summaryrefslogtreecommitdiffstats
path: root/sys/nlm/nlm_advlock.c
blob: a2c62f04c113467ef040b4e37f4675375bde0c65 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
/*-
 * Copyright (c) 2008 Isilon Inc http://www.isilon.com/
 * Authors: Doug Rabson <dfr@rabson.org>
 * Developed with Red Inc: Alfred Perlstein <alfred@freebsd.org>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

#include <sys/param.h>
#include <sys/fcntl.h>
#include <sys/kernel.h>
#include <sys/limits.h>
#include <sys/lock.h>
#include <sys/lockf.h>
#include <sys/malloc.h>
#include <sys/mount.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/syslog.h>
#include <sys/systm.h>
#include <sys/unistd.h>
#include <sys/vimage.h>
#include <sys/vnode.h>

#include <rpc/rpcclnt.h>
#include <nfs/nfsproto.h>
#include <nfsclient/nfs.h>
#include <nfsclient/nfsnode.h>
#include <nfsclient/nfsmount.h>

#include <nlm/nlm_prot.h>
#include <nlm/nlm.h>

/*
 * We need to keep track of the svid values used for F_FLOCK locks.
 */
struct nlm_file_svid {
	int		ns_refs;	/* thread count + 1 if active */
	int		ns_svid;	/* on-the-wire SVID for this file */
	struct ucred	*ns_ucred;	/* creds to use for lock recovery */
	void		*ns_id;		/* local struct file pointer */
	bool_t		ns_active;	/* TRUE if we own a lock */
	LIST_ENTRY(nlm_file_svid) ns_link;
};
LIST_HEAD(nlm_file_svid_list, nlm_file_svid);

#define NLM_SVID_HASH_SIZE	256
struct nlm_file_svid_list nlm_file_svids[NLM_SVID_HASH_SIZE];

struct mtx nlm_svid_lock;
static struct unrhdr *nlm_svid_allocator;
static volatile u_int nlm_xid = 1;

static int nlm_setlock(struct nlm_host *host, struct rpc_callextra *ext,
    rpcvers_t vers, struct timeval *timo, int retries,
    struct vnode *vp, int op, struct flock *fl, int flags,
    int svid, size_t fhlen, void *fh, off_t size, bool_t reclaim);
static int nlm_clearlock(struct nlm_host *host,  struct rpc_callextra *ext,
    rpcvers_t vers, struct timeval *timo, int retries,
    struct vnode *vp, int op, struct flock *fl, int flags,
    int svid, size_t fhlen, void *fh, off_t size);
static int nlm_getlock(struct nlm_host *host, struct rpc_callextra *ext,
    rpcvers_t vers, struct timeval *timo, int retries,
    struct vnode *vp, int op, struct flock *fl, int flags,
    int svid, size_t fhlen, void *fh, off_t size);
static int nlm_map_status(nlm4_stats stat);
static struct nlm_file_svid *nlm_find_svid(void *id);
static void nlm_free_svid(struct nlm_file_svid *nf);
static int nlm_init_lock(struct flock *fl, int flags, int svid,
    rpcvers_t vers, size_t fhlen, void *fh, off_t size,
    struct nlm4_lock *lock, char oh_space[32]);

static void
nlm_client_init(void *dummy)
{
	int i;

	mtx_init(&nlm_svid_lock, "NLM svid lock", NULL, MTX_DEF);
	nlm_svid_allocator = new_unrhdr(PID_MAX + 2, INT_MAX, &nlm_svid_lock);
	for (i = 0; i < NLM_SVID_HASH_SIZE; i++)
		LIST_INIT(&nlm_file_svids[i]);
}
SYSINIT(nlm_client_init, SI_SUB_LOCK, SI_ORDER_FIRST, nlm_client_init, NULL);

static int
nlm_msg(struct thread *td, const char *server, const char *msg, int error)
{
	struct proc *p;

	p = td ? td->td_proc : NULL;
	if (error) {
		tprintf(p, LOG_INFO, "nfs server %s: %s, error %d\n", server,
		    msg, error);
	} else {
		tprintf(p, LOG_INFO, "nfs server %s: %s\n", server, msg);
	}
	return (0);
}

struct nlm_feedback_arg {
	bool_t	nf_printed;
	struct nfsmount *nf_nmp;
};

static void
nlm_down(struct nlm_feedback_arg *nf, struct thread *td,
    const char *msg, int error)
{
	struct nfsmount *nmp = nf->nf_nmp;

	if (nmp == NULL)
		return;
	mtx_lock(&nmp->nm_mtx);
	if (!(nmp->nm_state & NFSSTA_LOCKTIMEO)) {
		nmp->nm_state |= NFSSTA_LOCKTIMEO;
		mtx_unlock(&nmp->nm_mtx);
		vfs_event_signal(&nmp->nm_mountp->mnt_stat.f_fsid,
		    VQ_NOTRESPLOCK, 0);
	} else {
		mtx_unlock(&nmp->nm_mtx);
	}

