1 /******************************************************************************
2 *******************************************************************************
3 **
4 ** Copyright (C) 2005-2008 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 int _cancel_lock(struct dlm_rsb *r, struct dlm_lkb *lkb);
86 static void __receive_convert_reply(struct dlm_rsb *r, struct dlm_lkb *lkb,
87 struct dlm_message *ms);
88 static int receive_extralen(struct dlm_message *ms);
89 static void do_purge(struct dlm_ls *ls, int nodeid, int pid);
90 static void del_timeout(struct dlm_lkb *lkb);
91
92 /*
93 * Lock compatibilty matrix - thanks Steve
94 * UN = Unlocked state. Not really a state, used as a flag
95 * PD = Padding. Used to make the matrix a nice power of two in size
96 * Other states are the same as the VMS DLM.
97 * Usage: matrix[grmode+1][rqmode+1] (although m[rq+1][gr+1] is the same)
98 */
99
100 static const int __dlm_compat_matrix[8][8] = {
101 /* UN NL CR CW PR PW EX PD */
102 {1, 1, 1, 1, 1, 1, 1, 0}, /* UN */
103 {1, 1, 1, 1, 1, 1, 1, 0}, /* NL */
104 {1, 1, 1, 1, 1, 1, 0, 0}, /* CR */
105 {1, 1, 1, 1, 0, 0, 0, 0}, /* CW */
106 {1, 1, 1, 0, 1, 0, 0, 0}, /* PR */
107 {1, 1, 1, 0, 0, 0, 0, 0}, /* PW */
108 {1, 1, 0, 0, 0, 0, 0, 0}, /* EX */
109 {0, 0, 0, 0, 0, 0, 0, 0} /* PD */
110 };
111
112 /*
113 * This defines the direction of transfer of LVB data.
114 * Granted mode is the row; requested mode is the column.
115 * Usage: matrix[grmode+1][rqmode+1]
116 * 1 = LVB is returned to the caller
117 * 0 = LVB is written to the resource
118 * -1 = nothing happens to the LVB
119 */
120
121 const int dlm_lvb_operations[8][8] = {
122 /* UN NL CR CW PR PW EX PD*/
123 { -1, 1, 1, 1, 1, 1, 1, -1 }, /* UN */
124 { -1, 1, 1, 1, 1, 1, 1, 0 }, /* NL */
125 { -1, -1, 1, 1, 1, 1, 1, 0 }, /* CR */
126 { -1, -1, -1, 1, 1, 1, 1, 0 }, /* CW */
127 { -1, -1, -1, -1, 1, 1, 1, 0 }, /* PR */
128 { -1, 0, 0, 0, 0, 0, 1, 0 }, /* PW */
129 { -1, 0, 0, 0, 0, 0, 0, 0 }, /* EX */
130 { -1, 0, 0, 0, 0, 0, 0, 0 } /* PD */
131 };
132
133 #define modes_compat(gr, rq) \
134 __dlm_compat_matrix[(gr)->lkb_grmode + 1][(rq)->lkb_rqmode + 1]
135
136 int dlm_modes_compat(int mode1, int mode2)
137 {
138 return __dlm_compat_matrix[mode1 + 1][mode2 + 1];
139 }
140
141 /*
142 * Compatibility matrix for conversions with QUECVT set.
143 * Granted mode is the row; requested mode is the column.
144 * Usage: matrix[grmode+1][rqmode+1]
145 */
146
147 static const int __quecvt_compat_matrix[8][8] = {
148 /* UN NL CR CW PR PW EX PD */
149 {0, 0, 0, 0, 0, 0, 0, 0}, /* UN */
150 {0, 0, 1, 1, 1, 1, 1, 0}, /* NL */
151 {0, 0, 0, 1, 1, 1, 1, 0}, /* CR */
152 {0, 0, 0, 0, 1, 1, 1, 0}, /* CW */
153 {0, 0, 0, 1, 0, 1, 1, 0}, /* PR */
154 {0, 0, 0, 0, 0, 0, 1, 0}, /* PW */
155 {0, 0, 0, 0, 0, 0, 0, 0}, /* EX */
156 {0, 0, 0, 0, 0, 0, 0, 0} /* PD */
157 };
158
159 void dlm_print_lkb(struct dlm_lkb *lkb)
160 {
161 printk(KERN_ERR "lkb: nodeid %d id %x remid %x exflags %x flags %x\n"
162 " status %d rqmode %d grmode %d wait_type %d ast_type %d\n",
163 lkb->lkb_nodeid, lkb->lkb_id, lkb->lkb_remid, lkb->lkb_exflags,
164 lkb->lkb_flags, lkb->lkb_status, lkb->lkb_rqmode,
165 lkb->lkb_grmode, lkb->lkb_wait_type, lkb->lkb_ast_type);
166 }
167
168 static void dlm_print_rsb(struct dlm_rsb *r)
169 {
170 printk(KERN_ERR "rsb: nodeid %d flags %lx first %x rlc %d name %s\n",
171 r->res_nodeid, r->res_flags, r->res_first_lkid,
172 r->res_recover_locks_count, r->res_name);
173 }
174
175 void dlm_dump_rsb(struct dlm_rsb *r)
176 {
177 struct dlm_lkb *lkb;
178
179 dlm_print_rsb(r);
180
181 printk(KERN_ERR "rsb: root_list empty %d recover_list empty %d\n",
182 list_empty(&r->res_root_list), list_empty(&r->res_recover_list));
183 printk(KERN_ERR "rsb lookup list\n");
184 list_for_each_entry(lkb, &r->res_lookup, lkb_rsb_lookup)
185 dlm_print_lkb(lkb);
186 printk(KERN_ERR "rsb grant queue:\n");
187 list_for_each_entry(lkb, &r->res_grantqueue, lkb_statequeue)
188 dlm_print_lkb(lkb);
189 printk(KERN_ERR "rsb convert queue:\n");
190 list_for_each_entry(lkb, &r->res_convertqueue, lkb_statequeue)
191 dlm_print_lkb(lkb);
192 printk(KERN_ERR "rsb wait queue:\n");
193 list_for_each_entry(lkb, &r->res_waitqueue, lkb_statequeue)
194 dlm_print_lkb(lkb);
195 }
196
197 /* Threads cannot use the lockspace while it's being recovered */
198
199 static inline void dlm_lock_recovery(struct dlm_ls *ls)
200 {
201 down_read(&ls->ls_in_recovery);
202 }
203
204 void dlm_unlock_recovery(struct dlm_ls *ls)
205 {
206 up_read(&ls->ls_in_recovery);
207 }
208
209 int dlm_lock_recovery_try(struct dlm_ls *ls)
210 {
211 return down_read_trylock(&ls->ls_in_recovery);
212 }
213
214 static inline int can_be_queued(struct dlm_lkb *lkb)
215 {
216 return !(lkb->lkb_exflags & DLM_LKF_NOQUEUE);
217 }
218
219 static inline int force_blocking_asts(struct dlm_lkb *lkb)
220 {
221 return (lkb->lkb_exflags & DLM_LKF_NOQUEUEBAST);
222 }
223
224 static inline int is_demoted(struct dlm_lkb *lkb)
225 {
226 return (lkb->lkb_sbflags & DLM_SBF_DEMOTED);
227 }
228
229 static inline int is_altmode(struct dlm_lkb *lkb)
230 {
231 return (lkb->lkb_sbflags & DLM_SBF_ALTMODE);
232 }
233
234 static inline int is_granted(struct dlm_lkb *lkb)
235 {
236 return (lkb->lkb_status == DLM_LKSTS_GRANTED);
237 }
238
239 static inline int is_remote(struct dlm_rsb *r)
240 {
241 DLM_ASSERT(r->res_nodeid >= 0, dlm_print_rsb(r););
242 return !!r->res_nodeid;
243 }
244
245 static inline int is_process_copy(struct dlm_lkb *lkb)
246 {
247 return (lkb->lkb_nodeid && !(lkb->lkb_flags & DLM_IFL_MSTCPY));
248 }
249
250 static inline int is_master_copy(struct dlm_lkb *lkb)
251 {
252 if (lkb->lkb_flags & DLM_IFL_MSTCPY)
253 DLM_ASSERT(lkb->lkb_nodeid, dlm_print_lkb(lkb););
254 return (lkb->lkb_flags & DLM_IFL_MSTCPY) ? 1 : 0;
255 }
256
257 static inline int middle_conversion(struct dlm_lkb *lkb)
258 {
259 if ((lkb->lkb_grmode==DLM_LOCK_PR && lkb->lkb_rqmode==DLM_LOCK_CW) ||
260 (lkb->lkb_rqmode==DLM_LOCK_PR && lkb->lkb_grmode==DLM_LOCK_CW))
261 return 1;
262 return 0;
263 }
264
265 static inline int down_conversion(struct dlm_lkb *lkb)
266 {
267 return (!middle_conversion(lkb) && lkb->lkb_rqmode < lkb->lkb_grmode);
268 }
269
270 static inline int is_overlap_unlock(struct dlm_lkb *lkb)
271 {
272 return lkb->lkb_flags & DLM_IFL_OVERLAP_UNLOCK;
273 }
274
275 static inline int is_overlap_cancel(struct dlm_lkb *lkb)
276 {
277 return lkb->lkb_flags & DLM_IFL_OVERLAP_CANCEL;
278 }
279
280 static inline int is_overlap(struct dlm_lkb *lkb)
281 {
282 return (lkb->lkb_flags & (DLM_IFL_OVERLAP_UNLOCK |
283 DLM_IFL_OVERLAP_CANCEL));
284 }
285
286 static void queue_cast(struct dlm_rsb *r, struct dlm_lkb *lkb, int rv)
287 {
288 if (is_master_copy(lkb))
289 return;
290
291 del_timeout(lkb);
292
293 DLM_ASSERT(lkb->lkb_lksb, dlm_print_lkb(lkb););
294
295 /* if the operation was a cancel, then return -DLM_ECANCEL, if a
296 timeout caused the cancel then return -ETIMEDOUT */
297 if (rv == -DLM_ECANCEL && (lkb->lkb_flags & DLM_IFL_TIMEOUT_CANCEL)) {
298 lkb->lkb_flags &= ~DLM_IFL_TIMEOUT_CANCEL;
299 rv = -ETIMEDOUT;
300 }
301
302 if (rv == -DLM_ECANCEL && (lkb->lkb_flags & DLM_IFL_DEADLOCK_CANCEL)) {
303 lkb->lkb_flags &= ~DLM_IFL_DEADLOCK_CANCEL;
304 rv = -EDEADLK;
305 }
306
307 lkb->lkb_lksb->sb_status = rv;
308 lkb->lkb_lksb->sb_flags = lkb->lkb_sbflags;
309
310 dlm_add_ast(lkb, AST_COMP, 0);
311 }
312
313 static inline void queue_cast_overlap(struct dlm_rsb *r, struct dlm_lkb *lkb)
314 {
315 queue_cast(r, lkb,
316 is_overlap_unlock(lkb) ? -DLM_EUNLOCK : -DLM_ECANCEL);
317 }
318
319 static void queue_bast(struct dlm_rsb *r, struct dlm_lkb *lkb, int rqmode)
320 {
321 lkb->lkb_time_bast = ktime_get();
322
323 if (is_master_copy(lkb))
324 send_bast(r, lkb, rqmode);
325 else
326 dlm_add_ast(lkb, AST_BAST, rqmode);
327 }
328
329 /*
330 * Basic operations on rsb's and lkb's
331 */
332
333 static struct dlm_rsb *create_rsb(struct dlm_ls *ls, char *name, int len)
334 {
335 struct dlm_rsb *r;
336
337 r = dlm_allocate_rsb(ls, len);
338 if (!r)
339 return NULL;
340
341 r->res_ls = ls;
342 r->res_length = len;
343 memcpy(r->res_name, name, len);
344 mutex_init(&r->res_mutex);
345
346 INIT_LIST_HEAD(&r->res_lookup);
347 INIT_LIST_HEAD(&r->res_grantqueue);
348 INIT_LIST_HEAD(&r->res_convertqueue);
349 INIT_LIST_HEAD(&r->res_waitqueue);
350 INIT_LIST_HEAD(&r->res_root_list);
351 INIT_LIST_HEAD(&r->res_recover_list);
352
353 return r;
354 }
355
356 static int search_rsb_list(struct list_head *head, char *name, int len,
357 unsigned int flags, struct dlm_rsb **r_ret)
358 {
359 struct dlm_rsb *r;
360 int error = 0;
361
362 list_for_each_entry(r, head, res_hashchain) {
363 if (len == r->res_length && !memcmp(name, r->res_name, len))
364 goto found;
365 }
366 *r_ret = NULL;
367 return -EBADR;
368
369 found:
370 if (r->res_nodeid && (flags & R_MASTER))
371 error = -ENOTBLK;
372 *r_ret = r;
373 return error;
374 }
375
376 static int _search_rsb(struct dlm_ls *ls, char *name, int len, int b,
377 unsigned int flags, struct dlm_rsb **r_ret)
378 {
379 struct dlm_rsb *r;
380 int error;
381
382 error = search_rsb_list(&ls->ls_rsbtbl[b].list, name, len, flags, &r);
383 if (!error) {
384 kref_get(&r->res_ref);
385 goto out;
386 }
387 error = search_rsb_list(&ls->ls_rsbtbl[b].toss, name, len, flags, &r);
388 if (error)
389 goto out;
390
391 list_move(&r->res_hashchain, &ls->ls_rsbtbl[b].list);
392
393 if (dlm_no_directory(ls))
394 goto out;
395
396 if (r->res_nodeid == -1) {
397 rsb_clear_flag(r, RSB_MASTER_UNCERTAIN);
398 r->res_first_lkid = 0;
399 } else if (r->res_nodeid > 0) {
400 rsb_set_flag(r, RSB_MASTER_UNCERTAIN);
401 r->res_first_lkid = 0;
402 } else {
403 DLM_ASSERT(r->res_nodeid == 0, dlm_print_rsb(r););
404 DLM_ASSERT(!rsb_flag(r, RSB_MASTER_UNCERTAIN),);
405 }
406 out:
407 *r_ret = r;
408 return error;
409 }
410
411 static int search_rsb(struct dlm_ls *ls, char *name, int len, int b,
412 unsigned int flags, struct dlm_rsb **r_ret)
413 {
414 int error;
415 spin_lock(&ls->ls_rsbtbl[b].lock);
416 error = _search_rsb(ls, name, len, b, flags, r_ret);
417 spin_unlock(&ls->ls_rsbtbl[b].lock);
418 return error;
419 }
420
421 /*
422 * Find rsb in rsbtbl and potentially create/add one
423 *
424 * Delaying the release of rsb's has a similar benefit to applications keeping
425 * NL locks on an rsb, but without the guarantee that the cached master value
426 * will still be valid when the rsb is reused. Apps aren't always smart enough
427 * to keep NL locks on an rsb that they may lock again shortly; this can lead
428 * to excessive master lookups and removals if we don't delay the release.
429 *
430 * Searching for an rsb means looking through both the normal list and toss
431 * list. When found on the toss list the rsb is moved to the normal list with
432 * ref count of 1; when found on normal list the ref count is incremented.
433 */
434
435 static int find_rsb(struct dlm_ls *ls, char *name, int namelen,
436 unsigned int flags, struct dlm_rsb **r_ret)
437 {
438 struct dlm_rsb *r = NULL, *tmp;
439 uint32_t hash, bucket;
440 int error = -EINVAL;
441
442 if (namelen > DLM_RESNAME_MAXLEN)
443 goto out;
444
445 if (dlm_no_directory(ls))
446 flags |= R_CREATE;
447
448 error = 0;
449 hash = jhash(name, namelen, 0);
450 bucket = hash & (ls->ls_rsbtbl_size - 1);
451
452 error = search_rsb(ls, name, namelen, bucket, flags, &r);
453 if (!error)
454 goto out;
455
456 if (error == -EBADR && !(flags & R_CREATE))
457 goto out;
458
459 /* the rsb was found but wasn't a master copy */
460 if (error == -ENOTBLK)
461 goto out;
462
463 error = -ENOMEM;
464 r = create_rsb(ls, name, namelen);
465 if (!r)
466 goto out;
467
468 r->res_hash = hash;
469 r->res_bucket = bucket;
470 r->res_nodeid = -1;
471 kref_init(&r->res_ref);
472
473 /* With no directory, the master can be set immediately */
474 if (dlm_no_directory(ls)) {
475 int nodeid = dlm_dir_nodeid(r);
476 if (nodeid == dlm_our_nodeid())
477 nodeid = 0;
478 r->res_nodeid = nodeid;
479 }
480
481 spin_lock(&ls->ls_rsbtbl[bucket].lock);
482 error = _search_rsb(ls, name, namelen, bucket, 0, &tmp);
483 if (!error) {
484 spin_unlock(&ls->ls_rsbtbl[bucket].lock);
485 dlm_free_rsb(r);
486 r = tmp;
487 goto out;
488 }
489 list_add(&r->res_hashchain, &ls->ls_rsbtbl[bucket].list);
490 spin_unlock(&ls->ls_rsbtbl[bucket].lock);
491 error = 0;
492 out:
493 *r_ret = r;
494 return error;
495 }
496
497 /* This is only called to add a reference when the code already holds
498 a valid reference to the rsb, so there's no need for locking. */
499
500 static inline void hold_rsb(struct dlm_rsb *r)
501 {
502 kref_get(&r->res_ref);
503 }
504
505 void dlm_hold_rsb(struct dlm_rsb *r)
506 {
507 hold_rsb(r);
508 }
509
510 static void toss_rsb(struct kref *kref)
511 {
512 struct dlm_rsb *r = container_of(kref, struct dlm_rsb, res_ref);
513 struct dlm_ls *ls = r->res_ls;
514
515 DLM_ASSERT(list_empty(&r->res_root_list), dlm_print_rsb(r););
516 kref_init(&r->res_ref);
517 list_move(&r->res_hashchain, &ls->ls_rsbtbl[r->res_bucket].toss);
518 r->res_toss_time = jiffies;
519 if (r->res_lvbptr) {
520 dlm_free_lvb(r->res_lvbptr);
521 r->res_lvbptr = NULL;
522 }
523 }
524
525 /* When all references to the rsb are gone it's transfered to
526 the tossed list for later disposal. */
527
528 static void put_rsb(struct dlm_rsb *r)
529 {
530 struct dlm_ls *ls = r->res_ls;
531 uint32_t bucket = r->res_bucket;
532
533 spin_lock(&ls->ls_rsbtbl[bucket].lock);
534 kref_put(&r->res_ref, toss_rsb);
535 spin_unlock(&ls->ls_rsbtbl[bucket].lock);
536 }
537
538 void dlm_put_rsb(struct dlm_rsb *r)
539 {
540 put_rsb(r);
541 }
542
543 /* See comment for unhold_lkb */
544
545 static void unhold_rsb(struct dlm_rsb *r)
546 {
547 int rv;
548 rv = kref_put(&r->res_ref, toss_rsb);
549 DLM_ASSERT(!rv, dlm_dump_rsb(r););
550 }
551
552 static void kill_rsb(struct kref *kref)
553 {
554 struct dlm_rsb *r = container_of(kref, struct dlm_rsb, res_ref);
555
556 /* All work is done after the return from kref_put() so we
557 can release the write_lock before the remove and free. */
558
559 DLM_ASSERT(list_empty(&r->res_lookup), dlm_dump_rsb(r););
560 DLM_ASSERT(list_empty(&r->res_grantqueue), dlm_dump_rsb(r););
561 DLM_ASSERT(list_empty(&r->res_convertqueue), dlm_dump_rsb(r););
562 DLM_ASSERT(list_empty(&r->res_waitqueue), dlm_dump_rsb(r););
563 DLM_ASSERT(list_empty(&r->res_root_list), dlm_dump_rsb(r););
564 DLM_ASSERT(list_empty(&r->res_recover_list), dlm_dump_rsb(r););
565 }
566
567 /* Attaching/detaching lkb's from rsb's is for rsb reference counting.
