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