From: Trond Myklebust trond.myklebust@hammerspace.com
[ Upstream commit f99fa50880f5300fbbb3c0754ddc7f8738d24fe7 ]
The xprtrdma client code currently relies on the task that initiated the connect to hold the XPRT_LOCK for the duration of the connection attempt. If the task is woken early, due to some other event, then that lock could get released early. Avoid races by using the same mechanism that the socket code uses of transferring lock ownership to the RDMA connect worker itself. That frees us to call rpcrdma_xprt_disconnect() directly since we're now guaranteed exclusion w.r.t. other callers.
Fixes: 4cf44be6f1e8 ("xprtrdma: Fix recursion into rpcrdma_xprt_disconnect()") Signed-off-by: Trond Myklebust trond.myklebust@hammerspace.com Signed-off-by: Anna Schumaker Anna.Schumaker@Netapp.com Signed-off-by: Sasha Levin sashal@kernel.org --- net/sunrpc/xprt.c | 2 ++ net/sunrpc/xprtrdma/transport.c | 11 +++++------ 2 files changed, 7 insertions(+), 6 deletions(-)
diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c index ccfa85e995fd..8201531ce5d9 100644 --- a/net/sunrpc/xprt.c +++ b/net/sunrpc/xprt.c @@ -844,6 +844,7 @@ bool xprt_lock_connect(struct rpc_xprt *xprt, spin_unlock(&xprt->transport_lock); return ret; } +EXPORT_SYMBOL_GPL(xprt_lock_connect);
void xprt_unlock_connect(struct rpc_xprt *xprt, void *cookie) { @@ -860,6 +861,7 @@ void xprt_unlock_connect(struct rpc_xprt *xprt, void *cookie) spin_unlock(&xprt->transport_lock); wake_up_bit(&xprt->state, XPRT_LOCKED); } +EXPORT_SYMBOL_GPL(xprt_unlock_connect);
/** * xprt_connect - schedule a transport connect operation diff --git a/net/sunrpc/xprtrdma/transport.c b/net/sunrpc/xprtrdma/transport.c index c26db0a37996..8e2368a0c2a2 100644 --- a/net/sunrpc/xprtrdma/transport.c +++ b/net/sunrpc/xprtrdma/transport.c @@ -249,12 +249,9 @@ xprt_rdma_connect_worker(struct work_struct *work) xprt->stat.connect_start; xprt_set_connected(xprt); rc = -EAGAIN; - } else { - /* Force a call to xprt_rdma_close to clean up */ - spin_lock(&xprt->transport_lock); - set_bit(XPRT_CLOSE_WAIT, &xprt->state); - spin_unlock(&xprt->transport_lock); - } + } else + rpcrdma_xprt_disconnect(r_xprt); + xprt_unlock_connect(xprt, r_xprt); xprt_wake_pending_tasks(xprt, rc); }
@@ -487,6 +484,8 @@ xprt_rdma_connect(struct rpc_xprt *xprt, struct rpc_task *task) struct rpcrdma_ep *ep = r_xprt->rx_ep; unsigned long delay;
+ WARN_ON_ONCE(!xprt_lock_connect(xprt, task, r_xprt)); + delay = 0; if (ep && ep->re_connect_status != 0) { delay = xprt_reconnect_delay(xprt);