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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
78static int send_request(struct dlm_rsb *r, struct dlm_lkb *lkb);
79static int send_convert(struct dlm_rsb *r, struct dlm_lkb *lkb);
80static int send_unlock(struct dlm_rsb *r, struct dlm_lkb *lkb);
81static int send_cancel(struct dlm_rsb *r, struct dlm_lkb *lkb);
82static int send_grant(struct dlm_rsb *r, struct dlm_lkb *lkb);
83static int send_bast(struct dlm_rsb *r, struct dlm_lkb *lkb, int mode);
84static int send_lookup(struct dlm_rsb *r, struct dlm_lkb *lkb);
85static int send_remove(struct dlm_rsb *r);
86static int _request_lock(struct dlm_rsb *r, struct dlm_lkb *lkb);
87static int _cancel_lock(struct dlm_rsb *r, struct dlm_lkb *lkb);
88static void __receive_convert_reply(struct dlm_rsb *r, struct dlm_lkb *lkb,
89 struct dlm_message *ms);
90static int receive_extralen(struct dlm_message *ms);
91static void do_purge(struct dlm_ls *ls, int nodeid, int pid);
92static void del_timeout(struct dlm_lkb *lkb);
93static 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
103static 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
124const 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
139int 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
150static 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
162void 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
172static 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
181void 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
205static inline void dlm_lock_recovery(struct dlm_ls *ls)
206{
207 down_read(&ls->ls_in_recovery);
208}
209
210void dlm_unlock_recovery(struct dlm_ls *ls)
211{
212 up_read(&ls->ls_in_recovery);
213}
214
215int dlm_lock_recovery_try(struct dlm_ls *ls)
216{
217 return down_read_trylock(&ls->ls_in_recovery);
218}
219
220static inline int can_be_queued(struct dlm_lkb *lkb)
221{
222 return !(lkb->lkb_exflags & DLM_LKF_NOQUEUE);
223}
224
225static inline int force_blocking_asts(struct dlm_lkb *lkb)
226{
227 return (lkb->lkb_exflags & DLM_LKF_NOQUEUEBAST);
228}
229
230static inline int is_demoted(struct dlm_lkb *lkb)
231{
232 return (lkb->lkb_sbflags & DLM_SBF_DEMOTED);
233}
234
235static inline int is_altmode(struct dlm_lkb *lkb)
236{
237 return (lkb->lkb_sbflags & DLM_SBF_ALTMODE);
238}
239
240static inline int is_granted(struct dlm_lkb *lkb)
241{
242 return (lkb->lkb_status == DLM_LKSTS_GRANTED);
243}
244
245static 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
251static inline int is_process_copy(struct dlm_lkb *lkb)
252{
253 return (lkb->lkb_nodeid && !(lkb->lkb_flags & DLM_IFL_MSTCPY));
254}
255
256static inline int is_master_copy(struct dlm_lkb *lkb)
257{
258 return (lkb->lkb_flags & DLM_IFL_MSTCPY) ? 1 : 0;
259}
260
261static 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
269static inline int down_conversion(struct dlm_lkb *lkb)
270{
271 return (!middle_conversion(lkb) && lkb->lkb_rqmode < lkb->lkb_grmode);
272}
273
274static inline int is_overlap_unlock(struct dlm_lkb *lkb)
275{
276 return lkb->lkb_flags & DLM_IFL_OVERLAP_UNLOCK;
277}
278
279static inline int is_overlap_cancel(struct dlm_lkb *lkb)
280{
281 return lkb->lkb_flags & DLM_IFL_OVERLAP_CANCEL;
282}
283
284static 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
290static 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
314static 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
320static 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
336static inline void hold_rsb(struct dlm_rsb *r)
337{
338 kref_get(&r->res_ref);
339}
340
341void 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
349static 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
359void dlm_put_rsb(struct dlm_rsb *r)
360{
361 put_rsb(r);
362}
363
364static 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
400static 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
438static 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
447int 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
472static 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
545static 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 r = NULL;
691 error = -ENOTBLK;
692 goto out_unlock;
693 }
694
695 if (from_other) {
696 log_debug(ls, "find_rsb new from_other %d dir %d %s",
697 from_nodeid, dir_nodeid, r->res_name);
698 }
699
700 if (dir_nodeid == our_nodeid) {
701 /* When we are the dir nodeid, we can set the master
702 node immediately */
703 r->res_master_nodeid = our_nodeid;
704 r->res_nodeid = 0;
705 } else {
706 /* set_master will send_lookup to dir_nodeid */
707 r->res_master_nodeid = 0;
708 r->res_nodeid = -1;
709 }
710
711 out_add:
712 error = rsb_insert(r, &ls->ls_rsbtbl[b].keep);
713 out_unlock:
714 spin_unlock(&ls->ls_rsbtbl[b].lock);
715 out:
716 *r_ret = r;
717 return error;
718}
719
720/* During recovery, other nodes can send us new MSTCPY locks (from
721 dlm_recover_locks) before we've made ourself master (in
722 dlm_recover_masters). */
723
724static int find_rsb_nodir(struct dlm_ls *ls, char *name, int len,
725 uint32_t hash, uint32_t b,
726 int dir_nodeid, int from_nodeid,
727 unsigned int flags, struct dlm_rsb **r_ret)
728{
729 struct dlm_rsb *r = NULL;
730 int our_nodeid = dlm_our_nodeid();
731 int recover = (flags & R_RECEIVE_RECOVER);
732 int error;
733
734 retry:
735 error = pre_rsb_struct(ls);
736 if (error < 0)
737 goto out;
738
739 spin_lock(&ls->ls_rsbtbl[b].lock);
740
741 error = dlm_search_rsb_tree(&ls->ls_rsbtbl[b].keep, name, len, &r);
742 if (error)
743 goto do_toss;
744
745 /*
746 * rsb is active, so we can't check master_nodeid without lock_rsb.
747 */
748
749 kref_get(&r->res_ref);
750 goto out_unlock;
751
752
753 do_toss:
754 error = dlm_search_rsb_tree(&ls->ls_rsbtbl[b].toss, name, len, &r);
755 if (error)
756 goto do_new;
757
758 /*
759 * rsb found inactive. No other thread is using this rsb because
760 * it's on the toss list, so we can look at or update
761 * res_master_nodeid without lock_rsb.
762 */
763
764 if (!recover && (r->res_master_nodeid != our_nodeid) && from_nodeid) {
765 /* our rsb is not master, and another node has sent us a
766 request; this should never happen */
767 log_error(ls, "find_rsb toss from_nodeid %d master %d dir %d",
768 from_nodeid, r->res_master_nodeid, dir_nodeid);
769 dlm_print_rsb(r);
770 error = -ENOTBLK;
771 goto out_unlock;
772 }
773
774 if (!recover && (r->res_master_nodeid != our_nodeid) &&
775 (dir_nodeid == our_nodeid)) {
776 /* our rsb is not master, and we are dir; may as well fix it;
777 this should never happen */
778 log_error(ls, "find_rsb toss our %d master %d dir %d",
779 our_nodeid, r->res_master_nodeid, dir_nodeid);
780 dlm_print_rsb(r);
781 r->res_master_nodeid = our_nodeid;
782 r->res_nodeid = 0;
783 }
784
785 rb_erase(&r->res_hashnode, &ls->ls_rsbtbl[b].toss);
786 error = rsb_insert(r, &ls->ls_rsbtbl[b].keep);
787 goto out_unlock;
788
789
790 do_new:
791 /*
792 * rsb not found
793 */
794
795 error = get_rsb_struct(ls, name, len, &r);
796 if (error == -EAGAIN) {
797 spin_unlock(&ls->ls_rsbtbl[b].lock);
798 goto retry;
799 }
800 if (error)
801 goto out_unlock;
802
803 r->res_hash = hash;
804 r->res_bucket = b;
805 r->res_dir_nodeid = dir_nodeid;
806 r->res_master_nodeid = dir_nodeid;
807 r->res_nodeid = (dir_nodeid == our_nodeid) ? 0 : dir_nodeid;
808 kref_init(&r->res_ref);
809
810 error = rsb_insert(r, &ls->ls_rsbtbl[b].keep);
811 out_unlock:
812 spin_unlock(&ls->ls_rsbtbl[b].lock);
813 out:
814 *r_ret = r;
815 return error;
816}
817
818static int find_rsb(struct dlm_ls *ls, char *name, int len, int from_nodeid,
819 unsigned int flags, struct dlm_rsb **r_ret)
820{
821 uint32_t hash, b;
822 int dir_nodeid;
823
824 if (len > DLM_RESNAME_MAXLEN)
825 return -EINVAL;
826
827 hash = jhash(name, len, 0);
828 b = hash & (ls->ls_rsbtbl_size - 1);
829
830 dir_nodeid = dlm_hash2nodeid(ls, hash);
831
832 if (dlm_no_directory(ls))
833 return find_rsb_nodir(ls, name, len, hash, b, dir_nodeid,
834 from_nodeid, flags, r_ret);
835 else
836 return find_rsb_dir(ls, name, len, hash, b, dir_nodeid,
837 from_nodeid, flags, r_ret);
838}
839
840/* we have received a request and found that res_master_nodeid != our_nodeid,
841 so we need to return an error or make ourself the master */
842
843static int validate_master_nodeid(struct dlm_ls *ls, struct dlm_rsb *r,
844 int from_nodeid)
845{
846 if (dlm_no_directory(ls)) {
847 log_error(ls, "find_rsb keep from_nodeid %d master %d dir %d",
848 from_nodeid, r->res_master_nodeid,
849 r->res_dir_nodeid);
850 dlm_print_rsb(r);
851 return -ENOTBLK;
852 }
853
854 if (from_nodeid != r->res_dir_nodeid) {
855 /* our rsb is not master, and another node (not the dir node)
856 has sent us a request. this is much more common when our
857 master_nodeid is zero, so limit debug to non-zero. */
858
859 if (r->res_master_nodeid) {
860 log_debug(ls, "validate master from_other %d master %d "
861 "dir %d first %x %s", from_nodeid,
862 r->res_master_nodeid, r->res_dir_nodeid,
863 r->res_first_lkid, r->res_name);
864 }
865 return -ENOTBLK;
866 } else {
867 /* our rsb is not master, but the dir nodeid has sent us a
868 request; this could happen with master 0 / res_nodeid -1 */
869
870 if (r->res_master_nodeid) {
871 log_error(ls, "validate master from_dir %d master %d "
872 "first %x %s",
873 from_nodeid, r->res_master_nodeid,
874 r->res_first_lkid, r->res_name);
875 }
876
877 r->res_master_nodeid = dlm_our_nodeid();
878 r->res_nodeid = 0;
879 return 0;
880 }
881}
882
883/*
884 * We're the dir node for this res and another node wants to know the
885 * master nodeid. During normal operation (non recovery) this is only
886 * called from receive_lookup(); master lookups when the local node is
887 * the dir node are done by find_rsb().
888 *
889 * normal operation, we are the dir node for a resource
890 * . _request_lock
891 * . set_master
892 * . send_lookup
893 * . receive_lookup
894 * . dlm_master_lookup flags 0
895 *
896 * recover directory, we are rebuilding dir for all resources
897 * . dlm_recover_directory
898 * . dlm_rcom_names
899 * remote node sends back the rsb names it is master of and we are dir of
900 * . dlm_master_lookup RECOVER_DIR (fix_master 0, from_master 1)
901 * we either create new rsb setting remote node as master, or find existing
902 * rsb and set master to be the remote node.
903 *
904 * recover masters, we are finding the new master for resources
905 * . dlm_recover_masters
906 * . recover_master
907 * . dlm_send_rcom_lookup
908 * . receive_rcom_lookup
909 * . dlm_master_lookup RECOVER_MASTER (fix_master 1, from_master 0)
910 */
911
912int dlm_master_lookup(struct dlm_ls *ls, int from_nodeid, char *name, int len,
913 unsigned int flags, int *r_nodeid, int *result)
914{
915 struct dlm_rsb *r = NULL;
916 uint32_t hash, b;
917 int from_master = (flags & DLM_LU_RECOVER_DIR);
918 int fix_master = (flags & DLM_LU_RECOVER_MASTER);
919 int our_nodeid = dlm_our_nodeid();
920 int dir_nodeid, error, toss_list = 0;
921
922 if (len > DLM_RESNAME_MAXLEN)
923 return -EINVAL;
924
925 if (from_nodeid == our_nodeid) {
926 log_error(ls, "dlm_master_lookup from our_nodeid %d flags %x",
927 our_nodeid, flags);
928 return -EINVAL;
929 }
930
931 hash = jhash(name, len, 0);
932 b = hash & (ls->ls_rsbtbl_size - 1);
933
934 dir_nodeid = dlm_hash2nodeid(ls, hash);
935 if (dir_nodeid != our_nodeid) {
936 log_error(ls, "dlm_master_lookup from %d dir %d our %d h %x %d",
937 from_nodeid, dir_nodeid, our_nodeid, hash,
938 ls->ls_num_nodes);
939 *r_nodeid = -1;
940 return -EINVAL;
941 }
942
943 retry:
944 error = pre_rsb_struct(ls);
945 if (error < 0)
946 return error;
947
948 spin_lock(&ls->ls_rsbtbl[b].lock);
949 error = dlm_search_rsb_tree(&ls->ls_rsbtbl[b].keep, name, len, &r);
950 if (!error) {
951 /* because the rsb is active, we need to lock_rsb before
952 checking/changing re_master_nodeid */
953
954 hold_rsb(r);
955 spin_unlock(&ls->ls_rsbtbl[b].lock);
956 lock_rsb(r);
957 goto found;
958 }
959
960 error = dlm_search_rsb_tree(&ls->ls_rsbtbl[b].toss, name, len, &r);
961 if (error)
962 goto not_found;
963
964 /* because the rsb is inactive (on toss list), it's not refcounted
965 and lock_rsb is not used, but is protected by the rsbtbl lock */
966
967 toss_list = 1;
968 found:
969 if (r->res_dir_nodeid != our_nodeid) {
970 /* should not happen, but may as well fix it and carry on */
971 log_error(ls, "dlm_master_lookup res_dir %d our %d %s",
972 r->res_dir_nodeid, our_nodeid, r->res_name);
973 r->res_dir_nodeid = our_nodeid;
974 }
975
976 if (fix_master && dlm_is_removed(ls, r->res_master_nodeid)) {
977 /* Recovery uses this function to set a new master when
978 the previous master failed. Setting NEW_MASTER will
979 force dlm_recover_masters to call recover_master on this
980 rsb even though the res_nodeid is no longer removed. */
981
982 r->res_master_nodeid = from_nodeid;
983 r->res_nodeid = from_nodeid;
984 rsb_set_flag(r, RSB_NEW_MASTER);
985
986 if (toss_list) {
987 /* I don't think we should ever find it on toss list. */
988 log_error(ls, "dlm_master_lookup fix_master on toss");
989 dlm_dump_rsb(r);
990 }
991 }
992
993 if (from_master && (r->res_master_nodeid != from_nodeid)) {
994 /* this will happen if from_nodeid became master during
995 a previous recovery cycle, and we aborted the previous
996 cycle before recovering this master value */
997
998 log_limit(ls, "dlm_master_lookup from_master %d "
999 "master_nodeid %d res_nodeid %d first %x %s",
1000 from_nodeid, r->res_master_nodeid, r->res_nodeid,
1001 r->res_first_lkid, r->res_name);
1002
1003 if (r->res_master_nodeid == our_nodeid) {
1004 log_error(ls, "from_master %d our_master", from_nodeid);
1005 dlm_dump_rsb(r);
1006 dlm_send_rcom_lookup_dump(r, from_nodeid);
1007 goto out_found;
1008 }
1009
1010 r->res_master_nodeid = from_nodeid;
1011 r->res_nodeid = from_nodeid;
1012 rsb_set_flag(r, RSB_NEW_MASTER);
1013 }
1014
1015 if (!r->res_master_nodeid) {
1016 /* this will happen if recovery happens while we're looking
1017 up the master for this rsb */
1018
1019 log_debug(ls, "dlm_master_lookup master 0 to %d first %x %s",
1020 from_nodeid, r->res_first_lkid, r->res_name);
1021 r->res_master_nodeid = from_nodeid;
1022 r->res_nodeid = from_nodeid;
1023 }
1024
1025 if (!from_master && !fix_master &&
1026 (r->res_master_nodeid == from_nodeid)) {
1027 /* this can happen when the master sends remove, the dir node
1028 finds the rsb on the keep list and ignores the remove,
1029 and the former master sends a lookup */
1030
1031 log_limit(ls, "dlm_master_lookup from master %d flags %x "
1032 "first %x %s", from_nodeid, flags,
1033 r->res_first_lkid, r->res_name);
1034 }
1035
1036 out_found:
1037 *r_nodeid = r->res_master_nodeid;
1038 if (result)
1039 *result = DLM_LU_MATCH;
1040
1041 if (toss_list) {
1042 r->res_toss_time = jiffies;
1043 /* the rsb was inactive (on toss list) */
1044 spin_unlock(&ls->ls_rsbtbl[b].lock);
1045 } else {
1046 /* the rsb was active */
1047 unlock_rsb(r);
1048 put_rsb(r);
1049 }
1050 return 0;
1051
1052 not_found:
1053 error = get_rsb_struct(ls, name, len, &r);
1054 if (error == -EAGAIN) {
1055 spin_unlock(&ls->ls_rsbtbl[b].lock);
1056 goto retry;
1057 }
1058 if (error)
1059 goto out_unlock;
1060
1061 r->res_hash = hash;
1062 r->res_bucket = b;
1063 r->res_dir_nodeid = our_nodeid;
1064 r->res_master_nodeid = from_nodeid;
1065 r->res_nodeid = from_nodeid;
1066 kref_init(&r->res_ref);
1067 r->res_toss_time = jiffies;
1068
1069 error = rsb_insert(r, &ls->ls_rsbtbl[b].toss);
1070 if (error) {
1071 /* should never happen */
1072 dlm_free_rsb(r);
1073 spin_unlock(&ls->ls_rsbtbl[b].lock);
1074 goto retry;
1075 }
1076
1077 if (result)
1078 *result = DLM_LU_ADD;
1079 *r_nodeid = from_nodeid;
1080 error = 0;
1081 out_unlock:
1082 spin_unlock(&ls->ls_rsbtbl[b].lock);
1083 return error;
1084}
1085
1086static void dlm_dump_rsb_hash(struct dlm_ls *ls, uint32_t hash)
1087{
1088 struct rb_node *n;
1089 struct dlm_rsb *r;
1090 int i;
1091
1092 for (i = 0; i < ls->ls_rsbtbl_size; i++) {
1093 spin_lock(&ls->ls_rsbtbl[i].lock);
1094 for (n = rb_first(&ls->ls_rsbtbl[i].keep); n; n = rb_next(n)) {
1095 r = rb_entry(n, struct dlm_rsb, res_hashnode);
1096 if (r->res_hash == hash)
1097 dlm_dump_rsb(r);
1098 }
1099 spin_unlock(&ls->ls_rsbtbl[i].lock);
1100 }
1101}
1102
1103void dlm_dump_rsb_name(struct dlm_ls *ls, char *name, int len)
1104{
1105 struct dlm_rsb *r = NULL;
1106 uint32_t hash, b;
1107 int error;
1108
1109 hash = jhash(name, len, 0);
1110 b = hash & (ls->ls_rsbtbl_size - 1);
1111
1112 spin_lock(&ls->ls_rsbtbl[b].lock);
1113 error = dlm_search_rsb_tree(&ls->ls_rsbtbl[b].keep, name, len, &r);
1114 if (!error)
1115 goto out_dump;
1116
1117 error = dlm_search_rsb_tree(&ls->ls_rsbtbl[b].toss, name, len, &r);
1118 if (error)
1119 goto out;
1120 out_dump:
1121 dlm_dump_rsb(r);
1122 out:
1123 spin_unlock(&ls->ls_rsbtbl[b].lock);
1124}
1125
1126static void toss_rsb(struct kref *kref)
1127{
1128 struct dlm_rsb *r = container_of(kref, struct dlm_rsb, res_ref);
1129 struct dlm_ls *ls = r->res_ls;
1130
1131 DLM_ASSERT(list_empty(&r->res_root_list), dlm_print_rsb(r););
1132 kref_init(&r->res_ref);
1133 rb_erase(&r->res_hashnode, &ls->ls_rsbtbl[r->res_bucket].keep);
1134 rsb_insert(r, &ls->ls_rsbtbl[r->res_bucket].toss);
1135 r->res_toss_time = jiffies;
1136 ls->ls_rsbtbl[r->res_bucket].flags |= DLM_RTF_SHRINK;
1137 if (r->res_lvbptr) {
1138 dlm_free_lvb(r->res_lvbptr);
1139 r->res_lvbptr = NULL;
1140 }
1141}
1142
1143/* See comment for unhold_lkb */
1144
1145static void unhold_rsb(struct dlm_rsb *r)
1146{
1147 int rv;
1148 rv = kref_put(&r->res_ref, toss_rsb);
1149 DLM_ASSERT(!rv, dlm_dump_rsb(r););
1150}
1151
1152static void kill_rsb(struct kref *kref)
1153{
1154 struct dlm_rsb *r = container_of(kref, struct dlm_rsb, res_ref);
1155
1156 /* All work is done after the return from kref_put() so we
1157 can release the write_lock before the remove and free. */
1158
1159 DLM_ASSERT(list_empty(&r->res_lookup), dlm_dump_rsb(r););
1160 DLM_ASSERT(list_empty(&r->res_grantqueue), dlm_dump_rsb(r););
1161 DLM_ASSERT(list_empty(&r->res_convertqueue), dlm_dump_rsb(r););
1162 DLM_ASSERT(list_empty(&r->res_waitqueue), dlm_dump_rsb(r););
1163 DLM_ASSERT(list_empty(&r->res_root_list), dlm_dump_rsb(r););
1164 DLM_ASSERT(list_empty(&r->res_recover_list), dlm_dump_rsb(r););
1165}
1166
1167/* Attaching/detaching lkb's from rsb's is for rsb reference counting.
1168 The rsb must exist as long as any lkb's for it do. */
1169
1170static void attach_lkb(struct dlm_rsb *r, struct dlm_lkb *lkb)
1171{
1172 hold_rsb(r);
1173 lkb->lkb_resource = r;
1174}
1175
1176static void detach_lkb(struct dlm_lkb *lkb)
1177{
1178 if (lkb->lkb_resource) {
1179 put_rsb(lkb->lkb_resource);
1180 lkb->lkb_resource = NULL;
1181 }
1182}
1183
1184static int create_lkb(struct dlm_ls *ls, struct dlm_lkb **lkb_ret)
1185{
1186 struct dlm_lkb *lkb;
1187 int rv;
1188
1189 lkb = dlm_allocate_lkb(ls);
1190 if (!lkb)
1191 return -ENOMEM;
1192
1193 lkb->lkb_nodeid = -1;
1194 lkb->lkb_grmode = DLM_LOCK_IV;
1195 kref_init(&lkb->lkb_ref);
1196 INIT_LIST_HEAD(&lkb->lkb_ownqueue);
1197 INIT_LIST_HEAD(&lkb->lkb_rsb_lookup);
1198 INIT_LIST_HEAD(&lkb->lkb_time_list);
1199 INIT_LIST_HEAD(&lkb->lkb_cb_list);
1200 mutex_init(&lkb->lkb_cb_mutex);
1201 INIT_WORK(&lkb->lkb_cb_work, dlm_callback_work);
1202
1203 idr_preload(GFP_NOFS);
1204 spin_lock(&ls->ls_lkbidr_spin);
1205 rv = idr_alloc(&ls->ls_lkbidr, lkb, 1, 0, GFP_NOWAIT);
1206 if (rv >= 0)
1207 lkb->lkb_id = rv;
1208 spin_unlock(&ls->ls_lkbidr_spin);
1209 idr_preload_end();
1210
1211 if (rv < 0) {
1212 log_error(ls, "create_lkb idr error %d", rv);
1213 return rv;
1214 }
1215
1216 *lkb_ret = lkb;
1217 return 0;
1218}
1219
1220static int find_lkb(struct dlm_ls *ls, uint32_t lkid, struct dlm_lkb **lkb_ret)
1221{
1222 struct dlm_lkb *lkb;
1223
1224 spin_lock(&ls->ls_lkbidr_spin);
1225 lkb = idr_find(&ls->ls_lkbidr, lkid);
1226 if (lkb)
1227 kref_get(&lkb->lkb_ref);
1228 spin_unlock(&ls->ls_lkbidr_spin);
1229
1230 *lkb_ret = lkb;
1231 return lkb ? 0 : -ENOENT;
1232}
1233
1234static void kill_lkb(struct kref *kref)
1235{
1236 struct dlm_lkb *lkb = container_of(kref, struct dlm_lkb, lkb_ref);
1237
1238 /* All work is done after the return from kref_put() so we
1239 can release the write_lock before the detach_lkb */
1240
1241 DLM_ASSERT(!lkb->lkb_status, dlm_print_lkb(lkb););
1242}
1243
1244/* __put_lkb() is used when an lkb may not have an rsb attached to
1245 it so we need to provide the lockspace explicitly */
1246
1247static int __put_lkb(struct dlm_ls *ls, struct dlm_lkb *lkb)
1248{
1249 uint32_t lkid = lkb->lkb_id;
1250
1251 spin_lock(&ls->ls_lkbidr_spin);
1252 if (kref_put(&lkb->lkb_ref, kill_lkb)) {
1253 idr_remove(&ls->ls_lkbidr, lkid);
1254 spin_unlock(&ls->ls_lkbidr_spin);
1255
1256 detach_lkb(lkb);
1257
1258 /* for local/process lkbs, lvbptr points to caller's lksb */
1259 if (lkb->lkb_lvbptr && is_master_copy(lkb))
1260 dlm_free_lvb(lkb->lkb_lvbptr);
1261 dlm_free_lkb(lkb);
1262 return 1;
1263 } else {
1264 spin_unlock(&ls->ls_lkbidr_spin);
1265 return 0;
1266 }
1267}
1268
1269int dlm_put_lkb(struct dlm_lkb *lkb)
1270{
1271 struct dlm_ls *ls;
1272
1273 DLM_ASSERT(lkb->lkb_resource, dlm_print_lkb(lkb););
1274 DLM_ASSERT(lkb->lkb_resource->res_ls, dlm_print_lkb(lkb););
1275
1276 ls = lkb->lkb_resource->res_ls;
1277 return __put_lkb(ls, lkb);
1278}
1279
1280/* This is only called to add a reference when the code already holds
1281 a valid reference to the lkb, so there's no need for locking. */
1282
1283static inline void hold_lkb(struct dlm_lkb *lkb)
1284{
1285 kref_get(&lkb->lkb_ref);
1286}
1287
1288/* This is called when we need to remove a reference and are certain
1289 it's not the last ref. e.g. del_lkb is always called between a
1290 find_lkb/put_lkb and is always the inverse of a previous add_lkb.
1291 put_lkb would work fine, but would involve unnecessary locking */
1292
1293static inline void unhold_lkb(struct dlm_lkb *lkb)
1294{
1295 int rv;
1296 rv = kref_put(&lkb->lkb_ref, kill_lkb);
1297 DLM_ASSERT(!rv, dlm_print_lkb(lkb););
1298}
1299
1300static void lkb_add_ordered(struct list_head *new, struct list_head *head,
1301 int mode)
1302{
1303 struct dlm_lkb *lkb = NULL;
1304
1305 list_for_each_entry(lkb, head, lkb_statequeue)
1306 if (lkb->lkb_rqmode < mode)
1307 break;
1308
1309 __list_add(new, lkb->lkb_statequeue.prev, &lkb->lkb_statequeue);
1310}
1311
1312/* add/remove lkb to rsb's grant/convert/wait queue */
1313
1314static void add_lkb(struct dlm_rsb *r, struct dlm_lkb *lkb, int status)
1315{
1316 kref_get(&lkb->lkb_ref);
1317
1318 DLM_ASSERT(!lkb->lkb_status, dlm_print_lkb(lkb););
1319
1320 lkb->lkb_timestamp = ktime_get();
1321
1322 lkb->lkb_status = status;
1323
1324 switch (status) {
1325 case DLM_LKSTS_WAITING:
1326 if (lkb->lkb_exflags & DLM_LKF_HEADQUE)
1327 list_add(&lkb->lkb_statequeue, &r->res_waitqueue);
1328 else
1329 list_add_tail(&lkb->lkb_statequeue, &r->res_waitqueue);
1330 break;
1331 case DLM_LKSTS_GRANTED:
1332 /* convention says granted locks kept in order of grmode */
1333 lkb_add_ordered(&lkb->lkb_statequeue, &r->res_grantqueue,
1334 lkb->lkb_grmode);
1335 break;
1336 case DLM_LKSTS_CONVERT:
1337 if (lkb->lkb_exflags & DLM_LKF_HEADQUE)
1338 list_add(&lkb->lkb_statequeue, &r->res_convertqueue);
1339 else
1340 list_add_tail(&lkb->lkb_statequeue,
1341 &r->res_convertqueue);
1342 break;
1343 default:
1344 DLM_ASSERT(0, dlm_print_lkb(lkb); printk("sts=%d\n", status););
1345 }
1346}
1347
1348static void del_lkb(struct dlm_rsb *r, struct dlm_lkb *lkb)
1349{
1350 lkb->lkb_status = 0;
1351 list_del(&lkb->lkb_statequeue);
1352 unhold_lkb(lkb);
1353}
1354
1355static void move_lkb(struct dlm_rsb *r, struct dlm_lkb *lkb, int sts)
1356{
1357 hold_lkb(lkb);
1358 del_lkb(r, lkb);
1359 add_lkb(r, lkb, sts);
1360 unhold_lkb(lkb);
1361}
1362
1363static int msg_reply_type(int mstype)
1364{
1365 switch (mstype) {
1366 case DLM_MSG_REQUEST:
1367 return DLM_MSG_REQUEST_REPLY;
1368 case DLM_MSG_CONVERT:
1369 return DLM_MSG_CONVERT_REPLY;
1370 case DLM_MSG_UNLOCK:
1371 return DLM_MSG_UNLOCK_REPLY;
1372 case DLM_MSG_CANCEL:
1373 return DLM_MSG_CANCEL_REPLY;
1374 case DLM_MSG_LOOKUP:
1375 return DLM_MSG_LOOKUP_REPLY;
1376 }
1377 return -1;
1378}
1379
1380static int nodeid_warned(int nodeid, int num_nodes, int *warned)
1381{
1382 int i;
1383
1384 for (i = 0; i < num_nodes; i++) {
1385 if (!warned[i]) {
1386 warned[i] = nodeid;
1387 return 0;
1388 }
1389 if (warned[i] == nodeid)
1390 return 1;
1391 }
1392 return 0;
1393}
1394
1395void dlm_scan_waiters(struct dlm_ls *ls)
1396{
1397 struct dlm_lkb *lkb;
1398 ktime_t zero = ktime_set(0, 0);
1399 s64 us;
1400 s64 debug_maxus = 0;
1401 u32 debug_scanned = 0;
1402 u32 debug_expired = 0;
1403 int num_nodes = 0;
1404 int *warned = NULL;
1405
1406 if (!dlm_config.ci_waitwarn_us)
1407 return;
1408
1409 mutex_lock(&ls->ls_waiters_mutex);
1410
1411 list_for_each_entry(lkb, &ls->ls_waiters, lkb_wait_reply) {
1412 if (ktime_equal(lkb->lkb_wait_time, zero))
1413 continue;
1414
1415 debug_scanned++;
1416
1417 us = ktime_to_us(ktime_sub(ktime_get(), lkb->lkb_wait_time));
1418
1419 if (us < dlm_config.ci_waitwarn_us)
1420 continue;
1421
1422 lkb->lkb_wait_time = zero;
1423
1424 debug_expired++;
1425 if (us > debug_maxus)
1426 debug_maxus = us;
1427
1428 if (!num_nodes) {
1429 num_nodes = ls->ls_num_nodes;
1430 warned = kzalloc(num_nodes * sizeof(int), GFP_KERNEL);
1431 }
1432 if (!warned)
1433 continue;
1434 if (nodeid_warned(lkb->lkb_wait_nodeid, num_nodes, warned))
1435 continue;
1436
1437 log_error(ls, "waitwarn %x %lld %d us check connection to "
1438 "node %d", lkb->lkb_id, (long long)us,
1439 dlm_config.ci_waitwarn_us, lkb->lkb_wait_nodeid);
1440 }
1441 mutex_unlock(&ls->ls_waiters_mutex);
1442 kfree(warned);
1443
1444 if (debug_expired)
1445 log_debug(ls, "scan_waiters %u warn %u over %d us max %lld us",
1446 debug_scanned, debug_expired,
1447 dlm_config.ci_waitwarn_us, (long long)debug_maxus);
1448}
1449
1450/* add/remove lkb from global waiters list of lkb's waiting for
1451 a reply from a remote node */
1452
1453static int add_to_waiters(struct dlm_lkb *lkb, int mstype, int to_nodeid)
1454{
1455 struct dlm_ls *ls = lkb->lkb_resource->res_ls;
1456 int error = 0;
1457
1458 mutex_lock(&ls->ls_waiters_mutex);
1459
1460 if (is_overlap_unlock(lkb) ||
1461 (is_overlap_cancel(lkb) && (mstype == DLM_MSG_CANCEL))) {
1462 error = -EINVAL;
1463 goto out;
1464 }
1465
1466 if (lkb->lkb_wait_type || is_overlap_cancel(lkb)) {
1467 switch (mstype) {
1468 case DLM_MSG_UNLOCK:
1469 lkb->lkb_flags |= DLM_IFL_OVERLAP_UNLOCK;
1470 break;
1471 case DLM_MSG_CANCEL:
1472 lkb->lkb_flags |= DLM_IFL_OVERLAP_CANCEL;
1473 break;
1474 default:
1475 error = -EBUSY;
1476 goto out;
1477 }
1478 lkb->lkb_wait_count++;
1479 hold_lkb(lkb);
1480
1481 log_debug(ls, "addwait %x cur %d overlap %d count %d f %x",
1482 lkb->lkb_id, lkb->lkb_wait_type, mstype,
1483 lkb->lkb_wait_count, lkb->lkb_flags);
1484 goto out;
1485 }
1486
1487 DLM_ASSERT(!lkb->lkb_wait_count,
1488 dlm_print_lkb(lkb);
1489 printk("wait_count %d\n", lkb->lkb_wait_count););
1490
1491 lkb->lkb_wait_count++;
1492 lkb->lkb_wait_type = mstype;
1493 lkb->lkb_wait_time = ktime_get();
1494 lkb->lkb_wait_nodeid = to_nodeid; /* for debugging */
1495 hold_lkb(lkb);
1496 list_add(&lkb->lkb_wait_reply, &ls->ls_waiters);
1497 out:
1498 if (error)
1499 log_error(ls, "addwait error %x %d flags %x %d %d %s",
1500 lkb->lkb_id, error, lkb->lkb_flags, mstype,
1501 lkb->lkb_wait_type, lkb->lkb_resource->res_name);
1502 mutex_unlock(&ls->ls_waiters_mutex);
1503 return error;
1504}
1505
1506/* We clear the RESEND flag because we might be taking an lkb off the waiters
1507 list as part of process_requestqueue (e.g. a lookup that has an optimized
1508 request reply on the requestqueue) between dlm_recover_waiters_pre() which
1509 set RESEND and dlm_recover_waiters_post() */
1510
1511static int _remove_from_waiters(struct dlm_lkb *lkb, int mstype,
1512 struct dlm_message *ms)
1513{
1514 struct dlm_ls *ls = lkb->lkb_resource->res_ls;
1515 int overlap_done = 0;
1516
1517 if (is_overlap_unlock(lkb) && (mstype == DLM_MSG_UNLOCK_REPLY)) {
1518 log_debug(ls, "remwait %x unlock_reply overlap", lkb->lkb_id);
1519 lkb->lkb_flags &= ~DLM_IFL_OVERLAP_UNLOCK;
1520 overlap_done = 1;
1521 goto out_del;
1522 }
1523
1524 if (is_overlap_cancel(lkb) && (mstype == DLM_MSG_CANCEL_REPLY)) {
1525 log_debug(ls, "remwait %x cancel_reply overlap", lkb->lkb_id);
1526 lkb->lkb_flags &= ~DLM_IFL_OVERLAP_CANCEL;
1527 overlap_done = 1;
1528 goto out_del;
1529 }
1530
1531 /* Cancel state was preemptively cleared by a successful convert,
1532 see next comment, nothing to do. */
1533
1534 if ((mstype == DLM_MSG_CANCEL_REPLY) &&
1535 (lkb->lkb_wait_type != DLM_MSG_CANCEL)) {
1536 log_debug(ls, "remwait %x cancel_reply wait_type %d",
1537 lkb->lkb_id, lkb->lkb_wait_type);
1538 return -1;
1539 }
1540
1541 /* Remove for the convert reply, and premptively remove for the
1542 cancel reply. A convert has been granted while there's still
1543 an outstanding cancel on it (the cancel is moot and the result
1544 in the cancel reply should be 0). We preempt the cancel reply
1545 because the app gets the convert result and then can follow up
1546 with another op, like convert. This subsequent op would see the
1547 lingering state of the cancel and fail with -EBUSY. */
1548
1549 if ((mstype == DLM_MSG_CONVERT_REPLY) &&
1550 (lkb->lkb_wait_type == DLM_MSG_CONVERT) &&
1551 is_overlap_cancel(lkb) && ms && !ms->m_result) {
1552 log_debug(ls, "remwait %x convert_reply zap overlap_cancel",
1553 lkb->lkb_id);
1554 lkb->lkb_wait_type = 0;
1555 lkb->lkb_flags &= ~DLM_IFL_OVERLAP_CANCEL;
1556 lkb->lkb_wait_count--;
1557 goto out_del;
1558 }
1559
1560 /* N.B. type of reply may not always correspond to type of original
1561 msg due to lookup->request optimization, verify others? */
1562
1563 if (lkb->lkb_wait_type) {
1564 lkb->lkb_wait_type = 0;
1565 goto out_del;
1566 }
1567
1568 log_error(ls, "remwait error %x remote %d %x msg %d flags %x no wait",
1569 lkb->lkb_id, ms ? ms->m_header.h_nodeid : 0, lkb->lkb_remid,
1570 mstype, lkb->lkb_flags);
1571 return -1;
1572
1573 out_del:
1574 /* the force-unlock/cancel has completed and we haven't recvd a reply
1575 to the op that was in progress prior to the unlock/cancel; we
1576 give up on any reply to the earlier op. FIXME: not sure when/how
1577 this would happen */
1578
1579 if (overlap_done && lkb->lkb_wait_type) {
1580 log_error(ls, "remwait error %x reply %d wait_type %d overlap",
1581 lkb->lkb_id, mstype, lkb->lkb_wait_type);
1582 lkb->lkb_wait_count--;
1583 lkb->lkb_wait_type = 0;
1584 }
1585
1586 DLM_ASSERT(lkb->lkb_wait_count, dlm_print_lkb(lkb););
1587
1588 lkb->lkb_flags &= ~DLM_IFL_RESEND;
1589 lkb->lkb_wait_count--;
1590 if (!lkb->lkb_wait_count)
1591 list_del_init(&lkb->lkb_wait_reply);
1592 unhold_lkb(lkb);
1593 return 0;
1594}
1595
1596static int remove_from_waiters(struct dlm_lkb *lkb, int mstype)
1597{
1598 struct dlm_ls *ls = lkb->lkb_resource->res_ls;
1599 int error;
1600
1601 mutex_lock(&ls->ls_waiters_mutex);
1602 error = _remove_from_waiters(lkb, mstype, NULL);
1603 mutex_unlock(&ls->ls_waiters_mutex);
1604 return error;
1605}
1606
1607/* Handles situations where we might be processing a "fake" or "stub" reply in
1608 which we can't try to take waiters_mutex again. */
1609
1610static int remove_from_waiters_ms(struct dlm_lkb *lkb, struct dlm_message *ms)
1611{
1612 struct dlm_ls *ls = lkb->lkb_resource->res_ls;
1613 int error;
1614
1615 if (ms->m_flags != DLM_IFL_STUB_MS)
1616 mutex_lock(&ls->ls_waiters_mutex);
1617 error = _remove_from_waiters(lkb, ms->m_type, ms);
1618 if (ms->m_flags != DLM_IFL_STUB_MS)
1619 mutex_unlock(&ls->ls_waiters_mutex);
1620 return error;
1621}
1622
1623/* If there's an rsb for the same resource being removed, ensure
1624 that the remove message is sent before the new lookup message.
1625 It should be rare to need a delay here, but if not, then it may
1626 be worthwhile to add a proper wait mechanism rather than a delay. */
1627
1628static void wait_pending_remove(struct dlm_rsb *r)
1629{
1630 struct dlm_ls *ls = r->res_ls;
1631 restart:
1632 spin_lock(&ls->ls_remove_spin);
1633 if (ls->ls_remove_len &&
1634 !rsb_cmp(r, ls->ls_remove_name, ls->ls_remove_len)) {
1635 log_debug(ls, "delay lookup for remove dir %d %s",
1636 r->res_dir_nodeid, r->res_name);
1637 spin_unlock(&ls->ls_remove_spin);
1638 msleep(1);
1639 goto restart;
1640 }
1641 spin_unlock(&ls->ls_remove_spin);
1642}
1643
1644/*
1645 * ls_remove_spin protects ls_remove_name and ls_remove_len which are
1646 * read by other threads in wait_pending_remove. ls_remove_names
1647 * and ls_remove_lens are only used by the scan thread, so they do
1648 * not need protection.
1649 */
1650
1651static void shrink_bucket(struct dlm_ls *ls, int b)
1652{
1653 struct rb_node *n, *next;
1654 struct dlm_rsb *r;
1655 char *name;
1656 int our_nodeid = dlm_our_nodeid();
1657 int remote_count = 0;
1658 int need_shrink = 0;
1659 int i, len, rv;
1660
1661 memset(&ls->ls_remove_lens, 0, sizeof(int) * DLM_REMOVE_NAMES_MAX);
1662
1663 spin_lock(&ls->ls_rsbtbl[b].lock);
1664
1665 if (!(ls->ls_rsbtbl[b].flags & DLM_RTF_SHRINK)) {
1666 spin_unlock(&ls->ls_rsbtbl[b].lock);
1667 return;
1668 }
1669
1670 for (n = rb_first(&ls->ls_rsbtbl[b].toss); n; n = next) {
1671 next = rb_next(n);
1672 r = rb_entry(n, struct dlm_rsb, res_hashnode);
1673
1674 /* If we're the directory record for this rsb, and
1675 we're not the master of it, then we need to wait
1676 for the master node to send us a dir remove for
1677 before removing the dir record. */
1678
1679 if (!dlm_no_directory(ls) &&
1680 (r->res_master_nodeid != our_nodeid) &&
1681 (dlm_dir_nodeid(r) == our_nodeid)) {
1682 continue;
1683 }
1684
1685 need_shrink = 1;
1686
1687 if (!time_after_eq(jiffies, r->res_toss_time +
1688 dlm_config.ci_toss_secs * HZ)) {
1689 continue;
1690 }
1691
1692 if (!dlm_no_directory(ls) &&
1693 (r->res_master_nodeid == our_nodeid) &&
1694 (dlm_dir_nodeid(r) != our_nodeid)) {
1695
1696 /* We're the master of this rsb but we're not
1697 the directory record, so we need to tell the
1698 dir node to remove the dir record. */
1699
1700 ls->ls_remove_lens[remote_count] = r->res_length;
1701 memcpy(ls->ls_remove_names[remote_count], r->res_name,
1702 DLM_RESNAME_MAXLEN);
1703 remote_count++;
1704
1705 if (remote_count >= DLM_REMOVE_NAMES_MAX)
1706 break;
1707 continue;
1708 }
1709
1710 if (!kref_put(&r->res_ref, kill_rsb)) {
1711 log_error(ls, "tossed rsb in use %s", r->res_name);
1712 continue;
1713 }
1714
1715 rb_erase(&r->res_hashnode, &ls->ls_rsbtbl[b].toss);
1716 dlm_free_rsb(r);
1717 }
1718
1719 if (need_shrink)
1720 ls->ls_rsbtbl[b].flags |= DLM_RTF_SHRINK;
1721 else
1722 ls->ls_rsbtbl[b].flags &= ~DLM_RTF_SHRINK;
1723 spin_unlock(&ls->ls_rsbtbl[b].lock);
1724
1725 /*
1726 * While searching for rsb's to free, we found some that require
1727 * remote removal. We leave them in place and find them again here
1728 * so there is a very small gap between removing them from the toss
1729 * list and sending the removal. Keeping this gap small is
1730 * important to keep us (the master node) from being out of sync
1731 * with the remote dir node for very long.
1732 *
1733 * From the time the rsb is removed from toss until just after
1734 * send_remove, the rsb name is saved in ls_remove_name. A new
1735 * lookup checks this to ensure that a new lookup message for the
1736 * same resource name is not sent just before the remove message.
