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(estate: op->server_states[i].endpoint_state,
25 where: afs_estate_trace_put_server_state);
26 kfree(objp: 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, reason: afs_rotate_trace_start, extra: 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, reason: afs_rotate_trace_nomem, extra: 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 where: 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(wq_entry: &s->probe_waiter, current);
69 afs_get_address_preferences(net: op->net, alist: 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, error: -ESTALE);
94 trace_afs_rotate(op, reason: afs_rotate_trace_stale_lock, extra: 0);
95 return false;
96 }
97
98 /* Note that the callback promise is effectively broken */
99 write_seqlock(sl: &vnode->cb_lock);
100 ASSERTCMP(cb_server, ==, vnode->cb_server);
101 vnode->cb_server = NULL;
102 if (afs_clear_cb_promise(vnode, trace: afs_cb_promise_clear_rotate_server))
103 vnode->cb_break++;
104 write_sequnlock(sl: &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, reason: afs_rotate_trace_busy_sleep, extra: 0);
135 if (!(op->flags & AFS_OPERATION_UNINTR)) {
136 msleep_interruptible(msecs: 1000);
137 if (signal_pending(current)) {
138 afs_op_set_error(op, error: -ERESTARTSYS);
139 return false;
140 }
141 } else {
142 msleep(msecs: 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, reason: afs_rotate_trace_stopped, extra: 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, reason: afs_rotate_trace_iter, extra: 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 addr: &op->server_list->servers[op->server_index].flags);
187 clear_bit(AFS_SE_VOLUME_BUSY,
188 addr: &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, reason: afs_rotate_trace_stop, extra: 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, reason: afs_rotate_trace_aborted, extra: 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, error: -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, addr: &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, error: -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, error: -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, error: -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, error: -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 addr: &op->server_list->servers[op->server_index].flags)) {
324 afs_busy(op, abort_code);
325 clear_bit(AFS_SE_VOLUME_BUSY,
326 addr: &op->server_list->servers[op->server_index].flags);
327 }
328 if (op->flags & AFS_OPERATION_NO_VSLEEP) {
329 afs_op_set_error(op, error: -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, error: -EBUSY);
351 goto failed;
352 }
353 if (!test_and_set_bit(AFS_SE_VOLUME_BUSY,
354 addr: &op->server_list->servers[op->server_index].flags)) {
355 afs_busy(op, abort_code);
356 clear_bit(AFS_SE_VOLUME_OFFLINE,
357 addr: &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, error: -EREMOTEIO);
382 goto failed;
383 }
384 op->flags |= AFS_OPERATION_VMOVED;
385
386 set_bit(AFS_VOLUME_WAIT, addr: &op->volume->flags);
387 set_bit(AFS_VOLUME_NEEDS_UPDATE, addr: &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, error: -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, error: -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, error: -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, error: -EDQUOT);
433 goto failed_but_online;
434
435 case RX_INVALID_OPERATION:
436 case RXGEN_OPCODE:
437 /* Handle downgrading to an older operation. */
438 afs_op_set_error(op, error: -ENOTSUPP);
439 if (op->flags & AFS_OPERATION_DOWNGRADE) {
440 op->flags &= ~AFS_OPERATION_DOWNGRADE;
441 goto go_again;
442 }
443 goto failed_but_online;
444
445 default:
446 afs_op_accumulate_error(op, error, abort_code);
447 failed_but_online:
448 clear_bit(AFS_SE_VOLUME_OFFLINE,
449 addr: &op->server_list->servers[op->server_index].flags);
450 clear_bit(AFS_SE_VOLUME_BUSY,
451 addr: &op->server_list->servers[op->server_index].flags);
452 goto failed;
453 }
454
455 case -ETIMEDOUT:
456 case -ETIME:
457 if (afs_op_error(op) != -EDESTADDRREQ)
458 goto iterate_address;
459 fallthrough;
460 case -ERFKILL:
461 case -EADDRNOTAVAIL:
462 case -ENETUNREACH:
463 case -EHOSTUNREACH:
464 case -EHOSTDOWN:
465 case -ECONNREFUSED:
466 _debug("no conn");
467 afs_op_accumulate_error(op, error, abort_code: 0);
468 goto iterate_address;
469
470 case -ENETRESET:
471 pr_warn("kAFS: Peer reset %s (op=%x)\n",
472 op->type ? op->type->name : "???", op->debug_id);
473 fallthrough;
474 case -ECONNRESET:
475 _debug("call reset");
476 afs_op_set_error(op, error);
477 goto failed;
478 }
479
480restart_from_beginning:
481 trace_afs_rotate(op, reason: afs_rotate_trace_restart, extra: 0);
482 _debug("restart");
483 op->estate = NULL;
484 op->server = NULL;
485 afs_clear_server_states(op);
486 op->server_states = NULL;
487 afs_put_serverlist(op->net, op->server_list);
488 op->server_list = NULL;
489start:
490 _debug("start");
491 ASSERTCMP(op->estate, ==, NULL);
492 /* See if we need to do an update of the volume record. Note that the
493 * volume may have moved or even have been deleted.
