Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6
[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/sunrpc/xdr.h>
43 #include <linux/sunrpc/svc.h>
44 #include <linux/sunrpc/clnt.h>
45 #include <linux/nfsd/nfsd.h>
46 #include <linux/nfsd/state.h>
47 #include <linux/sunrpc/sched.h>
48 #include <linux/nfs4.h>
49
50 #define NFSDDBG_FACILITY                NFSDDBG_PROC
51
52 #define NFSPROC4_CB_NULL 0
53 #define NFSPROC4_CB_COMPOUND 1
54
55 /* declarations */
56 static const struct rpc_call_ops nfs4_cb_null_ops;
57
58 /* Index of predefined Linux callback client operations */
59
60 enum {
61         NFSPROC4_CLNT_CB_NULL = 0,
62         NFSPROC4_CLNT_CB_RECALL,
63 };
64
65 enum nfs_cb_opnum4 {
66         OP_CB_RECALL            = 4,
67 };
68
69 #define NFS4_MAXTAGLEN          20
70
71 #define NFS4_enc_cb_null_sz             0
72 #define NFS4_dec_cb_null_sz             0
73 #define cb_compound_enc_hdr_sz          4
74 #define cb_compound_dec_hdr_sz          (3 + (NFS4_MAXTAGLEN >> 2))
75 #define op_enc_sz                       1
76 #define op_dec_sz                       2
77 #define enc_nfs4_fh_sz                  (1 + (NFS4_FHSIZE >> 2))
78 #define enc_stateid_sz                  16
79 #define NFS4_enc_cb_recall_sz           (cb_compound_enc_hdr_sz +       \
80                                         1 + enc_stateid_sz +            \
81                                         enc_nfs4_fh_sz)
82
83 #define NFS4_dec_cb_recall_sz           (cb_compound_dec_hdr_sz  +      \
84                                         op_dec_sz)
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), __FUNCTION__); \
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                         __FUNCTION__, __LINE__); \
137                 return -EIO; \
138         } \
139 } while (0)
140
141 struct nfs4_cb_compound_hdr {
142         int             status;
143         u32             ident;
144         u32             nops;
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 int
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(NFS4_MINOR_VERSION);
214         WRITE32(hdr->ident);
215         WRITE32(hdr->nops);
216         return 0;
217 }
218
219 static int
220 encode_cb_recall(struct xdr_stream *xdr, struct nfs4_cb_recall *cb_rec)
221 {
222         __be32 *p;
223         int len = cb_rec->cbr_fhlen;
224
225         RESERVE_SPACE(12+sizeof(cb_rec->cbr_stateid) + len);
226         WRITE32(OP_CB_RECALL);
227         WRITEMEM(&cb_rec->cbr_stateid, sizeof(stateid_t));
228         WRITE32(cb_rec->cbr_trunc);
229         WRITE32(len);
230         WRITEMEM(cb_rec->cbr_fhval, len);
231         return 0;
232 }
233
234 static int
235 nfs4_xdr_enc_cb_null(struct rpc_rqst *req, __be32 *p)
236 {
237         struct xdr_stream xdrs, *xdr = &xdrs;
238
239         xdr_init_encode(&xdrs, &req->rq_snd_buf, p);
240         RESERVE_SPACE(0);
241         return 0;
242 }
243
244 static int
245 nfs4_xdr_enc_cb_recall(struct rpc_rqst *req, __be32 *p, struct nfs4_cb_recall *args)
246 {
247         struct xdr_stream xdr;
248         struct nfs4_cb_compound_hdr hdr = {
249                 .ident = args->cbr_ident,
250                 .nops   = 1,
251         };
252
253         xdr_init_encode(&xdr, &req->rq_snd_buf, p);
254         encode_cb_compound_hdr(&xdr, &hdr);
255         return (encode_cb_recall(&xdr, args));
256 }
257
258
259 static int
260 decode_cb_compound_hdr(struct xdr_stream *xdr, struct nfs4_cb_compound_hdr *hdr){
261         __be32 *p;
262
263         READ_BUF(8);
264         READ32(hdr->status);
265         READ32(hdr->taglen);
266         READ_BUF(hdr->taglen + 4);
267         hdr->tag = (char *)p;
268         p += XDR_QUADLEN(hdr->taglen);
269         READ32(hdr->nops);
270         return 0;
271 }
272
273 static int
274 decode_cb_op_hdr(struct xdr_stream *xdr, enum nfs_opnum4 expected)
275 {
276         __be32 *p;
277         u32 op;
278         int32_t nfserr;
279
280         READ_BUF(8);
281         READ32(op);
282         if (op != expected) {
283                 dprintk("NFSD: decode_cb_op_hdr: Callback server returned "
284                          " operation %d but we issued a request for %d\n",
285                          op, expected);
286                 return -EIO;
287         }
288         READ32(nfserr);
289         if (nfserr != NFS_OK)
290                 return -nfs_cb_stat_to_errno(nfserr);
291         return 0;
292 }
293
294 static int
295 nfs4_xdr_dec_cb_null(struct rpc_rqst *req, __be32 *p)
296 {
297         return 0;
298 }
299
300 static int
