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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/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
79/*
80 * nfs_cb_opnum4
81 *
82 * enum nfs_cb_opnum4 {
83 * OP_CB_GETATTR = 3,
84 * ...
85 * };
86 */
87enum nfs_cb_opnum4 {
88 OP_CB_GETATTR = 3,
89 OP_CB_RECALL = 4,
90 OP_CB_LAYOUTRECALL = 5,
91 OP_CB_NOTIFY = 6,
92 OP_CB_PUSH_DELEG = 7,
93 OP_CB_RECALL_ANY = 8,
94 OP_CB_RECALLABLE_OBJ_AVAIL = 9,
95 OP_CB_RECALL_SLOT = 10,
96 OP_CB_SEQUENCE = 11,
97 OP_CB_WANTS_CANCELLED = 12,
98 OP_CB_NOTIFY_LOCK = 13,
99 OP_CB_NOTIFY_DEVICEID = 14,
100 OP_CB_OFFLOAD = 15,
101 OP_CB_ILLEGAL = 10044
102};
103
104static void encode_nfs_cb_opnum4(struct xdr_stream *xdr, enum nfs_cb_opnum4 op)
105{
106 __be32 *p;
107
108 p = xdr_reserve_space(xdr, 4);
109 *p = cpu_to_be32(op);
110}
111
112/*
113 * nfs_fh4
114 *
115 * typedef opaque nfs_fh4<NFS4_FHSIZE>;
116 */
117static void encode_nfs_fh4(struct xdr_stream *xdr, const struct knfsd_fh *fh)
118{
119 u32 length = fh->fh_size;
120 __be32 *p;
121
122 BUG_ON(length > NFS4_FHSIZE);
123 p = xdr_reserve_space(xdr, 4 + length);
124 xdr_encode_opaque(p, &fh->fh_base, length);
125}
126
127/*
128 * stateid4
129 *
130 * struct stateid4 {
131 * uint32_t seqid;
132 * opaque other[12];
133 * };
134 */
135static void encode_stateid4(struct xdr_stream *xdr, const stateid_t *sid)
136{
137 __be32 *p;
138
139 p = xdr_reserve_space(xdr, NFS4_STATEID_SIZE);
140 *p++ = cpu_to_be32(sid->si_generation);
141 xdr_encode_opaque_fixed(p, &sid->si_opaque, NFS4_STATEID_OTHER_SIZE);
142}
143
144/*
145 * sessionid4
146 *
147 * typedef opaque sessionid4[NFS4_SESSIONID_SIZE];
148 */
149static void encode_sessionid4(struct xdr_stream *xdr,
150 const struct nfsd4_session *session)
151{
152 __be32 *p;
153
154 p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN);
155 xdr_encode_opaque_fixed(p, session->se_sessionid.data,
156 NFS4_MAX_SESSIONID_LEN);
157}
158
159/*
160 * nfsstat4
161 */
162static const struct {
163 int stat;
164 int errno;
165} nfs_cb_errtbl[] = {
166 { NFS4_OK, 0 },
167 { NFS4ERR_PERM, -EPERM },
168 { NFS4ERR_NOENT, -ENOENT },
169 { NFS4ERR_IO, -EIO },
170 { NFS4ERR_NXIO, -ENXIO },
171 { NFS4ERR_ACCESS, -EACCES },
172 { NFS4ERR_EXIST, -EEXIST },
173 { NFS4ERR_XDEV, -EXDEV },
174 { NFS4ERR_NOTDIR, -ENOTDIR },
175 { NFS4ERR_ISDIR, -EISDIR },
176 { NFS4ERR_INVAL, -EINVAL },
177 { NFS4ERR_FBIG, -EFBIG },
178 { NFS4ERR_NOSPC, -ENOSPC },
179 { NFS4ERR_ROFS, -EROFS },
180 { NFS4ERR_MLINK, -EMLINK },
181 { NFS4ERR_NAMETOOLONG, -ENAMETOOLONG },
182 { NFS4ERR_NOTEMPTY, -ENOTEMPTY },
183 { NFS4ERR_DQUOT, -EDQUOT },
184 { NFS4ERR_STALE, -ESTALE },
185 { NFS4ERR_BADHANDLE, -EBADHANDLE },
186 { NFS4ERR_BAD_COOKIE, -EBADCOOKIE },
187 { NFS4ERR_NOTSUPP, -ENOTSUPP },
188 { NFS4ERR_TOOSMALL, -ETOOSMALL },
189 { NFS4ERR_SERVERFAULT, -ESERVERFAULT },
190 { NFS4ERR_BADTYPE, -EBADTYPE },
191 { NFS4ERR_LOCKED, -EAGAIN },
192 { NFS4ERR_RESOURCE, -EREMOTEIO },
193 { NFS4ERR_SYMLINK, -ELOOP },
194 { NFS4ERR_OP_ILLEGAL, -EOPNOTSUPP },
195 { NFS4ERR_DEADLOCK, -EDEADLK },
196 { -1, -EIO }
197};
198
199/*
200 * If we cannot translate the error, the recovery routines should
201 * handle it.
202 *
203 * Note: remaining NFSv4 error codes have values > 10000, so should
204 * not conflict with native Linux error codes.
