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[hh.org.git] / fs / dlm / lock.c
blob3f2befa4797b9a983914dfc16b84c2f3bf852481
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 */
58 #include <linux/types.h>
59 #include "dlm_internal.h"
60 #include <linux/dlm_device.h>
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"
73 #include "user.h"
74 #include "config.h"
75
76 static int send_request(struct dlm_rsb *r, struct dlm_lkb *lkb);
77 static int send_convert(struct dlm_rsb *r, struct dlm_lkb *lkb);
78 static int send_unlock(struct dlm_rsb *r, struct dlm_lkb *lkb);
79 static int send_cancel(struct dlm_rsb *r, struct dlm_lkb *lkb);
80 static int send_grant(struct dlm_rsb *r, struct dlm_lkb *lkb);
81 static int send_bast(struct dlm_rsb *r, struct dlm_lkb *lkb, int mode);
82 static int send_lookup(struct dlm_rsb *r, struct dlm_lkb *lkb);
83 static int send_remove(struct dlm_rsb *r);
84 static int _request_lock(struct dlm_rsb *r, struct dlm_lkb *lkb);
85 static void __receive_convert_reply(struct dlm_rsb *r, struct dlm_lkb *lkb,
86 struct dlm_message *ms);
87 static 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
97 static 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
118 const 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 };
129
130 #define modes_compat(gr, rq) \
131 __dlm_compat_matrix[(gr)->lkb_grmode + 1][(rq)->lkb_rqmode + 1]
132
133 int 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
144 static 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
156 void dlm_print_lkb(struct dlm_lkb *lkb)
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
165 void 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
172 void 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
194 /* Threads cannot use the lockspace while it's being recovered */
195
196 static inline void lock_recovery(struct dlm_ls *ls)
197 {
198 down_read(&ls->ls_in_recovery);
199 }
200
201 static inline void unlock_recovery(struct dlm_ls *ls)
202 {
203 up_read(&ls->ls_in_recovery);
204 }
205
206 static inline int lock_recovery_try(struct dlm_ls *ls)
207 {
208 return down_read_trylock(&ls->ls_in_recovery);
209 }
210
211 static inline int can_be_queued(struct dlm_lkb *lkb)
212 {
213 return !(lkb->lkb_exflags & DLM_LKF_NOQUEUE);
214 }
215
216 static inline int force_blocking_asts(struct dlm_lkb *lkb)
217 {
218 return (lkb->lkb_exflags & DLM_LKF_NOQUEUEBAST);
219 }
220
221 static inline int is_demoted(struct dlm_lkb *lkb)
222 {
223 return (lkb->lkb_sbflags & DLM_SBF_DEMOTED);
224 }
225
226 static 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
232 static inline int is_process_copy(struct dlm_lkb *lkb)
233 {
234 return (lkb->lkb_nodeid && !(lkb->lkb_flags & DLM_IFL_MSTCPY));
235 }
236
237 static 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););
241 return (lkb->lkb_flags & DLM_IFL_MSTCPY) ? 1 : 0;
242 }
243
244 static 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))
248 return 1;
249 return 0;
250 }
251
252 static inline int down_conversion(struct dlm_lkb *lkb)
253 {
254 return (!middle_conversion(lkb) && lkb->lkb_rqmode < lkb->lkb_grmode);
255 }
256
257 static 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
270 static 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
284 static 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);
295 mutex_init(&r->res_mutex);
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
307 static 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 }
317 return -EBADR;
318
319 found:
320 if (r->res_nodeid && (flags & R_MASTER))
321 error = -ENOTBLK;
322 *r_ret = r;
323 return error;
324 }
325
326 static 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
361 static 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
385 static 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
402 if (error == -EBADR && !(flags & R_CREATE))
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
443 int 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
452 static inline void hold_rsb(struct dlm_rsb *r)
453 {
454 kref_get(&r->res_ref);
455 }
456
457 void dlm_hold_rsb(struct dlm_rsb *r)
458 {
459 hold_rsb(r);
460 }
461
462 static 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
480 static 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
490 void dlm_put_rsb(struct dlm_rsb *r)
491 {
492 put_rsb(r);
493 }
494
495 /* See comment for unhold_lkb */
496
497 static void unhold_rsb(struct dlm_rsb *r)
498 {
499 int rv;
500 rv = kref_put(&r->res_ref, toss_rsb);
501 DLM_ASSERT(!rv, dlm_dump_rsb(r););
502 }
503
504 static 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
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););
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
522 static void attach_lkb(struct dlm_rsb *r, struct dlm_lkb *lkb)
523 {
524 hold_rsb(r);
525 lkb->lkb_resource = r;
526 }
527
528 static 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
536 static 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);
549 INIT_LIST_HEAD(&lkb->lkb_ownqueue);
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
578 static 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
590 static 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
608 static 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
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
621 static int __put_lkb(struct dlm_ls *ls, struct dlm_lkb *lkb)
622 {
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);
635 free_lkb(lkb);
636 return 1;
637 } else {
638 write_unlock(&ls->ls_lkbtbl[bucket].lock);
639 return 0;
640 }
641 }
642
643 int dlm_put_lkb(struct dlm_lkb *lkb)
644 {
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);
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
657 static 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
667 static 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
674 static 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
691 static 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
723 static 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
730 static 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
741 static void add_to_waiters(struct dlm_lkb *lkb, int mstype)
742 {
743 struct dlm_ls *ls = lkb->lkb_resource->res_ls;
744
745 mutex_lock(&ls->ls_waiters_mutex);
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:
754 mutex_unlock(&ls->ls_waiters_mutex);
755 }
756
757 static 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
773 static int remove_from_waiters(struct dlm_lkb *lkb)
774 {
775 struct dlm_ls *ls = lkb->lkb_resource->res_ls;
776 int error;
777
778 mutex_lock(&ls->ls_waiters_mutex);
779 error = _remove_from_waiters(lkb);
780 mutex_unlock(&ls->ls_waiters_mutex);
781 return error;
782 }
783
784 static 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
802 static int shrink_bucket(struct dlm_ls *ls, int b)
803 {
804 struct dlm_rsb *r;
805 int count = 0, found;
806
807 for (;;) {
808 found = 0;
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 +
813 dlm_config.toss_secs * HZ))
814 continue;
815 found = 1;
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
841 void 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
856 static 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
907 static 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
936 static 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
947 b = dlm_lvb_operations[lkb->lkb_grmode + 1][lkb->lkb_rqmode + 1];
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
965 static 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
974 static 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
980 static void remove_lock_pc(struct dlm_rsb *r, struct dlm_lkb *lkb)
981 {
982 _remove_lock(r, lkb);
983 }
984
985 static 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) {
990 case DLM_LKSTS_GRANTED:
991 break;
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
1007 static void revert_lock_pc(struct dlm_rsb *r, struct dlm_lkb *lkb)
1008 {
1009 revert_lock(r, lkb);
1010 }
1011
1012 static 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;
1023 }
1024
1025 static 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
1032 static 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
1043 static 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
1052 static 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)
1057 return 1;
1058
1059 return 0;
1060 }
1061
1062 /* Check if the given lkb conflicts with another lkb on the queue. */
1063
1064 static 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;
1071 if (!modes_compat(this, lkb))
1072 return 1;
1073 }
1074 return 0;
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
1102 static 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
1114 if (!modes_compat(this, lkb) && !modes_compat(lkb, this))
1115 return 1;
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))
1126 return 1;
1127 }
1128
1129 return 0;
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
1145 static 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)
1169 return 1;
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))
1212 return 1;
1213
1214 /*
1215 * The NOORDER flag is set to avoid the standard vms rules on grant
1216 * order.
1217 */
1218
1219 if (lkb->lkb_exflags & DLM_LKF_NOORDER)
1220 return 1;
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))
1229 return 1;
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))
1244 return 1;
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))
1256 return 1;
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
1269 return 0;
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
1277 static 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
1307 static 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);
1320 if (can_be_granted(r, lkb, 0)) {
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
1340 static 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) {
1345 if (can_be_granted(r, lkb, 0))
1346 grant_lock_pending(r, lkb);
1347 else
1348 high = max_t(int, lkb->lkb_rqmode, high);
1349 }
1350
1351 return high;
1352 }
1353
1354 static void grant_pending_locks(struct dlm_rsb *r)
1355 {
1356 struct dlm_lkb *lkb, *s;
1357 int high = DLM_LOCK_IV;
1358
1359 DLM_ASSERT(is_master(r), dlm_dump_rsb(r););
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)
1370 * found above. FIXME: highbast < high comparison not valid for PR/CW.
