1 /* -*- mode: c; c-basic-offset: 8; -*-
2 * vim: noexpandtab sw=8 ts=8 sts=0:
6 * underlying calls for lock creation
8 * Copyright (C) 2004 Oracle. All rights reserved.
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.
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.
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.
28 #include <linux/module.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>
43 #include "cluster/heartbeat.h"
44 #include "cluster/nodemanager.h"
45 #include "cluster/tcp.h"
48 #include "dlmcommon.h"
50 #include "dlmconvert.h"
52 #define MLOG_MASK_PREFIX ML_DLM
53 #include "cluster/masklog.h"
55 static struct kmem_cache
*dlm_lock_cache
= NULL
;
57 static DEFINE_SPINLOCK(dlm_cookie_lock
);
58 static u64 dlm_next_cookie
= 1;
60 static 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
);
63 static void dlm_init_lock(struct dlm_lock
*newlock
, int type
,
65 static void dlm_lock_release(struct kref
*kref
);
66 static void dlm_lock_detach_lockres(struct dlm_lock
*lock
);
68 int dlm_init_lock_cache(void)
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
)
78 void dlm_destroy_lock_cache(void)
81 kmem_cache_destroy(dlm_lock_cache
);
84 /* Tell us whether we can grant a new lock request.
86 * caller needs: res->spinlock
89 * returns: 1 if the lock can be granted, 0 otherwise.
91 static int dlm_can_grant_new_lock(struct dlm_lock_resource
*res
,
92 struct dlm_lock
*lock
)
94 struct list_head
*iter
;
95 struct dlm_lock
*tmplock
;
97 list_for_each(iter
, &res
->granted
) {
98 tmplock
= list_entry(iter
, struct dlm_lock
, list
);
100 if (!dlm_lock_compatible(tmplock
->ml
.type
, lock
->ml
.type
))
104 list_for_each(iter
, &res
->converting
) {
105 tmplock
= list_entry(iter
, struct dlm_lock
, list
);
107 if (!dlm_lock_compatible(tmplock
->ml
.type
, lock
->ml
.type
))
114 /* performs lock creation at the lockres master site
117 * taken: takes and drops res->spinlock
119 * returns: DLM_NORMAL, DLM_NOTQUEUED
121 static enum dlm_status
dlmlock_master(struct dlm_ctxt
*dlm
,
122 struct dlm_lock_resource
*res
,
123 struct dlm_lock
*lock
, int flags
)
125 int call_ast
= 0, kick_thread
= 0;
126 enum dlm_status status
= DLM_NORMAL
;
128 mlog_entry("type=%d\n", lock
->ml
.type
);
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
);
141 __dlm_wait_on_lockres(res
);
142 __dlm_lockres_reserve_ast(res
);
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
;
150 list_add_tail(&lock
->list
, &res
->granted
);
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
)) {
162 mlog(0, "%s: returning DLM_NORMAL to "
163 "node %u for reco lock\n", dlm
->name
,
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
,
179 list_add_tail(&lock
->list
, &res
->blocked
);
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
);
188 spin_unlock(&res
->spinlock
);
191 /* either queue the ast or release it */
193 dlm_queue_ast(dlm
, lock
);
195 dlm_lockres_release_ast(dlm
, res
);
197 dlm_lockres_calc_usage(dlm
, res
);
199 dlm_kick_thread(dlm
, res
);
204 void dlm_revert_pending_lock(struct dlm_lock_resource
*res
,
205 struct dlm_lock
*lock
)
207 /* remove from local queue if it failed */
208 list_del_init(&lock
->list
);
209 lock
->lksb
->flags
&= ~DLM_LKSB_GET_LVB
;
216 * taken: takes and drops res->spinlock
218 * returns: DLM_DENIED, DLM_RECOVERING, or net status
220 static enum dlm_status
dlmlock_remote(struct dlm_ctxt
*dlm
,
221 struct dlm_lock_resource
*res
,
222 struct dlm_lock
*lock
, int flags
)
224 enum dlm_status status
= DLM_DENIED
;
225 int lockres_changed
= 1;
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
);
231 spin_lock(&res
->spinlock
);
233 /* will exit this call with spinlock held */
234 __dlm_wait_on_lockres(res
);
235 res
->state
|= DLM_LOCK_RES_IN_PROGRESS
;
237 /* add lock to local (secondary) queue */
239 list_add_tail(&lock
->list
, &res
->blocked
);
240 lock
->lock_pending
= 1;
241 spin_unlock(&res
->spinlock
);
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
);
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
) {
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
270 dlm_revert_pending_lock(res
, 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
);
283 spin_unlock(&res
->spinlock
);
286 dlm_lockres_calc_usage(dlm
, res
);
293 /* for remote lock creation.
