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1 /******************************************************************************
2 *******************************************************************************
3 **
4 ** Copyright (C) 2005-2010 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 <linux/rbtree.h>
60 #include <linux/slab.h>
61 #include "dlm_internal.h"
62 #include <linux/dlm_device.h>
63 #include "memory.h"
64 #include "lowcomms.h"
65 #include "requestqueue.h"
66 #include "util.h"
67 #include "dir.h"
68 #include "member.h"
69 #include "lockspace.h"
70 #include "ast.h"
71 #include "lock.h"
72 #include "rcom.h"
73 #include "recover.h"
74 #include "lvb_table.h"
75 #include "user.h"
76 #include "config.h"
77
78 static int send_request(struct dlm_rsb *r, struct dlm_lkb *lkb);
79 static int send_convert(struct dlm_rsb *r, struct dlm_lkb *lkb);
80 static int send_unlock(struct dlm_rsb *r, struct dlm_lkb *lkb);
81 static int send_cancel(struct dlm_rsb *r, struct dlm_lkb *lkb);
82 static int send_grant(struct dlm_rsb *r, struct dlm_lkb *lkb);
83 static int send_bast(struct dlm_rsb *r, struct dlm_lkb *lkb, int mode);
84 static int send_lookup(struct dlm_rsb *r, struct dlm_lkb *lkb);
85 static int send_remove(struct dlm_rsb *r);
86 static int _request_lock(struct dlm_rsb *r, struct dlm_lkb *lkb);
87 static int _cancel_lock(struct dlm_rsb *r, struct dlm_lkb *lkb);
88 static void __receive_convert_reply(struct dlm_rsb *r, struct dlm_lkb *lkb,
89 struct dlm_message *ms);
90 static int receive_extralen(struct dlm_message *ms);
91 static void do_purge(struct dlm_ls *ls, int nodeid, int pid);
92 static void del_timeout(struct dlm_lkb *lkb);
93 static void toss_rsb(struct kref *kref);
94
95 /*
96 * Lock compatibilty matrix - thanks Steve
97 * UN = Unlocked state. Not really a state, used as a flag
98 * PD = Padding. Used to make the matrix a nice power of two in size
99 * Other states are the same as the VMS DLM.
100 * Usage: matrix[grmode+1][rqmode+1] (although m[rq+1][gr+1] is the same)
101 */
102
103 static const int __dlm_compat_matrix[8][8] = {
104 /* UN NL CR CW PR PW EX PD */
105 {1, 1, 1, 1, 1, 1, 1, 0}, /* UN */
106 {1, 1, 1, 1, 1, 1, 1, 0}, /* NL */
107 {1, 1, 1, 1, 1, 1, 0, 0}, /* CR */
108 {1, 1, 1, 1, 0, 0, 0, 0}, /* CW */
109 {1, 1, 1, 0, 1, 0, 0, 0}, /* PR */
110 {1, 1, 1, 0, 0, 0, 0, 0}, /* PW */
111 {1, 1, 0, 0, 0, 0, 0, 0}, /* EX */
112 {0, 0, 0, 0, 0, 0, 0, 0} /* PD */
113 };
114
115 /*
116 * This defines the direction of transfer of LVB data.
117 * Granted mode is the row; requested mode is the column.
118 * Usage: matrix[grmode+1][rqmode+1]
119 * 1 = LVB is returned to the caller
120 * 0 = LVB is written to the resource
121 * -1 = nothing happens to the LVB
122 */
123
124 const int dlm_lvb_operations[8][8] = {
125 /* UN NL CR CW PR PW EX PD*/
126 { -1, 1, 1, 1, 1, 1, 1, -1 }, /* UN */
127 { -1, 1, 1, 1, 1, 1, 1, 0 }, /* NL */
128 { -1, -1, 1, 1, 1, 1, 1, 0 }, /* CR */
129 { -1, -1, -1, 1, 1, 1, 1, 0 }, /* CW */
130 { -1, -1, -1, -1, 1, 1, 1, 0 }, /* PR */
131 { -1, 0, 0, 0, 0, 0, 1, 0 }, /* PW */
132 { -1, 0, 0, 0, 0, 0, 0, 0 }, /* EX */
133 { -1, 0, 0, 0, 0, 0, 0, 0 } /* PD */
134 };
135
136 #define modes_compat(gr, rq) \
137 __dlm_compat_matrix[(gr)->lkb_grmode + 1][(rq)->lkb_rqmode + 1]
138
139 int dlm_modes_compat(int mode1, int mode2)
140 {
141 return __dlm_compat_matrix[mode1 + 1][mode2 + 1];
142 }
143
144 /*
145 * Compatibility matrix for conversions with QUECVT set.
146 * Granted mode is the row; requested mode is the column.
147 * Usage: matrix[grmode+1][rqmode+1]
148 */
149
150 static const int __quecvt_compat_matrix[8][8] = {
151 /* UN NL CR CW PR PW EX PD */
152 {0, 0, 0, 0, 0, 0, 0, 0}, /* UN */
153 {0, 0, 1, 1, 1, 1, 1, 0}, /* NL */
154 {0, 0, 0, 1, 1, 1, 1, 0}, /* CR */
155 {0, 0, 0, 0, 1, 1, 1, 0}, /* CW */
156 {0, 0, 0, 1, 0, 1, 1, 0}, /* PR */
157 {0, 0, 0, 0, 0, 0, 1, 0}, /* PW */
158 {0, 0, 0, 0, 0, 0, 0, 0}, /* EX */
159 {0, 0, 0, 0, 0, 0, 0, 0} /* PD */
160 };
161
162 void dlm_print_lkb(struct dlm_lkb *lkb)
163 {
164 printk(KERN_ERR "lkb: nodeid %d id %x remid %x exflags %x flags %x "
165 "sts %d rq %d gr %d wait_type %d wait_nodeid %d seq %llu\n",
166 lkb->lkb_nodeid, lkb->lkb_id, lkb->lkb_remid, lkb->lkb_exflags,
167 lkb->lkb_flags, lkb->lkb_status, lkb->lkb_rqmode,
168 lkb->lkb_grmode, lkb->lkb_wait_type, lkb->lkb_wait_nodeid,
169 (unsigned long long)lkb->lkb_recover_seq);
170 }
171
172 static void dlm_print_rsb(struct dlm_rsb *r)
173 {
174 printk(KERN_ERR "rsb: nodeid %d master %d dir %d flags %lx first %x "
175 "rlc %d name %s\n",
176 r->res_nodeid, r->res_master_nodeid, r->res_dir_nodeid,
177 r->res_flags, r->res_first_lkid, r->res_recover_locks_count,
178 r->res_name);
179 }
180
181 void dlm_dump_rsb(struct dlm_rsb *r)
182 {
183 struct dlm_lkb *lkb;
184
185 dlm_print_rsb(r);
186
187 printk(KERN_ERR "rsb: root_list empty %d recover_list empty %d\n",
188 list_empty(&r->res_root_list), list_empty(&r->res_recover_list));
189 printk(KERN_ERR "rsb lookup list\n");
190 list_for_each_entry(lkb, &r->res_lookup, lkb_rsb_lookup)
191 dlm_print_lkb(lkb);
192 printk(KERN_ERR "rsb grant queue:\n");
193 list_for_each_entry(lkb, &r->res_grantqueue, lkb_statequeue)
194 dlm_print_lkb(lkb);
195 printk(KERN_ERR "rsb convert queue:\n");
196 list_for_each_entry(lkb, &r->res_convertqueue, lkb_statequeue)
197 dlm_print_lkb(lkb);
198 printk(KERN_ERR "rsb wait queue:\n");
199 list_for_each_entry(lkb, &r->res_waitqueue, lkb_statequeue)
200 dlm_print_lkb(lkb);
201 }
202
203 /* Threads cannot use the lockspace while it's being recovered */
204
205 static inline void dlm_lock_recovery(struct dlm_ls *ls)
206 {
207 down_read(&ls->ls_in_recovery);
208 }
209
210 void dlm_unlock_recovery(struct dlm_ls *ls)
211 {
212 up_read(&ls->ls_in_recovery);
213 }
214
215 int dlm_lock_recovery_try(struct dlm_ls *ls)
216 {
217 return down_read_trylock(&ls->ls_in_recovery);
218 }
219
220 static inline int can_be_queued(struct dlm_lkb *lkb)
221 {
222 return !(lkb->lkb_exflags & DLM_LKF_NOQUEUE);
223 }
224
225 static inline int force_blocking_asts(struct dlm_lkb *lkb)
226 {
227 return (lkb->lkb_exflags & DLM_LKF_NOQUEUEBAST);
228 }
229
230 static inline int is_demoted(struct dlm_lkb *lkb)
231 {
232 return (lkb->lkb_sbflags & DLM_SBF_DEMOTED);
233 }
234
235 static inline int is_altmode(struct dlm_lkb *lkb)
236 {
237 return (lkb->lkb_sbflags & DLM_SBF_ALTMODE);
238 }
239
240 static inline int is_granted(struct dlm_lkb *lkb)
241 {
242 return (lkb->lkb_status == DLM_LKSTS_GRANTED);
243 }
244
245 static inline int is_remote(struct dlm_rsb *r)
246 {
247 DLM_ASSERT(r->res_nodeid >= 0, dlm_print_rsb(r););
248 return !!r->res_nodeid;
249 }
250
251 static inline int is_process_copy(struct dlm_lkb *lkb)
252 {
253 return (lkb->lkb_nodeid && !(lkb->lkb_flags & DLM_IFL_MSTCPY));
254 }
255
256 static inline int is_master_copy(struct dlm_lkb *lkb)
257 {
258 return (lkb->lkb_flags & DLM_IFL_MSTCPY) ? 1 : 0;
259 }
260
261 static inline int middle_conversion(struct dlm_lkb *lkb)
262 {
263 if ((lkb->lkb_grmode==DLM_LOCK_PR && lkb->lkb_rqmode==DLM_LOCK_CW) ||
264 (lkb->lkb_rqmode==DLM_LOCK_PR && lkb->lkb_grmode==DLM_LOCK_CW))
265 return 1;
266 return 0;
267 }
268
269 static inline int down_conversion(struct dlm_lkb *lkb)
270 {
271 return (!middle_conversion(lkb) && lkb->lkb_rqmode < lkb->lkb_grmode);
272 }
273
274 static inline int is_overlap_unlock(struct dlm_lkb *lkb)
275 {
276 return lkb->lkb_flags & DLM_IFL_OVERLAP_UNLOCK;
277 }
278
279 static inline int is_overlap_cancel(struct dlm_lkb *lkb)
280 {
281 return lkb->lkb_flags & DLM_IFL_OVERLAP_CANCEL;
282 }
283
284 static inline int is_overlap(struct dlm_lkb *lkb)
285 {
286 return (lkb->lkb_flags & (DLM_IFL_OVERLAP_UNLOCK |
287 DLM_IFL_OVERLAP_CANCEL));
288 }
289
290 static void queue_cast(struct dlm_rsb *r, struct dlm_lkb *lkb, int rv)
291 {
292 if (is_master_copy(lkb))
293 return;
294
295 del_timeout(lkb);
296
297 DLM_ASSERT(lkb->lkb_lksb, dlm_print_lkb(lkb););
298
299 /* if the operation was a cancel, then return -DLM_ECANCEL, if a
300 timeout caused the cancel then return -ETIMEDOUT */
301 if (rv == -DLM_ECANCEL && (lkb->lkb_flags & DLM_IFL_TIMEOUT_CANCEL)) {
302 lkb->lkb_flags &= ~DLM_IFL_TIMEOUT_CANCEL;
303 rv = -ETIMEDOUT;
304 }
305
306 if (rv == -DLM_ECANCEL && (lkb->lkb_flags & DLM_IFL_DEADLOCK_CANCEL)) {
307 lkb->lkb_flags &= ~DLM_IFL_DEADLOCK_CANCEL;
308 rv = -EDEADLK;
309 }
310
311 dlm_add_cb(lkb, DLM_CB_CAST, lkb->lkb_grmode, rv, lkb->lkb_sbflags);
312 }
313
314 static inline void queue_cast_overlap(struct dlm_rsb *r, struct dlm_lkb *lkb)
315 {
316 queue_cast(r, lkb,
317 is_overlap_unlock(lkb) ? -DLM_EUNLOCK : -DLM_ECANCEL);
318 }
319
320 static void queue_bast(struct dlm_rsb *r, struct dlm_lkb *lkb, int rqmode)
321 {
322 if (is_master_copy(lkb)) {
323 send_bast(r, lkb, rqmode);
324 } else {
325 dlm_add_cb(lkb, DLM_CB_BAST, rqmode, 0, 0);
326 }
327 }
328
329 /*
330 * Basic operations on rsb's and lkb's
331 */
332
333 /* This is only called to add a reference when the code already holds
334 a valid reference to the rsb, so there's no need for locking. */
335
336 static inline void hold_rsb(struct dlm_rsb *r)
337 {
338 kref_get(&r->res_ref);
339 }
340
341 void dlm_hold_rsb(struct dlm_rsb *r)
342 {
343 hold_rsb(r);
344 }
345
346 /* When all references to the rsb are gone it's transferred to
347 the tossed list for later disposal. */
348
349 static void put_rsb(struct dlm_rsb *r)
350 {
351 struct dlm_ls *ls = r->res_ls;
352 uint32_t bucket = r->res_bucket;
353
354 spin_lock(&ls->ls_rsbtbl[bucket].lock);
355 kref_put(&r->res_ref, toss_rsb);
356 spin_unlock(&ls->ls_rsbtbl[bucket].lock);
357 }
358
359 void dlm_put_rsb(struct dlm_rsb *r)
360 {
361 put_rsb(r);
362 }
363
364 static int pre_rsb_struct(struct dlm_ls *ls)
365 {
366 struct dlm_rsb *r1, *r2;
367 int count = 0;
368
369 spin_lock(&ls->ls_new_rsb_spin);
370 if (ls->ls_new_rsb_count > dlm_config.ci_new_rsb_count / 2) {
371 spin_unlock(&ls->ls_new_rsb_spin);
372 return 0;
373 }
374 spin_unlock(&ls->ls_new_rsb_spin);
375
376 r1 = dlm_allocate_rsb(ls);
377 r2 = dlm_allocate_rsb(ls);
378
379 spin_lock(&ls->ls_new_rsb_spin);
380 if (r1) {
381 list_add(&r1->res_hashchain, &ls->ls_new_rsb);
382 ls->ls_new_rsb_count++;
383 }
384 if (r2) {
385 list_add(&r2->res_hashchain, &ls->ls_new_rsb);
386 ls->ls_new_rsb_count++;
387 }
388 count = ls->ls_new_rsb_count;
389 spin_unlock(&ls->ls_new_rsb_spin);
390
391 if (!count)
392 return -ENOMEM;
393 return 0;
394 }
395
396 /* If ls->ls_new_rsb is empty, return -EAGAIN, so the caller can
397 unlock any spinlocks, go back and call pre_rsb_struct again.
398 Otherwise, take an rsb off the list and return it. */
399
400 static int get_rsb_struct(struct dlm_ls *ls, char *name, int len,
401 struct dlm_rsb **r_ret)
402 {
403 struct dlm_rsb *r;
404 int count;
405
406 spin_lock(&ls->ls_new_rsb_spin);
407 if (list_empty(&ls->ls_new_rsb)) {
408 count = ls->ls_new_rsb_count;
409 spin_unlock(&ls->ls_new_rsb_spin);
410 log_debug(ls, "find_rsb retry %d %d %s",
411 count, dlm_config.ci_new_rsb_count, name);
412 return -EAGAIN;
413 }
414
415 r = list_first_entry(&ls->ls_new_rsb, struct dlm_rsb, res_hashchain);
416 list_del(&r->res_hashchain);
417 /* Convert the empty list_head to a NULL rb_node for tree usage: */
418 memset(&r->res_hashnode, 0, sizeof(struct rb_node));
419 ls->ls_new_rsb_count--;
420 spin_unlock(&ls->ls_new_rsb_spin);
421
422 r->res_ls = ls;
423 r->res_length = len;
424 memcpy(r->res_name, name, len);
425 mutex_init(&r->res_mutex);
426
427 INIT_LIST_HEAD(&r->res_lookup);
428 INIT_LIST_HEAD(&r->res_grantqueue);
429 INIT_LIST_HEAD(&r->res_convertqueue);
430 INIT_LIST_HEAD(&r->res_waitqueue);
431 INIT_LIST_HEAD(&r->res_root_list);
432 INIT_LIST_HEAD(&r->res_recover_list);
433
434 *r_ret = r;
435 return 0;
436 }
437
438 static int rsb_cmp(struct dlm_rsb *r, const char *name, int nlen)
439 {
440 char maxname[DLM_RESNAME_MAXLEN];
441
442 memset(maxname, 0, DLM_RESNAME_MAXLEN);
443 memcpy(maxname, name, nlen);
444 return memcmp(r->res_name, maxname, DLM_RESNAME_MAXLEN);
445 }
446
447 int dlm_search_rsb_tree(struct rb_root *tree, char *name, int len,
448 struct dlm_rsb **r_ret)
449 {
450 struct rb_node *node = tree->rb_node;
451 struct dlm_rsb *r;
452 int rc;
453
454 while (node) {
455 r = rb_entry(node, struct dlm_rsb, res_hashnode);
456 rc = rsb_cmp(r, name, len);
457 if (rc < 0)
458 node = node->rb_left;
459 else if (rc > 0)
460 node = node->rb_right;
461 else
462 goto found;
463 }
464 *r_ret = NULL;
465 return -EBADR;
466
467 found:
468 *r_ret = r;
469 return 0;
470 }
471
472 static int rsb_insert(struct dlm_rsb *rsb, struct rb_root *tree)
473 {
474 struct rb_node **newn = &tree->rb_node;
475 struct rb_node *parent = NULL;
476 int rc;
477
478 while (*newn) {
479 struct dlm_rsb *cur = rb_entry(*newn, struct dlm_rsb,
480 res_hashnode);
481
482 parent = *newn;
483 rc = rsb_cmp(cur, rsb->res_name, rsb->res_length);
484 if (rc < 0)
485 newn = &parent->rb_left;
486 else if (rc > 0)
487 newn = &parent->rb_right;
488 else {
489 log_print("rsb_insert match");
490 dlm_dump_rsb(rsb);
491 dlm_dump_rsb(cur);
492 return -EEXIST;
493 }
494 }
495
496 rb_link_node(&rsb->res_hashnode, parent, newn);
497 rb_insert_color(&rsb->res_hashnode, tree);
498 return 0;
499 }
500
501 /*
502 * Find rsb in rsbtbl and potentially create/add one
503 *
504 * Delaying the release of rsb's has a similar benefit to applications keeping
505 * NL locks on an rsb, but without the guarantee that the cached master value
506 * will still be valid when the rsb is reused. Apps aren't always smart enough
507 * to keep NL locks on an rsb that they may lock again shortly; this can lead
508 * to excessive master lookups and removals if we don't delay the release.
509 *
510 * Searching for an rsb means looking through both the normal list and toss
511 * list. When found on the toss list the rsb is moved to the normal list with
512 * ref count of 1; when found on normal list the ref count is incremented.
513 *
514 * rsb's on the keep list are being used locally and refcounted.
515 * rsb's on the toss list are not being used locally, and are not refcounted.
516 *
517 * The toss list rsb's were either
518 * - previously used locally but not any more (were on keep list, then
519 * moved to toss list when last refcount dropped)
520 * - created and put on toss list as a directory record for a lookup
521 * (we are the dir node for the res, but are not using the res right now,
522 * but some other node is)
523 *
524 * The purpose of find_rsb() is to return a refcounted rsb for local use.
525 * So, if the given rsb is on the toss list, it is moved to the keep list
526 * before being returned.
527 *
528 * toss_rsb() happens when all local usage of the rsb is done, i.e. no
529 * more refcounts exist, so the rsb is moved from the keep list to the
530 * toss list.
531 *
532 * rsb's on both keep and toss lists are used for doing a name to master
533 * lookups. rsb's that are in use locally (and being refcounted) are on
534 * the keep list, rsb's that are not in use locally (not refcounted) and
535 * only exist for name/master lookups are on the toss list.
536 *
537 * rsb's on the toss list who's dir_nodeid is not local can have stale
538 * name/master mappings. So, remote requests on such rsb's can potentially
539 * return with an error, which means the mapping is stale and needs to
540 * be updated with a new lookup. (The idea behind MASTER UNCERTAIN and
541 * first_lkid is to keep only a single outstanding request on an rsb
542 * while that rsb has a potentially stale master.)
543 */
544
545 static int find_rsb_dir(struct dlm_ls *ls, char *name, int len,
546 uint32_t hash, uint32_t b,
547 int dir_nodeid, int from_nodeid,
548 unsigned int flags, struct dlm_rsb **r_ret)
549 {
550 struct dlm_rsb *r = NULL;
551 int our_nodeid = dlm_our_nodeid();
552 int from_local = 0;
553 int from_other = 0;
554 int from_dir = 0;
555 int create = 0;
556 int error;
557
558 if (flags & R_RECEIVE_REQUEST) {
559 if (from_nodeid == dir_nodeid)
560 from_dir = 1;
561 else
562 from_other = 1;
563 } else if (flags & R_REQUEST) {
564 from_local = 1;
565 }
566
567 /*
568 * flags & R_RECEIVE_RECOVER is from dlm_recover_master_copy, so
569 * from_nodeid has sent us a lock in dlm_recover_locks, believing
570 * we're the new master. Our local recovery may not have set
571 * res_master_nodeid to our_nodeid yet, so allow either. Don't
572 * create the rsb; dlm_recover_process_copy() will handle EBADR
573 * by resending.
574 *
575 * If someone sends us a request, we are the dir node, and we do
576 * not find the rsb anywhere, then recreate it. This happens if
577 * someone sends us a request after we have removed/freed an rsb
578 * from our toss list. (They sent a request instead of lookup
579 * because they are using an rsb from their toss list.)
580 */
581
582 if (from_local || from_dir ||
583 (from_other && (dir_nodeid == our_nodeid))) {
584 create = 1;
585 }
586
587 retry:
588 if (create) {
589 error = pre_rsb_struct(ls);
590 if (error < 0)
591 goto out;
592 }
593
594 spin_lock(&ls->ls_rsbtbl[b].lock);
595
596 error = dlm_search_rsb_tree(&ls->ls_rsbtbl[b].keep, name, len, &r);
597 if (error)
598 goto do_toss;
599
600 /*
601 * rsb is active, so we can't check master_nodeid without lock_rsb.
602 */
603
604 kref_get(&r->res_ref);
605 error = 0;
606 goto out_unlock;
607
608
609 do_toss:
610 error = dlm_search_rsb_tree(&ls->ls_rsbtbl[b].toss, name, len, &r);
611 if (error)
612 goto do_new;
613
614 /*
615 * rsb found inactive (master_nodeid may be out of date unless
616 * we are the dir_nodeid or were the master) No other thread
617 * is using this rsb because it's on the toss list, so we can
618 * look at or update res_master_nodeid without lock_rsb.
619 */
620
621 if ((r->res_master_nodeid != our_nodeid) && from_other) {
622 /* our rsb was not master, and another node (not the dir node)
623 has sent us a request */
624 log_debug(ls, "find_rsb toss from_other %d master %d dir %d %s",
625 from_nodeid, r->res_master_nodeid, dir_nodeid,
626 r->res_name);
627 error = -ENOTBLK;
628 goto out_unlock;
629 }
630
631 if ((r->res_master_nodeid != our_nodeid) && from_dir) {
632 /* don't think this should ever happen */
633 log_error(ls, "find_rsb toss from_dir %d master %d",
634 from_nodeid, r->res_master_nodeid);
635 dlm_print_rsb(r);
636 /* fix it and go on */
637 r->res_master_nodeid = our_nodeid;
638 r->res_nodeid = 0;
639 rsb_clear_flag(r, RSB_MASTER_UNCERTAIN);
640 r->res_first_lkid = 0;
641 }
642
643 if (from_local && (r->res_master_nodeid != our_nodeid)) {
644 /* Because we have held no locks on this rsb,
645 res_master_nodeid could have become stale. */
646 rsb_set_flag(r, RSB_MASTER_UNCERTAIN);
647 r->res_first_lkid = 0;
648 }
649
650 rb_erase(&r->res_hashnode, &ls->ls_rsbtbl[b].toss);
651 error = rsb_insert(r, &ls->ls_rsbtbl[b].keep);
652 goto out_unlock;
653
654
655 do_new:
656 /*
657 * rsb not found
658 */
659
660 if (error == -EBADR && !create)
661 goto out_unlock;
662
663 error = get_rsb_struct(ls, name, len, &r);
664 if (error == -EAGAIN) {
665 spin_unlock(&ls->ls_rsbtbl[b].lock);
666 goto retry;
667 }
668 if (error)
669 goto out_unlock;
670
671 r->res_hash = hash;
672 r->res_bucket = b;
673 r->res_dir_nodeid = dir_nodeid;
674 kref_init(&r->res_ref);
675
676 if (from_dir) {
677 /* want to see how often this happens */
678 log_debug(ls, "find_rsb new from_dir %d recreate %s",
679 from_nodeid, r->res_name);
680 r->res_master_nodeid = our_nodeid;
681 r->res_nodeid = 0;
682 goto out_add;
683 }
684
685 if (from_other && (dir_nodeid != our_nodeid)) {
686 /* should never happen */
687 log_error(ls, "find_rsb new from_other %d dir %d our %d %s",
688 from_nodeid, dir_nodeid, our_nodeid, r->res_name);
689 dlm_free_rsb(r);
690 error = -ENOTBLK;
691 goto out_unlock;
692 }
693
694 if (from_other) {
695 log_debug(ls, "find_rsb new from_other %d dir %d %s",
696 from_nodeid, dir_nodeid, r->res_name);
697 }
698
699 if (dir_nodeid == our_nodeid) {
700 /* When we are the dir nodeid, we can set the master
701 node immediately */
702 r->res_master_nodeid = our_nodeid;
703 r->res_nodeid = 0;
704 } else {
705 /* set_master will send_lookup to dir_nodeid */
706 r->res_master_nodeid = 0;
707 r->res_nodeid = -1;
708 }
709
710 out_add:
711 error = rsb_insert(r, &ls->ls_rsbtbl[b].keep);
712 out_unlock:
713 spin_unlock(&ls->ls_rsbtbl[b].lock);
714 out:
715 *r_ret = r;
716 return error;
717 }
718
719 /* During recovery, other nodes can send us new MSTCPY locks (from
720 dlm_recover_locks) before we've made ourself master (in
721 dlm_recover_masters). */
722
723 static int find_rsb_nodir(struct dlm_ls *ls, char *name, int len,
724 uint32_t hash, uint32_t b,
725 int dir_nodeid, int from_nodeid,
726 unsigned int flags, struct dlm_rsb **r_ret)
727 {
728 struct dlm_rsb *r = NULL;
729 int our_nodeid = dlm_our_nodeid();
730 int recover = (flags & R_RECEIVE_RECOVER);
731 int error;
732
733 retry:
734 error = pre_rsb_struct(ls);
735 if (error < 0)
736 goto out;
737
738 spin_lock(&ls->ls_rsbtbl[b].lock);
739
740 error = dlm_search_rsb_tree(&ls->ls_rsbtbl[b].keep, name, len, &r);
741 if (error)
742 goto do_toss;
743
744 /*
745 * rsb is active, so we can't check master_nodeid without lock_rsb.
746 */
747
748 kref_get(&r->res_ref);
749 goto out_unlock;
750
751
752 do_toss:
753 error = dlm_search_rsb_tree(&ls->ls_rsbtbl[b].toss, name, len, &r);
754 if (error)
755 goto do_new;
756
757 /*
758 * rsb found inactive. No other thread is using this rsb because
759 * it's on the toss list, so we can look at or update
760 * res_master_nodeid without lock_rsb.
