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printf: Remove unused 'bprintf'
[drm/drm-misc.git] / fs / nfsd / nfs4callback.c
blob3877b53e429fd89899d7dc35086bee8bda6eed07
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
48 static 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
55 struct 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
65 static __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
80 static void encode_uint32(struct xdr_stream *xdr, u32 n)
81 {
82 WARN_ON_ONCE(xdr_stream_encode_u32(xdr, n) < 0);
83 }
84
85 static 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
91 static 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
105 static 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 */
118 static 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 */
136 static 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 */
150 static 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 */
163 static 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 */
207 static 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
220 static 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;
234 out_overflow:
235 return -EIO;
236 out_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 */
252 static 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 */
269 static 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 */
284 static 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;
302 out_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 */
315 static 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 */
340 static void
341 encode_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 */
360 static void
361 encode_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
377 static 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 */
402 static 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
425 static 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 */
471 static 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;
510 out:
511 cb->cb_seq_status = status;
512 return status;
513 out_overflow:
514 status = -EIO;
515 goto out;
516 }
517
518 static 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 */
545 static 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 */
554 static 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 */
574 static 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 */
593 static void
594 nfs4_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
620 static 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 */
629 static 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 */
665 static 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 */
687 static int
688 nfs4_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 */
733 static 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
759 static 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
777 static 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
797 static 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
806 static 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
835 static 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 */
873 static 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
896 static 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
911 static 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
929 static 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
961 static 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
973 static unsigned int nfs4_cb_counts[ARRAY_SIZE(nfs4_cb_procedures)];
974 static 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
988 static const struct rpc_version *nfs_cb_version[2] = {
989 [1] = &nfs_cb_version4,
990 };
991
992 static const struct rpc_program cb_program;
993
994 static struct rpc_stat cb_stats = {
995 .program = &cb_program
996 };
997
998 #define NFS4_CALLBACK 0x40000000
999 static 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
1008 static 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
1023 static 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
1031 static void nfsd41_cb_inflight_begin(struct nfs4_client *clp)
1032 {
1033 atomic_inc(&clp->cl_cb_inflight);
1034 }
1035
1036 static 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
1043 static 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
1049 static 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
1069 static 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)
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
1136 static 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
1144 static 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
1151 static 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
1158 static 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
1168 static 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
1176 static 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 */
1187 void 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
1195 void nfsd4_probe_callback_sync(struct nfs4_client *clp)
1196 {
1197 nfsd4_probe_callback(clp);
1198 flush_workqueue(clp->cl_callback_wq);
1199 }
1200
1201 void 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
1209 static 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 */
1230 static 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
1249 static 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
1263 static 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 */
1278 static 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
1296 static 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;
1374 out:
1375 return ret;
1376 retry_nowait:
1377 if (rpc_restart_call_prepare(task))
1378 ret = false;
1379 goto out;
1380 need_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
1389 static 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
1423 static 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
1436 static 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 */
1443 void 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
1459 static 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 */
1481 static 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 if (!c)
1526 return;
1527
1528 err = setup_callback_client(clp, &conn, ses);
1529 if (err) {
1530 nfsd4_mark_cb_down(clp);
1531 if (c)
1532 svc_xprt_put(c->cn_xprt);
1533 return;
1534 }
1535 }
1536
1537 static void
1538 nfsd4_run_cb_work(struct work_struct *work)
1539 {
1540 struct nfsd4_callback *cb =
1541 container_of(work, struct nfsd4_callback, cb_work);
1542 struct nfs4_client *clp = cb->cb_clp;
1543 struct rpc_clnt *clnt;
1544 int flags;
1545
1546 trace_nfsd_cb_start(clp);
1547
1548 if (clp->cl_flags & NFSD4_CLIENT_CB_FLAG_MASK)
1549 nfsd4_process_cb_update(cb);
1550
1551 clnt = clp->cl_cb_client;
1552 if (!clnt) {
1553 /* Callback channel broken, or client killed; give up: */
1554 nfsd41_destroy_cb(cb);
1555 return;
1556 }
1557
1558 /*
1559 * Don't send probe messages for 4.1 or later.
1560 */
1561 if (!cb->cb_ops && clp->cl_minorversion) {
1562 nfsd4_mark_cb_state(clp, NFSD4_CB_UP);
1563 nfsd41_destroy_cb(cb);
1564 return;
1565 }
1566
1567 if (cb->cb_need_restart) {
1568 cb->cb_need_restart = false;
1569 } else {
1570 if (cb->cb_ops && cb->cb_ops->prepare)
1571 cb->cb_ops->prepare(cb);
1572 }
1573 cb->cb_msg.rpc_cred = clp->cl_cb_cred;
1574 flags = clp->cl_minorversion ? RPC_TASK_NOCONNECT : RPC_TASK_SOFTCONN;
1575 rpc_call_async(clnt, &cb->cb_msg, RPC_TASK_SOFT | flags,
1576 cb->cb_ops ? &nfsd4_cb_ops : &nfsd4_cb_probe_ops, cb);
1577 }
1578
1579 void nfsd4_init_cb(struct nfsd4_callback *cb, struct nfs4_client *clp,
1580 const struct nfsd4_callback_ops *ops, enum nfsd4_cb_op op)
1581 {
1582 cb->cb_clp = clp;
1583 cb->cb_msg.rpc_proc = &nfs4_cb_procedures[op];
1584 cb->cb_msg.rpc_argp = cb;
1585 cb->cb_msg.rpc_resp = cb;
1586 cb->cb_ops = ops;
1587 INIT_WORK(&cb->cb_work, nfsd4_run_cb_work);
1588 cb->cb_status = 0;
1589 cb->cb_need_restart = false;
1590 cb->cb_held_slot = -1;
1591 }
1592
1593 /**
1594 * nfsd4_run_cb - queue up a callback job to run
1595 * @cb: callback to queue
1596 *
1597 * Kick off a callback to do its thing. Returns false if it was already
1598 * on a queue, true otherwise.
1599 */
1600 bool nfsd4_run_cb(struct nfsd4_callback *cb)
1601 {
1602 struct nfs4_client *clp = cb->cb_clp;
1603 bool queued;
1604
1605 nfsd41_cb_inflight_begin(clp);
1606 queued = nfsd4_queue_cb(cb);
1607 if (!queued)
1608 nfsd41_cb_inflight_end(clp);
1609 return queued;
1610 }
Kernel DRM miscellaneous fixes and cross-tree changes