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
1382 static 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 &&
1390 !modes_compat(gr, lkb)) {
1391 queue_bast(r, gr, lkb->lkb_rqmode);
1392 gr->lkb_highbast = lkb->lkb_rqmode;
1393 }
1394 }
1395 }
1396
1397 static void send_blocking_asts(struct dlm_rsb *r, struct dlm_lkb *lkb)
1398 {
1399 send_bast_queue(r, &r->res_grantqueue, lkb);
1400 }
1401
1402 static 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
1427 static 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
1454 DLM_ASSERT(r->res_nodeid == -1, dlm_dump_rsb(r););
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
1491 static 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
1504 static 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
1539 static int set_lock_args(int mode, struct dlm_lksb *lksb, uint32_t flags,
1540 int namelen, uint32_t parent_lkid, void *ast,
1541 void *astarg, void *bast, struct dlm_args *args)
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;
1600 rv = 0;
1601 out:
1602 return rv;
1603 }
1604
1605 static 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
1616 static 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;
1646 rv = 0;
1647 out:
1648 return rv;
1649 }
1650
1651 static 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
1690 static int do_request(struct dlm_rsb *r, struct dlm_lkb *lkb)
1691 {
1692 int error = 0;
1693
1694 if (can_be_granted(r, lkb, 1)) {
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
1716 static 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
1722 if (can_be_granted(r, lkb, 1)) {
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
1748 static 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
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. */
1760
1761 static 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
1776 static 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
1799 /* change some property of an existing lkb, e.g. mode */
1800
1801 static 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
1816 static 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
1831 static 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
1849 static 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
1877 static 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
1899 static 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
1921 static 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
1947 int 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,
1956 void (*bast) (void *astarg, int mode))
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,
1978 astarg, bast, &args);
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)
1991 __put_lkb(ls, lkb);
1992 if (error == -EAGAIN)
1993 error = 0;
1994 out:
1995 unlock_recovery(ls);
1996 dlm_put_lockspace(ls);
1997 return error;
1998 }
1999
2000 int 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:
2033 dlm_put_lkb(lkb);
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
2062 static 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
2116 static 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
2123 static 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
2147 if (ms->m_type == DLM_MSG_REQUEST || ms->m_type == DLM_MSG_LOOKUP)
2148 memcpy(ms->m_extra, r->res_name, r->res_length);
2149
2150 else if (lkb->lkb_lvbptr)
2151 memcpy(ms->m_extra, lkb->lkb_lvbptr, r->res_ls->ls_lvblen);
2152
2153 }
2154
2155 static int send_common(struct dlm_rsb *r, struct dlm_lkb *lkb, int mstype)
2156 {
2157 struct dlm_message *ms;
2158 struct dlm_mhandle *mh;
2159 int to_nodeid, error;
2160
2161 add_to_waiters(lkb, mstype);
2162
2163 to_nodeid = r->res_nodeid;
2164
2165 error = create_message(r, lkb, to_nodeid, mstype, &ms, &mh);
2166 if (error)
2167 goto fail;
2168
2169 send_args(r, lkb, ms);
2170
2171 error = send_message(mh, ms);
2172 if (error)
2173 goto fail;
2174 return 0;
2175
2176 fail:
2177 remove_from_waiters(lkb);
2178 return error;
2179 }
2180
2181 static int send_request(struct dlm_rsb *r, struct dlm_lkb *lkb)
2182 {
2183 return send_common(r, lkb, DLM_MSG_REQUEST);
2184 }
2185
2186 static int send_convert(struct dlm_rsb *r, struct dlm_lkb *lkb)
2187 {
2188 int error;
2189
2190 error = send_common(r, lkb, DLM_MSG_CONVERT);
2191
2192 /* down conversions go without a reply from the master */
2193 if (!error && down_conversion(lkb)) {
2194 remove_from_waiters(lkb);
2195 r->res_ls->ls_stub_ms.m_result = 0;
2196 r->res_ls->ls_stub_ms.m_flags = lkb->lkb_flags;
2197 __receive_convert_reply(r, lkb, &r->res_ls->ls_stub_ms);
2198 }
2199
2200 return error;
2201 }
2202
2203 /* FIXME: if this lkb is the only lock we hold on the rsb, then set
2204 MASTER_UNCERTAIN to force the next request on the rsb to confirm
2205 that the master is still correct. */
2206
2207 static int send_unlock(struct dlm_rsb *r, struct dlm_lkb *lkb)
2208 {
2209 return send_common(r, lkb, DLM_MSG_UNLOCK);
2210 }
2211
2212 static int send_cancel(struct dlm_rsb *r, struct dlm_lkb *lkb)
2213 {
2214 return send_common(r, lkb, DLM_MSG_CANCEL);
2215 }
2216
2217 static int send_grant(struct dlm_rsb *r, struct dlm_lkb *lkb)
2218 {
2219 struct dlm_message *ms;
2220 struct dlm_mhandle *mh;
2221 int to_nodeid, error;
2222
2223 to_nodeid = lkb->lkb_nodeid;
2224
2225 error = create_message(r, lkb, to_nodeid, DLM_MSG_GRANT, &ms, &mh);
2226 if (error)
2227 goto out;
2228
2229 send_args(r, lkb, ms);
2230
2231 ms->m_result = 0;
2232
2233 error = send_message(mh, ms);
2234 out:
2235 return error;
2236 }
2237
2238 static int send_bast(struct dlm_rsb *r, struct dlm_lkb *lkb, int mode)
2239 {
2240 struct dlm_message *ms;
2241 struct dlm_mhandle *mh;
2242 int to_nodeid, error;
2243
2244 to_nodeid = lkb->lkb_nodeid;
2245
2246 error = create_message(r, NULL, to_nodeid, DLM_MSG_BAST, &ms, &mh);
2247 if (error)
2248 goto out;
2249
2250 send_args(r, lkb, ms);
2251
2252 ms->m_bastmode = mode;
2253
2254 error = send_message(mh, ms);
2255 out:
2256 return error;
2257 }
2258
2259 static int send_lookup(struct dlm_rsb *r, struct dlm_lkb *lkb)
2260 {
2261 struct dlm_message *ms;
2262 struct dlm_mhandle *mh;
2263 int to_nodeid, error;
2264
2265 add_to_waiters(lkb, DLM_MSG_LOOKUP);
2266
2267 to_nodeid = dlm_dir_nodeid(r);
2268
2269 error = create_message(r, NULL, to_nodeid, DLM_MSG_LOOKUP, &ms, &mh);
2270 if (error)
2271 goto fail;
2272
2273 send_args(r, lkb, ms);
2274
2275 error = send_message(mh, ms);
2276 if (error)
2277 goto fail;
2278 return 0;
2279
2280 fail:
2281 remove_from_waiters(lkb);
2282 return error;
2283 }
2284
2285 static int send_remove(struct dlm_rsb *r)
2286 {
2287 struct dlm_message *ms;
2288 struct dlm_mhandle *mh;
2289 int to_nodeid, error;
2290
2291 to_nodeid = dlm_dir_nodeid(r);
2292
