1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21 /*
22 * Copyright (c) 1990, 2010, Oracle and/or its affiliates. All rights reserved.
23 * Copyright 2015 Joyent, Inc.
24 */
25
26 #include <sys/types.h>
27 #include <sys/param.h>
28 #include <sys/sysmacros.h>
29 #include <sys/kmem.h>
30 #include <sys/time.h>
31 #include <sys/pathname.h>
32 #include <sys/vfs.h>
33 #include <sys/vfs_opreg.h>
34 #include <sys/vnode.h>
35 #include <sys/stat.h>
36 #include <sys/uio.h>
37 #include <sys/stat.h>
38 #include <sys/errno.h>
39 #include <sys/cmn_err.h>
40 #include <sys/cred.h>
41 #include <sys/statvfs.h>
42 #include <sys/mount.h>
43 #include <sys/debug.h>
44 #include <sys/systm.h>
45 #include <sys/mntent.h>
46 #include <fs/fs_subr.h>
47 #include <vm/page.h>
48 #include <vm/anon.h>
49 #include <sys/model.h>
50 #include <sys/policy.h>
51
52 #include <sys/fs/swapnode.h>
53 #include <sys/fs/tmp.h>
54 #include <sys/fs/tmpnode.h>
55
56 static int tmpfsfstype;
57
58 /*
59 * tmpfs vfs operations.
60 */
61 static int tmpfsinit(int, char *);
62 static int tmp_mount(struct vfs *, struct vnode *,
63 struct mounta *, struct cred *);
64 static int tmp_unmount(struct vfs *, int, struct cred *);
65 static int tmp_root(struct vfs *, struct vnode **);
66 static int tmp_statvfs(struct vfs *, struct statvfs64 *);
67 static int tmp_vget(struct vfs *, struct vnode **, struct fid *);
68
69 /*
70 * Loadable module wrapper
71 */
72 #include <sys/modctl.h>
73
74 static mntopts_t tmpfs_proto_opttbl;
75
76 static vfsdef_t vfw = {
77 VFSDEF_VERSION,
78 "tmpfs",
79 tmpfsinit,
80 VSW_HASPROTO|VSW_CANREMOUNT|VSW_STATS|VSW_ZMOUNT,
81 &tmpfs_proto_opttbl
82 };
83
84 /*
85 * in-kernel mnttab options
86 */
87 static char *xattr_cancel[] = { MNTOPT_NOXATTR, NULL };
88 static char *noxattr_cancel[] = { MNTOPT_XATTR, NULL };
89
90 static mntopt_t tmpfs_options[] = {
91 /* Option name Cancel Opt Arg Flags Data */
92 { MNTOPT_XATTR, xattr_cancel, NULL, MO_DEFAULT, NULL},
93 { MNTOPT_NOXATTR, noxattr_cancel, NULL, NULL, NULL},
94 { "size", NULL, "0", MO_HASVALUE, NULL},
95 { "mode", NULL, NULL, MO_HASVALUE, NULL}
96 };
97
98
99 static mntopts_t tmpfs_proto_opttbl = {
100 sizeof (tmpfs_options) / sizeof (mntopt_t),
101 tmpfs_options
102 };
103
104 /*
105 * Module linkage information
106 */
107 static struct modlfs modlfs = {
108 &mod_fsops, "filesystem for tmpfs", &vfw
109 };
110
111 static struct modlinkage modlinkage = {
112 MODREV_1, &modlfs, NULL
113 };
114
115 int
116 _init()
117 {
118 return (mod_install(&modlinkage));
119 }
120
121 int
122 _fini()
123 {
124 int error;
125
126 error = mod_remove(&modlinkage);
127 if (error)
128 return (error);
129 /*
130 * Tear down the operations vectors
131 */
132 (void) vfs_freevfsops_by_type(tmpfsfstype);
133 vn_freevnodeops(tmp_vnodeops);
134 return (0);
135 }
136
137 int
138 _info(struct modinfo *modinfop)
139 {
140 return (mod_info(&modlinkage, modinfop));
141 }
142
143 /*
144 * The following are patchable variables limiting the amount of system
145 * resources tmpfs can use.
146 *
147 * tmpfs_maxkmem limits the amount of kernel kmem_alloc memory
148 * tmpfs can use for it's data structures (e.g. tmpnodes, directory entries)
149 * It is not determined by setting a hard limit but rather as a percentage of
150 * physical memory which is determined when tmpfs is first used in the system.