761 */
762
763 if (!recover && (r->res_master_nodeid != our_nodeid) && from_nodeid) {
764 /* our rsb is not master, and another node has sent us a
765 request; this should never happen */
766 log_error(ls, "find_rsb toss from_nodeid %d master %d dir %d",
767 from_nodeid, r->res_master_nodeid, dir_nodeid);
768 dlm_print_rsb(r);
769 error = -ENOTBLK;
770 goto out_unlock;
771 }
772
773 if (!recover && (r->res_master_nodeid != our_nodeid) &&
774 (dir_nodeid == our_nodeid)) {
775 /* our rsb is not master, and we are dir; may as well fix it;
776 this should never happen */
777 log_error(ls, "find_rsb toss our %d master %d dir %d",
778 our_nodeid, r->res_master_nodeid, dir_nodeid);
779 dlm_print_rsb(r);
780 r->res_master_nodeid = our_nodeid;
781 r->res_nodeid = 0;
782 }
783
784 rb_erase(&r->res_hashnode, &ls->ls_rsbtbl[b].toss);
785 error = rsb_insert(r, &ls->ls_rsbtbl[b].keep);
786 goto out_unlock;
787
788
789 do_new:
790 /*
791 * rsb not found
792 */
793
794 error = get_rsb_struct(ls, name, len, &r);
795 if (error == -EAGAIN) {
796 spin_unlock(&ls->ls_rsbtbl[b].lock);
797 goto retry;
798 }
799 if (error)
800 goto out_unlock;
801
802 r->res_hash = hash;
803 r->res_bucket = b;
804 r->res_dir_nodeid = dir_nodeid;
805 r->res_master_nodeid = dir_nodeid;
806 r->res_nodeid = (dir_nodeid == our_nodeid) ? 0 : dir_nodeid;
807 kref_init(&r->res_ref);
808
809 error = rsb_insert(r, &ls->ls_rsbtbl[b].keep);
810 out_unlock:
811 spin_unlock(&ls->ls_rsbtbl[b].lock);
812 out:
813 *r_ret = r;
814 return error;
815 }
816
817 static int find_rsb(struct dlm_ls *ls, char *name, int len, int from_nodeid,
818 unsigned int flags, struct dlm_rsb **r_ret)
819 {
820 uint32_t hash, b;
821 int dir_nodeid;
822
823 if (len > DLM_RESNAME_MAXLEN)
824 return -EINVAL;
825
826 hash = jhash(name, len, 0);
827 b = hash & (ls->ls_rsbtbl_size - 1);
828
829 dir_nodeid = dlm_hash2nodeid(ls, hash);
830
831 if (dlm_no_directory(ls))
832 return find_rsb_nodir(ls, name, len, hash, b, dir_nodeid,
833 from_nodeid, flags, r_ret);
834 else
835 return find_rsb_dir(ls, name, len, hash, b, dir_nodeid,
836 from_nodeid, flags, r_ret);
837 }
838
839 /* we have received a request and found that res_master_nodeid != our_nodeid,
840 so we need to return an error or make ourself the master */
841
842 static int validate_master_nodeid(struct dlm_ls *ls, struct dlm_rsb *r,
843 int from_nodeid)
844 {
845 if (dlm_no_directory(ls)) {
846 log_error(ls, "find_rsb keep from_nodeid %d master %d dir %d",
847 from_nodeid, r->res_master_nodeid,
848 r->res_dir_nodeid);
849 dlm_print_rsb(r);
850 return -ENOTBLK;
851 }
852
853 if (from_nodeid != r->res_dir_nodeid) {
854 /* our rsb is not master, and another node (not the dir node)
855 has sent us a request. this is much more common when our
856 master_nodeid is zero, so limit debug to non-zero. */
857
858 if (r->res_master_nodeid) {
859 log_debug(ls, "validate master from_other %d master %d "
860 "dir %d first %x %s", from_nodeid,
861 r->res_master_nodeid, r->res_dir_nodeid,
862 r->res_first_lkid, r->res_name);
863 }
864 return -ENOTBLK;
865 } else {
866 /* our rsb is not master, but the dir nodeid has sent us a
867 request; this could happen with master 0 / res_nodeid -1 */
868
869 if (r->res_master_nodeid) {
870 log_error(ls, "validate master from_dir %d master %d "
871 "first %x %s",
872 from_nodeid, r->res_master_nodeid,
873 r->res_first_lkid, r->res_name);
874 }
875
876 r->res_master_nodeid = dlm_our_nodeid();
877 r->res_nodeid = 0;
878 return 0;
879 }
880 }
881
882 /*
883 * We're the dir node for this res and another node wants to know the
884 * master nodeid. During normal operation (non recovery) this is only
885 * called from receive_lookup(); master lookups when the local node is
886 * the dir node are done by find_rsb().
887 *
888 * normal operation, we are the dir node for a resource
889 * . _request_lock
890 * . set_master
891 * . send_lookup
892 * . receive_lookup
893 * . dlm_master_lookup flags 0
894 *
895 * recover directory, we are rebuilding dir for all resources
896 * . dlm_recover_directory
897 * . dlm_rcom_names
898 * remote node sends back the rsb names it is master of and we are dir of
899 * . dlm_master_lookup RECOVER_DIR (fix_master 0, from_master 1)
900 * we either create new rsb setting remote node as master, or find existing
901 * rsb and set master to be the remote node.
902 *
903 * recover masters, we are finding the new master for resources
904 * . dlm_recover_masters
905 * . recover_master
906 * . dlm_send_rcom_lookup
907 * . receive_rcom_lookup
908 * . dlm_master_lookup RECOVER_MASTER (fix_master 1, from_master 0)
909 */
910
911 int dlm_master_lookup(struct dlm_ls *ls, int from_nodeid, char *name, int len,
912 unsigned int flags, int *r_nodeid, int *result)
913 {
914 struct dlm_rsb *r = NULL;
915 uint32_t hash, b;
916 int from_master = (flags & DLM_LU_RECOVER_DIR);
917 int fix_master = (flags & DLM_LU_RECOVER_MASTER);
918 int our_nodeid = dlm_our_nodeid();
919 int dir_nodeid, error, toss_list = 0;
920
921 if (len > DLM_RESNAME_MAXLEN)
922 return -EINVAL;
923
924 if (from_nodeid == our_nodeid) {
925 log_error(ls, "dlm_master_lookup from our_nodeid %d flags %x",
926 our_nodeid, flags);
927 return -EINVAL;
928 }
929
930 hash = jhash(name, len, 0);
931 b = hash & (ls->ls_rsbtbl_size - 1);
932
933 dir_nodeid = dlm_hash2nodeid(ls, hash);
934 if (dir_nodeid != our_nodeid) {
935 log_error(ls, "dlm_master_lookup from %d dir %d our %d h %x %d",
936 from_nodeid, dir_nodeid, our_nodeid, hash,
937 ls->ls_num_nodes);
938 *r_nodeid = -1;
939 return -EINVAL;
940 }
941
942 retry:
943 error = pre_rsb_struct(ls);
944 if (error < 0)
945 return error;
946
947 spin_lock(&ls->ls_rsbtbl[b].lock);
948 error = dlm_search_rsb_tree(&ls->ls_rsbtbl[b].keep, name, len, &r);
949 if (!error) {
950 /* because the rsb is active, we need to lock_rsb before
951 checking/changing re_master_nodeid */
952
953 hold_rsb(r);
954 spin_unlock(&ls->ls_rsbtbl[b].lock);
955 lock_rsb(r);
956 goto found;
957 }
958
959 error = dlm_search_rsb_tree(&ls->ls_rsbtbl[b].toss, name, len, &r);
960 if (error)
961 goto not_found;
962
963 /* because the rsb is inactive (on toss list), it's not refcounted
964 and lock_rsb is not used, but is protected by the rsbtbl lock */
965
966 toss_list = 1;
967 found:
968 if (r->res_dir_nodeid != our_nodeid) {
969 /* should not happen, but may as well fix it and carry on */
970 log_error(ls, "dlm_master_lookup res_dir %d our %d %s",
971 r->res_dir_nodeid, our_nodeid, r->res_name);
972 r->res_dir_nodeid = our_nodeid;
973 }
974
975 if (fix_master && dlm_is_removed(ls, r->res_master_nodeid)) {
976 /* Recovery uses this function to set a new master when
977 the previous master failed. Setting NEW_MASTER will
978 force dlm_recover_masters to call recover_master on this
979 rsb even though the res_nodeid is no longer removed. */
980
981 r->res_master_nodeid = from_nodeid;
982 r->res_nodeid = from_nodeid;
983 rsb_set_flag(r, RSB_NEW_MASTER);
984
985 if (toss_list) {
986 /* I don't think we should ever find it on toss list. */
987 log_error(ls, "dlm_master_lookup fix_master on toss");
988 dlm_dump_rsb(r);
989 }
990 }
991
992 if (from_master && (r->res_master_nodeid != from_nodeid)) {
993 /* this will happen if from_nodeid became master during
994 a previous recovery cycle, and we aborted the previous
995 cycle before recovering this master value */
996
997 log_limit(ls, "dlm_master_lookup from_master %d "
998 "master_nodeid %d res_nodeid %d first %x %s",
999 from_nodeid, r->res_master_nodeid, r->res_nodeid,
1000 r->res_first_lkid, r->res_name);
1001
1002 if (r->res_master_nodeid == our_nodeid) {
1003 log_error(ls, "from_master %d our_master", from_nodeid);
1004 dlm_dump_rsb(r);
1005 dlm_send_rcom_lookup_dump(r, from_nodeid);
1006 goto out_found;
1007 }
1008
1009 r->res_master_nodeid = from_nodeid;
1010 r->res_nodeid = from_nodeid;
1011 rsb_set_flag(r, RSB_NEW_MASTER);
1012 }
1013
1014 if (!r->res_master_nodeid) {
1015 /* this will happen if recovery happens while we're looking
1016 up the master for this rsb */
1017
1018 log_debug(ls, "dlm_master_lookup master 0 to %d first %x %s",
1019 from_nodeid, r->res_first_lkid, r->res_name);
1020 r->res_master_nodeid = from_nodeid;
1021 r->res_nodeid = from_nodeid;
1022 }
1023
1024 if (!from_master && !fix_master &&
1025 (r->res_master_nodeid == from_nodeid)) {
1026 /* this can happen when the master sends remove, the dir node
1027 finds the rsb on the keep list and ignores the remove,
1028 and the former master sends a lookup */
1029
1030 log_limit(ls, "dlm_master_lookup from master %d flags %x "
1031 "first %x %s", from_nodeid, flags,
1032 r->res_first_lkid, r->res_name);
1033 }
1034
1035 out_found:
1036 *r_nodeid = r->res_master_nodeid;
1037 if (result)
1038 *result = DLM_LU_MATCH;
1039
1040 if (toss_list) {
1041 r->res_toss_time = jiffies;
1042 /* the rsb was inactive (on toss list) */
1043 spin_unlock(&ls->ls_rsbtbl[b].lock);
1044 } else {
1045 /* the rsb was active */
1046 unlock_rsb(r);
1047 put_rsb(r);
1048 }
1049 return 0;
1050
1051 not_found:
1052 error = get_rsb_struct(ls, name, len, &r);
1053 if (error == -EAGAIN) {
1054 spin_unlock(&ls->ls_rsbtbl[b].lock);
1055 goto retry;
1056 }
1057 if (error)
1058 goto out_unlock;
1059
1060 r->res_hash = hash;
1061 r->res_bucket = b;
1062 r->res_dir_nodeid = our_nodeid;
1063 r->res_master_nodeid = from_nodeid;
1064 r->res_nodeid = from_nodeid;
1065 kref_init(&r->res_ref);
1066 r->res_toss_time = jiffies;
1067
1068 error = rsb_insert(r, &ls->ls_rsbtbl[b].toss);
1069 if (error) {
1070 /* should never happen */
1071 dlm_free_rsb(r);
1072 spin_unlock(&ls->ls_rsbtbl[b].lock);
1073 goto retry;
1074 }
1075
1076 if (result)
1077 *result = DLM_LU_ADD;
1078 *r_nodeid = from_nodeid;
1079 error = 0;
1080 out_unlock:
1081 spin_unlock(&ls->ls_rsbtbl[b].lock);
1082 return error;
1083 }
1084
1085 static void dlm_dump_rsb_hash(struct dlm_ls *ls, uint32_t hash)
1086 {
1087 struct rb_node *n;
1088 struct dlm_rsb *r;
1089 int i;
1090
1091 for (i = 0; i < ls->ls_rsbtbl_size; i++) {
1092 spin_lock(&ls->ls_rsbtbl[i].lock);
1093 for (n = rb_first(&ls->ls_rsbtbl[i].keep); n; n = rb_next(n)) {
1094 r = rb_entry(n, struct dlm_rsb, res_hashnode);
1095 if (r->res_hash == hash)
1096 dlm_dump_rsb(r);
1097 }
1098 spin_unlock(&ls->ls_rsbtbl[i].lock);
1099 }
1100 }
1101
1102 void dlm_dump_rsb_name(struct dlm_ls *ls, char *name, int len)
1103 {
1104 struct dlm_rsb *r = NULL;
1105 uint32_t hash, b;
1106 int error;
1107
1108 hash = jhash(name, len, 0);
1109 b = hash & (ls->ls_rsbtbl_size - 1);
1110
1111 spin_lock(&ls->ls_rsbtbl[b].lock);
1112 error = dlm_search_rsb_tree(&ls->ls_rsbtbl[b].keep, name, len, &r);
1113 if (!error)
1114 goto out_dump;
1115
1116 error = dlm_search_rsb_tree(&ls->ls_rsbtbl[b].toss, name, len, &r);
1117 if (error)
1118 goto out;
1119 out_dump:
1120 dlm_dump_rsb(r);
1121 out:
1122 spin_unlock(&ls->ls_rsbtbl[b].lock);
1123 }
1124
1125 static void toss_rsb(struct kref *kref)
1126 {
1127 struct dlm_rsb *r = container_of(kref, struct dlm_rsb, res_ref);
1128 struct dlm_ls *ls = r->res_ls;
1129
1130 DLM_ASSERT(list_empty(&r->res_root_list), dlm_print_rsb(r););
1131 kref_init(&r->res_ref);
1132 rb_erase(&r->res_hashnode, &ls->ls_rsbtbl[r->res_bucket].keep);
1133 rsb_insert(r, &ls->ls_rsbtbl[r->res_bucket].toss);
1134 r->res_toss_time = jiffies;
1135 if (r->res_lvbptr) {
1136 dlm_free_lvb(r->res_lvbptr);
1137 r->res_lvbptr = NULL;
1138 }
1139 }
1140
1141 /* See comment for unhold_lkb */
1142
1143 static void unhold_rsb(struct dlm_rsb *r)
1144 {
1145 int rv;
1146 rv = kref_put(&r->res_ref, toss_rsb);
1147 DLM_ASSERT(!rv, dlm_dump_rsb(r););
1148 }
1149
1150 static void kill_rsb(struct kref *kref)
1151 {
1152 struct dlm_rsb *r = container_of(kref, struct dlm_rsb, res_ref);
1153
1154 /* All work is done after the return from kref_put() so we
1155 can release the write_lock before the remove and free. */
1156
1157 DLM_ASSERT(list_empty(&r->res_lookup), dlm_dump_rsb(r););
1158 DLM_ASSERT(list_empty(&r->res_grantqueue), dlm_dump_rsb(r););
1159 DLM_ASSERT(list_empty(&r->res_convertqueue), dlm_dump_rsb(r););
1160 DLM_ASSERT(list_empty(&r->res_waitqueue), dlm_dump_rsb(r););
1161 DLM_ASSERT(list_empty(&r->res_root_list), dlm_dump_rsb(r););
1162 DLM_ASSERT(list_empty(&r->res_recover_list), dlm_dump_rsb(r););
1163 }
1164
1165 /* Attaching/detaching lkb's from rsb's is for rsb reference counting.
1166 The rsb must exist as long as any lkb's for it do. */
1167
1168 static void attach_lkb(struct dlm_rsb *r, struct dlm_lkb *lkb)
1169 {
1170 hold_rsb(r);
1171 lkb->lkb_resource = r;
1172 }
1173
1174 static void detach_lkb(struct dlm_lkb *lkb)
1175 {
1176 if (lkb->lkb_resource) {
1177 put_rsb(lkb->lkb_resource);
1178 lkb->lkb_resource = NULL;
1179 }
1180 }
1181
1182 static int create_lkb(struct dlm_ls *ls, struct dlm_lkb **lkb_ret)
1183 {
1184 struct dlm_lkb *lkb;
1185 int rv, id;
1186
1187 lkb = dlm_allocate_lkb(ls);
1188 if (!lkb)
1189 return -ENOMEM;
1190
1191 lkb->lkb_nodeid = -1;
1192 lkb->lkb_grmode = DLM_LOCK_IV;
1193 kref_init(&lkb->lkb_ref);
1194 INIT_LIST_HEAD(&lkb->lkb_ownqueue);
1195 INIT_LIST_HEAD(&lkb->lkb_rsb_lookup);
1196 INIT_LIST_HEAD(&lkb->lkb_time_list);
1197 INIT_LIST_HEAD(&lkb->lkb_cb_list);
1198 mutex_init(&lkb->lkb_cb_mutex);
1199 INIT_WORK(&lkb->lkb_cb_work, dlm_callback_work);
1200
1201 retry:
1202 rv = idr_pre_get(&ls->ls_lkbidr, GFP_NOFS);
1203 if (!rv)
1204 return -ENOMEM;
1205
1206 spin_lock(&ls->ls_lkbidr_spin);
1207 rv = idr_get_new_above(&ls->ls_lkbidr, lkb, 1, &id);
1208 if (!rv)
1209 lkb->lkb_id = id;
1210 spin_unlock(&ls->ls_lkbidr_spin);
1211
1212 if (rv == -EAGAIN)
1213 goto retry;
1214
1215 if (rv < 0) {
1216 log_error(ls, "create_lkb idr error %d", rv);
1217 return rv;
1218 }
1219
1220 *lkb_ret = lkb;
1221 return 0;
1222 }
1223
1224 static int find_lkb(struct dlm_ls *ls, uint32_t lkid, struct dlm_lkb **lkb_ret)
1225 {
1226 struct dlm_lkb *lkb;
1227
1228 spin_lock(&ls->ls_lkbidr_spin);
1229 lkb = idr_find(&ls->ls_lkbidr, lkid);
1230 if (lkb)
1231 kref_get(&lkb->lkb_ref);
1232 spin_unlock(&ls->ls_lkbidr_spin);
1233
1234 *lkb_ret = lkb;
1235 return lkb ? 0 : -ENOENT;
1236 }
1237
1238 static void kill_lkb(struct kref *kref)
1239 {
1240 struct dlm_lkb *lkb = container_of(kref, struct dlm_lkb, lkb_ref);
1241
1242 /* All work is done after the return from kref_put() so we
1243 can release the write_lock before the detach_lkb */
1244
1245 DLM_ASSERT(!lkb->lkb_status, dlm_print_lkb(lkb););
1246 }
1247
1248 /* __put_lkb() is used when an lkb may not have an rsb attached to
1249 it so we need to provide the lockspace explicitly */
1250
1251 static int __put_lkb(struct dlm_ls *ls, struct dlm_lkb *lkb)
1252 {
1253 uint32_t lkid = lkb->lkb_id;
1254
1255 spin_lock(&ls->ls_lkbidr_spin);
1256 if (kref_put(&lkb->lkb_ref, kill_lkb)) {
1257 idr_remove(&ls->ls_lkbidr, lkid);
1258 spin_unlock(&ls->ls_lkbidr_spin);
1259
1260 detach_lkb(lkb);
1261
1262 /* for local/process lkbs, lvbptr points to caller's lksb */
1263 if (lkb->lkb_lvbptr && is_master_copy(lkb))
1264 dlm_free_lvb(lkb->lkb_lvbptr);
1265 dlm_free_lkb(lkb);
1266 return 1;
1267 } else {
1268 spin_unlock(&ls->ls_lkbidr_spin);
1269 return 0;
1270 }
1271 }
1272
1273 int dlm_put_lkb(struct dlm_lkb *lkb)
1274 {
1275 struct dlm_ls *ls;
1276
1277 DLM_ASSERT(lkb->lkb_resource, dlm_print_lkb(lkb););
1278 DLM_ASSERT(lkb->lkb_resource->res_ls, dlm_print_lkb(lkb););
1279
1280 ls = lkb->lkb_resource->res_ls;
1281 return __put_lkb(ls, lkb);
1282 }
1283
1284 /* This is only called to add a reference when the code already holds
1285 a valid reference to the lkb, so there's no need for locking. */
1286
1287 static inline void hold_lkb(struct dlm_lkb *lkb)
1288 {
1289 kref_get(&lkb->lkb_ref);
1290 }
1291
1292 /* This is called when we need to remove a reference and are certain
1293 it's not the last ref. e.g. del_lkb is always called between a
1294 find_lkb/put_lkb and is always the inverse of a previous add_lkb.
1295 put_lkb would work fine, but would involve unnecessary locking */
1296
1297 static inline void unhold_lkb(struct dlm_lkb *lkb)
1298 {
1299 int rv;
1300 rv = kref_put(&lkb->lkb_ref, kill_lkb);
1301 DLM_ASSERT(!rv, dlm_print_lkb(lkb););
1302 }
1303
1304 static void lkb_add_ordered(struct list_head *new, struct list_head *head,
1305 int mode)
1306 {
1307 struct dlm_lkb *lkb = NULL;
1308
1309 list_for_each_entry(lkb, head, lkb_statequeue)
1310 if (lkb->lkb_rqmode < mode)
1311 break;
1312
1313 __list_add(new, lkb->lkb_statequeue.prev, &lkb->lkb_statequeue);
1314 }
1315
1316 /* add/remove lkb to rsb's grant/convert/wait queue */
1317
1318 static void add_lkb(struct dlm_rsb *r, struct dlm_lkb *lkb, int status)
1319 {
1320 kref_get(&lkb->lkb_ref);
1321
1322 DLM_ASSERT(!lkb->lkb_status, dlm_print_lkb(lkb););
1323
1324 lkb->lkb_timestamp = ktime_get();
1325
1326 lkb->lkb_status = status;
1327
1328 switch (status) {
1329 case DLM_LKSTS_WAITING:
1330 if (lkb->lkb_exflags & DLM_LKF_HEADQUE)
1331 list_add(&lkb->lkb_statequeue, &r->res_waitqueue);
1332 else
1333 list_add_tail(&lkb->lkb_statequeue, &r->res_waitqueue);
1334 break;
1335 case DLM_LKSTS_GRANTED:
1336 /* convention says granted locks kept in order of grmode */
1337 lkb_add_ordered(&lkb->lkb_statequeue, &r->res_grantqueue,
1338 lkb->lkb_grmode);
1339 break;
1340 case DLM_LKSTS_CONVERT:
1341 if (lkb->lkb_exflags & DLM_LKF_HEADQUE)
1342 list_add(&lkb->lkb_statequeue, &r->res_convertqueue);
1343 else
1344 list_add_tail(&lkb->lkb_statequeue,
1345 &r->res_convertqueue);
1346 break;
1347 default:
1348 DLM_ASSERT(0, dlm_print_lkb(lkb); printk("sts=%d\n", status););
1349 }
1350 }
1351
1352 static void del_lkb(struct dlm_rsb *r, struct dlm_lkb *lkb)
1353 {
1354 lkb->lkb_status = 0;
1355 list_del(&lkb->lkb_statequeue);
1356 unhold_lkb(lkb);
1357 }
1358
1359 static void move_lkb(struct dlm_rsb *r, struct dlm_lkb *lkb, int sts)
1360 {
1361 hold_lkb(lkb);
1362 del_lkb(r, lkb);
1363 add_lkb(r, lkb, sts);
1364 unhold_lkb(lkb);
1365 }
1366
1367 static int msg_reply_type(int mstype)
1368 {
1369 switch (mstype) {
1370 case DLM_MSG_REQUEST:
1371 return DLM_MSG_REQUEST_REPLY;
1372 case DLM_MSG_CONVERT:
1373 return DLM_MSG_CONVERT_REPLY;
1374 case DLM_MSG_UNLOCK:
1375 return DLM_MSG_UNLOCK_REPLY;
1376 case DLM_MSG_CANCEL:
1377 return DLM_MSG_CANCEL_REPLY;
1378 case DLM_MSG_LOOKUP:
1379 return DLM_MSG_LOOKUP_REPLY;
1380 }
1381 return -1;
1382 }
1383
1384 static int nodeid_warned(int nodeid, int num_nodes, int *warned)
1385 {
1386 int i;
1387
1388 for (i = 0; i < num_nodes; i++) {
1389 if (!warned[i]) {
1390 warned[i] = nodeid;
1391 return 0;
1392 }
1393 if (warned[i] == nodeid)
1394 return 1;
1395 }
1396 return 0;
1397 }
1398
1399 void dlm_scan_waiters(struct dlm_ls *ls)
1400 {
1401 struct dlm_lkb *lkb;
1402 ktime_t zero = ktime_set(0, 0);
1403 s64 us;
1404 s64 debug_maxus = 0;
1405 u32 debug_scanned = 0;
1406 u32 debug_expired = 0;
1407 int num_nodes = 0;
1408 int *warned = NULL;
1409
1410 if (!dlm_config.ci_waitwarn_us)
1411 return;
1412
1413 mutex_lock(&ls->ls_waiters_mutex);
1414
1415 list_for_each_entry(lkb, &ls->ls_waiters, lkb_wait_reply) {
1416 if (ktime_equal(lkb->lkb_wait_time, zero))
1417 continue;
1418
1419 debug_scanned++;
1420
1421 us = ktime_to_us(ktime_sub(ktime_get(), lkb->lkb_wait_time));
1422
1423 if (us < dlm_config.ci_waitwarn_us)
1424 continue;
1425
1426 lkb->lkb_wait_time = zero;
1427
1428 debug_expired++;
1429 if (us > debug_maxus)
1430 debug_maxus = us;
1431
1432 if (!num_nodes) {
1433 num_nodes = ls->ls_num_nodes;
1434 warned = kzalloc(num_nodes * sizeof(int), GFP_KERNEL);
1435 }
1436 if (!warned)
1437 continue;
1438 if (nodeid_warned(lkb->lkb_wait_nodeid, num_nodes, warned))
1439 continue;
1440
1441 log_error(ls, "waitwarn %x %lld %d us check connection to "
1442 "node %d", lkb->lkb_id, (long long)us,
1443 dlm_config.ci_waitwarn_us, lkb->lkb_wait_nodeid);
1444 }
1445 mutex_unlock(&ls->ls_waiters_mutex);
1446 kfree(warned);
1447
1448 if (debug_expired)
1449 log_debug(ls, "scan_waiters %u warn %u over %d us max %lld us",
1450 debug_scanned, debug_expired,
1451 dlm_config.ci_waitwarn_us, (long long)debug_maxus);
1452 }
1453
1454 /* add/remove lkb from global waiters list of lkb's waiting for
1455 a reply from a remote node */
1456
1457 static int add_to_waiters(struct dlm_lkb *lkb, int mstype, int to_nodeid)
1458 {
1459 struct dlm_ls *ls = lkb->lkb_resource->res_ls;
1460 int error = 0;
1461
1462 mutex_lock(&ls->ls_waiters_mutex);
1463
1464 if (is_overlap_unlock(lkb) ||
1465 (is_overlap_cancel(lkb) && (mstype == DLM_MSG_CANCEL))) {
1466 error = -EINVAL;
1467 goto out;
1468 }
1469
1470 if (lkb->lkb_wait_type || is_overlap_cancel(lkb)) {
1471 switch (mstype) {
1472 case DLM_MSG_UNLOCK:
1473 lkb->lkb_flags |= DLM_IFL_OVERLAP_UNLOCK;
1474 break;
1475 case DLM_MSG_CANCEL:
1476 lkb->lkb_flags |= DLM_IFL_OVERLAP_CANCEL;
1477 break;
1478 default:
1479 error = -EBUSY;
1480 goto out;
1481 }
1482 lkb->lkb_wait_count++;
1483 hold_lkb(lkb);
1484
1485 log_debug(ls, "addwait %x cur %d overlap %d count %d f %x",
1486 lkb->lkb_id, lkb->lkb_wait_type, mstype,
1487 lkb->lkb_wait_count, lkb->lkb_flags);
1488 goto out;
1489 }
1490
1491 DLM_ASSERT(!lkb->lkb_wait_count,
1492 dlm_print_lkb(lkb);
1493 printk("wait_count %d\n", lkb->lkb_wait_count););
1494
1495 lkb->lkb_wait_count++;
1496 lkb->lkb_wait_type = mstype;
1497 lkb->lkb_wait_time = ktime_get();
1498 lkb->lkb_wait_nodeid = to_nodeid; /* for debugging */
1499 hold_lkb(lkb);
1500 list_add(&lkb->lkb_wait_reply, &ls->ls_waiters);
1501 out:
1502 if (error)
1503 log_error(ls, "addwait error %x %d flags %x %d %d %s",
1504 lkb->lkb_id, error, lkb->lkb_flags, mstype,
1505 lkb->lkb_wait_type, lkb->lkb_resource->res_name);
1506 mutex_unlock(&ls->ls_waiters_mutex);
1507 return error;
1508 }
1509
1510 /* We clear the RESEND flag because we might be taking an lkb off the waiters
1511 list as part of process_requestqueue (e.g. a lookup that has an optimized
1512 request reply on the requestqueue) between dlm_recover_waiters_pre() which
1513 set RESEND and dlm_recover_waiters_post() */
1514
1515 static int _remove_from_waiters(struct dlm_lkb *lkb, int mstype,
1516 struct dlm_message *ms)
1517 {
1518 struct dlm_ls *ls = lkb->lkb_resource->res_ls;
1519 int overlap_done = 0;
1520
1521 if (is_overlap_unlock(lkb) && (mstype == DLM_MSG_UNLOCK_REPLY)) {
1522 log_debug(ls, "remwait %x unlock_reply overlap", lkb->lkb_id);
1523 lkb->lkb_flags &= ~DLM_IFL_OVERLAP_UNLOCK;
1524 overlap_done = 1;
1525 goto out_del;
1526 }
1527
1528 if (is_overlap_cancel(lkb) && (mstype == DLM_MSG_CANCEL_REPLY)) {
1529 log_debug(ls, "remwait %x cancel_reply overlap", lkb->lkb_id);
1530 lkb->lkb_flags &= ~DLM_IFL_OVERLAP_CANCEL;
1531 overlap_done = 1;
1532 goto out_del;
1533 }
1534
1535 /* Cancel state was preemptively cleared by a successful convert,
1536 see next comment, nothing to do. */
1537
1538 if ((mstype == DLM_MSG_CANCEL_REPLY) &&
1539 (lkb->lkb_wait_type != DLM_MSG_CANCEL)) {
1540 log_debug(ls, "remwait %x cancel_reply wait_type %d",
1541 lkb->lkb_id, lkb->lkb_wait_type);
1542 return -1;
1543 }
1544
1545 /* Remove for the convert reply, and premptively remove for the
1546 cancel reply. A convert has been granted while there's still
1547 an outstanding cancel on it (the cancel is moot and the result
1548 in the cancel reply should be 0). We preempt the cancel reply
1549 because the app gets the convert result and then can follow up
1550 with another op, like convert. This subsequent op would see the
1551 lingering state of the cancel and fail with -EBUSY. */
1552
1553 if ((mstype == DLM_MSG_CONVERT_REPLY) &&
1554 (lkb->lkb_wait_type == DLM_MSG_CONVERT) &&
1555 is_overlap_cancel(lkb) && ms && !ms->m_result) {
1556 log_debug(ls, "remwait %x convert_reply zap overlap_cancel",
1557 lkb->lkb_id);
1558 lkb->lkb_wait_type = 0;
1559 lkb->lkb_flags &= ~DLM_IFL_OVERLAP_CANCEL;
1560 lkb->lkb_wait_count--;
1561 goto out_del;
1562 }
1563
1564 /* N.B. type of reply may not always correspond to type of original
1565 msg due to lookup->request optimization, verify others? */
1566
1567 if (lkb->lkb_wait_type) {
1568 lkb->lkb_wait_type = 0;
1569 goto out_del;
1570 }
1571
1572 log_error(ls, "remwait error %x remote %d %x msg %d flags %x no wait",
1573 lkb->lkb_id, ms ? ms->m_header.h_nodeid : 0, lkb->lkb_remid,
1574 mstype, lkb->lkb_flags);
1575 return -1;
1576
1577 out_del:
1578 /* the force-unlock/cancel has completed and we haven't recvd a reply
1579 to the op that was in progress prior to the unlock/cancel; we
1580 give up on any reply to the earlier op. FIXME: not sure when/how
1581 this would happen */
1582
1583 if (overlap_done && lkb->lkb_wait_type) {
1584 log_error(ls, "remwait error %x reply %d wait_type %d overlap",
1585 lkb->lkb_id, mstype, lkb->lkb_wait_type);
1586 lkb->lkb_wait_count--;
1587 lkb->lkb_wait_type = 0;
1588 }
1589
1590 DLM_ASSERT(lkb->lkb_wait_count, dlm_print_lkb(lkb););
1591
1592 lkb->lkb_flags &= ~DLM_IFL_RESEND;
1593 lkb->lkb_wait_count--;
1594 if (!lkb->lkb_wait_count)
1595 list_del_init(&lkb->lkb_wait_reply);
1596 unhold_lkb(lkb);
1597 return 0;
1598 }
1599
1600 static int remove_from_waiters(struct dlm_lkb *lkb, int mstype)
1601 {
1602 struct dlm_ls *ls = lkb->lkb_resource->res_ls;
1603 int error;
1604
1605 mutex_lock(&ls->ls_waiters_mutex);
1606 error = _remove_from_waiters(lkb, mstype, NULL);
1607 mutex_unlock(&ls->ls_waiters_mutex);
1608 return error;
1609 }
1610
1611 /* Handles situations where we might be processing a "fake" or "stub" reply in
1612 which we can't try to take waiters_mutex again. */
1613
1614 static int remove_from_waiters_ms(struct dlm_lkb *lkb, struct dlm_message *ms)
1615 {
1616 struct dlm_ls *ls = lkb->lkb_resource->res_ls;
1617 int error;
1618
1619 if (ms->m_flags != DLM_IFL_STUB_MS)
1620 mutex_lock(&ls->ls_waiters_mutex);
1621 error = _remove_from_waiters(lkb, ms->m_type, ms);
1622 if (ms->m_flags != DLM_IFL_STUB_MS)
1623 mutex_unlock(&ls->ls_waiters_mutex);
1624 return error;
1625 }
1626
1627 /* If there's an rsb for the same resource being removed, ensure
1628 that the remove message is sent before the new lookup message.
