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1// SPDX-License-Identifier: GPL-2.0-or-later
2/* Handle fileserver selection and rotation.
3 *
4 * Copyright (C) 2017 Red Hat, Inc. All Rights Reserved.
5 * Written by David Howells (dhowells@redhat.com)
6 */
7
8#include <linux/kernel.h>
9#include <linux/slab.h>
10#include <linux/fs.h>
11#include <linux/sched.h>
12#include <linux/delay.h>
13#include <linux/sched/signal.h>
14#include "internal.h"
15#include "afs_fs.h"
16#include "protocol_uae.h"
17
18void afs_clear_server_states(struct afs_operation *op)
19{
20 unsigned int i;
21
22 if (op->server_states) {
23 for (i = 0; i < op->server_list->nr_servers; i++)
24 afs_put_endpoint_state(op->server_states[i].endpoint_state,
25 afs_estate_trace_put_server_state);
26 kfree(op->server_states);
27 }
28}
29
30/*
31 * Begin iteration through a server list, starting with the vnode's last used
32 * server if possible, or the last recorded good server if not.
33 */
34static bool afs_start_fs_iteration(struct afs_operation *op,
35 struct afs_vnode *vnode)
36{
37 struct afs_server *server;
38 void *cb_server;
39 int i;
40
41 trace_afs_rotate(op, afs_rotate_trace_start, 0);
42
43 read_lock(&op->volume->servers_lock);
44 op->server_list = afs_get_serverlist(
45 rcu_dereference_protected(op->volume->servers,
46 lockdep_is_held(&op->volume->servers_lock)));
47 read_unlock(&op->volume->servers_lock);
48
49 op->server_states = kcalloc(op->server_list->nr_servers, sizeof(op->server_states[0]),
50 GFP_KERNEL);
51 if (!op->server_states) {
52 afs_op_nomem(op);
53 trace_afs_rotate(op, afs_rotate_trace_nomem, 0);
54 return false;
55 }
56
57 rcu_read_lock();
58 for (i = 0; i < op->server_list->nr_servers; i++) {
59 struct afs_endpoint_state *estate;
60 struct afs_server_state *s = &op->server_states[i];
61
62 server = op->server_list->servers[i].server;
63 estate = rcu_dereference(server->endpoint_state);
64 s->endpoint_state = afs_get_endpoint_state(estate,
65 afs_estate_trace_get_server_state);
66 s->probe_seq = estate->probe_seq;
67 s->untried_addrs = (1UL << estate->addresses->nr_addrs) - 1;
68 init_waitqueue_entry(&s->probe_waiter, current);
69 afs_get_address_preferences(op->net, estate->addresses);
70 }
71 rcu_read_unlock();
72
73
74 op->untried_servers = (1UL << op->server_list->nr_servers) - 1;
75 op->server_index = -1;
76
77 cb_server = vnode->cb_server;
78 if (cb_server) {
79 /* See if the vnode's preferred record is still available */
80 for (i = 0; i < op->server_list->nr_servers; i++) {
81 server = op->server_list->servers[i].server;
82 if (server == cb_server) {
83 op->server_index = i;
84 goto found_interest;
85 }
86 }
87
88 /* If we have a lock outstanding on a server that's no longer
89 * serving this vnode, then we can't switch to another server
90 * and have to return an error.
91 */
92 if (op->flags & AFS_OPERATION_CUR_ONLY) {
93 afs_op_set_error(op, -ESTALE);
94 trace_afs_rotate(op, afs_rotate_trace_stale_lock, 0);
95 return false;
96 }
97
98 /* Note that the callback promise is effectively broken */
99 write_seqlock(&vnode->cb_lock);
100 ASSERTCMP(cb_server, ==, vnode->cb_server);
101 vnode->cb_server = NULL;
102 if (atomic64_xchg(&vnode->cb_expires_at, AFS_NO_CB_PROMISE) != AFS_NO_CB_PROMISE)
103 vnode->cb_break++;
104 write_sequnlock(&vnode->cb_lock);
105 }
106
107found_interest:
108 return true;
109}
110
111/*
112 * Post volume busy note.
113 */
114static void afs_busy(struct afs_operation *op, u32 abort_code)
115{
116 const char *m;
117
118 switch (abort_code) {
119 case VOFFLINE: m = "offline"; break;
120 case VRESTARTING: m = "restarting"; break;
121 case VSALVAGING: m = "being salvaged"; break;
122 default: m = "busy"; break;
123 }
124
125 pr_notice("kAFS: Volume %llu '%s' on server %pU is %s\n",
126 op->volume->vid, op->volume->name, &op->server->uuid, m);
127}
128
129/*
130 * Sleep and retry the operation to the same fileserver.
131 */
132static bool afs_sleep_and_retry(struct afs_operation *op)
133{
134 trace_afs_rotate(op, afs_rotate_trace_busy_sleep, 0);
135 if (!(op->flags & AFS_OPERATION_UNINTR)) {
136 msleep_interruptible(1000);
137 if (signal_pending(current)) {
138 afs_op_set_error(op, -ERESTARTSYS);
139 return false;
140 }
141 } else {
142 msleep(1000);
143 }
144
145 return true;
146}
147
148/*
149 * Select the fileserver to use. May be called multiple times to rotate
150 * through the fileservers.
151 */
152bool afs_select_fileserver(struct afs_operation *op)
153{
154 struct afs_addr_list *alist;
155 struct afs_server *server;
156 struct afs_vnode *vnode = op->file[0].vnode;
157 unsigned long set, failed;
158 s32 abort_code = op->call_abort_code;
159 int best_prio = 0;
160 int error = op->call_error, addr_index, i, j;
161
162 op->nr_iterations++;
163
164 _enter("OP=%x+%x,%llx,%u{%lx},%u{%lx},%d,%d",
165 op->debug_id, op->nr_iterations, op->volume->vid,
166 op->server_index, op->untried_servers,
167 op->addr_index, op->addr_tried,
168 error, abort_code);
169
170 if (op->flags & AFS_OPERATION_STOP) {
171 trace_afs_rotate(op, afs_rotate_trace_stopped, 0);
172 _leave(" = f [stopped]");
173 return false;
174 }
175
176 if (op->nr_iterations == 0)
177 goto start;
178
179 WRITE_ONCE(op->estate->addresses->addrs[op->addr_index].last_error, error);
180 trace_afs_rotate(op, afs_rotate_trace_iter, op->call_error);
181
182 /* Evaluate the result of the previous operation, if there was one. */
183 switch (op->call_error) {
184 case 0:
185 clear_bit(AFS_SE_VOLUME_OFFLINE,
186 &op->server_list->servers[op->server_index].flags);
187 clear_bit(AFS_SE_VOLUME_BUSY,
188 &op->server_list->servers[op->server_index].flags);
189 op->cumul_error.responded = true;
190
191 /* We succeeded, but we may need to redo the op from another
192 * server if we're looking at a set of RO volumes where some of
193 * the servers have not yet been brought up to date lest we
194 * regress the data. We only switch to the new version once
195 * >=50% of the servers are updated.
