btrfs: convert put_file_data() to folios

Use folio instead of page in put_file_data(). Add a warning in case
higher order folio is found, this will be implemented in the future.
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/send.c

@@ -5274,10 +5274,11 @@ static int put_file_data(struct send_ctx *sctx, u64 offset, u32 len)
 {
 	struct btrfs_root *root = sctx->send_root;
 	struct btrfs_fs_info *fs_info = root->fs_info;
-	struct page *page;
+	struct folio *folio;
 	pgoff_t index = offset >> PAGE_SHIFT;
 	pgoff_t last_index;
 	unsigned pg_offset = offset_in_page(offset);
+	struct address_space *mapping = sctx->cur_inode->i_mapping;
 	int ret;
 
 	ret = put_data_header(sctx, len);
@@ -5290,44 +5291,44 @@ static int put_file_data(struct send_ctx *sctx, u64 offset, u32 len)
 		unsigned cur_len = min_t(unsigned, len,
 					 PAGE_SIZE - pg_offset);
 
-		page = find_lock_page(sctx->cur_inode->i_mapping, index);
-		if (!page) {
-			page_cache_sync_readahead(sctx->cur_inode->i_mapping,
+		folio = filemap_lock_folio(mapping, index);
+		if (IS_ERR(folio)) {
+			page_cache_sync_readahead(mapping,
 						  &sctx->ra, NULL, index,
 						  last_index + 1 - index);
 
-			page = find_or_create_page(sctx->cur_inode->i_mapping,
-						   index, GFP_KERNEL);
-			if (!page) {
-				ret = -ENOMEM;
+	                folio = filemap_grab_folio(mapping, index);
+			if (IS_ERR(folio)) {
+				ret = PTR_ERR(folio);
 				break;
 			}
 		}
 
-		if (PageReadahead(page))
-			page_cache_async_readahead(sctx->cur_inode->i_mapping,
-						   &sctx->ra, NULL, page_folio(page),
+		WARN_ON(folio_order(folio));
+
+		if (folio_test_readahead(folio))
+			page_cache_async_readahead(mapping, &sctx->ra, NULL, folio,
 						   index, last_index + 1 - index);
 
-		if (!PageUptodate(page)) {
-			btrfs_read_folio(NULL, page_folio(page));
-			lock_page(page);
-			if (!PageUptodate(page)) {
-				unlock_page(page);
+		if (!folio_test_uptodate(folio)) {
+			btrfs_read_folio(NULL, folio);
+			folio_lock(folio);
+			if (!folio_test_uptodate(folio)) {
+				folio_unlock(folio);
 				btrfs_err(fs_info,
 			"send: IO error at offset %llu for inode %llu root %llu",
-					page_offset(page), sctx->cur_ino,
+					folio_pos(folio), sctx->cur_ino,
 					sctx->send_root->root_key.objectid);
-				put_page(page);
+				folio_put(folio);
 				ret = -EIO;
 				break;
 			}
 		}
 
-		memcpy_from_page(sctx->send_buf + sctx->send_size, page,
-				 pg_offset, cur_len);
-		unlock_page(page);
-		put_page(page);
+		memcpy_from_folio(sctx->send_buf + sctx->send_size, folio,
+				  pg_offset, cur_len);
+		folio_unlock(folio);
+		folio_put(folio);
 		index++;
 		pg_offset = 0;
 		len -= cur_len;