xref: /openbmc/linux/fs/nfsd/nfsctl.c (revision 2a12187d)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Syscall interface to knfsd.
4  *
5  * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
6  */
7 
8 #include <linux/slab.h>
9 #include <linux/namei.h>
10 #include <linux/ctype.h>
11 #include <linux/fs_context.h>
12 
13 #include <linux/sunrpc/svcsock.h>
14 #include <linux/lockd/lockd.h>
15 #include <linux/sunrpc/addr.h>
16 #include <linux/sunrpc/gss_api.h>
17 #include <linux/sunrpc/gss_krb5_enctypes.h>
18 #include <linux/sunrpc/rpc_pipe_fs.h>
19 #include <linux/module.h>
20 #include <linux/fsnotify.h>
21 
22 #include "idmap.h"
23 #include "nfsd.h"
24 #include "cache.h"
25 #include "state.h"
26 #include "netns.h"
27 #include "pnfs.h"
28 #include "filecache.h"
29 
30 /*
31  *	We have a single directory with several nodes in it.
32  */
33 enum {
34 	NFSD_Root = 1,
35 	NFSD_List,
36 	NFSD_Export_Stats,
37 	NFSD_Export_features,
38 	NFSD_Fh,
39 	NFSD_FO_UnlockIP,
40 	NFSD_FO_UnlockFS,
41 	NFSD_Threads,
42 	NFSD_Pool_Threads,
43 	NFSD_Pool_Stats,
44 	NFSD_Reply_Cache_Stats,
45 	NFSD_Versions,
46 	NFSD_Ports,
47 	NFSD_MaxBlkSize,
48 	NFSD_MaxConnections,
49 	NFSD_Filecache,
50 	NFSD_SupportedEnctypes,
51 	/*
52 	 * The below MUST come last.  Otherwise we leave a hole in nfsd_files[]
53 	 * with !CONFIG_NFSD_V4 and simple_fill_super() goes oops
54 	 */
55 #ifdef CONFIG_NFSD_V4
56 	NFSD_Leasetime,
57 	NFSD_Gracetime,
58 	NFSD_RecoveryDir,
59 	NFSD_V4EndGrace,
60 #endif
61 	NFSD_MaxReserved
62 };
63 
64 /*
65  * write() for these nodes.
66  */
67 static ssize_t write_filehandle(struct file *file, char *buf, size_t size);
68 static ssize_t write_unlock_ip(struct file *file, char *buf, size_t size);
69 static ssize_t write_unlock_fs(struct file *file, char *buf, size_t size);
70 static ssize_t write_threads(struct file *file, char *buf, size_t size);
71 static ssize_t write_pool_threads(struct file *file, char *buf, size_t size);
72 static ssize_t write_versions(struct file *file, char *buf, size_t size);
73 static ssize_t write_ports(struct file *file, char *buf, size_t size);
74 static ssize_t write_maxblksize(struct file *file, char *buf, size_t size);
75 static ssize_t write_maxconn(struct file *file, char *buf, size_t size);
76 #ifdef CONFIG_NFSD_V4
77 static ssize_t write_leasetime(struct file *file, char *buf, size_t size);
78 static ssize_t write_gracetime(struct file *file, char *buf, size_t size);
79 static ssize_t write_recoverydir(struct file *file, char *buf, size_t size);
80 static ssize_t write_v4_end_grace(struct file *file, char *buf, size_t size);
81 #endif
82 
83 static ssize_t (*const write_op[])(struct file *, char *, size_t) = {
84 	[NFSD_Fh] = write_filehandle,
85 	[NFSD_FO_UnlockIP] = write_unlock_ip,
86 	[NFSD_FO_UnlockFS] = write_unlock_fs,
87 	[NFSD_Threads] = write_threads,
88 	[NFSD_Pool_Threads] = write_pool_threads,
89 	[NFSD_Versions] = write_versions,
90 	[NFSD_Ports] = write_ports,
91 	[NFSD_MaxBlkSize] = write_maxblksize,
92 	[NFSD_MaxConnections] = write_maxconn,
93 #ifdef CONFIG_NFSD_V4
94 	[NFSD_Leasetime] = write_leasetime,
95 	[NFSD_Gracetime] = write_gracetime,
96 	[NFSD_RecoveryDir] = write_recoverydir,
97 	[NFSD_V4EndGrace] = write_v4_end_grace,
98 #endif
99 };
100 
101 static ssize_t nfsctl_transaction_write(struct file *file, const char __user *buf, size_t size, loff_t *pos)
102 {
103 	ino_t ino =  file_inode(file)->i_ino;
104 	char *data;
105 	ssize_t rv;
106 
107 	if (ino >= ARRAY_SIZE(write_op) || !write_op[ino])
108 		return -EINVAL;
109 
110 	data = simple_transaction_get(file, buf, size);
111 	if (IS_ERR(data))
112 		return PTR_ERR(data);
113 
114 	rv =  write_op[ino](file, data, size);
115 	if (rv >= 0) {
116 		simple_transaction_set(file, rv);
117 		rv = size;
118 	}
119 	return rv;
120 }
121 
122 static ssize_t nfsctl_transaction_read(struct file *file, char __user *buf, size_t size, loff_t *pos)
123 {
124 	if (! file->private_data) {
125 		/* An attempt to read a transaction file without writing
126 		 * causes a 0-byte write so that the file can return
127 		 * state information
128 		 */
129 		ssize_t rv = nfsctl_transaction_write(file, buf, 0, pos);
130 		if (rv < 0)
131 			return rv;
132 	}
133 	return simple_transaction_read(file, buf, size, pos);
134 }
135 
136 static const struct file_operations transaction_ops = {
137 	.write		= nfsctl_transaction_write,
138 	.read		= nfsctl_transaction_read,
139 	.release	= simple_transaction_release,
140 	.llseek		= default_llseek,
141 };
142 
143 static int exports_net_open(struct net *net, struct file *file)
144 {
145 	int err;
146 	struct seq_file *seq;
147 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
148 
149 	err = seq_open(file, &nfs_exports_op);
150 	if (err)
151 		return err;
152 
153 	seq = file->private_data;
154 	seq->private = nn->svc_export_cache;
155 	return 0;
156 }
157 
158 static int exports_proc_open(struct inode *inode, struct file *file)
159 {
160 	return exports_net_open(current->nsproxy->net_ns, file);
161 }
162 
163 static const struct proc_ops exports_proc_ops = {
164 	.proc_open	= exports_proc_open,
165 	.proc_read	= seq_read,
166 	.proc_lseek	= seq_lseek,
167 	.proc_release	= seq_release,
168 };
169 
170 static int exports_nfsd_open(struct inode *inode, struct file *file)
171 {
172 	return exports_net_open(inode->i_sb->s_fs_info, file);
173 }
174 
175 static const struct file_operations exports_nfsd_operations = {
176 	.open		= exports_nfsd_open,
177 	.read		= seq_read,
178 	.llseek		= seq_lseek,
179 	.release	= seq_release,
180 };
181 
182 static int export_features_show(struct seq_file *m, void *v)
183 {
184 	seq_printf(m, "0x%x 0x%x\n", NFSEXP_ALLFLAGS, NFSEXP_SECINFO_FLAGS);
185 	return 0;
186 }
187 
188 DEFINE_SHOW_ATTRIBUTE(export_features);
189 
190 #if defined(CONFIG_SUNRPC_GSS) || defined(CONFIG_SUNRPC_GSS_MODULE)
191 static int supported_enctypes_show(struct seq_file *m, void *v)
192 {
193 	seq_printf(m, KRB5_SUPPORTED_ENCTYPES);
194 	return 0;
195 }
196 
197 DEFINE_SHOW_ATTRIBUTE(supported_enctypes);
198 #endif /* CONFIG_SUNRPC_GSS or CONFIG_SUNRPC_GSS_MODULE */
199 
200 static const struct file_operations pool_stats_operations = {
201 	.open		= nfsd_pool_stats_open,
202 	.read		= seq_read,
203 	.llseek		= seq_lseek,
204 	.release	= nfsd_pool_stats_release,
205 };
206 
207 DEFINE_SHOW_ATTRIBUTE(nfsd_reply_cache_stats);
208 
209 DEFINE_SHOW_ATTRIBUTE(nfsd_file_cache_stats);
210 
211 /*----------------------------------------------------------------------------*/
212 /*
213  * payload - write methods
214  */
215 
216 static inline struct net *netns(struct file *file)
217 {
218 	return file_inode(file)->i_sb->s_fs_info;
219 }
220 
221 /*
222  * write_unlock_ip - Release all locks used by a client
223  *
224  * Experimental.
225  *
226  * Input:
227  *			buf:	'\n'-terminated C string containing a
228  *				presentation format IP address
229  *			size:	length of C string in @buf
230  * Output:
231  *	On success:	returns zero if all specified locks were released;
232  *			returns one if one or more locks were not released
233  *	On error:	return code is negative errno value
234  */
235 static ssize_t write_unlock_ip(struct file *file, char *buf, size_t size)
236 {
237 	struct sockaddr_storage address;
238 	struct sockaddr *sap = (struct sockaddr *)&address;
239 	size_t salen = sizeof(address);
240 	char *fo_path;
241 	struct net *net = netns(file);
242 
243 	/* sanity check */
244 	if (size == 0)
245 		return -EINVAL;
246 
247 	if (buf[size-1] != '\n')
248 		return -EINVAL;
249 
250 	fo_path = buf;
251 	if (qword_get(&buf, fo_path, size) < 0)
252 		return -EINVAL;
253 
254 	if (rpc_pton(net, fo_path, size, sap, salen) == 0)
255 		return -EINVAL;
256 
257 	return nlmsvc_unlock_all_by_ip(sap);
258 }
259 
260 /*
261  * write_unlock_fs - Release all locks on a local file system
262  *
263  * Experimental.
264  *
265  * Input:
266  *			buf:	'\n'-terminated C string containing the
267  *				absolute pathname of a local file system
268  *			size:	length of C string in @buf
269  * Output:
270  *	On success:	returns zero if all specified locks were released;
271  *			returns one if one or more locks were not released
272  *	On error:	return code is negative errno value
273  */
274 static ssize_t write_unlock_fs(struct file *file, char *buf, size_t size)
275 {
276 	struct path path;
277 	char *fo_path;
278 	int error;
279 
280 	/* sanity check */
281 	if (size == 0)
282 		return -EINVAL;
283 
284 	if (buf[size-1] != '\n')
285 		return -EINVAL;
286 
287 	fo_path = buf;
288 	if (qword_get(&buf, fo_path, size) < 0)
289 		return -EINVAL;
290 
291 	error = kern_path(fo_path, 0, &path);
292 	if (error)
293 		return error;
294 
295 	/*
296 	 * XXX: Needs better sanity checking.  Otherwise we could end up
297 	 * releasing locks on the wrong file system.
298 	 *
299 	 * For example:
300 	 * 1.  Does the path refer to a directory?
301 	 * 2.  Is that directory a mount point, or
302 	 * 3.  Is that directory the root of an exported file system?
303 	 */
304 	error = nlmsvc_unlock_all_by_sb(path.dentry->d_sb);
305 
306 	path_put(&path);
307 	return error;
308 }
309 
310 /*
311  * write_filehandle - Get a variable-length NFS file handle by path
312  *
313  * On input, the buffer contains a '\n'-terminated C string comprised of
314  * three alphanumeric words separated by whitespace.  The string may
315  * contain escape sequences.
316  *
317  * Input:
318  *			buf:
319  *				domain:		client domain name
320  *				path:		export pathname
321  *				maxsize:	numeric maximum size of
322  *						@buf
323  *			size:	length of C string in @buf
324  * Output:
325  *	On success:	passed-in buffer filled with '\n'-terminated C
326  *			string containing a ASCII hex text version
327  *			of the NFS file handle;
328  *			return code is the size in bytes of the string
329  *	On error:	return code is negative errno value
330  */
331 static ssize_t write_filehandle(struct file *file, char *buf, size_t size)
332 {
333 	char *dname, *path;
334 	int maxsize;
335 	char *mesg = buf;
336 	int len;
337 	struct auth_domain *dom;
338 	struct knfsd_fh fh;
339 
340 	if (size == 0)
341 		return -EINVAL;
342 
343 	if (buf[size-1] != '\n')
344 		return -EINVAL;
345 	buf[size-1] = 0;
346 
347 	dname = mesg;
348 	len = qword_get(&mesg, dname, size);
349 	if (len <= 0)
350 		return -EINVAL;
351 
352 	path = dname+len+1;
353 	len = qword_get(&mesg, path, size);
354 	if (len <= 0)
355 		return -EINVAL;
356 
357 	len = get_int(&mesg, &maxsize);
358 	if (len)
359 		return len;
360 
361 	if (maxsize < NFS_FHSIZE)
362 		return -EINVAL;
363 	maxsize = min(maxsize, NFS3_FHSIZE);
364 
365 	if (qword_get(&mesg, mesg, size)>0)
366 		return -EINVAL;
367 
368 	/* we have all the words, they are in buf.. */
369 	dom = unix_domain_find(dname);
370 	if (!dom)
371 		return -ENOMEM;
372 
373 	len = exp_rootfh(netns(file), dom, path, &fh,  maxsize);
374 	auth_domain_put(dom);
375 	if (len)
376 		return len;
377 
378 	mesg = buf;
379 	len = SIMPLE_TRANSACTION_LIMIT;
380 	qword_addhex(&mesg, &len, fh.fh_raw, fh.fh_size);
381 	mesg[-1] = '\n';
382 	return mesg - buf;
383 }
384 
385 /*
386  * write_threads - Start NFSD, or report the current number of running threads
387  *
388  * Input:
389  *			buf:		ignored
390  *			size:		zero
391  * Output:
392  *	On success:	passed-in buffer filled with '\n'-terminated C
393  *			string numeric value representing the number of
394  *			running NFSD threads;
395  *			return code is the size in bytes of the string
396  *	On error:	return code is zero
397  *
398  * OR
399  *
400  * Input:
401  *			buf:		C string containing an unsigned
402  *					integer value representing the
403  *					number of NFSD threads to start
404  *			size:		non-zero length of C string in @buf
405  * Output:
406  *	On success:	NFS service is started;
407  *			passed-in buffer filled with '\n'-terminated C
408  *			string numeric value representing the number of
409  *			running NFSD threads;
410  *			return code is the size in bytes of the string
411  *	On error:	return code is zero or a negative errno value
412  */
413 static ssize_t write_threads(struct file *file, char *buf, size_t size)
414 {
415 	char *mesg = buf;
416 	int rv;
417 	struct net *net = netns(file);
418 
419 	if (size > 0) {
420 		int newthreads;
421 		rv = get_int(&mesg, &newthreads);
422 		if (rv)
423 			return rv;
424 		if (newthreads < 0)
425 			return -EINVAL;
426 		rv = nfsd_svc(newthreads, net, file->f_cred);
427 		if (rv < 0)
428 			return rv;
429 	} else
430 		rv = nfsd_nrthreads(net);
431 
432 	return scnprintf(buf, SIMPLE_TRANSACTION_LIMIT, "%d\n", rv);
433 }
434 
435 /*
436  * write_pool_threads - Set or report the current number of threads per pool
437  *
438  * Input:
439  *			buf:		ignored
440  *			size:		zero
441  *
442  * OR
443  *
444  * Input:
445  * 			buf:		C string containing whitespace-
446  * 					separated unsigned integer values
447  *					representing the number of NFSD
448  *					threads to start in each pool
449  *			size:		non-zero length of C string in @buf
450  * Output:
451  *	On success:	passed-in buffer filled with '\n'-terminated C
452  *			string containing integer values representing the
453  *			number of NFSD threads in each pool;
454  *			return code is the size in bytes of the string
455  *	On error:	return code is zero or a negative errno value
456  */
457 static ssize_t write_pool_threads(struct file *file, char *buf, size_t size)
458 {
459 	/* if size > 0, look for an array of number of threads per node
460 	 * and apply them  then write out number of threads per node as reply
461 	 */
462 	char *mesg = buf;
463 	int i;
464 	int rv;
465 	int len;
466 	int npools;
467 	int *nthreads;
468 	struct net *net = netns(file);
469 
470 	mutex_lock(&nfsd_mutex);
471 	npools = nfsd_nrpools(net);
472 	if (npools == 0) {
473 		/*
474 		 * NFS is shut down.  The admin can start it by
475 		 * writing to the threads file but NOT the pool_threads
476 		 * file, sorry.  Report zero threads.
477 		 */
478 		mutex_unlock(&nfsd_mutex);
479 		strcpy(buf, "0\n");
480 		return strlen(buf);
481 	}
482 
483 	nthreads = kcalloc(npools, sizeof(int), GFP_KERNEL);
484 	rv = -ENOMEM;
485 	if (nthreads == NULL)
486 		goto out_free;
487 
488 	if (size > 0) {
489 		for (i = 0; i < npools; i++) {
490 			rv = get_int(&mesg, &nthreads[i]);
491 			if (rv == -ENOENT)
492 				break;		/* fewer numbers than pools */
493 			if (rv)
494 				goto out_free;	/* syntax error */
495 			rv = -EINVAL;
496 			if (nthreads[i] < 0)
497 				goto out_free;
498 		}
499 		rv = nfsd_set_nrthreads(i, nthreads, net);
500 		if (rv)
501 			goto out_free;
502 	}
503 
504 	rv = nfsd_get_nrthreads(npools, nthreads, net);
505 	if (rv)
506 		goto out_free;
507 
508 	mesg = buf;
509 	size = SIMPLE_TRANSACTION_LIMIT;
510 	for (i = 0; i < npools && size > 0; i++) {
511 		snprintf(mesg, size, "%d%c", nthreads[i], (i == npools-1 ? '\n' : ' '));
512 		len = strlen(mesg);
513 		size -= len;
514 		mesg += len;
515 	}
516 	rv = mesg - buf;
517 out_free:
518 	kfree(nthreads);
519 	mutex_unlock(&nfsd_mutex);
520 	return rv;
521 }
522 
523 static ssize_t
524 nfsd_print_version_support(struct nfsd_net *nn, char *buf, int remaining,
525 		const char *sep, unsigned vers, int minor)
526 {
527 	const char *format = minor < 0 ? "%s%c%u" : "%s%c%u.%u";
528 	bool supported = !!nfsd_vers(nn, vers, NFSD_TEST);
529 
530 	if (vers == 4 && minor >= 0 &&
531 	    !nfsd_minorversion(nn, minor, NFSD_TEST))
532 		supported = false;
533 	if (minor == 0 && supported)
534 		/*
535 		 * special case for backward compatability.
536 		 * +4.0 is never reported, it is implied by
537 		 * +4, unless -4.0 is present.
538 		 */
539 		return 0;
540 	return snprintf(buf, remaining, format, sep,
541 			supported ? '+' : '-', vers, minor);
542 }
543 
544 static ssize_t __write_versions(struct file *file, char *buf, size_t size)
545 {
546 	char *mesg = buf;
547 	char *vers, *minorp, sign;
548 	int len, num, remaining;
549 	ssize_t tlen = 0;
550 	char *sep;
551 	struct nfsd_net *nn = net_generic(netns(file), nfsd_net_id);
552 
553 	if (size>0) {
554 		if (nn->nfsd_serv)
555 			/* Cannot change versions without updating
556 			 * nn->nfsd_serv->sv_xdrsize, and reallocing
557 			 * rq_argp and rq_resp
558 			 */
559 			return -EBUSY;
560 		if (buf[size-1] != '\n')
561 			return -EINVAL;
562 		buf[size-1] = 0;
563 
564 		vers = mesg;
565 		len = qword_get(&mesg, vers, size);
566 		if (len <= 0) return -EINVAL;
567 		do {
568 			enum vers_op cmd;
569 			unsigned minor;
570 			sign = *vers;
571 			if (sign == '+' || sign == '-')
572 				num = simple_strtol((vers+1), &minorp, 0);
573 			else
574 				num = simple_strtol(vers, &minorp, 0);
575 			if (*minorp == '.') {
576 				if (num != 4)
577 					return -EINVAL;
578 				if (kstrtouint(minorp+1, 0, &minor) < 0)
579 					return -EINVAL;
580 			}
581 
582 			cmd = sign == '-' ? NFSD_CLEAR : NFSD_SET;
583 			switch(num) {
584 #ifdef CONFIG_NFSD_V2
585 			case 2:
586 #endif
587 			case 3:
588 				nfsd_vers(nn, num, cmd);
589 				break;
590 			case 4:
591 				if (*minorp == '.') {
592 					if (nfsd_minorversion(nn, minor, cmd) < 0)
593 						return -EINVAL;
594 				} else if ((cmd == NFSD_SET) != nfsd_vers(nn, num, NFSD_TEST)) {
595 					/*
596 					 * Either we have +4 and no minors are enabled,
597 					 * or we have -4 and at least one minor is enabled.
598 					 * In either case, propagate 'cmd' to all minors.