196 */
197 error = afs_update_volume_state(op);
198 if (error != 0) {
199 if (error == 1) {
200 afs_sleep_and_retry(op);
201 goto restart_from_beginning;
202 }
203 afs_op_set_error(op, error);
204 goto failed;
205 }
206 fallthrough;
207 default:
208 /* Success or local failure. Stop. */
209 afs_op_set_error(op, error);
210 op->flags |= AFS_OPERATION_STOP;
211 trace_afs_rotate(op, afs_rotate_trace_stop, error);
212 _leave(" = f [okay/local %d]", error);
213 return false;
214
215 case -ECONNABORTED:
216 /* The far side rejected the operation on some grounds. This
217 * might involve the server being busy or the volume having been moved.
218 *
219 * Note that various V* errors should not be sent to a cache manager
220 * by a fileserver as they should be translated to more modern UAE*
221 * errors instead. IBM AFS and OpenAFS fileservers, however, do leak
222 * these abort codes.
223 */
224 trace_afs_rotate(op, afs_rotate_trace_aborted, abort_code);
225 op->cumul_error.responded = true;
226 switch (abort_code) {
227 case VNOVOL:
228 /* This fileserver doesn't know about the volume.
229 * - May indicate that the VL is wrong - retry once and compare
230 * the results.
231 * - May indicate that the fileserver couldn't attach to the vol.
232 * - The volume might have been temporarily removed so that it can
233 * be replaced by a volume restore. "vos" might have ended one
234 * transaction and has yet to create the next.
235 * - The volume might not be blessed or might not be in-service
236 * (administrative action).
237 */
238 if (op->flags & AFS_OPERATION_VNOVOL) {
239 afs_op_accumulate_error(op, -EREMOTEIO, abort_code);
240 goto next_server;
241 }
242
243 write_lock(&op->volume->servers_lock);
244 op->server_list->vnovol_mask |= 1 << op->server_index;
245 write_unlock(&op->volume->servers_lock);
246
247 set_bit(AFS_VOLUME_NEEDS_UPDATE, &op->volume->flags);
248 error = afs_check_volume_status(op->volume, op);
249 if (error < 0) {
250 afs_op_set_error(op, error);
251 goto failed;
252 }
253
254 if (test_bit(AFS_VOLUME_DELETED, &op->volume->flags)) {
255 afs_op_set_error(op, -ENOMEDIUM);
256 goto failed;
257 }
258
259 /* If the server list didn't change, then assume that
260 * it's the fileserver having trouble.
261 */
262 if (rcu_access_pointer(op->volume->servers) == op->server_list) {
263 afs_op_accumulate_error(op, -EREMOTEIO, abort_code);
264 goto next_server;
265 }
266
267 /* Try again */
268 op->flags |= AFS_OPERATION_VNOVOL;
269 _leave(" = t [vnovol]");
270 return true;
271
272 case VVOLEXISTS:
273 case VONLINE:
274 /* These should not be returned from the fileserver. */
275 pr_warn("Fileserver returned unexpected abort %d\n",
276 abort_code);
277 afs_op_accumulate_error(op, -EREMOTEIO, abort_code);
278 goto next_server;
279
280 case VNOSERVICE:
281 /* Prior to AFS 3.2 VNOSERVICE was returned from the fileserver
282 * if the volume was neither in-service nor administratively
283 * blessed. All usage was replaced by VNOVOL because AFS 3.1 and
284 * earlier cache managers did not handle VNOSERVICE and assumed
285 * it was the client OSes errno 105.
286 *
287 * Starting with OpenAFS 1.4.8 VNOSERVICE was repurposed as the
288 * fileserver idle dead time error which was sent in place of
289 * RX_CALL_TIMEOUT (-3). The error was intended to be sent if the
290 * fileserver took too long to send a reply to the client.
291 * RX_CALL_TIMEOUT would have caused the cache manager to mark the
292 * server down whereas VNOSERVICE since AFS 3.2 would cause cache
293 * manager to temporarily (up to 15 minutes) mark the volume
294 * instance as unusable.
295 *
296 * The idle dead logic resulted in cache inconsistency since a
297 * state changing call that the cache manager assumed was dead
298 * could still be processed to completion by the fileserver. This
299 * logic was removed in OpenAFS 1.8.0 and VNOSERVICE is no longer
300 * returned. However, many 1.4.8 through 1.6.24 fileservers are
301 * still in existence.
302 *
303 * AuriStorFS fileservers have never returned VNOSERVICE.
304 *
305 * VNOSERVICE should be treated as an alias for RX_CALL_TIMEOUT.
306 */
307 case RX_CALL_TIMEOUT:
308 afs_op_accumulate_error(op, -ETIMEDOUT, abort_code);
309 goto next_server;
310
311 case VSALVAGING: /* This error should not be leaked to cache managers
312 * but is from OpenAFS demand attach fileservers.
313 * It should be treated as an alias for VOFFLINE.
314 */
315 case VSALVAGE: /* VSALVAGE should be treated as a synonym of VOFFLINE */
316 case VOFFLINE:
317 /* The volume is in use by the volserver or another volume utility
318 * for an operation that might alter the contents. The volume is
319 * expected to come back but it might take a long time (could be
320 * days).
321 */
322 if (!test_and_set_bit(AFS_SE_VOLUME_OFFLINE,
323 &op->server_list->servers[op->server_index].flags)) {
324 afs_busy(op, abort_code);
325 clear_bit(AFS_SE_VOLUME_BUSY,
326 &op->server_list->servers[op->server_index].flags);
327 }
328 if (op->flags & AFS_OPERATION_NO_VSLEEP) {
329 afs_op_set_error(op, -EADV);
330 goto failed;
331 }
332 goto busy;
333
334 case VRESTARTING: /* The fileserver is either shutting down or starting up. */
335 case VBUSY:
336 /* The volume is in use by the volserver or another volume
337 * utility for an operation that is not expected to alter the
338 * contents of the volume. VBUSY does not need to be returned
339 * for a ROVOL or BACKVOL bound to an ITBusy volserver
340 * transaction. The fileserver is permitted to continue serving
341 * content from ROVOLs and BACKVOLs during an ITBusy transaction
342 * because the content will not change. However, many fileserver
343 * releases do return VBUSY for ROVOL and BACKVOL instances under
344 * many circumstances.
345 *
346 * Retry after going round all the servers unless we have a file
347 * lock we need to maintain.
348 */
349 if (op->flags & AFS_OPERATION_NO_VSLEEP) {
350 afs_op_set_error(op, -EBUSY);
351 goto failed;
352 }
353 if (!test_and_set_bit(AFS_SE_VOLUME_BUSY,
354 &op->server_list->servers[op->server_index].flags)) {
355 afs_busy(op, abort_code);
356 clear_bit(AFS_SE_VOLUME_OFFLINE,
357 &op->server_list->servers[op->server_index].flags);
358 }
359 busy:
360 if (op->flags & AFS_OPERATION_CUR_ONLY) {
361 if (!afs_sleep_and_retry(op))
362 goto failed;
363
364 /* Retry with same server & address */
365 _leave(" = t [vbusy]");
366 return true;
367 }
368
369 op->flags |= AFS_OPERATION_VBUSY;
370 goto next_server;
371
372 case VMOVED:
373 /* The volume migrated to another server. We consider
374 * consider all locks and callbacks broken and request
375 * an update from the VLDB.
