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
|
/*-
* Copyright (c) 1989, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Rick Macklem at The University of Guelph.
*
* 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.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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("$FreeBSD$");
/*
* Here is the basic algorithm:
* First, some design criteria I used:
* - I think a false hit is more serious than a false miss
* - A false hit for an RPC that has Op(s) that order via seqid# must be
* avoided at all cost
* - A valid hit will probably happen a long time after the original reply
* and the TCP socket that the original request was received on will no
* longer be active
* (The long time delay implies to me that LRU is not appropriate.)
* - The mechanism will satisfy the requirements of ordering Ops with seqid#s
* in them as well as minimizing the risk of redoing retried non-idempotent
* Ops.
* Because it is biased towards avoiding false hits, multiple entries with
* the same xid are to be expected, especially for the case of the entry
* in the cache being related to a seqid# sequenced Op.
*
* The basic algorithm I'm about to code up:
* - Null RPCs bypass the cache and are just done
* For TCP
* - key on <xid, NFS version> (as noted above, there can be several
* entries with the same key)
* When a request arrives:
* For all that match key
* - if RPC# != OR request_size !=
* - not a match with this one
* - if NFSv4 and received on same TCP socket OR
* received on a TCP connection created before the
* entry was cached
* - not a match with this one
* (V2,3 clients might retry on same TCP socket)
* - calculate checksum on first N bytes of NFS XDR
* - if checksum !=
* - not a match for this one
* If any of the remaining ones that match has a
* seqid_refcnt > 0
* - not a match (go do RPC, using new cache entry)
* If one match left
* - a hit (reply from cache)
* else
* - miss (go do RPC, using new cache entry)
*
* During processing of NFSv4 request:
* - set a flag when a non-idempotent Op is processed
* - when an Op that uses a seqid# (Open,...) is processed
* - if same seqid# as referenced entry in cache
* - free new cache entry
* - reply from referenced cache entry
* else if next seqid# in order
* - free referenced cache entry
* - increment seqid_refcnt on new cache entry
* - set pointer from Openowner/Lockowner to
* new cache entry (aka reference it)
* else if first seqid# in sequence
* - increment seqid_refcnt on new cache entry
* - set pointer from Openowner/Lockowner to
* new cache entry (aka reference it)
*
* At end of RPC processing:
* - if seqid_refcnt > 0 OR flagged non-idempotent on new
* cache entry
* - save reply in cache entry
* - calculate checksum on first N bytes of NFS XDR
* request
* - note op and length of XDR request (in bytes)
* - timestamp it
* else
* - free new cache entry
* - Send reply (noting info for socket activity check, below)
*
* For cache entries saved above:
* - if saved since seqid_refcnt was > 0
* - free when seqid_refcnt decrements to 0
* (when next one in sequence is processed above, or
* when Openowner/Lockowner is discarded)
* else { non-idempotent Op(s) }
* - free when
* - some further activity observed on same
* socket
* (I'm not yet sure how I'm going to do
* this. Maybe look at the TCP connection
* to see if the send_tcp_sequence# is well
* past sent reply OR K additional RPCs
* replied on same socket OR?)
* OR
* - when very old (hours, days, weeks?)
*
* For UDP (v2, 3 only), pretty much the old way:
* - key on <xid, NFS version, RPC#, Client host ip#>
* (at most one entry for each key)
*
* When a Request arrives:
* - if a match with entry via key
* - if RPC marked In_progress
* - discard request (don't send reply)
* else
* - reply from cache
* - timestamp cache entry
* else
* - add entry to cache, marked In_progress
* - do RPC
* - when RPC done
* - if RPC# non-idempotent
* - mark entry Done (not In_progress)
* - save reply
* - timestamp cache entry
* else
* - free cache entry
* - send reply
*
* Later, entries with saved replies are free'd a short time (few minutes)
* after reply sent (timestamp).
* Reference: Chet Juszczak, "Improving the Performance and Correctness
* of an NFS Server", in Proc. Winter 1989 USENIX Conference,
* pages 53-63. San Diego, February 1989.
* for the UDP case.
* nfsrc_floodlevel is set to the allowable upper limit for saved replies
* for TCP. For V3, a reply won't be saved when the flood level is
* hit. For V4, the non-idempotent Op will return NFSERR_RESOURCE in
* that case. This level should be set high enough that this almost
* never happens.
