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2024-02-20 ea08eeccae9297f7aabd2ef7f0c2517ac4549acc 
 kernel/fs/afs/server.c
....@@ -1,32 +1,22 @@
1
+// SPDX-License-Identifier: GPL-2.0-or-later
12 /* AFS server record management
23  *
34  * Copyright (C) 2002, 2007 Red Hat, Inc. All Rights Reserved.
45  * Written by David Howells (dhowells@redhat.com)
5
- *
6
- * This program is free software; you can redistribute it and/or
7
- * modify it under the terms of the GNU General Public License
8
- * as published by the Free Software Foundation; either version
9
- * 2 of the License, or (at your option) any later version.
106  */
117 
128 #include <linux/sched.h>
139 #include <linux/slab.h>
1410 #include "afs_fs.h"
1511 #include "internal.h"
12
+#include "protocol_yfs.h"
1613 
1714 static unsigned afs_server_gc_delay = 10;	/* Server record timeout in seconds */
18
-static unsigned afs_server_update_delay = 30;	/* Time till VLDB recheck in secs */
15
+static atomic_t afs_server_debug_id;
1916 
20
-static void afs_inc_servers_outstanding(struct afs_net *net)
21
-{
22
-	atomic_inc(&net->servers_outstanding);
23
-}
24
-
25
-static void afs_dec_servers_outstanding(struct afs_net *net)
26
-{
27
-	if (atomic_dec_and_test(&net->servers_outstanding))
28
-		wake_up_var(&net->servers_outstanding);
29
-}
17
+static struct afs_server *afs_maybe_use_server(struct afs_server *,
18
+					       enum afs_server_trace);
19
+static void __afs_put_server(struct afs_net *, struct afs_server *);
3020 
3121 /*
3222  * Find a server by one of its addresses.
....@@ -43,7 +33,7 @@
4333 
4434 	do {
4535 		if (server)
46
-			afs_put_server(net, server);
36
+			afs_unuse_server_notime(net, server, afs_server_trace_put_find_rsq);
4737 		server = NULL;
4838 		read_seqbegin_or_lock(&net->fs_addr_lock, &seq);
4939 
....@@ -81,9 +71,9 @@
8171 		}
8272 
8373 		server = NULL;
74
+		continue;
8475 	found:
85
-		if (server && !atomic_inc_not_zero(&server->usage))
86
-			server = NULL;
76
+		server = afs_maybe_use_server(server, afs_server_trace_get_by_addr);
8777 
8878 	} while (need_seqretry(&net->fs_addr_lock, seq));
8979 
....@@ -94,7 +84,7 @@
9484 }
9585 
9686 /*
97
- * Look up a server by its UUID
87
+ * Look up a server by its UUID and mark it active.
9888  */
9989 struct afs_server *afs_find_server_by_uuid(struct afs_net *net, const uuid_t *uuid)
10090 {
....@@ -110,7 +100,7 @@
110100 		 * changes.
111101 		 */
112102 		if (server)
113
-			afs_put_server(net, server);
103
+			afs_unuse_server(net, server, afs_server_trace_put_uuid_rsq);
114104 		server = NULL;
115105 
116106 		read_seqbegin_or_lock(&net->fs_lock, &seq);
....@@ -125,7 +115,7 @@
125115 			} else if (diff > 0) {
126116 				p = p->rb_right;
127117 			} else {
128
-				afs_get_server(server);
118
+				afs_use_server(server, afs_server_trace_get_by_uuid);
129119 				break;
130120 			}
131121 
....@@ -140,15 +130,18 @@
140130 }
141131 
142132 /*
143
- * Install a server record in the namespace tree
133
+ * Install a server record in the namespace tree.  If there's a clash, we stick
134
+ * it into a list anchored on whichever afs_server struct is actually in the
135
+ * tree.
