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 xdr_stream_encode_uint32_array(xdr, array: bitmap, array_size: len);
88}
89
90static int decode_cb_fattr4(struct xdr_stream *xdr, uint32_t *bitmap,
91 struct nfs4_cb_fattr *fattr)
92{
93 fattr->ncf_cb_change = 0;
94 fattr->ncf_cb_fsize = 0;
95 if (bitmap[0] & FATTR4_WORD0_CHANGE)
96 if (xdr_stream_decode_u64(xdr, ptr: &fattr->ncf_cb_change) < 0)
97 return -NFSERR_BAD_XDR;
98 if (bitmap[0] & FATTR4_WORD0_SIZE)
99 if (xdr_stream_decode_u64(xdr, ptr: &fattr->ncf_cb_fsize) < 0)
100 return -NFSERR_BAD_XDR;
101 return 0;
102}
103
104/*
105 * nfs_cb_opnum4
106 *
107 * enum nfs_cb_opnum4 {
108 * OP_CB_GETATTR = 3,
109 * ...
110 * };
111 */
112enum nfs_cb_opnum4 {
113 OP_CB_GETATTR = 3,
114 OP_CB_RECALL = 4,
115 OP_CB_LAYOUTRECALL = 5,
116 OP_CB_NOTIFY = 6,
117 OP_CB_PUSH_DELEG = 7,
118 OP_CB_RECALL_ANY = 8,
119 OP_CB_RECALLABLE_OBJ_AVAIL = 9,
120 OP_CB_RECALL_SLOT = 10,
121 OP_CB_SEQUENCE = 11,
122 OP_CB_WANTS_CANCELLED = 12,
123 OP_CB_NOTIFY_LOCK = 13,
124 OP_CB_NOTIFY_DEVICEID = 14,
125 OP_CB_OFFLOAD = 15,
126 OP_CB_ILLEGAL = 10044
127};
128
129static void encode_nfs_cb_opnum4(struct xdr_stream *xdr, enum nfs_cb_opnum4 op)
130{
131 __be32 *p;
132
133 p = xdr_reserve_space(xdr, nbytes: 4);
134 *p = cpu_to_be32(op);
135}
136
137/*
138 * nfs_fh4
139 *
140 * typedef opaque nfs_fh4<NFS4_FHSIZE>;
141 */
142static void encode_nfs_fh4(struct xdr_stream *xdr, const struct knfsd_fh *fh)
143{
144 u32 length = fh->fh_size;
145 __be32 *p;
146
147 BUG_ON(length > NFS4_FHSIZE);
148 p = xdr_reserve_space(xdr, nbytes: 4 + length);
149 xdr_encode_opaque(p, ptr: &fh->fh_raw, len: length);
150}
151
152/*
153 * stateid4
154 *
155 * struct stateid4 {
156 * uint32_t seqid;
157 * opaque other[12];
158 * };
159 */
160static void encode_stateid4(struct xdr_stream *xdr, const stateid_t *sid)
161{
162 __be32 *p;
163
164 p = xdr_reserve_space(xdr, NFS4_STATEID_SIZE);
165 *p++ = cpu_to_be32(sid->si_generation);
166 xdr_encode_opaque_fixed(p, ptr: &sid->si_opaque, NFS4_STATEID_OTHER_SIZE);
167}
168
169/*
170 * sessionid4
171 *
172 * typedef opaque sessionid4[NFS4_SESSIONID_SIZE];
173 */
174static void encode_sessionid4(struct xdr_stream *xdr,
175 const struct nfsd4_session *session)
176{
177 __be32 *p;
178
179 p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN);
180 xdr_encode_opaque_fixed(p, ptr: session->se_sessionid.data,
181 NFS4_MAX_SESSIONID_LEN);
182}
183
184/*
185 * nfsstat4
186 */
187static const struct {
188 int stat;
189 int errno;
190} nfs_cb_errtbl[] = {
191 { NFS4_OK, 0 },
192 { NFS4ERR_PERM, -EPERM },
193 { NFS4ERR_NOENT, -ENOENT },
194 { NFS4ERR_IO, -EIO },
195 { NFS4ERR_NXIO, -ENXIO },
196 { NFS4ERR_ACCESS, -EACCES },
197 { NFS4ERR_EXIST, -EEXIST },
198 { NFS4ERR_XDEV, -EXDEV },
199 { NFS4ERR_NOTDIR, -ENOTDIR },
200 { NFS4ERR_ISDIR, -EISDIR },
201 { NFS4ERR_INVAL, -EINVAL },
202 { NFS4ERR_FBIG, -EFBIG },
203 { NFS4ERR_NOSPC, -ENOSPC },
204 { NFS4ERR_ROFS, -EROFS },
205 { NFS4ERR_MLINK, -EMLINK },
206 { NFS4ERR_NAMETOOLONG, -ENAMETOOLONG },
207 { NFS4ERR_NOTEMPTY, -ENOTEMPTY },
208 { NFS4ERR_DQUOT, -EDQUOT },
209 { NFS4ERR_STALE, -ESTALE },
210 { NFS4ERR_BADHANDLE, -EBADHANDLE },
211 { NFS4ERR_BAD_COOKIE, -EBADCOOKIE },
212 { NFS4ERR_NOTSUPP, -ENOTSUPP },
213 { NFS4ERR_TOOSMALL, -ETOOSMALL },
214 { NFS4ERR_SERVERFAULT, -ESERVERFAULT },
215 { NFS4ERR_BADTYPE, -EBADTYPE },
216 { NFS4ERR_LOCKED, -EAGAIN },
217 { NFS4ERR_RESOURCE, -EREMOTEIO },
218 { NFS4ERR_SYMLINK, -ELOOP },
219 { NFS4ERR_OP_ILLEGAL, -EOPNOTSUPP },
220 { NFS4ERR_DEADLOCK, -EDEADLK },
221 { -1, -EIO }
222};
223
224/*
225 * If we cannot translate the error, the recovery routines should
226 * handle it.
227 *
228 * Note: remaining NFSv4 error codes have values > 10000, so should
229 * not conflict with native Linux error codes.
