[ARM] S3C maintainer updates merge branch maintainers-updates into s3c-fixes
[linux-2.6] / fs / nfsd / nfs4callback.c
1 /*
2  *  linux/fs/nfsd/nfs4callback.c
3  *
4  *  Copyright (c) 2001 The Regents of the University of Michigan.
5  *  All rights reserved.
6  *
7  *  Kendrick Smith <kmsmith@umich.edu>
8  *  Andy Adamson <andros@umich.edu>
9  *
10  *  Redistribution and use in source and binary forms, with or without
11  *  modification, are permitted provided that the following conditions
12  *  are met:
13  *
14  *  1. Redistributions of source code must retain the above copyright
15  *     notice, this list of conditions and the following disclaimer.
16  *  2. Redistributions in binary form must reproduce the above copyright
17  *     notice, this list of conditions and the following disclaimer in the
18  *     documentation and/or other materials provided with the distribution.
19  *  3. Neither the name of the University nor the names of its
20  *     contributors may be used to endorse or promote products derived
21  *     from this software without specific prior written permission.
22  *
23  *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
24  *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
25  *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
26  *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
28  *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
29  *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
30  *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
31  *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
32  *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
33  *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34  */
35
36 #include <linux/module.h>
37 #include <linux/list.h>
38 #include <linux/inet.h>
39 #include <linux/errno.h>
40 #include <linux/delay.h>
41 #include <linux/sched.h>
42 #include <linux/kthread.h>
43 #include <linux/sunrpc/xdr.h>
44 #include <linux/sunrpc/svc.h>
45 #include <linux/sunrpc/clnt.h>
46 #include <linux/nfsd/nfsd.h>
47 #include <linux/nfsd/state.h>
48 #include <linux/sunrpc/sched.h>
49 #include <linux/nfs4.h>
50
51 #define NFSDDBG_FACILITY                NFSDDBG_PROC
52
53 #define NFSPROC4_CB_NULL 0
54 #define NFSPROC4_CB_COMPOUND 1
55
56 /* Index of predefined Linux callback client operations */
57
58 enum {
59         NFSPROC4_CLNT_CB_NULL = 0,
60         NFSPROC4_CLNT_CB_RECALL,
61 };
62
63 enum nfs_cb_opnum4 {
64         OP_CB_RECALL            = 4,
65 };
66
67 #define NFS4_MAXTAGLEN          20
68
69 #define NFS4_enc_cb_null_sz             0
70 #define NFS4_dec_cb_null_sz             0
71 #define cb_compound_enc_hdr_sz          4
72 #define cb_compound_dec_hdr_sz          (3 + (NFS4_MAXTAGLEN >> 2))
73 #define op_enc_sz                       1
74 #define op_dec_sz                       2
75 #define enc_nfs4_fh_sz                  (1 + (NFS4_FHSIZE >> 2))
76 #define enc_stateid_sz                  (NFS4_STATEID_SIZE >> 2)
77 #define NFS4_enc_cb_recall_sz           (cb_compound_enc_hdr_sz +       \
78                                         1 + enc_stateid_sz +            \
79                                         enc_nfs4_fh_sz)
80
81 #define NFS4_dec_cb_recall_sz           (cb_compound_dec_hdr_sz  +      \
82                                         op_dec_sz)
83
84 /*
85 * Generic encode routines from fs/nfs/nfs4xdr.c
86 */
87 static inline __be32 *
88 xdr_writemem(__be32 *p, const void *ptr, int nbytes)
89 {
90         int tmp = XDR_QUADLEN(nbytes);
91         if (!tmp)
92                 return p;
93         p[tmp-1] = 0;
94         memcpy(p, ptr, nbytes);
95         return p + tmp;
96 }
97
98 #define WRITE32(n)               *p++ = htonl(n)
99 #define WRITEMEM(ptr,nbytes)     do {                           \
100         p = xdr_writemem(p, ptr, nbytes);                       \
101 } while (0)
102 #define RESERVE_SPACE(nbytes)   do {                            \
103         p = xdr_reserve_space(xdr, nbytes);                     \