	nf->nf_printed = TRUE;
	nlm_msg(td, nmp->nm_mountp->mnt_stat.f_mntfromname, msg, error);
}

static void
nlm_up(struct nlm_feedback_arg *nf, struct thread *td,
    const char *msg)
{
	struct nfsmount *nmp = nf->nf_nmp;

	if (!nf->nf_printed)
		return;

	nlm_msg(td, nmp->nm_mountp->mnt_stat.f_mntfromname, msg, 0);

	mtx_lock(&nmp->nm_mtx);
	if (nmp->nm_state & NFSSTA_LOCKTIMEO) {
		nmp->nm_state &= ~NFSSTA_LOCKTIMEO;
		mtx_unlock(&nmp->nm_mtx);
		vfs_event_signal(&nmp->nm_mountp->mnt_stat.f_fsid,
		    VQ_NOTRESPLOCK, 1);
	} else {
		mtx_unlock(&nmp->nm_mtx);
	}
}

static void
nlm_feedback(int type, int proc, void *arg)
{
	struct thread *td = curthread;
	struct nlm_feedback_arg *nf = (struct nlm_feedback_arg *) arg;

	switch (type) {
	case FEEDBACK_REXMIT2:
	case FEEDBACK_RECONNECT:
		nlm_down(nf, td, "lockd not responding", 0);
		break;

	case FEEDBACK_OK:
		nlm_up(nf, td, "lockd is alive again");
		break;
	}
}

/*
 * nlm_advlock --
 *      NFS advisory byte-level locks.
 */
static int
nlm_advlock_internal(struct vnode *vp, void *id, int op, struct flock *fl,
    int flags, bool_t reclaim, bool_t unlock_vp)
{
	struct thread *td = curthread;
	struct nfsmount *nmp;
	struct nfsnode *np;
	off_t size;
	size_t fhlen;
	union nfsfh fh;
	struct sockaddr *sa;
	struct sockaddr_storage ss;
	char servername[MNAMELEN];
	struct timeval timo;
	int retries;
	rpcvers_t vers;
	struct nlm_host *host;
	struct rpc_callextra ext;
	struct nlm_feedback_arg nf;
	AUTH *auth;
	struct ucred *cred;
	struct nlm_file_svid *ns;
	int svid;
	int error;

	ASSERT_VOP_LOCKED(vp, "nlm_advlock_1");

	/*
	 * Push any pending writes to the server and flush our cache
	 * so that if we are contending with another machine for a
	 * file, we get whatever they wrote and vice-versa.
	 */
	if (op == F_SETLK || op == F_UNLCK)
		nfs_vinvalbuf(vp, V_SAVE, td, 1);

	np = VTONFS(vp);
	nmp = VFSTONFS(vp->v_mount);
	size = np->n_size;
	sa = nmp->nm_nam;
	memcpy(&ss, sa, sa->sa_len);
	sa = (struct sockaddr *) &ss;
	mtx_lock(&hostname_mtx);
	strcpy(servername, nmp->nm_hostname);
	mtx_unlock(&hostname_mtx);
	fhlen = np->n_fhsize;
	memcpy(&fh.fh_bytes, np->n_fhp, fhlen);
	timo.tv_sec = nmp->nm_timeo / NFS_HZ;
	timo.tv_usec = (nmp->nm_timeo % NFS_HZ) * (1000000 / NFS_HZ);
	if (NFS_ISV3(vp))
		vers = NLM_VERS4;
	else
		vers = NLM_VERS;

	if (nmp->nm_flag & NFSMNT_SOFT)
		retries = nmp->nm_retry;
	else
		retries = INT_MAX;

	if (unlock_vp)
		VOP_UNLOCK(vp, 0);

	/*
	 * We need to switch to mount-point creds so that we can send
	 * packets from a privileged port.
	 */
	cred = td->td_ucred;
	td->td_ucred = vp->v_mount->mnt_cred;

	host = nlm_find_host_by_name(servername, sa, vers);
	auth = authunix_create(cred);
	memset(&ext, 0, sizeof(ext));

	nf.nf_printed = FALSE;
	nf.nf_nmp = nmp;
	ext.rc_auth = auth;

	ext.rc_feedback = nlm_feedback;
	ext.rc_feedback_arg = &nf;
	ext.rc_timers = NULL;

