1 files changed, 135 insertions, 129 deletions

diff --git a/fs/afs/addr_list.c b/fs/afs/addr_list.c
index 967db336d11a..e941da5b6dd9 100644
--- a/fs/afs/addr_list.c
+++ b/fs/afs/addr_list.c
@@ -1,12 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /* Server address list management
  *
  * Copyright (C) 2017 Red Hat, Inc. All Rights Reserved.
  * Written by David Howells (dhowells@redhat.com)
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public Licence
- * as published by the Free Software Foundation; either version
- * 2 of the Licence, or (at your option) any later version.
  */
 
 #include <linux/slab.h>
@@ -17,26 +13,55 @@
 #include "internal.h"
 #include "afs_fs.h"
 
+static void afs_free_addrlist(struct rcu_head *rcu)
+{
+	struct afs_addr_list *alist = container_of(rcu, struct afs_addr_list, rcu);
+	unsigned int i;
+
+	for (i = 0; i < alist->nr_addrs; i++)
+		rxrpc_kernel_put_peer(alist->addrs[i].peer);
+	trace_afs_alist(alist->debug_id, refcount_read(&alist->usage), afs_alist_trace_free);
+	kfree(alist);
+}
+
 /*
  * Release an address list.
  */
-void afs_put_addrlist(struct afs_addr_list *alist)
+void afs_put_addrlist(struct afs_addr_list *alist, enum afs_alist_trace reason)
 {
-	if (alist && refcount_dec_and_test(&alist->usage))
-		call_rcu(&alist->rcu, (rcu_callback_t)kfree);
+	unsigned int debug_id;
+	bool dead;
+	int r;
+
+	if (!alist)
+		return;
+	debug_id = alist->debug_id;
+	dead = __refcount_dec_and_test(&alist->usage, &r);
+	trace_afs_alist(debug_id, r - 1, reason);
+	if (dead)
+		call_rcu(&alist->rcu, afs_free_addrlist);
+}
+
+struct afs_addr_list *afs_get_addrlist(struct afs_addr_list *alist, enum afs_alist_trace reason)
+{
+	int r;
+
+	if (alist) {
+		__refcount_inc(&alist->usage, &r);
+		trace_afs_alist(alist->debug_id, r + 1, reason);
+	}
+	return alist;
 }
 
 /*
  * Allocate an address list.
  */
-struct afs_addr_list *afs_alloc_addrlist(unsigned int nr,
-					 unsigned short service,
-					 unsigned short port)
+struct afs_addr_list *afs_alloc_addrlist(unsigned int nr)
 {
 	struct afs_addr_list *alist;
-	unsigned int i;
+	static atomic_t debug_id;
 
-	_enter("%u,%u,%u", nr, service, port);
+	_enter("%u", nr);
 
 	if (nr > AFS_MAX_ADDRESSES)
 		nr = AFS_MAX_ADDRESSES;
@@ -47,17 +72,8 @@ struct afs_addr_list *afs_alloc_addrlist(unsigned int nr,
 
 	refcount_set(&alist->usage, 1);
 	alist->max_addrs = nr;
-
-	for (i = 0; i < nr; i++) {
-		struct sockaddr_rxrpc *srx = &alist->addrs[i];
-		srx->srx_family			= AF_RXRPC;
-		srx->srx_service		= service;
-		srx->transport_type		= SOCK_DGRAM;
-		srx->transport_len		= sizeof(srx->transport.sin6);
-		srx->transport.sin6.sin6_family	= AF_INET6;
-		srx->transport.sin6.sin6_port	= htons(port);
-	}
-
+	alist->debug_id = atomic_inc_return(&debug_id);
+	trace_afs_alist(alist->debug_id, 1, afs_alist_trace_alloc);
 	return alist;
 }
 
@@ -130,7 +146,7 @@ struct afs_vlserver_list *afs_parse_text_addrs(struct afs_net *net,
 	if (!vllist->servers[0].server)
 		goto error_vl;
 
-	alist = afs_alloc_addrlist(nr, service, AFS_VL_PORT);
+	alist = afs_alloc_addrlist(nr);
 	if (!alist)
 		goto error;
 
@@ -201,9 +217,11 @@ struct afs_vlserver_list *afs_parse_text_addrs(struct afs_net *net,
 		}
 
 		if (family == AF_INET)
-			afs_merge_fs_addr4(alist, x[0], xport);
+			ret = afs_merge_fs_addr4(net, alist, x[0], xport);
 		else
-			afs_merge_fs_addr6(alist, x, xport);
+			ret = afs_merge_fs_addr6(net, alist, x, xport);
+		if (ret < 0)
+			goto error;
 
 	} while (p < end);
 
@@ -220,26 +238,13 @@ bad_address:
 	       problem, p - text, (int)len, (int)len, text);
 	ret = -EINVAL;
 error:
-	afs_put_addrlist(alist);
+	afs_put_addrlist(alist, afs_alist_trace_put_parse_error);
 error_vl:
 	afs_put_vlserverlist(net, vllist);
 	return ERR_PTR(ret);
 }
 