2293 error = create_message(r, NULL, to_nodeid, DLM_MSG_REMOVE, &ms, &mh);
2294 if (error)
2295 goto out;
2296
2297 memcpy(ms->m_extra, r->res_name, r->res_length);
2298 ms->m_hash = r->res_hash;
2299
2300 error = send_message(mh, ms);
2301 out:
2302 return error;
2303 }
2304
2305 static int send_common_reply(struct dlm_rsb *r, struct dlm_lkb *lkb,
2306 int mstype, int rv)
2307 {
2308 struct dlm_message *ms;
2309 struct dlm_mhandle *mh;
2310 int to_nodeid, error;
2311
2312 to_nodeid = lkb->lkb_nodeid;
2313
2314 error = create_message(r, lkb, to_nodeid, mstype, &ms, &mh);
2315 if (error)
2316 goto out;
2317
2318 send_args(r, lkb, ms);
2319
2320 ms->m_result = rv;
2321
2322 error = send_message(mh, ms);
2323 out:
2324 return error;
2325 }
2326
2327 static int send_request_reply(struct dlm_rsb *r, struct dlm_lkb *lkb, int rv)
2328 {
2329 return send_common_reply(r, lkb, DLM_MSG_REQUEST_REPLY, rv);
2330 }
2331
2332 static int send_convert_reply(struct dlm_rsb *r, struct dlm_lkb *lkb, int rv)
2333 {
2334 return send_common_reply(r, lkb, DLM_MSG_CONVERT_REPLY, rv);
2335 }
2336
2337 static int send_unlock_reply(struct dlm_rsb *r, struct dlm_lkb *lkb, int rv)
2338 {
2339 return send_common_reply(r, lkb, DLM_MSG_UNLOCK_REPLY, rv);
2340 }
2341
2342 static int send_cancel_reply(struct dlm_rsb *r, struct dlm_lkb *lkb, int rv)
2343 {
2344 return send_common_reply(r, lkb, DLM_MSG_CANCEL_REPLY, rv);
2345 }
2346
2347 static int send_lookup_reply(struct dlm_ls *ls, struct dlm_message *ms_in,
2348 int ret_nodeid, int rv)
2349 {
2350 struct dlm_rsb *r = &ls->ls_stub_rsb;
2351 struct dlm_message *ms;
2352 struct dlm_mhandle *mh;
2353 int error, nodeid = ms_in->m_header.h_nodeid;
2354
2355 error = create_message(r, NULL, nodeid, DLM_MSG_LOOKUP_REPLY, &ms, &mh);
2356 if (error)
2357 goto out;
2358
2359 ms->m_lkid = ms_in->m_lkid;
2360 ms->m_result = rv;
2361 ms->m_nodeid = ret_nodeid;
2362
2363 error = send_message(mh, ms);
2364 out:
2365 return error;
2366 }
2367
2368 /* which args we save from a received message depends heavily on the type
2369 of message, unlike the send side where we can safely send everything about
2370 the lkb for any type of message */
2371
2372 static void receive_flags(struct dlm_lkb *lkb, struct dlm_message *ms)
2373 {
2374 lkb->lkb_exflags = ms->m_exflags;
2375 lkb->lkb_flags = (lkb->lkb_flags & 0xFFFF0000) |
2376 (ms->m_flags & 0x0000FFFF);
2377 }
2378
2379 static void receive_flags_reply(struct dlm_lkb *lkb, struct dlm_message *ms)
2380 {
2381 lkb->lkb_sbflags = ms->m_sbflags;
2382 lkb->lkb_flags = (lkb->lkb_flags & 0xFFFF0000) |
2383 (ms->m_flags & 0x0000FFFF);
2384 }
2385
2386 static int receive_extralen(struct dlm_message *ms)
2387 {
2388 return (ms->m_header.h_length - sizeof(struct dlm_message));
2389 }
2390
2391 static int receive_lvb(struct dlm_ls *ls, struct dlm_lkb *lkb,
2392 struct dlm_message *ms)
2393 {
2394 int len;
2395
2396 if (lkb->lkb_exflags & DLM_LKF_VALBLK) {
2397 if (!lkb->lkb_lvbptr)
2398 lkb->lkb_lvbptr = allocate_lvb(ls);
2399 if (!lkb->lkb_lvbptr)
2400 return -ENOMEM;
2401 len = receive_extralen(ms);
2402 memcpy(lkb->lkb_lvbptr, ms->m_extra, len);
2403 }
2404 return 0;
2405 }
2406
2407 static int receive_request_args(struct dlm_ls *ls, struct dlm_lkb *lkb,
2408 struct dlm_message *ms)
2409 {
2410 lkb->lkb_nodeid = ms->m_header.h_nodeid;
2411 lkb->lkb_ownpid = ms->m_pid;
2412 lkb->lkb_remid = ms->m_lkid;
2413 lkb->lkb_grmode = DLM_LOCK_IV;
2414 lkb->lkb_rqmode = ms->m_rqmode;
2415 lkb->lkb_bastaddr = (void *) (long) (ms->m_asts & AST_BAST);
2416 lkb->lkb_astaddr = (void *) (long) (ms->m_asts & AST_COMP);
2417
2418 DLM_ASSERT(is_master_copy(lkb), dlm_print_lkb(lkb););
2419
2420 if (receive_lvb(ls, lkb, ms))
2421 return -ENOMEM;
2422
2423 return 0;
2424 }
2425
2426 static int receive_convert_args(struct dlm_ls *ls, struct dlm_lkb *lkb,
2427 struct dlm_message *ms)
2428 {
2429 if (lkb->lkb_nodeid != ms->m_header.h_nodeid) {
2430 log_error(ls, "convert_args nodeid %d %d lkid %x %x",
2431 lkb->lkb_nodeid, ms->m_header.h_nodeid,
2432 lkb->lkb_id, lkb->lkb_remid);
2433 return -EINVAL;
2434 }
2435
2436 if (!is_master_copy(lkb))
2437 return -EINVAL;
2438
2439 if (lkb->lkb_status != DLM_LKSTS_GRANTED)
2440 return -EBUSY;
2441
2442 if (receive_lvb(ls, lkb, ms))
2443 return -ENOMEM;
2444
2445 lkb->lkb_rqmode = ms->m_rqmode;
2446 lkb->lkb_lvbseq = ms->m_lvbseq;
2447
2448 return 0;
2449 }
2450
2451 static int receive_unlock_args(struct dlm_ls *ls, struct dlm_lkb *lkb,
2452 struct dlm_message *ms)
2453 {
2454 if (!is_master_copy(lkb))
2455 return -EINVAL;
2456 if (receive_lvb(ls, lkb, ms))
2457 return -ENOMEM;
2458 return 0;
2459 }
2460
2461 /* We fill in the stub-lkb fields with the info that send_xxxx_reply()
2462 uses to send a reply and that the remote end uses to process the reply. */
2463
2464 static void setup_stub_lkb(struct dlm_ls *ls, struct dlm_message *ms)
2465 {
2466 struct dlm_lkb *lkb = &ls->ls_stub_lkb;
2467 lkb->lkb_nodeid = ms->m_header.h_nodeid;
2468 lkb->lkb_remid = ms->m_lkid;
2469 }
2470
2471 static void receive_request(struct dlm_ls *ls, struct dlm_message *ms)
2472 {
2473 struct dlm_lkb *lkb;
2474 struct dlm_rsb *r;
2475 int error, namelen;
2476
2477 error = create_lkb(ls, &lkb);
2478 if (error)
2479 goto fail;
2480
2481 receive_flags(lkb, ms);
2482 lkb->lkb_flags |= DLM_IFL_MSTCPY;
2483 error = receive_request_args(ls, lkb, ms);
2484 if (error) {
2485 __put_lkb(ls, lkb);
2486 goto fail;
2487 }
2488
2489 namelen = receive_extralen(ms);
2490
2491 error = find_rsb(ls, ms->m_extra, namelen, R_MASTER, &r);
2492 if (error) {
2493 __put_lkb(ls, lkb);
2494 goto fail;
2495 }
2496
2497 lock_rsb(r);
2498
2499 attach_lkb(r, lkb);
2500 error = do_request(r, lkb);
2501 send_request_reply(r, lkb, error);
2502
2503 unlock_rsb(r);
2504 put_rsb(r);
2505
2506 if (error == -EINPROGRESS)
2507 error = 0;
2508 if (error)
2509 dlm_put_lkb(lkb);
2510 return;
2511
2512 fail:
2513 setup_stub_lkb(ls, ms);
2514 send_request_reply(&ls->ls_stub_rsb, &ls->ls_stub_lkb, error);
2515 }
2516
2517 static void receive_convert(struct dlm_ls *ls, struct dlm_message *ms)
2518 {
2519 struct dlm_lkb *lkb;
2520 struct dlm_rsb *r;
2521 int error, reply = 1;
2522
2523 error = find_lkb(ls, ms->m_remid, &lkb);
2524 if (error)
2525 goto fail;
2526
2527 r = lkb->lkb_resource;
2528
2529 hold_rsb(r);
2530 lock_rsb(r);
2531
2532 receive_flags(lkb, ms);
2533 error = receive_convert_args(ls, lkb, ms);
2534 if (error)
2535 goto out;
2536 reply = !down_conversion(lkb);
2537
2538 error = do_convert(r, lkb);
2539 out:
2540 if (reply)
2541 send_convert_reply(r, lkb, error);
2542
2543 unlock_rsb(r);
2544 put_rsb(r);
2545 dlm_put_lkb(lkb);
2546 return;
2547
2548 fail:
2549 setup_stub_lkb(ls, ms);
2550 send_convert_reply(&ls->ls_stub_rsb, &ls->ls_stub_lkb, error);
2551 }
