• Home
  • History
  • Annotate
  • Line#
  • Navigate
  • Raw
  • Download
  • only in /asuswrt-rt-n18u-9.0.0.4.380.2695/release/src-rt-6.x.4708/linux/linux-2.6.36/fs/ocfs2/dlm/
1/* -*- mode: c; c-basic-offset: 8; -*-
2 * vim: noexpandtab sw=8 ts=8 sts=0:
3 *
4 * dlmlock.c
5 *
6 * underlying calls for lock creation
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/init.h>
34#include <linux/sysctl.h>
35#include <linux/random.h>
36#include <linux/blkdev.h>
37#include <linux/socket.h>
38#include <linux/inet.h>
39#include <linux/spinlock.h>
40#include <linux/delay.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
55static struct kmem_cache *dlm_lock_cache = NULL;
56
57static DEFINE_SPINLOCK(dlm_cookie_lock);
58static u64 dlm_next_cookie = 1;
59
60static enum dlm_status dlm_send_remote_lock_request(struct dlm_ctxt *dlm,
61					       struct dlm_lock_resource *res,
62					       struct dlm_lock *lock, int flags);
63static void dlm_init_lock(struct dlm_lock *newlock, int type,
64			  u8 node, u64 cookie);
65static void dlm_lock_release(struct kref *kref);
66static void dlm_lock_detach_lockres(struct dlm_lock *lock);
67
68int dlm_init_lock_cache(void)
69{
70	dlm_lock_cache = kmem_cache_create("o2dlm_lock",
71					   sizeof(struct dlm_lock),
72					   0, SLAB_HWCACHE_ALIGN, NULL);
73	if (dlm_lock_cache == NULL)
74		return -ENOMEM;
75	return 0;
76}
77
78void dlm_destroy_lock_cache(void)
79{
80	if (dlm_lock_cache)
81		kmem_cache_destroy(dlm_lock_cache);
82}
83
84/* Tell us whether we can grant a new lock request.
85 * locking:
86 *   caller needs:  res->spinlock
87 *   taken:         none
88 *   held on exit:  none
89 * returns: 1 if the lock can be granted, 0 otherwise.
90 */
91static int dlm_can_grant_new_lock(struct dlm_lock_resource *res,
92				  struct dlm_lock *lock)
93{
94	struct list_head *iter;
95	struct dlm_lock *tmplock;
96
97	list_for_each(iter, &res->granted) {
98		tmplock = list_entry(iter, struct dlm_lock, list);
99
100		if (!dlm_lock_compatible(tmplock->ml.type, lock->ml.type))
101			return 0;
102	}
103
104	list_for_each(iter, &res->converting) {
105		tmplock = list_entry(iter, struct dlm_lock, list);
106
107		if (!dlm_lock_compatible(tmplock->ml.type, lock->ml.type))
108			return 0;
109	}
110
111	return 1;
112}
113
114/* performs lock creation at the lockres master site
115 * locking:
116 *   caller needs:  none
117 *   taken:         takes and drops res->spinlock
118 *   held on exit:  none
119 * returns: DLM_NORMAL, DLM_NOTQUEUED
120 */
121static enum dlm_status dlmlock_master(struct dlm_ctxt *dlm,
122				      struct dlm_lock_resource *res,
123				      struct dlm_lock *lock, int flags)
124{
125	int call_ast = 0, kick_thread = 0;
126	enum dlm_status status = DLM_NORMAL;
127
128	mlog_entry("type=%d\n", lock->ml.type);
129
130	spin_lock(&res->spinlock);
131	/* if called from dlm_create_lock_handler, need to
132	 * ensure it will not sleep in dlm_wait_on_lockres */
133	status = __dlm_lockres_state_to_status(res);
134	if (status != DLM_NORMAL &&
135	    lock->ml.node != dlm->node_num) {
136		/* erf.  state changed after lock was dropped. */
137		spin_unlock(&res->spinlock);
138		dlm_error(status);
139		return status;
140	}
141	__dlm_wait_on_lockres(res);
142	__dlm_lockres_reserve_ast(res);
143
144	if (dlm_can_grant_new_lock(res, lock)) {
145		mlog(0, "I can grant this lock right away\n");
146		/* got it right away */
147		lock->lksb->status = DLM_NORMAL;
148		status = DLM_NORMAL;
149		dlm_lock_get(lock);
150		list_add_tail(&lock->list, &res->granted);
151
152		/* for the recovery lock, we can't allow the ast
