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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_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_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_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
626/*
627 * RPC procedure tables
628 */
629#define PROC(proc, call, argtype, restype) \
630[NFSPROC4_CLNT_##proc] = { \
631 .p_proc = NFSPROC4_CB_##call, \
632 .p_encode = (kxdreproc_t)nfs4_xdr_enc_##argtype, \
633 .p_decode = (kxdrdproc_t)nfs4_xdr_dec_##restype, \
634 .p_arglen = NFS4_enc_##argtype##_sz, \
635 .p_replen = NFS4_dec_##restype##_sz, \
636 .p_statidx = NFSPROC4_CB_##call, \
637 .p_name = #proc, \
638}
639
640static struct rpc_procinfo nfs4_cb_procedures[] = {
641 PROC(CB_NULL, NULL, cb_null, cb_null),
642 PROC(CB_RECALL, COMPOUND, cb_recall, cb_recall),
643#ifdef CONFIG_NFSD_PNFS
644 PROC(CB_LAYOUT, COMPOUND, cb_layout, cb_layout),
645#endif
646};
647
648static struct rpc_version nfs_cb_version4 = {
649/*
650 * Note on the callback rpc program version number: despite language in rfc
651 * 5661 section 18.36.3 requiring servers to use 4 in this field, the
652 * official xdr descriptions for both 4.0 and 4.1 specify version 1, and
653 * in practice that appears to be what implementations use. The section
654 * 18.36.3 language is expected to be fixed in an erratum.
655 */
656 .number = 1,
657 .nrprocs = ARRAY_SIZE(nfs4_cb_procedures),
658 .procs = nfs4_cb_procedures
659};
660
661static const struct rpc_version *nfs_cb_version[] = {
662 &nfs_cb_version4,
663};
664
665static const struct rpc_program cb_program;
666
667static struct rpc_stat cb_stats = {
668 .program = &cb_program
669};
670
671#define NFS4_CALLBACK 0x40000000
672static const struct rpc_program cb_program = {
673 .name = "nfs4_cb",
674 .number = NFS4_CALLBACK,
675 .nrvers = ARRAY_SIZE(nfs_cb_version),
676 .version = nfs_cb_version,
677 .stats = &cb_stats,
678 .pipe_dir_name = "nfsd4_cb",
679};
680
681static int max_cb_time(struct net *net)
682{
683 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
684 return max(nn->nfsd4_lease/10, (time_t)1) * HZ;
685}
686
687static struct rpc_cred *callback_cred;
688
689int set_callback_cred(void)
690{
691 if (callback_cred)
692 return 0;
693 callback_cred = rpc_lookup_machine_cred("nfs");
694 if (!callback_cred)
695 return -ENOMEM;
696 return 0;
697}
698
699static struct rpc_cred *get_backchannel_cred(struct nfs4_client *clp, struct rpc_clnt *client, struct nfsd4_session *ses)
700{
701 if (clp->cl_minorversion == 0) {
702 return get_rpccred(callback_cred);
703 } else {
704 struct rpc_auth *auth = client->cl_auth;
705 struct auth_cred acred = {};
706
707 acred.uid = ses->se_cb_sec.uid;
708 acred.gid = ses->se_cb_sec.gid;
709 return auth->au_ops->lookup_cred(client->cl_auth, &acred, 0);
710 }
711}
712
713static struct rpc_clnt *create_backchannel_client(struct rpc_create_args *args)
714{
715 struct rpc_xprt *xprt;
716
717 if (args->protocol != XPRT_TRANSPORT_BC_TCP)
718 return rpc_create(args);
719
720 xprt = args->bc_xprt->xpt_bc_xprt;
721 if (xprt) {
722 xprt_get(xprt);
723 return rpc_create_xprt(args, xprt);
724 }
725
726 return rpc_create(args);
727}
728
729static int setup_callback_client(struct nfs4_client *clp, struct nfs4_cb_conn *conn, struct nfsd4_session *ses)
730{
731 int maxtime = max_cb_time(clp->net);
732 struct rpc_timeout timeparms = {
733 .to_initval = maxtime,
734 .to_retries = 0,
735 .to_maxval = maxtime,
736 };
737 struct rpc_create_args args = {
738 .net = clp->net,
739 .address = (struct sockaddr *) &conn->cb_addr,
740 .addrsize = conn->cb_addrlen,
741 .saddress = (struct sockaddr *) &conn->cb_saddr,
742 .timeout = &timeparms,
743 .program = &cb_program,
744 .version = 0,
745 .flags = (RPC_CLNT_CREATE_NOPING | RPC_CLNT_CREATE_QUIET),
746 };
747 struct rpc_clnt *client;
748 struct rpc_cred *cred;
749
750 if (clp->cl_minorversion == 0) {
751 if (!clp->cl_cred.cr_principal &&
752 (clp->cl_cred.cr_flavor >= RPC_AUTH_GSS_KRB5))
753 return -EINVAL;
754 args.client_name = clp->cl_cred.cr_principal;
755 args.prognumber = conn->cb_prog;
756 args.protocol = XPRT_TRANSPORT_TCP;
757 args.authflavor = clp->cl_cred.cr_flavor;
758 clp->cl_cb_ident = conn->cb_ident;
759 } else {
760 if (!conn->cb_xprt)
761 return -EINVAL;
762 clp->cl_cb_conn.cb_xprt = conn->cb_xprt;
763 clp->cl_cb_session = ses;
764 args.bc_xprt = conn->cb_xprt;
765 args.prognumber = clp->cl_cb_session->se_cb_prog;
766 args.protocol = conn->cb_xprt->xpt_class->xcl_ident |
767 XPRT_TRANSPORT_BC;
768 args.authflavor = ses->se_cb_sec.flavor;
769 }
770 /* Create RPC client */
771 client = create_backchannel_client(&args);
772 if (IS_ERR(client)) {
773 dprintk("NFSD: couldn't create callback client: %ld\n",
774 PTR_ERR(client));
775 return PTR_ERR(client);
776 }
777 cred = get_backchannel_cred(clp, client, ses);
778 if (IS_ERR(cred)) {
779 rpc_shutdown_client(client);
780 return PTR_ERR(cred);
781 }
782 clp->cl_cb_client = client;
783 clp->cl_cb_cred = cred;
784 return 0;
785}
786
787static void warn_no_callback_path(struct nfs4_client *clp, int reason)
788{
789 dprintk("NFSD: warning: no callback path to client %.*s: error %d\n",
790 (int)clp->cl_name.len, clp->cl_name.data, reason);
791}
792
793static void nfsd4_mark_cb_down(struct nfs4_client *clp, int reason)
794{
795 if (test_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags))
796 return;
797 clp->cl_cb_state = NFSD4_CB_DOWN;
798 warn_no_callback_path(clp, reason);
799}
800
801static void nfsd4_mark_cb_fault(struct nfs4_client *clp, int reason)
802{
803 if (test_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags))
804 return;
805 clp->cl_cb_state = NFSD4_CB_FAULT;
806 warn_no_callback_path(clp, reason);
807}
808
809static void nfsd4_cb_probe_done(struct rpc_task *task, void *calldata)
810{
811 struct nfs4_client *clp = container_of(calldata, struct nfs4_client, cl_cb_null);
812
813 if (task->tk_status)
814 nfsd4_mark_cb_down(clp, task->tk_status);
815 else
816 clp->cl_cb_state = NFSD4_CB_UP;
817}
818
819static const struct rpc_call_ops nfsd4_cb_probe_ops = {
820 /* XXX: release method to ensure we set the cb channel down if
821 * necessary on early failure? */
822 .rpc_call_done = nfsd4_cb_probe_done,
823};
824
825static struct workqueue_struct *callback_wq;
826
827/*
828 * Poke the callback thread to process any updates to the callback
829 * parameters, and send a null probe.
830 */
831void nfsd4_probe_callback(struct nfs4_client *clp)
832{
833 clp->cl_cb_state = NFSD4_CB_UNKNOWN;
834 set_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags);
835 nfsd4_run_cb(&clp->cl_cb_null);
836}
837
838void nfsd4_probe_callback_sync(struct nfs4_client *clp)
839{
840 nfsd4_probe_callback(clp);
841 flush_workqueue(callback_wq);
842}
843
844void nfsd4_change_callback(struct nfs4_client *clp, struct nfs4_cb_conn *conn)
845{
846 clp->cl_cb_state = NFSD4_CB_UNKNOWN;
847 spin_lock(&clp->cl_lock);
848 memcpy(&clp->cl_cb_conn, conn, sizeof(struct nfs4_cb_conn));
849 spin_unlock(&clp->cl_lock);
850}
851
852/*
853 * There's currently a single callback channel slot.
854 * If the slot is available, then mark it busy. Otherwise, set the
855 * thread for sleeping on the callback RPC wait queue.
856 */
857static bool nfsd41_cb_get_slot(struct nfs4_client *clp, struct rpc_task *task)
858{
859 if (test_and_set_bit(0, &clp->cl_cb_slot_busy) != 0) {
860 rpc_sleep_on(&clp->cl_cb_waitq, task, NULL);
861 /* Race breaker */
862 if (test_and_set_bit(0, &clp->cl_cb_slot_busy) != 0) {
863 dprintk("%s slot is busy\n", __func__);
864 return false;
865 }
866 rpc_wake_up_queued_task(&clp->cl_cb_waitq, task);
867 }
868 return true;
869}
870
871/*
872 * TODO: cb_sequence should support referring call lists, cachethis, multiple
873 * slots, and mark callback channel down on communication errors.
874 */
875static void nfsd4_cb_prepare(struct rpc_task *task, void *calldata)
876{
877 struct nfsd4_callback *cb = calldata;
878 struct nfs4_client *clp = cb->cb_clp;
879 u32 minorversion = clp->cl_minorversion;
880
881 cb->cb_minorversion = minorversion;
882 /*
883 * cb_seq_status is only set in decode_cb_sequence4res,
884 * and so will remain 1 if an rpc level failure occurs.
885 */
886 cb->cb_seq_status = 1;
887 cb->cb_status = 0;
888 if (minorversion) {
889 if (!nfsd41_cb_get_slot(clp, task))
890 return;
891 }
892 rpc_call_start(task);
893}
894
895static bool nfsd4_cb_sequence_done(struct rpc_task *task, struct nfsd4_callback *cb)
896{
897 struct nfs4_client *clp = cb->cb_clp;
898 struct nfsd4_session *session = clp->cl_cb_session;
899 bool ret = true;
900
901 if (!clp->cl_minorversion) {
902 /*
903 * If the backchannel connection was shut down while this
904 * task was queued, we need to resubmit it after setting up
905 * a new backchannel connection.
906 *
907 * Note that if we lost our callback connection permanently
908 * the submission code will error out, so we don't need to
909 * handle that case here.
910 */
911 if (task->tk_flags & RPC_TASK_KILLED)
912 goto need_restart;
913
914 return true;
915 }
916
917 switch (cb->cb_seq_status) {
918 case 0:
919 /*
920 * No need for lock, access serialized in nfsd4_cb_prepare
921 *
922 * RFC5661 20.9.3
923 * If CB_SEQUENCE returns an error, then the state of the slot
924 * (sequence ID, cached reply) MUST NOT change.
925 */
926 ++session->se_cb_seq_nr;
927 break;
928 case -ESERVERFAULT:
929 ++session->se_cb_seq_nr;
930 case 1:
931 case -NFS4ERR_BADSESSION:
932 nfsd4_mark_cb_fault(cb->cb_clp, cb->cb_seq_status);
933 ret = false;
934 break;
935 case -NFS4ERR_DELAY:
936 if (!rpc_restart_call(task))
937 goto out;
938
939 rpc_delay(task, 2 * HZ);
940 return false;
941 case -NFS4ERR_BADSLOT:
942 goto retry_nowait;
943 case -NFS4ERR_SEQ_MISORDERED:
944 if (session->se_cb_seq_nr != 1) {
945 session->se_cb_seq_nr = 1;
946 goto retry_nowait;
947 }
948 break;
949 default:
950 dprintk("%s: unprocessed error %d\n", __func__,
951 cb->cb_seq_status);
952 }
953
954 clear_bit(0, &clp->cl_cb_slot_busy);
955 rpc_wake_up_next(&clp->cl_cb_waitq);
956 dprintk("%s: freed slot, new seqid=%d\n", __func__,
957 clp->cl_cb_session->se_cb_seq_nr);
958
959 if (task->tk_flags & RPC_TASK_KILLED)
960 goto need_restart;
961out:
962 return ret;
963retry_nowait:
964 if (rpc_restart_call_prepare(task))
965 ret = false;
966 goto out;
967need_restart:
968 task->tk_status = 0;
969 cb->cb_need_restart = true;
970 return false;
971}
972
973static void nfsd4_cb_done(struct rpc_task *task, void *calldata)
974{
975 struct nfsd4_callback *cb = calldata;
976 struct nfs4_client *clp = cb->cb_clp;
977
978 dprintk("%s: minorversion=%d\n", __func__,
979 clp->cl_minorversion);
980
981 if (!nfsd4_cb_sequence_done(task, cb))
982 return;
983
984 if (cb->cb_status) {
985 WARN_ON_ONCE(task->tk_status);
986 task->tk_status = cb->cb_status;
987 }
988
989 switch (cb->cb_ops->done(cb, task)) {
990 case 0:
991 task->tk_status = 0;
992 rpc_restart_call_prepare(task);
993 return;
994 case 1:
995 break;
996 case -1:
997 /* Network partition? */
998 nfsd4_mark_cb_down(clp, task->tk_status);
999 break;
1000 default:
1001 BUG();
1002 }
1003}
1004
1005static void nfsd4_cb_release(void *calldata)
1006{
1007 struct nfsd4_callback *cb = calldata;
1008
1009 if (cb->cb_need_restart)
1010 nfsd4_run_cb(cb);
1011 else
1012 cb->cb_ops->release(cb);
1013
1014}
1015
1016static const struct rpc_call_ops nfsd4_cb_ops = {
1017 .rpc_call_prepare = nfsd4_cb_prepare,
1018 .rpc_call_done = nfsd4_cb_done,
1019 .rpc_release = nfsd4_cb_release,
1020};
1021
1022int nfsd4_create_callback_queue(void)
1023{
1024 callback_wq = create_singlethread_workqueue("nfsd4_callbacks");
1025 if (!callback_wq)
1026 return -ENOMEM;
1027 return 0;
1028}
1029
1030void nfsd4_destroy_callback_queue(void)
1031{
1032 destroy_workqueue(callback_wq);
1033}
1034
1035/* must be called under the state lock */
1036void nfsd4_shutdown_callback(struct nfs4_client *clp)
1037{
1038 set_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags);
1039 /*
1040 * Note this won't actually result in a null callback;
1041 * instead, nfsd4_run_cb_null() will detect the killed
1042 * client, destroy the rpc client, and stop:
1043 */
1044 nfsd4_run_cb(&clp->cl_cb_null);
1045 flush_workqueue(callback_wq);
1046}
1047
1048/* requires cl_lock: */
1049static struct nfsd4_conn * __nfsd4_find_backchannel(struct nfs4_client *clp)
1050{
1051 struct nfsd4_session *s;
1052 struct nfsd4_conn *c;
1053
1054 list_for_each_entry(s, &clp->cl_sessions, se_perclnt) {
1055 list_for_each_entry(c, &s->se_conns, cn_persession) {
1056 if (c->cn_flags & NFS4_CDFC4_BACK)
1057 return c;
1058 }
1059 }
1060 return NULL;
1061}
1062
1063static void nfsd4_process_cb_update(struct nfsd4_callback *cb)
1064{
1065 struct nfs4_cb_conn conn;
1066 struct nfs4_client *clp = cb->cb_clp;
1067 struct nfsd4_session *ses = NULL;
1068 struct nfsd4_conn *c;
1069 int err;
1070
1071 /*
1072 * This is either an update, or the client dying; in either case,
1073 * kill the old client:
1074 */
1075 if (clp->cl_cb_client) {
1076 rpc_shutdown_client(clp->cl_cb_client);
1077 clp->cl_cb_client = NULL;
1078 put_rpccred(clp->cl_cb_cred);
1079 clp->cl_cb_cred = NULL;
1080 }
1081 if (clp->cl_cb_conn.cb_xprt) {
1082 svc_xprt_put(clp->cl_cb_conn.cb_xprt);
1083 clp->cl_cb_conn.cb_xprt = NULL;
1084 }
1085 if (test_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags))
1086 return;
1087 spin_lock(&clp->cl_lock);
1088 /*
1089 * Only serialized callback code is allowed to clear these
1090 * flags; main nfsd code can only set them:
1091 */
1092 BUG_ON(!(clp->cl_flags & NFSD4_CLIENT_CB_FLAG_MASK));
1093 clear_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags);
1094 memcpy(&conn, &cb->cb_clp->cl_cb_conn, sizeof(struct nfs4_cb_conn));
1095 c = __nfsd4_find_backchannel(clp);
1096 if (c) {
1097 svc_xprt_get(c->cn_xprt);
1098 conn.cb_xprt = c->cn_xprt;
1099 ses = c->cn_session;
1100 }
1101 spin_unlock(&clp->cl_lock);
1102
1103 err = setup_callback_client(clp, &conn, ses);
1104 if (err) {
1105 nfsd4_mark_cb_down(clp, err);
1106 return;
1107 }
1108}
1109
1110static void
1111nfsd4_run_cb_work(struct work_struct *work)
1112{
1113 struct nfsd4_callback *cb =
1114 container_of(work, struct nfsd4_callback, cb_work);
1115 struct nfs4_client *clp = cb->cb_clp;
1116 struct rpc_clnt *clnt;
1117
1118 if (cb->cb_need_restart) {
1119 cb->cb_need_restart = false;
1120 } else {
1121 if (cb->cb_ops && cb->cb_ops->prepare)
1122 cb->cb_ops->prepare(cb);
1123 }
1124
1125 if (clp->cl_flags & NFSD4_CLIENT_CB_FLAG_MASK)
1126 nfsd4_process_cb_update(cb);
1127
1128 clnt = clp->cl_cb_client;
1129 if (!clnt) {
1130 /* Callback channel broken, or client killed; give up: */
1131 if (cb->cb_ops && cb->cb_ops->release)
1132 cb->cb_ops->release(cb);
1133 return;
1134 }
1135
1136 /*
1137 * Don't send probe messages for 4.1 or later.
1138 */
1139 if (!cb->cb_ops && clp->cl_minorversion) {
1140 clp->cl_cb_state = NFSD4_CB_UP;
1141 return;
1142 }
1143
1144 cb->cb_msg.rpc_cred = clp->cl_cb_cred;
1145 rpc_call_async(clnt, &cb->cb_msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN,
1146 cb->cb_ops ? &nfsd4_cb_ops : &nfsd4_cb_probe_ops, cb);
1147}
1148
1149void nfsd4_init_cb(struct nfsd4_callback *cb, struct nfs4_client *clp,
1150 const struct nfsd4_callback_ops *ops, enum nfsd4_cb_op op)
1151{
1152 cb->cb_clp = clp;
1153 cb->cb_msg.rpc_proc = &nfs4_cb_procedures[op];
1154 cb->cb_msg.rpc_argp = cb;
1155 cb->cb_msg.rpc_resp = cb;
1156 cb->cb_ops = ops;
1157 INIT_WORK(&cb->cb_work, nfsd4_run_cb_work);
1158 cb->cb_seq_status = 1;
1159 cb->cb_status = 0;
1160 cb->cb_need_restart = false;
1161}
1162
1163void nfsd4_run_cb(struct nfsd4_callback *cb)
1164{
1165 queue_work(callback_wq, &cb->cb_work);
1166}
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, XDR_UNIT);
291 if (unlikely(p == NULL))
292 goto out_overflow;
293 hdr->status = be32_to_cpup(p);
294 /* Ignore the tag */
295 if (xdr_stream_decode_u32(xdr, &length) < 0)
296 goto out_overflow;
297 if (xdr_inline_decode(xdr, length) == NULL)
298 goto out_overflow;
299 if (xdr_stream_decode_u32(xdr, &hdr->nops) < 0)
300 goto out_overflow;
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 u32 bmap[1];
368
369 bmap[0] = FATTR4_WORD0_CHANGE | FATTR4_WORD0_SIZE;
370
371 encode_nfs_cb_opnum4(xdr, OP_CB_GETATTR);
372 encode_nfs_fh4(xdr, fh);
373 encode_bitmap4(xdr, bmap, ARRAY_SIZE(bmap));
374 hdr->nops++;
375}
376
377static u32 highest_slotid(struct nfsd4_session *ses)
378{
379 u32 idx;
380
381 spin_lock(&ses->se_lock);
382 idx = fls(~ses->se_cb_slot_avail);
383 if (idx > 0)
384 --idx;
385 idx = max(idx, ses->se_cb_highest_slot);
386 spin_unlock(&ses->se_lock);
387 return idx;
388}
389
390/*
391 * CB_SEQUENCE4args
392 *
393 * struct CB_SEQUENCE4args {
394 * sessionid4 csa_sessionid;
395 * sequenceid4 csa_sequenceid;
396 * slotid4 csa_slotid;
397 * slotid4 csa_highest_slotid;
398 * bool csa_cachethis;
399 * referring_call_list4 csa_referring_call_lists<>;
400 * };
401 */
402static void encode_cb_sequence4args(struct xdr_stream *xdr,
403 const struct nfsd4_callback *cb,
404 struct nfs4_cb_compound_hdr *hdr)
405{
406 struct nfsd4_session *session = cb->cb_clp->cl_cb_session;
407 __be32 *p;
408
409 if (hdr->minorversion == 0)
410 return;
411
412 encode_nfs_cb_opnum4(xdr, OP_CB_SEQUENCE);
413 encode_sessionid4(xdr, session);
414
415 p = xdr_reserve_space(xdr, 4 + 4 + 4 + 4 + 4);
416 *p++ = cpu_to_be32(session->se_cb_seq_nr[cb->cb_held_slot]); /* csa_sequenceid */
417 *p++ = cpu_to_be32(cb->cb_held_slot); /* csa_slotid */
418 *p++ = cpu_to_be32(highest_slotid(session)); /* csa_highest_slotid */
419 *p++ = xdr_zero; /* csa_cachethis */
420 xdr_encode_empty_array(p); /* csa_referring_call_lists */
421
422 hdr->nops++;
423}
424
425static void update_cb_slot_table(struct nfsd4_session *ses, u32 target)
426{
427 /* No need to do anything if nothing changed */
428 if (likely(target == READ_ONCE(ses->se_cb_highest_slot)))
429 return;
430
431 spin_lock(&ses->se_lock);
432 if (target > ses->se_cb_highest_slot) {
433 int i;
434
435 target = min(target, NFSD_BC_SLOT_TABLE_SIZE - 1);
436
437 /*
438 * Growing the slot table. Reset any new sequences to 1.
439 *
440 * NB: There is some debate about whether the RFC requires this,
441 * but the Linux client expects it.
442 */
443 for (i = ses->se_cb_highest_slot + 1; i <= target; ++i)
444 ses->se_cb_seq_nr[i] = 1;
445 }
446 ses->se_cb_highest_slot = target;
447 spin_unlock(&ses->se_lock);
448}
449
450/*
451 * CB_SEQUENCE4resok
452 *
453 * struct CB_SEQUENCE4resok {
454 * sessionid4 csr_sessionid;
455 * sequenceid4 csr_sequenceid;
456 * slotid4 csr_slotid;
457 * slotid4 csr_highest_slotid;
458 * slotid4 csr_target_highest_slotid;
459 * };
460 *
461 * union CB_SEQUENCE4res switch (nfsstat4 csr_status) {
462 * case NFS4_OK:
463 * CB_SEQUENCE4resok csr_resok4;
464 * default:
465 * void;
466 * };
467 *
468 * Our current back channel implmentation supports a single backchannel
469 * with a single slot.
470 */
471static int decode_cb_sequence4resok(struct xdr_stream *xdr,
472 struct nfsd4_callback *cb)
473{
474 struct nfsd4_session *session = cb->cb_clp->cl_cb_session;
475 int status = -ESERVERFAULT;
476 __be32 *p;
477 u32 seqid, slotid, target;
478
479 /*
480 * If the server returns different values for sessionID, slotID or
481 * sequence number, the server is looney tunes.
482 */
483 p = xdr_inline_decode(xdr, NFS4_MAX_SESSIONID_LEN + 4 + 4 + 4 + 4);
484 if (unlikely(p == NULL))
485 goto out_overflow;
486
487 if (memcmp(p, session->se_sessionid.data, NFS4_MAX_SESSIONID_LEN)) {
488 dprintk("NFS: %s Invalid session id\n", __func__);
489 goto out;
490 }
491 p += XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN);
492
493 seqid = be32_to_cpup(p++);
494 if (seqid != session->se_cb_seq_nr[cb->cb_held_slot]) {
495 dprintk("NFS: %s Invalid sequence number\n", __func__);
496 goto out;
497 }
498
499 slotid = be32_to_cpup(p++);
500 if (slotid != cb->cb_held_slot) {
501 dprintk("NFS: %s Invalid slotid\n", __func__);
502 goto out;
503 }
504
505 p++; // ignore current highest slot value
506
507 target = be32_to_cpup(p++);
508 update_cb_slot_table(session, target);
509 status = 0;
510out:
511 cb->cb_seq_status = status;
512 return status;
513out_overflow:
514 status = -EIO;
515 goto out;
516}
517
518static int decode_cb_sequence4res(struct xdr_stream *xdr,
519 struct nfsd4_callback *cb)
520{
521 int status;
522
523 if (cb->cb_clp->cl_minorversion == 0)
524 return 0;
525
526 status = decode_cb_op_status(xdr, OP_CB_SEQUENCE, &cb->cb_seq_status);
527 if (unlikely(status || cb->cb_seq_status))
528 return status;
529
530 return decode_cb_sequence4resok(xdr, cb);
531}
532
533/*
534 * NFSv4.0 and NFSv4.1 XDR encode functions
535 *
536 * NFSv4.0 callback argument types are defined in section 15 of RFC
537 * 3530: "Network File System (NFS) version 4 Protocol" and section 20
538 * of RFC 5661: "Network File System (NFS) Version 4 Minor Version 1
539 * Protocol".
540 */
541
542/*
543 * NB: Without this zero space reservation, callbacks over krb5p fail
544 */
545static void nfs4_xdr_enc_cb_null(struct rpc_rqst *req, struct xdr_stream *xdr,
546 const void *__unused)
547{
548 xdr_reserve_space(xdr, 0);
549}
550
551/*
552 * 20.1. Operation 3: CB_GETATTR - Get Attributes
553 */
554static void nfs4_xdr_enc_cb_getattr(struct rpc_rqst *req,
555 struct xdr_stream *xdr, const void *data)
556{
557 const struct nfsd4_callback *cb = data;
558 struct nfs4_cb_fattr *ncf =
559 container_of(cb, struct nfs4_cb_fattr, ncf_getattr);
560 struct nfs4_cb_compound_hdr hdr = {
561 .ident = cb->cb_clp->cl_cb_ident,
562 .minorversion = cb->cb_clp->cl_minorversion,
563 };
564
565 encode_cb_compound4args(xdr, &hdr);
566 encode_cb_sequence4args(xdr, cb, &hdr);
567 encode_cb_getattr4args(xdr, &hdr, ncf);
568 encode_cb_nops(&hdr);
569}
570
571/*
572 * 20.2. Operation 4: CB_RECALL - Recall a Delegation
573 */
574static void nfs4_xdr_enc_cb_recall(struct rpc_rqst *req, struct xdr_stream *xdr,
575 const void *data)
576{
577 const struct nfsd4_callback *cb = data;
578 const struct nfs4_delegation *dp = cb_to_delegation(cb);
579 struct nfs4_cb_compound_hdr hdr = {
580 .ident = cb->cb_clp->cl_cb_ident,
581 .minorversion = cb->cb_clp->cl_minorversion,
582 };
583
584 encode_cb_compound4args(xdr, &hdr);
585 encode_cb_sequence4args(xdr, cb, &hdr);
586 encode_cb_recall4args(xdr, dp, &hdr);
587 encode_cb_nops(&hdr);
588}
589
590/*
591 * 20.6. Operation 8: CB_RECALL_ANY - Keep Any N Recallable Objects
592 */
593static void
594nfs4_xdr_enc_cb_recall_any(struct rpc_rqst *req,
595 struct xdr_stream *xdr, const void *data)
596{
597 const struct nfsd4_callback *cb = data;
598 struct nfsd4_cb_recall_any *ra;
599 struct nfs4_cb_compound_hdr hdr = {
600 .ident = cb->cb_clp->cl_cb_ident,
601 .minorversion = cb->cb_clp->cl_minorversion,
602 };
603
604 ra = container_of(cb, struct nfsd4_cb_recall_any, ra_cb);
605 encode_cb_compound4args(xdr, &hdr);
606 encode_cb_sequence4args(xdr, cb, &hdr);
607 encode_cb_recallany4args(xdr, &hdr, ra);
608 encode_cb_nops(&hdr);
609}
610
611/*
612 * NFSv4.0 and NFSv4.1 XDR decode functions
613 *
614 * NFSv4.0 callback result types are defined in section 15 of RFC
615 * 3530: "Network File System (NFS) version 4 Protocol" and section 20
616 * of RFC 5661: "Network File System (NFS) Version 4 Minor Version 1
617 * Protocol".
618 */
619
620static int nfs4_xdr_dec_cb_null(struct rpc_rqst *req, struct xdr_stream *xdr,
621 void *__unused)
622{
623 return 0;
624}
625
626/*
627 * 20.1. Operation 3: CB_GETATTR - Get Attributes
628 */
629static int nfs4_xdr_dec_cb_getattr(struct rpc_rqst *rqstp,
630 struct xdr_stream *xdr,
631 void *data)
632{
633 struct nfsd4_callback *cb = data;
634 struct nfs4_cb_compound_hdr hdr;
635 int status;
636 u32 bitmap[3] = {0};
637 u32 attrlen;
638 struct nfs4_cb_fattr *ncf =
639 container_of(cb, struct nfs4_cb_fattr, ncf_getattr);
640
641 status = decode_cb_compound4res(xdr, &hdr);
642 if (unlikely(status))
643 return status;
644
645 status = decode_cb_sequence4res(xdr, cb);
646 if (unlikely(status || cb->cb_seq_status))
647 return status;
648
649 status = decode_cb_op_status(xdr, OP_CB_GETATTR, &cb->cb_status);
650 if (status)
651 return status;
652 if (xdr_stream_decode_uint32_array(xdr, bitmap, 3) < 0)
653 return -NFSERR_BAD_XDR;
654 if (xdr_stream_decode_u32(xdr, &attrlen) < 0)
655 return -NFSERR_BAD_XDR;
656 if (attrlen > (sizeof(ncf->ncf_cb_change) + sizeof(ncf->ncf_cb_fsize)))
657 return -NFSERR_BAD_XDR;
658 status = decode_cb_fattr4(xdr, bitmap, ncf);
659 return status;
660}
661
662/*
663 * 20.2. Operation 4: CB_RECALL - Recall a Delegation
664 */
665static int nfs4_xdr_dec_cb_recall(struct rpc_rqst *rqstp,
666 struct xdr_stream *xdr,
667 void *data)
668{
669 struct nfsd4_callback *cb = data;
670 struct nfs4_cb_compound_hdr hdr;
671 int status;
672
673 status = decode_cb_compound4res(xdr, &hdr);
674 if (unlikely(status))
675 return status;
676
677 status = decode_cb_sequence4res(xdr, cb);
678 if (unlikely(status || cb->cb_seq_status))
679 return status;
680
681 return decode_cb_op_status(xdr, OP_CB_RECALL, &cb->cb_status);
682}
683
684/*
685 * 20.6. Operation 8: CB_RECALL_ANY - Keep Any N Recallable Objects
686 */
687static int
688nfs4_xdr_dec_cb_recall_any(struct rpc_rqst *rqstp,
689 struct xdr_stream *xdr,
690 void *data)
691{
692 struct nfsd4_callback *cb = data;
693 struct nfs4_cb_compound_hdr hdr;
694 int status;
695
696 status = decode_cb_compound4res(xdr, &hdr);
697 if (unlikely(status))
698 return status;
699 status = decode_cb_sequence4res(xdr, cb);
700 if (unlikely(status || cb->cb_seq_status))
701 return status;
702 status = decode_cb_op_status(xdr, OP_CB_RECALL_ANY, &cb->cb_status);
703 return status;
704}
705
706#ifdef CONFIG_NFSD_PNFS
707/*
708 * CB_LAYOUTRECALL4args
709 *
710 * struct layoutrecall_file4 {
711 * nfs_fh4 lor_fh;
712 * offset4 lor_offset;
713 * length4 lor_length;
714 * stateid4 lor_stateid;
715 * };
716 *
717 * union layoutrecall4 switch(layoutrecall_type4 lor_recalltype) {
718 * case LAYOUTRECALL4_FILE:
719 * layoutrecall_file4 lor_layout;
720 * case LAYOUTRECALL4_FSID:
721 * fsid4 lor_fsid;
722 * case LAYOUTRECALL4_ALL:
723 * void;
724 * };
725 *
726 * struct CB_LAYOUTRECALL4args {
727 * layouttype4 clora_type;
728 * layoutiomode4 clora_iomode;
729 * bool clora_changed;
730 * layoutrecall4 clora_recall;
731 * };
732 */
733static void encode_cb_layout4args(struct xdr_stream *xdr,
734 const struct nfs4_layout_stateid *ls,
735 struct nfs4_cb_compound_hdr *hdr)
736{
737 __be32 *p;
738
739 BUG_ON(hdr->minorversion == 0);
740
741 p = xdr_reserve_space(xdr, 5 * 4);
742 *p++ = cpu_to_be32(OP_CB_LAYOUTRECALL);
743 *p++ = cpu_to_be32(ls->ls_layout_type);
744 *p++ = cpu_to_be32(IOMODE_ANY);
745 *p++ = cpu_to_be32(1);
746 *p = cpu_to_be32(RETURN_FILE);
747
748 encode_nfs_fh4(xdr, &ls->ls_stid.sc_file->fi_fhandle);
749
750 p = xdr_reserve_space(xdr, 2 * 8);
751 p = xdr_encode_hyper(p, 0);
752 xdr_encode_hyper(p, NFS4_MAX_UINT64);
753
754 encode_stateid4(xdr, &ls->ls_recall_sid);
755
756 hdr->nops++;
757}
758
759static void nfs4_xdr_enc_cb_layout(struct rpc_rqst *req,
760 struct xdr_stream *xdr,
761 const void *data)
762{
763 const struct nfsd4_callback *cb = data;
764 const struct nfs4_layout_stateid *ls =
765 container_of(cb, struct nfs4_layout_stateid, ls_recall);
766 struct nfs4_cb_compound_hdr hdr = {
767 .ident = 0,
768 .minorversion = cb->cb_clp->cl_minorversion,
769 };
770
771 encode_cb_compound4args(xdr, &hdr);
772 encode_cb_sequence4args(xdr, cb, &hdr);
773 encode_cb_layout4args(xdr, ls, &hdr);
774 encode_cb_nops(&hdr);
775}
776
777static int nfs4_xdr_dec_cb_layout(struct rpc_rqst *rqstp,
778 struct xdr_stream *xdr,
779 void *data)
780{
781 struct nfsd4_callback *cb = data;
782 struct nfs4_cb_compound_hdr hdr;
783 int status;
784
785 status = decode_cb_compound4res(xdr, &hdr);
786 if (unlikely(status))
787 return status;
788
789 status = decode_cb_sequence4res(xdr, cb);
790 if (unlikely(status || cb->cb_seq_status))
791 return status;
792
793 return decode_cb_op_status(xdr, OP_CB_LAYOUTRECALL, &cb->cb_status);
794}
795#endif /* CONFIG_NFSD_PNFS */
796
797static void encode_stateowner(struct xdr_stream *xdr, struct nfs4_stateowner *so)
798{
799 __be32 *p;
800
801 p = xdr_reserve_space(xdr, 8 + 4 + so->so_owner.len);
802 p = xdr_encode_opaque_fixed(p, &so->so_client->cl_clientid, 8);
803 xdr_encode_opaque(p, so->so_owner.data, so->so_owner.len);
804}
805
806static void nfs4_xdr_enc_cb_notify_lock(struct rpc_rqst *req,
807 struct xdr_stream *xdr,
808 const void *data)
809{
810 const struct nfsd4_callback *cb = data;
811 const struct nfsd4_blocked_lock *nbl =
812 container_of(cb, struct nfsd4_blocked_lock, nbl_cb);
813 struct nfs4_lockowner *lo = (struct nfs4_lockowner *)nbl->nbl_lock.c.flc_owner;
814 struct nfs4_cb_compound_hdr hdr = {
815 .ident = 0,
816 .minorversion = cb->cb_clp->cl_minorversion,
817 };
818
819 __be32 *p;
820
821 BUG_ON(hdr.minorversion == 0);
822
823 encode_cb_compound4args(xdr, &hdr);
824 encode_cb_sequence4args(xdr, cb, &hdr);
825
826 p = xdr_reserve_space(xdr, 4);
827 *p = cpu_to_be32(OP_CB_NOTIFY_LOCK);
828 encode_nfs_fh4(xdr, &nbl->nbl_fh);
829 encode_stateowner(xdr, &lo->lo_owner);
830 hdr.nops++;
831
832 encode_cb_nops(&hdr);
833}
834
835static int nfs4_xdr_dec_cb_notify_lock(struct rpc_rqst *rqstp,
836 struct xdr_stream *xdr,
837 void *data)
838{
839 struct nfsd4_callback *cb = data;
840 struct nfs4_cb_compound_hdr hdr;
841 int status;
842
843 status = decode_cb_compound4res(xdr, &hdr);
844 if (unlikely(status))
845 return status;
846
847 status = decode_cb_sequence4res(xdr, cb);
848 if (unlikely(status || cb->cb_seq_status))
849 return status;
850
851 return decode_cb_op_status(xdr, OP_CB_NOTIFY_LOCK, &cb->cb_status);
852}
853
854/*
855 * struct write_response4 {
856 * stateid4 wr_callback_id<1>;
857 * length4 wr_count;
858 * stable_how4 wr_committed;
859 * verifier4 wr_writeverf;
860 * };
861 * union offload_info4 switch (nfsstat4 coa_status) {
862 * case NFS4_OK:
863 * write_response4 coa_resok4;
864 * default:
865 * length4 coa_bytes_copied;
866 * };
867 * struct CB_OFFLOAD4args {
868 * nfs_fh4 coa_fh;
869 * stateid4 coa_stateid;
870 * offload_info4 coa_offload_info;
871 * };
872 */
873static void encode_offload_info4(struct xdr_stream *xdr,
874 const struct nfsd4_cb_offload *cbo)
875{
876 __be32 *p;
877
878 p = xdr_reserve_space(xdr, 4);
879 *p = cbo->co_nfserr;
880 switch (cbo->co_nfserr) {
881 case nfs_ok:
882 p = xdr_reserve_space(xdr, 4 + 8 + 4 + NFS4_VERIFIER_SIZE);
883 p = xdr_encode_empty_array(p);
884 p = xdr_encode_hyper(p, cbo->co_res.wr_bytes_written);
885 *p++ = cpu_to_be32(cbo->co_res.wr_stable_how);
886 p = xdr_encode_opaque_fixed(p, cbo->co_res.wr_verifier.data,
887 NFS4_VERIFIER_SIZE);
888 break;
889 default:
890 p = xdr_reserve_space(xdr, 8);
891 /* We always return success if bytes were written */
892 p = xdr_encode_hyper(p, 0);
893 }
894}
895
896static void encode_cb_offload4args(struct xdr_stream *xdr,
897 const struct nfsd4_cb_offload *cbo,
898 struct nfs4_cb_compound_hdr *hdr)
899{
900 __be32 *p;
901
902 p = xdr_reserve_space(xdr, 4);
903 *p = cpu_to_be32(OP_CB_OFFLOAD);
904 encode_nfs_fh4(xdr, &cbo->co_fh);
905 encode_stateid4(xdr, &cbo->co_res.cb_stateid);
906 encode_offload_info4(xdr, cbo);
907
908 hdr->nops++;
909}
910
911static void nfs4_xdr_enc_cb_offload(struct rpc_rqst *req,
912 struct xdr_stream *xdr,
913 const void *data)
914{
915 const struct nfsd4_callback *cb = data;
916 const struct nfsd4_cb_offload *cbo =
917 container_of(cb, struct nfsd4_cb_offload, co_cb);
918 struct nfs4_cb_compound_hdr hdr = {
919 .ident = 0,
920 .minorversion = cb->cb_clp->cl_minorversion,
921 };
922
923 encode_cb_compound4args(xdr, &hdr);
924 encode_cb_sequence4args(xdr, cb, &hdr);
925 encode_cb_offload4args(xdr, cbo, &hdr);
926 encode_cb_nops(&hdr);
927}
928
929static int nfs4_xdr_dec_cb_offload(struct rpc_rqst *rqstp,
930 struct xdr_stream *xdr,
931 void *data)
932{
933 struct nfsd4_callback *cb = data;
934 struct nfs4_cb_compound_hdr hdr;
935 int status;
936
937 status = decode_cb_compound4res(xdr, &hdr);
938 if (unlikely(status))
939 return status;
940
941 status = decode_cb_sequence4res(xdr, cb);
942 if (unlikely(status || cb->cb_seq_status))
943 return status;
944
945 return decode_cb_op_status(xdr, OP_CB_OFFLOAD, &cb->cb_status);
946}
947/*
948 * RPC procedure tables
949 */
950#define PROC(proc, call, argtype, restype) \
951[NFSPROC4_CLNT_##proc] = { \
952 .p_proc = NFSPROC4_CB_##call, \
953 .p_encode = nfs4_xdr_enc_##argtype, \
954 .p_decode = nfs4_xdr_dec_##restype, \
955 .p_arglen = NFS4_enc_##argtype##_sz, \
956 .p_replen = NFS4_dec_##restype##_sz, \
957 .p_statidx = NFSPROC4_CB_##call, \
958 .p_name = #proc, \
959}
960
961static const struct rpc_procinfo nfs4_cb_procedures[] = {
962 PROC(CB_NULL, NULL, cb_null, cb_null),
963 PROC(CB_RECALL, COMPOUND, cb_recall, cb_recall),
964#ifdef CONFIG_NFSD_PNFS
965 PROC(CB_LAYOUT, COMPOUND, cb_layout, cb_layout),
966#endif
967 PROC(CB_NOTIFY_LOCK, COMPOUND, cb_notify_lock, cb_notify_lock),
968 PROC(CB_OFFLOAD, COMPOUND, cb_offload, cb_offload),
969 PROC(CB_RECALL_ANY, COMPOUND, cb_recall_any, cb_recall_any),
970 PROC(CB_GETATTR, COMPOUND, cb_getattr, cb_getattr),
971};
972
973static unsigned int nfs4_cb_counts[ARRAY_SIZE(nfs4_cb_procedures)];
974static const struct rpc_version nfs_cb_version4 = {
975/*
976 * Note on the callback rpc program version number: despite language in rfc
977 * 5661 section 18.36.3 requiring servers to use 4 in this field, the
978 * official xdr descriptions for both 4.0 and 4.1 specify version 1, and
979 * in practice that appears to be what implementations use. The section
980 * 18.36.3 language is expected to be fixed in an erratum.
