blktests failures with v6.7-rc1 kernel

[Shinichiro Kawasaki]

Hi all,

I ran the latest blktests (git hash: a20c4de2306e) with the v6.7 kernel.
I observed four failures below, which have been known for months.

As for the two other failures observed with the v6.7-rc1 kernel [1], they are no
longer observed with the v6.7 kernel and the latest blktests. Good.

[1] https://lore.kernel.org/linux-block/ytcn437kppvuj6pwokthrh45asmupbbmbp5ybf56yipo4tukv2@g3qau7lqoooj/


List of failures
================
#1: block/011
#2: nvme/003 (fabrics transport)
#3: nvme/* (fc transport)
#4: srp/002, 011 (rdma_rxe driver)

Failure description
===================

#1: block/011

   The test case fails with NVME devices due to lockdep WARNING "possible
   circular locking dependency detected". Reported in Sep/2022 [2]. In LSF
   2023, it was noted that this failure should be fixed. A RFC fix patch was
   posted recently [3]. It still needs more discussion to be fixed.

   [2] https://lore.kernel.org/linux-block/20220930001943.zdbvolc3gkekfmcv@shindev/
   [3] https://lore.kernel.org/linux-nvme/20231213051704.783490-1-shinichiro.kawasaki@wdc.com/

   This test case caused the following test cases to fail occasionally. A recent
   blktests commit 1e6721b87d5e ("block/011: recover test target devices to
   online or live status") fixed it.

#2: nvme/003 (fabrics transport)

   When the nvme test group is run with trtype=rdma or tcp, the test case fails
   due to lockdep WARNING "possible circular locking dependency detected".
   Reported in May/2023. Hannes provided a kernel fix patch [4] (thanks!). It is
   expected to be upstreamed with kernel v6.8-rc1.

   [4] https://lore.kernel.org/linux-nvme/20231208125321.165819-1-hare@kernel.org/

#3: nvme/* (fc transport)

   With the trtype=fc configuration, tests run on the nvme test group hang.
   Daniel is driving fix work.

#4: srp/002, 011 (rdma_rxe driver)

   Test process hang is observed occasionally. Reported to the relevant mailing
   lists in Aug/2023 [5]. Blktests was modified to change the default driver
   from rdma_rxe to siw to avoid impacts on blktests users. The root cause is
   not yet understood.

   [5] https://lore.kernel.org/linux-rdma/18a3ae8c-145b-4c7f-a8f5-67840feeb98c@acm.org/T/#mee9882c2cfd0cfff33caa04e75418576f4c7a789