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authorChuck Lever <chuck.lever@oracle.com>2020-04-17 18:40:31 +0200
committerChuck Lever <chuck.lever@oracle.com>2020-04-17 18:40:31 +0200
commit6221f1d9b63fed6260273e59a2b89ab30537a811 (patch)
tree698698f228e81683fe292982fffca41181618881 /net/sunrpc
parentSUNRPC/cache: Fix unsafe traverse caused double-free in cache_purge (diff)
downloadlinux-6221f1d9b63fed6260273e59a2b89ab30537a811.tar.xz
linux-6221f1d9b63fed6260273e59a2b89ab30537a811.zip
SUNRPC: Fix backchannel RPC soft lockups
Currently, after the forward channel connection goes away, backchannel operations are causing soft lockups on the server because call_transmit_status's SOFTCONN logic ignores ENOTCONN. Such backchannel Calls are aggressively retried until the client reconnects. Backchannel Calls should use RPC_TASK_NOCONNECT rather than RPC_TASK_SOFTCONN. If there is no forward connection, the server is not capable of establishing a connection back to the client, thus that backchannel request should fail before the server attempts to send it. Commit 58255a4e3ce5 ("NFSD: NFSv4 callback client should use RPC_TASK_SOFTCONN") was merged several years before RPC_TASK_NOCONNECT was available. Because setup_callback_client() explicitly sets NOPING, the NFSv4.0 callback connection depends on the first callback RPC to initiate a connection to the client. Thus NFSv4.0 needs to continue to use RPC_TASK_SOFTCONN. Suggested-by: Trond Myklebust <trondmy@hammerspace.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Cc: <stable@vger.kernel.org> # v4.20+
Diffstat (limited to 'net/sunrpc')
-rw-r--r--net/sunrpc/svc_xprt.c2
-rw-r--r--net/sunrpc/xprtrdma/svc_rdma_backchannel.c2
-rw-r--r--net/sunrpc/xprtsock.c1
3 files changed, 5 insertions, 0 deletions
diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c
index e27e3532ec75..92f2c08c67a5 100644
--- a/net/sunrpc/svc_xprt.c
+++ b/net/sunrpc/svc_xprt.c
@@ -1040,6 +1040,8 @@ static void svc_delete_xprt(struct svc_xprt *xprt)
dprintk("svc: svc_delete_xprt(%p)\n", xprt);
xprt->xpt_ops->xpo_detach(xprt);
+ if (xprt->xpt_bc_xprt)
+ xprt->xpt_bc_xprt->ops->close(xprt->xpt_bc_xprt);
spin_lock_bh(&serv->sv_lock);
list_del_init(&xprt->xpt_list);
diff --git a/net/sunrpc/xprtrdma/svc_rdma_backchannel.c b/net/sunrpc/xprtrdma/svc_rdma_backchannel.c
index d510a3a15d4b..af7eb8d202ae 100644
--- a/net/sunrpc/xprtrdma/svc_rdma_backchannel.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_backchannel.c
@@ -244,6 +244,8 @@ static void
xprt_rdma_bc_close(struct rpc_xprt *xprt)
{
dprintk("svcrdma: %s: xprt %p\n", __func__, xprt);
+
+ xprt_disconnect_done(xprt);
xprt->cwnd = RPC_CWNDSHIFT;
}
diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
index 0bda8a73e8a8..845d0be805ec 100644
--- a/net/sunrpc/xprtsock.c
+++ b/net/sunrpc/xprtsock.c
@@ -2584,6 +2584,7 @@ static int bc_send_request(struct rpc_rqst *req)
static void bc_close(struct rpc_xprt *xprt)
{
+ xprt_disconnect_done(xprt);
}
/*