205 */
206static int nfs_cb_stat_to_errno(int status)
207{
208 int i;
209
210 for (i = 0; nfs_cb_errtbl[i].stat != -1; i++) {
211 if (nfs_cb_errtbl[i].stat == status)
212 return nfs_cb_errtbl[i].errno;
213 }
214
215 dprintk("NFSD: Unrecognized NFS CB status value: %u\n", status);
216 return -status;
217}
218
219static int decode_cb_op_status(struct xdr_stream *xdr,
220 enum nfs_cb_opnum4 expected, int *status)
221{
222 __be32 *p;
223 u32 op;
224
225 p = xdr_inline_decode(xdr, 4 + 4);
226 if (unlikely(p == NULL))
227 goto out_overflow;
228 op = be32_to_cpup(p++);
229 if (unlikely(op != expected))
230 goto out_unexpected;
231 *status = nfs_cb_stat_to_errno(be32_to_cpup(p));
232 return 0;
233out_overflow:
234 return -EIO;
235out_unexpected:
236 dprintk("NFSD: Callback server returned operation %d but "
237 "we issued a request for %d\n", op, expected);
238 return -EIO;
239}
240
241/*
242 * CB_COMPOUND4args
243 *
244 * struct CB_COMPOUND4args {
245 * utf8str_cs tag;
246 * uint32_t minorversion;
247 * uint32_t callback_ident;
248 * nfs_cb_argop4 argarray<>;
249 * };
250*/
251static void encode_cb_compound4args(struct xdr_stream *xdr,
252 struct nfs4_cb_compound_hdr *hdr)
253{
254 __be32 * p;
255
256 p = xdr_reserve_space(xdr, 4 + 4 + 4 + 4);
257 p = xdr_encode_empty_array(p); /* empty tag */
258 *p++ = cpu_to_be32(hdr->minorversion);
259 *p++ = cpu_to_be32(hdr->ident);
260
261 hdr->nops_p = p;
262 *p = cpu_to_be32(hdr->nops); /* argarray element count */
263}
264
265/*
266 * Update argarray element count
267 */
268static void encode_cb_nops(struct nfs4_cb_compound_hdr *hdr)
269{
270 BUG_ON(hdr->nops > NFS4_MAX_BACK_CHANNEL_OPS);
271 *hdr->nops_p = cpu_to_be32(hdr->nops);
272}
273
274/*
275 * CB_COMPOUND4res
276 *
277 * struct CB_COMPOUND4res {
278 * nfsstat4 status;
279 * utf8str_cs tag;
280 * nfs_cb_resop4 resarray<>;
281 * };
282 */
283static int decode_cb_compound4res(struct xdr_stream *xdr,
284 struct nfs4_cb_compound_hdr *hdr)
285{
286 u32 length;
287 __be32 *p;
288
289 p = xdr_inline_decode(xdr, 4 + 4);
290 if (unlikely(p == NULL))
291 goto out_overflow;
292 hdr->status = be32_to_cpup(p++);
293 /* Ignore the tag */
294 length = be32_to_cpup(p++);
295 p = xdr_inline_decode(xdr, length + 4);
296 if (unlikely(p == NULL))
297 goto out_overflow;
298 p += XDR_QUADLEN(length);
299 hdr->nops = be32_to_cpup(p);
300 return 0;
301out_overflow:
302 return -EIO;
303}
304
305/*
306 * CB_RECALL4args
307 *
308 * struct CB_RECALL4args {
309 * stateid4 stateid;
310 * bool truncate;
311 * nfs_fh4 fh;
312 * };
313 */
314static void encode_cb_recall4args(struct xdr_stream *xdr,
315 const struct nfs4_delegation *dp,
316 struct nfs4_cb_compound_hdr *hdr)
317{
318 __be32 *p;
319
320 encode_nfs_cb_opnum4(xdr, OP_CB_RECALL);
321 encode_stateid4(xdr, &dp->dl_stid.sc_stateid);
322
323 p = xdr_reserve_space(xdr, 4);
324 *p++ = xdr_zero; /* truncate */
325
326 encode_nfs_fh4(xdr, &dp->dl_stid.sc_file->fi_fhandle);
327
328 hdr->nops++;
329}
330
331/*
332 * CB_SEQUENCE4args
333 *
334 * struct CB_SEQUENCE4args {
335 * sessionid4 csa_sessionid;
336 * sequenceid4 csa_sequenceid;
337 * slotid4 csa_slotid;
338 * slotid4 csa_highest_slotid;
339 * bool csa_cachethis;
340 * referring_call_list4 csa_referring_call_lists<>;
341 * };
342 */
343static void encode_cb_sequence4args(struct xdr_stream *xdr,
344 const struct nfsd4_callback *cb,
345 struct nfs4_cb_compound_hdr *hdr)
346{
347 struct nfsd4_session *session = cb->cb_clp->cl_cb_session;
348 __be32 *p;
349
350 if (hdr->minorversion == 0)
351 return;
352
353 encode_nfs_cb_opnum4(xdr, OP_CB_SEQUENCE);
354 encode_sessionid4(xdr, session);
355
356 p = xdr_reserve_space(xdr, 4 + 4 + 4 + 4 + 4);
357 *p++ = cpu_to_be32(session->se_cb_seq_nr); /* csa_sequenceid */
358 *p++ = xdr_zero; /* csa_slotid */
359 *p++ = xdr_zero; /* csa_highest_slotid */
360 *p++ = xdr_zero; /* csa_cachethis */
361 xdr_encode_empty_array(p); /* csa_referring_call_lists */
362
363 hdr->nops++;
364}
365
366/*
367 * CB_SEQUENCE4resok
368 *
369 * struct CB_SEQUENCE4resok {
370 * sessionid4 csr_sessionid;
371 * sequenceid4 csr_sequenceid;
372 * slotid4 csr_slotid;
373 * slotid4 csr_highest_slotid;
374 * slotid4 csr_target_highest_slotid;
375 * };
376 *
377 * union CB_SEQUENCE4res switch (nfsstat4 csr_status) {
378 * case NFS4_OK:
379 * CB_SEQUENCE4resok csr_resok4;
380 * default:
381 * void;
382 * };
383 *
384 * Our current back channel implmentation supports a single backchannel
385 * with a single slot.
386 */
387static int decode_cb_sequence4resok(struct xdr_stream *xdr,
388 struct nfsd4_callback *cb)
389{
390 struct nfsd4_session *session = cb->cb_clp->cl_cb_session;
391 int status = -ESERVERFAULT;
392 __be32 *p;
393 u32 dummy;
394
395 /*
396 * If the server returns different values for sessionID, slotID or
397 * sequence number, the server is looney tunes.