	ns = NULL;
	if (flags & F_FLOCK) {
		ns = nlm_find_svid(id);
		KASSERT(fl->l_start == 0 && fl->l_len == 0,
		    ("F_FLOCK lock requests must be whole-file locks"));
		if (!ns->ns_ucred) {
			/*
			 * Remember the creds used for locking in case
			 * we need to recover the lock later.
			 */
			ns->ns_ucred = crdup(cred);
		}
		svid = ns->ns_svid;
	} else if (flags & F_REMOTE) {
		/*
		 * If we are recovering after a server restart or
		 * trashing locks on a force unmount, use the same
		 * svid as last time.
		 */
		svid = fl->l_pid;
	} else {
		svid = ((struct proc *) id)->p_pid;
	}

	switch(op) {
	case F_SETLK:
		if ((flags & (F_FLOCK|F_WAIT)) == (F_FLOCK|F_WAIT)
		    && fl->l_type == F_WRLCK) {
			/*
			 * The semantics for flock(2) require that any
			 * shared lock on the file must be released
			 * before an exclusive lock is granted. The
			 * local locking code interprets this by
			 * unlocking the file before sleeping on a
			 * blocked exclusive lock request. We
			 * approximate this by first attempting
			 * non-blocking and if that fails, we unlock
			 * the file and block.
			 */
			error = nlm_setlock(host, &ext, vers, &timo, retries,
			    vp, F_SETLK, fl, flags & ~F_WAIT,
			    svid, fhlen, &fh.fh_bytes, size, reclaim);
			if (error == EAGAIN) {
				fl->l_type = F_UNLCK;
				error = nlm_clearlock(host, &ext, vers, &timo,
				    retries, vp, F_UNLCK, fl, flags,
				    svid, fhlen, &fh.fh_bytes, size);
				fl->l_type = F_WRLCK;
				if (!error) {
					mtx_lock(&nlm_svid_lock);
					if (ns->ns_active) {
						ns->ns_refs--;
						ns->ns_active = FALSE;
					}
					mtx_unlock(&nlm_svid_lock);
					flags |= F_WAIT;
					error = nlm_setlock(host, &ext, vers,
					    &timo, retries, vp, F_SETLK, fl,
					    flags, svid, fhlen, &fh.fh_bytes,
					    size, reclaim);
				}
			}
		} else {
			error = nlm_setlock(host, &ext, vers, &timo, retries,
			    vp, op, fl, flags, svid, fhlen, &fh.fh_bytes,
			    size, reclaim);
		}
		if (!error && ns) {
			mtx_lock(&nlm_svid_lock);
			if (!ns->ns_active) {
				/*
				 * Add one to the reference count to
				 * hold onto the SVID for the lifetime
				 * of the lock. Note that since
				 * F_FLOCK only supports whole-file
				 * locks, there can only be one active
				 * lock for this SVID.
				 */
				ns->ns_refs++;
				ns->ns_active = TRUE;
			}
			mtx_unlock(&nlm_svid_lock);
		}
		break;

	case F_UNLCK:
		error = nlm_clearlock(host, &ext, vers, &timo, retries,
		    vp, op, fl, flags, svid, fhlen, &fh.fh_bytes, size);
		if (!error && ns) {
			mtx_lock(&nlm_svid_lock);
			if (ns->ns_active) {
				ns->ns_refs--;
				ns->ns_active = FALSE;
			}
			mtx_unlock(&nlm_svid_lock);
		}
		break;

	case F_GETLK:
		error = nlm_getlock(host, &ext, vers, &timo, retries,
		    vp, op, fl, flags, svid, fhlen, &fh.fh_bytes, size);
		break;

	default:
		error = EINVAL;
		break;
	}

	if (ns)
		nlm_free_svid(ns);

	td->td_ucred = cred;
	AUTH_DESTROY(auth);

	nlm_host_release(host);

	return (error);
}

int
nlm_advlock(struct vop_advlock_args *ap)
{

	return (nlm_advlock_internal(ap->a_vp, ap->a_id, ap->a_op, ap->a_fl,
		ap->a_flags, FALSE, TRUE));
}

/*
 * Set the creds of td to the creds of the given lock's owner. The new
 * creds reference count will be incremented via crhold. The caller is
 * responsible for calling crfree and restoring td's original creds.
 */
static void
nlm_set_creds_for_lock(struct thread *td, struct flock *fl)
{
	int i;
	struct nlm_file_svid *ns;
	struct proc *p;
	struct ucred *cred;

	cred = NULL;
	if (fl->l_pid > PID_MAX) {
		/*
		 * If this was originally a F_FLOCK-style lock, we
		 * recorded the creds used when it was originally
		 * locked in the nlm_file_svid structure.
		 */
		mtx_lock(&nlm_svid_lock);
		for (i = 0; i < NLM_SVID_HASH_SIZE; i++) {
			for (ns = LIST_FIRST(&nlm_file_svids[i]); ns;
			     ns = LIST_NEXT(ns, ns_link)) {
				if (ns->ns_svid == fl->l_pid) {
					cred = crhold(ns->ns_ucred);
					break;
				}
			}
		}
		mtx_unlock(&nlm_svid_lock);
	} else {
		/*
		 * This lock is owned by a process. Get a reference to
		 * the process creds.
		 */
		p = pfind(fl->l_pid);
		if (p) {
			cred = crhold(p->p_ucred);
			PROC_UNLOCK(p);
		}
	}

