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[fs/lustre-release.git] / lustre / ldlm / ldlm_request.c
1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
2  * vim:expandtab:shiftwidth=8:tabstop=8:
3  *
4  *  Copyright (C) 2002, 2003 Cluster File Systems, Inc.
5  *
6  *   This file is part of Lustre, http://www.lustre.org.
7  *
8  *   Lustre is free software; you can redistribute it and/or
9  *   modify it under the terms of version 2 of the GNU General Public
10  *   License as published by the Free Software Foundation.
11  *
12  *   Lustre is distributed in the hope that it will be useful,
13  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
14  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  *   GNU General Public License for more details.
16  *
17  *   You should have received a copy of the GNU General Public License
18  *   along with Lustre; if not, write to the Free Software
19  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20  */
21
22 #define DEBUG_SUBSYSTEM S_LDLM
23 #ifndef __KERNEL__
24 #include <signal.h>
25 #include <liblustre.h>
26 #endif
27
28 #include <linux/lustre_dlm.h>
29 #include <linux/obd_class.h>
30 #include <linux/obd.h>
31
32 #include "ldlm_internal.h"
33
34 static void interrupted_completion_wait(void *data)
35 {
36 }
37
38 struct lock_wait_data {
39         struct ldlm_lock *lwd_lock;
40         int               lwd_generation;
41 };
42
43 int ldlm_expired_completion_wait(void *data)
44 {
45         struct lock_wait_data *lwd = data;
46         struct ldlm_lock *lock = lwd->lwd_lock;
47         struct obd_import *imp;
48         struct obd_device *obd;
49
50         if (lock->l_conn_export == NULL) {
51                 static unsigned long next_dump = 0, last_dump = 0;
52
53                 if (ptlrpc_check_suspend())
54                         RETURN(0);
55
56                 LDLM_ERROR(lock, "lock timed out; not entering recovery in "
57                            "server code, just going back to sleep");
58                 if (time_after(jiffies, next_dump)) {
59                         last_dump = next_dump;
60                         next_dump = jiffies + 300 * HZ;
61                         ldlm_namespace_dump(D_DLMTRACE,
62                                             lock->l_resource->lr_namespace);
63                         if (last_dump == 0)
64                                 portals_debug_dumplog();
65                 }
66                 RETURN(0);
67         }
68
69         obd = lock->l_conn_export->exp_obd;
70         imp = obd->u.cli.cl_import;
71         ptlrpc_fail_import(imp, lwd->lwd_generation);
72         LDLM_ERROR(lock, "lock timed out, entering recovery for %s@%s",
73                    imp->imp_target_uuid.uuid,
74                    imp->imp_connection->c_remote_uuid.uuid);
75
76         RETURN(0);
77 }
78
79 int ldlm_completion_ast(struct ldlm_lock *lock, int flags, void *data)
80 {
81         /* XXX ALLOCATE - 160 bytes */
82         struct lock_wait_data lwd;
83         unsigned long irqflags;
84         struct obd_device *obd;
85         struct obd_import *imp = NULL;
86         struct l_wait_info lwi;
87         int rc = 0;
88         ENTRY;
89
90         if (flags == LDLM_FL_WAIT_NOREPROC)
91                 goto noreproc;
92
93         if (!(flags & (LDLM_FL_BLOCK_WAIT | LDLM_FL_BLOCK_GRANTED |
94                        LDLM_FL_BLOCK_CONV))) {
95                 wake_up(&lock->l_waitq);
96                 RETURN(0);
97         }
98
99         LDLM_DEBUG(lock, "client-side enqueue returned a blocked lock, "
100                    "sleeping");
101         ldlm_lock_dump(D_OTHER, lock, 0);
102         ldlm_reprocess_all(lock->l_resource);
103
104 noreproc:
105
106         obd = class_exp2obd(lock->l_conn_export);
107
108         /* if this is a local lock, then there is no import */
109         if (obd != NULL)
110                 imp = obd->u.cli.cl_import;
111
112         lwd.lwd_lock = lock;
113
114         if (flags & LDLM_FL_NO_TIMEOUT) {
115                 LDLM_DEBUG(lock, "waiting indefinitely for group lock\n");
116                 lwi = LWI_INTR(interrupted_completion_wait, &lwd);
117         } else {
118                 lwi = LWI_TIMEOUT_INTR(obd_timeout * HZ,
119                                        ldlm_expired_completion_wait,
120                                        interrupted_completion_wait, &lwd);
121         }
122
123         if (imp != NULL) {
124                 spin_lock_irqsave(&imp->imp_lock, irqflags);
125                 lwd.lwd_generation = imp->imp_generation;
126                 spin_unlock_irqrestore(&imp->imp_lock, irqflags);
127         }
128
129         /* Go to sleep until the lock is granted or cancelled. */
130         rc = l_wait_event(lock->l_waitq,
131                           ((lock->l_req_mode == lock->l_granted_mode) ||
132                            (lock->l_flags & LDLM_FL_FAILED)), &lwi);
133
134         if (lock->l_destroyed || lock->l_flags & LDLM_FL_FAILED) {
135                 LDLM_DEBUG(lock, "client-side enqueue waking up: destroyed");
136                 RETURN(-EIO);
137         }
138
139         if (rc) {
140                 LDLM_DEBUG(lock, "client-side enqueue waking up: failed (%d)",