568 The rsb must exist as long as any lkb's for it do. */
569
570 static void attach_lkb(struct dlm_rsb *r, struct dlm_lkb *lkb)
571 {
572 hold_rsb(r);
573 lkb->lkb_resource = r;
574 }
575
576 static void detach_lkb(struct dlm_lkb *lkb)
577 {
578 if (lkb->lkb_resource) {
579 put_rsb(lkb->lkb_resource);
580 lkb->lkb_resource = NULL;
581 }
582 }
583
584 static int create_lkb(struct dlm_ls *ls, struct dlm_lkb **lkb_ret)
585 {
586 struct dlm_lkb *lkb, *tmp;
587 uint32_t lkid = 0;
588 uint16_t bucket;
589
590 lkb = dlm_allocate_lkb(ls);
591 if (!lkb)
592 return -ENOMEM;
593
594 lkb->lkb_nodeid = -1;
595 lkb->lkb_grmode = DLM_LOCK_IV;
596 kref_init(&lkb->lkb_ref);
597 INIT_LIST_HEAD(&lkb->lkb_ownqueue);
598 INIT_LIST_HEAD(&lkb->lkb_rsb_lookup);
599 INIT_LIST_HEAD(&lkb->lkb_time_list);
600
601 get_random_bytes(&bucket, sizeof(bucket));
602 bucket &= (ls->ls_lkbtbl_size - 1);
603
604 write_lock(&ls->ls_lkbtbl[bucket].lock);
605
606 /* counter can roll over so we must verify lkid is not in use */
607
608 while (lkid == 0) {
609 lkid = (bucket << 16) | ls->ls_lkbtbl[bucket].counter++;
610
611 list_for_each_entry(tmp, &ls->ls_lkbtbl[bucket].list,
612 lkb_idtbl_list) {
613 if (tmp->lkb_id != lkid)
614 continue;
615 lkid = 0;
616 break;
617 }
618 }
619
620 lkb->lkb_id = lkid;
621 list_add(&lkb->lkb_idtbl_list, &ls->ls_lkbtbl[bucket].list);
622 write_unlock(&ls->ls_lkbtbl[bucket].lock);
623
624 *lkb_ret = lkb;
625 return 0;
626 }
627
628 static struct dlm_lkb *__find_lkb(struct dlm_ls *ls, uint32_t lkid)
629 {
630 struct dlm_lkb *lkb;
631 uint16_t bucket = (lkid >> 16);
632
633 list_for_each_entry(lkb, &ls->ls_lkbtbl[bucket].list, lkb_idtbl_list) {
634 if (lkb->lkb_id == lkid)
635 return lkb;
636 }
637 return NULL;
638 }
639
640 static int find_lkb(struct dlm_ls *ls, uint32_t lkid, struct dlm_lkb **lkb_ret)
641 {
642 struct dlm_lkb *lkb;
643 uint16_t bucket = (lkid >> 16);
644
645 if (bucket >= ls->ls_lkbtbl_size)
646 return -EBADSLT;
647
648 read_lock(&ls->ls_lkbtbl[bucket].lock);
649 lkb = __find_lkb(ls, lkid);
650 if (lkb)
651 kref_get(&lkb->lkb_ref);
652 read_unlock(&ls->ls_lkbtbl[bucket].lock);
653
654 *lkb_ret = lkb;
655 return lkb ? 0 : -ENOENT;
656 }
657
658 static void kill_lkb(struct kref *kref)
659 {
660 struct dlm_lkb *lkb = container_of(kref, struct dlm_lkb, lkb_ref);
661
662 /* All work is done after the return from kref_put() so we
663 can release the write_lock before the detach_lkb */
664
665 DLM_ASSERT(!lkb->lkb_status, dlm_print_lkb(lkb););
666 }
667
668 /* __put_lkb() is used when an lkb may not have an rsb attached to
669 it so we need to provide the lockspace explicitly */
670
671 static int __put_lkb(struct dlm_ls *ls, struct dlm_lkb *lkb)
672 {
673 uint16_t bucket = (lkb->lkb_id >> 16);
674
675 write_lock(&ls->ls_lkbtbl[bucket].lock);
676 if (kref_put(&lkb->lkb_ref, kill_lkb)) {
677 list_del(&lkb->lkb_idtbl_list);
678 write_unlock(&ls->ls_lkbtbl[bucket].lock);
679
680 detach_lkb(lkb);
681
682 /* for local/process lkbs, lvbptr points to caller's lksb */
683 if (lkb->lkb_lvbptr && is_master_copy(lkb))
684 dlm_free_lvb(lkb->lkb_lvbptr);
685 dlm_free_lkb(lkb);
686 return 1;
687 } else {
688 write_unlock(&ls->ls_lkbtbl[bucket].lock);
689 return 0;
690 }
691 }
692
693 int dlm_put_lkb(struct dlm_lkb *lkb)
694 {
695 struct dlm_ls *ls;
696
697 DLM_ASSERT(lkb->lkb_resource, dlm_print_lkb(lkb););
698 DLM_ASSERT(lkb->lkb_resource->res_ls, dlm_print_lkb(lkb););
699
700 ls = lkb->lkb_resource->res_ls;
701 return __put_lkb(ls, lkb);
702 }
703
704 /* This is only called to add a reference when the code already holds
705 a valid reference to the lkb, so there's no need for locking. */
706
707 static inline void hold_lkb(struct dlm_lkb *lkb)
708 {
709 kref_get(&lkb->lkb_ref);
710 }
711
712 /* This is called when we need to remove a reference and are certain
713 it's not the last ref. e.g. del_lkb is always called between a
714 find_lkb/put_lkb and is always the inverse of a previous add_lkb.
715 put_lkb would work fine, but would involve unnecessary locking */
716
717 static inline void unhold_lkb(struct dlm_lkb *lkb)
718 {
719 int rv;
720 rv = kref_put(&lkb->lkb_ref, kill_lkb);
721 DLM_ASSERT(!rv, dlm_print_lkb(lkb););
722 }
723
724 static void lkb_add_ordered(struct list_head *new, struct list_head *head,
725 int mode)
726 {
727 struct dlm_lkb *lkb = NULL;
728
729 list_for_each_entry(lkb, head, lkb_statequeue)
730 if (lkb->lkb_rqmode < mode)
731 break;
732
733 if (!lkb)
734 list_add_tail(new, head);
735 else
736 __list_add(new, lkb->lkb_statequeue.prev, &lkb->lkb_statequeue);
737 }
738
739 /* add/remove lkb to rsb's grant/convert/wait queue */
740
741 static void add_lkb(struct dlm_rsb *r, struct dlm_lkb *lkb, int status)
742 {
743 kref_get(&lkb->lkb_ref);
744
745 DLM_ASSERT(!lkb->lkb_status, dlm_print_lkb(lkb););
746
747 lkb->lkb_timestamp = ktime_get();
748
749 lkb->lkb_status = status;
750
751 switch (status) {
752 case DLM_LKSTS_WAITING:
753 if (lkb->lkb_exflags & DLM_LKF_HEADQUE)
754 list_add(&lkb->lkb_statequeue, &r->res_waitqueue);
755 else
756 list_add_tail(&lkb->lkb_statequeue, &r->res_waitqueue);
757 break;
758 case DLM_LKSTS_GRANTED:
759 /* convention says granted locks kept in order of grmode */
760 lkb_add_ordered(&lkb->lkb_statequeue, &r->res_grantqueue,
761 lkb->lkb_grmode);
762 break;
763 case DLM_LKSTS_CONVERT:
764 if (lkb->lkb_exflags & DLM_LKF_HEADQUE)
765 list_add(&lkb->lkb_statequeue, &r->res_convertqueue);
766 else
767 list_add_tail(&lkb->lkb_statequeue,
768 &r->res_convertqueue);
769 break;
770 default:
771 DLM_ASSERT(0, dlm_print_lkb(lkb); printk("sts=%d\n", status););
772 }
773 }
774
775 static void del_lkb(struct dlm_rsb *r, struct dlm_lkb *lkb)
776 {
777 lkb->lkb_status = 0;
778 list_del(&lkb->lkb_statequeue);
779 unhold_lkb(lkb);
780 }
781
782 static void move_lkb(struct dlm_rsb *r, struct dlm_lkb *lkb, int sts)
783 {
784 hold_lkb(lkb);
785 del_lkb(r, lkb);
786 add_lkb(r, lkb, sts);
787 unhold_lkb(lkb);
788 }
789
790 static int msg_reply_type(int mstype)
791 {
792 switch (mstype) {
793 case DLM_MSG_REQUEST:
794 return DLM_MSG_REQUEST_REPLY;
795 case DLM_MSG_CONVERT:
796 return DLM_MSG_CONVERT_REPLY;
797 case DLM_MSG_UNLOCK:
798 return DLM_MSG_UNLOCK_REPLY;
799 case DLM_MSG_CANCEL:
800 return DLM_MSG_CANCEL_REPLY;
801 case DLM_MSG_LOOKUP:
802 return DLM_MSG_LOOKUP_REPLY;
803 }
804 return -1;
805 }
806
807 /* add/remove lkb from global waiters list of lkb's waiting for
808 a reply from a remote node */
809
810 static int add_to_waiters(struct dlm_lkb *lkb, int mstype)
811 {
812 struct dlm_ls *ls = lkb->lkb_resource->res_ls;
813 int error = 0;
814
815 mutex_lock(&ls->ls_waiters_mutex);
816
817 if (is_overlap_unlock(lkb) ||
818 (is_overlap_cancel(lkb) && (mstype == DLM_MSG_CANCEL))) {
819 error = -EINVAL;
820 goto out;
821 }
822
823 if (lkb->lkb_wait_type || is_overlap_cancel(lkb)) {
824 switch (mstype) {
825 case DLM_MSG_UNLOCK:
826 lkb->lkb_flags |= DLM_IFL_OVERLAP_UNLOCK;
827 break;
828 case DLM_MSG_CANCEL:
829 lkb->lkb_flags |= DLM_IFL_OVERLAP_CANCEL;
830 break;
831 default:
832 error = -EBUSY;
833 goto out;
834 }
835 lkb->lkb_wait_count++;
836 hold_lkb(lkb);
837
838 log_debug(ls, "addwait %x cur %d overlap %d count %d f %x",
839 lkb->lkb_id, lkb->lkb_wait_type, mstype,
840 lkb->lkb_wait_count, lkb->lkb_flags);
841 goto out;
842 }
843
844 DLM_ASSERT(!lkb->lkb_wait_count,
845 dlm_print_lkb(lkb);
846 printk("wait_count %d\n", lkb->lkb_wait_count););
847
848 lkb->lkb_wait_count++;
849 lkb->lkb_wait_type = mstype;
850 hold_lkb(lkb);
851 list_add(&lkb->lkb_wait_reply, &ls->ls_waiters);
852 out:
853 if (error)
854 log_error(ls, "addwait error %x %d flags %x %d %d %s",
855 lkb->lkb_id, error, lkb->lkb_flags, mstype,
856 lkb->lkb_wait_type, lkb->lkb_resource->res_name);
857 mutex_unlock(&ls->ls_waiters_mutex);
858 return error;
859 }
860
861 /* We clear the RESEND flag because we might be taking an lkb off the waiters
862 list as part of process_requestqueue (e.g. a lookup that has an optimized
863 request reply on the requestqueue) between dlm_recover_waiters_pre() which
864 set RESEND and dlm_recover_waiters_post() */
865
866 static int _remove_from_waiters(struct dlm_lkb *lkb, int mstype,
867 struct dlm_message *ms)
868 {
869 struct dlm_ls *ls = lkb->lkb_resource->res_ls;
870 int overlap_done = 0;
871
872 if (is_overlap_unlock(lkb) && (mstype == DLM_MSG_UNLOCK_REPLY)) {
873 log_debug(ls, "remwait %x unlock_reply overlap", lkb->lkb_id);
874 lkb->lkb_flags &= ~DLM_IFL_OVERLAP_UNLOCK;
875 overlap_done = 1;
876 goto out_del;
877 }
878
879 if (is_overlap_cancel(lkb) && (mstype == DLM_MSG_CANCEL_REPLY)) {
880 log_debug(ls, "remwait %x cancel_reply overlap", lkb->lkb_id);
881 lkb->lkb_flags &= ~DLM_IFL_OVERLAP_CANCEL;
882 overlap_done = 1;
883 goto out_del;
884 }
885
886 /* Cancel state was preemptively cleared by a successful convert,
887 see next comment, nothing to do. */
888
889 if ((mstype == DLM_MSG_CANCEL_REPLY) &&
890 (lkb->lkb_wait_type != DLM_MSG_CANCEL)) {
891 log_debug(ls, "remwait %x cancel_reply wait_type %d",
892 lkb->lkb_id, lkb->lkb_wait_type);
893 return -1;
894 }
895
896 /* Remove for the convert reply, and premptively remove for the
897 cancel reply. A convert has been granted while there's still
898 an outstanding cancel on it (the cancel is moot and the result
899 in the cancel reply should be 0). We preempt the cancel reply
900 because the app gets the convert result and then can follow up
901 with another op, like convert. This subsequent op would see the
902 lingering state of the cancel and fail with -EBUSY. */
903
904 if ((mstype == DLM_MSG_CONVERT_REPLY) &&
905 (lkb->lkb_wait_type == DLM_MSG_CONVERT) &&
906 is_overlap_cancel(lkb) && ms && !ms->m_result) {
907 log_debug(ls, "remwait %x convert_reply zap overlap_cancel",
908 lkb->lkb_id);
909 lkb->lkb_wait_type = 0;
910 lkb->lkb_flags &= ~DLM_IFL_OVERLAP_CANCEL;
911 lkb->lkb_wait_count--;
912 goto out_del;
913 }
914
915 /* N.B. type of reply may not always correspond to type of original
916 msg due to lookup->request optimization, verify others? */
917
918 if (lkb->lkb_wait_type) {
919 lkb->lkb_wait_type = 0;
920 goto out_del;
921 }
922
923 log_error(ls, "remwait error %x reply %d flags %x no wait_type",
924 lkb->lkb_id, mstype, lkb->lkb_flags);
925 return -1;
926
927 out_del:
928 /* the force-unlock/cancel has completed and we haven't recvd a reply
929 to the op that was in progress prior to the unlock/cancel; we
930 give up on any reply to the earlier op. FIXME: not sure when/how
931 this would happen */
932
933 if (overlap_done && lkb->lkb_wait_type) {
934 log_error(ls, "remwait error %x reply %d wait_type %d overlap",
935 lkb->lkb_id, mstype, lkb->lkb_wait_type);
936 lkb->lkb_wait_count--;
937 lkb->lkb_wait_type = 0;
938 }
939
940 DLM_ASSERT(lkb->lkb_wait_count, dlm_print_lkb(lkb););
941
942 lkb->lkb_flags &= ~DLM_IFL_RESEND;
943 lkb->lkb_wait_count--;
944 if (!lkb->lkb_wait_count)
945 list_del_init(&lkb->lkb_wait_reply);
946 unhold_lkb(lkb);
947 return 0;
948 }
949
950 static int remove_from_waiters(struct dlm_lkb *lkb, int mstype)
951 {
952 struct dlm_ls *ls = lkb->lkb_resource->res_ls;
953 int error;
954
955 mutex_lock(&ls->ls_waiters_mutex);
956 error = _remove_from_waiters(lkb, mstype, NULL);
957 mutex_unlock(&ls->ls_waiters_mutex);
958 return error;
959 }
960
961 /* Handles situations where we might be processing a "fake" or "stub" reply in
962 which we can't try to take waiters_mutex again. */
963
964 static int remove_from_waiters_ms(struct dlm_lkb *lkb, struct dlm_message *ms)
965 {
966 struct dlm_ls *ls = lkb->lkb_resource->res_ls;
967 int error;
968
969 if (ms != &ls->ls_stub_ms)
970 mutex_lock(&ls->ls_waiters_mutex);
971 error = _remove_from_waiters(lkb, ms->m_type, ms);
972 if (ms != &ls->ls_stub_ms)
973 mutex_unlock(&ls->ls_waiters_mutex);
974 return error;
975 }
976
977 static void dir_remove(struct dlm_rsb *r)
978 {
979 int to_nodeid;
980
981 if (dlm_no_directory(r->res_ls))
982 return;
983
984 to_nodeid = dlm_dir_nodeid(r);
985 if (to_nodeid != dlm_our_nodeid())
986 send_remove(r);
987 else
988 dlm_dir_remove_entry(r->res_ls, to_nodeid,
989 r->res_name, r->res_length);
990 }
991
992 /* FIXME: shouldn't this be able to exit as soon as one non-due rsb is
993 found since they are in order of newest to oldest? */
994
995 static int shrink_bucket(struct dlm_ls *ls, int b)
996 {
997 struct dlm_rsb *r;
998 int count = 0, found;
999
1000 for (;;) {
1001 found = 0;
1002 spin_lock(&ls->ls_rsbtbl[b].lock);
1003 list_for_each_entry_reverse(r, &ls->ls_rsbtbl[b].toss,
1004 res_hashchain) {
1005 if (!time_after_eq(jiffies, r->res_toss_time +
1006 dlm_config.ci_toss_secs * HZ))
1007 continue;
1008 found = 1;
1009 break;
1010 }
1011
1012 if (!found) {
1013 spin_unlock(&ls->ls_rsbtbl[b].lock);
1014 break;
1015 }
1016
1017 if (kref_put(&r->res_ref, kill_rsb)) {
1018 list_del(&r->res_hashchain);
1019 spin_unlock(&ls->ls_rsbtbl[b].lock);
1020
1021 if (is_master(r))
1022 dir_remove(r);
1023 dlm_free_rsb(r);
1024 count++;
1025 } else {
1026 spin_unlock(&ls->ls_rsbtbl[b].lock);
1027 log_error(ls, "tossed rsb in use %s", r->res_name);
1028 }
1029 }
1030
1031 return count;
1032 }
1033
1034 void dlm_scan_rsbs(struct dlm_ls *ls)
1035 {
1036 int i;
1037
1038 for (i = 0; i < ls->ls_rsbtbl_size; i++) {
1039 shrink_bucket(ls, i);
1040 if (dlm_locking_stopped(ls))
1041 break;
1042 cond_resched();
1043 }
1044 }
1045
1046 static void add_timeout(struct dlm_lkb *lkb)
1047 {
1048 struct dlm_ls *ls = lkb->lkb_resource->res_ls;
1049
1050 if (is_master_copy(lkb))
1051 return;
1052
1053 if (test_bit(LSFL_TIMEWARN, &ls->ls_flags) &&
1054 !(lkb->lkb_exflags & DLM_LKF_NODLCKWT)) {
1055 lkb->lkb_flags |= DLM_IFL_WATCH_TIMEWARN;
1056 goto add_it;
1057 }
1058 if (lkb->lkb_exflags & DLM_LKF_TIMEOUT)
1059 goto add_it;
1060 return;
1061
1062 add_it:
1063 DLM_ASSERT(list_empty(&lkb->lkb_time_list), dlm_print_lkb(lkb););
1064 mutex_lock(&ls->ls_timeout_mutex);
1065 hold_lkb(lkb);
1066 list_add_tail(&lkb->lkb_time_list, &ls->ls_timeout);
1067 mutex_unlock(&ls->ls_timeout_mutex);
1068 }
1069
1070 static void del_timeout(struct dlm_lkb *lkb)
1071 {
1072 struct dlm_ls *ls = lkb->lkb_resource->res_ls;
1073
1074 mutex_lock(&ls->ls_timeout_mutex);
1075 if (!list_empty(&lkb->lkb_time_list)) {
1076 list_del_init(&lkb->lkb_time_list);
1077 unhold_lkb(lkb);
1078 }
1079 mutex_unlock(&ls->ls_timeout_mutex);
1080 }
1081
1082 /* FIXME: is it safe to look at lkb_exflags, lkb_flags, lkb_timestamp, and
1083 lkb_lksb_timeout without lock_rsb? Note: we can't lock timeout_mutex
1084 and then lock rsb because of lock ordering in add_timeout. We may need
1085 to specify some special timeout-related bits in the lkb that are just to
1086 be accessed under the timeout_mutex. */
1087
1088 void dlm_scan_timeout(struct dlm_ls *ls)
1089 {
1090 struct dlm_rsb *r;
1091 struct dlm_lkb *lkb;
1092 int do_cancel, do_warn;
1093 s64 wait_us;
1094
1095 for (;;) {
1096 if (dlm_locking_stopped(ls))
1097 break;
1098
1099 do_cancel = 0;
1100 do_warn = 0;
1101 mutex_lock(&ls->ls_timeout_mutex);
1102 list_for_each_entry(lkb, &ls->ls_timeout, lkb_time_list) {
1103
1104 wait_us = ktime_to_us(ktime_sub(ktime_get(),
1105 lkb->lkb_timestamp));
1106
1107 if ((lkb->lkb_exflags & DLM_LKF_TIMEOUT) &&
1108 wait_us >= (lkb->lkb_timeout_cs * 10000))
1109 do_cancel = 1;
1110
1111 if ((lkb->lkb_flags & DLM_IFL_WATCH_TIMEWARN) &&
1112 wait_us >= dlm_config.ci_timewarn_cs * 10000)
1113 do_warn = 1;
1114
1115 if (!do_cancel && !do_warn)
1116 continue;
1117 hold_lkb(lkb);
1118 break;
1119 }
1120 mutex_unlock(&ls->ls_timeout_mutex);
