This VFS module is part of the samba(7) suite.
The aio_fork VFS module enables async I/O for Samba on platforms where the system level Posix AIO
interface is insufficient. Posix AIO can suffer from severe limitations. For example, on some Linux
versions the real-time signals that it uses are broken under heavy load. Other systems only allow AIO
when special kernel modules are loaded or only allow a certain system-wide amount of async requests being
scheduled. Systems based on glibc (most Linux systems) only allow a single outstanding request per file
descriptor.
To work around all these limitations, the aio_fork module was written. It uses forked helper processes
instead of the internal Posix AIO interface to create asynchronousity for read and write calls. It has no
parameters, it will create helper processes when async requests come in as needed. Idle helper processes
will be removed every 30 seconds.
This module is stackable.