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NFSD: Update XDR encoders in NFSv4 callback client
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / fs / nfsd / nfs4callback.c
blobd8148cc461e771c4a427fe6180555a12558f6ca5
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/svc_xprt.h>
36 #include <linux/slab.h>
37 #include "nfsd.h"
38 #include "state.h"
39
40 #define NFSDDBG_FACILITY NFSDDBG_PROC
41
42 #define NFSPROC4_CB_NULL 0
43 #define NFSPROC4_CB_COMPOUND 1
44
45 /* Index of predefined Linux callback client operations */
46
47 enum {
48 NFSPROC4_CLNT_CB_NULL = 0,
49 NFSPROC4_CLNT_CB_RECALL,
50 NFSPROC4_CLNT_CB_SEQUENCE,
51 };
52
53 #define NFS4_MAXTAGLEN 20
54
55 #define NFS4_enc_cb_null_sz 0
56 #define NFS4_dec_cb_null_sz 0
57 #define cb_compound_enc_hdr_sz 4
58 #define cb_compound_dec_hdr_sz (3 + (NFS4_MAXTAGLEN >> 2))
59 #define sessionid_sz (NFS4_MAX_SESSIONID_LEN >> 2)
60 #define cb_sequence_enc_sz (sessionid_sz + 4 + \
61 1 /* no referring calls list yet */)
62 #define cb_sequence_dec_sz (op_dec_sz + sessionid_sz + 4)
63
64 #define op_enc_sz 1
65 #define op_dec_sz 2
66 #define enc_nfs4_fh_sz (1 + (NFS4_FHSIZE >> 2))
67 #define enc_stateid_sz (NFS4_STATEID_SIZE >> 2)
68 #define NFS4_enc_cb_recall_sz (cb_compound_enc_hdr_sz + \
69 cb_sequence_enc_sz + \
70 1 + enc_stateid_sz + \
71 enc_nfs4_fh_sz)
72
73 #define NFS4_dec_cb_recall_sz (cb_compound_dec_hdr_sz + \
74 cb_sequence_dec_sz + \
75 op_dec_sz)
76
77 /*
78 * Generic decode routines from fs/nfs/nfs4xdr.c
79 */
80 #define DECODE_TAIL \
81 status = 0; \
82 out: \
83 return status; \
84 xdr_error: \
85 dprintk("NFSD: xdr error! (%s:%d)\n", __FILE__, __LINE__); \
86 status = -EIO; \
87 goto out
88
89 #define READ32(x) (x) = ntohl(*p++)
90 #define READ64(x) do { \
91 (x) = (u64)ntohl(*p++) << 32; \
92 (x) |= ntohl(*p++); \
93 } while (0)
94 #define READTIME(x) do { \
95 p++; \
96 (x.tv_sec) = ntohl(*p++); \
97 (x.tv_nsec) = ntohl(*p++); \
98 } while (0)
99 #define READ_BUF(nbytes) do { \
100 p = xdr_inline_decode(xdr, nbytes); \
101 if (!p) { \
102 dprintk("NFSD: %s: reply buffer overflowed in line %d.\n", \
103 __func__, __LINE__); \
104 return -EIO; \
105 } \
106 } while (0)
107
108 struct nfs4_cb_compound_hdr {
109 /* args */
110 u32 ident; /* minorversion 0 only */
111 u32 nops;
112 __be32 *nops_p;
113 u32 minorversion;
114 /* res */
115 int status;
116 };
117
118 static struct {
119 int stat;
120 int errno;
121 } nfs_cb_errtbl[] = {
122 { NFS4_OK, 0 },
123 { NFS4ERR_PERM, EPERM },
124 { NFS4ERR_NOENT, ENOENT },
125 { NFS4ERR_IO, EIO },
126 { NFS4ERR_NXIO, ENXIO },
127 { NFS4ERR_ACCESS, EACCES },
128 { NFS4ERR_EXIST, EEXIST },
129 { NFS4ERR_XDEV, EXDEV },
130 { NFS4ERR_NOTDIR, ENOTDIR },
131 { NFS4ERR_ISDIR, EISDIR },
132 { NFS4ERR_INVAL, EINVAL },
133 { NFS4ERR_FBIG, EFBIG },
134 { NFS4ERR_NOSPC, ENOSPC },
135 { NFS4ERR_ROFS, EROFS },
136 { NFS4ERR_MLINK, EMLINK },
137 { NFS4ERR_NAMETOOLONG, ENAMETOOLONG },