144136  */
145
-static struct afs_server *afs_install_server(struct afs_net *net,
137
+static struct afs_server *afs_install_server(struct afs_cell *cell,
146138 					     struct afs_server *candidate)
147139 {
148140 	const struct afs_addr_list *alist;
149
-	struct afs_server *server;
141
+	struct afs_server *server, *next;
142
+	struct afs_net *net = cell->net;
150143 	struct rb_node **pp, *p;
151
-	int ret = -EEXIST, diff;
144
+	int diff;
152145 
153146 	_enter("%p", candidate);
154147 
....@@ -162,12 +155,30 @@
162155 		_debug("- consider %p", p);
163156 		server = rb_entry(p, struct afs_server, uuid_rb);
164157 		diff = memcmp(&candidate->uuid, &server->uuid, sizeof(uuid_t));
165
-		if (diff < 0)
158
+		if (diff < 0) {
166159 			pp = &(*pp)->rb_left;
167
-		else if (diff > 0)
160
+		} else if (diff > 0) {
168161 			pp = &(*pp)->rb_right;
169
-		else
170
-			goto exists;
162
+		} else {
163
+			if (server->cell == cell)
164
+				goto exists;
165
+
166
+			/* We have the same UUID representing servers in
167
+			 * different cells.  Append the new server to the list.
168
+			 */
169
+			for (;;) {
170
+				next = rcu_dereference_protected(
171
+					server->uuid_next,
172
+					lockdep_is_held(&net->fs_lock.lock));
173
+				if (!next)
174
+					break;
175
+				server = next;
176
+			}
177
+			rcu_assign_pointer(server->uuid_next, candidate);
178
+			candidate->uuid_prev = server;
179
+			server = candidate;
180
+			goto added_dup;
181
+		}
171182 	}
172183 
173184 	server = candidate;
....@@ -175,6 +186,7 @@
175186 	rb_insert_color(&server->uuid_rb, &net->fs_servers);
176187 	hlist_add_head_rcu(&server->proc_link, &net->fs_proc);
177188 
189
+added_dup:
178190 	write_seqlock(&net->fs_addr_lock);
179191 	alist = rcu_dereference_protected(server->addresses,
180192 					  lockdep_is_held(&net->fs_addr_lock.lock));
....@@ -193,22 +205,22 @@
193205 		hlist_add_head_rcu(&server->addr6_link, &net->fs_addresses6);
194206 
195207 	write_sequnlock(&net->fs_addr_lock);
196
-	ret = 0;
197208 
198209 exists:
199
-	afs_get_server(server);
210
+	afs_get_server(server, afs_server_trace_get_install);
200211 	write_sequnlock(&net->fs_lock);
201212 	return server;
202213 }
203214 
204215 /*
205
- * allocate a new server record
216
+ * Allocate a new server record and mark it active.
206217  */
207
-static struct afs_server *afs_alloc_server(struct afs_net *net,
218
+static struct afs_server *afs_alloc_server(struct afs_cell *cell,
208219 					   const uuid_t *uuid,
209220 					   struct afs_addr_list *alist)
210221 {
211222 	struct afs_server *server;
223
+	struct afs_net *net = cell->net;
212224 
213225 	_enter("");
214226 
....@@ -216,17 +228,21 @@
216228 	if (!server)
217229 		goto enomem;
218230 
219
-	atomic_set(&server->usage, 1);
231
+	atomic_set(&server->ref, 1);
232
+	atomic_set(&server->active, 1);
233
+	server->debug_id = atomic_inc_return(&afs_server_debug_id);
220234 	RCU_INIT_POINTER(server->addresses, alist);
221235 	server->addr_version = alist->version;
222236 	server->uuid = *uuid;
223
-	server->flags = (1UL << AFS_SERVER_FL_NEW);
224
-	server->update_at = ktime_get_real_seconds() + afs_server_update_delay;
225237 	rwlock_init(&server->fs_lock);
226
-	INIT_HLIST_HEAD(&server->cb_volumes);
227
-	rwlock_init(&server->cb_break_lock);
238
+	init_waitqueue_head(&server->probe_wq);
239
+	INIT_LIST_HEAD(&server->probe_link);
240
+	spin_lock_init(&server->probe_lock);
241
+	server->cell = cell;
242
+	server->rtt = UINT_MAX;
228243 
229244 	afs_inc_servers_outstanding(net);
245
+	trace_afs_server(server, 1, 1, afs_server_trace_alloc);
230246 	_leave(" = %p", server);