301 nfs4_xdr_dec_cb_recall(struct rpc_rqst *rqstp, __be32 *p)
302 {
303         struct xdr_stream xdr;
304         struct nfs4_cb_compound_hdr hdr;
305         int status;
306
307         xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, p);
308         status = decode_cb_compound_hdr(&xdr, &hdr);
309         if (status)
310                 goto out;
311         status = decode_cb_op_hdr(&xdr, OP_CB_RECALL);
312 out:
313         return status;
314 }
315
316 /*
317  * RPC procedure tables
318  */
319 #define PROC(proc, call, argtype, restype)                              \
320 [NFSPROC4_CLNT_##proc] = {                                              \
321         .p_proc   = NFSPROC4_CB_##call,                                 \
322         .p_encode = (kxdrproc_t) nfs4_xdr_##argtype,                    \
323         .p_decode = (kxdrproc_t) nfs4_xdr_##restype,                    \
324         .p_arglen = NFS4_##argtype##_sz,                                \
325         .p_replen = NFS4_##restype##_sz,                                \
326         .p_statidx = NFSPROC4_CB_##call,                                \
327         .p_name   = #proc,                                              \
328 }
329
330 static struct rpc_procinfo     nfs4_cb_procedures[] = {
331     PROC(CB_NULL,      NULL,     enc_cb_null,     dec_cb_null),
332     PROC(CB_RECALL,    COMPOUND,   enc_cb_recall,      dec_cb_recall),
333 };
334
335 static struct rpc_version       nfs_cb_version4 = {
336         .number                 = 1,
337         .nrprocs                = ARRAY_SIZE(nfs4_cb_procedures),
338         .procs                  = nfs4_cb_procedures
339 };
340
341 static struct rpc_version *     nfs_cb_version[] = {
342         NULL,
343         &nfs_cb_version4,
344 };
345
346 /*
347  * Use the SETCLIENTID credential
348  */
349 static struct rpc_cred *
350 nfsd4_lookupcred(struct nfs4_client *clp, int taskflags)
351 {
352         struct auth_cred acred;
353         struct rpc_clnt *clnt = clp->cl_callback.cb_client;
354         struct rpc_cred *ret;
355
356         get_group_info(clp->cl_cred.cr_group_info);
357         acred.uid = clp->cl_cred.cr_uid;
358         acred.gid = clp->cl_cred.cr_gid;
359         acred.group_info = clp->cl_cred.cr_group_info;
360
361         dprintk("NFSD:     looking up %s cred\n",
362                 clnt->cl_auth->au_ops->au_name);
363         ret = rpcauth_lookup_credcache(clnt->cl_auth, &acred, taskflags);
364         put_group_info(clp->cl_cred.cr_group_info);
365         return ret;
366 }
367
368 /*
369  * Set up the callback client and put a NFSPROC4_CB_NULL on the wire...
370  */
371 void
372 nfsd4_probe_callback(struct nfs4_client *clp)
373 {
374         struct sockaddr_in      addr;
375         struct nfs4_callback    *cb = &clp->cl_callback;
376         struct rpc_timeout      timeparms = {
377                 .to_initval     = (NFSD_LEASE_TIME/4) * HZ,
378                 .to_retries     = 5,
379                 .to_maxval      = (NFSD_LEASE_TIME/2) * HZ,
380                 .to_exponential = 1,
381         };
382         struct rpc_program *    program = &cb->cb_program;
383         struct rpc_create_args args = {
384                 .protocol       = IPPROTO_TCP,
385                 .address        = (struct sockaddr *)&addr,
386                 .addrsize       = sizeof(addr),
387                 .timeout        = &timeparms,
388                 .program        = program,
389                 .version        = nfs_cb_version[1]->number,
390                 .authflavor     = RPC_AUTH_UNIX,        /* XXX: need AUTH_GSS... */
391                 .flags          = (RPC_CLNT_CREATE_NOPING),
392         };
393         struct rpc_message msg = {
394                 .rpc_proc       = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_NULL],
395                 .rpc_argp       = clp,
396         };
397         char clientname[16];
398         int status;
399
400         if (atomic_read(&cb->cb_set))
401                 return;
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         /* Initialize rpc_program */
410         program->name = "nfs4_cb";
411         program->number = cb->cb_prog;
412         program->nrvers = ARRAY_SIZE(nfs_cb_version);
413         program->version = nfs_cb_version;
414         program->stats = &cb->cb_stat;
415
416         /* Initialize rpc_stat */
417         memset(program->stats, 0, sizeof(cb->cb_stat));
418         program->stats->program = program;
419
420         /* Just here to make some printk's more useful: */
