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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 "xdr4cb.h"
42
43#define NFSDDBG_FACILITY NFSDDBG_PROC
44
45static void nfsd4_mark_cb_fault(struct nfs4_client *, int reason);
46
47#define NFSPROC4_CB_NULL 0
48#define NFSPROC4_CB_COMPOUND 1
49
50/* Index of predefined Linux callback client operations */
51
52struct nfs4_cb_compound_hdr {
53 /* args */
54 u32 ident; /* minorversion 0 only */
55 u32 nops;
56 __be32 *nops_p;
57 u32 minorversion;
58 /* res */
59 int status;
60};
61
62/*
63 * Handle decode buffer overflows out-of-line.
64 */
65static void print_overflow_msg(const char *func, const struct xdr_stream *xdr)
66{
67 dprintk("NFS: %s prematurely hit the end of our receive buffer. "
68 "Remaining buffer length is %tu words.\n",
69 func, xdr->end - xdr->p);
70}
71
72static __be32 *xdr_encode_empty_array(__be32 *p)
73{
74 *p++ = xdr_zero;
75 return p;
76}
77
78/*
79 * Encode/decode NFSv4 CB basic data types
80 *
81 * Basic NFSv4 callback data types are defined in section 15 of RFC
82 * 3530: "Network File System (NFS) version 4 Protocol" and section
83 * 20 of RFC 5661: "Network File System (NFS) Version 4 Minor Version
84 * 1 Protocol"
85 */
86
87/*
88 * nfs_cb_opnum4
89 *
90 * enum nfs_cb_opnum4 {
91 * OP_CB_GETATTR = 3,
92 * ...
93 * };
94 */
95enum nfs_cb_opnum4 {
96 OP_CB_GETATTR = 3,
97 OP_CB_RECALL = 4,
98 OP_CB_LAYOUTRECALL = 5,
99 OP_CB_NOTIFY = 6,
100 OP_CB_PUSH_DELEG = 7,
101 OP_CB_RECALL_ANY = 8,
102 OP_CB_RECALLABLE_OBJ_AVAIL = 9,
103 OP_CB_RECALL_SLOT = 10,
104 OP_CB_SEQUENCE = 11,
105 OP_CB_WANTS_CANCELLED = 12,
106 OP_CB_NOTIFY_LOCK = 13,
107 OP_CB_NOTIFY_DEVICEID = 14,
108 OP_CB_ILLEGAL = 10044
109};
110
111static void encode_nfs_cb_opnum4(struct xdr_stream *xdr, enum nfs_cb_opnum4 op)
112{
113 __be32 *p;
114
115 p = xdr_reserve_space(xdr, 4);
116 *p = cpu_to_be32(op);
117}
118
119/*
120 * nfs_fh4
121 *
122 * typedef opaque nfs_fh4<NFS4_FHSIZE>;
123 */
124static void encode_nfs_fh4(struct xdr_stream *xdr, const struct knfsd_fh *fh)
125{
126 u32 length = fh->fh_size;
127 __be32 *p;
128
129 BUG_ON(length > NFS4_FHSIZE);
130 p = xdr_reserve_space(xdr, 4 + length);
131 xdr_encode_opaque(p, &fh->fh_base, length);
132}
133
134/*
135 * stateid4
136 *
137 * struct stateid4 {
138 * uint32_t seqid;
139 * opaque other[12];
140 * };
141 */
142static void encode_stateid4(struct xdr_stream *xdr, const stateid_t *sid)
143{
144 __be32 *p;
145
146 p = xdr_reserve_space(xdr, NFS4_STATEID_SIZE);
147 *p++ = cpu_to_be32(sid->si_generation);
148 xdr_encode_opaque_fixed(p, &sid->si_opaque, NFS4_STATEID_OTHER_SIZE);
149}
150
151/*
152 * sessionid4
153 *
154 * typedef opaque sessionid4[NFS4_SESSIONID_SIZE];
155 */
156static void encode_sessionid4(struct xdr_stream *xdr,
157 const struct nfsd4_session *session)
158{
159 __be32 *p;
160
161 p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN);
162 xdr_encode_opaque_fixed(p, session->se_sessionid.data,
163 NFS4_MAX_SESSIONID_LEN);
164}
165
166/*
167 * nfsstat4
168 */
169static const struct {
170 int stat;
171 int errno;
172} nfs_cb_errtbl[] = {
173 { NFS4_OK, 0 },
174 { NFS4ERR_PERM, -EPERM },
175 { NFS4ERR_NOENT, -ENOENT },
176 { NFS4ERR_IO, -EIO },
177 { NFS4ERR_NXIO, -ENXIO },
178 { NFS4ERR_ACCESS, -EACCES },
179 { NFS4ERR_EXIST, -EEXIST },
180 { NFS4ERR_XDEV, -EXDEV },
181 { NFS4ERR_NOTDIR, -ENOTDIR },
182 { NFS4ERR_ISDIR, -EISDIR },
183 { NFS4ERR_INVAL, -EINVAL },
184 { NFS4ERR_FBIG, -EFBIG },
185 { NFS4ERR_NOSPC, -ENOSPC },
186 { NFS4ERR_ROFS, -EROFS },
187 { NFS4ERR_MLINK, -EMLINK },
188 { NFS4ERR_NAMETOOLONG, -ENAMETOOLONG },
189 { NFS4ERR_NOTEMPTY, -ENOTEMPTY },
190 { NFS4ERR_DQUOT, -EDQUOT },
191 { NFS4ERR_STALE, -ESTALE },
192 { NFS4ERR_BADHANDLE, -EBADHANDLE },
193 { NFS4ERR_BAD_COOKIE, -EBADCOOKIE },
194 { NFS4ERR_NOTSUPP, -ENOTSUPP },
195 { NFS4ERR_TOOSMALL, -ETOOSMALL },
196 { NFS4ERR_SERVERFAULT, -ESERVERFAULT },
197 { NFS4ERR_BADTYPE, -EBADTYPE },
198 { NFS4ERR_LOCKED, -EAGAIN },
199 { NFS4ERR_RESOURCE, -EREMOTEIO },
200 { NFS4ERR_SYMLINK, -ELOOP },
201 { NFS4ERR_OP_ILLEGAL, -EOPNOTSUPP },
202 { NFS4ERR_DEADLOCK, -EDEADLK },
203 { -1, -EIO }
204};
205
206/*
207 * If we cannot translate the error, the recovery routines should
208 * handle it.
209 *
210 * Note: remaining NFSv4 error codes have values > 10000, so should
211 * not conflict with native Linux error codes.
212 */
213static int nfs_cb_stat_to_errno(int status)
214{
215 int i;
216
217 for (i = 0; nfs_cb_errtbl[i].stat != -1; i++) {
218 if (nfs_cb_errtbl[i].stat == status)
219 return nfs_cb_errtbl[i].errno;
220 }
221
222 dprintk("NFSD: Unrecognized NFS CB status value: %u\n", status);
223 return -status;
224}
225
226static int decode_cb_op_status(struct xdr_stream *xdr, enum nfs_opnum4 expected,
227 int *status)
228{
229 __be32 *p;
230 u32 op;
231
232 p = xdr_inline_decode(xdr, 4 + 4);
233 if (unlikely(p == NULL))
234 goto out_overflow;
235 op = be32_to_cpup(p++);
236 if (unlikely(op != expected))
237 goto out_unexpected;
238 *status = nfs_cb_stat_to_errno(be32_to_cpup(p));
239 return 0;
240out_overflow:
241 print_overflow_msg(__func__, xdr);
242 return -EIO;
243out_unexpected:
244 dprintk("NFSD: Callback server returned operation %d but "
245 "we issued a request for %d\n", op, expected);
246 return -EIO;
247}
248
249/*
250 * CB_COMPOUND4args
251 *
252 * struct CB_COMPOUND4args {
253 * utf8str_cs tag;
254 * uint32_t minorversion;
255 * uint32_t callback_ident;
256 * nfs_cb_argop4 argarray<>;
257 * };
258*/
259static void encode_cb_compound4args(struct xdr_stream *xdr,
260 struct nfs4_cb_compound_hdr *hdr)
261{
262 __be32 * p;
263
264 p = xdr_reserve_space(xdr, 4 + 4 + 4 + 4);
265 p = xdr_encode_empty_array(p); /* empty tag */
266 *p++ = cpu_to_be32(hdr->minorversion);
267 *p++ = cpu_to_be32(hdr->ident);
268
269 hdr->nops_p = p;
270 *p = cpu_to_be32(hdr->nops); /* argarray element count */
271}
272
273/*
274 * Update argarray element count
275 */
276static void encode_cb_nops(struct nfs4_cb_compound_hdr *hdr)
277{
278 BUG_ON(hdr->nops > NFS4_MAX_BACK_CHANNEL_OPS);
279 *hdr->nops_p = cpu_to_be32(hdr->nops);
280}
281
282/*
283 * CB_COMPOUND4res
284 *
285 * struct CB_COMPOUND4res {
286 * nfsstat4 status;
287 * utf8str_cs tag;
288 * nfs_cb_resop4 resarray<>;
289 * };
290 */
291static int decode_cb_compound4res(struct xdr_stream *xdr,
292 struct nfs4_cb_compound_hdr *hdr)
293{
294 u32 length;
295 __be32 *p;
296
297 p = xdr_inline_decode(xdr, 4 + 4);
298 if (unlikely(p == NULL))
299 goto out_overflow;
300 hdr->status = be32_to_cpup(p++);
301 /* Ignore the tag */
302 length = be32_to_cpup(p++);
303 p = xdr_inline_decode(xdr, length + 4);
304 if (unlikely(p == NULL))
305 goto out_overflow;
306 hdr->nops = be32_to_cpup(p);
307 return 0;
308out_overflow:
309 print_overflow_msg(__func__, xdr);
310 return -EIO;
311}
312
313/*
314 * CB_RECALL4args
315 *
316 * struct CB_RECALL4args {
317 * stateid4 stateid;
318 * bool truncate;
319 * nfs_fh4 fh;
320 * };
321 */
322static void encode_cb_recall4args(struct xdr_stream *xdr,
323 const struct nfs4_delegation *dp,
324 struct nfs4_cb_compound_hdr *hdr)
325{
326 __be32 *p;
327
328 encode_nfs_cb_opnum4(xdr, OP_CB_RECALL);
329 encode_stateid4(xdr, &dp->dl_stid.sc_stateid);
330
331 p = xdr_reserve_space(xdr, 4);
332 *p++ = xdr_zero; /* truncate */
333
334 encode_nfs_fh4(xdr, &dp->dl_stid.sc_file->fi_fhandle);
335
336 hdr->nops++;
337}
338
339/*
340 * CB_SEQUENCE4args
341 *
342 * struct CB_SEQUENCE4args {
343 * sessionid4 csa_sessionid;
344 * sequenceid4 csa_sequenceid;
345 * slotid4 csa_slotid;
346 * slotid4 csa_highest_slotid;
347 * bool csa_cachethis;
348 * referring_call_list4 csa_referring_call_lists<>;
349 * };
350 */
351static void encode_cb_sequence4args(struct xdr_stream *xdr,
352 const struct nfsd4_callback *cb,
353 struct nfs4_cb_compound_hdr *hdr)
354{
355 struct nfsd4_session *session = cb->cb_clp->cl_cb_session;
356 __be32 *p;
357
358 if (hdr->minorversion == 0)
359 return;
360
361 encode_nfs_cb_opnum4(xdr, OP_CB_SEQUENCE);
362 encode_sessionid4(xdr, session);
363
364 p = xdr_reserve_space(xdr, 4 + 4 + 4 + 4 + 4);
365 *p++ = cpu_to_be32(session->se_cb_seq_nr); /* csa_sequenceid */
366 *p++ = xdr_zero; /* csa_slotid */
367 *p++ = xdr_zero; /* csa_highest_slotid */
368 *p++ = xdr_zero; /* csa_cachethis */
369 xdr_encode_empty_array(p); /* csa_referring_call_lists */
370
371 hdr->nops++;
372}
373
374/*
375 * CB_SEQUENCE4resok
376 *
377 * struct CB_SEQUENCE4resok {
378 * sessionid4 csr_sessionid;
379 * sequenceid4 csr_sequenceid;
380 * slotid4 csr_slotid;
381 * slotid4 csr_highest_slotid;
382 * slotid4 csr_target_highest_slotid;
383 * };
384 *
385 * union CB_SEQUENCE4res switch (nfsstat4 csr_status) {
386 * case NFS4_OK:
387 * CB_SEQUENCE4resok csr_resok4;
388 * default:
389 * void;
390 * };
391 *
392 * Our current back channel implmentation supports a single backchannel
393 * with a single slot.
394 */
395static int decode_cb_sequence4resok(struct xdr_stream *xdr,
396 struct nfsd4_callback *cb)
397{
398 struct nfsd4_session *session = cb->cb_clp->cl_cb_session;
399 struct nfs4_sessionid id;
400 int status;
401 __be32 *p;
402 u32 dummy;
403
404 status = -ESERVERFAULT;
405
406 /*
407 * If the server returns different values for sessionID, slotID or
408 * sequence number, the server is looney tunes.
409 */
410 p = xdr_inline_decode(xdr, NFS4_MAX_SESSIONID_LEN + 4 + 4 + 4 + 4);
411 if (unlikely(p == NULL))
412 goto out_overflow;
413 memcpy(id.data, p, NFS4_MAX_SESSIONID_LEN);
414 if (memcmp(id.data, session->se_sessionid.data,
415 NFS4_MAX_SESSIONID_LEN) != 0) {
416 dprintk("NFS: %s Invalid session id\n", __func__);
417 goto out;
418 }
419 p += XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN);
420
421 dummy = be32_to_cpup(p++);
422 if (dummy != session->se_cb_seq_nr) {
423 dprintk("NFS: %s Invalid sequence number\n", __func__);
424 goto out;
425 }
426
427 dummy = be32_to_cpup(p++);
428 if (dummy != 0) {
429 dprintk("NFS: %s Invalid slotid\n", __func__);
430 goto out;
431 }
432
433 /*
434 * FIXME: process highest slotid and target highest slotid
435 */
436 status = 0;
437out:
438 cb->cb_seq_status = status;
439 return status;
440out_overflow:
441 print_overflow_msg(__func__, xdr);
442 status = -EIO;
443 goto out;
444}
445
446static int decode_cb_sequence4res(struct xdr_stream *xdr,
447 struct nfsd4_callback *cb)
448{
449 int status;
450
451 if (cb->cb_clp->cl_minorversion == 0)
452 return 0;
453
454 status = decode_cb_op_status(xdr, OP_CB_SEQUENCE, &cb->cb_seq_status);
455 if (unlikely(status || cb->cb_seq_status))
456 return status;
457
458 return decode_cb_sequence4resok(xdr, cb);
459}
460
461/*
462 * NFSv4.0 and NFSv4.1 XDR encode functions
463 *
464 * NFSv4.0 callback argument types are defined in section 15 of RFC
465 * 3530: "Network File System (NFS) version 4 Protocol" and section 20
466 * of RFC 5661: "Network File System (NFS) Version 4 Minor Version 1
467 * Protocol".
468 */
469
470/*
471 * NB: Without this zero space reservation, callbacks over krb5p fail
472 */
473static void nfs4_xdr_enc_cb_null(struct rpc_rqst *req, struct xdr_stream *xdr,
474 void *__unused)
475{
476 xdr_reserve_space(xdr, 0);
477}
478
479/*
480 * 20.2. Operation 4: CB_RECALL - Recall a Delegation
481 */
482static void nfs4_xdr_enc_cb_recall(struct rpc_rqst *req, struct xdr_stream *xdr,
483 const struct nfsd4_callback *cb)
484{
485 const struct nfs4_delegation *dp = cb_to_delegation(cb);
486 struct nfs4_cb_compound_hdr hdr = {
487 .ident = cb->cb_clp->cl_cb_ident,
488 .minorversion = cb->cb_clp->cl_minorversion,
489 };
490
491 encode_cb_compound4args(xdr, &hdr);
492 encode_cb_sequence4args(xdr, cb, &hdr);
493 encode_cb_recall4args(xdr, dp, &hdr);
494 encode_cb_nops(&hdr);
495}
496
497
498/*
499 * NFSv4.0 and NFSv4.1 XDR decode functions
500 *
501 * NFSv4.0 callback result types are defined in section 15 of RFC
502 * 3530: "Network File System (NFS) version 4 Protocol" and section 20
503 * of RFC 5661: "Network File System (NFS) Version 4 Minor Version 1
504 * Protocol".
505 */
506
507static int nfs4_xdr_dec_cb_null(struct rpc_rqst *req, struct xdr_stream *xdr,
508 void *__unused)
509{
510 return 0;
511}
512
513/*
514 * 20.2. Operation 4: CB_RECALL - Recall a Delegation
515 */
516static int nfs4_xdr_dec_cb_recall(struct rpc_rqst *rqstp,
517 struct xdr_stream *xdr,
518 struct nfsd4_callback *cb)
519{
520 struct nfs4_cb_compound_hdr hdr;
521 int status;
522
523 status = decode_cb_compound4res(xdr, &hdr);
524 if (unlikely(status))
525 return status;
526
527 if (cb != NULL) {
528 status = decode_cb_sequence4res(xdr, cb);
529 if (unlikely(status || cb->cb_seq_status))
530 return status;
531 }
532
533 return decode_cb_op_status(xdr, OP_CB_RECALL, &cb->cb_status);
534}
535
536#ifdef CONFIG_NFSD_PNFS
537/*
538 * CB_LAYOUTRECALL4args
539 *
540 * struct layoutrecall_file4 {
541 * nfs_fh4 lor_fh;
542 * offset4 lor_offset;
543 * length4 lor_length;
544 * stateid4 lor_stateid;
545 * };
546 *
547 * union layoutrecall4 switch(layoutrecall_type4 lor_recalltype) {
548 * case LAYOUTRECALL4_FILE:
549 * layoutrecall_file4 lor_layout;
550 * case LAYOUTRECALL4_FSID:
551 * fsid4 lor_fsid;
552 * case LAYOUTRECALL4_ALL:
553 * void;
554 * };
555 *
556 * struct CB_LAYOUTRECALL4args {
557 * layouttype4 clora_type;
558 * layoutiomode4 clora_iomode;
559 * bool clora_changed;
560 * layoutrecall4 clora_recall;
561 * };
562 */
563static void encode_cb_layout4args(struct xdr_stream *xdr,
564 const struct nfs4_layout_stateid *ls,
565 struct nfs4_cb_compound_hdr *hdr)
566{
567 __be32 *p;
568
569 BUG_ON(hdr->minorversion == 0);
570
571 p = xdr_reserve_space(xdr, 5 * 4);
572 *p++ = cpu_to_be32(OP_CB_LAYOUTRECALL);
573 *p++ = cpu_to_be32(ls->ls_layout_type);
574 *p++ = cpu_to_be32(IOMODE_ANY);
575 *p++ = cpu_to_be32(1);
576 *p = cpu_to_be32(RETURN_FILE);
577
578 encode_nfs_fh4(xdr, &ls->ls_stid.sc_file->fi_fhandle);
579
580 p = xdr_reserve_space(xdr, 2 * 8);
581 p = xdr_encode_hyper(p, 0);
582 xdr_encode_hyper(p, NFS4_MAX_UINT64);
583
584 encode_stateid4(xdr, &ls->ls_recall_sid);
585
586 hdr->nops++;
587}
588
589static void nfs4_xdr_enc_cb_layout(struct rpc_rqst *req,
590 struct xdr_stream *xdr,
591 const struct nfsd4_callback *cb)
592{
593 const struct nfs4_layout_stateid *ls =
594 container_of(cb, struct nfs4_layout_stateid, ls_recall);
595 struct nfs4_cb_compound_hdr hdr = {
596 .ident = 0,
597 .minorversion = cb->cb_clp->cl_minorversion,
598 };
599
600 encode_cb_compound4args(xdr, &hdr);
601 encode_cb_sequence4args(xdr, cb, &hdr);
602 encode_cb_layout4args(xdr, ls, &hdr);
603 encode_cb_nops(&hdr);
604}
605
606static int nfs4_xdr_dec_cb_layout(struct rpc_rqst *rqstp,
607 struct xdr_stream *xdr,
608 struct nfsd4_callback *cb)
609{
610 struct nfs4_cb_compound_hdr hdr;
611 int status;
612
613 status = decode_cb_compound4res(xdr, &hdr);
614 if (unlikely(status))
615 return status;
616
617 if (cb) {
618 status = decode_cb_sequence4res(xdr, cb);
619 if (unlikely(status || cb->cb_seq_status))
620 return status;
621 }
622 return decode_cb_op_status(xdr, OP_CB_LAYOUTRECALL, &cb->cb_status);
623}
624#endif /* CONFIG_NFSD_PNFS */
625
626static void encode_stateowner(struct xdr_stream *xdr, struct nfs4_stateowner *so)
627{
628 __be32 *p;
629
630 p = xdr_reserve_space(xdr, 8 + 4 + so->so_owner.len);
631 p = xdr_encode_opaque_fixed(p, &so->so_client->cl_clientid, 8);
632 xdr_encode_opaque(p, so->so_owner.data, so->so_owner.len);
633}
634
635static void nfs4_xdr_enc_cb_notify_lock(struct rpc_rqst *req,
636 struct xdr_stream *xdr,
637 const struct nfsd4_callback *cb)
638{
639 const struct nfsd4_blocked_lock *nbl =
640 container_of(cb, struct nfsd4_blocked_lock, nbl_cb);
641 struct nfs4_lockowner *lo = (struct nfs4_lockowner *)nbl->nbl_lock.fl_owner;
642 struct nfs4_cb_compound_hdr hdr = {
643 .ident = 0,
644 .minorversion = cb->cb_clp->cl_minorversion,
645 };
646
647 __be32 *p;
648
649 BUG_ON(hdr.minorversion == 0);
650
651 encode_cb_compound4args(xdr, &hdr);
652 encode_cb_sequence4args(xdr, cb, &hdr);
653
654 p = xdr_reserve_space(xdr, 4);
655 *p = cpu_to_be32(OP_CB_NOTIFY_LOCK);
656 encode_nfs_fh4(xdr, &nbl->nbl_fh);
657 encode_stateowner(xdr, &lo->lo_owner);
658 hdr.nops++;
659
660 encode_cb_nops(&hdr);
661}
662
663static int nfs4_xdr_dec_cb_notify_lock(struct rpc_rqst *rqstp,
664 struct xdr_stream *xdr,
665 struct nfsd4_callback *cb)
666{
667 struct nfs4_cb_compound_hdr hdr;
668 int status;
669
670 status = decode_cb_compound4res(xdr, &hdr);
671 if (unlikely(status))
672 return status;
673
674 if (cb) {
675 status = decode_cb_sequence4res(xdr, cb);
676 if (unlikely(status || cb->cb_seq_status))
677 return status;
678 }
679 return decode_cb_op_status(xdr, OP_CB_NOTIFY_LOCK, &cb->cb_status);
680}
681
682/*
683 * RPC procedure tables
684 */
685#define PROC(proc, call, argtype, restype) \
686[NFSPROC4_CLNT_##proc] = { \
687 .p_proc = NFSPROC4_CB_##call, \
688 .p_encode = (kxdreproc_t)nfs4_xdr_enc_##argtype, \
689 .p_decode = (kxdrdproc_t)nfs4_xdr_dec_##restype, \
690 .p_arglen = NFS4_enc_##argtype##_sz, \
691 .p_replen = NFS4_dec_##restype##_sz, \
692 .p_statidx = NFSPROC4_CB_##call, \
693 .p_name = #proc, \
694}
695
696static struct rpc_procinfo nfs4_cb_procedures[] = {
697 PROC(CB_NULL, NULL, cb_null, cb_null),
698 PROC(CB_RECALL, COMPOUND, cb_recall, cb_recall),
699#ifdef CONFIG_NFSD_PNFS
700 PROC(CB_LAYOUT, COMPOUND, cb_layout, cb_layout),
701#endif
702 PROC(CB_NOTIFY_LOCK, COMPOUND, cb_notify_lock, cb_notify_lock),
703};
704
705static struct rpc_version nfs_cb_version4 = {
706/*
707 * Note on the callback rpc program version number: despite language in rfc
708 * 5661 section 18.36.3 requiring servers to use 4 in this field, the
709 * official xdr descriptions for both 4.0 and 4.1 specify version 1, and
710 * in practice that appears to be what implementations use. The section
711 * 18.36.3 language is expected to be fixed in an erratum.
712 */
713 .number = 1,
714 .nrprocs = ARRAY_SIZE(nfs4_cb_procedures),
715 .procs = nfs4_cb_procedures
716};
717
718static const struct rpc_version *nfs_cb_version[] = {
719 &nfs_cb_version4,
720};
721
722static const struct rpc_program cb_program;
723
724static struct rpc_stat cb_stats = {
725 .program = &cb_program
726};
727
728#define NFS4_CALLBACK 0x40000000
729static const struct rpc_program cb_program = {
730 .name = "nfs4_cb",
731 .number = NFS4_CALLBACK,
732 .nrvers = ARRAY_SIZE(nfs_cb_version),
733 .version = nfs_cb_version,
734 .stats = &cb_stats,
735 .pipe_dir_name = "nfsd4_cb",
736};
737
738static int max_cb_time(struct net *net)
739{
740 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
741 return max(nn->nfsd4_lease/10, (time_t)1) * HZ;
742}
743
744static struct rpc_cred *callback_cred;
745
746int set_callback_cred(void)
747{
748 if (callback_cred)
749 return 0;
750 callback_cred = rpc_lookup_machine_cred("nfs");
751 if (!callback_cred)
752 return -ENOMEM;
753 return 0;
754}
755
756static struct rpc_cred *get_backchannel_cred(struct nfs4_client *clp, struct rpc_clnt *client, struct nfsd4_session *ses)
757{
758 if (clp->cl_minorversion == 0) {
759 return get_rpccred(callback_cred);
760 } else {
761 struct rpc_auth *auth = client->cl_auth;
762 struct auth_cred acred = {};
763
764 acred.uid = ses->se_cb_sec.uid;
765 acred.gid = ses->se_cb_sec.gid;
766 return auth->au_ops->lookup_cred(client->cl_auth, &acred, 0);
767 }
768}
769
770static int setup_callback_client(struct nfs4_client *clp, struct nfs4_cb_conn *conn, struct nfsd4_session *ses)
771{
772 int maxtime = max_cb_time(clp->net);
773 struct rpc_timeout timeparms = {
774 .to_initval = maxtime,
775 .to_retries = 0,
776 .to_maxval = maxtime,
777 };
778 struct rpc_create_args args = {
779 .net = clp->net,
780 .address = (struct sockaddr *) &conn->cb_addr,
781 .addrsize = conn->cb_addrlen,
782 .saddress = (struct sockaddr *) &conn->cb_saddr,
783 .timeout = &timeparms,
784 .program = &cb_program,
785 .version = 0,
786 .flags = (RPC_CLNT_CREATE_NOPING | RPC_CLNT_CREATE_QUIET),
787 };
788 struct rpc_clnt *client;
789 struct rpc_cred *cred;
790
791 if (clp->cl_minorversion == 0) {
792 if (!clp->cl_cred.cr_principal &&
793 (clp->cl_cred.cr_flavor >= RPC_AUTH_GSS_KRB5))
794 return -EINVAL;
795 args.client_name = clp->cl_cred.cr_principal;
796 args.prognumber = conn->cb_prog;
797 args.protocol = XPRT_TRANSPORT_TCP;
798 args.authflavor = clp->cl_cred.cr_flavor;
799 clp->cl_cb_ident = conn->cb_ident;
800 } else {
801 if (!conn->cb_xprt)
802 return -EINVAL;
803 clp->cl_cb_conn.cb_xprt = conn->cb_xprt;
804 clp->cl_cb_session = ses;
805 args.bc_xprt = conn->cb_xprt;
806 args.prognumber = clp->cl_cb_session->se_cb_prog;
807 args.protocol = conn->cb_xprt->xpt_class->xcl_ident |
808 XPRT_TRANSPORT_BC;
809 args.authflavor = ses->se_cb_sec.flavor;
810 }
811 /* Create RPC client */
812 client = rpc_create(&args);
813 if (IS_ERR(client)) {
814 dprintk("NFSD: couldn't create callback client: %ld\n",
815 PTR_ERR(client));
816 return PTR_ERR(client);
817 }
818 cred = get_backchannel_cred(clp, client, ses);
819 if (IS_ERR(cred)) {
820 rpc_shutdown_client(client);
821 return PTR_ERR(cred);
822 }
823 clp->cl_cb_client = client;
824 clp->cl_cb_cred = cred;
825 return 0;
826}
827
828static void warn_no_callback_path(struct nfs4_client *clp, int reason)
829{
830 dprintk("NFSD: warning: no callback path to client %.*s: error %d\n",
831 (int)clp->cl_name.len, clp->cl_name.data, reason);
832}
833
834static void nfsd4_mark_cb_down(struct nfs4_client *clp, int reason)
835{
836 if (test_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags))
837 return;
838 clp->cl_cb_state = NFSD4_CB_DOWN;
839 warn_no_callback_path(clp, reason);
840}
841
842static void nfsd4_mark_cb_fault(struct nfs4_client *clp, int reason)
843{
844 if (test_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags))
845 return;
846 clp->cl_cb_state = NFSD4_CB_FAULT;
847 warn_no_callback_path(clp, reason);
848}
849
850static void nfsd4_cb_probe_done(struct rpc_task *task, void *calldata)
851{
852 struct nfs4_client *clp = container_of(calldata, struct nfs4_client, cl_cb_null);
853
854 if (task->tk_status)
855 nfsd4_mark_cb_down(clp, task->tk_status);
856 else
857 clp->cl_cb_state = NFSD4_CB_UP;
858}
859
860static const struct rpc_call_ops nfsd4_cb_probe_ops = {
861 /* XXX: release method to ensure we set the cb channel down if
862 * necessary on early failure? */
863 .rpc_call_done = nfsd4_cb_probe_done,
864};
865
866static struct workqueue_struct *callback_wq;
867
868/*
869 * Poke the callback thread to process any updates to the callback
870 * parameters, and send a null probe.
871 */
872void nfsd4_probe_callback(struct nfs4_client *clp)
873{
874 clp->cl_cb_state = NFSD4_CB_UNKNOWN;
875 set_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags);
876 nfsd4_run_cb(&clp->cl_cb_null);
877}
878
879void nfsd4_probe_callback_sync(struct nfs4_client *clp)
880{
881 nfsd4_probe_callback(clp);
882 flush_workqueue(callback_wq);
883}
884
885void nfsd4_change_callback(struct nfs4_client *clp, struct nfs4_cb_conn *conn)
886{
887 clp->cl_cb_state = NFSD4_CB_UNKNOWN;
888 spin_lock(&clp->cl_lock);
889 memcpy(&clp->cl_cb_conn, conn, sizeof(struct nfs4_cb_conn));
890 spin_unlock(&clp->cl_lock);
891}
892
893/*
894 * There's currently a single callback channel slot.
895 * If the slot is available, then mark it busy. Otherwise, set the
896 * thread for sleeping on the callback RPC wait queue.
897 */
898static bool nfsd41_cb_get_slot(struct nfs4_client *clp, struct rpc_task *task)
899{
900 if (test_and_set_bit(0, &clp->cl_cb_slot_busy) != 0) {
901 rpc_sleep_on(&clp->cl_cb_waitq, task, NULL);
902 /* Race breaker */
903 if (test_and_set_bit(0, &clp->cl_cb_slot_busy) != 0) {
904 dprintk("%s slot is busy\n", __func__);
905 return false;
906 }
907 rpc_wake_up_queued_task(&clp->cl_cb_waitq, task);
908 }
909 return true;
910}
911
912/*
913 * TODO: cb_sequence should support referring call lists, cachethis, multiple
914 * slots, and mark callback channel down on communication errors.
915 */
916static void nfsd4_cb_prepare(struct rpc_task *task, void *calldata)
917{
918 struct nfsd4_callback *cb = calldata;
919 struct nfs4_client *clp = cb->cb_clp;
920 u32 minorversion = clp->cl_minorversion;
921
922 /*
923 * cb_seq_status is only set in decode_cb_sequence4res,
924 * and so will remain 1 if an rpc level failure occurs.
925 */
926 cb->cb_seq_status = 1;
927 cb->cb_status = 0;
928 if (minorversion) {
929 if (!nfsd41_cb_get_slot(clp, task))
930 return;
931 }
932 rpc_call_start(task);
933}
934
935static bool nfsd4_cb_sequence_done(struct rpc_task *task, struct nfsd4_callback *cb)
936{
937 struct nfs4_client *clp = cb->cb_clp;
938 struct nfsd4_session *session = clp->cl_cb_session;
939 bool ret = true;
940
941 if (!clp->cl_minorversion) {
942 /*
943 * If the backchannel connection was shut down while this
944 * task was queued, we need to resubmit it after setting up
945 * a new backchannel connection.
946 *
947 * Note that if we lost our callback connection permanently
948 * the submission code will error out, so we don't need to
949 * handle that case here.
950 */
951 if (task->tk_flags & RPC_TASK_KILLED)
952 goto need_restart;
953
954 return true;
955 }
956
957 switch (cb->cb_seq_status) {
958 case 0:
959 /*
960 * No need for lock, access serialized in nfsd4_cb_prepare
961 *
962 * RFC5661 20.9.3
963 * If CB_SEQUENCE returns an error, then the state of the slot
964 * (sequence ID, cached reply) MUST NOT change.
965 */
966 ++session->se_cb_seq_nr;
967 break;
968 case -ESERVERFAULT:
969 ++session->se_cb_seq_nr;
970 case 1:
971 case -NFS4ERR_BADSESSION:
972 nfsd4_mark_cb_fault(cb->cb_clp, cb->cb_seq_status);
973 ret = false;
974 break;
975 case -NFS4ERR_DELAY:
976 if (!rpc_restart_call(task))
977 goto out;
978
979 rpc_delay(task, 2 * HZ);
980 return false;
981 case -NFS4ERR_BADSLOT:
982 goto retry_nowait;
983 case -NFS4ERR_SEQ_MISORDERED:
984 if (session->se_cb_seq_nr != 1) {
985 session->se_cb_seq_nr = 1;
986 goto retry_nowait;
987 }
988 break;
989 default:
990 dprintk("%s: unprocessed error %d\n", __func__,
991 cb->cb_seq_status);
992 }
993
994 clear_bit(0, &clp->cl_cb_slot_busy);
995 rpc_wake_up_next(&clp->cl_cb_waitq);
996 dprintk("%s: freed slot, new seqid=%d\n", __func__,
997 clp->cl_cb_session->se_cb_seq_nr);
998
999 if (task->tk_flags & RPC_TASK_KILLED)
1000 goto need_restart;
1001out:
1002 return ret;
1003retry_nowait:
1004 if (rpc_restart_call_prepare(task))
1005 ret = false;
1006 goto out;
1007need_restart:
1008 task->tk_status = 0;
1009 cb->cb_need_restart = true;
1010 return false;
1011}
1012
1013static void nfsd4_cb_done(struct rpc_task *task, void *calldata)
1014{
1015 struct nfsd4_callback *cb = calldata;
1016 struct nfs4_client *clp = cb->cb_clp;
1017
1018 dprintk("%s: minorversion=%d\n", __func__,
1019 clp->cl_minorversion);
1020
1021 if (!nfsd4_cb_sequence_done(task, cb))
1022 return;
1023
1024 if (cb->cb_status) {
1025 WARN_ON_ONCE(task->tk_status);
1026 task->tk_status = cb->cb_status;
1027 }
1028
1029 switch (cb->cb_ops->done(cb, task)) {
1030 case 0:
1031 task->tk_status = 0;
1032 rpc_restart_call_prepare(task);
1033 return;
1034 case 1:
1035 break;
1036 case -1:
1037 /* Network partition? */
1038 nfsd4_mark_cb_down(clp, task->tk_status);
1039 break;
1040 default:
1041 BUG();
1042 }
1043}
1044
1045static void nfsd4_cb_release(void *calldata)
1046{
1047 struct nfsd4_callback *cb = calldata;
1048
1049 if (cb->cb_need_restart)
1050 nfsd4_run_cb(cb);
1051 else
1052 cb->cb_ops->release(cb);
1053
1054}
1055
1056static const struct rpc_call_ops nfsd4_cb_ops = {
1057 .rpc_call_prepare = nfsd4_cb_prepare,
1058 .rpc_call_done = nfsd4_cb_done,
1059 .rpc_release = nfsd4_cb_release,
1060};
1061
1062int nfsd4_create_callback_queue(void)
1063{
1064 callback_wq = alloc_ordered_workqueue("nfsd4_callbacks", 0);
1065 if (!callback_wq)
1066 return -ENOMEM;
1067 return 0;
1068}
1069
1070void nfsd4_destroy_callback_queue(void)
1071{
1072 destroy_workqueue(callback_wq);
1073}
1074
1075/* must be called under the state lock */
1076void nfsd4_shutdown_callback(struct nfs4_client *clp)
1077{
1078 set_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags);
1079 /*
1080 * Note this won't actually result in a null callback;
1081 * instead, nfsd4_run_cb_null() will detect the killed
1082 * client, destroy the rpc client, and stop:
1083 */
1084 nfsd4_run_cb(&clp->cl_cb_null);
1085 flush_workqueue(callback_wq);
1086}
1087
1088/* requires cl_lock: */
1089static struct nfsd4_conn * __nfsd4_find_backchannel(struct nfs4_client *clp)
1090{
1091 struct nfsd4_session *s;
1092 struct nfsd4_conn *c;
1093
1094 list_for_each_entry(s, &clp->cl_sessions, se_perclnt) {
1095 list_for_each_entry(c, &s->se_conns, cn_persession) {
1096 if (c->cn_flags & NFS4_CDFC4_BACK)
1097 return c;
1098 }
1099 }
1100 return NULL;
1101}
1102
1103static void nfsd4_process_cb_update(struct nfsd4_callback *cb)
1104{
1105 struct nfs4_cb_conn conn;
1106 struct nfs4_client *clp = cb->cb_clp;
1107 struct nfsd4_session *ses = NULL;
1108 struct nfsd4_conn *c;
1109 int err;
1110
1111 /*
1112 * This is either an update, or the client dying; in either case,
1113 * kill the old client:
1114 */
1115 if (clp->cl_cb_client) {
1116 rpc_shutdown_client(clp->cl_cb_client);
1117 clp->cl_cb_client = NULL;
1118 put_rpccred(clp->cl_cb_cred);
1119 clp->cl_cb_cred = NULL;
1120 }
1121 if (clp->cl_cb_conn.cb_xprt) {
1122 svc_xprt_put(clp->cl_cb_conn.cb_xprt);
1123 clp->cl_cb_conn.cb_xprt = NULL;
1124 }
1125 if (test_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags))
1126 return;
1127 spin_lock(&clp->cl_lock);
1128 /*
1129 * Only serialized callback code is allowed to clear these
1130 * flags; main nfsd code can only set them:
1131 */
1132 BUG_ON(!(clp->cl_flags & NFSD4_CLIENT_CB_FLAG_MASK));
1133 clear_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags);
1134 memcpy(&conn, &cb->cb_clp->cl_cb_conn, sizeof(struct nfs4_cb_conn));
1135 c = __nfsd4_find_backchannel(clp);
1136 if (c) {
1137 svc_xprt_get(c->cn_xprt);
1138 conn.cb_xprt = c->cn_xprt;
1139 ses = c->cn_session;
1140 }
1141 spin_unlock(&clp->cl_lock);
1142
1143 err = setup_callback_client(clp, &conn, ses);
1144 if (err) {
1145 nfsd4_mark_cb_down(clp, err);
1146 return;
1147 }
1148}
1149
1150static void
1151nfsd4_run_cb_work(struct work_struct *work)
1152{
1153 struct nfsd4_callback *cb =
1154 container_of(work, struct nfsd4_callback, cb_work);
1155 struct nfs4_client *clp = cb->cb_clp;
1156 struct rpc_clnt *clnt;
1157
1158 if (cb->cb_need_restart) {
1159 cb->cb_need_restart = false;
1160 } else {
1161 if (cb->cb_ops && cb->cb_ops->prepare)
1162 cb->cb_ops->prepare(cb);
1163 }
1164
1165 if (clp->cl_flags & NFSD4_CLIENT_CB_FLAG_MASK)
1166 nfsd4_process_cb_update(cb);
1167
1168 clnt = clp->cl_cb_client;
1169 if (!clnt) {
1170 /* Callback channel broken, or client killed; give up: */
1171 if (cb->cb_ops && cb->cb_ops->release)
1172 cb->cb_ops->release(cb);
1173 return;
1174 }
1175
1176 /*
1177 * Don't send probe messages for 4.1 or later.
1178 */
1179 if (!cb->cb_ops && clp->cl_minorversion) {
1180 clp->cl_cb_state = NFSD4_CB_UP;
1181 return;
1182 }
1183
1184 cb->cb_msg.rpc_cred = clp->cl_cb_cred;
1185 rpc_call_async(clnt, &cb->cb_msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN,
1186 cb->cb_ops ? &nfsd4_cb_ops : &nfsd4_cb_probe_ops, cb);
1187}
1188
1189void nfsd4_init_cb(struct nfsd4_callback *cb, struct nfs4_client *clp,
1190 const struct nfsd4_callback_ops *ops, enum nfsd4_cb_op op)
1191{
1192 cb->cb_clp = clp;
1193 cb->cb_msg.rpc_proc = &nfs4_cb_procedures[op];
1194 cb->cb_msg.rpc_argp = cb;
1195 cb->cb_msg.rpc_resp = cb;
1196 cb->cb_ops = ops;
1197 INIT_WORK(&cb->cb_work, nfsd4_run_cb_work);
1198 cb->cb_seq_status = 1;
1199 cb->cb_status = 0;
1200 cb->cb_need_restart = false;
1201}
1202
1203void nfsd4_run_cb(struct nfsd4_callback *cb)
1204{
1205 queue_work(callback_wq, &cb->cb_work);
1206}
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, bitmap, 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, &fattr->ncf_cb_change) < 0)
98 return -NFSERR_BAD_XDR;
99 if (bitmap[0] & FATTR4_WORD0_SIZE)
100 if (xdr_stream_decode_u64(xdr, &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, 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, 4 + length);
125 xdr_encode_opaque(p, &fh->fh_raw, 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, &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, 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, 4 + 4);
227 if (unlikely(p == NULL))
228 goto out_overflow;
229 op = be32_to_cpup(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, 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, 4 + 4);
291 if (unlikely(p == NULL))
292 goto out_overflow;
293 hdr->status = be32_to_cpup(p++);
294 /* Ignore the tag */
295 length = be32_to_cpup(p++);
296 p = xdr_inline_decode(xdr, 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_CB_RECALL);
322 encode_stateid4(xdr, &dp->dl_stid.sc_stateid);
323
324 p = xdr_reserve_space(xdr, 4);
325 *p++ = xdr_zero; /* truncate */
326
327 encode_nfs_fh4(xdr, &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_CB_RECALL_ANY);
345 encode_uint32(xdr, ra->ra_keep);
346 encode_bitmap4(xdr, 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_CB_GETATTR);
369 encode_nfs_fh4(xdr, fh);
370 encode_bitmap4(xdr, 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_CB_SEQUENCE);
397 encode_sessionid4(xdr, session);
398
399 p = xdr_reserve_space(xdr, 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, 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++);
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++);
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, OP_CB_SEQUENCE, &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, 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);
524 encode_cb_sequence4args(xdr, cb, &hdr);
525 encode_cb_getattr4args(xdr, &hdr, ncf);
526 encode_cb_nops(&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);
543 encode_cb_sequence4args(xdr, cb, &hdr);
544 encode_cb_recall4args(xdr, dp, &hdr);
545 encode_cb_nops(&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);
564 encode_cb_sequence4args(xdr, cb, &hdr);
565 encode_cb_recallany4args(xdr, &hdr, ra);
566 encode_cb_nops(&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);
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, OP_CB_GETATTR, &cb->cb_status);
608 if (status)
609 return status;
610 if (xdr_stream_decode_uint32_array(xdr, bitmap, 3) < 0)
611 return -NFSERR_BAD_XDR;
612 if (xdr_stream_decode_u32(xdr, &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, 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);
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, OP_CB_RECALL, &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);
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, OP_CB_RECALL_ANY, &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, 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, &ls->ls_stid.sc_file->fi_fhandle);
707
708 p = xdr_reserve_space(xdr, 2 * 8);
709 p = xdr_encode_hyper(p, 0);
710 xdr_encode_hyper(p, NFS4_MAX_UINT64);
711
712 encode_stateid4(xdr, &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);
730 encode_cb_sequence4args(xdr, cb, &hdr);
731 encode_cb_layout4args(xdr, ls, &hdr);
732 encode_cb_nops(&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);
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, OP_CB_LAYOUTRECALL, &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, 8 + 4 + so->so_owner.len);
760 p = xdr_encode_opaque_fixed(p, &so->so_client->cl_clientid, 8);
761 xdr_encode_opaque(p, so->so_owner.data, 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);
782 encode_cb_sequence4args(xdr, cb, &hdr);
783
784 p = xdr_reserve_space(xdr, 4);
785 *p = cpu_to_be32(OP_CB_NOTIFY_LOCK);
786 encode_nfs_fh4(xdr, &nbl->nbl_fh);
787 encode_stateowner(xdr, &lo->lo_owner);
788 hdr.nops++;
789
790 encode_cb_nops(&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);
802 if (unlikely(status))
803 return status;
804
805 status = decode_cb_sequence4res(xdr, cb);
806 if (unlikely(status || cb->cb_seq_status))
807 return status;
808
809 return decode_cb_op_status(xdr, OP_CB_NOTIFY_LOCK, &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, 4);
837 *p = cbo->co_nfserr;
838 switch (cbo->co_nfserr) {
839 case nfs_ok:
840 p = xdr_reserve_space(xdr, 4 + 8 + 4 + NFS4_VERIFIER_SIZE);
841 p = xdr_encode_empty_array(p);
842 p = xdr_encode_hyper(p, cbo->co_res.wr_bytes_written);
843 *p++ = cpu_to_be32(cbo->co_res.wr_stable_how);
844 p = xdr_encode_opaque_fixed(p, cbo->co_res.wr_verifier.data,
845 NFS4_VERIFIER_SIZE);
846 break;
847 default:
848 p = xdr_reserve_space(xdr, 8);
849 /* We always return success if bytes were written */
850 p = xdr_encode_hyper(p, 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, 4);
861 *p = cpu_to_be32(OP_CB_OFFLOAD);
862 encode_nfs_fh4(xdr, &cbo->co_fh);
863 encode_stateid4(xdr, &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);
882 encode_cb_sequence4args(xdr, cb, &hdr);
883 encode_cb_offload4args(xdr, cbo, &hdr);
884 encode_cb_nops(&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);
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, OP_CB_OFFLOAD, &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, 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(cb->cb_clp, cb);
986 return queue_work(callback_wq, &cb->cb_work);
987}
988
989static void nfsd41_cb_inflight_begin(struct nfs4_client *clp)
990{
991 atomic_inc(&clp->cl_cb_inflight);
992}
993
994static void nfsd41_cb_inflight_end(struct nfs4_client *clp)
995{
996
997 if (atomic_dec_and_test(&clp->cl_cb_inflight))
998 wake_up_var(&clp->cl_cb_inflight);
999}
1000
1001static void nfsd41_cb_inflight_wait_complete(struct nfs4_client *clp)
1002{
1003 wait_var_event(&clp->cl_cb_inflight,
1004 !atomic_read(&clp->cl_cb_inflight));
1005}
1006
1007static const struct cred *get_backchannel_cred(struct nfs4_client *clp, struct rpc_clnt *client, struct nfsd4_session *ses)
1008{
1009 if (clp->cl_minorversion == 0) {
1010 client->cl_principal = clp->cl_cred.cr_targ_princ ?
1011 clp->cl_cred.cr_targ_princ : "nfs";
1012
1013 return get_cred(rpc_machine_cred());
1014 } else {
1015 struct cred *kcred;
1016
1017 kcred = prepare_kernel_cred(&init_task);
1018 if (!kcred)
1019 return NULL;
1020
1021 kcred->fsuid = ses->se_cb_sec.uid;
1022 kcred->fsgid = ses->se_cb_sec.gid;
1023 return kcred;
1024 }
1025}
1026
1027static int setup_callback_client(struct nfs4_client *clp, struct nfs4_cb_conn *conn, struct nfsd4_session *ses)
1028{
1029 int maxtime = max_cb_time(clp->net);
1030 struct rpc_timeout timeparms = {
1031 .to_initval = maxtime,
1032 .to_retries = 0,
1033 .to_maxval = maxtime,
1034 };
1035 struct rpc_create_args args = {
1036 .net = clp->net,
1037 .address = (struct sockaddr *) &conn->cb_addr,
1038 .addrsize = conn->cb_addrlen,
1039 .saddress = (struct sockaddr *) &conn->cb_saddr,
1040 .timeout = &timeparms,
1041 .program = &cb_program,
1042 .version = 1,
1043 .flags = (RPC_CLNT_CREATE_NOPING | RPC_CLNT_CREATE_QUIET),
1044 .cred = current_cred(),
1045 };
1046 struct rpc_clnt *client;
1047 const struct cred *cred;
1048
1049 if (clp->cl_minorversion == 0) {
1050 if (!clp->cl_cred.cr_principal &&
1051 (clp->cl_cred.cr_flavor >= RPC_AUTH_GSS_KRB5)) {
1052 trace_nfsd_cb_setup_err(clp, -EINVAL);
1053 return -EINVAL;
1054 }
1055 args.client_name = clp->cl_cred.cr_principal;
1056 args.prognumber = conn->cb_prog;
1057 args.protocol = XPRT_TRANSPORT_TCP;
1058 args.authflavor = clp->cl_cred.cr_flavor;
1059 clp->cl_cb_ident = conn->cb_ident;
1060 } else {
1061 if (!conn->cb_xprt)
1062 return -EINVAL;
1063 clp->cl_cb_session = ses;
1064 args.bc_xprt = conn->cb_xprt;
1065 args.prognumber = clp->cl_cb_session->se_cb_prog;
1066 args.protocol = conn->cb_xprt->xpt_class->xcl_ident |
1067 XPRT_TRANSPORT_BC;
1068 args.authflavor = ses->se_cb_sec.flavor;
1069 }
1070 /* Create RPC client */
1071 client = rpc_create(&args);
1072 if (IS_ERR(client)) {
1073 trace_nfsd_cb_setup_err(clp, PTR_ERR(client));
1074 return PTR_ERR(client);
1075 }
1076 cred = get_backchannel_cred(clp, client, ses);
1077 if (!cred) {
1078 trace_nfsd_cb_setup_err(clp, -ENOMEM);
1079 rpc_shutdown_client(client);
1080 return -ENOMEM;
1081 }
1082
1083 if (clp->cl_minorversion != 0)
1084 clp->cl_cb_conn.cb_xprt = conn->cb_xprt;
1085 clp->cl_cb_client = client;
1086 clp->cl_cb_cred = cred;
1087 rcu_read_lock();
1088 trace_nfsd_cb_setup(clp, rpc_peeraddr2str(client, RPC_DISPLAY_NETID),
1089 args.authflavor);
1090 rcu_read_unlock();
1091 return 0;
1092}
1093
1094static void nfsd4_mark_cb_state(struct nfs4_client *clp, int newstate)
1095{
1096 if (clp->cl_cb_state != newstate) {
1097 clp->cl_cb_state = newstate;
1098 trace_nfsd_cb_new_state(clp);
1099 }
1100}
1101
1102static void nfsd4_mark_cb_down(struct nfs4_client *clp)
1103{
1104 if (test_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags))
1105 return;
1106 nfsd4_mark_cb_state(clp, NFSD4_CB_DOWN);
1107}
1108
1109static void nfsd4_mark_cb_fault(struct nfs4_client *clp)
1110{
1111 if (test_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags))
1112 return;
1113 nfsd4_mark_cb_state(clp, NFSD4_CB_FAULT);
1114}
1115
1116static void nfsd4_cb_probe_done(struct rpc_task *task, void *calldata)
1117{
1118 struct nfs4_client *clp = container_of(calldata, struct nfs4_client, cl_cb_null);
1119
1120 if (task->tk_status)
1121 nfsd4_mark_cb_down(clp);
1122 else
1123 nfsd4_mark_cb_state(clp, NFSD4_CB_UP);
1124}
1125
1126static void nfsd4_cb_probe_release(void *calldata)
1127{
1128 struct nfs4_client *clp = container_of(calldata, struct nfs4_client, cl_cb_null);
1129
1130 nfsd41_cb_inflight_end(clp);
1131
1132}
1133
1134static const struct rpc_call_ops nfsd4_cb_probe_ops = {
1135 /* XXX: release method to ensure we set the cb channel down if
1136 * necessary on early failure? */
1137 .rpc_call_done = nfsd4_cb_probe_done,
1138 .rpc_release = nfsd4_cb_probe_release,
1139};
1140
1141/*
1142 * Poke the callback thread to process any updates to the callback
1143 * parameters, and send a null probe.
1144 */
1145void nfsd4_probe_callback(struct nfs4_client *clp)
1146{
1147 trace_nfsd_cb_probe(clp);
1148 nfsd4_mark_cb_state(clp, NFSD4_CB_UNKNOWN);
1149 set_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags);
1150 nfsd4_run_cb(&clp->cl_cb_null);
1151}
1152
1153void nfsd4_probe_callback_sync(struct nfs4_client *clp)
1154{
1155 nfsd4_probe_callback(clp);
1156 flush_workqueue(callback_wq);
1157}
1158
1159void nfsd4_change_callback(struct nfs4_client *clp, struct nfs4_cb_conn *conn)
1160{
1161 nfsd4_mark_cb_state(clp, NFSD4_CB_UNKNOWN);
1162 spin_lock(&clp->cl_lock);
1163 memcpy(&clp->cl_cb_conn, conn, sizeof(struct nfs4_cb_conn));
1164 spin_unlock(&clp->cl_lock);
1165}
1166
1167/*
1168 * There's currently a single callback channel slot.
1169 * If the slot is available, then mark it busy. Otherwise, set the
1170 * thread for sleeping on the callback RPC wait queue.
1171 */
1172static bool nfsd41_cb_get_slot(struct nfsd4_callback *cb, struct rpc_task *task)
1173{
1174 struct nfs4_client *clp = cb->cb_clp;
1175
1176 if (!cb->cb_holds_slot &&
1177 test_and_set_bit(0, &clp->cl_cb_slot_busy) != 0) {
1178 rpc_sleep_on(&clp->cl_cb_waitq, task, NULL);
1179 /* Race breaker */
1180 if (test_and_set_bit(0, &clp->cl_cb_slot_busy) != 0) {
1181 dprintk("%s slot is busy\n", __func__);
1182 return false;
1183 }
1184 rpc_wake_up_queued_task(&clp->cl_cb_waitq, task);
1185 }
1186 cb->cb_holds_slot = true;
1187 return true;
1188}
1189
1190static void nfsd41_cb_release_slot(struct nfsd4_callback *cb)
1191{
1192 struct nfs4_client *clp = cb->cb_clp;
1193
1194 if (cb->cb_holds_slot) {
1195 cb->cb_holds_slot = false;
1196 clear_bit(0, &clp->cl_cb_slot_busy);
1197 rpc_wake_up_next(&clp->cl_cb_waitq);
1198 }
1199}
1200
1201static void nfsd41_destroy_cb(struct nfsd4_callback *cb)
1202{
1203 struct nfs4_client *clp = cb->cb_clp;
1204
1205 trace_nfsd_cb_destroy(clp, cb);
1206 nfsd41_cb_release_slot(cb);
1207 if (cb->cb_ops && cb->cb_ops->release)
1208 cb->cb_ops->release(cb);
1209 nfsd41_cb_inflight_end(clp);
1210}
1211
1212/*
1213 * TODO: cb_sequence should support referring call lists, cachethis, multiple
1214 * slots, and mark callback channel down on communication errors.
1215 */
1216static void nfsd4_cb_prepare(struct rpc_task *task, void *calldata)
1217{
1218 struct nfsd4_callback *cb = calldata;
1219 struct nfs4_client *clp = cb->cb_clp;
1220 u32 minorversion = clp->cl_minorversion;
1221
1222 /*
1223 * cb_seq_status is only set in decode_cb_sequence4res,
1224 * and so will remain 1 if an rpc level failure occurs.
1225 */
1226 cb->cb_seq_status = 1;
1227 cb->cb_status = 0;
1228 if (minorversion && !nfsd41_cb_get_slot(cb, task))
1229 return;
1230 rpc_call_start(task);
1231}
1232
1233static bool nfsd4_cb_sequence_done(struct rpc_task *task, struct nfsd4_callback *cb)
1234{
1235 struct nfs4_client *clp = cb->cb_clp;
1236 struct nfsd4_session *session = clp->cl_cb_session;
1237 bool ret = true;
1238
1239 if (!clp->cl_minorversion) {
1240 /*
1241 * If the backchannel connection was shut down while this
1242 * task was queued, we need to resubmit it after setting up
1243 * a new backchannel connection.
1244 *
1245 * Note that if we lost our callback connection permanently
1246 * the submission code will error out, so we don't need to
1247 * handle that case here.
1248 */
1249 if (RPC_SIGNALLED(task))
1250 goto need_restart;
1251
1252 return true;
1253 }
1254
1255 if (!cb->cb_holds_slot)
1256 goto need_restart;
1257
1258 /* This is the operation status code for CB_SEQUENCE */
1259 trace_nfsd_cb_seq_status(task, cb);
1260 switch (cb->cb_seq_status) {
1261 case 0:
1262 /*
1263 * No need for lock, access serialized in nfsd4_cb_prepare
1264 *
1265 * RFC5661 20.9.3
1266 * If CB_SEQUENCE returns an error, then the state of the slot
1267 * (sequence ID, cached reply) MUST NOT change.
1268 */
1269 ++session->se_cb_seq_nr;
1270 break;
1271 case -ESERVERFAULT:
1272 ++session->se_cb_seq_nr;
1273 nfsd4_mark_cb_fault(cb->cb_clp);
1274 ret = false;
1275 break;
1276 case 1:
1277 /*
1278 * cb_seq_status remains 1 if an RPC Reply was never
1279 * received. NFSD can't know if the client processed
1280 * the CB_SEQUENCE operation. Ask the client to send a
1281 * DESTROY_SESSION to recover.
1282 */
1283 fallthrough;
1284 case -NFS4ERR_BADSESSION:
1285 nfsd4_mark_cb_fault(cb->cb_clp);
1286 ret = false;
1287 goto need_restart;
1288 case -NFS4ERR_DELAY:
1289 cb->cb_seq_status = 1;
1290 if (!rpc_restart_call(task))
1291 goto out;
1292
1293 rpc_delay(task, 2 * HZ);
1294 return false;
1295 case -NFS4ERR_BADSLOT:
1296 goto retry_nowait;
1297 case -NFS4ERR_SEQ_MISORDERED:
1298 if (session->se_cb_seq_nr != 1) {
1299 session->se_cb_seq_nr = 1;
1300 goto retry_nowait;
1301 }
1302 break;
1303 default:
1304 nfsd4_mark_cb_fault(cb->cb_clp);
1305 }
1306 nfsd41_cb_release_slot(cb);
1307
1308 trace_nfsd_cb_free_slot(task, cb);
1309
1310 if (RPC_SIGNALLED(task))
1311 goto need_restart;
1312out:
1313 return ret;
1314retry_nowait:
1315 if (rpc_restart_call_prepare(task))
1316 ret = false;
1317 goto out;
1318need_restart:
1319 if (!test_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags)) {
1320 trace_nfsd_cb_restart(clp, cb);
1321 task->tk_status = 0;
1322 cb->cb_need_restart = true;
1323 }
1324 return false;
1325}
1326
1327static void nfsd4_cb_done(struct rpc_task *task, void *calldata)
1328{
1329 struct nfsd4_callback *cb = calldata;
1330 struct nfs4_client *clp = cb->cb_clp;
1331
1332 if (!nfsd4_cb_sequence_done(task, cb))
1333 return;
1334
1335 if (cb->cb_status) {
1336 WARN_ON_ONCE(task->tk_status);
1337 task->tk_status = cb->cb_status;
1338 }
1339
1340 switch (cb->cb_ops->done(cb, task)) {
1341 case 0:
1342 task->tk_status = 0;
1343 rpc_restart_call_prepare(task);
1344 return;
1345 case 1:
1346 switch (task->tk_status) {
1347 case -EIO:
1348 case -ETIMEDOUT:
1349 case -EACCES:
1350 nfsd4_mark_cb_down(clp);
1351 }
1352 break;
1353 default:
1354 BUG();
1355 }
1356}
1357
1358static void nfsd4_cb_release(void *calldata)
1359{
1360 struct nfsd4_callback *cb = calldata;
1361
1362 if (cb->cb_need_restart)
1363 nfsd4_queue_cb(cb);
1364 else
1365 nfsd41_destroy_cb(cb);
1366
1367}
1368
1369static const struct rpc_call_ops nfsd4_cb_ops = {
1370 .rpc_call_prepare = nfsd4_cb_prepare,
1371 .rpc_call_done = nfsd4_cb_done,
1372 .rpc_release = nfsd4_cb_release,
1373};
1374
1375int nfsd4_create_callback_queue(void)
1376{
1377 callback_wq = alloc_ordered_workqueue("nfsd4_callbacks", 0);
1378 if (!callback_wq)
1379 return -ENOMEM;
1380 return 0;
1381}
1382
1383void nfsd4_destroy_callback_queue(void)
1384{
1385 destroy_workqueue(callback_wq);
1386}
1387
1388/* must be called under the state lock */
1389void nfsd4_shutdown_callback(struct nfs4_client *clp)
1390{
1391 if (clp->cl_cb_state != NFSD4_CB_UNKNOWN)
1392 trace_nfsd_cb_shutdown(clp);
1393
1394 set_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags);
1395 /*
1396 * Note this won't actually result in a null callback;
1397 * instead, nfsd4_run_cb_null() will detect the killed
1398 * client, destroy the rpc client, and stop:
1399 */
1400 nfsd4_run_cb(&clp->cl_cb_null);
1401 flush_workqueue(callback_wq);
1402 nfsd41_cb_inflight_wait_complete(clp);
1403}
1404
1405static struct nfsd4_conn * __nfsd4_find_backchannel(struct nfs4_client *clp)
1406{
1407 struct nfsd4_session *s;
1408 struct nfsd4_conn *c;
1409
1410 lockdep_assert_held(&clp->cl_lock);
1411
1412 list_for_each_entry(s, &clp->cl_sessions, se_perclnt) {
1413 list_for_each_entry(c, &s->se_conns, cn_persession) {
1414 if (c->cn_flags & NFS4_CDFC4_BACK)
1415 return c;
1416 }
1417 }
1418 return NULL;
1419}
1420
1421/*
1422 * Note there isn't a lot of locking in this code; instead we depend on
1423 * the fact that it is run from the callback_wq, which won't run two
1424 * work items at once. So, for example, callback_wq handles all access
1425 * of cl_cb_client and all calls to rpc_create or rpc_shutdown_client.
1426 */
1427static void nfsd4_process_cb_update(struct nfsd4_callback *cb)
1428{
1429 struct nfs4_cb_conn conn;
1430 struct nfs4_client *clp = cb->cb_clp;
1431 struct nfsd4_session *ses = NULL;
1432 struct nfsd4_conn *c;
1433 int err;
1434
1435 trace_nfsd_cb_bc_update(clp, cb);
1436
1437 /*
1438 * This is either an update, or the client dying; in either case,
1439 * kill the old client:
1440 */
1441 if (clp->cl_cb_client) {
1442 trace_nfsd_cb_bc_shutdown(clp, cb);
1443 rpc_shutdown_client(clp->cl_cb_client);
1444 clp->cl_cb_client = NULL;
1445 put_cred(clp->cl_cb_cred);
1446 clp->cl_cb_cred = NULL;
1447 }
1448 if (clp->cl_cb_conn.cb_xprt) {
1449 svc_xprt_put(clp->cl_cb_conn.cb_xprt);
1450 clp->cl_cb_conn.cb_xprt = NULL;
1451 }
1452 if (test_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags))
1453 return;
1454
1455 spin_lock(&clp->cl_lock);
1456 /*
1457 * Only serialized callback code is allowed to clear these
1458 * flags; main nfsd code can only set them:
1459 */
1460 WARN_ON(!(clp->cl_flags & NFSD4_CLIENT_CB_FLAG_MASK));
1461 clear_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags);
1462
1463 memcpy(&conn, &cb->cb_clp->cl_cb_conn, sizeof(struct nfs4_cb_conn));
1464 c = __nfsd4_find_backchannel(clp);
1465 if (c) {
1466 svc_xprt_get(c->cn_xprt);
1467 conn.cb_xprt = c->cn_xprt;
1468 ses = c->cn_session;
1469 }
1470 spin_unlock(&clp->cl_lock);
1471
1472 err = setup_callback_client(clp, &conn, ses);
1473 if (err) {
1474 nfsd4_mark_cb_down(clp);
1475 if (c)
1476 svc_xprt_put(c->cn_xprt);
1477 return;
1478 }
1479}
1480
1481static void
1482nfsd4_run_cb_work(struct work_struct *work)
1483{
1484 struct nfsd4_callback *cb =
1485 container_of(work, struct nfsd4_callback, cb_work);
1486 struct nfs4_client *clp = cb->cb_clp;
1487 struct rpc_clnt *clnt;
1488 int flags;
1489
1490 trace_nfsd_cb_start(clp);
1491
1492 if (clp->cl_flags & NFSD4_CLIENT_CB_FLAG_MASK)
1493 nfsd4_process_cb_update(cb);
1494
1495 clnt = clp->cl_cb_client;
1496 if (!clnt) {
1497 /* Callback channel broken, or client killed; give up: */
1498 nfsd41_destroy_cb(cb);
1499 return;
1500 }
1501
1502 /*
1503 * Don't send probe messages for 4.1 or later.
1504 */
1505 if (!cb->cb_ops && clp->cl_minorversion) {
1506 nfsd4_mark_cb_state(clp, NFSD4_CB_UP);
1507 nfsd41_destroy_cb(cb);
1508 return;
1509 }
1510
1511 if (cb->cb_need_restart) {
1512 cb->cb_need_restart = false;
1513 } else {
1514 if (cb->cb_ops && cb->cb_ops->prepare)
1515 cb->cb_ops->prepare(cb);
1516 }
1517 cb->cb_msg.rpc_cred = clp->cl_cb_cred;
1518 flags = clp->cl_minorversion ? RPC_TASK_NOCONNECT : RPC_TASK_SOFTCONN;
1519 rpc_call_async(clnt, &cb->cb_msg, RPC_TASK_SOFT | flags,
1520 cb->cb_ops ? &nfsd4_cb_ops : &nfsd4_cb_probe_ops, cb);
1521}
1522
1523void nfsd4_init_cb(struct nfsd4_callback *cb, struct nfs4_client *clp,
1524 const struct nfsd4_callback_ops *ops, enum nfsd4_cb_op op)
1525{
1526 cb->cb_clp = clp;
1527 cb->cb_msg.rpc_proc = &nfs4_cb_procedures[op];
1528 cb->cb_msg.rpc_argp = cb;
1529 cb->cb_msg.rpc_resp = cb;
1530 cb->cb_ops = ops;
1531 INIT_WORK(&cb->cb_work, nfsd4_run_cb_work);
1532 cb->cb_status = 0;
1533 cb->cb_need_restart = false;
1534 cb->cb_holds_slot = false;
1535}
1536
1537/**
1538 * nfsd4_run_cb - queue up a callback job to run
1539 * @cb: callback to queue
1540 *
1541 * Kick off a callback to do its thing. Returns false if it was already
1542 * on a queue, true otherwise.
1543 */
1544bool nfsd4_run_cb(struct nfsd4_callback *cb)
1545{
1546 struct nfs4_client *clp = cb->cb_clp;
1547 bool queued;
1548
1549 nfsd41_cb_inflight_begin(clp);
1550 queued = nfsd4_queue_cb(cb);
1551 if (!queued)
1552 nfsd41_cb_inflight_end(clp);
1553 return queued;
1554}