xref: /freebsd/sys/fs/tmpfs/tmpfs_vfsops.c (revision e17f5b1d)
1 /*	$NetBSD: tmpfs_vfsops.c,v 1.10 2005/12/11 12:24:29 christos Exp $	*/
2 
3 /*-
4  * SPDX-License-Identifier: BSD-2-Clause-NetBSD
5  *
6  * Copyright (c) 2005 The NetBSD Foundation, Inc.
7  * All rights reserved.
8  *
9  * This code is derived from software contributed to The NetBSD Foundation
10  * by Julio M. Merino Vidal, developed as part of Google's Summer of Code
11  * 2005 program.
12  *
13  * Redistribution and use in source and binary forms, with or without
14  * modification, are permitted provided that the following conditions
15  * are met:
16  * 1. Redistributions of source code must retain the above copyright
17  *    notice, this list of conditions and the following disclaimer.
18  * 2. Redistributions in binary form must reproduce the above copyright
19  *    notice, this list of conditions and the following disclaimer in the
20  *    documentation and/or other materials provided with the distribution.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
23  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
24  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
25  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
26  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
27  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
28  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
29  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
30  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
31  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
32  * POSSIBILITY OF SUCH DAMAGE.
33  */
34 
35 /*
36  * Efficient memory file system.
37  *
38  * tmpfs is a file system that uses FreeBSD's virtual memory
39  * sub-system to store file data and metadata in an efficient way.
40  * This means that it does not follow the structure of an on-disk file
41  * system because it simply does not need to.  Instead, it uses
42  * memory-specific data structures and algorithms to automatically
43  * allocate and release resources.
44  */
45 
46 #include "opt_tmpfs.h"
47 
48 #include <sys/cdefs.h>
49 __FBSDID("$FreeBSD$");
50 
51 #include <sys/param.h>
52 #include <sys/systm.h>
53 #include <sys/dirent.h>
54 #include <sys/limits.h>
55 #include <sys/lock.h>
56 #include <sys/mount.h>
57 #include <sys/mutex.h>
58 #include <sys/proc.h>
59 #include <sys/jail.h>
60 #include <sys/kernel.h>
61 #include <sys/rwlock.h>
62 #include <sys/stat.h>
63 #include <sys/sx.h>
64 #include <sys/sysctl.h>
65 #include <sys/vnode.h>
66 
67 #include <vm/vm.h>
68 #include <vm/vm_param.h>
69 #include <vm/pmap.h>
70 #include <vm/vm_extern.h>
71 #include <vm/vm_map.h>
72 #include <vm/vm_object.h>
73 #include <vm/vm_param.h>
74 
75 #include <fs/tmpfs/tmpfs.h>
76 
77 /*
78  * Default permission for root node
79  */
80 #define TMPFS_DEFAULT_ROOT_MODE	(S_IRWXU|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH)
81 
82 MALLOC_DEFINE(M_TMPFSMNT, "tmpfs mount", "tmpfs mount structures");
83 MALLOC_DEFINE(M_TMPFSNAME, "tmpfs name", "tmpfs file names");
84 
85 static int	tmpfs_mount(struct mount *);
86 static int	tmpfs_unmount(struct mount *, int);
87 static int	tmpfs_root(struct mount *, int flags, struct vnode **);
88 static int	tmpfs_fhtovp(struct mount *, struct fid *, int,
89 		    struct vnode **);
90 static int	tmpfs_statfs(struct mount *, struct statfs *);
91 
92 static const char *tmpfs_opts[] = {
93 	"from", "size", "maxfilesize", "inodes", "uid", "gid", "mode", "export",
94 	"union", "nonc", "nomtime", NULL
95 };
96 
97 static const char *tmpfs_updateopts[] = {
98 	"from", "export", "nomtime", "size", NULL
99 };
100 
101 /*
102  * Handle updates of time from writes to mmaped regions, if allowed.
