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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/xprt.h>
36#include <linux/sunrpc/svc_xprt.h>
37#include <linux/slab.h>
38#include "nfsd.h"
39#include "state.h"
40#include "netns.h"
41#include "trace.h"
42#include "xdr4cb.h"
43#include "xdr4.h"
44
45#define NFSDDBG_FACILITY NFSDDBG_PROC
46
47static void nfsd4_mark_cb_fault(struct nfs4_client *, int reason);
48
49#define NFSPROC4_CB_NULL 0
50#define NFSPROC4_CB_COMPOUND 1
51
52/* Index of predefined Linux callback client operations */
53
54struct nfs4_cb_compound_hdr {
55 /* args */
56 u32 ident; /* minorversion 0 only */
57 u32 nops;
58 __be32 *nops_p;
59 u32 minorversion;
60 /* res */
61 int status;
62};
63
64static __be32 *xdr_encode_empty_array(__be32 *p)
65{
66 *p++ = xdr_zero;
67 return p;
68}
69
70/*
71 * Encode/decode NFSv4 CB basic data types
72 *
73 * Basic NFSv4 callback data types are defined in section 15 of RFC
74 * 3530: "Network File System (NFS) version 4 Protocol" and section
75 * 20 of RFC 5661: "Network File System (NFS) Version 4 Minor Version
76 * 1 Protocol"
77 */
78
79static void encode_uint32(struct xdr_stream *xdr, u32 n)
80{
81 WARN_ON_ONCE(xdr_stream_encode_u32(xdr, n) < 0);
82}
83
84static void encode_bitmap4(struct xdr_stream *xdr, const __u32 *bitmap,
85 size_t len)
86{
87 WARN_ON_ONCE(xdr_stream_encode_uint32_array(xdr, bitmap, len) < 0);
88}
89
90/*
91 * nfs_cb_opnum4
92 *
93 * enum nfs_cb_opnum4 {
94 * OP_CB_GETATTR = 3,
95 * ...
96 * };
97 */
98enum nfs_cb_opnum4 {
99 OP_CB_GETATTR = 3,
100 OP_CB_RECALL = 4,
101 OP_CB_LAYOUTRECALL = 5,
102 OP_CB_NOTIFY = 6,
103 OP_CB_PUSH_DELEG = 7,
104 OP_CB_RECALL_ANY = 8,
105 OP_CB_RECALLABLE_OBJ_AVAIL = 9,
106 OP_CB_RECALL_SLOT = 10,
107 OP_CB_SEQUENCE = 11,
108 OP_CB_WANTS_CANCELLED = 12,
109 OP_CB_NOTIFY_LOCK = 13,
110 OP_CB_NOTIFY_DEVICEID = 14,
111 OP_CB_OFFLOAD = 15,
112 OP_CB_ILLEGAL = 10044
113};
114
115static void encode_nfs_cb_opnum4(struct xdr_stream *xdr, enum nfs_cb_opnum4 op)
116{
117 __be32 *p;
118
119 p = xdr_reserve_space(xdr, 4);
120 *p = cpu_to_be32(op);
121}
122
123/*
124 * nfs_fh4
125 *
126 * typedef opaque nfs_fh4<NFS4_FHSIZE>;
127 */
128static void encode_nfs_fh4(struct xdr_stream *xdr, const struct knfsd_fh *fh)
129{
130 u32 length = fh->fh_size;
131 __be32 *p;
132
133 BUG_ON(length > NFS4_FHSIZE);
134 p = xdr_reserve_space(xdr, 4 + length);
135 xdr_encode_opaque(p, &fh->fh_raw, length);
136}
137
138/*
139 * stateid4
140 *
141 * struct stateid4 {
142 * uint32_t seqid;
143 * opaque other[12];
144 * };
145 */
146static void encode_stateid4(struct xdr_stream *xdr, const stateid_t *sid)
147{
148 __be32 *p;
149
150 p = xdr_reserve_space(xdr, NFS4_STATEID_SIZE);
151 *p++ = cpu_to_be32(sid->si_generation);
152 xdr_encode_opaque_fixed(p, &sid->si_opaque, NFS4_STATEID_OTHER_SIZE);
153}
154
155/*
156 * sessionid4
157 *
158 * typedef opaque sessionid4[NFS4_SESSIONID_SIZE];
159 */
160static void encode_sessionid4(struct xdr_stream *xdr,
161 const struct nfsd4_session *session)
162{
163 __be32 *p;
164
165 p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN);
166 xdr_encode_opaque_fixed(p, session->se_sessionid.data,
167 NFS4_MAX_SESSIONID_LEN);
168}
169
170/*
171 * nfsstat4
172 */
173static const struct {
174 int stat;
175 int errno;
176} nfs_cb_errtbl[] = {
177 { NFS4_OK, 0 },
178 { NFS4ERR_PERM, -EPERM },
179 { NFS4ERR_NOENT, -ENOENT },
180 { NFS4ERR_IO, -EIO },
181 { NFS4ERR_NXIO, -ENXIO },
182 { NFS4ERR_ACCESS, -EACCES },
183 { NFS4ERR_EXIST, -EEXIST },
184 { NFS4ERR_XDEV, -EXDEV },
185 { NFS4ERR_NOTDIR, -ENOTDIR },
186 { NFS4ERR_ISDIR, -EISDIR },
187 { NFS4ERR_INVAL, -EINVAL },
188 { NFS4ERR_FBIG, -EFBIG },
189 { NFS4ERR_NOSPC, -ENOSPC },
190 { NFS4ERR_ROFS, -EROFS },
191 { NFS4ERR_MLINK, -EMLINK },
192 { NFS4ERR_NAMETOOLONG, -ENAMETOOLONG },
193 { NFS4ERR_NOTEMPTY, -ENOTEMPTY },
194 { NFS4ERR_DQUOT, -EDQUOT },
195 { NFS4ERR_STALE, -ESTALE },
196 { NFS4ERR_BADHANDLE, -EBADHANDLE },
197 { NFS4ERR_BAD_COOKIE, -EBADCOOKIE },
198 { NFS4ERR_NOTSUPP, -ENOTSUPP },
199 { NFS4ERR_TOOSMALL, -ETOOSMALL },
200 { NFS4ERR_SERVERFAULT, -ESERVERFAULT },
201 { NFS4ERR_BADTYPE, -EBADTYPE },
202 { NFS4ERR_LOCKED, -EAGAIN },
203 { NFS4ERR_RESOURCE, -EREMOTEIO },
204 { NFS4ERR_SYMLINK, -ELOOP },
205 { NFS4ERR_OP_ILLEGAL, -EOPNOTSUPP },
206 { NFS4ERR_DEADLOCK, -EDEADLK },
207 { -1, -EIO }
208};
209
210/*
211 * If we cannot translate the error, the recovery routines should
212 * handle it.
213 *
214 * Note: remaining NFSv4 error codes have values > 10000, so should
215 * not conflict with native Linux error codes.
216 */
217static int nfs_cb_stat_to_errno(int status)
218{
219 int i;
220
221 for (i = 0; nfs_cb_errtbl[i].stat != -1; i++) {
222 if (nfs_cb_errtbl[i].stat == status)
223 return nfs_cb_errtbl[i].errno;
224 }
225
226 dprintk("NFSD: Unrecognized NFS CB status value: %u\n", status);
227 return -status;
228}
229
230static int decode_cb_op_status(struct xdr_stream *xdr,
231 enum nfs_cb_opnum4 expected, int *status)
232{
233 __be32 *p;
234 u32 op;
235
236 p = xdr_inline_decode(xdr, 4 + 4);
237 if (unlikely(p == NULL))
238 goto out_overflow;
239 op = be32_to_cpup(p++);
240 if (unlikely(op != expected))
241 goto out_unexpected;
242 *status = nfs_cb_stat_to_errno(be32_to_cpup(p));
243 return 0;
244out_overflow:
245 return -EIO;
246out_unexpected:
247 dprintk("NFSD: Callback server returned operation %d but "
248 "we issued a request for %d\n", op, expected);
249 return -EIO;
250}
251
252/*
253 * CB_COMPOUND4args
254 *
255 * struct CB_COMPOUND4args {
256 * utf8str_cs tag;
257 * uint32_t minorversion;
258 * uint32_t callback_ident;
259 * nfs_cb_argop4 argarray<>;
260 * };
261*/
262static void encode_cb_compound4args(struct xdr_stream *xdr,
263 struct nfs4_cb_compound_hdr *hdr)
264{
265 __be32 * p;
266
267 p = xdr_reserve_space(xdr, 4 + 4 + 4 + 4);
268 p = xdr_encode_empty_array(p); /* empty tag */
269 *p++ = cpu_to_be32(hdr->minorversion);
270 *p++ = cpu_to_be32(hdr->ident);
271
272 hdr->nops_p = p;
273 *p = cpu_to_be32(hdr->nops); /* argarray element count */
274}
275
276/*
277 * Update argarray element count
278 */
279static void encode_cb_nops(struct nfs4_cb_compound_hdr *hdr)
280{
281 BUG_ON(hdr->nops > NFS4_MAX_BACK_CHANNEL_OPS);
282 *hdr->nops_p = cpu_to_be32(hdr->nops);
283}
284
285/*
286 * CB_COMPOUND4res
287 *
288 * struct CB_COMPOUND4res {
289 * nfsstat4 status;
290 * utf8str_cs tag;
291 * nfs_cb_resop4 resarray<>;
292 * };
293 */
294static int decode_cb_compound4res(struct xdr_stream *xdr,
295 struct nfs4_cb_compound_hdr *hdr)
296{
297 u32 length;
298 __be32 *p;
299
300 p = xdr_inline_decode(xdr, 4 + 4);
301 if (unlikely(p == NULL))
302 goto out_overflow;
303 hdr->status = be32_to_cpup(p++);
304 /* Ignore the tag */
305 length = be32_to_cpup(p++);
306 p = xdr_inline_decode(xdr, length + 4);
307 if (unlikely(p == NULL))
308 goto out_overflow;
309 p += XDR_QUADLEN(length);
310 hdr->nops = be32_to_cpup(p);
311 return 0;
312out_overflow:
313 return -EIO;
314}
315
316/*
317 * CB_RECALL4args
318 *
319 * struct CB_RECALL4args {
320 * stateid4 stateid;
321 * bool truncate;
322 * nfs_fh4 fh;
323 * };
324 */
325static void encode_cb_recall4args(struct xdr_stream *xdr,
326 const struct nfs4_delegation *dp,
327 struct nfs4_cb_compound_hdr *hdr)
328{
329 __be32 *p;
330
331 encode_nfs_cb_opnum4(xdr, OP_CB_RECALL);
332 encode_stateid4(xdr, &dp->dl_stid.sc_stateid);
333
334 p = xdr_reserve_space(xdr, 4);
335 *p++ = xdr_zero; /* truncate */
336
337 encode_nfs_fh4(xdr, &dp->dl_stid.sc_file->fi_fhandle);
338
339 hdr->nops++;
340}
341
342/*
343 * CB_RECALLANY4args
344 *
345 * struct CB_RECALLANY4args {
346 * uint32_t craa_objects_to_keep;
347 * bitmap4 craa_type_mask;
348 * };
349 */
350static void
351encode_cb_recallany4args(struct xdr_stream *xdr,
352 struct nfs4_cb_compound_hdr *hdr, struct nfsd4_cb_recall_any *ra)
353{
354 encode_nfs_cb_opnum4(xdr, OP_CB_RECALL_ANY);
355 encode_uint32(xdr, ra->ra_keep);
356 encode_bitmap4(xdr, ra->ra_bmval, ARRAY_SIZE(ra->ra_bmval));
357 hdr->nops++;
358}
359
360/*
361 * CB_SEQUENCE4args
362 *
363 * struct CB_SEQUENCE4args {
364 * sessionid4 csa_sessionid;
365 * sequenceid4 csa_sequenceid;
366 * slotid4 csa_slotid;
367 * slotid4 csa_highest_slotid;
368 * bool csa_cachethis;
369 * referring_call_list4 csa_referring_call_lists<>;
370 * };
371 */
372static void encode_cb_sequence4args(struct xdr_stream *xdr,
373 const struct nfsd4_callback *cb,
374 struct nfs4_cb_compound_hdr *hdr)
375{
376 struct nfsd4_session *session = cb->cb_clp->cl_cb_session;
377 __be32 *p;
378
379 if (hdr->minorversion == 0)
380 return;
381
382 encode_nfs_cb_opnum4(xdr, OP_CB_SEQUENCE);
383 encode_sessionid4(xdr, session);
384
385 p = xdr_reserve_space(xdr, 4 + 4 + 4 + 4 + 4);
386 *p++ = cpu_to_be32(session->se_cb_seq_nr); /* csa_sequenceid */
387 *p++ = xdr_zero; /* csa_slotid */
388 *p++ = xdr_zero; /* csa_highest_slotid */
389 *p++ = xdr_zero; /* csa_cachethis */
390 xdr_encode_empty_array(p); /* csa_referring_call_lists */
391
392 hdr->nops++;
393}
394
395/*
396 * CB_SEQUENCE4resok
397 *
398 * struct CB_SEQUENCE4resok {
399 * sessionid4 csr_sessionid;
400 * sequenceid4 csr_sequenceid;
401 * slotid4 csr_slotid;
402 * slotid4 csr_highest_slotid;
403 * slotid4 csr_target_highest_slotid;
404 * };
405 *
406 * union CB_SEQUENCE4res switch (nfsstat4 csr_status) {
407 * case NFS4_OK:
408 * CB_SEQUENCE4resok csr_resok4;
409 * default:
410 * void;
411 * };
412 *
413 * Our current back channel implmentation supports a single backchannel
414 * with a single slot.