376 *
377 * We also limit the number of VMOVED hops we will
378 * honour, just in case someone sets up a loop.
379 */
380 if (op->flags & AFS_OPERATION_VMOVED) {
381 afs_op_set_error(op, -EREMOTEIO);
382 goto failed;
383 }
384 op->flags |= AFS_OPERATION_VMOVED;
385
386 set_bit(AFS_VOLUME_WAIT, &op->volume->flags);
387 set_bit(AFS_VOLUME_NEEDS_UPDATE, &op->volume->flags);
388 error = afs_check_volume_status(op->volume, op);
389 if (error < 0) {
390 afs_op_set_error(op, error);
391 goto failed;
392 }
393
394 /* If the server list didn't change, then the VLDB is
395 * out of sync with the fileservers. This is hopefully
396 * a temporary condition, however, so we don't want to
397 * permanently block access to the file.
398 *
399 * TODO: Try other fileservers if we can.
400 *
401 * TODO: Retry a few times with sleeps.
402 */
403 if (rcu_access_pointer(op->volume->servers) == op->server_list) {
404 afs_op_accumulate_error(op, -ENOMEDIUM, abort_code);
405 goto failed;
406 }
407
408 goto restart_from_beginning;
409
410 case UAEIO:
411 case VIO:
412 afs_op_accumulate_error(op, -EREMOTEIO, abort_code);
413 if (op->volume->type != AFSVL_RWVOL)
414 goto next_server;
415 goto failed;
416
417 case VDISKFULL:
418 case UAENOSPC:
419 /* The partition is full. Only applies to RWVOLs.
420 * Translate locally and return ENOSPC.
421 * No replicas to failover to.
422 */
423 afs_op_set_error(op, -ENOSPC);
424 goto failed_but_online;
425
426 case VOVERQUOTA:
427 case UAEDQUOT:
428 /* Volume is full. Only applies to RWVOLs.
429 * Translate locally and return EDQUOT.
430 * No replicas to failover to.
431 */
432 afs_op_set_error(op, -EDQUOT);
433 goto failed_but_online;
434
435 default:
436 afs_op_accumulate_error(op, error, abort_code);
437 failed_but_online:
438 clear_bit(AFS_SE_VOLUME_OFFLINE,
439 &op->server_list->servers[op->server_index].flags);
440 clear_bit(AFS_SE_VOLUME_BUSY,
441 &op->server_list->servers[op->server_index].flags);
442 goto failed;
443 }
444
445 case -ETIMEDOUT:
446 case -ETIME:
447 if (afs_op_error(op) != -EDESTADDRREQ)
448 goto iterate_address;
449 fallthrough;
450 case -ERFKILL:
451 case -EADDRNOTAVAIL:
452 case -ENETUNREACH:
453 case -EHOSTUNREACH:
454 case -EHOSTDOWN:
455 case -ECONNREFUSED:
456 _debug("no conn");
457 afs_op_accumulate_error(op, error, 0);
458 goto iterate_address;
459
460 case -ENETRESET:
461 pr_warn("kAFS: Peer reset %s (op=%x)\n",
462 op->type ? op->type->name : "???", op->debug_id);
463 fallthrough;
464 case -ECONNRESET:
465 _debug("call reset");
466 afs_op_set_error(op, error);
467 goto failed;
468 }
469
470restart_from_beginning:
471 trace_afs_rotate(op, afs_rotate_trace_restart, 0);
472 _debug("restart");
473 op->estate = NULL;
474 op->server = NULL;
475 afs_clear_server_states(op);
476 op->server_states = NULL;
477 afs_put_serverlist(op->net, op->server_list);
478 op->server_list = NULL;
479start:
480 _debug("start");
481 ASSERTCMP(op->estate, ==, NULL);
482 /* See if we need to do an update of the volume record. Note that the
483 * volume may have moved or even have been deleted.
484 */
485 error = afs_check_volume_status(op->volume, op);
486 trace_afs_rotate(op, afs_rotate_trace_check_vol_status, error);
487 if (error < 0) {
488 afs_op_set_error(op, error);
489 goto failed;
490 }
491
492 if (!afs_start_fs_iteration(op, vnode))
493 goto failed;
494
495 _debug("__ VOL %llx __", op->volume->vid);
496
497pick_server:
498 _debug("pick [%lx]", op->untried_servers);
499 ASSERTCMP(op->estate, ==, NULL);
500
501 error = afs_wait_for_fs_probes(op, op->server_states,
502 !(op->flags & AFS_OPERATION_UNINTR));
503 switch (error) {
504 case 0: /* No untried responsive servers and no outstanding probes */
505 trace_afs_rotate(op, afs_rotate_trace_probe_none, 0);
506 goto no_more_servers;
507 case 1: /* Got a response */
508 trace_afs_rotate(op, afs_rotate_trace_probe_response, 0);
509 break;
510 case 2: /* Probe data superseded */
511 trace_afs_rotate(op, afs_rotate_trace_probe_superseded, 0);
512 goto restart_from_beginning;
513 default:
514 trace_afs_rotate(op, afs_rotate_trace_probe_error, error);
515 afs_op_set_error(op, error);
516 goto failed;
517 }
518
519 /* Pick the untried server with the highest priority untried endpoint.
520 * If we have outstanding callbacks, we stick with the server we're
521 * already using if we can.
522 */
523 if (op->server) {
524 _debug("server %u", op->server_index);
525 if (test_bit(op->server_index, &op->untried_servers))
526 goto selected_server;
527 op->server = NULL;
528 _debug("no server");
529 }
530
531 rcu_read_lock();
532 op->server_index = -1;
533 best_prio = -1;
534 for (i = 0; i < op->server_list->nr_servers; i++) {
535 struct afs_endpoint_state *es;
536 struct afs_server_entry *se = &op->server_list->servers[i];
537 struct afs_addr_list *sal;
538 struct afs_server *s = se->server;
539
540 if (!test_bit(i, &op->untried_servers) ||
541 test_bit(AFS_SE_EXCLUDED, &se->flags) ||
542 !test_bit(AFS_SERVER_FL_RESPONDING, &s->flags))
543 continue;
544 es = op->server_states[i].endpoint_state;
545 sal = es->addresses;
546
547 afs_get_address_preferences_rcu(op->net, sal);
548 for (j = 0; j < sal->nr_addrs; j++) {
549 if (es->failed_set & (1 << j))
550 continue;
551 if (!sal->addrs[j].peer)
552 continue;
553 if (sal->addrs[j].prio > best_prio) {
554 op->server_index = i;
555 best_prio = sal->addrs[j].prio;
556 }
557 }
558 }
559 rcu_read_unlock();
560
561 if (op->server_index == -1)
562 goto no_more_servers;
563
564selected_server:
565 trace_afs_rotate(op, afs_rotate_trace_selected_server, best_prio);
566 _debug("use %d prio %u", op->server_index, best_prio);
567 __clear_bit(op->server_index, &op->untried_servers);
568
569 /* We're starting on a different fileserver from the list. We need to
570 * check it, create a callback intercept, find its address list and
571 * probe its capabilities before we use it.