138 { NFS4ERR_NOTEMPTY, ENOTEMPTY },
139 { NFS4ERR_DQUOT, EDQUOT },
140 { NFS4ERR_STALE, ESTALE },
141 { NFS4ERR_BADHANDLE, EBADHANDLE },
142 { NFS4ERR_BAD_COOKIE, EBADCOOKIE },
143 { NFS4ERR_NOTSUPP, ENOTSUPP },
144 { NFS4ERR_TOOSMALL, ETOOSMALL },
145 { NFS4ERR_SERVERFAULT, ESERVERFAULT },
146 { NFS4ERR_BADTYPE, EBADTYPE },
147 { NFS4ERR_LOCKED, EAGAIN },
148 { NFS4ERR_RESOURCE, EREMOTEIO },
149 { NFS4ERR_SYMLINK, ELOOP },
150 { NFS4ERR_OP_ILLEGAL, EOPNOTSUPP },
151 { NFS4ERR_DEADLOCK, EDEADLK },
152 { -1, EIO }
153 };
154
155 static int
156 nfs_cb_stat_to_errno(int stat)
157 {
158 int i;
159 for (i = 0; nfs_cb_errtbl[i].stat != -1; i++) {
160 if (nfs_cb_errtbl[i].stat == stat)
161 return nfs_cb_errtbl[i].errno;
162 }
163 /* If we cannot translate the error, the recovery routines should
164 * handle it.
165 * Note: remaining NFSv4 error codes have values > 10000, so should
166 * not conflict with native Linux error codes.
167 */
168 return stat;
169 }
170
171 static __be32 *xdr_encode_empty_array(__be32 *p)
172 {
173 *p++ = xdr_zero;
174 return p;
175 }
176
177 /*
178 * Encode/decode NFSv4 CB basic data types
179 *
180 * Basic NFSv4 callback data types are defined in section 15 of RFC
181 * 3530: "Network File System (NFS) version 4 Protocol" and section
182 * 20 of RFC 5661: "Network File System (NFS) Version 4 Minor Version
183 * 1 Protocol"
184 */
185
186 /*
187 * nfs_cb_opnum4
188 *
189 * enum nfs_cb_opnum4 {
190 * OP_CB_GETATTR = 3,
191 * ...
192 * };
193 */
194 enum nfs_cb_opnum4 {
195 OP_CB_GETATTR = 3,
196 OP_CB_RECALL = 4,
197 OP_CB_LAYOUTRECALL = 5,
198 OP_CB_NOTIFY = 6,
199 OP_CB_PUSH_DELEG = 7,
200 OP_CB_RECALL_ANY = 8,
201 OP_CB_RECALLABLE_OBJ_AVAIL = 9,
202 OP_CB_RECALL_SLOT = 10,
203 OP_CB_SEQUENCE = 11,
204 OP_CB_WANTS_CANCELLED = 12,
205 OP_CB_NOTIFY_LOCK = 13,
206 OP_CB_NOTIFY_DEVICEID = 14,
207 OP_CB_ILLEGAL = 10044
208 };
209
210 static void encode_nfs_cb_opnum4(struct xdr_stream *xdr, enum nfs_cb_opnum4 op)
211 {
212 __be32 *p;
213
214 p = xdr_reserve_space(xdr, 4);
215 *p = cpu_to_be32(op);
216 }
217
218 /*
219 * nfs_fh4
220 *
221 * typedef opaque nfs_fh4<NFS4_FHSIZE>;
222 */
223 static void encode_nfs_fh4(struct xdr_stream *xdr, const struct knfsd_fh *fh)
224 {
225 u32 length = fh->fh_size;
226 __be32 *p;
227
228 BUG_ON(length > NFS4_FHSIZE);
229 p = xdr_reserve_space(xdr, 4 + length);
230 xdr_encode_opaque(p, &fh->fh_base, length);
231 }
232
233 /*
234 * stateid4
235 *
236 * struct stateid4 {
237 * uint32_t seqid;
238 * opaque other[12];
239 * };
240 */
241 static void encode_stateid4(struct xdr_stream *xdr, const stateid_t *sid)
242 {
243 __be32 *p;
244
245 p = xdr_reserve_space(xdr, NFS4_STATEID_SIZE);
246 *p++ = cpu_to_be32(sid->si_generation);
247 xdr_encode_opaque_fixed(p, &sid->si_opaque, NFS4_STATEID_OTHER_SIZE);
248 }
249
250 /*
251 * sessionid4
252 *
253 * typedef opaque sessionid4[NFS4_SESSIONID_SIZE];
254 */
