2 /* AFS server record management
14 static unsigned afs_server_gc_delay = 10;	/* Server record timeout in seconds */
22  * Find a server by one of its addresses.
28 	struct afs_server *server = NULL;  in afs_find_server()  local
35 		if (server)  in afs_find_server()
36 			afs_unuse_server_notime(net, server, afs_server_trace_put_find_rsq);  in afs_find_server()
37 		server = NULL;  in afs_find_server()
43 			hlist_for_each_entry_rcu(server, &net->fs_addresses6, addr6_link) {  in afs_find_server()
44 				alist = rcu_dereference(server->addresses);  in afs_find_server()
59 			hlist_for_each_entry_rcu(server, &net->fs_addresses4, addr4_link) {  in afs_find_server()
60 				alist = rcu_dereference(server->addresses);  in afs_find_server()
74 		server = NULL;  in afs_find_server()
77 		server = afs_maybe_use_server(server, afs_server_trace_get_by_addr);  in afs_find_server()
84 	return server;  in afs_find_server()
88  * Look up a server by its UUID and mark it active.
92 	struct afs_server *server = NULL;  in afs_find_server_by_uuid()  local
103 		if (server)  in afs_find_server_by_uuid()
104 			afs_unuse_server(net, server, afs_server_trace_put_uuid_rsq);  in afs_find_server_by_uuid()
105 		server = NULL;  in afs_find_server_by_uuid()
111 			server = rb_entry(p, struct afs_server, uuid_rb);  in afs_find_server_by_uuid()
113 			diff = memcmp(uuid, &server->uuid, sizeof(*uuid));  in afs_find_server_by_uuid()
119 				afs_use_server(server, afs_server_trace_get_by_uuid);  in afs_find_server_by_uuid()
123 			server = NULL;  in afs_find_server_by_uuid()
129 	_leave(" = %p", server);  in afs_find_server_by_uuid()
130 	return server;  in afs_find_server_by_uuid()
134  * Install a server record in the namespace tree.  If there's a clash, we stick
142 	struct afs_server *server, *next;  in afs_install_server()  local
151 	/* Firstly install the server in the UUID lookup tree */  in afs_install_server()
157 		server = rb_entry(p, struct afs_server, uuid_rb);  in afs_install_server()
158 		diff = memcmp(&candidate->uuid, &server->uuid, sizeof(uuid_t));  in afs_install_server()
164 			if (server->cell == cell)  in afs_install_server()
168 			 * different cells.  Append the new server to the list.  in afs_install_server()
172 					server->uuid_next,  in afs_install_server()
176 				server = next;  in afs_install_server()
178 			rcu_assign_pointer(server->uuid_next, candidate);  in afs_install_server()
179 			candidate->uuid_prev = server;  in afs_install_server()
180 			server = candidate;  in afs_install_server()
185 	server = candidate;  in afs_install_server()
186 	rb_link_node(&server->uuid_rb, p, pp);  in afs_install_server()
187 	rb_insert_color(&server->uuid_rb, &net->fs_servers);  in afs_install_server()
188 	hlist_add_head_rcu(&server->proc_link, &net->fs_proc);  in afs_install_server()
192 	alist = rcu_dereference_protected(server->addresses,  in afs_install_server()
195 	/* Secondly, if the server has any IPv4 and/or IPv6 addresses, install  in afs_install_server()
204 		hlist_add_head_rcu(&server->addr4_link, &net->fs_addresses4);  in afs_install_server()
206 		hlist_add_head_rcu(&server->addr6_link, &net->fs_addresses6);  in afs_install_server()
211 	afs_get_server(server, afs_server_trace_get_install);  in afs_install_server()
213 	return server;  in afs_install_server()
217  * Allocate a new server record and mark it active.
