xref: /openbmc/linux/fs/nfs/proc.c (revision c6cb80d0)
1 /*
2  *  linux/fs/nfs/proc.c
3  *
4  *  Copyright (C) 1992, 1993, 1994  Rick Sladkey
5  *
6  *  OS-independent nfs remote procedure call functions
7  *
8  *  Tuned by Alan Cox <A.Cox@swansea.ac.uk> for >3K buffers
9  *  so at last we can have decent(ish) throughput off a
10  *  Sun server.
11  *
12  *  Coding optimized and cleaned up by Florian La Roche.
13  *  Note: Error returns are optimized for NFS_OK, which isn't translated via
14  *  nfs_stat_to_errno(), but happens to be already the right return code.
15  *
16  *  Also, the code currently doesn't check the size of the packet, when
17  *  it decodes the packet.
18  *
19  *  Feel free to fix it and mail me the diffs if it worries you.
20  *
21  *  Completely rewritten to support the new RPC call interface;
22  *  rewrote and moved the entire XDR stuff to xdr.c
23  *  --Olaf Kirch June 1996
24  *
25  *  The code below initializes all auto variables explicitly, otherwise
26  *  it will fail to work as a module (gcc generates a memset call for an
27  *  incomplete struct).
28  */
29 
30 #include <linux/types.h>
31 #include <linux/param.h>
32 #include <linux/time.h>
33 #include <linux/mm.h>
34 #include <linux/errno.h>
35 #include <linux/string.h>
36 #include <linux/in.h>
37 #include <linux/pagemap.h>
38 #include <linux/sunrpc/clnt.h>
39 #include <linux/nfs.h>
40 #include <linux/nfs2.h>
41 #include <linux/nfs_fs.h>
42 #include <linux/nfs_page.h>
43 #include <linux/lockd/bind.h>
44 #include <linux/freezer.h>
45 #include "internal.h"
46 
47 #define NFSDBG_FACILITY		NFSDBG_PROC
48 
49 /*
50  * wrapper to handle the -EKEYEXPIRED error message. This should generally
51  * only happen if using krb5 auth and a user's TGT expires. NFSv2 doesn't
52  * support the NFSERR_JUKEBOX error code, but we handle this situation in the
53  * same way that we handle that error with NFSv3.
54  */
55 static int
56 nfs_rpc_wrapper(struct rpc_clnt *clnt, struct rpc_message *msg, int flags)
57 {
58 	int res;
59 	do {
60 		res = rpc_call_sync(clnt, msg, flags);
61 		if (res != -EKEYEXPIRED)
62 			break;
63 		freezable_schedule_timeout_killable(NFS_JUKEBOX_RETRY_TIME);
64 		res = -ERESTARTSYS;
65 	} while (!fatal_signal_pending(current));
66 	return res;
67 }
68 
69 #define rpc_call_sync(clnt, msg, flags)	nfs_rpc_wrapper(clnt, msg, flags)
70 
71 static int
72 nfs_async_handle_expired_key(struct rpc_task *task)
73 {
74 	if (task->tk_status != -EKEYEXPIRED)
75 		return 0;
76 	task->tk_status = 0;
77 	rpc_restart_call(task);
78 	rpc_delay(task, NFS_JUKEBOX_RETRY_TIME);
79 	return 1;
80 }
81 
82 /*
83  * Bare-bones access to getattr: this is for nfs_read_super.