421         snprintf(clientname, sizeof(clientname),
422                 "%u.%u.%u.%u", NIPQUAD(addr.sin_addr));
423         args.servername = clientname;
424
425         /* Create RPC client */
426         cb->cb_client = rpc_create(&args);
427         if (IS_ERR(cb->cb_client)) {
428                 dprintk("NFSD: couldn't create callback client\n");
429                 goto out_err;
430         }
431
432         /* Kick rpciod, put the call on the wire. */
433         if (rpciod_up() != 0)
434                 goto out_clnt;
435
436         /* the task holds a reference to the nfs4_client struct */
437         atomic_inc(&clp->cl_count);
438
439         msg.rpc_cred = nfsd4_lookupcred(clp,0);
440         if (IS_ERR(msg.rpc_cred))
441                 goto out_rpciod;
442         status = rpc_call_async(cb->cb_client, &msg, RPC_TASK_ASYNC, &nfs4_cb_null_ops, NULL);
443         put_rpccred(msg.rpc_cred);
444
445         if (status != 0) {
446                 dprintk("NFSD: asynchronous NFSPROC4_CB_NULL failed!\n");
447                 goto out_rpciod;
448         }
449         return;
450
451 out_rpciod:
452         atomic_dec(&clp->cl_count);
453         rpciod_down();
454 out_clnt:
455         rpc_shutdown_client(cb->cb_client);
456 out_err:
457         cb->cb_client = NULL;
458         dprintk("NFSD: warning: no callback path to client %.*s\n",
459                 (int)clp->cl_name.len, clp->cl_name.data);
460 }
461
462 static void
463 nfs4_cb_null(struct rpc_task *task, void *dummy)
464 {
465         struct nfs4_client *clp = (struct nfs4_client *)task->tk_msg.rpc_argp;
466         struct nfs4_callback *cb = &clp->cl_callback;
467         __be32 addr = htonl(cb->cb_addr);
468
469         dprintk("NFSD: nfs4_cb_null task->tk_status %d\n", task->tk_status);
470
471         if (task->tk_status < 0) {
472                 dprintk("NFSD: callback establishment to client %.*s failed\n",
473                         (int)clp->cl_name.len, clp->cl_name.data);
474                 goto out;
475         }
476         atomic_set(&cb->cb_set, 1);
477         dprintk("NFSD: callback set to client %u.%u.%u.%u\n", NIPQUAD(addr));
478 out:
479         put_nfs4_client(clp);
480 }
481
482 static const struct rpc_call_ops nfs4_cb_null_ops = {
483         .rpc_call_done = nfs4_cb_null,
484 };
485
486 /*
487  * called with dp->dl_count inc'ed.
488  * nfs4_lock_state() may or may not have been called.
489  */
490 void
491 nfsd4_cb_recall(struct nfs4_delegation *dp)
492 {
493         struct nfs4_client *clp = dp->dl_client;
494         struct rpc_clnt *clnt = clp->cl_callback.cb_client;
495         struct nfs4_cb_recall *cbr = &dp->dl_recall;
496         struct rpc_message msg = {
497                 .rpc_proc = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_RECALL],
498                 .rpc_argp = cbr,
499         };
500         int retries = 1;
501         int status = 0;
502
503         if ((!atomic_read(&clp->cl_callback.cb_set)) || !clnt)
504                 return;
505
506         msg.rpc_cred = nfsd4_lookupcred(clp, 0);
507         if (IS_ERR(msg.rpc_cred))
508                 goto out;
509
510         cbr->cbr_trunc = 0; /* XXX need to implement truncate optimization */
511         cbr->cbr_dp = dp;
512
513         status = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT);
514         while (retries--) {
515                 switch (status) {
516                         case -EIO:
517                                 /* Network partition? */
518                         case -EBADHANDLE:
519                         case -NFS4ERR_BAD_STATEID:
520                                 /* Race: client probably got cb_recall
521                                  * before open reply granting delegation */
522                                 break;
523                         default:
524                                 goto out_put_cred;
525                 }
526                 ssleep(2);
527                 status = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT);
528         }
529 out_put_cred:
530         put_rpccred(msg.rpc_cred);
531 out:
532         if (status == -EIO)
533                 atomic_set(&clp->cl_callback.cb_set, 0);
534         /* Success or failure, now we're either waiting for lease expiration
535          * or deleg_return. */
536         dprintk("NFSD: nfs4_cb_recall: dp %p dl_flock %p dl_count %d\n",dp, dp->dl_flock, atomic_read(&dp->dl_count));
537         nfs4_put_delegation(dp);
538         return;
539 }