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[karo-tx-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/xprt.h>
36 #include <linux/sunrpc/svc_xprt.h>
37 #include <linux/slab.h>
38 #include "nfsd.h"
39 #include "state.h"
40 #include "netns.h"
41 #include "xdr4cb.h"
42
43 #define NFSDDBG_FACILITY                NFSDDBG_PROC
44
45 static void nfsd4_mark_cb_fault(struct nfs4_client *, int reason);
46
47 #define NFSPROC4_CB_NULL 0
48 #define NFSPROC4_CB_COMPOUND 1
49
50 /* Index of predefined Linux callback client operations */
51
52 struct nfs4_cb_compound_hdr {
53         /* args */
54         u32             ident;  /* minorversion 0 only */
55         u32             nops;
56         __be32          *nops_p;
57         u32             minorversion;
58         /* res */
59         int             status;
60 };
61
62 /*
63  * Handle decode buffer overflows out-of-line.
64  */
65 static void print_overflow_msg(const char *func, const struct xdr_stream *xdr)
66 {
67         dprintk("NFS: %s prematurely hit the end of our receive buffer. "
68                 "Remaining buffer length is %tu words.\n",
69                 func, xdr->end - xdr->p);
70 }
71
72 static __be32 *xdr_encode_empty_array(__be32 *p)
73 {
74         *p++ = xdr_zero;
75         return p;
76 }
77
78 /*
79  * Encode/decode NFSv4 CB basic data types
80  *
81  * Basic NFSv4 callback data types are defined in section 15 of RFC
82  * 3530: "Network File System (NFS) version 4 Protocol" and section
83  * 20 of RFC 5661: "Network File System (NFS) Version 4 Minor Version
84  * 1 Protocol"
85  */
86
87 /*
88  *      nfs_cb_opnum4
89  *
90  *      enum nfs_cb_opnum4 {
91  *              OP_CB_GETATTR           = 3,
92  *                ...
93  *      };
94  */
95 enum nfs_cb_opnum4 {
96         OP_CB_GETATTR                   = 3,
97         OP_CB_RECALL                    = 4,
98         OP_CB_LAYOUTRECALL              = 5,
99         OP_CB_NOTIFY                    = 6,
100         OP_CB_PUSH_DELEG                = 7,
101         OP_CB_RECALL_ANY                = 8,
102         OP_CB_RECALLABLE_OBJ_AVAIL      = 9,
103         OP_CB_RECALL_SLOT               = 10,
104         OP_CB_SEQUENCE                  = 11,
105         OP_CB_WANTS_CANCELLED           = 12,
106         OP_CB_NOTIFY_LOCK               = 13,
107         OP_CB_NOTIFY_DEVICEID           = 14,
108         OP_CB_ILLEGAL                   = 10044
109 };
110
111 static void encode_nfs_cb_opnum4(struct xdr_stream *xdr, enum nfs_cb_opnum4 op)
112 {
113         __be32 *p;
114
115         p = xdr_reserve_space(xdr, 4);
116         *p = cpu_to_be32(op);
117 }
118
119 /*
120  * nfs_fh4
121  *
122  *      typedef opaque nfs_fh4<NFS4_FHSIZE>;
123  */
124 static void encode_nfs_fh4(struct xdr_stream *xdr, const struct knfsd_fh *fh)
125 {
126         u32 length = fh->fh_size;
127         __be32 *p;
128
129         BUG_ON(length > NFS4_FHSIZE);
130         p = xdr_reserve_space(xdr, 4 + length);
131         xdr_encode_opaque(p, &fh->fh_base, length);
132 }
133
134 /*
135  * stateid4
136  *
137  *      struct stateid4 {
138  *              uint32_t        seqid;
139  *              opaque          other[12];
140  *      };
141  */
142 static void encode_stateid4(struct xdr_stream *xdr, const stateid_t *sid)
143 {
144         __be32 *p;
145
146         p = xdr_reserve_space(xdr, NFS4_STATEID_SIZE);
147         *p++ = cpu_to_be32(sid->si_generation);
148         xdr_encode_opaque_fixed(p, &sid->si_opaque, NFS4_STATEID_OTHER_SIZE);
149 }
150
151 /*
152  * sessionid4
153  *
154  *      typedef opaque sessionid4[NFS4_SESSIONID_SIZE];
155  */
156 static void encode_sessionid4(struct xdr_stream *xdr,
157                               const struct nfsd4_session *session)
158 {
159         __be32 *p;
160
161         p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN);
162         xdr_encode_opaque_fixed(p, session->se_sessionid.data,
163                                         NFS4_MAX_SESSIONID_LEN);
164 }
165
166 /*
167  * nfsstat4
168  */
169 static const struct {
170         int stat;
171         int errno;
172 } nfs_cb_errtbl[] = {
173         { NFS4_OK,              0               },
174         { NFS4ERR_PERM,         -EPERM          },
175         { NFS4ERR_NOENT,        -ENOENT         },
176         { NFS4ERR_IO,           -EIO            },
177         { NFS4ERR_NXIO,         -ENXIO          },
178         { NFS4ERR_ACCESS,       -EACCES         },
179         { NFS4ERR_EXIST,        -EEXIST         },
180         { NFS4ERR_XDEV,         -EXDEV          },
181         { NFS4ERR_NOTDIR,       -ENOTDIR        },
182         { NFS4ERR_ISDIR,        -EISDIR         },
183         { NFS4ERR_INVAL,        -EINVAL         },
184         { NFS4ERR_FBIG,         -EFBIG          },
185         { NFS4ERR_NOSPC,        -ENOSPC         },
186         { NFS4ERR_ROFS,         -EROFS          },
187         { NFS4ERR_MLINK,        -EMLINK         },
188         { NFS4ERR_NAMETOOLONG,  -ENAMETOOLONG   },
189         { NFS4ERR_NOTEMPTY,     -ENOTEMPTY      },
190         { NFS4ERR_DQUOT,        -EDQUOT         },
191         { NFS4ERR_STALE,        -ESTALE         },
192         { NFS4ERR_BADHANDLE,    -EBADHANDLE     },
193         { NFS4ERR_BAD_COOKIE,   -EBADCOOKIE     },
194         { NFS4ERR_NOTSUPP,      -ENOTSUPP       },
195         { NFS4ERR_TOOSMALL,     -ETOOSMALL      },
196         { NFS4ERR_SERVERFAULT,  -ESERVERFAULT   },
197         { NFS4ERR_BADTYPE,      -EBADTYPE       },
198         { NFS4ERR_LOCKED,       -EAGAIN         },
199         { NFS4ERR_RESOURCE,     -EREMOTEIO      },
200         { NFS4ERR_SYMLINK,      -ELOOP          },
201         { NFS4ERR_OP_ILLEGAL,   -EOPNOTSUPP     },
202         { NFS4ERR_DEADLOCK,     -EDEADLK        },
203         { -1,                   -EIO            }
204 };
205
206 /*
207  * If we cannot translate the error, the recovery routines should
208  * handle it.
