Bug#78011: storeio (in)activation (was: Re: CDROM lock)

[Roland McGrath]

> It gets, but because the way the code is written, dopen in libstore will be
> run twice, and one port to the device gets leaked. This lost port will block
> the drive until storeio is killed. (A workaround might be to check in dopen
> if the drive was already opened, or to check in store_set_flags if the flag
> is already set, likewise for clear).

As I read store_{set,clear}_flags, they will not make any function calls if
no backend flag bits are changing.  The store types' *_set_flags functions
should definitely not do anything stupid if called with STORE_INACTIVE
already in the same state, since there can be such calls for other flags
changing.