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>
> ---
> 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..57b0a972f6fd 100644
> --- a/drivers/md/dm-writecache.c
> +++ b/drivers/md/dm-writecache.c
> @@ -2277,6 +2277,12 @@ static int writecache_ctr(struct dm_target *ti,
> unsigned argc, char **argv)
>
> wc->memory_map_size -= (uint64_t)wc->start_sector <<
> SECTOR_SHIFT;
>
> + if (!dax_synchronous(wc->ssd_dev->dax_dev)) {
> + r = -EOPNOTSUPP;
> + ti->error = "Asynchronous persistent memory not
> supported as pmem cache";
> + goto bad;
> + }
> +
> bio_list_init(&wc->flush_list);
> wc->flush_thread = kthread_create(writecache_flush_thread, wc,
> "dm_writecache_flush");
> if (IS_ERR(wc->flush_thread)) {
> --
Hi
Shouldn't this be in the "if (WC_MODE_PMEM(wc))" block?
WC_MODE_PMEM(wc) retrurns true if we are using persistent memory as a
cache device, otherwise we are using generic block device as a cache
device.
Mikulas
