Using the SC_NO_RESERVE Option

The SC_NO_RESERVE option causes the device driver to prohibit any reservation commands during the open of the device. This facilitates the sharing of the device by multiple hosts.

The device driver should require the caller to have appropriate authority to request the SC_NO_RESERVE option, because this request allows other hosts to modify data on the device. If a caller does this kind of request then the caller must ensure data integrity between multiple hosts. If the caller attempts to execute this system call without the proper authority, the device driver should return a value of -1, with the errno global variable set to a value of EPERM.