1629 It should be rare to need a delay here, but if not, then it may
1630 be worthwhile to add a proper wait mechanism rather than a delay. */
1631
1632 static void wait_pending_remove(struct dlm_rsb *r)
1633 {
1634 struct dlm_ls *ls = r->res_ls;
1635 restart:
1636 spin_lock(&ls->ls_remove_spin);
1637 if (ls->ls_remove_len &&
1638 !rsb_cmp(r, ls->ls_remove_name, ls->ls_remove_len)) {
1639 log_debug(ls, "delay lookup for remove dir %d %s",
1640 r->res_dir_nodeid, r->res_name);
1641 spin_unlock(&ls->ls_remove_spin);
1642 msleep(1);
1643 goto restart;
1644 }
1645 spin_unlock(&ls->ls_remove_spin);
1646 }
1647
1648 /*
1649 * ls_remove_spin protects ls_remove_name and ls_remove_len which are
1650 * read by other threads in wait_pending_remove. ls_remove_names
1651 * and ls_remove_lens are only used by the scan thread, so they do
1652 * not need protection.
1653 */
1654
1655 static void shrink_bucket(struct dlm_ls *ls, int b)
1656 {
1657 struct rb_node *n, *next;
1658 struct dlm_rsb *r;
1659 char *name;
1660 int our_nodeid = dlm_our_nodeid();
1661 int remote_count = 0;
1662 int i, len, rv;
1663
1664 memset(&ls->ls_remove_lens, 0, sizeof(int) * DLM_REMOVE_NAMES_MAX);
1665
1666 spin_lock(&ls->ls_rsbtbl[b].lock);
1667 for (n = rb_first(&ls->ls_rsbtbl[b].toss); n; n = next) {
1668 next = rb_next(n);
1669 r = rb_entry(n, struct dlm_rsb, res_hashnode);
1670
1671 /* If we're the directory record for this rsb, and
1672 we're not the master of it, then we need to wait
1673 for the master node to send us a dir remove for
1674 before removing the dir record. */
1675
1676 if (!dlm_no_directory(ls) &&
1677 (r->res_master_nodeid != our_nodeid) &&
1678 (dlm_dir_nodeid(r) == our_nodeid)) {
1679 continue;
1680 }
1681
1682 if (!time_after_eq(jiffies, r->res_toss_time +
1683 dlm_config.ci_toss_secs * HZ)) {
1684 continue;
1685 }
1686
1687 if (!dlm_no_directory(ls) &&
1688 (r->res_master_nodeid == our_nodeid) &&
1689 (dlm_dir_nodeid(r) != our_nodeid)) {
1690
1691 /* We're the master of this rsb but we're not
1692 the directory record, so we need to tell the
1693 dir node to remove the dir record. */
1694
1695 ls->ls_remove_lens[remote_count] = r->res_length;
1696 memcpy(ls->ls_remove_names[remote_count], r->res_name,
1697 DLM_RESNAME_MAXLEN);
1698 remote_count++;
1699
1700 if (remote_count >= DLM_REMOVE_NAMES_MAX)
1701 break;
1702 continue;
1703 }
1704
1705 if (!kref_put(&r->res_ref, kill_rsb)) {
1706 log_error(ls, "tossed rsb in use %s", r->res_name);
1707 continue;
1708 }
1709
1710 rb_erase(&r->res_hashnode, &ls->ls_rsbtbl[b].toss);
1711 dlm_free_rsb(r);
1712 }
1713 spin_unlock(&ls->ls_rsbtbl[b].lock);
1714
1715 /*
1716 * While searching for rsb's to free, we found some that require
1717 * remote removal. We leave them in place and find them again here
1718 * so there is a very small gap between removing them from the toss
1719 * list and sending the removal. Keeping this gap small is
1720 * important to keep us (the master node) from being out of sync
1721 * with the remote dir node for very long.
1722 *
1723 * From the time the rsb is removed from toss until just after
1724 * send_remove, the rsb name is saved in ls_remove_name. A new
1725 * lookup checks this to ensure that a new lookup message for the
1726 * same resource name is not sent just before the remove message.
1727 */
1728
1729 for (i = 0; i < remote_count; i++) {
1730 name = ls->ls_remove_names[i];
1731 len = ls->ls_remove_lens[i];
1732
1733 spin_lock(&ls->ls_rsbtbl[b].lock);
1734 rv = dlm_search_rsb_tree(&ls->ls_rsbtbl[b].toss, name, len, &r);
1735 if (rv) {
1736 spin_unlock(&ls->ls_rsbtbl[b].lock);
1737 log_debug(ls, "remove_name not toss %s", name);
1738 continue;
1739 }
1740
1741 if (r->res_master_nodeid != our_nodeid) {
1742 spin_unlock(&ls->ls_rsbtbl[b].lock);
1743 log_debug(ls, "remove_name master %d dir %d our %d %s",
1744 r->res_master_nodeid, r->res_dir_nodeid,
1745 our_nodeid, name);
1746 continue;
1747 }
1748
1749 if (r->res_dir_nodeid == our_nodeid) {
1750 /* should never happen */
1751 spin_unlock(&ls->ls_rsbtbl[b].lock);
1752 log_error(ls, "remove_name dir %d master %d our %d %s",
1753 r->res_dir_nodeid, r->res_master_nodeid,
1754 our_nodeid, name);
1755 continue;
1756 }
1757
1758 if (!time_after_eq(jiffies, r->res_toss_time +
1759 dlm_config.ci_toss_secs * HZ)) {
1760 spin_unlock(&ls->ls_rsbtbl[b].lock);
1761 log_debug(ls, "remove_name toss_time %lu now %lu %s",
1762 r->res_toss_time, jiffies, name);
1763 continue;
1764 }
1765
1766 if (!kref_put(&r->res_ref, kill_rsb)) {
1767 spin_unlock(&ls->ls_rsbtbl[b].lock);
1768 log_error(ls, "remove_name in use %s", name);
1769 continue;
1770 }
1771
1772 rb_erase(&r->res_hashnode, &ls->ls_rsbtbl[b].toss);
1773
1774 /* block lookup of same name until we've sent remove */
1775 spin_lock(&ls->ls_remove_spin);
1776 ls->ls_remove_len = len;
1777 memcpy(ls->ls_remove_name, name, DLM_RESNAME_MAXLEN);
1778 spin_unlock(&ls->ls_remove_spin);
1779 spin_unlock(&ls->ls_rsbtbl[b].lock);
1780
1781 send_remove(r);
1782
1783 /* allow lookup of name again */
1784 spin_lock(&ls->ls_remove_spin);
1785 ls->ls_remove_len = 0;
1786 memset(ls->ls_remove_name, 0, DLM_RESNAME_MAXLEN);
1787 spin_unlock(&ls->ls_remove_spin);
1788
1789 dlm_free_rsb(r);
1790 }
1791 }
1792
1793 void dlm_scan_rsbs(struct dlm_ls *ls)
1794 {
1795 int i;
1796
1797 for (i = 0; i < ls->ls_rsbtbl_size; i++) {
1798 shrink_bucket(ls, i);
1799 if (dlm_locking_stopped(ls))
1800 break;
1801 cond_resched();
1802 }
1803 }
1804
1805 static void add_timeout(struct dlm_lkb *lkb)
1806 {
1807 struct dlm_ls *ls = lkb->lkb_resource->res_ls;
1808
1809 if (is_master_copy(lkb))
1810 return;
1811
1812 if (test_bit(LSFL_TIMEWARN, &ls->ls_flags) &&
1813 !(lkb->lkb_exflags & DLM_LKF_NODLCKWT)) {
1814 lkb->lkb_flags |= DLM_IFL_WATCH_TIMEWARN;
1815 goto add_it;
1816 }
1817 if (lkb->lkb_exflags & DLM_LKF_TIMEOUT)
1818 goto add_it;
1819 return;
1820
1821 add_it:
1822 DLM_ASSERT(list_empty(&lkb->lkb_time_list), dlm_print_lkb(lkb););
1823 mutex_lock(&ls->ls_timeout_mutex);
1824 hold_lkb(lkb);
1825 list_add_tail(&lkb->lkb_time_list, &ls->ls_timeout);
1826 mutex_unlock(&ls->ls_timeout_mutex);
1827 }
1828
1829 static void del_timeout(struct dlm_lkb *lkb)
1830 {
1831 struct dlm_ls *ls = lkb->lkb_resource->res_ls;
1832
1833 mutex_lock(&ls->ls_timeout_mutex);
1834 if (!list_empty(&lkb->lkb_time_list)) {
1835 list_del_init(&lkb->lkb_time_list);
1836 unhold_lkb(lkb);
1837 }
1838 mutex_unlock(&ls->ls_timeout_mutex);
1839 }
1840
1841 /* FIXME: is it safe to look at lkb_exflags, lkb_flags, lkb_timestamp, and
1842 lkb_lksb_timeout without lock_rsb? Note: we can't lock timeout_mutex
1843 and then lock rsb because of lock ordering in add_timeout. We may need
1844 to specify some special timeout-related bits in the lkb that are just to
1845 be accessed under the timeout_mutex. */
1846
1847 void dlm_scan_timeout(struct dlm_ls *ls)
1848 {
1849 struct dlm_rsb *r;
1850 struct dlm_lkb *lkb;
1851 int do_cancel, do_warn;
1852 s64 wait_us;
1853
1854 for (;;) {
1855 if (dlm_locking_stopped(ls))
1856 break;
1857
1858 do_cancel = 0;
1859 do_warn = 0;
1860 mutex_lock(&ls->ls_timeout_mutex);
1861 list_for_each_entry(lkb, &ls->ls_timeout, lkb_time_list) {
1862
1863 wait_us = ktime_to_us(ktime_sub(ktime_get(),
1864 lkb->lkb_timestamp));
1865
1866 if ((lkb->lkb_exflags & DLM_LKF_TIMEOUT) &&
1867 wait_us >= (lkb->lkb_timeout_cs * 10000))
1868 do_cancel = 1;
1869
1870 if ((lkb->lkb_flags & DLM_IFL_WATCH_TIMEWARN) &&
1871 wait_us >= dlm_config.ci_timewarn_cs * 10000)
1872 do_warn = 1;
1873
1874 if (!do_cancel && !do_warn)
1875 continue;
1876 hold_lkb(lkb);
1877 break;
1878 }
1879 mutex_unlock(&ls->ls_timeout_mutex);
1880
1881 if (!do_cancel && !do_warn)
1882 break;
1883
1884 r = lkb->lkb_resource;
1885 hold_rsb(r);
1886 lock_rsb(r);
1887
1888 if (do_warn) {
1889 /* clear flag so we only warn once */
1890 lkb->lkb_flags &= ~DLM_IFL_WATCH_TIMEWARN;
1891 if (!(lkb->lkb_exflags & DLM_LKF_TIMEOUT))
1892 del_timeout(lkb);
1893 dlm_timeout_warn(lkb);
1894 }
1895
1896 if (do_cancel) {
1897 log_debug(ls, "timeout cancel %x node %d %s",
1898 lkb->lkb_id, lkb->lkb_nodeid, r->res_name);
1899 lkb->lkb_flags &= ~DLM_IFL_WATCH_TIMEWARN;
1900 lkb->lkb_flags |= DLM_IFL_TIMEOUT_CANCEL;
1901 del_timeout(lkb);
1902 _cancel_lock(r, lkb);
1903 }
1904
1905 unlock_rsb(r);
1906 unhold_rsb(r);
1907 dlm_put_lkb(lkb);
1908 }
1909 }
1910
1911 /* This is only called by dlm_recoverd, and we rely on dlm_ls_stop() stopping
1912 dlm_recoverd before checking/setting ls_recover_begin. */
1913
1914 void dlm_adjust_timeouts(struct dlm_ls *ls)
1915 {
1916 struct dlm_lkb *lkb;
1917 u64 adj_us = jiffies_to_usecs(jiffies - ls->ls_recover_begin);
1918
1919 ls->ls_recover_begin = 0;
1920 mutex_lock(&ls->ls_timeout_mutex);
1921 list_for_each_entry(lkb, &ls->ls_timeout, lkb_time_list)
1922 lkb->lkb_timestamp = ktime_add_us(lkb->lkb_timestamp, adj_us);
1923 mutex_unlock(&ls->ls_timeout_mutex);
1924
1925 if (!dlm_config.ci_waitwarn_us)
1926 return;
1927
1928 mutex_lock(&ls->ls_waiters_mutex);
1929 list_for_each_entry(lkb, &ls->ls_waiters, lkb_wait_reply) {
1930 if (ktime_to_us(lkb->lkb_wait_time))
1931 lkb->lkb_wait_time = ktime_get();
1932 }
1933 mutex_unlock(&ls->ls_waiters_mutex);
1934 }
1935
1936 /* lkb is master or local copy */
1937
1938 static void set_lvb_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
1939 {
1940 int b, len = r->res_ls->ls_lvblen;
1941
1942 /* b=1 lvb returned to caller
1943 b=0 lvb written to rsb or invalidated
1944 b=-1 do nothing */
1945
1946 b = dlm_lvb_operations[lkb->lkb_grmode + 1][lkb->lkb_rqmode + 1];
1947
1948 if (b == 1) {
1949 if (!lkb->lkb_lvbptr)
1950 return;
1951
1952 if (!(lkb->lkb_exflags & DLM_LKF_VALBLK))
1953 return;
1954
1955 if (!r->res_lvbptr)
1956 return;
1957
1958 memcpy(lkb->lkb_lvbptr, r->res_lvbptr, len);
1959 lkb->lkb_lvbseq = r->res_lvbseq;
1960
1961 } else if (b == 0) {
1962 if (lkb->lkb_exflags & DLM_LKF_IVVALBLK) {
1963 rsb_set_flag(r, RSB_VALNOTVALID);
1964 return;
1965 }
1966
1967 if (!lkb->lkb_lvbptr)
1968 return;
1969
1970 if (!(lkb->lkb_exflags & DLM_LKF_VALBLK))
1971 return;
1972
1973 if (!r->res_lvbptr)
1974 r->res_lvbptr = dlm_allocate_lvb(r->res_ls);
1975
1976 if (!r->res_lvbptr)
1977 return;
1978
1979 memcpy(r->res_lvbptr, lkb->lkb_lvbptr, len);
1980 r->res_lvbseq++;
1981 lkb->lkb_lvbseq = r->res_lvbseq;
1982 rsb_clear_flag(r, RSB_VALNOTVALID);
1983 }
1984
1985 if (rsb_flag(r, RSB_VALNOTVALID))
1986 lkb->lkb_sbflags |= DLM_SBF_VALNOTVALID;
1987 }
1988
1989 static void set_lvb_unlock(struct dlm_rsb *r, struct dlm_lkb *lkb)
1990 {
1991 if (lkb->lkb_grmode < DLM_LOCK_PW)
1992 return;
1993
1994 if (lkb->lkb_exflags & DLM_LKF_IVVALBLK) {
1995 rsb_set_flag(r, RSB_VALNOTVALID);
1996 return;
1997 }
1998
1999 if (!lkb->lkb_lvbptr)
2000 return;
2001
2002 if (!(lkb->lkb_exflags & DLM_LKF_VALBLK))
2003 return;
2004
2005 if (!r->res_lvbptr)
2006 r->res_lvbptr = dlm_allocate_lvb(r->res_ls);
2007
2008 if (!r->res_lvbptr)
2009 return;
2010
2011 memcpy(r->res_lvbptr, lkb->lkb_lvbptr, r->res_ls->ls_lvblen);
2012 r->res_lvbseq++;
2013 rsb_clear_flag(r, RSB_VALNOTVALID);
2014 }
2015
2016 /* lkb is process copy (pc) */
2017
2018 static void set_lvb_lock_pc(struct dlm_rsb *r, struct dlm_lkb *lkb,
2019 struct dlm_message *ms)
2020 {
2021 int b;
2022
2023 if (!lkb->lkb_lvbptr)
2024 return;
2025
2026 if (!(lkb->lkb_exflags & DLM_LKF_VALBLK))
2027 return;
2028
2029 b = dlm_lvb_operations[lkb->lkb_grmode + 1][lkb->lkb_rqmode + 1];
2030 if (b == 1) {
2031 int len = receive_extralen(ms);
2032 if (len > DLM_RESNAME_MAXLEN)
2033 len = DLM_RESNAME_MAXLEN;
2034 memcpy(lkb->lkb_lvbptr, ms->m_extra, len);
2035 lkb->lkb_lvbseq = ms->m_lvbseq;
2036 }
2037 }
2038
2039 /* Manipulate lkb's on rsb's convert/granted/waiting queues
2040 remove_lock -- used for unlock, removes lkb from granted
2041 revert_lock -- used for cancel, moves lkb from convert to granted
2042 grant_lock -- used for request and convert, adds lkb to granted or
2043 moves lkb from convert or waiting to granted
2044
2045 Each of these is used for master or local copy lkb's. There is
2046 also a _pc() variation used to make the corresponding change on
2047 a process copy (pc) lkb. */
2048
2049 static void _remove_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
2050 {
2051 del_lkb(r, lkb);
2052 lkb->lkb_grmode = DLM_LOCK_IV;
2053 /* this unhold undoes the original ref from create_lkb()
2054 so this leads to the lkb being freed */
2055 unhold_lkb(lkb);
2056 }
2057
2058 static void remove_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
2059 {
2060 set_lvb_unlock(r, lkb);
2061 _remove_lock(r, lkb);
2062 }
2063
2064 static void remove_lock_pc(struct dlm_rsb *r, struct dlm_lkb *lkb)
2065 {
2066 _remove_lock(r, lkb);
2067 }
2068
2069 /* returns: 0 did nothing
2070 1 moved lock to granted
2071 -1 removed lock */
2072
2073 static int revert_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
2074 {
2075 int rv = 0;
2076
2077 lkb->lkb_rqmode = DLM_LOCK_IV;
2078
2079 switch (lkb->lkb_status) {
2080 case DLM_LKSTS_GRANTED:
2081 break;
2082 case DLM_LKSTS_CONVERT:
2083 move_lkb(r, lkb, DLM_LKSTS_GRANTED);
2084 rv = 1;
2085 break;
2086 case DLM_LKSTS_WAITING:
2087 del_lkb(r, lkb);
2088 lkb->lkb_grmode = DLM_LOCK_IV;
2089 /* this unhold undoes the original ref from create_lkb()
2090 so this leads to the lkb being freed */
2091 unhold_lkb(lkb);
2092 rv = -1;
2093 break;
2094 default:
2095 log_print("invalid status for revert %d", lkb->lkb_status);
2096 }
2097 return rv;
2098 }
2099
2100 static int revert_lock_pc(struct dlm_rsb *r, struct dlm_lkb *lkb)
2101 {
2102 return revert_lock(r, lkb);
2103 }
2104
2105 static void _grant_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
2106 {
2107 if (lkb->lkb_grmode != lkb->lkb_rqmode) {
2108 lkb->lkb_grmode = lkb->lkb_rqmode;
2109 if (lkb->lkb_status)
2110 move_lkb(r, lkb, DLM_LKSTS_GRANTED);
2111 else
2112 add_lkb(r, lkb, DLM_LKSTS_GRANTED);
2113 }
2114
2115 lkb->lkb_rqmode = DLM_LOCK_IV;
2116 lkb->lkb_highbast = 0;
2117 }
2118
2119 static void grant_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
2120 {
2121 set_lvb_lock(r, lkb);
2122 _grant_lock(r, lkb);
2123 }
2124
2125 static void grant_lock_pc(struct dlm_rsb *r, struct dlm_lkb *lkb,
2126 struct dlm_message *ms)
2127 {
2128 set_lvb_lock_pc(r, lkb, ms);
2129 _grant_lock(r, lkb);
2130 }
2131
2132 /* called by grant_pending_locks() which means an async grant message must
2133 be sent to the requesting node in addition to granting the lock if the
2134 lkb belongs to a remote node. */
2135
2136 static void grant_lock_pending(struct dlm_rsb *r, struct dlm_lkb *lkb)
2137 {
2138 grant_lock(r, lkb);
2139 if (is_master_copy(lkb))
2140 send_grant(r, lkb);
2141 else
2142 queue_cast(r, lkb, 0);
2143 }
2144
2145 /* The special CONVDEADLK, ALTPR and ALTCW flags allow the master to
2146 change the granted/requested modes. We're munging things accordingly in
2147 the process copy.
2148 CONVDEADLK: our grmode may have been forced down to NL to resolve a
2149 conversion deadlock
2150 ALTPR/ALTCW: our rqmode may have been changed to PR or CW to become
2151 compatible with other granted locks */
2152
2153 static void munge_demoted(struct dlm_lkb *lkb)
2154 {
2155 if (lkb->lkb_rqmode == DLM_LOCK_IV || lkb->lkb_grmode == DLM_LOCK_IV) {
2156 log_print("munge_demoted %x invalid modes gr %d rq %d",
2157 lkb->lkb_id, lkb->lkb_grmode, lkb->lkb_rqmode);
2158 return;
2159 }
2160
2161 lkb->lkb_grmode = DLM_LOCK_NL;
2162 }
2163
2164 static void munge_altmode(struct dlm_lkb *lkb, struct dlm_message *ms)
2165 {
2166 if (ms->m_type != DLM_MSG_REQUEST_REPLY &&
2167 ms->m_type != DLM_MSG_GRANT) {
2168 log_print("munge_altmode %x invalid reply type %d",
2169 lkb->lkb_id, ms->m_type);
2170 return;
2171 }
2172
2173 if (lkb->lkb_exflags & DLM_LKF_ALTPR)
2174 lkb->lkb_rqmode = DLM_LOCK_PR;
2175 else if (lkb->lkb_exflags & DLM_LKF_ALTCW)
2176 lkb->lkb_rqmode = DLM_LOCK_CW;
2177 else {
2178 log_print("munge_altmode invalid exflags %x", lkb->lkb_exflags);
2179 dlm_print_lkb(lkb);
2180 }
2181 }
2182
2183 static inline int first_in_list(struct dlm_lkb *lkb, struct list_head *head)
2184 {
2185 struct dlm_lkb *first = list_entry(head->next, struct dlm_lkb,
2186 lkb_statequeue);
2187 if (lkb->lkb_id == first->lkb_id)
2188 return 1;
2189
2190 return 0;
2191 }
2192
2193 /* Check if the given lkb conflicts with another lkb on the queue. */
2194
2195 static int queue_conflict(struct list_head *head, struct dlm_lkb *lkb)
2196 {
2197 struct dlm_lkb *this;
2198
2199 list_for_each_entry(this, head, lkb_statequeue) {
2200 if (this == lkb)
2201 continue;
2202 if (!modes_compat(this, lkb))
2203 return 1;
2204 }
2205 return 0;
2206 }
2207
2208 /*
2209 * "A conversion deadlock arises with a pair of lock requests in the converting
2210 * queue for one resource. The granted mode of each lock blocks the requested
2211 * mode of the other lock."
2212 *
2213 * Part 2: if the granted mode of lkb is preventing an earlier lkb in the
2214 * convert queue from being granted, then deadlk/demote lkb.
2215 *
2216 * Example:
2217 * Granted Queue: empty
2218 * Convert Queue: NL->EX (first lock)
2219 * PR->EX (second lock)
2220 *
2221 * The first lock can't be granted because of the granted mode of the second
2222 * lock and the second lock can't be granted because it's not first in the
2223 * list. We either cancel lkb's conversion (PR->EX) and return EDEADLK, or we
2224 * demote the granted mode of lkb (from PR to NL) if it has the CONVDEADLK
2225 * flag set and return DEMOTED in the lksb flags.
2226 *
2227 * Originally, this function detected conv-deadlk in a more limited scope:
2228 * - if !modes_compat(lkb1, lkb2) && !modes_compat(lkb2, lkb1), or
2229 * - if lkb1 was the first entry in the queue (not just earlier), and was
2230 * blocked by the granted mode of lkb2, and there was nothing on the
2231 * granted queue preventing lkb1 from being granted immediately, i.e.
2232 * lkb2 was the only thing preventing lkb1 from being granted.
2233 *
2234 * That second condition meant we'd only say there was conv-deadlk if
2235 * resolving it (by demotion) would lead to the first lock on the convert
2236 * queue being granted right away. It allowed conversion deadlocks to exist
2237 * between locks on the convert queue while they couldn't be granted anyway.
2238 *
2239 * Now, we detect and take action on conversion deadlocks immediately when
2240 * they're created, even if they may not be immediately consequential. If
2241 * lkb1 exists anywhere in the convert queue and lkb2 comes in with a granted
2242 * mode that would prevent lkb1's conversion from being granted, we do a
2243 * deadlk/demote on lkb2 right away and don't let it onto the convert queue.
2244 * I think this means that the lkb_is_ahead condition below should always
2245 * be zero, i.e. there will never be conv-deadlk between two locks that are
2246 * both already on the convert queue.
2247 */
2248
2249 static int conversion_deadlock_detect(struct dlm_rsb *r, struct dlm_lkb *lkb2)
2250 {
2251 struct dlm_lkb *lkb1;
2252 int lkb_is_ahead = 0;
2253
2254 list_for_each_entry(lkb1, &r->res_convertqueue, lkb_statequeue) {
2255 if (lkb1 == lkb2) {
2256 lkb_is_ahead = 1;
2257 continue;
2258 }
2259
2260 if (!lkb_is_ahead) {
2261 if (!modes_compat(lkb2, lkb1))
2262 return 1;
2263 } else {
2264 if (!modes_compat(lkb2, lkb1) &&
2265 !modes_compat(lkb1, lkb2))
2266 return 1;
2267 }
2268 }
2269 return 0;
2270 }
2271
2272 /*
2273 * Return 1 if the lock can be granted, 0 otherwise.