415 */
416static int decode_cb_sequence4resok(struct xdr_stream *xdr,
417 struct nfsd4_callback *cb)
418{
419 struct nfsd4_session *session = cb->cb_clp->cl_cb_session;
420 int status = -ESERVERFAULT;
421 __be32 *p;
422 u32 dummy;
423
424 /*
425 * If the server returns different values for sessionID, slotID or
426 * sequence number, the server is looney tunes.
427 */
428 p = xdr_inline_decode(xdr, NFS4_MAX_SESSIONID_LEN + 4 + 4 + 4 + 4);
429 if (unlikely(p == NULL))
430 goto out_overflow;
431
432 if (memcmp(p, session->se_sessionid.data, NFS4_MAX_SESSIONID_LEN)) {
433 dprintk("NFS: %s Invalid session id\n", __func__);
434 goto out;
435 }
436 p += XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN);
437
438 dummy = be32_to_cpup(p++);
439 if (dummy != session->se_cb_seq_nr) {
440 dprintk("NFS: %s Invalid sequence number\n", __func__);
441 goto out;
442 }
443
444 dummy = be32_to_cpup(p++);
445 if (dummy != 0) {
446 dprintk("NFS: %s Invalid slotid\n", __func__);
447 goto out;
448 }
449
450 /*
451 * FIXME: process highest slotid and target highest slotid
452 */
453 status = 0;
454out:
455 cb->cb_seq_status = status;
456 return status;
457out_overflow:
458 status = -EIO;
459 goto out;
460}
461
462static int decode_cb_sequence4res(struct xdr_stream *xdr,
463 struct nfsd4_callback *cb)
464{
465 int status;
466
467 if (cb->cb_clp->cl_minorversion == 0)
468 return 0;
469
470 status = decode_cb_op_status(xdr, OP_CB_SEQUENCE, &cb->cb_seq_status);
471 if (unlikely(status || cb->cb_seq_status))
472 return status;
473
474 return decode_cb_sequence4resok(xdr, cb);
475}
476
477/*
478 * NFSv4.0 and NFSv4.1 XDR encode functions
479 *
480 * NFSv4.0 callback argument types are defined in section 15 of RFC
481 * 3530: "Network File System (NFS) version 4 Protocol" and section 20
482 * of RFC 5661: "Network File System (NFS) Version 4 Minor Version 1
483 * Protocol".
484 */
485
486/*
487 * NB: Without this zero space reservation, callbacks over krb5p fail
488 */
489static void nfs4_xdr_enc_cb_null(struct rpc_rqst *req, struct xdr_stream *xdr,
490 const void *__unused)
491{
492 xdr_reserve_space(xdr, 0);
493}
494
495/*
496 * 20.2. Operation 4: CB_RECALL - Recall a Delegation
497 */
498static void nfs4_xdr_enc_cb_recall(struct rpc_rqst *req, struct xdr_stream *xdr,
499 const void *data)
500{
501 const struct nfsd4_callback *cb = data;
502 const struct nfs4_delegation *dp = cb_to_delegation(cb);
503 struct nfs4_cb_compound_hdr hdr = {
504 .ident = cb->cb_clp->cl_cb_ident,
505 .minorversion = cb->cb_clp->cl_minorversion,
506 };
507
508 encode_cb_compound4args(xdr, &hdr);
509 encode_cb_sequence4args(xdr, cb, &hdr);
510 encode_cb_recall4args(xdr, dp, &hdr);
511 encode_cb_nops(&hdr);
512}
513
514/*
515 * 20.6. Operation 8: CB_RECALL_ANY - Keep Any N Recallable Objects
516 */
517static void
518nfs4_xdr_enc_cb_recall_any(struct rpc_rqst *req,
519 struct xdr_stream *xdr, const void *data)
520{
521 const struct nfsd4_callback *cb = data;
522 struct nfsd4_cb_recall_any *ra;
523 struct nfs4_cb_compound_hdr hdr = {
524 .ident = cb->cb_clp->cl_cb_ident,
525 .minorversion = cb->cb_clp->cl_minorversion,
526 };
527
528 ra = container_of(cb, struct nfsd4_cb_recall_any, ra_cb);
529 encode_cb_compound4args(xdr, &hdr);
530 encode_cb_sequence4args(xdr, cb, &hdr);
531 encode_cb_recallany4args(xdr, &hdr, ra);
532 encode_cb_nops(&hdr);
533}
534
535/*
536 * NFSv4.0 and NFSv4.1 XDR decode functions
537 *
538 * NFSv4.0 callback result types are defined in section 15 of RFC
539 * 3530: "Network File System (NFS) version 4 Protocol" and section 20
540 * of RFC 5661: "Network File System (NFS) Version 4 Minor Version 1
541 * Protocol".
542 */
543
544static int nfs4_xdr_dec_cb_null(struct rpc_rqst *req, struct xdr_stream *xdr,
545 void *__unused)
546{
547 return 0;
548}
549
550/*
551 * 20.2. Operation 4: CB_RECALL - Recall a Delegation
552 */
553static int nfs4_xdr_dec_cb_recall(struct rpc_rqst *rqstp,
554 struct xdr_stream *xdr,
555 void *data)
556{
557 struct nfsd4_callback *cb = data;
558 struct nfs4_cb_compound_hdr hdr;
559 int status;
560
561 status = decode_cb_compound4res(xdr, &hdr);
562 if (unlikely(status))
563 return status;
564
565 status = decode_cb_sequence4res(xdr, cb);
566 if (unlikely(status || cb->cb_seq_status))
567 return status;
568
569 return decode_cb_op_status(xdr, OP_CB_RECALL, &cb->cb_status);
570}
571
572/*
573 * 20.6. Operation 8: CB_RECALL_ANY - Keep Any N Recallable Objects
574 */
575static int
576nfs4_xdr_dec_cb_recall_any(struct rpc_rqst *rqstp,
577 struct xdr_stream *xdr,
578 void *data)
579{
580 struct nfsd4_callback *cb = data;
581 struct nfs4_cb_compound_hdr hdr;
582 int status;
583
584 status = decode_cb_compound4res(xdr, &hdr);
585 if (unlikely(status))
586 return status;
587 status = decode_cb_sequence4res(xdr, cb);
588 if (unlikely(status || cb->cb_seq_status))
589 return status;
590 status = decode_cb_op_status(xdr, OP_CB_RECALL_ANY, &cb->cb_status);
591 return status;
592}
593
594#ifdef CONFIG_NFSD_PNFS
595/*
596 * CB_LAYOUTRECALL4args
597 *
598 * struct layoutrecall_file4 {
599 * nfs_fh4 lor_fh;
600 * offset4 lor_offset;
601 * length4 lor_length;
602 * stateid4 lor_stateid;
603 * };
604 *
605 * union layoutrecall4 switch(layoutrecall_type4 lor_recalltype) {
606 * case LAYOUTRECALL4_FILE:
607 * layoutrecall_file4 lor_layout;
608 * case LAYOUTRECALL4_FSID:
609 * fsid4 lor_fsid;
610 * case LAYOUTRECALL4_ALL:
611 * void;
612 * };
613 *
614 * struct CB_LAYOUTRECALL4args {
615 * layouttype4 clora_type;
616 * layoutiomode4 clora_iomode;
617 * bool clora_changed;
618 * layoutrecall4 clora_recall;
619 * };
620 */
621static void encode_cb_layout4args(struct xdr_stream *xdr,
622 const struct nfs4_layout_stateid *ls,
623 struct nfs4_cb_compound_hdr *hdr)
624{
625 __be32 *p;
626
627 BUG_ON(hdr->minorversion == 0);
628
629 p = xdr_reserve_space(xdr, 5 * 4);
630 *p++ = cpu_to_be32(OP_CB_LAYOUTRECALL);
631 *p++ = cpu_to_be32(ls->ls_layout_type);
632 *p++ = cpu_to_be32(IOMODE_ANY);
633 *p++ = cpu_to_be32(1);
634 *p = cpu_to_be32(RETURN_FILE);
635
636 encode_nfs_fh4(xdr, &ls->ls_stid.sc_file->fi_fhandle);
637
638 p = xdr_reserve_space(xdr, 2 * 8);
639 p = xdr_encode_hyper(p, 0);
640 xdr_encode_hyper(p, NFS4_MAX_UINT64);
641
642 encode_stateid4(xdr, &ls->ls_recall_sid);
643
644 hdr->nops++;
645}
646
647static void nfs4_xdr_enc_cb_layout(struct rpc_rqst *req,
648 struct xdr_stream *xdr,
649 const void *data)
650{
651 const struct nfsd4_callback *cb = data;
652 const struct nfs4_layout_stateid *ls =
653 container_of(cb, struct nfs4_layout_stateid, ls_recall);
654 struct nfs4_cb_compound_hdr hdr = {
655 .ident = 0,
656 .minorversion = cb->cb_clp->cl_minorversion,
657 };
658
659 encode_cb_compound4args(xdr, &hdr);
660 encode_cb_sequence4args(xdr, cb, &hdr);
661 encode_cb_layout4args(xdr, ls, &hdr);
662 encode_cb_nops(&hdr);
663}
664
665static int nfs4_xdr_dec_cb_layout(struct rpc_rqst *rqstp,
666 struct xdr_stream *xdr,
667 void *data)
668{
669 struct nfsd4_callback *cb = data;
670 struct nfs4_cb_compound_hdr hdr;
671 int status;
672
673 status = decode_cb_compound4res(xdr, &hdr);
674 if (unlikely(status))
675 return status;
676
677 status = decode_cb_sequence4res(xdr, cb);
678 if (unlikely(status || cb->cb_seq_status))
679 return status;
680
681 return decode_cb_op_status(xdr, OP_CB_LAYOUTRECALL, &cb->cb_status);
682}
683#endif /* CONFIG_NFSD_PNFS */
684
685static void encode_stateowner(struct xdr_stream *xdr, struct nfs4_stateowner *so)
686{
687 __be32 *p;
688
689 p = xdr_reserve_space(xdr, 8 + 4 + so->so_owner.len);
690 p = xdr_encode_opaque_fixed(p, &so->so_client->cl_clientid, 8);
691 xdr_encode_opaque(p, so->so_owner.data, so->so_owner.len);
692}
693
694static void nfs4_xdr_enc_cb_notify_lock(struct rpc_rqst *req,
695 struct xdr_stream *xdr,
696 const void *data)
697{
698 const struct nfsd4_callback *cb = data;
699 const struct nfsd4_blocked_lock *nbl =
700 container_of(cb, struct nfsd4_blocked_lock, nbl_cb);
701 struct nfs4_lockowner *lo = (struct nfs4_lockowner *)nbl->nbl_lock.fl_owner;
702 struct nfs4_cb_compound_hdr hdr = {
703 .ident = 0,
704 .minorversion = cb->cb_clp->cl_minorversion,
705 };
706
707 __be32 *p;
708
709 BUG_ON(hdr.minorversion == 0);
710
711 encode_cb_compound4args(xdr, &hdr);
712 encode_cb_sequence4args(xdr, cb, &hdr);
713
714 p = xdr_reserve_space(xdr, 4);
715 *p = cpu_to_be32(OP_CB_NOTIFY_LOCK);
716 encode_nfs_fh4(xdr, &nbl->nbl_fh);
717 encode_stateowner(xdr, &lo->lo_owner);
718 hdr.nops++;
719
720 encode_cb_nops(&hdr);
721}
722
723static int nfs4_xdr_dec_cb_notify_lock(struct rpc_rqst *rqstp,
724 struct xdr_stream *xdr,
725 void *data)
726{
727 struct nfsd4_callback *cb = data;
728 struct nfs4_cb_compound_hdr hdr;
729 int status;
730
731 status = decode_cb_compound4res(xdr, &hdr);
732 if (unlikely(status))
733 return status;
734
735 status = decode_cb_sequence4res(xdr, cb);
736 if (unlikely(status || cb->cb_seq_status))
737 return status;
738
739 return decode_cb_op_status(xdr, OP_CB_NOTIFY_LOCK, &cb->cb_status);
740}
741
742/*
743 * struct write_response4 {
744 * stateid4 wr_callback_id<1>;
745 * length4 wr_count;
746 * stable_how4 wr_committed;
747 * verifier4 wr_writeverf;
748 * };
749 * union offload_info4 switch (nfsstat4 coa_status) {
750 * case NFS4_OK:
751 * write_response4 coa_resok4;
752 * default:
753 * length4 coa_bytes_copied;
754 * };
755 * struct CB_OFFLOAD4args {
756 * nfs_fh4 coa_fh;
757 * stateid4 coa_stateid;
758 * offload_info4 coa_offload_info;
759 * };
760 */
761static void encode_offload_info4(struct xdr_stream *xdr,
762 const struct nfsd4_cb_offload *cbo)
763{
764 __be32 *p;
765
766 p = xdr_reserve_space(xdr, 4);
767 *p = cbo->co_nfserr;
768 switch (cbo->co_nfserr) {
769 case nfs_ok:
770 p = xdr_reserve_space(xdr, 4 + 8 + 4 + NFS4_VERIFIER_SIZE);
771 p = xdr_encode_empty_array(p);
772 p = xdr_encode_hyper(p, cbo->co_res.wr_bytes_written);