398 */
399 p = xdr_inline_decode(xdr, NFS4_MAX_SESSIONID_LEN + 4 + 4 + 4 + 4);
400 if (unlikely(p == NULL))
401 goto out_overflow;
402
403 if (memcmp(p, session->se_sessionid.data, NFS4_MAX_SESSIONID_LEN)) {
404 dprintk("NFS: %s Invalid session id\n", __func__);
405 goto out;
406 }
407 p += XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN);
408
409 dummy = be32_to_cpup(p++);
410 if (dummy != session->se_cb_seq_nr) {
411 dprintk("NFS: %s Invalid sequence number\n", __func__);
412 goto out;
413 }
414
415 dummy = be32_to_cpup(p++);
416 if (dummy != 0) {
417 dprintk("NFS: %s Invalid slotid\n", __func__);
418 goto out;
419 }
420
421 /*
422 * FIXME: process highest slotid and target highest slotid
423 */
424 status = 0;
425out:
426 cb->cb_seq_status = status;
427 return status;
428out_overflow:
429 status = -EIO;
430 goto out;
431}
432
433static int decode_cb_sequence4res(struct xdr_stream *xdr,
434 struct nfsd4_callback *cb)
435{
436 int status;
437
438 if (cb->cb_clp->cl_minorversion == 0)
439 return 0;
440
441 status = decode_cb_op_status(xdr, OP_CB_SEQUENCE, &cb->cb_seq_status);
442 if (unlikely(status || cb->cb_seq_status))
443 return status;
444
445 return decode_cb_sequence4resok(xdr, cb);
446}
447
448/*
449 * NFSv4.0 and NFSv4.1 XDR encode functions
450 *
451 * NFSv4.0 callback argument types are defined in section 15 of RFC
452 * 3530: "Network File System (NFS) version 4 Protocol" and section 20
453 * of RFC 5661: "Network File System (NFS) Version 4 Minor Version 1
454 * Protocol".
455 */
456
457/*
458 * NB: Without this zero space reservation, callbacks over krb5p fail
459 */
460static void nfs4_xdr_enc_cb_null(struct rpc_rqst *req, struct xdr_stream *xdr,
461 const void *__unused)
462{
463 xdr_reserve_space(xdr, 0);
464}
465
466/*
467 * 20.2. Operation 4: CB_RECALL - Recall a Delegation
468 */
469static void nfs4_xdr_enc_cb_recall(struct rpc_rqst *req, struct xdr_stream *xdr,
470 const void *data)
471{
472 const struct nfsd4_callback *cb = data;
473 const struct nfs4_delegation *dp = cb_to_delegation(cb);
474 struct nfs4_cb_compound_hdr hdr = {
475 .ident = cb->cb_clp->cl_cb_ident,
476 .minorversion = cb->cb_clp->cl_minorversion,
477 };
478
479 encode_cb_compound4args(xdr, &hdr);
480 encode_cb_sequence4args(xdr, cb, &hdr);
481 encode_cb_recall4args(xdr, dp, &hdr);
482 encode_cb_nops(&hdr);
483}
484
485
486/*
487 * NFSv4.0 and NFSv4.1 XDR decode functions
488 *
489 * NFSv4.0 callback result types are defined in section 15 of RFC
490 * 3530: "Network File System (NFS) version 4 Protocol" and section 20
491 * of RFC 5661: "Network File System (NFS) Version 4 Minor Version 1
492 * Protocol".
493 */
494
495static int nfs4_xdr_dec_cb_null(struct rpc_rqst *req, struct xdr_stream *xdr,
496 void *__unused)
497{
498 return 0;
499}
500
501/*
502 * 20.2. Operation 4: CB_RECALL - Recall a Delegation
503 */
504static int nfs4_xdr_dec_cb_recall(struct rpc_rqst *rqstp,
505 struct xdr_stream *xdr,
506 void *data)
507{
508 struct nfsd4_callback *cb = data;
509 struct nfs4_cb_compound_hdr hdr;
510 int status;
511
512 status = decode_cb_compound4res(xdr, &hdr);
513 if (unlikely(status))
514 return status;
515
516 status = decode_cb_sequence4res(xdr, cb);
517 if (unlikely(status || cb->cb_seq_status))
518 return status;
519
520 return decode_cb_op_status(xdr, OP_CB_RECALL, &cb->cb_status);
521}
522
523#ifdef CONFIG_NFSD_PNFS
524/*
525 * CB_LAYOUTRECALL4args
526 *
527 * struct layoutrecall_file4 {
528 * nfs_fh4 lor_fh;
529 * offset4 lor_offset;
530 * length4 lor_length;
531 * stateid4 lor_stateid;
532 * };
533 *
534 * union layoutrecall4 switch(layoutrecall_type4 lor_recalltype) {
535 * case LAYOUTRECALL4_FILE:
536 * layoutrecall_file4 lor_layout;
537 * case LAYOUTRECALL4_FSID:
538 * fsid4 lor_fsid;
539 * case LAYOUTRECALL4_ALL:
540 * void;
541 * };
542 *
543 * struct CB_LAYOUTRECALL4args {
544 * layouttype4 clora_type;
545 * layoutiomode4 clora_iomode;
546 * bool clora_changed;
547 * layoutrecall4 clora_recall;
548 * };
549 */
550static void encode_cb_layout4args(struct xdr_stream *xdr,
551 const struct nfs4_layout_stateid *ls,
552 struct nfs4_cb_compound_hdr *hdr)
553{
554 __be32 *p;
555
556 BUG_ON(hdr->minorversion == 0);
557
558 p = xdr_reserve_space(xdr, 5 * 4);
559 *p++ = cpu_to_be32(OP_CB_LAYOUTRECALL);
560 *p++ = cpu_to_be32(ls->ls_layout_type);
561 *p++ = cpu_to_be32(IOMODE_ANY);
562 *p++ = cpu_to_be32(1);