 /*
- * Compare old and new address lists to see if there's been any change.
- * - How to do this in better than O(Nlog(N)) time?
- *   - We don't really want to sort the address list, but would rather take the
- *     list as we got it so as not to undo record rotation by the DNS server.
- */
-#if 0
-static int afs_cmp_addr_list(const struct afs_addr_list *a1,
-			     const struct afs_addr_list *a2)
-{
-}
-#endif
-
-/*
  * Perform a DNS query for VL servers and build a up an address list.
  */
 struct afs_vlserver_list *afs_dns_query(struct afs_cell *cell, time64_t *_expiry)
@@ -250,8 +255,8 @@ struct afs_vlserver_list *afs_dns_query(struct afs_cell *cell, time64_t *_expiry
 
 	_enter("%s", cell->name);
 
-	ret = dns_query("afsdb", cell->name, cell->name_len, "srv=1",
-			&result, _expiry);
+	ret = dns_query(cell->net->net, "afsdb", cell->name, cell->name_len,
+			"srv=1", &result, _expiry, true);
 	if (ret < 0) {
 		_leave(" = %d [dns]", ret);
 		return ERR_PTR(ret);
@@ -275,25 +280,33 @@ struct afs_vlserver_list *afs_dns_query(struct afs_cell *cell, time64_t *_expiry
 /*
  * Merge an IPv4 entry into a fileserver address list.
  */
-void afs_merge_fs_addr4(struct afs_addr_list *alist, __be32 xdr, u16 port)
+int afs_merge_fs_addr4(struct afs_net *net, struct afs_addr_list *alist,
+		       __be32 xdr, u16 port)
 {
-	struct sockaddr_rxrpc *srx;
-	u32 addr = ntohl(xdr);
+	struct sockaddr_rxrpc srx;
+	struct rxrpc_peer *peer;
 	int i;
 
 	if (alist->nr_addrs >= alist->max_addrs)
-		return;
+		return 0;
 
-	for (i = 0; i < alist->nr_ipv4; i++) {
-		struct sockaddr_in *a = &alist->addrs[i].transport.sin;
-		u32 a_addr = ntohl(a->sin_addr.s_addr);
-		u16 a_port = ntohs(a->sin_port);
+	srx.srx_family = AF_RXRPC;
+	srx.transport_type = SOCK_DGRAM;
+	srx.transport_len = sizeof(srx.transport.sin);
+	srx.transport.sin.sin_family = AF_INET;
+	srx.transport.sin.sin_port = htons(port);
+	srx.transport.sin.sin_addr.s_addr = xdr;
 
-		if (addr == a_addr && port == a_port)
-			return;
-		if (addr == a_addr && port < a_port)
-			break;
-		if (addr < a_addr)
+	peer = rxrpc_kernel_lookup_peer(net->socket, &srx, GFP_KERNEL);
+	if (!peer)
+		return -ENOMEM;
+
+	for (i = 0; i < alist->nr_ipv4; i++) {
+		if (peer == alist->addrs[i].peer) {
+			rxrpc_kernel_put_peer(peer);
+			return 0;
+		}
+		if (peer <= alist->addrs[i].peer)
 			break;
 	}
 
@@ -302,38 +315,42 @@ void afs_merge_fs_addr4(struct afs_addr_list *alist, __be32 xdr, u16 port)
 			alist->addrs + i,
 			sizeof(alist->addrs[0]) * (alist->nr_addrs - i));
 
-	srx = &alist->addrs[i];
-	srx->srx_family = AF_RXRPC;
-	srx->transport_type = SOCK_DGRAM;
-	srx->transport_len = sizeof(srx->transport.sin);
-	srx->transport.sin.sin_family = AF_INET;
-	srx->transport.sin.sin_port = htons(port);
-	srx->transport.sin.sin_addr.s_addr = xdr;
+	alist->addrs[i].peer = peer;
 	alist->nr_ipv4++;
 	alist->nr_addrs++;
+	return 0;
 }
 
 /*
  * Merge an IPv6 entry into a fileserver address list.
  */
-void afs_merge_fs_addr6(struct afs_addr_list *alist, __be32 *xdr, u16 port)
+int afs_merge_fs_addr6(struct afs_net *net, struct afs_addr_list *alist,
+		       __be32 *xdr, u16 port)
 {
-	struct sockaddr_rxrpc *srx;
-	int i, diff;
+	struct sockaddr_rxrpc srx;
+	struct rxrpc_peer *peer;
+	int i;
 
 	if (alist->nr_addrs >= alist->max_addrs)
-		return;
+		return 0;
 
-	for (i = alist->nr_ipv4; i < alist->nr_addrs; i++) {
-		struct sockaddr_in6 *a = &alist->addrs[i].transport.sin6;
-		u16 a_port = ntohs(a->sin6_port);
+	srx.srx_family = AF_RXRPC;
+	srx.transport_type = SOCK_DGRAM;
+	srx.transport_len = sizeof(srx.transport.sin6);
+	srx.transport.sin6.sin6_family = AF_INET6;
+	srx.transport.sin6.sin6_port = htons(port);
+	memcpy(&srx.transport.sin6.sin6_addr, xdr, 16);
 
