On 3/31/2021 3:36 PM, Chuck Lever wrote:
Defer destruction of an rpcrdma_rep until transport tear-down to
avoid races between Receive completion and rpcrdma_reps_unmap().
This seems sketchy, but it's a good approach to destroy in one
place, and off the hot path. You might restate the description
in a positive way, not strictly to avoid a race.
Reviewed-By: Tom Talpey <tom@xxxxxxxxxx>
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
---
net/sunrpc/xprtrdma/verbs.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c
index 1d88685badbe..92af272f9cc9 100644
--- a/net/sunrpc/xprtrdma/verbs.c
+++ b/net/sunrpc/xprtrdma/verbs.c
@@ -80,6 +80,8 @@ static void rpcrdma_sendctx_put_locked(struct rpcrdma_xprt *r_xprt,
struct rpcrdma_sendctx *sc);
static int rpcrdma_reqs_setup(struct rpcrdma_xprt *r_xprt);
static void rpcrdma_reqs_reset(struct rpcrdma_xprt *r_xprt);
+static void rpcrdma_rep_put(struct rpcrdma_buffer *buf,
+ struct rpcrdma_rep *rep);
static void rpcrdma_rep_destroy(struct rpcrdma_rep *rep);
static void rpcrdma_reps_unmap(struct rpcrdma_xprt *r_xprt);
static void rpcrdma_mrs_create(struct rpcrdma_xprt *r_xprt);
@@ -205,7 +207,7 @@ static void rpcrdma_wc_receive(struct ib_cq *cq, struct ib_wc *wc)
out_flushed:
rpcrdma_flush_disconnect(r_xprt, wc);
- rpcrdma_rep_destroy(rep);
+ rpcrdma_rep_put(&r_xprt->rx_buf, rep);
}
static void rpcrdma_update_cm_private(struct rpcrdma_ep *ep,