230 */
231static int nfs_cb_stat_to_errno(int status)
232{
233 int i;
234
235 for (i = 0; nfs_cb_errtbl[i].stat != -1; i++) {
236 if (nfs_cb_errtbl[i].stat == status)
237 return nfs_cb_errtbl[i].errno;
238 }
239
240 dprintk("NFSD: Unrecognized NFS CB status value: %u\n", status);
241 return -status;
242}
243
244static int decode_cb_op_status(struct xdr_stream *xdr,
245 enum nfs_cb_opnum4 expected, int *status)
246{
247 __be32 *p;
248 u32 op;
249
250 p = xdr_inline_decode(xdr, nbytes: 4 + 4);
251 if (unlikely(p == NULL))
252 goto out_overflow;
253 op = be32_to_cpup(p: p++);
254 if (unlikely(op != expected))
255 goto out_unexpected;
256 *status = nfs_cb_stat_to_errno(be32_to_cpup(p));
257 return 0;
258out_overflow:
259 return -EIO;
260out_unexpected:
261 dprintk("NFSD: Callback server returned operation %d but "
262 "we issued a request for %d\n", op, expected);
263 return -EIO;
264}
265
266/*
267 * CB_COMPOUND4args
268 *
269 * struct CB_COMPOUND4args {
270 * utf8str_cs tag;
271 * uint32_t minorversion;
272 * uint32_t callback_ident;
273 * nfs_cb_argop4 argarray<>;
274 * };
275*/
276static void encode_cb_compound4args(struct xdr_stream *xdr,
277 struct nfs4_cb_compound_hdr *hdr)
278{
279 __be32 * p;
280
281 p = xdr_reserve_space(xdr, nbytes: 4 + 4 + 4 + 4);
282 p = xdr_encode_empty_array(p); /* empty tag */
283 *p++ = cpu_to_be32(hdr->minorversion);
284 *p++ = cpu_to_be32(hdr->ident);
285
286 hdr->nops_p = p;
287 *p = cpu_to_be32(hdr->nops); /* argarray element count */
288}
289
290/*
291 * Update argarray element count
292 */
293static void encode_cb_nops(struct nfs4_cb_compound_hdr *hdr)
294{
295 BUG_ON(hdr->nops > NFS4_MAX_BACK_CHANNEL_OPS);
296 *hdr->nops_p = cpu_to_be32(hdr->nops);
297}
298
299/*
300 * CB_COMPOUND4res
301 *
302 * struct CB_COMPOUND4res {
303 * nfsstat4 status;
304 * utf8str_cs tag;
305 * nfs_cb_resop4 resarray<>;
306 * };
307 */
308static int decode_cb_compound4res(struct xdr_stream *xdr,
309 struct nfs4_cb_compound_hdr *hdr)
310{
311 u32 length;
312 __be32 *p;
313
314 p = xdr_inline_decode(xdr, nbytes: 4 + 4);
315 if (unlikely(p == NULL))
316 goto out_overflow;
317 hdr->status = be32_to_cpup(p: p++);
318 /* Ignore the tag */
319 length = be32_to_cpup(p: p++);
320 p = xdr_inline_decode(xdr, nbytes: length + 4);
321 if (unlikely(p == NULL))
322 goto out_overflow;
323 p += XDR_QUADLEN(length);
324 hdr->nops = be32_to_cpup(p);
325 return 0;
326out_overflow:
327 return -EIO;
328}
329
330/*
331 * CB_RECALL4args
332 *
333 * struct CB_RECALL4args {
334 * stateid4 stateid;
335 * bool truncate;
336 * nfs_fh4 fh;
337 * };
338 */
339static void encode_cb_recall4args(struct xdr_stream *xdr,
340 const struct nfs4_delegation *dp,
341 struct nfs4_cb_compound_hdr *hdr)
342{
343 __be32 *p;
344
345 encode_nfs_cb_opnum4(xdr, op: OP_CB_RECALL);
346 encode_stateid4(xdr, sid: &dp->dl_stid.sc_stateid);
347
348 p = xdr_reserve_space(xdr, nbytes: 4);
349 *p++ = xdr_zero; /* truncate */
350
351 encode_nfs_fh4(xdr, fh: &dp->dl_stid.sc_file->fi_fhandle);
352
353 hdr->nops++;
354}
355
356/*
357 * CB_RECALLANY4args
358 *
359 * struct CB_RECALLANY4args {
360 * uint32_t craa_objects_to_keep;
361 * bitmap4 craa_type_mask;
362 * };
363 */
364static void
365encode_cb_recallany4args(struct xdr_stream *xdr,
366 struct nfs4_cb_compound_hdr *hdr, struct nfsd4_cb_recall_any *ra)
367{
368 encode_nfs_cb_opnum4(xdr, op: OP_CB_RECALL_ANY);
369 encode_uint32(xdr, n: ra->ra_keep);
370 encode_bitmap4(xdr, bitmap: ra->ra_bmval, ARRAY_SIZE(ra->ra_bmval));
371 hdr->nops++;
372}
373
374/*
375 * CB_GETATTR4args
376 * struct CB_GETATTR4args {
377 * nfs_fh4 fh;
378 * bitmap4 attr_request;
379 * };
380 *
381 * The size and change attributes are the only one
382 * guaranteed to be serviced by the client.
383 */
384static void
385encode_cb_getattr4args(struct xdr_stream *xdr, struct nfs4_cb_compound_hdr *hdr,
386 struct nfs4_cb_fattr *fattr)
387{
388 struct nfs4_delegation *dp =
389 container_of(fattr, struct nfs4_delegation, dl_cb_fattr);
390 struct knfsd_fh *fh = &dp->dl_stid.sc_file->fi_fhandle;
391
392 encode_nfs_cb_opnum4(xdr, op: OP_CB_GETATTR);
393 encode_nfs_fh4(xdr, fh);
394 encode_bitmap4(xdr, bitmap: fattr->ncf_cb_bmap, ARRAY_SIZE(fattr->ncf_cb_bmap));
395 hdr->nops++;
396}
397
398/*
399 * CB_SEQUENCE4args
400 *
401 * struct CB_SEQUENCE4args {
402 * sessionid4 csa_sessionid;
403 * sequenceid4 csa_sequenceid;
404 * slotid4 csa_slotid;
405 * slotid4 csa_highest_slotid;
406 * bool csa_cachethis;
407 * referring_call_list4 csa_referring_call_lists<>;
408 * };
409 */
410static void encode_cb_sequence4args(struct xdr_stream *xdr,
411 const struct nfsd4_callback *cb,
412 struct nfs4_cb_compound_hdr *hdr)
413{
414 struct nfsd4_session *session = cb->cb_clp->cl_cb_session;
415 __be32 *p;
416
417 if (hdr->minorversion == 0)
418 return;
419
420 encode_nfs_cb_opnum4(xdr, op: OP_CB_SEQUENCE);
421 encode_sessionid4(xdr, session);
422
423 p = xdr_reserve_space(xdr, nbytes: 4 + 4 + 4 + 4 + 4);
424 *p++ = cpu_to_be32(session->se_cb_seq_nr); /* csa_sequenceid */
425 *p++ = xdr_zero; /* csa_slotid */
426 *p++ = xdr_zero; /* csa_highest_slotid */
427 *p++ = xdr_zero; /* csa_cachethis */
428 xdr_encode_empty_array(p); /* csa_referring_call_lists */
429
430 hdr->nops++;
431}
432
433/*
434 * CB_SEQUENCE4resok
435 *
436 * struct CB_SEQUENCE4resok {
437 * sessionid4 csr_sessionid;
438 * sequenceid4 csr_sequenceid;
439 * slotid4 csr_slotid;
440 * slotid4 csr_highest_slotid;
441 * slotid4 csr_target_highest_slotid;
442 * };
443 *
444 * union CB_SEQUENCE4res switch (nfsstat4 csr_status) {
445 * case NFS4_OK:
446 * CB_SEQUENCE4resok csr_resok4;
447 * default:
448 * void;
449 * };
450 *
451 * Our current back channel implmentation supports a single backchannel
452 * with a single slot.
453 */
454static int decode_cb_sequence4resok(struct xdr_stream *xdr,
455 struct nfsd4_callback *cb)
456{
457 struct nfsd4_session *session = cb->cb_clp->cl_cb_session;
458 int status = -ESERVERFAULT;
459 __be32 *p;
460 u32 dummy;
461
462 /*
463 * If the server returns different values for sessionID, slotID or
464 * sequence number, the server is looney tunes.