231247 	return server;
232248 
....@@ -241,48 +257,30 @@
241257 static struct afs_addr_list *afs_vl_lookup_addrs(struct afs_cell *cell,
242258 						 struct key *key, const uuid_t *uuid)
243259 {
244
-	struct afs_addr_cursor ac;
245
-	struct afs_addr_list *alist;
260
+	struct afs_vl_cursor vc;
261
+	struct afs_addr_list *alist = NULL;
246262 	int ret;
247263 
248
-	ret = afs_set_vl_cursor(&ac, cell);
249
-	if (ret < 0)
250
-		return ERR_PTR(ret);
251
-
252
-	while (afs_iterate_addresses(&ac)) {
253
-		if (test_bit(ac.index, &ac.alist->yfs))
254
-			alist = afs_yfsvl_get_endpoints(cell->net, &ac, key, uuid);
255
-		else
256
-			alist = afs_vl_get_addrs_u(cell->net, &ac, key, uuid);
257
-		switch (ac.error) {
258
-		case 0:
259
-			afs_end_cursor(&ac);
260
-			return alist;
261
-		case -ECONNABORTED:
262
-			ac.error = afs_abort_to_error(ac.abort_code);
263
-			goto error;
264
-		case -ENOMEM:
265
-		case -ENONET:
266
-			goto error;
267
-		case -ENETUNREACH:
268
-		case -EHOSTUNREACH:
269
-		case -ECONNREFUSED:
270
-			break;
271
-		default:
272
-			ac.error = -EIO;
273
-			goto error;
264
+	ret = -ERESTARTSYS;
265
+	if (afs_begin_vlserver_operation(&vc, cell, key)) {
266
+		while (afs_select_vlserver(&vc)) {
267
+			if (test_bit(AFS_VLSERVER_FL_IS_YFS, &vc.server->flags))
268
+				alist = afs_yfsvl_get_endpoints(&vc, uuid);
269
+			else
270
+				alist = afs_vl_get_addrs_u(&vc, uuid);
274271 		}
272
+
273
+		ret = afs_end_vlserver_operation(&vc);
275274 	}
276275 
277
-error:
278
-	return ERR_PTR(afs_end_cursor(&ac));
276
+	return ret < 0 ? ERR_PTR(ret) : alist;
279277 }
280278 
281279 /*
282280  * Get or create a fileserver record.
283281  */
284282 struct afs_server *afs_lookup_server(struct afs_cell *cell, struct key *key,
285
-				     const uuid_t *uuid)
283
+				     const uuid_t *uuid, u32 addr_version)
286284 {
287285 	struct afs_addr_list *alist;
288286 	struct afs_server *server, *candidate;
....@@ -290,26 +288,34 @@
290288 	_enter("%p,%pU", cell->net, uuid);
291289 
292290 	server = afs_find_server_by_uuid(cell->net, uuid);
293
-	if (server)
291
+	if (server) {
292
+		if (server->addr_version != addr_version)
293
+			set_bit(AFS_SERVER_FL_NEEDS_UPDATE, &server->flags);
294294 		return server;
295
+	}
295296 
296297 	alist = afs_vl_lookup_addrs(cell, key, uuid);
297298 	if (IS_ERR(alist))
298299 		return ERR_CAST(alist);
299300 
300
-	candidate = afs_alloc_server(cell->net, uuid, alist);
301
+	candidate = afs_alloc_server(cell, uuid, alist);
301302 	if (!candidate) {
302303 		afs_put_addrlist(alist);
303304 		return ERR_PTR(-ENOMEM);
304305 	}
305306 
306
-	server = afs_install_server(cell->net, candidate);
307
+	server = afs_install_server(cell, candidate);
307308 	if (server != candidate) {
308309 		afs_put_addrlist(alist);
309310 		kfree(candidate);
311
+	} else {
312
+		/* Immediately dispatch an asynchronous probe to each interface
313
+		 * on the fileserver.  This will make sure the repeat-probing
314
+		 * service is started.
315
+		 */
316
+		afs_fs_probe_fileserver(cell->net, server, key, true);
310317 	}
311318 
312
-	_leave(" = %p{%d}", server, atomic_read(&server->usage));
313319 	return server;
314320 }
315321 
....@@ -340,33 +346,117 @@
340346 }
341347 
342348 /*
349
+ * Get a reference on a server object.
350
+ */
351
+struct afs_server *afs_get_server(struct afs_server *server,
352
+				  enum afs_server_trace reason)
353
+{
354
+	unsigned int u = atomic_inc_return(&server->ref);
355
+
356
+	trace_afs_server(server, u, atomic_read(&server->active), reason);
357
+	return server;
358
+}
359
+
360
+/*
361
+ * Try to get a reference on a server object.
