On Wed, Dec 13, 2006 at 01:52:36PM +0100, Jens Axboe wrote:
> On Tue, Dec 12 2006, Mike Miller (OS Dev) wrote:
> > On Mon, Nov 06, 2006 at 09:32:00PM +0100, Jens Axboe wrote:
> > > On Mon, Nov 06 2006, Mike Miller (OS Dev) wrote:
> > > > PATCH 9 of 12
> > > >
> > > > This patch adds a check for busy_configuring to prevent starting a queue
> > > > on a drive that may be in the midst of updating, configuring, deleting, etc.
> > > >
> > > > This had a test for if the queue was stopped or plugged but that seemed
> > > > to cause issues.
> > > > Please consider this for inclusion.
> > > >
> > > > Thanks,
> > > > mikem
> > > >
> > > > Signed-off-by: Mike Miller <[email protected]>
> > > >
> > > > --------------------------------------------------------------------------------
> > > >
> > > > ---
> > > >
> > > > drivers/block/cciss.c | 5 ++++-
> > > > 1 files changed, 4 insertions(+), 1 deletion(-)
> > > >
> > > > diff -puN drivers/block/cciss.c~cciss_busy_conf_for_lx2619-rc4 drivers/block/cciss.c
> > > > --- linux-2.6/drivers/block/cciss.c~cciss_busy_conf_for_lx2619-rc4 2006-11-06 13:27:53.000000000 -0600
> > > > +++ linux-2.6-root/drivers/block/cciss.c 2006-11-06 13:27:53.000000000 -0600
> > > > @@ -1190,8 +1190,11 @@ static void cciss_check_queues(ctlr_info
> > > > /* make sure the disk has been added and the drive is real
> > > > * because this can be called from the middle of init_one.
> > > > */
> > > > - if (!(h->drv[curr_queue].queue) || !(h->drv[curr_queue].heads))
> > > > + if (!(h->drv[curr_queue].queue) ||
> > > > + !(h->drv[curr_queue].heads) ||
> > > > + h->drv[curr_queue].busy_configuring)
> > > > continue;
> > > > +
> > > > blk_start_queue(h->gendisk[curr_queue]->queue);
> > >
> > > This is racy, because you don't start the queue when you unset
> > > ->busy_configuring later on. For this to be safe, you need to call
> > > blk_start_queue() when you set ->busy_configuring to 0.
> >
> > Jens, please see Chase's reply to your concerns:
> > > busy_configuring - I do not think this is racy. This
> > > flag is used only when we are removing/deleting a disk. In
> > > this case the queue is cleaned up and the disk is deleted.
> > > If we are doing that then there is no queue to start later.
> > > The check of this flag in the interrupt handler is to prevent
> > > us from trying to start a queue that is in the middle of
> > > being deleted. This flag could be called busy_deleting.
>
> Ok, no worries then if it's simply a going away flag. I wonder if it's
> needed at all, but it certainly doesn't hurt.
hey Jens,
Just a poke since I haven't seen this change go into your block
tree. Is it still in-plan?
--
dann frazier
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
