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1/*
2 * Copyright (c) 2001 The Regents of the University of Michigan.
3 * All rights reserved.
4 *
5 * Kendrick Smith <kmsmith@umich.edu>
6 * Andy Adamson <andros@umich.edu>
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 *
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 * 3. Neither the name of the University nor the names of its
18 * contributors may be used to endorse or promote products derived
19 * from this software without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
22 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
23 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
24 * DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
26 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
27 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
28 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
29 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
30 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
31 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32 */
33
34#include <linux/sunrpc/clnt.h>
35#include <linux/sunrpc/svc_xprt.h>
36#include <linux/slab.h>
37#include "nfsd.h"
38#include "state.h"
39
40#define NFSDDBG_FACILITY NFSDDBG_PROC
41
42static void nfsd4_mark_cb_fault(struct nfs4_client *, int reason);
43
44#define NFSPROC4_CB_NULL 0
45#define NFSPROC4_CB_COMPOUND 1
46
47/* Index of predefined Linux callback client operations */
48
49enum {
50 NFSPROC4_CLNT_CB_NULL = 0,
51 NFSPROC4_CLNT_CB_RECALL,
52 NFSPROC4_CLNT_CB_SEQUENCE,
53};
54
55#define NFS4_MAXTAGLEN 20
56
57#define NFS4_enc_cb_null_sz 0
58#define NFS4_dec_cb_null_sz 0
59#define cb_compound_enc_hdr_sz 4
60#define cb_compound_dec_hdr_sz (3 + (NFS4_MAXTAGLEN >> 2))
61#define sessionid_sz (NFS4_MAX_SESSIONID_LEN >> 2)
62#define cb_sequence_enc_sz (sessionid_sz + 4 + \
63 1 /* no referring calls list yet */)
64#define cb_sequence_dec_sz (op_dec_sz + sessionid_sz + 4)
65
66#define op_enc_sz 1
67#define op_dec_sz 2
68#define enc_nfs4_fh_sz (1 + (NFS4_FHSIZE >> 2))
69#define enc_stateid_sz (NFS4_STATEID_SIZE >> 2)
70#define NFS4_enc_cb_recall_sz (cb_compound_enc_hdr_sz + \
71 cb_sequence_enc_sz + \
72 1 + enc_stateid_sz + \
73 enc_nfs4_fh_sz)
74
75#define NFS4_dec_cb_recall_sz (cb_compound_dec_hdr_sz + \
76 cb_sequence_dec_sz + \
77 op_dec_sz)
78
79struct nfs4_cb_compound_hdr {
80 /* args */
81 u32 ident; /* minorversion 0 only */
82 u32 nops;
83 __be32 *nops_p;
84 u32 minorversion;
85 /* res */
86 int status;
87};
88
89/*
90 * Handle decode buffer overflows out-of-line.
91 */
92static void print_overflow_msg(const char *func, const struct xdr_stream *xdr)
93{
94 dprintk("NFS: %s prematurely hit the end of our receive buffer. "
95 "Remaining buffer length is %tu words.\n",
96 func, xdr->end - xdr->p);
97}
98
99static __be32 *xdr_encode_empty_array(__be32 *p)
100{
101 *p++ = xdr_zero;
102 return p;
103}
104
105/*
106 * Encode/decode NFSv4 CB basic data types
107 *
108 * Basic NFSv4 callback data types are defined in section 15 of RFC
109 * 3530: "Network File System (NFS) version 4 Protocol" and section
110 * 20 of RFC 5661: "Network File System (NFS) Version 4 Minor Version
111 * 1 Protocol"
112 */
113
114/*
115 * nfs_cb_opnum4
116 *
117 * enum nfs_cb_opnum4 {
118 * OP_CB_GETATTR = 3,
119 * ...
120 * };
121 */
122enum nfs_cb_opnum4 {
123 OP_CB_GETATTR = 3,
124 OP_CB_RECALL = 4,
125 OP_CB_LAYOUTRECALL = 5,
126 OP_CB_NOTIFY = 6,
127 OP_CB_PUSH_DELEG = 7,
128 OP_CB_RECALL_ANY = 8,
129 OP_CB_RECALLABLE_OBJ_AVAIL = 9,
130 OP_CB_RECALL_SLOT = 10,
131 OP_CB_SEQUENCE = 11,
132 OP_CB_WANTS_CANCELLED = 12,
133 OP_CB_NOTIFY_LOCK = 13,
134 OP_CB_NOTIFY_DEVICEID = 14,
135 OP_CB_ILLEGAL = 10044
136};
137
138static void encode_nfs_cb_opnum4(struct xdr_stream *xdr, enum nfs_cb_opnum4 op)
139{
140 __be32 *p;
141
142 p = xdr_reserve_space(xdr, 4);
143 *p = cpu_to_be32(op);
144}
145
146/*
147 * nfs_fh4
148 *
149 * typedef opaque nfs_fh4<NFS4_FHSIZE>;
150 */
151static void encode_nfs_fh4(struct xdr_stream *xdr, const struct knfsd_fh *fh)
152{
153 u32 length = fh->fh_size;
154 __be32 *p;
155
156 BUG_ON(length > NFS4_FHSIZE);
157 p = xdr_reserve_space(xdr, 4 + length);
158 xdr_encode_opaque(p, &fh->fh_base, length);
159}
160
161/*
162 * stateid4
163 *
164 * struct stateid4 {
165 * uint32_t seqid;
166 * opaque other[12];
167 * };
168 */
169static void encode_stateid4(struct xdr_stream *xdr, const stateid_t *sid)
170{
171 __be32 *p;
172
173 p = xdr_reserve_space(xdr, NFS4_STATEID_SIZE);
174 *p++ = cpu_to_be32(sid->si_generation);
175 xdr_encode_opaque_fixed(p, &sid->si_opaque, NFS4_STATEID_OTHER_SIZE);
176}
177
178/*
179 * sessionid4
180 *
181 * typedef opaque sessionid4[NFS4_SESSIONID_SIZE];
182 */
183static void encode_sessionid4(struct xdr_stream *xdr,
184 const struct nfsd4_session *session)
185{
186 __be32 *p;
187
188 p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN);
189 xdr_encode_opaque_fixed(p, session->se_sessionid.data,
190 NFS4_MAX_SESSIONID_LEN);
191}
192
193/*
194 * nfsstat4
195 */
196static const struct {
197 int stat;
198 int errno;
199} nfs_cb_errtbl[] = {
200 { NFS4_OK, 0 },
201 { NFS4ERR_PERM, -EPERM },
202 { NFS4ERR_NOENT, -ENOENT },
203 { NFS4ERR_IO, -EIO },
204 { NFS4ERR_NXIO, -ENXIO },
205 { NFS4ERR_ACCESS, -EACCES },
206 { NFS4ERR_EXIST, -EEXIST },
207 { NFS4ERR_XDEV, -EXDEV },
208 { NFS4ERR_NOTDIR, -ENOTDIR },
209 { NFS4ERR_ISDIR, -EISDIR },
210 { NFS4ERR_INVAL, -EINVAL },
211 { NFS4ERR_FBIG, -EFBIG },
212 { NFS4ERR_NOSPC, -ENOSPC },
213 { NFS4ERR_ROFS, -EROFS },
214 { NFS4ERR_MLINK, -EMLINK },
215 { NFS4ERR_NAMETOOLONG, -ENAMETOOLONG },
216 { NFS4ERR_NOTEMPTY, -ENOTEMPTY },
217 { NFS4ERR_DQUOT, -EDQUOT },
218 { NFS4ERR_STALE, -ESTALE },
219 { NFS4ERR_BADHANDLE, -EBADHANDLE },
220 { NFS4ERR_BAD_COOKIE, -EBADCOOKIE },
221 { NFS4ERR_NOTSUPP, -ENOTSUPP },
222 { NFS4ERR_TOOSMALL, -ETOOSMALL },
223 { NFS4ERR_SERVERFAULT, -ESERVERFAULT },
224 { NFS4ERR_BADTYPE, -EBADTYPE },
225 { NFS4ERR_LOCKED, -EAGAIN },
226 { NFS4ERR_RESOURCE, -EREMOTEIO },
227 { NFS4ERR_SYMLINK, -ELOOP },
228 { NFS4ERR_OP_ILLEGAL, -EOPNOTSUPP },
229 { NFS4ERR_DEADLOCK, -EDEADLK },
230 { -1, -EIO }
231};
232
233/*
234 * If we cannot translate the error, the recovery routines should
235 * handle it.
236 *
237 * Note: remaining NFSv4 error codes have values > 10000, so should
238 * not conflict with native Linux error codes.