465 */
466 p = xdr_inline_decode(xdr, NFS4_MAX_SESSIONID_LEN + 4 + 4 + 4 + 4);
467 if (unlikely(p == NULL))
468 goto out_overflow;
469
470 if (memcmp(p, q: session->se_sessionid.data, NFS4_MAX_SESSIONID_LEN)) {
471 dprintk("NFS: %s Invalid session id\n", __func__);
472 goto out;
473 }
474 p += XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN);
475
476 dummy = be32_to_cpup(p: p++);
477 if (dummy != session->se_cb_seq_nr) {
478 dprintk("NFS: %s Invalid sequence number\n", __func__);
479 goto out;
480 }
481
482 dummy = be32_to_cpup(p: p++);
483 if (dummy != 0) {
484 dprintk("NFS: %s Invalid slotid\n", __func__);
485 goto out;
486 }
487
488 /*
489 * FIXME: process highest slotid and target highest slotid
490 */
491 status = 0;
492out:
493 cb->cb_seq_status = status;
494 return status;
495out_overflow:
496 status = -EIO;
497 goto out;
498}
499
500static int decode_cb_sequence4res(struct xdr_stream *xdr,
501 struct nfsd4_callback *cb)
502{
503 int status;
504
505 if (cb->cb_clp->cl_minorversion == 0)
506 return 0;
507
508 status = decode_cb_op_status(xdr, expected: OP_CB_SEQUENCE, status: &cb->cb_seq_status);
509 if (unlikely(status || cb->cb_seq_status))
510 return status;
511
512 return decode_cb_sequence4resok(xdr, cb);
513}
514
515/*
516 * NFSv4.0 and NFSv4.1 XDR encode functions
517 *
518 * NFSv4.0 callback argument types are defined in section 15 of RFC
519 * 3530: "Network File System (NFS) version 4 Protocol" and section 20
520 * of RFC 5661: "Network File System (NFS) Version 4 Minor Version 1
521 * Protocol".
522 */
523
524/*
525 * NB: Without this zero space reservation, callbacks over krb5p fail
526 */
527static void nfs4_xdr_enc_cb_null(struct rpc_rqst *req, struct xdr_stream *xdr,
528 const void *__unused)
529{
530 xdr_reserve_space(xdr, nbytes: 0);
531}
532
533/*
534 * 20.1. Operation 3: CB_GETATTR - Get Attributes
535 */
536static void nfs4_xdr_enc_cb_getattr(struct rpc_rqst *req,
537 struct xdr_stream *xdr, const void *data)
538{
539 const struct nfsd4_callback *cb = data;
540 struct nfs4_cb_fattr *ncf =
541 container_of(cb, struct nfs4_cb_fattr, ncf_getattr);
542 struct nfs4_cb_compound_hdr hdr = {
543 .ident = cb->cb_clp->cl_cb_ident,
544 .minorversion = cb->cb_clp->cl_minorversion,
545 };
546
547 encode_cb_compound4args(xdr, hdr: &hdr);
548 encode_cb_sequence4args(xdr, cb, hdr: &hdr);
549 encode_cb_getattr4args(xdr, hdr: &hdr, fattr: ncf);
550 encode_cb_nops(hdr: &hdr);
551}
552
553/*
554 * 20.2. Operation 4: CB_RECALL - Recall a Delegation
555 */
556static void nfs4_xdr_enc_cb_recall(struct rpc_rqst *req, struct xdr_stream *xdr,
557 const void *data)
558{
559 const struct nfsd4_callback *cb = data;
560 const struct nfs4_delegation *dp = cb_to_delegation(cb);
561 struct nfs4_cb_compound_hdr hdr = {
562 .ident = cb->cb_clp->cl_cb_ident,
563 .minorversion = cb->cb_clp->cl_minorversion,
564 };
565
566 encode_cb_compound4args(xdr, hdr: &hdr);
567 encode_cb_sequence4args(xdr, cb, hdr: &hdr);
568 encode_cb_recall4args(xdr, dp, hdr: &hdr);
569 encode_cb_nops(hdr: &hdr);
570}
571
572/*
573 * 20.6. Operation 8: CB_RECALL_ANY - Keep Any N Recallable Objects
574 */
575static void
576nfs4_xdr_enc_cb_recall_any(struct rpc_rqst *req,
577 struct xdr_stream *xdr, const void *data)
578{
579 const struct nfsd4_callback *cb = data;
580 struct nfsd4_cb_recall_any *ra;
581 struct nfs4_cb_compound_hdr hdr = {
582 .ident = cb->cb_clp->cl_cb_ident,
583 .minorversion = cb->cb_clp->cl_minorversion,
584 };
585
586 ra = container_of(cb, struct nfsd4_cb_recall_any, ra_cb);
587 encode_cb_compound4args(xdr, hdr: &hdr);
588 encode_cb_sequence4args(xdr, cb, hdr: &hdr);
589 encode_cb_recallany4args(xdr, hdr: &hdr, ra);
590 encode_cb_nops(hdr: &hdr);
591}
592
593/*
594 * NFSv4.0 and NFSv4.1 XDR decode functions
595 *
596 * NFSv4.0 callback result types are defined in section 15 of RFC
597 * 3530: "Network File System (NFS) version 4 Protocol" and section 20
598 * of RFC 5661: "Network File System (NFS) Version 4 Minor Version 1
599 * Protocol".
