xref: /linux/fs/nfsd/nfsctl.c (revision 5f346a6e5970229c19c059e8fa62c3dbdde56e7b)
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/rpc_pipe_fs.h>
18 #include <linux/module.h>
19 #include <linux/fsnotify.h>
20 
21 #include "idmap.h"
22 #include "nfsd.h"
23 #include "cache.h"
24 #include "state.h"
25 #include "netns.h"
26 #include "pnfs.h"
27 #include "filecache.h"
28 #include "trace.h"
29 #include "netlink.h"
30 
31 /*
32  *	We have a single directory with several nodes in it.
33  */
34 enum {
35 	NFSD_Root = 1,
36 	NFSD_List,
37 	NFSD_Export_Stats,
38 	NFSD_Export_features,
39 	NFSD_Fh,
40 	NFSD_FO_UnlockIP,
41 	NFSD_FO_UnlockFS,
42 	NFSD_Threads,
43 	NFSD_Pool_Threads,
44 	NFSD_Pool_Stats,
45 	NFSD_Reply_Cache_Stats,
46 	NFSD_Versions,
47 	NFSD_Ports,
48 	NFSD_MaxBlkSize,
49 	NFSD_MaxConnections,
50 	NFSD_Filecache,
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 		return rv;
117 
118 	simple_transaction_set(file, rv);
119 	return size;
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_nfsd_open(struct inode *inode, struct file *file)
159 {
160 	return exports_net_open(inode->i_sb->s_fs_info, file);
161 }
162 
163 static const struct file_operations exports_nfsd_operations = {
164 	.open		= exports_nfsd_open,
165 	.read		= seq_read,
166 	.llseek		= seq_lseek,
167 	.release	= seq_release,
168 };
169 
170 static int export_features_show(struct seq_file *m, void *v)
171 {
172 	seq_printf(m, "0x%x 0x%x\n", NFSEXP_ALLFLAGS, NFSEXP_SECINFO_FLAGS);
173 	return 0;
174 }
175 
176 DEFINE_SHOW_ATTRIBUTE(export_features);
177 
178 static const struct file_operations pool_stats_operations = {
179 	.open		= nfsd_pool_stats_open,
180 	.read		= seq_read,
181 	.llseek		= seq_lseek,
182 	.release	= nfsd_pool_stats_release,
183 };
184 
185 DEFINE_SHOW_ATTRIBUTE(nfsd_reply_cache_stats);
186 
187 DEFINE_SHOW_ATTRIBUTE(nfsd_file_cache_stats);
188 
189 /*----------------------------------------------------------------------------*/
190 /*
191  * payload - write methods
192  */
193 
194 static inline struct net *netns(struct file *file)
195 {
196 	return file_inode(file)->i_sb->s_fs_info;
197 }
198 
199 /*
200  * write_unlock_ip - Release all locks used by a client
201  *
202  * Experimental.
203  *
204  * Input:
205  *			buf:	'\n'-terminated C string containing a
206  *				presentation format IP address
207  *			size:	length of C string in @buf
208  * Output:
209  *	On success:	returns zero if all specified locks were released;
210  *			returns one if one or more locks were not released
211  *	On error:	return code is negative errno value
212  */
213 static ssize_t write_unlock_ip(struct file *file, char *buf, size_t size)
214 {
215 	struct sockaddr_storage address;
216 	struct sockaddr *sap = (struct sockaddr *)&address;
217 	size_t salen = sizeof(address);
218 	char *fo_path;
219 	struct net *net = netns(file);
220 
221 	/* sanity check */
222 	if (size == 0)
223 		return -EINVAL;
224 
225 	if (buf[size-1] != '\n')
226 		return -EINVAL;
227 
228 	fo_path = buf;
229 	if (qword_get(&buf, fo_path, size) < 0)
230 		return -EINVAL;
231 
232 	if (rpc_pton(net, fo_path, size, sap, salen) == 0)
233 		return -EINVAL;
234 
235 	trace_nfsd_ctl_unlock_ip(net, buf);
236 	return nlmsvc_unlock_all_by_ip(sap);
237 }
238 
239 /*
240  * write_unlock_fs - Release all locks on a local file system
241  *
242  * Experimental.
243  *
244  * Input:
245  *			buf:	'\n'-terminated C string containing the
246  *				absolute pathname of a local file system
247  *			size:	length of C string in @buf
248  * Output:
249  *	On success:	returns zero if all specified locks were released;
250  *			returns one if one or more locks were not released
251  *	On error:	return code is negative errno value
252  */
253 static ssize_t write_unlock_fs(struct file *file, char *buf, size_t size)
254 {
255 	struct path path;
256 	char *fo_path;
257 	int error;
258 
259 	/* sanity check */
260 	if (size == 0)
261 		return -EINVAL;
262 
263 	if (buf[size-1] != '\n')
264 		return -EINVAL;
265 
266 	fo_path = buf;
267 	if (qword_get(&buf, fo_path, size) < 0)
268 		return -EINVAL;
269 	trace_nfsd_ctl_unlock_fs(netns(file), fo_path);
270 	error = kern_path(fo_path, 0, &path);
271 	if (error)
272 		return error;
273 
274 	/*
275 	 * XXX: Needs better sanity checking.  Otherwise we could end up
276 	 * releasing locks on the wrong file system.
277 	 *
278 	 * For example:
279 	 * 1.  Does the path refer to a directory?
280 	 * 2.  Is that directory a mount point, or
281 	 * 3.  Is that directory the root of an exported file system?
282 	 */
283 	error = nlmsvc_unlock_all_by_sb(path.dentry->d_sb);
284 
285 	path_put(&path);
286 	return error;
287 }
288 
289 /*
290  * write_filehandle - Get a variable-length NFS file handle by path
291  *
292  * On input, the buffer contains a '\n'-terminated C string comprised of
293  * three alphanumeric words separated by whitespace.  The string may
294  * contain escape sequences.
