This patch fixes a long-standing bug that initialized the FC-NVME
cmnd iu CSN value to 1. Early FC-NVME specs had the connection starting
with CSN=1. By the time the spec reached approval, the language had
changed to state a connection should start with CSN=0.  This patch
corrects the initialization value for FC-NVME connections.

Additionally, in reviewing the transport, the CSN value is assigned to
the new IU early in the start routine. It's possible that a later dma
map request may fail, causing the command to never be sent to the
controller.  Change the location of the assignment so that it is
immediately prior to calling the lldd. Add a comment block to explain
the impacts if the lldd were to additionally fail sending the command.

Signed-off-by: Dick Kennedy <dick.kennedy@broadcom.com>
Signed-off-by: James Smart <jsmart2021@gmail.com>
Reviewed-by: Ewan D. Milne <emilne@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvme_cancel_request() is used in error handler, and it is always
reliable to cancel request synchronously, and avoids possible race
in which request may be completed after real hw queue is destroyed.

One issue is reported by our customer on NVMe RDMA, in which freed ib
queue pair may be used in nvme_rdma_complete_rq().

Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: James Smart <james.smart@broadcom.com>
Cc: linux-nvme@lists.infradead.org
Reviewed-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

When undergoing state transitions I/O might be requeued, hence
we should always call nvme_mpath_set_live() to schedule requeue_work
whenever the nvme device is live, independent on whether the
old state was live or not.

Signed-off-by: Martin George <marting@netapp.com>
Signed-off-by: Gargi Srinivas <sring@netapp.com>
Signed-off-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvme_tcp_end_request just takes the status value and the converts
it to little endian as well as shifting for the phase bit.

Fixes: 43ce38a6d823 ("nvme-tcp: support C2HData with SUCCESS flag")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>

Pull more block layer changes from Jens Axboe:
 "This is a collection of both stragglers, and fixes that came in after
  I finalized the initial pull. This contains:

   - An MD pull request from Song, with a few minor fixes

   - Set of NVMe patches via Christoph

   - Pull request from Konrad, with a few fixes for xen/blkback

   - pblk fix IO calculation fix (Javier)

   - Segment calculation fix for pass-through (Ming)

   - Fallthrough annotation for blkcg (Mathieu)"

* tag 'for-5.1/block-post-20190315' of git://git.kernel.dk/linux-block: (25 commits)
  blkcg: annotate implicit fall through
  nvme-tcp: support C2HData with SUCCESS flag
  nvmet: ignore EOPNOTSUPP for discard
  nvme: add proper write zeroes setup for the multipath device
  nvme: add proper discard setup for the multipath device
  nvme: remove nvme_ns_config_oncs
  nvme: disable Write Zeroes for qemu controllers
  nvmet-fc: bring Disconnect into compliance with FC-NVME spec
  nvmet-fc: fix issues with targetport assoc_list list walking
  nvme-fc: reject reconnect if io queue count is reduced to zero
  nvme-fc: fix numa_node when dev is null
  nvme-fc: use nr_phys_segments to determine existence of sgl
  nvme-loop: init nvmet_ctrl fatal_err_work when allocate
  nvme: update comment to make the code easier to read
  nvme: put ns_head ref if namespace fails allocation
  nvme-trace: fix cdw10 buffer overrun
  nvme: don't warn on block content change effects
  nvme: add get-feature to admin cmds tracer
  md: Fix failed allocation of md_register_thread
  It's wrong to add len to sector_nr in raid10 reshape twice
  ...

A C2HData PDU with the SUCCESS flag set indicates that the I/O was
completed by the controller successfully and means that a subsequent
completion response capsule PDU will be ommitted.

If we see this flag, fisrt we check that LAST_PDU flag is set as well,
and then we complete the request when the data transfer (and data digest
verification if its on) is done.

While we're at it, reuse a bit of code with nvme_fail_request.

Reported-by: Steve Blightman <steve.blightman@oracle.com>
Suggested-by: Oliver Smith-Denny <osmithde@cisco.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Oliver Smith-Denny <osmithde@cisco.com>
Tested-by: Oliver Smith-Denny <osmithde@cisco.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Add a gendisk argument to nvme_config_write_zeroes so that the call to
nvme_update_disk_info for the multipath device node updates the
proper request_queue.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Tested-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Add a gendisk argument to nvme_config_discard so that the call to
nvme_update_disk_info for the multipath device node updates the
proper request_queue.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reported-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Tested-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Just opencode the two function calls in the caller.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Tested-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Qemu started out with a broken implementation of Write Zeroes written
by yours truly.  Disable Write Zeroes on qemu for now, eventually
we need to go back and make all the qemu quirks version specific,
but that is left for another time.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Tested-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>