1737 */
1738
1739 for (i = 0; i < remote_count; i++) {
1740 name = ls->ls_remove_names[i];
1741 len = ls->ls_remove_lens[i];
1742
1743 spin_lock(&ls->ls_rsbtbl[b].lock);
1744 rv = dlm_search_rsb_tree(&ls->ls_rsbtbl[b].toss, name, len, &r);
1745 if (rv) {
1746 spin_unlock(&ls->ls_rsbtbl[b].lock);
1747 log_debug(ls, "remove_name not toss %s", name);
1748 continue;
1749 }
1750
1751 if (r->res_master_nodeid != our_nodeid) {
1752 spin_unlock(&ls->ls_rsbtbl[b].lock);
1753 log_debug(ls, "remove_name master %d dir %d our %d %s",
1754 r->res_master_nodeid, r->res_dir_nodeid,
1755 our_nodeid, name);
1756 continue;
1757 }
1758
1759 if (r->res_dir_nodeid == our_nodeid) {
1760 /* should never happen */
1761 spin_unlock(&ls->ls_rsbtbl[b].lock);
1762 log_error(ls, "remove_name dir %d master %d our %d %s",
1763 r->res_dir_nodeid, r->res_master_nodeid,
1764 our_nodeid, name);
1765 continue;
1766 }
1767
1768 if (!time_after_eq(jiffies, r->res_toss_time +
1769 dlm_config.ci_toss_secs * HZ)) {
1770 spin_unlock(&ls->ls_rsbtbl[b].lock);
1771 log_debug(ls, "remove_name toss_time %lu now %lu %s",
1772 r->res_toss_time, jiffies, name);
1773 continue;
1774 }
1775
1776 if (!kref_put(&r->res_ref, kill_rsb)) {
1777 spin_unlock(&ls->ls_rsbtbl[b].lock);
1778 log_error(ls, "remove_name in use %s", name);
1779 continue;
1780 }
1781
1782 rb_erase(&r->res_hashnode, &ls->ls_rsbtbl[b].toss);
1783
1784 /* block lookup of same name until we've sent remove */
1785 spin_lock(&ls->ls_remove_spin);
1786 ls->ls_remove_len = len;
1787 memcpy(ls->ls_remove_name, name, DLM_RESNAME_MAXLEN);
1788 spin_unlock(&ls->ls_remove_spin);
1789 spin_unlock(&ls->ls_rsbtbl[b].lock);
1790
1791 send_remove(r);
1792
1793 /* allow lookup of name again */
1794 spin_lock(&ls->ls_remove_spin);
1795 ls->ls_remove_len = 0;
1796 memset(ls->ls_remove_name, 0, DLM_RESNAME_MAXLEN);
1797 spin_unlock(&ls->ls_remove_spin);
1798
1799 dlm_free_rsb(r);
1800 }
1801}
1802
1803void dlm_scan_rsbs(struct dlm_ls *ls)
1804{
1805 int i;
1806
1807 for (i = 0; i < ls->ls_rsbtbl_size; i++) {
1808 shrink_bucket(ls, i);
1809 if (dlm_locking_stopped(ls))
1810 break;
1811 cond_resched();
1812 }
1813}
1814
1815static void add_timeout(struct dlm_lkb *lkb)
1816{
1817 struct dlm_ls *ls = lkb->lkb_resource->res_ls;
1818
1819 if (is_master_copy(lkb))
1820 return;
1821
1822 if (test_bit(LSFL_TIMEWARN, &ls->ls_flags) &&
1823 !(lkb->lkb_exflags & DLM_LKF_NODLCKWT)) {
1824 lkb->lkb_flags |= DLM_IFL_WATCH_TIMEWARN;
1825 goto add_it;
1826 }
1827 if (lkb->lkb_exflags & DLM_LKF_TIMEOUT)
1828 goto add_it;
1829 return;
1830
1831 add_it:
1832 DLM_ASSERT(list_empty(&lkb->lkb_time_list), dlm_print_lkb(lkb););
1833 mutex_lock(&ls->ls_timeout_mutex);
1834 hold_lkb(lkb);
1835 list_add_tail(&lkb->lkb_time_list, &ls->ls_timeout);
1836 mutex_unlock(&ls->ls_timeout_mutex);
1837}
1838
1839static void del_timeout(struct dlm_lkb *lkb)
1840{
1841 struct dlm_ls *ls = lkb->lkb_resource->res_ls;
1842
1843 mutex_lock(&ls->ls_timeout_mutex);
1844 if (!list_empty(&lkb->lkb_time_list)) {
1845 list_del_init(&lkb->lkb_time_list);
1846 unhold_lkb(lkb);
1847 }
1848 mutex_unlock(&ls->ls_timeout_mutex);
1849}
1850
1851/* FIXME: is it safe to look at lkb_exflags, lkb_flags, lkb_timestamp, and
1852 lkb_lksb_timeout without lock_rsb? Note: we can't lock timeout_mutex
1853 and then lock rsb because of lock ordering in add_timeout. We may need
1854 to specify some special timeout-related bits in the lkb that are just to
1855 be accessed under the timeout_mutex. */
1856
1857void dlm_scan_timeout(struct dlm_ls *ls)
1858{
1859 struct dlm_rsb *r;
1860 struct dlm_lkb *lkb;
1861 int do_cancel, do_warn;
1862 s64 wait_us;
1863
1864 for (;;) {
1865 if (dlm_locking_stopped(ls))
1866 break;
1867
1868 do_cancel = 0;
1869 do_warn = 0;
1870 mutex_lock(&ls->ls_timeout_mutex);
1871 list_for_each_entry(lkb, &ls->ls_timeout, lkb_time_list) {
1872
1873 wait_us = ktime_to_us(ktime_sub(ktime_get(),
1874 lkb->lkb_timestamp));
1875
1876 if ((lkb->lkb_exflags & DLM_LKF_TIMEOUT) &&
1877 wait_us >= (lkb->lkb_timeout_cs * 10000))
1878 do_cancel = 1;
1879
1880 if ((lkb->lkb_flags & DLM_IFL_WATCH_TIMEWARN) &&
1881 wait_us >= dlm_config.ci_timewarn_cs * 10000)
1882 do_warn = 1;
1883
1884 if (!do_cancel && !do_warn)
1885 continue;
1886 hold_lkb(lkb);
1887 break;
1888 }
1889 mutex_unlock(&ls->ls_timeout_mutex);
1890
1891 if (!do_cancel && !do_warn)
1892 break;
1893
1894 r = lkb->lkb_resource;
1895 hold_rsb(r);
1896 lock_rsb(r);
1897
1898 if (do_warn) {
1899 /* clear flag so we only warn once */
1900 lkb->lkb_flags &= ~DLM_IFL_WATCH_TIMEWARN;
1901 if (!(lkb->lkb_exflags & DLM_LKF_TIMEOUT))
1902 del_timeout(lkb);
1903 dlm_timeout_warn(lkb);
1904 }
1905
1906 if (do_cancel) {
1907 log_debug(ls, "timeout cancel %x node %d %s",
1908 lkb->lkb_id, lkb->lkb_nodeid, r->res_name);
1909 lkb->lkb_flags &= ~DLM_IFL_WATCH_TIMEWARN;
1910 lkb->lkb_flags |= DLM_IFL_TIMEOUT_CANCEL;
1911 del_timeout(lkb);
1912 _cancel_lock(r, lkb);
1913 }
1914
1915 unlock_rsb(r);
1916 unhold_rsb(r);
1917 dlm_put_lkb(lkb);
1918 }
1919}
1920
1921/* This is only called by dlm_recoverd, and we rely on dlm_ls_stop() stopping
1922 dlm_recoverd before checking/setting ls_recover_begin. */
1923
1924void dlm_adjust_timeouts(struct dlm_ls *ls)
1925{
1926 struct dlm_lkb *lkb;
1927 u64 adj_us = jiffies_to_usecs(jiffies - ls->ls_recover_begin);
1928
1929 ls->ls_recover_begin = 0;
1930 mutex_lock(&ls->ls_timeout_mutex);
1931 list_for_each_entry(lkb, &ls->ls_timeout, lkb_time_list)
1932 lkb->lkb_timestamp = ktime_add_us(lkb->lkb_timestamp, adj_us);
1933 mutex_unlock(&ls->ls_timeout_mutex);
1934
1935 if (!dlm_config.ci_waitwarn_us)
1936 return;
1937
1938 mutex_lock(&ls->ls_waiters_mutex);
1939 list_for_each_entry(lkb, &ls->ls_waiters, lkb_wait_reply) {
1940 if (ktime_to_us(lkb->lkb_wait_time))
1941 lkb->lkb_wait_time = ktime_get();
1942 }
1943 mutex_unlock(&ls->ls_waiters_mutex);
1944}
1945
1946/* lkb is master or local copy */
1947
1948static void set_lvb_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
1949{
1950 int b, len = r->res_ls->ls_lvblen;
1951
1952 /* b=1 lvb returned to caller
1953 b=0 lvb written to rsb or invalidated
1954 b=-1 do nothing */
1955
1956 b = dlm_lvb_operations[lkb->lkb_grmode + 1][lkb->lkb_rqmode + 1];
1957
1958 if (b == 1) {
1959 if (!lkb->lkb_lvbptr)
1960 return;
1961
1962 if (!(lkb->lkb_exflags & DLM_LKF_VALBLK))
1963 return;
1964
1965 if (!r->res_lvbptr)
1966 return;
1967
1968 memcpy(lkb->lkb_lvbptr, r->res_lvbptr, len);
1969 lkb->lkb_lvbseq = r->res_lvbseq;
1970
1971 } else if (b == 0) {
1972 if (lkb->lkb_exflags & DLM_LKF_IVVALBLK) {
1973 rsb_set_flag(r, RSB_VALNOTVALID);
1974 return;
1975 }
1976
1977 if (!lkb->lkb_lvbptr)
1978 return;
1979
1980 if (!(lkb->lkb_exflags & DLM_LKF_VALBLK))
1981 return;
1982
1983 if (!r->res_lvbptr)
1984 r->res_lvbptr = dlm_allocate_lvb(r->res_ls);
1985
1986 if (!r->res_lvbptr)
1987 return;
1988
1989 memcpy(r->res_lvbptr, lkb->lkb_lvbptr, len);
1990 r->res_lvbseq++;
1991 lkb->lkb_lvbseq = r->res_lvbseq;
1992 rsb_clear_flag(r, RSB_VALNOTVALID);
1993 }
1994
1995 if (rsb_flag(r, RSB_VALNOTVALID))
1996 lkb->lkb_sbflags |= DLM_SBF_VALNOTVALID;
1997}
1998
1999static void set_lvb_unlock(struct dlm_rsb *r, struct dlm_lkb *lkb)
2000{
2001 if (lkb->lkb_grmode < DLM_LOCK_PW)
2002 return;
2003
2004 if (lkb->lkb_exflags & DLM_LKF_IVVALBLK) {
2005 rsb_set_flag(r, RSB_VALNOTVALID);
2006 return;
2007 }
2008
2009 if (!lkb->lkb_lvbptr)
2010 return;
2011
2012 if (!(lkb->lkb_exflags & DLM_LKF_VALBLK))
2013 return;
2014
2015 if (!r->res_lvbptr)
2016 r->res_lvbptr = dlm_allocate_lvb(r->res_ls);
2017
2018 if (!r->res_lvbptr)
2019 return;
2020
2021 memcpy(r->res_lvbptr, lkb->lkb_lvbptr, r->res_ls->ls_lvblen);
2022 r->res_lvbseq++;
2023 rsb_clear_flag(r, RSB_VALNOTVALID);
2024}
2025
2026/* lkb is process copy (pc) */
2027
2028static void set_lvb_lock_pc(struct dlm_rsb *r, struct dlm_lkb *lkb,
2029 struct dlm_message *ms)
2030{
2031 int b;
2032
2033 if (!lkb->lkb_lvbptr)
2034 return;
2035
2036 if (!(lkb->lkb_exflags & DLM_LKF_VALBLK))
2037 return;
2038
2039 b = dlm_lvb_operations[lkb->lkb_grmode + 1][lkb->lkb_rqmode + 1];
2040 if (b == 1) {
2041 int len = receive_extralen(ms);
2042 if (len > r->res_ls->ls_lvblen)
2043 len = r->res_ls->ls_lvblen;
2044 memcpy(lkb->lkb_lvbptr, ms->m_extra, len);
2045 lkb->lkb_lvbseq = ms->m_lvbseq;
2046 }
2047}
2048
2049/* Manipulate lkb's on rsb's convert/granted/waiting queues
2050 remove_lock -- used for unlock, removes lkb from granted
2051 revert_lock -- used for cancel, moves lkb from convert to granted
2052 grant_lock -- used for request and convert, adds lkb to granted or
2053 moves lkb from convert or waiting to granted
2054
2055 Each of these is used for master or local copy lkb's. There is
2056 also a _pc() variation used to make the corresponding change on
2057 a process copy (pc) lkb. */
2058
2059static void _remove_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
2060{
2061 del_lkb(r, lkb);
2062 lkb->lkb_grmode = DLM_LOCK_IV;
2063 /* this unhold undoes the original ref from create_lkb()
2064 so this leads to the lkb being freed */
2065 unhold_lkb(lkb);
2066}
2067
2068static void remove_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
2069{
2070 set_lvb_unlock(r, lkb);
2071 _remove_lock(r, lkb);
2072}
2073
2074static void remove_lock_pc(struct dlm_rsb *r, struct dlm_lkb *lkb)
2075{
2076 _remove_lock(r, lkb);
2077}
2078
2079/* returns: 0 did nothing
2080 1 moved lock to granted
2081 -1 removed lock */
2082
2083static int revert_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
2084{
2085 int rv = 0;
2086
2087 lkb->lkb_rqmode = DLM_LOCK_IV;
2088
2089 switch (lkb->lkb_status) {
2090 case DLM_LKSTS_GRANTED:
2091 break;
2092 case DLM_LKSTS_CONVERT:
2093 move_lkb(r, lkb, DLM_LKSTS_GRANTED);
2094 rv = 1;
2095 break;
2096 case DLM_LKSTS_WAITING:
2097 del_lkb(r, lkb);
2098 lkb->lkb_grmode = DLM_LOCK_IV;
2099 /* this unhold undoes the original ref from create_lkb()
2100 so this leads to the lkb being freed */
2101 unhold_lkb(lkb);
2102 rv = -1;
2103 break;
2104 default:
2105 log_print("invalid status for revert %d", lkb->lkb_status);
2106 }
2107 return rv;
2108}
2109
2110static int revert_lock_pc(struct dlm_rsb *r, struct dlm_lkb *lkb)
2111{
2112 return revert_lock(r, lkb);
2113}
2114
2115static void _grant_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
2116{
2117 if (lkb->lkb_grmode != lkb->lkb_rqmode) {
2118 lkb->lkb_grmode = lkb->lkb_rqmode;
2119 if (lkb->lkb_status)
2120 move_lkb(r, lkb, DLM_LKSTS_GRANTED);
2121 else
2122 add_lkb(r, lkb, DLM_LKSTS_GRANTED);
2123 }
2124
2125 lkb->lkb_rqmode = DLM_LOCK_IV;
2126 lkb->lkb_highbast = 0;
2127}
2128
2129static void grant_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
2130{
2131 set_lvb_lock(r, lkb);
2132 _grant_lock(r, lkb);
2133}
2134
2135static void grant_lock_pc(struct dlm_rsb *r, struct dlm_lkb *lkb,
2136 struct dlm_message *ms)
2137{
2138 set_lvb_lock_pc(r, lkb, ms);
2139 _grant_lock(r, lkb);
2140}
2141
2142/* called by grant_pending_locks() which means an async grant message must
2143 be sent to the requesting node in addition to granting the lock if the
2144 lkb belongs to a remote node. */
2145
2146static void grant_lock_pending(struct dlm_rsb *r, struct dlm_lkb *lkb)
2147{
2148 grant_lock(r, lkb);
2149 if (is_master_copy(lkb))
2150 send_grant(r, lkb);
2151 else
2152 queue_cast(r, lkb, 0);
2153}
2154
2155/* The special CONVDEADLK, ALTPR and ALTCW flags allow the master to
2156 change the granted/requested modes. We're munging things accordingly in
2157 the process copy.
2158 CONVDEADLK: our grmode may have been forced down to NL to resolve a
2159 conversion deadlock
2160 ALTPR/ALTCW: our rqmode may have been changed to PR or CW to become
2161 compatible with other granted locks */
2162
2163static void munge_demoted(struct dlm_lkb *lkb)
2164{
2165 if (lkb->lkb_rqmode == DLM_LOCK_IV || lkb->lkb_grmode == DLM_LOCK_IV) {
2166 log_print("munge_demoted %x invalid modes gr %d rq %d",
2167 lkb->lkb_id, lkb->lkb_grmode, lkb->lkb_rqmode);
2168 return;
2169 }
2170
2171 lkb->lkb_grmode = DLM_LOCK_NL;
2172}
2173
2174static void munge_altmode(struct dlm_lkb *lkb, struct dlm_message *ms)
2175{
2176 if (ms->m_type != DLM_MSG_REQUEST_REPLY &&
2177 ms->m_type != DLM_MSG_GRANT) {
2178 log_print("munge_altmode %x invalid reply type %d",
2179 lkb->lkb_id, ms->m_type);
2180 return;
2181 }
2182
2183 if (lkb->lkb_exflags & DLM_LKF_ALTPR)
2184 lkb->lkb_rqmode = DLM_LOCK_PR;
2185 else if (lkb->lkb_exflags & DLM_LKF_ALTCW)
2186 lkb->lkb_rqmode = DLM_LOCK_CW;
2187 else {
2188 log_print("munge_altmode invalid exflags %x", lkb->lkb_exflags);
2189 dlm_print_lkb(lkb);
2190 }
2191}
2192
2193static inline int first_in_list(struct dlm_lkb *lkb, struct list_head *head)
2194{
2195 struct dlm_lkb *first = list_entry(head->next, struct dlm_lkb,
2196 lkb_statequeue);
2197 if (lkb->lkb_id == first->lkb_id)
2198 return 1;
2199
2200 return 0;
2201}
2202
2203/* Check if the given lkb conflicts with another lkb on the queue. */
2204
2205static int queue_conflict(struct list_head *head, struct dlm_lkb *lkb)
2206{
2207 struct dlm_lkb *this;
2208
2209 list_for_each_entry(this, head, lkb_statequeue) {
2210 if (this == lkb)
2211 continue;
2212 if (!modes_compat(this, lkb))
2213 return 1;
2214 }
2215 return 0;
2216}
2217
2218/*
2219 * "A conversion deadlock arises with a pair of lock requests in the converting
2220 * queue for one resource. The granted mode of each lock blocks the requested
2221 * mode of the other lock."
2222 *
2223 * Part 2: if the granted mode of lkb is preventing an earlier lkb in the
2224 * convert queue from being granted, then deadlk/demote lkb.
2225 *
2226 * Example:
2227 * Granted Queue: empty
2228 * Convert Queue: NL->EX (first lock)
2229 * PR->EX (second lock)
2230 *
2231 * The first lock can't be granted because of the granted mode of the second
2232 * lock and the second lock can't be granted because it's not first in the
2233 * list. We either cancel lkb's conversion (PR->EX) and return EDEADLK, or we
2234 * demote the granted mode of lkb (from PR to NL) if it has the CONVDEADLK
2235 * flag set and return DEMOTED in the lksb flags.
2236 *
2237 * Originally, this function detected conv-deadlk in a more limited scope:
2238 * - if !modes_compat(lkb1, lkb2) && !modes_compat(lkb2, lkb1), or
2239 * - if lkb1 was the first entry in the queue (not just earlier), and was
2240 * blocked by the granted mode of lkb2, and there was nothing on the
2241 * granted queue preventing lkb1 from being granted immediately, i.e.
2242 * lkb2 was the only thing preventing lkb1 from being granted.
2243 *
2244 * That second condition meant we'd only say there was conv-deadlk if
2245 * resolving it (by demotion) would lead to the first lock on the convert
2246 * queue being granted right away. It allowed conversion deadlocks to exist
2247 * between locks on the convert queue while they couldn't be granted anyway.
2248 *
2249 * Now, we detect and take action on conversion deadlocks immediately when
2250 * they're created, even if they may not be immediately consequential. If
2251 * lkb1 exists anywhere in the convert queue and lkb2 comes in with a granted
2252 * mode that would prevent lkb1's conversion from being granted, we do a
2253 * deadlk/demote on lkb2 right away and don't let it onto the convert queue.
2254 * I think this means that the lkb_is_ahead condition below should always
2255 * be zero, i.e. there will never be conv-deadlk between two locks that are
2256 * both already on the convert queue.
2257 */
2258
2259static int conversion_deadlock_detect(struct dlm_rsb *r, struct dlm_lkb *lkb2)
2260{
2261 struct dlm_lkb *lkb1;
2262 int lkb_is_ahead = 0;
2263
2264 list_for_each_entry(lkb1, &r->res_convertqueue, lkb_statequeue) {
2265 if (lkb1 == lkb2) {
2266 lkb_is_ahead = 1;
2267 continue;
2268 }
2269
2270 if (!lkb_is_ahead) {
2271 if (!modes_compat(lkb2, lkb1))
2272 return 1;
2273 } else {
2274 if (!modes_compat(lkb2, lkb1) &&
2275 !modes_compat(lkb1, lkb2))
2276 return 1;
2277 }
2278 }
2279 return 0;
2280}
2281
2282/*
2283 * Return 1 if the lock can be granted, 0 otherwise.
2284 * Also detect and resolve conversion deadlocks.
2285 *
2286 * lkb is the lock to be granted
2287 *
2288 * now is 1 if the function is being called in the context of the
2289 * immediate request, it is 0 if called later, after the lock has been
2290 * queued.
2291 *
2292 * recover is 1 if dlm_recover_grant() is trying to grant conversions
2293 * after recovery.
2294 *
2295 * References are from chapter 6 of "VAXcluster Principles" by Roy Davis
2296 */
2297
2298static int _can_be_granted(struct dlm_rsb *r, struct dlm_lkb *lkb, int now,
2299 int recover)
2300{
2301 int8_t conv = (lkb->lkb_grmode != DLM_LOCK_IV);
2302
2303 /*
2304 * 6-10: Version 5.4 introduced an option to address the phenomenon of
2305 * a new request for a NL mode lock being blocked.
2306 *
2307 * 6-11: If the optional EXPEDITE flag is used with the new NL mode
2308 * request, then it would be granted. In essence, the use of this flag
2309 * tells the Lock Manager to expedite theis request by not considering
2310 * what may be in the CONVERTING or WAITING queues... As of this
2311 * writing, the EXPEDITE flag can be used only with new requests for NL
2312 * mode locks. This flag is not valid for conversion requests.
2313 *
2314 * A shortcut. Earlier checks return an error if EXPEDITE is used in a
2315 * conversion or used with a non-NL requested mode. We also know an
2316 * EXPEDITE request is always granted immediately, so now must always
2317 * be 1. The full condition to grant an expedite request: (now &&
2318 * !conv && lkb->rqmode == DLM_LOCK_NL && (flags & EXPEDITE)) can
2319 * therefore be shortened to just checking the flag.
2320 */
2321
2322 if (lkb->lkb_exflags & DLM_LKF_EXPEDITE)
2323 return 1;
2324
2325 /*
2326 * A shortcut. Without this, !queue_conflict(grantqueue, lkb) would be
2327 * added to the remaining conditions.
2328 */
2329
2330 if (queue_conflict(&r->res_grantqueue, lkb))
2331 return 0;
2332
2333 /*
2334 * 6-3: By default, a conversion request is immediately granted if the
2335 * requested mode is compatible with the modes of all other granted
2336 * locks
2337 */
2338
2339 if (queue_conflict(&r->res_convertqueue, lkb))
2340 return 0;
2341
2342 /*
2343 * The RECOVER_GRANT flag means dlm_recover_grant() is granting
2344 * locks for a recovered rsb, on which lkb's have been rebuilt.
2345 * The lkb's may have been rebuilt on the queues in a different
2346 * order than they were in on the previous master. So, granting
2347 * queued conversions in order after recovery doesn't make sense
2348 * since the order hasn't been preserved anyway. The new order
2349 * could also have created a new "in place" conversion deadlock.
2350 * (e.g. old, failed master held granted EX, with PR->EX, NL->EX.
2351 * After recovery, there would be no granted locks, and possibly
2352 * NL->EX, PR->EX, an in-place conversion deadlock.) So, after
2353 * recovery, grant conversions without considering order.
2354 */
2355
2356 if (conv && recover)
2357 return 1;
2358
2359 /*
2360 * 6-5: But the default algorithm for deciding whether to grant or
2361 * queue conversion requests does not by itself guarantee that such
2362 * requests are serviced on a "first come first serve" basis. This, in
2363 * turn, can lead to a phenomenon known as "indefinate postponement".
2364 *
2365 * 6-7: This issue is dealt with by using the optional QUECVT flag with
2366 * the system service employed to request a lock conversion. This flag
2367 * forces certain conversion requests to be queued, even if they are
2368 * compatible with the granted modes of other locks on the same
2369 * resource. Thus, the use of this flag results in conversion requests
2370 * being ordered on a "first come first servce" basis.
2371 *
2372 * DCT: This condition is all about new conversions being able to occur
2373 * "in place" while the lock remains on the granted queue (assuming
2374 * nothing else conflicts.) IOW if QUECVT isn't set, a conversion
2375 * doesn't _have_ to go onto the convert queue where it's processed in
2376 * order. The "now" variable is necessary to distinguish converts
2377 * being received and processed for the first time now, because once a
2378 * convert is moved to the conversion queue the condition below applies
2379 * requiring fifo granting.
2380 */
2381
2382 if (now && conv && !(lkb->lkb_exflags & DLM_LKF_QUECVT))
2383 return 1;
2384
2385 /*
2386 * Even if the convert is compat with all granted locks,
2387 * QUECVT forces it behind other locks on the convert queue.
2388 */
2389
2390 if (now && conv && (lkb->lkb_exflags & DLM_LKF_QUECVT)) {
2391 if (list_empty(&r->res_convertqueue))
2392 return 1;
2393 else
2394 return 0;
2395 }
2396
2397 /*
2398 * The NOORDER flag is set to avoid the standard vms rules on grant
2399 * order.
2400 */
2401
2402 if (lkb->lkb_exflags & DLM_LKF_NOORDER)
2403 return 1;
2404
2405 /*
2406 * 6-3: Once in that queue [CONVERTING], a conversion request cannot be
2407 * granted until all other conversion requests ahead of it are granted
2408 * and/or canceled.
2409 */
2410
2411 if (!now && conv && first_in_list(lkb, &r->res_convertqueue))
2412 return 1;
2413
2414 /*
2415 * 6-4: By default, a new request is immediately granted only if all
2416 * three of the following conditions are satisfied when the request is
2417 * issued:
2418 * - The queue of ungranted conversion requests for the resource is
2419 * empty.
2420 * - The queue of ungranted new requests for the resource is empty.
2421 * - The mode of the new request is compatible with the most
2422 * restrictive mode of all granted locks on the resource.
2423 */
2424
2425 if (now && !conv && list_empty(&r->res_convertqueue) &&
2426 list_empty(&r->res_waitqueue))
2427 return 1;
2428
2429 /*
2430 * 6-4: Once a lock request is in the queue of ungranted new requests,
2431 * it cannot be granted until the queue of ungranted conversion
2432 * requests is empty, all ungranted new requests ahead of it are
2433 * granted and/or canceled, and it is compatible with the granted mode
2434 * of the most restrictive lock granted on the resource.
2435 */
2436
2437 if (!now && !conv && list_empty(&r->res_convertqueue) &&
2438 first_in_list(lkb, &r->res_waitqueue))
2439 return 1;
2440
2441 return 0;
2442}
2443
2444static int can_be_granted(struct dlm_rsb *r, struct dlm_lkb *lkb, int now,
2445 int recover, int *err)
2446{
2447 int rv;
2448 int8_t alt = 0, rqmode = lkb->lkb_rqmode;
2449 int8_t is_convert = (lkb->lkb_grmode != DLM_LOCK_IV);
2450
2451 if (err)
2452 *err = 0;
2453
2454 rv = _can_be_granted(r, lkb, now, recover);
2455 if (rv)
2456 goto out;
2457
2458 /*
2459 * The CONVDEADLK flag is non-standard and tells the dlm to resolve
2460 * conversion deadlocks by demoting grmode to NL, otherwise the dlm
2461 * cancels one of the locks.
2462 */
2463
2464 if (is_convert && can_be_queued(lkb) &&
2465 conversion_deadlock_detect(r, lkb)) {
2466 if (lkb->lkb_exflags & DLM_LKF_CONVDEADLK) {
2467 lkb->lkb_grmode = DLM_LOCK_NL;
2468 lkb->lkb_sbflags |= DLM_SBF_DEMOTED;
2469 } else if (!(lkb->lkb_exflags & DLM_LKF_NODLCKWT)) {
2470 if (err)
2471 *err = -EDEADLK;
2472 else {
2473 log_print("can_be_granted deadlock %x now %d",
2474 lkb->lkb_id, now);
2475 dlm_dump_rsb(r);
2476 }
2477 }
2478 goto out;
2479 }
2480
2481 /*
2482 * The ALTPR and ALTCW flags are non-standard and tell the dlm to try
2483 * to grant a request in a mode other than the normal rqmode. It's a
2484 * simple way to provide a big optimization to applications that can
2485 * use them.
2486 */
2487
2488 if (rqmode != DLM_LOCK_PR && (lkb->lkb_exflags & DLM_LKF_ALTPR))
2489 alt = DLM_LOCK_PR;
2490 else if (rqmode != DLM_LOCK_CW && (lkb->lkb_exflags & DLM_LKF_ALTCW))
2491 alt = DLM_LOCK_CW;
2492
2493 if (alt) {
2494 lkb->lkb_rqmode = alt;
2495 rv = _can_be_granted(r, lkb, now, 0);
2496 if (rv)
2497 lkb->lkb_sbflags |= DLM_SBF_ALTMODE;
2498 else
2499 lkb->lkb_rqmode = rqmode;
2500 }
2501 out:
2502 return rv;
2503}
2504
2505/* FIXME: I don't think that can_be_granted() can/will demote or find deadlock
2506 for locks pending on the convert list. Once verified (watch for these
2507 log_prints), we should be able to just call _can_be_granted() and not
2508 bother with the demote/deadlk cases here (and there's no easy way to deal
2509 with a deadlk here, we'd have to generate something like grant_lock with
2510 the deadlk error.) */
2511
2512/* Returns the highest requested mode of all blocked conversions; sets
2513 cw if there's a blocked conversion to DLM_LOCK_CW. */
2514
2515static int grant_pending_convert(struct dlm_rsb *r, int high, int *cw,
2516 unsigned int *count)
2517{
2518 struct dlm_lkb *lkb, *s;
2519 int recover = rsb_flag(r, RSB_RECOVER_GRANT);
2520 int hi, demoted, quit, grant_restart, demote_restart;
2521 int deadlk;
2522
2523 quit = 0;
2524 restart:
2525 grant_restart = 0;
2526 demote_restart = 0;
2527 hi = DLM_LOCK_IV;
2528
2529 list_for_each_entry_safe(lkb, s, &r->res_convertqueue, lkb_statequeue) {
2530 demoted = is_demoted(lkb);
2531 deadlk = 0;
2532
2533 if (can_be_granted(r, lkb, 0, recover, &deadlk)) {
2534 grant_lock_pending(r, lkb);
2535 grant_restart = 1;
2536 if (count)
2537 (*count)++;
2538 continue;
2539 }
2540
2541 if (!demoted && is_demoted(lkb)) {
2542 log_print("WARN: pending demoted %x node %d %s",
2543 lkb->lkb_id, lkb->lkb_nodeid, r->res_name);
2544 demote_restart = 1;
2545 continue;
2546 }
2547
2548 if (deadlk) {
2549 log_print("WARN: pending deadlock %x node %d %s",
2550 lkb->lkb_id, lkb->lkb_nodeid, r->res_name);
2551 dlm_dump_rsb(r);
2552 continue;
2553 }
2554
2555 hi = max_t(int, lkb->lkb_rqmode, hi);
2556
2557 if (cw && lkb->lkb_rqmode == DLM_LOCK_CW)
2558 *cw = 1;
2559 }
2560
2561 if (grant_restart)
2562 goto restart;
2563 if (demote_restart && !quit) {
2564 quit = 1;
2565 goto restart;
2566 }
2567
2568 return max_t(int, high, hi);
2569}
2570
2571static int grant_pending_wait(struct dlm_rsb *r, int high, int *cw,
2572 unsigned int *count)
2573{
2574 struct dlm_lkb *lkb, *s;
2575
2576 list_for_each_entry_safe(lkb, s, &r->res_waitqueue, lkb_statequeue) {
2577 if (can_be_granted(r, lkb, 0, 0, NULL)) {
2578 grant_lock_pending(r, lkb);
2579 if (count)
2580 (*count)++;
2581 } else {
2582 high = max_t(int, lkb->lkb_rqmode, high);
2583 if (lkb->lkb_rqmode == DLM_LOCK_CW)
2584 *cw = 1;
2585 }
2586 }
2587
2588 return high;
2589}
2590
2591/* cw of 1 means there's a lock with a rqmode of DLM_LOCK_CW that's blocked
2592 on either the convert or waiting queue.
2593 high is the largest rqmode of all locks blocked on the convert or
2594 waiting queue. */
2595
2596static int lock_requires_bast(struct dlm_lkb *gr, int high, int cw)
2597{
2598 if (gr->lkb_grmode == DLM_LOCK_PR && cw) {
2599 if (gr->lkb_highbast < DLM_LOCK_EX)
2600 return 1;
2601 return 0;
2602 }
2603
2604 if (gr->lkb_highbast < high &&
2605 !__dlm_compat_matrix[gr->lkb_grmode+1][high+1])
2606 return 1;
2607 return 0;
2608}
2609
2610static void grant_pending_locks(struct dlm_rsb *r, unsigned int *count)
2611{
2612 struct dlm_lkb *lkb, *s;
2613 int high = DLM_LOCK_IV;
2614 int cw = 0;
2615
2616 if (!is_master(r)) {
2617 log_print("grant_pending_locks r nodeid %d", r->res_nodeid);
2618 dlm_dump_rsb(r);
2619 return;
2620 }
2621
2622 high = grant_pending_convert(r, high, &cw, count);
2623 high = grant_pending_wait(r, high, &cw, count);
2624
2625 if (high == DLM_LOCK_IV)
2626 return;
2627
2628 /*
2629 * If there are locks left on the wait/convert queue then send blocking
2630 * ASTs to granted locks based on the largest requested mode (high)
2631 * found above.
2632 */
2633
2634 list_for_each_entry_safe(lkb, s, &r->res_grantqueue, lkb_statequeue) {
2635 if (lkb->lkb_bastfn && lock_requires_bast(lkb, high, cw)) {
2636 if (cw && high == DLM_LOCK_PR &&
2637 lkb->lkb_grmode == DLM_LOCK_PR)
2638 queue_bast(r, lkb, DLM_LOCK_CW);
2639 else
2640 queue_bast(r, lkb, high);
2641 lkb->lkb_highbast = high;
2642 }
2643 }
2644}
2645
2646static int modes_require_bast(struct dlm_lkb *gr, struct dlm_lkb *rq)
2647{
2648 if ((gr->lkb_grmode == DLM_LOCK_PR && rq->lkb_rqmode == DLM_LOCK_CW) ||
2649 (gr->lkb_grmode == DLM_LOCK_CW && rq->lkb_rqmode == DLM_LOCK_PR)) {
2650 if (gr->lkb_highbast < DLM_LOCK_EX)
2651 return 1;
2652 return 0;
2653 }
2654
2655 if (gr->lkb_highbast < rq->lkb_rqmode && !modes_compat(gr, rq))
2656 return 1;
2657 return 0;
2658}
2659
2660static void send_bast_queue(struct dlm_rsb *r, struct list_head *head,
2661 struct dlm_lkb *lkb)
2662{
2663 struct dlm_lkb *gr;
2664
2665 list_for_each_entry(gr, head, lkb_statequeue) {
2666 /* skip self when sending basts to convertqueue */
2667 if (gr == lkb)
2668 continue;
2669 if (gr->lkb_bastfn && modes_require_bast(gr, lkb)) {
2670 queue_bast(r, gr, lkb->lkb_rqmode);
2671 gr->lkb_highbast = lkb->lkb_rqmode;
2672 }
2673 }
2674}
2675
2676static void send_blocking_asts(struct dlm_rsb *r, struct dlm_lkb *lkb)
2677{
2678 send_bast_queue(r, &r->res_grantqueue, lkb);
2679}
2680
2681static void send_blocking_asts_all(struct dlm_rsb *r, struct dlm_lkb *lkb)
2682{
2683 send_bast_queue(r, &r->res_grantqueue, lkb);
2684 send_bast_queue(r, &r->res_convertqueue, lkb);
2685}
2686
2687/* set_master(r, lkb) -- set the master nodeid of a resource
2688
2689 The purpose of this function is to set the nodeid field in the given
2690 lkb using the nodeid field in the given rsb. If the rsb's nodeid is
2691 known, it can just be copied to the lkb and the function will return
2692 0. If the rsb's nodeid is _not_ known, it needs to be looked up
2693 before it can be copied to the lkb.
2694
2695 When the rsb nodeid is being looked up remotely, the initial lkb
2696 causing the lookup is kept on the ls_waiters list waiting for the
2697 lookup reply. Other lkb's waiting for the same rsb lookup are kept
2698 on the rsb's res_lookup list until the master is verified.
2699
2700 Return values:
2701 0: nodeid is set in rsb/lkb and the caller should go ahead and use it
2702 1: the rsb master is not available and the lkb has been placed on
2703 a wait queue
2704*/
2705
2706static int set_master(struct dlm_rsb *r, struct dlm_lkb *lkb)
2707{
2708 int our_nodeid = dlm_our_nodeid();
2709
2710 if (rsb_flag(r, RSB_MASTER_UNCERTAIN)) {
2711 rsb_clear_flag(r, RSB_MASTER_UNCERTAIN);
2712 r->res_first_lkid = lkb->lkb_id;
2713 lkb->lkb_nodeid = r->res_nodeid;
2714 return 0;
2715 }
2716
2717 if (r->res_first_lkid && r->res_first_lkid != lkb->lkb_id) {
2718 list_add_tail(&lkb->lkb_rsb_lookup, &r->res_lookup);
2719 return 1;
2720 }
2721
2722 if (r->res_master_nodeid == our_nodeid) {
2723 lkb->lkb_nodeid = 0;
2724 return 0;
2725 }
2726
2727 if (r->res_master_nodeid) {
2728 lkb->lkb_nodeid = r->res_master_nodeid;
2729 return 0;
2730 }
2731
2732 if (dlm_dir_nodeid(r) == our_nodeid) {
2733 /* This is a somewhat unusual case; find_rsb will usually
2734 have set res_master_nodeid when dir nodeid is local, but
2735 there are cases where we become the dir node after we've
2736 past find_rsb and go through _request_lock again.
2737 confirm_master() or process_lookup_list() needs to be
2738 called after this. */
2739 log_debug(r->res_ls, "set_master %x self master %d dir %d %s",
2740 lkb->lkb_id, r->res_master_nodeid, r->res_dir_nodeid,
2741 r->res_name);
2742 r->res_master_nodeid = our_nodeid;
2743 r->res_nodeid = 0;
2744 lkb->lkb_nodeid = 0;
2745 return 0;
2746 }
2747
2748 wait_pending_remove(r);
2749
2750 r->res_first_lkid = lkb->lkb_id;
2751 send_lookup(r, lkb);
2752 return 1;
2753}
2754
2755static void process_lookup_list(struct dlm_rsb *r)
2756{
2757 struct dlm_lkb *lkb, *safe;
2758
2759 list_for_each_entry_safe(lkb, safe, &r->res_lookup, lkb_rsb_lookup) {
2760 list_del_init(&lkb->lkb_rsb_lookup);
2761 _request_lock(r, lkb);
2762 schedule();
2763 }
2764}
2765
2766/* confirm_master -- confirm (or deny) an rsb's master nodeid */
2767
2768static void confirm_master(struct dlm_rsb *r, int error)
2769{
2770 struct dlm_lkb *lkb;
2771
2772 if (!r->res_first_lkid)
2773 return;
2774
2775 switch (error) {
2776 case 0:
2777 case -EINPROGRESS:
2778 r->res_first_lkid = 0;
2779 process_lookup_list(r);
2780 break;
2781
2782 case -EAGAIN:
2783 case -EBADR:
2784 case -ENOTBLK:
2785 /* the remote request failed and won't be retried (it was
2786 a NOQUEUE, or has been canceled/unlocked); make a waiting
2787 lkb the first_lkid */
2788
2789 r->res_first_lkid = 0;
2790
2791 if (!list_empty(&r->res_lookup)) {
2792 lkb = list_entry(r->res_lookup.next, struct dlm_lkb,
2793 lkb_rsb_lookup);
2794 list_del_init(&lkb->lkb_rsb_lookup);
2795 r->res_first_lkid = lkb->lkb_id;
2796 _request_lock(r, lkb);
2797 }
2798 break;
2799
2800 default:
2801 log_error(r->res_ls, "confirm_master unknown error %d", error);
2802 }
2803}
2804
2805static int set_lock_args(int mode, struct dlm_lksb *lksb, uint32_t flags,
2806 int namelen, unsigned long timeout_cs,
2807 void (*ast) (void *astparam),
2808 void *astparam,
2809 void (*bast) (void *astparam, int mode),
2810 struct dlm_args *args)
2811{
2812 int rv = -EINVAL;
2813
2814 /* check for invalid arg usage */
2815
2816 if (mode < 0 || mode > DLM_LOCK_EX)
2817 goto out;
2818
2819 if (!(flags & DLM_LKF_CONVERT) && (namelen > DLM_RESNAME_MAXLEN))
2820 goto out;
2821
2822 if (flags & DLM_LKF_CANCEL)
2823 goto out;
2824
2825 if (flags & DLM_LKF_QUECVT && !(flags & DLM_LKF_CONVERT))
2826 goto out;
2827
2828 if (flags & DLM_LKF_CONVDEADLK && !(flags & DLM_LKF_CONVERT))
2829 goto out;
2830
2831 if (flags & DLM_LKF_CONVDEADLK && flags & DLM_LKF_NOQUEUE)
2832 goto out;
2833
2834 if (flags & DLM_LKF_EXPEDITE && flags & DLM_LKF_CONVERT)
2835 goto out;
2836
2837 if (flags & DLM_LKF_EXPEDITE && flags & DLM_LKF_QUECVT)
2838 goto out;
2839
2840 if (flags & DLM_LKF_EXPEDITE && flags & DLM_LKF_NOQUEUE)
2841 goto out;
2842
2843 if (flags & DLM_LKF_EXPEDITE && mode != DLM_LOCK_NL)
2844 goto out;
2845
2846 if (!ast || !lksb)
2847 goto out;
2848
2849 if (flags & DLM_LKF_VALBLK && !lksb->sb_lvbptr)
2850 goto out;
2851
2852 if (flags & DLM_LKF_CONVERT && !lksb->sb_lkid)
2853 goto out;
2854
2855 /* these args will be copied to the lkb in validate_lock_args,
2856 it cannot be done now because when converting locks, fields in
2857 an active lkb cannot be modified before locking the rsb */
2858
2859 args->flags = flags;
2860 args->astfn = ast;
2861 args->astparam = astparam;
2862 args->bastfn = bast;
2863 args->timeout = timeout_cs;
2864 args->mode = mode;
2865 args->lksb = lksb;
2866 rv = 0;
2867 out:
2868 return rv;
2869}
2870
2871static int set_unlock_args(uint32_t flags, void *astarg, struct dlm_args *args)
2872{
2873 if (flags & ~(DLM_LKF_CANCEL | DLM_LKF_VALBLK | DLM_LKF_IVVALBLK |
2874 DLM_LKF_FORCEUNLOCK))
2875 return -EINVAL;
2876
2877 if (flags & DLM_LKF_CANCEL && flags & DLM_LKF_FORCEUNLOCK)
2878 return -EINVAL;
2879
2880 args->flags = flags;
2881 args->astparam = astarg;
2882 return 0;
2883}
2884
2885static int validate_lock_args(struct dlm_ls *ls, struct dlm_lkb *lkb,
2886 struct dlm_args *args)
2887{
2888 int rv = -EINVAL;
2889
2890 if (args->flags & DLM_LKF_CONVERT) {
2891 if (lkb->lkb_flags & DLM_IFL_MSTCPY)
2892 goto out;
2893
2894 if (args->flags & DLM_LKF_QUECVT &&
2895 !__quecvt_compat_matrix[lkb->lkb_grmode+1][args->mode+1])
2896 goto out;
2897
2898 rv = -EBUSY;
2899 if (lkb->lkb_status != DLM_LKSTS_GRANTED)
2900 goto out;
2901
2902 if (lkb->lkb_wait_type)
2903 goto out;
2904
2905 if (is_overlap(lkb))
2906 goto out;
2907 }
2908
2909 lkb->lkb_exflags = args->flags;
2910 lkb->lkb_sbflags = 0;
2911 lkb->lkb_astfn = args->astfn;
2912 lkb->lkb_astparam = args->astparam;
2913 lkb->lkb_bastfn = args->bastfn;
2914 lkb->lkb_rqmode = args->mode;
2915 lkb->lkb_lksb = args->lksb;
2916 lkb->lkb_lvbptr = args->lksb->sb_lvbptr;
2917 lkb->lkb_ownpid = (int) current->pid;
2918 lkb->lkb_timeout_cs = args->timeout;
2919 rv = 0;
2920 out:
2921 if (rv)
2922 log_debug(ls, "validate_lock_args %d %x %x %x %d %d %s",
2923 rv, lkb->lkb_id, lkb->lkb_flags, args->flags,
2924 lkb->lkb_status, lkb->lkb_wait_type,
2925 lkb->lkb_resource->res_name);
2926 return rv;
2927}
2928
2929/* when dlm_unlock() sees -EBUSY with CANCEL/FORCEUNLOCK it returns 0
2930 for success */
2931
2932/* note: it's valid for lkb_nodeid/res_nodeid to be -1 when we get here
2933 because there may be a lookup in progress and it's valid to do
2934 cancel/unlockf on it */
2935
2936static int validate_unlock_args(struct dlm_lkb *lkb, struct dlm_args *args)
2937{
2938 struct dlm_ls *ls = lkb->lkb_resource->res_ls;
2939 int rv = -EINVAL;
2940
2941 if (lkb->lkb_flags & DLM_IFL_MSTCPY) {
2942 log_error(ls, "unlock on MSTCPY %x", lkb->lkb_id);
2943 dlm_print_lkb(lkb);
2944 goto out;
2945 }
2946
2947 /* an lkb may still exist even though the lock is EOL'ed due to a
2948 cancel, unlock or failed noqueue request; an app can't use these
2949 locks; return same error as if the lkid had not been found at all */
2950
2951 if (lkb->lkb_flags & DLM_IFL_ENDOFLIFE) {
2952 log_debug(ls, "unlock on ENDOFLIFE %x", lkb->lkb_id);
2953 rv = -ENOENT;
2954 goto out;
2955 }
2956
2957 /* an lkb may be waiting for an rsb lookup to complete where the
2958 lookup was initiated by another lock */
2959
2960 if (!list_empty(&lkb->lkb_rsb_lookup)) {
2961 if (args->flags & (DLM_LKF_CANCEL | DLM_LKF_FORCEUNLOCK)) {
2962 log_debug(ls, "unlock on rsb_lookup %x", lkb->lkb_id);
2963 list_del_init(&lkb->lkb_rsb_lookup);
2964 queue_cast(lkb->lkb_resource, lkb,
2965 args->flags & DLM_LKF_CANCEL ?
2966 -DLM_ECANCEL : -DLM_EUNLOCK);
2967 unhold_lkb(lkb); /* undoes create_lkb() */
2968 }
2969 /* caller changes -EBUSY to 0 for CANCEL and FORCEUNLOCK */
2970 rv = -EBUSY;
2971 goto out;
2972 }
2973
2974 /* cancel not allowed with another cancel/unlock in progress */
2975
2976 if (args->flags & DLM_LKF_CANCEL) {
2977 if (lkb->lkb_exflags & DLM_LKF_CANCEL)
2978 goto out;
2979
2980 if (is_overlap(lkb))
2981 goto out;
2982
2983 /* don't let scand try to do a cancel */
2984 del_timeout(lkb);
2985
2986 if (lkb->lkb_flags & DLM_IFL_RESEND) {
2987 lkb->lkb_flags |= DLM_IFL_OVERLAP_CANCEL;
2988 rv = -EBUSY;
2989 goto out;
2990 }
2991
2992 /* there's nothing to cancel */
2993 if (lkb->lkb_status == DLM_LKSTS_GRANTED &&
2994 !lkb->lkb_wait_type) {
2995 rv = -EBUSY;
2996 goto out;
2997 }
2998
2999 switch (lkb->lkb_wait_type) {
3000 case DLM_MSG_LOOKUP:
3001 case DLM_MSG_REQUEST:
3002 lkb->lkb_flags |= DLM_IFL_OVERLAP_CANCEL;
3003 rv = -EBUSY;
3004 goto out;
3005 case DLM_MSG_UNLOCK:
3006 case DLM_MSG_CANCEL:
3007 goto out;
3008 }
3009 /* add_to_waiters() will set OVERLAP_CANCEL */
3010 goto out_ok;
3011 }
3012
3013 /* do we need to allow a force-unlock if there's a normal unlock
3014 already in progress? in what conditions could the normal unlock
3015 fail such that we'd want to send a force-unlock to be sure? */
3016
3017 if (args->flags & DLM_LKF_FORCEUNLOCK) {
3018 if (lkb->lkb_exflags & DLM_LKF_FORCEUNLOCK)
3019 goto out;
3020
3021 if (is_overlap_unlock(lkb))
3022 goto out;
3023
3024 /* don't let scand try to do a cancel */
3025 del_timeout(lkb);
3026
3027 if (lkb->lkb_flags & DLM_IFL_RESEND) {
3028 lkb->lkb_flags |= DLM_IFL_OVERLAP_UNLOCK;
3029 rv = -EBUSY;
3030 goto out;
3031 }
3032
3033 switch (lkb->lkb_wait_type) {
3034 case DLM_MSG_LOOKUP:
3035 case DLM_MSG_REQUEST:
3036 lkb->lkb_flags |= DLM_IFL_OVERLAP_UNLOCK;
3037 rv = -EBUSY;
3038 goto out;
3039 case DLM_MSG_UNLOCK:
3040 goto out;
3041 }
3042 /* add_to_waiters() will set OVERLAP_UNLOCK */
3043 goto out_ok;
3044 }
3045
3046 /* normal unlock not allowed if there's any op in progress */
3047 rv = -EBUSY;
3048 if (lkb->lkb_wait_type || lkb->lkb_wait_count)
3049 goto out;
3050
3051 out_ok:
3052 /* an overlapping op shouldn't blow away exflags from other op */
3053 lkb->lkb_exflags |= args->flags;
3054 lkb->lkb_sbflags = 0;
3055 lkb->lkb_astparam = args->astparam;
3056 rv = 0;
3057 out:
3058 if (rv)
3059 log_debug(ls, "validate_unlock_args %d %x %x %x %x %d %s", rv,
3060 lkb->lkb_id, lkb->lkb_flags, lkb->lkb_exflags,
3061 args->flags, lkb->lkb_wait_type,
3062 lkb->lkb_resource->res_name);
3063 return rv;
3064}
3065
3066/*
3067 * Four stage 4 varieties:
3068 * do_request(), do_convert(), do_unlock(), do_cancel()
3069 * These are called on the master node for the given lock and
3070 * from the central locking logic.