255 static void encode_sessionid4(struct xdr_stream *xdr,
256 const struct nfsd4_session *session)
257 {
258 __be32 *p;
259
260 p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN);
261 xdr_encode_opaque_fixed(p, session->se_sessionid.data,
262 NFS4_MAX_SESSIONID_LEN);
263 }
264
265 /*
266 * CB_COMPOUND4args
267 *
268 * struct CB_COMPOUND4args {
269 * utf8str_cs tag;
270 * uint32_t minorversion;
271 * uint32_t callback_ident;
272 * nfs_cb_argop4 argarray<>;
273 * };
274 */
275 static void encode_cb_compound4args(struct xdr_stream *xdr,
276 struct nfs4_cb_compound_hdr *hdr)
277 {
278 __be32 * p;
279
280 p = xdr_reserve_space(xdr, 4 + 4 + 4 + 4);
281 p = xdr_encode_empty_array(p); /* empty tag */
282 *p++ = cpu_to_be32(hdr->minorversion);
283 *p++ = cpu_to_be32(hdr->ident);
284
285 hdr->nops_p = p;
286 *p = cpu_to_be32(hdr->nops); /* argarray element count */
287 }
288
289 /*
290 * Update argarray element count
291 */
292 static void encode_cb_nops(struct nfs4_cb_compound_hdr *hdr)
293 {
294 BUG_ON(hdr->nops > NFS4_MAX_BACK_CHANNEL_OPS);
295 *hdr->nops_p = cpu_to_be32(hdr->nops);
296 }
297
298 /*
299 * CB_RECALL4args
300 *
301 * struct CB_RECALL4args {
302 * stateid4 stateid;
303 * bool truncate;
304 * nfs_fh4 fh;
305 * };
306 */
307 static void encode_cb_recall4args(struct xdr_stream *xdr,
308 const struct nfs4_delegation *dp,
309 struct nfs4_cb_compound_hdr *hdr)
310 {
311 __be32 *p;
312
313 encode_nfs_cb_opnum4(xdr, OP_CB_RECALL);
314 encode_stateid4(xdr, &dp->dl_stateid);
315
316 p = xdr_reserve_space(xdr, 4);
317 *p++ = xdr_zero; /* truncate */
318
319 encode_nfs_fh4(xdr, &dp->dl_fh);
320
321 hdr->nops++;
322 }
323
324 /*
325 * CB_SEQUENCE4args
326 *
327 * struct CB_SEQUENCE4args {
328 * sessionid4 csa_sessionid;
329 * sequenceid4 csa_sequenceid;
330 * slotid4 csa_slotid;
331 * slotid4 csa_highest_slotid;
332 * bool csa_cachethis;
333 * referring_call_list4 csa_referring_call_lists<>;
334 * };
335 */
336 static void encode_cb_sequence4args(struct xdr_stream *xdr,
337 const struct nfsd4_callback *cb,
338 struct nfs4_cb_compound_hdr *hdr)
339 {
340 struct nfsd4_session *session = cb->cb_clp->cl_cb_session;
341 __be32 *p;
342
343 if (hdr->minorversion == 0)
344 return;
345
346 encode_nfs_cb_opnum4(xdr, OP_CB_SEQUENCE);
347 encode_sessionid4(xdr, session);
348
349 p = xdr_reserve_space(xdr, 4 + 4 + 4 + 4 + 4);
350 *p++ = cpu_to_be32(session->se_cb_seq_nr); /* csa_sequenceid */
351 *p++ = xdr_zero; /* csa_slotid */
352 *p++ = xdr_zero; /* csa_highest_slotid */
353 *p++ = xdr_zero; /* csa_cachethis */
354 xdr_encode_empty_array(p); /* csa_referring_call_lists */
355
356 hdr->nops++;
357 }
358
359 /*
360 * NFSv4.0 and NFSv4.1 XDR encode functions
361 *
362 * NFSv4.0 callback argument types are defined in section 15 of RFC
363 * 3530: "Network File System (NFS) version 4 Protocol" and section 20
364 * of RFC 5661: "Network File System (NFS) Version 4 Minor Version 1
365 * Protocol".