209  *
210  * Note: remaining NFSv4 error codes have values > 10000, so should
211  * not conflict with native Linux error codes.
212  */
213 static int nfs_cb_stat_to_errno(int status)
214 {
215         int i;
216
217         for (i = 0; nfs_cb_errtbl[i].stat != -1; i++) {
218                 if (nfs_cb_errtbl[i].stat == status)
219                         return nfs_cb_errtbl[i].errno;
220         }
221
222         dprintk("NFSD: Unrecognized NFS CB status value: %u\n", status);
223         return -status;
224 }
225
226 static int decode_cb_op_status(struct xdr_stream *xdr, enum nfs_opnum4 expected,
227                                int *status)
228 {
229         __be32 *p;
230         u32 op;
231
232         p = xdr_inline_decode(xdr, 4 + 4);
233         if (unlikely(p == NULL))
234                 goto out_overflow;
235         op = be32_to_cpup(p++);
236         if (unlikely(op != expected))
237                 goto out_unexpected;
238         *status = nfs_cb_stat_to_errno(be32_to_cpup(p));
239         return 0;
240 out_overflow:
241         print_overflow_msg(__func__, xdr);
242         return -EIO;
243 out_unexpected:
244         dprintk("NFSD: Callback server returned operation %d but "
245                 "we issued a request for %d\n", op, expected);
246         return -EIO;
247 }
248
249 /*
250  * CB_COMPOUND4args
251  *
252  *      struct CB_COMPOUND4args {
253  *              utf8str_cs      tag;
254  *              uint32_t        minorversion;
255  *              uint32_t        callback_ident;
256  *              nfs_cb_argop4   argarray<>;
257  *      };
258 */
259 static void encode_cb_compound4args(struct xdr_stream *xdr,
260                                     struct nfs4_cb_compound_hdr *hdr)
261 {
262         __be32 * p;
263
264         p = xdr_reserve_space(xdr, 4 + 4 + 4 + 4);
265         p = xdr_encode_empty_array(p);          /* empty tag */
266         *p++ = cpu_to_be32(hdr->minorversion);
267         *p++ = cpu_to_be32(hdr->ident);
268
269         hdr->nops_p = p;
270         *p = cpu_to_be32(hdr->nops);            /* argarray element count */
271 }
272
273 /*
274  * Update argarray element count
275  */
276 static void encode_cb_nops(struct nfs4_cb_compound_hdr *hdr)
277 {
278         BUG_ON(hdr->nops > NFS4_MAX_BACK_CHANNEL_OPS);
279         *hdr->nops_p = cpu_to_be32(hdr->nops);
280 }
281
282 /*
283  * CB_COMPOUND4res
284  *
285  *      struct CB_COMPOUND4res {
286  *              nfsstat4        status;
287  *              utf8str_cs      tag;
288  *              nfs_cb_resop4   resarray<>;
289  *      };
290  */
291 static int decode_cb_compound4res(struct xdr_stream *xdr,
292                                   struct nfs4_cb_compound_hdr *hdr)
293 {
294         u32 length;
295         __be32 *p;
296
297         p = xdr_inline_decode(xdr, 4 + 4);
298         if (unlikely(p == NULL))
299                 goto out_overflow;
300         hdr->status = be32_to_cpup(p++);
301         /* Ignore the tag */
302         length = be32_to_cpup(p++);
303         p = xdr_inline_decode(xdr, length + 4);
304         if (unlikely(p == NULL))
305                 goto out_overflow;
306         p += XDR_QUADLEN(length);
307         hdr->nops = be32_to_cpup(p);
308         return 0;
309 out_overflow:
310         print_overflow_msg(__func__, xdr);
311         return -EIO;
312 }
313
314 /*
315  * CB_RECALL4args
316  *
317  *      struct CB_RECALL4args {
318  *              stateid4        stateid;
319  *              bool            truncate;
320  *              nfs_fh4         fh;
321  *      };
322  */
323 static void encode_cb_recall4args(struct xdr_stream *xdr,
324                                   const struct nfs4_delegation *dp,
325                                   struct nfs4_cb_compound_hdr *hdr)
326 {
327         __be32 *p;
328
329         encode_nfs_cb_opnum4(xdr, OP_CB_RECALL);
330         encode_stateid4(xdr, &dp->dl_stid.sc_stateid);
331
332         p = xdr_reserve_space(xdr, 4);
333         *p++ = xdr_zero;                        /* truncate */
334
335         encode_nfs_fh4(xdr, &dp->dl_stid.sc_file->fi_fhandle);
336
337         hdr->nops++;
338 }
339
340 /*
341  * CB_SEQUENCE4args
342  *
343  *      struct CB_SEQUENCE4args {
344  *              sessionid4              csa_sessionid;
345  *              sequenceid4             csa_sequenceid;
346  *              slotid4                 csa_slotid;
347  *              slotid4                 csa_highest_slotid;
348  *              bool                    csa_cachethis;
349  *              referring_call_list4    csa_referring_call_lists<>;
350  *      };
351  */
352 static void encode_cb_sequence4args(struct xdr_stream *xdr,
353                                     const struct nfsd4_callback *cb,
354                                     struct nfs4_cb_compound_hdr *hdr)
355 {
356         struct nfsd4_session *session = cb->cb_clp->cl_cb_session;
357         __be32 *p;
358
359         if (hdr->minorversion == 0)
