diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c index 94116eaf47099ccad9f8ca458afd3c4f1e835435..798e468103b879f7986842028709be8852aa3dca 100644 --- a/drivers/md/dm-table.c +++ b/drivers/md/dm-table.c @@ -506,14 +506,13 @@ void dm_set_device_limits(struct dm_target *ti, struct block_device *bdev) rs->max_sectors = min_not_zero(rs->max_sectors, q->max_sectors); - /* FIXME: Device-Mapper on top of RAID-0 breaks because DM - * currently doesn't honor MD's merge_bvec_fn routine. - * In this case, we'll force DM to use PAGE_SIZE or - * smaller I/O, just to be safe. A better fix is in the - * works, but add this for the time being so it will at - * least operate correctly. + /* + * Check if merge fn is supported. + * If not we'll force DM to use PAGE_SIZE or + * smaller I/O, just to be safe. */ - if (q->merge_bvec_fn) + + if (q->merge_bvec_fn && !ti->type->merge) rs->max_sectors = min_not_zero(rs->max_sectors, (unsigned int) (PAGE_SIZE >> 9));