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PM / devfreq: exynos-ppmu: Update documentation to support PPMUv2
[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 if (status)
439 nfsd4_mark_cb_fault(cb->cb_clp, status);
440 return status;
441 out_overflow:
442 print_overflow_msg(__func__, xdr);
443 return -EIO;
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_status);
455 if (unlikely(status || cb->cb_status))
456 return status;
457
458 cb->cb_update_seq_nr = true;
459 return decode_cb_sequence4resok(xdr, cb);
460 }
461
462 /*
463 * NFSv4.0 and NFSv4.1 XDR encode functions
464 *
465 * NFSv4.0 callback argument types are defined in section 15 of RFC
466 * 3530: "Network File System (NFS) version 4 Protocol" and section 20
467 * of RFC 5661: "Network File System (NFS) Version 4 Minor Version 1
468 * Protocol".
469 */
470
471 /*
472 * NB: Without this zero space reservation, callbacks over krb5p fail
473 */
474 static void nfs4_xdr_enc_cb_null(struct rpc_rqst *req, struct xdr_stream *xdr,
475 void *__unused)
476 {
477 xdr_reserve_space(xdr, 0);
478 }
479
480 /*
481 * 20.2. Operation 4: CB_RECALL - Recall a Delegation
482 */
483 static void nfs4_xdr_enc_cb_recall(struct rpc_rqst *req, struct xdr_stream *xdr,
484 const struct nfsd4_callback *cb)
485 {
486 const struct nfs4_delegation *dp = cb_to_delegation(cb);
487 struct nfs4_cb_compound_hdr hdr = {
488 .ident = cb->cb_clp->cl_cb_ident,
489 .minorversion = cb->cb_minorversion,
490 };
491
492 encode_cb_compound4args(xdr, &hdr);
493 encode_cb_sequence4args(xdr, cb, &hdr);
494 encode_cb_recall4args(xdr, dp, &hdr);
495 encode_cb_nops(&hdr);
496 }
497
498
499 /*
500 * NFSv4.0 and NFSv4.1 XDR decode functions
501 *
502 * NFSv4.0 callback result types are defined in section 15 of RFC
503 * 3530: "Network File System (NFS) version 4 Protocol" and section 20
504 * of RFC 5661: "Network File System (NFS) Version 4 Minor Version 1
505 * Protocol".
506 */
507
508 static int nfs4_xdr_dec_cb_null(struct rpc_rqst *req, struct xdr_stream *xdr,
509 void *__unused)
510 {
511 return 0;
512 }
513
514 /*
515 * 20.2. Operation 4: CB_RECALL - Recall a Delegation
516 */
517 static int nfs4_xdr_dec_cb_recall(struct rpc_rqst *rqstp,
518 struct xdr_stream *xdr,
519 struct nfsd4_callback *cb)
520 {
521 struct nfs4_cb_compound_hdr hdr;
522 int status;
523
524 status = decode_cb_compound4res(xdr, &hdr);
525 if (unlikely(status))
526 return status;
527
528 if (cb != NULL) {
529 status = decode_cb_sequence4res(xdr, cb);
530 if (unlikely(status || cb->cb_status))
531 return status;
532 }
533
534 return decode_cb_op_status(xdr, OP_CB_RECALL, &cb->cb_status);
535 }
536
537 #ifdef CONFIG_NFSD_PNFS
538 /*
539 * CB_LAYOUTRECALL4args
540 *
541 * struct layoutrecall_file4 {
542 * nfs_fh4 lor_fh;
543 * offset4 lor_offset;
544 * length4 lor_length;
545 * stateid4 lor_stateid;
546 * };
547 *
548 * union layoutrecall4 switch(layoutrecall_type4 lor_recalltype) {
549 * case LAYOUTRECALL4_FILE:
550 * layoutrecall_file4 lor_layout;
551 * case LAYOUTRECALL4_FSID:
552 * fsid4 lor_fsid;
553 * case LAYOUTRECALL4_ALL:
554 * void;
555 * };
556 *
557 * struct CB_LAYOUTRECALL4args {
558 * layouttype4 clora_type;
559 * layoutiomode4 clora_iomode;
560 * bool clora_changed;
561 * layoutrecall4 clora_recall;
562 * };
563 */
564 static void encode_cb_layout4args(struct xdr_stream *xdr,
565 const struct nfs4_layout_stateid *ls,
566 struct nfs4_cb_compound_hdr *hdr)
567 {
568 __be32 *p;
569
570 BUG_ON(hdr->minorversion == 0);
571
572 p = xdr_reserve_space(xdr, 5 * 4);
573 *p++ = cpu_to_be32(OP_CB_LAYOUTRECALL);
574 *p++ = cpu_to_be32(ls->ls_layout_type);
575 *p++ = cpu_to_be32(IOMODE_ANY);
576 *p++ = cpu_to_be32(1);
577 *p = cpu_to_be32(RETURN_FILE);
578
579 encode_nfs_fh4(xdr, &ls->ls_stid.sc_file->fi_fhandle);
580
581 p = xdr_reserve_space(xdr, 2 * 8);
582 p = xdr_encode_hyper(p, 0);
583 xdr_encode_hyper(p, NFS4_MAX_UINT64);
584
585 encode_stateid4(xdr, &ls->ls_recall_sid);
586
587 hdr->nops++;
588 }
589
590 static void nfs4_xdr_enc_cb_layout(struct rpc_rqst *req,
591 struct xdr_stream *xdr,
592 const struct nfsd4_callback *cb)
593 {
594 const struct nfs4_layout_stateid *ls =
595 container_of(cb, struct nfs4_layout_stateid, ls_recall);
596 struct nfs4_cb_compound_hdr hdr = {
597 .ident = 0,
598 .minorversion = cb->cb_minorversion,
599 };
600
601 encode_cb_compound4args(xdr, &hdr);
602 encode_cb_sequence4args(xdr, cb, &hdr);
603 encode_cb_layout4args(xdr, ls, &hdr);
604 encode_cb_nops(&hdr);
605 }
606
607 static int nfs4_xdr_dec_cb_layout(struct rpc_rqst *rqstp,
608 struct xdr_stream *xdr,
609 struct nfsd4_callback *cb)
610 {
611 struct nfs4_cb_compound_hdr hdr;
612 int status;
613
614 status = decode_cb_compound4res(xdr, &hdr);
615 if (unlikely(status))
616 return status;
617
618 if (cb) {
619 status = decode_cb_sequence4res(xdr, cb);
620 if (unlikely(status || cb->cb_status))
621 return status;
622 }
623 return decode_cb_op_status(xdr, OP_CB_LAYOUTRECALL, &cb->cb_status);
624 }
625 #endif /* CONFIG_NFSD_PNFS */
626
627 /*
628 * RPC procedure tables
629 */
630 #define PROC(proc, call, argtype, restype) \
631 [NFSPROC4_CLNT_##proc] = { \
632 .p_proc = NFSPROC4_CB_##call, \
633 .p_encode = (kxdreproc_t)nfs4_xdr_enc_##argtype, \
634 .p_decode = (kxdrdproc_t)nfs4_xdr_dec_##restype, \
635 .p_arglen = NFS4_enc_##argtype##_sz, \
636 .p_replen = NFS4_dec_##restype##_sz, \
637 .p_statidx = NFSPROC4_CB_##call, \
638 .p_name = #proc, \
639 }
640
641 static struct rpc_procinfo nfs4_cb_procedures[] = {
642 PROC(CB_NULL, NULL, cb_null, cb_null),
643 PROC(CB_RECALL, COMPOUND, cb_recall, cb_recall),
644 #ifdef CONFIG_NFSD_PNFS
645 PROC(CB_LAYOUT, COMPOUND, cb_layout, cb_layout),
646 #endif
647 };
648
649 static struct rpc_version nfs_cb_version4 = {
650 /*
651 * Note on the callback rpc program version number: despite language in rfc
652 * 5661 section 18.36.3 requiring servers to use 4 in this field, the
653 * official xdr descriptions for both 4.0 and 4.1 specify version 1, and
654 * in practice that appears to be what implementations use. The section
655 * 18.36.3 language is expected to be fixed in an erratum.
656 */
657 .number = 1,
658 .nrprocs = ARRAY_SIZE(nfs4_cb_procedures),
659 .procs = nfs4_cb_procedures
660 };
661
662 static const struct rpc_version *nfs_cb_version[] = {
663 &nfs_cb_version4,
664 };
665
666 static const struct rpc_program cb_program;
667
668 static struct rpc_stat cb_stats = {
669 .program = &cb_program
670 };
671
672 #define NFS4_CALLBACK 0x40000000
673 static const struct rpc_program cb_program = {
674 .name = "nfs4_cb",
675 .number = NFS4_CALLBACK,
676 .nrvers = ARRAY_SIZE(nfs_cb_version),
677 .version = nfs_cb_version,
678 .stats = &cb_stats,
679 .pipe_dir_name = "nfsd4_cb",
680 };
681
682 static int max_cb_time(struct net *net)
683 {
684 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
685 return max(nn->nfsd4_lease/10, (time_t)1) * HZ;
686 }
687
688 static struct rpc_cred *callback_cred;
689
690 int set_callback_cred(void)
691 {
692 if (callback_cred)
693 return 0;
694 callback_cred = rpc_lookup_machine_cred("nfs");
695 if (!callback_cred)
696 return -ENOMEM;
697 return 0;
698 }
699
700 static struct rpc_cred *get_backchannel_cred(struct nfs4_client *clp, struct rpc_clnt *client, struct nfsd4_session *ses)
701 {
702 if (clp->cl_minorversion == 0) {
703 return get_rpccred(callback_cred);
704 } else {
705 struct rpc_auth *auth = client->cl_auth;
706 struct auth_cred acred = {};
707
708 acred.uid = ses->se_cb_sec.uid;
709 acred.gid = ses->se_cb_sec.gid;
710 return auth->au_ops->lookup_cred(client->cl_auth, &acred, 0);
711 }
712 }
713
714 static struct rpc_clnt *create_backchannel_client(struct rpc_create_args *args)
715 {
716 struct rpc_xprt *xprt;
717
718 if (args->protocol != XPRT_TRANSPORT_BC_TCP)
719 return rpc_create(args);
720
721 xprt = args->bc_xprt->xpt_bc_xprt;
722 if (xprt) {
723 xprt_get(xprt);
724 return rpc_create_xprt(args, xprt);
725 }
726
727 return rpc_create(args);
728 }
729
730 static int setup_callback_client(struct nfs4_client *clp, struct nfs4_cb_conn *conn, struct nfsd4_session *ses)
731 {
732 int maxtime = max_cb_time(clp->net);
733 struct rpc_timeout timeparms = {
734 .to_initval = maxtime,
735 .to_retries = 0,
736 .to_maxval = maxtime,
737 };
738 struct rpc_create_args args = {
739 .net = clp->net,
740 .address = (struct sockaddr *) &conn->cb_addr,
741 .addrsize = conn->cb_addrlen,
742 .saddress = (struct sockaddr *) &conn->cb_saddr,
743 .timeout = &timeparms,
744 .program = &cb_program,
745 .version = 0,
746 .flags = (RPC_CLNT_CREATE_NOPING | RPC_CLNT_CREATE_QUIET),
747 };
748 struct rpc_clnt *client;
749 struct rpc_cred *cred;
750
751 if (clp->cl_minorversion == 0) {
752 if (!clp->cl_cred.cr_principal &&
753 (clp->cl_cred.cr_flavor >= RPC_AUTH_GSS_KRB5))
754 return -EINVAL;
755 args.client_name = clp->cl_cred.cr_principal;
756 args.prognumber = conn->cb_prog;
757 args.protocol = XPRT_TRANSPORT_TCP;
758 args.authflavor = clp->cl_cred.cr_flavor;
759 clp->cl_cb_ident = conn->cb_ident;
760 } else {
761 if (!conn->cb_xprt)
762 return -EINVAL;
763 clp->cl_cb_conn.cb_xprt = conn->cb_xprt;
764 clp->cl_cb_session = ses;
765 args.bc_xprt = conn->cb_xprt;
766 args.prognumber = clp->cl_cb_session->se_cb_prog;
767 args.protocol = conn->cb_xprt->xpt_class->xcl_ident |
