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 int
tmpfs_update_mtime_lazy_filter(struct vnode * vp,void * arg)97 tmpfs_update_mtime_lazy_filter(struct vnode *vp, void *arg)
98 {
99 struct vm_object *obj;
100
101 if (vp->v_type != VREG)
102 return (0);
103
104 obj = atomic_load_ptr(&vp->v_object);
105 if (obj == NULL)
106 return (0);
107
108 return (vm_object_mightbedirty_(obj));
109 }
110
111 static void
tmpfs_update_mtime_lazy(struct mount * mp)112 tmpfs_update_mtime_lazy(struct mount *mp)
113 {
114 struct vnode *vp, *mvp;
115
116 MNT_VNODE_FOREACH_LAZY(vp, mp, mvp, tmpfs_update_mtime_lazy_filter, NULL) {
117 if (vget(vp, LK_EXCLUSIVE | LK_INTERLOCK) != 0)
118 continue;
119 tmpfs_check_mtime(vp);
120 vput(vp);
121 }
122 }
123
124 static void
tmpfs_update_mtime_all(struct mount * mp)125 tmpfs_update_mtime_all(struct mount *mp)
126 {
127 struct vnode *vp, *mvp;
128
129 if (VFS_TO_TMPFS(mp)->tm_nomtime)
130 return;
131 MNT_VNODE_FOREACH_ALL(vp, mp, mvp) {
132 if (vp->v_type != VREG) {
133 VI_UNLOCK(vp);
134 continue;
135 }
136 if (vget(vp, LK_EXCLUSIVE | LK_INTERLOCK) != 0)
137 continue;
138 tmpfs_check_mtime(vp);
139 tmpfs_update(vp);
140 vput(vp);
141 }
142 }
143
144 struct tmpfs_check_rw_maps_arg {
145 bool found;
146 };
147
148 static bool
tmpfs_check_rw_maps_cb(struct mount * mp __unused,vm_map_t map __unused,vm_map_entry_t entry __unused,void * arg)149 tmpfs_check_rw_maps_cb(struct mount *mp __unused, vm_map_t map __unused,
150 vm_map_entry_t entry __unused, void *arg)
151 {
152 struct tmpfs_check_rw_maps_arg *a;
153
154 a = arg;
155 a->found = true;
156 return (true);
157 }
158
159 /*
160 * Revoke write permissions from all mappings of regular files
161 * belonging to the specified tmpfs mount.
162 */
163 static bool
tmpfs_revoke_rw_maps_cb(struct mount * mp __unused,vm_map_t map,vm_map_entry_t entry,void * arg __unused)164 tmpfs_revoke_rw_maps_cb(struct mount *mp __unused, vm_map_t map,
165 vm_map_entry_t entry, void *arg __unused)
166 {
167
168 /*
169 * XXXKIB: might be invalidate the mapping
170 * instead ? The process is not going to be
171 * happy in any case.
