Re: [RFC/PATCH] Nonotify - A simplistic way to determine directory content changes

[nf <nf2 scheinwelt at>]

On Mon, 2004-06-07 at 19:00, Manuel Amador (Rudd-O) wrote: 
> I only see a challenge-response mechanism working as a long term
> solution.  Eject requests (system or user-initiated) *have*, at some
> point, to begin some process in-kernel that prepares the computer for CD
> ejection, and does WHATEVER is required to let the user eject the
> CD-ROM.
> 
> Or any other device.  Let's face it, device removals happen, and the
> system has to handle expected (cd-rom pushbutton press) and unexpected
> (yank of an usb device) failure from components, but it doesn't.  The
> kernel does not handle either case gracefully, locking CD-ROMS when
> mounted and with open files, and sometimes disabling the USB hub when
> pulling a drive out.  And when I say gracefully, I mean zero data
> corruption *and* minimum fuss for the user.

> We're not asking for the people at linux-kernel to "bend over", nor
> should we "bend over" either.  It's got to be a win-win solution!  But,
> just as we have to keep them in mind, so do they need to keep us in
> mind.  Linus has expressed his interest in desktop Linux, I'm sure he'll
> be positive on any proposed solution (so long as it is smart =).
> 
> 

A kind of "petition"-page which deals with all the "umount"-related issues would be good.
What do you think? Fixing those problems seems essential for the linux desktop.
Something to host on fd.org?
(I have tried to collect some links on http://www.scheinwelt.at/~norbertf/wbumount/ already).

I believe there are four main topics which need to be discussed on such a page:


A) Clean umount (option for Read-Write devices, like USB sticks):

-->A1 Directory monitoring and umount-blocking. The fam/dnotify/inotify/nonotify story.

-->A2 Umount blocking by desktop applications in general. 
My proposal: An interactive tool like "wbumount".


B) Device removal ("hot-unplugging") & forced umount.

-->B1 The "Let's face it" issue: Removing devices without prior umounting. 
Removable devices should be treated by the kernel like 
network filesystems (They can get detached by the user at any time and any state). 
That means: All drivers need timeouts.
I don't see the point in locking the tray of read-only devices like cd-roms for instance.

-->B2 Forced unmount (umount -f): Beeing able to shut down a filesystem, no matter which state it is in.


Norbert