diff options
| author | \"Talpey, Thomas\ <Thomas.Talpey@netapp.com> | 2007-09-10 13:46:00 -0400 |
|---|---|---|
| committer | Trond Myklebust <Trond.Myklebust@netapp.com> | 2007-10-09 17:17:40 -0400 |
| commit | 81c098af3da7981902e9f8163aeccc2467c4ba6d (patch) | |
| tree | b98e3c8c9e519e34abf721410de70373cedb4a9f /net/sunrpc/xprt.c | |
| parent | 1244480976d357447aeddd3f44977586bfa0462b (diff) | |
SUNRPC: Provide a new API for registering transport implementations
To allow transport capabilities to be loaded dynamically, provide an API
for registering and unregistering the transports with the RPC client.
Eventually xprt_create_transport() will be changed to search the list of
registered transports when initializing a fresh transport.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Tom Talpey <tmt@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Diffstat (limited to 'net/sunrpc/xprt.c')
| -rw-r--r-- | net/sunrpc/xprt.c | 75 |
1 files changed, 75 insertions, 0 deletions
diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c index bc13616e7fdc..520859622af5 100644 --- a/net/sunrpc/xprt.c +++ b/net/sunrpc/xprt.c @@ -62,6 +62,9 @@ static inline void do_xprt_reserve(struct rpc_task *); static void xprt_connect_status(struct rpc_task *task); static int __xprt_get_cong(struct rpc_xprt *, struct rpc_task *); +static spinlock_t xprt_list_lock = SPIN_LOCK_UNLOCKED; +static LIST_HEAD(xprt_list); + /* * The transport code maintains an estimate on the maximum number of out- * standing RPC requests, using a smoothed version of the congestion @@ -81,6 +84,78 @@ static int __xprt_get_cong(struct rpc_xprt *, struct rpc_task *); #define RPCXPRT_CONGESTED(xprt) ((xprt)->cong >= (xprt)->cwnd) /** + * xprt_register_transport - register a transport implementation + * @transport: transport to register + * + * If a transport implementation is loaded as a kernel module, it can + * call this interface to make itself known to the RPC client. + * + * Returns: + * 0: transport successfully registered + * -EEXIST: transport already registered + * -EINVAL: transport module being unloaded + */ +int xprt_register_transport(struct xprt_class *transport) +{ + struct xprt_class *t; + int result; + + result = -EEXIST; + spin_lock(&xprt_list_lock); + list_for_each_entry(t, &xprt_list, list) { + /* don't register the same transport class twice */ + if (t == transport) + goto out; + } + + result = -EINVAL; + if (try_module_get(THIS_MODULE)) { + list_add_tail(&transport->list, &xprt_list); + printk(KERN_INFO "RPC: Registered %s transport module.\n", + transport->name); + result = 0; + } + +out: + spin_unlock(&xprt_list_lock); + return result; +} +EXPORT_SYMBOL_GPL(xprt_register_transport); + +/** + * xprt_unregister_transport - unregister a transport implementation + * transport: transport to unregister + * + * Returns: + * 0: transport successfully unregistered + * -ENOENT: transport never registered + */ +int xprt_unregister_transport(struct xprt_class *transport) +{ + struct xprt_class *t; + int result; + + result = 0; + spin_lock(&xprt_list_lock); + list_for_each_entry(t, &xprt_list, list) { + if (t == transport) { + printk(KERN_INFO + "RPC: Unregistered %s transport module.\n", + transport->name); + list_del_init(&transport->list); + module_put(THIS_MODULE); + goto out; + } + } + result = -ENOENT; + +out: + spin_unlock(&xprt_list_lock); + return result; +} +EXPORT_SYMBOL_GPL(xprt_unregister_transport); + +/** * xprt_reserve_xprt - serialize write access to transports * @task: task that is requesting access to the transport * |