141                            rc);
142                 RETURN(rc);
143         }
144
145         LDLM_DEBUG(lock, "client-side enqueue waking up: granted");
146         RETURN(0);
147 }
148
149 static int ldlm_cli_enqueue_local(struct ldlm_namespace *ns,
150                                   struct ldlm_res_id res_id,
151                                   __u32 type,
152                                   ldlm_policy_data_t *policy,
153                                   ldlm_mode_t mode,
154                                   int *flags,
155                                   ldlm_blocking_callback blocking,
156                                   ldlm_completion_callback completion,
157                                   ldlm_glimpse_callback glimpse,
158                                   void *data, __u32 lvb_len,
159                                   void *lvb_swabber,
160                                   struct lustre_handle *lockh)
161 {
162         struct ldlm_lock *lock;
163         int err;
164         ENTRY;
165
166         if (ns->ns_client) {
167                 CERROR("Trying to enqueue local lock in a shadow namespace\n");
168                 LBUG();
169         }
170
171         lock = ldlm_lock_create(ns, NULL, res_id, type, mode, blocking,
172                                 completion, glimpse, data, lvb_len);
173         if (!lock)
174                 GOTO(out_nolock, err = -ENOMEM);
175         LDLM_DEBUG(lock, "client-side local enqueue handler, new lock created");
176
177         ldlm_lock_addref_internal(lock, mode);
178         ldlm_lock2handle(lock, lockh);
179         lock->l_flags |= LDLM_FL_LOCAL;
180         if (*flags & LDLM_FL_ATOMIC_CB)
181                 lock->l_flags |= LDLM_FL_ATOMIC_CB;
182         lock->l_lvb_swabber = lvb_swabber;
183         if (policy != NULL)
184                 memcpy(&lock->l_policy_data, policy, sizeof(*policy));
185         if (type == LDLM_EXTENT)
186                 memcpy(&lock->l_req_extent, &policy->l_extent,
187                        sizeof(policy->l_extent));
188
189         err = ldlm_lock_enqueue(ns, &lock, policy, flags);
190         if (err != ELDLM_OK)
191                 GOTO(out, err);
192
193         if (policy != NULL)
194                 memcpy(policy, &lock->l_policy_data, sizeof(*policy));
195         if ((*flags) & LDLM_FL_LOCK_CHANGED)
196                 memcpy(&res_id, &lock->l_resource->lr_name, sizeof(res_id));
197
198         LDLM_DEBUG_NOLOCK("client-side local enqueue handler END (lock %p)",
199                           lock);
200
201         if (lock->l_completion_ast)
202                 lock->l_completion_ast(lock, *flags, NULL);
203
204         LDLM_DEBUG(lock, "client-side local enqueue END");
205         EXIT;
206  out:
207         LDLM_LOCK_PUT(lock);
208  out_nolock:
209         return err;
210 }
211
212 static void failed_lock_cleanup(struct ldlm_namespace *ns,
213                                 struct ldlm_lock *lock,
214                                 struct lustre_handle *lockh, int mode)
215 {
216         /* Set a flag to prevent us from sending a CANCEL (bug 407) */
217         lock_res(lock->l_resource);
218         lock->l_flags |= LDLM_FL_LOCAL_ONLY;
219         unlock_res(lock->l_resource);
220         LDLM_DEBUG(lock, "setting FL_LOCAL_ONLY");
221
222         ldlm_lock_decref_and_cancel(lockh, mode);
223
224         /* XXX - HACK because we shouldn't call ldlm_lock_destroy()
225          *       from llite/file.c/ll_file_flock(). */
226         if (lock->l_resource->lr_type == LDLM_FLOCK) {
227                 ldlm_lock_destroy(lock);
228         }
229 }
230
231 int ldlm_cli_enqueue(struct obd_export *exp,
232                      struct ptlrpc_request *req,
233                      struct ldlm_namespace *ns,
234                      struct ldlm_res_id res_id,
235                      __u32 type,
236                      ldlm_policy_data_t *policy,
237                      ldlm_mode_t mode,
238                      int *flags,
239                      ldlm_blocking_callback blocking,
240                      ldlm_completion_callback completion,
241                      ldlm_glimpse_callback glimpse,
242                      void *data,
243                      void *lvb,
244                      __u32 lvb_len,
245                      void *lvb_swabber,
246                      struct lustre_handle *lockh)
247 {
248         struct ldlm_lock *lock;
249         struct ldlm_request *body;
250         struct ldlm_reply *reply;
251         int rc, size[3] = {0, sizeof(*body), lvb_len}, req_passed_in = 1;
252         int is_replay = *flags & LDLM_FL_REPLAY;
253         int cleanup_phase = 0;
254         ENTRY;
255
256         if (exp == NULL) {
257                 LASSERT(!is_replay);
258                 rc = ldlm_cli_enqueue_local(ns, res_id, type, policy, mode,
259                                             flags, blocking, completion,
260                                             glimpse, data, lvb_len, lvb_swabber,
261                                             lockh);
262                 RETURN(rc);
263         }
264
265         /* If we're replaying this lock, just check some invariants.
