Add queue resizing support

Just get rid of the preallocated command map, use the slab cache
to get/free commands instead.

Original patch from FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>,
changed by me to not use a mempool.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
1 file changed