	/*
	 * If we can't find a cred, fall back on the recovery
	 * thread's cred.
	 */
	if (!cred) {
		cred = crhold(td->td_ucred);
	}

	td->td_ucred = cred;
}

static int
nlm_reclaim_free_lock(struct vnode *vp, struct flock *fl, void *arg)
{
	struct flock newfl;
	struct thread *td = curthread;
	struct ucred *oldcred;
	int error;

	newfl = *fl;
	newfl.l_type = F_UNLCK;

	oldcred = td->td_ucred;
	nlm_set_creds_for_lock(td, &newfl);

	error = nlm_advlock_internal(vp, NULL, F_UNLCK, &newfl, F_REMOTE,
	    FALSE, FALSE);

	crfree(td->td_ucred);
	td->td_ucred = oldcred;

	return (error);
}

int
nlm_reclaim(struct vop_reclaim_args *ap)
{

	nlm_cancel_wait(ap->a_vp);
	lf_iteratelocks_vnode(ap->a_vp, nlm_reclaim_free_lock, NULL);
	return (0);
}

struct nlm_recovery_context {
	struct nlm_host	*nr_host;	/* host we are recovering */
	int		nr_state;	/* remote NSM state for recovery */
};

static int
nlm_client_recover_lock(struct vnode *vp, struct flock *fl, void *arg)
{
	struct nlm_recovery_context *nr = (struct nlm_recovery_context *) arg;
	struct thread *td = curthread;
	struct ucred *oldcred;
	int state, error;

	/*
	 * If the remote NSM state changes during recovery, the host
	 * must have rebooted a second time. In that case, we must
	 * restart the recovery.
	 */
	state = nlm_host_get_state(nr->nr_host);
	if (nr->nr_state != state)
		return (ERESTART);

	error = vn_lock(vp, LK_SHARED);
	if (error)
		return (error);

	oldcred = td->td_ucred;
	nlm_set_creds_for_lock(td, fl);

	error = nlm_advlock_internal(vp, NULL, F_SETLK, fl, F_REMOTE,
	    TRUE, TRUE);

	crfree(td->td_ucred);
	td->td_ucred = oldcred;

	return (error);
}

void
nlm_client_recovery(struct nlm_host *host)
{
	struct nlm_recovery_context nr;
	int sysid, error;

	sysid = NLM_SYSID_CLIENT | nlm_host_get_sysid(host);
	do {
		nr.nr_host = host;
		nr.nr_state = nlm_host_get_state(host);
		error = lf_iteratelocks_sysid(sysid,
		    nlm_client_recover_lock, &nr);
	} while (error == ERESTART);
}

static void
nlm_convert_to_nlm_lock(struct nlm_lock *dst, struct nlm4_lock *src)
{

	dst->caller_name = src->caller_name;
	dst->fh = src->fh;
	dst->oh = src->oh;
	dst->svid = src->svid;
	dst->l_offset = src->l_offset;
	dst->l_len = src->l_len;
}

static void
nlm_convert_to_nlm4_holder(struct nlm4_holder *dst, struct nlm_holder *src)
{

	dst->exclusive = src->exclusive;
	dst->svid = src->svid;
	dst->oh = src->oh;
	dst->l_offset = src->l_offset;
	dst->l_len = src->l_len;
}

static void
nlm_convert_to_nlm4_res(struct nlm4_res *dst, struct nlm_res *src)
{
	dst->cookie = src->cookie;
	dst->stat.stat = (enum nlm4_stats) src->stat.stat;
}

static enum clnt_stat
nlm_test_rpc(rpcvers_t vers, nlm4_testargs *args, nlm4_testres *res, CLIENT *client,
    struct rpc_callextra *ext, struct timeval timo)
{
	if (vers == NLM_VERS4) {
		return nlm4_test_4(args, res, client, ext, timo);
	} else {
		nlm_testargs args1;
		nlm_testres res1;
		enum clnt_stat stat;

		args1.cookie = args->cookie;
		args1.exclusive = args->exclusive;
		nlm_convert_to_nlm_lock(&args1.alock, &args->alock);
		memset(&res1, 0, sizeof(res1));

		stat = nlm_test_1(&args1, &res1, client, ext, timo);