151 *
152 * tmpfs_minfree is the minimum amount of swap space that tmpfs leaves for
153 * the rest of the system. In other words, if the amount of free swap space
154 * in the system (i.e. anoninfo.ani_free) drops below tmpfs_minfree, tmpfs
155 * anon allocations will fail.
156 *
157 * There is also a per mount limit on the amount of swap space
158 * (tmount.tm_anonmax) settable via a mount option.
159 */
160 size_t tmpfs_maxkmem = 0;
161 size_t tmpfs_minfree = 0;
162 size_t tmp_kmemspace; /* bytes of kernel heap used by all tmpfs */
163
164 static major_t tmpfs_major;
165 static minor_t tmpfs_minor;
166 static kmutex_t tmpfs_minor_lock;
167
168 /*
169 * initialize global tmpfs locks and such
170 * called when loading tmpfs module
171 */
172 static int
173 tmpfsinit(int fstype, char *name)
174 {
175 static const fs_operation_def_t tmp_vfsops_template[] = {
176 VFSNAME_MOUNT, { .vfs_mount = tmp_mount },
177 VFSNAME_UNMOUNT, { .vfs_unmount = tmp_unmount },
178 VFSNAME_ROOT, { .vfs_root = tmp_root },
179 VFSNAME_STATVFS, { .vfs_statvfs = tmp_statvfs },
180 VFSNAME_VGET, { .vfs_vget = tmp_vget },
181 NULL, NULL
182 };
183 int error;
184 extern void tmpfs_hash_init();
185
186 tmpfs_hash_init();
187 tmpfsfstype = fstype;
188 ASSERT(tmpfsfstype != 0);
189
190 error = vfs_setfsops(fstype, tmp_vfsops_template, NULL);
191 if (error != 0) {
192 cmn_err(CE_WARN, "tmpfsinit: bad vfs ops template");
193 return (error);
194 }
195
196 error = vn_make_ops(name, tmp_vnodeops_template, &tmp_vnodeops);
197 if (error != 0) {
198 (void) vfs_freevfsops_by_type(fstype);
199 cmn_err(CE_WARN, "tmpfsinit: bad vnode ops template");
200 return (error);
201 }
202
203 /*
204 * tmpfs_minfree doesn't need to be some function of configured
205 * swap space since it really is an absolute limit of swap space
206 * which still allows other processes to execute.
207 */
208 if (tmpfs_minfree == 0) {
209 /*
210 * Set if not patched
211 */
212 tmpfs_minfree = btopr(TMPMINFREE);
213 }
214
215 /*
216 * The maximum amount of space tmpfs can allocate is
217 * TMPMAXPROCKMEM percent of kernel memory
218 */
219 if (tmpfs_maxkmem == 0)
220 tmpfs_maxkmem = MAX(PAGESIZE, kmem_maxavail() / TMPMAXFRACKMEM);
221
222 if ((tmpfs_major = getudev()) == (major_t)-1) {
223 cmn_err(CE_WARN, "tmpfsinit: Can't get unique device number.");
224 tmpfs_major = 0;
225 }
226 mutex_init(&tmpfs_minor_lock, NULL, MUTEX_DEFAULT, NULL);
227 return (0);
228 }
229
230 static int
231 tmp_mount(vfs_t *vfsp, vnode_t *mvp, struct mounta *uap, cred_t *cr)
232 {
233 struct tmount *tm = NULL;
234 struct tmpnode *tp;
235 struct pathname dpn;
236 int error;
237 pgcnt_t anonmax;
238 struct vattr rattr;
239 int got_attrs;
240 boolean_t mode_arg = B_FALSE;
241 mode_t root_mode = 0777;
242 char *argstr;
243
244 if ((error = secpolicy_fs_mount(cr, mvp, vfsp)) != 0)
245 return (error);
246
247 if (mvp->v_type != VDIR)
248 return (ENOTDIR);
249
250 mutex_enter(&mvp->v_lock);
251 if ((uap->flags & MS_REMOUNT) == 0 && (uap->flags & MS_OVERLAY) == 0 &&
252 (mvp->v_count != 1 || (mvp->v_flag & VROOT))) {
253 mutex_exit(&mvp->v_lock);
254 return (EBUSY);
255 }
256 mutex_exit(&mvp->v_lock);
257
258 /*
259 * Having the resource be anything but "swap" doesn't make sense.
