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nfsd4: initialize cb_per_client
[deliverable/linux.git] / fs / nfsd / nfs4callback.c
1 /*
2 * Copyright (c) 2001 The Regents of the University of Michigan.
3 * All rights reserved.
4 *
5 * Kendrick Smith <kmsmith@umich.edu>
6 * Andy Adamson <andros@umich.edu>
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 *
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 * 3. Neither the name of the University nor the names of its
18 * contributors may be used to endorse or promote products derived
19 * from this software without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
22 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
23 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
24 * DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
26 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
27 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
28 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
29 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
30 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
31 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32 */
33
34 #include <linux/sunrpc/clnt.h>
35 #include <linux/sunrpc/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 enum nfs_cb_opnum4 {
54 OP_CB_RECALL = 4,
55 OP_CB_SEQUENCE = 11,
56 };
57
58 #define NFS4_MAXTAGLEN 20
59
60 #define NFS4_enc_cb_null_sz 0
61 #define NFS4_dec_cb_null_sz 0
62 #define cb_compound_enc_hdr_sz 4
63 #define cb_compound_dec_hdr_sz (3 + (NFS4_MAXTAGLEN >> 2))
64 #define sessionid_sz (NFS4_MAX_SESSIONID_LEN >> 2)
65 #define cb_sequence_enc_sz (sessionid_sz + 4 + \
66 1 /* no referring calls list yet */)
67 #define cb_sequence_dec_sz (op_dec_sz + sessionid_sz + 4)
68
69 #define op_enc_sz 1
70 #define op_dec_sz 2
71 #define enc_nfs4_fh_sz (1 + (NFS4_FHSIZE >> 2))
72 #define enc_stateid_sz (NFS4_STATEID_SIZE >> 2)
73 #define NFS4_enc_cb_recall_sz (cb_compound_enc_hdr_sz + \
74 cb_sequence_enc_sz + \
75 1 + enc_stateid_sz + \
76 enc_nfs4_fh_sz)
77
78 #define NFS4_dec_cb_recall_sz (cb_compound_dec_hdr_sz + \
79 cb_sequence_dec_sz + \
80 op_dec_sz)
81
82 /*
83 * Generic encode routines from fs/nfs/nfs4xdr.c
84 */
85 static inline __be32 *
86 xdr_writemem(__be32 *p, const void *ptr, int nbytes)
87 {
88 int tmp = XDR_QUADLEN(nbytes);
89 if (!tmp)
90 return p;
91 p[tmp-1] = 0;
92 memcpy(p, ptr, nbytes);
93 return p + tmp;
94 }
95
96 #define WRITE32(n) *p++ = htonl(n)
97 #define WRITEMEM(ptr,nbytes) do { \
98 p = xdr_writemem(p, ptr, nbytes); \
99 } while (0)
100 #define RESERVE_SPACE(nbytes) do { \