981 */
982 .number = 1,
983 .nrprocs = ARRAY_SIZE(nfs4_cb_procedures),
984 .procs = nfs4_cb_procedures,
985 .counts = nfs4_cb_counts,
986};
987
988static const struct rpc_version *nfs_cb_version[2] = {
989 [1] = &nfs_cb_version4,
990};
991
992static const struct rpc_program cb_program;
993
994static struct rpc_stat cb_stats = {
995 .program = &cb_program
996};
997
998#define NFS4_CALLBACK 0x40000000
999static const struct rpc_program cb_program = {
1000 .name = "nfs4_cb",
1001 .number = NFS4_CALLBACK,
1002 .nrvers = ARRAY_SIZE(nfs_cb_version),
1003 .version = nfs_cb_version,
1004 .stats = &cb_stats,
1005 .pipe_dir_name = "nfsd4_cb",
1006};
1007
1008static int max_cb_time(struct net *net)
1009{
1010 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1011
1012 /*
1013 * nfsd4_lease is set to at most one hour in __nfsd4_write_time,
1014 * so we can use 32-bit math on it. Warn if that assumption
1015 * ever stops being true.
1016 */
1017 if (WARN_ON_ONCE(nn->nfsd4_lease > 3600))
1018 return 360 * HZ;
1019
1020 return max(((u32)nn->nfsd4_lease)/10, 1u) * HZ;
1021}
1022
1023static bool nfsd4_queue_cb(struct nfsd4_callback *cb)
1024{
1025 struct nfs4_client *clp = cb->cb_clp;
1026
1027 trace_nfsd_cb_queue(clp, cb);
1028 return queue_work(clp->cl_callback_wq, &cb->cb_work);
1029}
1030
1031static void nfsd41_cb_inflight_begin(struct nfs4_client *clp)
1032{
1033 atomic_inc(&clp->cl_cb_inflight);
1034}
1035
1036static void nfsd41_cb_inflight_end(struct nfs4_client *clp)
1037{
1038
1039 if (atomic_dec_and_test(&clp->cl_cb_inflight))
1040 wake_up_var(&clp->cl_cb_inflight);
1041}
1042
1043static void nfsd41_cb_inflight_wait_complete(struct nfs4_client *clp)
1044{
1045 wait_var_event(&clp->cl_cb_inflight,
1046 !atomic_read(&clp->cl_cb_inflight));
1047}
1048
1049static const struct cred *get_backchannel_cred(struct nfs4_client *clp, struct rpc_clnt *client, struct nfsd4_session *ses)
1050{
1051 if (clp->cl_minorversion == 0) {
1052 client->cl_principal = clp->cl_cred.cr_targ_princ ?
1053 clp->cl_cred.cr_targ_princ : "nfs";
1054
1055 return get_cred(rpc_machine_cred());
1056 } else {
1057 struct cred *kcred;
1058
1059 kcred = prepare_kernel_cred(&init_task);
1060 if (!kcred)
1061 return NULL;
1062
1063 kcred->fsuid = ses->se_cb_sec.uid;
1064 kcred->fsgid = ses->se_cb_sec.gid;
1065 return kcred;
1066 }
1067}
1068
1069static int setup_callback_client(struct nfs4_client *clp, struct nfs4_cb_conn *conn, struct nfsd4_session *ses)
1070{
1071 int maxtime = max_cb_time(clp->net);
1072 struct rpc_timeout timeparms = {
1073 .to_initval = maxtime,
1074 .to_retries = 0,
1075 .to_maxval = maxtime,
1076 };
1077 struct rpc_create_args args = {
1078 .net = clp->net,
1079 .address = (struct sockaddr *) &conn->cb_addr,
1080 .addrsize = conn->cb_addrlen,
1081 .saddress = (struct sockaddr *) &conn->cb_saddr,
1082 .timeout = &timeparms,
1083 .program = &cb_program,
1084 .version = 1,
1085 .flags = (RPC_CLNT_CREATE_NOPING | RPC_CLNT_CREATE_QUIET),
1086 .cred = current_cred(),
1087 };
1088 struct rpc_clnt *client;
1089 const struct cred *cred;
1090
1091 if (clp->cl_minorversion == 0) {
1092 if (!clp->cl_cred.cr_principal &&
1093 (clp->cl_cred.cr_flavor >= RPC_AUTH_GSS_KRB5)) {
1094 trace_nfsd_cb_setup_err(clp, -EINVAL);
1095 return -EINVAL;
1096 }
1097 args.client_name = clp->cl_cred.cr_principal;
1098 args.prognumber = conn->cb_prog;
1099 args.protocol = XPRT_TRANSPORT_TCP;
1100 args.authflavor = clp->cl_cred.cr_flavor;
1101 clp->cl_cb_ident = conn->cb_ident;
1102 } else {
1103 if (!conn->cb_xprt || !ses)
1104 return -EINVAL;
1105 clp->cl_cb_session = ses;
1106 args.bc_xprt = conn->cb_xprt;
1107 args.prognumber = clp->cl_cb_session->se_cb_prog;
1108 args.protocol = conn->cb_xprt->xpt_class->xcl_ident |
1109 XPRT_TRANSPORT_BC;
1110 args.authflavor = ses->se_cb_sec.flavor;
1111 }
1112 /* Create RPC client */
1113 client = rpc_create(&args);
1114 if (IS_ERR(client)) {
1115 trace_nfsd_cb_setup_err(clp, PTR_ERR(client));
1116 return PTR_ERR(client);
1117 }
1118 cred = get_backchannel_cred(clp, client, ses);
1119 if (!cred) {
1120 trace_nfsd_cb_setup_err(clp, -ENOMEM);
1121 rpc_shutdown_client(client);
1122 return -ENOMEM;
1123 }
1124
1125 if (clp->cl_minorversion != 0)
1126 clp->cl_cb_conn.cb_xprt = conn->cb_xprt;
1127 clp->cl_cb_client = client;
1128 clp->cl_cb_cred = cred;
1129 rcu_read_lock();
1130 trace_nfsd_cb_setup(clp, rpc_peeraddr2str(client, RPC_DISPLAY_NETID),
1131 args.authflavor);
1132 rcu_read_unlock();
1133 return 0;
1134}
1135
1136static void nfsd4_mark_cb_state(struct nfs4_client *clp, int newstate)
1137{
1138 if (clp->cl_cb_state != newstate) {
1139 clp->cl_cb_state = newstate;
1140 trace_nfsd_cb_new_state(clp);
1141 }
1142}
1143
1144static void nfsd4_mark_cb_down(struct nfs4_client *clp)
1145{
1146 if (test_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags))
1147 return;
1148 nfsd4_mark_cb_state(clp, NFSD4_CB_DOWN);
1149}
1150
1151static void nfsd4_mark_cb_fault(struct nfs4_client *clp)
1152{
1153 if (test_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags))
1154 return;
1155 nfsd4_mark_cb_state(clp, NFSD4_CB_FAULT);
1156}
1157
1158static void nfsd4_cb_probe_done(struct rpc_task *task, void *calldata)
1159{
1160 struct nfs4_client *clp = container_of(calldata, struct nfs4_client, cl_cb_null);
1161
1162 if (task->tk_status)
1163 nfsd4_mark_cb_down(clp);
1164 else
1165 nfsd4_mark_cb_state(clp, NFSD4_CB_UP);
1166}
1167
1168static void nfsd4_cb_probe_release(void *calldata)
1169{
1170 struct nfs4_client *clp = container_of(calldata, struct nfs4_client, cl_cb_null);
1171
1172 nfsd41_cb_inflight_end(clp);
1173
1174}
1175
1176static const struct rpc_call_ops nfsd4_cb_probe_ops = {
1177 /* XXX: release method to ensure we set the cb channel down if
1178 * necessary on early failure? */
1179 .rpc_call_done = nfsd4_cb_probe_done,
1180 .rpc_release = nfsd4_cb_probe_release,
1181};
1182
1183/*
1184 * Poke the callback thread to process any updates to the callback
1185 * parameters, and send a null probe.