599 					 */
600 					minor = 0;
601 					while (nfsd_minorversion(nn, minor, cmd) >= 0)
602 						minor++;
603 				}
604 				break;
605 			default:
606 				/* Ignore requests to disable non-existent versions */
607 				if (cmd == NFSD_SET)
608 					return -EINVAL;
609 			}
610 			vers += len + 1;
611 		} while ((len = qword_get(&mesg, vers, size)) > 0);
612 		/* If all get turned off, turn them back on, as
613 		 * having no versions is BAD
614 		 */
615 		nfsd_reset_versions(nn);
616 	}
617 
618 	/* Now write current state into reply buffer */
619 	sep = "";
620 	remaining = SIMPLE_TRANSACTION_LIMIT;
621 	for (num=2 ; num <= 4 ; num++) {
622 		int minor;
623 		if (!nfsd_vers(nn, num, NFSD_AVAIL))
624 			continue;
625 
626 		minor = -1;
627 		do {
628 			len = nfsd_print_version_support(nn, buf, remaining,
629 					sep, num, minor);
630 			if (len >= remaining)
631 				goto out;
632 			remaining -= len;
633 			buf += len;
634 			tlen += len;
635 			minor++;
636 			if (len)
637 				sep = " ";
638 		} while (num == 4 && minor <= NFSD_SUPPORTED_MINOR_VERSION);
639 	}
640 out:
641 	len = snprintf(buf, remaining, "\n");
642 	if (len >= remaining)
643 		return -EINVAL;
644 	return tlen + len;
645 }
646 
647 /*
648  * write_versions - Set or report the available NFS protocol versions
649  *
650  * Input:
651  *			buf:		ignored
652  *			size:		zero
653  * Output:
654  *	On success:	passed-in buffer filled with '\n'-terminated C
655  *			string containing positive or negative integer
656  *			values representing the current status of each
657  *			protocol version;
658  *			return code is the size in bytes of the string
659  *	On error:	return code is zero or a negative errno value
660  *
661  * OR
662  *
663  * Input:
664  * 			buf:		C string containing whitespace-
665  * 					separated positive or negative
666  * 					integer values representing NFS
667  * 					protocol versions to enable ("+n")
668  * 					or disable ("-n")
669  *			size:		non-zero length of C string in @buf
670  * Output:
671  *	On success:	status of zero or more protocol versions has
672  *			been updated; passed-in buffer filled with
673  *			'\n'-terminated C string containing positive
674  *			or negative integer values representing the
675  *			current status of each protocol version;
676  *			return code is the size in bytes of the string
677  *	On error:	return code is zero or a negative errno value
678  */
679 static ssize_t write_versions(struct file *file, char *buf, size_t size)
680 {
681 	ssize_t rv;
682 
683 	mutex_lock(&nfsd_mutex);
684 	rv = __write_versions(file, buf, size);
685 	mutex_unlock(&nfsd_mutex);
686 	return rv;
687 }
688 
689 /*
690  * Zero-length write.  Return a list of NFSD's current listener
691  * transports.
692  */
693 static ssize_t __write_ports_names(char *buf, struct net *net)
694 {
695 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
696 
697 	if (nn->nfsd_serv == NULL)
698 		return 0;
699 	return svc_xprt_names(nn->nfsd_serv, buf, SIMPLE_TRANSACTION_LIMIT);
700 }
701 
702 /*
703  * A single 'fd' number was written, in which case it must be for
704  * a socket of a supported family/protocol, and we use it as an
705  * nfsd listener.
706  */
707 static ssize_t __write_ports_addfd(char *buf, struct net *net, const struct cred *cred)
708 {
709 	char *mesg = buf;
710 	int fd, err;
711 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
712 
713 	err = get_int(&mesg, &fd);
714 	if (err != 0 || fd < 0)
715 		return -EINVAL;
716 
717 	if (svc_alien_sock(net, fd)) {
718 		printk(KERN_ERR "%s: socket net is different to NFSd's one\n", __func__);
719 		return -EINVAL;
720 	}
721 
722 	err = nfsd_create_serv(net);
723 	if (err != 0)
724 		return err;
725 
726 	err = svc_addsock(nn->nfsd_serv, fd, buf, SIMPLE_TRANSACTION_LIMIT, cred);
727 
728 	if (err >= 0 &&
729 	    !nn->nfsd_serv->sv_nrthreads && !xchg(&nn->keep_active, 1))
730 		svc_get(nn->nfsd_serv);
731 
732 	nfsd_put(net);
733 	return err;
734 }
735 
736 /*
737  * A transport listener is added by writing it's transport name and
738  * a port number.
739  */
740 static ssize_t __write_ports_addxprt(char *buf, struct net *net, const struct cred *cred)
741 {
742 	char transport[16];
743 	struct svc_xprt *xprt;
744 	int port, err;
745 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
746 
747 	if (sscanf(buf, "%15s %5u", transport, &port) != 2)
748 		return -EINVAL;
749 
750 	if (port < 1 || port > USHRT_MAX)
751 		return -EINVAL;
752 
753 	err = nfsd_create_serv(net);
754 	if (err != 0)
755 		return err;
756 
757 	err = svc_xprt_create(nn->nfsd_serv, transport, net,
758 			      PF_INET, port, SVC_SOCK_ANONYMOUS, cred);
759 	if (err < 0)
760 		goto out_err;
761 
762 	err = svc_xprt_create(nn->nfsd_serv, transport, net,
763 			      PF_INET6, port, SVC_SOCK_ANONYMOUS, cred);
764 	if (err < 0 && err != -EAFNOSUPPORT)
765 		goto out_close;
766 
767 	if (!nn->nfsd_serv->sv_nrthreads && !xchg(&nn->keep_active, 1))
768 		svc_get(nn->nfsd_serv);
769 
770 	nfsd_put(net);
771 	return 0;
772 out_close:
773 	xprt = svc_find_xprt(nn->nfsd_serv, transport, net, PF_INET, port);
774 	if (xprt != NULL) {
775 		svc_xprt_close(xprt);
776 		svc_xprt_put(xprt);
777 	}
778 out_err:
779 	nfsd_put(net);
780 	return err;
781 }
782 
783 static ssize_t __write_ports(struct file *file, char *buf, size_t size,
784 			     struct net *net)
785 {
786 	if (size == 0)
787 		return __write_ports_names(buf, net);
788 
789 	if (isdigit(buf[0]))
790 		return __write_ports_addfd(buf, net, file->f_cred);
791 
792 	if (isalpha(buf[0]))
793 		return __write_ports_addxprt(buf, net, file->f_cred);
794 
795 	return -EINVAL;
796 }
797 
798 /*
799  * write_ports - Pass a socket file descriptor or transport name to listen on
800  *
801  * Input:
802  *			buf:		ignored
803  *			size:		zero
804  * Output:
805  *	On success:	passed-in buffer filled with a '\n'-terminated C
806  *			string containing a whitespace-separated list of
807  *			named NFSD listeners;
808  *			return code is the size in bytes of the string
809  *	On error:	return code is zero or a negative errno value
810  *
811  * OR
812  *
813  * Input:
814  *			buf:		C string containing an unsigned
815  *					integer value representing a bound
816  *					but unconnected socket that is to be
817  *					used as an NFSD listener; listen(3)
818  *					must be called for a SOCK_STREAM
819  *					socket, otherwise it is ignored
820  *			size:		non-zero length of C string in @buf
821  * Output:
822  *	On success:	NFS service is started;
823  *			passed-in buffer filled with a '\n'-terminated C
824  *			string containing a unique alphanumeric name of
825  *			the listener;
826  *			return code is the size in bytes of the string
827  *	On error:	return code is a negative errno value
828  *
829  * OR
830  *
831  * Input:
832  *			buf:		C string containing a transport
833  *					name and an unsigned integer value
834  *					representing the port to listen on,
835  *					separated by whitespace
836  *			size:		non-zero length of C string in @buf
837  * Output:
838  *	On success:	returns zero; NFS service is started
839  *	On error:	return code is a negative errno value
840  */
841 static ssize_t write_ports(struct file *file, char *buf, size_t size)
842 {
843 	ssize_t rv;
844 
845 	mutex_lock(&nfsd_mutex);
846 	rv = __write_ports(file, buf, size, netns(file));
847 	mutex_unlock(&nfsd_mutex);
848 	return rv;
849 }
850 
851 
852 int nfsd_max_blksize;
853 
854 /*
855  * write_maxblksize - Set or report the current NFS blksize
856  *
857  * Input:
858  *			buf:		ignored
859  *			size:		zero
860  *
861  * OR
862  *
863  * Input:
864  * 			buf:		C string containing an unsigned
865  * 					integer value representing the new
866  * 					NFS blksize
867  *			size:		non-zero length of C string in @buf
868  * Output:
869  *	On success:	passed-in buffer filled with '\n'-terminated C string
870  *			containing numeric value of the current NFS blksize
871  *			setting;
872  *			return code is the size in bytes of the string
873  *	On error:	return code is zero or a negative errno value
874  */
875 static ssize_t write_maxblksize(struct file *file, char *buf, size_t size)
876 {
877 	char *mesg = buf;
878 	struct nfsd_net *nn = net_generic(netns(file), nfsd_net_id);
879 
880 	if (size > 0) {
881 		int bsize;
882 		int rv = get_int(&mesg, &bsize);
883 		if (rv)
884 			return rv;
885 		/* force bsize into allowed range and
886 		 * required alignment.