172 */
173 entry->max_protection &= ~VM_PROT_WRITE;
174 if ((entry->protection & VM_PROT_WRITE) != 0) {
175 entry->protection &= ~VM_PROT_WRITE;
176 pmap_protect(map->pmap, entry->start, entry->end,
177 entry->protection);
178 }
179 return (false);
180 }
181
182 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)183 tmpfs_all_rw_maps(struct mount *mp, bool (*cb)(struct mount *mp, vm_map_t,
184 vm_map_entry_t, void *), void *cb_arg)
185 {
186 struct proc *p;
187 struct vmspace *vm;
188 vm_map_t map;
189 vm_map_entry_t entry;
190 vm_object_t object;
191 struct vnode *vp;
192 int gen;
193 bool terminate;
194
195 terminate = false;
196 sx_slock(&allproc_lock);
197 again:
198 gen = allproc_gen;
199 FOREACH_PROC_IN_SYSTEM(p) {
200 PROC_LOCK(p);
201 if (p->p_state != PRS_NORMAL || (p->p_flag & (P_INEXEC |
202 P_SYSTEM | P_WEXIT)) != 0) {
203 PROC_UNLOCK(p);
204 continue;
205 }
206 vm = vmspace_acquire_ref(p);
207 _PHOLD(p);
208 PROC_UNLOCK(p);
209 if (vm == NULL) {
210 PRELE(p);
211 continue;
212 }
213 sx_sunlock(&allproc_lock);
214 map = &vm->vm_map;
215
216 vm_map_lock(map);
217 if (map->busy)
218 vm_map_wait_busy(map);
219 VM_MAP_ENTRY_FOREACH(entry, map) {
220 if ((entry->eflags & (MAP_ENTRY_GUARD |
221 MAP_ENTRY_IS_SUB_MAP | MAP_ENTRY_COW)) != 0 ||
222 (entry->max_protection & VM_PROT_WRITE) == 0)
223 continue;
224 object = entry->object.vm_object;
225 if (object == NULL || object->type != tmpfs_pager_type)
226 continue;
227 /*
228 * No need to dig into shadow chain, mapping
229 * of the object not at top is readonly.
230 */
231
232 VM_OBJECT_RLOCK(object);
233 if (object->type == OBJT_DEAD) {
234 VM_OBJECT_RUNLOCK(object);
235 continue;
236 }
237 MPASS(object->ref_count > 1);
238 if ((object->flags & OBJ_TMPFS) == 0) {
239 VM_OBJECT_RUNLOCK(object);
240 continue;
241 }
242 vp = VM_TO_TMPFS_VP(object);
243 if (vp->v_mount != mp) {
244 VM_OBJECT_RUNLOCK(object);
245 continue;
246 }
247
248 terminate = cb(mp, map, entry, cb_arg);
249 VM_OBJECT_RUNLOCK(object);
250 if (terminate)
251 break;
252 }
253 vm_map_unlock(map);
254
255 vmspace_free(vm);
256 sx_slock(&allproc_lock);
257 PRELE(p);
258 if (terminate)
259 break;
260 }
261 if (!terminate && gen != allproc_gen)
262 goto again;
263 sx_sunlock(&allproc_lock);
264 }
265
266 static bool
tmpfs_check_rw_maps(struct mount * mp)267 tmpfs_check_rw_maps(struct mount *mp)
268 {
269 struct tmpfs_check_rw_maps_arg ca;
270
271 ca.found = false;
272 tmpfs_all_rw_maps(mp, tmpfs_check_rw_maps_cb, &ca);
273 return (ca.found);
274 }
275
276 static int
tmpfs_rw_to_ro(struct mount * mp)277 tmpfs_rw_to_ro(struct mount *mp)
278 {
279 int error, flags;
280 bool forced;
281
282 forced = (mp->mnt_flag & MNT_FORCE) != 0;
283 flags = WRITECLOSE | (forced ? FORCECLOSE : 0);
284
285 if ((error = vn_start_write(NULL, &mp, V_WAIT)) != 0)
286 return (error);
287 error = vfs_write_suspend_umnt(mp);
288 if (error != 0)
289 return (error);
290 if (!forced && tmpfs_check_rw_maps(mp)) {
291 error = EBUSY;
292 goto out;
293 }
294 VFS_TO_TMPFS(mp)->tm_ronly = 1;
295 MNT_ILOCK(mp);