600 */
601
602static int nfs4_xdr_dec_cb_null(struct rpc_rqst *req, struct xdr_stream *xdr,
603 void *__unused)
604{
605 return 0;
606}
607
608/*
609 * 20.1. Operation 3: CB_GETATTR - Get Attributes
610 */
611static int nfs4_xdr_dec_cb_getattr(struct rpc_rqst *rqstp,
612 struct xdr_stream *xdr,
613 void *data)
614{
615 struct nfsd4_callback *cb = data;
616 struct nfs4_cb_compound_hdr hdr;
617 int status;
618 u32 bitmap[3] = {0};
619 u32 attrlen;
620 struct nfs4_cb_fattr *ncf =
621 container_of(cb, struct nfs4_cb_fattr, ncf_getattr);
622
623 status = decode_cb_compound4res(xdr, hdr: &hdr);
624 if (unlikely(status))
625 return status;
626
627 status = decode_cb_sequence4res(xdr, cb);
628 if (unlikely(status || cb->cb_seq_status))
629 return status;
630
631 status = decode_cb_op_status(xdr, expected: OP_CB_GETATTR, status: &cb->cb_status);
632 if (status)
633 return status;
634 if (xdr_stream_decode_uint32_array(xdr, array: bitmap, array_size: 3) < 0)
635 return -NFSERR_BAD_XDR;
636 if (xdr_stream_decode_u32(xdr, ptr: &attrlen) < 0)
637 return -NFSERR_BAD_XDR;
638 if (attrlen > (sizeof(ncf->ncf_cb_change) + sizeof(ncf->ncf_cb_fsize)))
639 return -NFSERR_BAD_XDR;
640 status = decode_cb_fattr4(xdr, bitmap, fattr: ncf);
641 return status;
642}
643
644/*
645 * 20.2. Operation 4: CB_RECALL - Recall a Delegation
646 */
647static int nfs4_xdr_dec_cb_recall(struct rpc_rqst *rqstp,
648 struct xdr_stream *xdr,
649 void *data)
650{
651 struct nfsd4_callback *cb = data;
652 struct nfs4_cb_compound_hdr hdr;
653 int status;
654
655 status = decode_cb_compound4res(xdr, hdr: &hdr);
656 if (unlikely(status))
657 return status;
658
659 status = decode_cb_sequence4res(xdr, cb);
660 if (unlikely(status || cb->cb_seq_status))
661 return status;
662
663 return decode_cb_op_status(xdr, expected: OP_CB_RECALL, status: &cb->cb_status);
664}
665
666/*
667 * 20.6. Operation 8: CB_RECALL_ANY - Keep Any N Recallable Objects
668 */
669static int
670nfs4_xdr_dec_cb_recall_any(struct rpc_rqst *rqstp,
671 struct xdr_stream *xdr,
672 void *data)
673{
674 struct nfsd4_callback *cb = data;
675 struct nfs4_cb_compound_hdr hdr;
676 int status;
677
678 status = decode_cb_compound4res(xdr, hdr: &hdr);
679 if (unlikely(status))
680 return status;
681 status = decode_cb_sequence4res(xdr, cb);
682 if (unlikely(status || cb->cb_seq_status))
683 return status;
684 status = decode_cb_op_status(xdr, expected: OP_CB_RECALL_ANY, status: &cb->cb_status);
685 return status;
686}
687
688#ifdef CONFIG_NFSD_PNFS
689/*
690 * CB_LAYOUTRECALL4args
691 *
692 * struct layoutrecall_file4 {
693 * nfs_fh4 lor_fh;
694 * offset4 lor_offset;
695 * length4 lor_length;
696 * stateid4 lor_stateid;
697 * };
698 *
699 * union layoutrecall4 switch(layoutrecall_type4 lor_recalltype) {
700 * case LAYOUTRECALL4_FILE:
701 * layoutrecall_file4 lor_layout;
702 * case LAYOUTRECALL4_FSID:
703 * fsid4 lor_fsid;
704 * case LAYOUTRECALL4_ALL:
705 * void;
706 * };
707 *
708 * struct CB_LAYOUTRECALL4args {
709 * layouttype4 clora_type;
710 * layoutiomode4 clora_iomode;
711 * bool clora_changed;
712 * layoutrecall4 clora_recall;
713 * };
714 */
715static void encode_cb_layout4args(struct xdr_stream *xdr,
716 const struct nfs4_layout_stateid *ls,
717 struct nfs4_cb_compound_hdr *hdr)
718{
719 __be32 *p;
720
721 BUG_ON(hdr->minorversion == 0);
722
723 p = xdr_reserve_space(xdr, nbytes: 5 * 4);
724 *p++ = cpu_to_be32(OP_CB_LAYOUTRECALL);
725 *p++ = cpu_to_be32(ls->ls_layout_type);
726 *p++ = cpu_to_be32(IOMODE_ANY);
727 *p++ = cpu_to_be32(1);
728 *p = cpu_to_be32(RETURN_FILE);
729
730 encode_nfs_fh4(xdr, fh: &ls->ls_stid.sc_file->fi_fhandle);
731
732 p = xdr_reserve_space(xdr, nbytes: 2 * 8);
733 p = xdr_encode_hyper(p, val: 0);
734 xdr_encode_hyper(p, NFS4_MAX_UINT64);
735
736 encode_stateid4(xdr, sid: &ls->ls_recall_sid);
737
738 hdr->nops++;
739}
740
741static void nfs4_xdr_enc_cb_layout(struct rpc_rqst *req,
742 struct xdr_stream *xdr,
743 const void *data)
744{
745 const struct nfsd4_callback *cb = data;
746 const struct nfs4_layout_stateid *ls =
747 container_of(cb, struct nfs4_layout_stateid, ls_recall);
748 struct nfs4_cb_compound_hdr hdr = {
749 .ident = 0,
750 .minorversion = cb->cb_clp->cl_minorversion,
751 };
752
753 encode_cb_compound4args(xdr, hdr: &hdr);
754 encode_cb_sequence4args(xdr, cb, hdr: &hdr);
755 encode_cb_layout4args(xdr, ls, hdr: &hdr);
756 encode_cb_nops(hdr: &hdr);
757}
758
759static int nfs4_xdr_dec_cb_layout(struct rpc_rqst *rqstp,
760 struct xdr_stream *xdr,
761 void *data)
762{
763 struct nfsd4_callback *cb = data;
764 struct nfs4_cb_compound_hdr hdr;
765 int status;
766
767 status = decode_cb_compound4res(xdr, hdr: &hdr);
768 if (unlikely(status))
769 return status;
770
771 status = decode_cb_sequence4res(xdr, cb);
772 if (unlikely(status || cb->cb_seq_status))
773 return status;
774
775 return decode_cb_op_status(xdr, expected: OP_CB_LAYOUTRECALL, status: &cb->cb_status);
776}
777#endif /* CONFIG_NFSD_PNFS */
778
779static void encode_stateowner(struct xdr_stream *xdr, struct nfs4_stateowner *so)
780{
781 __be32 *p;
782
783 p = xdr_reserve_space(xdr, nbytes: 8 + 4 + so->so_owner.len);
784 p = xdr_encode_opaque_fixed(p, ptr: &so->so_client->cl_clientid, len: 8);
785 xdr_encode_opaque(p, ptr: so->so_owner.data, len: so->so_owner.len);
786}
787
788static void nfs4_xdr_enc_cb_notify_lock(struct rpc_rqst *req,
789 struct xdr_stream *xdr,
790 const void *data)
791{
792 const struct nfsd4_callback *cb = data;
793 const struct nfsd4_blocked_lock *nbl =
794 container_of(cb, struct nfsd4_blocked_lock, nbl_cb);
795 struct nfs4_lockowner *lo = (struct nfs4_lockowner *)nbl->nbl_lock.fl_owner;
796 struct nfs4_cb_compound_hdr hdr = {
797 .ident = 0,
798 .minorversion = cb->cb_clp->cl_minorversion,
799 };
800
801 __be32 *p;
802
803 BUG_ON(hdr.minorversion == 0);
804
805 encode_cb_compound4args(xdr, hdr: &hdr);
806 encode_cb_sequence4args(xdr, cb, hdr: &hdr);
807
808 p = xdr_reserve_space(xdr, nbytes: 4);
809 *p = cpu_to_be32(OP_CB_NOTIFY_LOCK);
810 encode_nfs_fh4(xdr, fh: &nbl->nbl_fh);
811 encode_stateowner(xdr, so: &lo->lo_owner);
812 hdr.nops++;
813
814 encode_cb_nops(hdr: &hdr);
815}
816