360                 return;
361
362         encode_nfs_cb_opnum4(xdr, OP_CB_SEQUENCE);
363         encode_sessionid4(xdr, session);
364
365         p = xdr_reserve_space(xdr, 4 + 4 + 4 + 4 + 4);
366         *p++ = cpu_to_be32(session->se_cb_seq_nr);      /* csa_sequenceid */
367         *p++ = xdr_zero;                        /* csa_slotid */
368         *p++ = xdr_zero;                        /* csa_highest_slotid */
369         *p++ = xdr_zero;                        /* csa_cachethis */
370         xdr_encode_empty_array(p);              /* csa_referring_call_lists */
371
372         hdr->nops++;
373 }
374
375 /*
376  * CB_SEQUENCE4resok
377  *
378  *      struct CB_SEQUENCE4resok {
379  *              sessionid4      csr_sessionid;
380  *              sequenceid4     csr_sequenceid;
381  *              slotid4         csr_slotid;
382  *              slotid4         csr_highest_slotid;
383  *              slotid4         csr_target_highest_slotid;
384  *      };
385  *
386  *      union CB_SEQUENCE4res switch (nfsstat4 csr_status) {
387  *      case NFS4_OK:
388  *              CB_SEQUENCE4resok       csr_resok4;
389  *      default:
390  *              void;
391  *      };
392  *
393  * Our current back channel implmentation supports a single backchannel
394  * with a single slot.
395  */
396 static int decode_cb_sequence4resok(struct xdr_stream *xdr,
397                                     struct nfsd4_callback *cb)
398 {
399         struct nfsd4_session *session = cb->cb_clp->cl_cb_session;
400         int status = -ESERVERFAULT;
401         __be32 *p;
402         u32 dummy;
403
404         /*
405          * If the server returns different values for sessionID, slotID or
406          * sequence number, the server is looney tunes.
407          */
408         p = xdr_inline_decode(xdr, NFS4_MAX_SESSIONID_LEN + 4 + 4 + 4 + 4);
409         if (unlikely(p == NULL))
410                 goto out_overflow;
411
412         if (memcmp(p, session->se_sessionid.data, NFS4_MAX_SESSIONID_LEN)) {
413                 dprintk("NFS: %s Invalid session id\n", __func__);
414                 goto out;
415         }
416         p += XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN);
417
418         dummy = be32_to_cpup(p++);
419         if (dummy != session->se_cb_seq_nr) {
420                 dprintk("NFS: %s Invalid sequence number\n", __func__);
421                 goto out;
422         }
423
424         dummy = be32_to_cpup(p++);
425         if (dummy != 0) {
426                 dprintk("NFS: %s Invalid slotid\n", __func__);
427                 goto out;
428         }
429
430         /*
431          * FIXME: process highest slotid and target highest slotid
432          */
433         status = 0;
434 out:
435         cb->cb_seq_status = status;
436         return status;
437 out_overflow:
438         print_overflow_msg(__func__, xdr);
439         status = -EIO;
440         goto out;
441 }
442
443 static int decode_cb_sequence4res(struct xdr_stream *xdr,
444                                   struct nfsd4_callback *cb)
445 {
446         int status;
447
448         if (cb->cb_clp->cl_minorversion == 0)
449                 return 0;
450
451         status = decode_cb_op_status(xdr, OP_CB_SEQUENCE, &cb->cb_seq_status);
452         if (unlikely(status || cb->cb_seq_status))
453                 return status;
454
455         return decode_cb_sequence4resok(xdr, cb);
456 }
457
458 /*
459  * NFSv4.0 and NFSv4.1 XDR encode functions
460  *
461  * NFSv4.0 callback argument types are defined in section 15 of RFC
462  * 3530: "Network File System (NFS) version 4 Protocol" and section 20
463  * of RFC 5661:  "Network File System (NFS) Version 4 Minor Version 1
464  * Protocol".
465  */
466
467 /*
468  * NB: Without this zero space reservation, callbacks over krb5p fail
469  */
470 static void nfs4_xdr_enc_cb_null(struct rpc_rqst *req, struct xdr_stream *xdr,
471                                  void *__unused)
472 {
473         xdr_reserve_space(xdr, 0);
474 }
475
476 /*
477  * 20.2. Operation 4: CB_RECALL - Recall a Delegation
478  */
479 static void nfs4_xdr_enc_cb_recall(struct rpc_rqst *req, struct xdr_stream *xdr,
480                                    const struct nfsd4_callback *cb)
481 {
482         const struct nfs4_delegation *dp = cb_to_delegation(cb);
483         struct nfs4_cb_compound_hdr hdr = {
484                 .ident = cb->cb_clp->cl_cb_ident,
485                 .minorversion = cb->cb_clp->cl_minorversion,
486         };
487
488         encode_cb_compound4args(xdr, &hdr);
489         encode_cb_sequence4args(xdr, cb, &hdr);
490         encode_cb_recall4args(xdr, dp, &hdr);
491         encode_cb_nops(&hdr);
492 }
493
494
495 /*
496  * NFSv4.0 and NFSv4.1 XDR decode functions
497  *
498  * NFSv4.0 callback result types are defined in section 15 of RFC
499  * 3530: "Network File System (NFS) version 4 Protocol" and section 20
500  * of RFC 5661:  "Network File System (NFS) Version 4 Minor Version 1
501  * Protocol".
