The writecache driver does not handle asynchronous pmem. Reject it when supplied as cache. Link: https://lore.kernel.org/linux-nvdimm/87lfk5hahc.fsf@xxxxxxxxxxxxx/ Fixes: 6e84200c0a29 ("virtio-pmem: Add virtio pmem driver") Signed-off-by: Michal Suchanek <msuchanek@xxxxxxx> --- 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..1e4f37249e28 100644 --- a/drivers/md/dm-writecache.c +++ b/drivers/md/dm-writecache.c @@ -2271,6 +2271,12 @@ static int writecache_ctr(struct dm_target *ti, unsigned argc, char **argv) ti->error = "Unable to map persistent memory for cache"; goto bad; } + + if (!dax_synchronous(wc->ssd_dev->dax_dev)) { + r = -EOPNOTSUPP; + ti->error = "Asynchronous persistent memory not supported as pmem cache"; + goto bad; + } } else { size_t n_blocks, n_metadata_blocks; uint64_t n_bitmap_bits; -- 2.26.2 -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel