nfsd: Use vfs_fsync_range() in nfsd_commit
[linux-2.6.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 "nfsd.h"
36 #include "state.h"
37
38 #define NFSDDBG_FACILITY                NFSDDBG_PROC
39
40 #define NFSPROC4_CB_NULL 0
41 #define NFSPROC4_CB_COMPOUND 1
42 #define NFS4_STATEID_SIZE 16
43
44 /* Index of predefined Linux callback client operations */
45
46 enum {
47         NFSPROC4_CLNT_CB_NULL = 0,
48         NFSPROC4_CLNT_CB_RECALL,
49         NFSPROC4_CLNT_CB_SEQUENCE,
50 };
51
52 enum nfs_cb_opnum4 {
53         OP_CB_RECALL            = 4,
54         OP_CB_SEQUENCE          = 11,
55 };
56
57 #define NFS4_MAXTAGLEN          20
58
59 #define NFS4_enc_cb_null_sz             0
60 #define NFS4_dec_cb_null_sz             0
61 #define cb_compound_enc_hdr_sz          4
62 #define cb_compound_dec_hdr_sz          (3 + (NFS4_MAXTAGLEN >> 2))
63 #define sessionid_sz                    (NFS4_MAX_SESSIONID_LEN >> 2)
64 #define cb_sequence_enc_sz              (sessionid_sz + 4 +             \
65                                         1 /* no referring calls list yet */)
66 #define cb_sequence_dec_sz              (op_dec_sz + sessionid_sz + 4)
67
68 #define op_enc_sz                       1
69 #define op_dec_sz                       2
70 #define enc_nfs4_fh_sz                  (1 + (NFS4_FHSIZE >> 2))
71 #define enc_stateid_sz                  (NFS4_STATEID_SIZE >> 2)
72 #define NFS4_enc_cb_recall_sz           (cb_compound_enc_hdr_sz +       \
73                                         cb_sequence_enc_sz +            \
74                                         1 + enc_stateid_sz +            \
75                                         enc_nfs4_fh_sz)
76
77 #define NFS4_dec_cb_recall_sz           (cb_compound_dec_hdr_sz  +      \
78                                         cb_sequence_dec_sz +            \
79                                         op_dec_sz)
80
81 struct nfs4_rpc_args {
82         void                            *args_op;
83         struct nfsd4_cb_sequence        args_seq;
84 };
85
86 /*
87 * Generic encode routines from fs/nfs/nfs4xdr.c
88 */
89 static inline __be32 *
90 xdr_writemem(__be32 *p, const void *ptr, int nbytes)
91 {
92         int tmp = XDR_QUADLEN(nbytes);
93         if (!tmp)
94                 return p;
95         p[tmp-1] = 0;
96         memcpy(p, ptr, nbytes);
97         return p + tmp;
98 }
99
100 #define WRITE32(n)               *p++ = htonl(n)
101 #define WRITEMEM(ptr,nbytes)     do {                           \
102         p = xdr_writemem(p, ptr, nbytes);                       \
103 } while (0)
104 #define RESERVE_SPACE(nbytes)   do {                            \
105         p = xdr_reserve_space(xdr, nbytes);                     \
106         if (!p) dprintk("NFSD: RESERVE_SPACE(%d) failed in function %s\n", (int) (nbytes), __func__); \
107         BUG_ON(!p);                                             \
108 } while (0)
109
110 /*
111  * Generic decode routines from fs/nfs/nfs4xdr.c
112  */
113 #define DECODE_TAIL                             \
114         status = 0;                             \
115 out:                                            \
116         return status;                          \
117 xdr_error:                                      \
118         dprintk("NFSD: xdr error! (%s:%d)\n", __FILE__, __LINE__); \
119         status = -EIO;                          \
120         goto out
121