239 */
240static int nfs_cb_stat_to_errno(int status)
241{
242 int i;
243
244 for (i = 0; nfs_cb_errtbl[i].stat != -1; i++) {
245 if (nfs_cb_errtbl[i].stat == status)
246 return nfs_cb_errtbl[i].errno;
247 }
248
249 dprintk("NFSD: Unrecognized NFS CB status value: %u\n", status);
250 return -status;
251}
252
253static int decode_cb_op_status(struct xdr_stream *xdr, enum nfs_opnum4 expected,
254 enum nfsstat4 *status)
255{
256 __be32 *p;
257 u32 op;
258
259 p = xdr_inline_decode(xdr, 4 + 4);
260 if (unlikely(p == NULL))
261 goto out_overflow;
262 op = be32_to_cpup(p++);
263 if (unlikely(op != expected))
264 goto out_unexpected;
265 *status = be32_to_cpup(p);
266 return 0;
267out_overflow:
268 print_overflow_msg(__func__, xdr);
269 return -EIO;
270out_unexpected:
271 dprintk("NFSD: Callback server returned operation %d but "
272 "we issued a request for %d\n", op, expected);
273 return -EIO;
274}
275
276/*
277 * CB_COMPOUND4args
278 *
279 * struct CB_COMPOUND4args {
280 * utf8str_cs tag;
281 * uint32_t minorversion;
282 * uint32_t callback_ident;
283 * nfs_cb_argop4 argarray<>;
284 * };
285*/
286static void encode_cb_compound4args(struct xdr_stream *xdr,
287 struct nfs4_cb_compound_hdr *hdr)
288{
289 __be32 * p;
290
291 p = xdr_reserve_space(xdr, 4 + 4 + 4 + 4);
292 p = xdr_encode_empty_array(p); /* empty tag */
293 *p++ = cpu_to_be32(hdr->minorversion);
294 *p++ = cpu_to_be32(hdr->ident);
295
296 hdr->nops_p = p;
297 *p = cpu_to_be32(hdr->nops); /* argarray element count */
298}
299
300/*
301 * Update argarray element count
302 */
303static void encode_cb_nops(struct nfs4_cb_compound_hdr *hdr)
304{
305 BUG_ON(hdr->nops > NFS4_MAX_BACK_CHANNEL_OPS);
306 *hdr->nops_p = cpu_to_be32(hdr->nops);
307}
308
309/*
310 * CB_COMPOUND4res
311 *
312 * struct CB_COMPOUND4res {
313 * nfsstat4 status;
314 * utf8str_cs tag;
315 * nfs_cb_resop4 resarray<>;
316 * };
317 */
318static int decode_cb_compound4res(struct xdr_stream *xdr,
319 struct nfs4_cb_compound_hdr *hdr)
320{
321 u32 length;
322 __be32 *p;
323
324 p = xdr_inline_decode(xdr, 4 + 4);
325 if (unlikely(p == NULL))
326 goto out_overflow;
327 hdr->status = be32_to_cpup(p++);
328 /* Ignore the tag */
329 length = be32_to_cpup(p++);
330 p = xdr_inline_decode(xdr, length + 4);
331 if (unlikely(p == NULL))
332 goto out_overflow;
333 hdr->nops = be32_to_cpup(p);
334 return 0;
335out_overflow:
336 print_overflow_msg(__func__, xdr);
337 return -EIO;
338}
339
340/*
341 * CB_RECALL4args
342 *
343 * struct CB_RECALL4args {
344 * stateid4 stateid;
345 * bool truncate;
346 * nfs_fh4 fh;
347 * };
348 */
349static void encode_cb_recall4args(struct xdr_stream *xdr,
350 const struct nfs4_delegation *dp,
351 struct nfs4_cb_compound_hdr *hdr)
352{
353 __be32 *p;
354
355 encode_nfs_cb_opnum4(xdr, OP_CB_RECALL);
356 encode_stateid4(xdr, &dp->dl_stid.sc_stateid);
357
358 p = xdr_reserve_space(xdr, 4);
359 *p++ = xdr_zero; /* truncate */
360
361 encode_nfs_fh4(xdr, &dp->dl_fh);
362
363 hdr->nops++;
364}
365
366/*
367 * CB_SEQUENCE4args
368 *
369 * struct CB_SEQUENCE4args {
370 * sessionid4 csa_sessionid;
371 * sequenceid4 csa_sequenceid;
372 * slotid4 csa_slotid;
373 * slotid4 csa_highest_slotid;
374 * bool csa_cachethis;
375 * referring_call_list4 csa_referring_call_lists<>;
376 * };
377 */
378static void encode_cb_sequence4args(struct xdr_stream *xdr,
379 const struct nfsd4_callback *cb,
380 struct nfs4_cb_compound_hdr *hdr)
381{
382 struct nfsd4_session *session = cb->cb_clp->cl_cb_session;
383 __be32 *p;
384
385 if (hdr->minorversion == 0)
386 return;
387
388 encode_nfs_cb_opnum4(xdr, OP_CB_SEQUENCE);
389 encode_sessionid4(xdr, session);
390
391 p = xdr_reserve_space(xdr, 4 + 4 + 4 + 4 + 4);
392 *p++ = cpu_to_be32(session->se_cb_seq_nr); /* csa_sequenceid */
393 *p++ = xdr_zero; /* csa_slotid */
394 *p++ = xdr_zero; /* csa_highest_slotid */
395 *p++ = xdr_zero; /* csa_cachethis */
396 xdr_encode_empty_array(p); /* csa_referring_call_lists */
397
398 hdr->nops++;
399}
400
401/*
402 * CB_SEQUENCE4resok
403 *
404 * struct CB_SEQUENCE4resok {
405 * sessionid4 csr_sessionid;
406 * sequenceid4 csr_sequenceid;
407 * slotid4 csr_slotid;
408 * slotid4 csr_highest_slotid;
409 * slotid4 csr_target_highest_slotid;
410 * };
411 *
412 * union CB_SEQUENCE4res switch (nfsstat4 csr_status) {
413 * case NFS4_OK:
414 * CB_SEQUENCE4resok csr_resok4;
415 * default:
416 * void;
417 * };
418 *
419 * Our current back channel implmentation supports a single backchannel
420 * with a single slot.
421 */
422static int decode_cb_sequence4resok(struct xdr_stream *xdr,
423 struct nfsd4_callback *cb)
424{
425 struct nfsd4_session *session = cb->cb_clp->cl_cb_session;
426 struct nfs4_sessionid id;
427 int status;
428 __be32 *p;
429 u32 dummy;
430
431 status = -ESERVERFAULT;
432
433 /*
434 * If the server returns different values for sessionID, slotID or
435 * sequence number, the server is looney tunes.
436 */
437 p = xdr_inline_decode(xdr, NFS4_MAX_SESSIONID_LEN + 4 + 4 + 4 + 4);
438 if (unlikely(p == NULL))
439 goto out_overflow;
440 memcpy(id.data, p, NFS4_MAX_SESSIONID_LEN);
441 if (memcmp(id.data, session->se_sessionid.data,
442 NFS4_MAX_SESSIONID_LEN) != 0) {
443 dprintk("NFS: %s Invalid session id\n", __func__);
444 goto out;
445 }
446 p += XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN);
447
448 dummy = be32_to_cpup(p++);
449 if (dummy != session->se_cb_seq_nr) {
450 dprintk("NFS: %s Invalid sequence number\n", __func__);
451 goto out;
452 }
453
454 dummy = be32_to_cpup(p++);
455 if (dummy != 0) {
456 dprintk("NFS: %s Invalid slotid\n", __func__);
457 goto out;
458 }
459
460 /*
461 * FIXME: process highest slotid and target highest slotid
462 */
463 status = 0;
464out:
465 if (status)
466 nfsd4_mark_cb_fault(cb->cb_clp, status);
467 return status;
468out_overflow:
469 print_overflow_msg(__func__, xdr);
470 return -EIO;
471}
472
473static int decode_cb_sequence4res(struct xdr_stream *xdr,
474 struct nfsd4_callback *cb)
475{
476 enum nfsstat4 nfserr;
477 int status;
478
479 if (cb->cb_minorversion == 0)
480 return 0;
481
482 status = decode_cb_op_status(xdr, OP_CB_SEQUENCE, &nfserr);
483 if (unlikely(status))
484 goto out;
485 if (unlikely(nfserr != NFS4_OK))
486 goto out_default;
487 status = decode_cb_sequence4resok(xdr, cb);
488out:
489 return status;
490out_default:
491 return nfs_cb_stat_to_errno(nfserr);
492}
493
494/*
495 * NFSv4.0 and NFSv4.1 XDR encode functions
496 *
497 * NFSv4.0 callback argument types are defined in section 15 of RFC
498 * 3530: "Network File System (NFS) version 4 Protocol" and section 20
499 * of RFC 5661: "Network File System (NFS) Version 4 Minor Version 1
500 * Protocol".
501 */
502
503/*
504 * NB: Without this zero space reservation, callbacks over krb5p fail
505 */
506static void nfs4_xdr_enc_cb_null(struct rpc_rqst *req, struct xdr_stream *xdr,
507 void *__unused)
508{
509 xdr_reserve_space(xdr, 0);
510}
511
512/*
513 * 20.2. Operation 4: CB_RECALL - Recall a Delegation
514 */
515static void nfs4_xdr_enc_cb_recall(struct rpc_rqst *req, struct xdr_stream *xdr,
516 const struct nfsd4_callback *cb)
517{
518 const struct nfs4_delegation *args = cb->cb_op;
519 struct nfs4_cb_compound_hdr hdr = {
520 .ident = cb->cb_clp->cl_cb_ident,
521 .minorversion = cb->cb_minorversion,
522 };
523
524 encode_cb_compound4args(xdr, &hdr);
525 encode_cb_sequence4args(xdr, cb, &hdr);
526 encode_cb_recall4args(xdr, args, &hdr);
527 encode_cb_nops(&hdr);
528}
529
530
531/*
532 * NFSv4.0 and NFSv4.1 XDR decode functions
533 *
534 * NFSv4.0 callback result types are defined in section 15 of RFC
535 * 3530: "Network File System (NFS) version 4 Protocol" and section 20
536 * of RFC 5661: "Network File System (NFS) Version 4 Minor Version 1
537 * Protocol".