103  * Use MNT_VNODE_FOREACH_ALL instead of MNT_VNODE_FOREACH_LAZY, since
104  * unmap of the tmpfs-backed vnode does not call vinactive(), due to
105  * vm object type is OBJT_SWAP.  If lazy, only handle delayed update
106  * of mtime due to the writes to mapped files.
107  */
108 static void
109 tmpfs_update_mtime(struct mount *mp, bool lazy)
110 {
111 	struct vnode *vp, *mvp;
112 	struct vm_object *obj;
113 
114 	if (VFS_TO_TMPFS(mp)->tm_nomtime)
115 		return;
116 	MNT_VNODE_FOREACH_ALL(vp, mp, mvp) {
117 		if (vp->v_type != VREG) {
118 			VI_UNLOCK(vp);
119 			continue;
120 		}
121 		obj = vp->v_object;
122 		KASSERT((obj->flags & (OBJ_TMPFS_NODE | OBJ_TMPFS)) ==
123 		    (OBJ_TMPFS_NODE | OBJ_TMPFS), ("non-tmpfs obj"));
124 
125 		/*
126 		 * In lazy case, do unlocked read, avoid taking vnode
127 		 * lock if not needed.  Lost update will be handled on
128 		 * the next call.
129 		 * For non-lazy case, we must flush all pending
130 		 * metadata changes now.
131 		 */
132 		if (!lazy || obj->generation != obj->cleangeneration) {
133 			if (vget(vp, LK_EXCLUSIVE | LK_INTERLOCK,
134 			    curthread) != 0)
135 				continue;
136 			tmpfs_check_mtime(vp);
137 			if (!lazy)
138 				tmpfs_update(vp);
139 			vput(vp);
140 		} else {
141 			VI_UNLOCK(vp);
142 			continue;
143 		}
144 	}
145 }
146 
147 struct tmpfs_check_rw_maps_arg {
148 	bool found;
149 };
150 
151 static bool
152 tmpfs_check_rw_maps_cb(struct mount *mp __unused, vm_map_t map __unused,
153     vm_map_entry_t entry __unused, void *arg)
154 {
155 	struct tmpfs_check_rw_maps_arg *a;
156 
157 	a = arg;
158 	a->found = true;
159 	return (true);
160 }
161 
162 /*
163  * Revoke write permissions from all mappings of regular files
164  * belonging to the specified tmpfs mount.
165  */
166 static bool
167 tmpfs_revoke_rw_maps_cb(struct mount *mp __unused, vm_map_t map,
168     vm_map_entry_t entry, void *arg __unused)
169 {
170 
171 	/*
172 	 * XXXKIB: might be invalidate the mapping
173 	 * instead ?  The process is not going to be
174 	 * happy in any case.
175 	 */
176 	entry->max_protection &= ~VM_PROT_WRITE;
177 	if ((entry->protection & VM_PROT_WRITE) != 0) {
178 		entry->protection &= ~VM_PROT_WRITE;
179 		pmap_protect(map->pmap, entry->start, entry->end,
180 		    entry->protection);
181 	}
182 	return (false);
183 }
184 
185 static void
186 tmpfs_all_rw_maps(struct mount *mp, bool (*cb)(struct mount *mp, vm_map_t,
187     vm_map_entry_t, void *), void *cb_arg)
188 {
189 	struct proc *p;
190 	struct vmspace *vm;
191 	vm_map_t map;
192 	vm_map_entry_t entry;
193 	vm_object_t object;
194 	struct vnode *vp;
195 	int gen;
196 	bool terminate;
197 
198 	terminate = false;
199 	sx_slock(&allproc_lock);
200 again:
201 	gen = allproc_gen;
202 	FOREACH_PROC_IN_SYSTEM(p) {
203 		PROC_LOCK(p);
204 		if (p->p_state != PRS_NORMAL || (p->p_flag & (P_INEXEC |
205 		    P_SYSTEM | P_WEXIT)) != 0) {
206 			PROC_UNLOCK(p);
207 			continue;
208 		}
209 		vm = vmspace_acquire_ref(p);
210 		_PHOLD_LITE(p);
211 		PROC_UNLOCK(p);
212 		if (vm == NULL) {
213 			PRELE(p);
214 			continue;
215 		}
216 		sx_sunlock(&allproc_lock);
217 		map = &vm->vm_map;
218 
219 		vm_map_lock(map);
220 		if (map->busy)
221 			vm_map_wait_busy(map);
222 		VM_MAP_ENTRY_FOREACH(entry, map) {
223 			if ((entry->eflags & (MAP_ENTRY_GUARD |
224 			    MAP_ENTRY_IS_SUB_MAP | MAP_ENTRY_COW)) != 0 ||
225 			    (entry->max_protection & VM_PROT_WRITE) == 0)
226 				continue;
227 			object = entry->object.vm_object;
228 			if (object == NULL || object->type != OBJT_SWAP ||
229 			    (object->flags & OBJ_TMPFS_NODE) == 0)
230 				continue;
231 			/*
232 			 * No need to dig into shadow chain, mapping
233 			 * of the object not at top is readonly.