296 mp->mnt_flag |= MNT_RDONLY;
297 MNT_IUNLOCK(mp);
298 for (;;) {
299 tmpfs_all_rw_maps(mp, tmpfs_revoke_rw_maps_cb, NULL);
300 tmpfs_update_mtime_all(mp);
301 error = vflush(mp, 0, flags, curthread);
302 if (error != 0) {
303 VFS_TO_TMPFS(mp)->tm_ronly = 0;
304 MNT_ILOCK(mp);
305 mp->mnt_flag &= ~MNT_RDONLY;
306 MNT_IUNLOCK(mp);
307 goto out;
308 }
309 if (!tmpfs_check_rw_maps(mp))
310 break;
311 }
312 out:
313 vfs_write_resume(mp, 0);
314 return (error);
315 }
316
317 static int
tmpfs_mount(struct mount * mp)318 tmpfs_mount(struct mount *mp)
319 {
320 const size_t nodes_per_page = howmany(PAGE_SIZE,
321 sizeof(struct tmpfs_dirent) + sizeof(struct tmpfs_node));
322 struct tmpfs_mount *tmp;
323 struct tmpfs_node *root;
324 struct vfsoptlist *opts;
325 int error;
326 bool nomtime, nonc, pgread;
327 /* Size counters. */
328 u_quad_t pages;
329 off_t nodes_max, size_max, maxfilesize, ea_max_size;
330
331 /* Root node attributes. */
332 uid_t root_uid;
333 gid_t root_gid;
334 mode_t root_mode;
335
336 struct vattr va;
337
338 opts = mp->mnt_optnew;
339 if (vfs_filteropt(opts, tmpfs_opts))
340 return (EINVAL);
341
342 if (mp->mnt_flag & MNT_UPDATE) {
343 tmp = VFS_TO_TMPFS(mp);
344
345 /*
346 * These options cannot (yet) be modified on the fly, but
347 * mount(8) will still pass them when remounting, so we
348 * will silently ignore them as long as the value is
349 * unchanged.
350 */
351 if (vfs_scanopt(opts, "gid", "%d", &root_gid) == 1 &&
352 root_gid != tmp->tm_root->tn_gid)
353 return (EOPNOTSUPP);
354 if (vfs_scanopt(opts, "uid", "%d", &root_uid) == 1 &&
355 root_uid != tmp->tm_root->tn_uid)
356 return (EOPNOTSUPP);
357 if (vfs_scanopt(opts, "mode", "%ho", &root_mode) == 1 &&
358 (root_mode & S_IFMT) != (tmp->tm_root->tn_mode & S_IFMT))
359 return (EOPNOTSUPP);
360 if (vfs_getopt_size(opts, "inodes", &nodes_max) == 0 &&
361 nodes_max != 0 && nodes_max != tmp->tm_nodes_max)
362 return (EOPNOTSUPP);
363 if (vfs_getopt_size(opts, "size", &size_max) == 0 &&
364 size_max != 0 && size_max != tmp->tm_size_max)
365 return (EOPNOTSUPP);
366 if (vfs_getopt_size(opts, "maxfilesize", &maxfilesize) == 0 &&
367 maxfilesize != 0 && maxfilesize != tmp->tm_maxfilesize)
368 return (EOPNOTSUPP);
369 if (tmp->tm_nonc !=
370 (vfs_getopt(opts, "nonc", NULL, NULL) == 0))
371 return (EOPNOTSUPP);
372 if (tmp->tm_pgread !=
373 (vfs_getopt(opts, "pgread", NULL, NULL) == 0))
374 return (EOPNOTSUPP);
375
376 /*
377 * These options can be modified.
378 */
379 if (vfs_getopt_size(opts, "easize", &ea_max_size) != 0)
380 tmp->tm_ea_memory_max = ea_max_size;
381 tmp->tm_nomtime = (vfs_getopt(opts, "nomtime", NULL, 0) == 0);
382
383 /*
384 * Handle read-write to read-only or vice versa.
385 */
386 if (vfs_flagopt(opts, "ro", NULL, 0) && !tmp->tm_ronly) {
387 /* RW -> RO */
388 return (tmpfs_rw_to_ro(mp));
389 }
390 if (!vfs_flagopt(opts, "ro", NULL, 0) && tmp->tm_ronly) {
391 /* RO -> RW */
392 tmp->tm_ronly = 0;
393 MNT_ILOCK(mp);
394 mp->mnt_flag &= ~MNT_RDONLY;
395 MNT_IUNLOCK(mp);
396 }
397
398 /*
399 * Check if fast path lookup is still supported.
