On Mon, Jul 09 2012 at 10:57am -0400, Mike Snitzer <snit...@redhat.com> wrote:
> blk_set_stacking_limits() is intended to allow stacking drivers to build > up the limits of the stacked device based on the underlying devices' > limits. But in the case of 'max_sectors' the default of > BLK_DEF_MAX_SECTORS (1024) doesn't allow the stacking driver to inherit > a max_sectors larger than 1024. > > It is now clear that this artificial limit is getting in the way so > change blk_set_stacking_limits's max_sectors to UINT_MAX (which allows > stacking drivers like dm-multipath to inherit 'max_sectors' from the > underlying paths). > > blk_limits_max_hw_sectors() must allow stacking drivers to not have > max_sectors set to BLK_DEF_MAX_SECTORS as a side-effect. Move that > historic constraint to blk_queue_max_hw_sectors(). > > Reported-by: Vijay Chauhan <vijay.chau...@netapp.com> > Signed-off-by: Mike Snitzer <snit...@redhat.com> > Cc: Martin K. Petersen <martin.peter...@oracle.com> > --- > block/blk-settings.c | 8 ++++---- > 1 files changed, 4 insertions(+), 4 deletions(-) > > v2: tweak blk_limits_max_hw_sectors and blk_queue_max_hw_sectors As it happens, v2's changes to blk_limits_max_hw_sectors and blk_queue_max_hw_sectors are not strictly required in order for existing stacking drivers to have have an unconstrained max_sectors. Dropping those changes also allows for consistency across both block functions. So I'd be happy if v1 were to be staged for 3.6. NetApp: it would be great if you could confirm that v1 does in fact address the max_sectors issue you reported. Thanks, Mike -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
