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
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_ddb.h"
47 #include "opt_tmpfs.h"
48
49 #include <sys/param.h>
50 #include <sys/systm.h>
51 #include <sys/dirent.h>
52 #include <sys/file.h>
53 #include <sys/limits.h>
54 #include <sys/lock.h>
55 #include <sys/mount.h>
56 #include <sys/mutex.h>
57 #include <sys/proc.h>
58 #include <sys/jail.h>
59 #include <sys/kernel.h>
60 #include <sys/rwlock.h>
61 #include <sys/stat.h>
62 #include <sys/sx.h>
63 #include <sys/sysctl.h>
64 #include <sys/vnode.h>
65
66 #include <vm/vm.h>
67 #include <vm/vm_param.h>
68 #include <vm/pmap.h>
69 #include <vm/vm_extern.h>
70 #include <vm/vm_map.h>
71 #include <vm/vm_object.h>
72 #include <vm/vm_param.h>
73
74 #include <fs/tmpfs/tmpfs.h>
75
76 /*
77 * Default permission for root node
78 */
79 #define TMPFS_DEFAULT_ROOT_MODE (S_IRWXU|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH)
80
81 static MALLOC_DEFINE(M_TMPFSMNT, "tmpfs mount", "tmpfs mount structures");
82 MALLOC_DEFINE(M_TMPFSNAME, "tmpfs name", "tmpfs file names");
83
84 static int tmpfs_mount(struct mount *);
85 static int tmpfs_unmount(struct mount *, int);
86 static int tmpfs_root(struct mount *, int flags, struct vnode **);
87 static int tmpfs_fhtovp(struct mount *, struct fid *, int,
88 struct vnode **);
89 static int tmpfs_statfs(struct mount *, struct statfs *);
90
91 static const char *tmpfs_opts[] = {
92 "from", "easize", "size", "maxfilesize", "inodes", "uid", "gid", "mode",
93 "export", "union", "nonc", "nomtime", "nosymfollow", "pgread", NULL
94 };
95
96 static const char *tmpfs_updateopts[] = {
97 "from", "easize", "export", "nomtime", "size", "nosymfollow", NULL
98 };
99
100 static int
tmpfs_update_mtime_lazy_filter(struct vnode * vp,void * arg)101 tmpfs_update_mtime_lazy_filter(struct vnode *vp, void *arg)
102 {
103 struct vm_object *obj;
104
105 if (vp->v_type != VREG)
106 return (0);
107
108 obj = atomic_load_ptr(&vp->v_object);
109 if (obj == NULL)
110 return (0);
111
112 return (vm_object_mightbedirty_(obj));
113 }
114
115 static void
tmpfs_update_mtime_lazy(struct mount * mp)116 tmpfs_update_mtime_lazy(struct mount *mp)
117 {
118 struct vnode *vp, *mvp;
119
120 MNT_VNODE_FOREACH_LAZY(vp, mp, mvp, tmpfs_update_mtime_lazy_filter, NULL) {
121 if (vget(vp, LK_EXCLUSIVE | LK_INTERLOCK) != 0)
122 continue;
123 tmpfs_check_mtime(vp);
124 vput(vp);
125 }
126 }
127
128 static void
tmpfs_update_mtime_all(struct mount * mp)129 tmpfs_update_mtime_all(struct mount *mp)
130 {
131 struct vnode *vp, *mvp;
132
133 if (VFS_TO_TMPFS(mp)->tm_nomtime)
134 return;
135 MNT_VNODE_FOREACH_ALL(vp, mp, mvp) {
136 if (vp->v_type != VREG) {
137 VI_UNLOCK(vp);
138 continue;
139 }
140 if (vget(vp, LK_EXCLUSIVE | LK_INTERLOCK) != 0)
141 continue;
142 tmpfs_check_mtime(vp);
143 tmpfs_update(vp);
144 vput(vp);
145 }
146 }
147
148 struct tmpfs_check_rw_maps_arg {
149 bool found;
150 };
151
152 static bool
tmpfs_check_rw_maps_cb(struct mount * mp __unused,vm_map_t map __unused,vm_map_entry_t entry __unused,void * arg)153 tmpfs_check_rw_maps_cb(struct mount *mp __unused, vm_map_t map __unused,
154 vm_map_entry_t entry __unused, void *arg)
155 {
156 struct tmpfs_check_rw_maps_arg *a;
157
158 a = arg;
159 a->found = true;
160 return (true);
161 }
162
163 /*
164 * Revoke write permissions from all mappings of regular files
165 * belonging to the specified tmpfs mount.