1121
1122 if (!do_cancel && !do_warn)
1123 break;
1124
1125 r = lkb->lkb_resource;
1126 hold_rsb(r);
1127 lock_rsb(r);
1128
1129 if (do_warn) {
1130 /* clear flag so we only warn once */
1131 lkb->lkb_flags &= ~DLM_IFL_WATCH_TIMEWARN;
1132 if (!(lkb->lkb_exflags & DLM_LKF_TIMEOUT))
1133 del_timeout(lkb);
1134 dlm_timeout_warn(lkb);
1135 }
1136
1137 if (do_cancel) {
1138 log_debug(ls, "timeout cancel %x node %d %s",
1139 lkb->lkb_id, lkb->lkb_nodeid, r->res_name);
1140 lkb->lkb_flags &= ~DLM_IFL_WATCH_TIMEWARN;
1141 lkb->lkb_flags |= DLM_IFL_TIMEOUT_CANCEL;
1142 del_timeout(lkb);
1143 _cancel_lock(r, lkb);
1144 }
1145
1146 unlock_rsb(r);
1147 unhold_rsb(r);
1148 dlm_put_lkb(lkb);
1149 }
1150 }
1151
1152 /* This is only called by dlm_recoverd, and we rely on dlm_ls_stop() stopping
1153 dlm_recoverd before checking/setting ls_recover_begin. */
1154
1155 void dlm_adjust_timeouts(struct dlm_ls *ls)
1156 {
1157 struct dlm_lkb *lkb;
1158 u64 adj_us = jiffies_to_usecs(jiffies - ls->ls_recover_begin);
1159
1160 ls->ls_recover_begin = 0;
1161 mutex_lock(&ls->ls_timeout_mutex);
1162 list_for_each_entry(lkb, &ls->ls_timeout, lkb_time_list)
1163 lkb->lkb_timestamp = ktime_add_us(lkb->lkb_timestamp, adj_us);
1164 mutex_unlock(&ls->ls_timeout_mutex);
1165 }
1166
1167 /* lkb is master or local copy */
1168
1169 static void set_lvb_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
1170 {
1171 int b, len = r->res_ls->ls_lvblen;
1172
1173 /* b=1 lvb returned to caller
1174 b=0 lvb written to rsb or invalidated
1175 b=-1 do nothing */
1176
1177 b = dlm_lvb_operations[lkb->lkb_grmode + 1][lkb->lkb_rqmode + 1];
1178
1179 if (b == 1) {
1180 if (!lkb->lkb_lvbptr)
1181 return;
1182
1183 if (!(lkb->lkb_exflags & DLM_LKF_VALBLK))
1184 return;
1185
1186 if (!r->res_lvbptr)
1187 return;
1188
1189 memcpy(lkb->lkb_lvbptr, r->res_lvbptr, len);
1190 lkb->lkb_lvbseq = r->res_lvbseq;
1191
1192 } else if (b == 0) {
1193 if (lkb->lkb_exflags & DLM_LKF_IVVALBLK) {
1194 rsb_set_flag(r, RSB_VALNOTVALID);
1195 return;
1196 }
1197
1198 if (!lkb->lkb_lvbptr)
1199 return;
1200
1201 if (!(lkb->lkb_exflags & DLM_LKF_VALBLK))
1202 return;
1203
1204 if (!r->res_lvbptr)
1205 r->res_lvbptr = dlm_allocate_lvb(r->res_ls);
1206
1207 if (!r->res_lvbptr)
1208 return;
1209
1210 memcpy(r->res_lvbptr, lkb->lkb_lvbptr, len);
1211 r->res_lvbseq++;
1212 lkb->lkb_lvbseq = r->res_lvbseq;
1213 rsb_clear_flag(r, RSB_VALNOTVALID);
1214 }
1215
1216 if (rsb_flag(r, RSB_VALNOTVALID))
1217 lkb->lkb_sbflags |= DLM_SBF_VALNOTVALID;
1218 }
1219
1220 static void set_lvb_unlock(struct dlm_rsb *r, struct dlm_lkb *lkb)
1221 {
1222 if (lkb->lkb_grmode < DLM_LOCK_PW)
1223 return;
1224
1225 if (lkb->lkb_exflags & DLM_LKF_IVVALBLK) {
1226 rsb_set_flag(r, RSB_VALNOTVALID);
1227 return;
1228 }
1229
1230 if (!lkb->lkb_lvbptr)
1231 return;
1232
1233 if (!(lkb->lkb_exflags & DLM_LKF_VALBLK))
1234 return;
1235
1236 if (!r->res_lvbptr)
1237 r->res_lvbptr = dlm_allocate_lvb(r->res_ls);
1238
1239 if (!r->res_lvbptr)
1240 return;
1241
1242 memcpy(r->res_lvbptr, lkb->lkb_lvbptr, r->res_ls->ls_lvblen);
1243 r->res_lvbseq++;
1244 rsb_clear_flag(r, RSB_VALNOTVALID);
1245 }
1246
1247 /* lkb is process copy (pc) */
1248
1249 static void set_lvb_lock_pc(struct dlm_rsb *r, struct dlm_lkb *lkb,
1250 struct dlm_message *ms)
1251 {
1252 int b;
1253
1254 if (!lkb->lkb_lvbptr)
1255 return;
1256
1257 if (!(lkb->lkb_exflags & DLM_LKF_VALBLK))
1258 return;
1259
1260 b = dlm_lvb_operations[lkb->lkb_grmode + 1][lkb->lkb_rqmode + 1];
1261 if (b == 1) {
1262 int len = receive_extralen(ms);
1263 if (len > DLM_RESNAME_MAXLEN)
1264 len = DLM_RESNAME_MAXLEN;
1265 memcpy(lkb->lkb_lvbptr, ms->m_extra, len);
1266 lkb->lkb_lvbseq = ms->m_lvbseq;
1267 }
1268 }
1269
1270 /* Manipulate lkb's on rsb's convert/granted/waiting queues
1271 remove_lock -- used for unlock, removes lkb from granted
1272 revert_lock -- used for cancel, moves lkb from convert to granted
1273 grant_lock -- used for request and convert, adds lkb to granted or
1274 moves lkb from convert or waiting to granted
1275
1276 Each of these is used for master or local copy lkb's. There is
1277 also a _pc() variation used to make the corresponding change on
1278 a process copy (pc) lkb. */
1279
1280 static void _remove_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
1281 {
1282 del_lkb(r, lkb);
1283 lkb->lkb_grmode = DLM_LOCK_IV;
1284 /* this unhold undoes the original ref from create_lkb()
1285 so this leads to the lkb being freed */
1286 unhold_lkb(lkb);
1287 }
1288
1289 static void remove_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
1290 {
1291 set_lvb_unlock(r, lkb);
1292 _remove_lock(r, lkb);
1293 }
1294
1295 static void remove_lock_pc(struct dlm_rsb *r, struct dlm_lkb *lkb)
1296 {
1297 _remove_lock(r, lkb);
1298 }
1299
1300 /* returns: 0 did nothing
1301 1 moved lock to granted
1302 -1 removed lock */
1303
1304 static int revert_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
1305 {
1306 int rv = 0;
1307
1308 lkb->lkb_rqmode = DLM_LOCK_IV;
1309
1310 switch (lkb->lkb_status) {
1311 case DLM_LKSTS_GRANTED:
1312 break;
1313 case DLM_LKSTS_CONVERT:
1314 move_lkb(r, lkb, DLM_LKSTS_GRANTED);
1315 rv = 1;
1316 break;
1317 case DLM_LKSTS_WAITING:
1318 del_lkb(r, lkb);
1319 lkb->lkb_grmode = DLM_LOCK_IV;
1320 /* this unhold undoes the original ref from create_lkb()
1321 so this leads to the lkb being freed */
1322 unhold_lkb(lkb);
1323 rv = -1;
1324 break;
1325 default:
1326 log_print("invalid status for revert %d", lkb->lkb_status);
1327 }
1328 return rv;
1329 }
1330
1331 static int revert_lock_pc(struct dlm_rsb *r, struct dlm_lkb *lkb)
1332 {
1333 return revert_lock(r, lkb);
1334 }
1335
1336 static void _grant_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
1337 {
1338 if (lkb->lkb_grmode != lkb->lkb_rqmode) {
1339 lkb->lkb_grmode = lkb->lkb_rqmode;
1340 if (lkb->lkb_status)
1341 move_lkb(r, lkb, DLM_LKSTS_GRANTED);
1342 else
1343 add_lkb(r, lkb, DLM_LKSTS_GRANTED);
1344 }
1345
1346 lkb->lkb_rqmode = DLM_LOCK_IV;
1347 }
1348
1349 static void grant_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
1350 {
1351 set_lvb_lock(r, lkb);
1352 _grant_lock(r, lkb);
1353 lkb->lkb_highbast = 0;
1354 }
1355
1356 static void grant_lock_pc(struct dlm_rsb *r, struct dlm_lkb *lkb,
1357 struct dlm_message *ms)
1358 {
1359 set_lvb_lock_pc(r, lkb, ms);
1360 _grant_lock(r, lkb);
1361 }
1362
1363 /* called by grant_pending_locks() which means an async grant message must
1364 be sent to the requesting node in addition to granting the lock if the
1365 lkb belongs to a remote node. */
1366
1367 static void grant_lock_pending(struct dlm_rsb *r, struct dlm_lkb *lkb)
1368 {
1369 grant_lock(r, lkb);
1370 if (is_master_copy(lkb))
1371 send_grant(r, lkb);
1372 else
1373 queue_cast(r, lkb, 0);
1374 }
1375
1376 /* The special CONVDEADLK, ALTPR and ALTCW flags allow the master to
1377 change the granted/requested modes. We're munging things accordingly in
1378 the process copy.
1379 CONVDEADLK: our grmode may have been forced down to NL to resolve a
1380 conversion deadlock
1381 ALTPR/ALTCW: our rqmode may have been changed to PR or CW to become
1382 compatible with other granted locks */
1383
1384 static void munge_demoted(struct dlm_lkb *lkb, struct dlm_message *ms)
1385 {
1386 if (ms->m_type != DLM_MSG_CONVERT_REPLY) {
1387 log_print("munge_demoted %x invalid reply type %d",
1388 lkb->lkb_id, ms->m_type);
1389 return;
1390 }
1391
1392 if (lkb->lkb_rqmode == DLM_LOCK_IV || lkb->lkb_grmode == DLM_LOCK_IV) {
1393 log_print("munge_demoted %x invalid modes gr %d rq %d",
1394 lkb->lkb_id, lkb->lkb_grmode, lkb->lkb_rqmode);
1395 return;
1396 }
1397
1398 lkb->lkb_grmode = DLM_LOCK_NL;
1399 }
1400
1401 static void munge_altmode(struct dlm_lkb *lkb, struct dlm_message *ms)
1402 {
1403 if (ms->m_type != DLM_MSG_REQUEST_REPLY &&
1404 ms->m_type != DLM_MSG_GRANT) {
1405 log_print("munge_altmode %x invalid reply type %d",
1406 lkb->lkb_id, ms->m_type);
1407 return;
1408 }
1409
1410 if (lkb->lkb_exflags & DLM_LKF_ALTPR)
1411 lkb->lkb_rqmode = DLM_LOCK_PR;
1412 else if (lkb->lkb_exflags & DLM_LKF_ALTCW)
1413 lkb->lkb_rqmode = DLM_LOCK_CW;
1414 else {
1415 log_print("munge_altmode invalid exflags %x", lkb->lkb_exflags);
1416 dlm_print_lkb(lkb);
1417 }
1418 }
1419
1420 static inline int first_in_list(struct dlm_lkb *lkb, struct list_head *head)
1421 {
1422 struct dlm_lkb *first = list_entry(head->next, struct dlm_lkb,
1423 lkb_statequeue);
1424 if (lkb->lkb_id == first->lkb_id)
1425 return 1;
1426
1427 return 0;
1428 }
1429
1430 /* Check if the given lkb conflicts with another lkb on the queue. */
1431
1432 static int queue_conflict(struct list_head *head, struct dlm_lkb *lkb)
1433 {
1434 struct dlm_lkb *this;
1435
1436 list_for_each_entry(this, head, lkb_statequeue) {
1437 if (this == lkb)
1438 continue;
1439 if (!modes_compat(this, lkb))
1440 return 1;
1441 }
1442 return 0;
1443 }
1444
1445 /*
1446 * "A conversion deadlock arises with a pair of lock requests in the converting
1447 * queue for one resource. The granted mode of each lock blocks the requested
1448 * mode of the other lock."
1449 *
1450 * Part 2: if the granted mode of lkb is preventing an earlier lkb in the
1451 * convert queue from being granted, then deadlk/demote lkb.
1452 *
1453 * Example:
1454 * Granted Queue: empty
1455 * Convert Queue: NL->EX (first lock)
1456 * PR->EX (second lock)
1457 *
1458 * The first lock can't be granted because of the granted mode of the second
1459 * lock and the second lock can't be granted because it's not first in the
1460 * list. We either cancel lkb's conversion (PR->EX) and return EDEADLK, or we
1461 * demote the granted mode of lkb (from PR to NL) if it has the CONVDEADLK
1462 * flag set and return DEMOTED in the lksb flags.
1463 *
1464 * Originally, this function detected conv-deadlk in a more limited scope:
1465 * - if !modes_compat(lkb1, lkb2) && !modes_compat(lkb2, lkb1), or
1466 * - if lkb1 was the first entry in the queue (not just earlier), and was
1467 * blocked by the granted mode of lkb2, and there was nothing on the
1468 * granted queue preventing lkb1 from being granted immediately, i.e.
1469 * lkb2 was the only thing preventing lkb1 from being granted.
1470 *
1471 * That second condition meant we'd only say there was conv-deadlk if
1472 * resolving it (by demotion) would lead to the first lock on the convert
1473 * queue being granted right away. It allowed conversion deadlocks to exist
1474 * between locks on the convert queue while they couldn't be granted anyway.
1475 *
1476 * Now, we detect and take action on conversion deadlocks immediately when
1477 * they're created, even if they may not be immediately consequential. If
1478 * lkb1 exists anywhere in the convert queue and lkb2 comes in with a granted
1479 * mode that would prevent lkb1's conversion from being granted, we do a
1480 * deadlk/demote on lkb2 right away and don't let it onto the convert queue.
1481 * I think this means that the lkb_is_ahead condition below should always
1482 * be zero, i.e. there will never be conv-deadlk between two locks that are
1483 * both already on the convert queue.
1484 */
1485
1486 static int conversion_deadlock_detect(struct dlm_rsb *r, struct dlm_lkb *lkb2)
1487 {
1488 struct dlm_lkb *lkb1;
1489 int lkb_is_ahead = 0;
1490
1491 list_for_each_entry(lkb1, &r->res_convertqueue, lkb_statequeue) {
1492 if (lkb1 == lkb2) {
1493 lkb_is_ahead = 1;
1494 continue;
1495 }
1496
1497 if (!lkb_is_ahead) {
1498 if (!modes_compat(lkb2, lkb1))
1499 return 1;
1500 } else {
1501 if (!modes_compat(lkb2, lkb1) &&
1502 !modes_compat(lkb1, lkb2))
1503 return 1;
1504 }
1505 }
1506 return 0;
1507 }
1508
1509 /*
1510 * Return 1 if the lock can be granted, 0 otherwise.
1511 * Also detect and resolve conversion deadlocks.
1512 *
1513 * lkb is the lock to be granted
1514 *
1515 * now is 1 if the function is being called in the context of the
1516 * immediate request, it is 0 if called later, after the lock has been
1517 * queued.
1518 *
1519 * References are from chapter 6 of "VAXcluster Principles" by Roy Davis
1520 */
1521
1522 static int _can_be_granted(struct dlm_rsb *r, struct dlm_lkb *lkb, int now)
1523 {
1524 int8_t conv = (lkb->lkb_grmode != DLM_LOCK_IV);
1525
1526 /*
1527 * 6-10: Version 5.4 introduced an option to address the phenomenon of
1528 * a new request for a NL mode lock being blocked.
1529 *
1530 * 6-11: If the optional EXPEDITE flag is used with the new NL mode
1531 * request, then it would be granted. In essence, the use of this flag
1532 * tells the Lock Manager to expedite theis request by not considering
1533 * what may be in the CONVERTING or WAITING queues... As of this
1534 * writing, the EXPEDITE flag can be used only with new requests for NL
1535 * mode locks. This flag is not valid for conversion requests.
1536 *
1537 * A shortcut. Earlier checks return an error if EXPEDITE is used in a
1538 * conversion or used with a non-NL requested mode. We also know an
1539 * EXPEDITE request is always granted immediately, so now must always
1540 * be 1. The full condition to grant an expedite request: (now &&
1541 * !conv && lkb->rqmode == DLM_LOCK_NL && (flags & EXPEDITE)) can
1542 * therefore be shortened to just checking the flag.
1543 */
1544
1545 if (lkb->lkb_exflags & DLM_LKF_EXPEDITE)
1546 return 1;
1547
1548 /*
1549 * A shortcut. Without this, !queue_conflict(grantqueue, lkb) would be
1550 * added to the remaining conditions.
1551 */
1552
1553 if (queue_conflict(&r->res_grantqueue, lkb))
1554 goto out;
1555
1556 /*
1557 * 6-3: By default, a conversion request is immediately granted if the
1558 * requested mode is compatible with the modes of all other granted
1559 * locks
1560 */
1561
1562 if (queue_conflict(&r->res_convertqueue, lkb))
1563 goto out;
1564
1565 /*
1566 * 6-5: But the default algorithm for deciding whether to grant or
1567 * queue conversion requests does not by itself guarantee that such
1568 * requests are serviced on a "first come first serve" basis. This, in
1569 * turn, can lead to a phenomenon known as "indefinate postponement".
1570 *
1571 * 6-7: This issue is dealt with by using the optional QUECVT flag with
1572 * the system service employed to request a lock conversion. This flag
1573 * forces certain conversion requests to be queued, even if they are
1574 * compatible with the granted modes of other locks on the same
1575 * resource. Thus, the use of this flag results in conversion requests
1576 * being ordered on a "first come first servce" basis.
1577 *
1578 * DCT: This condition is all about new conversions being able to occur
1579 * "in place" while the lock remains on the granted queue (assuming
1580 * nothing else conflicts.) IOW if QUECVT isn't set, a conversion
1581 * doesn't _have_ to go onto the convert queue where it's processed in
1582 * order. The "now" variable is necessary to distinguish converts
1583 * being received and processed for the first time now, because once a
1584 * convert is moved to the conversion queue the condition below applies
1585 * requiring fifo granting.
1586 */
1587
1588 if (now && conv && !(lkb->lkb_exflags & DLM_LKF_QUECVT))
1589 return 1;
1590
1591 /*
1592 * The NOORDER flag is set to avoid the standard vms rules on grant
1593 * order.
1594 */
1595
1596 if (lkb->lkb_exflags & DLM_LKF_NOORDER)
1597 return 1;
1598
1599 /*
1600 * 6-3: Once in that queue [CONVERTING], a conversion request cannot be
1601 * granted until all other conversion requests ahead of it are granted
1602 * and/or canceled.
