[PATCHv2 0/2] nvme: fixup MD RAID usage

[Minwoo Im]

On 21-02-25 12:05:32, Hannes Reinecke wrote:
> Hi all,
> 
> ever since the implementation NVMe-oF does not work together with MD RAID.
> MD RAID expects the device to return an I/O error on failure, and to remove
> the block device if the underlying hardware is removed.
> This is contrary to the implementation of NVMe-oF, which will keep on retrying
> I/O while the controller is being reset, and will only remove the block device
> once the last _user_ is gone.
> 
> While we already have a 'fast_io_fail_tmo' setting which would ensure
> that I/O errors are returned after the timeout expired, this attribute
> has to be set during the initial 'connect' call.
> So the first patch adds a 'fasi_io_fail_tmo' controller sysfs
> attribute which allows the admin to modify it during runtime.
> To fixup the second issue a new attribute 'no_path_detach' is
> implemented, which will cause the disk to be removed as once the
> last controller holding a path to the namespace is removed (ie after
> all reconnect attempts for that controllers are exhausted).
> 
> This is a rework of the earlier path by Keith Busch ('nvme-mpath: delete disk
> after last connection'). Kudos to him for suggesting this approach.
> 
> Changes to v1:
> - Integrated reviews from Sagi
> - Use fast_io_fail_tmo instead of a new sysfs attribute
> - Rename attribute to 'no_path_detach'
> 
> Hannes Reinecke (2):
>   nvme: add 'fast_io_fail_tmo' controller sysfs attribute
>   nvme: delete disk when last path is gone
> 
>  drivers/nvme/host/core.c      | 41 ++++++++++++++++++++++++++++++++++-
>  drivers/nvme/host/multipath.c | 31 +++++++++++++++++++++++++-
>  drivers/nvme/host/nvme.h      | 21 +++++++++++++++---
>  3 files changed, 88 insertions(+), 5 deletions(-)

Looks good to me.

Reviewed-by: Minwoo Im <minwoo.im.dev at gmail.com>