~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/fs/afs/rotate.c

Version: ~ [ linux-6.11.5 ] ~ [ linux-6.10.14 ] ~ [ linux-6.9.12 ] ~ [ linux-6.8.12 ] ~ [ linux-6.7.12 ] ~ [ linux-6.6.58 ] ~ [ linux-6.5.13 ] ~ [ linux-6.4.16 ] ~ [ linux-6.3.13 ] ~ [ linux-6.2.16 ] ~ [ linux-6.1.114 ] ~ [ linux-6.0.19 ] ~ [ linux-5.19.17 ] ~ [ linux-5.18.19 ] ~ [ linux-5.17.15 ] ~ [ linux-5.16.20 ] ~ [ linux-5.15.169 ] ~ [ linux-5.14.21 ] ~ [ linux-5.13.19 ] ~ [ linux-5.12.19 ] ~ [ linux-5.11.22 ] ~ [ linux-5.10.228 ] ~ [ linux-5.9.16 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.284 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.322 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.336 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.337 ] ~ [ linux-4.4.302 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.9 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  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 
 18 void 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  */
 34 static 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 
107 found_interest:
108         return true;
109 }
110 
111 /*
112  * Post volume busy note.
113  */
114 static 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  */
132 static 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  */
152 bool 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 
470 restart_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;
479 start:
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 
497 pick_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 
564 selected_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 
589 retry_server:
590         op->addr_tried = 0;
591         op->addr_index = -1;
592 
593 iterate_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 
632 wait_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)
636                 goto iterate_address;
637 
638         /* We've now had a failure to respond on all of a server's addresses -
639          * immediately probe them again and consider retrying the server.
640          */
641         trace_afs_rotate(op, afs_rotate_trace_probe_fileserver, 0);
642         afs_probe_fileserver(op->net, op->server);
643         if (op->flags & AFS_OPERATION_RETRY_SERVER) {
644                 error = afs_wait_for_one_fs_probe(op->server, op->estate, op->addr_tried,
645                                                   !(op->flags & AFS_OPERATION_UNINTR));
646                 switch (error) {
647                 case 0:
648                         op->flags &= ~AFS_OPERATION_RETRY_SERVER;
649                         trace_afs_rotate(op, afs_rotate_trace_retry_server, 0);
650                         goto retry_server;
651                 case -ERESTARTSYS:
652                         afs_op_set_error(op, error);
653                         goto failed;
654                 case -ETIME:
655                 case -EDESTADDRREQ:
656                         goto next_server;
657                 }
658         }
659 
660 next_server:
661         trace_afs_rotate(op, afs_rotate_trace_next_server, 0);
662         _debug("next");
663         op->estate = NULL;
664         goto pick_server;
665 
666 no_more_servers:
667         /* That's all the servers poked to no good effect.  Try again if some
668          * of them were busy.
669          */
670         trace_afs_rotate(op, afs_rotate_trace_no_more_servers, 0);
671         if (op->flags & AFS_OPERATION_VBUSY) {
672                 afs_sleep_and_retry(op);
673                 op->flags &= ~AFS_OPERATION_VBUSY;
674                 goto restart_from_beginning;
675         }
676 
677         rcu_read_lock();
678         for (i = 0; i < op->server_list->nr_servers; i++) {
679                 struct afs_endpoint_state *estate;
680 
681                 estate = op->server_states[i].endpoint_state;
682                 error = READ_ONCE(estate->error);
683                 if (error < 0)
684                         afs_op_accumulate_error(op, error, estate->abort_code);
685         }
686         rcu_read_unlock();
687 
688 failed:
689         trace_afs_rotate(op, afs_rotate_trace_failed, 0);
690         op->flags |= AFS_OPERATION_STOP;
691         op->estate = NULL;
692         _leave(" = f [failed %d]", afs_op_error(op));
693         return false;
694 }
695 
696 /*
697  * Dump cursor state in the case of the error being EDESTADDRREQ.
698  */
699 void afs_dump_edestaddrreq(const struct afs_operation *op)
700 {
701         static int count;
702         int i;
703 
704         if (!IS_ENABLED(CONFIG_AFS_DEBUG_CURSOR) || count > 3)
705                 return;
706         count++;
707 
708         rcu_read_lock();
709 
710         pr_notice("EDESTADDR occurred\n");
711         pr_notice("OP: cbb=%x cbb2=%x fl=%x err=%hd\n",
712                   op->file[0].cb_break_before,
713                   op->file[1].cb_break_before, op->flags, op->cumul_error.error);
714         pr_notice("OP: ut=%lx ix=%d ni=%u\n",
715                   op->untried_servers, op->server_index, op->nr_iterations);
716         pr_notice("OP: call  er=%d ac=%d r=%u\n",
717                   op->call_error, op->call_abort_code, op->call_responded);
718 
719         if (op->server_list) {
720                 const struct afs_server_list *sl = op->server_list;
721 
722                 pr_notice("FC: SL nr=%u vnov=%hx\n",
723                           sl->nr_servers, sl->vnovol_mask);
724                 for (i = 0; i < sl->nr_servers; i++) {
725                         const struct afs_server *s = sl->servers[i].server;
726                         const struct afs_endpoint_state *e =
727                                 rcu_dereference(s->endpoint_state);
728                         const struct afs_addr_list *a = e->addresses;
729 
730                         pr_notice("FC: server fl=%lx av=%u %pU\n",
731                                   s->flags, s->addr_version, &s->uuid);
732                         pr_notice("FC:  - pq=%x R=%lx F=%lx\n",
733                                   e->probe_seq, e->responsive_set, e->failed_set);
734                         if (a) {
735                                 pr_notice("FC:  - av=%u nr=%u/%u/%u pr=%u\n",
736                                           a->version,
737                                           a->nr_ipv4, a->nr_addrs, a->max_addrs,
738                                           a->preferred);
739                                 if (a == e->addresses)
740                                         pr_notice("FC:  - current\n");
741                         }
742                 }
743         }
744 
745         pr_notice("AC: t=%lx ax=%d\n", op->addr_tried, op->addr_index);
746         rcu_read_unlock();
747 }
748 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

sflogo.php