295 * caller needs: none, but need res->state & DLM_LOCK_RES_IN_PROGRESS
298 * returns: DLM_NOLOCKMGR, or net status
300 static 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
)
304 struct dlm_create_lock create
;
305 int tmpret
, status
= 0;
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
);
318 tmpret
= o2net_send_message(DLM_CREATE_LOCK_MSG
, dlm
->key
, &create
,
319 sizeof(create
), res
->owner
, &status
);
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
);
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
,
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
);
340 ret
= dlm_err_to_dlm_status(tmpret
);
347 void dlm_lock_get(struct dlm_lock
*lock
)
349 kref_get(&lock
->lock_refs
);
352 void dlm_lock_put(struct dlm_lock
*lock
)
354 kref_put(&lock
->lock_refs
, dlm_lock_release
);
357 static void dlm_lock_release(struct kref
*kref
)
359 struct dlm_lock
*lock
;
361 lock
= container_of(kref
, struct dlm_lock
, lock_refs
);
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
);
369 dlm_lock_detach_lockres(lock
);
371 if (lock
->lksb_kernel_allocated
) {
372 mlog(0, "freeing kernel-allocated lksb\n");
375 kmem_cache_free(dlm_lock_cache
, lock
);
378 /* associate a lock with it's lockres, getting a ref on the lockres */
379 void dlm_lock_attach_lockres(struct dlm_lock
*lock
,
380 struct dlm_lock_resource
*res
)
382 dlm_lockres_get(res
);
386 /* drop ref on lockres, if there is still one associated with lock */
387 static void dlm_lock_detach_lockres(struct dlm_lock
*lock
)
389 struct dlm_lock_resource
*res
;
393 lock
->lockres
= NULL
;
394 mlog(0, "removing lock's lockres reference\n");
395 dlm_lockres_put(res
);
399 static void dlm_init_lock(struct dlm_lock
*newlock
, int type
,
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;
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;
425 kref_init(&newlock
->lock_refs
);
428 struct dlm_lock
* dlm_new_lock(int type
, u8 node
, u64 cookie
,
429 struct dlm_lockstatus
*lksb
)
431 struct dlm_lock
*lock
;
432 int kernel_allocated
= 0;
434 lock
= kmem_cache_zalloc(dlm_lock_cache
, GFP_NOFS
);
439 /* zero memory only if kernel-allocated */
440 lksb
= kzalloc(sizeof(*lksb
), GFP_NOFS
);
445 kernel_allocated
= 1;
448 dlm_init_lock(lock
, type
, node
, cookie
);
449 if (kernel_allocated
)
450 lock
->lksb_kernel_allocated
= 1;
456 /* handler for lock creation net message
459 * taken: takes and drops res->spinlock
461 * returns: DLM_NORMAL, DLM_SYSERR, DLM_IVLOCKID, DLM_NOTQUEUED
463 int dlm_create_lock_handler(struct o2net_msg
*msg
, u32 len
, void *data
,
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
;
473 unsigned int namelen
;
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
);
493 status
= DLM_IVBUFLEN
;
494 if (namelen
> DLM_LOCKID_NAME_MAX
) {
500 newlock
= dlm_new_lock(create
->requested_type
,
502 be64_to_cpu(create
->cookie
), NULL
);
508 lksb
= newlock
->lksb
;
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");
515 status
= DLM_IVLOCKID
;
516 res
= dlm_lookup_lockres(dlm
, name
, namelen
);
522 spin_lock(&res
->spinlock
);
523 status
= __dlm_lockres_state_to_status(res
);
524 spin_unlock(&res
->spinlock
);
526 if (status
!= DLM_NORMAL
) {
527 mlog(0, "lockres recovering/migrating/in-progress\n");
531 dlm_lock_attach_lockres(newlock
, res
);
533 status
= dlmlock_master(dlm
, res
, newlock
, be32_to_cpu(create
->flags
));
535 if (status
!= DLM_NORMAL
)
537 dlm_lock_put(newlock
);
540 dlm_lockres_put(res
);
548 /* fetch next node-local (u8 nodenum + u56 cookie) into u64 */
549 static inline void dlm_get_next_cookie(u8 node_num
, u64
*cookie
)
551 u64 tmpnode
= node_num
;
553 /* shift single byte of node num into top 8 bits */
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");
562 spin_unlock(&dlm_cookie_lock
);
565 enum 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
)
570 enum dlm_status status
;
571 struct dlm_lock_resource
*res
= NULL
;
572 struct dlm_lock
*lock
= NULL
;
573 int convert
= 0, recovery
= 0;
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 */
579 dlm_error(DLM_BADARGS
);
583 status
= DLM_BADPARAM
;
584 if (mode
!= LKM_EXMODE
&& mode
!= LKM_PRMODE
&& mode
!= LKM_NLMODE
) {
589 if (flags
& ~LKM_VALID_FLAGS
) {
594 convert
= (flags
& LKM_CONVERT
);
595 recovery
= (flags
& LKM_RECOVERY
);
598 (!dlm_is_recovery_lock(name
, namelen
) || convert
) ) {
602 if (convert
&& (flags
& LKM_LOCAL
)) {
603 mlog(ML_ERROR
, "strange LOCAL convert request!\n");
608 /* CONVERT request */
610 /* if converting, must pass in a valid dlm_lock */
613 mlog(ML_ERROR
, "NULL lock pointer in convert "
620 mlog(ML_ERROR
, "NULL lockres pointer in convert "
624 dlm_lockres_get(res
);
626 /* XXX: for ocfs2 purposes, the ast/bast/astdata/lksb are
627 * static after the original lock call. convert requests will
628 * ensure that everything is the same, or return DLM_BADARGS.