84  */
85 static int
86 nfs_proc_get_root(struct nfs_server *server, struct nfs_fh *fhandle,
87 		  struct nfs_fsinfo *info)
88 {
89 	struct nfs_fattr *fattr = info->fattr;
90 	struct nfs2_fsstat fsinfo;
91 	struct rpc_message msg = {
92 		.rpc_proc	= &nfs_procedures[NFSPROC_GETATTR],
93 		.rpc_argp	= fhandle,
94 		.rpc_resp	= fattr,
95 	};
96 	int status;
97 
98 	dprintk("%s: call getattr\n", __func__);
99 	nfs_fattr_init(fattr);
100 	status = rpc_call_sync(server->client, &msg, 0);
101 	/* Retry with default authentication if different */
102 	if (status && server->nfs_client->cl_rpcclient != server->client)
103 		status = rpc_call_sync(server->nfs_client->cl_rpcclient, &msg, 0);
104 	dprintk("%s: reply getattr: %d\n", __func__, status);
105 	if (status)
106 		return status;
107 	dprintk("%s: call statfs\n", __func__);
108 	msg.rpc_proc = &nfs_procedures[NFSPROC_STATFS];
109 	msg.rpc_resp = &fsinfo;
110 	status = rpc_call_sync(server->client, &msg, 0);
111 	/* Retry with default authentication if different */
112 	if (status && server->nfs_client->cl_rpcclient != server->client)
113 		status = rpc_call_sync(server->nfs_client->cl_rpcclient, &msg, 0);
114 	dprintk("%s: reply statfs: %d\n", __func__, status);
115 	if (status)
116 		return status;
117 	info->rtmax  = NFS_MAXDATA;
118 	info->rtpref = fsinfo.tsize;
119 	info->rtmult = fsinfo.bsize;
120 	info->wtmax  = NFS_MAXDATA;
121 	info->wtpref = fsinfo.tsize;
122 	info->wtmult = fsinfo.bsize;
123 	info->dtpref = fsinfo.tsize;
124 	info->maxfilesize = 0x7FFFFFFF;
125 	info->lease_time = 0;
126 	return 0;
127 }
128 
129 /*
130  * One function for each procedure in the NFS protocol.
131  */
132 static int
133 nfs_proc_getattr(struct nfs_server *server, struct nfs_fh *fhandle,
134 		struct nfs_fattr *fattr)
135 {
136 	struct rpc_message msg = {
137 		.rpc_proc	= &nfs_procedures[NFSPROC_GETATTR],
138 		.rpc_argp	= fhandle,
139 		.rpc_resp	= fattr,
140 	};
141 	int	status;
142 
143 	dprintk("NFS call  getattr\n");
144 	nfs_fattr_init(fattr);
145 	status = rpc_call_sync(server->client, &msg, 0);
146 	dprintk("NFS reply getattr: %d\n", status);
147 	return status;
148 }
149 
150 static int
151 nfs_proc_setattr(struct dentry *dentry, struct nfs_fattr *fattr,
152 		 struct iattr *sattr)
153 {
154 	struct inode *inode = dentry->d_inode;
155 	struct nfs_sattrargs	arg = {
156 		.fh	= NFS_FH(inode),
157 		.sattr	= sattr
158 	};
159 	struct rpc_message msg = {
160 		.rpc_proc	= &nfs_procedures[NFSPROC_SETATTR],
161 		.rpc_argp	= &arg,
162 		.rpc_resp	= fattr,
163 	};
164 	int	status;
165 
166 	/* Mask out the non-modebit related stuff from attr->ia_mode */
167 	sattr->ia_mode &= S_IALLUGO;
168 
169 	dprintk("NFS call  setattr\n");
170 	if (sattr->ia_valid & ATTR_FILE)
171 		msg.rpc_cred = nfs_file_cred(sattr->ia_file);
172 	nfs_fattr_init(fattr);
173 	status = rpc_call_sync(NFS_CLIENT(inode), &msg, 0);
174 	if (status == 0)
175 		nfs_setattr_update_inode(inode, sattr);
176 	dprintk("NFS reply setattr: %d\n", status);
177 	return status;
178 }
179 
180 static int
181 nfs_proc_lookup(struct rpc_clnt *clnt, struct inode *dir, struct qstr *name,
182 		struct nfs_fh *fhandle, struct nfs_fattr *fattr)
183 {
184 	struct nfs_diropargs	arg = {
185 		.fh		= NFS_FH(dir),
186 		.name		= name->name,
187 		.len		= name->len
188 	};
189 	struct nfs_diropok	res = {
