1/*
2 * Copyright (c) 2001 The Regents of the University of Michigan.
3 * All rights reserved.
4 *
5 * Kendrick Smith <kmsmith@umich.edu>
6 * Andy Adamson <andros@umich.edu>
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 *
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 * 3. Neither the name of the University nor the names of its
18 * contributors may be used to endorse or promote products derived
19 * from this software without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
22 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
23 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
24 * DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
26 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
27 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
28 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
29 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
30 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
31 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32 */
33
34#include <linux/nfs4.h>
35#include <linux/sunrpc/clnt.h>
36#include <linux/sunrpc/xprt.h>
37#include <linux/sunrpc/svc_xprt.h>
38#include <linux/slab.h>
39#include "nfsd.h"
40#include "state.h"
41#include "netns.h"
42#include "trace.h"
43#include "xdr4cb.h"
44#include "xdr4.h"
45
46#define NFSDDBG_FACILITY NFSDDBG_PROC
47
48static void nfsd4_mark_cb_fault(struct nfs4_client *clp);
49
50#define NFSPROC4_CB_NULL 0
51#define NFSPROC4_CB_COMPOUND 1
52
53/* Index of predefined Linux callback client operations */
54
55struct nfs4_cb_compound_hdr {
56 /* args */
57 u32 ident; /* minorversion 0 only */
58 u32 nops;
59 __be32 *nops_p;
60 u32 minorversion;
61 /* res */
62 int status;
63};
64
65static __be32 *xdr_encode_empty_array(__be32 *p)
66{
67 *p++ = xdr_zero;
68 return p;
69}
70
71/*
72 * Encode/decode NFSv4 CB basic data types
73 *
74 * Basic NFSv4 callback data types are defined in section 15 of RFC
75 * 3530: "Network File System (NFS) version 4 Protocol" and section
76 * 20 of RFC 5661: "Network File System (NFS) Version 4 Minor Version
77 * 1 Protocol"
78 */
79
80static void encode_uint32(struct xdr_stream *xdr, u32 n)
81{
82 WARN_ON_ONCE(xdr_stream_encode_u32(xdr, n) < 0);
83}
84
85static void encode_bitmap4(struct xdr_stream *xdr, const __u32 *bitmap,
86 size_t len)
87{
88 xdr_stream_encode_uint32_array(xdr, array: bitmap, array_size: len);
89}
90
91static int decode_cb_fattr4(struct xdr_stream *xdr, uint32_t *bitmap,
92 struct nfs4_cb_fattr *fattr)
93{
94 fattr->ncf_cb_change = 0;
95 fattr->ncf_cb_fsize = 0;
96 if (bitmap[0] & FATTR4_WORD0_CHANGE)
97 if (xdr_stream_decode_u64(xdr, ptr: &fattr->ncf_cb_change) < 0)
98 return -NFSERR_BAD_XDR;
99 if (bitmap[0] & FATTR4_WORD0_SIZE)
100 if (xdr_stream_decode_u64(xdr, ptr: &fattr->ncf_cb_fsize) < 0)
101 return -NFSERR_BAD_XDR;
102 return 0;
103}
104
105static void encode_nfs_cb_opnum4(struct xdr_stream *xdr, enum nfs_cb_opnum4 op)
106{
107 __be32 *p;
108
109 p = xdr_reserve_space(xdr, nbytes: 4);
110 *p = cpu_to_be32(op);
111}
112
113/*
114 * nfs_fh4
115 *
116 * typedef opaque nfs_fh4<NFS4_FHSIZE>;
117 */
118static void encode_nfs_fh4(struct xdr_stream *xdr, const struct knfsd_fh *fh)
119{
120 u32 length = fh->fh_size;
121 __be32 *p;
122
123 BUG_ON(length > NFS4_FHSIZE);
124 p = xdr_reserve_space(xdr, nbytes: 4 + length);
125 xdr_encode_opaque(p, ptr: &fh->fh_raw, len: length);
126}
127
128/*
129 * stateid4
130 *
131 * struct stateid4 {
132 * uint32_t seqid;
133 * opaque other[12];
134 * };
135 */
136static void encode_stateid4(struct xdr_stream *xdr, const stateid_t *sid)
137{
138 __be32 *p;
139
140 p = xdr_reserve_space(xdr, NFS4_STATEID_SIZE);
141 *p++ = cpu_to_be32(sid->si_generation);
142 xdr_encode_opaque_fixed(p, ptr: &sid->si_opaque, NFS4_STATEID_OTHER_SIZE);
143}
144
145/*
146 * sessionid4
147 *
148 * typedef opaque sessionid4[NFS4_SESSIONID_SIZE];
149 */
150static void encode_sessionid4(struct xdr_stream *xdr,
151 const struct nfsd4_session *session)
152{
153 __be32 *p;
154
155 p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN);
156 xdr_encode_opaque_fixed(p, ptr: session->se_sessionid.data,
157 NFS4_MAX_SESSIONID_LEN);
158}
159
160/*
161 * nfsstat4
162 */
163static const struct {
164 int stat;
165 int errno;
166} nfs_cb_errtbl[] = {
167 { NFS4_OK, 0 },
168 { NFS4ERR_PERM, -EPERM },
169 { NFS4ERR_NOENT, -ENOENT },
170 { NFS4ERR_IO, -EIO },
171 { NFS4ERR_NXIO, -ENXIO },
172 { NFS4ERR_ACCESS, -EACCES },
173 { NFS4ERR_EXIST, -EEXIST },
174 { NFS4ERR_XDEV, -EXDEV },
175 { NFS4ERR_NOTDIR, -ENOTDIR },
176 { NFS4ERR_ISDIR, -EISDIR },
177 { NFS4ERR_INVAL, -EINVAL },
178 { NFS4ERR_FBIG, -EFBIG },
179 { NFS4ERR_NOSPC, -ENOSPC },
180 { NFS4ERR_ROFS, -EROFS },
181 { NFS4ERR_MLINK, -EMLINK },
182 { NFS4ERR_NAMETOOLONG, -ENAMETOOLONG },
183 { NFS4ERR_NOTEMPTY, -ENOTEMPTY },
184 { NFS4ERR_DQUOT, -EDQUOT },
185 { NFS4ERR_STALE, -ESTALE },
186 { NFS4ERR_BADHANDLE, -EBADHANDLE },
187 { NFS4ERR_BAD_COOKIE, -EBADCOOKIE },
188 { NFS4ERR_NOTSUPP, -ENOTSUPP },
189 { NFS4ERR_TOOSMALL, -ETOOSMALL },
190 { NFS4ERR_SERVERFAULT, -ESERVERFAULT },
191 { NFS4ERR_BADTYPE, -EBADTYPE },
192 { NFS4ERR_LOCKED, -EAGAIN },
193 { NFS4ERR_RESOURCE, -EREMOTEIO },
194 { NFS4ERR_SYMLINK, -ELOOP },
195 { NFS4ERR_OP_ILLEGAL, -EOPNOTSUPP },
196 { NFS4ERR_DEADLOCK, -EDEADLK },
197 { -1, -EIO }
198};
199
200/*
201 * If we cannot translate the error, the recovery routines should
202 * handle it.
203 *
204 * Note: remaining NFSv4 error codes have values > 10000, so should
205 * not conflict with native Linux error codes.