153		 * to be queued since the dlmthread is already
154		 * frozen.  but the recovery lock is always locked
155		 * with LKM_NOQUEUE so we do not need the ast in
156		 * this special case */
157		if (!dlm_is_recovery_lock(res->lockname.name,
158					  res->lockname.len)) {
159			kick_thread = 1;
160			call_ast = 1;
161		} else {
162			mlog(0, "%s: returning DLM_NORMAL to "
163			     "node %u for reco lock\n", dlm->name,
164			     lock->ml.node);
165		}
166	} else {
167		/* for NOQUEUE request, unless we get the
168		 * lock right away, return DLM_NOTQUEUED */
169		if (flags & LKM_NOQUEUE) {
170			status = DLM_NOTQUEUED;
171			if (dlm_is_recovery_lock(res->lockname.name,
172						 res->lockname.len)) {
173				mlog(0, "%s: returning NOTQUEUED to "
174				     "node %u for reco lock\n", dlm->name,
175				     lock->ml.node);
176			}
177		} else {
178			dlm_lock_get(lock);
179			list_add_tail(&lock->list, &res->blocked);
180			kick_thread = 1;
181		}
182	}
183	/* reduce the inflight count, this may result in the lockres
184	 * being purged below during calc_usage */
185	if (lock->ml.node == dlm->node_num)
186		dlm_lockres_drop_inflight_ref(dlm, res);
187
188	spin_unlock(&res->spinlock);
189	wake_up(&res->wq);
190
191	/* either queue the ast or release it */
192	if (call_ast)
193		dlm_queue_ast(dlm, lock);
194	else
195		dlm_lockres_release_ast(dlm, res);
196
197	dlm_lockres_calc_usage(dlm, res);
198	if (kick_thread)
199		dlm_kick_thread(dlm, res);
200
201	return status;
202}
203
204void dlm_revert_pending_lock(struct dlm_lock_resource *res,
205			     struct dlm_lock *lock)
206{
207	/* remove from local queue if it failed */
208	list_del_init(&lock->list);
209	lock->lksb->flags &= ~DLM_LKSB_GET_LVB;
210}
211
212
213/*
214 * locking:
215 *   caller needs:  none
216 *   taken:         takes and drops res->spinlock
217 *   held on exit:  none
218 * returns: DLM_DENIED, DLM_RECOVERING, or net status
219 */
220static enum dlm_status dlmlock_remote(struct dlm_ctxt *dlm,
221				      struct dlm_lock_resource *res,
222				      struct dlm_lock *lock, int flags)
223{
224	enum dlm_status status = DLM_DENIED;
225	int lockres_changed = 1;
226
227	mlog_entry("type=%d\n", lock->ml.type);
228	mlog(0, "lockres %.*s, flags = 0x%x\n", res->lockname.len,
229	     res->lockname.name, flags);
230
231	spin_lock(&res->spinlock);
232
233	/* will exit this call with spinlock held */
234	__dlm_wait_on_lockres(res);
235	res->state |= DLM_LOCK_RES_IN_PROGRESS;
236
237	/* add lock to local (secondary) queue */
238	dlm_lock_get(lock);
239	list_add_tail(&lock->list, &res->blocked);
240	lock->lock_pending = 1;
241	spin_unlock(&res->spinlock);
242
243	/* spec seems to say that you will get DLM_NORMAL when the lock
244	 * has been queued, meaning we need to wait for a reply here. */
245	status = dlm_send_remote_lock_request(dlm, res, lock, flags);
246
247	spin_lock(&res->spinlock);
248	res->state &= ~DLM_LOCK_RES_IN_PROGRESS;
249	lock->lock_pending = 0;
250	if (status != DLM_NORMAL) {
251		if (status == DLM_RECOVERING &&
252		    dlm_is_recovery_lock(res->lockname.name,
253					 res->lockname.len)) {
254			/* recovery lock was mastered by dead node.
255			 * we need to have calc_usage shoot down this
256			 * lockres and completely remaster it. */
257			mlog(0, "%s: recovery lock was owned by "
258			     "dead node %u, remaster it now.\n",
259			     dlm->name, res->owner);
260		} else if (status != DLM_NOTQUEUED) {
261			/*
262			 * DO NOT call calc_usage, as this would unhash
263			 * the remote lockres before we ever get to use
264			 * it.  treat as if we never made any change to
265			 * the lockres.
