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[DLM] Use workqueues for dlm lowcomms
[deliverable/linux.git] / fs / dlm / lock.c
CommitLineData
e7fd4179
DT		 1/******************************************************************************
2*******************************************************************************
3**
4** Copyright (C) 2005 Red Hat, Inc. All rights reserved.
5**
6** This copyrighted material is made available to anyone wishing to use,
7** modify, copy, or redistribute it subject to the terms and conditions
8** of the GNU General Public License v.2.
9**
10*******************************************************************************
11******************************************************************************/
12
13/* Central locking logic has four stages:
14
15 dlm_lock()
16 dlm_unlock()
17
18 request_lock(ls, lkb)
19 convert_lock(ls, lkb)
20 unlock_lock(ls, lkb)
21 cancel_lock(ls, lkb)
22
23 _request_lock(r, lkb)
24 _convert_lock(r, lkb)
25 _unlock_lock(r, lkb)
26 _cancel_lock(r, lkb)
27
28 do_request(r, lkb)
29 do_convert(r, lkb)
30 do_unlock(r, lkb)
31 do_cancel(r, lkb)
32
33 Stage 1 (lock, unlock) is mainly about checking input args and
34 splitting into one of the four main operations:
35
36 dlm_lock = request_lock
37 dlm_lock+CONVERT = convert_lock
38 dlm_unlock = unlock_lock
39 dlm_unlock+CANCEL = cancel_lock
40
41 Stage 2, xxxx_lock(), just finds and locks the relevant rsb which is
42 provided to the next stage.
43
44 Stage 3, _xxxx_lock(), determines if the operation is local or remote.
45 When remote, it calls send_xxxx(), when local it calls do_xxxx().
46
47 Stage 4, do_xxxx(), is the guts of the operation. It manipulates the
48 given rsb and lkb and queues callbacks.
49
50 For remote operations, send_xxxx() results in the corresponding do_xxxx()
51 function being executed on the remote node. The connecting send/receive
52 calls on local (L) and remote (R) nodes:
53
54 L: send_xxxx() -> R: receive_xxxx()
55 R: do_xxxx()
56 L: receive_xxxx_reply() <- R: send_xxxx_reply()
57*/
597d0cae 58#include <linux/types.h>
e7fd4179 59#include "dlm_internal.h"
597d0cae 60#include <linux/dlm_device.h>
e7fd4179
DT		 61#include "memory.h"
62#include "lowcomms.h"
63#include "requestqueue.h"
64#include "util.h"
65#include "dir.h"
66#include "member.h"
67#include "lockspace.h"
68#include "ast.h"
69#include "lock.h"
70#include "rcom.h"
71#include "recover.h"
72#include "lvb_table.h"
597d0cae 73#include "user.h"
e7fd4179
DT		 74#include "config.h"
75
76static int send_request(struct dlm_rsb *r, struct dlm_lkb *lkb);
77static int send_convert(struct dlm_rsb *r, struct dlm_lkb *lkb);
78static int send_unlock(struct dlm_rsb *r, struct dlm_lkb *lkb);
79static int send_cancel(struct dlm_rsb *r, struct dlm_lkb *lkb);
80static int send_grant(struct dlm_rsb *r, struct dlm_lkb *lkb);
81static int send_bast(struct dlm_rsb *r, struct dlm_lkb *lkb, int mode);
82static int send_lookup(struct dlm_rsb *r, struct dlm_lkb *lkb);
83static int send_remove(struct dlm_rsb *r);
84static int _request_lock(struct dlm_rsb *r, struct dlm_lkb *lkb);
85static void __receive_convert_reply(struct dlm_rsb *r, struct dlm_lkb *lkb,
86 struct dlm_message *ms);
87static int receive_extralen(struct dlm_message *ms);
88
89/*
90 * Lock compatibilty matrix - thanks Steve
91 * UN = Unlocked state. Not really a state, used as a flag
92 * PD = Padding. Used to make the matrix a nice power of two in size
93 * Other states are the same as the VMS DLM.
94 * Usage: matrix[grmode+1][rqmode+1] (although m[rq+1][gr+1] is the same)
95 */
96
97static const int __dlm_compat_matrix[8][8] = {
98 /* UN NL CR CW PR PW EX PD */
99 {1, 1, 1, 1, 1, 1, 1, 0}, /* UN */
100 {1, 1, 1, 1, 1, 1, 1, 0}, /* NL */
101 {1, 1, 1, 1, 1, 1, 0, 0}, /* CR */
102 {1, 1, 1, 1, 0, 0, 0, 0}, /* CW */
103 {1, 1, 1, 0, 1, 0, 0, 0}, /* PR */
104 {1, 1, 1, 0, 0, 0, 0, 0}, /* PW */
105 {1, 1, 0, 0, 0, 0, 0, 0}, /* EX */
106 {0, 0, 0, 0, 0, 0, 0, 0} /* PD */
107};
108
109/*
110 * This defines the direction of transfer of LVB data.
111 * Granted mode is the row; requested mode is the column.
112 * Usage: matrix[grmode+1][rqmode+1]
113 * 1 = LVB is returned to the caller
114 * 0 = LVB is written to the resource
115 * -1 = nothing happens to the LVB
116 */
117
118const int dlm_lvb_operations[8][8] = {
119 /* UN NL CR CW PR PW EX PD*/
120 { -1, 1, 1, 1, 1, 1, 1, -1 }, /* UN */
121 { -1, 1, 1, 1, 1, 1, 1, 0 }, /* NL */
122 { -1, -1, 1, 1, 1, 1, 1, 0 }, /* CR */
123 { -1, -1, -1, 1, 1, 1, 1, 0 }, /* CW */
124 { -1, -1, -1, -1, 1, 1, 1, 0 }, /* PR */
125 { -1, 0, 0, 0, 0, 0, 1, 0 }, /* PW */
126 { -1, 0, 0, 0, 0, 0, 0, 0 }, /* EX */
127 { -1, 0, 0, 0, 0, 0, 0, 0 } /* PD */
128};
e7fd4179
DT		 129
130#define modes_compat(gr, rq) \
131 __dlm_compat_matrix[(gr)->lkb_grmode + 1][(rq)->lkb_rqmode + 1]
132
133int dlm_modes_compat(int mode1, int mode2)
134{
135 return __dlm_compat_matrix[mode1 + 1][mode2 + 1];
136}
137
138/*
139 * Compatibility matrix for conversions with QUECVT set.
140 * Granted mode is the row; requested mode is the column.
141 * Usage: matrix[grmode+1][rqmode+1]
142 */
143
144static const int __quecvt_compat_matrix[8][8] = {
145 /* UN NL CR CW PR PW EX PD */
146 {0, 0, 0, 0, 0, 0, 0, 0}, /* UN */
147 {0, 0, 1, 1, 1, 1, 1, 0}, /* NL */
148 {0, 0, 0, 1, 1, 1, 1, 0}, /* CR */
149 {0, 0, 0, 0, 1, 1, 1, 0}, /* CW */
150 {0, 0, 0, 1, 0, 1, 1, 0}, /* PR */
151 {0, 0, 0, 0, 0, 0, 1, 0}, /* PW */
152 {0, 0, 0, 0, 0, 0, 0, 0}, /* EX */
153 {0, 0, 0, 0, 0, 0, 0, 0} /* PD */
154};
155
597d0cae 156void dlm_print_lkb(struct dlm_lkb *lkb)
e7fd4179
DT		 157{
158 printk(KERN_ERR "lkb: nodeid %d id %x remid %x exflags %x flags %x\n"
159 " status %d rqmode %d grmode %d wait_type %d ast_type %d\n",
160 lkb->lkb_nodeid, lkb->lkb_id, lkb->lkb_remid, lkb->lkb_exflags,
161 lkb->lkb_flags, lkb->lkb_status, lkb->lkb_rqmode,
162 lkb->lkb_grmode, lkb->lkb_wait_type, lkb->lkb_ast_type);
163}
164
165void dlm_print_rsb(struct dlm_rsb *r)
166{
167 printk(KERN_ERR "rsb: nodeid %d flags %lx first %x rlc %d name %s\n",
168 r->res_nodeid, r->res_flags, r->res_first_lkid,
169 r->res_recover_locks_count, r->res_name);
170}
171
a345da3e
DT		 172void dlm_dump_rsb(struct dlm_rsb *r)
173{
174 struct dlm_lkb *lkb;
175
176 dlm_print_rsb(r);
177
178 printk(KERN_ERR "rsb: root_list empty %d recover_list empty %d\n",
179 list_empty(&r->res_root_list), list_empty(&r->res_recover_list));
180 printk(KERN_ERR "rsb lookup list\n");
181 list_for_each_entry(lkb, &r->res_lookup, lkb_rsb_lookup)
182 dlm_print_lkb(lkb);
183 printk(KERN_ERR "rsb grant queue:\n");
184 list_for_each_entry(lkb, &r->res_grantqueue, lkb_statequeue)
185 dlm_print_lkb(lkb);
186 printk(KERN_ERR "rsb convert queue:\n");
187 list_for_each_entry(lkb, &r->res_convertqueue, lkb_statequeue)
188 dlm_print_lkb(lkb);
189 printk(KERN_ERR "rsb wait queue:\n");
190 list_for_each_entry(lkb, &r->res_waitqueue, lkb_statequeue)
191 dlm_print_lkb(lkb);
192}
193
e7fd4179
DT		 194/* Threads cannot use the lockspace while it's being recovered */
195
196static inline void lock_recovery(struct dlm_ls *ls)
197{
198 down_read(&ls->ls_in_recovery);
199}
200
201static inline void unlock_recovery(struct dlm_ls *ls)
202{
203 up_read(&ls->ls_in_recovery);
204}
205
206static inline int lock_recovery_try(struct dlm_ls *ls)
207{
208 return down_read_trylock(&ls->ls_in_recovery);
209}
210
211static inline int can_be_queued(struct dlm_lkb *lkb)
212{
213 return !(lkb->lkb_exflags & DLM_LKF_NOQUEUE);
214}
215
216static inline int force_blocking_asts(struct dlm_lkb *lkb)
217{
218 return (lkb->lkb_exflags & DLM_LKF_NOQUEUEBAST);
219}
220
221static inline int is_demoted(struct dlm_lkb *lkb)
222{
223 return (lkb->lkb_sbflags & DLM_SBF_DEMOTED);
224}
225
226static inline int is_remote(struct dlm_rsb *r)
227{
228 DLM_ASSERT(r->res_nodeid >= 0, dlm_print_rsb(r););
229 return !!r->res_nodeid;
230}
231
232static inline int is_process_copy(struct dlm_lkb *lkb)
233{
234 return (lkb->lkb_nodeid && !(lkb->lkb_flags & DLM_IFL_MSTCPY));
235}
236
237static inline int is_master_copy(struct dlm_lkb *lkb)
238{
239 if (lkb->lkb_flags & DLM_IFL_MSTCPY)
240 DLM_ASSERT(lkb->lkb_nodeid, dlm_print_lkb(lkb););
90135925 241 return (lkb->lkb_flags & DLM_IFL_MSTCPY) ? 1 : 0;
e7fd4179
DT		 242}
243
244static inline int middle_conversion(struct dlm_lkb *lkb)
245{
246 if ((lkb->lkb_grmode==DLM_LOCK_PR && lkb->lkb_rqmode==DLM_LOCK_CW) ||
247 (lkb->lkb_rqmode==DLM_LOCK_PR && lkb->lkb_grmode==DLM_LOCK_CW))
90135925
DT		 248 return 1;
249 return 0;
e7fd4179
DT		 250}
251
252static inline int down_conversion(struct dlm_lkb *lkb)
253{
254 return (!middle_conversion(lkb) && lkb->lkb_rqmode < lkb->lkb_grmode);
255}
256
257static void queue_cast(struct dlm_rsb *r, struct dlm_lkb *lkb, int rv)
258{
259 if (is_master_copy(lkb))
260 return;
261
262 DLM_ASSERT(lkb->lkb_lksb, dlm_print_lkb(lkb););
263
264 lkb->lkb_lksb->sb_status = rv;
265 lkb->lkb_lksb->sb_flags = lkb->lkb_sbflags;
266
267 dlm_add_ast(lkb, AST_COMP);
268}
269
270static void queue_bast(struct dlm_rsb *r, struct dlm_lkb *lkb, int rqmode)
271{
272 if (is_master_copy(lkb))
273 send_bast(r, lkb, rqmode);
274 else {
275 lkb->lkb_bastmode = rqmode;
276 dlm_add_ast(lkb, AST_BAST);
277 }
278}
279
280/*
281 * Basic operations on rsb's and lkb's
282 */
283
284static struct dlm_rsb *create_rsb(struct dlm_ls *ls, char *name, int len)
285{
286 struct dlm_rsb *r;
287
288 r = allocate_rsb(ls, len);
289 if (!r)
290 return NULL;
291
292 r->res_ls = ls;
293 r->res_length = len;
294 memcpy(r->res_name, name, len);
90135925 295 mutex_init(&r->res_mutex);
e7fd4179
DT		 296
297 INIT_LIST_HEAD(&r->res_lookup);
298 INIT_LIST_HEAD(&r->res_grantqueue);
299 INIT_LIST_HEAD(&r->res_convertqueue);
300 INIT_LIST_HEAD(&r->res_waitqueue);
301 INIT_LIST_HEAD(&r->res_root_list);
302 INIT_LIST_HEAD(&r->res_recover_list);
303
304 return r;
305}
306
307static int search_rsb_list(struct list_head *head, char *name, int len,
308 unsigned int flags, struct dlm_rsb **r_ret)
309{
310 struct dlm_rsb *r;
311 int error = 0;
312
313 list_for_each_entry(r, head, res_hashchain) {
314 if (len == r->res_length && !memcmp(name, r->res_name, len))
315 goto found;
316 }
597d0cae 317 return -EBADR;
e7fd4179
DT		 318
319 found:
320 if (r->res_nodeid && (flags & R_MASTER))
321 error = -ENOTBLK;
322 *r_ret = r;
323 return error;
324}
325
326static int _search_rsb(struct dlm_ls *ls, char *name, int len, int b,
327 unsigned int flags, struct dlm_rsb **r_ret)
328{
329 struct dlm_rsb *r;
330 int error;
331
332 error = search_rsb_list(&ls->ls_rsbtbl[b].list, name, len, flags, &r);
333 if (!error) {
334 kref_get(&r->res_ref);
335 goto out;
336 }
337 error = search_rsb_list(&ls->ls_rsbtbl[b].toss, name, len, flags, &r);
338 if (error)
339 goto out;
340
341 list_move(&r->res_hashchain, &ls->ls_rsbtbl[b].list);
342
343 if (dlm_no_directory(ls))
344 goto out;
345
346 if (r->res_nodeid == -1) {
347 rsb_clear_flag(r, RSB_MASTER_UNCERTAIN);
348 r->res_first_lkid = 0;
349 } else if (r->res_nodeid > 0) {
350 rsb_set_flag(r, RSB_MASTER_UNCERTAIN);
351 r->res_first_lkid = 0;
352 } else {
353 DLM_ASSERT(r->res_nodeid == 0, dlm_print_rsb(r););
354 DLM_ASSERT(!rsb_flag(r, RSB_MASTER_UNCERTAIN),);
355 }
356 out:
357 *r_ret = r;
358 return error;
359}
360
361static int search_rsb(struct dlm_ls *ls, char *name, int len, int b,
362 unsigned int flags, struct dlm_rsb **r_ret)
363{
364 int error;
365 write_lock(&ls->ls_rsbtbl[b].lock);
366 error = _search_rsb(ls, name, len, b, flags, r_ret);
367 write_unlock(&ls->ls_rsbtbl[b].lock);
368 return error;
369}
370
371/*
372 * Find rsb in rsbtbl and potentially create/add one
373 *
374 * Delaying the release of rsb's has a similar benefit to applications keeping
375 * NL locks on an rsb, but without the guarantee that the cached master value
376 * will still be valid when the rsb is reused. Apps aren't always smart enough
377 * to keep NL locks on an rsb that they may lock again shortly; this can lead
378 * to excessive master lookups and removals if we don't delay the release.
379 *
380 * Searching for an rsb means looking through both the normal list and toss
381 * list. When found on the toss list the rsb is moved to the normal list with
382 * ref count of 1; when found on normal list the ref count is incremented.