538 */
539
540static int nfs4_xdr_dec_cb_null(struct rpc_rqst *req, struct xdr_stream *xdr,
541 void *__unused)
542{
543 return 0;
544}
545
546/*
547 * 20.2. Operation 4: CB_RECALL - Recall a Delegation
548 */
549static int nfs4_xdr_dec_cb_recall(struct rpc_rqst *rqstp,
550 struct xdr_stream *xdr,
551 struct nfsd4_callback *cb)
552{
553 struct nfs4_cb_compound_hdr hdr;
554 enum nfsstat4 nfserr;
555 int status;
556
557 status = decode_cb_compound4res(xdr, &hdr);
558 if (unlikely(status))
559 goto out;
560
561 if (cb != NULL) {
562 status = decode_cb_sequence4res(xdr, cb);
563 if (unlikely(status))
564 goto out;
565 }
566
567 status = decode_cb_op_status(xdr, OP_CB_RECALL, &nfserr);
568 if (unlikely(status))
569 goto out;
570 if (unlikely(nfserr != NFS4_OK))
571 status = nfs_cb_stat_to_errno(nfserr);
572out:
573 return status;
574}
575
576/*
577 * RPC procedure tables
578 */
579#define PROC(proc, call, argtype, restype) \
580[NFSPROC4_CLNT_##proc] = { \
581 .p_proc = NFSPROC4_CB_##call, \
582 .p_encode = (kxdreproc_t)nfs4_xdr_enc_##argtype, \
583 .p_decode = (kxdrdproc_t)nfs4_xdr_dec_##restype, \
584 .p_arglen = NFS4_enc_##argtype##_sz, \
585 .p_replen = NFS4_dec_##restype##_sz, \
586 .p_statidx = NFSPROC4_CB_##call, \
587 .p_name = #proc, \
588}
589
590static struct rpc_procinfo nfs4_cb_procedures[] = {
591 PROC(CB_NULL, NULL, cb_null, cb_null),
592 PROC(CB_RECALL, COMPOUND, cb_recall, cb_recall),
593};
594
595static struct rpc_version nfs_cb_version4 = {
596/*
597 * Note on the callback rpc program version number: despite language in rfc
598 * 5661 section 18.36.3 requiring servers to use 4 in this field, the
599 * official xdr descriptions for both 4.0 and 4.1 specify version 1, and
600 * in practice that appears to be what implementations use. The section
601 * 18.36.3 language is expected to be fixed in an erratum.
602 */
603 .number = 1,
604 .nrprocs = ARRAY_SIZE(nfs4_cb_procedures),
605 .procs = nfs4_cb_procedures
606};
607
608static const struct rpc_version *nfs_cb_version[] = {
609 &nfs_cb_version4,
610};
611
612static const struct rpc_program cb_program;
613
614static struct rpc_stat cb_stats = {
615 .program = &cb_program
616};
617
618#define NFS4_CALLBACK 0x40000000
619static const struct rpc_program cb_program = {
620 .name = "nfs4_cb",
621 .number = NFS4_CALLBACK,
622 .nrvers = ARRAY_SIZE(nfs_cb_version),
623 .version = nfs_cb_version,
624 .stats = &cb_stats,
625 .pipe_dir_name = "nfsd4_cb",
626};
627
628static int max_cb_time(void)
629{
630 return max(nfsd4_lease/10, (time_t)1) * HZ;
631}
632
633
634static int setup_callback_client(struct nfs4_client *clp, struct nfs4_cb_conn *conn, struct nfsd4_session *ses)
635{
636 struct rpc_timeout timeparms = {
637 .to_initval = max_cb_time(),
638 .to_retries = 0,
639 };
640 struct rpc_create_args args = {
641 .net = &init_net,
642 .address = (struct sockaddr *) &conn->cb_addr,
643 .addrsize = conn->cb_addrlen,
644 .saddress = (struct sockaddr *) &conn->cb_saddr,
645 .timeout = &timeparms,
646 .program = &cb_program,
647 .version = 0,
648 .flags = (RPC_CLNT_CREATE_NOPING | RPC_CLNT_CREATE_QUIET),
649 };
650 struct rpc_clnt *client;
651
652 if (clp->cl_minorversion == 0) {
653 if (!clp->cl_cred.cr_principal &&
654 (clp->cl_cred.cr_flavor >= RPC_AUTH_GSS_KRB5))
655 return -EINVAL;
656 args.client_name = clp->cl_cred.cr_principal;
657 args.prognumber = conn->cb_prog,
658 args.protocol = XPRT_TRANSPORT_TCP;
659 args.authflavor = clp->cl_cred.cr_flavor;
660 clp->cl_cb_ident = conn->cb_ident;
661 } else {
662 if (!conn->cb_xprt)
663 return -EINVAL;
664 clp->cl_cb_conn.cb_xprt = conn->cb_xprt;
665 clp->cl_cb_session = ses;
666 args.bc_xprt = conn->cb_xprt;
667 args.prognumber = clp->cl_cb_session->se_cb_prog;
668 args.protocol = XPRT_TRANSPORT_BC_TCP;
669 args.authflavor = RPC_AUTH_UNIX;
670 }
671 /* Create RPC client */
672 client = rpc_create(&args);
673 if (IS_ERR(client)) {
674 dprintk("NFSD: couldn't create callback client: %ld\n",
675 PTR_ERR(client));
676 return PTR_ERR(client);
677 }
678 clp->cl_cb_client = client;
679 return 0;
680
681}
682
683static void warn_no_callback_path(struct nfs4_client *clp, int reason)
684{
685 dprintk("NFSD: warning: no callback path to client %.*s: error %d\n",
686 (int)clp->cl_name.len, clp->cl_name.data, reason);
687}
688
689static void nfsd4_mark_cb_down(struct nfs4_client *clp, int reason)
690{
691 clp->cl_cb_state = NFSD4_CB_DOWN;
692 warn_no_callback_path(clp, reason);
693}
694
695static void nfsd4_mark_cb_fault(struct nfs4_client *clp, int reason)
696{
697 clp->cl_cb_state = NFSD4_CB_FAULT;
698 warn_no_callback_path(clp, reason);
699}
700
701static void nfsd4_cb_probe_done(struct rpc_task *task, void *calldata)
702{
703 struct nfs4_client *clp = container_of(calldata, struct nfs4_client, cl_cb_null);
704
705 if (task->tk_status)
706 nfsd4_mark_cb_down(clp, task->tk_status);
707 else
708 clp->cl_cb_state = NFSD4_CB_UP;
709}
710
711static const struct rpc_call_ops nfsd4_cb_probe_ops = {
712 /* XXX: release method to ensure we set the cb channel down if
713 * necessary on early failure? */
714 .rpc_call_done = nfsd4_cb_probe_done,
715};
716
717static struct rpc_cred *callback_cred;
718
719int set_callback_cred(void)
720{
721 if (callback_cred)
722 return 0;
723 callback_cred = rpc_lookup_machine_cred("nfs");
724 if (!callback_cred)
725 return -ENOMEM;
726 return 0;
727}
728
729static struct workqueue_struct *callback_wq;
730
731static void run_nfsd4_cb(struct nfsd4_callback *cb)
732{
733 queue_work(callback_wq, &cb->cb_work);
734}
735
736static void do_probe_callback(struct nfs4_client *clp)
737{
738 struct nfsd4_callback *cb = &clp->cl_cb_null;
739
740 cb->cb_op = NULL;
741 cb->cb_clp = clp;
742
743 cb->cb_msg.rpc_proc = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_NULL];
744 cb->cb_msg.rpc_argp = NULL;
745 cb->cb_msg.rpc_resp = NULL;
746 cb->cb_msg.rpc_cred = callback_cred;
747
748 cb->cb_ops = &nfsd4_cb_probe_ops;
749
750 run_nfsd4_cb(cb);
751}
752
753/*
754 * Poke the callback thread to process any updates to the callback
755 * parameters, and send a null probe.
756 */
757void nfsd4_probe_callback(struct nfs4_client *clp)
758{
759 /* XXX: atomicity? Also, should we be using cl_flags? */
760 clp->cl_cb_state = NFSD4_CB_UNKNOWN;
761 set_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags);
762 do_probe_callback(clp);
763}
764
765void nfsd4_probe_callback_sync(struct nfs4_client *clp)
766{
767 nfsd4_probe_callback(clp);
768 flush_workqueue(callback_wq);
769}
770
771void nfsd4_change_callback(struct nfs4_client *clp, struct nfs4_cb_conn *conn)
772{
773 clp->cl_cb_state = NFSD4_CB_UNKNOWN;
774 spin_lock(&clp->cl_lock);
775 memcpy(&clp->cl_cb_conn, conn, sizeof(struct nfs4_cb_conn));
776 spin_unlock(&clp->cl_lock);
777}
778
779/*
780 * There's currently a single callback channel slot.
781 * If the slot is available, then mark it busy. Otherwise, set the
782 * thread for sleeping on the callback RPC wait queue.