817static int nfs4_xdr_dec_cb_notify_lock(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: &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, expected: OP_CB_NOTIFY_LOCK, status: &cb->cb_status);
834}
835
836/*
837 * struct write_response4 {
838 * stateid4 wr_callback_id<1>;
839 * length4 wr_count;
840 * stable_how4 wr_committed;
841 * verifier4 wr_writeverf;
842 * };
843 * union offload_info4 switch (nfsstat4 coa_status) {
844 * case NFS4_OK:
845 * write_response4 coa_resok4;
846 * default:
847 * length4 coa_bytes_copied;
848 * };
849 * struct CB_OFFLOAD4args {
850 * nfs_fh4 coa_fh;
851 * stateid4 coa_stateid;
852 * offload_info4 coa_offload_info;
853 * };
854 */
855static void encode_offload_info4(struct xdr_stream *xdr,
856 const struct nfsd4_cb_offload *cbo)
857{
858 __be32 *p;
859
860 p = xdr_reserve_space(xdr, nbytes: 4);
861 *p = cbo->co_nfserr;
862 switch (cbo->co_nfserr) {
863 case nfs_ok:
864 p = xdr_reserve_space(xdr, nbytes: 4 + 8 + 4 + NFS4_VERIFIER_SIZE);
865 p = xdr_encode_empty_array(p);
866 p = xdr_encode_hyper(p, val: cbo->co_res.wr_bytes_written);
867 *p++ = cpu_to_be32(cbo->co_res.wr_stable_how);
868 p = xdr_encode_opaque_fixed(p, ptr: cbo->co_res.wr_verifier.data,
869 NFS4_VERIFIER_SIZE);
870 break;
871 default:
872 p = xdr_reserve_space(xdr, nbytes: 8);
873 /* We always return success if bytes were written */
874 p = xdr_encode_hyper(p, val: 0);
875 }
876}
877
878static void encode_cb_offload4args(struct xdr_stream *xdr,
879 const struct nfsd4_cb_offload *cbo,
880 struct nfs4_cb_compound_hdr *hdr)
881{
882 __be32 *p;
883
884 p = xdr_reserve_space(xdr, nbytes: 4);
885 *p = cpu_to_be32(OP_CB_OFFLOAD);
886 encode_nfs_fh4(xdr, fh: &cbo->co_fh);
887 encode_stateid4(xdr, sid: &cbo->co_res.cb_stateid);
888 encode_offload_info4(xdr, cbo);
889
890 hdr->nops++;
891}
892
893static void nfs4_xdr_enc_cb_offload(struct rpc_rqst *req,
894 struct xdr_stream *xdr,
895 const void *data)
896{
897 const struct nfsd4_callback *cb = data;
898 const struct nfsd4_cb_offload *cbo =
899 container_of(cb, struct nfsd4_cb_offload, co_cb);
900 struct nfs4_cb_compound_hdr hdr = {
901 .ident = 0,
902 .minorversion = cb->cb_clp->cl_minorversion,
903 };
904
905 encode_cb_compound4args(xdr, hdr: &hdr);
906 encode_cb_sequence4args(xdr, cb, hdr: &hdr);
907 encode_cb_offload4args(xdr, cbo, hdr: &hdr);
908 encode_cb_nops(hdr: &hdr);
909}
910
911static int nfs4_xdr_dec_cb_offload(struct rpc_rqst *rqstp,
912 struct xdr_stream *xdr,
913 void *data)
914{
915 struct nfsd4_callback *cb = data;
916 struct nfs4_cb_compound_hdr hdr;
917 int status;
918
919 status = decode_cb_compound4res(xdr, hdr: &hdr);
920 if (unlikely(status))
921 return status;
922
923 status = decode_cb_sequence4res(xdr, cb);
924 if (unlikely(status || cb->cb_seq_status))
925 return status;
926
927 return decode_cb_op_status(xdr, expected: OP_CB_OFFLOAD, status: &cb->cb_status);
928}
929/*
930 * RPC procedure tables
931 */
932#define PROC(proc, call, argtype, restype) \
933[NFSPROC4_CLNT_##proc] = { \
934 .p_proc = NFSPROC4_CB_##call, \
935 .p_encode = nfs4_xdr_enc_##argtype, \
936 .p_decode = nfs4_xdr_dec_##restype, \
937 .p_arglen = NFS4_enc_##argtype##_sz, \
938 .p_replen = NFS4_dec_##restype##_sz, \
939 .p_statidx = NFSPROC4_CB_##call, \
940 .p_name = #proc, \
941}
942
943static const struct rpc_procinfo nfs4_cb_procedures[] = {
944 PROC(CB_NULL, NULL, cb_null, cb_null),
945 PROC(CB_RECALL, COMPOUND, cb_recall, cb_recall),
946#ifdef CONFIG_NFSD_PNFS
947 PROC(CB_LAYOUT, COMPOUND, cb_layout, cb_layout),
948#endif
949 PROC(CB_NOTIFY_LOCK, COMPOUND, cb_notify_lock, cb_notify_lock),
950 PROC(CB_OFFLOAD, COMPOUND, cb_offload, cb_offload),
951 PROC(CB_RECALL_ANY, COMPOUND, cb_recall_any, cb_recall_any),
952 PROC(CB_GETATTR, COMPOUND, cb_getattr, cb_getattr),
953};
954
955static unsigned int nfs4_cb_counts[ARRAY_SIZE(nfs4_cb_procedures)];
956static const struct rpc_version nfs_cb_version4 = {
957/*
958 * Note on the callback rpc program version number: despite language in rfc
959 * 5661 section 18.36.3 requiring servers to use 4 in this field, the
960 * official xdr descriptions for both 4.0 and 4.1 specify version 1, and
961 * in practice that appears to be what implementations use. The section
962 * 18.36.3 language is expected to be fixed in an erratum.
963 */
964 .number = 1,
965 .nrprocs = ARRAY_SIZE(nfs4_cb_procedures),
966 .procs = nfs4_cb_procedures,
967 .counts = nfs4_cb_counts,
968};
969
970static const struct rpc_version *nfs_cb_version[2] = {
971 [1] = &nfs_cb_version4,
972};
973
974static const struct rpc_program cb_program;
975
976static struct rpc_stat cb_stats = {
977 .program = &cb_program
978};
979
980#define NFS4_CALLBACK 0x40000000
981static const struct rpc_program cb_program = {
982 .name = "nfs4_cb",
983 .number = NFS4_CALLBACK,
984 .nrvers = ARRAY_SIZE(nfs_cb_version),
985 .version = nfs_cb_version,
986 .stats = &cb_stats,
987 .pipe_dir_name = "nfsd4_cb",
988};
989
990static int max_cb_time(struct net *net)
991{
992 struct nfsd_net *nn = net_generic(net, id: nfsd_net_id);
993
994 /*
995 * nfsd4_lease is set to at most one hour in __nfsd4_write_time,
996 * so we can use 32-bit math on it. Warn if that assumption
997 * ever stops being true.
998 */
999 if (WARN_ON_ONCE(nn->nfsd4_lease > 3600))
1000 return 360 * HZ;
1001
1002 return max(((u32)nn->nfsd4_lease)/10, 1u) * HZ;
1003}
1004
1005static struct workqueue_struct *callback_wq;
1006
1007static bool nfsd4_queue_cb(struct nfsd4_callback *cb)
1008{
1009 return queue_work(wq: callback_wq, work: &cb->cb_work);
1010}
1011
1012static void nfsd41_cb_inflight_begin(struct nfs4_client *clp)
1013{
1014 atomic_inc(v: &clp->cl_cb_inflight);
1015}
1016
1017static void nfsd41_cb_inflight_end(struct nfs4_client *clp)
1018{
1019
1020 if (atomic_dec_and_test(v: &clp->cl_cb_inflight))
1021 wake_up_var(var: &clp->cl_cb_inflight);
1022}
1023
1024static void nfsd41_cb_inflight_wait_complete(struct nfs4_client *clp)
1025{
1026 wait_var_event(&clp->cl_cb_inflight,
1027 !atomic_read(&clp->cl_cb_inflight));
1028}
1029
1030static const struct cred *get_backchannel_cred(struct nfs4_client *clp, struct rpc_clnt *client, struct nfsd4_session *ses)
1031{
1032 if (clp->cl_minorversion == 0) {
1033 client->cl_principal = clp->cl_cred.cr_targ_princ ?