266          * If we're creating a new lock, get everything all setup nice. */
267         if (is_replay) {
268                 lock = ldlm_handle2lock(lockh);
269                 LDLM_DEBUG(lock, "client-side enqueue START");
270                 LASSERT(exp == lock->l_conn_export);
271         } else {
272                 lock = ldlm_lock_create(ns, NULL, res_id, type, mode, blocking,
273                                         completion, glimpse, data, lvb_len);
274                 if (lock == NULL)
275                         RETURN(-ENOMEM);
276                 /* for the local lock, add the reference */
277                 ldlm_lock_addref_internal(lock, mode);
278                 ldlm_lock2handle(lock, lockh);
279                 lock->l_lvb_swabber = lvb_swabber;
280                 if (policy != NULL)
281                         memcpy(&lock->l_policy_data, policy, sizeof(*policy));
282                 if (type == LDLM_EXTENT)
283                         memcpy(&lock->l_req_extent, &policy->l_extent,
284                                sizeof(policy->l_extent));
285                 LDLM_DEBUG(lock, "client-side enqueue START");
286         }
287
288         /* lock not sent to server yet */
289         cleanup_phase = 2;
290
291         if (req == NULL) {
292                 req = ptlrpc_prep_req(class_exp2cliimp(exp), LUSTRE_DLM_VERSION,
293                                       LDLM_ENQUEUE, 2, size, NULL);
294                 if (req == NULL)
295                         GOTO(cleanup, rc = -ENOMEM);
296                 req_passed_in = 0;
297         }
298
299         LASSERTF(req->rq_reqmsg->buflens[MDS_REQ_INTENT_LOCKREQ_OFF] ==
300                  sizeof(*body), "buflen[%d] = %d, not %d\n",
301                  MDS_REQ_INTENT_LOCKREQ_OFF,
302                  req->rq_reqmsg->buflens[MDS_REQ_INTENT_LOCKREQ_OFF],
303                  sizeof(*body));
304
305         /* Dump lock data into the request buffer */
306         body = lustre_msg_buf(req->rq_reqmsg, MDS_REQ_INTENT_LOCKREQ_OFF,
307                               sizeof (*body));
308         ldlm_lock2desc(lock, &body->lock_desc);
309         body->lock_flags = *flags;
310
311         memcpy(&body->lock_handle1, lockh, sizeof(*lockh));
312
313         /* Continue as normal. */
314         if (!req_passed_in) {
315                 size[0] = sizeof(*reply);
316                 req->rq_replen = lustre_msg_size(1 + (lvb_len > 0), size);
317         }
318         lock->l_conn_export = exp;
319         lock->l_export = NULL;
320         lock->l_blocking_ast = blocking;
321
322         LDLM_DEBUG(lock, "sending request");
323         rc = ptlrpc_queue_wait(req);
324
325         if (rc != ELDLM_OK) {
326                 LASSERT(!is_replay);
327                 LDLM_DEBUG(lock, "client-side enqueue END (%s)",
328                            rc == ELDLM_LOCK_ABORTED ? "ABORTED" : "FAILED");
329                 if (rc == ELDLM_LOCK_ABORTED) {
330                         /* Before we return, swab the reply */
331                         reply = lustre_swab_repbuf(req, 0, sizeof(*reply),
332                                                    lustre_swab_ldlm_reply);
333                         if (reply == NULL) {
334                                 CERROR("Can't unpack ldlm_reply\n");
335                                 rc = -EPROTO;
336                         }
337                         if (lvb_len) {
338                                 void *tmplvb;
339                                 tmplvb = lustre_swab_repbuf(req, 1, lvb_len,
340                                                             lvb_swabber);
341                                 if (tmplvb == NULL)
342                                         GOTO(cleanup, rc = -EPROTO);
343                                 if (lvb != NULL)
344                                         memcpy(lvb, tmplvb, lvb_len);
345                         }
346                 }
347                 GOTO(cleanup, rc);
348         }
349
350         reply = lustre_swab_repbuf(req, 0, sizeof(*reply),
351                                    lustre_swab_ldlm_reply);
352         if (reply == NULL) {
353                 CERROR("Can't unpack ldlm_reply\n");
354                 GOTO(cleanup, rc = -EPROTO);
355         }
356
357         /* lock enqueued on the server */
358         cleanup_phase = 1;
359
360         memcpy(&lock->l_remote_handle, &reply->lock_handle,
361                sizeof(lock->l_remote_handle));
362         *flags = reply->lock_flags;
363
364         CDEBUG(D_INFO, "local: %p, remote cookie: "LPX64", flags: 0x%x\n",
365                lock, reply->lock_handle.cookie, *flags);
366
367         /* If enqueue returned a blocked lock but the completion handler has
368          * already run, then it fixed up the resource and we don't need to do it
369          * again. */
370         if ((*flags) & LDLM_FL_LOCK_CHANGED) {
371                 int newmode = reply->lock_desc.l_req_mode;
372                 LASSERT(!is_replay);
373                 if (newmode && newmode != lock->l_req_mode) {
374                         LDLM_DEBUG(lock, "server returned different mode %s",
375                                    ldlm_lockname[newmode]);
376                         lock->l_req_mode = newmode;
377                 }
378
379                 if (reply->lock_desc.l_resource.lr_name.name[0] !=
380                     lock->l_resource->lr_name.name[0] ||
381                    reply->lock_desc.l_resource.lr_name.name[1] !=
382                     lock->l_resource->lr_name.name[1]) {