3071 */
3072
3073static int do_request(struct dlm_rsb *r, struct dlm_lkb *lkb)
3074{
3075 int error = 0;
3076
3077 if (can_be_granted(r, lkb, 1, 0, NULL)) {
3078 grant_lock(r, lkb);
3079 queue_cast(r, lkb, 0);
3080 goto out;
3081 }
3082
3083 if (can_be_queued(lkb)) {
3084 error = -EINPROGRESS;
3085 add_lkb(r, lkb, DLM_LKSTS_WAITING);
3086 add_timeout(lkb);
3087 goto out;
3088 }
3089
3090 error = -EAGAIN;
3091 queue_cast(r, lkb, -EAGAIN);
3092 out:
3093 return error;
3094}
3095
3096static void do_request_effects(struct dlm_rsb *r, struct dlm_lkb *lkb,
3097 int error)
3098{
3099 switch (error) {
3100 case -EAGAIN:
3101 if (force_blocking_asts(lkb))
3102 send_blocking_asts_all(r, lkb);
3103 break;
3104 case -EINPROGRESS:
3105 send_blocking_asts(r, lkb);
3106 break;
3107 }
3108}
3109
3110static int do_convert(struct dlm_rsb *r, struct dlm_lkb *lkb)
3111{
3112 int error = 0;
3113 int deadlk = 0;
3114
3115 /* changing an existing lock may allow others to be granted */
3116
3117 if (can_be_granted(r, lkb, 1, 0, &deadlk)) {
3118 grant_lock(r, lkb);
3119 queue_cast(r, lkb, 0);
3120 goto out;
3121 }
3122
3123 /* can_be_granted() detected that this lock would block in a conversion
3124 deadlock, so we leave it on the granted queue and return EDEADLK in
3125 the ast for the convert. */
3126
3127 if (deadlk) {
3128 /* it's left on the granted queue */
3129 revert_lock(r, lkb);
3130 queue_cast(r, lkb, -EDEADLK);
3131 error = -EDEADLK;
3132 goto out;
3133 }
3134
3135 /* is_demoted() means the can_be_granted() above set the grmode
3136 to NL, and left us on the granted queue. This auto-demotion
3137 (due to CONVDEADLK) might mean other locks, and/or this lock, are
3138 now grantable. We have to try to grant other converting locks
3139 before we try again to grant this one. */
3140
3141 if (is_demoted(lkb)) {
3142 grant_pending_convert(r, DLM_LOCK_IV, NULL, NULL);
3143 if (_can_be_granted(r, lkb, 1, 0)) {
3144 grant_lock(r, lkb);
3145 queue_cast(r, lkb, 0);
3146 goto out;
3147 }
3148 /* else fall through and move to convert queue */
3149 }
3150
3151 if (can_be_queued(lkb)) {
3152 error = -EINPROGRESS;
3153 del_lkb(r, lkb);
3154 add_lkb(r, lkb, DLM_LKSTS_CONVERT);
3155 add_timeout(lkb);
3156 goto out;
3157 }
3158
3159 error = -EAGAIN;
3160 queue_cast(r, lkb, -EAGAIN);
3161 out:
3162 return error;
3163}
3164
3165static void do_convert_effects(struct dlm_rsb *r, struct dlm_lkb *lkb,
3166 int error)
3167{
3168 switch (error) {
3169 case 0:
3170 grant_pending_locks(r, NULL);
3171 /* grant_pending_locks also sends basts */
3172 break;
3173 case -EAGAIN:
3174 if (force_blocking_asts(lkb))
3175 send_blocking_asts_all(r, lkb);
3176 break;
3177 case -EINPROGRESS:
3178 send_blocking_asts(r, lkb);
3179 break;
3180 }
3181}
3182
3183static int do_unlock(struct dlm_rsb *r, struct dlm_lkb *lkb)
3184{
3185 remove_lock(r, lkb);
3186 queue_cast(r, lkb, -DLM_EUNLOCK);
3187 return -DLM_EUNLOCK;
3188}
3189
3190static void do_unlock_effects(struct dlm_rsb *r, struct dlm_lkb *lkb,
3191 int error)
3192{
3193 grant_pending_locks(r, NULL);
3194}
3195
3196/* returns: 0 did nothing, -DLM_ECANCEL canceled lock */
3197
3198static int do_cancel(struct dlm_rsb *r, struct dlm_lkb *lkb)
3199{
3200 int error;
3201
3202 error = revert_lock(r, lkb);
3203 if (error) {
3204 queue_cast(r, lkb, -DLM_ECANCEL);
3205 return -DLM_ECANCEL;
3206 }
3207 return 0;
3208}
3209
3210static void do_cancel_effects(struct dlm_rsb *r, struct dlm_lkb *lkb,
3211 int error)
3212{
3213 if (error)
3214 grant_pending_locks(r, NULL);
3215}
3216
3217/*
3218 * Four stage 3 varieties:
3219 * _request_lock(), _convert_lock(), _unlock_lock(), _cancel_lock()
3220 */
3221
3222/* add a new lkb to a possibly new rsb, called by requesting process */
3223
3224static int _request_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
3225{
3226 int error;
3227
3228 /* set_master: sets lkb nodeid from r */
3229
3230 error = set_master(r, lkb);
3231 if (error < 0)
3232 goto out;
3233 if (error) {
3234 error = 0;
3235 goto out;
3236 }
3237
3238 if (is_remote(r)) {
3239 /* receive_request() calls do_request() on remote node */
3240 error = send_request(r, lkb);
3241 } else {
3242 error = do_request(r, lkb);
3243 /* for remote locks the request_reply is sent
3244 between do_request and do_request_effects */
3245 do_request_effects(r, lkb, error);
3246 }
3247 out:
3248 return error;
3249}
3250
3251/* change some property of an existing lkb, e.g. mode */
3252
3253static int _convert_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
3254{
3255 int error;
3256
3257 if (is_remote(r)) {
3258 /* receive_convert() calls do_convert() on remote node */
3259 error = send_convert(r, lkb);
3260 } else {
3261 error = do_convert(r, lkb);
3262 /* for remote locks the convert_reply is sent
3263 between do_convert and do_convert_effects */
3264 do_convert_effects(r, lkb, error);
3265 }
3266
3267 return error;
3268}
3269
3270/* remove an existing lkb from the granted queue */
3271
3272static int _unlock_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
3273{
3274 int error;
3275
3276 if (is_remote(r)) {
3277 /* receive_unlock() calls do_unlock() on remote node */
3278 error = send_unlock(r, lkb);
3279 } else {
3280 error = do_unlock(r, lkb);
3281 /* for remote locks the unlock_reply is sent
3282 between do_unlock and do_unlock_effects */
3283 do_unlock_effects(r, lkb, error);
3284 }
3285
3286 return error;
3287}
3288
3289/* remove an existing lkb from the convert or wait queue */
3290
3291static int _cancel_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
3292{
3293 int error;
3294
3295 if (is_remote(r)) {
3296 /* receive_cancel() calls do_cancel() on remote node */
3297 error = send_cancel(r, lkb);
3298 } else {
3299 error = do_cancel(r, lkb);
3300 /* for remote locks the cancel_reply is sent
3301 between do_cancel and do_cancel_effects */
3302 do_cancel_effects(r, lkb, error);
3303 }
3304
3305 return error;
3306}
3307
3308/*
3309 * Four stage 2 varieties:
3310 * request_lock(), convert_lock(), unlock_lock(), cancel_lock()
3311 */
3312
3313static int request_lock(struct dlm_ls *ls, struct dlm_lkb *lkb, char *name,
3314 int len, struct dlm_args *args)
3315{
3316 struct dlm_rsb *r;
3317 int error;
3318
3319 error = validate_lock_args(ls, lkb, args);
3320 if (error)
3321 return error;
3322
3323 error = find_rsb(ls, name, len, 0, R_REQUEST, &r);
3324 if (error)
3325 return error;
3326
3327 lock_rsb(r);
3328
3329 attach_lkb(r, lkb);
3330 lkb->lkb_lksb->sb_lkid = lkb->lkb_id;
3331
3332 error = _request_lock(r, lkb);
3333
3334 unlock_rsb(r);
3335 put_rsb(r);
3336 return error;
3337}
3338
3339static int convert_lock(struct dlm_ls *ls, struct dlm_lkb *lkb,
3340 struct dlm_args *args)
3341{
3342 struct dlm_rsb *r;
3343 int error;
3344
3345 r = lkb->lkb_resource;
3346
3347 hold_rsb(r);
3348 lock_rsb(r);
3349
3350 error = validate_lock_args(ls, lkb, args);
3351 if (error)
3352 goto out;
3353
3354 error = _convert_lock(r, lkb);
3355 out:
3356 unlock_rsb(r);
3357 put_rsb(r);
3358 return error;
3359}
3360
3361static int unlock_lock(struct dlm_ls *ls, struct dlm_lkb *lkb,
3362 struct dlm_args *args)
3363{
3364 struct dlm_rsb *r;
3365 int error;
3366
3367 r = lkb->lkb_resource;
3368
3369 hold_rsb(r);
3370 lock_rsb(r);
3371
3372 error = validate_unlock_args(lkb, args);
3373 if (error)
3374 goto out;
3375
3376 error = _unlock_lock(r, lkb);
3377 out:
3378 unlock_rsb(r);
3379 put_rsb(r);
3380 return error;
3381}
3382
3383static int cancel_lock(struct dlm_ls *ls, struct dlm_lkb *lkb,
3384 struct dlm_args *args)
3385{
3386 struct dlm_rsb *r;
3387 int error;
3388
3389 r = lkb->lkb_resource;
3390
3391 hold_rsb(r);
3392 lock_rsb(r);
3393
3394 error = validate_unlock_args(lkb, args);
3395 if (error)
3396 goto out;
3397
3398 error = _cancel_lock(r, lkb);
3399 out:
3400 unlock_rsb(r);
3401 put_rsb(r);
3402 return error;
3403}
3404
3405/*
3406 * Two stage 1 varieties: dlm_lock() and dlm_unlock()
3407 */
3408
3409int dlm_lock(dlm_lockspace_t *lockspace,
3410 int mode,
3411 struct dlm_lksb *lksb,
3412 uint32_t flags,
3413 void *name,
3414 unsigned int namelen,
3415 uint32_t parent_lkid,
3416 void (*ast) (void *astarg),
3417 void *astarg,
3418 void (*bast) (void *astarg, int mode))
3419{
3420 struct dlm_ls *ls;
3421 struct dlm_lkb *lkb;
3422 struct dlm_args args;
3423 int error, convert = flags & DLM_LKF_CONVERT;
3424
3425 ls = dlm_find_lockspace_local(lockspace);
3426 if (!ls)
3427 return -EINVAL;
3428
3429 dlm_lock_recovery(ls);
3430
3431 if (convert)
3432 error = find_lkb(ls, lksb->sb_lkid, &lkb);
3433 else
3434 error = create_lkb(ls, &lkb);
3435
3436 if (error)
3437 goto out;
3438
3439 error = set_lock_args(mode, lksb, flags, namelen, 0, ast,
3440 astarg, bast, &args);
3441 if (error)
3442 goto out_put;
3443
3444 if (convert)
3445 error = convert_lock(ls, lkb, &args);
3446 else
3447 error = request_lock(ls, lkb, name, namelen, &args);
3448
3449 if (error == -EINPROGRESS)
3450 error = 0;
3451 out_put:
3452 if (convert || error)
3453 __put_lkb(ls, lkb);
3454 if (error == -EAGAIN || error == -EDEADLK)
3455 error = 0;
3456 out:
3457 dlm_unlock_recovery(ls);
3458 dlm_put_lockspace(ls);
3459 return error;
3460}
3461
3462int dlm_unlock(dlm_lockspace_t *lockspace,
3463 uint32_t lkid,
3464 uint32_t flags,
3465 struct dlm_lksb *lksb,
3466 void *astarg)
3467{
3468 struct dlm_ls *ls;
3469 struct dlm_lkb *lkb;
3470 struct dlm_args args;
3471 int error;
3472
3473 ls = dlm_find_lockspace_local(lockspace);
3474 if (!ls)
3475 return -EINVAL;
3476
3477 dlm_lock_recovery(ls);
3478
3479 error = find_lkb(ls, lkid, &lkb);
3480 if (error)
3481 goto out;
3482
3483 error = set_unlock_args(flags, astarg, &args);
3484 if (error)
3485 goto out_put;
3486
3487 if (flags & DLM_LKF_CANCEL)
3488 error = cancel_lock(ls, lkb, &args);
3489 else
3490 error = unlock_lock(ls, lkb, &args);
3491
3492 if (error == -DLM_EUNLOCK || error == -DLM_ECANCEL)
3493 error = 0;
3494 if (error == -EBUSY && (flags & (DLM_LKF_CANCEL | DLM_LKF_FORCEUNLOCK)))
3495 error = 0;
3496 out_put:
3497 dlm_put_lkb(lkb);
3498 out:
3499 dlm_unlock_recovery(ls);
3500 dlm_put_lockspace(ls);
3501 return error;
3502}
3503
3504/*
3505 * send/receive routines for remote operations and replies
3506 *
3507 * send_args
3508 * send_common
3509 * send_request receive_request
3510 * send_convert receive_convert
3511 * send_unlock receive_unlock
3512 * send_cancel receive_cancel
3513 * send_grant receive_grant
3514 * send_bast receive_bast
3515 * send_lookup receive_lookup
3516 * send_remove receive_remove
3517 *
3518 * send_common_reply
3519 * receive_request_reply send_request_reply
3520 * receive_convert_reply send_convert_reply
3521 * receive_unlock_reply send_unlock_reply
3522 * receive_cancel_reply send_cancel_reply
3523 * receive_lookup_reply send_lookup_reply
3524 */
3525
3526static int _create_message(struct dlm_ls *ls, int mb_len,
3527 int to_nodeid, int mstype,
3528 struct dlm_message **ms_ret,
3529 struct dlm_mhandle **mh_ret)
3530{
3531 struct dlm_message *ms;
3532 struct dlm_mhandle *mh;
3533 char *mb;
3534
3535 /* get_buffer gives us a message handle (mh) that we need to
3536 pass into lowcomms_commit and a message buffer (mb) that we
3537 write our data into */
3538
3539 mh = dlm_lowcomms_get_buffer(to_nodeid, mb_len, GFP_NOFS, &mb);
3540 if (!mh)
3541 return -ENOBUFS;
3542
3543 memset(mb, 0, mb_len);
3544
3545 ms = (struct dlm_message *) mb;
3546
3547 ms->m_header.h_version = (DLM_HEADER_MAJOR | DLM_HEADER_MINOR);
3548 ms->m_header.h_lockspace = ls->ls_global_id;
3549 ms->m_header.h_nodeid = dlm_our_nodeid();
3550 ms->m_header.h_length = mb_len;
3551 ms->m_header.h_cmd = DLM_MSG;
3552
3553 ms->m_type = mstype;
3554
3555 *mh_ret = mh;
3556 *ms_ret = ms;
3557 return 0;
3558}
3559
3560static int create_message(struct dlm_rsb *r, struct dlm_lkb *lkb,
3561 int to_nodeid, int mstype,
3562 struct dlm_message **ms_ret,
3563 struct dlm_mhandle **mh_ret)
3564{
3565 int mb_len = sizeof(struct dlm_message);
3566
3567 switch (mstype) {
3568 case DLM_MSG_REQUEST:
3569 case DLM_MSG_LOOKUP:
3570 case DLM_MSG_REMOVE:
3571 mb_len += r->res_length;
3572 break;
3573 case DLM_MSG_CONVERT:
3574 case DLM_MSG_UNLOCK:
3575 case DLM_MSG_REQUEST_REPLY:
3576 case DLM_MSG_CONVERT_REPLY:
3577 case DLM_MSG_GRANT:
3578 if (lkb && lkb->lkb_lvbptr)
3579 mb_len += r->res_ls->ls_lvblen;
3580 break;
3581 }
3582
3583 return _create_message(r->res_ls, mb_len, to_nodeid, mstype,
3584 ms_ret, mh_ret);
3585}
3586
3587/* further lowcomms enhancements or alternate implementations may make
3588 the return value from this function useful at some point */
3589
3590static int send_message(struct dlm_mhandle *mh, struct dlm_message *ms)
3591{
3592 dlm_message_out(ms);
3593 dlm_lowcomms_commit_buffer(mh);
3594 return 0;
3595}
3596
3597static void send_args(struct dlm_rsb *r, struct dlm_lkb *lkb,
3598 struct dlm_message *ms)
3599{
3600 ms->m_nodeid = lkb->lkb_nodeid;
3601 ms->m_pid = lkb->lkb_ownpid;
3602 ms->m_lkid = lkb->lkb_id;
3603 ms->m_remid = lkb->lkb_remid;
3604 ms->m_exflags = lkb->lkb_exflags;
3605 ms->m_sbflags = lkb->lkb_sbflags;
3606 ms->m_flags = lkb->lkb_flags;
3607 ms->m_lvbseq = lkb->lkb_lvbseq;
3608 ms->m_status = lkb->lkb_status;
3609 ms->m_grmode = lkb->lkb_grmode;
3610 ms->m_rqmode = lkb->lkb_rqmode;
3611 ms->m_hash = r->res_hash;
3612
3613 /* m_result and m_bastmode are set from function args,
3614 not from lkb fields */
3615
3616 if (lkb->lkb_bastfn)
3617 ms->m_asts |= DLM_CB_BAST;
3618 if (lkb->lkb_astfn)
3619 ms->m_asts |= DLM_CB_CAST;
3620
3621 /* compare with switch in create_message; send_remove() doesn't
3622 use send_args() */
3623
3624 switch (ms->m_type) {
3625 case DLM_MSG_REQUEST:
3626 case DLM_MSG_LOOKUP:
3627 memcpy(ms->m_extra, r->res_name, r->res_length);
3628 break;
3629 case DLM_MSG_CONVERT:
3630 case DLM_MSG_UNLOCK:
3631 case DLM_MSG_REQUEST_REPLY:
3632 case DLM_MSG_CONVERT_REPLY:
3633 case DLM_MSG_GRANT:
3634 if (!lkb->lkb_lvbptr)
3635 break;
3636 memcpy(ms->m_extra, lkb->lkb_lvbptr, r->res_ls->ls_lvblen);
3637 break;
3638 }
3639}
3640
3641static int send_common(struct dlm_rsb *r, struct dlm_lkb *lkb, int mstype)
3642{
3643 struct dlm_message *ms;
3644 struct dlm_mhandle *mh;
3645 int to_nodeid, error;
3646
3647 to_nodeid = r->res_nodeid;
3648
3649 error = add_to_waiters(lkb, mstype, to_nodeid);
3650 if (error)
3651 return error;
3652
3653 error = create_message(r, lkb, to_nodeid, mstype, &ms, &mh);
3654 if (error)
3655 goto fail;
3656
3657 send_args(r, lkb, ms);
3658
3659 error = send_message(mh, ms);
3660 if (error)
3661 goto fail;
3662 return 0;
3663
3664 fail:
3665 remove_from_waiters(lkb, msg_reply_type(mstype));
3666 return error;
3667}
3668
3669static int send_request(struct dlm_rsb *r, struct dlm_lkb *lkb)
3670{
3671 return send_common(r, lkb, DLM_MSG_REQUEST);
3672}
3673
3674static int send_convert(struct dlm_rsb *r, struct dlm_lkb *lkb)
3675{
3676 int error;
3677
3678 error = send_common(r, lkb, DLM_MSG_CONVERT);
3679
3680 /* down conversions go without a reply from the master */
3681 if (!error && down_conversion(lkb)) {
3682 remove_from_waiters(lkb, DLM_MSG_CONVERT_REPLY);
3683 r->res_ls->ls_stub_ms.m_flags = DLM_IFL_STUB_MS;
3684 r->res_ls->ls_stub_ms.m_type = DLM_MSG_CONVERT_REPLY;
3685 r->res_ls->ls_stub_ms.m_result = 0;
3686 __receive_convert_reply(r, lkb, &r->res_ls->ls_stub_ms);
3687 }
3688
3689 return error;
3690}
3691
3692/* FIXME: if this lkb is the only lock we hold on the rsb, then set
3693 MASTER_UNCERTAIN to force the next request on the rsb to confirm
3694 that the master is still correct. */
3695
3696static int send_unlock(struct dlm_rsb *r, struct dlm_lkb *lkb)
3697{
3698 return send_common(r, lkb, DLM_MSG_UNLOCK);
3699}
3700
3701static int send_cancel(struct dlm_rsb *r, struct dlm_lkb *lkb)
3702{
3703 return send_common(r, lkb, DLM_MSG_CANCEL);
3704}
3705
3706static int send_grant(struct dlm_rsb *r, struct dlm_lkb *lkb)
3707{
3708 struct dlm_message *ms;
3709 struct dlm_mhandle *mh;
3710 int to_nodeid, error;
3711
3712 to_nodeid = lkb->lkb_nodeid;
3713
3714 error = create_message(r, lkb, to_nodeid, DLM_MSG_GRANT, &ms, &mh);
3715 if (error)
3716 goto out;
3717
3718 send_args(r, lkb, ms);
3719
3720 ms->m_result = 0;
3721
3722 error = send_message(mh, ms);
3723 out:
3724 return error;
3725}
3726
3727static int send_bast(struct dlm_rsb *r, struct dlm_lkb *lkb, int mode)
3728{
3729 struct dlm_message *ms;
3730 struct dlm_mhandle *mh;
3731 int to_nodeid, error;
3732
3733 to_nodeid = lkb->lkb_nodeid;
3734
3735 error = create_message(r, NULL, to_nodeid, DLM_MSG_BAST, &ms, &mh);
3736 if (error)
3737 goto out;
3738
3739 send_args(r, lkb, ms);
3740
3741 ms->m_bastmode = mode;
3742
3743 error = send_message(mh, ms);
3744 out:
3745 return error;
3746}
3747
3748static int send_lookup(struct dlm_rsb *r, struct dlm_lkb *lkb)
3749{
3750 struct dlm_message *ms;
3751 struct dlm_mhandle *mh;
3752 int to_nodeid, error;
3753
3754 to_nodeid = dlm_dir_nodeid(r);
3755
3756 error = add_to_waiters(lkb, DLM_MSG_LOOKUP, to_nodeid);
3757 if (error)
3758 return error;
3759
3760 error = create_message(r, NULL, to_nodeid, DLM_MSG_LOOKUP, &ms, &mh);
3761 if (error)
3762 goto fail;
3763
3764 send_args(r, lkb, ms);
3765
3766 error = send_message(mh, ms);
3767 if (error)
3768 goto fail;
3769 return 0;
3770
3771 fail:
3772 remove_from_waiters(lkb, DLM_MSG_LOOKUP_REPLY);
3773 return error;
3774}
3775
3776static int send_remove(struct dlm_rsb *r)
3777{
3778 struct dlm_message *ms;
3779 struct dlm_mhandle *mh;
3780 int to_nodeid, error;
3781
3782 to_nodeid = dlm_dir_nodeid(r);
3783
3784 error = create_message(r, NULL, to_nodeid, DLM_MSG_REMOVE, &ms, &mh);
3785 if (error)
3786 goto out;
3787
3788 memcpy(ms->m_extra, r->res_name, r->res_length);
3789 ms->m_hash = r->res_hash;
3790
3791 error = send_message(mh, ms);
3792 out:
3793 return error;
3794}
3795
3796static int send_common_reply(struct dlm_rsb *r, struct dlm_lkb *lkb,
3797 int mstype, int rv)
3798{
3799 struct dlm_message *ms;
3800 struct dlm_mhandle *mh;
3801 int to_nodeid, error;
3802
3803 to_nodeid = lkb->lkb_nodeid;
3804
3805 error = create_message(r, lkb, to_nodeid, mstype, &ms, &mh);
3806 if (error)
3807 goto out;
3808
3809 send_args(r, lkb, ms);
3810
3811 ms->m_result = rv;
3812
3813 error = send_message(mh, ms);
3814 out:
3815 return error;
3816}
3817
3818static int send_request_reply(struct dlm_rsb *r, struct dlm_lkb *lkb, int rv)
3819{
3820 return send_common_reply(r, lkb, DLM_MSG_REQUEST_REPLY, rv);
3821}
3822
3823static int send_convert_reply(struct dlm_rsb *r, struct dlm_lkb *lkb, int rv)
3824{
3825 return send_common_reply(r, lkb, DLM_MSG_CONVERT_REPLY, rv);
3826}
3827
3828static int send_unlock_reply(struct dlm_rsb *r, struct dlm_lkb *lkb, int rv)
3829{
3830 return send_common_reply(r, lkb, DLM_MSG_UNLOCK_REPLY, rv);
3831}
3832
3833static int send_cancel_reply(struct dlm_rsb *r, struct dlm_lkb *lkb, int rv)
3834{
3835 return send_common_reply(r, lkb, DLM_MSG_CANCEL_REPLY, rv);
3836}
3837
3838static int send_lookup_reply(struct dlm_ls *ls, struct dlm_message *ms_in,
3839 int ret_nodeid, int rv)
3840{
3841 struct dlm_rsb *r = &ls->ls_stub_rsb;
3842 struct dlm_message *ms;
3843 struct dlm_mhandle *mh;
3844 int error, nodeid = ms_in->m_header.h_nodeid;
3845
3846 error = create_message(r, NULL, nodeid, DLM_MSG_LOOKUP_REPLY, &ms, &mh);
3847 if (error)
3848 goto out;
3849
3850 ms->m_lkid = ms_in->m_lkid;
3851 ms->m_result = rv;
3852 ms->m_nodeid = ret_nodeid;
3853
3854 error = send_message(mh, ms);
3855 out:
3856 return error;
3857}
3858
3859/* which args we save from a received message depends heavily on the type
3860 of message, unlike the send side where we can safely send everything about
3861 the lkb for any type of message */
3862
3863static void receive_flags(struct dlm_lkb *lkb, struct dlm_message *ms)
3864{
3865 lkb->lkb_exflags = ms->m_exflags;
3866 lkb->lkb_sbflags = ms->m_sbflags;
3867 lkb->lkb_flags = (lkb->lkb_flags & 0xFFFF0000) |
3868 (ms->m_flags & 0x0000FFFF);
3869}
3870
3871static void receive_flags_reply(struct dlm_lkb *lkb, struct dlm_message *ms)
3872{
3873 if (ms->m_flags == DLM_IFL_STUB_MS)
3874 return;
3875
3876 lkb->lkb_sbflags = ms->m_sbflags;
3877 lkb->lkb_flags = (lkb->lkb_flags & 0xFFFF0000) |
3878 (ms->m_flags & 0x0000FFFF);
3879}
3880
3881static int receive_extralen(struct dlm_message *ms)
3882{
3883 return (ms->m_header.h_length - sizeof(struct dlm_message));
3884}
3885
3886static int receive_lvb(struct dlm_ls *ls, struct dlm_lkb *lkb,
3887 struct dlm_message *ms)
3888{
3889 int len;
3890
3891 if (lkb->lkb_exflags & DLM_LKF_VALBLK) {
3892 if (!lkb->lkb_lvbptr)
3893 lkb->lkb_lvbptr = dlm_allocate_lvb(ls);
3894 if (!lkb->lkb_lvbptr)
3895 return -ENOMEM;
3896 len = receive_extralen(ms);
3897 if (len > ls->ls_lvblen)
3898 len = ls->ls_lvblen;
3899 memcpy(lkb->lkb_lvbptr, ms->m_extra, len);
3900 }
3901 return 0;
3902}
3903
3904static void fake_bastfn(void *astparam, int mode)
3905{
3906 log_print("fake_bastfn should not be called");
3907}
3908
3909static void fake_astfn(void *astparam)
3910{
3911 log_print("fake_astfn should not be called");
3912}
3913
3914static int receive_request_args(struct dlm_ls *ls, struct dlm_lkb *lkb,
3915 struct dlm_message *ms)
3916{
3917 lkb->lkb_nodeid = ms->m_header.h_nodeid;
3918 lkb->lkb_ownpid = ms->m_pid;
3919 lkb->lkb_remid = ms->m_lkid;
3920 lkb->lkb_grmode = DLM_LOCK_IV;
3921 lkb->lkb_rqmode = ms->m_rqmode;
3922
3923 lkb->lkb_bastfn = (ms->m_asts & DLM_CB_BAST) ? &fake_bastfn : NULL;
3924 lkb->lkb_astfn = (ms->m_asts & DLM_CB_CAST) ? &fake_astfn : NULL;
3925
3926 if (lkb->lkb_exflags & DLM_LKF_VALBLK) {
3927 /* lkb was just created so there won't be an lvb yet */
3928 lkb->lkb_lvbptr = dlm_allocate_lvb(ls);
3929 if (!lkb->lkb_lvbptr)
3930 return -ENOMEM;
3931 }
3932
3933 return 0;
3934}
3935
3936static int receive_convert_args(struct dlm_ls *ls, struct dlm_lkb *lkb,
3937 struct dlm_message *ms)
3938{
3939 if (lkb->lkb_status != DLM_LKSTS_GRANTED)
3940 return -EBUSY;
3941
3942 if (receive_lvb(ls, lkb, ms))
3943 return -ENOMEM;
3944
3945 lkb->lkb_rqmode = ms->m_rqmode;
3946 lkb->lkb_lvbseq = ms->m_lvbseq;
3947
3948 return 0;
3949}
3950
3951static int receive_unlock_args(struct dlm_ls *ls, struct dlm_lkb *lkb,
3952 struct dlm_message *ms)
3953{
3954 if (receive_lvb(ls, lkb, ms))
3955 return -ENOMEM;
3956 return 0;
3957}
3958
3959/* We fill in the stub-lkb fields with the info that send_xxxx_reply()
3960 uses to send a reply and that the remote end uses to process the reply. */
3961
3962static void setup_stub_lkb(struct dlm_ls *ls, struct dlm_message *ms)
3963{
3964 struct dlm_lkb *lkb = &ls->ls_stub_lkb;
3965 lkb->lkb_nodeid = ms->m_header.h_nodeid;
3966 lkb->lkb_remid = ms->m_lkid;
3967}
3968
3969/* This is called after the rsb is locked so that we can safely inspect
3970 fields in the lkb. */
3971
3972static int validate_message(struct dlm_lkb *lkb, struct dlm_message *ms)
3973{
3974 int from = ms->m_header.h_nodeid;
3975 int error = 0;
3976
3977 switch (ms->m_type) {
3978 case DLM_MSG_CONVERT:
3979 case DLM_MSG_UNLOCK:
3980 case DLM_MSG_CANCEL:
3981 if (!is_master_copy(lkb) || lkb->lkb_nodeid != from)
3982 error = -EINVAL;
3983 break;
3984
3985 case DLM_MSG_CONVERT_REPLY:
3986 case DLM_MSG_UNLOCK_REPLY:
3987 case DLM_MSG_CANCEL_REPLY:
3988 case DLM_MSG_GRANT:
3989 case DLM_MSG_BAST:
3990 if (!is_process_copy(lkb) || lkb->lkb_nodeid != from)
3991 error = -EINVAL;
3992 break;
3993
3994 case DLM_MSG_REQUEST_REPLY:
3995 if (!is_process_copy(lkb))
3996 error = -EINVAL;
3997 else if (lkb->lkb_nodeid != -1 && lkb->lkb_nodeid != from)
3998 error = -EINVAL;
3999 break;
4000
4001 default:
4002 error = -EINVAL;
4003 }
4004
4005 if (error)
4006 log_error(lkb->lkb_resource->res_ls,
4007 "ignore invalid message %d from %d %x %x %x %d",
4008 ms->m_type, from, lkb->lkb_id, lkb->lkb_remid,
4009 lkb->lkb_flags, lkb->lkb_nodeid);
4010 return error;
4011}
4012
4013static void send_repeat_remove(struct dlm_ls *ls, char *ms_name, int len)
4014{
4015 char name[DLM_RESNAME_MAXLEN + 1];
4016 struct dlm_message *ms;
4017 struct dlm_mhandle *mh;
4018 struct dlm_rsb *r;
4019 uint32_t hash, b;
4020 int rv, dir_nodeid;
4021
4022 memset(name, 0, sizeof(name));
4023 memcpy(name, ms_name, len);
4024
4025 hash = jhash(name, len, 0);
4026 b = hash & (ls->ls_rsbtbl_size - 1);
4027
4028 dir_nodeid = dlm_hash2nodeid(ls, hash);
4029
4030 log_error(ls, "send_repeat_remove dir %d %s", dir_nodeid, name);
4031
4032 spin_lock(&ls->ls_rsbtbl[b].lock);
4033 rv = dlm_search_rsb_tree(&ls->ls_rsbtbl[b].keep, name, len, &r);
4034 if (!rv) {
4035 spin_unlock(&ls->ls_rsbtbl[b].lock);
4036 log_error(ls, "repeat_remove on keep %s", name);
4037 return;
4038 }
4039
4040 rv = dlm_search_rsb_tree(&ls->ls_rsbtbl[b].toss, name, len, &r);
4041 if (!rv) {
4042 spin_unlock(&ls->ls_rsbtbl[b].lock);
4043 log_error(ls, "repeat_remove on toss %s", name);
4044 return;
4045 }
4046
4047 /* use ls->remove_name2 to avoid conflict with shrink? */
4048
4049 spin_lock(&ls->ls_remove_spin);
4050 ls->ls_remove_len = len;
4051 memcpy(ls->ls_remove_name, name, DLM_RESNAME_MAXLEN);
4052 spin_unlock(&ls->ls_remove_spin);
4053 spin_unlock(&ls->ls_rsbtbl[b].lock);
4054
4055 rv = _create_message(ls, sizeof(struct dlm_message) + len,
4056 dir_nodeid, DLM_MSG_REMOVE, &ms, &mh);
4057 if (rv)
4058 return;
4059
4060 memcpy(ms->m_extra, name, len);
4061 ms->m_hash = hash;
4062
4063 send_message(mh, ms);
4064
4065 spin_lock(&ls->ls_remove_spin);
4066 ls->ls_remove_len = 0;
4067 memset(ls->ls_remove_name, 0, DLM_RESNAME_MAXLEN);
4068 spin_unlock(&ls->ls_remove_spin);
4069}
4070
4071static int receive_request(struct dlm_ls *ls, struct dlm_message *ms)
4072{
4073 struct dlm_lkb *lkb;
4074 struct dlm_rsb *r;
4075 int from_nodeid;
4076 int error, namelen = 0;
4077
4078 from_nodeid = ms->m_header.h_nodeid;
4079
4080 error = create_lkb(ls, &lkb);
4081 if (error)
4082 goto fail;
4083
4084 receive_flags(lkb, ms);
4085 lkb->lkb_flags |= DLM_IFL_MSTCPY;
4086 error = receive_request_args(ls, lkb, ms);
4087 if (error) {
4088 __put_lkb(ls, lkb);
4089 goto fail;
4090 }
4091
4092 /* The dir node is the authority on whether we are the master
4093 for this rsb or not, so if the master sends us a request, we should
4094 recreate the rsb if we've destroyed it. This race happens when we
4095 send a remove message to the dir node at the same time that the dir
4096 node sends us a request for the rsb. */
4097
4098 namelen = receive_extralen(ms);
4099
4100 error = find_rsb(ls, ms->m_extra, namelen, from_nodeid,
4101 R_RECEIVE_REQUEST, &r);
4102 if (error) {
4103 __put_lkb(ls, lkb);
4104 goto fail;
4105 }
4106
4107 lock_rsb(r);
4108
4109 if (r->res_master_nodeid != dlm_our_nodeid()) {
4110 error = validate_master_nodeid(ls, r, from_nodeid);
4111 if (error) {
4112 unlock_rsb(r);
4113 put_rsb(r);
4114 __put_lkb(ls, lkb);
4115 goto fail;
4116 }
4117 }
4118
4119 attach_lkb(r, lkb);
4120 error = do_request(r, lkb);
4121 send_request_reply(r, lkb, error);
4122 do_request_effects(r, lkb, error);
4123
4124 unlock_rsb(r);
4125 put_rsb(r);
4126
4127 if (error == -EINPROGRESS)
4128 error = 0;
4129 if (error)
4130 dlm_put_lkb(lkb);
4131 return 0;
4132
4133 fail:
4134 /* TODO: instead of returning ENOTBLK, add the lkb to res_lookup
4135 and do this receive_request again from process_lookup_list once
4136 we get the lookup reply. This would avoid a many repeated
4137 ENOTBLK request failures when the lookup reply designating us
4138 as master is delayed. */
4139
4140 /* We could repeatedly return -EBADR here if our send_remove() is
4141 delayed in being sent/arriving/being processed on the dir node.
4142 Another node would repeatedly lookup up the master, and the dir
4143 node would continue returning our nodeid until our send_remove
4144 took effect.
4145
4146 We send another remove message in case our previous send_remove
4147 was lost/ignored/missed somehow. */
4148
4149 if (error != -ENOTBLK) {
4150 log_limit(ls, "receive_request %x from %d %d",
4151 ms->m_lkid, from_nodeid, error);
4152 }
4153
4154 if (namelen && error == -EBADR) {
4155 send_repeat_remove(ls, ms->m_extra, namelen);
4156 msleep(1000);
4157 }
4158
4159 setup_stub_lkb(ls, ms);
4160 send_request_reply(&ls->ls_stub_rsb, &ls->ls_stub_lkb, error);
4161 return error;
4162}
4163
4164static int receive_convert(struct dlm_ls *ls, struct dlm_message *ms)
4165{
4166 struct dlm_lkb *lkb;
4167 struct dlm_rsb *r;
4168 int error, reply = 1;
4169
4170 error = find_lkb(ls, ms->m_remid, &lkb);
4171 if (error)
4172 goto fail;
4173
4174 if (lkb->lkb_remid != ms->m_lkid) {
4175 log_error(ls, "receive_convert %x remid %x recover_seq %llu "
4176 "remote %d %x", lkb->lkb_id, lkb->lkb_remid,
4177 (unsigned long long)lkb->lkb_recover_seq,
4178 ms->m_header.h_nodeid, ms->m_lkid);
4179 error = -ENOENT;
4180 goto fail;
4181 }
4182
4183 r = lkb->lkb_resource;
4184
4185 hold_rsb(r);
4186 lock_rsb(r);
4187
4188 error = validate_message(lkb, ms);
4189 if (error)
4190 goto out;
4191
4192 receive_flags(lkb, ms);
4193
4194 error = receive_convert_args(ls, lkb, ms);
4195 if (error) {
4196 send_convert_reply(r, lkb, error);
4197 goto out;
4198 }
4199
4200 reply = !down_conversion(lkb);
4201
4202 error = do_convert(r, lkb);
4203 if (reply)
4204 send_convert_reply(r, lkb, error);
4205 do_convert_effects(r, lkb, error);
4206 out:
4207 unlock_rsb(r);
4208 put_rsb(r);
4209 dlm_put_lkb(lkb);
4210 return 0;
4211
4212 fail:
4213 setup_stub_lkb(ls, ms);
4214 send_convert_reply(&ls->ls_stub_rsb, &ls->ls_stub_lkb, error);
4215 return error;
4216}
4217
4218static int receive_unlock(struct dlm_ls *ls, struct dlm_message *ms)
4219{
4220 struct dlm_lkb *lkb;
4221 struct dlm_rsb *r;
4222 int error;
4223
4224 error = find_lkb(ls, ms->m_remid, &lkb);
4225 if (error)
4226 goto fail;
4227
4228 if (lkb->lkb_remid != ms->m_lkid) {
4229 log_error(ls, "receive_unlock %x remid %x remote %d %x",
4230 lkb->lkb_id, lkb->lkb_remid,
4231 ms->m_header.h_nodeid, ms->m_lkid);
4232 error = -ENOENT;
4233 goto fail;
4234 }
4235
4236 r = lkb->lkb_resource;
4237
4238 hold_rsb(r);
4239 lock_rsb(r);
4240
4241 error = validate_message(lkb, ms);
4242 if (error)
4243 goto out;
4244
4245 receive_flags(lkb, ms);
4246
4247 error = receive_unlock_args(ls, lkb, ms);
4248 if (error) {
4249 send_unlock_reply(r, lkb, error);
4250 goto out;
4251 }
4252
4253 error = do_unlock(r, lkb);
4254 send_unlock_reply(r, lkb, error);
4255 do_unlock_effects(r, lkb, error);
4256 out:
4257 unlock_rsb(r);
4258 put_rsb(r);
4259 dlm_put_lkb(lkb);
4260 return 0;
4261
4262 fail:
4263 setup_stub_lkb(ls, ms);
4264 send_unlock_reply(&ls->ls_stub_rsb, &ls->ls_stub_lkb, error);
4265 return error;
4266}
4267
4268static int receive_cancel(struct dlm_ls *ls, struct dlm_message *ms)
4269{
4270 struct dlm_lkb *lkb;
4271 struct dlm_rsb *r;
4272 int error;
4273
4274 error = find_lkb(ls, ms->m_remid, &lkb);
4275 if (error)
4276 goto fail;
4277
4278 receive_flags(lkb, ms);
4279
4280 r = lkb->lkb_resource;
4281
4282 hold_rsb(r);
4283 lock_rsb(r);
4284
4285 error = validate_message(lkb, ms);
4286 if (error)
4287 goto out;
4288
4289 error = do_cancel(r, lkb);
4290 send_cancel_reply(r, lkb, error);
4291 do_cancel_effects(r, lkb, error);
4292 out:
4293 unlock_rsb(r);
4294 put_rsb(r);
4295 dlm_put_lkb(lkb);
4296 return 0;
4297
4298 fail:
4299 setup_stub_lkb(ls, ms);
4300 send_cancel_reply(&ls->ls_stub_rsb, &ls->ls_stub_lkb, error);
4301 return error;
4302}
4303
4304static int receive_grant(struct dlm_ls *ls, struct dlm_message *ms)
4305{
4306 struct dlm_lkb *lkb;
4307 struct dlm_rsb *r;
4308 int error;
4309
4310 error = find_lkb(ls, ms->m_remid, &lkb);
4311 if (error)
4312 return error;
4313
4314 r = lkb->lkb_resource;
4315
4316 hold_rsb(r);
4317 lock_rsb(r);
4318
4319 error = validate_message(lkb, ms);
4320 if (error)
4321 goto out;
4322
4323 receive_flags_reply(lkb, ms);
4324 if (is_altmode(lkb))
4325 munge_altmode(lkb, ms);
4326 grant_lock_pc(r, lkb, ms);
4327 queue_cast(r, lkb, 0);
4328 out:
4329 unlock_rsb(r);
4330 put_rsb(r);
4331 dlm_put_lkb(lkb);
4332 return 0;
4333}
4334
4335static int receive_bast(struct dlm_ls *ls, struct dlm_message *ms)
4336{
4337 struct dlm_lkb *lkb;
4338 struct dlm_rsb *r;
4339 int error;
4340
4341 error = find_lkb(ls, ms->m_remid, &lkb);
4342 if (error)
4343 return error;
4344
4345 r = lkb->lkb_resource;
4346
4347 hold_rsb(r);
4348 lock_rsb(r);
4349
4350 error = validate_message(lkb, ms);
4351 if (error)
4352 goto out;
4353
4354 queue_bast(r, lkb, ms->m_bastmode);
4355 lkb->lkb_highbast = ms->m_bastmode;
4356 out:
4357 unlock_rsb(r);
4358 put_rsb(r);
4359 dlm_put_lkb(lkb);
4360 return 0;
4361}
4362
4363static void receive_lookup(struct dlm_ls *ls, struct dlm_message *ms)
4364{
4365 int len, error, ret_nodeid, from_nodeid, our_nodeid;
4366
4367 from_nodeid = ms->m_header.h_nodeid;
4368 our_nodeid = dlm_our_nodeid();
4369
4370 len = receive_extralen(ms);
4371
4372 error = dlm_master_lookup(ls, from_nodeid, ms->m_extra, len, 0,
4373 &ret_nodeid, NULL);
4374
4375 /* Optimization: we're master so treat lookup as a request */
4376 if (!error && ret_nodeid == our_nodeid) {
4377 receive_request(ls, ms);
4378 return;
4379 }
4380 send_lookup_reply(ls, ms, ret_nodeid, error);
4381}
4382
4383static void receive_remove(struct dlm_ls *ls, struct dlm_message *ms)
4384{
4385 char name[DLM_RESNAME_MAXLEN+1];
4386 struct dlm_rsb *r;
4387 uint32_t hash, b;
4388 int rv, len, dir_nodeid, from_nodeid;
4389
4390 from_nodeid = ms->m_header.h_nodeid;
4391
4392 len = receive_extralen(ms);
4393
4394 if (len > DLM_RESNAME_MAXLEN) {
4395 log_error(ls, "receive_remove from %d bad len %d",
4396 from_nodeid, len);
4397 return;
4398 }
4399
4400 dir_nodeid = dlm_hash2nodeid(ls, ms->m_hash);
4401 if (dir_nodeid != dlm_our_nodeid()) {
4402 log_error(ls, "receive_remove from %d bad nodeid %d",
4403 from_nodeid, dir_nodeid);
4404 return;
4405 }
4406
4407 /* Look for name on rsbtbl.toss, if it's there, kill it.
4408 If it's on rsbtbl.keep, it's being used, and we should ignore this
4409 message. This is an expected race between the dir node sending a
4410 request to the master node at the same time as the master node sends
4411 a remove to the dir node. The resolution to that race is for the
4412 dir node to ignore the remove message, and the master node to
4413 recreate the master rsb when it gets a request from the dir node for
4414 an rsb it doesn't have. */
4415
4416 memset(name, 0, sizeof(name));
4417 memcpy(name, ms->m_extra, len);
4418
4419 hash = jhash(name, len, 0);
4420 b = hash & (ls->ls_rsbtbl_size - 1);
4421
4422 spin_lock(&ls->ls_rsbtbl[b].lock);
4423
4424 rv = dlm_search_rsb_tree(&ls->ls_rsbtbl[b].toss, name, len, &r);
4425 if (rv) {
4426 /* verify the rsb is on keep list per comment above */
4427 rv = dlm_search_rsb_tree(&ls->ls_rsbtbl[b].keep, name, len, &r);
4428 if (rv) {
4429 /* should not happen */
4430 log_error(ls, "receive_remove from %d not found %s",
4431 from_nodeid, name);
4432 spin_unlock(&ls->ls_rsbtbl[b].lock);
4433 return;
4434 }
4435 if (r->res_master_nodeid != from_nodeid) {
4436 /* should not happen */
4437 log_error(ls, "receive_remove keep from %d master %d",
4438 from_nodeid, r->res_master_nodeid);
4439 dlm_print_rsb(r);
4440 spin_unlock(&ls->ls_rsbtbl[b].lock);
4441 return;
4442 }
4443
4444 log_debug(ls, "receive_remove from %d master %d first %x %s",
4445 from_nodeid, r->res_master_nodeid, r->res_first_lkid,
4446 name);
4447 spin_unlock(&ls->ls_rsbtbl[b].lock);
4448 return;
4449 }
4450
4451 if (r->res_master_nodeid != from_nodeid) {
4452 log_error(ls, "receive_remove toss from %d master %d",
4453 from_nodeid, r->res_master_nodeid);
4454 dlm_print_rsb(r);
4455 spin_unlock(&ls->ls_rsbtbl[b].lock);
4456 return;
4457 }
4458
4459 if (kref_put(&r->res_ref, kill_rsb)) {
4460 rb_erase(&r->res_hashnode, &ls->ls_rsbtbl[b].toss);
4461 spin_unlock(&ls->ls_rsbtbl[b].lock);
4462 dlm_free_rsb(r);
4463 } else {
4464 log_error(ls, "receive_remove from %d rsb ref error",
4465 from_nodeid);
4466 dlm_print_rsb(r);
4467 spin_unlock(&ls->ls_rsbtbl[b].lock);
4468 }
4469}
4470
4471static void receive_purge(struct dlm_ls *ls, struct dlm_message *ms)
4472{
4473 do_purge(ls, ms->m_nodeid, ms->m_pid);
4474}
4475
4476static int receive_request_reply(struct dlm_ls *ls, struct dlm_message *ms)
4477{
4478 struct dlm_lkb *lkb;
4479 struct dlm_rsb *r;
4480 int error, mstype, result;
4481 int from_nodeid = ms->m_header.h_nodeid;
4482
4483 error = find_lkb(ls, ms->m_remid, &lkb);
4484 if (error)
4485 return error;
4486
4487 r = lkb->lkb_resource;
4488 hold_rsb(r);
4489 lock_rsb(r);
4490
4491 error = validate_message(lkb, ms);
4492 if (error)
4493 goto out;
4494
4495 mstype = lkb->lkb_wait_type;
4496 error = remove_from_waiters(lkb, DLM_MSG_REQUEST_REPLY);
4497 if (error) {
4498 log_error(ls, "receive_request_reply %x remote %d %x result %d",
4499 lkb->lkb_id, from_nodeid, ms->m_lkid, ms->m_result);
4500 dlm_dump_rsb(r);
4501 goto out;
4502 }
4503
4504 /* Optimization: the dir node was also the master, so it took our
4505 lookup as a request and sent request reply instead of lookup reply */
4506 if (mstype == DLM_MSG_LOOKUP) {
4507 r->res_master_nodeid = from_nodeid;
4508 r->res_nodeid = from_nodeid;
4509 lkb->lkb_nodeid = from_nodeid;
4510 }
4511
4512 /* this is the value returned from do_request() on the master */
4513 result = ms->m_result;
4514
4515 switch (result) {
4516 case -EAGAIN:
4517 /* request would block (be queued) on remote master */
4518 queue_cast(r, lkb, -EAGAIN);
4519 confirm_master(r, -EAGAIN);
4520 unhold_lkb(lkb); /* undoes create_lkb() */
4521 break;
4522
4523 case -EINPROGRESS:
4524 case 0:
4525 /* request was queued or granted on remote master */
4526 receive_flags_reply(lkb, ms);
4527 lkb->lkb_remid = ms->m_lkid;
4528 if (is_altmode(lkb))
4529 munge_altmode(lkb, ms);
4530 if (result) {
4531 add_lkb(r, lkb, DLM_LKSTS_WAITING);
4532 add_timeout(lkb);
4533 } else {
4534 grant_lock_pc(r, lkb, ms);
4535 queue_cast(r, lkb, 0);
4536 }
4537 confirm_master(r, result);
4538 break;
4539
4540 case -EBADR:
4541 case -ENOTBLK:
4542 /* find_rsb failed to find rsb or rsb wasn't master */
4543 log_limit(ls, "receive_request_reply %x from %d %d "
4544 "master %d dir %d first %x %s", lkb->lkb_id,
4545 from_nodeid, result, r->res_master_nodeid,
4546 r->res_dir_nodeid, r->res_first_lkid, r->res_name);
4547
4548 if (r->res_dir_nodeid != dlm_our_nodeid() &&
4549 r->res_master_nodeid != dlm_our_nodeid()) {
4550 /* cause _request_lock->set_master->send_lookup */
4551 r->res_master_nodeid = 0;
4552 r->res_nodeid = -1;
4553 lkb->lkb_nodeid = -1;
4554 }
4555
4556 if (is_overlap(lkb)) {
4557 /* we'll ignore error in cancel/unlock reply */
4558 queue_cast_overlap(r, lkb);
4559 confirm_master(r, result);
4560 unhold_lkb(lkb); /* undoes create_lkb() */
4561 } else {
4562 _request_lock(r, lkb);
4563
4564 if (r->res_master_nodeid == dlm_our_nodeid())
4565 confirm_master(r, 0);
4566 }
4567 break;
4568
4569 default:
4570 log_error(ls, "receive_request_reply %x error %d",
4571 lkb->lkb_id, result);
4572 }
4573
4574 if (is_overlap_unlock(lkb) && (result == 0 || result == -EINPROGRESS)) {
4575 log_debug(ls, "receive_request_reply %x result %d unlock",
4576 lkb->lkb_id, result);
4577 lkb->lkb_flags &= ~DLM_IFL_OVERLAP_UNLOCK;
4578 lkb->lkb_flags &= ~DLM_IFL_OVERLAP_CANCEL;
4579 send_unlock(r, lkb);
4580 } else if (is_overlap_cancel(lkb) && (result == -EINPROGRESS)) {
4581 log_debug(ls, "receive_request_reply %x cancel", lkb->lkb_id);
4582 lkb->lkb_flags &= ~DLM_IFL_OVERLAP_UNLOCK;
4583 lkb->lkb_flags &= ~DLM_IFL_OVERLAP_CANCEL;
4584 send_cancel(r, lkb);
4585 } else {
4586 lkb->lkb_flags &= ~DLM_IFL_OVERLAP_CANCEL;
4587 lkb->lkb_flags &= ~DLM_IFL_OVERLAP_UNLOCK;
4588 }
4589 out:
4590 unlock_rsb(r);
4591 put_rsb(r);
4592 dlm_put_lkb(lkb);
4593 return 0;
4594}
4595
4596static void __receive_convert_reply(struct dlm_rsb *r, struct dlm_lkb *lkb,
4597 struct dlm_message *ms)
4598{
4599 /* this is the value returned from do_convert() on the master */
4600 switch (ms->m_result) {
4601 case -EAGAIN:
4602 /* convert would block (be queued) on remote master */
4603 queue_cast(r, lkb, -EAGAIN);
4604 break;
4605
4606 case -EDEADLK:
4607 receive_flags_reply(lkb, ms);
4608 revert_lock_pc(r, lkb);
4609 queue_cast(r, lkb, -EDEADLK);
4610 break;
4611
4612 case -EINPROGRESS:
4613 /* convert was queued on remote master */
4614 receive_flags_reply(lkb, ms);
4615 if (is_demoted(lkb))
4616 munge_demoted(lkb);
4617 del_lkb(r, lkb);
4618 add_lkb(r, lkb, DLM_LKSTS_CONVERT);
4619 add_timeout(lkb);
4620 break;
4621
4622 case 0:
4623 /* convert was granted on remote master */
4624 receive_flags_reply(lkb, ms);
4625 if (is_demoted(lkb))
4626 munge_demoted(lkb);
4627 grant_lock_pc(r, lkb, ms);
4628 queue_cast(r, lkb, 0);
4629 break;
4630
4631 default:
4632 log_error(r->res_ls, "receive_convert_reply %x remote %d %x %d",
4633 lkb->lkb_id, ms->m_header.h_nodeid, ms->m_lkid,
4634 ms->m_result);
4635 dlm_print_rsb(r);
4636 dlm_print_lkb(lkb);
4637 }
4638}
4639
4640static void _receive_convert_reply(struct dlm_lkb *lkb, struct dlm_message *ms)
4641{
4642 struct dlm_rsb *r = lkb->lkb_resource;
4643 int error;
4644
4645 hold_rsb(r);
4646 lock_rsb(r);
4647
4648 error = validate_message(lkb, ms);
4649 if (error)
4650 goto out;
4651
4652 /* stub reply can happen with waiters_mutex held */
4653 error = remove_from_waiters_ms(lkb, ms);
4654 if (error)
4655 goto out;
4656
4657 __receive_convert_reply(r, lkb, ms);
4658 out:
4659 unlock_rsb(r);
4660 put_rsb(r);
4661}
4662
4663static int receive_convert_reply(struct dlm_ls *ls, struct dlm_message *ms)
4664{
4665 struct dlm_lkb *lkb;
4666 int error;
4667
4668 error = find_lkb(ls, ms->m_remid, &lkb);
4669 if (error)
4670 return error;
4671
4672 _receive_convert_reply(lkb, ms);
4673 dlm_put_lkb(lkb);
4674 return 0;
4675}
4676
4677static void _receive_unlock_reply(struct dlm_lkb *lkb, struct dlm_message *ms)
4678{
4679 struct dlm_rsb *r = lkb->lkb_resource;
4680 int error;
4681
4682 hold_rsb(r);
4683 lock_rsb(r);
4684
4685 error = validate_message(lkb, ms);
4686 if (error)
4687 goto out;
4688
4689 /* stub reply can happen with waiters_mutex held */
4690 error = remove_from_waiters_ms(lkb, ms);
4691 if (error)
4692 goto out;
4693
4694 /* this is the value returned from do_unlock() on the master */
4695
4696 switch (ms->m_result) {
4697 case -DLM_EUNLOCK:
4698 receive_flags_reply(lkb, ms);
4699 remove_lock_pc(r, lkb);
4700 queue_cast(r, lkb, -DLM_EUNLOCK);
4701 break;
4702 case -ENOENT:
4703 break;
4704 default:
4705 log_error(r->res_ls, "receive_unlock_reply %x error %d",
4706 lkb->lkb_id, ms->m_result);
4707 }
4708 out:
4709 unlock_rsb(r);
4710 put_rsb(r);
4711}
4712
4713static int receive_unlock_reply(struct dlm_ls *ls, struct dlm_message *ms)
4714{
4715 struct dlm_lkb *lkb;
4716 int error;
4717
4718 error = find_lkb(ls, ms->m_remid, &lkb);
4719 if (error)
4720 return error;
4721
4722 _receive_unlock_reply(lkb, ms);
4723 dlm_put_lkb(lkb);
4724 return 0;
4725}
4726
4727static void _receive_cancel_reply(struct dlm_lkb *lkb, struct dlm_message *ms)
4728{
4729 struct dlm_rsb *r = lkb->lkb_resource;
4730 int error;
4731
4732 hold_rsb(r);
4733 lock_rsb(r);
4734
4735 error = validate_message(lkb, ms);
4736 if (error)
4737 goto out;
4738
4739 /* stub reply can happen with waiters_mutex held */
4740 error = remove_from_waiters_ms(lkb, ms);
4741 if (error)
4742 goto out;
4743
4744 /* this is the value returned from do_cancel() on the master */
4745
4746 switch (ms->m_result) {
4747 case -DLM_ECANCEL:
4748 receive_flags_reply(lkb, ms);
4749 revert_lock_pc(r, lkb);
4750 queue_cast(r, lkb, -DLM_ECANCEL);
4751 break;
4752 case 0:
4753 break;
4754 default:
4755 log_error(r->res_ls, "receive_cancel_reply %x error %d",
4756 lkb->lkb_id, ms->m_result);
4757 }
4758 out:
4759 unlock_rsb(r);
4760 put_rsb(r);
4761}
4762
4763static int receive_cancel_reply(struct dlm_ls *ls, struct dlm_message *ms)
4764{
4765 struct dlm_lkb *lkb;
4766 int error;
4767
4768 error = find_lkb(ls, ms->m_remid, &lkb);
4769 if (error)
4770 return error;
4771
4772 _receive_cancel_reply(lkb, ms);
4773 dlm_put_lkb(lkb);
4774 return 0;
4775}
4776
4777static void receive_lookup_reply(struct dlm_ls *ls, struct dlm_message *ms)
4778{
4779 struct dlm_lkb *lkb;
4780 struct dlm_rsb *r;
4781 int error, ret_nodeid;
4782 int do_lookup_list = 0;
4783
4784 error = find_lkb(ls, ms->m_lkid, &lkb);
4785 if (error) {
4786 log_error(ls, "receive_lookup_reply no lkid %x", ms->m_lkid);
4787 return;
4788 }
4789
4790 /* ms->m_result is the value returned by dlm_master_lookup on dir node
4791 FIXME: will a non-zero error ever be returned? */
4792
4793 r = lkb->lkb_resource;
4794 hold_rsb(r);
4795 lock_rsb(r);
4796
4797 error = remove_from_waiters(lkb, DLM_MSG_LOOKUP_REPLY);
4798 if (error)
4799 goto out;
4800
4801 ret_nodeid = ms->m_nodeid;
4802
4803 /* We sometimes receive a request from the dir node for this
4804 rsb before we've received the dir node's loookup_reply for it.
