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>
We generally want to read and write to a block device that's used by
the pNFS block layout client (and even if it's read only the server
has no way of telling us). Add FMODE_WRITE to the mode argument
so that we don't incorrectly tell the block driver that we want a
read-only open.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Instead of overwriting kernel memory reject too long signatures.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Use of synchronize_rcu() when unmounting and potentially freeing a lot
of deviceids is problematic. There really is no reason why we can't just
use kfree_rcu() here.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
This patches moves parsing of the GETDEVICEINFO XDR to kernel space, as well
as the management of complex devices. The reason for that is we might have
multiple outstanding complex devices after a NOTIFY_DEVICEID4_CHANGE, which
device mapper or md can't handle as they claim devices exclusively.
But as is turns out simple striping / concatenation is fairly trivial to
implement anyway, so we make our life simpler by reducing the reliance
on blkmapd. For now we still use blkmapd by feeding it synthetic SIMPLE
device XDR to translate device signatures to device numbers, but in the
long runs I have plans to eliminate it entirely.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