629 * this means that DLM_DENIED_NOASTS will never be returned.
631 if (lock
->lksb
!= lksb
|| lock
->ast
!= ast
||
632 lock
->bast
!= bast
|| lock
->astdata
!= data
) {
633 status
= DLM_BADARGS
;
634 mlog(ML_ERROR
, "new args: lksb=%p, ast=%p, bast=%p, "
635 "astdata=%p\n", lksb
, ast
, bast
, data
);
636 mlog(ML_ERROR
, "orig args: lksb=%p, ast=%p, bast=%p, "
637 "astdata=%p\n", lock
->lksb
, lock
->ast
,
638 lock
->bast
, lock
->astdata
);
642 dlm_wait_for_recovery(dlm
);
644 if (res
->owner
== dlm
->node_num
)
645 status
= dlmconvert_master(dlm
, res
, lock
, flags
, mode
);
647 status
= dlmconvert_remote(dlm
, res
, lock
, flags
, mode
);
648 if (status
== DLM_RECOVERING
|| status
== DLM_MIGRATING
||
649 status
== DLM_FORWARD
) {
650 /* for now, see how this works without sleeping
651 * and just retry right away. I suspect the reco
652 * or migration will complete fast enough that
653 * no waiting will be necessary */
654 mlog(0, "retrying convert with migration/recovery/"
663 status
= DLM_BADARGS
;
669 status
= DLM_IVBUFLEN
;
670 if (namelen
> DLM_LOCKID_NAME_MAX
|| namelen
< 1) {
675 dlm_get_next_cookie(dlm
->node_num
, &tmpcookie
);
676 lock
= dlm_new_lock(mode
, dlm
->node_num
, tmpcookie
, lksb
);
683 dlm_wait_for_recovery(dlm
);
685 /* find or create the lock resource */
686 res
= dlm_get_lock_resource(dlm
, name
, namelen
, flags
);
688 status
= DLM_IVLOCKID
;
693 mlog(0, "type=%d, flags = 0x%x\n", mode
, flags
);
694 mlog(0, "creating lock: lock=%p res=%p\n", lock
, res
);
696 dlm_lock_attach_lockres(lock
, res
);
699 lock
->astdata
= data
;
702 if (flags
& LKM_VALBLK
) {
703 mlog(0, "LKM_VALBLK passed by caller\n");
705 /* LVB requests for non PR, PW or EX locks are
707 if (mode
< LKM_PRMODE
)
708 flags
&= ~LKM_VALBLK
;
710 flags
|= LKM_GET_LVB
;
711 lock
->lksb
->flags
|= DLM_LKSB_GET_LVB
;
715 if (res
->owner
== dlm
->node_num
)
716 status
= dlmlock_master(dlm
, res
, lock
, flags
);
718 status
= dlmlock_remote(dlm
, res
, lock
, flags
);
720 if (status
== DLM_RECOVERING
|| status
== DLM_MIGRATING
||
721 status
== DLM_FORWARD
) {
722 mlog(0, "retrying lock with migration/"
723 "recovery/in progress\n");
725 /* no waiting for dlm_reco_thread */
727 if (status
!= DLM_RECOVERING
)
730 mlog(0, "%s: got RECOVERING "
731 "for $RECOVERY lock, master "
732 "was %u\n", dlm
->name
,
734 /* wait to see the node go down, then
735 * drop down and allow the lockres to
736 * get cleaned up. need to remaster. */
737 dlm_wait_for_node_death(dlm
, res
->owner
,
738 DLM_NODE_DEATH_WAIT_MAX
);
740 dlm_wait_for_recovery(dlm
);
745 if (status
!= DLM_NORMAL
) {
746 lock
->lksb
->flags
&= ~DLM_LKSB_GET_LVB
;
747 if (status
!= DLM_NOTQUEUED
)
754 if (status
!= DLM_NORMAL
) {
755 if (lock
&& !convert
)
757 // this is kind of unnecessary
758 lksb
->status
= status
;
761 /* put lockres ref from the convert path
762 * or from dlm_get_lock_resource */
764 dlm_lockres_put(res
);
768 EXPORT_SYMBOL_GPL(dlmlock
);