887 		 */
888 		bsize = max_t(int, bsize, 1024);
889 		bsize = min_t(int, bsize, NFSSVC_MAXBLKSIZE);
890 		bsize &= ~(1024-1);
891 		mutex_lock(&nfsd_mutex);
892 		if (nn->nfsd_serv) {
893 			mutex_unlock(&nfsd_mutex);
894 			return -EBUSY;
895 		}
896 		nfsd_max_blksize = bsize;
897 		mutex_unlock(&nfsd_mutex);
898 	}
899 
900 	return scnprintf(buf, SIMPLE_TRANSACTION_LIMIT, "%d\n",
901 							nfsd_max_blksize);
902 }
903 
904 /*
905  * write_maxconn - Set or report the current max number of connections
906  *
907  * Input:
908  *			buf:		ignored
909  *			size:		zero
910  * OR
911  *
912  * Input:
913  * 			buf:		C string containing an unsigned
914  * 					integer value representing the new
915  * 					number of max connections
916  *			size:		non-zero length of C string in @buf
917  * Output:
918  *	On success:	passed-in buffer filled with '\n'-terminated C string
919  *			containing numeric value of max_connections setting
920  *			for this net namespace;
921  *			return code is the size in bytes of the string
922  *	On error:	return code is zero or a negative errno value
923  */
924 static ssize_t write_maxconn(struct file *file, char *buf, size_t size)
925 {
926 	char *mesg = buf;
927 	struct nfsd_net *nn = net_generic(netns(file), nfsd_net_id);
928 	unsigned int maxconn = nn->max_connections;
929 
930 	if (size > 0) {
931 		int rv = get_uint(&mesg, &maxconn);
932 
933 		if (rv)
934 			return rv;
935 		nn->max_connections = maxconn;
936 	}
937 
938 	return scnprintf(buf, SIMPLE_TRANSACTION_LIMIT, "%u\n", maxconn);
939 }
940 
941 #ifdef CONFIG_NFSD_V4
942 static ssize_t __nfsd4_write_time(struct file *file, char *buf, size_t size,
943 				  time64_t *time, struct nfsd_net *nn)
944 {
945 	char *mesg = buf;
946 	int rv, i;
947 
948 	if (size > 0) {
949 		if (nn->nfsd_serv)
950 			return -EBUSY;
951 		rv = get_int(&mesg, &i);
952 		if (rv)
953 			return rv;
954 		/*
955 		 * Some sanity checking.  We don't have a reason for
956 		 * these particular numbers, but problems with the
957 		 * extremes are:
958 		 *	- Too short: the briefest network outage may
959 		 *	  cause clients to lose all their locks.  Also,
960 		 *	  the frequent polling may be wasteful.
961 		 *	- Too long: do you really want reboot recovery
962 		 *	  to take more than an hour?  Or to make other
963 		 *	  clients wait an hour before being able to
964 		 *	  revoke a dead client's locks?
965 		 */
966 		if (i < 10 || i > 3600)
967 			return -EINVAL;
968 		*time = i;
969 	}
970 
971 	return scnprintf(buf, SIMPLE_TRANSACTION_LIMIT, "%lld\n", *time);
972 }
973 
974 static ssize_t nfsd4_write_time(struct file *file, char *buf, size_t size,
975 				time64_t *time, struct nfsd_net *nn)
976 {
977 	ssize_t rv;
978 
979 	mutex_lock(&nfsd_mutex);
980 	rv = __nfsd4_write_time(file, buf, size, time, nn);
981 	mutex_unlock(&nfsd_mutex);
982 	return rv;
983 }
984 
985 /*
986  * write_leasetime - Set or report the current NFSv4 lease time
987  *
988  * Input:
989  *			buf:		ignored
990  *			size:		zero
991  *
992  * OR
993  *
994  * Input:
995  *			buf:		C string containing an unsigned
996  *					integer value representing the new
997  *					NFSv4 lease expiry time
998  *			size:		non-zero length of C string in @buf
999  * Output:
1000  *	On success:	passed-in buffer filled with '\n'-terminated C
1001  *			string containing unsigned integer value of the
1002  *			current lease expiry time;
1003  *			return code is the size in bytes of the string
1004  *	On error:	return code is zero or a negative errno value
1005  */
1006 static ssize_t write_leasetime(struct file *file, char *buf, size_t size)
1007 {
1008 	struct nfsd_net *nn = net_generic(netns(file), nfsd_net_id);
1009 	return nfsd4_write_time(file, buf, size, &nn->nfsd4_lease, nn);
1010 }
1011 
1012 /*
1013  * write_gracetime - Set or report current NFSv4 grace period time
1014  *
1015  * As above, but sets the time of the NFSv4 grace period.
1016  *
1017  * Note this should never be set to less than the *previous*
1018  * lease-period time, but we don't try to enforce this.  (In the common
1019  * case (a new boot), we don't know what the previous lease time was
1020  * anyway.)