*/
#ifndef APPLEKEXT
#include <fs/nfs/nfsport.h>
extern struct nfsstats newnfsstats;
NFSCACHEMUTEX;
int nfsrc_floodlevel = NFSRVCACHE_FLOODLEVEL, nfsrc_tcpsavedreplies = 0;
#endif /* !APPLEKEXT */
static int nfsrc_tcpnonidempotent = 1;
static int nfsrc_udphighwater = NFSRVCACHE_UDPHIGHWATER, nfsrc_udpcachesize = 0;
static TAILQ_HEAD(, nfsrvcache) nfsrvudplru;
static struct nfsrvhashhead nfsrvhashtbl[NFSRVCACHE_HASHSIZE],
nfsrvudphashtbl[NFSRVCACHE_HASHSIZE];
/*
* and the reverse mapping from generic to Version 2 procedure numbers
*/
static int newnfsv2_procid[NFS_V3NPROCS] = {
NFSV2PROC_NULL,
NFSV2PROC_GETATTR,
NFSV2PROC_SETATTR,
NFSV2PROC_LOOKUP,
NFSV2PROC_NOOP,
NFSV2PROC_READLINK,
NFSV2PROC_READ,
NFSV2PROC_WRITE,
NFSV2PROC_CREATE,
NFSV2PROC_MKDIR,
NFSV2PROC_SYMLINK,
NFSV2PROC_CREATE,
NFSV2PROC_REMOVE,
NFSV2PROC_RMDIR,
NFSV2PROC_RENAME,
NFSV2PROC_LINK,
NFSV2PROC_READDIR,
NFSV2PROC_NOOP,
NFSV2PROC_STATFS,
NFSV2PROC_NOOP,
NFSV2PROC_NOOP,
NFSV2PROC_NOOP,
};
#define NFSRCUDPHASH(xid) \
(&nfsrvudphashtbl[((xid) + ((xid) >> 24)) % NFSRVCACHE_HASHSIZE])
#define NFSRCHASH(xid) \
(&nfsrvhashtbl[((xid) + ((xid) >> 24)) % NFSRVCACHE_HASHSIZE])
#define TRUE 1
#define FALSE 0
#define NFSRVCACHE_CHECKLEN 100
/* True iff the rpc reply is an nfs status ONLY! */
static int nfsv2_repstat[NFS_V3NPROCS] = {
FALSE,
FALSE,
FALSE,
FALSE,
FALSE,
FALSE,
FALSE,
FALSE,
FALSE,
FALSE,
TRUE,
TRUE,
TRUE,
TRUE,
FALSE,
TRUE,
FALSE,
FALSE,
FALSE,
FALSE,
FALSE,
FALSE,
};
/*
* Will NFS want to work over IPv6 someday?
*/
#define NETFAMILY(rp) \
(((rp)->rc_flag & RC_INETIPV6) ? AF_INET6 : AF_INET)
/* local functions */
static int nfsrc_getudp(struct nfsrv_descript *nd, struct nfsrvcache *newrp);
static int nfsrc_gettcp(struct nfsrv_descript *nd, struct nfsrvcache *newrp);
static void nfsrc_lock(struct nfsrvcache *rp);
static void nfsrc_unlock(struct nfsrvcache *rp);
static void nfsrc_wanted(struct nfsrvcache *rp);
static void nfsrc_freecache(struct nfsrvcache *rp);
static void nfsrc_trimcache(u_int64_t, struct socket *);
static int nfsrc_activesocket(struct nfsrvcache *rp, u_int64_t,
struct socket *);
static int nfsrc_getlenandcksum(mbuf_t m1, u_int16_t *cksum);
static void nfsrc_marksametcpconn(u_int64_t);
/*
* Initialize the server request cache list
*/
APPLESTATIC void
nfsrvd_initcache(void)
{
int i;
static int inited = 0;
if (inited)
return;
inited = 1;
for (i = 0; i < NFSRVCACHE_HASHSIZE; i++) {
LIST_INIT(&nfsrvudphashtbl[i]);
LIST_INIT(&nfsrvhashtbl[i]);
}
TAILQ_INIT(&nfsrvudplru);
nfsrc_tcpsavedreplies = 0;
nfsrc_udpcachesize = 0;
newnfsstats.srvcache_tcppeak = 0;
newnfsstats.srvcache_size = 0;
}
/*
* Get a cache entry for this request. Basically just malloc a new one
* and then call nfsrc_getudp() or nfsrc_gettcp() to do the rest.
