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