122 #define READ32(x)         (x) = ntohl(*p++)
123 #define READ64(x)         do {                  \
124         (x) = (u64)ntohl(*p++) << 32;           \
125         (x) |= ntohl(*p++);                     \
126 } while (0)
127 #define READTIME(x)       do {                  \
128         p++;                                    \
129         (x.tv_sec) = ntohl(*p++);               \
130         (x.tv_nsec) = ntohl(*p++);              \
131 } while (0)
132 #define READ_BUF(nbytes)  do { \
133         p = xdr_inline_decode(xdr, nbytes); \
134         if (!p) { \
135                 dprintk("NFSD: %s: reply buffer overflowed in line %d.\n", \
136                         __func__, __LINE__); \
137                 return -EIO; \
138         } \
139 } while (0)
140
141 struct nfs4_cb_compound_hdr {
142         /* args */
143         u32             ident;  /* minorversion 0 only */
144         u32             nops;
145         __be32          *nops_p;
146         u32             minorversion;
147         /* res */
148         int             status;
149         u32             taglen;
150         char            *tag;
151 };
152
153 static struct {
154 int stat;
155 int errno;
156 } nfs_cb_errtbl[] = {
157         { NFS4_OK,              0               },
158         { NFS4ERR_PERM,         EPERM           },
159         { NFS4ERR_NOENT,        ENOENT          },
160         { NFS4ERR_IO,           EIO             },
161         { NFS4ERR_NXIO,         ENXIO           },
162         { NFS4ERR_ACCESS,       EACCES          },
163         { NFS4ERR_EXIST,        EEXIST          },
164         { NFS4ERR_XDEV,         EXDEV           },
165         { NFS4ERR_NOTDIR,       ENOTDIR         },
166         { NFS4ERR_ISDIR,        EISDIR          },
167         { NFS4ERR_INVAL,        EINVAL          },
168         { NFS4ERR_FBIG,         EFBIG           },
169         { NFS4ERR_NOSPC,        ENOSPC          },
170         { NFS4ERR_ROFS,         EROFS           },
171         { NFS4ERR_MLINK,        EMLINK          },
172         { NFS4ERR_NAMETOOLONG,  ENAMETOOLONG    },
173         { NFS4ERR_NOTEMPTY,     ENOTEMPTY       },
174         { NFS4ERR_DQUOT,        EDQUOT          },
175         { NFS4ERR_STALE,        ESTALE          },
176         { NFS4ERR_BADHANDLE,    EBADHANDLE      },
177         { NFS4ERR_BAD_COOKIE,   EBADCOOKIE      },
178         { NFS4ERR_NOTSUPP,      ENOTSUPP        },
179         { NFS4ERR_TOOSMALL,     ETOOSMALL       },
180         { NFS4ERR_SERVERFAULT,  ESERVERFAULT    },
181         { NFS4ERR_BADTYPE,      EBADTYPE        },
182         { NFS4ERR_LOCKED,       EAGAIN          },
183         { NFS4ERR_RESOURCE,     EREMOTEIO       },
184         { NFS4ERR_SYMLINK,      ELOOP           },
185         { NFS4ERR_OP_ILLEGAL,   EOPNOTSUPP      },
186         { NFS4ERR_DEADLOCK,     EDEADLK         },
187         { -1,                   EIO             }
188 };
189
190 static int
191 nfs_cb_stat_to_errno(int stat)
192 {
193         int i;
194         for (i = 0; nfs_cb_errtbl[i].stat != -1; i++) {
195                 if (nfs_cb_errtbl[i].stat == stat)
196                         return nfs_cb_errtbl[i].errno;
197         }
198         /* If we cannot translate the error, the recovery routines should
199         * handle it.
200         * Note: remaining NFSv4 error codes have values > 10000, so should
201         * not conflict with native Linux error codes.