1603 */
1604
1605 if (!now && conv && first_in_list(lkb, &r->res_convertqueue))
1606 return 1;
1607
1608 /*
1609 * 6-4: By default, a new request is immediately granted only if all
1610 * three of the following conditions are satisfied when the request is
1611 * issued:
1612 * - The queue of ungranted conversion requests for the resource is
1613 * empty.
1614 * - The queue of ungranted new requests for the resource is empty.
1615 * - The mode of the new request is compatible with the most
1616 * restrictive mode of all granted locks on the resource.
1617 */
1618
1619 if (now && !conv && list_empty(&r->res_convertqueue) &&
1620 list_empty(&r->res_waitqueue))
1621 return 1;
1622
1623 /*
1624 * 6-4: Once a lock request is in the queue of ungranted new requests,
1625 * it cannot be granted until the queue of ungranted conversion
1626 * requests is empty, all ungranted new requests ahead of it are
1627 * granted and/or canceled, and it is compatible with the granted mode
1628 * of the most restrictive lock granted on the resource.
1629 */
1630
1631 if (!now && !conv && list_empty(&r->res_convertqueue) &&
1632 first_in_list(lkb, &r->res_waitqueue))
1633 return 1;
1634 out:
1635 return 0;
1636 }
1637
1638 static int can_be_granted(struct dlm_rsb *r, struct dlm_lkb *lkb, int now,
1639 int *err)
1640 {
1641 int rv;
1642 int8_t alt = 0, rqmode = lkb->lkb_rqmode;
1643 int8_t is_convert = (lkb->lkb_grmode != DLM_LOCK_IV);
1644
1645 if (err)
1646 *err = 0;
1647
1648 rv = _can_be_granted(r, lkb, now);
1649 if (rv)
1650 goto out;
1651
1652 /*
1653 * The CONVDEADLK flag is non-standard and tells the dlm to resolve
1654 * conversion deadlocks by demoting grmode to NL, otherwise the dlm
1655 * cancels one of the locks.
1656 */
1657
1658 if (is_convert && can_be_queued(lkb) &&
1659 conversion_deadlock_detect(r, lkb)) {
1660 if (lkb->lkb_exflags & DLM_LKF_CONVDEADLK) {
1661 lkb->lkb_grmode = DLM_LOCK_NL;
1662 lkb->lkb_sbflags |= DLM_SBF_DEMOTED;
1663 } else if (!(lkb->lkb_exflags & DLM_LKF_NODLCKWT)) {
1664 if (err)
1665 *err = -EDEADLK;
1666 else {
1667 log_print("can_be_granted deadlock %x now %d",
1668 lkb->lkb_id, now);
1669 dlm_dump_rsb(r);
1670 }
1671 }
1672 goto out;
1673 }
1674
1675 /*
1676 * The ALTPR and ALTCW flags are non-standard and tell the dlm to try
1677 * to grant a request in a mode other than the normal rqmode. It's a
1678 * simple way to provide a big optimization to applications that can
1679 * use them.
1680 */
1681
1682 if (rqmode != DLM_LOCK_PR && (lkb->lkb_exflags & DLM_LKF_ALTPR))
1683 alt = DLM_LOCK_PR;
1684 else if (rqmode != DLM_LOCK_CW && (lkb->lkb_exflags & DLM_LKF_ALTCW))
1685 alt = DLM_LOCK_CW;
1686
1687 if (alt) {
1688 lkb->lkb_rqmode = alt;
1689 rv = _can_be_granted(r, lkb, now);
1690 if (rv)
1691 lkb->lkb_sbflags |= DLM_SBF_ALTMODE;
1692 else
1693 lkb->lkb_rqmode = rqmode;
1694 }
1695 out:
1696 return rv;
1697 }
1698
1699 /* FIXME: I don't think that can_be_granted() can/will demote or find deadlock
1700 for locks pending on the convert list. Once verified (watch for these
1701 log_prints), we should be able to just call _can_be_granted() and not
1702 bother with the demote/deadlk cases here (and there's no easy way to deal
1703 with a deadlk here, we'd have to generate something like grant_lock with
1704 the deadlk error.) */
1705
1706 /* Returns the highest requested mode of all blocked conversions; sets
1707 cw if there's a blocked conversion to DLM_LOCK_CW. */
1708
1709 static int grant_pending_convert(struct dlm_rsb *r, int high, int *cw)
1710 {
1711 struct dlm_lkb *lkb, *s;
1712 int hi, demoted, quit, grant_restart, demote_restart;
1713 int deadlk;
1714
1715 quit = 0;
1716 restart:
1717 grant_restart = 0;
1718 demote_restart = 0;
1719 hi = DLM_LOCK_IV;
1720
1721 list_for_each_entry_safe(lkb, s, &r->res_convertqueue, lkb_statequeue) {
1722 demoted = is_demoted(lkb);
1723 deadlk = 0;
1724
1725 if (can_be_granted(r, lkb, 0, &deadlk)) {
1726 grant_lock_pending(r, lkb);
1727 grant_restart = 1;
1728 continue;
1729 }
1730
1731 if (!demoted && is_demoted(lkb)) {
1732 log_print("WARN: pending demoted %x node %d %s",
1733 lkb->lkb_id, lkb->lkb_nodeid, r->res_name);
1734 demote_restart = 1;
1735 continue;
1736 }
1737
1738 if (deadlk) {
1739 log_print("WARN: pending deadlock %x node %d %s",
1740 lkb->lkb_id, lkb->lkb_nodeid, r->res_name);
1741 dlm_dump_rsb(r);
1742 continue;
1743 }
1744
1745 hi = max_t(int, lkb->lkb_rqmode, hi);
1746
1747 if (cw && lkb->lkb_rqmode == DLM_LOCK_CW)
1748 *cw = 1;
1749 }
1750
1751 if (grant_restart)
1752 goto restart;
1753 if (demote_restart && !quit) {
1754 quit = 1;
1755 goto restart;
1756 }
1757
1758 return max_t(int, high, hi);
1759 }
1760
1761 static int grant_pending_wait(struct dlm_rsb *r, int high, int *cw)
1762 {
1763 struct dlm_lkb *lkb, *s;
1764
1765 list_for_each_entry_safe(lkb, s, &r->res_waitqueue, lkb_statequeue) {
1766 if (can_be_granted(r, lkb, 0, NULL))
1767 grant_lock_pending(r, lkb);
1768 else {
1769 high = max_t(int, lkb->lkb_rqmode, high);
1770 if (lkb->lkb_rqmode == DLM_LOCK_CW)
1771 *cw = 1;
1772 }
1773 }
1774
1775 return high;
1776 }
1777
1778 /* cw of 1 means there's a lock with a rqmode of DLM_LOCK_CW that's blocked
1779 on either the convert or waiting queue.
1780 high is the largest rqmode of all locks blocked on the convert or
1781 waiting queue. */
1782
1783 static int lock_requires_bast(struct dlm_lkb *gr, int high, int cw)
1784 {
1785 if (gr->lkb_grmode == DLM_LOCK_PR && cw) {
1786 if (gr->lkb_highbast < DLM_LOCK_EX)
1787 return 1;
1788 return 0;
1789 }
1790
1791 if (gr->lkb_highbast < high &&
1792 !__dlm_compat_matrix[gr->lkb_grmode+1][high+1])
1793 return 1;
1794 return 0;
1795 }
1796
1797 static void grant_pending_locks(struct dlm_rsb *r)
1798 {
1799 struct dlm_lkb *lkb, *s;
1800 int high = DLM_LOCK_IV;
1801 int cw = 0;
1802
1803 DLM_ASSERT(is_master(r), dlm_dump_rsb(r););
1804
1805 high = grant_pending_convert(r, high, &cw);
1806 high = grant_pending_wait(r, high, &cw);
1807
1808 if (high == DLM_LOCK_IV)
1809 return;
1810
1811 /*
1812 * If there are locks left on the wait/convert queue then send blocking
1813 * ASTs to granted locks based on the largest requested mode (high)
1814 * found above.
1815 */
1816
1817 list_for_each_entry_safe(lkb, s, &r->res_grantqueue, lkb_statequeue) {
1818 if (lkb->lkb_bastfn && lock_requires_bast(lkb, high, cw)) {
1819 if (cw && high == DLM_LOCK_PR &&
1820 lkb->lkb_grmode == DLM_LOCK_PR)
1821 queue_bast(r, lkb, DLM_LOCK_CW);
1822 else
1823 queue_bast(r, lkb, high);
1824 lkb->lkb_highbast = high;
1825 }
1826 }
1827 }
1828
1829 static int modes_require_bast(struct dlm_lkb *gr, struct dlm_lkb *rq)
1830 {
1831 if ((gr->lkb_grmode == DLM_LOCK_PR && rq->lkb_rqmode == DLM_LOCK_CW) ||
1832 (gr->lkb_grmode == DLM_LOCK_CW && rq->lkb_rqmode == DLM_LOCK_PR)) {
1833 if (gr->lkb_highbast < DLM_LOCK_EX)
1834 return 1;
1835 return 0;
1836 }
1837
1838 if (gr->lkb_highbast < rq->lkb_rqmode && !modes_compat(gr, rq))
1839 return 1;
1840 return 0;
1841 }
1842
1843 static void send_bast_queue(struct dlm_rsb *r, struct list_head *head,
1844 struct dlm_lkb *lkb)
1845 {
1846 struct dlm_lkb *gr;
1847
1848 list_for_each_entry(gr, head, lkb_statequeue) {
1849 if (gr->lkb_bastfn && modes_require_bast(gr, lkb)) {
1850 queue_bast(r, gr, lkb->lkb_rqmode);
1851 gr->lkb_highbast = lkb->lkb_rqmode;
1852 }
1853 }
1854 }
1855
1856 static void send_blocking_asts(struct dlm_rsb *r, struct dlm_lkb *lkb)
1857 {
1858 send_bast_queue(r, &r->res_grantqueue, lkb);
1859 }
1860
1861 static void send_blocking_asts_all(struct dlm_rsb *r, struct dlm_lkb *lkb)
1862 {
1863 send_bast_queue(r, &r->res_grantqueue, lkb);
1864 send_bast_queue(r, &r->res_convertqueue, lkb);
1865 }
1866
1867 /* set_master(r, lkb) -- set the master nodeid of a resource
1868
1869 The purpose of this function is to set the nodeid field in the given
1870 lkb using the nodeid field in the given rsb. If the rsb's nodeid is
1871 known, it can just be copied to the lkb and the function will return
1872 0. If the rsb's nodeid is _not_ known, it needs to be looked up
1873 before it can be copied to the lkb.
1874
1875 When the rsb nodeid is being looked up remotely, the initial lkb
1876 causing the lookup is kept on the ls_waiters list waiting for the
1877 lookup reply. Other lkb's waiting for the same rsb lookup are kept
1878 on the rsb's res_lookup list until the master is verified.
1879
1880 Return values:
1881 0: nodeid is set in rsb/lkb and the caller should go ahead and use it
1882 1: the rsb master is not available and the lkb has been placed on
1883 a wait queue
1884 */
1885
1886 static int set_master(struct dlm_rsb *r, struct dlm_lkb *lkb)
1887 {
1888 struct dlm_ls *ls = r->res_ls;
1889 int i, error, dir_nodeid, ret_nodeid, our_nodeid = dlm_our_nodeid();
1890
1891 if (rsb_flag(r, RSB_MASTER_UNCERTAIN)) {
1892 rsb_clear_flag(r, RSB_MASTER_UNCERTAIN);
1893 r->res_first_lkid = lkb->lkb_id;
1894 lkb->lkb_nodeid = r->res_nodeid;
1895 return 0;
1896 }
1897
1898 if (r->res_first_lkid && r->res_first_lkid != lkb->lkb_id) {
1899 list_add_tail(&lkb->lkb_rsb_lookup, &r->res_lookup);
1900 return 1;
1901 }
1902
1903 if (r->res_nodeid == 0) {
1904 lkb->lkb_nodeid = 0;
1905 return 0;
1906 }
1907
1908 if (r->res_nodeid > 0) {
1909 lkb->lkb_nodeid = r->res_nodeid;
1910 return 0;
1911 }
1912
1913 DLM_ASSERT(r->res_nodeid == -1, dlm_dump_rsb(r););
1914
1915 dir_nodeid = dlm_dir_nodeid(r);
1916
1917 if (dir_nodeid != our_nodeid) {
1918 r->res_first_lkid = lkb->lkb_id;
1919 send_lookup(r, lkb);
1920 return 1;
1921 }
1922
1923 for (i = 0; i < 2; i++) {
1924 /* It's possible for dlm_scand to remove an old rsb for
1925 this same resource from the toss list, us to create
1926 a new one, look up the master locally, and find it
1927 already exists just before dlm_scand does the
1928 dir_remove() on the previous rsb. */
1929
1930 error = dlm_dir_lookup(ls, our_nodeid, r->res_name,
1931 r->res_length, &ret_nodeid);
1932 if (!error)
1933 break;
1934 log_debug(ls, "dir_lookup error %d %s", error, r->res_name);
1935 schedule();
1936 }
1937 if (error && error != -EEXIST)
1938 return error;
1939
1940 if (ret_nodeid == our_nodeid) {
1941 r->res_first_lkid = 0;
1942 r->res_nodeid = 0;
1943 lkb->lkb_nodeid = 0;
1944 } else {
1945 r->res_first_lkid = lkb->lkb_id;
1946 r->res_nodeid = ret_nodeid;
1947 lkb->lkb_nodeid = ret_nodeid;
1948 }
1949 return 0;
1950 }
1951
1952 static void process_lookup_list(struct dlm_rsb *r)
1953 {
1954 struct dlm_lkb *lkb, *safe;
1955
1956 list_for_each_entry_safe(lkb, safe, &r->res_lookup, lkb_rsb_lookup) {
1957 list_del_init(&lkb->lkb_rsb_lookup);
1958 _request_lock(r, lkb);
1959 schedule();
1960 }
1961 }
1962
1963 /* confirm_master -- confirm (or deny) an rsb's master nodeid */
1964
1965 static void confirm_master(struct dlm_rsb *r, int error)
1966 {
1967 struct dlm_lkb *lkb;
1968
1969 if (!r->res_first_lkid)
1970 return;
1971
1972 switch (error) {
1973 case 0:
1974 case -EINPROGRESS:
1975 r->res_first_lkid = 0;
1976 process_lookup_list(r);
1977 break;
1978
1979 case -EAGAIN:
1980 case -EBADR:
1981 case -ENOTBLK:
1982 /* the remote request failed and won't be retried (it was
1983 a NOQUEUE, or has been canceled/unlocked); make a waiting
1984 lkb the first_lkid */
1985
1986 r->res_first_lkid = 0;
1987
1988 if (!list_empty(&r->res_lookup)) {
1989 lkb = list_entry(r->res_lookup.next, struct dlm_lkb,
1990 lkb_rsb_lookup);
1991 list_del_init(&lkb->lkb_rsb_lookup);
1992 r->res_first_lkid = lkb->lkb_id;
1993 _request_lock(r, lkb);
1994 }
1995 break;
1996
1997 default:
1998 log_error(r->res_ls, "confirm_master unknown error %d", error);
1999 }
2000 }
2001
2002 static int set_lock_args(int mode, struct dlm_lksb *lksb, uint32_t flags,
2003 int namelen, unsigned long timeout_cs,
2004 void (*ast) (void *astparam),
2005 void *astparam,
2006 void (*bast) (void *astparam, int mode),
2007 struct dlm_args *args)
2008 {
2009 int rv = -EINVAL;
2010
2011 /* check for invalid arg usage */
2012
2013 if (mode < 0 || mode > DLM_LOCK_EX)
2014 goto out;
2015
2016 if (!(flags & DLM_LKF_CONVERT) && (namelen > DLM_RESNAME_MAXLEN))
2017 goto out;
2018
2019 if (flags & DLM_LKF_CANCEL)
2020 goto out;
2021
2022 if (flags & DLM_LKF_QUECVT && !(flags & DLM_LKF_CONVERT))
2023 goto out;
2024
2025 if (flags & DLM_LKF_CONVDEADLK && !(flags & DLM_LKF_CONVERT))
2026 goto out;
2027
2028 if (flags & DLM_LKF_CONVDEADLK && flags & DLM_LKF_NOQUEUE)
2029 goto out;
2030
2031 if (flags & DLM_LKF_EXPEDITE && flags & DLM_LKF_CONVERT)
2032 goto out;
2033
2034 if (flags & DLM_LKF_EXPEDITE && flags & DLM_LKF_QUECVT)
2035 goto out;
2036
2037 if (flags & DLM_LKF_EXPEDITE && flags & DLM_LKF_NOQUEUE)
2038 goto out;
2039
2040 if (flags & DLM_LKF_EXPEDITE && mode != DLM_LOCK_NL)
2041 goto out;
2042
2043 if (!ast || !lksb)
2044 goto out;
2045
2046 if (flags & DLM_LKF_VALBLK && !lksb->sb_lvbptr)
2047 goto out;
2048
2049 if (flags & DLM_LKF_CONVERT && !lksb->sb_lkid)
2050 goto out;
2051
2052 /* these args will be copied to the lkb in validate_lock_args,
2053 it cannot be done now because when converting locks, fields in
2054 an active lkb cannot be modified before locking the rsb */
2055
2056 args->flags = flags;
2057 args->astfn = ast;
2058 args->astparam = astparam;
2059 args->bastfn = bast;
2060 args->timeout = timeout_cs;
2061 args->mode = mode;
2062 args->lksb = lksb;
2063 rv = 0;
2064 out:
2065 return rv;
2066 }
2067
2068 static int set_unlock_args(uint32_t flags, void *astarg, struct dlm_args *args)
2069 {
2070 if (flags & ~(DLM_LKF_CANCEL | DLM_LKF_VALBLK | DLM_LKF_IVVALBLK |
2071 DLM_LKF_FORCEUNLOCK))
2072 return -EINVAL;
2073
2074 if (flags & DLM_LKF_CANCEL && flags & DLM_LKF_FORCEUNLOCK)
2075 return -EINVAL;
2076
2077 args->flags = flags;
2078 args->astparam = astarg;
2079 return 0;
2080 }
2081
2082 static int validate_lock_args(struct dlm_ls *ls, struct dlm_lkb *lkb,
2083 struct dlm_args *args)
2084 {
2085 int rv = -EINVAL;
2086
2087 if (args->flags & DLM_LKF_CONVERT) {
2088 if (lkb->lkb_flags & DLM_IFL_MSTCPY)
2089 goto out;
2090
2091 if (args->flags & DLM_LKF_QUECVT &&
2092 !__quecvt_compat_matrix[lkb->lkb_grmode+1][args->mode+1])
2093 goto out;
2094
2095 rv = -EBUSY;
2096 if (lkb->lkb_status != DLM_LKSTS_GRANTED)
2097 goto out;
2098
2099 if (lkb->lkb_wait_type)
2100 goto out;
2101
2102 if (is_overlap(lkb))
2103 goto out;
2104 }
2105
2106 lkb->lkb_exflags = args->flags;
2107 lkb->lkb_sbflags = 0;
2108 lkb->lkb_astfn = args->astfn;
2109 lkb->lkb_astparam = args->astparam;
2110 lkb->lkb_bastfn = args->bastfn;
2111 lkb->lkb_rqmode = args->mode;
2112 lkb->lkb_lksb = args->lksb;
2113 lkb->lkb_lvbptr = args->lksb->sb_lvbptr;
2114 lkb->lkb_ownpid = (int) current->pid;
2115 lkb->lkb_timeout_cs = args->timeout;
2116 rv = 0;
2117 out:
2118 if (rv)
2119 log_debug(ls, "validate_lock_args %d %x %x %x %d %d %s",
2120 rv, lkb->lkb_id, lkb->lkb_flags, args->flags,
2121 lkb->lkb_status, lkb->lkb_wait_type,
2122 lkb->lkb_resource->res_name);
2123 return rv;
2124 }
2125
2126 /* when dlm_unlock() sees -EBUSY with CANCEL/FORCEUNLOCK it returns 0
2127 for success */
2128
2129 /* note: it's valid for lkb_nodeid/res_nodeid to be -1 when we get here
2130 because there may be a lookup in progress and it's valid to do
2131 cancel/unlockf on it */
2132
2133 static int validate_unlock_args(struct dlm_lkb *lkb, struct dlm_args *args)
2134 {
2135 struct dlm_ls *ls = lkb->lkb_resource->res_ls;
2136 int rv = -EINVAL;
2137
2138 if (lkb->lkb_flags & DLM_IFL_MSTCPY) {
2139 log_error(ls, "unlock on MSTCPY %x", lkb->lkb_id);
2140 dlm_print_lkb(lkb);
2141 goto out;
2142 }
2143
2144 /* an lkb may still exist even though the lock is EOL'ed due to a
2145 cancel, unlock or failed noqueue request; an app can't use these
2146 locks; return same error as if the lkid had not been found at all */
2147
2148 if (lkb->lkb_flags & DLM_IFL_ENDOFLIFE) {
2149 log_debug(ls, "unlock on ENDOFLIFE %x", lkb->lkb_id);
2150 rv = -ENOENT;
2151 goto out;
2152 }
2153
2154 /* an lkb may be waiting for an rsb lookup to complete where the
2155 lookup was initiated by another lock */
2156
2157 if (!list_empty(&lkb->lkb_rsb_lookup)) {
2158 if (args->flags & (DLM_LKF_CANCEL | DLM_LKF_FORCEUNLOCK)) {
2159 log_debug(ls, "unlock on rsb_lookup %x", lkb->lkb_id);
2160 list_del_init(&lkb->lkb_rsb_lookup);
2161 queue_cast(lkb->lkb_resource, lkb,
2162 args->flags & DLM_LKF_CANCEL ?