383 */
384
385static int find_rsb(struct dlm_ls *ls, char *name, int namelen,
386 unsigned int flags, struct dlm_rsb **r_ret)
387{
388 struct dlm_rsb *r, *tmp;
389 uint32_t hash, bucket;
390 int error = 0;
391
392 if (dlm_no_directory(ls))
393 flags |= R_CREATE;
394
395 hash = jhash(name, namelen, 0);
396 bucket = hash & (ls->ls_rsbtbl_size - 1);
397
398 error = search_rsb(ls, name, namelen, bucket, flags, &r);
399 if (!error)
400 goto out;
401
597d0cae 402 if (error == -EBADR && !(flags & R_CREATE))
e7fd4179
DT		 403 goto out;
404
405 /* the rsb was found but wasn't a master copy */
406 if (error == -ENOTBLK)
407 goto out;
408
409 error = -ENOMEM;
410 r = create_rsb(ls, name, namelen);
411 if (!r)
412 goto out;
413
414 r->res_hash = hash;
415 r->res_bucket = bucket;
416 r->res_nodeid = -1;
417 kref_init(&r->res_ref);
418
419 /* With no directory, the master can be set immediately */
420 if (dlm_no_directory(ls)) {
421 int nodeid = dlm_dir_nodeid(r);
422 if (nodeid == dlm_our_nodeid())
423 nodeid = 0;
424 r->res_nodeid = nodeid;
425 }
426
427 write_lock(&ls->ls_rsbtbl[bucket].lock);
428 error = _search_rsb(ls, name, namelen, bucket, 0, &tmp);
429 if (!error) {
430 write_unlock(&ls->ls_rsbtbl[bucket].lock);
431 free_rsb(r);
432 r = tmp;
433 goto out;
434 }
435 list_add(&r->res_hashchain, &ls->ls_rsbtbl[bucket].list);
436 write_unlock(&ls->ls_rsbtbl[bucket].lock);
437 error = 0;
438 out:
439 *r_ret = r;
440 return error;
441}
442
443int dlm_find_rsb(struct dlm_ls *ls, char *name, int namelen,
444 unsigned int flags, struct dlm_rsb **r_ret)
445{
446 return find_rsb(ls, name, namelen, flags, r_ret);
447}
448
449/* This is only called to add a reference when the code already holds
450 a valid reference to the rsb, so there's no need for locking. */
451
452static inline void hold_rsb(struct dlm_rsb *r)
453{
454 kref_get(&r->res_ref);
455}
456
457void dlm_hold_rsb(struct dlm_rsb *r)
458{
459 hold_rsb(r);
460}
461
462static void toss_rsb(struct kref *kref)
463{
464 struct dlm_rsb *r = container_of(kref, struct dlm_rsb, res_ref);
465 struct dlm_ls *ls = r->res_ls;
466
467 DLM_ASSERT(list_empty(&r->res_root_list), dlm_print_rsb(r););
468 kref_init(&r->res_ref);
469 list_move(&r->res_hashchain, &ls->ls_rsbtbl[r->res_bucket].toss);
470 r->res_toss_time = jiffies;
471 if (r->res_lvbptr) {
472 free_lvb(r->res_lvbptr);
473 r->res_lvbptr = NULL;
474 }
475}
476
477/* When all references to the rsb are gone it's transfered to
478 the tossed list for later disposal. */
479
480static void put_rsb(struct dlm_rsb *r)
481{
482 struct dlm_ls *ls = r->res_ls;
483 uint32_t bucket = r->res_bucket;
484
485 write_lock(&ls->ls_rsbtbl[bucket].lock);
486 kref_put(&r->res_ref, toss_rsb);
487 write_unlock(&ls->ls_rsbtbl[bucket].lock);
488}
489
490void dlm_put_rsb(struct dlm_rsb *r)
491{
492 put_rsb(r);
493}
494
495/* See comment for unhold_lkb */
496
497static void unhold_rsb(struct dlm_rsb *r)
498{
499 int rv;
500 rv = kref_put(&r->res_ref, toss_rsb);
a345da3e 501 DLM_ASSERT(!rv, dlm_dump_rsb(r););
e7fd4179
DT		 502}
503
504static void kill_rsb(struct kref *kref)
505{
506 struct dlm_rsb *r = container_of(kref, struct dlm_rsb, res_ref);
507
508 /* All work is done after the return from kref_put() so we
509 can release the write_lock before the remove and free. */
510
a345da3e
DT		 511 DLM_ASSERT(list_empty(&r->res_lookup), dlm_dump_rsb(r););
512 DLM_ASSERT(list_empty(&r->res_grantqueue), dlm_dump_rsb(r););
513 DLM_ASSERT(list_empty(&r->res_convertqueue), dlm_dump_rsb(r););
514 DLM_ASSERT(list_empty(&r->res_waitqueue), dlm_dump_rsb(r););
515 DLM_ASSERT(list_empty(&r->res_root_list), dlm_dump_rsb(r););
516 DLM_ASSERT(list_empty(&r->res_recover_list), dlm_dump_rsb(r););
e7fd4179
DT		 517}
518
519/* Attaching/detaching lkb's from rsb's is for rsb reference counting.
520 The rsb must exist as long as any lkb's for it do. */
521
522static void attach_lkb(struct dlm_rsb *r, struct dlm_lkb *lkb)
523{
524 hold_rsb(r);
525 lkb->lkb_resource = r;
526}
527
528static void detach_lkb(struct dlm_lkb *lkb)
529{
530 if (lkb->lkb_resource) {
531 put_rsb(lkb->lkb_resource);
532 lkb->lkb_resource = NULL;
533 }
534}
535
536static int create_lkb(struct dlm_ls *ls, struct dlm_lkb **lkb_ret)
537{
538 struct dlm_lkb *lkb, *tmp;
539 uint32_t lkid = 0;
540 uint16_t bucket;
541
542 lkb = allocate_lkb(ls);
543 if (!lkb)
544 return -ENOMEM;
545
546 lkb->lkb_nodeid = -1;
547 lkb->lkb_grmode = DLM_LOCK_IV;
548 kref_init(&lkb->lkb_ref);
34e22bed 549 INIT_LIST_HEAD(&lkb->lkb_ownqueue);
e7fd4179
DT		 550
551 get_random_bytes(&bucket, sizeof(bucket));
552 bucket &= (ls->ls_lkbtbl_size - 1);
553
554 write_lock(&ls->ls_lkbtbl[bucket].lock);
555
556 /* counter can roll over so we must verify lkid is not in use */
557
558 while (lkid == 0) {
559 lkid = bucket | (ls->ls_lkbtbl[bucket].counter++ << 16);
560
561 list_for_each_entry(tmp, &ls->ls_lkbtbl[bucket].list,
562 lkb_idtbl_list) {
563 if (tmp->lkb_id != lkid)
564 continue;
565 lkid = 0;
566 break;
567 }
568 }
569
570 lkb->lkb_id = lkid;
571 list_add(&lkb->lkb_idtbl_list, &ls->ls_lkbtbl[bucket].list);
572 write_unlock(&ls->ls_lkbtbl[bucket].lock);
573
574 *lkb_ret = lkb;
575 return 0;
576}
577
578static struct dlm_lkb *__find_lkb(struct dlm_ls *ls, uint32_t lkid)
579{
580 uint16_t bucket = lkid & 0xFFFF;
581 struct dlm_lkb *lkb;
582
583 list_for_each_entry(lkb, &ls->ls_lkbtbl[bucket].list, lkb_idtbl_list) {
584 if (lkb->lkb_id == lkid)
585 return lkb;
586 }
587 return NULL;
588}
589
590static int find_lkb(struct dlm_ls *ls, uint32_t lkid, struct dlm_lkb **lkb_ret)
591{
592 struct dlm_lkb *lkb;
593 uint16_t bucket = lkid & 0xFFFF;
594
595 if (bucket >= ls->ls_lkbtbl_size)
596 return -EBADSLT;
597
598 read_lock(&ls->ls_lkbtbl[bucket].lock);
599 lkb = __find_lkb(ls, lkid);
600 if (lkb)
601 kref_get(&lkb->lkb_ref);
602 read_unlock(&ls->ls_lkbtbl[bucket].lock);
603
604 *lkb_ret = lkb;
605 return lkb ? 0 : -ENOENT;
606}
607
608static void kill_lkb(struct kref *kref)
609{
610 struct dlm_lkb *lkb = container_of(kref, struct dlm_lkb, lkb_ref);
611
612 /* All work is done after the return from kref_put() so we
613 can release the write_lock before the detach_lkb */
614
615 DLM_ASSERT(!lkb->lkb_status, dlm_print_lkb(lkb););
616}
617
b3f58d8f
DT		 618/* __put_lkb() is used when an lkb may not have an rsb attached to
619 it so we need to provide the lockspace explicitly */
620
621static int __put_lkb(struct dlm_ls *ls, struct dlm_lkb *lkb)
e7fd4179 622{
e7fd4179
DT		 623 uint16_t bucket = lkb->lkb_id & 0xFFFF;
624
625 write_lock(&ls->ls_lkbtbl[bucket].lock);
626 if (kref_put(&lkb->lkb_ref, kill_lkb)) {
627 list_del(&lkb->lkb_idtbl_list);
628 write_unlock(&ls->ls_lkbtbl[bucket].lock);
629
630 detach_lkb(lkb);
631
632 /* for local/process lkbs, lvbptr points to caller's lksb */
633 if (lkb->lkb_lvbptr && is_master_copy(lkb))
634 free_lvb(lkb->lkb_lvbptr);
e7fd4179
DT		 635 free_lkb(lkb);
636 return 1;
637 } else {
638 write_unlock(&ls->ls_lkbtbl[bucket].lock);
639 return 0;
640 }
641}
642
643int dlm_put_lkb(struct dlm_lkb *lkb)
644{
b3f58d8f
DT		 645 struct dlm_ls *ls;
646
647 DLM_ASSERT(lkb->lkb_resource, dlm_print_lkb(lkb););
648 DLM_ASSERT(lkb->lkb_resource->res_ls, dlm_print_lkb(lkb););
649
650 ls = lkb->lkb_resource->res_ls;
651 return __put_lkb(ls, lkb);
e7fd4179
DT		 652}
653
654/* This is only called to add a reference when the code already holds
655 a valid reference to the lkb, so there's no need for locking. */
656
657static inline void hold_lkb(struct dlm_lkb *lkb)
658{
659 kref_get(&lkb->lkb_ref);
660}
661
662/* This is called when we need to remove a reference and are certain
663 it's not the last ref. e.g. del_lkb is always called between a
664 find_lkb/put_lkb and is always the inverse of a previous add_lkb.
665 put_lkb would work fine, but would involve unnecessary locking */
666
667static inline void unhold_lkb(struct dlm_lkb *lkb)
668{
669 int rv;
670 rv = kref_put(&lkb->lkb_ref, kill_lkb);
671 DLM_ASSERT(!rv, dlm_print_lkb(lkb););
672}
673
674static void lkb_add_ordered(struct list_head *new, struct list_head *head,
675 int mode)
676{
677 struct dlm_lkb *lkb = NULL;
678
679 list_for_each_entry(lkb, head, lkb_statequeue)
680 if (lkb->lkb_rqmode < mode)
681 break;
682
683 if (!lkb)
684 list_add_tail(new, head);
685 else
686 __list_add(new, lkb->lkb_statequeue.prev, &lkb->lkb_statequeue);
687}
688
689/* add/remove lkb to rsb's grant/convert/wait queue */
690
691static void add_lkb(struct dlm_rsb *r, struct dlm_lkb *lkb, int status)
692{
693 kref_get(&lkb->lkb_ref);
694
695 DLM_ASSERT(!lkb->lkb_status, dlm_print_lkb(lkb););
696
697 lkb->lkb_status = status;
698
699 switch (status) {
700 case DLM_LKSTS_WAITING:
701 if (lkb->lkb_exflags & DLM_LKF_HEADQUE)
702 list_add(&lkb->lkb_statequeue, &r->res_waitqueue);
703 else
704 list_add_tail(&lkb->lkb_statequeue, &r->res_waitqueue);
705 break;
706 case DLM_LKSTS_GRANTED:
707 /* convention says granted locks kept in order of grmode */
708 lkb_add_ordered(&lkb->lkb_statequeue, &r->res_grantqueue,
709 lkb->lkb_grmode);
710 break;
711 case DLM_LKSTS_CONVERT:
712 if (lkb->lkb_exflags & DLM_LKF_HEADQUE)
713 list_add(&lkb->lkb_statequeue, &r->res_convertqueue);
714 else
715 list_add_tail(&lkb->lkb_statequeue,
716 &r->res_convertqueue);
717 break;
718 default:
719 DLM_ASSERT(0, dlm_print_lkb(lkb); printk("sts=%d\n", status););
720 }
721}
722
723static void del_lkb(struct dlm_rsb *r, struct dlm_lkb *lkb)
724{
725 lkb->lkb_status = 0;
726 list_del(&lkb->lkb_statequeue);
727 unhold_lkb(lkb);
728}
729
730static void move_lkb(struct dlm_rsb *r, struct dlm_lkb *lkb, int sts)
731{
732 hold_lkb(lkb);
733 del_lkb(r, lkb);
734 add_lkb(r, lkb, sts);
735 unhold_lkb(lkb);
736}
737
738/* add/remove lkb from global waiters list of lkb's waiting for
739 a reply from a remote node */
740
741static void add_to_waiters(struct dlm_lkb *lkb, int mstype)
742{
743 struct dlm_ls *ls = lkb->lkb_resource->res_ls;
744
90135925 745 mutex_lock(&ls->ls_waiters_mutex);
e7fd4179
DT		 746 if (lkb->lkb_wait_type) {
747 log_print("add_to_waiters error %d", lkb->lkb_wait_type);
748 goto out;
749 }
750 lkb->lkb_wait_type = mstype;
751 kref_get(&lkb->lkb_ref);
752 list_add(&lkb->lkb_wait_reply, &ls->ls_waiters);
753 out:
90135925 754 mutex_unlock(&ls->ls_waiters_mutex);
e7fd4179
DT		 755}
756
757static int _remove_from_waiters(struct dlm_lkb *lkb)
758{
759 int error = 0;
760
761 if (!lkb->lkb_wait_type) {
762 log_print("remove_from_waiters error");
763 error = -EINVAL;
764 goto out;
765 }
766 lkb->lkb_wait_type = 0;
767 list_del(&lkb->lkb_wait_reply);
768 unhold_lkb(lkb);
769 out:
770 return error;
771}
772
773static int remove_from_waiters(struct dlm_lkb *lkb)
774{
775 struct dlm_ls *ls = lkb->lkb_resource->res_ls;
776 int error;
777
90135925 778 mutex_lock(&ls->ls_waiters_mutex);
e7fd4179 779 error = _remove_from_waiters(lkb);
90135925 780 mutex_unlock(&ls->ls_waiters_mutex);
e7fd4179
DT		 781 return error;
782}
783
784static void dir_remove(struct dlm_rsb *r)
785{
786 int to_nodeid;
787
788 if (dlm_no_directory(r->res_ls))
789 return;
790
791 to_nodeid = dlm_dir_nodeid(r);
792 if (to_nodeid != dlm_our_nodeid())
793 send_remove(r);
794 else
795 dlm_dir_remove_entry(r->res_ls, to_nodeid,
796 r->res_name, r->res_length);
797}
798
799/* FIXME: shouldn't this be able to exit as soon as one non-due rsb is
800 found since they are in order of newest to oldest? */
801
802static int shrink_bucket(struct dlm_ls *ls, int b)
803{
804 struct dlm_rsb *r;
805 int count = 0, found;
806
807 for (;;) {
90135925 808 found = 0;
e7fd4179
DT		 809 write_lock(&ls->ls_rsbtbl[b].lock);
810 list_for_each_entry_reverse(r, &ls->ls_rsbtbl[b].toss,
811 res_hashchain) {
812 if (!time_after_eq(jiffies, r->res_toss_time +
68c817a1 813 dlm_config.ci_toss_secs * HZ))
e7fd4179 814 continue;
90135925 815 found = 1;
e7fd4179
DT		 816 break;
817 }
818
819 if (!found) {
820 write_unlock(&ls->ls_rsbtbl[b].lock);
821 break;
822 }
823
824 if (kref_put(&r->res_ref, kill_rsb)) {
825 list_del(&r->res_hashchain);
826 write_unlock(&ls->ls_rsbtbl[b].lock);
827
828 if (is_master(r))
829 dir_remove(r);
830 free_rsb(r);
831 count++;
832 } else {
833 write_unlock(&ls->ls_rsbtbl[b].lock);
834 log_error(ls, "tossed rsb in use %s", r->res_name);
835 }
836 }
837
838 return count;
839}
840
841void dlm_scan_rsbs(struct dlm_ls *ls)
842{
843 int i;
844
845 if (dlm_locking_stopped(ls))
846 return;
847
848 for (i = 0; i < ls->ls_rsbtbl_size; i++) {
849 shrink_bucket(ls, i);
850 cond_resched();
851 }
852}
853
854/* lkb is master or local copy */
855
856static void set_lvb_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
857{
858 int b, len = r->res_ls->ls_lvblen;
859
860 /* b=1 lvb returned to caller
861 b=0 lvb written to rsb or invalidated
862 b=-1 do nothing */
863
864 b = dlm_lvb_operations[lkb->lkb_grmode + 1][lkb->lkb_rqmode + 1];
865
866 if (b == 1) {
867 if (!lkb->lkb_lvbptr)
868 return;
869
870 if (!(lkb->lkb_exflags & DLM_LKF_VALBLK))
871 return;
872
873 if (!r->res_lvbptr)
874 return;
875
876 memcpy(lkb->lkb_lvbptr, r->res_lvbptr, len);
877 lkb->lkb_lvbseq = r->res_lvbseq;
878
879 } else if (b == 0) {
880 if (lkb->lkb_exflags & DLM_LKF_IVVALBLK) {
881 rsb_set_flag(r, RSB_VALNOTVALID);
882 return;
883 }
884
885 if (!lkb->lkb_lvbptr)
886 return;
887
888 if (!(lkb->lkb_exflags & DLM_LKF_VALBLK))
889 return;
890
891 if (!r->res_lvbptr)
892 r->res_lvbptr = allocate_lvb(r->res_ls);
893
894 if (!r->res_lvbptr)
895 return;
896
897 memcpy(r->res_lvbptr, lkb->lkb_lvbptr, len);
898 r->res_lvbseq++;
899 lkb->lkb_lvbseq = r->res_lvbseq;
900 rsb_clear_flag(r, RSB_VALNOTVALID);
901 }
902
903 if (rsb_flag(r, RSB_VALNOTVALID))
904 lkb->lkb_sbflags |= DLM_SBF_VALNOTVALID;
905}
906
907static void set_lvb_unlock(struct dlm_rsb *r, struct dlm_lkb *lkb)
908{
909 if (lkb->lkb_grmode < DLM_LOCK_PW)
910 return;
911
912 if (lkb->lkb_exflags & DLM_LKF_IVVALBLK) {
913 rsb_set_flag(r, RSB_VALNOTVALID);
914 return;
915 }
916
917 if (!lkb->lkb_lvbptr)
918 return;
919
920 if (!(lkb->lkb_exflags & DLM_LKF_VALBLK))
921 return;
922
923 if (!r->res_lvbptr)
924 r->res_lvbptr = allocate_lvb(r->res_ls);
925
926 if (!r->res_lvbptr)
927 return;
928
929 memcpy(r->res_lvbptr, lkb->lkb_lvbptr, r->res_ls->ls_lvblen);
930 r->res_lvbseq++;
931 rsb_clear_flag(r, RSB_VALNOTVALID);
932}
933
934/* lkb is process copy (pc) */
935
936static void set_lvb_lock_pc(struct dlm_rsb *r, struct dlm_lkb *lkb,
937 struct dlm_message *ms)
938{
939 int b;
940
941 if (!lkb->lkb_lvbptr)
942 return;
943
944 if (!(lkb->lkb_exflags & DLM_LKF_VALBLK))
945 return;
946
597d0cae 947 b = dlm_lvb_operations[lkb->lkb_grmode + 1][lkb->lkb_rqmode + 1];
e7fd4179
DT		 948 if (b == 1) {
949 int len = receive_extralen(ms);
950 memcpy(lkb->lkb_lvbptr, ms->m_extra, len);
951 lkb->lkb_lvbseq = ms->m_lvbseq;
952 }
953}
954
955/* Manipulate lkb's on rsb's convert/granted/waiting queues
956 remove_lock -- used for unlock, removes lkb from granted
957 revert_lock -- used for cancel, moves lkb from convert to granted
958 grant_lock -- used for request and convert, adds lkb to granted or
959 moves lkb from convert or waiting to granted
960
961 Each of these is used for master or local copy lkb's. There is
962 also a _pc() variation used to make the corresponding change on
963 a process copy (pc) lkb. */
964
965static void _remove_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
966{
967 del_lkb(r, lkb);
968 lkb->lkb_grmode = DLM_LOCK_IV;
969 /* this unhold undoes the original ref from create_lkb()
970 so this leads to the lkb being freed */
971 unhold_lkb(lkb);
972}
973
974static void remove_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
975{
976 set_lvb_unlock(r, lkb);
977 _remove_lock(r, lkb);
978}
979
980static void remove_lock_pc(struct dlm_rsb *r, struct dlm_lkb *lkb)
981{
982 _remove_lock(r, lkb);
983}
984
985static void revert_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
986{
987 lkb->lkb_rqmode = DLM_LOCK_IV;
988
989 switch (lkb->lkb_status) {
597d0cae
DT		 990 case DLM_LKSTS_GRANTED:
991 break;
e7fd4179
DT		 992 case DLM_LKSTS_CONVERT:
993 move_lkb(r, lkb, DLM_LKSTS_GRANTED);
994 break;
995 case DLM_LKSTS_WAITING:
996 del_lkb(r, lkb);
997 lkb->lkb_grmode = DLM_LOCK_IV;
998 /* this unhold undoes the original ref from create_lkb()
999 so this leads to the lkb being freed */
1000 unhold_lkb(lkb);
1001 break;
1002 default:
1003 log_print("invalid status for revert %d", lkb->lkb_status);
1004 }
1005}
1006
1007static void revert_lock_pc(struct dlm_rsb *r, struct dlm_lkb *lkb)
1008{
1009 revert_lock(r, lkb);
1010}
1011
1012static void _grant_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
1013{
1014 if (lkb->lkb_grmode != lkb->lkb_rqmode) {
1015 lkb->lkb_grmode = lkb->lkb_rqmode;
1016 if (lkb->lkb_status)
1017 move_lkb(r, lkb, DLM_LKSTS_GRANTED);
1018 else
1019 add_lkb(r, lkb, DLM_LKSTS_GRANTED);
1020 }
1021
1022 lkb->lkb_rqmode = DLM_LOCK_IV;
e7fd4179
DT		 1023}
1024
1025static void grant_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
1026{
1027 set_lvb_lock(r, lkb);
1028 _grant_lock(r, lkb);
1029 lkb->lkb_highbast = 0;
1030}
1031
1032static void grant_lock_pc(struct dlm_rsb *r, struct dlm_lkb *lkb,
1033 struct dlm_message *ms)
1034{
1035 set_lvb_lock_pc(r, lkb, ms);
1036 _grant_lock(r, lkb);
1037}
1038
1039/* called by grant_pending_locks() which means an async grant message must
1040 be sent to the requesting node in addition to granting the lock if the
1041 lkb belongs to a remote node. */
1042
1043static void grant_lock_pending(struct dlm_rsb *r, struct dlm_lkb *lkb)
1044{
1045 grant_lock(r, lkb);
1046 if (is_master_copy(lkb))
1047 send_grant(r, lkb);
1048 else
1049 queue_cast(r, lkb, 0);
1050}
1051
1052static inline int first_in_list(struct dlm_lkb *lkb, struct list_head *head)
1053{
1054 struct dlm_lkb *first = list_entry(head->next, struct dlm_lkb,
1055 lkb_statequeue);
1056 if (lkb->lkb_id == first->lkb_id)
90135925 1057 return 1;
e7fd4179 1058
90135925 1059 return 0;
e7fd4179
DT		 1060}
1061
e7fd4179
DT		 1062/* Check if the given lkb conflicts with another lkb on the queue. */
1063
1064static int queue_conflict(struct list_head *head, struct dlm_lkb *lkb)
1065{
1066 struct dlm_lkb *this;
1067
1068 list_for_each_entry(this, head, lkb_statequeue) {
1069 if (this == lkb)
1070 continue;
3bcd3687 1071 if (!modes_compat(this, lkb))
90135925 1072 return 1;
e7fd4179 1073 }
90135925 1074 return 0;
e7fd4179
DT		 1075}
1076
1077/*
1078 * "A conversion deadlock arises with a pair of lock requests in the converting
1079 * queue for one resource. The granted mode of each lock blocks the requested
1080 * mode of the other lock."