362
+ */
363
+static struct afs_server *afs_maybe_use_server(struct afs_server *server,
364
+					       enum afs_server_trace reason)
365
+{
366
+	unsigned int r = atomic_fetch_add_unless(&server->ref, 1, 0);
367
+	unsigned int a;
368
+
369
+	if (r == 0)
370
+		return NULL;
371
+
372
+	a = atomic_inc_return(&server->active);
373
+	trace_afs_server(server, r, a, reason);
374
+	return server;
375
+}
376
+
377
+/*
378
+ * Get an active count on a server object.
379
+ */
380
+struct afs_server *afs_use_server(struct afs_server *server, enum afs_server_trace reason)
381
+{
382
+	unsigned int r = atomic_inc_return(&server->ref);
383
+	unsigned int a = atomic_inc_return(&server->active);
384
+
385
+	trace_afs_server(server, r, a, reason);
386
+	return server;
387
+}
388
+
389
+/*
343390  * Release a reference on a server record.
344391  */
345
-void afs_put_server(struct afs_net *net, struct afs_server *server)
392
+void afs_put_server(struct afs_net *net, struct afs_server *server,
393
+		    enum afs_server_trace reason)
346394 {
347395 	unsigned int usage;
348396 
349397 	if (!server)
350398 		return;
351399 
352
-	server->put_time = ktime_get_real_seconds();
400
+	usage = atomic_dec_return(&server->ref);
401
+	trace_afs_server(server, usage, atomic_read(&server->active), reason);
402
+	if (unlikely(usage == 0))
403
+		__afs_put_server(net, server);
404
+}
353405 
354
-	usage = atomic_dec_return(&server->usage);
406
+/*
407
+ * Drop an active count on a server object without updating the last-unused
408
+ * time.
409
+ */
410
+void afs_unuse_server_notime(struct afs_net *net, struct afs_server *server,
411
+			     enum afs_server_trace reason)
412
+{
413
+	if (server) {
414
+		unsigned int active = atomic_dec_return(&server->active);
355415 
356
-	_enter("{%u}", usage);
416
+		if (active == 0)
417
+			afs_set_server_timer(net, afs_server_gc_delay);
418
+		afs_put_server(net, server, reason);
419
+	}
420
+}
357421 
358
-	if (likely(usage > 0))
359
-		return;
360
-
361
-	afs_set_server_timer(net, afs_server_gc_delay);
422
+/*
423
+ * Drop an active count on a server object.
424
+ */
425
+void afs_unuse_server(struct afs_net *net, struct afs_server *server,
426
+		      enum afs_server_trace reason)
427
+{
428
+	if (server) {
429
+		server->unuse_time = ktime_get_real_seconds();
430
+		afs_unuse_server_notime(net, server, reason);
431
+	}
362432 }
363433 
364434 static void afs_server_rcu(struct rcu_head *rcu)
365435 {
366436 	struct afs_server *server = container_of(rcu, struct afs_server, rcu);
367437 
438
+	trace_afs_server(server, atomic_read(&server->ref),
439
+			 atomic_read(&server->active), afs_server_trace_free);
368440 	afs_put_addrlist(rcu_access_pointer(server->addresses));
369441 	kfree(server);
442
+}
443
+
444
+static void __afs_put_server(struct afs_net *net, struct afs_server *server)
445
+{
446
+	call_rcu(&server->rcu, afs_server_rcu);
447
+	afs_dec_servers_outstanding(net);
448
+}
449
+
450
+static void afs_give_up_callbacks(struct afs_net *net, struct afs_server *server)
451
+{
452
+	struct afs_addr_list *alist = rcu_access_pointer(server->addresses);
453
+	struct afs_addr_cursor ac = {
454
+		.alist	= alist,
455
+		.index	= alist->preferred,
456
+		.error	= 0,
457
+	};
458
+
459
+	afs_fs_give_up_all_callbacks(net, server, &ac, NULL);
370460 }
371461 
372462 /*
....@@ -374,21 +464,10 @@
374464  */
375465 static void afs_destroy_server(struct afs_net *net, struct afs_server *server)
376466 {
377
-	struct afs_addr_list *alist = rcu_access_pointer(server->addresses);
378
-	struct afs_addr_cursor ac = {
379
-		.alist	= alist,
380
-		.start	= alist->index,
381
-		.index	= 0,
382
-		.addr	= &alist->addrs[alist->index],
383
-		.error	= 0,
384
-	};
385
-	_enter("%p", server);
386
-
387467 	if (test_bit(AFS_SERVER_FL_MAY_HAVE_CB, &server->flags))
388