494 */
495 error = afs_check_volume_status(op->volume, op);
496 trace_afs_rotate(op, reason: afs_rotate_trace_check_vol_status, extra: error);
497 if (error < 0) {
498 afs_op_set_error(op, error);
499 goto failed;
500 }
501
502 if (!afs_start_fs_iteration(op, vnode))
503 goto failed;
504
505 _debug("__ VOL %llx __", op->volume->vid);
506
507pick_server:
508 _debug("pick [%lx]", op->untried_servers);
509 ASSERTCMP(op->estate, ==, NULL);
510
511 error = afs_wait_for_fs_probes(op, states: op->server_states,
512 intr: !(op->flags & AFS_OPERATION_UNINTR));
513 switch (error) {
514 case 0: /* No untried responsive servers and no outstanding probes */
515 trace_afs_rotate(op, reason: afs_rotate_trace_probe_none, extra: 0);
516 goto no_more_servers;
517 case 1: /* Got a response */
518 trace_afs_rotate(op, reason: afs_rotate_trace_probe_response, extra: 0);
519 break;
520 case 2: /* Probe data superseded */
521 trace_afs_rotate(op, reason: afs_rotate_trace_probe_superseded, extra: 0);
522 goto restart_from_beginning;
523 default:
524 trace_afs_rotate(op, reason: afs_rotate_trace_probe_error, extra: error);
525 afs_op_set_error(op, error);
526 goto failed;
527 }
528
529 /* Pick the untried server with the highest priority untried endpoint.
530 * If we have outstanding callbacks, we stick with the server we're
531 * already using if we can.
532 */
533 if (op->server) {
534 _debug("server %u", op->server_index);
535 if (test_bit(op->server_index, &op->untried_servers))
536 goto selected_server;
537 op->server = NULL;
538 _debug("no server");
539 }
540
541 rcu_read_lock();
542 op->server_index = -1;
543 best_prio = -1;
544 for (i = 0; i < op->server_list->nr_servers; i++) {
545 struct afs_endpoint_state *es;
546 struct afs_server_entry *se = &op->server_list->servers[i];
547 struct afs_addr_list *sal;
548 struct afs_server *s = se->server;
549
550 if (!test_bit(i, &op->untried_servers) ||
551 test_bit(AFS_SE_EXCLUDED, &se->flags) ||
552 !test_bit(AFS_SERVER_FL_RESPONDING, &s->flags))
553 continue;
554 es = op->server_states[i].endpoint_state;
555 sal = es->addresses;
556
557 afs_get_address_preferences_rcu(net: op->net, alist: sal);
558 for (j = 0; j < sal->nr_addrs; j++) {
559 if (es->failed_set & (1 << j))
560 continue;
561 if (!sal->addrs[j].peer)
562 continue;
563 if (sal->addrs[j].prio > best_prio) {
564 op->server_index = i;
565 best_prio = sal->addrs[j].prio;
566 }
567 }
568 }
569 rcu_read_unlock();
570
571 if (op->server_index == -1)
572 goto no_more_servers;
573
574selected_server:
575 trace_afs_rotate(op, reason: afs_rotate_trace_selected_server, extra: best_prio);
576 _debug("use %d prio %u", op->server_index, best_prio);
577 __clear_bit(op->server_index, &op->untried_servers);
578
579 /* We're starting on a different fileserver from the list. We need to
580 * check it, create a callback intercept, find its address list and
581 * probe its capabilities before we use it.