1081 *
1082 * Part 2: if the granted mode of lkb is preventing the first lkb in the
1083 * convert queue from being granted, then demote lkb (set grmode to NL).
1084 * This second form requires that we check for conv-deadlk even when
1085 * now == 0 in _can_be_granted().
1086 *
1087 * Example:
1088 * Granted Queue: empty
1089 * Convert Queue: NL->EX (first lock)
1090 * PR->EX (second lock)
1091 *
1092 * The first lock can't be granted because of the granted mode of the second
1093 * lock and the second lock can't be granted because it's not first in the
1094 * list. We demote the granted mode of the second lock (the lkb passed to this
1095 * function).
1096 *
1097 * After the resolution, the "grant pending" function needs to go back and try
1098 * to grant locks on the convert queue again since the first lock can now be
1099 * granted.
1100 */
1101
1102static int conversion_deadlock_detect(struct dlm_rsb *rsb, struct dlm_lkb *lkb)
1103{
1104 struct dlm_lkb *this, *first = NULL, *self = NULL;
1105
1106 list_for_each_entry(this, &rsb->res_convertqueue, lkb_statequeue) {
1107 if (!first)
1108 first = this;
1109 if (this == lkb) {
1110 self = lkb;
1111 continue;
1112 }
1113
e7fd4179 1114 if (!modes_compat(this, lkb) && !modes_compat(lkb, this))
90135925 1115 return 1;
e7fd4179
DT		 1116 }
1117
1118 /* if lkb is on the convert queue and is preventing the first
1119 from being granted, then there's deadlock and we demote lkb.
1120 multiple converting locks may need to do this before the first
1121 converting lock can be granted. */
1122
1123 if (self && self != first) {
1124 if (!modes_compat(lkb, first) &&
1125 !queue_conflict(&rsb->res_grantqueue, first))
90135925 1126 return 1;
e7fd4179
DT		 1127 }
1128
90135925 1129 return 0;
e7fd4179
DT		 1130}
1131
1132/*
1133 * Return 1 if the lock can be granted, 0 otherwise.
1134 * Also detect and resolve conversion deadlocks.
1135 *
1136 * lkb is the lock to be granted
1137 *
1138 * now is 1 if the function is being called in the context of the
1139 * immediate request, it is 0 if called later, after the lock has been
1140 * queued.
1141 *
1142 * References are from chapter 6 of "VAXcluster Principles" by Roy Davis
1143 */
1144
1145static int _can_be_granted(struct dlm_rsb *r, struct dlm_lkb *lkb, int now)
1146{
1147 int8_t conv = (lkb->lkb_grmode != DLM_LOCK_IV);
1148
1149 /*
1150 * 6-10: Version 5.4 introduced an option to address the phenomenon of
1151 * a new request for a NL mode lock being blocked.
1152 *
1153 * 6-11: If the optional EXPEDITE flag is used with the new NL mode
1154 * request, then it would be granted. In essence, the use of this flag
1155 * tells the Lock Manager to expedite theis request by not considering
1156 * what may be in the CONVERTING or WAITING queues... As of this
1157 * writing, the EXPEDITE flag can be used only with new requests for NL
1158 * mode locks. This flag is not valid for conversion requests.
1159 *
1160 * A shortcut. Earlier checks return an error if EXPEDITE is used in a
1161 * conversion or used with a non-NL requested mode. We also know an
1162 * EXPEDITE request is always granted immediately, so now must always
1163 * be 1. The full condition to grant an expedite request: (now &&
1164 * !conv && lkb->rqmode == DLM_LOCK_NL && (flags & EXPEDITE)) can
1165 * therefore be shortened to just checking the flag.
1166 */
1167
1168 if (lkb->lkb_exflags & DLM_LKF_EXPEDITE)
90135925 1169 return 1;
e7fd4179
DT		 1170
1171 /*
1172 * A shortcut. Without this, !queue_conflict(grantqueue, lkb) would be
1173 * added to the remaining conditions.
1174 */
1175
1176 if (queue_conflict(&r->res_grantqueue, lkb))
1177 goto out;
1178
1179 /*
1180 * 6-3: By default, a conversion request is immediately granted if the
1181 * requested mode is compatible with the modes of all other granted
1182 * locks
1183 */
1184
1185 if (queue_conflict(&r->res_convertqueue, lkb))
1186 goto out;
1187
1188 /*
1189 * 6-5: But the default algorithm for deciding whether to grant or
1190 * queue conversion requests does not by itself guarantee that such
1191 * requests are serviced on a "first come first serve" basis. This, in
1192 * turn, can lead to a phenomenon known as "indefinate postponement".
1193 *
1194 * 6-7: This issue is dealt with by using the optional QUECVT flag with
1195 * the system service employed to request a lock conversion. This flag
1196 * forces certain conversion requests to be queued, even if they are
1197 * compatible with the granted modes of other locks on the same
1198 * resource. Thus, the use of this flag results in conversion requests
1199 * being ordered on a "first come first servce" basis.
1200 *
1201 * DCT: This condition is all about new conversions being able to occur
1202 * "in place" while the lock remains on the granted queue (assuming
1203 * nothing else conflicts.) IOW if QUECVT isn't set, a conversion
1204 * doesn't _have_ to go onto the convert queue where it's processed in
1205 * order. The "now" variable is necessary to distinguish converts
1206 * being received and processed for the first time now, because once a
1207 * convert is moved to the conversion queue the condition below applies
1208 * requiring fifo granting.
1209 */
1210
1211 if (now && conv && !(lkb->lkb_exflags & DLM_LKF_QUECVT))
90135925 1212 return 1;
e7fd4179
DT		 1213
1214 /*
3bcd3687
DT		 1215 * The NOORDER flag is set to avoid the standard vms rules on grant
1216 * order.
e7fd4179
DT		 1217 */
1218
1219 if (lkb->lkb_exflags & DLM_LKF_NOORDER)
90135925 1220 return 1;
e7fd4179
DT		 1221
1222 /*
1223 * 6-3: Once in that queue [CONVERTING], a conversion request cannot be
1224 * granted until all other conversion requests ahead of it are granted
1225 * and/or canceled.
1226 */
1227
1228 if (!now && conv && first_in_list(lkb, &r->res_convertqueue))
90135925 1229 return 1;
e7fd4179
DT		 1230
1231 /*
1232 * 6-4: By default, a new request is immediately granted only if all
1233 * three of the following conditions are satisfied when the request is
1234 * issued:
1235 * - The queue of ungranted conversion requests for the resource is
1236 * empty.
1237 * - The queue of ungranted new requests for the resource is empty.
1238 * - The mode of the new request is compatible with the most
1239 * restrictive mode of all granted locks on the resource.
1240 */
1241
1242 if (now && !conv && list_empty(&r->res_convertqueue) &&
1243 list_empty(&r->res_waitqueue))
90135925 1244 return 1;
e7fd4179
DT		 1245
1246 /*
1247 * 6-4: Once a lock request is in the queue of ungranted new requests,
1248 * it cannot be granted until the queue of ungranted conversion
1249 * requests is empty, all ungranted new requests ahead of it are
1250 * granted and/or canceled, and it is compatible with the granted mode
1251 * of the most restrictive lock granted on the resource.
1252 */
1253
1254 if (!now && !conv && list_empty(&r->res_convertqueue) &&
1255 first_in_list(lkb, &r->res_waitqueue))
90135925 1256 return 1;
e7fd4179
DT		 1257
1258 out:
1259 /*
1260 * The following, enabled by CONVDEADLK, departs from VMS.
1261 */
1262
1263 if (conv && (lkb->lkb_exflags & DLM_LKF_CONVDEADLK) &&
1264 conversion_deadlock_detect(r, lkb)) {
1265 lkb->lkb_grmode = DLM_LOCK_NL;
1266 lkb->lkb_sbflags |= DLM_SBF_DEMOTED;
1267 }
1268
90135925 1269 return 0;
e7fd4179
DT		 1270}
1271
1272/*
1273 * The ALTPR and ALTCW flags aren't traditional lock manager flags, but are a
1274 * simple way to provide a big optimization to applications that can use them.
1275 */
1276
1277static int can_be_granted(struct dlm_rsb *r, struct dlm_lkb *lkb, int now)
1278{
1279 uint32_t flags = lkb->lkb_exflags;
1280 int rv;
1281 int8_t alt = 0, rqmode = lkb->lkb_rqmode;
1282
1283 rv = _can_be_granted(r, lkb, now);
1284 if (rv)
1285 goto out;
1286
1287 if (lkb->lkb_sbflags & DLM_SBF_DEMOTED)
1288 goto out;
1289
1290 if (rqmode != DLM_LOCK_PR && flags & DLM_LKF_ALTPR)
1291 alt = DLM_LOCK_PR;
1292 else if (rqmode != DLM_LOCK_CW && flags & DLM_LKF_ALTCW)
1293 alt = DLM_LOCK_CW;
1294
1295 if (alt) {
1296 lkb->lkb_rqmode = alt;
1297 rv = _can_be_granted(r, lkb, now);
1298 if (rv)
1299 lkb->lkb_sbflags |= DLM_SBF_ALTMODE;
1300 else
1301 lkb->lkb_rqmode = rqmode;
1302 }
1303 out:
1304 return rv;
1305}
1306
1307static int grant_pending_convert(struct dlm_rsb *r, int high)
1308{
1309 struct dlm_lkb *lkb, *s;
1310 int hi, demoted, quit, grant_restart, demote_restart;
1311
1312 quit = 0;
1313 restart:
1314 grant_restart = 0;
1315 demote_restart = 0;
1316 hi = DLM_LOCK_IV;
1317
1318 list_for_each_entry_safe(lkb, s, &r->res_convertqueue, lkb_statequeue) {
1319 demoted = is_demoted(lkb);
90135925 1320 if (can_be_granted(r, lkb, 0)) {
e7fd4179
DT		 1321 grant_lock_pending(r, lkb);
1322 grant_restart = 1;
1323 } else {
1324 hi = max_t(int, lkb->lkb_rqmode, hi);
1325 if (!demoted && is_demoted(lkb))
1326 demote_restart = 1;
1327 }
1328 }
1329
1330 if (grant_restart)
1331 goto restart;
1332 if (demote_restart && !quit) {
1333 quit = 1;
1334 goto restart;
1335 }
1336
1337 return max_t(int, high, hi);
1338}
1339
1340static int grant_pending_wait(struct dlm_rsb *r, int high)
1341{
1342 struct dlm_lkb *lkb, *s;
1343
1344 list_for_each_entry_safe(lkb, s, &r->res_waitqueue, lkb_statequeue) {
90135925 1345 if (can_be_granted(r, lkb, 0))
e7fd4179
DT		 1346 grant_lock_pending(r, lkb);
1347 else
1348 high = max_t(int, lkb->lkb_rqmode, high);
1349 }
1350
1351 return high;
1352}
1353
1354static void grant_pending_locks(struct dlm_rsb *r)
1355{
1356 struct dlm_lkb *lkb, *s;
1357 int high = DLM_LOCK_IV;
1358
a345da3e 1359 DLM_ASSERT(is_master(r), dlm_dump_rsb(r););
e7fd4179
DT		 1360
1361 high = grant_pending_convert(r, high);
1362 high = grant_pending_wait(r, high);
1363
1364 if (high == DLM_LOCK_IV)
1365 return;
1366
1367 /*
1368 * If there are locks left on the wait/convert queue then send blocking
1369 * ASTs to granted locks based on the largest requested mode (high)
3bcd3687 1370 * found above. FIXME: highbast < high comparison not valid for PR/CW.
e7fd4179
DT		 1371 */
1372
1373 list_for_each_entry_safe(lkb, s, &r->res_grantqueue, lkb_statequeue) {
1374 if (lkb->lkb_bastaddr && (lkb->lkb_highbast < high) &&
1375 !__dlm_compat_matrix[lkb->lkb_grmode+1][high+1]) {
1376 queue_bast(r, lkb, high);
1377 lkb->lkb_highbast = high;
1378 }
1379 }
1380}
1381
1382static void send_bast_queue(struct dlm_rsb *r, struct list_head *head,
1383 struct dlm_lkb *lkb)
1384{
1385 struct dlm_lkb *gr;
1386
1387 list_for_each_entry(gr, head, lkb_statequeue) {
1388 if (gr->lkb_bastaddr &&
1389 gr->lkb_highbast < lkb->lkb_rqmode &&
3bcd3687 1390 !modes_compat(gr, lkb)) {
e7fd4179
DT		 1391 queue_bast(r, gr, lkb->lkb_rqmode);
1392 gr->lkb_highbast = lkb->lkb_rqmode;
1393 }
1394 }
1395}
1396
1397static void send_blocking_asts(struct dlm_rsb *r, struct dlm_lkb *lkb)
1398{
1399 send_bast_queue(r, &r->res_grantqueue, lkb);
1400}
1401
1402static void send_blocking_asts_all(struct dlm_rsb *r, struct dlm_lkb *lkb)
1403{
1404 send_bast_queue(r, &r->res_grantqueue, lkb);
1405 send_bast_queue(r, &r->res_convertqueue, lkb);
1406}
1407
1408/* set_master(r, lkb) -- set the master nodeid of a resource
1409
1410 The purpose of this function is to set the nodeid field in the given
1411 lkb using the nodeid field in the given rsb. If the rsb's nodeid is
1412 known, it can just be copied to the lkb and the function will return
1413 0. If the rsb's nodeid is _not_ known, it needs to be looked up
1414 before it can be copied to the lkb.
