with EBUSY and a cdrom is not mounted at /cdrom, sysinstall fails to
treat it as an error and thinks that the disk mounted ok. However, it
doesn't find a cdrom.inf file so it complains. Later when it tries to
unmount the disk due to a mediaClose() umount(2) returns an error, and it
never clears its internal mounted flag. The fix here is to properly
handle EBUSY as an error if there isn't a CD already mounted at /cdrom.
- Add a new CDROMInitQuiet variable that can be used to shut up the dialog
box about the mount(2) system call failing when trying to mount a CD-ROM.
This is used by the feature described below.
- When using a fixit CD, first try to see if we can mount the disc in the
drive now and use it as a fixit CD. If not, then prompt the user to
insert the disc and try again. If we do succeed on the first "silent"
probe then we don't ask the user to eject the disk after leaving fixit
mode.
- Add a simple file existence test to make sure that the disc that we mount
really is a livefs disc.
- Explicitly switch back to ttyv0 when using the standard console after
the fixit shell dies. Previously this behavior worked accidentally
because all the fixit modes popped up a dialog box which contained a
hidden switch to ttyv0.
MFC after: 1 day
d61e43fe1e