f2fs: use f2fs_filemap_get_folio() to support fault injection

Use f2fs_filemap_get_folio() instead of __filemap_get_folio() in:
- f2fs_find_data_folio
- f2fs_write_begin
- f2fs_read_merkle_tree_page

So that, we can trigger fault injection in those places.

Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Author: chaseyu

fs/f2fs/data.c

@@ -1273,7 +1273,7 @@ struct folio *f2fs_find_data_folio(struct inode *inode, pgoff_t index,
 	struct address_space *mapping = inode->i_mapping;
 	struct folio *folio;
 
-	folio = __filemap_get_folio(mapping, index, FGP_ACCESSED, 0);
+	folio = f2fs_filemap_get_folio(mapping, index, FGP_ACCESSED, 0);
 	if (IS_ERR(folio))
 		goto read;
 	if (folio_test_uptodate(folio))
@@ -3567,7 +3567,7 @@ static int f2fs_write_begin(const struct kiocb *iocb,
 	 * Do not use FGP_STABLE to avoid deadlock.
 	 * Will wait that below with our IO control.
 	 */
-	folio = __filemap_get_folio(mapping, index,
+	folio = f2fs_filemap_get_folio(mapping, index,
 				FGP_LOCK | FGP_WRITE | FGP_CREAT | FGP_NOFS,
 				mapping_gfp_mask(mapping));
 	if (IS_ERR(folio)) {

fs/f2fs/verity.c

@@ -263,7 +263,7 @@ static struct page *f2fs_read_merkle_tree_page(struct inode *inode,
 
 	index += f2fs_verity_metadata_pos(inode) >> PAGE_SHIFT;
 
-	folio = __filemap_get_folio(inode->i_mapping, index, FGP_ACCESSED, 0);
+	folio = f2fs_filemap_get_folio(inode->i_mapping, index, FGP_ACCESSED, 0);
 	if (IS_ERR(folio) || !folio_test_uptodate(folio)) {
 		DEFINE_READAHEAD(ractl, NULL, NULL, inode->i_mapping, index);