563 *p = cpu_to_be32(RETURN_FILE);
564
565 encode_nfs_fh4(xdr, &ls->ls_stid.sc_file->fi_fhandle);
566
567 p = xdr_reserve_space(xdr, 2 * 8);
568 p = xdr_encode_hyper(p, 0);
569 xdr_encode_hyper(p, NFS4_MAX_UINT64);
570
571 encode_stateid4(xdr, &ls->ls_recall_sid);
572
573 hdr->nops++;
574}
575
576static void nfs4_xdr_enc_cb_layout(struct rpc_rqst *req,
577 struct xdr_stream *xdr,
578 const void *data)
579{
580 const struct nfsd4_callback *cb = data;
581 const struct nfs4_layout_stateid *ls =
582 container_of(cb, struct nfs4_layout_stateid, ls_recall);
583 struct nfs4_cb_compound_hdr hdr = {
584 .ident = 0,
585 .minorversion = cb->cb_clp->cl_minorversion,
586 };
587
588 encode_cb_compound4args(xdr, &hdr);
589 encode_cb_sequence4args(xdr, cb, &hdr);
590 encode_cb_layout4args(xdr, ls, &hdr);
591 encode_cb_nops(&hdr);
592}
593
594static int nfs4_xdr_dec_cb_layout(struct rpc_rqst *rqstp,
595 struct xdr_stream *xdr,
596 void *data)
597{
598 struct nfsd4_callback *cb = data;
599 struct nfs4_cb_compound_hdr hdr;
600 int status;
601
602 status = decode_cb_compound4res(xdr, &hdr);
603 if (unlikely(status))
604 return status;
605
606 status = decode_cb_sequence4res(xdr, cb);
607 if (unlikely(status || cb->cb_seq_status))
608 return status;
609
610 return decode_cb_op_status(xdr, OP_CB_LAYOUTRECALL, &cb->cb_status);
611}
612#endif /* CONFIG_NFSD_PNFS */
613
614static void encode_stateowner(struct xdr_stream *xdr, struct nfs4_stateowner *so)
615{
616 __be32 *p;
617
618 p = xdr_reserve_space(xdr, 8 + 4 + so->so_owner.len);
619 p = xdr_encode_opaque_fixed(p, &so->so_client->cl_clientid, 8);
620 xdr_encode_opaque(p, so->so_owner.data, so->so_owner.len);
621}
622
623static void nfs4_xdr_enc_cb_notify_lock(struct rpc_rqst *req,
624 struct xdr_stream *xdr,
625 const void *data)
626{
627 const struct nfsd4_callback *cb = data;
628 const struct nfsd4_blocked_lock *nbl =
629 container_of(cb, struct nfsd4_blocked_lock, nbl_cb);
630 struct nfs4_lockowner *lo = (struct nfs4_lockowner *)nbl->nbl_lock.fl_owner;
631 struct nfs4_cb_compound_hdr hdr = {
632 .ident = 0,
633 .minorversion = cb->cb_clp->cl_minorversion,
634 };
635
636 __be32 *p;
637
638 BUG_ON(hdr.minorversion == 0);
639
640 encode_cb_compound4args(xdr, &hdr);
641 encode_cb_sequence4args(xdr, cb, &hdr);
642
643 p = xdr_reserve_space(xdr, 4);
644 *p = cpu_to_be32(OP_CB_NOTIFY_LOCK);
645 encode_nfs_fh4(xdr, &nbl->nbl_fh);
646 encode_stateowner(xdr, &lo->lo_owner);
647 hdr.nops++;
648
649 encode_cb_nops(&hdr);
650}
651
652static int nfs4_xdr_dec_cb_notify_lock(struct rpc_rqst *rqstp,
653 struct xdr_stream *xdr,
654 void *data)
655{
656 struct nfsd4_callback *cb = data;
657 struct nfs4_cb_compound_hdr hdr;
658 int status;
659
660 status = decode_cb_compound4res(xdr, &hdr);
661 if (unlikely(status))
662 return status;
663
664 status = decode_cb_sequence4res(xdr, cb);
665 if (unlikely(status || cb->cb_seq_status))
666 return status;
667
668 return decode_cb_op_status(xdr, OP_CB_NOTIFY_LOCK, &cb->cb_status);
669}
670
671/*
672 * struct write_response4 {
673 * stateid4 wr_callback_id<1>;
674 * length4 wr_count;
675 * stable_how4 wr_committed;
676 * verifier4 wr_writeverf;
677 * };
678 * union offload_info4 switch (nfsstat4 coa_status) {
679 * case NFS4_OK:
680 * write_response4 coa_resok4;
681 * default:
682 * length4 coa_bytes_copied;
683 * };
684 * struct CB_OFFLOAD4args {
685 * nfs_fh4 coa_fh;
686 * stateid4 coa_stateid;
687 * offload_info4 coa_offload_info;
688 * };
689 */
690static void encode_offload_info4(struct xdr_stream *xdr,
691 __be32 nfserr,
692 const struct nfsd4_copy *cp)
693{
694 __be32 *p;
695
696 p = xdr_reserve_space(xdr, 4);
697 *p++ = nfserr;
698 if (!nfserr) {
699 p = xdr_reserve_space(xdr, 4 + 8 + 4 + NFS4_VERIFIER_SIZE);
700 p = xdr_encode_empty_array(p);
701 p = xdr_encode_hyper(p, cp->cp_res.wr_bytes_written);
702 *p++ = cpu_to_be32(cp->cp_res.wr_stable_how);
703 p = xdr_encode_opaque_fixed(p, cp->cp_res.wr_verifier.data,
704 NFS4_VERIFIER_SIZE);
705 } else {
706 p = xdr_reserve_space(xdr, 8);
707 /* We always return success if bytes were written */
708 p = xdr_encode_hyper(p, 0);
709 }
710}
711
712static void encode_cb_offload4args(struct xdr_stream *xdr,
713 __be32 nfserr,
714 const struct knfsd_fh *fh,
715 const struct nfsd4_copy *cp,
716 struct nfs4_cb_compound_hdr *hdr)
717{
718 __be32 *p;
719
720 p = xdr_reserve_space(xdr, 4);
721 *p++ = cpu_to_be32(OP_CB_OFFLOAD);
