rbd: another set of patches

The first set of patches has already been posted for review.

It is based on the current state of the ceph-client/testing branch, and is available as branch "wip-rbd-review-1" on the ceph-client git repository.

https://github.com/ceph/ceph-client/tree/wip-rbd-review-1

Most of these have been reviewed, and I will not be re-posting them here today.

-Alex

[PATCH 01/11]  rbd: handle locking inside __rbd_client_find()
[PATCH 02/11]  rbd: don't over-allocate space for object prefix
[PATCH 03/11]  rbd: kill incore snap_names_len
[PATCH 04/11]  rbd: more cleanup in rbd_header_from_disk()
[PATCH 05/11]  rbd: move rbd_opts to struct rbd_device
[PATCH 06/11]  rbd: add read_only rbd map option
[PATCH 07/11]  rbd: kill notify_timeout option
[PATCH 08/11]  rbd: bio_chain_clone() cleanups
[PATCH 09/11]  rbd: drop needless test in rbd_rq_fn()
[PATCH 10/11]  rbd: check for overflow in rbd_get_num_segments()
[PATCH 11/11]  rbd: split up rbd_get_segment()