366 */
367
368 /*
369 * NB: Without this zero space reservation, callbacks over krb5p fail
370 */
371 static int nfs4_xdr_enc_cb_null(struct rpc_rqst *req, __be32 *p, void *__unused)
372 {
373 struct xdr_stream xdrs, *xdr = &xdrs;
374
375 xdr_init_encode(&xdrs, &req->rq_snd_buf, p);
376 xdr_reserve_space(xdr, 0);
377 return 0;
378 }
379
380 /*
381 * 20.2. Operation 4: CB_RECALL - Recall a Delegation
382 */
383 static int nfs4_xdr_enc_cb_recall(struct rpc_rqst *req, __be32 *p,
384 const struct nfsd4_callback *cb)
385 {
386 struct xdr_stream xdr;
387 const struct nfs4_delegation *args = cb->cb_op;
388 struct nfs4_cb_compound_hdr hdr = {
389 .ident = cb->cb_clp->cl_cb_ident,
390 .minorversion = cb->cb_minorversion,
391 };
392
393 xdr_init_encode(&xdr, &req->rq_snd_buf, p);
394 encode_cb_compound4args(&xdr, &hdr);
395 encode_cb_sequence4args(&xdr, cb, &hdr);
396 encode_cb_recall4args(&xdr, args, &hdr);
397 encode_cb_nops(&hdr);
398 return 0;
399 }
400
401
402 static int
403 decode_cb_compound_hdr(struct xdr_stream *xdr, struct nfs4_cb_compound_hdr *hdr){
404 __be32 *p;
405 u32 taglen;
406
407 READ_BUF(8);
408 READ32(hdr->status);
409 /* We've got no use for the tag; ignore it: */
410 READ32(taglen);
411 READ_BUF(taglen + 4);
412 p += XDR_QUADLEN(taglen);
413 READ32(hdr->nops);
414 return 0;
415 }
416
417 static int
418 decode_cb_op_hdr(struct xdr_stream *xdr, enum nfs_opnum4 expected)
419 {
420 __be32 *p;
421 u32 op;
422 int32_t nfserr;
423
424 READ_BUF(8);
425 READ32(op);
426 if (op != expected) {
427 dprintk("NFSD: decode_cb_op_hdr: Callback server returned "
428 " operation %d but we issued a request for %d\n",
429 op, expected);
430 return -EIO;
431 }
432 READ32(nfserr);
433 if (nfserr != NFS_OK)
434 return -nfs_cb_stat_to_errno(nfserr);
435 return 0;
436 }
437
438 /*
439 * Our current back channel implmentation supports a single backchannel
440 * with a single slot.
441 */
442 static int
443 decode_cb_sequence(struct xdr_stream *xdr, struct nfsd4_callback *cb,
444 struct rpc_rqst *rqstp)
445 {
446 struct nfsd4_session *ses = cb->cb_clp->cl_cb_session;
447 struct nfs4_sessionid id;
448 int status;
449 u32 dummy;
450 __be32 *p;
451
452 if (cb->cb_minorversion == 0)
453 return 0;
454
455 status = decode_cb_op_hdr(xdr, OP_CB_SEQUENCE);
456 if (status)
457 return status;
458
459 /*
460 * If the server returns different values for sessionID, slotID or
461 * sequence number, the server is looney tunes.
