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, 14 insertions, 12 deletions

diff --git a/fs/afs/internal.h b/fs/afs/internal.h
index e2adb314ab6a..ec08b4a7e499 100644
--- a/fs/afs/internal.h
+++ b/fs/afs/internal.h
@@ -72,6 +72,11 @@ enum afs_call_state {
 	AFS_CALL_COMPLETE,		/* Completed or failed */
 };
 
+struct afs_address {
+	struct rxrpc_peer	*peer;
+	u16			service_id;
+};
+
 /*
  * List of server addresses.
  */
@@ -87,9 +92,7 @@ struct afs_addr_list {
 	enum dns_lookup_status	status:8;
 	unsigned long		failed;		/* Mask of addrs that failed locally/ICMP */
 	unsigned long		responded;	/* Mask of addrs that responded */
-	struct {
-		struct sockaddr_rxrpc	srx;
-	} addrs[] __counted_by(max_addrs);
+	struct afs_address	addrs[] __counted_by(max_addrs);
 #define AFS_MAX_ADDRESSES ((unsigned int)(sizeof(unsigned long) * 8))
 };
 
@@ -420,7 +423,7 @@ struct afs_vlserver {
 	atomic_t		probe_outstanding;
 	spinlock_t		probe_lock;
 	struct {
-		unsigned int	rtt;		/* RTT in uS */
+		unsigned int	rtt;		/* Best RTT in uS (or UINT_MAX) */
 		u32		abort_code;
 		short		error;
 		unsigned short	flags;
@@ -537,7 +540,7 @@ struct afs_server {
 	atomic_t		probe_outstanding;
 	spinlock_t		probe_lock;
 	struct {
-		unsigned int	rtt;		/* RTT in uS */
+		unsigned int	rtt;		/* Best RTT in uS (or UINT_MAX) */
 		u32		abort_code;
 		short		error;
 		bool		responded:1;
@@ -964,9 +967,7 @@ static inline struct afs_addr_list *afs_get_addrlist(struct afs_addr_list *alist
 		refcount_inc(&alist->usage);
 	return alist;
 }
-extern struct afs_addr_list *afs_alloc_addrlist(unsigned int,
-						unsigned short,
-						unsigned short);
+extern struct afs_addr_list *afs_alloc_addrlist(unsigned int nr, u16 service_id);
 extern void afs_put_addrlist(struct afs_addr_list *);
 extern struct afs_vlserver_list *afs_parse_text_addrs(struct afs_net *,
 						      const char *, size_t, char,
@@ -977,8 +978,10 @@ extern struct afs_vlserver_list *afs_dns_query(struct afs_cell *, time64_t *);
 extern bool afs_iterate_addresses(struct afs_addr_cursor *);
 extern int afs_end_cursor(struct afs_addr_cursor *);
 
-extern void afs_merge_fs_addr4(struct afs_addr_list *, __be32, u16);
-extern void afs_merge_fs_addr6(struct afs_addr_list *, __be32 *, u16);
+extern int afs_merge_fs_addr4(struct afs_net *net, struct afs_addr_list *addr,
+			      __be32 xdr, u16 port);
+extern int afs_merge_fs_addr6(struct afs_net *net, struct afs_addr_list *addr,
+			      __be32 *xdr, u16 port);
 
 /*
  * callback.c
@@ -1405,8 +1408,7 @@ extern void __exit afs_clean_up_permit_cache(void);
  */
 extern spinlock_t afs_server_peer_lock;
 
-extern struct afs_server *afs_find_server(struct afs_net *,
-					  const struct sockaddr_rxrpc *);
+extern struct afs_server *afs_find_server(struct afs_net *, const struct rxrpc_peer *);
 extern struct afs_server *afs_find_server_by_uuid(struct afs_net *, const uuid_t *);
 extern struct afs_server *afs_lookup_server(struct afs_cell *, struct key *, const uuid_t *, u32);
 extern struct afs_server *afs_get_server(struct afs_server *, enum afs_server_trace);