rxrpc, afs: Allow afs to pin rxrpc_peer objects

Change rxrpc's API such that:

 (1) A new function, rxrpc_kernel_lookup_peer(), is provided to look up an
     rxrpc_peer record for a remote address and a corresponding function,
     rxrpc_kernel_put_peer(), is provided to dispose of it again.

 (2) When setting up a call, the rxrpc_peer object used during a call is
     now passed in rather than being set up by rxrpc_connect_call().  For
     afs, this meenat passing it to rxrpc_kernel_begin_call() rather than
     the full address (the service ID then has to be passed in as a
     separate parameter).

 (3) A new function, rxrpc_kernel_remote_addr(), is added so that afs can
     get a pointer to the transport address for display purposed, and
     another, rxrpc_kernel_remote_srx(), to gain a pointer to the full
     rxrpc address.

 (4) The function to retrieve the RTT from a call, rxrpc_kernel_get_srtt(),
     is then altered to take a peer.  This now returns the RTT or -1 if
     there are insufficient samples.

 (5) Rename rxrpc_kernel_get_peer() to rxrpc_kernel_call_get_peer().

 (6) Provide a new function, rxrpc_kernel_get_peer(), to get a ref on a
     peer the caller already has.

This allows the afs filesystem to pin the rxrpc_peer records that it is
using, allowing faster lookups and pointer comparisons rather than
comparing sockaddr_rxrpc contents.  It also makes it easier to get hold of
the RTT.  The following changes are made to afs:

 (1) The addr_list struct's addrs[] elements now hold a peer struct pointer
     and a service ID rather than a sockaddr_rxrpc.

 (2) When displaying the transport address, rxrpc_kernel_remote_addr() is
     used.

 (3) The port arg is removed from afs_alloc_addrlist() since it's always
     overridden.

 (4) afs_merge_fs_addr4() and afs_merge_fs_addr6() do peer lookup and may
     now return an error that must be handled.

 (5) afs_find_server() now takes a peer pointer to specify the address.

 (6) afs_find_server(), afs_compare_fs_alists() and afs_merge_fs_addr[46]{}
     now do peer pointer comparison rather than address comparison.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org

1 files changed, 9 insertions, 8 deletions

diff --git a/net/rxrpc/call_object.c b/net/rxrpc/call_object.c
index 773eecd1e979..beea25ac88f5 100644
--- a/net/rxrpc/call_object.c
+++ b/net/rxrpc/call_object.c
@@ -193,7 +193,6 @@ struct rxrpc_call *rxrpc_alloc_call(struct rxrpc_sock *rx, gfp_t gfp,
  * Allocate a new client call.
  */
 static struct rxrpc_call *rxrpc_alloc_client_call(struct rxrpc_sock *rx,
-						  struct sockaddr_rxrpc *srx,
 						  struct rxrpc_conn_parameters *cp,
 						  struct rxrpc_call_params *p,
 						  gfp_t gfp,
@@ -211,10 +210,12 @@ static struct rxrpc_call *rxrpc_alloc_client_call(struct rxrpc_sock *rx,
 	now = ktime_get_real();
 	call->acks_latest_ts	= now;
 	call->cong_tstamp	= now;
-	call->dest_srx		= *srx;
+	call->dest_srx		= cp->peer->srx;
+	call->dest_srx.srx_service = cp->service_id;
 	call->interruptibility	= p->interruptibility;
 	call->tx_total_len	= p->tx_total_len;
 	call->key		= key_get(cp->key);
+	call->peer		= rxrpc_get_peer(cp->peer, rxrpc_peer_get_call);
 	call->local		= rxrpc_get_local(cp->local, rxrpc_local_get_call);
 	call->security_level	= cp->security_level;
 	if (p->kernel)
@@ -306,10 +307,6 @@ static int rxrpc_connect_call(struct rxrpc_call *call, gfp_t gfp)
 
 	_enter("{%d,%lx},", call->debug_id, call->user_call_ID);
 
-	call->peer = rxrpc_lookup_peer(local, &call->dest_srx, gfp);
-	if (!call->peer)
-		goto error;
-
 	ret = rxrpc_look_up_bundle(call, gfp);
 	if (ret < 0)
 		goto error;
@@ -334,7 +331,6 @@ error:
  */
 struct rxrpc_call *rxrpc_new_client_call(struct rxrpc_sock *rx,
 					 struct rxrpc_conn_parameters *cp,
-					 struct sockaddr_rxrpc *srx,
 					 struct rxrpc_call_params *p,
 					 gfp_t gfp,
 					 unsigned int debug_id)
@@ -349,13 +345,18 @@ struct rxrpc_call *rxrpc_new_client_call(struct rxrpc_sock *rx,
 
 	_enter("%p,%lx", rx, p->user_call_ID);
 
+	if (WARN_ON_ONCE(!cp->peer)) {
+		release_sock(&rx->sk);
+		return ERR_PTR(-EIO);
+	}
+
 	limiter = rxrpc_get_call_slot(p, gfp);
 	if (!limiter) {
 		release_sock(&rx->sk);
 		return ERR_PTR(-ERESTARTSYS);
 	}
 
-	call = rxrpc_alloc_client_call(rx, srx, cp, p, gfp, debug_id);
+	call = rxrpc_alloc_client_call(rx, cp, p, gfp, debug_id);
 	if (IS_ERR(call)) {
 		release_sock(&rx->sk);
 		up(limiter);