-		afs_fs_give_up_all_callbacks(net, server, &ac, NULL);
468
+		afs_give_up_callbacks(net, server);
389469 
390
-	call_rcu(&server->rcu, afs_server_rcu);
391
-	afs_dec_servers_outstanding(net);
470
+	afs_put_server(net, server, afs_server_trace_destroy);
392471 }
393472 
394473 /*
....@@ -396,31 +475,49 @@
396475  */
397476 static void afs_gc_servers(struct afs_net *net, struct afs_server *gc_list)
398477 {
399
-	struct afs_server *server;
400
-	bool deleted;
401
-	int usage;
478
+	struct afs_server *server, *next, *prev;
479
+	int active;
402480 
403481 	while ((server = gc_list)) {
404482 		gc_list = server->gc_next;
405483 
406484 		write_seqlock(&net->fs_lock);
407
-		usage = 1;
408
-		deleted = atomic_try_cmpxchg(&server->usage, &usage, 0);
409
-		if (deleted) {
410
-			rb_erase(&server->uuid_rb, &net->fs_servers);
411
-			hlist_del_rcu(&server->proc_link);
412
-		}
413
-		write_sequnlock(&net->fs_lock);
414485 
415
-		if (deleted) {
416
-			write_seqlock(&net->fs_addr_lock);
486
+		active = atomic_read(&server->active);
487
+		if (active == 0) {
488
+			trace_afs_server(server, atomic_read(&server->ref),
489
+					 active, afs_server_trace_gc);
490
+			next = rcu_dereference_protected(
491
+				server->uuid_next, lockdep_is_held(&net->fs_lock.lock));
492
+			prev = server->uuid_prev;
493
+			if (!prev) {
494
+				/* The one at the front is in the tree */
495
+				if (!next) {
496
+					rb_erase(&server->uuid_rb, &net->fs_servers);
497
+				} else {
498
+					rb_replace_node_rcu(&server->uuid_rb,
499
+							    &next->uuid_rb,
500
+							    &net->fs_servers);
501
+					next->uuid_prev = NULL;
502
+				}
503
+			} else {
504
+				/* This server is not at the front */
505
+				rcu_assign_pointer(prev->uuid_next, next);
506
+				if (next)
507
+					next->uuid_prev = prev;
508
+			}
509
+
510
+			list_del(&server->probe_link);
511
+			hlist_del_rcu(&server->proc_link);
417512 			if (!hlist_unhashed(&server->addr4_link))
418513 				hlist_del_rcu(&server->addr4_link);
419514 			if (!hlist_unhashed(&server->addr6_link))
420515 				hlist_del_rcu(&server->addr6_link);
421
-			write_sequnlock(&net->fs_addr_lock);
422
-			afs_destroy_server(net, server);
423516 		}
517
+		write_sequnlock(&net->fs_lock);
518
+
519
+		if (active == 0)
520
+			afs_destroy_server(net, server);
424521 	}
425522 }
426523 
....@@ -449,15 +546,19 @@
449546 	for (cursor = rb_first(&net->fs_servers); cursor; cursor = rb_next(cursor)) {
450547 		struct afs_server *server =
451548 			rb_entry(cursor, struct afs_server, uuid_rb);
452
-		int usage = atomic_read(&server->usage);
549
+		int active = atomic_read(&server->active);
453550 
454
-		_debug("manage %pU %u", &server->uuid, usage);
551
+		_debug("manage %pU %u", &server->uuid, active);
455552 
456
-		ASSERTCMP(usage, >=, 1);
457
-		ASSERTIFCMP(purging, usage, ==, 1);
553
+		if (purging) {
554
+			trace_afs_server(server, atomic_read(&server->ref),
555
+					 active, afs_server_trace_purging);
556
+			if (active != 0)
557
+				pr_notice("Can't purge s=%08x\n", server->debug_id);
558
+		}
458559 
459
-		if (usage == 1) {
460
-			time64_t expire_at = server->put_time;
560
+		if (active == 0) {
561
+			time64_t expire_at = server->unuse_time;
461562 
462563 			if (!test_bit(AFS_SERVER_FL_VL_FAIL, &server->flags) &&
463564 			    !test_bit(AFS_SERVER_FL_NOT_FOUND, &server->flags))
....@@ -509,123 +610,41 @@
509610 	_enter("");
510611 
511612 	if (del_timer_sync(&net->fs_timer))
512
-		atomic_dec(&net->servers_outstanding);
613
+		afs_dec_servers_outstanding(net);
513614 
514615 	afs_queue_server_manager(net);
515616 
516617 	_debug("wait");
618
+	atomic_dec(&net->servers_outstanding);
517619 	wait_var_event(&net->servers_outstanding,
518620 		       !atomic_read(&net->servers_outstanding));
519621 	_leave("");
520622 }
521623 
522624 /*
523
- * Probe a fileserver to find its capabilities.