773 *p++ = cpu_to_be32(cbo->co_res.wr_stable_how);
774 p = xdr_encode_opaque_fixed(p, cbo->co_res.wr_verifier.data,
775 NFS4_VERIFIER_SIZE);
776 break;
777 default:
778 p = xdr_reserve_space(xdr, 8);
779 /* We always return success if bytes were written */
780 p = xdr_encode_hyper(p, 0);
781 }
782}
783
784static void encode_cb_offload4args(struct xdr_stream *xdr,
785 const struct nfsd4_cb_offload *cbo,
786 struct nfs4_cb_compound_hdr *hdr)
787{
788 __be32 *p;
789
790 p = xdr_reserve_space(xdr, 4);
791 *p = cpu_to_be32(OP_CB_OFFLOAD);
792 encode_nfs_fh4(xdr, &cbo->co_fh);
793 encode_stateid4(xdr, &cbo->co_res.cb_stateid);
794 encode_offload_info4(xdr, cbo);
795
796 hdr->nops++;
797}
798
799static void nfs4_xdr_enc_cb_offload(struct rpc_rqst *req,
800 struct xdr_stream *xdr,
801 const void *data)
802{
803 const struct nfsd4_callback *cb = data;
804 const struct nfsd4_cb_offload *cbo =
805 container_of(cb, struct nfsd4_cb_offload, co_cb);
806 struct nfs4_cb_compound_hdr hdr = {
807 .ident = 0,
808 .minorversion = cb->cb_clp->cl_minorversion,
809 };
810
811 encode_cb_compound4args(xdr, &hdr);
812 encode_cb_sequence4args(xdr, cb, &hdr);
813 encode_cb_offload4args(xdr, cbo, &hdr);
814 encode_cb_nops(&hdr);
815}
816
817static int nfs4_xdr_dec_cb_offload(struct rpc_rqst *rqstp,
818 struct xdr_stream *xdr,
819 void *data)
820{
821 struct nfsd4_callback *cb = data;
822 struct nfs4_cb_compound_hdr hdr;
823 int status;
824
825 status = decode_cb_compound4res(xdr, &hdr);
826 if (unlikely(status))
827 return status;
828
829 status = decode_cb_sequence4res(xdr, cb);
830 if (unlikely(status || cb->cb_seq_status))
831 return status;
832
833 return decode_cb_op_status(xdr, OP_CB_OFFLOAD, &cb->cb_status);
834}
835/*
836 * RPC procedure tables
837 */
838#define PROC(proc, call, argtype, restype) \
839[NFSPROC4_CLNT_##proc] = { \
840 .p_proc = NFSPROC4_CB_##call, \
841 .p_encode = nfs4_xdr_enc_##argtype, \
842 .p_decode = nfs4_xdr_dec_##restype, \
843 .p_arglen = NFS4_enc_##argtype##_sz, \
844 .p_replen = NFS4_dec_##restype##_sz, \
845 .p_statidx = NFSPROC4_CB_##call, \
846 .p_name = #proc, \
847}
848
849static const struct rpc_procinfo nfs4_cb_procedures[] = {
850 PROC(CB_NULL, NULL, cb_null, cb_null),
851 PROC(CB_RECALL, COMPOUND, cb_recall, cb_recall),
852#ifdef CONFIG_NFSD_PNFS
853 PROC(CB_LAYOUT, COMPOUND, cb_layout, cb_layout),
854#endif
855 PROC(CB_NOTIFY_LOCK, COMPOUND, cb_notify_lock, cb_notify_lock),
856 PROC(CB_OFFLOAD, COMPOUND, cb_offload, cb_offload),
857 PROC(CB_RECALL_ANY, COMPOUND, cb_recall_any, cb_recall_any),
858};
859
860static unsigned int nfs4_cb_counts[ARRAY_SIZE(nfs4_cb_procedures)];
861static const struct rpc_version nfs_cb_version4 = {
862/*
863 * Note on the callback rpc program version number: despite language in rfc
864 * 5661 section 18.36.3 requiring servers to use 4 in this field, the
865 * official xdr descriptions for both 4.0 and 4.1 specify version 1, and
866 * in practice that appears to be what implementations use. The section
867 * 18.36.3 language is expected to be fixed in an erratum.
868 */
869 .number = 1,
870 .nrprocs = ARRAY_SIZE(nfs4_cb_procedures),
871 .procs = nfs4_cb_procedures,
872 .counts = nfs4_cb_counts,
873};
874
875static const struct rpc_version *nfs_cb_version[2] = {
876 [1] = &nfs_cb_version4,
877};
878
879static const struct rpc_program cb_program;
880
881static struct rpc_stat cb_stats = {
882 .program = &cb_program
883};
884
885#define NFS4_CALLBACK 0x40000000
886static const struct rpc_program cb_program = {
887 .name = "nfs4_cb",
888 .number = NFS4_CALLBACK,
889 .nrvers = ARRAY_SIZE(nfs_cb_version),
890 .version = nfs_cb_version,
891 .stats = &cb_stats,
892 .pipe_dir_name = "nfsd4_cb",
893};
894
895static int max_cb_time(struct net *net)
896{
897 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
898
899 /*
900 * nfsd4_lease is set to at most one hour in __nfsd4_write_time,
901 * so we can use 32-bit math on it. Warn if that assumption
902 * ever stops being true.
903 */
904 if (WARN_ON_ONCE(nn->nfsd4_lease > 3600))
905 return 360 * HZ;
906
907 return max(((u32)nn->nfsd4_lease)/10, 1u) * HZ;
908}
909
910static struct workqueue_struct *callback_wq;
911
912static bool nfsd4_queue_cb(struct nfsd4_callback *cb)
913{
914 return queue_work(callback_wq, &cb->cb_work);
915}
916
917static void nfsd41_cb_inflight_begin(struct nfs4_client *clp)
918{
919 atomic_inc(&clp->cl_cb_inflight);
920}
921
922static void nfsd41_cb_inflight_end(struct nfs4_client *clp)
923{
924
925 if (atomic_dec_and_test(&clp->cl_cb_inflight))
926 wake_up_var(&clp->cl_cb_inflight);
927}
928
929static void nfsd41_cb_inflight_wait_complete(struct nfs4_client *clp)
930{
931 wait_var_event(&clp->cl_cb_inflight,
932 !atomic_read(&clp->cl_cb_inflight));
933}
934
935static const struct cred *get_backchannel_cred(struct nfs4_client *clp, struct rpc_clnt *client, struct nfsd4_session *ses)
936{
937 if (clp->cl_minorversion == 0) {
938 client->cl_principal = clp->cl_cred.cr_targ_princ ?
939 clp->cl_cred.cr_targ_princ : "nfs";
940
941 return get_cred(rpc_machine_cred());
942 } else {
943 struct cred *kcred;
944
945 kcred = prepare_kernel_cred(&init_task);
946 if (!kcred)
947 return NULL;
948
949 kcred->uid = ses->se_cb_sec.uid;
950 kcred->gid = ses->se_cb_sec.gid;
951 return kcred;
952 }
953}
954
955static int setup_callback_client(struct nfs4_client *clp, struct nfs4_cb_conn *conn, struct nfsd4_session *ses)
956{
957 int maxtime = max_cb_time(clp->net);
958 struct rpc_timeout timeparms = {
959 .to_initval = maxtime,
960 .to_retries = 0,
961 .to_maxval = maxtime,
962 };
963 struct rpc_create_args args = {
964 .net = clp->net,
965 .address = (struct sockaddr *) &conn->cb_addr,
966 .addrsize = conn->cb_addrlen,
967 .saddress = (struct sockaddr *) &conn->cb_saddr,
968 .timeout = &timeparms,
969 .program = &cb_program,
970 .version = 1,
971 .flags = (RPC_CLNT_CREATE_NOPING | RPC_CLNT_CREATE_QUIET),
972 .cred = current_cred(),
973 };
974 struct rpc_clnt *client;
975 const struct cred *cred;
976
977 if (clp->cl_minorversion == 0) {
978 if (!clp->cl_cred.cr_principal &&
979 (clp->cl_cred.cr_flavor >= RPC_AUTH_GSS_KRB5)) {
980 trace_nfsd_cb_setup_err(clp, -EINVAL);
981 return -EINVAL;
982 }
983 args.client_name = clp->cl_cred.cr_principal;
984 args.prognumber = conn->cb_prog;
985 args.protocol = XPRT_TRANSPORT_TCP;
986 args.authflavor = clp->cl_cred.cr_flavor;
987 clp->cl_cb_ident = conn->cb_ident;
988 } else {
989 if (!conn->cb_xprt)
990 return -EINVAL;
991 clp->cl_cb_session = ses;
992 args.bc_xprt = conn->cb_xprt;
993 args.prognumber = clp->cl_cb_session->se_cb_prog;
994 args.protocol = conn->cb_xprt->xpt_class->xcl_ident |
995 XPRT_TRANSPORT_BC;
996 args.authflavor = ses->se_cb_sec.flavor;
997 }
998 /* Create RPC client */
999 client = rpc_create(&args);
1000 if (IS_ERR(client)) {
1001 trace_nfsd_cb_setup_err(clp, PTR_ERR(client));
1002 return PTR_ERR(client);
1003 }
1004 cred = get_backchannel_cred(clp, client, ses);
1005 if (!cred) {
1006 trace_nfsd_cb_setup_err(clp, -ENOMEM);
1007 rpc_shutdown_client(client);
1008 return -ENOMEM;
1009 }
1010
1011 if (clp->cl_minorversion != 0)
1012 clp->cl_cb_conn.cb_xprt = conn->cb_xprt;
1013 clp->cl_cb_client = client;
1014 clp->cl_cb_cred = cred;
1015 rcu_read_lock();
1016 trace_nfsd_cb_setup(clp, rpc_peeraddr2str(client, RPC_DISPLAY_NETID),
1017 args.authflavor);
1018 rcu_read_unlock();
1019 return 0;
1020}
1021
1022static void nfsd4_mark_cb_state(struct nfs4_client *clp, int newstate)
1023{
1024 if (clp->cl_cb_state != newstate) {
1025 clp->cl_cb_state = newstate;
1026 trace_nfsd_cb_state(clp);
1027 }
1028}
1029
1030static void nfsd4_mark_cb_down(struct nfs4_client *clp, int reason)
1031{
1032 if (test_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags))
1033 return;
1034 nfsd4_mark_cb_state(clp, NFSD4_CB_DOWN);
1035}
1036
1037static void nfsd4_mark_cb_fault(struct nfs4_client *clp, int reason)
1038{
1039 if (test_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags))
1040 return;
1041 nfsd4_mark_cb_state(clp, NFSD4_CB_FAULT);
1042}
1043
1044static void nfsd4_cb_probe_done(struct rpc_task *task, void *calldata)
1045{
1046 struct nfs4_client *clp = container_of(calldata, struct nfs4_client, cl_cb_null);
1047
1048 if (task->tk_status)
1049 nfsd4_mark_cb_down(clp, task->tk_status);
1050 else
1051 nfsd4_mark_cb_state(clp, NFSD4_CB_UP);
1052}
1053
1054static void nfsd4_cb_probe_release(void *calldata)
1055{
1056 struct nfs4_client *clp = container_of(calldata, struct nfs4_client, cl_cb_null);
1057
1058 nfsd41_cb_inflight_end(clp);
1059
1060}
1061
1062static const struct rpc_call_ops nfsd4_cb_probe_ops = {
1063 /* XXX: release method to ensure we set the cb channel down if
1064 * necessary on early failure? */
1065 .rpc_call_done = nfsd4_cb_probe_done,
1066 .rpc_release = nfsd4_cb_probe_release,
1067};
1068
1069/*
1070 * Poke the callback thread to process any updates to the callback
1071 * parameters, and send a null probe.
1072 */
1073void nfsd4_probe_callback(struct nfs4_client *clp)
1074{
1075 trace_nfsd_cb_probe(clp);
1076 nfsd4_mark_cb_state(clp, NFSD4_CB_UNKNOWN);
1077 set_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags);
1078 nfsd4_run_cb(&clp->cl_cb_null);
1079}
1080
1081void nfsd4_probe_callback_sync(struct nfs4_client *clp)
1082{
1083 nfsd4_probe_callback(clp);
1084 flush_workqueue(callback_wq);
1085}
1086
1087void nfsd4_change_callback(struct nfs4_client *clp, struct nfs4_cb_conn *conn)
1088{
1089 nfsd4_mark_cb_state(clp, NFSD4_CB_UNKNOWN);
1090 spin_lock(&clp->cl_lock);
1091 memcpy(&clp->cl_cb_conn, conn, sizeof(struct nfs4_cb_conn));
1092 spin_unlock(&clp->cl_lock);
1093}
1094
1095/*
1096 * There's currently a single callback channel slot.
1097 * If the slot is available, then mark it busy. Otherwise, set the
1098 * thread for sleeping on the callback RPC wait queue.
