diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index afe18880eb68..7ed0463dc56e 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -2707,6 +2707,8 @@ static ssize_t f2fs_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
 
 	ret = generic_write_checks(iocb, from);
 	if (ret > 0) {
+		bool preallocated = false;
+		size_t target_size = 0;
 		int err;
 
 		if (iov_iter_fault_in_readable(from, iov_iter_count(from)))
@@ -2723,6 +2725,9 @@ static ssize_t f2fs_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
 				}
 
 		} else {
+			preallocated = true;
+			target_size = iocb->ki_pos + iov_iter_count(from);
+
 			err = f2fs_preallocate_blocks(iocb, from);
 			if (err) {
 				clear_inode_flag(inode, FI_NO_PREALLOC);
@@ -2735,6 +2740,10 @@ static ssize_t f2fs_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
 		blk_finish_plug(&plug);
 		clear_inode_flag(inode, FI_NO_PREALLOC);
 
+		/* if we couldn't write data, we should deallocate blocks. */
+		if (preallocated && i_size_read(inode) < target_size)
+			f2fs_truncate(inode);
+
 		if (ret > 0)
 			f2fs_update_iostat(F2FS_I_SB(inode), APP_WRITE_IO, ret);
 	}