linux.git/drivers/nvme/target/loop.c, branch v4.18

nvme: if_ready checks to fail io to deleting controller

2018-07-24T11:44:40+00:00

The revised if_ready checks skipped over the case of returning error when
the controller is being deleted.  Instead it was returning BUSY, which
caused the ios to retry, which caused the ns delete to hang waiting for
the ios to drain.

Stack trace of hang looks like:
 kworker/u64:2   D    0    74      2 0x80000000
 Workqueue: nvme-delete-wq nvme_delete_ctrl_work [nvme_core]
 Call Trace:
  ? __schedule+0x26d/0x820
  schedule+0x32/0x80
  blk_mq_freeze_queue_wait+0x36/0x80
  ? remove_wait_queue+0x60/0x60
  blk_cleanup_queue+0x72/0x160
  nvme_ns_remove+0x106/0x140 [nvme_core]
  nvme_remove_namespaces+0x7e/0xa0 [nvme_core]
  nvme_delete_ctrl_work+0x4d/0x80 [nvme_core]
  process_one_work+0x160/0x350
  worker_thread+0x1c3/0x3d0
  kthread+0xf5/0x130
  ? process_one_work+0x350/0x350
  ? kthread_bind+0x10/0x10
  ret_from_fork+0x1f/0x30

Extend nvmf_fail_nonready_command() to supply the controller pointer so
that the controller state can be looked at. Fail any io to a controller
that is deleting.

Fixes: 3bc32bb1186c ("nvme-fabrics: refactor queue ready check")
Fixes: 35897b920c8a ("nvme-fabrics: fix and refine state checks in __nvmf_check_ready")
Signed-off-by: James Smart 
Signed-off-by: Christoph Hellwig 
Tested-by: Ewan D. Milne 
Reviewed-by: Ewan D. Milne

nvme-fabrics: refactor queue ready check

2018-06-15T09:21:00+00:00

Move the is_connected check to the fibre channel transport, as it has no
meaning for other transports.  To facilitate this split out a new
nvmf_fail_nonready_command helper that is called by the transport when
it is asked to handle a command on a queue that is not ready.

Also avoid a function call for the queue live fast path by inlining
the check.

Signed-off-by: Christoph Hellwig 
Reviewed-by: James Smart

nvme-loop: add support for multiple ports

2018-05-30T06:05:18+00:00

This is useful at least for multipath testing.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Johannes Thumshirn

Merge branch 'nvme-4.18-2' of git://git.infradead.org/nvme into for-4.18/block

2018-05-29T18:56:20+00:00

Pull NVMe changes from Christoph:

"Here is the current batch of nvme updates for 4.18, we have a few more
 patches in the queue, but I'd like to get this pile into your tree
 and linux-next ASAP.

 The biggest item is support for file-backed namespaces in the NVMe
 target from Chaitanya, in addition to that we mostly small fixes from
 all the usual suspects."

* 'nvme-4.18-2' of git://git.infradead.org/nvme:
  nvme: fixup memory leak in nvme_init_identify()
  nvme: fix KASAN warning when parsing host nqn
  nvmet-loop: use nr_phys_segments when map rq to sgl
  nvmet-fc: increase LS buffer count per fc port
  nvmet: add simple file backed ns support
  nvmet: remove duplicate NULL initialization for req->ns
  nvmet: make a few error messages more generic
  nvme-fabrics: allow duplicate connections to the discovery controller
  nvme-fabrics: centralize discovery controller defaults
  nvme-fabrics: remove unnecessary controller subnqn validation
  nvme-fc: remove setting DNR on exception conditions
  nvme-rdma: stop admin queue before freeing it
  nvme-pci: Fix AER reset handling
  nvme-pci: set nvmeq->cq_vector after alloc cq/sq
  nvme: host: core: fix precedence of ternary operator
  nvme: fix lockdep warning in nvme_mpath_clear_current_path

nvme: return BLK_EH_DONE from ->timeout

2018-05-29T14:59:21+00:00

NVMe always completes the request before returning from ->timeout, either
by polling for it, or by disabling the controller.  Return BLK_EH_DONE so
that the block layer doesn't even try to complete it again.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Hannes Reinecke 
Reviewed-by: Johannes Thumshirn 
Signed-off-by: Jens Axboe

nvmet-loop: use nr_phys_segments when map rq to sgl

2018-05-25T14:50:12+00:00

Use blk_rq_nr_phys_segments() instead of blk_rq_payload_bytes() to check
if a command contains data to me mapped.  This fixes the case where
a struct requests contains LBAs, but no data will actually be send,
e.g. the pending Write Zeroes support.