572 */
573 ASSERTCMP(op->estate, ==, NULL);
574 server = op->server_list->servers[op->server_index].server;
575
576 if (!afs_check_server_record(op, server, op->key))
577 goto failed;
578
579 _debug("USING SERVER: %pU", &server->uuid);
580
581 op->flags |= AFS_OPERATION_RETRY_SERVER;
582 op->server = server;
583 if (vnode->cb_server != server) {
584 vnode->cb_server = server;
585 vnode->cb_v_check = atomic_read(&vnode->volume->cb_v_break);
586 atomic64_set(&vnode->cb_expires_at, AFS_NO_CB_PROMISE);
587 }
588
589retry_server:
590 op->addr_tried = 0;
591 op->addr_index = -1;
592
593iterate_address:
594 /* Iterate over the current server's address list to try and find an
595 * address on which it will respond to us.
596 */
597 op->estate = op->server_states[op->server_index].endpoint_state;
598 set = READ_ONCE(op->estate->responsive_set);
599 failed = READ_ONCE(op->estate->failed_set);
600 _debug("iterate ES=%x rs=%lx fs=%lx", op->estate->probe_seq, set, failed);
601 set &= ~(failed | op->addr_tried);
602 trace_afs_rotate(op, afs_rotate_trace_iterate_addr, set);
603 if (!set)
604 goto wait_for_more_probe_results;
605
606 alist = op->estate->addresses;
607 best_prio = -1;
608 addr_index = 0;
609 for (i = 0; i < alist->nr_addrs; i++) {
610 if (!(set & (1 << i)))
611 continue;
612 if (alist->addrs[i].prio > best_prio) {
613 addr_index = i;
614 best_prio = alist->addrs[i].prio;
615 }
616 }
617
618 alist->preferred = addr_index;
619
620 op->addr_index = addr_index;
621 set_bit(addr_index, &op->addr_tried);
622
623 op->volsync.creation = TIME64_MIN;
624 op->volsync.update = TIME64_MIN;
625 op->call_responded = false;
626 _debug("address [%u] %u/%u %pISp",
627 op->server_index, addr_index, alist->nr_addrs,
628 rxrpc_kernel_remote_addr(alist->addrs[op->addr_index].peer));
629 _leave(" = t");
630 return true;
631
632wait_for_more_probe_results:
633 error = afs_wait_for_one_fs_probe(op->server, op->estate, op->addr_tried,
634 !(op->flags & AFS_OPERATION_UNINTR));
635 if (error == 1)
636 goto iterate_address;
637 if (!error)
638 goto restart_from_beginning;
639
640 /* We've now had a failure to respond on all of a server's addresses -
641 * immediately probe them again and consider retrying the server.
642 */
643 trace_afs_rotate(op, afs_rotate_trace_probe_fileserver, 0);
644 afs_probe_fileserver(op->net, op->server);
645 if (op->flags & AFS_OPERATION_RETRY_SERVER) {
646 error = afs_wait_for_one_fs_probe(op->server, op->estate, op->addr_tried,
647 !(op->flags & AFS_OPERATION_UNINTR));
648 switch (error) {
649 case 1:
650 op->flags &= ~AFS_OPERATION_RETRY_SERVER;
651 trace_afs_rotate(op, afs_rotate_trace_retry_server, 1);
652 goto retry_server;
653 case 0:
654 trace_afs_rotate(op, afs_rotate_trace_retry_server, 0);
655 goto restart_from_beginning;
656 case -ERESTARTSYS:
657 afs_op_set_error(op, error);
658 goto failed;
659 case -ETIME:
660 case -EDESTADDRREQ:
661 goto next_server;
662 }
663 }
664
665next_server:
666 trace_afs_rotate(op, afs_rotate_trace_next_server, 0);
667 _debug("next");
668 op->estate = NULL;
669 goto pick_server;
670
671no_more_servers:
672 /* That's all the servers poked to no good effect. Try again if some
673 * of them were busy.
674 */
675 trace_afs_rotate(op, afs_rotate_trace_no_more_servers, 0);
676 if (op->flags & AFS_OPERATION_VBUSY) {
677 afs_sleep_and_retry(op);
678 op->flags &= ~AFS_OPERATION_VBUSY;
679 goto restart_from_beginning;
680 }
681
682 rcu_read_lock();
683 for (i = 0; i < op->server_list->nr_servers; i++) {
684 struct afs_endpoint_state *estate;
685
686 estate = op->server_states[i].endpoint_state;
687 error = READ_ONCE(estate->error);
688 if (error < 0)
689 afs_op_accumulate_error(op, error, estate->abort_code);
690 }
691 rcu_read_unlock();
692
693failed:
694 trace_afs_rotate(op, afs_rotate_trace_failed, 0);
695 op->flags |= AFS_OPERATION_STOP;
696 op->estate = NULL;
697 _leave(" = f [failed %d]", afs_op_error(op));
698 return false;
699}
700
701/*
702 * Dump cursor state in the case of the error being EDESTADDRREQ.
703 */
704void afs_dump_edestaddrreq(const struct afs_operation *op)
705{
706 static int count;
707 int i;
708
709 if (!IS_ENABLED(CONFIG_AFS_DEBUG_CURSOR) || count > 3)
710 return;
711 count++;
712
713 rcu_read_lock();
714
715 pr_notice("EDESTADDR occurred\n");
716 pr_notice("OP: cbb=%x cbb2=%x fl=%x err=%hd\n",
717 op->file[0].cb_break_before,
718 op->file[1].cb_break_before, op->flags, op->cumul_error.error);
719 pr_notice("OP: ut=%lx ix=%d ni=%u\n",
720 op->untried_servers, op->server_index, op->nr_iterations);
721 pr_notice("OP: call er=%d ac=%d r=%u\n",
722 op->call_error, op->call_abort_code, op->call_responded);
723
724 if (op->server_list) {
725 const struct afs_server_list *sl = op->server_list;
726
727 pr_notice("FC: SL nr=%u vnov=%hx\n",
728 sl->nr_servers, sl->vnovol_mask);
729 for (i = 0; i < sl->nr_servers; i++) {
730 const struct afs_server *s = sl->servers[i].server;
731 const struct afs_endpoint_state *e =
732 rcu_dereference(s->endpoint_state);
733 const struct afs_addr_list *a = e->addresses;
734
735 pr_notice("FC: server fl=%lx av=%u %pU\n",
736 s->flags, s->addr_version, &s->uuid);
737 pr_notice("FC: - pq=%x R=%lx F=%lx\n",
738 e->probe_seq, e->responsive_set, e->failed_set);
739 if (a) {
740 pr_notice("FC: - av=%u nr=%u/%u/%u pr=%u\n",
741 a->version,
742 a->nr_ipv4, a->nr_addrs, a->max_addrs,
743 a->preferred);
744 if (a == e->addresses)
745 pr_notice("FC: - current\n");
746 }
747 }
748 }
749
750 pr_notice("AC: t=%lx ax=%d\n", op->addr_tried, op->addr_index);
751 rcu_read_unlock();
752}
1// SPDX-License-Identifier: GPL-2.0-or-later
2/* Handle fileserver selection and rotation.
