f2fs: fix to handle filemap_fdatawrite() error in f2fs_ioc_decompress_file/f2fs_ioc_compress_file

It seems inappropriate that the current logic does not handle
filemap_fdatawrite() errors, so let's fix it.
Signed-off-by: Yangtao Li <frank.li@vivo.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/file.c

@@ -4063,8 +4063,11 @@ static int f2fs_ioc_decompress_file(struct file *filp)
 		if (ret < 0)
 			break;
 
-		if (get_dirty_pages(inode) >= blk_per_seg)
-			filemap_fdatawrite(inode->i_mapping);
+		if (get_dirty_pages(inode) >= blk_per_seg) {
+			ret = filemap_fdatawrite(inode->i_mapping);
+			if (ret < 0)
+				break;
+		}
 
 		count -= len;
 		page_idx += len;
@@ -4134,8 +4137,11 @@ static int f2fs_ioc_compress_file(struct file *filp)
 		if (ret < 0)
 			break;
 
-		if (get_dirty_pages(inode) >= blk_per_seg)
-			filemap_fdatawrite(inode->i_mapping);
+		if (get_dirty_pages(inode) >= blk_per_seg) {
+			ret = filemap_fdatawrite(inode->i_mapping);
+			if (ret < 0)
+				break;
+		}
 
 		count -= len;
 		page_idx += len;