2274 * Also detect and resolve conversion deadlocks.
2275 *
2276 * lkb is the lock to be granted
2277 *
2278 * now is 1 if the function is being called in the context of the
2279 * immediate request, it is 0 if called later, after the lock has been
2280 * queued.
2281 *
2282 * recover is 1 if dlm_recover_grant() is trying to grant conversions
2283 * after recovery.
2284 *
2285 * References are from chapter 6 of "VAXcluster Principles" by Roy Davis
2286 */
2287
2288 static int _can_be_granted(struct dlm_rsb *r, struct dlm_lkb *lkb, int now,
2289 int recover)
2290 {
2291 int8_t conv = (lkb->lkb_grmode != DLM_LOCK_IV);
2292
2293 /*
2294 * 6-10: Version 5.4 introduced an option to address the phenomenon of
2295 * a new request for a NL mode lock being blocked.
2296 *
2297 * 6-11: If the optional EXPEDITE flag is used with the new NL mode
2298 * request, then it would be granted. In essence, the use of this flag
2299 * tells the Lock Manager to expedite theis request by not considering
2300 * what may be in the CONVERTING or WAITING queues... As of this
2301 * writing, the EXPEDITE flag can be used only with new requests for NL
2302 * mode locks. This flag is not valid for conversion requests.
2303 *
2304 * A shortcut. Earlier checks return an error if EXPEDITE is used in a
2305 * conversion or used with a non-NL requested mode. We also know an
2306 * EXPEDITE request is always granted immediately, so now must always
2307 * be 1. The full condition to grant an expedite request: (now &&
2308 * !conv && lkb->rqmode == DLM_LOCK_NL && (flags & EXPEDITE)) can
2309 * therefore be shortened to just checking the flag.
2310 */
2311
2312 if (lkb->lkb_exflags & DLM_LKF_EXPEDITE)
2313 return 1;
2314
2315 /*
2316 * A shortcut. Without this, !queue_conflict(grantqueue, lkb) would be
2317 * added to the remaining conditions.
2318 */
2319
2320 if (queue_conflict(&r->res_grantqueue, lkb))
2321 return 0;
2322
2323 /*
2324 * 6-3: By default, a conversion request is immediately granted if the
2325 * requested mode is compatible with the modes of all other granted
2326 * locks
2327 */
2328
2329 if (queue_conflict(&r->res_convertqueue, lkb))
2330 return 0;
2331
2332 /*
2333 * The RECOVER_GRANT flag means dlm_recover_grant() is granting
2334 * locks for a recovered rsb, on which lkb's have been rebuilt.
2335 * The lkb's may have been rebuilt on the queues in a different
2336 * order than they were in on the previous master. So, granting
2337 * queued conversions in order after recovery doesn't make sense
2338 * since the order hasn't been preserved anyway. The new order
2339 * could also have created a new "in place" conversion deadlock.
2340 * (e.g. old, failed master held granted EX, with PR->EX, NL->EX.
2341 * After recovery, there would be no granted locks, and possibly
2342 * NL->EX, PR->EX, an in-place conversion deadlock.) So, after
2343 * recovery, grant conversions without considering order.
2344 */
2345
2346 if (conv && recover)
2347 return 1;
2348
2349 /*
2350 * 6-5: But the default algorithm for deciding whether to grant or
2351 * queue conversion requests does not by itself guarantee that such
2352 * requests are serviced on a "first come first serve" basis. This, in
2353 * turn, can lead to a phenomenon known as "indefinate postponement".
2354 *
2355 * 6-7: This issue is dealt with by using the optional QUECVT flag with
2356 * the system service employed to request a lock conversion. This flag
2357 * forces certain conversion requests to be queued, even if they are
2358 * compatible with the granted modes of other locks on the same
2359 * resource. Thus, the use of this flag results in conversion requests
2360 * being ordered on a "first come first servce" basis.
2361 *
2362 * DCT: This condition is all about new conversions being able to occur
2363 * "in place" while the lock remains on the granted queue (assuming
2364 * nothing else conflicts.) IOW if QUECVT isn't set, a conversion
2365 * doesn't _have_ to go onto the convert queue where it's processed in
2366 * order. The "now" variable is necessary to distinguish converts
2367 * being received and processed for the first time now, because once a
2368 * convert is moved to the conversion queue the condition below applies
2369 * requiring fifo granting.
2370 */
2371
2372 if (now && conv && !(lkb->lkb_exflags & DLM_LKF_QUECVT))
2373 return 1;
2374
2375 /*
2376 * Even if the convert is compat with all granted locks,
2377 * QUECVT forces it behind other locks on the convert queue.
2378 */
2379
2380 if (now && conv && (lkb->lkb_exflags & DLM_LKF_QUECVT)) {
2381 if (list_empty(&r->res_convertqueue))
2382 return 1;
2383 else
2384 return 0;
2385 }
2386
2387 /*
2388 * The NOORDER flag is set to avoid the standard vms rules on grant
2389 * order.
2390 */
2391
2392 if (lkb->lkb_exflags & DLM_LKF_NOORDER)
2393 return 1;
2394
2395 /*
2396 * 6-3: Once in that queue [CONVERTING], a conversion request cannot be
2397 * granted until all other conversion requests ahead of it are granted
2398 * and/or canceled.
2399 */
2400
2401 if (!now && conv && first_in_list(lkb, &r->res_convertqueue))
2402 return 1;
2403
2404 /*
2405 * 6-4: By default, a new request is immediately granted only if all
2406 * three of the following conditions are satisfied when the request is
2407 * issued:
2408 * - The queue of ungranted conversion requests for the resource is
2409 * empty.
2410 * - The queue of ungranted new requests for the resource is empty.
2411 * - The mode of the new request is compatible with the most
2412 * restrictive mode of all granted locks on the resource.
2413 */
2414
2415 if (now && !conv && list_empty(&r->res_convertqueue) &&
2416 list_empty(&r->res_waitqueue))
2417 return 1;
2418
2419 /*
2420 * 6-4: Once a lock request is in the queue of ungranted new requests,
2421 * it cannot be granted until the queue of ungranted conversion
2422 * requests is empty, all ungranted new requests ahead of it are
2423 * granted and/or canceled, and it is compatible with the granted mode
2424 * of the most restrictive lock granted on the resource.
2425 */
2426
2427 if (!now && !conv && list_empty(&r->res_convertqueue) &&
2428 first_in_list(lkb, &r->res_waitqueue))
2429 return 1;
2430
2431 return 0;
2432 }
2433
2434 static int can_be_granted(struct dlm_rsb *r, struct dlm_lkb *lkb, int now,
2435 int recover, int *err)
2436 {
2437 int rv;
2438 int8_t alt = 0, rqmode = lkb->lkb_rqmode;
2439 int8_t is_convert = (lkb->lkb_grmode != DLM_LOCK_IV);
2440
2441 if (err)
2442 *err = 0;
2443
2444 rv = _can_be_granted(r, lkb, now, recover);
2445 if (rv)
2446 goto out;
2447
2448 /*
2449 * The CONVDEADLK flag is non-standard and tells the dlm to resolve
2450 * conversion deadlocks by demoting grmode to NL, otherwise the dlm
2451 * cancels one of the locks.
2452 */
2453
2454 if (is_convert && can_be_queued(lkb) &&
2455 conversion_deadlock_detect(r, lkb)) {
2456 if (lkb->lkb_exflags & DLM_LKF_CONVDEADLK) {
2457 lkb->lkb_grmode = DLM_LOCK_NL;
2458 lkb->lkb_sbflags |= DLM_SBF_DEMOTED;
2459 } else if (!(lkb->lkb_exflags & DLM_LKF_NODLCKWT)) {
2460 if (err)
2461 *err = -EDEADLK;
2462 else {
2463 log_print("can_be_granted deadlock %x now %d",
2464 lkb->lkb_id, now);
2465 dlm_dump_rsb(r);
2466 }
2467 }
2468 goto out;
2469 }
2470
2471 /*
2472 * The ALTPR and ALTCW flags are non-standard and tell the dlm to try
2473 * to grant a request in a mode other than the normal rqmode. It's a
2474 * simple way to provide a big optimization to applications that can
2475 * use them.
2476 */
2477
2478 if (rqmode != DLM_LOCK_PR && (lkb->lkb_exflags & DLM_LKF_ALTPR))
2479 alt = DLM_LOCK_PR;
2480 else if (rqmode != DLM_LOCK_CW && (lkb->lkb_exflags & DLM_LKF_ALTCW))
2481 alt = DLM_LOCK_CW;
2482
2483 if (alt) {
2484 lkb->lkb_rqmode = alt;
2485 rv = _can_be_granted(r, lkb, now, 0);
2486 if (rv)
2487 lkb->lkb_sbflags |= DLM_SBF_ALTMODE;
2488 else
2489 lkb->lkb_rqmode = rqmode;
2490 }
2491 out:
2492 return rv;
2493 }
2494
2495 /* FIXME: I don't think that can_be_granted() can/will demote or find deadlock
2496 for locks pending on the convert list. Once verified (watch for these
2497 log_prints), we should be able to just call _can_be_granted() and not
2498 bother with the demote/deadlk cases here (and there's no easy way to deal
2499 with a deadlk here, we'd have to generate something like grant_lock with
2500 the deadlk error.) */
2501
2502 /* Returns the highest requested mode of all blocked conversions; sets
2503 cw if there's a blocked conversion to DLM_LOCK_CW. */
2504
2505 static int grant_pending_convert(struct dlm_rsb *r, int high, int *cw,
2506 unsigned int *count)
2507 {
2508 struct dlm_lkb *lkb, *s;
2509 int recover = rsb_flag(r, RSB_RECOVER_GRANT);
2510 int hi, demoted, quit, grant_restart, demote_restart;
2511 int deadlk;
2512
2513 quit = 0;
2514 restart:
2515 grant_restart = 0;
2516 demote_restart = 0;
2517 hi = DLM_LOCK_IV;
2518
2519 list_for_each_entry_safe(lkb, s, &r->res_convertqueue, lkb_statequeue) {
2520 demoted = is_demoted(lkb);
2521 deadlk = 0;
2522
2523 if (can_be_granted(r, lkb, 0, recover, &deadlk)) {
2524 grant_lock_pending(r, lkb);
2525 grant_restart = 1;
2526 if (count)
2527 (*count)++;
2528 continue;
2529 }
2530
2531 if (!demoted && is_demoted(lkb)) {
2532 log_print("WARN: pending demoted %x node %d %s",
2533 lkb->lkb_id, lkb->lkb_nodeid, r->res_name);
2534 demote_restart = 1;
2535 continue;
2536 }
2537
2538 if (deadlk) {
2539 log_print("WARN: pending deadlock %x node %d %s",
2540 lkb->lkb_id, lkb->lkb_nodeid, r->res_name);
2541 dlm_dump_rsb(r);
2542 continue;
2543 }
2544
2545 hi = max_t(int, lkb->lkb_rqmode, hi);
2546
2547 if (cw && lkb->lkb_rqmode == DLM_LOCK_CW)
2548 *cw = 1;
2549 }
2550
2551 if (grant_restart)
2552 goto restart;
2553 if (demote_restart && !quit) {
2554 quit = 1;
2555 goto restart;
2556 }
2557
2558 return max_t(int, high, hi);
2559 }
2560
2561 static int grant_pending_wait(struct dlm_rsb *r, int high, int *cw,
2562 unsigned int *count)
2563 {
2564 struct dlm_lkb *lkb, *s;
2565
2566 list_for_each_entry_safe(lkb, s, &r->res_waitqueue, lkb_statequeue) {
2567 if (can_be_granted(r, lkb, 0, 0, NULL)) {
2568 grant_lock_pending(r, lkb);
2569 if (count)
2570 (*count)++;
2571 } else {
2572 high = max_t(int, lkb->lkb_rqmode, high);
2573 if (lkb->lkb_rqmode == DLM_LOCK_CW)
2574 *cw = 1;
2575 }
2576 }
2577
2578 return high;
2579 }
2580
2581 /* cw of 1 means there's a lock with a rqmode of DLM_LOCK_CW that's blocked
2582 on either the convert or waiting queue.
2583 high is the largest rqmode of all locks blocked on the convert or
2584 waiting queue. */
2585
2586 static int lock_requires_bast(struct dlm_lkb *gr, int high, int cw)
2587 {
2588 if (gr->lkb_grmode == DLM_LOCK_PR && cw) {
2589 if (gr->lkb_highbast < DLM_LOCK_EX)
2590 return 1;
2591 return 0;
2592 }
2593
2594 if (gr->lkb_highbast < high &&
2595 !__dlm_compat_matrix[gr->lkb_grmode+1][high+1])
2596 return 1;
2597 return 0;
2598 }
2599
2600 static void grant_pending_locks(struct dlm_rsb *r, unsigned int *count)
2601 {
2602 struct dlm_lkb *lkb, *s;
2603 int high = DLM_LOCK_IV;
2604 int cw = 0;
2605
2606 if (!is_master(r)) {
2607 log_print("grant_pending_locks r nodeid %d", r->res_nodeid);
2608 dlm_dump_rsb(r);
2609 return;
2610 }
2611
2612 high = grant_pending_convert(r, high, &cw, count);
2613 high = grant_pending_wait(r, high, &cw, count);
2614
2615 if (high == DLM_LOCK_IV)
2616 return;
2617
2618 /*
2619 * If there are locks left on the wait/convert queue then send blocking
2620 * ASTs to granted locks based on the largest requested mode (high)
2621 * found above.
2622 */
2623
2624 list_for_each_entry_safe(lkb, s, &r->res_grantqueue, lkb_statequeue) {
2625 if (lkb->lkb_bastfn && lock_requires_bast(lkb, high, cw)) {
2626 if (cw && high == DLM_LOCK_PR &&
2627 lkb->lkb_grmode == DLM_LOCK_PR)
2628 queue_bast(r, lkb, DLM_LOCK_CW);
2629 else
2630 queue_bast(r, lkb, high);
2631 lkb->lkb_highbast = high;
2632 }
2633 }
2634 }
2635
2636 static int modes_require_bast(struct dlm_lkb *gr, struct dlm_lkb *rq)
2637 {
2638 if ((gr->lkb_grmode == DLM_LOCK_PR && rq->lkb_rqmode == DLM_LOCK_CW) ||
2639 (gr->lkb_grmode == DLM_LOCK_CW && rq->lkb_rqmode == DLM_LOCK_PR)) {
2640 if (gr->lkb_highbast < DLM_LOCK_EX)
2641 return 1;
2642 return 0;
2643 }
2644
2645 if (gr->lkb_highbast < rq->lkb_rqmode && !modes_compat(gr, rq))
2646 return 1;
2647 return 0;
2648 }
2649
2650 static void send_bast_queue(struct dlm_rsb *r, struct list_head *head,
2651 struct dlm_lkb *lkb)
2652 {
2653 struct dlm_lkb *gr;
2654
2655 list_for_each_entry(gr, head, lkb_statequeue) {
2656 /* skip self when sending basts to convertqueue */
2657 if (gr == lkb)
2658 continue;
2659 if (gr->lkb_bastfn && modes_require_bast(gr, lkb)) {
2660 queue_bast(r, gr, lkb->lkb_rqmode);
2661 gr->lkb_highbast = lkb->lkb_rqmode;
2662 }
2663 }
2664 }
2665
2666 static void send_blocking_asts(struct dlm_rsb *r, struct dlm_lkb *lkb)
2667 {
2668 send_bast_queue(r, &r->res_grantqueue, lkb);
2669 }
2670
2671 static void send_blocking_asts_all(struct dlm_rsb *r, struct dlm_lkb *lkb)
2672 {
2673 send_bast_queue(r, &r->res_grantqueue, lkb);
2674 send_bast_queue(r, &r->res_convertqueue, lkb);
2675 }
2676
2677 /* set_master(r, lkb) -- set the master nodeid of a resource
2678
2679 The purpose of this function is to set the nodeid field in the given
2680 lkb using the nodeid field in the given rsb. If the rsb's nodeid is
2681 known, it can just be copied to the lkb and the function will return
2682 0. If the rsb's nodeid is _not_ known, it needs to be looked up
2683 before it can be copied to the lkb.
2684
2685 When the rsb nodeid is being looked up remotely, the initial lkb
2686 causing the lookup is kept on the ls_waiters list waiting for the
2687 lookup reply. Other lkb's waiting for the same rsb lookup are kept
2688 on the rsb's res_lookup list until the master is verified.
2689
2690 Return values:
2691 0: nodeid is set in rsb/lkb and the caller should go ahead and use it
2692 1: the rsb master is not available and the lkb has been placed on
2693 a wait queue
2694 */
2695
2696 static int set_master(struct dlm_rsb *r, struct dlm_lkb *lkb)
2697 {
2698 int our_nodeid = dlm_our_nodeid();
2699
2700 if (rsb_flag(r, RSB_MASTER_UNCERTAIN)) {
2701 rsb_clear_flag(r, RSB_MASTER_UNCERTAIN);
2702 r->res_first_lkid = lkb->lkb_id;
2703 lkb->lkb_nodeid = r->res_nodeid;
2704 return 0;
2705 }
2706
2707 if (r->res_first_lkid && r->res_first_lkid != lkb->lkb_id) {
2708 list_add_tail(&lkb->lkb_rsb_lookup, &r->res_lookup);
2709 return 1;
2710 }
2711
2712 if (r->res_master_nodeid == our_nodeid) {
2713 lkb->lkb_nodeid = 0;
2714 return 0;
2715 }
2716
2717 if (r->res_master_nodeid) {
2718 lkb->lkb_nodeid = r->res_master_nodeid;
2719 return 0;
2720 }
2721
2722 if (dlm_dir_nodeid(r) == our_nodeid) {
2723 /* This is a somewhat unusual case; find_rsb will usually
2724 have set res_master_nodeid when dir nodeid is local, but
2725 there are cases where we become the dir node after we've
2726 past find_rsb and go through _request_lock again.
2727 confirm_master() or process_lookup_list() needs to be
2728 called after this. */
2729 log_debug(r->res_ls, "set_master %x self master %d dir %d %s",
2730 lkb->lkb_id, r->res_master_nodeid, r->res_dir_nodeid,
2731 r->res_name);
2732 r->res_master_nodeid = our_nodeid;
2733 r->res_nodeid = 0;
2734 lkb->lkb_nodeid = 0;
2735 return 0;
2736 }
2737
2738 wait_pending_remove(r);
2739
2740 r->res_first_lkid = lkb->lkb_id;
2741 send_lookup(r, lkb);
2742 return 1;
2743 }
2744
2745 static void process_lookup_list(struct dlm_rsb *r)
2746 {
2747 struct dlm_lkb *lkb, *safe;
2748
2749 list_for_each_entry_safe(lkb, safe, &r->res_lookup, lkb_rsb_lookup) {
2750 list_del_init(&lkb->lkb_rsb_lookup);
2751 _request_lock(r, lkb);
2752 schedule();
2753 }
2754 }
2755
2756 /* confirm_master -- confirm (or deny) an rsb's master nodeid */
2757
2758 static void confirm_master(struct dlm_rsb *r, int error)
2759 {
2760 struct dlm_lkb *lkb;
2761
2762 if (!r->res_first_lkid)
2763 return;
2764
2765 switch (error) {
2766 case 0:
2767 case -EINPROGRESS:
2768 r->res_first_lkid = 0;
2769 process_lookup_list(r);
2770 break;
2771
2772 case -EAGAIN:
2773 case -EBADR:
2774 case -ENOTBLK:
2775 /* the remote request failed and won't be retried (it was
2776 a NOQUEUE, or has been canceled/unlocked); make a waiting
2777 lkb the first_lkid */
2778
2779 r->res_first_lkid = 0;
2780
2781 if (!list_empty(&r->res_lookup)) {
2782 lkb = list_entry(r->res_lookup.next, struct dlm_lkb,
2783 lkb_rsb_lookup);
2784 list_del_init(&lkb->lkb_rsb_lookup);
2785 r->res_first_lkid = lkb->lkb_id;
2786 _request_lock(r, lkb);
2787 }
2788 break;
2789
2790 default:
2791 log_error(r->res_ls, "confirm_master unknown error %d", error);
2792 }
2793 }
2794
2795 static int set_lock_args(int mode, struct dlm_lksb *lksb, uint32_t flags,
2796 int namelen, unsigned long timeout_cs,
2797 void (*ast) (void *astparam),
2798 void *astparam,
2799 void (*bast) (void *astparam, int mode),
2800 struct dlm_args *args)
2801 {
2802 int rv = -EINVAL;
2803
2804 /* check for invalid arg usage */
2805
2806 if (mode < 0 || mode > DLM_LOCK_EX)
2807 goto out;
2808
2809 if (!(flags & DLM_LKF_CONVERT) && (namelen > DLM_RESNAME_MAXLEN))
2810 goto out;
2811
2812 if (flags & DLM_LKF_CANCEL)
2813 goto out;
2814
2815 if (flags & DLM_LKF_QUECVT && !(flags & DLM_LKF_CONVERT))
2816 goto out;
2817
2818 if (flags & DLM_LKF_CONVDEADLK && !(flags & DLM_LKF_CONVERT))
2819 goto out;
2820
2821 if (flags & DLM_LKF_CONVDEADLK && flags & DLM_LKF_NOQUEUE)
2822 goto out;
2823
2824 if (flags & DLM_LKF_EXPEDITE && flags & DLM_LKF_CONVERT)
2825 goto out;
2826
2827 if (flags & DLM_LKF_EXPEDITE && flags & DLM_LKF_QUECVT)
2828 goto out;
2829
2830 if (flags & DLM_LKF_EXPEDITE && flags & DLM_LKF_NOQUEUE)
2831 goto out;
2832
2833 if (flags & DLM_LKF_EXPEDITE && mode != DLM_LOCK_NL)
2834 goto out;
2835
2836 if (!ast || !lksb)
2837 goto out;
2838
2839 if (flags & DLM_LKF_VALBLK && !lksb->sb_lvbptr)
2840 goto out;
2841
2842 if (flags & DLM_LKF_CONVERT && !lksb->sb_lkid)
2843 goto out;
2844
2845 /* these args will be copied to the lkb in validate_lock_args,
2846 it cannot be done now because when converting locks, fields in
2847 an active lkb cannot be modified before locking the rsb */
2848
2849 args->flags = flags;
2850 args->astfn = ast;
2851 args->astparam = astparam;
2852 args->bastfn = bast;
2853 args->timeout = timeout_cs;
2854 args->mode = mode;
2855 args->lksb = lksb;
2856 rv = 0;
2857 out:
2858 return rv;
2859 }
2860
2861 static int set_unlock_args(uint32_t flags, void *astarg, struct dlm_args *args)
2862 {
2863 if (flags & ~(DLM_LKF_CANCEL | DLM_LKF_VALBLK | DLM_LKF_IVVALBLK |
2864 DLM_LKF_FORCEUNLOCK))
2865 return -EINVAL;
2866
2867 if (flags & DLM_LKF_CANCEL && flags & DLM_LKF_FORCEUNLOCK)
2868 return -EINVAL;
2869
2870 args->flags = flags;
2871 args->astparam = astarg;
2872 return 0;
2873 }
2874
2875 static int validate_lock_args(struct dlm_ls *ls, struct dlm_lkb *lkb,
2876 struct dlm_args *args)
2877 {
2878 int rv = -EINVAL;
2879
2880 if (args->flags & DLM_LKF_CONVERT) {
2881 if (lkb->lkb_flags & DLM_IFL_MSTCPY)
2882 goto out;
2883
2884 if (args->flags & DLM_LKF_QUECVT &&
2885 !__quecvt_compat_matrix[lkb->lkb_grmode+1][args->mode+1])
2886 goto out;
2887
2888 rv = -EBUSY;
2889 if (lkb->lkb_status != DLM_LKSTS_GRANTED)
2890 goto out;
2891
2892 if (lkb->lkb_wait_type)
2893 goto out;
2894
2895 if (is_overlap(lkb))
2896 goto out;
2897 }
2898
2899 lkb->lkb_exflags = args->flags;
2900 lkb->lkb_sbflags = 0;
2901 lkb->lkb_astfn = args->astfn;
2902 lkb->lkb_astparam = args->astparam;
2903 lkb->lkb_bastfn = args->bastfn;
2904 lkb->lkb_rqmode = args->mode;
2905 lkb->lkb_lksb = args->lksb;
2906 lkb->lkb_lvbptr = args->lksb->sb_lvbptr;
2907 lkb->lkb_ownpid = (int) current->pid;
2908 lkb->lkb_timeout_cs = args->timeout;
2909 rv = 0;
2910 out:
2911 if (rv)
2912 log_debug(ls, "validate_lock_args %d %x %x %x %d %d %s",
2913 rv, lkb->lkb_id, lkb->lkb_flags, args->flags,
2914 lkb->lkb_status, lkb->lkb_wait_type,
2915 lkb->lkb_resource->res_name);
2916 return rv;
2917 }
2918
2919 /* when dlm_unlock() sees -EBUSY with CANCEL/FORCEUNLOCK it returns 0
2920 for success */
2921
2922 /* note: it's valid for lkb_nodeid/res_nodeid to be -1 when we get here
2923 because there may be a lookup in progress and it's valid to do
2924 cancel/unlockf on it */
2925
2926 static int validate_unlock_args(struct dlm_lkb *lkb, struct dlm_args *args)
2927 {
2928 struct dlm_ls *ls = lkb->lkb_resource->res_ls;
2929 int rv = -EINVAL;
2930
2931 if (lkb->lkb_flags & DLM_IFL_MSTCPY) {
2932 log_error(ls, "unlock on MSTCPY %x", lkb->lkb_id);
2933 dlm_print_lkb(lkb);
2934 goto out;
2935 }
2936
2937 /* an lkb may still exist even though the lock is EOL'ed due to a
2938 cancel, unlock or failed noqueue request; an app can't use these
2939 locks; return same error as if the lkid had not been found at all */
2940
2941 if (lkb->lkb_flags & DLM_IFL_ENDOFLIFE) {
2942 log_debug(ls, "unlock on ENDOFLIFE %x", lkb->lkb_id);
2943 rv = -ENOENT;
2944 goto out;
2945 }
2946
2947 /* an lkb may be waiting for an rsb lookup to complete where the
2948 lookup was initiated by another lock */
2949
2950 if (!list_empty(&lkb->lkb_rsb_lookup)) {
2951 if (args->flags & (DLM_LKF_CANCEL | DLM_LKF_FORCEUNLOCK)) {
2952 log_debug(ls, "unlock on rsb_lookup %x", lkb->lkb_id);
2953 list_del_init(&lkb->lkb_rsb_lookup);
2954 queue_cast(lkb->lkb_resource, lkb,
2955 args->flags & DLM_LKF_CANCEL ?
2956 -DLM_ECANCEL : -DLM_EUNLOCK);
2957 unhold_lkb(lkb); /* undoes create_lkb() */
2958 }
2959 /* caller changes -EBUSY to 0 for CANCEL and FORCEUNLOCK */
2960 rv = -EBUSY;
2961 goto out;
2962 }
2963
2964 /* cancel not allowed with another cancel/unlock in progress */
2965
2966 if (args->flags & DLM_LKF_CANCEL) {
2967 if (lkb->lkb_exflags & DLM_LKF_CANCEL)
2968 goto out;
2969
2970 if (is_overlap(lkb))
2971 goto out;
2972
2973 /* don't let scand try to do a cancel */
2974 del_timeout(lkb);
2975
2976 if (lkb->lkb_flags & DLM_IFL_RESEND) {
2977 lkb->lkb_flags |= DLM_IFL_OVERLAP_CANCEL;
2978 rv = -EBUSY;
2979 goto out;
2980 }
2981
2982 /* there's nothing to cancel */
2983 if (lkb->lkb_status == DLM_LKSTS_GRANTED &&
2984 !lkb->lkb_wait_type) {
2985 rv = -EBUSY;
2986 goto out;
2987 }
2988
2989 switch (lkb->lkb_wait_type) {
2990 case DLM_MSG_LOOKUP:
2991 case DLM_MSG_REQUEST:
2992 lkb->lkb_flags |= DLM_IFL_OVERLAP_CANCEL;
2993 rv = -EBUSY;
2994 goto out;
2995 case DLM_MSG_UNLOCK:
2996 case DLM_MSG_CANCEL:
2997 goto out;
2998 }
2999 /* add_to_waiters() will set OVERLAP_CANCEL */
3000 goto out_ok;
3001 }
3002
3003 /* do we need to allow a force-unlock if there's a normal unlock
3004 already in progress? in what conditions could the normal unlock
3005 fail such that we'd want to send a force-unlock to be sure? */
3006
3007 if (args->flags & DLM_LKF_FORCEUNLOCK) {
3008 if (lkb->lkb_exflags & DLM_LKF_FORCEUNLOCK)
3009 goto out;
3010
3011 if (is_overlap_unlock(lkb))
3012 goto out;
3013
3014 /* don't let scand try to do a cancel */
3015 del_timeout(lkb);
3016
3017 if (lkb->lkb_flags & DLM_IFL_RESEND) {
3018 lkb->lkb_flags |= DLM_IFL_OVERLAP_UNLOCK;
3019 rv = -EBUSY;
3020 goto out;
3021 }
3022
3023 switch (lkb->lkb_wait_type) {
3024 case DLM_MSG_LOOKUP:
3025 case DLM_MSG_REQUEST:
3026 lkb->lkb_flags |= DLM_IFL_OVERLAP_UNLOCK;
3027 rv = -EBUSY;
3028 goto out;
3029 case DLM_MSG_UNLOCK:
3030 goto out;
3031 }
3032 /* add_to_waiters() will set OVERLAP_UNLOCK */
3033 goto out_ok;
3034 }
3035
3036 /* normal unlock not allowed if there's any op in progress */
3037 rv = -EBUSY;
3038 if (lkb->lkb_wait_type || lkb->lkb_wait_count)
3039 goto out;
3040
3041 out_ok:
3042 /* an overlapping op shouldn't blow away exflags from other op */
3043 lkb->lkb_exflags |= args->flags;
3044 lkb->lkb_sbflags = 0;
3045 lkb->lkb_astparam = args->astparam;
3046 rv = 0;
3047 out:
3048 if (rv)
3049 log_debug(ls, "validate_unlock_args %d %x %x %x %x %d %s", rv,
3050 lkb->lkb_id, lkb->lkb_flags, lkb->lkb_exflags,
3051 args->flags, lkb->lkb_wait_type,
3052 lkb->lkb_resource->res_name);
3053 return rv;
3054 }
3055
3056 /*
3057 * Four stage 4 varieties:
3058 * do_request(), do_convert(), do_unlock(), do_cancel()
3059 * These are called on the master node for the given lock and
3060 * from the central locking logic.