383                         CDEBUG(D_INFO, "remote intent success, locking %ld "
384                                "instead of %ld\n",
385                               (long)reply->lock_desc.l_resource.lr_name.name[0],
386                                (long)lock->l_resource->lr_name.name[0]);
387
388                         ldlm_lock_change_resource(ns, lock,
389                                            reply->lock_desc.l_resource.lr_name);
390                         if (lock->l_resource == NULL) {
391                                 LBUG();
392                                 GOTO(cleanup, rc = -ENOMEM);
393                         }
394                         LDLM_DEBUG(lock, "client-side enqueue, new resource");
395                 }
396                 if (policy != NULL)
397                         memcpy(&lock->l_policy_data,
398                                &reply->lock_desc.l_policy_data,
399                                sizeof(reply->lock_desc.l_policy_data));
400                 if (type != LDLM_PLAIN)
401                         LDLM_DEBUG(lock,"client-side enqueue, new policy data");
402         }
403
404         if ((*flags) & LDLM_FL_AST_SENT) {
405                 lock_res(lock->l_resource);
406                 lock->l_flags |= LDLM_FL_CBPENDING;
407                 unlock_res(lock->l_resource);
408                 LDLM_DEBUG(lock, "enqueue reply includes blocking AST");
409         }
410
411         /* If the lock has already been granted by a completion AST, don't
412          * clobber the LVB with an older one. */
413         if (lvb_len && (lock->l_req_mode != lock->l_granted_mode)) {
414                 void *tmplvb;
415                 tmplvb = lustre_swab_repbuf(req, 1, lvb_len, lvb_swabber);
416                 if (tmplvb == NULL) {
417                         cleanup_phase = 2;
418                         GOTO(cleanup, rc = -EPROTO);
419                 }
420                 memcpy(lock->l_lvb_data, tmplvb, lvb_len);
421         }
422
423         if (!is_replay) {
424                 rc = ldlm_lock_enqueue(ns, &lock, NULL, flags);
425                 if (lock->l_completion_ast != NULL) {
426                         int err = lock->l_completion_ast(lock, *flags, NULL);
427                         if (!rc)
428                                 rc = err;
429                         if (rc)
430                                 cleanup_phase = 2;
431                 }
432         }
433
434         if (lvb_len && lvb != NULL) {
435                 /* Copy the LVB here, and not earlier, because the completion
436                  * AST (if any) can override what we got in the reply */
437                 memcpy(lvb, lock->l_lvb_data, lvb_len);
438         }
439
440         LDLM_DEBUG(lock, "client-side enqueue END");
441         EXIT;
442 cleanup:
443         switch (cleanup_phase) {
444         case 2:
445                 if (rc)
446                         failed_lock_cleanup(ns, lock, lockh, mode);
447         case 1:
448                 if (!req_passed_in && req != NULL)
449                         ptlrpc_req_finished(req);
450         }
451
452         LDLM_LOCK_PUT(lock);
453         return rc;
454 }
455
456 static int ldlm_cli_convert_local(struct ldlm_lock *lock, int new_mode,
457                                   int *flags)
458 {
459         struct ldlm_resource *res;
460         int rc;
461         ENTRY;
462         if (lock->l_resource->lr_namespace->ns_client) {
463                 CERROR("Trying to cancel local lock\n");
464                 LBUG();
465         }
466         LDLM_DEBUG(lock, "client-side local convert");
467
468         res = ldlm_lock_convert(lock, new_mode, flags);
469         if (res) {
470                 ldlm_reprocess_all(res);
471                 rc = 0;
472         } else {
473                 rc = EDEADLOCK;
474         }
475         LDLM_DEBUG(lock, "client-side local convert handler END");
476         LDLM_LOCK_PUT(lock);
477         RETURN(rc);
478 }
479
480 /* FIXME: one of ldlm_cli_convert or the server side should reject attempted
481  * conversion of locks which are on the waiting or converting queue */
482 /* Caller of this code is supposed to take care of lock readers/writers
483    accounting */
484 int ldlm_cli_convert(struct lustre_handle *lockh, int new_mode, int *flags)
485 {
486         struct ldlm_request *body;
487         struct ldlm_reply *reply;
488         struct ldlm_lock *lock;
489         struct ldlm_resource *res;
490         struct ptlrpc_request *req = NULL;
491         int rc, size = sizeof(*body);
492         ENTRY;
493
494         lock = ldlm_handle2lock(lockh);
495         if (!lock) {
496                 LBUG();
497                 RETURN(-EINVAL);
498         }
499         *flags = 0;
500
501         if (lock->l_conn_export == NULL)
502                 RETURN(ldlm_cli_convert_local(lock, new_mode, flags));
503
504         LDLM_DEBUG(lock, "client-side convert");
505
506         req = ptlrpc_prep_req(class_exp2cliimp(lock->l_conn_export),
507                               LUSTRE_DLM_VERSION, LDLM_CONVERT, 1, &size, NULL);
508         if (!req)
509                 GOTO(out, rc = -ENOMEM);
510
511         body = lustre_msg_buf(req->rq_reqmsg, 0, sizeof (*body));
512         memcpy(&body->lock_handle1, &lock->l_remote_handle,
513                sizeof(body->lock_handle1));
514
515         body->lock_desc.l_req_mode = new_mode;
516         body->lock_flags = *flags;
517
518         size = sizeof(*reply);
519         req->rq_replen = lustre_msg_size(1, &size);
520
521         rc = ptlrpc_queue_wait(req);