266			 */
267			lockres_changed = 0;
268			dlm_error(status);
269		}
270		dlm_revert_pending_lock(res, lock);
271		dlm_lock_put(lock);
272	} else if (dlm_is_recovery_lock(res->lockname.name,
273					res->lockname.len)) {
274		/* special case for the $RECOVERY lock.
275		 * there will never be an AST delivered to put
276		 * this lock on the proper secondary queue
277		 * (granted), so do it manually. */
278		mlog(0, "%s: $RECOVERY lock for this node (%u) is "
279		     "mastered by %u; got lock, manually granting (no ast)\n",
280		     dlm->name, dlm->node_num, res->owner);
281		list_move_tail(&lock->list, &res->granted);
282	}
283	spin_unlock(&res->spinlock);
284
285	if (lockres_changed)
286		dlm_lockres_calc_usage(dlm, res);
287
288	wake_up(&res->wq);
289	return status;
290}
291
292
293/* for remote lock creation.
294 * locking:
295 *   caller needs:  none, but need res->state & DLM_LOCK_RES_IN_PROGRESS
296 *   taken:         none
297 *   held on exit:  none
298 * returns: DLM_NOLOCKMGR, or net status
299 */
300static enum dlm_status dlm_send_remote_lock_request(struct dlm_ctxt *dlm,
301					       struct dlm_lock_resource *res,
302					       struct dlm_lock *lock, int flags)
303{
304	struct dlm_create_lock create;
305	int tmpret, status = 0;
306	enum dlm_status ret;
307
308	mlog_entry_void();
309
310	memset(&create, 0, sizeof(create));
311	create.node_idx = dlm->node_num;
312	create.requested_type = lock->ml.type;
313	create.cookie = lock->ml.cookie;
314	create.namelen = res->lockname.len;
315	create.flags = cpu_to_be32(flags);
316	memcpy(create.name, res->lockname.name, create.namelen);
317
318	tmpret = o2net_send_message(DLM_CREATE_LOCK_MSG, dlm->key, &create,
319				    sizeof(create), res->owner, &status);
320	if (tmpret >= 0) {
321		// successfully sent and received
322		ret = status;  // this is already a dlm_status
323		if (ret == DLM_REJECTED) {
324			mlog(ML_ERROR, "%s:%.*s: BUG.  this is a stale lockres "
325			     "no longer owned by %u.  that node is coming back "
326			     "up currently.\n", dlm->name, create.namelen,
327			     create.name, res->owner);
328			dlm_print_one_lock_resource(res);
329			BUG();
330		}
331	} else {
332		mlog(ML_ERROR, "Error %d when sending message %u (key 0x%x) to "
333		     "node %u\n", tmpret, DLM_CREATE_LOCK_MSG, dlm->key,
334		     res->owner);
335		if (dlm_is_host_down(tmpret)) {
336			ret = DLM_RECOVERING;
337			mlog(0, "node %u died so returning DLM_RECOVERING "
338			     "from lock message!\n", res->owner);
339		} else {
340			ret = dlm_err_to_dlm_status(tmpret);
341		}
342	}
343
344	return ret;
345}
346
347void dlm_lock_get(struct dlm_lock *lock)
348{
349	kref_get(&lock->lock_refs);
350}
351
352void dlm_lock_put(struct dlm_lock *lock)
353{
354	kref_put(&lock->lock_refs, dlm_lock_release);
355}
356
357static void dlm_lock_release(struct kref *kref)
358{
359	struct dlm_lock *lock;
360
361	lock = container_of(kref, struct dlm_lock, lock_refs);
362
363	BUG_ON(!list_empty(&lock->list));
364	BUG_ON(!list_empty(&lock->ast_list));
365	BUG_ON(!list_empty(&lock->bast_list));
366	BUG_ON(lock->ast_pending);
367	BUG_ON(lock->bast_pending);
368
369	dlm_lock_detach_lockres(lock);
370
371	if (lock->lksb_kernel_allocated) {
372		mlog(0, "freeing kernel-allocated lksb\n");
373		kfree(lock->lksb);
374	}
375	kmem_cache_free(dlm_lock_cache, lock);
376}
377
378/* associate a lock with it's lockres, getting a ref on the lockres */
379void dlm_lock_attach_lockres(struct dlm_lock *lock,