783 */
784static bool nfsd41_cb_get_slot(struct nfs4_client *clp, struct rpc_task *task)
785{
786 if (test_and_set_bit(0, &clp->cl_cb_slot_busy) != 0) {
787 rpc_sleep_on(&clp->cl_cb_waitq, task, NULL);
788 dprintk("%s slot is busy\n", __func__);
789 return false;
790 }
791 return true;
792}
793
794/*
795 * TODO: cb_sequence should support referring call lists, cachethis, multiple
796 * slots, and mark callback channel down on communication errors.
797 */
798static void nfsd4_cb_prepare(struct rpc_task *task, void *calldata)
799{
800 struct nfsd4_callback *cb = calldata;
801 struct nfs4_delegation *dp = container_of(cb, struct nfs4_delegation, dl_recall);
802 struct nfs4_client *clp = dp->dl_stid.sc_client;
803 u32 minorversion = clp->cl_minorversion;
804
805 cb->cb_minorversion = minorversion;
806 if (minorversion) {
807 if (!nfsd41_cb_get_slot(clp, task))
808 return;
809 }
810 spin_lock(&clp->cl_lock);
811 if (list_empty(&cb->cb_per_client)) {
812 /* This is the first call, not a restart */
813 cb->cb_done = false;
814 list_add(&cb->cb_per_client, &clp->cl_callbacks);
815 }
816 spin_unlock(&clp->cl_lock);
817 rpc_call_start(task);
818}
819
820static void nfsd4_cb_done(struct rpc_task *task, void *calldata)
821{
822 struct nfsd4_callback *cb = calldata;
823 struct nfs4_delegation *dp = container_of(cb, struct nfs4_delegation, dl_recall);
824 struct nfs4_client *clp = dp->dl_stid.sc_client;
825
826 dprintk("%s: minorversion=%d\n", __func__,
827 clp->cl_minorversion);
828
829 if (clp->cl_minorversion) {
830 /* No need for lock, access serialized in nfsd4_cb_prepare */
831 ++clp->cl_cb_session->se_cb_seq_nr;
832 clear_bit(0, &clp->cl_cb_slot_busy);
833 rpc_wake_up_next(&clp->cl_cb_waitq);
834 dprintk("%s: freed slot, new seqid=%d\n", __func__,
835 clp->cl_cb_session->se_cb_seq_nr);
836
837 /* We're done looking into the sequence information */
838 task->tk_msg.rpc_resp = NULL;
839 }
840}
841
842
843static void nfsd4_cb_recall_done(struct rpc_task *task, void *calldata)
844{
845 struct nfsd4_callback *cb = calldata;
846 struct nfs4_delegation *dp = container_of(cb, struct nfs4_delegation, dl_recall);
847 struct nfs4_client *clp = dp->dl_stid.sc_client;
848 struct rpc_clnt *current_rpc_client = clp->cl_cb_client;
849
850 nfsd4_cb_done(task, calldata);
851
852 if (current_rpc_client != task->tk_client) {
853 /* We're shutting down or changing cl_cb_client; leave
854 * it to nfsd4_process_cb_update to restart the call if
855 * necessary. */
856 return;
857 }
858
859 if (cb->cb_done)
860 return;
861 switch (task->tk_status) {
862 case 0:
863 cb->cb_done = true;
864 return;
865 case -EBADHANDLE:
866 case -NFS4ERR_BAD_STATEID:
867 /* Race: client probably got cb_recall
868 * before open reply granting delegation */
869 break;
870 default:
871 /* Network partition? */
872 nfsd4_mark_cb_down(clp, task->tk_status);
873 }
874 if (dp->dl_retries--) {
875 rpc_delay(task, 2*HZ);
876 task->tk_status = 0;
877 rpc_restart_call_prepare(task);
878 return;
879 }
880 nfsd4_mark_cb_down(clp, task->tk_status);
881 cb->cb_done = true;
882}
883
884static void nfsd4_cb_recall_release(void *calldata)
885{
886 struct nfsd4_callback *cb = calldata;
887 struct nfs4_client *clp = cb->cb_clp;
888 struct nfs4_delegation *dp = container_of(cb, struct nfs4_delegation, dl_recall);
889
890 if (cb->cb_done) {
891 spin_lock(&clp->cl_lock);
892 list_del(&cb->cb_per_client);
893 spin_unlock(&clp->cl_lock);
894 nfs4_put_delegation(dp);
895 }
896}
897
898static const struct rpc_call_ops nfsd4_cb_recall_ops = {
899 .rpc_call_prepare = nfsd4_cb_prepare,
900 .rpc_call_done = nfsd4_cb_recall_done,
901 .rpc_release = nfsd4_cb_recall_release,
902};
903
904int nfsd4_create_callback_queue(void)
905{
906 callback_wq = create_singlethread_workqueue("nfsd4_callbacks");
907 if (!callback_wq)
908 return -ENOMEM;
909 return 0;
910}
911
912void nfsd4_destroy_callback_queue(void)
913{
914 destroy_workqueue(callback_wq);
915}
916
917/* must be called under the state lock */
918void nfsd4_shutdown_callback(struct nfs4_client *clp)
919{
920 set_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags);
921 /*
922 * Note this won't actually result in a null callback;
923 * instead, nfsd4_do_callback_rpc() will detect the killed
924 * client, destroy the rpc client, and stop:
925 */
926 do_probe_callback(clp);
927 flush_workqueue(callback_wq);
928}
929
930static void nfsd4_release_cb(struct nfsd4_callback *cb)
931{
932 if (cb->cb_ops->rpc_release)
933 cb->cb_ops->rpc_release(cb);
934}
935
936/* requires cl_lock: */
937static struct nfsd4_conn * __nfsd4_find_backchannel(struct nfs4_client *clp)
938{
939 struct nfsd4_session *s;
940 struct nfsd4_conn *c;
941
942 list_for_each_entry(s, &clp->cl_sessions, se_perclnt) {
943 list_for_each_entry(c, &s->se_conns, cn_persession) {
944 if (c->cn_flags & NFS4_CDFC4_BACK)
945 return c;
946 }
947 }
948 return NULL;
949}
950
951static void nfsd4_process_cb_update(struct nfsd4_callback *cb)
952{
953 struct nfs4_cb_conn conn;
954 struct nfs4_client *clp = cb->cb_clp;
955 struct nfsd4_session *ses = NULL;
956 struct nfsd4_conn *c;
957 int err;
958
959 /*
960 * This is either an update, or the client dying; in either case,
961 * kill the old client:
962 */
963 if (clp->cl_cb_client) {
964 rpc_shutdown_client(clp->cl_cb_client);
965 clp->cl_cb_client = NULL;
966 }
967 if (clp->cl_cb_conn.cb_xprt) {
968 svc_xprt_put(clp->cl_cb_conn.cb_xprt);
969 clp->cl_cb_conn.cb_xprt = NULL;
970 }
971 if (test_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags))
972 return;
973 spin_lock(&clp->cl_lock);
974 /*
975 * Only serialized callback code is allowed to clear these
976 * flags; main nfsd code can only set them:
977 */
978 BUG_ON(!(clp->cl_flags & NFSD4_CLIENT_CB_FLAG_MASK));
979 clear_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags);
980 memcpy(&conn, &cb->cb_clp->cl_cb_conn, sizeof(struct nfs4_cb_conn));
981 c = __nfsd4_find_backchannel(clp);
982 if (c) {
983 svc_xprt_get(c->cn_xprt);
984 conn.cb_xprt = c->cn_xprt;
985 ses = c->cn_session;
986 }
987 spin_unlock(&clp->cl_lock);
988
989 err = setup_callback_client(clp, &conn, ses);
990 if (err) {
991 nfsd4_mark_cb_down(clp, err);
992 return;
993 }
994 /* Yay, the callback channel's back! Restart any callbacks: */
995 list_for_each_entry(cb, &clp->cl_callbacks, cb_per_client)
996 run_nfsd4_cb(cb);
997}
998
999void nfsd4_do_callback_rpc(struct work_struct *w)
1000{
1001 struct nfsd4_callback *cb = container_of(w, struct nfsd4_callback, cb_work);
1002 struct nfs4_client *clp = cb->cb_clp;
1003 struct rpc_clnt *clnt;
1004
1005 if (clp->cl_flags & NFSD4_CLIENT_CB_FLAG_MASK)
1006 nfsd4_process_cb_update(cb);
1007
1008 clnt = clp->cl_cb_client;
1009 if (!clnt) {
1010 /* Callback channel broken, or client killed; give up: */
1011 nfsd4_release_cb(cb);
1012 return;
1013 }
1014 rpc_call_async(clnt, &cb->cb_msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN,
1015 cb->cb_ops, cb);
1016}
1017
1018void nfsd4_cb_recall(struct nfs4_delegation *dp)
1019{
1020 struct nfsd4_callback *cb = &dp->dl_recall;
1021 struct nfs4_client *clp = dp->dl_stid.sc_client;
1022
1023 dp->dl_retries = 1;
1024 cb->cb_op = dp;
1025 cb->cb_clp = clp;
1026 cb->cb_msg.rpc_proc = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_RECALL];
1027 cb->cb_msg.rpc_argp = cb;
1028 cb->cb_msg.rpc_resp = cb;
1029 cb->cb_msg.rpc_cred = callback_cred;
1030
1031 cb->cb_ops = &nfsd4_cb_recall_ops;
1032 dp->dl_retries = 1;
1033
1034 INIT_LIST_HEAD(&cb->cb_per_client);
1035 cb->cb_done = true;
1036
1037 run_nfsd4_cb(&dp->dl_recall);
1038}
1/*
2 * Copyright (c) 2001 The Regents of the University of Michigan.
