1 /* $NetBSD: tmpfs_subr.c,v 1.35 2007/07/09 21:10:50 ad 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 supporting functions.
37 */
38 #include <sys/cdefs.h>
39 __FBSDID("$FreeBSD$");
40
41 #include <sys/param.h>
42 #include <sys/systm.h>
43 #include <sys/dirent.h>
44 #include <sys/fnv_hash.h>
45 #include <sys/lock.h>
46 #include <sys/limits.h>
47 #include <sys/mount.h>
48 #include <sys/namei.h>
49 #include <sys/priv.h>
50 #include <sys/proc.h>
51 #include <sys/random.h>
52 #include <sys/refcount.h>
53 #include <sys/rwlock.h>
54 #include <sys/smr.h>
55 #include <sys/stat.h>
56 #include <sys/sysctl.h>
57 #include <sys/vnode.h>
58 #include <sys/vmmeter.h>
59
60 #include <vm/vm.h>
61 #include <vm/vm_param.h>
62 #include <vm/vm_object.h>
63 #include <vm/vm_page.h>
64 #include <vm/vm_pageout.h>
65 #include <vm/vm_pager.h>
66 #include <vm/vm_extern.h>
67 #include <vm/swap_pager.h>
68
69 #include <fs/tmpfs/tmpfs.h>
70 #include <fs/tmpfs/tmpfs_fifoops.h>
71 #include <fs/tmpfs/tmpfs_vnops.h>
72
73 SYSCTL_NODE(_vfs, OID_AUTO, tmpfs, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
74 "tmpfs file system");
75
76 static long tmpfs_pages_reserved = TMPFS_PAGES_MINRESERVED;
77
78 MALLOC_DEFINE(M_TMPFSDIR, "tmpfs dir", "tmpfs dirent structure");
79 static uma_zone_t tmpfs_node_pool;
80 VFS_SMR_DECLARE;
81
82 static int
83 tmpfs_node_ctor(void *mem, int size, void *arg, int flags)
84 {
85 struct tmpfs_node *node;
86
87 node = mem;
88 node->tn_gen++;
89 node->tn_size = 0;
90 node->tn_status = 0;
91 node->tn_accessed = false;
92 node->tn_flags = 0;
93 node->tn_links = 0;
94 node->tn_vnode = NULL;
95 node->tn_vpstate = 0;
96 return (0);
97 }
98
99 static void
100 tmpfs_node_dtor(void *mem, int size, void *arg)
101 {
102 struct tmpfs_node *node;
103
104 node = mem;
105 node->tn_type = VNON;
106 }
107
108 static int
109 tmpfs_node_init(void *mem, int size, int flags)
110 {
111 struct tmpfs_node *node;
112
113 node = mem;
114 node->tn_id = 0;
115 mtx_init(&node->tn_interlock, "tmpfsni", NULL, MTX_DEF);
116 node->tn_gen = arc4random();
117 return (0);
118 }
119
120 static void
121 tmpfs_node_fini(void *mem, int size)
122 {
123 struct tmpfs_node *node;
124
125 node = mem;
126 mtx_destroy(&node->tn_interlock);
127 }
128
129 void
130 tmpfs_subr_init(void)
131 {
132 tmpfs_node_pool = uma_zcreate("TMPFS node",
133 sizeof(struct tmpfs_node), tmpfs_node_ctor, tmpfs_node_dtor,
134 tmpfs_node_init, tmpfs_node_fini, UMA_ALIGN_PTR, 0);
135 VFS_SMR_ZONE_SET(tmpfs_node_pool);
136 }
137
138 void
139 tmpfs_subr_uninit(void)
140 {
141 uma_zdestroy(tmpfs_node_pool);
142 }
143
144 static int
145 sysctl_mem_reserved(SYSCTL_HANDLER_ARGS)
146 {
147 int error;
148 long pages, bytes;
149
150 pages = *(long *)arg1;
151 bytes = pages * PAGE_SIZE;
152
153 error = sysctl_handle_long(oidp, &bytes, 0, req);
154 if (error || !req->newptr)
155 return (error);
156
157 pages = bytes / PAGE_SIZE;
158 if (pages < TMPFS_PAGES_MINRESERVED)
159 return (EINVAL);
160
161 *(long *)arg1 = pages;
162 return (0);
163 }
164
165 SYSCTL_PROC(_vfs_tmpfs, OID_AUTO, memory_reserved,
166 CTLTYPE_LONG|CTLFLAG_MPSAFE|CTLFLAG_RW, &tmpfs_pages_reserved, 0,
167 sysctl_mem_reserved, "L",
168 "Amount of available memory and swap below which tmpfs growth stops");
169
170 static __inline int tmpfs_dirtree_cmp(struct tmpfs_dirent *a,
171 struct tmpfs_dirent *b);
172 RB_PROTOTYPE_STATIC(tmpfs_dir, tmpfs_dirent, uh.td_entries, tmpfs_dirtree_cmp);
173
174 size_t
175 tmpfs_mem_avail(void)
176 {
177 size_t avail;
178 long reserved;
179
180 avail = swap_pager_avail + vm_free_count();
181 reserved = atomic_load_long(&tmpfs_pages_reserved);
182 if (__predict_false(avail < reserved))
183 return (0);
184 return (avail - reserved);
185 }
186
187 size_t
188 tmpfs_pages_used(struct tmpfs_mount *tmp)
189 {
190 const size_t node_size = sizeof(struct tmpfs_node) +
191 sizeof(struct tmpfs_dirent);
192 size_t meta_pages;
193
194 meta_pages = howmany((uintmax_t)tmp->tm_nodes_inuse * node_size,
195 PAGE_SIZE);
196 return (meta_pages + tmp->tm_pages_used);
197 }
198
199 static size_t
200 tmpfs_pages_check_avail(struct tmpfs_mount *tmp, size_t req_pages)
201 {
202 if (tmpfs_mem_avail() < req_pages)
203 return (0);
204
205 if (tmp->tm_pages_max != ULONG_MAX &&
206 tmp->tm_pages_max < req_pages + tmpfs_pages_used(tmp))
207 return (0);
208
209 return (1);
210 }
211
212 void
213 tmpfs_ref_node(struct tmpfs_node *node)
214 {
215 #ifdef INVARIANTS
216 u_int old;
217
218 old =
219 #endif
220 refcount_acquire(&node->tn_refcount);
221 #ifdef INVARIANTS
222 KASSERT(old > 0, ("node %p zero refcount", node));
223 #endif
224 }
225
226 /*
227 * Allocates a new node of type 'type' inside the 'tmp' mount point, with
228 * its owner set to 'uid', its group to 'gid' and its mode set to 'mode',
229 * using the credentials of the process 'p'.
230 *
231 * If the node type is set to 'VDIR', then the parent parameter must point
232 * to the parent directory of the node being created. It may only be NULL
233 * while allocating the root node.
234 *
235 * If the node type is set to 'VBLK' or 'VCHR', then the rdev parameter
236 * specifies the device the node represents.
237 *
238 * If the node type is set to 'VLNK', then the parameter target specifies
239 * the file name of the target file for the symbolic link that is being
240 * created.
241 *
242 * Note that new nodes are retrieved from the available list if it has
243 * items or, if it is empty, from the node pool as long as there is enough
244 * space to create them.
245 *
246 * Returns zero on success or an appropriate error code on failure.
247 */
248 int
249 tmpfs_alloc_node(struct mount *mp, struct tmpfs_mount *tmp, enum vtype type,
250 uid_t uid, gid_t gid, mode_t mode, struct tmpfs_node *parent,
251 const char *target, dev_t rdev, struct tmpfs_node **node)
252 {
253 struct tmpfs_node *nnode;
254 vm_object_t obj;
255 char *symlink;
256 char symlink_smr;
257
258 /* If the root directory of the 'tmp' file system is not yet
259 * allocated, this must be the request to do it. */
260 MPASS(IMPLIES(tmp->tm_root == NULL, parent == NULL && type == VDIR));
261
262 MPASS(IFF(type == VLNK, target != NULL));
263 MPASS(IFF(type == VBLK || type == VCHR, rdev != VNOVAL));
264
265 if (tmp->tm_nodes_inuse >= tmp->tm_nodes_max)
266 return (ENOSPC);
267 if (tmpfs_pages_check_avail(tmp, 1) == 0)
268 return (ENOSPC);
269
270 if ((mp->mnt_kern_flag & MNTK_UNMOUNT) != 0) {
271 /*
272 * When a new tmpfs node is created for fully
273 * constructed mount point, there must be a parent
274 * node, which vnode is locked exclusively. As
275 * consequence, if the unmount is executing in
276 * parallel, vflush() cannot reclaim the parent vnode.
277 * Due to this, the check for MNTK_UNMOUNT flag is not
278 * racy: if we did not see MNTK_UNMOUNT flag, then tmp
279 * cannot be destroyed until node construction is
280 * finished and the parent vnode unlocked.
281 *
282 * Tmpfs does not need to instantiate new nodes during
283 * unmount.
284 */
285 return (EBUSY);
286 }
287 if ((mp->mnt_kern_flag & MNT_RDONLY) != 0)
288 return (EROFS);
289
290 nnode = uma_zalloc_smr(tmpfs_node_pool, M_WAITOK);
291
292 /* Generic initialization. */
293 nnode->tn_type = type;
294 vfs_timestamp(&nnode->tn_atime);
295 nnode->tn_birthtime = nnode->tn_ctime = nnode->tn_mtime =
296 nnode->tn_atime;
297 nnode->tn_uid = uid;
298 nnode->tn_gid = gid;
299 nnode->tn_mode = mode;
300 nnode->tn_id = alloc_unr64(&tmp->tm_ino_unr);
301 nnode->tn_refcount = 1;
302
303 /* Type-specific initialization. */
304 switch (nnode->tn_type) {
305 case VBLK:
306 case VCHR:
307 nnode->tn_rdev = rdev;
308 break;
309
310 case VDIR:
311 RB_INIT(&nnode->tn_dir.tn_dirhead);
312 LIST_INIT(&nnode->tn_dir.tn_dupindex);
313 MPASS(parent != nnode);
314 MPASS(IMPLIES(parent == NULL, tmp->tm_root == NULL));
315 nnode->tn_dir.tn_parent = (parent == NULL) ? nnode : parent;
316 nnode->tn_dir.tn_readdir_lastn = 0;
317 nnode->tn_dir.tn_readdir_lastp = NULL;
318 nnode->tn_links++;
319 TMPFS_NODE_LOCK(nnode->tn_dir.tn_parent);
320 nnode->tn_dir.tn_parent->tn_links++;
321 TMPFS_NODE_UNLOCK(nnode->tn_dir.tn_parent);
322 break;
323
324 case VFIFO:
325 /* FALLTHROUGH */
326 case VSOCK:
327 break;
328
329 case VLNK:
330 MPASS(strlen(target) < MAXPATHLEN);
331 nnode->tn_size = strlen(target);
332
333 symlink = NULL;
334 if (!tmp->tm_nonc) {
335 symlink = cache_symlink_alloc(nnode->tn_size + 1, M_WAITOK);
336 symlink_smr = true;
337 }
338 if (symlink == NULL) {
339 symlink = malloc(nnode->tn_size + 1, M_TMPFSNAME, M_WAITOK);
340 symlink_smr = false;
341 }
342 memcpy(symlink, target, nnode->tn_size + 1);
343
344 /*
345 * Allow safe symlink resolving for lockless lookup.
346 * tmpfs_fplookup_symlink references this comment.
347 *
348 * 1. nnode is not yet visible to the world
349 * 2. both tn_link_target and tn_link_smr get populated
350 * 3. release fence publishes their content
351 * 4. tn_link_target content is immutable until node destruction,
352 * where the pointer gets set to NULL
353 * 5. tn_link_smr is never changed once set
354 *
355 * As a result it is sufficient to issue load consume on the node
356 * pointer to also get the above content in a stable manner.
357 * Worst case tn_link_smr flag may be set to true despite being stale,
358 * while the target buffer is already cleared out.
359 */
360 atomic_store_ptr(&nnode->tn_link_target, symlink);
361 atomic_store_char((char *)&nnode->tn_link_smr, symlink_smr);
362 atomic_thread_fence_rel();
363 break;
364
365 case VREG:
366 obj = nnode->tn_reg.tn_aobj =
367 vm_pager_allocate(OBJT_SWAP, NULL, 0, VM_PROT_DEFAULT, 0,
368 NULL /* XXXKIB - tmpfs needs swap reservation */);
369 VM_OBJECT_WLOCK(obj);
370 /* OBJ_TMPFS is set together with the setting of vp->v_object */
371 vm_object_set_flag(obj, OBJ_TMPFS_NODE);
372 VM_OBJECT_WUNLOCK(obj);
373 nnode->tn_reg.tn_tmp = tmp;
374 break;
375
376 default:
377 panic("tmpfs_alloc_node: type %p %d", nnode,
378 (int)nnode->tn_type);
379 }
380
381 TMPFS_LOCK(tmp);
382 LIST_INSERT_HEAD(&tmp->tm_nodes_used, nnode, tn_entries);
383 nnode->tn_attached = true;
384 tmp->tm_nodes_inuse++;
385 tmp->tm_refcount++;
386 TMPFS_UNLOCK(tmp);
387
388 *node = nnode;
389 return (0);
390 }
391
392 /*
393 * Destroys the node pointed to by node from the file system 'tmp'.
394 * If the node references a directory, no entries are allowed.
395 */
396 void
397 tmpfs_free_node(struct tmpfs_mount *tmp, struct tmpfs_node *node)
398 {
399 if (refcount_release_if_not_last(&node->tn_refcount))
400 return;
401
402 TMPFS_LOCK(tmp);
403 TMPFS_NODE_LOCK(node);
404 if (!tmpfs_free_node_locked(tmp, node, false)) {
405 TMPFS_NODE_UNLOCK(node);
406 TMPFS_UNLOCK(tmp);
407 }
408 }
409
410 bool
411 tmpfs_free_node_locked(struct tmpfs_mount *tmp, struct tmpfs_node *node,
412 bool detach)
413 {
414 vm_object_t uobj;
415 char *symlink;
416 bool last;
417
418 TMPFS_MP_ASSERT_LOCKED(tmp);
419 TMPFS_NODE_ASSERT_LOCKED(node);
420
421 last = refcount_release(&node->tn_refcount);
422 if (node->tn_attached && (detach || last)) {
423 MPASS(tmp->tm_nodes_inuse > 0);
424 tmp->tm_nodes_inuse--;
425 LIST_REMOVE(node, tn_entries);
426 node->tn_attached = false;
427 }
428 if (!last)
429 return (false);
430
431 #ifdef INVARIANTS
432 MPASS(node->tn_vnode == NULL);
433 MPASS((node->tn_vpstate & TMPFS_VNODE_ALLOCATING) == 0);
434 #endif
435 TMPFS_NODE_UNLOCK(node);
436 TMPFS_UNLOCK(tmp);
437
438 switch (node->tn_type) {
439 case VBLK:
440 /* FALLTHROUGH */
441 case VCHR:
442 /* FALLTHROUGH */
443 case VDIR:
444 /* FALLTHROUGH */
445 case VFIFO:
446 /* FALLTHROUGH */
447 case VSOCK:
448 break;
449
450 case VLNK:
451 symlink = node->tn_link_target;
452 atomic_store_ptr(&node->tn_link_target, NULL);
453 if (atomic_load_char(&node->tn_link_smr)) {
454 cache_symlink_free(symlink, node->tn_size + 1);
455 } else {
456 free(symlink, M_TMPFSNAME);
457 }
458 break;
459
460 case VREG:
461 uobj = node->tn_reg.tn_aobj;
462 if (uobj != NULL) {
463 if (uobj->size != 0)
464 atomic_subtract_long(&tmp->tm_pages_used, uobj->size);
465 KASSERT((uobj->flags & OBJ_TMPFS) == 0,
466 ("leaked OBJ_TMPFS node %p vm_obj %p", node, uobj));
467 vm_object_deallocate(uobj);
468 }
469 break;
470
471 default:
472 panic("tmpfs_free_node: type %p %d", node, (int)node->tn_type);
473 }
474
475 uma_zfree_smr(tmpfs_node_pool, node);
476 TMPFS_LOCK(tmp);
477 tmpfs_free_tmp(tmp);
478 return (true);
479 }
480
481 static __inline uint32_t
482 tmpfs_dirent_hash(const char *name, u_int len)
483 {
484 uint32_t hash;
485
486 hash = fnv_32_buf(name, len, FNV1_32_INIT + len) & TMPFS_DIRCOOKIE_MASK;
487 #ifdef TMPFS_DEBUG_DIRCOOKIE_DUP
488 hash &= 0xf;
489 #endif
490 if (hash < TMPFS_DIRCOOKIE_MIN)
491 hash += TMPFS_DIRCOOKIE_MIN;
492
493 return (hash);
494 }
495
496 static __inline off_t
497 tmpfs_dirent_cookie(struct tmpfs_dirent *de)
498 {
499 if (de == NULL)
500 return (TMPFS_DIRCOOKIE_EOF);
501
502 MPASS(de->td_cookie >= TMPFS_DIRCOOKIE_MIN);
503
504 return (de->td_cookie);
505 }
506
507 static __inline boolean_t
508 tmpfs_dirent_dup(struct tmpfs_dirent *de)
509 {
510 return ((de->td_cookie & TMPFS_DIRCOOKIE_DUP) != 0);
511 }
512
513 static __inline boolean_t
514 tmpfs_dirent_duphead(struct tmpfs_dirent *de)
515 {
516 return ((de->td_cookie & TMPFS_DIRCOOKIE_DUPHEAD) != 0);
517 }
518
519 void
520 tmpfs_dirent_init(struct tmpfs_dirent *de, const char *name, u_int namelen)
521 {
522 de->td_hash = de->td_cookie = tmpfs_dirent_hash(name, namelen);
523 memcpy(de->ud.td_name, name, namelen);
524 de->td_namelen = namelen;
525 }
526
527 /*
528 * Allocates a new directory entry for the node node with a name of name.
529 * The new directory entry is returned in *de.
530 *
531 * The link count of node is increased by one to reflect the new object
532 * referencing it.
533 *
534 * Returns zero on success or an appropriate error code on failure.
535 */
536 int
537 tmpfs_alloc_dirent(struct tmpfs_mount *tmp, struct tmpfs_node *node,
538 const char *name, u_int len, struct tmpfs_dirent **de)
539 {
540 struct tmpfs_dirent *nde;
541
542 nde = malloc(sizeof(*nde), M_TMPFSDIR, M_WAITOK);
543 nde->td_node = node;
544 if (name != NULL) {
545 nde->ud.td_name = malloc(len, M_TMPFSNAME, M_WAITOK);
546 tmpfs_dirent_init(nde, name, len);
547 } else
548 nde->td_namelen = 0;
549 if (node != NULL)
550 node->tn_links++;
551
552 *de = nde;
553
554 return 0;
555 }
556
557 /*
558 * Frees a directory entry. It is the caller's responsibility to destroy
559 * the node referenced by it if needed.
560 *
561 * The link count of node is decreased by one to reflect the removal of an
562 * object that referenced it. This only happens if 'node_exists' is true;
563 * otherwise the function will not access the node referred to by the
564 * directory entry, as it may already have been released from the outside.
565 */
566 void
567 tmpfs_free_dirent(struct tmpfs_mount *tmp, struct tmpfs_dirent *de)
568 {
569 struct tmpfs_node *node;
570
571 node = de->td_node;
572 if (node != NULL) {
573 MPASS(node->tn_links > 0);
574 node->tn_links--;
575 }
576 if (!tmpfs_dirent_duphead(de) && de->ud.td_name != NULL)
577 free(de->ud.td_name, M_TMPFSNAME);
578 free(de, M_TMPFSDIR);
579 }
580
581 void
582 tmpfs_destroy_vobject(struct vnode *vp, vm_object_t obj)
583 {
584
585 ASSERT_VOP_ELOCKED(vp, "tmpfs_destroy_vobject");
586 if (vp->v_type != VREG || obj == NULL)
587 return;
588
589 VM_OBJECT_WLOCK(obj);
590 VI_LOCK(vp);
591 vm_object_clear_flag(obj, OBJ_TMPFS);
592 obj->un_pager.swp.swp_tmpfs = NULL;
593 if (vp->v_writecount < 0)
594 vp->v_writecount = 0;
595 VI_UNLOCK(vp);
596 VM_OBJECT_WUNLOCK(obj);
597 }
598
599 /*
600 * Need to clear v_object for insmntque failure.
601 */
602 static void
603 tmpfs_insmntque_dtr(struct vnode *vp, void *dtr_arg)
604 {
605
606 tmpfs_destroy_vobject(vp, vp->v_object);
607 vp->v_object = NULL;
608 vp->v_data = NULL;
609 vp->v_op = &dead_vnodeops;
610 vgone(vp);
611 vput(vp);
612 }
613
614 /*
615 * Allocates a new vnode for the node node or returns a new reference to
616 * an existing one if the node had already a vnode referencing it. The
617 * resulting locked vnode is returned in *vpp.
618 *
619 * Returns zero on success or an appropriate error code on failure.
620 */
621 int
622 tmpfs_alloc_vp(struct mount *mp, struct tmpfs_node *node, int lkflag,
623 struct vnode **vpp)
624 {
625 struct vnode *vp;
626 enum vgetstate vs;
627 struct tmpfs_mount *tm;
628 vm_object_t object;
629 int error;
630
631 error = 0;
632 tm = VFS_TO_TMPFS(mp);
633 TMPFS_NODE_LOCK(node);
634 tmpfs_ref_node(node);
635 loop:
636 TMPFS_NODE_ASSERT_LOCKED(node);
637 if ((vp = node->tn_vnode) != NULL) {
638 MPASS((node->tn_vpstate & TMPFS_VNODE_DOOMED) == 0);
639 if ((node->tn_type == VDIR && node->tn_dir.tn_parent == NULL) ||
640 (VN_IS_DOOMED(vp) &&
641 (lkflag & LK_NOWAIT) != 0)) {
642 TMPFS_NODE_UNLOCK(node);
643 error = ENOENT;
644 vp = NULL;
645 goto out;
646 }
647 if (VN_IS_DOOMED(vp)) {
648 node->tn_vpstate |= TMPFS_VNODE_WRECLAIM;
649 while ((node->tn_vpstate & TMPFS_VNODE_WRECLAIM) != 0) {
650 msleep(&node->tn_vnode, TMPFS_NODE_MTX(node),
651 0, "tmpfsE", 0);
652 }
653 goto loop;
654 }
655 vs = vget_prep(vp);
656 TMPFS_NODE_UNLOCK(node);
657 error = vget_finish(vp, lkflag, vs);
658 if (error == ENOENT) {
659 TMPFS_NODE_LOCK(node);
660 goto loop;
661 }
662 if (error != 0) {
663 vp = NULL;
664 goto out;
665 }
666
667 /*
668 * Make sure the vnode is still there after
669 * getting the interlock to avoid racing a free.
670 */
671 if (node->tn_vnode == NULL || node->tn_vnode != vp) {
672 vput(vp);
673 TMPFS_NODE_LOCK(node);
674 goto loop;
675 }
676
677 goto out;
678 }
679
680 if ((node->tn_vpstate & TMPFS_VNODE_DOOMED) ||
681 (node->tn_type == VDIR && node->tn_dir.tn_parent == NULL)) {
682 TMPFS_NODE_UNLOCK(node);
683 error = ENOENT;
684 vp = NULL;
685 goto out;
686 }
687
688 /*
689 * otherwise lock the vp list while we call getnewvnode
690 * since that can block.
691 */
692 if (node->tn_vpstate & TMPFS_VNODE_ALLOCATING) {
693 node->tn_vpstate |= TMPFS_VNODE_WANT;
694 error = msleep((caddr_t) &node->tn_vpstate,
695 TMPFS_NODE_MTX(node), 0, "tmpfs_alloc_vp", 0);
696 if (error != 0)
697 goto out;
698 goto loop;
699 } else
700 node->tn_vpstate |= TMPFS_VNODE_ALLOCATING;
701
702 TMPFS_NODE_UNLOCK(node);
703
704 /* Get a new vnode and associate it with our node. */
705 error = getnewvnode("tmpfs", mp, VFS_TO_TMPFS(mp)->tm_nonc ?
706 &tmpfs_vnodeop_nonc_entries : &tmpfs_vnodeop_entries, &vp);
707 if (error != 0)
708 goto unlock;
709 MPASS(vp != NULL);
710
711 /* lkflag is ignored, the lock is exclusive */
712 (void) vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
713
714 vp->v_data = node;
715 vp->v_type = node->tn_type;
716
717 /* Type-specific initialization. */
718 switch (node->tn_type) {
719 case VBLK:
720 /* FALLTHROUGH */
721 case VCHR:
722 /* FALLTHROUGH */
723 case VLNK:
724 /* FALLTHROUGH */
725 case VSOCK:
726 break;
727 case VFIFO:
728 vp->v_op = &tmpfs_fifoop_entries;
729 break;
730 case VREG:
731 object = node->tn_reg.tn_aobj;
732 VM_OBJECT_WLOCK(object);
733 VI_LOCK(vp);
734 KASSERT(vp->v_object == NULL, ("Not NULL v_object in tmpfs"));
735 vp->v_object = object;
736 object->un_pager.swp.swp_tmpfs = vp;
737 vm_object_set_flag(object, OBJ_TMPFS);
738 vn_irflag_set_locked(vp, VIRF_PGREAD);
739 VI_UNLOCK(vp);
740 VM_OBJECT_WUNLOCK(object);
741 break;
742 case VDIR:
743 MPASS(node->tn_dir.tn_parent != NULL);
744 if (node->tn_dir.tn_parent == node)
745 vp->v_vflag |= VV_ROOT;
746 break;
747
748 default:
749 panic("tmpfs_alloc_vp: type %p %d", node, (int)node->tn_type);
750 }
751 if (vp->v_type != VFIFO)
752 VN_LOCK_ASHARE(vp);
753
754 error = insmntque1(vp, mp, tmpfs_insmntque_dtr, NULL);
755 if (error != 0)
756 vp = NULL;
757
758 unlock:
759 TMPFS_NODE_LOCK(node);
760
761 MPASS(node->tn_vpstate & TMPFS_VNODE_ALLOCATING);
762 node->tn_vpstate &= ~TMPFS_VNODE_ALLOCATING;
763 node->tn_vnode = vp;
764
765 if (node->tn_vpstate & TMPFS_VNODE_WANT) {
766 node->tn_vpstate &= ~TMPFS_VNODE_WANT;
767 TMPFS_NODE_UNLOCK(node);
768 wakeup((caddr_t) &node->tn_vpstate);
769 } else
770 TMPFS_NODE_UNLOCK(node);
771
772 out:
773 if (error == 0) {
774 *vpp = vp;
775
776 #ifdef INVARIANTS
777 MPASS(*vpp != NULL && VOP_ISLOCKED(*vpp));
778 TMPFS_NODE_LOCK(node);
779 MPASS(*vpp == node->tn_vnode);
780 TMPFS_NODE_UNLOCK(node);
781 #endif
782 }
783 tmpfs_free_node(tm, node);
784
785 return (error);
786 }
787
788 /*
789 * Destroys the association between the vnode vp and the node it
790 * references.
791 */
792 void
793 tmpfs_free_vp(struct vnode *vp)
794 {
795 struct tmpfs_node *node;
796
797 node = VP_TO_TMPFS_NODE(vp);
798
799 TMPFS_NODE_ASSERT_LOCKED(node);
800 node->tn_vnode = NULL;
801 if ((node->tn_vpstate & TMPFS_VNODE_WRECLAIM) != 0)
802 wakeup(&node->tn_vnode);
803 node->tn_vpstate &= ~TMPFS_VNODE_WRECLAIM;
804 vp->v_data = NULL;
805 }
806
807 /*
808 * Allocates a new file of type 'type' and adds it to the parent directory
809 * 'dvp'; this addition is done using the component name given in 'cnp'.
810 * The ownership of the new file is automatically assigned based on the
811 * credentials of the caller (through 'cnp'), the group is set based on
812 * the parent directory and the mode is determined from the 'vap' argument.
813 * If successful, *vpp holds a vnode to the newly created file and zero
814 * is returned. Otherwise *vpp is NULL and the function returns an
815 * appropriate error code.
816 */
817 int
818 tmpfs_alloc_file(struct vnode *dvp, struct vnode **vpp, struct vattr *vap,
819 struct componentname *cnp, const char *target)
820 {
821 int error;
822 struct tmpfs_dirent *de;
823 struct tmpfs_mount *tmp;
824 struct tmpfs_node *dnode;
825 struct tmpfs_node *node;
826 struct tmpfs_node *parent;
827
828 ASSERT_VOP_ELOCKED(dvp, "tmpfs_alloc_file");
829 MPASS(cnp->cn_flags & HASBUF);
830
831 tmp = VFS_TO_TMPFS(dvp->v_mount);
832 dnode = VP_TO_TMPFS_DIR(dvp);
833 *vpp = NULL;
834
835 /* If the entry we are creating is a directory, we cannot overflow
836 * the number of links of its parent, because it will get a new
837 * link. */
838 if (vap->va_type == VDIR) {
839 /* Ensure that we do not overflow the maximum number of links
840 * imposed by the system. */
841 MPASS(dnode->tn_links <= TMPFS_LINK_MAX);
842 if (dnode->tn_links == TMPFS_LINK_MAX) {
843 return (EMLINK);
844 }
845
846 parent = dnode;
847 MPASS(parent != NULL);
848 } else
849 parent = NULL;
850
851 /* Allocate a node that represents the new file. */
852 error = tmpfs_alloc_node(dvp->v_mount, tmp, vap->va_type,
853 cnp->cn_cred->cr_uid, dnode->tn_gid, vap->va_mode, parent,
854 target, vap->va_rdev, &node);
855 if (error != 0)
856 return (error);
857
858 /* Allocate a directory entry that points to the new file. */
859 error = tmpfs_alloc_dirent(tmp, node, cnp->cn_nameptr, cnp->cn_namelen,
860 &de);
861 if (error != 0) {
862 tmpfs_free_node(tmp, node);
863 return (error);
864 }
865
866 /* Allocate a vnode for the new file. */
867 error = tmpfs_alloc_vp(dvp->v_mount, node, LK_EXCLUSIVE, vpp);
868 if (error != 0) {
869 tmpfs_free_dirent(tmp, de);
870 tmpfs_free_node(tmp, node);
871 return (error);
872 }
873
874 /* Now that all required items are allocated, we can proceed to
875 * insert the new node into the directory, an operation that
876 * cannot fail. */
877 if (cnp->cn_flags & ISWHITEOUT)
878 tmpfs_dir_whiteout_remove(dvp, cnp);
879 tmpfs_dir_attach(dvp, de);
880 return (0);
881 }
882
883 struct tmpfs_dirent *
884 tmpfs_dir_first(struct tmpfs_node *dnode, struct tmpfs_dir_cursor *dc)
885 {
886 struct tmpfs_dirent *de;
887
888 de = RB_MIN(tmpfs_dir, &dnode->tn_dir.tn_dirhead);
889 dc->tdc_tree = de;
890 if (de != NULL && tmpfs_dirent_duphead(de))
891 de = LIST_FIRST(&de->ud.td_duphead);
892 dc->tdc_current = de;
893
894 return (dc->tdc_current);
895 }
896
897 struct tmpfs_dirent *
898 tmpfs_dir_next(struct tmpfs_node *dnode, struct tmpfs_dir_cursor *dc)
899 {
900 struct tmpfs_dirent *de;
901
902 MPASS(dc->tdc_tree != NULL);
903 if (tmpfs_dirent_dup(dc->tdc_current)) {
904 dc->tdc_current = LIST_NEXT(dc->tdc_current, uh.td_dup.entries);
905 if (dc->tdc_current != NULL)
906 return (dc->tdc_current);
907 }
908 dc->tdc_tree = dc->tdc_current = RB_NEXT(tmpfs_dir,
909 &dnode->tn_dir.tn_dirhead, dc->tdc_tree);
910 if ((de = dc->tdc_current) != NULL && tmpfs_dirent_duphead(de)) {
911 dc->tdc_current = LIST_FIRST(&de->ud.td_duphead);
912 MPASS(dc->tdc_current != NULL);
913 }
914
915 return (dc->tdc_current);
916 }
917
918 /* Lookup directory entry in RB-Tree. Function may return duphead entry. */
919 static struct tmpfs_dirent *
920 tmpfs_dir_xlookup_hash(struct tmpfs_node *dnode, uint32_t hash)
921 {
922 struct tmpfs_dirent *de, dekey;
923
924 dekey.td_hash = hash;
925 de = RB_FIND(tmpfs_dir, &dnode->tn_dir.tn_dirhead, &dekey);
926 return (de);
927 }
928
929 /* Lookup directory entry by cookie, initialize directory cursor accordingly. */
930 static struct tmpfs_dirent *
931 tmpfs_dir_lookup_cookie(struct tmpfs_node *node, off_t cookie,
932 struct tmpfs_dir_cursor *dc)
933 {
934 struct tmpfs_dir *dirhead = &node->tn_dir.tn_dirhead;
935 struct tmpfs_dirent *de, dekey;
936
937 MPASS(cookie >= TMPFS_DIRCOOKIE_MIN);
938
939 if (cookie == node->tn_dir.tn_readdir_lastn &&
940 (de = node->tn_dir.tn_readdir_lastp) != NULL) {
941 /* Protect against possible race, tn_readdir_last[pn]
942 * may be updated with only shared vnode lock held. */
943 if (cookie == tmpfs_dirent_cookie(de))
944 goto out;
945 }
946
947 if ((cookie & TMPFS_DIRCOOKIE_DUP) != 0) {
948 LIST_FOREACH(de, &node->tn_dir.tn_dupindex,
949 uh.td_dup.index_entries) {
950 MPASS(tmpfs_dirent_dup(de));
951 if (de->td_cookie == cookie)
952 goto out;
953 /* dupindex list is sorted. */
954 if (de->td_cookie < cookie) {
955 de = NULL;
956 goto out;
957 }
958 }
959 MPASS(de == NULL);
960 goto out;
961 }
962
963 if ((cookie & TMPFS_DIRCOOKIE_MASK) != cookie) {
964 de = NULL;
965 } else {
966 dekey.td_hash = cookie;
967 /* Recover if direntry for cookie was removed */
968 de = RB_NFIND(tmpfs_dir, dirhead, &dekey);
969 }
970 dc->tdc_tree = de;
971 dc->tdc_current = de;
972 if (de != NULL && tmpfs_dirent_duphead(de)) {
973 dc->tdc_current = LIST_FIRST(&de->ud.td_duphead);
974 MPASS(dc->tdc_current != NULL);
975 }
976 return (dc->tdc_current);
977
978 out:
979 dc->tdc_tree = de;
980 dc->tdc_current = de;
981 if (de != NULL && tmpfs_dirent_dup(de))
982 dc->tdc_tree = tmpfs_dir_xlookup_hash(node,
983 de->td_hash);
984 return (dc->tdc_current);
985 }
986
987 /*
988 * Looks for a directory entry in the directory represented by node.
989 * 'cnp' describes the name of the entry to look for. Note that the .
990 * and .. components are not allowed as they do not physically exist
991 * within directories.
992 *
993 * Returns a pointer to the entry when found, otherwise NULL.
994 */
995 struct tmpfs_dirent *
996 tmpfs_dir_lookup(struct tmpfs_node *node, struct tmpfs_node *f,
997 struct componentname *cnp)
998 {
999 struct tmpfs_dir_duphead *duphead;
1000 struct tmpfs_dirent *de;
1001 uint32_t hash;
1002
1003 MPASS(IMPLIES(cnp->cn_namelen == 1, cnp->cn_nameptr[0] != '.'));
1004 MPASS(IMPLIES(cnp->cn_namelen == 2, !(cnp->cn_nameptr[0] == '.' &&
1005 cnp->cn_nameptr[1] == '.')));
1006 TMPFS_VALIDATE_DIR(node);
1007
1008 hash = tmpfs_dirent_hash(cnp->cn_nameptr, cnp->cn_namelen);
1009 de = tmpfs_dir_xlookup_hash(node, hash);
1010 if (de != NULL && tmpfs_dirent_duphead(de)) {
1011 duphead = &de->ud.td_duphead;
1012 LIST_FOREACH(de, duphead, uh.td_dup.entries) {
1013 if (TMPFS_DIRENT_MATCHES(de, cnp->cn_nameptr,
1014 cnp->cn_namelen))
1015 break;
1016 }
1017 } else if (de != NULL) {
1018 if (!TMPFS_DIRENT_MATCHES(de, cnp->cn_nameptr,
1019 cnp->cn_namelen))
1020 de = NULL;
1021 }
1022 if (de != NULL && f != NULL && de->td_node != f)
1023 de = NULL;
1024
1025 return (de);
1026 }
1027
1028 /*
1029 * Attach duplicate-cookie directory entry nde to dnode and insert to dupindex
1030 * list, allocate new cookie value.
1031 */
1032 static void
1033 tmpfs_dir_attach_dup(struct tmpfs_node *dnode,
1034 struct tmpfs_dir_duphead *duphead, struct tmpfs_dirent *nde)
1035 {
1036 struct tmpfs_dir_duphead *dupindex;
1037 struct tmpfs_dirent *de, *pde;
1038
1039 dupindex = &dnode->tn_dir.tn_dupindex;
1040 de = LIST_FIRST(dupindex);
1041 if (de == NULL || de->td_cookie < TMPFS_DIRCOOKIE_DUP_MAX) {
1042 if (de == NULL)
1043 nde->td_cookie = TMPFS_DIRCOOKIE_DUP_MIN;
1044 else
1045 nde->td_cookie = de->td_cookie + 1;
1046 MPASS(tmpfs_dirent_dup(nde));
1047 LIST_INSERT_HEAD(dupindex, nde, uh.td_dup.index_entries);
1048 LIST_INSERT_HEAD(duphead, nde, uh.td_dup.entries);
1049 return;
1050 }
1051
1052 /*
1053 * Cookie numbers are near exhaustion. Scan dupindex list for unused
1054 * numbers. dupindex list is sorted in descending order. Keep it so
1055 * after inserting nde.
1056 */
1057 while (1) {
1058 pde = de;
1059 de = LIST_NEXT(de, uh.td_dup.index_entries);
1060 if (de == NULL && pde->td_cookie != TMPFS_DIRCOOKIE_DUP_MIN) {
1061 /*
1062 * Last element of the index doesn't have minimal cookie
1063 * value, use it.
1064 */
1065 nde->td_cookie = TMPFS_DIRCOOKIE_DUP_MIN;
1066 LIST_INSERT_AFTER(pde, nde, uh.td_dup.index_entries);
1067 LIST_INSERT_HEAD(duphead, nde, uh.td_dup.entries);
1068 return;
1069 } else if (de == NULL) {
1070 /*
1071 * We are so lucky have 2^30 hash duplicates in single
1072 * directory :) Return largest possible cookie value.
1073 * It should be fine except possible issues with
1074 * VOP_READDIR restart.
1075 */
1076 nde->td_cookie = TMPFS_DIRCOOKIE_DUP_MAX;
1077 LIST_INSERT_HEAD(dupindex, nde,
1078 uh.td_dup.index_entries);
1079 LIST_INSERT_HEAD(duphead, nde, uh.td_dup.entries);
1080 return;
1081 }
1082 if (de->td_cookie + 1 == pde->td_cookie ||
1083 de->td_cookie >= TMPFS_DIRCOOKIE_DUP_MAX)
1084 continue; /* No hole or invalid cookie. */
1085 nde->td_cookie = de->td_cookie + 1;
1086 MPASS(tmpfs_dirent_dup(nde));
1087 MPASS(pde->td_cookie > nde->td_cookie);
1088 MPASS(nde->td_cookie > de->td_cookie);
1089 LIST_INSERT_BEFORE(de, nde, uh.td_dup.index_entries);
1090 LIST_INSERT_HEAD(duphead, nde, uh.td_dup.entries);
1091 return;
1092 }
1093 }
1094
1095 /*
1096 * Attaches the directory entry de to the directory represented by vp.
1097 * Note that this does not change the link count of the node pointed by
1098 * the directory entry, as this is done by tmpfs_alloc_dirent.
1099 */
1100 void
1101 tmpfs_dir_attach(struct vnode *vp, struct tmpfs_dirent *de)
1102 {
1103 struct tmpfs_node *dnode;
1104 struct tmpfs_dirent *xde, *nde;
1105
1106 ASSERT_VOP_ELOCKED(vp, __func__);
1107 MPASS(de->td_namelen > 0);
1108 MPASS(de->td_hash >= TMPFS_DIRCOOKIE_MIN);
1109 MPASS(de->td_cookie == de->td_hash);
1110
1111 dnode = VP_TO_TMPFS_DIR(vp);
1112 dnode->tn_dir.tn_readdir_lastn = 0;
1113 dnode->tn_dir.tn_readdir_lastp = NULL;
1114
1115 MPASS(!tmpfs_dirent_dup(de));
1116 xde = RB_INSERT(tmpfs_dir, &dnode->tn_dir.tn_dirhead, de);
1117 if (xde != NULL && tmpfs_dirent_duphead(xde))
1118 tmpfs_dir_attach_dup(dnode, &xde->ud.td_duphead, de);
1119 else if (xde != NULL) {
1120 /*
1121 * Allocate new duphead. Swap xde with duphead to avoid
1122 * adding/removing elements with the same hash.
1123 */
1124 MPASS(!tmpfs_dirent_dup(xde));
1125 tmpfs_alloc_dirent(VFS_TO_TMPFS(vp->v_mount), NULL, NULL, 0,
1126 &nde);
1127 /* *nde = *xde; XXX gcc 4.2.1 may generate invalid code. */
1128 memcpy(nde, xde, sizeof(*xde));
1129 xde->td_cookie |= TMPFS_DIRCOOKIE_DUPHEAD;
1130 LIST_INIT(&xde->ud.td_duphead);
1131 xde->td_namelen = 0;
1132 xde->td_node = NULL;
1133 tmpfs_dir_attach_dup(dnode, &xde->ud.td_duphead, nde);
1134 tmpfs_dir_attach_dup(dnode, &xde->ud.td_duphead, de);
1135 }
1136 dnode->tn_size += sizeof(struct tmpfs_dirent);
1137 dnode->tn_status |= TMPFS_NODE_CHANGED | TMPFS_NODE_MODIFIED;
1138 dnode->tn_accessed = true;
1139 tmpfs_update(vp);
1140 }
1141
1142 /*
1143 * Detaches the directory entry de from the directory represented by vp.
1144 * Note that this does not change the link count of the node pointed by
1145 * the directory entry, as this is done by tmpfs_free_dirent.
1146 */
1147 void
1148 tmpfs_dir_detach(struct vnode *vp, struct tmpfs_dirent *de)
1149 {
1150 struct tmpfs_mount *tmp;
1151 struct tmpfs_dir *head;
1152 struct tmpfs_node *dnode;
1153 struct tmpfs_dirent *xde;
1154
1155 ASSERT_VOP_ELOCKED(vp, __func__);
1156
1157 dnode = VP_TO_TMPFS_DIR(vp);
1158 head = &dnode->tn_dir.tn_dirhead;
1159 dnode->tn_dir.tn_readdir_lastn = 0;
1160 dnode->tn_dir.tn_readdir_lastp = NULL;
1161
1162 if (tmpfs_dirent_dup(de)) {
1163 /* Remove duphead if de was last entry. */
1164 if (LIST_NEXT(de, uh.td_dup.entries) == NULL) {
1165 xde = tmpfs_dir_xlookup_hash(dnode, de->td_hash);
1166 MPASS(tmpfs_dirent_duphead(xde));
1167 } else
1168 xde = NULL;
1169 LIST_REMOVE(de, uh.td_dup.entries);
1170 LIST_REMOVE(de, uh.td_dup.index_entries);
1171 if (xde != NULL) {
1172 if (LIST_EMPTY(&xde->ud.td_duphead)) {
1173 RB_REMOVE(tmpfs_dir, head, xde);
1174 tmp = VFS_TO_TMPFS(vp->v_mount);
1175 MPASS(xde->td_node == NULL);
1176 tmpfs_free_dirent(tmp, xde);
1177 }
1178 }
1179 de->td_cookie = de->td_hash;
1180 } else
1181 RB_REMOVE(tmpfs_dir, head, de);
1182
1183 dnode->tn_size -= sizeof(struct tmpfs_dirent);
1184 dnode->tn_status |= TMPFS_NODE_CHANGED | TMPFS_NODE_MODIFIED;
1185 dnode->tn_accessed = true;
1186 tmpfs_update(vp);
1187 }
1188
1189 void
1190 tmpfs_dir_destroy(struct tmpfs_mount *tmp, struct tmpfs_node *dnode)
1191 {
1192 struct tmpfs_dirent *de, *dde, *nde;
1193
1194 RB_FOREACH_SAFE(de, tmpfs_dir, &dnode->tn_dir.tn_dirhead, nde) {
1195 RB_REMOVE(tmpfs_dir, &dnode->tn_dir.tn_dirhead, de);
1196 /* Node may already be destroyed. */
1197 de->td_node = NULL;
1198 if (tmpfs_dirent_duphead(de)) {
1199 while ((dde = LIST_FIRST(&de->ud.td_duphead)) != NULL) {
1200 LIST_REMOVE(dde, uh.td_dup.entries);
1201 dde->td_node = NULL;
1202 tmpfs_free_dirent(tmp, dde);
1203 }
1204 }
1205 tmpfs_free_dirent(tmp, de);
1206 }
1207 }
1208
1209 /*
1210 * Helper function for tmpfs_readdir. Creates a '.' entry for the given
1211 * directory and returns it in the uio space. The function returns 0
1212 * on success, -1 if there was not enough space in the uio structure to
1213 * hold the directory entry or an appropriate error code if another
1214 * error happens.
1215 */
1216 static int
1217 tmpfs_dir_getdotdent(struct tmpfs_mount *tm, struct tmpfs_node *node,
1218 struct uio *uio)
1219 {
1220 int error;
1221 struct dirent dent;
1222
1223 TMPFS_VALIDATE_DIR(node);
1224 MPASS(uio->uio_offset == TMPFS_DIRCOOKIE_DOT);
1225
1226 dent.d_fileno = node->tn_id;
1227 dent.d_off = TMPFS_DIRCOOKIE_DOTDOT;
1228 dent.d_type = DT_DIR;
1229 dent.d_namlen = 1;
1230 dent.d_name[0] = '.';
1231 dent.d_reclen = GENERIC_DIRSIZ(&dent);
1232 dirent_terminate(&dent);
1233
1234 if (dent.d_reclen > uio->uio_resid)
1235 error = EJUSTRETURN;
1236 else
1237 error = uiomove(&dent, dent.d_reclen, uio);
1238
1239 tmpfs_set_accessed(tm, node);
1240
1241 return (error);
1242 }
1243
1244 /*
1245 * Helper function for tmpfs_readdir. Creates a '..' entry for the given
1246 * directory and returns it in the uio space. The function returns 0
1247 * on success, -1 if there was not enough space in the uio structure to
1248 * hold the directory entry or an appropriate error code if another
1249 * error happens.
1250 */
1251 static int
1252 tmpfs_dir_getdotdotdent(struct tmpfs_mount *tm, struct tmpfs_node *node,
1253 struct uio *uio, off_t next)
1254 {
1255 struct tmpfs_node *parent;
1256 struct dirent dent;
1257 int error;
1258
1259 TMPFS_VALIDATE_DIR(node);
1260 MPASS(uio->uio_offset == TMPFS_DIRCOOKIE_DOTDOT);
1261
1262 /*
1263 * Return ENOENT if the current node is already removed.
1264 */
1265 TMPFS_ASSERT_LOCKED(node);
1266 parent = node->tn_dir.tn_parent;
1267 if (parent == NULL)
1268 return (ENOENT);
1269
1270 TMPFS_NODE_LOCK(parent);
1271 dent.d_fileno = parent->tn_id;
1272 TMPFS_NODE_UNLOCK(parent);
1273
1274 dent.d_off = next;
1275 dent.d_type = DT_DIR;
1276 dent.d_namlen = 2;
1277 dent.d_name[0] = '.';
1278 dent.d_name[1] = '.';
1279 dent.d_reclen = GENERIC_DIRSIZ(&dent);
1280 dirent_terminate(&dent);
1281
1282 if (dent.d_reclen > uio->uio_resid)
1283 error = EJUSTRETURN;
1284 else
1285 error = uiomove(&dent, dent.d_reclen, uio);
1286
1287 tmpfs_set_accessed(tm, node);
1288
1289 return (error);
1290 }
1291
1292 /*
1293 * Helper function for tmpfs_readdir. Returns as much directory entries
1294 * as can fit in the uio space. The read starts at uio->uio_offset.
1295 * The function returns 0 on success, -1 if there was not enough space
1296 * in the uio structure to hold the directory entry or an appropriate
1297 * error code if another error happens.
1298 */
1299 int
1300 tmpfs_dir_getdents(struct tmpfs_mount *tm, struct tmpfs_node *node,
1301 struct uio *uio, int maxcookies, u_long *cookies, int *ncookies)
1302 {
1303 struct tmpfs_dir_cursor dc;
1304 struct tmpfs_dirent *de, *nde;
1305 off_t off;
1306 int error;
1307
1308 TMPFS_VALIDATE_DIR(node);
1309
1310 off = 0;
1311
1312 /*
1313 * Lookup the node from the current offset. The starting offset of
1314 * 0 will lookup both '.' and '..', and then the first real entry,
1315 * or EOF if there are none. Then find all entries for the dir that
1316 * fit into the buffer. Once no more entries are found (de == NULL),
1317 * the offset is set to TMPFS_DIRCOOKIE_EOF, which will cause the next
1318 * call to return 0.
1319 */
1320 switch (uio->uio_offset) {
1321 case TMPFS_DIRCOOKIE_DOT:
1322 error = tmpfs_dir_getdotdent(tm, node, uio);
1323 if (error != 0)
1324 return (error);
1325 uio->uio_offset = off = TMPFS_DIRCOOKIE_DOTDOT;
1326 if (cookies != NULL)
1327 cookies[(*ncookies)++] = off;
1328 /* FALLTHROUGH */
1329 case TMPFS_DIRCOOKIE_DOTDOT:
1330 de = tmpfs_dir_first(node, &dc);
1331 off = tmpfs_dirent_cookie(de);
1332 error = tmpfs_dir_getdotdotdent(tm, node, uio, off);
1333 if (error != 0)
1334 return (error);
1335 uio->uio_offset = off;
1336 if (cookies != NULL)
1337 cookies[(*ncookies)++] = off;
1338 /* EOF. */
1339 if (de == NULL)
1340 return (0);
1341 break;
1342 case TMPFS_DIRCOOKIE_EOF:
1343 return (0);
1344 default:
1345 de = tmpfs_dir_lookup_cookie(node, uio->uio_offset, &dc);
1346 if (de == NULL)
1347 return (EINVAL);
1348 if (cookies != NULL)
1349 off = tmpfs_dirent_cookie(de);
1350 }
1351
1352 /*
1353 * Read as much entries as possible; i.e., until we reach the end of the
1354 * directory or we exhaust uio space.
1355 */
1356 do {
1357 struct dirent d;
1358
1359 /*
1360 * Create a dirent structure representing the current tmpfs_node
1361 * and fill it.
1362 */
1363 if (de->td_node == NULL) {
1364 d.d_fileno = 1;
1365 d.d_type = DT_WHT;
1366 } else {
1367 d.d_fileno = de->td_node->tn_id;
1368 switch (de->td_node->tn_type) {
1369 case VBLK:
1370 d.d_type = DT_BLK;
1371 break;
1372
1373 case VCHR:
1374 d.d_type = DT_CHR;
1375 break;
1376
1377 case VDIR:
1378 d.d_type = DT_DIR;
1379 break;
1380
1381 case VFIFO:
1382 d.d_type = DT_FIFO;
1383 break;
1384
1385 case VLNK:
1386 d.d_type = DT_LNK;
1387 break;
1388
1389 case VREG:
1390 d.d_type = DT_REG;
1391 break;
1392
1393 case VSOCK:
1394 d.d_type = DT_SOCK;
1395 break;
1396
1397 default:
1398 panic("tmpfs_dir_getdents: type %p %d",
1399 de->td_node, (int)de->td_node->tn_type);
1400 }
1401 }
1402 d.d_namlen = de->td_namelen;
1403 MPASS(de->td_namelen < sizeof(d.d_name));
1404 (void)memcpy(d.d_name, de->ud.td_name, de->td_namelen);
1405 d.d_reclen = GENERIC_DIRSIZ(&d);
1406
1407 /*
1408 * Stop reading if the directory entry we are treating is bigger
1409 * than the amount of data that can be returned.
1410 */
1411 if (d.d_reclen > uio->uio_resid) {
1412 error = EJUSTRETURN;
1413 break;
1414 }
1415
1416 nde = tmpfs_dir_next(node, &dc);
1417 d.d_off = tmpfs_dirent_cookie(nde);
1418 dirent_terminate(&d);
1419
1420 /*
1421 * Copy the new dirent structure into the output buffer and
1422 * advance pointers.
1423 */
1424 error = uiomove(&d, d.d_reclen, uio);
1425 if (error == 0) {
1426 de = nde;
1427 if (cookies != NULL) {
1428 off = tmpfs_dirent_cookie(de);
1429 MPASS(*ncookies < maxcookies);
1430 cookies[(*ncookies)++] = off;
1431 }
1432 }
1433 } while (error == 0 && uio->uio_resid > 0 && de != NULL);
1434
1435 /* Skip setting off when using cookies as it is already done above. */
1436 if (cookies == NULL)
1437 off = tmpfs_dirent_cookie(de);
1438
1439 /* Update the offset and cache. */
1440 uio->uio_offset = off;
1441 node->tn_dir.tn_readdir_lastn = off;
1442 node->tn_dir.tn_readdir_lastp = de;
1443
1444 tmpfs_set_accessed(tm, node);
1445 return (error);
1446 }
1447
1448 int
1449 tmpfs_dir_whiteout_add(struct vnode *dvp, struct componentname *cnp)
1450 {
1451 struct tmpfs_dirent *de;
1452 int error;
1453
1454 error = tmpfs_alloc_dirent(VFS_TO_TMPFS(dvp->v_mount), NULL,
1455 cnp->cn_nameptr, cnp->cn_namelen, &de);
1456 if (error != 0)
1457 return (error);
1458 tmpfs_dir_attach(dvp, de);
1459 return (0);
1460 }
1461
1462 void
1463 tmpfs_dir_whiteout_remove(struct vnode *dvp, struct componentname *cnp)
1464 {
1465 struct tmpfs_dirent *de;
1466
1467 de = tmpfs_dir_lookup(VP_TO_TMPFS_DIR(dvp), NULL, cnp);
1468 MPASS(de != NULL && de->td_node == NULL);
1469 tmpfs_dir_detach(dvp, de);
1470 tmpfs_free_dirent(VFS_TO_TMPFS(dvp->v_mount), de);
1471 }
1472
1473 /*
1474 * Resizes the aobj associated with the regular file pointed to by 'vp' to the
1475 * size 'newsize'. 'vp' must point to a vnode that represents a regular file.
1476 * 'newsize' must be positive.
1477 *
1478 * Returns zero on success or an appropriate error code on failure.
1479 */
1480 int
1481 tmpfs_reg_resize(struct vnode *vp, off_t newsize, boolean_t ignerr)
1482 {
1483 struct tmpfs_mount *tmp;
1484 struct tmpfs_node *node;
1485 vm_object_t uobj;
1486 vm_page_t m;
1487 vm_pindex_t idx, newpages, oldpages;
1488 off_t oldsize;
1489 int base, rv;
1490
1491 MPASS(vp->v_type == VREG);
1492 MPASS(newsize >= 0);
1493
1494 node = VP_TO_TMPFS_NODE(vp);
1495 uobj = node->tn_reg.tn_aobj;
1496 tmp = VFS_TO_TMPFS(vp->v_mount);
1497
1498 /*
1499 * Convert the old and new sizes to the number of pages needed to
1500 * store them. It may happen that we do not need to do anything
1501 * because the last allocated page can accommodate the change on
1502 * its own.
1503 */
1504 oldsize = node->tn_size;
1505 oldpages = OFF_TO_IDX(oldsize + PAGE_MASK);
1506 MPASS(oldpages == uobj->size);
1507 newpages = OFF_TO_IDX(newsize + PAGE_MASK);
1508
1509 if (__predict_true(newpages == oldpages && newsize >= oldsize)) {
1510 node->tn_size = newsize;
1511 return (0);
1512 }
1513
1514 if (newpages > oldpages &&
1515 tmpfs_pages_check_avail(tmp, newpages - oldpages) == 0)
1516 return (ENOSPC);
1517
1518 VM_OBJECT_WLOCK(uobj);
1519 if (newsize < oldsize) {
1520 /*
1521 * Zero the truncated part of the last page.
1522 */
1523 base = newsize & PAGE_MASK;
1524 if (base != 0) {
1525 idx = OFF_TO_IDX(newsize);
1526 retry:
1527 m = vm_page_grab(uobj, idx, VM_ALLOC_NOCREAT);
1528 if (m != NULL) {
1529 MPASS(vm_page_all_valid(m));
1530 } else if (vm_pager_has_page(uobj, idx, NULL, NULL)) {
1531 m = vm_page_alloc(uobj, idx, VM_ALLOC_NORMAL |
1532 VM_ALLOC_WAITFAIL);
1533 if (m == NULL)
1534 goto retry;
1535 vm_object_pip_add(uobj, 1);
1536 VM_OBJECT_WUNLOCK(uobj);
1537 rv = vm_pager_get_pages(uobj, &m, 1, NULL,
1538 NULL);
1539 VM_OBJECT_WLOCK(uobj);
1540 vm_object_pip_wakeup(uobj);
1541 if (rv == VM_PAGER_OK) {
1542 /*
1543 * Since the page was not resident,
1544 * and therefore not recently
1545 * accessed, immediately enqueue it
1546 * for asynchronous laundering. The
1547 * current operation is not regarded
1548 * as an access.
1549 */
1550 vm_page_launder(m);
1551 } else {
1552 vm_page_free(m);
1553 if (ignerr)
1554 m = NULL;
1555 else {
1556 VM_OBJECT_WUNLOCK(uobj);
1557 return (EIO);
1558 }
1559 }
1560 }
1561 if (m != NULL) {
1562 pmap_zero_page_area(m, base, PAGE_SIZE - base);
1563 vm_page_set_dirty(m);
1564 vm_page_xunbusy(m);
1565 }
1566 }
1567
1568 /*
1569 * Release any swap space and free any whole pages.
1570 */
1571 if (newpages < oldpages)
1572 vm_object_page_remove(uobj, newpages, 0, 0);
1573 }
1574 uobj->size = newpages;
1575 VM_OBJECT_WUNLOCK(uobj);
1576
1577 atomic_add_long(&tmp->tm_pages_used, newpages - oldpages);
1578
1579 node->tn_size = newsize;
1580 return (0);
1581 }
1582
1583 void
1584 tmpfs_check_mtime(struct vnode *vp)
1585 {
1586 struct tmpfs_node *node;
1587 struct vm_object *obj;
1588
1589 ASSERT_VOP_ELOCKED(vp, "check_mtime");
1590 if (vp->v_type != VREG)
1591 return;
1592 obj = vp->v_object;
1593 KASSERT((obj->flags & (OBJ_TMPFS_NODE | OBJ_TMPFS)) ==
1594 (OBJ_TMPFS_NODE | OBJ_TMPFS), ("non-tmpfs obj"));
1595 /* unlocked read */
1596 if (obj->generation != obj->cleangeneration) {
1597 VM_OBJECT_WLOCK(obj);
1598 if (obj->generation != obj->cleangeneration) {
1599 obj->cleangeneration = obj->generation;
1600 node = VP_TO_TMPFS_NODE(vp);
1601 node->tn_status |= TMPFS_NODE_MODIFIED |
1602 TMPFS_NODE_CHANGED;
1603 }
1604 VM_OBJECT_WUNLOCK(obj);
1605 }
1606 }
1607
1608 /*
1609 * Change flags of the given vnode.
1610 * Caller should execute tmpfs_update on vp after a successful execution.
1611 * The vnode must be locked on entry and remain locked on exit.
1612 */
1613 int
1614 tmpfs_chflags(struct vnode *vp, u_long flags, struct ucred *cred,
1615 struct thread *p)
1616 {
1617 int error;
1618 struct tmpfs_node *node;
1619
1620 ASSERT_VOP_ELOCKED(vp, "chflags");
1621
1622 node = VP_TO_TMPFS_NODE(vp);
1623
1624 if ((flags & ~(SF_APPEND | SF_ARCHIVED | SF_IMMUTABLE | SF_NOUNLINK |
1625 UF_APPEND | UF_ARCHIVE | UF_HIDDEN | UF_IMMUTABLE | UF_NODUMP |
1626 UF_NOUNLINK | UF_OFFLINE | UF_OPAQUE | UF_READONLY | UF_REPARSE |
1627 UF_SPARSE | UF_SYSTEM)) != 0)
1628 return (EOPNOTSUPP);
1629
1630 /* Disallow this operation if the file system is mounted read-only. */
1631 if (vp->v_mount->mnt_flag & MNT_RDONLY)
1632 return (EROFS);
1633
1634 /*
1635 * Callers may only modify the file flags on objects they
1636 * have VADMIN rights for.
1637 */
1638 if ((error = VOP_ACCESS(vp, VADMIN, cred, p)))
1639 return (error);
1640 /*
1641 * Unprivileged processes are not permitted to unset system
1642 * flags, or modify flags if any system flags are set.
1643 */
1644 if (!priv_check_cred(cred, PRIV_VFS_SYSFLAGS)) {
1645 if (node->tn_flags &
1646 (SF_NOUNLINK | SF_IMMUTABLE | SF_APPEND)) {
1647 error = securelevel_gt(cred, 0);
1648 if (error)
1649 return (error);
1650 }
1651 } else {
1652 if (node->tn_flags &
1653 (SF_NOUNLINK | SF_IMMUTABLE | SF_APPEND) ||
1654 ((flags ^ node->tn_flags) & SF_SETTABLE))
1655 return (EPERM);
1656 }
1657 node->tn_flags = flags;
1658 node->tn_status |= TMPFS_NODE_CHANGED;
1659
1660 ASSERT_VOP_ELOCKED(vp, "chflags2");
1661
1662 return (0);
1663 }
1664
1665 /*
1666 * Change access mode on the given vnode.
1667 * Caller should execute tmpfs_update on vp after a successful execution.
1668 * The vnode must be locked on entry and remain locked on exit.
1669 */
1670 int
1671 tmpfs_chmod(struct vnode *vp, mode_t mode, struct ucred *cred, struct thread *p)
1672 {
1673 int error;
1674 struct tmpfs_node *node;
1675 mode_t newmode;
1676
1677 ASSERT_VOP_ELOCKED(vp, "chmod");
1678 ASSERT_VOP_IN_SEQC(vp);
1679
1680 node = VP_TO_TMPFS_NODE(vp);
1681
1682 /* Disallow this operation if the file system is mounted read-only. */
1683 if (vp->v_mount->mnt_flag & MNT_RDONLY)
1684 return EROFS;
1685
1686 /* Immutable or append-only files cannot be modified, either. */
1687 if (node->tn_flags & (IMMUTABLE | APPEND))
1688 return EPERM;
1689
1690 /*
1691 * To modify the permissions on a file, must possess VADMIN
1692 * for that file.
1693 */
1694 if ((error = VOP_ACCESS(vp, VADMIN, cred, p)))
1695 return (error);
1696
1697 /*
1698 * Privileged processes may set the sticky bit on non-directories,
1699 * as well as set the setgid bit on a file with a group that the
1700 * process is not a member of.
1701 */
1702 if (vp->v_type != VDIR && (mode & S_ISTXT)) {
1703 if (priv_check_cred(cred, PRIV_VFS_STICKYFILE))
1704 return (EFTYPE);
1705 }
1706 if (!groupmember(node->tn_gid, cred) && (mode & S_ISGID)) {
1707 error = priv_check_cred(cred, PRIV_VFS_SETGID);
1708 if (error)
1709 return (error);
1710 }
1711
1712 newmode = node->tn_mode & ~ALLPERMS;
1713 newmode |= mode & ALLPERMS;
1714 atomic_store_short(&node->tn_mode, newmode);
1715
1716 node->tn_status |= TMPFS_NODE_CHANGED;
1717
1718 ASSERT_VOP_ELOCKED(vp, "chmod2");
1719
1720 return (0);
1721 }
1722
1723 /*
1724 * Change ownership of the given vnode. At least one of uid or gid must
1725 * be different than VNOVAL. If one is set to that value, the attribute
1726 * is unchanged.
1727 * Caller should execute tmpfs_update on vp after a successful execution.
1728 * The vnode must be locked on entry and remain locked on exit.
1729 */
1730 int
1731 tmpfs_chown(struct vnode *vp, uid_t uid, gid_t gid, struct ucred *cred,
1732 struct thread *p)
1733 {
1734 int error;
1735 struct tmpfs_node *node;
1736 uid_t ouid;
1737 gid_t ogid;
1738 mode_t newmode;
1739
1740 ASSERT_VOP_ELOCKED(vp, "chown");
1741 ASSERT_VOP_IN_SEQC(vp);
1742
1743 node = VP_TO_TMPFS_NODE(vp);
1744
1745 /* Assign default values if they are unknown. */
1746 MPASS(uid != VNOVAL || gid != VNOVAL);
1747 if (uid == VNOVAL)
1748 uid = node->tn_uid;
1749 if (gid == VNOVAL)
1750 gid = node->tn_gid;
1751 MPASS(uid != VNOVAL && gid != VNOVAL);
1752
1753 /* Disallow this operation if the file system is mounted read-only. */
1754 if (vp->v_mount->mnt_flag & MNT_RDONLY)
1755 return (EROFS);
1756
1757 /* Immutable or append-only files cannot be modified, either. */
1758 if (node->tn_flags & (IMMUTABLE | APPEND))
1759 return (EPERM);
1760
1761 /*
1762 * To modify the ownership of a file, must possess VADMIN for that
1763 * file.
1764 */
1765 if ((error = VOP_ACCESS(vp, VADMIN, cred, p)))
1766 return (error);
1767
1768 /*
1769 * To change the owner of a file, or change the group of a file to a
1770 * group of which we are not a member, the caller must have
1771 * privilege.
1772 */
1773 if ((uid != node->tn_uid ||
1774 (gid != node->tn_gid && !groupmember(gid, cred))) &&
1775 (error = priv_check_cred(cred, PRIV_VFS_CHOWN)))
1776 return (error);
1777
1778 ogid = node->tn_gid;
1779 ouid = node->tn_uid;
1780
1781 node->tn_uid = uid;
1782 node->tn_gid = gid;
1783
1784 node->tn_status |= TMPFS_NODE_CHANGED;
1785
1786 if ((node->tn_mode & (S_ISUID | S_ISGID)) && (ouid != uid || ogid != gid)) {
1787 if (priv_check_cred(cred, PRIV_VFS_RETAINSUGID)) {
1788 newmode = node->tn_mode & ~(S_ISUID | S_ISGID);
1789 atomic_store_short(&node->tn_mode, newmode);
1790 }
1791 }
1792
1793 ASSERT_VOP_ELOCKED(vp, "chown2");
1794
1795 return (0);
1796 }
1797
1798 /*
1799 * Change size of the given vnode.
1800 * Caller should execute tmpfs_update on vp after a successful execution.
1801 * The vnode must be locked on entry and remain locked on exit.
1802 */
1803 int
1804 tmpfs_chsize(struct vnode *vp, u_quad_t size, struct ucred *cred,
1805 struct thread *p)
1806 {
1807 int error;
1808 struct tmpfs_node *node;
1809
1810 ASSERT_VOP_ELOCKED(vp, "chsize");
1811
1812 node = VP_TO_TMPFS_NODE(vp);
1813
1814 /* Decide whether this is a valid operation based on the file type. */
1815 error = 0;
1816 switch (vp->v_type) {
1817 case VDIR:
1818 return (EISDIR);
1819
1820 case VREG:
1821 if (vp->v_mount->mnt_flag & MNT_RDONLY)
1822 return (EROFS);
1823 break;
1824
1825 case VBLK:
1826 /* FALLTHROUGH */
1827 case VCHR:
1828 /* FALLTHROUGH */
1829 case VFIFO:
1830 /*
1831 * Allow modifications of special files even if in the file
1832 * system is mounted read-only (we are not modifying the
1833 * files themselves, but the objects they represent).
1834 */
1835 return (0);
1836
1837 default:
1838 /* Anything else is unsupported. */
1839 return (EOPNOTSUPP);
1840 }
1841
1842 /* Immutable or append-only files cannot be modified, either. */
1843 if (node->tn_flags & (IMMUTABLE | APPEND))
1844 return (EPERM);
1845
1846 error = tmpfs_truncate(vp, size);
1847 /*
1848 * tmpfs_truncate will raise the NOTE_EXTEND and NOTE_ATTRIB kevents
1849 * for us, as will update tn_status; no need to do that here.
1850 */
1851
1852 ASSERT_VOP_ELOCKED(vp, "chsize2");
1853
1854 return (error);
1855 }
1856
1857 /*
1858 * Change access and modification times of the given vnode.
1859 * Caller should execute tmpfs_update on vp after a successful execution.
1860 * The vnode must be locked on entry and remain locked on exit.
1861 */
1862 int
1863 tmpfs_chtimes(struct vnode *vp, struct vattr *vap,
1864 struct ucred *cred, struct thread *l)
1865 {
1866 int error;
1867 struct tmpfs_node *node;
1868
1869 ASSERT_VOP_ELOCKED(vp, "chtimes");
1870
1871 node = VP_TO_TMPFS_NODE(vp);
1872
1873 /* Disallow this operation if the file system is mounted read-only. */
1874 if (vp->v_mount->mnt_flag & MNT_RDONLY)
1875 return (EROFS);
1876
1877 /* Immutable or append-only files cannot be modified, either. */
1878 if (node->tn_flags & (IMMUTABLE | APPEND))
1879 return (EPERM);
1880
1881 error = vn_utimes_perm(vp, vap, cred, l);
1882 if (error != 0)
1883 return (error);
1884
1885 if (vap->va_atime.tv_sec != VNOVAL)
1886 node->tn_accessed = true;
1887
1888 if (vap->va_mtime.tv_sec != VNOVAL)
1889 node->tn_status |= TMPFS_NODE_MODIFIED;
1890
1891 if (vap->va_birthtime.tv_sec != VNOVAL)
1892 node->tn_status |= TMPFS_NODE_MODIFIED;
1893
1894 tmpfs_itimes(vp, &vap->va_atime, &vap->va_mtime);
1895
1896 if (vap->va_birthtime.tv_sec != VNOVAL)
1897 node->tn_birthtime = vap->va_birthtime;
1898 ASSERT_VOP_ELOCKED(vp, "chtimes2");
1899
1900 return (0);
1901 }
1902
1903 void
1904 tmpfs_set_status(struct tmpfs_mount *tm, struct tmpfs_node *node, int status)
1905 {
1906
1907 if ((node->tn_status & status) == status || tm->tm_ronly)
1908 return;
1909 TMPFS_NODE_LOCK(node);
1910 node->tn_status |= status;
1911 TMPFS_NODE_UNLOCK(node);
1912 }
1913
1914 void
1915 tmpfs_set_accessed(struct tmpfs_mount *tm, struct tmpfs_node *node)
1916 {
1917 if (node->tn_accessed || tm->tm_ronly)
1918 return;
1919 atomic_store_8(&node->tn_accessed, true);
1920 }
1921
1922 /* Sync timestamps */
1923 void
1924 tmpfs_itimes(struct vnode *vp, const struct timespec *acc,
1925 const struct timespec *mod)
1926 {
1927 struct tmpfs_node *node;
1928 struct timespec now;
1929
1930 ASSERT_VOP_LOCKED(vp, "tmpfs_itimes");
1931 node = VP_TO_TMPFS_NODE(vp);
1932
1933 if (!node->tn_accessed &&
1934 (node->tn_status & (TMPFS_NODE_MODIFIED | TMPFS_NODE_CHANGED)) == 0)
1935 return;
1936
1937 vfs_timestamp(&now);
1938 TMPFS_NODE_LOCK(node);
1939 if (node->tn_accessed) {
1940 if (acc == NULL)
1941 acc = &now;
1942 node->tn_atime = *acc;
1943 }
1944 if (node->tn_status & TMPFS_NODE_MODIFIED) {
1945 if (mod == NULL)
1946 mod = &now;
1947 node->tn_mtime = *mod;
1948 }
1949 if (node->tn_status & TMPFS_NODE_CHANGED)
1950 node->tn_ctime = now;
1951 node->tn_status &= ~(TMPFS_NODE_MODIFIED | TMPFS_NODE_CHANGED);
1952 node->tn_accessed = false;
1953 TMPFS_NODE_UNLOCK(node);
1954
1955 /* XXX: FIX? The entropy here is desirable, but the harvesting may be expensive */
1956 random_harvest_queue(node, sizeof(*node), RANDOM_FS_ATIME);
1957 }
1958
1959 int
1960 tmpfs_truncate(struct vnode *vp, off_t length)
1961 {
1962 int error;
1963 struct tmpfs_node *node;
1964
1965 node = VP_TO_TMPFS_NODE(vp);
1966
1967 if (length < 0) {
1968 error = EINVAL;
1969 goto out;
1970 }
1971
1972 if (node->tn_size == length) {
1973 error = 0;
1974 goto out;
1975 }
1976
1977 if (length > VFS_TO_TMPFS(vp->v_mount)->tm_maxfilesize)
1978 return (EFBIG);
1979
1980 error = tmpfs_reg_resize(vp, length, FALSE);
1981 if (error == 0)
1982 node->tn_status |= TMPFS_NODE_CHANGED | TMPFS_NODE_MODIFIED;
1983
1984 out:
1985 tmpfs_update(vp);
1986
1987 return (error);
1988 }
1989
1990 static __inline int
1991 tmpfs_dirtree_cmp(struct tmpfs_dirent *a, struct tmpfs_dirent *b)
1992 {
1993 if (a->td_hash > b->td_hash)
1994 return (1);
1995 else if (a->td_hash < b->td_hash)
1996 return (-1);
1997 return (0);
1998 }
1999
2000 RB_GENERATE_STATIC(tmpfs_dir, tmpfs_dirent, uh.td_entries, tmpfs_dirtree_cmp);
Cache object: 6488fe738d5f4b455b793cda85030dd4
|