502  */
503
504 static int nfs4_xdr_dec_cb_null(struct rpc_rqst *req, struct xdr_stream *xdr,
505                                 void *__unused)
506 {
507         return 0;
508 }
509
510 /*
511  * 20.2. Operation 4: CB_RECALL - Recall a Delegation
512  */
513 static int nfs4_xdr_dec_cb_recall(struct rpc_rqst *rqstp,
514                                   struct xdr_stream *xdr,
515                                   struct nfsd4_callback *cb)
516 {
517         struct nfs4_cb_compound_hdr hdr;
518         int status;
519
520         status = decode_cb_compound4res(xdr, &hdr);
521         if (unlikely(status))
522                 return status;
523
524         if (cb != NULL) {
525                 status = decode_cb_sequence4res(xdr, cb);
526                 if (unlikely(status || cb->cb_seq_status))
527                         return status;
528         }
529
530         return decode_cb_op_status(xdr, OP_CB_RECALL, &cb->cb_status);
531 }
532
533 #ifdef CONFIG_NFSD_PNFS
534 /*
535  * CB_LAYOUTRECALL4args
536  *
537  *      struct layoutrecall_file4 {
538  *              nfs_fh4         lor_fh;
539  *              offset4         lor_offset;
540  *              length4         lor_length;
541  *              stateid4        lor_stateid;
542  *      };
543  *
544  *      union layoutrecall4 switch(layoutrecall_type4 lor_recalltype) {
545  *      case LAYOUTRECALL4_FILE:
546  *              layoutrecall_file4 lor_layout;
547  *      case LAYOUTRECALL4_FSID:
548  *              fsid4              lor_fsid;
549  *      case LAYOUTRECALL4_ALL:
550  *              void;
551  *      };
552  *
553  *      struct CB_LAYOUTRECALL4args {
554  *              layouttype4             clora_type;
555  *              layoutiomode4           clora_iomode;
556  *              bool                    clora_changed;
557  *              layoutrecall4           clora_recall;
558  *      };
559  */
560 static void encode_cb_layout4args(struct xdr_stream *xdr,
561                                   const struct nfs4_layout_stateid *ls,
562                                   struct nfs4_cb_compound_hdr *hdr)
563 {
564         __be32 *p;
565
566         BUG_ON(hdr->minorversion == 0);
567
568         p = xdr_reserve_space(xdr, 5 * 4);
569         *p++ = cpu_to_be32(OP_CB_LAYOUTRECALL);
570         *p++ = cpu_to_be32(ls->ls_layout_type);
571         *p++ = cpu_to_be32(IOMODE_ANY);
572         *p++ = cpu_to_be32(1);
573         *p = cpu_to_be32(RETURN_FILE);
574
575         encode_nfs_fh4(xdr, &ls->ls_stid.sc_file->fi_fhandle);
576
577         p = xdr_reserve_space(xdr, 2 * 8);
578         p = xdr_encode_hyper(p, 0);
579         xdr_encode_hyper(p, NFS4_MAX_UINT64);
580
581         encode_stateid4(xdr, &ls->ls_recall_sid);
582
583         hdr->nops++;
584 }
585
586 static void nfs4_xdr_enc_cb_layout(struct rpc_rqst *req,
587                                    struct xdr_stream *xdr,
588                                    const struct nfsd4_callback *cb)
589 {
590         const struct nfs4_layout_stateid *ls =
591                 container_of(cb, struct nfs4_layout_stateid, ls_recall);
592         struct nfs4_cb_compound_hdr hdr = {
593                 .ident = 0,
594                 .minorversion = cb->cb_clp->cl_minorversion,
595         };
596
597         encode_cb_compound4args(xdr, &hdr);
598         encode_cb_sequence4args(xdr, cb, &hdr);
599         encode_cb_layout4args(xdr, ls, &hdr);
600         encode_cb_nops(&hdr);
601 }
602
603 static int nfs4_xdr_dec_cb_layout(struct rpc_rqst *rqstp,
604                                   struct xdr_stream *xdr,
605                                   struct nfsd4_callback *cb)
606 {
607         struct nfs4_cb_compound_hdr hdr;
608         int status;
609
610         status = decode_cb_compound4res(xdr, &hdr);
611         if (unlikely(status))
612                 return status;
613
614         if (cb) {
615                 status = decode_cb_sequence4res(xdr, cb);
616                 if (unlikely(status || cb->cb_seq_status))
617                         return status;
618         }
619         return decode_cb_op_status(xdr, OP_CB_LAYOUTRECALL, &cb->cb_status);
620 }
621 #endif /* CONFIG_NFSD_PNFS */
622
623 static void encode_stateowner(struct xdr_stream *xdr, struct nfs4_stateowner *so)
624 {
625         __be32  *p;
626
627         p = xdr_reserve_space(xdr, 8 + 4 + so->so_owner.len);
628         p = xdr_encode_opaque_fixed(p, &so->so_client->cl_clientid, 8);
629         xdr_encode_opaque(p, so->so_owner.data, so->so_owner.len);
630 }
631
632 static void nfs4_xdr_enc_cb_notify_lock(struct rpc_rqst *req,
633                                         struct xdr_stream *xdr,
634                                         const struct nfsd4_callback *cb)
635 {
636         const struct nfsd4_blocked_lock *nbl =
637                 container_of(cb, struct nfsd4_blocked_lock, nbl_cb);
638         struct nfs4_lockowner *lo = (struct nfs4_lockowner *)nbl->nbl_lock.fl_owner;
639         struct nfs4_cb_compound_hdr hdr = {
640                 .ident = 0,
