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Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
[deliverable/linux.git] / fs / nfsd / nfs4callback.c
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
45 static 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
52 struct 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 */
65 static 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
72 static __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 */
95 enum 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
111 static 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 */
124 static 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 */
142 static 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 */
156 static 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 */
169 static 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 */
213 static 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
226 static 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;
240 out_overflow:
241 print_overflow_msg(__func__, xdr);
242 return -EIO;
243 out_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 */
259 static 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 */
276 static 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 */
291 static 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;
308 out_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 */
322 static 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 */
351 static 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 */
395 static 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;
437 out:
438 cb->cb_seq_status = status;
439 return status;
440 out_overflow:
441 print_overflow_msg(__func__, xdr);
442 status = -EIO;
443 goto out;
444 }
445
446 static 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 */
473 static 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 */
482 static 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
507 static 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 */
516 static 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 */
563 static 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
589 static 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
606 static 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
640 static 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
648 static 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
661 static const struct rpc_version *nfs_cb_version[] = {
662 &nfs_cb_version4,
663 };
664
665 static const struct rpc_program cb_program;
666
667 static struct rpc_stat cb_stats = {
668 .program = &cb_program
669 };
670
671 #define NFS4_CALLBACK 0x40000000
672 static 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
681 static 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
687 static struct rpc_cred *callback_cred;
688
689 int 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
699 static 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
713 static 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
729 static 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
787 static 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
793 static void nfsd4_mark_cb_down(struct nfs4_client *clp, int reason)
794 {
795 clp->cl_cb_state = NFSD4_CB_DOWN;
796 warn_no_callback_path(clp, reason);
797 }
798
799 static void nfsd4_mark_cb_fault(struct nfs4_client *clp, int reason)
800 {
801 clp->cl_cb_state = NFSD4_CB_FAULT;
802 warn_no_callback_path(clp, reason);
803 }
804
805 static void nfsd4_cb_probe_done(struct rpc_task *task, void *calldata)
806 {
807 struct nfs4_client *clp = container_of(calldata, struct nfs4_client, cl_cb_null);
808
809 if (task->tk_status)
810 nfsd4_mark_cb_down(clp, task->tk_status);
811 else
812 clp->cl_cb_state = NFSD4_CB_UP;
813 }
814
815 static const struct rpc_call_ops nfsd4_cb_probe_ops = {
816 /* XXX: release method to ensure we set the cb channel down if
817 * necessary on early failure? */
818 .rpc_call_done = nfsd4_cb_probe_done,
819 };
820
821 static struct workqueue_struct *callback_wq;
822
823 /*
824 * Poke the callback thread to process any updates to the callback
825 * parameters, and send a null probe.
826 */
827 void nfsd4_probe_callback(struct nfs4_client *clp)
828 {
829 clp->cl_cb_state = NFSD4_CB_UNKNOWN;
830 set_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags);
831 nfsd4_run_cb(&clp->cl_cb_null);
832 }
833
834 void nfsd4_probe_callback_sync(struct nfs4_client *clp)
835 {
836 nfsd4_probe_callback(clp);
837 flush_workqueue(callback_wq);
838 }
839
840 void nfsd4_change_callback(struct nfs4_client *clp, struct nfs4_cb_conn *conn)
841 {
842 clp->cl_cb_state = NFSD4_CB_UNKNOWN;
843 spin_lock(&clp->cl_lock);
844 memcpy(&clp->cl_cb_conn, conn, sizeof(struct nfs4_cb_conn));
845 spin_unlock(&clp->cl_lock);
846 }
847
848 /*
849 * There's currently a single callback channel slot.
850 * If the slot is available, then mark it busy. Otherwise, set the
851 * thread for sleeping on the callback RPC wait queue.
852 */
853 static bool nfsd41_cb_get_slot(struct nfs4_client *clp, struct rpc_task *task)
854 {
855 if (test_and_set_bit(0, &clp->cl_cb_slot_busy) != 0) {
856 rpc_sleep_on(&clp->cl_cb_waitq, task, NULL);
857 /* Race breaker */
858 if (test_and_set_bit(0, &clp->cl_cb_slot_busy) != 0) {
859 dprintk("%s slot is busy\n", __func__);
860 return false;
861 }
862 rpc_wake_up_queued_task(&clp->cl_cb_waitq, task);
863 }
864 return true;
865 }
866
867 /*
868 * TODO: cb_sequence should support referring call lists, cachethis, multiple
869 * slots, and mark callback channel down on communication errors.
870 */
871 static void nfsd4_cb_prepare(struct rpc_task *task, void *calldata)
872 {
873 struct nfsd4_callback *cb = calldata;
874 struct nfs4_client *clp = cb->cb_clp;
875 u32 minorversion = clp->cl_minorversion;
876
877 cb->cb_minorversion = minorversion;
878 /*
879 * cb_seq_status is only set in decode_cb_sequence4res,
880 * and so will remain 1 if an rpc level failure occurs.
881 */
882 cb->cb_seq_status = 1;
883 cb->cb_status = 0;
884 if (minorversion) {
885 if (!nfsd41_cb_get_slot(clp, task))
886 return;
887 }
888 rpc_call_start(task);
889 }
890
891 static bool nfsd4_cb_sequence_done(struct rpc_task *task, struct nfsd4_callback *cb)
892 {
893 struct nfs4_client *clp = cb->cb_clp;
894 struct nfsd4_session *session = clp->cl_cb_session;
895 bool ret = true;
896
897 if (!clp->cl_minorversion) {
898 /*
899 * If the backchannel connection was shut down while this
900 * task was queued, we need to resubmit it after setting up
901 * a new backchannel connection.
902 *
903 * Note that if we lost our callback connection permanently
904 * the submission code will error out, so we don't need to
905 * handle that case here.
906 */
907 if (task->tk_flags & RPC_TASK_KILLED)
908 goto need_restart;
909
910 return true;
911 }
912
913 switch (cb->cb_seq_status) {
914 case 0:
915 /*
916 * No need for lock, access serialized in nfsd4_cb_prepare
917 *
918 * RFC5661 20.9.3
919 * If CB_SEQUENCE returns an error, then the state of the slot
920 * (sequence ID, cached reply) MUST NOT change.
921 */
922 ++session->se_cb_seq_nr;
923 break;
924 case -ESERVERFAULT:
925 ++session->se_cb_seq_nr;
926 case 1:
927 case -NFS4ERR_BADSESSION:
928 nfsd4_mark_cb_fault(cb->cb_clp, cb->cb_seq_status);
929 ret = false;
930 break;
931 case -NFS4ERR_DELAY:
932 if (!rpc_restart_call(task))
933 goto out;
934
935 rpc_delay(task, 2 * HZ);
936 return false;
937 case -NFS4ERR_BADSLOT:
938 goto retry_nowait;
939 case -NFS4ERR_SEQ_MISORDERED:
940 if (session->se_cb_seq_nr != 1) {
941 session->se_cb_seq_nr = 1;
942 goto retry_nowait;
943 }
944 break;
945 default:
946 dprintk("%s: unprocessed error %d\n", __func__,
947 cb->cb_seq_status);
948 }
949
950 clear_bit(0, &clp->cl_cb_slot_busy);
951 rpc_wake_up_next(&clp->cl_cb_waitq);
952 dprintk("%s: freed slot, new seqid=%d\n", __func__,
953 clp->cl_cb_session->se_cb_seq_nr);
954
955 if (task->tk_flags & RPC_TASK_KILLED)
956 goto need_restart;
957 out:
958 return ret;
959 retry_nowait:
960 if (rpc_restart_call_prepare(task))
961 ret = false;
962 goto out;
963 need_restart:
964 task->tk_status = 0;
965 cb->cb_need_restart = true;
966 return false;
967 }
968
969 static void nfsd4_cb_done(struct rpc_task *task, void *calldata)
970 {
971 struct nfsd4_callback *cb = calldata;
972 struct nfs4_client *clp = cb->cb_clp;
973
974 dprintk("%s: minorversion=%d\n", __func__,
975 clp->cl_minorversion);
976
977 if (!nfsd4_cb_sequence_done(task, cb))
978 return;
979
980 if (cb->cb_status) {
981 WARN_ON_ONCE(task->tk_status);
982 task->tk_status = cb->cb_status;
983 }
984
985 switch (cb->cb_ops->done(cb, task)) {
986 case 0:
987 task->tk_status = 0;
988 rpc_restart_call_prepare(task);
989 return;
990 case 1:
991 break;
992 case -1:
993 /* Network partition? */
994 nfsd4_mark_cb_down(clp, task->tk_status);
995 break;
996 default:
997 BUG();
998 }
999 }
1000
1001 static void nfsd4_cb_release(void *calldata)
1002 {
1003 struct nfsd4_callback *cb = calldata;
1004
1005 if (cb->cb_need_restart)
1006 nfsd4_run_cb(cb);
1007 else
1008 cb->cb_ops->release(cb);
1009
1010 }
1011
1012 static const struct rpc_call_ops nfsd4_cb_ops = {
1013 .rpc_call_prepare = nfsd4_cb_prepare,
1014 .rpc_call_done = nfsd4_cb_done,
1015 .rpc_release = nfsd4_cb_release,
1016 };
1017
1018 int nfsd4_create_callback_queue(void)
1019 {
1020 callback_wq = create_singlethread_workqueue("nfsd4_callbacks");
1021 if (!callback_wq)
1022 return -ENOMEM;
1023 return 0;
1024 }
1025
1026 void nfsd4_destroy_callback_queue(void)
1027 {
1028 destroy_workqueue(callback_wq);
1029 }
1030
1031 /* must be called under the state lock */
1032 void nfsd4_shutdown_callback(struct nfs4_client *clp)
1033 {
1034 set_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags);
1035 /*