3 *
4 * Copyright (C) 2017 Red Hat, Inc. All Rights Reserved.
5 * Written by David Howells (dhowells@redhat.com)
6 */
7
8#include <linux/kernel.h>
9#include <linux/slab.h>
10#include <linux/fs.h>
11#include <linux/sched.h>
12#include <linux/delay.h>
13#include <linux/sched/signal.h>
14#include "internal.h"
15#include "afs_fs.h"
16#include "protocol_uae.h"
17
18void afs_clear_server_states(struct afs_operation *op)
19{
20 unsigned int i;
21
22 if (op->server_states) {
23 for (i = 0; i < op->server_list->nr_servers; i++)
24 afs_put_endpoint_state(op->server_states[i].endpoint_state,
25 afs_estate_trace_put_server_state);
26 kfree(op->server_states);
27 }
28}
29
30/*
31 * Begin iteration through a server list, starting with the vnode's last used
32 * server if possible, or the last recorded good server if not.
33 */
34static bool afs_start_fs_iteration(struct afs_operation *op,
35 struct afs_vnode *vnode)
36{
37 struct afs_server *server;
38 void *cb_server;
39 int i;
40
41 trace_afs_rotate(op, afs_rotate_trace_start, 0);
42
43 read_lock(&op->volume->servers_lock);
44 op->server_list = afs_get_serverlist(
45 rcu_dereference_protected(op->volume->servers,
46 lockdep_is_held(&op->volume->servers_lock)));
47 read_unlock(&op->volume->servers_lock);
48
49 op->server_states = kcalloc(op->server_list->nr_servers, sizeof(op->server_states[0]),
50 GFP_KERNEL);
51 if (!op->server_states) {
52 afs_op_nomem(op);
53 trace_afs_rotate(op, afs_rotate_trace_nomem, 0);
54 return false;
55 }
56
57 rcu_read_lock();
58 for (i = 0; i < op->server_list->nr_servers; i++) {
59 struct afs_endpoint_state *estate;
60 struct afs_server_state *s = &op->server_states[i];
61
62 server = op->server_list->servers[i].server;
63 estate = rcu_dereference(server->endpoint_state);
64 s->endpoint_state = afs_get_endpoint_state(estate,
65 afs_estate_trace_get_server_state);
66 s->probe_seq = estate->probe_seq;
67 s->untried_addrs = (1UL << estate->addresses->nr_addrs) - 1;
68 init_waitqueue_entry(&s->probe_waiter, current);
69 afs_get_address_preferences(op->net, estate->addresses);
70 }
71 rcu_read_unlock();
72
73
74 op->untried_servers = (1UL << op->server_list->nr_servers) - 1;
75 op->server_index = -1;
76
77 cb_server = vnode->cb_server;
78 if (cb_server) {
79 /* See if the vnode's preferred record is still available */
80 for (i = 0; i < op->server_list->nr_servers; i++) {
81 server = op->server_list->servers[i].server;
82 if (server == cb_server) {
83 op->server_index = i;
84 goto found_interest;
85 }
86 }
87
88 /* If we have a lock outstanding on a server that's no longer
89 * serving this vnode, then we can't switch to another server
90 * and have to return an error.
91 */
92 if (op->flags & AFS_OPERATION_CUR_ONLY) {
93 afs_op_set_error(op, -ESTALE);
94 trace_afs_rotate(op, afs_rotate_trace_stale_lock, 0);
95 return false;
96 }
97
98 /* Note that the callback promise is effectively broken */
99 write_seqlock(&vnode->cb_lock);
100 ASSERTCMP(cb_server, ==, vnode->cb_server);
101 vnode->cb_server = NULL;
102 if (atomic64_xchg(&vnode->cb_expires_at, AFS_NO_CB_PROMISE) != AFS_NO_CB_PROMISE)
103 vnode->cb_break++;
104 write_sequnlock(&vnode->cb_lock);
105 }
106
107found_interest:
108 return true;
109}
110
111/*
112 * Post volume busy note.
113 */
114static void afs_busy(struct afs_operation *op, u32 abort_code)
115{
116 const char *m;
117
118 switch (abort_code) {
119 case VOFFLINE: m = "offline"; break;
120 case VRESTARTING: m = "restarting"; break;
121 case VSALVAGING: m = "being salvaged"; break;
122 default: m = "busy"; break;
123 }
124
125 pr_notice("kAFS: Volume %llu '%s' on server %pU is %s\n",
126 op->volume->vid, op->volume->name, &op->server->uuid, m);
127}
128
129/*
130 * Sleep and retry the operation to the same fileserver.
131 */
132static bool afs_sleep_and_retry(struct afs_operation *op)
133{
134 trace_afs_rotate(op, afs_rotate_trace_busy_sleep, 0);
135 if (!(op->flags & AFS_OPERATION_UNINTR)) {
136 msleep_interruptible(1000);
137 if (signal_pending(current)) {
138 afs_op_set_error(op, -ERESTARTSYS);
139 return false;
140 }
141 } else {
142 msleep(1000);
143 }
144
145 return true;
146}
147
148/*
149 * Select the fileserver to use. May be called multiple times to rotate
150 * through the fileservers.
151 */
152bool afs_select_fileserver(struct afs_operation *op)
153{
154 struct afs_addr_list *alist;
155 struct afs_server *server;
156 struct afs_vnode *vnode = op->file[0].vnode;
157 unsigned long set, failed;
158 s32 abort_code = op->call_abort_code;
159 int best_prio = 0;
160 int error = op->call_error, addr_index, i, j;
161
162 op->nr_iterations++;
163
164 _enter("OP=%x+%x,%llx,%u{%lx},%u{%lx},%d,%d",
165 op->debug_id, op->nr_iterations, op->volume->vid,
166 op->server_index, op->untried_servers,
167 op->addr_index, op->addr_tried,
168 error, abort_code);
169
170 if (op->flags & AFS_OPERATION_STOP) {
171 trace_afs_rotate(op, afs_rotate_trace_stopped, 0);
172 _leave(" = f [stopped]");
173 return false;
174 }
175
176 if (op->nr_iterations == 0)
177 goto start;
178
179 WRITE_ONCE(op->estate->addresses->addrs[op->addr_index].last_error, error);
180 trace_afs_rotate(op, afs_rotate_trace_iter, op->call_error);
181
182 /* Evaluate the result of the previous operation, if there was one. */
183 switch (op->call_error) {
184 case 0:
185 clear_bit(AFS_SE_VOLUME_OFFLINE,
186 &op->server_list->servers[op->server_index].flags);
187 clear_bit(AFS_SE_VOLUME_BUSY,
188 &op->server_list->servers[op->server_index].flags);
189 op->cumul_error.responded = true;
190
191 /* We succeeded, but we may need to redo the op from another
192 * server if we're looking at a set of RO volumes where some of
193 * the servers have not yet been brought up to date lest we
194 * regress the data. We only switch to the new version once
195 * >=50% of the servers are updated.