295  *
296  * Input:
297  *			buf:
298  *				domain:		client domain name
299  *				path:		export pathname
300  *				maxsize:	numeric maximum size of
301  *						@buf
302  *			size:	length of C string in @buf
303  * Output:
304  *	On success:	passed-in buffer filled with '\n'-terminated C
305  *			string containing a ASCII hex text version
306  *			of the NFS file handle;
307  *			return code is the size in bytes of the string
308  *	On error:	return code is negative errno value
309  */
310 static ssize_t write_filehandle(struct file *file, char *buf, size_t size)
311 {
312 	char *dname, *path;
313 	int maxsize;
314 	char *mesg = buf;
315 	int len;
316 	struct auth_domain *dom;
317 	struct knfsd_fh fh;
318 
319 	if (size == 0)
320 		return -EINVAL;
321 
322 	if (buf[size-1] != '\n')
323 		return -EINVAL;
324 	buf[size-1] = 0;
325 
326 	dname = mesg;
327 	len = qword_get(&mesg, dname, size);
328 	if (len <= 0)
329 		return -EINVAL;
330 
331 	path = dname+len+1;
332 	len = qword_get(&mesg, path, size);
333 	if (len <= 0)
334 		return -EINVAL;
335 
336 	len = get_int(&mesg, &maxsize);
337 	if (len)
338 		return len;
339 
340 	if (maxsize < NFS_FHSIZE)
341 		return -EINVAL;
342 	maxsize = min(maxsize, NFS3_FHSIZE);
343 
344 	if (qword_get(&mesg, mesg, size) > 0)
345 		return -EINVAL;
346 
347 	trace_nfsd_ctl_filehandle(netns(file), dname, path, maxsize);
348 
349 	/* we have all the words, they are in buf.. */
350 	dom = unix_domain_find(dname);
351 	if (!dom)
352 		return -ENOMEM;
353 
354 	len = exp_rootfh(netns(file), dom, path, &fh, maxsize);
355 	auth_domain_put(dom);
356 	if (len)
357 		return len;
358 
359 	mesg = buf;
360 	len = SIMPLE_TRANSACTION_LIMIT;
361 	qword_addhex(&mesg, &len, fh.fh_raw, fh.fh_size);
362 	mesg[-1] = '\n';
363 	return mesg - buf;
364 }
365 
366 /*
367  * write_threads - Start NFSD, or report the current number of running threads
368  *
369  * Input:
370  *			buf:		ignored
371  *			size:		zero
372  * Output:
373  *	On success:	passed-in buffer filled with '\n'-terminated C
374  *			string numeric value representing the number of
375  *			running NFSD threads;
376  *			return code is the size in bytes of the string
377  *	On error:	return code is zero
378  *
379  * OR
380  *
381  * Input:
382  *			buf:		C string containing an unsigned
383  *					integer value representing the
384  *					number of NFSD threads to start
385  *			size:		non-zero length of C string in @buf
386  * Output:
387  *	On success:	NFS service is started;
388  *			passed-in buffer filled with '\n'-terminated C
389  *			string numeric value representing the number of
390  *			running NFSD threads;
391  *			return code is the size in bytes of the string
392  *	On error:	return code is zero or a negative errno value
393  */
394 static ssize_t write_threads(struct file *file, char *buf, size_t size)
395 {
396 	char *mesg = buf;
397 	int rv;
398 	struct net *net = netns(file);
399 
400 	if (size > 0) {
401 		int newthreads;
402 		rv = get_int(&mesg, &newthreads);
403 		if (rv)
404 			return rv;
405 		if (newthreads < 0)
406 			return -EINVAL;
407 		trace_nfsd_ctl_threads(net, newthreads);
408 		rv = nfsd_svc(newthreads, net, file->f_cred);
409 		if (rv < 0)
410 			return rv;
411 	} else
412 		rv = nfsd_nrthreads(net);
413 
414 	return scnprintf(buf, SIMPLE_TRANSACTION_LIMIT, "%d\n", rv);
415 }
416 
417 /*
418  * write_pool_threads - Set or report the current number of threads per pool
419  *
420  * Input:
421  *			buf:		ignored
422  *			size:		zero
423  *
424  * OR
425  *
426  * Input:
427  *			buf:		C string containing whitespace-
428  *					separated unsigned integer values
429  *					representing the number of NFSD
430  *					threads to start in each pool
431  *			size:		non-zero length of C string in @buf
432  * Output:
433  *	On success:	passed-in buffer filled with '\n'-terminated C
434  *			string containing integer values representing the
435  *			number of NFSD threads in each pool;
436  *			return code is the size in bytes of the string
437  *	On error:	return code is zero or a negative errno value
438  */
439 static ssize_t write_pool_threads(struct file *file, char *buf, size_t size)
440 {
441 	/* if size > 0, look for an array of number of threads per node
442 	 * and apply them  then write out number of threads per node as reply
443 	 */
444 	char *mesg = buf;
445 	int i;
446 	int rv;
447 	int len;
448 	int npools;
449 	int *nthreads;
450 	struct net *net = netns(file);
451 
452 	mutex_lock(&nfsd_mutex);
453 	npools = nfsd_nrpools(net);
454 	if (npools == 0) {
455 		/*
456 		 * NFS is shut down.  The admin can start it by
457 		 * writing to the threads file but NOT the pool_threads
458 		 * file, sorry.  Report zero threads.
459 		 */
460 		mutex_unlock(&nfsd_mutex);
461 		strcpy(buf, "0\n");
462 		return strlen(buf);
463 	}
464 
465 	nthreads = kcalloc(npools, sizeof(int), GFP_KERNEL);
466 	rv = -ENOMEM;
467 	if (nthreads == NULL)
468 		goto out_free;
469 
470 	if (size > 0) {
471 		for (i = 0; i < npools; i++) {
472 			rv = get_int(&mesg, &nthreads[i]);
473 			if (rv == -ENOENT)
474 				break;		/* fewer numbers than pools */
475 			if (rv)
476 				goto out_free;	/* syntax error */
477 			rv = -EINVAL;
478 			if (nthreads[i] < 0)
479 				goto out_free;
480 			trace_nfsd_ctl_pool_threads(net, i, nthreads[i]);
481 		}
482 		rv = nfsd_set_nrthreads(i, nthreads, net);
483 		if (rv)
484 			goto out_free;
485 	}
486 
487 	rv = nfsd_get_nrthreads(npools, nthreads, net);
488 	if (rv)
489 		goto out_free;
490 
491 	mesg = buf;
492 	size = SIMPLE_TRANSACTION_LIMIT;
493 	for (i = 0; i < npools && size > 0; i++) {
494 		snprintf(mesg, size, "%d%c", nthreads[i], (i == npools-1 ? '\n' : ' '));
495 		len = strlen(mesg);
496 		size -= len;
497 		mesg += len;
498 	}
499 	rv = mesg - buf;
500 out_free:
501 	kfree(nthreads);
502 	mutex_unlock(&nfsd_mutex);
503 	return rv;
504 }
505 
506 static ssize_t
507 nfsd_print_version_support(struct nfsd_net *nn, char *buf, int remaining,
508 		const char *sep, unsigned vers, int minor)
509 {
510 	const char *format = minor < 0 ? "%s%c%u" : "%s%c%u.%u";
511 	bool supported = !!nfsd_vers(nn, vers, NFSD_TEST);
512 
513 	if (vers == 4 && minor >= 0 &&
514 	    !nfsd_minorversion(nn, minor, NFSD_TEST))
515 		supported = false;
516 	if (minor == 0 && supported)
517 		/*
518 		 * special case for backward compatability.
519 		 * +4.0 is never reported, it is implied by
520 		 * +4, unless -4.0 is present.
521 		 */
522 		return 0;
523 	return snprintf(buf, remaining, format, sep,
524 			supported ? '+' : '-', vers, minor);
525 }
526 
527 static ssize_t __write_versions(struct file *file, char *buf, size_t size)
528 {
529 	char *mesg = buf;
530 	char *vers, *minorp, sign;
531 	int len, num, remaining;
532 	ssize_t tlen = 0;
533 	char *sep;
534 	struct nfsd_net *nn = net_generic(netns(file), nfsd_net_id);
535 
536 	if (size > 0) {
537 		if (nn->nfsd_serv)
538 			/* Cannot change versions without updating
539 			 * nn->nfsd_serv->sv_xdrsize, and reallocing
540 			 * rq_argp and rq_resp
541 			 */
542 			return -EBUSY;
543 		if (buf[size-1] != '\n')
544 			return -EINVAL;
545 		buf[size-1] = 0;
546 		trace_nfsd_ctl_version(netns(file), buf);
547 
548 		vers = mesg;
549 		len = qword_get(&mesg, vers, size);
550 		if (len <= 0) return -EINVAL;
551 		do {
552 			enum vers_op cmd;
553 			unsigned minor;
554 			sign = *vers;
555 			if (sign == '+' || sign == '-')
556 				num = simple_strtol((vers+1), &minorp, 0);
557 			else
558 				num = simple_strtol(vers, &minorp, 0);
559 			if (*minorp == '.') {
560 				if (num != 4)
561 					return -EINVAL;
562 				if (kstrtouint(minorp+1, 0, &minor) < 0)
563 					return -EINVAL;
564 			}
565 
566 			cmd = sign == '-' ? NFSD_CLEAR : NFSD_SET;
567 			switch(num) {
568 #ifdef CONFIG_NFSD_V2
569 			case 2:
570 #endif
571 			case 3:
572 				nfsd_vers(nn, num, cmd);
573 				break;
574 			case 4:
575 				if (*minorp == '.') {
576 					if (nfsd_minorversion(nn, minor, cmd) < 0)
577 						return -EINVAL;
578 				} else if ((cmd == NFSD_SET) != nfsd_vers(nn, num, NFSD_TEST)) {
579 					/*
580 					 * Either we have +4 and no minors are enabled,
581 					 * or we have -4 and at least one minor is enabled.
582 					 * In either case, propagate 'cmd' to all minors.
