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, 10 insertions, 5 deletions

diff --git a/fs/afs/vl_list.c b/fs/afs/vl_list.c
index acc48216136a..ba89140eee9e 100644
--- a/fs/afs/vl_list.c
+++ b/fs/afs/vl_list.c
@@ -83,14 +83,15 @@ static u16 afs_extract_le16(const u8 **_b)
 /*
  * Build a VL server address list from a DNS queried server list.
  */
-static struct afs_addr_list *afs_extract_vl_addrs(const u8 **_b, const u8 *end,
+static struct afs_addr_list *afs_extract_vl_addrs(struct afs_net *net,
+						  const u8 **_b, const u8 *end,
 						  u8 nr_addrs, u16 port)
 {
 	struct afs_addr_list *alist;
 	const u8 *b = *_b;
 	int ret = -EINVAL;
 
-	alist = afs_alloc_addrlist(nr_addrs, VL_SERVICE, port);
+	alist = afs_alloc_addrlist(nr_addrs, VL_SERVICE);
 	if (!alist)
 		return ERR_PTR(-ENOMEM);
 	if (nr_addrs == 0)
@@ -109,7 +110,9 @@ static struct afs_addr_list *afs_extract_vl_addrs(const u8 **_b, const u8 *end,
 				goto error;
 			}
 			memcpy(x, b, 4);
-			afs_merge_fs_addr4(alist, x[0], port);
+			ret = afs_merge_fs_addr4(net, alist, x[0], port);
+			if (ret < 0)
+				goto error;
 			b += 4;
 			break;
 
@@ -119,7 +122,9 @@ static struct afs_addr_list *afs_extract_vl_addrs(const u8 **_b, const u8 *end,
 				goto error;
 			}
 			memcpy(x, b, 16);
-			afs_merge_fs_addr6(alist, x, port);
+			ret = afs_merge_fs_addr6(net, alist, x, port);
+			if (ret < 0)
+				goto error;
 			b += 16;
 			break;
 
@@ -247,7 +252,7 @@ struct afs_vlserver_list *afs_extract_vlserver_list(struct afs_cell *cell,
 		/* Extract the addresses - note that we can't skip this as we
 		 * have to advance the payload pointer.
 		 */
-		addrs = afs_extract_vl_addrs(&b, end, bs.nr_addrs, bs.port);
+		addrs = afs_extract_vl_addrs(cell->net, &b, end, bs.nr_addrs, bs.port);
 		if (IS_ERR(addrs)) {
 			ret = PTR_ERR(addrs);
 			goto error_2;