104         if (!p) dprintk("NFSD: RESERVE_SPACE(%d) failed in function %s\n", (int) (nbytes), __func__); \
105         BUG_ON(!p);                                             \
106 } while (0)
107
108 /*
109  * Generic decode routines from fs/nfs/nfs4xdr.c
110  */
111 #define DECODE_TAIL                             \
112         status = 0;                             \
113 out:                                            \
114         return status;                          \
115 xdr_error:                                      \
116         dprintk("NFSD: xdr error! (%s:%d)\n", __FILE__, __LINE__); \
117         status = -EIO;                          \
118         goto out
119
120 #define READ32(x)         (x) = ntohl(*p++)
121 #define READ64(x)         do {                  \
122         (x) = (u64)ntohl(*p++) << 32;           \
123         (x) |= ntohl(*p++);                     \
124 } while (0)
125 #define READTIME(x)       do {                  \
126         p++;                                    \
127         (x.tv_sec) = ntohl(*p++);               \
128         (x.tv_nsec) = ntohl(*p++);              \
129 } while (0)
130 #define READ_BUF(nbytes)  do { \
131         p = xdr_inline_decode(xdr, nbytes); \
132         if (!p) { \
133                 dprintk("NFSD: %s: reply buffer overflowed in line %d.\n", \
134                         __func__, __LINE__); \
135                 return -EIO; \
136         } \
137 } while (0)
138
139 struct nfs4_cb_compound_hdr {
140         int             status;
141         u32             ident;
142         u32             nops;
143         __be32          *nops_p;
144         u32             minorversion;
145         u32             taglen;
146         char            *tag;
147 };
148
149 static struct {
150 int stat;
151 int errno;
152 } nfs_cb_errtbl[] = {
153         { NFS4_OK,              0               },
154         { NFS4ERR_PERM,         EPERM           },
155         { NFS4ERR_NOENT,        ENOENT          },
156         { NFS4ERR_IO,           EIO             },
157         { NFS4ERR_NXIO,         ENXIO           },
158         { NFS4ERR_ACCESS,       EACCES          },
159         { NFS4ERR_EXIST,        EEXIST          },
160         { NFS4ERR_XDEV,         EXDEV           },
161         { NFS4ERR_NOTDIR,       ENOTDIR         },
162         { NFS4ERR_ISDIR,        EISDIR          },
163         { NFS4ERR_INVAL,        EINVAL          },
164         { NFS4ERR_FBIG,         EFBIG           },
165         { NFS4ERR_NOSPC,        ENOSPC          },
166         { NFS4ERR_ROFS,         EROFS           },
167         { NFS4ERR_MLINK,        EMLINK          },
168         { NFS4ERR_NAMETOOLONG,  ENAMETOOLONG    },
169         { NFS4ERR_NOTEMPTY,     ENOTEMPTY       },
170         { NFS4ERR_DQUOT,        EDQUOT          },
171         { NFS4ERR_STALE,        ESTALE          },
172         { NFS4ERR_BADHANDLE,    EBADHANDLE      },
173         { NFS4ERR_BAD_COOKIE,   EBADCOOKIE      },
174         { NFS4ERR_NOTSUPP,      ENOTSUPP        },
175         { NFS4ERR_TOOSMALL,     ETOOSMALL       },
176         { NFS4ERR_SERVERFAULT,  ESERVERFAULT    },
177         { NFS4ERR_BADTYPE,      EBADTYPE        },
178         { NFS4ERR_LOCKED,       EAGAIN          },
179         { NFS4ERR_RESOURCE,     EREMOTEIO       },
180         { NFS4ERR_SYMLINK,      ELOOP           },
181         { NFS4ERR_OP_ILLEGAL,   EOPNOTSUPP      },
182         { NFS4ERR_DEADLOCK,     EDEADLK         },
183         { -1,                   EIO             }
184 };
185
186 static int
187 nfs_cb_stat_to_errno(int stat)
188 {
189         int i;
190         for (i = 0; nfs_cb_errtbl[i].stat != -1; i++) {
191                 if (nfs_cb_errtbl[i].stat == stat)
192                         return nfs_cb_errtbl[i].errno;
193         }
194         /* If we cannot translate the error, the recovery routines should
195         * handle it.
196         * Note: remaining NFSv4 error codes have values > 10000, so should
197         * not conflict with native Linux error codes.