196 */
197 error = afs_update_volume_state(op);
198 if (error != 0) {
199 if (error == 1) {
200 afs_sleep_and_retry(op);
201 goto restart_from_beginning;
202 }
203 afs_op_set_error(op, error);
204 goto failed;
205 }
206 fallthrough;
207 default:
208 /* Success or local failure. Stop. */
209 afs_op_set_error(op, error);
210 op->flags |= AFS_OPERATION_STOP;
211 trace_afs_rotate(op, afs_rotate_trace_stop, error);
212 _leave(" = f [okay/local %d]", error);
213 return false;
214
215 case -ECONNABORTED:
216 /* The far side rejected the operation on some grounds. This
217 * might involve the server being busy or the volume having been moved.
218 *
219 * Note that various V* errors should not be sent to a cache manager
220 * by a fileserver as they should be translated to more modern UAE*
221 * errors instead. IBM AFS and OpenAFS fileservers, however, do leak
222 * these abort codes.
223 */
224 trace_afs_rotate(op, afs_rotate_trace_aborted, abort_code);
225 op->cumul_error.responded = true;
226 switch (abort_code) {
227 case VNOVOL:
228 /* This fileserver doesn't know about the volume.
229 * - May indicate that the VL is wrong - retry once and compare
230 * the results.
231 * - May indicate that the fileserver couldn't attach to the vol.
232 * - The volume might have been temporarily removed so that it can
233 * be replaced by a volume restore. "vos" might have ended one
234 * transaction and has yet to create the next.
235 * - The volume might not be blessed or might not be in-service
236 * (administrative action).
237 */
238 if (op->flags & AFS_OPERATION_VNOVOL) {
239 afs_op_accumulate_error(op, -EREMOTEIO, abort_code);
240 goto next_server;
241 }
242
243 write_lock(&op->volume->servers_lock);
244 op->server_list->vnovol_mask |= 1 << op->server_index;
245 write_unlock(&op->volume->servers_lock);
246
247 set_bit(AFS_VOLUME_NEEDS_UPDATE, &op->volume->flags);
248 error = afs_check_volume_status(op->volume, op);
249 if (error < 0) {
250 afs_op_set_error(op, error);
251 goto failed;
252 }
253
254 if (test_bit(AFS_VOLUME_DELETED, &op->volume->flags)) {
255 afs_op_set_error(op, -ENOMEDIUM);
256 goto failed;
257 }
258
259 /* If the server list didn't change, then assume that
260 * it's the fileserver having trouble.
261 */
262 if (rcu_access_pointer(op->volume->servers) == op->server_list) {
263 afs_op_accumulate_error(op, -EREMOTEIO, abort_code);
264 goto next_server;
265 }
266
267 /* Try again */
268 op->flags |= AFS_OPERATION_VNOVOL;
269 _leave(" = t [vnovol]");
270 return true;
271
272 case VVOLEXISTS:
273 case VONLINE:
274 /* These should not be returned from the fileserver. */
275 pr_warn("Fileserver returned unexpected abort %d\n",
276 abort_code);
277 afs_op_accumulate_error(op, -EREMOTEIO, abort_code);
278 goto next_server;
279
280 case VNOSERVICE:
281 /* Prior to AFS 3.2 VNOSERVICE was returned from the fileserver
282 * if the volume was neither in-service nor administratively
283 * blessed. All usage was replaced by VNOVOL because AFS 3.1 and
284 * earlier cache managers did not handle VNOSERVICE and assumed
285 * it was the client OSes errno 105.
286 *
287 * Starting with OpenAFS 1.4.8 VNOSERVICE was repurposed as the
288 * fileserver idle dead time error which was sent in place of
289 * RX_CALL_TIMEOUT (-3). The error was intended to be sent if the
290 * fileserver took too long to send a reply to the client.
291 * RX_CALL_TIMEOUT would have caused the cache manager to mark the
292 * server down whereas VNOSERVICE since AFS 3.2 would cause cache
293 * manager to temporarily (up to 15 minutes) mark the volume
294 * instance as unusable.
295 *
296 * The idle dead logic resulted in cache inconsistency since a
297 * state changing call that the cache manager assumed was dead
298 * could still be processed to completion by the fileserver. This
299 * logic was removed in OpenAFS 1.8.0 and VNOSERVICE is no longer
300 * returned. However, many 1.4.8 through 1.6.24 fileservers are
301 * still in existence.
302 *
303 * AuriStorFS fileservers have never returned VNOSERVICE.
304 *
305 * VNOSERVICE should be treated as an alias for RX_CALL_TIMEOUT.
306 */
307 case RX_CALL_TIMEOUT:
308 afs_op_accumulate_error(op, -ETIMEDOUT, abort_code);
309 goto next_server;
310
311 case VSALVAGING: /* This error should not be leaked to cache managers
312 * but is from OpenAFS demand attach fileservers.
313 * It should be treated as an alias for VOFFLINE.
314 */
315 case VSALVAGE: /* VSALVAGE should be treated as a synonym of VOFFLINE */
316 case VOFFLINE:
317 /* The volume is in use by the volserver or another volume utility
318 * for an operation that might alter the contents. The volume is
319 * expected to come back but it might take a long time (could be
320 * days).
321 */
322 if (!test_and_set_bit(AFS_SE_VOLUME_OFFLINE,
323 &op->server_list->servers[op->server_index].flags)) {
324 afs_busy(op, abort_code);
325 clear_bit(AFS_SE_VOLUME_BUSY,
326 &op->server_list->servers[op->server_index].flags);
327 }
328 if (op->flags & AFS_OPERATION_NO_VSLEEP) {
329 afs_op_set_error(op, -EADV);
330 goto failed;
331 }
332 goto busy;
333
334 case VRESTARTING: /* The fileserver is either shutting down or starting up. */
335 case VBUSY:
336 /* The volume is in use by the volserver or another volume
337 * utility for an operation that is not expected to alter the
338 * contents of the volume. VBUSY does not need to be returned
339 * for a ROVOL or BACKVOL bound to an ITBusy volserver
340 * transaction. The fileserver is permitted to continue serving
341 * content from ROVOLs and BACKVOLs during an ITBusy transaction
342 * because the content will not change. However, many fileserver
343 * releases do return VBUSY for ROVOL and BACKVOL instances under
344 * many circumstances.
345 *
346 * Retry after going round all the servers unless we have a file
347 * lock we need to maintain.
348 */
349 if (op->flags & AFS_OPERATION_NO_VSLEEP) {
350 afs_op_set_error(op, -EBUSY);
351 goto failed;
352 }
353 if (!test_and_set_bit(AFS_SE_VOLUME_BUSY,
354 &op->server_list->servers[op->server_index].flags)) {
355 afs_busy(op, abort_code);
356 clear_bit(AFS_SE_VOLUME_OFFLINE,
357 &op->server_list->servers[op->server_index].flags);
358 }
359 busy:
360 if (op->flags & AFS_OPERATION_CUR_ONLY) {
361 if (!afs_sleep_and_retry(op))
362 goto failed;
363
364 /* Retry with same server & address */
365 _leave(" = t [vbusy]");
366 return true;
367 }
368
369 op->flags |= AFS_OPERATION_VBUSY;
370 goto next_server;
371
372 case VMOVED:
373 /* The volume migrated to another server. We consider
374 * consider all locks and callbacks broken and request
375 * an update from the VLDB.