1099 */
1100static bool nfsd41_cb_get_slot(struct nfsd4_callback *cb, struct rpc_task *task)
1101{
1102 struct nfs4_client *clp = cb->cb_clp;
1103
1104 if (!cb->cb_holds_slot &&
1105 test_and_set_bit(0, &clp->cl_cb_slot_busy) != 0) {
1106 rpc_sleep_on(&clp->cl_cb_waitq, task, NULL);
1107 /* Race breaker */
1108 if (test_and_set_bit(0, &clp->cl_cb_slot_busy) != 0) {
1109 dprintk("%s slot is busy\n", __func__);
1110 return false;
1111 }
1112 rpc_wake_up_queued_task(&clp->cl_cb_waitq, task);
1113 }
1114 cb->cb_holds_slot = true;
1115 return true;
1116}
1117
1118static void nfsd41_cb_release_slot(struct nfsd4_callback *cb)
1119{
1120 struct nfs4_client *clp = cb->cb_clp;
1121
1122 if (cb->cb_holds_slot) {
1123 cb->cb_holds_slot = false;
1124 clear_bit(0, &clp->cl_cb_slot_busy);
1125 rpc_wake_up_next(&clp->cl_cb_waitq);
1126 }
1127}
1128
1129static void nfsd41_destroy_cb(struct nfsd4_callback *cb)
1130{
1131 struct nfs4_client *clp = cb->cb_clp;
1132
1133 nfsd41_cb_release_slot(cb);
1134 if (cb->cb_ops && cb->cb_ops->release)
1135 cb->cb_ops->release(cb);
1136 nfsd41_cb_inflight_end(clp);
1137}
1138
1139/*
1140 * TODO: cb_sequence should support referring call lists, cachethis, multiple
1141 * slots, and mark callback channel down on communication errors.
1142 */
1143static void nfsd4_cb_prepare(struct rpc_task *task, void *calldata)
1144{
1145 struct nfsd4_callback *cb = calldata;
1146 struct nfs4_client *clp = cb->cb_clp;
1147 u32 minorversion = clp->cl_minorversion;
1148
1149 /*
1150 * cb_seq_status is only set in decode_cb_sequence4res,
1151 * and so will remain 1 if an rpc level failure occurs.
1152 */
1153 cb->cb_seq_status = 1;
1154 cb->cb_status = 0;
1155 if (minorversion && !nfsd41_cb_get_slot(cb, task))
1156 return;
1157 rpc_call_start(task);
1158}
1159
1160static bool nfsd4_cb_sequence_done(struct rpc_task *task, struct nfsd4_callback *cb)
1161{
1162 struct nfs4_client *clp = cb->cb_clp;
1163 struct nfsd4_session *session = clp->cl_cb_session;
1164 bool ret = true;
1165
1166 if (!clp->cl_minorversion) {
1167 /*
1168 * If the backchannel connection was shut down while this
1169 * task was queued, we need to resubmit it after setting up
1170 * a new backchannel connection.
1171 *
1172 * Note that if we lost our callback connection permanently
1173 * the submission code will error out, so we don't need to
1174 * handle that case here.
1175 */
1176 if (RPC_SIGNALLED(task))
1177 goto need_restart;
1178
1179 return true;
1180 }
1181
1182 if (!cb->cb_holds_slot)
1183 goto need_restart;
1184
1185 switch (cb->cb_seq_status) {
1186 case 0:
1187 /*
1188 * No need for lock, access serialized in nfsd4_cb_prepare
1189 *
1190 * RFC5661 20.9.3
1191 * If CB_SEQUENCE returns an error, then the state of the slot
1192 * (sequence ID, cached reply) MUST NOT change.
1193 */
1194 ++session->se_cb_seq_nr;
1195 break;
1196 case -ESERVERFAULT:
1197 ++session->se_cb_seq_nr;
1198 fallthrough;
1199 case 1:
1200 case -NFS4ERR_BADSESSION:
1201 nfsd4_mark_cb_fault(cb->cb_clp, cb->cb_seq_status);
1202 ret = false;
1203 break;
1204 case -NFS4ERR_DELAY:
1205 if (!rpc_restart_call(task))
1206 goto out;
1207
1208 rpc_delay(task, 2 * HZ);
1209 return false;
1210 case -NFS4ERR_BADSLOT:
1211 goto retry_nowait;
1212 case -NFS4ERR_SEQ_MISORDERED:
1213 if (session->se_cb_seq_nr != 1) {
1214 session->se_cb_seq_nr = 1;
1215 goto retry_nowait;
1216 }
1217 break;
1218 default:
1219 nfsd4_mark_cb_fault(cb->cb_clp, cb->cb_seq_status);
1220 dprintk("%s: unprocessed error %d\n", __func__,
1221 cb->cb_seq_status);
1222 }
1223
1224 nfsd41_cb_release_slot(cb);
1225 dprintk("%s: freed slot, new seqid=%d\n", __func__,
1226 clp->cl_cb_session->se_cb_seq_nr);
1227
1228 if (RPC_SIGNALLED(task))
1229 goto need_restart;
1230out:
1231 return ret;
1232retry_nowait:
1233 if (rpc_restart_call_prepare(task))
1234 ret = false;
1235 goto out;
1236need_restart:
1237 if (!test_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags)) {
1238 task->tk_status = 0;
1239 cb->cb_need_restart = true;
1240 }
1241 return false;
1242}
1243
1244static void nfsd4_cb_done(struct rpc_task *task, void *calldata)
1245{
1246 struct nfsd4_callback *cb = calldata;
1247 struct nfs4_client *clp = cb->cb_clp;
1248
1249 if (!nfsd4_cb_sequence_done(task, cb))
1250 return;
1251
1252 if (cb->cb_status) {
1253 WARN_ON_ONCE(task->tk_status);
1254 task->tk_status = cb->cb_status;
1255 }
1256
1257 switch (cb->cb_ops->done(cb, task)) {
1258 case 0:
1259 task->tk_status = 0;
1260 rpc_restart_call_prepare(task);
1261 return;
1262 case 1:
1263 switch (task->tk_status) {
1264 case -EIO:
1265 case -ETIMEDOUT:
1266 case -EACCES:
1267 nfsd4_mark_cb_down(clp, task->tk_status);
1268 }
1269 break;
1270 default:
1271 BUG();
1272 }
1273}
1274
1275static void nfsd4_cb_release(void *calldata)
1276{
1277 struct nfsd4_callback *cb = calldata;
1278
1279 if (cb->cb_need_restart)
1280 nfsd4_queue_cb(cb);
1281 else
1282 nfsd41_destroy_cb(cb);
1283
1284}
1285
1286static const struct rpc_call_ops nfsd4_cb_ops = {
1287 .rpc_call_prepare = nfsd4_cb_prepare,
1288 .rpc_call_done = nfsd4_cb_done,
1289 .rpc_release = nfsd4_cb_release,
1290};
1291
1292int nfsd4_create_callback_queue(void)
1293{
1294 callback_wq = alloc_ordered_workqueue("nfsd4_callbacks", 0);
1295 if (!callback_wq)
1296 return -ENOMEM;
1297 return 0;
1298}
1299
1300void nfsd4_destroy_callback_queue(void)
1301{
1302 destroy_workqueue(callback_wq);
1303}
1304
1305/* must be called under the state lock */
1306void nfsd4_shutdown_callback(struct nfs4_client *clp)
1307{
1308 if (clp->cl_cb_state != NFSD4_CB_UNKNOWN)
1309 trace_nfsd_cb_shutdown(clp);
1310
1311 set_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags);
1312 /*
1313 * Note this won't actually result in a null callback;
1314 * instead, nfsd4_run_cb_null() will detect the killed
1315 * client, destroy the rpc client, and stop:
1316 */
1317 nfsd4_run_cb(&clp->cl_cb_null);
1318 flush_workqueue(callback_wq);
1319 nfsd41_cb_inflight_wait_complete(clp);
1320}
1321
1322/* requires cl_lock: */
1323static struct nfsd4_conn * __nfsd4_find_backchannel(struct nfs4_client *clp)
1324{
1325 struct nfsd4_session *s;
1326 struct nfsd4_conn *c;
1327
1328 list_for_each_entry(s, &clp->cl_sessions, se_perclnt) {
1329 list_for_each_entry(c, &s->se_conns, cn_persession) {
1330 if (c->cn_flags & NFS4_CDFC4_BACK)
1331 return c;
1332 }
1333 }
1334 return NULL;
1335}
1336
1337/*
1338 * Note there isn't a lot of locking in this code; instead we depend on
1339 * the fact that it is run from the callback_wq, which won't run two
1340 * work items at once. So, for example, callback_wq handles all access
1341 * of cl_cb_client and all calls to rpc_create or rpc_shutdown_client.
1342 */
1343static void nfsd4_process_cb_update(struct nfsd4_callback *cb)
1344{
1345 struct nfs4_cb_conn conn;
1346 struct nfs4_client *clp = cb->cb_clp;
1347 struct nfsd4_session *ses = NULL;
1348 struct nfsd4_conn *c;
1349 int err;
1350
1351 /*
1352 * This is either an update, or the client dying; in either case,
1353 * kill the old client:
1354 */
1355 if (clp->cl_cb_client) {
1356 rpc_shutdown_client(clp->cl_cb_client);
1357 clp->cl_cb_client = NULL;
1358 put_cred(clp->cl_cb_cred);
1359 clp->cl_cb_cred = NULL;
1360 }
1361 if (clp->cl_cb_conn.cb_xprt) {
1362 svc_xprt_put(clp->cl_cb_conn.cb_xprt);
1363 clp->cl_cb_conn.cb_xprt = NULL;
1364 }
1365 if (test_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags))
1366 return;
1367 spin_lock(&clp->cl_lock);
1368 /*
1369 * Only serialized callback code is allowed to clear these
1370 * flags; main nfsd code can only set them:
1371 */
1372 BUG_ON(!(clp->cl_flags & NFSD4_CLIENT_CB_FLAG_MASK));
1373 clear_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags);
1374 memcpy(&conn, &cb->cb_clp->cl_cb_conn, sizeof(struct nfs4_cb_conn));
1375 c = __nfsd4_find_backchannel(clp);
1376 if (c) {
1377 svc_xprt_get(c->cn_xprt);
1378 conn.cb_xprt = c->cn_xprt;
1379 ses = c->cn_session;
1380 }
1381 spin_unlock(&clp->cl_lock);
1382
1383 err = setup_callback_client(clp, &conn, ses);
1384 if (err) {
1385 nfsd4_mark_cb_down(clp, err);
1386 if (c)
1387 svc_xprt_put(c->cn_xprt);
1388 return;
1389 }
1390}
1391
1392static void
1393nfsd4_run_cb_work(struct work_struct *work)
1394{
1395 struct nfsd4_callback *cb =
1396 container_of(work, struct nfsd4_callback, cb_work);
1397 struct nfs4_client *clp = cb->cb_clp;
1398 struct rpc_clnt *clnt;
1399 int flags;
1400
1401 if (cb->cb_need_restart) {
1402 cb->cb_need_restart = false;
1403 } else {
1404 if (cb->cb_ops && cb->cb_ops->prepare)
1405 cb->cb_ops->prepare(cb);
1406 }
1407
1408 if (clp->cl_flags & NFSD4_CLIENT_CB_FLAG_MASK)
1409 nfsd4_process_cb_update(cb);
1410
1411 clnt = clp->cl_cb_client;
1412 if (!clnt) {
1413 /* Callback channel broken, or client killed; give up: */
1414 nfsd41_destroy_cb(cb);
1415 return;
1416 }
1417
1418 /*
1419 * Don't send probe messages for 4.1 or later.
1420 */
1421 if (!cb->cb_ops && clp->cl_minorversion) {
1422 nfsd4_mark_cb_state(clp, NFSD4_CB_UP);
1423 nfsd41_destroy_cb(cb);
1424 return;
1425 }
1426
1427 cb->cb_msg.rpc_cred = clp->cl_cb_cred;
1428 flags = clp->cl_minorversion ? RPC_TASK_NOCONNECT : RPC_TASK_SOFTCONN;
1429 rpc_call_async(clnt, &cb->cb_msg, RPC_TASK_SOFT | flags,
1430 cb->cb_ops ? &nfsd4_cb_ops : &nfsd4_cb_probe_ops, cb);
1431}
1432
1433void nfsd4_init_cb(struct nfsd4_callback *cb, struct nfs4_client *clp,
1434 const struct nfsd4_callback_ops *ops, enum nfsd4_cb_op op)
1435{
1436 cb->cb_clp = clp;
1437 cb->cb_msg.rpc_proc = &nfs4_cb_procedures[op];
1438 cb->cb_msg.rpc_argp = cb;
1439 cb->cb_msg.rpc_resp = cb;
1440 cb->cb_ops = ops;
1441 INIT_WORK(&cb->cb_work, nfsd4_run_cb_work);
1442 cb->cb_seq_status = 1;
1443 cb->cb_status = 0;
1444 cb->cb_need_restart = false;
1445 cb->cb_holds_slot = false;
1446}
1447
1448/**
1449 * nfsd4_run_cb - queue up a callback job to run
1450 * @cb: callback to queue
1451 *
1452 * Kick off a callback to do its thing. Returns false if it was already
1453 * on a queue, true otherwise.
