On Thu, Dec 03, 2020 at 02:40:04PM +0800, Ming Lei wrote: > On Tue, Dec 01, 2020 at 05:54:18PM +0100, Christoph Hellwig wrote: > > Replace the gendisk pointer in struct bio with a pointer to the newly > > improved struct block device. From that the gendisk can be trivially > > accessed with an extra indirection, but it also allows to directly > > look up all information related to partition remapping. > > The extra indirection is often done in fast path, so just wondering why > you don't consider to embed gendisk into block_device? Then the extra > indirection can be avoided. oops, that is only possible for disk, and indirection is still needed for partitions. Thanks, Ming