4805 The request from the dir node implies we're the master, so we set
4806 ourself as master in receive_request_reply, and verify here that
4807 we are indeed the master. */
4808
4809 if (r->res_master_nodeid && (r->res_master_nodeid != ret_nodeid)) {
4810 /* This should never happen */
4811 log_error(ls, "receive_lookup_reply %x from %d ret %d "
4812 "master %d dir %d our %d first %x %s",
4813 lkb->lkb_id, ms->m_header.h_nodeid, ret_nodeid,
4814 r->res_master_nodeid, r->res_dir_nodeid,
4815 dlm_our_nodeid(), r->res_first_lkid, r->res_name);
4816 }
4817
4818 if (ret_nodeid == dlm_our_nodeid()) {
4819 r->res_master_nodeid = ret_nodeid;
4820 r->res_nodeid = 0;
4821 do_lookup_list = 1;
4822 r->res_first_lkid = 0;
4823 } else if (ret_nodeid == -1) {
4824 /* the remote node doesn't believe it's the dir node */
4825 log_error(ls, "receive_lookup_reply %x from %d bad ret_nodeid",
4826 lkb->lkb_id, ms->m_header.h_nodeid);
4827 r->res_master_nodeid = 0;
4828 r->res_nodeid = -1;
4829 lkb->lkb_nodeid = -1;
4830 } else {
4831 /* set_master() will set lkb_nodeid from r */
4832 r->res_master_nodeid = ret_nodeid;
4833 r->res_nodeid = ret_nodeid;
4834 }
4835
4836 if (is_overlap(lkb)) {
4837 log_debug(ls, "receive_lookup_reply %x unlock %x",
4838 lkb->lkb_id, lkb->lkb_flags);
4839 queue_cast_overlap(r, lkb);
4840 unhold_lkb(lkb); /* undoes create_lkb() */
4841 goto out_list;
4842 }
4843
4844 _request_lock(r, lkb);
4845
4846 out_list:
4847 if (do_lookup_list)
4848 process_lookup_list(r);
4849 out:
4850 unlock_rsb(r);
4851 put_rsb(r);
4852 dlm_put_lkb(lkb);
4853}
4854
4855static void _receive_message(struct dlm_ls *ls, struct dlm_message *ms,
4856 uint32_t saved_seq)
4857{
4858 int error = 0, noent = 0;
4859
4860 if (!dlm_is_member(ls, ms->m_header.h_nodeid)) {
4861 log_limit(ls, "receive %d from non-member %d %x %x %d",
4862 ms->m_type, ms->m_header.h_nodeid, ms->m_lkid,
4863 ms->m_remid, ms->m_result);
4864 return;
4865 }
4866
4867 switch (ms->m_type) {
4868
4869 /* messages sent to a master node */
4870
4871 case DLM_MSG_REQUEST:
4872 error = receive_request(ls, ms);
4873 break;
4874
4875 case DLM_MSG_CONVERT:
4876 error = receive_convert(ls, ms);
4877 break;
4878
4879 case DLM_MSG_UNLOCK:
4880 error = receive_unlock(ls, ms);
4881 break;
4882
4883 case DLM_MSG_CANCEL:
4884 noent = 1;
4885 error = receive_cancel(ls, ms);
4886 break;
4887
4888 /* messages sent from a master node (replies to above) */
4889
4890 case DLM_MSG_REQUEST_REPLY:
4891 error = receive_request_reply(ls, ms);
4892 break;
4893
4894 case DLM_MSG_CONVERT_REPLY:
4895 error = receive_convert_reply(ls, ms);
4896 break;
4897
4898 case DLM_MSG_UNLOCK_REPLY:
4899 error = receive_unlock_reply(ls, ms);
4900 break;
4901
4902 case DLM_MSG_CANCEL_REPLY:
4903 error = receive_cancel_reply(ls, ms);
4904 break;
4905
4906 /* messages sent from a master node (only two types of async msg) */
4907
4908 case DLM_MSG_GRANT:
4909 noent = 1;
4910 error = receive_grant(ls, ms);
4911 break;
4912
4913 case DLM_MSG_BAST:
4914 noent = 1;
4915 error = receive_bast(ls, ms);
4916 break;
4917
4918 /* messages sent to a dir node */
4919
4920 case DLM_MSG_LOOKUP:
4921 receive_lookup(ls, ms);
4922 break;
4923
4924 case DLM_MSG_REMOVE:
4925 receive_remove(ls, ms);
4926 break;
4927
4928 /* messages sent from a dir node (remove has no reply) */
4929
4930 case DLM_MSG_LOOKUP_REPLY:
4931 receive_lookup_reply(ls, ms);
4932 break;
4933
4934 /* other messages */
4935
4936 case DLM_MSG_PURGE:
4937 receive_purge(ls, ms);
4938 break;
4939
4940 default:
4941 log_error(ls, "unknown message type %d", ms->m_type);
4942 }
4943
4944 /*
4945 * When checking for ENOENT, we're checking the result of
4946 * find_lkb(m_remid):
4947 *
4948 * The lock id referenced in the message wasn't found. This may
4949 * happen in normal usage for the async messages and cancel, so
4950 * only use log_debug for them.
4951 *
4952 * Some errors are expected and normal.
4953 */
4954
4955 if (error == -ENOENT && noent) {
4956 log_debug(ls, "receive %d no %x remote %d %x saved_seq %u",
4957 ms->m_type, ms->m_remid, ms->m_header.h_nodeid,
4958 ms->m_lkid, saved_seq);
4959 } else if (error == -ENOENT) {
4960 log_error(ls, "receive %d no %x remote %d %x saved_seq %u",
4961 ms->m_type, ms->m_remid, ms->m_header.h_nodeid,
4962 ms->m_lkid, saved_seq);
4963
4964 if (ms->m_type == DLM_MSG_CONVERT)
4965 dlm_dump_rsb_hash(ls, ms->m_hash);
4966 }
4967
4968 if (error == -EINVAL) {
4969 log_error(ls, "receive %d inval from %d lkid %x remid %x "
4970 "saved_seq %u",
4971 ms->m_type, ms->m_header.h_nodeid,
4972 ms->m_lkid, ms->m_remid, saved_seq);
4973 }
4974}
4975
4976/* If the lockspace is in recovery mode (locking stopped), then normal
4977 messages are saved on the requestqueue for processing after recovery is
4978 done. When not in recovery mode, we wait for dlm_recoverd to drain saved
4979 messages off the requestqueue before we process new ones. This occurs right
4980 after recovery completes when we transition from saving all messages on
4981 requestqueue, to processing all the saved messages, to processing new
4982 messages as they arrive. */
4983
4984static void dlm_receive_message(struct dlm_ls *ls, struct dlm_message *ms,
4985 int nodeid)
4986{
4987 if (dlm_locking_stopped(ls)) {
4988 /* If we were a member of this lockspace, left, and rejoined,
4989 other nodes may still be sending us messages from the
4990 lockspace generation before we left. */
4991 if (!ls->ls_generation) {
4992 log_limit(ls, "receive %d from %d ignore old gen",
4993 ms->m_type, nodeid);
4994 return;
4995 }
4996
4997 dlm_add_requestqueue(ls, nodeid, ms);
4998 } else {
4999 dlm_wait_requestqueue(ls);
5000 _receive_message(ls, ms, 0);
5001 }
5002}
5003
5004/* This is called by dlm_recoverd to process messages that were saved on
5005 the requestqueue. */
5006
5007void dlm_receive_message_saved(struct dlm_ls *ls, struct dlm_message *ms,
5008 uint32_t saved_seq)
5009{
5010 _receive_message(ls, ms, saved_seq);
5011}
5012
5013/* This is called by the midcomms layer when something is received for
5014 the lockspace. It could be either a MSG (normal message sent as part of
5015 standard locking activity) or an RCOM (recovery message sent as part of
5016 lockspace recovery). */
5017
5018void dlm_receive_buffer(union dlm_packet *p, int nodeid)
5019{
5020 struct dlm_header *hd = &p->header;
5021 struct dlm_ls *ls;
5022 int type = 0;
5023
5024 switch (hd->h_cmd) {
5025 case DLM_MSG:
5026 dlm_message_in(&p->message);
5027 type = p->message.m_type;
5028 break;
5029 case DLM_RCOM:
5030 dlm_rcom_in(&p->rcom);
5031 type = p->rcom.rc_type;
5032 break;
5033 default:
5034 log_print("invalid h_cmd %d from %u", hd->h_cmd, nodeid);
5035 return;
5036 }
5037
5038 if (hd->h_nodeid != nodeid) {
5039 log_print("invalid h_nodeid %d from %d lockspace %x",
5040 hd->h_nodeid, nodeid, hd->h_lockspace);
5041 return;
5042 }
5043
5044 ls = dlm_find_lockspace_global(hd->h_lockspace);
5045 if (!ls) {
5046 if (dlm_config.ci_log_debug) {
5047 printk_ratelimited(KERN_DEBUG "dlm: invalid lockspace "
5048 "%u from %d cmd %d type %d\n",
5049 hd->h_lockspace, nodeid, hd->h_cmd, type);
5050 }
5051
5052 if (hd->h_cmd == DLM_RCOM && type == DLM_RCOM_STATUS)
5053 dlm_send_ls_not_ready(nodeid, &p->rcom);
5054 return;
5055 }
5056
5057 /* this rwsem allows dlm_ls_stop() to wait for all dlm_recv threads to
5058 be inactive (in this ls) before transitioning to recovery mode */
5059
5060 down_read(&ls->ls_recv_active);
5061 if (hd->h_cmd == DLM_MSG)
5062 dlm_receive_message(ls, &p->message, nodeid);
5063 else
5064 dlm_receive_rcom(ls, &p->rcom, nodeid);
5065 up_read(&ls->ls_recv_active);
5066
5067 dlm_put_lockspace(ls);
5068}
5069
5070static void recover_convert_waiter(struct dlm_ls *ls, struct dlm_lkb *lkb,
5071 struct dlm_message *ms_stub)
5072{
5073 if (middle_conversion(lkb)) {
5074 hold_lkb(lkb);
5075 memset(ms_stub, 0, sizeof(struct dlm_message));
5076 ms_stub->m_flags = DLM_IFL_STUB_MS;
5077 ms_stub->m_type = DLM_MSG_CONVERT_REPLY;
5078 ms_stub->m_result = -EINPROGRESS;
5079 ms_stub->m_header.h_nodeid = lkb->lkb_nodeid;
5080 _receive_convert_reply(lkb, ms_stub);
5081
5082 /* Same special case as in receive_rcom_lock_args() */
5083 lkb->lkb_grmode = DLM_LOCK_IV;
5084 rsb_set_flag(lkb->lkb_resource, RSB_RECOVER_CONVERT);
5085 unhold_lkb(lkb);
5086
5087 } else if (lkb->lkb_rqmode >= lkb->lkb_grmode) {
5088 lkb->lkb_flags |= DLM_IFL_RESEND;
5089 }
5090
5091 /* lkb->lkb_rqmode < lkb->lkb_grmode shouldn't happen since down
5092 conversions are async; there's no reply from the remote master */
5093}
5094
5095/* A waiting lkb needs recovery if the master node has failed, or
5096 the master node is changing (only when no directory is used) */
5097
5098static int waiter_needs_recovery(struct dlm_ls *ls, struct dlm_lkb *lkb,
5099 int dir_nodeid)
5100{
5101 if (dlm_no_directory(ls))
5102 return 1;
5103
5104 if (dlm_is_removed(ls, lkb->lkb_wait_nodeid))
5105 return 1;
5106
5107 return 0;
5108}
5109
5110/* Recovery for locks that are waiting for replies from nodes that are now
5111 gone. We can just complete unlocks and cancels by faking a reply from the
5112 dead node. Requests and up-conversions we flag to be resent after
5113 recovery. Down-conversions can just be completed with a fake reply like
5114 unlocks. Conversions between PR and CW need special attention. */
5115
5116void dlm_recover_waiters_pre(struct dlm_ls *ls)
5117{
5118 struct dlm_lkb *lkb, *safe;
5119 struct dlm_message *ms_stub;
5120 int wait_type, stub_unlock_result, stub_cancel_result;
5121 int dir_nodeid;
5122
5123 ms_stub = kmalloc(sizeof(struct dlm_message), GFP_KERNEL);
5124 if (!ms_stub) {
5125 log_error(ls, "dlm_recover_waiters_pre no mem");
5126 return;
5127 }
5128
5129 mutex_lock(&ls->ls_waiters_mutex);
5130
5131 list_for_each_entry_safe(lkb, safe, &ls->ls_waiters, lkb_wait_reply) {
5132
5133 dir_nodeid = dlm_dir_nodeid(lkb->lkb_resource);
5134
5135 /* exclude debug messages about unlocks because there can be so
5136 many and they aren't very interesting */
5137
5138 if (lkb->lkb_wait_type != DLM_MSG_UNLOCK) {
5139 log_debug(ls, "waiter %x remote %x msg %d r_nodeid %d "
5140 "lkb_nodeid %d wait_nodeid %d dir_nodeid %d",
5141 lkb->lkb_id,
5142 lkb->lkb_remid,
5143 lkb->lkb_wait_type,
5144 lkb->lkb_resource->res_nodeid,
5145 lkb->lkb_nodeid,
5146 lkb->lkb_wait_nodeid,
5147 dir_nodeid);
5148 }
5149
5150 /* all outstanding lookups, regardless of destination will be
5151 resent after recovery is done */
5152
5153 if (lkb->lkb_wait_type == DLM_MSG_LOOKUP) {
5154 lkb->lkb_flags |= DLM_IFL_RESEND;
5155 continue;
5156 }
5157
5158 if (!waiter_needs_recovery(ls, lkb, dir_nodeid))
5159 continue;
5160
5161 wait_type = lkb->lkb_wait_type;
5162 stub_unlock_result = -DLM_EUNLOCK;
5163 stub_cancel_result = -DLM_ECANCEL;
5164
5165 /* Main reply may have been received leaving a zero wait_type,
5166 but a reply for the overlapping op may not have been
5167 received. In that case we need to fake the appropriate
5168 reply for the overlap op. */
5169
5170 if (!wait_type) {
5171 if (is_overlap_cancel(lkb)) {
5172 wait_type = DLM_MSG_CANCEL;
5173 if (lkb->lkb_grmode == DLM_LOCK_IV)
5174 stub_cancel_result = 0;
5175 }
5176 if (is_overlap_unlock(lkb)) {
5177 wait_type = DLM_MSG_UNLOCK;
5178 if (lkb->lkb_grmode == DLM_LOCK_IV)
5179 stub_unlock_result = -ENOENT;
5180 }
5181
5182 log_debug(ls, "rwpre overlap %x %x %d %d %d",
5183 lkb->lkb_id, lkb->lkb_flags, wait_type,
5184 stub_cancel_result, stub_unlock_result);
5185 }
5186
5187 switch (wait_type) {
5188
5189 case DLM_MSG_REQUEST:
5190 lkb->lkb_flags |= DLM_IFL_RESEND;
5191 break;
5192
5193 case DLM_MSG_CONVERT:
5194 recover_convert_waiter(ls, lkb, ms_stub);
5195 break;
5196
5197 case DLM_MSG_UNLOCK:
5198 hold_lkb(lkb);
5199 memset(ms_stub, 0, sizeof(struct dlm_message));
5200 ms_stub->m_flags = DLM_IFL_STUB_MS;
5201 ms_stub->m_type = DLM_MSG_UNLOCK_REPLY;
5202 ms_stub->m_result = stub_unlock_result;
5203 ms_stub->m_header.h_nodeid = lkb->lkb_nodeid;
5204 _receive_unlock_reply(lkb, ms_stub);
5205 dlm_put_lkb(lkb);
5206 break;
5207
5208 case DLM_MSG_CANCEL:
5209 hold_lkb(lkb);
5210 memset(ms_stub, 0, sizeof(struct dlm_message));
5211 ms_stub->m_flags = DLM_IFL_STUB_MS;
5212 ms_stub->m_type = DLM_MSG_CANCEL_REPLY;
5213 ms_stub->m_result = stub_cancel_result;
5214 ms_stub->m_header.h_nodeid = lkb->lkb_nodeid;
5215 _receive_cancel_reply(lkb, ms_stub);
5216 dlm_put_lkb(lkb);
5217 break;
5218
5219 default:
5220 log_error(ls, "invalid lkb wait_type %d %d",
5221 lkb->lkb_wait_type, wait_type);
5222 }
5223 schedule();
5224 }
5225 mutex_unlock(&ls->ls_waiters_mutex);
5226 kfree(ms_stub);
5227}
5228
5229static struct dlm_lkb *find_resend_waiter(struct dlm_ls *ls)
5230{
5231 struct dlm_lkb *lkb;
5232 int found = 0;
5233
5234 mutex_lock(&ls->ls_waiters_mutex);
5235 list_for_each_entry(lkb, &ls->ls_waiters, lkb_wait_reply) {
5236 if (lkb->lkb_flags & DLM_IFL_RESEND) {
5237 hold_lkb(lkb);
5238 found = 1;
5239 break;
5240 }
5241 }
5242 mutex_unlock(&ls->ls_waiters_mutex);
5243
5244 if (!found)
5245 lkb = NULL;
5246 return lkb;
5247}
5248
5249/* Deal with lookups and lkb's marked RESEND from _pre. We may now be the
5250 master or dir-node for r. Processing the lkb may result in it being placed
5251 back on waiters. */
5252
5253/* We do this after normal locking has been enabled and any saved messages
5254 (in requestqueue) have been processed. We should be confident that at
5255 this point we won't get or process a reply to any of these waiting
5256 operations. But, new ops may be coming in on the rsbs/locks here from
5257 userspace or remotely. */
5258
5259/* there may have been an overlap unlock/cancel prior to recovery or after
5260 recovery. if before, the lkb may still have a pos wait_count; if after, the
5261 overlap flag would just have been set and nothing new sent. we can be
5262 confident here than any replies to either the initial op or overlap ops
5263 prior to recovery have been received. */
5264
5265int dlm_recover_waiters_post(struct dlm_ls *ls)
5266{
5267 struct dlm_lkb *lkb;
5268 struct dlm_rsb *r;
5269 int error = 0, mstype, err, oc, ou;
5270
5271 while (1) {
5272 if (dlm_locking_stopped(ls)) {
5273 log_debug(ls, "recover_waiters_post aborted");
5274 error = -EINTR;
5275 break;
5276 }
5277
5278 lkb = find_resend_waiter(ls);
5279 if (!lkb)
5280 break;
5281
5282 r = lkb->lkb_resource;
5283 hold_rsb(r);
5284 lock_rsb(r);
5285
5286 mstype = lkb->lkb_wait_type;
5287 oc = is_overlap_cancel(lkb);
5288 ou = is_overlap_unlock(lkb);
5289 err = 0;
5290
5291 log_debug(ls, "waiter %x remote %x msg %d r_nodeid %d "
5292 "lkb_nodeid %d wait_nodeid %d dir_nodeid %d "
5293 "overlap %d %d", lkb->lkb_id, lkb->lkb_remid, mstype,
5294 r->res_nodeid, lkb->lkb_nodeid, lkb->lkb_wait_nodeid,
5295 dlm_dir_nodeid(r), oc, ou);
5296
5297 /* At this point we assume that we won't get a reply to any
5298 previous op or overlap op on this lock. First, do a big
5299 remove_from_waiters() for all previous ops. */
5300
5301 lkb->lkb_flags &= ~DLM_IFL_RESEND;
5302 lkb->lkb_flags &= ~DLM_IFL_OVERLAP_UNLOCK;
5303 lkb->lkb_flags &= ~DLM_IFL_OVERLAP_CANCEL;
5304 lkb->lkb_wait_type = 0;
5305 lkb->lkb_wait_count = 0;
5306 mutex_lock(&ls->ls_waiters_mutex);
5307 list_del_init(&lkb->lkb_wait_reply);
5308 mutex_unlock(&ls->ls_waiters_mutex);
5309 unhold_lkb(lkb); /* for waiters list */
5310
5311 if (oc || ou) {
5312 /* do an unlock or cancel instead of resending */
5313 switch (mstype) {
5314 case DLM_MSG_LOOKUP:
5315 case DLM_MSG_REQUEST:
5316 queue_cast(r, lkb, ou ? -DLM_EUNLOCK :
5317 -DLM_ECANCEL);
5318 unhold_lkb(lkb); /* undoes create_lkb() */
5319 break;
5320 case DLM_MSG_CONVERT:
5321 if (oc) {
5322 queue_cast(r, lkb, -DLM_ECANCEL);
5323 } else {
5324 lkb->lkb_exflags |= DLM_LKF_FORCEUNLOCK;
5325 _unlock_lock(r, lkb);
5326 }
5327 break;
5328 default:
5329 err = 1;
5330 }
5331 } else {
5332 switch (mstype) {
5333 case DLM_MSG_LOOKUP:
5334 case DLM_MSG_REQUEST:
5335 _request_lock(r, lkb);
5336 if (is_master(r))
5337 confirm_master(r, 0);
5338 break;
5339 case DLM_MSG_CONVERT:
5340 _convert_lock(r, lkb);
5341 break;
5342 default:
5343 err = 1;
5344 }
5345 }
5346
5347 if (err) {
5348 log_error(ls, "waiter %x msg %d r_nodeid %d "
5349 "dir_nodeid %d overlap %d %d",
5350 lkb->lkb_id, mstype, r->res_nodeid,
5351 dlm_dir_nodeid(r), oc, ou);
5352 }
5353 unlock_rsb(r);
5354 put_rsb(r);
5355 dlm_put_lkb(lkb);
5356 }
5357
5358 return error;
5359}
5360
5361static void purge_mstcpy_list(struct dlm_ls *ls, struct dlm_rsb *r,
5362 struct list_head *list)
5363{
5364 struct dlm_lkb *lkb, *safe;
5365
5366 list_for_each_entry_safe(lkb, safe, list, lkb_statequeue) {
5367 if (!is_master_copy(lkb))
5368 continue;
5369
5370 /* don't purge lkbs we've added in recover_master_copy for
5371 the current recovery seq */
5372
5373 if (lkb->lkb_recover_seq == ls->ls_recover_seq)
5374 continue;
5375
5376 del_lkb(r, lkb);
5377
5378 /* this put should free the lkb */
5379 if (!dlm_put_lkb(lkb))
5380 log_error(ls, "purged mstcpy lkb not released");
5381 }
5382}
5383
5384void dlm_purge_mstcpy_locks(struct dlm_rsb *r)
5385{
5386 struct dlm_ls *ls = r->res_ls;
5387
5388 purge_mstcpy_list(ls, r, &r->res_grantqueue);
5389 purge_mstcpy_list(ls, r, &r->res_convertqueue);
5390 purge_mstcpy_list(ls, r, &r->res_waitqueue);
5391}
5392
5393static void purge_dead_list(struct dlm_ls *ls, struct dlm_rsb *r,
5394 struct list_head *list,
5395 int nodeid_gone, unsigned int *count)
5396{
5397 struct dlm_lkb *lkb, *safe;
5398
5399 list_for_each_entry_safe(lkb, safe, list, lkb_statequeue) {
5400 if (!is_master_copy(lkb))
5401 continue;
5402
5403 if ((lkb->lkb_nodeid == nodeid_gone) ||
5404 dlm_is_removed(ls, lkb->lkb_nodeid)) {
5405
5406 /* tell recover_lvb to invalidate the lvb
5407 because a node holding EX/PW failed */
5408 if ((lkb->lkb_exflags & DLM_LKF_VALBLK) &&
5409 (lkb->lkb_grmode >= DLM_LOCK_PW)) {
5410 rsb_set_flag(r, RSB_RECOVER_LVB_INVAL);
5411 }
5412
5413 del_lkb(r, lkb);
5414
5415 /* this put should free the lkb */
5416 if (!dlm_put_lkb(lkb))
5417 log_error(ls, "purged dead lkb not released");
5418
5419 rsb_set_flag(r, RSB_RECOVER_GRANT);
5420
5421 (*count)++;
5422 }
5423 }
5424}
5425
5426/* Get rid of locks held by nodes that are gone. */
5427
5428void dlm_recover_purge(struct dlm_ls *ls)
5429{
5430 struct dlm_rsb *r;
5431 struct dlm_member *memb;
5432 int nodes_count = 0;
5433 int nodeid_gone = 0;
5434 unsigned int lkb_count = 0;
5435
5436 /* cache one removed nodeid to optimize the common
5437 case of a single node removed */
5438
5439 list_for_each_entry(memb, &ls->ls_nodes_gone, list) {
5440 nodes_count++;
5441 nodeid_gone = memb->nodeid;
5442 }
5443
5444 if (!nodes_count)
5445 return;
5446
5447 down_write(&ls->ls_root_sem);
5448 list_for_each_entry(r, &ls->ls_root_list, res_root_list) {
5449 hold_rsb(r);
5450 lock_rsb(r);
5451 if (is_master(r)) {
5452 purge_dead_list(ls, r, &r->res_grantqueue,
5453 nodeid_gone, &lkb_count);
5454 purge_dead_list(ls, r, &r->res_convertqueue,
5455 nodeid_gone, &lkb_count);
5456 purge_dead_list(ls, r, &r->res_waitqueue,
5457 nodeid_gone, &lkb_count);
5458 }
5459 unlock_rsb(r);
5460 unhold_rsb(r);
5461 cond_resched();
5462 }
5463 up_write(&ls->ls_root_sem);
5464
5465 if (lkb_count)
5466 log_rinfo(ls, "dlm_recover_purge %u locks for %u nodes",
5467 lkb_count, nodes_count);
5468}
5469
5470static struct dlm_rsb *find_grant_rsb(struct dlm_ls *ls, int bucket)
5471{
5472 struct rb_node *n;
5473 struct dlm_rsb *r;
5474
5475 spin_lock(&ls->ls_rsbtbl[bucket].lock);
5476 for (n = rb_first(&ls->ls_rsbtbl[bucket].keep); n; n = rb_next(n)) {
5477 r = rb_entry(n, struct dlm_rsb, res_hashnode);
5478
5479 if (!rsb_flag(r, RSB_RECOVER_GRANT))
5480 continue;
5481 if (!is_master(r)) {
5482 rsb_clear_flag(r, RSB_RECOVER_GRANT);
5483 continue;
5484 }
5485 hold_rsb(r);
5486 spin_unlock(&ls->ls_rsbtbl[bucket].lock);
5487 return r;
5488 }
5489 spin_unlock(&ls->ls_rsbtbl[bucket].lock);
5490 return NULL;
5491}
5492
5493/*
5494 * Attempt to grant locks on resources that we are the master of.
5495 * Locks may have become grantable during recovery because locks
5496 * from departed nodes have been purged (or not rebuilt), allowing
5497 * previously blocked locks to now be granted. The subset of rsb's
5498 * we are interested in are those with lkb's on either the convert or
5499 * waiting queues.
5500 *
5501 * Simplest would be to go through each master rsb and check for non-empty
5502 * convert or waiting queues, and attempt to grant on those rsbs.
5503 * Checking the queues requires lock_rsb, though, for which we'd need
5504 * to release the rsbtbl lock. This would make iterating through all
5505 * rsb's very inefficient. So, we rely on earlier recovery routines
5506 * to set RECOVER_GRANT on any rsb's that we should attempt to grant
5507 * locks for.
5508 */
5509
5510void dlm_recover_grant(struct dlm_ls *ls)
5511{
5512 struct dlm_rsb *r;
5513 int bucket = 0;
5514 unsigned int count = 0;
5515 unsigned int rsb_count = 0;
5516 unsigned int lkb_count = 0;
5517
5518 while (1) {
5519 r = find_grant_rsb(ls, bucket);
5520 if (!r) {
5521 if (bucket == ls->ls_rsbtbl_size - 1)
5522 break;
5523 bucket++;
5524 continue;
5525 }
5526 rsb_count++;
5527 count = 0;
5528 lock_rsb(r);
5529 /* the RECOVER_GRANT flag is checked in the grant path */
5530 grant_pending_locks(r, &count);
5531 rsb_clear_flag(r, RSB_RECOVER_GRANT);
5532 lkb_count += count;
5533 confirm_master(r, 0);
5534 unlock_rsb(r);
5535 put_rsb(r);
5536 cond_resched();
5537 }
5538
5539 if (lkb_count)
5540 log_rinfo(ls, "dlm_recover_grant %u locks on %u resources",
5541 lkb_count, rsb_count);
5542}
5543
5544static struct dlm_lkb *search_remid_list(struct list_head *head, int nodeid,
5545 uint32_t remid)
5546{
5547 struct dlm_lkb *lkb;
5548
5549 list_for_each_entry(lkb, head, lkb_statequeue) {
5550 if (lkb->lkb_nodeid == nodeid && lkb->lkb_remid == remid)
5551 return lkb;
5552 }
5553 return NULL;
5554}
5555
5556static struct dlm_lkb *search_remid(struct dlm_rsb *r, int nodeid,
5557 uint32_t remid)
5558{
5559 struct dlm_lkb *lkb;
5560
5561 lkb = search_remid_list(&r->res_grantqueue, nodeid, remid);
5562 if (lkb)
5563 return lkb;
5564 lkb = search_remid_list(&r->res_convertqueue, nodeid, remid);
5565 if (lkb)
5566 return lkb;
5567 lkb = search_remid_list(&r->res_waitqueue, nodeid, remid);
5568 if (lkb)
5569 return lkb;
5570 return NULL;
5571}
5572
5573/* needs at least dlm_rcom + rcom_lock */
5574static int receive_rcom_lock_args(struct dlm_ls *ls, struct dlm_lkb *lkb,
5575 struct dlm_rsb *r, struct dlm_rcom *rc)
5576{
5577 struct rcom_lock *rl = (struct rcom_lock *) rc->rc_buf;
5578
5579 lkb->lkb_nodeid = rc->rc_header.h_nodeid;
5580 lkb->lkb_ownpid = le32_to_cpu(rl->rl_ownpid);
5581 lkb->lkb_remid = le32_to_cpu(rl->rl_lkid);
5582 lkb->lkb_exflags = le32_to_cpu(rl->rl_exflags);
5583 lkb->lkb_flags = le32_to_cpu(rl->rl_flags) & 0x0000FFFF;
5584 lkb->lkb_flags |= DLM_IFL_MSTCPY;
5585 lkb->lkb_lvbseq = le32_to_cpu(rl->rl_lvbseq);
5586 lkb->lkb_rqmode = rl->rl_rqmode;
5587 lkb->lkb_grmode = rl->rl_grmode;
5588 /* don't set lkb_status because add_lkb wants to itself */
5589
5590 lkb->lkb_bastfn = (rl->rl_asts & DLM_CB_BAST) ? &fake_bastfn : NULL;
5591 lkb->lkb_astfn = (rl->rl_asts & DLM_CB_CAST) ? &fake_astfn : NULL;
5592
5593 if (lkb->lkb_exflags & DLM_LKF_VALBLK) {
5594 int lvblen = rc->rc_header.h_length - sizeof(struct dlm_rcom) -
5595 sizeof(struct rcom_lock);
5596 if (lvblen > ls->ls_lvblen)
5597 return -EINVAL;
5598 lkb->lkb_lvbptr = dlm_allocate_lvb(ls);
5599 if (!lkb->lkb_lvbptr)
5600 return -ENOMEM;
5601 memcpy(lkb->lkb_lvbptr, rl->rl_lvb, lvblen);
5602 }
5603
5604 /* Conversions between PR and CW (middle modes) need special handling.
5605 The real granted mode of these converting locks cannot be determined
5606 until all locks have been rebuilt on the rsb (recover_conversion) */
5607
5608 if (rl->rl_wait_type == cpu_to_le16(DLM_MSG_CONVERT) &&
5609 middle_conversion(lkb)) {
5610 rl->rl_status = DLM_LKSTS_CONVERT;
5611 lkb->lkb_grmode = DLM_LOCK_IV;
5612 rsb_set_flag(r, RSB_RECOVER_CONVERT);
5613 }
5614
5615 return 0;
5616}
5617
5618/* This lkb may have been recovered in a previous aborted recovery so we need
5619 to check if the rsb already has an lkb with the given remote nodeid/lkid.
5620 If so we just send back a standard reply. If not, we create a new lkb with
5621 the given values and send back our lkid. We send back our lkid by sending
5622 back the rcom_lock struct we got but with the remid field filled in. */
5623
5624/* needs at least dlm_rcom + rcom_lock */
5625int dlm_recover_master_copy(struct dlm_ls *ls, struct dlm_rcom *rc)
5626{
5627 struct rcom_lock *rl = (struct rcom_lock *) rc->rc_buf;
5628 struct dlm_rsb *r;
5629 struct dlm_lkb *lkb;
5630 uint32_t remid = 0;
5631 int from_nodeid = rc->rc_header.h_nodeid;
5632 int error;
5633
5634 if (rl->rl_parent_lkid) {
5635 error = -EOPNOTSUPP;
5636 goto out;
5637 }
5638
5639 remid = le32_to_cpu(rl->rl_lkid);
5640
5641 /* In general we expect the rsb returned to be R_MASTER, but we don't
5642 have to require it. Recovery of masters on one node can overlap
5643 recovery of locks on another node, so one node can send us MSTCPY
5644 locks before we've made ourselves master of this rsb. We can still
5645 add new MSTCPY locks that we receive here without any harm; when
5646 we make ourselves master, dlm_recover_masters() won't touch the
5647 MSTCPY locks we've received early. */
5648
5649 error = find_rsb(ls, rl->rl_name, le16_to_cpu(rl->rl_namelen),
5650 from_nodeid, R_RECEIVE_RECOVER, &r);
5651 if (error)
5652 goto out;
5653
5654 lock_rsb(r);
5655
5656 if (dlm_no_directory(ls) && (dlm_dir_nodeid(r) != dlm_our_nodeid())) {
5657 log_error(ls, "dlm_recover_master_copy remote %d %x not dir",
5658 from_nodeid, remid);
5659 error = -EBADR;
5660 goto out_unlock;
5661 }
5662
5663 lkb = search_remid(r, from_nodeid, remid);
5664 if (lkb) {
5665 error = -EEXIST;
5666 goto out_remid;
5667 }
5668
5669 error = create_lkb(ls, &lkb);
5670 if (error)
5671 goto out_unlock;
5672
5673 error = receive_rcom_lock_args(ls, lkb, r, rc);
5674 if (error) {
5675 __put_lkb(ls, lkb);
5676 goto out_unlock;
5677 }
5678
5679 attach_lkb(r, lkb);
5680 add_lkb(r, lkb, rl->rl_status);
5681 error = 0;
5682 ls->ls_recover_locks_in++;
5683
5684 if (!list_empty(&r->res_waitqueue) || !list_empty(&r->res_convertqueue))
5685 rsb_set_flag(r, RSB_RECOVER_GRANT);
5686
5687 out_remid:
5688 /* this is the new value returned to the lock holder for
5689 saving in its process-copy lkb */
5690 rl->rl_remid = cpu_to_le32(lkb->lkb_id);
5691
5692 lkb->lkb_recover_seq = ls->ls_recover_seq;
5693
5694 out_unlock:
5695 unlock_rsb(r);
5696 put_rsb(r);
5697 out:
5698 if (error && error != -EEXIST)
5699 log_rinfo(ls, "dlm_recover_master_copy remote %d %x error %d",
5700 from_nodeid, remid, error);
5701 rl->rl_result = cpu_to_le32(error);
5702 return error;
5703}
5704
5705/* needs at least dlm_rcom + rcom_lock */
5706int dlm_recover_process_copy(struct dlm_ls *ls, struct dlm_rcom *rc)
5707{
5708 struct rcom_lock *rl = (struct rcom_lock *) rc->rc_buf;
5709 struct dlm_rsb *r;
5710 struct dlm_lkb *lkb;
5711 uint32_t lkid, remid;
5712 int error, result;
5713
5714 lkid = le32_to_cpu(rl->rl_lkid);
5715 remid = le32_to_cpu(rl->rl_remid);
5716 result = le32_to_cpu(rl->rl_result);
5717
5718 error = find_lkb(ls, lkid, &lkb);
5719 if (error) {
5720 log_error(ls, "dlm_recover_process_copy no %x remote %d %x %d",
5721 lkid, rc->rc_header.h_nodeid, remid, result);
5722 return error;
5723 }
5724
5725 r = lkb->lkb_resource;
5726 hold_rsb(r);
5727 lock_rsb(r);
5728
5729 if (!is_process_copy(lkb)) {
5730 log_error(ls, "dlm_recover_process_copy bad %x remote %d %x %d",
5731 lkid, rc->rc_header.h_nodeid, remid, result);
5732 dlm_dump_rsb(r);
5733 unlock_rsb(r);
5734 put_rsb(r);
5735 dlm_put_lkb(lkb);
5736 return -EINVAL;
5737 }
5738
5739 switch (result) {
5740 case -EBADR:
5741 /* There's a chance the new master received our lock before
5742 dlm_recover_master_reply(), this wouldn't happen if we did
5743 a barrier between recover_masters and recover_locks. */
5744
5745 log_debug(ls, "dlm_recover_process_copy %x remote %d %x %d",
5746 lkid, rc->rc_header.h_nodeid, remid, result);
5747
5748 dlm_send_rcom_lock(r, lkb);
5749 goto out;
5750 case -EEXIST:
5751 case 0:
5752 lkb->lkb_remid = remid;
5753 break;
5754 default:
5755 log_error(ls, "dlm_recover_process_copy %x remote %d %x %d unk",
5756 lkid, rc->rc_header.h_nodeid, remid, result);
5757 }
5758
5759 /* an ack for dlm_recover_locks() which waits for replies from
5760 all the locks it sends to new masters */
5761 dlm_recovered_lock(r);
5762 out:
5763 unlock_rsb(r);
5764 put_rsb(r);
5765 dlm_put_lkb(lkb);
5766
5767 return 0;
5768}
5769
5770int dlm_user_request(struct dlm_ls *ls, struct dlm_user_args *ua,
5771 int mode, uint32_t flags, void *name, unsigned int namelen,
5772 unsigned long timeout_cs)
5773{
5774 struct dlm_lkb *lkb;
5775 struct dlm_args args;
5776 int error;
5777
5778 dlm_lock_recovery(ls);
5779
5780 error = create_lkb(ls, &lkb);
5781 if (error) {
5782 kfree(ua);
5783 goto out;
5784 }
5785
5786 if (flags & DLM_LKF_VALBLK) {
5787 ua->lksb.sb_lvbptr = kzalloc(DLM_USER_LVB_LEN, GFP_NOFS);
5788 if (!ua->lksb.sb_lvbptr) {
5789 kfree(ua);
5790 __put_lkb(ls, lkb);
5791 error = -ENOMEM;
5792 goto out;
5793 }
5794 }
5795
5796 /* After ua is attached to lkb it will be freed by dlm_free_lkb().
5797 When DLM_IFL_USER is set, the dlm knows that this is a userspace
5798 lock and that lkb_astparam is the dlm_user_args structure. */
5799
5800 error = set_lock_args(mode, &ua->lksb, flags, namelen, timeout_cs,
5801 fake_astfn, ua, fake_bastfn, &args);
5802 lkb->lkb_flags |= DLM_IFL_USER;
5803
5804 if (error) {
5805 __put_lkb(ls, lkb);
5806 goto out;
5807 }
5808
5809 error = request_lock(ls, lkb, name, namelen, &args);
5810
5811 switch (error) {
5812 case 0:
5813 break;
5814 case -EINPROGRESS:
5815 error = 0;
5816 break;
5817 case -EAGAIN:
5818 error = 0;
5819 /* fall through */
5820 default:
5821 __put_lkb(ls, lkb);
5822 goto out;
5823 }
5824
5825 /* add this new lkb to the per-process list of locks */
5826 spin_lock(&ua->proc->locks_spin);
5827 hold_lkb(lkb);
5828 list_add_tail(&lkb->lkb_ownqueue, &ua->proc->locks);
5829 spin_unlock(&ua->proc->locks_spin);
5830 out:
5831 dlm_unlock_recovery(ls);
5832 return error;
5833}
5834
5835int dlm_user_convert(struct dlm_ls *ls, struct dlm_user_args *ua_tmp,
5836 int mode, uint32_t flags, uint32_t lkid, char *lvb_in,
5837 unsigned long timeout_cs)
5838{
5839 struct dlm_lkb *lkb;
5840 struct dlm_args args;
5841 struct dlm_user_args *ua;
5842 int error;
5843
5844 dlm_lock_recovery(ls);
5845
5846 error = find_lkb(ls, lkid, &lkb);
5847 if (error)
5848 goto out;
5849
5850 /* user can change the params on its lock when it converts it, or
5851 add an lvb that didn't exist before */
5852
5853 ua = lkb->lkb_ua;
5854
5855 if (flags & DLM_LKF_VALBLK && !ua->lksb.sb_lvbptr) {
5856 ua->lksb.sb_lvbptr = kzalloc(DLM_USER_LVB_LEN, GFP_NOFS);
5857 if (!ua->lksb.sb_lvbptr) {
5858 error = -ENOMEM;
5859 goto out_put;
5860 }
5861 }
5862 if (lvb_in && ua->lksb.sb_lvbptr)
5863 memcpy(ua->lksb.sb_lvbptr, lvb_in, DLM_USER_LVB_LEN);
5864
5865 ua->xid = ua_tmp->xid;
5866 ua->castparam = ua_tmp->castparam;
5867 ua->castaddr = ua_tmp->castaddr;
5868 ua->bastparam = ua_tmp->bastparam;
5869 ua->bastaddr = ua_tmp->bastaddr;
5870 ua->user_lksb = ua_tmp->user_lksb;
5871
5872 error = set_lock_args(mode, &ua->lksb, flags, 0, timeout_cs,
5873 fake_astfn, ua, fake_bastfn, &args);
5874 if (error)
5875 goto out_put;
5876
5877 error = convert_lock(ls, lkb, &args);
5878
5879 if (error == -EINPROGRESS || error == -EAGAIN || error == -EDEADLK)
5880 error = 0;
5881 out_put:
5882 dlm_put_lkb(lkb);
5883 out:
5884 dlm_unlock_recovery(ls);
5885 kfree(ua_tmp);
5886 return error;
5887}
5888
5889/*
5890 * The caller asks for an orphan lock on a given resource with a given mode.
5891 * If a matching lock exists, it's moved to the owner's list of locks and
5892 * the lkid is returned.
5893 */
5894
5895int dlm_user_adopt_orphan(struct dlm_ls *ls, struct dlm_user_args *ua_tmp,
5896 int mode, uint32_t flags, void *name, unsigned int namelen,
5897 unsigned long timeout_cs, uint32_t *lkid)
5898{
5899 struct dlm_lkb *lkb;
5900 struct dlm_user_args *ua;
5901 int found_other_mode = 0;
5902 int found = 0;
5903 int rv = 0;
5904
5905 mutex_lock(&ls->ls_orphans_mutex);
5906 list_for_each_entry(lkb, &ls->ls_orphans, lkb_ownqueue) {
5907 if (lkb->lkb_resource->res_length != namelen)
5908 continue;
5909 if (memcmp(lkb->lkb_resource->res_name, name, namelen))
5910 continue;
5911 if (lkb->lkb_grmode != mode) {
5912 found_other_mode = 1;
5913 continue;
5914 }
5915
5916 found = 1;
5917 list_del_init(&lkb->lkb_ownqueue);
5918 lkb->lkb_flags &= ~DLM_IFL_ORPHAN;
5919 *lkid = lkb->lkb_id;
5920 break;
5921 }
5922 mutex_unlock(&ls->ls_orphans_mutex);
5923
5924 if (!found && found_other_mode) {
5925 rv = -EAGAIN;
5926 goto out;
5927 }
5928
5929 if (!found) {
5930 rv = -ENOENT;
5931 goto out;
5932 }
5933
5934 lkb->lkb_exflags = flags;
5935 lkb->lkb_ownpid = (int) current->pid;
5936
5937 ua = lkb->lkb_ua;
5938
5939 ua->proc = ua_tmp->proc;
5940 ua->xid = ua_tmp->xid;
5941 ua->castparam = ua_tmp->castparam;
5942 ua->castaddr = ua_tmp->castaddr;
5943 ua->bastparam = ua_tmp->bastparam;
5944 ua->bastaddr = ua_tmp->bastaddr;
5945 ua->user_lksb = ua_tmp->user_lksb;
5946
5947 /*
5948 * The lkb reference from the ls_orphans list was not
5949 * removed above, and is now considered the reference
5950 * for the proc locks list.