202         */
203         return stat;
204 }
205
206 /*
207  * XDR encode
208  */
209
210 static void
211 encode_cb_compound_hdr(struct xdr_stream *xdr, struct nfs4_cb_compound_hdr *hdr)
212 {
213         __be32 * p;
214
215         RESERVE_SPACE(16);
216         WRITE32(0);            /* tag length is always 0 */
217         WRITE32(hdr->minorversion);
218         WRITE32(hdr->ident);
219         hdr->nops_p = p;
220         WRITE32(hdr->nops);
221 }
222
223 static void encode_cb_nops(struct nfs4_cb_compound_hdr *hdr)
224 {
225         *hdr->nops_p = htonl(hdr->nops);
226 }
227
228 static void
229 encode_cb_recall(struct xdr_stream *xdr, struct nfs4_delegation *dp,
230                 struct nfs4_cb_compound_hdr *hdr)
231 {
232         __be32 *p;
233         int len = dp->dl_fh.fh_size;
234
235         RESERVE_SPACE(12+sizeof(dp->dl_stateid) + len);
236         WRITE32(OP_CB_RECALL);
237         WRITE32(dp->dl_stateid.si_generation);
238         WRITEMEM(&dp->dl_stateid.si_opaque, sizeof(stateid_opaque_t));
239         WRITE32(0); /* truncate optimization not implemented */
240         WRITE32(len);
241         WRITEMEM(&dp->dl_fh.fh_base, len);
242         hdr->nops++;
243 }
244
245 static void
246 encode_cb_sequence(struct xdr_stream *xdr, struct nfsd4_cb_sequence *args,
247                    struct nfs4_cb_compound_hdr *hdr)
248 {
249         __be32 *p;
250
251         if (hdr->minorversion == 0)
252                 return;
253
254         RESERVE_SPACE(1 + NFS4_MAX_SESSIONID_LEN + 20);
255
256         WRITE32(OP_CB_SEQUENCE);
257         WRITEMEM(args->cbs_clp->cl_sessionid.data, NFS4_MAX_SESSIONID_LEN);
258         WRITE32(args->cbs_clp->cl_cb_seq_nr);
259         WRITE32(0);             /* slotid, always 0 */
260         WRITE32(0);             /* highest slotid always 0 */
261         WRITE32(0);             /* cachethis always 0 */
262         WRITE32(0); /* FIXME: support referring_call_lists */
263         hdr->nops++;
264 }
265
266 static int
267 nfs4_xdr_enc_cb_null(struct rpc_rqst *req, __be32 *p)
268 {
269         struct xdr_stream xdrs, *xdr = &xdrs;
270
271         xdr_init_encode(&xdrs, &req->rq_snd_buf, p);
272         RESERVE_SPACE(0);
273         return 0;
274 }
275
276 static int
277 nfs4_xdr_enc_cb_recall(struct rpc_rqst *req, __be32 *p,
278                 struct nfs4_rpc_args *rpc_args)
279 {
280         struct xdr_stream xdr;
281         struct nfs4_delegation *args = rpc_args->args_op;
282         struct nfs4_cb_compound_hdr hdr = {
283                 .ident = args->dl_ident,
284                 .minorversion = rpc_args->args_seq.cbs_minorversion,
285         };
286
287         xdr_init_encode(&xdr, &req->rq_snd_buf, p);
288         encode_cb_compound_hdr(&xdr, &hdr);
289         encode_cb_sequence(&xdr, &rpc_args->args_seq, &hdr);
290         encode_cb_recall(&xdr, args, &hdr);
291         encode_cb_nops(&hdr);
292         return 0;
293 }
294
295
296 static int
297 decode_cb_compound_hdr(struct xdr_stream *xdr, struct nfs4_cb_compound_hdr *hdr){
298         __be32 *p;
299
300         READ_BUF(8);
301         READ32(hdr->status);
302         READ32(hdr->taglen);
303         READ_BUF(hdr->taglen + 4);
304         hdr->tag = (char *)p;
305         p += XDR_QUADLEN(hdr->taglen);
306         READ32(hdr->nops);
307         return 0;
308 }
309
310 static int
311 decode_cb_op_hdr(struct xdr_stream *xdr, enum nfs_opnum4 expected)
312 {
313         __be32 *p;
314         u32 op;
315         int32_t nfserr;
316
317         READ_BUF(8);
318         READ32(op);
319         if (op != expected) {
320                 dprintk("NFSD: decode_cb_op_hdr: Callback server returned "
321                          " operation %d but we issued a request for %d\n",
322                          op, expected);
323                 return -EIO;
324         }
325         READ32(nfserr);
326         if (nfserr != NFS_OK)
327                 return -nfs_cb_stat_to_errno(nfserr);
328         return 0;
329 }
330
331 /*
332  * Our current back channel implmentation supports a single backchannel
333  * with a single slot.
