On Tue, 30 Jun 2020, Michal Suchanek wrote:
> The writecache driver does not handle asynchronous pmem. Reject it when
> supplied as cache.
>
> Link: https://lore.kernel.org/linux-nvdimm/87lfk5hahc....@linux.ibm.com/
> Fixes: 6e84200c0a29 ("virtio-pmem: Add virtio pmem driver")
>
> Signed-off-by: Michal Suchanek <msucha...@suse.de>
Acked-by: Mikulas Patocka <mpato...@redhat.com>
> ---
> drivers/md/dm-writecache.c | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/drivers/md/dm-writecache.c b/drivers/md/dm-writecache.c
> index 30505d70f423..5358894bb9fd 100644
> --- a/drivers/md/dm-writecache.c
> +++ b/drivers/md/dm-writecache.c
> @@ -2266,6 +2266,12 @@ static int writecache_ctr(struct dm_target *ti,
> unsigned argc, char **argv)
> }
>
> if (WC_MODE_PMEM(wc)) {
> + if (!dax_synchronous(wc->ssd_dev->dax_dev)) {
> + r = -EOPNOTSUPP;
> + ti->error = "Asynchronous persistent memory not
> supported as pmem cache";
> + goto bad;
> + }
> +
> r = persistent_memory_claim(wc);
> if (r) {
> ti->error = "Unable to map persistent memory for cache";
> --
> 2.26.2
>