583 					 */
584 					minor = 0;
585 					while (nfsd_minorversion(nn, minor, cmd) >= 0)
586 						minor++;
587 				}
588 				break;
589 			default:
590 				/* Ignore requests to disable non-existent versions */
591 				if (cmd == NFSD_SET)
592 					return -EINVAL;
593 			}
594 			vers += len + 1;
595 		} while ((len = qword_get(&mesg, vers, size)) > 0);
596 		/* If all get turned off, turn them back on, as
597 		 * having no versions is BAD
598 		 */
599 		nfsd_reset_versions(nn);
600 	}
601 
602 	/* Now write current state into reply buffer */
603 	sep = "";
604 	remaining = SIMPLE_TRANSACTION_LIMIT;
605 	for (num=2 ; num <= 4 ; num++) {
606 		int minor;
607 		if (!nfsd_vers(nn, num, NFSD_AVAIL))
608 			continue;
609 
610 		minor = -1;
611 		do {
612 			len = nfsd_print_version_support(nn, buf, remaining,
613 					sep, num, minor);
614 			if (len >= remaining)
615 				goto out;
616 			remaining -= len;
617 			buf += len;
618 			tlen += len;
619 			minor++;
620 			if (len)
621 				sep = " ";
622 		} while (num == 4 && minor <= NFSD_SUPPORTED_MINOR_VERSION);
623 	}
624 out:
625 	len = snprintf(buf, remaining, "\n");
626 	if (len >= remaining)
627 		return -EINVAL;
628 	return tlen + len;
629 }
630 
631 /*
632  * write_versions - Set or report the available NFS protocol versions
633  *
634  * Input:
635  *			buf:		ignored
636  *			size:		zero
637  * Output:
638  *	On success:	passed-in buffer filled with '\n'-terminated C
639  *			string containing positive or negative integer
640  *			values representing the current status of each
641  *			protocol version;
642  *			return code is the size in bytes of the string
643  *	On error:	return code is zero or a negative errno value
644  *
645  * OR
646  *
647  * Input:
648  *			buf:		C string containing whitespace-
649  *					separated positive or negative
650  *					integer values representing NFS
651  *					protocol versions to enable ("+n")
652  *					or disable ("-n")
653  *			size:		non-zero length of C string in @buf
654  * Output:
655  *	On success:	status of zero or more protocol versions has
656  *			been updated; passed-in buffer filled with
657  *			'\n'-terminated C string containing positive
658  *			or negative integer values representing the
659  *			current status of each protocol version;
660  *			return code is the size in bytes of the string
661  *	On error:	return code is zero or a negative errno value
662  */
663 static ssize_t write_versions(struct file *file, char *buf, size_t size)
664 {
665 	ssize_t rv;
666 
667 	mutex_lock(&nfsd_mutex);
668 	rv = __write_versions(file, buf, size);
669 	mutex_unlock(&nfsd_mutex);
670 	return rv;
671 }
672 
673 /*
674  * Zero-length write.  Return a list of NFSD's current listener
675  * transports.
676  */
677 static ssize_t __write_ports_names(char *buf, struct net *net)
678 {
679 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
680 
681 	if (nn->nfsd_serv == NULL)
682 		return 0;
683 	return svc_xprt_names(nn->nfsd_serv, buf, SIMPLE_TRANSACTION_LIMIT);
684 }
685 
686 /*
687  * A single 'fd' number was written, in which case it must be for
688  * a socket of a supported family/protocol, and we use it as an
689  * nfsd listener.
690  */
691 static ssize_t __write_ports_addfd(char *buf, struct net *net, const struct cred *cred)
692 {
693 	char *mesg = buf;
694 	int fd, err;
695 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
696 	struct svc_serv *serv;
697 
698 	err = get_int(&mesg, &fd);
699 	if (err != 0 || fd < 0)
700 		return -EINVAL;
701 	trace_nfsd_ctl_ports_addfd(net, fd);
702 
703 	err = nfsd_create_serv(net);
704 	if (err != 0)
705 		return err;
706 
707 	serv = nn->nfsd_serv;
708 	err = svc_addsock(serv, net, fd, buf, SIMPLE_TRANSACTION_LIMIT, cred);
709 
710 	if (err < 0 && !serv->sv_nrthreads && !nn->keep_active)
711 		nfsd_last_thread(net);
712 	else if (err >= 0 && !serv->sv_nrthreads && !xchg(&nn->keep_active, 1))
713 		svc_get(serv);
714 
715 	svc_put(serv);
716 	return err;
717 }
718 
719 /*
720  * A transport listener is added by writing its transport name and
721  * a port number.
722  */
723 static ssize_t __write_ports_addxprt(char *buf, struct net *net, const struct cred *cred)
724 {
725 	char transport[16];
726 	struct svc_xprt *xprt;
727 	int port, err;
728 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
729 	struct svc_serv *serv;
730 
731 	if (sscanf(buf, "%15s %5u", transport, &port) != 2)
732 		return -EINVAL;
733 
734 	if (port < 1 || port > USHRT_MAX)
735 		return -EINVAL;
736 	trace_nfsd_ctl_ports_addxprt(net, transport, port);
737 
738 	err = nfsd_create_serv(net);
739 	if (err != 0)
740 		return err;
741 
742 	serv = nn->nfsd_serv;
743 	err = svc_xprt_create(serv, transport, net,
744 			      PF_INET, port, SVC_SOCK_ANONYMOUS, cred);
745 	if (err < 0)
746 		goto out_err;
747 
748 	err = svc_xprt_create(serv, transport, net,
749 			      PF_INET6, port, SVC_SOCK_ANONYMOUS, cred);
750 	if (err < 0 && err != -EAFNOSUPPORT)
751 		goto out_close;
752 
753 	if (!serv->sv_nrthreads && !xchg(&nn->keep_active, 1))
754 		svc_get(serv);
755 
756 	svc_put(serv);
757 	return 0;
758 out_close:
759 	xprt = svc_find_xprt(serv, transport, net, PF_INET, port);
760 	if (xprt != NULL) {
761 		svc_xprt_close(xprt);
762 		svc_xprt_put(xprt);
763 	}
764 out_err:
765 	if (!serv->sv_nrthreads && !nn->keep_active)
766 		nfsd_last_thread(net);
767 
768 	svc_put(serv);
769 	return err;
770 }
771 
772 static ssize_t __write_ports(struct file *file, char *buf, size_t size,
773 			     struct net *net)
774 {
775 	if (size == 0)
776 		return __write_ports_names(buf, net);
777 
778 	if (isdigit(buf[0]))
779 		return __write_ports_addfd(buf, net, file->f_cred);
780 
781 	if (isalpha(buf[0]))
782 		return __write_ports_addxprt(buf, net, file->f_cred);
783 
784 	return -EINVAL;
785 }
786 
787 /*
788  * write_ports - Pass a socket file descriptor or transport name to listen on
789  *
790  * Input:
791  *			buf:		ignored
792  *			size:		zero
793  * Output:
794  *	On success:	passed-in buffer filled with a '\n'-terminated C
795  *			string containing a whitespace-separated list of
796  *			named NFSD listeners;
797  *			return code is the size in bytes of the string
798  *	On error:	return code is zero or a negative errno value
799  *
800  * OR
801  *
802  * Input:
803  *			buf:		C string containing an unsigned
804  *					integer value representing a bound
805  *					but unconnected socket that is to be
806  *					used as an NFSD listener; listen(3)
807  *					must be called for a SOCK_STREAM
808  *					socket, otherwise it is ignored
809  *			size:		non-zero length of C string in @buf
810  * Output:
811  *	On success:	NFS service is started;
812  *			passed-in buffer filled with a '\n'-terminated C
813  *			string containing a unique alphanumeric name of
814  *			the listener;
815  *			return code is the size in bytes of the string
816  *	On error:	return code is a negative errno value
817  *
818  * OR
819  *
820  * Input:
821  *			buf:		C string containing a transport
822  *					name and an unsigned integer value
823  *					representing the port to listen on,
824  *					separated by whitespace
825  *			size:		non-zero length of C string in @buf
826  * Output:
827  *	On success:	returns zero; NFS service is started
828  *	On error:	return code is a negative errno value
829  */
830 static ssize_t write_ports(struct file *file, char *buf, size_t size)
831 {
832 	ssize_t rv;
833 
834 	mutex_lock(&nfsd_mutex);
835 	rv = __write_ports(file, buf, size, netns(file));
836 	mutex_unlock(&nfsd_mutex);
837 	return rv;
838 }
839 
840 
841 int nfsd_max_blksize;
842 
843 /*
844  * write_maxblksize - Set or report the current NFS blksize
845  *
846  * Input:
847  *			buf:		ignored
848  *			size:		zero
849  *
850  * OR
851  *
852  * Input:
853  *			buf:		C string containing an unsigned
854  *					integer value representing the new
855  *					NFS blksize
856  *			size:		non-zero length of C string in @buf
857  * Output:
858  *	On success:	passed-in buffer filled with '\n'-terminated C string
859  *			containing numeric value of the current NFS blksize
860  *			setting;
861  *			return code is the size in bytes of the string
862  *	On error:	return code is zero or a negative errno value
863  */
864 static ssize_t write_maxblksize(struct file *file, char *buf, size_t size)
865 {
866 	char *mesg = buf;
867 	struct nfsd_net *nn = net_generic(netns(file), nfsd_net_id);
868 
869 	if (size > 0) {
870 		int bsize;
871 		int rv = get_int(&mesg, &bsize);
872 		if (rv)
873 			return rv;
874 		trace_nfsd_ctl_maxblksize(netns(file), bsize);
875 
876 		/* force bsize into allowed range and
877 		 * required alignment.
