hi Andrew,
On Tue, Aug 14, 2001 at 03:57:36PM -0700, Andrew Tridgell wrote:
> XFS doesn't open the logdev during use, which has two unfortunate
> consequences.
>
> The first is if you mount a XFS filesystem while the logdev device is
> not loaded (say for example if the logdev is on a device implemented
> in a kernel module). You get an oops from within linvfs_read_super()
> when it calls into the pagebug to ask for pages on a device that
^^^^^^^
Freudian slip? ;-)
> doesn't exist.
>
> The second is that the usage count of the logdev module remains at
> zero while the logdev is being used, which means it can be
> removed. Then you get an almost certain lockup when XFS next tries to
> use the log. It also means that someone else can come along and use
> the devive without any usage count tests kicking in.
>
> You can reproduce the effect by using a logdev on a ramdisk.
Steve's just sent me some notes on how to fix this - I'll get onto
it later today.
Thanks.
--
Nathan
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