[PATCH v2] nvme-cli: user-defined hostnqn option for discover

[J Freyensee]

On Tue, 2016-08-02 at 09:48 +0300, Sagi Grimberg wrote:
> > > Any chance you could also send a patch that reads
> > > /etc/nvme/hostnqn
> > > for a default hostnqn so that we can have a persistent one?
> > 
> > I'm a tad unclear what is the request? The default hostnqn is
> > buried
> > inside /dev/nvme-fabrics.  You want nvme-cli to read out the
> > default
> > hostnqn from /dev/nvme-fabrics and place it in  /etc/nvme/hostnqn?
> 
> I think Christoph is requesting that when the user doesn't pass a
> hostnqn, nvme-cli will try to read it from a file located in
> /etc/nvme/hostnqn (and if this doesn't exist then go ahead without
> it). This way, the host can have a persistent hostnqn across reboots
> (the driver generates one on module init time).

hmmm...the scenario I set up that found this issue, the host generates
a default hostnqn in the nvme-fabrics driver at init().  And if there
is no --hostnqn flag passed, the /dev/nvme-fabrics driver will use the
default generated by the nvme-fabrics driver at init().  And no
/etc/nvme/hostnqn file gets created or exists currently.

So is the request to have nvme-cli use whatever is in /etc/nvme/hostnqn
 (if it exists) over the default in the nvme-fabrics driver?  So
preference of hostnqn input would be:

1. --hostnqn flag
2. /etc/nvme/hostnqn
3. default hostnqn generated by nvme-fabrics driver (ex: nqn.2014
-08.org.nvmexpress:NVMf:uuid:a2d7752c-a31b-477a-a003-31a5e1c424a9)

(note 2. may contain a hostnqn different from the default)

??