Is there any way to override the flag on a device that permits it from being mounted twice? MNT_FORCE isn't it.
I've got an embedded environment I'm setting up where I want to transfer the root (/) file system from an rd(4) to an MFS. To do this, I have to add some customizations to copy() in sbin/newfs/newfs.c. This is because as soon as a I call mount_mfs(8) from my RD's /etc/rc, all of / goes away, so I have to accomplish thing in C functions until I can get the previous (/) re-mounted as /rescue. I can call mount(2) manually from newfs::copy(), but /dev/rd0a refuses to unmount from it's previous ubiquitous "root_device". Even if I explicitly mount /dev/rd0a as /, it refuses to dis-mount after I mount a new memfs at /, even with MNT_FORCE to unmount(2). Is it possible that rd(4)'s simply can't be unmounted? I'm assuming they can be, and that unlike their MFS counter-part, their contents do not reset (well, they would reset to whatever the contents of the RD image in the kernel is, assuming changes had been made). This is truly a chicken-and-egg scenario. Any thoughts would be appreciated. ~BAS