198         */
199         return stat;
200 }
201
202 /*
203  * XDR encode
204  */
205
206 static void
207 encode_cb_compound_hdr(struct xdr_stream *xdr, struct nfs4_cb_compound_hdr *hdr)
208 {
209         __be32 * p;
210
211         RESERVE_SPACE(16);
212         WRITE32(0);            /* tag length is always 0 */
213         WRITE32(hdr->minorversion);
214         WRITE32(hdr->ident);
215         hdr->nops_p = p;
216         WRITE32(hdr->nops);
217 }
218
219 static void encode_cb_nops(struct nfs4_cb_compound_hdr *hdr)
220 {
221         *hdr->nops_p = htonl(hdr->nops);
222 }
223
224 static void
225 encode_cb_recall(struct xdr_stream *xdr, struct nfs4_delegation *dp,
226                 struct nfs4_cb_compound_hdr *hdr)
227 {
228         __be32 *p;
229         int len = dp->dl_fh.fh_size;
230
231         RESERVE_SPACE(12+sizeof(dp->dl_stateid) + len);
232         WRITE32(OP_CB_RECALL);
233         WRITE32(dp->dl_stateid.si_generation);
234         WRITEMEM(&dp->dl_stateid.si_opaque, sizeof(stateid_opaque_t));
235         WRITE32(0); /* truncate optimization not implemented */
236         WRITE32(len);
237         WRITEMEM(&dp->dl_fh.fh_base, len);
238         hdr->nops++;
239 }
240
241 static int
242 nfs4_xdr_enc_cb_null(struct rpc_rqst *req, __be32 *p)
243 {
244         struct xdr_stream xdrs, *xdr = &xdrs;
245
246         xdr_init_encode(&xdrs, &req->rq_snd_buf, p);
247         RESERVE_SPACE(0);
248         return 0;
249 }
250
251 static int
252 nfs4_xdr_enc_cb_recall(struct rpc_rqst *req, __be32 *p, struct nfs4_delegation *args)
253 {
254         struct xdr_stream xdr;
255         struct nfs4_cb_compound_hdr hdr = {
256                 .ident = args->dl_ident,
257         };
258
259         xdr_init_encode(&xdr, &req->rq_snd_buf, p);
260         encode_cb_compound_hdr(&xdr, &hdr);
261         encode_cb_recall(&xdr, args, &hdr);
262         encode_cb_nops(&hdr);
263         return 0;
264 }
265
266
267 static int
268 decode_cb_compound_hdr(struct xdr_stream *xdr, struct nfs4_cb_compound_hdr *hdr){
269         __be32 *p;
270
271         READ_BUF(8);
272         READ32(hdr->status);
273         READ32(hdr->taglen);
274         READ_BUF(hdr->taglen + 4);
275         hdr->tag = (char *)p;
276         p += XDR_QUADLEN(hdr->taglen);
277         READ32(hdr->nops);
278         return 0;
279 }
280
281 static int
282 decode_cb_op_hdr(struct xdr_stream *xdr, enum nfs_opnum4 expected)
283 {
284         __be32 *p;
285         u32 op;
286         int32_t nfserr;
287
288         READ_BUF(8);
289         READ32(op);
290         if (op != expected) {
291                 dprintk("NFSD: decode_cb_op_hdr: Callback server returned "
292                          " operation %d but we issued a request for %d\n",
293                          op, expected);
294                 return -EIO;
295         }
296         READ32(nfserr);
297         if (nfserr != NFS_OK)
298                 return -nfs_cb_stat_to_errno(nfserr);
299         return 0;
300 }
301
302 static int
303 nfs4_xdr_dec_cb_null(struct rpc_rqst *req, __be32 *p)
304 {
305         return 0;
306 }
307
308 static int
309 nfs4_xdr_dec_cb_recall(struct rpc_rqst *rqstp, __be32 *p)
310 {
311         struct xdr_stream xdr;
312         struct nfs4_cb_compound_hdr hdr;
313         int status;
314
315         xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, p);
316         status = decode_cb_compound_hdr(&xdr, &hdr);
317         if (status)
318                 goto out;
319         status = decode_cb_op_hdr(&xdr, OP_CB_RECALL);
320 out:
321         return status;
322 }
323
324 /*
325  * RPC procedure tables
326  */
327 #define PROC(proc, call, argtype, restype)                              \
328 [NFSPROC4_CLNT_##proc] = {                                              \
329         .p_proc   = NFSPROC4_CB_##call,                                 \
330         .p_encode = (kxdrproc_t) nfs4_xdr_##argtype,                    \
331         .p_decode = (kxdrproc_t) nfs4_xdr_##restype,                    \
332         .p_arglen = NFS4_##argtype##_sz,                                \
333         .p_replen = NFS4_##restype##_sz,                                \
334         .p_statidx = NFSPROC4_CB_##call,                                \
335         .p_name   = #proc,                                              \
