Re: [PATCH v3 1/2] nvme: multipath: enable BLK_FEAT_ATOMIC_WRITES for multipathing

[Chaitanya Kulkarni <chaitanyak@nvidia.com>]

On 5/8/25 15:38, Alan Adamson wrote:
> A change to QEMU resulted in all nvme controllers (single and
> multi-controller subsystems) to have its CMIC.MCTRS bit set which indicates
> the subsystem supports multiple controllers and it is possible a namespace
> can be shared between those multiple controllers in a multipathed
> configuration.
>
> When a namespace of a CMIC.MCTRS enabled subsystem is allocated, a
> multipath node is created.  The queue limits for this node are inherited
> from the namespace being allocated. When inheriting queue limits, the
> features being inherited need to be specified. The atomic write feature
> (BLK_FEAT_ATOMIC_WRITES) was not specified so the atomic queue limits
> were not inherited by the multipath disk node which resulted in the sysfs
> atomic write attributes being zeroed. The fix is to include
> BLK_FEAT_ATOMIC_WRITES in the list of features to be inherited.
>
> Signed-off-by: Alan Adamson<alan.adamson@oracle.com>
> Reviewed-by: John Garry<john.g.garry@oracle.com>

Looks good.

Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>

-ck