641                 .minorversion = cb->cb_clp->cl_minorversion,
642         };
643
644         __be32 *p;
645
646         BUG_ON(hdr.minorversion == 0);
647
648         encode_cb_compound4args(xdr, &hdr);
649         encode_cb_sequence4args(xdr, cb, &hdr);
650
651         p = xdr_reserve_space(xdr, 4);
652         *p = cpu_to_be32(OP_CB_NOTIFY_LOCK);
653         encode_nfs_fh4(xdr, &nbl->nbl_fh);
654         encode_stateowner(xdr, &lo->lo_owner);
655         hdr.nops++;
656
657         encode_cb_nops(&hdr);
658 }
659
660 static int nfs4_xdr_dec_cb_notify_lock(struct rpc_rqst *rqstp,
661                                         struct xdr_stream *xdr,
662                                         struct nfsd4_callback *cb)
663 {
664         struct nfs4_cb_compound_hdr hdr;
665         int status;
666
667         status = decode_cb_compound4res(xdr, &hdr);
668         if (unlikely(status))
669                 return status;
670
671         if (cb) {
672                 status = decode_cb_sequence4res(xdr, cb);
673                 if (unlikely(status || cb->cb_seq_status))
674                         return status;
675         }
676         return decode_cb_op_status(xdr, OP_CB_NOTIFY_LOCK, &cb->cb_status);
677 }
678
679 /*
680  * RPC procedure tables
681  */
682 #define PROC(proc, call, argtype, restype)                              \
683 [NFSPROC4_CLNT_##proc] = {                                              \
684         .p_proc    = NFSPROC4_CB_##call,                                \
685         .p_encode  = (kxdreproc_t)nfs4_xdr_enc_##argtype,               \
686         .p_decode  = (kxdrdproc_t)nfs4_xdr_dec_##restype,               \
687         .p_arglen  = NFS4_enc_##argtype##_sz,                           \
688         .p_replen  = NFS4_dec_##restype##_sz,                           \
689         .p_statidx = NFSPROC4_CB_##call,                                \
690         .p_name    = #proc,                                             \
691 }
692
693 static struct rpc_procinfo nfs4_cb_procedures[] = {
694         PROC(CB_NULL,   NULL,           cb_null,        cb_null),
695         PROC(CB_RECALL, COMPOUND,       cb_recall,      cb_recall),
696 #ifdef CONFIG_NFSD_PNFS
697         PROC(CB_LAYOUT, COMPOUND,       cb_layout,      cb_layout),
698 #endif
699         PROC(CB_NOTIFY_LOCK,    COMPOUND,       cb_notify_lock, cb_notify_lock),
700 };
701
702 static struct rpc_version nfs_cb_version4 = {
703 /*
704  * Note on the callback rpc program version number: despite language in rfc
705  * 5661 section 18.36.3 requiring servers to use 4 in this field, the
706  * official xdr descriptions for both 4.0 and 4.1 specify version 1, and
707  * in practice that appears to be what implementations use.  The section
708  * 18.36.3 language is expected to be fixed in an erratum.
709  */
710         .number                 = 1,
711         .nrprocs                = ARRAY_SIZE(nfs4_cb_procedures),
712         .procs                  = nfs4_cb_procedures
713 };
714
715 static const struct rpc_version *nfs_cb_version[] = {
716         &nfs_cb_version4,
717 };
718
719 static const struct rpc_program cb_program;
720
721 static struct rpc_stat cb_stats = {
722         .program                = &cb_program
723 };
724
725 #define NFS4_CALLBACK 0x40000000
726 static const struct rpc_program cb_program = {
727         .name                   = "nfs4_cb",
728         .number                 = NFS4_CALLBACK,
729         .nrvers                 = ARRAY_SIZE(nfs_cb_version),
730         .version                = nfs_cb_version,
731         .stats                  = &cb_stats,
732         .pipe_dir_name          = "nfsd4_cb",
733 };
734
735 static int max_cb_time(struct net *net)
736 {
737         struct nfsd_net *nn = net_generic(net, nfsd_net_id);
738         return max(nn->nfsd4_lease/10, (time_t)1) * HZ;
739 }
740
741 static struct rpc_cred *callback_cred;
742
743 int set_callback_cred(void)
744 {
745         if (callback_cred)
746                 return 0;
747         callback_cred = rpc_lookup_machine_cred("nfs");
748         if (!callback_cred)
749                 return -ENOMEM;
750         return 0;
751 }
752
753 void cleanup_callback_cred(void)
754 {
755         if (callback_cred) {
756                 put_rpccred(callback_cred);
757                 callback_cred = NULL;
758         }
759 }
760
761 static struct rpc_cred *get_backchannel_cred(struct nfs4_client *clp, struct rpc_clnt *client, struct nfsd4_session *ses)
762 {
763         if (clp->cl_minorversion == 0) {
764                 return get_rpccred(callback_cred);
765         } else {
766                 struct rpc_auth *auth = client->cl_auth;
767                 struct auth_cred acred = {};
768
769                 acred.uid = ses->se_cb_sec.uid;
770                 acred.gid = ses->se_cb_sec.gid;
771                 return auth->au_ops->lookup_cred(client->cl_auth, &acred, 0);
772         }
773 }
774
775 static int setup_callback_client(struct nfs4_client *clp, struct nfs4_cb_conn *conn, struct nfsd4_session *ses)