190 		.fh		= fhandle,
191 		.fattr		= fattr
192 	};
193 	struct rpc_message msg = {
194 		.rpc_proc	= &nfs_procedures[NFSPROC_LOOKUP],
195 		.rpc_argp	= &arg,
196 		.rpc_resp	= &res,
197 	};
198 	int			status;
199 
200 	dprintk("NFS call  lookup %s\n", name->name);
201 	nfs_fattr_init(fattr);
202 	status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
203 	dprintk("NFS reply lookup: %d\n", status);
204 	return status;
205 }
206 
207 static int nfs_proc_readlink(struct inode *inode, struct page *page,
208 		unsigned int pgbase, unsigned int pglen)
209 {
210 	struct nfs_readlinkargs	args = {
211 		.fh		= NFS_FH(inode),
212 		.pgbase		= pgbase,
213 		.pglen		= pglen,
214 		.pages		= &page
215 	};
216 	struct rpc_message msg = {
217 		.rpc_proc	= &nfs_procedures[NFSPROC_READLINK],
218 		.rpc_argp	= &args,
219 	};
220 	int			status;
221 
222 	dprintk("NFS call  readlink\n");
223 	status = rpc_call_sync(NFS_CLIENT(inode), &msg, 0);
224 	dprintk("NFS reply readlink: %d\n", status);
225 	return status;
226 }
227 
228 struct nfs_createdata {
229 	struct nfs_createargs arg;
230 	struct nfs_diropok res;
231 	struct nfs_fh fhandle;
232 	struct nfs_fattr fattr;
233 };
234 
235 static struct nfs_createdata *nfs_alloc_createdata(struct inode *dir,
236 		struct dentry *dentry, struct iattr *sattr)
237 {
238 	struct nfs_createdata *data;
239 
240 	data = kmalloc(sizeof(*data), GFP_KERNEL);
241 
242 	if (data != NULL) {
243 		data->arg.fh = NFS_FH(dir);
244 		data->arg.name = dentry->d_name.name;
245 		data->arg.len = dentry->d_name.len;
246 		data->arg.sattr = sattr;
247 		nfs_fattr_init(&data->fattr);
248 		data->fhandle.size = 0;
249 		data->res.fh = &data->fhandle;
250 		data->res.fattr = &data->fattr;
251 	}
252 	return data;
253 };
254 
255 static void nfs_free_createdata(const struct nfs_createdata *data)
256 {
257 	kfree(data);
258 }
259 
260 static int
261 nfs_proc_create(struct inode *dir, struct dentry *dentry, struct iattr *sattr,
262 		int flags, struct nfs_open_context *ctx)
263 {
264 	struct nfs_createdata *data;
265 	struct rpc_message msg = {
266 		.rpc_proc	= &nfs_procedures[NFSPROC_CREATE],
267 	};
268 	int status = -ENOMEM;
269 
270 	dprintk("NFS call  create %s\n", dentry->d_name.name);
271 	data = nfs_alloc_createdata(dir, dentry, sattr);
272 	if (data == NULL)
273 		goto out;
274 	msg.rpc_argp = &data->arg;
275 	msg.rpc_resp = &data->res;
276 	status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
277 	nfs_mark_for_revalidate(dir);
278 	if (status == 0)
279 		status = nfs_instantiate(dentry, data->res.fh, data->res.fattr);
280 	nfs_free_createdata(data);
281 out:
282 	dprintk("NFS reply create: %d\n", status);
283 	return status;
284 }
285 
286 /*
287  * In NFSv2, mknod is grafted onto the create call.
288  */
289 static int
290 nfs_proc_mknod(struct inode *dir, struct dentry *dentry, struct iattr *sattr,
291 	       dev_t rdev)
292 {
293 	struct nfs_createdata *data;
294 	struct rpc_message msg = {
295 		.rpc_proc	= &nfs_procedures[NFSPROC_CREATE],
296 	};
297 	umode_t mode;
298 	int status = -ENOMEM;
299 
300 	dprintk("NFS call  mknod %s\n", dentry->d_name.name);
301 
302 	mode = sattr->ia_mode;
303 	if (S_ISFIFO(mode)) {
304 		sattr->ia_mode = (mode & ~S_IFMT) | S_IFCHR;
305 		sattr->ia_valid &= ~ATTR_SIZE;
306 	} else if (S_ISCHR(mode) || S_ISBLK(mode)) {