3061 */
3062
3063 static int do_request(struct dlm_rsb *r, struct dlm_lkb *lkb)
3064 {
3065 int error = 0;
3066
3067 if (can_be_granted(r, lkb, 1, 0, NULL)) {
3068 grant_lock(r, lkb);
3069 queue_cast(r, lkb, 0);
3070 goto out;
3071 }
3072
3073 if (can_be_queued(lkb)) {
3074 error = -EINPROGRESS;
3075 add_lkb(r, lkb, DLM_LKSTS_WAITING);
3076 add_timeout(lkb);
3077 goto out;
3078 }
3079
3080 error = -EAGAIN;
3081 queue_cast(r, lkb, -EAGAIN);
3082 out:
3083 return error;
3084 }
3085
3086 static void do_request_effects(struct dlm_rsb *r, struct dlm_lkb *lkb,
3087 int error)
3088 {
3089 switch (error) {
3090 case -EAGAIN:
3091 if (force_blocking_asts(lkb))
3092 send_blocking_asts_all(r, lkb);
3093 break;
3094 case -EINPROGRESS:
3095 send_blocking_asts(r, lkb);
3096 break;
3097 }
3098 }
3099
3100 static int do_convert(struct dlm_rsb *r, struct dlm_lkb *lkb)
3101 {
3102 int error = 0;
3103 int deadlk = 0;
3104
3105 /* changing an existing lock may allow others to be granted */
3106
3107 if (can_be_granted(r, lkb, 1, 0, &deadlk)) {
3108 grant_lock(r, lkb);
3109 queue_cast(r, lkb, 0);
3110 goto out;
3111 }
3112
3113 /* can_be_granted() detected that this lock would block in a conversion
3114 deadlock, so we leave it on the granted queue and return EDEADLK in
3115 the ast for the convert. */
3116
3117 if (deadlk) {
3118 /* it's left on the granted queue */
3119 revert_lock(r, lkb);
3120 queue_cast(r, lkb, -EDEADLK);
3121 error = -EDEADLK;
3122 goto out;
3123 }
3124
3125 /* is_demoted() means the can_be_granted() above set the grmode
3126 to NL, and left us on the granted queue. This auto-demotion
3127 (due to CONVDEADLK) might mean other locks, and/or this lock, are
3128 now grantable. We have to try to grant other converting locks
3129 before we try again to grant this one. */
3130
3131 if (is_demoted(lkb)) {
3132 grant_pending_convert(r, DLM_LOCK_IV, NULL, NULL);
3133 if (_can_be_granted(r, lkb, 1, 0)) {
3134 grant_lock(r, lkb);
3135 queue_cast(r, lkb, 0);
3136 goto out;
3137 }
3138 /* else fall through and move to convert queue */
3139 }
3140
3141 if (can_be_queued(lkb)) {
3142 error = -EINPROGRESS;
3143 del_lkb(r, lkb);
3144 add_lkb(r, lkb, DLM_LKSTS_CONVERT);
3145 add_timeout(lkb);
3146 goto out;
3147 }
3148
3149 error = -EAGAIN;
3150 queue_cast(r, lkb, -EAGAIN);
3151 out:
3152 return error;
3153 }
3154
3155 static void do_convert_effects(struct dlm_rsb *r, struct dlm_lkb *lkb,
3156 int error)
3157 {
3158 switch (error) {
3159 case 0:
3160 grant_pending_locks(r, NULL);
3161 /* grant_pending_locks also sends basts */
3162 break;
3163 case -EAGAIN:
3164 if (force_blocking_asts(lkb))
3165 send_blocking_asts_all(r, lkb);
3166 break;
3167 case -EINPROGRESS:
3168 send_blocking_asts(r, lkb);
3169 break;
3170 }
3171 }
3172
3173 static int do_unlock(struct dlm_rsb *r, struct dlm_lkb *lkb)
3174 {
3175 remove_lock(r, lkb);
3176 queue_cast(r, lkb, -DLM_EUNLOCK);
3177 return -DLM_EUNLOCK;
3178 }
3179
3180 static void do_unlock_effects(struct dlm_rsb *r, struct dlm_lkb *lkb,
3181 int error)
3182 {
3183 grant_pending_locks(r, NULL);
3184 }
3185
3186 /* returns: 0 did nothing, -DLM_ECANCEL canceled lock */
3187
3188 static int do_cancel(struct dlm_rsb *r, struct dlm_lkb *lkb)
3189 {
3190 int error;
3191
3192 error = revert_lock(r, lkb);
3193 if (error) {
3194 queue_cast(r, lkb, -DLM_ECANCEL);
3195 return -DLM_ECANCEL;
3196 }
3197 return 0;
3198 }
3199
3200 static void do_cancel_effects(struct dlm_rsb *r, struct dlm_lkb *lkb,
3201 int error)
3202 {
3203 if (error)
3204 grant_pending_locks(r, NULL);
3205 }
3206
3207 /*
3208 * Four stage 3 varieties:
3209 * _request_lock(), _convert_lock(), _unlock_lock(), _cancel_lock()
3210 */
3211
3212 /* add a new lkb to a possibly new rsb, called by requesting process */
3213
3214 static int _request_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
3215 {
3216 int error;
3217
3218 /* set_master: sets lkb nodeid from r */
3219
3220 error = set_master(r, lkb);
3221 if (error < 0)
3222 goto out;
3223 if (error) {
3224 error = 0;
3225 goto out;
3226 }
3227
3228 if (is_remote(r)) {
3229 /* receive_request() calls do_request() on remote node */
3230 error = send_request(r, lkb);
3231 } else {
3232 error = do_request(r, lkb);
3233 /* for remote locks the request_reply is sent
3234 between do_request and do_request_effects */
3235 do_request_effects(r, lkb, error);
3236 }
3237 out:
3238 return error;
3239 }
3240
3241 /* change some property of an existing lkb, e.g. mode */
3242
3243 static int _convert_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
3244 {
3245 int error;
3246
3247 if (is_remote(r)) {
3248 /* receive_convert() calls do_convert() on remote node */
3249 error = send_convert(r, lkb);
3250 } else {
3251 error = do_convert(r, lkb);
3252 /* for remote locks the convert_reply is sent
3253 between do_convert and do_convert_effects */
3254 do_convert_effects(r, lkb, error);
3255 }
3256
3257 return error;
3258 }
3259
3260 /* remove an existing lkb from the granted queue */
3261
3262 static int _unlock_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
3263 {
3264 int error;
3265
3266 if (is_remote(r)) {
3267 /* receive_unlock() calls do_unlock() on remote node */
3268 error = send_unlock(r, lkb);
3269 } else {
3270 error = do_unlock(r, lkb);
3271 /* for remote locks the unlock_reply is sent
3272 between do_unlock and do_unlock_effects */
3273 do_unlock_effects(r, lkb, error);
3274 }
3275
3276 return error;
3277 }
3278
3279 /* remove an existing lkb from the convert or wait queue */
3280
3281 static int _cancel_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
3282 {
3283 int error;
3284
3285 if (is_remote(r)) {
3286 /* receive_cancel() calls do_cancel() on remote node */
3287 error = send_cancel(r, lkb);
3288 } else {
3289 error = do_cancel(r, lkb);
3290 /* for remote locks the cancel_reply is sent
3291 between do_cancel and do_cancel_effects */
3292 do_cancel_effects(r, lkb, error);
3293 }
3294
3295 return error;
3296 }
3297
3298 /*
3299 * Four stage 2 varieties:
3300 * request_lock(), convert_lock(), unlock_lock(), cancel_lock()
3301 */
3302
3303 static int request_lock(struct dlm_ls *ls, struct dlm_lkb *lkb, char *name,
3304 int len, struct dlm_args *args)
3305 {
3306 struct dlm_rsb *r;
3307 int error;
3308
3309 error = validate_lock_args(ls, lkb, args);
3310 if (error)
3311 return error;
3312
3313 error = find_rsb(ls, name, len, 0, R_REQUEST, &r);
3314 if (error)
3315 return error;
3316
3317 lock_rsb(r);
3318
3319 attach_lkb(r, lkb);
3320 lkb->lkb_lksb->sb_lkid = lkb->lkb_id;
3321
3322 error = _request_lock(r, lkb);
3323
3324 unlock_rsb(r);
3325 put_rsb(r);
3326 return error;
3327 }
3328
3329 static int convert_lock(struct dlm_ls *ls, struct dlm_lkb *lkb,
3330 struct dlm_args *args)
3331 {
3332 struct dlm_rsb *r;
3333 int error;
3334
3335 r = lkb->lkb_resource;
3336
3337 hold_rsb(r);
3338 lock_rsb(r);
3339
3340 error = validate_lock_args(ls, lkb, args);
3341 if (error)
3342 goto out;
3343
3344 error = _convert_lock(r, lkb);
3345 out:
3346 unlock_rsb(r);
3347 put_rsb(r);
3348 return error;
3349 }
3350
3351 static int unlock_lock(struct dlm_ls *ls, struct dlm_lkb *lkb,
3352 struct dlm_args *args)
3353 {
3354 struct dlm_rsb *r;
3355 int error;
3356
3357 r = lkb->lkb_resource;
3358
3359 hold_rsb(r);
3360 lock_rsb(r);
3361
3362 error = validate_unlock_args(lkb, args);
3363 if (error)
3364 goto out;
3365
3366 error = _unlock_lock(r, lkb);
3367 out:
3368 unlock_rsb(r);
3369 put_rsb(r);
3370 return error;
3371 }
3372
3373 static int cancel_lock(struct dlm_ls *ls, struct dlm_lkb *lkb,
3374 struct dlm_args *args)
3375 {
3376 struct dlm_rsb *r;
3377 int error;
3378
3379 r = lkb->lkb_resource;
3380
3381 hold_rsb(r);
3382 lock_rsb(r);
3383
3384 error = validate_unlock_args(lkb, args);
3385 if (error)
3386 goto out;
3387
3388 error = _cancel_lock(r, lkb);
3389 out:
3390 unlock_rsb(r);
3391 put_rsb(r);
3392 return error;
3393 }
3394
3395 /*
3396 * Two stage 1 varieties: dlm_lock() and dlm_unlock()
3397 */
3398
3399 int dlm_lock(dlm_lockspace_t *lockspace,
3400 int mode,
3401 struct dlm_lksb *lksb,
3402 uint32_t flags,
3403 void *name,
3404 unsigned int namelen,
3405 uint32_t parent_lkid,
3406 void (*ast) (void *astarg),
3407 void *astarg,
3408 void (*bast) (void *astarg, int mode))
3409 {
3410 struct dlm_ls *ls;
3411 struct dlm_lkb *lkb;
3412 struct dlm_args args;
3413 int error, convert = flags & DLM_LKF_CONVERT;
3414
3415 ls = dlm_find_lockspace_local(lockspace);
3416 if (!ls)
3417 return -EINVAL;
3418
3419 dlm_lock_recovery(ls);
3420
3421 if (convert)
3422 error = find_lkb(ls, lksb->sb_lkid, &lkb);
3423 else
3424 error = create_lkb(ls, &lkb);
3425
3426 if (error)
3427 goto out;
3428
3429 error = set_lock_args(mode, lksb, flags, namelen, 0, ast,
3430 astarg, bast, &args);
3431 if (error)
3432 goto out_put;
3433
3434 if (convert)
3435 error = convert_lock(ls, lkb, &args);
3436 else
3437 error = request_lock(ls, lkb, name, namelen, &args);
3438
3439 if (error == -EINPROGRESS)
3440 error = 0;
3441 out_put:
3442 if (convert || error)
3443 __put_lkb(ls, lkb);
3444 if (error == -EAGAIN || error == -EDEADLK)
3445 error = 0;
3446 out:
3447 dlm_unlock_recovery(ls);
3448 dlm_put_lockspace(ls);
3449 return error;
3450 }
3451
3452 int dlm_unlock(dlm_lockspace_t *lockspace,
3453 uint32_t lkid,
3454 uint32_t flags,
3455 struct dlm_lksb *lksb,
3456 void *astarg)
3457 {
3458 struct dlm_ls *ls;
3459 struct dlm_lkb *lkb;
3460 struct dlm_args args;
3461 int error;
3462
3463 ls = dlm_find_lockspace_local(lockspace);
3464 if (!ls)
3465 return -EINVAL;
3466
3467 dlm_lock_recovery(ls);
3468
3469 error = find_lkb(ls, lkid, &lkb);
3470 if (error)
3471 goto out;
3472
3473 error = set_unlock_args(flags, astarg, &args);
3474 if (error)
3475 goto out_put;
3476
3477 if (flags & DLM_LKF_CANCEL)
3478 error = cancel_lock(ls, lkb, &args);
3479 else
3480 error = unlock_lock(ls, lkb, &args);
3481
3482 if (error == -DLM_EUNLOCK || error == -DLM_ECANCEL)
3483 error = 0;
3484 if (error == -EBUSY && (flags & (DLM_LKF_CANCEL | DLM_LKF_FORCEUNLOCK)))
3485 error = 0;
3486 out_put:
3487 dlm_put_lkb(lkb);
3488 out:
3489 dlm_unlock_recovery(ls);
3490 dlm_put_lockspace(ls);
3491 return error;
3492 }
3493
3494 /*
3495 * send/receive routines for remote operations and replies
3496 *
3497 * send_args
3498 * send_common
3499 * send_request receive_request
3500 * send_convert receive_convert
3501 * send_unlock receive_unlock
3502 * send_cancel receive_cancel
3503 * send_grant receive_grant
3504 * send_bast receive_bast
3505 * send_lookup receive_lookup
3506 * send_remove receive_remove
3507 *
3508 * send_common_reply
3509 * receive_request_reply send_request_reply
3510 * receive_convert_reply send_convert_reply
3511 * receive_unlock_reply send_unlock_reply
3512 * receive_cancel_reply send_cancel_reply
3513 * receive_lookup_reply send_lookup_reply
3514 */
3515
3516 static int _create_message(struct dlm_ls *ls, int mb_len,
3517 int to_nodeid, int mstype,
3518 struct dlm_message **ms_ret,
3519 struct dlm_mhandle **mh_ret)
3520 {
3521 struct dlm_message *ms;
3522 struct dlm_mhandle *mh;
3523 char *mb;
3524
3525 /* get_buffer gives us a message handle (mh) that we need to
3526 pass into lowcomms_commit and a message buffer (mb) that we
3527 write our data into */
3528
3529 mh = dlm_lowcomms_get_buffer(to_nodeid, mb_len, GFP_NOFS, &mb);
3530 if (!mh)
3531 return -ENOBUFS;
3532
3533 memset(mb, 0, mb_len);
3534
3535 ms = (struct dlm_message *) mb;
3536
3537 ms->m_header.h_version = (DLM_HEADER_MAJOR | DLM_HEADER_MINOR);
3538 ms->m_header.h_lockspace = ls->ls_global_id;
3539 ms->m_header.h_nodeid = dlm_our_nodeid();
3540 ms->m_header.h_length = mb_len;
3541 ms->m_header.h_cmd = DLM_MSG;
3542
3543 ms->m_type = mstype;
3544
3545 *mh_ret = mh;
3546 *ms_ret = ms;
3547 return 0;
3548 }
3549
3550 static int create_message(struct dlm_rsb *r, struct dlm_lkb *lkb,
3551 int to_nodeid, int mstype,
3552 struct dlm_message **ms_ret,
3553 struct dlm_mhandle **mh_ret)
3554 {
3555 int mb_len = sizeof(struct dlm_message);
3556
3557 switch (mstype) {
3558 case DLM_MSG_REQUEST:
3559 case DLM_MSG_LOOKUP:
3560 case DLM_MSG_REMOVE:
3561 mb_len += r->res_length;
3562 break;
3563 case DLM_MSG_CONVERT:
3564 case DLM_MSG_UNLOCK:
3565 case DLM_MSG_REQUEST_REPLY:
3566 case DLM_MSG_CONVERT_REPLY:
3567 case DLM_MSG_GRANT:
3568 if (lkb && lkb->lkb_lvbptr)
3569 mb_len += r->res_ls->ls_lvblen;
3570 break;
3571 }
3572
3573 return _create_message(r->res_ls, mb_len, to_nodeid, mstype,
3574 ms_ret, mh_ret);
3575 }
3576
3577 /* further lowcomms enhancements or alternate implementations may make
3578 the return value from this function useful at some point */
3579
3580 static int send_message(struct dlm_mhandle *mh, struct dlm_message *ms)
3581 {
3582 dlm_message_out(ms);
3583 dlm_lowcomms_commit_buffer(mh);
3584 return 0;
3585 }
3586
3587 static void send_args(struct dlm_rsb *r, struct dlm_lkb *lkb,
3588 struct dlm_message *ms)
3589 {
3590 ms->m_nodeid = lkb->lkb_nodeid;
3591 ms->m_pid = lkb->lkb_ownpid;
3592 ms->m_lkid = lkb->lkb_id;
3593 ms->m_remid = lkb->lkb_remid;
3594 ms->m_exflags = lkb->lkb_exflags;
3595 ms->m_sbflags = lkb->lkb_sbflags;
3596 ms->m_flags = lkb->lkb_flags;
3597 ms->m_lvbseq = lkb->lkb_lvbseq;
3598 ms->m_status = lkb->lkb_status;
3599 ms->m_grmode = lkb->lkb_grmode;
3600 ms->m_rqmode = lkb->lkb_rqmode;
3601 ms->m_hash = r->res_hash;
3602
3603 /* m_result and m_bastmode are set from function args,
3604 not from lkb fields */
3605
3606 if (lkb->lkb_bastfn)
3607 ms->m_asts |= DLM_CB_BAST;
3608 if (lkb->lkb_astfn)
3609 ms->m_asts |= DLM_CB_CAST;
3610
3611 /* compare with switch in create_message; send_remove() doesn't
3612 use send_args() */
3613
3614 switch (ms->m_type) {
3615 case DLM_MSG_REQUEST:
3616 case DLM_MSG_LOOKUP:
3617 memcpy(ms->m_extra, r->res_name, r->res_length);
3618 break;
3619 case DLM_MSG_CONVERT:
3620 case DLM_MSG_UNLOCK:
3621 case DLM_MSG_REQUEST_REPLY:
3622 case DLM_MSG_CONVERT_REPLY:
3623 case DLM_MSG_GRANT:
3624 if (!lkb->lkb_lvbptr)
3625 break;
3626 memcpy(ms->m_extra, lkb->lkb_lvbptr, r->res_ls->ls_lvblen);
3627 break;
3628 }
3629 }
3630
3631 static int send_common(struct dlm_rsb *r, struct dlm_lkb *lkb, int mstype)
3632 {
3633 struct dlm_message *ms;
3634 struct dlm_mhandle *mh;
3635 int to_nodeid, error;
3636
3637 to_nodeid = r->res_nodeid;
3638
3639 error = add_to_waiters(lkb, mstype, to_nodeid);
3640 if (error)
3641 return error;
3642
3643 error = create_message(r, lkb, to_nodeid, mstype, &ms, &mh);
3644 if (error)
3645 goto fail;
3646
3647 send_args(r, lkb, ms);
3648
3649 error = send_message(mh, ms);
3650 if (error)
3651 goto fail;
3652 return 0;
3653
3654 fail:
3655 remove_from_waiters(lkb, msg_reply_type(mstype));
3656 return error;
3657 }
3658
3659 static int send_request(struct dlm_rsb *r, struct dlm_lkb *lkb)
3660 {
3661 return send_common(r, lkb, DLM_MSG_REQUEST);
3662 }
3663
3664 static int send_convert(struct dlm_rsb *r, struct dlm_lkb *lkb)
3665 {
3666 int error;
3667
3668 error = send_common(r, lkb, DLM_MSG_CONVERT);
3669
3670 /* down conversions go without a reply from the master */
3671 if (!error && down_conversion(lkb)) {
3672 remove_from_waiters(lkb, DLM_MSG_CONVERT_REPLY);
3673 r->res_ls->ls_stub_ms.m_flags = DLM_IFL_STUB_MS;
3674 r->res_ls->ls_stub_ms.m_type = DLM_MSG_CONVERT_REPLY;
3675 r->res_ls->ls_stub_ms.m_result = 0;
3676 __receive_convert_reply(r, lkb, &r->res_ls->ls_stub_ms);
3677 }
3678
3679 return error;
3680 }
3681
3682 /* FIXME: if this lkb is the only lock we hold on the rsb, then set
3683 MASTER_UNCERTAIN to force the next request on the rsb to confirm
3684 that the master is still correct. */
3685
3686 static int send_unlock(struct dlm_rsb *r, struct dlm_lkb *lkb)
3687 {
3688 return send_common(r, lkb, DLM_MSG_UNLOCK);
3689 }
3690
3691 static int send_cancel(struct dlm_rsb *r, struct dlm_lkb *lkb)
3692 {
3693 return send_common(r, lkb, DLM_MSG_CANCEL);
3694 }
3695
3696 static int send_grant(struct dlm_rsb *r, struct dlm_lkb *lkb)
3697 {
3698 struct dlm_message *ms;
3699 struct dlm_mhandle *mh;
3700 int to_nodeid, error;
3701
3702 to_nodeid = lkb->lkb_nodeid;
3703
3704 error = create_message(r, lkb, to_nodeid, DLM_MSG_GRANT, &ms, &mh);
3705 if (error)
3706 goto out;
3707
3708 send_args(r, lkb, ms);
3709
3710 ms->m_result = 0;
3711
3712 error = send_message(mh, ms);
3713 out:
3714 return error;
3715 }
3716
3717 static int send_bast(struct dlm_rsb *r, struct dlm_lkb *lkb, int mode)
3718 {
3719 struct dlm_message *ms;
3720 struct dlm_mhandle *mh;
3721 int to_nodeid, error;
3722
3723 to_nodeid = lkb->lkb_nodeid;
3724
3725 error = create_message(r, NULL, to_nodeid, DLM_MSG_BAST, &ms, &mh);
3726 if (error)
3727 goto out;
3728
3729 send_args(r, lkb, ms);
3730
3731 ms->m_bastmode = mode;
3732
3733 error = send_message(mh, ms);
3734 out:
3735 return error;
3736 }
3737
3738 static int send_lookup(struct dlm_rsb *r, struct dlm_lkb *lkb)
3739 {
3740 struct dlm_message *ms;
3741 struct dlm_mhandle *mh;
3742 int to_nodeid, error;
3743
3744 to_nodeid = dlm_dir_nodeid(r);
3745
3746 error = add_to_waiters(lkb, DLM_MSG_LOOKUP, to_nodeid);
3747 if (error)
3748 return error;
3749
3750 error = create_message(r, NULL, to_nodeid, DLM_MSG_LOOKUP, &ms, &mh);
3751 if (error)
3752 goto fail;
3753
3754 send_args(r, lkb, ms);
3755
3756 error = send_message(mh, ms);
3757 if (error)
3758 goto fail;
3759 return 0;
3760
3761 fail:
3762 remove_from_waiters(lkb, DLM_MSG_LOOKUP_REPLY);
3763 return error;
3764 }
3765
3766 static int send_remove(struct dlm_rsb *r)
3767 {
3768 struct dlm_message *ms;
3769 struct dlm_mhandle *mh;
3770 int to_nodeid, error;
3771
3772 to_nodeid = dlm_dir_nodeid(r);
3773
3774 error = create_message(r, NULL, to_nodeid, DLM_MSG_REMOVE, &ms, &mh);
3775 if (error)
3776 goto out;
3777
3778 memcpy(ms->m_extra, r->res_name, r->res_length);
3779 ms->m_hash = r->res_hash;
3780
3781 error = send_message(mh, ms);
3782 out:
3783 return error;
3784 }
3785
3786 static int send_common_reply(struct dlm_rsb *r, struct dlm_lkb *lkb,
3787 int mstype, int rv)
3788 {
3789 struct dlm_message *ms;
3790 struct dlm_mhandle *mh;
3791 int to_nodeid, error;
3792
3793 to_nodeid = lkb->lkb_nodeid;
3794
3795 error = create_message(r, lkb, to_nodeid, mstype, &ms, &mh);
3796 if (error)
3797 goto out;
3798
3799 send_args(r, lkb, ms);
3800
3801 ms->m_result = rv;
3802
3803 error = send_message(mh, ms);
3804 out:
3805 return error;
3806 }
3807
3808 static int send_request_reply(struct dlm_rsb *r, struct dlm_lkb *lkb, int rv)
3809 {
3810 return send_common_reply(r, lkb, DLM_MSG_REQUEST_REPLY, rv);
3811 }
3812
3813 static int send_convert_reply(struct dlm_rsb *r, struct dlm_lkb *lkb, int rv)
3814 {
3815 return send_common_reply(r, lkb, DLM_MSG_CONVERT_REPLY, rv);
3816 }
3817
3818 static int send_unlock_reply(struct dlm_rsb *r, struct dlm_lkb *lkb, int rv)
3819 {
3820 return send_common_reply(r, lkb, DLM_MSG_UNLOCK_REPLY, rv);
3821 }
3822
3823 static int send_cancel_reply(struct dlm_rsb *r, struct dlm_lkb *lkb, int rv)
3824 {
3825 return send_common_reply(r, lkb, DLM_MSG_CANCEL_REPLY, rv);
3826 }
3827
3828 static int send_lookup_reply(struct dlm_ls *ls, struct dlm_message *ms_in,
3829 int ret_nodeid, int rv)
3830 {
3831 struct dlm_rsb *r = &ls->ls_stub_rsb;
3832 struct dlm_message *ms;
3833 struct dlm_mhandle *mh;
3834 int error, nodeid = ms_in->m_header.h_nodeid;
3835
3836 error = create_message(r, NULL, nodeid, DLM_MSG_LOOKUP_REPLY, &ms, &mh);
3837 if (error)
3838 goto out;
3839
3840 ms->m_lkid = ms_in->m_lkid;
3841 ms->m_result = rv;
3842 ms->m_nodeid = ret_nodeid;
3843
3844 error = send_message(mh, ms);
3845 out:
3846 return error;
3847 }
3848
3849 /* which args we save from a received message depends heavily on the type
3850 of message, unlike the send side where we can safely send everything about
3851 the lkb for any type of message */
3852
3853 static void receive_flags(struct dlm_lkb *lkb, struct dlm_message *ms)
3854 {
3855 lkb->lkb_exflags = ms->m_exflags;
3856 lkb->lkb_sbflags = ms->m_sbflags;
3857 lkb->lkb_flags = (lkb->lkb_flags & 0xFFFF0000) |
3858 (ms->m_flags & 0x0000FFFF);
3859 }
3860
3861 static void receive_flags_reply(struct dlm_lkb *lkb, struct dlm_message *ms)
3862 {
3863 if (ms->m_flags == DLM_IFL_STUB_MS)
3864 return;
3865
3866 lkb->lkb_sbflags = ms->m_sbflags;
3867 lkb->lkb_flags = (lkb->lkb_flags & 0xFFFF0000) |
3868 (ms->m_flags & 0x0000FFFF);
3869 }
3870
3871 static int receive_extralen(struct dlm_message *ms)
3872 {
3873 return (ms->m_header.h_length - sizeof(struct dlm_message));
3874 }
3875
3876 static int receive_lvb(struct dlm_ls *ls, struct dlm_lkb *lkb,
3877 struct dlm_message *ms)
3878 {
3879 int len;
3880
3881 if (lkb->lkb_exflags & DLM_LKF_VALBLK) {
3882 if (!lkb->lkb_lvbptr)
3883 lkb->lkb_lvbptr = dlm_allocate_lvb(ls);
3884 if (!lkb->lkb_lvbptr)
3885 return -ENOMEM;
3886 len = receive_extralen(ms);
3887 if (len > DLM_RESNAME_MAXLEN)
3888 len = DLM_RESNAME_MAXLEN;
3889 memcpy(lkb->lkb_lvbptr, ms->m_extra, len);
3890 }
3891 return 0;
3892 }
3893
3894 static void fake_bastfn(void *astparam, int mode)
3895 {
3896 log_print("fake_bastfn should not be called");
3897 }
3898
3899 static void fake_astfn(void *astparam)
3900 {
3901 log_print("fake_astfn should not be called");
3902 }
3903
3904 static int receive_request_args(struct dlm_ls *ls, struct dlm_lkb *lkb,
3905 struct dlm_message *ms)
3906 {
3907 lkb->lkb_nodeid = ms->m_header.h_nodeid;
3908 lkb->lkb_ownpid = ms->m_pid;
3909 lkb->lkb_remid = ms->m_lkid;
3910 lkb->lkb_grmode = DLM_LOCK_IV;
3911 lkb->lkb_rqmode = ms->m_rqmode;
3912
3913 lkb->lkb_bastfn = (ms->m_asts & DLM_CB_BAST) ? &fake_bastfn : NULL;
3914 lkb->lkb_astfn = (ms->m_asts & DLM_CB_CAST) ? &fake_astfn : NULL;
3915
3916 if (lkb->lkb_exflags & DLM_LKF_VALBLK) {
3917 /* lkb was just created so there won't be an lvb yet */
3918 lkb->lkb_lvbptr = dlm_allocate_lvb(ls);
3919 if (!lkb->lkb_lvbptr)
3920 return -ENOMEM;
3921 }
3922
3923 return 0;
3924 }
3925
3926 static int receive_convert_args(struct dlm_ls *ls, struct dlm_lkb *lkb,
3927 struct dlm_message *ms)
3928 {
3929 if (lkb->lkb_status != DLM_LKSTS_GRANTED)
3930 return -EBUSY;
3931
3932 if (receive_lvb(ls, lkb, ms))
3933 return -ENOMEM;
3934
3935 lkb->lkb_rqmode = ms->m_rqmode;
3936 lkb->lkb_lvbseq = ms->m_lvbseq;
3937
3938 return 0;
3939 }
3940
3941 static int receive_unlock_args(struct dlm_ls *ls, struct dlm_lkb *lkb,
3942 struct dlm_message *ms)
3943 {
3944 if (receive_lvb(ls, lkb, ms))
3945 return -ENOMEM;
3946 return 0;
3947 }
3948
3949 /* We fill in the stub-lkb fields with the info that send_xxxx_reply()