		if (stat == RPC_SUCCESS) {
			res->cookie = res1.cookie;
			res->stat.stat = (enum nlm4_stats) res1.stat.stat;
			if (res1.stat.stat == nlm_denied)
				nlm_convert_to_nlm4_holder(
					&res->stat.nlm4_testrply_u.holder,
					&res1.stat.nlm_testrply_u.holder);
		}

		return (stat);
	}
}

static enum clnt_stat
nlm_lock_rpc(rpcvers_t vers, nlm4_lockargs *args, nlm4_res *res, CLIENT *client,
    struct rpc_callextra *ext, struct timeval timo)
{
	if (vers == NLM_VERS4) {
		return nlm4_lock_4(args, res, client, ext, timo);
	} else {
		nlm_lockargs args1;
		nlm_res res1;
		enum clnt_stat stat;

		args1.cookie = args->cookie;
		args1.block = args->block;
		args1.exclusive = args->exclusive;
		nlm_convert_to_nlm_lock(&args1.alock, &args->alock);
		args1.reclaim = args->reclaim;
		args1.state = args->state;
		memset(&res1, 0, sizeof(res1));

		stat = nlm_lock_1(&args1, &res1, client, ext, timo);

		if (stat == RPC_SUCCESS) {
			nlm_convert_to_nlm4_res(res, &res1);
		}

		return (stat);
	}
}

static enum clnt_stat
nlm_cancel_rpc(rpcvers_t vers, nlm4_cancargs *args, nlm4_res *res, CLIENT *client,
    struct rpc_callextra *ext, struct timeval timo)
{
	if (vers == NLM_VERS4) {
		return nlm4_cancel_4(args, res, client, ext, timo);
	} else {
		nlm_cancargs args1;
		nlm_res res1;
		enum clnt_stat stat;

		args1.cookie = args->cookie;
		args1.block = args->block;
		args1.exclusive = args->exclusive;
		nlm_convert_to_nlm_lock(&args1.alock, &args->alock);
		memset(&res1, 0, sizeof(res1));

		stat = nlm_cancel_1(&args1, &res1, client, ext, timo);

		if (stat == RPC_SUCCESS) {
			nlm_convert_to_nlm4_res(res, &res1);
		}

		return (stat);
	}
}

static enum clnt_stat
nlm_unlock_rpc(rpcvers_t vers, nlm4_unlockargs *args, nlm4_res *res, CLIENT *client,
    struct rpc_callextra *ext, struct timeval timo)
{
	if (vers == NLM_VERS4) {
		return nlm4_unlock_4(args, res, client, ext, timo);
	} else {
		nlm_unlockargs args1;
		nlm_res res1;
		enum clnt_stat stat;

		args1.cookie = args->cookie;
		nlm_convert_to_nlm_lock(&args1.alock, &args->alock);
		memset(&res1, 0, sizeof(res1));

		stat = nlm_unlock_1(&args1, &res1, client, ext, timo);

		if (stat == RPC_SUCCESS) {
			nlm_convert_to_nlm4_res(res, &res1);
		}

		return (stat);
	}
}

/*
 * Called after a lock request (set or clear) succeeded. We record the
 * details in the local lock manager. Note that since the remote
 * server has granted the lock, we can be sure that it doesn't
 * conflict with any other locks we have in the local lock manager.
 *
 * Since it is possible that host may also make NLM client requests to
 * our NLM server, we use a different sysid value to record our own
 * client locks.
 *
 * Note that since it is possible for us to receive replies from the
 * server in a different order than the locks were granted (e.g. if
 * many local threads are contending for the same lock), we must use a
 * blocking operation when registering with the local lock manager.
 * We expect that any actual wait will be rare and short hence we
 * ignore signals for this.
 */
static void
nlm_record_lock(struct vnode *vp, int op, struct flock *fl,
    int svid, int sysid, off_t size)
{
	struct vop_advlockasync_args a;
	struct flock newfl;
	int error;

	a.a_vp = vp;
	a.a_id = NULL;
	a.a_op = op;
	a.a_fl = &newfl;
	a.a_flags = F_REMOTE|F_WAIT|F_NOINTR;
	a.a_task = NULL;
	a.a_cookiep = NULL;
	newfl.l_start = fl->l_start;
	newfl.l_len = fl->l_len;
	newfl.l_type = fl->l_type;
	newfl.l_whence = fl->l_whence;
	newfl.l_pid = svid;
	newfl.l_sysid = NLM_SYSID_CLIENT | sysid;

	error = lf_advlockasync(&a, &vp->v_lockf, size);
	KASSERT(error == 0, ("Failed to register NFS lock locally - error=%d",
		error));
}