101 p = xdr_reserve_space(xdr, nbytes); \
102 if (!p) dprintk("NFSD: RESERVE_SPACE(%d) failed in function %s\n", (int) (nbytes), __func__); \
103 BUG_ON(!p); \
104 } while (0)
105
106 /*
107 * Generic decode routines from fs/nfs/nfs4xdr.c
108 */
109 #define DECODE_TAIL \
110 status = 0; \
111 out: \
112 return status; \
113 xdr_error: \
114 dprintk("NFSD: xdr error! (%s:%d)\n", __FILE__, __LINE__); \
115 status = -EIO; \
116 goto out
117
118 #define READ32(x) (x) = ntohl(*p++)
119 #define READ64(x) do { \
120 (x) = (u64)ntohl(*p++) << 32; \
121 (x) |= ntohl(*p++); \
122 } while (0)
123 #define READTIME(x) do { \
124 p++; \
125 (x.tv_sec) = ntohl(*p++); \
126 (x.tv_nsec) = ntohl(*p++); \
127 } while (0)
128 #define READ_BUF(nbytes) do { \
129 p = xdr_inline_decode(xdr, nbytes); \
130 if (!p) { \
131 dprintk("NFSD: %s: reply buffer overflowed in line %d.\n", \
132 __func__, __LINE__); \
133 return -EIO; \
134 } \
135 } while (0)
136
137 struct nfs4_cb_compound_hdr {
138 /* args */
139 u32 ident; /* minorversion 0 only */
140 u32 nops;
141 __be32 *nops_p;
142 u32 minorversion;
143 /* res */
144 int status;
145 };
146
147 static struct {
148 int stat;
149 int errno;
150 } nfs_cb_errtbl[] = {
151 { NFS4_OK, 0 },
152 { NFS4ERR_PERM, EPERM },
153 { NFS4ERR_NOENT, ENOENT },
154 { NFS4ERR_IO, EIO },
155 { NFS4ERR_NXIO, ENXIO },
156 { NFS4ERR_ACCESS, EACCES },
157 { NFS4ERR_EXIST, EEXIST },
158 { NFS4ERR_XDEV, EXDEV },
159 { NFS4ERR_NOTDIR, ENOTDIR },
160 { NFS4ERR_ISDIR, EISDIR },
161 { NFS4ERR_INVAL, EINVAL },
162 { NFS4ERR_FBIG, EFBIG },
163 { NFS4ERR_NOSPC, ENOSPC },
164 { NFS4ERR_ROFS, EROFS },
165 { NFS4ERR_MLINK, EMLINK },
166 { NFS4ERR_NAMETOOLONG, ENAMETOOLONG },
167 { NFS4ERR_NOTEMPTY, ENOTEMPTY },
168 { NFS4ERR_DQUOT, EDQUOT },
169 { NFS4ERR_STALE, ESTALE },
170 { NFS4ERR_BADHANDLE, EBADHANDLE },
171 { NFS4ERR_BAD_COOKIE, EBADCOOKIE },
172 { NFS4ERR_NOTSUPP, ENOTSUPP },
173 { NFS4ERR_TOOSMALL, ETOOSMALL },
174 { NFS4ERR_SERVERFAULT, ESERVERFAULT },
175 { NFS4ERR_BADTYPE, EBADTYPE },
176 { NFS4ERR_LOCKED, EAGAIN },
177 { NFS4ERR_RESOURCE, EREMOTEIO },
178 { NFS4ERR_SYMLINK, ELOOP },
179 { NFS4ERR_OP_ILLEGAL, EOPNOTSUPP },
180 { NFS4ERR_DEADLOCK, EDEADLK },
181 { -1, EIO }
182 };
183
184 static int
185 nfs_cb_stat_to_errno(int stat)
186 {
187 int i;
188 for (i = 0; nfs_cb_errtbl[i].stat != -1; i++) {
189 if (nfs_cb_errtbl[i].stat == stat)
190 return nfs_cb_errtbl[i].errno;
191 }
192 /* If we cannot translate the error, the recovery routines should
193 * handle it.
194 * Note: remaining NFSv4 error codes have values > 10000, so should
195 * not conflict with native Linux error codes.