522         if (rc != ELDLM_OK)
523                 GOTO(out, rc);
524
525         reply = lustre_swab_repbuf(req, 0, sizeof (*reply),
526                                    lustre_swab_ldlm_reply);
527         if (reply == NULL) {
528                 CERROR ("Can't unpack ldlm_reply\n");
529                 GOTO (out, rc = -EPROTO);
530         }
531
532         if (req->rq_status)
533                 GOTO(out, rc = req->rq_status);
534
535         res = ldlm_lock_convert(lock, new_mode,
536                                 (int *)&reply->lock_flags);
537         if (res != NULL) {
538                 ldlm_reprocess_all(res);
539                 /* Go to sleep until the lock is granted. */
540                 /* FIXME: or cancelled. */
541                 if (lock->l_completion_ast) {
542                         rc = lock->l_completion_ast(lock, LDLM_FL_WAIT_NOREPROC,
543                                                     NULL);
544                         if (rc)
545                                 GOTO(out, rc);
546                 }
547         } else {
548                 rc = EDEADLOCK;
549         }
550         EXIT;
551  out:
552         LDLM_LOCK_PUT(lock);
553         ptlrpc_req_finished(req);
554         return rc;
555 }
556
557 int ldlm_cli_cancel(struct lustre_handle *lockh)
558 {
559         struct ptlrpc_request *req;
560         struct ldlm_lock *lock;
561         struct ldlm_request *body;
562         int rc = 0, size = sizeof(*body);
563         ENTRY;
564
565         /* concurrent cancels on the same handle can happen */
566         lock = __ldlm_handle2lock(lockh, LDLM_FL_CANCELING);
567         if (lock == NULL)
568                 RETURN(0);
569
570         if (lock->l_conn_export) {
571                 int local_only;
572                 struct obd_import *imp;
573
574                 LDLM_DEBUG(lock, "client-side cancel");
575                 /* Set this flag to prevent others from getting new references*/
576                 lock_res(lock->l_resource);
577                 lock->l_flags |= LDLM_FL_CBPENDING;
578                 local_only = lock->l_flags & LDLM_FL_LOCAL_ONLY;
579                 ldlm_cancel_callback(lock);
580                 unlock_res(lock->l_resource);
581
582                 if (local_only) {
583                         CDEBUG(D_INFO, "not sending request (at caller's "
584                                "instruction)\n");
585                         goto local_cancel;
586                 }
587
588         restart:
589                 imp = class_exp2cliimp(lock->l_conn_export);
590                 if (imp == NULL || imp->imp_invalid) {
591                         CDEBUG(D_HA, "skipping cancel on invalid import %p\n",
592                                imp);
593                         goto local_cancel;
594                 }
595
596                 req = ptlrpc_prep_req(imp, LUSTRE_DLM_VERSION, LDLM_CANCEL,
597                                       1, &size, NULL);
598                 if (!req)
599                         GOTO(out, rc = -ENOMEM);
600                 req->rq_no_resend = 1;
601
602                 /* XXX FIXME bug 249 */
603                 req->rq_request_portal = LDLM_CANCEL_REQUEST_PORTAL;
604                 req->rq_reply_portal = LDLM_CANCEL_REPLY_PORTAL;
605
606                 body = lustre_msg_buf(req->rq_reqmsg, 0, sizeof (*body));
607                 memcpy(&body->lock_handle1, &lock->l_remote_handle,
608                        sizeof(body->lock_handle1));
609
610                 req->rq_replen = lustre_msg_size(0, NULL);
611
612                 rc = ptlrpc_queue_wait(req);
613
614                 if (rc == ESTALE) {
615                         char str[PTL_NALFMT_SIZE];
616                         CERROR("client/server (nid %s) out of sync"
617                                " -- not fatal\n",
618                                ptlrpc_peernid2str(&req->rq_import->
619                                                   imp_connection->c_peer, str));
620                 } else if (rc == -ETIMEDOUT) {
621                         ptlrpc_req_finished(req);
622                         GOTO(restart, rc);
623                 } else if (rc != ELDLM_OK) {
624                         CERROR("Got rc %d from cancel RPC: canceling "
625                                "anyway\n", rc);
626                 }
627
628                 ptlrpc_req_finished(req);
629         local_cancel:
630                 ldlm_lock_cancel(lock);
631         } else {
632                 if (lock->l_resource->lr_namespace->ns_client) {
633                         LDLM_ERROR(lock, "Trying to cancel local lock\n");
634                         LBUG();
635                 }
636                 LDLM_DEBUG(lock, "client-side local cancel");
637                 ldlm_lock_cancel(lock);
638                 ldlm_reprocess_all(lock->l_resource);
639                 LDLM_DEBUG(lock, "client-side local cancel handler END");
640         }
641
642         EXIT;
643  out:
644         LDLM_LOCK_PUT(lock);
645         return rc;
646 }
647
648 /* when called with LDLM_ASYNC the blocking callback will be handled
649  * in a thread and this function will return after the thread has been
650  * asked to call the callback.  when called with LDLM_SYNC the blocking
651  * callback will be performed in this function. */
652 int ldlm_cancel_lru(struct ldlm_namespace *ns, ldlm_sync_t sync)
653 {
654         struct ldlm_lock *lock, *next;
655         int count, rc = 0;
656         LIST_HEAD(cblist);
657         ENTRY;
658
659 #ifndef __KERNEL__