462 */
463 status = -ESERVERFAULT;
464
465 READ_BUF(NFS4_MAX_SESSIONID_LEN + 16);
466 memcpy(id.data, p, NFS4_MAX_SESSIONID_LEN);
467 p += XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN);
468 if (memcmp(id.data, ses->se_sessionid.data, NFS4_MAX_SESSIONID_LEN)) {
469 dprintk("%s Invalid session id\n", __func__);
470 goto out;
471 }
472 READ32(dummy);
473 if (dummy != ses->se_cb_seq_nr) {
474 dprintk("%s Invalid sequence number\n", __func__);
475 goto out;
476 }
477 READ32(dummy); /* slotid must be 0 */
478 if (dummy != 0) {
479 dprintk("%s Invalid slotid\n", __func__);
480 goto out;
481 }
482 /* FIXME: process highest slotid and target highest slotid */
483 status = 0;
484 out:
485 return status;
486 }
487
488
489 static int
490 nfs4_xdr_dec_cb_null(struct rpc_rqst *req, __be32 *p)
491 {
492 return 0;
493 }
494
495 static int
496 nfs4_xdr_dec_cb_recall(struct rpc_rqst *rqstp, __be32 *p,
497 struct nfsd4_callback *cb)
498 {
499 struct xdr_stream xdr;
500 struct nfs4_cb_compound_hdr hdr;
501 int status;
502
503 xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, p);
504 status = decode_cb_compound_hdr(&xdr, &hdr);
505 if (status)
506 goto out;
507 if (cb) {
508 status = decode_cb_sequence(&xdr, cb, rqstp);
509 if (status)
510 goto out;
511 }
512 status = decode_cb_op_hdr(&xdr, OP_CB_RECALL);
513 out:
514 return status;
515 }
516
517 /*
518 * RPC procedure tables
519 */
520 #define PROC(proc, call, argtype, restype) \
521 [NFSPROC4_CLNT_##proc] = { \
522 .p_proc = NFSPROC4_CB_##call, \
523 .p_encode = (kxdrproc_t) nfs4_xdr_##argtype, \
524 .p_decode = (kxdrproc_t) nfs4_xdr_##restype, \
525 .p_arglen = NFS4_##argtype##_sz, \
526 .p_replen = NFS4_##restype##_sz, \
527 .p_statidx = NFSPROC4_CB_##call, \
528 .p_name = #proc, \
529 }
530
531 static struct rpc_procinfo nfs4_cb_procedures[] = {
532 PROC(CB_NULL, NULL, enc_cb_null, dec_cb_null),
533 PROC(CB_RECALL, COMPOUND, enc_cb_recall, dec_cb_recall),
534 };
535
536 static struct rpc_version nfs_cb_version4 = {
537 /*
538 * Note on the callback rpc program version number: despite language in rfc
539 * 5661 section 18.36.3 requiring servers to use 4 in this field, the
540 * official xdr descriptions for both 4.0 and 4.1 specify version 1, and
541 * in practice that appears to be what implementations use. The section
542 * 18.36.3 language is expected to be fixed in an erratum.
543 */
544 .number = 1,
545 .nrprocs = ARRAY_SIZE(nfs4_cb_procedures),
546 .procs = nfs4_cb_procedures
547 };
548
549 static struct rpc_version * nfs_cb_version[] = {
550 &nfs_cb_version4,
551 };
552
553 static struct rpc_program cb_program;
554
555 static struct rpc_stat cb_stats = {
556 .program = &cb_program
557 };
558
559 #define NFS4_CALLBACK 0x40000000
560 static struct rpc_program cb_program = {
561 .name = "nfs4_cb",
562 .number = NFS4_CALLBACK,
563 .nrvers = ARRAY_SIZE(nfs_cb_version),
564 .version = nfs_cb_version,
565 .stats = &cb_stats,
566 .pipe_dir_name = "/nfsd4_cb",
567 };
568
569 static int max_cb_time(void)
570 {
571 return max(nfsd4_lease/10, (time_t)1) * HZ;
572 }
573
574 /* Reference counting, callback cleanup, etc., all look racy as heck.