234 			 */
235 
236 			VM_OBJECT_RLOCK(object);
237 			if (object->type == OBJT_DEAD) {
238 				VM_OBJECT_RUNLOCK(object);
239 				continue;
240 			}
241 			MPASS(object->ref_count > 1);
242 			if ((object->flags & (OBJ_TMPFS_NODE | OBJ_TMPFS)) !=
243 			    (OBJ_TMPFS_NODE | OBJ_TMPFS)) {
244 				VM_OBJECT_RUNLOCK(object);
245 				continue;
246 			}
247 			vp = object->un_pager.swp.swp_tmpfs;
248 			if (vp->v_mount != mp) {
249 				VM_OBJECT_RUNLOCK(object);
250 				continue;
251 			}
252 
253 			terminate = cb(mp, map, entry, cb_arg);
254 			VM_OBJECT_RUNLOCK(object);
255 			if (terminate)
256 				break;
257 		}
258 		vm_map_unlock(map);
259 
260 		vmspace_free(vm);
261 		sx_slock(&allproc_lock);
262 		PRELE(p);
263 		if (terminate)
264 			break;
265 	}
266 	if (!terminate && gen != allproc_gen)
267 		goto again;
268 	sx_sunlock(&allproc_lock);
269 }
270 
271 static bool
272 tmpfs_check_rw_maps(struct mount *mp)
273 {
274 	struct tmpfs_check_rw_maps_arg ca;
275 
276 	ca.found = false;
277 	tmpfs_all_rw_maps(mp, tmpfs_check_rw_maps_cb, &ca);
278 	return (ca.found);
279 }
280 
281 static int
282 tmpfs_rw_to_ro(struct mount *mp)
283 {
284 	int error, flags;
285 	bool forced;
286 
287 	forced = (mp->mnt_flag & MNT_FORCE) != 0;
288 	flags = WRITECLOSE | (forced ? FORCECLOSE : 0);
289 
290 	if ((error = vn_start_write(NULL, &mp, V_WAIT)) != 0)
291 		return (error);
292 	error = vfs_write_suspend_umnt(mp);
293 	if (error != 0)
294 		return (error);
295 	if (!forced && tmpfs_check_rw_maps(mp)) {
296 		error = EBUSY;
297 		goto out;
298 	}
299 	VFS_TO_TMPFS(mp)->tm_ronly = 1;
300 	MNT_ILOCK(mp);
301 	mp->mnt_flag |= MNT_RDONLY;
302 	MNT_IUNLOCK(mp);
303 	for (;;) {
304 		tmpfs_all_rw_maps(mp, tmpfs_revoke_rw_maps_cb, NULL);
305 		tmpfs_update_mtime(mp, false);
306 		error = vflush(mp, 0, flags, curthread);
307 		if (error != 0) {
308 			VFS_TO_TMPFS(mp)->tm_ronly = 0;
309 			MNT_ILOCK(mp);
310 			mp->mnt_flag &= ~MNT_RDONLY;
311 			MNT_IUNLOCK(mp);
312 			goto out;
313 		}
314 		if (!tmpfs_check_rw_maps(mp))
315 			break;
316 	}
317 out:
318 	vfs_write_resume(mp, 0);
319 	return (error);
320 }
321 
322 static int
323 tmpfs_mount(struct mount *mp)
324 {
325 	const size_t nodes_per_page = howmany(PAGE_SIZE,
326 	    sizeof(struct tmpfs_dirent) + sizeof(struct tmpfs_node));
327 	struct tmpfs_mount *tmp;
328 	struct tmpfs_node *root;
329 	int error;
330 	bool nomtime, nonc;
331 	/* Size counters. */
332 	u_quad_t pages;
333 	off_t nodes_max, size_max, maxfilesize;
334 
335 	/* Root node attributes. */
336 	uid_t root_uid;
337 	gid_t root_gid;
338 	mode_t root_mode;
339 
340 	struct vattr va;