2552
2553 static void receive_unlock(struct dlm_ls *ls, struct dlm_message *ms)
2554 {
2555 struct dlm_lkb *lkb;
2556 struct dlm_rsb *r;
2557 int error;
2558
2559 error = find_lkb(ls, ms->m_remid, &lkb);
2560 if (error)
2561 goto fail;
2562
2563 r = lkb->lkb_resource;
2564
2565 hold_rsb(r);
2566 lock_rsb(r);
2567
2568 receive_flags(lkb, ms);
2569 error = receive_unlock_args(ls, lkb, ms);
2570 if (error)
2571 goto out;
2572
2573 error = do_unlock(r, lkb);
2574 out:
2575 send_unlock_reply(r, lkb, error);
2576
2577 unlock_rsb(r);
2578 put_rsb(r);
2579 dlm_put_lkb(lkb);
2580 return;
2581
2582 fail:
2583 setup_stub_lkb(ls, ms);
2584 send_unlock_reply(&ls->ls_stub_rsb, &ls->ls_stub_lkb, error);
2585 }
2586
2587 static void receive_cancel(struct dlm_ls *ls, struct dlm_message *ms)
2588 {
2589 struct dlm_lkb *lkb;
2590 struct dlm_rsb *r;
2591 int error;
2592
2593 error = find_lkb(ls, ms->m_remid, &lkb);
2594 if (error)
2595 goto fail;
2596
2597 receive_flags(lkb, ms);
2598
2599 r = lkb->lkb_resource;
2600
2601 hold_rsb(r);
2602 lock_rsb(r);
2603
2604 error = do_cancel(r, lkb);
2605 send_cancel_reply(r, lkb, error);
2606
2607 unlock_rsb(r);
2608 put_rsb(r);
2609 dlm_put_lkb(lkb);
2610 return;
2611
2612 fail:
2613 setup_stub_lkb(ls, ms);
2614 send_cancel_reply(&ls->ls_stub_rsb, &ls->ls_stub_lkb, error);
2615 }
2616
2617 static void receive_grant(struct dlm_ls *ls, struct dlm_message *ms)
2618 {
2619 struct dlm_lkb *lkb;
2620 struct dlm_rsb *r;
2621 int error;
2622
2623 error = find_lkb(ls, ms->m_remid, &lkb);
2624 if (error) {
2625 log_error(ls, "receive_grant no lkb");
2626 return;
2627 }
2628 DLM_ASSERT(is_process_copy(lkb), dlm_print_lkb(lkb););
2629
2630 r = lkb->lkb_resource;
2631
2632 hold_rsb(r);
2633 lock_rsb(r);
2634
2635 receive_flags_reply(lkb, ms);
2636 grant_lock_pc(r, lkb, ms);
2637 queue_cast(r, lkb, 0);
2638
2639 unlock_rsb(r);
2640 put_rsb(r);
2641 dlm_put_lkb(lkb);
2642 }
2643
2644 static void receive_bast(struct dlm_ls *ls, struct dlm_message *ms)
2645 {
2646 struct dlm_lkb *lkb;
2647 struct dlm_rsb *r;
2648 int error;
2649
2650 error = find_lkb(ls, ms->m_remid, &lkb);
2651 if (error) {
2652 log_error(ls, "receive_bast no lkb");
2653 return;
2654 }
2655 DLM_ASSERT(is_process_copy(lkb), dlm_print_lkb(lkb););
2656
2657 r = lkb->lkb_resource;
2658
2659 hold_rsb(r);
2660 lock_rsb(r);
2661
2662 queue_bast(r, lkb, ms->m_bastmode);
2663
2664 unlock_rsb(r);
2665 put_rsb(r);
2666 dlm_put_lkb(lkb);
2667 }
2668
2669 static void receive_lookup(struct dlm_ls *ls, struct dlm_message *ms)
2670 {
2671 int len, error, ret_nodeid, dir_nodeid, from_nodeid, our_nodeid;
2672
2673 from_nodeid = ms->m_header.h_nodeid;
2674 our_nodeid = dlm_our_nodeid();
2675
2676 len = receive_extralen(ms);
2677
2678 dir_nodeid = dlm_hash2nodeid(ls, ms->m_hash);
2679 if (dir_nodeid != our_nodeid) {
2680 log_error(ls, "lookup dir_nodeid %d from %d",
2681 dir_nodeid, from_nodeid);
2682 error = -EINVAL;
2683 ret_nodeid = -1;
2684 goto out;
2685 }
2686
2687 error = dlm_dir_lookup(ls, from_nodeid, ms->m_extra, len, &ret_nodeid);
2688
2689 /* Optimization: we're master so treat lookup as a request */
2690 if (!error && ret_nodeid == our_nodeid) {
2691 receive_request(ls, ms);
2692 return;
2693 }
2694 out:
2695 send_lookup_reply(ls, ms, ret_nodeid, error);
2696 }
2697
2698 static void receive_remove(struct dlm_ls *ls, struct dlm_message *ms)
2699 {
2700 int len, dir_nodeid, from_nodeid;
2701
2702 from_nodeid = ms->m_header.h_nodeid;
2703
2704 len = receive_extralen(ms);
2705
2706 dir_nodeid = dlm_hash2nodeid(ls, ms->m_hash);
2707 if (dir_nodeid != dlm_our_nodeid()) {
2708 log_error(ls, "remove dir entry dir_nodeid %d from %d",
2709 dir_nodeid, from_nodeid);
2710 return;
2711 }
2712
2713 dlm_dir_remove_entry(ls, from_nodeid, ms->m_extra, len);
2714 }
2715
2716 static void receive_request_reply(struct dlm_ls *ls, struct dlm_message *ms)
2717 {
2718 struct dlm_lkb *lkb;
2719 struct dlm_rsb *r;
2720 int error, mstype;
2721
2722 error = find_lkb(ls, ms->m_remid, &lkb);
2723 if (error) {
2724 log_error(ls, "receive_request_reply no lkb");
2725 return;
2726 }
2727 DLM_ASSERT(is_process_copy(lkb), dlm_print_lkb(lkb););
2728
2729 mstype = lkb->lkb_wait_type;
2730 error = remove_from_waiters(lkb);
2731 if (error) {
2732 log_error(ls, "receive_request_reply not on waiters");
2733 goto out;
2734 }
2735
2736 /* this is the value returned from do_request() on the master */
2737 error = ms->m_result;
2738
2739 r = lkb->lkb_resource;
2740 hold_rsb(r);
2741 lock_rsb(r);
2742
2743 /* Optimization: the dir node was also the master, so it took our
2744 lookup as a request and sent request reply instead of lookup reply */
2745 if (mstype == DLM_MSG_LOOKUP) {
2746 r->res_nodeid = ms->m_header.h_nodeid;
2747 lkb->lkb_nodeid = r->res_nodeid;
2748 }
2749
2750 switch (error) {
2751 case -EAGAIN:
2752 /* request would block (be queued) on remote master;
2753 the unhold undoes the original ref from create_lkb()
2754 so it leads to the lkb being freed */
2755 queue_cast(r, lkb, -EAGAIN);
2756 confirm_master(r, -EAGAIN);
2757 unhold_lkb(lkb);
2758 break;
2759
2760 case -EINPROGRESS:
2761 case 0:
2762 /* request was queued or granted on remote master */
2763 receive_flags_reply(lkb, ms);
2764 lkb->lkb_remid = ms->m_lkid;
2765 if (error)
2766 add_lkb(r, lkb, DLM_LKSTS_WAITING);
2767 else {
2768 grant_lock_pc(r, lkb, ms);
2769 queue_cast(r, lkb, 0);
2770 }
2771 confirm_master(r, error);
2772 break;
2773
2774 case -EBADR:
2775 case -ENOTBLK:
2776 /* find_rsb failed to find rsb or rsb wasn't master */
2777 r->res_nodeid = -1;
2778 lkb->lkb_nodeid = -1;
2779 _request_lock(r, lkb);
2780 break;
2781
2782 default:
2783 log_error(ls, "receive_request_reply error %d", error);
2784 }
2785
2786 unlock_rsb(r);
2787 put_rsb(r);
2788 out:
2789 dlm_put_lkb(lkb);
2790 }
2791
2792 static void __receive_convert_reply(struct dlm_rsb *r, struct dlm_lkb *lkb,
2793 struct dlm_message *ms)
2794 {
2795 int error = ms->m_result;
2796
2797 /* this is the value returned from do_convert() on the master */
2798
2799 switch (error) {
2800 case -EAGAIN:
2801 /* convert would block (be queued) on remote master */
2802 queue_cast(r, lkb, -EAGAIN);
2803 break;
2804
2805 case -EINPROGRESS:
2806 /* convert was queued on remote master */
2807 del_lkb(r, lkb);
2808 add_lkb(r, lkb, DLM_LKSTS_CONVERT);
2809 break;
2810
2811 case 0:
2812 /* convert was granted on remote master */
2813 receive_flags_reply(lkb, ms);
2814 grant_lock_pc(r, lkb, ms);
2815 queue_cast(r, lkb, 0);
2816 break;
2817
2818 default:
2819 log_error(r->res_ls, "receive_convert_reply error %d", error);
2820 }
2821 }
2822
2823 static void _receive_convert_reply(struct dlm_lkb *lkb, struct dlm_message *ms)
2824 {
2825 struct dlm_rsb *r = lkb->lkb_resource;
2826
2827 hold_rsb(r);
