linux.git/drivers/nvme/target/loop.c, branch v5.19

nvmet: use a private workqueue instead of the system workqueue

2022-03-29T07:29:04+00:00

Any attempt to flush kernel-global WQs has possibility of deadlock
so we should simply stop using them, instead introduce nvmet_wq
which is the generic nvmet workqueue for work elements that
don't explicitly require a dedicated workqueue (by the mere fact
that they are using the system_wq).

Changes were done using the following replaces:

 - s/schedule_work(/queue_work(nvmet_wq, /g
 - s/schedule_delayed_work(/queue_delayed_work(nvmet_wq, /g
 - s/flush_scheduled_work()/flush_workqueue(nvmet_wq)/g

Reported-by: Tetsuo Handa 
Signed-off-by: Sagi Grimberg 
Reviewed-by: Chaitanya Kulkarni 
Signed-off-by: Christoph Hellwig

nvme: add a helper to initialize connect_q

2022-02-28T11:45:06+00:00

Add and use helper to remove duplicate code for fabrics connect_q
initialization and error handling for all the transports.

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

nvme: loop: clear NVME_CTRL_ADMIN_Q_STOPPED after admin queue is reallocated

2021-10-20T00:27:58+00:00

The nvme-loop's admin queue may be freed and reallocated, and we have to
reset the flag of NVME_CTRL_ADMIN_Q_STOPPED so that the flag can match
with the quiesce state of the admin queue.

nvme-loop is the only driver to reallocate request queue, and not see
such usage in other nvme drivers.

Signed-off-by: Ming Lei 
Reviewed-by: Christoph Hellwig 
Link: https://lore.kernel.org/r/20211014081710.1871747-6-ming.lei@redhat.com
Signed-off-by: Jens Axboe

nvme: apply nvme API to quiesce/unquiesce admin queue

2021-10-20T00:27:58+00:00

Apply the added two APIs to quiesce/unquiesce admin queue.

Signed-off-by: Ming Lei 
Reviewed-by: Christoph Hellwig 
Link: https://lore.kernel.org/r/20211014081710.1871747-3-ming.lei@redhat.com
Signed-off-by: Jens Axboe

nvme: code command_id with a genctr for use-after-free validation

2021-08-16T12:42:22+00:00

We cannot detect a (perhaps buggy) controller that is sending us
a completion for a request that was already completed (for example
sending a completion twice), this phenomenon was seen in the wild
a few times.

So to protect against this, we use the upper 4 msbits of the nvme sqe
command_id to use as a 4-bit generation counter and verify it matches
the existing request generation that is incrementing on every execution.

The 16-bit command_id structure now is constructed by:
| xxxx | xxxxxxxxxxxx |
  gen    request tag

This means that we are giving up some possible queue depth as 12 bits
allow for a maximum queue depth of 4095 instead of 65536, however we
never create such long queues anyways so no real harm done.

Suggested-by: Keith Busch 
Signed-off-by: Sagi Grimberg 
Acked-by: Keith Busch 
Reviewed-by: Hannes Reinecke 
Reviewed-by: Daniel Wagner 
Tested-by: Daniel Wagner 
Signed-off-by: Christoph Hellwig

nvme: use blk_execute_rq() for passthrough commands

2021-06-30T21:35:38+00:00

The generic blk_execute_rq() knows how to handle polled completions. Use
that instead of implementing an nvme specific handler.

Signed-off-by: Keith Busch 
Reviewed-by: Christoph Hellwig 
Reviewed-by: Chaitanya Kulkarni 
Link: https://lore.kernel.org/r/20210610214437.641245-3-kbusch@kernel.org
Signed-off-by: Jens Axboe

nvme-loop: do not warn for deleted controllers during reset

2021-06-02T07:06:53+00:00

During concurrent reset and delete calls the reset workqueue is
flushed, causing nvme_loop_reset_ctrl_work() to be executed when
the controller is in state DELETING or DELETING_NOIO.
But this is expected, so we shouldn't issue a WARN_ON here.

Signed-off-by: Hannes Reinecke 
Signed-off-by: Christoph Hellwig

nvme-loop: check for NVME_LOOP_Q_LIVE in nvme_loop_destroy_admin_queue()

2021-06-02T07:06:53+00:00

We need to check the NVME_LOOP_Q_LIVE flag in
nvme_loop_destroy_admin_queue() to protect against duplicate
invocations eg during concurrent reset and remove calls.

Signed-off-by: Hannes Reinecke 
Reviewed-by: Chaitanya Kulkarni 
Signed-off-by: Christoph Hellwig

nvme-loop: clear NVME_LOOP_Q_LIVE when nvme_loop_configure_admin_queue() fails

2021-06-02T07:06:53+00:00

When the call to nvme_enable_ctrl() in nvme_loop_configure_admin_queue()
fails the NVME_LOOP_Q_LIVE flag is not cleared.

Signed-off-by: Hannes Reinecke 
Reviewed-by: Chaitanya Kulkarni 
Signed-off-by: Christoph Hellwig

nvme-loop: reset queue count to 1 in nvme_loop_destroy_io_queues()

2021-06-02T07:06:53+00:00

The queue count is increased in nvme_loop_init_io_queues(), so we
need to reset it to 1 at the end of nvme_loop_destroy_io_queues().
Otherwise the function is not re-entrant safe, and crash will happen
during concurrent reset and remove calls.

Signed-off-by: Hannes Reinecke 
Reviewed-by: Chaitanya Kulkarni 
Signed-off-by: Christoph Hellwig