static int
nlm_setlock(struct nlm_host *host, struct rpc_callextra *ext,
    rpcvers_t vers, struct timeval *timo, int retries,
    struct vnode *vp, int op, struct flock *fl, int flags,
    int svid, size_t fhlen, void *fh, off_t size, bool_t reclaim)
{
	struct nlm4_lockargs args;
	char oh_space[32];
	struct nlm4_res res;
	u_int xid;
	CLIENT *client;
	enum clnt_stat stat;
	int retry, block, exclusive;
	void *wait_handle = NULL;
	int error;

	memset(&args, 0, sizeof(args));
	memset(&res, 0, sizeof(res));

	block = (flags & F_WAIT) ? TRUE : FALSE;
	exclusive = (fl->l_type == F_WRLCK);

	error = nlm_init_lock(fl, flags, svid, vers, fhlen, fh, size,
	    &args.alock, oh_space);
	if (error)
		return (error);
	args.block = block;
	args.exclusive = exclusive;
	args.reclaim = reclaim;
	args.state = nlm_nsm_state;

	retry = 5*hz;
	for (;;) {
		client = nlm_host_get_rpc(host, FALSE);
		if (!client)
			return (ENOLCK); /* XXX retry? */

		if (block)
			wait_handle = nlm_register_wait_lock(&args.alock, vp);

		xid = atomic_fetchadd_int(&nlm_xid, 1);
		args.cookie.n_len = sizeof(xid);
		args.cookie.n_bytes = (char*) &xid;

		stat = nlm_lock_rpc(vers, &args, &res, client, ext, *timo);

		CLNT_RELEASE(client);

		if (stat != RPC_SUCCESS) {
			if (block)
				nlm_deregister_wait_lock(wait_handle);
			if (retries) {
				retries--;
				continue;
			}
			return (EINVAL);
		}

		/*
		 * Free res.cookie.
		 */
		xdr_free((xdrproc_t) xdr_nlm4_res, &res);

		if (block && res.stat.stat != nlm4_blocked)
			nlm_deregister_wait_lock(wait_handle);

		if (res.stat.stat == nlm4_denied_grace_period) {
			/*
			 * The server has recently rebooted and is
			 * giving old clients a change to reclaim
			 * their locks. Wait for a few seconds and try
			 * again.
			 */
			error = tsleep(&args, PCATCH, "nlmgrace", retry);
			if (error && error != EWOULDBLOCK)
				return (error);
			retry = 2*retry;
			if (retry > 30*hz)
				retry = 30*hz;
			continue;
		}

		if (block && res.stat.stat == nlm4_blocked) {
			/*
			 * The server should call us back with a
			 * granted message when the lock succeeds. In
			 * order to deal with broken servers, lost
			 * granted messages and server reboots, we
			 * will also re-try every few seconds.
			 */
			error = nlm_wait_lock(wait_handle, retry);
			if (error == EWOULDBLOCK) {
				retry = 2*retry;
				if (retry > 30*hz)
					retry = 30*hz;
				continue;
			}
			if (error) {
				/*
				 * We need to call the server to
				 * cancel our lock request.
				 */
				nlm4_cancargs cancel;

				memset(&cancel, 0, sizeof(cancel));

				xid = atomic_fetchadd_int(&nlm_xid, 1);
				cancel.cookie.n_len = sizeof(xid);
				cancel.cookie.n_bytes = (char*) &xid;
				cancel.block = block;
				cancel.exclusive = exclusive;
				cancel.alock = args.alock;

				do {
					client = nlm_host_get_rpc(host, FALSE);
					if (!client)
						/* XXX retry? */
						return (ENOLCK);

					stat = nlm_cancel_rpc(vers, &cancel,
					    &res, client, ext, *timo);

					CLNT_RELEASE(client);

					if (stat != RPC_SUCCESS) {
						/*
						 * We need to cope
						 * with temporary
						 * network partitions
						 * as well as server
						 * reboots. This means
						 * we have to keep
						 * trying to cancel
						 * until the server
						 * wakes up again.
						 */
						pause("nlmcancel", 10*hz);
					}
				} while (stat != RPC_SUCCESS);

				/*
				 * Free res.cookie.
				 */
				xdr_free((xdrproc_t) xdr_nlm4_res, &res);

				switch (res.stat.stat) {
				case nlm_denied:
					/*
					 * There was nothing
					 * to cancel. We are
					 * going to go ahead
					 * and assume we got
					 * the lock.
					 */
					error = 0;
					break;

				case nlm4_denied_grace_period:
					/*
					 * The server has
					 * recently rebooted -
					 * treat this as a
					 * successful
					 * cancellation.
					 */
					break;

				case nlm4_granted:
					/*
					 * We managed to
					 * cancel.
					 */
					break;

				default:
					/*
					 * Broken server
					 * implementation -
					 * can't really do
					 * anything here.
					 */
					break;
				}

