nfs/blocklayout: add SCSI layout support
This is a trivial extension to the block layout driver to support the
new SCSI layouts draft. There are three changes:
- device identifcation through the SCSI VPD page. This allows us to
directly use the udev generated persistent device names instead of
requiring an expensive lookup by crawling every block device node
in /dev and reading a signature for it.
- use of SCSI persistent reservations to protect device access and
allow for robust fencing. On the client sides this just means
registering and unregistering a server supplied key.
- an optimized LAYOUTCOMMIT payload that doesn't send unessecary
fields to the server.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
5 files changed