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[linux-2.6] / fs / ocfs2 / dlm / dlmconvert.c
1 /* -*- mode: c; c-basic-offset: 8; -*-
2  * vim: noexpandtab sw=8 ts=8 sts=0:
3  *
4  * dlmconvert.c
5  *
6  * underlying calls for lock conversion
7  *
8  * Copyright (C) 2004 Oracle.  All rights reserved.
9  *
10  * This program is free software; you can redistribute it and/or
11  * modify it under the terms of the GNU General Public
12  * License as published by the Free Software Foundation; either
13  * version 2 of the License, or (at your option) any later version.
14  *
15  * This program is distributed in the hope that it will be useful,
16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
18  * General Public License for more details.
19  *
20  * You should have received a copy of the GNU General Public
21  * License along with this program; if not, write to the
22  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
23  * Boston, MA 021110-1307, USA.
24  *
25  */
26
27
28 #include <linux/module.h>
29 #include <linux/fs.h>
30 #include <linux/types.h>
31 #include <linux/slab.h>
32 #include <linux/highmem.h>
33 #include <linux/utsname.h>
34 #include <linux/init.h>
35 #include <linux/sysctl.h>
36 #include <linux/random.h>
37 #include <linux/blkdev.h>
38 #include <linux/socket.h>
39 #include <linux/inet.h>
40 #include <linux/spinlock.h>
41
42
43 #include "cluster/heartbeat.h"
44 #include "cluster/nodemanager.h"
45 #include "cluster/tcp.h"
46
47 #include "dlmapi.h"
48 #include "dlmcommon.h"
49
50 #include "dlmconvert.h"
51
52 #define MLOG_MASK_PREFIX ML_DLM
53 #include "cluster/masklog.h"
54
55 /* NOTE: __dlmconvert_master is the only function in here that
56  * needs a spinlock held on entry (res->spinlock) and it is the
57  * only one that holds a lock on exit (res->spinlock).
58  * All other functions in here need no locks and drop all of
59  * the locks that they acquire. */
60 static enum dlm_status __dlmconvert_master(struct dlm_ctxt *dlm,
61                                            struct dlm_lock_resource *res,
62                                            struct dlm_lock *lock, int flags,
63                                            int type, int *call_ast,
64                                            int *kick_thread);
65 static enum dlm_status dlm_send_remote_convert_request(struct dlm_ctxt *dlm,
66                                            struct dlm_lock_resource *res,
67                                            struct dlm_lock *lock, int flags, int type);
68
69 /*
70  * this is only called directly by dlmlock(), and only when the
71  * local node is the owner of the lockres
72  * locking:
73  *   caller needs:  none
74  *   taken:         takes and drops res->spinlock
75  *   held on exit:  none
76  * returns: see __dlmconvert_master
77  */
78 enum dlm_status dlmconvert_master(struct dlm_ctxt *dlm,
79                                   struct dlm_lock_resource *res,
80                                   struct dlm_lock *lock, int flags, int type)
81 {
82         int call_ast = 0, kick_thread = 0;
83         enum dlm_status status;
84
85         spin_lock(&res->spinlock);
86         /* we are not in a network handler, this is fine */
87         __dlm_wait_on_lockres(res);
88         __dlm_lockres_reserve_ast(res);
89         res->state |= DLM_LOCK_RES_IN_PROGRESS;
90
91         status = __dlmconvert_master(dlm, res, lock, flags, type,
92                                      &call_ast, &kick_thread);
93
94         res->state &= ~DLM_LOCK_RES_IN_PROGRESS;
95         spin_unlock(&res->spinlock);
96         wake_up(&res->wq);
97         if (status != DLM_NORMAL && status != DLM_NOTQUEUED)
98                 dlm_error(status);
99
100         /* either queue the ast or release it */
101         if (call_ast)
102                 dlm_queue_ast(dlm, lock);
103         else
104                 dlm_lockres_release_ast(dlm, res);
105
106         if (kick_thread)
107                 dlm_kick_thread(dlm, res);
108
109         return status;
110 }
111
112 /* performs lock conversion at the lockres master site
113  * locking:
114  *   caller needs:  res->spinlock
115  *   taken:         takes and drops lock->spinlock
116  *   held on exit:  res->spinlock
117  * returns: DLM_NORMAL, DLM_NOTQUEUED, DLM_DENIED
118  *   call_ast: whether ast should be called for this lock
119  *   kick_thread: whether dlm_kick_thread should be called