223 	struct afs_server *server;  in afs_alloc_server()  local
228 	server = kzalloc(sizeof(struct afs_server), GFP_KERNEL);  in afs_alloc_server()
229 	if (!server)  in afs_alloc_server()
232 	atomic_set(&server->ref, 1);  in afs_alloc_server()
233 	atomic_set(&server->active, 1);  in afs_alloc_server()
234 	server->debug_id = atomic_inc_return(&afs_server_debug_id);  in afs_alloc_server()
235 	RCU_INIT_POINTER(server->addresses, alist);  in afs_alloc_server()
236 	server->addr_version = alist->version;  in afs_alloc_server()
237 	server->uuid = *uuid;  in afs_alloc_server()
238 	rwlock_init(&server->fs_lock);  in afs_alloc_server()
239 	init_waitqueue_head(&server->probe_wq);  in afs_alloc_server()
240 	INIT_LIST_HEAD(&server->probe_link);  in afs_alloc_server()
241 	spin_lock_init(&server->probe_lock);  in afs_alloc_server()
242 	server->cell = cell;  in afs_alloc_server()
243 	server->rtt = UINT_MAX;  in afs_alloc_server()
246 	trace_afs_server(server, 1, 1, afs_server_trace_alloc);  in afs_alloc_server()
247 	_leave(" = %p", server);  in afs_alloc_server()
248 	return server;  in afs_alloc_server()
256  * Look up an address record for a server
268 			if (test_bit(AFS_VLSERVER_FL_IS_YFS, &vc.server->flags))  in afs_vl_lookup_addrs()
287 	struct afs_server *server, *candidate;  in afs_lookup_server()  local
291 	server = afs_find_server_by_uuid(cell->net, uuid);  in afs_lookup_server()
292 	if (server) {  in afs_lookup_server()
293 		if (server->addr_version != addr_version)  in afs_lookup_server()
294 			set_bit(AFS_SERVER_FL_NEEDS_UPDATE, &server->flags);  in afs_lookup_server()
295 		return server;  in afs_lookup_server()
308 	server = afs_install_server(cell, candidate);  in afs_lookup_server()
309 	if (server != candidate) {  in afs_lookup_server()
317 		afs_fs_probe_fileserver(cell->net, server, key, true);  in afs_lookup_server()
320 	return server;  in afs_lookup_server()
324  * Set the server timer to fire after a given delay, assuming it's not already
337  * Server management timer.  We have an increment on fs_outstanding that we
350  * Get a reference on a server object.
352 struct afs_server *afs_get_server(struct afs_server *server,  in afs_get_server()  argument
355 	unsigned int u = atomic_inc_return(&server->ref);  in afs_get_server()
357 	trace_afs_server(server, u, atomic_read(&server->active), reason);  in afs_get_server()
358 	return server;  in afs_get_server()
362  * Try to get a reference on a server object.
364 static struct afs_server *afs_maybe_use_server(struct afs_server *server,  in afs_maybe_use_server()  argument
367 	unsigned int r = atomic_fetch_add_unless(&server->ref, 1, 0);  in afs_maybe_use_server()
373 	a = atomic_inc_return(&server->active);  in afs_maybe_use_server()
374 	trace_afs_server(server, r, a, reason);  in afs_maybe_use_server()
375 	return server;  in afs_maybe_use_server()
379  * Get an active count on a server object.
381 struct afs_server *afs_use_server(struct afs_server *server, enum afs_server_trace reason)  in afs_use_server()  argument
383 	unsigned int r = atomic_inc_return(&server->ref);  in afs_use_server()
384 	unsigned int a = atomic_inc_return(&server->active);  in afs_use_server()
386 	trace_afs_server(server, r, a, reason);  in afs_use_server()
387 	return server;  in afs_use_server()
391  * Release a reference on a server record.
393 void afs_put_server(struct afs_net *net, struct afs_server *server,  in afs_put_server()  argument
398 	if (!server)  in afs_put_server()
401 	usage = atomic_dec_return(&server->ref);  in afs_put_server()
402 	trace_afs_server(server, usage, atomic_read(&server->active), reason);  in afs_put_server()
404 		__afs_put_server(net, server);  in afs_put_server()
408  * Drop an active count on a server object without updating the last-unused
411 void afs_unuse_server_notime(struct afs_net *net, struct afs_server *server,  in afs_unuse_server_notime()  argument
414 	if (server) {  in afs_unuse_server_notime()
415 		unsigned int active = atomic_dec_return(&server->active);  in afs_unuse_server_notime()
419 		afs_put_server(net, server, reason);  in afs_unuse_server_notime()
424  * Drop an active count on a server object.
