From fda0ab41170ee0a1c7a3781ff8cfb4395c3dd784 Mon Sep 17 00:00:00 2001 From: Andy Adamson Date: Fri, 9 Sep 2016 09:22:26 -0400 Subject: [PATCH] SUNRPC: rpc_clnt_add_xprt setup function for NFS layer Use a setup function to call into the NFS layer to test an rpc_xprt for session trunking so as to not leak the rpc_xprt_switch into the nfs layer. Search for the address in the rpc_xprt_switch first so as not to put an unnecessary EXCHANGE_ID on the wire. Signed-off-by: Andy Adamson Signed-off-by: Anna Schumaker --- include/linux/sunrpc/clnt.h | 12 +++++++ net/sunrpc/clnt.c | 64 +++++++++++++++++++++++++++++++++++++ 2 files changed, 76 insertions(+) diff --git a/include/linux/sunrpc/clnt.h b/include/linux/sunrpc/clnt.h index 35cc539e2921..85cc819676e8 100644 --- a/include/linux/sunrpc/clnt.h +++ b/include/linux/sunrpc/clnt.h @@ -125,6 +125,13 @@ struct rpc_create_args { struct svc_xprt *bc_xprt; /* NFSv4.1 backchannel */ }; +struct rpc_add_xprt_test { + int (*add_xprt_test)(struct rpc_clnt *, + struct rpc_xprt *, + void *calldata); + void *data; +}; + /* Values for "flags" field */ #define RPC_CLNT_CREATE_HARDRTRY (1UL << 0) #define RPC_CLNT_CREATE_AUTOBIND (1UL << 2) @@ -198,6 +205,11 @@ int rpc_clnt_add_xprt(struct rpc_clnt *, struct xprt_create *, void rpc_cap_max_reconnect_timeout(struct rpc_clnt *clnt, unsigned long timeo); +int rpc_clnt_setup_test_and_add_xprt(struct rpc_clnt *, + struct rpc_xprt_switch *, + struct rpc_xprt *, + void *); + const char *rpc_proc_name(const struct rpc_task *task); void rpc_clnt_xprt_switch_put(struct rpc_clnt *); diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c index 8d68efd2026f..b614cb1356b9 100644 --- a/net/sunrpc/clnt.c +++ b/net/sunrpc/clnt.c @@ -2613,6 +2613,70 @@ int rpc_clnt_test_and_add_xprt(struct rpc_clnt *clnt, } EXPORT_SYMBOL_GPL(rpc_clnt_test_and_add_xprt); +/** + * rpc_clnt_setup_test_and_add_xprt() + * + * This is an rpc_clnt_add_xprt setup() function which returns 1 so: + * 1) caller of the test function must dereference the rpc_xprt_switch + * and the rpc_xprt. + * 2) test function must call rpc_xprt_switch_add_xprt, usually in + * the rpc_call_done routine. + * + * Upon success (return of 1), the test function adds the new + * transport to the rpc_clnt xprt switch + * + * @clnt: struct rpc_clnt to get the new transport + * @xps: the rpc_xprt_switch to hold the new transport + * @xprt: the rpc_xprt to test + * @data: a struct rpc_add_xprt_test pointer that holds the test function + * and test function call data + */ +int rpc_clnt_setup_test_and_add_xprt(struct rpc_clnt *clnt, + struct rpc_xprt_switch *xps, + struct rpc_xprt *xprt, + void *data) +{ + struct rpc_cred *cred; + struct rpc_task *task; + struct rpc_add_xprt_test *xtest = (struct rpc_add_xprt_test *)data; + int status = -EADDRINUSE; + + xprt = xprt_get(xprt); + xprt_switch_get(xps); + + if (rpc_xprt_switch_has_addr(xps, (struct sockaddr *)&xprt->addr)) + goto out_err; + + /* Test the connection */ + cred = authnull_ops.lookup_cred(NULL, NULL, 0); + task = rpc_call_null_helper(clnt, xprt, cred, + RPC_TASK_SOFT | RPC_TASK_SOFTCONN, + NULL, NULL); + put_rpccred(cred); + if (IS_ERR(task)) { + status = PTR_ERR(task); + goto out_err; + } + status = task->tk_status; + rpc_put_task(task); + + if (status < 0) + goto out_err; + + /* rpc_xprt_switch and rpc_xprt are deferrenced by add_xprt_test() */ + xtest->add_xprt_test(clnt, xprt, xtest->data); + + /* so that rpc_clnt_add_xprt does not call rpc_xprt_switch_add_xprt */ + return 1; +out_err: + xprt_put(xprt); + xprt_switch_put(xps); + pr_info("RPC: rpc_clnt_test_xprt failed: %d addr %s not added\n", + status, xprt->address_strings[RPC_DISPLAY_ADDR]); + return status; +} +EXPORT_SYMBOL_GPL(rpc_clnt_setup_test_and_add_xprt); + /** * rpc_clnt_add_xprt - Add a new transport to a rpc_clnt * @clnt: pointer to struct rpc_clnt -- 2.45.2