334  */
335 static int
336 decode_cb_sequence(struct xdr_stream *xdr, struct nfsd4_cb_sequence *res,
337                    struct rpc_rqst *rqstp)
338 {
339         struct nfs4_sessionid id;
340         int status;
341         u32 dummy;
342         __be32 *p;
343
344         if (res->cbs_minorversion == 0)
345                 return 0;
346
347         status = decode_cb_op_hdr(xdr, OP_CB_SEQUENCE);
348         if (status)
349                 return status;
350
351         /*
352          * If the server returns different values for sessionID, slotID or
353          * sequence number, the server is looney tunes.
354          */
355         status = -ESERVERFAULT;
356
357         READ_BUF(NFS4_MAX_SESSIONID_LEN + 16);
358         memcpy(id.data, p, NFS4_MAX_SESSIONID_LEN);
359         p += XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN);
360         if (memcmp(id.data, res->cbs_clp->cl_sessionid.data,
361                    NFS4_MAX_SESSIONID_LEN)) {
362                 dprintk("%s Invalid session id\n", __func__);
363                 goto out;
364         }
365         READ32(dummy);
366         if (dummy != res->cbs_clp->cl_cb_seq_nr) {
367                 dprintk("%s Invalid sequence number\n", __func__);
368                 goto out;
369         }
370         READ32(dummy);  /* slotid must be 0 */
371         if (dummy != 0) {
372                 dprintk("%s Invalid slotid\n", __func__);
373                 goto out;
374         }
375         /* FIXME: process highest slotid and target highest slotid */
376         status = 0;
377 out:
378         return status;
379 }
380
381
382 static int
383 nfs4_xdr_dec_cb_null(struct rpc_rqst *req, __be32 *p)
384 {
385         return 0;
386 }
387
388 static int
389 nfs4_xdr_dec_cb_recall(struct rpc_rqst *rqstp, __be32 *p,
390                 struct nfsd4_cb_sequence *seq)
391 {
392         struct xdr_stream xdr;
393         struct nfs4_cb_compound_hdr hdr;
394         int status;
395
396         xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, p);
397         status = decode_cb_compound_hdr(&xdr, &hdr);
398         if (status)
399                 goto out;
400         if (seq) {
401                 status = decode_cb_sequence(&xdr, seq, rqstp);
402                 if (status)
403                         goto out;
404         }
405         status = decode_cb_op_hdr(&xdr, OP_CB_RECALL);
406 out:
407         return status;
408 }
409
410 /*
411  * RPC procedure tables
412  */
413 #define PROC(proc, call, argtype, restype)                              \
414 [NFSPROC4_CLNT_##proc] = {                                              \
415         .p_proc   = NFSPROC4_CB_##call,                                 \
416         .p_encode = (kxdrproc_t) nfs4_xdr_##argtype,                    \
417         .p_decode = (kxdrproc_t) nfs4_xdr_##restype,                    \
418         .p_arglen = NFS4_##argtype##_sz,                                \
419         .p_replen = NFS4_##restype##_sz,                                \
420         .p_statidx = NFSPROC4_CB_##call,                                \
421         .p_name   = #proc,                                              \
422 }
423
424 static struct rpc_procinfo     nfs4_cb_procedures[] = {