3950 uses to send a reply and that the remote end uses to process the reply. */
3951
3952 static void setup_stub_lkb(struct dlm_ls *ls, struct dlm_message *ms)
3953 {
3954 struct dlm_lkb *lkb = &ls->ls_stub_lkb;
3955 lkb->lkb_nodeid = ms->m_header.h_nodeid;
3956 lkb->lkb_remid = ms->m_lkid;
3957 }
3958
3959 /* This is called after the rsb is locked so that we can safely inspect
3960 fields in the lkb. */
3961
3962 static int validate_message(struct dlm_lkb *lkb, struct dlm_message *ms)
3963 {
3964 int from = ms->m_header.h_nodeid;
3965 int error = 0;
3966
3967 switch (ms->m_type) {
3968 case DLM_MSG_CONVERT:
3969 case DLM_MSG_UNLOCK:
3970 case DLM_MSG_CANCEL:
3971 if (!is_master_copy(lkb) || lkb->lkb_nodeid != from)
3972 error = -EINVAL;
3973 break;
3974
3975 case DLM_MSG_CONVERT_REPLY:
3976 case DLM_MSG_UNLOCK_REPLY:
3977 case DLM_MSG_CANCEL_REPLY:
3978 case DLM_MSG_GRANT:
3979 case DLM_MSG_BAST:
3980 if (!is_process_copy(lkb) || lkb->lkb_nodeid != from)
3981 error = -EINVAL;
3982 break;
3983
3984 case DLM_MSG_REQUEST_REPLY:
3985 if (!is_process_copy(lkb))
3986 error = -EINVAL;
3987 else if (lkb->lkb_nodeid != -1 && lkb->lkb_nodeid != from)
3988 error = -EINVAL;
3989 break;
3990
3991 default:
3992 error = -EINVAL;
3993 }
3994
3995 if (error)
3996 log_error(lkb->lkb_resource->res_ls,
3997 "ignore invalid message %d from %d %x %x %x %d",
3998 ms->m_type, from, lkb->lkb_id, lkb->lkb_remid,
3999 lkb->lkb_flags, lkb->lkb_nodeid);
4000 return error;
4001 }
4002
4003 static void send_repeat_remove(struct dlm_ls *ls, char *ms_name, int len)
4004 {
4005 char name[DLM_RESNAME_MAXLEN + 1];
4006 struct dlm_message *ms;
4007 struct dlm_mhandle *mh;
4008 struct dlm_rsb *r;
4009 uint32_t hash, b;
4010 int rv, dir_nodeid;
4011
4012 memset(name, 0, sizeof(name));
4013 memcpy(name, ms_name, len);
4014
4015 hash = jhash(name, len, 0);
4016 b = hash & (ls->ls_rsbtbl_size - 1);
4017
4018 dir_nodeid = dlm_hash2nodeid(ls, hash);
4019
4020 log_error(ls, "send_repeat_remove dir %d %s", dir_nodeid, name);
4021
4022 spin_lock(&ls->ls_rsbtbl[b].lock);
4023 rv = dlm_search_rsb_tree(&ls->ls_rsbtbl[b].keep, name, len, &r);
4024 if (!rv) {
4025 spin_unlock(&ls->ls_rsbtbl[b].lock);
4026 log_error(ls, "repeat_remove on keep %s", name);
4027 return;
4028 }
4029
4030 rv = dlm_search_rsb_tree(&ls->ls_rsbtbl[b].toss, name, len, &r);
4031 if (!rv) {
4032 spin_unlock(&ls->ls_rsbtbl[b].lock);
4033 log_error(ls, "repeat_remove on toss %s", name);
4034 return;
4035 }
4036
4037 /* use ls->remove_name2 to avoid conflict with shrink? */
4038
4039 spin_lock(&ls->ls_remove_spin);
4040 ls->ls_remove_len = len;
4041 memcpy(ls->ls_remove_name, name, DLM_RESNAME_MAXLEN);
4042 spin_unlock(&ls->ls_remove_spin);
4043 spin_unlock(&ls->ls_rsbtbl[b].lock);
4044
4045 rv = _create_message(ls, sizeof(struct dlm_message) + len,
4046 dir_nodeid, DLM_MSG_REMOVE, &ms, &mh);
4047 if (rv)
4048 return;
4049
4050 memcpy(ms->m_extra, name, len);
4051 ms->m_hash = hash;
4052
4053 send_message(mh, ms);
4054
4055 spin_lock(&ls->ls_remove_spin);
4056 ls->ls_remove_len = 0;
4057 memset(ls->ls_remove_name, 0, DLM_RESNAME_MAXLEN);
4058 spin_unlock(&ls->ls_remove_spin);
4059 }
4060
4061 static int receive_request(struct dlm_ls *ls, struct dlm_message *ms)
4062 {
4063 struct dlm_lkb *lkb;
4064 struct dlm_rsb *r;
4065 int from_nodeid;
4066 int error, namelen = 0;
4067
4068 from_nodeid = ms->m_header.h_nodeid;
4069
4070 error = create_lkb(ls, &lkb);
4071 if (error)
4072 goto fail;
4073
4074 receive_flags(lkb, ms);
4075 lkb->lkb_flags |= DLM_IFL_MSTCPY;
4076 error = receive_request_args(ls, lkb, ms);
4077 if (error) {
4078 __put_lkb(ls, lkb);
4079 goto fail;
4080 }
4081
4082 /* The dir node is the authority on whether we are the master
4083 for this rsb or not, so if the master sends us a request, we should
4084 recreate the rsb if we've destroyed it. This race happens when we
4085 send a remove message to the dir node at the same time that the dir
4086 node sends us a request for the rsb. */
4087
4088 namelen = receive_extralen(ms);
4089
4090 error = find_rsb(ls, ms->m_extra, namelen, from_nodeid,
4091 R_RECEIVE_REQUEST, &r);
4092 if (error) {
4093 __put_lkb(ls, lkb);
4094 goto fail;
4095 }
4096
4097 lock_rsb(r);
4098
4099 if (r->res_master_nodeid != dlm_our_nodeid()) {
4100 error = validate_master_nodeid(ls, r, from_nodeid);
4101 if (error) {
4102 unlock_rsb(r);
4103 put_rsb(r);
4104 __put_lkb(ls, lkb);
4105 goto fail;
4106 }
4107 }
4108
4109 attach_lkb(r, lkb);
4110 error = do_request(r, lkb);
4111 send_request_reply(r, lkb, error);
4112 do_request_effects(r, lkb, error);
4113
4114 unlock_rsb(r);
4115 put_rsb(r);
4116
4117 if (error == -EINPROGRESS)
4118 error = 0;
4119 if (error)
4120 dlm_put_lkb(lkb);
4121 return 0;
4122
4123 fail:
4124 /* TODO: instead of returning ENOTBLK, add the lkb to res_lookup
4125 and do this receive_request again from process_lookup_list once
4126 we get the lookup reply. This would avoid a many repeated
4127 ENOTBLK request failures when the lookup reply designating us
4128 as master is delayed. */
4129
4130 /* We could repeatedly return -EBADR here if our send_remove() is
4131 delayed in being sent/arriving/being processed on the dir node.
4132 Another node would repeatedly lookup up the master, and the dir
4133 node would continue returning our nodeid until our send_remove
4134 took effect.
4135
4136 We send another remove message in case our previous send_remove
4137 was lost/ignored/missed somehow. */
4138
4139 if (error != -ENOTBLK) {
4140 log_limit(ls, "receive_request %x from %d %d",
4141 ms->m_lkid, from_nodeid, error);
4142 }
4143
4144 if (namelen && error == -EBADR) {
4145 send_repeat_remove(ls, ms->m_extra, namelen);
4146 msleep(1000);
4147 }
4148
4149 setup_stub_lkb(ls, ms);
4150 send_request_reply(&ls->ls_stub_rsb, &ls->ls_stub_lkb, error);
4151 return error;
4152 }
4153
4154 static int receive_convert(struct dlm_ls *ls, struct dlm_message *ms)
4155 {
4156 struct dlm_lkb *lkb;
4157 struct dlm_rsb *r;
4158 int error, reply = 1;
4159
4160 error = find_lkb(ls, ms->m_remid, &lkb);
4161 if (error)
4162 goto fail;
4163
4164 if (lkb->lkb_remid != ms->m_lkid) {
4165 log_error(ls, "receive_convert %x remid %x recover_seq %llu "
4166 "remote %d %x", lkb->lkb_id, lkb->lkb_remid,
4167 (unsigned long long)lkb->lkb_recover_seq,
4168 ms->m_header.h_nodeid, ms->m_lkid);
4169 error = -ENOENT;
4170 goto fail;
4171 }
4172
4173 r = lkb->lkb_resource;
4174
4175 hold_rsb(r);
4176 lock_rsb(r);
4177
4178 error = validate_message(lkb, ms);
4179 if (error)
4180 goto out;
4181
4182 receive_flags(lkb, ms);
4183
4184 error = receive_convert_args(ls, lkb, ms);
4185 if (error) {
4186 send_convert_reply(r, lkb, error);
4187 goto out;
4188 }
4189
4190 reply = !down_conversion(lkb);
4191
4192 error = do_convert(r, lkb);
4193 if (reply)
4194 send_convert_reply(r, lkb, error);
4195 do_convert_effects(r, lkb, error);
4196 out:
4197 unlock_rsb(r);
4198 put_rsb(r);
4199 dlm_put_lkb(lkb);
4200 return 0;
4201
4202 fail:
4203 setup_stub_lkb(ls, ms);
4204 send_convert_reply(&ls->ls_stub_rsb, &ls->ls_stub_lkb, error);
4205 return error;
4206 }
4207
4208 static int receive_unlock(struct dlm_ls *ls, struct dlm_message *ms)
4209 {
4210 struct dlm_lkb *lkb;
4211 struct dlm_rsb *r;
4212 int error;
4213
4214 error = find_lkb(ls, ms->m_remid, &lkb);
4215 if (error)
4216 goto fail;
4217
4218 if (lkb->lkb_remid != ms->m_lkid) {
4219 log_error(ls, "receive_unlock %x remid %x remote %d %x",
4220 lkb->lkb_id, lkb->lkb_remid,
4221 ms->m_header.h_nodeid, ms->m_lkid);
4222 error = -ENOENT;
4223 goto fail;
4224 }
4225
4226 r = lkb->lkb_resource;
4227
4228 hold_rsb(r);
4229 lock_rsb(r);
4230
4231 error = validate_message(lkb, ms);
4232 if (error)
4233 goto out;
4234
4235 receive_flags(lkb, ms);
4236
4237 error = receive_unlock_args(ls, lkb, ms);
4238 if (error) {
4239 send_unlock_reply(r, lkb, error);
4240 goto out;
4241 }
4242
4243 error = do_unlock(r, lkb);
4244 send_unlock_reply(r, lkb, error);
4245 do_unlock_effects(r, lkb, error);
4246 out:
4247 unlock_rsb(r);
4248 put_rsb(r);
4249 dlm_put_lkb(lkb);
4250 return 0;
4251
4252 fail:
4253 setup_stub_lkb(ls, ms);
4254 send_unlock_reply(&ls->ls_stub_rsb, &ls->ls_stub_lkb, error);
4255 return error;
4256 }
4257
4258 static int receive_cancel(struct dlm_ls *ls, struct dlm_message *ms)
4259 {
4260 struct dlm_lkb *lkb;
4261 struct dlm_rsb *r;
4262 int error;
4263
4264 error = find_lkb(ls, ms->m_remid, &lkb);
4265 if (error)
4266 goto fail;
4267
4268 receive_flags(lkb, ms);
4269
4270 r = lkb->lkb_resource;
4271
4272 hold_rsb(r);
4273 lock_rsb(r);
4274
4275 error = validate_message(lkb, ms);
4276 if (error)
4277 goto out;
4278
4279 error = do_cancel(r, lkb);
4280 send_cancel_reply(r, lkb, error);
4281 do_cancel_effects(r, lkb, error);
4282 out:
4283 unlock_rsb(r);
4284 put_rsb(r);
4285 dlm_put_lkb(lkb);
4286 return 0;
4287
4288 fail:
4289 setup_stub_lkb(ls, ms);
4290 send_cancel_reply(&ls->ls_stub_rsb, &ls->ls_stub_lkb, error);
4291 return error;
4292 }
4293
4294 static int receive_grant(struct dlm_ls *ls, struct dlm_message *ms)
4295 {
4296 struct dlm_lkb *lkb;
4297 struct dlm_rsb *r;
4298 int error;
4299
4300 error = find_lkb(ls, ms->m_remid, &lkb);
4301 if (error)
4302 return error;
4303
4304 r = lkb->lkb_resource;
4305
4306 hold_rsb(r);
4307 lock_rsb(r);
4308
4309 error = validate_message(lkb, ms);
4310 if (error)
4311 goto out;
4312
4313 receive_flags_reply(lkb, ms);
4314 if (is_altmode(lkb))
4315 munge_altmode(lkb, ms);
4316 grant_lock_pc(r, lkb, ms);
4317 queue_cast(r, lkb, 0);
4318 out:
4319 unlock_rsb(r);
4320 put_rsb(r);
4321 dlm_put_lkb(lkb);
4322 return 0;
4323 }
4324
4325 static int receive_bast(struct dlm_ls *ls, struct dlm_message *ms)
4326 {
4327 struct dlm_lkb *lkb;
4328 struct dlm_rsb *r;
4329 int error;
4330
4331 error = find_lkb(ls, ms->m_remid, &lkb);
4332 if (error)
4333 return error;
4334
4335 r = lkb->lkb_resource;
4336
4337 hold_rsb(r);
4338 lock_rsb(r);
4339
4340 error = validate_message(lkb, ms);
4341 if (error)
4342 goto out;
4343
4344 queue_bast(r, lkb, ms->m_bastmode);
4345 lkb->lkb_highbast = ms->m_bastmode;
4346 out:
4347 unlock_rsb(r);
4348 put_rsb(r);
4349 dlm_put_lkb(lkb);
4350 return 0;
4351 }
4352
4353 static void receive_lookup(struct dlm_ls *ls, struct dlm_message *ms)
4354 {
4355 int len, error, ret_nodeid, from_nodeid, our_nodeid;
4356
4357 from_nodeid = ms->m_header.h_nodeid;
4358 our_nodeid = dlm_our_nodeid();
4359
4360 len = receive_extralen(ms);
4361
4362 error = dlm_master_lookup(ls, from_nodeid, ms->m_extra, len, 0,
4363 &ret_nodeid, NULL);
4364
4365 /* Optimization: we're master so treat lookup as a request */
4366 if (!error && ret_nodeid == our_nodeid) {
4367 receive_request(ls, ms);
4368 return;
4369 }
4370 send_lookup_reply(ls, ms, ret_nodeid, error);
4371 }
4372
4373 static void receive_remove(struct dlm_ls *ls, struct dlm_message *ms)
4374 {
4375 char name[DLM_RESNAME_MAXLEN+1];
4376 struct dlm_rsb *r;
4377 uint32_t hash, b;
4378 int rv, len, dir_nodeid, from_nodeid;
4379
4380 from_nodeid = ms->m_header.h_nodeid;
4381
4382 len = receive_extralen(ms);
4383
4384 if (len > DLM_RESNAME_MAXLEN) {
4385 log_error(ls, "receive_remove from %d bad len %d",
4386 from_nodeid, len);
4387 return;
4388 }
4389
4390 dir_nodeid = dlm_hash2nodeid(ls, ms->m_hash);
4391 if (dir_nodeid != dlm_our_nodeid()) {
4392 log_error(ls, "receive_remove from %d bad nodeid %d",
4393 from_nodeid, dir_nodeid);
4394 return;
4395 }
4396
4397 /* Look for name on rsbtbl.toss, if it's there, kill it.
4398 If it's on rsbtbl.keep, it's being used, and we should ignore this
4399 message. This is an expected race between the dir node sending a
4400 request to the master node at the same time as the master node sends
4401 a remove to the dir node. The resolution to that race is for the
4402 dir node to ignore the remove message, and the master node to
4403 recreate the master rsb when it gets a request from the dir node for
4404 an rsb it doesn't have. */
4405
4406 memset(name, 0, sizeof(name));
4407 memcpy(name, ms->m_extra, len);
4408
4409 hash = jhash(name, len, 0);
4410 b = hash & (ls->ls_rsbtbl_size - 1);
4411
4412 spin_lock(&ls->ls_rsbtbl[b].lock);
4413
4414 rv = dlm_search_rsb_tree(&ls->ls_rsbtbl[b].toss, name, len, &r);
4415 if (rv) {
4416 /* verify the rsb is on keep list per comment above */
4417 rv = dlm_search_rsb_tree(&ls->ls_rsbtbl[b].keep, name, len, &r);
4418 if (rv) {
4419 /* should not happen */
4420 log_error(ls, "receive_remove from %d not found %s",
4421 from_nodeid, name);
4422 spin_unlock(&ls->ls_rsbtbl[b].lock);
4423 return;
4424 }
4425 if (r->res_master_nodeid != from_nodeid) {
4426 /* should not happen */
4427 log_error(ls, "receive_remove keep from %d master %d",
4428 from_nodeid, r->res_master_nodeid);
4429 dlm_print_rsb(r);
4430 spin_unlock(&ls->ls_rsbtbl[b].lock);
4431 return;
4432 }
4433
4434 log_debug(ls, "receive_remove from %d master %d first %x %s",
4435 from_nodeid, r->res_master_nodeid, r->res_first_lkid,
4436 name);
4437 spin_unlock(&ls->ls_rsbtbl[b].lock);
4438 return;
4439 }
4440
4441 if (r->res_master_nodeid != from_nodeid) {
4442 log_error(ls, "receive_remove toss from %d master %d",
4443 from_nodeid, r->res_master_nodeid);
4444 dlm_print_rsb(r);
4445 spin_unlock(&ls->ls_rsbtbl[b].lock);
4446 return;
4447 }
4448
4449 if (kref_put(&r->res_ref, kill_rsb)) {
4450 rb_erase(&r->res_hashnode, &ls->ls_rsbtbl[b].toss);
4451 spin_unlock(&ls->ls_rsbtbl[b].lock);
4452 dlm_free_rsb(r);
4453 } else {
4454 log_error(ls, "receive_remove from %d rsb ref error",
4455 from_nodeid);
4456 dlm_print_rsb(r);
4457 spin_unlock(&ls->ls_rsbtbl[b].lock);
4458 }
4459 }
4460
4461 static void receive_purge(struct dlm_ls *ls, struct dlm_message *ms)
4462 {
4463 do_purge(ls, ms->m_nodeid, ms->m_pid);
4464 }
4465
4466 static int receive_request_reply(struct dlm_ls *ls, struct dlm_message *ms)
4467 {
4468 struct dlm_lkb *lkb;
4469 struct dlm_rsb *r;
4470 int error, mstype, result;
4471 int from_nodeid = ms->m_header.h_nodeid;
4472
4473 error = find_lkb(ls, ms->m_remid, &lkb);
4474 if (error)
4475 return error;
4476
4477 r = lkb->lkb_resource;
4478 hold_rsb(r);
4479 lock_rsb(r);
4480
4481 error = validate_message(lkb, ms);
4482 if (error)
4483 goto out;
4484
4485 mstype = lkb->lkb_wait_type;
4486 error = remove_from_waiters(lkb, DLM_MSG_REQUEST_REPLY);
4487 if (error) {
4488 log_error(ls, "receive_request_reply %x remote %d %x result %d",
4489 lkb->lkb_id, from_nodeid, ms->m_lkid, ms->m_result);
4490 dlm_dump_rsb(r);
4491 goto out;
4492 }
4493
4494 /* Optimization: the dir node was also the master, so it took our
4495 lookup as a request and sent request reply instead of lookup reply */
4496 if (mstype == DLM_MSG_LOOKUP) {
4497 r->res_master_nodeid = from_nodeid;
4498 r->res_nodeid = from_nodeid;
4499 lkb->lkb_nodeid = from_nodeid;
4500 }
4501
4502 /* this is the value returned from do_request() on the master */
4503 result = ms->m_result;
4504
4505 switch (result) {
4506 case -EAGAIN:
4507 /* request would block (be queued) on remote master */
4508 queue_cast(r, lkb, -EAGAIN);
4509 confirm_master(r, -EAGAIN);
4510 unhold_lkb(lkb); /* undoes create_lkb() */
4511 break;
4512
4513 case -EINPROGRESS:
4514 case 0:
4515 /* request was queued or granted on remote master */
4516 receive_flags_reply(lkb, ms);
4517 lkb->lkb_remid = ms->m_lkid;
4518 if (is_altmode(lkb))
4519 munge_altmode(lkb, ms);
4520 if (result) {
4521 add_lkb(r, lkb, DLM_LKSTS_WAITING);
4522 add_timeout(lkb);
4523 } else {
4524 grant_lock_pc(r, lkb, ms);
4525 queue_cast(r, lkb, 0);
4526 }
4527 confirm_master(r, result);
4528 break;
4529
4530 case -EBADR:
4531 case -ENOTBLK:
4532 /* find_rsb failed to find rsb or rsb wasn't master */
4533 log_limit(ls, "receive_request_reply %x from %d %d "
4534 "master %d dir %d first %x %s", lkb->lkb_id,
4535 from_nodeid, result, r->res_master_nodeid,
4536 r->res_dir_nodeid, r->res_first_lkid, r->res_name);
4537
4538 if (r->res_dir_nodeid != dlm_our_nodeid() &&
4539 r->res_master_nodeid != dlm_our_nodeid()) {
4540 /* cause _request_lock->set_master->send_lookup */
4541 r->res_master_nodeid = 0;
4542 r->res_nodeid = -1;
4543 lkb->lkb_nodeid = -1;
4544 }
4545
4546 if (is_overlap(lkb)) {
4547 /* we'll ignore error in cancel/unlock reply */
4548 queue_cast_overlap(r, lkb);
4549 confirm_master(r, result);
4550 unhold_lkb(lkb); /* undoes create_lkb() */
4551 } else {
4552 _request_lock(r, lkb);
4553
4554 if (r->res_master_nodeid == dlm_our_nodeid())
4555 confirm_master(r, 0);
4556 }
4557 break;
4558
4559 default:
4560 log_error(ls, "receive_request_reply %x error %d",
4561 lkb->lkb_id, result);
4562 }
4563
4564 if (is_overlap_unlock(lkb) && (result == 0 || result == -EINPROGRESS)) {
4565 log_debug(ls, "receive_request_reply %x result %d unlock",
4566 lkb->lkb_id, result);
4567 lkb->lkb_flags &= ~DLM_IFL_OVERLAP_UNLOCK;
4568 lkb->lkb_flags &= ~DLM_IFL_OVERLAP_CANCEL;
4569 send_unlock(r, lkb);
4570 } else if (is_overlap_cancel(lkb) && (result == -EINPROGRESS)) {
4571 log_debug(ls, "receive_request_reply %x cancel", lkb->lkb_id);
4572 lkb->lkb_flags &= ~DLM_IFL_OVERLAP_UNLOCK;
4573 lkb->lkb_flags &= ~DLM_IFL_OVERLAP_CANCEL;
4574 send_cancel(r, lkb);
4575 } else {
4576 lkb->lkb_flags &= ~DLM_IFL_OVERLAP_CANCEL;
4577 lkb->lkb_flags &= ~DLM_IFL_OVERLAP_UNLOCK;
4578 }
4579 out:
4580 unlock_rsb(r);
4581 put_rsb(r);
4582 dlm_put_lkb(lkb);
4583 return 0;
4584 }
4585
4586 static void __receive_convert_reply(struct dlm_rsb *r, struct dlm_lkb *lkb,
4587 struct dlm_message *ms)
4588 {
4589 /* this is the value returned from do_convert() on the master */
4590 switch (ms->m_result) {
4591 case -EAGAIN:
4592 /* convert would block (be queued) on remote master */
4593 queue_cast(r, lkb, -EAGAIN);
4594 break;
4595
4596 case -EDEADLK:
4597 receive_flags_reply(lkb, ms);
4598 revert_lock_pc(r, lkb);
4599 queue_cast(r, lkb, -EDEADLK);
4600 break;
4601
4602 case -EINPROGRESS:
4603 /* convert was queued on remote master */
4604 receive_flags_reply(lkb, ms);
4605 if (is_demoted(lkb))
4606 munge_demoted(lkb);
4607 del_lkb(r, lkb);
4608 add_lkb(r, lkb, DLM_LKSTS_CONVERT);
4609 add_timeout(lkb);
4610 break;
4611
4612 case 0:
4613 /* convert was granted on remote master */
4614 receive_flags_reply(lkb, ms);
4615 if (is_demoted(lkb))
4616 munge_demoted(lkb);
4617 grant_lock_pc(r, lkb, ms);
4618 queue_cast(r, lkb, 0);
4619 break;
4620
4621 default:
4622 log_error(r->res_ls, "receive_convert_reply %x remote %d %x %d",
4623 lkb->lkb_id, ms->m_header.h_nodeid, ms->m_lkid,
4624 ms->m_result);
4625 dlm_print_rsb(r);
4626 dlm_print_lkb(lkb);
4627 }
4628 }
4629
4630 static void _receive_convert_reply(struct dlm_lkb *lkb, struct dlm_message *ms)
4631 {
4632 struct dlm_rsb *r = lkb->lkb_resource;
4633 int error;
4634
4635 hold_rsb(r);
4636 lock_rsb(r);
4637
4638 error = validate_message(lkb, ms);
4639 if (error)
4640 goto out;
4641
4642 /* stub reply can happen with waiters_mutex held */
4643 error = remove_from_waiters_ms(lkb, ms);
4644 if (error)
4645 goto out;
4646
4647 __receive_convert_reply(r, lkb, ms);
4648 out:
4649 unlock_rsb(r);
4650 put_rsb(r);
4651 }
4652
4653 static int receive_convert_reply(struct dlm_ls *ls, struct dlm_message *ms)
4654 {
4655 struct dlm_lkb *lkb;
4656 int error;
4657
4658 error = find_lkb(ls, ms->m_remid, &lkb);
4659 if (error)
4660 return error;
4661
4662 _receive_convert_reply(lkb, ms);
4663 dlm_put_lkb(lkb);
4664 return 0;
4665 }
4666
4667 static void _receive_unlock_reply(struct dlm_lkb *lkb, struct dlm_message *ms)
4668 {
4669 struct dlm_rsb *r = lkb->lkb_resource;
4670 int error;
4671
4672 hold_rsb(r);
4673 lock_rsb(r);
4674
4675 error = validate_message(lkb, ms);
4676 if (error)
4677 goto out;
4678
4679 /* stub reply can happen with waiters_mutex held */
4680 error = remove_from_waiters_ms(lkb, ms);
4681 if (error)
4682 goto out;
4683
4684 /* this is the value returned from do_unlock() on the master */
4685
4686 switch (ms->m_result) {
4687 case -DLM_EUNLOCK:
4688 receive_flags_reply(lkb, ms);
4689 remove_lock_pc(r, lkb);
4690 queue_cast(r, lkb, -DLM_EUNLOCK);
4691 break;
4692 case -ENOENT:
4693 break;
4694 default:
4695 log_error(r->res_ls, "receive_unlock_reply %x error %d",
4696 lkb->lkb_id, ms->m_result);
4697 }
4698 out:
4699 unlock_rsb(r);
4700 put_rsb(r);
4701 }
4702
4703 static int receive_unlock_reply(struct dlm_ls *ls, struct dlm_message *ms)
4704 {
4705 struct dlm_lkb *lkb;
4706 int error;
4707
4708 error = find_lkb(ls, ms->m_remid, &lkb);
4709 if (error)
4710 return error;
4711
4712 _receive_unlock_reply(lkb, ms);
4713 dlm_put_lkb(lkb);
4714 return 0;
4715 }
4716
4717 static void _receive_cancel_reply(struct dlm_lkb *lkb, struct dlm_message *ms)
4718 {
4719 struct dlm_rsb *r = lkb->lkb_resource;
4720 int error;
4721
4722 hold_rsb(r);
4723 lock_rsb(r);
4724
4725 error = validate_message(lkb, ms);
4726 if (error)
4727 goto out;
4728
4729 /* stub reply can happen with waiters_mutex held */
4730 error = remove_from_waiters_ms(lkb, ms);
4731 if (error)
4732 goto out;
4733
4734 /* this is the value returned from do_cancel() on the master */
4735
4736 switch (ms->m_result) {
4737 case -DLM_ECANCEL:
4738 receive_flags_reply(lkb, ms);
4739 revert_lock_pc(r, lkb);
4740 queue_cast(r, lkb, -DLM_ECANCEL);
4741 break;
4742 case 0:
4743 break;
4744 default:
4745 log_error(r->res_ls, "receive_cancel_reply %x error %d",
4746 lkb->lkb_id, ms->m_result);
4747 }
4748 out:
4749 unlock_rsb(r);
4750 put_rsb(r);
4751 }
4752
4753 static int receive_cancel_reply(struct dlm_ls *ls, struct dlm_message *ms)
4754 {
4755 struct dlm_lkb *lkb;
4756 int error;
4757
4758 error = find_lkb(ls, ms->m_remid, &lkb);
4759 if (error)
4760 return error;
4761
4762 _receive_cancel_reply(lkb, ms);
4763 dlm_put_lkb(lkb);
4764 return 0;
4765 }
4766
4767 static void receive_lookup_reply(struct dlm_ls *ls, struct dlm_message *ms)
4768 {
4769 struct dlm_lkb *lkb;
4770 struct dlm_rsb *r;
4771 int error, ret_nodeid;
4772 int do_lookup_list = 0;
4773
4774 error = find_lkb(ls, ms->m_lkid, &lkb);
4775 if (error) {
4776 log_error(ls, "receive_lookup_reply no lkid %x", ms->m_lkid);
4777 return;
4778 }
4779
4780 /* ms->m_result is the value returned by dlm_master_lookup on dir node
4781 FIXME: will a non-zero error ever be returned? */
4782
4783 r = lkb->lkb_resource;
4784 hold_rsb(r);
4785 lock_rsb(r);
4786
4787 error = remove_from_waiters(lkb, DLM_MSG_LOOKUP_REPLY);
4788 if (error)
4789 goto out;
4790
4791 ret_nodeid = ms->m_nodeid;
4792
4793 /* We sometimes receive a request from the dir node for this
4794 rsb before we've received the dir node's loookup_reply for it.