878 		 */
879 		bsize = max_t(int, bsize, 1024);
880 		bsize = min_t(int, bsize, NFSSVC_MAXBLKSIZE);
881 		bsize &= ~(1024-1);
882 		mutex_lock(&nfsd_mutex);
883 		if (nn->nfsd_serv) {
884 			mutex_unlock(&nfsd_mutex);
885 			return -EBUSY;
886 		}
887 		nfsd_max_blksize = bsize;
888 		mutex_unlock(&nfsd_mutex);
889 	}
890 
891 	return scnprintf(buf, SIMPLE_TRANSACTION_LIMIT, "%d\n",
892 							nfsd_max_blksize);
893 }
894 
895 /*
896  * write_maxconn - Set or report the current max number of connections
897  *
898  * Input:
899  *			buf:		ignored
900  *			size:		zero
901  * OR
902  *
903  * Input:
904  *			buf:		C string containing an unsigned
905  *					integer value representing the new
906  *					number of max connections
907  *			size:		non-zero length of C string in @buf
908  * Output:
909  *	On success:	passed-in buffer filled with '\n'-terminated C string
910  *			containing numeric value of max_connections setting
911  *			for this net namespace;
912  *			return code is the size in bytes of the string
913  *	On error:	return code is zero or a negative errno value
914  */
915 static ssize_t write_maxconn(struct file *file, char *buf, size_t size)
916 {
917 	char *mesg = buf;
918 	struct nfsd_net *nn = net_generic(netns(file), nfsd_net_id);
919 	unsigned int maxconn = nn->max_connections;
920 
921 	if (size > 0) {
922 		int rv = get_uint(&mesg, &maxconn);
923 
924 		if (rv)
925 			return rv;
926 		trace_nfsd_ctl_maxconn(netns(file), maxconn);
927 		nn->max_connections = maxconn;
928 	}
929 
930 	return scnprintf(buf, SIMPLE_TRANSACTION_LIMIT, "%u\n", maxconn);
931 }
932 
933 #ifdef CONFIG_NFSD_V4
934 static ssize_t __nfsd4_write_time(struct file *file, char *buf, size_t size,
935 				  time64_t *time, struct nfsd_net *nn)
936 {
937 	struct dentry *dentry = file_dentry(file);
938 	char *mesg = buf;
939 	int rv, i;
940 
941 	if (size > 0) {
942 		if (nn->nfsd_serv)
943 			return -EBUSY;
944 		rv = get_int(&mesg, &i);
945 		if (rv)
946 			return rv;
947 		trace_nfsd_ctl_time(netns(file), dentry->d_name.name,
948 				    dentry->d_name.len, i);
949 
950 		/*
951 		 * Some sanity checking.  We don't have a reason for
952 		 * these particular numbers, but problems with the
953 		 * extremes are:
954 		 *	- Too short: the briefest network outage may
955 		 *	  cause clients to lose all their locks.  Also,
956 		 *	  the frequent polling may be wasteful.
957 		 *	- Too long: do you really want reboot recovery
958 		 *	  to take more than an hour?  Or to make other
959 		 *	  clients wait an hour before being able to
960 		 *	  revoke a dead client's locks?
961 		 */
962 		if (i < 10 || i > 3600)
963 			return -EINVAL;
964 		*time = i;
965 	}
966 
967 	return scnprintf(buf, SIMPLE_TRANSACTION_LIMIT, "%lld\n", *time);
968 }
969 
970 static ssize_t nfsd4_write_time(struct file *file, char *buf, size_t size,
971 				time64_t *time, struct nfsd_net *nn)
972 {
973 	ssize_t rv;
974 
975 	mutex_lock(&nfsd_mutex);
976 	rv = __nfsd4_write_time(file, buf, size, time, nn);
977 	mutex_unlock(&nfsd_mutex);
978 	return rv;
979 }
980 
981 /*
982  * write_leasetime - Set or report the current NFSv4 lease time
983  *
984  * Input:
985  *			buf:		ignored
986  *			size:		zero
987  *
988  * OR
989  *
990  * Input:
991  *			buf:		C string containing an unsigned
992  *					integer value representing the new
993  *					NFSv4 lease expiry time
994  *			size:		non-zero length of C string in @buf
995  * Output:
996  *	On success:	passed-in buffer filled with '\n'-terminated C
997  *			string containing unsigned integer value of the
998  *			current lease expiry time;
999  *			return code is the size in bytes of the string
1000  *	On error:	return code is zero or a negative errno value
1001  */
1002 static ssize_t write_leasetime(struct file *file, char *buf, size_t size)
1003 {
1004 	struct nfsd_net *nn = net_generic(netns(file), nfsd_net_id);
1005 	return nfsd4_write_time(file, buf, size, &nn->nfsd4_lease, nn);
1006 }
1007 
1008 /*
1009  * write_gracetime - Set or report current NFSv4 grace period time
1010  *
1011  * As above, but sets the time of the NFSv4 grace period.
1012  *
1013  * Note this should never be set to less than the *previous*
1014  * lease-period time, but we don't try to enforce this.  (In the common
1015  * case (a new boot), we don't know what the previous lease time was
1016  * anyway.)