196 */
197 return stat;
198 }
199
200 /*
201 * XDR encode
202 */
203
204 static void
205 encode_stateid(struct xdr_stream *xdr, stateid_t *sid)
206 {
207 __be32 *p;
208
209 RESERVE_SPACE(sizeof(stateid_t));
210 WRITE32(sid->si_generation);
211 WRITEMEM(&sid->si_opaque, sizeof(stateid_opaque_t));
212 }
213
214 static void
215 encode_cb_compound_hdr(struct xdr_stream *xdr, struct nfs4_cb_compound_hdr *hdr)
216 {
217 __be32 * p;
218
219 RESERVE_SPACE(16);
220 WRITE32(0); /* tag length is always 0 */
221 WRITE32(hdr->minorversion);
222 WRITE32(hdr->ident);
223 hdr->nops_p = p;
224 WRITE32(hdr->nops);
225 }
226
227 static void encode_cb_nops(struct nfs4_cb_compound_hdr *hdr)
228 {
229 *hdr->nops_p = htonl(hdr->nops);
230 }
231
232 static void
233 encode_cb_recall(struct xdr_stream *xdr, struct nfs4_delegation *dp,
234 struct nfs4_cb_compound_hdr *hdr)
235 {
236 __be32 *p;
237 int len = dp->dl_fh.fh_size;
238
239 RESERVE_SPACE(4);
240 WRITE32(OP_CB_RECALL);
241 encode_stateid(xdr, &dp->dl_stateid);
242 RESERVE_SPACE(8 + (XDR_QUADLEN(len) << 2));
243 WRITE32(0); /* truncate optimization not implemented */
244 WRITE32(len);
245 WRITEMEM(&dp->dl_fh.fh_base, len);
246 hdr->nops++;
247 }
248
249 static void
250 encode_cb_sequence(struct xdr_stream *xdr, struct nfsd4_callback *cb,
251 struct nfs4_cb_compound_hdr *hdr)
252 {
253 __be32 *p;
254 struct nfsd4_session *ses = cb->cb_clp->cl_cb_session;
255
256 if (hdr->minorversion == 0)
257 return;
258
259 RESERVE_SPACE(1 + NFS4_MAX_SESSIONID_LEN + 20);
260
261 WRITE32(OP_CB_SEQUENCE);
262 WRITEMEM(ses->se_sessionid.data, NFS4_MAX_SESSIONID_LEN);
263 WRITE32(ses->se_cb_seq_nr);
264 WRITE32(0); /* slotid, always 0 */
265 WRITE32(0); /* highest slotid always 0 */
266 WRITE32(0); /* cachethis always 0 */
267 WRITE32(0); /* FIXME: support referring_call_lists */
268 hdr->nops++;
269 }
270
271 static int
272 nfs4_xdr_enc_cb_null(struct rpc_rqst *req, __be32 *p)
273 {
274 struct xdr_stream xdrs, *xdr = &xdrs;
275
276 xdr_init_encode(&xdrs, &req->rq_snd_buf, p);
277 RESERVE_SPACE(0);
278 return 0;
279 }
280
281 static int
282 nfs4_xdr_enc_cb_recall(struct rpc_rqst *req, __be32 *p,
283 struct nfsd4_callback *cb)
284 {
285 struct xdr_stream xdr;
286 struct nfs4_delegation *args = cb->cb_op;
287 struct nfs4_cb_compound_hdr hdr = {
288 .ident = cb->cb_clp->cl_cb_ident,
289 .minorversion = cb->cb_minorversion,
290 };
291
292 xdr_init_encode(&xdr, &req->rq_snd_buf, p);
293 encode_cb_compound_hdr(&xdr, &hdr);
294 encode_cb_sequence(&xdr, cb, &hdr);
295 encode_cb_recall(&xdr, args, &hdr);
296 encode_cb_nops(&hdr);
297 return 0;
298 }
299
300
301 static int
302 decode_cb_compound_hdr(struct xdr_stream *xdr, struct nfs4_cb_compound_hdr *hdr){
303 __be32 *p;
304 u32 taglen;
305
306 READ_BUF(8);
307 READ32(hdr->status);
308 /* We've got no use for the tag; ignore it: */
309 READ32(taglen);
310 READ_BUF(taglen + 4);
311 p += XDR_QUADLEN(taglen);
312 READ32(hdr->nops);
313 return 0;
314 }
315
316 static int
317 decode_cb_op_hdr(struct xdr_stream *xdr, enum nfs_opnum4 expected)
318 {
319 __be32 *p;
320 u32 op;
321 int32_t nfserr;
322
323 READ_BUF(8);
324 READ32(op);
325 if (op != expected) {
326 dprintk("NFSD: decode_cb_op_hdr: Callback server returned "
327 " operation %d but we issued a request for %d\n",
328 op, expected);
329 return -EIO;
330 }
331 READ32(nfserr);
332 if (nfserr != NFS_OK)
333 return -nfs_cb_stat_to_errno(nfserr);
334 return 0;
335 }
336
337 /*
338 * Our current back channel implmentation supports a single backchannel
339 * with a single slot.