660         sync = LDLM_SYNC; /* force to be sync in user space */
661 #endif
662
663         spin_lock(&ns->ns_unused_lock);
664         count = ns->ns_nr_unused - ns->ns_max_unused;
665
666         if (count <= 0) {
667                 spin_unlock(&ns->ns_unused_lock);
668                 RETURN(0);
669         }
670
671         while (!list_empty(&ns->ns_unused_list)) {
672                 struct list_head *tmp = ns->ns_unused_list.next;
673                 lock = list_entry(tmp, struct ldlm_lock, l_lru);
674                 LASSERT(!lock->l_readers && !lock->l_writers);
675
676                 LDLM_LOCK_GET(lock); /* dropped by bl thread */
677                 spin_unlock(&ns->ns_unused_lock);
678
679                 lock_res(lock->l_resource);
680                 ldlm_lock_remove_from_lru(lock);
681
682                 /* Setting the CBPENDING flag is a little misleading, but
683                  * prevents an important race; namely, once CBPENDING is set,
684                  * the lock can accumulate no more readers/writers.  Since
685                  * readers and writers are already zero here, ldlm_lock_decref
686                  * won't see this flag and call l_blocking_ast */
687                 lock->l_flags |= LDLM_FL_CBPENDING;
688
689                 /* We can't re-add to l_lru as it confuses the refcounting in
690                  * ldlm_lock_remove_from_lru() if an AST arrives after we drop
691                  * ns_lock below. We use l_tmp and can't use l_pending_chain as
692                  * it is used both on server and client nevertheles bug 5666
693                  * says it is used only on server. --umka */
694                 if (sync != LDLM_ASYNC || ldlm_bl_to_thread(ns, NULL, lock))                        
695                         list_add(&lock->l_tmp, &cblist);
696
697                 unlock_res(lock->l_resource);
698
699                 spin_lock(&ns->ns_unused_lock);
700
701                 if (--count == 0)
702                         break;
703         }
704         spin_unlock(&ns->ns_unused_lock);
705
706         list_for_each_entry_safe(lock, next, &cblist, l_tmp) {
707                 list_del_init(&lock->l_tmp);
708                 ldlm_handle_bl_callback(ns, NULL, lock);
709         }
710
711         RETURN(rc);
712 }
713
714 static int ldlm_cli_cancel_unused_resource(struct ldlm_namespace *ns,
715                                            struct ldlm_res_id res_id, int flags,
716                                            void *opaque)
717 {
718         struct list_head *tmp, *next, list = LIST_HEAD_INIT(list);
719         struct ldlm_resource *res;
720         struct ldlm_lock *lock;
721         ENTRY;
722
723         res = ldlm_resource_get(ns, NULL, res_id, 0, 0);
724         if (res == NULL) {
725                 /* This is not a problem. */
726                 CDEBUG(D_INFO, "No resource "LPU64"\n", res_id.name[0]);
727                 RETURN(0);
728         }
729
730         lock_res(res);
731         list_for_each(tmp, &res->lr_granted) {
732                 lock = list_entry(tmp, struct ldlm_lock, l_res_link);
733
734                 if (opaque != NULL && lock->l_ast_data != opaque) {
735                         LDLM_ERROR(lock, "data %p doesn't match opaque %p",
736                                    lock->l_ast_data, opaque);
737                         continue;
738                 }
739
740                 if (lock->l_readers || lock->l_writers) {
741                         if (flags & LDLM_FL_CONFIG_CHANGE)
742                                 lock->l_flags |= LDLM_FL_CBPENDING;
743                         else if (flags & LDLM_FL_WARN)
744                                 LDLM_ERROR(lock, "lock in use");
745                         continue;
746                 }
747
748                 /* See CBPENDING comment in ldlm_cancel_lru */
749                 lock->l_flags |= LDLM_FL_CBPENDING;
750
751                 LASSERT(list_empty(&lock->l_bl_ast));
752                 list_add(&lock->l_bl_ast, &list);
753                 LDLM_LOCK_GET(lock);
754         }
755         unlock_res(res);
756
757         list_for_each_safe(tmp, next, &list) {
758                 struct lustre_handle lockh;
759                 int rc;
760                 lock = list_entry(tmp, struct ldlm_lock, l_bl_ast);
761
762                 if (flags & LDLM_FL_LOCAL_ONLY) {
763                         ldlm_lock_cancel(lock);
764                 } else {
765                         ldlm_lock2handle(lock, &lockh);
766                         rc = ldlm_cli_cancel(&lockh);
767                         if (rc != ELDLM_OK)
768                                 CERROR("ldlm_cli_cancel: %d\n", rc);
769                 }
770                 list_del_init(&lock->l_bl_ast);
771                 LDLM_LOCK_PUT(lock);
772         }
773
774         ldlm_resource_putref(res);
775
776         RETURN(0);
777 }
778
779 static inline int have_no_nsresource(struct ldlm_namespace *ns)
780 {
781         int no_resource = 0;
782
783         spin_lock(&ns->ns_hash_lock);
784         if (ns->ns_resources == 0)
785                 no_resource = 1;
786         spin_unlock(&ns->ns_hash_lock);
787
788         RETURN(no_resource);
789 }
790
791 /* Cancel all locks on a namespace (or a specific resource, if given)
792  * that have 0 readers/writers.
793  *
794  * If flags & LDLM_FL_LOCAL_ONLY, throw the locks away without trying
795  * to notify the server.
796  * If flags & LDLM_FL_NO_CALLBACK, don't run the cancel callback.
797  * If flags & LDLM_FL_WARN, print a warning if some locks are still in use. 