120  */
121 static enum dlm_status __dlmconvert_master(struct dlm_ctxt *dlm,
122                                            struct dlm_lock_resource *res,
123                                            struct dlm_lock *lock, int flags,
124                                            int type, int *call_ast,
125                                            int *kick_thread)
126 {
127         enum dlm_status status = DLM_NORMAL;
128         struct list_head *iter;
129         struct dlm_lock *tmplock=NULL;
130
131         assert_spin_locked(&res->spinlock);
132
133         mlog_entry("type=%d, convert_type=%d, new convert_type=%d\n",
134                    lock->ml.type, lock->ml.convert_type, type);
135
136         spin_lock(&lock->spinlock);
137
138         /* already converting? */
139         if (lock->ml.convert_type != LKM_IVMODE) {
140                 mlog(ML_ERROR, "attempted to convert a lock with a lock "
141                      "conversion pending\n");
142                 status = DLM_DENIED;
143                 goto unlock_exit;
144         }
145
146         /* must be on grant queue to convert */
147         if (!dlm_lock_on_list(&res->granted, lock)) {
148                 mlog(ML_ERROR, "attempted to convert a lock not on grant "
149                      "queue\n");
150                 status = DLM_DENIED;
151                 goto unlock_exit;
152         }
153
154         if (flags & LKM_VALBLK) {
155                 switch (lock->ml.type) {
156                         case LKM_EXMODE:
157                                 /* EX + LKM_VALBLK + convert == set lvb */
158                                 mlog(0, "will set lvb: converting %s->%s\n",
159                                      dlm_lock_mode_name(lock->ml.type),
160                                      dlm_lock_mode_name(type));
161                                 lock->lksb->flags |= DLM_LKSB_PUT_LVB;
162                                 break;
163                         case LKM_PRMODE:
164                         case LKM_NLMODE:
165                                 /* refetch if new level is not NL */
166                                 if (type > LKM_NLMODE) {
167                                         mlog(0, "will fetch new value into "
168                                              "lvb: converting %s->%s\n",
169                                              dlm_lock_mode_name(lock->ml.type),
170                                              dlm_lock_mode_name(type));
171                                         lock->lksb->flags |= DLM_LKSB_GET_LVB;
172                                 } else {
173                                         mlog(0, "will NOT fetch new value "
174                                              "into lvb: converting %s->%s\n",
175                                              dlm_lock_mode_name(lock->ml.type),
176                                              dlm_lock_mode_name(type));
177                                         flags &= ~(LKM_VALBLK);
178                                 }
179                                 break;
180                 }
181         }
182
183
184         /* in-place downconvert? */
185         if (type <= lock->ml.type)
186                 goto grant;
187
188         /* upconvert from here on */
189         status = DLM_NORMAL;
190         list_for_each(iter, &res->granted) {
191                 tmplock = list_entry(iter, struct dlm_lock, list);
192                 if (tmplock == lock)
193                         continue;
194                 if (!dlm_lock_compatible(tmplock->ml.type, type))
195                         goto switch_queues;
196         }
197
198         list_for_each(iter, &res->converting) {
199                 tmplock = list_entry(iter, struct dlm_lock, list);
200                 if (!dlm_lock_compatible(tmplock->ml.type, type))
201                         goto switch_queues;
202                 /* existing conversion requests take precedence */
203                 if (!dlm_lock_compatible(tmplock->ml.convert_type, type))
204                         goto switch_queues;
205         }
206
207         /* fall thru to grant */
208
209 grant:
210         mlog(0, "res %.*s, granting %s lock\n", res->lockname.len,
211              res->lockname.name, dlm_lock_mode_name(type));
212         /* immediately grant the new lock type */
213         lock->lksb->status = DLM_NORMAL;