380			     struct dlm_lock_resource *res)
381{
382	dlm_lockres_get(res);
383	lock->lockres = res;
384}
385
386/* drop ref on lockres, if there is still one associated with lock */
387static void dlm_lock_detach_lockres(struct dlm_lock *lock)
388{
389	struct dlm_lock_resource *res;
390
391	res = lock->lockres;
392	if (res) {
393		lock->lockres = NULL;
394		mlog(0, "removing lock's lockres reference\n");
395		dlm_lockres_put(res);
396	}
397}
398
399static void dlm_init_lock(struct dlm_lock *newlock, int type,
400			  u8 node, u64 cookie)
401{
402	INIT_LIST_HEAD(&newlock->list);
403	INIT_LIST_HEAD(&newlock->ast_list);
404	INIT_LIST_HEAD(&newlock->bast_list);
405	spin_lock_init(&newlock->spinlock);
406	newlock->ml.type = type;
407	newlock->ml.convert_type = LKM_IVMODE;
408	newlock->ml.highest_blocked = LKM_IVMODE;
409	newlock->ml.node = node;
410	newlock->ml.pad1 = 0;
411	newlock->ml.list = 0;
412	newlock->ml.flags = 0;
413	newlock->ast = NULL;
414	newlock->bast = NULL;
415	newlock->astdata = NULL;
416	newlock->ml.cookie = cpu_to_be64(cookie);
417	newlock->ast_pending = 0;
418	newlock->bast_pending = 0;
419	newlock->convert_pending = 0;
420	newlock->lock_pending = 0;
421	newlock->unlock_pending = 0;
422	newlock->cancel_pending = 0;
423	newlock->lksb_kernel_allocated = 0;
424
425	kref_init(&newlock->lock_refs);
426}
427
428struct dlm_lock * dlm_new_lock(int type, u8 node, u64 cookie,
429			       struct dlm_lockstatus *lksb)
430{
431	struct dlm_lock *lock;
432	int kernel_allocated = 0;
433
434	lock = kmem_cache_zalloc(dlm_lock_cache, GFP_NOFS);
435	if (!lock)
436		return NULL;
437
438	if (!lksb) {
439		/* zero memory only if kernel-allocated */
440		lksb = kzalloc(sizeof(*lksb), GFP_NOFS);
441		if (!lksb) {
442			kfree(lock);
443			return NULL;
444		}
445		kernel_allocated = 1;
446	}
447
448	dlm_init_lock(lock, type, node, cookie);
449	if (kernel_allocated)
450		lock->lksb_kernel_allocated = 1;
451	lock->lksb = lksb;
452	lksb->lockid = lock;
453	return lock;
454}
455
456/* handler for lock creation net message
457 * locking:
458 *   caller needs:  none
459 *   taken:         takes and drops res->spinlock
460 *   held on exit:  none
461 * returns: DLM_NORMAL, DLM_SYSERR, DLM_IVLOCKID, DLM_NOTQUEUED
462 */
463int dlm_create_lock_handler(struct o2net_msg *msg, u32 len, void *data,
464			    void **ret_data)
465{
466	struct dlm_ctxt *dlm = data;
467	struct dlm_create_lock *create = (struct dlm_create_lock *)msg->buf;
468	struct dlm_lock_resource *res = NULL;
469	struct dlm_lock *newlock = NULL;
470	struct dlm_lockstatus *lksb = NULL;
471	enum dlm_status status = DLM_NORMAL;
472	char *name;
473	unsigned int namelen;
474
475	BUG_ON(!dlm);
476
477	mlog_entry_void();
478
479	if (!dlm_grab(dlm))
480		return DLM_REJECTED;
481
482	name = create->name;
483	namelen = create->namelen;
484	status = DLM_REJECTED;
485	if (!dlm_domain_fully_joined(dlm)) {
486		mlog(ML_ERROR, "Domain %s not fully joined, but node %u is "
487		     "sending a create_lock message for lock %.*s!\n",
488		     dlm->name, create->node_idx, namelen, name);
489		dlm_error(status);
490		goto leave;
491	}
492
493	status = DLM_IVBUFLEN;
494	if (namelen > DLM_LOCKID_NAME_MAX) {
495		dlm_error(status);
496		goto leave;
497	}
498
499	status = DLM_SYSERR;
500	newlock = dlm_new_lock(create->requested_type,
501			       create->node_idx,
502			       be64_to_cpu(create->cookie), NULL);
503	if (!newlock) {
504		dlm_error(status);