722 encode_nfs_fh4(xdr, fh);
723 encode_stateid4(xdr, &cp->cp_res.cb_stateid);
724 encode_offload_info4(xdr, nfserr, cp);
725
726 hdr->nops++;
727}
728
729static void nfs4_xdr_enc_cb_offload(struct rpc_rqst *req,
730 struct xdr_stream *xdr,
731 const void *data)
732{
733 const struct nfsd4_callback *cb = data;
734 const struct nfsd4_copy *cp =
735 container_of(cb, struct nfsd4_copy, cp_cb);
736 struct nfs4_cb_compound_hdr hdr = {
737 .ident = 0,
738 .minorversion = cb->cb_clp->cl_minorversion,
739 };
740
741 encode_cb_compound4args(xdr, &hdr);
742 encode_cb_sequence4args(xdr, cb, &hdr);
743 encode_cb_offload4args(xdr, cp->nfserr, &cp->fh, cp, &hdr);
744 encode_cb_nops(&hdr);
745}
746
747static int nfs4_xdr_dec_cb_offload(struct rpc_rqst *rqstp,
748 struct xdr_stream *xdr,
749 void *data)
750{
751 struct nfsd4_callback *cb = data;
752 struct nfs4_cb_compound_hdr hdr;
753 int status;
754
755 status = decode_cb_compound4res(xdr, &hdr);
756 if (unlikely(status))
757 return status;
758
759 status = decode_cb_sequence4res(xdr, cb);
760 if (unlikely(status || cb->cb_seq_status))
761 return status;
762
763 return decode_cb_op_status(xdr, OP_CB_OFFLOAD, &cb->cb_status);
764}
765/*
766 * RPC procedure tables
767 */
768#define PROC(proc, call, argtype, restype) \
769[NFSPROC4_CLNT_##proc] = { \
770 .p_proc = NFSPROC4_CB_##call, \
771 .p_encode = nfs4_xdr_enc_##argtype, \
772 .p_decode = nfs4_xdr_dec_##restype, \
773 .p_arglen = NFS4_enc_##argtype##_sz, \
774 .p_replen = NFS4_dec_##restype##_sz, \
775 .p_statidx = NFSPROC4_CB_##call, \
776 .p_name = #proc, \
777}
778
779static const struct rpc_procinfo nfs4_cb_procedures[] = {
780 PROC(CB_NULL, NULL, cb_null, cb_null),
781 PROC(CB_RECALL, COMPOUND, cb_recall, cb_recall),
782#ifdef CONFIG_NFSD_PNFS
783 PROC(CB_LAYOUT, COMPOUND, cb_layout, cb_layout),
784#endif
785 PROC(CB_NOTIFY_LOCK, COMPOUND, cb_notify_lock, cb_notify_lock),
786 PROC(CB_OFFLOAD, COMPOUND, cb_offload, cb_offload),
787};
788
789static unsigned int nfs4_cb_counts[ARRAY_SIZE(nfs4_cb_procedures)];
790static const struct rpc_version nfs_cb_version4 = {
791/*
792 * Note on the callback rpc program version number: despite language in rfc
793 * 5661 section 18.36.3 requiring servers to use 4 in this field, the
794 * official xdr descriptions for both 4.0 and 4.1 specify version 1, and
795 * in practice that appears to be what implementations use. The section
796 * 18.36.3 language is expected to be fixed in an erratum.
797 */
798 .number = 1,
799 .nrprocs = ARRAY_SIZE(nfs4_cb_procedures),
800 .procs = nfs4_cb_procedures,
801 .counts = nfs4_cb_counts,
802};
803
804static const struct rpc_version *nfs_cb_version[2] = {
805 [1] = &nfs_cb_version4,
806};
807
808static const struct rpc_program cb_program;
809
810static struct rpc_stat cb_stats = {
811 .program = &cb_program
812};
813
814#define NFS4_CALLBACK 0x40000000
815static const struct rpc_program cb_program = {
816 .name = "nfs4_cb",
817 .number = NFS4_CALLBACK,
818 .nrvers = ARRAY_SIZE(nfs_cb_version),
819 .version = nfs_cb_version,
820 .stats = &cb_stats,
821 .pipe_dir_name = "nfsd4_cb",
822};
823
824static int max_cb_time(struct net *net)
825{
826 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
827
828 /*
829 * nfsd4_lease is set to at most one hour in __nfsd4_write_time,
830 * so we can use 32-bit math on it. Warn if that assumption
831 * ever stops being true.
832 */
833 if (WARN_ON_ONCE(nn->nfsd4_lease > 3600))
834 return 360 * HZ;
835
836 return max(((u32)nn->nfsd4_lease)/10, 1u) * HZ;
837}
838
839static struct workqueue_struct *callback_wq;
840
841static bool nfsd4_queue_cb(struct nfsd4_callback *cb)
842{
843 return queue_work(callback_wq, &cb->cb_work);
844}
845
846static void nfsd41_cb_inflight_begin(struct nfs4_client *clp)
847{
848 atomic_inc(&clp->cl_cb_inflight);
849}
850
851static void nfsd41_cb_inflight_end(struct nfs4_client *clp)
852{
853
854 if (atomic_dec_and_test(&clp->cl_cb_inflight))
855 wake_up_var(&clp->cl_cb_inflight);
856}
857
858static void nfsd41_cb_inflight_wait_complete(struct nfs4_client *clp)
859{
860 wait_var_event(&clp->cl_cb_inflight,
861 !atomic_read(&clp->cl_cb_inflight));
862}
863
864static const struct cred *get_backchannel_cred(struct nfs4_client *clp, struct rpc_clnt *client, struct nfsd4_session *ses)
865{
866 if (clp->cl_minorversion == 0) {
867 client->cl_principal = clp->cl_cred.cr_targ_princ ?
