Re: How do I kill a process that is locked to a resource

Nathan Bryant (nathan@burgessinc.com)
Sat, 21 Dec 1996 10:12:47 -0500 (EST)


On Sat, 21 Dec 1996, William Burrow wrote:

> This unkillable process/unusable device deadlock does occur for floppy
> drives and externally powered devices (eg Zip drives). In the latter
> case, the power supply to the Zip drive could accidentally be yanked
> out. If the user does not notice this, then a process that accesses the
> drive will cause the deadlock. A reboot will be necessary.

This should not happen! In the case of the Zip drive, the driver should
implement a timeout after which it returns an error to the process.

Am I the only one who thinks the kernel needs better error handling in
these cases?

> In the case of the floppy drive, if one does the DOS-ish thing of popping
> out a diskette and putting another in while the first is still mounted,
> then one not only gets the deadlock when accessing the floppy again, but
> also an Oops.

There's no oops, at least on 2.0.27, but there is a panic. And process
will deadlock as you've described.

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