On Fri, Aug 01 2008, Dan Williams wrote: > > On Fri, 2008-08-01 at 10:40 -0700, Jens Axboe wrote: > > On Fri, Aug 01 2008, Dan Williams wrote: > > > > > > On Fri, 2008-08-01 at 19:22 +0200, Jens Axboe wrote: > > > > It is a bit asymmetrical, largely due to the fact that the ->unplug_fn() > > > > itself grabs the lock. The below patch should fix it, since Neil has > > > > added a proper queue lock to the md queues. If someone can confirm that > > > > this fixes it, I'll queue up a patch with proper descriptions. > > > > > > > > > I guess Jens is gone too.. > > > > > > > > I'm back, just been busy this week :-) > > > > > > > > diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c > > > > index 621a272..f19b52f 100644 > > > > --- a/drivers/md/bitmap.c > > > > +++ b/drivers/md/bitmap.c > > > > @@ -1234,7 +1234,9 @@ int bitmap_startwrite(struct bitmap *bitmap, sector_t offset, unsigned long sect > > > > case 0: > > > > bitmap_file_set_bit(bitmap, offset); > > > > bitmap_count_page(bitmap,offset, 1); > > > > + spin_lock_irq(&bitmap->mddev->queue->queue_lock); > > > > blk_plug_device(bitmap->mddev->queue); > > > > + spin_unlock_irq(&bitmap->mddev->queue->queue_lock); > > > > /* fall through */ > > > > case 1: > > > > *bmc = 2; > > > > > > > > > > We also need to protect the blk_plug_device call a few lines down (and > > > an obvious compile fix). > > > > Old source I guess, just one blk_plug_device() in the copy I have here. > > Just checked latest git, still just one blk_plug_device(), are you > > diffing against -mm or something like that? Or linux-next? > > No, my mistake... I crossed my eyes and misread your patch as protecting > blk_unplug() a few lines up, sorry. Ah, didn't read that closely in your patch, that would get you into trouble :-) > > And queue_lock is of course a pointer, I didn't even compile the > > thing... Thanks for the updated variant! > > I have verified that: > > mdadm --create /dev/md0 /dev/sd[bc] -n 2 -l 1 --bitmap=internal > dd if=/dev/zero of=/dev/md0 bs=1024k count=1 > > ...no longer triggers the warning with your fix. Goodie, thanks! -- Jens Axboe -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