798  * If flags & LDLM_FL_CONFIG_CHANGE, mark all locks as having a pending callback
799  */
800 int ldlm_cli_cancel_unused(struct ldlm_namespace *ns,
801                            struct ldlm_res_id *res_id, int flags, void *opaque)
802 {
803         int i;
804         struct l_wait_info lwi = { 0 };
805         ENTRY;
806
807         if (ns == NULL)
808                 RETURN(ELDLM_OK);
809
810         if (res_id)
811                 RETURN(ldlm_cli_cancel_unused_resource(ns, *res_id, flags,
812                                                        opaque));
813
814         spin_lock(&ns->ns_hash_lock);
815         for (i = 0; i < RES_HASH_SIZE; i++) {
816                 struct list_head *tmp;
817                 tmp = ns->ns_hash[i].next;
818                 while (tmp != &(ns->ns_hash[i])) {
819                         struct ldlm_resource *res;
820                         int rc;
821
822                         res = list_entry(tmp, struct ldlm_resource, lr_hash);
823                         ldlm_resource_getref(res);
824                         spin_unlock(&ns->ns_hash_lock);
825
826                         rc = ldlm_cli_cancel_unused_resource(ns, res->lr_name,
827                                                              flags, opaque);
828                         if (rc)
829                                 CERROR("cancel_unused_res ("LPU64"): %d\n",
830                                        res->lr_name.name[0], rc);
831
832                         spin_lock(&ns->ns_hash_lock);
833                         tmp = tmp->next;
834                         ldlm_resource_putref_locked(res);
835                 }
836         }
837         spin_unlock(&ns->ns_hash_lock);
838
839         if (flags & LDLM_FL_CONFIG_CHANGE)
840                 l_wait_event(ns->ns_waitq, have_no_nsresource(ns), &lwi);
841
842         RETURN(ELDLM_OK);
843 }
844
845 /* Lock iterators. */
846
847 int ldlm_resource_foreach(struct ldlm_resource *res, ldlm_iterator_t iter,
848                           void *closure)
849 {
850         struct list_head *tmp, *next;
851         struct ldlm_lock *lock;
852         int rc = LDLM_ITER_CONTINUE;
853
854         ENTRY;
855
856         if (!res)
857                 RETURN(LDLM_ITER_CONTINUE);
858
859         lock_res(res);
860         list_for_each_safe(tmp, next, &res->lr_granted) {
861                 lock = list_entry(tmp, struct ldlm_lock, l_res_link);
862
863                 if (iter(lock, closure) == LDLM_ITER_STOP)
864                         GOTO(out, rc = LDLM_ITER_STOP);
865         }
866
867         list_for_each_safe(tmp, next, &res->lr_converting) {
868                 lock = list_entry(tmp, struct ldlm_lock, l_res_link);
869
870                 if (iter(lock, closure) == LDLM_ITER_STOP)
871                         GOTO(out, rc = LDLM_ITER_STOP);
872         }
873
874         list_for_each_safe(tmp, next, &res->lr_waiting) {
875                 lock = list_entry(tmp, struct ldlm_lock, l_res_link);
876
877                 if (iter(lock, closure) == LDLM_ITER_STOP)
878                         GOTO(out, rc = LDLM_ITER_STOP);
879         }
880  out:
881         unlock_res(res);
882         RETURN(rc);
883 }
884
885 struct iter_helper_data {
886         ldlm_iterator_t iter;
887         void *closure;
888 };
889
890 static int ldlm_iter_helper(struct ldlm_lock *lock, void *closure)
891 {
892         struct iter_helper_data *helper = closure;
893         return helper->iter(lock, helper->closure);
894 }
895
896 static int ldlm_res_iter_helper(struct ldlm_resource *res, void *closure)
897 {
898         return ldlm_resource_foreach(res, ldlm_iter_helper, closure);
899 }
900
901 int ldlm_namespace_foreach(struct ldlm_namespace *ns, ldlm_iterator_t iter,
902                            void *closure)
903 {
904         struct iter_helper_data helper = { iter: iter, closure: closure };
905         return ldlm_namespace_foreach_res(ns, ldlm_res_iter_helper, &helper);
906 }
907
908 int ldlm_namespace_foreach_res(struct ldlm_namespace *ns,
909                                ldlm_res_iterator_t iter, void *closure)
910 {
911         int i, rc = LDLM_ITER_CONTINUE;
912         struct ldlm_resource *res;
913         struct list_head *tmp;
914
915         spin_lock(&ns->ns_hash_lock);
916         for (i = 0; i < RES_HASH_SIZE; i++) {
917                 tmp = ns->ns_hash[i].next;
918                 while (tmp != &(ns->ns_hash[i])) {
919                         res = list_entry(tmp, struct ldlm_resource, lr_hash);
920                         ldlm_resource_getref(res);
921                         spin_unlock(&ns->ns_hash_lock);
922
923                         rc = iter(res, closure);
924
925                         spin_lock(&ns->ns_hash_lock);
926                         tmp = tmp->next;
927                         ldlm_resource_putref_locked(res);
928                         if (rc == LDLM_ITER_STOP)
929                                 GOTO(out, rc);
930                 }
931         }
932  out:
933         spin_unlock(&ns->ns_hash_lock);
934         RETURN(rc);
935 }
936
937 /* non-blocking function to manipulate a lock whose cb_data is being put away.*/
938 void ldlm_change_cbdata(struct ldlm_namespace *ns, 
939                         struct ldlm_res_id *res_id,
940                         ldlm_iterator_t iter, 
941                         void *data)
942 {
943         struct ldlm_resource *res;
944         ENTRY;
945
946         if (ns == NULL) {
947                 CERROR("must pass in namespace\n");
948                 LBUG();
949         }
950