1034 clp->cl_cred.cr_targ_princ : "nfs";
1035
1036 return get_cred(cred: rpc_machine_cred());
1037 } else {
1038 struct cred *kcred;
1039
1040 kcred = prepare_kernel_cred(&init_task);
1041 if (!kcred)
1042 return NULL;
1043
1044 kcred->fsuid = ses->se_cb_sec.uid;
1045 kcred->fsgid = ses->se_cb_sec.gid;
1046 return kcred;
1047 }
1048}
1049
1050static int setup_callback_client(struct nfs4_client *clp, struct nfs4_cb_conn *conn, struct nfsd4_session *ses)
1051{
1052 int maxtime = max_cb_time(net: clp->net);
1053 struct rpc_timeout timeparms = {
1054 .to_initval = maxtime,
1055 .to_retries = 0,
1056 .to_maxval = maxtime,
1057 };
1058 struct rpc_create_args args = {
1059 .net = clp->net,
1060 .address = (struct sockaddr *) &conn->cb_addr,
1061 .addrsize = conn->cb_addrlen,
1062 .saddress = (struct sockaddr *) &conn->cb_saddr,
1063 .timeout = &timeparms,
1064 .program = &cb_program,
1065 .version = 1,
1066 .flags = (RPC_CLNT_CREATE_NOPING | RPC_CLNT_CREATE_QUIET),
1067 .cred = current_cred(),
1068 };
1069 struct rpc_clnt *client;
1070 const struct cred *cred;
1071
1072 if (clp->cl_minorversion == 0) {
1073 if (!clp->cl_cred.cr_principal &&
1074 (clp->cl_cred.cr_flavor >= RPC_AUTH_GSS_KRB5)) {
1075 trace_nfsd_cb_setup_err(clp, error: -EINVAL);
1076 return -EINVAL;
1077 }
1078 args.client_name = clp->cl_cred.cr_principal;
1079 args.prognumber = conn->cb_prog;
1080 args.protocol = XPRT_TRANSPORT_TCP;
1081 args.authflavor = clp->cl_cred.cr_flavor;
1082 clp->cl_cb_ident = conn->cb_ident;
1083 } else {
1084 if (!conn->cb_xprt)
1085 return -EINVAL;
1086 clp->cl_cb_session = ses;
1087 args.bc_xprt = conn->cb_xprt;
1088 args.prognumber = clp->cl_cb_session->se_cb_prog;
1089 args.protocol = conn->cb_xprt->xpt_class->xcl_ident |
1090 XPRT_TRANSPORT_BC;
1091 args.authflavor = ses->se_cb_sec.flavor;
1092 }
1093 /* Create RPC client */
1094 client = rpc_create(args: &args);
1095 if (IS_ERR(ptr: client)) {
1096 trace_nfsd_cb_setup_err(clp, error: PTR_ERR(ptr: client));
1097 return PTR_ERR(ptr: client);
1098 }
1099 cred = get_backchannel_cred(clp, client, ses);
1100 if (!cred) {
1101 trace_nfsd_cb_setup_err(clp, error: -ENOMEM);
1102 rpc_shutdown_client(client);
1103 return -ENOMEM;
1104 }
1105
1106 if (clp->cl_minorversion != 0)
1107 clp->cl_cb_conn.cb_xprt = conn->cb_xprt;
1108 clp->cl_cb_client = client;
1109 clp->cl_cb_cred = cred;
1110 rcu_read_lock();
1111 trace_nfsd_cb_setup(clp, netid: rpc_peeraddr2str(client, RPC_DISPLAY_NETID),
1112 authflavor: args.authflavor);
1113 rcu_read_unlock();
1114 return 0;
1115}
1116
1117static void nfsd4_mark_cb_state(struct nfs4_client *clp, int newstate)
1118{
1119 if (clp->cl_cb_state != newstate) {
1120 clp->cl_cb_state = newstate;
1121 trace_nfsd_cb_state(clp);
1122 }
1123}
1124
1125static void nfsd4_mark_cb_down(struct nfs4_client *clp, int reason)
1126{
1127 if (test_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags))
1128 return;
1129 nfsd4_mark_cb_state(clp, NFSD4_CB_DOWN);
1130}
1131
1132static void nfsd4_mark_cb_fault(struct nfs4_client *clp, int reason)
1133{
1134 if (test_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags))
1135 return;
1136 nfsd4_mark_cb_state(clp, NFSD4_CB_FAULT);
1137}
1138
1139static void nfsd4_cb_probe_done(struct rpc_task *task, void *calldata)
1140{
1141 struct nfs4_client *clp = container_of(calldata, struct nfs4_client, cl_cb_null);
1142
1143 if (task->tk_status)
1144 nfsd4_mark_cb_down(clp, reason: task->tk_status);
1145 else
1146 nfsd4_mark_cb_state(clp, NFSD4_CB_UP);
1147}
1148
1149static void nfsd4_cb_probe_release(void *calldata)
1150{
1151 struct nfs4_client *clp = container_of(calldata, struct nfs4_client, cl_cb_null);
1152
1153 nfsd41_cb_inflight_end(clp);
1154
1155}
1156
1157static const struct rpc_call_ops nfsd4_cb_probe_ops = {
1158 /* XXX: release method to ensure we set the cb channel down if
1159 * necessary on early failure? */
1160 .rpc_call_done = nfsd4_cb_probe_done,
1161 .rpc_release = nfsd4_cb_probe_release,
1162};
1163
1164/*
1165 * Poke the callback thread to process any updates to the callback
1166 * parameters, and send a null probe.
1167 */
1168void nfsd4_probe_callback(struct nfs4_client *clp)
1169{
1170 trace_nfsd_cb_probe(clp);
1171 nfsd4_mark_cb_state(clp, NFSD4_CB_UNKNOWN);
1172 set_bit(NFSD4_CLIENT_CB_UPDATE, addr: &clp->cl_flags);
1173 nfsd4_run_cb(cb: &clp->cl_cb_null);
1174}
1175
1176void nfsd4_probe_callback_sync(struct nfs4_client *clp)
1177{
1178 nfsd4_probe_callback(clp);
1179 flush_workqueue(callback_wq);
1180}
1181
1182void nfsd4_change_callback(struct nfs4_client *clp, struct nfs4_cb_conn *conn)
1183{
1184 nfsd4_mark_cb_state(clp, NFSD4_CB_UNKNOWN);
1185 spin_lock(lock: &clp->cl_lock);
1186 memcpy(&clp->cl_cb_conn, conn, sizeof(struct nfs4_cb_conn));
1187 spin_unlock(lock: &clp->cl_lock);
1188}
1189
1190/*
1191 * There's currently a single callback channel slot.