* Call nfsrc_trimcache() to clean up the cache before returning.
*/
APPLESTATIC int
nfsrvd_getcache(struct nfsrv_descript *nd, struct socket *so)
{
struct nfsrvcache *newrp;
int ret;
if (nd->nd_procnum == NFSPROC_NULL)
panic("nfsd cache null");
MALLOC(newrp, struct nfsrvcache *, sizeof (struct nfsrvcache),
M_NFSRVCACHE, M_WAITOK);
NFSBZERO((caddr_t)newrp, sizeof (struct nfsrvcache));
if (nd->nd_flag & ND_NFSV4)
newrp->rc_flag = RC_NFSV4;
else if (nd->nd_flag & ND_NFSV3)
newrp->rc_flag = RC_NFSV3;
else
newrp->rc_flag = RC_NFSV2;
newrp->rc_xid = nd->nd_retxid;
newrp->rc_proc = nd->nd_procnum;
newrp->rc_sockref = nd->nd_sockref;
newrp->rc_cachetime = nd->nd_tcpconntime;
if (nd->nd_flag & ND_SAMETCPCONN)
newrp->rc_flag |= RC_SAMETCPCONN;
if (nd->nd_nam2 != NULL) {
newrp->rc_flag |= RC_UDP;
ret = nfsrc_getudp(nd, newrp);
} else {
ret = nfsrc_gettcp(nd, newrp);
}
nfsrc_trimcache(nd->nd_sockref, so);
return (ret);
}
/*
* For UDP (v2, v3):
* - key on <xid, NFS version, RPC#, Client host ip#>
* (at most one entry for each key)
*/
static int
nfsrc_getudp(struct nfsrv_descript *nd, struct nfsrvcache *newrp)
{
struct nfsrvcache *rp;
struct sockaddr_in *saddr;
struct sockaddr_in6 *saddr6;
struct nfsrvhashhead *hp;
int ret = 0;
hp = NFSRCUDPHASH(newrp->rc_xid);
loop:
NFSLOCKCACHE();
LIST_FOREACH(rp, hp, rc_hash) {
if (newrp->rc_xid == rp->rc_xid &&
newrp->rc_proc == rp->rc_proc &&
(newrp->rc_flag & rp->rc_flag & RC_NFSVERS) &&
nfsaddr_match(NETFAMILY(rp), &rp->rc_haddr, nd->nd_nam)) {
if ((rp->rc_flag & RC_LOCKED) != 0) {
rp->rc_flag |= RC_WANTED;
NFSUNLOCKCACHE();
(void) tsleep((caddr_t)rp, PZERO - 1,
"nfsrc", 10 * hz);
goto loop;
}
if (rp->rc_flag == 0)
panic("nfs udp cache0");
rp->rc_flag |= RC_LOCKED;
TAILQ_REMOVE(&nfsrvudplru, rp, rc_lru);
TAILQ_INSERT_TAIL(&nfsrvudplru, rp, rc_lru);
if (rp->rc_flag & RC_INPROG) {
newnfsstats.srvcache_inproghits++;
NFSUNLOCKCACHE();
ret = RC_DROPIT;
} else if (rp->rc_flag & RC_REPSTATUS) {
/*
* V2 only.
