Comments are clarified to note how transport data structures are
protected.
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
---
net/sunrpc/xprtrdma/verbs.c | 14 ++++++++++----
1 file changed, 10 insertions(+), 4 deletions(-)
diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c
index 7749a2b..94af069 100644
--- a/net/sunrpc/xprtrdma/verbs.c
+++ b/net/sunrpc/xprtrdma/verbs.c
@@ -402,8 +402,7 @@ static void rpcrdma_xprt_drain(struct rpcrdma_xprt *r_xprt)
* rpcrdma_ia_remove - Handle device driver unload
* @ia: interface adapter being removed
*
- * Divest transport H/W resources associated with this adapter,
- * but allow it to be restored later.
+ * Callers must serialize calls to this function.
*/
void
rpcrdma_ia_remove(struct rpcrdma_ia *ia)
@@ -434,16 +433,23 @@ static void rpcrdma_xprt_drain(struct rpcrdma_xprt *r_xprt)
ib_free_cq(ep->rep_attr.send_cq);
ep->rep_attr.send_cq = NULL;
- /* The ULP is responsible for ensuring all DMA
- * mappings and MRs are gone.
+ /* The ib_drain_qp above guarantees that all posted
+ * Receives have flushed, which returns the transport's
+ * rpcrdma_reps to the rb_recv_bufs list.
*/
list_for_each_entry(rep, &buf->rb_recv_bufs, rr_list)
rpcrdma_dma_unmap_regbuf(rep->rr_rdmabuf);
+
+ /* DMA mapping happens in ->send_request with the
+ * transport send lock held. Our caller is holding
+ * the transport send lock.
+ */
list_for_each_entry(req, &buf->rb_allreqs, rl_all) {
rpcrdma_dma_unmap_regbuf(req->rl_rdmabuf);
rpcrdma_dma_unmap_regbuf(req->rl_sendbuf);
rpcrdma_dma_unmap_regbuf(req->rl_recvbuf);
}
+
rpcrdma_mrs_destroy(buf);
ib_dealloc_pd(ia->ri_pd);
ia->ri_pd = NULL;