206 */
207static int nfs_cb_stat_to_errno(int status)
208{
209 int i;
210
211 for (i = 0; nfs_cb_errtbl[i].stat != -1; i++) {
212 if (nfs_cb_errtbl[i].stat == status)
213 return nfs_cb_errtbl[i].errno;
214 }
215
216 dprintk("NFSD: Unrecognized NFS CB status value: %u\n", status);
217 return -status;
218}
219
220static int decode_cb_op_status(struct xdr_stream *xdr,
221 enum nfs_cb_opnum4 expected, int *status)
222{
223 __be32 *p;
224 u32 op;
225
226 p = xdr_inline_decode(xdr, nbytes: 4 + 4);
227 if (unlikely(p == NULL))
228 goto out_overflow;
229 op = be32_to_cpup(p: p++);
230 if (unlikely(op != expected))
231 goto out_unexpected;
232 *status = nfs_cb_stat_to_errno(be32_to_cpup(p));
233 return 0;
234out_overflow:
235 return -EIO;
236out_unexpected:
237 dprintk("NFSD: Callback server returned operation %d but "
238 "we issued a request for %d\n", op, expected);
239 return -EIO;
240}
241
242/*
243 * CB_COMPOUND4args
244 *
245 * struct CB_COMPOUND4args {
246 * utf8str_cs tag;
247 * uint32_t minorversion;
248 * uint32_t callback_ident;
249 * nfs_cb_argop4 argarray<>;
250 * };
251*/
252static void encode_cb_compound4args(struct xdr_stream *xdr,
253 struct nfs4_cb_compound_hdr *hdr)
254{
255 __be32 * p;
256
257 p = xdr_reserve_space(xdr, nbytes: 4 + 4 + 4 + 4);
258 p = xdr_encode_empty_array(p); /* empty tag */
259 *p++ = cpu_to_be32(hdr->minorversion);
260 *p++ = cpu_to_be32(hdr->ident);
261
262 hdr->nops_p = p;
263 *p = cpu_to_be32(hdr->nops); /* argarray element count */
264}
265
266/*
267 * Update argarray element count
268 */
269static void encode_cb_nops(struct nfs4_cb_compound_hdr *hdr)
270{
271 BUG_ON(hdr->nops > NFS4_MAX_BACK_CHANNEL_OPS);
272 *hdr->nops_p = cpu_to_be32(hdr->nops);
273}
274
275/*
276 * CB_COMPOUND4res
277 *
278 * struct CB_COMPOUND4res {
279 * nfsstat4 status;
280 * utf8str_cs tag;
281 * nfs_cb_resop4 resarray<>;
282 * };
283 */
284static int decode_cb_compound4res(struct xdr_stream *xdr,
285 struct nfs4_cb_compound_hdr *hdr)
286{
287 u32 length;
288 __be32 *p;
289
290 p = xdr_inline_decode(xdr, nbytes: 4 + 4);
291 if (unlikely(p == NULL))
292 goto out_overflow;
293 hdr->status = be32_to_cpup(p: p++);
294 /* Ignore the tag */
295 length = be32_to_cpup(p: p++);
296 p = xdr_inline_decode(xdr, nbytes: length + 4);
297 if (unlikely(p == NULL))
298 goto out_overflow;
299 p += XDR_QUADLEN(length);
300 hdr->nops = be32_to_cpup(p);
301 return 0;
302out_overflow:
303 return -EIO;
304}
305
306/*
307 * CB_RECALL4args
308 *
309 * struct CB_RECALL4args {
310 * stateid4 stateid;
311 * bool truncate;
312 * nfs_fh4 fh;
313 * };
314 */
315static void encode_cb_recall4args(struct xdr_stream *xdr,
316 const struct nfs4_delegation *dp,
317 struct nfs4_cb_compound_hdr *hdr)
318{
319 __be32 *p;
320
321 encode_nfs_cb_opnum4(xdr, op: OP_CB_RECALL);
322 encode_stateid4(xdr, sid: &dp->dl_stid.sc_stateid);
323
324 p = xdr_reserve_space(xdr, nbytes: 4);
325 *p++ = xdr_zero; /* truncate */
326
327 encode_nfs_fh4(xdr, fh: &dp->dl_stid.sc_file->fi_fhandle);
328
329 hdr->nops++;
330}
331
332/*
333 * CB_RECALLANY4args
334 *
335 * struct CB_RECALLANY4args {
336 * uint32_t craa_objects_to_keep;
337 * bitmap4 craa_type_mask;
338 * };
339 */
340static void
341encode_cb_recallany4args(struct xdr_stream *xdr,
342 struct nfs4_cb_compound_hdr *hdr, struct nfsd4_cb_recall_any *ra)
343{
344 encode_nfs_cb_opnum4(xdr, op: OP_CB_RECALL_ANY);
345 encode_uint32(xdr, n: ra->ra_keep);
346 encode_bitmap4(xdr, bitmap: ra->ra_bmval, ARRAY_SIZE(ra->ra_bmval));
347 hdr->nops++;
348}
349
350/*
351 * CB_GETATTR4args
352 * struct CB_GETATTR4args {
353 * nfs_fh4 fh;
354 * bitmap4 attr_request;
355 * };
356 *
357 * The size and change attributes are the only one
358 * guaranteed to be serviced by the client.
359 */
360static void
361encode_cb_getattr4args(struct xdr_stream *xdr, struct nfs4_cb_compound_hdr *hdr,
362 struct nfs4_cb_fattr *fattr)
363{
364 struct nfs4_delegation *dp =
365 container_of(fattr, struct nfs4_delegation, dl_cb_fattr);
366 struct knfsd_fh *fh = &dp->dl_stid.sc_file->fi_fhandle;
367
368 encode_nfs_cb_opnum4(xdr, op: OP_CB_GETATTR);
369 encode_nfs_fh4(xdr, fh);
370 encode_bitmap4(xdr, bitmap: fattr->ncf_cb_bmap, ARRAY_SIZE(fattr->ncf_cb_bmap));
371 hdr->nops++;
372}
373
374/*
375 * CB_SEQUENCE4args
376 *
377 * struct CB_SEQUENCE4args {
378 * sessionid4 csa_sessionid;
379 * sequenceid4 csa_sequenceid;
380 * slotid4 csa_slotid;
381 * slotid4 csa_highest_slotid;
382 * bool csa_cachethis;
383 * referring_call_list4 csa_referring_call_lists<>;
384 * };
385 */
386static void encode_cb_sequence4args(struct xdr_stream *xdr,
387 const struct nfsd4_callback *cb,
388 struct nfs4_cb_compound_hdr *hdr)
389{
390 struct nfsd4_session *session = cb->cb_clp->cl_cb_session;
391 __be32 *p;
392
393 if (hdr->minorversion == 0)
394 return;
395
396 encode_nfs_cb_opnum4(xdr, op: OP_CB_SEQUENCE);
397 encode_sessionid4(xdr, session);
398
399 p = xdr_reserve_space(xdr, nbytes: 4 + 4 + 4 + 4 + 4);
400 *p++ = cpu_to_be32(session->se_cb_seq_nr); /* csa_sequenceid */
401 *p++ = xdr_zero; /* csa_slotid */
402 *p++ = xdr_zero; /* csa_highest_slotid */
403 *p++ = xdr_zero; /* csa_cachethis */
404 xdr_encode_empty_array(p); /* csa_referring_call_lists */
405
406 hdr->nops++;
407}
408
409/*
410 * CB_SEQUENCE4resok
411 *
412 * struct CB_SEQUENCE4resok {
413 * sessionid4 csr_sessionid;
414 * sequenceid4 csr_sequenceid;
415 * slotid4 csr_slotid;
416 * slotid4 csr_highest_slotid;
417 * slotid4 csr_target_highest_slotid;
418 * };
419 *
420 * union CB_SEQUENCE4res switch (nfsstat4 csr_status) {
421 * case NFS4_OK:
422 * CB_SEQUENCE4resok csr_resok4;
423 * default:
424 * void;
425 * };
426 *
427 * Our current back channel implmentation supports a single backchannel
428 * with a single slot.