4795 The request from the dir node implies we're the master, so we set
4796 ourself as master in receive_request_reply, and verify here that
4797 we are indeed the master. */
4798
4799 if (r->res_master_nodeid && (r->res_master_nodeid != ret_nodeid)) {
4800 /* This should never happen */
4801 log_error(ls, "receive_lookup_reply %x from %d ret %d "
4802 "master %d dir %d our %d first %x %s",
4803 lkb->lkb_id, ms->m_header.h_nodeid, ret_nodeid,
4804 r->res_master_nodeid, r->res_dir_nodeid,
4805 dlm_our_nodeid(), r->res_first_lkid, r->res_name);
4806 }
4807
4808 if (ret_nodeid == dlm_our_nodeid()) {
4809 r->res_master_nodeid = ret_nodeid;
4810 r->res_nodeid = 0;
4811 do_lookup_list = 1;
4812 r->res_first_lkid = 0;
4813 } else if (ret_nodeid == -1) {
4814 /* the remote node doesn't believe it's the dir node */
4815 log_error(ls, "receive_lookup_reply %x from %d bad ret_nodeid",
4816 lkb->lkb_id, ms->m_header.h_nodeid);
4817 r->res_master_nodeid = 0;
4818 r->res_nodeid = -1;
4819 lkb->lkb_nodeid = -1;
4820 } else {
4821 /* set_master() will set lkb_nodeid from r */
4822 r->res_master_nodeid = ret_nodeid;
4823 r->res_nodeid = ret_nodeid;
4824 }
4825
4826 if (is_overlap(lkb)) {
4827 log_debug(ls, "receive_lookup_reply %x unlock %x",
4828 lkb->lkb_id, lkb->lkb_flags);
4829 queue_cast_overlap(r, lkb);
4830 unhold_lkb(lkb); /* undoes create_lkb() */
4831 goto out_list;
4832 }
4833
4834 _request_lock(r, lkb);
4835
4836 out_list:
4837 if (do_lookup_list)
4838 process_lookup_list(r);
4839 out:
4840 unlock_rsb(r);
4841 put_rsb(r);
4842 dlm_put_lkb(lkb);
4843 }
4844
4845 static void _receive_message(struct dlm_ls *ls, struct dlm_message *ms,
4846 uint32_t saved_seq)
4847 {
4848 int error = 0, noent = 0;
4849
4850 if (!dlm_is_member(ls, ms->m_header.h_nodeid)) {
4851 log_limit(ls, "receive %d from non-member %d %x %x %d",
4852 ms->m_type, ms->m_header.h_nodeid, ms->m_lkid,
4853 ms->m_remid, ms->m_result);
4854 return;
4855 }
4856
4857 switch (ms->m_type) {
4858
4859 /* messages sent to a master node */
4860
4861 case DLM_MSG_REQUEST:
4862 error = receive_request(ls, ms);
4863 break;
4864
4865 case DLM_MSG_CONVERT:
4866 error = receive_convert(ls, ms);
4867 break;
4868
4869 case DLM_MSG_UNLOCK:
4870 error = receive_unlock(ls, ms);
4871 break;
4872
4873 case DLM_MSG_CANCEL:
4874 noent = 1;
4875 error = receive_cancel(ls, ms);
4876 break;
4877
4878 /* messages sent from a master node (replies to above) */
4879
4880 case DLM_MSG_REQUEST_REPLY:
4881 error = receive_request_reply(ls, ms);
4882 break;
4883
4884 case DLM_MSG_CONVERT_REPLY:
4885 error = receive_convert_reply(ls, ms);
4886 break;
4887
4888 case DLM_MSG_UNLOCK_REPLY:
4889 error = receive_unlock_reply(ls, ms);
4890 break;
4891
4892 case DLM_MSG_CANCEL_REPLY:
4893 error = receive_cancel_reply(ls, ms);
4894 break;
4895
4896 /* messages sent from a master node (only two types of async msg) */
4897
4898 case DLM_MSG_GRANT:
4899 noent = 1;
4900 error = receive_grant(ls, ms);
4901 break;
4902
4903 case DLM_MSG_BAST:
4904 noent = 1;
4905 error = receive_bast(ls, ms);
4906 break;
4907
4908 /* messages sent to a dir node */
4909
4910 case DLM_MSG_LOOKUP:
4911 receive_lookup(ls, ms);
4912 break;
4913
4914 case DLM_MSG_REMOVE:
4915 receive_remove(ls, ms);
4916 break;
4917
4918 /* messages sent from a dir node (remove has no reply) */
4919
4920 case DLM_MSG_LOOKUP_REPLY:
4921 receive_lookup_reply(ls, ms);
4922 break;
4923
4924 /* other messages */
4925
4926 case DLM_MSG_PURGE:
4927 receive_purge(ls, ms);
4928 break;
4929
4930 default:
4931 log_error(ls, "unknown message type %d", ms->m_type);
4932 }
4933
4934 /*
4935 * When checking for ENOENT, we're checking the result of
4936 * find_lkb(m_remid):
4937 *
4938 * The lock id referenced in the message wasn't found. This may
4939 * happen in normal usage for the async messages and cancel, so
4940 * only use log_debug for them.
4941 *
4942 * Some errors are expected and normal.
4943 */
4944
4945 if (error == -ENOENT && noent) {
4946 log_debug(ls, "receive %d no %x remote %d %x saved_seq %u",
4947 ms->m_type, ms->m_remid, ms->m_header.h_nodeid,
4948 ms->m_lkid, saved_seq);
4949 } else if (error == -ENOENT) {
4950 log_error(ls, "receive %d no %x remote %d %x saved_seq %u",
4951 ms->m_type, ms->m_remid, ms->m_header.h_nodeid,
4952 ms->m_lkid, saved_seq);
4953
4954 if (ms->m_type == DLM_MSG_CONVERT)
4955 dlm_dump_rsb_hash(ls, ms->m_hash);
4956 }
4957
4958 if (error == -EINVAL) {
4959 log_error(ls, "receive %d inval from %d lkid %x remid %x "
4960 "saved_seq %u",
4961 ms->m_type, ms->m_header.h_nodeid,
4962 ms->m_lkid, ms->m_remid, saved_seq);
4963 }
4964 }
4965
4966 /* If the lockspace is in recovery mode (locking stopped), then normal
4967 messages are saved on the requestqueue for processing after recovery is
4968 done. When not in recovery mode, we wait for dlm_recoverd to drain saved
4969 messages off the requestqueue before we process new ones. This occurs right
4970 after recovery completes when we transition from saving all messages on
4971 requestqueue, to processing all the saved messages, to processing new
4972 messages as they arrive. */
4973
4974 static void dlm_receive_message(struct dlm_ls *ls, struct dlm_message *ms,
4975 int nodeid)
4976 {
4977 if (dlm_locking_stopped(ls)) {
4978 /* If we were a member of this lockspace, left, and rejoined,
4979 other nodes may still be sending us messages from the
4980 lockspace generation before we left. */
4981 if (!ls->ls_generation) {
4982 log_limit(ls, "receive %d from %d ignore old gen",
4983 ms->m_type, nodeid);
4984 return;
4985 }
4986
4987 dlm_add_requestqueue(ls, nodeid, ms);
4988 } else {
4989 dlm_wait_requestqueue(ls);
4990 _receive_message(ls, ms, 0);
4991 }
4992 }
4993
4994 /* This is called by dlm_recoverd to process messages that were saved on
4995 the requestqueue. */
4996
4997 void dlm_receive_message_saved(struct dlm_ls *ls, struct dlm_message *ms,
4998 uint32_t saved_seq)
4999 {
5000 _receive_message(ls, ms, saved_seq);
5001 }
5002
5003 /* This is called by the midcomms layer when something is received for
5004 the lockspace. It could be either a MSG (normal message sent as part of
5005 standard locking activity) or an RCOM (recovery message sent as part of
5006 lockspace recovery). */
5007
5008 void dlm_receive_buffer(union dlm_packet *p, int nodeid)
5009 {
5010 struct dlm_header *hd = &p->header;
5011 struct dlm_ls *ls;
5012 int type = 0;
5013
5014 switch (hd->h_cmd) {
5015 case DLM_MSG:
5016 dlm_message_in(&p->message);
5017 type = p->message.m_type;
5018 break;
5019 case DLM_RCOM:
5020 dlm_rcom_in(&p->rcom);
5021 type = p->rcom.rc_type;
5022 break;
5023 default:
5024 log_print("invalid h_cmd %d from %u", hd->h_cmd, nodeid);
5025 return;
5026 }
5027
5028 if (hd->h_nodeid != nodeid) {
5029 log_print("invalid h_nodeid %d from %d lockspace %x",
5030 hd->h_nodeid, nodeid, hd->h_lockspace);
5031 return;
5032 }
5033
5034 ls = dlm_find_lockspace_global(hd->h_lockspace);
5035 if (!ls) {
5036 if (dlm_config.ci_log_debug) {
5037 printk_ratelimited(KERN_DEBUG "dlm: invalid lockspace "
5038 "%u from %d cmd %d type %d\n",
5039 hd->h_lockspace, nodeid, hd->h_cmd, type);
5040 }
5041
5042 if (hd->h_cmd == DLM_RCOM && type == DLM_RCOM_STATUS)
5043 dlm_send_ls_not_ready(nodeid, &p->rcom);
5044 return;
5045 }
5046
5047 /* this rwsem allows dlm_ls_stop() to wait for all dlm_recv threads to
5048 be inactive (in this ls) before transitioning to recovery mode */
5049
5050 down_read(&ls->ls_recv_active);
5051 if (hd->h_cmd == DLM_MSG)
5052 dlm_receive_message(ls, &p->message, nodeid);
5053 else
5054 dlm_receive_rcom(ls, &p->rcom, nodeid);
5055 up_read(&ls->ls_recv_active);
5056
5057 dlm_put_lockspace(ls);
5058 }
5059
5060 static void recover_convert_waiter(struct dlm_ls *ls, struct dlm_lkb *lkb,
5061 struct dlm_message *ms_stub)
5062 {
5063 if (middle_conversion(lkb)) {
5064 hold_lkb(lkb);
5065 memset(ms_stub, 0, sizeof(struct dlm_message));
5066 ms_stub->m_flags = DLM_IFL_STUB_MS;
5067 ms_stub->m_type = DLM_MSG_CONVERT_REPLY;
5068 ms_stub->m_result = -EINPROGRESS;
5069 ms_stub->m_header.h_nodeid = lkb->lkb_nodeid;
5070 _receive_convert_reply(lkb, ms_stub);
5071
5072 /* Same special case as in receive_rcom_lock_args() */
5073 lkb->lkb_grmode = DLM_LOCK_IV;
5074 rsb_set_flag(lkb->lkb_resource, RSB_RECOVER_CONVERT);
5075 unhold_lkb(lkb);
5076
5077 } else if (lkb->lkb_rqmode >= lkb->lkb_grmode) {
5078 lkb->lkb_flags |= DLM_IFL_RESEND;
5079 }
5080
5081 /* lkb->lkb_rqmode < lkb->lkb_grmode shouldn't happen since down
5082 conversions are async; there's no reply from the remote master */
5083 }
5084
5085 /* A waiting lkb needs recovery if the master node has failed, or
5086 the master node is changing (only when no directory is used) */
5087
5088 static int waiter_needs_recovery(struct dlm_ls *ls, struct dlm_lkb *lkb,
5089 int dir_nodeid)
5090 {
5091 if (dlm_no_directory(ls))
5092 return 1;
5093
5094 if (dlm_is_removed(ls, lkb->lkb_wait_nodeid))
5095 return 1;
5096
5097 return 0;
5098 }
5099
5100 /* Recovery for locks that are waiting for replies from nodes that are now
5101 gone. We can just complete unlocks and cancels by faking a reply from the
5102 dead node. Requests and up-conversions we flag to be resent after
5103 recovery. Down-conversions can just be completed with a fake reply like
5104 unlocks. Conversions between PR and CW need special attention. */
5105
5106 void dlm_recover_waiters_pre(struct dlm_ls *ls)
5107 {
5108 struct dlm_lkb *lkb, *safe;
5109 struct dlm_message *ms_stub;
5110 int wait_type, stub_unlock_result, stub_cancel_result;
5111 int dir_nodeid;
5112
5113 ms_stub = kmalloc(sizeof(struct dlm_message), GFP_KERNEL);
5114 if (!ms_stub) {
5115 log_error(ls, "dlm_recover_waiters_pre no mem");
5116 return;
5117 }
5118
5119 mutex_lock(&ls->ls_waiters_mutex);
5120
5121 list_for_each_entry_safe(lkb, safe, &ls->ls_waiters, lkb_wait_reply) {
5122
5123 dir_nodeid = dlm_dir_nodeid(lkb->lkb_resource);
5124
5125 /* exclude debug messages about unlocks because there can be so
5126 many and they aren't very interesting */
5127
5128 if (lkb->lkb_wait_type != DLM_MSG_UNLOCK) {
5129 log_debug(ls, "waiter %x remote %x msg %d r_nodeid %d "
5130 "lkb_nodeid %d wait_nodeid %d dir_nodeid %d",
5131 lkb->lkb_id,
5132 lkb->lkb_remid,
5133 lkb->lkb_wait_type,
5134 lkb->lkb_resource->res_nodeid,
5135 lkb->lkb_nodeid,
5136 lkb->lkb_wait_nodeid,
5137 dir_nodeid);
5138 }
5139
5140 /* all outstanding lookups, regardless of destination will be
5141 resent after recovery is done */
5142
5143 if (lkb->lkb_wait_type == DLM_MSG_LOOKUP) {
5144 lkb->lkb_flags |= DLM_IFL_RESEND;
5145 continue;
5146 }
5147
5148 if (!waiter_needs_recovery(ls, lkb, dir_nodeid))
5149 continue;
5150
5151 wait_type = lkb->lkb_wait_type;
5152 stub_unlock_result = -DLM_EUNLOCK;
5153 stub_cancel_result = -DLM_ECANCEL;
5154
5155 /* Main reply may have been received leaving a zero wait_type,
5156 but a reply for the overlapping op may not have been
5157 received. In that case we need to fake the appropriate
5158 reply for the overlap op. */
5159
5160 if (!wait_type) {
5161 if (is_overlap_cancel(lkb)) {
5162 wait_type = DLM_MSG_CANCEL;
5163 if (lkb->lkb_grmode == DLM_LOCK_IV)
5164 stub_cancel_result = 0;
5165 }
5166 if (is_overlap_unlock(lkb)) {
5167 wait_type = DLM_MSG_UNLOCK;
5168 if (lkb->lkb_grmode == DLM_LOCK_IV)
5169 stub_unlock_result = -ENOENT;
5170 }
5171
5172 log_debug(ls, "rwpre overlap %x %x %d %d %d",
5173 lkb->lkb_id, lkb->lkb_flags, wait_type,
5174 stub_cancel_result, stub_unlock_result);
5175 }
5176
5177 switch (wait_type) {
5178
5179 case DLM_MSG_REQUEST:
5180 lkb->lkb_flags |= DLM_IFL_RESEND;
5181 break;
5182
5183 case DLM_MSG_CONVERT:
5184 recover_convert_waiter(ls, lkb, ms_stub);
5185 break;
5186
5187 case DLM_MSG_UNLOCK:
5188 hold_lkb(lkb);
5189 memset(ms_stub, 0, sizeof(struct dlm_message));
5190 ms_stub->m_flags = DLM_IFL_STUB_MS;
5191 ms_stub->m_type = DLM_MSG_UNLOCK_REPLY;
5192 ms_stub->m_result = stub_unlock_result;
5193 ms_stub->m_header.h_nodeid = lkb->lkb_nodeid;
5194 _receive_unlock_reply(lkb, ms_stub);
5195 dlm_put_lkb(lkb);
5196 break;
5197
5198 case DLM_MSG_CANCEL:
5199 hold_lkb(lkb);
5200 memset(ms_stub, 0, sizeof(struct dlm_message));
5201 ms_stub->m_flags = DLM_IFL_STUB_MS;
5202 ms_stub->m_type = DLM_MSG_CANCEL_REPLY;
5203 ms_stub->m_result = stub_cancel_result;
5204 ms_stub->m_header.h_nodeid = lkb->lkb_nodeid;
5205 _receive_cancel_reply(lkb, ms_stub);
5206 dlm_put_lkb(lkb);
5207 break;
5208
5209 default:
5210 log_error(ls, "invalid lkb wait_type %d %d",
5211 lkb->lkb_wait_type, wait_type);
5212 }
5213 schedule();
5214 }
5215 mutex_unlock(&ls->ls_waiters_mutex);
5216 kfree(ms_stub);
5217 }
5218
5219 static struct dlm_lkb *find_resend_waiter(struct dlm_ls *ls)
5220 {
5221 struct dlm_lkb *lkb;
5222 int found = 0;
5223
5224 mutex_lock(&ls->ls_waiters_mutex);
5225 list_for_each_entry(lkb, &ls->ls_waiters, lkb_wait_reply) {
5226 if (lkb->lkb_flags & DLM_IFL_RESEND) {
5227 hold_lkb(lkb);
5228 found = 1;
5229 break;
5230 }
5231 }
5232 mutex_unlock(&ls->ls_waiters_mutex);
5233
5234 if (!found)
5235 lkb = NULL;
5236 return lkb;
5237 }
5238
5239 /* Deal with lookups and lkb's marked RESEND from _pre. We may now be the
5240 master or dir-node for r. Processing the lkb may result in it being placed
5241 back on waiters. */
5242
5243 /* We do this after normal locking has been enabled and any saved messages
5244 (in requestqueue) have been processed. We should be confident that at
5245 this point we won't get or process a reply to any of these waiting
5246 operations. But, new ops may be coming in on the rsbs/locks here from
5247 userspace or remotely. */
5248
5249 /* there may have been an overlap unlock/cancel prior to recovery or after
5250 recovery. if before, the lkb may still have a pos wait_count; if after, the
5251 overlap flag would just have been set and nothing new sent. we can be
5252 confident here than any replies to either the initial op or overlap ops
5253 prior to recovery have been received. */
5254
5255 int dlm_recover_waiters_post(struct dlm_ls *ls)
5256 {
5257 struct dlm_lkb *lkb;
5258 struct dlm_rsb *r;
5259 int error = 0, mstype, err, oc, ou;
5260
5261 while (1) {
5262 if (dlm_locking_stopped(ls)) {
5263 log_debug(ls, "recover_waiters_post aborted");
5264 error = -EINTR;
5265 break;
5266 }
5267
5268 lkb = find_resend_waiter(ls);
5269 if (!lkb)
5270 break;
5271
5272 r = lkb->lkb_resource;
5273 hold_rsb(r);
5274 lock_rsb(r);
5275
5276 mstype = lkb->lkb_wait_type;
5277 oc = is_overlap_cancel(lkb);
5278 ou = is_overlap_unlock(lkb);
5279 err = 0;
5280
5281 log_debug(ls, "waiter %x remote %x msg %d r_nodeid %d "
5282 "lkb_nodeid %d wait_nodeid %d dir_nodeid %d "
5283 "overlap %d %d", lkb->lkb_id, lkb->lkb_remid, mstype,
5284 r->res_nodeid, lkb->lkb_nodeid, lkb->lkb_wait_nodeid,
5285 dlm_dir_nodeid(r), oc, ou);
5286
5287 /* At this point we assume that we won't get a reply to any
5288 previous op or overlap op on this lock. First, do a big
5289 remove_from_waiters() for all previous ops. */
5290
5291 lkb->lkb_flags &= ~DLM_IFL_RESEND;
5292 lkb->lkb_flags &= ~DLM_IFL_OVERLAP_UNLOCK;
5293 lkb->lkb_flags &= ~DLM_IFL_OVERLAP_CANCEL;
5294 lkb->lkb_wait_type = 0;
5295 lkb->lkb_wait_count = 0;
5296 mutex_lock(&ls->ls_waiters_mutex);
5297 list_del_init(&lkb->lkb_wait_reply);
5298 mutex_unlock(&ls->ls_waiters_mutex);
5299 unhold_lkb(lkb); /* for waiters list */
5300
5301 if (oc || ou) {
5302 /* do an unlock or cancel instead of resending */
5303 switch (mstype) {
5304 case DLM_MSG_LOOKUP:
5305 case DLM_MSG_REQUEST:
5306 queue_cast(r, lkb, ou ? -DLM_EUNLOCK :
5307 -DLM_ECANCEL);
5308 unhold_lkb(lkb); /* undoes create_lkb() */
5309 break;
5310 case DLM_MSG_CONVERT:
5311 if (oc) {
5312 queue_cast(r, lkb, -DLM_ECANCEL);
5313 } else {
5314 lkb->lkb_exflags |= DLM_LKF_FORCEUNLOCK;
5315 _unlock_lock(r, lkb);
5316 }
5317 break;
5318 default:
5319 err = 1;
5320 }
5321 } else {
5322 switch (mstype) {
5323 case DLM_MSG_LOOKUP:
5324 case DLM_MSG_REQUEST:
5325 _request_lock(r, lkb);
5326 if (is_master(r))
5327 confirm_master(r, 0);
5328 break;
5329 case DLM_MSG_CONVERT:
5330 _convert_lock(r, lkb);
5331 break;
5332 default:
5333 err = 1;
5334 }
5335 }
5336
5337 if (err) {
5338 log_error(ls, "waiter %x msg %d r_nodeid %d "
5339 "dir_nodeid %d overlap %d %d",
5340 lkb->lkb_id, mstype, r->res_nodeid,
5341 dlm_dir_nodeid(r), oc, ou);
5342 }
5343 unlock_rsb(r);
5344 put_rsb(r);
5345 dlm_put_lkb(lkb);
5346 }
5347
5348 return error;
5349 }
5350
5351 static void purge_mstcpy_list(struct dlm_ls *ls, struct dlm_rsb *r,
5352 struct list_head *list)
5353 {
5354 struct dlm_lkb *lkb, *safe;
5355
5356 list_for_each_entry_safe(lkb, safe, list, lkb_statequeue) {
5357 if (!is_master_copy(lkb))
5358 continue;
5359
5360 /* don't purge lkbs we've added in recover_master_copy for
5361 the current recovery seq */
5362
5363 if (lkb->lkb_recover_seq == ls->ls_recover_seq)
5364 continue;
5365
5366 del_lkb(r, lkb);
5367
5368 /* this put should free the lkb */
5369 if (!dlm_put_lkb(lkb))
5370 log_error(ls, "purged mstcpy lkb not released");
5371 }
5372 }
5373
5374 void dlm_purge_mstcpy_locks(struct dlm_rsb *r)
5375 {
5376 struct dlm_ls *ls = r->res_ls;
5377
5378 purge_mstcpy_list(ls, r, &r->res_grantqueue);
5379 purge_mstcpy_list(ls, r, &r->res_convertqueue);
5380 purge_mstcpy_list(ls, r, &r->res_waitqueue);
5381 }
5382
5383 static void purge_dead_list(struct dlm_ls *ls, struct dlm_rsb *r,
5384 struct list_head *list,
5385 int nodeid_gone, unsigned int *count)
5386 {
5387 struct dlm_lkb *lkb, *safe;
5388
5389 list_for_each_entry_safe(lkb, safe, list, lkb_statequeue) {
5390 if (!is_master_copy(lkb))
5391 continue;
5392
5393 if ((lkb->lkb_nodeid == nodeid_gone) ||
5394 dlm_is_removed(ls, lkb->lkb_nodeid)) {
5395
5396 /* tell recover_lvb to invalidate the lvb
5397 because a node holding EX/PW failed */
5398 if ((lkb->lkb_exflags & DLM_LKF_VALBLK) &&
5399 (lkb->lkb_grmode >= DLM_LOCK_PW)) {
5400 rsb_set_flag(r, RSB_RECOVER_LVB_INVAL);
5401 }
5402
5403 del_lkb(r, lkb);
5404
5405 /* this put should free the lkb */
5406 if (!dlm_put_lkb(lkb))
5407 log_error(ls, "purged dead lkb not released");
5408
5409 rsb_set_flag(r, RSB_RECOVER_GRANT);
5410
5411 (*count)++;
5412 }
5413 }
5414 }
5415
5416 /* Get rid of locks held by nodes that are gone. */
5417
5418 void dlm_recover_purge(struct dlm_ls *ls)
5419 {
5420 struct dlm_rsb *r;
5421 struct dlm_member *memb;
5422 int nodes_count = 0;
5423 int nodeid_gone = 0;
5424 unsigned int lkb_count = 0;
5425
5426 /* cache one removed nodeid to optimize the common
5427 case of a single node removed */
5428
5429 list_for_each_entry(memb, &ls->ls_nodes_gone, list) {
5430 nodes_count++;
5431 nodeid_gone = memb->nodeid;
5432 }
5433
5434 if (!nodes_count)
5435 return;
5436
5437 down_write(&ls->ls_root_sem);
5438 list_for_each_entry(r, &ls->ls_root_list, res_root_list) {
5439 hold_rsb(r);
5440 lock_rsb(r);
5441 if (is_master(r)) {
5442 purge_dead_list(ls, r, &r->res_grantqueue,
5443 nodeid_gone, &lkb_count);
5444 purge_dead_list(ls, r, &r->res_convertqueue,
5445 nodeid_gone, &lkb_count);
5446 purge_dead_list(ls, r, &r->res_waitqueue,
5447 nodeid_gone, &lkb_count);
5448 }
5449 unlock_rsb(r);
5450 unhold_rsb(r);
5451 cond_resched();
5452 }
5453 up_write(&ls->ls_root_sem);
5454
5455 if (lkb_count)
5456 log_debug(ls, "dlm_recover_purge %u locks for %u nodes",
5457 lkb_count, nodes_count);
5458 }
5459
5460 static struct dlm_rsb *find_grant_rsb(struct dlm_ls *ls, int bucket)
5461 {
5462 struct rb_node *n;
5463 struct dlm_rsb *r;
5464
5465 spin_lock(&ls->ls_rsbtbl[bucket].lock);
5466 for (n = rb_first(&ls->ls_rsbtbl[bucket].keep); n; n = rb_next(n)) {
5467 r = rb_entry(n, struct dlm_rsb, res_hashnode);
5468
5469 if (!rsb_flag(r, RSB_RECOVER_GRANT))
5470 continue;
5471 if (!is_master(r)) {
5472 rsb_clear_flag(r, RSB_RECOVER_GRANT);
5473 continue;
5474 }
5475 hold_rsb(r);
5476 spin_unlock(&ls->ls_rsbtbl[bucket].lock);
5477 return r;
5478 }
5479 spin_unlock(&ls->ls_rsbtbl[bucket].lock);
5480 return NULL;
5481 }
5482
5483 /*
5484 * Attempt to grant locks on resources that we are the master of.
