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, 7 insertions, 34 deletions

diff --git a/fs/afs/server.c b/fs/afs/server.c
index b8e2d211d4a1..5b5fa94005c9 100644
--- a/fs/afs/server.c
+++ b/fs/afs/server.c
@@ -21,13 +21,12 @@ static void __afs_put_server(struct afs_net *, struct afs_server *);
 /*
  * Find a server by one of its addresses.
  */
-struct afs_server *afs_find_server(struct afs_net *net,
-				   const struct sockaddr_rxrpc *srx)
+struct afs_server *afs_find_server(struct afs_net *net, const struct rxrpc_peer *peer)
 {
 	const struct afs_addr_list *alist;
 	struct afs_server *server = NULL;
 	unsigned int i;
-	int seq = 1, diff;
+	int seq = 1;
 
 	rcu_read_lock();
 
@@ -38,37 +37,11 @@ struct afs_server *afs_find_server(struct afs_net *net,
 		seq++; /* 2 on the 1st/lockless path, otherwise odd */
 		read_seqbegin_or_lock(&net->fs_addr_lock, &seq);
 
-		if (srx->transport.family == AF_INET6) {
-			const struct sockaddr_in6 *a = &srx->transport.sin6, *b;
-			hlist_for_each_entry_rcu(server, &net->fs_addresses6, addr6_link) {
-				alist = rcu_dereference(server->addresses);
-				for (i = alist->nr_ipv4; i < alist->nr_addrs; i++) {
-					b = &alist->addrs[i].srx.transport.sin6;
-					diff = ((u16 __force)a->sin6_port -
-						(u16 __force)b->sin6_port);
-					if (diff == 0)
-						diff = memcmp(&a->sin6_addr,
-							      &b->sin6_addr,
-							      sizeof(struct in6_addr));
-					if (diff == 0)
-						goto found;
-				}
-			}
-		} else {
-			const struct sockaddr_in *a = &srx->transport.sin, *b;
-			hlist_for_each_entry_rcu(server, &net->fs_addresses4, addr4_link) {
-				alist = rcu_dereference(server->addresses);
-				for (i = 0; i < alist->nr_ipv4; i++) {
-					b = &alist->addrs[i].srx.transport.sin;
-					diff = ((u16 __force)a->sin_port -
-						(u16 __force)b->sin_port);
-					if (diff == 0)
-						diff = ((u32 __force)a->sin_addr.s_addr -
-							(u32 __force)b->sin_addr.s_addr);
-					if (diff == 0)
-						goto found;
-				}
-			}
+		hlist_for_each_entry_rcu(server, &net->fs_addresses6, addr6_link) {
+			alist = rcu_dereference(server->addresses);
+			for (i = 0; i < alist->nr_addrs; i++)
+				if (alist->addrs[i].peer == peer)
+					goto found;
 		}
 
 		server = NULL;