2828 lock_rsb(r);
2829
2830 __receive_convert_reply(r, lkb, ms);
2831
2832 unlock_rsb(r);
2833 put_rsb(r);
2834 }
2835
2836 static void receive_convert_reply(struct dlm_ls *ls, struct dlm_message *ms)
2837 {
2838 struct dlm_lkb *lkb;
2839 int error;
2840
2841 error = find_lkb(ls, ms->m_remid, &lkb);
2842 if (error) {
2843 log_error(ls, "receive_convert_reply no lkb");
2844 return;
2845 }
2846 DLM_ASSERT(is_process_copy(lkb), dlm_print_lkb(lkb););
2847
2848 error = remove_from_waiters(lkb);
2849 if (error) {
2850 log_error(ls, "receive_convert_reply not on waiters");
2851 goto out;
2852 }
2853
2854 _receive_convert_reply(lkb, ms);
2855 out:
2856 dlm_put_lkb(lkb);
2857 }
2858
2859 static void _receive_unlock_reply(struct dlm_lkb *lkb, struct dlm_message *ms)
2860 {
2861 struct dlm_rsb *r = lkb->lkb_resource;
2862 int error = ms->m_result;
2863
2864 hold_rsb(r);
2865 lock_rsb(r);
2866
2867 /* this is the value returned from do_unlock() on the master */
2868
2869 switch (error) {
2870 case -DLM_EUNLOCK:
2871 receive_flags_reply(lkb, ms);
2872 remove_lock_pc(r, lkb);
2873 queue_cast(r, lkb, -DLM_EUNLOCK);
2874 break;
2875 default:
2876 log_error(r->res_ls, "receive_unlock_reply error %d", error);
2877 }
2878
2879 unlock_rsb(r);
2880 put_rsb(r);
2881 }
2882
2883 static void receive_unlock_reply(struct dlm_ls *ls, struct dlm_message *ms)
2884 {
2885 struct dlm_lkb *lkb;
2886 int error;
2887
2888 error = find_lkb(ls, ms->m_remid, &lkb);
2889 if (error) {
2890 log_error(ls, "receive_unlock_reply no lkb");
2891 return;
2892 }
2893 DLM_ASSERT(is_process_copy(lkb), dlm_print_lkb(lkb););
2894
2895 error = remove_from_waiters(lkb);
2896 if (error) {
2897 log_error(ls, "receive_unlock_reply not on waiters");
2898 goto out;
2899 }
2900
2901 _receive_unlock_reply(lkb, ms);
2902 out:
2903 dlm_put_lkb(lkb);
2904 }
2905
2906 static void _receive_cancel_reply(struct dlm_lkb *lkb, struct dlm_message *ms)
2907 {
2908 struct dlm_rsb *r = lkb->lkb_resource;
2909 int error = ms->m_result;
2910
2911 hold_rsb(r);
2912 lock_rsb(r);
2913
2914 /* this is the value returned from do_cancel() on the master */
2915
2916 switch (error) {
2917 case -DLM_ECANCEL:
2918 receive_flags_reply(lkb, ms);
2919 revert_lock_pc(r, lkb);
2920 queue_cast(r, lkb, -DLM_ECANCEL);
2921 break;
2922 default:
2923 log_error(r->res_ls, "receive_cancel_reply error %d", error);
2924 }
2925
2926 unlock_rsb(r);
2927 put_rsb(r);
2928 }
2929
2930 static void receive_cancel_reply(struct dlm_ls *ls, struct dlm_message *ms)
2931 {
2932 struct dlm_lkb *lkb;
2933 int error;
2934
2935 error = find_lkb(ls, ms->m_remid, &lkb);
2936 if (error) {
2937 log_error(ls, "receive_cancel_reply no lkb");
2938 return;
2939 }
2940 DLM_ASSERT(is_process_copy(lkb), dlm_print_lkb(lkb););
2941
2942 error = remove_from_waiters(lkb);
2943 if (error) {
2944 log_error(ls, "receive_cancel_reply not on waiters");
2945 goto out;
2946 }
2947
2948 _receive_cancel_reply(lkb, ms);
2949 out:
2950 dlm_put_lkb(lkb);
2951 }
2952
2953 static void receive_lookup_reply(struct dlm_ls *ls, struct dlm_message *ms)
2954 {
2955 struct dlm_lkb *lkb;
2956 struct dlm_rsb *r;
2957 int error, ret_nodeid;
2958
2959 error = find_lkb(ls, ms->m_lkid, &lkb);
2960 if (error) {
2961 log_error(ls, "receive_lookup_reply no lkb");
2962 return;
2963 }
2964
2965 error = remove_from_waiters(lkb);
2966 if (error) {
2967 log_error(ls, "receive_lookup_reply not on waiters");
2968 goto out;
2969 }
2970
2971 /* this is the value returned by dlm_dir_lookup on dir node
2972 FIXME: will a non-zero error ever be returned? */
2973 error = ms->m_result;
2974
2975 r = lkb->lkb_resource;
2976 hold_rsb(r);
2977 lock_rsb(r);
2978
2979 ret_nodeid = ms->m_nodeid;
2980 if (ret_nodeid == dlm_our_nodeid()) {
2981 r->res_nodeid = 0;
2982 ret_nodeid = 0;
2983 r->res_first_lkid = 0;
2984 } else {
2985 /* set_master() will copy res_nodeid to lkb_nodeid */
2986 r->res_nodeid = ret_nodeid;
2987 }
2988
2989 _request_lock(r, lkb);
2990
2991 if (!ret_nodeid)
2992 process_lookup_list(r);
2993
2994 unlock_rsb(r);
2995 put_rsb(r);
2996 out:
2997 dlm_put_lkb(lkb);
2998 }
2999
3000 int dlm_receive_message(struct dlm_header *hd, int nodeid, int recovery)
3001 {
3002 struct dlm_message *ms = (struct dlm_message *) hd;
3003 struct dlm_ls *ls;
3004 int error;
3005
3006 if (!recovery)
3007 dlm_message_in(ms);
3008
3009 ls = dlm_find_lockspace_global(hd->h_lockspace);
3010 if (!ls) {
3011 log_print("drop message %d from %d for unknown lockspace %d",
3012 ms->m_type, nodeid, hd->h_lockspace);
3013 return -EINVAL;
3014 }
3015
3016 /* recovery may have just ended leaving a bunch of backed-up requests
3017 in the requestqueue; wait while dlm_recoverd clears them */
3018
3019 if (!recovery)
3020 dlm_wait_requestqueue(ls);
3021
3022 /* recovery may have just started while there were a bunch of
3023 in-flight requests -- save them in requestqueue to be processed
3024 after recovery. we can't let dlm_recvd block on the recovery
3025 lock. if dlm_recoverd is calling this function to clear the
3026 requestqueue, it needs to be interrupted (-EINTR) if another
3027 recovery operation is starting. */
3028
3029 while (1) {
3030 if (dlm_locking_stopped(ls)) {
3031 if (!recovery)
3032 dlm_add_requestqueue(ls, nodeid, hd);
3033 error = -EINTR;
3034 goto out;
3035 }
3036
3037 if (lock_recovery_try(ls))
3038 break;
3039 schedule();
3040 }
3041
3042 switch (ms->m_type) {
3043
3044 /* messages sent to a master node */
3045
3046 case DLM_MSG_REQUEST:
3047 receive_request(ls, ms);
3048 break;
3049
3050 case DLM_MSG_CONVERT:
3051 receive_convert(ls, ms);
3052 break;
3053
3054 case DLM_MSG_UNLOCK:
3055 receive_unlock(ls, ms);
3056 break;
3057
3058 case DLM_MSG_CANCEL:
3059 receive_cancel(ls, ms);
3060 break;
3061
3062 /* messages sent from a master node (replies to above) */
3063
3064 case DLM_MSG_REQUEST_REPLY:
3065 receive_request_reply(ls, ms);
3066 break;
3067
3068 case DLM_MSG_CONVERT_REPLY:
3069 receive_convert_reply(ls, ms);
3070 break;
3071
3072 case DLM_MSG_UNLOCK_REPLY:
3073 receive_unlock_reply(ls, ms);
3074 break;
3075
3076 case DLM_MSG_CANCEL_REPLY:
3077 receive_cancel_reply(ls, ms);
3078 break;
3079
3080 /* messages sent from a master node (only two types of async msg) */
3081
3082 case DLM_MSG_GRANT:
3083 receive_grant(ls, ms);
3084 break;
3085
3086 case DLM_MSG_BAST:
3087 receive_bast(ls, ms);
3088 break;
3089
3090 /* messages sent to a dir node */
3091
3092 case DLM_MSG_LOOKUP:
3093 receive_lookup(ls, ms);
3094 break;
3095
3096 case DLM_MSG_REMOVE:
3097 receive_remove(ls, ms);
3098 break;
3099
3100 /* messages sent from a dir node (remove has no reply) */
3101
3102 case DLM_MSG_LOOKUP_REPLY:
3103 receive_lookup_reply(ls, ms);
3104 break;
3105
3106 default:
3107 log_error(ls, "unknown message type %d", ms->m_type);