3 * All rights reserved.
4 *
5 * Kendrick Smith <kmsmith@umich.edu>
6 * Andy Adamson <andros@umich.edu>
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 *
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 * 3. Neither the name of the University nor the names of its
18 * contributors may be used to endorse or promote products derived
19 * from this software without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
22 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
23 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
24 * DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
26 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
27 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
28 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
29 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
30 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
31 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32 */
33
34#include <linux/sunrpc/clnt.h>
35#include <linux/sunrpc/svc_xprt.h>
36#include <linux/slab.h>
37#include "nfsd.h"
38#include "state.h"
39
40#define NFSDDBG_FACILITY NFSDDBG_PROC
41
42#define NFSPROC4_CB_NULL 0
43#define NFSPROC4_CB_COMPOUND 1
44
45/* Index of predefined Linux callback client operations */
46
47enum {
48 NFSPROC4_CLNT_CB_NULL = 0,
49 NFSPROC4_CLNT_CB_RECALL,
50 NFSPROC4_CLNT_CB_SEQUENCE,
51};
52
53#define NFS4_MAXTAGLEN 20
54
55#define NFS4_enc_cb_null_sz 0
56#define NFS4_dec_cb_null_sz 0
57#define cb_compound_enc_hdr_sz 4
58#define cb_compound_dec_hdr_sz (3 + (NFS4_MAXTAGLEN >> 2))
59#define sessionid_sz (NFS4_MAX_SESSIONID_LEN >> 2)
60#define cb_sequence_enc_sz (sessionid_sz + 4 + \
61 1 /* no referring calls list yet */)
62#define cb_sequence_dec_sz (op_dec_sz + sessionid_sz + 4)
63
64#define op_enc_sz 1
65#define op_dec_sz 2
66#define enc_nfs4_fh_sz (1 + (NFS4_FHSIZE >> 2))
67#define enc_stateid_sz (NFS4_STATEID_SIZE >> 2)
68#define NFS4_enc_cb_recall_sz (cb_compound_enc_hdr_sz + \
69 cb_sequence_enc_sz + \
70 1 + enc_stateid_sz + \
71 enc_nfs4_fh_sz)
72
73#define NFS4_dec_cb_recall_sz (cb_compound_dec_hdr_sz + \
74 cb_sequence_dec_sz + \
75 op_dec_sz)
76
77struct nfs4_cb_compound_hdr {
78 /* args */
79 u32 ident; /* minorversion 0 only */
80 u32 nops;
81 __be32 *nops_p;
82 u32 minorversion;
83 /* res */
84 int status;
85};
86
87/*
88 * Handle decode buffer overflows out-of-line.
89 */
90static void print_overflow_msg(const char *func, const struct xdr_stream *xdr)
91{
92 dprintk("NFS: %s prematurely hit the end of our receive buffer. "
93 "Remaining buffer length is %tu words.\n",
94 func, xdr->end - xdr->p);
95}
96
97static __be32 *xdr_encode_empty_array(__be32 *p)
98{
99 *p++ = xdr_zero;
100 return p;
101}
102
103/*
104 * Encode/decode NFSv4 CB basic data types
105 *
106 * Basic NFSv4 callback data types are defined in section 15 of RFC
107 * 3530: "Network File System (NFS) version 4 Protocol" and section
108 * 20 of RFC 5661: "Network File System (NFS) Version 4 Minor Version
109 * 1 Protocol"
110 */
111
112/*
113 * nfs_cb_opnum4
114 *
115 * enum nfs_cb_opnum4 {
116 * OP_CB_GETATTR = 3,
117 * ...
118 * };
119 */
120enum nfs_cb_opnum4 {
121 OP_CB_GETATTR = 3,
122 OP_CB_RECALL = 4,
123 OP_CB_LAYOUTRECALL = 5,
124 OP_CB_NOTIFY = 6,
125 OP_CB_PUSH_DELEG = 7,
126 OP_CB_RECALL_ANY = 8,
127 OP_CB_RECALLABLE_OBJ_AVAIL = 9,
128 OP_CB_RECALL_SLOT = 10,
129 OP_CB_SEQUENCE = 11,
130 OP_CB_WANTS_CANCELLED = 12,
131 OP_CB_NOTIFY_LOCK = 13,
132 OP_CB_NOTIFY_DEVICEID = 14,
133 OP_CB_ILLEGAL = 10044
134};
135
136static void encode_nfs_cb_opnum4(struct xdr_stream *xdr, enum nfs_cb_opnum4 op)
137{
138 __be32 *p;
139
140 p = xdr_reserve_space(xdr, 4);
141 *p = cpu_to_be32(op);
142}
143
144/*
145 * nfs_fh4
146 *
147 * typedef opaque nfs_fh4<NFS4_FHSIZE>;
148 */
149static void encode_nfs_fh4(struct xdr_stream *xdr, const struct knfsd_fh *fh)
150{
151 u32 length = fh->fh_size;
152 __be32 *p;
153
154 BUG_ON(length > NFS4_FHSIZE);
155 p = xdr_reserve_space(xdr, 4 + length);
156 xdr_encode_opaque(p, &fh->fh_base, length);
157}
158
159/*
160 * stateid4
161 *
162 * struct stateid4 {
163 * uint32_t seqid;
164 * opaque other[12];
165 * };
166 */
167static void encode_stateid4(struct xdr_stream *xdr, const stateid_t *sid)
168{
169 __be32 *p;
170
171 p = xdr_reserve_space(xdr, NFS4_STATEID_SIZE);
172 *p++ = cpu_to_be32(sid->si_generation);
173 xdr_encode_opaque_fixed(p, &sid->si_opaque, NFS4_STATEID_OTHER_SIZE);
174}
175
176/*
177 * sessionid4
178 *
179 * typedef opaque sessionid4[NFS4_SESSIONID_SIZE];
180 */
181static void encode_sessionid4(struct xdr_stream *xdr,
182 const struct nfsd4_session *session)
183{
184 __be32 *p;
185
186 p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN);
187 xdr_encode_opaque_fixed(p, session->se_sessionid.data,
188 NFS4_MAX_SESSIONID_LEN);
189}
190
191/*
192 * nfsstat4
193 */
194static const struct {
195 int stat;
196 int errno;
197} nfs_cb_errtbl[] = {
198 { NFS4_OK, 0 },
199 { NFS4ERR_PERM, -EPERM },
200 { NFS4ERR_NOENT, -ENOENT },
201 { NFS4ERR_IO, -EIO },
202 { NFS4ERR_NXIO, -ENXIO },
203 { NFS4ERR_ACCESS, -EACCES },
204 { NFS4ERR_EXIST, -EEXIST },
205 { NFS4ERR_XDEV, -EXDEV },
206 { NFS4ERR_NOTDIR, -ENOTDIR },
207 { NFS4ERR_ISDIR, -EISDIR },
208 { NFS4ERR_INVAL, -EINVAL },
209 { NFS4ERR_FBIG, -EFBIG },
210 { NFS4ERR_NOSPC, -ENOSPC },
211 { NFS4ERR_ROFS, -EROFS },
212 { NFS4ERR_MLINK, -EMLINK },
213 { NFS4ERR_NAMETOOLONG, -ENAMETOOLONG },
214 { NFS4ERR_NOTEMPTY, -ENOTEMPTY },
215 { NFS4ERR_DQUOT, -EDQUOT },
216 { NFS4ERR_STALE, -ESTALE },
217 { NFS4ERR_BADHANDLE, -EBADHANDLE },
218 { NFS4ERR_BAD_COOKIE, -EBADCOOKIE },
219 { NFS4ERR_NOTSUPP, -ENOTSUPP },
220 { NFS4ERR_TOOSMALL, -ETOOSMALL },
221 { NFS4ERR_SERVERFAULT, -ESERVERFAULT },
222 { NFS4ERR_BADTYPE, -EBADTYPE },
223 { NFS4ERR_LOCKED, -EAGAIN },
224 { NFS4ERR_RESOURCE, -EREMOTEIO },
225 { NFS4ERR_SYMLINK, -ELOOP },
226 { NFS4ERR_OP_ILLEGAL, -EOPNOTSUPP },
227 { NFS4ERR_DEADLOCK, -EDEADLK },
228 { -1, -EIO }
229};
230
231/*
232 * If we cannot translate the error, the recovery routines should
233 * handle it.
234 *
235 * Note: remaining NFSv4 error codes have values > 10000, so should
236 * not conflict with native Linux error codes.