1017  */
1018 static ssize_t write_gracetime(struct file *file, char *buf, size_t size)
1019 {
1020 	struct nfsd_net *nn = net_generic(netns(file), nfsd_net_id);
1021 	return nfsd4_write_time(file, buf, size, &nn->nfsd4_grace, nn);
1022 }
1023 
1024 static ssize_t __write_recoverydir(struct file *file, char *buf, size_t size,
1025 				   struct nfsd_net *nn)
1026 {
1027 	char *mesg = buf;
1028 	char *recdir;
1029 	int len, status;
1030 
1031 	if (size > 0) {
1032 		if (nn->nfsd_serv)
1033 			return -EBUSY;
1034 		if (size > PATH_MAX || buf[size-1] != '\n')
1035 			return -EINVAL;
1036 		buf[size-1] = 0;
1037 
1038 		recdir = mesg;
1039 		len = qword_get(&mesg, recdir, size);
1040 		if (len <= 0)
1041 			return -EINVAL;
1042 		trace_nfsd_ctl_recoverydir(netns(file), recdir);
1043 
1044 		status = nfs4_reset_recoverydir(recdir);
1045 		if (status)
1046 			return status;
1047 	}
1048 
1049 	return scnprintf(buf, SIMPLE_TRANSACTION_LIMIT, "%s\n",
1050 							nfs4_recoverydir());
1051 }
1052 
1053 /*
1054  * write_recoverydir - Set or report the pathname of the recovery directory
1055  *
1056  * Input:
1057  *			buf:		ignored
1058  *			size:		zero
1059  *
1060  * OR
1061  *
1062  * Input:
1063  *			buf:		C string containing the pathname
1064  *					of the directory on a local file
1065  *					system containing permanent NFSv4
1066  *					recovery data
1067  *			size:		non-zero length of C string in @buf
1068  * Output:
1069  *	On success:	passed-in buffer filled with '\n'-terminated C string
1070  *			containing the current recovery pathname setting;
1071  *			return code is the size in bytes of the string
1072  *	On error:	return code is zero or a negative errno value
1073  */
1074 static ssize_t write_recoverydir(struct file *file, char *buf, size_t size)
1075 {
1076 	ssize_t rv;
1077 	struct nfsd_net *nn = net_generic(netns(file), nfsd_net_id);
1078 
1079 	mutex_lock(&nfsd_mutex);
1080 	rv = __write_recoverydir(file, buf, size, nn);
1081 	mutex_unlock(&nfsd_mutex);
1082 	return rv;
1083 }
1084 
1085 /*
1086  * write_v4_end_grace - release grace period for nfsd's v4.x lock manager
1087  *
1088  * Input:
1089  *			buf:		ignored
1090  *			size:		zero
1091  * OR
1092  *
1093  * Input:
1094  *			buf:		any value
1095  *			size:		non-zero length of C string in @buf
1096  * Output:
1097  *			passed-in buffer filled with "Y" or "N" with a newline
1098  *			and NULL-terminated C string. This indicates whether
1099  *			the grace period has ended in the current net
1100  *			namespace. Return code is the size in bytes of the
1101  *			string. Writing a string that starts with 'Y', 'y', or
1102  *			'1' to the file will end the grace period for nfsd's v4
1103  *			lock manager.
1104  */
1105 static ssize_t write_v4_end_grace(struct file *file, char *buf, size_t size)
1106 {
1107 	struct nfsd_net *nn = net_generic(netns(file), nfsd_net_id);
1108 
1109 	if (size > 0) {
1110 		switch(buf[0]) {
1111 		case 'Y':
1112 		case 'y':
1113 		case '1':
1114 			if (!nn->nfsd_serv)
1115 				return -EBUSY;
1116 			trace_nfsd_end_grace(netns(file));
1117 			nfsd4_end_grace(nn);
1118 			break;
1119 		default:
1120 			return -EINVAL;
1121 		}
1122 	}
1123 
1124 	return scnprintf(buf, SIMPLE_TRANSACTION_LIMIT, "%c\n",
1125 			 nn->grace_ended ? 'Y' : 'N');
1126 }
1127 
1128 #endif
1129 
1130 /*----------------------------------------------------------------------------*/
1131 /*
1132  *	populating the filesystem.
1133  */
1134 
1135 /* Basically copying rpc_get_inode. */
1136 static struct inode *nfsd_get_inode(struct super_block *sb, umode_t mode)
1137 {
1138 	struct inode *inode = new_inode(sb);
1139 	if (!inode)
1140 		return NULL;
1141 	/* Following advice from simple_fill_super documentation: */
1142 	inode->i_ino = iunique(sb, NFSD_MaxReserved);
1143 	inode->i_mode = mode;
1144 	simple_inode_init_ts(inode);
1145 	switch (mode & S_IFMT) {
1146 	case S_IFDIR:
1147 		inode->i_fop = &simple_dir_operations;
1148 		inode->i_op = &simple_dir_inode_operations;
1149 		inc_nlink(inode);
1150 		break;
1151 	case S_IFLNK:
1152 		inode->i_op = &simple_symlink_inode_operations;
1153 		break;
1154 	default:
1155 		break;
1156 	}
1157 	return inode;
1158 }
1159 
1160 static int __nfsd_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode, struct nfsdfs_client *ncl)
1161 {
1162 	struct inode *inode;
1163 
1164 	inode = nfsd_get_inode(dir->i_sb, mode);
1165 	if (!inode)
1166 		return -ENOMEM;
1167 	if (ncl) {
1168 		inode->i_private = ncl;
1169 		kref_get(&ncl->cl_ref);
1170 	}
1171 	d_add(dentry, inode);
1172 	inc_nlink(dir);
1173 	fsnotify_mkdir(dir, dentry);
1174 	return 0;
1175 }
1176 
1177 static struct dentry *nfsd_mkdir(struct dentry *parent, struct nfsdfs_client *ncl, char *name)
1178 {
1179 	struct inode *dir = parent->d_inode;
1180 	struct dentry *dentry;
1181 	int ret = -ENOMEM;
1182 
1183 	inode_lock(dir);
1184 	dentry = d_alloc_name(parent, name);
1185 	if (!dentry)
1186 		goto out_err;
1187 	ret = __nfsd_mkdir(d_inode(parent), dentry, S_IFDIR | 0600, ncl);
1188 	if (ret)
1189 		goto out_err;
1190 out:
1191 	inode_unlock(dir);
1192 	return dentry;
1193 out_err:
1194 	dput(dentry);
1195 	dentry = ERR_PTR(ret);
1196 	goto out;
1197 }
1198 
1199 #if IS_ENABLED(CONFIG_SUNRPC_GSS)
1200 static int __nfsd_symlink(struct inode *dir, struct dentry *dentry,
1201 			  umode_t mode, const char *content)
1202 {
1203 	struct inode *inode;
1204 
1205 	inode = nfsd_get_inode(dir->i_sb, mode);
1206 	if (!inode)
1207 		return -ENOMEM;
1208 
1209 	inode->i_link = (char *)content;
1210 	inode->i_size = strlen(content);
1211 
1212 	d_add(dentry, inode);
1213 	inc_nlink(dir);
1214 	fsnotify_create(dir, dentry);
1215 	return 0;
1216 }
1217 
1218 /*
1219  * @content is assumed to be a NUL-terminated string that lives
1220  * longer than the symlink itself.