376 *
377 * We also limit the number of VMOVED hops we will
378 * honour, just in case someone sets up a loop.
379 */
380 if (op->flags & AFS_OPERATION_VMOVED) {
381 afs_op_set_error(op, -EREMOTEIO);
382 goto failed;
383 }
384 op->flags |= AFS_OPERATION_VMOVED;
385
386 set_bit(AFS_VOLUME_WAIT, &op->volume->flags);
387 set_bit(AFS_VOLUME_NEEDS_UPDATE, &op->volume->flags);
388 error = afs_check_volume_status(op->volume, op);
389 if (error < 0) {
390 afs_op_set_error(op, error);
391 goto failed;
392 }
393
394 /* If the server list didn't change, then the VLDB is
395 * out of sync with the fileservers. This is hopefully
396 * a temporary condition, however, so we don't want to
397 * permanently block access to the file.
398 *
399 * TODO: Try other fileservers if we can.
400 *
401 * TODO: Retry a few times with sleeps.
402 */
403 if (rcu_access_pointer(op->volume->servers) == op->server_list) {
404 afs_op_accumulate_error(op, -ENOMEDIUM, abort_code);
405 goto failed;
406 }
407
408 goto restart_from_beginning;
409
410 case UAEIO:
411 case VIO:
412 afs_op_accumulate_error(op, -EREMOTEIO, abort_code);
413 if (op->volume->type != AFSVL_RWVOL)
414 goto next_server;
415 goto failed;
416
417 case VDISKFULL:
418 case UAENOSPC:
419 /* The partition is full. Only applies to RWVOLs.
420 * Translate locally and return ENOSPC.
421 * No replicas to failover to.
422 */
423 afs_op_set_error(op, -ENOSPC);
424 goto failed_but_online;
425
426 case VOVERQUOTA:
427 case UAEDQUOT:
428 /* Volume is full. Only applies to RWVOLs.
429 * Translate locally and return EDQUOT.
430 * No replicas to failover to.
431 */
432 afs_op_set_error(op, -EDQUOT);
433 goto failed_but_online;
434
435 default:
436 afs_op_accumulate_error(op, error, abort_code);
437 failed_but_online:
438 clear_bit(AFS_SE_VOLUME_OFFLINE,
439 &op->server_list->servers[op->server_index].flags);
440 clear_bit(AFS_SE_VOLUME_BUSY,
441 &op->server_list->servers[op->server_index].flags);
442 goto failed;
443 }
444
445 case -ETIMEDOUT:
446 case -ETIME:
447 if (afs_op_error(op) != -EDESTADDRREQ)
448 goto iterate_address;
449 fallthrough;
450 case -ERFKILL:
451 case -EADDRNOTAVAIL:
452 case -ENETUNREACH:
453 case -EHOSTUNREACH:
454 case -EHOSTDOWN:
455 case -ECONNREFUSED:
456 _debug("no conn");
457 afs_op_accumulate_error(op, error, 0);
458 goto iterate_address;
459
460 case -ENETRESET:
461 pr_warn("kAFS: Peer reset %s (op=%x)\n",
462 op->type ? op->type->name : "???", op->debug_id);
463 fallthrough;
464 case -ECONNRESET:
465 _debug("call reset");
466 afs_op_set_error(op, error);
467 goto failed;
468 }
469
470restart_from_beginning:
471 trace_afs_rotate(op, afs_rotate_trace_restart, 0);
472 _debug("restart");
473 op->estate = NULL;
474 op->server = NULL;
475 afs_clear_server_states(op);
476 op->server_states = NULL;
477 afs_put_serverlist(op->net, op->server_list);
478 op->server_list = NULL;
479start:
480 _debug("start");
481 ASSERTCMP(op->estate, ==, NULL);
482 /* See if we need to do an update of the volume record. Note that the
483 * volume may have moved or even have been deleted.
484 */
485 error = afs_check_volume_status(op->volume, op);
486 trace_afs_rotate(op, afs_rotate_trace_check_vol_status, error);
487 if (error < 0) {
488 afs_op_set_error(op, error);
489 goto failed;
490 }
491
492 if (!afs_start_fs_iteration(op, vnode))
493 goto failed;
494
495 _debug("__ VOL %llx __", op->volume->vid);
496
497pick_server:
498 _debug("pick [%lx]", op->untried_servers);
499 ASSERTCMP(op->estate, ==, NULL);
500
501 error = afs_wait_for_fs_probes(op, op->server_states,
502 !(op->flags & AFS_OPERATION_UNINTR));
503 switch (error) {
504 case 0: /* No untried responsive servers and no outstanding probes */
505 trace_afs_rotate(op, afs_rotate_trace_probe_none, 0);
506 goto no_more_servers;
507 case 1: /* Got a response */
508 trace_afs_rotate(op, afs_rotate_trace_probe_response, 0);
509 break;
510 case 2: /* Probe data superseded */
511 trace_afs_rotate(op, afs_rotate_trace_probe_superseded, 0);
512 goto restart_from_beginning;
513 default:
514 trace_afs_rotate(op, afs_rotate_trace_probe_error, error);
515 afs_op_set_error(op, error);
516 goto failed;
517 }
518
519 /* Pick the untried server with the highest priority untried endpoint.
520 * If we have outstanding callbacks, we stick with the server we're
521 * already using if we can.
522 */
523 if (op->server) {
524 _debug("server %u", op->server_index);
525 if (test_bit(op->server_index, &op->untried_servers))
526 goto selected_server;
527 op->server = NULL;
528 _debug("no server");
529 }
530
531 rcu_read_lock();
532 op->server_index = -1;
533 best_prio = -1;
534 for (i = 0; i < op->server_list->nr_servers; i++) {
535 struct afs_endpoint_state *es;
536 struct afs_server_entry *se = &op->server_list->servers[i];
537 struct afs_addr_list *sal;
538 struct afs_server *s = se->server;
539
540 if (!test_bit(i, &op->untried_servers) ||
541 test_bit(AFS_SE_EXCLUDED, &se->flags) ||
542 !test_bit(AFS_SERVER_FL_RESPONDING, &s->flags))
543 continue;
544 es = op->server_states->endpoint_state;
545 sal = es->addresses;
546
547 afs_get_address_preferences_rcu(op->net, sal);
548 for (j = 0; j < sal->nr_addrs; j++) {
549 if (!sal->addrs[j].peer)
550 continue;
551 if (sal->addrs[j].prio > best_prio) {
552 op->server_index = i;
553 best_prio = sal->addrs[j].prio;
554 }
555 }
556 }
557 rcu_read_unlock();
558
559 if (op->server_index == -1)
560 goto no_more_servers;
561
562selected_server:
563 trace_afs_rotate(op, afs_rotate_trace_selected_server, best_prio);
564 _debug("use %d prio %u", op->server_index, best_prio);
565 __clear_bit(op->server_index, &op->untried_servers);
566
567 /* We're starting on a different fileserver from the list. We need to
568 * check it, create a callback intercept, find its address list and
569 * probe its capabilities before we use it.