237 */
238static int nfs_cb_stat_to_errno(int status)
239{
240 int i;
241
242 for (i = 0; nfs_cb_errtbl[i].stat != -1; i++) {
243 if (nfs_cb_errtbl[i].stat == status)
244 return nfs_cb_errtbl[i].errno;
245 }
246
247 dprintk("NFSD: Unrecognized NFS CB status value: %u\n", status);
248 return -status;
249}
250
251static int decode_cb_op_status(struct xdr_stream *xdr, enum nfs_opnum4 expected,
252 enum nfsstat4 *status)
253{
254 __be32 *p;
255 u32 op;
256
257 p = xdr_inline_decode(xdr, 4 + 4);
258 if (unlikely(p == NULL))
259 goto out_overflow;
260 op = be32_to_cpup(p++);
261 if (unlikely(op != expected))
262 goto out_unexpected;
263 *status = be32_to_cpup(p);
264 return 0;
265out_overflow:
266 print_overflow_msg(__func__, xdr);
267 return -EIO;
268out_unexpected:
269 dprintk("NFSD: Callback server returned operation %d but "
270 "we issued a request for %d\n", op, expected);
271 return -EIO;
272}
273
274/*
275 * CB_COMPOUND4args
276 *
277 * struct CB_COMPOUND4args {
278 * utf8str_cs tag;
279 * uint32_t minorversion;
280 * uint32_t callback_ident;
281 * nfs_cb_argop4 argarray<>;
282 * };
283*/
284static void encode_cb_compound4args(struct xdr_stream *xdr,
285 struct nfs4_cb_compound_hdr *hdr)
286{
287 __be32 * p;
288
289 p = xdr_reserve_space(xdr, 4 + 4 + 4 + 4);
290 p = xdr_encode_empty_array(p); /* empty tag */
291 *p++ = cpu_to_be32(hdr->minorversion);
292 *p++ = cpu_to_be32(hdr->ident);
293
294 hdr->nops_p = p;
295 *p = cpu_to_be32(hdr->nops); /* argarray element count */
296}
297
298/*
299 * Update argarray element count
300 */
301static void encode_cb_nops(struct nfs4_cb_compound_hdr *hdr)
302{
303 BUG_ON(hdr->nops > NFS4_MAX_BACK_CHANNEL_OPS);
304 *hdr->nops_p = cpu_to_be32(hdr->nops);
305}
306
307/*
308 * CB_COMPOUND4res
309 *
310 * struct CB_COMPOUND4res {
311 * nfsstat4 status;
312 * utf8str_cs tag;
313 * nfs_cb_resop4 resarray<>;
314 * };
315 */
316static int decode_cb_compound4res(struct xdr_stream *xdr,
317 struct nfs4_cb_compound_hdr *hdr)
318{
319 u32 length;
320 __be32 *p;
321
322 p = xdr_inline_decode(xdr, 4 + 4);
323 if (unlikely(p == NULL))
324 goto out_overflow;
325 hdr->status = be32_to_cpup(p++);
326 /* Ignore the tag */
327 length = be32_to_cpup(p++);
328 p = xdr_inline_decode(xdr, length + 4);
329 if (unlikely(p == NULL))
330 goto out_overflow;
331 hdr->nops = be32_to_cpup(p);
332 return 0;
333out_overflow:
334 print_overflow_msg(__func__, xdr);
335 return -EIO;
336}
337
338/*
339 * CB_RECALL4args
340 *
341 * struct CB_RECALL4args {
342 * stateid4 stateid;
343 * bool truncate;
344 * nfs_fh4 fh;
345 * };
346 */
347static void encode_cb_recall4args(struct xdr_stream *xdr,
348 const struct nfs4_delegation *dp,
349 struct nfs4_cb_compound_hdr *hdr)
350{
351 __be32 *p;
352
353 encode_nfs_cb_opnum4(xdr, OP_CB_RECALL);
354 encode_stateid4(xdr, &dp->dl_stateid);
355
356 p = xdr_reserve_space(xdr, 4);
357 *p++ = xdr_zero; /* truncate */
358
359 encode_nfs_fh4(xdr, &dp->dl_fh);
360
361 hdr->nops++;
362}
363
364/*
365 * CB_SEQUENCE4args
366 *
367 * struct CB_SEQUENCE4args {
368 * sessionid4 csa_sessionid;
369 * sequenceid4 csa_sequenceid;
370 * slotid4 csa_slotid;
371 * slotid4 csa_highest_slotid;
372 * bool csa_cachethis;
373 * referring_call_list4 csa_referring_call_lists<>;
374 * };
375 */
376static void encode_cb_sequence4args(struct xdr_stream *xdr,
377 const struct nfsd4_callback *cb,
378 struct nfs4_cb_compound_hdr *hdr)
379{
380 struct nfsd4_session *session = cb->cb_clp->cl_cb_session;
381 __be32 *p;
382
383 if (hdr->minorversion == 0)
384 return;
385
386 encode_nfs_cb_opnum4(xdr, OP_CB_SEQUENCE);
387 encode_sessionid4(xdr, session);
388
389 p = xdr_reserve_space(xdr, 4 + 4 + 4 + 4 + 4);
390 *p++ = cpu_to_be32(session->se_cb_seq_nr); /* csa_sequenceid */
391 *p++ = xdr_zero; /* csa_slotid */
392 *p++ = xdr_zero; /* csa_highest_slotid */
393 *p++ = xdr_zero; /* csa_cachethis */
394 xdr_encode_empty_array(p); /* csa_referring_call_lists */
395
396 hdr->nops++;
397}
398
399/*
400 * CB_SEQUENCE4resok
401 *
402 * struct CB_SEQUENCE4resok {
403 * sessionid4 csr_sessionid;
404 * sequenceid4 csr_sequenceid;
405 * slotid4 csr_slotid;
406 * slotid4 csr_highest_slotid;
407 * slotid4 csr_target_highest_slotid;
408 * };
409 *
410 * union CB_SEQUENCE4res switch (nfsstat4 csr_status) {
411 * case NFS4_OK:
412 * CB_SEQUENCE4resok csr_resok4;
413 * default:
414 * void;
415 * };
416 *
417 * Our current back channel implmentation supports a single backchannel
418 * with a single slot.
419 */
420static int decode_cb_sequence4resok(struct xdr_stream *xdr,
421 struct nfsd4_callback *cb)
422{
423 struct nfsd4_session *session = cb->cb_clp->cl_cb_session;
424 struct nfs4_sessionid id;
425 int status;
426 __be32 *p;
427 u32 dummy;
428
429 status = -ESERVERFAULT;
430
431 /*
432 * If the server returns different values for sessionID, slotID or
433 * sequence number, the server is looney tunes.
434 */
435 p = xdr_inline_decode(xdr, NFS4_MAX_SESSIONID_LEN + 4 + 4 + 4 + 4);
436 if (unlikely(p == NULL))
437 goto out_overflow;
438 memcpy(id.data, p, NFS4_MAX_SESSIONID_LEN);
439 if (memcmp(id.data, session->se_sessionid.data,
440 NFS4_MAX_SESSIONID_LEN) != 0) {
441 dprintk("NFS: %s Invalid session id\n", __func__);
442 goto out;
443 }
444 p += XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN);
445
446 dummy = be32_to_cpup(p++);
447 if (dummy != session->se_cb_seq_nr) {
448 dprintk("NFS: %s Invalid sequence number\n", __func__);
449 goto out;
450 }
451
452 dummy = be32_to_cpup(p++);
453 if (dummy != 0) {
454 dprintk("NFS: %s Invalid slotid\n", __func__);
455 goto out;
456 }
457
458 /*
459 * FIXME: process highest slotid and target highest slotid
460 */
461 status = 0;
462out:
463 return status;
464out_overflow:
465 print_overflow_msg(__func__, xdr);
466 return -EIO;
467}
468
469static int decode_cb_sequence4res(struct xdr_stream *xdr,
470 struct nfsd4_callback *cb)
471{
472 enum nfsstat4 nfserr;
473 int status;
474
475 if (cb->cb_minorversion == 0)
476 return 0;
477
478 status = decode_cb_op_status(xdr, OP_CB_SEQUENCE, &nfserr);
479 if (unlikely(status))
480 goto out;
481 if (unlikely(nfserr != NFS4_OK))
482 goto out_default;
483 status = decode_cb_sequence4resok(xdr, cb);
484out:
485 return status;
486out_default:
487 return nfs_cb_stat_to_errno(nfserr);
488}
489
490/*
491 * NFSv4.0 and NFSv4.1 XDR encode functions
492 *
493 * NFSv4.0 callback argument types are defined in section 15 of RFC
494 * 3530: "Network File System (NFS) version 4 Protocol" and section 20
495 * of RFC 5661: "Network File System (NFS) Version 4 Minor Version 1
496 * Protocol".
497 */
498
499/*
500 * NB: Without this zero space reservation, callbacks over krb5p fail
501 */
502static void nfs4_xdr_enc_cb_null(struct rpc_rqst *req, struct xdr_stream *xdr,
503 void *__unused)
504{
505 xdr_reserve_space(xdr, 0);
506}
507
508/*
509 * 20.2. Operation 4: CB_RECALL - Recall a Delegation
510 */
511static void nfs4_xdr_enc_cb_recall(struct rpc_rqst *req, struct xdr_stream *xdr,
512 const struct nfsd4_callback *cb)
513{
514 const struct nfs4_delegation *args = cb->cb_op;
515 struct nfs4_cb_compound_hdr hdr = {
516 .ident = cb->cb_clp->cl_cb_ident,
517 .minorversion = cb->cb_minorversion,
518 };
519
520 encode_cb_compound4args(xdr, &hdr);
521 encode_cb_sequence4args(xdr, cb, &hdr);
522 encode_cb_recall4args(xdr, args, &hdr);
523 encode_cb_nops(&hdr);
524}
525
526
527/*
528 * NFSv4.0 and NFSv4.1 XDR decode functions
529 *
530 * NFSv4.0 callback result types are defined in section 15 of RFC
531 * 3530: "Network File System (NFS) version 4 Protocol" and section 20
532 * of RFC 5661: "Network File System (NFS) Version 4 Minor Version 1
533 * Protocol".