336 }
337
338 static struct rpc_procinfo     nfs4_cb_procedures[] = {
339     PROC(CB_NULL,      NULL,     enc_cb_null,     dec_cb_null),
340     PROC(CB_RECALL,    COMPOUND,   enc_cb_recall,      dec_cb_recall),
341 };
342
343 static struct rpc_version       nfs_cb_version4 = {
344         .number                 = 1,
345         .nrprocs                = ARRAY_SIZE(nfs4_cb_procedures),
346         .procs                  = nfs4_cb_procedures
347 };
348
349 static struct rpc_version *     nfs_cb_version[] = {
350         NULL,
351         &nfs_cb_version4,
352 };
353
354 static struct rpc_program cb_program;
355
356 static struct rpc_stat cb_stats = {
357                 .program        = &cb_program
358 };
359
360 #define NFS4_CALLBACK 0x40000000
361 static struct rpc_program cb_program = {
362                 .name           = "nfs4_cb",
363                 .number         = NFS4_CALLBACK,
364                 .nrvers         = ARRAY_SIZE(nfs_cb_version),
365                 .version        = nfs_cb_version,
366                 .stats          = &cb_stats,
367                 .pipe_dir_name  = "/nfsd4_cb",
368 };
369
370 static int max_cb_time(void)
371 {
372         return max(NFSD_LEASE_TIME/10, (time_t)1) * HZ;
373 }
374
375 /* Reference counting, callback cleanup, etc., all look racy as heck.
376  * And why is cb_set an atomic? */
377
378 int setup_callback_client(struct nfs4_client *clp)
379 {
380         struct sockaddr_in      addr;
381         struct nfs4_cb_conn *cb = &clp->cl_cb_conn;
382         struct rpc_timeout      timeparms = {
383                 .to_initval     = max_cb_time(),
384                 .to_retries     = 0,
385         };
386         struct rpc_create_args args = {
387                 .protocol       = IPPROTO_TCP,
388                 .address        = (struct sockaddr *)&addr,
389                 .addrsize       = sizeof(addr),
390                 .timeout        = &timeparms,
391                 .program        = &cb_program,
392                 .prognumber     = cb->cb_prog,
393                 .version        = nfs_cb_version[1]->number,
394                 .authflavor     = clp->cl_flavor,
395                 .flags          = (RPC_CLNT_CREATE_NOPING | RPC_CLNT_CREATE_QUIET),
396                 .client_name    = clp->cl_principal,
397         };
398         struct rpc_clnt *client;
399
400         if (!clp->cl_principal && (clp->cl_flavor >= RPC_AUTH_GSS_KRB5))
401                 return -EINVAL;
402
403         /* Initialize address */
404         memset(&addr, 0, sizeof(addr));
405         addr.sin_family = AF_INET;
406         addr.sin_port = htons(cb->cb_port);
407         addr.sin_addr.s_addr = htonl(cb->cb_addr);
408
409         /* Create RPC client */
410         client = rpc_create(&args);
411         if (IS_ERR(client)) {
412                 dprintk("NFSD: couldn't create callback client: %ld\n",
413                         PTR_ERR(client));
414                 return PTR_ERR(client);
415         }
416         cb->cb_client = client;
417         return 0;
418
419 }
420
421 static void warn_no_callback_path(struct nfs4_client *clp, int reason)
422 {
423         dprintk("NFSD: warning: no callback path to client %.*s: error %d\n",
424                 (int)clp->cl_name.len, clp->cl_name.data, reason);
425 }
426
427 static void nfsd4_cb_probe_done(struct rpc_task *task, void *calldata)
428 {
429         struct nfs4_client *clp = calldata;
430
431         if (task->tk_status)
432                 warn_no_callback_path(clp, task->tk_status);
433         else
434                 atomic_set(&clp->cl_cb_conn.cb_set, 1);
435         put_nfs4_client(clp);
436 }
437
438 static const struct rpc_call_ops nfsd4_cb_probe_ops = {
439         .rpc_call_done = nfsd4_cb_probe_done,
440 };
441
442 static struct rpc_cred *lookup_cb_cred(struct nfs4_cb_conn *cb)
443 {
444         struct auth_cred acred = {
445                 .machine_cred = 1
446         };
447
448         /*
449          * Note in the gss case this doesn't actually have to wait for a
450          * gss upcall (or any calls to the client); this just creates a
451          * non-uptodate cred which the rpc state machine will fill in with
452          * a refresh_upcall later.