1186 */
1187void nfsd4_probe_callback(struct nfs4_client *clp)
1188{
1189 trace_nfsd_cb_probe(clp);
1190 nfsd4_mark_cb_state(clp, NFSD4_CB_UNKNOWN);
1191 set_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags);
1192 nfsd4_run_cb(&clp->cl_cb_null);
1193}
1194
1195void nfsd4_probe_callback_sync(struct nfs4_client *clp)
1196{
1197 nfsd4_probe_callback(clp);
1198 flush_workqueue(clp->cl_callback_wq);
1199}
1200
1201void nfsd4_change_callback(struct nfs4_client *clp, struct nfs4_cb_conn *conn)
1202{
1203 nfsd4_mark_cb_state(clp, NFSD4_CB_UNKNOWN);
1204 spin_lock(&clp->cl_lock);
1205 memcpy(&clp->cl_cb_conn, conn, sizeof(struct nfs4_cb_conn));
1206 spin_unlock(&clp->cl_lock);
1207}
1208
1209static int grab_slot(struct nfsd4_session *ses)
1210{
1211 int idx;
1212
1213 spin_lock(&ses->se_lock);
1214 idx = ffs(ses->se_cb_slot_avail) - 1;
1215 if (idx < 0 || idx > ses->se_cb_highest_slot) {
1216 spin_unlock(&ses->se_lock);
1217 return -1;
1218 }
1219 /* clear the bit for the slot */
1220 ses->se_cb_slot_avail &= ~BIT(idx);
1221 spin_unlock(&ses->se_lock);
1222 return idx;
1223}
1224
1225/*
1226 * There's currently a single callback channel slot.
1227 * If the slot is available, then mark it busy. Otherwise, set the
1228 * thread for sleeping on the callback RPC wait queue.
1229 */
1230static bool nfsd41_cb_get_slot(struct nfsd4_callback *cb, struct rpc_task *task)
1231{
1232 struct nfs4_client *clp = cb->cb_clp;
1233 struct nfsd4_session *ses = clp->cl_cb_session;
1234
1235 if (cb->cb_held_slot >= 0)
1236 return true;
1237 cb->cb_held_slot = grab_slot(ses);
1238 if (cb->cb_held_slot < 0) {
1239 rpc_sleep_on(&clp->cl_cb_waitq, task, NULL);
1240 /* Race breaker */
1241 cb->cb_held_slot = grab_slot(ses);
1242 if (cb->cb_held_slot < 0)
1243 return false;
1244 rpc_wake_up_queued_task(&clp->cl_cb_waitq, task);
1245 }
1246 return true;
1247}
1248
1249static void nfsd41_cb_release_slot(struct nfsd4_callback *cb)
1250{
1251 struct nfs4_client *clp = cb->cb_clp;
1252 struct nfsd4_session *ses = clp->cl_cb_session;
1253
1254 if (cb->cb_held_slot >= 0) {
1255 spin_lock(&ses->se_lock);
1256 ses->se_cb_slot_avail |= BIT(cb->cb_held_slot);
1257 spin_unlock(&ses->se_lock);
1258 cb->cb_held_slot = -1;
1259 rpc_wake_up_next(&clp->cl_cb_waitq);
1260 }
1261}
1262
1263static void nfsd41_destroy_cb(struct nfsd4_callback *cb)
1264{
1265 struct nfs4_client *clp = cb->cb_clp;
1266
1267 trace_nfsd_cb_destroy(clp, cb);
1268 nfsd41_cb_release_slot(cb);
1269 if (cb->cb_ops && cb->cb_ops->release)
1270 cb->cb_ops->release(cb);
1271 nfsd41_cb_inflight_end(clp);
1272}
1273
1274/*
1275 * TODO: cb_sequence should support referring call lists, cachethis,
1276 * and mark callback channel down on communication errors.
1277 */
1278static void nfsd4_cb_prepare(struct rpc_task *task, void *calldata)
1279{
1280 struct nfsd4_callback *cb = calldata;
1281 struct nfs4_client *clp = cb->cb_clp;
1282 u32 minorversion = clp->cl_minorversion;
1283
1284 /*
1285 * cb_seq_status is only set in decode_cb_sequence4res,
1286 * and so will remain 1 if an rpc level failure occurs.
1287 */
1288 trace_nfsd_cb_rpc_prepare(clp);
1289 cb->cb_seq_status = 1;
1290 cb->cb_status = 0;
1291 if (minorversion && !nfsd41_cb_get_slot(cb, task))
1292 return;
1293 rpc_call_start(task);
1294}
1295
1296static bool nfsd4_cb_sequence_done(struct rpc_task *task, struct nfsd4_callback *cb)
1297{
1298 struct nfs4_client *clp = cb->cb_clp;
1299 struct nfsd4_session *session = clp->cl_cb_session;
1300 bool ret = true;
1301
1302 if (!clp->cl_minorversion) {
1303 /*
1304 * If the backchannel connection was shut down while this
1305 * task was queued, we need to resubmit it after setting up
1306 * a new backchannel connection.
1307 *
1308 * Note that if we lost our callback connection permanently
1309 * the submission code will error out, so we don't need to
1310 * handle that case here.
1311 */
1312 if (RPC_SIGNALLED(task))
1313 goto need_restart;
1314
1315 return true;
1316 }
1317
1318 if (cb->cb_held_slot < 0)
1319 goto need_restart;
1320
1321 /* This is the operation status code for CB_SEQUENCE */
1322 trace_nfsd_cb_seq_status(task, cb);
1323 switch (cb->cb_seq_status) {
1324 case 0:
1325 /*
1326 * No need for lock, access serialized in nfsd4_cb_prepare
1327 *
1328 * RFC5661 20.9.3
1329 * If CB_SEQUENCE returns an error, then the state of the slot
1330 * (sequence ID, cached reply) MUST NOT change.
1331 */
1332 ++session->se_cb_seq_nr[cb->cb_held_slot];
1333 break;
1334 case -ESERVERFAULT:
1335 ++session->se_cb_seq_nr[cb->cb_held_slot];
1336 nfsd4_mark_cb_fault(cb->cb_clp);
1337 ret = false;
1338 break;
1339 case 1:
1340 /*
1341 * cb_seq_status remains 1 if an RPC Reply was never
1342 * received. NFSD can't know if the client processed
1343 * the CB_SEQUENCE operation. Ask the client to send a
1344 * DESTROY_SESSION to recover.
