1 /* $NetBSD: tmpfs_subr.c,v 1.35 2007/07/09 21:10:50 ad Exp $ */
2
3 /*-
4 * Copyright (c) 2005 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Julio M. Merino Vidal, developed as part of Google's Summer of Code
9 * 2005 program.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
22 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
23 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
24 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30 * POSSIBILITY OF SUCH DAMAGE.
31 */
32
33 /*
34 * Efficient memory file system supporting functions.
35 */
36
37 #include <sys/kernel.h>
38 #include <sys/param.h>
39 #include <sys/caps.h>
40 #include <sys/proc.h>
41 #include <sys/stat.h>
42 #include <sys/systm.h>
43 #include <sys/vnode.h>
44 #include <sys/vmmeter.h>
45 #include <sys/malloc.h>
46
47 #include <vm/vm.h>
48 #include <vm/vm_object.h>
49 #include <vm/vm_page.h>
50 #include <vm/vm_pager.h>
51 #include <vm/vm_extern.h>
52 #include <vm/vm_pageout.h>
53 #include <vm/vm_page2.h>
54
55 #include <vfs/tmpfs/tmpfs.h>
56 #include <vfs/tmpfs/tmpfs_vnops.h>
57
58 static ino_t tmpfs_fetch_ino(struct tmpfs_mount *);
59
60 static int tmpfs_dirtree_compare(struct tmpfs_dirent *a,
61 struct tmpfs_dirent *b);
62 RB_GENERATE(tmpfs_dirtree, tmpfs_dirent, rb_node, tmpfs_dirtree_compare);
63
64 static int tmpfs_dirtree_compare_cookie(struct tmpfs_dirent *a,
65 struct tmpfs_dirent *b);
66 RB_GENERATE(tmpfs_dirtree_cookie, tmpfs_dirent,
67 rb_cookienode, tmpfs_dirtree_compare_cookie);
68
69
70 /* --------------------------------------------------------------------- */
71
72 /*
73 * Allocates a new node of type 'type' inside the 'tmp' mount point, with
74 * its owner set to 'uid', its group to 'gid' and its mode set to 'mode',
75 * using the credentials of the process 'p'.
76 *
77 * If the node type is set to 'VDIR', then the parent parameter must point
78 * to the parent directory of the node being created. It may only be NULL
79 * while allocating the root node.
80 *
81 * If the node type is set to 'VBLK' or 'VCHR', then the rdev parameter
82 * specifies the device the node represents.
83 *
84 * If the node type is set to 'VLNK', then the parameter target specifies
85 * the file name of the target file for the symbolic link that is being
86 * created.
87 *
88 * Note that new nodes are retrieved from the available list if it has
89 * items or, if it is empty, from the node pool as long as there is enough
90 * space to create them.
91 *
92 * Returns zero on success or an appropriate error code on failure.
93 */
94 int
tmpfs_alloc_node(struct tmpfs_mount * tmp,enum vtype type,uid_t uid,gid_t gid,mode_t mode,char * target,int rmajor,int rminor,struct tmpfs_node ** node)95 tmpfs_alloc_node(struct tmpfs_mount *tmp, enum vtype type,
96 uid_t uid, gid_t gid, mode_t mode,
97 char *target, int rmajor, int rminor,
98 struct tmpfs_node **node)
99 {
100 struct tmpfs_node *nnode;
101 struct timespec ts;
102 dev_t rdev;
103
104 KKASSERT(IFF(type == VLNK, target != NULL));
105 KKASSERT(IFF(type == VBLK || type == VCHR, rmajor != VNOVAL));
106
107 if (tmp->tm_nodes_inuse >= tmp->tm_nodes_max)
108 return (ENOSPC);
109
110 nnode = kmalloc_obj(sizeof(struct tmpfs_node), tmp->tm_node_zone,
111 M_WAITOK | M_ZERO | M_NULLOK);
112 if (nnode == NULL)
113 return (ENOSPC);
114 tmpfs_node_init(nnode);
115
116 /* Generic initialization. */
117 nnode->tn_type = type;
118 vfs_timestamp(&ts);
119 nnode->tn_ctime = nnode->tn_mtime = nnode->tn_atime
120 = ts.tv_sec;
121 nnode->tn_ctimensec = nnode->tn_mtimensec = nnode->tn_atimensec
122 = ts.tv_nsec;
123 nnode->tn_uid = uid;
124 nnode->tn_gid = gid;
125 nnode->tn_mode = mode;
126 nnode->tn_id = tmpfs_fetch_ino(tmp);
127 nnode->tn_advlock.init_done = 0;
128 KKASSERT(nnode->tn_links == 0);
129
130 /* Type-specific initialization. */
131 switch (nnode->tn_type) {
132 case VBLK:
133 case VCHR:
134 rdev = makeudev(rmajor, rminor);
135 if (rdev == NOUDEV) {
136 tmpfs_node_uninit(nnode);
137 kfree_obj(nnode, tmp->tm_node_zone);
138 return(EINVAL);
139 }
140 nnode->tn_rdev = rdev;
141 break;
142
143 case VDIR:
144 RB_INIT(&nnode->tn_dir.tn_dirtree);
145 RB_INIT(&nnode->tn_dir.tn_cookietree);
146 nnode->tn_dir.tn_parent = NULL;
147 nnode->tn_size = 0;
148 break;
149
150 case VFIFO:
151 /* FALLTHROUGH */
152 case VSOCK:
153 break;
154
155 case VLNK:
156 nnode->tn_size = strlen(target);
157 nnode->tn_link = kmalloc(nnode->tn_size + 1, tmp->tm_name_zone,
158 M_WAITOK | M_NULLOK);
159 if (nnode->tn_link == NULL) {
160 tmpfs_node_uninit(nnode);
161 kfree_obj(nnode, tmp->tm_node_zone);
162 return (ENOSPC);
163 }
164 bcopy(target, nnode->tn_link, nnode->tn_size);
165 nnode->tn_link[nnode->tn_size] = '\0';
166 break;
167
168 case VREG:
169 nnode->tn_reg.tn_aobj = swap_pager_alloc(NULL, 0,
170 VM_PROT_DEFAULT, 0);
171 nnode->tn_reg.tn_aobj_pages = 0;
172 nnode->tn_size = 0;
173 vm_object_set_flag(nnode->tn_reg.tn_aobj, OBJ_NOPAGEIN);
174 break;
175
176 default:
177 panic("tmpfs_alloc_node: type %p %d", nnode, (int)nnode->tn_type);
178 }
179
180 TMPFS_NODE_LOCK(nnode);
181 TMPFS_LOCK(tmp);
182 LIST_INSERT_HEAD(&tmp->tm_nodes_used, nnode, tn_entries);
183 tmp->tm_nodes_inuse++;
184 TMPFS_UNLOCK(tmp);
185 TMPFS_NODE_UNLOCK(nnode);
186
187 *node = nnode;
188 return 0;
189 }
190
191 /* --------------------------------------------------------------------- */
192
193 /*
194 * Destroys the node pointed to by node from the file system 'tmp'.
