nvdimm: preserve flush callback -ENOMEM

nvdimm_flush() maps provider flush failures to -EIO. Keep that default
because provider callbacks can report host-side or backend failures that
should remain generic I/O errors to the guest.

Guest-side allocation failures should not be reported as I/O errors. In the
virtio-pmem path, the flush request allocation can fail with -ENOMEM before
any request is submitted to the host. Mapping that to -EIO makes resource
pressure look like media failure.

Preserve -ENOMEM from provider callbacks and continue to map other non-zero
provider failures to -EIO. The generic flush path still returns 0, and
pmem_submit_bio() already converts errno values to block status for bio
completion.

Suggested-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Signed-off-by: Li Chen <me@linux.beauty>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Message-ID: <20260630092338.2094628-2-me@linux.beauty>

0 files changed, 0 insertions, 0 deletions