1021  */
1022 static ssize_t write_gracetime(struct file *file, char *buf, size_t size)
1023 {
1024 	struct nfsd_net *nn = net_generic(netns(file), nfsd_net_id);
1025 	return nfsd4_write_time(file, buf, size, &nn->nfsd4_grace, nn);
1026 }
1027 
1028 static ssize_t __write_recoverydir(struct file *file, char *buf, size_t size,
1029 				   struct nfsd_net *nn)
1030 {
1031 	char *mesg = buf;
1032 	char *recdir;
1033 	int len, status;
1034 
1035 	if (size > 0) {
1036 		if (nn->nfsd_serv)
1037 			return -EBUSY;
1038 		if (size > PATH_MAX || buf[size-1] != '\n')
1039 			return -EINVAL;
1040 		buf[size-1] = 0;
1041 
1042 		recdir = mesg;
1043 		len = qword_get(&mesg, recdir, size);
1044 		if (len <= 0)
1045 			return -EINVAL;
1046 
1047 		status = nfs4_reset_recoverydir(recdir);
1048 		if (status)
1049 			return status;
1050 	}
1051 
1052 	return scnprintf(buf, SIMPLE_TRANSACTION_LIMIT, "%s\n",
1053 							nfs4_recoverydir());
1054 }
1055 
1056 /*
1057  * write_recoverydir - Set or report the pathname of the recovery directory
1058  *
1059  * Input:
1060  *			buf:		ignored
1061  *			size:		zero
1062  *
1063  * OR
1064  *
1065  * Input:
1066  *			buf:		C string containing the pathname
1067  *					of the directory on a local file
1068  *					system containing permanent NFSv4
1069  *					recovery data
1070  *			size:		non-zero length of C string in @buf
1071  * Output:
1072  *	On success:	passed-in buffer filled with '\n'-terminated C string
1073  *			containing the current recovery pathname setting;
1074  *			return code is the size in bytes of the string
1075  *	On error:	return code is zero or a negative errno value
1076  */
1077 static ssize_t write_recoverydir(struct file *file, char *buf, size_t size)
1078 {
1079 	ssize_t rv;
1080 	struct nfsd_net *nn = net_generic(netns(file), nfsd_net_id);
1081 
1082 	mutex_lock(&nfsd_mutex);
1083 	rv = __write_recoverydir(file, buf, size, nn);
1084 	mutex_unlock(&nfsd_mutex);
1085 	return rv;
1086 }
1087 
1088 /*
1089  * write_v4_end_grace - release grace period for nfsd's v4.x lock manager
1090  *
1091  * Input:
1092  *			buf:		ignored
1093  *			size:		zero
1094  * OR
1095  *
1096  * Input:
1097  * 			buf:		any value
1098  *			size:		non-zero length of C string in @buf
1099  * Output:
1100  *			passed-in buffer filled with "Y" or "N" with a newline
1101  *			and NULL-terminated C string. This indicates whether
1102  *			the grace period has ended in the current net
1103  *			namespace. Return code is the size in bytes of the
1104  *			string. Writing a string that starts with 'Y', 'y', or
1105  *			'1' to the file will end the grace period for nfsd's v4
1106  *			lock manager.
1107  */
1108 static ssize_t write_v4_end_grace(struct file *file, char *buf, size_t size)
1109 {
1110 	struct nfsd_net *nn = net_generic(netns(file), nfsd_net_id);
1111 
1112 	if (size > 0) {
1113 		switch(buf[0]) {
1114 		case 'Y':
1115 		case 'y':
1116 		case '1':
1117 			if (!nn->nfsd_serv)
1118 				return -EBUSY;
1119 			nfsd4_end_grace(nn);
1120 			break;
1121 		default:
1122 			return -EINVAL;
1123 		}
1124 	}
1125 
1126 	return scnprintf(buf, SIMPLE_TRANSACTION_LIMIT, "%c\n",
1127 			 nn->grace_ended ? 'Y' : 'N');
1128 }
1129 
1130 #endif
1131 
1132 /*----------------------------------------------------------------------------*/
1133 /*
1134  *	populating the filesystem.
1135  */
1136 
1137 /* Basically copying rpc_get_inode. */
1138 static struct inode *nfsd_get_inode(struct super_block *sb, umode_t mode)
1139 {
1140 	struct inode *inode = new_inode(sb);
1141 	if (!inode)
1142 		return NULL;
1143 	/* Following advice from simple_fill_super documentation: */
1144 	inode->i_ino = iunique(sb, NFSD_MaxReserved);
1145 	inode->i_mode = mode;
1146 	inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
1147 	switch (mode & S_IFMT) {
1148 	case S_IFDIR:
1149 		inode->i_fop = &simple_dir_operations;
1150 		inode->i_op = &simple_dir_inode_operations;
1151 		inc_nlink(inode);
1152 		break;
1153 	default:
1154 		break;
1155 	}
1156 	return inode;
1157 }
1158 
1159 static int __nfsd_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode, struct nfsdfs_client *ncl)
1160 {
1161 	struct inode *inode;
1162 
1163 	inode = nfsd_get_inode(dir->i_sb, mode);
1164 	if (!inode)
1165 		return -ENOMEM;
1166 	if (ncl) {
1167 		inode->i_private = ncl;
1168 		kref_get(&ncl->cl_ref);
1169 	}
1170 	d_add(dentry, inode);
1171 	inc_nlink(dir);
1172 	fsnotify_mkdir(dir, dentry);
1173 	return 0;
1174 }
1175 
1176 static struct dentry *nfsd_mkdir(struct dentry *parent, struct nfsdfs_client *ncl, char *name)
1177 {
1178 	struct inode *dir = parent->d_inode;
1179 	struct dentry *dentry;
1180 	int ret = -ENOMEM;
1181 
1182 	inode_lock(dir);
1183 	dentry = d_alloc_name(parent, name);
1184 	if (!dentry)
1185 		goto out_err;
1186 	ret = __nfsd_mkdir(d_inode(parent), dentry, S_IFDIR | 0600, ncl);
1187 	if (ret)
1188 		goto out_err;
1189 out:
1190 	inode_unlock(dir);
1191 	return dentry;
1192 out_err:
1193 	dput(dentry);
1194 	dentry = ERR_PTR(ret);
1195 	goto out;
1196 }
1197 
1198 static void clear_ncl(struct inode *inode)
1199 {
1200 	struct nfsdfs_client *ncl = inode->i_private;
1201 
1202 	inode->i_private = NULL;
1203 	kref_put(&ncl->cl_ref, ncl->cl_release);
1204 }
1205 
1206 static struct nfsdfs_client *__get_nfsdfs_client(struct inode *inode)
1207 {
1208 	struct nfsdfs_client *nc = inode->i_private;
1209 
1210 	if (nc)
1211 		kref_get(&nc->cl_ref);