1415
1416 When the rsb nodeid is being looked up remotely, the initial lkb
1417 causing the lookup is kept on the ls_waiters list waiting for the
1418 lookup reply. Other lkb's waiting for the same rsb lookup are kept
1419 on the rsb's res_lookup list until the master is verified.
1420
1421 Return values:
1422 0: nodeid is set in rsb/lkb and the caller should go ahead and use it
1423 1: the rsb master is not available and the lkb has been placed on
1424 a wait queue
1425*/
1426
1427static int set_master(struct dlm_rsb *r, struct dlm_lkb *lkb)
1428{
1429 struct dlm_ls *ls = r->res_ls;
1430 int error, dir_nodeid, ret_nodeid, our_nodeid = dlm_our_nodeid();
1431
1432 if (rsb_flag(r, RSB_MASTER_UNCERTAIN)) {
1433 rsb_clear_flag(r, RSB_MASTER_UNCERTAIN);
1434 r->res_first_lkid = lkb->lkb_id;
1435 lkb->lkb_nodeid = r->res_nodeid;
1436 return 0;
1437 }
1438
1439 if (r->res_first_lkid && r->res_first_lkid != lkb->lkb_id) {
1440 list_add_tail(&lkb->lkb_rsb_lookup, &r->res_lookup);
1441 return 1;
1442 }
1443
1444 if (r->res_nodeid == 0) {
1445 lkb->lkb_nodeid = 0;
1446 return 0;
1447 }
1448
1449 if (r->res_nodeid > 0) {
1450 lkb->lkb_nodeid = r->res_nodeid;
1451 return 0;
1452 }
1453
a345da3e 1454 DLM_ASSERT(r->res_nodeid == -1, dlm_dump_rsb(r););
e7fd4179
DT		 1455
1456 dir_nodeid = dlm_dir_nodeid(r);
1457
1458 if (dir_nodeid != our_nodeid) {
1459 r->res_first_lkid = lkb->lkb_id;
1460 send_lookup(r, lkb);
1461 return 1;
1462 }
1463
1464 for (;;) {
1465 /* It's possible for dlm_scand to remove an old rsb for
1466 this same resource from the toss list, us to create
1467 a new one, look up the master locally, and find it
1468 already exists just before dlm_scand does the
1469 dir_remove() on the previous rsb. */
1470
1471 error = dlm_dir_lookup(ls, our_nodeid, r->res_name,
1472 r->res_length, &ret_nodeid);
1473 if (!error)
1474 break;
1475 log_debug(ls, "dir_lookup error %d %s", error, r->res_name);
1476 schedule();
1477 }
1478
1479 if (ret_nodeid == our_nodeid) {
1480 r->res_first_lkid = 0;
1481 r->res_nodeid = 0;
1482 lkb->lkb_nodeid = 0;
1483 } else {
1484 r->res_first_lkid = lkb->lkb_id;
1485 r->res_nodeid = ret_nodeid;
1486 lkb->lkb_nodeid = ret_nodeid;
1487 }
1488 return 0;
1489}
1490
1491static void process_lookup_list(struct dlm_rsb *r)
1492{
1493 struct dlm_lkb *lkb, *safe;
1494
1495 list_for_each_entry_safe(lkb, safe, &r->res_lookup, lkb_rsb_lookup) {
1496 list_del(&lkb->lkb_rsb_lookup);
1497 _request_lock(r, lkb);
1498 schedule();
1499 }
1500}
1501
1502/* confirm_master -- confirm (or deny) an rsb's master nodeid */
1503
1504static void confirm_master(struct dlm_rsb *r, int error)
1505{
1506 struct dlm_lkb *lkb;
1507
1508 if (!r->res_first_lkid)
1509 return;
1510
1511 switch (error) {
1512 case 0:
1513 case -EINPROGRESS:
1514 r->res_first_lkid = 0;
1515 process_lookup_list(r);
1516 break;
1517
1518 case -EAGAIN:
1519 /* the remote master didn't queue our NOQUEUE request;
1520 make a waiting lkb the first_lkid */
1521
1522 r->res_first_lkid = 0;
1523
1524 if (!list_empty(&r->res_lookup)) {
1525 lkb = list_entry(r->res_lookup.next, struct dlm_lkb,
1526 lkb_rsb_lookup);
1527 list_del(&lkb->lkb_rsb_lookup);
1528 r->res_first_lkid = lkb->lkb_id;
1529 _request_lock(r, lkb);
1530 } else
1531 r->res_nodeid = -1;
1532 break;
1533
1534 default:
1535 log_error(r->res_ls, "confirm_master unknown error %d", error);
1536 }
1537}
1538
1539static int set_lock_args(int mode, struct dlm_lksb *lksb, uint32_t flags,
1540 int namelen, uint32_t parent_lkid, void *ast,
3bcd3687 1541 void *astarg, void *bast, struct dlm_args *args)
e7fd4179
DT		 1542{
1543 int rv = -EINVAL;
1544
1545 /* check for invalid arg usage */
1546
1547 if (mode < 0 || mode > DLM_LOCK_EX)
1548 goto out;
1549
1550 if (!(flags & DLM_LKF_CONVERT) && (namelen > DLM_RESNAME_MAXLEN))
1551 goto out;
1552
1553 if (flags & DLM_LKF_CANCEL)
1554 goto out;
1555
1556 if (flags & DLM_LKF_QUECVT && !(flags & DLM_LKF_CONVERT))
1557 goto out;
1558
1559 if (flags & DLM_LKF_CONVDEADLK && !(flags & DLM_LKF_CONVERT))
1560 goto out;
1561
1562 if (flags & DLM_LKF_CONVDEADLK && flags & DLM_LKF_NOQUEUE)
1563 goto out;
1564
1565 if (flags & DLM_LKF_EXPEDITE && flags & DLM_LKF_CONVERT)
1566 goto out;
1567
1568 if (flags & DLM_LKF_EXPEDITE && flags & DLM_LKF_QUECVT)
1569 goto out;
1570
1571 if (flags & DLM_LKF_EXPEDITE && flags & DLM_LKF_NOQUEUE)
1572 goto out;
1573
1574 if (flags & DLM_LKF_EXPEDITE && mode != DLM_LOCK_NL)
1575 goto out;
1576
1577 if (!ast || !lksb)
1578 goto out;
1579
1580 if (flags & DLM_LKF_VALBLK && !lksb->sb_lvbptr)
1581 goto out;
1582
1583 /* parent/child locks not yet supported */
1584 if (parent_lkid)
1585 goto out;
1586
1587 if (flags & DLM_LKF_CONVERT && !lksb->sb_lkid)
1588 goto out;
1589
1590 /* these args will be copied to the lkb in validate_lock_args,
1591 it cannot be done now because when converting locks, fields in
1592 an active lkb cannot be modified before locking the rsb */
1593
1594 args->flags = flags;
1595 args->astaddr = ast;
1596 args->astparam = (long) astarg;
1597 args->bastaddr = bast;
1598 args->mode = mode;
1599 args->lksb = lksb;
e7fd4179
DT		 1600 rv = 0;
1601 out:
1602 return rv;
1603}
1604
1605static int set_unlock_args(uint32_t flags, void *astarg, struct dlm_args *args)
1606{
1607 if (flags & ~(DLM_LKF_CANCEL | DLM_LKF_VALBLK | DLM_LKF_IVVALBLK |
1608 DLM_LKF_FORCEUNLOCK))
1609 return -EINVAL;
1610
1611 args->flags = flags;
1612 args->astparam = (long) astarg;
1613 return 0;
1614}
1615
1616static int validate_lock_args(struct dlm_ls *ls, struct dlm_lkb *lkb,
1617 struct dlm_args *args)
1618{
1619 int rv = -EINVAL;
1620
1621 if (args->flags & DLM_LKF_CONVERT) {
1622 if (lkb->lkb_flags & DLM_IFL_MSTCPY)
1623 goto out;
1624
1625 if (args->flags & DLM_LKF_QUECVT &&
1626 !__quecvt_compat_matrix[lkb->lkb_grmode+1][args->mode+1])
1627 goto out;
1628
1629 rv = -EBUSY;
1630 if (lkb->lkb_status != DLM_LKSTS_GRANTED)
1631 goto out;
1632
1633 if (lkb->lkb_wait_type)
1634 goto out;
1635 }
1636
1637 lkb->lkb_exflags = args->flags;
1638 lkb->lkb_sbflags = 0;
1639 lkb->lkb_astaddr = args->astaddr;
1640 lkb->lkb_astparam = args->astparam;
1641 lkb->lkb_bastaddr = args->bastaddr;
1642 lkb->lkb_rqmode = args->mode;
1643 lkb->lkb_lksb = args->lksb;
1644 lkb->lkb_lvbptr = args->lksb->sb_lvbptr;
1645 lkb->lkb_ownpid = (int) current->pid;
e7fd4179
DT		 1646 rv = 0;
1647 out:
1648 return rv;
1649}
1650
1651static int validate_unlock_args(struct dlm_lkb *lkb, struct dlm_args *args)
1652{
1653 int rv = -EINVAL;
1654
1655 if (lkb->lkb_flags & DLM_IFL_MSTCPY)
1656 goto out;
1657
1658 if (args->flags & DLM_LKF_FORCEUNLOCK)
1659 goto out_ok;
1660
1661 if (args->flags & DLM_LKF_CANCEL &&
1662 lkb->lkb_status == DLM_LKSTS_GRANTED)
1663 goto out;
1664
1665 if (!(args->flags & DLM_LKF_CANCEL) &&
1666 lkb->lkb_status != DLM_LKSTS_GRANTED)
1667 goto out;
1668
1669 rv = -EBUSY;
1670 if (lkb->lkb_wait_type)
1671 goto out;
1672
1673 out_ok:
1674 lkb->lkb_exflags = args->flags;
1675 lkb->lkb_sbflags = 0;
1676 lkb->lkb_astparam = args->astparam;
1677
1678 rv = 0;
1679 out:
1680 return rv;
1681}
1682
1683/*
1684 * Four stage 4 varieties:
1685 * do_request(), do_convert(), do_unlock(), do_cancel()
1686 * These are called on the master node for the given lock and
1687 * from the central locking logic.
1688 */
1689
1690static int do_request(struct dlm_rsb *r, struct dlm_lkb *lkb)
1691{
1692 int error = 0;
1693
90135925 1694 if (can_be_granted(r, lkb, 1)) {
e7fd4179
DT		 1695 grant_lock(r, lkb);
1696 queue_cast(r, lkb, 0);
1697 goto out;
1698 }
1699
1700 if (can_be_queued(lkb)) {
1701 error = -EINPROGRESS;
1702 add_lkb(r, lkb, DLM_LKSTS_WAITING);
1703 send_blocking_asts(r, lkb);
1704 goto out;
1705 }
1706
1707 error = -EAGAIN;
1708 if (force_blocking_asts(lkb))
1709 send_blocking_asts_all(r, lkb);
1710 queue_cast(r, lkb, -EAGAIN);
1711
1712 out:
1713 return error;
1714}
1715
1716static int do_convert(struct dlm_rsb *r, struct dlm_lkb *lkb)
1717{
1718 int error = 0;
1719
1720 /* changing an existing lock may allow others to be granted */
1721
90135925 1722 if (can_be_granted(r, lkb, 1)) {
e7fd4179
DT		 1723 grant_lock(r, lkb);
1724 queue_cast(r, lkb, 0);
1725 grant_pending_locks(r);
1726 goto out;
1727 }
1728
1729 if (can_be_queued(lkb)) {
1730 if (is_demoted(lkb))
1731 grant_pending_locks(r);
1732 error = -EINPROGRESS;
1733 del_lkb(r, lkb);
1734 add_lkb(r, lkb, DLM_LKSTS_CONVERT);
1735 send_blocking_asts(r, lkb);
1736 goto out;
1737 }
1738
1739 error = -EAGAIN;
1740 if (force_blocking_asts(lkb))
1741 send_blocking_asts_all(r, lkb);
1742 queue_cast(r, lkb, -EAGAIN);
1743
1744 out:
1745 return error;
1746}
1747
1748static int do_unlock(struct dlm_rsb *r, struct dlm_lkb *lkb)
1749{
1750 remove_lock(r, lkb);
1751 queue_cast(r, lkb, -DLM_EUNLOCK);
1752 grant_pending_locks(r);
1753 return -DLM_EUNLOCK;
1754}
1755
597d0cae
DT		 1756/* FIXME: if revert_lock() finds that the lkb is granted, we should
1757 skip the queue_cast(ECANCEL). It indicates that the request/convert
1758 completed (and queued a normal ast) just before the cancel; we don't
1759 want to clobber the sb_result for the normal ast with ECANCEL. */
907b9bce 1760
e7fd4179
DT		 1761static int do_cancel(struct dlm_rsb *r, struct dlm_lkb *lkb)
1762{
1763 revert_lock(r, lkb);
1764 queue_cast(r, lkb, -DLM_ECANCEL);
1765 grant_pending_locks(r);
1766 return -DLM_ECANCEL;
1767}
1768
1769/*
1770 * Four stage 3 varieties:
1771 * _request_lock(), _convert_lock(), _unlock_lock(), _cancel_lock()
1772 */
1773
1774/* add a new lkb to a possibly new rsb, called by requesting process */
1775
1776static int _request_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
1777{
1778 int error;
1779
1780 /* set_master: sets lkb nodeid from r */
1781
1782 error = set_master(r, lkb);
1783 if (error < 0)
1784 goto out;
1785 if (error) {
1786 error = 0;
1787 goto out;
1788 }
1789
1790 if (is_remote(r))
1791 /* receive_request() calls do_request() on remote node */
1792 error = send_request(r, lkb);
1793 else
1794 error = do_request(r, lkb);
1795 out:
1796 return error;
1797}
1798
3bcd3687 1799/* change some property of an existing lkb, e.g. mode */
e7fd4179
DT		 1800
1801static int _convert_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
1802{
1803 int error;
1804
1805 if (is_remote(r))
1806 /* receive_convert() calls do_convert() on remote node */
1807 error = send_convert(r, lkb);
1808 else
1809 error = do_convert(r, lkb);
1810
1811 return error;
1812}
1813
1814/* remove an existing lkb from the granted queue */
1815
1816static int _unlock_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
1817{
1818 int error;
1819
1820 if (is_remote(r))
1821 /* receive_unlock() calls do_unlock() on remote node */
1822 error = send_unlock(r, lkb);
1823 else
1824 error = do_unlock(r, lkb);
1825
1826 return error;
1827}
1828
1829/* remove an existing lkb from the convert or wait queue */
1830
1831static int _cancel_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
1832{
1833 int error;
1834
1835 if (is_remote(r))
1836 /* receive_cancel() calls do_cancel() on remote node */
1837 error = send_cancel(r, lkb);
1838 else
1839 error = do_cancel(r, lkb);
1840
1841 return error;
1842}
1843
1844/*
1845 * Four stage 2 varieties:
1846 * request_lock(), convert_lock(), unlock_lock(), cancel_lock()
1847 */
1848
1849static int request_lock(struct dlm_ls *ls, struct dlm_lkb *lkb, char *name,
1850 int len, struct dlm_args *args)
1851{
1852 struct dlm_rsb *r;
1853 int error;
1854
1855 error = validate_lock_args(ls, lkb, args);
1856 if (error)
1857 goto out;
1858
1859 error = find_rsb(ls, name, len, R_CREATE, &r);
1860 if (error)
1861 goto out;
1862
1863 lock_rsb(r);
1864
1865 attach_lkb(r, lkb);
1866 lkb->lkb_lksb->sb_lkid = lkb->lkb_id;
1867
1868 error = _request_lock(r, lkb);
1869
1870 unlock_rsb(r);
1871 put_rsb(r);
1872
1873 out:
1874 return error;
1875}
1876
1877static int convert_lock(struct dlm_ls *ls, struct dlm_lkb *lkb,
1878 struct dlm_args *args)
1879{
1880 struct dlm_rsb *r;
1881 int error;
1882
1883 r = lkb->lkb_resource;
1884
1885 hold_rsb(r);
1886 lock_rsb(r);
1887
1888 error = validate_lock_args(ls, lkb, args);
1889 if (error)
1890 goto out;
1891
1892 error = _convert_lock(r, lkb);
1893 out:
1894 unlock_rsb(r);
1895 put_rsb(r);
1896 return error;
1897}
1898
1899static int unlock_lock(struct dlm_ls *ls, struct dlm_lkb *lkb,
1900 struct dlm_args *args)
1901{
1902 struct dlm_rsb *r;
1903 int error;
1904
1905 r = lkb->lkb_resource;
1906
1907 hold_rsb(r);
1908 lock_rsb(r);
1909
1910 error = validate_unlock_args(lkb, args);
1911 if (error)
1912 goto out;
1913
1914 error = _unlock_lock(r, lkb);
1915 out:
1916 unlock_rsb(r);
1917 put_rsb(r);
1918 return error;
1919}
1920
1921static int cancel_lock(struct dlm_ls *ls, struct dlm_lkb *lkb,
1922 struct dlm_args *args)
1923{
1924 struct dlm_rsb *r;
1925 int error;
1926
1927 r = lkb->lkb_resource;
1928
1929 hold_rsb(r);
1930 lock_rsb(r);
1931
1932 error = validate_unlock_args(lkb, args);
1933 if (error)
1934 goto out;
1935
1936 error = _cancel_lock(r, lkb);
1937 out:
1938 unlock_rsb(r);
1939 put_rsb(r);
1940 return error;
1941}
1942
1943/*
1944 * Two stage 1 varieties: dlm_lock() and dlm_unlock()
1945 */
1946
1947int dlm_lock(dlm_lockspace_t *lockspace,
1948 int mode,
1949 struct dlm_lksb *lksb,
1950 uint32_t flags,
1951 void *name,
1952 unsigned int namelen,
1953 uint32_t parent_lkid,
1954 void (*ast) (void *astarg),
1955 void *astarg,
