带有FUSE的网络RAID FS，gcc -hello.c -o a.out，a.out不可执行

Question

I'm writing net raid FS with FUSE on ubuntu. Here are syscalls I've implemented: create open read write release unlink mkdir opendir readdir releasedir rmdir getattr and rename .

Everything works fine, but here is such case: I wrote "hello world" in c and tried typing this: gcc hello.c -o a.out . a.out is fine, but it's just a file, not executable (When I set manually 0777 permissions it executes fine on ./a.out ).

When permissions must be set, and how? And when compiling, how to know which files should be set exe permissions? Based on what?

Answer 1

I lacked chmod syscall implementation. chmod makes it work all right. Thanks @Barmar for help!