524
- *
525
- * TODO: Try service upgrade.
526
- */
527
-static bool afs_do_probe_fileserver(struct afs_fs_cursor *fc)
528
-{
529
-	_enter("");
530
-
531
-	fc->ac.addr = NULL;
532
-	fc->ac.start = READ_ONCE(fc->ac.alist->index);
533
-	fc->ac.index = fc->ac.start;
534
-	fc->ac.error = 0;
535
-	fc->ac.begun = false;
536
-
537
-	while (afs_iterate_addresses(&fc->ac)) {
538
-		afs_fs_get_capabilities(afs_v2net(fc->vnode), fc->cbi->server,
539
-					&fc->ac, fc->key);
540
-		switch (fc->ac.error) {
541
-		case 0:
542
-			afs_end_cursor(&fc->ac);
543
-			set_bit(AFS_SERVER_FL_PROBED, &fc->cbi->server->flags);
544
-			return true;
545
-		case -ECONNABORTED:
546
-			fc->ac.error = afs_abort_to_error(fc->ac.abort_code);
547
-			goto error;
548
-		case -ENOMEM:
549
-		case -ENONET:
550
-			goto error;
551
-		case -ENETUNREACH:
552
-		case -EHOSTUNREACH:
553
-		case -ECONNREFUSED:
554
-		case -ETIMEDOUT:
555
-		case -ETIME:
556
-			break;
557
-		default:
558
-			fc->ac.error = -EIO;
559
-			goto error;
560
-		}
561
-	}
562
-
563
-error:
564
-	afs_end_cursor(&fc->ac);
565
-	return false;
566
-}
567
-
568
-/*
569
- * If we haven't already, try probing the fileserver to get its capabilities.
570
- * We try not to instigate parallel probes, but it's possible that the parallel
571
- * probes will fail due to authentication failure when ours would succeed.
572
- *
573
- * TODO: Try sending an anonymous probe if an authenticated probe fails.
574
- */
575
-bool afs_probe_fileserver(struct afs_fs_cursor *fc)
576
-{
577
-	bool success;
578
-	int ret, retries = 0;
579
-
580
-	_enter("");
581
-
582
-retry:
583
-	if (test_bit(AFS_SERVER_FL_PROBED, &fc->cbi->server->flags)) {
584
-		_leave(" = t");
585
-		return true;
586
-	}
587
-
588
-	if (!test_and_set_bit_lock(AFS_SERVER_FL_PROBING, &fc->cbi->server->flags)) {
589
-		success = afs_do_probe_fileserver(fc);
590
-		clear_bit_unlock(AFS_SERVER_FL_PROBING, &fc->cbi->server->flags);
591
-		wake_up_bit(&fc->cbi->server->flags, AFS_SERVER_FL_PROBING);
592
-		_leave(" = t");
593
-		return success;
594
-	}
595
-
596
-	_debug("wait");
597
-	ret = wait_on_bit(&fc->cbi->server->flags, AFS_SERVER_FL_PROBING,
598
-			  TASK_INTERRUPTIBLE);
599
-	if (ret == -ERESTARTSYS) {
600
-		fc->ac.error = ret;
601
-		_leave(" = f [%d]", ret);
602
-		return false;
603
-	}
604
-
605
-	retries++;
606
-	if (retries == 4) {
607
-		fc->ac.error = -ESTALE;
608
-		_leave(" = f [stale]");
609
-		return false;
610
-	}
611
-	_debug("retry");
612
-	goto retry;
613
-}
614
-
615
-/*
616625  * Get an update for a server's address list.