1212 	return nc;
1213 }
1214 
1215 struct nfsdfs_client *get_nfsdfs_client(struct inode *inode)
1216 {
1217 	struct nfsdfs_client *nc;
1218 
1219 	inode_lock_shared(inode);
1220 	nc = __get_nfsdfs_client(inode);
1221 	inode_unlock_shared(inode);
1222 	return nc;
1223 }
1224 /* from __rpc_unlink */
1225 static void nfsdfs_remove_file(struct inode *dir, struct dentry *dentry)
1226 {
1227 	int ret;
1228 
1229 	clear_ncl(d_inode(dentry));
1230 	dget(dentry);
1231 	ret = simple_unlink(dir, dentry);
1232 	d_drop(dentry);
1233 	fsnotify_unlink(dir, dentry);
1234 	dput(dentry);
1235 	WARN_ON_ONCE(ret);
1236 }
1237 
1238 static void nfsdfs_remove_files(struct dentry *root)
1239 {
1240 	struct dentry *dentry, *tmp;
1241 
1242 	list_for_each_entry_safe(dentry, tmp, &root->d_subdirs, d_child) {
1243 		if (!simple_positive(dentry)) {
1244 			WARN_ON_ONCE(1); /* I think this can't happen? */
1245 			continue;
1246 		}
1247 		nfsdfs_remove_file(d_inode(root), dentry);
1248 	}
1249 }
1250 
1251 /* XXX: cut'n'paste from simple_fill_super; figure out if we could share
1252  * code instead. */
1253 static  int nfsdfs_create_files(struct dentry *root,
1254 				const struct tree_descr *files,
1255 				struct dentry **fdentries)
1256 {
1257 	struct inode *dir = d_inode(root);
1258 	struct inode *inode;
1259 	struct dentry *dentry;
1260 	int i;
1261 
1262 	inode_lock(dir);
1263 	for (i = 0; files->name && files->name[0]; i++, files++) {
1264 		dentry = d_alloc_name(root, files->name);
1265 		if (!dentry)
1266 			goto out;
1267 		inode = nfsd_get_inode(d_inode(root)->i_sb,
1268 					S_IFREG | files->mode);
1269 		if (!inode) {
1270 			dput(dentry);
1271 			goto out;
1272 		}
1273 		inode->i_fop = files->ops;
1274 		inode->i_private = __get_nfsdfs_client(dir);
1275 		d_add(dentry, inode);
1276 		fsnotify_create(dir, dentry);
1277 		if (fdentries)
1278 			fdentries[i] = dentry;
1279 	}
1280 	inode_unlock(dir);
1281 	return 0;
1282 out:
1283 	nfsdfs_remove_files(root);
1284 	inode_unlock(dir);
1285 	return -ENOMEM;
1286 }
1287 
1288 /* on success, returns positive number unique to that client. */
1289 struct dentry *nfsd_client_mkdir(struct nfsd_net *nn,
1290 				 struct nfsdfs_client *ncl, u32 id,
1291 				 const struct tree_descr *files,
1292 				 struct dentry **fdentries)
1293 {
1294 	struct dentry *dentry;
1295 	char name[11];
1296 	int ret;
1297 
1298 	sprintf(name, "%u", id);
1299 
1300 	dentry = nfsd_mkdir(nn->nfsd_client_dir, ncl, name);
1301 	if (IS_ERR(dentry)) /* XXX: tossing errors? */
1302 		return NULL;
1303 	ret = nfsdfs_create_files(dentry, files, fdentries);
1304 	if (ret) {
1305 		nfsd_client_rmdir(dentry);
1306 		return NULL;
1307 	}
1308 	return dentry;
1309 }
1310 
1311 /* Taken from __rpc_rmdir: */
1312 void nfsd_client_rmdir(struct dentry *dentry)
1313 {
1314 	struct inode *dir = d_inode(dentry->d_parent);
1315 	struct inode *inode = d_inode(dentry);
1316 	int ret;
1317 
1318 	inode_lock(dir);
1319 	nfsdfs_remove_files(dentry);
1320 	clear_ncl(inode);
1321 	dget(dentry);
1322 	ret = simple_rmdir(dir, dentry);
1323 	WARN_ON_ONCE(ret);
1324 	d_drop(dentry);
1325 	fsnotify_rmdir(dir, dentry);
1326 	dput(dentry);
1327 	inode_unlock(dir);
1328 }
1329 
1330 static int nfsd_fill_super(struct super_block *sb, struct fs_context *fc)
1331 {
1332 	struct nfsd_net *nn = net_generic(current->nsproxy->net_ns,
1333 							nfsd_net_id);
1334 	struct dentry *dentry;
1335 	int ret;
1336 
1337 	static const struct tree_descr nfsd_files[] = {
1338 		[NFSD_List] = {"exports", &exports_nfsd_operations, S_IRUGO},
1339 		/* Per-export io stats use same ops as exports file */
1340 		[NFSD_Export_Stats] = {"export_stats", &exports_nfsd_operations, S_IRUGO},
1341 		[NFSD_Export_features] = {"export_features",
1342 					&export_features_fops, S_IRUGO},
1343 		[NFSD_FO_UnlockIP] = {"unlock_ip",
1344 					&transaction_ops, S_IWUSR|S_IRUSR},
1345 		[NFSD_FO_UnlockFS] = {"unlock_filesystem",
1346 					&transaction_ops, S_IWUSR|S_IRUSR},
1347 		[NFSD_Fh] = {"filehandle", &transaction_ops, S_IWUSR|S_IRUSR},
1348 		[NFSD_Threads] = {"threads", &transaction_ops, S_IWUSR|S_IRUSR},
1349 		[NFSD_Pool_Threads] = {"pool_threads", &transaction_ops, S_IWUSR|S_IRUSR},
1350 		[NFSD_Pool_Stats] = {"pool_stats", &pool_stats_operations, S_IRUGO},
1351 		[NFSD_Reply_Cache_Stats] = {"reply_cache_stats",
1352 					&nfsd_reply_cache_stats_fops, S_IRUGO},
1353 		[NFSD_Versions] = {"versions", &transaction_ops, S_IWUSR|S_IRUSR},
1354 		[NFSD_Ports] = {"portlist", &transaction_ops, S_IWUSR|S_IRUGO},
1355 		[NFSD_MaxBlkSize] = {"max_block_size", &transaction_ops, S_IWUSR|S_IRUGO},
1356 		[NFSD_MaxConnections] = {"max_connections", &transaction_ops, S_IWUSR|S_IRUGO},
1357 		[NFSD_Filecache] = {"filecache", &nfsd_file_cache_stats_fops, S_IRUGO},
1358 #if defined(CONFIG_SUNRPC_GSS) || defined(CONFIG_SUNRPC_GSS_MODULE)
1359 		[NFSD_SupportedEnctypes] = {"supported_krb5_enctypes",
1360 					&supported_enctypes_fops, S_IRUGO},
1361 #endif /* CONFIG_SUNRPC_GSS or CONFIG_SUNRPC_GSS_MODULE */
1362 #ifdef CONFIG_NFSD_V4
1363 		[NFSD_Leasetime] = {"nfsv4leasetime", &transaction_ops, S_IWUSR|S_IRUSR},
1364 		[NFSD_Gracetime] = {"nfsv4gracetime", &transaction_ops, S_IWUSR|S_IRUSR},
1365 		[NFSD_RecoveryDir] = {"nfsv4recoverydir", &transaction_ops, S_IWUSR|S_IRUSR},
1366 		[NFSD_V4EndGrace] = {"v4_end_grace", &transaction_ops, S_IWUSR|S_IRUGO},
1367 #endif
1368 		/* last one */ {""}
1369 	};
1370 