5951 */
5952
5953 spin_lock(&ua->proc->locks_spin);
5954 list_add_tail(&lkb->lkb_ownqueue, &ua->proc->locks);
5955 spin_unlock(&ua->proc->locks_spin);
5956 out:
5957 kfree(ua_tmp);
5958 return rv;
5959}
5960
5961int dlm_user_unlock(struct dlm_ls *ls, struct dlm_user_args *ua_tmp,
5962 uint32_t flags, uint32_t lkid, char *lvb_in)
5963{
5964 struct dlm_lkb *lkb;
5965 struct dlm_args args;
5966 struct dlm_user_args *ua;
5967 int error;
5968
5969 dlm_lock_recovery(ls);
5970
5971 error = find_lkb(ls, lkid, &lkb);
5972 if (error)
5973 goto out;
5974
5975 ua = lkb->lkb_ua;
5976
5977 if (lvb_in && ua->lksb.sb_lvbptr)
5978 memcpy(ua->lksb.sb_lvbptr, lvb_in, DLM_USER_LVB_LEN);
5979 if (ua_tmp->castparam)
5980 ua->castparam = ua_tmp->castparam;
5981 ua->user_lksb = ua_tmp->user_lksb;
5982
5983 error = set_unlock_args(flags, ua, &args);
5984 if (error)
5985 goto out_put;
5986
5987 error = unlock_lock(ls, lkb, &args);
5988
5989 if (error == -DLM_EUNLOCK)
5990 error = 0;
5991 /* from validate_unlock_args() */
5992 if (error == -EBUSY && (flags & DLM_LKF_FORCEUNLOCK))
5993 error = 0;
5994 if (error)
5995 goto out_put;
5996
5997 spin_lock(&ua->proc->locks_spin);
5998 /* dlm_user_add_cb() may have already taken lkb off the proc list */
5999 if (!list_empty(&lkb->lkb_ownqueue))
6000 list_move(&lkb->lkb_ownqueue, &ua->proc->unlocking);
6001 spin_unlock(&ua->proc->locks_spin);
6002 out_put:
6003 dlm_put_lkb(lkb);
6004 out:
6005 dlm_unlock_recovery(ls);
6006 kfree(ua_tmp);
6007 return error;
6008}
6009
6010int dlm_user_cancel(struct dlm_ls *ls, struct dlm_user_args *ua_tmp,
6011 uint32_t flags, uint32_t lkid)
6012{
6013 struct dlm_lkb *lkb;
6014 struct dlm_args args;
6015 struct dlm_user_args *ua;
6016 int error;
6017
6018 dlm_lock_recovery(ls);
6019
6020 error = find_lkb(ls, lkid, &lkb);
6021 if (error)
6022 goto out;
6023
6024 ua = lkb->lkb_ua;
6025 if (ua_tmp->castparam)
6026 ua->castparam = ua_tmp->castparam;
6027 ua->user_lksb = ua_tmp->user_lksb;
6028
6029 error = set_unlock_args(flags, ua, &args);
6030 if (error)
6031 goto out_put;
6032
6033 error = cancel_lock(ls, lkb, &args);
6034
6035 if (error == -DLM_ECANCEL)
6036 error = 0;
6037 /* from validate_unlock_args() */
6038 if (error == -EBUSY)
6039 error = 0;
6040 out_put:
6041 dlm_put_lkb(lkb);
6042 out:
6043 dlm_unlock_recovery(ls);
6044 kfree(ua_tmp);
6045 return error;
6046}
6047
6048int dlm_user_deadlock(struct dlm_ls *ls, uint32_t flags, uint32_t lkid)
6049{
6050 struct dlm_lkb *lkb;
6051 struct dlm_args args;
6052 struct dlm_user_args *ua;
6053 struct dlm_rsb *r;
6054 int error;
6055
6056 dlm_lock_recovery(ls);
6057
6058 error = find_lkb(ls, lkid, &lkb);
6059 if (error)
6060 goto out;
6061
6062 ua = lkb->lkb_ua;
6063
6064 error = set_unlock_args(flags, ua, &args);
6065 if (error)
6066 goto out_put;
6067
6068 /* same as cancel_lock(), but set DEADLOCK_CANCEL after lock_rsb */
6069
6070 r = lkb->lkb_resource;
6071 hold_rsb(r);
6072 lock_rsb(r);
6073
6074 error = validate_unlock_args(lkb, &args);
6075 if (error)
6076 goto out_r;
6077 lkb->lkb_flags |= DLM_IFL_DEADLOCK_CANCEL;
6078
6079 error = _cancel_lock(r, lkb);
6080 out_r:
6081 unlock_rsb(r);
6082 put_rsb(r);
6083
6084 if (error == -DLM_ECANCEL)
6085 error = 0;
6086 /* from validate_unlock_args() */
6087 if (error == -EBUSY)
6088 error = 0;
6089 out_put:
6090 dlm_put_lkb(lkb);
6091 out:
6092 dlm_unlock_recovery(ls);
6093 return error;
6094}
6095
6096/* lkb's that are removed from the waiters list by revert are just left on the
6097 orphans list with the granted orphan locks, to be freed by purge */
6098
6099static int orphan_proc_lock(struct dlm_ls *ls, struct dlm_lkb *lkb)
6100{
6101 struct dlm_args args;
6102 int error;
6103
6104 hold_lkb(lkb); /* reference for the ls_orphans list */
6105 mutex_lock(&ls->ls_orphans_mutex);
6106 list_add_tail(&lkb->lkb_ownqueue, &ls->ls_orphans);
6107 mutex_unlock(&ls->ls_orphans_mutex);
6108
6109 set_unlock_args(0, lkb->lkb_ua, &args);
6110
6111 error = cancel_lock(ls, lkb, &args);
6112 if (error == -DLM_ECANCEL)
6113 error = 0;
6114 return error;
6115}
6116
6117/* The FORCEUNLOCK flag allows the unlock to go ahead even if the lkb isn't
6118 granted. Regardless of what rsb queue the lock is on, it's removed and
6119 freed. The IVVALBLK flag causes the lvb on the resource to be invalidated
6120 if our lock is PW/EX (it's ignored if our granted mode is smaller.) */
6121
6122static int unlock_proc_lock(struct dlm_ls *ls, struct dlm_lkb *lkb)
6123{
6124 struct dlm_args args;
6125 int error;
6126
6127 set_unlock_args(DLM_LKF_FORCEUNLOCK | DLM_LKF_IVVALBLK,
6128 lkb->lkb_ua, &args);
6129
6130 error = unlock_lock(ls, lkb, &args);
6131 if (error == -DLM_EUNLOCK)
6132 error = 0;
6133 return error;
6134}
6135
6136/* We have to release clear_proc_locks mutex before calling unlock_proc_lock()
6137 (which does lock_rsb) due to deadlock with receiving a message that does
6138 lock_rsb followed by dlm_user_add_cb() */
6139
6140static struct dlm_lkb *del_proc_lock(struct dlm_ls *ls,
6141 struct dlm_user_proc *proc)
6142{
6143 struct dlm_lkb *lkb = NULL;
6144
6145 mutex_lock(&ls->ls_clear_proc_locks);
6146 if (list_empty(&proc->locks))
6147 goto out;
6148
6149 lkb = list_entry(proc->locks.next, struct dlm_lkb, lkb_ownqueue);
6150 list_del_init(&lkb->lkb_ownqueue);
6151
6152 if (lkb->lkb_exflags & DLM_LKF_PERSISTENT)
6153 lkb->lkb_flags |= DLM_IFL_ORPHAN;
6154 else
6155 lkb->lkb_flags |= DLM_IFL_DEAD;
6156 out:
6157 mutex_unlock(&ls->ls_clear_proc_locks);
6158 return lkb;
6159}
6160
6161/* The ls_clear_proc_locks mutex protects against dlm_user_add_cb() which
6162 1) references lkb->ua which we free here and 2) adds lkbs to proc->asts,
6163 which we clear here. */
6164
6165/* proc CLOSING flag is set so no more device_reads should look at proc->asts
6166 list, and no more device_writes should add lkb's to proc->locks list; so we
6167 shouldn't need to take asts_spin or locks_spin here. this assumes that
6168 device reads/writes/closes are serialized -- FIXME: we may need to serialize
6169 them ourself. */
6170
6171void dlm_clear_proc_locks(struct dlm_ls *ls, struct dlm_user_proc *proc)
6172{
6173 struct dlm_lkb *lkb, *safe;
6174
6175 dlm_lock_recovery(ls);
6176
6177 while (1) {
6178 lkb = del_proc_lock(ls, proc);
6179 if (!lkb)
6180 break;
6181 del_timeout(lkb);
6182 if (lkb->lkb_exflags & DLM_LKF_PERSISTENT)
6183 orphan_proc_lock(ls, lkb);
6184 else
6185 unlock_proc_lock(ls, lkb);
6186
6187 /* this removes the reference for the proc->locks list
6188 added by dlm_user_request, it may result in the lkb
6189 being freed */
6190
6191 dlm_put_lkb(lkb);
6192 }
6193
6194 mutex_lock(&ls->ls_clear_proc_locks);
6195
6196 /* in-progress unlocks */
6197 list_for_each_entry_safe(lkb, safe, &proc->unlocking, lkb_ownqueue) {
6198 list_del_init(&lkb->lkb_ownqueue);
6199 lkb->lkb_flags |= DLM_IFL_DEAD;
6200 dlm_put_lkb(lkb);
6201 }
6202
6203 list_for_each_entry_safe(lkb, safe, &proc->asts, lkb_cb_list) {
6204 memset(&lkb->lkb_callbacks, 0,
6205 sizeof(struct dlm_callback) * DLM_CALLBACKS_SIZE);
6206 list_del_init(&lkb->lkb_cb_list);
6207 dlm_put_lkb(lkb);
6208 }
6209
6210 mutex_unlock(&ls->ls_clear_proc_locks);
6211 dlm_unlock_recovery(ls);
6212}
6213
6214static void purge_proc_locks(struct dlm_ls *ls, struct dlm_user_proc *proc)
6215{
6216 struct dlm_lkb *lkb, *safe;
6217
6218 while (1) {
6219 lkb = NULL;
6220 spin_lock(&proc->locks_spin);
6221 if (!list_empty(&proc->locks)) {
6222 lkb = list_entry(proc->locks.next, struct dlm_lkb,
6223 lkb_ownqueue);
6224 list_del_init(&lkb->lkb_ownqueue);
6225 }
6226 spin_unlock(&proc->locks_spin);
6227
6228 if (!lkb)
6229 break;
6230
6231 lkb->lkb_flags |= DLM_IFL_DEAD;
6232 unlock_proc_lock(ls, lkb);
6233 dlm_put_lkb(lkb); /* ref from proc->locks list */
6234 }
6235
6236 spin_lock(&proc->locks_spin);
6237 list_for_each_entry_safe(lkb, safe, &proc->unlocking, lkb_ownqueue) {
6238 list_del_init(&lkb->lkb_ownqueue);
6239 lkb->lkb_flags |= DLM_IFL_DEAD;
6240 dlm_put_lkb(lkb);
6241 }
6242 spin_unlock(&proc->locks_spin);
6243
6244 spin_lock(&proc->asts_spin);
6245 list_for_each_entry_safe(lkb, safe, &proc->asts, lkb_cb_list) {
6246 memset(&lkb->lkb_callbacks, 0,
6247 sizeof(struct dlm_callback) * DLM_CALLBACKS_SIZE);
6248 list_del_init(&lkb->lkb_cb_list);
6249 dlm_put_lkb(lkb);
6250 }
6251 spin_unlock(&proc->asts_spin);
6252}
6253
6254/* pid of 0 means purge all orphans */
6255
6256static void do_purge(struct dlm_ls *ls, int nodeid, int pid)
6257{
6258 struct dlm_lkb *lkb, *safe;
6259
6260 mutex_lock(&ls->ls_orphans_mutex);
6261 list_for_each_entry_safe(lkb, safe, &ls->ls_orphans, lkb_ownqueue) {
6262 if (pid && lkb->lkb_ownpid != pid)
6263 continue;
6264 unlock_proc_lock(ls, lkb);
6265 list_del_init(&lkb->lkb_ownqueue);
6266 dlm_put_lkb(lkb);
6267 }
6268 mutex_unlock(&ls->ls_orphans_mutex);
6269}
6270
6271static int send_purge(struct dlm_ls *ls, int nodeid, int pid)
6272{
6273 struct dlm_message *ms;
6274 struct dlm_mhandle *mh;
6275 int error;
6276
6277 error = _create_message(ls, sizeof(struct dlm_message), nodeid,
6278 DLM_MSG_PURGE, &ms, &mh);
6279 if (error)
6280 return error;
6281 ms->m_nodeid = nodeid;
6282 ms->m_pid = pid;
6283
6284 return send_message(mh, ms);
6285}
6286
6287int dlm_user_purge(struct dlm_ls *ls, struct dlm_user_proc *proc,
6288 int nodeid, int pid)
6289{
6290 int error = 0;
6291
6292 if (nodeid && (nodeid != dlm_our_nodeid())) {
6293 error = send_purge(ls, nodeid, pid);
6294 } else {
6295 dlm_lock_recovery(ls);
6296 if (pid == current->pid)
6297 purge_proc_locks(ls, proc);
6298 else
6299 do_purge(ls, nodeid, pid);
6300 dlm_unlock_recovery(ls);
6301 }
6302 return error;
6303}
6304
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/slab.h>
60#include "dlm_internal.h"
61#include <linux/dlm_device.h>
62#include "memory.h"
63#include "lowcomms.h"
64#include "requestqueue.h"
65#include "util.h"
66#include "dir.h"
67#include "member.h"
68#include "lockspace.h"
69#include "ast.h"
70#include "lock.h"
71#include "rcom.h"
72#include "recover.h"
73#include "lvb_table.h"
74#include "user.h"
75#include "config.h"
76
77static int send_request(struct dlm_rsb *r, struct dlm_lkb *lkb);
78static int send_convert(struct dlm_rsb *r, struct dlm_lkb *lkb);
79static int send_unlock(struct dlm_rsb *r, struct dlm_lkb *lkb);
80static int send_cancel(struct dlm_rsb *r, struct dlm_lkb *lkb);
81static int send_grant(struct dlm_rsb *r, struct dlm_lkb *lkb);
82static int send_bast(struct dlm_rsb *r, struct dlm_lkb *lkb, int mode);
83static int send_lookup(struct dlm_rsb *r, struct dlm_lkb *lkb);
84static int send_remove(struct dlm_rsb *r);
85static int _request_lock(struct dlm_rsb *r, struct dlm_lkb *lkb);
86static int _cancel_lock(struct dlm_rsb *r, struct dlm_lkb *lkb);
87static void __receive_convert_reply(struct dlm_rsb *r, struct dlm_lkb *lkb,
88 struct dlm_message *ms);
89static int receive_extralen(struct dlm_message *ms);
90static void do_purge(struct dlm_ls *ls, int nodeid, int pid);
91static void del_timeout(struct dlm_lkb *lkb);
92
93/*
94 * Lock compatibilty matrix - thanks Steve
95 * UN = Unlocked state. Not really a state, used as a flag
96 * PD = Padding. Used to make the matrix a nice power of two in size
97 * Other states are the same as the VMS DLM.
98 * Usage: matrix[grmode+1][rqmode+1] (although m[rq+1][gr+1] is the same)
99 */
100
101static const int __dlm_compat_matrix[8][8] = {
102 /* UN NL CR CW PR PW EX PD */
103 {1, 1, 1, 1, 1, 1, 1, 0}, /* UN */
104 {1, 1, 1, 1, 1, 1, 1, 0}, /* NL */
105 {1, 1, 1, 1, 1, 1, 0, 0}, /* CR */
106 {1, 1, 1, 1, 0, 0, 0, 0}, /* CW */
107 {1, 1, 1, 0, 1, 0, 0, 0}, /* PR */
108 {1, 1, 1, 0, 0, 0, 0, 0}, /* PW */
109 {1, 1, 0, 0, 0, 0, 0, 0}, /* EX */
110 {0, 0, 0, 0, 0, 0, 0, 0} /* PD */
111};
112
113/*
114 * This defines the direction of transfer of LVB data.
115 * Granted mode is the row; requested mode is the column.
116 * Usage: matrix[grmode+1][rqmode+1]
117 * 1 = LVB is returned to the caller
118 * 0 = LVB is written to the resource
119 * -1 = nothing happens to the LVB
120 */
121
122const int dlm_lvb_operations[8][8] = {
123 /* UN NL CR CW PR PW EX PD*/
124 { -1, 1, 1, 1, 1, 1, 1, -1 }, /* UN */
125 { -1, 1, 1, 1, 1, 1, 1, 0 }, /* NL */
126 { -1, -1, 1, 1, 1, 1, 1, 0 }, /* CR */
127 { -1, -1, -1, 1, 1, 1, 1, 0 }, /* CW */
128 { -1, -1, -1, -1, 1, 1, 1, 0 }, /* PR */
129 { -1, 0, 0, 0, 0, 0, 1, 0 }, /* PW */
130 { -1, 0, 0, 0, 0, 0, 0, 0 }, /* EX */
131 { -1, 0, 0, 0, 0, 0, 0, 0 } /* PD */
132};
133
134#define modes_compat(gr, rq) \
135 __dlm_compat_matrix[(gr)->lkb_grmode + 1][(rq)->lkb_rqmode + 1]
136
137int dlm_modes_compat(int mode1, int mode2)
138{
139 return __dlm_compat_matrix[mode1 + 1][mode2 + 1];
140}
141
142/*
143 * Compatibility matrix for conversions with QUECVT set.
144 * Granted mode is the row; requested mode is the column.
145 * Usage: matrix[grmode+1][rqmode+1]
146 */
147
148static const int __quecvt_compat_matrix[8][8] = {
149 /* UN NL CR CW PR PW EX PD */
150 {0, 0, 0, 0, 0, 0, 0, 0}, /* UN */
151 {0, 0, 1, 1, 1, 1, 1, 0}, /* NL */
152 {0, 0, 0, 1, 1, 1, 1, 0}, /* CR */
153 {0, 0, 0, 0, 1, 1, 1, 0}, /* CW */
154 {0, 0, 0, 1, 0, 1, 1, 0}, /* PR */
155 {0, 0, 0, 0, 0, 0, 1, 0}, /* PW */
156 {0, 0, 0, 0, 0, 0, 0, 0}, /* EX */
157 {0, 0, 0, 0, 0, 0, 0, 0} /* PD */
158};
159
160void dlm_print_lkb(struct dlm_lkb *lkb)
161{
162 printk(KERN_ERR "lkb: nodeid %d id %x remid %x exflags %x flags %x\n"
163 " status %d rqmode %d grmode %d wait_type %d\n",
164 lkb->lkb_nodeid, lkb->lkb_id, lkb->lkb_remid, lkb->lkb_exflags,
165 lkb->lkb_flags, lkb->lkb_status, lkb->lkb_rqmode,
166 lkb->lkb_grmode, lkb->lkb_wait_type);
167}
168
169static void dlm_print_rsb(struct dlm_rsb *r)
170{
171 printk(KERN_ERR "rsb: nodeid %d flags %lx first %x rlc %d name %s\n",
172 r->res_nodeid, r->res_flags, r->res_first_lkid,
173 r->res_recover_locks_count, r->res_name);
174}
175
176void dlm_dump_rsb(struct dlm_rsb *r)
177{
178 struct dlm_lkb *lkb;
179
180 dlm_print_rsb(r);
181
182 printk(KERN_ERR "rsb: root_list empty %d recover_list empty %d\n",
183 list_empty(&r->res_root_list), list_empty(&r->res_recover_list));
184 printk(KERN_ERR "rsb lookup list\n");
185 list_for_each_entry(lkb, &r->res_lookup, lkb_rsb_lookup)
186 dlm_print_lkb(lkb);
187 printk(KERN_ERR "rsb grant queue:\n");
188 list_for_each_entry(lkb, &r->res_grantqueue, lkb_statequeue)
189 dlm_print_lkb(lkb);
190 printk(KERN_ERR "rsb convert queue:\n");
191 list_for_each_entry(lkb, &r->res_convertqueue, lkb_statequeue)
192 dlm_print_lkb(lkb);
193 printk(KERN_ERR "rsb wait queue:\n");
194 list_for_each_entry(lkb, &r->res_waitqueue, lkb_statequeue)
195 dlm_print_lkb(lkb);
196}
197
198/* Threads cannot use the lockspace while it's being recovered */
199
200static inline void dlm_lock_recovery(struct dlm_ls *ls)
201{
202 down_read(&ls->ls_in_recovery);
203}
204
205void dlm_unlock_recovery(struct dlm_ls *ls)
206{
207 up_read(&ls->ls_in_recovery);
208}
209
210int dlm_lock_recovery_try(struct dlm_ls *ls)
211{
212 return down_read_trylock(&ls->ls_in_recovery);
213}
214
215static inline int can_be_queued(struct dlm_lkb *lkb)
216{
217 return !(lkb->lkb_exflags & DLM_LKF_NOQUEUE);
218}
219
220static inline int force_blocking_asts(struct dlm_lkb *lkb)
221{
222 return (lkb->lkb_exflags & DLM_LKF_NOQUEUEBAST);
223}
224
225static inline int is_demoted(struct dlm_lkb *lkb)
226{
227 return (lkb->lkb_sbflags & DLM_SBF_DEMOTED);
228}
229
230static inline int is_altmode(struct dlm_lkb *lkb)
231{
232 return (lkb->lkb_sbflags & DLM_SBF_ALTMODE);
233}
234
235static inline int is_granted(struct dlm_lkb *lkb)
236{
237 return (lkb->lkb_status == DLM_LKSTS_GRANTED);
238}
239
240static inline int is_remote(struct dlm_rsb *r)
241{
242 DLM_ASSERT(r->res_nodeid >= 0, dlm_print_rsb(r););
243 return !!r->res_nodeid;
244}
245
246static inline int is_process_copy(struct dlm_lkb *lkb)
247{
248 return (lkb->lkb_nodeid && !(lkb->lkb_flags & DLM_IFL_MSTCPY));
249}
250
251static inline int is_master_copy(struct dlm_lkb *lkb)
252{
253 if (lkb->lkb_flags & DLM_IFL_MSTCPY)
254 DLM_ASSERT(lkb->lkb_nodeid, dlm_print_lkb(lkb););
255 return (lkb->lkb_flags & DLM_IFL_MSTCPY) ? 1 : 0;
256}
257
258static inline int middle_conversion(struct dlm_lkb *lkb)
259{
260 if ((lkb->lkb_grmode==DLM_LOCK_PR && lkb->lkb_rqmode==DLM_LOCK_CW) ||
261 (lkb->lkb_rqmode==DLM_LOCK_PR && lkb->lkb_grmode==DLM_LOCK_CW))
262 return 1;
263 return 0;
264}
265
266static inline int down_conversion(struct dlm_lkb *lkb)
267{
268 return (!middle_conversion(lkb) && lkb->lkb_rqmode < lkb->lkb_grmode);
269}
270
271static inline int is_overlap_unlock(struct dlm_lkb *lkb)
272{
273 return lkb->lkb_flags & DLM_IFL_OVERLAP_UNLOCK;
274}
275
276static inline int is_overlap_cancel(struct dlm_lkb *lkb)
277{
278 return lkb->lkb_flags & DLM_IFL_OVERLAP_CANCEL;
279}
280
281static inline int is_overlap(struct dlm_lkb *lkb)
282{
283 return (lkb->lkb_flags & (DLM_IFL_OVERLAP_UNLOCK |
284 DLM_IFL_OVERLAP_CANCEL));
285}
286
287static void queue_cast(struct dlm_rsb *r, struct dlm_lkb *lkb, int rv)
288{
289 if (is_master_copy(lkb))
290 return;
291
292 del_timeout(lkb);
293
294 DLM_ASSERT(lkb->lkb_lksb, dlm_print_lkb(lkb););
295
296 /* if the operation was a cancel, then return -DLM_ECANCEL, if a
297 timeout caused the cancel then return -ETIMEDOUT */
298 if (rv == -DLM_ECANCEL && (lkb->lkb_flags & DLM_IFL_TIMEOUT_CANCEL)) {
299 lkb->lkb_flags &= ~DLM_IFL_TIMEOUT_CANCEL;
300 rv = -ETIMEDOUT;
301 }
302
303 if (rv == -DLM_ECANCEL && (lkb->lkb_flags & DLM_IFL_DEADLOCK_CANCEL)) {
304 lkb->lkb_flags &= ~DLM_IFL_DEADLOCK_CANCEL;
305 rv = -EDEADLK;
306 }
307
308 dlm_add_cb(lkb, DLM_CB_CAST, lkb->lkb_grmode, rv, lkb->lkb_sbflags);
309}
310
311static inline void queue_cast_overlap(struct dlm_rsb *r, struct dlm_lkb *lkb)
312{
313 queue_cast(r, lkb,
314 is_overlap_unlock(lkb) ? -DLM_EUNLOCK : -DLM_ECANCEL);
315}
316
317static void queue_bast(struct dlm_rsb *r, struct dlm_lkb *lkb, int rqmode)
318{
319 if (is_master_copy(lkb)) {
320 send_bast(r, lkb, rqmode);
321 } else {
322 dlm_add_cb(lkb, DLM_CB_BAST, rqmode, 0, 0);
323 }
324}
325
326/*
327 * Basic operations on rsb's and lkb's
328 */
329
330static int pre_rsb_struct(struct dlm_ls *ls)
331{
332 struct dlm_rsb *r1, *r2;
333 int count = 0;
334
335 spin_lock(&ls->ls_new_rsb_spin);
336 if (ls->ls_new_rsb_count > dlm_config.ci_new_rsb_count / 2) {
337 spin_unlock(&ls->ls_new_rsb_spin);
338 return 0;
339 }
340 spin_unlock(&ls->ls_new_rsb_spin);
341
342 r1 = dlm_allocate_rsb(ls);
343 r2 = dlm_allocate_rsb(ls);
344
345 spin_lock(&ls->ls_new_rsb_spin);
346 if (r1) {
347 list_add(&r1->res_hashchain, &ls->ls_new_rsb);
348 ls->ls_new_rsb_count++;
349 }
350 if (r2) {
351 list_add(&r2->res_hashchain, &ls->ls_new_rsb);
352 ls->ls_new_rsb_count++;
353 }
354 count = ls->ls_new_rsb_count;
355 spin_unlock(&ls->ls_new_rsb_spin);
356
357 if (!count)
358 return -ENOMEM;
359 return 0;
360}
361
362/* If ls->ls_new_rsb is empty, return -EAGAIN, so the caller can
363 unlock any spinlocks, go back and call pre_rsb_struct again.
364 Otherwise, take an rsb off the list and return it. */
365
366static int get_rsb_struct(struct dlm_ls *ls, char *name, int len,
367 struct dlm_rsb **r_ret)
368{
369 struct dlm_rsb *r;
370 int count;
371
372 spin_lock(&ls->ls_new_rsb_spin);
373 if (list_empty(&ls->ls_new_rsb)) {
374 count = ls->ls_new_rsb_count;
375 spin_unlock(&ls->ls_new_rsb_spin);
376 log_debug(ls, "find_rsb retry %d %d %s",
377 count, dlm_config.ci_new_rsb_count, name);
378 return -EAGAIN;
379 }
380
381 r = list_first_entry(&ls->ls_new_rsb, struct dlm_rsb, res_hashchain);
382 list_del(&r->res_hashchain);
383 ls->ls_new_rsb_count--;
384 spin_unlock(&ls->ls_new_rsb_spin);
385
386 r->res_ls = ls;
387 r->res_length = len;
388 memcpy(r->res_name, name, len);
389 mutex_init(&r->res_mutex);
390
391 INIT_LIST_HEAD(&r->res_hashchain);
392 INIT_LIST_HEAD(&r->res_lookup);
393 INIT_LIST_HEAD(&r->res_grantqueue);
394 INIT_LIST_HEAD(&r->res_convertqueue);
395 INIT_LIST_HEAD(&r->res_waitqueue);
396 INIT_LIST_HEAD(&r->res_root_list);
397 INIT_LIST_HEAD(&r->res_recover_list);
398
399 *r_ret = r;
400 return 0;
401}
402
403static int search_rsb_list(struct list_head *head, char *name, int len,
404 unsigned int flags, struct dlm_rsb **r_ret)
405{
406 struct dlm_rsb *r;
407 int error = 0;
408
409 list_for_each_entry(r, head, res_hashchain) {
410 if (len == r->res_length && !memcmp(name, r->res_name, len))
411 goto found;
412 }
413 *r_ret = NULL;
414 return -EBADR;
415
416 found:
417 if (r->res_nodeid && (flags & R_MASTER))
418 error = -ENOTBLK;
419 *r_ret = r;
420 return error;
421}
422
423static int _search_rsb(struct dlm_ls *ls, char *name, int len, int b,
424 unsigned int flags, struct dlm_rsb **r_ret)
425{
426 struct dlm_rsb *r;
427 int error;
428
429 error = search_rsb_list(&ls->ls_rsbtbl[b].list, name, len, flags, &r);
430 if (!error) {
431 kref_get(&r->res_ref);
432 goto out;
433 }
434 error = search_rsb_list(&ls->ls_rsbtbl[b].toss, name, len, flags, &r);
435 if (error)
436 goto out;
437
438 list_move(&r->res_hashchain, &ls->ls_rsbtbl[b].list);
439
440 if (dlm_no_directory(ls))
441 goto out;
442
443 if (r->res_nodeid == -1) {
444 rsb_clear_flag(r, RSB_MASTER_UNCERTAIN);
445 r->res_first_lkid = 0;
446 } else if (r->res_nodeid > 0) {
447 rsb_set_flag(r, RSB_MASTER_UNCERTAIN);
448 r->res_first_lkid = 0;
449 } else {
450 DLM_ASSERT(r->res_nodeid == 0, dlm_print_rsb(r););
451 DLM_ASSERT(!rsb_flag(r, RSB_MASTER_UNCERTAIN),);
452 }
453 out:
454 *r_ret = r;
455 return error;
456}
457
458/*
459 * Find rsb in rsbtbl and potentially create/add one
460 *
461 * Delaying the release of rsb's has a similar benefit to applications keeping
462 * NL locks on an rsb, but without the guarantee that the cached master value
463 * will still be valid when the rsb is reused. Apps aren't always smart enough
464 * to keep NL locks on an rsb that they may lock again shortly; this can lead
465 * to excessive master lookups and removals if we don't delay the release.
466 *
467 * Searching for an rsb means looking through both the normal list and toss
468 * list. When found on the toss list the rsb is moved to the normal list with
469 * ref count of 1; when found on normal list the ref count is incremented.
470 */
471
472static int find_rsb(struct dlm_ls *ls, char *name, int namelen,
473 unsigned int flags, struct dlm_rsb **r_ret)
474{
475 struct dlm_rsb *r = NULL;
476 uint32_t hash, bucket;
477 int error;
478
479 if (namelen > DLM_RESNAME_MAXLEN) {
480 error = -EINVAL;
481 goto out;
482 }
483
484 if (dlm_no_directory(ls))
485 flags |= R_CREATE;
486
487 hash = jhash(name, namelen, 0);
488 bucket = hash & (ls->ls_rsbtbl_size - 1);
489
490 retry:
491 if (flags & R_CREATE) {
492 error = pre_rsb_struct(ls);
493 if (error < 0)
494 goto out;
495 }
496
497 spin_lock(&ls->ls_rsbtbl[bucket].lock);
498
499 error = _search_rsb(ls, name, namelen, bucket, flags, &r);
500 if (!error)
501 goto out_unlock;
502
503 if (error == -EBADR && !(flags & R_CREATE))
504 goto out_unlock;
505
506 /* the rsb was found but wasn't a master copy */
507 if (error == -ENOTBLK)
508 goto out_unlock;
509
510 error = get_rsb_struct(ls, name, namelen, &r);
511 if (error == -EAGAIN) {
512 spin_unlock(&ls->ls_rsbtbl[bucket].lock);
513 goto retry;
514 }
515 if (error)
516 goto out_unlock;
517
518 r->res_hash = hash;
519 r->res_bucket = bucket;
520 r->res_nodeid = -1;
521 kref_init(&r->res_ref);
522
523 /* With no directory, the master can be set immediately */
524 if (dlm_no_directory(ls)) {
525 int nodeid = dlm_dir_nodeid(r);
526 if (nodeid == dlm_our_nodeid())
527 nodeid = 0;
528 r->res_nodeid = nodeid;
529 }
530 list_add(&r->res_hashchain, &ls->ls_rsbtbl[bucket].list);
531 error = 0;
532 out_unlock:
533 spin_unlock(&ls->ls_rsbtbl[bucket].lock);
534 out:
535 *r_ret = r;
536 return error;
537}
538
539/* This is only called to add a reference when the code already holds
540 a valid reference to the rsb, so there's no need for locking. */
541
542static inline void hold_rsb(struct dlm_rsb *r)
543{
544 kref_get(&r->res_ref);
545}
546
547void dlm_hold_rsb(struct dlm_rsb *r)
548{
549 hold_rsb(r);
550}
551
552static void toss_rsb(struct kref *kref)
553{
554 struct dlm_rsb *r = container_of(kref, struct dlm_rsb, res_ref);
555 struct dlm_ls *ls = r->res_ls;
556
557 DLM_ASSERT(list_empty(&r->res_root_list), dlm_print_rsb(r););
558 kref_init(&r->res_ref);
559 list_move(&r->res_hashchain, &ls->ls_rsbtbl[r->res_bucket].toss);
560 r->res_toss_time = jiffies;
561 if (r->res_lvbptr) {
562 dlm_free_lvb(r->res_lvbptr);
563 r->res_lvbptr = NULL;
564 }
565}
566
567/* When all references to the rsb are gone it's transferred to
568 the tossed list for later disposal. */
569
570static void put_rsb(struct dlm_rsb *r)
571{
572 struct dlm_ls *ls = r->res_ls;
573 uint32_t bucket = r->res_bucket;
574
575 spin_lock(&ls->ls_rsbtbl[bucket].lock);
576 kref_put(&r->res_ref, toss_rsb);
577 spin_unlock(&ls->ls_rsbtbl[bucket].lock);
578}
579
580void dlm_put_rsb(struct dlm_rsb *r)
581{
582 put_rsb(r);
583}
584
585/* See comment for unhold_lkb */
586
587static void unhold_rsb(struct dlm_rsb *r)
588{
589 int rv;
590 rv = kref_put(&r->res_ref, toss_rsb);
591 DLM_ASSERT(!rv, dlm_dump_rsb(r););
592}
593
594static void kill_rsb(struct kref *kref)
595{
596 struct dlm_rsb *r = container_of(kref, struct dlm_rsb, res_ref);
597
598 /* All work is done after the return from kref_put() so we
599 can release the write_lock before the remove and free. */
600
601 DLM_ASSERT(list_empty(&r->res_lookup), dlm_dump_rsb(r););
602 DLM_ASSERT(list_empty(&r->res_grantqueue), dlm_dump_rsb(r););
603 DLM_ASSERT(list_empty(&r->res_convertqueue), dlm_dump_rsb(r););
604 DLM_ASSERT(list_empty(&r->res_waitqueue), dlm_dump_rsb(r););
605 DLM_ASSERT(list_empty(&r->res_root_list), dlm_dump_rsb(r););
606 DLM_ASSERT(list_empty(&r->res_recover_list), dlm_dump_rsb(r););
607}
608
609/* Attaching/detaching lkb's from rsb's is for rsb reference counting.
610 The rsb must exist as long as any lkb's for it do. */
611
612static void attach_lkb(struct dlm_rsb *r, struct dlm_lkb *lkb)
613{
614 hold_rsb(r);
615 lkb->lkb_resource = r;
616}
617
618static void detach_lkb(struct dlm_lkb *lkb)
619{
620 if (lkb->lkb_resource) {
621 put_rsb(lkb->lkb_resource);
622 lkb->lkb_resource = NULL;
623 }
624}
625
626static int create_lkb(struct dlm_ls *ls, struct dlm_lkb **lkb_ret)
627{
628 struct dlm_lkb *lkb;
629 int rv, id;
630
631 lkb = dlm_allocate_lkb(ls);
632 if (!lkb)
633 return -ENOMEM;
634
635 lkb->lkb_nodeid = -1;
636 lkb->lkb_grmode = DLM_LOCK_IV;
637 kref_init(&lkb->lkb_ref);
638 INIT_LIST_HEAD(&lkb->lkb_ownqueue);
639 INIT_LIST_HEAD(&lkb->lkb_rsb_lookup);
640 INIT_LIST_HEAD(&lkb->lkb_time_list);
641 INIT_LIST_HEAD(&lkb->lkb_cb_list);
642 mutex_init(&lkb->lkb_cb_mutex);
643 INIT_WORK(&lkb->lkb_cb_work, dlm_callback_work);
644
645 retry:
646 rv = idr_pre_get(&ls->ls_lkbidr, GFP_NOFS);
647 if (!rv)
648 return -ENOMEM;
649
650 spin_lock(&ls->ls_lkbidr_spin);
651 rv = idr_get_new_above(&ls->ls_lkbidr, lkb, 1, &id);
652 if (!rv)
653 lkb->lkb_id = id;
654 spin_unlock(&ls->ls_lkbidr_spin);
655
656 if (rv == -EAGAIN)
657 goto retry;
658
659 if (rv < 0) {
660 log_error(ls, "create_lkb idr error %d", rv);
661 return rv;
662 }
663
664 *lkb_ret = lkb;
665 return 0;
666}
667
668static int find_lkb(struct dlm_ls *ls, uint32_t lkid, struct dlm_lkb **lkb_ret)
669{
670 struct dlm_lkb *lkb;
671
672 spin_lock(&ls->ls_lkbidr_spin);
673 lkb = idr_find(&ls->ls_lkbidr, lkid);
674 if (lkb)
675 kref_get(&lkb->lkb_ref);
676 spin_unlock(&ls->ls_lkbidr_spin);
677
678 *lkb_ret = lkb;
679 return lkb ? 0 : -ENOENT;
680}
681
682static void kill_lkb(struct kref *kref)
683{
684 struct dlm_lkb *lkb = container_of(kref, struct dlm_lkb, lkb_ref);
685
686 /* All work is done after the return from kref_put() so we
687 can release the write_lock before the detach_lkb */
688
689 DLM_ASSERT(!lkb->lkb_status, dlm_print_lkb(lkb););
690}
691
692/* __put_lkb() is used when an lkb may not have an rsb attached to
693 it so we need to provide the lockspace explicitly */
694
695static int __put_lkb(struct dlm_ls *ls, struct dlm_lkb *lkb)
696{
697 uint32_t lkid = lkb->lkb_id;
698
699 spin_lock(&ls->ls_lkbidr_spin);
700 if (kref_put(&lkb->lkb_ref, kill_lkb)) {
701 idr_remove(&ls->ls_lkbidr, lkid);
702 spin_unlock(&ls->ls_lkbidr_spin);
703
704 detach_lkb(lkb);
705
706 /* for local/process lkbs, lvbptr points to caller's lksb */
707 if (lkb->lkb_lvbptr && is_master_copy(lkb))
708 dlm_free_lvb(lkb->lkb_lvbptr);
709 dlm_free_lkb(lkb);
710 return 1;
711 } else {
712 spin_unlock(&ls->ls_lkbidr_spin);
713 return 0;
714 }
715}
716
717int dlm_put_lkb(struct dlm_lkb *lkb)
718{
719 struct dlm_ls *ls;
720
721 DLM_ASSERT(lkb->lkb_resource, dlm_print_lkb(lkb););
722 DLM_ASSERT(lkb->lkb_resource->res_ls, dlm_print_lkb(lkb););
723
724 ls = lkb->lkb_resource->res_ls;
725 return __put_lkb(ls, lkb);
726}
727
728/* This is only called to add a reference when the code already holds
729 a valid reference to the lkb, so there's no need for locking. */
730
731static inline void hold_lkb(struct dlm_lkb *lkb)
732{
733 kref_get(&lkb->lkb_ref);
734}
735
736/* This is called when we need to remove a reference and are certain
737 it's not the last ref. e.g. del_lkb is always called between a
738 find_lkb/put_lkb and is always the inverse of a previous add_lkb.