617626  */
618
-static noinline bool afs_update_server_record(struct afs_fs_cursor *fc, struct afs_server *server)
627
+static noinline bool afs_update_server_record(struct afs_operation *op,
628
+					      struct afs_server *server)
619629 {
620630 	struct afs_addr_list *alist, *discard;
621631 
622632 	_enter("");
623633 
624
-	alist = afs_vl_lookup_addrs(fc->vnode->volume->cell, fc->key,
625
-				    &server->uuid);
634
+	trace_afs_server(server, atomic_read(&server->ref), atomic_read(&server->active),
635
+			 afs_server_trace_update);
636
+
637
+	alist = afs_vl_lookup_addrs(op->volume->cell, op->key, &server->uuid);
626638 	if (IS_ERR(alist)) {
627
-		fc->ac.error = PTR_ERR(alist);
628
-		_leave(" = f [%d]", fc->ac.error);
639
+		if ((PTR_ERR(alist) == -ERESTARTSYS ||
640
+		     PTR_ERR(alist) == -EINTR) &&
641
+		    (op->flags & AFS_OPERATION_UNINTR) &&
642
+		    server->addresses) {
643
+			_leave(" = t [intr]");
644
+			return true;
645
+		}
646
+		op->error = PTR_ERR(alist);
647
+		_leave(" = f [%d]", op->error);
629648 		return false;
630649 	}
631650 
....@@ -639,7 +658,6 @@
639658 		write_unlock(&server->fs_lock);
640659 	}
641660 
642
-	server->update_at = ktime_get_real_seconds() + afs_server_update_delay;
643661 	afs_put_addrlist(discard);
644662 	_leave(" = t");
645663 	return true;
....@@ -648,10 +666,8 @@
648666 /*
649667  * See if a server's address list needs updating.
650668  */
651
-bool afs_check_server_record(struct afs_fs_cursor *fc, struct afs_server *server)
669
+bool afs_check_server_record(struct afs_operation *op, struct afs_server *server)
652670 {
653
-	time64_t now = ktime_get_real_seconds();
654
-	long diff;
655671 	bool success;
656672 	int ret, retries = 0;
657673 
....@@ -660,24 +676,29 @@
660676 	ASSERT(server);
661677 
662678 retry:
663
-	diff = READ_ONCE(server->update_at) - now;
664
-	if (diff > 0) {
665
-		_leave(" = t [not now %ld]", diff);
666
-		return true;
667
-	}
679
+	if (test_bit(AFS_SERVER_FL_UPDATING, &server->flags))
680
+		goto wait;
681
+	if (test_bit(AFS_SERVER_FL_NEEDS_UPDATE, &server->flags))
682
+		goto update;
683
+	_leave(" = t [good]");
684
+	return true;
668685 
686
+update:
669687 	if (!test_and_set_bit_lock(AFS_SERVER_FL_UPDATING, &server->flags)) {
670
-		success = afs_update_server_record(fc, server);
688
+		clear_bit(AFS_SERVER_FL_NEEDS_UPDATE, &server->flags);
689
+		success = afs_update_server_record(op, server);
671690 		clear_bit_unlock(AFS_SERVER_FL_UPDATING, &server->flags);
672691 		wake_up_bit(&server->flags, AFS_SERVER_FL_UPDATING);
673692 		_leave(" = %d", success);
674693 		return success;
675694 	}
676695 
696
+wait:
677697 	ret = wait_on_bit(&server->flags, AFS_SERVER_FL_UPDATING,
678
-			  TASK_INTERRUPTIBLE);
698
+			  (op->flags & AFS_OPERATION_UNINTR) ?
699
+			  TASK_UNINTERRUPTIBLE : TASK_INTERRUPTIBLE);
679700 	if (ret == -ERESTARTSYS) {
680
-		fc->ac.error = ret;
701
+		op->error = ret;
681702 		_leave(" = f [intr]");
682703 		return false;
683704 	}