1192 * If the slot is available, then mark it busy. Otherwise, set the
1193 * thread for sleeping on the callback RPC wait queue.
1194 */
1195static bool nfsd41_cb_get_slot(struct nfsd4_callback *cb, struct rpc_task *task)
1196{
1197 struct nfs4_client *clp = cb->cb_clp;
1198
1199 if (!cb->cb_holds_slot &&
1200 test_and_set_bit(nr: 0, addr: &clp->cl_cb_slot_busy) != 0) {
1201 rpc_sleep_on(&clp->cl_cb_waitq, task, NULL);
1202 /* Race breaker */
1203 if (test_and_set_bit(nr: 0, addr: &clp->cl_cb_slot_busy) != 0) {
1204 dprintk("%s slot is busy\n", __func__);
1205 return false;
1206 }
1207 rpc_wake_up_queued_task(&clp->cl_cb_waitq, task);
1208 }
1209 cb->cb_holds_slot = true;
1210 return true;
1211}
1212
1213static void nfsd41_cb_release_slot(struct nfsd4_callback *cb)
1214{
1215 struct nfs4_client *clp = cb->cb_clp;
1216
1217 if (cb->cb_holds_slot) {
1218 cb->cb_holds_slot = false;
1219 clear_bit(nr: 0, addr: &clp->cl_cb_slot_busy);
1220 rpc_wake_up_next(&clp->cl_cb_waitq);
1221 }
1222}
1223
1224static void nfsd41_destroy_cb(struct nfsd4_callback *cb)
1225{
1226 struct nfs4_client *clp = cb->cb_clp;
1227
1228 nfsd41_cb_release_slot(cb);
1229 if (cb->cb_ops && cb->cb_ops->release)
1230 cb->cb_ops->release(cb);
1231 nfsd41_cb_inflight_end(clp);
1232}
1233
1234/*
1235 * TODO: cb_sequence should support referring call lists, cachethis, multiple
1236 * slots, and mark callback channel down on communication errors.
1237 */
1238static void nfsd4_cb_prepare(struct rpc_task *task, void *calldata)
1239{
1240 struct nfsd4_callback *cb = calldata;
1241 struct nfs4_client *clp = cb->cb_clp;
1242 u32 minorversion = clp->cl_minorversion;
1243
1244 /*
1245 * cb_seq_status is only set in decode_cb_sequence4res,
1246 * and so will remain 1 if an rpc level failure occurs.
1247 */
1248 cb->cb_seq_status = 1;
1249 cb->cb_status = 0;
1250 if (minorversion && !nfsd41_cb_get_slot(cb, task))
1251 return;
1252 rpc_call_start(task);
1253}
1254
1255static bool nfsd4_cb_sequence_done(struct rpc_task *task, struct nfsd4_callback *cb)
1256{
1257 struct nfs4_client *clp = cb->cb_clp;
1258 struct nfsd4_session *session = clp->cl_cb_session;
1259 bool ret = true;
1260
1261 if (!clp->cl_minorversion) {
1262 /*
1263 * If the backchannel connection was shut down while this
1264 * task was queued, we need to resubmit it after setting up
1265 * a new backchannel connection.
1266 *
1267 * Note that if we lost our callback connection permanently
1268 * the submission code will error out, so we don't need to
1269 * handle that case here.
1270 */
1271 if (RPC_SIGNALLED(task))
1272 goto need_restart;
1273
1274 return true;
1275 }
1276
1277 if (!cb->cb_holds_slot)
1278 goto need_restart;
1279
1280 switch (cb->cb_seq_status) {
1281 case 0:
1282 /*
1283 * No need for lock, access serialized in nfsd4_cb_prepare
1284 *
1285 * RFC5661 20.9.3
1286 * If CB_SEQUENCE returns an error, then the state of the slot
1287 * (sequence ID, cached reply) MUST NOT change.
1288 */
1289 ++session->se_cb_seq_nr;
1290 break;
1291 case -ESERVERFAULT:
1292 ++session->se_cb_seq_nr;
1293 fallthrough;
1294 case 1:
1295 case -NFS4ERR_BADSESSION:
1296 nfsd4_mark_cb_fault(clp: cb->cb_clp, reason: cb->cb_seq_status);
1297 ret = false;
1298 break;
1299 case -NFS4ERR_DELAY:
1300 if (!rpc_restart_call(task))
1301 goto out;
1302
1303 rpc_delay(task, 2 * HZ);
1304 return false;
1305 case -NFS4ERR_BADSLOT:
1306 goto retry_nowait;
1307 case -NFS4ERR_SEQ_MISORDERED:
1308 if (session->se_cb_seq_nr != 1) {
1309 session->se_cb_seq_nr = 1;
1310 goto retry_nowait;
1311 }
1312 break;
1313 default:
1314 nfsd4_mark_cb_fault(clp: cb->cb_clp, reason: cb->cb_seq_status);
1315 dprintk("%s: unprocessed error %d\n", __func__,
1316 cb->cb_seq_status);
1317 }
1318
1319 nfsd41_cb_release_slot(cb);
1320 dprintk("%s: freed slot, new seqid=%d\n", __func__,
1321 clp->cl_cb_session->se_cb_seq_nr);
1322
1323 if (RPC_SIGNALLED(task))
1324 goto need_restart;
1325out:
1326 return ret;
1327retry_nowait:
1328 if (rpc_restart_call_prepare(task))
1329 ret = false;
1330 goto out;
1331need_restart:
1332 if (!test_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags)) {
1333 task->tk_status = 0;
1334 cb->cb_need_restart = true;
1335 }
1336 return false;
1337}
1338
1339static void nfsd4_cb_done(struct rpc_task *task, void *calldata)
1340{
1341 struct nfsd4_callback *cb = calldata;
1342 struct nfs4_client *clp = cb->cb_clp;
1343
1344 if (!nfsd4_cb_sequence_done(task, cb))
1345 return;
1346
1347 if (cb->cb_status) {
1348 WARN_ON_ONCE(task->tk_status);
1349 task->tk_status = cb->cb_status;
1350 }
1351
1352 switch (cb->cb_ops->done(cb, task)) {
1353 case 0:
1354 task->tk_status = 0;
1355 rpc_restart_call_prepare(task);
1356 return;
1357 case 1:
1358 switch (task->tk_status) {
1359 case -EIO:
1360 case -ETIMEDOUT:
1361 case -EACCES:
1362 nfsd4_mark_cb_down(clp, reason: task->tk_status);
1363 }
1364 break;
1365 default:
1366 BUG();
1367 }
1368}
1369
1370static void nfsd4_cb_release(void *calldata)
1371{
1372 struct nfsd4_callback *cb = calldata;
1373
1374 if (cb->cb_need_restart)
1375 nfsd4_queue_cb(cb);
1376 else
1377 nfsd41_destroy_cb(cb);
1378
1379}
1380
1381static const struct rpc_call_ops nfsd4_cb_ops = {
1382 .rpc_call_prepare = nfsd4_cb_prepare,
1383 .rpc_call_done = nfsd4_cb_done,
1384 .rpc_release = nfsd4_cb_release,
1385};
1386
1387int nfsd4_create_callback_queue(void)
1388{
1389 callback_wq = alloc_ordered_workqueue("nfsd4_callbacks", 0);
1390 if (!callback_wq)
1391 return -ENOMEM;
1392 return 0;
1393}
1394
1395void nfsd4_destroy_callback_queue(void)
1396{
1397 destroy_workqueue(wq: callback_wq);
1398}
1399
1400/* must be called under the state lock */
1401void nfsd4_shutdown_callback(struct nfs4_client *clp)
1402{
1403 if (clp->cl_cb_state != NFSD4_CB_UNKNOWN)
1404 trace_nfsd_cb_shutdown(clp);
1405
1406 set_bit(NFSD4_CLIENT_CB_KILL, addr: &clp->cl_flags);
1407 /*
1408 * Note this won't actually result in a null callback;
1409 * instead, nfsd4_run_cb_null() will detect the killed
1410 * client, destroy the rpc client, and stop:
1411 */
1412 nfsd4_run_cb(cb: &clp->cl_cb_null);
1413 flush_workqueue(callback_wq);
1414 nfsd41_cb_inflight_wait_complete(clp);
1415}
1416
1417/* requires cl_lock: */
1418static struct nfsd4_conn * __nfsd4_find_backchannel(struct nfs4_client *clp)
1419{
1420 struct nfsd4_session *s;
1421 struct nfsd4_conn *c;
1422
1423 list_for_each_entry(s, &clp->cl_sessions, se_perclnt) {
1424 list_for_each_entry(c, &s->se_conns, cn_persession) {
1425 if (c->cn_flags & NFS4_CDFC4_BACK)
1426 return c;
1427 }
1428 }
1429 return NULL;
1430}
1431
1432/*
1433 * Note there isn't a lot of locking in this code; instead we depend on
1434 * the fact that it is run from the callback_wq, which won't run two
1435 * work items at once. So, for example, callback_wq handles all access
1436 * of cl_cb_client and all calls to rpc_create or rpc_shutdown_client.