575 * And why is cl_cb_set an atomic? */
576
577 int setup_callback_client(struct nfs4_client *clp, struct nfs4_cb_conn *conn)
578 {
579 struct rpc_timeout timeparms = {
580 .to_initval = max_cb_time(),
581 .to_retries = 0,
582 };
583 struct rpc_create_args args = {
584 .net = &init_net,
585 .address = (struct sockaddr *) &conn->cb_addr,
586 .addrsize = conn->cb_addrlen,
587 .timeout = &timeparms,
588 .program = &cb_program,
589 .version = 0,
590 .authflavor = clp->cl_flavor,
591 .flags = (RPC_CLNT_CREATE_NOPING | RPC_CLNT_CREATE_QUIET),
592 };
593 struct rpc_clnt *client;
594
595 if (clp->cl_minorversion == 0) {
596 if (!clp->cl_principal && (clp->cl_flavor >= RPC_AUTH_GSS_KRB5))
597 return -EINVAL;
598 args.client_name = clp->cl_principal;
599 args.prognumber = conn->cb_prog,
600 args.protocol = XPRT_TRANSPORT_TCP;
601 clp->cl_cb_ident = conn->cb_ident;
602 } else {
603 args.bc_xprt = conn->cb_xprt;
604 args.prognumber = clp->cl_cb_session->se_cb_prog;
605 args.protocol = XPRT_TRANSPORT_BC_TCP;
606 }
607 /* Create RPC client */
608 client = rpc_create(&args);
609 if (IS_ERR(client)) {
610 dprintk("NFSD: couldn't create callback client: %ld\n",
611 PTR_ERR(client));
612 return PTR_ERR(client);
613 }
614 clp->cl_cb_client = client;
615 return 0;
616
617 }
618
619 static void warn_no_callback_path(struct nfs4_client *clp, int reason)
620 {
621 dprintk("NFSD: warning: no callback path to client %.*s: error %d\n",
622 (int)clp->cl_name.len, clp->cl_name.data, reason);
623 }
624
625 static void nfsd4_cb_probe_done(struct rpc_task *task, void *calldata)
626 {
627 struct nfs4_client *clp = container_of(calldata, struct nfs4_client, cl_cb_null);
628
629 if (task->tk_status)
630 warn_no_callback_path(clp, task->tk_status);
631 else
632 atomic_set(&clp->cl_cb_set, 1);
633 }
634
635 static const struct rpc_call_ops nfsd4_cb_probe_ops = {
636 /* XXX: release method to ensure we set the cb channel down if
637 * necessary on early failure? */
638 .rpc_call_done = nfsd4_cb_probe_done,
639 };
640
641 static struct rpc_cred *callback_cred;
642
643 int set_callback_cred(void)
644 {
645 if (callback_cred)
646 return 0;
647 callback_cred = rpc_lookup_machine_cred();
648 if (!callback_cred)
649 return -ENOMEM;
650 return 0;
651 }
652
653 static struct workqueue_struct *callback_wq;
654
655 static void do_probe_callback(struct nfs4_client *clp)
656 {
657 struct nfsd4_callback *cb = &clp->cl_cb_null;
658
659 cb->cb_op = NULL;
660 cb->cb_clp = clp;
661
662 cb->cb_msg.rpc_proc = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_NULL];
663 cb->cb_msg.rpc_argp = NULL;
664 cb->cb_msg.rpc_resp = NULL;
665 cb->cb_msg.rpc_cred = callback_cred;
666
667 cb->cb_ops = &nfsd4_cb_probe_ops;
668
669 queue_work(callback_wq, &cb->cb_work);
670 }
671
672 /*
673 * Poke the callback thread to process any updates to the callback
674 * parameters, and send a null probe.
675 */
676 void nfsd4_probe_callback(struct nfs4_client *clp)
677 {
678 set_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_cb_flags);
679 do_probe_callback(clp);
680 }
681
682 void nfsd4_change_callback(struct nfs4_client *clp, struct nfs4_cb_conn *conn)
683 {
684 BUG_ON(atomic_read(&clp->cl_cb_set));
685
686 spin_lock(&clp->cl_lock);
687 memcpy(&clp->cl_cb_conn, conn, sizeof(struct nfs4_cb_conn));
688 spin_unlock(&clp->cl_lock);
689 }
690
691 /*
692 * There's currently a single callback channel slot.
693 * If the slot is available, then mark it busy. Otherwise, set the
694 * thread for sleeping on the callback RPC wait queue.
