[PATCHv4 0/5] nvme-fc: FPIN link integrity handling

[Hannes Reinecke <hare@kernel.org>]

FPIN LI (link integrity) messages are received when the attached
fabric detects hardware errors. In response to these messages I/O
should be directed away from the affected ports, and only used
if the 'optimized' paths are unavailable.
Upon port reset the paths should be put back in service as the
affected hardware might have been replaced.
This patch adds a new controller flag 'NVME_CTRL_MARGINAL'
which will be checked during multipath path selection, causing the
path to be skipped when checking for 'optimized' paths. If no
optimized paths are available the 'marginal' paths are considered
for path selection alongside the 'non-optimized' paths.
It also introduces a new nvme-fc callback 'nvme_fc_fpin_rcv()' to
evaluate the FPIN LI TLV payload and set the 'marginal' state on
all affected rports.

Changes to the original submission:
- Changed flag name to 'marginal'
- Do not block marginal path; influence path selection instead
  to de-prioritize marginal paths

Changes to v2:
- Split off driver-specific modifications
- Introduce 'union fc_tlv_desc' to avoid casts

Changes to v3:
- Include reviews from Justin Tee
- Split marginal path handling patch

Hannes Reinecke (5):
  fc_els: use 'union fc_tlv_desc'
  nvme-fc: marginal path handling
  nvme-fc: nvme_fc_fpin_rcv() callback
  lpfc: enable FPIN notification for NVMe
  qla2xxx: enable FPIN notification for NVMe

 drivers/nvme/host/core.c         |   1 +
 drivers/nvme/host/fc.c           |  99 +++++++++++++++++++
 drivers/nvme/host/multipath.c    |  17 ++--
 drivers/nvme/host/nvme.h         |   6 ++
 drivers/scsi/lpfc/lpfc_els.c     |  84 ++++++++--------
 drivers/scsi/qla2xxx/qla_isr.c   |   3 +
 drivers/scsi/scsi_transport_fc.c |  27 +++--
 include/linux/nvme-fc-driver.h   |   3 +
 include/uapi/scsi/fc/fc_els.h    | 165 +++++++++++++++++--------------
 9 files changed, 266 insertions(+), 139 deletions(-)

-- 
2.35.3