For TCP we can set BDI_CAP_STABLE_WRITES. For RDMA I don't think
that
is a good idea as pretty much all RDMA block drivers rely on the
DMA behavior above. The answer is to bounce buffer the data in
SoftiWARP / SoftRoCE.
We already do, see nvme_alloc_ns.
Krishna was getting the issue when testing TCP/NVMeF with -G
during connect. That enables data digest and STABLE_WRITES
I think. So to me it seems we don't get stable pages, but
pages which are touched after handover to the provider.
Non of the transports modifies the data at any point, both will
scan it to compute crc. So surely this is coming from the fs,
Krishna does this happen with xfs as well?