195 * If the node does not belong to the given mount point, the results are
196 * unpredicted.
197 *
198 * If the node references a directory; no entries are allowed because
199 * their removal could need a recursive algorithm, something forbidden in
200 * kernel space. Furthermore, there is not need to provide such
201 * functionality (recursive removal) because the only primitives offered
202 * to the user are the removal of empty directories and the deletion of
203 * individual files.
204 *
205 * Note that nodes are not really deleted; in fact, when a node has been
206 * allocated, it cannot be deleted during the whole life of the file
207 * system. Instead, they are moved to the available list and remain there
208 * until reused.
209 *
210 * A caller must have TMPFS_NODE_LOCK(node) and this function unlocks it.
211 */
212 void
tmpfs_free_node(struct tmpfs_mount * tmp,struct tmpfs_node * node)213 tmpfs_free_node(struct tmpfs_mount *tmp, struct tmpfs_node *node)
214 {
215 vm_pindex_t pages = 0;
216
217 #ifdef INVARIANTS
218 TMPFS_ASSERT_ELOCKED(node);
219 KKASSERT(node->tn_vnode == NULL);
220 #endif
221 TMPFS_LOCK(tmp);
222 LIST_REMOVE(node, tn_entries);
223 tmp->tm_nodes_inuse--;
224 TMPFS_UNLOCK(tmp);
225 TMPFS_NODE_UNLOCK(node); /* Caller has this lock */
226
227 switch (node->tn_type) {
228 case VNON:
229 /* Do not do anything. VNON is provided to let the
230 * allocation routine clean itself easily by avoiding
231 * duplicating code in it. */
232 /* FALLTHROUGH */
233 case VBLK:
234 /* FALLTHROUGH */
235 case VCHR:
236 /* FALLTHROUGH */
237 break;
238 case VDIR:
239 /*
240 * The parent link can be NULL if this is the root
241 * node or if it is a directory node that was rmdir'd.
242 *
243 * XXX what if node is a directory which still contains
244 * directory entries (e.g. due to a forced umount) ?
245 */
246 node->tn_size = 0;
247 KKASSERT(node->tn_dir.tn_parent == NULL);
248
249 /*
250 * If the root node is being destroyed don't leave a
251 * dangling pointer in tmpfs_mount.
252 */
253 if (node == tmp->tm_root)
254 tmp->tm_root = NULL;
255 break;
256 case VFIFO:
257 /* FALLTHROUGH */
258 case VSOCK:
259 break;
260
261 case VLNK:
262 kfree(node->tn_link, tmp->tm_name_zone);
263 node->tn_link = NULL;
264 node->tn_size = 0;
265 break;
266
267 case VREG:
268 if (node->tn_reg.tn_aobj != NULL)
269 vm_object_deallocate(node->tn_reg.tn_aobj);
270 node->tn_reg.tn_aobj = NULL;
271 pages = node->tn_reg.tn_aobj_pages;
272 break;
273
274 default:
275 panic("tmpfs_free_node: type %p %d", node, (int)node->tn_type);
276 }
277
278 /*
279 * Clean up fields as a safety before destroying the entry.
280 */
281 tmpfs_node_uninit(node);
282 kfree_obj(node, tmp->tm_node_zone);
283 /* node is now invalid */
284
285 if (pages)
286 atomic_add_long(&tmp->tm_pages_used, -(long)pages);
287 }
288
289 /* --------------------------------------------------------------------- */
290
291 /*
292 * Allocates a new directory entry for the node node with a name of name.
293 * The new directory entry is returned in *de.
294 *
295 * The link count of node is increased by one to reflect the new object
296 * referencing it.
297 *
298 * Returns zero on success or an appropriate error code on failure.
299 */
300 int
tmpfs_alloc_dirent(struct tmpfs_mount * tmp,struct tmpfs_node * node,const char * name,uint16_t len,struct tmpfs_dirent ** de)301 tmpfs_alloc_dirent(struct tmpfs_mount *tmp, struct tmpfs_node *node,
302 const char *name, uint16_t len, struct tmpfs_dirent **de)
303 {
304 struct tmpfs_dirent *nde;
305
306 nde = kmalloc_obj(sizeof(struct tmpfs_dirent),
307 tmp->tm_dirent_zone, M_WAITOK);
308 nde->td_name = kmalloc(len + 1, tmp->tm_name_zone, M_WAITOK | M_NULLOK);
309 if (nde->td_name == NULL) {
310 kfree_obj(nde, tmp->tm_dirent_zone);
311 *de = NULL;
312 return (ENOSPC);
313 }
314 nde->td_namelen = len;
315 bcopy(name, nde->td_name, len);
316 nde->td_name[len] = '\0';
317
318 nde->td_node = node;
319
320 atomic_add_int(&node->tn_links, 1);
321
322 *de = nde;
323
324 return 0;
325 }
326
327 /* --------------------------------------------------------------------- */
328
329 /*
330 * Frees a directory entry. It is the caller's responsibility to destroy
331 * the node referenced by it if needed.
332 *
333 * The link count of node is decreased by one to reflect the removal of an
334 * object that referenced it. This only happens if 'node_exists' is true;
335 * otherwise the function will not access the node referred to by the
336 * directory entry, as it may already have been released from the outside.
337 */
338 void
tmpfs_free_dirent(struct tmpfs_mount * tmp,struct tmpfs_dirent * de)339 tmpfs_free_dirent(struct tmpfs_mount *tmp, struct tmpfs_dirent *de)
340 {
341 struct tmpfs_node *node;
342
343 node = de->td_node;
344
345 KKASSERT(node->tn_links > 0);
346 atomic_add_int(&node->tn_links, -1);
347
348 kfree(de->td_name, tmp->tm_name_zone);
349 de->td_namelen = 0;
350 de->td_name = NULL;
351 de->td_node = NULL;
352 kfree_obj(de, tmp->tm_dirent_zone);
353 }
354
355 /* --------------------------------------------------------------------- */
356
357 /*
358 * Allocates a new vnode for the node node or returns a new reference to
359 * an existing one if the node had already a vnode referencing it. The
360 * resulting locked vnode is returned in *vpp.
361 *
362 * Returns zero on success or an appropriate error code on failure.
363 *
364 * The caller must ensure that node cannot go away (usually by holding
365 * the related directory entry).
366 *
367 * If dnode is non-NULL this routine avoids deadlocking against it but
368 * can return EAGAIN. Caller must try again. The dnode lock will cycle
369 * in this case, it remains locked on return in all cases. dnode must
370 * be shared-locked.