1036 * Note this won't actually result in a null callback;
1037 * instead, nfsd4_run_cb_null() will detect the killed
1038 * client, destroy the rpc client, and stop:
1039 */
1040 nfsd4_run_cb(&clp->cl_cb_null);
1041 flush_workqueue(callback_wq);
1042 }
1043
1044 /* requires cl_lock: */
1045 static struct nfsd4_conn * __nfsd4_find_backchannel(struct nfs4_client *clp)
1046 {
1047 struct nfsd4_session *s;
1048 struct nfsd4_conn *c;
1049
1050 list_for_each_entry(s, &clp->cl_sessions, se_perclnt) {
1051 list_for_each_entry(c, &s->se_conns, cn_persession) {
1052 if (c->cn_flags & NFS4_CDFC4_BACK)
1053 return c;
1054 }
1055 }
1056 return NULL;
1057 }
1058
1059 static void nfsd4_process_cb_update(struct nfsd4_callback *cb)
1060 {
1061 struct nfs4_cb_conn conn;
1062 struct nfs4_client *clp = cb->cb_clp;
1063 struct nfsd4_session *ses = NULL;
1064 struct nfsd4_conn *c;
1065 int err;
1066
1067 /*
1068 * This is either an update, or the client dying; in either case,
1069 * kill the old client:
1070 */
1071 if (clp->cl_cb_client) {
1072 rpc_shutdown_client(clp->cl_cb_client);
1073 clp->cl_cb_client = NULL;
1074 put_rpccred(clp->cl_cb_cred);
1075 clp->cl_cb_cred = NULL;
1076 }
1077 if (clp->cl_cb_conn.cb_xprt) {
1078 svc_xprt_put(clp->cl_cb_conn.cb_xprt);
1079 clp->cl_cb_conn.cb_xprt = NULL;
1080 }
1081 if (test_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags))
1082 return;
1083 spin_lock(&clp->cl_lock);
1084 /*
1085 * Only serialized callback code is allowed to clear these
1086 * flags; main nfsd code can only set them:
1087 */
1088 BUG_ON(!(clp->cl_flags & NFSD4_CLIENT_CB_FLAG_MASK));
1089 clear_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags);
1090 memcpy(&conn, &cb->cb_clp->cl_cb_conn, sizeof(struct nfs4_cb_conn));
1091 c = __nfsd4_find_backchannel(clp);
1092 if (c) {
1093 svc_xprt_get(c->cn_xprt);
1094 conn.cb_xprt = c->cn_xprt;
1095 ses = c->cn_session;
1096 }
1097 spin_unlock(&clp->cl_lock);
1098
1099 err = setup_callback_client(clp, &conn, ses);
1100 if (err) {
1101 nfsd4_mark_cb_down(clp, err);
1102 return;
1103 }
1104 }
1105
1106 static void
1107 nfsd4_run_cb_work(struct work_struct *work)
1108 {
1109 struct nfsd4_callback *cb =
1110 container_of(work, struct nfsd4_callback, cb_work);
1111 struct nfs4_client *clp = cb->cb_clp;
1112 struct rpc_clnt *clnt;
1113
1114 if (cb->cb_need_restart) {
1115 cb->cb_need_restart = false;
1116 } else {
1117 if (cb->cb_ops && cb->cb_ops->prepare)
1118 cb->cb_ops->prepare(cb);
1119 }
1120
1121 if (clp->cl_flags & NFSD4_CLIENT_CB_FLAG_MASK)
1122 nfsd4_process_cb_update(cb);
1123
1124 clnt = clp->cl_cb_client;
1125 if (!clnt) {
1126 /* Callback channel broken, or client killed; give up: */
1127 if (cb->cb_ops && cb->cb_ops->release)
1128 cb->cb_ops->release(cb);
1129 return;
1130 }
1131
1132 /*
1133 * Don't send probe messages for 4.1 or later.
1134 */
1135 if (!cb->cb_ops && clp->cl_minorversion) {
1136 clp->cl_cb_state = NFSD4_CB_UP;
1137 return;
1138 }
1139
1140 cb->cb_msg.rpc_cred = clp->cl_cb_cred;
1141 rpc_call_async(clnt, &cb->cb_msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN,
1142 cb->cb_ops ? &nfsd4_cb_ops : &nfsd4_cb_probe_ops, cb);
1143 }
1144
1145 void nfsd4_init_cb(struct nfsd4_callback *cb, struct nfs4_client *clp,
1146 struct nfsd4_callback_ops *ops, enum nfsd4_cb_op op)
1147 {
1148 cb->cb_clp = clp;
1149 cb->cb_msg.rpc_proc = &nfs4_cb_procedures[op];
1150 cb->cb_msg.rpc_argp = cb;
1151 cb->cb_msg.rpc_resp = cb;
1152 cb->cb_ops = ops;
1153 INIT_WORK(&cb->cb_work, nfsd4_run_cb_work);
1154 cb->cb_seq_status = 1;
1155 cb->cb_status = 0;
1156 cb->cb_need_restart = false;
1157 }
1158
1159 void nfsd4_run_cb(struct nfsd4_callback *cb)
1160 {
1161 queue_work(callback_wq, &cb->cb_work);
1162 }
Linux kernel - Deliverables
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