[SPDK] SPDK NVMe/TCP target cannot disconnect for keep alive timeout if build with "--with-uring"

Hi,

While running SPDK NVMe/TCP target which is built with “—with-uring” option, if shutting down host without disconnecting controllers, target side gets keep alive timeout. In response to keep alive timeout, target should terminate any connections and destroy the controller instances. But below log messages show this not happening.

When this happens, if I press “Ctrl-C”, the target process does not exit. To terminate the target process, I have to run “kill -9 <pid>” from another ssh session to kill the process.

When using posix socket implementation, this problem does not happen, the nvmf_tgt  can always exit when pressing “Ctrl-C”.

Starting SPDK v20.07 git sha1 1a527e501 / DPDK 20.05.0 initialization...
[ DPDK EAL parameters: nvmf --no-shconf -c 0x3f --log-level=lib.eal:6 --log-level=lib.cryptodev:5 --log-level=user1:6 --iova-mode=pa --base-virtaddr=0x200000000000 --match-allocations --file-prefix=spdk_pid1253923 ]
EAL: No available hugepages reported in hugepages-1048576kB
EAL: VFIO support initialized
EAL: No legacy callbacks, legacy socket not created
[2020-08-30 21:05:09.498321] app.c: 666:spdk_app_start: *NOTICE*: Total cores available: 6
[2020-08-30 21:05:09.692271] reactor.c: 371:reactor_run: *NOTICE*: Reactor started on core 1
[2020-08-30 21:05:09.692833] reactor.c: 371:reactor_run: *NOTICE*: Reactor started on core 2
[2020-08-30 21:05:09.693361] reactor.c: 371:reactor_run: *NOTICE*: Reactor started on core 3
[2020-08-30 21:05:09.694206] reactor.c: 371:reactor_run: *NOTICE*: Reactor started on core 4
[2020-08-30 21:05:09.694754] reactor.c: 371:reactor_run: *NOTICE*: Reactor started on core 5
[2020-08-30 21:05:09.695259] reactor.c: 371:reactor_run: *NOTICE*: Reactor started on core 0
[2020-08-30 21:05:09.695340] accel_engine.c: 509:spdk_accel_engine_initialize: *NOTICE*: Accel engine initialized to use software engine.
[2020-08-30 21:06:27.605442] nvmf_rpc.c:1585:nvmf_rpc_decode_max_qpairs: *WARNING*: Parameter max_qpairs_per_ctrlr is deprecated, use max_io_qpairs_per_ctrlr instead.
[2020-08-30 21:06:27.605570] nvmf_rpc.c:1585:nvmf_rpc_decode_max_qpairs: *WARNING*: Parameter max_qpairs_per_ctrlr is deprecated, use max_io_qpairs_per_ctrlr instead.
[2020-08-30 21:06:27.605595] tcp.c: 469:nvmf_tcp_create: *NOTICE*: *** TCP Transport Init ***
[2020-08-30 21:06:27.653656] tcp.c: 650:nvmf_tcp_listen: *NOTICE*: *** NVMe/TCP Target Listening on 192.168.30.150 port 4420 ***
[2020-08-31 05:24:04.951614] ctrlr.c: 166:nvmf_ctrlr_keep_alive_poll: *NOTICE*: Disconnecting host from subsystem nqn.2020-04.com.vmware.eng:tgt1 due to keep alive timeout.
[2020-08-31 05:24:04.951891] ctrlr.c: 166:nvmf_ctrlr_keep_alive_poll: *NOTICE*: Disconnecting host from subsystem nqn.2020-04.com.vmware.eng:tgt2 due to keep alive timeout.
[2020-08-31 05:24:34.951857] ctrlr.c: 166:nvmf_ctrlr_keep_alive_poll: *NOTICE*: Disconnecting host from subsystem nqn.2020-04.com.vmware.eng:tgt1 due to keep alive timeout.
[2020-08-31 05:24:34.952134] ctrlr.c: 166:nvmf_ctrlr_keep_alive_poll: *NOTICE*: Disconnecting host from subsystem nqn.2020-04.com.vmware.eng:tgt2 due to keep alive timeout.
[2020-08-31 05:25:04.952101] ctrlr.c: 166:nvmf_ctrlr_keep_alive_poll: *NOTICE*: Disconnecting host from subsystem nqn.2020-04.com.vmware.eng:tgt1 due to keep alive timeout.
[2020-08-31 05:25:04.952378] ctrlr.c: 166:nvmf_ctrlr_keep_alive_poll: *NOTICE*: Disconnecting host from subsystem nqn.2020-04.com.vmware.eng:tgt2 due to keep alive timeout.
[2020-08-31 05:25:34.952344] ctrlr.c: 166:nvmf_ctrlr_keep_alive_poll: *NOTICE*: Disconnecting host from subsystem nqn.2020-04.com.vmware.eng:tgt1 due to keep alive timeout.
[2020-08-31 05:25:34.952621] ctrlr.c: 166:nvmf_ctrlr_keep_alive_poll: *NOTICE*: Disconnecting host from subsystem nqn.2020-04.com.vmware.eng:tgt2 due to keep alive timeout.
[2020-08-31 05:26:04.952588] ctrlr.c: 166:nvmf_ctrlr_keep_alive_poll: *NOTICE*: Disconnecting host from subsystem nqn.2020-04.com.vmware.eng:tgt1 due to keep alive timeout.
[2020-08-31 05:26:04.952864] ctrlr.c: 166:nvmf_ctrlr_keep_alive_poll: *NOTICE*: Disconnecting host from subsystem nqn.2020-04.com.vmware.eng:tgt2 due to keep alive timeout.
[2020-08-31 05:26:34.952830] ctrlr.c: 166:nvmf_ctrlr_keep_alive_poll: *NOTICE*: Disconnecting host from subsystem nqn.2020-04.com.vmware.eng:tgt1 due to keep alive timeout.
[2020-08-31 05:26:34.953107] ctrlr.c: 166:nvmf_ctrlr_keep_alive_poll: *NOTICE*: Disconnecting host from subsystem nqn.2020-04.com.vmware.eng:tgt2 due to keep alive timeout.

Thanks,
-Wenhua