1221  */
1222 static void _nfsd_symlink(struct dentry *parent, const char *name,
1223 			  const char *content)
1224 {
1225 	struct inode *dir = parent->d_inode;
1226 	struct dentry *dentry;
1227 	int ret;
1228 
1229 	inode_lock(dir);
1230 	dentry = d_alloc_name(parent, name);
1231 	if (!dentry)
1232 		goto out;
1233 	ret = __nfsd_symlink(d_inode(parent), dentry, S_IFLNK | 0777, content);
1234 	if (ret)
1235 		dput(dentry);
1236 out:
1237 	inode_unlock(dir);
1238 }
1239 #else
1240 static inline void _nfsd_symlink(struct dentry *parent, const char *name,
1241 				 const char *content)
1242 {
1243 }
1244 
1245 #endif
1246 
1247 static void clear_ncl(struct inode *inode)
1248 {
1249 	struct nfsdfs_client *ncl = inode->i_private;
1250 
1251 	inode->i_private = NULL;
1252 	kref_put(&ncl->cl_ref, ncl->cl_release);
1253 }
1254 
1255 static struct nfsdfs_client *__get_nfsdfs_client(struct inode *inode)
1256 {
1257 	struct nfsdfs_client *nc = inode->i_private;
1258 
1259 	if (nc)
1260 		kref_get(&nc->cl_ref);
1261 	return nc;
1262 }
1263 
1264 struct nfsdfs_client *get_nfsdfs_client(struct inode *inode)
1265 {
1266 	struct nfsdfs_client *nc;
1267 
1268 	inode_lock_shared(inode);
1269 	nc = __get_nfsdfs_client(inode);
1270 	inode_unlock_shared(inode);
1271 	return nc;
1272 }
1273 /* from __rpc_unlink */
1274 static void nfsdfs_remove_file(struct inode *dir, struct dentry *dentry)
1275 {
1276 	int ret;
1277 
1278 	clear_ncl(d_inode(dentry));
1279 	dget(dentry);
1280 	ret = simple_unlink(dir, dentry);
1281 	d_drop(dentry);
1282 	fsnotify_unlink(dir, dentry);
1283 	dput(dentry);
1284 	WARN_ON_ONCE(ret);
1285 }
1286 
1287 static void nfsdfs_remove_files(struct dentry *root)
1288 {
1289 	struct dentry *dentry, *tmp;
1290 
1291 	list_for_each_entry_safe(dentry, tmp, &root->d_subdirs, d_child) {
1292 		if (!simple_positive(dentry)) {
1293 			WARN_ON_ONCE(1); /* I think this can't happen? */
1294 			continue;
1295 		}
1296 		nfsdfs_remove_file(d_inode(root), dentry);
1297 	}
1298 }
1299 
1300 /* XXX: cut'n'paste from simple_fill_super; figure out if we could share
1301  * code instead. */
1302 static  int nfsdfs_create_files(struct dentry *root,
1303 				const struct tree_descr *files,
1304 				struct dentry **fdentries)
1305 {
1306 	struct inode *dir = d_inode(root);
1307 	struct inode *inode;
1308 	struct dentry *dentry;
1309 	int i;
1310 
1311 	inode_lock(dir);
1312 	for (i = 0; files->name && files->name[0]; i++, files++) {
1313 		dentry = d_alloc_name(root, files->name);
1314 		if (!dentry)
1315 			goto out;
1316 		inode = nfsd_get_inode(d_inode(root)->i_sb,
1317 					S_IFREG | files->mode);
1318 		if (!inode) {
1319 			dput(dentry);
1320 			goto out;
1321 		}
1322 		inode->i_fop = files->ops;
1323 		inode->i_private = __get_nfsdfs_client(dir);
1324 		d_add(dentry, inode);
1325 		fsnotify_create(dir, dentry);
1326 		if (fdentries)
1327 			fdentries[i] = dentry;
1328 	}
1329 	inode_unlock(dir);
1330 	return 0;
1331 out:
1332 	nfsdfs_remove_files(root);
1333 	inode_unlock(dir);
1334 	return -ENOMEM;
1335 }
1336 
1337 /* on success, returns positive number unique to that client. */
1338 struct dentry *nfsd_client_mkdir(struct nfsd_net *nn,
1339 				 struct nfsdfs_client *ncl, u32 id,
1340 				 const struct tree_descr *files,
1341 				 struct dentry **fdentries)
1342 {
1343 	struct dentry *dentry;
1344 	char name[11];
1345 	int ret;
1346 
1347 	sprintf(name, "%u", id);
1348 
1349 	dentry = nfsd_mkdir(nn->nfsd_client_dir, ncl, name);
1350 	if (IS_ERR(dentry)) /* XXX: tossing errors? */
1351 		return NULL;
1352 	ret = nfsdfs_create_files(dentry, files, fdentries);
1353 	if (ret) {
1354 		nfsd_client_rmdir(dentry);
1355 		return NULL;
1356 	}
1357 	return dentry;
1358 }
1359 
1360 /* Taken from __rpc_rmdir: */
1361 void nfsd_client_rmdir(struct dentry *dentry)
1362 {
1363 	struct inode *dir = d_inode(dentry->d_parent);
1364 	struct inode *inode = d_inode(dentry);
1365 	int ret;
1366 
1367 	inode_lock(dir);
1368 	nfsdfs_remove_files(dentry);
1369 	clear_ncl(inode);
1370 	dget(dentry);
1371 	ret = simple_rmdir(dir, dentry);
1372 	WARN_ON_ONCE(ret);
1373 	d_drop(dentry);
1374 	fsnotify_rmdir(dir, dentry);
1375 	dput(dentry);
1376 	inode_unlock(dir);
1377 }
1378 
1379 static int nfsd_fill_super(struct super_block *sb, struct fs_context *fc)
1380 {
1381 	struct nfsd_net *nn = net_generic(current->nsproxy->net_ns,
1382 							nfsd_net_id);
1383 	struct dentry *dentry;
1384 	int ret;
1385 
1386 	static const struct tree_descr nfsd_files[] = {
1387 		[NFSD_List] = {"exports", &exports_nfsd_operations, S_IRUGO},
1388 		/* Per-export io stats use same ops as exports file */
1389 		[NFSD_Export_Stats] = {"export_stats", &exports_nfsd_operations, S_IRUGO},
1390 		[NFSD_Export_features] = {"export_features",
1391 					&export_features_fops, S_IRUGO},
1392 		[NFSD_FO_UnlockIP] = {"unlock_ip",
1393 					&transaction_ops, S_IWUSR|S_IRUSR},
1394 		[NFSD_FO_UnlockFS] = {"unlock_filesystem",
1395 					&transaction_ops, S_IWUSR|S_IRUSR},
1396 		[NFSD_Fh] = {"filehandle", &transaction_ops, S_IWUSR|S_IRUSR},
1397 		[NFSD_Threads] = {"threads", &transaction_ops, S_IWUSR|S_IRUSR},
1398 		[NFSD_Pool_Threads] = {"pool_threads", &transaction_ops, S_IWUSR|S_IRUSR},
1399 		[NFSD_Pool_Stats] = {"pool_stats", &pool_stats_operations, S_IRUGO},
1400 		[NFSD_Reply_Cache_Stats] = {"reply_cache_stats",
1401 					&nfsd_reply_cache_stats_fops, S_IRUGO},
1402 		[NFSD_Versions] = {"versions", &transaction_ops, S_IWUSR|S_IRUSR},
1403 		[NFSD_Ports] = {"portlist", &transaction_ops, S_IWUSR|S_IRUGO},
1404 		[NFSD_MaxBlkSize] = {"max_block_size", &transaction_ops, S_IWUSR|S_IRUGO},
1405 		[NFSD_MaxConnections] = {"max_connections", &transaction_ops, S_IWUSR|S_IRUGO},
1406 		[NFSD_Filecache] = {"filecache", &nfsd_file_cache_stats_fops, S_IRUGO},
1407 #ifdef CONFIG_NFSD_V4
1408 		[NFSD_Leasetime] = {"nfsv4leasetime", &transaction_ops, S_IWUSR|S_IRUSR},
1409 		[NFSD_Gracetime] = {"nfsv4gracetime", &transaction_ops, S_IWUSR|S_IRUSR},
1410 		[NFSD_RecoveryDir] = {"nfsv4recoverydir", &transaction_ops, S_IWUSR|S_IRUSR},
1411 		[NFSD_V4EndGrace] = {"v4_end_grace", &transaction_ops, S_IWUSR|S_IRUGO},
1412 #endif
1413 		/* last one */ {""}
1414 	};
1415 
1416 	ret = simple_fill_super(sb, 0x6e667364, nfsd_files);
1417 	if (ret)
1418 		return ret;
1419 	_nfsd_symlink(sb->s_root, "supported_krb5_enctypes",
1420 		      "/proc/net/rpc/gss_krb5_enctypes");
1421 	dentry = nfsd_mkdir(sb->s_root, NULL, "clients");
1422 	if (IS_ERR(dentry))
1423 		return PTR_ERR(dentry);
1424 	nn->nfsd_client_dir = dentry;
1425 	return 0;
1426 }
1427 
1428 static int nfsd_fs_get_tree(struct fs_context *fc)
1429 {
1430 	return get_tree_keyed(fc, nfsd_fill_super, get_net(fc->net_ns));
1431 }
1432 
1433 static void nfsd_fs_free_fc(struct fs_context *fc)
1434 {
1435 	if (fc->s_fs_info)
1436 		put_net(fc->s_fs_info);
1437 }
1438 
1439 static const struct fs_context_operations nfsd_fs_context_ops = {
1440 	.free		= nfsd_fs_free_fc,
1441 	.get_tree	= nfsd_fs_get_tree,
1442 };
1443 
1444 static int nfsd_init_fs_context(struct fs_context *fc)
1445 {
1446 	put_user_ns(fc->user_ns);
1447 	fc->user_ns = get_user_ns(fc->net_ns->user_ns);
1448 	fc->ops = &nfsd_fs_context_ops;
1449 	return 0;
1450 }
1451 
1452 static void nfsd_umount(struct super_block *sb)
1453 {
1454 	struct net *net = sb->s_fs_info;
1455 
1456 	nfsd_shutdown_threads(net);
1457 
1458 	kill_litter_super(sb);
1459 	put_net(net);
1460 }
1461 
1462 static struct file_system_type nfsd_fs_type = {
1463 	.owner		= THIS_MODULE,
1464 	.name		= "nfsd",
1465 	.init_fs_context = nfsd_init_fs_context,
1466 	.kill_sb	= nfsd_umount,
1467 };
1468 MODULE_ALIAS_FS("nfsd");
1469 
1470 #ifdef CONFIG_PROC_FS
1471 
1472 static int exports_proc_open(struct inode *inode, struct file *file)
1473 {
1474 	return exports_net_open(current->nsproxy->net_ns, file);
1475 }
1476 
1477 static const struct proc_ops exports_proc_ops = {
1478 	.proc_open	= exports_proc_open,
1479 	.proc_read	= seq_read,
1480 	.proc_lseek	= seq_lseek,
1481 	.proc_release	= seq_release,
1482 };
1483 
1484 static int create_proc_exports_entry(void)
1485 {
1486 	struct proc_dir_entry *entry;
1487 
1488 	entry = proc_mkdir("fs/nfs", NULL);
1489 	if (!entry)
1490 		return -ENOMEM;
1491 	entry = proc_create("exports", 0, entry, &exports_proc_ops);
1492 	if (!entry) {
1493 		remove_proc_entry("fs/nfs", NULL);
1494 		return -ENOMEM;
1495 	}
1496 	return 0;
1497 }
1498 #else /* CONFIG_PROC_FS */
1499 static int create_proc_exports_entry(void)
1500 {
1501 	return 0;
1502 }
1503 #endif
1504 
1505 unsigned int nfsd_net_id;
1506 
1507 /**
1508  * nfsd_nl_rpc_status_get_start - Prepare rpc_status_get dumpit
1509  * @cb: netlink metadata and command arguments
1510  *
1511  * Return values:
1512  *   %0: The rpc_status_get command may proceed
1513  *   %-ENODEV: There is no NFSD running in this namespace
1514  */
1515 int nfsd_nl_rpc_status_get_start(struct netlink_callback *cb)
1516 {
1517 	struct nfsd_net *nn = net_generic(sock_net(cb->skb->sk), nfsd_net_id);
1518 	int ret = -ENODEV;
1519 
1520 	mutex_lock(&nfsd_mutex);
1521 	if (nn->nfsd_serv)
1522 		ret = 0;
1523 	else
1524 		mutex_unlock(&nfsd_mutex);
1525 
1526 	return ret;
1527 }
1528 
1529 static int nfsd_genl_rpc_status_compose_msg(struct sk_buff *skb,
1530 					    struct netlink_callback *cb,
1531 					    struct nfsd_genl_rqstp *rqstp)
1532 {
1533 	void *hdr;
1534 	u32 i;
1535 
1536 	hdr = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
1537 			  &nfsd_nl_family, 0, NFSD_CMD_RPC_STATUS_GET);
1538 	if (!hdr)
1539 		return -ENOBUFS;
1540 
1541 	if (nla_put_be32(skb, NFSD_A_RPC_STATUS_XID, rqstp->rq_xid) ||
1542 	    nla_put_u32(skb, NFSD_A_RPC_STATUS_FLAGS, rqstp->rq_flags) ||
1543 	    nla_put_u32(skb, NFSD_A_RPC_STATUS_PROG, rqstp->rq_prog) ||
1544 	    nla_put_u32(skb, NFSD_A_RPC_STATUS_PROC, rqstp->rq_proc) ||
1545 	    nla_put_u8(skb, NFSD_A_RPC_STATUS_VERSION, rqstp->rq_vers) ||
1546 	    nla_put_s64(skb, NFSD_A_RPC_STATUS_SERVICE_TIME,
1547 			ktime_to_us(rqstp->rq_stime),
1548 			NFSD_A_RPC_STATUS_PAD))
1549 		return -ENOBUFS;
1550 
1551 	switch (rqstp->rq_saddr.sa_family) {
1552 	case AF_INET: {
1553 		const struct sockaddr_in *s_in, *d_in;
1554 
1555 		s_in = (const struct sockaddr_in *)&rqstp->rq_saddr;
1556 		d_in = (const struct sockaddr_in *)&rqstp->rq_daddr;
1557 		if (nla_put_in_addr(skb, NFSD_A_RPC_STATUS_SADDR4,
1558 				    s_in->sin_addr.s_addr) ||
1559 		    nla_put_in_addr(skb, NFSD_A_RPC_STATUS_DADDR4,
1560 				    d_in->sin_addr.s_addr) ||
1561 		    nla_put_be16(skb, NFSD_A_RPC_STATUS_SPORT,
1562 				 s_in->sin_port) ||
1563 		    nla_put_be16(skb, NFSD_A_RPC_STATUS_DPORT,
1564 				 d_in->sin_port))
1565 			return -ENOBUFS;
1566 		break;
1567 	}
1568 	case AF_INET6: {
1569 		const struct sockaddr_in6 *s_in, *d_in;
1570 
1571 		s_in = (const struct sockaddr_in6 *)&rqstp->rq_saddr;
1572 		d_in = (const struct sockaddr_in6 *)&rqstp->rq_daddr;
1573 		if (nla_put_in6_addr(skb, NFSD_A_RPC_STATUS_SADDR6,
1574 				     &s_in->sin6_addr) ||
1575 		    nla_put_in6_addr(skb, NFSD_A_RPC_STATUS_DADDR6,
1576 				     &d_in->sin6_addr) ||
1577 		    nla_put_be16(skb, NFSD_A_RPC_STATUS_SPORT,
1578 				 s_in->sin6_port) ||
1579 		    nla_put_be16(skb, NFSD_A_RPC_STATUS_DPORT,
1580 				 d_in->sin6_port))
1581 			return -ENOBUFS;
1582 		break;
1583 	}
1584 	}
1585 
1586 	for (i = 0; i < rqstp->rq_opcnt; i++)
1587 		if (nla_put_u32(skb, NFSD_A_RPC_STATUS_COMPOUND_OPS,
1588 				rqstp->rq_opnum[i]))
1589 			return -ENOBUFS;
1590 
1591 	genlmsg_end(skb, hdr);
1592 	return 0;
1593 }
1594 
1595 /**
1596  * nfsd_nl_rpc_status_get_dumpit - Handle rpc_status_get dumpit
1597  * @skb: reply buffer
1598  * @cb: netlink metadata and command arguments
1599  *
1600  * Returns the size of the reply or a negative errno.
1601  */
1602 int nfsd_nl_rpc_status_get_dumpit(struct sk_buff *skb,
1603 				  struct netlink_callback *cb)
1604 {
1605 	struct nfsd_net *nn = net_generic(sock_net(skb->sk), nfsd_net_id);
1606 	int i, ret, rqstp_index = 0;
1607 
1608 	rcu_read_lock();
1609 
1610 	for (i = 0; i < nn->nfsd_serv->sv_nrpools; i++) {
1611 		struct svc_rqst *rqstp;
1612 
1613 		if (i < cb->args[0]) /* already consumed */
1614 			continue;
1615 
1616 		rqstp_index = 0;
1617 		list_for_each_entry_rcu(rqstp,
1618 				&nn->nfsd_serv->sv_pools[i].sp_all_threads,
1619 				rq_all) {
1620 			struct nfsd_genl_rqstp genl_rqstp;
1621 			unsigned int status_counter;
1622 
1623 			if (rqstp_index++ < cb->args[1]) /* already consumed */
1624 				continue;
1625 			/*
1626 			 * Acquire rq_status_counter before parsing the rqst
1627 			 * fields. rq_status_counter is set to an odd value in
1628 			 * order to notify the consumers the rqstp fields are
1629 			 * meaningful.
1630 			 */
1631 			status_counter =
1632 				smp_load_acquire(&rqstp->rq_status_counter);
1633 			if (!(status_counter & 1))
1634 				continue;
1635 
1636 			genl_rqstp.rq_xid = rqstp->rq_xid;
1637 			genl_rqstp.rq_flags = rqstp->rq_flags;
1638 			genl_rqstp.rq_vers = rqstp->rq_vers;
1639 			genl_rqstp.rq_prog = rqstp->rq_prog;
1640 			genl_rqstp.rq_proc = rqstp->rq_proc;
1641 			genl_rqstp.rq_stime = rqstp->rq_stime;
1642 			genl_rqstp.rq_opcnt = 0;
1643 			memcpy(&genl_rqstp.rq_daddr, svc_daddr(rqstp),
1644 			       sizeof(struct sockaddr));
1645 			memcpy(&genl_rqstp.rq_saddr, svc_addr(rqstp),
1646 			       sizeof(struct sockaddr));
1647 
1648 #ifdef CONFIG_NFSD_V4
1649 			if (rqstp->rq_vers == NFS4_VERSION &&
1650 			    rqstp->rq_proc == NFSPROC4_COMPOUND) {
1651 				/* NFSv4 compound */
1652 				struct nfsd4_compoundargs *args;
1653 				int j;
1654 
1655 				args = rqstp->rq_argp;
1656 				genl_rqstp.rq_opcnt = args->opcnt;
1657 				for (j = 0; j < genl_rqstp.rq_opcnt; j++)
1658 					genl_rqstp.rq_opnum[j] =
1659 						args->ops[j].opnum;
1660 			}
1661 #endif /* CONFIG_NFSD_V4 */
1662 
1663 			/*
1664 			 * Acquire rq_status_counter before reporting the rqst
1665 			 * fields to the user.
1666 			 */
1667 			if (smp_load_acquire(&rqstp->rq_status_counter) !=
1668 			    status_counter)
1669 				continue;
1670 
1671 			ret = nfsd_genl_rpc_status_compose_msg(skb, cb,
1672 							       &genl_rqstp);
1673 			if (ret)
1674 				goto out;
1675 		}
1676 	}
1677 
1678 	cb->args[0] = i;
1679 	cb->args[1] = rqstp_index;
1680 	ret = skb->len;
1681 out:
1682 	rcu_read_unlock();
1683 
1684 	return ret;
1685 }
1686 
1687 /**
1688  * nfsd_nl_rpc_status_get_done - rpc_status_get dumpit post-processing
1689  * @cb: netlink metadata and command arguments
1690  *
1691  * Return values:
1692  *   %0: Success
1693  */
1694 int nfsd_nl_rpc_status_get_done(struct netlink_callback *cb)
1695 {
1696 	mutex_unlock(&nfsd_mutex);
1697 
1698 	return 0;
1699 }
1700 
1701 /**
1702  * nfsd_net_init - Prepare the nfsd_net portion of a new net namespace
1703  * @net: a freshly-created network namespace
1704  *
1705  * This information stays around as long as the network namespace is
1706  * alive whether or not there is an NFSD instance running in the
1707  * namespace.
1708  *
1709  * Returns zero on success, or a negative errno otherwise.
1710  */
1711 static __net_init int nfsd_net_init(struct net *net)
1712 {
1713 	int retval;
1714 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1715 
1716 	retval = nfsd_export_init(net);
1717 	if (retval)
1718 		goto out_export_error;
1719 	retval = nfsd_idmap_init(net);
1720 	if (retval)
1721 		goto out_idmap_error;
1722 	retval = nfsd_net_reply_cache_init(nn);
1723 	if (retval)
1724 		goto out_repcache_error;
1725 	nn->nfsd_versions = NULL;
1726 	nn->nfsd4_minorversions = NULL;
1727 	nfsd4_init_leases_net(nn);
1728 	get_random_bytes(&nn->siphash_key, sizeof(nn->siphash_key));
1729 	seqlock_init(&nn->writeverf_lock);
1730 
1731 	return 0;
1732 
1733 out_repcache_error:
1734 	nfsd_idmap_shutdown(net);
1735 out_idmap_error:
1736 	nfsd_export_shutdown(net);
1737 out_export_error:
1738 	return retval;
1739 }
1740 
1741 /**
1742  * nfsd_net_exit - Release the nfsd_net portion of a net namespace
1743  * @net: a network namespace that is about to be destroyed
1744  *
1745  */
1746 static __net_exit void nfsd_net_exit(struct net *net)
1747 {
1748 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1749 
1750 	nfsd_net_reply_cache_destroy(nn);
1751 	nfsd_idmap_shutdown(net);
1752 	nfsd_export_shutdown(net);
1753 	nfsd_netns_free_versions(nn);
1754 }
1755 
1756 static struct pernet_operations nfsd_net_ops = {
1757 	.init = nfsd_net_init,
1758 	.exit = nfsd_net_exit,
1759 	.id   = &nfsd_net_id,
1760 	.size = sizeof(struct nfsd_net),
1761 };
1762 
1763 static int __init init_nfsd(void)
1764 {
1765 	int retval;
1766 
1767 	retval = nfsd4_init_slabs();
1768 	if (retval)
1769 		return retval;
1770 	retval = nfsd4_init_pnfs();
1771 	if (retval)
1772 		goto out_free_slabs;
1773 	retval = nfsd_stat_init();	/* Statistics */
1774 	if (retval)
1775 		goto out_free_pnfs;
1776 	retval = nfsd_drc_slab_create();
1777 	if (retval)
1778 		goto out_free_stat;
1779 	nfsd_lockd_init();	/* lockd->nfsd callbacks */
1780 	retval = create_proc_exports_entry();
1781 	if (retval)
1782 		goto out_free_lockd;
1783 	retval = register_pernet_subsys(&nfsd_net_ops);
1784 	if (retval < 0)
1785 		goto out_free_exports;
1786 	retval = register_cld_notifier();
1787 	if (retval)
1788 		goto out_free_subsys;
1789 	retval = nfsd4_create_laundry_wq();
1790 	if (retval)
1791 		goto out_free_cld;
1792 	retval = register_filesystem(&nfsd_fs_type);
1793 	if (retval)
1794 		goto out_free_all;
1795 	retval = genl_register_family(&nfsd_nl_family);
1796 	if (retval)
1797 		goto out_free_all;
1798 
1799 	return 0;
1800 out_free_all:
1801 	nfsd4_destroy_laundry_wq();
1802 out_free_cld:
1803 	unregister_cld_notifier();
1804 out_free_subsys:
1805 	unregister_pernet_subsys(&nfsd_net_ops);
1806 out_free_exports:
1807 	remove_proc_entry("fs/nfs/exports", NULL);
1808 	remove_proc_entry("fs/nfs", NULL);
1809 out_free_lockd:
1810 	nfsd_lockd_shutdown();
1811 	nfsd_drc_slab_free();
1812 out_free_stat:
1813 	nfsd_stat_shutdown();
1814 out_free_pnfs:
1815 	nfsd4_exit_pnfs();
1816 out_free_slabs:
1817 	nfsd4_free_slabs();
1818 	return retval;
1819 }
1820 
1821 static void __exit exit_nfsd(void)
1822 {
1823 	genl_unregister_family(&nfsd_nl_family);
1824 	unregister_filesystem(&nfsd_fs_type);
1825 	nfsd4_destroy_laundry_wq();
1826 	unregister_cld_notifier();
1827 	unregister_pernet_subsys(&nfsd_net_ops);
1828 	nfsd_drc_slab_free();
1829 	remove_proc_entry("fs/nfs/exports", NULL);
1830 	remove_proc_entry("fs/nfs", NULL);
1831 	nfsd_stat_shutdown();
1832 	nfsd_lockd_shutdown();
1833 	nfsd4_free_slabs();
1834 	nfsd4_exit_pnfs();
1835 }
1836 
1837 MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>");
1838 MODULE_DESCRIPTION("In-kernel NFS server");
1839 MODULE_LICENSE("GPL");
1840 module_init(init_nfsd)
1841 module_exit(exit_nfsd)
1842