3bcd3687 1956 void (*bast) (void *astarg, int mode))
e7fd4179
DT		 1957{
1958 struct dlm_ls *ls;
1959 struct dlm_lkb *lkb;
1960 struct dlm_args args;
1961 int error, convert = flags & DLM_LKF_CONVERT;
1962
1963 ls = dlm_find_lockspace_local(lockspace);
1964 if (!ls)
1965 return -EINVAL;
1966
1967 lock_recovery(ls);
1968
1969 if (convert)
1970 error = find_lkb(ls, lksb->sb_lkid, &lkb);
1971 else
1972 error = create_lkb(ls, &lkb);
1973
1974 if (error)
1975 goto out;
1976
1977 error = set_lock_args(mode, lksb, flags, namelen, parent_lkid, ast,
3bcd3687 1978 astarg, bast, &args);
e7fd4179
DT		 1979 if (error)
1980 goto out_put;
1981
1982 if (convert)
1983 error = convert_lock(ls, lkb, &args);
1984 else
1985 error = request_lock(ls, lkb, name, namelen, &args);
1986
1987 if (error == -EINPROGRESS)
1988 error = 0;
1989 out_put:
1990 if (convert || error)
b3f58d8f 1991 __put_lkb(ls, lkb);
e7fd4179
DT		 1992 if (error == -EAGAIN)
1993 error = 0;
1994 out:
1995 unlock_recovery(ls);
1996 dlm_put_lockspace(ls);
1997 return error;
1998}
1999
2000int dlm_unlock(dlm_lockspace_t *lockspace,
2001 uint32_t lkid,
2002 uint32_t flags,
2003 struct dlm_lksb *lksb,
2004 void *astarg)
2005{
2006 struct dlm_ls *ls;
2007 struct dlm_lkb *lkb;
2008 struct dlm_args args;
2009 int error;
2010
2011 ls = dlm_find_lockspace_local(lockspace);
2012 if (!ls)
2013 return -EINVAL;
2014
2015 lock_recovery(ls);
2016
2017 error = find_lkb(ls, lkid, &lkb);
2018 if (error)
2019 goto out;
2020
2021 error = set_unlock_args(flags, astarg, &args);
2022 if (error)
2023 goto out_put;
2024
2025 if (flags & DLM_LKF_CANCEL)
2026 error = cancel_lock(ls, lkb, &args);
2027 else
2028 error = unlock_lock(ls, lkb, &args);
2029
2030 if (error == -DLM_EUNLOCK || error == -DLM_ECANCEL)
2031 error = 0;
2032 out_put:
b3f58d8f 2033 dlm_put_lkb(lkb);
e7fd4179
DT		 2034 out:
2035 unlock_recovery(ls);
2036 dlm_put_lockspace(ls);
2037 return error;
2038}
2039
2040/*
2041 * send/receive routines for remote operations and replies
2042 *
2043 * send_args
2044 * send_common
2045 * send_request receive_request
2046 * send_convert receive_convert
2047 * send_unlock receive_unlock
2048 * send_cancel receive_cancel
2049 * send_grant receive_grant
2050 * send_bast receive_bast
2051 * send_lookup receive_lookup
2052 * send_remove receive_remove
2053 *
2054 * send_common_reply
2055 * receive_request_reply send_request_reply
2056 * receive_convert_reply send_convert_reply
2057 * receive_unlock_reply send_unlock_reply
2058 * receive_cancel_reply send_cancel_reply
2059 * receive_lookup_reply send_lookup_reply
2060 */
2061
2062static int create_message(struct dlm_rsb *r, struct dlm_lkb *lkb,
2063 int to_nodeid, int mstype,
2064 struct dlm_message **ms_ret,
2065 struct dlm_mhandle **mh_ret)
2066{
2067 struct dlm_message *ms;
2068 struct dlm_mhandle *mh;
2069 char *mb;
2070 int mb_len = sizeof(struct dlm_message);
2071
2072 switch (mstype) {
2073 case DLM_MSG_REQUEST:
2074 case DLM_MSG_LOOKUP:
2075 case DLM_MSG_REMOVE:
2076 mb_len += r->res_length;
2077 break;
2078 case DLM_MSG_CONVERT:
2079 case DLM_MSG_UNLOCK:
2080 case DLM_MSG_REQUEST_REPLY:
2081 case DLM_MSG_CONVERT_REPLY:
2082 case DLM_MSG_GRANT:
2083 if (lkb && lkb->lkb_lvbptr)
2084 mb_len += r->res_ls->ls_lvblen;
2085 break;
2086 }
2087
2088 /* get_buffer gives us a message handle (mh) that we need to
2089 pass into lowcomms_commit and a message buffer (mb) that we
2090 write our data into */
2091
2092 mh = dlm_lowcomms_get_buffer(to_nodeid, mb_len, GFP_KERNEL, &mb);
2093 if (!mh)
2094 return -ENOBUFS;
2095
2096 memset(mb, 0, mb_len);
2097
2098 ms = (struct dlm_message *) mb;
2099
2100 ms->m_header.h_version = (DLM_HEADER_MAJOR | DLM_HEADER_MINOR);
2101 ms->m_header.h_lockspace = r->res_ls->ls_global_id;
2102 ms->m_header.h_nodeid = dlm_our_nodeid();
2103 ms->m_header.h_length = mb_len;
2104 ms->m_header.h_cmd = DLM_MSG;
2105
2106 ms->m_type = mstype;
2107
2108 *mh_ret = mh;
2109 *ms_ret = ms;
2110 return 0;
2111}
2112
2113/* further lowcomms enhancements or alternate implementations may make
2114 the return value from this function useful at some point */
2115
2116static int send_message(struct dlm_mhandle *mh, struct dlm_message *ms)
2117{
2118 dlm_message_out(ms);
2119 dlm_lowcomms_commit_buffer(mh);
2120 return 0;
2121}
2122
2123static void send_args(struct dlm_rsb *r, struct dlm_lkb *lkb,
2124 struct dlm_message *ms)
2125{
2126 ms->m_nodeid = lkb->lkb_nodeid;
2127 ms->m_pid = lkb->lkb_ownpid;
2128 ms->m_lkid = lkb->lkb_id;
2129 ms->m_remid = lkb->lkb_remid;
2130 ms->m_exflags = lkb->lkb_exflags;
2131 ms->m_sbflags = lkb->lkb_sbflags;
2132 ms->m_flags = lkb->lkb_flags;
2133 ms->m_lvbseq = lkb->lkb_lvbseq;
2134 ms->m_status = lkb->lkb_status;
2135 ms->m_grmode = lkb->lkb_grmode;
2136 ms->m_rqmode = lkb->lkb_rqmode;
2137 ms->m_hash = r->res_hash;
2138
2139 /* m_result and m_bastmode are set from function args,
2140 not from lkb fields */
2141
2142 if (lkb->lkb_bastaddr)
2143 ms->m_asts |= AST_BAST;
2144 if (lkb->lkb_astaddr)
2145 ms->m_asts |= AST_COMP;
2146
da49f36f
DT		 2147 /* compare with switch in create_message; send_remove() doesn't
2148 use send_args() */
e7fd4179 2149
da49f36f
DT		 2150 switch (ms->m_type) {
2151 case DLM_MSG_REQUEST:
2152 case DLM_MSG_LOOKUP:
2153 memcpy(ms->m_extra, r->res_name, r->res_length);
2154 break;
2155 case DLM_MSG_CONVERT:
2156 case DLM_MSG_UNLOCK:
2157 case DLM_MSG_REQUEST_REPLY:
2158 case DLM_MSG_CONVERT_REPLY:
2159 case DLM_MSG_GRANT:
2160 if (!lkb->lkb_lvbptr)
2161 break;
e7fd4179 2162 memcpy(ms->m_extra, lkb->lkb_lvbptr, r->res_ls->ls_lvblen);
da49f36f
DT		 2163 break;
2164 }
e7fd4179
DT		 2165}
2166
2167static int send_common(struct dlm_rsb *r, struct dlm_lkb *lkb, int mstype)
2168{
2169 struct dlm_message *ms;
2170 struct dlm_mhandle *mh;
2171 int to_nodeid, error;
2172
2173 add_to_waiters(lkb, mstype);
2174
2175 to_nodeid = r->res_nodeid;
2176
2177 error = create_message(r, lkb, to_nodeid, mstype, &ms, &mh);
2178 if (error)
2179 goto fail;
2180
2181 send_args(r, lkb, ms);
2182
2183 error = send_message(mh, ms);
2184 if (error)
2185 goto fail;
2186 return 0;
2187
2188 fail:
2189 remove_from_waiters(lkb);
2190 return error;
2191}
2192
2193static int send_request(struct dlm_rsb *r, struct dlm_lkb *lkb)
2194{
2195 return send_common(r, lkb, DLM_MSG_REQUEST);
2196}
2197
2198static int send_convert(struct dlm_rsb *r, struct dlm_lkb *lkb)
2199{
2200 int error;
2201
2202 error = send_common(r, lkb, DLM_MSG_CONVERT);
2203
2204 /* down conversions go without a reply from the master */
2205 if (!error && down_conversion(lkb)) {
2206 remove_from_waiters(lkb);
2207 r->res_ls->ls_stub_ms.m_result = 0;
32f105a1 2208 r->res_ls->ls_stub_ms.m_flags = lkb->lkb_flags;
e7fd4179
DT		 2209 __receive_convert_reply(r, lkb, &r->res_ls->ls_stub_ms);
2210 }
2211
2212 return error;
2213}
2214
2215/* FIXME: if this lkb is the only lock we hold on the rsb, then set
2216 MASTER_UNCERTAIN to force the next request on the rsb to confirm
2217 that the master is still correct. */
2218
2219static int send_unlock(struct dlm_rsb *r, struct dlm_lkb *lkb)
2220{
2221 return send_common(r, lkb, DLM_MSG_UNLOCK);
2222}
2223
2224static int send_cancel(struct dlm_rsb *r, struct dlm_lkb *lkb)
2225{
2226 return send_common(r, lkb, DLM_MSG_CANCEL);
2227}
2228
2229static int send_grant(struct dlm_rsb *r, struct dlm_lkb *lkb)
2230{
2231 struct dlm_message *ms;
2232 struct dlm_mhandle *mh;
2233 int to_nodeid, error;
2234
2235 to_nodeid = lkb->lkb_nodeid;
2236
2237 error = create_message(r, lkb, to_nodeid, DLM_MSG_GRANT, &ms, &mh);
2238 if (error)
2239 goto out;
2240
2241 send_args(r, lkb, ms);
2242
2243 ms->m_result = 0;
2244
2245 error = send_message(mh, ms);
2246 out:
2247 return error;
2248}
2249
2250static int send_bast(struct dlm_rsb *r, struct dlm_lkb *lkb, int mode)
2251{
2252 struct dlm_message *ms;
2253 struct dlm_mhandle *mh;
2254 int to_nodeid, error;
2255
2256 to_nodeid = lkb->lkb_nodeid;
2257
2258 error = create_message(r, NULL, to_nodeid, DLM_MSG_BAST, &ms, &mh);
2259 if (error)
2260 goto out;
2261
2262 send_args(r, lkb, ms);
2263
2264 ms->m_bastmode = mode;
2265
2266 error = send_message(mh, ms);
2267 out:
2268 return error;
2269}
2270
2271static int send_lookup(struct dlm_rsb *r, struct dlm_lkb *lkb)
2272{
2273 struct dlm_message *ms;
2274 struct dlm_mhandle *mh;
2275 int to_nodeid, error;
2276
2277 add_to_waiters(lkb, DLM_MSG_LOOKUP);
2278
2279 to_nodeid = dlm_dir_nodeid(r);
2280
2281 error = create_message(r, NULL, to_nodeid, DLM_MSG_LOOKUP, &ms, &mh);
2282 if (error)
2283 goto fail;
2284
2285 send_args(r, lkb, ms);
2286
2287 error = send_message(mh, ms);
2288 if (error)
2289 goto fail;
2290 return 0;
2291
2292 fail:
2293 remove_from_waiters(lkb);
2294 return error;
2295}
2296
2297static int send_remove(struct dlm_rsb *r)
2298{
2299 struct dlm_message *ms;
2300 struct dlm_mhandle *mh;
2301 int to_nodeid, error;
2302
2303 to_nodeid = dlm_dir_nodeid(r);
2304
2305 error = create_message(r, NULL, to_nodeid, DLM_MSG_REMOVE, &ms, &mh);
2306 if (error)
2307 goto out;
2308
2309 memcpy(ms->m_extra, r->res_name, r->res_length);
2310 ms->m_hash = r->res_hash;
2311
2312 error = send_message(mh, ms);
2313 out:
2314 return error;
2315}
2316
2317static int send_common_reply(struct dlm_rsb *r, struct dlm_lkb *lkb,
2318 int mstype, int rv)
2319{
2320 struct dlm_message *ms;
2321 struct dlm_mhandle *mh;
2322 int to_nodeid, error;
2323
2324 to_nodeid = lkb->lkb_nodeid;
2325
2326 error = create_message(r, lkb, to_nodeid, mstype, &ms, &mh);
2327 if (error)
2328 goto out;
2329
2330 send_args(r, lkb, ms);
2331
2332 ms->m_result = rv;
2333
2334 error = send_message(mh, ms);
2335 out:
2336 return error;
2337}
2338
2339static int send_request_reply(struct dlm_rsb *r, struct dlm_lkb *lkb, int rv)
2340{
2341 return send_common_reply(r, lkb, DLM_MSG_REQUEST_REPLY, rv);
2342}
2343
2344static int send_convert_reply(struct dlm_rsb *r, struct dlm_lkb *lkb, int rv)
2345{
2346 return send_common_reply(r, lkb, DLM_MSG_CONVERT_REPLY, rv);
2347}
2348
2349static int send_unlock_reply(struct dlm_rsb *r, struct dlm_lkb *lkb, int rv)
2350{
2351 return send_common_reply(r, lkb, DLM_MSG_UNLOCK_REPLY, rv);
2352}
2353
2354static int send_cancel_reply(struct dlm_rsb *r, struct dlm_lkb *lkb, int rv)
2355{
2356 return send_common_reply(r, lkb, DLM_MSG_CANCEL_REPLY, rv);
2357}
2358
2359static int send_lookup_reply(struct dlm_ls *ls, struct dlm_message *ms_in,
2360 int ret_nodeid, int rv)
2361{
2362 struct dlm_rsb *r = &ls->ls_stub_rsb;
2363 struct dlm_message *ms;
2364 struct dlm_mhandle *mh;
2365 int error, nodeid = ms_in->m_header.h_nodeid;
2366
2367 error = create_message(r, NULL, nodeid, DLM_MSG_LOOKUP_REPLY, &ms, &mh);
2368 if (error)
2369 goto out;
2370
2371 ms->m_lkid = ms_in->m_lkid;
2372 ms->m_result = rv;
2373 ms->m_nodeid = ret_nodeid;
2374
2375 error = send_message(mh, ms);
2376 out:
2377 return error;
2378}
2379
2380/* which args we save from a received message depends heavily on the type
2381 of message, unlike the send side where we can safely send everything about
2382 the lkb for any type of message */
2383
2384static void receive_flags(struct dlm_lkb *lkb, struct dlm_message *ms)
2385{
2386 lkb->lkb_exflags = ms->m_exflags;
6f90a8b1 2387 lkb->lkb_sbflags = ms->m_sbflags;
e7fd4179
DT		 2388 lkb->lkb_flags = (lkb->lkb_flags & 0xFFFF0000) |
2389 (ms->m_flags & 0x0000FFFF);
2390}
2391
2392static void receive_flags_reply(struct dlm_lkb *lkb, struct dlm_message *ms)
2393{
2394 lkb->lkb_sbflags = ms->m_sbflags;
2395 lkb->lkb_flags = (lkb->lkb_flags & 0xFFFF0000) |
2396 (ms->m_flags & 0x0000FFFF);
2397}
2398
2399static int receive_extralen(struct dlm_message *ms)
2400{
2401 return (ms->m_header.h_length - sizeof(struct dlm_message));
2402}
2403
e7fd4179
DT		 2404static int receive_lvb(struct dlm_ls *ls, struct dlm_lkb *lkb,
2405 struct dlm_message *ms)
2406{
2407 int len;
2408
2409 if (lkb->lkb_exflags & DLM_LKF_VALBLK) {
2410 if (!lkb->lkb_lvbptr)
2411 lkb->lkb_lvbptr = allocate_lvb(ls);
2412 if (!lkb->lkb_lvbptr)
2413 return -ENOMEM;
2414 len = receive_extralen(ms);
2415 memcpy(lkb->lkb_lvbptr, ms->m_extra, len);
2416 }
2417 return 0;
2418}
2419
2420static int receive_request_args(struct dlm_ls *ls, struct dlm_lkb *lkb,
2421 struct dlm_message *ms)
2422{
2423 lkb->lkb_nodeid = ms->m_header.h_nodeid;
2424 lkb->lkb_ownpid = ms->m_pid;
2425 lkb->lkb_remid = ms->m_lkid;
2426 lkb->lkb_grmode = DLM_LOCK_IV;
2427 lkb->lkb_rqmode = ms->m_rqmode;
2428 lkb->lkb_bastaddr = (void *) (long) (ms->m_asts & AST_BAST);
2429 lkb->lkb_astaddr = (void *) (long) (ms->m_asts & AST_COMP);
2430
2431 DLM_ASSERT(is_master_copy(lkb), dlm_print_lkb(lkb););
2432
8d07fd50
DT		 2433 if (lkb->lkb_exflags & DLM_LKF_VALBLK) {
2434 /* lkb was just created so there won't be an lvb yet */
2435 lkb->lkb_lvbptr = allocate_lvb(ls);
2436 if (!lkb->lkb_lvbptr)
2437 return -ENOMEM;
2438 }
e7fd4179
DT		 2439
2440 return 0;
2441}
2442
2443static int receive_convert_args(struct dlm_ls *ls, struct dlm_lkb *lkb,
2444 struct dlm_message *ms)
2445{
2446 if (lkb->lkb_nodeid != ms->m_header.h_nodeid) {
2447 log_error(ls, "convert_args nodeid %d %d lkid %x %x",
2448 lkb->lkb_nodeid, ms->m_header.h_nodeid,
2449 lkb->lkb_id, lkb->lkb_remid);
2450 return -EINVAL;
2451 }
2452
2453 if (!is_master_copy(lkb))
2454 return -EINVAL;
2455
2456 if (lkb->lkb_status != DLM_LKSTS_GRANTED)
2457 return -EBUSY;
2458
e7fd4179
DT		 2459 if (receive_lvb(ls, lkb, ms))
