RDMA/efa: Fix wrong resources deallocation order

When trying to destroy QP or CQ, we first decrease the refcount and
potentially free memory regions allocated for the object and then
request the device to destroy the object. If the device fails, the
object isn't fully destroyed so the user/IB core can try to destroy the
object again which will lead to underflow when trying to decrease an
already zeroed refcount.

Deallocate resources in reverse order of allocating them to safely free
them.

Fixes: ff6629f88c52 ("RDMA/efa: Do not delay freeing of DMA pages")
Reviewed-by: Michael Margolin <mrgolin@amazon.com>
Reviewed-by: Yossi Leybovich <sleybo@amazon.com>
Signed-off-by: Yonatan Nachum <ynachum@amazon.com>
Link: https://lore.kernel.org/r/20230822082725.31719-1-ynachum@amazon.com
Signed-off-by: Leon Romanovsky <leon@kernel.org>

diff --git a/drivers/infiniband/hw/efa/efa_verbs.c b/drivers/infiniband/hw/efa/efa_verbs.c
index 7a27d79c0541f1893dd1350c9d8074e42665c0a7..0f8ca99d0827642db5c08f3301a0f870f657635b 100644 (file)
--- a/drivers/infiniband/hw/efa/efa_verbs.c
+++ b/drivers/infiniband/hw/efa/efa_verbs.c
@@ -453,12 +453,12 @@ int efa_destroy_qp(struct ib_qp *ibqp, struct ib_udata *udata)
 
        ibdev_dbg(&dev->ibdev, "Destroy qp[%u]\n", ibqp->qp_num);
 
-       efa_qp_user_mmap_entries_remove(qp);
-
        err = efa_destroy_qp_handle(dev, qp->qp_handle);
        if (err)
                return err;
 
+       efa_qp_user_mmap_entries_remove(qp);
+
        if (qp->rq_cpu_addr) {
                ibdev_dbg(&dev->ibdev,
                          "qp->cpu_addr[0x%p] freed: size[%lu], dma[%pad]\n",
@@ -1017,8 +1017,8 @@ int efa_destroy_cq(struct ib_cq *ibcq, struct ib_udata *udata)
                  "Destroy cq[%d] virt[0x%p] freed: size[%lu], dma[%pad]\n",
                  cq->cq_idx, cq->cpu_addr, cq->size, &cq->dma_addr);
 
-       efa_cq_user_mmap_entries_remove(cq);
        efa_destroy_cq_idx(dev, cq->cq_idx);
+       efa_cq_user_mmap_entries_remove(cq);
        if (cq->eq) {
                xa_erase(&dev->cqs_xa, cq->cq_idx);
                synchronize_irq(cq->eq->irq.irqn);