868 clp->cl_cred.cr_targ_princ : "nfs";
869
870 return get_cred(rpc_machine_cred());
871 } else {
872 struct cred *kcred;
873
874 kcred = prepare_kernel_cred(NULL);
875 if (!kcred)
876 return NULL;
877
878 kcred->uid = ses->se_cb_sec.uid;
879 kcred->gid = ses->se_cb_sec.gid;
880 return kcred;
881 }
882}
883
884static int setup_callback_client(struct nfs4_client *clp, struct nfs4_cb_conn *conn, struct nfsd4_session *ses)
885{
886 int maxtime = max_cb_time(clp->net);
887 struct rpc_timeout timeparms = {
888 .to_initval = maxtime,
889 .to_retries = 0,
890 .to_maxval = maxtime,
891 };
892 struct rpc_create_args args = {
893 .net = clp->net,
894 .address = (struct sockaddr *) &conn->cb_addr,
895 .addrsize = conn->cb_addrlen,
896 .saddress = (struct sockaddr *) &conn->cb_saddr,
897 .timeout = &timeparms,
898 .program = &cb_program,
899 .version = 1,
900 .flags = (RPC_CLNT_CREATE_NOPING | RPC_CLNT_CREATE_QUIET),
901 .cred = current_cred(),
902 };
903 struct rpc_clnt *client;
904 const struct cred *cred;
905
906 if (clp->cl_minorversion == 0) {
907 if (!clp->cl_cred.cr_principal &&
908 (clp->cl_cred.cr_flavor >= RPC_AUTH_GSS_KRB5)) {
909 trace_nfsd_cb_setup_err(clp, -EINVAL);
910 return -EINVAL;
911 }
912 args.client_name = clp->cl_cred.cr_principal;
913 args.prognumber = conn->cb_prog;
914 args.protocol = XPRT_TRANSPORT_TCP;
915 args.authflavor = clp->cl_cred.cr_flavor;
916 clp->cl_cb_ident = conn->cb_ident;
917 } else {
918 if (!conn->cb_xprt) {
919 trace_nfsd_cb_setup_err(clp, -EINVAL);
920 return -EINVAL;
921 }
922 clp->cl_cb_conn.cb_xprt = conn->cb_xprt;
923 clp->cl_cb_session = ses;
924 args.bc_xprt = conn->cb_xprt;
925 args.prognumber = clp->cl_cb_session->se_cb_prog;
926 args.protocol = conn->cb_xprt->xpt_class->xcl_ident |
927 XPRT_TRANSPORT_BC;
928 args.authflavor = ses->se_cb_sec.flavor;
929 }
930 /* Create RPC client */
931 client = rpc_create(&args);
932 if (IS_ERR(client)) {
933 trace_nfsd_cb_setup_err(clp, PTR_ERR(client));
934 return PTR_ERR(client);
935 }
936 cred = get_backchannel_cred(clp, client, ses);
937 if (!cred) {
938 trace_nfsd_cb_setup_err(clp, -ENOMEM);
939 rpc_shutdown_client(client);
940 return -ENOMEM;
941 }
942 clp->cl_cb_client = client;
943 clp->cl_cb_cred = cred;
944 trace_nfsd_cb_setup(clp);
945 return 0;
946}
947
948static void nfsd4_mark_cb_down(struct nfs4_client *clp, int reason)
949{
950 if (test_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags))
951 return;
952 clp->cl_cb_state = NFSD4_CB_DOWN;
953 trace_nfsd_cb_state(clp);
954}
955
956static void nfsd4_mark_cb_fault(struct nfs4_client *clp, int reason)
957{
958 if (test_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags))
959 return;
960 clp->cl_cb_state = NFSD4_CB_FAULT;
961 trace_nfsd_cb_state(clp);
962}
963
964static void nfsd4_cb_probe_done(struct rpc_task *task, void *calldata)
965{
966 struct nfs4_client *clp = container_of(calldata, struct nfs4_client, cl_cb_null);
967
968 trace_nfsd_cb_done(clp, task->tk_status);
969 if (task->tk_status)
970 nfsd4_mark_cb_down(clp, task->tk_status);
971 else {
972 clp->cl_cb_state = NFSD4_CB_UP;
973 trace_nfsd_cb_state(clp);
974 }
975}
976
977static void nfsd4_cb_probe_release(void *calldata)
978{
979 struct nfs4_client *clp = container_of(calldata, struct nfs4_client, cl_cb_null);
980
981 nfsd41_cb_inflight_end(clp);
982
983}
984
985static const struct rpc_call_ops nfsd4_cb_probe_ops = {
986 /* XXX: release method to ensure we set the cb channel down if
987 * necessary on early failure? */
988 .rpc_call_done = nfsd4_cb_probe_done,
989 .rpc_release = nfsd4_cb_probe_release,
990};
991
992/*
993 * Poke the callback thread to process any updates to the callback
994 * parameters, and send a null probe.
995 */
996void nfsd4_probe_callback(struct nfs4_client *clp)
997{
998 clp->cl_cb_state = NFSD4_CB_UNKNOWN;
999 trace_nfsd_cb_state(clp);
1000 set_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags);
1001 nfsd4_run_cb(&clp->cl_cb_null);
1002}
1003
1004void nfsd4_probe_callback_sync(struct nfs4_client *clp)
1005{
1006 nfsd4_probe_callback(clp);
1007 flush_workqueue(callback_wq);
1008}
1009
1010void nfsd4_change_callback(struct nfs4_client *clp, struct nfs4_cb_conn *conn)
1011{
1012 clp->cl_cb_state = NFSD4_CB_UNKNOWN;
1013 spin_lock(&clp->cl_lock);
1014 memcpy(&clp->cl_cb_conn, conn, sizeof(struct nfs4_cb_conn));
1015 spin_unlock(&clp->cl_lock);
1016 trace_nfsd_cb_state(clp);
1017}
1018
1019/*
1020 * There's currently a single callback channel slot.
1021 * If the slot is available, then mark it busy. Otherwise, set the
1022 * thread for sleeping on the callback RPC wait queue.
1023 */
1024static bool nfsd41_cb_get_slot(struct nfsd4_callback *cb, struct rpc_task *task)
1025{
1026 struct nfs4_client *clp = cb->cb_clp;
1027
1028 if (!cb->cb_holds_slot &&
1029 test_and_set_bit(0, &clp->cl_cb_slot_busy) != 0) {
1030 rpc_sleep_on(&clp->cl_cb_waitq, task, NULL);
1031 /* Race breaker */
1032 if (test_and_set_bit(0, &clp->cl_cb_slot_busy) != 0) {
1033 dprintk("%s slot is busy\n", __func__);
1034 return false;
1035 }
1036 rpc_wake_up_queued_task(&clp->cl_cb_waitq, task);
1037 }
1038 cb->cb_holds_slot = true;
1039 return true;
1040}
1041
1042static void nfsd41_cb_release_slot(struct nfsd4_callback *cb)
1043{
1044 struct nfs4_client *clp = cb->cb_clp;
1045
1046 if (cb->cb_holds_slot) {
1047 cb->cb_holds_slot = false;
1048 clear_bit(0, &clp->cl_cb_slot_busy);
1049 rpc_wake_up_next(&clp->cl_cb_waitq);
1050 }
1051}
1052
1053static void nfsd41_destroy_cb(struct nfsd4_callback *cb)
1054{
1055 struct nfs4_client *clp = cb->cb_clp;
1056
1057 nfsd41_cb_release_slot(cb);
1058 if (cb->cb_ops && cb->cb_ops->release)
1059 cb->cb_ops->release(cb);
1060 nfsd41_cb_inflight_end(clp);
1061}
1062
1063/*
1064 * TODO: cb_sequence should support referring call lists, cachethis, multiple
1065 * slots, and mark callback channel down on communication errors.