534 */
535
536static int nfs4_xdr_dec_cb_null(struct rpc_rqst *req, struct xdr_stream *xdr,
537 void *__unused)
538{
539 return 0;
540}
541
542/*
543 * 20.2. Operation 4: CB_RECALL - Recall a Delegation
544 */
545static int nfs4_xdr_dec_cb_recall(struct rpc_rqst *rqstp,
546 struct xdr_stream *xdr,
547 struct nfsd4_callback *cb)
548{
549 struct nfs4_cb_compound_hdr hdr;
550 enum nfsstat4 nfserr;
551 int status;
552
553 status = decode_cb_compound4res(xdr, &hdr);
554 if (unlikely(status))
555 goto out;
556
557 if (cb != NULL) {
558 status = decode_cb_sequence4res(xdr, cb);
559 if (unlikely(status))
560 goto out;
561 }
562
563 status = decode_cb_op_status(xdr, OP_CB_RECALL, &nfserr);
564 if (unlikely(status))
565 goto out;
566 if (unlikely(nfserr != NFS4_OK))
567 status = nfs_cb_stat_to_errno(nfserr);
568out:
569 return status;
570}
571
572/*
573 * RPC procedure tables
574 */
575#define PROC(proc, call, argtype, restype) \
576[NFSPROC4_CLNT_##proc] = { \
577 .p_proc = NFSPROC4_CB_##call, \
578 .p_encode = (kxdreproc_t)nfs4_xdr_enc_##argtype, \
579 .p_decode = (kxdrdproc_t)nfs4_xdr_dec_##restype, \
580 .p_arglen = NFS4_enc_##argtype##_sz, \
581 .p_replen = NFS4_dec_##restype##_sz, \
582 .p_statidx = NFSPROC4_CB_##call, \
583 .p_name = #proc, \
584}
585
586static struct rpc_procinfo nfs4_cb_procedures[] = {
587 PROC(CB_NULL, NULL, cb_null, cb_null),
588 PROC(CB_RECALL, COMPOUND, cb_recall, cb_recall),
589};
590
591static struct rpc_version nfs_cb_version4 = {
592/*
593 * Note on the callback rpc program version number: despite language in rfc
594 * 5661 section 18.36.3 requiring servers to use 4 in this field, the
595 * official xdr descriptions for both 4.0 and 4.1 specify version 1, and
596 * in practice that appears to be what implementations use. The section
597 * 18.36.3 language is expected to be fixed in an erratum.
598 */
599 .number = 1,
600 .nrprocs = ARRAY_SIZE(nfs4_cb_procedures),
601 .procs = nfs4_cb_procedures
602};
603
604static struct rpc_version *nfs_cb_version[] = {
605 &nfs_cb_version4,
606};
607
608static struct rpc_program cb_program;
609
610static struct rpc_stat cb_stats = {
611 .program = &cb_program
612};
613
614#define NFS4_CALLBACK 0x40000000
615static struct rpc_program cb_program = {
616 .name = "nfs4_cb",
617 .number = NFS4_CALLBACK,
618 .nrvers = ARRAY_SIZE(nfs_cb_version),
619 .version = nfs_cb_version,
620 .stats = &cb_stats,
621 .pipe_dir_name = "/nfsd4_cb",
622};
623
624static int max_cb_time(void)
625{
626 return max(nfsd4_lease/10, (time_t)1) * HZ;
627}
628
629
630static int setup_callback_client(struct nfs4_client *clp, struct nfs4_cb_conn *conn, struct nfsd4_session *ses)
631{
632 struct rpc_timeout timeparms = {
633 .to_initval = max_cb_time(),
634 .to_retries = 0,
635 };
636 struct rpc_create_args args = {
637 .net = &init_net,
638 .address = (struct sockaddr *) &conn->cb_addr,
639 .addrsize = conn->cb_addrlen,
640 .saddress = (struct sockaddr *) &conn->cb_saddr,
641 .timeout = &timeparms,
642 .program = &cb_program,
643 .version = 0,
644 .authflavor = clp->cl_flavor,
645 .flags = (RPC_CLNT_CREATE_NOPING | RPC_CLNT_CREATE_QUIET),
646 };
647 struct rpc_clnt *client;
648
649 if (clp->cl_minorversion == 0) {
650 if (!clp->cl_principal && (clp->cl_flavor >= RPC_AUTH_GSS_KRB5))
651 return -EINVAL;
652 args.client_name = clp->cl_principal;
653 args.prognumber = conn->cb_prog,
654 args.protocol = XPRT_TRANSPORT_TCP;
655 clp->cl_cb_ident = conn->cb_ident;
656 } else {
657 if (!conn->cb_xprt)
658 return -EINVAL;
659 clp->cl_cb_conn.cb_xprt = conn->cb_xprt;
660 clp->cl_cb_session = ses;
661 args.bc_xprt = conn->cb_xprt;
662 args.prognumber = clp->cl_cb_session->se_cb_prog;
663 args.protocol = XPRT_TRANSPORT_BC_TCP;
664 }
665 /* Create RPC client */
666 client = rpc_create(&args);
667 if (IS_ERR(client)) {
668 dprintk("NFSD: couldn't create callback client: %ld\n",
669 PTR_ERR(client));
670 return PTR_ERR(client);
671 }
672 clp->cl_cb_client = client;
673 return 0;
674
675}
676
677static void warn_no_callback_path(struct nfs4_client *clp, int reason)
678{
679 dprintk("NFSD: warning: no callback path to client %.*s: error %d\n",
680 (int)clp->cl_name.len, clp->cl_name.data, reason);
681}
682
683static void nfsd4_mark_cb_down(struct nfs4_client *clp, int reason)
684{
685 clp->cl_cb_state = NFSD4_CB_DOWN;
686 warn_no_callback_path(clp, reason);
687}
688
689static void nfsd4_cb_probe_done(struct rpc_task *task, void *calldata)
690{
691 struct nfs4_client *clp = container_of(calldata, struct nfs4_client, cl_cb_null);
692
693 if (task->tk_status)
694 nfsd4_mark_cb_down(clp, task->tk_status);
695 else
696 clp->cl_cb_state = NFSD4_CB_UP;
697}
698
699static const struct rpc_call_ops nfsd4_cb_probe_ops = {
700 /* XXX: release method to ensure we set the cb channel down if
701 * necessary on early failure? */
702 .rpc_call_done = nfsd4_cb_probe_done,
703};
704
705static struct rpc_cred *callback_cred;
706
707int set_callback_cred(void)
708{
709 if (callback_cred)
710 return 0;
711 callback_cred = rpc_lookup_machine_cred();
712 if (!callback_cred)
713 return -ENOMEM;
714 return 0;
715}
716
717static struct workqueue_struct *callback_wq;
718
719static void run_nfsd4_cb(struct nfsd4_callback *cb)
720{
721 queue_work(callback_wq, &cb->cb_work);
722}
723
724static void do_probe_callback(struct nfs4_client *clp)
725{
726 struct nfsd4_callback *cb = &clp->cl_cb_null;
727
728 cb->cb_op = NULL;
729 cb->cb_clp = clp;
730
731 cb->cb_msg.rpc_proc = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_NULL];
732 cb->cb_msg.rpc_argp = NULL;
733 cb->cb_msg.rpc_resp = NULL;
734 cb->cb_msg.rpc_cred = callback_cred;
735
736 cb->cb_ops = &nfsd4_cb_probe_ops;
737
738 run_nfsd4_cb(cb);
739}
740
741/*
742 * Poke the callback thread to process any updates to the callback
743 * parameters, and send a null probe.
744 */
745void nfsd4_probe_callback(struct nfs4_client *clp)
746{
747 /* XXX: atomicity? Also, should we be using cl_cb_flags? */
748 clp->cl_cb_state = NFSD4_CB_UNKNOWN;
749 set_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_cb_flags);
750 do_probe_callback(clp);
751}
752
753void nfsd4_probe_callback_sync(struct nfs4_client *clp)
754{
755 nfsd4_probe_callback(clp);
756 flush_workqueue(callback_wq);
757}
758
759void nfsd4_change_callback(struct nfs4_client *clp, struct nfs4_cb_conn *conn)
760{
761 clp->cl_cb_state = NFSD4_CB_UNKNOWN;
762 spin_lock(&clp->cl_lock);
763 memcpy(&clp->cl_cb_conn, conn, sizeof(struct nfs4_cb_conn));
764 spin_unlock(&clp->cl_lock);
765}
766
767/*
768 * There's currently a single callback channel slot.
769 * If the slot is available, then mark it busy. Otherwise, set the
770 * thread for sleeping on the callback RPC wait queue.