429 */
430static int decode_cb_sequence4resok(struct xdr_stream *xdr,
431 struct nfsd4_callback *cb)
432{
433 struct nfsd4_session *session = cb->cb_clp->cl_cb_session;
434 int status = -ESERVERFAULT;
435 __be32 *p;
436 u32 dummy;
437
438 /*
439 * If the server returns different values for sessionID, slotID or
440 * sequence number, the server is looney tunes.
441 */
442 p = xdr_inline_decode(xdr, NFS4_MAX_SESSIONID_LEN + 4 + 4 + 4 + 4);
443 if (unlikely(p == NULL))
444 goto out_overflow;
445
446 if (memcmp(p, q: session->se_sessionid.data, NFS4_MAX_SESSIONID_LEN)) {
447 dprintk("NFS: %s Invalid session id\n", __func__);
448 goto out;
449 }
450 p += XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN);
451
452 dummy = be32_to_cpup(p: p++);
453 if (dummy != session->se_cb_seq_nr) {
454 dprintk("NFS: %s Invalid sequence number\n", __func__);
455 goto out;
456 }
457
458 dummy = be32_to_cpup(p: p++);
459 if (dummy != 0) {
460 dprintk("NFS: %s Invalid slotid\n", __func__);
461 goto out;
462 }
463
464 /*
465 * FIXME: process highest slotid and target highest slotid
466 */
467 status = 0;
468out:
469 cb->cb_seq_status = status;
470 return status;
471out_overflow:
472 status = -EIO;
473 goto out;
474}
475
476static int decode_cb_sequence4res(struct xdr_stream *xdr,
477 struct nfsd4_callback *cb)
478{
479 int status;
480
481 if (cb->cb_clp->cl_minorversion == 0)
482 return 0;
483
484 status = decode_cb_op_status(xdr, expected: OP_CB_SEQUENCE, status: &cb->cb_seq_status);
485 if (unlikely(status || cb->cb_seq_status))
486 return status;
487
488 return decode_cb_sequence4resok(xdr, cb);
489}
490
491/*
492 * NFSv4.0 and NFSv4.1 XDR encode functions
493 *
494 * NFSv4.0 callback argument types are defined in section 15 of RFC
495 * 3530: "Network File System (NFS) version 4 Protocol" and section 20
496 * of RFC 5661: "Network File System (NFS) Version 4 Minor Version 1
497 * Protocol".
498 */
499
500/*
501 * NB: Without this zero space reservation, callbacks over krb5p fail
502 */
503static void nfs4_xdr_enc_cb_null(struct rpc_rqst *req, struct xdr_stream *xdr,
504 const void *__unused)
505{
506 xdr_reserve_space(xdr, nbytes: 0);
507}
508
509/*
510 * 20.1. Operation 3: CB_GETATTR - Get Attributes
511 */
512static void nfs4_xdr_enc_cb_getattr(struct rpc_rqst *req,
513 struct xdr_stream *xdr, const void *data)
514{
515 const struct nfsd4_callback *cb = data;
516 struct nfs4_cb_fattr *ncf =
517 container_of(cb, struct nfs4_cb_fattr, ncf_getattr);
518 struct nfs4_cb_compound_hdr hdr = {
519 .ident = cb->cb_clp->cl_cb_ident,
520 .minorversion = cb->cb_clp->cl_minorversion,
521 };
522
523 encode_cb_compound4args(xdr, hdr: &hdr);
524 encode_cb_sequence4args(xdr, cb, hdr: &hdr);
525 encode_cb_getattr4args(xdr, hdr: &hdr, fattr: ncf);
526 encode_cb_nops(hdr: &hdr);
527}
528
529/*
530 * 20.2. Operation 4: CB_RECALL - Recall a Delegation
531 */
532static void nfs4_xdr_enc_cb_recall(struct rpc_rqst *req, struct xdr_stream *xdr,
533 const void *data)
534{
535 const struct nfsd4_callback *cb = data;
536 const struct nfs4_delegation *dp = cb_to_delegation(cb);
537 struct nfs4_cb_compound_hdr hdr = {
538 .ident = cb->cb_clp->cl_cb_ident,
539 .minorversion = cb->cb_clp->cl_minorversion,
540 };
541
542 encode_cb_compound4args(xdr, hdr: &hdr);
543 encode_cb_sequence4args(xdr, cb, hdr: &hdr);
544 encode_cb_recall4args(xdr, dp, hdr: &hdr);
545 encode_cb_nops(hdr: &hdr);
546}
547
548/*
549 * 20.6. Operation 8: CB_RECALL_ANY - Keep Any N Recallable Objects
550 */
551static void
552nfs4_xdr_enc_cb_recall_any(struct rpc_rqst *req,
553 struct xdr_stream *xdr, const void *data)
554{
555 const struct nfsd4_callback *cb = data;
556 struct nfsd4_cb_recall_any *ra;
557 struct nfs4_cb_compound_hdr hdr = {
558 .ident = cb->cb_clp->cl_cb_ident,
559 .minorversion = cb->cb_clp->cl_minorversion,
560 };
561
562 ra = container_of(cb, struct nfsd4_cb_recall_any, ra_cb);
563 encode_cb_compound4args(xdr, hdr: &hdr);
564 encode_cb_sequence4args(xdr, cb, hdr: &hdr);
565 encode_cb_recallany4args(xdr, hdr: &hdr, ra);
566 encode_cb_nops(hdr: &hdr);
567}
568
569/*
570 * NFSv4.0 and NFSv4.1 XDR decode functions
571 *
572 * NFSv4.0 callback result types are defined in section 15 of RFC
573 * 3530: "Network File System (NFS) version 4 Protocol" and section 20
574 * of RFC 5661: "Network File System (NFS) Version 4 Minor Version 1
575 * Protocol".
576 */
577
578static int nfs4_xdr_dec_cb_null(struct rpc_rqst *req, struct xdr_stream *xdr,
579 void *__unused)
580{
581 return 0;
582}
583
584/*
585 * 20.1. Operation 3: CB_GETATTR - Get Attributes
586 */
587static int nfs4_xdr_dec_cb_getattr(struct rpc_rqst *rqstp,
588 struct xdr_stream *xdr,
589 void *data)
590{
591 struct nfsd4_callback *cb = data;
592 struct nfs4_cb_compound_hdr hdr;
593 int status;
594 u32 bitmap[3] = {0};
595 u32 attrlen;
596 struct nfs4_cb_fattr *ncf =
597 container_of(cb, struct nfs4_cb_fattr, ncf_getattr);
598
599 status = decode_cb_compound4res(xdr, hdr: &hdr);
600 if (unlikely(status))
601 return status;
602
603 status = decode_cb_sequence4res(xdr, cb);
604 if (unlikely(status || cb->cb_seq_status))
605 return status;
606
607 status = decode_cb_op_status(xdr, expected: OP_CB_GETATTR, status: &cb->cb_status);
608 if (status)
609 return status;
610 if (xdr_stream_decode_uint32_array(xdr, array: bitmap, array_size: 3) < 0)
611 return -NFSERR_BAD_XDR;
612 if (xdr_stream_decode_u32(xdr, ptr: &attrlen) < 0)
613 return -NFSERR_BAD_XDR;
614 if (attrlen > (sizeof(ncf->ncf_cb_change) + sizeof(ncf->ncf_cb_fsize)))
615 return -NFSERR_BAD_XDR;
616 status = decode_cb_fattr4(xdr, bitmap, fattr: ncf);
617 return status;
618}
619
620/*
621 * 20.2. Operation 4: CB_RECALL - Recall a Delegation
622 */
623static int nfs4_xdr_dec_cb_recall(struct rpc_rqst *rqstp,
624 struct xdr_stream *xdr,
625 void *data)
626{
627 struct nfsd4_callback *cb = data;
628 struct nfs4_cb_compound_hdr hdr;
629 int status;
630
631 status = decode_cb_compound4res(xdr, hdr: &hdr);
632 if (unlikely(status))
633 return status;
634
635 status = decode_cb_sequence4res(xdr, cb);
636 if (unlikely(status || cb->cb_seq_status))
637 return status;
638
639 return decode_cb_op_status(xdr, expected: OP_CB_RECALL, status: &cb->cb_status);
640}
641
642/*
643 * 20.6. Operation 8: CB_RECALL_ANY - Keep Any N Recallable Objects
644 */
645static int
646nfs4_xdr_dec_cb_recall_any(struct rpc_rqst *rqstp,
647 struct xdr_stream *xdr,
648 void *data)
649{
650 struct nfsd4_callback *cb = data;
651 struct nfs4_cb_compound_hdr hdr;
652 int status;
653
654 status = decode_cb_compound4res(xdr, hdr: &hdr);
655 if (unlikely(status))
656 return status;
657 status = decode_cb_sequence4res(xdr, cb);
658 if (unlikely(status || cb->cb_seq_status))
659 return status;
660 status = decode_cb_op_status(xdr, expected: OP_CB_RECALL_ANY, status: &cb->cb_status);
661 return status;
662}
663
664#ifdef CONFIG_NFSD_PNFS
665/*
666 * CB_LAYOUTRECALL4args
667 *
668 * struct layoutrecall_file4 {
669 * nfs_fh4 lor_fh;
670 * offset4 lor_offset;
671 * length4 lor_length;
672 * stateid4 lor_stateid;
673 * };
674 *
675 * union layoutrecall4 switch(layoutrecall_type4 lor_recalltype) {
676 * case LAYOUTRECALL4_FILE:
677 * layoutrecall_file4 lor_layout;
678 * case LAYOUTRECALL4_FSID:
679 * fsid4 lor_fsid;
680 * case LAYOUTRECALL4_ALL:
681 * void;
682 * };
683 *
684 * struct CB_LAYOUTRECALL4args {
685 * layouttype4 clora_type;
686 * layoutiomode4 clora_iomode;
687 * bool clora_changed;
688 * layoutrecall4 clora_recall;
689 * };
690 */
691static void encode_cb_layout4args(struct xdr_stream *xdr,
692 const struct nfs4_layout_stateid *ls,
693 struct nfs4_cb_compound_hdr *hdr)
694{
695 __be32 *p;
696
697 BUG_ON(hdr->minorversion == 0);
698
699 p = xdr_reserve_space(xdr, nbytes: 5 * 4);
700 *p++ = cpu_to_be32(OP_CB_LAYOUTRECALL);
701 *p++ = cpu_to_be32(ls->ls_layout_type);
702 *p++ = cpu_to_be32(IOMODE_ANY);
703 *p++ = cpu_to_be32(1);
704 *p = cpu_to_be32(RETURN_FILE);
705
706 encode_nfs_fh4(xdr, fh: &ls->ls_stid.sc_file->fi_fhandle);
707
708 p = xdr_reserve_space(xdr, nbytes: 2 * 8);
709 p = xdr_encode_hyper(p, val: 0);
710 xdr_encode_hyper(p, NFS4_MAX_UINT64);
711
712 encode_stateid4(xdr, sid: &ls->ls_recall_sid);
713
714 hdr->nops++;
715}
716
717static void nfs4_xdr_enc_cb_layout(struct rpc_rqst *req,
718 struct xdr_stream *xdr,
719 const void *data)
720{
721 const struct nfsd4_callback *cb = data;
722 const struct nfs4_layout_stateid *ls =
723 container_of(cb, struct nfs4_layout_stateid, ls_recall);
724 struct nfs4_cb_compound_hdr hdr = {
725 .ident = 0,
726 .minorversion = cb->cb_clp->cl_minorversion,
727 };
728
729 encode_cb_compound4args(xdr, hdr: &hdr);
730 encode_cb_sequence4args(xdr, cb, hdr: &hdr);
731 encode_cb_layout4args(xdr, ls, hdr: &hdr);
732 encode_cb_nops(hdr: &hdr);
733}
734
735static int nfs4_xdr_dec_cb_layout(struct rpc_rqst *rqstp,
736 struct xdr_stream *xdr,
737 void *data)
738{
739 struct nfsd4_callback *cb = data;
740 struct nfs4_cb_compound_hdr hdr;
741 int status;
742
743 status = decode_cb_compound4res(xdr, hdr: &hdr);
744 if (unlikely(status))
745 return status;
746
747 status = decode_cb_sequence4res(xdr, cb);
748 if (unlikely(status || cb->cb_seq_status))
749 return status;
750
751 return decode_cb_op_status(xdr, expected: OP_CB_LAYOUTRECALL, status: &cb->cb_status);
752}
753#endif /* CONFIG_NFSD_PNFS */
754
755static void encode_stateowner(struct xdr_stream *xdr, struct nfs4_stateowner *so)
756{
757 __be32 *p;
758
759 p = xdr_reserve_space(xdr, nbytes: 8 + 4 + so->so_owner.len);
760 p = xdr_encode_opaque_fixed(p, ptr: &so->so_client->cl_clientid, len: 8);
761 xdr_encode_opaque(p, ptr: so->so_owner.data, len: so->so_owner.len);
762}
763
764static void nfs4_xdr_enc_cb_notify_lock(struct rpc_rqst *req,
765 struct xdr_stream *xdr,
766 const void *data)
767{
768 const struct nfsd4_callback *cb = data;
769 const struct nfsd4_blocked_lock *nbl =
770 container_of(cb, struct nfsd4_blocked_lock, nbl_cb);
771 struct nfs4_lockowner *lo = (struct nfs4_lockowner *)nbl->nbl_lock.c.flc_owner;
772 struct nfs4_cb_compound_hdr hdr = {
773 .ident = 0,
774 .minorversion = cb->cb_clp->cl_minorversion,
775 };
776
777 __be32 *p;
778
779 BUG_ON(hdr.minorversion == 0);
780
781 encode_cb_compound4args(xdr, hdr: &hdr);
782 encode_cb_sequence4args(xdr, cb, hdr: &hdr);
783
784 p = xdr_reserve_space(xdr, nbytes: 4);
785 *p = cpu_to_be32(OP_CB_NOTIFY_LOCK);
786 encode_nfs_fh4(xdr, fh: &nbl->nbl_fh);
787 encode_stateowner(xdr, so: &lo->lo_owner);
788 hdr.nops++;
789
790 encode_cb_nops(hdr: &hdr);
791}
792
793static int nfs4_xdr_dec_cb_notify_lock(struct rpc_rqst *rqstp,
794 struct xdr_stream *xdr,
795 void *data)
796{
797 struct nfsd4_callback *cb = data;
798 struct nfs4_cb_compound_hdr hdr;
799 int status;
800
801 status = decode_cb_compound4res(xdr, hdr: &hdr);
802 if (unlikely(status))
803 return status;
804
805 status = decode_cb_sequence4res(xdr, cb);
806 if (unlikely(status || cb->cb_seq_status))
807 return status;
808
809 return decode_cb_op_status(xdr, expected: OP_CB_NOTIFY_LOCK, status: &cb->cb_status);
810}
811
812/*
813 * struct write_response4 {
814 * stateid4 wr_callback_id<1>;
815 * length4 wr_count;
816 * stable_how4 wr_committed;
817 * verifier4 wr_writeverf;
818 * };
819 * union offload_info4 switch (nfsstat4 coa_status) {
820 * case NFS4_OK:
821 * write_response4 coa_resok4;
822 * default:
823 * length4 coa_bytes_copied;
824 * };
825 * struct CB_OFFLOAD4args {
826 * nfs_fh4 coa_fh;
827 * stateid4 coa_stateid;
828 * offload_info4 coa_offload_info;
829 * };
830 */
831static void encode_offload_info4(struct xdr_stream *xdr,
832 const struct nfsd4_cb_offload *cbo)
833{
834 __be32 *p;
835
836 p = xdr_reserve_space(xdr, nbytes: 4);
837 *p = cbo->co_nfserr;
838 switch (cbo->co_nfserr) {
839 case nfs_ok:
840 p = xdr_reserve_space(xdr, nbytes: 4 + 8 + 4 + NFS4_VERIFIER_SIZE);
841 p = xdr_encode_empty_array(p);
842 p = xdr_encode_hyper(p, val: cbo->co_res.wr_bytes_written);
843 *p++ = cpu_to_be32(cbo->co_res.wr_stable_how);
844 p = xdr_encode_opaque_fixed(p, ptr: cbo->co_res.wr_verifier.data,
845 NFS4_VERIFIER_SIZE);
846 break;
847 default:
848 p = xdr_reserve_space(xdr, nbytes: 8);
849 /* We always return success if bytes were written */
850 p = xdr_encode_hyper(p, val: 0);
851 }
852}
853
854static void encode_cb_offload4args(struct xdr_stream *xdr,
855 const struct nfsd4_cb_offload *cbo,
856 struct nfs4_cb_compound_hdr *hdr)
857{
858 __be32 *p;
859
860 p = xdr_reserve_space(xdr, nbytes: 4);
861 *p = cpu_to_be32(OP_CB_OFFLOAD);
862 encode_nfs_fh4(xdr, fh: &cbo->co_fh);
863 encode_stateid4(xdr, sid: &cbo->co_res.cb_stateid);
864 encode_offload_info4(xdr, cbo);
865
866 hdr->nops++;
867}
868
869static void nfs4_xdr_enc_cb_offload(struct rpc_rqst *req,
870 struct xdr_stream *xdr,
871 const void *data)
872{
873 const struct nfsd4_callback *cb = data;
874 const struct nfsd4_cb_offload *cbo =
875 container_of(cb, struct nfsd4_cb_offload, co_cb);
876 struct nfs4_cb_compound_hdr hdr = {
877 .ident = 0,
878 .minorversion = cb->cb_clp->cl_minorversion,
879 };
880
881 encode_cb_compound4args(xdr, hdr: &hdr);
882 encode_cb_sequence4args(xdr, cb, hdr: &hdr);
883 encode_cb_offload4args(xdr, cbo, hdr: &hdr);
884 encode_cb_nops(hdr: &hdr);
885}
886
887static int nfs4_xdr_dec_cb_offload(struct rpc_rqst *rqstp,
888 struct xdr_stream *xdr,
889 void *data)
890{
891 struct nfsd4_callback *cb = data;
892 struct nfs4_cb_compound_hdr hdr;
893 int status;
894
895 status = decode_cb_compound4res(xdr, hdr: &hdr);
896 if (unlikely(status))
897 return status;
898
899 status = decode_cb_sequence4res(xdr, cb);
900 if (unlikely(status || cb->cb_seq_status))
901 return status;
902
903 return decode_cb_op_status(xdr, expected: OP_CB_OFFLOAD, status: &cb->cb_status);
904}
905/*
906 * RPC procedure tables
907 */
908#define PROC(proc, call, argtype, restype) \
909[NFSPROC4_CLNT_##proc] = { \
910 .p_proc = NFSPROC4_CB_##call, \
911 .p_encode = nfs4_xdr_enc_##argtype, \
912 .p_decode = nfs4_xdr_dec_##restype, \
913 .p_arglen = NFS4_enc_##argtype##_sz, \
914 .p_replen = NFS4_dec_##restype##_sz, \
915 .p_statidx = NFSPROC4_CB_##call, \
916 .p_name = #proc, \
917}
918
919static const struct rpc_procinfo nfs4_cb_procedures[] = {
920 PROC(CB_NULL, NULL, cb_null, cb_null),
921 PROC(CB_RECALL, COMPOUND, cb_recall, cb_recall),
922#ifdef CONFIG_NFSD_PNFS
923 PROC(CB_LAYOUT, COMPOUND, cb_layout, cb_layout),
924#endif
925 PROC(CB_NOTIFY_LOCK, COMPOUND, cb_notify_lock, cb_notify_lock),
926 PROC(CB_OFFLOAD, COMPOUND, cb_offload, cb_offload),
927 PROC(CB_RECALL_ANY, COMPOUND, cb_recall_any, cb_recall_any),
928 PROC(CB_GETATTR, COMPOUND, cb_getattr, cb_getattr),
929};
930
931static unsigned int nfs4_cb_counts[ARRAY_SIZE(nfs4_cb_procedures)];
932static const struct rpc_version nfs_cb_version4 = {
933/*
934 * Note on the callback rpc program version number: despite language in rfc
935 * 5661 section 18.36.3 requiring servers to use 4 in this field, the
936 * official xdr descriptions for both 4.0 and 4.1 specify version 1, and
937 * in practice that appears to be what implementations use. The section
938 * 18.36.3 language is expected to be fixed in an erratum.
939 */
940 .number = 1,
941 .nrprocs = ARRAY_SIZE(nfs4_cb_procedures),
942 .procs = nfs4_cb_procedures,
943 .counts = nfs4_cb_counts,
944};
945
946static const struct rpc_version *nfs_cb_version[2] = {
947 [1] = &nfs_cb_version4,
948};
949
950static const struct rpc_program cb_program;
951
952static struct rpc_stat cb_stats = {
953 .program = &cb_program
954};
955
956#define NFS4_CALLBACK 0x40000000
957static const struct rpc_program cb_program = {
958 .name = "nfs4_cb",
959 .number = NFS4_CALLBACK,
960 .nrvers = ARRAY_SIZE(nfs_cb_version),
961 .version = nfs_cb_version,
962 .stats = &cb_stats,
963 .pipe_dir_name = "nfsd4_cb",
964};
965
966static int max_cb_time(struct net *net)
967{
968 struct nfsd_net *nn = net_generic(net, id: nfsd_net_id);
969
970 /*
971 * nfsd4_lease is set to at most one hour in __nfsd4_write_time,
972 * so we can use 32-bit math on it. Warn if that assumption
973 * ever stops being true.
974 */
975 if (WARN_ON_ONCE(nn->nfsd4_lease > 3600))
976 return 360 * HZ;
977
978 return max(((u32)nn->nfsd4_lease)/10, 1u) * HZ;
979}
980
981static struct workqueue_struct *callback_wq;
982
983static bool nfsd4_queue_cb(struct nfsd4_callback *cb)
984{
985 trace_nfsd_cb_queue(clp: cb->cb_clp, cb);
986 return queue_delayed_work(wq: callback_wq, dwork: &cb->cb_work, delay: 0);
987}
988
989static void nfsd4_queue_cb_delayed(struct nfsd4_callback *cb,
990 unsigned long msecs)
991{
992 trace_nfsd_cb_queue(clp: cb->cb_clp, cb);
993 queue_delayed_work(wq: callback_wq, dwork: &cb->cb_work,
994 delay: msecs_to_jiffies(m: msecs));
995}
996
997static void nfsd41_cb_inflight_begin(struct nfs4_client *clp)
998{
999 atomic_inc(v: &clp->cl_cb_inflight);
1000}
1001
1002static void nfsd41_cb_inflight_end(struct nfs4_client *clp)
1003{
1004
1005 if (atomic_dec_and_test(v: &clp->cl_cb_inflight))
1006 wake_up_var(var: &clp->cl_cb_inflight);
1007}
1008
1009static void nfsd41_cb_inflight_wait_complete(struct nfs4_client *clp)
1010{
1011 wait_var_event(&clp->cl_cb_inflight,
1012 !atomic_read(&clp->cl_cb_inflight));
1013}
1014
1015static const struct cred *get_backchannel_cred(struct nfs4_client *clp, struct rpc_clnt *client, struct nfsd4_session *ses)
1016{
1017 if (clp->cl_minorversion == 0) {
1018 client->cl_principal = clp->cl_cred.cr_targ_princ ?
1019 clp->cl_cred.cr_targ_princ : "nfs";
1020
1021 return get_cred(cred: rpc_machine_cred());
1022 } else {
1023 struct cred *kcred;
1024
1025 kcred = prepare_kernel_cred(&init_task);
1026 if (!kcred)
1027 return NULL;
1028
1029 kcred->fsuid = ses->se_cb_sec.uid;
1030 kcred->fsgid = ses->se_cb_sec.gid;
1031 return kcred;
1032 }
1033}
1034
1035static int setup_callback_client(struct nfs4_client *clp, struct nfs4_cb_conn *conn, struct nfsd4_session *ses)
1036{
1037 int maxtime = max_cb_time(net: clp->net);
1038 struct rpc_timeout timeparms = {
1039 .to_initval = maxtime,
1040 .to_retries = 0,
1041 .to_maxval = maxtime,
1042 };
1043 struct rpc_create_args args = {
1044 .net = clp->net,
1045 .address = (struct sockaddr *) &conn->cb_addr,
1046 .addrsize = conn->cb_addrlen,
1047 .saddress = (struct sockaddr *) &conn->cb_saddr,
1048 .timeout = &timeparms,
1049 .program = &cb_program,
1050 .version = 1,
1051 .flags = (RPC_CLNT_CREATE_NOPING | RPC_CLNT_CREATE_QUIET),
1052 .cred = current_cred(),
1053 };
1054 struct rpc_clnt *client;
1055 const struct cred *cred;
1056
1057 if (clp->cl_minorversion == 0) {
1058 if (!clp->cl_cred.cr_principal &&
1059 (clp->cl_cred.cr_flavor >= RPC_AUTH_GSS_KRB5)) {
1060 trace_nfsd_cb_setup_err(clp, error: -EINVAL);
1061 return -EINVAL;
1062 }
1063 args.client_name = clp->cl_cred.cr_principal;
1064 args.prognumber = conn->cb_prog;
1065 args.protocol = XPRT_TRANSPORT_TCP;
1066 args.authflavor = clp->cl_cred.cr_flavor;
1067 clp->cl_cb_ident = conn->cb_ident;
1068 } else {
1069 if (!conn->cb_xprt)
1070 return -EINVAL;
1071 clp->cl_cb_session = ses;
1072 args.bc_xprt = conn->cb_xprt;
1073 args.prognumber = clp->cl_cb_session->se_cb_prog;
1074 args.protocol = conn->cb_xprt->xpt_class->xcl_ident |
1075 XPRT_TRANSPORT_BC;
1076 args.authflavor = ses->se_cb_sec.flavor;
1077 }
1078 /* Create RPC client */
1079 client = rpc_create(args: &args);
1080 if (IS_ERR(ptr: client)) {
1081 trace_nfsd_cb_setup_err(clp, error: PTR_ERR(ptr: client));
1082 return PTR_ERR(ptr: client);
1083 }
1084 cred = get_backchannel_cred(clp, client, ses);
1085 if (!cred) {
1086 trace_nfsd_cb_setup_err(clp, error: -ENOMEM);
1087 rpc_shutdown_client(client);
1088 return -ENOMEM;
1089 }
1090
1091 if (clp->cl_minorversion != 0)
1092 clp->cl_cb_conn.cb_xprt = conn->cb_xprt;
1093 clp->cl_cb_client = client;
1094 clp->cl_cb_cred = cred;
1095 rcu_read_lock();
1096 trace_nfsd_cb_setup(clp, netid: rpc_peeraddr2str(client, RPC_DISPLAY_NETID),
1097 authflavor: args.authflavor);
1098 rcu_read_unlock();
1099 return 0;
1100}
1101
1102static void nfsd4_mark_cb_state(struct nfs4_client *clp, int newstate)
1103{
1104 if (clp->cl_cb_state != newstate) {
1105 clp->cl_cb_state = newstate;
1106 trace_nfsd_cb_new_state(clp);
1107 }
1108}
1109
1110static void nfsd4_mark_cb_down(struct nfs4_client *clp)
1111{
1112 if (test_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags))
1113 return;
1114 nfsd4_mark_cb_state(clp, NFSD4_CB_DOWN);
1115}
1116
1117static void nfsd4_mark_cb_fault(struct nfs4_client *clp)
1118{
1119 if (test_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags))
1120 return;
1121 nfsd4_mark_cb_state(clp, NFSD4_CB_FAULT);
1122}
1123
1124static void nfsd4_cb_probe_done(struct rpc_task *task, void *calldata)
1125{
1126 struct nfs4_client *clp = container_of(calldata, struct nfs4_client, cl_cb_null);
1127
1128 if (task->tk_status)
1129 nfsd4_mark_cb_down(clp);
1130 else
1131 nfsd4_mark_cb_state(clp, NFSD4_CB_UP);
1132}
1133
1134static void nfsd4_cb_probe_release(void *calldata)
1135{
1136 struct nfs4_client *clp = container_of(calldata, struct nfs4_client, cl_cb_null);
1137
1138 nfsd41_cb_inflight_end(clp);
1139
1140}
1141
1142static const struct rpc_call_ops nfsd4_cb_probe_ops = {
1143 /* XXX: release method to ensure we set the cb channel down if
1144 * necessary on early failure? */
1145 .rpc_call_done = nfsd4_cb_probe_done,
1146 .rpc_release = nfsd4_cb_probe_release,
1147};
1148
1149/*
1150 * Poke the callback thread to process any updates to the callback
1151 * parameters, and send a null probe.
1152 */
1153void nfsd4_probe_callback(struct nfs4_client *clp)
1154{
1155 trace_nfsd_cb_probe(clp);
1156 nfsd4_mark_cb_state(clp, NFSD4_CB_UNKNOWN);
1157 set_bit(NFSD4_CLIENT_CB_UPDATE, addr: &clp->cl_flags);
1158 nfsd4_run_cb(cb: &clp->cl_cb_null);
1159}
1160
1161void nfsd4_probe_callback_sync(struct nfs4_client *clp)
1162{
1163 nfsd4_probe_callback(clp);
1164 flush_workqueue(callback_wq);
1165}
1166
1167void nfsd4_change_callback(struct nfs4_client *clp, struct nfs4_cb_conn *conn)
1168{
1169 nfsd4_mark_cb_state(clp, NFSD4_CB_UNKNOWN);
1170 spin_lock(lock: &clp->cl_lock);
1171 memcpy(&clp->cl_cb_conn, conn, sizeof(struct nfs4_cb_conn));
1172 spin_unlock(lock: &clp->cl_lock);
1173}
1174
1175/*
1176 * There's currently a single callback channel slot.
1177 * If the slot is available, then mark it busy. Otherwise, set the
1178 * thread for sleeping on the callback RPC wait queue.
1179 */
1180static bool nfsd41_cb_get_slot(struct nfsd4_callback *cb, struct rpc_task *task)
1181{
1182 struct nfs4_client *clp = cb->cb_clp;
1183
1184 if (!cb->cb_holds_slot &&
1185 test_and_set_bit(nr: 0, addr: &clp->cl_cb_slot_busy) != 0) {
1186 rpc_sleep_on(&clp->cl_cb_waitq, task, NULL);
1187 /* Race breaker */
1188 if (test_and_set_bit(nr: 0, addr: &clp->cl_cb_slot_busy) != 0) {
1189 dprintk("%s slot is busy\n", __func__);
1190 return false;
1191 }
1192 rpc_wake_up_queued_task(&clp->cl_cb_waitq, task);
1193 }
1194 cb->cb_holds_slot = true;
1195 return true;
1196}
1197
1198static void nfsd41_cb_release_slot(struct nfsd4_callback *cb)
1199{
1200 struct nfs4_client *clp = cb->cb_clp;
1201
1202 if (cb->cb_holds_slot) {
1203 cb->cb_holds_slot = false;
1204 clear_bit(nr: 0, addr: &clp->cl_cb_slot_busy);
1205 rpc_wake_up_next(&clp->cl_cb_waitq);
1206 }
1207}
1208
1209static void nfsd41_destroy_cb(struct nfsd4_callback *cb)
1210{
1211 struct nfs4_client *clp = cb->cb_clp;
1212
1213 trace_nfsd_cb_destroy(clp, cb);
1214 nfsd41_cb_release_slot(cb);
1215 if (cb->cb_ops && cb->cb_ops->release)
1216 cb->cb_ops->release(cb);
1217 nfsd41_cb_inflight_end(clp);
1218}
1219
1220/*
1221 * TODO: cb_sequence should support referring call lists, cachethis, multiple
1222 * slots, and mark callback channel down on communication errors.
1223 */
1224static void nfsd4_cb_prepare(struct rpc_task *task, void *calldata)
1225{
1226 struct nfsd4_callback *cb = calldata;
1227 struct nfs4_client *clp = cb->cb_clp;
1228 u32 minorversion = clp->cl_minorversion;
1229
1230 /*
1231 * cb_seq_status is only set in decode_cb_sequence4res,
1232 * and so will remain 1 if an rpc level failure occurs.
1233 */
1234 cb->cb_seq_status = 1;
1235 cb->cb_status = 0;
1236 if (minorversion && !nfsd41_cb_get_slot(cb, task))
1237 return;
1238 rpc_call_start(task);
1239}
1240
1241static bool nfsd4_cb_sequence_done(struct rpc_task *task, struct nfsd4_callback *cb)
1242{
1243 struct nfs4_client *clp = cb->cb_clp;
1244 struct nfsd4_session *session = clp->cl_cb_session;
1245 bool ret = true;
1246
1247 if (!clp->cl_minorversion) {
1248 /*
1249 * If the backchannel connection was shut down while this
1250 * task was queued, we need to resubmit it after setting up
1251 * a new backchannel connection.
1252 *
1253 * Note that if we lost our callback connection permanently
1254 * the submission code will error out, so we don't need to
1255 * handle that case here.
1256 */
1257 if (RPC_SIGNALLED(task))
1258 goto need_restart;
1259
1260 return true;
1261 }
1262
1263 if (!cb->cb_holds_slot)
1264 goto need_restart;
1265
1266 /* This is the operation status code for CB_SEQUENCE */
1267 trace_nfsd_cb_seq_status(task, cb);
1268 switch (cb->cb_seq_status) {
1269 case 0:
1270 /*
1271 * No need for lock, access serialized in nfsd4_cb_prepare
1272 *
1273 * RFC5661 20.9.3
1274 * If CB_SEQUENCE returns an error, then the state of the slot
1275 * (sequence ID, cached reply) MUST NOT change.
1276 */
1277 ++session->se_cb_seq_nr;
1278 break;
1279 case -ESERVERFAULT:
1280 ++session->se_cb_seq_nr;
1281 nfsd4_mark_cb_fault(clp: cb->cb_clp);
1282 ret = false;
1283 break;
1284 case 1:
1285 /*
1286 * cb_seq_status remains 1 if an RPC Reply was never
1287 * received. NFSD can't know if the client processed
1288 * the CB_SEQUENCE operation. Ask the client to send a
1289 * DESTROY_SESSION to recover.
1290 */
1291 fallthrough;
1292 case -NFS4ERR_BADSESSION:
1293 nfsd4_mark_cb_fault(clp: cb->cb_clp);
1294 ret = false;
1295 goto need_restart;
1296 case -NFS4ERR_DELAY:
1297 cb->cb_seq_status = 1;
1298 if (!rpc_restart_call(task))
1299 goto out;
1300
1301 rpc_delay(task, 2 * HZ);
1302 return false;
1303 case -NFS4ERR_BADSLOT:
1304 goto retry_nowait;
1305 case -NFS4ERR_SEQ_MISORDERED:
1306 if (session->se_cb_seq_nr != 1) {
1307 session->se_cb_seq_nr = 1;
1308 goto retry_nowait;
1309 }
1310 break;
1311 default:
1312 nfsd4_mark_cb_fault(clp: cb->cb_clp);
1313 }
1314 nfsd41_cb_release_slot(cb);
1315
1316 trace_nfsd_cb_free_slot(task, cb);
1317
1318 if (RPC_SIGNALLED(task))
1319 goto need_restart;
1320out:
1321 return ret;
1322retry_nowait:
1323 if (rpc_restart_call_prepare(task))
1324 ret = false;
1325 goto out;
1326need_restart:
1327 if (!test_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags)) {
1328 trace_nfsd_cb_restart(clp, cb);
1329 task->tk_status = 0;
1330 cb->cb_need_restart = true;
1331 }
1332 return false;
1333}
1334
1335static void nfsd4_cb_done(struct rpc_task *task, void *calldata)
1336{
1337 struct nfsd4_callback *cb = calldata;
1338 struct nfs4_client *clp = cb->cb_clp;
1339
1340 if (!nfsd4_cb_sequence_done(task, cb))
1341 return;
1342
1343 if (cb->cb_status) {
1344 WARN_ON_ONCE(task->tk_status);
1345 task->tk_status = cb->cb_status;
1346 }
1347
1348 switch (cb->cb_ops->done(cb, task)) {
1349 case 0:
1350 task->tk_status = 0;
1351 rpc_restart_call_prepare(task);
1352 return;
1353 case 1:
1354 switch (task->tk_status) {
1355 case -EIO:
1356 case -ETIMEDOUT:
1357 case -EACCES:
1358 nfsd4_mark_cb_down(clp);
1359 }
1360 break;
1361 default:
1362 BUG();
1363 }
1364}
1365
1366static void nfsd4_cb_release(void *calldata)
1367{
1368 struct nfsd4_callback *cb = calldata;
1369
1370 if (cb->cb_need_restart)
1371 nfsd4_queue_cb(cb);
1372 else
1373 nfsd41_destroy_cb(cb);
1374
1375}
1376
1377static const struct rpc_call_ops nfsd4_cb_ops = {
1378 .rpc_call_prepare = nfsd4_cb_prepare,
1379 .rpc_call_done = nfsd4_cb_done,
1380 .rpc_release = nfsd4_cb_release,
1381};
1382
1383int nfsd4_create_callback_queue(void)
1384{
1385 callback_wq = alloc_ordered_workqueue("nfsd4_callbacks", 0);
1386 if (!callback_wq)
1387 return -ENOMEM;
1388 return 0;
1389}
1390
1391void nfsd4_destroy_callback_queue(void)
1392{
1393 destroy_workqueue(wq: callback_wq);
1394}
1395
1396/* must be called under the state lock */
1397void nfsd4_shutdown_callback(struct nfs4_client *clp)
1398{
1399 if (clp->cl_cb_state != NFSD4_CB_UNKNOWN)
1400 trace_nfsd_cb_shutdown(clp);
1401
1402 set_bit(NFSD4_CLIENT_CB_KILL, addr: &clp->cl_flags);
1403 /*
1404 * Note this won't actually result in a null callback;
1405 * instead, nfsd4_run_cb_null() will detect the killed
1406 * client, destroy the rpc client, and stop:
1407 */
1408 nfsd4_run_cb(cb: &clp->cl_cb_null);
1409 flush_workqueue(callback_wq);
1410 nfsd41_cb_inflight_wait_complete(clp);
1411}
1412
1413static struct nfsd4_conn * __nfsd4_find_backchannel(struct nfs4_client *clp)
1414{
1415 struct nfsd4_session *s;
1416 struct nfsd4_conn *c;
1417
1418 lockdep_assert_held(&clp->cl_lock);
1419
1420 list_for_each_entry(s, &clp->cl_sessions, se_perclnt) {
1421 list_for_each_entry(c, &s->se_conns, cn_persession) {
1422 if (c->cn_flags & NFS4_CDFC4_BACK)
1423 return c;
1424 }
1425 }
1426 return NULL;
1427}
1428
1429/*
1430 * Note there isn't a lot of locking in this code; instead we depend on
1431 * the fact that it is run from the callback_wq, which won't run two
1432 * work items at once. So, for example, callback_wq handles all access
1433 * of cl_cb_client and all calls to rpc_create or rpc_shutdown_client.
1434 */
1435static void nfsd4_process_cb_update(struct nfsd4_callback *cb)
1436{
1437 struct nfs4_cb_conn conn;
1438 struct nfs4_client *clp = cb->cb_clp;
1439 struct nfsd4_session *ses = NULL;
1440 struct nfsd4_conn *c;
1441 int err;
1442
1443 trace_nfsd_cb_bc_update(clp, cb);
1444
1445 /*
1446 * This is either an update, or the client dying; in either case,
1447 * kill the old client:
1448 */
1449 if (clp->cl_cb_client) {
1450 trace_nfsd_cb_bc_shutdown(clp, cb);
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
1463 spin_lock(lock: &clp->cl_lock);
1464 /*
1465 * Only serialized callback code is allowed to clear these
1466 * flags; main nfsd code can only set them:
1467 */
1468 WARN_ON(!(clp->cl_flags & NFSD4_CLIENT_CB_FLAG_MASK));
1469 clear_bit(NFSD4_CLIENT_CB_UPDATE, addr: &clp->cl_flags);
1470
1471 memcpy(&conn, &cb->cb_clp->cl_cb_conn, sizeof(struct nfs4_cb_conn));
1472 c = __nfsd4_find_backchannel(clp);
1473 if (c) {
1474 svc_xprt_get(xprt: c->cn_xprt);
1475 conn.cb_xprt = c->cn_xprt;
1476 ses = c->cn_session;
1477 }
1478 spin_unlock(lock: &clp->cl_lock);
1479
1480 err = setup_callback_client(clp, conn: &conn, ses);
1481 if (err) {
1482 nfsd4_mark_cb_down(clp);
1483 if (c)
1484 svc_xprt_put(xprt: c->cn_xprt);
1485 return;
1486 }
1487}
1488
1489static void
1490nfsd4_run_cb_work(struct work_struct *work)
1491{
1492 struct nfsd4_callback *cb =
1493 container_of(work, struct nfsd4_callback, cb_work.work);
1494 struct nfs4_client *clp = cb->cb_clp;
1495 struct rpc_clnt *clnt;
1496 int flags;
1497
1498 trace_nfsd_cb_start(clp);
1499
1500 if (clp->cl_flags & NFSD4_CLIENT_CB_FLAG_MASK)
1501 nfsd4_process_cb_update(cb);
1502
1503 clnt = clp->cl_cb_client;
1504 if (!clnt) {
1505 if (test_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags))
1506 nfsd41_destroy_cb(cb);
1507 else {
1508 /*
1509 * XXX: Ideally, we could wait for the client to
1510 * reconnect, but I haven't figured out how
1511 * to do that yet.
1512 */
1513 nfsd4_queue_cb_delayed(cb, msecs: 25);
1514 }
1515 return;
1516 }
1517
1518 /*
1519 * Don't send probe messages for 4.1 or later.
1520 */
1521 if (!cb->cb_ops && clp->cl_minorversion) {
1522 nfsd4_mark_cb_state(clp, NFSD4_CB_UP);
1523 nfsd41_destroy_cb(cb);
1524 return;
1525 }
1526
1527 if (cb->cb_need_restart) {
1528 cb->cb_need_restart = false;
1529 } else {
1530 if (cb->cb_ops && cb->cb_ops->prepare)
1531 cb->cb_ops->prepare(cb);
1532 }
1533 cb->cb_msg.rpc_cred = clp->cl_cb_cred;
1534 flags = clp->cl_minorversion ? RPC_TASK_NOCONNECT : RPC_TASK_SOFTCONN;
1535 rpc_call_async(clnt, msg: &cb->cb_msg, RPC_TASK_SOFT | flags,
1536 tk_ops: cb->cb_ops ? &nfsd4_cb_ops : &nfsd4_cb_probe_ops, calldata: cb);
1537}
1538
1539void nfsd4_init_cb(struct nfsd4_callback *cb, struct nfs4_client *clp,
1540 const struct nfsd4_callback_ops *ops, enum nfsd4_cb_op op)
1541{
1542 cb->cb_clp = clp;
1543 cb->cb_msg.rpc_proc = &nfs4_cb_procedures[op];
1544 cb->cb_msg.rpc_argp = cb;
1545 cb->cb_msg.rpc_resp = cb;
1546 cb->cb_ops = ops;
1547 INIT_DELAYED_WORK(&cb->cb_work, nfsd4_run_cb_work);
1548 cb->cb_status = 0;
1549 cb->cb_need_restart = false;
1550 cb->cb_holds_slot = false;
1551}
1552
1553/**
1554 * nfsd4_run_cb - queue up a callback job to run
1555 * @cb: callback to queue
1556 *
1557 * Kick off a callback to do its thing. Returns false if it was already
1558 * on a queue, true otherwise.
1559 */
1560bool nfsd4_run_cb(struct nfsd4_callback *cb)
1561{
1562 struct nfs4_client *clp = cb->cb_clp;
1563 bool queued;
1564
1565 nfsd41_cb_inflight_begin(clp);
1566 queued = nfsd4_queue_cb(cb);
1567 if (!queued)
1568 nfsd41_cb_inflight_end(clp);
1569 return queued;
1570}
1571

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