582 */
583 ASSERTCMP(op->estate, ==, NULL);
584 server = op->server_list->servers[op->server_index].server;
585
586 if (!afs_check_server_record(op, server, key: op->key))
587 goto failed;
588
589 _debug("USING SERVER: %pU", &server->uuid);
590
591 op->flags |= AFS_OPERATION_RETRY_SERVER;
592 op->server = server;
593 if (vnode->cb_server != server) {
594 vnode->cb_server = server;
595 vnode->cb_v_check = atomic_read(v: &vnode->volume->cb_v_break);
596 afs_clear_cb_promise(vnode, trace: afs_cb_promise_clear_server_change);
597 }
598
599retry_server:
600 op->addr_tried = 0;
601 op->addr_index = -1;
602
603iterate_address:
604 /* Iterate over the current server's address list to try and find an
605 * address on which it will respond to us.
606 */
607 op->estate = op->server_states[op->server_index].endpoint_state;
608 set = READ_ONCE(op->estate->responsive_set);
609 failed = READ_ONCE(op->estate->failed_set);
610 _debug("iterate ES=%x rs=%lx fs=%lx", op->estate->probe_seq, set, failed);
611 set &= ~(failed | op->addr_tried);
612 trace_afs_rotate(op, reason: afs_rotate_trace_iterate_addr, extra: set);
613 if (!set)
614 goto wait_for_more_probe_results;
615
616 alist = op->estate->addresses;
617 best_prio = -1;
618 addr_index = 0;
619 for (i = 0; i < alist->nr_addrs; i++) {
620 if (!(set & (1 << i)))
621 continue;
622 if (alist->addrs[i].prio > best_prio) {
623 addr_index = i;
624 best_prio = alist->addrs[i].prio;
625 }
626 }
627
628 alist->preferred = addr_index;
629
630 op->addr_index = addr_index;
631 set_bit(nr: addr_index, addr: &op->addr_tried);
632
633 _debug("address [%u] %u/%u %pISp",
634 op->server_index, addr_index, alist->nr_addrs,
635 rxrpc_kernel_remote_addr(alist->addrs[op->addr_index].peer));
636go_again:
637 op->volsync.creation = TIME64_MIN;
638 op->volsync.update = TIME64_MIN;
639 op->call_responded = false;
640 _leave(" = t");
641 return true;
642
643wait_for_more_probe_results:
644 error = afs_wait_for_one_fs_probe(server: op->server, estate: op->estate, exclude: op->addr_tried,
645 is_intr: !(op->flags & AFS_OPERATION_UNINTR));
646 if (error == 1)
647 goto iterate_address;
648 if (!error)
649 goto restart_from_beginning;
650
651 /* We've now had a failure to respond on all of a server's addresses -
652 * immediately probe them again and consider retrying the server.