2163 -DLM_ECANCEL : -DLM_EUNLOCK);
2164 unhold_lkb(lkb); /* undoes create_lkb() */
2165 }
2166 /* caller changes -EBUSY to 0 for CANCEL and FORCEUNLOCK */
2167 rv = -EBUSY;
2168 goto out;
2169 }
2170
2171 /* cancel not allowed with another cancel/unlock in progress */
2172
2173 if (args->flags & DLM_LKF_CANCEL) {
2174 if (lkb->lkb_exflags & DLM_LKF_CANCEL)
2175 goto out;
2176
2177 if (is_overlap(lkb))
2178 goto out;
2179
2180 /* don't let scand try to do a cancel */
2181 del_timeout(lkb);
2182
2183 if (lkb->lkb_flags & DLM_IFL_RESEND) {
2184 lkb->lkb_flags |= DLM_IFL_OVERLAP_CANCEL;
2185 rv = -EBUSY;
2186 goto out;
2187 }
2188
2189 /* there's nothing to cancel */
2190 if (lkb->lkb_status == DLM_LKSTS_GRANTED &&
2191 !lkb->lkb_wait_type) {
2192 rv = -EBUSY;
2193 goto out;
2194 }
2195
2196 switch (lkb->lkb_wait_type) {
2197 case DLM_MSG_LOOKUP:
2198 case DLM_MSG_REQUEST:
2199 lkb->lkb_flags |= DLM_IFL_OVERLAP_CANCEL;
2200 rv = -EBUSY;
2201 goto out;
2202 case DLM_MSG_UNLOCK:
2203 case DLM_MSG_CANCEL:
2204 goto out;
2205 }
2206 /* add_to_waiters() will set OVERLAP_CANCEL */
2207 goto out_ok;
2208 }
2209
2210 /* do we need to allow a force-unlock if there's a normal unlock
2211 already in progress? in what conditions could the normal unlock
2212 fail such that we'd want to send a force-unlock to be sure? */
2213
2214 if (args->flags & DLM_LKF_FORCEUNLOCK) {
2215 if (lkb->lkb_exflags & DLM_LKF_FORCEUNLOCK)
2216 goto out;
2217
2218 if (is_overlap_unlock(lkb))
2219 goto out;
2220
2221 /* don't let scand try to do a cancel */
2222 del_timeout(lkb);
2223
2224 if (lkb->lkb_flags & DLM_IFL_RESEND) {
2225 lkb->lkb_flags |= DLM_IFL_OVERLAP_UNLOCK;
2226 rv = -EBUSY;
2227 goto out;
2228 }
2229
2230 switch (lkb->lkb_wait_type) {
2231 case DLM_MSG_LOOKUP:
2232 case DLM_MSG_REQUEST:
2233 lkb->lkb_flags |= DLM_IFL_OVERLAP_UNLOCK;
2234 rv = -EBUSY;
2235 goto out;
2236 case DLM_MSG_UNLOCK:
2237 goto out;
2238 }
2239 /* add_to_waiters() will set OVERLAP_UNLOCK */
2240 goto out_ok;
2241 }
2242
2243 /* normal unlock not allowed if there's any op in progress */
2244 rv = -EBUSY;
2245 if (lkb->lkb_wait_type || lkb->lkb_wait_count)
2246 goto out;
2247
2248 out_ok:
2249 /* an overlapping op shouldn't blow away exflags from other op */
2250 lkb->lkb_exflags |= args->flags;
2251 lkb->lkb_sbflags = 0;
2252 lkb->lkb_astparam = args->astparam;
2253 rv = 0;
2254 out:
2255 if (rv)
2256 log_debug(ls, "validate_unlock_args %d %x %x %x %x %d %s", rv,
2257 lkb->lkb_id, lkb->lkb_flags, lkb->lkb_exflags,
2258 args->flags, lkb->lkb_wait_type,
2259 lkb->lkb_resource->res_name);
2260 return rv;
2261 }
2262
2263 /*
2264 * Four stage 4 varieties:
2265 * do_request(), do_convert(), do_unlock(), do_cancel()
2266 * These are called on the master node for the given lock and
2267 * from the central locking logic.
2268 */
2269
2270 static int do_request(struct dlm_rsb *r, struct dlm_lkb *lkb)
2271 {
2272 int error = 0;
2273
2274 if (can_be_granted(r, lkb, 1, NULL)) {
2275 grant_lock(r, lkb);
2276 queue_cast(r, lkb, 0);
2277 goto out;
2278 }
2279
2280 if (can_be_queued(lkb)) {
2281 error = -EINPROGRESS;
2282 add_lkb(r, lkb, DLM_LKSTS_WAITING);
2283 send_blocking_asts(r, lkb);
2284 add_timeout(lkb);
2285 goto out;
2286 }
2287
2288 error = -EAGAIN;
2289 if (force_blocking_asts(lkb))
2290 send_blocking_asts_all(r, lkb);
2291 queue_cast(r, lkb, -EAGAIN);
2292
2293 out:
2294 return error;
2295 }
2296
2297 static int do_convert(struct dlm_rsb *r, struct dlm_lkb *lkb)
2298 {
2299 int error = 0;
2300 int deadlk = 0;
2301
2302 /* changing an existing lock may allow others to be granted */
2303
2304 if (can_be_granted(r, lkb, 1, &deadlk)) {
2305 grant_lock(r, lkb);
2306 queue_cast(r, lkb, 0);
2307 grant_pending_locks(r);
2308 goto out;
2309 }
2310
2311 /* can_be_granted() detected that this lock would block in a conversion
2312 deadlock, so we leave it on the granted queue and return EDEADLK in
2313 the ast for the convert. */
2314
2315 if (deadlk) {
2316 /* it's left on the granted queue */
2317 log_debug(r->res_ls, "deadlock %x node %d sts%d g%d r%d %s",
2318 lkb->lkb_id, lkb->lkb_nodeid, lkb->lkb_status,
2319 lkb->lkb_grmode, lkb->lkb_rqmode, r->res_name);
2320 revert_lock(r, lkb);
2321 queue_cast(r, lkb, -EDEADLK);
2322 error = -EDEADLK;
2323 goto out;
2324 }
2325
2326 /* is_demoted() means the can_be_granted() above set the grmode
2327 to NL, and left us on the granted queue. This auto-demotion
2328 (due to CONVDEADLK) might mean other locks, and/or this lock, are
2329 now grantable. We have to try to grant other converting locks
2330 before we try again to grant this one. */
2331
2332 if (is_demoted(lkb)) {
2333 grant_pending_convert(r, DLM_LOCK_IV, NULL);
2334 if (_can_be_granted(r, lkb, 1)) {
2335 grant_lock(r, lkb);
2336 queue_cast(r, lkb, 0);
2337 grant_pending_locks(r);
2338 goto out;
2339 }
2340 /* else fall through and move to convert queue */
2341 }
2342
2343 if (can_be_queued(lkb)) {
2344 error = -EINPROGRESS;
2345 del_lkb(r, lkb);
2346 add_lkb(r, lkb, DLM_LKSTS_CONVERT);
2347 send_blocking_asts(r, lkb);
2348 add_timeout(lkb);
2349 goto out;
2350 }
2351
2352 error = -EAGAIN;
2353 if (force_blocking_asts(lkb))
2354 send_blocking_asts_all(r, lkb);
2355 queue_cast(r, lkb, -EAGAIN);
2356
2357 out:
2358 return error;
2359 }
2360
2361 static int do_unlock(struct dlm_rsb *r, struct dlm_lkb *lkb)
2362 {
2363 remove_lock(r, lkb);
2364 queue_cast(r, lkb, -DLM_EUNLOCK);
2365 grant_pending_locks(r);
2366 return -DLM_EUNLOCK;
2367 }
2368
2369 /* returns: 0 did nothing, -DLM_ECANCEL canceled lock */
2370
2371 static int do_cancel(struct dlm_rsb *r, struct dlm_lkb *lkb)
2372 {
2373 int error;
2374
2375 error = revert_lock(r, lkb);
2376 if (error) {
2377 queue_cast(r, lkb, -DLM_ECANCEL);
2378 grant_pending_locks(r);
2379 return -DLM_ECANCEL;
2380 }
2381 return 0;
2382 }
2383
2384 /*
2385 * Four stage 3 varieties:
2386 * _request_lock(), _convert_lock(), _unlock_lock(), _cancel_lock()
2387 */
2388
2389 /* add a new lkb to a possibly new rsb, called by requesting process */
2390
2391 static int _request_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
2392 {
2393 int error;
2394
2395 /* set_master: sets lkb nodeid from r */
2396
2397 error = set_master(r, lkb);
2398 if (error < 0)
2399 goto out;
2400 if (error) {
2401 error = 0;
2402 goto out;
2403 }
2404
2405 if (is_remote(r))
2406 /* receive_request() calls do_request() on remote node */
2407 error = send_request(r, lkb);
2408 else
2409 error = do_request(r, lkb);
2410 out:
2411 return error;
2412 }
2413
2414 /* change some property of an existing lkb, e.g. mode */
2415
2416 static int _convert_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
2417 {
2418 int error;
2419
2420 if (is_remote(r))
2421 /* receive_convert() calls do_convert() on remote node */
2422 error = send_convert(r, lkb);
2423 else
2424 error = do_convert(r, lkb);
2425
2426 return error;
2427 }
2428
2429 /* remove an existing lkb from the granted queue */
2430
2431 static int _unlock_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
2432 {
2433 int error;
2434
2435 if (is_remote(r))
2436 /* receive_unlock() calls do_unlock() on remote node */
2437 error = send_unlock(r, lkb);
2438 else
2439 error = do_unlock(r, lkb);
2440
2441 return error;
2442 }
2443
2444 /* remove an existing lkb from the convert or wait queue */
2445
2446 static int _cancel_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
2447 {
2448 int error;
2449
2450 if (is_remote(r))
2451 /* receive_cancel() calls do_cancel() on remote node */
2452 error = send_cancel(r, lkb);
2453 else
2454 error = do_cancel(r, lkb);
2455
2456 return error;
2457 }
2458
2459 /*
2460 * Four stage 2 varieties:
2461 * request_lock(), convert_lock(), unlock_lock(), cancel_lock()
2462 */
2463
2464 static int request_lock(struct dlm_ls *ls, struct dlm_lkb *lkb, char *name,
2465 int len, struct dlm_args *args)
2466 {
2467 struct dlm_rsb *r;
2468 int error;
2469
2470 error = validate_lock_args(ls, lkb, args);
2471 if (error)
2472 goto out;
2473
2474 error = find_rsb(ls, name, len, R_CREATE, &r);
2475 if (error)
2476 goto out;
2477
2478 lock_rsb(r);
2479
2480 attach_lkb(r, lkb);
2481 lkb->lkb_lksb->sb_lkid = lkb->lkb_id;
2482
2483 error = _request_lock(r, lkb);
2484
2485 unlock_rsb(r);
2486 put_rsb(r);
2487
2488 out:
2489 return error;
2490 }
2491
2492 static int convert_lock(struct dlm_ls *ls, struct dlm_lkb *lkb,
2493 struct dlm_args *args)
2494 {
2495 struct dlm_rsb *r;
2496 int error;
2497
2498 r = lkb->lkb_resource;
2499
2500 hold_rsb(r);
2501 lock_rsb(r);
2502
2503 error = validate_lock_args(ls, lkb, args);
2504 if (error)
2505 goto out;
2506
2507 error = _convert_lock(r, lkb);
2508 out:
2509 unlock_rsb(r);
2510 put_rsb(r);
2511 return error;
2512 }
2513
2514 static int unlock_lock(struct dlm_ls *ls, struct dlm_lkb *lkb,
2515 struct dlm_args *args)
2516 {
2517 struct dlm_rsb *r;
2518 int error;
2519
2520 r = lkb->lkb_resource;
2521
2522 hold_rsb(r);
2523 lock_rsb(r);
2524
2525 error = validate_unlock_args(lkb, args);
2526 if (error)
2527 goto out;
2528
2529 error = _unlock_lock(r, lkb);
2530 out:
2531 unlock_rsb(r);
2532 put_rsb(r);
2533 return error;
2534 }
2535
2536 static int cancel_lock(struct dlm_ls *ls, struct dlm_lkb *lkb,
2537 struct dlm_args *args)
2538 {
2539 struct dlm_rsb *r;
2540 int error;
2541
2542 r = lkb->lkb_resource;
2543
2544 hold_rsb(r);
2545 lock_rsb(r);
2546
2547 error = validate_unlock_args(lkb, args);
2548 if (error)
2549 goto out;
2550
2551 error = _cancel_lock(r, lkb);
2552 out:
2553 unlock_rsb(r);
2554 put_rsb(r);
2555 return error;
2556 }
2557
2558 /*
2559 * Two stage 1 varieties: dlm_lock() and dlm_unlock()
2560 */
2561
2562 int dlm_lock(dlm_lockspace_t *lockspace,
2563 int mode,
2564 struct dlm_lksb *lksb,
2565 uint32_t flags,
2566 void *name,
2567 unsigned int namelen,
2568 uint32_t parent_lkid,
2569 void (*ast) (void *astarg),
2570 void *astarg,
2571 void (*bast) (void *astarg, int mode))
2572 {
2573 struct dlm_ls *ls;
2574 struct dlm_lkb *lkb;
2575 struct dlm_args args;
2576 int error, convert = flags & DLM_LKF_CONVERT;
2577
2578 ls = dlm_find_lockspace_local(lockspace);
2579 if (!ls)
2580 return -EINVAL;
2581
2582 dlm_lock_recovery(ls);
2583
2584 if (convert)
2585 error = find_lkb(ls, lksb->sb_lkid, &lkb);
2586 else
2587 error = create_lkb(ls, &lkb);
2588
2589 if (error)
2590 goto out;
2591
2592 error = set_lock_args(mode, lksb, flags, namelen, 0, ast,
2593 astarg, bast, &args);
2594 if (error)
2595 goto out_put;
2596
2597 if (convert)
2598 error = convert_lock(ls, lkb, &args);
2599 else
2600 error = request_lock(ls, lkb, name, namelen, &args);
2601
2602 if (error == -EINPROGRESS)
2603 error = 0;
2604 out_put:
2605 if (convert || error)
2606 __put_lkb(ls, lkb);
2607 if (error == -EAGAIN || error == -EDEADLK)
2608 error = 0;
2609 out:
2610 dlm_unlock_recovery(ls);
2611 dlm_put_lockspace(ls);
2612 return error;
2613 }
2614
2615 int dlm_unlock(dlm_lockspace_t *lockspace,
2616 uint32_t lkid,
2617 uint32_t flags,
2618 struct dlm_lksb *lksb,
2619 void *astarg)
2620 {
2621 struct dlm_ls *ls;
2622 struct dlm_lkb *lkb;
2623 struct dlm_args args;
2624 int error;
2625
2626 ls = dlm_find_lockspace_local(lockspace);
2627 if (!ls)
2628 return -EINVAL;
2629
2630 dlm_lock_recovery(ls);
2631
2632 error = find_lkb(ls, lkid, &lkb);
2633 if (error)
2634 goto out;
2635
2636 error = set_unlock_args(flags, astarg, &args);
2637 if (error)
2638 goto out_put;
2639
2640 if (flags & DLM_LKF_CANCEL)
2641 error = cancel_lock(ls, lkb, &args);
2642 else
2643 error = unlock_lock(ls, lkb, &args);
2644
2645 if (error == -DLM_EUNLOCK || error == -DLM_ECANCEL)
2646 error = 0;
2647 if (error == -EBUSY && (flags & (DLM_LKF_CANCEL | DLM_LKF_FORCEUNLOCK)))
2648 error = 0;
2649 out_put:
2650 dlm_put_lkb(lkb);
2651 out:
2652 dlm_unlock_recovery(ls);
2653 dlm_put_lockspace(ls);
2654 return error;
2655 }
2656
2657 /*
2658 * send/receive routines for remote operations and replies
2659 *
2660 * send_args
2661 * send_common
2662 * send_request receive_request
2663 * send_convert receive_convert
2664 * send_unlock receive_unlock
2665 * send_cancel receive_cancel
2666 * send_grant receive_grant
2667 * send_bast receive_bast
2668 * send_lookup receive_lookup
2669 * send_remove receive_remove
2670 *
2671 * send_common_reply
2672 * receive_request_reply send_request_reply
2673 * receive_convert_reply send_convert_reply
2674 * receive_unlock_reply send_unlock_reply
2675 * receive_cancel_reply send_cancel_reply
2676 * receive_lookup_reply send_lookup_reply
2677 */
2678
2679 static int _create_message(struct dlm_ls *ls, int mb_len,
2680 int to_nodeid, int mstype,
2681 struct dlm_message **ms_ret,
2682 struct dlm_mhandle **mh_ret)
2683 {
2684 struct dlm_message *ms;
2685 struct dlm_mhandle *mh;
2686 char *mb;
2687
2688 /* get_buffer gives us a message handle (mh) that we need to
2689 pass into lowcomms_commit and a message buffer (mb) that we
2690 write our data into */
2691
2692 mh = dlm_lowcomms_get_buffer(to_nodeid, mb_len, ls->ls_allocation, &mb);
2693 if (!mh)
2694 return -ENOBUFS;
2695
2696 memset(mb, 0, mb_len);
2697
2698 ms = (struct dlm_message *) mb;
2699
2700 ms->m_header.h_version = (DLM_HEADER_MAJOR | DLM_HEADER_MINOR);
2701 ms->m_header.h_lockspace = ls->ls_global_id;
2702 ms->m_header.h_nodeid = dlm_our_nodeid();
2703 ms->m_header.h_length = mb_len;
2704 ms->m_header.h_cmd = DLM_MSG;
2705
2706 ms->m_type = mstype;
2707
2708 *mh_ret = mh;
2709 *ms_ret = ms;
2710 return 0;
2711 }
2712
2713 static int create_message(struct dlm_rsb *r, struct dlm_lkb *lkb,
2714 int to_nodeid, int mstype,
2715 struct dlm_message **ms_ret,
2716 struct dlm_mhandle **mh_ret)
2717 {
2718 int mb_len = sizeof(struct dlm_message);
2719
2720 switch (mstype) {
2721 case DLM_MSG_REQUEST:
2722 case DLM_MSG_LOOKUP:
2723 case DLM_MSG_REMOVE:
2724 mb_len += r->res_length;
2725 break;
2726 case DLM_MSG_CONVERT:
2727 case DLM_MSG_UNLOCK:
2728 case DLM_MSG_REQUEST_REPLY:
2729 case DLM_MSG_CONVERT_REPLY:
2730 case DLM_MSG_GRANT:
2731 if (lkb && lkb->lkb_lvbptr)
2732 mb_len += r->res_ls->ls_lvblen;
2733 break;
2734 }
2735
2736 return _create_message(r->res_ls, mb_len, to_nodeid, mstype,
2737 ms_ret, mh_ret);
2738 }
2739
2740 /* further lowcomms enhancements or alternate implementations may make
2741 the return value from this function useful at some point */
2742
2743 static int send_message(struct dlm_mhandle *mh, struct dlm_message *ms)
2744 {
2745 dlm_message_out(ms);