951         res = ldlm_resource_get(ns, NULL, *res_id, 0, 0);
952         if (res == NULL) {
953                 EXIT;
954                 return;
955         }
956
957         ldlm_resource_foreach(res, iter, data);
958         ldlm_resource_putref(res);
959         EXIT;
960 }
961
962 /* Lock replay */
963
964 static int ldlm_chain_lock_for_replay(struct ldlm_lock *lock, void *closure)
965 {
966         struct list_head *list = closure;
967
968         /* we use l_pending_chain here, because it's unused on clients. */
969         list_add(&lock->l_pending_chain, list);
970         return LDLM_ITER_CONTINUE;
971 }
972
973 static int replay_lock_interpret(struct ptlrpc_request *req,
974                                     void * data, int rc)
975 {
976         struct ldlm_lock *lock;
977         struct ldlm_reply *reply;
978
979         atomic_dec(&req->rq_import->imp_replay_inflight);
980         if (rc != ELDLM_OK)
981                 GOTO(out, rc);
982
983         lock = req->rq_async_args.pointer_arg[0];
984         LASSERT(lock != NULL);
985
986         reply = lustre_swab_repbuf(req, 0, sizeof (*reply),
987                                    lustre_swab_ldlm_reply);
988         if (reply == NULL) {
989                 CERROR("Can't unpack ldlm_reply\n");
990                 GOTO (out, rc = -EPROTO);
991         }
992
993         memcpy(&lock->l_remote_handle, &reply->lock_handle,
994                sizeof(lock->l_remote_handle));
995         LDLM_DEBUG(lock, "replayed lock:");
996         ptlrpc_import_recovery_state_machine(req->rq_import);
997 out:
998         if (rc != ELDLM_OK)
999                 ptlrpc_connect_import(req->rq_import, NULL);
1000
1001         RETURN(rc);
1002 }
1003
1004 static int replay_one_lock(struct obd_import *imp, struct ldlm_lock *lock)
1005 {
1006         struct ptlrpc_request *req;
1007         struct ldlm_request *body;
1008         struct ldlm_reply *reply;
1009         int buffers = 1;
1010         int size[2] = {0, sizeof(*body)};
1011         int flags;
1012
1013         /*
1014          * If granted mode matches the requested mode, this lock is granted.
1015          *
1016          * If they differ, but we have a granted mode, then we were granted
1017          * one mode and now want another: ergo, converting.
1018          *
1019          * If we haven't been granted anything and are on a resource list,
1020          * then we're blocked/waiting.
1021          *
1022          * If we haven't been granted anything and we're NOT on a resource list,
1023          * then we haven't got a reply yet and don't have a known disposition.
1024          * This happens whenever a lock enqueue is the request that triggers
1025          * recovery.
1026          */
1027         if (lock->l_granted_mode == lock->l_req_mode)
1028                 flags = LDLM_FL_REPLAY | LDLM_FL_BLOCK_GRANTED;
1029         else if (lock->l_granted_mode)
1030                 flags = LDLM_FL_REPLAY | LDLM_FL_BLOCK_CONV;
1031         else if (!list_empty(&lock->l_res_link))
1032                 flags = LDLM_FL_REPLAY | LDLM_FL_BLOCK_WAIT;
1033         else
1034                 flags = LDLM_FL_REPLAY;
1035
1036         req = ptlrpc_prep_req(imp, LUSTRE_DLM_VERSION, LDLM_ENQUEUE,
1037                               2, size, NULL);
1038         if (!req)
1039                 RETURN(-ENOMEM);
1040
1041         /* We're part of recovery, so don't wait for it. */
1042         req->rq_send_state = LUSTRE_IMP_REPLAY_LOCKS;
1043
1044         body = lustre_msg_buf(req->rq_reqmsg, 1, sizeof (*body));
1045         ldlm_lock2desc(lock, &body->lock_desc);
1046         body->lock_flags = flags;
1047
1048         ldlm_lock2handle(lock, &body->lock_handle1);
1049         size[0] = sizeof(*reply);
1050         if (lock->l_lvb_len != 0) {
1051                 buffers = 2;
1052                 size[1] = lock->l_lvb_len;
1053         }
1054         req->rq_replen = lustre_msg_size(buffers, size);
1055         /* notify the server we've replayed all requests.
1056          * also, we mark the request to be put on a dedicated
1057          * queue to be processed after all request replayes.
1058          * bug 6063 */
1059         lustre_msg_set_flags(req->rq_reqmsg, MSG_REQ_REPLAY_DONE);
1060
1061         LDLM_DEBUG(lock, "replaying lock:");
1062
1063         imp->imp_locks_replayed++;
1064         atomic_inc(&req->rq_import->imp_replay_inflight);
1065         req->rq_async_args.pointer_arg[0] = lock;
1066         req->rq_interpret_reply = replay_lock_interpret;
1067         ptlrpcd_add_req(req);
1068
1069         RETURN(0);
1070 }
1071
1072 int ldlm_replay_locks(struct obd_import *imp)
1073 {
1074         struct ldlm_namespace *ns = imp->imp_obd->obd_namespace;
1075         struct list_head list, *pos, *next;
1076         struct ldlm_lock *lock;
1077         int rc = 0;
1078
1079         ENTRY;
1080         INIT_LIST_HEAD(&list);
1081
1082         LASSERT(atomic_read(&imp->imp_replay_inflight) == 0);
1083         LASSERT(ns != NULL);
1084
1085         /* ensure this doesn't fall to 0 before all have been queued */
1086         atomic_inc(&imp->imp_replay_inflight);
1087
1088         (void)ldlm_namespace_foreach(ns, ldlm_chain_lock_for_replay, &list);
1089
1090         list_for_each_safe(pos, next, &list) {
1091                 lock = list_entry(pos, struct ldlm_lock, l_pending_chain);
1092                 rc = replay_one_lock(imp, lock);
1093                 if (rc)
1094                         break; /* or try to do the rest? */
1095         }
1096
1097         atomic_dec(&imp->imp_replay_inflight);
1098
1099         RETURN(rc);
1100 }