340 */
341 static int
342 decode_cb_sequence(struct xdr_stream *xdr, struct nfsd4_callback *cb,
343 struct rpc_rqst *rqstp)
344 {
345 struct nfsd4_session *ses = cb->cb_clp->cl_cb_session;
346 struct nfs4_sessionid id;
347 int status;
348 u32 dummy;
349 __be32 *p;
350
351 if (cb->cb_minorversion == 0)
352 return 0;
353
354 status = decode_cb_op_hdr(xdr, OP_CB_SEQUENCE);
355 if (status)
356 return status;
357
358 /*
359 * If the server returns different values for sessionID, slotID or
360 * sequence number, the server is looney tunes.
361 */
362 status = -ESERVERFAULT;
363
364 READ_BUF(NFS4_MAX_SESSIONID_LEN + 16);
365 memcpy(id.data, p, NFS4_MAX_SESSIONID_LEN);
366 p += XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN);
367 if (memcmp(id.data, ses->se_sessionid.data, NFS4_MAX_SESSIONID_LEN)) {
368 dprintk("%s Invalid session id\n", __func__);
369 goto out;
370 }
371 READ32(dummy);
372 if (dummy != ses->se_cb_seq_nr) {
373 dprintk("%s Invalid sequence number\n", __func__);
374 goto out;
375 }
376 READ32(dummy); /* slotid must be 0 */
377 if (dummy != 0) {
378 dprintk("%s Invalid slotid\n", __func__);
379 goto out;
380 }
381 /* FIXME: process highest slotid and target highest slotid */
382 status = 0;
383 out:
384 return status;
385 }
386
387
388 static int
389 nfs4_xdr_dec_cb_null(struct rpc_rqst *req, __be32 *p)
390 {
391 return 0;
392 }
393
394 static int
395 nfs4_xdr_dec_cb_recall(struct rpc_rqst *rqstp, __be32 *p,
396 struct nfsd4_callback *cb)
397 {
398 struct xdr_stream xdr;
399 struct nfs4_cb_compound_hdr hdr;
400 int status;
401
402 xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, p);
403 status = decode_cb_compound_hdr(&xdr, &hdr);
404 if (status)
405 goto out;
406 if (cb) {
407 status = decode_cb_sequence(&xdr, cb, rqstp);
408 if (status)
409 goto out;
410 }
411 status = decode_cb_op_hdr(&xdr, OP_CB_RECALL);
412 out:
413 return status;
414 }
415
416 /*
417 * RPC procedure tables
418 */
419 #define PROC(proc, call, argtype, restype) \
420 [NFSPROC4_CLNT_##proc] = { \
421 .p_proc = NFSPROC4_CB_##call, \
422 .p_encode = (kxdrproc_t) nfs4_xdr_##argtype, \
423 .p_decode = (kxdrproc_t) nfs4_xdr_##restype, \
424 .p_arglen = NFS4_##argtype##_sz, \
425 .p_replen = NFS4_##restype##_sz, \
426 .p_statidx = NFSPROC4_CB_##call, \
427 .p_name = #proc, \
428 }
429
430 static struct rpc_procinfo nfs4_cb_procedures[] = {
431 PROC(CB_NULL, NULL, enc_cb_null, dec_cb_null),
432 PROC(CB_RECALL, COMPOUND, enc_cb_recall, dec_cb_recall),
433 };
434
435 static struct rpc_version nfs_cb_version4 = {
436 /*
437 * Note on the callback rpc program version number: despite language in rfc
438 * 5661 section 18.36.3 requiring servers to use 4 in this field, the
439 * official xdr descriptions for both 4.0 and 4.1 specify version 1, and
440 * in practice that appears to be what implementations use. The section
441 * 18.36.3 language is expected to be fixed in an erratum.