425     PROC(CB_NULL,      NULL,     enc_cb_null,     dec_cb_null),
426     PROC(CB_RECALL,    COMPOUND,   enc_cb_recall,      dec_cb_recall),
427 };
428
429 static struct rpc_version       nfs_cb_version4 = {
430         .number                 = 1,
431         .nrprocs                = ARRAY_SIZE(nfs4_cb_procedures),
432         .procs                  = nfs4_cb_procedures
433 };
434
435 static struct rpc_version *     nfs_cb_version[] = {
436         NULL,
437         &nfs_cb_version4,
438 };
439
440 static struct rpc_program cb_program;
441
442 static struct rpc_stat cb_stats = {
443                 .program        = &cb_program
444 };
445
446 #define NFS4_CALLBACK 0x40000000
447 static struct rpc_program cb_program = {
448                 .name           = "nfs4_cb",
449                 .number         = NFS4_CALLBACK,
450                 .nrvers         = ARRAY_SIZE(nfs_cb_version),
451                 .version        = nfs_cb_version,
452                 .stats          = &cb_stats,
453                 .pipe_dir_name  = "/nfsd4_cb",
454 };
455
456 static int max_cb_time(void)
457 {
458         return max(NFSD_LEASE_TIME/10, (time_t)1) * HZ;
459 }
460
461 /* Reference counting, callback cleanup, etc., all look racy as heck.
462  * And why is cb_set an atomic? */
463
464 int setup_callback_client(struct nfs4_client *clp)
465 {
466         struct nfs4_cb_conn *cb = &clp->cl_cb_conn;
467         struct rpc_timeout      timeparms = {
468                 .to_initval     = max_cb_time(),
469                 .to_retries     = 0,
470         };
471         struct rpc_create_args args = {
472                 .protocol       = XPRT_TRANSPORT_TCP,
473                 .address        = (struct sockaddr *) &cb->cb_addr,
474                 .addrsize       = cb->cb_addrlen,
475                 .timeout        = &timeparms,
476                 .program        = &cb_program,
477                 .prognumber     = cb->cb_prog,
478                 .version        = nfs_cb_version[1]->number,
479                 .authflavor     = clp->cl_flavor,
480                 .flags          = (RPC_CLNT_CREATE_NOPING | RPC_CLNT_CREATE_QUIET),
481                 .client_name    = clp->cl_principal,
482         };
483         struct rpc_clnt *client;
484
485         if (!clp->cl_principal && (clp->cl_flavor >= RPC_AUTH_GSS_KRB5))
486                 return -EINVAL;
487         if (cb->cb_minorversion) {
488                 args.bc_xprt = clp->cl_cb_xprt;
489                 args.protocol = XPRT_TRANSPORT_BC_TCP;
490         }
491         /* Create RPC client */
492         client = rpc_create(&args);
493         if (IS_ERR(client)) {
494                 dprintk("NFSD: couldn't create callback client: %ld\n",
495                         PTR_ERR(client));
496                 return PTR_ERR(client);
497         }
498         cb->cb_client = client;
499         return 0;
500
501 }
502
503 static void warn_no_callback_path(struct nfs4_client *clp, int reason)
504 {
505         dprintk("NFSD: warning: no callback path to client %.*s: error %d\n",
506                 (int)clp->cl_name.len, clp->cl_name.data, reason);
507 }
508
509 static void nfsd4_cb_probe_done(struct rpc_task *task, void *calldata)
510 {
511         struct nfs4_client *clp = calldata;