400 */
401 MNT_ILOCK(mp);
402 if (!tmp->tm_nonc && (mp->mnt_flag & MNT_UNION) == 0) {
403 mp->mnt_kern_flag |= MNTK_FPLOOKUP;
404 } else {
405 mp->mnt_kern_flag &= ~MNTK_FPLOOKUP;
406 }
407 MNT_IUNLOCK(mp);
408 return (0);
409 }
410
411 vn_lock(mp->mnt_vnodecovered, LK_SHARED | LK_RETRY);
412 error = VOP_GETATTR(mp->mnt_vnodecovered, &va, mp->mnt_cred);
413 VOP_UNLOCK(mp->mnt_vnodecovered);
414 if (error)
415 return (error);
416
417 if (mp->mnt_cred->cr_ruid != 0 ||
418 vfs_scanopt(opts, "gid", "%d", &root_gid) != 1)
419 root_gid = va.va_gid;
420 if (mp->mnt_cred->cr_ruid != 0 ||
421 vfs_scanopt(opts, "uid", "%d", &root_uid) != 1)
422 root_uid = va.va_uid;
423 if (mp->mnt_cred->cr_ruid != 0 ||
424 vfs_scanopt(opts, "mode", "%ho", &root_mode) != 1)
425 root_mode = va.va_mode;
426 if (vfs_getopt_size(opts, "inodes", &nodes_max) != 0)
427 nodes_max = 0;
428 if (vfs_getopt_size(opts, "size", &size_max) != 0)
429 size_max = 0;
430 if (vfs_getopt_size(opts, "maxfilesize", &maxfilesize) != 0)
431 maxfilesize = 0;
432 if (vfs_getopt_size(opts, "easize", &ea_max_size) != 0)
433 ea_max_size = 0;
434 nonc = vfs_getopt(opts, "nonc", NULL, NULL) == 0;
435 nomtime = vfs_getopt(opts, "nomtime", NULL, NULL) == 0;
436 pgread = vfs_getopt(opts, "pgread", NULL, NULL) == 0;
437
438 /* Do not allow mounts if we do not have enough memory to preserve
439 * the minimum reserved pages. */
440 if (tmpfs_mem_avail() < TMPFS_PAGES_MINRESERVED)
441 return (ENOSPC);
442
443 /* Get the maximum number of memory pages this file system is
444 * allowed to use, based on the maximum size the user passed in
445 * the mount structure. A value of zero is treated as if the
446 * maximum available space was requested. */
447 if (size_max == 0 || size_max > OFF_MAX - PAGE_SIZE ||
448 (SIZE_MAX < OFF_MAX && size_max / PAGE_SIZE >= SIZE_MAX))
449 pages = SIZE_MAX;
450 else {
451 size_max = roundup(size_max, PAGE_SIZE);
452 pages = howmany(size_max, PAGE_SIZE);
453 }
454 MPASS(pages > 0);
455
456 if (nodes_max <= 3) {
457 if (pages < INT_MAX / nodes_per_page)
458 nodes_max = pages * nodes_per_page;
459 else
460 nodes_max = INT_MAX;
461 }
462 if (nodes_max > INT_MAX)
463 nodes_max = INT_MAX;
464 MPASS(nodes_max >= 3);
465
466 /* Allocate the tmpfs mount structure and fill it. */
467 tmp = (struct tmpfs_mount *)malloc(sizeof(struct tmpfs_mount),
468 M_TMPFSMNT, M_WAITOK | M_ZERO);
469
470 mtx_init(&tmp->tm_allnode_lock, "tmpfs allnode lock", NULL, MTX_DEF);
471 tmp->tm_nodes_max = nodes_max;
472 tmp->tm_nodes_inuse = 0;
473 tmp->tm_ea_memory_inuse = 0;
474 tmp->tm_refcount = 1;
475 tmp->tm_maxfilesize = maxfilesize > 0 ? maxfilesize : OFF_MAX;
476 tmp->tm_ea_memory_max = ea_max_size > 0 ?
477 ea_max_size : TMPFS_EA_MEMORY_RESERVED;
478 LIST_INIT(&tmp->tm_nodes_used);
479
480 tmp->tm_size_max = size_max;
481 tmp->tm_pages_max = pages;
482 tmp->tm_pages_used = 0;
483 new_unrhdr64(&tmp->tm_ino_unr, 2);
484 tmp->tm_ronly = (mp->mnt_flag & MNT_RDONLY) != 0;
485 tmp->tm_nonc = nonc;
486 tmp->tm_nomtime = nomtime;
487 tmp->tm_pgread = pgread;
488
489 /* Allocate the root node. */
490 error = tmpfs_alloc_node(mp, tmp, VDIR, root_uid, root_gid,
491 root_mode & ALLPERMS, NULL, NULL, VNOVAL, &root);
492
493 if (error != 0 || root == NULL) {
494 free(tmp, M_TMPFSMNT);
495 return (error);
496 }
497 KASSERT(root->tn_id == 2,
498 ("tmpfs root with invalid ino: %ju", (uintmax_t)root->tn_id));
499 tmp->tm_root = root;
500
501 MNT_ILOCK(mp);
502 mp->mnt_flag |= MNT_LOCAL;
503 mp->mnt_kern_flag |= MNTK_LOOKUP_SHARED | MNTK_EXTENDED_SHARED |
504 MNTK_NOMSYNC;
505 if (!nonc && (mp->mnt_flag & MNT_UNION) == 0)
506 mp->mnt_kern_flag |= MNTK_FPLOOKUP;
507 MNT_IUNLOCK(mp);
508
509 mp->mnt_data = tmp;
510 mp->mnt_stat.f_namemax = MAXNAMLEN;
511 vfs_getnewfsid(mp);
512 vfs_mountedfrom(mp, "tmpfs");
513
514 return (0);
515 }
516
517 /* ARGSUSED2 */
518 static int
tmpfs_unmount(struct mount * mp,int mntflags)519 tmpfs_unmount(struct mount *mp, int mntflags)
520 {
521 struct tmpfs_mount *tmp;
522 struct tmpfs_node *node;
523 int error, flags;
524
525 flags = (mntflags & MNT_FORCE) != 0 ? FORCECLOSE : 0;
526 tmp = VFS_TO_TMPFS(mp);
527
528 /* Stop writers */
529 error = vfs_write_suspend_umnt(mp);
530 if (error != 0)
531 return (error);
532 /*
533 * At this point, nodes cannot be destroyed by any other
534 * thread because write suspension is started.
535 */
536
537 for (;;) {
538 error = vflush(mp, 0, flags, curthread);
539 if (error != 0) {
540 vfs_write_resume(mp, VR_START_WRITE);
541 return (error);
542 }
543 MNT_ILOCK(mp);
544 if (mp->mnt_nvnodelistsize == 0) {
545 MNT_IUNLOCK(mp);
546 break;
547 }
548 MNT_IUNLOCK(mp);
549 if ((mntflags & MNT_FORCE) == 0) {
550 vfs_write_resume(mp, VR_START_WRITE);
551 return (EBUSY);
552 }
553 }
554
555 TMPFS_LOCK(tmp);
556 while ((node = LIST_FIRST(&tmp->tm_nodes_used)) != NULL) {
557 TMPFS_NODE_LOCK(node);
558 if (node->tn_type == VDIR)
559 tmpfs_dir_destroy(tmp, node);
560 if (tmpfs_free_node_locked(tmp, node, true))
561 TMPFS_LOCK(tmp);
562 else
563 TMPFS_NODE_UNLOCK(node);
564 }
565
566 mp->mnt_data = NULL;
567 tmpfs_free_tmp(tmp);
568 vfs_write_resume(mp, VR_START_WRITE);
569
570 return (0);
571 }
572
573 void
tmpfs_free_tmp(struct tmpfs_mount * tmp)574 tmpfs_free_tmp(struct tmpfs_mount *tmp)
575 {
576 TMPFS_MP_ASSERT_LOCKED(tmp);
577 MPASS(tmp->tm_refcount > 0);
578
579 tmp->tm_refcount--;
580 if (tmp->tm_refcount > 0) {
581 TMPFS_UNLOCK(tmp);
582 return;
583 }
584 TMPFS_UNLOCK(tmp);
585
586 mtx_destroy(&tmp->tm_allnode_lock);
587 /*
588 * We cannot assert that tmp->tm_pages_used == 0 there,
589 * because tmpfs vm_objects might be still mapped by some
590 * process and outlive the mount due to reference counting.
591 */
592 MPASS(tmp->tm_nodes_inuse == 0);
593
594 free(tmp, M_TMPFSMNT);
595 }
596
597 static int
tmpfs_root(struct mount * mp,int flags,struct vnode ** vpp)598 tmpfs_root(struct mount *mp, int flags, struct vnode **vpp)
599 {
600 int error;
601
602 error = tmpfs_alloc_vp(mp, VFS_TO_TMPFS(mp)->tm_root, flags, vpp);
603 if (error == 0)
604 (*vpp)->v_vflag |= VV_ROOT;
605 return (error);
606 }
607
608 static int
tmpfs_fhtovp(struct mount * mp,struct fid * fhp,int flags,struct vnode ** vpp)609 tmpfs_fhtovp(struct mount *mp, struct fid *fhp, int flags,
610 struct vnode **vpp)
611 {
612 struct tmpfs_fid_data *tfd;
613 struct tmpfs_mount *tmp;
614 struct tmpfs_node *node;
615 int error;
616
617 if (fhp->fid_len != sizeof(*tfd))
618 return (EINVAL);
619
620 tfd = (struct tmpfs_fid_data *)fhp;
621
622 tmp = VFS_TO_TMPFS(mp);
623
624 if (tfd->tfd_id >= tmp->tm_nodes_max)
625 return (EINVAL);
626
627 TMPFS_LOCK(tmp);
628 LIST_FOREACH(node, &tmp->tm_nodes_used, tn_entries) {
629 if (node->tn_id == tfd->tfd_id &&
630 node->tn_gen == tfd->tfd_gen) {
631 tmpfs_ref_node(node);
632 break;
633 }
634 }
635 TMPFS_UNLOCK(tmp);
636
637 if (node != NULL) {
638 error = tmpfs_alloc_vp(mp, node, LK_EXCLUSIVE, vpp);
639 tmpfs_free_node(tmp, node);
640 } else
641 error = EINVAL;
642 return (error);
643 }
644
645 /* ARGSUSED2 */
646 static int
tmpfs_statfs(struct mount * mp,struct statfs * sbp)647 tmpfs_statfs(struct mount *mp, struct statfs *sbp)
648 {
649 struct tmpfs_mount *tmp;
650 size_t used;
651
652 tmp = VFS_TO_TMPFS(mp);
653
654 sbp->f_iosize = PAGE_SIZE;
655 sbp->f_bsize = PAGE_SIZE;
656
657 used = tmpfs_pages_used(tmp);
658 if (tmp->tm_pages_max != ULONG_MAX)
659 sbp->f_blocks = tmp->tm_pages_max;
660 else
661 sbp->f_blocks = used + tmpfs_mem_avail();
662 if (sbp->f_blocks <= used)
663 sbp->f_bavail = 0;
664 else
665 sbp->f_bavail = sbp->f_blocks - used;
666 sbp->f_bfree = sbp->f_bavail;
667 used = tmp->tm_nodes_inuse;
668 sbp->f_files = tmp->tm_nodes_max;
669 if (sbp->f_files <= used)
670 sbp->f_ffree = 0;
671 else
672 sbp->f_ffree = sbp->f_files - used;
673 /* sbp->f_owner = tmp->tn_uid; */
674
675 return (0);
676 }
677
678 static int
tmpfs_sync(struct mount * mp,int waitfor)679 tmpfs_sync(struct mount *mp, int waitfor)
680 {
681
682 if (waitfor == MNT_SUSPEND) {
683 MNT_ILOCK(mp);
684 mp->mnt_kern_flag |= MNTK_SUSPEND2 | MNTK_SUSPENDED;
685 MNT_IUNLOCK(mp);
686 } else if (waitfor == MNT_LAZY) {
687 tmpfs_update_mtime_lazy(mp);
688 }
689 return (0);
690 }
691
692 static int
tmpfs_init(struct vfsconf * conf)693 tmpfs_init(struct vfsconf *conf)
694 {
695 int res;
696
697 res = tmpfs_subr_init();
698 if (res != 0)
699 return (res);
700 memcpy(&tmpfs_fnops, &vnops, sizeof(struct fileops));
701 tmpfs_fnops.fo_close = tmpfs_fo_close;
702 return (0);
703 }
704
705 static int
tmpfs_uninit(struct vfsconf * conf)706 tmpfs_uninit(struct vfsconf *conf)
707 {
708 tmpfs_subr_uninit();
709 return (0);
710 }
711
712 /*
713 * tmpfs vfs operations.
714 */
715 struct vfsops tmpfs_vfsops = {
716 .vfs_mount = tmpfs_mount,
717 .vfs_unmount = tmpfs_unmount,
718 .vfs_root = vfs_cache_root,
719 .vfs_cachedroot = tmpfs_root,
720 .vfs_statfs = tmpfs_statfs,
721 .vfs_fhtovp = tmpfs_fhtovp,
722 .vfs_sync = tmpfs_sync,
723 .vfs_init = tmpfs_init,
724 .vfs_uninit = tmpfs_uninit,
725 };
726 VFS_SET(tmpfs_vfsops, tmpfs, VFCF_JAIL);
727
728 #ifdef DDB
729 #include <ddb/ddb.h>
730
731 static void
db_print_tmpfs(struct mount * mp,struct tmpfs_mount * tmp)732 db_print_tmpfs(struct mount *mp, struct tmpfs_mount *tmp)
733 {
734 db_printf("mp %p (%s) tmp %p\n", mp,
735 mp->mnt_stat.f_mntonname, tmp);
736 db_printf(
737 "\tsize max %ju pages max %lu pages used %lu\n"
738 "\tinodes max %ju inodes inuse %ju ea inuse %ju refcount %ju\n"
739 "\tmaxfilesize %ju r%c %snamecache %smtime\n",
740 (uintmax_t)tmp->tm_size_max, tmp->tm_pages_max, tmp->tm_pages_used,
741 (uintmax_t)tmp->tm_nodes_max, (uintmax_t)tmp->tm_nodes_inuse,
742 (uintmax_t)tmp->tm_ea_memory_inuse, (uintmax_t)tmp->tm_refcount,
743 (uintmax_t)tmp->tm_maxfilesize,
744 tmp->tm_ronly ? 'o' : 'w', tmp->tm_nonc ? "no" : "",
745 tmp->tm_nomtime ? "no" : "");
746 }
747
DB_SHOW_COMMAND(tmpfs,db_show_tmpfs)748 DB_SHOW_COMMAND(tmpfs, db_show_tmpfs)
749 {
750 struct mount *mp;
751 struct tmpfs_mount *tmp;
752
753 if (have_addr) {
754 mp = (struct mount *)addr;
755 tmp = VFS_TO_TMPFS(mp);
756 db_print_tmpfs(mp, tmp);
757 return;
758 }
759
760 TAILQ_FOREACH(mp, &mountlist, mnt_list) {
761 if (strcmp(mp->mnt_stat.f_fstypename, tmpfs_vfsconf.vfc_name) ==
762 0) {
763 tmp = VFS_TO_TMPFS(mp);
764 db_print_tmpfs(mp, tmp);
765 }
766 }
767 }
768 #endif /* DDB */
769