2460 return -ENOMEM;
2461
2462 lkb->lkb_rqmode = ms->m_rqmode;
2463 lkb->lkb_lvbseq = ms->m_lvbseq;
2464
2465 return 0;
2466}
2467
2468static int receive_unlock_args(struct dlm_ls *ls, struct dlm_lkb *lkb,
2469 struct dlm_message *ms)
2470{
2471 if (!is_master_copy(lkb))
2472 return -EINVAL;
2473 if (receive_lvb(ls, lkb, ms))
2474 return -ENOMEM;
2475 return 0;
2476}
2477
2478/* We fill in the stub-lkb fields with the info that send_xxxx_reply()
2479 uses to send a reply and that the remote end uses to process the reply. */
2480
2481static void setup_stub_lkb(struct dlm_ls *ls, struct dlm_message *ms)
2482{
2483 struct dlm_lkb *lkb = &ls->ls_stub_lkb;
2484 lkb->lkb_nodeid = ms->m_header.h_nodeid;
2485 lkb->lkb_remid = ms->m_lkid;
2486}
2487
2488static void receive_request(struct dlm_ls *ls, struct dlm_message *ms)
2489{
2490 struct dlm_lkb *lkb;
2491 struct dlm_rsb *r;
2492 int error, namelen;
2493
2494 error = create_lkb(ls, &lkb);
2495 if (error)
2496 goto fail;
2497
2498 receive_flags(lkb, ms);
2499 lkb->lkb_flags |= DLM_IFL_MSTCPY;
2500 error = receive_request_args(ls, lkb, ms);
2501 if (error) {
b3f58d8f 2502 __put_lkb(ls, lkb);
e7fd4179
DT		 2503 goto fail;
2504 }
2505
2506 namelen = receive_extralen(ms);
2507
2508 error = find_rsb(ls, ms->m_extra, namelen, R_MASTER, &r);
2509 if (error) {
b3f58d8f 2510 __put_lkb(ls, lkb);
e7fd4179
DT		 2511 goto fail;
2512 }
2513
2514 lock_rsb(r);
2515
2516 attach_lkb(r, lkb);
2517 error = do_request(r, lkb);
2518 send_request_reply(r, lkb, error);
2519
2520 unlock_rsb(r);
2521 put_rsb(r);
2522
2523 if (error == -EINPROGRESS)
2524 error = 0;
2525 if (error)
b3f58d8f 2526 dlm_put_lkb(lkb);
e7fd4179
DT		 2527 return;
2528
2529 fail:
2530 setup_stub_lkb(ls, ms);
2531 send_request_reply(&ls->ls_stub_rsb, &ls->ls_stub_lkb, error);
2532}
2533
2534static void receive_convert(struct dlm_ls *ls, struct dlm_message *ms)
2535{
2536 struct dlm_lkb *lkb;
2537 struct dlm_rsb *r;
90135925 2538 int error, reply = 1;
e7fd4179
DT		 2539
2540 error = find_lkb(ls, ms->m_remid, &lkb);
2541 if (error)
2542 goto fail;
2543
2544 r = lkb->lkb_resource;
2545
2546 hold_rsb(r);
2547 lock_rsb(r);
2548
2549 receive_flags(lkb, ms);
2550 error = receive_convert_args(ls, lkb, ms);
2551 if (error)
2552 goto out;
2553 reply = !down_conversion(lkb);
2554
2555 error = do_convert(r, lkb);
2556 out:
2557 if (reply)
2558 send_convert_reply(r, lkb, error);
2559
2560 unlock_rsb(r);
2561 put_rsb(r);
b3f58d8f 2562 dlm_put_lkb(lkb);
e7fd4179
DT		 2563 return;
2564
2565 fail:
2566 setup_stub_lkb(ls, ms);
2567 send_convert_reply(&ls->ls_stub_rsb, &ls->ls_stub_lkb, error);
2568}
2569
2570static void receive_unlock(struct dlm_ls *ls, struct dlm_message *ms)
2571{
2572 struct dlm_lkb *lkb;
2573 struct dlm_rsb *r;
2574 int error;
2575
2576 error = find_lkb(ls, ms->m_remid, &lkb);
2577 if (error)
2578 goto fail;
2579
2580 r = lkb->lkb_resource;
2581
2582 hold_rsb(r);
2583 lock_rsb(r);
2584
2585 receive_flags(lkb, ms);
2586 error = receive_unlock_args(ls, lkb, ms);
2587 if (error)
2588 goto out;
2589
2590 error = do_unlock(r, lkb);
2591 out:
2592 send_unlock_reply(r, lkb, error);
2593
2594 unlock_rsb(r);
2595 put_rsb(r);
b3f58d8f 2596 dlm_put_lkb(lkb);
e7fd4179
DT		 2597 return;
2598
2599 fail:
2600 setup_stub_lkb(ls, ms);
2601 send_unlock_reply(&ls->ls_stub_rsb, &ls->ls_stub_lkb, error);
2602}
2603
2604static void receive_cancel(struct dlm_ls *ls, struct dlm_message *ms)
2605{
2606 struct dlm_lkb *lkb;
2607 struct dlm_rsb *r;
2608 int error;
2609
2610 error = find_lkb(ls, ms->m_remid, &lkb);
2611 if (error)
2612 goto fail;
2613
2614 receive_flags(lkb, ms);
2615
2616 r = lkb->lkb_resource;
2617
2618 hold_rsb(r);
2619 lock_rsb(r);
2620
2621 error = do_cancel(r, lkb);
2622 send_cancel_reply(r, lkb, error);
2623
2624 unlock_rsb(r);
2625 put_rsb(r);
b3f58d8f 2626 dlm_put_lkb(lkb);
e7fd4179
DT		 2627 return;
2628
2629 fail:
2630 setup_stub_lkb(ls, ms);
2631 send_cancel_reply(&ls->ls_stub_rsb, &ls->ls_stub_lkb, error);
2632}
2633
2634static void receive_grant(struct dlm_ls *ls, struct dlm_message *ms)
2635{
2636 struct dlm_lkb *lkb;
2637 struct dlm_rsb *r;
2638 int error;
2639
2640 error = find_lkb(ls, ms->m_remid, &lkb);
2641 if (error) {
2642 log_error(ls, "receive_grant no lkb");
2643 return;
2644 }
2645 DLM_ASSERT(is_process_copy(lkb), dlm_print_lkb(lkb););
2646
2647 r = lkb->lkb_resource;
2648
2649 hold_rsb(r);
2650 lock_rsb(r);
2651
2652 receive_flags_reply(lkb, ms);
2653 grant_lock_pc(r, lkb, ms);
2654 queue_cast(r, lkb, 0);
2655
2656 unlock_rsb(r);
2657 put_rsb(r);
b3f58d8f 2658 dlm_put_lkb(lkb);
e7fd4179
DT		 2659}
2660
2661static void receive_bast(struct dlm_ls *ls, struct dlm_message *ms)
2662{
2663 struct dlm_lkb *lkb;
2664 struct dlm_rsb *r;
2665 int error;
2666
2667 error = find_lkb(ls, ms->m_remid, &lkb);
2668 if (error) {
2669 log_error(ls, "receive_bast no lkb");
2670 return;
2671 }
2672 DLM_ASSERT(is_process_copy(lkb), dlm_print_lkb(lkb););
2673
2674 r = lkb->lkb_resource;
2675
2676 hold_rsb(r);
2677 lock_rsb(r);
2678
2679 queue_bast(r, lkb, ms->m_bastmode);
2680
2681 unlock_rsb(r);
2682 put_rsb(r);
b3f58d8f 2683 dlm_put_lkb(lkb);
e7fd4179
DT		 2684}
2685
2686static void receive_lookup(struct dlm_ls *ls, struct dlm_message *ms)
2687{
2688 int len, error, ret_nodeid, dir_nodeid, from_nodeid, our_nodeid;
2689
2690 from_nodeid = ms->m_header.h_nodeid;
2691 our_nodeid = dlm_our_nodeid();
2692
2693 len = receive_extralen(ms);
2694
2695 dir_nodeid = dlm_hash2nodeid(ls, ms->m_hash);
2696 if (dir_nodeid != our_nodeid) {
2697 log_error(ls, "lookup dir_nodeid %d from %d",
2698 dir_nodeid, from_nodeid);
2699 error = -EINVAL;
2700 ret_nodeid = -1;
2701 goto out;
2702 }
2703
2704 error = dlm_dir_lookup(ls, from_nodeid, ms->m_extra, len, &ret_nodeid);
2705
2706 /* Optimization: we're master so treat lookup as a request */
2707 if (!error && ret_nodeid == our_nodeid) {
2708 receive_request(ls, ms);
2709 return;
2710 }
2711 out:
2712 send_lookup_reply(ls, ms, ret_nodeid, error);
2713}
2714
2715static void receive_remove(struct dlm_ls *ls, struct dlm_message *ms)
2716{
2717 int len, dir_nodeid, from_nodeid;
2718
2719 from_nodeid = ms->m_header.h_nodeid;
2720
2721 len = receive_extralen(ms);
2722
2723 dir_nodeid = dlm_hash2nodeid(ls, ms->m_hash);
2724 if (dir_nodeid != dlm_our_nodeid()) {
2725 log_error(ls, "remove dir entry dir_nodeid %d from %d",
2726 dir_nodeid, from_nodeid);
2727 return;
2728 }
2729
2730 dlm_dir_remove_entry(ls, from_nodeid, ms->m_extra, len);
2731}
2732
2733static void receive_request_reply(struct dlm_ls *ls, struct dlm_message *ms)
2734{
2735 struct dlm_lkb *lkb;
2736 struct dlm_rsb *r;
2737 int error, mstype;
2738
2739 error = find_lkb(ls, ms->m_remid, &lkb);
2740 if (error) {
2741 log_error(ls, "receive_request_reply no lkb");
2742 return;
2743 }
2744 DLM_ASSERT(is_process_copy(lkb), dlm_print_lkb(lkb););
2745
2746 mstype = lkb->lkb_wait_type;
2747 error = remove_from_waiters(lkb);
2748 if (error) {
2749 log_error(ls, "receive_request_reply not on waiters");
2750 goto out;
2751 }
2752
2753 /* this is the value returned from do_request() on the master */
2754 error = ms->m_result;
2755
2756 r = lkb->lkb_resource;
2757 hold_rsb(r);
2758 lock_rsb(r);
2759
2760 /* Optimization: the dir node was also the master, so it took our
2761 lookup as a request and sent request reply instead of lookup reply */
2762 if (mstype == DLM_MSG_LOOKUP) {
2763 r->res_nodeid = ms->m_header.h_nodeid;
2764 lkb->lkb_nodeid = r->res_nodeid;
2765 }
2766
2767 switch (error) {
2768 case -EAGAIN:
2769 /* request would block (be queued) on remote master;
2770 the unhold undoes the original ref from create_lkb()
2771 so it leads to the lkb being freed */
2772 queue_cast(r, lkb, -EAGAIN);
2773 confirm_master(r, -EAGAIN);
2774 unhold_lkb(lkb);
2775 break;
2776
2777 case -EINPROGRESS:
2778 case 0:
2779 /* request was queued or granted on remote master */
2780 receive_flags_reply(lkb, ms);
2781 lkb->lkb_remid = ms->m_lkid;
2782 if (error)
2783 add_lkb(r, lkb, DLM_LKSTS_WAITING);
2784 else {
2785 grant_lock_pc(r, lkb, ms);
2786 queue_cast(r, lkb, 0);
2787 }
2788 confirm_master(r, error);
2789 break;
2790
597d0cae 2791 case -EBADR:
e7fd4179
DT		 2792 case -ENOTBLK:
2793 /* find_rsb failed to find rsb or rsb wasn't master */
2794 r->res_nodeid = -1;
2795 lkb->lkb_nodeid = -1;
2796 _request_lock(r, lkb);
2797 break;
2798
2799 default:
2800 log_error(ls, "receive_request_reply error %d", error);
2801 }
2802
2803 unlock_rsb(r);
2804 put_rsb(r);
2805 out:
b3f58d8f 2806 dlm_put_lkb(lkb);
e7fd4179
DT		 2807}
2808
2809static void __receive_convert_reply(struct dlm_rsb *r, struct dlm_lkb *lkb,
2810 struct dlm_message *ms)
2811{
2812 int error = ms->m_result;
2813
2814 /* this is the value returned from do_convert() on the master */
2815
2816 switch (error) {
2817 case -EAGAIN:
2818 /* convert would block (be queued) on remote master */
2819 queue_cast(r, lkb, -EAGAIN);
2820 break;
2821
2822 case -EINPROGRESS:
2823 /* convert was queued on remote master */
2824 del_lkb(r, lkb);
2825 add_lkb(r, lkb, DLM_LKSTS_CONVERT);
2826 break;
2827
2828 case 0:
2829 /* convert was granted on remote master */
2830 receive_flags_reply(lkb, ms);
2831 grant_lock_pc(r, lkb, ms);
2832 queue_cast(r, lkb, 0);
2833 break;
2834
2835 default:
2836 log_error(r->res_ls, "receive_convert_reply error %d", error);
2837 }
2838}
2839
2840static void _receive_convert_reply(struct dlm_lkb *lkb, struct dlm_message *ms)
2841{
2842 struct dlm_rsb *r = lkb->lkb_resource;
2843
2844 hold_rsb(r);
2845 lock_rsb(r);
2846
2847 __receive_convert_reply(r, lkb, ms);
2848
2849 unlock_rsb(r);
2850 put_rsb(r);
2851}
2852
2853static void receive_convert_reply(struct dlm_ls *ls, struct dlm_message *ms)
2854{
2855 struct dlm_lkb *lkb;
2856 int error;
2857
2858 error = find_lkb(ls, ms->m_remid, &lkb);
2859 if (error) {
2860 log_error(ls, "receive_convert_reply no lkb");
2861 return;
2862 }
2863 DLM_ASSERT(is_process_copy(lkb), dlm_print_lkb(lkb););
2864
2865 error = remove_from_waiters(lkb);
2866 if (error) {
2867 log_error(ls, "receive_convert_reply not on waiters");
2868 goto out;
2869 }
2870
2871 _receive_convert_reply(lkb, ms);
2872 out:
b3f58d8f 2873 dlm_put_lkb(lkb);
e7fd4179
DT		 2874}
2875
2876static void _receive_unlock_reply(struct dlm_lkb *lkb, struct dlm_message *ms)
2877{
2878 struct dlm_rsb *r = lkb->lkb_resource;
2879 int error = ms->m_result;
2880
2881 hold_rsb(r);
2882 lock_rsb(r);
2883
2884 /* this is the value returned from do_unlock() on the master */
2885
2886 switch (error) {
2887 case -DLM_EUNLOCK:
2888 receive_flags_reply(lkb, ms);
2889 remove_lock_pc(r, lkb);
2890 queue_cast(r, lkb, -DLM_EUNLOCK);
2891 break;
2892 default:
2893 log_error(r->res_ls, "receive_unlock_reply error %d", error);
2894 }
2895
2896 unlock_rsb(r);
2897 put_rsb(r);
2898}
2899
2900static void receive_unlock_reply(struct dlm_ls *ls, struct dlm_message *ms)
2901{
2902 struct dlm_lkb *lkb;
2903 int error;
2904
2905 error = find_lkb(ls, ms->m_remid, &lkb);
2906 if (error) {
2907 log_error(ls, "receive_unlock_reply no lkb");
2908 return;
2909 }
2910 DLM_ASSERT(is_process_copy(lkb), dlm_print_lkb(lkb););
2911
2912 error = remove_from_waiters(lkb);
2913 if (error) {
2914 log_error(ls, "receive_unlock_reply not on waiters");
2915 goto out;
2916 }
2917
2918 _receive_unlock_reply(lkb, ms);
2919 out:
b3f58d8f 2920 dlm_put_lkb(lkb);
e7fd4179
DT		 2921}
2922
2923static void _receive_cancel_reply(struct dlm_lkb *lkb, struct dlm_message *ms)
2924{
2925 struct dlm_rsb *r = lkb->lkb_resource;
2926 int error = ms->m_result;
2927
2928 hold_rsb(r);
2929 lock_rsb(r);
2930
2931 /* this is the value returned from do_cancel() on the master */
2932
2933 switch (error) {
2934 case -DLM_ECANCEL:
2935 receive_flags_reply(lkb, ms);
2936 revert_lock_pc(r, lkb);
2937 queue_cast(r, lkb, -DLM_ECANCEL);
2938 break;
2939 default:
2940 log_error(r->res_ls, "receive_cancel_reply error %d", error);
2941 }
2942
2943 unlock_rsb(r);
2944 put_rsb(r);
2945}
2946
2947static void receive_cancel_reply(struct dlm_ls *ls, struct dlm_message *ms)
2948{
2949 struct dlm_lkb *lkb;
2950 int error;
2951
2952 error = find_lkb(ls, ms->m_remid, &lkb);
2953 if (error) {
2954 log_error(ls, "receive_cancel_reply no lkb");
2955 return;
2956 }
2957 DLM_ASSERT(is_process_copy(lkb), dlm_print_lkb(lkb););
2958
2959 error = remove_from_waiters(lkb);
2960 if (error) {
2961 log_error(ls, "receive_cancel_reply not on waiters");
2962 goto out;
2963 }
2964
2965 _receive_cancel_reply(lkb, ms);
2966 out:
b3f58d8f 2967 dlm_put_lkb(lkb);
e7fd4179
DT		 2968}
2969
2970static void receive_lookup_reply(struct dlm_ls *ls, struct dlm_message *ms)
2971{
2972 struct dlm_lkb *lkb;
2973 struct dlm_rsb *r;
2974 int error, ret_nodeid;
2975
2976 error = find_lkb(ls, ms->m_lkid, &lkb);
2977 if (error) {
2978 log_error(ls, "receive_lookup_reply no lkb");
2979 return;
2980 }
2981
2982 error = remove_from_waiters(lkb);
2983 if (error) {
2984 log_error(ls, "receive_lookup_reply not on waiters");
2985 goto out;
2986 }
2987
2988 /* this is the value returned by dlm_dir_lookup on dir node
2989 FIXME: will a non-zero error ever be returned? */
2990 error = ms->m_result;
2991
2992 r = lkb->lkb_resource;
2993 hold_rsb(r);
2994 lock_rsb(r);
2995
2996 ret_nodeid = ms->m_nodeid;
2997 if (ret_nodeid == dlm_our_nodeid()) {
2998 r->res_nodeid = 0;
2999 ret_nodeid = 0;
3000 r->res_first_lkid = 0;
3001 } else {