307 		sattr->ia_valid |= ATTR_SIZE;
308 		sattr->ia_size = new_encode_dev(rdev);/* get out your barf bag */
309 	}
310 
311 	data = nfs_alloc_createdata(dir, dentry, sattr);
312 	if (data == NULL)
313 		goto out;
314 	msg.rpc_argp = &data->arg;
315 	msg.rpc_resp = &data->res;
316 
317 	status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
318 	nfs_mark_for_revalidate(dir);
319 
320 	if (status == -EINVAL && S_ISFIFO(mode)) {
321 		sattr->ia_mode = mode;
322 		nfs_fattr_init(data->res.fattr);
323 		status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
324 	}
325 	if (status == 0)
326 		status = nfs_instantiate(dentry, data->res.fh, data->res.fattr);
327 	nfs_free_createdata(data);
328 out:
329 	dprintk("NFS reply mknod: %d\n", status);
330 	return status;
331 }
332 
333 static int
334 nfs_proc_remove(struct inode *dir, struct qstr *name)
335 {
336 	struct nfs_removeargs arg = {
337 		.fh = NFS_FH(dir),
338 		.name.len = name->len,
339 		.name.name = name->name,
340 	};
341 	struct rpc_message msg = {
342 		.rpc_proc = &nfs_procedures[NFSPROC_REMOVE],
343 		.rpc_argp = &arg,
344 	};
345 	int			status;
346 
347 	dprintk("NFS call  remove %s\n", name->name);
348 	status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
349 	nfs_mark_for_revalidate(dir);
350 
351 	dprintk("NFS reply remove: %d\n", status);
352 	return status;
353 }
354 
355 static void
356 nfs_proc_unlink_setup(struct rpc_message *msg, struct inode *dir)
357 {
358 	msg->rpc_proc = &nfs_procedures[NFSPROC_REMOVE];
359 }
360 
361 static int nfs_proc_unlink_done(struct rpc_task *task, struct inode *dir)
362 {
363 	if (nfs_async_handle_expired_key(task))
364 		return 0;
365 	nfs_mark_for_revalidate(dir);
366 	return 1;
367 }
368 
369 static void
370 nfs_proc_rename_setup(struct rpc_message *msg, struct inode *dir)
371 {
372 	msg->rpc_proc = &nfs_procedures[NFSPROC_RENAME];
373 }
374 
375 static int
376 nfs_proc_rename_done(struct rpc_task *task, struct inode *old_dir,
377 		     struct inode *new_dir)
378 {
379 	if (nfs_async_handle_expired_key(task))
380 		return 0;
381 	nfs_mark_for_revalidate(old_dir);
382 	nfs_mark_for_revalidate(new_dir);
383 	return 1;
384 }
385 
386 static int
387 nfs_proc_rename(struct inode *old_dir, struct qstr *old_name,
388 		struct inode *new_dir, struct qstr *new_name)
389 {
390 	struct nfs_renameargs	arg = {
391 		.old_dir	= NFS_FH(old_dir),
392 		.old_name	= old_name,
393 		.new_dir	= NFS_FH(new_dir),
394 		.new_name	= new_name,
395 	};
396 	struct rpc_message msg = {
397 		.rpc_proc	= &nfs_procedures[NFSPROC_RENAME],
398 		.rpc_argp	= &arg,
399 	};
400 	int			status;
401 
402 	dprintk("NFS call  rename %s -> %s\n", old_name->name, new_name->name);
403 	status = rpc_call_sync(NFS_CLIENT(old_dir), &msg, 0);
404 	nfs_mark_for_revalidate(old_dir);
405 	nfs_mark_for_revalidate(new_dir);
406 	dprintk("NFS reply rename: %d\n", status);
407 	return status;
408 }
409 
410 static int
411 nfs_proc_link(struct inode *inode, struct inode *dir, struct qstr *name)
412 {
413 	struct nfs_linkargs	arg = {
414 		.fromfh		= NFS_FH(inode),
415 		.tofh		= NFS_FH(dir),
416 		.toname		= name->name,
417 		.tolen		= name->len
418 	};
419 	struct rpc_message msg = {
420 		.rpc_proc	= &nfs_procedures[NFSPROC_LINK],
421 		.rpc_argp	= &arg,
422 	};
423 	int			status;
424 
425 	dprintk("NFS call  link %s\n", name->name);
426 	status = rpc_call_sync(NFS_CLIENT(inode), &msg, 0);
427 	nfs_mark_for_revalidate(inode);
428 	nfs_mark_for_revalidate(dir);
429 	dprintk("NFS reply link: %d\n", status);
430 	return status;
431 }
432 
433 static int
434 nfs_proc_symlink(struct inode *dir, struct dentry *dentry, struct page *page,
435 		 unsigned int len, struct iattr *sattr)
436 {
437 	struct nfs_fh *fh;
438 	struct nfs_fattr *fattr;
439 	struct nfs_symlinkargs	arg = {
440 		.fromfh		= NFS_FH(dir),
441 		.fromname	= dentry->d_name.name,
442 		.fromlen	= dentry->d_name.len,
443 		.pages		= &page,
444 		.pathlen	= len,
445 		.sattr		= sattr
446 	};
447 	struct rpc_message msg = {
448 		.rpc_proc	= &nfs_procedures[NFSPROC_SYMLINK],
449 		.rpc_argp	= &arg,
450 	};
451 	int status = -ENAMETOOLONG;
452 
453 	dprintk("NFS call  symlink %s\n", dentry->d_name.name);
454 
455 	if (len > NFS2_MAXPATHLEN)
456 		goto out;
457 
458 	fh = nfs_alloc_fhandle();
459 	fattr = nfs_alloc_fattr();
460 	status = -ENOMEM;
461 	if (fh == NULL || fattr == NULL)
462 		goto out_free;
463 
464 	status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
465 	nfs_mark_for_revalidate(dir);
466 
467 	/*
468 	 * V2 SYMLINK requests don't return any attributes.  Setting the
469 	 * filehandle size to zero indicates to nfs_instantiate that it
470 	 * should fill in the data with a LOOKUP call on the wire.
471 	 */
472 	if (status == 0)
473 		status = nfs_instantiate(dentry, fh, fattr);
474 
475 out_free:
476 	nfs_free_fattr(fattr);
477 	nfs_free_fhandle(fh);
478 out:
479 	dprintk("NFS reply symlink: %d\n", status);
480 	return status;
481 }
482 
483 static int
484 nfs_proc_mkdir(struct inode *dir, struct dentry *dentry, struct iattr *sattr)
485 {
486 	struct nfs_createdata *data;
487 	struct rpc_message msg = {
488 		.rpc_proc	= &nfs_procedures[NFSPROC_MKDIR],
489 	};
490 	int status = -ENOMEM;
491 
492 	dprintk("NFS call  mkdir %s\n", dentry->d_name.name);
493 	data = nfs_alloc_createdata(dir, dentry, sattr);
494 	if (data == NULL)
495 		goto out;
496 	msg.rpc_argp = &data->arg;
497 	msg.rpc_resp = &data->res;
498 
499 	status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
500 	nfs_mark_for_revalidate(dir);
501 	if (status == 0)
502 		status = nfs_instantiate(dentry, data->res.fh, data->res.fattr);
503 	nfs_free_createdata(data);
504 out:
505 	dprintk("NFS reply mkdir: %d\n", status);
506 	return status;
507 }
508 
509 static int
510 nfs_proc_rmdir(struct inode *dir, struct qstr *name)
511 {
512 	struct nfs_diropargs	arg = {
513 		.fh		= NFS_FH(dir),
514 		.name		= name->name,
515 		.len		= name->len
516 	};
517 	struct rpc_message msg = {
518 		.rpc_proc	= &nfs_procedures[NFSPROC_RMDIR],
519 		.rpc_argp	= &arg,
520 	};
521 	int			status;
522 
523 	dprintk("NFS call  rmdir %s\n", name->name);
524 	status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
525 	nfs_mark_for_revalidate(dir);
526 	dprintk("NFS reply rmdir: %d\n", status);
527 	return status;
528 }
529 
530 /*
531  * The READDIR implementation is somewhat hackish - we pass a temporary
532  * buffer to the encode function, which installs it in the receive
533  * the receive iovec. The decode function just parses the reply to make
534  * sure it is syntactically correct; the entries itself are decoded
535  * from nfs_readdir by calling the decode_entry function directly.
536  */
537 static int
538 nfs_proc_readdir(struct dentry *dentry, struct rpc_cred *cred,
539 		 u64 cookie, struct page **pages, unsigned int count, int plus)
540 {
541 	struct inode		*dir = dentry->d_inode;
542 	struct nfs_readdirargs	arg = {
543 		.fh		= NFS_FH(dir),
544 		.cookie		= cookie,
545 		.count		= count,
546 		.pages		= pages,
547 	};
548 	struct rpc_message	msg = {
549 		.rpc_proc	= &nfs_procedures[NFSPROC_READDIR],
550 		.rpc_argp	= &arg,
551 		.rpc_cred	= cred,
552 	};
553 	int			status;
554 
555 	dprintk("NFS call  readdir %d\n", (unsigned int)cookie);
556 	status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
557 
558 	nfs_invalidate_atime(dir);
559 
560 	dprintk("NFS reply readdir: %d\n", status);
561 	return status;
562 }
563 
564 static int
565 nfs_proc_statfs(struct nfs_server *server, struct nfs_fh *fhandle,
566 			struct nfs_fsstat *stat)
567 {
568 	struct nfs2_fsstat fsinfo;
569 	struct rpc_message msg = {
570 		.rpc_proc	= &nfs_procedures[NFSPROC_STATFS],
571 		.rpc_argp	= fhandle,
572 		.rpc_resp	= &fsinfo,
573 	};
574 	int	status;
575 
576 	dprintk("NFS call  statfs\n");
577 	nfs_fattr_init(stat->fattr);
578 	status = rpc_call_sync(server->client, &msg, 0);
579 	dprintk("NFS reply statfs: %d\n", status);
580 	if (status)
581 		goto out;
582 	stat->tbytes = (u64)fsinfo.blocks * fsinfo.bsize;
583 	stat->fbytes = (u64)fsinfo.bfree  * fsinfo.bsize;
584 	stat->abytes = (u64)fsinfo.bavail * fsinfo.bsize;
585 	stat->tfiles = 0;
586 	stat->ffiles = 0;
587 	stat->afiles = 0;
588 out:
589 	return status;
590 }
591 
592 static int
593 nfs_proc_fsinfo(struct nfs_server *server, struct nfs_fh *fhandle,
594 			struct nfs_fsinfo *info)
595 {
596 	struct nfs2_fsstat fsinfo;
597 	struct rpc_message msg = {
598 		.rpc_proc	= &nfs_procedures[NFSPROC_STATFS],
599 		.rpc_argp	= fhandle,
600 		.rpc_resp	= &fsinfo,
601 	};
602 	int	status;
603 
604 	dprintk("NFS call  fsinfo\n");
605 	nfs_fattr_init(info->fattr);
606 	status = rpc_call_sync(server->client, &msg, 0);
607 	dprintk("NFS reply fsinfo: %d\n", status);
608 	if (status)
609 		goto out;
610 	info->rtmax  = NFS_MAXDATA;
611 	info->rtpref = fsinfo.tsize;
612 	info->rtmult = fsinfo.bsize;
613 	info->wtmax  = NFS_MAXDATA;
614 	info->wtpref = fsinfo.tsize;
615 	info->wtmult = fsinfo.bsize;
616 	info->dtpref = fsinfo.tsize;
617 	info->maxfilesize = 0x7FFFFFFF;
618 	info->lease_time = 0;
619 out:
620 	return status;
621 }
622 
623 static int
624 nfs_proc_pathconf(struct nfs_server *server, struct nfs_fh *fhandle,
625 		  struct nfs_pathconf *info)
626 {
627 	info->max_link = 0;
628 	info->max_namelen = NFS2_MAXNAMLEN;
629 	return 0;
630 }
631 
632 static int nfs_read_done(struct rpc_task *task, struct nfs_read_data *data)
633 {
634 	if (nfs_async_handle_expired_key(task))
635 		return -EAGAIN;
636 
637 	nfs_invalidate_atime(data->inode);
638 	if (task->tk_status >= 0) {
639 		nfs_refresh_inode(data->inode, data->res.fattr);
640 		/* Emulate the eof flag, which isn't normally needed in NFSv2
641 		 * as it is guaranteed to always return the file attributes
642 		 */
643 		if (data->args.offset + data->args.count >= data->res.fattr->size)
644 			data->res.eof = 1;
645 	}
646 	return 0;
647 }
648 
649 static void nfs_proc_read_setup(struct nfs_read_data *data, struct rpc_message *msg)
650 {
651 	msg->rpc_proc = &nfs_procedures[NFSPROC_READ];
652 }
653 
654 static int nfs_write_done(struct rpc_task *task, struct nfs_write_data *data)
655 {
656 	if (nfs_async_handle_expired_key(task))
657 		return -EAGAIN;
658 
659 	if (task->tk_status >= 0)
660 		nfs_post_op_update_inode_force_wcc(data->inode, data->res.fattr);
661 	return 0;
662 }
663 
664 static void nfs_proc_write_setup(struct nfs_write_data *data, struct rpc_message *msg)
665 {
666 	/* Note: NFSv2 ignores @stable and always uses NFS_FILE_SYNC */
667 	data->args.stable = NFS_FILE_SYNC;
668 	msg->rpc_proc = &nfs_procedures[NFSPROC_WRITE];
669 }
670 
671 static void nfs_proc_write_rpc_prepare(struct rpc_task *task, struct nfs_write_data *data)
672 {
673 	rpc_call_start(task);
674 }
675 
676 static void
677 nfs_proc_commit_setup(struct nfs_write_data *data, struct rpc_message *msg)
678 {
679 	BUG();
680 }
681 
682 static int
683 nfs_proc_lock(struct file *filp, int cmd, struct file_lock *fl)
684 {
685 	struct inode *inode = filp->f_path.dentry->d_inode;
686 
687 	return nlmclnt_proc(NFS_SERVER(inode)->nlm_host, cmd, fl);
688 }
689 
690 /* Helper functions for NFS lock bounds checking */
691 #define NFS_LOCK32_OFFSET_MAX ((__s32)0x7fffffffUL)
692 static int nfs_lock_check_bounds(const struct file_lock *fl)
693 {
694 	__s32 start, end;
695 
696 	start = (__s32)fl->fl_start;
697 	if ((loff_t)start != fl->fl_start)
698 		goto out_einval;
699 
700 	if (fl->fl_end != OFFSET_MAX) {
701 		end = (__s32)fl->fl_end;
702 		if ((loff_t)end != fl->fl_end)
703 			goto out_einval;
704 	} else
705 		end = NFS_LOCK32_OFFSET_MAX;
706 
707 	if (start < 0 || start > end)
708 		goto out_einval;
709 	return 0;
710 out_einval:
711 	return -EINVAL;
712 }
713 
714 const struct nfs_rpc_ops nfs_v2_clientops = {
715 	.version	= 2,		       /* protocol version */
716 	.dentry_ops	= &nfs_dentry_operations,
717 	.dir_inode_ops	= &nfs_dir_inode_operations,
718 	.file_inode_ops	= &nfs_file_inode_operations,
719 	.file_ops	= &nfs_file_operations,
720 	.getroot	= nfs_proc_get_root,
721 	.getattr	= nfs_proc_getattr,
722 	.setattr	= nfs_proc_setattr,
723 	.lookup		= nfs_proc_lookup,
724 	.access		= NULL,		       /* access */
725 	.readlink	= nfs_proc_readlink,
726 	.create		= nfs_proc_create,
727 	.remove		= nfs_proc_remove,
728 	.unlink_setup	= nfs_proc_unlink_setup,
729 	.unlink_done	= nfs_proc_unlink_done,
730 	.rename		= nfs_proc_rename,
731 	.rename_setup	= nfs_proc_rename_setup,
732 	.rename_done	= nfs_proc_rename_done,
733 	.link		= nfs_proc_link,
734 	.symlink	= nfs_proc_symlink,
735 	.mkdir		= nfs_proc_mkdir,
736 	.rmdir		= nfs_proc_rmdir,
737 	.readdir	= nfs_proc_readdir,
738 	.mknod		= nfs_proc_mknod,
739 	.statfs		= nfs_proc_statfs,
740 	.fsinfo		= nfs_proc_fsinfo,
741 	.pathconf	= nfs_proc_pathconf,
742 	.decode_dirent	= nfs2_decode_dirent,
743 	.read_setup	= nfs_proc_read_setup,
744 	.read_done	= nfs_read_done,
745 	.write_setup	= nfs_proc_write_setup,
746 	.write_rpc_prepare = nfs_proc_write_rpc_prepare,
747 	.write_done	= nfs_write_done,
748 	.commit_setup	= nfs_proc_commit_setup,
749 	.lock		= nfs_proc_lock,
750 	.lock_check_bounds = nfs_lock_check_bounds,
751 	.close_context	= nfs_close_context,
752 	.init_client	= nfs_init_client,
753 };
754