1454 */
1455bool nfsd4_run_cb(struct nfsd4_callback *cb)
1456{
1457 struct nfs4_client *clp = cb->cb_clp;
1458 bool queued;
1459
1460 nfsd41_cb_inflight_begin(clp);
1461 queued = nfsd4_queue_cb(cb);
1462 if (!queued)
1463 nfsd41_cb_inflight_end(clp);
1464 return queued;
1465}
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/nfs4.h>
35#include <linux/sunrpc/clnt.h>
36#include <linux/sunrpc/xprt.h>
37#include <linux/sunrpc/svc_xprt.h>
38#include <linux/slab.h>
39#include "nfsd.h"
40#include "state.h"
41#include "netns.h"
42#include "trace.h"
43#include "xdr4cb.h"
44#include "xdr4.h"
45
46#define NFSDDBG_FACILITY NFSDDBG_PROC
47
48static void nfsd4_mark_cb_fault(struct nfs4_client *, int reason);
49
50#define NFSPROC4_CB_NULL 0
51#define NFSPROC4_CB_COMPOUND 1
52
53/* Index of predefined Linux callback client operations */
54
55struct nfs4_cb_compound_hdr {
56 /* args */
57 u32 ident; /* minorversion 0 only */
58 u32 nops;
59 __be32 *nops_p;
60 u32 minorversion;
61 /* res */
62 int status;
63};
64
65static __be32 *xdr_encode_empty_array(__be32 *p)
66{
67 *p++ = xdr_zero;
68 return p;
69}
70
71/*
72 * Encode/decode NFSv4 CB basic data types
73 *
74 * Basic NFSv4 callback data types are defined in section 15 of RFC
75 * 3530: "Network File System (NFS) version 4 Protocol" and section
76 * 20 of RFC 5661: "Network File System (NFS) Version 4 Minor Version
77 * 1 Protocol"
78 */
79
80static void encode_uint32(struct xdr_stream *xdr, u32 n)
81{
82 WARN_ON_ONCE(xdr_stream_encode_u32(xdr, n) < 0);
83}
84
85static void encode_bitmap4(struct xdr_stream *xdr, const __u32 *bitmap,
86 size_t len)
87{
88 WARN_ON_ONCE(xdr_stream_encode_uint32_array(xdr, bitmap, len) < 0);
89}
90
91static void encode_nfs_cb_opnum4(struct xdr_stream *xdr, enum nfs_cb_opnum4 op)
92{
93 __be32 *p;
94
95 p = xdr_reserve_space(xdr, 4);
96 *p = cpu_to_be32(op);
97}
98
99/*
100 * nfs_fh4
101 *
102 * typedef opaque nfs_fh4<NFS4_FHSIZE>;
103 */
104static void encode_nfs_fh4(struct xdr_stream *xdr, const struct knfsd_fh *fh)
105{
106 u32 length = fh->fh_size;
107 __be32 *p;
108
109 BUG_ON(length > NFS4_FHSIZE);
110 p = xdr_reserve_space(xdr, 4 + length);
111 xdr_encode_opaque(p, &fh->fh_raw, length);
112}
113
114/*
115 * stateid4
116 *
117 * struct stateid4 {
118 * uint32_t seqid;
119 * opaque other[12];
120 * };
121 */
122static void encode_stateid4(struct xdr_stream *xdr, const stateid_t *sid)
123{
124 __be32 *p;
125
126 p = xdr_reserve_space(xdr, NFS4_STATEID_SIZE);
127 *p++ = cpu_to_be32(sid->si_generation);
128 xdr_encode_opaque_fixed(p, &sid->si_opaque, NFS4_STATEID_OTHER_SIZE);
129}
130
131/*
132 * sessionid4
133 *
134 * typedef opaque sessionid4[NFS4_SESSIONID_SIZE];
135 */
136static void encode_sessionid4(struct xdr_stream *xdr,
137 const struct nfsd4_session *session)
138{
139 __be32 *p;
140
141 p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN);
142 xdr_encode_opaque_fixed(p, session->se_sessionid.data,
143 NFS4_MAX_SESSIONID_LEN);
144}
145
146/*
147 * nfsstat4
148 */
149static const struct {
150 int stat;
151 int errno;
152} nfs_cb_errtbl[] = {
153 { NFS4_OK, 0 },
154 { NFS4ERR_PERM, -EPERM },
155 { NFS4ERR_NOENT, -ENOENT },
156 { NFS4ERR_IO, -EIO },
157 { NFS4ERR_NXIO, -ENXIO },
158 { NFS4ERR_ACCESS, -EACCES },
159 { NFS4ERR_EXIST, -EEXIST },
160 { NFS4ERR_XDEV, -EXDEV },
161 { NFS4ERR_NOTDIR, -ENOTDIR },
162 { NFS4ERR_ISDIR, -EISDIR },
163 { NFS4ERR_INVAL, -EINVAL },
164 { NFS4ERR_FBIG, -EFBIG },
165 { NFS4ERR_NOSPC, -ENOSPC },
166 { NFS4ERR_ROFS, -EROFS },
167 { NFS4ERR_MLINK, -EMLINK },
168 { NFS4ERR_NAMETOOLONG, -ENAMETOOLONG },
169 { NFS4ERR_NOTEMPTY, -ENOTEMPTY },
170 { NFS4ERR_DQUOT, -EDQUOT },
171 { NFS4ERR_STALE, -ESTALE },
172 { NFS4ERR_BADHANDLE, -EBADHANDLE },
173 { NFS4ERR_BAD_COOKIE, -EBADCOOKIE },
174 { NFS4ERR_NOTSUPP, -ENOTSUPP },
175 { NFS4ERR_TOOSMALL, -ETOOSMALL },
176 { NFS4ERR_SERVERFAULT, -ESERVERFAULT },
177 { NFS4ERR_BADTYPE, -EBADTYPE },
178 { NFS4ERR_LOCKED, -EAGAIN },
179 { NFS4ERR_RESOURCE, -EREMOTEIO },
180 { NFS4ERR_SYMLINK, -ELOOP },
181 { NFS4ERR_OP_ILLEGAL, -EOPNOTSUPP },
182 { NFS4ERR_DEADLOCK, -EDEADLK },
183 { -1, -EIO }
184};
185
186/*
187 * If we cannot translate the error, the recovery routines should
188 * handle it.
189 *
190 * Note: remaining NFSv4 error codes have values > 10000, so should
191 * not conflict with native Linux error codes.
192 */
193static int nfs_cb_stat_to_errno(int status)
194{
195 int i;
196
197 for (i = 0; nfs_cb_errtbl[i].stat != -1; i++) {
198 if (nfs_cb_errtbl[i].stat == status)
199 return nfs_cb_errtbl[i].errno;
200 }
201
202 dprintk("NFSD: Unrecognized NFS CB status value: %u\n", status);
203 return -status;
204}
205
206static int decode_cb_op_status(struct xdr_stream *xdr,
207 enum nfs_cb_opnum4 expected, int *status)
208{
209 __be32 *p;
210 u32 op;
211
212 p = xdr_inline_decode(xdr, 4 + 4);
213 if (unlikely(p == NULL))
214 goto out_overflow;
215 op = be32_to_cpup(p++);
216 if (unlikely(op != expected))
217 goto out_unexpected;
218 *status = nfs_cb_stat_to_errno(be32_to_cpup(p));
219 return 0;
220out_overflow:
221 return -EIO;
222out_unexpected:
223 dprintk("NFSD: Callback server returned operation %d but "
224 "we issued a request for %d\n", op, expected);
225 return -EIO;
226}
227
228/*
229 * CB_COMPOUND4args
230 *
231 * struct CB_COMPOUND4args {
232 * utf8str_cs tag;
233 * uint32_t minorversion;
234 * uint32_t callback_ident;
235 * nfs_cb_argop4 argarray<>;
236 * };
237*/
238static void encode_cb_compound4args(struct xdr_stream *xdr,
239 struct nfs4_cb_compound_hdr *hdr)
240{
241 __be32 * p;
242
243 p = xdr_reserve_space(xdr, 4 + 4 + 4 + 4);
244 p = xdr_encode_empty_array(p); /* empty tag */
245 *p++ = cpu_to_be32(hdr->minorversion);
246 *p++ = cpu_to_be32(hdr->ident);
247
248 hdr->nops_p = p;
249 *p = cpu_to_be32(hdr->nops); /* argarray element count */
250}
251
252/*
253 * Update argarray element count
254 */
255static void encode_cb_nops(struct nfs4_cb_compound_hdr *hdr)
256{
257 BUG_ON(hdr->nops > NFS4_MAX_BACK_CHANNEL_OPS);
258 *hdr->nops_p = cpu_to_be32(hdr->nops);
259}
260
261/*
262 * CB_COMPOUND4res
263 *
264 * struct CB_COMPOUND4res {
265 * nfsstat4 status;
266 * utf8str_cs tag;
267 * nfs_cb_resop4 resarray<>;
268 * };
269 */
270static int decode_cb_compound4res(struct xdr_stream *xdr,
271 struct nfs4_cb_compound_hdr *hdr)
272{
273 u32 length;
274 __be32 *p;
275
276 p = xdr_inline_decode(xdr, 4 + 4);
277 if (unlikely(p == NULL))
278 goto out_overflow;
279 hdr->status = be32_to_cpup(p++);
280 /* Ignore the tag */
281 length = be32_to_cpup(p++);
282 p = xdr_inline_decode(xdr, length + 4);
283 if (unlikely(p == NULL))
284 goto out_overflow;
285 p += XDR_QUADLEN(length);
286 hdr->nops = be32_to_cpup(p);
287 return 0;
288out_overflow:
289 return -EIO;
290}
291
292/*
293 * CB_RECALL4args
294 *
295 * struct CB_RECALL4args {
296 * stateid4 stateid;
297 * bool truncate;
298 * nfs_fh4 fh;
299 * };
300 */
301static void encode_cb_recall4args(struct xdr_stream *xdr,
302 const struct nfs4_delegation *dp,
303 struct nfs4_cb_compound_hdr *hdr)
304{
305 __be32 *p;
306
307 encode_nfs_cb_opnum4(xdr, OP_CB_RECALL);
308 encode_stateid4(xdr, &dp->dl_stid.sc_stateid);
309
310 p = xdr_reserve_space(xdr, 4);
311 *p++ = xdr_zero; /* truncate */
312
313 encode_nfs_fh4(xdr, &dp->dl_stid.sc_file->fi_fhandle);
314
315 hdr->nops++;
316}
317
318/*
319 * CB_RECALLANY4args
320 *
321 * struct CB_RECALLANY4args {
322 * uint32_t craa_objects_to_keep;
323 * bitmap4 craa_type_mask;
324 * };
325 */
326static void
327encode_cb_recallany4args(struct xdr_stream *xdr,
328 struct nfs4_cb_compound_hdr *hdr, struct nfsd4_cb_recall_any *ra)
329{
330 encode_nfs_cb_opnum4(xdr, OP_CB_RECALL_ANY);
331 encode_uint32(xdr, ra->ra_keep);
332 encode_bitmap4(xdr, ra->ra_bmval, ARRAY_SIZE(ra->ra_bmval));
333 hdr->nops++;
334}
335
336/*
337 * CB_SEQUENCE4args
338 *
339 * struct CB_SEQUENCE4args {
340 * sessionid4 csa_sessionid;
341 * sequenceid4 csa_sequenceid;
342 * slotid4 csa_slotid;
343 * slotid4 csa_highest_slotid;
344 * bool csa_cachethis;
345 * referring_call_list4 csa_referring_call_lists<>;
346 * };
347 */
348static void encode_cb_sequence4args(struct xdr_stream *xdr,
349 const struct nfsd4_callback *cb,
350 struct nfs4_cb_compound_hdr *hdr)
351{
352 struct nfsd4_session *session = cb->cb_clp->cl_cb_session;
353 __be32 *p;
354
355 if (hdr->minorversion == 0)
356 return;
357
358 encode_nfs_cb_opnum4(xdr, OP_CB_SEQUENCE);
359 encode_sessionid4(xdr, session);
360
361 p = xdr_reserve_space(xdr, 4 + 4 + 4 + 4 + 4);
362 *p++ = cpu_to_be32(session->se_cb_seq_nr); /* csa_sequenceid */
363 *p++ = xdr_zero; /* csa_slotid */
364 *p++ = xdr_zero; /* csa_highest_slotid */
365 *p++ = xdr_zero; /* csa_cachethis */
366 xdr_encode_empty_array(p); /* csa_referring_call_lists */
367
368 hdr->nops++;
369}
370
371/*
372 * CB_SEQUENCE4resok
373 *
374 * struct CB_SEQUENCE4resok {
375 * sessionid4 csr_sessionid;
376 * sequenceid4 csr_sequenceid;
377 * slotid4 csr_slotid;
378 * slotid4 csr_highest_slotid;
379 * slotid4 csr_target_highest_slotid;
380 * };
381 *
382 * union CB_SEQUENCE4res switch (nfsstat4 csr_status) {
383 * case NFS4_OK:
384 * CB_SEQUENCE4resok csr_resok4;
385 * default:
386 * void;
387 * };
388 *
389 * Our current back channel implmentation supports a single backchannel
390 * with a single slot.
