SUNRPC: Fix a backchannel deadlock
xprt_alloc_bc_request() cannot call xprt_free_bc_request() without
deadlocking, since it already holds the xprt->bc_pa_lock.
Reported-by: Chuck Lever <chuck.lever@oracle.com>
Fixes: 0d2a970d0ae55 ("SUNRPC: Fix a backchannel race")
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
diff --git a/net/sunrpc/backchannel_rqst.c b/net/sunrpc/backchannel_rqst.c
index 9825ff0..5a3b50a 100644
--- a/net/sunrpc/backchannel_rqst.c
+++ b/net/sunrpc/backchannel_rqst.c
@@ -240,8 +240,8 @@
req = xprt_alloc_bc_req(xprt, GFP_ATOMIC);
if (!req)
goto not_found;
- /* Note: this 'free' request adds it to xprt->bc_pa_list */
- xprt_free_bc_request(req);
+ list_add_tail(&req->rq_bc_pa_list, &xprt->bc_pa_list);
+ xprt->bc_alloc_count++;
}
req = list_first_entry(&xprt->bc_pa_list, struct rpc_rqst,
rq_bc_pa_list);