695 */
696 static int nfsd41_cb_setup_sequence(struct nfs4_client *clp,
697 struct rpc_task *task)
698 {
699 u32 *ptr = (u32 *)clp->cl_cb_session->se_sessionid.data;
700 int status = 0;
701
702 dprintk("%s: %u:%u:%u:%u\n", __func__,
703 ptr[0], ptr[1], ptr[2], ptr[3]);
704
705 if (test_and_set_bit(0, &clp->cl_cb_slot_busy) != 0) {
706 rpc_sleep_on(&clp->cl_cb_waitq, task, NULL);
707 dprintk("%s slot is busy\n", __func__);
708 status = -EAGAIN;
709 goto out;
710 }
711 out:
712 dprintk("%s status=%d\n", __func__, status);
713 return status;
714 }
715
716 /*
717 * TODO: cb_sequence should support referring call lists, cachethis, multiple
718 * slots, and mark callback channel down on communication errors.
719 */
720 static void nfsd4_cb_prepare(struct rpc_task *task, void *calldata)
721 {
722 struct nfsd4_callback *cb = calldata;
723 struct nfs4_delegation *dp = container_of(cb, struct nfs4_delegation, dl_recall);
724 struct nfs4_client *clp = dp->dl_client;
725 u32 minorversion = clp->cl_minorversion;
726 int status = 0;
727
728 cb->cb_minorversion = minorversion;
729 if (minorversion) {
730 status = nfsd41_cb_setup_sequence(clp, task);
731 if (status) {
732 if (status != -EAGAIN) {
733 /* terminate rpc task */
734 task->tk_status = status;
735 task->tk_action = NULL;
736 }
737 return;
738 }
739 }
740 rpc_call_start(task);
741 }
742
743 static void nfsd4_cb_done(struct rpc_task *task, void *calldata)
744 {
745 struct nfsd4_callback *cb = calldata;
746 struct nfs4_delegation *dp = container_of(cb, struct nfs4_delegation, dl_recall);
747 struct nfs4_client *clp = dp->dl_client;
748
749 dprintk("%s: minorversion=%d\n", __func__,
750 clp->cl_minorversion);
751
752 if (clp->cl_minorversion) {
753 /* No need for lock, access serialized in nfsd4_cb_prepare */
754 ++clp->cl_cb_session->se_cb_seq_nr;
755 clear_bit(0, &clp->cl_cb_slot_busy);
756 rpc_wake_up_next(&clp->cl_cb_waitq);
757 dprintk("%s: freed slot, new seqid=%d\n", __func__,
758 clp->cl_cb_session->se_cb_seq_nr);
759
760 /* We're done looking into the sequence information */
761 task->tk_msg.rpc_resp = NULL;
762 }
763 }
764
765
766 static void nfsd4_cb_recall_done(struct rpc_task *task, void *calldata)
767 {
768 struct nfsd4_callback *cb = calldata;
769 struct nfs4_delegation *dp = container_of(cb, struct nfs4_delegation, dl_recall);
770 struct nfs4_client *clp = dp->dl_client;
771 struct rpc_clnt *current_rpc_client = clp->cl_cb_client;
772
773 nfsd4_cb_done(task, calldata);
774
775 if (current_rpc_client == NULL) {
776 /* We're shutting down; give up. */
777 /* XXX: err, or is it ok just to fall through
778 * and rpc_restart_call? */
779 return;
780 }
781
782 switch (task->tk_status) {
783 case 0:
784 return;
785 case -EBADHANDLE:
786 case -NFS4ERR_BAD_STATEID:
787 /* Race: client probably got cb_recall
788 * before open reply granting delegation */
789 break;
790 default:
791 /* Network partition? */
792 atomic_set(&clp->cl_cb_set, 0);
793 warn_no_callback_path(clp, task->tk_status);
794 if (current_rpc_client != task->tk_client) {
795 /* queue a callback on the new connection: */
796 atomic_inc(&dp->dl_count);
797 nfsd4_cb_recall(dp);
798 return;
799 }
800 }
801 if (dp->dl_retries--) {
802 rpc_delay(task, 2*HZ);
803 task->tk_status = 0;
804 rpc_restart_call_prepare(task);
805 return;
806 } else {
807 atomic_set(&clp->cl_cb_set, 0);
