Re: [PATCH 3/4] nvme: update the multipath warning in nvme_init_ns_head

[John Meneghini]

On 2/28/25 1:28 AM, Nilay Shroff wrote:
> On 2/28/25 8:55 AM, John Meneghini wrote:
> > The new NVME_MULTIPATH_PARAM config option requires updates
> > to the warning message in nvme_init_ns_head(). Remove
> > the old warning message and add new ones.
> >
> > Signed-off-by: John Meneghini <jmeneghi@xxxxxxxxxx>
> > ---
> >   drivers/nvme/host/core.c | 10 +++++++++-
> >   1 file changed, 9 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
> > index 818d4e49aab5..c2b7e6834535 100644
> > --- a/drivers/nvme/host/core.c
> > +++ b/drivers/nvme/host/core.c
> > @@ -3823,8 +3823,16 @@ static int nvme_init_ns_head(struct nvme_ns *ns, struct nvme_ns_info *info)
> >   			dev_warn(ctrl->device,
> >   				"Found shared namespace %d, but multipathing not supported.\n",
> >   				info->nsid);
> > +#ifdef CONFIG_NVME_MULTIPATH
> > +#ifdef CONFIG_NVME_MULTIPATH_PARAM
> > +			dev_warn_once(ctrl->device,
> > +				"Shared namespace support requires core.nvme_multipath=Y.\n");
> > +
> > +#endif
> > +#else
> >   			dev_warn_once(ctrl->device,
> > -				"Support for shared namespaces without CONFIG_NVME_MULTIPATH is deprecated and will be removed in Linux 6.0.\n");
> > +				"Shared namespace support requires CONFIG_NVME_MULTIPATH.\n");
> > +#endif
> >   		}
> >   	}
> >   
>
> As NVME_MULTIPATH_PARAM depends on NVME_MULTIPATH, it implicitly implies
> that if NVME_MULTIPATH_PARAM is enabled then NVME_MULTIPATH has to be on.
> So above logic could be simplified.
>
> However on another note, I really don't understand why do we need to add
> new warning here as there's already a warning present just above your
> changes.

Agreed.  How about if we just remove the

   	dev_warn_once(ctrl->device,
		"Support for shared namespaces without CONFIG_NVME_MULTIPATH is deprecated and will be removed in Linux 6.0.\n");
 
This is real problem.  This is a confusing message since there is no now plan to remove any of these config options from the kernel.

/John

> Thanks,
> --Nilay