371 */
372 int
tmpfs_alloc_vp(struct mount * mp,struct tmpfs_node * dnode,struct tmpfs_node * node,int lkflag,struct vnode ** vpp)373 tmpfs_alloc_vp(struct mount *mp,
374 struct tmpfs_node *dnode, struct tmpfs_node *node, int lkflag,
375 struct vnode **vpp)
376 {
377 int error = 0;
378 struct vnode *vp;
379
380 loop:
381 vp = NULL;
382 if (node->tn_vnode == NULL) {
383 error = getnewvnode(VT_TMPFS, mp, &vp,
384 VLKTIMEOUT, LK_CANRECURSE);
385 if (error)
386 goto out;
387 }
388
389 /*
390 * Interlocked extraction from node. This can race many things.
391 * We have to get a soft reference on the vnode while we hold
392 * the node locked, then acquire it properly and check for races.
393 */
394 TMPFS_NODE_LOCK(node);
395 if (node->tn_vnode) {
396 if (vp) {
397 vp->v_type = VBAD;
398 vx_put(vp);
399 }
400 vp = node->tn_vnode;
401
402 KKASSERT((node->tn_vpstate & TMPFS_VNODE_DOOMED) == 0);
403 vhold(vp);
404 TMPFS_NODE_UNLOCK(node);
405
406 if (dnode) {
407 /*
408 * Special-case handling to avoid deadlocking against
409 * dnode. This case has been validated and occurs
410 * every so often during synth builds and in other
411 * situations.
412 */
413 if (vget(vp, (lkflag & ~LK_RETRY) |
414 LK_NOWAIT |
415 LK_EXCLUSIVE) != 0)
416 {
417 TMPFS_NODE_UNLOCK(dnode);
418 if (vget(vp, (lkflag & ~LK_RETRY) |
419 LK_SLEEPFAIL |
420 LK_EXCLUSIVE) == 0) {
421 vput(vp);
422 }
423 vdrop(vp);
424 TMPFS_NODE_LOCK_SH(dnode);
425
426 return EAGAIN;
427 }
428 } else {
429 /*
430 * Normal path
431 */
432 if (vget(vp, lkflag | LK_EXCLUSIVE) != 0) {
433 vdrop(vp);
434 goto loop;
435 }
436 }
437 if (node->tn_vnode != vp) {
438 vput(vp);
439 vdrop(vp);
440 goto loop;
441 }
442 vdrop(vp);
443 goto out;
444 }
445
446 /*
447 * We need to assign node->tn_vnode. If vp is NULL, loop up to
448 * allocate the vp. This can happen due to SMP races.
449 */
450 if (vp == NULL) {
451 TMPFS_NODE_UNLOCK(node);
452 goto loop;
453 }
454
455 /*
456 * This should never happen.
457 */
458 if (node->tn_vpstate & TMPFS_VNODE_DOOMED) {
459 TMPFS_NODE_UNLOCK(node);
460 vp->v_type = VBAD;
461 vx_put(vp);
462 error = ENOENT;
463 goto out;
464 }
465
466 KKASSERT(node->tn_vnode == NULL);
467 KKASSERT(vp != NULL);
468 vp->v_data = node;
469 vp->v_type = node->tn_type;
470
471 /* Type-specific initialization. */
472 switch (node->tn_type) {
473 case VBLK:
474 /* FALLTHROUGH */
475 case VCHR:
476 /* FALLTHROUGH */
477 case VSOCK:
478 break;
479 case VREG:
480 /*
481 * VMIO is mandatory. Tmpfs also supports KVABIO
482 * for its tmpfs_strategy().
483 */
484 vsetflags(vp, VKVABIO);
485 vinitvmio(vp, node->tn_size, node->tn_blksize, -1);
486 break;
487 case VLNK:
488 break;
489 case VFIFO:
490 vp->v_ops = &mp->mnt_vn_fifo_ops;
491 break;
492 case VDIR:
493 break;
494
495 default:
496 panic("tmpfs_alloc_vp: type %p %d", node, (int)node->tn_type);
497 }
498
499 node->tn_vnode = vp;
500 TMPFS_NODE_UNLOCK(node);
501
502 vx_downgrade(vp);
503 out:
504 *vpp = vp;
505 KKASSERT(IFF(error == 0, *vpp != NULL && vn_islocked(*vpp)));
506
507 return error;
508 }
509
510 /* --------------------------------------------------------------------- */
511
512 /*
513 * Allocates a new file of type 'type' and adds it to the parent directory
514 * 'dvp'; this addition is done using the component name given in 'cnp'.
515 * The ownership of the new file is automatically assigned based on the
516 * credentials of the caller (through 'cnp'), the group is set based on
517 * the parent directory and the mode is determined from the 'vap' argument.
518 * If successful, *vpp holds a vnode to the newly created file and zero
519 * is returned. Otherwise *vpp is NULL and the function returns an
520 * appropriate error code.
521 */
522 int
tmpfs_alloc_file(struct vnode * dvp,struct vnode ** vpp,struct vattr * vap,struct namecache * ncp,struct ucred * cred,char * target)523 tmpfs_alloc_file(struct vnode *dvp, struct vnode **vpp, struct vattr *vap,
524 struct namecache *ncp, struct ucred *cred, char *target)
525 {
526 int error;
527 struct tmpfs_dirent *de;
528 struct tmpfs_mount *tmp;
529 struct tmpfs_node *dnode;
530 struct tmpfs_node *node;
531
532 tmp = VFS_TO_TMPFS(dvp->v_mount);
533 dnode = VP_TO_TMPFS_DIR(dvp);
534 *vpp = NULL;
535
536 TMPFS_NODE_LOCK(dnode);
537
538 /*
539 * If the directory was removed but a process was CD'd into it,
540 * we do not allow any more file/dir creation within it. Otherwise
541 * we will lose track of it.
542 */
543 KKASSERT(dnode->tn_type == VDIR);
544 if (dnode != tmp->tm_root && dnode->tn_dir.tn_parent == NULL) {
545 TMPFS_NODE_UNLOCK(dnode);
546 return ENOENT;
547 }
548
549 /*
550 * Make sure the link count does not overflow.
551 */
552 if (vap->va_type == VDIR && dnode->tn_links >= LINK_MAX) {
553 TMPFS_NODE_UNLOCK(dnode);
554 return EMLINK;
555 }
556
557 /* Allocate a node that represents the new file. */
558 error = tmpfs_alloc_node(tmp, vap->va_type, cred->cr_uid,
559 dnode->tn_gid, vap->va_mode, target,
560 vap->va_rmajor, vap->va_rminor, &node);
561 if (error != 0) {
562 TMPFS_NODE_UNLOCK(dnode);
563 return error;
564 }
565 TMPFS_NODE_LOCK(node);
566
567 /* Allocate a directory entry that points to the new file. */
568 error = tmpfs_alloc_dirent(tmp, node, ncp->nc_name, ncp->nc_nlen, &de);
569 if (error != 0) {
570 TMPFS_NODE_UNLOCK(dnode);
571 tmpfs_free_node(tmp, node);
572 /* eats node lock */
573 return error;
574 }
575
576 /* Allocate a vnode for the new file. */
577 error = tmpfs_alloc_vp(dvp->v_mount, NULL, node, LK_EXCLUSIVE, vpp);
578 if (error != 0) {
579 TMPFS_NODE_UNLOCK(dnode);
580 tmpfs_free_dirent(tmp, de);
581 tmpfs_free_node(tmp, node);
582 /* eats node lock */
583 return error;
584 }
585
586 /*
587 * Now that all required items are allocated, we can proceed to
588 * insert the new node into the directory, an operation that
589 * cannot fail.