776 {
777         int maxtime = max_cb_time(clp->net);
778         struct rpc_timeout      timeparms = {
779                 .to_initval     = maxtime,
780                 .to_retries     = 0,
781                 .to_maxval      = maxtime,
782         };
783         struct rpc_create_args args = {
784                 .net            = clp->net,
785                 .address        = (struct sockaddr *) &conn->cb_addr,
786                 .addrsize       = conn->cb_addrlen,
787                 .saddress       = (struct sockaddr *) &conn->cb_saddr,
788                 .timeout        = &timeparms,
789                 .program        = &cb_program,
790                 .version        = 0,
791                 .flags          = (RPC_CLNT_CREATE_NOPING | RPC_CLNT_CREATE_QUIET),
792         };
793         struct rpc_clnt *client;
794         struct rpc_cred *cred;
795
796         if (clp->cl_minorversion == 0) {
797                 if (!clp->cl_cred.cr_principal &&
798                                 (clp->cl_cred.cr_flavor >= RPC_AUTH_GSS_KRB5))
799                         return -EINVAL;
800                 args.client_name = clp->cl_cred.cr_principal;
801                 args.prognumber = conn->cb_prog;
802                 args.protocol = XPRT_TRANSPORT_TCP;
803                 args.authflavor = clp->cl_cred.cr_flavor;
804                 clp->cl_cb_ident = conn->cb_ident;
805         } else {
806                 if (!conn->cb_xprt)
807                         return -EINVAL;
808                 clp->cl_cb_conn.cb_xprt = conn->cb_xprt;
809                 clp->cl_cb_session = ses;
810                 args.bc_xprt = conn->cb_xprt;
811                 args.prognumber = clp->cl_cb_session->se_cb_prog;
812                 args.protocol = conn->cb_xprt->xpt_class->xcl_ident |
813                                 XPRT_TRANSPORT_BC;
814                 args.authflavor = ses->se_cb_sec.flavor;
815         }
816         /* Create RPC client */
817         client = rpc_create(&args);
818         if (IS_ERR(client)) {
819                 dprintk("NFSD: couldn't create callback client: %ld\n",
820                         PTR_ERR(client));
821                 return PTR_ERR(client);
822         }
823         cred = get_backchannel_cred(clp, client, ses);
824         if (IS_ERR(cred)) {
825                 rpc_shutdown_client(client);
826                 return PTR_ERR(cred);
827         }
828         clp->cl_cb_client = client;
829         clp->cl_cb_cred = cred;
830         return 0;
831 }
832
833 static void warn_no_callback_path(struct nfs4_client *clp, int reason)
834 {
835         dprintk("NFSD: warning: no callback path to client %.*s: error %d\n",
836                 (int)clp->cl_name.len, clp->cl_name.data, reason);
837 }
838
839 static void nfsd4_mark_cb_down(struct nfs4_client *clp, int reason)
840 {
841         if (test_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags))
842                 return;
843         clp->cl_cb_state = NFSD4_CB_DOWN;
844         warn_no_callback_path(clp, reason);
845 }
846
847 static void nfsd4_mark_cb_fault(struct nfs4_client *clp, int reason)
848 {
849         if (test_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags))
850                 return;
851         clp->cl_cb_state = NFSD4_CB_FAULT;
852         warn_no_callback_path(clp, reason);
853 }
854
855 static void nfsd4_cb_probe_done(struct rpc_task *task, void *calldata)
856 {
857         struct nfs4_client *clp = container_of(calldata, struct nfs4_client, cl_cb_null);
858
859         if (task->tk_status)
860                 nfsd4_mark_cb_down(clp, task->tk_status);
861         else
862                 clp->cl_cb_state = NFSD4_CB_UP;
863 }
864
865 static const struct rpc_call_ops nfsd4_cb_probe_ops = {
866         /* XXX: release method to ensure we set the cb channel down if
867          * necessary on early failure? */
868         .rpc_call_done = nfsd4_cb_probe_done,
869 };
870
871 static struct workqueue_struct *callback_wq;
872
873 /*
874  * Poke the callback thread to process any updates to the callback
875  * parameters, and send a null probe.
876  */
877 void nfsd4_probe_callback(struct nfs4_client *clp)
878 {
879         clp->cl_cb_state = NFSD4_CB_UNKNOWN;
880         set_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags);
881         nfsd4_run_cb(&clp->cl_cb_null);
882 }
883
884 void nfsd4_probe_callback_sync(struct nfs4_client *clp)
885 {
886         nfsd4_probe_callback(clp);
887         flush_workqueue(callback_wq);
888 }
889
890 void nfsd4_change_callback(struct nfs4_client *clp, struct nfs4_cb_conn *conn)
891 {
892         clp->cl_cb_state = NFSD4_CB_UNKNOWN;
893         spin_lock(&clp->cl_lock);
894         memcpy(&clp->cl_cb_conn, conn, sizeof(struct nfs4_cb_conn));
895         spin_unlock(&clp->cl_lock);
896 }
897
898 /*
899  * There's currently a single callback channel slot.
900  * If the slot is available, then mark it busy.  Otherwise, set the
901  * thread for sleeping on the callback RPC wait queue.