739 put_lkb would work fine, but would involve unnecessary locking */
740
741static inline void unhold_lkb(struct dlm_lkb *lkb)
742{
743 int rv;
744 rv = kref_put(&lkb->lkb_ref, kill_lkb);
745 DLM_ASSERT(!rv, dlm_print_lkb(lkb););
746}
747
748static void lkb_add_ordered(struct list_head *new, struct list_head *head,
749 int mode)
750{
751 struct dlm_lkb *lkb = NULL;
752
753 list_for_each_entry(lkb, head, lkb_statequeue)
754 if (lkb->lkb_rqmode < mode)
755 break;
756
757 __list_add(new, lkb->lkb_statequeue.prev, &lkb->lkb_statequeue);
758}
759
760/* add/remove lkb to rsb's grant/convert/wait queue */
761
762static void add_lkb(struct dlm_rsb *r, struct dlm_lkb *lkb, int status)
763{
764 kref_get(&lkb->lkb_ref);
765
766 DLM_ASSERT(!lkb->lkb_status, dlm_print_lkb(lkb););
767
768 lkb->lkb_timestamp = ktime_get();
769
770 lkb->lkb_status = status;
771
772 switch (status) {
773 case DLM_LKSTS_WAITING:
774 if (lkb->lkb_exflags & DLM_LKF_HEADQUE)
775 list_add(&lkb->lkb_statequeue, &r->res_waitqueue);
776 else
777 list_add_tail(&lkb->lkb_statequeue, &r->res_waitqueue);
778 break;
779 case DLM_LKSTS_GRANTED:
780 /* convention says granted locks kept in order of grmode */
781 lkb_add_ordered(&lkb->lkb_statequeue, &r->res_grantqueue,
782 lkb->lkb_grmode);
783 break;
784 case DLM_LKSTS_CONVERT:
785 if (lkb->lkb_exflags & DLM_LKF_HEADQUE)
786 list_add(&lkb->lkb_statequeue, &r->res_convertqueue);
787 else
788 list_add_tail(&lkb->lkb_statequeue,
789 &r->res_convertqueue);
790 break;
791 default:
792 DLM_ASSERT(0, dlm_print_lkb(lkb); printk("sts=%d\n", status););
793 }
794}
795
796static void del_lkb(struct dlm_rsb *r, struct dlm_lkb *lkb)
797{
798 lkb->lkb_status = 0;
799 list_del(&lkb->lkb_statequeue);
800 unhold_lkb(lkb);
801}
802
803static void move_lkb(struct dlm_rsb *r, struct dlm_lkb *lkb, int sts)
804{
805 hold_lkb(lkb);
806 del_lkb(r, lkb);
807 add_lkb(r, lkb, sts);
808 unhold_lkb(lkb);
809}
810
811static int msg_reply_type(int mstype)
812{
813 switch (mstype) {
814 case DLM_MSG_REQUEST:
815 return DLM_MSG_REQUEST_REPLY;
816 case DLM_MSG_CONVERT:
817 return DLM_MSG_CONVERT_REPLY;
818 case DLM_MSG_UNLOCK:
819 return DLM_MSG_UNLOCK_REPLY;
820 case DLM_MSG_CANCEL:
821 return DLM_MSG_CANCEL_REPLY;
822 case DLM_MSG_LOOKUP:
823 return DLM_MSG_LOOKUP_REPLY;
824 }
825 return -1;
826}
827
828static int nodeid_warned(int nodeid, int num_nodes, int *warned)
829{
830 int i;
831
832 for (i = 0; i < num_nodes; i++) {
833 if (!warned[i]) {
834 warned[i] = nodeid;
835 return 0;
836 }
837 if (warned[i] == nodeid)
838 return 1;
839 }
840 return 0;
841}
842
843void dlm_scan_waiters(struct dlm_ls *ls)
844{
845 struct dlm_lkb *lkb;
846 ktime_t zero = ktime_set(0, 0);
847 s64 us;
848 s64 debug_maxus = 0;
849 u32 debug_scanned = 0;
850 u32 debug_expired = 0;
851 int num_nodes = 0;
852 int *warned = NULL;
853
854 if (!dlm_config.ci_waitwarn_us)
855 return;
856
857 mutex_lock(&ls->ls_waiters_mutex);
858
859 list_for_each_entry(lkb, &ls->ls_waiters, lkb_wait_reply) {
860 if (ktime_equal(lkb->lkb_wait_time, zero))
861 continue;
862
863 debug_scanned++;
864
865 us = ktime_to_us(ktime_sub(ktime_get(), lkb->lkb_wait_time));
866
867 if (us < dlm_config.ci_waitwarn_us)
868 continue;
869
870 lkb->lkb_wait_time = zero;
871
872 debug_expired++;
873 if (us > debug_maxus)
874 debug_maxus = us;
875
876 if (!num_nodes) {
877 num_nodes = ls->ls_num_nodes;
878 warned = kzalloc(num_nodes * sizeof(int), GFP_KERNEL);
879 }
880 if (!warned)
881 continue;
882 if (nodeid_warned(lkb->lkb_wait_nodeid, num_nodes, warned))
883 continue;
884
885 log_error(ls, "waitwarn %x %lld %d us check connection to "
886 "node %d", lkb->lkb_id, (long long)us,
887 dlm_config.ci_waitwarn_us, lkb->lkb_wait_nodeid);
888 }
889 mutex_unlock(&ls->ls_waiters_mutex);
890 kfree(warned);
891
892 if (debug_expired)
893 log_debug(ls, "scan_waiters %u warn %u over %d us max %lld us",
894 debug_scanned, debug_expired,
895 dlm_config.ci_waitwarn_us, (long long)debug_maxus);
896}
897
898/* add/remove lkb from global waiters list of lkb's waiting for
899 a reply from a remote node */
900
901static int add_to_waiters(struct dlm_lkb *lkb, int mstype, int to_nodeid)
902{
903 struct dlm_ls *ls = lkb->lkb_resource->res_ls;
904 int error = 0;
905
906 mutex_lock(&ls->ls_waiters_mutex);
907
908 if (is_overlap_unlock(lkb) ||
909 (is_overlap_cancel(lkb) && (mstype == DLM_MSG_CANCEL))) {
910 error = -EINVAL;
911 goto out;
912 }
913
914 if (lkb->lkb_wait_type || is_overlap_cancel(lkb)) {
915 switch (mstype) {
916 case DLM_MSG_UNLOCK:
917 lkb->lkb_flags |= DLM_IFL_OVERLAP_UNLOCK;
918 break;
919 case DLM_MSG_CANCEL:
920 lkb->lkb_flags |= DLM_IFL_OVERLAP_CANCEL;
921 break;
922 default:
923 error = -EBUSY;
924 goto out;
925 }
926 lkb->lkb_wait_count++;
927 hold_lkb(lkb);
928
929 log_debug(ls, "addwait %x cur %d overlap %d count %d f %x",
930 lkb->lkb_id, lkb->lkb_wait_type, mstype,
931 lkb->lkb_wait_count, lkb->lkb_flags);
932 goto out;
933 }
934
935 DLM_ASSERT(!lkb->lkb_wait_count,
936 dlm_print_lkb(lkb);
937 printk("wait_count %d\n", lkb->lkb_wait_count););
938
939 lkb->lkb_wait_count++;
940 lkb->lkb_wait_type = mstype;
941 lkb->lkb_wait_time = ktime_get();
942 lkb->lkb_wait_nodeid = to_nodeid; /* for debugging */
943 hold_lkb(lkb);
944 list_add(&lkb->lkb_wait_reply, &ls->ls_waiters);
945 out:
946 if (error)
947 log_error(ls, "addwait error %x %d flags %x %d %d %s",
948 lkb->lkb_id, error, lkb->lkb_flags, mstype,
949 lkb->lkb_wait_type, lkb->lkb_resource->res_name);
950 mutex_unlock(&ls->ls_waiters_mutex);
951 return error;
952}
953
954/* We clear the RESEND flag because we might be taking an lkb off the waiters
955 list as part of process_requestqueue (e.g. a lookup that has an optimized
956 request reply on the requestqueue) between dlm_recover_waiters_pre() which
957 set RESEND and dlm_recover_waiters_post() */
958
959static int _remove_from_waiters(struct dlm_lkb *lkb, int mstype,
960 struct dlm_message *ms)
961{
962 struct dlm_ls *ls = lkb->lkb_resource->res_ls;
963 int overlap_done = 0;
964
965 if (is_overlap_unlock(lkb) && (mstype == DLM_MSG_UNLOCK_REPLY)) {
966 log_debug(ls, "remwait %x unlock_reply overlap", lkb->lkb_id);
967 lkb->lkb_flags &= ~DLM_IFL_OVERLAP_UNLOCK;
968 overlap_done = 1;
969 goto out_del;
970 }
971
972 if (is_overlap_cancel(lkb) && (mstype == DLM_MSG_CANCEL_REPLY)) {
973 log_debug(ls, "remwait %x cancel_reply overlap", lkb->lkb_id);
974 lkb->lkb_flags &= ~DLM_IFL_OVERLAP_CANCEL;
975 overlap_done = 1;
976 goto out_del;
977 }
978
979 /* Cancel state was preemptively cleared by a successful convert,
980 see next comment, nothing to do. */
981
982 if ((mstype == DLM_MSG_CANCEL_REPLY) &&
983 (lkb->lkb_wait_type != DLM_MSG_CANCEL)) {
984 log_debug(ls, "remwait %x cancel_reply wait_type %d",
985 lkb->lkb_id, lkb->lkb_wait_type);
986 return -1;
987 }
988
989 /* Remove for the convert reply, and premptively remove for the
990 cancel reply. A convert has been granted while there's still
991 an outstanding cancel on it (the cancel is moot and the result
992 in the cancel reply should be 0). We preempt the cancel reply
993 because the app gets the convert result and then can follow up
994 with another op, like convert. This subsequent op would see the
995 lingering state of the cancel and fail with -EBUSY. */
996
997 if ((mstype == DLM_MSG_CONVERT_REPLY) &&
998 (lkb->lkb_wait_type == DLM_MSG_CONVERT) &&
999 is_overlap_cancel(lkb) && ms && !ms->m_result) {
1000 log_debug(ls, "remwait %x convert_reply zap overlap_cancel",
1001 lkb->lkb_id);
1002 lkb->lkb_wait_type = 0;
1003 lkb->lkb_flags &= ~DLM_IFL_OVERLAP_CANCEL;
1004 lkb->lkb_wait_count--;
1005 goto out_del;
1006 }
1007
1008 /* N.B. type of reply may not always correspond to type of original
1009 msg due to lookup->request optimization, verify others? */
1010
1011 if (lkb->lkb_wait_type) {
1012 lkb->lkb_wait_type = 0;
1013 goto out_del;
1014 }
1015
1016 log_error(ls, "remwait error %x reply %d flags %x no wait_type",
1017 lkb->lkb_id, mstype, lkb->lkb_flags);
1018 return -1;
1019
1020 out_del:
1021 /* the force-unlock/cancel has completed and we haven't recvd a reply
1022 to the op that was in progress prior to the unlock/cancel; we
1023 give up on any reply to the earlier op. FIXME: not sure when/how
1024 this would happen */
1025
1026 if (overlap_done && lkb->lkb_wait_type) {
1027 log_error(ls, "remwait error %x reply %d wait_type %d overlap",
1028 lkb->lkb_id, mstype, lkb->lkb_wait_type);
1029 lkb->lkb_wait_count--;
1030 lkb->lkb_wait_type = 0;
1031 }
1032
1033 DLM_ASSERT(lkb->lkb_wait_count, dlm_print_lkb(lkb););
1034
1035 lkb->lkb_flags &= ~DLM_IFL_RESEND;
1036 lkb->lkb_wait_count--;
1037 if (!lkb->lkb_wait_count)
1038 list_del_init(&lkb->lkb_wait_reply);
1039 unhold_lkb(lkb);
1040 return 0;
1041}
1042
1043static int remove_from_waiters(struct dlm_lkb *lkb, int mstype)
1044{
1045 struct dlm_ls *ls = lkb->lkb_resource->res_ls;
1046 int error;
1047
1048 mutex_lock(&ls->ls_waiters_mutex);
1049 error = _remove_from_waiters(lkb, mstype, NULL);
1050 mutex_unlock(&ls->ls_waiters_mutex);
1051 return error;
1052}
1053
1054/* Handles situations where we might be processing a "fake" or "stub" reply in
1055 which we can't try to take waiters_mutex again. */
1056
1057static int remove_from_waiters_ms(struct dlm_lkb *lkb, struct dlm_message *ms)
1058{
1059 struct dlm_ls *ls = lkb->lkb_resource->res_ls;
1060 int error;
1061
1062 if (ms->m_flags != DLM_IFL_STUB_MS)
1063 mutex_lock(&ls->ls_waiters_mutex);
1064 error = _remove_from_waiters(lkb, ms->m_type, ms);
1065 if (ms->m_flags != DLM_IFL_STUB_MS)
1066 mutex_unlock(&ls->ls_waiters_mutex);
1067 return error;
1068}
1069
1070static void dir_remove(struct dlm_rsb *r)
1071{
1072 int to_nodeid;
1073
1074 if (dlm_no_directory(r->res_ls))
1075 return;
1076
1077 to_nodeid = dlm_dir_nodeid(r);
1078 if (to_nodeid != dlm_our_nodeid())
1079 send_remove(r);
1080 else
1081 dlm_dir_remove_entry(r->res_ls, to_nodeid,
1082 r->res_name, r->res_length);
1083}
1084
1085/* FIXME: shouldn't this be able to exit as soon as one non-due rsb is
1086 found since they are in order of newest to oldest? */
1087
1088static int shrink_bucket(struct dlm_ls *ls, int b)
1089{
1090 struct dlm_rsb *r;
1091 int count = 0, found;
1092
1093 for (;;) {
1094 found = 0;
1095 spin_lock(&ls->ls_rsbtbl[b].lock);
1096 list_for_each_entry_reverse(r, &ls->ls_rsbtbl[b].toss,
1097 res_hashchain) {
1098 if (!time_after_eq(jiffies, r->res_toss_time +
1099 dlm_config.ci_toss_secs * HZ))
1100 continue;
1101 found = 1;
1102 break;
1103 }
1104
1105 if (!found) {
1106 spin_unlock(&ls->ls_rsbtbl[b].lock);
1107 break;
1108 }
1109
1110 if (kref_put(&r->res_ref, kill_rsb)) {
1111 list_del(&r->res_hashchain);
1112 spin_unlock(&ls->ls_rsbtbl[b].lock);
1113
1114 if (is_master(r))
1115 dir_remove(r);
1116 dlm_free_rsb(r);
1117 count++;
1118 } else {
1119 spin_unlock(&ls->ls_rsbtbl[b].lock);
1120 log_error(ls, "tossed rsb in use %s", r->res_name);
1121 }
1122 }
1123
1124 return count;
1125}
1126
1127void dlm_scan_rsbs(struct dlm_ls *ls)
1128{
1129 int i;
1130
1131 for (i = 0; i < ls->ls_rsbtbl_size; i++) {
1132 shrink_bucket(ls, i);
1133 if (dlm_locking_stopped(ls))
1134 break;
1135 cond_resched();
1136 }
1137}
1138
1139static void add_timeout(struct dlm_lkb *lkb)
1140{
1141 struct dlm_ls *ls = lkb->lkb_resource->res_ls;
1142
1143 if (is_master_copy(lkb))
1144 return;
1145
1146 if (test_bit(LSFL_TIMEWARN, &ls->ls_flags) &&
1147 !(lkb->lkb_exflags & DLM_LKF_NODLCKWT)) {
1148 lkb->lkb_flags |= DLM_IFL_WATCH_TIMEWARN;
1149 goto add_it;
1150 }
1151 if (lkb->lkb_exflags & DLM_LKF_TIMEOUT)
1152 goto add_it;
1153 return;
1154
1155 add_it:
1156 DLM_ASSERT(list_empty(&lkb->lkb_time_list), dlm_print_lkb(lkb););
1157 mutex_lock(&ls->ls_timeout_mutex);
1158 hold_lkb(lkb);
1159 list_add_tail(&lkb->lkb_time_list, &ls->ls_timeout);
1160 mutex_unlock(&ls->ls_timeout_mutex);
1161}
1162
1163static void del_timeout(struct dlm_lkb *lkb)
1164{
1165 struct dlm_ls *ls = lkb->lkb_resource->res_ls;
1166
1167 mutex_lock(&ls->ls_timeout_mutex);
1168 if (!list_empty(&lkb->lkb_time_list)) {
1169 list_del_init(&lkb->lkb_time_list);
1170 unhold_lkb(lkb);
1171 }
1172 mutex_unlock(&ls->ls_timeout_mutex);
1173}
1174
1175/* FIXME: is it safe to look at lkb_exflags, lkb_flags, lkb_timestamp, and
1176 lkb_lksb_timeout without lock_rsb? Note: we can't lock timeout_mutex
1177 and then lock rsb because of lock ordering in add_timeout. We may need
1178 to specify some special timeout-related bits in the lkb that are just to
1179 be accessed under the timeout_mutex. */
1180
1181void dlm_scan_timeout(struct dlm_ls *ls)
1182{
1183 struct dlm_rsb *r;
1184 struct dlm_lkb *lkb;
1185 int do_cancel, do_warn;
1186 s64 wait_us;
1187
1188 for (;;) {
1189 if (dlm_locking_stopped(ls))
1190 break;
1191
1192 do_cancel = 0;
1193 do_warn = 0;
1194 mutex_lock(&ls->ls_timeout_mutex);
1195 list_for_each_entry(lkb, &ls->ls_timeout, lkb_time_list) {
1196
1197 wait_us = ktime_to_us(ktime_sub(ktime_get(),
1198 lkb->lkb_timestamp));
1199
1200 if ((lkb->lkb_exflags & DLM_LKF_TIMEOUT) &&
1201 wait_us >= (lkb->lkb_timeout_cs * 10000))
1202 do_cancel = 1;
1203
1204 if ((lkb->lkb_flags & DLM_IFL_WATCH_TIMEWARN) &&
1205 wait_us >= dlm_config.ci_timewarn_cs * 10000)
1206 do_warn = 1;
1207
1208 if (!do_cancel && !do_warn)
1209 continue;
1210 hold_lkb(lkb);
1211 break;
1212 }
1213 mutex_unlock(&ls->ls_timeout_mutex);
1214
1215 if (!do_cancel && !do_warn)
1216 break;
1217
1218 r = lkb->lkb_resource;
1219 hold_rsb(r);
1220 lock_rsb(r);
1221
1222 if (do_warn) {
1223 /* clear flag so we only warn once */
1224 lkb->lkb_flags &= ~DLM_IFL_WATCH_TIMEWARN;
1225 if (!(lkb->lkb_exflags & DLM_LKF_TIMEOUT))
1226 del_timeout(lkb);
1227 dlm_timeout_warn(lkb);
1228 }
1229
1230 if (do_cancel) {
1231 log_debug(ls, "timeout cancel %x node %d %s",
1232 lkb->lkb_id, lkb->lkb_nodeid, r->res_name);
1233 lkb->lkb_flags &= ~DLM_IFL_WATCH_TIMEWARN;
1234 lkb->lkb_flags |= DLM_IFL_TIMEOUT_CANCEL;
1235 del_timeout(lkb);
1236 _cancel_lock(r, lkb);
1237 }
1238
1239 unlock_rsb(r);
1240 unhold_rsb(r);
1241 dlm_put_lkb(lkb);
1242 }
1243}
1244
1245/* This is only called by dlm_recoverd, and we rely on dlm_ls_stop() stopping
1246 dlm_recoverd before checking/setting ls_recover_begin. */
1247
1248void dlm_adjust_timeouts(struct dlm_ls *ls)
1249{
1250 struct dlm_lkb *lkb;
1251 u64 adj_us = jiffies_to_usecs(jiffies - ls->ls_recover_begin);
1252
1253 ls->ls_recover_begin = 0;
1254 mutex_lock(&ls->ls_timeout_mutex);
1255 list_for_each_entry(lkb, &ls->ls_timeout, lkb_time_list)
1256 lkb->lkb_timestamp = ktime_add_us(lkb->lkb_timestamp, adj_us);
1257 mutex_unlock(&ls->ls_timeout_mutex);
1258
1259 if (!dlm_config.ci_waitwarn_us)
1260 return;
1261
1262 mutex_lock(&ls->ls_waiters_mutex);
1263 list_for_each_entry(lkb, &ls->ls_waiters, lkb_wait_reply) {
1264 if (ktime_to_us(lkb->lkb_wait_time))
1265 lkb->lkb_wait_time = ktime_get();
1266 }
1267 mutex_unlock(&ls->ls_waiters_mutex);
1268}
1269
1270/* lkb is master or local copy */
1271
1272static void set_lvb_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
1273{
1274 int b, len = r->res_ls->ls_lvblen;
1275
1276 /* b=1 lvb returned to caller
1277 b=0 lvb written to rsb or invalidated
1278 b=-1 do nothing */
1279
1280 b = dlm_lvb_operations[lkb->lkb_grmode + 1][lkb->lkb_rqmode + 1];
1281
1282 if (b == 1) {
1283 if (!lkb->lkb_lvbptr)
1284 return;
1285
1286 if (!(lkb->lkb_exflags & DLM_LKF_VALBLK))
1287 return;
1288
1289 if (!r->res_lvbptr)
1290 return;
1291
1292 memcpy(lkb->lkb_lvbptr, r->res_lvbptr, len);
1293 lkb->lkb_lvbseq = r->res_lvbseq;
1294
1295 } else if (b == 0) {
1296 if (lkb->lkb_exflags & DLM_LKF_IVVALBLK) {
1297 rsb_set_flag(r, RSB_VALNOTVALID);
1298 return;
1299 }
1300
1301 if (!lkb->lkb_lvbptr)
1302 return;
1303
1304 if (!(lkb->lkb_exflags & DLM_LKF_VALBLK))
1305 return;
1306
1307 if (!r->res_lvbptr)
1308 r->res_lvbptr = dlm_allocate_lvb(r->res_ls);
1309
1310 if (!r->res_lvbptr)
1311 return;
1312
1313 memcpy(r->res_lvbptr, lkb->lkb_lvbptr, len);
1314 r->res_lvbseq++;
1315 lkb->lkb_lvbseq = r->res_lvbseq;
1316 rsb_clear_flag(r, RSB_VALNOTVALID);
1317 }
1318
1319 if (rsb_flag(r, RSB_VALNOTVALID))
1320 lkb->lkb_sbflags |= DLM_SBF_VALNOTVALID;
1321}
1322
1323static void set_lvb_unlock(struct dlm_rsb *r, struct dlm_lkb *lkb)
1324{
1325 if (lkb->lkb_grmode < DLM_LOCK_PW)
1326 return;
1327
1328 if (lkb->lkb_exflags & DLM_LKF_IVVALBLK) {
1329 rsb_set_flag(r, RSB_VALNOTVALID);
1330 return;
1331 }
1332
1333 if (!lkb->lkb_lvbptr)
1334 return;
1335
1336 if (!(lkb->lkb_exflags & DLM_LKF_VALBLK))
1337 return;
1338
1339 if (!r->res_lvbptr)
1340 r->res_lvbptr = dlm_allocate_lvb(r->res_ls);
1341
1342 if (!r->res_lvbptr)
1343 return;
1344
1345 memcpy(r->res_lvbptr, lkb->lkb_lvbptr, r->res_ls->ls_lvblen);
1346 r->res_lvbseq++;
1347 rsb_clear_flag(r, RSB_VALNOTVALID);
1348}
1349
1350/* lkb is process copy (pc) */
1351
1352static void set_lvb_lock_pc(struct dlm_rsb *r, struct dlm_lkb *lkb,
1353 struct dlm_message *ms)
1354{
1355 int b;
1356
1357 if (!lkb->lkb_lvbptr)
1358 return;
1359
1360 if (!(lkb->lkb_exflags & DLM_LKF_VALBLK))
1361 return;
1362
1363 b = dlm_lvb_operations[lkb->lkb_grmode + 1][lkb->lkb_rqmode + 1];
1364 if (b == 1) {
1365 int len = receive_extralen(ms);
1366 if (len > DLM_RESNAME_MAXLEN)
1367 len = DLM_RESNAME_MAXLEN;
1368 memcpy(lkb->lkb_lvbptr, ms->m_extra, len);
1369 lkb->lkb_lvbseq = ms->m_lvbseq;
1370 }
1371}
1372
1373/* Manipulate lkb's on rsb's convert/granted/waiting queues
1374 remove_lock -- used for unlock, removes lkb from granted
1375 revert_lock -- used for cancel, moves lkb from convert to granted
1376 grant_lock -- used for request and convert, adds lkb to granted or
1377 moves lkb from convert or waiting to granted
1378
1379 Each of these is used for master or local copy lkb's. There is
1380 also a _pc() variation used to make the corresponding change on
1381 a process copy (pc) lkb. */
1382
1383static void _remove_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
1384{
1385 del_lkb(r, lkb);
1386 lkb->lkb_grmode = DLM_LOCK_IV;
1387 /* this unhold undoes the original ref from create_lkb()
1388 so this leads to the lkb being freed */
1389 unhold_lkb(lkb);
1390}
1391
1392static void remove_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
1393{
1394 set_lvb_unlock(r, lkb);
1395 _remove_lock(r, lkb);
1396}
1397
1398static void remove_lock_pc(struct dlm_rsb *r, struct dlm_lkb *lkb)
1399{
1400 _remove_lock(r, lkb);
1401}
1402
1403/* returns: 0 did nothing
1404 1 moved lock to granted
1405 -1 removed lock */
1406
1407static int revert_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
1408{
1409 int rv = 0;
1410
1411 lkb->lkb_rqmode = DLM_LOCK_IV;
1412
1413 switch (lkb->lkb_status) {
1414 case DLM_LKSTS_GRANTED:
1415 break;
1416 case DLM_LKSTS_CONVERT:
1417 move_lkb(r, lkb, DLM_LKSTS_GRANTED);
1418 rv = 1;
1419 break;
1420 case DLM_LKSTS_WAITING:
1421 del_lkb(r, lkb);
1422 lkb->lkb_grmode = DLM_LOCK_IV;
1423 /* this unhold undoes the original ref from create_lkb()
1424 so this leads to the lkb being freed */
1425 unhold_lkb(lkb);
1426 rv = -1;
1427 break;
1428 default:
1429 log_print("invalid status for revert %d", lkb->lkb_status);
1430 }
1431 return rv;
1432}
1433
1434static int revert_lock_pc(struct dlm_rsb *r, struct dlm_lkb *lkb)
1435{
1436 return revert_lock(r, lkb);
1437}
1438
1439static void _grant_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
1440{
1441 if (lkb->lkb_grmode != lkb->lkb_rqmode) {
1442 lkb->lkb_grmode = lkb->lkb_rqmode;
1443 if (lkb->lkb_status)
1444 move_lkb(r, lkb, DLM_LKSTS_GRANTED);
1445 else
1446 add_lkb(r, lkb, DLM_LKSTS_GRANTED);
1447 }
1448
1449 lkb->lkb_rqmode = DLM_LOCK_IV;
1450}
1451
1452static void grant_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
1453{
1454 set_lvb_lock(r, lkb);
1455 _grant_lock(r, lkb);
1456 lkb->lkb_highbast = 0;
1457}
1458
1459static void grant_lock_pc(struct dlm_rsb *r, struct dlm_lkb *lkb,
1460 struct dlm_message *ms)
1461{
1462 set_lvb_lock_pc(r, lkb, ms);
1463 _grant_lock(r, lkb);
1464}
1465
1466/* called by grant_pending_locks() which means an async grant message must
1467 be sent to the requesting node in addition to granting the lock if the
1468 lkb belongs to a remote node. */
1469
1470static void grant_lock_pending(struct dlm_rsb *r, struct dlm_lkb *lkb)
1471{
1472 grant_lock(r, lkb);
1473 if (is_master_copy(lkb))
1474 send_grant(r, lkb);
1475 else
1476 queue_cast(r, lkb, 0);
1477}
1478
1479/* The special CONVDEADLK, ALTPR and ALTCW flags allow the master to
1480 change the granted/requested modes. We're munging things accordingly in
1481 the process copy.
1482 CONVDEADLK: our grmode may have been forced down to NL to resolve a
1483 conversion deadlock
1484 ALTPR/ALTCW: our rqmode may have been changed to PR or CW to become
1485 compatible with other granted locks */
1486
1487static void munge_demoted(struct dlm_lkb *lkb)
1488{
1489 if (lkb->lkb_rqmode == DLM_LOCK_IV || lkb->lkb_grmode == DLM_LOCK_IV) {
1490 log_print("munge_demoted %x invalid modes gr %d rq %d",
1491 lkb->lkb_id, lkb->lkb_grmode, lkb->lkb_rqmode);
1492 return;
1493 }
1494
1495 lkb->lkb_grmode = DLM_LOCK_NL;
1496}
1497
1498static void munge_altmode(struct dlm_lkb *lkb, struct dlm_message *ms)
1499{
1500 if (ms->m_type != DLM_MSG_REQUEST_REPLY &&
1501 ms->m_type != DLM_MSG_GRANT) {
1502 log_print("munge_altmode %x invalid reply type %d",
1503 lkb->lkb_id, ms->m_type);
1504 return;
1505 }
1506
1507 if (lkb->lkb_exflags & DLM_LKF_ALTPR)
1508 lkb->lkb_rqmode = DLM_LOCK_PR;
1509 else if (lkb->lkb_exflags & DLM_LKF_ALTCW)
1510 lkb->lkb_rqmode = DLM_LOCK_CW;
1511 else {
1512 log_print("munge_altmode invalid exflags %x", lkb->lkb_exflags);
1513 dlm_print_lkb(lkb);
1514 }
1515}
1516
1517static inline int first_in_list(struct dlm_lkb *lkb, struct list_head *head)
1518{
1519 struct dlm_lkb *first = list_entry(head->next, struct dlm_lkb,
1520 lkb_statequeue);
1521 if (lkb->lkb_id == first->lkb_id)
1522 return 1;
1523
1524 return 0;
1525}
1526
1527/* Check if the given lkb conflicts with another lkb on the queue. */
1528
1529static int queue_conflict(struct list_head *head, struct dlm_lkb *lkb)
1530{
1531 struct dlm_lkb *this;
1532
1533 list_for_each_entry(this, head, lkb_statequeue) {
1534 if (this == lkb)
1535 continue;
1536 if (!modes_compat(this, lkb))
1537 return 1;
1538 }
1539 return 0;
1540}
1541
1542/*
1543 * "A conversion deadlock arises with a pair of lock requests in the converting
1544 * queue for one resource. The granted mode of each lock blocks the requested
1545 * mode of the other lock."
1546 *
1547 * Part 2: if the granted mode of lkb is preventing an earlier lkb in the
1548 * convert queue from being granted, then deadlk/demote lkb.
1549 *
1550 * Example:
1551 * Granted Queue: empty
1552 * Convert Queue: NL->EX (first lock)
1553 * PR->EX (second lock)
1554 *
1555 * The first lock can't be granted because of the granted mode of the second
1556 * lock and the second lock can't be granted because it's not first in the
1557 * list. We either cancel lkb's conversion (PR->EX) and return EDEADLK, or we
1558 * demote the granted mode of lkb (from PR to NL) if it has the CONVDEADLK
1559 * flag set and return DEMOTED in the lksb flags.
1560 *
1561 * Originally, this function detected conv-deadlk in a more limited scope:
1562 * - if !modes_compat(lkb1, lkb2) && !modes_compat(lkb2, lkb1), or
1563 * - if lkb1 was the first entry in the queue (not just earlier), and was
1564 * blocked by the granted mode of lkb2, and there was nothing on the
1565 * granted queue preventing lkb1 from being granted immediately, i.e.
1566 * lkb2 was the only thing preventing lkb1 from being granted.
1567 *
1568 * That second condition meant we'd only say there was conv-deadlk if
1569 * resolving it (by demotion) would lead to the first lock on the convert
1570 * queue being granted right away. It allowed conversion deadlocks to exist
1571 * between locks on the convert queue while they couldn't be granted anyway.
1572 *
1573 * Now, we detect and take action on conversion deadlocks immediately when
1574 * they're created, even if they may not be immediately consequential. If
1575 * lkb1 exists anywhere in the convert queue and lkb2 comes in with a granted
1576 * mode that would prevent lkb1's conversion from being granted, we do a
1577 * deadlk/demote on lkb2 right away and don't let it onto the convert queue.
1578 * I think this means that the lkb_is_ahead condition below should always
1579 * be zero, i.e. there will never be conv-deadlk between two locks that are
1580 * both already on the convert queue.
1581 */
1582
1583static int conversion_deadlock_detect(struct dlm_rsb *r, struct dlm_lkb *lkb2)
1584{
1585 struct dlm_lkb *lkb1;
1586 int lkb_is_ahead = 0;
1587
1588 list_for_each_entry(lkb1, &r->res_convertqueue, lkb_statequeue) {
1589 if (lkb1 == lkb2) {
1590 lkb_is_ahead = 1;
1591 continue;
1592 }
1593
1594 if (!lkb_is_ahead) {
1595 if (!modes_compat(lkb2, lkb1))
1596 return 1;
1597 } else {
1598 if (!modes_compat(lkb2, lkb1) &&
1599 !modes_compat(lkb1, lkb2))
1600 return 1;
1601 }
1602 }
1603 return 0;
1604}
1605
1606/*
1607 * Return 1 if the lock can be granted, 0 otherwise.
1608 * Also detect and resolve conversion deadlocks.
1609 *
1610 * lkb is the lock to be granted
1611 *
1612 * now is 1 if the function is being called in the context of the
1613 * immediate request, it is 0 if called later, after the lock has been
1614 * queued.
1615 *
1616 * References are from chapter 6 of "VAXcluster Principles" by Roy Davis
1617 */
1618
1619static int _can_be_granted(struct dlm_rsb *r, struct dlm_lkb *lkb, int now)
1620{
1621 int8_t conv = (lkb->lkb_grmode != DLM_LOCK_IV);
1622
1623 /*
1624 * 6-10: Version 5.4 introduced an option to address the phenomenon of
1625 * a new request for a NL mode lock being blocked.
1626 *
1627 * 6-11: If the optional EXPEDITE flag is used with the new NL mode
1628 * request, then it would be granted. In essence, the use of this flag
1629 * tells the Lock Manager to expedite theis request by not considering
1630 * what may be in the CONVERTING or WAITING queues... As of this
1631 * writing, the EXPEDITE flag can be used only with new requests for NL
1632 * mode locks. This flag is not valid for conversion requests.
1633 *
1634 * A shortcut. Earlier checks return an error if EXPEDITE is used in a
1635 * conversion or used with a non-NL requested mode. We also know an
1636 * EXPEDITE request is always granted immediately, so now must always
1637 * be 1. The full condition to grant an expedite request: (now &&
1638 * !conv && lkb->rqmode == DLM_LOCK_NL && (flags & EXPEDITE)) can
1639 * therefore be shortened to just checking the flag.
1640 */
1641
1642 if (lkb->lkb_exflags & DLM_LKF_EXPEDITE)
1643 return 1;
1644
1645 /*
1646 * A shortcut. Without this, !queue_conflict(grantqueue, lkb) would be
1647 * added to the remaining conditions.
1648 */
1649
1650 if (queue_conflict(&r->res_grantqueue, lkb))
1651 goto out;
1652
1653 /*
1654 * 6-3: By default, a conversion request is immediately granted if the
1655 * requested mode is compatible with the modes of all other granted
1656 * locks
1657 */
1658
1659 if (queue_conflict(&r->res_convertqueue, lkb))
1660 goto out;
1661
1662 /*
1663 * 6-5: But the default algorithm for deciding whether to grant or
1664 * queue conversion requests does not by itself guarantee that such
1665 * requests are serviced on a "first come first serve" basis. This, in
1666 * turn, can lead to a phenomenon known as "indefinate postponement".
1667 *
1668 * 6-7: This issue is dealt with by using the optional QUECVT flag with
1669 * the system service employed to request a lock conversion. This flag
1670 * forces certain conversion requests to be queued, even if they are
1671 * compatible with the granted modes of other locks on the same
1672 * resource. Thus, the use of this flag results in conversion requests
1673 * being ordered on a "first come first servce" basis.
1674 *
1675 * DCT: This condition is all about new conversions being able to occur
1676 * "in place" while the lock remains on the granted queue (assuming
1677 * nothing else conflicts.) IOW if QUECVT isn't set, a conversion
1678 * doesn't _have_ to go onto the convert queue where it's processed in
1679 * order. The "now" variable is necessary to distinguish converts
1680 * being received and processed for the first time now, because once a
1681 * convert is moved to the conversion queue the condition below applies
1682 * requiring fifo granting.
1683 */
1684
1685 if (now && conv && !(lkb->lkb_exflags & DLM_LKF_QUECVT))
1686 return 1;
1687
1688 /*
1689 * The NOORDER flag is set to avoid the standard vms rules on grant
1690 * order.
1691 */
1692
1693 if (lkb->lkb_exflags & DLM_LKF_NOORDER)
1694 return 1;
1695
1696 /*
1697 * 6-3: Once in that queue [CONVERTING], a conversion request cannot be
1698 * granted until all other conversion requests ahead of it are granted
1699 * and/or canceled.
1700 */
1701
1702 if (!now && conv && first_in_list(lkb, &r->res_convertqueue))
1703 return 1;
1704
1705 /*
1706 * 6-4: By default, a new request is immediately granted only if all
1707 * three of the following conditions are satisfied when the request is
1708 * issued:
1709 * - The queue of ungranted conversion requests for the resource is
1710 * empty.
1711 * - The queue of ungranted new requests for the resource is empty.
1712 * - The mode of the new request is compatible with the most
1713 * restrictive mode of all granted locks on the resource.
1714 */
1715
1716 if (now && !conv && list_empty(&r->res_convertqueue) &&
1717 list_empty(&r->res_waitqueue))
1718 return 1;
1719
1720 /*
1721 * 6-4: Once a lock request is in the queue of ungranted new requests,
1722 * it cannot be granted until the queue of ungranted conversion
1723 * requests is empty, all ungranted new requests ahead of it are
1724 * granted and/or canceled, and it is compatible with the granted mode
1725 * of the most restrictive lock granted on the resource.
1726 */
1727
1728 if (!now && !conv && list_empty(&r->res_convertqueue) &&
1729 first_in_list(lkb, &r->res_waitqueue))
1730 return 1;
1731 out:
1732 return 0;
1733}
1734
1735static int can_be_granted(struct dlm_rsb *r, struct dlm_lkb *lkb, int now,
1736 int *err)
1737{
1738 int rv;
1739 int8_t alt = 0, rqmode = lkb->lkb_rqmode;
1740 int8_t is_convert = (lkb->lkb_grmode != DLM_LOCK_IV);
1741
1742 if (err)
1743 *err = 0;
1744
1745 rv = _can_be_granted(r, lkb, now);
1746 if (rv)
1747 goto out;
1748
1749 /*
1750 * The CONVDEADLK flag is non-standard and tells the dlm to resolve
1751 * conversion deadlocks by demoting grmode to NL, otherwise the dlm
1752 * cancels one of the locks.
1753 */
1754
1755 if (is_convert && can_be_queued(lkb) &&
1756 conversion_deadlock_detect(r, lkb)) {
1757 if (lkb->lkb_exflags & DLM_LKF_CONVDEADLK) {
1758 lkb->lkb_grmode = DLM_LOCK_NL;
1759 lkb->lkb_sbflags |= DLM_SBF_DEMOTED;
1760 } else if (!(lkb->lkb_exflags & DLM_LKF_NODLCKWT)) {
1761 if (err)
1762 *err = -EDEADLK;
1763 else {
1764 log_print("can_be_granted deadlock %x now %d",
1765 lkb->lkb_id, now);
1766 dlm_dump_rsb(r);
1767 }
1768 }
1769 goto out;
1770 }
1771
1772 /*
1773 * The ALTPR and ALTCW flags are non-standard and tell the dlm to try
1774 * to grant a request in a mode other than the normal rqmode. It's a
1775 * simple way to provide a big optimization to applications that can
1776 * use them.
1777 */
1778
1779 if (rqmode != DLM_LOCK_PR && (lkb->lkb_exflags & DLM_LKF_ALTPR))
1780 alt = DLM_LOCK_PR;
1781 else if (rqmode != DLM_LOCK_CW && (lkb->lkb_exflags & DLM_LKF_ALTCW))
1782 alt = DLM_LOCK_CW;
1783
1784 if (alt) {
1785 lkb->lkb_rqmode = alt;
1786 rv = _can_be_granted(r, lkb, now);
1787 if (rv)
1788 lkb->lkb_sbflags |= DLM_SBF_ALTMODE;
1789 else
1790 lkb->lkb_rqmode = rqmode;
1791 }
1792 out:
1793 return rv;
1794}
1795
1796/* FIXME: I don't think that can_be_granted() can/will demote or find deadlock
1797 for locks pending on the convert list. Once verified (watch for these
1798 log_prints), we should be able to just call _can_be_granted() and not
1799 bother with the demote/deadlk cases here (and there's no easy way to deal
1800 with a deadlk here, we'd have to generate something like grant_lock with
1801 the deadlk error.) */
1802
1803/* Returns the highest requested mode of all blocked conversions; sets
1804 cw if there's a blocked conversion to DLM_LOCK_CW. */
1805
1806static int grant_pending_convert(struct dlm_rsb *r, int high, int *cw)
1807{
1808 struct dlm_lkb *lkb, *s;
1809 int hi, demoted, quit, grant_restart, demote_restart;
1810 int deadlk;
1811
1812 quit = 0;
1813 restart:
1814 grant_restart = 0;
1815 demote_restart = 0;
1816 hi = DLM_LOCK_IV;
1817
1818 list_for_each_entry_safe(lkb, s, &r->res_convertqueue, lkb_statequeue) {
1819 demoted = is_demoted(lkb);
1820 deadlk = 0;
1821
1822 if (can_be_granted(r, lkb, 0, &deadlk)) {
1823 grant_lock_pending(r, lkb);
1824 grant_restart = 1;
1825 continue;
1826 }
1827
1828 if (!demoted && is_demoted(lkb)) {
1829 log_print("WARN: pending demoted %x node %d %s",
1830 lkb->lkb_id, lkb->lkb_nodeid, r->res_name);
1831 demote_restart = 1;
1832 continue;
1833 }
1834
1835 if (deadlk) {
1836 log_print("WARN: pending deadlock %x node %d %s",
1837 lkb->lkb_id, lkb->lkb_nodeid, r->res_name);
1838 dlm_dump_rsb(r);
1839 continue;
1840 }
1841
1842 hi = max_t(int, lkb->lkb_rqmode, hi);
1843
1844 if (cw && lkb->lkb_rqmode == DLM_LOCK_CW)
1845 *cw = 1;
1846 }
1847
1848 if (grant_restart)
1849 goto restart;
1850 if (demote_restart && !quit) {
1851 quit = 1;
1852 goto restart;
1853 }
1854
1855 return max_t(int, high, hi);
1856}
1857
1858static int grant_pending_wait(struct dlm_rsb *r, int high, int *cw)
1859{
1860 struct dlm_lkb *lkb, *s;
1861
1862 list_for_each_entry_safe(lkb, s, &r->res_waitqueue, lkb_statequeue) {
1863 if (can_be_granted(r, lkb, 0, NULL))
1864 grant_lock_pending(r, lkb);
1865 else {
1866 high = max_t(int, lkb->lkb_rqmode, high);
1867 if (lkb->lkb_rqmode == DLM_LOCK_CW)
1868 *cw = 1;
1869 }
1870 }
1871
1872 return high;
1873}
1874
1875/* cw of 1 means there's a lock with a rqmode of DLM_LOCK_CW that's blocked
1876 on either the convert or waiting queue.
1877 high is the largest rqmode of all locks blocked on the convert or
1878 waiting queue. */
1879
1880static int lock_requires_bast(struct dlm_lkb *gr, int high, int cw)
1881{
1882 if (gr->lkb_grmode == DLM_LOCK_PR && cw) {
1883 if (gr->lkb_highbast < DLM_LOCK_EX)
1884 return 1;
1885 return 0;
1886 }
1887
1888 if (gr->lkb_highbast < high &&
1889 !__dlm_compat_matrix[gr->lkb_grmode+1][high+1])
1890 return 1;
1891 return 0;
1892}
1893
1894static void grant_pending_locks(struct dlm_rsb *r)
1895{
1896 struct dlm_lkb *lkb, *s;
1897 int high = DLM_LOCK_IV;
1898 int cw = 0;
1899
1900 DLM_ASSERT(is_master(r), dlm_dump_rsb(r););
1901
1902 high = grant_pending_convert(r, high, &cw);
1903 high = grant_pending_wait(r, high, &cw);
1904
1905 if (high == DLM_LOCK_IV)
1906 return;
1907
1908 /*
1909 * If there are locks left on the wait/convert queue then send blocking
1910 * ASTs to granted locks based on the largest requested mode (high)
1911 * found above.
1912 */
1913
1914 list_for_each_entry_safe(lkb, s, &r->res_grantqueue, lkb_statequeue) {
1915 if (lkb->lkb_bastfn && lock_requires_bast(lkb, high, cw)) {
1916 if (cw && high == DLM_LOCK_PR &&
1917 lkb->lkb_grmode == DLM_LOCK_PR)
1918 queue_bast(r, lkb, DLM_LOCK_CW);
1919 else
1920 queue_bast(r, lkb, high);
1921 lkb->lkb_highbast = high;
1922 }
1923 }
1924}
1925
1926static int modes_require_bast(struct dlm_lkb *gr, struct dlm_lkb *rq)
1927{
1928 if ((gr->lkb_grmode == DLM_LOCK_PR && rq->lkb_rqmode == DLM_LOCK_CW) ||
1929 (gr->lkb_grmode == DLM_LOCK_CW && rq->lkb_rqmode == DLM_LOCK_PR)) {
1930 if (gr->lkb_highbast < DLM_LOCK_EX)
1931 return 1;
1932 return 0;
1933 }
1934
1935 if (gr->lkb_highbast < rq->lkb_rqmode && !modes_compat(gr, rq))
1936 return 1;
1937 return 0;
1938}
1939
1940static void send_bast_queue(struct dlm_rsb *r, struct list_head *head,
1941 struct dlm_lkb *lkb)
1942{
1943 struct dlm_lkb *gr;
1944
1945 list_for_each_entry(gr, head, lkb_statequeue) {
1946 /* skip self when sending basts to convertqueue */
1947 if (gr == lkb)
1948 continue;
1949 if (gr->lkb_bastfn && modes_require_bast(gr, lkb)) {
1950 queue_bast(r, gr, lkb->lkb_rqmode);
1951 gr->lkb_highbast = lkb->lkb_rqmode;
1952 }
1953 }
1954}
1955
1956static void send_blocking_asts(struct dlm_rsb *r, struct dlm_lkb *lkb)
1957{
1958 send_bast_queue(r, &r->res_grantqueue, lkb);
1959}
1960
1961static void send_blocking_asts_all(struct dlm_rsb *r, struct dlm_lkb *lkb)
1962{
1963 send_bast_queue(r, &r->res_grantqueue, lkb);
1964 send_bast_queue(r, &r->res_convertqueue, lkb);
1965}
1966
1967/* set_master(r, lkb) -- set the master nodeid of a resource
1968
1969 The purpose of this function is to set the nodeid field in the given
1970 lkb using the nodeid field in the given rsb. If the rsb's nodeid is
1971 known, it can just be copied to the lkb and the function will return
1972 0. If the rsb's nodeid is _not_ known, it needs to be looked up
1973 before it can be copied to the lkb.
1974
1975 When the rsb nodeid is being looked up remotely, the initial lkb
1976 causing the lookup is kept on the ls_waiters list waiting for the
1977 lookup reply. Other lkb's waiting for the same rsb lookup are kept
1978 on the rsb's res_lookup list until the master is verified.
1979
1980 Return values:
1981 0: nodeid is set in rsb/lkb and the caller should go ahead and use it
1982 1: the rsb master is not available and the lkb has been placed on
1983 a wait queue
1984*/
1985
1986static int set_master(struct dlm_rsb *r, struct dlm_lkb *lkb)
1987{
1988 struct dlm_ls *ls = r->res_ls;
1989 int i, error, dir_nodeid, ret_nodeid, our_nodeid = dlm_our_nodeid();
1990
1991 if (rsb_flag(r, RSB_MASTER_UNCERTAIN)) {
1992 rsb_clear_flag(r, RSB_MASTER_UNCERTAIN);
1993 r->res_first_lkid = lkb->lkb_id;
1994 lkb->lkb_nodeid = r->res_nodeid;
1995 return 0;
1996 }
1997
1998 if (r->res_first_lkid && r->res_first_lkid != lkb->lkb_id) {
1999 list_add_tail(&lkb->lkb_rsb_lookup, &r->res_lookup);
2000 return 1;
2001 }
2002
2003 if (r->res_nodeid == 0) {
2004 lkb->lkb_nodeid = 0;
2005 return 0;
2006 }
2007
2008 if (r->res_nodeid > 0) {
2009 lkb->lkb_nodeid = r->res_nodeid;
2010 return 0;
2011 }
2012
2013 DLM_ASSERT(r->res_nodeid == -1, dlm_dump_rsb(r););
2014
2015 dir_nodeid = dlm_dir_nodeid(r);
2016
2017 if (dir_nodeid != our_nodeid) {
2018 r->res_first_lkid = lkb->lkb_id;
2019 send_lookup(r, lkb);
2020 return 1;
2021 }
2022
2023 for (i = 0; i < 2; i++) {
2024 /* It's possible for dlm_scand to remove an old rsb for
2025 this same resource from the toss list, us to create
2026 a new one, look up the master locally, and find it
2027 already exists just before dlm_scand does the
2028 dir_remove() on the previous rsb. */
2029
2030 error = dlm_dir_lookup(ls, our_nodeid, r->res_name,
2031 r->res_length, &ret_nodeid);
2032 if (!error)
2033 break;
2034 log_debug(ls, "dir_lookup error %d %s", error, r->res_name);
2035 schedule();
2036 }
2037 if (error && error != -EEXIST)
2038 return error;
2039
2040 if (ret_nodeid == our_nodeid) {
2041 r->res_first_lkid = 0;
2042 r->res_nodeid = 0;
2043 lkb->lkb_nodeid = 0;
2044 } else {
2045 r->res_first_lkid = lkb->lkb_id;
2046 r->res_nodeid = ret_nodeid;
2047 lkb->lkb_nodeid = ret_nodeid;
2048 }
2049 return 0;
2050}
2051
2052static void process_lookup_list(struct dlm_rsb *r)
2053{
2054 struct dlm_lkb *lkb, *safe;
2055
2056 list_for_each_entry_safe(lkb, safe, &r->res_lookup, lkb_rsb_lookup) {
2057 list_del_init(&lkb->lkb_rsb_lookup);
2058 _request_lock(r, lkb);
2059 schedule();
2060 }
2061}
2062
2063/* confirm_master -- confirm (or deny) an rsb's master nodeid */
2064
2065static void confirm_master(struct dlm_rsb *r, int error)
2066{
2067 struct dlm_lkb *lkb;
2068
2069 if (!r->res_first_lkid)
2070 return;
2071
2072 switch (error) {
2073 case 0:
2074 case -EINPROGRESS:
2075 r->res_first_lkid = 0;
2076 process_lookup_list(r);
2077 break;
2078
2079 case -EAGAIN:
2080 case -EBADR:
2081 case -ENOTBLK:
2082 /* the remote request failed and won't be retried (it was
2083 a NOQUEUE, or has been canceled/unlocked); make a waiting
2084 lkb the first_lkid */
2085
2086 r->res_first_lkid = 0;
2087
2088 if (!list_empty(&r->res_lookup)) {
2089 lkb = list_entry(r->res_lookup.next, struct dlm_lkb,
2090 lkb_rsb_lookup);
2091 list_del_init(&lkb->lkb_rsb_lookup);
2092 r->res_first_lkid = lkb->lkb_id;
2093 _request_lock(r, lkb);
2094 }
2095 break;
2096
2097 default:
2098 log_error(r->res_ls, "confirm_master unknown error %d", error);
2099 }
2100}
2101
2102static int set_lock_args(int mode, struct dlm_lksb *lksb, uint32_t flags,
2103 int namelen, unsigned long timeout_cs,
2104 void (*ast) (void *astparam),
2105 void *astparam,
2106 void (*bast) (void *astparam, int mode),
2107 struct dlm_args *args)
2108{
2109 int rv = -EINVAL;
2110
2111 /* check for invalid arg usage */
2112
2113 if (mode < 0 || mode > DLM_LOCK_EX)
2114 goto out;
2115
2116 if (!(flags & DLM_LKF_CONVERT) && (namelen > DLM_RESNAME_MAXLEN))
2117 goto out;
2118
2119 if (flags & DLM_LKF_CANCEL)
2120 goto out;
2121
2122 if (flags & DLM_LKF_QUECVT && !(flags & DLM_LKF_CONVERT))
2123 goto out;
2124
2125 if (flags & DLM_LKF_CONVDEADLK && !(flags & DLM_LKF_CONVERT))
2126 goto out;
2127
2128 if (flags & DLM_LKF_CONVDEADLK && flags & DLM_LKF_NOQUEUE)
2129 goto out;
2130
2131 if (flags & DLM_LKF_EXPEDITE && flags & DLM_LKF_CONVERT)
2132 goto out;
2133
2134 if (flags & DLM_LKF_EXPEDITE && flags & DLM_LKF_QUECVT)
2135 goto out;
2136
2137 if (flags & DLM_LKF_EXPEDITE && flags & DLM_LKF_NOQUEUE)
2138 goto out;
2139
2140 if (flags & DLM_LKF_EXPEDITE && mode != DLM_LOCK_NL)
2141 goto out;
2142
2143 if (!ast || !lksb)
2144 goto out;
2145
2146 if (flags & DLM_LKF_VALBLK && !lksb->sb_lvbptr)
2147 goto out;
2148
2149 if (flags & DLM_LKF_CONVERT && !lksb->sb_lkid)
2150 goto out;
2151
2152 /* these args will be copied to the lkb in validate_lock_args,
2153 it cannot be done now because when converting locks, fields in
2154 an active lkb cannot be modified before locking the rsb */
2155
2156 args->flags = flags;
2157 args->astfn = ast;
2158 args->astparam = astparam;
2159 args->bastfn = bast;
2160 args->timeout = timeout_cs;
2161 args->mode = mode;
2162 args->lksb = lksb;
2163 rv = 0;
2164 out:
2165 return rv;
2166}
2167
2168static int set_unlock_args(uint32_t flags, void *astarg, struct dlm_args *args)
2169{
2170 if (flags & ~(DLM_LKF_CANCEL | DLM_LKF_VALBLK | DLM_LKF_IVVALBLK |
2171 DLM_LKF_FORCEUNLOCK))
2172 return -EINVAL;
2173
2174 if (flags & DLM_LKF_CANCEL && flags & DLM_LKF_FORCEUNLOCK)
2175 return -EINVAL;
2176
2177 args->flags = flags;
2178 args->astparam = astarg;
2179 return 0;
2180}
2181
2182static int validate_lock_args(struct dlm_ls *ls, struct dlm_lkb *lkb,
2183 struct dlm_args *args)
2184{
2185 int rv = -EINVAL;
2186
2187 if (args->flags & DLM_LKF_CONVERT) {
2188 if (lkb->lkb_flags & DLM_IFL_MSTCPY)
2189 goto out;
2190
2191 if (args->flags & DLM_LKF_QUECVT &&
2192 !__quecvt_compat_matrix[lkb->lkb_grmode+1][args->mode+1])
2193 goto out;
2194
2195 rv = -EBUSY;
2196 if (lkb->lkb_status != DLM_LKSTS_GRANTED)
2197 goto out;
2198
2199 if (lkb->lkb_wait_type)
2200 goto out;
2201
2202 if (is_overlap(lkb))
2203 goto out;
2204 }
2205
2206 lkb->lkb_exflags = args->flags;
2207 lkb->lkb_sbflags = 0;
2208 lkb->lkb_astfn = args->astfn;
2209 lkb->lkb_astparam = args->astparam;
2210 lkb->lkb_bastfn = args->bastfn;
2211 lkb->lkb_rqmode = args->mode;
2212 lkb->lkb_lksb = args->lksb;
2213 lkb->lkb_lvbptr = args->lksb->sb_lvbptr;
2214 lkb->lkb_ownpid = (int) current->pid;
2215 lkb->lkb_timeout_cs = args->timeout;
2216 rv = 0;
2217 out:
2218 if (rv)
2219 log_debug(ls, "validate_lock_args %d %x %x %x %d %d %s",
2220 rv, lkb->lkb_id, lkb->lkb_flags, args->flags,
2221 lkb->lkb_status, lkb->lkb_wait_type,
2222 lkb->lkb_resource->res_name);
2223 return rv;
2224}
2225
2226/* when dlm_unlock() sees -EBUSY with CANCEL/FORCEUNLOCK it returns 0
2227 for success */
2228
2229/* note: it's valid for lkb_nodeid/res_nodeid to be -1 when we get here
2230 because there may be a lookup in progress and it's valid to do
2231 cancel/unlockf on it */
2232
2233static int validate_unlock_args(struct dlm_lkb *lkb, struct dlm_args *args)
2234{
2235 struct dlm_ls *ls = lkb->lkb_resource->res_ls;
2236 int rv = -EINVAL;
2237
2238 if (lkb->lkb_flags & DLM_IFL_MSTCPY) {
2239 log_error(ls, "unlock on MSTCPY %x", lkb->lkb_id);
2240 dlm_print_lkb(lkb);
2241 goto out;
2242 }
2243
2244 /* an lkb may still exist even though the lock is EOL'ed due to a
2245 cancel, unlock or failed noqueue request; an app can't use these
2246 locks; return same error as if the lkid had not been found at all */
2247
2248 if (lkb->lkb_flags & DLM_IFL_ENDOFLIFE) {
2249 log_debug(ls, "unlock on ENDOFLIFE %x", lkb->lkb_id);
2250 rv = -ENOENT;
2251 goto out;
2252 }
2253
2254 /* an lkb may be waiting for an rsb lookup to complete where the
2255 lookup was initiated by another lock */
2256
2257 if (!list_empty(&lkb->lkb_rsb_lookup)) {
2258 if (args->flags & (DLM_LKF_CANCEL | DLM_LKF_FORCEUNLOCK)) {
2259 log_debug(ls, "unlock on rsb_lookup %x", lkb->lkb_id);
2260 list_del_init(&lkb->lkb_rsb_lookup);
2261 queue_cast(lkb->lkb_resource, lkb,
2262 args->flags & DLM_LKF_CANCEL ?