453          */
454         return rpcauth_lookup_credcache(cb->cb_client->cl_auth, &acred,
455                                                         RPCAUTH_LOOKUP_NEW);
456 }
457
458 void do_probe_callback(struct nfs4_client *clp)
459 {
460         struct nfs4_cb_conn *cb = &clp->cl_cb_conn;
461         struct rpc_message msg = {
462                 .rpc_proc       = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_NULL],
463                 .rpc_argp       = clp,
464         };
465         struct rpc_cred *cred;
466         int status;
467
468         cred = lookup_cb_cred(cb);
469         if (IS_ERR(cred)) {
470                 status = PTR_ERR(cred);
471                 goto out;
472         }
473         cb->cb_cred = cred;
474         msg.rpc_cred = cb->cb_cred;
475         status = rpc_call_async(cb->cb_client, &msg, RPC_TASK_SOFT,
476                                 &nfsd4_cb_probe_ops, (void *)clp);
477 out:
478         if (status) {
479                 warn_no_callback_path(clp, status);
480                 put_nfs4_client(clp);
481         }
482 }
483
484 /*
485  * Set up the callback client and put a NFSPROC4_CB_NULL on the wire...
486  */
487 void
488 nfsd4_probe_callback(struct nfs4_client *clp)
489 {
490         int status;
491
492         BUG_ON(atomic_read(&clp->cl_cb_conn.cb_set));
493
494         status = setup_callback_client(clp);
495         if (status) {
496                 warn_no_callback_path(clp, status);
497                 return;
498         }
499
500         /* the task holds a reference to the nfs4_client struct */
501         atomic_inc(&clp->cl_count);
502
503         do_probe_callback(clp);
504 }
505
506 static void nfsd4_cb_recall_done(struct rpc_task *task, void *calldata)
507 {
508         struct nfs4_delegation *dp = calldata;
509         struct nfs4_client *clp = dp->dl_client;
510
511         switch (task->tk_status) {
512         case -EIO:
513                 /* Network partition? */
514                 atomic_set(&clp->cl_cb_conn.cb_set, 0);
515                 warn_no_callback_path(clp, task->tk_status);
516         case -EBADHANDLE:
517         case -NFS4ERR_BAD_STATEID:
518                 /* Race: client probably got cb_recall
519                  * before open reply granting delegation */
520                 break;
521         default:
522                 /* success, or error we can't handle */
523                 return;
524         }
525         if (dp->dl_retries--) {
526                 rpc_delay(task, 2*HZ);
527                 task->tk_status = 0;
528                 rpc_restart_call(task);
529         } else {
530                 atomic_set(&clp->cl_cb_conn.cb_set, 0);
531                 warn_no_callback_path(clp, task->tk_status);
532         }
533 }
534
535 static void nfsd4_cb_recall_release(void *calldata)
536 {
537         struct nfs4_delegation *dp = calldata;
538         struct nfs4_client *clp = dp->dl_client;
539
540         nfs4_put_delegation(dp);
541         put_nfs4_client(clp);
542 }
543
544 static const struct rpc_call_ops nfsd4_cb_recall_ops = {
545         .rpc_call_done = nfsd4_cb_recall_done,
546         .rpc_release = nfsd4_cb_recall_release,
547 };
548
549 /*
550  * called with dp->dl_count inc'ed.
551  */
552 void
553 nfsd4_cb_recall(struct nfs4_delegation *dp)
554 {
555         struct nfs4_client *clp = dp->dl_client;
556         struct rpc_clnt *clnt = clp->cl_cb_conn.cb_client;
557         struct rpc_message msg = {
558                 .rpc_proc = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_RECALL],
559                 .rpc_argp = dp,
560                 .rpc_cred = clp->cl_cb_conn.cb_cred
561         };
562         int status;
563
564         dp->dl_retries = 1;
565         status = rpc_call_async(clnt, &msg, RPC_TASK_SOFT,
566                                 &nfsd4_cb_recall_ops, dp);
567         if (status) {
568                 put_nfs4_client(clp);
569                 nfs4_put_delegation(dp);
570         }
571 }