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author | Stanislav Kinsbursky <skinsbursky@parallels.com> | 2011-10-25 14:16:36 +0300 |
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committer | Trond Myklebust <Trond.Myklebust@netapp.com> | 2011-10-25 13:15:48 +0200 |
commit | 914edb1bb2abe2ae4775368f2ffb7f41010fb81e (patch) | |
tree | c3a46e520de7e003c1a867dae4aa3740c4f074d2 /net/sunrpc/rpcb_clnt.c | |
parent | dc6f55e9f8dac4b6479be67c5c9128ad37bb491f (diff) | |
download | linux-914edb1bb2abe2ae4775368f2ffb7f41010fb81e.tar.gz linux-914edb1bb2abe2ae4775368f2ffb7f41010fb81e.tar.bz2 linux-914edb1bb2abe2ae4775368f2ffb7f41010fb81e.zip |
SUNRPC: introduce helpers for reference counted rpcbind clients
v6:
1) added write memory barrier to rpcb_set_local to make sure, that rpcbind
clients become valid before rpcb_users assignment
2) explicitly set rpcb_users to 1 instead of incrementing it (looks clearer from
my pow).
v5: fixed races with rpcb_users in rpcb_get_local()
This helpers will be used for dynamical creation and destruction of rpcbind
clients.
Variable rpcb_users is actually a counter of lauched RPC services. If rpcbind
clients has been created already, then we just increase rpcb_users.
Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Diffstat (limited to 'net/sunrpc/rpcb_clnt.c')
-rw-r--r-- | net/sunrpc/rpcb_clnt.c | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/net/sunrpc/rpcb_clnt.c b/net/sunrpc/rpcb_clnt.c index f588b852d41c..78af56579fa1 100644 --- a/net/sunrpc/rpcb_clnt.c +++ b/net/sunrpc/rpcb_clnt.c @@ -114,6 +114,9 @@ static struct rpc_program rpcb_program; static struct rpc_clnt * rpcb_local_clnt; static struct rpc_clnt * rpcb_local_clnt4; +DEFINE_SPINLOCK(rpcb_clnt_lock); +unsigned int rpcb_users; + struct rpcbind_args { struct rpc_xprt * r_xprt; @@ -161,6 +164,56 @@ static void rpcb_map_release(void *data) kfree(map); } +static int rpcb_get_local(void) +{ + int cnt; + + spin_lock(&rpcb_clnt_lock); + if (rpcb_users) + rpcb_users++; + cnt = rpcb_users; + spin_unlock(&rpcb_clnt_lock); + + return cnt; +} + +void rpcb_put_local(void) +{ + struct rpc_clnt *clnt = rpcb_local_clnt; + struct rpc_clnt *clnt4 = rpcb_local_clnt4; + int shutdown; + + spin_lock(&rpcb_clnt_lock); + if (--rpcb_users == 0) { + rpcb_local_clnt = NULL; + rpcb_local_clnt4 = NULL; + } + shutdown = !rpcb_users; + spin_unlock(&rpcb_clnt_lock); + + if (shutdown) { + /* + * cleanup_rpcb_clnt - remove xprtsock's sysctls, unregister + */ + if (clnt4) + rpc_shutdown_client(clnt4); + if (clnt) + rpc_shutdown_client(clnt); + } +} + +static void rpcb_set_local(struct rpc_clnt *clnt, struct rpc_clnt *clnt4) +{ + /* Protected by rpcb_create_local_mutex */ + rpcb_local_clnt = clnt; + rpcb_local_clnt4 = clnt4; + smp_wmb(); + rpcb_users = 1; + dprintk("RPC: created new rpcb local clients (rpcb_local_clnt: " + "%p, rpcb_local_clnt4: %p)\n", rpcb_local_clnt, + rpcb_local_clnt4); +} + /* * Returns zero on success, otherwise a negative errno value * is returned. |