*/
newnfsstats.srvcache_nonidemdonehits++;
NFSUNLOCKCACHE();
nfsrvd_rephead(nd);
*(nd->nd_errp) = rp->rc_status;
ret = RC_REPLY;
rp->rc_timestamp = NFSD_MONOSEC +
NFSRVCACHE_UDPTIMEOUT;
} else if (rp->rc_flag & RC_REPMBUF) {
newnfsstats.srvcache_nonidemdonehits++;
NFSUNLOCKCACHE();
nd->nd_mreq = m_copym(rp->rc_reply, 0,
M_COPYALL, M_WAIT);
ret = RC_REPLY;
rp->rc_timestamp = NFSD_MONOSEC +
NFSRVCACHE_UDPTIMEOUT;
} else {
panic("nfs udp cache1");
}
nfsrc_unlock(rp);
free((caddr_t)newrp, M_NFSRVCACHE);
return (ret);
}
}
newnfsstats.srvcache_misses++;
newnfsstats.srvcache_size++;
nfsrc_udpcachesize++;
newrp->rc_flag |= RC_INPROG;
saddr = NFSSOCKADDR(nd->nd_nam, struct sockaddr_in *);
if (saddr->sin_family == AF_INET)
newrp->rc_inet = saddr->sin_addr.s_addr;
else if (saddr->sin_family == AF_INET6) {
saddr6 = (struct sockaddr_in6 *)saddr;
NFSBCOPY((caddr_t)&saddr6->sin6_addr, (caddr_t)&newrp->rc_inet6,
sizeof (struct in6_addr));
newrp->rc_flag |= RC_INETIPV6;
}
LIST_INSERT_HEAD(hp, newrp, rc_hash);
TAILQ_INSERT_TAIL(&nfsrvudplru, newrp, rc_lru);
NFSUNLOCKCACHE();
nd->nd_rp = newrp;
return (RC_DOIT);
}
/*
* Update a request cache entry after the rpc has been done
*/
APPLESTATIC struct nfsrvcache *
nfsrvd_updatecache(struct nfsrv_descript *nd, struct socket *so)
{
struct nfsrvcache *rp;
struct nfsrvcache *retrp = NULL;
rp = nd->nd_rp;
if (!rp)
panic("nfsrvd_updatecache null rp");
nd->nd_rp = NULL;
NFSLOCKCACHE();
nfsrc_lock(rp);
if (!(rp->rc_flag & RC_INPROG))
panic("nfsrvd_updatecache not inprog");
rp->rc_flag &= ~RC_INPROG;
if (rp->rc_flag & RC_UDP) {
TAILQ_REMOVE(&nfsrvudplru, rp, rc_lru);
TAILQ_INSERT_TAIL(&nfsrvudplru, rp, rc_lru);
}
/*
* Reply from cache is a special case returned by nfsrv_checkseqid().
*/
if (nd->nd_repstat == NFSERR_REPLYFROMCACHE) {
newnfsstats.srvcache_nonidemdonehits++;
NFSUNLOCKCACHE();
nd->nd_repstat = 0;
if (nd->nd_mreq)
mbuf_freem(nd->nd_mreq);
if (!(rp->rc_flag & RC_REPMBUF))
panic("reply from cache");
nd->nd_mreq = m_copym(rp->rc_reply, 0,
M_COPYALL, M_WAIT);
rp->rc_timestamp = NFSD_MONOSEC + NFSRVCACHE_TCPTIMEOUT;
nfsrc_unlock(rp);
nfsrc_trimcache(nd->nd_sockref, so);
return (retrp);
}
/*
* If rc_refcnt > 0, save it
* For UDP, save it if ND_SAVEREPLY is set
* For TCP, save it if ND_SAVEREPLY and nfsrc_tcpnonidempotent is set
*/
if (nd->nd_repstat != NFSERR_DONTREPLY &&
(rp->rc_refcnt > 0 ||
((nd->nd_flag & ND_SAVEREPLY) && (rp->rc_flag & RC_UDP)) ||
((nd->nd_flag & ND_SAVEREPLY) && !(rp->rc_flag & RC_UDP) &&
nfsrc_tcpsavedreplies <= nfsrc_floodlevel &&
nfsrc_tcpnonidempotent))) {
if (rp->rc_refcnt > 0) {
if (!(rp->rc_flag & RC_NFSV4))
panic("update_cache refcnt");
rp->rc_flag |= RC_REFCNT;
}
if ((nd->nd_flag & ND_NFSV2) &&
nfsv2_repstat[newnfsv2_procid[nd->nd_procnum]]) {
NFSUNLOCKCACHE();
rp->rc_status = nd->nd_repstat;
rp->rc_flag |= RC_REPSTATUS;
} else {
if (!(rp->rc_flag & RC_UDP)) {
nfsrc_tcpsavedreplies++;
if (nfsrc_tcpsavedreplies >
newnfsstats.srvcache_tcppeak)
newnfsstats.srvcache_tcppeak =
nfsrc_tcpsavedreplies;
}
NFSUNLOCKCACHE();
rp->rc_reply = m_copym(nd->nd_mreq, 0, M_COPYALL,
M_WAIT);
rp->rc_flag |= RC_REPMBUF;
}
if (rp->rc_flag & RC_UDP) {
rp->rc_timestamp = NFSD_MONOSEC +
NFSRVCACHE_UDPTIMEOUT;
nfsrc_unlock(rp);
} else {
rp->rc_timestamp = NFSD_MONOSEC +
NFSRVCACHE_TCPTIMEOUT;
if (rp->rc_refcnt > 0)
nfsrc_unlock(rp);
else
retrp = rp;
}
} else {
nfsrc_freecache(rp);
NFSUNLOCKCACHE();
}
nfsrc_trimcache(nd->nd_sockref, so);
return (retrp);
}
/*
* Invalidate and, if possible, free an in prog cache entry.