214         if (lock->ml.node == dlm->node_num)
215                 mlog(0, "doing in-place convert for nonlocal lock\n");
216         lock->ml.type = type;
217         if (lock->lksb->flags & DLM_LKSB_PUT_LVB)
218                 memcpy(res->lvb, lock->lksb->lvb, DLM_LVB_LEN);
219
220         status = DLM_NORMAL;
221         *call_ast = 1;
222         goto unlock_exit;
223
224 switch_queues:
225         if (flags & LKM_NOQUEUE) {
226                 mlog(0, "failed to convert NOQUEUE lock %.*s from "
227                      "%d to %d...\n", res->lockname.len, res->lockname.name,
228                      lock->ml.type, type);
229                 status = DLM_NOTQUEUED;
230                 goto unlock_exit;
231         }
232         mlog(0, "res %.*s, queueing...\n", res->lockname.len,
233              res->lockname.name);
234
235         lock->ml.convert_type = type;
236         /* do not alter lock refcount.  switching lists. */
237         list_move_tail(&lock->list, &res->converting);
238
239 unlock_exit:
240         spin_unlock(&lock->spinlock);
241         if (status == DLM_DENIED) {
242                 __dlm_print_one_lock_resource(res);
243         }
244         if (status == DLM_NORMAL)
245                 *kick_thread = 1;
246         return status;
247 }
248
249 void dlm_revert_pending_convert(struct dlm_lock_resource *res,
250                                 struct dlm_lock *lock)
251 {
252         /* do not alter lock refcount.  switching lists. */
253         list_move_tail(&lock->list, &res->granted);
254         lock->ml.convert_type = LKM_IVMODE;
255         lock->lksb->flags &= ~(DLM_LKSB_GET_LVB|DLM_LKSB_PUT_LVB);
256 }
257
258 /* messages the master site to do lock conversion
259  * locking:
260  *   caller needs:  none
261  *   taken:         takes and drops res->spinlock, uses DLM_LOCK_RES_IN_PROGRESS
262  *   held on exit:  none
263  * returns: DLM_NORMAL, DLM_RECOVERING, status from remote node
264  */
265 enum dlm_status dlmconvert_remote(struct dlm_ctxt *dlm,
266                                   struct dlm_lock_resource *res,
267                                   struct dlm_lock *lock, int flags, int type)
268 {
269         enum dlm_status status;
270
271         mlog(0, "type=%d, convert_type=%d, busy=%d\n", lock->ml.type,
272              lock->ml.convert_type, res->state & DLM_LOCK_RES_IN_PROGRESS);
273
274         spin_lock(&res->spinlock);
275         if (res->state & DLM_LOCK_RES_RECOVERING) {
276                 mlog(0, "bailing out early since res is RECOVERING "
277                      "on secondary queue\n");
278                 /* __dlm_print_one_lock_resource(res); */
279                 status = DLM_RECOVERING;
280                 goto bail;
281         }
282         /* will exit this call with spinlock held */
283         __dlm_wait_on_lockres(res);
284
285         if (lock->ml.convert_type != LKM_IVMODE) {
286                 __dlm_print_one_lock_resource(res);
287                 mlog(ML_ERROR, "converting a remote lock that is already "
288                      "converting! (cookie=%u:%llu, conv=%d)\n",
289                      dlm_get_lock_cookie_node(be64_to_cpu(lock->ml.cookie)),
290                      dlm_get_lock_cookie_seq(be64_to_cpu(lock->ml.cookie)),
291                      lock->ml.convert_type);
292                 status = DLM_DENIED;
293                 goto bail;
294         }
295         res->state |= DLM_LOCK_RES_IN_PROGRESS;
296         /* move lock to local convert queue */
297         /* do not alter lock refcount.  switching lists. */
298         list_move_tail(&lock->list, &res->converting);
299         lock->convert_pending = 1;
300         lock->ml.convert_type = type;
301
302         if (flags & LKM_VALBLK) {
303                 if (lock->ml.type == LKM_EXMODE) {
304                         flags |= LKM_PUT_LVB;
305                         lock->lksb->flags |= DLM_LKSB_PUT_LVB;
306                 } else {
307                         if (lock->ml.convert_type == LKM_NLMODE)
308                                 flags &= ~LKM_VALBLK;
309                         else {
310                                 flags |= LKM_GET_LVB;
311                                 lock->lksb->flags |= DLM_LKSB_GET_LVB;
312                         }
313                 }
314         }
315         spin_unlock(&res->spinlock);
316
317         /* no locks held here.