442 */
443 .number = 1,
444 .nrprocs = ARRAY_SIZE(nfs4_cb_procedures),
445 .procs = nfs4_cb_procedures
446 };
447
448 static struct rpc_version * nfs_cb_version[] = {
449 &nfs_cb_version4,
450 };
451
452 static struct rpc_program cb_program;
453
454 static struct rpc_stat cb_stats = {
455 .program = &cb_program
456 };
457
458 #define NFS4_CALLBACK 0x40000000
459 static struct rpc_program cb_program = {
460 .name = "nfs4_cb",
461 .number = NFS4_CALLBACK,
462 .nrvers = ARRAY_SIZE(nfs_cb_version),
463 .version = nfs_cb_version,
464 .stats = &cb_stats,
465 .pipe_dir_name = "/nfsd4_cb",
466 };
467
468 static int max_cb_time(void)
469 {
470 return max(nfsd4_lease/10, (time_t)1) * HZ;
471 }
472
473
474 static int setup_callback_client(struct nfs4_client *clp, struct nfs4_cb_conn *conn, struct nfsd4_session *ses)
475 {
476 struct rpc_timeout timeparms = {
477 .to_initval = max_cb_time(),
478 .to_retries = 0,
479 };
480 struct rpc_create_args args = {
481 .net = &init_net,
482 .address = (struct sockaddr *) &conn->cb_addr,
483 .addrsize = conn->cb_addrlen,
484 .saddress = (struct sockaddr *) &conn->cb_saddr,
485 .timeout = &timeparms,
486 .program = &cb_program,
487 .version = 0,
488 .authflavor = clp->cl_flavor,
489 .flags = (RPC_CLNT_CREATE_NOPING | RPC_CLNT_CREATE_QUIET),
490 };
491 struct rpc_clnt *client;
492
493 if (clp->cl_minorversion == 0) {
494 if (!clp->cl_principal && (clp->cl_flavor >= RPC_AUTH_GSS_KRB5))
495 return -EINVAL;
496 args.client_name = clp->cl_principal;
497 args.prognumber = conn->cb_prog,
498 args.protocol = XPRT_TRANSPORT_TCP;
499 clp->cl_cb_ident = conn->cb_ident;
500 } else {
501 if (!conn->cb_xprt)
502 return -EINVAL;
503 clp->cl_cb_conn.cb_xprt = conn->cb_xprt;
504 clp->cl_cb_session = ses;
505 args.bc_xprt = conn->cb_xprt;
506 args.prognumber = clp->cl_cb_session->se_cb_prog;
507 args.protocol = XPRT_TRANSPORT_BC_TCP;
508 }
509 /* Create RPC client */
510 client = rpc_create(&args);
511 if (IS_ERR(client)) {
512 dprintk("NFSD: couldn't create callback client: %ld\n",
513 PTR_ERR(client));
514 return PTR_ERR(client);
515 }
516 clp->cl_cb_client = client;
517 return 0;
518
519 }
520
521 static void warn_no_callback_path(struct nfs4_client *clp, int reason)
522 {
523 dprintk("NFSD: warning: no callback path to client %.*s: error %d\n",
524 (int)clp->cl_name.len, clp->cl_name.data, reason);
525 }
526
527 static void nfsd4_mark_cb_down(struct nfs4_client *clp, int reason)
528 {
529 clp->cl_cb_state = NFSD4_CB_DOWN;
530 warn_no_callback_path(clp, reason);
531 }
532
533 static void nfsd4_cb_probe_done(struct rpc_task *task, void *calldata)
534 {
535 struct nfs4_client *clp = container_of(calldata, struct nfs4_client, cl_cb_null);
536
537 if (task->tk_status)
538 nfsd4_mark_cb_down(clp, task->tk_status);
539 else
540 clp->cl_cb_state = NFSD4_CB_UP;
541 }
542
543 static const struct rpc_call_ops nfsd4_cb_probe_ops = {
544 /* XXX: release method to ensure we set the cb channel down if
545 * necessary on early failure? */
546 .rpc_call_done = nfsd4_cb_probe_done,
547 };
548
549 static struct rpc_cred *callback_cred;
550
551 int set_callback_cred(void)
552 {
553 if (callback_cred)
554 return 0;
555 callback_cred = rpc_lookup_machine_cred();
556 if (!callback_cred)
557 return -ENOMEM;
558 return 0;
559 }
560
561 static struct workqueue_struct *callback_wq;
562
563 static void run_nfsd4_cb(struct nfsd4_callback *cb)
564 {
565 queue_work(callback_wq, &cb->cb_work);
566 }
567
568 static void do_probe_callback(struct nfs4_client *clp)
569 {
570 struct nfsd4_callback *cb = &clp->cl_cb_null;
571
572 cb->cb_op = NULL;
573 cb->cb_clp = clp;
574
575 cb->cb_msg.rpc_proc = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_NULL];
576 cb->cb_msg.rpc_argp = NULL;
577 cb->cb_msg.rpc_resp = NULL;
578 cb->cb_msg.rpc_cred = callback_cred;
579
580 cb->cb_ops = &nfsd4_cb_probe_ops;
581
582 run_nfsd4_cb(cb);
583 }
584
585 /*
586 * Poke the callback thread to process any updates to the callback
587 * parameters, and send a null probe.