-		diff = memcmp(xdr, &a->sin6_addr, 16);
-		if (diff == 0 && port == a_port)
-			return;
-		if (diff == 0 && port < a_port)
-			break;
-		if (diff < 0)
+	peer = rxrpc_kernel_lookup_peer(net->socket, &srx, GFP_KERNEL);
+	if (!peer)
+		return -ENOMEM;
+
+	for (i = alist->nr_ipv4; i < alist->nr_addrs; i++) {
+		if (peer == alist->addrs[i].peer) {
+			rxrpc_kernel_put_peer(peer);
+			return 0;
+		}
+		if (peer <= alist->addrs[i].peer)
 			break;
 	}
 
@@ -341,68 +358,57 @@ void afs_merge_fs_addr6(struct afs_addr_list *alist, __be32 *xdr, u16 port)
 		memmove(alist->addrs + i + 1,
 			alist->addrs + i,
 			sizeof(alist->addrs[0]) * (alist->nr_addrs - i));
-
-	srx = &alist->addrs[i];
-	srx->srx_family = AF_RXRPC;
-	srx->transport_type = SOCK_DGRAM;
-	srx->transport_len = sizeof(srx->transport.sin6);
-	srx->transport.sin6.sin6_family = AF_INET6;
-	srx->transport.sin6.sin6_port = htons(port);
-	memcpy(&srx->transport.sin6.sin6_addr, xdr, 16);
+	alist->addrs[i].peer = peer;
 	alist->nr_addrs++;
+	return 0;
 }
 
 /*
- * Get an address to try.
+ * Set the app data on the rxrpc peers an address list points to
  */
-bool afs_iterate_addresses(struct afs_addr_cursor *ac)
+void afs_set_peer_appdata(struct afs_server *server,
+			  struct afs_addr_list *old_alist,
+			  struct afs_addr_list *new_alist)
 {
-	unsigned long set, failed;
-	int index;
-
-	if (!ac->alist)
-		return false;
-
-	set = ac->alist->responded;
-	failed = ac->alist->failed;
-	_enter("%lx-%lx-%lx,%d", set, failed, ac->tried, ac->index);
-
-	ac->nr_iterations++;
-
-	set &= ~(failed | ac->tried);
-
-	if (!set)
-		return false;
-
-	index = READ_ONCE(ac->alist->preferred);
-	if (test_bit(index, &set))
-		goto selected;
+	unsigned long data = (unsigned long)server;
+	int n = 0, o = 0;
 
-	index = __ffs(set);
-
-selected:
-	ac->index = index;
-	set_bit(index, &ac->tried);
-	ac->responded = false;
-	return true;
-}
+	if (!old_alist) {
+		/* New server.  Just set all. */
+		for (; n < new_alist->nr_addrs; n++)
+			rxrpc_kernel_set_peer_data(new_alist->addrs[n].peer, data);
+		return;
+	}
+	if (!new_alist) {
+		/* Dead server.  Just remove all. */
+		for (; o < old_alist->nr_addrs; o++)
+			rxrpc_kernel_set_peer_data(old_alist->addrs[o].peer, 0);
+		return;
+	}
 
-/*
- * Release an address list cursor.
- */
-int afs_end_cursor(struct afs_addr_cursor *ac)
-{
-	struct afs_addr_list *alist;
+	/* Walk through the two lists simultaneously, setting new peers and
+	 * clearing old ones.  The two lists are ordered by pointer to peer
+	 * record.
+	 */
+	while (n < new_alist->nr_addrs && o < old_alist->nr_addrs) {
+		struct rxrpc_peer *pn = new_alist->addrs[n].peer;
+		struct rxrpc_peer *po = old_alist->addrs[o].peer;
 
-	alist = ac->alist;
-	if (alist) {
-		if (ac->responded &&
-		    ac->index != alist->preferred &&
-		    test_bit(ac->alist->preferred, &ac->tried))
-			WRITE_ONCE(alist->preferred, ac->index);
-		afs_put_addrlist(alist);
-		ac->alist = NULL;
+		if (pn == po)
+			continue;
+		if (pn < po) {
+			rxrpc_kernel_set_peer_data(pn, data);
+			n++;
+		} else {
+			rxrpc_kernel_set_peer_data(po, 0);
+			o++;
+		}
 	}
 
-	return ac->error;
+	if (n < new_alist->nr_addrs)
+		for (; n < new_alist->nr_addrs; n++)
+			rxrpc_kernel_set_peer_data(new_alist->addrs[n].peer, data);
+	if (o < old_alist->nr_addrs)
+		for (; o < old_alist->nr_addrs; o++)
+			rxrpc_kernel_set_peer_data(old_alist->addrs[o].peer, 0);
 }