* Must not sleep.
*/
APPLESTATIC void
nfsrvd_delcache(struct nfsrvcache *rp)
{
if (!(rp->rc_flag & RC_INPROG))
panic("nfsrvd_delcache not in prog");
NFSLOCKCACHE();
rp->rc_flag &= ~RC_INPROG;
if (rp->rc_refcnt == 0 && !(rp->rc_flag & RC_LOCKED))
nfsrc_freecache(rp);
NFSUNLOCKCACHE();
}
/*
* Called after nfsrvd_updatecache() once the reply is sent, to update
* the entry for nfsrc_activesocket() and unlock it. The argument is
* the pointer returned by nfsrvd_updatecache().
*/
APPLESTATIC void
nfsrvd_sentcache(struct nfsrvcache *rp, struct socket *so, int err)
{
if (!(rp->rc_flag & RC_LOCKED))
panic("nfsrvd_sentcache not locked");
if (!err) {
if ((so->so_proto->pr_domain->dom_family != AF_INET &&
so->so_proto->pr_domain->dom_family != AF_INET6) ||
so->so_proto->pr_protocol != IPPROTO_TCP)
panic("nfs sent cache");
if (nfsrv_getsockseqnum(so, &rp->rc_tcpseq))
rp->rc_flag |= RC_TCPSEQ;
}
nfsrc_unlock(rp);
}
/*
* Get a cache entry for TCP
* - key on <xid, nfs version>
* (allow multiple entries for a given key)
*/
static int
nfsrc_gettcp(struct nfsrv_descript *nd, struct nfsrvcache *newrp)
{
struct nfsrvcache *rp, *nextrp;
int i;
struct nfsrvcache *hitrp;
struct nfsrvhashhead *hp, nfsrc_templist;
int hit, ret = 0;
hp = NFSRCHASH(newrp->rc_xid);
newrp->rc_reqlen = nfsrc_getlenandcksum(nd->nd_mrep, &newrp->rc_cksum);
tryagain:
NFSLOCKCACHE();
hit = 1;
LIST_INIT(&nfsrc_templist);
/*
* Get all the matches and put them on the temp list.
*/
rp = LIST_FIRST(hp);
while (rp != LIST_END(hp)) {
nextrp = LIST_NEXT(rp, rc_hash);
if (newrp->rc_xid == rp->rc_xid &&
(!(rp->rc_flag & RC_INPROG) ||
((newrp->rc_flag & RC_SAMETCPCONN) &&
newrp->rc_sockref == rp->rc_sockref)) &&
(newrp->rc_flag & rp->rc_flag & RC_NFSVERS) &&
newrp->rc_proc == rp->rc_proc &&
((newrp->rc_flag & RC_NFSV4) &&
newrp->rc_sockref != rp->rc_sockref &&
newrp->rc_cachetime >= rp->rc_cachetime)
&& newrp->rc_reqlen == rp->rc_reqlen &&
newrp->rc_cksum == rp->rc_cksum) {
LIST_REMOVE(rp, rc_hash);
LIST_INSERT_HEAD(&nfsrc_templist, rp, rc_hash);
}
rp = nextrp;
}
/*
* Now, use nfsrc_templist to decide if there is a match.
*/
i = 0;
LIST_FOREACH(rp, &nfsrc_templist, rc_hash) {
i++;
if (rp->rc_refcnt > 0) {
hit = 0;
break;
}
}
/*
* Can be a hit only if one entry left.
* Note possible hit entry and put nfsrc_templist back on hash
* list.