588 */
589 void nfsd4_probe_callback(struct nfs4_client *clp)
590 {
591 /* XXX: atomicity? Also, should we be using cl_cb_flags? */
592 clp->cl_cb_state = NFSD4_CB_UNKNOWN;
593 set_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_cb_flags);
594 do_probe_callback(clp);
595 }
596
597 void nfsd4_probe_callback_sync(struct nfs4_client *clp)
598 {
599 nfsd4_probe_callback(clp);
600 flush_workqueue(callback_wq);
601 }
602
603 void nfsd4_change_callback(struct nfs4_client *clp, struct nfs4_cb_conn *conn)
604 {
605 clp->cl_cb_state = NFSD4_CB_UNKNOWN;
606 spin_lock(&clp->cl_lock);
607 memcpy(&clp->cl_cb_conn, conn, sizeof(struct nfs4_cb_conn));
608 spin_unlock(&clp->cl_lock);
609 }
610
611 /*
612 * There's currently a single callback channel slot.
613 * If the slot is available, then mark it busy. Otherwise, set the
614 * thread for sleeping on the callback RPC wait queue.
615 */
616 static bool nfsd41_cb_get_slot(struct nfs4_client *clp, struct rpc_task *task)
617 {
618 if (test_and_set_bit(0, &clp->cl_cb_slot_busy) != 0) {
619 rpc_sleep_on(&clp->cl_cb_waitq, task, NULL);
620 dprintk("%s slot is busy\n", __func__);
621 return false;
622 }
623 return true;
624 }
625
626 /*
627 * TODO: cb_sequence should support referring call lists, cachethis, multiple
628 * slots, and mark callback channel down on communication errors.
629 */
630 static void nfsd4_cb_prepare(struct rpc_task *task, void *calldata)
631 {
632 struct nfsd4_callback *cb = calldata;
633 struct nfs4_delegation *dp = container_of(cb, struct nfs4_delegation, dl_recall);
634 struct nfs4_client *clp = dp->dl_client;
635 u32 minorversion = clp->cl_minorversion;
636
637 cb->cb_minorversion = minorversion;
638 if (minorversion) {
639 if (!nfsd41_cb_get_slot(clp, task))
640 return;
641 }
642 cb->cb_done = false;
643 spin_lock(&clp->cl_lock);
644 list_add(&cb->cb_per_client, &clp->cl_callbacks);
645 spin_unlock(&clp->cl_lock);
646 rpc_call_start(task);
647 }
648
649 static void nfsd4_cb_done(struct rpc_task *task, void *calldata)
650 {
651 struct nfsd4_callback *cb = calldata;
652 struct nfs4_delegation *dp = container_of(cb, struct nfs4_delegation, dl_recall);
653 struct nfs4_client *clp = dp->dl_client;
654
655 dprintk("%s: minorversion=%d\n", __func__,
656 clp->cl_minorversion);
657
658 if (clp->cl_minorversion) {
659 /* No need for lock, access serialized in nfsd4_cb_prepare */
660 ++clp->cl_cb_session->se_cb_seq_nr;
661 clear_bit(0, &clp->cl_cb_slot_busy);
662 rpc_wake_up_next(&clp->cl_cb_waitq);
663 dprintk("%s: freed slot, new seqid=%d\n", __func__,
664 clp->cl_cb_session->se_cb_seq_nr);
665
666 /* We're done looking into the sequence information */
667 task->tk_msg.rpc_resp = NULL;
668 }
669 }
670
671
672 static void nfsd4_cb_recall_done(struct rpc_task *task, void *calldata)
673 {
674 struct nfsd4_callback *cb = calldata;
