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 <mike.miller@xxxxxx> > > > > > > -------------------------------------------------------------------------------- > > > > > > --- > > > > > > 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. -- Jens Axboe - To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