1371 	ret = simple_fill_super(sb, 0x6e667364, nfsd_files);
1372 	if (ret)
1373 		return ret;
1374 	dentry = nfsd_mkdir(sb->s_root, NULL, "clients");
1375 	if (IS_ERR(dentry))
1376 		return PTR_ERR(dentry);
1377 	nn->nfsd_client_dir = dentry;
1378 	return 0;
1379 }
1380 
1381 static int nfsd_fs_get_tree(struct fs_context *fc)
1382 {
1383 	return get_tree_keyed(fc, nfsd_fill_super, get_net(fc->net_ns));
1384 }
1385 
1386 static void nfsd_fs_free_fc(struct fs_context *fc)
1387 {
1388 	if (fc->s_fs_info)
1389 		put_net(fc->s_fs_info);
1390 }
1391 
1392 static const struct fs_context_operations nfsd_fs_context_ops = {
1393 	.free		= nfsd_fs_free_fc,
1394 	.get_tree	= nfsd_fs_get_tree,
1395 };
1396 
1397 static int nfsd_init_fs_context(struct fs_context *fc)
1398 {
1399 	put_user_ns(fc->user_ns);
1400 	fc->user_ns = get_user_ns(fc->net_ns->user_ns);
1401 	fc->ops = &nfsd_fs_context_ops;
1402 	return 0;
1403 }
1404 
1405 static void nfsd_umount(struct super_block *sb)
1406 {
1407 	struct net *net = sb->s_fs_info;
1408 
1409 	nfsd_shutdown_threads(net);
1410 
1411 	kill_litter_super(sb);
1412 	put_net(net);
1413 }
1414 
1415 static struct file_system_type nfsd_fs_type = {
1416 	.owner		= THIS_MODULE,
1417 	.name		= "nfsd",
1418 	.init_fs_context = nfsd_init_fs_context,
1419 	.kill_sb	= nfsd_umount,
1420 };
1421 MODULE_ALIAS_FS("nfsd");
1422 
1423 #ifdef CONFIG_PROC_FS
1424 static int create_proc_exports_entry(void)
1425 {
1426 	struct proc_dir_entry *entry;
1427 
1428 	entry = proc_mkdir("fs/nfs", NULL);
1429 	if (!entry)
1430 		return -ENOMEM;
1431 	entry = proc_create("exports", 0, entry, &exports_proc_ops);
1432 	if (!entry) {
1433 		remove_proc_entry("fs/nfs", NULL);
1434 		return -ENOMEM;
1435 	}
1436 	return 0;
1437 }
1438 #else /* CONFIG_PROC_FS */
1439 static int create_proc_exports_entry(void)
1440 {
1441 	return 0;
1442 }
1443 #endif
1444 
1445 unsigned int nfsd_net_id;
1446 
1447 static __net_init int nfsd_init_net(struct net *net)
1448 {
1449 	int retval;
1450 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1451 
1452 	retval = nfsd_export_init(net);
1453 	if (retval)
1454 		goto out_export_error;
1455 	retval = nfsd_idmap_init(net);
1456 	if (retval)
1457 		goto out_idmap_error;
1458 	nn->nfsd_versions = NULL;
1459 	nn->nfsd4_minorversions = NULL;
1460 	retval = nfsd4_init_leases_net(nn);
1461 	if (retval)
1462 		goto out_drc_error;
1463 	retval = nfsd_reply_cache_init(nn);
1464 	if (retval)
1465 		goto out_cache_error;
1466 	get_random_bytes(&nn->siphash_key, sizeof(nn->siphash_key));
1467 	seqlock_init(&nn->writeverf_lock);
1468 
1469 	return 0;
1470 
1471 out_cache_error:
1472 	nfsd4_leases_net_shutdown(nn);
1473 out_drc_error:
1474 	nfsd_idmap_shutdown(net);
1475 out_idmap_error:
1476 	nfsd_export_shutdown(net);
1477 out_export_error:
1478 	return retval;
1479 }
1480 
1481 static __net_exit void nfsd_exit_net(struct net *net)
1482 {
1483 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1484 
1485 	nfsd_reply_cache_shutdown(nn);
1486 	nfsd_idmap_shutdown(net);
1487 	nfsd_export_shutdown(net);
1488 	nfsd_netns_free_versions(net_generic(net, nfsd_net_id));
1489 	nfsd4_leases_net_shutdown(nn);
1490 }
1491 
1492 static struct pernet_operations nfsd_net_ops = {
1493 	.init = nfsd_init_net,
1494 	.exit = nfsd_exit_net,
1495 	.id   = &nfsd_net_id,
1496 	.size = sizeof(struct nfsd_net),
1497 };
1498 
1499 static int __init init_nfsd(void)
1500 {
1501 	int retval;
1502 
1503 	retval = nfsd4_init_slabs();
1504 	if (retval)
1505 		return retval;
1506 	retval = nfsd4_init_pnfs();
1507 	if (retval)
1508 		goto out_free_slabs;
1509 	retval = nfsd_stat_init();	/* Statistics */
1510 	if (retval)
1511 		goto out_free_pnfs;
1512 	retval = nfsd_drc_slab_create();
1513 	if (retval)
1514 		goto out_free_stat;
1515 	nfsd_lockd_init();	/* lockd->nfsd callbacks */
1516 	retval = create_proc_exports_entry();
1517 	if (retval)
1518 		goto out_free_lockd;
1519 	retval = register_pernet_subsys(&nfsd_net_ops);
1520 	if (retval < 0)
1521 		goto out_free_exports;
1522 	retval = register_cld_notifier();
1523 	if (retval)
1524 		goto out_free_subsys;
1525 	retval = nfsd4_create_laundry_wq();
1526 	if (retval)
1527 		goto out_free_cld;
1528 	retval = register_filesystem(&nfsd_fs_type);
1529 	if (retval)
1530 		goto out_free_all;
1531 	return 0;
1532 out_free_all:
1533 	nfsd4_destroy_laundry_wq();
1534 out_free_cld:
1535 	unregister_cld_notifier();
1536 out_free_subsys:
1537 	unregister_pernet_subsys(&nfsd_net_ops);
1538 out_free_exports:
1539 	remove_proc_entry("fs/nfs/exports", NULL);
1540 	remove_proc_entry("fs/nfs", NULL);
1541 out_free_lockd:
1542 	nfsd_lockd_shutdown();
1543 	nfsd_drc_slab_free();
1544 out_free_stat:
1545 	nfsd_stat_shutdown();
1546 out_free_pnfs:
1547 	nfsd4_exit_pnfs();
1548 out_free_slabs:
1549 	nfsd4_free_slabs();
1550 	return retval;
1551 }
1552 
1553 static void __exit exit_nfsd(void)
1554 {
1555 	unregister_filesystem(&nfsd_fs_type);
1556 	nfsd4_destroy_laundry_wq();
1557 	unregister_cld_notifier();
1558 	unregister_pernet_subsys(&nfsd_net_ops);
1559 	nfsd_drc_slab_free();
1560 	remove_proc_entry("fs/nfs/exports", NULL);
1561 	remove_proc_entry("fs/nfs", NULL);
1562 	nfsd_stat_shutdown();
1563 	nfsd_lockd_shutdown();
1564 	nfsd4_free_slabs();
1565 	nfsd4_exit_pnfs();
1566 }
1567 
1568 MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>");
1569 MODULE_LICENSE("GPL");
1570 module_init(init_nfsd)
1571 module_exit(exit_nfsd)
1572