391 */
392static int decode_cb_sequence4resok(struct xdr_stream *xdr,
393 struct nfsd4_callback *cb)
394{
395 struct nfsd4_session *session = cb->cb_clp->cl_cb_session;
396 int status = -ESERVERFAULT;
397 __be32 *p;
398 u32 dummy;
399
400 /*
401 * If the server returns different values for sessionID, slotID or
402 * sequence number, the server is looney tunes.
403 */
404 p = xdr_inline_decode(xdr, NFS4_MAX_SESSIONID_LEN + 4 + 4 + 4 + 4);
405 if (unlikely(p == NULL))
406 goto out_overflow;
407
408 if (memcmp(p, session->se_sessionid.data, NFS4_MAX_SESSIONID_LEN)) {
409 dprintk("NFS: %s Invalid session id\n", __func__);
410 goto out;
411 }
412 p += XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN);
413
414 dummy = be32_to_cpup(p++);
415 if (dummy != session->se_cb_seq_nr) {
416 dprintk("NFS: %s Invalid sequence number\n", __func__);
417 goto out;
418 }
419
420 dummy = be32_to_cpup(p++);
421 if (dummy != 0) {
422 dprintk("NFS: %s Invalid slotid\n", __func__);
423 goto out;
424 }
425
426 /*
427 * FIXME: process highest slotid and target highest slotid
428 */
429 status = 0;
430out:
431 cb->cb_seq_status = status;
432 return status;
433out_overflow:
434 status = -EIO;
435 goto out;
436}
437
438static int decode_cb_sequence4res(struct xdr_stream *xdr,
439 struct nfsd4_callback *cb)
440{
441 int status;
442
443 if (cb->cb_clp->cl_minorversion == 0)
444 return 0;
445
446 status = decode_cb_op_status(xdr, OP_CB_SEQUENCE, &cb->cb_seq_status);
447 if (unlikely(status || cb->cb_seq_status))
448 return status;
449
450 return decode_cb_sequence4resok(xdr, cb);
451}
452
453/*
454 * NFSv4.0 and NFSv4.1 XDR encode functions
455 *
456 * NFSv4.0 callback argument types are defined in section 15 of RFC
457 * 3530: "Network File System (NFS) version 4 Protocol" and section 20
458 * of RFC 5661: "Network File System (NFS) Version 4 Minor Version 1
459 * Protocol".
460 */
461
462/*
463 * NB: Without this zero space reservation, callbacks over krb5p fail
464 */
465static void nfs4_xdr_enc_cb_null(struct rpc_rqst *req, struct xdr_stream *xdr,
466 const void *__unused)
467{
468 xdr_reserve_space(xdr, 0);
469}
470
471/*
472 * 20.2. Operation 4: CB_RECALL - Recall a Delegation
473 */
474static void nfs4_xdr_enc_cb_recall(struct rpc_rqst *req, struct xdr_stream *xdr,
475 const void *data)
476{
477 const struct nfsd4_callback *cb = data;
478 const struct nfs4_delegation *dp = cb_to_delegation(cb);
479 struct nfs4_cb_compound_hdr hdr = {
480 .ident = cb->cb_clp->cl_cb_ident,
481 .minorversion = cb->cb_clp->cl_minorversion,
482 };
483
484 encode_cb_compound4args(xdr, &hdr);
485 encode_cb_sequence4args(xdr, cb, &hdr);
486 encode_cb_recall4args(xdr, dp, &hdr);
487 encode_cb_nops(&hdr);
488}
489
490/*
491 * 20.6. Operation 8: CB_RECALL_ANY - Keep Any N Recallable Objects
492 */
493static void
494nfs4_xdr_enc_cb_recall_any(struct rpc_rqst *req,
495 struct xdr_stream *xdr, const void *data)
496{
497 const struct nfsd4_callback *cb = data;
498 struct nfsd4_cb_recall_any *ra;
499 struct nfs4_cb_compound_hdr hdr = {
500 .ident = cb->cb_clp->cl_cb_ident,
501 .minorversion = cb->cb_clp->cl_minorversion,
502 };
503
504 ra = container_of(cb, struct nfsd4_cb_recall_any, ra_cb);
505 encode_cb_compound4args(xdr, &hdr);
506 encode_cb_sequence4args(xdr, cb, &hdr);
507 encode_cb_recallany4args(xdr, &hdr, ra);
508 encode_cb_nops(&hdr);
509}
510
511/*
512 * NFSv4.0 and NFSv4.1 XDR decode functions
513 *
514 * NFSv4.0 callback result types are defined in section 15 of RFC
515 * 3530: "Network File System (NFS) version 4 Protocol" and section 20
516 * of RFC 5661: "Network File System (NFS) Version 4 Minor Version 1
517 * Protocol".
518 */
519
520static int nfs4_xdr_dec_cb_null(struct rpc_rqst *req, struct xdr_stream *xdr,
521 void *__unused)
522{
523 return 0;
524}
525
526/*
527 * 20.2. Operation 4: CB_RECALL - Recall a Delegation
528 */
529static int nfs4_xdr_dec_cb_recall(struct rpc_rqst *rqstp,
530 struct xdr_stream *xdr,
531 void *data)
532{
533 struct nfsd4_callback *cb = data;
534 struct nfs4_cb_compound_hdr hdr;
535 int status;
536
537 status = decode_cb_compound4res(xdr, &hdr);
538 if (unlikely(status))
539 return status;
540
541 status = decode_cb_sequence4res(xdr, cb);
542 if (unlikely(status || cb->cb_seq_status))
543 return status;
544
545 return decode_cb_op_status(xdr, OP_CB_RECALL, &cb->cb_status);
546}
547
548/*
549 * 20.6. Operation 8: CB_RECALL_ANY - Keep Any N Recallable Objects
550 */
551static int
552nfs4_xdr_dec_cb_recall_any(struct rpc_rqst *rqstp,
553 struct xdr_stream *xdr,
554 void *data)
555{
556 struct nfsd4_callback *cb = data;
557 struct nfs4_cb_compound_hdr hdr;
558 int status;
559
560 status = decode_cb_compound4res(xdr, &hdr);
561 if (unlikely(status))
562 return status;
563 status = decode_cb_sequence4res(xdr, cb);
564 if (unlikely(status || cb->cb_seq_status))
565 return status;
566 status = decode_cb_op_status(xdr, OP_CB_RECALL_ANY, &cb->cb_status);
567 return status;
568}
569
570#ifdef CONFIG_NFSD_PNFS
571/*
572 * CB_LAYOUTRECALL4args
573 *
574 * struct layoutrecall_file4 {
575 * nfs_fh4 lor_fh;
576 * offset4 lor_offset;
577 * length4 lor_length;
578 * stateid4 lor_stateid;
579 * };
580 *
581 * union layoutrecall4 switch(layoutrecall_type4 lor_recalltype) {
582 * case LAYOUTRECALL4_FILE:
583 * layoutrecall_file4 lor_layout;
584 * case LAYOUTRECALL4_FSID:
585 * fsid4 lor_fsid;
586 * case LAYOUTRECALL4_ALL:
587 * void;
588 * };
589 *
590 * struct CB_LAYOUTRECALL4args {
591 * layouttype4 clora_type;
592 * layoutiomode4 clora_iomode;
593 * bool clora_changed;
594 * layoutrecall4 clora_recall;
595 * };
596 */
597static void encode_cb_layout4args(struct xdr_stream *xdr,
598 const struct nfs4_layout_stateid *ls,
599 struct nfs4_cb_compound_hdr *hdr)
600{
601 __be32 *p;
602
603 BUG_ON(hdr->minorversion == 0);
604
605 p = xdr_reserve_space(xdr, 5 * 4);
606 *p++ = cpu_to_be32(OP_CB_LAYOUTRECALL);
607 *p++ = cpu_to_be32(ls->ls_layout_type);
608 *p++ = cpu_to_be32(IOMODE_ANY);
609 *p++ = cpu_to_be32(1);
610 *p = cpu_to_be32(RETURN_FILE);
611
612 encode_nfs_fh4(xdr, &ls->ls_stid.sc_file->fi_fhandle);
613
614 p = xdr_reserve_space(xdr, 2 * 8);
615 p = xdr_encode_hyper(p, 0);
616 xdr_encode_hyper(p, NFS4_MAX_UINT64);
617
618 encode_stateid4(xdr, &ls->ls_recall_sid);
619
620 hdr->nops++;
621}
622
623static void nfs4_xdr_enc_cb_layout(struct rpc_rqst *req,
624 struct xdr_stream *xdr,
625 const void *data)
626{
627 const struct nfsd4_callback *cb = data;
628 const struct nfs4_layout_stateid *ls =
629 container_of(cb, struct nfs4_layout_stateid, ls_recall);
630 struct nfs4_cb_compound_hdr hdr = {
631 .ident = 0,
632 .minorversion = cb->cb_clp->cl_minorversion,
633 };
634
635 encode_cb_compound4args(xdr, &hdr);
636 encode_cb_sequence4args(xdr, cb, &hdr);
637 encode_cb_layout4args(xdr, ls, &hdr);
638 encode_cb_nops(&hdr);
639}
640
641static int nfs4_xdr_dec_cb_layout(struct rpc_rqst *rqstp,
642 struct xdr_stream *xdr,
643 void *data)
644{
645 struct nfsd4_callback *cb = data;
646 struct nfs4_cb_compound_hdr hdr;
647 int status;
648
649 status = decode_cb_compound4res(xdr, &hdr);
650 if (unlikely(status))
651 return status;
652
653 status = decode_cb_sequence4res(xdr, cb);
654 if (unlikely(status || cb->cb_seq_status))
655 return status;
656
657 return decode_cb_op_status(xdr, OP_CB_LAYOUTRECALL, &cb->cb_status);
658}
659#endif /* CONFIG_NFSD_PNFS */
660
661static void encode_stateowner(struct xdr_stream *xdr, struct nfs4_stateowner *so)
662{
663 __be32 *p;
664
665 p = xdr_reserve_space(xdr, 8 + 4 + so->so_owner.len);
666 p = xdr_encode_opaque_fixed(p, &so->so_client->cl_clientid, 8);
667 xdr_encode_opaque(p, so->so_owner.data, so->so_owner.len);
668}
669
670static void nfs4_xdr_enc_cb_notify_lock(struct rpc_rqst *req,
671 struct xdr_stream *xdr,
672 const void *data)
673{
674 const struct nfsd4_callback *cb = data;
675 const struct nfsd4_blocked_lock *nbl =
676 container_of(cb, struct nfsd4_blocked_lock, nbl_cb);
677 struct nfs4_lockowner *lo = (struct nfs4_lockowner *)nbl->nbl_lock.fl_owner;
678 struct nfs4_cb_compound_hdr hdr = {
679 .ident = 0,
680 .minorversion = cb->cb_clp->cl_minorversion,
681 };
682
683 __be32 *p;
684
685 BUG_ON(hdr.minorversion == 0);
686
687 encode_cb_compound4args(xdr, &hdr);
688 encode_cb_sequence4args(xdr, cb, &hdr);
689
690 p = xdr_reserve_space(xdr, 4);
691 *p = cpu_to_be32(OP_CB_NOTIFY_LOCK);
692 encode_nfs_fh4(xdr, &nbl->nbl_fh);
693 encode_stateowner(xdr, &lo->lo_owner);
694 hdr.nops++;
695
696 encode_cb_nops(&hdr);
697}
698
699static int nfs4_xdr_dec_cb_notify_lock(struct rpc_rqst *rqstp,
700 struct xdr_stream *xdr,
701 void *data)
702{
703 struct nfsd4_callback *cb = data;
704 struct nfs4_cb_compound_hdr hdr;
705 int status;
706
707 status = decode_cb_compound4res(xdr, &hdr);
708 if (unlikely(status))
709 return status;
710
711 status = decode_cb_sequence4res(xdr, cb);
712 if (unlikely(status || cb->cb_seq_status))
713 return status;
714
715 return decode_cb_op_status(xdr, OP_CB_NOTIFY_LOCK, &cb->cb_status);
716}
717
718/*
719 * struct write_response4 {
720 * stateid4 wr_callback_id<1>;
721 * length4 wr_count;
722 * stable_how4 wr_committed;
723 * verifier4 wr_writeverf;
724 * };
725 * union offload_info4 switch (nfsstat4 coa_status) {
726 * case NFS4_OK:
727 * write_response4 coa_resok4;
728 * default:
729 * length4 coa_bytes_copied;
730 * };
731 * struct CB_OFFLOAD4args {
732 * nfs_fh4 coa_fh;
733 * stateid4 coa_stateid;
734 * offload_info4 coa_offload_info;
735 * };
736 */
737static void encode_offload_info4(struct xdr_stream *xdr,
738 const struct nfsd4_cb_offload *cbo)
739{
740 __be32 *p;
741
742 p = xdr_reserve_space(xdr, 4);
743 *p = cbo->co_nfserr;
744 switch (cbo->co_nfserr) {
745 case nfs_ok:
746 p = xdr_reserve_space(xdr, 4 + 8 + 4 + NFS4_VERIFIER_SIZE);
747 p = xdr_encode_empty_array(p);
748 p = xdr_encode_hyper(p, cbo->co_res.wr_bytes_written);