5485 * Locks may have become grantable during recovery because locks
5486 * from departed nodes have been purged (or not rebuilt), allowing
5487 * previously blocked locks to now be granted. The subset of rsb's
5488 * we are interested in are those with lkb's on either the convert or
5489 * waiting queues.
5490 *
5491 * Simplest would be to go through each master rsb and check for non-empty
5492 * convert or waiting queues, and attempt to grant on those rsbs.
5493 * Checking the queues requires lock_rsb, though, for which we'd need
5494 * to release the rsbtbl lock. This would make iterating through all
5495 * rsb's very inefficient. So, we rely on earlier recovery routines
5496 * to set RECOVER_GRANT on any rsb's that we should attempt to grant
5497 * locks for.
5498 */
5499
5500 void dlm_recover_grant(struct dlm_ls *ls)
5501 {
5502 struct dlm_rsb *r;
5503 int bucket = 0;
5504 unsigned int count = 0;
5505 unsigned int rsb_count = 0;
5506 unsigned int lkb_count = 0;
5507
5508 while (1) {
5509 r = find_grant_rsb(ls, bucket);
5510 if (!r) {
5511 if (bucket == ls->ls_rsbtbl_size - 1)
5512 break;
5513 bucket++;
5514 continue;
5515 }
5516 rsb_count++;
5517 count = 0;
5518 lock_rsb(r);
5519 /* the RECOVER_GRANT flag is checked in the grant path */
5520 grant_pending_locks(r, &count);
5521 rsb_clear_flag(r, RSB_RECOVER_GRANT);
5522 lkb_count += count;
5523 confirm_master(r, 0);
5524 unlock_rsb(r);
5525 put_rsb(r);
5526 cond_resched();
5527 }
5528
5529 if (lkb_count)
5530 log_debug(ls, "dlm_recover_grant %u locks on %u resources",
5531 lkb_count, rsb_count);
5532 }
5533
5534 static struct dlm_lkb *search_remid_list(struct list_head *head, int nodeid,
5535 uint32_t remid)
5536 {
5537 struct dlm_lkb *lkb;
5538
5539 list_for_each_entry(lkb, head, lkb_statequeue) {
5540 if (lkb->lkb_nodeid == nodeid && lkb->lkb_remid == remid)
5541 return lkb;
5542 }
5543 return NULL;
5544 }
5545
5546 static struct dlm_lkb *search_remid(struct dlm_rsb *r, int nodeid,
5547 uint32_t remid)
5548 {
5549 struct dlm_lkb *lkb;
5550
5551 lkb = search_remid_list(&r->res_grantqueue, nodeid, remid);
5552 if (lkb)
5553 return lkb;
5554 lkb = search_remid_list(&r->res_convertqueue, nodeid, remid);
5555 if (lkb)
5556 return lkb;
5557 lkb = search_remid_list(&r->res_waitqueue, nodeid, remid);
5558 if (lkb)
5559 return lkb;
5560 return NULL;
5561 }
5562
5563 /* needs at least dlm_rcom + rcom_lock */
5564 static int receive_rcom_lock_args(struct dlm_ls *ls, struct dlm_lkb *lkb,
5565 struct dlm_rsb *r, struct dlm_rcom *rc)
5566 {
5567 struct rcom_lock *rl = (struct rcom_lock *) rc->rc_buf;
5568
5569 lkb->lkb_nodeid = rc->rc_header.h_nodeid;
5570 lkb->lkb_ownpid = le32_to_cpu(rl->rl_ownpid);
5571 lkb->lkb_remid = le32_to_cpu(rl->rl_lkid);
5572 lkb->lkb_exflags = le32_to_cpu(rl->rl_exflags);
5573 lkb->lkb_flags = le32_to_cpu(rl->rl_flags) & 0x0000FFFF;
5574 lkb->lkb_flags |= DLM_IFL_MSTCPY;
5575 lkb->lkb_lvbseq = le32_to_cpu(rl->rl_lvbseq);
5576 lkb->lkb_rqmode = rl->rl_rqmode;
5577 lkb->lkb_grmode = rl->rl_grmode;
5578 /* don't set lkb_status because add_lkb wants to itself */
5579
5580 lkb->lkb_bastfn = (rl->rl_asts & DLM_CB_BAST) ? &fake_bastfn : NULL;
5581 lkb->lkb_astfn = (rl->rl_asts & DLM_CB_CAST) ? &fake_astfn : NULL;
5582
5583 if (lkb->lkb_exflags & DLM_LKF_VALBLK) {
5584 int lvblen = rc->rc_header.h_length - sizeof(struct dlm_rcom) -
5585 sizeof(struct rcom_lock);
5586 if (lvblen > ls->ls_lvblen)
5587 return -EINVAL;
5588 lkb->lkb_lvbptr = dlm_allocate_lvb(ls);
5589 if (!lkb->lkb_lvbptr)
5590 return -ENOMEM;
5591 memcpy(lkb->lkb_lvbptr, rl->rl_lvb, lvblen);
5592 }
5593
5594 /* Conversions between PR and CW (middle modes) need special handling.
5595 The real granted mode of these converting locks cannot be determined
5596 until all locks have been rebuilt on the rsb (recover_conversion) */
5597
5598 if (rl->rl_wait_type == cpu_to_le16(DLM_MSG_CONVERT) &&
5599 middle_conversion(lkb)) {
5600 rl->rl_status = DLM_LKSTS_CONVERT;
5601 lkb->lkb_grmode = DLM_LOCK_IV;
5602 rsb_set_flag(r, RSB_RECOVER_CONVERT);
5603 }
5604
5605 return 0;
5606 }
5607
5608 /* This lkb may have been recovered in a previous aborted recovery so we need
5609 to check if the rsb already has an lkb with the given remote nodeid/lkid.
5610 If so we just send back a standard reply. If not, we create a new lkb with
5611 the given values and send back our lkid. We send back our lkid by sending
5612 back the rcom_lock struct we got but with the remid field filled in. */
5613
5614 /* needs at least dlm_rcom + rcom_lock */
5615 int dlm_recover_master_copy(struct dlm_ls *ls, struct dlm_rcom *rc)
5616 {
5617 struct rcom_lock *rl = (struct rcom_lock *) rc->rc_buf;
5618 struct dlm_rsb *r;
5619 struct dlm_lkb *lkb;
5620 uint32_t remid = 0;
5621 int from_nodeid = rc->rc_header.h_nodeid;
5622 int error;
5623
5624 if (rl->rl_parent_lkid) {
5625 error = -EOPNOTSUPP;
5626 goto out;
5627 }
5628
5629 remid = le32_to_cpu(rl->rl_lkid);
5630
5631 /* In general we expect the rsb returned to be R_MASTER, but we don't
5632 have to require it. Recovery of masters on one node can overlap
5633 recovery of locks on another node, so one node can send us MSTCPY
5634 locks before we've made ourselves master of this rsb. We can still
5635 add new MSTCPY locks that we receive here without any harm; when
5636 we make ourselves master, dlm_recover_masters() won't touch the
5637 MSTCPY locks we've received early. */
5638
5639 error = find_rsb(ls, rl->rl_name, le16_to_cpu(rl->rl_namelen),
5640 from_nodeid, R_RECEIVE_RECOVER, &r);
5641 if (error)
5642 goto out;
5643
5644 lock_rsb(r);
5645
5646 if (dlm_no_directory(ls) && (dlm_dir_nodeid(r) != dlm_our_nodeid())) {
5647 log_error(ls, "dlm_recover_master_copy remote %d %x not dir",
5648 from_nodeid, remid);
5649 error = -EBADR;
5650 goto out_unlock;
5651 }
5652
5653 lkb = search_remid(r, from_nodeid, remid);
5654 if (lkb) {
5655 error = -EEXIST;
5656 goto out_remid;
5657 }
5658
5659 error = create_lkb(ls, &lkb);
5660 if (error)
5661 goto out_unlock;
5662
5663 error = receive_rcom_lock_args(ls, lkb, r, rc);
5664 if (error) {
5665 __put_lkb(ls, lkb);
5666 goto out_unlock;
5667 }
5668
5669 attach_lkb(r, lkb);
5670 add_lkb(r, lkb, rl->rl_status);
5671 error = 0;
5672 ls->ls_recover_locks_in++;
5673
5674 if (!list_empty(&r->res_waitqueue) || !list_empty(&r->res_convertqueue))
5675 rsb_set_flag(r, RSB_RECOVER_GRANT);
5676
5677 out_remid:
5678 /* this is the new value returned to the lock holder for
5679 saving in its process-copy lkb */
5680 rl->rl_remid = cpu_to_le32(lkb->lkb_id);
5681
5682 lkb->lkb_recover_seq = ls->ls_recover_seq;
5683
5684 out_unlock:
5685 unlock_rsb(r);
5686 put_rsb(r);
5687 out:
5688 if (error && error != -EEXIST)
5689 log_debug(ls, "dlm_recover_master_copy remote %d %x error %d",
5690 from_nodeid, remid, error);
5691 rl->rl_result = cpu_to_le32(error);
5692 return error;
5693 }
5694
5695 /* needs at least dlm_rcom + rcom_lock */
5696 int dlm_recover_process_copy(struct dlm_ls *ls, struct dlm_rcom *rc)
5697 {
5698 struct rcom_lock *rl = (struct rcom_lock *) rc->rc_buf;
5699 struct dlm_rsb *r;
5700 struct dlm_lkb *lkb;
5701 uint32_t lkid, remid;
5702 int error, result;
5703
5704 lkid = le32_to_cpu(rl->rl_lkid);
5705 remid = le32_to_cpu(rl->rl_remid);
5706 result = le32_to_cpu(rl->rl_result);
5707
5708 error = find_lkb(ls, lkid, &lkb);
5709 if (error) {
5710 log_error(ls, "dlm_recover_process_copy no %x remote %d %x %d",
5711 lkid, rc->rc_header.h_nodeid, remid, result);
5712 return error;
5713 }
5714
5715 r = lkb->lkb_resource;
5716 hold_rsb(r);
5717 lock_rsb(r);
5718
5719 if (!is_process_copy(lkb)) {
5720 log_error(ls, "dlm_recover_process_copy bad %x remote %d %x %d",
5721 lkid, rc->rc_header.h_nodeid, remid, result);
5722 dlm_dump_rsb(r);
5723 unlock_rsb(r);
5724 put_rsb(r);
5725 dlm_put_lkb(lkb);
5726 return -EINVAL;
5727 }
5728
5729 switch (result) {
5730 case -EBADR:
5731 /* There's a chance the new master received our lock before
5732 dlm_recover_master_reply(), this wouldn't happen if we did
5733 a barrier between recover_masters and recover_locks. */
5734
5735 log_debug(ls, "dlm_recover_process_copy %x remote %d %x %d",
5736 lkid, rc->rc_header.h_nodeid, remid, result);
5737
5738 dlm_send_rcom_lock(r, lkb);
5739 goto out;
5740 case -EEXIST:
5741 case 0:
5742 lkb->lkb_remid = remid;
5743 break;
5744 default:
5745 log_error(ls, "dlm_recover_process_copy %x remote %d %x %d unk",
5746 lkid, rc->rc_header.h_nodeid, remid, result);
5747 }
5748
5749 /* an ack for dlm_recover_locks() which waits for replies from
5750 all the locks it sends to new masters */
5751 dlm_recovered_lock(r);
5752 out:
5753 unlock_rsb(r);
5754 put_rsb(r);
5755 dlm_put_lkb(lkb);
5756
5757 return 0;
5758 }
5759
5760 int dlm_user_request(struct dlm_ls *ls, struct dlm_user_args *ua,
5761 int mode, uint32_t flags, void *name, unsigned int namelen,
5762 unsigned long timeout_cs)
5763 {
5764 struct dlm_lkb *lkb;
5765 struct dlm_args args;
5766 int error;
5767
5768 dlm_lock_recovery(ls);
5769
5770 error = create_lkb(ls, &lkb);
5771 if (error) {
5772 kfree(ua);
5773 goto out;
5774 }
5775
5776 if (flags & DLM_LKF_VALBLK) {
5777 ua->lksb.sb_lvbptr = kzalloc(DLM_USER_LVB_LEN, GFP_NOFS);
5778 if (!ua->lksb.sb_lvbptr) {
5779 kfree(ua);
5780 __put_lkb(ls, lkb);
5781 error = -ENOMEM;
5782 goto out;
5783 }
5784 }
5785
5786 /* After ua is attached to lkb it will be freed by dlm_free_lkb().
5787 When DLM_IFL_USER is set, the dlm knows that this is a userspace
5788 lock and that lkb_astparam is the dlm_user_args structure. */
5789
5790 error = set_lock_args(mode, &ua->lksb, flags, namelen, timeout_cs,
5791 fake_astfn, ua, fake_bastfn, &args);
5792 lkb->lkb_flags |= DLM_IFL_USER;
5793
5794 if (error) {
5795 __put_lkb(ls, lkb);
5796 goto out;
5797 }
5798
5799 error = request_lock(ls, lkb, name, namelen, &args);
5800
5801 switch (error) {
5802 case 0:
5803 break;
5804 case -EINPROGRESS:
5805 error = 0;
5806 break;
5807 case -EAGAIN:
5808 error = 0;
5809 /* fall through */
5810 default:
5811 __put_lkb(ls, lkb);
5812 goto out;
5813 }
5814
5815 /* add this new lkb to the per-process list of locks */
5816 spin_lock(&ua->proc->locks_spin);
5817 hold_lkb(lkb);
5818 list_add_tail(&lkb->lkb_ownqueue, &ua->proc->locks);
5819 spin_unlock(&ua->proc->locks_spin);
5820 out:
5821 dlm_unlock_recovery(ls);
5822 return error;
5823 }
5824
5825 int dlm_user_convert(struct dlm_ls *ls, struct dlm_user_args *ua_tmp,
5826 int mode, uint32_t flags, uint32_t lkid, char *lvb_in,
5827 unsigned long timeout_cs)
5828 {
5829 struct dlm_lkb *lkb;
5830 struct dlm_args args;
5831 struct dlm_user_args *ua;
5832 int error;
5833
5834 dlm_lock_recovery(ls);
5835
5836 error = find_lkb(ls, lkid, &lkb);
5837 if (error)
5838 goto out;
5839
5840 /* user can change the params on its lock when it converts it, or
5841 add an lvb that didn't exist before */
5842
5843 ua = lkb->lkb_ua;
5844
5845 if (flags & DLM_LKF_VALBLK && !ua->lksb.sb_lvbptr) {
5846 ua->lksb.sb_lvbptr = kzalloc(DLM_USER_LVB_LEN, GFP_NOFS);
5847 if (!ua->lksb.sb_lvbptr) {
5848 error = -ENOMEM;
5849 goto out_put;
5850 }
5851 }
5852 if (lvb_in && ua->lksb.sb_lvbptr)
5853 memcpy(ua->lksb.sb_lvbptr, lvb_in, DLM_USER_LVB_LEN);
5854
5855 ua->xid = ua_tmp->xid;
5856 ua->castparam = ua_tmp->castparam;
5857 ua->castaddr = ua_tmp->castaddr;
5858 ua->bastparam = ua_tmp->bastparam;
5859 ua->bastaddr = ua_tmp->bastaddr;
5860 ua->user_lksb = ua_tmp->user_lksb;
5861
5862 error = set_lock_args(mode, &ua->lksb, flags, 0, timeout_cs,
5863 fake_astfn, ua, fake_bastfn, &args);
5864 if (error)
5865 goto out_put;
5866
5867 error = convert_lock(ls, lkb, &args);
5868
5869 if (error == -EINPROGRESS || error == -EAGAIN || error == -EDEADLK)
5870 error = 0;
5871 out_put:
5872 dlm_put_lkb(lkb);
5873 out:
5874 dlm_unlock_recovery(ls);
5875 kfree(ua_tmp);
5876 return error;
5877 }
5878
5879 int dlm_user_unlock(struct dlm_ls *ls, struct dlm_user_args *ua_tmp,
5880 uint32_t flags, uint32_t lkid, char *lvb_in)
5881 {
5882 struct dlm_lkb *lkb;
5883 struct dlm_args args;
5884 struct dlm_user_args *ua;
5885 int error;
5886
5887 dlm_lock_recovery(ls);
5888
5889 error = find_lkb(ls, lkid, &lkb);
5890 if (error)
5891 goto out;
5892
5893 ua = lkb->lkb_ua;
5894
5895 if (lvb_in && ua->lksb.sb_lvbptr)
5896 memcpy(ua->lksb.sb_lvbptr, lvb_in, DLM_USER_LVB_LEN);
5897 if (ua_tmp->castparam)
5898 ua->castparam = ua_tmp->castparam;
5899 ua->user_lksb = ua_tmp->user_lksb;
5900
5901 error = set_unlock_args(flags, ua, &args);
5902 if (error)
5903 goto out_put;
5904
5905 error = unlock_lock(ls, lkb, &args);
5906
5907 if (error == -DLM_EUNLOCK)
5908 error = 0;
5909 /* from validate_unlock_args() */
5910 if (error == -EBUSY && (flags & DLM_LKF_FORCEUNLOCK))
5911 error = 0;
5912 if (error)
5913 goto out_put;
5914
5915 spin_lock(&ua->proc->locks_spin);
5916 /* dlm_user_add_cb() may have already taken lkb off the proc list */
5917 if (!list_empty(&lkb->lkb_ownqueue))
5918 list_move(&lkb->lkb_ownqueue, &ua->proc->unlocking);
5919 spin_unlock(&ua->proc->locks_spin);
5920 out_put:
5921 dlm_put_lkb(lkb);
5922 out:
5923 dlm_unlock_recovery(ls);
5924 kfree(ua_tmp);
5925 return error;
5926 }
5927
5928 int dlm_user_cancel(struct dlm_ls *ls, struct dlm_user_args *ua_tmp,
5929 uint32_t flags, uint32_t lkid)
5930 {
5931 struct dlm_lkb *lkb;
5932 struct dlm_args args;
5933 struct dlm_user_args *ua;
5934 int error;
5935
5936 dlm_lock_recovery(ls);
5937
5938 error = find_lkb(ls, lkid, &lkb);
5939 if (error)
5940 goto out;
5941
5942 ua = lkb->lkb_ua;
5943 if (ua_tmp->castparam)
5944 ua->castparam = ua_tmp->castparam;
5945 ua->user_lksb = ua_tmp->user_lksb;
5946
5947 error = set_unlock_args(flags, ua, &args);
5948 if (error)
5949 goto out_put;
5950
5951 error = cancel_lock(ls, lkb, &args);
5952
5953 if (error == -DLM_ECANCEL)
5954 error = 0;
5955 /* from validate_unlock_args() */
5956 if (error == -EBUSY)
5957 error = 0;
5958 out_put:
5959 dlm_put_lkb(lkb);
5960 out:
5961 dlm_unlock_recovery(ls);
5962 kfree(ua_tmp);
5963 return error;
5964 }
5965
5966 int dlm_user_deadlock(struct dlm_ls *ls, uint32_t flags, uint32_t lkid)
5967 {
5968 struct dlm_lkb *lkb;
5969 struct dlm_args args;
5970 struct dlm_user_args *ua;
5971 struct dlm_rsb *r;
5972 int error;
5973
5974 dlm_lock_recovery(ls);
5975
5976 error = find_lkb(ls, lkid, &lkb);
5977 if (error)
5978 goto out;
5979
5980 ua = lkb->lkb_ua;
5981
5982 error = set_unlock_args(flags, ua, &args);
5983 if (error)
5984 goto out_put;
5985
5986 /* same as cancel_lock(), but set DEADLOCK_CANCEL after lock_rsb */
5987
5988 r = lkb->lkb_resource;
5989 hold_rsb(r);
5990 lock_rsb(r);
5991
5992 error = validate_unlock_args(lkb, &args);
5993 if (error)
5994 goto out_r;
5995 lkb->lkb_flags |= DLM_IFL_DEADLOCK_CANCEL;
5996
5997 error = _cancel_lock(r, lkb);
5998 out_r:
5999 unlock_rsb(r);
6000 put_rsb(r);
6001
6002 if (error == -DLM_ECANCEL)
6003 error = 0;
6004 /* from validate_unlock_args() */
6005 if (error == -EBUSY)
6006 error = 0;
6007 out_put:
6008 dlm_put_lkb(lkb);
6009 out:
6010 dlm_unlock_recovery(ls);
6011 return error;
6012 }
6013
6014 /* lkb's that are removed from the waiters list by revert are just left on the
6015 orphans list with the granted orphan locks, to be freed by purge */
6016
6017 static int orphan_proc_lock(struct dlm_ls *ls, struct dlm_lkb *lkb)
6018 {
6019 struct dlm_args args;
6020 int error;
6021
6022 hold_lkb(lkb);
6023 mutex_lock(&ls->ls_orphans_mutex);
6024 list_add_tail(&lkb->lkb_ownqueue, &ls->ls_orphans);
6025 mutex_unlock(&ls->ls_orphans_mutex);
6026
6027 set_unlock_args(0, lkb->lkb_ua, &args);
6028
6029 error = cancel_lock(ls, lkb, &args);
6030 if (error == -DLM_ECANCEL)
6031 error = 0;
6032 return error;
6033 }
6034
6035 /* The FORCEUNLOCK flag allows the unlock to go ahead even if the lkb isn't
6036 granted. Regardless of what rsb queue the lock is on, it's removed and
6037 freed. The IVVALBLK flag causes the lvb on the resource to be invalidated
6038 if our lock is PW/EX (it's ignored if our granted mode is smaller.) */
6039
6040 static int unlock_proc_lock(struct dlm_ls *ls, struct dlm_lkb *lkb)
6041 {
6042 struct dlm_args args;
6043 int error;
6044
6045 set_unlock_args(DLM_LKF_FORCEUNLOCK | DLM_LKF_IVVALBLK,
6046 lkb->lkb_ua, &args);
6047
6048 error = unlock_lock(ls, lkb, &args);
6049 if (error == -DLM_EUNLOCK)
6050 error = 0;
6051 return error;
6052 }
6053
6054 /* We have to release clear_proc_locks mutex before calling unlock_proc_lock()
6055 (which does lock_rsb) due to deadlock with receiving a message that does
6056 lock_rsb followed by dlm_user_add_cb() */
6057
6058 static struct dlm_lkb *del_proc_lock(struct dlm_ls *ls,
6059 struct dlm_user_proc *proc)
6060 {
6061 struct dlm_lkb *lkb = NULL;
6062
6063 mutex_lock(&ls->ls_clear_proc_locks);
6064 if (list_empty(&proc->locks))
6065 goto out;
6066
6067 lkb = list_entry(proc->locks.next, struct dlm_lkb, lkb_ownqueue);
6068 list_del_init(&lkb->lkb_ownqueue);
6069
6070 if (lkb->lkb_exflags & DLM_LKF_PERSISTENT)
6071 lkb->lkb_flags |= DLM_IFL_ORPHAN;
6072 else
6073 lkb->lkb_flags |= DLM_IFL_DEAD;
6074 out:
6075 mutex_unlock(&ls->ls_clear_proc_locks);
6076 return lkb;
6077 }
6078
6079 /* The ls_clear_proc_locks mutex protects against dlm_user_add_cb() which
6080 1) references lkb->ua which we free here and 2) adds lkbs to proc->asts,
6081 which we clear here. */
6082
6083 /* proc CLOSING flag is set so no more device_reads should look at proc->asts
6084 list, and no more device_writes should add lkb's to proc->locks list; so we
6085 shouldn't need to take asts_spin or locks_spin here. this assumes that
6086 device reads/writes/closes are serialized -- FIXME: we may need to serialize
6087 them ourself. */
6088
6089 void dlm_clear_proc_locks(struct dlm_ls *ls, struct dlm_user_proc *proc)
6090 {
6091 struct dlm_lkb *lkb, *safe;
6092
6093 dlm_lock_recovery(ls);
6094
6095 while (1) {
6096 lkb = del_proc_lock(ls, proc);
6097 if (!lkb)
6098 break;
6099 del_timeout(lkb);
6100 if (lkb->lkb_exflags & DLM_LKF_PERSISTENT)
6101 orphan_proc_lock(ls, lkb);
6102 else
6103 unlock_proc_lock(ls, lkb);
6104
6105 /* this removes the reference for the proc->locks list
6106 added by dlm_user_request, it may result in the lkb
6107 being freed */
6108
6109 dlm_put_lkb(lkb);
6110 }
6111
6112 mutex_lock(&ls->ls_clear_proc_locks);
6113
6114 /* in-progress unlocks */
6115 list_for_each_entry_safe(lkb, safe, &proc->unlocking, lkb_ownqueue) {
6116 list_del_init(&lkb->lkb_ownqueue);
6117 lkb->lkb_flags |= DLM_IFL_DEAD;
6118 dlm_put_lkb(lkb);
6119 }
6120
6121 list_for_each_entry_safe(lkb, safe, &proc->asts, lkb_cb_list) {
6122 memset(&lkb->lkb_callbacks, 0,
6123 sizeof(struct dlm_callback) * DLM_CALLBACKS_SIZE);
6124 list_del_init(&lkb->lkb_cb_list);
6125 dlm_put_lkb(lkb);
6126 }
6127
6128 mutex_unlock(&ls->ls_clear_proc_locks);
6129 dlm_unlock_recovery(ls);
6130 }
6131
6132 static void purge_proc_locks(struct dlm_ls *ls, struct dlm_user_proc *proc)
6133 {
6134 struct dlm_lkb *lkb, *safe;
6135
6136 while (1) {
6137 lkb = NULL;
6138 spin_lock(&proc->locks_spin);
6139 if (!list_empty(&proc->locks)) {
6140 lkb = list_entry(proc->locks.next, struct dlm_lkb,
6141 lkb_ownqueue);
6142 list_del_init(&lkb->lkb_ownqueue);
6143 }
6144 spin_unlock(&proc->locks_spin);
6145
6146 if (!lkb)
6147 break;
6148
6149 lkb->lkb_flags |= DLM_IFL_DEAD;
6150 unlock_proc_lock(ls, lkb);
6151 dlm_put_lkb(lkb); /* ref from proc->locks list */
6152 }
6153
6154 spin_lock(&proc->locks_spin);
6155 list_for_each_entry_safe(lkb, safe, &proc->unlocking, lkb_ownqueue) {
6156 list_del_init(&lkb->lkb_ownqueue);
6157 lkb->lkb_flags |= DLM_IFL_DEAD;
6158 dlm_put_lkb(lkb);
6159 }
6160 spin_unlock(&proc->locks_spin);
6161
6162 spin_lock(&proc->asts_spin);
6163 list_for_each_entry_safe(lkb, safe, &proc->asts, lkb_cb_list) {
6164 memset(&lkb->lkb_callbacks, 0,
6165 sizeof(struct dlm_callback) * DLM_CALLBACKS_SIZE);
6166 list_del_init(&lkb->lkb_cb_list);
6167 dlm_put_lkb(lkb);
6168 }
6169 spin_unlock(&proc->asts_spin);
6170 }
6171
6172 /* pid of 0 means purge all orphans */
6173
6174 static void do_purge(struct dlm_ls *ls, int nodeid, int pid)
6175 {
6176 struct dlm_lkb *lkb, *safe;
6177
6178 mutex_lock(&ls->ls_orphans_mutex);
6179 list_for_each_entry_safe(lkb, safe, &ls->ls_orphans, lkb_ownqueue) {
6180 if (pid && lkb->lkb_ownpid != pid)
6181 continue;
6182 unlock_proc_lock(ls, lkb);
6183 list_del_init(&lkb->lkb_ownqueue);
6184 dlm_put_lkb(lkb);
6185 }
6186 mutex_unlock(&ls->ls_orphans_mutex);
6187 }
6188
6189 static int send_purge(struct dlm_ls *ls, int nodeid, int pid)
6190 {
6191 struct dlm_message *ms;
6192 struct dlm_mhandle *mh;
6193 int error;
6194
6195 error = _create_message(ls, sizeof(struct dlm_message), nodeid,
6196 DLM_MSG_PURGE, &ms, &mh);
6197 if (error)
6198 return error;
6199 ms->m_nodeid = nodeid;
6200 ms->m_pid = pid;
6201
6202 return send_message(mh, ms);
6203 }
6204
6205 int dlm_user_purge(struct dlm_ls *ls, struct dlm_user_proc *proc,
6206 int nodeid, int pid)
6207 {
6208 int error = 0;
6209
6210 if (nodeid != dlm_our_nodeid()) {
6211 error = send_purge(ls, nodeid, pid);
6212 } else {
6213 dlm_lock_recovery(ls);
6214 if (pid == current->pid)
6215 purge_proc_locks(ls, proc);
6216 else
6217 do_purge(ls, nodeid, pid);
6218 dlm_unlock_recovery(ls);
6219 }
6220 return error;
6221 }
6222