*/
if (i != 1)
hit = 0;
hitrp = rp = LIST_FIRST(&nfsrc_templist);
while (rp != LIST_END(&nfsrc_templist)) {
nextrp = LIST_NEXT(rp, rc_hash);
LIST_REMOVE(rp, rc_hash);
LIST_INSERT_HEAD(hp, rp, rc_hash);
rp = nextrp;
}
if (LIST_FIRST(&nfsrc_templist) != LIST_END(&nfsrc_templist))
panic("nfs gettcp cache templist");
if (hit) {
rp = hitrp;
if ((rp->rc_flag & RC_LOCKED) != 0) {
rp->rc_flag |= RC_WANTED;
NFSUNLOCKCACHE();
(void) tsleep((caddr_t)rp, PZERO-1, "nfsrc", 10 * hz);
goto tryagain;
}
if (rp->rc_flag == 0)
panic("nfs tcp cache0");
rp->rc_flag |= RC_LOCKED;
if (rp->rc_flag & RC_INPROG) {
newnfsstats.srvcache_inproghits++;
NFSUNLOCKCACHE();
if (newrp->rc_sockref == rp->rc_sockref)
nfsrc_marksametcpconn(rp->rc_sockref);
ret = RC_DROPIT;
} else if (rp->rc_flag & RC_REPSTATUS) {
/*
* V2 only.
*/
newnfsstats.srvcache_nonidemdonehits++;
NFSUNLOCKCACHE();
if (newrp->rc_sockref == rp->rc_sockref)
nfsrc_marksametcpconn(rp->rc_sockref);
ret = RC_REPLY;
nfsrvd_rephead(nd);
*(nd->nd_errp) = rp->rc_status;
rp->rc_timestamp = NFSD_MONOSEC +
NFSRVCACHE_TCPTIMEOUT;
} else if (rp->rc_flag & RC_REPMBUF) {
newnfsstats.srvcache_nonidemdonehits++;
NFSUNLOCKCACHE();
if (newrp->rc_sockref == rp->rc_sockref)
nfsrc_marksametcpconn(rp->rc_sockref);
ret = RC_REPLY;
nd->nd_mreq = m_copym(rp->rc_reply, 0,
M_COPYALL, M_WAIT);
rp->rc_timestamp = NFSD_MONOSEC +
NFSRVCACHE_TCPTIMEOUT;
} else {
panic("nfs tcp cache1");
}
nfsrc_unlock(rp);
free((caddr_t)newrp, M_NFSRVCACHE);
return (ret);
}
newnfsstats.srvcache_misses++;
newnfsstats.srvcache_size++;
/*
* For TCP, multiple entries for a key are allowed, so don't
* chain it into the hash table until done.
*/
newrp->rc_cachetime = NFSD_MONOSEC;
newrp->rc_flag |= RC_INPROG;
LIST_INSERT_HEAD(hp, newrp, rc_hash);
NFSUNLOCKCACHE();
nd->nd_rp = newrp;
return (RC_DOIT);
}
/*
* Lock a cache entry.
* Also puts a mutex lock on the cache list.
*/
static void
nfsrc_lock(struct nfsrvcache *rp)
{
NFSCACHELOCKREQUIRED();
while ((rp->rc_flag & RC_LOCKED) != 0) {
rp->rc_flag |= RC_WANTED;
(void) nfsmsleep((caddr_t)rp, NFSCACHEMUTEXPTR, PZERO - 1,
"nfsrc", 0);
}
rp->rc_flag |= RC_LOCKED;
}
/*
* Unlock a cache entry.
*/
static void
nfsrc_unlock(struct nfsrvcache *rp)
{
rp->rc_flag &= ~RC_LOCKED;
nfsrc_wanted(rp);
}
/*
* Wakeup anyone wanting entry.
*/
static void
nfsrc_wanted(struct nfsrvcache *rp)
{
if (rp->rc_flag & RC_WANTED) {
rp->rc_flag &= ~RC_WANTED;
wakeup((caddr_t)rp);
}
}
/*
* Free up the entry.
* Must not sleep.
*/
static void
nfsrc_freecache(struct nfsrvcache *rp)
{
NFSCACHELOCKREQUIRED();
LIST_REMOVE(rp, rc_hash);
if (rp->rc_flag & RC_UDP) {
TAILQ_REMOVE(&nfsrvudplru, rp, rc_lru);
nfsrc_udpcachesize--;
}
nfsrc_wanted(rp);
if (rp->rc_flag & RC_REPMBUF) {
mbuf_freem(rp->rc_reply);
if (!(rp->rc_flag & RC_UDP))
nfsrc_tcpsavedreplies--;
}
FREE((caddr_t)rp, M_NFSRVCACHE);
newnfsstats.srvcache_size--;
}
#ifdef notdef
/*
* Clean out the cache. Called when the last nfsd terminates.