768 XPRT_TRANSPORT_BC;
769 args.authflavor = ses->se_cb_sec.flavor;
770 }
771 /* Create RPC client */
772 client = create_backchannel_client(&args);
773 if (IS_ERR(client)) {
774 dprintk("NFSD: couldn't create callback client: %ld\n",
775 PTR_ERR(client));
776 return PTR_ERR(client);
777 }
778 cred = get_backchannel_cred(clp, client, ses);
779 if (IS_ERR(cred)) {
780 rpc_shutdown_client(client);
781 return PTR_ERR(cred);
782 }
783 clp->cl_cb_client = client;
784 clp->cl_cb_cred = cred;
785 return 0;
786 }
787
788 static void warn_no_callback_path(struct nfs4_client *clp, int reason)
789 {
790 dprintk("NFSD: warning: no callback path to client %.*s: error %d\n",
791 (int)clp->cl_name.len, clp->cl_name.data, reason);
792 }
793
794 static void nfsd4_mark_cb_down(struct nfs4_client *clp, int reason)
795 {
796 clp->cl_cb_state = NFSD4_CB_DOWN;
797 warn_no_callback_path(clp, reason);
798 }
799
800 static void nfsd4_mark_cb_fault(struct nfs4_client *clp, int reason)
801 {
802 clp->cl_cb_state = NFSD4_CB_FAULT;
803 warn_no_callback_path(clp, reason);
804 }
805
806 static void nfsd4_cb_probe_done(struct rpc_task *task, void *calldata)
807 {
808 struct nfs4_client *clp = container_of(calldata, struct nfs4_client, cl_cb_null);
809
810 if (task->tk_status)
811 nfsd4_mark_cb_down(clp, task->tk_status);
812 else
813 clp->cl_cb_state = NFSD4_CB_UP;
814 }
815
816 static const struct rpc_call_ops nfsd4_cb_probe_ops = {
817 /* XXX: release method to ensure we set the cb channel down if
818 * necessary on early failure? */
819 .rpc_call_done = nfsd4_cb_probe_done,
820 };
821
822 static struct workqueue_struct *callback_wq;
823
824 /*
825 * Poke the callback thread to process any updates to the callback
826 * parameters, and send a null probe.
827 */
828 void nfsd4_probe_callback(struct nfs4_client *clp)
829 {
830 clp->cl_cb_state = NFSD4_CB_UNKNOWN;
831 set_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags);
832 nfsd4_run_cb(&clp->cl_cb_null);
833 }
834
835 void nfsd4_probe_callback_sync(struct nfs4_client *clp)
836 {
837 nfsd4_probe_callback(clp);
838 flush_workqueue(callback_wq);
839 }
840
841 void nfsd4_change_callback(struct nfs4_client *clp, struct nfs4_cb_conn *conn)
842 {
843 clp->cl_cb_state = NFSD4_CB_UNKNOWN;
844 spin_lock(&clp->cl_lock);
845 memcpy(&clp->cl_cb_conn, conn, sizeof(struct nfs4_cb_conn));
846 spin_unlock(&clp->cl_lock);
847 }
848
849 /*
850 * There's currently a single callback channel slot.
851 * If the slot is available, then mark it busy. Otherwise, set the
852 * thread for sleeping on the callback RPC wait queue.
853 */
854 static bool nfsd41_cb_get_slot(struct nfs4_client *clp, struct rpc_task *task)
855 {
856 if (test_and_set_bit(0, &clp->cl_cb_slot_busy) != 0) {
857 rpc_sleep_on(&clp->cl_cb_waitq, task, NULL);
858 /* Race breaker */
859 if (test_and_set_bit(0, &clp->cl_cb_slot_busy) != 0) {
860 dprintk("%s slot is busy\n", __func__);
861 return false;
862 }
863 rpc_wake_up_queued_task(&clp->cl_cb_waitq, task);
864 }
865 return true;
866 }
867
868 /*
869 * TODO: cb_sequence should support referring call lists, cachethis, multiple
870 * slots, and mark callback channel down on communication errors.