318          * need to wait for a reply as to whether it got queued or not. */
319         status = dlm_send_remote_convert_request(dlm, res, lock, flags, type);
320
321         spin_lock(&res->spinlock);
322         res->state &= ~DLM_LOCK_RES_IN_PROGRESS;
323         lock->convert_pending = 0;
324         /* if it failed, move it back to granted queue */
325         if (status != DLM_NORMAL) {
326                 if (status != DLM_NOTQUEUED)
327                         dlm_error(status);
328                 dlm_revert_pending_convert(res, lock);
329         }
330 bail:
331         spin_unlock(&res->spinlock);
332
333         /* TODO: should this be a wake_one? */
334         /* wake up any IN_PROGRESS waiters */
335         wake_up(&res->wq);
336
337         return status;
338 }
339
340 /* sends DLM_CONVERT_LOCK_MSG to master site
341  * locking:
342  *   caller needs:  none
343  *   taken:         none
344  *   held on exit:  none
345  * returns: DLM_NOLOCKMGR, status from remote node
346  */
347 static enum dlm_status dlm_send_remote_convert_request(struct dlm_ctxt *dlm,
348                                            struct dlm_lock_resource *res,
349                                            struct dlm_lock *lock, int flags, int type)
350 {
351         struct dlm_convert_lock convert;
352         int tmpret;
353         enum dlm_status ret;
354         int status = 0;
355         struct kvec vec[2];
356         size_t veclen = 1;
357
358         mlog_entry("%.*s\n", res->lockname.len, res->lockname.name);
359
360         memset(&convert, 0, sizeof(struct dlm_convert_lock));
361         convert.node_idx = dlm->node_num;
362         convert.requested_type = type;
363         convert.cookie = lock->ml.cookie;
364         convert.namelen = res->lockname.len;
365         convert.flags = cpu_to_be32(flags);
366         memcpy(convert.name, res->lockname.name, convert.namelen);
367
368         vec[0].iov_len = sizeof(struct dlm_convert_lock);
369         vec[0].iov_base = &convert;
370
371         if (flags & LKM_PUT_LVB) {
372                 /* extra data to send if we are updating lvb */
373                 vec[1].iov_len = DLM_LVB_LEN;
374                 vec[1].iov_base = lock->lksb->lvb;
375                 veclen++;
376         }
377
378         tmpret = o2net_send_message_vec(DLM_CONVERT_LOCK_MSG, dlm->key,
379                                         vec, veclen, res->owner, &status);
380         if (tmpret >= 0) {
381                 // successfully sent and received
382                 ret = status;  // this is already a dlm_status
383                 if (ret == DLM_RECOVERING) {
384                         mlog(0, "node %u returned DLM_RECOVERING from convert "
385                              "message!\n", res->owner);
386                 } else if (ret == DLM_MIGRATING) {
387                         mlog(0, "node %u returned DLM_MIGRATING from convert "
388                              "message!\n", res->owner);
389                 } else if (ret == DLM_FORWARD) {
390                         mlog(0, "node %u returned DLM_FORWARD from convert "
391                              "message!\n", res->owner);
392                 } else if (ret != DLM_NORMAL && ret != DLM_NOTQUEUED)
393                         dlm_error(ret);
394         } else {
395                 mlog_errno(tmpret);
396                 if (dlm_is_host_down(tmpret)) {
397                         /* instead of logging the same network error over
398                          * and over, sleep here and wait for the heartbeat
399                          * to notice the node is dead.  times out after 5s. */
400                         dlm_wait_for_node_death(dlm, res->owner, 
401                                                 DLM_NODE_DEATH_WAIT_MAX);
402                         ret = DLM_RECOVERING;
403                         mlog(0, "node %u died so returning DLM_RECOVERING "
404                              "from convert message!\n", res->owner);
405                 } else {
406                         ret = dlm_err_to_dlm_status(tmpret);
407                 }
408         }
409
410         return ret;
411 }
412
413 /* handler for DLM_CONVERT_LOCK_MSG on master site
414  * locking:
415  *   caller needs:  none
416  *   taken:         takes and drop res->spinlock
417  *   held on exit:  none
418  * returns: DLM_NORMAL, DLM_IVLOCKID, DLM_BADARGS,
419  *          status from __dlmconvert_master
420  */
421 int dlm_convert_lock_handler(struct o2net_msg *msg, u32 len, void *data,
422                              void **ret_data)
423 {
424         struct dlm_ctxt *dlm = data;