1345 */
1346 fallthrough;
1347 case -NFS4ERR_BADSESSION:
1348 nfsd4_mark_cb_fault(cb->cb_clp);
1349 ret = false;
1350 goto need_restart;
1351 case -NFS4ERR_DELAY:
1352 cb->cb_seq_status = 1;
1353 if (!rpc_restart_call(task))
1354 goto out;
1355
1356 rpc_delay(task, 2 * HZ);
1357 return false;
1358 case -NFS4ERR_BADSLOT:
1359 goto retry_nowait;
1360 case -NFS4ERR_SEQ_MISORDERED:
1361 if (session->se_cb_seq_nr[cb->cb_held_slot] != 1) {
1362 session->se_cb_seq_nr[cb->cb_held_slot] = 1;
1363 goto retry_nowait;
1364 }
1365 break;
1366 default:
1367 nfsd4_mark_cb_fault(cb->cb_clp);
1368 }
1369 trace_nfsd_cb_free_slot(task, cb);
1370 nfsd41_cb_release_slot(cb);
1371
1372 if (RPC_SIGNALLED(task))
1373 goto need_restart;
1374out:
1375 return ret;
1376retry_nowait:
1377 if (rpc_restart_call_prepare(task))
1378 ret = false;
1379 goto out;
1380need_restart:
1381 if (!test_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags)) {
1382 trace_nfsd_cb_restart(clp, cb);
1383 task->tk_status = 0;
1384 cb->cb_need_restart = true;
1385 }
1386 return false;
1387}
1388
1389static void nfsd4_cb_done(struct rpc_task *task, void *calldata)
1390{
1391 struct nfsd4_callback *cb = calldata;
1392 struct nfs4_client *clp = cb->cb_clp;
1393
1394 trace_nfsd_cb_rpc_done(clp);
1395
1396 if (!nfsd4_cb_sequence_done(task, cb))
1397 return;
1398
1399 if (cb->cb_status) {
1400 WARN_ONCE(task->tk_status, "cb_status=%d tk_status=%d",
1401 cb->cb_status, task->tk_status);
1402 task->tk_status = cb->cb_status;
1403 }
1404
1405 switch (cb->cb_ops->done(cb, task)) {
1406 case 0:
1407 task->tk_status = 0;
1408 rpc_restart_call_prepare(task);
1409 return;
1410 case 1:
1411 switch (task->tk_status) {
1412 case -EIO:
1413 case -ETIMEDOUT:
1414 case -EACCES:
1415 nfsd4_mark_cb_down(clp);
1416 }
1417 break;
1418 default:
1419 BUG();
1420 }
1421}
1422
1423static void nfsd4_cb_release(void *calldata)
1424{
1425 struct nfsd4_callback *cb = calldata;
1426
1427 trace_nfsd_cb_rpc_release(cb->cb_clp);
1428
1429 if (cb->cb_need_restart)
1430 nfsd4_queue_cb(cb);
1431 else
1432 nfsd41_destroy_cb(cb);
1433
1434}
1435
1436static const struct rpc_call_ops nfsd4_cb_ops = {
1437 .rpc_call_prepare = nfsd4_cb_prepare,
1438 .rpc_call_done = nfsd4_cb_done,
1439 .rpc_release = nfsd4_cb_release,
1440};
1441
1442/* must be called under the state lock */
1443void nfsd4_shutdown_callback(struct nfs4_client *clp)
1444{
1445 if (clp->cl_cb_state != NFSD4_CB_UNKNOWN)
1446 trace_nfsd_cb_shutdown(clp);
1447
1448 set_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags);
1449 /*
1450 * Note this won't actually result in a null callback;
1451 * instead, nfsd4_run_cb_null() will detect the killed
1452 * client, destroy the rpc client, and stop:
1453 */
1454 nfsd4_run_cb(&clp->cl_cb_null);
1455 flush_workqueue(clp->cl_callback_wq);
1456 nfsd41_cb_inflight_wait_complete(clp);
1457}
1458
1459static struct nfsd4_conn * __nfsd4_find_backchannel(struct nfs4_client *clp)
1460{
1461 struct nfsd4_session *s;
1462 struct nfsd4_conn *c;
1463
1464 lockdep_assert_held(&clp->cl_lock);
1465
1466 list_for_each_entry(s, &clp->cl_sessions, se_perclnt) {
1467 list_for_each_entry(c, &s->se_conns, cn_persession) {
1468 if (c->cn_flags & NFS4_CDFC4_BACK)
1469 return c;
1470 }
1471 }
1472 return NULL;
1473}
1474
1475/*
1476 * Note there isn't a lot of locking in this code; instead we depend on
1477 * the fact that it is run from clp->cl_callback_wq, which won't run two
1478 * work items at once. So, for example, clp->cl_callback_wq handles all
1479 * access of cl_cb_client and all calls to rpc_create or rpc_shutdown_client.
1480 */
1481static void nfsd4_process_cb_update(struct nfsd4_callback *cb)
1482{
1483 struct nfs4_cb_conn conn;
1484 struct nfs4_client *clp = cb->cb_clp;
1485 struct nfsd4_session *ses = NULL;
1486 struct nfsd4_conn *c;
1487 int err;
1488
1489 trace_nfsd_cb_bc_update(clp, cb);
1490
1491 /*
1492 * This is either an update, or the client dying; in either case,
1493 * kill the old client:
1494 */
1495 if (clp->cl_cb_client) {
1496 trace_nfsd_cb_bc_shutdown(clp, cb);
1497 rpc_shutdown_client(clp->cl_cb_client);
1498 clp->cl_cb_client = NULL;
1499 put_cred(clp->cl_cb_cred);
1500 clp->cl_cb_cred = NULL;
1501 }
1502 if (clp->cl_cb_conn.cb_xprt) {
1503 svc_xprt_put(clp->cl_cb_conn.cb_xprt);
1504 clp->cl_cb_conn.cb_xprt = NULL;
1505 }
1506 if (test_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags))
1507 return;
1508
1509 spin_lock(&clp->cl_lock);
1510 /*
1511 * Only serialized callback code is allowed to clear these
1512 * flags; main nfsd code can only set them:
1513 */
1514 WARN_ON(!(clp->cl_flags & NFSD4_CLIENT_CB_FLAG_MASK));
1515 clear_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags);
1516
1517 memcpy(&conn, &cb->cb_clp->cl_cb_conn, sizeof(struct nfs4_cb_conn));
1518 c = __nfsd4_find_backchannel(clp);
1519 if (c) {
1520 svc_xprt_get(c->cn_xprt);
1521 conn.cb_xprt = c->cn_xprt;
1522 ses = c->cn_session;
1523 }
1524 spin_unlock(&clp->cl_lock);
1525
1526 err = setup_callback_client(clp, &conn, ses);
1527 if (err) {
1528 nfsd4_mark_cb_down(clp);
1529 if (c)
1530 svc_xprt_put(c->cn_xprt);
1531 return;
1532 }
1533}
1534
1535static void
1536nfsd4_run_cb_work(struct work_struct *work)
1537{
1538 struct nfsd4_callback *cb =
1539 container_of(work, struct nfsd4_callback, cb_work);
1540 struct nfs4_client *clp = cb->cb_clp;
1541 struct rpc_clnt *clnt;
1542 int flags;
1543
1544 trace_nfsd_cb_start(clp);
1545
1546 if (clp->cl_flags & NFSD4_CLIENT_CB_FLAG_MASK)
1547 nfsd4_process_cb_update(cb);
1548
1549 clnt = clp->cl_cb_client;
1550 if (!clnt || clp->cl_state == NFSD4_COURTESY) {
1551 /*
1552 * Callback channel broken, client killed or
1553 * nfs4_client in courtesy state; give up.
1554 */
1555 nfsd41_destroy_cb(cb);
1556 return;
1557 }
1558
1559 /*
1560 * Don't send probe messages for 4.1 or later.
1561 */
1562 if (!cb->cb_ops && clp->cl_minorversion) {
1563 nfsd4_mark_cb_state(clp, NFSD4_CB_UP);
1564 nfsd41_destroy_cb(cb);
1565 return;
1566 }
1567
1568 if (cb->cb_need_restart) {
1569 cb->cb_need_restart = false;
1570 } else {
1571 if (cb->cb_ops && cb->cb_ops->prepare)
1572 cb->cb_ops->prepare(cb);
1573 }
1574 cb->cb_msg.rpc_cred = clp->cl_cb_cred;
1575 flags = clp->cl_minorversion ? RPC_TASK_NOCONNECT : RPC_TASK_SOFTCONN;
1576 rpc_call_async(clnt, &cb->cb_msg, RPC_TASK_SOFT | flags,
1577 cb->cb_ops ? &nfsd4_cb_ops : &nfsd4_cb_probe_ops, cb);
1578}
1579
1580void nfsd4_init_cb(struct nfsd4_callback *cb, struct nfs4_client *clp,
1581 const struct nfsd4_callback_ops *ops, enum nfsd4_cb_op op)
1582{
1583 cb->cb_clp = clp;
1584 cb->cb_msg.rpc_proc = &nfs4_cb_procedures[op];
1585 cb->cb_msg.rpc_argp = cb;
1586 cb->cb_msg.rpc_resp = cb;
1587 cb->cb_ops = ops;
1588 INIT_WORK(&cb->cb_work, nfsd4_run_cb_work);
1589 cb->cb_status = 0;
1590 cb->cb_need_restart = false;
1591 cb->cb_held_slot = -1;
1592}
1593
1594/**
1595 * nfsd4_run_cb - queue up a callback job to run
1596 * @cb: callback to queue
1597 *
1598 * Kick off a callback to do its thing. Returns false if it was already
1599 * on a queue, true otherwise.
1600 */
1601bool nfsd4_run_cb(struct nfsd4_callback *cb)
1602{
1603 struct nfs4_client *clp = cb->cb_clp;
1604 bool queued;
1605
1606 nfsd41_cb_inflight_begin(clp);
1607 queued = nfsd4_queue_cb(cb);
1608 if (!queued)
1609 nfsd41_cb_inflight_end(clp);
1610 return queued;
1611}