summaryrefslogtreecommitdiffstats
path: root/fs/nfsd/nfs4callback.c
blob: 6eb5cd2381ab6fbb3f71f086381203c01634b9b4 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
/*
 *  linux/fs/nfsd/nfs4callback.c
 *
 *  Copyright (c) 2001 The Regents of the University of Michigan.
 *  All rights reserved.
 *
 *  Kendrick Smith <kmsmith@umich.edu>
 *  Andy Adamson <andros@umich.edu>
 *
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted provided that the following conditions
 *  are met:
 *
 *  1. Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *  2. Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 *  3. Neither the name of the University nor the names of its
 *     contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
 *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
 *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <linux/module.h>
#include <linux/list.h>
#include <linux/inet.h>
#include <linux/errno.h>
#include <linux/delay.h>
#include <linux/sched.h>
#include <linux/kthread.h>
#include <linux/sunrpc/xdr.h>
#include <linux/sunrpc/svc.h>
#include <linux/sunrpc/clnt.h>
#include <linux/nfsd/nfsd.h>
#include <linux/nfsd/state.h>
#include <linux/sunrpc/sched.h>
#include <linux/nfs4.h>

#define NFSDDBG_FACILITY                NFSDDBG_PROC

#define NFSPROC4_CB_NULL 0
#define NFSPROC4_CB_COMPOUND 1

/* declarations */
static const struct rpc_call_ops nfs4_cb_null_ops;

/* Index of predefined Linux callback client operations */

enum {
        NFSPROC4_CLNT_CB_NULL = 0,
	NFSPROC4_CLNT_CB_RECALL,
};

enum nfs_cb_opnum4 {
	OP_CB_RECALL            = 4,
};

#define NFS4_MAXTAGLEN		20

#define NFS4_enc_cb_null_sz		0
#define NFS4_dec_cb_null_sz		0
#define cb_compound_enc_hdr_sz		4
#define cb_compound_dec_hdr_sz		(3 + (NFS4_MAXTAGLEN >> 2))
#define op_enc_sz			1
#define op_dec_sz			2
#define enc_nfs4_fh_sz			(1 + (NFS4_FHSIZE >> 2))
#define enc_stateid_sz			(NFS4_STATEID_SIZE >> 2)
#define NFS4_enc_cb_recall_sz		(cb_compound_enc_hdr_sz +       \
					1 + enc_stateid_sz +            \
					enc_nfs4_fh_sz)

#define NFS4_dec_cb_recall_sz		(cb_compound_dec_hdr_sz  +      \
					op_dec_sz)

/*
* Generic encode routines from fs/nfs/nfs4xdr.c
*/
static inline __be32 *
xdr_writemem(__be32 *p, const void *ptr, int nbytes)
{
	int tmp = XDR_QUADLEN(nbytes);
	if (!tmp)
		return p;
	p[tmp-1] = 0;
	memcpy(p, ptr, nbytes);
	return p + tmp;
}

#define WRITE32(n)               *p++ = htonl(n)
#define WRITEMEM(ptr,nbytes)     do {                           \
	p = xdr_writemem(p, ptr, nbytes);                       \
} while (0)
#define RESERVE_SPACE(nbytes)   do {                            \
	p = xdr_reserve_space(xdr, nbytes);                     \
	if (!p) dprintk("NFSD: RESERVE_SPACE(%d) failed in function %s\n", (int) (nbytes), __FUNCTION__); \
	BUG_ON(!p);                                             \
} while (0)

/*
 * Generic decode routines from fs/nfs/nfs4xdr.c
 */
#define DECODE_TAIL                             \
	status = 0;                             \
out:                                            \
	return status;                          \
xdr_error:                                      \
	dprintk("NFSD: xdr error! (%s:%d)\n", __FILE__, __LINE__); \
	status = -EIO;                          \
	goto out