505		goto leave;
506	}
507
508	lksb = newlock->lksb;
509
510	if (be32_to_cpu(create->flags) & LKM_GET_LVB) {
511		lksb->flags |= DLM_LKSB_GET_LVB;
512		mlog(0, "set DLM_LKSB_GET_LVB flag\n");
513	}
514
515	status = DLM_IVLOCKID;
516	res = dlm_lookup_lockres(dlm, name, namelen);
517	if (!res) {
518		dlm_error(status);
519		goto leave;
520	}
521
522	spin_lock(&res->spinlock);
523	status = __dlm_lockres_state_to_status(res);
524	spin_unlock(&res->spinlock);
525
526	if (status != DLM_NORMAL) {
527		mlog(0, "lockres recovering/migrating/in-progress\n");
528		goto leave;
529	}
530
531	dlm_lock_attach_lockres(newlock, res);
532
533	status = dlmlock_master(dlm, res, newlock, be32_to_cpu(create->flags));
534leave:
535	if (status != DLM_NORMAL)
536		if (newlock)
537			dlm_lock_put(newlock);
538
539	if (res)
540		dlm_lockres_put(res);
541
542	dlm_put(dlm);
543
544	return status;
545}
546
547
548/* fetch next node-local (u8 nodenum + u56 cookie) into u64 */
549static inline void dlm_get_next_cookie(u8 node_num, u64 *cookie)
550{
551	u64 tmpnode = node_num;
552
553	/* shift single byte of node num into top 8 bits */
554	tmpnode <<= 56;
555
556	spin_lock(&dlm_cookie_lock);
557	*cookie = (dlm_next_cookie | tmpnode);
558	if (++dlm_next_cookie & 0xff00000000000000ull) {
559		mlog(0, "This node's cookie will now wrap!\n");
560		dlm_next_cookie = 1;
561	}
562	spin_unlock(&dlm_cookie_lock);
563}
564
565enum dlm_status dlmlock(struct dlm_ctxt *dlm, int mode,
566			struct dlm_lockstatus *lksb, int flags,
567			const char *name, int namelen, dlm_astlockfunc_t *ast,
568			void *data, dlm_bastlockfunc_t *bast)
569{
570	enum dlm_status status;
571	struct dlm_lock_resource *res = NULL;
572	struct dlm_lock *lock = NULL;
573	int convert = 0, recovery = 0;
574
575	/* yes this function is a mess.
576	 * TODO: clean this up.  lots of common code in the
577	 *       lock and convert paths, especially in the retry blocks */
578	if (!lksb) {
579		dlm_error(DLM_BADARGS);
580		return DLM_BADARGS;
581	}
582
583	status = DLM_BADPARAM;
584	if (mode != LKM_EXMODE && mode != LKM_PRMODE && mode != LKM_NLMODE) {
585		dlm_error(status);
586		goto error;
587	}
588
589	if (flags & ~LKM_VALID_FLAGS) {
590		dlm_error(status);
591		goto error;
592	}
593
594	convert = (flags & LKM_CONVERT);
595	recovery = (flags & LKM_RECOVERY);
596
597	if (recovery &&
598	    (!dlm_is_recovery_lock(name, namelen) || convert) ) {
599		dlm_error(status);
600		goto error;
601	}
602	if (convert && (flags & LKM_LOCAL)) {
603		mlog(ML_ERROR, "strange LOCAL convert request!\n");
604		goto error;
605	}
606
607	if (convert) {
608		/* CONVERT request */
609
610		/* if converting, must pass in a valid dlm_lock */
611		lock = lksb->lockid;
612		if (!lock) {
613			mlog(ML_ERROR, "NULL lock pointer in convert "
614			     "request\n");
615			goto error;
616		}
617
618		res = lock->lockres;
619		if (!res) {
620			mlog(ML_ERROR, "NULL lockres pointer in convert "
621			     "request\n");
622			goto error;
623		}
624		dlm_lockres_get(res);
625
626		if (lock->lksb != lksb || lock->ast != ast ||
627		    lock->bast != bast || lock->astdata != data) {
628			status = DLM_BADARGS;
629			mlog(ML_ERROR, "new args:  lksb=%p, ast=%p, bast=%p, "
630			     "astdata=%p\n", lksb, ast, bast, data);
631			mlog(ML_ERROR, "orig args: lksb=%p, ast=%p, bast=%p, "
632			     "astdata=%p\n", lock->lksb, lock->ast,
633			     lock->bast, lock->astdata);
634			goto error;
635		}
636retry_convert:
637		dlm_wait_for_recovery(dlm);
638
639		if (res->owner == dlm->node_num)
640			status = dlmconvert_master(dlm, res, lock, flags, mode);
641		else
642			status = dlmconvert_remote(dlm, res, lock, flags, mode);
643		if (status == DLM_RECOVERING || status == DLM_MIGRATING ||
644		    status == DLM_FORWARD) {
645			/* for now, see how this works without sleeping
646			 * and just retry right away.  I suspect the reco
647			 * or migration will complete fast enough that
648			 * no waiting will be necessary */
649			mlog(0, "retrying convert with migration/recovery/"
650			     "in-progress\n");
651			msleep(100);
652			goto retry_convert;
653		}
654	} else {
655		u64 tmpcookie;
656
657		/* LOCK request */
658		status = DLM_BADARGS;
659		if (!name) {
660			dlm_error(status);
661			goto error;
662		}
663
664		status = DLM_IVBUFLEN;
665		if (namelen > DLM_LOCKID_NAME_MAX || namelen < 1) {
666			dlm_error(status);
667			goto error;
668		}
669
670		dlm_get_next_cookie(dlm->node_num, &tmpcookie);
671		lock = dlm_new_lock(mode, dlm->node_num, tmpcookie, lksb);
672		if (!lock) {
673			dlm_error(status);
674			goto error;
675		}
676
677		if (!recovery)
678			dlm_wait_for_recovery(dlm);
679
680		/* find or create the lock resource */
681		res = dlm_get_lock_resource(dlm, name, namelen, flags);
682		if (!res) {
683			status = DLM_IVLOCKID;
684			dlm_error(status);
685			goto error;
686		}
687
688		mlog(0, "type=%d, flags = 0x%x\n", mode, flags);
689		mlog(0, "creating lock: lock=%p res=%p\n", lock, res);
690
691		dlm_lock_attach_lockres(lock, res);
692		lock->ast = ast;
693		lock->bast = bast;
694		lock->astdata = data;
695
696retry_lock:
697		if (flags & LKM_VALBLK) {
698			mlog(0, "LKM_VALBLK passed by caller\n");
699
700			/* LVB requests for non PR, PW or EX locks are
701			 * ignored. */
702			if (mode < LKM_PRMODE)
703				flags &= ~LKM_VALBLK;
704			else {
705				flags |= LKM_GET_LVB;
706				lock->lksb->flags |= DLM_LKSB_GET_LVB;
707			}
708		}
709
710		if (res->owner == dlm->node_num)
711			status = dlmlock_master(dlm, res, lock, flags);
712		else
713			status = dlmlock_remote(dlm, res, lock, flags);
714
715		if (status == DLM_RECOVERING || status == DLM_MIGRATING ||
716		    status == DLM_FORWARD) {
717			mlog(0, "retrying lock with migration/"
718			     "recovery/in progress\n");
719			msleep(100);
720			/* no waiting for dlm_reco_thread */
721			if (recovery) {
722				if (status != DLM_RECOVERING)
723					goto retry_lock;
724
725				mlog(0, "%s: got RECOVERING "
726				     "for $RECOVERY lock, master "
727				     "was %u\n", dlm->name,
728				     res->owner);
729				/* wait to see the node go down, then
730				 * drop down and allow the lockres to
731				 * get cleaned up.  need to remaster. */
732				dlm_wait_for_node_death(dlm, res->owner,
733						DLM_NODE_DEATH_WAIT_MAX);
734			} else {
735				dlm_wait_for_recovery(dlm);
736				goto retry_lock;
737			}
738		}
739
740		if (status != DLM_NORMAL) {
741			lock->lksb->flags &= ~DLM_LKSB_GET_LVB;
742			if (status != DLM_NOTQUEUED)
743				dlm_error(status);
744			goto error;
745		}
746	}
747
748error:
749	if (status != DLM_NORMAL) {
750		if (lock && !convert)
751			dlm_lock_put(lock);
752		// this is kind of unnecessary
753		lksb->status = status;
754	}
755
756	/* put lockres ref from the convert path
757	 * or from dlm_get_lock_resource */
758	if (res)
759		dlm_lockres_put(res);
760
761	return status;
762}
763EXPORT_SYMBOL_GPL(dlmlock);
764