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From: Daniel Wagner <dwagner@suse.de>
To: James Smart <james.smart@broadcom.com>
Cc: Keith Busch <kbusch@kernel.org>,
	Christoph Hellwig <hch@lst.de>,
	Sagi Grimberg <sagi@grimberg.me>,
	Hannes Reinecke <hare@suse.de>,
	linux-nvme@lists.infradead.org,
	linux-kernel@vger.kernel.org,
	Daniel Wagner <dwagner@suse.de>
Subject: [PATCH v0 0/6] nvme-fc: fix blktests nvme/041
Date: Fri, 16 Feb 2024 09:45:20 +0100
Message-ID: <20240216084526.14133-1-dwagner@suse.de>
Precedence: bulk
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After the target side is working with blktests and blktest is also able
to deal with the FC transport, it's time to address the fallouts on the host
side. As first step, let's fix the failing nvme/041 tests.

As we arleady discussed, the main issue here is that FC transport is deferring
the connect attempt to a workqueue. The other fabric transport don't do this.
And all blktests expect that the 'nvme connect' call is synchronous.

Initially, I just added the completion and waited on connect to succeed or fail.
But this triggered a lot of UAFs. After banging my head on this problem for a
while I decided to replace the complete ref counting strategy.

With this new approach all execept nvme/048 are passing and no UAFs or other
troubles observed. I also tested with real hardware (lpfc, qla2xxx), though I
don't have a way to trigger all sorts of transport errors which would be
interesting to see if my patches are breaking anything. 

I think there is still on problem left in the module exit code path. The cleanup
function iterates over the ctrl list storred in the rport object. The delete
code path is not atomic and removes the controller from the list somewhere in
the delete path. Thus this races with the module unload, IMO. we could just
maintain a list of controllers which is protected a lock as we have in tcp/rdma.

Daniel Wagner (6):
  nvme-fabrics: introduce connect_sync option
  nvme-fc: rename free_ctrl callback to match name pattern
  nvme-fc: do not retry when auth fails or connection is refused
  nvme-fabrics: introduce ref counting for nvmf_ctrl_options
  nvme-fc: redesign locking and refcounting
  nvme-fc: wait for connect attempt to finish

 drivers/nvme/host/fabrics.c |  28 +++++-
 drivers/nvme/host/fabrics.h |   9 +-
 drivers/nvme/host/fc.c      | 180 ++++++++++++++++--------------------
 drivers/nvme/host/rdma.c    |  18 +++-
 drivers/nvme/host/tcp.c     |  21 +++--
 drivers/nvme/target/loop.c  |  19 ++--
 6 files changed, 150 insertions(+), 125 deletions(-)

-- 
2.43.0