3002 /* set_master() will copy res_nodeid to lkb_nodeid */
3003 r->res_nodeid = ret_nodeid;
3004 }
3005
3006 _request_lock(r, lkb);
3007
3008 if (!ret_nodeid)
3009 process_lookup_list(r);
3010
3011 unlock_rsb(r);
3012 put_rsb(r);
3013 out:
b3f58d8f 3014 dlm_put_lkb(lkb);
e7fd4179
DT		 3015}
3016
3017int dlm_receive_message(struct dlm_header *hd, int nodeid, int recovery)
3018{
3019 struct dlm_message *ms = (struct dlm_message *) hd;
3020 struct dlm_ls *ls;
3021 int error;
3022
3023 if (!recovery)
3024 dlm_message_in(ms);
3025
3026 ls = dlm_find_lockspace_global(hd->h_lockspace);
3027 if (!ls) {
3028 log_print("drop message %d from %d for unknown lockspace %d",
3029 ms->m_type, nodeid, hd->h_lockspace);
3030 return -EINVAL;
3031 }
3032
3033 /* recovery may have just ended leaving a bunch of backed-up requests
3034 in the requestqueue; wait while dlm_recoverd clears them */
3035
3036 if (!recovery)
3037 dlm_wait_requestqueue(ls);
3038
3039 /* recovery may have just started while there were a bunch of
3040 in-flight requests -- save them in requestqueue to be processed
3041 after recovery. we can't let dlm_recvd block on the recovery
3042 lock. if dlm_recoverd is calling this function to clear the
3043 requestqueue, it needs to be interrupted (-EINTR) if another
3044 recovery operation is starting. */
3045
3046 while (1) {
3047 if (dlm_locking_stopped(ls)) {
d4400156
DT		 3048 if (recovery) {
3049 error = -EINTR;
3050 goto out;
3051 }
3052 error = dlm_add_requestqueue(ls, nodeid, hd);
3053 if (error == -EAGAIN)
3054 continue;
3055 else {
3056 error = -EINTR;
3057 goto out;
3058 }
e7fd4179
DT		 3059 }
3060
3061 if (lock_recovery_try(ls))
3062 break;
3063 schedule();
3064 }
3065
3066 switch (ms->m_type) {
3067
3068 /* messages sent to a master node */
3069
3070 case DLM_MSG_REQUEST:
3071 receive_request(ls, ms);
3072 break;
3073
3074 case DLM_MSG_CONVERT:
3075 receive_convert(ls, ms);
3076 break;
3077
3078 case DLM_MSG_UNLOCK:
3079 receive_unlock(ls, ms);
3080 break;
3081
3082 case DLM_MSG_CANCEL:
3083 receive_cancel(ls, ms);
3084 break;
3085
3086 /* messages sent from a master node (replies to above) */
3087
3088 case DLM_MSG_REQUEST_REPLY:
3089 receive_request_reply(ls, ms);
3090 break;
3091
3092 case DLM_MSG_CONVERT_REPLY:
3093 receive_convert_reply(ls, ms);
3094 break;
3095
3096 case DLM_MSG_UNLOCK_REPLY:
3097 receive_unlock_reply(ls, ms);
3098 break;
3099
3100 case DLM_MSG_CANCEL_REPLY:
3101 receive_cancel_reply(ls, ms);
3102 break;
3103
3104 /* messages sent from a master node (only two types of async msg) */
3105
3106 case DLM_MSG_GRANT:
3107 receive_grant(ls, ms);
3108 break;
3109
3110 case DLM_MSG_BAST:
3111 receive_bast(ls, ms);
3112 break;
3113
3114 /* messages sent to a dir node */
3115
3116 case DLM_MSG_LOOKUP:
3117 receive_lookup(ls, ms);
3118 break;
3119
3120 case DLM_MSG_REMOVE:
3121 receive_remove(ls, ms);
3122 break;
3123
3124 /* messages sent from a dir node (remove has no reply) */
3125
3126 case DLM_MSG_LOOKUP_REPLY:
3127 receive_lookup_reply(ls, ms);
3128 break;
3129
3130 default:
3131 log_error(ls, "unknown message type %d", ms->m_type);
3132 }
3133
3134 unlock_recovery(ls);
3135 out:
3136 dlm_put_lockspace(ls);
3137 dlm_astd_wake();
3138 return 0;
3139}
3140
3141
3142/*
3143 * Recovery related
3144 */
3145
3146static void recover_convert_waiter(struct dlm_ls *ls, struct dlm_lkb *lkb)
3147{
3148 if (middle_conversion(lkb)) {
3149 hold_lkb(lkb);
3150 ls->ls_stub_ms.m_result = -EINPROGRESS;
075529b5 3151 ls->ls_stub_ms.m_flags = lkb->lkb_flags;
e7fd4179
DT		 3152 _remove_from_waiters(lkb);
3153 _receive_convert_reply(lkb, &ls->ls_stub_ms);
3154
3155 /* Same special case as in receive_rcom_lock_args() */
3156 lkb->lkb_grmode = DLM_LOCK_IV;
3157 rsb_set_flag(lkb->lkb_resource, RSB_RECOVER_CONVERT);
3158 unhold_lkb(lkb);
3159
3160 } else if (lkb->lkb_rqmode >= lkb->lkb_grmode) {
3161 lkb->lkb_flags |= DLM_IFL_RESEND;
3162 }
3163
3164 /* lkb->lkb_rqmode < lkb->lkb_grmode shouldn't happen since down
3165 conversions are async; there's no reply from the remote master */
3166}
3167
3168/* A waiting lkb needs recovery if the master node has failed, or
3169 the master node is changing (only when no directory is used) */
3170
3171static int waiter_needs_recovery(struct dlm_ls *ls, struct dlm_lkb *lkb)
3172{
3173 if (dlm_is_removed(ls, lkb->lkb_nodeid))
3174 return 1;
3175
3176 if (!dlm_no_directory(ls))
3177 return 0;
3178
3179 if (dlm_dir_nodeid(lkb->lkb_resource) != lkb->lkb_nodeid)
3180 return 1;
3181
3182 return 0;
3183}
3184
3185/* Recovery for locks that are waiting for replies from nodes that are now
3186 gone. We can just complete unlocks and cancels by faking a reply from the
3187 dead node. Requests and up-conversions we flag to be resent after
3188 recovery. Down-conversions can just be completed with a fake reply like
3189 unlocks. Conversions between PR and CW need special attention. */
3190
3191void dlm_recover_waiters_pre(struct dlm_ls *ls)
3192{
3193 struct dlm_lkb *lkb, *safe;
3194
90135925 3195 mutex_lock(&ls->ls_waiters_mutex);
e7fd4179
DT		 3196
3197 list_for_each_entry_safe(lkb, safe, &ls->ls_waiters, lkb_wait_reply) {
3198 log_debug(ls, "pre recover waiter lkid %x type %d flags %x",
3199 lkb->lkb_id, lkb->lkb_wait_type, lkb->lkb_flags);
3200
3201 /* all outstanding lookups, regardless of destination will be
3202 resent after recovery is done */
3203
3204 if (lkb->lkb_wait_type == DLM_MSG_LOOKUP) {
3205 lkb->lkb_flags |= DLM_IFL_RESEND;
3206 continue;
3207 }
3208
3209 if (!waiter_needs_recovery(ls, lkb))
3210 continue;
3211
3212 switch (lkb->lkb_wait_type) {
3213
3214 case DLM_MSG_REQUEST:
3215 lkb->lkb_flags |= DLM_IFL_RESEND;
3216 break;
3217
3218 case DLM_MSG_CONVERT:
3219 recover_convert_waiter(ls, lkb);
3220 break;
3221
3222 case DLM_MSG_UNLOCK:
3223 hold_lkb(lkb);
3224 ls->ls_stub_ms.m_result = -DLM_EUNLOCK;
075529b5 3225 ls->ls_stub_ms.m_flags = lkb->lkb_flags;
e7fd4179
DT		 3226 _remove_from_waiters(lkb);
3227 _receive_unlock_reply(lkb, &ls->ls_stub_ms);
b3f58d8f 3228 dlm_put_lkb(lkb);
e7fd4179
DT		 3229 break;
3230
3231 case DLM_MSG_CANCEL:
3232 hold_lkb(lkb);
3233 ls->ls_stub_ms.m_result = -DLM_ECANCEL;
075529b5 3234 ls->ls_stub_ms.m_flags = lkb->lkb_flags;
e7fd4179
DT		 3235 _remove_from_waiters(lkb);
3236 _receive_cancel_reply(lkb, &ls->ls_stub_ms);
b3f58d8f 3237 dlm_put_lkb(lkb);
e7fd4179
DT		 3238 break;
3239
3240 default:
3241 log_error(ls, "invalid lkb wait_type %d",
3242 lkb->lkb_wait_type);
3243 }
81456807 3244 schedule();
e7fd4179 3245 }
90135925 3246 mutex_unlock(&ls->ls_waiters_mutex);
e7fd4179
DT		 3247}
3248
3249static int remove_resend_waiter(struct dlm_ls *ls, struct dlm_lkb **lkb_ret)
3250{
3251 struct dlm_lkb *lkb;
3252 int rv = 0;
3253
90135925 3254 mutex_lock(&ls->ls_waiters_mutex);
e7fd4179
DT		 3255 list_for_each_entry(lkb, &ls->ls_waiters, lkb_wait_reply) {
3256 if (lkb->lkb_flags & DLM_IFL_RESEND) {
3257 rv = lkb->lkb_wait_type;
3258 _remove_from_waiters(lkb);
3259 lkb->lkb_flags &= ~DLM_IFL_RESEND;
3260 break;
3261 }
3262 }
90135925 3263 mutex_unlock(&ls->ls_waiters_mutex);
e7fd4179
DT		 3264
3265 if (!rv)
3266 lkb = NULL;
3267 *lkb_ret = lkb;
3268 return rv;
3269}
3270
3271/* Deal with lookups and lkb's marked RESEND from _pre. We may now be the
3272 master or dir-node for r. Processing the lkb may result in it being placed
3273 back on waiters. */
3274
3275int dlm_recover_waiters_post(struct dlm_ls *ls)
3276{
3277 struct dlm_lkb *lkb;
3278 struct dlm_rsb *r;
3279 int error = 0, mstype;
3280
3281 while (1) {
3282 if (dlm_locking_stopped(ls)) {
3283 log_debug(ls, "recover_waiters_post aborted");
3284 error = -EINTR;
3285 break;
3286 }
3287
3288 mstype = remove_resend_waiter(ls, &lkb);
3289 if (!mstype)
3290 break;
3291
3292 r = lkb->lkb_resource;
3293
3294 log_debug(ls, "recover_waiters_post %x type %d flags %x %s",
3295 lkb->lkb_id, mstype, lkb->lkb_flags, r->res_name);
3296
3297 switch (mstype) {
3298
3299 case DLM_MSG_LOOKUP:
3300 hold_rsb(r);
3301 lock_rsb(r);
3302 _request_lock(r, lkb);
3303 if (is_master(r))
3304 confirm_master(r, 0);
3305 unlock_rsb(r);
3306 put_rsb(r);
3307 break;
3308
3309 case DLM_MSG_REQUEST:
3310 hold_rsb(r);
3311 lock_rsb(r);
3312 _request_lock(r, lkb);
fa9f0e49
DT		 3313 if (is_master(r))
3314 confirm_master(r, 0);
e7fd4179
DT		 3315 unlock_rsb(r);
3316 put_rsb(r);
3317 break;
3318
3319 case DLM_MSG_CONVERT:
3320 hold_rsb(r);
3321 lock_rsb(r);
3322 _convert_lock(r, lkb);
3323 unlock_rsb(r);
3324 put_rsb(r);
3325 break;
3326
3327 default:
3328 log_error(ls, "recover_waiters_post type %d", mstype);
3329 }
3330 }
3331
3332 return error;
3333}
3334
3335static void purge_queue(struct dlm_rsb *r, struct list_head *queue,
3336 int (*test)(struct dlm_ls *ls, struct dlm_lkb *lkb))
3337{
3338 struct dlm_ls *ls = r->res_ls;
3339 struct dlm_lkb *lkb, *safe;
3340
3341 list_for_each_entry_safe(lkb, safe, queue, lkb_statequeue) {
3342 if (test(ls, lkb)) {
97a35d1e 3343 rsb_set_flag(r, RSB_LOCKS_PURGED);
e7fd4179
DT		 3344 del_lkb(r, lkb);
3345 /* this put should free the lkb */
b3f58d8f 3346 if (!dlm_put_lkb(lkb))
e7fd4179
DT		 3347 log_error(ls, "purged lkb not released");
3348 }
3349 }
3350}
3351
3352static int purge_dead_test(struct dlm_ls *ls, struct dlm_lkb *lkb)
3353{
3354 return (is_master_copy(lkb) && dlm_is_removed(ls, lkb->lkb_nodeid));
3355}
3356
3357static int purge_mstcpy_test(struct dlm_ls *ls, struct dlm_lkb *lkb)
3358{
3359 return is_master_copy(lkb);
3360}
3361
3362static void purge_dead_locks(struct dlm_rsb *r)
3363{
3364 purge_queue(r, &r->res_grantqueue, &purge_dead_test);
3365 purge_queue(r, &r->res_convertqueue, &purge_dead_test);
3366 purge_queue(r, &r->res_waitqueue, &purge_dead_test);
3367}
3368
3369void dlm_purge_mstcpy_locks(struct dlm_rsb *r)
3370{
3371 purge_queue(r, &r->res_grantqueue, &purge_mstcpy_test);
3372 purge_queue(r, &r->res_convertqueue, &purge_mstcpy_test);
3373 purge_queue(r, &r->res_waitqueue, &purge_mstcpy_test);
3374}
3375
3376/* Get rid of locks held by nodes that are gone. */
3377
3378int dlm_purge_locks(struct dlm_ls *ls)
3379{
3380 struct dlm_rsb *r;
3381
3382 log_debug(ls, "dlm_purge_locks");
3383
3384 down_write(&ls->ls_root_sem);
3385 list_for_each_entry(r, &ls->ls_root_list, res_root_list) {
3386 hold_rsb(r);
3387 lock_rsb(r);
3388 if (is_master(r))
3389 purge_dead_locks(r);
3390 unlock_rsb(r);
3391 unhold_rsb(r);
3392
3393 schedule();
3394 }
3395 up_write(&ls->ls_root_sem);
3396
3397 return 0;
3398}
3399
97a35d1e
DT		 3400static struct dlm_rsb *find_purged_rsb(struct dlm_ls *ls, int bucket)
3401{
3402 struct dlm_rsb *r, *r_ret = NULL;
3403
3404 read_lock(&ls->ls_rsbtbl[bucket].lock);
3405 list_for_each_entry(r, &ls->ls_rsbtbl[bucket].list, res_hashchain) {
3406 if (!rsb_flag(r, RSB_LOCKS_PURGED))
3407 continue;
3408 hold_rsb(r);
3409 rsb_clear_flag(r, RSB_LOCKS_PURGED);
3410 r_ret = r;
3411 break;
3412 }
3413 read_unlock(&ls->ls_rsbtbl[bucket].lock);
3414 return r_ret;
3415}
3416
3417void dlm_grant_after_purge(struct dlm_ls *ls)
e7fd4179
DT		 3418{
3419 struct dlm_rsb *r;
2b4e926a 3420 int bucket = 0;
e7fd4179 3421
2b4e926a
DT		 3422 while (1) {
3423 r = find_purged_rsb(ls, bucket);
3424 if (!r) {
3425 if (bucket == ls->ls_rsbtbl_size - 1)
3426 break;
3427 bucket++;
97a35d1e 3428 continue;
2b4e926a 3429 }
97a35d1e
DT		 3430 lock_rsb(r);
3431 if (is_master(r)) {
3432 grant_pending_locks(r);
3433 confirm_master(r, 0);
e7fd4179 3434 }
97a35d1e
DT		 3435 unlock_rsb(r);
3436 put_rsb(r);
2b4e926a 3437 schedule();
e7fd4179 3438 }
e7fd4179
DT		 3439}
3440
3441static struct dlm_lkb *search_remid_list(struct list_head *head, int nodeid,
3442 uint32_t remid)
3443{
3444 struct dlm_lkb *lkb;
3445
3446 list_for_each_entry(lkb, head, lkb_statequeue) {
3447 if (lkb->lkb_nodeid == nodeid && lkb->lkb_remid == remid)
3448 return lkb;
3449 }
3450 return NULL;
3451}
3452
3453static struct dlm_lkb *search_remid(struct dlm_rsb *r, int nodeid,
3454 uint32_t remid)
3455{
3456 struct dlm_lkb *lkb;
3457
3458 lkb = search_remid_list(&r->res_grantqueue, nodeid, remid);
3459 if (lkb)
3460 return lkb;
3461 lkb = search_remid_list(&r->res_convertqueue, nodeid, remid);
3462 if (lkb)
3463 return lkb;
3464 lkb = search_remid_list(&r->res_waitqueue, nodeid, remid);
3465 if (lkb)
3466 return lkb;
3467 return NULL;
3468}
3469
3470static int receive_rcom_lock_args(struct dlm_ls *ls, struct dlm_lkb *lkb,
3471 struct dlm_rsb *r, struct dlm_rcom *rc)
3472{
3473 struct rcom_lock *rl = (struct rcom_lock *) rc->rc_buf;
3474 int lvblen;
3475
3476 lkb->lkb_nodeid = rc->rc_header.h_nodeid;
3477 lkb->lkb_ownpid = rl->rl_ownpid;
3478 lkb->lkb_remid = rl->rl_lkid;
3479 lkb->lkb_exflags = rl->rl_exflags;
3480 lkb->lkb_flags = rl->rl_flags & 0x0000FFFF;
3481 lkb->lkb_flags |= DLM_IFL_MSTCPY;
3482 lkb->lkb_lvbseq = rl->rl_lvbseq;
3483 lkb->lkb_rqmode = rl->rl_rqmode;
3484 lkb->lkb_grmode = rl->rl_grmode;
3485 /* don't set lkb_status because add_lkb wants to itself */
3486
3487 lkb->lkb_bastaddr = (void *) (long) (rl->rl_asts & AST_BAST);
3488 lkb->lkb_astaddr = (void *) (long) (rl->rl_asts & AST_COMP);
3489
e7fd4179
DT		 3490 if (lkb->lkb_exflags & DLM_LKF_VALBLK) {
3491 lkb->lkb_lvbptr = allocate_lvb(ls);
3492 if (!lkb->lkb_lvbptr)
3493 return -ENOMEM;
3494 lvblen = rc->rc_header.h_length - sizeof(struct dlm_rcom) -
3495 sizeof(struct rcom_lock);
3496 memcpy(lkb->lkb_lvbptr, rl->rl_lvb, lvblen);
3497 }
3498
3499 /* Conversions between PR and CW (middle modes) need special handling.