570 */
571 ASSERTCMP(op->estate, ==, NULL);
572 server = op->server_list->servers[op->server_index].server;
573
574 if (!afs_check_server_record(op, server, op->key))
575 goto failed;
576
577 _debug("USING SERVER: %pU", &server->uuid);
578
579 op->flags |= AFS_OPERATION_RETRY_SERVER;
580 op->server = server;
581 if (vnode->cb_server != server) {
582 vnode->cb_server = server;
583 vnode->cb_v_check = atomic_read(&vnode->volume->cb_v_break);
584 atomic64_set(&vnode->cb_expires_at, AFS_NO_CB_PROMISE);
585 }
586
587retry_server:
588 op->addr_tried = 0;
589 op->addr_index = -1;
590
591iterate_address:
592 /* Iterate over the current server's address list to try and find an
593 * address on which it will respond to us.
594 */
595 op->estate = op->server_states[op->server_index].endpoint_state;
596 set = READ_ONCE(op->estate->responsive_set);
597 failed = READ_ONCE(op->estate->failed_set);
598 _debug("iterate ES=%x rs=%lx fs=%lx", op->estate->probe_seq, set, failed);
599 set &= ~(failed | op->addr_tried);
600 trace_afs_rotate(op, afs_rotate_trace_iterate_addr, set);
601 if (!set)
602 goto wait_for_more_probe_results;
603
604 alist = op->estate->addresses;
605 best_prio = -1;
606 addr_index = 0;
607 for (i = 0; i < alist->nr_addrs; i++) {
608 if (alist->addrs[i].prio > best_prio) {
609 addr_index = i;
610 best_prio = alist->addrs[i].prio;
611 }
612 }
613
614 alist->preferred = addr_index;
615
616 op->addr_index = addr_index;
617 set_bit(addr_index, &op->addr_tried);
618
619 op->volsync.creation = TIME64_MIN;
620 op->volsync.update = TIME64_MIN;
621 op->call_responded = false;
622 _debug("address [%u] %u/%u %pISp",
623 op->server_index, addr_index, alist->nr_addrs,
624 rxrpc_kernel_remote_addr(alist->addrs[op->addr_index].peer));
625 _leave(" = t");
626 return true;
627
628wait_for_more_probe_results:
629 error = afs_wait_for_one_fs_probe(op->server, op->estate, op->addr_tried,
630 !(op->flags & AFS_OPERATION_UNINTR));
631 if (!error)
632 goto iterate_address;
633
634 /* We've now had a failure to respond on all of a server's addresses -
635 * immediately probe them again and consider retrying the server.
636 */
637 trace_afs_rotate(op, afs_rotate_trace_probe_fileserver, 0);
638 afs_probe_fileserver(op->net, op->server);
639 if (op->flags & AFS_OPERATION_RETRY_SERVER) {
640 error = afs_wait_for_one_fs_probe(op->server, op->estate, op->addr_tried,
641 !(op->flags & AFS_OPERATION_UNINTR));
642 switch (error) {
643 case 0:
644 op->flags &= ~AFS_OPERATION_RETRY_SERVER;
645 trace_afs_rotate(op, afs_rotate_trace_retry_server, 0);
646 goto retry_server;
647 case -ERESTARTSYS:
648 afs_op_set_error(op, error);
649 goto failed;
650 case -ETIME:
651 case -EDESTADDRREQ:
652 goto next_server;
653 }
654 }
655
656next_server:
657 trace_afs_rotate(op, afs_rotate_trace_next_server, 0);
658 _debug("next");
659 op->estate = NULL;
660 goto pick_server;
661
662no_more_servers:
663 /* That's all the servers poked to no good effect. Try again if some
664 * of them were busy.
665 */
666 trace_afs_rotate(op, afs_rotate_trace_no_more_servers, 0);
667 if (op->flags & AFS_OPERATION_VBUSY) {
668 afs_sleep_and_retry(op);
669 op->flags &= ~AFS_OPERATION_VBUSY;
670 goto restart_from_beginning;
671 }
672
673 rcu_read_lock();
674 for (i = 0; i < op->server_list->nr_servers; i++) {
675 struct afs_endpoint_state *estate;
676
677 estate = op->server_states->endpoint_state;
678 error = READ_ONCE(estate->error);
679 if (error < 0)
680 afs_op_accumulate_error(op, error, estate->abort_code);
681 }
682 rcu_read_unlock();
683
684failed:
685 trace_afs_rotate(op, afs_rotate_trace_failed, 0);
686 op->flags |= AFS_OPERATION_STOP;
687 op->estate = NULL;
688 _leave(" = f [failed %d]", afs_op_error(op));
689 return false;
690}
691
692/*
693 * Dump cursor state in the case of the error being EDESTADDRREQ.
694 */
695void afs_dump_edestaddrreq(const struct afs_operation *op)
696{
697 static int count;
698 int i;
699
700 if (!IS_ENABLED(CONFIG_AFS_DEBUG_CURSOR) || count > 3)
701 return;
702 count++;
703
704 rcu_read_lock();
705
706 pr_notice("EDESTADDR occurred\n");
707 pr_notice("OP: cbb=%x cbb2=%x fl=%x err=%hd\n",
708 op->file[0].cb_break_before,
709 op->file[1].cb_break_before, op->flags, op->cumul_error.error);
710 pr_notice("OP: ut=%lx ix=%d ni=%u\n",
711 op->untried_servers, op->server_index, op->nr_iterations);
712 pr_notice("OP: call er=%d ac=%d r=%u\n",
713 op->call_error, op->call_abort_code, op->call_responded);
714
715 if (op->server_list) {
716 const struct afs_server_list *sl = op->server_list;
717
718 pr_notice("FC: SL nr=%u vnov=%hx\n",
719 sl->nr_servers, sl->vnovol_mask);
720 for (i = 0; i < sl->nr_servers; i++) {
721 const struct afs_server *s = sl->servers[i].server;
722 const struct afs_endpoint_state *e =
723 rcu_dereference(s->endpoint_state);
724 const struct afs_addr_list *a = e->addresses;
725
726 pr_notice("FC: server fl=%lx av=%u %pU\n",
727 s->flags, s->addr_version, &s->uuid);
728 pr_notice("FC: - pq=%x R=%lx F=%lx\n",
729 e->probe_seq, e->responsive_set, e->failed_set);
730 if (a) {
731 pr_notice("FC: - av=%u nr=%u/%u/%u pr=%u\n",
732 a->version,
733 a->nr_ipv4, a->nr_addrs, a->max_addrs,
734 a->preferred);
735 if (a == e->addresses)
736 pr_notice("FC: - current\n");
737 }
738 }
739 }
740
741 pr_notice("AC: t=%lx ax=%d\n", op->addr_tried, op->addr_index);
742 rcu_read_unlock();
743}