902  */
903 static bool nfsd41_cb_get_slot(struct nfs4_client *clp, struct rpc_task *task)
904 {
905         if (test_and_set_bit(0, &clp->cl_cb_slot_busy) != 0) {
906                 rpc_sleep_on(&clp->cl_cb_waitq, task, NULL);
907                 /* Race breaker */
908                 if (test_and_set_bit(0, &clp->cl_cb_slot_busy) != 0) {
909                         dprintk("%s slot is busy\n", __func__);
910                         return false;
911                 }
912                 rpc_wake_up_queued_task(&clp->cl_cb_waitq, task);
913         }
914         return true;
915 }
916
917 /*
918  * TODO: cb_sequence should support referring call lists, cachethis, multiple
919  * slots, and mark callback channel down on communication errors.
920  */
921 static void nfsd4_cb_prepare(struct rpc_task *task, void *calldata)
922 {
923         struct nfsd4_callback *cb = calldata;
924         struct nfs4_client *clp = cb->cb_clp;
925         u32 minorversion = clp->cl_minorversion;
926
927         /*
928          * cb_seq_status is only set in decode_cb_sequence4res,
929          * and so will remain 1 if an rpc level failure occurs.
930          */
931         cb->cb_seq_status = 1;
932         cb->cb_status = 0;
933         if (minorversion) {
934                 if (!nfsd41_cb_get_slot(clp, task))
935                         return;
936         }
937         rpc_call_start(task);
938 }
939
940 static bool nfsd4_cb_sequence_done(struct rpc_task *task, struct nfsd4_callback *cb)
941 {
942         struct nfs4_client *clp = cb->cb_clp;
943         struct nfsd4_session *session = clp->cl_cb_session;
944         bool ret = true;
945
946         if (!clp->cl_minorversion) {
947                 /*
948                  * If the backchannel connection was shut down while this
949                  * task was queued, we need to resubmit it after setting up
950                  * a new backchannel connection.
951                  *
952                  * Note that if we lost our callback connection permanently
953                  * the submission code will error out, so we don't need to
954                  * handle that case here.
955                  */
956                 if (task->tk_flags & RPC_TASK_KILLED)
957                         goto need_restart;
958
959                 return true;
960         }
961
962         switch (cb->cb_seq_status) {
963         case 0:
964                 /*
965                  * No need for lock, access serialized in nfsd4_cb_prepare
966                  *
967                  * RFC5661 20.9.3
968                  * If CB_SEQUENCE returns an error, then the state of the slot
969                  * (sequence ID, cached reply) MUST NOT change.
970                  */
971                 ++session->se_cb_seq_nr;
972                 break;
973         case -ESERVERFAULT:
974                 ++session->se_cb_seq_nr;
975         case 1:
976         case -NFS4ERR_BADSESSION:
977                 nfsd4_mark_cb_fault(cb->cb_clp, cb->cb_seq_status);
978                 ret = false;
979                 break;
980         case -NFS4ERR_DELAY:
981                 if (!rpc_restart_call(task))
982                         goto out;
983
984                 rpc_delay(task, 2 * HZ);
985                 return false;
986         case -NFS4ERR_BADSLOT:
987                 goto retry_nowait;
988         case -NFS4ERR_SEQ_MISORDERED:
989                 if (session->se_cb_seq_nr != 1) {
990                         session->se_cb_seq_nr = 1;
991                         goto retry_nowait;
992                 }
993                 break;
994         default:
995                 dprintk("%s: unprocessed error %d\n", __func__,
996                         cb->cb_seq_status);
997         }
998
999         clear_bit(0, &clp->cl_cb_slot_busy);
1000         rpc_wake_up_next(&clp->cl_cb_waitq);
1001         dprintk("%s: freed slot, new seqid=%d\n", __func__,
1002                 clp->cl_cb_session->se_cb_seq_nr);
1003
1004         if (task->tk_flags & RPC_TASK_KILLED)
1005                 goto need_restart;
1006 out:
1007         return ret;
1008 retry_nowait:
1009         if (rpc_restart_call_prepare(task))
1010                 ret = false;
1011         goto out;
1012 need_restart:
1013         task->tk_status = 0;
1014         cb->cb_need_restart = true;
1015         return false;
1016 }
1017
1018 static void nfsd4_cb_done(struct rpc_task *task, void *calldata)
1019 {
1020         struct nfsd4_callback *cb = calldata;
1021         struct nfs4_client *clp = cb->cb_clp;
1022
1023         dprintk("%s: minorversion=%d\n", __func__,
1024                 clp->cl_minorversion);
1025
1026         if (!nfsd4_cb_sequence_done(task, cb))
1027                 return;
1028
1029         if (cb->cb_status) {
1030                 WARN_ON_ONCE(task->tk_status);
1031                 task->tk_status = cb->cb_status;
1032         }
1033
1034         switch (cb->cb_ops->done(cb, task)) {
1035         case 0:
1036                 task->tk_status = 0;
1037                 rpc_restart_call_prepare(task);
1038                 return;
1039         case 1:
1040                 break;
1041         case -1:
1042                 /* Network partition? */
1043                 nfsd4_mark_cb_down(clp, task->tk_status);
1044                 break;
1045         default:
1046                 BUG();
1047         }
1048 }
1049
1050 static void nfsd4_cb_release(void *calldata)
1051 {
1052         struct nfsd4_callback *cb = calldata;
1053
1054         if (cb->cb_need_restart)
1055                 nfsd4_run_cb(cb);
1056         else
