[PATCH 05/10] nvme: add ANA support

[hare@suse.de (Hannes Reinecke)]

On Wed,  6 Jun 2018 16:33:06 +0200
Christoph Hellwig <hch@lst.de> wrote:

> Add support for Asynchronous Namespace Access as specified in NVMe 1.3
> TP 4004.  With ANA each namespace attached to a controller belongs to
> an ANA group that describes the characteristics of accessing the
> namespaces through this controller.  In the optimized and
> non-optimized states namespaces can be accessed regularly, although
> in a multi-pathing environment we should always prefer to access a
> namespace through a controller where an optimized relationship
> exists.  Namespaces in Inaccessible, Permanent-Loss or Change state
> for a given controller should not be accessed.
> 
> We keep a simple per-controller array of ANA states which is indexed
> by the ANA group ID specified in the namespace.  The states are
> updated through reading the ANA log page, which is read once during
> controller initialization, and whenever the ANA change notice AEN is
> received, or when one of the ANA specific status codes that signal a
> state change is received on a command.
> 
> There currently isn't any support for the ANA transition timeout
> yet.
> 
> Includes fixes and improvements from Hannes Reinecke.
> 
> Signed-off-by: Christoph Hellwig <hch at lst.de>
> ---
>  drivers/nvme/host/core.c      |  30 +++++-
>  drivers/nvme/host/multipath.c | 211
> ++++++++++++++++++++++++++++++++++++++++--
> drivers/nvme/host/nvme.h      |  28 ++++++ 3 files changed, 262
> insertions(+), 7 deletions(-)
> 

Reviewed-by: Hannes Reinecke <hare at suse.com>

Cheers,

Hannes