260 */
261 vfs_setresource(vfsp, "swap", 0);
262
263 /*
264 * now look for options we understand...
265 */
266
267 /* tmpfs doesn't support read-only mounts */
268 if (vfs_optionisset(vfsp, MNTOPT_RO, NULL)) {
269 error = EINVAL;
270 goto out;
271 }
272
273 /*
274 * tm_anonmax is set according to the mount arguments
275 * if any. Otherwise, it is set to a maximum value.
276 */
277 if (vfs_optionisset(vfsp, "size", &argstr)) {
278 if ((error = tmp_convnum(argstr, &anonmax)) != 0)
279 goto out;
280 } else {
281 anonmax = ULONG_MAX;
282 }
283
284 /*
285 * The "mode" mount argument allows the operator to override the
286 * permissions of the root of the tmpfs mount.
287 */
288 if (vfs_optionisset(vfsp, "mode", &argstr)) {
289 if ((error = tmp_convmode(argstr, &root_mode)) != 0) {
290 goto out;
291 }
292 mode_arg = B_TRUE;
293 }
294
295 if (error = pn_get(uap->dir,
296 (uap->flags & MS_SYSSPACE) ? UIO_SYSSPACE : UIO_USERSPACE, &dpn))
297 goto out;
298
299 if (uap->flags & MS_REMOUNT) {
300 tm = (struct tmount *)VFSTOTM(vfsp);
301
302 /*
303 * If we change the size so its less than what is currently
304 * being used, we allow that. The file system will simply be
305 * full until enough files have been removed to get below the
306 * new max.
307 */
308 mutex_enter(&tm->tm_contents);
309 tm->tm_anonmax = anonmax;
310 mutex_exit(&tm->tm_contents);
311 goto out;
312 }
313
314 if ((tm = tmp_memalloc(sizeof (struct tmount), 0)) == NULL) {
315 pn_free(&dpn);
316 error = ENOMEM;
317 goto out;
318 }
319
320 /*
321 * find an available minor device number for this mount
322 */
323 mutex_enter(&tmpfs_minor_lock);
324 do {
325 tmpfs_minor = (tmpfs_minor + 1) & L_MAXMIN32;
326 tm->tm_dev = makedevice(tmpfs_major, tmpfs_minor);
327 } while (vfs_devismounted(tm->tm_dev));
328 mutex_exit(&tmpfs_minor_lock);
329
330 /*
331 * Set but don't bother entering the mutex
332 * (tmount not on mount list yet)
333 */
334 mutex_init(&tm->tm_contents, NULL, MUTEX_DEFAULT, NULL);
335 mutex_init(&tm->tm_renamelck, NULL, MUTEX_DEFAULT, NULL);
336
337 tm->tm_vfsp = vfsp;
338 tm->tm_anonmax = anonmax;
339
340 vfsp->vfs_data = (caddr_t)tm;
341 vfsp->vfs_fstype = tmpfsfstype;
342 vfsp->vfs_dev = tm->tm_dev;
343 vfsp->vfs_bsize = PAGESIZE;
344 vfsp->vfs_flag |= VFS_NOTRUNC;
345 vfs_make_fsid(&vfsp->vfs_fsid, tm->tm_dev, tmpfsfstype);
346 tm->tm_mntpath = tmp_memalloc(dpn.pn_pathlen + 1, TMP_MUSTHAVE);
347 (void) strcpy(tm->tm_mntpath, dpn.pn_path);
348
349 /*
350 * allocate and initialize root tmpnode structure
351 */
352 bzero(&rattr, sizeof (struct vattr));
353 rattr.va_mode = (mode_t)(S_IFDIR | root_mode);
354 rattr.va_type = VDIR;
355 rattr.va_rdev = 0;
356 tp = tmp_memalloc(sizeof (struct tmpnode), TMP_MUSTHAVE);
357 tmpnode_init(tm, tp, &rattr, cr);
358
359 /*
360 * Get the mode, uid, and gid from the underlying mount point.
361 */
362 rattr.va_mask = AT_MODE|AT_UID|AT_GID; /* Hint to getattr */
363 got_attrs = VOP_GETATTR(mvp, &rattr, 0, cr, NULL);
364
365 rw_enter(&tp->tn_rwlock, RW_WRITER);
366 TNTOV(tp)->v_flag |= VROOT;
367
368 /*
369 * If the getattr succeeded, use its results. Otherwise allow
370 * the previously set hardwired defaults to prevail.
371 */
372 if (got_attrs == 0) {
373 if (!mode_arg) {
374 /*
375 * Only use the underlying mount point for the
376 * mode if the "mode" mount argument was not
377 * provided.
378 */
379 tp->tn_mode = rattr.va_mode;
380 }
381 tp->tn_uid = rattr.va_uid;
382 tp->tn_gid = rattr.va_gid;
383 }
384
385 /*
386 * initialize linked list of tmpnodes so that the back pointer of
387 * the root tmpnode always points to the last one on the list
388 * and the forward pointer of the last node is null
389 */
390 tp->tn_back = tp;
391 tp->tn_forw = NULL;
392 tp->tn_nlink = 0;
393 tm->tm_rootnode = tp;
394
395 tdirinit(tp, tp);
396
397 rw_exit(&tp->tn_rwlock);
398
399 pn_free(&dpn);
400 error = 0;
401
402 out:
403 if (error == 0)
404 vfs_set_feature(vfsp, VFSFT_SYSATTR_VIEWS);
405
406 return (error);
407 }
408
409 static int
410 tmp_unmount(struct vfs *vfsp, int flag, struct cred *cr)
411 {
412 struct tmount *tm = (struct tmount *)VFSTOTM(vfsp);
413 struct tmpnode *tnp, *cancel;
414 struct vnode *vp;
415 int error;
416
417 if ((error = secpolicy_fs_unmount(cr, vfsp)) != 0)
418 return (error);
419
420 /*
421 * forced unmount is not supported by this file system
422 * and thus, ENOTSUP, is being returned.
423 */
424 if (flag & MS_FORCE)
425 return (ENOTSUP);
426
427 mutex_enter(&tm->tm_contents);
428
429 /*
430 * If there are no open files, only the root node should have
431 * a reference count.
432 * With tm_contents held, nothing can be added or removed.
433 * There may be some dirty pages. To prevent fsflush from
434 * disrupting the unmount, put a hold on each node while scanning.
435 * If we find a previously referenced node, undo the holds we have
436 * placed and fail EBUSY.
437 */
438 tnp = tm->tm_rootnode;
439 if (TNTOV(tnp)->v_count > 1) {
440 mutex_exit(&tm->tm_contents);
441 return (EBUSY);
442 }
443
444 for (tnp = tnp->tn_forw; tnp; tnp = tnp->tn_forw) {
445 if ((vp = TNTOV(tnp))->v_count > 0) {
446 cancel = tm->tm_rootnode->tn_forw;
447 while (cancel != tnp) {
448 vp = TNTOV(cancel);
449 ASSERT(vp->v_count > 0);
450 VN_RELE(vp);
451 cancel = cancel->tn_forw;
452 }
453 mutex_exit(&tm->tm_contents);
454 return (EBUSY);
455 }
456 VN_HOLD(vp);
457 }
458
459 /*
460 * We can drop the mutex now because no one can find this mount
461 */
462 mutex_exit(&tm->tm_contents);
463
464 /*
465 * Free all kmemalloc'd and anonalloc'd memory associated with
466 * this filesystem. To do this, we go through the file list twice,
467 * once to remove all the directory entries, and then to remove
468 * all the files. We do this because there is useful code in
469 * tmpnode_free which assumes that the directory entry has been
470 * removed before the file.
471 */
472 /*
473 * Remove all directory entries
474 */
475 for (tnp = tm->tm_rootnode; tnp; tnp = tnp->tn_forw) {
476 rw_enter(&tnp->tn_rwlock, RW_WRITER);
477 if (tnp->tn_type == VDIR)
478 tdirtrunc(tnp);
479 if (tnp->tn_vnode->v_flag & V_XATTRDIR) {
480 /*
481 * Account for implicit attrdir reference.
482 */
483 ASSERT(tnp->tn_nlink > 0);
484 DECR_COUNT(&tnp->tn_nlink, &tnp->tn_tlock);
485 }
486 rw_exit(&tnp->tn_rwlock);
487 }
488
489 ASSERT(tm->tm_rootnode);
490
491 /*
492 * All links are gone, v_count is keeping nodes in place.
493 * VN_RELE should make the node disappear, unless somebody
494 * is holding pages against it. Nap and retry until it disappears.
495 *
496 * We re-acquire the lock to prevent others who have a HOLD on
497 * a tmpnode via its pages or anon slots from blowing it away
498 * (in tmp_inactive) while we're trying to get to it here. Once
499 * we have a HOLD on it we know it'll stick around.
500 *
501 */
502 mutex_enter(&tm->tm_contents);
503 /*
504 * Remove all the files (except the rootnode) backwards.
505 */
506 while ((tnp = tm->tm_rootnode->tn_back) != tm->tm_rootnode) {
507 mutex_exit(&tm->tm_contents);
508 /*
509 * Inhibit tmp_inactive from touching attribute directory
510 * as all nodes will be released here.
511 * Note we handled the link count in pass 2 above.
512 */
513 rw_enter(&tnp->tn_rwlock, RW_WRITER);
514 tnp->tn_xattrdp = NULL;
515 rw_exit(&tnp->tn_rwlock);
516 vp = TNTOV(tnp);
517 VN_RELE(vp);
518 mutex_enter(&tm->tm_contents);
519 /*
520 * It's still there after the RELE. Someone else like pageout
521 * has a hold on it so wait a bit and then try again - we know
522 * they'll give it up soon.
523 */
524 if (tnp == tm->tm_rootnode->tn_back) {
525 VN_HOLD(vp);
526 mutex_exit(&tm->tm_contents);
527 delay(hz / 4);
528 mutex_enter(&tm->tm_contents);
529 }
530 }
531 mutex_exit(&tm->tm_contents);
532
533 tm->tm_rootnode->tn_xattrdp = NULL;
534 VN_RELE(TNTOV(tm->tm_rootnode));
535
536 ASSERT(tm->tm_mntpath);
537
538 tmp_memfree(tm->tm_mntpath, strlen(tm->tm_mntpath) + 1);
539
540 ASSERT(tm->tm_anonmem == 0);
541
542 mutex_destroy(&tm->tm_contents);
543 mutex_destroy(&tm->tm_renamelck);
544 tmp_memfree(tm, sizeof (struct tmount));
545
546 return (0);
547 }
548
549 /*
550 * return root tmpnode for given vnode
551 */
552 static int
553 tmp_root(struct vfs *vfsp, struct vnode **vpp)
554 {
555 struct tmount *tm = (struct tmount *)VFSTOTM(vfsp);
556 struct tmpnode *tp = tm->tm_rootnode;
557 struct vnode *vp;
558
559 ASSERT(tp);
560
561 vp = TNTOV(tp);
562 VN_HOLD(vp);
563 *vpp = vp;
564 return (0);
565 }
566
567 static int
568 tmp_statvfs(struct vfs *vfsp, struct statvfs64 *sbp)
569 {
570 struct tmount *tm = (struct tmount *)VFSTOTM(vfsp);
571 ulong_t blocks;
572 dev32_t d32;
573 zoneid_t eff_zid;
574 struct zone *zp;
575
576 /*
577 * The file system may have been mounted by the global zone on
578 * behalf of the non-global zone. In that case, the tmount zone_id
579 * will be the global zone. We still want to show the swap cap inside
580 * the zone in this case, even though the file system was mounted by
581 * the global zone.
582 */
583 if (curproc->p_zone->zone_id != GLOBAL_ZONEUNIQID)
584 zp = curproc->p_zone;
585 else
586 zp = tm->tm_vfsp->vfs_zone;
587
588 if (zp == NULL)
589 eff_zid = GLOBAL_ZONEUNIQID;
590 else
591 eff_zid = zp->zone_id;
592
593 sbp->f_bsize = PAGESIZE;
594 sbp->f_frsize = PAGESIZE;
595
596 /*
597 * Find the amount of available physical and memory swap
598 */
599 mutex_enter(&anoninfo_lock);
600 ASSERT(k_anoninfo.ani_max >= k_anoninfo.ani_phys_resv);
601 blocks = (ulong_t)CURRENT_TOTAL_AVAILABLE_SWAP;
602 mutex_exit(&anoninfo_lock);
603
604 /*
605 * If tm_anonmax for this mount is less than the available swap space
606 * (minus the amount tmpfs can't use), use that instead
607 */
608 if (blocks > tmpfs_minfree)
609 sbp->f_bfree = MIN(blocks - tmpfs_minfree,
610 tm->tm_anonmax - tm->tm_anonmem);
611 else
612 sbp->f_bfree = 0;
613
614 sbp->f_bavail = sbp->f_bfree;
615
616 /*
617 * Total number of blocks is what's available plus what's been used
618 */
619 sbp->f_blocks = (fsblkcnt64_t)(sbp->f_bfree + tm->tm_anonmem);
620
621 if (eff_zid != GLOBAL_ZONEUNIQID &&
622 zp->zone_max_swap_ctl != UINT64_MAX) {
623 /*
624 * If the fs is used by a non-global zone with a swap cap,
625 * then report the capped size.
626 */
627 rctl_qty_t cap, used;
628 pgcnt_t pgcap, pgused;
629
630 mutex_enter(&zp->zone_mem_lock);
631 cap = zp->zone_max_swap_ctl;
632 used = zp->zone_max_swap;
633 mutex_exit(&zp->zone_mem_lock);
634
635 pgcap = btop(cap);
636 pgused = btop(used);
637
638 sbp->f_bfree = MIN(pgcap - pgused, sbp->f_bfree);
639 sbp->f_bavail = sbp->f_bfree;
640 sbp->f_blocks = MIN(pgcap, sbp->f_blocks);
641 }
642
643 /*
644 * The maximum number of files available is approximately the number
645 * of tmpnodes we can allocate from the remaining kernel memory
646 * available to tmpfs. This is fairly inaccurate since it doesn't
647 * take into account the names stored in the directory entries.
648 */
649 if (tmpfs_maxkmem > tmp_kmemspace)
650 sbp->f_ffree = (tmpfs_maxkmem - tmp_kmemspace) /
651 (sizeof (struct tmpnode) + sizeof (struct tdirent));
652 else
653 sbp->f_ffree = 0;
654
655 sbp->f_files = tmpfs_maxkmem /
656 (sizeof (struct tmpnode) + sizeof (struct tdirent));
657 sbp->f_favail = (fsfilcnt64_t)(sbp->f_ffree);
658 (void) cmpldev(&d32, vfsp->vfs_dev);
659 sbp->f_fsid = d32;
660 (void) strcpy(sbp->f_basetype, vfssw[tmpfsfstype].vsw_name);
661 (void) strncpy(sbp->f_fstr, tm->tm_mntpath, sizeof (sbp->f_fstr));
662 /*
663 * ensure null termination
664 */
665 sbp->f_fstr[sizeof (sbp->f_fstr) - 1] = '\0';
666 sbp->f_flag = vf_to_stf(vfsp->vfs_flag);
667 sbp->f_namemax = MAXNAMELEN - 1;
668 return (0);
669 }
670
671 static int
672 tmp_vget(struct vfs *vfsp, struct vnode **vpp, struct fid *fidp)
673 {
674 struct tfid *tfid;
675 struct tmount *tm = (struct tmount *)VFSTOTM(vfsp);
676 struct tmpnode *tp = NULL;
677
678 tfid = (struct tfid *)fidp;
679 *vpp = NULL;
680
681 mutex_enter(&tm->tm_contents);
682 for (tp = tm->tm_rootnode; tp; tp = tp->tn_forw) {
683 mutex_enter(&tp->tn_tlock);
684 if (tp->tn_nodeid == tfid->tfid_ino) {
685 /*
686 * If the gen numbers don't match we know the
687 * file won't be found since only one tmpnode
688 * can have this number at a time.
689 */
690 if (tp->tn_gen != tfid->tfid_gen || tp->tn_nlink == 0) {
691 mutex_exit(&tp->tn_tlock);
692 mutex_exit(&tm->tm_contents);
693 return (0);
694 }
695 *vpp = (struct vnode *)TNTOV(tp);
696
697 VN_HOLD(*vpp);
698
699 if ((tp->tn_mode & S_ISVTX) &&
700 !(tp->tn_mode & (S_IXUSR | S_IFDIR))) {
701 mutex_enter(&(*vpp)->v_lock);
702 (*vpp)->v_flag |= VISSWAP;
703 mutex_exit(&(*vpp)->v_lock);
704 }
705 mutex_exit(&tp->tn_tlock);
706 mutex_exit(&tm->tm_contents);
707 return (0);
708 }
709 mutex_exit(&tp->tn_tlock);
710 }
711 mutex_exit(&tm->tm_contents);
712 return (0);
713 }