			}
		} else {
			error = nlm_map_status(res.stat.stat);
		}

		if (!error && !reclaim) {
			nlm_record_lock(vp, op, fl, args.alock.svid,
			    nlm_host_get_sysid(host), size);
			nlm_host_monitor(host, 0);
		}

		return (error);
	}
}

static int
nlm_clearlock(struct nlm_host *host, struct rpc_callextra *ext,
    rpcvers_t vers, struct timeval *timo, int retries,
    struct vnode *vp, int op, struct flock *fl, int flags,
    int svid, size_t fhlen, void *fh, off_t size)
{
	struct nlm4_unlockargs args;
	char oh_space[32];
	struct nlm4_res res;
	u_int xid;
	CLIENT *client;
	enum clnt_stat stat;
	int error;

	memset(&args, 0, sizeof(args));
	memset(&res, 0, sizeof(res));

	error = nlm_init_lock(fl, flags, svid, vers, fhlen, fh, size,
	    &args.alock, oh_space);
	if (error)
		return (error);

	for (;;) {
		client = nlm_host_get_rpc(host, FALSE);
		if (!client)
			return (ENOLCK); /* XXX retry? */

		xid = atomic_fetchadd_int(&nlm_xid, 1);
		args.cookie.n_len = sizeof(xid);
		args.cookie.n_bytes = (char*) &xid;

		stat = nlm_unlock_rpc(vers, &args, &res, client, ext, *timo);

		CLNT_RELEASE(client);

		if (stat != RPC_SUCCESS) {
			if (retries) {
				retries--;
				continue;
			}
			return (EINVAL);
		}

		/*
		 * Free res.cookie.
		 */
		xdr_free((xdrproc_t) xdr_nlm4_res, &res);

		if (res.stat.stat == nlm4_denied_grace_period) {
			/*
			 * The server has recently rebooted and is
			 * giving old clients a change to reclaim
			 * their locks. Wait for a few seconds and try
			 * again.
			 */
			error = tsleep(&args, PCATCH, "nlmgrace", 5*hz);
			if (error && error != EWOULDBLOCK)
				return (error);
			continue;
		}

		/*
		 * If we are being called via nlm_reclaim (which will
		 * use the F_REMOTE flag), don't record the lock
		 * operation in the local lock manager since the vnode
		 * is going away.
		 */
		if (!(flags & F_REMOTE))
			nlm_record_lock(vp, op, fl, args.alock.svid,
			    nlm_host_get_sysid(host), size);

		return (0);
	}
}

static int
nlm_getlock(struct nlm_host *host, struct rpc_callextra *ext,
    rpcvers_t vers, struct timeval *timo, int retries,
    struct vnode *vp, int op, struct flock *fl, int flags,
    int svid, size_t fhlen, void *fh, off_t size)
{
	struct nlm4_testargs args;
	char oh_space[32];
	struct nlm4_testres res;
	u_int xid;
	CLIENT *client;
	enum clnt_stat stat;
	int exclusive;
	int error;

	KASSERT(!(flags & F_FLOCK), ("unexpected F_FLOCK for F_GETLK"));

	memset(&args, 0, sizeof(args));
	memset(&res, 0, sizeof(res));

	exclusive = (fl->l_type == F_WRLCK);

	error = nlm_init_lock(fl, flags, svid, vers, fhlen, fh, size,
	    &args.alock, oh_space);
	if (error)
		return (error);
	args.exclusive = exclusive;

	for (;;) {
		client = nlm_host_get_rpc(host, FALSE);
		if (!client)
			return (ENOLCK); /* XXX retry? */

		xid = atomic_fetchadd_int(&nlm_xid, 1);
		args.cookie.n_len = sizeof(xid);
		args.cookie.n_bytes = (char*) &xid;

		stat = nlm_test_rpc(vers, &args, &res, client, ext, *timo);

		CLNT_RELEASE(client);

		if (stat != RPC_SUCCESS) {
			if (retries) {
				retries--;
				continue;
			}
			return (EINVAL);
		}

		if (res.stat.stat == nlm4_denied_grace_period) {
			/*
			 * The server has recently rebooted and is
			 * giving old clients a change to reclaim
			 * their locks. Wait for a few seconds and try
			 * again.
			 */
			xdr_free((xdrproc_t) xdr_nlm4_testres, &res);
			error = tsleep(&args, PCATCH, "nlmgrace", 5*hz);
			if (error && error != EWOULDBLOCK)
				return (error);
			continue;
		}

		if (res.stat.stat == nlm4_denied) {
			struct nlm4_holder *h =
				&res.stat.nlm4_testrply_u.holder;
			fl->l_start = h->l_offset;
			fl->l_len = h->l_len;
			fl->l_pid = h->svid;
			if (h->exclusive)
				fl->l_type = F_WRLCK;
			else
				fl->l_type = F_RDLCK;
			fl->l_whence = SEEK_SET;
			fl->l_sysid = 0;
		} else {
			fl->l_type = F_UNLCK;
		}