Signed-off-by: Chaitanya Kulkarni 
Signed-off-by: Christoph Hellwig

nvmet: switch loopback target state to connecting when resetting

2018-05-03T15:37:50+00:00

After commit bb06ec31452f ("nvme: expand nvmf_check_if_ready checks")
resetting of the loopback nvme target failed as we forgot to switch
it's state to NVME_CTRL_CONNECTING before we reconnect the admin
queues. Therefore the checks in nvmf_check_if_ready() choose to go to
the reject_io case and thus we couldn't sent out an identify
controller command to reconnect.

Change the controller state to NVME_CTRL_CONNECTING after tearing down
the old connection and before re-establishing the connection.

Fixes: bb06ec31452f ("nvme: expand nvmf_check_if_ready checks")
Signed-off-by: Johannes Thumshirn 
Signed-off-by: Keith Busch 
Signed-off-by: Jens Axboe

nvme: expand nvmf_check_if_ready checks

2018-04-12T15:58:27+00:00

The nvmf_check_if_ready() checks that were added are very simplistic.
As such, the routine allows a lot of cases to fail ios during windows
of reset or re-connection. In cases where there are not multi-path
options present, the error goes back to the callee - the filesystem
or application. Not good.

The common routine was rewritten and calling syntax slightly expanded
so that per-transport is_ready routines don't need to be present.
The transports now call the routine directly. The routine is now a
fabrics routine rather than an inline function.

The routine now looks at controller state to decide the action to
take. Some states mandate io failure. Others define the condition where
a command can be accepted.  When the decision is unclear, a generic
queue-or-reject check is made to look for failfast or multipath ios and
only fails the io if it is so marked. Otherwise, the io will be queued
and wait for the controller state to resolve.

Admin commands issued via ioctl share a live admin queue with commands
from the transport for controller init. The ioctls could be intermixed
with the initialization commands. It's possible for the ioctl cmd to
be issued prior to the controller being enabled. To block this, the
ioctl admin commands need to be distinguished from admin commands used
for controller init. Added a USERCMD nvme_req(req)->rq_flags bit to
reflect this division and set it on ioctls requests.  As the
nvmf_check_if_ready() routine is called prior to nvme_setup_cmd(),
ensure that commands allocated by the ioctl path (actually anything
in core.c) preps the nvme_req(req) before starting the io. This will
preserve the USERCMD flag during execution and/or retry.

Signed-off-by: James Smart 
Reviewed-by: Sagi Grimberg 
Reviewed-by: Johannes Thumshirn 
Signed-off-by: Keith Busch 
Signed-off-by: Jens Axboe

nvme-loop: fix kernel oops in case of unhandled command

2018-04-12T15:58:27+00:00

When nvmet_req_init() fails, __nvmet_req_complete() is called
to handle the target request via .queue_response(), so
nvme_loop_queue_response() shouldn't be called again for
handling the failure.

This patch fixes this case by the following way:

- move blk_mq_start_request() before nvmet_req_init(), so
nvme_loop_queue_response() may work well to complete this
host request

- don't call nvme_cleanup_cmd() which is done in nvme_loop_complete_rq()

- don't call nvme_loop_queue_response() which is done via
.queue_response()

Signed-off-by: Ming Lei 
Reviewed-by: Christoph Hellwig 
[trimmed changelog]
Signed-off-by: Keith Busch 
Signed-off-by: Jens Axboe

nvmet: constify struct nvmet_fabrics_ops

2018-03-26T14:53:43+00:00

Signed-off-by: Christoph Hellwig 
Signed-off-by: Keith Busch 
Signed-off-by: Jens Axboe