[PATCH v2 3/4] SUNRPC: Create a helper function for accessing the rpc_clnt's xprt_switch
From: Anna Schumaker <anna@kernel.org>
Date: 2023-12-04 20:25:16
Subsystem:
kernel nfsd, sunrpc, and lockd servers, networking [general], nfs, sunrpc, and lockd clients, the rest · Maintainers:
Chuck Lever, Jeff Layton, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Trond Myklebust, Anna Schumaker, Linus Torvalds
From: Anna Schumaker <redacted> This function takes the necessary rcu read lock to dereference the client's rpc_xprt_switch and bump the reference count so it doesn't disappear underneath us before returning. This does mean that callers are responsible for calling xprt_switch_put() on the returned object when they are done with it. Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Anna Schumaker <redacted> --- net/sunrpc/clnt.c | 34 +++++++++++++++++++++------------- 1 file changed, 21 insertions(+), 13 deletions(-)
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index 8df944444e9b..0b2c4b5484f5 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c@@ -797,15 +797,24 @@ int rpc_switch_client_transport(struct rpc_clnt *clnt, } EXPORT_SYMBOL_GPL(rpc_switch_client_transport); +static struct rpc_xprt_switch *rpc_clnt_xprt_switch_get(struct rpc_clnt *clnt) +{ + struct rpc_xprt_switch *xps; + + rcu_read_lock(); + xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch)); + rcu_read_unlock(); + + return xps; +} + static int _rpc_clnt_xprt_iter_init(struct rpc_clnt *clnt, struct rpc_xprt_iter *xpi, void func(struct rpc_xprt_iter *xpi, struct rpc_xprt_switch *xps)) { struct rpc_xprt_switch *xps; - rcu_read_lock(); - xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch)); - rcu_read_unlock(); + xps = rpc_clnt_xprt_switch_get(clnt); if (xps == NULL) return -EAGAIN; func(xpi, xps);
@@ -2206,9 +2215,7 @@ call_connect_status(struct rpc_task *task) struct rpc_xprt *saved = task->tk_xprt; struct rpc_xprt_switch *xps; - rcu_read_lock(); - xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch)); - rcu_read_unlock(); + xps = rpc_clnt_xprt_switch_get(clnt); if (xps->xps_nxprts > 1) { long value;
@@ -3251,22 +3258,23 @@ void rpc_clnt_xprt_set_online(struct rpc_clnt *clnt, struct rpc_xprt *xprt) { struct rpc_xprt_switch *xps; - rcu_read_lock(); - xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch); - rcu_read_unlock(); + xps = rpc_clnt_xprt_switch_get(clnt); xprt_set_online_locked(xprt, xps); + xprt_switch_put(xps); } void rpc_clnt_xprt_switch_add_xprt(struct rpc_clnt *clnt, struct rpc_xprt *xprt) { + struct rpc_xprt_switch *xps; + if (rpc_clnt_xprt_switch_has_addr(clnt, (const struct sockaddr *)&xprt->addr)) { return rpc_clnt_xprt_set_online(clnt, xprt); } - rcu_read_lock(); - rpc_xprt_switch_add_xprt(rcu_dereference(clnt->cl_xpi.xpi_xpswitch), - xprt); - rcu_read_unlock(); + + xps = rpc_clnt_xprt_switch_get(clnt); + rpc_xprt_switch_add_xprt(xps, xprt); + xprt_switch_put(xps); } EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_add_xprt);
--
2.43.0