653 */
654 trace_afs_rotate(op, reason: afs_rotate_trace_probe_fileserver, extra: 0);
655 afs_probe_fileserver(op->net, op->server);
656 if (op->flags & AFS_OPERATION_RETRY_SERVER) {
657 error = afs_wait_for_one_fs_probe(server: op->server, estate: op->estate, exclude: op->addr_tried,
658 is_intr: !(op->flags & AFS_OPERATION_UNINTR));
659 switch (error) {
660 case 1:
661 op->flags &= ~AFS_OPERATION_RETRY_SERVER;
662 trace_afs_rotate(op, reason: afs_rotate_trace_retry_server, extra: 1);
663 goto retry_server;
664 case 0:
665 trace_afs_rotate(op, reason: afs_rotate_trace_retry_server, extra: 0);
666 goto restart_from_beginning;
667 case -ERESTARTSYS:
668 afs_op_set_error(op, error);
669 goto failed;
670 case -ETIME:
671 case -EDESTADDRREQ:
672 goto next_server;
673 }
674 }
675
676next_server:
677 trace_afs_rotate(op, reason: afs_rotate_trace_next_server, extra: 0);
678 _debug("next");
679 op->estate = NULL;
680 goto pick_server;
681
682no_more_servers:
683 /* That's all the servers poked to no good effect. Try again if some
684 * of them were busy.
685 */
686 trace_afs_rotate(op, reason: afs_rotate_trace_no_more_servers, extra: 0);
687 if (op->flags & AFS_OPERATION_VBUSY) {
688 afs_sleep_and_retry(op);
689 op->flags &= ~AFS_OPERATION_VBUSY;
690 goto restart_from_beginning;
691 }
692
693 rcu_read_lock();
694 for (i = 0; i < op->server_list->nr_servers; i++) {
695 struct afs_endpoint_state *estate;
696
697 estate = op->server_states[i].endpoint_state;
698 error = READ_ONCE(estate->error);
699 if (error < 0)
700 afs_op_accumulate_error(op, error, abort_code: estate->abort_code);
701 }
702 rcu_read_unlock();
703
704failed:
705 trace_afs_rotate(op, reason: afs_rotate_trace_failed, extra: 0);
706 op->flags |= AFS_OPERATION_STOP;
707 op->estate = NULL;
708 _leave(" = f [failed %d]", afs_op_error(op));
709 return false;
710}
711
712/*
713 * Dump cursor state in the case of the error being EDESTADDRREQ.
714 */
715void afs_dump_edestaddrreq(const struct afs_operation *op)
716{
717 static int count;
718 int i;
719
720 if (!IS_ENABLED(CONFIG_AFS_DEBUG_CURSOR) || count > 3)
721 return;
722 count++;
723
724 rcu_read_lock();
725
726 pr_notice("EDESTADDR occurred\n");
727 pr_notice("OP: cbb=%x cbb2=%x fl=%x err=%hd\n",
728 op->file[0].cb_break_before,
729 op->file[1].cb_break_before, op->flags, op->cumul_error.error);
730 pr_notice("OP: ut=%lx ix=%d ni=%u\n",
731 op->untried_servers, op->server_index, op->nr_iterations);
732 pr_notice("OP: call er=%d ac=%d r=%u\n",
733 op->call_error, op->call_abort_code, op->call_responded);
734
735 if (op->server_list) {
736 const struct afs_server_list *sl = op->server_list;
737
738 pr_notice("FC: SL nr=%u vnov=%hx\n",
739 sl->nr_servers, sl->vnovol_mask);
740 for (i = 0; i < sl->nr_servers; i++) {
741 const struct afs_server *s = sl->servers[i].server;
742 const struct afs_endpoint_state *e =
743 rcu_dereference(s->endpoint_state);
744 const struct afs_addr_list *a = e->addresses;
745
746 pr_notice("FC: server fl=%lx av=%u %pU\n",
747 s->flags, s->addr_version, &s->uuid);
748 pr_notice("FC: - pq=%x R=%lx F=%lx\n",
749 e->probe_seq, e->responsive_set, e->failed_set);
750 if (a) {
751 pr_notice("FC: - av=%u nr=%u/%u/%u pr=%u\n",
752 a->version,
753 a->nr_ipv4, a->nr_addrs, a->max_addrs,
754 a->preferred);
755 if (a == e->addresses)
756 pr_notice("FC: - current\n");
757 }
758 }
759 }
760
761 pr_notice("AC: t=%lx ax=%d\n", op->addr_tried, op->addr_index);
762 rcu_read_unlock();
763}
764

source code of linux/fs/afs/rotate.c