE);
+	ASSERT(start >= folio_start && start < folio_start + folio_size(folio));
 
 	start_bit = (start - folio_start) >> fs_info->sectorsize_bits;
 	first_set = find_next_bit(delalloc_bitmap, bitmap_size, start_bit);
@@ -1495,7 +1495,7 @@ static noinline_for_stack int writepage_delalloc(struct btrfs_inode *inode,
 		delalloc_end = page_end;
 	/*
 	 * delalloc_end is already one less than the total length, so
-	 * we don't subtract one from PAGE_SIZE
+	 * we don't subtract one from PAGE_SIZE.
 	 */
 	delalloc_to_write +=
 		DIV_ROUND_UP(delalloc_end + 1 - page_start, PAGE_SIZE);
@@ -1761,7 +1761,7 @@ static int extent_writepage(struct folio *folio, struct btrfs_bio_ctrl *bio_ctrl
 		goto done;
 
 	ret = extent_writepage_io(inode, folio, folio_pos(folio),
-				  PAGE_SIZE, bio_ctrl, i_size);
+				  folio_size(folio), bio_ctrl, i_size);
 	if (ret == 1)
 		return 0;
 	if (ret < 0)
@@ -2488,8 +2488,8 @@ void extent_write_locked_range(struct inode *inode, const struct folio *locked_f
 	ASSERT(IS_ALIGNED(start, sectorsize) && IS_ALIGNED(end + 1, sectorsize));
 
 	while (cur <= end) {
-		u64 cur_end = min(round_down(cur, PAGE_SIZE) + PAGE_SIZE - 1, end);
-		u32 cur_len = cur_end + 1 - cur;
+		u64 cur_end;
+		u32 cur_len;
 		struct folio *folio;
 
 		folio = filemap_get_folio(mapping, cur >> PAGE_SHIFT);
@@ -2499,13 +2499,18 @@ void extent_write_locked_range(struct inode *inode, const struct folio *locked_f
 		 * code is just in case, but shouldn't actually be run.
 		 */
 		if (IS_ERR(folio)) {
+			cur_end = min(round_down(cur, PAGE_SIZE) + PAGE_SIZE - 1, end);
+			cur_len = cur_end + 1 - cur;
 			btrfs_mark_ordered_io_finished(BTRFS_I(inode), NULL,
 						       cur, cur_len, false);
 			mapping_set_error(mapping, PTR_ERR(folio));
-			cur = cur_end + 1;
+			cur = cur_end;
 			continue;
 		}
 
+		cur_end = min_t(u64, folio_pos(folio) + folio_size(folio) - 1, end);
+		cur_len = cur_end + 1 - cur;
+
 		ASSERT(folio_test_locked(folio));
 		if (pages_dirty && folio != locked_folio)
 			ASSERT(folio_test_dirty(folio));
@@ -2617,7 +2622,7 @@ static bool try_release_extent_state(struct extent_io_tree *tree,
 				     struct folio *folio)
 {
 	u64 start = folio_pos(folio);
-	u64 end = start + PAGE_SIZE - 1;
+	u64 end = start + folio_size(folio) - 1;
 	bool ret;
 
 	if (test_range_bit_exists(tree, start, end, EXTENT_LOCKED)) {
@@ -2655,7 +2660,7 @@ static bool try_release_extent_state(struct extent_io_tree *tree,
 bool try_release_extent_mapping(struct folio *folio, gfp_t mask)
 {
 	u64 start = folio_pos(folio);
-	u64 end = start + PAGE_SIZE - 1;
+	u64 end = start + folio_size(folio) - 1;
 	struct btrfs_inode *inode = folio_to_inode(folio);
 	struct extent_io_tree *io_tree = &inode->io_tree;