871 */
872 static void nfsd4_cb_prepare(struct rpc_task *task, void *calldata)
873 {
874 struct nfsd4_callback *cb = calldata;
875 struct nfs4_client *clp = cb->cb_clp;
876 u32 minorversion = clp->cl_minorversion;
877
878 cb->cb_minorversion = minorversion;
879 cb->cb_update_seq_nr = false;
880 cb->cb_status = 0;
881 if (minorversion) {
882 if (!nfsd41_cb_get_slot(clp, task))
883 return;
884 }
885 rpc_call_start(task);
886 }
887
888 static void nfsd4_cb_done(struct rpc_task *task, void *calldata)
889 {
890 struct nfsd4_callback *cb = calldata;
891 struct nfs4_client *clp = cb->cb_clp;
892
893 dprintk("%s: minorversion=%d\n", __func__,
894 clp->cl_minorversion);
895
896 if (clp->cl_minorversion) {
897 /*
898 * No need for lock, access serialized in nfsd4_cb_prepare
899 *
900 * RFC5661 20.9.3
901 * If CB_SEQUENCE returns an error, then the state of the slot
902 * (sequence ID, cached reply) MUST NOT change.
903 */
904 if (cb->cb_update_seq_nr)
905 ++clp->cl_cb_session->se_cb_seq_nr;
906
907 clear_bit(0, &clp->cl_cb_slot_busy);
908 rpc_wake_up_next(&clp->cl_cb_waitq);
909 dprintk("%s: freed slot, new seqid=%d\n", __func__,
910 clp->cl_cb_session->se_cb_seq_nr);
911 }
912
913 /*
914 * If the backchannel connection was shut down while this
915 * task was queued, we need to resubmit it after setting up
916 * a new backchannel connection.
917 *
918 * Note that if we lost our callback connection permanently
919 * the submission code will error out, so we don't need to
920 * handle that case here.
921 */
922 if (task->tk_flags & RPC_TASK_KILLED) {
923 task->tk_status = 0;
924 cb->cb_need_restart = true;
925 return;
926 }
927
928 if (cb->cb_status) {
929 WARN_ON_ONCE(task->tk_status);
930 task->tk_status = cb->cb_status;
931 }
932
933 switch (cb->cb_ops->done(cb, task)) {
934 case 0:
935 task->tk_status = 0;
936 rpc_restart_call_prepare(task);
937 return;
938 case 1:
939 break;
940 case -1:
941 /* Network partition? */
942 nfsd4_mark_cb_down(clp, task->tk_status);
943 break;
944 default:
945 BUG();
946 }
947 }
948
949 static void nfsd4_cb_release(void *calldata)
950 {
951 struct nfsd4_callback *cb = calldata;
952
953 if (cb->cb_need_restart)
954 nfsd4_run_cb(cb);
955 else
956 cb->cb_ops->release(cb);
957
958 }
959
960 static const struct rpc_call_ops nfsd4_cb_ops = {
961 .rpc_call_prepare = nfsd4_cb_prepare,
962 .rpc_call_done = nfsd4_cb_done,
963 .rpc_release = nfsd4_cb_release,
964 };
965
966 int nfsd4_create_callback_queue(void)
967 {
968 callback_wq = create_singlethread_workqueue("nfsd4_callbacks");
969 if (!callback_wq)
970 return -ENOMEM;
971 return 0;
972 }
973
974 void nfsd4_destroy_callback_queue(void)
975 {
976 destroy_workqueue(callback_wq);
977 }
978
979 /* must be called under the state lock */
980 void nfsd4_shutdown_callback(struct nfs4_client *clp)
981 {
982 set_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags);
983 /*
984 * Note this won't actually result in a null callback;
985 * instead, nfsd4_run_cb_null() will detect the killed
986 * client, destroy the rpc client, and stop:
987 */
988 nfsd4_run_cb(&clp->cl_cb_null);
989 flush_workqueue(callback_wq);
990 }
991
992 /* requires cl_lock: */
993 static struct nfsd4_conn * __nfsd4_find_backchannel(struct nfs4_client *clp)
994 {
995 struct nfsd4_session *s;
996 struct nfsd4_conn *c;
997
