Ceph

We should replace system() with a simple wrapper function that just does fork + exec.

The use of system() is wrong on a lot of different levels:

1. It's slow because it has to execute a shell process

2. It introduces serious security vulnerabilities.
For example, consider this code fragment:

string cmd("rm -rf ");
 cmd += filename;
 system(cmd.c_str());

What happens if filename is

`echo /`

3. While the call to system() is going on, signals are delivered not to the daemon, but to the process that is being executed in the system() shell. So ''killall -SIGTERM cosd'' will mysteriously fail to have any effect if we happen to deliver the signal to a thread that's doing system("rm -rf foo"). Instead, the rm will be terminated by the SIGTERM and return a negative error code.

Admittedly, this is less of a risk because we currently block signals in all threads but the main thread. But it's still another good reason not to use system.

We can write a simple wrapper function that just does fork + execvp and convert the system uses to that.