512
513         if (task->tk_status)
514                 warn_no_callback_path(clp, task->tk_status);
515         else
516                 atomic_set(&clp->cl_cb_conn.cb_set, 1);
517         put_nfs4_client(clp);
518 }
519
520 static const struct rpc_call_ops nfsd4_cb_probe_ops = {
521         .rpc_call_done = nfsd4_cb_probe_done,
522 };
523
524 static struct rpc_cred *callback_cred;
525
526 int set_callback_cred(void)
527 {
528         callback_cred = rpc_lookup_machine_cred();
529         if (!callback_cred)
530                 return -ENOMEM;
531         return 0;
532 }
533
534
535 void do_probe_callback(struct nfs4_client *clp)
536 {
537         struct nfs4_cb_conn *cb = &clp->cl_cb_conn;
538         struct rpc_message msg = {
539                 .rpc_proc       = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_NULL],
540                 .rpc_argp       = clp,
541                 .rpc_cred       = callback_cred
542         };
543         int status;
544
545         status = rpc_call_async(cb->cb_client, &msg, RPC_TASK_SOFT,
546                                 &nfsd4_cb_probe_ops, (void *)clp);
547         if (status) {
548                 warn_no_callback_path(clp, status);
549                 put_nfs4_client(clp);
550         }
551 }
552
553 /*
554  * Set up the callback client and put a NFSPROC4_CB_NULL on the wire...
555  */
556 void
557 nfsd4_probe_callback(struct nfs4_client *clp)
558 {
559         int status;
560
561         BUG_ON(atomic_read(&clp->cl_cb_conn.cb_set));
562
563         status = setup_callback_client(clp);
564         if (status) {
565                 warn_no_callback_path(clp, status);
566                 return;
567         }
568
569         /* the task holds a reference to the nfs4_client struct */
570         atomic_inc(&clp->cl_count);
571
572         do_probe_callback(clp);
573 }
574
575 /*
576  * There's currently a single callback channel slot.
577  * If the slot is available, then mark it busy.  Otherwise, set the
578  * thread for sleeping on the callback RPC wait queue.
579  */
580 static int nfsd41_cb_setup_sequence(struct nfs4_client *clp,
581                 struct rpc_task *task)
582 {
583         struct nfs4_rpc_args *args = task->tk_msg.rpc_argp;
584         u32 *ptr = (u32 *)clp->cl_sessionid.data;
585         int status = 0;
586
587         dprintk("%s: %u:%u:%u:%u\n", __func__,
588                 ptr[0], ptr[1], ptr[2], ptr[3]);
589
590         if (test_and_set_bit(0, &clp->cl_cb_slot_busy) != 0) {
591                 rpc_sleep_on(&clp->cl_cb_waitq, task, NULL);
592                 dprintk("%s slot is busy\n", __func__);
593                 status = -EAGAIN;
594                 goto out;
595         }
596
597         /*
598          * We'll need the clp during XDR encoding and decoding,
599          * and the sequence during decoding to verify the reply
600          */
601         args->args_seq.cbs_clp = clp;
602         task->tk_msg.rpc_resp = &args->args_seq;
603
604 out:
605         dprintk("%s status=%d\n", __func__, status);
606         return status;
607 }
608
609 /*
610  * TODO: cb_sequence should support referring call lists, cachethis, multiple
611  * slots, and mark callback channel down on communication errors.
