On Tue, Apr 05, 2016 at 04:45:55PM -0800, Kent Overstreet wrote: > On Tue, Apr 05, 2016 at 05:41:47PM -0700, Shaohua Li wrote: > > On Tue, Apr 05, 2016 at 04:36:04PM -0800, Kent Overstreet wrote: > > > On Tue, Apr 05, 2016 at 05:30:07PM -0700, Shaohua Li wrote: > > > > this one: > > > > http://marc.info/?l=linux-kernel&m=145926976808760&w=2 > > > > > > Ah. that patch won't actually fix the bug, since md isn't using > > > blk_default_limits, it's using blk_set_stacking_limits(). > > > > Not really, the limit is set by under layer disk not md, otherwise it > > should be BLK_SAFE_MAX_SECTORS, but the reported bio has 2560 sectors. > > blk_set_stacking_limits() will use it. > > What? Well, that could should just be deleted, there's no reason anymore for md > to care about the queue limits of the devices underneath it. > > Regardless, using BLK_DEF_MAX_SECTORS to limit # of pages in the biovec is > _crazy_. Why would you even do that? We have a separate field in queue limits > for # max segments, use it. We don't limit the max segments in blk_queue_max_segments(), but we can add. On the other hand, limit max segments to 256 could be a problem, because bvec page isn't always 4k, this might make some bio smaller. -- To unsubscribe from this list: send the line "unsubscribe linux-block" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