3108 }
3109
3110 unlock_recovery(ls);
3111 out:
3112 dlm_put_lockspace(ls);
3113 dlm_astd_wake();
3114 return 0;
3115 }
3116
3117
3118 /*
3119 * Recovery related
3120 */
3121
3122 static void recover_convert_waiter(struct dlm_ls *ls, struct dlm_lkb *lkb)
3123 {
3124 if (middle_conversion(lkb)) {
3125 hold_lkb(lkb);
3126 ls->ls_stub_ms.m_result = -EINPROGRESS;
3127 _remove_from_waiters(lkb);
3128 _receive_convert_reply(lkb, &ls->ls_stub_ms);
3129
3130 /* Same special case as in receive_rcom_lock_args() */
3131 lkb->lkb_grmode = DLM_LOCK_IV;
3132 rsb_set_flag(lkb->lkb_resource, RSB_RECOVER_CONVERT);
3133 unhold_lkb(lkb);
3134
3135 } else if (lkb->lkb_rqmode >= lkb->lkb_grmode) {
3136 lkb->lkb_flags |= DLM_IFL_RESEND;
3137 }
3138
3139 /* lkb->lkb_rqmode < lkb->lkb_grmode shouldn't happen since down
3140 conversions are async; there's no reply from the remote master */
3141 }
3142
3143 /* A waiting lkb needs recovery if the master node has failed, or
3144 the master node is changing (only when no directory is used) */
3145
3146 static int waiter_needs_recovery(struct dlm_ls *ls, struct dlm_lkb *lkb)
3147 {
3148 if (dlm_is_removed(ls, lkb->lkb_nodeid))
3149 return 1;
3150
3151 if (!dlm_no_directory(ls))
3152 return 0;
3153
3154 if (dlm_dir_nodeid(lkb->lkb_resource) != lkb->lkb_nodeid)
3155 return 1;
3156
3157 return 0;
3158 }
3159
3160 /* Recovery for locks that are waiting for replies from nodes that are now
3161 gone. We can just complete unlocks and cancels by faking a reply from the
3162 dead node. Requests and up-conversions we flag to be resent after
3163 recovery. Down-conversions can just be completed with a fake reply like
3164 unlocks. Conversions between PR and CW need special attention. */
3165
3166 void dlm_recover_waiters_pre(struct dlm_ls *ls)
3167 {
3168 struct dlm_lkb *lkb, *safe;
3169
3170 mutex_lock(&ls->ls_waiters_mutex);
3171
3172 list_for_each_entry_safe(lkb, safe, &ls->ls_waiters, lkb_wait_reply) {
3173 log_debug(ls, "pre recover waiter lkid %x type %d flags %x",
3174 lkb->lkb_id, lkb->lkb_wait_type, lkb->lkb_flags);
3175
3176 /* all outstanding lookups, regardless of destination will be
3177 resent after recovery is done */
3178
3179 if (lkb->lkb_wait_type == DLM_MSG_LOOKUP) {
3180 lkb->lkb_flags |= DLM_IFL_RESEND;
3181 continue;
3182 }
3183
3184 if (!waiter_needs_recovery(ls, lkb))
3185 continue;
3186
3187 switch (lkb->lkb_wait_type) {
3188
3189 case DLM_MSG_REQUEST:
3190 lkb->lkb_flags |= DLM_IFL_RESEND;
3191 break;
3192
3193 case DLM_MSG_CONVERT:
3194 recover_convert_waiter(ls, lkb);
3195 break;
3196
3197 case DLM_MSG_UNLOCK:
3198 hold_lkb(lkb);
3199 ls->ls_stub_ms.m_result = -DLM_EUNLOCK;
3200 _remove_from_waiters(lkb);
3201 _receive_unlock_reply(lkb, &ls->ls_stub_ms);
3202 dlm_put_lkb(lkb);
3203 break;
3204
3205 case DLM_MSG_CANCEL:
3206 hold_lkb(lkb);
3207 ls->ls_stub_ms.m_result = -DLM_ECANCEL;
3208 _remove_from_waiters(lkb);
3209 _receive_cancel_reply(lkb, &ls->ls_stub_ms);
3210 dlm_put_lkb(lkb);
3211 break;
3212
3213 default:
3214 log_error(ls, "invalid lkb wait_type %d",
3215 lkb->lkb_wait_type);
3216 }
3217 schedule();
3218 }
3219 mutex_unlock(&ls->ls_waiters_mutex);
3220 }
3221
3222 static int remove_resend_waiter(struct dlm_ls *ls, struct dlm_lkb **lkb_ret)
3223 {
3224 struct dlm_lkb *lkb;
3225 int rv = 0;
3226
3227 mutex_lock(&ls->ls_waiters_mutex);
3228 list_for_each_entry(lkb, &ls->ls_waiters, lkb_wait_reply) {
3229 if (lkb->lkb_flags & DLM_IFL_RESEND) {
3230 rv = lkb->lkb_wait_type;
3231 _remove_from_waiters(lkb);
3232 lkb->lkb_flags &= ~DLM_IFL_RESEND;
3233 break;
3234 }
3235 }
3236 mutex_unlock(&ls->ls_waiters_mutex);
3237
3238 if (!rv)
3239 lkb = NULL;
3240 *lkb_ret = lkb;
3241 return rv;
3242 }
3243
3244 /* Deal with lookups and lkb's marked RESEND from _pre. We may now be the
3245 master or dir-node for r. Processing the lkb may result in it being placed
3246 back on waiters. */
3247
3248 int dlm_recover_waiters_post(struct dlm_ls *ls)
3249 {
3250 struct dlm_lkb *lkb;
3251 struct dlm_rsb *r;
3252 int error = 0, mstype;
3253
3254 while (1) {
3255 if (dlm_locking_stopped(ls)) {
3256 log_debug(ls, "recover_waiters_post aborted");
3257 error = -EINTR;
3258 break;
3259 }
3260
3261 mstype = remove_resend_waiter(ls, &lkb);
3262 if (!mstype)
3263 break;
3264
3265 r = lkb->lkb_resource;
3266
3267 log_debug(ls, "recover_waiters_post %x type %d flags %x %s",
3268 lkb->lkb_id, mstype, lkb->lkb_flags, r->res_name);
3269
3270 switch (mstype) {
3271
3272 case DLM_MSG_LOOKUP:
3273 hold_rsb(r);
3274 lock_rsb(r);
3275 _request_lock(r, lkb);
3276 if (is_master(r))
3277 confirm_master(r, 0);
3278 unlock_rsb(r);
3279 put_rsb(r);
3280 break;
3281
3282 case DLM_MSG_REQUEST:
3283 hold_rsb(r);
3284 lock_rsb(r);
3285 _request_lock(r, lkb);
3286 if (is_master(r))
3287 confirm_master(r, 0);
3288 unlock_rsb(r);
3289 put_rsb(r);
3290 break;
3291
3292 case DLM_MSG_CONVERT:
3293 hold_rsb(r);
3294 lock_rsb(r);
3295 _convert_lock(r, lkb);
3296 unlock_rsb(r);
3297 put_rsb(r);
3298 break;
3299
3300 default:
3301 log_error(ls, "recover_waiters_post type %d", mstype);
3302 }
3303 }
3304
3305 return error;
3306 }
3307
3308 static void purge_queue(struct dlm_rsb *r, struct list_head *queue,
3309 int (*test)(struct dlm_ls *ls, struct dlm_lkb *lkb))
3310 {
3311 struct dlm_ls *ls = r->res_ls;
3312 struct dlm_lkb *lkb, *safe;
3313
3314 list_for_each_entry_safe(lkb, safe, queue, lkb_statequeue) {
3315 if (test(ls, lkb)) {
3316 rsb_set_flag(r, RSB_LOCKS_PURGED);
3317 del_lkb(r, lkb);
3318 /* this put should free the lkb */
3319 if (!dlm_put_lkb(lkb))
3320 log_error(ls, "purged lkb not released");
3321 }
3322 }
3323 }
3324
3325 static int purge_dead_test(struct dlm_ls *ls, struct dlm_lkb *lkb)
3326 {
3327 return (is_master_copy(lkb) && dlm_is_removed(ls, lkb->lkb_nodeid));
3328 }
3329
3330 static int purge_mstcpy_test(struct dlm_ls *ls, struct dlm_lkb *lkb)
3331 {
3332 return is_master_copy(lkb);
3333 }
3334
3335 static void purge_dead_locks(struct dlm_rsb *r)
3336 {
3337 purge_queue(r, &r->res_grantqueue, &purge_dead_test);
3338 purge_queue(r, &r->res_convertqueue, &purge_dead_test);
3339 purge_queue(r, &r->res_waitqueue, &purge_dead_test);
3340 }
3341
3342 void dlm_purge_mstcpy_locks(struct dlm_rsb *r)
3343 {
3344 purge_queue(r, &r->res_grantqueue, &purge_mstcpy_test);
3345 purge_queue(r, &r->res_convertqueue, &purge_mstcpy_test);
3346 purge_queue(r, &r->res_waitqueue, &purge_mstcpy_test);
3347 }
3348
3349 /* Get rid of locks held by nodes that are gone. */
3350
3351 int dlm_purge_locks(struct dlm_ls *ls)
3352 {
3353 struct dlm_rsb *r;
3354
3355 log_debug(ls, "dlm_purge_locks");
3356
3357 down_write(&ls->ls_root_sem);
3358 list_for_each_entry(r, &ls->ls_root_list, res_root_list) {
3359 hold_rsb(r);
3360 lock_rsb(r);