749 *p++ = cpu_to_be32(cbo->co_res.wr_stable_how);
750 p = xdr_encode_opaque_fixed(p, cbo->co_res.wr_verifier.data,
751 NFS4_VERIFIER_SIZE);
752 break;
753 default:
754 p = xdr_reserve_space(xdr, 8);
755 /* We always return success if bytes were written */
756 p = xdr_encode_hyper(p, 0);
757 }
758}
759
760static void encode_cb_offload4args(struct xdr_stream *xdr,
761 const struct nfsd4_cb_offload *cbo,
762 struct nfs4_cb_compound_hdr *hdr)
763{
764 __be32 *p;
765
766 p = xdr_reserve_space(xdr, 4);
767 *p = cpu_to_be32(OP_CB_OFFLOAD);
768 encode_nfs_fh4(xdr, &cbo->co_fh);
769 encode_stateid4(xdr, &cbo->co_res.cb_stateid);
770 encode_offload_info4(xdr, cbo);
771
772 hdr->nops++;
773}
774
775static void nfs4_xdr_enc_cb_offload(struct rpc_rqst *req,
776 struct xdr_stream *xdr,
777 const void *data)
778{
779 const struct nfsd4_callback *cb = data;
780 const struct nfsd4_cb_offload *cbo =
781 container_of(cb, struct nfsd4_cb_offload, co_cb);
782 struct nfs4_cb_compound_hdr hdr = {
783 .ident = 0,
784 .minorversion = cb->cb_clp->cl_minorversion,
785 };
786
787 encode_cb_compound4args(xdr, &hdr);
788 encode_cb_sequence4args(xdr, cb, &hdr);
789 encode_cb_offload4args(xdr, cbo, &hdr);
790 encode_cb_nops(&hdr);
791}
792
793static int nfs4_xdr_dec_cb_offload(struct rpc_rqst *rqstp,
794 struct xdr_stream *xdr,
795 void *data)
796{
797 struct nfsd4_callback *cb = data;
798 struct nfs4_cb_compound_hdr hdr;
799 int status;
800
801 status = decode_cb_compound4res(xdr, &hdr);
802 if (unlikely(status))
803 return status;
804
805 status = decode_cb_sequence4res(xdr, cb);
806 if (unlikely(status || cb->cb_seq_status))
807 return status;
808
809 return decode_cb_op_status(xdr, OP_CB_OFFLOAD, &cb->cb_status);
810}
811/*
812 * RPC procedure tables
813 */
814#define PROC(proc, call, argtype, restype) \
815[NFSPROC4_CLNT_##proc] = { \
816 .p_proc = NFSPROC4_CB_##call, \
817 .p_encode = nfs4_xdr_enc_##argtype, \
818 .p_decode = nfs4_xdr_dec_##restype, \
819 .p_arglen = NFS4_enc_##argtype##_sz, \
820 .p_replen = NFS4_dec_##restype##_sz, \
821 .p_statidx = NFSPROC4_CB_##call, \
822 .p_name = #proc, \
823}
824
825static const struct rpc_procinfo nfs4_cb_procedures[] = {
826 PROC(CB_NULL, NULL, cb_null, cb_null),
827 PROC(CB_RECALL, COMPOUND, cb_recall, cb_recall),
828#ifdef CONFIG_NFSD_PNFS
829 PROC(CB_LAYOUT, COMPOUND, cb_layout, cb_layout),
830#endif
831 PROC(CB_NOTIFY_LOCK, COMPOUND, cb_notify_lock, cb_notify_lock),
832 PROC(CB_OFFLOAD, COMPOUND, cb_offload, cb_offload),
833 PROC(CB_RECALL_ANY, COMPOUND, cb_recall_any, cb_recall_any),
834};
835
836static unsigned int nfs4_cb_counts[ARRAY_SIZE(nfs4_cb_procedures)];
837static const struct rpc_version nfs_cb_version4 = {
838/*
839 * Note on the callback rpc program version number: despite language in rfc
840 * 5661 section 18.36.3 requiring servers to use 4 in this field, the
841 * official xdr descriptions for both 4.0 and 4.1 specify version 1, and
842 * in practice that appears to be what implementations use. The section
843 * 18.36.3 language is expected to be fixed in an erratum.
844 */
845 .number = 1,
846 .nrprocs = ARRAY_SIZE(nfs4_cb_procedures),
847 .procs = nfs4_cb_procedures,
848 .counts = nfs4_cb_counts,
849};
850
851static const struct rpc_version *nfs_cb_version[2] = {
852 [1] = &nfs_cb_version4,
853};
854
855static const struct rpc_program cb_program;
856
857static struct rpc_stat cb_stats = {
858 .program = &cb_program
859};
860
861#define NFS4_CALLBACK 0x40000000
862static const struct rpc_program cb_program = {
863 .name = "nfs4_cb",
864 .number = NFS4_CALLBACK,
865 .nrvers = ARRAY_SIZE(nfs_cb_version),
866 .version = nfs_cb_version,
867 .stats = &cb_stats,
868 .pipe_dir_name = "nfsd4_cb",
869};
870
871static int max_cb_time(struct net *net)
872{
873 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
874
875 /*
876 * nfsd4_lease is set to at most one hour in __nfsd4_write_time,
877 * so we can use 32-bit math on it. Warn if that assumption
878 * ever stops being true.
879 */
880 if (WARN_ON_ONCE(nn->nfsd4_lease > 3600))
881 return 360 * HZ;
882
883 return max(((u32)nn->nfsd4_lease)/10, 1u) * HZ;
884}
885
886static struct workqueue_struct *callback_wq;
887
888static bool nfsd4_queue_cb(struct nfsd4_callback *cb)
889{
890 return queue_work(callback_wq, &cb->cb_work);
891}
892
893static void nfsd41_cb_inflight_begin(struct nfs4_client *clp)
894{
895 atomic_inc(&clp->cl_cb_inflight);
896}
897
898static void nfsd41_cb_inflight_end(struct nfs4_client *clp)
899{
900
901 if (atomic_dec_and_test(&clp->cl_cb_inflight))
902 wake_up_var(&clp->cl_cb_inflight);
903}
904
905static void nfsd41_cb_inflight_wait_complete(struct nfs4_client *clp)
906{
907 wait_var_event(&clp->cl_cb_inflight,
908 !atomic_read(&clp->cl_cb_inflight));
909}
910
911static const struct cred *get_backchannel_cred(struct nfs4_client *clp, struct rpc_clnt *client, struct nfsd4_session *ses)
912{
913 if (clp->cl_minorversion == 0) {
914 client->cl_principal = clp->cl_cred.cr_targ_princ ?
915 clp->cl_cred.cr_targ_princ : "nfs";
916
917 return get_cred(rpc_machine_cred());
918 } else {
919 struct cred *kcred;
920
921 kcred = prepare_kernel_cred(&init_task);
922 if (!kcred)
923 return NULL;
924
925 kcred->fsuid = ses->se_cb_sec.uid;
926 kcred->fsgid = ses->se_cb_sec.gid;
927 return kcred;
928 }
929}
930
931static int setup_callback_client(struct nfs4_client *clp, struct nfs4_cb_conn *conn, struct nfsd4_session *ses)
932{
933 int maxtime = max_cb_time(clp->net);
934 struct rpc_timeout timeparms = {
935 .to_initval = maxtime,
936 .to_retries = 0,
937 .to_maxval = maxtime,
938 };
939 struct rpc_create_args args = {
940 .net = clp->net,
941 .address = (struct sockaddr *) &conn->cb_addr,
942 .addrsize = conn->cb_addrlen,
943 .saddress = (struct sockaddr *) &conn->cb_saddr,
944 .timeout = &timeparms,
945 .program = &cb_program,
946 .version = 1,
947 .flags = (RPC_CLNT_CREATE_NOPING | RPC_CLNT_CREATE_QUIET),
948 .cred = current_cred(),
949 };
950 struct rpc_clnt *client;
951 const struct cred *cred;
952
953 if (clp->cl_minorversion == 0) {
954 if (!clp->cl_cred.cr_principal &&
955 (clp->cl_cred.cr_flavor >= RPC_AUTH_GSS_KRB5)) {
956 trace_nfsd_cb_setup_err(clp, -EINVAL);
957 return -EINVAL;
958 }
959 args.client_name = clp->cl_cred.cr_principal;
960 args.prognumber = conn->cb_prog;
961 args.protocol = XPRT_TRANSPORT_TCP;
962 args.authflavor = clp->cl_cred.cr_flavor;
963 clp->cl_cb_ident = conn->cb_ident;
964 } else {
965 if (!conn->cb_xprt)
966 return -EINVAL;
967 clp->cl_cb_session = ses;
968 args.bc_xprt = conn->cb_xprt;
969 args.prognumber = clp->cl_cb_session->se_cb_prog;
970 args.protocol = conn->cb_xprt->xpt_class->xcl_ident |
971 XPRT_TRANSPORT_BC;
972 args.authflavor = ses->se_cb_sec.flavor;
973 }
974 /* Create RPC client */
975 client = rpc_create(&args);
976 if (IS_ERR(client)) {
977 trace_nfsd_cb_setup_err(clp, PTR_ERR(client));
978 return PTR_ERR(client);
979 }
980 cred = get_backchannel_cred(clp, client, ses);
981 if (!cred) {
982 trace_nfsd_cb_setup_err(clp, -ENOMEM);
983 rpc_shutdown_client(client);
984 return -ENOMEM;
985 }
986
987 if (clp->cl_minorversion != 0)
988 clp->cl_cb_conn.cb_xprt = conn->cb_xprt;
989 clp->cl_cb_client = client;
990 clp->cl_cb_cred = cred;
991 rcu_read_lock();
992 trace_nfsd_cb_setup(clp, rpc_peeraddr2str(client, RPC_DISPLAY_NETID),
993 args.authflavor);
994 rcu_read_unlock();
995 return 0;
996}
997
998static void nfsd4_mark_cb_state(struct nfs4_client *clp, int newstate)
999{
1000 if (clp->cl_cb_state != newstate) {
1001 clp->cl_cb_state = newstate;
1002 trace_nfsd_cb_state(clp);
1003 }
1004}
1005
1006static void nfsd4_mark_cb_down(struct nfs4_client *clp, int reason)
1007{
1008 if (test_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags))
1009 return;
1010 nfsd4_mark_cb_state(clp, NFSD4_CB_DOWN);
1011}
1012
1013static void nfsd4_mark_cb_fault(struct nfs4_client *clp, int reason)
1014{
1015 if (test_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags))
1016 return;
1017 nfsd4_mark_cb_state(clp, NFSD4_CB_FAULT);
1018}
1019
1020static void nfsd4_cb_probe_done(struct rpc_task *task, void *calldata)
1021{
1022 struct nfs4_client *clp = container_of(calldata, struct nfs4_client, cl_cb_null);
1023
1024 if (task->tk_status)
1025 nfsd4_mark_cb_down(clp, task->tk_status);
1026 else
1027 nfsd4_mark_cb_state(clp, NFSD4_CB_UP);
1028}
1029
1030static void nfsd4_cb_probe_release(void *calldata)
1031{
1032 struct nfs4_client *clp = container_of(calldata, struct nfs4_client, cl_cb_null);
1033
1034 nfsd41_cb_inflight_end(clp);
1035
1036}
1037
1038static const struct rpc_call_ops nfsd4_cb_probe_ops = {
1039 /* XXX: release method to ensure we set the cb channel down if
1040 * necessary on early failure? */
1041 .rpc_call_done = nfsd4_cb_probe_done,
1042 .rpc_release = nfsd4_cb_probe_release,
1043};
1044
1045/*
1046 * Poke the callback thread to process any updates to the callback
1047 * parameters, and send a null probe.
1048 */
1049void nfsd4_probe_callback(struct nfs4_client *clp)
1050{
1051 trace_nfsd_cb_probe(clp);
1052 nfsd4_mark_cb_state(clp, NFSD4_CB_UNKNOWN);
1053 set_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags);
1054 nfsd4_run_cb(&clp->cl_cb_null);
1055}
1056
1057void nfsd4_probe_callback_sync(struct nfs4_client *clp)
1058{
1059 nfsd4_probe_callback(clp);
1060 flush_workqueue(callback_wq);
1061}
1062
1063void nfsd4_change_callback(struct nfs4_client *clp, struct nfs4_cb_conn *conn)
1064{
1065 nfsd4_mark_cb_state(clp, NFSD4_CB_UNKNOWN);
1066 spin_lock(&clp->cl_lock);
1067 memcpy(&clp->cl_cb_conn, conn, sizeof(struct nfs4_cb_conn));
1068 spin_unlock(&clp->cl_lock);
1069}
1070
1071/*
1072 * There's currently a single callback channel slot.
1073 * If the slot is available, then mark it busy. Otherwise, set the
1074 * thread for sleeping on the callback RPC wait queue.