590 */
591 tmpfs_dir_attach_locked(dnode, de);
592 TMPFS_NODE_UNLOCK(dnode);
593 TMPFS_NODE_UNLOCK(node);
594
595 return error;
596 }
597
598 /* --------------------------------------------------------------------- */
599
600 /*
601 * Attaches the directory entry de to the directory represented by dnode.
602 * Note that this does not change the link count of the node pointed by
603 * the directory entry, as this is done by tmpfs_alloc_dirent.
604 *
605 * dnode must be locked.
606 */
607 void
tmpfs_dir_attach_locked(struct tmpfs_node * dnode,struct tmpfs_dirent * de)608 tmpfs_dir_attach_locked(struct tmpfs_node *dnode, struct tmpfs_dirent *de)
609 {
610 struct tmpfs_node *node = de->td_node;
611 struct tmpfs_dirent *de2;
612
613 if (node && node->tn_type == VDIR) {
614 TMPFS_NODE_LOCK(node);
615 atomic_add_int(&node->tn_links, 1);
616 node->tn_status |= TMPFS_NODE_CHANGED;
617 node->tn_dir.tn_parent = dnode;
618 atomic_add_int(&dnode->tn_links, 1);
619 TMPFS_NODE_UNLOCK(node);
620 }
621 de2 = RB_INSERT(tmpfs_dirtree, &dnode->tn_dir.tn_dirtree, de);
622 KASSERT(de2 == NULL,
623 ("tmpfs_dir_attach_lockedA: duplicate insertion of %p, has %p\n",
624 de, de2));
625 de2 = RB_INSERT(tmpfs_dirtree_cookie, &dnode->tn_dir.tn_cookietree, de);
626 KASSERT(de2 == NULL,
627 ("tmpfs_dir_attach_lockedB: duplicate insertion of %p, has %p\n",
628 de, de2));
629 dnode->tn_size += sizeof(struct tmpfs_dirent);
630 dnode->tn_status |= TMPFS_NODE_ACCESSED | TMPFS_NODE_CHANGED |
631 TMPFS_NODE_MODIFIED;
632 }
633
634 /* --------------------------------------------------------------------- */
635
636 /*
637 * Detaches the directory entry de from the directory represented by dnode.
638 * Note that this does not change the link count of the node pointed by
639 * the directory entry, as this is done by tmpfs_free_dirent.
640 *
641 * dnode must be locked.
642 */
643 void
tmpfs_dir_detach_locked(struct tmpfs_node * dnode,struct tmpfs_dirent * de)644 tmpfs_dir_detach_locked(struct tmpfs_node *dnode, struct tmpfs_dirent *de)
645 {
646 struct tmpfs_node *node = de->td_node;
647
648 RB_REMOVE(tmpfs_dirtree, &dnode->tn_dir.tn_dirtree, de);
649 RB_REMOVE(tmpfs_dirtree_cookie, &dnode->tn_dir.tn_cookietree, de);
650 dnode->tn_size -= sizeof(struct tmpfs_dirent);
651 dnode->tn_status |= TMPFS_NODE_ACCESSED | TMPFS_NODE_CHANGED |
652 TMPFS_NODE_MODIFIED;
653
654 /*
655 * Clean out the tn_parent pointer immediately when removing a
656 * directory.
657 *
658 * Removal of the parent linkage also cleans out the extra tn_links
659 * count we had on both node and dnode.
660 *
661 * node can be NULL (typ during a forced umount), in which case
662 * the mount code is dealing with the linkages from a linked list
663 * scan.
664 */
665 if (node && node->tn_type == VDIR && node->tn_dir.tn_parent) {
666 TMPFS_NODE_LOCK(node);
667 KKASSERT(node->tn_dir.tn_parent == dnode);
668 atomic_add_int(&dnode->tn_links, -1);
669 atomic_add_int(&node->tn_links, -1);
670 node->tn_dir.tn_parent = NULL;
671 TMPFS_NODE_UNLOCK(node);
672 }
673 }
674
675 /* --------------------------------------------------------------------- */
676
677 /*
678 * Looks for a directory entry in the directory represented by node.
679 * 'ncp' describes the name of the entry to look for. Note that the .
680 * and .. components are not allowed as they do not physically exist
681 * within directories.
682 *
683 * Returns a pointer to the entry when found, otherwise NULL.
684 *
685 * Caller must hold the node locked (shared ok)
686 */
687 struct tmpfs_dirent *
tmpfs_dir_lookup(struct tmpfs_node * node,struct tmpfs_node * f,struct namecache * ncp)688 tmpfs_dir_lookup(struct tmpfs_node *node, struct tmpfs_node *f,
689 struct namecache *ncp)
690 {
691 struct tmpfs_dirent *de;
692 int len = ncp->nc_nlen;
693 struct tmpfs_dirent wanted;
694
695 wanted.td_namelen = len;
696 wanted.td_name = ncp->nc_name;
697
698 TMPFS_VALIDATE_DIR(node);
699
700 de = RB_FIND(tmpfs_dirtree, &node->tn_dir.tn_dirtree, &wanted);
701
702 KASSERT((f == NULL || de == NULL || f == de->td_node),
703 ("tmpfs_dir_lookup: Incorrect node %p %p %p",
704 f, de, (de ? de->td_node : NULL)));
705
706 return de;
707 }
708
709 /* --------------------------------------------------------------------- */
710
711 /*
712 * Helper function for tmpfs_readdir. Creates a '.' entry for the given
713 * directory and returns it in the uio space. The function returns 0
714 * on success, -1 if there was not enough space in the uio structure to
715 * hold the directory entry or an appropriate error code if another
716 * error happens.
717 */
718 int
tmpfs_dir_getdotdent(struct tmpfs_node * node,struct uio * uio)719 tmpfs_dir_getdotdent(struct tmpfs_node *node, struct uio *uio)
720 {
721 int error;
722
723 TMPFS_VALIDATE_DIR(node);
724 KKASSERT(uio->uio_offset == TMPFS_DIRCOOKIE_DOT);
725
726 if (vop_write_dirent(&error, uio, node->tn_id, DT_DIR, 1, "."))
727 return -1;
728 if (error == 0)
729 uio->uio_offset = TMPFS_DIRCOOKIE_DOTDOT;
730 return error;
731 }
732
733 /* --------------------------------------------------------------------- */
734
735 /*
736 * Helper function for tmpfs_readdir. Creates a '..' entry for the given
737 * directory and returns it in the uio space. The function returns 0
738 * on success, -1 if there was not enough space in the uio structure to
739 * hold the directory entry or an appropriate error code if another
740 * error happens.
741 */
742 int
tmpfs_dir_getdotdotdent(struct tmpfs_mount * tmp,struct tmpfs_node * node,struct uio * uio)743 tmpfs_dir_getdotdotdent(struct tmpfs_mount *tmp, struct tmpfs_node *node,
744 struct uio *uio)
745 {
746 int error;
747 ino_t d_ino;
748
749 TMPFS_VALIDATE_DIR(node);
750 KKASSERT(uio->uio_offset == TMPFS_DIRCOOKIE_DOTDOT);
751
752 if (node->tn_dir.tn_parent) {
753 TMPFS_NODE_LOCK(node);
754 if (node->tn_dir.tn_parent)
755 d_ino = node->tn_dir.tn_parent->tn_id;
756 else
757 d_ino = tmp->tm_root->tn_id;
758 TMPFS_NODE_UNLOCK(node);
759 } else {
760 d_ino = tmp->tm_root->tn_id;
761 }
762
763 if (vop_write_dirent(&error, uio, d_ino, DT_DIR, 2, ".."))
764 return -1;
765 if (error == 0) {
766 struct tmpfs_dirent *de;
767 de = RB_MIN(tmpfs_dirtree_cookie, &node->tn_dir.tn_cookietree);
768 if (de == NULL)
769 uio->uio_offset = TMPFS_DIRCOOKIE_EOF;
770 else
771 uio->uio_offset = tmpfs_dircookie(de);
772 }
773 return error;
774 }
775
776 /* --------------------------------------------------------------------- */
777
778 /*
779 * Lookup a directory entry by its associated cookie.
780 *
781 * Must be called with the directory node locked (shared ok)
782 */
783 #if 0
784
785 struct lubycookie_info {
786 off_t cookie;
787 struct tmpfs_dirent *de;
788 };
789
790 static int
791 lubycookie_cmp(struct tmpfs_dirent *de, void *arg)
792 {
793 struct lubycookie_info *info = arg;
794 off_t cookie = tmpfs_dircookie(de);
795
796 if (cookie < info->cookie)
797 return(-1);
798 if (cookie > info->cookie)
799 return(1);
800 return(0);
801 }
802
803 static int
804 lubycookie_callback(struct tmpfs_dirent *de, void *arg)
805 {
806 struct lubycookie_info *info = arg;
807
808 if (tmpfs_dircookie(de) == info->cookie) {
809 info->de = de;
810 return(-1);
811 }
812 return(0);
813 }
814
815 #endif
816
817 /*
818 * Find first cookie >= (cookie). If exact specified, find the exact
819 * cookie.
820 */
821 struct tmpfs_dirent *
tmpfs_dir_lookupbycookie(struct tmpfs_node * node,off_t cookie,int exact)822 tmpfs_dir_lookupbycookie(struct tmpfs_node *node, off_t cookie, int exact)
823 {
824 #if 0
825 struct lubycookie_info info;
826
827 info.cookie = cookie;
828 info.de = NULL;
829 RB_SCAN(tmpfs_dirtree_cookie, &node->tn_dir.tn_cookietree,
830 lubycookie_cmp, lubycookie_callback, &info);
831 return (info.de);
832 #endif
833 struct tmpfs_dirent *cdent = tmpfs_cookiedir(cookie);
834 struct tmpfs_dirent *last;
835 struct tmpfs_dirent *tmp;
836
837 last = NULL;
838 tmp = RB_ROOT(&node->tn_dir.tn_cookietree);
839 while (tmp) {
840 if (cdent == tmp)
841 return cdent;
842 if (cdent > tmp) {
843 last = tmp;
844 tmp = RB_RIGHT(tmp, rb_cookienode);
845 } else {
846 tmp = RB_LEFT(tmp, rb_cookienode);
847 }
848 }
849 return (exact ? NULL : last);
850 }
851
852 /* --------------------------------------------------------------------- */
853
854 /*
855 * Helper function for tmpfs_readdir. Returns as much directory entries
856 * as can fit in the uio space. The read starts at uio->uio_offset.
857 * The function returns 0 on success, -1 if there was not enough space
858 * in the uio structure to hold the directory entry or an appropriate
859 * error code if another error happens.
860 *
861 * Caller must hold the node locked (shared ok)
862 */
863 int
tmpfs_dir_getdents(struct tmpfs_node * node,struct uio * uio,off_t * cntp)864 tmpfs_dir_getdents(struct tmpfs_node *node, struct uio *uio, off_t *cntp)
865 {
866 int error;
867 off_t startcookie;
868 struct tmpfs_dirent *de;
869
870 TMPFS_VALIDATE_DIR(node);
871
872 /*
873 * Locate the first directory entry we have to return. We have cached
874 * the last readdir in the node, so use those values if appropriate.
875 * Otherwise do a linear scan to find the requested entry.
876 *
877 * If a particular cookie does not exist, locate the first valid
878 * cookie after that one.
879 */
880 startcookie = uio->uio_offset;
881 KKASSERT(startcookie != TMPFS_DIRCOOKIE_DOT);
882 KKASSERT(startcookie != TMPFS_DIRCOOKIE_DOTDOT);
883
884 if (startcookie == TMPFS_DIRCOOKIE_EOF)
885 return 0;
886
887 /*
888 * Inexact lookup, find first direntry with a cookie >= startcookie.
889 * If none found we are at the EOF.
890 */
891 de = tmpfs_dir_lookupbycookie(node, startcookie, 0);
892 if (de == NULL) {
893 uio->uio_offset = TMPFS_DIRCOOKIE_EOF;
894 return 0;
895 }
896
897 /*
898 * Read as much entries as possible; i.e., until we reach the end of
899 * the directory or we exhaust uio space.
900 */
901 do {
902 ino_t d_ino;
903 uint8_t d_type;
904
905 /* Create a dirent structure representing the current
906 * tmpfs_node and fill it. */
907 d_ino = de->td_node->tn_id;
908 switch (de->td_node->tn_type) {
909 case VBLK:
910 d_type = DT_BLK;
911 break;
912
913 case VCHR:
914 d_type = DT_CHR;
915 break;
916
917 case VDIR:
918 d_type = DT_DIR;
919 break;
920
921 case VFIFO:
922 d_type = DT_FIFO;
923 break;
924
925 case VLNK:
926 d_type = DT_LNK;
927 break;
928
929 case VREG:
930 d_type = DT_REG;
931 break;
932
933 case VSOCK:
934 d_type = DT_SOCK;
935 break;
936
937 default:
938 panic("tmpfs_dir_getdents: type %p %d",
939 de->td_node, (int)de->td_node->tn_type);
940 }
941 KKASSERT(de->td_namelen < 256); /* 255 + 1 */
942
943 if (vop_write_dirent(&error, uio, d_ino, d_type,
944 de->td_namelen, de->td_name)) {
945 error = -1;
946 break;
947 }
948
949 (*cntp)++;
950 de = RB_NEXT(tmpfs_dirtree_cookie,
951 node->tn_dir.tn_cookietree, de);
952 } while (error == 0 && uio->uio_resid > 0 && de != NULL);
953
954 /* Update the offset and cache. */
955 if (de == NULL) {
956 uio->uio_offset = TMPFS_DIRCOOKIE_EOF;
957 } else {
958 uio->uio_offset = tmpfs_dircookie(de);
959 }
960
961 return error;
962 }
963
964 /* --------------------------------------------------------------------- */
965
966 /*
967 * Resizes the aobj associated to the regular file pointed to by vp to
968 * the size newsize. 'vp' must point to a vnode that represents a regular
969 * file. 'newsize' must be positive.
970 *
971 * pass NVEXTF_TRIVIAL when buf content will be overwritten, otherwise set 0
972 * to be zero filled.
973 *
974 * Returns zero on success or an appropriate error code on failure.
975 *
976 * Caller must hold the node exclusively locked.
977 */
978 int
tmpfs_reg_resize(struct vnode * vp,off_t newsize,int trivial)979 tmpfs_reg_resize(struct vnode *vp, off_t newsize, int trivial)
980 {
981 int error;
982 vm_pindex_t newpages, oldpages;
983 struct tmpfs_mount *tmp;
984 struct tmpfs_node *node;
985 off_t oldsize;
986 int nvextflags;
987
988 #ifdef INVARIANTS
989 KKASSERT(vp->v_type == VREG);
990 KKASSERT(newsize >= 0);
991 #endif
992
993 node = VP_TO_TMPFS_NODE(vp);
994 tmp = VFS_TO_TMPFS(vp->v_mount);
995
996 /*
997 * Convert the old and new sizes to the number of pages needed to
998 * store them. It may happen that we do not need to do anything
999 * because the last allocated page can accommodate the change on
1000 * its own.
1001 */
1002 oldsize = node->tn_size;
1003 oldpages = round_page64(oldsize) / PAGE_SIZE;
1004 KKASSERT(oldpages == node->tn_reg.tn_aobj_pages);
1005 newpages = round_page64(newsize) / PAGE_SIZE;
1006
1007 if (newpages > oldpages &&
1008 tmp->tm_pages_used + newpages - oldpages > tmp->tm_pages_max) {
1009 error = ENOSPC;
1010 goto out;
1011 }
1012 node->tn_reg.tn_aobj_pages = newpages;
1013 node->tn_size = newsize;
1014
1015 if (newpages != oldpages)
1016 atomic_add_long(&tmp->tm_pages_used, (newpages - oldpages));
1017
1018 /*
1019 * nvextflags to pass along for bdwrite() vs buwrite(), this is
1020 * so tmpfs activity doesn't eat memory being freed by the pageout
1021 * daemon.
1022 */
1023 if (vm_pages_needed || vm_paging_start(0) ||
1024 tmpfs_bufcache_mode >= 2) {
1025 nvextflags = 0;
1026 } else {
1027 nvextflags = NVEXTF_BUWRITE;
1028 }
1029
1030
1031 /*
1032 * When adjusting the vnode filesize and its VM object we must
1033 * also adjust our backing VM object (aobj). The blocksize
1034 * used must match the block sized we use for the buffer cache.
1035 *
1036 * The backing VM object may contain VM pages as well as swap
1037 * assignments if we previously renamed main object pages into
1038 * it during deactivation.
1039 *
1040 * To make things easier tmpfs uses a blksize in multiples of
1041 * PAGE_SIZE, and will only increase the blksize as a small file
1042 * increases in size. Once a file has exceeded TMPFS_BLKSIZE (16KB),
1043 * the blksize is maxed out. Truncating the file does not reduce
1044 * the blksize.
1045 */
1046 if (newsize < oldsize) {
1047 vm_pindex_t osize;
1048 vm_pindex_t nsize;
1049 vm_object_t aobj;
1050
1051 error = nvtruncbuf(vp, newsize, node->tn_blksize,
1052 -1, nvextflags);
1053 aobj = node->tn_reg.tn_aobj;
1054 if (aobj) {
1055 osize = aobj->size;
1056 nsize = vp->v_object->size;
1057 if (nsize < osize) {
1058 aobj->size = osize;
1059 swap_pager_freespace(aobj, nsize,
1060 osize - nsize);
1061 vm_object_page_remove(aobj, nsize, osize,
1062 FALSE);
1063 }
1064 }
1065 } else {
1066 vm_object_t aobj;
1067 int nblksize;
1068
1069 /*
1070 * The first (and only the first) buffer in the file is resized
1071 * in multiples of PAGE_SIZE, up to TMPFS_BLKSIZE.
1072 */
1073 nblksize = node->tn_blksize;
1074 while (nblksize < TMPFS_BLKSIZE &&
1075 nblksize < newsize) {
1076 nblksize += PAGE_SIZE;
1077 }
1078
1079 if (trivial)
1080 nvextflags |= NVEXTF_TRIVIAL;
1081
1082 error = nvextendbuf(vp, oldsize, newsize,
1083 node->tn_blksize, nblksize,
1084 -1, -1, nvextflags);
1085 node->tn_blksize = nblksize;
1086 aobj = node->tn_reg.tn_aobj;
1087 if (aobj)
1088 aobj->size = vp->v_object->size;
1089 }
1090
1091 out:
1092 return error;
1093 }
1094
1095 /* --------------------------------------------------------------------- */
1096
1097 /*
1098 * Change flags of the given vnode.
1099 * Caller should execute tmpfs_update on vp after a successful execution.
1100 * The vnode must be locked on entry and remain locked on exit.
1101 */
1102 int
tmpfs_chflags(struct vnode * vp,u_long vaflags,struct ucred * cred)1103 tmpfs_chflags(struct vnode *vp, u_long vaflags, struct ucred *cred)
1104 {
1105 int error;
1106 struct tmpfs_node *node;
1107 int flags;
1108
1109 KKASSERT(vn_islocked(vp));
1110
1111 node = VP_TO_TMPFS_NODE(vp);
1112 flags = node->tn_flags;
1113
1114 /* Disallow this operation if the file system is mounted read-only. */
1115 if (vp->v_mount->mnt_flag & MNT_RDONLY)
1116 return EROFS;
1117 error = vop_helper_setattr_flags(&flags, vaflags, node->tn_uid, cred);
1118
1119 /* Actually change the flags on the node itself */
1120 if (error == 0) {
1121 TMPFS_NODE_LOCK(node);
1122 node->tn_flags = flags;
1123 node->tn_status |= TMPFS_NODE_CHANGED;
1124 TMPFS_NODE_UNLOCK(node);
1125 }
1126
1127 KKASSERT(vn_islocked(vp));
1128
1129 return error;
1130 }
1131
1132 /* --------------------------------------------------------------------- */
1133
1134 /*
1135 * Change access mode on the given vnode.
1136 * Caller should execute tmpfs_update on vp after a successful execution.
1137 * The vnode must be locked on entry and remain locked on exit.
1138 */
1139 int
tmpfs_chmod(struct vnode * vp,mode_t vamode,struct ucred * cred)1140 tmpfs_chmod(struct vnode *vp, mode_t vamode, struct ucred *cred)
1141 {
1142 struct tmpfs_node *node;
1143 mode_t cur_mode;
1144 int error;
1145
1146 KKASSERT(vn_islocked(vp));
1147
1148 node = VP_TO_TMPFS_NODE(vp);
1149
1150 /* Disallow this operation if the file system is mounted read-only. */
1151 if (vp->v_mount->mnt_flag & MNT_RDONLY)
1152 return EROFS;
1153
1154 /* Immutable or append-only files cannot be modified, either. */
1155 if (node->tn_flags & (IMMUTABLE | APPEND))
1156 return EPERM;
1157
1158 cur_mode = node->tn_mode;
1159 error = vop_helper_chmod(vp, vamode, cred, node->tn_uid, node->tn_gid,
1160 &cur_mode);
1161
1162 if (error == 0 &&
1163 (node->tn_mode & ALLPERMS) != (cur_mode & ALLPERMS)) {
1164 TMPFS_NODE_LOCK(node);
1165 node->tn_mode &= ~ALLPERMS;
1166 node->tn_mode |= cur_mode & ALLPERMS;
1167
1168 node->tn_status |= TMPFS_NODE_CHANGED;
1169 TMPFS_NODE_UNLOCK(node);
1170 }
1171
1172 KKASSERT(vn_islocked(vp));
1173
1174 return 0;
1175 }
1176
1177 /* --------------------------------------------------------------------- */
1178
1179 /*
1180 * Change ownership of the given vnode. At least one of uid or gid must
1181 * be different than VNOVAL. If one is set to that value, the attribute
1182 * is unchanged.
1183 * Caller should execute tmpfs_update on vp after a successful execution.
1184 * The vnode must be locked on entry and remain locked on exit.
1185 */
1186 int
tmpfs_chown(struct vnode * vp,uid_t uid,gid_t gid,struct ucred * cred)1187 tmpfs_chown(struct vnode *vp, uid_t uid, gid_t gid, struct ucred *cred)
1188 {
1189 mode_t cur_mode;
1190 uid_t cur_uid;
1191 gid_t cur_gid;
1192 struct tmpfs_node *node;
1193 int error;
1194
1195 KKASSERT(vn_islocked(vp));
1196 node = VP_TO_TMPFS_NODE(vp);
1197
1198 /* Disallow this operation if the file system is mounted read-only. */
1199 if (vp->v_mount->mnt_flag & MNT_RDONLY)
1200 return EROFS;
1201
1202 /* Immutable or append-only files cannot be modified, either. */
1203 if (node->tn_flags & (IMMUTABLE | APPEND))
1204 return EPERM;
1205
1206 cur_uid = node->tn_uid;
1207 cur_gid = node->tn_gid;
1208 cur_mode = node->tn_mode;
1209 error = vop_helper_chown(vp, uid, gid, cred,
1210 &cur_uid, &cur_gid, &cur_mode);
1211
1212 if (error == 0) {
1213 TMPFS_NODE_LOCK(node);
1214 if (cur_uid != node->tn_uid ||
1215 cur_gid != node->tn_gid ||
1216 cur_mode != node->tn_mode) {
1217 node->tn_uid = cur_uid;
1218 node->tn_gid = cur_gid;
1219 node->tn_mode = cur_mode;
1220 node->tn_status |= TMPFS_NODE_CHANGED;
1221 }
1222 TMPFS_NODE_UNLOCK(node);
1223 }
1224
1225 return error;
1226 }
1227
1228 /* --------------------------------------------------------------------- */
1229
1230 /*
1231 * Change size of the given vnode.
1232 * Caller should execute tmpfs_update on vp after a successful execution.
1233 * The vnode must be locked on entry and remain locked on exit.
1234 */
1235 int
tmpfs_chsize(struct vnode * vp,u_quad_t size,struct ucred * cred)1236 tmpfs_chsize(struct vnode *vp, u_quad_t size, struct ucred *cred)
1237 {
1238 int error;
1239 struct tmpfs_node *node;
1240
1241 KKASSERT(vn_islocked(vp));
1242
1243 node = VP_TO_TMPFS_NODE(vp);
1244
1245 /* Decide whether this is a valid operation based on the file type. */
1246 error = 0;
1247 switch (vp->v_type) {
1248 case VDIR:
1249 return EISDIR;
1250
1251 case VREG:
1252 if (vp->v_mount->mnt_flag & MNT_RDONLY)
1253 return EROFS;
1254 break;
1255
1256 case VBLK:
1257 /* FALLTHROUGH */
1258 case VCHR:
1259 /* FALLTHROUGH */
1260 case VFIFO:
1261 /* Allow modifications of special files even if in the file
1262 * system is mounted read-only (we are not modifying the
1263 * files themselves, but the objects they represent). */
1264 return 0;
1265
1266 default:
1267 /* Anything else is unsupported. */
1268 return EOPNOTSUPP;
1269 }
1270
1271 /* Immutable or append-only files cannot be modified, either. */
1272 if (node->tn_flags & (IMMUTABLE | APPEND))
1273 return EPERM;
1274
1275 error = tmpfs_truncate(vp, size);
1276 /* tmpfs_truncate will raise the NOTE_EXTEND and NOTE_ATTRIB kevents
1277 * for us, as will update tn_status; no need to do that here. */
1278
1279 KKASSERT(vn_islocked(vp));
1280
1281 return error;
1282 }
1283
1284 /* --------------------------------------------------------------------- */
1285
1286 /*
1287 * Change access and modification times of the given vnode.
1288 * Caller should execute tmpfs_update on vp after a successful execution.
1289 * The vnode must be locked on entry and remain locked on exit.
1290 */
1291 int
tmpfs_chtimes(struct vnode * vp,struct timespec * atime,struct timespec * mtime,int vaflags,struct ucred * cred)1292 tmpfs_chtimes(struct vnode *vp, struct timespec *atime, struct timespec *mtime,
1293 int vaflags, struct ucred *cred)
1294 {
1295 struct tmpfs_node *node;
1296
1297 KKASSERT(vn_islocked(vp));
1298
1299 node = VP_TO_TMPFS_NODE(vp);
1300
1301 /* Disallow this operation if the file system is mounted read-only. */
1302 if (vp->v_mount->mnt_flag & MNT_RDONLY)
1303 return EROFS;
1304
1305 /* Immutable or append-only files cannot be modified, either. */
1306 if (node->tn_flags & (IMMUTABLE | APPEND))
1307 return EPERM;
1308
1309 TMPFS_NODE_LOCK(node);
1310 if (atime->tv_sec != VNOVAL && atime->tv_nsec != VNOVAL)
1311 node->tn_status |= TMPFS_NODE_ACCESSED;
1312
1313 if (mtime->tv_sec != VNOVAL && mtime->tv_nsec != VNOVAL) {
1314 node->tn_status |= TMPFS_NODE_MODIFIED;
1315 vclrflags(vp, VLASTWRITETS);
1316 }
1317
1318 TMPFS_NODE_UNLOCK(node);
1319
1320 tmpfs_itimes(vp, atime, mtime);
1321
1322 KKASSERT(vn_islocked(vp));
1323
1324 return 0;
1325 }
1326
1327 /* --------------------------------------------------------------------- */
1328 /* Sync timestamps */
1329 void
tmpfs_itimes(struct vnode * vp,const struct timespec * acc,const struct timespec * mod)1330 tmpfs_itimes(struct vnode *vp, const struct timespec *acc,
1331 const struct timespec *mod)
1332 {
1333 struct tmpfs_node *node;
1334 struct timespec now;
1335
1336 node = VP_TO_TMPFS_NODE(vp);
1337
1338 if ((node->tn_status & (TMPFS_NODE_ACCESSED | TMPFS_NODE_MODIFIED |
1339 TMPFS_NODE_CHANGED)) == 0) {
1340 return;
1341 }
1342
1343 vfs_timestamp(&now);
1344
1345 TMPFS_NODE_LOCK(node);
1346 if (node->tn_status & TMPFS_NODE_ACCESSED) {
1347 if (acc == NULL)
1348 acc = &now;
1349 node->tn_atime = acc->tv_sec;
1350 node->tn_atimensec = acc->tv_nsec;
1351 }
1352 if (node->tn_status & TMPFS_NODE_MODIFIED) {
1353 if (mod == NULL)
1354 mod = &now;
1355 node->tn_mtime = mod->tv_sec;
1356 node->tn_mtimensec = mod->tv_nsec;
1357 }
1358 if (node->tn_status & TMPFS_NODE_CHANGED) {
1359 node->tn_ctime = now.tv_sec;
1360 node->tn_ctimensec = now.tv_nsec;
1361 }
1362
1363 node->tn_status &= ~(TMPFS_NODE_ACCESSED |
1364 TMPFS_NODE_MODIFIED |
1365 TMPFS_NODE_CHANGED);
1366 TMPFS_NODE_UNLOCK(node);
1367 }
1368
1369 /* --------------------------------------------------------------------- */
1370
1371 void
tmpfs_update(struct vnode * vp)1372 tmpfs_update(struct vnode *vp)
1373 {
1374 tmpfs_itimes(vp, NULL, NULL);
1375 }
1376
1377 /* --------------------------------------------------------------------- */
1378
1379 /*
1380 * Caller must hold an exclusive node lock.
1381 */
1382 int
tmpfs_truncate(struct vnode * vp,off_t length)1383 tmpfs_truncate(struct vnode *vp, off_t length)
1384 {
1385 int error;
1386 struct tmpfs_node *node;
1387
1388 node = VP_TO_TMPFS_NODE(vp);
1389
1390 if (length < 0) {
1391 error = EINVAL;
1392 goto out;
1393 }
1394
1395 if (node->tn_size == length) {
1396 error = 0;
1397 goto out;
1398 }
1399
1400 if (length > VFS_TO_TMPFS(vp->v_mount)->tm_maxfilesize)
1401 return (EFBIG);
1402
1403
1404 error = tmpfs_reg_resize(vp, length, 1);
1405
1406 if (error == 0)
1407 node->tn_status |= TMPFS_NODE_CHANGED | TMPFS_NODE_MODIFIED;
1408
1409 out:
1410 tmpfs_update(vp);
1411
1412 return error;
1413 }
1414
1415 /* --------------------------------------------------------------------- */
1416
1417 static ino_t
tmpfs_fetch_ino(struct tmpfs_mount * tmp)1418 tmpfs_fetch_ino(struct tmpfs_mount *tmp)
1419 {
1420 ino_t ret;
1421
1422 ret = atomic_fetchadd_64(&tmp->tm_ino, 1);
1423
1424 return (ret);
1425 }
1426
1427 static int
tmpfs_dirtree_compare(struct tmpfs_dirent * a,struct tmpfs_dirent * b)1428 tmpfs_dirtree_compare(struct tmpfs_dirent *a, struct tmpfs_dirent *b)
1429 {
1430 if (a->td_namelen > b->td_namelen)
1431 return 1;
1432 else if (a->td_namelen < b->td_namelen)
1433 return -1;
1434 else
1435 return strncmp(a->td_name, b->td_name, a->td_namelen);
1436 }
1437
1438 static int
tmpfs_dirtree_compare_cookie(struct tmpfs_dirent * a,struct tmpfs_dirent * b)1439 tmpfs_dirtree_compare_cookie(struct tmpfs_dirent *a, struct tmpfs_dirent *b)
1440 {
1441 if (a < b)
1442 return(-1);
1443 if (a > b)
1444 return(1);
1445 return 0;
1446 }
1447
1448 /*
1449 * Lock for rename. The namecache entries for the related terminal files
1450 * are already locked but the directories are not. A directory lock order
1451 * reversal is possible so use a deterministic order.
1452 *
1453 * Generally order path parent-to-child or using a simple pointer comparison.
1454 * Probably not perfect but it should catch most of the cases.
1455 *
1456 * Underlying files must be locked after the related directory.
1457 */
1458 void
tmpfs_lock4(struct tmpfs_node * node1,struct tmpfs_node * node2,struct tmpfs_node * node3,struct tmpfs_node * node4)1459 tmpfs_lock4(struct tmpfs_node *node1, struct tmpfs_node *node2,
1460 struct tmpfs_node *node3, struct tmpfs_node *node4)
1461 {
1462 if (node1->tn_dir.tn_parent != node2 &&
1463 (node1 < node2 || node2->tn_dir.tn_parent == node1)) {
1464 TMPFS_NODE_LOCK(node1); /* fdir */
1465 TMPFS_NODE_LOCK(node3); /* ffile */
1466 TMPFS_NODE_LOCK(node2); /* tdir */
1467 if (node4)
1468 TMPFS_NODE_LOCK(node4); /* tfile */
1469 } else {
1470 TMPFS_NODE_LOCK(node2); /* tdir */
1471 if (node4)
1472 TMPFS_NODE_LOCK(node4); /* tfile */
1473 TMPFS_NODE_LOCK(node1); /* fdir */
1474 TMPFS_NODE_LOCK(node3); /* ffile */
1475 }
1476 }
1477
1478 void
tmpfs_unlock4(struct tmpfs_node * node1,struct tmpfs_node * node2,struct tmpfs_node * node3,struct tmpfs_node * node4)1479 tmpfs_unlock4(struct tmpfs_node *node1, struct tmpfs_node *node2,
1480 struct tmpfs_node *node3, struct tmpfs_node *node4)
1481 {
1482 if (node4)
1483 TMPFS_NODE_UNLOCK(node4);
1484 TMPFS_NODE_UNLOCK(node2);
1485 TMPFS_NODE_UNLOCK(node3);
1486 TMPFS_NODE_UNLOCK(node1);
1487 }
1488