This commit fixes a race condition when calling free_ctrlr(),
nvmf_vfio_user_close_qpair->free_qp will set controller `ctrlr->qp[qid] = NULL`
finally, when calling free_ctrlr() we also need to check `ctrlr->qp[qid]`
is NULL or not, when there are multiple IO queues, we need a lock to protect
`ctrlr->qp[qid]`. However, the call to free_qp() in free_ctrlr() is valid
only when killing SPDK target, for all other cases, e.g: VM disconnected,
the queue pairs are already freed, so here we can process these different
cases separately, and avoid extra lock.
Change-Id: I7ab71f08bf4d737843b2af42e27b1571be0b45e9
Signed-off-by: Changpeng Liu <changpeng.liu@intel.com>
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/9351
Community-CI: Mellanox Build Bot
Community-CI: Broadcom CI <spdk-ci.pdl@broadcom.com>
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Thanos Makatos <thanos.makatos@nutanix.com>