1437 */
1438static void nfsd4_process_cb_update(struct nfsd4_callback *cb)
1439{
1440 struct nfs4_cb_conn conn;
1441 struct nfs4_client *clp = cb->cb_clp;
1442 struct nfsd4_session *ses = NULL;
1443 struct nfsd4_conn *c;
1444 int err;
1445
1446 /*
1447 * This is either an update, or the client dying; in either case,
1448 * kill the old client:
1449 */
1450 if (clp->cl_cb_client) {
1451 rpc_shutdown_client(clp->cl_cb_client);
1452 clp->cl_cb_client = NULL;
1453 put_cred(cred: clp->cl_cb_cred);
1454 clp->cl_cb_cred = NULL;
1455 }
1456 if (clp->cl_cb_conn.cb_xprt) {
1457 svc_xprt_put(xprt: clp->cl_cb_conn.cb_xprt);
1458 clp->cl_cb_conn.cb_xprt = NULL;
1459 }
1460 if (test_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags))
1461 return;
1462 spin_lock(lock: &clp->cl_lock);
1463 /*
1464 * Only serialized callback code is allowed to clear these
1465 * flags; main nfsd code can only set them:
1466 */
1467 BUG_ON(!(clp->cl_flags & NFSD4_CLIENT_CB_FLAG_MASK));
1468 clear_bit(NFSD4_CLIENT_CB_UPDATE, addr: &clp->cl_flags);
1469 memcpy(&conn, &cb->cb_clp->cl_cb_conn, sizeof(struct nfs4_cb_conn));
1470 c = __nfsd4_find_backchannel(clp);
1471 if (c) {
1472 svc_xprt_get(xprt: c->cn_xprt);
1473 conn.cb_xprt = c->cn_xprt;
1474 ses = c->cn_session;
1475 }
1476 spin_unlock(lock: &clp->cl_lock);
1477
1478 err = setup_callback_client(clp, conn: &conn, ses);
1479 if (err) {
1480 nfsd4_mark_cb_down(clp, reason: err);
1481 if (c)
1482 svc_xprt_put(xprt: c->cn_xprt);
1483 return;
1484 }
1485}
1486
1487static void
1488nfsd4_run_cb_work(struct work_struct *work)
1489{
1490 struct nfsd4_callback *cb =
1491 container_of(work, struct nfsd4_callback, cb_work);
1492 struct nfs4_client *clp = cb->cb_clp;
1493 struct rpc_clnt *clnt;
1494 int flags;
1495
1496 if (cb->cb_need_restart) {
1497 cb->cb_need_restart = false;
1498 } else {
1499 if (cb->cb_ops && cb->cb_ops->prepare)
1500 cb->cb_ops->prepare(cb);
1501 }
1502
1503 if (clp->cl_flags & NFSD4_CLIENT_CB_FLAG_MASK)
1504 nfsd4_process_cb_update(cb);
1505
1506 clnt = clp->cl_cb_client;
1507 if (!clnt) {
1508 /* Callback channel broken, or client killed; give up: */
1509 nfsd41_destroy_cb(cb);
1510 return;
1511 }
1512
1513 /*
1514 * Don't send probe messages for 4.1 or later.
1515 */
1516 if (!cb->cb_ops && clp->cl_minorversion) {
1517 nfsd4_mark_cb_state(clp, NFSD4_CB_UP);
1518 nfsd41_destroy_cb(cb);
1519 return;
1520 }
1521
1522 cb->cb_msg.rpc_cred = clp->cl_cb_cred;
1523 flags = clp->cl_minorversion ? RPC_TASK_NOCONNECT : RPC_TASK_SOFTCONN;
1524 rpc_call_async(clnt, msg: &cb->cb_msg, RPC_TASK_SOFT | flags,
1525 tk_ops: cb->cb_ops ? &nfsd4_cb_ops : &nfsd4_cb_probe_ops, calldata: cb);
1526}
1527
1528void nfsd4_init_cb(struct nfsd4_callback *cb, struct nfs4_client *clp,
1529 const struct nfsd4_callback_ops *ops, enum nfsd4_cb_op op)
1530{
1531 cb->cb_clp = clp;
1532 cb->cb_msg.rpc_proc = &nfs4_cb_procedures[op];
1533 cb->cb_msg.rpc_argp = cb;
1534 cb->cb_msg.rpc_resp = cb;
1535 cb->cb_ops = ops;
1536 INIT_WORK(&cb->cb_work, nfsd4_run_cb_work);
1537 cb->cb_seq_status = 1;
1538 cb->cb_status = 0;
1539 cb->cb_need_restart = false;
1540 cb->cb_holds_slot = false;
1541}
1542
1543/**
1544 * nfsd4_run_cb - queue up a callback job to run
1545 * @cb: callback to queue
1546 *
1547 * Kick off a callback to do its thing. Returns false if it was already
1548 * on a queue, true otherwise.
1549 */
1550bool nfsd4_run_cb(struct nfsd4_callback *cb)
1551{
1552 struct nfs4_client *clp = cb->cb_clp;
1553 bool queued;
1554
1555 nfsd41_cb_inflight_begin(clp);
1556 queued = nfsd4_queue_cb(cb);
1557 if (!queued)
1558 nfsd41_cb_inflight_end(clp);
1559 return queued;
1560}
1561

source code of linux/fs/nfsd/nfs4callback.c