3361 if (is_master(r))
3362 purge_dead_locks(r);
3363 unlock_rsb(r);
3364 unhold_rsb(r);
3365
3366 schedule();
3367 }
3368 up_write(&ls->ls_root_sem);
3369
3370 return 0;
3371 }
3372
3373 static struct dlm_rsb *find_purged_rsb(struct dlm_ls *ls, int bucket)
3374 {
3375 struct dlm_rsb *r, *r_ret = NULL;
3376
3377 read_lock(&ls->ls_rsbtbl[bucket].lock);
3378 list_for_each_entry(r, &ls->ls_rsbtbl[bucket].list, res_hashchain) {
3379 if (!rsb_flag(r, RSB_LOCKS_PURGED))
3380 continue;
3381 hold_rsb(r);
3382 rsb_clear_flag(r, RSB_LOCKS_PURGED);
3383 r_ret = r;
3384 break;
3385 }
3386 read_unlock(&ls->ls_rsbtbl[bucket].lock);
3387 return r_ret;
3388 }
3389
3390 void dlm_grant_after_purge(struct dlm_ls *ls)
3391 {
3392 struct dlm_rsb *r;
3393 int bucket = 0;
3394
3395 while (1) {
3396 r = find_purged_rsb(ls, bucket);
3397 if (!r) {
3398 if (bucket == ls->ls_rsbtbl_size - 1)
3399 break;
3400 bucket++;
3401 continue;
3402 }
3403 lock_rsb(r);
3404 if (is_master(r)) {
3405 grant_pending_locks(r);
3406 confirm_master(r, 0);
3407 }
3408 unlock_rsb(r);
3409 put_rsb(r);
3410 schedule();
3411 }
3412 }
3413
3414 static struct dlm_lkb *search_remid_list(struct list_head *head, int nodeid,
3415 uint32_t remid)
3416 {
3417 struct dlm_lkb *lkb;
3418
3419 list_for_each_entry(lkb, head, lkb_statequeue) {
3420 if (lkb->lkb_nodeid == nodeid && lkb->lkb_remid == remid)
3421 return lkb;
3422 }
3423 return NULL;
3424 }
3425
3426 static struct dlm_lkb *search_remid(struct dlm_rsb *r, int nodeid,
3427 uint32_t remid)
3428 {
3429 struct dlm_lkb *lkb;
3430
3431 lkb = search_remid_list(&r->res_grantqueue, nodeid, remid);
3432 if (lkb)
3433 return lkb;
3434 lkb = search_remid_list(&r->res_convertqueue, nodeid, remid);
3435 if (lkb)
3436 return lkb;
3437 lkb = search_remid_list(&r->res_waitqueue, nodeid, remid);
3438 if (lkb)
3439 return lkb;
3440 return NULL;
3441 }
3442
3443 static int receive_rcom_lock_args(struct dlm_ls *ls, struct dlm_lkb *lkb,
3444 struct dlm_rsb *r, struct dlm_rcom *rc)
3445 {
3446 struct rcom_lock *rl = (struct rcom_lock *) rc->rc_buf;
3447 int lvblen;
3448
3449 lkb->lkb_nodeid = rc->rc_header.h_nodeid;
3450 lkb->lkb_ownpid = rl->rl_ownpid;
3451 lkb->lkb_remid = rl->rl_lkid;
3452 lkb->lkb_exflags = rl->rl_exflags;
3453 lkb->lkb_flags = rl->rl_flags & 0x0000FFFF;
3454 lkb->lkb_flags |= DLM_IFL_MSTCPY;
3455 lkb->lkb_lvbseq = rl->rl_lvbseq;
3456 lkb->lkb_rqmode = rl->rl_rqmode;
3457 lkb->lkb_grmode = rl->rl_grmode;
3458 /* don't set lkb_status because add_lkb wants to itself */
3459
3460 lkb->lkb_bastaddr = (void *) (long) (rl->rl_asts & AST_BAST);
3461 lkb->lkb_astaddr = (void *) (long) (rl->rl_asts & AST_COMP);
3462
3463 if (lkb->lkb_exflags & DLM_LKF_VALBLK) {
3464 lkb->lkb_lvbptr = allocate_lvb(ls);
3465 if (!lkb->lkb_lvbptr)
3466 return -ENOMEM;
3467 lvblen = rc->rc_header.h_length - sizeof(struct dlm_rcom) -
3468 sizeof(struct rcom_lock);
3469 memcpy(lkb->lkb_lvbptr, rl->rl_lvb, lvblen);
3470 }
3471
3472 /* Conversions between PR and CW (middle modes) need special handling.
3473 The real granted mode of these converting locks cannot be determined
3474 until all locks have been rebuilt on the rsb (recover_conversion) */
3475
3476 if (rl->rl_wait_type == DLM_MSG_CONVERT && middle_conversion(lkb)) {
3477 rl->rl_status = DLM_LKSTS_CONVERT;
3478 lkb->lkb_grmode = DLM_LOCK_IV;
3479 rsb_set_flag(r, RSB_RECOVER_CONVERT);
3480 }
3481
3482 return 0;
3483 }
3484
3485 /* This lkb may have been recovered in a previous aborted recovery so we need
3486 to check if the rsb already has an lkb with the given remote nodeid/lkid.
3487 If so we just send back a standard reply. If not, we create a new lkb with
3488 the given values and send back our lkid. We send back our lkid by sending
3489 back the rcom_lock struct we got but with the remid field filled in. */
3490
3491 int dlm_recover_master_copy(struct dlm_ls *ls, struct dlm_rcom *rc)
3492 {
3493 struct rcom_lock *rl = (struct rcom_lock *) rc->rc_buf;
3494 struct dlm_rsb *r;
3495 struct dlm_lkb *lkb;
3496 int error;
3497
3498 if (rl->rl_parent_lkid) {
3499 error = -EOPNOTSUPP;
3500 goto out;
3501 }
3502
3503 error = find_rsb(ls, rl->rl_name, rl->rl_namelen, R_MASTER, &r);
3504 if (error)
3505 goto out;
3506
3507 lock_rsb(r);
3508
3509 lkb = search_remid(r, rc->rc_header.h_nodeid, rl->rl_lkid);
3510 if (lkb) {
3511 error = -EEXIST;
3512 goto out_remid;
3513 }
3514
3515 error = create_lkb(ls, &lkb);
3516 if (error)
3517 goto out_unlock;
3518
3519 error = receive_rcom_lock_args(ls, lkb, r, rc);
3520 if (error) {
3521 __put_lkb(ls, lkb);
3522 goto out_unlock;
3523 }
3524
3525 attach_lkb(r, lkb);
3526 add_lkb(r, lkb, rl->rl_status);
3527 error = 0;
3528
3529 out_remid:
3530 /* this is the new value returned to the lock holder for
3531 saving in its process-copy lkb */
3532 rl->rl_remid = lkb->lkb_id;
3533
3534 out_unlock:
3535 unlock_rsb(r);
3536 put_rsb(r);
3537 out:
3538 if (error)
3539 log_print("recover_master_copy %d %x", error, rl->rl_lkid);
3540 rl->rl_result = error;
3541 return error;
3542 }
3543
3544 int dlm_recover_process_copy(struct dlm_ls *ls, struct dlm_rcom *rc)
3545 {
3546 struct rcom_lock *rl = (struct rcom_lock *) rc->rc_buf;
3547 struct dlm_rsb *r;
3548 struct dlm_lkb *lkb;
3549 int error;
3550
3551 error = find_lkb(ls, rl->rl_lkid, &lkb);
3552 if (error) {
3553 log_error(ls, "recover_process_copy no lkid %x", rl->rl_lkid);
3554 return error;
3555 }
3556
3557 DLM_ASSERT(is_process_copy(lkb), dlm_print_lkb(lkb););
3558
3559 error = rl->rl_result;
3560
3561 r = lkb->lkb_resource;
3562 hold_rsb(r);
3563 lock_rsb(r);
3564
3565 switch (error) {
3566 case -EEXIST:
3567 log_debug(ls, "master copy exists %x", lkb->lkb_id);
3568 /* fall through */
3569 case 0:
3570 lkb->lkb_remid = rl->rl_remid;
3571 break;
3572 default:
3573 log_error(ls, "dlm_recover_process_copy unknown error %d %x",
3574 error, lkb->lkb_id);
3575 }
3576
3577 /* an ack for dlm_recover_locks() which waits for replies from
3578 all the locks it sends to new masters */
3579 dlm_recovered_lock(r);
3580
3581 unlock_rsb(r);
3582 put_rsb(r);
3583 dlm_put_lkb(lkb);
3584
3585 return 0;
3586 }
3587
3588 int dlm_user_request(struct dlm_ls *ls, struct dlm_user_args *ua,
3589 int mode, uint32_t flags, void *name, unsigned int namelen,
3590 uint32_t parent_lkid)
3591 {
3592 struct dlm_lkb *lkb;
3593 struct dlm_args args;
3594 int error;
3595
3596 lock_recovery(ls);
3597
3598 error = create_lkb(ls, &lkb);
3599 if (error) {
3600 kfree(ua);
3601 goto out;
3602 }
3603
3604 if (flags & DLM_LKF_VALBLK) {
3605 ua->lksb.sb_lvbptr = kmalloc(DLM_USER_LVB_LEN, GFP_KERNEL);
3606 if (!ua->lksb.sb_lvbptr) {
3607 kfree(ua);
3608 __put_lkb(ls, lkb);
3609 error = -ENOMEM;
3610 goto out;
3611 }
3612 }
3613
3614 /* After ua is attached to lkb it will be freed by free_lkb().