612  */
613 static void nfsd4_cb_prepare(struct rpc_task *task, void *calldata)
614 {
615         struct nfs4_delegation *dp = calldata;
616         struct nfs4_client *clp = dp->dl_client;
617         struct nfs4_rpc_args *args = task->tk_msg.rpc_argp;
618         u32 minorversion = clp->cl_cb_conn.cb_minorversion;
619         int status = 0;
620
621         args->args_seq.cbs_minorversion = minorversion;
622         if (minorversion) {
623                 status = nfsd41_cb_setup_sequence(clp, task);
624                 if (status) {
625                         if (status != -EAGAIN) {
626                                 /* terminate rpc task */
627                                 task->tk_status = status;
628                                 task->tk_action = NULL;
629                         }
630                         return;
631                 }
632         }
633         rpc_call_start(task);
634 }
635
636 static void nfsd4_cb_done(struct rpc_task *task, void *calldata)
637 {
638         struct nfs4_delegation *dp = calldata;
639         struct nfs4_client *clp = dp->dl_client;
640
641         dprintk("%s: minorversion=%d\n", __func__,
642                 clp->cl_cb_conn.cb_minorversion);
643
644         if (clp->cl_cb_conn.cb_minorversion) {
645                 /* No need for lock, access serialized in nfsd4_cb_prepare */
646                 ++clp->cl_cb_seq_nr;
647                 clear_bit(0, &clp->cl_cb_slot_busy);
648                 rpc_wake_up_next(&clp->cl_cb_waitq);
649                 dprintk("%s: freed slot, new seqid=%d\n", __func__,
650                         clp->cl_cb_seq_nr);
651
652                 /* We're done looking into the sequence information */
653                 task->tk_msg.rpc_resp = NULL;
654         }
655 }
656
657 static void nfsd4_cb_recall_done(struct rpc_task *task, void *calldata)
658 {
659         struct nfs4_delegation *dp = calldata;
660         struct nfs4_client *clp = dp->dl_client;
661
662         nfsd4_cb_done(task, calldata);
663
664         switch (task->tk_status) {
665         case -EIO:
666                 /* Network partition? */
667                 atomic_set(&clp->cl_cb_conn.cb_set, 0);
668                 warn_no_callback_path(clp, task->tk_status);
669         case -EBADHANDLE:
670         case -NFS4ERR_BAD_STATEID:
671                 /* Race: client probably got cb_recall
672                  * before open reply granting delegation */
673                 break;
674         default:
675                 /* success, or error we can't handle */
676                 goto done;
677         }
678         if (dp->dl_retries--) {
679                 rpc_delay(task, 2*HZ);
680                 task->tk_status = 0;
681                 rpc_restart_call(task);
682                 return;
683         } else {
684                 atomic_set(&clp->cl_cb_conn.cb_set, 0);
685                 warn_no_callback_path(clp, task->tk_status);
686         }
687 done:
688         kfree(task->tk_msg.rpc_argp);
689 }
690
691 static void nfsd4_cb_recall_release(void *calldata)
692 {
693         struct nfs4_delegation *dp = calldata;
694         struct nfs4_client *clp = dp->dl_client;
695
696         nfs4_put_delegation(dp);
697         put_nfs4_client(clp);
698 }
699
700 static const struct rpc_call_ops nfsd4_cb_recall_ops = {
701         .rpc_call_prepare = nfsd4_cb_prepare,
702         .rpc_call_done = nfsd4_cb_recall_done,
703         .rpc_release = nfsd4_cb_recall_release,
704 };
705
706 /*
707  * called with dp->dl_count inc'ed.
708  */
709 void
710 nfsd4_cb_recall(struct nfs4_delegation *dp)
711 {
712         struct nfs4_client *clp = dp->dl_client;
713         struct rpc_clnt *clnt = clp->cl_cb_conn.cb_client;
714         struct nfs4_rpc_args *args;
715         struct rpc_message msg = {
716                 .rpc_proc = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_RECALL],
717                 .rpc_cred = callback_cred
718         };
719         int status = -ENOMEM;
720
721         args = kzalloc(sizeof(*args), GFP_KERNEL);
722         if (!args)
723                 goto out;
724         args->args_op = dp;
725         msg.rpc_argp = args;
726         dp->dl_retries = 1;
727         status = rpc_call_async(clnt, &msg, RPC_TASK_SOFT,
728                                 &nfsd4_cb_recall_ops, dp);
729 out:
730         if (status) {
731                 kfree(args);
732                 put_nfs4_client(clp);
733                 nfs4_put_delegation(dp);
734         }
735 }