166 */
167 static bool
tmpfs_revoke_rw_maps_cb(struct mount * mp __unused,vm_map_t map,vm_map_entry_t entry,void * arg __unused)168 tmpfs_revoke_rw_maps_cb(struct mount *mp __unused, vm_map_t map,
169 vm_map_entry_t entry, void *arg __unused)
170 {
171
172 /*
173 * XXXKIB: might be invalidate the mapping
174 * instead ? The process is not going to be
175 * happy in any case.
176 */
177 entry->max_protection &= ~VM_PROT_WRITE;
178 if ((entry->protection & VM_PROT_WRITE) != 0) {
179 entry->protection &= ~VM_PROT_WRITE;
180 pmap_protect(map->pmap, entry->start, entry->end,
181 entry->protection);
182 }
183 return (false);
184 }
185
186 static void
tmpfs_all_rw_maps(struct mount * mp,bool (* cb)(struct mount * mp,vm_map_t,vm_map_entry_t,void *),void * cb_arg)187 tmpfs_all_rw_maps(struct mount *mp, bool (*cb)(struct mount *mp, vm_map_t,
188 vm_map_entry_t, void *), void *cb_arg)
189 {
190 struct proc *p;
191 struct vmspace *vm;
192 vm_map_t map;
193 vm_map_entry_t entry;
194 vm_object_t object;
195 struct vnode *vp;
196 int gen;
197 bool terminate;
198
199 terminate = false;
200 sx_slock(&allproc_lock);
201 again:
202 gen = allproc_gen;
203 FOREACH_PROC_IN_SYSTEM(p) {
204 PROC_LOCK(p);
205 if (p->p_state != PRS_NORMAL || (p->p_flag & (P_INEXEC |
206 P_SYSTEM | P_WEXIT)) != 0) {
207 PROC_UNLOCK(p);
208 continue;
209 }
210 vm = vmspace_acquire_ref(p);
211 _PHOLD_LITE(p);
212 PROC_UNLOCK(p);
213 if (vm == NULL) {
214 PRELE(p);
215 continue;
216 }
217 sx_sunlock(&allproc_lock);
218 map = &vm->vm_map;
219
220 vm_map_lock(map);
221 if (map->busy)
222 vm_map_wait_busy(map);
223 VM_MAP_ENTRY_FOREACH(entry, map) {
224 if ((entry->eflags & (MAP_ENTRY_GUARD |
225 MAP_ENTRY_IS_SUB_MAP | MAP_ENTRY_COW)) != 0 ||
226 (entry->max_protection & VM_PROT_WRITE) == 0)
227 continue;
228 object = entry->object.vm_object;
229 if (object == NULL || object->type != tmpfs_pager_type)
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) == 0) {
243 VM_OBJECT_RUNLOCK(object);
244 continue;
245 }
246 vp = VM_TO_TMPFS_VP(object);
247 if (vp->v_mount != mp) {
248 VM_OBJECT_RUNLOCK(object);
249 continue;
250 }
251
252 terminate = cb(mp, map, entry, cb_arg);
253 VM_OBJECT_RUNLOCK(object);
254 if (terminate)
255 break;
256 }
257 vm_map_unlock(map);
258
259 vmspace_free(vm);
260 sx_slock(&allproc_lock);
261 PRELE(p);
262 if (terminate)
263 break;
264 }
265 if (!terminate && gen != allproc_gen)
266 goto again;
267 sx_sunlock(&allproc_lock);