3615 When DLM_IFL_USER is set, the dlm knows that this is a userspace
3616 lock and that lkb_astparam is the dlm_user_args structure. */
3617
3618 error = set_lock_args(mode, &ua->lksb, flags, namelen, parent_lkid,
3619 DLM_FAKE_USER_AST, ua, DLM_FAKE_USER_AST, &args);
3620 lkb->lkb_flags |= DLM_IFL_USER;
3621 ua->old_mode = DLM_LOCK_IV;
3622
3623 if (error) {
3624 __put_lkb(ls, lkb);
3625 goto out;
3626 }
3627
3628 error = request_lock(ls, lkb, name, namelen, &args);
3629
3630 switch (error) {
3631 case 0:
3632 break;
3633 case -EINPROGRESS:
3634 error = 0;
3635 break;
3636 case -EAGAIN:
3637 error = 0;
3638 /* fall through */
3639 default:
3640 __put_lkb(ls, lkb);
3641 goto out;
3642 }
3643
3644 /* add this new lkb to the per-process list of locks */
3645 spin_lock(&ua->proc->locks_spin);
3646 kref_get(&lkb->lkb_ref);
3647 list_add_tail(&lkb->lkb_ownqueue, &ua->proc->locks);
3648 spin_unlock(&ua->proc->locks_spin);
3649 out:
3650 unlock_recovery(ls);
3651 return error;
3652 }
3653
3654 int dlm_user_convert(struct dlm_ls *ls, struct dlm_user_args *ua_tmp,
3655 int mode, uint32_t flags, uint32_t lkid, char *lvb_in)
3656 {
3657 struct dlm_lkb *lkb;
3658 struct dlm_args args;
3659 struct dlm_user_args *ua;
3660 int error;
3661
3662 lock_recovery(ls);
3663
3664 error = find_lkb(ls, lkid, &lkb);
3665 if (error)
3666 goto out;
3667
3668 /* user can change the params on its lock when it converts it, or
3669 add an lvb that didn't exist before */
3670
3671 ua = (struct dlm_user_args *)lkb->lkb_astparam;
3672
3673 if (flags & DLM_LKF_VALBLK && !ua->lksb.sb_lvbptr) {
3674 ua->lksb.sb_lvbptr = kmalloc(DLM_USER_LVB_LEN, GFP_KERNEL);
3675 if (!ua->lksb.sb_lvbptr) {
3676 error = -ENOMEM;
3677 goto out_put;
3678 }
3679 }
3680 if (lvb_in && ua->lksb.sb_lvbptr)
3681 memcpy(ua->lksb.sb_lvbptr, lvb_in, DLM_USER_LVB_LEN);
3682
3683 ua->castparam = ua_tmp->castparam;
3684 ua->castaddr = ua_tmp->castaddr;
3685 ua->bastparam = ua_tmp->bastparam;
3686 ua->bastaddr = ua_tmp->bastaddr;
3687 ua->user_lksb = ua_tmp->user_lksb;
3688 ua->old_mode = lkb->lkb_grmode;
3689
3690 error = set_lock_args(mode, &ua->lksb, flags, 0, 0, DLM_FAKE_USER_AST,
3691 ua, DLM_FAKE_USER_AST, &args);
3692 if (error)
3693 goto out_put;
3694
3695 error = convert_lock(ls, lkb, &args);
3696
3697 if (error == -EINPROGRESS || error == -EAGAIN)
3698 error = 0;
3699 out_put:
3700 dlm_put_lkb(lkb);
3701 out:
3702 unlock_recovery(ls);
3703 kfree(ua_tmp);
3704 return error;
3705 }
3706
3707 int dlm_user_unlock(struct dlm_ls *ls, struct dlm_user_args *ua_tmp,
3708 uint32_t flags, uint32_t lkid, char *lvb_in)
3709 {
3710 struct dlm_lkb *lkb;
3711 struct dlm_args args;
3712 struct dlm_user_args *ua;
3713 int error;
3714
3715 lock_recovery(ls);
3716
3717 error = find_lkb(ls, lkid, &lkb);
3718 if (error)
3719 goto out;
3720
3721 ua = (struct dlm_user_args *)lkb->lkb_astparam;
3722
3723 if (lvb_in && ua->lksb.sb_lvbptr)
3724 memcpy(ua->lksb.sb_lvbptr, lvb_in, DLM_USER_LVB_LEN);
3725 ua->castparam = ua_tmp->castparam;
3726 ua->user_lksb = ua_tmp->user_lksb;
3727
3728 error = set_unlock_args(flags, ua, &args);
3729 if (error)
3730 goto out_put;
3731
3732 error = unlock_lock(ls, lkb, &args);
3733
3734 if (error == -DLM_EUNLOCK)
3735 error = 0;
3736 if (error)
3737 goto out_put;
3738
3739 spin_lock(&ua->proc->locks_spin);
3740 list_del_init(&lkb->lkb_ownqueue);
3741 spin_unlock(&ua->proc->locks_spin);
3742
3743 /* this removes the reference for the proc->locks list added by
3744 dlm_user_request */
3745 unhold_lkb(lkb);
3746 out_put:
3747 dlm_put_lkb(lkb);
3748 out:
3749 unlock_recovery(ls);
3750 return error;
3751 }
3752
3753 int dlm_user_cancel(struct dlm_ls *ls, struct dlm_user_args *ua_tmp,
3754 uint32_t flags, uint32_t lkid)
3755 {
3756 struct dlm_lkb *lkb;
3757 struct dlm_args args;
3758 struct dlm_user_args *ua;
3759 int error;
3760
3761 lock_recovery(ls);
3762
3763 error = find_lkb(ls, lkid, &lkb);
3764 if (error)
3765 goto out;
3766
3767 ua = (struct dlm_user_args *)lkb->lkb_astparam;
3768 ua->castparam = ua_tmp->castparam;
3769 ua->user_lksb = ua_tmp->user_lksb;
3770
3771 error = set_unlock_args(flags, ua, &args);
3772 if (error)
3773 goto out_put;
3774
3775 error = cancel_lock(ls, lkb, &args);
3776
3777 if (error == -DLM_ECANCEL)
3778 error = 0;
3779 if (error)
3780 goto out_put;
3781
3782 /* this lkb was removed from the WAITING queue */
3783 if (lkb->lkb_grmode == DLM_LOCK_IV) {
3784 spin_lock(&ua->proc->locks_spin);
3785 list_del_init(&lkb->lkb_ownqueue);
3786 spin_unlock(&ua->proc->locks_spin);
3787 unhold_lkb(lkb);
3788 }
3789 out_put:
3790 dlm_put_lkb(lkb);
3791 out:
3792 unlock_recovery(ls);
3793 return error;
3794 }
3795
3796 static int orphan_proc_lock(struct dlm_ls *ls, struct dlm_lkb *lkb)
3797 {
3798 struct dlm_user_args *ua = (struct dlm_user_args *)lkb->lkb_astparam;
3799
3800 if (ua->lksb.sb_lvbptr)
3801 kfree(ua->lksb.sb_lvbptr);
3802 kfree(ua);
3803 lkb->lkb_astparam = (long)NULL;
3804
3805 /* TODO: propogate to master if needed */
3806 return 0;
3807 }
3808
3809 /* The force flag allows the unlock to go ahead even if the lkb isn't granted.
3810 Regardless of what rsb queue the lock is on, it's removed and freed. */
3811
3812 static int unlock_proc_lock(struct dlm_ls *ls, struct dlm_lkb *lkb)
3813 {
3814 struct dlm_user_args *ua = (struct dlm_user_args *)lkb->lkb_astparam;
3815 struct dlm_args args;
3816 int error;
3817
3818 /* FIXME: we need to handle the case where the lkb is in limbo
3819 while the rsb is being looked up, currently we assert in
3820 _unlock_lock/is_remote because rsb nodeid is -1. */
3821
3822 set_unlock_args(DLM_LKF_FORCEUNLOCK, ua, &args);
3823
3824 error = unlock_lock(ls, lkb, &args);
3825 if (error == -DLM_EUNLOCK)
3826 error = 0;
3827 return error;
3828 }
3829
3830 /* The ls_clear_proc_locks mutex protects against dlm_user_add_asts() which
3831 1) references lkb->ua which we free here and 2) adds lkbs to proc->asts,
3832 which we clear here. */
3833
3834 /* proc CLOSING flag is set so no more device_reads should look at proc->asts
3835 list, and no more device_writes should add lkb's to proc->locks list; so we
3836 shouldn't need to take asts_spin or locks_spin here. this assumes that
3837 device reads/writes/closes are serialized -- FIXME: we may need to serialize
3838 them ourself. */
3839
3840 void dlm_clear_proc_locks(struct dlm_ls *ls, struct dlm_user_proc *proc)
3841 {
3842 struct dlm_lkb *lkb, *safe;
3843
3844 lock_recovery(ls);
3845 mutex_lock(&ls->ls_clear_proc_locks);
3846
3847 list_for_each_entry_safe(lkb, safe, &proc->locks, lkb_ownqueue) {
3848 if (lkb->lkb_ast_type) {
3849 list_del(&lkb->lkb_astqueue);
3850 unhold_lkb(lkb);
3851 }
3852
3853 list_del_init(&lkb->lkb_ownqueue);
3854
3855 if (lkb->lkb_exflags & DLM_LKF_PERSISTENT) {
3856 lkb->lkb_flags |= DLM_IFL_ORPHAN;
3857 orphan_proc_lock(ls, lkb);
3858 } else {
3859 lkb->lkb_flags |= DLM_IFL_DEAD;
3860 unlock_proc_lock(ls, lkb);
3861 }
3862
3863 /* this removes the reference for the proc->locks list
3864 added by dlm_user_request, it may result in the lkb
3865 being freed */
3866
3867 dlm_put_lkb(lkb);
3868 }
3869 mutex_unlock(&ls->ls_clear_proc_locks);
3870 unlock_recovery(ls);
3871 }
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