998 list_for_each_entry(s, &clp->cl_sessions, se_perclnt) {
999 list_for_each_entry(c, &s->se_conns, cn_persession) {
1000 if (c->cn_flags & NFS4_CDFC4_BACK)
1001 return c;
1002 }
1003 }
1004 return NULL;
1005 }
1006
1007 static void nfsd4_process_cb_update(struct nfsd4_callback *cb)
1008 {
1009 struct nfs4_cb_conn conn;
1010 struct nfs4_client *clp = cb->cb_clp;
1011 struct nfsd4_session *ses = NULL;
1012 struct nfsd4_conn *c;
1013 int err;
1014
1015 /*
1016 * This is either an update, or the client dying; in either case,
1017 * kill the old client:
1018 */
1019 if (clp->cl_cb_client) {
1020 rpc_shutdown_client(clp->cl_cb_client);
1021 clp->cl_cb_client = NULL;
1022 put_rpccred(clp->cl_cb_cred);
1023 clp->cl_cb_cred = NULL;
1024 }
1025 if (clp->cl_cb_conn.cb_xprt) {
1026 svc_xprt_put(clp->cl_cb_conn.cb_xprt);
1027 clp->cl_cb_conn.cb_xprt = NULL;
1028 }
1029 if (test_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags))
1030 return;
1031 spin_lock(&clp->cl_lock);
1032 /*
1033 * Only serialized callback code is allowed to clear these
1034 * flags; main nfsd code can only set them:
1035 */
1036 BUG_ON(!(clp->cl_flags & NFSD4_CLIENT_CB_FLAG_MASK));
1037 clear_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags);
1038 memcpy(&conn, &cb->cb_clp->cl_cb_conn, sizeof(struct nfs4_cb_conn));
1039 c = __nfsd4_find_backchannel(clp);
1040 if (c) {
1041 svc_xprt_get(c->cn_xprt);
1042 conn.cb_xprt = c->cn_xprt;
1043 ses = c->cn_session;
1044 }
1045 spin_unlock(&clp->cl_lock);
1046
1047 err = setup_callback_client(clp, &conn, ses);
1048 if (err) {
1049 nfsd4_mark_cb_down(clp, err);
1050 return;
1051 }
1052 }
1053
1054 static void
1055 nfsd4_run_cb_work(struct work_struct *work)
1056 {
1057 struct nfsd4_callback *cb =
1058 container_of(work, struct nfsd4_callback, cb_work);
1059 struct nfs4_client *clp = cb->cb_clp;
1060 struct rpc_clnt *clnt;
1061
1062 if (cb->cb_need_restart) {
1063 cb->cb_need_restart = false;
1064 } else {
1065 if (cb->cb_ops && cb->cb_ops->prepare)
1066 cb->cb_ops->prepare(cb);
1067 }
1068
1069 if (clp->cl_flags & NFSD4_CLIENT_CB_FLAG_MASK)
1070 nfsd4_process_cb_update(cb);
1071
1072 clnt = clp->cl_cb_client;
1073 if (!clnt) {
1074 /* Callback channel broken, or client killed; give up: */
1075 if (cb->cb_ops && cb->cb_ops->release)
1076 cb->cb_ops->release(cb);
1077 return;
1078 }
1079
1080 /*
1081 * Don't send probe messages for 4.1 or later.
1082 */
1083 if (!cb->cb_ops && clp->cl_minorversion) {
1084 clp->cl_cb_state = NFSD4_CB_UP;
1085 return;
1086 }
1087
1088 cb->cb_msg.rpc_cred = clp->cl_cb_cred;
1089 rpc_call_async(clnt, &cb->cb_msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN,
1090 cb->cb_ops ? &nfsd4_cb_ops : &nfsd4_cb_probe_ops, cb);
1091 }
1092
1093 void nfsd4_init_cb(struct nfsd4_callback *cb, struct nfs4_client *clp,
1094 struct nfsd4_callback_ops *ops, enum nfsd4_cb_op op)
1095 {
1096 cb->cb_clp = clp;
1097 cb->cb_msg.rpc_proc = &nfs4_cb_procedures[op];
1098 cb->cb_msg.rpc_argp = cb;
1099 cb->cb_msg.rpc_resp = cb;
1100 cb->cb_ops = ops;
1101 INIT_WORK(&cb->cb_work, nfsd4_run_cb_work);
1102 cb->cb_status = 0;
1103 cb->cb_update_seq_nr = false;
1104 cb->cb_need_restart = false;
1105 }
1106
1107 void nfsd4_run_cb(struct nfsd4_callback *cb)
1108 {
1109 queue_work(callback_wq, &cb->cb_work);
1110 }
Linux kernel - Deliverables
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