nvme: Revert: Fix controller creation races with teardown flow
The indicated patch introduced a barrier in the sysfs_delete attribute for the controller that rejects the request if the controller isn't created. "Created" is defined as at least 1 call to nvme_start_ctrl(). This is problematic in error-injection testing. If an error occurs on the initial attempt to create an association and the controller enters reconnect(s) attempts, the admin cannot delete the controller until either there is a successful association created or ctrl_loss_tmo times out. Where this issue is particularly hurtful is when the "admin" is the nvme-cli, it is performing a connection to a discovery controller, and it is initiated via auto-connect scripts. With the FC transport, if the first connection attempt fails, the controller enters a normal reconnect state but returns control to the cli thread that created the controller. In this scenario, the cli attempts to read the discovery log via ioctl, which fails, causing the cli to see it as an empty log and then proceeds to delete the discovery controller. The delete is rejected and the controller is left live. If the discovery controller reconnect then succeeds, there is no action to delete it, and it sits live doing nothing. Cc: <stable@vger.kernel.org> # v5.7+ Fixes: ce151813 ("nvme: Fix controller creation races with teardown flow") Signed-off-by: James Smart <james.smart@broadcom.com> CC: Israel Rukshin <israelr@mellanox.com> CC: Max Gurtovoy <maxg@mellanox.com> CC: Christoph Hellwig <hch@lst.de> CC: Keith Busch <kbusch@kernel.org> CC: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Christoph Hellwig <hch@lst.de>
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