*/
APPLESTATIC void
nfsrvd_cleancache(void)
{
struct nfsrvcache *rp, *nextrp;
int i;
NFSLOCKCACHE();
for (i = 0; i < NFSRVCACHE_HASHSIZE; i++) {
LIST_FOREACH_SAFE(rp, &nfsrvhashtbl[i], rc_hash, nextrp) {
nfsrc_freecache(rp);
}
}
for (i = 0; i < NFSRVCACHE_HASHSIZE; i++) {
LIST_FOREACH_SAFE(rp, &nfsrvudphashtbl[i], rc_hash, nextrp) {
nfsrc_freecache(rp);
}
}
newnfsstats.srvcache_size = 0;
nfsrc_tcpsavedreplies = 0;
NFSUNLOCKCACHE();
}
#endif /* notdef */
/*
* The basic rule is to get rid of entries that are expired.
*/
static void
nfsrc_trimcache(u_int64_t sockref, struct socket *so)
{
struct nfsrvcache *rp, *nextrp;
int i;
NFSLOCKCACHE();
TAILQ_FOREACH_SAFE(rp, &nfsrvudplru, rc_lru, nextrp) {
if (!(rp->rc_flag & (RC_INPROG|RC_LOCKED|RC_WANTED))
&& rp->rc_refcnt == 0
&& ((rp->rc_flag & RC_REFCNT) ||
NFSD_MONOSEC > rp->rc_timestamp ||
nfsrc_udpcachesize > nfsrc_udphighwater))
nfsrc_freecache(rp);
}
for (i = 0; i < NFSRVCACHE_HASHSIZE; i++) {
LIST_FOREACH_SAFE(rp, &nfsrvhashtbl[i], rc_hash, nextrp) {
if (!(rp->rc_flag & (RC_INPROG|RC_LOCKED|RC_WANTED))
&& rp->rc_refcnt == 0
&& ((rp->rc_flag & RC_REFCNT) ||
NFSD_MONOSEC > rp->rc_timestamp ||
nfsrc_activesocket(rp, sockref, so)))
nfsrc_freecache(rp);
}
}
NFSUNLOCKCACHE();
}
/*
* Add a seqid# reference to the cache entry.
*/
APPLESTATIC void
nfsrvd_refcache(struct nfsrvcache *rp)
{
NFSLOCKCACHE();
if (rp->rc_refcnt < 0)
panic("nfs cache refcnt");
rp->rc_refcnt++;
NFSUNLOCKCACHE();
}
/*
* Dereference a seqid# cache entry.
*/
APPLESTATIC void
nfsrvd_derefcache(struct nfsrvcache *rp)
{
NFSLOCKCACHE();
if (rp->rc_refcnt <= 0)
panic("nfs cache derefcnt");
rp->rc_refcnt--;
if (rp->rc_refcnt == 0 && !(rp->rc_flag & (RC_LOCKED | RC_INPROG)))
nfsrc_freecache(rp);
NFSUNLOCKCACHE();
}
/*
* Check to see if the socket is active.
* Return 1 if the reply has been received/acknowledged by the client,
* 0 otherwise.
* XXX - Uses tcp internals.
*/
static int
nfsrc_activesocket(struct nfsrvcache *rp, u_int64_t cur_sockref,
struct socket *cur_so)
{
int ret = 0;
if (!(rp->rc_flag & RC_TCPSEQ))
return (ret);
/*
* If the sockref is the same, it is the same TCP connection.
*/
if (cur_sockref == rp->rc_sockref)
ret = nfsrv_checksockseqnum(cur_so, rp->rc_tcpseq);
return (ret);
}
/*
* Calculate the length of the mbuf list and a checksum on the first up to
* NFSRVCACHE_CHECKLEN bytes.
*/
static int
nfsrc_getlenandcksum(mbuf_t m1, u_int16_t *cksum)
{
int len = 0, cklen;
mbuf_t m;
m = m1;
while (m) {
len += mbuf_len(m);
m = mbuf_next(m);
}
cklen = (len > NFSRVCACHE_CHECKLEN) ? NFSRVCACHE_CHECKLEN : len;
*cksum = in_cksum(m1, cklen);
return (len);
}
/*
* Mark a TCP connection that is seeing retries. Should never happen for
* NFSv4.
*/
static void
nfsrc_marksametcpconn(u_int64_t sockref)
{
}
|