1066 */
1067static void nfsd4_cb_prepare(struct rpc_task *task, void *calldata)
1068{
1069 struct nfsd4_callback *cb = calldata;
1070 struct nfs4_client *clp = cb->cb_clp;
1071 u32 minorversion = clp->cl_minorversion;
1072
1073 /*
1074 * cb_seq_status is only set in decode_cb_sequence4res,
1075 * and so will remain 1 if an rpc level failure occurs.
1076 */
1077 cb->cb_seq_status = 1;
1078 cb->cb_status = 0;
1079 if (minorversion && !nfsd41_cb_get_slot(cb, task))
1080 return;
1081 rpc_call_start(task);
1082}
1083
1084static bool nfsd4_cb_sequence_done(struct rpc_task *task, struct nfsd4_callback *cb)
1085{
1086 struct nfs4_client *clp = cb->cb_clp;
1087 struct nfsd4_session *session = clp->cl_cb_session;
1088 bool ret = true;
1089
1090 if (!clp->cl_minorversion) {
1091 /*
1092 * If the backchannel connection was shut down while this
1093 * task was queued, we need to resubmit it after setting up
1094 * a new backchannel connection.
1095 *
1096 * Note that if we lost our callback connection permanently
1097 * the submission code will error out, so we don't need to
1098 * handle that case here.
1099 */
1100 if (RPC_SIGNALLED(task))
1101 goto need_restart;
1102
1103 return true;
1104 }
1105
1106 if (!cb->cb_holds_slot)
1107 goto need_restart;
1108
1109 switch (cb->cb_seq_status) {
1110 case 0:
1111 /*
1112 * No need for lock, access serialized in nfsd4_cb_prepare
1113 *
1114 * RFC5661 20.9.3
1115 * If CB_SEQUENCE returns an error, then the state of the slot
1116 * (sequence ID, cached reply) MUST NOT change.
1117 */
1118 ++session->se_cb_seq_nr;
1119 break;
1120 case -ESERVERFAULT:
1121 ++session->se_cb_seq_nr;
1122 fallthrough;
1123 case 1:
1124 case -NFS4ERR_BADSESSION:
1125 nfsd4_mark_cb_fault(cb->cb_clp, cb->cb_seq_status);
1126 ret = false;
1127 break;
1128 case -NFS4ERR_DELAY:
1129 if (!rpc_restart_call(task))
1130 goto out;
1131
1132 rpc_delay(task, 2 * HZ);
1133 return false;
1134 case -NFS4ERR_BADSLOT:
1135 goto retry_nowait;
1136 case -NFS4ERR_SEQ_MISORDERED:
1137 if (session->se_cb_seq_nr != 1) {
1138 session->se_cb_seq_nr = 1;
1139 goto retry_nowait;
1140 }
1141 break;
1142 default:
1143 nfsd4_mark_cb_fault(cb->cb_clp, cb->cb_seq_status);
1144 dprintk("%s: unprocessed error %d\n", __func__,
1145 cb->cb_seq_status);
1146 }
1147
1148 nfsd41_cb_release_slot(cb);
1149 dprintk("%s: freed slot, new seqid=%d\n", __func__,
1150 clp->cl_cb_session->se_cb_seq_nr);
1151
1152 if (RPC_SIGNALLED(task))
1153 goto need_restart;
1154out:
1155 return ret;
1156retry_nowait:
1157 if (rpc_restart_call_prepare(task))
1158 ret = false;
1159 goto out;
1160need_restart:
1161 if (!test_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags)) {
1162 task->tk_status = 0;
1163 cb->cb_need_restart = true;
1164 }
1165 return false;
1166}
1167
1168static void nfsd4_cb_done(struct rpc_task *task, void *calldata)
1169{
1170 struct nfsd4_callback *cb = calldata;
1171 struct nfs4_client *clp = cb->cb_clp;
1172
1173 trace_nfsd_cb_done(clp, task->tk_status);
1174
1175 if (!nfsd4_cb_sequence_done(task, cb))
1176 return;
1177
1178 if (cb->cb_status) {
1179 WARN_ON_ONCE(task->tk_status);
1180 task->tk_status = cb->cb_status;
1181 }
1182
1183 switch (cb->cb_ops->done(cb, task)) {
1184 case 0:
1185 task->tk_status = 0;
1186 rpc_restart_call_prepare(task);
1187 return;
1188 case 1:
1189 switch (task->tk_status) {
1190 case -EIO:
1191 case -ETIMEDOUT:
1192 nfsd4_mark_cb_down(clp, task->tk_status);
1193 }
1194 break;
1195 default:
1196 BUG();
1197 }
1198}
1199
1200static void nfsd4_cb_release(void *calldata)
1201{
1202 struct nfsd4_callback *cb = calldata;
1203
1204 if (cb->cb_need_restart)
1205 nfsd4_queue_cb(cb);
1206 else
1207 nfsd41_destroy_cb(cb);
1208
1209}
1210
1211static const struct rpc_call_ops nfsd4_cb_ops = {
1212 .rpc_call_prepare = nfsd4_cb_prepare,
1213 .rpc_call_done = nfsd4_cb_done,
1214 .rpc_release = nfsd4_cb_release,
1215};
1216
1217int nfsd4_create_callback_queue(void)
1218{
1219 callback_wq = alloc_ordered_workqueue("nfsd4_callbacks", 0);
1220 if (!callback_wq)
1221 return -ENOMEM;
1222 return 0;
1223}
1224
1225void nfsd4_destroy_callback_queue(void)
1226{
1227 destroy_workqueue(callback_wq);
1228}
1229
1230/* must be called under the state lock */
1231void nfsd4_shutdown_callback(struct nfs4_client *clp)
1232{
1233 set_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags);
1234 /*
1235 * Note this won't actually result in a null callback;
1236 * instead, nfsd4_run_cb_null() will detect the killed
1237 * client, destroy the rpc client, and stop:
1238 */
1239 nfsd4_run_cb(&clp->cl_cb_null);
1240 flush_workqueue(callback_wq);
1241 nfsd41_cb_inflight_wait_complete(clp);
1242}
1243
1244/* requires cl_lock: */
1245static struct nfsd4_conn * __nfsd4_find_backchannel(struct nfs4_client *clp)
1246{
1247 struct nfsd4_session *s;
1248 struct nfsd4_conn *c;
1249
1250 list_for_each_entry(s, &clp->cl_sessions, se_perclnt) {
1251 list_for_each_entry(c, &s->se_conns, cn_persession) {
1252 if (c->cn_flags & NFS4_CDFC4_BACK)
1253 return c;
1254 }
1255 }
1256 return NULL;
1257}
1258
1259/*
1260 * Note there isn't a lot of locking in this code; instead we depend on
1261 * the fact that it is run from the callback_wq, which won't run two
1262 * work items at once. So, for example, callback_wq handles all access
1263 * of cl_cb_client and all calls to rpc_create or rpc_shutdown_client.