808 warn_no_callback_path(clp, task->tk_status);
809 }
810 }
811
812 static void nfsd4_cb_recall_release(void *calldata)
813 {
814 struct nfsd4_callback *cb = calldata;
815 struct nfs4_delegation *dp = container_of(cb, struct nfs4_delegation, dl_recall);
816
817 nfs4_put_delegation(dp);
818 }
819
820 static const struct rpc_call_ops nfsd4_cb_recall_ops = {
821 .rpc_call_prepare = nfsd4_cb_prepare,
822 .rpc_call_done = nfsd4_cb_recall_done,
823 .rpc_release = nfsd4_cb_recall_release,
824 };
825
826 int nfsd4_create_callback_queue(void)
827 {
828 callback_wq = create_singlethread_workqueue("nfsd4_callbacks");
829 if (!callback_wq)
830 return -ENOMEM;
831 return 0;
832 }
833
834 void nfsd4_destroy_callback_queue(void)
835 {
836 destroy_workqueue(callback_wq);
837 }
838
839 /* must be called under the state lock */
840 void nfsd4_shutdown_callback(struct nfs4_client *clp)
841 {
842 set_bit(NFSD4_CLIENT_KILL, &clp->cl_cb_flags);
843 /*
844 * Note this won't actually result in a null callback;
845 * instead, nfsd4_do_callback_rpc() will detect the killed
846 * client, destroy the rpc client, and stop:
847 */
848 do_probe_callback(clp);
849 flush_workqueue(callback_wq);
850 }
851
852 void nfsd4_release_cb(struct nfsd4_callback *cb)
853 {
854 if (cb->cb_ops->rpc_release)
855 cb->cb_ops->rpc_release(cb);
856 }
857
858 void nfsd4_process_cb_update(struct nfsd4_callback *cb)
859 {
860 struct nfs4_cb_conn conn;
861 struct nfs4_client *clp = cb->cb_clp;
862 int err;
863
864 /*
865 * This is either an update, or the client dying; in either case,
866 * kill the old client:
867 */
868 if (clp->cl_cb_client) {
869 rpc_shutdown_client(clp->cl_cb_client);
870 clp->cl_cb_client = NULL;
871 }
872 if (test_bit(NFSD4_CLIENT_KILL, &clp->cl_cb_flags))
873 return;
874 spin_lock(&clp->cl_lock);
875 /*
876 * Only serialized callback code is allowed to clear these
877 * flags; main nfsd code can only set them:
878 */
879 BUG_ON(!clp->cl_cb_flags);
880 clear_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_cb_flags);
881 memcpy(&conn, &cb->cb_clp->cl_cb_conn, sizeof(struct nfs4_cb_conn));
882 spin_unlock(&clp->cl_lock);
883
884 err = setup_callback_client(clp, &conn);
885 if (err)
886 warn_no_callback_path(clp, err);
887 }
888
889 void nfsd4_do_callback_rpc(struct work_struct *w)
890 {
891 struct nfsd4_callback *cb = container_of(w, struct nfsd4_callback, cb_work);
892 struct nfs4_client *clp = cb->cb_clp;
893 struct rpc_clnt *clnt;
894
895 if (clp->cl_cb_flags)
896 nfsd4_process_cb_update(cb);
897
898 clnt = clp->cl_cb_client;
899 if (!clnt) {
900 /* Callback channel broken, or client killed; give up: */
901 nfsd4_release_cb(cb);
902 return;
903 }
904 rpc_call_async(clnt, &cb->cb_msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN,
905 cb->cb_ops, cb);
906 }
907
908 void nfsd4_cb_recall(struct nfs4_delegation *dp)
909 {
910 struct nfsd4_callback *cb = &dp->dl_recall;
911
912 dp->dl_retries = 1;
913 cb->cb_op = dp;
914 cb->cb_clp = dp->dl_client;
915 cb->cb_msg.rpc_proc = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_RECALL];
916 cb->cb_msg.rpc_argp = cb;
917 cb->cb_msg.rpc_resp = cb;
918 cb->cb_msg.rpc_cred = callback_cred;
919
920 cb->cb_ops = &nfsd4_cb_recall_ops;
921 dp->dl_retries = 1;
922
923 queue_work(callback_wq, &dp->dl_recall.cb_work);
924 }
Linux 2.6 ibm-acpi/thinkpad-acpi driver git tree