#define READ32(x)         (x) = ntohl(*p++)
#define READ64(x)         do {                  \
	(x) = (u64)ntohl(*p++) << 32;           \
	(x) |= ntohl(*p++);                     \
} while (0)
#define READTIME(x)       do {                  \
	p++;                                    \
	(x.tv_sec) = ntohl(*p++);               \
	(x.tv_nsec) = ntohl(*p++);              \
} while (0)
#define READ_BUF(nbytes)  do { \
	p = xdr_inline_decode(xdr, nbytes); \
	if (!p) { \
		dprintk("NFSD: %s: reply buffer overflowed in line %d.\n", \
			__FUNCTION__, __LINE__); \
		return -EIO; \
	} \
} while (0)

struct nfs4_cb_compound_hdr {
	int		status;
	u32		ident;
	u32		nops;
	u32		taglen;
	char *		tag;
};

static struct {
int stat;
int errno;
} nfs_cb_errtbl[] = {
	{ NFS4_OK,		0               },
	{ NFS4ERR_PERM,		EPERM           },
	{ NFS4ERR_NOENT,	ENOENT          },
	{ NFS4ERR_IO,		EIO             },
	{ NFS4ERR_NXIO,		ENXIO           },
	{ NFS4ERR_ACCESS,	EACCES          },
	{ NFS4ERR_EXIST,	EEXIST          },
	{ NFS4ERR_XDEV,		EXDEV           },
	{ NFS4ERR_NOTDIR,	ENOTDIR         },
	{ NFS4ERR_ISDIR,	EISDIR          },
	{ NFS4ERR_INVAL,	EINVAL          },
	{ NFS4ERR_FBIG,		EFBIG           },
	{ NFS4ERR_NOSPC,	ENOSPC          },
	{ NFS4ERR_ROFS,		EROFS           },
	{ NFS4ERR_MLINK,	EMLINK          },
	{ NFS4ERR_NAMETOOLONG,	ENAMETOOLONG    },
	{ NFS4ERR_NOTEMPTY,	ENOTEMPTY       },
	{ NFS4ERR_DQUOT,	EDQUOT          },
	{ NFS4ERR_STALE,	ESTALE          },
	{ NFS4ERR_BADHANDLE,	EBADHANDLE      },
	{ NFS4ERR_BAD_COOKIE,	EBADCOOKIE      },
	{ NFS4ERR_NOTSUPP,	ENOTSUPP        },
	{ NFS4ERR_TOOSMALL,	ETOOSMALL       },
	{ NFS4ERR_SERVERFAULT,	ESERVERFAULT    },
	{ NFS4ERR_BADTYPE,	EBADTYPE        },
	{ NFS4ERR_LOCKED,	EAGAIN          },
	{ NFS4ERR_RESOURCE,	EREMOTEIO       },
	{ NFS4ERR_SYMLINK,	ELOOP           },
	{ NFS4ERR_OP_ILLEGAL,	EOPNOTSUPP      },
	{ NFS4ERR_DEADLOCK,	EDEADLK         },
	{ -1,                   EIO             }
};

static int
nfs_cb_stat_to_errno(int stat)
{
	int i;
	for (i = 0; nfs_cb_errtbl[i].stat != -1; i++) {
		if (nfs_cb_errtbl[i].stat == stat)
			return nfs_cb_errtbl[i].errno;
	}
	/* If we cannot translate the error, the recovery routines should
	* handle it.
	* Note: remaining NFSv4 error codes have values > 10000, so should
	* not conflict with native Linux error codes.
	*/
	return stat;
}

/*
 * XDR encode
 */

static int
encode_cb_compound_hdr(struct xdr_stream *xdr, struct nfs4_cb_compound_hdr *hdr)
{
	__be32 * p;

	RESERVE_SPACE(16);
	WRITE32(0);            /* tag length is always 0 */
	WRITE32(NFS4_MINOR_VERSION);
	WRITE32(hdr->ident);
	WRITE32(hdr->nops);
	return 0;
}

static int
encode_cb_recall(struct xdr_stream *xdr, struct nfs4_cb_recall *cb_rec)
{
	__be32 *p;
	int len = cb_rec->cbr_fhlen;

	RESERVE_SPACE(12+sizeof(cb_rec->cbr_stateid) + len);
	WRITE32(OP_CB_RECALL);
	WRITEMEM(&cb_rec->cbr_stateid, sizeof(stateid_t));
	WRITE32(cb_rec->cbr_trunc);
	WRITE32(len);
	WRITEMEM(cb_rec->cbr_fhval, len);
	return 0;
}

static int
nfs4_xdr_enc_cb_null(struct rpc_rqst *req, __be32 *p)
{
	struct xdr_stream xdrs, *xdr = &xdrs;

	xdr_init_encode(&xdrs, &req->rq_snd_buf, p);
        RESERVE_SPACE(0);
	return 0;
}

static int
nfs4_xdr_enc_cb_recall(struct rpc_rqst *req, __be32 *p, struct nfs4_cb_recall *args)
{
	struct xdr_stream xdr;
	struct nfs4_cb_compound_hdr hdr = {
		.ident = args->cbr_ident,
		.nops   = 1,
	};

	xdr_init_encode(&xdr, &req->rq_snd_buf, p);
	encode_cb_compound_hdr(&xdr, &hdr);
	return (encode_cb_recall(&xdr, args));
}


static int
decode_cb_compound_hdr(struct xdr_stream *xdr, struct nfs4_cb_compound_hdr *hdr){
        __be32 *p;

        READ_BUF(8);
        READ32(hdr->status);
        READ32(hdr->taglen);
        READ_BUF(hdr->taglen + 4);
        hdr->tag = (char *)p;
        p += XDR_QUADLEN(hdr->taglen);
        READ32(hdr->nops);
        return 0;
}

static int
decode_cb_op_hdr(struct xdr_stream *xdr, enum nfs_opnum4 expected)
{
	__be32 *p;
	u32 op;
	int32_t nfserr;

	READ_BUF(8);
	READ32(op);
	if (op != expected) {
		dprintk("NFSD: decode_cb_op_hdr: Callback server returned "
		         " operation %d but we issued a request for %d\n",
		         op, expected);
		return -EIO;
	}
	READ32(nfserr);
	if (nfserr != NFS_OK)
		return -nfs_cb_stat_to_errno(nfserr);
	return 0;
}

static int
nfs4_xdr_dec_cb_null(struct rpc_rqst *req, __be32 *p)
{
	return 0;
}

static int
nfs4_xdr_dec_cb_recall(struct rpc_rqst *rqstp, __be32 *p)
{
	struct xdr_stream xdr;
	struct nfs4_cb_compound_hdr hdr;
	int status;

	xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, p);
	status = decode_cb_compound_hdr(&xdr, &hdr);
	if (status)
		goto out;
	status = decode_cb_op_hdr(&xdr, OP_CB_RECALL);
out:
	return status;
}

/*
 * RPC procedure tables
 */
#define PROC(proc, call, argtype, restype)                              \
[NFSPROC4_CLNT_##proc] = {                                      	\
        .p_proc   = NFSPROC4_CB_##call,					\
        .p_encode = (kxdrproc_t) nfs4_xdr_##argtype,                    \
        .p_decode = (kxdrproc_t) nfs4_xdr_##restype,                    \
        .p_arglen = NFS4_##argtype##_sz,                                \
        .p_replen = NFS4_##restype##_sz,                                \
        .p_statidx = NFSPROC4_CB_##call,				\
	.p_name   = #proc,                                              \
}

static struct rpc_procinfo     nfs4_cb_procedures[] = {
    PROC(CB_NULL,      NULL,     enc_cb_null,     dec_cb_null),
    PROC(CB_RECALL,    COMPOUND,   enc_cb_recall,      dec_cb_recall),
};

static struct rpc_version       nfs_cb_version4 = {
        .number                 = 1,
        .nrprocs                = ARRAY_SIZE(nfs4_cb_procedures),
        .procs                  = nfs4_cb_procedures
};

static struct rpc_version *	nfs_cb_version[] = {
	NULL,
	&nfs_cb_version4,
};