1057                 cb->cb_ops->release(cb);
1058
1059 }
1060
1061 static const struct rpc_call_ops nfsd4_cb_ops = {
1062         .rpc_call_prepare = nfsd4_cb_prepare,
1063         .rpc_call_done = nfsd4_cb_done,
1064         .rpc_release = nfsd4_cb_release,
1065 };
1066
1067 int nfsd4_create_callback_queue(void)
1068 {
1069         callback_wq = alloc_ordered_workqueue("nfsd4_callbacks", 0);
1070         if (!callback_wq)
1071                 return -ENOMEM;
1072         return 0;
1073 }
1074
1075 void nfsd4_destroy_callback_queue(void)
1076 {
1077         destroy_workqueue(callback_wq);
1078 }
1079
1080 /* must be called under the state lock */
1081 void nfsd4_shutdown_callback(struct nfs4_client *clp)
1082 {
1083         set_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags);
1084         /*
1085          * Note this won't actually result in a null callback;
1086          * instead, nfsd4_run_cb_null() will detect the killed
1087          * client, destroy the rpc client, and stop:
1088          */
1089         nfsd4_run_cb(&clp->cl_cb_null);
1090         flush_workqueue(callback_wq);
1091 }
1092
1093 /* requires cl_lock: */
1094 static struct nfsd4_conn * __nfsd4_find_backchannel(struct nfs4_client *clp)
1095 {
1096         struct nfsd4_session *s;
1097         struct nfsd4_conn *c;
1098
1099         list_for_each_entry(s, &clp->cl_sessions, se_perclnt) {
1100                 list_for_each_entry(c, &s->se_conns, cn_persession) {
1101                         if (c->cn_flags & NFS4_CDFC4_BACK)
1102                                 return c;
1103                 }
1104         }
1105         return NULL;
1106 }
1107
1108 static void nfsd4_process_cb_update(struct nfsd4_callback *cb)
1109 {
1110         struct nfs4_cb_conn conn;
1111         struct nfs4_client *clp = cb->cb_clp;
1112         struct nfsd4_session *ses = NULL;
1113         struct nfsd4_conn *c;
1114         int err;
1115
1116         /*
1117          * This is either an update, or the client dying; in either case,
1118          * kill the old client:
1119          */
1120         if (clp->cl_cb_client) {
1121                 rpc_shutdown_client(clp->cl_cb_client);
1122                 clp->cl_cb_client = NULL;
1123                 put_rpccred(clp->cl_cb_cred);
1124                 clp->cl_cb_cred = NULL;
1125         }
1126         if (clp->cl_cb_conn.cb_xprt) {
1127                 svc_xprt_put(clp->cl_cb_conn.cb_xprt);
1128                 clp->cl_cb_conn.cb_xprt = NULL;
1129         }
1130         if (test_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags))
1131                 return;
1132         spin_lock(&clp->cl_lock);
1133         /*
1134          * Only serialized callback code is allowed to clear these
1135          * flags; main nfsd code can only set them:
1136          */
1137         BUG_ON(!(clp->cl_flags & NFSD4_CLIENT_CB_FLAG_MASK));
1138         clear_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags);
1139         memcpy(&conn, &cb->cb_clp->cl_cb_conn, sizeof(struct nfs4_cb_conn));
1140         c = __nfsd4_find_backchannel(clp);
1141         if (c) {
1142                 svc_xprt_get(c->cn_xprt);
1143                 conn.cb_xprt = c->cn_xprt;
1144                 ses = c->cn_session;
1145         }
1146         spin_unlock(&clp->cl_lock);
1147
1148         err = setup_callback_client(clp, &conn, ses);
1149         if (err) {
1150                 nfsd4_mark_cb_down(clp, err);
1151                 return;
1152         }
1153 }
1154
1155 static void
1156 nfsd4_run_cb_work(struct work_struct *work)
1157 {
1158         struct nfsd4_callback *cb =
1159                 container_of(work, struct nfsd4_callback, cb_work);
1160         struct nfs4_client *clp = cb->cb_clp;
1161         struct rpc_clnt *clnt;
1162
1163         if (cb->cb_need_restart) {
1164                 cb->cb_need_restart = false;
1165         } else {
1166                 if (cb->cb_ops && cb->cb_ops->prepare)
1167                         cb->cb_ops->prepare(cb);
1168         }
1169
1170         if (clp->cl_flags & NFSD4_CLIENT_CB_FLAG_MASK)
1171                 nfsd4_process_cb_update(cb);
1172
1173         clnt = clp->cl_cb_client;
1174         if (!clnt) {
1175                 /* Callback channel broken, or client killed; give up: */
1176                 if (cb->cb_ops && cb->cb_ops->release)
1177                         cb->cb_ops->release(cb);
1178                 return;
1179         }
1180
1181         /*
1182          * Don't send probe messages for 4.1 or later.
1183          */
1184         if (!cb->cb_ops && clp->cl_minorversion) {
1185                 clp->cl_cb_state = NFSD4_CB_UP;
1186                 return;
1187         }
1188
1189         cb->cb_msg.rpc_cred = clp->cl_cb_cred;
1190         rpc_call_async(clnt, &cb->cb_msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN,
1191                         cb->cb_ops ? &nfsd4_cb_ops : &nfsd4_cb_probe_ops, cb);
1192 }
1193
1194 void nfsd4_init_cb(struct nfsd4_callback *cb, struct nfs4_client *clp,
1195                 const struct nfsd4_callback_ops *ops, enum nfsd4_cb_op op)
1196 {
1197         cb->cb_clp = clp;
1198         cb->cb_msg.rpc_proc = &nfs4_cb_procedures[op];
1199         cb->cb_msg.rpc_argp = cb;
1200         cb->cb_msg.rpc_resp = cb;
1201         cb->cb_ops = ops;
1202         INIT_WORK(&cb->cb_work, nfsd4_run_cb_work);
1203         cb->cb_seq_status = 1;
1204         cb->cb_status = 0;
1205         cb->cb_need_restart = false;
1206 }
1207
1208 void nfsd4_run_cb(struct nfsd4_callback *cb)
1209 {
1210         queue_work(callback_wq, &cb->cb_work);
1211 }