268 }
269
270 static bool
tmpfs_check_rw_maps(struct mount * mp)271 tmpfs_check_rw_maps(struct mount *mp)
272 {
273 struct tmpfs_check_rw_maps_arg ca;
274
275 ca.found = false;
276 tmpfs_all_rw_maps(mp, tmpfs_check_rw_maps_cb, &ca);
277 return (ca.found);
278 }
279
280 static int
tmpfs_rw_to_ro(struct mount * mp)281 tmpfs_rw_to_ro(struct mount *mp)
282 {
283 int error, flags;
284 bool forced;
285
286 forced = (mp->mnt_flag & MNT_FORCE) != 0;
287 flags = WRITECLOSE | (forced ? FORCECLOSE : 0);
288
289 if ((error = vn_start_write(NULL, &mp, V_WAIT)) != 0)
290 return (error);
291 error = vfs_write_suspend_umnt(mp);
292 if (error != 0)
293 return (error);
294 if (!forced && tmpfs_check_rw_maps(mp)) {
295 error = EBUSY;
296 goto out;
297 }
298 VFS_TO_TMPFS(mp)->tm_ronly = 1;
299 MNT_ILOCK(mp);
300 mp->mnt_flag |= MNT_RDONLY;
301 MNT_IUNLOCK(mp);
302 for (;;) {
303 tmpfs_all_rw_maps(mp, tmpfs_revoke_rw_maps_cb, NULL);
304 tmpfs_update_mtime_all(mp);
305 error = vflush(mp, 0, flags, curthread);
306 if (error != 0) {
307 VFS_TO_TMPFS(mp)->tm_ronly = 0;
308 MNT_ILOCK(mp);
309 mp->mnt_flag &= ~MNT_RDONLY;
310 MNT_IUNLOCK(mp);
311 goto out;
312 }
313 if (!tmpfs_check_rw_maps(mp))
314 break;
315 }
316 out:
317 vfs_write_resume(mp, 0);
318 return (error);
319 }
320
321 static int
tmpfs_mount(struct mount * mp)322 tmpfs_mount(struct mount *mp)
323 {
324 const size_t nodes_per_page = howmany(PAGE_SIZE,
325 sizeof(struct tmpfs_dirent) + sizeof(struct tmpfs_node));
326 struct tmpfs_mount *tmp;
327 struct tmpfs_node *root;
328 int error;
329 bool nomtime, nonc, pgread;
330 /* Size counters. */
331 u_quad_t pages;
332 off_t nodes_max, size_max, maxfilesize, ea_max_size;
333
334 /* Root node attributes. */
335 uid_t root_uid;
336 gid_t root_gid;
337 mode_t root_mode;
338
339 struct vattr va;
340
341 if (vfs_filteropt(mp->mnt_optnew, tmpfs_opts))
342 return (EINVAL);
343
344 if (mp->mnt_flag & MNT_UPDATE) {
345 /* Only support update mounts for certain options. */
346 if (vfs_filteropt(mp->mnt_optnew, tmpfs_updateopts) != 0)
347 return (EOPNOTSUPP);
348 tmp = VFS_TO_TMPFS(mp);
349 if (vfs_getopt_size(mp->mnt_optnew, "size", &size_max) == 0) {
350 /*
351 * On-the-fly resizing is not supported (yet). We still
352 * need to have "size" listed as "supported", otherwise
353 * trying to update fs that is listed in fstab with size
354 * parameter, say trying to change rw to ro or vice
355 * versa, would cause vfs_filteropt() to bail.
356 */
357 if (size_max != tmp->tm_size_max)
358 return (EOPNOTSUPP);
359 }
360 if (vfs_getopt_size(mp->mnt_optnew, "easize", &ea_max_size) == 0) {
361 tmp->tm_ea_memory_max = ea_max_size;
362 }
363 if (vfs_flagopt(mp->mnt_optnew, "ro", NULL, 0) &&
364 !tmp->tm_ronly) {
365 /* RW -> RO */
366 return (tmpfs_rw_to_ro(mp));
367 } else if (!vfs_flagopt(mp->mnt_optnew, "ro", NULL, 0) &&
368 tmp->tm_ronly) {
369 /* RO -> RW */
370 tmp->tm_ronly = 0;
371 MNT_ILOCK(mp);
372 mp->mnt_flag &= ~MNT_RDONLY;
373 MNT_IUNLOCK(mp);
374 }
375 tmp->tm_nomtime = vfs_getopt(mp->mnt_optnew, "nomtime", NULL,
376 0) == 0;
377 MNT_ILOCK(mp);
378 if ((mp->mnt_flag & MNT_UNION) == 0) {
379 mp->mnt_kern_flag |= MNTK_FPLOOKUP;
380 } else {
381 mp->mnt_kern_flag &= ~MNTK_FPLOOKUP;
382 }
383 MNT_IUNLOCK(mp);
384 return (0);
385 }
386
387 vn_lock(mp->mnt_vnodecovered, LK_SHARED | LK_RETRY);
388 error = VOP_GETATTR(mp->mnt_vnodecovered, &va, mp->mnt_cred);
389 VOP_UNLOCK(mp->mnt_vnodecovered);
390 if (error)
391 return (error);
392
393 if (mp->mnt_cred->cr_ruid != 0 ||
394 vfs_scanopt(mp->mnt_optnew, "gid", "%d", &root_gid) != 1)
395 root_gid = va.va_gid;
396 if (mp->mnt_cred->cr_ruid != 0 ||
397 vfs_scanopt(mp->mnt_optnew, "uid", "%d", &root_uid) != 1)
398 root_uid = va.va_uid;
399 if (mp->mnt_cred->cr_ruid != 0 ||
400 vfs_scanopt(mp->mnt_optnew, "mode", "%ho", &root_mode) != 1)
401 root_mode = va.va_mode;
402 if (vfs_getopt_size(mp->mnt_optnew, "inodes", &nodes_max) != 0)
403 nodes_max = 0;
404 if (vfs_getopt_size(mp->mnt_optnew, "size", &size_max) != 0)
405 size_max = 0;
406 if (vfs_getopt_size(mp->mnt_optnew, "maxfilesize", &maxfilesize) != 0)
407 maxfilesize = 0;
408 if (vfs_getopt_size(mp->mnt_optnew, "easize", &ea_max_size) != 0)
409 ea_max_size = 0;
410 nonc = vfs_getopt(mp->mnt_optnew, "nonc", NULL, NULL) == 0;
411 nomtime = vfs_getopt(mp->mnt_optnew, "nomtime", NULL, NULL) == 0;
412 pgread = vfs_getopt(mp->mnt_optnew, "pgread", NULL, NULL) == 0;
413
414 /* Do not allow mounts if we do not have enough memory to preserve
415 * the minimum reserved pages. */
416 if (tmpfs_mem_avail() < TMPFS_PAGES_MINRESERVED)
417 return (ENOSPC);
418
419 /* Get the maximum number of memory pages this file system is
420 * allowed to use, based on the maximum size the user passed in
421 * the mount structure. A value of zero is treated as if the
422 * maximum available space was requested. */
423 if (size_max == 0 || size_max > OFF_MAX - PAGE_SIZE ||
424 (SIZE_MAX < OFF_MAX && size_max / PAGE_SIZE >= SIZE_MAX))
425 pages = SIZE_MAX;
426 else {
427 size_max = roundup(size_max, PAGE_SIZE);
428 pages = howmany(size_max, PAGE_SIZE);
429 }
430 MPASS(pages > 0);
431
432 if (nodes_max <= 3) {
433 if (pages < INT_MAX / nodes_per_page)
434 nodes_max = pages * nodes_per_page;
435 else
436 nodes_max = INT_MAX;
437 }
438 if (nodes_max > INT_MAX)
439 nodes_max = INT_MAX;
440 MPASS(nodes_max >= 3);
441
442 /* Allocate the tmpfs mount structure and fill it. */
443 tmp = (struct tmpfs_mount *)malloc(sizeof(struct tmpfs_mount),
444 M_TMPFSMNT, M_WAITOK | M_ZERO);
445
446 mtx_init(&tmp->tm_allnode_lock, "tmpfs allnode lock", NULL, MTX_DEF);
447 tmp->tm_nodes_max = nodes_max;
448 tmp->tm_nodes_inuse = 0;
449 tmp->tm_ea_memory_inuse = 0;
450 tmp->tm_refcount = 1;
451 tmp->tm_maxfilesize = maxfilesize > 0 ? maxfilesize : OFF_MAX;
452 tmp->tm_ea_memory_max = ea_max_size > 0 ?
453 ea_max_size : TMPFS_EA_MEMORY_RESERVED;
454 LIST_INIT(&tmp->tm_nodes_used);
455
456 tmp->tm_size_max = size_max;
457 tmp->tm_pages_max = pages;
458 tmp->tm_pages_used = 0;
459 new_unrhdr64(&tmp->tm_ino_unr, 2);
460 tmp->tm_ronly = (mp->mnt_flag & MNT_RDONLY) != 0;
461 tmp->tm_nonc = nonc;
462 tmp->tm_nomtime = nomtime;
463 tmp->tm_pgread = pgread;
464
465 /* Allocate the root node. */
466 error = tmpfs_alloc_node(mp, tmp, VDIR, root_uid, root_gid,
467 root_mode & ALLPERMS, NULL, NULL, VNOVAL, &root);
468
469 if (error != 0 || root == NULL) {
470 free(tmp, M_TMPFSMNT);
471 return (error);
472 }
473 KASSERT(root->tn_id == 2,
474 ("tmpfs root with invalid ino: %ju", (uintmax_t)root->tn_id));
475 tmp->tm_root = root;
476
477 MNT_ILOCK(mp);
478 mp->mnt_flag |= MNT_LOCAL;
479 mp->mnt_kern_flag |= MNTK_LOOKUP_SHARED | MNTK_EXTENDED_SHARED |
480 MNTK_NOMSYNC;
481 if (!nonc && (mp->mnt_flag & MNT_UNION) == 0)
482 mp->mnt_kern_flag |= MNTK_FPLOOKUP;
483 MNT_IUNLOCK(mp);
484
485 mp->mnt_data = tmp;
486 mp->mnt_stat.f_namemax = MAXNAMLEN;
487 vfs_getnewfsid(mp);
488 vfs_mountedfrom(mp, "tmpfs");
489
490 return (0);
491 }
492
493 /* ARGSUSED2 */
494 static int
tmpfs_unmount(struct mount * mp,int mntflags)495 tmpfs_unmount(struct mount *mp, int mntflags)
496 {
497 struct tmpfs_mount *tmp;
498 struct tmpfs_node *node;
499 int error, flags;
500
501 flags = (mntflags & MNT_FORCE) != 0 ? FORCECLOSE : 0;
502 tmp = VFS_TO_TMPFS(mp);
503
504 /* Stop writers */
505 error = vfs_write_suspend_umnt(mp);
506 if (error != 0)
507 return (error);
508 /*
509 * At this point, nodes cannot be destroyed by any other
510 * thread because write suspension is started.
511 */
512
513 for (;;) {
514 error = vflush(mp, 0, flags, curthread);
515 if (error != 0) {
516 vfs_write_resume(mp, VR_START_WRITE);
517 return (error);
518 }
519 MNT_ILOCK(mp);
520 if (mp->mnt_nvnodelistsize == 0) {
521 MNT_IUNLOCK(mp);
522 break;
523 }
524 MNT_IUNLOCK(mp);
525 if ((mntflags & MNT_FORCE) == 0) {
526 vfs_write_resume(mp, VR_START_WRITE);
527 return (EBUSY);
528 }
529 }
530
531 TMPFS_LOCK(tmp);
532 while ((node = LIST_FIRST(&tmp->tm_nodes_used)) != NULL) {
533 TMPFS_NODE_LOCK(node);
534 if (node->tn_type == VDIR)
535 tmpfs_dir_destroy(tmp, node);
536 if (tmpfs_free_node_locked(tmp, node, true))
537 TMPFS_LOCK(tmp);
538 else
539 TMPFS_NODE_UNLOCK(node);
540 }
541
542 mp->mnt_data = NULL;
543 tmpfs_free_tmp(tmp);
544 vfs_write_resume(mp, VR_START_WRITE);
545
546 return (0);
547 }
548
549 void
tmpfs_free_tmp(struct tmpfs_mount * tmp)550 tmpfs_free_tmp(struct tmpfs_mount *tmp)
551 {
552 TMPFS_MP_ASSERT_LOCKED(tmp);
553 MPASS(tmp->tm_refcount > 0);
554
555 tmp->tm_refcount--;
556 if (tmp->tm_refcount > 0) {
557 TMPFS_UNLOCK(tmp);
558 return;
559 }
560 TMPFS_UNLOCK(tmp);
561
562 mtx_destroy(&tmp->tm_allnode_lock);
563 /*
564 * We cannot assert that tmp->tm_pages_used == 0 there,
565 * because tmpfs vm_objects might be still mapped by some
566 * process and outlive the mount due to reference counting.
567 */
568 MPASS(tmp->tm_nodes_inuse == 0);
569
570 free(tmp, M_TMPFSMNT);
571 }
572
573 static int
tmpfs_root(struct mount * mp,int flags,struct vnode ** vpp)574 tmpfs_root(struct mount *mp, int flags, struct vnode **vpp)
575 {
576 int error;
577
578 error = tmpfs_alloc_vp(mp, VFS_TO_TMPFS(mp)->tm_root, flags, vpp);
579 if (error == 0)
580 (*vpp)->v_vflag |= VV_ROOT;
581 return (error);
582 }
583
584 static int
tmpfs_fhtovp(struct mount * mp,struct fid * fhp,int flags,struct vnode ** vpp)585 tmpfs_fhtovp(struct mount *mp, struct fid *fhp, int flags,
586 struct vnode **vpp)
587 {
588 struct tmpfs_fid_data tfd;
589 struct tmpfs_mount *tmp;
590 struct tmpfs_node *node;
591 int error;
592
593 if (fhp->fid_len != sizeof(tfd))
594 return (EINVAL);
595
596 /*
597 * Copy from fid_data onto the stack to avoid unaligned pointer use.
598 * See the comment in sys/mount.h on struct fid for details.
599 */
600 memcpy(&tfd, fhp->fid_data, fhp->fid_len);
601
602 tmp = VFS_TO_TMPFS(mp);
603
604 if (tfd.tfd_id >= tmp->tm_nodes_max)
605 return (EINVAL);
606
607 TMPFS_LOCK(tmp);
608 LIST_FOREACH(node, &tmp->tm_nodes_used, tn_entries) {
609 if (node->tn_id == tfd.tfd_id &&
610 node->tn_gen == tfd.tfd_gen) {
611 tmpfs_ref_node(node);
612 break;
613 }
614 }
615 TMPFS_UNLOCK(tmp);
616
617 if (node != NULL) {
618 error = tmpfs_alloc_vp(mp, node, LK_EXCLUSIVE, vpp);
619 tmpfs_free_node(tmp, node);
620 } else
621 error = EINVAL;
622 return (error);
623 }
624
625 /* ARGSUSED2 */
626 static int
tmpfs_statfs(struct mount * mp,struct statfs * sbp)627 tmpfs_statfs(struct mount *mp, struct statfs *sbp)
628 {
629 struct tmpfs_mount *tmp;
630 size_t used;
631
632 tmp = VFS_TO_TMPFS(mp);
633
634 sbp->f_iosize = PAGE_SIZE;
635 sbp->f_bsize = PAGE_SIZE;
636
637 used = tmpfs_pages_used(tmp);
638 if (tmp->tm_pages_max != ULONG_MAX)
639 sbp->f_blocks = tmp->tm_pages_max;
640 else
641 sbp->f_blocks = used + tmpfs_mem_avail();
642 if (sbp->f_blocks <= used)
643 sbp->f_bavail = 0;
644 else
645 sbp->f_bavail = sbp->f_blocks - used;
646 sbp->f_bfree = sbp->f_bavail;
647 used = tmp->tm_nodes_inuse;
648 sbp->f_files = tmp->tm_nodes_max;
649 if (sbp->f_files <= used)
650 sbp->f_ffree = 0;
651 else
652 sbp->f_ffree = sbp->f_files - used;
653 /* sbp->f_owner = tmp->tn_uid; */
654
655 return (0);
656 }
657
658 static int
tmpfs_sync(struct mount * mp,int waitfor)659 tmpfs_sync(struct mount *mp, int waitfor)
660 {
661
662 if (waitfor == MNT_SUSPEND) {
663 MNT_ILOCK(mp);
664 mp->mnt_kern_flag |= MNTK_SUSPEND2 | MNTK_SUSPENDED;
665 MNT_IUNLOCK(mp);
666 } else if (waitfor == MNT_LAZY) {
667 tmpfs_update_mtime_lazy(mp);
668 }
669 return (0);
670 }
671
672 static int
tmpfs_init(struct vfsconf * conf)673 tmpfs_init(struct vfsconf *conf)
674 {
675 int res;
676
677 res = tmpfs_subr_init();
678 if (res != 0)
679 return (res);
680 memcpy(&tmpfs_fnops, &vnops, sizeof(struct fileops));
681 tmpfs_fnops.fo_close = tmpfs_fo_close;
682 return (0);
683 }
684
685 static int
tmpfs_uninit(struct vfsconf * conf)686 tmpfs_uninit(struct vfsconf *conf)
687 {
688 tmpfs_subr_uninit();
689 return (0);
690 }
691
692 /*
693 * tmpfs vfs operations.
694 */
695 struct vfsops tmpfs_vfsops = {
696 .vfs_mount = tmpfs_mount,
697 .vfs_unmount = tmpfs_unmount,
698 .vfs_root = vfs_cache_root,
699 .vfs_cachedroot = tmpfs_root,
700 .vfs_statfs = tmpfs_statfs,
701 .vfs_fhtovp = tmpfs_fhtovp,
702 .vfs_sync = tmpfs_sync,
703 .vfs_init = tmpfs_init,
704 .vfs_uninit = tmpfs_uninit,
705 };
706 VFS_SET(tmpfs_vfsops, tmpfs, VFCF_JAIL);
707
708 #ifdef DDB
709 #include <ddb/ddb.h>
710
711 static void
db_print_tmpfs(struct mount * mp,struct tmpfs_mount * tmp)712 db_print_tmpfs(struct mount *mp, struct tmpfs_mount *tmp)
713 {
714 db_printf("mp %p (%s) tmp %p\n", mp,
715 mp->mnt_stat.f_mntonname, tmp);
716 db_printf(
717 "\tsize max %ju pages max %lu pages used %lu\n"
718 "\tinodes max %ju inodes inuse %ju ea inuse %ju refcount %ju\n"
719 "\tmaxfilesize %ju r%c %snamecache %smtime\n",
720 (uintmax_t)tmp->tm_size_max, tmp->tm_pages_max, tmp->tm_pages_used,
721 (uintmax_t)tmp->tm_nodes_max, (uintmax_t)tmp->tm_nodes_inuse,
722 (uintmax_t)tmp->tm_ea_memory_inuse, (uintmax_t)tmp->tm_refcount,
723 (uintmax_t)tmp->tm_maxfilesize,
724 tmp->tm_ronly ? 'o' : 'w', tmp->tm_nonc ? "no" : "",
725 tmp->tm_nomtime ? "no" : "");
726 }
727
DB_SHOW_COMMAND(tmpfs,db_show_tmpfs)728 DB_SHOW_COMMAND(tmpfs, db_show_tmpfs)
729 {
730 struct mount *mp;
731 struct tmpfs_mount *tmp;
732
733 if (have_addr) {
734 mp = (struct mount *)addr;
735 tmp = VFS_TO_TMPFS(mp);
736 db_print_tmpfs(mp, tmp);
737 return;
738 }
739
740 TAILQ_FOREACH(mp, &mountlist, mnt_list) {
741 if (strcmp(mp->mnt_stat.f_fstypename, tmpfs_vfsconf.vfc_name) ==
742 0) {
743 tmp = VFS_TO_TMPFS(mp);
744 db_print_tmpfs(mp, tmp);
745 }
746 }
747 }
748 #endif /* DDB */
749