/* Reference counting, callback cleanup, etc., all look racy as heck.
 * And why is cb_set an atomic? */

static int do_probe_callback(void *data)
{
	struct nfs4_client *clp = data;
	struct sockaddr_in	addr;
	struct nfs4_callback    *cb = &clp->cl_callback;
	struct rpc_timeout	timeparms = {
		.to_initval	= (NFSD_LEASE_TIME/4) * HZ,
		.to_retries	= 5,
		.to_maxval	= (NFSD_LEASE_TIME/2) * HZ,
		.to_exponential	= 1,
	};
	struct rpc_program *	program = &cb->cb_program;
	struct rpc_create_args args = {
		.protocol	= IPPROTO_TCP,
		.address	= (struct sockaddr *)&addr,
		.addrsize	= sizeof(addr),
		.timeout	= &timeparms,
		.program	= program,
		.version	= nfs_cb_version[1]->number,
		.authflavor	= RPC_AUTH_UNIX, /* XXX: need AUTH_GSS... */
		.flags		= (RPC_CLNT_CREATE_NOPING),
	};
	struct rpc_message msg = {
		.rpc_proc       = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_NULL],
		.rpc_argp       = clp,
	};
	struct rpc_clnt *client;
	int status;

	/* Initialize address */
	memset(&addr, 0, sizeof(addr));
	addr.sin_family = AF_INET;
	addr.sin_port = htons(cb->cb_port);
	addr.sin_addr.s_addr = htonl(cb->cb_addr);

	/* Initialize rpc_program */
	program->name = "nfs4_cb";
	program->number = cb->cb_prog;
	program->nrvers = ARRAY_SIZE(nfs_cb_version);
	program->version = nfs_cb_version;
	program->stats = &cb->cb_stat;

	/* Initialize rpc_stat */
	memset(program->stats, 0, sizeof(cb->cb_stat));
	program->stats->program = program;

	/* Create RPC client */
	client = rpc_create(&args);
	if (IS_ERR(client)) {
		dprintk("NFSD: couldn't create callback client\n");
		status = PTR_ERR(client);
		goto out_err;
	}

	status = rpc_call_sync(client, &msg, RPC_TASK_SOFT);

	if (status)
		goto out_release_client;

	cb->cb_client = client;
	atomic_set(&cb->cb_set, 1);
	put_nfs4_client(clp);
	return 0;
out_release_client:
	rpc_shutdown_client(client);
out_err:
	put_nfs4_client(clp);
	dprintk("NFSD: warning: no callback path to client %.*s\n",
		(int)clp->cl_name.len, clp->cl_name.data);
	return status;
}

/*
 * Set up the callback client and put a NFSPROC4_CB_NULL on the wire...
 */
void
nfsd4_probe_callback(struct nfs4_client *clp)
{
	struct task_struct *t;

	BUG_ON(atomic_read(&clp->cl_callback.cb_set));

	/* the task holds a reference to the nfs4_client struct */
	atomic_inc(&clp->cl_count);

	t = kthread_run(do_probe_callback, clp, "nfs4_cb_probe");

	if (IS_ERR(t))
		atomic_dec(&clp->cl_count);

	return;
}

/*
 * called with dp->dl_count inc'ed.
 * nfs4_lock_state() may or may not have been called.
 */
void
nfsd4_cb_recall(struct nfs4_delegation *dp)
{
	struct nfs4_client *clp = dp->dl_client;
	struct rpc_clnt *clnt = clp->cl_callback.cb_client;
	struct nfs4_cb_recall *cbr = &dp->dl_recall;
	struct rpc_message msg = {
		.rpc_proc = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_RECALL],
		.rpc_argp = cbr,
	};
	int retries = 1;
	int status = 0;

	if ((!atomic_read(&clp->cl_callback.cb_set)) || !clnt)
		return;

	cbr->cbr_trunc = 0; /* XXX need to implement truncate optimization */
	cbr->cbr_dp = dp;

	status = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT);
	while (retries--) {
		switch (status) {
			case -EIO:
				/* Network partition? */
			case -EBADHANDLE:
			case -NFS4ERR_BAD_STATEID:
				/* Race: client probably got cb_recall
				 * before open reply granting delegation */
				break;
			default:
				goto out_put_cred;
		}
		ssleep(2);
		status = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT);
	}
out_put_cred:
	if (status == -EIO)
		atomic_set(&clp->cl_callback.cb_set, 0);
	/* Success or failure, now we're either waiting for lease expiration
	 * or deleg_return. */
	dprintk("NFSD: nfs4_cb_recall: dp %p dl_flock %p dl_count %d\n",dp, dp->dl_flock, atomic_read(&dp->dl_count));
	put_nfs4_client(clp);
	nfs4_put_delegation(dp);
	return;
}