		xdr_free((xdrproc_t) xdr_nlm4_testres, &res);

		return (0);
	}
}

static int
nlm_map_status(nlm4_stats stat)
{
	switch (stat) {
	case nlm4_granted:
		return (0);

	case nlm4_denied:
		return (EAGAIN);

	case nlm4_denied_nolocks:
		return (ENOLCK);

	case nlm4_deadlck:
		return (EDEADLK);

	case nlm4_rofs:
		return (EROFS);

	case nlm4_stale_fh:
		return (ESTALE);

	case nlm4_fbig:
		return (EFBIG);

	case nlm4_failed:
		return (EACCES);

	default:
		return (EINVAL);
	}
}

static struct nlm_file_svid *
nlm_find_svid(void *id)
{
	struct nlm_file_svid *ns, *newns;
	int h;

	h = (((uintptr_t) id) >> 7) % NLM_SVID_HASH_SIZE;

	mtx_lock(&nlm_svid_lock);
	LIST_FOREACH(ns, &nlm_file_svids[h], ns_link) {
		if (ns->ns_id == id) {
			ns->ns_refs++;
			break;
		}
	}
	mtx_unlock(&nlm_svid_lock);
	if (!ns) {
		int svid = alloc_unr(nlm_svid_allocator);
		newns = malloc(sizeof(struct nlm_file_svid), M_NLM,
		    M_WAITOK);
		newns->ns_refs = 1;
		newns->ns_id = id;
		newns->ns_svid = svid;
		newns->ns_ucred = NULL;
		newns->ns_active = FALSE;

		/*
		 * We need to check for a race with some other
		 * thread allocating a svid for this file.
		 */
		mtx_lock(&nlm_svid_lock);
		LIST_FOREACH(ns, &nlm_file_svids[h], ns_link) {
			if (ns->ns_id == id) {
				ns->ns_refs++;
				break;
			}
		}
		if (ns) {
			mtx_unlock(&nlm_svid_lock);
			free_unr(nlm_svid_allocator, newns->ns_svid);
			free(newns, M_NLM);
		} else {
			LIST_INSERT_HEAD(&nlm_file_svids[h], newns,
			    ns_link);
			ns = newns;
			mtx_unlock(&nlm_svid_lock);
		}
	}

	return (ns);
}

static void
nlm_free_svid(struct nlm_file_svid *ns)
{

	mtx_lock(&nlm_svid_lock);
	ns->ns_refs--;
	if (!ns->ns_refs) {
		KASSERT(!ns->ns_active, ("Freeing active SVID"));
		LIST_REMOVE(ns, ns_link);
		mtx_unlock(&nlm_svid_lock);
		free_unr(nlm_svid_allocator, ns->ns_svid);
		if (ns->ns_ucred)
			crfree(ns->ns_ucred);
		free(ns, M_NLM);
	} else {
		mtx_unlock(&nlm_svid_lock);
	}
}

static int
nlm_init_lock(struct flock *fl, int flags, int svid,
    rpcvers_t vers, size_t fhlen, void *fh, off_t size,
    struct nlm4_lock *lock, char oh_space[32])
{
	size_t oh_len;
	off_t start, len;

	if (fl->l_whence == SEEK_END) {
		if (size > OFF_MAX
		    || (fl->l_start > 0 && size > OFF_MAX - fl->l_start))
			return (EOVERFLOW);
		start = size + fl->l_start;
	} else if (fl->l_whence == SEEK_SET || fl->l_whence == SEEK_CUR) {
		start = fl->l_start;
	} else {
		return (EINVAL);
	}
	if (start < 0)
		return (EINVAL);
	if (fl->l_len < 0) {
		len = -fl->l_len;
		start -= len;
		if (start < 0)
			return (EINVAL);
	} else {
		len = fl->l_len;
	}

	if (vers == NLM_VERS) {
		/*
		 * Enforce range limits on V1 locks
		 */
		if (start > 0xffffffffLL || len > 0xffffffffLL)
			return (EOVERFLOW);
	}

	mtx_lock(&hostname_mtx);
	snprintf(oh_space, 32, "%d@%s", svid, G_hostname);
	mtx_unlock(&hostname_mtx);
	oh_len = strlen(oh_space);

	memset(lock, 0, sizeof(*lock));
	lock->caller_name = G_hostname;
	lock->fh.n_len = fhlen;
	lock->fh.n_bytes = fh;
	lock->oh.n_len = oh_len;
	lock->oh.n_bytes = oh_space;
	lock->svid = svid;
	lock->l_offset = start;
	lock->l_len = len;

	return (0);
}
OpenPOWER on IntegriCloud