Revert "Fix read performance regression in ObjectCacher"

This reverts commit 65be257e9295619b960b49f6aa80ecdf8ea4d16a.

Too late for giant.

Signed-off-by: Sage Weil <sage@redhat.com>
Revert "rbd: ObjectCacher reads can hang when reading sparse files"

This reverts commit cdb7675a21c9107e3596c90c2b1598def3c6899f.

Signed-off-by: Sage Weil <sage@redhat.com>
Revert "Enforce cache size on read requests"

This reverts commit 4fc9fffc494abedac0a9b1ce44706343f18466f1.

Signed-off-by: Sage Weil <sage@redhat.com>
Merge pull request #2797 from ceph/wip-rbd-revert

rbd/objectcacher: revert recent changes for giant

Reviewed-by: Josh Durgin <josh.durgin@inktank.com>