341 
342 	if (vfs_filteropt(mp->mnt_optnew, tmpfs_opts))
343 		return (EINVAL);
344 
345 	if (mp->mnt_flag & MNT_UPDATE) {
346 		/* Only support update mounts for certain options. */
347 		if (vfs_filteropt(mp->mnt_optnew, tmpfs_updateopts) != 0)
348 			return (EOPNOTSUPP);
349 		tmp = VFS_TO_TMPFS(mp);
350 		if (vfs_getopt_size(mp->mnt_optnew, "size", &size_max) == 0) {
351 			/*
352 			 * On-the-fly resizing is not supported (yet). We still
353 			 * need to have "size" listed as "supported", otherwise
354 			 * trying to update fs that is listed in fstab with size
355 			 * parameter, say trying to change rw to ro or vice
356 			 * versa, would cause vfs_filteropt() to bail.
357 			 */
358 			if (size_max != tmp->tm_size_max)
359 				return (EOPNOTSUPP);
360 		}
361 		if (vfs_flagopt(mp->mnt_optnew, "ro", NULL, 0) &&
362 		    !tmp->tm_ronly) {
363 			/* RW -> RO */
364 			return (tmpfs_rw_to_ro(mp));
365 		} else if (!vfs_flagopt(mp->mnt_optnew, "ro", NULL, 0) &&
366 		    tmp->tm_ronly) {
367 			/* RO -> RW */
368 			tmp->tm_ronly = 0;
369 			MNT_ILOCK(mp);
370 			mp->mnt_flag &= ~MNT_RDONLY;
371 			MNT_IUNLOCK(mp);
372 		}
373 		tmp->tm_nomtime = vfs_getopt(mp->mnt_optnew, "nomtime", NULL,
374 		    0) == 0;
375 		return (0);
376 	}
377 
378 	vn_lock(mp->mnt_vnodecovered, LK_SHARED | LK_RETRY);
379 	error = VOP_GETATTR(mp->mnt_vnodecovered, &va, mp->mnt_cred);
380 	VOP_UNLOCK(mp->mnt_vnodecovered);
381 	if (error)
382 		return (error);
383 
384 	if (mp->mnt_cred->cr_ruid != 0 ||
385 	    vfs_scanopt(mp->mnt_optnew, "gid", "%d", &root_gid) != 1)
386 		root_gid = va.va_gid;
387 	if (mp->mnt_cred->cr_ruid != 0 ||
388 	    vfs_scanopt(mp->mnt_optnew, "uid", "%d", &root_uid) != 1)
389 		root_uid = va.va_uid;
390 	if (mp->mnt_cred->cr_ruid != 0 ||
391 	    vfs_scanopt(mp->mnt_optnew, "mode", "%ho", &root_mode) != 1)
392 		root_mode = va.va_mode;
393 	if (vfs_getopt_size(mp->mnt_optnew, "inodes", &nodes_max) != 0)
394 		nodes_max = 0;
395 	if (vfs_getopt_size(mp->mnt_optnew, "size", &size_max) != 0)
396 		size_max = 0;
397 	if (vfs_getopt_size(mp->mnt_optnew, "maxfilesize", &maxfilesize) != 0)
398 		maxfilesize = 0;
399 	nonc = vfs_getopt(mp->mnt_optnew, "nonc", NULL, NULL) == 0;
400 	nomtime = vfs_getopt(mp->mnt_optnew, "nomtime", NULL, NULL) == 0;
401 
402 	/* Do not allow mounts if we do not have enough memory to preserve
403 	 * the minimum reserved pages. */
404 	if (tmpfs_mem_avail() < TMPFS_PAGES_MINRESERVED)
405 		return (ENOSPC);
406 
407 	/* Get the maximum number of memory pages this file system is
408 	 * allowed to use, based on the maximum size the user passed in
409 	 * the mount structure.  A value of zero is treated as if the
410 	 * maximum available space was requested. */
411 	if (size_max == 0 || size_max > OFF_MAX - PAGE_SIZE ||
412 	    (SIZE_MAX < OFF_MAX && size_max / PAGE_SIZE >= SIZE_MAX))
413 		pages = SIZE_MAX;
414 	else {
415 		size_max = roundup(size_max, PAGE_SIZE);
416 		pages = howmany(size_max, PAGE_SIZE);
417 	}
418 	MPASS(pages > 0);
419 
420 	if (nodes_max <= 3) {
421 		if (pages < INT_MAX / nodes_per_page)
422 			nodes_max = pages * nodes_per_page;
423 		else
424 			nodes_max = INT_MAX;
425 	}
426 	if (nodes_max > INT_MAX)
427 		nodes_max = INT_MAX;
428 	MPASS(nodes_max >= 3);
429 
430 	/* Allocate the tmpfs mount structure and fill it. */
431 	tmp = (struct tmpfs_mount *)malloc(sizeof(struct tmpfs_mount),
432 	    M_TMPFSMNT, M_WAITOK | M_ZERO);
433 
434 	mtx_init(&tmp->tm_allnode_lock, "tmpfs allnode lock", NULL, MTX_DEF);
435 	tmp->tm_nodes_max = nodes_max;
436 	tmp->tm_nodes_inuse = 0;
437 	tmp->tm_refcount = 1;
438 	tmp->tm_maxfilesize = maxfilesize > 0 ? maxfilesize : OFF_MAX;
439 	LIST_INIT(&tmp->tm_nodes_used);
440 
441 	tmp->tm_size_max = size_max;
442 	tmp->tm_pages_max = pages;
443 	tmp->tm_pages_used = 0;
444 	new_unrhdr64(&tmp->tm_ino_unr, 2);
445 	tmp->tm_ronly = (mp->mnt_flag & MNT_RDONLY) != 0;
446 	tmp->tm_nonc = nonc;
447 	tmp->tm_nomtime = nomtime;
448 
449 	/* Allocate the root node. */
450 	error = tmpfs_alloc_node(mp, tmp, VDIR, root_uid, root_gid,
451 	    root_mode & ALLPERMS, NULL, NULL, VNOVAL, &root);
452 
453 	if (error != 0 || root == NULL) {
454 		free(tmp, M_TMPFSMNT);
455 		return (error);
456 	}
457 	KASSERT(root->tn_id == 2,
458 	    ("tmpfs root with invalid ino: %ju", (uintmax_t)root->tn_id));
459 	tmp->tm_root = root;
460 
461 	MNT_ILOCK(mp);
462 	mp->mnt_flag |= MNT_LOCAL;
463 	mp->mnt_kern_flag |= MNTK_LOOKUP_SHARED | MNTK_EXTENDED_SHARED |
464 	    MNTK_TEXT_REFS | MNTK_NOMSYNC;
465 	MNT_IUNLOCK(mp);
466 
467 	mp->mnt_data = tmp;
468 	mp->mnt_stat.f_namemax = MAXNAMLEN;
469 	vfs_getnewfsid(mp);
470 	vfs_mountedfrom(mp, "tmpfs");
471 
472 	return 0;
473 }
474 
475 /* ARGSUSED2 */
476 static int
477 tmpfs_unmount(struct mount *mp, int mntflags)
478 {
479 	struct tmpfs_mount *tmp;
480 	struct tmpfs_node *node;
481 	int error, flags;
482 
483 	flags = (mntflags & MNT_FORCE) != 0 ? FORCECLOSE : 0;
484 	tmp = VFS_TO_TMPFS(mp);
485 
486 	/* Stop writers */
487 	error = vfs_write_suspend_umnt(mp);
488 	if (error != 0)
489 		return (error);
490 	/*
491 	 * At this point, nodes cannot be destroyed by any other
492 	 * thread because write suspension is started.
493 	 */
494 
495 	for (;;) {
496 		error = vflush(mp, 0, flags, curthread);
497 		if (error != 0) {
498 			vfs_write_resume(mp, VR_START_WRITE);
499 			return (error);
500 		}
501 		MNT_ILOCK(mp);
502 		if (mp->mnt_nvnodelistsize == 0) {
503 			MNT_IUNLOCK(mp);
504 			break;
505 		}
506 		MNT_IUNLOCK(mp);
507 		if ((mntflags & MNT_FORCE) == 0) {
508 			vfs_write_resume(mp, VR_START_WRITE);
509 			return (EBUSY);
510 		}
511 	}
512 
513 	TMPFS_LOCK(tmp);
514 	while ((node = LIST_FIRST(&tmp->tm_nodes_used)) != NULL) {
515 		TMPFS_NODE_LOCK(node);
516 		if (node->tn_type == VDIR)
517 			tmpfs_dir_destroy(tmp, node);
518 		if (tmpfs_free_node_locked(tmp, node, true))
519 			TMPFS_LOCK(tmp);
520 		else
521 			TMPFS_NODE_UNLOCK(node);
522 	}
523 
524 	mp->mnt_data = NULL;
525 	tmpfs_free_tmp(tmp);
526 	vfs_write_resume(mp, VR_START_WRITE);
527 
528 	MNT_ILOCK(mp);
529 	mp->mnt_flag &= ~MNT_LOCAL;
530 	MNT_IUNLOCK(mp);
531 
532 	return (0);
533 }
534 
535 void
536 tmpfs_free_tmp(struct tmpfs_mount *tmp)
537 {
538 
539 	MPASS(tmp->tm_refcount > 0);
540 	tmp->tm_refcount--;
541 	if (tmp->tm_refcount > 0) {
542 		TMPFS_UNLOCK(tmp);
543 		return;
544 	}
545 	TMPFS_UNLOCK(tmp);
546 
547 	mtx_destroy(&tmp->tm_allnode_lock);
548 	MPASS(tmp->tm_pages_used == 0);
549 	MPASS(tmp->tm_nodes_inuse == 0);
550 
551 	free(tmp, M_TMPFSMNT);
552 }
553 
554 static int
555 tmpfs_root(struct mount *mp, int flags, struct vnode **vpp)
556 {
557 	int error;
558 
559 	error = tmpfs_alloc_vp(mp, VFS_TO_TMPFS(mp)->tm_root, flags, vpp);
560 	if (error == 0)
561 		(*vpp)->v_vflag |= VV_ROOT;
562 	return (error);
563 }
564 
565 static int
566 tmpfs_fhtovp(struct mount *mp, struct fid *fhp, int flags,
567     struct vnode **vpp)
568 {
569 	struct tmpfs_fid_data tfd;
570 	struct tmpfs_mount *tmp;
571 	struct tmpfs_node *node;
572 	int error;
573 
574 	if (fhp->fid_len != sizeof(tfd))
575 		return (EINVAL);
576 
577 	/*
578 	 * Copy from fid_data onto the stack to avoid unaligned pointer use.
579 	 * See the comment in sys/mount.h on struct fid for details.
580 	 */
581 	memcpy(&tfd, fhp->fid_data, fhp->fid_len);
582 
583 	tmp = VFS_TO_TMPFS(mp);
584 
585 	if (tfd.tfd_id >= tmp->tm_nodes_max)
586 		return (EINVAL);
587 
588 	TMPFS_LOCK(tmp);
589 	LIST_FOREACH(node, &tmp->tm_nodes_used, tn_entries) {
590 		if (node->tn_id == tfd.tfd_id &&
591 		    node->tn_gen == tfd.tfd_gen) {
592 			tmpfs_ref_node(node);
593 			break;
594 		}
595 	}
596 	TMPFS_UNLOCK(tmp);
597 
598 	if (node != NULL) {
599 		error = tmpfs_alloc_vp(mp, node, LK_EXCLUSIVE, vpp);
600 		tmpfs_free_node(tmp, node);
601 	} else
602 		error = EINVAL;
603 	return (error);
604 }
605 
606 /* ARGSUSED2 */
607 static int
608 tmpfs_statfs(struct mount *mp, struct statfs *sbp)
609 {
610 	struct tmpfs_mount *tmp;
611 	size_t used;
612 
613 	tmp = VFS_TO_TMPFS(mp);
614 
615 	sbp->f_iosize = PAGE_SIZE;
616 	sbp->f_bsize = PAGE_SIZE;
617 
618 	used = tmpfs_pages_used(tmp);
619 	if (tmp->tm_pages_max != ULONG_MAX)
620 		 sbp->f_blocks = tmp->tm_pages_max;
621 	else
622 		 sbp->f_blocks = used + tmpfs_mem_avail();
623 	if (sbp->f_blocks <= used)
624 		sbp->f_bavail = 0;
625 	else
626 		sbp->f_bavail = sbp->f_blocks - used;
627 	sbp->f_bfree = sbp->f_bavail;
628 	used = tmp->tm_nodes_inuse;
629 	sbp->f_files = tmp->tm_nodes_max;
630 	if (sbp->f_files <= used)
631 		sbp->f_ffree = 0;
632 	else
633 		sbp->f_ffree = sbp->f_files - used;
634 	/* sbp->f_owner = tmp->tn_uid; */
635 
636 	return 0;
637 }
638 
639 static int
640 tmpfs_sync(struct mount *mp, int waitfor)
641 {
642 
643 	if (waitfor == MNT_SUSPEND) {
644 		MNT_ILOCK(mp);
645 		mp->mnt_kern_flag |= MNTK_SUSPEND2 | MNTK_SUSPENDED;
646 		MNT_IUNLOCK(mp);
647 	} else if (waitfor == MNT_LAZY) {
648 		tmpfs_update_mtime(mp, true);
649 	}
650 	return (0);
651 }
652 
653 static int
654 tmpfs_init(struct vfsconf *conf)
655 {
656 	tmpfs_subr_init();
657 	return (0);
658 }
659 
660 static int
661 tmpfs_uninit(struct vfsconf *conf)
662 {
663 	tmpfs_subr_uninit();
664 	return (0);
665 }
666 
667 /*
668  * tmpfs vfs operations.
669  */
670 struct vfsops tmpfs_vfsops = {
671 	.vfs_mount =			tmpfs_mount,
672 	.vfs_unmount =			tmpfs_unmount,
673 	.vfs_root =			vfs_cache_root,
674 	.vfs_cachedroot =		tmpfs_root,
675 	.vfs_statfs =			tmpfs_statfs,
676 	.vfs_fhtovp =			tmpfs_fhtovp,
677 	.vfs_sync =			tmpfs_sync,
678 	.vfs_init =			tmpfs_init,
679 	.vfs_uninit =			tmpfs_uninit,
680 };
681 VFS_SET(tmpfs_vfsops, tmpfs, VFCF_JAIL);
682