3500 The real granted mode of these converting locks cannot be determined
3501 until all locks have been rebuilt on the rsb (recover_conversion) */
3502
3503 if (rl->rl_wait_type == DLM_MSG_CONVERT && middle_conversion(lkb)) {
3504 rl->rl_status = DLM_LKSTS_CONVERT;
3505 lkb->lkb_grmode = DLM_LOCK_IV;
3506 rsb_set_flag(r, RSB_RECOVER_CONVERT);
3507 }
3508
3509 return 0;
3510}
3511
3512/* This lkb may have been recovered in a previous aborted recovery so we need
3513 to check if the rsb already has an lkb with the given remote nodeid/lkid.
3514 If so we just send back a standard reply. If not, we create a new lkb with
3515 the given values and send back our lkid. We send back our lkid by sending
3516 back the rcom_lock struct we got but with the remid field filled in. */
3517
3518int dlm_recover_master_copy(struct dlm_ls *ls, struct dlm_rcom *rc)
3519{
3520 struct rcom_lock *rl = (struct rcom_lock *) rc->rc_buf;
3521 struct dlm_rsb *r;
3522 struct dlm_lkb *lkb;
3523 int error;
3524
3525 if (rl->rl_parent_lkid) {
3526 error = -EOPNOTSUPP;
3527 goto out;
3528 }
3529
3530 error = find_rsb(ls, rl->rl_name, rl->rl_namelen, R_MASTER, &r);
3531 if (error)
3532 goto out;
3533
3534 lock_rsb(r);
3535
3536 lkb = search_remid(r, rc->rc_header.h_nodeid, rl->rl_lkid);
3537 if (lkb) {
3538 error = -EEXIST;
3539 goto out_remid;
3540 }
3541
3542 error = create_lkb(ls, &lkb);
3543 if (error)
3544 goto out_unlock;
3545
3546 error = receive_rcom_lock_args(ls, lkb, r, rc);
3547 if (error) {
b3f58d8f 3548 __put_lkb(ls, lkb);
e7fd4179
DT		 3549 goto out_unlock;
3550 }
3551
3552 attach_lkb(r, lkb);
3553 add_lkb(r, lkb, rl->rl_status);
3554 error = 0;
3555
3556 out_remid:
3557 /* this is the new value returned to the lock holder for
3558 saving in its process-copy lkb */
3559 rl->rl_remid = lkb->lkb_id;
3560
3561 out_unlock:
3562 unlock_rsb(r);
3563 put_rsb(r);
3564 out:
3565 if (error)
3566 log_print("recover_master_copy %d %x", error, rl->rl_lkid);
3567 rl->rl_result = error;
3568 return error;
3569}
3570
3571int dlm_recover_process_copy(struct dlm_ls *ls, struct dlm_rcom *rc)
3572{
3573 struct rcom_lock *rl = (struct rcom_lock *) rc->rc_buf;
3574 struct dlm_rsb *r;
3575 struct dlm_lkb *lkb;
3576 int error;
3577
3578 error = find_lkb(ls, rl->rl_lkid, &lkb);
3579 if (error) {
3580 log_error(ls, "recover_process_copy no lkid %x", rl->rl_lkid);
3581 return error;
3582 }
3583
3584 DLM_ASSERT(is_process_copy(lkb), dlm_print_lkb(lkb););
3585
3586 error = rl->rl_result;
3587
3588 r = lkb->lkb_resource;
3589 hold_rsb(r);
3590 lock_rsb(r);
3591
3592 switch (error) {
dc200a88
DT		 3593 case -EBADR:
3594 /* There's a chance the new master received our lock before
3595 dlm_recover_master_reply(), this wouldn't happen if we did
3596 a barrier between recover_masters and recover_locks. */
3597 log_debug(ls, "master copy not ready %x r %lx %s", lkb->lkb_id,
3598 (unsigned long)r, r->res_name);
3599 dlm_send_rcom_lock(r, lkb);
3600 goto out;
e7fd4179
DT		 3601 case -EEXIST:
3602 log_debug(ls, "master copy exists %x", lkb->lkb_id);
3603 /* fall through */
3604 case 0:
3605 lkb->lkb_remid = rl->rl_remid;
3606 break;
3607 default:
3608 log_error(ls, "dlm_recover_process_copy unknown error %d %x",
3609 error, lkb->lkb_id);
3610 }
3611
3612 /* an ack for dlm_recover_locks() which waits for replies from
3613 all the locks it sends to new masters */
3614 dlm_recovered_lock(r);
dc200a88 3615 out:
e7fd4179
DT		 3616 unlock_rsb(r);
3617 put_rsb(r);
b3f58d8f 3618 dlm_put_lkb(lkb);
e7fd4179
DT		 3619
3620 return 0;
3621}
3622
597d0cae
DT		 3623int dlm_user_request(struct dlm_ls *ls, struct dlm_user_args *ua,
3624 int mode, uint32_t flags, void *name, unsigned int namelen,
3625 uint32_t parent_lkid)
3626{
3627 struct dlm_lkb *lkb;
3628 struct dlm_args args;
3629 int error;
3630
3631 lock_recovery(ls);
3632
3633 error = create_lkb(ls, &lkb);
3634 if (error) {
3635 kfree(ua);
3636 goto out;
3637 }
3638
3639 if (flags & DLM_LKF_VALBLK) {
3640 ua->lksb.sb_lvbptr = kmalloc(DLM_USER_LVB_LEN, GFP_KERNEL);
3641 if (!ua->lksb.sb_lvbptr) {
3642 kfree(ua);
3643 __put_lkb(ls, lkb);
3644 error = -ENOMEM;
3645 goto out;
3646 }
3647 }
3648
3649 /* After ua is attached to lkb it will be freed by free_lkb().
3650 When DLM_IFL_USER is set, the dlm knows that this is a userspace
3651 lock and that lkb_astparam is the dlm_user_args structure. */
3652
3653 error = set_lock_args(mode, &ua->lksb, flags, namelen, parent_lkid,
32f105a1 3654 DLM_FAKE_USER_AST, ua, DLM_FAKE_USER_AST, &args);
597d0cae
DT		 3655 lkb->lkb_flags |= DLM_IFL_USER;
3656 ua->old_mode = DLM_LOCK_IV;
3657
3658 if (error) {
3659 __put_lkb(ls, lkb);
3660 goto out;
3661 }
3662
3663 error = request_lock(ls, lkb, name, namelen, &args);
3664
3665 switch (error) {
3666 case 0:
3667 break;
3668 case -EINPROGRESS:
3669 error = 0;
3670 break;
3671 case -EAGAIN:
3672 error = 0;
3673 /* fall through */
3674 default:
3675 __put_lkb(ls, lkb);
3676 goto out;
3677 }
3678
3679 /* add this new lkb to the per-process list of locks */
3680 spin_lock(&ua->proc->locks_spin);
3681 kref_get(&lkb->lkb_ref);
3682 list_add_tail(&lkb->lkb_ownqueue, &ua->proc->locks);
3683 spin_unlock(&ua->proc->locks_spin);
3684 out:
3685 unlock_recovery(ls);
3686 return error;
3687}
3688
3689int dlm_user_convert(struct dlm_ls *ls, struct dlm_user_args *ua_tmp,
3690 int mode, uint32_t flags, uint32_t lkid, char *lvb_in)
3691{
3692 struct dlm_lkb *lkb;
3693 struct dlm_args args;
3694 struct dlm_user_args *ua;
3695 int error;
3696
3697 lock_recovery(ls);
3698
3699 error = find_lkb(ls, lkid, &lkb);
3700 if (error)
3701 goto out;
3702
3703 /* user can change the params on its lock when it converts it, or
3704 add an lvb that didn't exist before */
3705
3706 ua = (struct dlm_user_args *)lkb->lkb_astparam;
3707
3708 if (flags & DLM_LKF_VALBLK && !ua->lksb.sb_lvbptr) {
3709 ua->lksb.sb_lvbptr = kmalloc(DLM_USER_LVB_LEN, GFP_KERNEL);
3710 if (!ua->lksb.sb_lvbptr) {
3711 error = -ENOMEM;
3712 goto out_put;
3713 }
3714 }
3715 if (lvb_in && ua->lksb.sb_lvbptr)
3716 memcpy(ua->lksb.sb_lvbptr, lvb_in, DLM_USER_LVB_LEN);
3717
3718 ua->castparam = ua_tmp->castparam;
3719 ua->castaddr = ua_tmp->castaddr;
3720 ua->bastparam = ua_tmp->bastparam;
3721 ua->bastaddr = ua_tmp->bastaddr;
10948eb4 3722 ua->user_lksb = ua_tmp->user_lksb;
597d0cae
DT		 3723 ua->old_mode = lkb->lkb_grmode;
3724
32f105a1
DT		 3725 error = set_lock_args(mode, &ua->lksb, flags, 0, 0, DLM_FAKE_USER_AST,
3726 ua, DLM_FAKE_USER_AST, &args);
597d0cae
DT		 3727 if (error)
3728 goto out_put;
3729
3730 error = convert_lock(ls, lkb, &args);
3731
3732 if (error == -EINPROGRESS || error == -EAGAIN)
3733 error = 0;
3734 out_put:
3735 dlm_put_lkb(lkb);
3736 out:
3737 unlock_recovery(ls);
3738 kfree(ua_tmp);
3739 return error;
3740}
3741
3742int dlm_user_unlock(struct dlm_ls *ls, struct dlm_user_args *ua_tmp,
3743 uint32_t flags, uint32_t lkid, char *lvb_in)
3744{
3745 struct dlm_lkb *lkb;
3746 struct dlm_args args;
3747 struct dlm_user_args *ua;
3748 int error;
3749
3750 lock_recovery(ls);
3751
3752 error = find_lkb(ls, lkid, &lkb);
3753 if (error)
3754 goto out;
3755
3756 ua = (struct dlm_user_args *)lkb->lkb_astparam;
3757
3758 if (lvb_in && ua->lksb.sb_lvbptr)
3759 memcpy(ua->lksb.sb_lvbptr, lvb_in, DLM_USER_LVB_LEN);
3760 ua->castparam = ua_tmp->castparam;
cc346d55 3761 ua->user_lksb = ua_tmp->user_lksb;
597d0cae
DT		 3762
3763 error = set_unlock_args(flags, ua, &args);
3764 if (error)
3765 goto out_put;
3766
3767 error = unlock_lock(ls, lkb, &args);
3768
3769 if (error == -DLM_EUNLOCK)
3770 error = 0;
3771 if (error)
3772 goto out_put;
3773
3774 spin_lock(&ua->proc->locks_spin);
34e22bed 3775 list_del_init(&lkb->lkb_ownqueue);
597d0cae
DT		 3776 spin_unlock(&ua->proc->locks_spin);
3777
3778 /* this removes the reference for the proc->locks list added by
3779 dlm_user_request */
3780 unhold_lkb(lkb);
3781 out_put:
3782 dlm_put_lkb(lkb);
3783 out:
3784 unlock_recovery(ls);
3785 return error;
3786}
3787
3788int dlm_user_cancel(struct dlm_ls *ls, struct dlm_user_args *ua_tmp,
3789 uint32_t flags, uint32_t lkid)
3790{
3791 struct dlm_lkb *lkb;
3792 struct dlm_args args;
3793 struct dlm_user_args *ua;
3794 int error;
3795
3796 lock_recovery(ls);
3797
3798 error = find_lkb(ls, lkid, &lkb);
3799 if (error)
3800 goto out;
3801
3802 ua = (struct dlm_user_args *)lkb->lkb_astparam;
3803 ua->castparam = ua_tmp->castparam;
c059f70e 3804 ua->user_lksb = ua_tmp->user_lksb;
597d0cae
DT		 3805
3806 error = set_unlock_args(flags, ua, &args);
3807 if (error)
3808 goto out_put;
3809
3810 error = cancel_lock(ls, lkb, &args);
3811
3812 if (error == -DLM_ECANCEL)
3813 error = 0;
3814 if (error)
3815 goto out_put;
3816
3817 /* this lkb was removed from the WAITING queue */
3818 if (lkb->lkb_grmode == DLM_LOCK_IV) {
3819 spin_lock(&ua->proc->locks_spin);
34e22bed 3820 list_del_init(&lkb->lkb_ownqueue);
597d0cae
DT		 3821 spin_unlock(&ua->proc->locks_spin);
3822 unhold_lkb(lkb);
3823 }
3824 out_put:
3825 dlm_put_lkb(lkb);
3826 out:
3827 unlock_recovery(ls);
3828 return error;
3829}
3830
3831static int orphan_proc_lock(struct dlm_ls *ls, struct dlm_lkb *lkb)
3832{
3833 struct dlm_user_args *ua = (struct dlm_user_args *)lkb->lkb_astparam;
3834
3835 if (ua->lksb.sb_lvbptr)
3836 kfree(ua->lksb.sb_lvbptr);
3837 kfree(ua);
3838 lkb->lkb_astparam = (long)NULL;
3839
3840 /* TODO: propogate to master if needed */
3841 return 0;
3842}
3843
3844/* The force flag allows the unlock to go ahead even if the lkb isn't granted.
3845 Regardless of what rsb queue the lock is on, it's removed and freed. */
3846
3847static int unlock_proc_lock(struct dlm_ls *ls, struct dlm_lkb *lkb)
3848{
3849 struct dlm_user_args *ua = (struct dlm_user_args *)lkb->lkb_astparam;
3850 struct dlm_args args;
3851 int error;
3852
3853 /* FIXME: we need to handle the case where the lkb is in limbo
3854 while the rsb is being looked up, currently we assert in
3855 _unlock_lock/is_remote because rsb nodeid is -1. */
3856
3857 set_unlock_args(DLM_LKF_FORCEUNLOCK, ua, &args);
3858
3859 error = unlock_lock(ls, lkb, &args);
3860 if (error == -DLM_EUNLOCK)
3861 error = 0;
3862 return error;
3863}
3864
3865/* The ls_clear_proc_locks mutex protects against dlm_user_add_asts() which
3866 1) references lkb->ua which we free here and 2) adds lkbs to proc->asts,
3867 which we clear here. */
3868
3869/* proc CLOSING flag is set so no more device_reads should look at proc->asts
3870 list, and no more device_writes should add lkb's to proc->locks list; so we
3871 shouldn't need to take asts_spin or locks_spin here. this assumes that
3872 device reads/writes/closes are serialized -- FIXME: we may need to serialize
3873 them ourself. */
3874
3875void dlm_clear_proc_locks(struct dlm_ls *ls, struct dlm_user_proc *proc)
3876{
3877 struct dlm_lkb *lkb, *safe;
3878
3879 lock_recovery(ls);
3880 mutex_lock(&ls->ls_clear_proc_locks);
3881
3882 list_for_each_entry_safe(lkb, safe, &proc->locks, lkb_ownqueue) {
3883 if (lkb->lkb_ast_type) {
3884 list_del(&lkb->lkb_astqueue);
3885 unhold_lkb(lkb);
3886 }
3887
34e22bed 3888 list_del_init(&lkb->lkb_ownqueue);
597d0cae
DT		 3889
3890 if (lkb->lkb_exflags & DLM_LKF_PERSISTENT) {
3891 lkb->lkb_flags |= DLM_IFL_ORPHAN;
3892 orphan_proc_lock(ls, lkb);
3893 } else {
3894 lkb->lkb_flags |= DLM_IFL_DEAD;
3895 unlock_proc_lock(ls, lkb);
3896 }
3897
3898 /* this removes the reference for the proc->locks list
3899 added by dlm_user_request, it may result in the lkb
3900 being freed */
3901
3902 dlm_put_lkb(lkb);
3903 }
3904 mutex_unlock(&ls->ls_clear_proc_locks);
3905 unlock_recovery(ls);
3906}
Linux kernel - Deliverables
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