2263 -DLM_ECANCEL : -DLM_EUNLOCK);
2264 unhold_lkb(lkb); /* undoes create_lkb() */
2265 }
2266 /* caller changes -EBUSY to 0 for CANCEL and FORCEUNLOCK */
2267 rv = -EBUSY;
2268 goto out;
2269 }
2270
2271 /* cancel not allowed with another cancel/unlock in progress */
2272
2273 if (args->flags & DLM_LKF_CANCEL) {
2274 if (lkb->lkb_exflags & DLM_LKF_CANCEL)
2275 goto out;
2276
2277 if (is_overlap(lkb))
2278 goto out;
2279
2280 /* don't let scand try to do a cancel */
2281 del_timeout(lkb);
2282
2283 if (lkb->lkb_flags & DLM_IFL_RESEND) {
2284 lkb->lkb_flags |= DLM_IFL_OVERLAP_CANCEL;
2285 rv = -EBUSY;
2286 goto out;
2287 }
2288
2289 /* there's nothing to cancel */
2290 if (lkb->lkb_status == DLM_LKSTS_GRANTED &&
2291 !lkb->lkb_wait_type) {
2292 rv = -EBUSY;
2293 goto out;
2294 }
2295
2296 switch (lkb->lkb_wait_type) {
2297 case DLM_MSG_LOOKUP:
2298 case DLM_MSG_REQUEST:
2299 lkb->lkb_flags |= DLM_IFL_OVERLAP_CANCEL;
2300 rv = -EBUSY;
2301 goto out;
2302 case DLM_MSG_UNLOCK:
2303 case DLM_MSG_CANCEL:
2304 goto out;
2305 }
2306 /* add_to_waiters() will set OVERLAP_CANCEL */
2307 goto out_ok;
2308 }
2309
2310 /* do we need to allow a force-unlock if there's a normal unlock
2311 already in progress? in what conditions could the normal unlock
2312 fail such that we'd want to send a force-unlock to be sure? */
2313
2314 if (args->flags & DLM_LKF_FORCEUNLOCK) {
2315 if (lkb->lkb_exflags & DLM_LKF_FORCEUNLOCK)
2316 goto out;
2317
2318 if (is_overlap_unlock(lkb))
2319 goto out;
2320
2321 /* don't let scand try to do a cancel */
2322 del_timeout(lkb);
2323
2324 if (lkb->lkb_flags & DLM_IFL_RESEND) {
2325 lkb->lkb_flags |= DLM_IFL_OVERLAP_UNLOCK;
2326 rv = -EBUSY;
2327 goto out;
2328 }
2329
2330 switch (lkb->lkb_wait_type) {
2331 case DLM_MSG_LOOKUP:
2332 case DLM_MSG_REQUEST:
2333 lkb->lkb_flags |= DLM_IFL_OVERLAP_UNLOCK;
2334 rv = -EBUSY;
2335 goto out;
2336 case DLM_MSG_UNLOCK:
2337 goto out;
2338 }
2339 /* add_to_waiters() will set OVERLAP_UNLOCK */
2340 goto out_ok;
2341 }
2342
2343 /* normal unlock not allowed if there's any op in progress */
2344 rv = -EBUSY;
2345 if (lkb->lkb_wait_type || lkb->lkb_wait_count)
2346 goto out;
2347
2348 out_ok:
2349 /* an overlapping op shouldn't blow away exflags from other op */
2350 lkb->lkb_exflags |= args->flags;
2351 lkb->lkb_sbflags = 0;
2352 lkb->lkb_astparam = args->astparam;
2353 rv = 0;
2354 out:
2355 if (rv)
2356 log_debug(ls, "validate_unlock_args %d %x %x %x %x %d %s", rv,
2357 lkb->lkb_id, lkb->lkb_flags, lkb->lkb_exflags,
2358 args->flags, lkb->lkb_wait_type,
2359 lkb->lkb_resource->res_name);
2360 return rv;
2361}
2362
2363/*
2364 * Four stage 4 varieties:
2365 * do_request(), do_convert(), do_unlock(), do_cancel()
2366 * These are called on the master node for the given lock and
2367 * from the central locking logic.
2368 */
2369
2370static int do_request(struct dlm_rsb *r, struct dlm_lkb *lkb)
2371{
2372 int error = 0;
2373
2374 if (can_be_granted(r, lkb, 1, NULL)) {
2375 grant_lock(r, lkb);
2376 queue_cast(r, lkb, 0);
2377 goto out;
2378 }
2379
2380 if (can_be_queued(lkb)) {
2381 error = -EINPROGRESS;
2382 add_lkb(r, lkb, DLM_LKSTS_WAITING);
2383 add_timeout(lkb);
2384 goto out;
2385 }
2386
2387 error = -EAGAIN;
2388 queue_cast(r, lkb, -EAGAIN);
2389 out:
2390 return error;
2391}
2392
2393static void do_request_effects(struct dlm_rsb *r, struct dlm_lkb *lkb,
2394 int error)
2395{
2396 switch (error) {
2397 case -EAGAIN:
2398 if (force_blocking_asts(lkb))
2399 send_blocking_asts_all(r, lkb);
2400 break;
2401 case -EINPROGRESS:
2402 send_blocking_asts(r, lkb);
2403 break;
2404 }
2405}
2406
2407static int do_convert(struct dlm_rsb *r, struct dlm_lkb *lkb)
2408{
2409 int error = 0;
2410 int deadlk = 0;
2411
2412 /* changing an existing lock may allow others to be granted */
2413
2414 if (can_be_granted(r, lkb, 1, &deadlk)) {
2415 grant_lock(r, lkb);
2416 queue_cast(r, lkb, 0);
2417 goto out;
2418 }
2419
2420 /* can_be_granted() detected that this lock would block in a conversion
2421 deadlock, so we leave it on the granted queue and return EDEADLK in
2422 the ast for the convert. */
2423
2424 if (deadlk) {
2425 /* it's left on the granted queue */
2426 revert_lock(r, lkb);
2427 queue_cast(r, lkb, -EDEADLK);
2428 error = -EDEADLK;
2429 goto out;
2430 }
2431
2432 /* is_demoted() means the can_be_granted() above set the grmode
2433 to NL, and left us on the granted queue. This auto-demotion
2434 (due to CONVDEADLK) might mean other locks, and/or this lock, are
2435 now grantable. We have to try to grant other converting locks
2436 before we try again to grant this one. */
2437
2438 if (is_demoted(lkb)) {
2439 grant_pending_convert(r, DLM_LOCK_IV, NULL);
2440 if (_can_be_granted(r, lkb, 1)) {
2441 grant_lock(r, lkb);
2442 queue_cast(r, lkb, 0);
2443 goto out;
2444 }
2445 /* else fall through and move to convert queue */
2446 }
2447
2448 if (can_be_queued(lkb)) {
2449 error = -EINPROGRESS;
2450 del_lkb(r, lkb);
2451 add_lkb(r, lkb, DLM_LKSTS_CONVERT);
2452 add_timeout(lkb);
2453 goto out;
2454 }
2455
2456 error = -EAGAIN;
2457 queue_cast(r, lkb, -EAGAIN);
2458 out:
2459 return error;
2460}
2461
2462static void do_convert_effects(struct dlm_rsb *r, struct dlm_lkb *lkb,
2463 int error)
2464{
2465 switch (error) {
2466 case 0:
2467 grant_pending_locks(r);
2468 /* grant_pending_locks also sends basts */
2469 break;
2470 case -EAGAIN:
2471 if (force_blocking_asts(lkb))
2472 send_blocking_asts_all(r, lkb);
2473 break;
2474 case -EINPROGRESS:
2475 send_blocking_asts(r, lkb);
2476 break;
2477 }
2478}
2479
2480static int do_unlock(struct dlm_rsb *r, struct dlm_lkb *lkb)
2481{
2482 remove_lock(r, lkb);
2483 queue_cast(r, lkb, -DLM_EUNLOCK);
2484 return -DLM_EUNLOCK;
2485}
2486
2487static void do_unlock_effects(struct dlm_rsb *r, struct dlm_lkb *lkb,
2488 int error)
2489{
2490 grant_pending_locks(r);
2491}
2492
2493/* returns: 0 did nothing, -DLM_ECANCEL canceled lock */
2494
2495static int do_cancel(struct dlm_rsb *r, struct dlm_lkb *lkb)
2496{
2497 int error;
2498
2499 error = revert_lock(r, lkb);
2500 if (error) {
2501 queue_cast(r, lkb, -DLM_ECANCEL);
2502 return -DLM_ECANCEL;
2503 }
2504 return 0;
2505}
2506
2507static void do_cancel_effects(struct dlm_rsb *r, struct dlm_lkb *lkb,
2508 int error)
2509{
2510 if (error)
2511 grant_pending_locks(r);
2512}
2513
2514/*
2515 * Four stage 3 varieties:
2516 * _request_lock(), _convert_lock(), _unlock_lock(), _cancel_lock()
2517 */
2518
2519/* add a new lkb to a possibly new rsb, called by requesting process */
2520
2521static int _request_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
2522{
2523 int error;
2524
2525 /* set_master: sets lkb nodeid from r */
2526
2527 error = set_master(r, lkb);
2528 if (error < 0)
2529 goto out;
2530 if (error) {
2531 error = 0;
2532 goto out;
2533 }
2534
2535 if (is_remote(r)) {
2536 /* receive_request() calls do_request() on remote node */
2537 error = send_request(r, lkb);
2538 } else {
2539 error = do_request(r, lkb);
2540 /* for remote locks the request_reply is sent
2541 between do_request and do_request_effects */
2542 do_request_effects(r, lkb, error);
2543 }
2544 out:
2545 return error;
2546}
2547
2548/* change some property of an existing lkb, e.g. mode */
2549
2550static int _convert_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
2551{
2552 int error;
2553
2554 if (is_remote(r)) {
2555 /* receive_convert() calls do_convert() on remote node */
2556 error = send_convert(r, lkb);
2557 } else {
2558 error = do_convert(r, lkb);
2559 /* for remote locks the convert_reply is sent
2560 between do_convert and do_convert_effects */
2561 do_convert_effects(r, lkb, error);
2562 }
2563
2564 return error;
2565}
2566
2567/* remove an existing lkb from the granted queue */
2568
2569static int _unlock_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
2570{
2571 int error;
2572
2573 if (is_remote(r)) {
2574 /* receive_unlock() calls do_unlock() on remote node */
2575 error = send_unlock(r, lkb);
2576 } else {
2577 error = do_unlock(r, lkb);
2578 /* for remote locks the unlock_reply is sent
2579 between do_unlock and do_unlock_effects */
2580 do_unlock_effects(r, lkb, error);
2581 }
2582
2583 return error;
2584}
2585
2586/* remove an existing lkb from the convert or wait queue */
2587
2588static int _cancel_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
2589{
2590 int error;
2591
2592 if (is_remote(r)) {
2593 /* receive_cancel() calls do_cancel() on remote node */
2594 error = send_cancel(r, lkb);
2595 } else {
2596 error = do_cancel(r, lkb);
2597 /* for remote locks the cancel_reply is sent
2598 between do_cancel and do_cancel_effects */
2599 do_cancel_effects(r, lkb, error);
2600 }
2601
2602 return error;
2603}
2604
2605/*
2606 * Four stage 2 varieties:
2607 * request_lock(), convert_lock(), unlock_lock(), cancel_lock()
2608 */
2609
2610static int request_lock(struct dlm_ls *ls, struct dlm_lkb *lkb, char *name,
2611 int len, struct dlm_args *args)
2612{
2613 struct dlm_rsb *r;
2614 int error;
2615
2616 error = validate_lock_args(ls, lkb, args);
2617 if (error)
2618 goto out;
2619
2620 error = find_rsb(ls, name, len, R_CREATE, &r);
2621 if (error)
2622 goto out;
2623
2624 lock_rsb(r);
2625
2626 attach_lkb(r, lkb);
2627 lkb->lkb_lksb->sb_lkid = lkb->lkb_id;
2628
2629 error = _request_lock(r, lkb);
2630
2631 unlock_rsb(r);
2632 put_rsb(r);
2633
2634 out:
2635 return error;
2636}
2637
2638static int convert_lock(struct dlm_ls *ls, struct dlm_lkb *lkb,
2639 struct dlm_args *args)
2640{
2641 struct dlm_rsb *r;
2642 int error;
2643
2644 r = lkb->lkb_resource;
2645
2646 hold_rsb(r);
2647 lock_rsb(r);
2648
2649 error = validate_lock_args(ls, lkb, args);
2650 if (error)
2651 goto out;
2652
2653 error = _convert_lock(r, lkb);
2654 out:
2655 unlock_rsb(r);
2656 put_rsb(r);
2657 return error;
2658}
2659
2660static int unlock_lock(struct dlm_ls *ls, struct dlm_lkb *lkb,
2661 struct dlm_args *args)
2662{
2663 struct dlm_rsb *r;
2664 int error;
2665
2666 r = lkb->lkb_resource;
2667
2668 hold_rsb(r);
2669 lock_rsb(r);
2670
2671 error = validate_unlock_args(lkb, args);
2672 if (error)
2673 goto out;
2674
2675 error = _unlock_lock(r, lkb);
2676 out:
2677 unlock_rsb(r);
2678 put_rsb(r);
2679 return error;
2680}
2681
2682static int cancel_lock(struct dlm_ls *ls, struct dlm_lkb *lkb,
2683 struct dlm_args *args)
2684{
2685 struct dlm_rsb *r;
2686 int error;
2687
2688 r = lkb->lkb_resource;
2689
2690 hold_rsb(r);
2691 lock_rsb(r);
2692
2693 error = validate_unlock_args(lkb, args);
2694 if (error)
2695 goto out;
2696
2697 error = _cancel_lock(r, lkb);
2698 out:
2699 unlock_rsb(r);
2700 put_rsb(r);
2701 return error;
2702}
2703
2704/*
2705 * Two stage 1 varieties: dlm_lock() and dlm_unlock()
2706 */
2707
2708int dlm_lock(dlm_lockspace_t *lockspace,
2709 int mode,
2710 struct dlm_lksb *lksb,
2711 uint32_t flags,
2712 void *name,
2713 unsigned int namelen,
2714 uint32_t parent_lkid,
2715 void (*ast) (void *astarg),
2716 void *astarg,
2717 void (*bast) (void *astarg, int mode))
2718{
2719 struct dlm_ls *ls;
2720 struct dlm_lkb *lkb;
2721 struct dlm_args args;
2722 int error, convert = flags & DLM_LKF_CONVERT;
2723
2724 ls = dlm_find_lockspace_local(lockspace);
2725 if (!ls)
2726 return -EINVAL;
2727
2728 dlm_lock_recovery(ls);
2729
2730 if (convert)
2731 error = find_lkb(ls, lksb->sb_lkid, &lkb);
2732 else
2733 error = create_lkb(ls, &lkb);
2734
2735 if (error)
2736 goto out;
2737
2738 error = set_lock_args(mode, lksb, flags, namelen, 0, ast,
2739 astarg, bast, &args);
2740 if (error)
2741 goto out_put;
2742
2743 if (convert)
2744 error = convert_lock(ls, lkb, &args);
2745 else
2746 error = request_lock(ls, lkb, name, namelen, &args);
2747
2748 if (error == -EINPROGRESS)
2749 error = 0;
2750 out_put:
2751 if (convert || error)
2752 __put_lkb(ls, lkb);
2753 if (error == -EAGAIN || error == -EDEADLK)
2754 error = 0;
2755 out:
2756 dlm_unlock_recovery(ls);
2757 dlm_put_lockspace(ls);
2758 return error;
2759}
2760
2761int dlm_unlock(dlm_lockspace_t *lockspace,
2762 uint32_t lkid,
2763 uint32_t flags,
2764 struct dlm_lksb *lksb,
2765 void *astarg)
2766{
2767 struct dlm_ls *ls;
2768 struct dlm_lkb *lkb;
2769 struct dlm_args args;
2770 int error;
2771
2772 ls = dlm_find_lockspace_local(lockspace);
2773 if (!ls)
2774 return -EINVAL;
2775
2776 dlm_lock_recovery(ls);
2777
2778 error = find_lkb(ls, lkid, &lkb);
2779 if (error)
2780 goto out;
2781
2782 error = set_unlock_args(flags, astarg, &args);
2783 if (error)
2784 goto out_put;
2785
2786 if (flags & DLM_LKF_CANCEL)
2787 error = cancel_lock(ls, lkb, &args);
2788 else
2789 error = unlock_lock(ls, lkb, &args);
2790
2791 if (error == -DLM_EUNLOCK || error == -DLM_ECANCEL)
2792 error = 0;
2793 if (error == -EBUSY && (flags & (DLM_LKF_CANCEL | DLM_LKF_FORCEUNLOCK)))
2794 error = 0;
2795 out_put:
2796 dlm_put_lkb(lkb);
2797 out:
2798 dlm_unlock_recovery(ls);
2799 dlm_put_lockspace(ls);
2800 return error;
2801}
2802
2803/*
2804 * send/receive routines for remote operations and replies
2805 *
2806 * send_args
2807 * send_common
2808 * send_request receive_request
2809 * send_convert receive_convert
2810 * send_unlock receive_unlock
2811 * send_cancel receive_cancel
2812 * send_grant receive_grant
2813 * send_bast receive_bast
2814 * send_lookup receive_lookup
2815 * send_remove receive_remove
2816 *
2817 * send_common_reply
2818 * receive_request_reply send_request_reply
2819 * receive_convert_reply send_convert_reply
2820 * receive_unlock_reply send_unlock_reply
2821 * receive_cancel_reply send_cancel_reply
2822 * receive_lookup_reply send_lookup_reply
2823 */
2824
2825static int _create_message(struct dlm_ls *ls, int mb_len,
2826 int to_nodeid, int mstype,
2827 struct dlm_message **ms_ret,
2828 struct dlm_mhandle **mh_ret)
2829{
2830 struct dlm_message *ms;
2831 struct dlm_mhandle *mh;
2832 char *mb;
2833
2834 /* get_buffer gives us a message handle (mh) that we need to
2835 pass into lowcomms_commit and a message buffer (mb) that we
2836 write our data into */
2837
2838 mh = dlm_lowcomms_get_buffer(to_nodeid, mb_len, GFP_NOFS, &mb);
2839 if (!mh)
2840 return -ENOBUFS;
2841
2842 memset(mb, 0, mb_len);
2843
2844 ms = (struct dlm_message *) mb;
2845
2846 ms->m_header.h_version = (DLM_HEADER_MAJOR | DLM_HEADER_MINOR);
2847 ms->m_header.h_lockspace = ls->ls_global_id;
2848 ms->m_header.h_nodeid = dlm_our_nodeid();
2849 ms->m_header.h_length = mb_len;
2850 ms->m_header.h_cmd = DLM_MSG;
2851
2852 ms->m_type = mstype;
2853
2854 *mh_ret = mh;
2855 *ms_ret = ms;
2856 return 0;
2857}
2858
2859static int create_message(struct dlm_rsb *r, struct dlm_lkb *lkb,
2860 int to_nodeid, int mstype,
2861 struct dlm_message **ms_ret,
2862 struct dlm_mhandle **mh_ret)
2863{
2864 int mb_len = sizeof(struct dlm_message);
2865
2866 switch (mstype) {
2867 case DLM_MSG_REQUEST:
2868 case DLM_MSG_LOOKUP:
2869 case DLM_MSG_REMOVE:
2870 mb_len += r->res_length;
2871 break;
2872 case DLM_MSG_CONVERT:
2873 case DLM_MSG_UNLOCK:
2874 case DLM_MSG_REQUEST_REPLY:
2875 case DLM_MSG_CONVERT_REPLY:
2876 case DLM_MSG_GRANT:
2877 if (lkb && lkb->lkb_lvbptr)
2878 mb_len += r->res_ls->ls_lvblen;
2879 break;
2880 }
2881
2882 return _create_message(r->res_ls, mb_len, to_nodeid, mstype,
2883 ms_ret, mh_ret);
2884}
2885
2886/* further lowcomms enhancements or alternate implementations may make
2887 the return value from this function useful at some point */
2888
2889static int send_message(struct dlm_mhandle *mh, struct dlm_message *ms)
2890{
2891 dlm_message_out(ms);
2892 dlm_lowcomms_commit_buffer(mh);
2893 return 0;
2894}
2895
2896static void send_args(struct dlm_rsb *r, struct dlm_lkb *lkb,
2897 struct dlm_message *ms)
2898{
2899 ms->m_nodeid = lkb->lkb_nodeid;
2900 ms->m_pid = lkb->lkb_ownpid;
2901 ms->m_lkid = lkb->lkb_id;
2902 ms->m_remid = lkb->lkb_remid;
2903 ms->m_exflags = lkb->lkb_exflags;
2904 ms->m_sbflags = lkb->lkb_sbflags;
2905 ms->m_flags = lkb->lkb_flags;
2906 ms->m_lvbseq = lkb->lkb_lvbseq;
2907 ms->m_status = lkb->lkb_status;
2908 ms->m_grmode = lkb->lkb_grmode;
2909 ms->m_rqmode = lkb->lkb_rqmode;
2910 ms->m_hash = r->res_hash;
2911
2912 /* m_result and m_bastmode are set from function args,
2913 not from lkb fields */
2914
2915 if (lkb->lkb_bastfn)
2916 ms->m_asts |= DLM_CB_BAST;
2917 if (lkb->lkb_astfn)
2918 ms->m_asts |= DLM_CB_CAST;
2919
2920 /* compare with switch in create_message; send_remove() doesn't
2921 use send_args() */
2922
2923 switch (ms->m_type) {
2924 case DLM_MSG_REQUEST:
2925 case DLM_MSG_LOOKUP:
2926 memcpy(ms->m_extra, r->res_name, r->res_length);
2927 break;
2928 case DLM_MSG_CONVERT:
2929 case DLM_MSG_UNLOCK:
2930 case DLM_MSG_REQUEST_REPLY:
2931 case DLM_MSG_CONVERT_REPLY:
2932 case DLM_MSG_GRANT:
2933 if (!lkb->lkb_lvbptr)
2934 break;
2935 memcpy(ms->m_extra, lkb->lkb_lvbptr, r->res_ls->ls_lvblen);
2936 break;
2937 }
2938}
2939
2940static int send_common(struct dlm_rsb *r, struct dlm_lkb *lkb, int mstype)
2941{
2942 struct dlm_message *ms;
2943 struct dlm_mhandle *mh;
2944 int to_nodeid, error;
2945
2946 to_nodeid = r->res_nodeid;
2947
2948 error = add_to_waiters(lkb, mstype, to_nodeid);
2949 if (error)
2950 return error;
2951
2952 error = create_message(r, lkb, to_nodeid, mstype, &ms, &mh);
2953 if (error)
2954 goto fail;
2955
2956 send_args(r, lkb, ms);
2957
2958 error = send_message(mh, ms);
2959 if (error)
2960 goto fail;
2961 return 0;
2962
2963 fail:
2964 remove_from_waiters(lkb, msg_reply_type(mstype));
2965 return error;
2966}
2967
2968static int send_request(struct dlm_rsb *r, struct dlm_lkb *lkb)
2969{
2970 return send_common(r, lkb, DLM_MSG_REQUEST);
2971}
2972
2973static int send_convert(struct dlm_rsb *r, struct dlm_lkb *lkb)
2974{
2975 int error;
2976
2977 error = send_common(r, lkb, DLM_MSG_CONVERT);
2978
2979 /* down conversions go without a reply from the master */
2980 if (!error && down_conversion(lkb)) {
2981 remove_from_waiters(lkb, DLM_MSG_CONVERT_REPLY);
2982 r->res_ls->ls_stub_ms.m_flags = DLM_IFL_STUB_MS;
2983 r->res_ls->ls_stub_ms.m_type = DLM_MSG_CONVERT_REPLY;
2984 r->res_ls->ls_stub_ms.m_result = 0;
2985 __receive_convert_reply(r, lkb, &r->res_ls->ls_stub_ms);
2986 }
2987
2988 return error;
2989}
2990
2991/* FIXME: if this lkb is the only lock we hold on the rsb, then set
2992 MASTER_UNCERTAIN to force the next request on the rsb to confirm
2993 that the master is still correct. */
2994
2995static int send_unlock(struct dlm_rsb *r, struct dlm_lkb *lkb)
2996{
2997 return send_common(r, lkb, DLM_MSG_UNLOCK);
2998}
2999
3000static int send_cancel(struct dlm_rsb *r, struct dlm_lkb *lkb)
3001{
3002 return send_common(r, lkb, DLM_MSG_CANCEL);
3003}
3004
3005static int send_grant(struct dlm_rsb *r, struct dlm_lkb *lkb)
3006{
3007 struct dlm_message *ms;
3008 struct dlm_mhandle *mh;
3009 int to_nodeid, error;
3010
3011 to_nodeid = lkb->lkb_nodeid;
3012
3013 error = create_message(r, lkb, to_nodeid, DLM_MSG_GRANT, &ms, &mh);
3014 if (error)
3015 goto out;
3016
3017 send_args(r, lkb, ms);
3018
3019 ms->m_result = 0;
3020
3021 error = send_message(mh, ms);
3022 out:
3023 return error;
3024}
3025
3026static int send_bast(struct dlm_rsb *r, struct dlm_lkb *lkb, int mode)
3027{
3028 struct dlm_message *ms;
3029 struct dlm_mhandle *mh;
3030 int to_nodeid, error;
3031
3032 to_nodeid = lkb->lkb_nodeid;
3033
3034 error = create_message(r, NULL, to_nodeid, DLM_MSG_BAST, &ms, &mh);
3035 if (error)
3036 goto out;
3037
3038 send_args(r, lkb, ms);
3039
3040 ms->m_bastmode = mode;
3041
3042 error = send_message(mh, ms);
3043 out:
3044 return error;
3045}
3046
3047static int send_lookup(struct dlm_rsb *r, struct dlm_lkb *lkb)
3048{
3049 struct dlm_message *ms;
3050 struct dlm_mhandle *mh;
3051 int to_nodeid, error;
3052
3053 to_nodeid = dlm_dir_nodeid(r);
3054
3055 error = add_to_waiters(lkb, DLM_MSG_LOOKUP, to_nodeid);
3056 if (error)
3057 return error;
3058
3059 error = create_message(r, NULL, to_nodeid, DLM_MSG_LOOKUP, &ms, &mh);
3060 if (error)
3061 goto fail;
3062
3063 send_args(r, lkb, ms);
3064
3065 error = send_message(mh, ms);
3066 if (error)
3067 goto fail;
3068 return 0;
3069
3070 fail:
3071 remove_from_waiters(lkb, DLM_MSG_LOOKUP_REPLY);
3072 return error;
3073}
3074
3075static int send_remove(struct dlm_rsb *r)
3076{
3077 struct dlm_message *ms;
3078 struct dlm_mhandle *mh;
3079 int to_nodeid, error;
3080
3081 to_nodeid = dlm_dir_nodeid(r);
3082
3083 error = create_message(r, NULL, to_nodeid, DLM_MSG_REMOVE, &ms, &mh);
3084 if (error)
3085 goto out;
3086
3087 memcpy(ms->m_extra, r->res_name, r->res_length);
3088 ms->m_hash = r->res_hash;
3089
3090 error = send_message(mh, ms);
3091 out:
3092 return error;
3093}
3094
3095static int send_common_reply(struct dlm_rsb *r, struct dlm_lkb *lkb,
3096 int mstype, int rv)
3097{
3098 struct dlm_message *ms;
3099 struct dlm_mhandle *mh;
3100 int to_nodeid, error;
3101
3102 to_nodeid = lkb->lkb_nodeid;
3103
3104 error = create_message(r, lkb, to_nodeid, mstype, &ms, &mh);
3105 if (error)
3106 goto out;
3107
3108 send_args(r, lkb, ms);
3109
3110 ms->m_result = rv;
3111
3112 error = send_message(mh, ms);
3113 out:
3114 return error;
3115}
3116
3117static int send_request_reply(struct dlm_rsb *r, struct dlm_lkb *lkb, int rv)
3118{
3119 return send_common_reply(r, lkb, DLM_MSG_REQUEST_REPLY, rv);
3120}
3121
3122static int send_convert_reply(struct dlm_rsb *r, struct dlm_lkb *lkb, int rv)
3123{
3124 return send_common_reply(r, lkb, DLM_MSG_CONVERT_REPLY, rv);
3125}
3126
3127static int send_unlock_reply(struct dlm_rsb *r, struct dlm_lkb *lkb, int rv)
3128{
3129 return send_common_reply(r, lkb, DLM_MSG_UNLOCK_REPLY, rv);
3130}
3131
3132static int send_cancel_reply(struct dlm_rsb *r, struct dlm_lkb *lkb, int rv)
3133{
3134 return send_common_reply(r, lkb, DLM_MSG_CANCEL_REPLY, rv);
3135}
3136
3137static int send_lookup_reply(struct dlm_ls *ls, struct dlm_message *ms_in,
3138 int ret_nodeid, int rv)
3139{
3140 struct dlm_rsb *r = &ls->ls_stub_rsb;
3141 struct dlm_message *ms;
3142 struct dlm_mhandle *mh;
3143 int error, nodeid = ms_in->m_header.h_nodeid;
3144
3145 error = create_message(r, NULL, nodeid, DLM_MSG_LOOKUP_REPLY, &ms, &mh);
3146 if (error)
3147 goto out;
3148
3149 ms->m_lkid = ms_in->m_lkid;
3150 ms->m_result = rv;
3151 ms->m_nodeid = ret_nodeid;
3152
3153 error = send_message(mh, ms);
3154 out:
3155 return error;
3156}
3157
3158/* which args we save from a received message depends heavily on the type
3159 of message, unlike the send side where we can safely send everything about
3160 the lkb for any type of message */
3161
3162static void receive_flags(struct dlm_lkb *lkb, struct dlm_message *ms)
3163{
3164 lkb->lkb_exflags = ms->m_exflags;
3165 lkb->lkb_sbflags = ms->m_sbflags;
3166 lkb->lkb_flags = (lkb->lkb_flags & 0xFFFF0000) |
3167 (ms->m_flags & 0x0000FFFF);
3168}
3169
3170static void receive_flags_reply(struct dlm_lkb *lkb, struct dlm_message *ms)
3171{
3172 if (ms->m_flags == DLM_IFL_STUB_MS)
3173 return;
3174
3175 lkb->lkb_sbflags = ms->m_sbflags;
3176 lkb->lkb_flags = (lkb->lkb_flags & 0xFFFF0000) |
3177 (ms->m_flags & 0x0000FFFF);
3178}
3179
3180static int receive_extralen(struct dlm_message *ms)
3181{
3182 return (ms->m_header.h_length - sizeof(struct dlm_message));
3183}
3184
3185static int receive_lvb(struct dlm_ls *ls, struct dlm_lkb *lkb,
3186 struct dlm_message *ms)
3187{
3188 int len;
3189
3190 if (lkb->lkb_exflags & DLM_LKF_VALBLK) {
3191 if (!lkb->lkb_lvbptr)
3192 lkb->lkb_lvbptr = dlm_allocate_lvb(ls);
3193 if (!lkb->lkb_lvbptr)
3194 return -ENOMEM;
3195 len = receive_extralen(ms);
3196 if (len > DLM_RESNAME_MAXLEN)
3197 len = DLM_RESNAME_MAXLEN;
3198 memcpy(lkb->lkb_lvbptr, ms->m_extra, len);
3199 }
3200 return 0;
3201}
3202
3203static void fake_bastfn(void *astparam, int mode)
3204{
3205 log_print("fake_bastfn should not be called");
3206}
3207
3208static void fake_astfn(void *astparam)
3209{
3210 log_print("fake_astfn should not be called");
3211}
3212
3213static int receive_request_args(struct dlm_ls *ls, struct dlm_lkb *lkb,
3214 struct dlm_message *ms)
3215{
3216 lkb->lkb_nodeid = ms->m_header.h_nodeid;
3217 lkb->lkb_ownpid = ms->m_pid;
3218 lkb->lkb_remid = ms->m_lkid;
3219 lkb->lkb_grmode = DLM_LOCK_IV;
3220 lkb->lkb_rqmode = ms->m_rqmode;
3221
3222 lkb->lkb_bastfn = (ms->m_asts & DLM_CB_BAST) ? &fake_bastfn : NULL;
3223 lkb->lkb_astfn = (ms->m_asts & DLM_CB_CAST) ? &fake_astfn : NULL;
3224
3225 if (lkb->lkb_exflags & DLM_LKF_VALBLK) {
3226 /* lkb was just created so there won't be an lvb yet */
3227 lkb->lkb_lvbptr = dlm_allocate_lvb(ls);
3228 if (!lkb->lkb_lvbptr)
3229 return -ENOMEM;
3230 }
3231
3232 return 0;
3233}
3234
3235static int receive_convert_args(struct dlm_ls *ls, struct dlm_lkb *lkb,
3236 struct dlm_message *ms)
3237{
3238 if (lkb->lkb_status != DLM_LKSTS_GRANTED)
3239 return -EBUSY;
3240
3241 if (receive_lvb(ls, lkb, ms))
3242 return -ENOMEM;
3243
3244 lkb->lkb_rqmode = ms->m_rqmode;
3245 lkb->lkb_lvbseq = ms->m_lvbseq;
3246
3247 return 0;
3248}
3249
3250static int receive_unlock_args(struct dlm_ls *ls, struct dlm_lkb *lkb,
3251 struct dlm_message *ms)
3252{
3253 if (receive_lvb(ls, lkb, ms))
3254 return -ENOMEM;
3255 return 0;
3256}
3257
3258/* We fill in the stub-lkb fields with the info that send_xxxx_reply()
3259 uses to send a reply and that the remote end uses to process the reply. */
3260
3261static void setup_stub_lkb(struct dlm_ls *ls, struct dlm_message *ms)
3262{
3263 struct dlm_lkb *lkb = &ls->ls_stub_lkb;
3264 lkb->lkb_nodeid = ms->m_header.h_nodeid;
3265 lkb->lkb_remid = ms->m_lkid;
3266}
3267
3268/* This is called after the rsb is locked so that we can safely inspect
3269 fields in the lkb. */
3270
3271static int validate_message(struct dlm_lkb *lkb, struct dlm_message *ms)
3272{
3273 int from = ms->m_header.h_nodeid;
3274 int error = 0;
3275
3276 switch (ms->m_type) {
3277 case DLM_MSG_CONVERT:
3278 case DLM_MSG_UNLOCK:
3279 case DLM_MSG_CANCEL:
3280 if (!is_master_copy(lkb) || lkb->lkb_nodeid != from)
3281 error = -EINVAL;
3282 break;
3283
3284 case DLM_MSG_CONVERT_REPLY:
3285 case DLM_MSG_UNLOCK_REPLY:
3286 case DLM_MSG_CANCEL_REPLY:
3287 case DLM_MSG_GRANT:
3288 case DLM_MSG_BAST:
3289 if (!is_process_copy(lkb) || lkb->lkb_nodeid != from)
3290 error = -EINVAL;
3291 break;
3292
3293 case DLM_MSG_REQUEST_REPLY:
3294 if (!is_process_copy(lkb))
3295 error = -EINVAL;
3296 else if (lkb->lkb_nodeid != -1 && lkb->lkb_nodeid != from)
3297 error = -EINVAL;
3298 break;
3299
3300 default:
3301 error = -EINVAL;
3302 }
3303
3304 if (error)
3305 log_error(lkb->lkb_resource->res_ls,
3306 "ignore invalid message %d from %d %x %x %x %d",
3307 ms->m_type, from, lkb->lkb_id, lkb->lkb_remid,
3308 lkb->lkb_flags, lkb->lkb_nodeid);
3309 return error;
3310}
3311
3312static void receive_request(struct dlm_ls *ls, struct dlm_message *ms)
3313{
3314 struct dlm_lkb *lkb;
3315 struct dlm_rsb *r;
3316 int error, namelen;
3317
3318 error = create_lkb(ls, &lkb);
3319 if (error)
3320 goto fail;
3321
3322 receive_flags(lkb, ms);
3323 lkb->lkb_flags |= DLM_IFL_MSTCPY;
3324 error = receive_request_args(ls, lkb, ms);
3325 if (error) {
3326 __put_lkb(ls, lkb);
3327 goto fail;
3328 }
3329
3330 namelen = receive_extralen(ms);
3331
3332 error = find_rsb(ls, ms->m_extra, namelen, R_MASTER, &r);
3333 if (error) {
3334 __put_lkb(ls, lkb);
3335 goto fail;
3336 }
3337
3338 lock_rsb(r);
3339
3340 attach_lkb(r, lkb);
3341 error = do_request(r, lkb);
3342 send_request_reply(r, lkb, error);
3343 do_request_effects(r, lkb, error);
3344
3345 unlock_rsb(r);
3346 put_rsb(r);
3347
3348 if (error == -EINPROGRESS)
3349 error = 0;
3350 if (error)
3351 dlm_put_lkb(lkb);
3352 return;
3353
3354 fail:
3355 setup_stub_lkb(ls, ms);
3356 send_request_reply(&ls->ls_stub_rsb, &ls->ls_stub_lkb, error);
3357}
3358
3359static void receive_convert(struct dlm_ls *ls, struct dlm_message *ms)
3360{
3361 struct dlm_lkb *lkb;
3362 struct dlm_rsb *r;
3363 int error, reply = 1;
3364
3365 error = find_lkb(ls, ms->m_remid, &lkb);
3366 if (error)
3367 goto fail;
3368
3369 r = lkb->lkb_resource;
3370
3371 hold_rsb(r);
3372 lock_rsb(r);
3373
3374 error = validate_message(lkb, ms);
3375 if (error)
3376 goto out;
3377
3378 receive_flags(lkb, ms);
3379
3380 error = receive_convert_args(ls, lkb, ms);
3381 if (error) {
3382 send_convert_reply(r, lkb, error);
3383 goto out;
3384 }
3385
3386 reply = !down_conversion(lkb);
3387
3388 error = do_convert(r, lkb);
3389 if (reply)
3390 send_convert_reply(r, lkb, error);
3391 do_convert_effects(r, lkb, error);
3392 out:
3393 unlock_rsb(r);
3394 put_rsb(r);
3395 dlm_put_lkb(lkb);
3396 return;
3397
3398 fail:
3399 setup_stub_lkb(ls, ms);
3400 send_convert_reply(&ls->ls_stub_rsb, &ls->ls_stub_lkb, error);
3401}
3402
3403static void receive_unlock(struct dlm_ls *ls, struct dlm_message *ms)
3404{
3405 struct dlm_lkb *lkb;
3406 struct dlm_rsb *r;
3407 int error;
3408
3409 error = find_lkb(ls, ms->m_remid, &lkb);
3410 if (error)
3411 goto fail;
3412
3413 r = lkb->lkb_resource;
3414
3415 hold_rsb(r);
3416 lock_rsb(r);
3417
3418 error = validate_message(lkb, ms);
3419 if (error)
3420 goto out;
3421
3422 receive_flags(lkb, ms);
3423
3424 error = receive_unlock_args(ls, lkb, ms);
3425 if (error) {
3426 send_unlock_reply(r, lkb, error);
3427 goto out;
3428 }
3429
3430 error = do_unlock(r, lkb);
3431 send_unlock_reply(r, lkb, error);
3432 do_unlock_effects(r, lkb, error);
3433 out:
3434 unlock_rsb(r);
3435 put_rsb(r);
3436 dlm_put_lkb(lkb);
3437 return;
3438
3439 fail:
3440 setup_stub_lkb(ls, ms);
3441 send_unlock_reply(&ls->ls_stub_rsb, &ls->ls_stub_lkb, error);
3442}
3443
3444static void receive_cancel(struct dlm_ls *ls, struct dlm_message *ms)
3445{
3446 struct dlm_lkb *lkb;
3447 struct dlm_rsb *r;
3448 int error;
3449
3450 error = find_lkb(ls, ms->m_remid, &lkb);
3451 if (error)
3452 goto fail;
3453
3454 receive_flags(lkb, ms);
3455
3456 r = lkb->lkb_resource;
3457
3458 hold_rsb(r);
3459 lock_rsb(r);
3460
3461 error = validate_message(lkb, ms);
3462 if (error)
3463 goto out;
3464
3465 error = do_cancel(r, lkb);
3466 send_cancel_reply(r, lkb, error);
3467 do_cancel_effects(r, lkb, error);
3468 out:
3469 unlock_rsb(r);
3470 put_rsb(r);
3471 dlm_put_lkb(lkb);
3472 return;
3473
3474 fail:
3475 setup_stub_lkb(ls, ms);
3476 send_cancel_reply(&ls->ls_stub_rsb, &ls->ls_stub_lkb, error);
3477}
3478
3479static void receive_grant(struct dlm_ls *ls, struct dlm_message *ms)
3480{
3481 struct dlm_lkb *lkb;
3482 struct dlm_rsb *r;
3483 int error;
3484
3485 error = find_lkb(ls, ms->m_remid, &lkb);
3486 if (error) {
3487 log_debug(ls, "receive_grant from %d no lkb %x",
3488 ms->m_header.h_nodeid, ms->m_remid);
3489 return;
3490 }
3491
3492 r = lkb->lkb_resource;
3493
3494 hold_rsb(r);
3495 lock_rsb(r);
3496
3497 error = validate_message(lkb, ms);
3498 if (error)
3499 goto out;
3500
3501 receive_flags_reply(lkb, ms);
3502 if (is_altmode(lkb))
3503 munge_altmode(lkb, ms);
3504 grant_lock_pc(r, lkb, ms);
3505 queue_cast(r, lkb, 0);
3506 out:
3507 unlock_rsb(r);
3508 put_rsb(r);
3509 dlm_put_lkb(lkb);
3510}
3511
3512static void receive_bast(struct dlm_ls *ls, struct dlm_message *ms)
3513{
3514 struct dlm_lkb *lkb;
3515 struct dlm_rsb *r;
3516 int error;
3517
3518 error = find_lkb(ls, ms->m_remid, &lkb);
3519 if (error) {
3520 log_debug(ls, "receive_bast from %d no lkb %x",
3521 ms->m_header.h_nodeid, ms->m_remid);
3522 return;
3523 }
3524
3525 r = lkb->lkb_resource;
3526
3527 hold_rsb(r);
3528 lock_rsb(r);
3529
3530 error = validate_message(lkb, ms);
3531 if (error)
3532 goto out;
3533
3534 queue_bast(r, lkb, ms->m_bastmode);
3535 out:
3536 unlock_rsb(r);
3537 put_rsb(r);
3538 dlm_put_lkb(lkb);
3539}
3540
3541static void receive_lookup(struct dlm_ls *ls, struct dlm_message *ms)
3542{
3543 int len, error, ret_nodeid, dir_nodeid, from_nodeid, our_nodeid;
3544
3545 from_nodeid = ms->m_header.h_nodeid;
3546 our_nodeid = dlm_our_nodeid();
3547
3548 len = receive_extralen(ms);
3549
3550 dir_nodeid = dlm_hash2nodeid(ls, ms->m_hash);
3551 if (dir_nodeid != our_nodeid) {
3552 log_error(ls, "lookup dir_nodeid %d from %d",
3553 dir_nodeid, from_nodeid);
3554 error = -EINVAL;
3555 ret_nodeid = -1;
3556 goto out;
3557 }
3558
3559 error = dlm_dir_lookup(ls, from_nodeid, ms->m_extra, len, &ret_nodeid);
3560
3561 /* Optimization: we're master so treat lookup as a request */
3562 if (!error && ret_nodeid == our_nodeid) {
3563 receive_request(ls, ms);
3564 return;
3565 }
3566 out:
3567 send_lookup_reply(ls, ms, ret_nodeid, error);
3568}
3569
3570static void receive_remove(struct dlm_ls *ls, struct dlm_message *ms)
3571{
3572 int len, dir_nodeid, from_nodeid;
3573
3574 from_nodeid = ms->m_header.h_nodeid;
3575
3576 len = receive_extralen(ms);
3577
3578 dir_nodeid = dlm_hash2nodeid(ls, ms->m_hash);
3579 if (dir_nodeid != dlm_our_nodeid()) {
3580 log_error(ls, "remove dir entry dir_nodeid %d from %d",
3581 dir_nodeid, from_nodeid);
3582 return;
3583 }
3584
3585 dlm_dir_remove_entry(ls, from_nodeid, ms->m_extra, len);
3586}
3587
3588static void receive_purge(struct dlm_ls *ls, struct dlm_message *ms)
3589{
3590 do_purge(ls, ms->m_nodeid, ms->m_pid);
3591}
3592
3593static void receive_request_reply(struct dlm_ls *ls, struct dlm_message *ms)
3594{
3595 struct dlm_lkb *lkb;
3596 struct dlm_rsb *r;
3597 int error, mstype, result;
3598
3599 error = find_lkb(ls, ms->m_remid, &lkb);
3600 if (error) {
3601 log_debug(ls, "receive_request_reply from %d no lkb %x",
3602 ms->m_header.h_nodeid, ms->m_remid);
3603 return;
3604 }
3605
3606 r = lkb->lkb_resource;
3607 hold_rsb(r);
3608 lock_rsb(r);
3609
3610 error = validate_message(lkb, ms);
3611 if (error)
3612 goto out;
3613
3614 mstype = lkb->lkb_wait_type;
3615 error = remove_from_waiters(lkb, DLM_MSG_REQUEST_REPLY);
3616 if (error)
3617 goto out;
3618
3619 /* Optimization: the dir node was also the master, so it took our
3620 lookup as a request and sent request reply instead of lookup reply */
3621 if (mstype == DLM_MSG_LOOKUP) {
3622 r->res_nodeid = ms->m_header.h_nodeid;
3623 lkb->lkb_nodeid = r->res_nodeid;
3624 }
3625
3626 /* this is the value returned from do_request() on the master */
3627 result = ms->m_result;
3628
3629 switch (result) {
3630 case -EAGAIN:
3631 /* request would block (be queued) on remote master */
3632 queue_cast(r, lkb, -EAGAIN);
3633 confirm_master(r, -EAGAIN);
3634 unhold_lkb(lkb); /* undoes create_lkb() */
3635 break;
3636
3637 case -EINPROGRESS:
3638 case 0:
3639 /* request was queued or granted on remote master */
3640 receive_flags_reply(lkb, ms);
3641 lkb->lkb_remid = ms->m_lkid;
3642 if (is_altmode(lkb))
3643 munge_altmode(lkb, ms);
3644 if (result) {
3645 add_lkb(r, lkb, DLM_LKSTS_WAITING);
3646 add_timeout(lkb);
3647 } else {
3648 grant_lock_pc(r, lkb, ms);
3649 queue_cast(r, lkb, 0);
3650 }
3651 confirm_master(r, result);
3652 break;
3653
3654 case -EBADR:
3655 case -ENOTBLK:
3656 /* find_rsb failed to find rsb or rsb wasn't master */
3657 log_debug(ls, "receive_request_reply %x %x master diff %d %d",
3658 lkb->lkb_id, lkb->lkb_flags, r->res_nodeid, result);
3659 r->res_nodeid = -1;
3660 lkb->lkb_nodeid = -1;
3661
3662 if (is_overlap(lkb)) {
3663 /* we'll ignore error in cancel/unlock reply */
3664 queue_cast_overlap(r, lkb);
3665 confirm_master(r, result);
3666 unhold_lkb(lkb); /* undoes create_lkb() */
3667 } else
3668 _request_lock(r, lkb);
3669 break;
3670
3671 default:
3672 log_error(ls, "receive_request_reply %x error %d",
3673 lkb->lkb_id, result);
3674 }
3675
3676 if (is_overlap_unlock(lkb) && (result == 0 || result == -EINPROGRESS)) {
3677 log_debug(ls, "receive_request_reply %x result %d unlock",
3678 lkb->lkb_id, result);
3679 lkb->lkb_flags &= ~DLM_IFL_OVERLAP_UNLOCK;
3680 lkb->lkb_flags &= ~DLM_IFL_OVERLAP_CANCEL;
3681 send_unlock(r, lkb);
3682 } else if (is_overlap_cancel(lkb) && (result == -EINPROGRESS)) {
3683 log_debug(ls, "receive_request_reply %x cancel", lkb->lkb_id);
3684 lkb->lkb_flags &= ~DLM_IFL_OVERLAP_UNLOCK;
3685 lkb->lkb_flags &= ~DLM_IFL_OVERLAP_CANCEL;
3686 send_cancel(r, lkb);
3687 } else {
3688 lkb->lkb_flags &= ~DLM_IFL_OVERLAP_CANCEL;
3689 lkb->lkb_flags &= ~DLM_IFL_OVERLAP_UNLOCK;
3690 }
3691 out:
3692 unlock_rsb(r);
3693 put_rsb(r);
3694 dlm_put_lkb(lkb);
3695}
3696
3697static void __receive_convert_reply(struct dlm_rsb *r, struct dlm_lkb *lkb,
3698 struct dlm_message *ms)
3699{
3700 /* this is the value returned from do_convert() on the master */
3701 switch (ms->m_result) {
3702 case -EAGAIN:
3703 /* convert would block (be queued) on remote master */
3704 queue_cast(r, lkb, -EAGAIN);
3705 break;
3706
3707 case -EDEADLK:
3708 receive_flags_reply(lkb, ms);
3709 revert_lock_pc(r, lkb);
3710 queue_cast(r, lkb, -EDEADLK);
3711 break;
3712
3713 case -EINPROGRESS:
3714 /* convert was queued on remote master */
3715 receive_flags_reply(lkb, ms);
3716 if (is_demoted(lkb))
3717 munge_demoted(lkb);
3718 del_lkb(r, lkb);
3719 add_lkb(r, lkb, DLM_LKSTS_CONVERT);
3720 add_timeout(lkb);
3721 break;
3722
3723 case 0:
3724 /* convert was granted on remote master */
3725 receive_flags_reply(lkb, ms);
3726 if (is_demoted(lkb))
3727 munge_demoted(lkb);
3728 grant_lock_pc(r, lkb, ms);
3729 queue_cast(r, lkb, 0);
3730 break;
3731
3732 default:
3733 log_error(r->res_ls, "receive_convert_reply %x error %d",
3734 lkb->lkb_id, ms->m_result);
3735 }
3736}
3737
3738static void _receive_convert_reply(struct dlm_lkb *lkb, struct dlm_message *ms)
3739{
3740 struct dlm_rsb *r = lkb->lkb_resource;
3741 int error;
3742
3743 hold_rsb(r);
3744 lock_rsb(r);
3745
3746 error = validate_message(lkb, ms);
3747 if (error)
3748 goto out;
3749
3750 /* stub reply can happen with waiters_mutex held */
3751 error = remove_from_waiters_ms(lkb, ms);
3752 if (error)
3753 goto out;
3754
3755 __receive_convert_reply(r, lkb, ms);
3756 out:
3757 unlock_rsb(r);
3758 put_rsb(r);
3759}
3760
3761static void receive_convert_reply(struct dlm_ls *ls, struct dlm_message *ms)
3762{