771 */
772static bool nfsd41_cb_get_slot(struct nfs4_client *clp, struct rpc_task *task)
773{
774 if (test_and_set_bit(0, &clp->cl_cb_slot_busy) != 0) {
775 rpc_sleep_on(&clp->cl_cb_waitq, task, NULL);
776 dprintk("%s slot is busy\n", __func__);
777 return false;
778 }
779 return true;
780}
781
782/*
783 * TODO: cb_sequence should support referring call lists, cachethis, multiple
784 * slots, and mark callback channel down on communication errors.
785 */
786static void nfsd4_cb_prepare(struct rpc_task *task, void *calldata)
787{
788 struct nfsd4_callback *cb = calldata;
789 struct nfs4_delegation *dp = container_of(cb, struct nfs4_delegation, dl_recall);
790 struct nfs4_client *clp = dp->dl_client;
791 u32 minorversion = clp->cl_minorversion;
792
793 cb->cb_minorversion = minorversion;
794 if (minorversion) {
795 if (!nfsd41_cb_get_slot(clp, task))
796 return;
797 }
798 spin_lock(&clp->cl_lock);
799 if (list_empty(&cb->cb_per_client)) {
800 /* This is the first call, not a restart */
801 cb->cb_done = false;
802 list_add(&cb->cb_per_client, &clp->cl_callbacks);
803 }
804 spin_unlock(&clp->cl_lock);
805 rpc_call_start(task);
806}
807
808static void nfsd4_cb_done(struct rpc_task *task, void *calldata)
809{
810 struct nfsd4_callback *cb = calldata;
811 struct nfs4_delegation *dp = container_of(cb, struct nfs4_delegation, dl_recall);
812 struct nfs4_client *clp = dp->dl_client;
813
814 dprintk("%s: minorversion=%d\n", __func__,
815 clp->cl_minorversion);
816
817 if (clp->cl_minorversion) {
818 /* No need for lock, access serialized in nfsd4_cb_prepare */
819 ++clp->cl_cb_session->se_cb_seq_nr;
820 clear_bit(0, &clp->cl_cb_slot_busy);
821 rpc_wake_up_next(&clp->cl_cb_waitq);
822 dprintk("%s: freed slot, new seqid=%d\n", __func__,
823 clp->cl_cb_session->se_cb_seq_nr);
824
825 /* We're done looking into the sequence information */
826 task->tk_msg.rpc_resp = NULL;
827 }
828}
829
830
831static void nfsd4_cb_recall_done(struct rpc_task *task, void *calldata)
832{
833 struct nfsd4_callback *cb = calldata;
834 struct nfs4_delegation *dp = container_of(cb, struct nfs4_delegation, dl_recall);
835 struct nfs4_client *clp = dp->dl_client;
836 struct rpc_clnt *current_rpc_client = clp->cl_cb_client;
837
838 nfsd4_cb_done(task, calldata);
839
840 if (current_rpc_client != task->tk_client) {
841 /* We're shutting down or changing cl_cb_client; leave
842 * it to nfsd4_process_cb_update to restart the call if
843 * necessary. */
844 return;
845 }
846
847 if (cb->cb_done)
848 return;
849 switch (task->tk_status) {
850 case 0:
851 cb->cb_done = true;
852 return;
853 case -EBADHANDLE:
854 case -NFS4ERR_BAD_STATEID:
855 /* Race: client probably got cb_recall
856 * before open reply granting delegation */
857 break;
858 default:
859 /* Network partition? */
860 nfsd4_mark_cb_down(clp, task->tk_status);
861 }
862 if (dp->dl_retries--) {
863 rpc_delay(task, 2*HZ);
864 task->tk_status = 0;
865 rpc_restart_call_prepare(task);
866 return;
867 }
868 nfsd4_mark_cb_down(clp, task->tk_status);
869 cb->cb_done = true;
870}
871
872static void nfsd4_cb_recall_release(void *calldata)
873{
874 struct nfsd4_callback *cb = calldata;
875 struct nfs4_client *clp = cb->cb_clp;
876 struct nfs4_delegation *dp = container_of(cb, struct nfs4_delegation, dl_recall);
877
878 if (cb->cb_done) {
879 spin_lock(&clp->cl_lock);
880 list_del(&cb->cb_per_client);
881 spin_unlock(&clp->cl_lock);
882 nfs4_put_delegation(dp);
883 }
884}
885
886static const struct rpc_call_ops nfsd4_cb_recall_ops = {
887 .rpc_call_prepare = nfsd4_cb_prepare,
888 .rpc_call_done = nfsd4_cb_recall_done,
889 .rpc_release = nfsd4_cb_recall_release,
890};
891
892int nfsd4_create_callback_queue(void)
893{
894 callback_wq = create_singlethread_workqueue("nfsd4_callbacks");
895 if (!callback_wq)
896 return -ENOMEM;
897 return 0;
898}
899
900void nfsd4_destroy_callback_queue(void)
901{
902 destroy_workqueue(callback_wq);
903}
904
905/* must be called under the state lock */
906void nfsd4_shutdown_callback(struct nfs4_client *clp)
907{
908 set_bit(NFSD4_CLIENT_KILL, &clp->cl_cb_flags);
909 /*
910 * Note this won't actually result in a null callback;
911 * instead, nfsd4_do_callback_rpc() will detect the killed
912 * client, destroy the rpc client, and stop:
913 */
914 do_probe_callback(clp);
915 flush_workqueue(callback_wq);
916}
917
918static void nfsd4_release_cb(struct nfsd4_callback *cb)
919{
920 if (cb->cb_ops->rpc_release)
921 cb->cb_ops->rpc_release(cb);
922}
923
924/* requires cl_lock: */
925static struct nfsd4_conn * __nfsd4_find_backchannel(struct nfs4_client *clp)
926{
927 struct nfsd4_session *s;
928 struct nfsd4_conn *c;
929
930 list_for_each_entry(s, &clp->cl_sessions, se_perclnt) {
931 list_for_each_entry(c, &s->se_conns, cn_persession) {
932 if (c->cn_flags & NFS4_CDFC4_BACK)
933 return c;
934 }
935 }
936 return NULL;
937}
938
939static void nfsd4_process_cb_update(struct nfsd4_callback *cb)
940{
941 struct nfs4_cb_conn conn;
942 struct nfs4_client *clp = cb->cb_clp;
943 struct nfsd4_session *ses = NULL;
944 struct nfsd4_conn *c;
945 int err;
946
947 /*
948 * This is either an update, or the client dying; in either case,
949 * kill the old client:
950 */
951 if (clp->cl_cb_client) {
952 rpc_shutdown_client(clp->cl_cb_client);
953 clp->cl_cb_client = NULL;
954 }
955 if (clp->cl_cb_conn.cb_xprt) {
956 svc_xprt_put(clp->cl_cb_conn.cb_xprt);
957 clp->cl_cb_conn.cb_xprt = NULL;
958 }
959 if (test_bit(NFSD4_CLIENT_KILL, &clp->cl_cb_flags))
960 return;
961 spin_lock(&clp->cl_lock);
962 /*
963 * Only serialized callback code is allowed to clear these
964 * flags; main nfsd code can only set them:
965 */
966 BUG_ON(!clp->cl_cb_flags);
967 clear_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_cb_flags);
968 memcpy(&conn, &cb->cb_clp->cl_cb_conn, sizeof(struct nfs4_cb_conn));
969 c = __nfsd4_find_backchannel(clp);
970 if (c) {
971 svc_xprt_get(c->cn_xprt);
972 conn.cb_xprt = c->cn_xprt;
973 ses = c->cn_session;
974 }
975 spin_unlock(&clp->cl_lock);
976
977 err = setup_callback_client(clp, &conn, ses);
978 if (err) {
979 warn_no_callback_path(clp, err);
980 return;
981 }
982 /* Yay, the callback channel's back! Restart any callbacks: */
983 list_for_each_entry(cb, &clp->cl_callbacks, cb_per_client)
984 run_nfsd4_cb(cb);
985}
986
987void nfsd4_do_callback_rpc(struct work_struct *w)
988{
989 struct nfsd4_callback *cb = container_of(w, struct nfsd4_callback, cb_work);
990 struct nfs4_client *clp = cb->cb_clp;
991 struct rpc_clnt *clnt;
992
993 if (clp->cl_cb_flags)
994 nfsd4_process_cb_update(cb);
995
996 clnt = clp->cl_cb_client;
997 if (!clnt) {
998 /* Callback channel broken, or client killed; give up: */
999 nfsd4_release_cb(cb);
1000 return;
1001 }
1002 rpc_call_async(clnt, &cb->cb_msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN,
1003 cb->cb_ops, cb);
1004}
1005
1006void nfsd4_cb_recall(struct nfs4_delegation *dp)
1007{
1008 struct nfsd4_callback *cb = &dp->dl_recall;
1009 struct nfs4_client *clp = dp->dl_client;
1010
1011 dp->dl_retries = 1;
1012 cb->cb_op = dp;
1013 cb->cb_clp = clp;
1014 cb->cb_msg.rpc_proc = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_RECALL];
1015 cb->cb_msg.rpc_argp = cb;
1016 cb->cb_msg.rpc_resp = cb;
1017 cb->cb_msg.rpc_cred = callback_cred;
1018
1019 cb->cb_ops = &nfsd4_cb_recall_ops;
1020 dp->dl_retries = 1;
1021
1022 INIT_LIST_HEAD(&cb->cb_per_client);
1023 cb->cb_done = true;
1024
1025 run_nfsd4_cb(&dp->dl_recall);
1026}