425         struct dlm_convert_lock *cnv = (struct dlm_convert_lock *)msg->buf;
426         struct dlm_lock_resource *res = NULL;
427         struct list_head *iter;
428         struct dlm_lock *lock = NULL;
429         struct dlm_lockstatus *lksb;
430         enum dlm_status status = DLM_NORMAL;
431         u32 flags;
432         int call_ast = 0, kick_thread = 0, ast_reserved = 0, wake = 0;
433
434         if (!dlm_grab(dlm)) {
435                 dlm_error(DLM_REJECTED);
436                 return DLM_REJECTED;
437         }
438
439         mlog_bug_on_msg(!dlm_domain_fully_joined(dlm),
440                         "Domain %s not fully joined!\n", dlm->name);
441
442         if (cnv->namelen > DLM_LOCKID_NAME_MAX) {
443                 status = DLM_IVBUFLEN;
444                 dlm_error(status);
445                 goto leave;
446         }
447
448         flags = be32_to_cpu(cnv->flags);
449
450         if ((flags & (LKM_PUT_LVB|LKM_GET_LVB)) ==
451              (LKM_PUT_LVB|LKM_GET_LVB)) {
452                 mlog(ML_ERROR, "both PUT and GET lvb specified\n");
453                 status = DLM_BADARGS;
454                 goto leave;
455         }
456
457         mlog(0, "lvb: %s\n", flags & LKM_PUT_LVB ? "put lvb" :
458              (flags & LKM_GET_LVB ? "get lvb" : "none"));
459
460         status = DLM_IVLOCKID;
461         res = dlm_lookup_lockres(dlm, cnv->name, cnv->namelen);
462         if (!res) {
463                 dlm_error(status);
464                 goto leave;
465         }
466
467         spin_lock(&res->spinlock);
468         status = __dlm_lockres_state_to_status(res);
469         if (status != DLM_NORMAL) {
470                 spin_unlock(&res->spinlock);
471                 dlm_error(status);
472                 goto leave;
473         }
474         list_for_each(iter, &res->granted) {
475                 lock = list_entry(iter, struct dlm_lock, list);
476                 if (lock->ml.cookie == cnv->cookie &&
477                     lock->ml.node == cnv->node_idx) {
478                         dlm_lock_get(lock);
479                         break;
480                 }
481                 lock = NULL;
482         }
483         spin_unlock(&res->spinlock);
484         if (!lock) {
485                 status = DLM_IVLOCKID;
486                 mlog(ML_ERROR, "did not find lock to convert on grant queue! "
487                                "cookie=%u:%llu\n",
488                      dlm_get_lock_cookie_node(be64_to_cpu(cnv->cookie)),
489                      dlm_get_lock_cookie_seq(be64_to_cpu(cnv->cookie)));
490                 dlm_print_one_lock_resource(res);
491                 goto leave;
492         }
493
494         /* found the lock */
495         lksb = lock->lksb;
496
497         /* see if caller needed to get/put lvb */
498         if (flags & LKM_PUT_LVB) {
499                 BUG_ON(lksb->flags & (DLM_LKSB_PUT_LVB|DLM_LKSB_GET_LVB));
500                 lksb->flags |= DLM_LKSB_PUT_LVB;
501                 memcpy(&lksb->lvb[0], &cnv->lvb[0], DLM_LVB_LEN);
502         } else if (flags & LKM_GET_LVB) {
503                 BUG_ON(lksb->flags & (DLM_LKSB_PUT_LVB|DLM_LKSB_GET_LVB));
504                 lksb->flags |= DLM_LKSB_GET_LVB;
505         }
506
507         spin_lock(&res->spinlock);
508         status = __dlm_lockres_state_to_status(res);
509         if (status == DLM_NORMAL) {
510                 __dlm_lockres_reserve_ast(res);
511                 ast_reserved = 1;
512                 res->state |= DLM_LOCK_RES_IN_PROGRESS;
513                 status = __dlmconvert_master(dlm, res, lock, flags,
514                                              cnv->requested_type,
515                                              &call_ast, &kick_thread);
516                 res->state &= ~DLM_LOCK_RES_IN_PROGRESS;
517                 wake = 1;
518         }
519         spin_unlock(&res->spinlock);
520         if (wake)
521                 wake_up(&res->wq);
522
523         if (status != DLM_NORMAL) {
524                 if (status != DLM_NOTQUEUED)
525                         dlm_error(status);
526                 lksb->flags &= ~(DLM_LKSB_GET_LVB|DLM_LKSB_PUT_LVB);
527         }
528
529 leave:
530         if (lock)
531                 dlm_lock_put(lock);
532
533         /* either queue the ast or release it, if reserved */
534         if (call_ast)
535                 dlm_queue_ast(dlm, lock);
536         else if (ast_reserved)
537                 dlm_lockres_release_ast(dlm, res);
538
539         if (kick_thread)
540                 dlm_kick_thread(dlm, res);
541
542         if (res)
543                 dlm_lockres_put(res);
544
545         dlm_put(dlm);
546
547         return status;
548 }