Re: 2.6.10-rc2-bk7 - kernel BUG at fs/sysfs/file.c:87!

From: Greg KH
Date: Wed Nov 24 2004 - 16:37:02 EST


On Wed, Nov 24, 2004 at 10:18:00PM +0100, Jens Axboe wrote:
> On Wed, Nov 24 2004, Maneesh Soni wrote:
> > On Wed, Nov 24, 2004 at 07:26:43PM +0000, Christopher S. Aker wrote:
> > > Doing "cat /sys/block/sda/queue/iosched/show_status" produces the following BUG:
> > >
> > > ------------[ cut here ]------------
> > > kernel BUG at fs/sysfs/file.c:87!
> >
> > I think you are using cfq io scheduler. show_status is from cfq_ioched. Looks
> > like return value freom cfq_status_show() is going beyond one page.
> > read/write buffer for sysfs text attribute files is limited to one page.
>
> Yeah, with many processes that is easy to hit. I dunno how to fix it
> yet, is it possible to combine sysfs with the seq stuff? The file should
> just be deleted, though.

sysfs files should have only 1 value per file. You really have a single
value that is bigger than a page size? :)

thanks,

greg k-h
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