2746 dlm_lowcomms_commit_buffer(mh);
2747 return 0;
2748 }
2749
2750 static void send_args(struct dlm_rsb *r, struct dlm_lkb *lkb,
2751 struct dlm_message *ms)
2752 {
2753 ms->m_nodeid = lkb->lkb_nodeid;
2754 ms->m_pid = lkb->lkb_ownpid;
2755 ms->m_lkid = lkb->lkb_id;
2756 ms->m_remid = lkb->lkb_remid;
2757 ms->m_exflags = lkb->lkb_exflags;
2758 ms->m_sbflags = lkb->lkb_sbflags;
2759 ms->m_flags = lkb->lkb_flags;
2760 ms->m_lvbseq = lkb->lkb_lvbseq;
2761 ms->m_status = lkb->lkb_status;
2762 ms->m_grmode = lkb->lkb_grmode;
2763 ms->m_rqmode = lkb->lkb_rqmode;
2764 ms->m_hash = r->res_hash;
2765
2766 /* m_result and m_bastmode are set from function args,
2767 not from lkb fields */
2768
2769 if (lkb->lkb_bastfn)
2770 ms->m_asts |= AST_BAST;
2771 if (lkb->lkb_astfn)
2772 ms->m_asts |= AST_COMP;
2773
2774 /* compare with switch in create_message; send_remove() doesn't
2775 use send_args() */
2776
2777 switch (ms->m_type) {
2778 case DLM_MSG_REQUEST:
2779 case DLM_MSG_LOOKUP:
2780 memcpy(ms->m_extra, r->res_name, r->res_length);
2781 break;
2782 case DLM_MSG_CONVERT:
2783 case DLM_MSG_UNLOCK:
2784 case DLM_MSG_REQUEST_REPLY:
2785 case DLM_MSG_CONVERT_REPLY:
2786 case DLM_MSG_GRANT:
2787 if (!lkb->lkb_lvbptr)
2788 break;
2789 memcpy(ms->m_extra, lkb->lkb_lvbptr, r->res_ls->ls_lvblen);
2790 break;
2791 }
2792 }
2793
2794 static int send_common(struct dlm_rsb *r, struct dlm_lkb *lkb, int mstype)
2795 {
2796 struct dlm_message *ms;
2797 struct dlm_mhandle *mh;
2798 int to_nodeid, error;
2799
2800 error = add_to_waiters(lkb, mstype);
2801 if (error)
2802 return error;
2803
2804 to_nodeid = r->res_nodeid;
2805
2806 error = create_message(r, lkb, to_nodeid, mstype, &ms, &mh);
2807 if (error)
2808 goto fail;
2809
2810 send_args(r, lkb, ms);
2811
2812 error = send_message(mh, ms);
2813 if (error)
2814 goto fail;
2815 return 0;
2816
2817 fail:
2818 remove_from_waiters(lkb, msg_reply_type(mstype));
2819 return error;
2820 }
2821
2822 static int send_request(struct dlm_rsb *r, struct dlm_lkb *lkb)
2823 {
2824 return send_common(r, lkb, DLM_MSG_REQUEST);
2825 }
2826
2827 static int send_convert(struct dlm_rsb *r, struct dlm_lkb *lkb)
2828 {
2829 int error;
2830
2831 error = send_common(r, lkb, DLM_MSG_CONVERT);
2832
2833 /* down conversions go without a reply from the master */
2834 if (!error && down_conversion(lkb)) {
2835 remove_from_waiters(lkb, DLM_MSG_CONVERT_REPLY);
2836 r->res_ls->ls_stub_ms.m_type = DLM_MSG_CONVERT_REPLY;
2837 r->res_ls->ls_stub_ms.m_result = 0;
2838 r->res_ls->ls_stub_ms.m_flags = lkb->lkb_flags;
2839 __receive_convert_reply(r, lkb, &r->res_ls->ls_stub_ms);
2840 }
2841
2842 return error;
2843 }
2844
2845 /* FIXME: if this lkb is the only lock we hold on the rsb, then set
2846 MASTER_UNCERTAIN to force the next request on the rsb to confirm
2847 that the master is still correct. */
2848
2849 static int send_unlock(struct dlm_rsb *r, struct dlm_lkb *lkb)
2850 {
2851 return send_common(r, lkb, DLM_MSG_UNLOCK);
2852 }
2853
2854 static int send_cancel(struct dlm_rsb *r, struct dlm_lkb *lkb)
2855 {
2856 return send_common(r, lkb, DLM_MSG_CANCEL);
2857 }
2858
2859 static int send_grant(struct dlm_rsb *r, struct dlm_lkb *lkb)
2860 {
2861 struct dlm_message *ms;
2862 struct dlm_mhandle *mh;
2863 int to_nodeid, error;
2864
2865 to_nodeid = lkb->lkb_nodeid;
2866
2867 error = create_message(r, lkb, to_nodeid, DLM_MSG_GRANT, &ms, &mh);
2868 if (error)
2869 goto out;
2870
2871 send_args(r, lkb, ms);
2872
2873 ms->m_result = 0;
2874
2875 error = send_message(mh, ms);
2876 out:
2877 return error;
2878 }
2879
2880 static int send_bast(struct dlm_rsb *r, struct dlm_lkb *lkb, int mode)
2881 {
2882 struct dlm_message *ms;
2883 struct dlm_mhandle *mh;
2884 int to_nodeid, error;
2885
2886 to_nodeid = lkb->lkb_nodeid;
2887
2888 error = create_message(r, NULL, to_nodeid, DLM_MSG_BAST, &ms, &mh);
2889 if (error)
2890 goto out;
2891
2892 send_args(r, lkb, ms);
2893
2894 ms->m_bastmode = mode;
2895
2896 error = send_message(mh, ms);
2897 out:
2898 return error;
2899 }
2900
2901 static int send_lookup(struct dlm_rsb *r, struct dlm_lkb *lkb)
2902 {
2903 struct dlm_message *ms;
2904 struct dlm_mhandle *mh;
2905 int to_nodeid, error;
2906
2907 error = add_to_waiters(lkb, DLM_MSG_LOOKUP);
2908 if (error)
2909 return error;
2910
2911 to_nodeid = dlm_dir_nodeid(r);
2912
2913 error = create_message(r, NULL, to_nodeid, DLM_MSG_LOOKUP, &ms, &mh);
2914 if (error)
2915 goto fail;
2916
2917 send_args(r, lkb, ms);
2918
2919 error = send_message(mh, ms);
2920 if (error)
2921 goto fail;
2922 return 0;
2923
2924 fail:
2925 remove_from_waiters(lkb, DLM_MSG_LOOKUP_REPLY);
2926 return error;
2927 }
2928
2929 static int send_remove(struct dlm_rsb *r)
2930 {
2931 struct dlm_message *ms;
2932 struct dlm_mhandle *mh;
2933 int to_nodeid, error;
2934
2935 to_nodeid = dlm_dir_nodeid(r);
2936
2937 error = create_message(r, NULL, to_nodeid, DLM_MSG_REMOVE, &ms, &mh);
2938 if (error)
2939 goto out;
2940
2941 memcpy(ms->m_extra, r->res_name, r->res_length);
2942 ms->m_hash = r->res_hash;
2943
2944 error = send_message(mh, ms);
2945 out:
2946 return error;
2947 }
2948
2949 static int send_common_reply(struct dlm_rsb *r, struct dlm_lkb *lkb,
2950 int mstype, int rv)
2951 {
2952 struct dlm_message *ms;
2953 struct dlm_mhandle *mh;
2954 int to_nodeid, error;
2955
2956 to_nodeid = lkb->lkb_nodeid;
2957
2958 error = create_message(r, lkb, to_nodeid, mstype, &ms, &mh);
2959 if (error)
2960 goto out;
2961
2962 send_args(r, lkb, ms);
2963
2964 ms->m_result = rv;
2965
2966 error = send_message(mh, ms);
2967 out:
2968 return error;
2969 }
2970
2971 static int send_request_reply(struct dlm_rsb *r, struct dlm_lkb *lkb, int rv)
2972 {
2973 return send_common_reply(r, lkb, DLM_MSG_REQUEST_REPLY, rv);
2974 }
2975
2976 static int send_convert_reply(struct dlm_rsb *r, struct dlm_lkb *lkb, int rv)
2977 {
2978 return send_common_reply(r, lkb, DLM_MSG_CONVERT_REPLY, rv);
2979 }
2980
2981 static int send_unlock_reply(struct dlm_rsb *r, struct dlm_lkb *lkb, int rv)
2982 {
2983 return send_common_reply(r, lkb, DLM_MSG_UNLOCK_REPLY, rv);
2984 }
2985
2986 static int send_cancel_reply(struct dlm_rsb *r, struct dlm_lkb *lkb, int rv)
2987 {
2988 return send_common_reply(r, lkb, DLM_MSG_CANCEL_REPLY, rv);
2989 }
2990
2991 static int send_lookup_reply(struct dlm_ls *ls, struct dlm_message *ms_in,
2992 int ret_nodeid, int rv)
2993 {
2994 struct dlm_rsb *r = &ls->ls_stub_rsb;
2995 struct dlm_message *ms;
2996 struct dlm_mhandle *mh;
2997 int error, nodeid = ms_in->m_header.h_nodeid;
2998
2999 error = create_message(r, NULL, nodeid, DLM_MSG_LOOKUP_REPLY, &ms, &mh);
3000 if (error)
3001 goto out;
3002
3003 ms->m_lkid = ms_in->m_lkid;
3004 ms->m_result = rv;
3005 ms->m_nodeid = ret_nodeid;
3006
3007 error = send_message(mh, ms);
3008 out:
3009 return error;
3010 }
3011
3012 /* which args we save from a received message depends heavily on the type
3013 of message, unlike the send side where we can safely send everything about
3014 the lkb for any type of message */
3015
3016 static void receive_flags(struct dlm_lkb *lkb, struct dlm_message *ms)
3017 {
3018 lkb->lkb_exflags = ms->m_exflags;
3019 lkb->lkb_sbflags = ms->m_sbflags;
3020 lkb->lkb_flags = (lkb->lkb_flags & 0xFFFF0000) |
3021 (ms->m_flags & 0x0000FFFF);
3022 }
3023
3024 static void receive_flags_reply(struct dlm_lkb *lkb, struct dlm_message *ms)
3025 {
3026 lkb->lkb_sbflags = ms->m_sbflags;
3027 lkb->lkb_flags = (lkb->lkb_flags & 0xFFFF0000) |
3028 (ms->m_flags & 0x0000FFFF);
3029 }
3030
3031 static int receive_extralen(struct dlm_message *ms)
3032 {
3033 return (ms->m_header.h_length - sizeof(struct dlm_message));
3034 }
3035
3036 static int receive_lvb(struct dlm_ls *ls, struct dlm_lkb *lkb,
3037 struct dlm_message *ms)
3038 {
3039 int len;
3040
3041 if (lkb->lkb_exflags & DLM_LKF_VALBLK) {
3042 if (!lkb->lkb_lvbptr)
3043 lkb->lkb_lvbptr = dlm_allocate_lvb(ls);
3044 if (!lkb->lkb_lvbptr)
3045 return -ENOMEM;
3046 len = receive_extralen(ms);
3047 if (len > DLM_RESNAME_MAXLEN)
3048 len = DLM_RESNAME_MAXLEN;
3049 memcpy(lkb->lkb_lvbptr, ms->m_extra, len);
3050 }
3051 return 0;
3052 }
3053
3054 static void fake_bastfn(void *astparam, int mode)
3055 {
3056 log_print("fake_bastfn should not be called");
3057 }
3058
3059 static void fake_astfn(void *astparam)
3060 {
3061 log_print("fake_astfn should not be called");
3062 }
3063
3064 static int receive_request_args(struct dlm_ls *ls, struct dlm_lkb *lkb,
3065 struct dlm_message *ms)
3066 {
3067 lkb->lkb_nodeid = ms->m_header.h_nodeid;
3068 lkb->lkb_ownpid = ms->m_pid;
3069 lkb->lkb_remid = ms->m_lkid;
3070 lkb->lkb_grmode = DLM_LOCK_IV;
3071 lkb->lkb_rqmode = ms->m_rqmode;
3072
3073 lkb->lkb_bastfn = (ms->m_asts & AST_BAST) ? &fake_bastfn : NULL;
3074 lkb->lkb_astfn = (ms->m_asts & AST_COMP) ? &fake_astfn : NULL;
3075
3076 if (lkb->lkb_exflags & DLM_LKF_VALBLK) {
3077 /* lkb was just created so there won't be an lvb yet */
3078 lkb->lkb_lvbptr = dlm_allocate_lvb(ls);
3079 if (!lkb->lkb_lvbptr)
3080 return -ENOMEM;
3081 }
3082
3083 return 0;
3084 }
3085
3086 static int receive_convert_args(struct dlm_ls *ls, struct dlm_lkb *lkb,
3087 struct dlm_message *ms)
3088 {
3089 if (lkb->lkb_status != DLM_LKSTS_GRANTED)
3090 return -EBUSY;
3091
3092 if (receive_lvb(ls, lkb, ms))
3093 return -ENOMEM;
3094
3095 lkb->lkb_rqmode = ms->m_rqmode;
3096 lkb->lkb_lvbseq = ms->m_lvbseq;
3097
3098 return 0;
3099 }
3100
3101 static int receive_unlock_args(struct dlm_ls *ls, struct dlm_lkb *lkb,
3102 struct dlm_message *ms)
3103 {
3104 if (receive_lvb(ls, lkb, ms))
3105 return -ENOMEM;
3106 return 0;
3107 }
3108
3109 /* We fill in the stub-lkb fields with the info that send_xxxx_reply()
3110 uses to send a reply and that the remote end uses to process the reply. */
3111
3112 static void setup_stub_lkb(struct dlm_ls *ls, struct dlm_message *ms)
3113 {
3114 struct dlm_lkb *lkb = &ls->ls_stub_lkb;
3115 lkb->lkb_nodeid = ms->m_header.h_nodeid;
3116 lkb->lkb_remid = ms->m_lkid;
3117 }
3118
3119 /* This is called after the rsb is locked so that we can safely inspect
3120 fields in the lkb. */
3121
3122 static int validate_message(struct dlm_lkb *lkb, struct dlm_message *ms)
3123 {
3124 int from = ms->m_header.h_nodeid;
3125 int error = 0;
3126
3127 switch (ms->m_type) {
3128 case DLM_MSG_CONVERT:
3129 case DLM_MSG_UNLOCK:
3130 case DLM_MSG_CANCEL:
3131 if (!is_master_copy(lkb) || lkb->lkb_nodeid != from)
3132 error = -EINVAL;
3133 break;
3134
3135 case DLM_MSG_CONVERT_REPLY:
3136 case DLM_MSG_UNLOCK_REPLY:
3137 case DLM_MSG_CANCEL_REPLY:
3138 case DLM_MSG_GRANT:
3139 case DLM_MSG_BAST:
3140 if (!is_process_copy(lkb) || lkb->lkb_nodeid != from)
3141 error = -EINVAL;
3142 break;
3143
3144 case DLM_MSG_REQUEST_REPLY:
3145 if (!is_process_copy(lkb))
3146 error = -EINVAL;
3147 else if (lkb->lkb_nodeid != -1 && lkb->lkb_nodeid != from)
3148 error = -EINVAL;
3149 break;
3150
3151 default:
3152 error = -EINVAL;
3153 }
3154
3155 if (error)
3156 log_error(lkb->lkb_resource->res_ls,
3157 "ignore invalid message %d from %d %x %x %x %d",
3158 ms->m_type, from, lkb->lkb_id, lkb->lkb_remid,
3159 lkb->lkb_flags, lkb->lkb_nodeid);
3160 return error;
3161 }
3162
3163 static void receive_request(struct dlm_ls *ls, struct dlm_message *ms)
3164 {
3165 struct dlm_lkb *lkb;
3166 struct dlm_rsb *r;
3167 int error, namelen;
3168
3169 error = create_lkb(ls, &lkb);
3170 if (error)
3171 goto fail;
3172
3173 receive_flags(lkb, ms);
3174 lkb->lkb_flags |= DLM_IFL_MSTCPY;
3175 error = receive_request_args(ls, lkb, ms);
3176 if (error) {
3177 __put_lkb(ls, lkb);
3178 goto fail;
3179 }
3180
3181 namelen = receive_extralen(ms);
3182
3183 error = find_rsb(ls, ms->m_extra, namelen, R_MASTER, &r);
3184 if (error) {
3185 __put_lkb(ls, lkb);
3186 goto fail;
3187 }
3188
3189 lock_rsb(r);
3190
3191 attach_lkb(r, lkb);
3192 error = do_request(r, lkb);
3193 send_request_reply(r, lkb, error);
3194
3195 unlock_rsb(r);
3196 put_rsb(r);
3197
3198 if (error == -EINPROGRESS)
3199 error = 0;
3200 if (error)
3201 dlm_put_lkb(lkb);
3202 return;
3203
3204 fail:
3205 setup_stub_lkb(ls, ms);
3206 send_request_reply(&ls->ls_stub_rsb, &ls->ls_stub_lkb, error);
3207 }
3208
3209 static void receive_convert(struct dlm_ls *ls, struct dlm_message *ms)
3210 {
3211 struct dlm_lkb *lkb;
3212 struct dlm_rsb *r;
3213 int error, reply = 1;
3214
3215 error = find_lkb(ls, ms->m_remid, &lkb);
3216 if (error)
3217 goto fail;
3218
3219 r = lkb->lkb_resource;
3220
3221 hold_rsb(r);
3222 lock_rsb(r);
3223
3224 error = validate_message(lkb, ms);
3225 if (error)
3226 goto out;
3227
3228 receive_flags(lkb, ms);
3229 error = receive_convert_args(ls, lkb, ms);
3230 if (error)
3231 goto out_reply;
3232 reply = !down_conversion(lkb);
3233
3234 error = do_convert(r, lkb);
3235 out_reply:
3236 if (reply)
3237 send_convert_reply(r, lkb, error);
3238 out:
3239 unlock_rsb(r);
3240 put_rsb(r);
3241 dlm_put_lkb(lkb);
3242 return;
3243
3244 fail:
3245 setup_stub_lkb(ls, ms);
3246 send_convert_reply(&ls->ls_stub_rsb, &ls->ls_stub_lkb, error);
3247 }
3248
3249 static void receive_unlock(struct dlm_ls *ls, struct dlm_message *ms)
3250 {
3251 struct dlm_lkb *lkb;
3252 struct dlm_rsb *r;
3253 int error;
3254
3255 error = find_lkb(ls, ms->m_remid, &lkb);
3256 if (error)
3257 goto fail;
3258
3259 r = lkb->lkb_resource;
3260
3261 hold_rsb(r);
3262 lock_rsb(r);
3263
3264 error = validate_message(lkb, ms);
3265 if (error)
3266 goto out;
3267
3268 receive_flags(lkb, ms);
3269 error = receive_unlock_args(ls, lkb, ms);
3270 if (error)
3271 goto out_reply;
3272
3273 error = do_unlock(r, lkb);
3274 out_reply:
3275 send_unlock_reply(r, lkb, error);
3276 out:
3277 unlock_rsb(r);
3278 put_rsb(r);
3279 dlm_put_lkb(lkb);
3280 return;
3281
3282 fail:
3283 setup_stub_lkb(ls, ms);
3284 send_unlock_reply(&ls->ls_stub_rsb, &ls->ls_stub_lkb, error);
3285 }
3286
3287 static void receive_cancel(struct dlm_ls *ls, struct dlm_message *ms)
3288 {
3289 struct dlm_lkb *lkb;
3290 struct dlm_rsb *r;
3291 int error;
3292
3293 error = find_lkb(ls, ms->m_remid, &lkb);
3294 if (error)
3295 goto fail;
3296
3297 receive_flags(lkb, ms);
3298
3299 r = lkb->lkb_resource;
3300
3301 hold_rsb(r);
3302 lock_rsb(r);
3303
3304 error = validate_message(lkb, ms);
3305 if (error)
3306 goto out;
3307
3308 error = do_cancel(r, lkb);
3309 send_cancel_reply(r, lkb, error);
3310 out:
3311 unlock_rsb(r);
3312 put_rsb(r);
3313 dlm_put_lkb(lkb);
3314 return;
3315
3316 fail:
3317 setup_stub_lkb(ls, ms);
3318 send_cancel_reply(&ls->ls_stub_rsb, &ls->ls_stub_lkb, error);
3319 }
3320
3321 static void receive_grant(struct dlm_ls *ls, struct dlm_message *ms)
3322 {
3323 struct dlm_lkb *lkb;
3324 struct dlm_rsb *r;
3325 int error;
3326
3327 error = find_lkb(ls, ms->m_remid, &lkb);
3328 if (error) {
3329 log_debug(ls, "receive_grant from %d no lkb %x",
3330 ms->m_header.h_nodeid, ms->m_remid);
3331 return;
3332 }
3333
3334 r = lkb->lkb_resource;
3335
3336 hold_rsb(r);
3337 lock_rsb(r);
3338
3339 error = validate_message(lkb, ms);
3340 if (error)
3341 goto out;
3342
3343 receive_flags_reply(lkb, ms);
3344 if (is_altmode(lkb))
3345 munge_altmode(lkb, ms);
3346 grant_lock_pc(r, lkb, ms);
3347 queue_cast(r, lkb, 0);
3348 out:
3349 unlock_rsb(r);
3350 put_rsb(r);
3351 dlm_put_lkb(lkb);
3352 }
3353
3354 static void receive_bast(struct dlm_ls *ls, struct dlm_message *ms)
3355 {
3356 struct dlm_lkb *lkb;
3357 struct dlm_rsb *r;
3358 int error;
3359
3360 error = find_lkb(ls, ms->m_remid, &lkb);
3361 if (error) {
3362 log_debug(ls, "receive_bast from %d no lkb %x",
3363 ms->m_header.h_nodeid, ms->m_remid);
3364 return;
3365 }
3366
3367 r = lkb->lkb_resource;
3368
3369 hold_rsb(r);
3370 lock_rsb(r);
3371
3372 error = validate_message(lkb, ms);
3373 if (error)
3374 goto out;
3375
3376 queue_bast(r, lkb, ms->m_bastmode);
3377 out:
3378 unlock_rsb(r);
3379 put_rsb(r);
3380 dlm_put_lkb(lkb);
3381 }
3382
3383 static void receive_lookup(struct dlm_ls *ls, struct dlm_message *ms)
3384 {
3385 int len, error, ret_nodeid, dir_nodeid, from_nodeid, our_nodeid;
3386
3387 from_nodeid = ms->m_header.h_nodeid;
3388 our_nodeid = dlm_our_nodeid();
3389
3390 len = receive_extralen(ms);
3391
3392 dir_nodeid = dlm_hash2nodeid(ls, ms->m_hash);
3393 if (dir_nodeid != our_nodeid) {
3394 log_error(ls, "lookup dir_nodeid %d from %d",
3395 dir_nodeid, from_nodeid);
3396 error = -EINVAL;
3397 ret_nodeid = -1;
3398 goto out;
3399 }
3400
3401 error = dlm_dir_lookup(ls, from_nodeid, ms->m_extra, len, &ret_nodeid);
3402
3403 /* Optimization: we're master so treat lookup as a request */
3404 if (!error && ret_nodeid == our_nodeid) {
3405 receive_request(ls, ms);
3406 return;
3407 }
3408 out:
3409 send_lookup_reply(ls, ms, ret_nodeid, error);
3410 }
3411
3412 static void receive_remove(struct dlm_ls *ls, struct dlm_message *ms)
3413 {
3414 int len, dir_nodeid, from_nodeid;
3415
3416 from_nodeid = ms->m_header.h_nodeid;
3417
3418 len = receive_extralen(ms);
3419
3420 dir_nodeid = dlm_hash2nodeid(ls, ms->m_hash);
3421 if (dir_nodeid != dlm_our_nodeid()) {
3422 log_error(ls, "remove dir entry dir_nodeid %d from %d",
3423 dir_nodeid, from_nodeid);
3424 return;
3425 }
3426
3427 dlm_dir_remove_entry(ls, from_nodeid, ms->m_extra, len);
3428 }
3429
3430 static void receive_purge(struct dlm_ls *ls, struct dlm_message *ms)
3431 {
3432 do_purge(ls, ms->m_nodeid, ms->m_pid);
3433 }
3434
3435 static void receive_request_reply(struct dlm_ls *ls, struct dlm_message *ms)
3436 {
3437 struct dlm_lkb *lkb;
3438 struct dlm_rsb *r;
3439 int error, mstype, result;
3440
3441 error = find_lkb(ls, ms->m_remid, &lkb);
3442 if (error) {
3443 log_debug(ls, "receive_request_reply from %d no lkb %x",
3444 ms->m_header.h_nodeid, ms->m_remid);
3445 return;
3446 }
3447
3448 r = lkb->lkb_resource;
3449 hold_rsb(r);
3450 lock_rsb(r);
3451
3452 error = validate_message(lkb, ms);
3453 if (error)
3454 goto out;
3455
3456 mstype = lkb->lkb_wait_type;
3457 error = remove_from_waiters(lkb, DLM_MSG_REQUEST_REPLY);
3458 if (error)
3459 goto out;
3460
3461 /* Optimization: the dir node was also the master, so it took our
3462 lookup as a request and sent request reply instead of lookup reply */
3463 if (mstype == DLM_MSG_LOOKUP) {
3464 r->res_nodeid = ms->m_header.h_nodeid;
3465 lkb->lkb_nodeid = r->res_nodeid;
3466 }
3467
3468 /* this is the value returned from do_request() on the master */
3469 result = ms->m_result;
3470
3471 switch (result) {
3472 case -EAGAIN:
3473 /* request would block (be queued) on remote master */
3474 queue_cast(r, lkb, -EAGAIN);
3475 confirm_master(r, -EAGAIN);
3476 unhold_lkb(lkb); /* undoes create_lkb() */
3477 break;
3478
3479 case -EINPROGRESS:
3480 case 0:
3481 /* request was queued or granted on remote master */
3482 receive_flags_reply(lkb, ms);
3483 lkb->lkb_remid = ms->m_lkid;
3484 if (is_altmode(lkb))
3485 munge_altmode(lkb, ms);
3486 if (result) {
3487 add_lkb(r, lkb, DLM_LKSTS_WAITING);
3488 add_timeout(lkb);
3489 } else {
3490 grant_lock_pc(r, lkb, ms);
3491 queue_cast(r, lkb, 0);
3492 }
3493 confirm_master(r, result);
3494 break;
3495
3496 case -EBADR:
3497 case -ENOTBLK:
3498 /* find_rsb failed to find rsb or rsb wasn't master */
3499 log_debug(ls, "receive_request_reply %x %x master diff %d %d",
3500 lkb->lkb_id, lkb->lkb_flags, r->res_nodeid, result);
3501 r->res_nodeid = -1;
3502 lkb->lkb_nodeid = -1;
3503
3504 if (is_overlap(lkb)) {
3505 /* we'll ignore error in cancel/unlock reply */
3506 queue_cast_overlap(r, lkb);
3507 confirm_master(r, result);
3508 unhold_lkb(lkb); /* undoes create_lkb() */
3509 } else
3510 _request_lock(r, lkb);
3511 break;
3512
3513 default:
3514 log_error(ls, "receive_request_reply %x error %d",
3515 lkb->lkb_id, result);
3516 }
3517
3518 if (is_overlap_unlock(lkb) && (result == 0 || result == -EINPROGRESS)) {
3519 log_debug(ls, "receive_request_reply %x result %d unlock",
3520 lkb->lkb_id, result);
3521 lkb->lkb_flags &= ~DLM_IFL_OVERLAP_UNLOCK;
3522 lkb->lkb_flags &= ~DLM_IFL_OVERLAP_CANCEL;
3523 send_unlock(r, lkb);
3524 } else if (is_overlap_cancel(lkb) && (result == -EINPROGRESS)) {
3525 log_debug(ls, "receive_request_reply %x cancel", lkb->lkb_id);
3526 lkb->lkb_flags &= ~DLM_IFL_OVERLAP_UNLOCK;
3527 lkb->lkb_flags &= ~DLM_IFL_OVERLAP_CANCEL;
3528 send_cancel(r, lkb);
3529 } else {
3530 lkb->lkb_flags &= ~DLM_IFL_OVERLAP_CANCEL;
3531 lkb->lkb_flags &= ~DLM_IFL_OVERLAP_UNLOCK;
3532 }
3533 out:
3534 unlock_rsb(r);
3535 put_rsb(r);
3536 dlm_put_lkb(lkb);
3537 }
3538
3539 static void __receive_convert_reply(struct dlm_rsb *r, struct dlm_lkb *lkb,
3540 struct dlm_message *ms)
3541 {
3542 /* this is the value returned from do_convert() on the master */
3543 switch (ms->m_result) {
3544 case -EAGAIN:
3545 /* convert would block (be queued) on remote master */
3546 queue_cast(r, lkb, -EAGAIN);
3547 break;
3548
3549 case -EDEADLK:
3550 receive_flags_reply(lkb, ms);
3551 revert_lock_pc(r, lkb);
3552 queue_cast(r, lkb, -EDEADLK);
3553 break;
3554
3555 case -EINPROGRESS:
3556 /* convert was queued on remote master */
3557 receive_flags_reply(lkb, ms);
3558 if (is_demoted(lkb))
3559 munge_demoted(lkb, ms);
3560 del_lkb(r, lkb);
3561 add_lkb(r, lkb, DLM_LKSTS_CONVERT);
3562 add_timeout(lkb);
3563 break;
3564
3565 case 0:
3566 /* convert was granted on remote master */
3567 receive_flags_reply(lkb, ms);
3568 if (is_demoted(lkb))
3569 munge_demoted(lkb, ms);
3570 grant_lock_pc(r, lkb, ms);
3571 queue_cast(r, lkb, 0);
3572 break;
3573
3574 default:
3575 log_error(r->res_ls, "receive_convert_reply %x error %d",
3576 lkb->lkb_id, ms->m_result);
3577 }
3578 }
3579
3580 static void _receive_convert_reply(struct dlm_lkb *lkb, struct dlm_message *ms)
3581 {
3582 struct dlm_rsb *r = lkb->lkb_resource;
3583 int error;
3584
3585 hold_rsb(r);
3586 lock_rsb(r);
3587
3588 error = validate_message(lkb, ms);
3589 if (error)
3590 goto out;
3591
3592 /* stub reply can happen with waiters_mutex held */
3593 error = remove_from_waiters_ms(lkb, ms);
3594 if (error)
3595 goto out;
3596
3597 __receive_convert_reply(r, lkb, ms);
3598 out:
3599 unlock_rsb(r);
3600 put_rsb(r);
3601 }
3602
3603 static void receive_convert_reply(struct dlm_ls *ls, struct dlm_message *ms)
3604 {
3605 struct dlm_lkb *lkb;
3606 int error;
3607
3608 error = find_lkb(ls, ms->m_remid, &lkb);
3609 if (error) {
3610 log_debug(ls, "receive_convert_reply from %d no lkb %x",
3611 ms->m_header.h_nodeid, ms->m_remid);
3612 return;
3613 }
3614
3615 _receive_convert_reply(lkb, ms);
3616 dlm_put_lkb(lkb);
3617 }
3618
3619 static void _receive_unlock_reply(struct dlm_lkb *lkb, struct dlm_message *ms)
3620 {
3621 struct dlm_rsb *r = lkb->lkb_resource;
3622 int error;
3623
3624 hold_rsb(r);
3625 lock_rsb(r);
3626
3627 error = validate_message(lkb, ms);
3628 if (error)
3629 goto out;
3630
3631 /* stub reply can happen with waiters_mutex held */
3632 error = remove_from_waiters_ms(lkb, ms);
3633 if (error)
3634 goto out;
3635
3636 /* this is the value returned from do_unlock() on the master */
3637
3638 switch (ms->m_result) {
3639 case -DLM_EUNLOCK:
3640 receive_flags_reply(lkb, ms);
3641 remove_lock_pc(r, lkb);
3642 queue_cast(r, lkb, -DLM_EUNLOCK);
3643 break;
3644 case -ENOENT:
3645 break;
3646 default:
3647 log_error(r->res_ls, "receive_unlock_reply %x error %d",
3648 lkb->lkb_id, ms->m_result);
3649 }
3650 out:
3651 unlock_rsb(r);
3652 put_rsb(r);
3653 }
3654
3655 static void receive_unlock_reply(struct dlm_ls *ls, struct dlm_message *ms)
3656 {
3657 struct dlm_lkb *lkb;
3658 int error;
3659
3660 error = find_lkb(ls, ms->m_remid, &lkb);
3661 if (error) {
3662 log_debug(ls, "receive_unlock_reply from %d no lkb %x",
3663 ms->m_header.h_nodeid, ms->m_remid);
3664 return;
3665 }
3666
3667 _receive_unlock_reply(lkb, ms);
3668 dlm_put_lkb(lkb);
3669 }
3670
3671 static void _receive_cancel_reply(struct dlm_lkb *lkb, struct dlm_message *ms)
3672 {
3673 struct dlm_rsb *r = lkb->lkb_resource;
3674 int error;
3675
3676 hold_rsb(r);
3677 lock_rsb(r);
3678
3679 error = validate_message(lkb, ms);
3680 if (error)
3681 goto out;
3682
3683 /* stub reply can happen with waiters_mutex held */
3684 error = remove_from_waiters_ms(lkb, ms);
3685 if (error)
3686 goto out;
3687
3688 /* this is the value returned from do_cancel() on the master */
3689
3690 switch (ms->m_result) {
3691 case -DLM_ECANCEL:
3692 receive_flags_reply(lkb, ms);
3693 revert_lock_pc(r, lkb);
3694 queue_cast(r, lkb, -DLM_ECANCEL);
3695 break;
3696 case 0:
3697 break;
3698 default:
3699 log_error(r->res_ls, "receive_cancel_reply %x error %d",
3700 lkb->lkb_id, ms->m_result);
3701 }
3702 out:
3703 unlock_rsb(r);
3704 put_rsb(r);
3705 }
3706
3707 static void receive_cancel_reply(struct dlm_ls *ls, struct dlm_message *ms)
3708 {
3709 struct dlm_lkb *lkb;
3710 int error;
3711
3712 error = find_lkb(ls, ms->m_remid, &lkb);
3713 if (error) {
3714 log_debug(ls, "receive_cancel_reply from %d no lkb %x",
3715 ms->m_header.h_nodeid, ms->m_remid);
3716 return;
3717 }
3718
3719 _receive_cancel_reply(lkb, ms);
3720 dlm_put_lkb(lkb);
3721 }
3722
3723 static void receive_lookup_reply(struct dlm_ls *ls, struct dlm_message *ms)
3724 {
3725 struct dlm_lkb *lkb;
3726 struct dlm_rsb *r;
3727 int error, ret_nodeid;
3728
3729 error = find_lkb(ls, ms->m_lkid, &lkb);
3730 if (error) {
3731 log_error(ls, "receive_lookup_reply no lkb");
3732 return;
3733 }
3734
3735 /* ms->m_result is the value returned by dlm_dir_lookup on dir node
3736 FIXME: will a non-zero error ever be returned? */
3737
3738 r = lkb->lkb_resource;
3739 hold_rsb(r);
3740 lock_rsb(r);
3741
3742 error = remove_from_waiters(lkb, DLM_MSG_LOOKUP_REPLY);
3743 if (error)
3744 goto out;
3745
3746 ret_nodeid = ms->m_nodeid;
3747 if (ret_nodeid == dlm_our_nodeid()) {
3748 r->res_nodeid = 0;
3749 ret_nodeid = 0;
3750 r->res_first_lkid = 0;
3751 } else {
3752 /* set_master() will copy res_nodeid to lkb_nodeid */
3753 r->res_nodeid = ret_nodeid;
3754 }
3755
3756 if (is_overlap(lkb)) {
3757 log_debug(ls, "receive_lookup_reply %x unlock %x",
3758 lkb->lkb_id, lkb->lkb_flags);
3759 queue_cast_overlap(r, lkb);
3760 unhold_lkb(lkb); /* undoes create_lkb() */
3761 goto out_list;
3762 }
3763
3764 _request_lock(r, lkb);
3765
3766 out_list:
3767 if (!ret_nodeid)
3768 process_lookup_list(r);
3769 out:
3770 unlock_rsb(r);
3771 put_rsb(r);
3772 dlm_put_lkb(lkb);
3773 }
3774
3775 static void _receive_message(struct dlm_ls *ls, struct dlm_message *ms)
3776 {
3777 if (!dlm_is_member(ls, ms->m_header.h_nodeid)) {
3778 log_debug(ls, "ignore non-member message %d from %d %x %x %d",
3779 ms->m_type, ms->m_header.h_nodeid, ms->m_lkid,
3780 ms->m_remid, ms->m_result);
3781 return;
3782 }
3783
3784 switch (ms->m_type) {
3785
3786 /* messages sent to a master node */
3787
3788 case DLM_MSG_REQUEST:
3789 receive_request(ls, ms);
3790 break;
3791
3792 case DLM_MSG_CONVERT:
3793 receive_convert(ls, ms);
3794 break;
3795
3796 case DLM_MSG_UNLOCK:
3797 receive_unlock(ls, ms);
3798 break;
3799
3800 case DLM_MSG_CANCEL:
3801 receive_cancel(ls, ms);
3802 break;
3803
3804 /* messages sent from a master node (replies to above) */
3805
3806 case DLM_MSG_REQUEST_REPLY:
3807 receive_request_reply(ls, ms);
3808 break;
3809
3810 case DLM_MSG_CONVERT_REPLY:
3811 receive_convert_reply(ls, ms);
3812 break;
3813
3814 case DLM_MSG_UNLOCK_REPLY:
3815 receive_unlock_reply(ls, ms);
3816 break;
3817
3818 case DLM_MSG_CANCEL_REPLY:
3819 receive_cancel_reply(ls, ms);
3820 break;
3821
3822 /* messages sent from a master node (only two types of async msg) */
3823
3824 case DLM_MSG_GRANT:
3825 receive_grant(ls, ms);
3826 break;
3827
3828 case DLM_MSG_BAST:
3829 receive_bast(ls, ms);
3830 break;
3831
3832 /* messages sent to a dir node */
3833
3834 case DLM_MSG_LOOKUP:
3835 receive_lookup(ls, ms);
3836 break;
3837
3838 case DLM_MSG_REMOVE:
3839 receive_remove(ls, ms);
3840 break;
3841
3842 /* messages sent from a dir node (remove has no reply) */
3843
3844 case DLM_MSG_LOOKUP_REPLY:
3845 receive_lookup_reply(ls, ms);
3846 break;
3847
3848 /* other messages */
3849
3850 case DLM_MSG_PURGE:
3851 receive_purge(ls, ms);
3852 break;
3853
3854 default:
3855 log_error(ls, "unknown message type %d", ms->m_type);
3856 }
3857
3858 dlm_astd_wake();
3859 }
3860
3861 /* If the lockspace is in recovery mode (locking stopped), then normal
3862 messages are saved on the requestqueue for processing after recovery is
3863 done. When not in recovery mode, we wait for dlm_recoverd to drain saved
3864 messages off the requestqueue before we process new ones. This occurs right
3865 after recovery completes when we transition from saving all messages on
3866 requestqueue, to processing all the saved messages, to processing new
3867 messages as they arrive. */
3868
3869 static void dlm_receive_message(struct dlm_ls *ls, struct dlm_message *ms,
3870 int nodeid)
3871 {
3872 if (dlm_locking_stopped(ls)) {
3873 dlm_add_requestqueue(ls, nodeid, ms);
3874 } else {
3875 dlm_wait_requestqueue(ls);
