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Re: usb flash drive removal (Re: Desktop NetBSD needs your help)



David Holland wrote:

> On Mon, Feb 09, 2009 at 11:57:01AM -0500, Arnaud Lacombe wrote:
>  > [assorted negativity about removable volumes]
> 
> I have one thing to say:
> 
> Bollocks.
> 
> Removable media weren't invented last year. There have been many
> operating systems that supported removable media correctly, including
> "real" OSes with VFS layers and write-back disk caching and the works.
> Many of these systems date back 25 years or more.
> 
> None of them, however, are Unix-derived. It is a disgrace that
> removable media handling in Unix has remained broken all this time.
> 
> This is what needs to be done:
> 
> (1) Automatically mounting media upon insertion creates a
> configuration management problem. Where do you mount the new volume,
> and how does this interact with existing config practices and
> /etc/fstab? If someone who understands this problem (which apparently
> excludes the freedesktop.org folks) can straighten it out, there's no
> particular further difficulty with mounting.
> 
> (2) Unmounting on removal for devices that don't have a door lock or
> some other mechanism to allow the OS to sync before ejecting requires
> a method to send the user on the console a nastygram of the form
> "REINSERT THAT AND WAIT FIVE SECONDS. OR ELSE." There is nothing
> difficult about this except that it involves writing an X program,
> although a more scalable solution requires a bit more integration with
> desktop goo. The reason this hasn't happened yet is that, AFAICT, the
> desktop folks don't understand what's required and the kernel folks
> don't really care enough to bother, or fight with the desktop folks
> over the color of the bikeshed^H^H^H^H^H^H^H^H^H window frame.
> 
> (3) Fixing the buffer cache code and whatever else is involved so it
> doesn't choke when an unexpected eject occurs is, though not entirely
> trivial, a SMOP.
> 
> (4) Fixing file system code so you can't panic or own the kernel by
> inserting a corrupt volume is, though not trivial, also perfectly
> straightforward.
> 
> All of this might have got done 12-14 years ago, too, except that
> floppies disappeared just around the time a critical mass of people
> started using Unix-derived OSes on machines that historically
> supported floppy drives and where floppy drives were expected to work
> properly.
> 
> -- 
> David A. Holland
> dholland%netbsd.org@localhost

The truth has been said, I agree with every word.

--
When in doubt, use brute force.

Adam Hoka <ahoka%NetBSD.org@localhost>
Adam Hoka <ahoka%MirBSD.de@localhost>
Adam Hoka <adam.hoka%gmail.com@localhost>

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