1075 */
1076static bool nfsd41_cb_get_slot(struct nfsd4_callback *cb, struct rpc_task *task)
1077{
1078 struct nfs4_client *clp = cb->cb_clp;
1079
1080 if (!cb->cb_holds_slot &&
1081 test_and_set_bit(0, &clp->cl_cb_slot_busy) != 0) {
1082 rpc_sleep_on(&clp->cl_cb_waitq, task, NULL);
1083 /* Race breaker */
1084 if (test_and_set_bit(0, &clp->cl_cb_slot_busy) != 0) {
1085 dprintk("%s slot is busy\n", __func__);
1086 return false;
1087 }
1088 rpc_wake_up_queued_task(&clp->cl_cb_waitq, task);
1089 }
1090 cb->cb_holds_slot = true;
1091 return true;
1092}
1093
1094static void nfsd41_cb_release_slot(struct nfsd4_callback *cb)
1095{
1096 struct nfs4_client *clp = cb->cb_clp;
1097
1098 if (cb->cb_holds_slot) {
1099 cb->cb_holds_slot = false;
1100 clear_bit(0, &clp->cl_cb_slot_busy);
1101 rpc_wake_up_next(&clp->cl_cb_waitq);
1102 }
1103}
1104
1105static void nfsd41_destroy_cb(struct nfsd4_callback *cb)
1106{
1107 struct nfs4_client *clp = cb->cb_clp;
1108
1109 nfsd41_cb_release_slot(cb);
1110 if (cb->cb_ops && cb->cb_ops->release)
1111 cb->cb_ops->release(cb);
1112 nfsd41_cb_inflight_end(clp);
1113}
1114
1115/*
1116 * TODO: cb_sequence should support referring call lists, cachethis, multiple
1117 * slots, and mark callback channel down on communication errors.
1118 */
1119static void nfsd4_cb_prepare(struct rpc_task *task, void *calldata)
1120{
1121 struct nfsd4_callback *cb = calldata;
1122 struct nfs4_client *clp = cb->cb_clp;
1123 u32 minorversion = clp->cl_minorversion;
1124
1125 /*
1126 * cb_seq_status is only set in decode_cb_sequence4res,
1127 * and so will remain 1 if an rpc level failure occurs.
1128 */
1129 cb->cb_seq_status = 1;
1130 cb->cb_status = 0;
1131 if (minorversion && !nfsd41_cb_get_slot(cb, task))
1132 return;
1133 rpc_call_start(task);
1134}
1135
1136static bool nfsd4_cb_sequence_done(struct rpc_task *task, struct nfsd4_callback *cb)
1137{
1138 struct nfs4_client *clp = cb->cb_clp;
1139 struct nfsd4_session *session = clp->cl_cb_session;
1140 bool ret = true;
1141
1142 if (!clp->cl_minorversion) {
1143 /*
1144 * If the backchannel connection was shut down while this
1145 * task was queued, we need to resubmit it after setting up
1146 * a new backchannel connection.
1147 *
1148 * Note that if we lost our callback connection permanently
1149 * the submission code will error out, so we don't need to
1150 * handle that case here.
1151 */
1152 if (RPC_SIGNALLED(task))
1153 goto need_restart;
1154
1155 return true;
1156 }
1157
1158 if (!cb->cb_holds_slot)
1159 goto need_restart;
1160
1161 switch (cb->cb_seq_status) {
1162 case 0:
1163 /*
1164 * No need for lock, access serialized in nfsd4_cb_prepare
1165 *
1166 * RFC5661 20.9.3
1167 * If CB_SEQUENCE returns an error, then the state of the slot
1168 * (sequence ID, cached reply) MUST NOT change.
1169 */
1170 ++session->se_cb_seq_nr;
1171 break;
1172 case -ESERVERFAULT:
1173 ++session->se_cb_seq_nr;
1174 fallthrough;
1175 case 1:
1176 case -NFS4ERR_BADSESSION:
1177 nfsd4_mark_cb_fault(cb->cb_clp, cb->cb_seq_status);
1178 ret = false;
1179 break;
1180 case -NFS4ERR_DELAY:
1181 if (!rpc_restart_call(task))
1182 goto out;
1183
1184 rpc_delay(task, 2 * HZ);
1185 return false;
1186 case -NFS4ERR_BADSLOT:
1187 goto retry_nowait;
1188 case -NFS4ERR_SEQ_MISORDERED:
1189 if (session->se_cb_seq_nr != 1) {
1190 session->se_cb_seq_nr = 1;
1191 goto retry_nowait;
1192 }
1193 break;
1194 default:
1195 nfsd4_mark_cb_fault(cb->cb_clp, cb->cb_seq_status);
1196 dprintk("%s: unprocessed error %d\n", __func__,
1197 cb->cb_seq_status);
1198 }
1199
1200 nfsd41_cb_release_slot(cb);
1201 dprintk("%s: freed slot, new seqid=%d\n", __func__,
1202 clp->cl_cb_session->se_cb_seq_nr);
1203
1204 if (RPC_SIGNALLED(task))
1205 goto need_restart;
1206out:
1207 return ret;
1208retry_nowait:
1209 if (rpc_restart_call_prepare(task))
1210 ret = false;
1211 goto out;
1212need_restart:
1213 if (!test_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags)) {
1214 task->tk_status = 0;
1215 cb->cb_need_restart = true;
1216 }
1217 return false;
1218}
1219
1220static void nfsd4_cb_done(struct rpc_task *task, void *calldata)
1221{
1222 struct nfsd4_callback *cb = calldata;
1223 struct nfs4_client *clp = cb->cb_clp;
1224
1225 if (!nfsd4_cb_sequence_done(task, cb))
1226 return;
1227
1228 if (cb->cb_status) {
1229 WARN_ON_ONCE(task->tk_status);
1230 task->tk_status = cb->cb_status;
1231 }
1232
1233 switch (cb->cb_ops->done(cb, task)) {
1234 case 0:
1235 task->tk_status = 0;
1236 rpc_restart_call_prepare(task);
1237 return;
1238 case 1:
1239 switch (task->tk_status) {
1240 case -EIO:
1241 case -ETIMEDOUT:
1242 case -EACCES:
1243 nfsd4_mark_cb_down(clp, task->tk_status);
1244 }
1245 break;
1246 default:
1247 BUG();
1248 }
1249}
1250
1251static void nfsd4_cb_release(void *calldata)
1252{
1253 struct nfsd4_callback *cb = calldata;
1254
1255 if (cb->cb_need_restart)
1256 nfsd4_queue_cb(cb);
1257 else
1258 nfsd41_destroy_cb(cb);
1259
1260}
1261
1262static const struct rpc_call_ops nfsd4_cb_ops = {
1263 .rpc_call_prepare = nfsd4_cb_prepare,
1264 .rpc_call_done = nfsd4_cb_done,
1265 .rpc_release = nfsd4_cb_release,
1266};
1267
1268int nfsd4_create_callback_queue(void)
1269{
1270 callback_wq = alloc_ordered_workqueue("nfsd4_callbacks", 0);
1271 if (!callback_wq)
1272 return -ENOMEM;
1273 return 0;
1274}
1275
1276void nfsd4_destroy_callback_queue(void)
1277{
1278 destroy_workqueue(callback_wq);
1279}
1280
1281/* must be called under the state lock */
1282void nfsd4_shutdown_callback(struct nfs4_client *clp)
1283{
1284 if (clp->cl_cb_state != NFSD4_CB_UNKNOWN)
1285 trace_nfsd_cb_shutdown(clp);
1286
1287 set_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags);
1288 /*
1289 * Note this won't actually result in a null callback;
1290 * instead, nfsd4_run_cb_null() will detect the killed
1291 * client, destroy the rpc client, and stop:
1292 */
1293 nfsd4_run_cb(&clp->cl_cb_null);
1294 flush_workqueue(callback_wq);
1295 nfsd41_cb_inflight_wait_complete(clp);
1296}
1297
1298/* requires cl_lock: */
1299static struct nfsd4_conn * __nfsd4_find_backchannel(struct nfs4_client *clp)
1300{
1301 struct nfsd4_session *s;
1302 struct nfsd4_conn *c;
1303
1304 list_for_each_entry(s, &clp->cl_sessions, se_perclnt) {
1305 list_for_each_entry(c, &s->se_conns, cn_persession) {
1306 if (c->cn_flags & NFS4_CDFC4_BACK)
1307 return c;
1308 }
1309 }
1310 return NULL;
1311}
1312
1313/*
1314 * Note there isn't a lot of locking in this code; instead we depend on
1315 * the fact that it is run from the callback_wq, which won't run two
1316 * work items at once. So, for example, callback_wq handles all access
1317 * of cl_cb_client and all calls to rpc_create or rpc_shutdown_client.
1318 */
1319static void nfsd4_process_cb_update(struct nfsd4_callback *cb)
1320{
1321 struct nfs4_cb_conn conn;
1322 struct nfs4_client *clp = cb->cb_clp;
1323 struct nfsd4_session *ses = NULL;
1324 struct nfsd4_conn *c;
1325 int err;
1326
1327 /*
1328 * This is either an update, or the client dying; in either case,
1329 * kill the old client:
1330 */
1331 if (clp->cl_cb_client) {
1332 rpc_shutdown_client(clp->cl_cb_client);
1333 clp->cl_cb_client = NULL;
1334 put_cred(clp->cl_cb_cred);
1335 clp->cl_cb_cred = NULL;
1336 }
1337 if (clp->cl_cb_conn.cb_xprt) {
1338 svc_xprt_put(clp->cl_cb_conn.cb_xprt);
1339 clp->cl_cb_conn.cb_xprt = NULL;
1340 }
1341 if (test_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags))
1342 return;
1343 spin_lock(&clp->cl_lock);
1344 /*
1345 * Only serialized callback code is allowed to clear these
1346 * flags; main nfsd code can only set them:
1347 */
1348 BUG_ON(!(clp->cl_flags & NFSD4_CLIENT_CB_FLAG_MASK));
1349 clear_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags);
1350 memcpy(&conn, &cb->cb_clp->cl_cb_conn, sizeof(struct nfs4_cb_conn));
1351 c = __nfsd4_find_backchannel(clp);
1352 if (c) {
1353 svc_xprt_get(c->cn_xprt);
1354 conn.cb_xprt = c->cn_xprt;
1355 ses = c->cn_session;
1356 }
1357 spin_unlock(&clp->cl_lock);
1358
1359 err = setup_callback_client(clp, &conn, ses);
1360 if (err) {
1361 nfsd4_mark_cb_down(clp, err);
1362 if (c)
1363 svc_xprt_put(c->cn_xprt);
1364 return;
1365 }
1366}
1367
1368static void
1369nfsd4_run_cb_work(struct work_struct *work)
1370{
1371 struct nfsd4_callback *cb =
1372 container_of(work, struct nfsd4_callback, cb_work);
1373 struct nfs4_client *clp = cb->cb_clp;
1374 struct rpc_clnt *clnt;
1375 int flags;
1376
1377 if (cb->cb_need_restart) {
1378 cb->cb_need_restart = false;
1379 } else {
1380 if (cb->cb_ops && cb->cb_ops->prepare)
1381 cb->cb_ops->prepare(cb);
1382 }
1383
1384 if (clp->cl_flags & NFSD4_CLIENT_CB_FLAG_MASK)
1385 nfsd4_process_cb_update(cb);
1386
1387 clnt = clp->cl_cb_client;
1388 if (!clnt) {
1389 /* Callback channel broken, or client killed; give up: */
1390 nfsd41_destroy_cb(cb);
1391 return;
1392 }
1393
1394 /*
1395 * Don't send probe messages for 4.1 or later.
1396 */
1397 if (!cb->cb_ops && clp->cl_minorversion) {
1398 nfsd4_mark_cb_state(clp, NFSD4_CB_UP);
1399 nfsd41_destroy_cb(cb);
1400 return;
1401 }
1402
1403 cb->cb_msg.rpc_cred = clp->cl_cb_cred;
1404 flags = clp->cl_minorversion ? RPC_TASK_NOCONNECT : RPC_TASK_SOFTCONN;
1405 rpc_call_async(clnt, &cb->cb_msg, RPC_TASK_SOFT | flags,
1406 cb->cb_ops ? &nfsd4_cb_ops : &nfsd4_cb_probe_ops, cb);
1407}
1408
1409void nfsd4_init_cb(struct nfsd4_callback *cb, struct nfs4_client *clp,
1410 const struct nfsd4_callback_ops *ops, enum nfsd4_cb_op op)
1411{
1412 cb->cb_clp = clp;
1413 cb->cb_msg.rpc_proc = &nfs4_cb_procedures[op];
1414 cb->cb_msg.rpc_argp = cb;
1415 cb->cb_msg.rpc_resp = cb;
1416 cb->cb_ops = ops;
1417 INIT_WORK(&cb->cb_work, nfsd4_run_cb_work);
1418 cb->cb_seq_status = 1;
1419 cb->cb_status = 0;
1420 cb->cb_need_restart = false;
1421 cb->cb_holds_slot = false;
1422}
1423
1424/**
1425 * nfsd4_run_cb - queue up a callback job to run
1426 * @cb: callback to queue
1427 *
1428 * Kick off a callback to do its thing. Returns false if it was already
1429 * on a queue, true otherwise.
1430 */
1431bool nfsd4_run_cb(struct nfsd4_callback *cb)
1432{
1433 struct nfs4_client *clp = cb->cb_clp;
1434 bool queued;
1435
1436 nfsd41_cb_inflight_begin(clp);
1437 queued = nfsd4_queue_cb(cb);
1438 if (!queued)
1439 nfsd41_cb_inflight_end(clp);
1440 return queued;
1441}