3763 struct dlm_lkb *lkb;
3764 int error;
3765
3766 error = find_lkb(ls, ms->m_remid, &lkb);
3767 if (error) {
3768 log_debug(ls, "receive_convert_reply from %d no lkb %x",
3769 ms->m_header.h_nodeid, ms->m_remid);
3770 return;
3771 }
3772
3773 _receive_convert_reply(lkb, ms);
3774 dlm_put_lkb(lkb);
3775}
3776
3777static void _receive_unlock_reply(struct dlm_lkb *lkb, struct dlm_message *ms)
3778{
3779 struct dlm_rsb *r = lkb->lkb_resource;
3780 int error;
3781
3782 hold_rsb(r);
3783 lock_rsb(r);
3784
3785 error = validate_message(lkb, ms);
3786 if (error)
3787 goto out;
3788
3789 /* stub reply can happen with waiters_mutex held */
3790 error = remove_from_waiters_ms(lkb, ms);
3791 if (error)
3792 goto out;
3793
3794 /* this is the value returned from do_unlock() on the master */
3795
3796 switch (ms->m_result) {
3797 case -DLM_EUNLOCK:
3798 receive_flags_reply(lkb, ms);
3799 remove_lock_pc(r, lkb);
3800 queue_cast(r, lkb, -DLM_EUNLOCK);
3801 break;
3802 case -ENOENT:
3803 break;
3804 default:
3805 log_error(r->res_ls, "receive_unlock_reply %x error %d",
3806 lkb->lkb_id, ms->m_result);
3807 }
3808 out:
3809 unlock_rsb(r);
3810 put_rsb(r);
3811}
3812
3813static void receive_unlock_reply(struct dlm_ls *ls, struct dlm_message *ms)
3814{
3815 struct dlm_lkb *lkb;
3816 int error;
3817
3818 error = find_lkb(ls, ms->m_remid, &lkb);
3819 if (error) {
3820 log_debug(ls, "receive_unlock_reply from %d no lkb %x",
3821 ms->m_header.h_nodeid, ms->m_remid);
3822 return;
3823 }
3824
3825 _receive_unlock_reply(lkb, ms);
3826 dlm_put_lkb(lkb);
3827}
3828
3829static void _receive_cancel_reply(struct dlm_lkb *lkb, struct dlm_message *ms)
3830{
3831 struct dlm_rsb *r = lkb->lkb_resource;
3832 int error;
3833
3834 hold_rsb(r);
3835 lock_rsb(r);
3836
3837 error = validate_message(lkb, ms);
3838 if (error)
3839 goto out;
3840
3841 /* stub reply can happen with waiters_mutex held */
3842 error = remove_from_waiters_ms(lkb, ms);
3843 if (error)
3844 goto out;
3845
3846 /* this is the value returned from do_cancel() on the master */
3847
3848 switch (ms->m_result) {
3849 case -DLM_ECANCEL:
3850 receive_flags_reply(lkb, ms);
3851 revert_lock_pc(r, lkb);
3852 queue_cast(r, lkb, -DLM_ECANCEL);
3853 break;
3854 case 0:
3855 break;
3856 default:
3857 log_error(r->res_ls, "receive_cancel_reply %x error %d",
3858 lkb->lkb_id, ms->m_result);
3859 }
3860 out:
3861 unlock_rsb(r);
3862 put_rsb(r);
3863}
3864
3865static void receive_cancel_reply(struct dlm_ls *ls, struct dlm_message *ms)
3866{
3867 struct dlm_lkb *lkb;
3868 int error;
3869
3870 error = find_lkb(ls, ms->m_remid, &lkb);
3871 if (error) {
3872 log_debug(ls, "receive_cancel_reply from %d no lkb %x",
3873 ms->m_header.h_nodeid, ms->m_remid);
3874 return;
3875 }
3876
3877 _receive_cancel_reply(lkb, ms);
3878 dlm_put_lkb(lkb);
3879}
3880
3881static void receive_lookup_reply(struct dlm_ls *ls, struct dlm_message *ms)
3882{
3883 struct dlm_lkb *lkb;
3884 struct dlm_rsb *r;
3885 int error, ret_nodeid;
3886
3887 error = find_lkb(ls, ms->m_lkid, &lkb);
3888 if (error) {
3889 log_error(ls, "receive_lookup_reply no lkb");
3890 return;
3891 }
3892
3893 /* ms->m_result is the value returned by dlm_dir_lookup on dir node
3894 FIXME: will a non-zero error ever be returned? */
3895
3896 r = lkb->lkb_resource;
3897 hold_rsb(r);
3898 lock_rsb(r);
3899
3900 error = remove_from_waiters(lkb, DLM_MSG_LOOKUP_REPLY);
3901 if (error)
3902 goto out;
3903
3904 ret_nodeid = ms->m_nodeid;
3905 if (ret_nodeid == dlm_our_nodeid()) {
3906 r->res_nodeid = 0;
3907 ret_nodeid = 0;
3908 r->res_first_lkid = 0;
3909 } else {
3910 /* set_master() will copy res_nodeid to lkb_nodeid */
3911 r->res_nodeid = ret_nodeid;
3912 }
3913
3914 if (is_overlap(lkb)) {
3915 log_debug(ls, "receive_lookup_reply %x unlock %x",
3916 lkb->lkb_id, lkb->lkb_flags);
3917 queue_cast_overlap(r, lkb);
3918 unhold_lkb(lkb); /* undoes create_lkb() */
3919 goto out_list;
3920 }
3921
3922 _request_lock(r, lkb);
3923
3924 out_list:
3925 if (!ret_nodeid)
3926 process_lookup_list(r);
3927 out:
3928 unlock_rsb(r);
3929 put_rsb(r);
3930 dlm_put_lkb(lkb);
3931}
3932
3933static void _receive_message(struct dlm_ls *ls, struct dlm_message *ms)
3934{
3935 if (!dlm_is_member(ls, ms->m_header.h_nodeid)) {
3936 log_debug(ls, "ignore non-member message %d from %d %x %x %d",
3937 ms->m_type, ms->m_header.h_nodeid, ms->m_lkid,
3938 ms->m_remid, ms->m_result);
3939 return;
3940 }
3941
3942 switch (ms->m_type) {
3943
3944 /* messages sent to a master node */
3945
3946 case DLM_MSG_REQUEST:
3947 receive_request(ls, ms);
3948 break;
3949
3950 case DLM_MSG_CONVERT:
3951 receive_convert(ls, ms);
3952 break;
3953
3954 case DLM_MSG_UNLOCK:
3955 receive_unlock(ls, ms);
3956 break;
3957
3958 case DLM_MSG_CANCEL:
3959 receive_cancel(ls, ms);
3960 break;
3961
3962 /* messages sent from a master node (replies to above) */
3963
3964 case DLM_MSG_REQUEST_REPLY:
3965 receive_request_reply(ls, ms);
3966 break;
3967
3968 case DLM_MSG_CONVERT_REPLY:
3969 receive_convert_reply(ls, ms);
3970 break;
3971
3972 case DLM_MSG_UNLOCK_REPLY:
3973 receive_unlock_reply(ls, ms);
3974 break;
3975
3976 case DLM_MSG_CANCEL_REPLY:
3977 receive_cancel_reply(ls, ms);
3978 break;
3979
3980 /* messages sent from a master node (only two types of async msg) */
3981
3982 case DLM_MSG_GRANT:
3983 receive_grant(ls, ms);
3984 break;
3985
3986 case DLM_MSG_BAST:
3987 receive_bast(ls, ms);
3988 break;
3989
3990 /* messages sent to a dir node */
3991
3992 case DLM_MSG_LOOKUP:
3993 receive_lookup(ls, ms);
3994 break;
3995
3996 case DLM_MSG_REMOVE:
3997 receive_remove(ls, ms);
3998 break;
3999
4000 /* messages sent from a dir node (remove has no reply) */
4001
4002 case DLM_MSG_LOOKUP_REPLY:
4003 receive_lookup_reply(ls, ms);
4004 break;
4005
4006 /* other messages */
4007
4008 case DLM_MSG_PURGE:
4009 receive_purge(ls, ms);
4010 break;
4011
4012 default:
4013 log_error(ls, "unknown message type %d", ms->m_type);
4014 }
4015}
4016
4017/* If the lockspace is in recovery mode (locking stopped), then normal
4018 messages are saved on the requestqueue for processing after recovery is
4019 done. When not in recovery mode, we wait for dlm_recoverd to drain saved
4020 messages off the requestqueue before we process new ones. This occurs right
4021 after recovery completes when we transition from saving all messages on
4022 requestqueue, to processing all the saved messages, to processing new
4023 messages as they arrive. */
4024
4025static void dlm_receive_message(struct dlm_ls *ls, struct dlm_message *ms,
4026 int nodeid)
4027{
4028 if (dlm_locking_stopped(ls)) {
4029 dlm_add_requestqueue(ls, nodeid, ms);
4030 } else {
4031 dlm_wait_requestqueue(ls);
4032 _receive_message(ls, ms);
4033 }
4034}
4035
4036/* This is called by dlm_recoverd to process messages that were saved on
4037 the requestqueue. */
4038
4039void dlm_receive_message_saved(struct dlm_ls *ls, struct dlm_message *ms)
4040{
4041 _receive_message(ls, ms);
4042}
4043
4044/* This is called by the midcomms layer when something is received for
4045 the lockspace. It could be either a MSG (normal message sent as part of
4046 standard locking activity) or an RCOM (recovery message sent as part of
4047 lockspace recovery). */
4048
4049void dlm_receive_buffer(union dlm_packet *p, int nodeid)
4050{
4051 struct dlm_header *hd = &p->header;
4052 struct dlm_ls *ls;
4053 int type = 0;
4054
4055 switch (hd->h_cmd) {
4056 case DLM_MSG:
4057 dlm_message_in(&p->message);
4058 type = p->message.m_type;
4059 break;
4060 case DLM_RCOM:
4061 dlm_rcom_in(&p->rcom);
4062 type = p->rcom.rc_type;
4063 break;
4064 default:
4065 log_print("invalid h_cmd %d from %u", hd->h_cmd, nodeid);
4066 return;
4067 }
4068
4069 if (hd->h_nodeid != nodeid) {
4070 log_print("invalid h_nodeid %d from %d lockspace %x",
4071 hd->h_nodeid, nodeid, hd->h_lockspace);
4072 return;
4073 }
4074
4075 ls = dlm_find_lockspace_global(hd->h_lockspace);
4076 if (!ls) {
4077 if (dlm_config.ci_log_debug)
4078 log_print("invalid lockspace %x from %d cmd %d type %d",
4079 hd->h_lockspace, nodeid, hd->h_cmd, type);
4080
4081 if (hd->h_cmd == DLM_RCOM && type == DLM_RCOM_STATUS)
4082 dlm_send_ls_not_ready(nodeid, &p->rcom);
4083 return;
4084 }
4085
4086 /* this rwsem allows dlm_ls_stop() to wait for all dlm_recv threads to
4087 be inactive (in this ls) before transitioning to recovery mode */
4088
4089 down_read(&ls->ls_recv_active);
4090 if (hd->h_cmd == DLM_MSG)
4091 dlm_receive_message(ls, &p->message, nodeid);
4092 else
4093 dlm_receive_rcom(ls, &p->rcom, nodeid);
4094 up_read(&ls->ls_recv_active);
4095
4096 dlm_put_lockspace(ls);
4097}
4098
4099static void recover_convert_waiter(struct dlm_ls *ls, struct dlm_lkb *lkb,
4100 struct dlm_message *ms_stub)
4101{
4102 if (middle_conversion(lkb)) {
4103 hold_lkb(lkb);
4104 memset(ms_stub, 0, sizeof(struct dlm_message));
4105 ms_stub->m_flags = DLM_IFL_STUB_MS;
4106 ms_stub->m_type = DLM_MSG_CONVERT_REPLY;
4107 ms_stub->m_result = -EINPROGRESS;
4108 ms_stub->m_header.h_nodeid = lkb->lkb_nodeid;
4109 _receive_convert_reply(lkb, ms_stub);
4110
4111 /* Same special case as in receive_rcom_lock_args() */
4112 lkb->lkb_grmode = DLM_LOCK_IV;
4113 rsb_set_flag(lkb->lkb_resource, RSB_RECOVER_CONVERT);
4114 unhold_lkb(lkb);
4115
4116 } else if (lkb->lkb_rqmode >= lkb->lkb_grmode) {
4117 lkb->lkb_flags |= DLM_IFL_RESEND;
4118 }
4119
4120 /* lkb->lkb_rqmode < lkb->lkb_grmode shouldn't happen since down
4121 conversions are async; there's no reply from the remote master */
4122}
4123
4124/* A waiting lkb needs recovery if the master node has failed, or
4125 the master node is changing (only when no directory is used) */
4126
4127static int waiter_needs_recovery(struct dlm_ls *ls, struct dlm_lkb *lkb)
4128{
4129 if (dlm_is_removed(ls, lkb->lkb_nodeid))
4130 return 1;
4131
4132 if (!dlm_no_directory(ls))
4133 return 0;
4134
4135 if (dlm_dir_nodeid(lkb->lkb_resource) != lkb->lkb_nodeid)
4136 return 1;
4137
4138 return 0;
4139}
4140
4141/* Recovery for locks that are waiting for replies from nodes that are now
4142 gone. We can just complete unlocks and cancels by faking a reply from the
4143 dead node. Requests and up-conversions we flag to be resent after
4144 recovery. Down-conversions can just be completed with a fake reply like
4145 unlocks. Conversions between PR and CW need special attention. */
4146
4147void dlm_recover_waiters_pre(struct dlm_ls *ls)
4148{
4149 struct dlm_lkb *lkb, *safe;
4150 struct dlm_message *ms_stub;
4151 int wait_type, stub_unlock_result, stub_cancel_result;
4152
4153 ms_stub = kmalloc(sizeof(struct dlm_message), GFP_KERNEL);
4154 if (!ms_stub) {
4155 log_error(ls, "dlm_recover_waiters_pre no mem");
4156 return;
4157 }
4158
4159 mutex_lock(&ls->ls_waiters_mutex);
4160
4161 list_for_each_entry_safe(lkb, safe, &ls->ls_waiters, lkb_wait_reply) {
4162
4163 /* exclude debug messages about unlocks because there can be so
4164 many and they aren't very interesting */
4165
4166 if (lkb->lkb_wait_type != DLM_MSG_UNLOCK) {
4167 log_debug(ls, "recover_waiter %x nodeid %d "
4168 "msg %d to %d", lkb->lkb_id, lkb->lkb_nodeid,
4169 lkb->lkb_wait_type, lkb->lkb_wait_nodeid);
4170 }
4171
4172 /* all outstanding lookups, regardless of destination will be
4173 resent after recovery is done */
4174
4175 if (lkb->lkb_wait_type == DLM_MSG_LOOKUP) {
4176 lkb->lkb_flags |= DLM_IFL_RESEND;
4177 continue;
4178 }
4179
4180 if (!waiter_needs_recovery(ls, lkb))
4181 continue;
4182
4183 wait_type = lkb->lkb_wait_type;
4184 stub_unlock_result = -DLM_EUNLOCK;
4185 stub_cancel_result = -DLM_ECANCEL;
4186
4187 /* Main reply may have been received leaving a zero wait_type,
4188 but a reply for the overlapping op may not have been
4189 received. In that case we need to fake the appropriate
4190 reply for the overlap op. */
4191
4192 if (!wait_type) {
4193 if (is_overlap_cancel(lkb)) {
4194 wait_type = DLM_MSG_CANCEL;
4195 if (lkb->lkb_grmode == DLM_LOCK_IV)
4196 stub_cancel_result = 0;
4197 }
4198 if (is_overlap_unlock(lkb)) {
4199 wait_type = DLM_MSG_UNLOCK;
4200 if (lkb->lkb_grmode == DLM_LOCK_IV)
4201 stub_unlock_result = -ENOENT;
4202 }
4203
4204 log_debug(ls, "rwpre overlap %x %x %d %d %d",
4205 lkb->lkb_id, lkb->lkb_flags, wait_type,
4206 stub_cancel_result, stub_unlock_result);
4207 }
4208
4209 switch (wait_type) {
4210
4211 case DLM_MSG_REQUEST:
4212 lkb->lkb_flags |= DLM_IFL_RESEND;
4213 break;
4214
4215 case DLM_MSG_CONVERT:
4216 recover_convert_waiter(ls, lkb, ms_stub);
4217 break;
4218
4219 case DLM_MSG_UNLOCK:
4220 hold_lkb(lkb);
4221 memset(ms_stub, 0, sizeof(struct dlm_message));
4222 ms_stub->m_flags = DLM_IFL_STUB_MS;
4223 ms_stub->m_type = DLM_MSG_UNLOCK_REPLY;
4224 ms_stub->m_result = stub_unlock_result;
4225 ms_stub->m_header.h_nodeid = lkb->lkb_nodeid;
4226 _receive_unlock_reply(lkb, ms_stub);
4227 dlm_put_lkb(lkb);
4228 break;
4229
4230 case DLM_MSG_CANCEL:
4231 hold_lkb(lkb);
4232 memset(ms_stub, 0, sizeof(struct dlm_message));
4233 ms_stub->m_flags = DLM_IFL_STUB_MS;
4234 ms_stub->m_type = DLM_MSG_CANCEL_REPLY;
4235 ms_stub->m_result = stub_cancel_result;
4236 ms_stub->m_header.h_nodeid = lkb->lkb_nodeid;
4237 _receive_cancel_reply(lkb, ms_stub);
4238 dlm_put_lkb(lkb);
4239 break;
4240
4241 default:
4242 log_error(ls, "invalid lkb wait_type %d %d",
4243 lkb->lkb_wait_type, wait_type);
4244 }
4245 schedule();
4246 }
4247 mutex_unlock(&ls->ls_waiters_mutex);
4248 kfree(ms_stub);
4249}
4250
4251static struct dlm_lkb *find_resend_waiter(struct dlm_ls *ls)
4252{
4253 struct dlm_lkb *lkb;
4254 int found = 0;
4255
4256 mutex_lock(&ls->ls_waiters_mutex);
4257 list_for_each_entry(lkb, &ls->ls_waiters, lkb_wait_reply) {
4258 if (lkb->lkb_flags & DLM_IFL_RESEND) {
4259 hold_lkb(lkb);
4260 found = 1;
4261 break;
4262 }
4263 }
4264 mutex_unlock(&ls->ls_waiters_mutex);
4265
4266 if (!found)
4267 lkb = NULL;
4268 return lkb;
4269}
4270
4271/* Deal with lookups and lkb's marked RESEND from _pre. We may now be the
4272 master or dir-node for r. Processing the lkb may result in it being placed
4273 back on waiters. */
4274
4275/* We do this after normal locking has been enabled and any saved messages
4276 (in requestqueue) have been processed. We should be confident that at
4277 this point we won't get or process a reply to any of these waiting
4278 operations. But, new ops may be coming in on the rsbs/locks here from
4279 userspace or remotely. */
4280
4281/* there may have been an overlap unlock/cancel prior to recovery or after
4282 recovery. if before, the lkb may still have a pos wait_count; if after, the
4283 overlap flag would just have been set and nothing new sent. we can be
4284 confident here than any replies to either the initial op or overlap ops
4285 prior to recovery have been received. */
4286
4287int dlm_recover_waiters_post(struct dlm_ls *ls)
4288{
4289 struct dlm_lkb *lkb;
4290 struct dlm_rsb *r;
4291 int error = 0, mstype, err, oc, ou;
4292
4293 while (1) {
4294 if (dlm_locking_stopped(ls)) {
4295 log_debug(ls, "recover_waiters_post aborted");
4296 error = -EINTR;
4297 break;
4298 }
4299
4300 lkb = find_resend_waiter(ls);
4301 if (!lkb)
4302 break;
4303
4304 r = lkb->lkb_resource;
4305 hold_rsb(r);
4306 lock_rsb(r);
4307
4308 mstype = lkb->lkb_wait_type;
4309 oc = is_overlap_cancel(lkb);
4310 ou = is_overlap_unlock(lkb);
4311 err = 0;
4312
4313 log_debug(ls, "recover_waiter %x nodeid %d msg %d r_nodeid %d",
4314 lkb->lkb_id, lkb->lkb_nodeid, mstype, r->res_nodeid);
4315
4316 /* At this point we assume that we won't get a reply to any
4317 previous op or overlap op on this lock. First, do a big
4318 remove_from_waiters() for all previous ops. */
4319
4320 lkb->lkb_flags &= ~DLM_IFL_RESEND;
4321 lkb->lkb_flags &= ~DLM_IFL_OVERLAP_UNLOCK;
4322 lkb->lkb_flags &= ~DLM_IFL_OVERLAP_CANCEL;
4323 lkb->lkb_wait_type = 0;
4324 lkb->lkb_wait_count = 0;
4325 mutex_lock(&ls->ls_waiters_mutex);
4326 list_del_init(&lkb->lkb_wait_reply);
4327 mutex_unlock(&ls->ls_waiters_mutex);
4328 unhold_lkb(lkb); /* for waiters list */
4329
4330 if (oc || ou) {
4331 /* do an unlock or cancel instead of resending */
4332 switch (mstype) {
4333 case DLM_MSG_LOOKUP:
4334 case DLM_MSG_REQUEST:
4335 queue_cast(r, lkb, ou ? -DLM_EUNLOCK :
4336 -DLM_ECANCEL);
4337 unhold_lkb(lkb); /* undoes create_lkb() */
4338 break;
4339 case DLM_MSG_CONVERT:
4340 if (oc) {
4341 queue_cast(r, lkb, -DLM_ECANCEL);
4342 } else {
4343 lkb->lkb_exflags |= DLM_LKF_FORCEUNLOCK;
4344 _unlock_lock(r, lkb);
4345 }
4346 break;
4347 default:
4348 err = 1;
4349 }
4350 } else {
4351 switch (mstype) {
4352 case DLM_MSG_LOOKUP:
4353 case DLM_MSG_REQUEST:
4354 _request_lock(r, lkb);
4355 if (is_master(r))
4356 confirm_master(r, 0);
4357 break;
4358 case DLM_MSG_CONVERT:
4359 _convert_lock(r, lkb);
4360 break;
4361 default:
4362 err = 1;
4363 }
4364 }
4365
4366 if (err)
4367 log_error(ls, "recover_waiters_post %x %d %x %d %d",
4368 lkb->lkb_id, mstype, lkb->lkb_flags, oc, ou);
4369 unlock_rsb(r);
4370 put_rsb(r);
4371 dlm_put_lkb(lkb);
4372 }
4373
4374 return error;
4375}
4376
4377static void purge_queue(struct dlm_rsb *r, struct list_head *queue,
4378 int (*test)(struct dlm_ls *ls, struct dlm_lkb *lkb))
4379{
4380 struct dlm_ls *ls = r->res_ls;
4381 struct dlm_lkb *lkb, *safe;
4382
4383 list_for_each_entry_safe(lkb, safe, queue, lkb_statequeue) {
4384 if (test(ls, lkb)) {
4385 rsb_set_flag(r, RSB_LOCKS_PURGED);
4386 del_lkb(r, lkb);
4387 /* this put should free the lkb */
4388 if (!dlm_put_lkb(lkb))
4389 log_error(ls, "purged lkb not released");
4390 }
4391 }
4392}
4393
4394static int purge_dead_test(struct dlm_ls *ls, struct dlm_lkb *lkb)
4395{
4396 return (is_master_copy(lkb) && dlm_is_removed(ls, lkb->lkb_nodeid));
4397}
4398
4399static int purge_mstcpy_test(struct dlm_ls *ls, struct dlm_lkb *lkb)
4400{
4401 return is_master_copy(lkb);
4402}
4403
4404static void purge_dead_locks(struct dlm_rsb *r)
4405{
4406 purge_queue(r, &r->res_grantqueue, &purge_dead_test);
4407 purge_queue(r, &r->res_convertqueue, &purge_dead_test);
4408 purge_queue(r, &r->res_waitqueue, &purge_dead_test);
4409}
4410
4411void dlm_purge_mstcpy_locks(struct dlm_rsb *r)
4412{
4413 purge_queue(r, &r->res_grantqueue, &purge_mstcpy_test);
4414 purge_queue(r, &r->res_convertqueue, &purge_mstcpy_test);
4415 purge_queue(r, &r->res_waitqueue, &purge_mstcpy_test);
4416}
4417
4418/* Get rid of locks held by nodes that are gone. */
4419
4420int dlm_purge_locks(struct dlm_ls *ls)
4421{
4422 struct dlm_rsb *r;
4423
4424 log_debug(ls, "dlm_purge_locks");
4425
4426 down_write(&ls->ls_root_sem);
4427 list_for_each_entry(r, &ls->ls_root_list, res_root_list) {
4428 hold_rsb(r);
4429 lock_rsb(r);
4430 if (is_master(r))
4431 purge_dead_locks(r);
4432 unlock_rsb(r);
4433 unhold_rsb(r);
4434
4435 schedule();
4436 }
4437 up_write(&ls->ls_root_sem);
4438
4439 return 0;
4440}
4441
4442static struct dlm_rsb *find_purged_rsb(struct dlm_ls *ls, int bucket)
4443{
4444 struct dlm_rsb *r, *r_ret = NULL;
4445
4446 spin_lock(&ls->ls_rsbtbl[bucket].lock);
4447 list_for_each_entry(r, &ls->ls_rsbtbl[bucket].list, res_hashchain) {
4448 if (!rsb_flag(r, RSB_LOCKS_PURGED))
4449 continue;
4450 hold_rsb(r);
4451 rsb_clear_flag(r, RSB_LOCKS_PURGED);
4452 r_ret = r;
4453 break;
4454 }
4455 spin_unlock(&ls->ls_rsbtbl[bucket].lock);
4456 return r_ret;
4457}
4458
4459void dlm_grant_after_purge(struct dlm_ls *ls)
4460{
4461 struct dlm_rsb *r;
4462 int bucket = 0;
4463
4464 while (1) {
4465 r = find_purged_rsb(ls, bucket);
4466 if (!r) {
4467 if (bucket == ls->ls_rsbtbl_size - 1)
4468 break;
4469 bucket++;
4470 continue;
4471 }
4472 lock_rsb(r);
4473 if (is_master(r)) {
4474 grant_pending_locks(r);
4475 confirm_master(r, 0);
4476 }
4477 unlock_rsb(r);
4478 put_rsb(r);
4479 schedule();
4480 }
4481}
4482
4483static struct dlm_lkb *search_remid_list(struct list_head *head, int nodeid,
4484 uint32_t remid)
4485{
4486 struct dlm_lkb *lkb;
4487
4488 list_for_each_entry(lkb, head, lkb_statequeue) {
4489 if (lkb->lkb_nodeid == nodeid && lkb->lkb_remid == remid)
4490 return lkb;
4491 }
4492 return NULL;
4493}
4494
4495static struct dlm_lkb *search_remid(struct dlm_rsb *r, int nodeid,
4496 uint32_t remid)
4497{
4498 struct dlm_lkb *lkb;
4499
4500 lkb = search_remid_list(&r->res_grantqueue, nodeid, remid);
4501 if (lkb)
4502 return lkb;
4503 lkb = search_remid_list(&r->res_convertqueue, nodeid, remid);
4504 if (lkb)
4505 return lkb;
4506 lkb = search_remid_list(&r->res_waitqueue, nodeid, remid);
4507 if (lkb)
4508 return lkb;
4509 return NULL;
4510}
4511
4512/* needs at least dlm_rcom + rcom_lock */
4513static int receive_rcom_lock_args(struct dlm_ls *ls, struct dlm_lkb *lkb,
4514 struct dlm_rsb *r, struct dlm_rcom *rc)
4515{
4516 struct rcom_lock *rl = (struct rcom_lock *) rc->rc_buf;
4517
4518 lkb->lkb_nodeid = rc->rc_header.h_nodeid;
4519 lkb->lkb_ownpid = le32_to_cpu(rl->rl_ownpid);
4520 lkb->lkb_remid = le32_to_cpu(rl->rl_lkid);
4521 lkb->lkb_exflags = le32_to_cpu(rl->rl_exflags);
4522 lkb->lkb_flags = le32_to_cpu(rl->rl_flags) & 0x0000FFFF;
4523 lkb->lkb_flags |= DLM_IFL_MSTCPY;
4524 lkb->lkb_lvbseq = le32_to_cpu(rl->rl_lvbseq);
4525 lkb->lkb_rqmode = rl->rl_rqmode;
4526 lkb->lkb_grmode = rl->rl_grmode;
4527 /* don't set lkb_status because add_lkb wants to itself */
4528
4529 lkb->lkb_bastfn = (rl->rl_asts & DLM_CB_BAST) ? &fake_bastfn : NULL;
4530 lkb->lkb_astfn = (rl->rl_asts & DLM_CB_CAST) ? &fake_astfn : NULL;
4531
4532 if (lkb->lkb_exflags & DLM_LKF_VALBLK) {
4533 int lvblen = rc->rc_header.h_length - sizeof(struct dlm_rcom) -
4534 sizeof(struct rcom_lock);
4535 if (lvblen > ls->ls_lvblen)
4536 return -EINVAL;
4537 lkb->lkb_lvbptr = dlm_allocate_lvb(ls);
4538 if (!lkb->lkb_lvbptr)
4539 return -ENOMEM;
4540 memcpy(lkb->lkb_lvbptr, rl->rl_lvb, lvblen);
4541 }
4542
4543 /* Conversions between PR and CW (middle modes) need special handling.
4544 The real granted mode of these converting locks cannot be determined
4545 until all locks have been rebuilt on the rsb (recover_conversion) */
4546
4547 if (rl->rl_wait_type == cpu_to_le16(DLM_MSG_CONVERT) &&
4548 middle_conversion(lkb)) {
4549 rl->rl_status = DLM_LKSTS_CONVERT;
4550 lkb->lkb_grmode = DLM_LOCK_IV;
4551 rsb_set_flag(r, RSB_RECOVER_CONVERT);
4552 }
4553
4554 return 0;
4555}
4556
4557/* This lkb may have been recovered in a previous aborted recovery so we need
4558 to check if the rsb already has an lkb with the given remote nodeid/lkid.
4559 If so we just send back a standard reply. If not, we create a new lkb with
4560 the given values and send back our lkid. We send back our lkid by sending
4561 back the rcom_lock struct we got but with the remid field filled in. */
4562
4563/* needs at least dlm_rcom + rcom_lock */
4564int dlm_recover_master_copy(struct dlm_ls *ls, struct dlm_rcom *rc)
4565{
4566 struct rcom_lock *rl = (struct rcom_lock *) rc->rc_buf;
4567 struct dlm_rsb *r;
4568 struct dlm_lkb *lkb;
4569 int error;
4570
4571 if (rl->rl_parent_lkid) {
4572 error = -EOPNOTSUPP;
4573 goto out;
4574 }
4575
4576 error = find_rsb(ls, rl->rl_name, le16_to_cpu(rl->rl_namelen),
4577 R_MASTER, &r);
4578 if (error)
4579 goto out;
4580
4581 lock_rsb(r);
4582
4583 lkb = search_remid(r, rc->rc_header.h_nodeid, le32_to_cpu(rl->rl_lkid));
4584 if (lkb) {
4585 error = -EEXIST;
4586 goto out_remid;
4587 }
4588
4589 error = create_lkb(ls, &lkb);
4590 if (error)
4591 goto out_unlock;
4592
4593 error = receive_rcom_lock_args(ls, lkb, r, rc);
4594 if (error) {
4595 __put_lkb(ls, lkb);
4596 goto out_unlock;
4597 }
4598
4599 attach_lkb(r, lkb);
4600 add_lkb(r, lkb, rl->rl_status);
4601 error = 0;
4602
4603 out_remid:
4604 /* this is the new value returned to the lock holder for
4605 saving in its process-copy lkb */
4606 rl->rl_remid = cpu_to_le32(lkb->lkb_id);
4607
4608 out_unlock:
4609 unlock_rsb(r);
4610 put_rsb(r);
4611 out:
4612 if (error)
4613 log_debug(ls, "recover_master_copy %d %x", error,
4614 le32_to_cpu(rl->rl_lkid));
4615 rl->rl_result = cpu_to_le32(error);
4616 return error;
4617}
4618
4619/* needs at least dlm_rcom + rcom_lock */
4620int dlm_recover_process_copy(struct dlm_ls *ls, struct dlm_rcom *rc)
4621{
4622 struct rcom_lock *rl = (struct rcom_lock *) rc->rc_buf;
4623 struct dlm_rsb *r;
4624 struct dlm_lkb *lkb;
4625 int error;
4626
4627 error = find_lkb(ls, le32_to_cpu(rl->rl_lkid), &lkb);
4628 if (error) {
4629 log_error(ls, "recover_process_copy no lkid %x",
4630 le32_to_cpu(rl->rl_lkid));
4631 return error;
4632 }
4633
4634 DLM_ASSERT(is_process_copy(lkb), dlm_print_lkb(lkb););
4635
4636 error = le32_to_cpu(rl->rl_result);
4637
4638 r = lkb->lkb_resource;
4639 hold_rsb(r);
4640 lock_rsb(r);
4641
4642 switch (error) {
4643 case -EBADR:
4644 /* There's a chance the new master received our lock before
4645 dlm_recover_master_reply(), this wouldn't happen if we did
4646 a barrier between recover_masters and recover_locks. */
4647 log_debug(ls, "master copy not ready %x r %lx %s", lkb->lkb_id,
4648 (unsigned long)r, r->res_name);
4649 dlm_send_rcom_lock(r, lkb);
4650 goto out;
4651 case -EEXIST:
4652 log_debug(ls, "master copy exists %x", lkb->lkb_id);
4653 /* fall through */
4654 case 0:
4655 lkb->lkb_remid = le32_to_cpu(rl->rl_remid);
4656 break;
4657 default:
4658 log_error(ls, "dlm_recover_process_copy unknown error %d %x",
4659 error, lkb->lkb_id);
4660 }
4661
4662 /* an ack for dlm_recover_locks() which waits for replies from
4663 all the locks it sends to new masters */
4664 dlm_recovered_lock(r);
4665 out:
4666 unlock_rsb(r);
4667 put_rsb(r);
4668 dlm_put_lkb(lkb);
4669
4670 return 0;
4671}
4672
4673int dlm_user_request(struct dlm_ls *ls, struct dlm_user_args *ua,
4674 int mode, uint32_t flags, void *name, unsigned int namelen,
4675 unsigned long timeout_cs)
4676{
4677 struct dlm_lkb *lkb;
4678 struct dlm_args args;
4679 int error;
4680
4681 dlm_lock_recovery(ls);
4682
4683 error = create_lkb(ls, &lkb);
4684 if (error) {
4685 kfree(ua);
4686 goto out;
4687 }
4688
4689 if (flags & DLM_LKF_VALBLK) {
4690 ua->lksb.sb_lvbptr = kzalloc(DLM_USER_LVB_LEN, GFP_NOFS);
4691 if (!ua->lksb.sb_lvbptr) {
4692 kfree(ua);
4693 __put_lkb(ls, lkb);
4694 error = -ENOMEM;
4695 goto out;
4696 }
4697 }
4698
4699 /* After ua is attached to lkb it will be freed by dlm_free_lkb().
4700 When DLM_IFL_USER is set, the dlm knows that this is a userspace
4701 lock and that lkb_astparam is the dlm_user_args structure. */
4702
4703 error = set_lock_args(mode, &ua->lksb, flags, namelen, timeout_cs,
4704 fake_astfn, ua, fake_bastfn, &args);
4705 lkb->lkb_flags |= DLM_IFL_USER;
4706
4707 if (error) {
4708 __put_lkb(ls, lkb);
4709 goto out;
4710 }
4711
4712 error = request_lock(ls, lkb, name, namelen, &args);
4713
4714 switch (error) {
4715 case 0:
4716 break;
4717 case -EINPROGRESS:
4718 error = 0;
4719 break;
4720 case -EAGAIN:
4721 error = 0;
4722 /* fall through */
4723 default:
4724 __put_lkb(ls, lkb);
4725 goto out;
4726 }
4727
4728 /* add this new lkb to the per-process list of locks */
4729 spin_lock(&ua->proc->locks_spin);
4730 hold_lkb(lkb);
4731 list_add_tail(&lkb->lkb_ownqueue, &ua->proc->locks);
4732 spin_unlock(&ua->proc->locks_spin);
4733 out:
4734 dlm_unlock_recovery(ls);
4735 return error;
4736}
4737
4738int dlm_user_convert(struct dlm_ls *ls, struct dlm_user_args *ua_tmp,
4739 int mode, uint32_t flags, uint32_t lkid, char *lvb_in,
4740 unsigned long timeout_cs)
4741{
4742 struct dlm_lkb *lkb;
4743 struct dlm_args args;
4744 struct dlm_user_args *ua;
4745 int error;
4746
4747 dlm_lock_recovery(ls);
4748
4749 error = find_lkb(ls, lkid, &lkb);
4750 if (error)
4751 goto out;
4752
4753 /* user can change the params on its lock when it converts it, or
4754 add an lvb that didn't exist before */
4755
4756 ua = lkb->lkb_ua;
4757
4758 if (flags & DLM_LKF_VALBLK && !ua->lksb.sb_lvbptr) {
4759 ua->lksb.sb_lvbptr = kzalloc(DLM_USER_LVB_LEN, GFP_NOFS);
4760 if (!ua->lksb.sb_lvbptr) {
4761 error = -ENOMEM;
4762 goto out_put;
4763 }
4764 }
4765 if (lvb_in && ua->lksb.sb_lvbptr)
4766 memcpy(ua->lksb.sb_lvbptr, lvb_in, DLM_USER_LVB_LEN);
4767
4768 ua->xid = ua_tmp->xid;
4769 ua->castparam = ua_tmp->castparam;
4770 ua->castaddr = ua_tmp->castaddr;
4771 ua->bastparam = ua_tmp->bastparam;
4772 ua->bastaddr = ua_tmp->bastaddr;
4773 ua->user_lksb = ua_tmp->user_lksb;
4774
4775 error = set_lock_args(mode, &ua->lksb, flags, 0, timeout_cs,
4776 fake_astfn, ua, fake_bastfn, &args);
4777 if (error)
4778 goto out_put;
4779
4780 error = convert_lock(ls, lkb, &args);
4781
4782 if (error == -EINPROGRESS || error == -EAGAIN || error == -EDEADLK)
4783 error = 0;
4784 out_put:
4785 dlm_put_lkb(lkb);
4786 out:
4787 dlm_unlock_recovery(ls);
4788 kfree(ua_tmp);
4789 return error;
4790}
4791
4792int dlm_user_unlock(struct dlm_ls *ls, struct dlm_user_args *ua_tmp,
4793 uint32_t flags, uint32_t lkid, char *lvb_in)
4794{
4795 struct dlm_lkb *lkb;
4796 struct dlm_args args;
4797 struct dlm_user_args *ua;
4798 int error;
4799
4800 dlm_lock_recovery(ls);
4801
4802 error = find_lkb(ls, lkid, &lkb);
4803 if (error)
4804 goto out;
4805
4806 ua = lkb->lkb_ua;
4807
4808 if (lvb_in && ua->lksb.sb_lvbptr)
4809 memcpy(ua->lksb.sb_lvbptr, lvb_in, DLM_USER_LVB_LEN);
4810 if (ua_tmp->castparam)
4811 ua->castparam = ua_tmp->castparam;
4812 ua->user_lksb = ua_tmp->user_lksb;
4813
4814 error = set_unlock_args(flags, ua, &args);
4815 if (error)
4816 goto out_put;
4817
4818 error = unlock_lock(ls, lkb, &args);
4819
4820 if (error == -DLM_EUNLOCK)
4821 error = 0;
4822 /* from validate_unlock_args() */
4823 if (error == -EBUSY && (flags & DLM_LKF_FORCEUNLOCK))
4824 error = 0;
4825 if (error)
4826 goto out_put;
4827
4828 spin_lock(&ua->proc->locks_spin);
4829 /* dlm_user_add_cb() may have already taken lkb off the proc list */
4830 if (!list_empty(&lkb->lkb_ownqueue))
4831 list_move(&lkb->lkb_ownqueue, &ua->proc->unlocking);
4832 spin_unlock(&ua->proc->locks_spin);
4833 out_put:
4834 dlm_put_lkb(lkb);
4835 out:
4836 dlm_unlock_recovery(ls);
4837 kfree(ua_tmp);
4838 return error;
4839}
4840
4841int dlm_user_cancel(struct dlm_ls *ls, struct dlm_user_args *ua_tmp,
4842 uint32_t flags, uint32_t lkid)
4843{
4844 struct dlm_lkb *lkb;
4845 struct dlm_args args;
4846 struct dlm_user_args *ua;
4847 int error;
4848
4849 dlm_lock_recovery(ls);
4850
4851 error = find_lkb(ls, lkid, &lkb);
4852 if (error)
4853 goto out;
4854
4855 ua = lkb->lkb_ua;
4856 if (ua_tmp->castparam)
4857 ua->castparam = ua_tmp->castparam;
4858 ua->user_lksb = ua_tmp->user_lksb;
4859
4860 error = set_unlock_args(flags, ua, &args);
4861 if (error)
4862 goto out_put;
4863
4864 error = cancel_lock(ls, lkb, &args);
4865
4866 if (error == -DLM_ECANCEL)
4867 error = 0;
4868 /* from validate_unlock_args() */
4869 if (error == -EBUSY)
4870 error = 0;
4871 out_put:
4872 dlm_put_lkb(lkb);
4873 out:
4874 dlm_unlock_recovery(ls);
4875 kfree(ua_tmp);
4876 return error;
4877}
4878
4879int dlm_user_deadlock(struct dlm_ls *ls, uint32_t flags, uint32_t lkid)
4880{
4881 struct dlm_lkb *lkb;
4882 struct dlm_args args;
4883 struct dlm_user_args *ua;
4884 struct dlm_rsb *r;
4885 int error;
4886
4887 dlm_lock_recovery(ls);
4888
4889 error = find_lkb(ls, lkid, &lkb);
4890 if (error)
4891 goto out;
4892
4893 ua = lkb->lkb_ua;
4894
4895 error = set_unlock_args(flags, ua, &args);
4896 if (error)
4897 goto out_put;
4898
4899 /* same as cancel_lock(), but set DEADLOCK_CANCEL after lock_rsb */
4900
4901 r = lkb->lkb_resource;
4902 hold_rsb(r);
4903 lock_rsb(r);
4904
4905 error = validate_unlock_args(lkb, &args);
4906 if (error)
4907 goto out_r;
4908 lkb->lkb_flags |= DLM_IFL_DEADLOCK_CANCEL;
4909
4910 error = _cancel_lock(r, lkb);
4911 out_r:
4912 unlock_rsb(r);
4913 put_rsb(r);
4914
4915 if (error == -DLM_ECANCEL)
4916 error = 0;
4917 /* from validate_unlock_args() */
4918 if (error == -EBUSY)
4919 error = 0;
4920 out_put:
4921 dlm_put_lkb(lkb);
4922 out:
4923 dlm_unlock_recovery(ls);
4924 return error;
4925}
4926
4927/* lkb's that are removed from the waiters list by revert are just left on the
4928 orphans list with the granted orphan locks, to be freed by purge */
4929
4930static int orphan_proc_lock(struct dlm_ls *ls, struct dlm_lkb *lkb)
4931{
4932 struct dlm_args args;
4933 int error;
4934
4935 hold_lkb(lkb);
4936 mutex_lock(&ls->ls_orphans_mutex);
4937 list_add_tail(&lkb->lkb_ownqueue, &ls->ls_orphans);
4938 mutex_unlock(&ls->ls_orphans_mutex);
4939
4940 set_unlock_args(0, lkb->lkb_ua, &args);
4941
4942 error = cancel_lock(ls, lkb, &args);
4943 if (error == -DLM_ECANCEL)
4944 error = 0;
4945 return error;
4946}
4947
4948/* The force flag allows the unlock to go ahead even if the lkb isn't granted.
4949 Regardless of what rsb queue the lock is on, it's removed and freed. */
4950
4951static int unlock_proc_lock(struct dlm_ls *ls, struct dlm_lkb *lkb)
4952{
4953 struct dlm_args args;
4954 int error;
4955
4956 set_unlock_args(DLM_LKF_FORCEUNLOCK, lkb->lkb_ua, &args);
4957
4958 error = unlock_lock(ls, lkb, &args);
4959 if (error == -DLM_EUNLOCK)
4960 error = 0;
4961 return error;
4962}
4963
4964/* We have to release clear_proc_locks mutex before calling unlock_proc_lock()
4965 (which does lock_rsb) due to deadlock with receiving a message that does
4966 lock_rsb followed by dlm_user_add_cb() */
4967
4968static struct dlm_lkb *del_proc_lock(struct dlm_ls *ls,
4969 struct dlm_user_proc *proc)
4970{
4971 struct dlm_lkb *lkb = NULL;
4972
4973 mutex_lock(&ls->ls_clear_proc_locks);
4974 if (list_empty(&proc->locks))
4975 goto out;
4976
4977 lkb = list_entry(proc->locks.next, struct dlm_lkb, lkb_ownqueue);
4978 list_del_init(&lkb->lkb_ownqueue);
4979
4980 if (lkb->lkb_exflags & DLM_LKF_PERSISTENT)
4981 lkb->lkb_flags |= DLM_IFL_ORPHAN;
4982 else
4983 lkb->lkb_flags |= DLM_IFL_DEAD;
4984 out:
4985 mutex_unlock(&ls->ls_clear_proc_locks);
4986 return lkb;
4987}
4988
4989/* The ls_clear_proc_locks mutex protects against dlm_user_add_cb() which
4990 1) references lkb->ua which we free here and 2) adds lkbs to proc->asts,
4991 which we clear here. */
4992
4993/* proc CLOSING flag is set so no more device_reads should look at proc->asts
4994 list, and no more device_writes should add lkb's to proc->locks list; so we
4995 shouldn't need to take asts_spin or locks_spin here. this assumes that
4996 device reads/writes/closes are serialized -- FIXME: we may need to serialize
4997 them ourself. */
4998
4999void dlm_clear_proc_locks(struct dlm_ls *ls, struct dlm_user_proc *proc)
5000{
5001 struct dlm_lkb *lkb, *safe;
5002
5003 dlm_lock_recovery(ls);
5004
5005 while (1) {
5006 lkb = del_proc_lock(ls, proc);
5007 if (!lkb)
5008 break;
5009 del_timeout(lkb);
5010 if (lkb->lkb_exflags & DLM_LKF_PERSISTENT)
5011 orphan_proc_lock(ls, lkb);
5012 else
5013 unlock_proc_lock(ls, lkb);
5014
5015 /* this removes the reference for the proc->locks list
5016 added by dlm_user_request, it may result in the lkb
5017 being freed */
5018
5019 dlm_put_lkb(lkb);
5020 }
5021
5022 mutex_lock(&ls->ls_clear_proc_locks);
5023
5024 /* in-progress unlocks */
5025 list_for_each_entry_safe(lkb, safe, &proc->unlocking, lkb_ownqueue) {
5026 list_del_init(&lkb->lkb_ownqueue);
5027 lkb->lkb_flags |= DLM_IFL_DEAD;
5028 dlm_put_lkb(lkb);
5029 }
5030
5031 list_for_each_entry_safe(lkb, safe, &proc->asts, lkb_cb_list) {
5032 memset(&lkb->lkb_callbacks, 0,
5033 sizeof(struct dlm_callback) * DLM_CALLBACKS_SIZE);
5034 list_del_init(&lkb->lkb_cb_list);
5035 dlm_put_lkb(lkb);
5036 }
5037
5038 mutex_unlock(&ls->ls_clear_proc_locks);
5039 dlm_unlock_recovery(ls);
5040}
5041
5042static void purge_proc_locks(struct dlm_ls *ls, struct dlm_user_proc *proc)
5043{
5044 struct dlm_lkb *lkb, *safe;
5045
5046 while (1) {
5047 lkb = NULL;
5048 spin_lock(&proc->locks_spin);
5049 if (!list_empty(&proc->locks)) {
5050 lkb = list_entry(proc->locks.next, struct dlm_lkb,
5051 lkb_ownqueue);
5052 list_del_init(&lkb->lkb_ownqueue);
5053 }
5054 spin_unlock(&proc->locks_spin);
5055
5056 if (!lkb)
5057 break;
5058
5059 lkb->lkb_flags |= DLM_IFL_DEAD;
5060 unlock_proc_lock(ls, lkb);
5061 dlm_put_lkb(lkb); /* ref from proc->locks list */
5062 }
5063
5064 spin_lock(&proc->locks_spin);
5065 list_for_each_entry_safe(lkb, safe, &proc->unlocking, lkb_ownqueue) {
5066 list_del_init(&lkb->lkb_ownqueue);
5067 lkb->lkb_flags |= DLM_IFL_DEAD;
5068 dlm_put_lkb(lkb);
5069 }
5070 spin_unlock(&proc->locks_spin);
5071
5072 spin_lock(&proc->asts_spin);
5073 list_for_each_entry_safe(lkb, safe, &proc->asts, lkb_cb_list) {
5074 memset(&lkb->lkb_callbacks, 0,
5075 sizeof(struct dlm_callback) * DLM_CALLBACKS_SIZE);
5076 list_del_init(&lkb->lkb_cb_list);
5077 dlm_put_lkb(lkb);
5078 }
5079 spin_unlock(&proc->asts_spin);
5080}
5081
5082/* pid of 0 means purge all orphans */
5083
5084static void do_purge(struct dlm_ls *ls, int nodeid, int pid)
5085{
5086 struct dlm_lkb *lkb, *safe;
5087
5088 mutex_lock(&ls->ls_orphans_mutex);
5089 list_for_each_entry_safe(lkb, safe, &ls->ls_orphans, lkb_ownqueue) {
5090 if (pid && lkb->lkb_ownpid != pid)
5091 continue;
5092 unlock_proc_lock(ls, lkb);
5093 list_del_init(&lkb->lkb_ownqueue);
5094 dlm_put_lkb(lkb);
5095 }
5096 mutex_unlock(&ls->ls_orphans_mutex);
5097}
5098
5099static int send_purge(struct dlm_ls *ls, int nodeid, int pid)
5100{
5101 struct dlm_message *ms;
5102 struct dlm_mhandle *mh;
5103 int error;
5104
5105 error = _create_message(ls, sizeof(struct dlm_message), nodeid,
5106 DLM_MSG_PURGE, &ms, &mh);
5107 if (error)
5108 return error;
5109 ms->m_nodeid = nodeid;
5110 ms->m_pid = pid;
5111
5112 return send_message(mh, ms);
5113}
5114
5115int dlm_user_purge(struct dlm_ls *ls, struct dlm_user_proc *proc,
5116 int nodeid, int pid)
5117{
5118 int error = 0;
5119
5120 if (nodeid != dlm_our_nodeid()) {
5121 error = send_purge(ls, nodeid, pid);
5122 } else {
5123 dlm_lock_recovery(ls);
5124 if (pid == current->pid)
5125 purge_proc_locks(ls, proc);
5126 else
5127 do_purge(ls, nodeid, pid);
5128 dlm_unlock_recovery(ls);
5129 }
5130 return error;
5131}
5132