3876 _receive_message(ls, ms);
3877 }
3878 }
3879
3880 /* This is called by dlm_recoverd to process messages that were saved on
3881 the requestqueue. */
3882
3883 void dlm_receive_message_saved(struct dlm_ls *ls, struct dlm_message *ms)
3884 {
3885 _receive_message(ls, ms);
3886 }
3887
3888 /* This is called by the midcomms layer when something is received for
3889 the lockspace. It could be either a MSG (normal message sent as part of
3890 standard locking activity) or an RCOM (recovery message sent as part of
3891 lockspace recovery). */
3892
3893 void dlm_receive_buffer(union dlm_packet *p, int nodeid)
3894 {
3895 struct dlm_header *hd = &p->header;
3896 struct dlm_ls *ls;
3897 int type = 0;
3898
3899 switch (hd->h_cmd) {
3900 case DLM_MSG:
3901 dlm_message_in(&p->message);
3902 type = p->message.m_type;
3903 break;
3904 case DLM_RCOM:
3905 dlm_rcom_in(&p->rcom);
3906 type = p->rcom.rc_type;
3907 break;
3908 default:
3909 log_print("invalid h_cmd %d from %u", hd->h_cmd, nodeid);
3910 return;
3911 }
3912
3913 if (hd->h_nodeid != nodeid) {
3914 log_print("invalid h_nodeid %d from %d lockspace %x",
3915 hd->h_nodeid, nodeid, hd->h_lockspace);
3916 return;
3917 }
3918
3919 ls = dlm_find_lockspace_global(hd->h_lockspace);
3920 if (!ls) {
3921 if (dlm_config.ci_log_debug)
3922 log_print("invalid lockspace %x from %d cmd %d type %d",
3923 hd->h_lockspace, nodeid, hd->h_cmd, type);
3924
3925 if (hd->h_cmd == DLM_RCOM && type == DLM_RCOM_STATUS)
3926 dlm_send_ls_not_ready(nodeid, &p->rcom);
3927 return;
3928 }
3929
3930 /* this rwsem allows dlm_ls_stop() to wait for all dlm_recv threads to
3931 be inactive (in this ls) before transitioning to recovery mode */
3932
3933 down_read(&ls->ls_recv_active);
3934 if (hd->h_cmd == DLM_MSG)
3935 dlm_receive_message(ls, &p->message, nodeid);
3936 else
3937 dlm_receive_rcom(ls, &p->rcom, nodeid);
3938 up_read(&ls->ls_recv_active);
3939
3940 dlm_put_lockspace(ls);
3941 }
3942
3943 static void recover_convert_waiter(struct dlm_ls *ls, struct dlm_lkb *lkb)
3944 {
3945 if (middle_conversion(lkb)) {
3946 hold_lkb(lkb);
3947 ls->ls_stub_ms.m_type = DLM_MSG_CONVERT_REPLY;
3948 ls->ls_stub_ms.m_result = -EINPROGRESS;
3949 ls->ls_stub_ms.m_flags = lkb->lkb_flags;
3950 ls->ls_stub_ms.m_header.h_nodeid = lkb->lkb_nodeid;
3951 _receive_convert_reply(lkb, &ls->ls_stub_ms);
3952
3953 /* Same special case as in receive_rcom_lock_args() */
3954 lkb->lkb_grmode = DLM_LOCK_IV;
3955 rsb_set_flag(lkb->lkb_resource, RSB_RECOVER_CONVERT);
3956 unhold_lkb(lkb);
3957
3958 } else if (lkb->lkb_rqmode >= lkb->lkb_grmode) {
3959 lkb->lkb_flags |= DLM_IFL_RESEND;
3960 }
3961
3962 /* lkb->lkb_rqmode < lkb->lkb_grmode shouldn't happen since down
3963 conversions are async; there's no reply from the remote master */
3964 }
3965
3966 /* A waiting lkb needs recovery if the master node has failed, or
3967 the master node is changing (only when no directory is used) */
3968
3969 static int waiter_needs_recovery(struct dlm_ls *ls, struct dlm_lkb *lkb)
3970 {
3971 if (dlm_is_removed(ls, lkb->lkb_nodeid))
3972 return 1;
3973
3974 if (!dlm_no_directory(ls))
3975 return 0;
3976
3977 if (dlm_dir_nodeid(lkb->lkb_resource) != lkb->lkb_nodeid)
3978 return 1;
3979
3980 return 0;
3981 }
3982
3983 /* Recovery for locks that are waiting for replies from nodes that are now
3984 gone. We can just complete unlocks and cancels by faking a reply from the
3985 dead node. Requests and up-conversions we flag to be resent after
3986 recovery. Down-conversions can just be completed with a fake reply like
3987 unlocks. Conversions between PR and CW need special attention. */
3988
3989 void dlm_recover_waiters_pre(struct dlm_ls *ls)
3990 {
3991 struct dlm_lkb *lkb, *safe;
3992 int wait_type, stub_unlock_result, stub_cancel_result;
3993
3994 mutex_lock(&ls->ls_waiters_mutex);
3995
3996 list_for_each_entry_safe(lkb, safe, &ls->ls_waiters, lkb_wait_reply) {
3997 log_debug(ls, "pre recover waiter lkid %x type %d flags %x",
3998 lkb->lkb_id, lkb->lkb_wait_type, lkb->lkb_flags);
3999
4000 /* all outstanding lookups, regardless of destination will be
4001 resent after recovery is done */
4002
4003 if (lkb->lkb_wait_type == DLM_MSG_LOOKUP) {
4004 lkb->lkb_flags |= DLM_IFL_RESEND;
4005 continue;
4006 }
4007
4008 if (!waiter_needs_recovery(ls, lkb))
4009 continue;
4010
4011 wait_type = lkb->lkb_wait_type;
4012 stub_unlock_result = -DLM_EUNLOCK;
4013 stub_cancel_result = -DLM_ECANCEL;
4014
4015 /* Main reply may have been received leaving a zero wait_type,
4016 but a reply for the overlapping op may not have been
4017 received. In that case we need to fake the appropriate
4018 reply for the overlap op. */
4019
4020 if (!wait_type) {
4021 if (is_overlap_cancel(lkb)) {
4022 wait_type = DLM_MSG_CANCEL;
4023 if (lkb->lkb_grmode == DLM_LOCK_IV)
4024 stub_cancel_result = 0;
4025 }
4026 if (is_overlap_unlock(lkb)) {
4027 wait_type = DLM_MSG_UNLOCK;
4028 if (lkb->lkb_grmode == DLM_LOCK_IV)
4029 stub_unlock_result = -ENOENT;
4030 }
4031
4032 log_debug(ls, "rwpre overlap %x %x %d %d %d",
4033 lkb->lkb_id, lkb->lkb_flags, wait_type,
4034 stub_cancel_result, stub_unlock_result);
4035 }
4036
4037 switch (wait_type) {
4038
4039 case DLM_MSG_REQUEST:
4040 lkb->lkb_flags |= DLM_IFL_RESEND;
4041 break;
4042
4043 case DLM_MSG_CONVERT:
4044 recover_convert_waiter(ls, lkb);
4045 break;
4046
4047 case DLM_MSG_UNLOCK:
4048 hold_lkb(lkb);
4049 ls->ls_stub_ms.m_type = DLM_MSG_UNLOCK_REPLY;
4050 ls->ls_stub_ms.m_result = stub_unlock_result;
4051 ls->ls_stub_ms.m_flags = lkb->lkb_flags;
4052 ls->ls_stub_ms.m_header.h_nodeid = lkb->lkb_nodeid;
4053 _receive_unlock_reply(lkb, &ls->ls_stub_ms);
4054 dlm_put_lkb(lkb);
4055 break;
4056
4057 case DLM_MSG_CANCEL:
4058 hold_lkb(lkb);
4059 ls->ls_stub_ms.m_type = DLM_MSG_CANCEL_REPLY;
4060 ls->ls_stub_ms.m_result = stub_cancel_result;
4061 ls->ls_stub_ms.m_flags = lkb->lkb_flags;
4062 ls->ls_stub_ms.m_header.h_nodeid = lkb->lkb_nodeid;
4063 _receive_cancel_reply(lkb, &ls->ls_stub_ms);
4064 dlm_put_lkb(lkb);
4065 break;
4066
4067 default:
4068 log_error(ls, "invalid lkb wait_type %d %d",
4069 lkb->lkb_wait_type, wait_type);
4070 }
4071 schedule();
4072 }
4073 mutex_unlock(&ls->ls_waiters_mutex);
4074 }
4075
4076 static struct dlm_lkb *find_resend_waiter(struct dlm_ls *ls)
4077 {
4078 struct dlm_lkb *lkb;
4079 int found = 0;
4080
4081 mutex_lock(&ls->ls_waiters_mutex);
4082 list_for_each_entry(lkb, &ls->ls_waiters, lkb_wait_reply) {
4083 if (lkb->lkb_flags & DLM_IFL_RESEND) {
4084 hold_lkb(lkb);
4085 found = 1;
4086 break;
4087 }
4088 }
4089 mutex_unlock(&ls->ls_waiters_mutex);
4090
4091 if (!found)
4092 lkb = NULL;
4093 return lkb;
4094 }
4095
4096 /* Deal with lookups and lkb's marked RESEND from _pre. We may now be the
4097 master or dir-node for r. Processing the lkb may result in it being placed
4098 back on waiters. */
4099
4100 /* We do this after normal locking has been enabled and any saved messages
4101 (in requestqueue) have been processed. We should be confident that at
4102 this point we won't get or process a reply to any of these waiting
4103 operations. But, new ops may be coming in on the rsbs/locks here from
4104 userspace or remotely. */
4105
4106 /* there may have been an overlap unlock/cancel prior to recovery or after
4107 recovery. if before, the lkb may still have a pos wait_count; if after, the
4108 overlap flag would just have been set and nothing new sent. we can be
4109 confident here than any replies to either the initial op or overlap ops
4110 prior to recovery have been received. */
4111
4112 int dlm_recover_waiters_post(struct dlm_ls *ls)
4113 {
4114 struct dlm_lkb *lkb;
4115 struct dlm_rsb *r;
4116 int error = 0, mstype, err, oc, ou;
4117
4118 while (1) {
4119 if (dlm_locking_stopped(ls)) {
4120 log_debug(ls, "recover_waiters_post aborted");
4121 error = -EINTR;
4122 break;
4123 }
4124
4125 lkb = find_resend_waiter(ls);
4126 if (!lkb)
4127 break;
4128
4129 r = lkb->lkb_resource;
4130 hold_rsb(r);
4131 lock_rsb(r);
4132
4133 mstype = lkb->lkb_wait_type;
4134 oc = is_overlap_cancel(lkb);
4135 ou = is_overlap_unlock(lkb);
4136 err = 0;
4137
4138 log_debug(ls, "recover_waiters_post %x type %d flags %x %s",
4139 lkb->lkb_id, mstype, lkb->lkb_flags, r->res_name);
4140
4141 /* At this point we assume that we won't get a reply to any
4142 previous op or overlap op on this lock. First, do a big
4143 remove_from_waiters() for all previous ops. */
4144
4145 lkb->lkb_flags &= ~DLM_IFL_RESEND;
4146 lkb->lkb_flags &= ~DLM_IFL_OVERLAP_UNLOCK;
4147 lkb->lkb_flags &= ~DLM_IFL_OVERLAP_CANCEL;
4148 lkb->lkb_wait_type = 0;
4149 lkb->lkb_wait_count = 0;
4150 mutex_lock(&ls->ls_waiters_mutex);
4151 list_del_init(&lkb->lkb_wait_reply);
4152 mutex_unlock(&ls->ls_waiters_mutex);
4153 unhold_lkb(lkb); /* for waiters list */
4154
4155 if (oc || ou) {
4156 /* do an unlock or cancel instead of resending */
4157 switch (mstype) {
4158 case DLM_MSG_LOOKUP:
4159 case DLM_MSG_REQUEST:
4160 queue_cast(r, lkb, ou ? -DLM_EUNLOCK :
4161 -DLM_ECANCEL);
4162 unhold_lkb(lkb); /* undoes create_lkb() */
4163 break;
4164 case DLM_MSG_CONVERT:
4165 if (oc) {
4166 queue_cast(r, lkb, -DLM_ECANCEL);
4167 } else {
4168 lkb->lkb_exflags |= DLM_LKF_FORCEUNLOCK;
4169 _unlock_lock(r, lkb);
4170 }
4171 break;
4172 default:
4173 err = 1;
4174 }
4175 } else {
4176 switch (mstype) {
4177 case DLM_MSG_LOOKUP:
4178 case DLM_MSG_REQUEST:
4179 _request_lock(r, lkb);
4180 if (is_master(r))
4181 confirm_master(r, 0);
4182 break;
4183 case DLM_MSG_CONVERT:
4184 _convert_lock(r, lkb);
4185 break;
4186 default:
4187 err = 1;
4188 }
4189 }
4190
4191 if (err)
4192 log_error(ls, "recover_waiters_post %x %d %x %d %d",
4193 lkb->lkb_id, mstype, lkb->lkb_flags, oc, ou);
4194 unlock_rsb(r);
4195 put_rsb(r);
4196 dlm_put_lkb(lkb);
4197 }
4198
4199 return error;
4200 }
4201
4202 static void purge_queue(struct dlm_rsb *r, struct list_head *queue,
4203 int (*test)(struct dlm_ls *ls, struct dlm_lkb *lkb))
4204 {
4205 struct dlm_ls *ls = r->res_ls;
4206 struct dlm_lkb *lkb, *safe;
4207
4208 list_for_each_entry_safe(lkb, safe, queue, lkb_statequeue) {
4209 if (test(ls, lkb)) {
4210 rsb_set_flag(r, RSB_LOCKS_PURGED);
4211 del_lkb(r, lkb);
4212 /* this put should free the lkb */
4213 if (!dlm_put_lkb(lkb))
4214 log_error(ls, "purged lkb not released");
4215 }
4216 }
4217 }
4218
4219 static int purge_dead_test(struct dlm_ls *ls, struct dlm_lkb *lkb)
4220 {
4221 return (is_master_copy(lkb) && dlm_is_removed(ls, lkb->lkb_nodeid));
4222 }
4223
4224 static int purge_mstcpy_test(struct dlm_ls *ls, struct dlm_lkb *lkb)
4225 {
4226 return is_master_copy(lkb);
4227 }
4228
4229 static void purge_dead_locks(struct dlm_rsb *r)
4230 {
4231 purge_queue(r, &r->res_grantqueue, &purge_dead_test);
4232 purge_queue(r, &r->res_convertqueue, &purge_dead_test);
4233 purge_queue(r, &r->res_waitqueue, &purge_dead_test);
4234 }
4235
4236 void dlm_purge_mstcpy_locks(struct dlm_rsb *r)
4237 {
4238 purge_queue(r, &r->res_grantqueue, &purge_mstcpy_test);
4239 purge_queue(r, &r->res_convertqueue, &purge_mstcpy_test);
4240 purge_queue(r, &r->res_waitqueue, &purge_mstcpy_test);
4241 }
4242
4243 /* Get rid of locks held by nodes that are gone. */
4244
4245 int dlm_purge_locks(struct dlm_ls *ls)
4246 {
4247 struct dlm_rsb *r;
4248
4249 log_debug(ls, "dlm_purge_locks");
4250
4251 down_write(&ls->ls_root_sem);
4252 list_for_each_entry(r, &ls->ls_root_list, res_root_list) {
4253 hold_rsb(r);
4254 lock_rsb(r);
4255 if (is_master(r))
4256 purge_dead_locks(r);
4257 unlock_rsb(r);
4258 unhold_rsb(r);
4259
4260 schedule();
4261 }
4262 up_write(&ls->ls_root_sem);
4263
4264 return 0;
4265 }
4266
4267 static struct dlm_rsb *find_purged_rsb(struct dlm_ls *ls, int bucket)
4268 {
4269 struct dlm_rsb *r, *r_ret = NULL;
4270
4271 spin_lock(&ls->ls_rsbtbl[bucket].lock);
4272 list_for_each_entry(r, &ls->ls_rsbtbl[bucket].list, res_hashchain) {
4273 if (!rsb_flag(r, RSB_LOCKS_PURGED))
4274 continue;
4275 hold_rsb(r);
4276 rsb_clear_flag(r, RSB_LOCKS_PURGED);
4277 r_ret = r;
4278 break;
4279 }
4280 spin_unlock(&ls->ls_rsbtbl[bucket].lock);
4281 return r_ret;
4282 }
4283
4284 void dlm_grant_after_purge(struct dlm_ls *ls)
4285 {
4286 struct dlm_rsb *r;
4287 int bucket = 0;
4288
4289 while (1) {
4290 r = find_purged_rsb(ls, bucket);
4291 if (!r) {
4292 if (bucket == ls->ls_rsbtbl_size - 1)
4293 break;
4294 bucket++;
4295 continue;
4296 }
4297 lock_rsb(r);
4298 if (is_master(r)) {
4299 grant_pending_locks(r);
4300 confirm_master(r, 0);
4301 }
4302 unlock_rsb(r);
4303 put_rsb(r);
4304 schedule();
4305 }
4306 }
4307
4308 static struct dlm_lkb *search_remid_list(struct list_head *head, int nodeid,
4309 uint32_t remid)
4310 {
4311 struct dlm_lkb *lkb;
4312
4313 list_for_each_entry(lkb, head, lkb_statequeue) {
4314 if (lkb->lkb_nodeid == nodeid && lkb->lkb_remid == remid)
4315 return lkb;
4316 }
4317 return NULL;
4318 }
4319
4320 static struct dlm_lkb *search_remid(struct dlm_rsb *r, int nodeid,
4321 uint32_t remid)
4322 {
4323 struct dlm_lkb *lkb;
4324
4325 lkb = search_remid_list(&r->res_grantqueue, nodeid, remid);
4326 if (lkb)
4327 return lkb;
4328 lkb = search_remid_list(&r->res_convertqueue, nodeid, remid);
4329 if (lkb)
4330 return lkb;
4331 lkb = search_remid_list(&r->res_waitqueue, nodeid, remid);
4332 if (lkb)
4333 return lkb;
4334 return NULL;
4335 }
4336
4337 /* needs at least dlm_rcom + rcom_lock */
4338 static int receive_rcom_lock_args(struct dlm_ls *ls, struct dlm_lkb *lkb,
4339 struct dlm_rsb *r, struct dlm_rcom *rc)
4340 {
4341 struct rcom_lock *rl = (struct rcom_lock *) rc->rc_buf;
4342
4343 lkb->lkb_nodeid = rc->rc_header.h_nodeid;
4344 lkb->lkb_ownpid = le32_to_cpu(rl->rl_ownpid);
4345 lkb->lkb_remid = le32_to_cpu(rl->rl_lkid);
4346 lkb->lkb_exflags = le32_to_cpu(rl->rl_exflags);
4347 lkb->lkb_flags = le32_to_cpu(rl->rl_flags) & 0x0000FFFF;
4348 lkb->lkb_flags |= DLM_IFL_MSTCPY;
4349 lkb->lkb_lvbseq = le32_to_cpu(rl->rl_lvbseq);
4350 lkb->lkb_rqmode = rl->rl_rqmode;
4351 lkb->lkb_grmode = rl->rl_grmode;
4352 /* don't set lkb_status because add_lkb wants to itself */
4353
4354 lkb->lkb_bastfn = (rl->rl_asts & AST_BAST) ? &fake_bastfn : NULL;
4355 lkb->lkb_astfn = (rl->rl_asts & AST_COMP) ? &fake_astfn : NULL;
4356
4357 if (lkb->lkb_exflags & DLM_LKF_VALBLK) {
4358 int lvblen = rc->rc_header.h_length - sizeof(struct dlm_rcom) -
4359 sizeof(struct rcom_lock);
4360 if (lvblen > ls->ls_lvblen)
4361 return -EINVAL;
4362 lkb->lkb_lvbptr = dlm_allocate_lv