[PATCH] nvme-core: update NS Attr Changed AEN handling for ANA group

[Christoph Hellwig]

On Wed, Nov 18, 2020 at 05:18:59PM +0530, Martin George wrote:
> From: Martin George <marting at netapp.com>
> 
> The current nvme rescan triggered in response to a NS Attr Changed
> AEN, fails to add a namespace if belonging to a new ANA group. This
> is because ana_log_buf->ngrps is not updated in nvme_parse_ana_log(),
> due to which it is unable to locate the new ANA group's descriptor,
> eventually resulting in the failure to add the namespace during the
> rescan. Fix this by reading the ANA log page as part of ana_work so
> that ngrps gets updated, prior to invoking nvme_queue_scan().

How can the namespace reference an ANA group that we haven't been
notified about using the NVME_AEN_CFG_ANA_CHANGE AEN before?