675 struct nfs4_delegation *dp = container_of(cb, struct nfs4_delegation, dl_recall);
676 struct nfs4_client *clp = dp->dl_client;
677 struct rpc_clnt *current_rpc_client = clp->cl_cb_client;
678
679 nfsd4_cb_done(task, calldata);
680
681 if (current_rpc_client == NULL) {
682 /* We're shutting down; give up. */
683 /* XXX: err, or is it ok just to fall through
684 * and rpc_restart_call? */
685 return;
686 }
687
688 if (cb->cb_done)
689 return;
690 switch (task->tk_status) {
691 case 0:
692 cb->cb_done = true;
693 return;
694 case -EBADHANDLE:
695 case -NFS4ERR_BAD_STATEID:
696 /* Race: client probably got cb_recall
697 * before open reply granting delegation */
698 break;
699 default:
700 /* Network partition? */
701 nfsd4_mark_cb_down(clp, task->tk_status);
702 if (current_rpc_client != task->tk_client) {
703 /* queue a callback on the new connection: */
704 atomic_inc(&dp->dl_count);
705 run_nfsd4_cb(&dp->dl_recall);
706 return;
707 }
708 }
709 if (dp->dl_retries--) {
710 rpc_delay(task, 2*HZ);
711 task->tk_status = 0;
712 rpc_restart_call_prepare(task);
713 return;
714 }
715 nfsd4_mark_cb_down(clp, task->tk_status);
716 cb->cb_done = true;
717 }
718
719 static void nfsd4_cb_recall_release(void *calldata)
720 {
721 struct nfsd4_callback *cb = calldata;
722 struct nfs4_client *clp = cb->cb_clp;
723 struct nfs4_delegation *dp = container_of(cb, struct nfs4_delegation, dl_recall);
724
725 if (cb->cb_done) {
726 spin_lock(&clp->cl_lock);
727 list_del(&cb->cb_per_client);
728 spin_unlock(&clp->cl_lock);
729 nfs4_put_delegation(dp);
730 }
731 }
732
733 static const struct rpc_call_ops nfsd4_cb_recall_ops = {
734 .rpc_call_prepare = nfsd4_cb_prepare,
735 .rpc_call_done = nfsd4_cb_recall_done,
736 .rpc_release = nfsd4_cb_recall_release,
737 };
738
739 int nfsd4_create_callback_queue(void)
740 {
741 callback_wq = create_singlethread_workqueue("nfsd4_callbacks");
742 if (!callback_wq)
743 return -ENOMEM;
744 return 0;
745 }
746
747 void nfsd4_destroy_callback_queue(void)
748 {
749 destroy_workqueue(callback_wq);
750 }
751
752 /* must be called under the state lock */
753 void nfsd4_shutdown_callback(struct nfs4_client *clp)
754 {
755 set_bit(NFSD4_CLIENT_KILL, &clp->cl_cb_flags);
756 /*
757 * Note this won't actually result in a null callback;
758 * instead, nfsd4_do_callback_rpc() will detect the killed
759 * client, destroy the rpc client, and stop:
760 */
761 do_probe_callback(clp);
762 flush_workqueue(callback_wq);
763 }
764
765 static void nfsd4_release_cb(struct nfsd4_callback *cb)
766 {
767 if (cb->cb_ops->rpc_release)
768 cb->cb_ops->rpc_release(cb);
769 }
770
771 /* requires cl_lock: */
772 static struct nfsd4_conn * __nfsd4_find_backchannel(struct nfs4_client *clp)
773 {
774 struct nfsd4_session *s;
775 struct nfsd4_conn *c;
776
777 list_for_each_entry(s, &clp->cl_sessions, se_perclnt) {