426 void afs_unuse_server(struct afs_net *net, struct afs_server *server,  in afs_unuse_server()  argument
429 	if (server) {  in afs_unuse_server()
430 		server->unuse_time = ktime_get_real_seconds();  in afs_unuse_server()
431 		afs_unuse_server_notime(net, server, reason);  in afs_unuse_server()
437 	struct afs_server *server = container_of(rcu, struct afs_server, rcu);  in afs_server_rcu()  local
439 	trace_afs_server(server, atomic_read(&server->ref),  in afs_server_rcu()
440 			 atomic_read(&server->active), afs_server_trace_free);  in afs_server_rcu()
441 	afs_put_addrlist(rcu_access_pointer(server->addresses));  in afs_server_rcu()
442 	kfree(server);  in afs_server_rcu()
445 static void __afs_put_server(struct afs_net *net, struct afs_server *server)  in __afs_put_server()  argument
447 	call_rcu(&server->rcu, afs_server_rcu);  in __afs_put_server()
451 static void afs_give_up_callbacks(struct afs_net *net, struct afs_server *server)  in afs_give_up_callbacks()  argument
453 	struct afs_addr_list *alist = rcu_access_pointer(server->addresses);  in afs_give_up_callbacks()
460 	afs_fs_give_up_all_callbacks(net, server, &ac, NULL);  in afs_give_up_callbacks()
464  * destroy a dead server
466 static void afs_destroy_server(struct afs_net *net, struct afs_server *server)  in afs_destroy_server()  argument
468 	if (test_bit(AFS_SERVER_FL_MAY_HAVE_CB, &server->flags))  in afs_destroy_server()
469 		afs_give_up_callbacks(net, server);  in afs_destroy_server()
471 	afs_put_server(net, server, afs_server_trace_destroy);  in afs_destroy_server()
479 	struct afs_server *server, *next, *prev;  in afs_gc_servers()  local
482 	while ((server = gc_list)) {  in afs_gc_servers()
483 		gc_list = server->gc_next;  in afs_gc_servers()
487 		active = atomic_read(&server->active);  in afs_gc_servers()
489 			trace_afs_server(server, atomic_read(&server->ref),  in afs_gc_servers()
492 				server->uuid_next, lockdep_is_held(&net->fs_lock.lock));  in afs_gc_servers()
493 			prev = server->uuid_prev;  in afs_gc_servers()
497 					rb_erase(&server->uuid_rb, &net->fs_servers);  in afs_gc_servers()
499 					rb_replace_node_rcu(&server->uuid_rb,  in afs_gc_servers()
505 				/* This server is not at the front */  in afs_gc_servers()
511 			list_del(&server->probe_link);  in afs_gc_servers()
512 			hlist_del_rcu(&server->proc_link);  in afs_gc_servers()
513 			if (!hlist_unhashed(&server->addr4_link))  in afs_gc_servers()
514 				hlist_del_rcu(&server->addr4_link);  in afs_gc_servers()
515 			if (!hlist_unhashed(&server->addr6_link))  in afs_gc_servers()
516 				hlist_del_rcu(&server->addr6_link);  in afs_gc_servers()
521 			afs_destroy_server(net, server);  in afs_gc_servers()
542 	/* Trawl the server list looking for servers that have expired from  in afs_manage_servers()
548 		struct afs_server *server =  in afs_manage_servers()  local
550 		int active = atomic_read(&server->active);  in afs_manage_servers()
552 		_debug("manage %pU %u", &server->uuid, active);  in afs_manage_servers()
555 			trace_afs_server(server, atomic_read(&server->ref),  in afs_manage_servers()
558 				pr_notice("Can't purge s=%08x\n", server->debug_id);  in afs_manage_servers()
562 			time64_t expire_at = server->unuse_time;  in afs_manage_servers()
564 			if (!test_bit(AFS_SERVER_FL_VL_FAIL, &server->flags) &&  in afs_manage_servers()
565 			    !test_bit(AFS_SERVER_FL_NOT_FOUND, &server->flags))  in afs_manage_servers()
568 				server->gc_next = gc_list;  in afs_manage_servers()
569 				gc_list = server;  in afs_manage_servers()
626  * Get an update for a server's address list.
629 					      struct afs_server *server)  in afs_update_server_record()  argument
635 	trace_afs_server(server, atomic_read(&server->ref), atomic_read(&server->active),  in afs_update_server_record()
638 	alist = afs_vl_lookup_addrs(op->volume->cell, op->key, &server->uuid);  in afs_update_server_record()
643 		    server->addresses) {  in afs_update_server_record()
653 	if (server->addr_version != alist->version) {  in afs_update_server_record()
654 		write_lock(&server->fs_lock);  in afs_update_server_record()
655 		discard = rcu_dereference_protected(server->addresses,  in afs_update_server_record()
656 						    lockdep_is_held(&server->fs_lock));  in afs_update_server_record()
657 		rcu_assign_pointer(server->addresses, alist);  in afs_update_server_record()
658 		server->addr_version = alist->version;  in afs_update_server_record()
659 		write_unlock(&server->fs_lock);  in afs_update_server_record()
668  * See if a server's address list needs updating.
670 bool afs_check_server_record(struct afs_operation *op, struct afs_server *server)  in afs_check_server_record()  argument
677 	ASSERT(server);  in afs_check_server_record()
680 	if (test_bit(AFS_SERVER_FL_UPDATING, &server->flags))  in afs_check_server_record()
682 	if (test_bit(AFS_SERVER_FL_NEEDS_UPDATE, &server->flags))  in afs_check_server_record()
688 	if (!test_and_set_bit_lock(AFS_SERVER_FL_UPDATING, &server->flags)) {  in afs_check_server_record()
689 		clear_bit(AFS_SERVER_FL_NEEDS_UPDATE, &server->flags);  in afs_check_server_record()
690 		success = afs_update_server_record(op, server);  in afs_check_server_record()
691 		clear_bit_unlock(AFS_SERVER_FL_UPDATING, &server->flags);  in afs_check_server_record()
692 		wake_up_bit(&server->flags, AFS_SERVER_FL_UPDATING);  in afs_check_server_record()
698 	ret = wait_on_bit(&server->flags, AFS_SERVER_FL_UPDATING,  in afs_check_server_record()