1264 */
1265static void nfsd4_process_cb_update(struct nfsd4_callback *cb)
1266{
1267 struct nfs4_cb_conn conn;
1268 struct nfs4_client *clp = cb->cb_clp;
1269 struct nfsd4_session *ses = NULL;
1270 struct nfsd4_conn *c;
1271 int err;
1272
1273 /*
1274 * This is either an update, or the client dying; in either case,
1275 * kill the old client:
1276 */
1277 if (clp->cl_cb_client) {
1278 trace_nfsd_cb_shutdown(clp);
1279 rpc_shutdown_client(clp->cl_cb_client);
1280 clp->cl_cb_client = NULL;
1281 put_cred(clp->cl_cb_cred);
1282 clp->cl_cb_cred = NULL;
1283 }
1284 if (clp->cl_cb_conn.cb_xprt) {
1285 svc_xprt_put(clp->cl_cb_conn.cb_xprt);
1286 clp->cl_cb_conn.cb_xprt = NULL;
1287 }
1288 if (test_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags))
1289 return;
1290 spin_lock(&clp->cl_lock);
1291 /*
1292 * Only serialized callback code is allowed to clear these
1293 * flags; main nfsd code can only set them:
1294 */
1295 BUG_ON(!(clp->cl_flags & NFSD4_CLIENT_CB_FLAG_MASK));
1296 clear_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags);
1297 memcpy(&conn, &cb->cb_clp->cl_cb_conn, sizeof(struct nfs4_cb_conn));
1298 c = __nfsd4_find_backchannel(clp);
1299 if (c) {
1300 svc_xprt_get(c->cn_xprt);
1301 conn.cb_xprt = c->cn_xprt;
1302 ses = c->cn_session;
1303 }
1304 spin_unlock(&clp->cl_lock);
1305
1306 err = setup_callback_client(clp, &conn, ses);
1307 if (err) {
1308 nfsd4_mark_cb_down(clp, err);
1309 if (c)
1310 svc_xprt_put(c->cn_xprt);
1311 return;
1312 }
1313}
1314
1315static void
1316nfsd4_run_cb_work(struct work_struct *work)
1317{
1318 struct nfsd4_callback *cb =
1319 container_of(work, struct nfsd4_callback, cb_work);
1320 struct nfs4_client *clp = cb->cb_clp;
1321 struct rpc_clnt *clnt;
1322 int flags;
1323
1324 trace_nfsd_cb_work(clp, cb->cb_msg.rpc_proc->p_name);
1325
1326 if (cb->cb_need_restart) {
1327 cb->cb_need_restart = false;
1328 } else {
1329 if (cb->cb_ops && cb->cb_ops->prepare)
1330 cb->cb_ops->prepare(cb);
1331 }
1332
1333 if (clp->cl_flags & NFSD4_CLIENT_CB_FLAG_MASK)
1334 nfsd4_process_cb_update(cb);
1335
1336 clnt = clp->cl_cb_client;
1337 if (!clnt) {
1338 /* Callback channel broken, or client killed; give up: */
1339 nfsd41_destroy_cb(cb);
1340 return;
1341 }
1342
1343 /*
1344 * Don't send probe messages for 4.1 or later.
1345 */
1346 if (!cb->cb_ops && clp->cl_minorversion) {
1347 clp->cl_cb_state = NFSD4_CB_UP;
1348 nfsd41_destroy_cb(cb);
1349 return;
1350 }
1351
1352 cb->cb_msg.rpc_cred = clp->cl_cb_cred;
1353 flags = clp->cl_minorversion ? RPC_TASK_NOCONNECT : RPC_TASK_SOFTCONN;
1354 rpc_call_async(clnt, &cb->cb_msg, RPC_TASK_SOFT | flags,
1355 cb->cb_ops ? &nfsd4_cb_ops : &nfsd4_cb_probe_ops, cb);
1356}
1357
1358void nfsd4_init_cb(struct nfsd4_callback *cb, struct nfs4_client *clp,
1359 const struct nfsd4_callback_ops *ops, enum nfsd4_cb_op op)
1360{
1361 cb->cb_clp = clp;
1362 cb->cb_msg.rpc_proc = &nfs4_cb_procedures[op];
1363 cb->cb_msg.rpc_argp = cb;
1364 cb->cb_msg.rpc_resp = cb;
1365 cb->cb_ops = ops;
1366 INIT_WORK(&cb->cb_work, nfsd4_run_cb_work);
1367 cb->cb_seq_status = 1;
1368 cb->cb_status = 0;
1369 cb->cb_need_restart = false;
1370 cb->cb_holds_slot = false;
1371}
1372
1373void nfsd4_run_cb(struct nfsd4_callback *cb)
1374{
1375 struct nfs4_client *clp = cb->cb_clp;
1376
1377 nfsd41_cb_inflight_begin(clp);
1378 if (!nfsd4_queue_cb(cb))
1379 nfsd41_cb_inflight_end(clp);
1380}