778 list_for_each_entry(c, &s->se_conns, cn_persession) {
779 if (c->cn_flags & NFS4_CDFC4_BACK)
780 return c;
781 }
782 }
783 return NULL;
784 }
785
786 static void nfsd4_process_cb_update(struct nfsd4_callback *cb)
787 {
788 struct nfs4_cb_conn conn;
789 struct nfs4_client *clp = cb->cb_clp;
790 struct nfsd4_session *ses = NULL;
791 struct nfsd4_conn *c;
792 int err;
793
794 /*
795 * This is either an update, or the client dying; in either case,
796 * kill the old client:
797 */
798 if (clp->cl_cb_client) {
799 rpc_shutdown_client(clp->cl_cb_client);
800 clp->cl_cb_client = NULL;
801 }
802 if (clp->cl_cb_conn.cb_xprt) {
803 svc_xprt_put(clp->cl_cb_conn.cb_xprt);
804 clp->cl_cb_conn.cb_xprt = NULL;
805 }
806 if (test_bit(NFSD4_CLIENT_KILL, &clp->cl_cb_flags))
807 return;
808 spin_lock(&clp->cl_lock);
809 /*
810 * Only serialized callback code is allowed to clear these
811 * flags; main nfsd code can only set them:
812 */
813 BUG_ON(!clp->cl_cb_flags);
814 clear_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_cb_flags);
815 memcpy(&conn, &cb->cb_clp->cl_cb_conn, sizeof(struct nfs4_cb_conn));
816 c = __nfsd4_find_backchannel(clp);
817 if (c) {
818 svc_xprt_get(c->cn_xprt);
819 conn.cb_xprt = c->cn_xprt;
820 ses = c->cn_session;
821 }
822 spin_unlock(&clp->cl_lock);
823
824 err = setup_callback_client(clp, &conn, ses);
825 if (err) {
826 warn_no_callback_path(clp, err);
827 return;
828 }
829 /* Yay, the callback channel's back! Restart any callbacks: */
830 list_for_each_entry(cb, &clp->cl_callbacks, cb_per_client)
831 run_nfsd4_cb(cb);
832 }
833
834 void nfsd4_do_callback_rpc(struct work_struct *w)
835 {
836 struct nfsd4_callback *cb = container_of(w, struct nfsd4_callback, cb_work);
837 struct nfs4_client *clp = cb->cb_clp;
838 struct rpc_clnt *clnt;
839
840 if (clp->cl_cb_flags)
841 nfsd4_process_cb_update(cb);
842
843 clnt = clp->cl_cb_client;
844 if (!clnt) {
845 /* Callback channel broken, or client killed; give up: */
846 nfsd4_release_cb(cb);
847 return;
848 }
849 rpc_call_async(clnt, &cb->cb_msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN,
850 cb->cb_ops, cb);
851 }
852
853 void nfsd4_cb_recall(struct nfs4_delegation *dp)
854 {
855 struct nfsd4_callback *cb = &dp->dl_recall;
856 struct nfs4_client *clp = dp->dl_client;
857
858 dp->dl_retries = 1;
859 cb->cb_op = dp;
860 cb->cb_clp = clp;
861 cb->cb_msg.rpc_proc = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_RECALL];
862 cb->cb_msg.rpc_argp = cb;
863 cb->cb_msg.rpc_resp = cb;
864 cb->cb_msg.rpc_cred = callback_cred;
865
866 cb->cb_ops = &nfsd4_cb_recall_ops;
867 dp->dl_retries = 1;
868
869 INIT_LIST_HEAD(&cb->cb_per_client);
870 cb->cb_done = true;
871
872 run_nfsd4_cb(&dp->dl_recall);
873 }
Linux kernel - Deliverables
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