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, 15 insertions, 7 deletions

diff --git a/fs/afs/vlclient.c b/fs/afs/vlclient.c
index 00fca3c66ba6..41e7932d75c6 100644
--- a/fs/afs/vlclient.c
+++ b/fs/afs/vlclient.c
@@ -208,7 +208,7 @@ static int afs_deliver_vl_get_addrs_u(struct afs_call *call)
 		count		= ntohl(*bp);
 
 		nentries = min(nentries, count);
-		alist = afs_alloc_addrlist(nentries, FS_SERVICE, AFS_FS_PORT);
+		alist = afs_alloc_addrlist(nentries, FS_SERVICE);
 		if (!alist)
 			return -ENOMEM;
 		alist->version = uniquifier;
@@ -230,9 +230,13 @@ static int afs_deliver_vl_get_addrs_u(struct afs_call *call)
 		alist = call->ret_alist;
 		bp = call->buffer;
 		count = min(call->count, 4U);
-		for (i = 0; i < count; i++)
-			if (alist->nr_addrs < call->count2)
-				afs_merge_fs_addr4(alist, *bp++, AFS_FS_PORT);
+		for (i = 0; i < count; i++) {
+			if (alist->nr_addrs < call->count2) {
+				ret = afs_merge_fs_addr4(call->net, alist, *bp++, AFS_FS_PORT);
+				if (ret < 0)
+					return ret;
+			}
+		}
 
 		call->count -= count;
 		if (call->count > 0)
@@ -450,7 +454,7 @@ static int afs_deliver_yfsvl_get_endpoints(struct afs_call *call)
 		if (call->count > YFS_MAXENDPOINTS)
 			return afs_protocol_error(call, afs_eproto_yvl_fsendpt_num);
 
-		alist = afs_alloc_addrlist(call->count, FS_SERVICE, AFS_FS_PORT);
+		alist = afs_alloc_addrlist(call->count, FS_SERVICE);
 		if (!alist)
 			return -ENOMEM;
 		alist->version = uniquifier;
@@ -488,14 +492,18 @@ static int afs_deliver_yfsvl_get_endpoints(struct afs_call *call)
 			if (ntohl(bp[0]) != sizeof(__be32) * 2)
 				return afs_protocol_error(
 					call, afs_eproto_yvl_fsendpt4_len);
-			afs_merge_fs_addr4(alist, bp[1], ntohl(bp[2]));
+			ret = afs_merge_fs_addr4(call->net, alist, bp[1], ntohl(bp[2]));
+			if (ret < 0)
+				return ret;
 			bp += 3;
 			break;
 		case YFS_ENDPOINT_IPV6:
 			if (ntohl(bp[0]) != sizeof(__be32) * 5)
 				return afs_protocol_error(
 					call, afs_eproto_yvl_fsendpt6_len);
-			afs_merge_fs_addr6(alist, bp + 1, ntohl(bp[5]));
+			ret = afs_merge_fs_addr6(call->net, alist, bp + 1, ntohl(bp[5]));
+			if (ret < 0)
+				return ret;
 			bp += 6;
 			break;
 		default: